Calcium metabolism and cardiovascular function after spaceflight

NASA Technical Reports Server (NTRS)

Hatton, Daniel C.; Yue, Qi; Dierickx, Jacqueline; Roullet, Chantal; Otsuka, Keiichi; Watanabe, Mitsuaki; Coste, Sarah; Roullet, Jean Baptiste; Phanouvang, Thongchan; Orwoll, Eric;

Association of salivary calcium, phosphate, pH and flow rate on oral health: A study on 90 subjects.

PubMed

Fiyaz, Mohamed; Ramesh, Amitha; Ramalingam, Karthikeyan; Thomas, Biju; Shetty, Sucheta; Prakash, Prashanth

2013-07-01

This study was designed to compare inorganic salivary calcium, phosphate, flow rate and pH of un-stimulated saliva and oral hygiene of healthy subjects, patients with periodontitis and dental caries and to correlate salivary calcium level with the number of intact teeth. The present study consisted of 90 patients aged between 18 and 55 years and were divided into three groups, periodontitis, dental caries and controls. Oral hygiene index-simplified, probing pocket depth, clinical attachment level and number of teeth present, teeth with active carious lesions were recorded. Salivary flow rate and pH was recorded and subjected to biochemical investigation. Estimation of inorganic calcium and phosphate was performed by colorimetric method. Results showed statistically significant increase in salivary inorganic calcium and phosphate levels, poor oral hygiene status, pH and salivary flow rate in patients with periodontitis when compared with dental caries group and controls. Individuals who have increased salivary inorganic calcium, phosphate, pH, flow rate and maintain poor oral hygiene could be at a higher risk for developing periodontitis and may have less dental caries and more number of intact teeth.

Association of salivary calcium, phosphate, pH and flow rate on oral health: A study on 90 subjects

PubMed Central

Fiyaz, Mohamed; Ramesh, Amitha; Ramalingam, Karthikeyan; Thomas, Biju; Shetty, Sucheta; Prakash, Prashanth

2013-01-01

Background and Objectives: This study was designed to compare inorganic salivary calcium, phosphate, flow rate and pH of un-stimulated saliva and oral hygiene of healthy subjects, patients with periodontitis and dental caries and to correlate salivary calcium level with the number of intact teeth. Materials and Methods: The present study consisted of 90 patients aged between 18 and 55 years and were divided into three groups, periodontitis, dental caries and controls. Oral hygiene index-simplified, probing pocket depth, clinical attachment level and number of teeth present, teeth with active carious lesions were recorded. Salivary flow rate and pH was recorded and subjected to biochemical investigation. Estimation of inorganic calcium and phosphate was performed by colorimetric method. Results: Results showed statistically significant increase in salivary inorganic calcium and phosphate levels, poor oral hygiene status, pH and salivary flow rate in patients with periodontitis when compared with dental caries group and controls. Interpretation and Conclusion: Individuals who have increased salivary inorganic calcium, phosphate, pH, flow rate and maintain poor oral hygiene could be at a higher risk for developing periodontitis and may have less dental caries and more number of intact teeth. PMID:24174724

A study of water hardness and the prevalence of hypomagnesaemia and hypocalcaemia in healthy subjects of Surat district (Gujarat).

PubMed

Kanadhia, Kirti C; Ramavataram, Divvi Venkata Subrahmanya Shri; Nilakhe, Shreeyas Prasad Dhanpal; Patel, Swati

2014-01-01

Various sources of drinking water, with varying levels of total hardness, and calcium and magnesium concentrations, are used by populations in different regions. The use of water purifiers can compound the problem of maintaining the desired levels of hardness. An inverse relationship between various conditions, including cardiovascular disease, and hard water has been reported. Until this study, investigation of the hardness of drinking water from different sources, and serum magnesium and calcium in normal subjects from the Surat district, had not been undertaken. This study was performed to assess the concentrations of calcium and magnesium, and total hardness in filtered and non-filtered water and the relationship with serum magnesium and calcium levels in normal subjects consuming such water. Three water samples were collected, at 15-day intervals, from 12 urban and rural areas of Surat; and also 10 different brands of bottled water. Samples were analyzed for total hardness and calcium by complexometric and EDTA methods respectively. Magnesium concentrations were obtained by subtraction of the calcium concentration from total hardness. Serum samples from healthy individuals were analyzed for magnesium and calcium using calmagite and arsenazo methods respectively. The independent t-test was used to establish significance at a level of 95%. A p-value <0.05 was considered significant. Mean total hardness, and calcium and magnesium concentrations in non-filtered, rural tube-well water were much higher than in filtered water from the same area, and the magnesium concentrations were significantly higher (p = 0.038). Filtered urban municipal had lower hardness and concentrations of calcium and magnesium (p = 0.01) compared to corresponding non-filtered water. Significantly lower levels were observed in bottled water compared to rural and urban sources of water. Serum magnesium was significantly lower in the population who were consuming filtered water compared to those drinking non-filtered water (p<0.05). No such difference was observed for serum calcium. Hypomagnesemia correlates with lower magnesium concentrations in drinking water (both rural tube-well and urban municipal waters), which can be attributed to the use of water purifiers. Assuming that a person consumes two liters of drinking water per day, it is estimated that there is an average loss of 160 mg (79%) of magnesium from total waterborne magnesium levels as a result of the filtration of both rural and urban water supplies. Bottled water is too hardness as in calcium and magnesium concentrations.

CalQuo: automated, simultaneous single-cell and population-level quantification of global intracellular Ca2+ responses.

PubMed

Fritzsche, Marco; Fernandes, Ricardo A; Colin-York, Huw; Santos, Ana M; Lee, Steven F; Lagerholm, B Christoffer; Davis, Simon J; Eggeling, Christian

2015-11-13

Detecting intracellular calcium signaling with fluorescent calcium indicator dyes is often coupled with microscopy techniques to follow the activation state of non-excitable cells, including lymphocytes. However, the analysis of global intracellular calcium responses both at the single-cell level and in large ensembles simultaneously has yet to be automated. Here, we present a new software package, CalQuo (Calcium Quantification), which allows the automated analysis and simultaneous monitoring of global fluorescent calcium reporter-based signaling responses in up to 1000 single cells per experiment, at temporal resolutions of sub-seconds to seconds. CalQuo quantifies the number and fraction of responding cells, the temporal dependence of calcium signaling and provides global and individual calcium-reporter fluorescence intensity profiles. We demonstrate the utility of the new method by comparing the calcium-based signaling responses of genetically manipulated human lymphocytic cell lines.

Preventive effects of the aqueous extract of Cichorium intybus L. flower on ethylene glycol-induced renal calculi in rats

PubMed Central

Emamiyan, Mahdieh Zaman; Vaezi, Gholamhassan; Tehranipour, Maryam; Shahrohkabadi, Khdije; Shiravi, Abdolhossein

2018-01-01

Objective: Urolithiasis remains a global problem. Despite the availability of numerous methods, no definite therapeutic agent has been yet introduced for the prevention or treatment of kidney stones. In this study, we evaluated the possible preventive effects of aqueous extract of Cichorium intybus L. (chicory) flowers on ethylene glycol-induced renal calculi in rats. Materials and Methods: A total of 24 Wistar rats were randomly divided into four groups and were treated for 30 days. Group A received drinking tap water, while groups B, C, and D were administered with 1% ethylene glycol for induction of calcium oxalate stone formation. Rats in groups C and D received intraperitoneal injections of the aqueous extract of chicory flowers (50 and 200 mg/kg, respectively) since the first day of the experiment. The urine volume, urine pH, and urinary levels of oxalate, citrate, calcium, uric acid, and creatinine as well as serum levels of calcium, uric acid, and creatinine were measured. After 30 days, the rats' kidneys were removed and prepared for histological evaluation of calcium oxalate deposits. One-way analysis of variance (ANOVA), followed by Tukey's test, was performed, using SPSS version 20. Results: The number of calcium oxalate crystals was significantly higher in group B (ethylene glycol-only treated animals), compared to group A (control), group C (50 mg/kg of aqueous extract), and group D (200 mg/kg of aqueous extract) (p<0.05). On day 30, the urine level of citrate, oxalate (p>0.05), and creatinine (p<0.05), as well as urine pH (p<0.05) decreased in groups C and D, compared to group B. Also, urine calcium level, urine uric acid (p>0.05), and urine volume (p<0.05) were higher in group D, compared to group B. In addition, the serum level of calcium, creatinine (p<0.05), and uric acid (p<0.001) decreased in groups C and D. Conclusion: The aqueous extract of chicory flower (50 mg/kg) could reduce the number of calcium oxalate deposits in the urine and reduce the level of serum parameters. PMID:29632848

Evaluation of calcium ion, hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments: An in vitro study

PubMed Central

Fulzele, Punit; Baliga, Sudhindra; Thosar, Nilima; Pradhan, Debaprya

2011-01-01

Aims: Evaluation of calcium ion and hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments. Objective: The purpose of this study was to evaluate calcium and hydroxyl ion release and pH levels of calcium hydroxide based products, namely, RC Cal, Metapex, calcium hydroxide with distilled water, along with the new gutta-percha points with calcium hydroxide. Materials and Methods: The materials were inserted in polyethylene tubes and immersed in deionized water. The pH variation, Ca++ and OH- release were monitored periodically for 1 week. Statistical Analysis Used: Statistical analysis was carried out using one-way analysis of variance and Tukey's post hoc tests with PASW Statistics version 18 software to compare the statistical difference. Results: After 1 week, calcium hydroxide with distilled water and RC Cal raised the pH to 12.7 and 11.8, respectively, while a small change was observed for Metapex, calcium hydroxide gutta-percha points. The calcium released after 1 week was 15.36 mg/dL from RC Cal, followed by 13.04, 1.296, 3.064 mg/dL from calcium hydroxide with sterile water, Metapex and calcium hydroxide gutta-percha points, respectively. Conclusions: Calcium hydroxide with sterile water and RC Cal pastes liberate significantly more calcium and hydroxyl ions and raise the pH higher than Metapex and calcium hydroxidegutta-percha points. PMID:22346155

Calcium and vitamin D supplementation and risk of kidney stone formation in postmenopausal women.

PubMed

Haghighi, Anousheh; Samimagham, Hamidreza; Gohardehi, Golnar

2013-05-21

Calcium and vitamin D are essential structural components of the skeletal system, which prevent osteoporosis after menopause. However, there is a controversial debate on the association between the intake of calcium and vitamin D supplements and the increased risk of formation of kidney calculi in postmenopausal women. which yet have to be confirmed. This study aimed to compare the metabolic changes after supplementation of calcium and vitamin D and examine the risk of stone formation. Fifty-three postmenopausal women referred to rheumatology clinic who had no history of kidney calculi, bone diseases (apart from osteoporosis), metabolic, and rheumatic disorders and had not been receiving calcium, diuretics and calcitonin were investigated. Renal ultrasonography and blood tests were performed and the urine calcium levels were measured for a period of 24 hours for all patients. The examinations were repeated after a 1- year period of treatment with supplemental calcium (100 mg/d) and vitamin D (400 IU/d) and compared with the data before the treatment. After 1 year, asymptomatic lithiasis was confirmed in 1 of 53 patients (1.9%) using ultrasonographic examination. No significant differences were found between the 24-hour urine and blood calcium levels before and after the treatment. Our findings showed that oral intake of calcium and vitamin D after 1 year has no effect on the urinary calcium excretion rate and the formation of kidney calculi in postmenopausal women.

Altering the level of calcium changes the physical properties and digestibility of casein-based emulsion gels.

PubMed

McIntyre, Irene; O Sullivan, Michael; O Riordan, Dolores

2017-04-19

Casein-based emulsion gels prepared with different types of lipid (i.e. milk fat or rapeseed oil) were formulated with high (774 mg Ca per 100 g) or low (357 mg Ca per 100 g) calcium levels by blending acid and rennet casein. Their physicochemical characteristics (i.e. composition, texture, microstructure & water mobility) and in vitro digestibility were compared to conventionally formulated high-calcium (723 mg Ca per 100 g) emulsion gels made from rennet casein with calcium chelating salts (CCS). CCS-free, high-calcium emulsion gels were significantly (p ≤ 0.05) softer than those with low calcium levels (possibly due to their shorter manufacture time and higher pH) and showed the highest rates of disintegration during simulated gastric digestion. Despite having a higher moisture to protein ratio, the high-calcium emulsion gels containing CCS had broadly similar hardness values to those of high-calcium concentration prepared without CCS, but had higher cohesiveness. The high-calcium matrices containing CCS had quite a different microstructure and increased water mobility compared to those made without CCS and showed the slowest rate (p ≤ 0.05) of disintegration in the gastric environment. Gastric resistance was not affected by the type of lipid phase. Conversely, fatty acid release was similar for all emulsion gels prepared from milk fat, however, high-calcium emulsion gels (CCS-free) prepared from rapeseed oil showed higher lipolysis. Results suggest that food matrix physical properties can be modified to alter resistance to gastric degradation which may have consequences for the kinetics of nutrient release and delivery of bioactives sensitive to the gastric environment.

A randomized controlled clinical trial investigating the effect of calcium supplement plus low-dose aspirin on hs-CRP, oxidative stress and insulin resistance in pregnant women at risk for pre-eclampsia.

PubMed

Asemi, Z; Samimi, M; Heidarzadeh, Z; Khorrammian, H; Tabassi, Z

2012-05-15

Increased levels of pro-inflammatory factors, markers of oxidative stress and insulin resistance during pregnancy have been associated with the development of pre-eclampsia. There is some evidence to suggest that calcium supplement and aspirin can reduce the risk of the disorder. To our knowledge, no reports are available indicating the effects of consumed calcium supplement plus aspirin on high sensitivity C-reactive protein (hs-CRP), oxidative stress parameters and insulin resistance in pregnant women at risk for pre-eclampsia. This study was designed to investigate the effects of consumed calcium supplement plus low-dose aspirin on hs-CRP, oxidative stress parameters and insulin resistance among Iranian pregnant women at risk for pre-eclampsia. This randomized single-blind controlled clinical trial was carried out among 42 pregnant women at risk for pre-eclampsia, primigravida, aged 18-40 year old who were carrying singleton pregnancy at their third trimester. Subjects were randomly assigned to received either the placebo (n = 22) or calcium supplement plus low-dose aspirin (n = 20) for 9 weeks. Calcium supplement plus low-dose aspirin were containing 500 mg carbonate calcium plus 80 mg aspirin. Fasting blood samples were taken at baseline and after 9 weeks intervention to measure serum hs-CRP, oxidative stress parameters including plasma Total Antioxidant Capacity (TAC) and Total Glutathione (GSH), Fasting Plasma Glucose (FPG), serum insulin and HOMA-IR score. Consumption of calcium supplement plus low-dose aspirin resulted in a significant difference serum hs-CRP levels as compared to the placebo (102.87 vs. 3227.75 ng mL(-1), p = 0.01). Also, mean changes for plasma TAC (68.96 vs. -74.46 mmol L(-1), p = 0.04) and total GSH levels (304.33 vs. -39.33 micromol L(-1), p = 0.03) were significantly different between the two groups. No significant differences were found comparing calcium supplement plus low-dose aspirin and placebo in terms of their effects on FPG, serum insulin levels and HOMA-IR. Within-group differences in the placebo group revealed a significant increase in serum hs-CRP levels (3227.75 ng mL(-1), p = 0.008) and marginally significant increase in plasma total GSH levels (304.33 micromol L(-1), p = 0.07). In conclusion, consumption calcium supplement plus low-dose aspirin during pregnancy for 9 weeks in pregnant women at risk for pre-eclampsia resulted in a significant difference serum hs-CRP and increased levels of plasma TAC and total GSH as compared to the placebo group, but could not affect serum insulin levels and HOMA-IR score.

Calcium absorption from fortified ice cream formulations compared with calcium absorption from milk.

PubMed

van der Hee, Regine M; Miret, Silvia; Slettenaar, Marieke; Duchateau, Guus S M J E; Rietveld, Anton G; Wilkinson, Joy E; Quail, Patricia J; Berry, Mark J; Dainty, Jack R; Teucher, Birgit; Fairweather-Tait, Susan J

2009-05-01

Optimal bone mass in early adulthood is achieved through appropriate diet and lifestyle, thereby protecting against osteoporosis and risk of bone fracture in later life. Calcium and vitamin D are essential to build adequate bones, but calcium intakes of many population groups do not meet dietary reference values. In addition, changes in dietary patterns are exacerbating the problem, thereby emphasizing the important role of calcium-rich food products. We have designed a calcium-fortified ice cream formulation that is lower in fat than regular ice cream and could provide a useful source of additional dietary calcium. Calcium absorption from two different ice cream formulations was determined in young adults and compared with milk. Sixteen healthy volunteers (25 to 45 years of age), recruited from the general public of The Netherlands, participated in a randomized, reference-controlled, double-blind cross-over study in which two test products and milk were consumed with a light standard breakfast on three separate occasions: a standard portion of ice cream (60 g) fortified with milk minerals and containing a low level (3%) of butter fat, ice cream (60 g) fortified with milk minerals and containing a typical level (9%) of coconut oil, and reduced-fat milk (1.7% milk fat) (200 mL). Calcium absorption was measured by the dual-label stable isotope technique. Effects on calcium absorption were evaluated by analysis of variance. Fractional absorption of calcium from the 3% butterfat ice cream, 9% coconut oil ice cream, and milk was 26%+/-8%, 28%+/-5%, and 31%+/-9%, respectively, and did not differ significantly (P=0.159). Results indicate that calcium bioavailability in the two calcium-fortified ice cream formulations used in this study is as high as milk, indicating that ice cream may be a good vehicle for delivery of calcium.

Study of stone composition changes in melamine-related urinary calculi and its clinical significance.

PubMed

Li, Yuan; Chen, YiRong; Zhang, Wei; Huang, XiaoGang; Li, WenHui; Ru, XiaoRui; Meng, Min; Xi, Xinsheng; Huang, Gang; Shi, BaoGuang; Liu, Gang; Li, WeiHua; Xu, Hui

2011-08-01

To investigate the composition changes in melamine-related urinary calculi and their clinical significance. A total of 49 melamine-related urinary calculi were included from 49 children (age 4-82 months, mean 22). The qualitative analysis of stone composition was determined using Fourier transform infrared. The quantitative analysis of the stone computed tomography (CT) attenuation value, stone uric acid level, and stone calcium level were measured using spiral CT, high-performance liquid chromatography, and flame atomic absorption spectrum, respectively. Fourier transform infrared showed that 41 (84%) of the 49 stones contained uric acid and 25 (51%) contained calcium compounds. The data from the qualitative and quantitative analysis were available for 15 stones because of sample consumption in the detection process (Fourier transform infrared, atomic absorption spectrum, and high-performance liquid chromatography). A negative correlation was observed between stone uric acid level and stone calcium level (n = 15, r = -0.629, P = .009). A positive correlation was observed between the stone calcium level and stone CT attenuation value (n = 25, r = 0.855, P = .000). Compared with the ≤1-year-age group and the 1-2-year-age group, the stone calcium level in the >2-year-age group was significantly greater (27.51% ± 12.65% vs 1.60% ± 1.68% or 10.12% ± 8.69%, P = .000 and P = .003, respectively). Compared with the alkalization-alone group, the stone calcium level in the nonalkalization-alone group was significant greater (19.83% ± 7.48% vs 1.25% ± 1.43%, n = 19, P = .000). The stones from children >2 years old were not amenable to medical treatment because they contained greater levels of calcium, which can be demonstrated by the radiologic "positive stone image" or stone CT attenuation value. We believe that surgical invention will be the best choice for such patients if extracorporeal shock wave lithotripsy has failed. Copyright © 2011 Elsevier Inc. All rights reserved.

Organic Selenium Alleviated the Formation of Ethylene Glycol-Induced Calcium Oxalate Renal Calculi by Improving Osteopontin Expression and Antioxidant Capability in Dogs.

PubMed

Liu, Yongwang; Xu, Haibin; Zhong, Wenting; Shen, Qingpeng; Zhuang, Tenghan; Huang, Kehe

2015-12-01

Twenty one-year-old local male dogs were randomly assigned into four groups (five dogs per group). The control and the ethylene glycol (EG) groups were fed basal diets without and with EG, and the EG+sodium selenite (EG+SS) and EG+selenium yeast (EG+SY) groups were fed basal diets with EG containing SS and SY, respectively. Blood, urine, and renal samples were taken after 18 weeks of feeding. The results showed that compared with the control group, the serum calcium levels and antioxidase activities significantly decreased in the EG group. Serum creatinine, urea nitrogen, and malondialdehyde (MDA) levels and urine calcium and oxalate levels significantly increased. Calcium oxalate crystal deposition and osteopontin (OPN) messenger RNA and protein expression in the renal tissues significantly increased. These changes above in the EG group were reversed within limits by adding selenium in the diets (both EG+SS and EG+SY groups). Further, compared with the EG+SS group, the EG+SY group showed better effects in decreasing the formation of EG-induced calcium oxalate renal calculi and OPN expression and improving antioxidant capability in dogs. It indicates that organic selenium has the potential value to alleviate the formation of EG-induced calcium oxalate renal calculi.

Regulation of the reserve carbohydrate metabolism by alkaline pH and calcium in Neurospora crassa reveals a possible cross-regulation of both signaling pathways.

PubMed

Virgilio, Stela; Cupertino, Fernanda Barbosa; Ambrosio, Daniela Luz; Bertolini, Maria Célia

2017-06-09

Glycogen and trehalose are storage carbohydrates and their levels in microorganisms vary according to environmental conditions. In Neurospora crassa, alkaline pH stress highly influences glycogen levels, and in Saccharomyces cerevisiae, the response to pH stress also involves the calcineurin signaling pathway mediated by the Crz1 transcription factor. Recently, in yeast, pH stress response genes were identified as targets of Crz1 including genes involved in glycogen and trehalose metabolism. In this work, we present evidence that in N. crassa the glycogen and trehalose metabolism is modulated by alkaline pH and calcium stresses. We demonstrated that the pH signaling pathway in N. crassa controls the accumulation of the reserve carbohydrates glycogen and trehalose via the PAC-3 transcription factor, which is the central regulator of the signaling pathway. The protein binds to the promoters of most of the genes encoding enzymes of glycogen and trehalose metabolism and regulates their expression. We also demonstrated that the reserve carbohydrate levels and gene expression are both modulated under calcium stress and that the response to calcium stress may involve the concerted action of PAC-3. Calcium activates growth of the Δpac-3 strain and influences its glycogen and trehalose accumulation. In addition, calcium stress differently regulates glycogen and trehalose metabolism in the mutant strain compared to the wild-type strain. While glycogen levels are decreased in both strains, the trehalose levels are significantly increased in the wild-type strain and not affected by calcium in the mutant strain when compared to mycelium not exposed to calcium. We previously reported the role of PAC-3 as a transcription factor involved in glycogen metabolism regulation by controlling the expression of the gsn gene, which encodes an enzyme of glycogen synthesis. In this work, we extended the investigation by studying in greater detail the effects of pH on the metabolism of the reserve carbohydrate glycogen and trehalose. We also demonstrated that calcium stress affects the reserve carbohydrate levels and the response to calcium stress may require PAC-3. Considering that the reserve carbohydrate metabolism may be subjected to different signaling pathways control, our data contribute to the understanding of the N. crassa responses under pH and calcium stresses.

A randomised study to compare salivary pH, calcium, phosphate and calculus formation after using anticavity dentifrices containing Recaldent(®) and functionalized tri-calcium phosphate.

PubMed

Sharma, Ena; Vishwanathamurthy, Ramesh Alampalli; Nadella, Manjari; Savitha, A N; Gundannavar, Gayatri; Hussain, M Ahad

2012-10-01

The aim of this study was to estimate the pH of saliva, concentration of calcium and inorganic phosphate, and calculus formation before and after usage of Recaldent(®) (GC Tooth Mousse Plus™), Functionalized Tricalcium Phosphate (3M ESPE ClinPro™ Tooth Crème) and standard dentifrice (Colgate dental cream). Randomized double-blind study. A total of 50 subjects were recruited, the subjects were assessed at their first visit, on the 21(st) day and on the 42(nd) day. At the first visit, scaling was carried out and oral hygiene instructions were given. After 21 days, the subjects were given coded dentifrices where the operator and the subjects both were unaware of the type of dentifrice. Clinical parameters assessed were Plaque index, Gingival index, and Calculus index. Salivary samples were obtained to measure calcium, phosphate levels, and pH at 21(st) day and 42(nd) day. ANOVA test, t-test, Mann-Whitney test, Kruskal-Wallis test. The mean salivary calcium level and mean salivary phosphate level were higher in Group III (functionalized tricalcium phosphate (3M ESPE ClinPro™ Tooth Creme) as compared to Group II (Recaldent(®) GC Tooth Mousse Plus™) and Group I (Colgate dental cream) on the 42(nd) day after using dentifrices, which was statistically significant. This showed that the usage of remineralizing dentifrices led to an increase in the salivary calcium, phosphate, and pH but it did not reach the level of super saturation of the ions caused by elevated pH which could lead to calculus formation. Thought here was a statistically significant increase in salivary calcium and phosphate level in all three groups from baseline to 42(nd) day, there was no calculus formation.

Evaluation of Serum Calcium as a Predictor of Biochemical Recurrence following Salvage Radiation Therapy for Prostate Cancer

PubMed Central

Peterson, Jennifer L.; Buskirk, Steven J.; Heckman, Michael G.; Parker, Alexander S.; Diehl, Nancy N.; Tzou, Katherine S.; Paryani, Nitesh N.; Ko, Stephen J.; Daugherty, Larry C.; Vallow, Laura A.; Pisansky, Thomas M.

2013-01-01

Background. Previous reports have shown a positive association between serum calcium level and prostate cancer mortality. However, there is no data regarding whether higher serum calcium levels are associated with increased risk of biochemical recurrence (BCR) following salvage radiation therapy (SRT) for prostate cancer. Herein, we evaluate the association between pretreatment serum calcium levels and BCR in a cohort of men who underwent SRT. Methods. We evaluated 165 patients who underwent SRT at our institution. Median dose was 65.0 Gy (range: 54.0–72.4 Gy). We considered serum calcium as both a continuous variable and a 3-level categorical variable (low [≤9.0 mg/dL], moderate [>9.0 mg/dL and ≤9.35 mg/dL], and high [>9.35 mg/dL]) based on sample tertiles. Results. We observed no evidence of a linear association between serum calcium and BCR (relative risk (RR): 0.96, P = 0.76). Compared to men with low calcium, there was no significantly increased risk of BCR for men with moderate (RR: 0.94, P = 0.79) or high (RR: 1.08, P = 0.76) serum calcium levels. Adjustment for clinical, pathological, and SRT characteristics in multivariable analyses did not alter these findings. Conclusion. Our results provide evidence that pretreatment serum calcium is unlikely to be a useful tool in predicting BCR risk following SRT. PMID:23606986

Assessment the levels of tartrate-resistant acid phosphatase (TRAP) on mice fed with eggshell calcium citrate malate.

PubMed

Yu, Yiding; Zhang, Mingdi; Lin, Songyi; Wang, Liyan; Liu, Jingbo; Jones, Gregory; Huang, Hsiang-Chi

2013-07-01

Optimized conditions were obtained by one-factor-at-a-time test (OFAT) and ternary quadratic regression orthogonal composite design (TQROCD) respectively. By pulse electric fields (PEF) technology, the process of eggshell calcium citrate malate (ESCCM), eggshell calcium citrate (ESCC) and eggshells calcium malate (ESCM) were comprehensive compared. The levels of tartrate-resistant acid phosphatase (TRAP) and the bioavailability on mice fed with eggshell calcium citrate malate (ESCCM) treated by pulsed electric field (PEF) were evaluated. Results showed that the rates of calcium dissolution of the different acids studied can be arranged as ESCCM (7.90 mg/mL)>ESCC (7.12 mg/mL)>ESCM (7.08 mg/mL) from highest to lowest rate of dissolution. At the same dose 133.0 mg kg(-1) d(-1), the levels of TRAP in the ESCCM treatment groups were significantly lower than those in ESCM and ESCC (P<0.05). Bone calcium content in the mice fed with ESCCM was generally higher than fed with ESCM and ESCC. Copyright © 2013 Elsevier B.V. All rights reserved.

Use of fly ash in diets of cage and floor broilers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pharr, C.L.; Andrews, L.D.

1980-09-01

Three experiments were conducted to compare limestone to fly ash from a coal-fired generator station as a calcium source for broilers. In experiment 1, 5 male and 5 female broiler chicks were placed in each of 32 cages. Sixteen cages of birds were fed a ration with limestone supplying 30% of the total calcium and 16 cages were fed a ration with 30% of the total calcium supplied by fly ash. The total calcium and phosphorus levels of the rations were 1.0% and .5%, respectively. In this experiment no significant difference was found for 8-week body weight between diets wheremore » the added calcium was from limestone or fly ash. In experiment 2 a group of 40 male and 40 female cage reared broilers and 40 male and 40 female floor reared broilers were fed a basal diet of limestone providing 33% of the total calcium. Three diets with increasing fly ash levels were fed to three cage groups of 40 male and 40 female broilers providing 33, 46, and 45% of the total calcium of .9, 1.1, and 1.8%, respectively. Broilers fed the highest fly ash level weighed significantly less at 8 weeks than the caged controls but did not differ from the other treatments. Bone breaking strength as measured by the Allo Kramer Shear Press was similar between the basal and low level fly ash group and increased with higher fly ash levels. In experiment 3 four groups of 40 male broilers in cages were fed limestone diets with graded levels of limestone for the calcium source. Another four groups of 40 caged male broilers were fed fly ash diets with equivalent graded levels of fly ash for the calcium source. Both limestone and fly ash diets provided .17, .34, .51, and .68% calcium of a total calcium content of .28, .45, .62, and .79%, respectively.« less

Elevated 1,25-dihydroxyvitamin D levels in patients with chronic obstructive pulmonary disease treated with prednisone

NASA Technical Reports Server (NTRS)

Bikle, D. D.; Halloran, B.; Fong, L.; Steinbach, L.; Shellito, J.

1993-01-01

Glucocorticoid administration is a well established cause of osteopenia. Mechanisms underlying the deleterious effect of glucocorticoids on bone may include direct inhibition of bone formation as well as indirect effects through changes in intestinal calcium absorption, renal calcium excretion, and/or levels of the calciotropic hormones. To further examine the potential role of the calciotropic hormones we measured serum levels of PTH and 1,25 dihydroxyvitamin D [1,25(OH)2D], as well as serum and urine levels of calcium and vertebral bone density in patients with chronic obstructive pulmonary disease being managed with or without prednisone. Patients treated with prednisone had lower spinal bone density (53 vs. 106 mg/cm3) and higher serum calcium (2.40 vs. 2.33 mmol/l), urine calcium (6.9 vs. 2.7 mmol/24h), and 1,25(OH)2D levels (147 vs. 95 pmol/L). Compared to the patients not treated with glucocorticoids. PTH levels also tended to be higher (33 vs. 26 microliters-eq/ml), but the difference was not significant. Serum and urine calcium levels correlated positively with 1,25(OH)2D levels, but none of these measurements correlated with PTH levels. Our results suggest that prednisone treatment alters the regulation of 1,25(OH)2D production, and this may contribute to the loss of bone mineral induced by prednisone.

Evidence of charge exchange pumping in calcium-xenon system

NASA Technical Reports Server (NTRS)

Chubb, D. L.

1973-01-01

Charge exchange between xenon ions and calcium atoms may produce an inversion between the 5s or 4d and 4p energy levels of the calcium ions. A low power flowing xenon plasma seeded with calcium was utilized to determine if charge exchange or electron collisions populate the 5s and 4d levels Ca(+). Line intensity ratios proportional to the density ratios n5s/n4p and n4d/n4p were measured. From the dependence of these intensity ratios on power input to the xenon plasma it was concluded that charge exchange pumping of the 5s and 4d levels predominates over electron collisional pumping of these levels. Also, by comparing intensity ratios obtained using argon and krypton in place of xenon with those obtained in xenon the same conclusion was made.

Effects of calcium and vitamin D supplementation on blood pressure and serum lipids and carotenoids: a randomized, double-blind, placebo-controlled, clinical trial.

PubMed

Chai, Weiwen; Cooney, Robert V; Franke, Adrian A; Bostick, Roberd M

2013-09-01

To estimate the effects of calcium or vitamin D supplementation or a combination of both on blood pressure and serum lipid and carotenoid levels. Ninety-two colorectal adenoma patients were randomized in a pilot, double-blind, placebo-controlled clinical trial of supplemental vitamin D3 800 IU and elemental calcium 2.0 g (as calcium carbonate) alone or in combination in divided doses twice daily with meals over 6 months. Relative to placebo, mean serum triglycerides decreased 30% (P = .10) and 32% (P = .10) in the calcium and calcium plus vitamin D3 treatment groups, respectively. When the two calcium intervention groups were pooled and compared with the pooled noncalcium groups, the estimated supplemental calcium treatment effects were statistically significant for triglycerides (P = .04). Similar but nonstatistically significant decreases (5%-7%) were observed for serum total cholesterol levels. Mean systolic blood pressure increased 6% (P = .08) in the calcium group; otherwise, there were no appreciable changes in systolic or diastolic blood pressures in any active treatment group. Mean serum total carotenoid levels decreased 14% (P = .07) in the calcium and 9% (P = .10) in the calcium plus vitamin D3 groups. Our results suggest that supplemental calcium alone or combined with vitamin D3 but not vitamin D3 alone may reduce serum lipids and lipophilic micronutrients. Copyright © 2013 Elsevier Inc. All rights reserved.

Calcium Bioavailability from Mineral Waters with Different Mineralization in Comparison to Milk and a Supplement.

PubMed

Greupner, Theresa; Schneider, Inga; Hahn, Andreas

2017-07-01

The aim of the present study was to compare the bioavailability of calcium from 3 mineral waters with different concentrations of minerals with that of milk and a calcium supplement. A single-center, randomized controlled trial with a crossover design with 21 healthy men and women was conducted at the Institute of Food Science and Human Nutrition, Leibniz University Hannover. The participants consumed the 5 test products providing 300 mg of calcium each on 5 examination days with 1-week wash-out phases in between. Primary outcome variables were the area under the curve of serum calcium levels for 10-hour (AUC 0-10h ) and 24-hour urinary calcium excretion. In all groups, no significant differences in the AUC 0-10h of serum calcium levels as well as in the 24-hour urinary calcium excretion were observed. Likewise, mean changes in serum phosphate and urinary phosphate, as well as serum parathormone, showed no differences between the groups. Given an equivalent bioavailability of calcium in all test products, neither a high concentration of SO 4 2- or of HCO 3 influenced the bioavailability of calcium. Accordingly, the use of mineral water with high concentrations of calcium constitutes a calorie-free calcium source that can improve calcium supply.

N-Acetylcysteine-induced vasodilatation is modulated by KATP channels, Na+/K+-ATPase activity and intracellular calcium concentration: An in vitro study.

PubMed

Vezir, Özden; Çömelekoğlu, Ülkü; Sucu, Nehir; Yalın, Ali Erdinç; Yılmaz, Şakir Necat; Yalın, Serap; Söğüt, Fatma; Yaman, Selma; Kibar, Kezban; Akkapulu, Merih; Koç, Meryem İlkay; Seçer, Didem

2017-08-01

In this study, we aimed to investigate the role of ATP-sensitive potassium (K ATP ) channel, Na + /K + -ATPase activity, and intracellular calcium levels on the vasodilatory effect of N-acetylcysteine (NAC) in thoracic aorta by using electrophysiological and molecular techniques. Rat thoracic aorta ring preparations and cultured thoracic aorta cells were divided into four groups as control, 2mM NAC, 5mM NAC, and 10mM NAC. Thoracic aorta rings were isolated from rats for measurements of relaxation responses and Na + /K + -ATPase activity. In the cultured thoracic aorta cells, we measured the currents of K ATP channel, the concentration of intracellular calcium and mRNA expression level of K ATP channel subunits (KCNJ8, KCNJ11, ABCC8 and ABCC9). The relaxation rate significantly increased in all NAC groups compared to control. Similarly, Na + /K + - ATPase activity also significantly decreased in NAC groups. Outward K ATP channel current significantly increased in all NAC groups compared to the control group. Intracellular calcium concentration decreased significantly in all groups with compared control. mRNA expression level of ABCC8 subunit significantly increased in all NAC groups compared to the control group. Pearson correlation analysis showed that relaxation rate was significantly associated with K ATP current, intracellular calcium concentration, Na + /K + -ATPase activity and mRNA expression level of ABCC8 subunit. Our findings suggest that NAC relaxes vascular smooth muscle cells through a direct effect on K ATP channels, by increasing outward K+ flux, partly by increasing mRNA expression of K ATP subunit ABCC8, by decreasing in intracellular calcium and by decreasing in Na + /K + -ATPase activity. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Relationship between blood calcium level and ST peak interval of electrocardiographic variables in peripartum Holstein cows

PubMed Central

ITOH, Megumi; SAKURAI, Yoshie; NAKAJIMA, Yasuhiro; KAWAMOTO, Satoshi

2015-01-01

The association between blood calcium levels and electrocardiographic variables was compared in 137 normal parturient and 36 peripartum recumbent Holstein cows to determine whether hypocalcemia in peripartum dairy cows can be rapidly diagnosed using electrocardiograph. Inverse of STc (ST peak interval/SS interval0.5) and blood ionized calcium or serum calcium concentrations were strongly correlated, and both correlation coefficients were 0.81 (P<0.001). The 95% prediction interval indicated that cows with STc >0.385 ± 0.001 sec are very likely to be hypocalcemic (blood ionized or serum calcium concentrations of <0.9 mmol/l or <7.5 mg/dl, respectively). These findings indicate that hypocalcemia in parturient cows can be non-invasively estimated using the STc. PMID:26118411

Vitamin D, parathyroid hormone, serum calcium and phosphorus in patients with schizophrenia and major depression.

PubMed

Jamilian, Hamidreza; Bagherzadeh, Kamran; Nazeri, Zeinab; Hassanijirdehi, Marzieh

2013-02-01

Vitamin D deficiency has been associated with an increased risk of depression and schizophrenia. The aim was to compare serum levels of vitamin D, calcium, phosphorus and parathyroid hormone in schizophrenics, depressed patients and healthy subjects in an Iranian population. In a cross-sectional study, 100 patients with schizophrenia and 100 with major depression were enrolled. A questionnaire was filled by using medical records of patients. After that a serum sample was taken and levels of vitamin D, calcium, phosphorus and parathyroid hormone were assessed and then compared between the three groups. Post-hoc analysis of Tukey showed that vitamin D level in healthy participants was significantly higher than depressed patients and schizophrenics while there was no significant difference between vitamin D level in depressed and schizophrenic patients. The findings suggest that vitamin D affects the brain independent of hormonal pathways which regulate serum level of calcium. Non-significant difference in the serum level of vitamin D between the schizophrenics and the depressed patients suggests that the independent effect of vitamin D in brain is a general effect and is not specialized to a specific region or pathway in the brain; however, differences between psychiatric and non-psychiatric patients might be resulted from differences in psychosocial backgrounds.

A relationship between vitamin D, parathyroid hormone, calcium levels and lactose intolerance in type 2 diabetic patients and healthy subjects.

PubMed

Rana, SatyaVati; Morya, Rajesh Kumar; Malik, Aastha; Bhadada, Sanjay Kumar; Sachdeva, Naresh; Sharma, Gaurav

2016-11-01

Type 2 diabetes mellitus is chronic metabolic disorder. Common gastrointestinal symptoms in type 2 diabetic patients are flatulence, constipation and/or diarrhea. Reason for these may be lactose intolerance leading to change in vitamin D, Calcium and parathyroid hormone which further regulate bone mineralization. To measure lactose intolerance, vitamin D, calcium and parathyroid hormone in type 2 diabetic patients. 150 type 2 diabetic patients attending Endocrinology Clinic in PGI, Chandigarh and 150 age and sex matched healthy controls were enrolled. Lactose intolerance was measured using non-invasive lactose breath test. 25-hydroxyvitamin D (total) and Parathyroid hormone were measured in plasma using immunoassay. Serum calcium was measured using auto analyzer. T score was recorded from DXA scan for bone mineral density measurement. Lactose intolerance was observed significantly higher (p<0.001) diabetic patients (59.3%) as compared to controls (42%). Levels of plasma 25-OH vitamin D (total), parathyroid hormone and serum calcium were significantly lower in patients as compared to controls. Furthermore, levels of plasma 25-OH vitamin D (total), parathyroid hormone and serum calcium were more decreased in lactose intolerant diabetic patients than lactose tolerant patients. Sixty seven percent (67%) of diabetic patients suffered from osteoporosis and 20% of controls. Eighty percent (80%) diabetic patients and 16% controls with osteoporosis suffered from lactose intolerance. From this study we can conclude that measurement of lactose intolerance using non-invasive lactose breath test is suggested for type 2 diabetic patients along with timely measurement of 25-OH vitamin D (total), calcium and parathyroid hormone levels. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of calcium acetate/magnesium carbonate as a phosphate binder compared with sevelamer hydrochloride in haemodialysis patients: a controlled randomized study (CALMAG study) assessing efficacy and tolerability.

PubMed

de Francisco, Angel L M; Leidig, Michael; Covic, Adrian C; Ketteler, Markus; Benedyk-Lorens, Ewa; Mircescu, Gabriel M; Scholz, Caecilia; Ponce, Pedro; Passlick-Deetjen, Jutta

2010-11-01

Phosphate binders are required to control serum phosphorus in dialysis patients. A phosphate binder combining calcium and magnesium offers an interesting therapeutic option. This controlled randomized, investigator-masked, multicentre trial investigated the effect of calcium acetate/magnesium carbonate (CaMg) on serum phosphorus levels compared with sevelamer hydrochloride (HCl). The study aim was to show non-inferiority of CaMg in lowering serum phosphorus levels into Kidney Disease Outcome Quality Initiative (K/DOQI) target level range after 24 weeks. Three hundred and twenty-six patients from five European countries were included. After a phosphate binder washout period, 255 patients were randomized in a 1:1 fashion. Two hundred and four patients completed the study per protocol (CaMg, N = 105; dropouts N = 18; sevelamer-HCl, N = 99; dropouts N = 34). Patient baseline characteristics were similar in both groups. Serum phosphorus levels had decreased significantly with both drugs at week 25, and the study hypothesis of CaMg not being inferior to sevelamer-HCl was confirmed. The area under the curve for serum phosphorus (P = 0.0042) and the number of visits above K/DOQI (≤1.78 mmol/L, P = 0.0198) and Kidney disease: Improving global outcomes (KDIGO) targets (≤1.45 mmol/L, P = 0.0067) were significantly lower with CaMg. Ionized serum calcium did not differ between groups; total serum calcium increased in the CaMg group (treatment difference 0.0477 mmol/L; P = 0.0032) but was not associated with a higher risk of hypercalcaemia. An asymptomatic increase in serum magnesium occurred in CaMg-treated patients (treatment difference 0.2597 mmol/L, P < 0.0001). There was no difference in the number of patients with adverse events. CaMg was non-inferior to the comparator at controlling serum phosphorus levels at Week 25. There was no change in ionized calcium; there was minimal increase in total serum calcium and a small increase in serum magnesium. It had a good tolerability profile and thus may represent an effective treatment of hyperphosphataemia.

A Prospective Study on Role of Supplemental Oral Calcium and Vitamin D in Prevention of Postthyroidectomy Hypocalcemia.

PubMed

Ravikumar, Krishnan; Sadacharan, Dhalapathy; Muthukumar, Sankaran; Sundarram, Thalavai; Periyasamy, Selladurai; Suresh, R V

2017-01-01

Postoperative transient hypocalcemia is sequelae of total thyroidectomy (TT), which is observed in up to 50% of patients. Routine oral calcium and Vitamin D supplementation have been proposed to prevent symptomatic hypocalcemia preventing morbidity and facilitating early discharge. A total of 208 patients with nontoxic benign thyroid disorders, undergoing TT, were serially randomized into four groups: Group A (no supplements were given), Group B (oral calcium - 2 g/day given), Group C (calcium and calcitriol - 1 mcg/day are given), and Group D (calcium, calcitriol, and cholecalciferol - 60,000 IU/day are given). Patients were monitored for clinical and biochemical hypocalcemia (serum calcium, [Sr. Ca] <8 mg/dl), along with serum intact parathormone (Sr. PTH) and magnesium 6 h after surgery and Sr. Ca every 24 h. Intravenous (IV) calcium infusion was started, if any of the above four groups exhibit frank hypocalcemia. Patients are followed up with Sr. Ca and Sr. PTH at 3 and 6 months. All groups were age and sex matched. Hypocalcemia was observed in 72/208 (34.61%) cases. Incidence of hypocalcemia was higher in Group A (57.69%) and Group B (50%) compared to Group C (15.38%) and Group D (15.38%). Hypocalcemia necessitating IV calcium occurred in 31/208 (14.90%) patients. IV calcium requirement exceeded in Group A (26.92%) and Group B (23.07%) compared to Group C (5.76%) and Group D (3.84%). There was no statistical difference in basal levels of serum Vitamin D, calcium, magnesium, intact PTH, and 6 h after surgery. Permanent hypoparathyroidism developed in five patients on follow-up. Routine postoperative supplementation of oral calcium and Vitamin D will help in the prevention of postthyroidectomy transient hypocalcemia significantly. Preoperative Vitamin D levels do not predict postoperative hypocalcemia.

Calcium Absorption from Fortified Ice Cream Formulations Compared with Calcium Absorption from Milk

PubMed Central

van der Hee, Regine M.; Miret, Silvia; Slettenaar, Marieke; Duchateau, Guus S.M.J.E.; Rietveld, Anton G.; Wilkinson, Joy E.; Quail, Patricia J.; Berry, Mark J.; Dainty, Jack R.; Teucher, Birgit; Fairweather-Tait, Susan J.

2009-01-01

Objective Optimal bone mass in early adulthood is achieved through appropriate diet and lifestyle, thereby protecting against osteoporosis and risk of bone fracture in later life. Calcium and vitamin D are essential to build adequate bones, but calcium intakes of many population groups do not meet dietary reference values. In addition, changes in dietary patterns are exacerbating the problem, thereby emphasizing the important role of calcium-rich food products. We have designed a calcium-fortified ice cream formulation that is lower in fat than regular ice cream and could provide a useful source of additional dietary calcium. Calcium absorption from two different ice cream formulations was determined in young adults and compared with milk. Subjects/setting Sixteen healthy volunteers (25 to 45 years of age), recruited from the general public of The Netherlands, participated in a randomized, reference-controlled, double-blind cross-over study in which two test products and milk were consumed with a light standard breakfast on three separate occasions: a standard portion of ice cream (60 g) fortified with milk minerals and containing a low level (3%) of butter fat, ice cream (60 g) fortified with milk minerals and containing a typical level (9%) of coconut oil, and reduced-fat milk (1.7% milk fat) (200 mL). Calcium absorption was measured by the dual-label stable isotope technique. Statistical analysis Effects on calcium absorption were evaluated by analysis of variance. Results Fractional absorption of calcium from the 3% butterfat ice cream, 9% coconut oil ice cream, and milk was 26%±8%, 28%±5%, and 31%±9%, respectively, and did not differ significantly (P=0.159). Conclusions Results indicate that calcium bioavailability in the two calcium-fortified ice cream formulations used in this study is as high as milk, indicating that ice cream may be a good vehicle for delivery of calcium. PMID:19394469

Preoperative normal level of parathyroid hormone signifies an early and mild form of primary hyperparathyroidism.

PubMed

Bergenfelz, Anders; Lindblom, Pia; Lindergård, Birger; Valdemarsson, Stig; Westerdahl, Johan

2003-04-01

Contemporary patients are often diagnosed with mild or intermittent hypercalcemia. In addition, most studies demonstrate patients with parathyroid (PTH) levels in the upper normal range. The aim of the present investigation was to define subgroups of patients with mild primary hyperparathyroidism (pHPT), which could be of importance in the decision for or against surgical treatment. Two-hundred and eleven patients, operated for pHPT were investigated with biochemical variables known to reflect PTH activity, renal function, and bone mineral content. The preoperative diagnosis of pHPT was based on the presence of hypercalcemia combined with an inappropriate serum concentration of PTH. The mean age of the patients was 64 +/- 14 years and the mean serum level of calcium was 2.78 +/- 0.19 mmol/L. One hundred and sixty-two patients (77%) had raised levels of calcium and PTH the day before surgery (overt pHPT), 25 patients (12%) had a normal level of calcium and a raised PTH level (normal calcium group), and 20 patients (9%) had a raised level of calcium and a normal level of PTH (normal PTH group). In four patients the level of calcium and PTH was normal. Between-group analysis demonstrated no major difference in symptom and signs of pHPT. Except for lower adenoma weight, patients in the normal calcium group did not essentially differ from the patients in the overt pHPT group. However, patients in the normal PTH group were a decade younger, and had better renal function, lower bone turnover, and a preserved bone density compared with patients in the overt pHPT group. In conclusion, the data from the present investigation show that pHPT patients with a preoperative normal PTH level have an early and mild form of the disease. Furthermore, the serum calcium concentration does not reflect disease severity in pHPT.

SECONDARY HYPERPARATHYROIDISM AFTER BARIATRIC SURGERY: TREATMENT IS WITH CALCIUM CARBONATE OR CALCIUM CITRATE?

PubMed Central

BARETTA, Giorgio Alfredo Pedroso; CAMBI, Maria Paula Carlini; RODRIGUES, Arieli Luz; MENDES, Silvana Aparecida

2015-01-01

Background : Bariatric surgery, especially Roux-en-Y gastric bypass, can cause serious nutritional complications arising from poor absorption of essential nutrients. Secondary hyperparathyroidism is one such complications that leads to increased parathyroid hormone levels due to a decrease in calcium and vitamin D, which may compromise bone health. Aim : To compare calcium carbonate and calcium citrate in the treatment of secondary hyperparathyroidism. Method : Patients were selected on the basis of their abnormal biochemical test and treatment was randomly done with citrate or calcium carbonate. Results : After 60 days of supplementation, biochemical tests were repeated, showing improvement in both groups. Conclusion : Supplementation with calcium (citrate or carbonate) and vitamin D is recommended after surgery for prevention of secondary hyperparathyroidism. PMID:26537273

Determination of Sodium, Potassium, Magnesium, and Calcium Minerals Level in Fresh and Boiled Broccoli and Cauliflower by Atomic Absorption Spectrometry

NASA Astrophysics Data System (ADS)

Nerdy

2018-01-01

Vegetables from the cabbage family vegetables consumed by many people, which is known healthful, by eaten raw, boiled, or cooked (stir fry or soup). Vegetables like broccoli and cauliflower contain vitamins, minerals, and fiber. This study aims to determine the decrease percentage of sodium, potassium, magnesium, and calcium minerals level caused by boiled broccoli and cauliflower by atomic absorption spectrometry. Boiled broccoli and cauliflower prepared by given boiled treatment in boiling water for 3 minutes. Fresh and boiled broccoli and cauliflower carried out dry destruction, followed by quantitative analysis of sodium, potassium, magnesium, and calcium minerals respectively at a wavelength of 589.0 nm; 766.5 nm; 285.2 nm; and 422.7 nm, using atomic absorption spectrometry methods. After the determination of the sodium, potassium, magnesium, and calcium minerals level followed by validation of analytical methods with accuracy, precision, linearity, range, limit of detection (LOD), and limit of quantitation (LOQ) parameters. Research results show a decrease in the sodium, potassium, magnesium, and calcium minerals level in boiled broccoli and cauliflower compared with fresh broccoli and cauliflower. Validation of analytical methods gives results that spectrometry methods used for determining sodium, potassium, magnesium, and calcium minerals level are valid. It concluded that the boiled gives the effect of decreasing the minerals level significantly in broccoli and cauliflower.

Calcium intake and serum concentration in relation to risk of cardiovascular death in NHANES III.

PubMed

Van Hemelrijck, Mieke; Michaelsson, Karl; Linseisen, Jakob; Rohrmann, Sabine

2013-01-01

Evidence for an association between calcium intake and risk of cardiovascular death remains controversial. By assessing dietary intake, use of supplements, and serum levels of calcium, we aimed to disentangle this link in the third National Health and Nutrition Examination Survey (NHANES III). Mortality linkage of NHANES III to death certificate data for those aged 17 years or older (n = 20,024) was used to estimate risk of overall cardiovascular death as well as death from ischemic heart disease (IHD), acute myocardial infarction (AMI), heart failure (HF), and cerebrovascular disease (CD) with multivariate Cox proportional hazards regression analysis. About 10.0% of the population died of cardiovascular disease and the majority (5.4%) died of IHD. There was increased risk of overall CVD death for those in the bottom 5% of serum calcium compared to those in the mid 90% (HR: 1.51 (95% CI: 1.03-2.22)). For women there was a statistically significant increased risk of IHD death for those with serum calcium levels in the top 5% compared to those in the mid 90% (HR: 1.72 (95%CI: 1.13-2.61)), whereas in men, low serum calcium was related to increased IHD mortality (HR: 2.32 (95% CI 1.14-3.01), Pinteraction: 0.306). No clear association with CVD death was observed for dietary or supplemental calcium intake. Calcium as assessed by serum concentrations is involved in cardiovascular health, though differential effects by sex may exist. No clear evidence was found for an association between dietary or supplementary intake of calcium and cardiovascular death.

Bone Markers, Calcium Metabolism, and Calcium Kinetics During Extended-Duration Space Flight on the Mir Space Station

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Wastney, Meryl E.; O'Brien, Kimberly O.; Morukov, Boris V.; Larina, Irina M.; Abrams, Steven A.; Davis-Street, Janis E.; Oganov, Victor; Shackelford, Linda C.

2005-01-01

Bone loss is a current limitation for long-term space exploration. Bone markers, calcitropic hormones, and calcium kinetics of crew members on space missions of 4-6 months were evaluated. Spaceflight-induced bone loss was associated with increased bone resorption and decreased calcium absorption. INTRODUCTION: Bone loss is a significant concern for the health of astronauts on long-duration missions. Defining the time course and mechanism of these changes will aid in developing means to counteract these losses during space flight and will have relevance for other clinical situations that impair weight-bearing activity. MATERIALS AND METHODS: We report here results from two studies conducted during the Shuttle-Mir Science Program. Study 1 was an evaluation of bone and calcium biochemical markers of 13 subjects before and after long-duration (4-6 months) space missions. In study 2, stable calcium isotopes were used to evaluate calcium metabolism in six subjects before, during, and after flight. Relationships between measures of bone turnover, biochemical markers, and calcium kinetics were examined. RESULTS: Pre- and postflight study results confirmed that, after landing, bone resorption was increased, as indicated by increases in urinary calcium (p < 0.05) and collagen cross-links (N-telopeptide, pyridinoline, and deoxypyridinoline were all increased >55% above preflight levels, p < 0.001). Parathyroid hormone and vitamin D metabolites were unchanged at landing. Biochemical markers of bone formation were unchanged at landing, but 2-3 weeks later, both bone-specific alkaline phosphatase and osteocalcin were significantly (p < 0.01) increased above preflight levels. In studies conducted during flight, bone resorption markers were also significantly higher than before flight. The calcium kinetic data also validated that bone resorption was increased during flight compared with preflight values (668 +/- 130 versus 427 +/- 153 mg/day; p < 0.001) and clearly documented that true intestinal calcium absorption was significantly lower during flight compared with preflight values (233 +/- 87 versus 460 +/- 47 mg/day; p < 0.01). Weightlessness had a detrimental effect on the balance in bone turnover such that the daily difference in calcium retention during flight compared with preflight values approached 300 mg/day (-234 +/- 102 versus 63 +/- 75 mg/day; p < 0.01). CONCLUSIONS: These bone marker and calcium kinetic studies indicated that the bone loss that occurs during space flight is a consequence of increased bone resorption and decreased intestinal calcium absorption.

Aluminum hydroxide, calcium carbonate and calcium acetate in chronic intermittent hemodialysis patients.

PubMed

Janssen, M J; van der Kuy, A; ter Wee, P M; van Boven, W P

1996-02-01

Prevention of secondary hyperparathyroidism in uremia necessitates correction of hyperphosphatemia and hypocalcemia. In order to avoid aluminum toxicity, calcium containing phosphate binders are used increasingly, instead of aluminium hydroxide. Recent studies have shown that calcium acetate has many characteristics of an ideal phosphate binder. It is, for instance, a more readily soluble salt compared with calcium carbonate. This advantage might, however, disappear if calcium carbonate is taken on an empty stomach, a few minutes before meals. We examined the efficacy of three different phosphate binding agents in a randomized prospective study of 53 patients on regular hemodialysis. Bicarbonate dialyses were performed with a dialysate calcium concentration of 1.75 mmol/l. After a three-week wash-out period, patients received either aluminum hydroxide (control group), calcium acetate, or calcium carbonate as their phosphate binder. Patients were instructed to take the calcium salts a few minutes before meals on an empty stomach, and aluminum hydroxide during meals. Serum calcium, phosphate, intact parathormone, and alkaline phosphatase levels were determined every month. Patient compliance was estimated every month by asking the patients which phosphate binder and what daily dose they had used. Aluminum hydroxide tended to be the most effective phosphate binder. The mean +/- SEM required daily dose of calcium acetate at 12 months was 5.04 +/- 0.60 g, corresponding to 10.1 +/- 1.20 tablets of 500 mg. Co-medication with aluminum hydroxide, however, was needed (1.29 +/- 0.54 g per day, corresponding to 2.6 +/- 1.08 tablets of 500 mg). The required daily calcium carbonate dose appeared to be 2.71 +/- 0.48 g, corresponding to 5.4 +/- 0.95 capsules of 500 mg, with an adjuvant daily aluminum hydroxide dose of 0.69 +/- 0.27 g, corresponding to 1.4 +/- 0.55 tablets of 500 mg (p = 0.0055). Thus, the mean daily doses of elemental calcium were comparable between the calcium acetate and calcium carbonate-treated patients (1.28 +/- 0.15 g versus 1.09 +/- 0.19 g; n.s.). The incidence of hypercalcemic episodes (albumin-corrected serum calcium levels above 2.80 mmol/l) in the calcium acetate-treated group was 18% versus 31% in the calcium carbonate-treated group (p < 0.005). None of the aluminum hydroxide-treated patients experienced hypercalcemic episodes. Mean serum concentrations of alkaline phosphatase, intact parathormone, and aluminum did not differ between the groups. In chronic intermittent hemodialysis patients, per gram administered elemental calcium phosphate binding with either calcium acetate or calcium carbonate is equivalent, provided that calcium carbonate is taken on an empty stomach a few minutes before meals. The number of capsules calcium carbonate, but also the total amount in grams, necessary to keep serum phosphate and intact parathormone levels into an acceptable range then is significantly less. This might improve patient compliance.

The effect of CPP-ACP-propolis chewing gum on calcium and phosphate ion release on caries-active subjects’ saliva and the formation of Streptococcus mutans biofilm

NASA Astrophysics Data System (ADS)

Hasnamudhia, F.; Bachtiar, E. W.; Sahlan, M.; Soekanto, S. A.

2017-08-01

The aim of this study was to analyze the effect of CPP-APP and propolis wax if they are combined in a chewing gum formulation, observed from the calcium and phosphate ion level released by CPP-ACP and the emphasis of Streptococcus mutans mass in the biofilm by propolis wax on caries-active subjects’ saliva. Chewing gum simulation was done in vitro on 25 caries-active subjects’ saliva using five concentrations of chewing gum (0% propolis + 0% CPP-ACP, 0% propolis + CPP-ACP, 2% propolis + CPP-ACP, 4% propolis + CPP-ACP, and 6% propolis + CPP-ACP) and was then tested using an atomic absorption spectrophotometer to analyze calcium ion levels, an ultraviolet-visible spectrophotometer to analyze phosphate ion levels, and a biofilm assay using crystal violet to analyze the decline in biofilm mass. After the chewing simulation, calcium ion levels on saliva+gum eluent increased significantly compared to the saliva control, with the highest calcium level released by CPP-ACP + 2% propolis chewing gum. There was an insignificant phosphate level change between the saliva control and saliva+gum eluent. There was also a significant decline of S. mutans biofilm mass in the saliva+gum eluent, mostly by the CPP-ACP chewing gum and CPP-ACP + 6% propolis. The CPP-ACP-propolis chewing gum simulation generated the largest increase in calcium and phosphate ion level and the largest decline in S. mutans biofilm mass.

Calcium and vitamin D disparities are related to gender, age, race, household income level, and weight classification but not vegetarian status in the United States: Analysis of the NHANES 2001-2008 data set.

PubMed

Wallace, Taylor C; Reider, Carroll; Fulgoni, Victor L

2013-01-01

Adequate calcium and vitamin D intakes are critical during all life cycle stages. This study aimed to characterize usual intakes of calcium and vitamin D from food and dietary supplements in specific subpopulations of Americans so that fortification/enrichment and supplementation efforts may be targeted toward populations who are truly in need. The National Cancer Institute method was used to estimate usual intakes of calcium and vitamin D by source and compared usual intakes to the established Dietary Reference Intakes for U.S. residents aged ≥4 years using National Health and Nutrition Examination Survey 2001-2002, 2003-2004, 2005-2006, and 2007-2008 data sets. These results showed for the first time that low-income, overweight, and/or obese minority populations may be at greater risk of calcium and vitamin D insufficiency. Children aged 4-8 years were more likely to obtain recommended dairy intakes compared with older children and adults of all ages. Food intakes of calcium decreased with age in adults. Adults who used supplemental calcium showed a lower prevalence of insufficiency. Calcium and vitamin D intakes from food and dietary supplements were not related to vegetarian status. Excessive intakes of calcium and vitamin D above the tolerable upper intake level were low among all studied populations and "overnutrification" was not widely present across these analyses. Age- and gender-specific supplementation and modest use of fortification with calcium and vitamin D may be warranted for targeting certain subpopulations, particularly older adults, teenagers, minorities, and those who are low income and overweight and/or obese. This study aimed to characterize usual intakes of calcium and vitamin D from food and dietary supplements in specific subpopulations of Americans so that fortification/enrichment and supplementation efforts may be better targeted. Low-income, overweight, and/or obese minority populations may be at a greater risk of calcium and vitamin D insufficiency.

Effects of Hydration and Calcium Supplementation on Urine Calcium Concentration in Healthy Postmenopausal Women.

PubMed

Harris, Susan S; Dawson-Hughes, Bess

2015-01-01

The aim of this study was to determine whether calcium supplementation, compared with placebo, increases urine calcium concentrations to levels indicative of increased renal stone risk, and the role that fluid intake, as indicated by urine volume, may play in mitigating this risk. This is a secondary analysis of data from a randomized placebo-controlled trial of 500 mg/d calcium supplementation to prevent bone loss. Subjects were 240 white postmenopausal women age 40 to 70 years in good general health. Effects of supplementation on 1-year changes in 24h urine calcium concentration and urine volume were examined. Both treatment group and urine volume were strong independent predictors of urine calcium concentration (p < 0.001). Among subjects with urine volume under 2 L/24 h, more than half of placebo subjects were at lowest risk for renal stones compared with less than 35% of calcium-supplemented subjects. Among those with higher urine volumes, all placebo subjects and more than 80% of calcium supplemented subjects were at lowest risk. The increased risk of renal stones with calcium supplement use may be largely eliminated with adequate fluid intake, but older adults may not spontaneously consume adequate fluids to minimize this risk and should be counseled to do so.

Assay of calcium borogluconate veterinary medicines for calcium gluconate, boric acid, phosphorus, and magnesium by using inductively coupled plasma emission spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyons, D.J.; Spann, K.P.

1985-03-01

An inductively coupled plasma spectrometric method is described for the determination of 4 elements (Ca, B, P, and Mg) in calcium borogluconate veterinary medicines. Samples are diluted, acidified, and sprayed directly into the plasma. Reproducibility relative confidence intervals for a single sample assay are +/- 1.4% (calcium), +/- 1.8% (boron), +/- 2.6% (phosphorus), and +/- 1.4% (magnesium). The total element concentrations for each of 4 elements compared favorably with concentrations determined by alternative methods. Formulation estimates of levels of calcium gluconate, boric acid, phosphorus, and magnesium salts can be made from the analytical data.

Electrolyte status in birth asphyxia.

PubMed

Basu, Pallab; Som, Sabyasachi; Das, Harendranath; Choudhuri, Nabendu

2010-03-01

To study electrolyte status in asphyxiated newborns of different severity in early neonatal period and compare with controls. Sodium, potassium and total calcium levels were estimated in the serum samples of asphyxiated newborns of different severity and control group immediately after birth. Mean serum sodium level was significantly lower (122.1 +/- 6.0 mEq/L vs 138.8 +/- 2.7 mEq/L; P < 0.001), mean serum potassium was higher (5.05 +/- 0.63 mEq/L vs 4.19 +/- 0.40 mEq/L; P < 0.001) and mean serum calcium level was found lower (6.85 +/- 0.95 mg/dl vs 9.50 +/- 0.51 mg/dl; P < 0.001) in cases than controls. Among cases, a strong positive linear correlation was found between the serum sodium, serum calcium levels and their Apgar scores, between sodium levels and total calcium levels and significant negative linear correlation between Apgar scores and serum potassium level. Among cases, hyponatremia and hypocalcemia developed early and simultaneously and the decrease in their serum levels was directly proportional to each other and to the degree of asphyxia. Though, mean potassium level was within the normal limit, the value was higher among cases than controls and directly proportional to asphyxia.

Comparison of the Absorption of Calcium Carbonate and Calcium Citrate after Roux-en-Y Gastric Bypass

PubMed Central

Tondapu, P.; Provost, D.; Adams-Huet, B.; Sims, T.; Chang, C.; Sakhaee, K.

2015-01-01

Introduction Roux-en-Y gastric bypass (RYGB) restricts food intake. Consequently, patients consume less calcium. In addition, food no longer passes through the duodenum, the main site of calcium absorption. Therefore, calcium absorption is significantly impaired. The goal of this study is to compare two common calcium supplements in gastric bypass patients. Method Nineteen patients were enrolled in a randomized, double-blinded, crossover study comparing the absorption of calcium from calcium carbonate and calcium citrate salts. Serum and urine calcium levels were assessed for peak values (Cmax) and cumulative calcium increment (area under the curve [AUC]). Serum PTH was assessed for minimum values (PTHmin) and cumulative PTH decrement (AUC). Statistical analysis was performed using a repeated analysis of variance model. Results Eighteen subjects completed the study. Calcium citrate resulted in a significantly higher serum Cmax (9.4+0.4 mg/dl vs. 9.2+0.3 mg/dl, p=0.02) and serum AUC (55+2 mg/dl vs. 54+2 mg/dl, p=0.02). Calcium citrate resulted in a significantly lower PTHmin (24+11 pg/ml vs. 30+13 pg/ml, p=0.01) and a higher AUC (−32+51 pg/ml vs. −3+56 pg/ml, p=0.04). There was a non-significant trend for higher urinary AUC in the calcium citrate group (76.13+36.39 mg/6 h vs. 66.04+40.82, p=0.17). Conclusion Calcium citrate has superior bioavailability than calcium carbonate in RYGB patients. PMID:19437082

Lipid body accumulation alters calcium signaling dynamics in immune cells

PubMed Central

Greineisen, William E.; Speck, Mark; Shimoda, Lori M.N.; Sung, Carl; Phan, Nolwenn; Maaetoft-Udsen, Kristina; Stokes, Alexander J.; Turner, Helen

2014-01-01

Summary There is well-established variability in the numbers of lipid bodies (LB) in macrophages, eosinophils, and neutrophils. Similarly to the steatosis observed in adipocytes and hepatocytes during hyperinsulinemia and nutrient overload, immune cell LB hyper-accumulate in response to bacterial and parasitic infection and inflammatory presentations. Recently we described that hyperinsulinemia, both in vitro and in vivo, drives steatosis and phenotypic changes in primary and transformed mast cells and basophils. LB reach high numbers in these steatotic cytosols, and here we propose that they could dramatically impact the transcytoplasmic signaling pathways. We compared calcium release and influx responses at the population and single cell level in normal and steatotic model mast cells. At the population level, all aspects of FcεRI-dependent calcium mobilization, as well as activation of calcium-dependent downstream signalling targets such as NFATC1 phosphorylation are suppressed. At the single cell level, we demonstrate that LB are both sources and sinks of calcium following FcεRI cross-linking. Unbiased analysis of the impact of the presence of LB on the rate of trans-cytoplasmic calcium signals suggest that LB enrichment accelerates calcium propagation, which may reflect a Bernoulli effect. LB abundance thus impacts this fundamental signalling pathway and its downstream targets. PMID:25016314

Regulation of Bicarbonate Secretion in Marine Fish Intestine by the Calcium-Sensing Receptor.

PubMed

Gregório, Sílvia F; Fuentes, Juan

2018-04-04

In marine fish, high epithelial intestinal HCO₃ − secretion generates luminal carbonate precipitates of divalent cations that play a key role in water and ion homeostasis. The present study was designed to expose the putative role for calcium and the calcium-sensing receptor (CaSR) in the regulation of HCO₃ − secretion in the intestine of the sea bream ( Sparus aurata L.). Effects on the expression of the CaSR in the intestine were evaluated by qPCR and an increase was observed in the anterior intestine in fed fish compared with unfed fish and with different regions of intestine. CaSR expression reflected intestinal fluid calcium concentration. In addition, anterior intestine tissue was mounted in Ussing chambers to test the putative regulation of HCO₃ − secretion in vitro using the anterior intestine. HCO₃ − secretion was sensitive to varying calcium levels in luminal saline and to calcimimetic compounds known to activate/block the CaSR i.e., R 568 and NPS-2143. Subsequent experiments were performed in intestinal sacs to measure water absorption and the sensitivity of water absorption to varying luminal levels of calcium and calcimimetics were exposed as well. It appears, that CaSR mediates HCO₃ − secretion and water absorption in marine fish as shown by responsiveness to calcium levels and calcimimetic compounds.

Deterioration of teeth and alveolar bone loss due to chronic environmental high-level fluoride and low calcium exposure.

PubMed

Simon, Maciej J K; Beil, Frank Timo; Riedel, Christoph; Lau, Grace; Tomsia, Antoni; Zimmermann, Elizabeth A; Koehne, Till; Ueblacker, Peter; Rüther, Wolfgang; Pogoda, Pia; Ignatius, Anita; Amling, Michael; Oheim, Ralf

2016-12-01

Health risks due to chronic exposure to highly fluoridated groundwater could be underestimated because fluoride might not only influence the teeth in an aesthetic manner but also seems to led to dentoalveolar structure changes. Therefore, we studied the tooth and alveolar bone structures of Dorper sheep chronically exposed to very highly fluoridated and low calcium groundwater in the Kalahari Desert in comparison to controls consuming groundwater with low fluoride and normal calcium levels within the World Health Organization (WHO) recommended range. Two flocks of Dorper ewes in Namibia were studied. Chemical analyses of water, blood and urine were performed. Mineralized tissue investigations included radiography, HR-pQCT analyses, histomorphometry, energy-dispersive X-ray spectroscopy and X-ray diffraction-analyses. Fluoride levels were significantly elevated in water, blood and urine samples in the Kalahari group compared to the low fluoride control samples. In addition to high fluoride, low calcium levels were detected in the Kalahari water. Tooth height and mandibular bone quality were significantly decreased in sheep, exposed to very high levels of fluoride and low levels of calcium in drinking water. Particularly, bone volume and cortical thickness of the mandibular bone were significantly reduced in these sheep. The current study suggests that chronic environmental fluoride exposure with levels above the recommended limits in combination with low calcium uptake can cause significant attrition of teeth and a significant impaired mandibular bone quality. In the presence of high fluoride and low calcium-associated dental changes, deterioration of the mandibular bone and a potential alveolar bone loss needs to be considered regardless whether other signs of systemic skeletal fluorosis are observed or not.

Calcium glycerophosphate and caries: a review of the literature.

PubMed

Lynch, R J M

2004-01-01

To review studies in the dental literature regarding the anti-caries mode of action of glycerophosphate with special reference to calcium glycerophosphate. The cariostatic properties of calcium glycerophosphate have been demonstrated during numerous in vivo and in vitro studies. Several mechanisms have been suggested and these include plaque-pH buffering, elevation of plaque calcium and phosphate levels and direct interaction with dental mineral. There is credible evidence that calcium glycerophosphate has the potential to reduce the progression of caries via all of these mechanisms if it is applied frequently and at a sufficiently high concentration. Reduction of plaque mass has also been proposed as a cariostatic mechanism but this seems less likely. Animal studies have shown that the calcium glycerophosphate/sodium monofluorophosphate system can have a greater anti-caries effect than sodium monofluorophosphate alone and this was subsequently confirmed in a caries clinical trial. We conclude that elevation of calcium levels in plaque is the most likely explanation and that any means of enhancing this effect has significant promise as a means to further increase in anti-caries potential of the calcium glycerophosphate/sodium monofluorophosphate system compared to sodium monofluorophosphate alone.

The value of hypercalciuria in patients with osteopenia versus osteoporosis.

PubMed

Girón-Prieto, María Sierra; Del Carmen Cano-García, María; Poyatos-Andújar, Antonio; Arias-Santiago, Salvador; de Haro-Muñoz, Tomás; Arrabal-Martín, Miguel; Arrabal-Polo, Miguel Ángel

2017-06-01

The aim of this study was to analyze the presence of lithogenic metabolic factors in the blood and urine of patients with osteopenia versus osteoporosis. This is a cross-sectional study including 67 patients who were divided into two groups according to the presence of either osteopenia or osteoporosis as measured by bone densitometry: group 1-40 patients with osteopenia (22 men and 18 women) and group 2-27 patients with osteoporosis (13 men and 14 women). Metabolic studies were performed on the blood and urine; statistical analysis was performed comparing means and conducting linear correlation and multivariate analyses with SPSS. Statistical significance was considered to be p ≤ 0.05. The mean age of patients in group 1 was 52.9 ± 12.8 years versus 50.3 ± 11.4 in group 2; the difference was not statistically significant. In group 2, higher levels of osteocalcin, β-crosslaps, urinary calcium, fasting urine calcium/creatinine, 24 h urine calcium/creatinine and 24 h oxaluria were observed compared to group 1. In the multivariate analysis, only the β-crosslaps and urinary calcium were independently associated with osteoporosis. It would be advisable to determine the urinary calcium levels in patients with osteoporosis since altered levels may necessitate modifying the diagnostic and therapeutic approach to osteoporosis.

[The fasting calcium/creatinine ratio in patients with calcium stones and the relation with hypercalciuria and phosphocalcium metabolism].

PubMed

Arrabal-Polo, Miguel Ángel; del Carmen Cano-García, María; Arrabal-Martín, Miguel

2016-04-01

To determine the importance of fasting calcium/creatinine ratio in patients with calcium stones and its relation with hypercalciuria and phospho-calcium metabolism. Cross-sectional study including 143 patients divided into two groups according to fasting calcium/creatinine. Group 1: 66 patients (calcium/ creatinine<0.11); Group 2: 77 patients (calcium/ creatinine>0.11). A comparative study is performed between groups including phospho-calcium metabolism parameters and excretion of urinary lithogenic markers. Linear correlation studying calciuria and fasting calcium/ creatinine was performed. SPSS 17.0 statistical analysis software was used, considering p≤0.05. It is noteworthy that group 2 had increased 24 h urine calcium excretion in comparison to group 1 (229.3 vs 158.1; p=0.0001) and calcium/citrate (0.47 vs 0.34; p=0.001). There is a positive and significant correlation between calcium levels in 24 h urine and fasting calcium/creatinine (R=0.455; p=0.0001) and a cutoff is set at 0.127 (sensitivity 72%, specificity 66%) to determine hypercalciuria (>260 mg in 24 h). Increased fasting calcium/creatinine determines increased 24 hours calcium excretion, although the sensitivity and specificity to determine hypercalciuria is not high.

A Prospective Study on Role of Supplemental Oral Calcium and Vitamin D in Prevention of Postthyroidectomy Hypocalcemia

PubMed Central

Ravikumar, Krishnan; Sadacharan, Dhalapathy; Muthukumar, Sankaran; Sundarram, Thalavai; Periyasamy, Selladurai; Suresh, R. V.

2017-01-01

Background: Postoperative transient hypocalcemia is sequelae of total thyroidectomy (TT), which is observed in up to 50% of patients. Routine oral calcium and Vitamin D supplementation have been proposed to prevent symptomatic hypocalcemia preventing morbidity and facilitating early discharge. Patients and Methods: A total of 208 patients with nontoxic benign thyroid disorders, undergoing TT, were serially randomized into four groups: Group A (no supplements were given), Group B (oral calcium – 2 g/day given), Group C (calcium and calcitriol – 1 mcg/day are given), and Group D (calcium, calcitriol, and cholecalciferol – 60,000 IU/day are given). Patients were monitored for clinical and biochemical hypocalcemia (serum calcium, [Sr. Ca] <8 mg/dl), along with serum intact parathormone (Sr. PTH) and magnesium 6 h after surgery and Sr. Ca every 24 h. Intravenous (IV) calcium infusion was started, if any of the above four groups exhibit frank hypocalcemia. Patients are followed up with Sr. Ca and Sr. PTH at 3 and 6 months. Results: All groups were age and sex matched. Hypocalcemia was observed in 72/208 (34.61%) cases. Incidence of hypocalcemia was higher in Group A (57.69%) and Group B (50%) compared to Group C (15.38%) and Group D (15.38%). Hypocalcemia necessitating IV calcium occurred in 31/208 (14.90%) patients. IV calcium requirement exceeded in Group A (26.92%) and Group B (23.07%) compared to Group C (5.76%) and Group D (3.84%). There was no statistical difference in basal levels of serum Vitamin D, calcium, magnesium, intact PTH, and 6 h after surgery. Permanent hypoparathyroidism developed in five patients on follow-up. Conclusion: Routine postoperative supplementation of oral calcium and Vitamin D will help in the prevention of postthyroidectomy transient hypocalcemia significantly. Preoperative Vitamin D levels do not predict postoperative hypocalcemia. PMID:28670529

Photoreception and signal transduction in corals: proteomic and behavioral evidence for cytoplasmic calcium as a mediator of light responsivity.

PubMed

Hilton, J Daniel; Brady, Aisling K; Spaho, Skender A; Vize, Peter D

2012-12-01

Little is known about how corals sense and respond to light. In this report the proteome of coral is explored using 2D protein electrophoresis in two species, Montastraea cavernosa and Acropora millepora. Multiple protein species have major shifts in abundance in both species when sampled in daylight compared to corals sampled late in the night. These changes were observed both in larvae lacking zooxanthellae and in adult tissue containing zooxanthellae, including both Pacific and Caribbean corals. When larvae kept in the dark were treated with either thapsigargin or ionomycin, compounds that raise the level of cytoplasmic calcium, the night pattern of proteins shifted to the day pattern. This implies that photoreceptors responding to light elevate calcium levels and that calcium acts as the second messenger relaying light responses in corals. Corals spawn at night, and spawning can be delayed by exposure to light or pushed forward by early artificial sunsets. In a series of behavioral experiments, treatment of corals with ionomycin or thapsigargin was found to delay broadcast spawning in M. franksi, demonstrating that pharmacologically altering cytoplasmic calcium levels generates the same response as light exposure. Together these results show that the photo-responsive cells of corals detect and respond to light by altering cytoplasmic calcium levels, similarly to the transduction pathways in complex invertebrate eyes. The primacy of cytoplasmic calcium levels in light responsivity has broad implications for coral reproduction, including predicting how different species spawn at different times after sunset and how reproductive isolation is achieved during coral speciation.

Prediction of calcium level in melamine-related urinary calculi with helical CT: diagnostic performance evaluation and clinical significance.

PubMed

Yuan, Li; Xiaorui, Ru; Gang, Huang; Xinsheng, Xi; Xiaogang, Huang; Li, Dong; Yirong, Chen

2012-06-01

The aim of the study was to investigate the relationship between CT-attenuation and stone calcium level in melamine-related urinary calculi (MRUC). A total of 25 MRUC with known composition and calcium level were included (11 uric acid stones, 2 calcium oxalate stones and 12 mixture stones of uric acid and calcium oxalate). Of all, 18 renal stones accepted alkalization therapy except for 5 lower urinary tract stones and 2 stones of unknown position. With well-matched composition, 61 adult urinary stones were included as controls. Every stone was scanned by helical CT (80 kV/120 kV, 300 mA, pitch 0.625 mm) and the highest CT-attenuation value measured. CT-attenuation values of MRUC increased gradually from uric acid stones, mixture stones to calcium oxalate stones, but were always lower than the values of controls. Furthermore, a strong positive correlation was found between stone CT-attenuation value and stone calcium level (n = 25, r (80kV) = 0.883, p = 0.000; r (120kV) = 0.855, p = 0.000). Compared with alkalization-therapy-alone group, stone CT-attenuation values and stone calcium level in the comprehensive-therapy group were significantly greater (CT(80kV) 1,057 ± 639 vs. 172 ± 61 HU, p = 0.001; CT(120kV) 783 ± 476 vs. 162 ± 60 HU, p = 0.001; Ca 19.83 ± 7.48% vs. 1.30 ± 1.51%, p = 0.000). Fisher's exact test suggested that the stones with higher CT-attenuation values tended to resist alkalization when 400 HU served as the cutoff value (P (80kV) = 0.002, P (120kV) = 0.000). In conclusion, the study was the first to illustrate that the CT-attenuation value could reflect calcium level in MRUC and found that stones with higher CT-attenuation value were not amenable to alkalization because they probably contained greater calcium. For those patients, we believe that comprehensive therapy will be the best choice.

Calcium Supplement Intake and Risk of Cardiovascular Disease in Women

PubMed Central

Paik, Julie M.; Curhan, Gary C.; Sun, Qi; Rexrode, Kathryn M.; Manson, JoAnn E.; Rimm, Eric B.; Taylor, Eric N.

2014-01-01

Background Some recent reports suggest that calcium supplements may increase cardiovascular disease (CVD) risk. Purpose The objective was to examine the independent associations between calcium supplement use and risk of CVD. Methods We conducted a prospective cohort study of supplemental calcium use and incident CVD in 74,245 women in the Nurses' Health Study (1984–2008) free of CVD and cancer at baseline. Calcium supplement intake was assessed every four years. Outcomes were incident coronary heart disease (CHD) (nonfatal or fatal MI) and stroke (ischemic or hemorrhagic), confirmed by medical record review. Results During 24 years of follow-up, 4,565 cardiovascular events occurred (2,709 CHD and 1,856 strokes). At baseline, women who took calcium supplements had higher levels of physical activity, smoked less, and had lower trans fat intake compared with those who did not take calcium supplements. After multivariable adjustment for age, body mass index, dietary calcium, vitamin D intake, and other CVD risk factors, the relative risk of CVD for women taking >1,000mg/day of calcium supplements compared with none was 0.82 (95% CI 0.74 to 0.92; p for trend <0.001). For women taking >1,000mg/day of calcium supplements compared with none, the multivariable-adjusted relative risk for CHD was 0.71 (0.61 to 0.83; p for trend<0.001) and for stroke was 1.03 (0.87 to 1.21; p for trend=0.61). The relative risks were similar in analyses limited to non-smokers, women without hypertension, and women who had regular physical exams. Conclusions Our findings do not support the hypothesis that calcium supplement intake increases CVD risk in women. PMID:24803331

A pooled analysis to define vitamin D dose requirements for fracture prevention in seniors

USDA-ARS?s Scientific Manuscript database

Meta-analyses reached conflicting results regarding vitamin D and fracture reduction. We pooled individual participant-level data from 11 double-blind RCTs of oral vitamin D supplementation (daily, weekly, 4-monthly) with or without calcium compared with placebo or calcium in seniors age 65 and olde...

Umbilical cord vitamin D, ionized calcium and myocardial oxygen demand.

PubMed

Reeves, Inez; Liang, Willie; Asadi, M Sadegh; Millis, Richard M

2014-07-01

Systemic blood vitamin D and total calcium are correlates of birthweight and cardiovascular disease but whether umbilical cord blood vitamin D and ionized calcium are correlates of birthweight and cardiovascular function is not known. This cross-sectional study correlates umbilical cord vitamin D, ionized calcium and birthweight with the heart rate-systolic pressure product (RPP), an indicator of myocardial oxygen demand. Cord blood vitamin D and ionized calcium concentrations were compared for vitamin D normal (≥50 nM, 20 ng/mL) and vitamin D deficiency (<50 nM, 20 ng/mL) in normal weight (≥2500 g) and low birthweight (LBW, <2500 g) newborns. Heart rate and blood pressure were measured during postnatal transition and RPP was computed. RPP was positively correlated with birthweight (r = +0.52, p < 0.001) and with cord ionized calcium level (r = +0.42, p < 0.01) in the normal and LBW newborns. RPP was positively correlated with cord vitamin D level in the LBW newborns (raw r = +0.50, p < 0.05, normalized for birthweight r = +0.73, p < 0.01). Small RPP, an indicator of low myocardial oxygen demand, in LBW newborns appears to correlate with low umbilical cord vitamin D and ionized calcium levels, suggestive of pathological heart development.

Retention in plaque and remineralization of enamel lesions by various forms of calcium in a mouthrinse or sugar-free chewing gum.

PubMed

Reynolds, E C; Cai, F; Shen, P; Walker, G D

2003-03-01

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) nanocomplexes incorporated into sugar-free chewing gum have been shown to remineralize enamel subsurface lesions in situ. The aim of this study was to compare the ability of CPP-ACP, with that of other forms of calcium, to be retained in supragingival plaque and remineralize enamel subsurface lesions in situ when delivered in a mouthrinse or sugar-free gum in randomized, double-blind trials. In the mouthrinse study, only the CPP-ACP-containing mouthrinse significantly increased plaque calcium and inorganic phosphate levels, and the CPP were immunolocalized to the surfaces of bacterial cells as well as the intercellular matrix. In the chewing gum studies, the gum containing the CPP-ACP, although not containing the most calcium per piece of gum, produced the highest level of enamel remineralization independent of gum-chewing frequency and duration. The CPP could be detected in plaque extracts 3 hrs after subjects chewed the CPP-ACP-containing gum. The results showed that CPP-ACP were superior to other forms of calcium in remineralizing enamel subsurface lesions.

The Phosphate Binder Ferric Citrate and Mineral Metabolism and Inflammatory Markers in Maintenance Dialysis Patients: Results From Prespecified Analyses of a Randomized Clinical Trial

PubMed Central

Van Buren, Peter N.; Lewis, Julia B.; Dwyer, Jamie P.; Greene, Tom; Middleton, John; Sika, Mohammed; Umanath, Kausik; Abraham, Josephine D.; Arfeen, Shahabul S.; Bowline, Isai G.; Chernin, Gil; Fadem, Stephen Z.; Goral, Simin; Koury, Mark; Sinsakul, Marvin V.; Weiner, Daniel E.

2016-01-01

Background Phosphate binders are the cornerstone of hyperphosphatemia management in dialysis patients. Ferric citrate is an iron-based oral phosphate binder that effectively lowers serum phosphorus levels. Study Design 52-week, open-label, phase 3, randomized, controlled trial for safety-profile assessment. Setting & Participants Maintenance dialysis patients with serum phosphorus levels ≥6.0 mg/dL after washout of prior phosphate binders. Intervention 2:1 randomization to ferric citrate or active control (sevelamer carbonate and/or calcium acetate). Outcomes Changes in mineral bone disease, protein-energy wasting/inflammation, and occurrence of adverse events after 1 year. Measurements Serum calcium, intact parathyroid hormone, phosphorus, aluminum, white blood cell count, percentage of lymphocytes, serum urea nitrogen, and bicarbonate. Results There were 292 participants randomly assigned to ferric citrate, and 149, to active control. Groups were well matched. For mean changes from baseline, phosphorus levels decreased similarly in the ferric citrate and active control groups (−2.04 ± 1.99 [SD] vs −2.18 ± 2.25 mg/dL, respectively; P = 0.9); serum calcium levels increased similarly in the ferric citrate and active control groups (0.22 ± 0.90 vs 0.31 ± 0.95 mg/dL; P = 0.2). Hypercalcemia occurred in 4 participants receiving calcium acetate. Parathyroid hormone levels decreased similarly in the ferric citrate and active control groups (−167.1 ± 399.8 vs −152.7 ± 392.1 pg/mL; P = 0.8). Serum albumin, bicarbonate, serum urea nitrogen, white blood cell count and percentage of lymphocytes, and aluminum values were similar between ferric citrate and active control. Total and low-density lipoprotein cholesterol levels were lower in participants receiving sevelamer than those receiving ferric citrate and calcium acetate. Fewer participants randomly assigned to ferric citrate had serious adverse events compared with active control. Limitations Open-label study, few peritoneal dialysis patients. Conclusions Ferric citrate was associated with similar phosphorus control compared to active control, with similar effects on markers of bone and mineral metabolism in dialysis patients. There was no evidence of protein-energy wasting/inflammation or aluminum toxicity, and fewer participants randomly assigned to ferric citrate had serious adverse events. Ferric citrate is an effective phosphate binder with a safety profile comparable to sevelamer and calcium acetate. PMID:25958079

Calcium supplement intake and risk of cardiovascular disease in women.

PubMed

Paik, J M; Curhan, G C; Sun, Q; Rexrode, K M; Manson, J E; Rimm, E B; Taylor, E N

2014-08-01

Some recent reports suggest that calcium supplement use may increase risk of cardiovascular disease. In a prospective cohort study of 74,245 women in the Nurses' Health Study with 24 years of follow-up, we found no independent associations between supplemental calcium intake and risk of incident coronary heart disease (CHD) and stroke. Some recent reports suggest that calcium supplements may increase cardiovascular disease (CVD) risk. The objective was to examine the independent associations between calcium supplement use and risk of CVD. We conducted a prospective cohort study of supplemental calcium use and incident CVD in 74,245 women in the Nurses' Health Study (1984-2008) free of CVD and cancer at baseline. Calcium supplement intake was assessed every 4 years. Outcomes were incident CHD (nonfatal or fatal MI) and stroke (ischemic or hemorrhagic), confirmed by medical record review. During 24 years of follow-up, 4,565 cardiovascular events occurred (2,709 CHD and 1,856 strokes). At baseline, women who took calcium supplements had higher levels of physical activity, smoked less, and had lower trans fat intake compared with those who did not take calcium supplements. After multivariable adjustment for age, body mass index, dietary calcium, vitamin D intake, and other CVD risk factors, the relative risk of CVD for women taking >1,000 mg/day of calcium supplements compared with none was 0.82 (95% confidence interval [CI] 0.74 to 0.92; p for trend <0.001). For women taking >1,000 mg/day of calcium supplements compared with none, the multivariable-adjusted relative risk for CHD was 0.71 (0.61 to 0.83; p for trend < 0.001) and for stroke was 1.03 (0.87 to 1.21; p for trend = 0.61). The relative risks were similar in analyses limited to non-smokers, women without hypertension, and women who had regular physical exams. Our findings do not support the hypothesis that calcium supplement intake increases CVD risk in women.

Nephrogenic systemic fibrosis is associated with hypophosphataemia: a case-control study.

PubMed

Bernstein, Elana J; Isakova, Tamara; Sullivan, Mary E; Chibnik, Lori B; Wolf, Myles; Kay, Jonathan

2014-09-01

Nephrogenic systemic fibrosis (NSF) is an iatrogenic fibrosing disorder that primarily affects individuals with chronic kidney disease (CKD) following exposure to gadolinium-based contrast agents (GBCAs). Derangements of calcium and phosphorus have been reported in patients with NSF. The aim of this study was to investigate potential factors in addition to GBCA exposure that may be involved in the pathogenesis of NSF. We hypothesized that patients with stage 5 CKD and NSF would manifest greater alterations in calcium, phosphorus and fibroblast growth factor 23 (FGF23) levels than those who do not have NSF. Levels of phosphorus, calcium, FGF23 and 25-hydroxy-vitamin D were measured in 10 patients with stage 5 CKD and biopsy-proven NSF and in 19 patients with stage 5 CKD without NSF. Statistical analyses were performed using Fisher's exact test for categorical variables and the Kruskal-Wallis test for continuous variables. Patients with NSF had significantly lower phosphorus levels compared with controls (P = 0.01). There were no significant differences between NSF patients and controls in calcium, 25-hydroxy-vitamin D, intact parathyroid hormone or FGF23 levels. Differences in phosphorus metabolism may exist between patients with stage 5 CKD and NSF compared with patients with stage 5 CKD without NSF. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Prophylactic oral calcium supplementation therapy to prevent early post thyroidectomy hypocalcemia and evaluation of postoperative parathyroid hormone levels to detect hypocalcemia: A prospective randomized study.

PubMed

Arer, Ilker Murat; Kus, Murat; Akkapulu, Nezih; Aytac, Huseyin Ozgur; Yabanoglu, Hakan; Caliskan, Kenan; Tarim, Mehmet Akin

2017-02-01

Postoperative hypocalcemia is the most common complication after total thyroidectomy. Postoperative parathyroid hormone (PTH) measurement is one of the methods to detect or prevent postoperative hypocalcemia. Prophylactic oral calcium supplementation is another method to prevent early postoperative hypocalcemia. The aim of this study is to detect the accurate timing of PTH and evaluate efficacy of routine oral calcium supplementation for postoperative hypocalcemia. A total of 106 patients were performed total thyroidectomy. Rotuine oral calcium supplementation was given to group 1 and no treatment to group 2 according to randomization. Serum calcium and PTH level of patients in group 2 at postoperative 6, 12 and 24 h and patients in both groups at postoperative day 7 were evaluated. Patients were compared according to age, sex, operation findings, serum calcium and PTH levels and symptomatic hypocalcemia. Half of the patients (50%) were in group 1. Most of the patients were female (83%). The most common etiology of thyroid disease was multinodular goiter (64.1%). Oral calcium supplementation was given to 18 (33.9%) patients in group 2. Symptomatic hypocalcemia for group 1 and 2 was found to be 1.9 and 33.9% respectively (p < 0.05). No statistical difference can be observed regarding the timing of serum biomarkers. Serum PTH levels at postoperative 12 and 24 h can predict early post-thyroidectomy hypocalcemia. Prophylactic oral calcium supplementation therapy can prevent early post-thyroidectomy hypocalcemia with advantages of being cost effective and safe. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Pharmacological postconditioning with atorvastatin calcium attenuates myocardial ischemia/reperfusion injury in diabetic rats by phosphorylating GSK3β.

PubMed

Chen, Linyan; Cai, Ping; Cheng, Zhendong; Zhang, Zaibao; Fang, Jun

2017-07-01

Diabetes is an independent risk factor for myocardial ischemia, and many epidemiological data and laboratory studies have revealed that diabetes significantly exacerbated myocardial ischemia/reperfusion injury and ameliorated protective effects. The present study aimed to determine whether pharmacological postconditioning with atorvastatin calcium lessened diabetic myocardial ischemia/reperfusion injury, and investigated the role of glycogen synthase kinase (GSK3β) in this. A total of 72 streptozotocin-induced diabetic rats were randomly divided into six groups, and 24 age-matched male non-diabetic Sprague-Dawley rats were randomly divided into two groups. Rats all received 40 min myocardial ischemia followed by 180 min reperfusion, except sham-operated groups. Compared with the non-diabetic ischemia/reperfusion model group, the diabetic ischemia/reperfusion group had a comparable myocardial infarct size, but a higher level of serum cardiac troponin I (cTnI) and morphological alterations to their myocardial cells. Compared with the diabetic ischemia/reperfusion group, the group that received pharmacological postconditioning with atorvastatin calcium had smaller myocardial infarct sizes, lower levels of cTnI, reduced morphological alterations to myocardial cells, higher levels of p-GSK3β, heat shock factor (HSF)-1 and heat shock protein (HSP)70. The cardioprotective effect conferred by atorvastatin calcium did not attenuate myocardial ischemia/reperfusion injury following application of TDZD-8, which phosphorylates and inactivates GSK3β. Pharmacological postconditioning with atorvastatin calcium may attenuate diabetic heart ischemia/reperfusion injury in the current context. The phosphorylation of GSK3β serves a critical role during the cardioprotection in diabetic rats, and p-GSK3β may accelerate HSP70 production partially by activating HSF-1 during myocardial ischemic/reperfusion injury.

Strong Negative Interference by Calcium Dobesilate in Sarcosine Oxidase Assays for Serum Creatinine Involving the Trinder Reaction

PubMed Central

Guo, Xiuzhi; Hou, Li’an; Cheng, Xinqi; Zhang, Tianjiao; Yu, Songlin; Fang, Huiling; Xia, Liangyu; Qi, Zhihong; Qin, Xuzhen; Zhang, Lin; Liu, Qian; Liu, Li; Chi, Shuling; Hao, Yingying; Qiu, Ling

2015-01-01

Abstract The vasoprotective drug calcium dobesilate is known to interfere with creatinine (Cr) quantifications in sarcosine oxidase enzymatic (SOE) assays. The aim of this study was to investigate this interference in 8 different commercially available assays and to determine its clinical significance. In in vitro experiments, interference was evaluated at 3 Cr levels. For this, Cr was quantified by SOE assays in pooled serum supplemented with calcium dobesilate at final concentrations of 0, 2, 4, 8, 16, 32, and 64 μg/mL. Percent bias was calculated relative to the drug-free specimen. For in vivo analyses, changes in serum concentrations of Cr, cystatin C (CysC; a renal function marker), and calcium dobesilate were monitored in healthy participants of group I before and after oral calcium dobesilate administration. In addition, variations in interference were also examined among different SOE assays using serum obtained from healthy participants of group II. Lastly, Cr levels from the 10 patients treated with calcium dobesilate were measured using 4 SOE assays and liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) for comparison. Our in vitro analyses indicated that the presence of 8 μg/mL calcium dobesilate resulted in a −4.4% to −36.3% reduction in Cr serum concentration compared to drug-free serum for 8 SOE assays examined. In vivo, Cr values decreased relative to the baseline level with increasing drug concentration, with the lowest Cr levels obtained at 2 or 3 hours after drug administration in participants of group I. The observed Cr concentrations for participants in group II were reduced by −28.5% to −3.1% and −60.5% to −11.6% at 0 and 2 hours after administration related to baseline levels. The Cr values of 10 patients measured by Roche, Beckman, Maker, and Merit Choice SOE assays showed an average deviation of −20.0%, −22.4%, −14.2%, and −29.6%, respectively, compared to values obtained by LC-IDMS/MS. These results revealed a clinically significant negative interference with calcium dobesilate in all sarcosine oxidase-based Cr assays, but the degree of interference varied greatly among the assays examined. Thus, extra care should be taken in evaluating Cr quantification obtained by SOE assays in patients undergoing calcium dobesilate therapy. PMID:26061311

[Role of parathyroid hormone measurement in prediction for symptomatic hypocalcaemia after total thyroidectomy].

PubMed

An, Chang-ming; Tang, Ping-zhang; Xu, Zhen-gang; Zhang, Bin; Zhang, Zong-min; Yan, Dan-gui; Li, Zheng-jiang

2010-03-01

To evaluate the role of parathyroid hormone (PTH) and serum calcium in prediction for hypocalcaemia after total thyroidectomy. One hundred and sixty-five patients undergoing total or complete total thyroidectomy were reviewed retrospectively. The indications included bilateral carcinoma, undifferential carcinoma, surroundings invasion, distant metastasis and huge benign lesions. Preoperative and postoperative PTH, calcium concentrations and their decline levels were compared between Jan. 2005 and May 2009. The role of PTH value and decline level predicting for symptomatic hypocalcaemia were analyzed by receiver operator characteristics (ROC) curve. After total thyroidectomy, 85 patients (51.5%) developed hypocalcemia. Symptoms were reported by 36 patients (21.8%). The mean concentration of PTH for normocalcaemia (80 cases), asymptomatic hypocalcaemia (49 cases) and symptomatic patients (36 cases) were 31.0 ng/L, 19.6 ng/L and 11.9 ng/L, respectively. The mean decline level for the three groups were 28.6%, 52.6% and 78.0%, respectively. PTH value and its decline level had a poor predicting value for symptomatic hypocalcaemia and high negative predicting value for asymptomatic patients. The serum calcium concentration more than 2.0 mmol/L, PTH level higher than 15 ng/L and PTH decline less than 50% had the good negative predicting value of 97.6%, 90.3% and 96.5%, respectively. Postoperative PTH and its decline level were significantly correlated with postoperative serum calcium concentration but had a low accuracy for predicting symptomatic hypocalcaemia. The serum calcium concentration more than 2.0 mmol/L, PTH level higher than 15 ng/L and PTH decline less than 50% had the good predicting value for asymptomatic patients. Calcium should be routinely supplemented in the first 24 h after total thyroidectomy to reduce the rate of hypocalcemia and the severity of hypocalcemia symptoms.

Sevelamer is cost-saving vs. calcium carbonate in non-dialysis-dependent CKD patients in italy: a patient-level cost-effectiveness analysis of the INDEPENDENT study.

PubMed

Ruggeri, Matteo; Cipriani, Filippo; Bellasi, Antonio; Russo, Domenico; Di Iorio, Biagio

2014-01-01

To conduct a cost-effectiveness analysis of sevelamer versus calcium carbonate in patients with non-dialysis-dependent CKD (NDD-CKD) from the Italian NHS perspective using patient-level data from the INDEPENDENT-CKD study. Patient-level data on all-cause mortality, dialysis inception and phosphate binder dose were obtained for all 107 sevelamer and 105 calcium carbonate patients from the INDEPENDENT-CKD study. Hospitalization and frequency of dialysis data were collected post hoc for all patients via a retrospective chart review. Phosphate binder, hospitalization, and dialysis costs were expressed in 2012 euros using hospital pharmacy, Italian diagnosis-related group and ambulatory tariffs, respectively. Total life years (LYs) and costs per treatment group were calculated for the 3-year period of the study. Bootstrapping was used to estimate confidence intervals around outcomes, costs, and cost-effectiveness and to calculate the cost-effectiveness acceptability curve. A subgroup analysis of patients who did not initiate dialysis during the INDEPENDENT-CKD study was also conducted. Sevelamer was associated with 0.06 additional LYs (95% CI -0.04 to 0.16) and cost savings of EUR -5,615 (95% CI -10,066 to -1,164) per patient compared with calcium carbonate. On the basis of the bootstrap analysis, sevelamer was dominant compared to calcium carbonate in 87.1% of 10,000 bootstrap replicates. Similar results were observed in the subgroup analysis. RESULTS were driven by a significant reduction in all-cause mortality and significantly fewer hospitalizations in the sevelamer group, which offset the higher acquisition cost for sevelamer. Sevelamer provides more LYs and is less costly than calcium carbonate in patients with NDD-CKD in Italy.

Bone Is a Major Target of PTH/PTHrP Receptor Signaling in Regulation of Fetal Blood Calcium Homeostasis

PubMed Central

Hirai, Takao; Kobayashi, Tatsuya; Nishimori, Shigeki; Karaplis, Andrew C.; Goltzman, David

2015-01-01

The blood calcium concentration during fetal life is tightly regulated within a narrow range by highly interactive homeostatic mechanisms that include transport of calcium across the placenta and fluxes in and out of bone; the mechanisms of this regulation are poorly understood. Our findings that endochondral bone-specific PTH/PTHrP receptor (PPR) knockout (KO) mice showed significant reduction of fetal blood calcium concentration compared with that of control littermates at embryonic day 18.5 led us to focus on bone as a possibly major determinant of fetal calcium homeostasis. We found that the fetal calcium concentration of Runx2 KO mice was significantly higher than that of control littermates, suggesting that calcium flux into bone had a considerable influence on the circulating calcium concentration. Moreover, Runx2:PTH double mutant fetuses showed calcium levels similar to those of Runx2 KO mice, suggesting that part of the fetal hypocalcemia in PTH KO mice was caused by the increment of the mineralized bone mass allowed by the formation of osteoblasts. Finally, Rank:PTH double mutant mice had a blood calcium concentration even lower than that of the either Rank KO or PTH KO mice alone at embryonic day 18.5. These observations in our genetic models suggest that PTH/PTHrP receptor signaling in bones has a significant role of the regulation of fetal blood calcium concentration and that both placental transport and osteoclast activation contribute to PTH's hypercalcemic action. They also show that PTH-independent deposition of calcium in bone is the major controller of fetal blood calcium level. PMID:26052897

The Effects of Vitamin D-K-Calcium Co-Supplementation on Endocrine, Inflammation, and Oxidative Stress Biomarkers in Vitamin D-Deficient Women with Polycystic Ovary Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial.

PubMed

Razavi, M; Jamilian, M; Karamali, M; Bahmani, F; Aghadavod, E; Asemi, Z

2016-07-01

The current study was conducted to assess the effects of vitamin D-K-calcium co-supplementation on endocrine, inflammation, and oxidative stress biomarkers in vitamin D-deficient women with polycystic ovary syndrome (PCOS). This randomized double-blind, placebo-controlled trial was performed on 60 vitamin D-deficient women diagnosed with PCOS aged 18-40 years old. Participants were randomly allocated into 2 groups to intake either 200 IU vitamin D, 90 μg vitamin K plus, 500 mg calcium supplements (n=30), or placebo (n=30) twice a day for 8 weeks. Endocrine, inflammation, and oxidative stress biomarkers were quantified at the beginning and the end of the study. After 8 weeks of intervention, compared with the placebo, vitamin D-K-calcium co-supplementation resulted in a significant reduction in serum-free testosterone (- 2.1±1.6 vs.+0.1±1.0 pg/ml, p<0.001) and dehydroepiandrosterone sulfate (DHEAS) levels (- 0.8±1.0 vs.-0.1±0.5 μg/ml, p=0.006). In addition, a significant increase in plasma total antioxidant capacity (TAC) (+ 75.7±126.1 vs.-80.4±242.8 mmol/l, p=0.005) and a significant difference in plasma malondialdehyde (MDA) concentrations (+ 0.03±0.6 vs.+1.4±2.4 μmol/l, p=0.005) was observed following the supplementation with vitamin D-K-calcium compared with the placebo. A trend toward a greater decrease in luteinizing hormone was observed in vitamin D-K-calcium co-supplement group compared to placebo group (- 7.0 vs.-1.2 IU/l, p=0.09). We did not find any significant effect of vitamin D-K-calcium co-supplementation on prolactin, follicle-stimulating hormone, 17-OH progesterone, inflammatory markers, and glutathione levels. Overall, vitamin D-K-calcium co-supplementation for 8 weeks among vitamin D-deficient women with PCOS had beneficial effects on serum DHEAS, free testosterone, plasma TAC, and MDA levels. © Georg Thieme Verlag KG Stuttgart · New York.

Proton pump inhibitor use for 12 months is not associated with changes in serum magnesium levels: a prospective open label comparative study.

PubMed

Bahtiri, Elton; Islami, Hilmi; Hoxha, Rexhep; Gashi, Afrim; Thaçi, Kujtim; Karakulak, Çağla; Thaçi, Shpetim; Qorraj Bytyqi, Hasime

2017-03-01

Proton pump inhibitors (PPIs) are a widely used class of drugs because of a generally acceptable safety profile. Among recently raised safety issues of the long-term use of PPIs is the increased risk of developing hypomagnesemia. As there have been very few prospective studies measuring serum magnesium levels before and after PPI therapy, we aimed to prospectively assess the potential association between PPI therapy for 12 months and the risk of hypomagnesemia as well as the incidence of new-onset hypomagnesemia during the study. In addition, the association of PPI therapy with the risk of hypocalcemia was assessed. The study included 250 patients with normal serum magnesium and total calcium levels, who underwent a long-term PPI treatment. Serum magnesium, total calcium, and parathormone (PTH) levels were measured at baseline and after 12 months. Of the 250 study participants, 209 completed 12 months of treatment and were included in the statistical analysis. The Wilcoxon signed rank test showed no statistically significant differences in serum magnesium levels between measurements at two different time points. However, there were statistically significant differences in serum total calcium and PTH levels in PPI users. Stable serum magnesium levels were demonstrated after 12 months and no association between PPI use and risk of hypomagnesemia was shown in the general population. Significant reductions of serum total calcium levels were demonstrated among PPI users; nevertheless, further research is required before recommending any serum calcium and PTH level monitoring in patients initiated on long-term PPI therapy.

Differential effects of the steaming time and frequency for manufactured red Liriope platyphylla on nerve growth factor secretion ability, nerve growth factor receptor signaling pathway and regulation of calcium concentration.

PubMed

Choi, Sun Il; Goo, Jun Seo; Kim, Ji Eun; Nam, So Hee; Hwang, In Sik; Lee, Hye Ryun; Lee, Young Ju; Son, Hong Joo; Lee, Hee Seob; Lee, Jong Sup; Kim, Hak Jin; Hwang, Dae Youn

2012-11-01

The herb Liriope platyphylla (LP) has been considered to have curative properties for diabetes, asthma and neurodegenerative disorders. To examine the effects of steaming time and frequency of manufactured red LP (RLP) on the nerve growth factor (NGF) secretion ability and NGF receptor signaling pathway, the NGF concentration, cell differentiation, NGF signaling pathway and calcium concentration were analyzed in neuronal cells treated with several types of LPs manufactured under different conditions. The maximum NGF secretion was observed in B35 cells treated with 50 µg/ml LP extract steamed for 9 h (9-SLP) and with two repeated steps (3 h steaming and 24 h air-dried) carried out 7 times (7-SALP). No significant changes in viability were detected in any of the cells treated with the various LPs, with the exception of 0-SLP and 0-SALP. In addition, PC12 cell differentiation was induced by treatment with the NGF-containing conditional medium (CM) collected from the RLP-treated cells. The levels of TrkA and extracellular signal-regulated kinase (ERK) phosphorylation in the high affinity NGF receptor signaling pathway were significantly higher in the cells treated with 3-SLP or 1-SALP/3-SALP CM compared with those treated with the vehicle CM. In the low affinity NGF receptor pathway, the expression levels of most components were higher in the 9-, 15- and 24-SALP CM-treated cells compared with the vehicle CM-treated cells. However, this level was significantly altered in cells treated with 3-SALP CM. Furthermore, an examination of the RLP function on calcium regulation revealed that only the LP- or RLP-treated cells exhibited changes in intracellular and extracellular calcium levels. RLP induced a significant decrease in the intracellular calcium levels and an increase in the extracellular calcium levels. These results suggest the possibility that steaming-processed LP may aid in the relief of neurodegenerative diseases through the NGF secretion ability and NGF signaling pathway.

Vitamin C-lipid metabolites: uptake and retention and effect on plasma C-reactive protein and oxidized LDL levels in healthy volunteers.

PubMed

Pancorbo, Dario; Vazquez, Carlos; Fletcher, Mary Ann

2008-11-01

Previously, a novel formulation of vitamin C-lipid metabolites (PureWay-C) was shown to be more rapidly taken-up by human T-lymphocytes and more rapidly stimulate neurite outgrowth, fibroblast adhesion and inhibition of xenobiotic-induced T-cell hyperactivation. Here, PureWay-C serum levels were measured in healthy volunteers after oral supplementation. Plasma C-reactive protein and oxidized low density lipoprotein levels (LDL) were also measured. Healthy volunteers maintained a low vitamin C diet for 14 days and, following an overnight fast, received a single oral dose of (vitamin C) 1000 mg of either ascorbic acid (AA), calcium ascorbate (CaA), vitamin C-lipid metabolites (PureWay-C), or calcium ascorbate-calcium threonate-dehydroascorbate (Ester-C). Blood samples were collected immediately prior to the oral dose administration and at various times post ingestion. Twenty-four-hour urine collections were saved for oxalate and uric acid assays. PureWay-C supplementation leads to the highest absolute serum vitamin C levels when compared to AA, CaA and Ester-C. PureWay-C provides a statistically significant greater serum level than calcium ascorbate at 1, 2, 4, and 6 hours post oral supplementation whereas Ester-C shows a less but slightly statistically significant increase at only 1 and 4 hours. Oral supplementation with PureWay-C also led to a greater reduction in plasma C-reactive protein and oxidized LDL levels compared to the other vitamin C formulations. PureWay-C is more rapidly absorbed and leads to higher serum vitamin C levels and greater reduction of plasma levels of inflammatory and oxidative stress markers than other forms of vitamin C, including Ester-C.

Parvalbumin overexpression alters immune-mediated increases in intracellular calcium, and delays disease onset in a transgenic model of familial amyotrophic lateral sclerosis

NASA Technical Reports Server (NTRS)

Beers, D. R.; Ho, B. K.; Siklos, L.; Alexianu, M. E.; Mosier, D. R.; Mohamed, A. H.; Otsuka, Y.; Kozovska, M. E.; McAlhany, R. E.; Smith, R. G.;

Effects of dietary carbohydrates on metabolism of calcium and other minerals in normal subjects and patients with noninsulin-dependent diabetes mellitus.

PubMed

Garg, A; Bonanome, A; Grundy, S M; Unger, R H; Breslau, N A; Pak, C Y

1990-04-01

Transient hypercalciuria has been noted after high carbohydrate meals which is independent of dietary calcium and is probably due to impaired renal calcium reabsorption mediated by an increase in plasma insulin levels. Based on these observations, some investigators believe that long term intake of high carbohydrate diets may increase the risk of nephrolithiasis and possibly osteoporosis. Using a randomized cross-over design, we compared high carbohydrate diets (60% carbohydrate and 25% fat) with high fat diets (50% fat and 35% carbohydrate) for effects on metabolism of calcium and other minerals in eight normal subjects and eight euglycemic patients with noninsulin-dependent diabetes mellitus. All other dietary constituents, such as protein, fiber, fluid, minerals (including Ca, Mg, Na, K, and P), and caffeine intake, were kept constant. Despite higher daylong levels of plasma insulin on the high carbohydrate diets compared to the high fat diet in both normal and noninsulin-dependent diabetic subjects, no changes in daily urinary excretion of calcium or other constituents, associated with renal stone risk, were observed. Furthermore, there was no change in fractional intestinal 47Ca absorption. Although hypercalciuria may ensue transiently after high carbohydrate meals, we conclude that substitution of simple or complex carbohydrates for fats in an isocaloric manner for a longer duration does not result in significant urinary calcium loss, and therefore, high intakes of digestible carbohydrates may not increase the risk of nephrolithiasis or osteoporosis via this mechanism.

Management of nutritional rickets in Indian children: a randomized controlled trial.

PubMed

Aggarwal, Varun; Seth, Anju; Marwaha, Raman K; Sharma, Bhavna; Sonkar, Pitamber; Singh, Satveer; Aneja, Satinder

2013-04-01

Rickets is usually attributed to vitamin D deficiency. However, recent studies have implicated dietary calcium deficiency in its etiology. Information on relative efficacy of calcium, vitamin D or both together in healing of rickets is limited. To study effect of treatment with calcium, vitamin D or a combination of these two on healing of nutritional rickets in young children. Randomized controlled trial. Sixty-seven cases of nutritional rickets in the age group of 6 months to 5 years were randomly allocated to receive vitamin D (600 000 IU single intramuscular dose), calcium (75 mg/kg/day elemental calcium orally) or a combination of the above two for a period of 12 weeks. The demographic parameters, nutritional status, dietary calcium and phytate intake were assessed for all. Radiographs (wrist and knee) and biochemical parameters (serum calcium, inorganic phosphate, alkaline phosphatase, 25-hydroxycholecalciferol and parathyroid hormone) were evaluated at baseline, 6 and 12 weeks for evidence of healing. Mean dietary intake of calcium in all cases was low (204 ± 129 mg/day). Mean serum 25-hydroxycholecalciferol D level was 15.9 ± 12.4 ng/ml, and 82.1% of patients had serum vitamin D levels <20 ng/ml, indicative of vitamin D deficiency. After 6 and 12 weeks of treatment, radiological and biochemical evidence of healing rickets was observed in all treatment groups, albeit to a variable extent. The combined end point of normal serum alkaline phosphatase and complete radiological healing at 12 weeks was observed in 50% subjects on combination therapy as compared with 15.7% subjects on vitamin D alone and 11.7% on calcium alone. Children with rickets had a low serum vitamin D level and a low dietary calcium intake. The best therapeutic response was seen with a combination of vitamin D and calcium than either of them given alone. CTRI/2010/091/000448.

Calcium and Vitamin D Supplementation and Cognitive Impairment in the Women’s Health Initiative

PubMed Central

Rossom, Rebecca C.; Espeland, Mark A.; Manson, JoAnn E.; Dysken, Maurice W.; Johnson, Karen C.; Lane, Dorothy S.; LeBlanc, Erin S.; Lederle, Frank A.; Masaki, Kamal H.; Margolis, Karen L.

2012-01-01

Background Calcium and vitamin D are thought to play important roles in neuronal functioning. Studies have found associations between low serum vitamin D levels and reduced cognitive functioning, as well as high serum calcium levels and reduced cognitive functioning. Objectives To examine the effects of vitamin D and calcium on cognitive outcomes in elderly women. Design Post-hoc analysis of a randomized double-blinded placebo-controlled trial. Setting 40 Women’s Health Initiative clinical centers across the U.S. Participants 4143 women aged 65 years and older without probable dementia at baseline who participated in the WHI Calcium and Vitamin D trial and the Women’s Health Initiative Memory Study. Interventions 2034 women were randomized to 1000 mg of calcium carbonate combined with 400 IU of vitamin D3; 2109 women were randomized to placebo. Measurements Primary: classifications of probable dementia or mild cognitive impairment via a 4-phase protocol that included central adjudication. Secondary: global cognitive function and individual cognitive subtests. Results Mean age of participants was 71 years. During mean follow-up of 7.8 years, there were 39 cases of incident dementia among calcium plus vitamin D subjects compared to 37 cases among placebo subjects (hazard ratio=1.11, 95% CI: 0.71–1.74, p=0.64). Likewise, there were 98 cases of incident mild cognitive impairment among calcium plus vitamin D subjects compared to 108 cases among placebo subjects (hazard ratio=0.95, 95% CI: 0.72–1.25, p=0.72). There were no significant differences in incident dementia or mild cognitive impairment, or in global or domain-specific cognitive function between groups. Conclusion There was no association between treatment assignment and incident cognitive impairment. Further studies are needed to investigate the effects of vitamin D and calcium separately, on men and in other age and ethnic groups, and with other doses. PMID:23176129

Hypochlorhydria-induced calcium malabsorption does not affect fracture healing but increases post-traumatic bone loss in the intact skeleton.

PubMed

Haffner-Luntzer, Melanie; Heilmann, Aline; Heidler, Verena; Liedert, Astrid; Schinke, Thorsten; Amling, Michael; Yorgan, Timur Alexander; Vom Scheidt, Annika; Ignatius, Anita

2016-11-01

Efficient calcium absorption is essential for skeletal health. Patients with impaired gastric acidification display low bone mass and increased fracture risk because calcium absorption is dependent on gastric pH. We investigated fracture healing and post-traumatic bone turnover in mice deficient in Cckbr, encoding a gastrin receptor that affects acid secretion by parietal cells. Cckbr-/- mice display hypochlorhydria, calcium malabsorption, and osteopenia. Cckbr-/- and wildtype (WT) mice received a femur osteotomy and were fed either a standard or calcium-enriched diet. Healed and intact bones were assessed by biomechanical testing, histomorphometry, micro-computed tomography, and quantitative backscattering. Parathyroid hormone (PTH) serum levels were determined by enzyme-linked immunosorbent assay. Fracture healing was unaffected in Cckbr-/- mice. However, Cckbr-/- mice displayed increased calcium mobilization from the intact skeleton during bone healing, confirmed by significantly elevated PTH levels and osteoclast numbers compared to WT mice. Calcium supplementation significantly reduced secondary hyperparathyroidism and bone resorption in the intact skeleton in both genotypes, but more efficiently in WT mice. Furthermore, calcium administration improved bone healing in WT mice, indicated by significantly increased mechanical properties and bone mineral density of the fracture callus, whereas it had no significant effect in Cckbr-/- mice. Therefore, under conditions of hypochlorhydria-induced calcium malabsorption, calcium, which is essential for callus mineralization, appears to be increasingly mobilized from the intact skeleton in favor of fracture healing. Calcium supplementation during fracture healing prevented systemic calcium mobilization, thereby maintaining bone mass and improving fracture healing in healthy individuals whereas the effect was limited by gastric hypochlorhydria. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1914-1921, 2016. © 2016 The Authors. Journal of Orthopaedic Research Published by by Wiley Periodicals, Inc.

Calcium intake in the United States from dietary and supplemental sources across adult age groups: new estimates from the National Health and Nutrition Examination Survey 2003-2006.

PubMed

Mangano, Kelsey M; Walsh, Stephen J; Insogna, Karl L; Kenny, Anne M; Kerstetter, Jane E

2011-05-01

Adequate lifelong calcium intake is essential in optimizing bone health. Recent National Health and Nutrition Examination Survey data were used to quantify variation in calcium intake across adult age groups and to relate age-associated changes in calcium intake with energy intake. Additional goals were to assess differences in dietary calcium intake between supplemental calcium users and nonusers and to evaluate associations between age and calcium density in the diet. This cross-sectional analysis determined calcium and energy intake for National Health and Nutrition Examination Survey respondents during 2003-2006. Diet was assessed with 24-hour recall and supplement use via questionnaire. Trends in median intakes for dietary calcium, total calcium, and energy across age categories were assessed using survey analysis methods. Nutrient density was represented using calcium to energy intake ratios. The analyses included data from 9,475 adults. When compared to the 19- to 30-year age group, median dietary calcium intake was lower in the ≥81-year age group by 23% in men (P<0.001) and by 14% in women (P=0.003). These reductions coincided with 35% and 28% decreases, respectively, in median energy intake (P<0.001 for each sex). In contrast, the frequency of calcium supplement use increased (P<0.001) with age in both men and women. Yet, among female supplement users, the decline in median dietary calcium intake was greater than in nonusers (P=0.02). Calcium density in the diet significantly increased relative to age in men and women (P<0.001 for each sex); however, dietary and total calcium to energy ratios were insufficient to meet target ratios inferred by adequate intake standards after age 50 years. Although supplemental calcium use and calcium density were highest in older age groups, they were not sufficient in meeting recommended levels. New approaches to increasing the frequency and level of calcium supplement use to enhance calcium density in diets may be necessary to reduce osteoporosis risk among older Americans. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

Effect of hydrocortisone on total body calcium in rats. [/sup 47/Ca and /sup 85/Sr tracer techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yasumura, S.; Ellis, K.J.; Cohn, S.H.

Administration of 5 mg. of hydrocortisone acetate to rats every other day for 2 weeks resulted in growth retardation and weight loss as indicated by body weights of experimental animals, which averaged 33 percent lower than those of the controls, and a significant decrease in the length of the tibiae and femurs (p less than 0.01 for treated vs controls). However, despite the smaller size of the treated animals, the values for total body calcium (TBCa) and the calcium in the tibia and femur did not differ significantly from control values. Thus, there was more calcium per unit length ofmore » bone, resulting in an increase in the skeletal density of treated rats. This finding was confirmed by x-ray examination of these bones. The net intestinal absorption of calcium (rate of initial entry) calculated from plasma levels following an oral and intravenous dose of /sup 47/Ca and /sup 85/Sr, respectively, was not significantly different in hydrocortisone-treated rats compared to controls. This would indicate that the rate of intestinal absorption of calcium is unimpaired despite the administration of massive doses of corticosteroids. When the animals were placed on a calcium-deficient diet, both TBCa and tibia and femur calcium levels were decreased. Subsequent administration of hydrocortisone did not alter the calcium values. The results of this study are compatible with the hypothesis that hydrocortisone promotes weight loss, retards growth, but inhibits the rate of bone resorption.« less

Calcium ketoglutarate versus calcium acetate for treatment of hyperphosphataemia in patients on maintenance haemodialysis: a cross-over study.

PubMed

Birck, R; Zimmermann, E; Wassmer, S; Nowack, R; van der Woude, F J

1999-06-01

Since dietary restrictions and phosphorus removal by haemodialysis (HD) are not sufficient to control serum phosphate (s-phosphate) levels in dialysis patients the use of oral phosphate binders is mandatory. Calcium ketoglutarate (CaKE) is an analogue of glutamic acid exerting phosphate binding properties. Therefore we compared this substance to calcium acetate (CaAC) in a 24-weeks open cross-over trial in 28 maintenance HD patients. Medications and HD prescriptions were kept unchanged during the trial. Following 2 weeks of withdrawal of phosphate binders, patients were randomly assigned to one of the calcium salts for 12 weeks; after a second withdrawal of 2 weeks, all patients were shifted to the other treatment for another 12 weeks. All patients received equimolar doses of CaKE and CaAC with respect to the amount of prescribed elemental calcium. Treatment with CaAC and CaKE significantly reduced s-phosphate levels after 4 weeks (CaAC 1.95+/-0.6 vs. 2.4+/-0.53 mmol/l, P = 0.004; CaKE 1.95+/-0.4 vs. 2.47+/-0.63 mmol/l, P = 0.0001) reaching a virtually stable plateau over the remaining observation time without significant differences between the groups. The incidence of hypercalcaemia defined as a serum calcium level > or =2.8 mmol/l was significantly higher in CaAC than in CaKE treated patients (n = 8 vs. n = 1, P = 0.03). There were no significant differences in serum intact parathyroid hormone (PTH) bicarbonate, albumin or calcitriol levels between the groups after 12 weeks treatment. We conclude that CaKE is as effective as CaAC for treatment of hyperphosphataemia in chronic HD patients and may be particularly helpful in patients who are prone to develop hypercalcaemia.

Decrease in T Cell Activation and Calcium Flux during Clinorotation

NASA Technical Reports Server (NTRS)

Sams, Clarence; Holtzclaw, J. David

2006-01-01

We investigated the effect of altered gravitational environments on T cell activation. We isolated human, naive T cells (CD3+CD14-CD19-CD16-CD56-CD25-CD69-CD45RA-) following IRB approved protocols. These purified T cells were then incubated with 6 mm polystyrene beads coated with OKT3 (Ortho Biotech, Raritan, NJ) and antiCD28 (Becton Dickinson (BD), San Jose, CA) at 37 C for 24 hours. Antibodies were at a 1:1 ratio and the bead-to-cell ratio was 2:1. Four incubation conditions existed: 1) static or "1g"; 2) centrifugation at 10 relative centrifugal force (RCF) or "10g"; 3) clinorotation at 25 RPM (functional weightlessness or "0g"); and 4) clinorotation at 80 RPM ("1g" plus net shear force approx.30 dynes/sq cm). Following incubation, T cells were stained for CD25 expression (BD) and intracellular calcium (ratio of Fluo4 to Fura Red, Molecular Probes, Eugene, OR) and analyzed by flow cytometry (Coulter EPICS XL, Miami, FL). Results: Static or "1g" T cells had the highest level of CD25 expression and intracellular calcium. T cells centrifuged at 10 RCF ("10g") had lower CD25 expression and calcium levels compared to the static control. However, cells centrifuged at 10 RCF had higher CD25 expression and calcium levels than those exposed to 24 RPM clinorotation ("0g"). T cells exposed to 24 RPM clinorotation had lower CD25 expression, but the approximately the same calcium levels than T cells exposed to 80 RPM clinorotation. These data suggest that stress-activated calcium channel exist in T cells and may play a role during T cell activation.

Teriparatide Therapy and Reduced Postoperative Hospitalization for Postsurgical Hypoparathyroidism.

PubMed

Shah, Meera; Bancos, Irina; Thompson, Geoffrey B; Richards, Melanie L; Kasperbauer, Jan L; Clarke, Bart L; Drake, Matthew T; Stan, Marius N

2015-09-01

Up to 20% of patients undergoing thyroidectomy develop hypocalcemia after surgery. Although usually transient, severe symptomatic hypocalcemia may occur. Teriparatide acetate (recombinant human parathyroid hormone 1-34) therapy can rapidly raise calcium levels. To test the hypothesis that teriparatide therapy in patients with postthyroidectomy hypoparathyroidism would expedite relief of symptomatic hypocalcemia and reduce the duration of hospitalization compared with standard treatment. Case series of all hospitalized patients 18 years or older treated with teriparatide for symptomatic postthyroidectomy hypocalcemia occurring immediately after thyroidectomy at Mayo Clinic, Rochester, Minnesota, between January 1, 2008, and June 30, 2014. A secondary analysis was performed with matched control and cohort groups having postthyroidectomy hypocalcemia of similar degree who received standard treatment only. Participants included 8 hospitalized patients who received teriparatide therapy after 24 hours of standard treatment (cases) and eight control patients selected from a cohort of 1193 thyroidectomies were matched for age, sex, body mass index, and nadir calcium levels. Teriparatide acetate therapy (20 µg twice daily) subcutaneously for 1 week, with the option of continuing at 20 µg/d for up to 3 weeks. Safety, symptom resolution, calcium supplementation, and duration of hospitalization. Among the 16 case and control patients the median nadir calcium level was 7.1 mg/dL in both groups. Most patients underwent thyroidectomy for thyroid cancer. Teriparatide therapy was safe, with no adverse events noted, and completely eliminated symptomatic hypocalcemia in all treated patients within 24 hours of initiation. Hospital discharge occurred at a median of 1.0 day (interquartile range, 1.0-1.0 day) after teriparatide therapy initiation among cases vs 2.5 days (interquartile range, 1.8-3.0 days) after the equivalent clinical point was reached in controls (P = .01). This value was 2.0 days in the source cohort (P = .02). On hospital discharge, patients had similar calcium levels. Six months after surgery, all patients treated with teriparatide showed partial or complete parathyroid recovery. Calcium supplementation and calcium levels were comparable between the groups. In this pilot study, teriparatide therapy in patients with postthyroidectomy hypoparathyroidism was safe, rapidly eliminated hypocalcemic symptoms, and likely reduced the duration of hospitalization. Given the limitations of this small study, a large-scale randomized trial is needed to verify these results and to assess the long-term effect of teriparatide therapy on clinical outcomes.

Phosphorus Balance in Adolescent Girls and the Effect of Supplemental Dietary Calcium.

PubMed

Vorland, Colby J; Martin, Berdine R; Weaver, Connie M; Peacock, Munro; Gallant, Kathleen M Hill

2018-03-01

There are limited data on phosphorus balance and the effect of dietary calcium supplements on phosphorus balance in adolescents. The purpose of this study was to determine phosphorus balance and the effect of increasing dietary calcium intake with a supplement on net phosphorus absorption and balance in healthy adolescent girls. This study utilized stored urine, fecal, and diet samples from a previously conducted study that focused on calcium balance. Eleven healthy girls ages 11 to 14 years participated in a randomized crossover study, which consisted of two 3-week periods of a controlled diet with low (817 ± 19.5 mg/d) or high (1418 ± 11.1 mg/d) calcium, separated by a 1-week washout period. Phosphorus intake was controlled at the same level during both placebo and calcium supplementation (1435 ± 23.5 and 1453 ± 28.0 mg/d, respectively, p = 0.611). Mean phosphorus balance was positive by about 200 mg/d and was unaffected by the calcium supplement ( p = 0.826). Urinary phosphorus excretion was lower with the calcium supplement (535 ± 42 versus 649 ± 41 mg/d, p = 0.013), but fecal phosphorus and net phosphorus absorption were not significantly different between placebo and calcium supplement (553 ± 60 versus 678 ± 63 versus mg/d, p = 0.143; 876 ± 62 versus 774 ± 64 mg/d, p = 0.231, respectively). Dietary phosphorus underestimates using a nutrient database compared with the content measured chemically from meal composites by ~40%. These results show that phosphorus balance is positive in girls during adolescent growth and that a calcium dietary supplement to near the current recommended level does not affect phosphorus balance when phosphorus intake is at 1400 mg/d, a typical US intake level. © 2017 American Society for Bone and Mineral Research.

Role of calcium deficiency in development of nutritional rickets in Indian children: a case control study.

PubMed

Aggarwal, Varun; Seth, Anju; Aneja, Satinder; Sharma, Bhawna; Sonkar, Pitamber; Singh, Satveer; Marwaha, Raman K

2012-10-01

Nutritional rickets is usually attributed to vitamin D deficiency. Studies from some tropical countries have postulated low dietary intake of calcium as the cause of nutritional rickets. Both vitamin D and dietary calcium deficiency are highly prevalent in India. Information on their relative contribution in the development of rickets in Indian children is limited. The aim was to study the role of calcium and vitamin D deficiency in causation of nutritional rickets in young Indian children. In a case-control study, 67 children with nutritional rickets and 68 age- and sex-matched healthy controls were compared for demographic factors, nutritional status, sun exposure (UV score), dietary calcium and phytate intake (for subjects not breast-fed at presentation), and biochemical parameters [serum calcium, inorganic phosphate, alkaline phosphatase, 25-hydroxyvitamin D (25OHD), and PTH]. Mean intake of calcium (204±129 vs. 453±234 mg/d; P<0.001) and proportion of calcium from dairy sources (41.7 vs. 88.6%; P<0.001) were significantly lower in cases vs. controls. The dietary intake of phytate was also significantly higher in cases (P=0.01). Median serum 25OHD level (interquartile range) in both cases and controls was in the range of deficiency [13.7 (10; 17.9) and 19.4 (12.3; 24.6) ng/ml, respectively]. There was no significant difference in the serum 25OHD level (P=0.08) or sun exposure as measured by UV score (P=0.39) among the cases and controls. In cases with rickets, significant negative correlations were seen between dietary calcium intake and radiological score (r=-0.28; P=0.03) and PTH (r=-0.26; P=0.02). No correlation was found between serum 25OHD level and radiological score or biochemical parameters of rickets. Rickets develops when low dietary calcium intake coexists with a low or borderline vitamin D nutrition status.

The impact of age and oral calcium and vitamin D supplements on postoperative hypocalcemia after total thyroidectomy. A prospective study

PubMed Central

2013-01-01

Background Hypocalcemia caused by transient or definitive hypoparathyroidism is the most frequent complication after total thyroidectomy (TT). We aimed to compare the impact of age and the clinical usefulness of oral calcium and vitamin D supplements on postoperative hypocalcemia after TT, and to determine which risk factors are important for hypocalcemia incidence. Methods Two hundred consecutive patients treated by TT were included prospectively in the present study. All patients supplemented oral calcium and vitamin D in the post-operative time. The data concerning symptomatic and laboratoristichypocalcemia were collected. Patients were evaluated according to age, sex, postoperative serum calcium levels, and preoperative serum alkaline phosphatasis levels. Results Symptomatic hypocalcemia developed only in 19 patients (9.5%), whereas laboratory hypocalcemia developed in 36 patients (18%). The risk for postoperative hypocalcemia was increate 20-fold for patients older than 50 years. Conclusions Age is significantly associated with postoperative hypocalcemia. Implementing oral calcium and vitamin D after total thyroidectomy can reduce the incidence of hypocalcemia related to surgery. PMID:24267491

The effect of purified compared with nonpurified diet on bone changes induced by hindlimb suspension of female rats

NASA Technical Reports Server (NTRS)

Tou, Janet C L.; Arnaud, Sara B.; Grindeland, Richard; Wade, Charles

2005-01-01

The purpose of this study was to compare the bone changes induced by unloading in rats fed different diets, because space flight studies use a semipurified diet, whereas space flight simulation studies typically use nonpurified diets. Female Sprague-Dawley rats were fed a purified American Institute of Nutrition (AIN) 93G diet or a standard nonpurified diet and kept ambulatory or subjected to unloading by hindlimb suspension (HLS) for 38 days. Bone mineral content (BMC), mechanical strength, and factors related to the diet that affect bone (i.e., urinary calcium excretion, estradiol, and corticosterone) were measured. Average food intakes (grams per day) differed for diets, but caloric intake (kilocalories per day) and the final body masses of treatment groups were similar. The HLS-induced decrease in femoral BMC was not statistically different for rats fed a nonpurified diet (-8.6%) compared with a purified AIN-93G diet (-11.4%). The HLS-induced decrease in femoral mechanical strength was not statistically different for rats fed a nonpurified diet (-24%) compared with a purified AIN-93G diet (-31%). However, bone lengths were decreased (P < 0.05) in rats fed a nonpurified diet compared with a purified diet. Plasma estradiol levels were lower (P < 0.05) in the HLS/AIN-93G group but similar in the HLS and ambulatory rats fed a nonpurified diet. Plasma estradiol was related to femoral BMC (r = 0.85, P < 0.01). Urinary calcium excretion was higher (P < 0.05) in rats fed a nonpurified diet than those fed a purified AIN-93G diet, which is consistent with the higher level of calcium in the nonpurified diet. Urinary corticosterone levels were higher (P < 0.05) in rats fed a nonpurified diet than rats fed the AIN-93G diet. Although the osteopenia induced by unloading was similar in both diet groups, there were differences in longitudinal bone growth, calcium excretion, plasma estradiol levels, and urinary corticosterone levels. Results indicate that the type of standard diet used is an important factor to consider when measuring bone end points.

Direct Inhibitory Effect of Hypercalcemia on Renal Actions of Parathyroid Hormone

PubMed Central

Beck, Nama; Singh, Harbans; Reed, Sarah W.; Davis, Bernard B.

1974-01-01

The effects of calcium on the renal actions of parathyroid hormone (PTH) were studied in vivo and in vitro. In parathyroidectomized rats, variable levels of blood calcium concentration were induced by intravenous infusion of calcium. The renal responses to the injected PTH, i.e. phosphate and cyclic AMP excretion, were compared in these animals. After PTH injection, the increases of both phosphate and cyclic AMP excretion were less in the calcium-infused animals than in the control group without calcium infusion. There was an inverse correlation between the renal responses to PTH and plasma calcium concentration of 4.2-13.5 mg/100 ml. But calcium had no effect on phosphate excretion induced by infusion of dibutyryl cyclic AMP. In the in vitro experiments, the increase of cyclic AMP concentration in response to PTH was less in renal cortical slices taken from the calcium-infused animals than in ones from the control group without calcium infusion. Calcium also inhibited the activation of renal cortical adenylate cyclase in response to PTH, but calcium had no effect on phosphodiesterase. The data indicate that calcium directly inhibits renal actions of PTH both in vivo and in vitro. Such inhibitory mechanism is probably at or before the step of PTH-dependent cyclic AMP generation in the kidney. PMID:4359938

Brassica villosa, a system for studying non-glandular trichomes and genes in the Brassicas.

PubMed

Nayidu, Naghabushana K; Tan, Yifang; Taheri, Ali; Li, Xiang; Bjorndahl, Trent C; Nowak, Jacek; Wishart, David S; Hegedus, Dwayne; Gruber, Margaret Y

2014-07-01

Brassica villosa is a wild Brassica C genome species with very dense trichome coverage and strong resistance to many insect pests of Brassica oilseeds and vegetables. Transcriptome analysis of hairy B. villosa leaves indicated higher expression of several important trichome initiation genes compared with glabrous B. napus leaves and consistent with the Arabidopsis model of trichome development. However, transcripts of the TRY inhibitory gene in hairy B. villosa were surprisingly high relative to B. napus and relative transcript levels of SAD2, EGL3, and several XIX genes were low, suggesting potential ancillary or less important trichome-related roles for these genes in Brassica species compared with Arabidopsis. Several antioxidant, calcium, non-calcium metal and secondary metabolite genes also showed differential expression between these two species. These coincided with accumulation of two alkaloid-like compounds, high levels of calcium, and other metals in B. villosa trichomes that are correlated with the known tolerance of B. villosa to high salt and the calcium-rich natural habitat of this wild species. This first time report on the isolation of large amounts of pure B. villosa trichomes, on trichome content, and on relative gene expression differences in an exceptionally hairy Brassica species compared with a glabrous species opens doors for the scientific community to understand trichome gene function in the Brassicas and highlights the potential of B. villosa as a trichome research platform.

Estimation and Comparison of Salivary Calcium, Phosphorous, Alkaline Phosphatase and pH Levels in Periodontal Health and Disease: A Cross-sectional Biochemical Study.

PubMed

Patel, Rufi Murad; Varma, Siddhartha; Suragimath, Girish; Zope, Sameer

2016-07-01

In oral diagnostics there is a great challenge to determine biomarkers for screening and evaluating the disease activity. Biomarkers can also serve as a useful tool to measure the efficacy of the therapy. To evaluate and compare the levels of salivary calcium, phosphorous, alkaline phosphatase and pH levels in periodontally healthy subjects and patients with gingivitis and periodontitis. The present study consisted of 150 subjects aged between 20-45 years who were divided into three groups; periodontally healthy, gingivitis and chronic periodontitis. Prior to the clinical examination the demographic details, relevant information of the subject, gingival index, plaque index, Oral Hygiene Index (OHI) and pH were recorded. Biochemical assay of saliva i.e., inorganic calcium, phosphorous and alkaline phosphatase were estimated by colorimetric method. ANOVA and Tukey's test were applied for statistical analysis. The mean levels of biomarkers studied were; inorganic calcium (12.55μg/dl), phosphorous (14.50μg/dl), alkaline phosphatase (49.62μg/dl) and pH (11.65). There was a gradual increase in these levels as the condition progressed from health to gingivitis or periodontitis which was statistically significant at p<0.001. Based on these results, it can be concluded that, the biomarkers like salivary calcium, phosphorous, alkaline phosphatase and pH can be considered for evaluating the diagnosis and prognosis of periodontal tissues in disease and health.

Elemental calcium intake associated with calcium acetate/calcium carbonate in the treatment of hyperphosphatemia

PubMed Central

Wilson, Rosamund J; Copley, J Brian

2017-01-01

Background Calcium-based and non-calcium-based phosphate binders have similar efficacy in the treatment of hyperphosphatemia; however, calcium-based binders may be associated with hypercalcemia, vascular calcification, and adynamic bone disease. Scope A post hoc analysis was carried out of data from a 16-week, Phase IV study of patients with end-stage renal disease (ESRD) who switched to lanthanum carbonate monotherapy from baseline calcium acetate/calcium carbonate monotherapy. Of the intent-to-treat population (N=2520), 752 patients with recorded dose data for calcium acetate (n=551)/calcium carbonate (n=201) at baseline and lanthanum carbonate at week 16 were studied. Elemental calcium intake, serum phosphate, corrected serum calcium, and serum intact parathyroid hormone levels were analyzed. Findings Of the 551 patients with calcium acetate dose data, 271 (49.2%) had an elemental calcium intake of at least 1.5 g/day at baseline, and 142 (25.8%) had an intake of at least 2.0 g/day. Mean (95% confidence interval [CI]) serum phosphate levels were 6.1 (5.89, 6.21) mg/dL at baseline and 6.2 (6.04, 6.38) mg/dL at 16 weeks; mean (95% CI) corrected serum calcium levels were 9.3 (9.16, 9.44) mg/dL and 9.2 (9.06, 9.34) mg/dL, respectively. Of the 201 patients with calcium carbonate dose data, 117 (58.2%) had an elemental calcium intake of at least 1.5 g/day, and 76 (37.8%) had an intake of at least 2.0 g/day. Mean (95% CI) serum phosphate levels were 5.8 (5.52, 6.06) mg/dL at baseline and 5.8 (5.53, 6.05) mg/dL at week 16; mean (95% CI) corrected serum calcium levels were 9.7 (9.15, 10.25) mg/dL and 9.2 (9.06, 9.34) mg/dL, respectively. Conclusion Calcium acetate/calcium carbonate phosphate binders, taken to control serum phosphate levels, may result in high levels of elemental calcium intake. This may lead to complications related to calcium balance. PMID:28182142

Kit W-sh Mutation Prevents Cancellous Bone Loss during Calcium Deprivation.

PubMed

Lotinun, Sutada; Suwanwela, Jaijam; Poolthong, Suchit; Baron, Roland

2018-01-01

Calcium is essential for normal bone growth and development. Inadequate calcium intake increases the risk of osteoporosis and fractures. Kit ligand/c-Kit signaling plays an important role in regulating bone homeostasis. Mice with c-Kit mutations are osteopenic. The present study aimed to investigate whether impairment of or reduction in c-Kit signaling affects bone turnover during calcium deprivation. Three-week-old male WBB6F1/J-Kit W /Kit W-v /J (W/W v ) mice with c-Kit point mutation, Kit W-sh /HNihrJaeBsmJ (W sh /W sh ) mice with an inversion mutation in the regulatory elements upstream of the c-Kit promoter region, and their wild-type controls (WT) were fed either a normal (0.6% calcium) or a low calcium diet (0.02% calcium) for 3 weeks. μCT analysis indicated that both mutants fed normal calcium diet had significantly decreased cortical thickness and cancellous bone volume compared to WT. The low calcium diet resulted in a comparable reduction in cortical bone volume and cortical thickness in the W/W v and W sh /W sh mice, and their corresponding controls. As expected, the low calcium diet induced cancellous bone loss in the W/W v mice. In contrast, W sh /W sh cancellous bone did not respond to this diet. This c-Kit mutation prevented cancellous bone loss by antagonizing the low calcium diet-induced increase in osteoblast and osteoclast numbers in the W sh /W sh mice. Gene expression profiling showed that calcium deficiency increased Osx, Ocn, Alp, type I collagen, c-Fms, M-CSF, and RANKL/OPG mRNA expression in controls; however, the W sh mutation suppressed these effects. Our findings indicate that although calcium restriction increased bone turnover, leading to osteopenia, the decreased c-Kit expression levels in the W sh /W sh mice prevented the low calcium diet-induced increase in cancellous bone turnover and bone loss but not the cortical bone loss.

Effect of particle size on calcium release and elevation of pH of endodontic cements.

PubMed

Saghiri, Mohammad Ali; Asatourian, Armen; Orangi, Jafar; Lotfi, Mehrdad; Soukup, Jason W; Garcia-Godoy, Franklin; Sheibani, Nader

2015-06-01

Elevation of pH and calcium ion release are of great importance in antibacterial activity and the promotion of dental soft and hard tissue healing process. In this study, we evaluated the effect of particle size on the elevation of pH and the calcium ion release from calcium silicate-based dental cements. Twelve plastic tubes were divided into three groups, filled with white mineral trioxide aggregate (WMTA), WMTA plus 1% methylcellulose, and nano-modified WMTA (nano-WMTA), and placed inside flasks containing 10 ml of distilled water. The pH values were measured using a pH sensor 3, 24, 72, and 168 h after setting of the cements. The calcium ion release was measured using an atomic absorption spectrophotometer with same sample preparation method. Data were subjected to two-way analysis of variance (anova) followed by post hoc Tukey tests with significance level of P < 0.05. Nano-WMTA showed significant pH elevation only after 24 h (P < 0.05) compared with WMTA, and after 3, 24, and 72 h compared with WMTA plus 1% methylcellulose (P < 0.05). Nano-WMTA showed significantly higher calcium ion release values compared to the other two groups (P < 0.05). Nano-modification of WMTA remarkably increased the calcium ion release at all time intervals postsetting, which can significantly influence the osteogenic properties of human dental pulp cells and as a consequence enhance mineralized matrix nodule formation to achieve desirable clinical outcomes. However, the increase in pH values mainly occurred during the short time postsetting. Addition of 1% methylcellulose imposed a delay in elevation of pH and calcium ion release by WMTA. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Molecular characterization of EcCIPK24 gene of finger millet (Eleusine coracana) for investigating its regulatory role in calcium transport.

PubMed

Chinchole, Mahadev; Pathak, Rajesh Kumar; Singh, Uma M; Kumar, Anil

2017-08-01

Finger millet grains contain exceptionally high levels of calcium which is much higher compared to other cereals and millets. Since calcium is an important macronutrient in human diet, it is necessary to explore the molecular basis of calcium accumulation in the seeds of finger millet. CIPK is a calcium sensor gene, having role in activating Ca 2+ exchanger protein by interaction with CBL proteins. To know the role of EcCIPK24 gene in seed Ca 2+ accumulation, sequence is retrieved from the transcriptome data of two finger millet genotypes GP1 (low Ca 2+ ) and GP45 (high Ca 2+ ), and the expression was determined through qRT-PCR. The higher expression was found in root, shoot, leaf and developing spike tissue of GP45 compared to GP1; structural analysis showed difference of nine SNPs and one extra beta sheet domain as well as differences in vacuolar localization was predicted; besides, the variation in amino acid composition among both the genotypes was also investigated. Molecular modeling and docking studies revealed that both EcCBL4 and EcCBL10 showed strong binding affinity with EcCIPK24 (GP1) compared to EcCIPK24 (GP45). It indicates a genotypic structural variation, which not only affects the affinity but also calcium transport efficiency after interaction of CIPK-CBL with calcium exchanger ( Ec CAX1b) to pull calcium in the vacuole. Based on the expression and in silico study, it can be suggested that by activating EcCAX1b protein, EcCIPK24 plays an important role in high seed Ca 2+ accumulation.

The beneficial effect of the sap of Acer mono in an animal with low-calcium diet-induced osteoporosis-like symptoms.

PubMed

Lee, Geun-Shik; Byun, Hyuk-Soo; Kim, Man-Hee; Lee, Bo-Mi; Ko, Sang-Hwan; Jung, Eui-Man; Gwak, Ki-Seob; Choi, In-Gyu; Kang, Ha-Young; Jo, Hyun-Jin; Lee, Hak-Ju; Jeung, Eui-Bae

2008-11-01

The sap of Acer mono has been called 'bone-benefit-water' in Korea because of its mineral and sugar content. In particular, the calcium concentration of the sap of A. mono is 37.5 times higher than commercial spring water. In the current study, we examined whether A. mono sap could improve or prevent osteoporosis-like symptoms in a mouse model. Male mice (3 weeks old) were fed a low-calcium diet supplemented with 25, 50 or 100 % A. mono sap, commercial spring water or a high calcium-containing solution as a beverage for 7 weeks. There were no differences in weekly weight gain and food intake among all the groups. Mice that were given a low-calcium diet supplemented with commercial spring water developed osteoporosis-like symptoms. To assess the effect of sap on osteoporosis-like symptoms, we examined serum calcium concentration, and femur density and length, and carried out a histological examination. Serum calcium levels were significantly lower in mice that received a low-calcium diet supplemented with commercial spring water (the negative control group), and in the 25 % sap group compared to mice fed a normal diet, but were normal in the 50 and 100 % sap and high-calcium solution groups. Femur density and length were significantly reduced in the negative control and 25 % sap groups. These results indicate that a 50 % sap solution can mitigate osteoporosis-like symptoms induced by a low-calcium diet. We also examined the regulation of expression of calcium-processing genes in the duodenum and kidney. Duodenal TRPV6 and renal calbindin-D9k were up-regulated dose-dependently by sap, and the levels of these factors were higher than those attained in the spring water-treated control. The results demonstrate that the sap of A. mono ameliorates the low bone density induced by a low-calcium diet, most likely by increasing calcium ion absorption.

Calcium nephrolithiasis: effect of water hardness on urinary electrolytes.

PubMed

Schwartz, Bradley F; Schenkman, Noah S; Bruce, Jeremy E; Leslie, Stephen W; Stoller, Marshall L

2002-07-01

To analyze the impact of water hardness from public water supplies on calcium stone incidence and 24-hour urine chemistries in patients with known calcium urinary stone formation. Patients are frequently concerned that their public water supply may contribute to urinary stone disease. Investigators have documented an inverse relationship between water hardness and calcium lithogenesis. Others have found no such association. Patients who form calcium stones (n = 4833) were identified geographically by their zip code. Water hardness information from distinct geographic public water supplies was obtained, and patient 24-hour urine chemistries were evaluated. Drinking water hardness was divided into decile rankings on the basis of the public water supply information obtained from the Environmental Protection Agency. These data were compared with patient questionnaires and 24-hour urine chemistries. The calcium and magnesium levels in the drinking water were analyzed as independent variables. The number of total lifetime stone episodes was similar between patients residing in areas with soft public water and hard public water. Patients consuming the softest water decile formed 3.4 lifetime stones and those who consumed the hardest water developed 3.0 lifetime stones (P = 0.0017). The 24-hour urine calcium, magnesium, and citrate levels increased directly with drinking water hardness, and no significant change was found in urinary oxalate, uric acid, pH, or volume. The impact of water hardness on urinary stone formation remains unclear, despite a weak correlation between water hardness and urinary calcium, magnesium, and citrate excretion. Tap water, however, can change urinary electrolytes in patients who form calcium stones.

Effect of curd washing on the properties of reduced-calcium and standard-calcium Cheddar cheese.

PubMed

Hou, Jia; McSweeney, Paul L H; Beresford, Thomas P; Guinee, Timothy P

2014-10-01

Washed (W) and nonwashed (NW) variants of standard (SCa) and reduced-calcium (RCa) Cheddar cheeses were made in triplicate, ripened for a 270-d period, and analyzed for composition and changes during maturation. Curd washing was applied to cheeses to give a target level of lactose plus lactic acid in cheese moisture of 3.9 g/100 g in the W cheese, compared with a value of 5.3 g/100 g of lactose plus lactic acid in cheese moisture in the control NW cheeses. The 4 cheese types were denoted standard calcium nonwashed (SCaNW), standard calcium washed (SCaW), reduced-calcium nonwashed (RCaNW), and reduced-calcium washed (RCaW). The mean calcium level was 760 mg/100 g in the SCaNW and SCaW and 660 mg/100 g in the RCaNW and RCaW cheeses. Otherwise the gross composition of all cheeses was similar, each with protein, fat, and moisture levels of ~26, 32, and 36 g/100 g, respectively. Curd washing significantly reduced the mean level of lactic acid in the SCaW cheese and residual lactose in both SCaW and RCaW cheeses. The mean pH of the standard-calcium cheese over the 270-d ripening period increased significantly with curd washing and ripening time, in contrast to the reduced-calcium cheese, which was not affected by the latter parameters. Otherwise curd washing had little effect on changes in populations of starter bacteria or nonstarter lactic acid bacteria, proteolysis, rheology, or color of the cheese during ripening. Descriptive sensory analysis at 270 d indicated that the SCaW cheese had a nuttier, sweeter, less fruity, and less rancid taste than the corresponding SCaNW cheese. In contrast, curd washing was not as effective in discriminating between the RCaW and RCaNW cheeses. The RCaW cheese had a more buttery, caramel odor and flavor, and a more bitter, less sweet, and nutty taste than the SCaW cheese, whereas the RCaNW had a more pungent and less fruity flavor, a less fruity odor, a saltier, more-bitter, and less acidic taste, and a more astringent mouthfeel than SCaNW. Washing of curd during manufacture provides a means of reducing the contents of lactic acid and residual lactose, increasing pH, and altering the sensory properties of Cheddar cheese, with the level of these effects being significantly less pronounced as the calcium content was reduced. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[Prevalence and quality of control of calcium and phosphorus metabolism disorders among Lithuanian hemodialysis patients in 2004 and 2005].

PubMed

Petrauskiene, Vaida; Ziginskiene, Edita; Kuzminskis, Vytautas; Burciuviene, Asta; Grazulis, Saulius; Sileikiene, Elvyra; Masalskiene, Jūrate; Juodeikiene, Laima; Tamosaitis, Donatas; Alisauskiene, Violeta

2007-01-01

The aim of the study was to determine the prevalence and quality of control of disorders of calcium and phosphorus metabolism among patients on hemodialysis in Lithuania during the period of 2004-2005 and to assess rarely used methods of treatment such as parathyroidectomy and administration of calcimimetics. All Lithuanian hemodialysis centers were visited, and data on disorders of calcium-phosphorus metabolism were collected in December 2004 and 2005. The quality of control was evaluated according to Kidney Disease Outcome Quality Initiative recommendations. According to Kidney Disease Outcome Quality Initiative guidelines, normal parathyroid hormone levels were found in 20.4% of hemodialysis patients in 2004 and 18.8% of hemodialysis patients in 2005; normal levels of phosphate were in 41.9% and 39.4%, respectively; normal levels of calcium were observed in 44.7% of patients in 2004 and in 42.3% of patients in 2005. In 2005 as compared to 2004, there were statistically significantly more patients with low parathyroid hormone level (39.9% and 45.8%, respectively, P<0.05). Only in 5.6% of patients in 2004 and 3.9% of patients in 2005, all four parameters of calcium-phosphate metabolism (calcium, phosphate, and of parathyroid hormone levels and calcium-phosphate product) were within the normal range. No parameters in the normal range were found in 17-20% of patients. The use of alfacalcidol significantly increased: 316 (30.8%) patients in 2004 and 388 (35.7%) patients in 2005 were treated with alfacalcidol (P<0.05). Alfacalcidol was prescribed for 16.5% of patients in 2004 and for 17% of patients in 2005, in whom parathyroid hormone level was below the normal range in the presence of hypercalcemia and hyperphosphatemia. The use of calcimimetics was considered rational in 142 (13.8%) patients in 2004 and 119 (10.9%) patients in 2005. According to the data of our study, parathyroidectomy was indicated in 19 (1.85%) patients in 2004 and 17 (1.56%) patients in 2005. According to Kidney Disease Outcome Quality Initiative recommendations, the control of disorders of calcium-phosphate metabolism in Lithuanian hemodialysis patients was insufficient in 2004 and 2005. One-third of the patients were treated with alfacalcidol when parathyroid hormone level was low and hypercalcemia and hyperphosphatemia persisted. Calcimimetics for the treatment of secondary hyperparathyroidism were administered in about 10% of patients.

Calcium is a key constituent for maintaining the in vitro properties of platelets suspended in the bicarbonate-containing additive solution M-sol with low plasma levels.

PubMed

Wagner, Stephen J; Skripchenko, Andrey; Myrup, Andrew; Thompson-Montgomery, Dedeene; Awatefe, Helen; Moroff, Gary

2010-05-01

Commercially available additive solutions (ASs) require 30% to 35% plasma for optimal storage of platelets (PLTs). PLTs suspended in M-sol, a bicarbonate-based experimental platelet additive solution (PAS), maintain in vitro PLT properties during storage with low levels of plasma (< or =5%). Four different formulations of M-sol were prepared at the optimal pH (6.1): M-sol, M-sol without calcium, M-sol without citric acid, and M-sol without calcium and citric acid. Apheresis PLT units (100% plasma) were equally divided into five 50-mL aliquots in PL732 containers, centrifuged, and resuspended to prepare units suspended in the four different PASs (95%) with 5% plasma and 1 unit in 100% plasma. Units (n = 10) were stored under standard conditions and assayed for in vitro properties on Days 1, 5, and 7. The data were analyzed by analysis of variance for repeated measures (n = 10, p < 0.001). On Day 5 of storage, PLTs suspended in the M-sol formulation containing calcium but lacking citric acid had similar pH, extent of shape change (ESC) values, and percentage of CD62-positive PLTs and greater hypotonic shock response (HSR) and percentage of discoid PLTs compared to those of PLTs suspended in 100% plasma. In contrast, PLTs suspended in the M-sol formulation lacking calcium had lesser ESC values, greater percentage of CD62-positive PLTs, and similar HSR values and percentage of discoid PLTs compared to those of PLTs suspended in 100% plasma on Day 5 (p < 0.001). Calcium plays an important role in maintaining CD62-negative PLTs and relatively high ESC in 5% plasma. The removal of citric acid from M-sol may improve PLT storage properties with low plasma levels.

Locomotion in Lymphocytes is Altered by Differential PKC Isoform Expression

NASA Technical Reports Server (NTRS)

Sundaresan, A.; Risin, D.; Pellis, N. R.

1999-01-01

Lymphocyte locomotion is critical for proper elicitation of the immune response. Locomotion of immune cells via the interstitium is essential for optimal immune function during wound healing, inflammation and infection. There are conditions which alter lymphocyte locomotion and one of them is spaceflight. Lymphocyte locomotion is severely inhibited in true spaceflight (true microgravity) and in rotating wall vessel culture (modeled microgravity). When lymphocytes are activated prior to culture in modeled microgravity, locomotion is not inhibited and the levels are comparable to those of static cultured lymphocytes. When a phorbol ester (PMA) is used in modeled microgravity, lymphocyte locomotion is restored by 87%. This occurs regardless if PMA is added after culture in the rotating wall vessel or during culture. Inhibition of DNA synthesis also does not alter restoration of lymphocyte locomotion by PMA. PMA is a direct activator of (protein kinase C) PKC . When a calcium ionophore, ionomycin is used it does not possess any restorative properties towards locomotion either alone or collectively with PMA. Since PMA brings about restoration without help from calcium ionophores (ionomycin), it is infer-red that calcium independent PKC isoforms are involved. Changes were perceived in the protein levels of PKC 6 where levels of the protein were downregulated at 24,72 and 96 hours in untreated rotated cultures (modeled microgravity) compared to untreated static (1g) cultures. At 48 hours there is an increase in the levels of PKC & in the same experimental set up. Studies on transcriptional and translational patterns of calcium independent isoforms of PKC such as 8 and E are presented in this study.

Estimation of Salivary and Serum Biomarkers in Diabetic and Non Diabetic Patients - A Comparative Study

PubMed Central

Ladgotra, Amit; Raj, Seetharamaiah Sunder

2016-01-01

Introduction Blood is the gold standard body fluid for diagnosis of Diabetes Mellitus (DM) but saliva offers an alternative to serum as a biological fluid for diagnostic purposes because it contains serum constituents. Aim The study was conducted to estimate and compare serum and salivary glucose, amylase, proteins, calcium and phosphorus levels in DM and healthy subjects and to evaluate whether saliva can be used as a diagnostic fluid in DM patients. Materials and Methods Study consisted of 120 subjects from OPD of Surendera Dental College, Sriganganagar, Rajasthan, India. The study groups were divided into Group I-60 DM patients (Type I & II) and Group II-60 healthy subjects. The saliva and serum samples were collected from each subject and levels of different biochemical parameters were estimated. Results Mean serum level of glucose (211.50 ± 43.82), amylase (79.86 ± 16.23), total proteins (6.65 ± 0.84), calcium (7.17 ± 0.91) and phosphorus (3.68±0.65) as observed in Group I while in Group II, glucose (88.81±11.29), amylase (77.67±14.88), total proteins (6.35±0.76), calcium (7.52±0.97) and phosphorus (3.96 ± 0.91) were noted. Mean salivary level of glucose (14.10±6.99), amylase (1671.42±569.86), total proteins (1.33±1.11), calcium (10.06±2.76) and phosphorus (13.75±4.45) as observed in Group I while in Group II, glucose (5.87± 2.42), amylase (1397.59 ±415.97), total proteins (1.36±0.81), calcium (7.73±2.78) and phosphorus (8.39 ± 1.95) were noted. On comparing values in saliva and serum, among two groups, an insignificant difference (p>0.005) was found between few of them. Conclusion Values regarding blood and salivary biochemical parameters were distinctly different between two groups suggesting salivary parameters can be used as a diagnostic alternative to blood parameters for diabetes mellitus. PMID:27504412

Effect of Potassium Citrate on Calcium Phosphate Stones in a Model of Hypercalciuria

PubMed Central

Asplin, John R.; Frick, Kevin K.; Granja, Ignacio; Culbertson, Christopher D.; Ng, Adeline; Grynpas, Marc D.; Bushinsky, David A.

2015-01-01

Potassium citrate is prescribed to decrease stone recurrence in patients with calcium nephrolithiasis. Citrate binds intestinal and urine calcium and increases urine pH. Citrate, metabolized to bicarbonate, should decrease calcium excretion by reducing bone resorption and increasing renal calcium reabsorption. However, citrate binding to intestinal calcium may increase absorption and renal excretion of both phosphate and oxalate. Thus, the effect of potassium citrate on urine calcium oxalate and calcium phosphate supersaturation and stone formation is complex and difficult to predict. To study the effects of potassium citrate on urine supersaturation and stone formation, we utilized 95th-generation inbred genetic hypercalciuric stone-forming rats. Rats were fed a fixed amount of a normal calcium (1.2%) diet supplemented with potassium citrate or potassium chloride (each 4 mmol/d) for 18 weeks. Urine was collected at 6, 12, and 18 weeks. At 18 weeks, stone formation was visualized by radiography. Urine citrate, phosphate, oxalate, and pH levels were higher and urine calcium level was lower in rats fed potassium citrate. Furthermore, calcium oxalate and calcium phosphate supersaturation were higher with potassium citrate; however, uric acid supersaturation was lower. Both groups had similar numbers of exclusively calcium phosphate stones. Thus, potassium citrate effectively raises urine citrate levels and lowers urine calcium levels; however, the increases in urine pH, oxalate, and phosphate levels lead to increased calcium oxalate and calcium phosphate supersaturation. Potassium citrate induces complex changes in urine chemistries and resultant supersaturation, which may not be beneficial in preventing calcium phosphate stone formation. PMID:25855777

Hypercalcemia in hyperthyroidism: patterns of serum calcium, parathyroid hormone, and 1,25-dihydroxyvitamin D3 levels during management of thyrotoxicosis.

PubMed

Iqbal, Ayesha A; Burgess, Elizabeth H; Gallina, Daniel L; Nanes, Mark S; Cook, Curtiss B

2003-01-01

To present two cases of hypercalcemia associated with thyrotoxicosis and to describe serial biochemical findings during the course of treatment of hyperthyroidism. We report two cases, illustrate the changes in serum calcium, parathyroid hormone, and 1,25-dihydroxyvitamin D3 levels during management of thyrotoxicosis, and compare our findings with those in previous studies. Hypercalcemia attributable to thyrotoxicosis is well documented, but the mechanism for the hypercalcemia is incompletely understood. Our first patient had a complicated medical history and several potential causes of hypercalcemia, including recurrent hyperparathyroidism, metastatic breast cancer, and relapse of previously treated thyrotoxicosis. A suppressed parathyroid hormone level and negative bone and computed tomographic scans excluded the first two factors. After thyroid ablation with 131I, the serum calcium and thyroxine levels decreased, and the parathyroid hormone and 1,25-dihydroxyvitamin D3 levels normalized. Our second patient, who was referred to our institution with a preliminary diagnosis of hypercalcemia associated with malignant disease and who had no symptoms of hyperthyroidism, was found to have a high free thyroxine level, diffuse enlargement of the thyroid, and high uptake (58%) of 123I on a thyroid scan. After thyroid ablation, the serum calcium, 1,25-dihydroxyvitamin D3, and intact parathyroid hormone levels normalized, and the free thyroxine level declined. The probable pathogenesis of hypercalcemia in thyrotoxicosis is reviewed with respect to thyroid hormone and its effect on bone turnover. Physicians should consider thyrotoxicosis in the differential diagnosis of hypercalcemia.

Therapeutic effects of aqueous extracts of Petroselinum sativum on ethylene glycol-induced kidney calculi in rats.

PubMed

Saeidi, Jafar; Bozorgi, Hadi; Zendehdel, Ahmad; Mehrzad, Jamshid

2012-01-01

To investigate the therapeutic effects of the aqueous extract of Petroselinum Sativum aerial parts and roots on kidney calculi. Thirty-six male Wistar rats were randomly assigned into 6 groups and treated for 30 days. Group A served as normal control and group B received 1% ethylene glycol in drinking water. Groups C, D, E, and F received 1% ethylene glycol from day 0 and were used as the treatment subjects. Rats in groups C and D received 200 and 600 mg/kg body weight of aerial parts aqueous extract, respectively, and those in groups E and F received 200 and 600 mg/kg body weight of root aqueous extract in drinking water, respectively, from the 14th day of the experiment. On the 14th and 30th days of the experiment, serum level of magnesium (1.71 ± 0.12 and 3.81 ± 0.25, respectively) decreased significantly while serum level of calcium (10.45 ± 0.26 and 11.33 ± 0.18, respectively) increased significantly in group B compared with the control group (14th day: magnesium = 2.87 ± 0.17 and calcium = 8.80 ± 0.00 and 30th day: magnesium = 6.01 ± 0.00 and calcium = 8.30 ± 0.22; P < .001). In the treatment groups of C, D, E, and F, the number of deposits decreased significantly compared with group B on the 30th day (P < .001). The weight of the kidneys increased significantly in group B (2.01 ± 0.17) compared with the control group (1.52 ± 0.07) and decreased significantly in treatment groups (P < .05). Petroselinum Sativum has a therapeutic effect on calcium oxalate stones in rats with nephrolithiasis and reduces the number of calcium oxalate deposits.

Effects of Oxcarbazepine and Levetiracetam on Calcium, Ionized Calcium, and 25-OH Vitamin-D3 Levels in Patients with Epilepsy.

PubMed

Aksoy, Duygu; Güveli, Betül Tekin; Ak, Pelin Doğan; Sarı, Hüseyin; Ataklı, Dilek; Arpacı, Baki

2016-02-29

The primary objective of the present study was to further elucidate the effects of oxcarbazepine (OXC) and levetiracetam (LEV) monotherapies on the bone health status of patients with epilepsy. This study included 48 patients who attended our epilepsy outpatient clinic, had a diagnosis of epilepsy, and were undergoing either OXC or LEV monotherapy and 42 healthy control subjects. The demographic and clinical features of the patients, including gender, age, onset of disease, daily drug dosage, and duration of disease, were noted. Additionally, the calcium, ionized calcium, and 25-OH vitamin-D3 levels of the participants were prospectively evaluated. The 25-OH vitamin-D3, calcium, and ionized calcium levels of the patients taking OXC were significantly lower than those of the control group. These levels did not significantly differ between the patients taking LEV and the control group, but there was a significant negative relationship between daily drug dose and ionized calcium levels in the LEV patients. In the present study, anti-epileptic drugs altered the calcium, ionized calcium, and 25-OH vitamin-D3 levels of epilepsy patients and resulted in bone loss, abnormal mineralization, and fractures. These findings suggest that the calcium, ionized calcium, and 25-OH vitamin-D3 levels of patients with epilepsy should be regularly assessed.

Women with Fibromyalgia Have Lower Levels of Calcium, Magnesium, Iron and Manganese in Hair Mineral Analysis

PubMed Central

Kim, Young-Sang; Kim, Kwang-Min; Lee, Duck-Joo; Kim, Bom-Taeck; Park, Sat-Byul; Cho, Doo-Yeoun; Suh, Chang-Hee; Kim, Hyoun-Ah; Park, Rae-Woong

2011-01-01

Little is known about hair mineral status in fibromyalgia patients. This study evaluated the characteristics of hair minerals in female patients with fibromyalgia compared with a healthy reference group. Forty-four female patients diagnosed with fibromyalgia according to the American College of Rheumatology criteria were enrolled as the case group. Ageand body mass index-matched data were obtained from 122 control subjects enrolled during visit for a regular health check-up. Hair minerals were analyzed and compared between the two groups. The mean age was 43.7 yr. General characteristics were not different between the two groups. Fibromyalgia patients showed a significantly lower level of calcium (775 µg/g vs 1,093 µg/g), magnesium (52 µg/g vs 72 µg/g), iron (5.9 µg/g vs 7.1 µg/g), copper (28.3 µg/g vs 40.2 µg/g) and manganese (140 ng/g vs 190 ng/g). Calcium, magnesium, iron, and manganese were loaded in the same factor using factor analysis; the mean of this factor was significantly lower in fibromyalgia group in multivariate analysis with adjustment for potential confounders. In conclusion, the concentrations of calcium, magnesium, iron, and manganese in the hair of female patients with fibromyalgia are lower than of controls, even after adjustment of potential confounders. PMID:22022174

Dental caries in diabetes mellitus: role of salivary flow rate and minerals.

PubMed

Jawed, Muhammad; Shahid, Syed M; Qader, Shah A; Azhar, Abid

2011-01-01

This study was designed to evaluate the possible protective role of salivary factors like salivary flow rate and adequate level of calcium, phosphate, and fluoride in diabetes mellitus type 2 patients with dental caries. A total of 398 diabetes mellitus type 2 patients with dental caries and 395 age- and sex-matched non-diabetic subjects with dental caries were included as controls, all of whom gave informed consent. All subjects were divided into four groups according to their age. Decayed, missed, and filled teeth (DMFT) were scored to indicate the severity of dental caries. Saliva was collected, flow rate was noted, and calcium, phosphate, and fluoride were analyzed. The blood glucose, HbA1c, and DMFT indices were found to be significantly high in diabetic patients as compared to controls. The salivary flow rate, calcium, phosphate, and fluoride were found to be significantly low whereas no significant difference was found in salivary magnesium in patients as compared to controls. Optimum salivary flow rate is responsible for establishing protective environment against dental caries. Adequate level of salivary calcium, phosphate, and fluoride is also involved in significant deposition of these minerals in plaque, which greatly reduces the development of caries in the adjacent enamel of teeth. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of the Administration of 25(OH) Vitamin D3 in an Experimental Model of Chronic Kidney Disease in Animals Null for 1-Alpha-Hydroxylase.

PubMed

Torremadé, Noelia; Bozic, Milica; Goltzman, David; Fernandez, Elvira; Valdivielso, José M

2017-01-01

The final step in vitamin D activation is catalyzed by 1-alpha-hydroxylase (CYP27B1). Chronic kidney disease (CKD) is characterized by low levels of both 25(OH)D3 and 1,25(OH)2D3 provoking secondary hyperparathyroidism (2HPT). Therefore, treatments with active or native vitamin D compounds are common in CKD to restore 25(OH)D3 levels and also to decrease PTH. This study evaluates the dose of 25(OH)D3 that restores parathyroid hormone (PTH) and calcium levels in a model of CKD in CYP27B1-/- mice. Furthermore, we compare the safety and efficacy of the same dose in CYP27B1+/+ animals. The dose needed to decrease PTH levels in CYP27B1-/- mice with CKD was 50 ng/g. That dose restored blood calcium levels without modifying phosphate levels, and increased the expression of genes responsible for calcium absorption (TRPV5 and calbindinD- 28K in the kidney, TRPV6 and calbindinD-9k in the intestine). The same dose of 25(OH)D3 did not modify PTH in CYP27B1+/+ animals with CKD. Blood calcium remained normal, while phosphate increased significantly. Blood levels of 25(OH)D3 in CYP27B1-/- mice were extremely high compared to those in CYP27B1+/+ animals. CYP27B1+/+ animals with CKD showed increases in TRPV5, TRPV6, calbindinD-28K and calbindinD-9K, which were not further elevated with the treatment. Furthermore, CYP27B1+/+ animals displayed an increase in vascular calcification. We conclude that the dose of 25(OH)D3 effective in decreasing PTH levels in CYP27B1-/- mice with CKD, has a potentially toxic effect in CYP27B1+/+ animals with CKD.

Changes in parameters of bone metabolism in postmenopausal women following a 12-month intervention period using dairy products enriched with calcium, vitamin D, and phylloquinone (vitamin K(1)) or menaquinone-7 (vitamin K (2)): the Postmenopausal Health Study II.

PubMed

Kanellakis, Spyridon; Moschonis, George; Tenta, Roxane; Schaafsma, Anne; van den Heuvel, Ellen G H M; Papaioannou, Nikolaos; Lyritis, George; Manios, Yannis

2012-04-01

The objective of the present study was to examine the effect of dairy products enriched with calcium, vitamin D(3), and phylloquinone (vitamin K(1)) or menaquinone-7 (vitamin K(2)) on parameters of bone metabolism in postmenopausal women following a 12-month intervention. Postmenopausal women were divided into three intervention groups and a control group (CG). All three intervention groups attended biweekly sessions and received fortified dairy products providing daily 800 mg of calcium and 10 μg of vitamin D(3) (CaD). Furthermore, in two of the three intervention groups the dairy products were also enriched with vitamin K, providing daily 100 μg of either phylloquinone (CaDK1) or menaquinone-7 (CaDK2). The increase observed for serum 25(OH)D levels in all intervention groups and the increase observed for serum IGF-I levels in the CaDK2 group differed significantly compared to the changes observed in CG (P = 0.010 and P = 0.028, respectively). Furthermore, both the CaDK1 and CaDK2 groups had a significantly lower mean serum undercarboxylated osteocalcin to osteocalcin ratio and urine deoxypyridinoline levels at follow-up compared to the CaD and CG groups (P = 0.001 and P = 0.047, respectively). Significant increases in total-body BMD were observed in all intervention groups compared to CG (P < 0.05), while significant increases in lumbar spine BMD were observed only for CaDK1 and CaDK2 compared to CG (P < 0.05) after controlling for changes in serum 25(OH)D levels and dietary calcium intake. In conclusion, the present study revealed more favorable changes in bone metabolism and bone mass indices for the two vitamin K-supplemented groups, mainly reflected in the suppression of serum levels of bone remodeling indices and in the more positive changes in lumbar spine BMD for these two study groups.

Calcium regulation of oxidative phosphorylation in rat skeletal muscle mitochondria.

PubMed

Kavanagh, N I; Ainscow, E K; Brand, M D

2000-02-24

Activation of oxidative phosphorylation by physiological levels of calcium in mitochondria from rat skeletal muscle was analysed using top-down elasticity and regulation analysis. Oxidative phosphorylation was conceptually divided into three subsystems (substrate oxidation, proton leak and phosphorylation) connected by the membrane potential or the protonmotive force. Calcium directly activated the phosphorylation subsystem and (with sub-saturating 2-oxoglutarate) the substrate oxidation subsystem but had no effect on the proton leak kinetics. The response of mitochondria respiring on 2-oxoglutarate at two physiological concentrations of free calcium was quantified using control and regulation analysis. The partial integrated response coefficients showed that direct stimulation of substrate oxidation contributed 86% of the effect of calcium on state 3 oxygen consumption, and direct activation of the phosphorylation reactions caused 37% of the increase in phosphorylation flux. Calcium directly activated phosphorylation more strongly than substrate oxidation (78% compared to 45%) to achieve homeostasis of mitochondrial membrane potential during large increases in flux.

Hypocalcaemia after total thyroidectomy for Graves' disease and for benign atoxic multinodular goitre.

PubMed

Hallgrimsson, Páll; Nordenström, E; Bergenfelz, A; Almquist, M

2012-10-01

Postoperative hypocalcaemia has been reported to be more common after total thyroidectomy (TT) for Graves' disease than after TT for benign atoxic multinodular goitre (MNG). The reasons for this potential association are not clear. In the present study, the frequency and risk factors of hypocalcaemia after TT for Graves' vs MNG were compared. Between January 1999 and October 2009, patients with first-time surgery for Graves' disease or MNG treated with a TT were included in the study. Postoperative hypocalcaemia was defined by symptoms, calcium levels and treatment with calcium and/or vitamin D analogues during postoperative hospital stay, at discharge, and at the 6-week and 6-month follow-ups. Outcomes were compared with Mann-Whitney, chi(2) and Fishers' exact test where appropriate and by multivariable logistic regression analysis. There were 128 patients with Graves' disease and 81 patients with MNG. Patients with Graves' disease were younger than patients with MNG (median age, 35 vs 51 years, p < 0.001). Symptoms of hypocalcaemia were more common in patients with Graves' disease (p < 0.001; OR, 95 % CI 3.26, 1.48-7.14), but the frequency of biochemical hypocalcaemia, postoperative levels of parathyroid hormone (PTH) and treatment with calcium and vitamin D did not differ between groups of patients. Apart from more frequent symptoms of hypocalcaemia in patients with Graves' disease, there was no difference in the overall frequency of biochemical hypocalcaemia, low levels of PTH and/or treatment with calcium and vitamin D.

Dietary calcium intake and renin angiotensin system polymorphisms alter the blood pressure response to aerobic exercise: a randomized control design.

PubMed

Pescatello, Linda S; Turner, Debbie; Rodriguez, Nancy; Blanchard, Bruce E; Tsongalis, Gregory J; Maresh, Carl M; Duffy, Valerie; Thompson, Paul D

2007-01-04

Dietary calcium intake and the renin angiotensin system (RAS) regulate blood pressure (BP) by modulating calcium homeostasis. Despite similar BP regulatory effects, the influence of dietary calcium intake alone and combined with RAS polymorphisms on the BP response following acute aerobic exercise (i.e., postexercise hypotension) has not been studied. Thus, we examined the effect of dietary calcium intake and selected RAS polymorphisms on postexercise hypotension. Subjects were men (n = 50, 43.8 +/- 1.3 yr) with high BP (145.3 +/- 1.5/85.9 +/- 1.1 mm Hg). They completed three experiments: non-exercise control and two cycle bouts at 40% and 60% of maximal oxygen consumption (VO2max). Subjects provided 3 d food records on five protocol-specific occasions. Dietary calcium intake was averaged and categorized as low (<880 mg/d = LowCa) or high (> or = 880 mg/d = HighCa). RAS polymorphisms (angiotensin converting enzyme insertion/deletion, ACE I/D; angiotensin II type 1 receptor, AT1R A/C) were analyzed with molecular methods. Genotypes were reduced from three to two: ACE II/ID and ACE DD; or AT1R AA and AT1R CC/AC. Repeated measure ANCOVA tested if BP differed among experiments, dietary calcium intake level and RAS polymorphisms. Systolic BP (SBP) decreased 6 mm Hg after 40% and 60% VO2max compared to non-exercise control for 10 h with LowCa (p < 0.01), but not with HighCa (p > or = 0.05). Under these conditions, diastolic BP (DBP) did not differ between dietary calcium intake levels (p > or = 0.05). With LowCa, SBP decreased after 60% VO2max versus non-exercise control for 10 h among ACE II/ID (6 mm Hg) and AT1R AA (8 mm Hg); and by 8 mm Hg after 40% VO2max among ACE DD and AT1R CC/CA (p < 0.01). With HighCa, SBP (8 mm Hg) and DBP (4 mm Hg) decreased after 60% VO2max compared to non-exercise control for 10 h (p < 0.05), but not after 40% VO2max (p > or = 0.05). SBP decreased after exercise compared to non-exercise control among men with low but not high dietary calcium intake. Dietary calcium intake interacted with the ACE I/D and AT1R A/C polymorphisms to further modulate postexercise hypotension. Interactions among dietary calcium intake, exercise intensity and RAS polymorphisms account for some of the variability in the BP response to exercise.

Calcium homeostasis in intraerythrocytic malaria parasites.

PubMed

Garcia, C R; Dluzewski, A R; Catalani, L H; Burting, R; Hoyland, J; Mason, W T

1996-12-01

The fluorescent indicator, fura-2, AM, was used to measure free calcium concentrations in the intraerythrocytic malaria parasites of Plasmodium chabaudi and Plasmodium falciparum. In both species the free cytosolic calcium concentration was maintained at low levels (between 40 and 100 nM throughout the maturation process. Digital image analysis of the indicator fluorescence was performed on parasites and evaluated with the aid of a calibration of the calcium response, based on permeabilized parasites, exposed to calcium buffers. This again revealed that free calcium concentrations in the intact parasite are maintained at a predetermined level, regardless of the free calcium in the surrounding milieu. Both species of parasites are thus capable of regulating their internal free calcium levels with high precision, presumably by means of calcium pump ATPases. A small but significant elevation of the cytosolic free calcium concentration by the tumor promoter, thapsigargin, may be taken to reflect the presence of calcium stores in the endoplasmic reticulum in P. falciparum.

Effect of beta-amyloid block of the fast-inactivating K+ channel on intracellular Ca2+ and excitability in a modeled neuron.

PubMed

Good, T A; Murphy, R M

1996-12-24

beta-Amyloid peptide (A beta), one of the primary protein components of senile plaques found in Alzheimer disease, is believed to be toxic to neurons by a mechanism that may involve loss of intracellular calcium regulation. We have previously shown that A beta blocks the fast-inactivating potassium (A) current. In this work, we show, through the use of a mathematical model, that the A beta-mediated block of the A current could result in increased intracellular calcium levels and increased membrane excitability, both of which have been observed in vitro upon acute exposure to A beta. Simulation results are compared with experimental data from the literature; the simulations quantitatively capture the observed concentration dependence of the neuronal response and the level of increase in intracellular calcium.

[Relationship between the ionic composition of blood and urine and the salinity of the external environment of the crab Hemigrapsus sanguineus].

PubMed

Busev, V M; Semen'kov, P G; Mishchenko, T Ia

1977-01-01

Studies have been made on the dependence of sodium, potassium, magnesium and calcium concentrations of the blood and urine on the salinity of the external milieu in the crab H. sanguineus. Effective regulation of sodium and potasssium balance at low salinities was found. Within the salinity range investigated, magnesium level in the blood is maintained at lower level as compared to that in the environment. At low salinities, regulation of potassium and sodium concentrations in the blood is monitored by extrarenal mechanisms. Uber high salinity conditions, regulation of magnesium and potassium concentrations in the blood is accomplished at the expense of the activity of antennal glands. Calcium concentration in the blood is regulated by extra-renal mechanisms. The antennal glands affect regulation of calcium balance.

Dietary Calcium Intake and Adherence to the Mediterranean Diet in Spanish Children: The ANIVA Study.

PubMed

Rubio-López, Nuria; Llopis-González, Agustín; Picó, Yolanda; Morales-Suárez-Varela, María

2017-06-14

The aim of this study was to evaluate the relationship of dietary calcium intake with anthropometric measures, physical activity and adherence to the Mediterranean diet (MedDiet) in 1176 Spanish children aged 6-9 years. Data were obtained from "Antropometría y Nutrición Infantil de Valencia" (ANIVA), a cross-sectional study of a representative sample. Dietary calcium intake assessed from three-day food records was compared to recommended daily intakes in Spain. Anthropometric measures (weight and height) were measured according to international standards and adherence to the MedDiet was evaluated using the Mediterranean Diet Quality Index (KIDMED) test. For the total sample of children, 25.8% had inadequate calcium intake, a significantly higher prevalence in girls ( p = 0.006) and inadequate calcium intake was associated with lower height z-score ( p = 0.001) for both sexes. In girls, there was an inverse relationship between calcium intake and body mass index ( p = 0.001) and waist/hip ratio ( p = 0.018). Boys presented a polarization in physical activity, reporting a greater level of both physical and sedentary activity in comparison with girls ( p = 0.001). Children with poor adherence to MedDiet, even if they consume two yogurts or cheese (40 g) daily, adjusted by gender, age, total energy intake, physical activity and father's level of education, are at risk of inadequate total calcium intake (odds ratio adjusted [ORa]: 3.36, 95% confidence interval [CI]: 1.13-9.94, p = 0.001). The intake of these dairy products was insufficient to cover calcium intake recommendations in this age group (6-9 years). It is important to prioritize health strategies that promote the MedDiet and to increase calcium intake in this age group.

Demographic, dietary, and urinary factors and 24-h urinary calcium excretion.

PubMed

Taylor, Eric N; Curhan, Gary C

2009-12-01

Higher urinary calcium is a risk factor for nephrolithiasis. This study delineated associations between demographic, dietary, and urinary factors and 24-h urinary calcium. Cross-sectional studies were conducted of 2201 stone formers (SF) and 1167 nonstone formers (NSF) in the Health Professionals Follow-up Study (men) and Nurses' Health Studies I and II (older and younger women). Median urinary calcium was 182 mg/d in men, 182 mg/d in older women, and 192 mg/d in younger women. Compared with NSF, urinary calcium as a fraction of calcium intake was 33 to 38% higher in SF (P values < or =0.01). In regression analyses, participants were combined because associations with urinary calcium were similar in each cohort and in SF and NSF. After multivariate adjustment, participants in the highest quartile of calcium intake excreted 18 mg/d more urinary calcium than those in the lowest (P trend =0.01). Caffeine and family history of nephrolithiasis were positively associated, whereas urinary potassium, thiazides, gout, and age were inversely associated, with urinary calcium. After multivariate adjustment, participants in the highest quartiles of urinary magnesium, sodium, sulfate, citrate, phosphorus, and volume excreted 71 mg/d, 37 mg/d, 44 mg/d, 61 mg/d, 37 mg/d, and 24 mg/d more urinary calcium, respectively, than participants in the lowest (P values trend < or =0.01). Intestinal calcium absorption and/or negative calcium balance is greater in SF than NSF. Higher calcium intakes at levels typically observed in free-living individuals are associated with only small increases in urinary calcium.

Serum Estradiol and Testosterone Levels in Kidney Stones Disease with and without Calcium Oxalate Components in Naturally Postmenopausal Women

PubMed Central

Ou, Lili; Duan, Xiaolu; Zeng, Guohua

2013-01-01

Objective Epidemiological data reveal that the overall risk for kidney stones disease is lower for women compared to age-matched men. However, the beneficial effect for the female sex is lost upon menopause, a time corresponding to the onset of fall in estrogen levels. The aim of this study was to describe the serum estradiol (E2) and testosterone (T) characteristics of naturally postmenopausal women with kidney stones. Methods 113 naturally postmenopausal women with newly diagnosed kidney stones (aged 57.4±4.98 years) and 84 age frequency matched stone-free controls (56.9±4.56 years) were validly recruited in the case-control study. The odds ratios (ORs) for the associations between sex hormones and kidney stones were estimated with logistic regression models, adjusting for demographic data and medical history. Patients were also stratified analyzed according to stone components (calcium oxalate stones [COS]; non-calcium oxalate stones [NCOS]). Results Serum E2 (21.1 vs. 31.1 pg/ml) was significantly lower in kidney stones patients compared to controls. Post-hoc analysis demonstrated that this effect was driven by COS patients (p<0.001). According to tertiles of the E2 levels, a significant higher frequency of COS was seen in the lowest E2 group (p <0.001). Multiple logistic regression analysis identified E2 level as a strong factor that was independently associated with the risk for COS (per 1 SD increase, OR=0.951, 95% confidence interval [CI] = 0.919-0.985; highest: lowest tertile, OR=0.214, 95%CI = 0.069-0.665). However, serum T levels did not significantly differ among the groups. Conclusions Naturally postmenopausal women with higher remaining estradiol levels appear less likely to suffer from kidney calcium oxalate stones. However, no correlation was found between serum T level and kidney stones. These findings support the hypothesis that higher postmenopausal endogenous estrogens may protect against kidney stones with ageing. PMID:24086550

Serum estradiol and testosterone levels in kidney stones disease with and without calcium oxalate components in naturally postmenopausal women.

PubMed

Zhao, Zhijian; Mai, Zanlin; Ou, Lili; Duan, Xiaolu; Zeng, Guohua

2013-01-01

Epidemiological data reveal that the overall risk for kidney stones disease is lower for women compared to age-matched men. However, the beneficial effect for the female sex is lost upon menopause, a time corresponding to the onset of fall in estrogen levels. The aim of this study was to describe the serum estradiol (E2) and testosterone (T) characteristics of naturally postmenopausal women with kidney stones. 113 naturally postmenopausal women with newly diagnosed kidney stones (aged 57.4±4.98 years) and 84 age frequency matched stone-free controls (56.9±4.56 years) were validly recruited in the case-control study. The odds ratios (ORs) for the associations between sex hormones and kidney stones were estimated with logistic regression models, adjusting for demographic data and medical history. Patients were also stratified analyzed according to stone components (calcium oxalate stones [COS]; non-calcium oxalate stones [NCOS]). Serum E2 (21.1 vs. 31.1 pg/ml) was significantly lower in kidney stones patients compared to controls. Post-hoc analysis demonstrated that this effect was driven by COS patients (p<0.001). According to tertiles of the E2 levels, a significant higher frequency of COS was seen in the lowest E2 group (p <0.001). Multiple logistic regression analysis identified E2 level as a strong factor that was independently associated with the risk for COS (per 1 SD increase, OR=0.951, 95% confidence interval [CI] = 0.919-0.985; highest: lowest tertile, OR=0.214, 95%CI = 0.069-0.665). However, serum T levels did not significantly differ among the groups. Naturally postmenopausal women with higher remaining estradiol levels appear less likely to suffer from kidney calcium oxalate stones. However, no correlation was found between serum T level and kidney stones. These findings support the hypothesis that higher postmenopausal endogenous estrogens may protect against kidney stones with ageing.

Pulsed electromagnetic fields promote the proliferation and differentiation of osteoblasts by reinforcing intracellular calcium transients.

PubMed

Tong, Jie; Sun, Lijun; Zhu, Bin; Fan, Yun; Ma, Xingfeng; Yu, Liyin; Zhang, Jianbao

2017-10-01

Pulsed electromagnetic fields (PEMF) can be used to treat bone-related diseases, but the underlying mechanism remains unclear, especially the process by which PEMFs initiate biological effects. In this study, we demonstrated the effects of PEMF on proliferation and differentiation of osteoblasts using the model of calcium transients induced by high extracellular calcium. Our results showed that PEMF can increase both the percentage of responding cells and amplitude of intracellular calcium transients induced by high extracellular calcium stimulation. Compared with corresponding extracellular calcium levels, PEMF stimulation increased proliferation and differentiation of osteoblasts and related gene expressions, such as insulin-like growth factor 1 (IGF-1), alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), which can be completely abolished by BAPTA-AM. Moreover, PEMF did not affect proliferation and differentiation of osteoblasts if no intracellular calcium transient was present in osteoblasts during PEMF exposure. Our results revealed that PEMF affects osteoblast proliferation and differentiation through enhanced intracellular calcium transients, which provided a cue to treat bone-related diseases with PEMF. Bioelectromagnetics. 38:541-549, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Mechanics regulates ATP-stimulated collective calcium response in fibroblast cells

PubMed Central

Lembong, Josephine; Sabass, Benedikt; Sun, Bo; Rogers, Matthew E.; Stone, Howard A.

2015-01-01

Cells constantly sense their chemical and mechanical environments. We study the effect of mechanics on the ATP-induced collective calcium response of fibroblast cells in experiments that mimic various tissue environments. We find that closely packed two-dimensional cell cultures on a soft polyacrylamide gel (Young's modulus E = 690 Pa) contain more cells exhibiting calcium oscillations than cultures on a rigid substrate (E = 36 000 Pa). Calcium responses of cells on soft substrates show a slower decay of calcium level relative to those on rigid substrates. Actin enhancement and disruption experiments for the cell cultures allow us to conclude that actin filaments determine the collective Ca2+ oscillatory behaviour in the culture. Inhibition of gap junctions results in a decrease of the oscillation period and reduced correlation of calcium responses, which suggests additional complexity of signalling upon cell–cell contact. Moreover, the frequency of calcium oscillations is independent of the rigidity of the substrate but depends on ATP concentration. We compare our results with those from similar experiments on individual cells. Overall, our observations show that collective chemical signalling in cell cultures via calcium depends critically on the mechanical environment. PMID:26063818

Idiopathic hypercalciuria and formation of calcium renal stones

PubMed Central

Coe, Fredric L.; Worcester, Elaine M.; Evan, Andrew P.

2018-01-01

The most common presentation of nephrolithiasis is idiopathic calcium stones in patients without systemic disease. Most stones are primarily composed of calcium oxalate and form on a base of interstitial apatite deposits, known as Randall’s plaque. By contrast some stones are composed largely of calcium phosphate, as either hydroxyapatite or brushite (calcium monohydrogen phosphate), and are usually accompanied by deposits of calcium phosphate in the Bellini ducts. These deposits result in local tissue damage and might serve as a site of mineral overgrowth. Stone formation is driven by supersaturation of urine with calcium oxalate and brushite. The level of supersaturation is related to fluid intake as well as to the levels of urinary citrate and calcium. Risk of stone formation is increased when urine citrate excretion is <400 mg per day, and treatment with potassium citrate has been used to prevent stones. Urine calcium levels >200 mg per day also increase stone risk and often result in negative calcium balance. Reduced renal calcium reabsorption has a role in idiopathic hypercalciuria. Low sodium diets and thiazide-type diuretics lower urine calcium levels and potentially reduce the risk of stone recurrence and bone diseas PMID:27452364

Keratinocytes negatively regulate the N-cadherin levels of melanoma cells via contact-mediated calcium regulation.

PubMed

Chung, Heesung; Jung, Hyejung; Jho, Eek-Hoon; Multhaupt, Hinke A B; Couchman, John R; Oh, Eok-Soo

2018-06-14

In human skin, melanocytes and their neighboring keratinocytes have a close functional interrelationship. Keratinocytes, which represent the prevalent cell type of human skin, regulate melanocytes through various mechanisms. Here, we use a keratinocyte and melanoma co-culture system to show for the first time that keratinocytes regulate the cell surface expression of N-cadherin through cell-cell contact. Compared to mono-cultured human melanoma A375 cells, which expressed high levels of N-cadherin, those co-cultured with the HaCaT human keratinocyte cell line showed reduced levels of N-cadherin. This reduction was most evident in areas of A375 cells that underwent cell-cell contact with the HaCaT cells, whereas HaCaT cell-derived extracellular matrix and conditioned medium both failed to reduce N-cadherin levels. The intracellular level of calcium in co-cultured A375 cells was lower than that in mono-cultured A375 cells, and treatment with a cell-permeant calcium chelator (BAPTA) reduced the N-cadherin level of mono-cultured A375 cells. Furthermore, co-culture with HaCaT cells reduced the expression levels of transient receptor potential cation channel (TRPC) 1, -3 and -6 in A375 cells, and siRNA-mediated multi-depletion of TRPC1, -3 and -6 reduced the N-cadherin level in these cells. Taken together, these data suggest that keratinocytes negatively regulate the N-cadherin levels of melanoma cells via cell-to-cell contact-mediated calcium regulation. Copyright © 2018. Published by Elsevier Inc.

Extension of a PBPK model for ethylene glycol and glycolic acid to include the competitive formation and clearance of metabolites associated with kidney toxicity in rats and humans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corley, R.A., E-mail: rick.corley@pnl.gov; Saghir, S.A.; Bartels, M.J.

2011-02-01

A previously developed PBPK model for ethylene glycol and glycolic acid was extended to include glyoxylic acid, oxalic acid, and the precipitation of calcium oxalate that is associated with kidney toxicity in rats and humans. The development and evaluation of the PBPK model was based upon previously published pharmacokinetic studies coupled with measured blood and tissue partition coefficients and rates of in vitro metabolism of glyoxylic acid to oxalic acid, glycine and other metabolites using primary hepatocytes isolated from male Wistar rats and humans. Precipitation of oxalic acid with calcium in the kidneys was assumed to occur only at concentrationsmore » exceeding the thermodynamic solubility product for calcium oxalate. This solubility product can be affected by local concentrations of calcium and other ions that are expressed in the model using an ion activity product estimated from toxicity studies such that calcium oxalate precipitation would be minimal at dietary exposures below the NOAEL for kidney toxicity in the sensitive male Wistar rat. The resulting integrated PBPK predicts that bolus oral or dietary exposures to ethylene glycol would result in typically 1.4-1.6-fold higher peak oxalate levels and 1.6-2-fold higher AUC's for calcium oxalate in kidneys of humans as compared with comparably exposed male Wistar rats over a dose range of 1-1000 mg/kg. The converse (male Wistar rats predicted to have greater oxalate levels in the kidneys than humans) was found for inhalation exposures although no accumulation of calcium oxalate is predicted to occur until exposures are well in excess of the theoretical saturated vapor concentration of 200 mg/m{sup 3}. While the current model is capable of such cross-species, dose, and route-of-exposure comparisons, it also highlights several areas of potential research that will improve confidence in such predictions, especially at low doses relevant for most human exposures.« less

Reliability and Validity of a Brief Questionnaire to Assess Calcium Intake in Female Collegiate Athletes

PubMed Central

Ward, Kenneth D.; Hunt, Kami Mays; Berg, Melanie Burstyne; Slawson, Deborah A.; Vukadinovich, Christopher M.; McClanahan, Barbara S.; Clemens, Linda H.

2016-01-01

Calcium intake often is inadequate in female collegiate athletes, increasing the risk for training injuries and future osteoporosis. Thus, a brief and accurate assessment tool to quickly measure calcium intake in athletes is needed. We evaluated the reliability and validity, compared to 6 days of diet records (DRs), of the Rapid Assessment Method (RAM), a self-administered calcium checklist (14). Seventy-six female collegiate athletes (mean age = 18.8 yrs, range = 17–21; 97% Caucasian) were recruited from basketball, cross-country, field hockey, soccer, and volleyball teams. Athletes completed a RAM at the start of the training season to assess calcium intake during the past week. Two weeks later, a second RAM was completed to assess reliability, and athletes began 6 days of diet records (DRs) collection. At completion of DRs, athletes completed a final RAM, corresponding to the same time period as DRs, to assess agreement between the 2 instruments. The RAM demonstrated adequate test-retest reliability over 2 weeks (n = 56; Intraclass correlation [ICC] = .54, p < .0001) and adequate agreement with DRs (n = 34; ICC = .41, p = .0067). Calcium intake was below recommended levels, and mean estimates did not differ significantly on the RAM (823 ± 387 mg/d) and DRs (822 ± 330 mg/d; p = .988). Adequacy of calcium intake from both DRs and the RAM was classified as “inadequate” (<1000 mg/d) and “adequate” (≥1000 mg/d). Agreement between the RAM and DRs for adequacy classification was fair (ICC = .30, p = .042), with the RAM identifying 84% of athletes judged to have inadequate calcium intake based on DRs. The RAM briefly and accurately estimates calcium intake in female collegiate athletes compared to DRs. PMID:15118194

Defects in antioxidant defense and calcium transport in the epidermis of xeroderma pigmentosum patients.

PubMed

Schallreuter, K U; Pittelkow, M R; Wood, J M

1991-01-01

A comparative study of the antioxidant enzymes superoxide dismutase, catalase, glutathione reductase and thioredoxin reductase was undertaken in two families with xeroderma pigmentosum (XP) and in healthy controls of corresponding skin phototypes. Epidermal blister roofs obtained from the XP patients revealed significant decreases in catalase, thioredoxin reductase, and superoxide dismutase, but glutathione reductase was unaffected. In addition, keratinocytes established from XP patients contained a significantly higher than normal intracellular calcium concentration compared with control cells from a corresponding skin type. Keratinocytes established from an XP obligate heterozygote revealed intermediate levels of calcium between XP homozygotes and controls. Previously high intracellular calcium has been shown to compromise the redox status of keratinocytes by allosteric inhibition of the thioredoxin reductase/thioredoxin electron transfer system. In XP homozygous keratinocytes from sun-exposed epidermis, the intracellular concentration of reduced thioredoxin was decreased to 50% compared with these cells from unexposed skin. Taken together, the results from this study indicate that the epidermis in XP patients lacks effective defense against free radicals and peroxides. In addition to the well-established defect in the normal rates of unscheduled DNA repair, these findings provide an even better explanation for the multiple cutaneous neoplasms in these patients.

The Association of Calcium Supplementation and Incident Cardiovascular Events in the Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Hsu, F.C.; de Boer, I.H.; Ix, J.H.; Siscovick, D.; Szklo, M.; Burke, G.L.; Frazier-Wood, A.C.; Herrington, D.M.

2016-01-01

Background and Aims Many US adults use calcium supplements to address inadequate dietary intake and improve bone health. However, recent reports have suggested that use of calcium supplements may elevate cardiovascular disease (CVD) risk. In this study, we examined associations between baseline calcium supplement use and incident myocardial infarction (MI) (n=208 events) and CVD events (n=641 events) over 10.3 years in men and women from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort (n=6,236), with dietary calcium intake at baseline also examined as a supplementary objective. Methods and Results Using Cox proportional hazards models, no compelling associations between calcium intake from supplements or diet and incident CVD events were observed upon multivariate adjustment for potential confounders. An association with lower MI risk was observed comparing those with low levels of calcium supplement use (1-499 mg) to those using no calcium supplements (hazard ratio 0.69, 95% CI 0.48, 0.98, p=0.039). Relationships were homogeneous by gender, race/ethnicity, or chronic kidney disease. Results were also similar when the analysis was limited to postmenopausal women only. Conclusion Analysis of incident MI and CVD events in the MESA cohort does not support a substantial association of calcium supplement use with negative cardiovascular outcomes. PMID:27514606

Calcium silicate-based drug delivery systems.

PubMed

Zhu, Ying-Jie; Guo, Xiao-Xuan; Sham, Tsun-Kong

2017-02-01

Compared with other inorganic materials such as silica, metal oxides, noble metals and carbon, calcium silicate-based materials, especially nanostructured calcium silicate materials, have high biocompatibility, bioactivity and biodegradability, high specific surface area, nanoporous/hollow structure, high drug-loading capacity, pH-responsive drug release behavior and desirable drug release properties, and thus they are promising for the application in drug delivery. Calcium silicate-based drug delivery systems have a long drug-release time, which can significantly prolong the therapeutic effect of drugs. Another advantage of calcium silicate-based drug delivery systems is their pH-responsive drug release property, which can act as an ideal platform for targeted drug delivery. Areas covered: In recent years, studies have been carried out on calcium silicate-based drug delivery systems, and important results and insights have been documented. This article is not intended to offer a comprehensive review on the research on calcium silicate-based drug delivery systems, but presents some examples reported in the literature, and includes new insights obtained by tracking the interactions between drug molecules and calcium silicate carriers on the molecular level using the synchrotron-based X-ray spectroscopy. Expert opinion: Finally, our opinions on calcium silicate-based drug delivery systems are provided, and several research directions for the future studies are proposed.

Viburnum opulus: could it be a new alternative, such as lemon juice, to pharmacological therapy in hypocitraturic stone patients?

PubMed

Tuglu, Devrim; Yılmaz, Erdal; Yuvanc, Ercan; Erguder, Imge; Kisa, Ucler; Bal, Fatih; Batislam, Ertan

2014-12-30

Citrate, potassium, and calcium levels in Viburnum opulus (V. opulus) and lemon juice were compared to evaluate the usability of V. opulus in mild to moderate level hypocitraturic stone disease. V. opulus and lemon fruits were squeezed in a blender and 10 samples of each of 100 ml were prepared. Citrate, calcium, sodium, potassium, magnesium, and pH levels in these samples were examined. Potassium was found to be statistically significantly higher in V. opulus than that in lemon juice (p = 0.006) whereas sodium (p = 0.004) and calcium (p = 0.008) were found to be lower. There was no difference between them in terms of the amount of magnesium and citrate. Because V. opulus contains citrate as high as lemon juice does and it is a potassium-rich and calciumand sodium-poor fluid, it can be an alternative to pharmaceutical treatment in mild-to-moderate degree hypocitraturic stone patients. These findings should be supported with clinical studies.

Dietary Calcium Intake, Serum Calcium Level, and their Association with Preeclampsia in Rural North India

PubMed Central

Gupta, Anant; Kant, Shashi; Pandav, Chandrakant S.; Gupta, Sanjeev K.; Rai, Sanjay K.; Misra, Puneet

2016-01-01

Background: Preeclampsia in pregnancy has been shown to be associated with low serum calcium level. Though the evidence is abundant, it is equivocal. Objectives: The study aimed to estimate the dietary calcium intake and serum calcium status among pregnant women, and to document the association of the dietary calcium intake and serum calcium status with incidence of preeclampsia in the 3rd trimester of pregnancy. Materials and Methods: A community-based cross-sectional study was conducted in the Health and Demographic Surveillance System (HDSS) site, Ballabgarh, Haryana, India. All pregnant women between 28 weeks and 36 weeks of gestation were interviewed. A semi-structured interview schedule and a 24-h dietary recall questionnaire were administered to assess the dietary calcium intake. AutoAnalyser (Biolis 24i) was used for measuring serum calcium. Results: We enrolled 217 pregnant women. The mean [standard deviation (SD)] dietary calcium intake was 858 (377) mg/day. The mean (SD) serum calcium level was 9.6 mg/dL (0.56). Incidence of preeclampsia was 13.4%. Preeclampsia was not associated with hypocalcemia [odds ratio (OR) = 1.2 95% confidence interval (CI); 0.27-3.98]. Conclusion: The majority of pregnant women had inadequate dietary calcium intake. The prevalence of hypocalcemia was low. Low serum calcium level was not associated with preeclampsia. Calcium supplementation may not reduce preeclampsia in this population. PMID:27385877

An iPTH based protocol for the prevention and treatment of symptomatic hypocalcemia after thyroidectomy

PubMed Central

Carter, Yvette; Chen, Herbert; Sippel, Rebecca S.

2013-01-01

Background Symptomatic hypocalcemia after thyroidectomy is a barrier to same day surgery, and the cause of ER visits. A standard protocol of calcium and vitamin D supplementation, dependent on intact parathyroid hormone (iPTH) levels, can address this issue. How effective is it? When does it fail? Methods We performed a retrospective review of the prospective Thyroid Database from January 2006 to December 2010. 620 patients underwent completion (CT) or total thyroidectomy (TT), and followed our post-operative protocol of calcium carbonate administration for iPTH levels ≥10pg/ml and calcium carbonate and 0.25μg calcitriol BID for iPTH <10pg/ml. Calcium and iPTH values, pathology and medication, were compared to evaluate protocol efficacy. A p value <0.05 was considered statistically significant. Results Using the protocol, sixty-one (10.2%) patients were chemically hypocalcemic but never developed symptoms and twenty-four (3.9%) patients developed breakthrough symptomatic hypocalcemia. The symptomatic (SX) and asymptomatic (ASX) groups were similar with regard to gender, cancer diagnosis, and pre-operative calcium and iPTH. The symptomatic group was significantly younger (39.6 ± 2.8 vs. 49 ± 0.6 years, p=0.01), with lower post-operative iPTH levels. 33% (n=8) of SX patients had an iPTH ≤5 pg/ml vs. only 6% (n=37) of ASX patients. While the majority of patients with a PTH <5 pg/ml were asymptomatic, 62.5% (n=5) of SX patients with iPTH levels ≤5 pg/ml, required an increased in calcitriol dose to achieve both biochemical correction and symptom relief. Conclusion Prophylactic calcium and vitamin D supplementation based on post-operative iPTH levels can minimize symptomatic hypocalcemia after thyroidectomy. An iPTH ≤ 5pg/ml may warrant higher initial doses of calcitriol in order to prevent symptoms. PMID:24144426

Association of Genetic Variants Related to Serum Calcium Levels With Coronary Artery Disease and Myocardial Infarction.

PubMed

Larsson, Susanna C; Burgess, Stephen; Michaëlsson, Karl

2017-07-25

Serum calcium has been associated with cardiovascular disease in observational studies and evidence from randomized clinical trials indicates that calcium supplementation, which raises serum calcium levels, may increase the risk of cardiovascular events, particularly myocardial infarction. To evaluate the potential causal association between genetic variants related to elevated serum calcium levels and risk of coronary artery disease (CAD) and myocardial infarction using mendelian randomization. The analyses were performed using summary statistics obtained for single-nucleotide polymorphisms (SNPs) identified from a genome-wide association meta-analysis of serum calcium levels (N = up to 61 079 individuals) and from the Coronary Artery Disease Genome-wide Replication and Meta-analysis Plus the Coronary Artery Disease Genetics (CardiogramplusC4D) consortium's 1000 genomes-based genome-wide association meta-analysis (N = up to 184 305 individuals) that included cases (individuals with CAD and myocardial infarction) and noncases, with baseline data collected from 1948 and populations derived from across the globe. The association of each SNP with CAD and myocardial infarction was weighted by its association with serum calcium, and estimates were combined using an inverse-variance weighted meta-analysis. Genetic risk score based on genetic variants related to elevated serum calcium levels. Co-primary outcomes were the odds of CAD and myocardial infarction. Among the mendelian randomized analytic sample of 184 305 individuals (60 801 CAD cases [approximately 70% with myocardial infarction] and 123 504 noncases), the 6 SNPs related to serum calcium levels and without pleiotropic associations with potential confounders were estimated to explain about 0.8% of the variation in serum calcium levels. In the inverse-variance weighted meta-analysis (combining the estimates of the 6 SNPs), the odds ratios per 0.5-mg/dL increase (about 1 SD) in genetically predicted serum calcium levels were 1.25 (95% CI, 1.08-1.45; P = .003) for CAD and 1.24 (95% CI, 1.05-1.46; P = .009) for myocardial infarction. A genetic predisposition to higher serum calcium levels was associated with increased risk of CAD and myocardial infarction. Whether the risk of CAD associated with lifelong genetic exposure to increased serum calcium levels can be translated to a risk associated with short-term to medium-term calcium supplementation is unknown.

Correlation of Salivary Statherin and Calcium Levels with Dental Calculus Formation: A Preliminary Study.

PubMed

Pateel, Deepak Gowda Sadashivappa; Gunjal, Shilpa; Math, Swarna Y; Murugeshappa, Devarasa Giriyapura; Nair, Sreejith Muraleedharan

2017-01-01

Salivary constituents have a wide range of functions including oral calcium homeostasis. Salivary proteins such as statherin inhibit crystal growth of calcium phosphate in supersaturated solutions and interact with several oral bacteria to adsorb on hydroxyapatite. Concurrently, saliva, which is supersaturated with respect to calcium phosphates, is the driving force for plaque mineralization and formation of calculus. Thus, the aim of the present study was to estimate and correlate salivary statherin and calcium concentration to the dental calculus formation. A cross-sectional study was conducted to assess the relationship between salivary statherin, calcium, and dental calculus among 70 subjects, aged 20-55 years. Subjects were divided into 3 groups based on the calculus scores as interpreted by Calculus Index which was followed by collection of whole saliva using Super•SAL™. Salivary calcium levels were assessed by calorimetric method using Calcium Assay kit (Cayman Chemical, Michigan, USA) and statherin levels by using ELISA Kit (Cusabio Biotech). Statherin levels showed a weak negative correlation with the calcium levels and with calculus formation. The mean salivary statherin and calcium concentration were found to be 0.96  μ g/ml and 3.87 mg/ml, respectively. Salivary statherin levels differed significantly among the three groups ( p < 0.05). Our preliminary data indicates that statherin could possibly play a role in the formation of dental calculus.

A clinical pathway for the postoperative management of hypocalcemia after pediatric thyroidectomy reduces blood draws.

PubMed

Patel, Neha A; Bly, Randall A; Adams, Seth; Carlin, Kristen; Parikh, Sanjay R; Dahl, John P; Manning, Scott

2018-02-01

Postoperative calcium management is challenging following pediatric thyroidectomy given potential limitations in self-reporting symptoms and compliance with phlebotomy. A protocol was created at our tertiary children's institution utilizing intraoperative parathyroid hormone (PTH) levels to guide electrolyte management during hospitalization. The objective of this study was to determine the effect of a new thyroidectomy postoperative management protocol on two primary outcomes: (1) the number of postoperative calcium blood draws and (2) the length of hospital stay. Institutional review board approved retrospective study (2010-2016). Consecutive pediatric total thyroidectomy and completion thyroidectomy ± neck dissection cases from 1/1/2010 through 8/5/2016 at a single tertiary children's institution were retrospectively reviewed before and after initiation of a new management protocol. All cases after 2/1/2014 comprised the experimental group (post-protocol implementation). The pre-protocol control group consisted of cases prior to 2/1/2014. Multivariable linear and Poisson regression models were used to compare the control and experimental groups for outcome measure of number of calcium lab draws and hospital length of stay. 53 patients were included (n = 23, control group; n = 30 experimental group). The median age was 15 years. 41 patients (77.4%) were female. Postoperative calcium draws decreased from a mean of 5.2 to 3.6 per day post-protocol implementation (Rate Ratio = 0.70, p < .001), adjusting for covariates. The mean number of total inpatient calcium draws before protocol initiation was 13.3 (±13.20) compared to 7.2 (±4.25) in the post-protocol implementation group. Length of stay was 2.1 days in the control group and 1.8 days post-protocol implementation (p = .29). Patients who underwent concurrent neck dissection had a longer mean length of stay of 2.32 days compared to 1.66 days in those patients who did not undergo a neck dissection (p = .02). Hypocalcemia was also associated with a longer mean length of stay of 2.41 days compared to 1.60 days in patients who did not develop hypocalcemia (p < .01). The number of calcium blood draws was significantly reduced after introduction of a standardized protocol based on intraoperative PTH levels. The hospital length of stay did not change. Adoption of a standardized postoperative protocol based on intraoperative PTH levels may reduce the number of blood draws in children undergoing thyroidectomy. Copyright © 2017 Elsevier B.V. All rights reserved.

Loperamide: A positive modulator for store-operated calcium channels?

PubMed Central

Harper, Jacquie L.; Shin, Yangmee; Daly, John W.

1997-01-01

The depletion of inositol trisphosphate-sensitive intracellular pools of calcium causes activation of store-operated calcium (SOC) channels. Loperamide at 10–30 μM has no effect on intracellular calcium levels alone, but augments calcium levels in cultured cells when SOC channels have been activated. In HL-60 leukemic cells, the apparent positive modulatory effect of loperamide on SOC channels occurs when these channels have been activated after ATP, thapsigargin, or ionomycin-elicited depletion of calcium from intracellular storage sites. Loperamide has no effect when levels of intracellular calcium are elevated through a mechanism not involving SOC channels by using sphingosine. Loperamide caused augmentation of intracellular calcium levels after activation of SOC channels in NIH 3T3 fibroblasts, astrocytoma 1321N cells, smooth muscle DDT-MF2 cells, RBL-2H3 mast cells, and pituitary GH4C1 cells. Only in astrocytoma cells did loperamide cause an elevation in intracellular calcium in the absence of activation of SOC channels. The augmentation of intracellular calcium elicited by loperamide in cultured cells was dependent on extracellular calcium and was somewhat resistant to agents (SKF 96365, miconazole, clotrimazole, nitrendipine, and trifluoperazine) that in the absence of loperamide effectively blocked SOC channels. It appears that loperamide augments influx of calcium through activated SOC channels. PMID:9405713

Bone turnover, calcium homeostasis, and vitamin D status in Danish vegans.

PubMed

Hansen, Tue H; Madsen, Marie T B; Jørgensen, Niklas R; Cohen, Arieh S; Hansen, Torben; Vestergaard, Henrik; Pedersen, Oluf; Allin, Kristine H

2018-01-23

A vegan diet has been associated with increased bone fracture risk, but the physiology linking nutritional exposure to bone metabolism has only been partially elucidated. This study investigated whether a vegan diet is associated with increased bone turnover and altered calcium homeostasis due to insufficient intake of calcium and vitamin D. Fractionated and total 25-hydroxyvitamin D (25(OH)-D), parathyroid hormone (PTH), calcium, and four bone turnover markers (osteocalcin, N-terminal propeptide of type I procollagen (PINP), bone-specific alkaline phosphatase (BAP), and C-terminal telopeptide of type I collagen (CTX)) were measured in serum from 78 vegans and 77 omnivores. When adjusting for seasonality and constitutional covariates (age, sex, and body fat percentage) vegans had higher concentrations of PINP (32 [95% CI: 7, 64]%, P = 0.01) and BAP (58 [95% CI: 27, 97]%, P < 0.001) compared to omnivores, whereas CTX (30 [95% CI: -1, 72]%, P = 0.06) and osteocalcin (21.8 [95% CI: -9.3, 63.7]%, P = 0.2) concentrations did not differ between the two groups. Vegans had higher serum PTH concentration (38 [95% CI: 19, 60]%; P < 0.001) and lower 25(OH)-D serum concentration (-33 [95% CI: -45, -19]%; P < 0.001), but similar serum calcium concentration (-1 [95% CI: -3, 1]%, P = 0.18 compared to omnivores. Vegans have higher levels of circulating bone turnover markers compared to omnivores, which may in the long-term lead to poorer bone health. Differences in dietary habits including intake of vitamin D and calcium may, at least partly, explain the observed differences.

Plasma oxalic acid and calcium levels in oxalate poisoning

PubMed Central

Zarembski, P. M.; Hodgkinson, A.

1967-01-01

Observations are reported on five cases of suicide or attempted suicide by poisoning with oxalic acid or ethylene glycol. Elevated oxalic acid levels were observed in the plasma, stomach contents, and a number of tissues. Raised oxalic acid levels in plasma were associated with reduced total and ultrafilterable calcium levels. It is suggested that the reduction in plasma total calcium level is due mainly to the deposition of calcium oxalate in the soft tissues, but inhibition of the parathyroid glands may be a contributory factor. Microscopic examination of various tissues indicated that oxalic acid is deposited in the tissues in two forms: (1) crystalline calcium oxalate dihydrate in the kidney and (2) a non-crystalline complex of calcium oxalate and lipid in liver and other tissues. PMID:5602563

Towards bio monitoring of toxic (lead) and essential elements in whole blood from 1- to 72-month old children: a cross-sectional study.

PubMed

Kang-Sheng, Liu; Xiao-Dong, Mao; Juan, Shi; Chun-Fan, Dai; Pingqing, Gu

2015-06-01

Minerals such as zinc, copper, selenium, calcium, and magnesium are essential for normal human development and functioning of the body. They have been found to play important roles in immuno-physiologic functions. The study is to evaluate the distribution and correlation of nonessential (lead) and essential elements in whole blood from 1- to 72-month old children. The cross-sectional study was performed in 1551 children. Six element concentrations, including copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), iron (Fe) and lead (Pb) in the blood were determined by atomic absorption spectrometry. Distributions and correlations of trace elements in different age groups were analyzed and compared. A Pearson correlation controlled for age and gender was used to assess the relationship of non essential (lead) and essential elements. Levels of copper and magnesium were 18.09 ± 4.42 µmol/L and 1.42 ± 0.12 mmol/L, respectively. 6.04% of all children showed copper levels below the normal threshold, the levels of Magnesium were stable in different age groups. Though the overall mean blood zinc and iron concentrations (61.19 ± 11.30 µmol/L and 8.24 ± 0.59 mmol/L, respectively) gradually increased with age and the overall deficiency levels (24.1% and 36.0%, respectively) decreased with age, zinc and iron deficiencies were still very stable. Controlling for gender and age, significant positive correlations were found when comparing copper to zinc, calcium, magnesium, and iron ((r = 0.333, 0.241, 0.417, 0.314 ,p < 0.01); zinc to magnesium and iron (r = 0.440, 0.497p < 0.01); and magnesium to Calcium and iron (r = 0.349, 0.645, p < 0.01). The overall mean blood lead levels (41.16 ± 16.10) were relatively unstable among different age groups. The prevalence of lead intoxication in all children was 1.3% .Calcium levels decreased gradually with age, with an overall concentration of 1.78 ± 0.13 mmol/L. Significant negative correlations were also noted between Pb and Zn, Fe (r = -0.179, -0.124.p < 0.01) .The importance of calcium deficiency and supplementation is well realized, but the severity of iron and zinc deficiency is not well recorded. The degree of lead intoxication in all the children studied was low; The established reference intervals for Cu, Zn, Ca and Mg provide an important guidance for the reasonable supplementation of essential elements during different age groups.

Demographic, Dietary, and Urinary Factors and 24-h Urinary Calcium Excretion

PubMed Central

Curhan, Gary C.

2009-01-01

Background and objectives: Higher urinary calcium is a risk factor for nephrolithiasis. This study delineated associations between demographic, dietary, and urinary factors and 24-h urinary calcium. Design, setting, participants, & measurements: Cross-sectional studies were conducted of 2201 stone formers (SF) and 1167 nonstone formers (NSF) in the Health Professionals Follow-up Study (men) and Nurses' Health Studies I and II (older and younger women). Results: Median urinary calcium was 182 mg/d in men, 182 mg/d in older women, and 192 mg/d in younger women. Compared with NSF, urinary calcium as a fraction of calcium intake was 33 to 38% higher in SF (P values ≤0.01). In regression analyses, participants were combined because associations with urinary calcium were similar in each cohort and in SF and NSF. After multivariate adjustment, participants in the highest quartile of calcium intake excreted 18 mg/d more urinary calcium than those in the lowest (P trend =0.01). Caffeine and family history of nephrolithiasis were positively associated, whereas urinary potassium, thiazides, gout, and age were inversely associated, with urinary calcium. After multivariate adjustment, participants in the highest quartiles of urinary magnesium, sodium, sulfate, citrate, phosphorus, and volume excreted 71 mg/d, 37 mg/d, 44 mg/d, 61 mg/d, 37 mg/d, and 24 mg/d more urinary calcium, respectively, than participants in the lowest (P values trend ≤0.01). Conclusions: Intestinal calcium absorption and/or negative calcium balance is greater in SF than NSF. Higher calcium intakes at levels typically observed in free-living individuals are associated with only small increases in urinary calcium. PMID:19820135

Hypervitaminosis A is prevalent in children with CKD and contributes to hypercalcemia.

PubMed

Manickavasagar, Baheerathi; McArdle, Andrew J; Yadav, Pallavi; Shaw, Vanessa; Dixon, Marjorie; Blomhoff, Rune; Connor, Graeme O'; Rees, Lesley; Ledermann, Sarah; Van't Hoff, William; Shroff, Rukshana

2015-02-01

Vitamin A accumulates in renal failure, but the prevalence of hypervitaminosis A in children with predialysis chronic kidney disease (CKD) is not known. Hypervitaminosis A has been associated with hypercalcemia. In this study we compared dietary vitamin A intake with serum retinoid levels and their associations with hypercalcemia. We studied the relationship between vitamin A intake, serum retinoid levels, and serum calcium in 105 children with CKD stages 2-5 on dialysis and posttransplant. Serum retinoid measures included retinol (ROH), its active retinoic acid (RA) metabolites [all-trans RA (at-RA) and 13-cis RA] and carrier proteins [retinol-binding protein-4 (RBP4) and transthyretin (TTR)]. Dietary vitamin A intake was assessed using a food diary. Twenty-five children were in CKD 2-3, 35 in CKD 4-5, 23 on dialysis and 22 posttransplant; 53 % had vitamin A intake above the Reference Nutrient Intake (RNI) value. Children receiving supplemental feeds compared with diet alone had higher vitamin A intake (p = 0.02) and higher serum ROH (p < 0.001). Notably, increased ROH was seen as early as CKD stage 2. For every 10 ml/min/1.73 m(2) fall in estimated glomerular filtration rate (eGFR), there was a 13 % increase in ROH. RBP4 levels were increased in CKD 3-5 and dialysis patients. The lowest ratios of ROH:RBP4 were seen in dialysis compared with CKD 2-3 (p = 0.03), suggesting a relative increase in circulating RBP4. Serum ROH, RBP4 and at-RA were associated with serum calcium. On multivariable analysis RBP4 levels and alfacalcidol dose were significant predictors of serum calcium (model R (2) 32 %) in dialysis patients. Hypervitaminosis A is seen in early CKD, with highest levels in children on supplemental feeds compared with diet alone. Serum retinoid levels significantly predict hypercalcemia.

Evaluation of serum 25-hydroxyvitamin D levels in calcific rheumatic mitral stenosis- A cross sectional study.

PubMed

Yusuf, Jamal; P, Jothinath; Mukhopadhyay, Saibal; Vignesh, Vickram; Tyagi, Sanjay

Rheumatic mitral stenosis (RMS) is an autoimmune, progressive destructive valve disease occurring as a sequele of streptococcal infection. Epidemiological studies support an association of vitamin D deficiency with initial susceptibility and severity of autoimmune diseases. The aim of the present study was to assess serum level of 25 hydroxyvitamin D in subjects of RMS and assess if any correlation exists with serum levels of vitamin D and severity of disease along with calcification assessed semi-quantitatively by echocardiography by applying Wilkins score. Fifty five patients of RMS without any calcification of the valves (Group A) assessed by echocardiography along with fifty five patients of RMS with mild to moderately calcified valves (Group B, Wilkins calcium score 1 or 2) and 55 patients with severely calcified valves (Group C, Wilkins calcium score 3 or 4) were enrolled for the study. All subjects underwent clinical, echocardiographic, and biochemical evaluation. The total Wilkins score, Wilkins calcium score along with serum level of 25 hydroxyvitamin D was evaluated in all the patients. The median serum level of 25 hydroxyvitamin D was significantly lower in Group B (20.4ng/ml, p<0.001) and group C (11.4ng/ml, p<0.001) compared to Group A patients (27.9ng/ml). Similarly serum level of 25 hydroxyvitamin D in Group C patients were significantly less than Group B patients (p<0.001). A significant inverse correlation was identified between serum level of 25 hydroxyvitamin D and total Wilkins score (r=-0.65, p<0.001) as well as Wilkins calcium score (r=-0.69, p<0.001). But no correlation was identified between 25 hydroxyvitamin D levels and other echocardiographic parameters of RMS. Our study showed a significantly lower level of 25 hydroxyvitamin D in subjects of RMS with severely damaged and calcified valves as compared to those with less severely damaged non-calcified valves and it correlated with both Wilkins score and Wilkins calcification score. Thus a link may exist between vitamin D deficiency (an immunomodulator) and severity of autoimmune injury on the valves. Copyright © 2017. Published by Elsevier B.V.

A Neuron-Based Screening Platform for Optimizing Genetically-Encoded Calcium Indicators

PubMed Central

Schreiter, Eric R.; Hasseman, Jeremy P.; Tsegaye, Getahun; Fosque, Benjamin F.; Behnam, Reza; Shields, Brenda C.; Ramirez, Melissa; Kimmel, Bruce E.; Kerr, Rex A.; Jayaraman, Vivek; Looger, Loren L.; Svoboda, Karel; Kim, Douglas S.

2013-01-01

Fluorescent protein-based sensors for detecting neuronal activity have been developed largely based on non-neuronal screening systems. However, the dynamics of neuronal state variables (e.g., voltage, calcium, etc.) are typically very rapid compared to those of non-excitable cells. We developed an electrical stimulation and fluorescence imaging platform based on dissociated rat primary neuronal cultures. We describe its use in testing genetically-encoded calcium indicators (GECIs). Efficient neuronal GECI expression was achieved using lentiviruses containing a neuronal-selective gene promoter. Action potentials (APs) and thus neuronal calcium levels were quantitatively controlled by electrical field stimulation, and fluorescence images were recorded. Images were segmented to extract fluorescence signals corresponding to individual GECI-expressing neurons, which improved sensitivity over full-field measurements. We demonstrate the superiority of screening GECIs in neurons compared with solution measurements. Neuronal screening was useful for efficient identification of variants with both improved response kinetics and high signal amplitudes. This platform can be used to screen many types of sensors with cellular resolution under realistic conditions where neuronal state variables are in relevant ranges with respect to timing and amplitude. PMID:24155972

Reduced expression of the Ca(2+) transporter protein PMCA2 slows Ca(2+) dynamics in mouse cerebellar Purkinje neurones and alters the precision of motor coordination.

PubMed

Empson, Ruth M; Turner, Paul R; Nagaraja, Raghavendra Y; Beesley, Philip W; Knöpfel, Thomas

2010-03-15

Cerebellar Purkinje neurones (PNs) express high levels of the plasma membrane calcium ATPase, PMCA2, a transporter protein critical for the clearance of calcium from excitable cells. Genetic deletion of one PMCA2 encoding gene in heterozygous PMCA2 knock-out (PMCA2(+/-) mice enabled us to determine how PMCA2 influences PN calcium regulation without the complication of the severe morphological changes associated with complete PMCA2 knock-out (PMCA2(-/-) in these cells. The PMCA2(+/-) cerebellum expressed half the normal levels of PMCA2 and this nearly doubled the time taken for PN dendritic calcium transients to recover (mean fast and slow recovery times increased from 70 ms to 110 ms and from 600 ms to 1100 ms). The slower calcium recovery had distinct consequences for PMCA2(+/-) PN physiology. The PNs exhibited weaker climbing fibre responses, prolonged outward Ca(2+)-dependent K(+) current (mean fast and slow recovery times increased from 136 ms to 192 ms and from 595 ms to 1423 ms) and a slower mean frequency of action potential firing (7.4 Hz compared with 15.8 Hz). Our findings were consistent with prolonged calcium accumulation in the cytosol of PMCA2(+/-) Purkinje neurones. Although PMCA2(+/-) mice exhibited outwardly normal behaviour and little change in their gait pattern, when challenged to run on a narrow beam they exhibited clear deficits in hindlimb coordination. Training improved the motor performance of both PMCA2(+/-) and wild-type mice, although PMCA2(+/-) mice were always impaired. We conclude that reduced calcium clearance perturbs calcium dynamics in PN dendrites and that this is sufficient to disrupt the accuracy of cerebellar processing and motor coordination.

Calcium, zinc, and iron bioavailabilities from a commercial human milk fortifier: a comparison study.

PubMed

Etcheverry, P; Wallingford, J C; Miller, D D; Glahn, R P

2004-11-01

Adding human milk fortifiers (HMF) to human milk (HM) is one way of overcoming the nutrient deficits found in the latter. In this study, the bioavailabilities of calcium, zinc, and iron in S-26/SMA HMF added to HM were compared with those in HM fortified with various bovine milk proteins: alpha-lactalbumin, colostrum, caseinate, casein phosphopeptides, and whey protein concentrate. The bioavailability of each mineral was assessed using an in vitro digestion/Caco-2 cell culture model. Calcium and zinc uptake by the cells was traced with radioisotopes; iron uptake was assessed via cell ferritin levels. Samples were prepared on an equal protein content basis and with added calcium, but no zinc or iron was added. Results revealed that calcium uptake from HM + S-26/SMA was not different from any of the HM fortified with the bovine milk proteins, except for unfortified HM and HM + colostrum in which calcium uptake was significantly lower (-89 and -38%, respectively). Uptake of zinc and iron were significantly higher for HM + S-26/SMA than for the other HM + fortifiers.

Hypervitaminosis D and Metastatic Calcification in a Colony of Inbred Strain 13 Guinea Pigs, Cavia porcellus.

PubMed

Holcombe, H; Parry, N M; Rick, M; Brown, D E; Albers, T M; Refsal, K R; Morris, J; Kelly, R; Marko, S T

2015-07-01

A commercial diet fed to a colony of inbred strain 13 guinea pigs for approximately 6 weeks was subsequently recalled for excessive levels of vitamin D. Twenty-one of 62 animals exhibited clinical signs, including anorexia, lethargy, and poor body condition. Nine affected and 4 clinically normal animals were euthanized for further evaluation, including serum chemistry, urinalysis, and gross and/or histopathology. Macroscopic findings included white discoloration in multiple organs in 8 animals, and microscopic evaluation confirmed multiorgan mineralization in tissues from 7 animals. Serum 25-hydroxyvitamin D levels were elevated in 10 animals. Serum inorganic phosphorus and alkaline phosphatase levels were increased in all exposed animals; however, total calcium and ionized calcium levels were not significantly higher in exposed animals than in control strain 13 guinea pigs from a different institution. The data support a diagnosis of hypervitaminosis D with metastatic calcification. Following the diet recall, the remaining guinea pigs increased their food intake and regained body condition. Diagnostic testing of 8 animals euthanized approximately 3 months after returning to a normal diet demonstrated that serum parathyroid hormone remained significantly lower, and ionized calcium and ionized magnesium were significantly higher, in recovered animals compared to controls and exposed animals. These results indicate that diagnostic tests other than serum calcium are necessary for a diagnosis of hypervitaminosis D in guinea pigs. © The Author(s) 2014.

Effect of supplemental vitamin D and calcium on serum sclerostin levels.

PubMed

Dawson-Hughes, Bess; Harris, Susan S; Ceglia, Lisa; Palermo, Nancy J

2014-04-01

Serum sclerostin levels have been reported to be inversely associated with serum 25OHD levels, but the effect of vitamin D and calcium supplementation on serum sclerostin levels is unknown. This study was carried out to determine whether vitamin D and calcium supplementation altered serum sclerostin levels in healthy older adults. We measured serum sclerostin levels at baseline and after 2 years in 279 men and women who participated in a placebo-controlled vitamin D (700 IU/day) and calcium (500 mg/day) intervention trial carried out in men and women aged ≥65 years. Serum sclerostin levels were measured using the MesoScale Discovery chemiluminescence assay. In the men, sclerostin levels increased over 2 years by 4.11±1.81 ng/l (13.1%) in the vitamin D plus calcium-supplemented group and decreased by 3.16±1.78 ng/l (10.9%) in the placebo group (P=0.005 for difference in change). Adjustments for the season of measurement, baseline physical activity levels, baseline serum sclerostin levels, and total body bone mineral content did not substantially alter the changes. In the women, there was no significant group difference in change in serum sclerostin levels either before or after the above-mentioned adjustments. In both the sexes, vitamin D and calcium supplementation significantly increased serum ionized calcium levels and decreased parathyroid hormone levels. Men and women appear to have different serum sclerostin responses to vitamin D and calcium supplementation. The reason for this difference remains to be determined.

Collagen Peptides from Crucian Skin Improve Calcium Bioavailability and Structural Characterization by HPLC-ESI-MS/MS.

PubMed

Hou, Tao; Liu, Yanshuang; Guo, Danjun; Li, Bo; He, Hui

2017-10-11

The effects of collagen peptides (CPs), which are derived from crucian skin, were investigated in a retinoic acid-induced bone loss model. The level of serum bone alkaline phosphatase (BALP) in the model group (117.65 ± 4.66 units/L) was significantly higher than those of the other three groups (P < 0.05). After treatment with 600 and 1200 mg of CPs/kg, the level of BALP decreased to 85.26 ± 7.35 and 97.03 ± 7.21 units/L, respectively. After treatment with 600 mg of CPs/kg, the bone calcium content significantly increased by 22% (femur) and 12.38% (tibia) compared to those of the model group. In addition, the bone mineral density in the 600 mg of CPs/kg group was significantly higher (femur, 0.37 ± 0.02 g/cm 2 ; tibia, 0.33 ± 0.02 g/cm 2 ) than in the model group (femur, 0.26 ± 0.01 g/cm 2 ; tibia, 0.23 ± 0.02 g/cm 2 ). The morphology results indicated bone structure improved after the treatment with CPs. Structural characterization demonstrated that Glu, Lys, and Arg play important roles in binding calcium and promoting calcium uptake. Our results indicated that CPs could promote calcium uptake and regulate bone formation.

Induction of hypocalcemia by intracerebroventricular injection of calcitonin: evidence for control of blood calcium by the nervous system.

PubMed

Goltzman, D; Tannenbaum, G S

1987-07-21

Calcitonin (CT), when administered peripherally, is a potent hypocalcemic agent. This peptide can also exert a variety of profound effects through brain receptors after central injection. We examined the capacity of CT to alter plasma calcium of freely moving conscious rats after intracerebroventricular (i.c.v.) injection. A dose-dependent decrease in plasma calcium was seen after administration of 25 ng, 250 ng or 2500 ng of salmon calcitonin (sCT). The extent and duration of hypocalcemia after central injection was equal to, or greater than, that seen after giving the same doses of peptide intravenously (i.v.). Calcitonin gene-related peptide (CGRP), when administered centrally at a 50-fold molar excess, produced only a transient decrease in plasma calcium. No increase in plasma levels of sCT could be detected by RIA after i.c.v. injection, although measurable levels were obtained by i.v. injection. Centrally administered sCT did not appear to produce hypocalcemia by enhancing the release of endogenous rat CT. In contrast to the rise in rat immunoreactive parathyroid hormone (PTH) seen after i.v. injection of sCT, no significant elevation occurred after central administration of the peptide despite induction of comparable levels of hypocalcemia. Consequently, reduced PTH release may contribute to the central hypocalcemic action of CT. The results indicate that peptides acting through the brain CT receptor may modulate peripheral blood calcium.

Parallel Stochastic discrete event simulation of calcium dynamics in neuron.

PubMed

Ishlam Patoary, Mohammad Nazrul; Tropper, Carl; McDougal, Robert A; Zhongwei, Lin; Lytton, William W

2017-09-26

The intra-cellular calcium signaling pathways of a neuron depends on both biochemical reactions and diffusions. Some quasi-isolated compartments (e.g. spines) are so small and calcium concentrations are so low that one extra molecule diffusing in by chance can make a nontrivial difference in its concentration (percentage-wise). These rare events can affect dynamics discretely in such way that they cannot be evaluated by a deterministic simulation. Stochastic models of such a system provide a more detailed understanding of these systems than existing deterministic models because they capture their behavior at a molecular level. Our research focuses on the development of a high performance parallel discrete event simulation environment, Neuron Time Warp (NTW), which is intended for use in the parallel simulation of stochastic reaction-diffusion systems such as intra-calcium signaling. NTW is integrated with NEURON, a simulator which is widely used within the neuroscience community. We simulate two models, a calcium buffer and a calcium wave model. The calcium buffer model is employed in order to verify the correctness and performance of NTW by comparing it to a serial deterministic simulation in NEURON. We also derived a discrete event calcium wave model from a deterministic model using the stochastic IP3R structure.

Serum cation profile of broilers at various stages of exposure to deoxynivalenol.

PubMed

Yunus, Agha Waqar; Böhm, Josef

2013-05-01

The present experiment was carried out to investigate if levels of serum cations in broilers are modulated differently at various stages of exposure to deoxynivalenol (DON). Male broiler chicks at 7 days of age were fed a basal diet (0.27 mg of DON; 0.01 mg of zearalenone/kg), or either a low DON diet (1.68 mg of DON; 0.15 mg of zearalenone/kg) or a high DON diet (12.21 mg of DON; 1.09 mg of zearalenone/kg) produced using extracts from Fusarium graminearum cultures. Blood samples from the birds were collected during weeks 2, 4, and 5 of exposure. The high DON diet resulted in lower serum calcium levels compared to the basal diet at all the 3 sampling stages, while the low DON diet resulted in lower serum calcium levels only during weeks 2 and 5. Serum potassium levels were reduced under both the DON diets during weeks 2 and 5, while no diet-associated changes were found for serum levels of magnesium, sodium, and zinc. Under the present experimental conditions, the serum levels of calcium were consistently modulated in the broilers exposed to the DON-contaminated diets. The modulation of serum levels of potassium was, however, dependent upon the stage of exposure to DON.

Induction of endoplasmic reticulum calcium pump expression during early leukemic B cell differentiation.

PubMed

Aït Ghezali, Lamia; Arbabian, Atousa; Roudot, Hervé; Brouland, Jean-Philippe; Baran-Marszak, Fanny; Salvaris, Evelyn; Boyd, Andrew; Drexler, Hans G; Enyedi, Agnes; Letestu, Remi; Varin-Blank, Nadine; Papp, Bela

2017-06-26

Endoplasmic reticulum (ER) calcium storage and release play important roles in B lymphocyte maturation, survival, antigen-dependent cell activation and immunoglobulin synthesis. Calcium is accumulated in the endoplasmic reticulum (ER) by Sarco/Endoplasmic Reticulum Calcium ATPases (SERCA enzymes). Because lymphocyte function is critically dependent on SERCA activity, it is important to understand qualitative and quantitative changes of SERCA protein expression that occur during B lymphoid differentiation and leukemogenesis. In this work we investigated the modulation of SERCA expression during the pharmacologically induced differentiation of leukemic precursor B lymphoblast cell lines that carry the E2A-PBX1 fusion oncoprotein. Changes of SERCA levels during differentiation were determined and compared to those of established early B lymphoid differentiation markers. SERCA expression of the cells was compared to that of mature B cell lines as well, and the effect of the direct inhibition of SERCA-dependent calcium transport on the differentiation process was investigated. We show that E2A-PBX1 + leukemia cells simultaneously express SERCA2 and SERCA3-type calcium pumps; however, their SERCA3 expression is markedly inferior to that of mature B cells. Activation of protein kinase C enzymes by phorbol ester leads to phenotypic differentiation of the cells, and this is accompanied by the induction of SERCA3 expression. Direct pharmacological inhibition of SERCA-dependent calcium transport during phorbol ester treatment interferes with the differentiation process. These data show that the calcium pump composition of the ER is concurrent with increased SERCA3 expression during the differentiation of precursor B acute lymphoblastic leukemia cells, that a cross-talk exists between SERCA function and the control of differentiation, and that SERCA3 may constitute an interesting new marker for the study of early B cell phenotype.

Phosphate homeostasis in Bartter syndrome: a case-control study.

PubMed

Bettinelli, Alberto; Viganò, Cristina; Provero, Maria Cristina; Barretta, Francesco; Albisetti, Alessandra; Tedeschi, Silvana; Scicchitano, Barbara; Bianchetti, Mario G

2014-11-01

Bartter patients may be hypercalciuric. Additional abnormalities in the metabolism of calcium, phosphate, and calciotropic hormones have occasionally been reported. The metabolism of calcium, phosphate, and calciotropic hormones was investigated in 15 patients with Bartter syndrome and 15 healthy subjects. Compared to the controls, Bartter patients had significantly reduced plasma phosphate {mean [interquartile range]:1.29 [1.16-1.46] vs. 1.61 [1.54-1.67] mmol/L} and maximal tubular phosphate reabsorption (1.16 [1.00-1.35] vs. 1.41 [1.37-1.47] mmol/L) and significantly increased parathyroid hormone (PTH) level (6.1 [4.5-7.7] vs. 2.8 [2.2-4.4] pmol/L). However, patients and controls did not differ in blood calcium, 25-hydroxyvitamin D, alkaline phosphatase, and osteocalcin levels. In patients, an inverse correlation (P < 0.05) was noted between total plasma calcium or glomerular filtration rate and PTH concentration. A positive correlation was also noted between PTH and osteocalcin concentrations (P < 0.005), as well as between chloriduria or natriuria and phosphaturia (P < 0.001). No correlation was noted between calciuria and PTH concentration or between urinary or circulating phosphate and PTH. The results of this study demonstrate a tendency towards renal phosphate wasting and elevated circulating PTH levels in Bartter patients.

Protective effects of salivary factors in dental caries in diabetic patients of Pakistan.

PubMed

Jawed, Muhammad; Khan, Rashid N; Shahid, Syed M; Azhar, Abid

2012-01-01

Salivary factors have been studied for their effects on the process of dental caries in patients of diabetes mellitus type 2. In this study, protective role of salivary pH, salivary flow rate, and salivary calcium is assessed in the patients of diabetes mellitus type 2 with dental caries. The samples of saliva were collected from 400 patients of diabetes mellitus type 2 and 300 age- and sex- matched controls after getting informed consent. All the subjects were classified into four groups according to age. The severity of dental caries was counted by decayed, missed, and filled teeth (DMFT) score. The salivary pH, flow rate, and calcium levels were found to be low in patients as compared to controls. The levels of fasting blood sugar, HbA1c, and DMFT score were found to be significantly high in patients than controls. The glycemic factors were significantly correlated with salivary factors indicating their influence on progression of caries in diabetes. On the basis of findings, it is concluded that the suitable salivary pH and flow rate may be regarded as main protective factors against dental caries in diabetes. Optimum level of salivary calcium may be responsible for continuous supply of calcium to arrest the demineralization and help reduce the occurrence of dental caries.

Sensitive methods for the titrimetric micro-determination of biological calcium and magnesium

PubMed Central

Beale, R. N.; Bostrom, J. O.

1963-01-01

New reagents containing high concentrations of urea are developed for micro-titration of calcium and magnesium, with ethylenediamine tetra-acetic acid (E.D.T.A.) as titrant and Corinth Ca (Plasmocorinth B) as indicator. Magnesium is determined as the difference between calcium plus magnesium and calcium. Quantitative aspects are studied, and accurate titration of untreated serum or urine is believed to be possible; precision is satisfactory. The methods are simple, robust, and suitable for routine use. Normal ranges are established for serum from blood donors of each sex. The mean serum calcium level for women is found to be lower than for men, while the mean magnesium contents are approximately the same. The latter appear to be somewhat lower than values found by flame emission spectrophotometry; in very good agreement with a mean value for plasma obtained by flame absorption spectrophotometry; and intermediate when compared with the values obtained by two other titrimetric procedures. PMID:13969919

Strontium enhances osseointegration of calcium phosphate cement: a histomorphometric pilot study in ovariectomized rats.

PubMed

Baier, Martin; Staudt, Patric; Klein, Roman; Sommer, Ulrike; Wenz, Robert; Grafe, Ingo; Meeder, Peter Jürgen; Nawroth, Peter P; Kasperk, Christian

2013-06-07

Calcium phosphate cements are used frequently in orthopedic and dental surgeries. Strontium-containing drugs serve as systemic osteoblast-activating medication in various clinical settings promoting mechanical stability of the osteoporotic bone. Strontium-containing calcium phosphate cement (SPC) and calcium phosphate cement (CPC) were compared regarding their local and systemic effects on bone tissue in a standard animal model for osteoporotic bone. A bone defect was created in the distal femoral metaphysis of 60 ovariectomized Sprague-Dawley rats. CPC and SPC were used to fill the defects in 30 rats in each group. Local effects were assessed by histomorphometry at the implant site. Systemic effects were assessed by bone mineral density (BMD) measurements at the contralateral femur and the spine. Faster osseointegration and more new bone formation were found for SPC as compared to CPC implant sites. SPC implants exhibited more cracks than CPC implants, allowing more bone formation within the implant. Contralateral femur BMD and spine BMD did not differ significantly between the groups. The addition of strontium to calcium phosphate stimulates bone formation in and around the implant. Systemic release of strontium from the SPC implants did not lead to sufficiently high serum strontium levels to induce significant systemic effects on bone mass in this rat model.

Comparative Ultrastructure and Carbohydrate Composition of Gastroliths from Astacidae, Cambaridae and Parastacidae Freshwater Crayfish (Crustacea, Decapoda)

PubMed Central

Luquet, Gilles; Fernández, María S.; Badou, Aïcha; Guichard, Nathalie; Roy, Nathalie Le; Corneillat, Marion; Alcaraz, Gérard; Arias, José L.

2012-01-01

Crustaceans have to cyclically replace their rigid exoskeleton in order to grow.Most of them harden this skeleton by a calcification process. Some decapods (land crabs, lobsters and crayfish) elaborate calcium storage structures as a reservoir of calcium ions in their stomach wall, as so-called gastroliths. For a better understanding of the cyclic elaboration of these calcium deposits, we studied the ultrastructure of gastroliths from freshwater crayfish by using a combination of microscopic and physical techniques. Because sugars are also molecules putatively involved in the elaboration process of these biomineralizations, we also determined their carbohydrate composition. This study was performed in a comparative perspective on crayfish species belonging to the infra-order Astacidea (Decapoda, Malacostraca): three species from the Astacoidea superfamily and one species from the Parastacoidea superfamily. We observed that all the gastroliths exhibit a similar dense network of protein-chitin fibers, from macro- to nanoscale, within which calcium is precipitated as amorphous calcium carbonate. Nevertheless, they are not very similar at the molecular level, notably as regards their carbohydrate composition. Besides glucosamine, the basic carbohydrate component of chitin, we evidenced the presence of other sugars, some of which are species-specific like rhamnose and galacturonic acid whereas xylose and mannose could be linked to proteoglycan components. PMID:24970155

[The replacement therapy of rPTH(1-84) in established rat model of hypothyroidism].

PubMed

Ding, Zhiwei; Li, Tiancheng; Liu, Yuhe; Xiao, Shuifang

2015-12-01

To investigate the replacement therapy of rPTH(1-84) (recombinant human parathyroid hormone (1-84)) to hypothyroidism in established rat model. Rat model of hypothyroidism was established by resecting parathyroids. A total of 30 rats with removal of parathyroids were divided into 6 groups randomly, 5 in each group, and applied respectively with saline injection (negative control group), calcitriol treatment (positive control group) and quadripartite PTH administration with dose of 20, 40, 80 and 160 µg/kg (experimental groups). Saline and rPTH(1-84) were injected subcutaneously daily. Calcitriol was gavaged once a day. Sham-operation was conducted in 5 rats of negative control group. To verify the authenticity of the rat model with hypothyroidism, the serum was insolated centrifugally from rat blood that was obtained from angular vein at specific time to measure calcium and phosphorus concentration. Urine in 12 hours was collected by metabolic cages and the calcium concentration was measured. After 10-week drug treatment, the experiment was terminated and bilateral femoral bone and L2-5 lumbar vertebra were removed from rats. Bone mineral density (BMD)of bilateral femoral bone and lumbar vertebra was analyzed by dual X-ray absorptiometry (DXA). The concentration of bone alkaline phosphatase (BALP) in serum was determined by radioimmunoassay. The rat model with hypothyroidism was obtained by excising parathyroid gland and was verified by monitoring calcium and phosphorus concentration subsequently. Administration of rPTH(1-84) in the dose of 80 or 160 µg/kg made serum calcium and phosphorus back to normal levels, with no significant difference between the doses (P>0.05). The BMD in each group of rats with rPTH(1-84) administration was increased significantly (P<0.05). The levels of urinary calcium and serum BALP in rats of maximum rPTH(1-84) injection group (160 µg/kg) were higher than those of normal control group (P<0.05). The rats treated with calcitriol had normal calcium levels and showed the increase of BMD and phosphorus concentration compared with normal control group (P<0.05). The amount of urinary calcium also exceeded the other groups (P<0.05), but no with significant difference in BMD of bilateral femoral bone and lumbar vertebra between negative control group and normal control group (P>0.05). Calcium and phosphorus return to normal level by administration of rPTH(1-84) in the dose of 80 µg/kg or 160 µg/kg, with increase in BMD. Calcitriol can return the level of calcium to normal and increase BMD, but can not correspondingly decrease the phosphorus concentration and increase the excretion of calcium in urine.

Calcium distribution in Amoeba proteus

PubMed Central

1979-01-01

A preliminary investigation of the distribution of cellular calcium in Amoeba proteus was undertaken. Total cellular calcium under control conditions was found to be 4.59 mmol/kg of cells. When the external Ca++ concentration is increased from the control level of 0.03 to 20 mM, a net Ca++ influx results with a new steady-state cellular calcium level being achieved in integral of 3 h. At steady state the amount of calcium per unit weight of cells is higher than the amount of calcium per unit weight of external solution when the external concentration of Ca++ is below 10 mM. At external Ca++ concentrations above this level, total cellular calcium approaches the medium level of Ca++. Steady- state calcium exchange in Amoeba proteus was determined with 45Ca. There is an immediate and rapid exchange of integral of 0.84 mmol/kg of cells or 18% of the total cellular calcium with the labelled Ca++. Following this initial exchange, there was very little if any further exchange observed. Most of this exchanged calcium could be eliminated from the cell with 1 mM La+++, suggesting that the exchanged calcium is associated with the surface of the cell. Increase in either the external Ca++ concentration of pH raise the amount of exchangeable calcium associated with the cell. Calcium may be associated with the cell surface as a co-ion in the diffuse double layer or bound to fixed negative sites on the surface of the cell. If Ca++-binding sites do exist on the cell surface, there may be more than one type and they may have different dissociation constants. The cytoplasmic Ca++ ion activity is probably maintained at very low levels. PMID:512628

Normocalcemia is maintained in mice under conditions of calcium malabsorption by vitamin D–induced inhibition of bone mineralization

PubMed Central

Lieben, Liesbet; Masuyama, Ritsuko; Torrekens, Sophie; Van Looveren, Riet; Schrooten, Jan; Baatsen, Pieter; Lafage-Proust, Marie-Hélène; Dresselaers, Tom; Feng, Jian Q.; Bonewald, Lynda F.; Meyer, Mark B.; Pike, J. Wesley; Bouillon, Roger; Carmeliet, Geert

2012-01-01

Serum calcium levels are tightly controlled by an integrated hormone-controlled system that involves active vitamin D [1,25(OH)2D], which can elicit calcium mobilization from bone when intestinal calcium absorption is decreased. The skeletal adaptations, however, are still poorly characterized. To gain insight into these issues, we analyzed the consequences of specific vitamin D receptor (Vdr) inactivation in the intestine and in mature osteoblasts on calcium and bone homeostasis. We report here that decreased intestinal calcium absorption in intestine-specific Vdr knockout mice resulted in severely reduced skeletal calcium levels so as to ensure normal levels of calcium in the serum. Furthermore, increased 1,25(OH)2D levels not only stimulated bone turnover, leading to osteopenia, but also suppressed bone matrix mineralization. This resulted in extensive hyperosteoidosis, also surrounding the osteocytes, and hypomineralization of the entire bone cortex, which may have contributed to the increase in bone fractures. Mechanistically, osteoblastic VDR signaling suppressed calcium incorporation in bone by directly stimulating the transcription of genes encoding mineralization inhibitors. Ablation of skeletal Vdr signaling precluded this calcium transfer from bone to serum, leading to better preservation of bone mass and mineralization. These findings indicate that in mice, maintaining normocalcemia has priority over skeletal integrity, and that to minimize skeletal calcium storage, 1,25(OH)2D not only increases calcium release from bone, but also inhibits calcium incorporation in bone. PMID:22523068

Transient Evolution of Nonmetallic Inclusions During Calcium Treatment of Molten Steel

NASA Astrophysics Data System (ADS)

Zhang, Lifeng; Liu, Yang; Zhang, Ying; Yang, Wen; Chen, Wei

2018-06-01

The transient evolution of nonmetallic inclusions after calcium addition in pipeline steels was investigated with a vacuum induction furnace. Samples were taken at 1, 5, 10, 15, and 20 minutes after calcium treatment in both MgO and Al2O3 crucibles. It was found that the total oxygen and the number density of inclusions were increased during calcium modification, while they were dropped to a low level in the last tapped sample. Due to the evaporation of calcium, inclusions were transferred from CaO-CaS to Al2O3-CaO-CaS, and then to Al2O3-CaO. The decomposition of CaS was highly dependent on the decrease of the total calcium and the increase of the total oxygen in the steel. Thermodynamic calculation was performed to predict the composition of inclusions considering the effect of the total oxygen and the total calcium and was validated by measurement. The relationship between the content of Al2O3 in inclusions and the ratio of the total calcium and the total oxygen in steels was measured and compared with the calculated one using thermodynamic software Factsage 7.0. The mass-transfer coefficient of the dissolved calcium in the steel was estimated in the range of 2.35 × 10-4 to 3.53 × 10-4 m/s.

Effect of increased magnesium intake on plasma cholesterol, triglyceride and oxidative stress in alloxan-diabetic rats.

PubMed

Olatunji, L A; Soladoye, A O

2007-06-01

Cardiovascular disorders are the primary causes of morbidity and mortality in patients with diabetes mellitus (DM). Agents that improve lipid profile and reduce oxidative stress have been shown to reduce the ensuing risk factors. In the present study, we investigated whether increased magnesium intake could improve hyperglycaemia, dyslipidaemia, and reduce oxidative stress in alloxan-induced diabetic rats. Male Wistar rats were divided into non-diabetic (ND), diabetic (DM) and diabetic fed on a high magnesium diet (DM-Mg) groups. Plasma concentrations of thiobarbituric acid reactive substances (TBARS) were used as markers of oxidative stress. Plasma levels of ascorbic acid, magnesium and calcium were also determined. Diabetes was induced by injecting alloxan (100 mg/kg B.W). The fasting blood glucose levels were significantly lower in the DM-Mg rats than in the DM rats. Plasma total cholesterol, triglyceride, TBARS levels were significantly higher while plasma HDL-cholesterol, HDL-cholesterol/total cholesterol ratio, ascorbic acid levels were significantly lowered in DM rats compared with the ND rats. Increased intake of magnesium significantly abrogated these alterations. There were no significant differences in the plasma levels of magnesium and calcium between the DM and ND groups. However, plasma levels of magnesium but not calcium were significantly elevated in DM-Mg rats when compared with other groups. In conclusion, these results suggest that diet rich in magnesium could exert cardioprotective effect through reduced plasma total cholesterol, triglyceride, oxidative stress and ameliorated HDL-cholesterol/total cholesterol ratio as well as increased plasma ascorbic acid and magnesium in diabetic rats.

Vitamin D levels among pregnant and lactating women.

PubMed

Sharif, Saima; Farasat, Tasnim; Shoaib, Hamna; Saqib, Muhammad; Fazal, Sabiha

2013-12-01

To assess the serum level of vitamin D in pregnant and lactating women. Case-control study. Gynaecological Unit 1 of Jinnah Hospital, Lahore, from December 2010 to May 2011. A total of 100 women comprised of three groups: pregnant (n = 40), lactating (n = 40) and control (n = 20) groups. The information regarding age, educational level, socioeconomic status, exposure to sunlight and dietary vitamin D intake were collected through self-structured questionnaire. Serum concentration of vitamin D was measured by ELISA and serum calcium and phosphate levels were measured by chemistry analyzer. Statistical analysis was done using SPSS (version 13). The values were considered significant at 0.05 level of significance. The mean serum vitamin D level in the pregnant and lactating mothers was 26.5 ± 17.1 nmol/L and 21.4 ± 16.3 nmol/L respectively and in control group was 33.8 ± 21.1 nmol/L. The mean calcium level in the pregnant, lactating and control group was 10.3 ± 1.2 mg/dL, 9.7 ± 1.3 mg/dL and 9.7 ± 1.3 mg/dL respectively. The mean phosphate in pregnant was 3.2 ± 0.76 mg/dl, in lactating was 3.3 ± 0.76 mg/dl and in control was 3.5 ± 0.92 mg/dl. Significant difference (p = 0.041 and p = 0.037 respectively) in the serum levels of vitamin D and calcium was observed among the pregnant and lactating women as compared to control group. Low serum vitamin D concentration was observed in lactating women and pregnant women as compared to control group.

Aluminum and Phthalates in Calcium Gluconate: Contribution From Glass and Plastic Packaging.

PubMed

Yokel, Robert A; Unrine, Jason M

2017-01-01

Aluminum contamination of parenteral nutrition solutions has been documented for 3 decades. It can result in elevated blood, bone, and whole body aluminum levels associated with neurotoxicity, reduced bone mass and mineral content, and perhaps hepatotoxicity. The primary aluminum source among parenteral nutrition components is glass-packaged calcium gluconate, in which aluminum concentration in the past 3 decades has averaged approximately 4000 μg/L, compared with <200 μg/L in plastic container-packaged calcium gluconate. A concern about plastic packaging is leaching of plasticizers, including phthalates, which have the potential to cause endocrine (male reproductive system) disruption and neurotoxicity. Aluminum was quantified in samples collected periodically for more than 2 years from 3 calcium gluconate sources used to prepare parenteral nutrition solutions; 2 packaged in glass (from France and the United States) and 1 in plastic (from Germany); in a recently released plastic-packaged solution (from the United States); and in the 2 glass containers. Phthalate concentration was determined in selected samples of each product and leachate of the plastic containers. The initial aluminum concentration was approximately 5000 μg/L in the 2 glass-packaged products and approximately 20 μg/L in the plastic-packaged product, and increased approximately 30%, 50%, and 100% in 2 years, respectively. The aluminum concentration in a recently released Calcium Gluconate Injection USP was approximately 320 μg/L. Phthalates were not detected in any calcium gluconate solutions or leachates. Plastic packaging greatly reduces the contribution of aluminum to parenteral nutrition solutions from calcium gluconate compared with the glass-packaged product.

Hypocalcaemia after treatment with [177Lu-DOTA 0,Tyr3]octreotate.

PubMed

van Vliet, Esther I; de Herder, Wouter W; de Rijke, Yolanda B; Zillikens, M Carola; Kam, Boen L R; Teunissen, Jaap J M; Peeters, Robin P; Krenning, Eric P; Kwekkeboom, Dik J

2013-12-01

The aim of this study was to explore the possible mechanisms involved in an observed decline in serum calcium levels in patients with a neuroendocrine tumour (NET) treated with [(177)Lu-DOTA(0),Tyr(3)]octreotate ((177)Lu-octreotate). In 47 patients with NET who were normocalcaemic at baseline, serum calcium, albumin, creatinine, alkaline phosphatase, gamma glutamyl transpeptidase, magnesium, phosphate and 25-hydroxyvitamin D were prospectively analysed at baseline and up to 6 months after treatment. Parathyroid hormone (PTH), 1,25-dihydroxyvitamin D3, type 1 aminoterminal propeptide of procollagen, bone-specific alkaline phosphatase, carboxyterminal crosslinking telopeptide of bone collagen, collagen type I crosslinked N-telopeptide, and creatinine and calcium in 24-h urine samples, were evaluated at baseline and at 3 and 6 months. Another 153 patients with NET were included in a retrospective study to estimate the occurrence of hypocalcaemia in a larger patient group. In the prospectively included patients, the mean serum calcium level decreased significantly after treatment (2.31 ± 0.01 to 2.26 ± 0.02 mmol/l, p = 0.02). Eight patients (17%) showed a marked decrease in serum calcium levels with a nadir of ≤ 2.10 mmol/l. In five patients (11%), calcium substitution therapy was prescribed. PTH increased significantly (5.9 ± 0.6 to 6.7 ± 0.8 pmol/l, p = 0.02), presumably in response to the decreasing serum calcium levels. 25-Hydroxyvitamin D remained stable after treatment. Creatinine levels increased significantly (73 ± 3 to 77 ± 3 μmol/l, p = 0.01), but not enough to explain the hypocalcaemia. Phosphate levels remained unaffected. In the retrospectively analysed patients, the mean serum calcium level decreased significantly from 2.33 ± 0.01 at baseline to a nadir of 2.24 ± 0.01 mmol/l at 18 months after treatment (p < 0.001). Of the 153 patients, 33 (22%) showed a serum calcium nadir of ≤ 2.10 mmol/l, and 11 (7%) received calcium substitution therapy. The mean serum calcium level decreased significantly after treatment with (177)Lu-octreotate, resulting in mild hypocalcaemia in about 20% of patients. We excluded several potential causes of this hypocalcaemia, so the cause remains unknown. Serum calcium levels should be monitored after peptide receptor radionuclide therapy, and calcium substitution therapy should be initiated if appropriate.

Actin dynamics mediates the changes of calcium level during the pulvinus movement of Mimosa pudica

PubMed Central

Yao, Heng; Xu, Qiangyi

2008-01-01

The bending movement of the pulvinus of Mimosa pudica is caused by a rapid change in volume of the abaxial motor cells, in response to various environmental stimuli. We investigated the relationship between the actin cytoskeleton and changes in the level of calcium during rapid contractile movement of the motor cells that was induced by electrical stimulation. The bending of the pulvinus was retarded by treatments with actin-affecting reagents and calcium channel inhibitors. The actin filaments in the motor cells were fragmented in response to electrical stimulation. Further investigations were performed using protoplasts from the motor cells of M. pudica pulvini. Calcium-channel inhibitors and EGTA had an inhibitory effect on contractile movement of the protoplasts. The level of calcium increased and became concentrated in the tannin vacuole after electrical stimulation. Ruthenium Red inhibited the increase in the level of calcium in the tannin vacuole and the contractile movement of the protoplasts. However, treatment with latrunculin A abolished the inhibitory effect of Ruthenium Red. Phalloidin inhibited the contractile movement and the increase in the level of calcium in the protoplasts. Our study demonstrates that depolymerization of the actin cytoskeleton in pulvinus motor cells in response to electrical signals results in increased levels of calcium. PMID:19513198

Effects of Lowering Dialysate Calcium Concentration on Mineral and Bone Disorders in Chronic Hemodialysis Patients: Conversion from 3.0 mEq/L to 2.75 mEq/L.

PubMed

Yamada, Shunsuke; Ueki, Kenji; Tokumoto, Masanori; Suehiro, Takaichi; Kimura, Hiroshi; Taniguchi, Masatomo; Fujimi, Satoru; Kitazono, Takanari; Tsuruya, Kazuhiko

2016-02-01

Selection of a lower dialysate calcium concentration (DCa) can reduce calcium burden and prevent vascular calcification in hemodialysis patients. However, decreased DCa can worsen mineral and bone disorders. This 1-year retrospective observational study evaluated 121 hemodialysis patients at Fukuoka Renal Clinic who underwent conversion of DCa from 3.0 mEq/L to 2.75 mEq/L. The primary outcomes were changes in serum levels of calcium, phosphate, and parathyroid hormone (PTH). The effects of baseline serum calcium and PTH levels on changes in biochemical parameters were also determined. One year after DCa conversion, mean serum calcium level decreased, while serum phosphate, alkaline phosphatase, and PTH concentrations increased. The rate of achievement of target PTH was higher in patients with lower serum PTH level at baseline, while patients with higher baseline serum PTH level tended to exceed the upper limit of the PTH target range. Patients with higher baseline serum calcium concentration showed a greater decrease in serum calcium level and a greater increase in serum PTH level at 1 year. Patients with a lower baseline serum PTH level can benefit from optimal PTH control following conversion of DCa from 3.0 mEq/L to 2.75 mEq/L. However, secondary hyperparathyroidism may be exacerbated in some patients with higher baseline serum calcium (Ca) and PTH levels. These results indicate that an individualized approach can maximize the benefits of Ca unloading after conversion to lower DCa. © 2015 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

Calcium/Vitamin D Supplementation and Coronary Artery Calcification

PubMed Central

Manson, JoAnn E.; Allison, Matthew A.; Carr, J. Jeffrey; Langer, Robert D.; Cochrane, Barbara B.; Hendrix, Susan L.; Hsia, Judith; Hunt, Julie R.; Lewis, Cora E.; Margolis, Karen L.; Robinson, Jennifer G.; Rodabough, Rebecca J.; Thomas, Asha M.

2010-01-01

Objectives Coronary artery calcified plaque is a marker for atheromatous plaque burden and predicts future risk of cardiovascular events. The relationship between calcium plus vitamin D supplementation and coronary artery calcium (CAC) has not been previously assessed in a randomized trial setting. We compared coronary artery calcium scores among women randomized to calcium/vitamin D supplementation versus placebo following trial completion. Methods In an ancillary substudy of women randomized to calcium carbonate (1000 mg of elemental calcium daily) plus vitamin D3 (400 IU daily) versus placebo, nested within the Women’s Health Initiative trial of estrogen among women with hysterectomy, we measured CAC with cardiac computed tomography in 754 women aged 50–59 years at randomization. Imaging for CAC was performed at 28 of 40 centers following a mean of 7 years of treatment and scans were read centrally. Coronary artery calcium scores were measured by a central reading center with masking to randomization assignments. Results Post-trial CAC measurements were similar in women randomized to calcium/vitamin D supplementation (calcium/D) and those receiving placebo. The mean CAC score was 91.6 for calcium/D and 100.5 for placebo (rank test p-value=0.74). After adjustment for coronary risk factors, multivariate odds ratios for increasing CAC score cutpoints (CAC >0, ≥10, and ≥100) for calcium/D vs placebo were 0.92 (95% confidence interval, 0.64–1.34), 1.29 (0.88–1.87), and 0.90 (0.56–1.44), respectively. Corresponding odds ratios among women with >50% adherence to study pills and for higher levels of CAC (>300), were similar. Conclusions Treatment with moderate doses of calcium plus vitamin D3 did not appear to alter coronary artery calcified plaque burden among postmenopausal women. PMID:20551849

Osteoconduction of impacted porous titanium particles with a calcium-phosphate coating is comparable to osteoconduction of impacted allograft bone particles: in vivo study in a nonloaded goat model.

PubMed

Walschot, Lucas H B; Aquarius, René; Schreurs, Barend W; Verdonschot, Nico; Buma, Pieter

2012-08-01

Impaction grafting restores bone defects in hip arthroplasty. Defects are reconstructed with bone particles (BoP) as substitute materials with adequate mechanical and biological properties are not yet available. Ceramic particles (CeP) have mechanical drawbacks as opposed to porous titanium particles (TiP). In this in vivo study, bone ingrowth and bone volume in coated and noncoated TiP were compared to porous biphasic calcium-phospate CeP and allograft BoP. Coatings consisted of silicated calcium-phosphate and carbonated apatite. Materials were implanted in goats and impacted in cylindrical defects (diameter 8 mm) in the cancellous bone of the femur. On the basis of fluorochrome labeling and histology, bone ingrowth distance was measured at 4, 8, and 12 weeks. Cross-sectional bone area was measured at 12 weeks. TiP created a coherent matrix of entangled particles. CeP pulverized and were noncoherent. Bone ingrowth in TiP improved significantly by the coatings to levels comparable to BoP and CeP. Cross-sectional bone area was smaller in CeP and TiP compared to BoP. The osteoconductive properties of impacted TiP with a calcium-phosphate coating are comparable to impacted allograft bone and impacted biphasic ceramics. A more realistic loaded in vivo study should prove that coated TiP is an attractive alternative to allograft bone. Copyright © 2012 Wiley Periodicals, Inc.

Surface remineralization potential of casein phosphopeptide-amorphous calcium phosphate on enamel eroded by cola-drinks: An in-situ model study.

PubMed

Grewal, Navneet; Kudupudi, Vinod; Grewal, Sukrit

2013-07-01

The aim of this study was to investigate the remineralization potential of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on enamel eroded by cola drinks. A total of 30 healthy subjects were selected from a random sample of 1200 children and divided into two groups of 15 each wherein calcium and phosphorus analyses and scanning electron microscope (SEM) analysis was carried out to investigate the remineralization of enamel surface. A total of 30 non-carious premolar teeth were selected from the human tooth bank (HTB) to prepare the in-situ appliance. Three enamel slabs were prepared from the same. One enamel slab was used to obtain baseline values and the other two were embedded into the upper palatal appliances prepared on the subjects' maxillary working model. The subjects wore the appliance after which 30 ml cola drink exposure was given. After 15 days, the slabs were removed and subjected to respective analysis. Means of all the readings of soluble calcium and phosphorous levels at baseline,post cola-drink exposure and post cpp-acp application were subjected to statistical analysis SPSS11.5 version. Comparison within groups and between groups was carried out using ANOVA and F-values at 1% level of significance. Decrease in calcium solubility of enamel in the CPP-ACP application group as compared to post-cola drink exposure group (P < 0.05) was seen. Distinctive change in surface topography of enamel in the post-CPP-ACP application group as compared to post-cola drink exposure group was observed. CPP-ACP significantly promoted remineralization of enamel eroded by cola drinks as revealed by significant morphological changes seen in SEM magnification and spectrophotometric analyses.

St. John’s Wort enhances the synaptic activity of the nucleus of the solitary tract

PubMed Central

Vance, Katie M.; Ribnicky, David M.; Hermann, Gerlinda E.; Rogers, Richard C.

2014-01-01

Objective St. John’s Wort extract, which is commonly used to treat depression, inhibits the reuptake of several neurotransmitters, including glutamate, serotonin, norepinephrine, and dopamine. Glutamatergic visceral vagal afferents synapse upon neurons of the solitary tract (NST); thus, we evaluated whether St. John’s Wort extract modulates glutamatergic neurotransmission within the NST. Materials and Methods We used live cell calcium imaging to evaluate whether St. John’s Wort and its isolated components hypericin and hyperforin increase the excitability of pre-labeled vagal afferent terminals synapsing upon the NST. We used voltage-clamp recordings of spontaneous miniature excitatory postsynaptic currents (mEPSCs) to evaluate whether St. John’s Wort alters glutamate release from vagal afferents onto NST neurons. Results Our imaging data show that St. John’s Wort (50 μg/mL) increased the intracellular calcium levels of stimulated vagal afferent terminals compared to the bath control. This increase in presynaptic vagal afferent calcium by the extract coincides with an increase in neurotransmitter release within the nucleus of the solitary tract, as the frequency of mEPSCs is significantly higher in the presence of the extract compared to the control. Finally, our imaging data show that hyperforin, a known component of St. John’s Wort extract, also significantly increases terminal calcium levels. Conclusion These data suggest that St. John’s Wort extract can significantly increase the probability of glutamate release from vagal afferents onto the NST by increasing presynaptic calcium. The in vitro vagal afferent synapse with NST neurons is an ideal model system to examine the mechanism of action of botanical agents on glutamatergic neurotransmission. PMID:24985104

Recombinant γT305A fibrinogen indicates severely impaired fibrin polymerization due to the aberrant function of hole 'A' and calcium binding sites.

PubMed

Ikeda, Minami; Kobayashi, Tamaki; Arai, Shinpei; Mukai, Saki; Takezawa, Yuka; Terasawa, Fumiko; Okumura, Nobuo

2014-08-01

We examined a 6-month-old girl with inherited fibrinogen abnormality and no history of bleeding or thrombosis. Routine coagulation screening tests showed a markedly low level of plasma fibrinogen determined by functional measurement and also a low level by antigenic measurement (functional/antigenic ratio=0.295), suggesting hypodysfibrinogenemia. DNA sequence analysis was performed, and γT305A fibrinogen was synthesized in Chinese hamster ovary cells based on the results. We then functionally analyzed and compared with that of nearby recombinant γN308K fibrinogen. DNA sequence analysis revealed a heterozygous γT305A substitution (mature protein residue number). The γT305A fibrinogen indicated markedly impaired thrombin-catalyzed fibrin polymerization both in the presence or absence of 1mM calcium ion compared with that of γN308K fibrinogen. Protection of plasmin degradation in the presence of calcium ion or Gly-Pro-Arg-Pro peptide (analogue for so-called knob 'A') and factor XIIIa-catalyzed fibrinogen crosslinking demonstrated that the calcium binding sites, hole 'a' and D:D interaction sites were all markedly impaired, whereas γN308Kwas impaired at the latter two sites. Molecular modeling demonstrated that γT305 is localized at a shorter distance than γN308 from the high affinity calcium binding site and hole 'a'. Our findings suggest that γT305 might be important for construction of the overall structure of the γ module of fibrinogen. Substitution of γT305A leads to both dysfibrinogenemic and hypofibrinogenemic characterization, namely hypodysfibrinogenemia. We have already reported that recombinant γT305A fibrinogen was synthesized normally and secreted slightly, but was significantly reduced. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hemispheric asymmetry of macroscopic and elementary calcium signals mediated by InsP3 in Xenopus oocytes.

PubMed

Callamaras, N; Sun, X P; Ivorra, I; Parker, I

1998-09-01

1. The mechanisms underlying hemispheric asymmetry of the inositol 1, 4,5-trisphosphate (InsP3)-calcium signalling pathway in Xenopus oocytes were examined by fluorescence imaging of calcium signals and recording calcium-activated Cl- currents (ICl,Ca) evoked by intracellular calcium injections and photorelease of InsP3. 2. The maximal ICl,Ca evoked by strong photorelease of InsP3 was 8 times greater in the animal than the vegetal hemisphere, but the average threshold amounts of InsP3 required to evoke detectable currents were similar in each hemisphere. 3. Currents evoked by injections of calcium were about 2.5 times greater near the animal pole than near the vegetal pole, whereas fluorescence signals evoked by injections were similar in each hemisphere. 4. Calcium waves were evoked by photolysis flashes of similar strengths in both hemispheres of albino oocytes, but peak calcium levels evoked by supramaximal stimuli were 70 % greater in the animal hemisphere. 5. Elementary calcium release events (puffs) in the animal hemisphere had amplitudes about double that in the vegetal hemisphere, and more often involved coupled release from adjacent sites. Calcium release sites were more closely packed in the animal hemisphere, with a mean spacing of about 1.5 micro m compared with 2.25 micro m in the vegetal hemisphere. 6. The larger amplitude of currents mediated by InsP3 in the animal hemisphere, therefore, involves an increased flux of calcium at individual release units, a more dense packing of release units and a higher density of Cl- channels.

Hemispheric asymmetry of macroscopic and elementary calcium signals mediated by InsP3 in Xenopus oocytes

PubMed Central

Callamaras, Nick; Sun, Xiao-Ping; Ivorra, Isabel; Parker, Ian

1998-01-01

The mechanisms underlying hemispheric asymmetry of the inositol 1,4,5-trisphosphate (InsP3)-calcium signalling pathway in Xenopus oocytes were examined by fluorescence imaging of calcium signals and recording calcium-activated Cl− currents (ICl,Ca) evoked by intracellular calcium injections and photorelease of InsP3. The maximal ICl,Ca evoked by strong photorelease of InsP3 was 8 times greater in the animal than the vegetal hemisphere, but the average threshold amounts of InsP3 required to evoke detectable currents were similar in each hemisphere. Currents evoked by injections of calcium were about 2.5 times greater near the animal pole than near the vegetal pole, whereas fluorescence signals evoked by injections were similar in each hemisphere. Calcium waves were evoked by photolysis flashes of similar strengths in both hemispheres of albino oocytes, but peak calcium levels evoked by supramaximal stimuli were 70% greater in the animal hemisphere. Elementary calcium release events (puffs) in the animal hemisphere had amplitudes about double that in the vegetal hemisphere, and more often involved coupled release from adjacent sites. Calcium release sites were more closely packed in the animal hemisphere, with a mean spacing of about 1.5 μm compared with 2.25 μm in the vegetal hemisphere. The larger amplitude of currents mediated by InsP3 in the animal hemisphere, therefore, involves an increased flux of calcium at individual release units, a more dense packing of release units and a higher density of Cl− channels. PMID:9706018

The Effects of Calcium, Vitamins D and K co-Supplementation on Markers of Insulin Metabolism and Lipid Profiles in Vitamin D-Deficient Women with Polycystic Ovary Syndrome.

PubMed

Karamali, Maryam; Ashrafi, Mahnaz; Razavi, Maryamalsadat; Jamilian, Mehri; Kashanian, Maryam; Akbari, Maryam; Asemi, Zatollah

2017-05-01

Data on the effects of calcium, vitamins D and K co-supplementation on markers of insulin metabolism and lipid profiles among vitamin D-deficient women with polycystic ovary syndrome (PCOS) are scarce. This study was done to determine the effects of calcium, vitamins D and K co-supplementation on markers of insulin metabolism and lipid profiles in vitamin D-deficient women with PCOS. This randomized double-blind, placebo-controlled trial was conducted among 55 vitamin D-deficient women diagnosed with PCOS aged 18-40 years old. Subjects were randomly assigned into 2 groups to intake either 500 mg calcium, 200 IU vitamin D and 90 µg vitamin K supplements (n=28) or placebo (n=27) twice a day for 8 weeks. After the 8-week intervention, compared with the placebo, joint calcium, vitamins D and K supplementation resulted in significant decreases in serum insulin concentrations (-1.9±3.5 vs. +1.8±6.6 µIU/mL, P=0.01), homeostasis model of assessment-estimated insulin resistance (-0.4±0.7 vs. +0.4±1.4, P=0.01), homeostasis model of assessment-estimated b cell function (-7.9±14.7 vs. +7.0±30.3, P=0.02) and a significant increase in quantitative insulin sensitivity check index (+0.01±0.01 vs. -0.008±0.03, P=0.01). In addition, significant decreases in serum triglycerides (-23.4±71.3 vs. +9.9±39.5 mg/dL, P=0.03) and VLDL-cholesterol levels (-4.7±14.3 vs. +2.0±7.9 mg/dL, P=0.03) was observed following supplementation with combined calcium, vitamins D and K compared with the placebo. Overall, calcium, vitamins D and K co-supplementation for 8 weeks among vitamin D-deficient women with PCOS had beneficial effects on markers of insulin metabolism, serum triglycerides and VLDL-cholesterol levels. © Georg Thieme Verlag KG Stuttgart · New York.

Correlation of mammographic density and serum calcium levels in patients with primary breast cancer.

PubMed

Hack, Carolin C; Stoll, Martin J; Jud, Sebastian M; Heusinger, Katharina; Adler, Werner; Haeberle, Lothar; Ganslandt, Thomas; Heindl, Felix; Schulz-Wendtland, Rüdiger; Cavallaro, Alexander; Uder, Michael; Beckmann, Matthias W; Fasching, Peter A; Bayer, Christian M

2017-06-01

Percentage mammographic breast density (PMD) is one of the most important risk factors for breast cancer (BC). Calcium, vitamin D, bisphosphonates, and denosumab have been considered and partly confirmed as factors potentially influencing the risk of BC. This retrospective observational study investigated the association between serum calcium level and PMD. A total of 982 BC patients identified in the research database at the University Breast Center for Franconia with unilateral BC, calcium and albumin values, and mammogram at the time of first diagnosis were included. PMD was assessed, using a semiautomated method by two readers. Linear regression analyses were conducted to investigate the impact on PMD of the parameters of serum calcium level adjusted for albumin level, and well-known clinical predictors such as age, body mass index (BMI), menopausal status and confounder for serum calcium like season in which the BC was diagnosed. Increased calcium levels were associated with reduced PMD (P = 0.024). Furthermore, PMD was inversely associated with BMI (P < 0.001) and age (P < 0.001). There was also an association between PMD and menopausal status (P < 0.001). The goodness-of-fit of the regression model was moderate. This is the first study assessing the association between serum calcium level and PMD. An inverse association with adjusted serum calcium levels was observed. These findings add to previously published data relating to vitamin D, bisphosphonates, denosumab, and the RANK/RANKL signaling pathway in breast cancer risk and prevention. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Blood lead level and its relationship to essential elements in preschool children from Nanning, China.

PubMed

Chen, Jingwen; Li, Muyan; Lv, Qun; Chen, Guoli; Li, Yong; Li, Shaojun; Mo, Yuhuan; Ou, Shiyan; Yuan, Zongxiang; Huang, Mingli; Jiang, Yueming

2015-04-01

Our study aimed to assess the distribution of blood lead level and its relationship to essential elements in preschool children in an urban area of China. A total of 6741 children aged 0- to 6-year-old were recruited. Levels of lead, zinc, copper, iron, calcium, and magnesium in whole blood samples were determined using atomic absorption spectrometry. The mean blood lead level (BLL) and the prevalence of BLL≥10μg/dl (5.26±4.08μg/dl and 6.84%, respectively) increased with age gradually, and there was a gender-difference for blood lead, copper, zinc and iron levels. Compared with the group of children who had BLLs<5μg/dl, the groups of 5≤BLLs<10μg/dl and 10≤BLLs<15μg/dl showed higher blood zinc, iron and magnesium levels, and a lower blood calcium level. A positive correlation of lead with zinc, iron and magnesium, and a negative correlation of lead with calcium were found in the group of children with BLL<5μg/dl. Age- and gender-differences were found when assessing the BLL and intoxication prevalence in preschool children. Metabolic disorder of essential elements was found even with a low level of lead exposure. Copyright © 2014 Elsevier GmbH. All rights reserved.

Sodium lauryl sulfate impedes drug release from zinc-crosslinked alginate beads: switching from enteric coating release into biphasic profiles.

PubMed

Taha, Mutasem O; Nasser, Wissam; Ardakani, Adel; Alkhatib, Hatim S

2008-02-28

The aim of this research is to investigate the effects of sodium lauryl sulfate (SLS) on ionotropically cross-linked alginate beads. Different levels of SLS were mixed with sodium alginate and chlorpheniramine maleate (as loaded model drug). The resulting viscous solutions were dropped onto aqueous solutions of zinc or calcium ions for ionotropic curing. The generated beads were assessed by their drug releasing profiles, infrared and differential scanning colorimetery (DSC) traits. SLS was found to exert profound concentration-dependent impacts on the characteristics of zinc-crosslinked alginate beads such that moderate modifications in the levels of SLS switched drug release from enteric coating-like behavior to a biphasic release modifiable to sustained-release by the addition of minute amounts of xanthan gum. Calcium cross-linking failed to reproduce the same behavior, probably due to the mainly ionic nature of calcium-carboxylate bonds compared to the coordinate character of their zinc-carboxylate counterparts. Apparently, moderate levels of SLS repel water penetration into the beads, and therefore minimize chlorpheniramine release. However, higher SLS levels seem to discourage polymeric cross-linking and therefore allow biphasic drug release.

The intervention effect of zuogui pill on chronic kidney disease-mineral and bone disorder regulatory factor.

PubMed

Ma, Xiaohong; He, Liqun

2018-06-24

Chronic kidney disease-mineral and bone disorder (CKD-MBD) play a critical role in the pathogenesis of cardiovascular complications in patients with chronic kidney disease (CKD). Zuogui pill as a traditional Chinese herbal drug has been used for nourish kidney essence improve bone malnutrition of renal bone disease by regulating the metabolism of calcium and phosphorus and participating in osteoblast metabolism. In the present study, 5/6 nephrectomy rat model was used to reveal the mechanism of zuogui pill in treatment of CKD-MBD. Compared with sham rats, the levels of serum phosphorus, PTH, iPTH and creatinine were significantly decreased, while the serum calcium level was significantly increased, and the Cbfa1 protein level was significantly decreased and FGF23 protein level was significantly increased by Zuogui pill treatment. Compared with model rats, the BMD of rat was significantly increased by Zuogui pill treatment. Histological analysis revealed that the kidney injury of rats with CKD was significantly reduced by zuogui pill treatment. Compared with model rats, the CYP27B1 mRNA level was significantly increased, and the PTH mRNA level and NaPiIIa protein level were significantly decreased in the kidney by zuogui pill treatment. We inferred that zuogui pill exhibited potential therapeutic effects on CKD-MBD in the rats by regulating bone metabolism and nourish kidney. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Salivary alkaline phosphatase and calcium in caries-active type II diabetes mellitus patients: An in vivo study

PubMed Central

Hegde, Mithra N.; Tahiliani, Divya; Shetty, Shilpa; Devadiga, Darshana

2014-01-01

Background: Diabetes Mellitus is a metabolic syndrome, affecting the oral health in various ways with dental caries being one of the most common problems encountered. Saliva is one of the most abundant secretions in the human body with a variety of natural protective and defence molecules bathing the oral cavity maintaining equilibrium. Its collection is easy and non-invasive. Aims: To compare and evaluate salivary alkaline phosphatase levels and calcium ion levels between caries active type II diabetes mellitus patients and non-diabetics. Materials and Methods: This study was carried out on caries-active age and gender matched 60 non-diabetic and 60 patients with known Type II diabetes mellitus subjects of age group 25-50 years with DMFT index >10. Saliva sample was collected to analyse for alkaline phosphatase enzyme and concentration of calcium ions using Agappe kits. Statistical Analysis: Student ‘t’ test was used to correlate the salivary electrolyte concentration in non- diabetic and diabetic patients with dental caries. A ‘P’ value of 0.05 or less was considered significant. Results are presented as mean ± standard deviation (X ± SD). Results: The alkaline phosphatase (ALP) activity in saliva was higher in diabetic patients when compared to that of non-diabetic patients with salivary calcium ions were significantly higher in non-diabetic individuals. Conclusion: Diabetes Mellitus patients are more prone to dental caries, hence require intervention to improve the quality of saliva. PMID:25395756

Salivary calcium concentration and periodontal health of young adults in relation to tobacco smoking.

PubMed

Sutej, Ivana; Peros, Kristina; Benutic, Anica; Capak, Krunoslav; Basic, Kresimir; Rosin-Grget, Kata

2012-01-01

To evaluate the effect of tobacco smoking and salivary calcium on the periodontal status of young adults. Plaque index, gingival bleeding on probing, supragingival calculus, DMFT index, salivary flow, pH and salivary calcium in unstimulated salivary samples were recorded in smokers and nonsmokers. There were no significant differences between smokers and nonsmokers with respect to salivary flow (P = 0.08) and calcium level (P = 0.09). Significant correlations (P < 0.05) were found between a higher calcium level and higher probing depth (r = 0.60), higher number of teeth with probing depth of more than 4 mm (r = 0.70), greater clinical attachment level (r = 0.49) and lower number of teeth bleeding on probing (r = -0.50). Moderate smoking of tobacco cigarettes in young healthy subjects may not have a significant impact on salivary flow or calcium concentrations in unstimulated saliva, but an association exists between an increased level of salivary calcium and development of periodontal disease.

Reduction in the urinary aflatoxin M1 biomarker as an early indicator of the efficacy of dietary interventions to reduce exposure to aflatoxins.

PubMed

Mitchell, Nicole J; Kumi, Justice; Johnson, Natalie M; Dotse, Eunice; Marroquin-Cardona, Alicia; Wang, Jia-Sheng; Jolly, Pauline E; Ankrah, Nii-Ayi; Phillips, Timothy D

2013-08-01

Aflatoxin B1 is a persistent public health issue in Ghana. Assessment of AFB1 intervention efficacy is currently dependent on long-term biomarkers. This study was designed to determine whether daily AFM1 biomarker levels could be utilized as an early detection method for intervention efficacy. Participants were treated with a refined calcium montmorillonite clay (UPSN) or a placebo (calcium carbonate) in a crossover study. Urine samples were assessed for AFM1 levels daily. UPSN treatment reduced AFM1 biomarkers by 55% compared to the placebo. This is the first study to show that daily urinary AFM1 levels can be used as a biomarker of internal aflatoxin B1 exposure in short-term intervention trials to determine efficacy.

Biochemical effects of lead exposure on battery manufacture workers with reference to blood pressure, calcium metabolism and bone mineral density.

PubMed

Dongre, Nilima N; Suryakar, Adinath N; Patil, Arun J; Hundekari, Indira A; Devarnavadagi, Basavaraj B

2013-01-01

Lead is one of the most widely scattered toxic metals in the environment and used by mankind for over 9,000 years. Lead in the environment may be derived from natural or anthropogenic sources. In humans, lead can cause a wide range of biological effects depending upon the level and duration of exposure. The purpose of this study was to find out the effect of lead exposure on systolic and diastolic blood pressure, serum calcium, ionized calcium, phosphorus, parathyroid hormone and vitamin D and examine the overall effect of all these parameters on the bone mineral density of battery manufacture workers. For this study ninety battery manufacture workers were selected and divided in three groups depending upon duration of lead exposure. Group I-workers with duration of lead exposure 1-5 years, Group II-workers with duration of lead exposure 6-10 years and Group III-workers with duration of lead exposure more than 10 years. Each group consisted of thirty workers. Thirty age matched healthy control subjects were taken for comparison. Demographic, occupational and clinical data were collected by using questionnaire and interview. The venous blood samples were collected from the study groups and normal healthy control group. At the time of blood collection random urine samples were collected in amber coloured bottles. The biochemical parameters were estimated by using standard assay procedures. Statistical analysis of the data was done using independent student't' test for parametric variables. Values were expressed as mean ± standard deviation (SD). P values of 0.05 or less were considered to be statistically significant. The blood lead levels and urinary lead levels of all workers were significantly increased (P < 0.001) in proportion to the duration of lead exposure as compared to controls. Systolic and diastolic blood pressure were significantly raised (P < 0.001) in all three study groups of battery manufacture workers as compared to controls. Serum Calcium, Ionized calcium, phosphorus were significantly decreased (P < 0.001) in all the three study groups. Serum vitamin D levels were lowered (P < 0.01) and serum PTH was increased (P < 0.01) in workers as compared to controls. The results of this study clearly indicate that the absorption of lead is more in these workers which adversely affects blood pressure, disturbs calcium and phosphorus metabolism which further impairs mineralization of bone resulting in decreased bone mineral density observed in these workers. Lead toxicity is still persistent in battery manufacture workers though they are using sophisticated techniques in these industries. There is a need to protect the workers from the health hazards of occupational lead exposure.

The Use of Calcimimetics for the Treatment of Secondary Hyperparathyroidism: A 10 Year Evidence Review.

PubMed

Rodríguez, Mariano; Goodman, William G; Liakopoulos, Vassilios; Messa, Piergiorgio; Wiecek, Andrzej; Cunningham, John

2015-01-01

Until the discovery of calcimimetics, the management of secondary hyperparathyroidism (SHPT) relied exclusively on treatment with phosphate binders, vitamin D derivatives or surgical parathyroidectomy with limited success. The therapeutic use of calcimimetic agents, together with a better understanding of the pivotal role of the calcium-sensing receptor (CaSR) in the physiological regulation of parathyroid gland function, substantially advanced the management of hyperparathyroidism in dialysis practice. Calcimimetics bind selectively to the CaSR receptor in parathyroid tissue and enhance the inhibitory effect of extracellular calcium ions on parathyroid hormone (PTH) secretion, thereby reducing PTH levels even when serum calcium concentrations are normal or low. The availability of calcimimetic agents for clinical use has opened a new era in the management of patients with SHPT. Indeed, calcimimetic compounds have been shown to reduce PTH levels and to lower serum calcium concentrations in all forms of hyperparathyroidism, including primary hyperparathyroidism (PHPT) and parathyroid carcinoma. Such findings underscore the critical importance of the CaSR as a therapeutic target in this family of clinical disorders. New calcimimetic agents are being developed that have the potential to offer improved efficacy and safety compared with currently available calcimimetic compounds. © 2015 Wiley Periodicals, Inc.

Low intakes of carotene, vitamin B2 , pantothenate and calcium predict cognitive decline among elderly patients with diabetes mellitus: The Japanese Elderly Diabetes Intervention Trial.

PubMed

Araki, Atsushi; Yoshimura, Yukio; Sakurai, Takashi; Umegaki, Hiroyuki; Kamada, Chiemi; Iimuro, Satoshi; Ohashi, Yasuo; Ito, Hideki

2017-08-01

The present study aimed to examine whether nutrient intakes predicted cognitive decline among elderly patients with diabetes mellitus. This study evaluated data from a 6-year prospective follow up of 237 elderly patients (aged ≥65 years) with diabetes mellitus, and the associations of baseline nutrient intakes with cognitive decline. Cognitive decline was defined as a ≥2-point decrease in the Mini-Mental State Examination (MMSE) score. Intakes of food and nutrients were assessed using a validated food frequency questionnaire, and were compared between patients with cognitive decline and intact cognition. Analysis of covariance and logistic regression analysis were used to compare the changes in the MMSE score during the follow up among intake tertile groups for each nutrient. Compared with men with intact cognition, the men with cognitive decline had lower baseline intakes of calcium, vitamin A, vitamin B 2 , pantothenate, soluble fiber, green vegetables and milk. However, no significant associations between cognitive decline and nutrient intakes were observed among women. After adjusting for age, body mass index, glycated hemoglobin levels, history of severe hypoglycemia, previous stroke and baseline MMSE score, we found that cognitive decline was significantly associated with low intakes of carotene, vitamin B 2 , pantothenate, calcium and green vegetables. Multiple logistic regression analysis showed that intakes of nutrients and green vegetables predicted cognitive decline after adjusting for age, body mass index, glycated hemoglobin levels, baseline MMSE score, and incident stroke during the follow up. These findings suggest that sufficient intakes of carotene, vitamin B 2 , pantothenate, calcium and vegetables could help prevent cognitive decline among elderly men with diabetes mellitus. Geriatr Gerontol Int 2017; 17: 1168-1175. © 2016 Japan Geriatrics Society.

Preventing post-operative hypocalcemia in Graves’ patients: A prospective study

PubMed Central

Oltmann, Sarah C.; Brekke, Andrew V.; Schneider, David F.; Schaefer, Sarah C.; Chen, Herbert; Sippel, Rebecca S.

2014-01-01

Background Hypocalcemia occurs after total thyroidectomy (TT) for Graves’ disease via parathyroid injury and/or from increased bone turnover. Current management is to supplement calcium after surgery. This study evaluates the impact of preoperative calcium supplementation on hypocalcemia after Graves’ TT. Methods A prospective study of Graves’ patients undergoing TT was performed. Graves’ patients managed over a 9 month period took 1gm of calcium carbonate (CC) three times a day for two weeks before TT. Those managed the previous year, without supplementation served as historic controls. Age-, gender-, and thyroid weight-matched, non-Graves’ TT patients were procedure controls. Patient demographics, postoperative laboratory values, complaints and medications were reviewed. PTH based postoperative protocols dictated postoperative CC and calcitriol use. Results 45 Graves’ patients were treated with CC before TT, while 38 Graves’ patients were not. 40 non-Graves’ controls were identified. Age, gender and thyroid weight were comparable. Pre-operative calcium and PTH levels were equivalent. PTH values immediately after surgery, POD 1 and at 2 week follow-up were equivalent. Post-operative use of scheduled CC(p=0.10) and calcitriol(p=0.60) was similar. Post-operatively, untreated Graves’ had lower serum calcium levels than pre-treated Graves’ or non-Graves’ controls(8.3mg/dL vs. 8.6 vs. 8.6, p=0.05). Complaints of numbness and tingling were more common in non-treated Graves’(26%) than pretreated Graves’(9%) or non-Graves’ controls(10%, p<0.05). Conclusions Calcium supplementation before TT for Graves’ significantly reduced biochemical and symptomatic postoperative hypocalcemia. Preoperative calcium supplementation is a simple treatment that can reduce symptoms of hypocalcemia after Graves’ TT. PMID:25212835

Development of poly(aspartic acid-co-malic acid) composites for calcium carbonate and sulphate scale inhibition.

PubMed

Mithil Kumar, N; Gupta, Sanjay Kumar; Jagadeesh, Dani; Kanny, K; Bux, F

2015-01-01

Polyaspartic acid (PSI) is suitable for the inhibition of inorganic scale deposition. To enhance its scale inhibition efficiency, PSI was modified by reacting aspartic acid with malic acid (MA) using thermal polycondensation polymerization. This reaction resulted in poly(aspartic acid-co-malic acid) (PSI-co-MA) dual polymer. The structural, chemical and thermal properties of the dual polymers were analysed by using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and gel permeation chromatography. The effectiveness of six different molar ratios of PSI-co-MA dual polymer for calcium carbonate and calcium sulphate scale inhibition at laboratory scale batch experiments was evaluated with synthetic brine solution at selected doses of polymer at 65-70°C by the static scale test method. The performance of PSI-co-MA dual polymer for the inhibition of calcium carbonate and calcium sulphate precipitation was compared with that of a PSI single polymer. The PSI-co-MA exhibited excellent ability to control inorganic minerals, with approximately 85.36% calcium carbonate inhibition and 100% calcium sulphate inhibition at a level of 10 mg/L PSI-co-MA, respectively. Therefore, it may be reasonably concluded that PSI-co-MA is a highly effective scale inhibitor for cooling water treatment applications.

Proteinaceous and oligosaccharidic elicitors induce different calcium signatures in the nucleus of tobacco cells.

PubMed

Lecourieux, David; Lamotte, Olivier; Bourque, Stéphane; Wendehenne, David; Mazars, Christian; Ranjeva, Raoul; Pugin, Alain

2005-12-01

We previously reported elevated cytosolic calcium levels in tobacco cells in response to elicitors [D. Lecourieux, C. Mazars, N. Pauly, R. Ranjeva, A. Pugin, Analysis and effects of cytosolic free calcium elevations in response to elicitors in Nicotiana plumbaginifolia cells, Plant Cell 14 (2002) 2627-2641]. These data suggested that in response to elicitors, Ca2+, as a second messenger, was involved in both systemic acquired resistance (RSA) and/or hypersensitive response (HR) depending on calcium signature. Here, we used transformed tobacco cells with apoaequorin expressed in the nucleus to monitor changes in free nuclear calcium concentrations ([Ca2+](nuc)) in response to elicitors. Two types of elicitors are compared: proteins leading to necrosis including four elicitins and harpin, and non-necrotic elicitors including flagellin (flg22) and two oligosaccharidic elicitors, namely the oligogalacturonides (OGs) and the beta-1,3-glucan laminarin. Our data indicate that the proteinaceous elicitors induced a pronounced and sustainable [Ca2+](nuc) elevation, relative to the small effects of oligosaccharidic elicitors. This [Ca2+](nuc) elevation, which seems insufficient to induce cell death, is unlikely to result directly from the diffusion of calcium from the cytosol. The [Ca2+](nuc) rise depends on free cytosolic calcium, IP3, and active oxygen species (AOS) but is independent of nitric oxide.

Demonstration of the existence of receptor-dependent calcium channels in the platelets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avdonin, P.V.; Bugrii, E.M.; Cheglakov, I.B.

1987-01-01

Recently, with the new methodology of measuring calcium ion concentration in the cytoplasm with the aid of the fluorescent indicator, it has been shown that calcium is a second messenger, mediating the action of many hormones, neuromediators, and other extracellular factors. Another argument in support of the existence of receptor-dependent calcium channels is provided by data on the activation by agonists of the uptake of /sup 45/Ca by the cells. In all the studies cited, the conditions were such that the passage of Ca/sup 2 +/ through the potential-dependent channels was excluded. In this paper, evidence is presented for themore » existence of receptor-dependent calcium channels in the plasma membrane using human platelets as the objects. Two approaches were used. First, the authors determined the binding of /sup 45/Ca by the platelets. In this case, to determine whether /sup 45/Ca passes into the cytoplasm or is adsorbed on the membrane, the authors compared its uptake by simply washed platelets and by platelets in whose cytoplasm buffer capacity for calcium was artificially created with quin 2. The second approach was based on the data of Hallam and Rink, who showed that agonists that increase the calcium level in the platelets induce an intake of Mn/sup 2 +/ ions into the cell in a calcium-free medium.« less

Protective Effect of Dietary Calcium Intake on Esophageal Cancer Risk: A Meta-Analysis of Observational Studies.

PubMed

Li, Qianwen; Cui, Lingling; Tian, Yalan; Cui, Han; Li, Li; Dou, Weifeng; Li, Haixia; Wang, Ling

2017-05-18

Although several epidemiological studies have investigated the association between dietary calcium intake and the risk of esophageal cancer, the results are inconsistent. This study aimed to make a comprehensive evaluation regarding the association between calcium intake and risk of esophageal cancer through a meta-analysis approach. We searched for all relevant articles from the inception to April 2017, using PUBMED, EMBASE, and Web of Knowledge. The pooled odds ratio (ORs) with the 95% confidence interval (95% CI) for the highest versus the lowest categories of calcium intake was calculated using a Mantel-Haenszel fixed-effect model. In total, 15 articles reporting 17 studies including 3396 esophageal cancer cases and 346,815 controls were selected for the meta-analysis. By comparing the highest vs. the lowest levels of dietary calcium intake, we found that dietary calcium intake was inversely associated with the risk of esophageal cancer (OR = 0.80, 95% CI: 0.71-0.91, I ² = 33.6%). The subgroup analysis indicated that the protective function of dietary calcium intake were observed in esophageal squamous cell cancer, but not in esophageal adenocarcinoma in the studies conducted in Asia, but not those in Europe and America. In conclusion, our results suggest that higher dietary calcium intake is associated with a lower risk of esophageal cancer-especially esophageal squamous cell cancer-in Asian populations, though more data from prospective cohort studies are needed.

Calcium plus vitamin D supplementation and joint symptoms in postmenopausal women in the women's health initiative randomized trial.

PubMed

Chlebowski, Rowan T; Pettinger, Mary; Johnson, Karen C; Wallace, Robert; Womack, Catherine; Mossavar-Rahmani, Yasmin; Stefanick, Marcia; Wactawski-Wende, Jean; Carbone, Laura; Lu, Bing; Eaton, Charles; Walitt, Brian; Kooperberg, Charles L

2013-10-01

Low vitamin D intake and levels have been associated with increased joint symptoms in some observational studies but the findings are mixed and evidence from randomized trials sparse. To evaluate the influence of supplemental calcium and vitamin D on joint symptoms in the Women's Health Initiative randomized, placebo-controlled, clinical trial. In post hoc analyses, the results of the Women's Health Initiative randomized clinical trial in which 36,282 postmenopausal women were randomized to receive calcium carbonate (1,000 mg as elemental calcium) with vitamin D-3 (400 IU) daily or placebo were examined in the 6% subgroup of 1,911 participants, oversampled for minorities, who had serial joint symptom assessment. Qualitative information on joint pain and joint swelling was collected by questionnaire before entry and 2 years after randomization. Logistic regression models were used to compare the occurrence and severity of joint symptoms across randomization groups. At baseline, total calcium and vitamin D intakes from diet and supplements were similar in the two randomization groups. In addition, both joint pain (reported by 73%) and joint swelling (reported by 34%) were commonly reported and comparable in the supplement and placebo groups. Two years after randomization, no statistically significant differences between supplement and placebo groups were seen for joint pain frequency (74.6% compared with 75.1% [P=0.79] for supplement and placebo groups, respectively) or joint swelling frequency (34.6% compared with 32.4% [P=0.29], respectively) or in severity scores for either outcome. Subgroup analyses suggested study participants also using nonprotocol calcium supplements at study entry may have less joint pain with supplement group randomization (interaction P=0.02). Joint symptoms are relatively common in postmenopausal women. However, daily supplementation with 1,000 mg calcium carbonate and 400 IU vitamin D-3 in a randomized, placebo-controlled clinical trial setting did not reduce the self-reported frequency or severity of joint symptoms. Copyright © 2013 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Bepridil decreases Aβ and calcium levels in the thalamus after middle cerebral artery occlusion in rats

PubMed Central

Sarajärvi, Timo; Lipsanen, Anu; Mäkinen, Petra; Peräniemi, Sirpa; Soininen, Hilkka; Haapasalo, Annakaisa; Jolkkonen, Jukka; Hiltunen, Mikko

2012-01-01

Alzheimer's disease (AD) and cerebral ischaemia share similar features in terms of altered amyloid precursor protein (APP) processing and β-amyloid (Aβ) accumulation. We have previously shown that Aβ and calcium deposition, and β-secretase activity, are robustly increased in the ipsilateral thalamus after transient middle cerebral artery occlusion (MCAO) in rats. Here, we investigated whether the non-selective calcium channel blocker bepridil, which also inhibits β-secretase cleavage of APP, affects thalamic accumulation of Aβ and calcium and in turn influences functional recovery in rats subjected to MCAO. A 27-day bepridil treatment (50 mg/kg, p.o.) initiated 2 days after MCAO significantly decreased the levels of soluble Aβ40, Aβ42 and calcium in the ipsilateral thalamus, as compared with vehicle-treated MCAO rats. Expression of seladin-1/DHCR24 protein, which is a potential protective factor against neuronal damage, was decreased at both mRNA and protein levels in the ipsilateral thalamus of MCAO rats. Conversely, bepridil treatment restored seladin-1/DHCR24 expression in the ipsilateral thalamus. Bepridil treatment did not significantly affect heme oxygenase-1- or NAD(P)H quinone oxidoreductase-1-mediated oxidative stress or inflammatory responses in the ipsilateral thalamus of MCAO rats. Finally, bepridil treatment mitigated MCAO-induced alterations in APP processing in the ipsilateral thalamus and improved contralateral forelimb use in MCAO rats. These findings suggest that bepridil is a plausible therapeutic candidate in AD or stroke owing to its multifunctional role in key cellular events that are relevant for the pathogenesis of these diseases. PMID:22805236

Chronic alcohol feeding potentiates hormone-induced calcium signalling in hepatocytes.

PubMed

Bartlett, Paula J; Antony, Anil Noronha; Agarwal, Amit; Hilly, Mauricette; Prince, Victoria L; Combettes, Laurent; Hoek, Jan B; Gaspers, Lawrence D

2017-05-15

Chronic alcohol consumption causes a spectrum of liver diseases, but the pathogenic mechanisms driving the onset and progression of disease are not clearly defined. We show that chronic alcohol feeding sensitizes rat hepatocytes to Ca 2+ -mobilizing hormones resulting in a leftward shift in the concentration-response relationship and the transition from oscillatory to more sustained and prolonged Ca 2+ increases. Our data demonstrate that alcohol-dependent adaptation in the Ca 2+ signalling pathway occurs at the level of hormone-induced inositol 1,4,5 trisphosphate (IP 3 ) production and does not involve changes in the sensitivity of the IP 3 receptor or size of internal Ca 2+ stores. We suggest that prolonged and aberrant hormone-evoked Ca 2+ increases may stimulate the production of mitochondrial reactive oxygen species and contribute to alcohol-induced hepatocyte injury. ABSTRACT: 'Adaptive' responses of the liver to chronic alcohol consumption may underlie the development of cell and tissue injury. Alcohol administration can perturb multiple signalling pathways including phosphoinositide-dependent cytosolic calcium ([Ca 2+ ] i ) increases, which can adversely affect mitochondrial Ca 2+ levels, reactive oxygen species production and energy metabolism. Our data indicate that chronic alcohol feeding induces a leftward shift in the dose-response for Ca 2+ -mobilizing hormones resulting in more sustained and prolonged [Ca 2+ ] i increases in both cultured hepatocytes and hepatocytes within the intact perfused liver. Ca 2+ increases were initiated at lower hormone concentrations, and intercellular calcium wave propagation rates were faster in alcoholics compared to controls. Acute alcohol treatment (25 mm) completely inhibited hormone-induced calcium increases in control livers, but not after chronic alcohol-feeding, suggesting desensitization to the inhibitory actions of ethanol. Hormone-induced inositol 1,4,5 trisphosphate (IP 3 ) accumulation and phospholipase C (PLC) activity were significantly potentiated in hepatocytes from alcohol-fed rats compared to controls. Removal of extracellular calcium, or chelation of intracellular calcium did not normalize the differences in hormone-stimulated PLC activity, indicating calcium-dependent PLCs are not upregulated by alcohol. We propose that the liver 'adapts' to chronic alcohol exposure by increasing hormone-dependent IP 3 formation, leading to aberrant calcium increases, which may contribute to hepatocyte injury. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Toward the establishment of standardized in vitro tests for lipid-based formulations, part 6: effects of varying pancreatin and calcium levels.

PubMed

Sassene, Philip; Kleberg, Karen; Williams, Hywel D; Bakala-N'Goma, Jean-Claude; Carrière, Frédéric; Calderone, Marilyn; Jannin, Vincent; Igonin, Annabel; Partheil, Anette; Marchaud, Delphine; Jule, Eduardo; Vertommen, Jan; Maio, Mario; Blundell, Ross; Benameur, Hassan; Porter, Christopher J H; Pouton, Colin W; Müllertz, Anette

2014-11-01

The impact of pancreatin and calcium addition on a wide array of lipid-based formulations (LBFs) during in vitro lipolysis, with regard to digestion rates and distribution of the model drug danazol, was investigated. Pancreatin primarily affected the extent of digestion, leaving drug distribution somewhat unaffected. Calcium only affected the extent of digestion slightly but had a major influence on drug distribution, with more drug precipitating at higher calcium levels. This is likely to be caused by a combination of removal of lipolysis products from solution by the formation of calcium soaps and calcium precipitating with bile acids, events known to reduce the solubilizing capacity of LBFs dispersed in biorelevant media. Further, during the digestion of hydrophilic LBFs, like IIIA-LC, the un-ionized-ionized ratio of free fatty acids (FFA) remained unchanged at physiological calcium levels. This makes the titration curves at pH 6.5 representable for digestion. However, caution should be taken when interpreting lipolysis curves of lipophilic LBFs, like I-LC, at pH 6.5, at physiological levels of calcium (1.4 mM); un-ionized-ionized ratio of FFA might change during digestion, rendering the lipolysis curve at pH 6.5 non-representable for the total digestion. The ratio of un-ionized-ionized FFAs can be maintained during digestion by applying non-physiological levels of calcium, resulting in a modified drug distribution with increased drug precipitation. However, as the main objective of the in vitro digestion model is to evaluate drug distribution, which is believed to have an impact on bioavailability in vivo, a physiological level (1.4 mM) of calcium is preferred.

Calcium: A novel and efficient inducer of differentiation of adipose-derived stem cells into neuron-like cells.

PubMed

Goudarzi, Farjam; Tayebinia, Heidar; Karimi, Jamshid; Habibitabar, Elahe; Khodadadi, Iraj

2018-06-05

This study comparatively investigated the effectiveness of calcium and other well-known inducers such as isobutylmethylxanthine (IBMX) and insulin in differentiating human adipose-derived stem cells (ADSCs) into neuronal-like cells. ADSCs were immunophenotyped and differentiated into neuron-like cells with different combinations of calcium, IBMX, and insulin. Calcium mobilization across the membrane was determined. Differentiated cells were characterized by cell cycle profiling, staining of Nissl bodies, detecting the gene expression level of markers such as neuronal nuclear antigen (NeuN), microtubule associated protein 2 (MAP2), neuron-specific enolase (NSE), doublecortin, synapsin I, glial fibrillary acidic protein (GFAP), and myelin basic protein (MBP) by quantitative real-time polymerase chain reaction (quantitative real-time polymerase chain reaction (qRT-PCR) and protein level by the immunofluorescence technique. Treatment with Ca + IBMX + Ins induced neuronal appearance and projection of neurite-like processes in the cells, accompanied with inhibition of proliferation and halt in the cell cycle. A significantly higher expression of MBP, GFAP, NeuN, NSE, synapsin 1, doublecortin, and MAP2 was detected in differentiated cells, confirming the advantages of Ca + IBMX + Ins to the other combinations of inducers. Here, we showed an efficient protocol for neuronal differentiation of ADSCs, and calcium fostered differentiation by augmenting the number of neuron-like cells and instantaneous increase in the expression of neuronal markers. © 2018 Wiley Periodicals, Inc.

Diet, but not oral probiotics, effectively reduces urinary oxalate excretion and calcium oxalate supersaturation.

PubMed

Lieske, John C; Tremaine, William J; De Simone, Claudio; O'Connor, Helen M; Li, Xujian; Bergstralh, Eric J; Goldfarb, David S

2010-12-01

We examined the effect of a controlled diet and two probiotic preparations on urinary oxalate excretion, a risk factor for calcium oxalate kidney stone formation, in patients with mild hyperoxaluria. Patients were randomized to a placebo, a probiotic, or a synbiotic preparation. This tested whether these probiotic preparations can increase oxalate metabolism in the intestine and/or decrease oxalate absorption from the gut. Patients were maintained on a controlled diet to remove the confounding variable of differing oxalate intake from food. Urinary oxalate excretion and calcium oxalate supersaturation on the controlled diet were significantly lower compared with baseline on a free-choice diet. Neither study preparation reduced urinary oxalate excretion nor calcium oxalate supersaturation. Fecal lactobacilli colony counts increased on both preparations, whereas enterococcal and yeast colony counts were increased on the synbiotic. Total urine volume and the excretion of oxalate and calcium were all strong independent determinants of urinary calcium oxalate supersaturation. Hence, dietary oxalate restriction reduced urinary oxalate excretion, but the tested probiotics did not influence urinary oxalate levels in patients on a restricted oxalate diet. However, this study suggests that dietary oxalate restriction is useful for kidney stone prevention.

The effect of calcium hydroxide, alkali dilution and calcium concentration in mitigating the alkali silica reaction using palm oil fuel ash

NASA Astrophysics Data System (ADS)

Asrah, Hidayati; Mirasa, Abdul Karim; Bolong, Nurmin

2018-02-01

This study investigated the mechanism of how POFA mitigated the ASR expansion. Two types of POFA; the UPOFA and GPOFA with different fineness were used to replace the cement at 20% and 40% and their effects on the mortar bar expansion, calcium hydroxide, alkali dilution, and calcium concentration were investigated. The results showed that UPOFA has a significant ability to mitigate the ASR, even at a lower level of replacement (20%) compared to GPOFA. The mechanism of UPOFA in mitigating the ASR expansion was through a reduction in the calcium hydroxide content, which produced low calcium concentration within the mortar pore solution. Low pore solution alkalinity signified that UPOFA had good alkali dilution effect. Meanwhile, a higher dosage of GPOFA was required to mitigate the ASR expansion. An increase in the pore solution alkalinity of GPOFA mortar indicated higher penetration of alkalis from the NaOH solution, which reduced the alkali dilution effect. However, this was compensated by the increase in the cement dilution effect at higher GPOFA replacement, which controlled the mortar bar expansion below the ASTM limit.

Diuretics, calciuria and secondary hyperparathyroidism in the Chronic Renal Insufficiency Cohort.

PubMed

Isakova, Tamara; Anderson, Cheryl A M; Leonard, Mary B; Xie, Dawei; Gutiérrez, Orlando M; Rosen, Leigh K; Theurer, Jacquie; Bellovich, Keith; Steigerwalt, Susan P; Tang, Ignatius; Anderson, Amanda Hyre; Townsend, Raymond R; He, Jiang; Feldman, Harold I; Wolf, Myles

2011-04-01

Secondary hyperparathyroidism is a common complication of chronic kidney disease (CKD) that is associated with bone disease, cardiovascular disease and death. Pathophysiological factors that maintain secondary hyperparathyroidism in advanced CKD are well-known, but early mechanisms of the disease that can be targeted for its primary prevention are poorly understood. Diuretics are widely used to control volume status and blood pressure in CKD patients but are also known to have important effects on renal calcium handling, which we hypothesized could alter the risk of secondary hyperparathyroidism. We examined the relationship of diuretic treatment with urinary calcium excretion, parathyroid hormone (PTH) levels and prevalence of secondary hyperparathyroidism (PTH ≥ 65 pg/mL) in a cross-sectional study of 3616 CKD patients in the Chronic Renal Insufficiency Cohort. Compared with no diuretics, treatment with loop diuretics was independently associated with higher adjusted urinary calcium (55.0 versus 39.6 mg/day; P < 0.001), higher adjusted PTH [67.9, 95% confidence interval (CI) 65.2-70.7 pg/mL, versus 52.8, 95% CI 51.1-54.6 pg/mL, P < 0.001] and greater odds of secondary hyperparathyroidism (odds ratio 2.1; 95% CI 1.7-2.6). Thiazide monotherapy was associated with lower calciuria (25.5 versus 39.6 mg/day; P < 0.001) but only modestly lower PTH levels (50.0, 95% CI 47.8-52.3, versus 520.8, 95% CI 51.1-54.6 pg/mL, P = 0.04) compared with no diuretics. However, coadministration of thiazide and loop diuretics was associated with blunted urinary calcium (30.3 versus 55.0 mg/day; P <0.001) and odds of hyperparathyroidism (odds ratio 1.3 versus 2.1; P for interaction = 0.05) compared with loop diuretics alone. Loop diuretic use was associated with greater calciuria, PTH levels and odds of secondary hyperparathyroidism compared to no treatment. These associations were attenuated in patients who were coadministered thiazides. Diuretic choice is a potentially modifiable determinant of secondary hyperparathyroidism in CKD.

Diuretics, calciuria and secondary hyperparathyroidism in the Chronic Renal Insufficiency Cohort

PubMed Central

Isakova, Tamara; Anderson, Cheryl A. M.; Leonard, Mary B.; Xie, Dawei; Gutiérrez, Orlando M.; Rosen, Leigh K.; Theurer, Jacquie; Bellovich, Keith; Steigerwalt, Susan P.; Tang, Ignatius; Anderson, Amanda Hyre; Townsend, Raymond R.; He, Jiang; Feldman, Harold I.; Wolf, Myles

2011-01-01

Background. Secondary hyperparathyroidism is a common complication of chronic kidney disease (CKD) that is associated with bone disease, cardiovascular disease and death. Pathophysiological factors that maintain secondary hyperparathyroidism in advanced CKD are well-known, but early mechanisms of the disease that can be targeted for its primary prevention are poorly understood. Diuretics are widely used to control volume status and blood pressure in CKD patients but are also known to have important effects on renal calcium handling, which we hypothesized could alter the risk of secondary hyperparathyroidism. Methods. We examined the relationship of diuretic treatment with urinary calcium excretion, parathyroid hormone (PTH) levels and prevalence of secondary hyperparathyroidism (PTH ≥ 65 pg/mL) in a cross-sectional study of 3616 CKD patients in the Chronic Renal Insufficiency Cohort. Results. Compared with no diuretics, treatment with loop diuretics was independently associated with higher adjusted urinary calcium (55.0 versus 39.6 mg/day; P < 0.001), higher adjusted PTH [67.9, 95% confidence interval (CI) 65.2–70.7 pg/mL, versus 52.8, 95% CI 51.1–54.6 pg/mL, P < 0.001] and greater odds of secondary hyperparathyroidism (odds ratio 2.1; 95% CI 1.7–2.6). Thiazide monotherapy was associated with lower calciuria (25.5 versus 39.6 mg/day; P < 0.001) but only modestly lower PTH levels (50.0, 95% CI 47.8–52.3, versus 520.8, 95% CI 51.1–54.6 pg/mL, P = 0.04) compared with no diuretics. However, coadministration of thiazide and loop diuretics was associated with blunted urinary calcium (30.3 versus 55.0 mg/day; P <0.001) and odds of hyperparathyroidism (odds ratio 1.3 versus 2.1; P for interaction = 0.05) compared with loop diuretics alone. Conclusions. Loop diuretic use was associated with greater calciuria, PTH levels and odds of secondary hyperparathyroidism compared to no treatment. These associations were attenuated in patients who were coadministered thiazides. Diuretic choice is a potentially modifiable determinant of secondary hyperparathyroidism in CKD. PMID:21382989

Voltage imaging to understand connections and functions of neuronal circuits.

PubMed

Antic, Srdjan D; Empson, Ruth M; Knöpfel, Thomas

2016-07-01

Understanding of the cellular mechanisms underlying brain functions such as cognition and emotions requires monitoring of membrane voltage at the cellular, circuit, and system levels. Seminal voltage-sensitive dye and calcium-sensitive dye imaging studies have demonstrated parallel detection of electrical activity across populations of interconnected neurons in a variety of preparations. A game-changing advance made in recent years has been the conceptualization and development of optogenetic tools, including genetically encoded indicators of voltage (GEVIs) or calcium (GECIs) and genetically encoded light-gated ion channels (actuators, e.g., channelrhodopsin2). Compared with low-molecular-weight calcium and voltage indicators (dyes), the optogenetic imaging approaches are 1) cell type specific, 2) less invasive, 3) able to relate activity and anatomy, and 4) facilitate long-term recordings of individual cells' activities over weeks, thereby allowing direct monitoring of the emergence of learned behaviors and underlying circuit mechanisms. We highlight the potential of novel approaches based on GEVIs and compare those to calcium imaging approaches. We also discuss how novel approaches based on GEVIs (and GECIs) coupled with genetically encoded actuators will promote progress in our knowledge of brain circuits and systems. Copyright © 2016 the American Physiological Society.

Voltage imaging to understand connections and functions of neuronal circuits

PubMed Central

Antic, Srdjan D.; Empson, Ruth M.

2016-01-01

Understanding of the cellular mechanisms underlying brain functions such as cognition and emotions requires monitoring of membrane voltage at the cellular, circuit, and system levels. Seminal voltage-sensitive dye and calcium-sensitive dye imaging studies have demonstrated parallel detection of electrical activity across populations of interconnected neurons in a variety of preparations. A game-changing advance made in recent years has been the conceptualization and development of optogenetic tools, including genetically encoded indicators of voltage (GEVIs) or calcium (GECIs) and genetically encoded light-gated ion channels (actuators, e.g., channelrhodopsin2). Compared with low-molecular-weight calcium and voltage indicators (dyes), the optogenetic imaging approaches are 1) cell type specific, 2) less invasive, 3) able to relate activity and anatomy, and 4) facilitate long-term recordings of individual cells' activities over weeks, thereby allowing direct monitoring of the emergence of learned behaviors and underlying circuit mechanisms. We highlight the potential of novel approaches based on GEVIs and compare those to calcium imaging approaches. We also discuss how novel approaches based on GEVIs (and GECIs) coupled with genetically encoded actuators will promote progress in our knowledge of brain circuits and systems. PMID:27075539

Presynaptic strontium dynamics and synaptic transmission.

PubMed Central

Xu-Friedman, M A; Regehr, W G

1999-01-01

Strontium can replace calcium in triggering neurotransmitter release, although peak release is reduced and the duration of release is prolonged. Strontium has therefore become useful in probing release, but its mechanism of action is not well understood. Here we study the action of strontium at the granule cell to Purkinje cell synapse in mouse cerebellar slices. Presynaptic residual strontium levels were monitored with fluorescent indicators, which all responded to strontium (fura-2, calcium orange, fura-2FF, magnesium green, and mag-fura-5). When calcium was replaced by equimolar concentrations of strontium in the external bath, strontium and calcium both entered presynaptic terminals. Contaminating calcium was eliminated by including EGTA in the extracellular bath, or by loading parallel fibers with EGTA, enabling the actions of strontium to be studied in isolation. After a single stimulus, strontium reached higher peak free levels than did calcium (approximately 1.7 times greater), and decayed more slowly (half-decay time 189 ms for strontium and 32 ms for calcium). These differences in calcium and strontium dynamics are likely a consequence of greater strontium permeability through calcium channels, lower affinity of the endogenous buffer for strontium, and less efficient extrusion of strontium. Measurements of presynaptic divalent levels help to explain properties of release evoked by strontium. Parallel fiber synaptic currents triggered by strontium are smaller in amplitude and longer in duration than those triggered by calcium. In both calcium and strontium, release consists of two components, one more steeply dependent on divalent levels than the other. Strontium drives both components less effectively than does calcium, suggesting that the affinities of the sensors involved in both phases of release are lower for strontium than for calcium. Thus, the larger and slower strontium transients account for the prominent slow component of release triggered by strontium. PMID:10096899

Expression of the high capacity calcium-binding domain of calreticulin increases bioavailable calcium stores in plants

NASA Technical Reports Server (NTRS)

Wyatt, Sarah E.; Tsou, Pei-Lan; Robertson, Dominique; Brown, C. S. (Principal Investigator)

2002-01-01

Modulation of cytosolic calcium levels in both plants and animals is achieved by a system of Ca2+-transport and storage pathways that include Ca2+ buffering proteins in the lumen of intracellular compartments. To date, most research has focused on the role of transporters in regulating cytosolic calcium. We used a reverse genetics approach to modulate calcium stores in the lumen of the endoplasmic reticulum. Our goals were two-fold: to use the low affinity, high capacity Ca2+ binding characteristics of the C-domain of calreticulin to selectively increase Ca2+ storage in the endoplasmic reticulum, and to determine if those alterations affected plant physiological responses to stress. The C-domain of calreticulin is a highly acidic region that binds 20-50 moles of Ca2+ per mole of protein and has been shown to be the major site of Ca2+ storage within the endoplasmic reticulum of plant cells. A 377-bp fragment encoding the C-domain and ER retention signal from the maize calreticulin gene was fused to a gene for the green fluorescent protein and expressed in Arabidopsis under the control of a heat shock promoter. Following induction on normal medium, the C-domain transformants showed delayed loss of chlorophyll after transfer to calcium depleted medium when compared to seedlings transformed with green fluorescent protein alone. Total calcium measurements showed a 9-35% increase for induced C-domain transformants compared to controls. The data suggest that ectopic expression of the calreticulin C-domain increases Ca2+ stores, and that this Ca2+ reserve can be used by the plant in times of stress.

Dietary supplementation with flaxseed mucilage alone or in combination with calcium in dogs: effects on apparent digestibility of fat and energy and fecal characteristics.

PubMed

Nybroe, S; Astrup, A; Bjørnvad, C R

2016-12-01

In humans, dietary supplementation with flaxseed mucilage and calcium decrease apparent digestibility of fat and energy. These supplements could prove useful for weight management in dogs. To examine dry matter, energy and fat apparent digestibility, and fecal characteristics following dietary flaxseed mucilage supplementation alone or in combination with calcium. A single-blinded crossover feeding trial was conducted on 11 privately owned dogs. During three consecutive 14-day periods, dogs where fed commercial dog food supplemented with potato starch (control diet), flaxseed mucilage or flaxseed mucilage and calcium. Feces from the past 2 days of each period were collected for analysis. Owners recorded fecal score (1-7: 1=very hard/dry feces, 2-3=ideal and 7=diarrhea). Apparent digestibility of fat was lower in both flaxseed mucilage diet (94.5±0.8%), and flaxseed mucilage and calcium diet (92.9±0.9%) compared with control diet (96.9±0.2%, P<0.0001) with fat digestibility in flaxseed mucilage and calcium diet being significantly lower than the diet supplemented with only flaxseed mucilage. Dry matter and energy digestibility was not significantly affected by diet. Fecal wet weight, dry weight and dry matter percentage was not affected by diet despite a higher fecal score for test diets (3.7±0.3) compared with control (2.8±0.2, P<0.007). In dogs, flaxseed mucilage decreased fat apparent digestibility and this effect was enhanced when combined with calcium. Dry matter and energy apparent digestibility was not affected. Decreased fecal quality may limit the acceptable level of supplementation. Further studies on incorporating flaxseed mucilage in pet food products for weight management are needed.

Calcium, phosphorus and protein levels as factors in the distribution of the pheasant

USGS Publications Warehouse

Dale, F.H.; DeWitt, J.B.

1958-01-01

Summary of work on pheasant nutrition conducted since 1949 at the Patuxent Research Refuge. Pheasant chicks fed experimental diets failed to develop normally on protein levels of 15 and 18%. With 22% protein they grew at a reduced rate as compared to those on 28%. Protein level of the reproductive diet was shown to be important; low production of eggs and young resulted from levels below 25%. Calcium was found to be even more critical than protein level for reproduction; birds on a winter diet that furnished 145 mg./kg. per day had poor reproductive success the following spring. About 600 mg./kg. of Ca per day was necessary in the reproduction diet. Birds on an intermediate level of Ca (about 0.5% of diet) showed evidence of cumulative deficiency. It was concluded that pheasants receiving levels of Ca no higher than 0.5% in nature might display 'straggling failure' such as has been observed in several midwestern areas.

Absorption of Levothyroxine When Coadministered with Various Calcium Formulations

PubMed Central

Zamfirescu, Isabelle

2011-01-01

Background Calcium carbonate is a commonly used dietary supplement and has been shown to interfere with levothyroxine absorption. However, calcium citrate, which is also used for supplementation purposes, has not been studied previously and calcium acetate, which is used to treat hyperphosphatemia in renal failure, has been reported to show little or no interference with levothyroxine absorption in a retrospective pharmacoepidemiologic study. We aimed to compare the effect of these three calcium formulations on levothyroxine absorption. Materials and Methods The study was conducted in eight healthy, euthyroid adults. We performed single-dose pharmacokinetic studies in which we measured levothyroxine absorption when given alone or when coadministered with calcium carbonate, calcium citrate, or calcium acetate in doses containing 500 mg elemental calcium. Serum thyroxine was measured at intervals over a 6-hour period after ingestion of the study drugs. Results Coadministration of each of the three calcium preparations significantly reduced levothyroxine absorption by about 20%–25% compared with levothyroxine given alone. Conclusions Contrary to a prior report, our data suggest that calcium acetate interferes with levothyroxine absorption in a manner similar to that seen with calcium carbonate and calcium citrate. Although the effect of calcium is modest compared with some other medications previously studied, hypothyroid patients should be cautioned to take their levothyroxine well-separated from all of these calcium formulations. PMID:21595516

Effects of atorvastatin and losartan on monocrotaline-induced pulmonary artery remodeling in rats.

PubMed

Xie, Liangdi; Lin, Peisen; Xie, Hong; Xu, Changsheng

2010-01-01

Structural remodeling of pulmonary artery plays an important role in maintaining sustained pulmonary arterial hypertension (PAH). The anti-remodeling effects of statins have been reported in systemic hypertension. In this study, we studied the effects of atovastatin (Ato) or losartan (Los) in monocrotaline (MCL)-induced pulmonary artery remodeling using a rat model. Forty Sprague-Dawley (SD) rats were randomly assigned into four groups (n = 10): normal control (Ctr), PAH, PAH treated with Los, and PAH treated with Ato. We found that in the Los- or Ato-treated group, the mean pulmonary arterial pressure, right heart hypertrophy index, ratio of wall/lumen thickness (WT%), as well as the wall/lumen area (WA%) were significantly reduced compared to the PAH group. Also in pulmonary arteries dissected from rats in the Ato- or Los-treated group, in both mRNA and protein levels, the expression of α1C subunit of voltage-gated calcium channel (Ca(v)α1c) was downregulated, while sarcoplasmic/endoplasmic reticulum calcium-ATPase (SERCA-2a) and inositol 1,4,5 triphosphate receptor 1 (IP3R-1) upregulated. However, the mRNA level of RyR-3 subunit of calcium regulating channel was increased, whereas its protein level was reduced in the treated groups. Our results suggest that atorvastatin or losartan may regress the remodeling of the pulmonary artery in pulmonary hypertensive rats, with differential expression of calcium regulating channels.

Calcium Overload Accelerates Phosphate-Induced Vascular Calcification Via Pit-1, but not the Calcium-Sensing Receptor.

PubMed

Masumoto, Asuka; Sonou, Tomohiro; Ohya, Masaki; Yashiro, Mitsuru; Nakashima, Yuri; Okuda, Kouji; Iwashita, Yuko; Mima, Toru; Negi, Shigeo; Shigematsu, Takashi

2017-07-01

Vascular calcification (VC) is a risk factor of cardiovascular and all-cause mortality in patients with chronic kidney disease (CKD). CKD-mineral and bone metabolism disorder is an important problem in patients with renal failure. Abnormal levels of serum phosphate and calcium affect CKD-mineral and bone metabolism disorder and contribute to bone disease, VC, and cardiovascular disease. Hypercalcemia is a contributing factor in progression of VC in patients with CKD. However, the mechanisms of how calcium promotes intracellular calcification are still unclear. This study aimed to examine the mechanisms underlying calcium-induced calcification in a rat aortic tissue culture model. Aortic segments from 7-week-old male Sprague-Dawley rats were cultured in serum-supplemented medium for 10 days. We added high calcium (HiCa; calcium 3.0 mM) to high phosphate (HPi; phosphate 3.8 mM) medium to accelerate phosphate and calcium-induced VC. We used phosphonoformic acid and the calcimimetic R-568 to determine whether the mechanism of calcification involves Pit-1 or the calcium-sensing receptor. Medial VC was significantly augmented by HPi+HiCa medium compared with HPi alone (300%, p＜0.05), and was associated with upregulation of Pit-1 protein. Pit-1 protein concentrations in HPi+HiCa medium were greater than those in HPi medium. Phosphonoformic acid completely negated the augmentation of medial VC induced by HPi+HiCa. R-568 had no additive direct effect on medial VC. These results indicated that exposure to HPi+HiCa accelerates medial VC, and this is mediated through Pit-1, not the calcium-sensing receptor.

Significance of serum levels of vitamin D and some related minerals in breast cancer patients

PubMed Central

Abdelgawad, Iman A; El-Mously, Rawya H; Saber, Magdy M; Mansour, Ossama A; Shouman, Samia A

2015-01-01

Vitamin D and calcium are involved in a wide range of proliferation, apoptosis and cell signaling activities in the body. Suboptimal concentrations may lead to cancer development. The role of phosphate in cancer metabolism is particularly relevant in breast cancer while, magnesium deficiency favors DNA mutations leading to carcinogenesis. Objectives: To determine serum levels of vitamin D, calcium, phosphorus, magnesium, and parathormone in female breast cancer patients and to assess their association with some prognostic factors in breast cancer. Design and methods: This study is done on 98 newly diagnosed female breast cancer patients and 49 age matched apparently healthy female volunteers as controls. Serum samples from all patients and controls were subjected to 25-OH Vit D, calcium, phosphorus, magnesium, and parathormone measurements. Results: In the breast cancer group, the median serum levels of 25-OH Vit D were 15 ng/ml, while it was 21 ng/ml in the control group. Levels of 25-OH Vit D and other tested minerals were significantly lower while calcium:magnesium (Ca:Mg) ratio, and calcium:phosphorus (Ca:P) ratio were significantly higher in the breast cancer group. Significant negative correlation was detected between phosphorus and calcium, ionized calcium , calcium magnesium ratio, and calcium phosphorus ratio. Conclusion: It is not only the deficient levels of Vit D and other related minerals, but the combination of the abnormal levels of all the studied parameters that might contribute to the development of cancer. Further studies with larger number of patient are needed. PMID:26097595

On the role of calcium in adrenocorticotropin-induced changes in mitochondrial pregnenolone synthesis.

PubMed

Farese, R V; Prudente, W J

1978-10-01

The importance of calcium in the ACTH-induced increase in adrenal mitochondrial pregnenolone synthesis was evaluated. In mitochondria prepared in the absence of EDTA and albumin, calcium enhanced the binding of cholesterol to cytochrome P-450 and subsequent pregnenolone synthesis. Although these effects of calcium were slightly greater in control than in ACTH-treated mitochondria, a sizeable effect of ACTH remained even at high calcium levels (500 micron). In mitochondria prepared from adrenals homogenized in fluid containing EDTA and albumin, ACTH-induced effects on pregnenolone synthesis were relatively poor unless calcium was added to the incubation mixture. High concentrations of added calcium (500 micron or greater) obviated the need for the labile protein required for ACTH-induced effects in intact mitochondria, presumably by disrupting mitochondria and allowing an "unrestrained" interaction of cholesterol with cytochrome P-450. Thus, cholesterol-rich mitochondria from ACTH plus cycloheximide-treated rats produced large amounts of pregnenolone when high (probably unphysiological) calcium concentrations were present. The present findings suggest that calcium is required at the mitochondrial level for ACTH-induced effects on pregnenolone synthesis, and the reported ACTH-induced increase in intraadrenal calcium may thus amplify the effects of ACTH on steroidogenesis. However, it seems unlikely that calcium is the agent primarily responsible for mediating the ACTH-induced steroidogenic effect at the mitochondrial level.

Serum calcium changes and risk of type 2 diabetes mellitus in Asian population.

PubMed

Suh, Sunghwan; Bae, Ji Cheol; Jin, Sang-Man; Jee, Jae Hwan; Park, Mi Kyoung; Kim, Duk Kyu; Kim, Jae Hyeon

2017-11-01

We examined the association between changes in serum calcium levels with the incidence of type 2 diabetes mellitus (T2DM) in apparently healthy South Korean subjects. A retrospective longitudinal analysis was conducted with subjects who had participated in comprehensive health check-ups at least four times over a 7-year period (between 2006 and 2012). In total, 23,121 subjects were categorized into tertiles based on changes in their albumin-adjusted serum calcium levels. Multivariate Cox regression models were fitted to assess the association between changes in serum calcium levels during follow-up and the relative risk of diabetes incidence. After a median follow-up of 57.4months, 1,929 (8.3%) new cases of T2DM occurred. Simple linear regression analysis showed serum calcium level changes correlated positively with changes in HbA1c and fasting plasma glucose (FPG) levels (B=5.72, p<0.001 for FPG; B=0.13, p<0.001 for HbA1c). An increase in albumin-adjusted serum calcium levels during follow-up was related to an increased risk of T2DM. After adjustment for potential confounders, the risk of T2DM was 1.6 times greater for subjects whose albumin-adjusted serum calcium levels were in the highest change tertile during follow-up than for subjects whose levels were in the lowest tertile (HR 1.65, 95% CI 1.44-1.88, P<0.001). The elevation of albumin-adjusted serum calcium levels was associated with an increased risk of T2DM, independent of baseline glycemic status. Copyright © 2017 Elsevier B.V. All rights reserved.

Hypocalcaemia, Alcohol Drinking and Viroimmune Responses in ART Recipients

PubMed Central

Míguez, María José; Burbano-Levy, Ximena; Carmona, Talita; Quiros, Clery; Thompson, Michelle; Lewis, John; Asthana, Desharatan; Rodríguez, Allan; Valiathan, Ranjini; Malow, Robert

2013-01-01

Metabolic perturbations associated with HIV and antiretroviral therapies are widespread. Unfortunately, research has predominantly focused in cardiometabolic problems, neglecting other important areas. In fact, the immune-calcium-skeletal interface has been understudied despite its potential relevance in people living with HIV (PLWH). Using a case-control methodology, 200 PLWH receiving medical care were enrolled and stratified according to hazardous vs. non-hazardous alcohol intake (HAU vs. non-HAU) and calcium (Ca) levels by analyzing baseline data. The group was chosen to represent relatively "pure" HAU with minimal drug use and no psychiatric diagnoses. With these narrow parameters in place, we found evidence that HAU significantly increases TNF-α levels compared to Non-HAU (2.8±0.6 vs. 1.9±0.3 pg/ml, p=0.05) and decreases blood Ca levels (9±0.6 vs. 9.4 ±0.5, p=0.03). Our analyses also suggest that chronic inflammation, as indicated by increased TNF-α levels, is associated with hypocalcemia (hypoCa <8.6). Despite the limited prevalence of hypoCa, these findings are clinically significant given that hypoCA PLWH exhibited decreased CD4 (253±224 vs. 417.7±281, p=0.02), B cells (147±58 vs. 248±151 p=0.03) and NK cells (146.8±90 vs. 229±148, p=0.008) and elevated CD8 (902.5±438 vs. 699±510, p=0.09) compared to those with normal calcium. Furthermore, calcium effects on viral load were also evident with hypoCA exhibiting the highest loads (140,187±111 vs. 35622 ±7770 HIV copies, p=0.01). Multivariate analyses confirmed the significance of hypoCa in predicting viro-immune parameters. This paper provides the first evidence that hypoCa accounts for some of the variation in viroimmune measures in HAART recipients and suggests that hypoCa may be mediating alcohol’s deleterious effects. PMID:22857856

The relationship between sodium intake and some bone minerals and osteoporosis risk assessment instrument in postmenopausal women.

PubMed

Vafa, Mohammadreza; Soltani, Sepideh; Zayeri, Farid; Niroomand, Mahtab; Najarzadeh, Azadeh

2016-01-01

The results of the studies on the effects of sodium on bone metabolism have been inconsistent. There is no definitive answer to the question of whether sodium restriction can be associated with a lower incidence of osteoporosis. What reinforces the necessity of designing this study is the lack of findings with the approach of examining the effects of sodium on bone in our country. This was a cross-sectional study conducted on 185 retired female teachers aged 45 to 70. Sodium intake was evaluated using two methods: A 24-hour recall and a 12-hour urine sample. To assess bone health, ORAI index was calculated for each individual. Urinary calcium, phosphorus, potassium and serum vitamin D and PTH were measured as laboratory variables. To compare the general characteristics of the participants across tertiles of urinary sodium, the analysis of variance (ANOVA) was used for quantitative variables and the Chi-square test for categorical variables. Phosphorous, calcium and potassium urinary excretion rate increased with the increase in urinary sodium (p<0.05). However, the changes in serum vitamin D, and PTH levels across tertiles of urinary sodium were not significant. Changes in urinary sodium levels were not significant (p=0.933) in ORAI groups (sorted by rating). The relationship between urinary calcium and sodium was apparent in low calcium intake (r=0.415, p<0.001), but not in higher calcium intake (r=0.144, p=0.177). Although urinary calcium and potassium increased with the increase in sodium intake, no relationship was found between sodium and ORAI.

Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer.

PubMed

Kuga, Milton Carlos; Duarte, Marco Antonio Hungaro; Sant'anna-Júnior, Arnaldo; Keine, Kátia Cristina; Faria, Gisele; Dantas, Andrea Abi Rached; Guiotti, Flávia Angélica

2014-06-01

Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. The flowability test was performed according to the ISO 6876:2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (α=5%). In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential.

Novel calcium infusion regimen after parathyroidectomy for renal hyperparathyroidism

PubMed Central

Tan, Jih Huei; Tan, Henry Chor Lip; Arulanantham, Sarojah A/P

2017-01-01

Abstract Aim Calcium infusion is used after parathyroid surgery for renal hyperparathyroidism to treat postoperative hypocalcaemia. We compared a new infusion regimen to one commonly used in Malaysia based on 2003 K/DOQI guidelines. Methods Retrospective data on serum calcium and infusion rates was collected from 2011–2015. The relationship between peak calcium efflux (PER) and time was determined using a scatterplot and linear regression. A comparison between regimens was made based on treatment efficacy (hypocalcaemia duration, total infusion amount and time) and calcium excursions (outside target range, peak and trough calcium) using bar charts and an unpaired t‐test. Results Fifty‐one and 34 patients on the original and new regimens respectively were included. Mean PER was lower (2.16 vs 2.56 mmol/h; P = 0.03) and occurred earlier (17.6 vs 23.2 h; P = 0.13) for the new regimen. Both scatterplot and regression showed a large correlation between PER and time (R‐square 0.64, SE 1.53, P < 0.001). The new regimen had shorter period of hypocalcaemia (28.9 vs 66.4 h, P = 0.04), and required less calcium infusion (67.7 vs 127.2 mmol, P = 0.02) for a shorter duration (57.3 vs 102.9 h, P = 0.001). Calcium excursions, peak and trough calcium were not significantly different between regimens. Early postoperative high excursions occurred when the infusion was started in spite of elevated peri‐operative calcium levels. Conclusion The new infusion regimen was superior to the original in that it required a shorter treatment period and resulted in less hypocalcaemia. We found that early aggressive calcium replacement is unnecessary and raises the risk of rebound hypercalcemia. PMID:26952689

Aminoglycoside antibiotics as a tool for the study of the biological role of calcium ions. Historical overview.

PubMed

Corrado, A P; de Morais, I P; Prado, W A

1989-01-01

Beginning with the pioneering work of Vital-Brazil and Corrado (1957), which suggested a possible interaction between aminoglycoside antibiotics (AGA) and calcium ions at the neuromuscular junction, the authors review the studies that demonstrated the existence of a competitive antagonism between AGA and calcium ions. In view of the low liposolubility of AGA and their inability to cross biological membranes, this antagonism seems to occur exclusively at calcium-binding sites at the level of the outer opening of calcium channels of the N-subtype, which are also the sites of interaction of omega-conotoxin. Being highly water soluble, AGA are easily removed from their binding sites with a consequent rapid reversal of their effects, a factor of primary importance to explain their wide use as tools in the pharmacological analysis of the study of the biological role of calcium ion on the membrane's outer surface. This use has advantages over the use of inorganic di- and trivalent cations such as Mg2+, Mn2+, Cd2+, Ni2+, La3+, etc., since the latter, though they are considered to be the most specific competitive antagonists of calcium ions, may induce biphasic effects due to their ability to cross the membranes and replace calcium and/or increase intracellular calcium concentration. The performance of AGA is also superior when compared with the so-called "specific" organic calcium antagonists--verapamil and nifedipine derivatives--since the latter, in addition to inducing possible biphasic effects, antagonize calcium in a non-competitive manner. Finally, the authors remark that AGA-Ca2+ antagonism relevance is not limited only to basic aspects and that it may have therapeutic implications since it provides alternatives for reducing the toxic adverse effects of this important group of antibiotics.

Ion release and mechanical properties of calcium silicate and calcium hydroxide materials used for pulp capping.

PubMed

Natale, L C; Rodrigues, M C; Xavier, T A; Simões, A; de Souza, D N; Braga, R R

2015-01-01

To compare the ion release and mechanical properties of a calcium hydroxide (Dycal) and two calcium silicate (MTA Angelus and Biodentine) cements. Calcium and hydroxyl ion release in water from 24-h set cements were calculated from titration with HCl (n = 3). Calcium release after 7, 14, 21 and 28 days at pH 5.5 and 7.0 was measured using ICP-OES (n = 6). Flexural strength (FS) and modulus (E) were tested after 48-h storage, and compressive strength (CS) was tested after 48 h and 7 days (n = 10). Ion release and mechanical data were subjected to anova/Tukey and Kruskal-Wallis/Mann-Whitney tests, respectively (α = 0.05). Titration curves revealed that Dycal released significantly fewer ions in solution than calcium silicates (P < 0.001). Calcium release remained constant at pH 7.0, whilst at pH 5.5, it dropped significantly by 24% after 21 days (P < 0.05). At pH 5.5, MTA Angelus released significantly more calcium than Dycal (P < 0.01), whilst Biodentine had superior ion release than Dycal at pH 7.0 (P < 0.01). Biodentine had superior flexural strength, flexural modulus and compressive strength than the other cements, whilst MTA Angelus had higher modulus than Dycal (P < 0.001). Immediate calcium and hydroxyl ion release in solution was significantly lower for Dycal. In general, all materials released constant calcium levels over 28 days, but release from Dycal was significantly lower than Biodentine and MTA Angelus depending on pH conditions. Biodentine had substantially higher strength and modulus than MTA Angelus and Dycal, both of which demonstrated low stress-bearing capabilities. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Association Between Serum Calcium Level and Extent of Bleeding in Patients With Intracerebral Hemorrhage.

PubMed

Morotti, Andrea; Charidimou, Andreas; Phuah, Chia-Ling; Jessel, Michael J; Schwab, Kristin; Ayres, Alison M; Romero, Javier M; Viswanathan, Anand; Gurol, M Edip; Greenberg, Steven M; Anderson, Christopher D; Rosand, Jonathan; Goldstein, Joshua N

2016-11-01

Calcium is a key cofactor of the coagulation cascade and may play a role in the pathophysiology of intracerebral hemorrhage (ICH). To investigate whether a low serum calcium level is associated with an increase in the extent of bleeding in patients with ICH as measured by baseline hematoma volume and risk of hematoma expansion. Prospective cohort study of 2103 consecutive patients with primary ICH ascertained during the period between 1994 and 2015 at an academic medical center. The statistical analysis was performed in January 2016. Total calcium level was measured on admission, and hypocalcemia was defined as a serum calcium level of less than 8.4 mg/dL. Baseline and follow-up hematoma volumes, detected by noncontrast computed tomography, were measured using a computer-assisted semiautomatic analysis. Hematoma expansion was defined as an increase of more than 30% or 6 mL from baseline ICH volume. Associations between serum calcium level and baseline hematoma volume and between serum calcium level and ICH expansion were investigated in multivariable linear and logistic regression models, respectively. A total of 2123 patients with primary ICH were screened, and 2103 patients met the inclusion criteria (mean [SD] age, 72.7 [12.5] years; 54.3% male patients), of whom 229 (10.9%) had hypocalcemia on admission. Hypocalcemic patients had a higher median baseline hematoma volume than did normocalcemic patients (37 mL [IQR, 15-72 mL] vs 16 mL [IQR, 6-44 mL]; P < .001). Low calcium levels were independently associated with higher baseline ICH volume (β = -0.13, SE = .03, P < .001). A total of 1393 patients underwent follow-up noncontrast computed tomography and were included in the ICH expansion analysis. In this subgroup, a higher serum calcium level was associated with reduced risk of ICH expansion (odds ratio, 0.55 [95% CI, 0.35-0.86]; P = .01), after adjusting for other confounders. Hypocalcemia correlates with the extent of bleeding in patients with ICH. A low calcium level may be associated with a subtle coagulopathy predisposing to increased bleeding and might therefore be a promising therapeutic target for acute ICH treatment trials.

The pmr gene, encoding a Ca2+-ATPase, is required for calcium and manganese homeostasis and normal development of hyphae and conidia in Neurospora crassa.

PubMed

Bowman, Barry J; Abreu, Stephen; Johl, Jessica K; Bowman, Emma Jean

2012-11-01

The pmr gene is predicted to encode a Ca(2+)-ATPase in the secretory pathway. We examined two strains of Neurospora crassa that lacked PMR: the Δpmr strain, in which pmr was completely deleted, and pmr(RIP), in which the gene was extensively mutated. Both strains had identical, complex phenotypes. Compared to the wild type, these strains required high concentrations of calcium or manganese for optimal growth and had highly branched, slow-growing hyphae. They conidiated poorly, and the shape and size of the conidia were abnormal. Calcium accumulated in the Δpmr strains to only 20% of the wild-type level. High concentrations of MnCl(2) (1 to 5 mM) in growth medium partially suppressed the morphological defects but did not alter the defect in calcium accumulation. The Δpmr Δnca-2 double mutant (nca-2 encodes a Ca(2+)-ATPase in the plasma membrane) accumulated 8-fold more calcium than the wild type, and the morphology of the hyphae was more similar to that of wild-type hyphae. Previous experiments failed to show a function for nca-1, which encodes a SERCA-type Ca(2+)-ATPase in the endoplasmic reticulum (B. J. Bowman, S. Abreu, E. Margolles-Clark, M. Draskovic, and E. J. Bowman, Eukaryot. Cell 10:654-661, 2011). The pmr(RIP) Δnca-1 double mutant accumulated small amounts of calcium, like the Δpmr strain, but exhibited even more extreme morphological defects. Thus, PMR can apparently replace NCA-1 in the endoplasmic reticulum, but NCA-1 cannot replace PMR. The morphological defects in the Δpmr strain are likely caused, in part, by insufficient concentrations of calcium and manganese in the Golgi compartment; however, PMR is also needed to accumulate normal levels of calcium in the whole cell.

Allosteric Effects of the Anti-Psychotic Drug Trifluoperazine on the Energetics of Calcium Binding by Calmodulin

PubMed Central

Feldkamp, Michael D.; O'Donnell, Susan E.; Yu, Liping; Shea, Madeline A.

2010-01-01

Trifluoperazine (TFP; Stelazine™) is an antagonist of calmodulin (CaM), an essential regulator of calcium-dependent signal transduction. Reports differ regarding whether, or where, TFP binds to apo CaM. Three crystallographic structures (1CTR, 1A29, 1LIN) show TFP bound to (Ca2+)4-CaM in ratios of 1, 2 or 4 TFP per CaM. In all of these, CaM domains adopt the “open” conformation seen in CaM-kinase complexes having increased calcium affinity. Most reports suggest TFP also increases calcium affinity of CaM. To compare TFP binding to apo CaM and (Ca2+)4-CaM, and explore differential effects on the N- and C-domains of CaM, stoichiometric TFP titrations of CaM were monitored by 15N-HSQC NMR. Two TFP bound to apo CaM, while four bound to (Ca2+)4-CaM. In both cases, the preferred site was in the C-domain. During the titrations, biphasic responses for some resonances suggested inter-site interactions. TFP-binding sites in apo CaM appeared distinct from those in (Ca2+)4-CaM. In equilibrium calcium titrations at defined ratios of TFP:CaM, TFP reduced calcium affinity at most levels tested; this is similar to the effect of many IQ-motifs on CaM. However, at the highest level tested, TFP raised the calcium affinity of the N-domain of CaM. A model of conformational switching is proposed to explain how TFP can exert opposing allosteric effects on calcium affinity by binding to different sites in the “closed”, “semi-open” and “open” domains of CaM. In physiological processes, apo CaM, as well as (Ca2+)4-CaM, needs to be considered a potential target of drug action. PMID:20544963

The effect of habitat geology on calcium intake and calcium status of wild rodents.

PubMed

Shore, R F; Balment, R J; Yalden, D W

1991-12-01

Calcium is essential for normal physiological function, reproduction and growth in mammals but its distribution in the natural environment is heterogeneous. Spatial variation in calcium soil content is especially marked in the Peak District, United Kingdom, where both calcium-rich limestone and calcium-poor gritstone rock types occur. Wood mice Apodemus sylvaticus (L) and bank voles Clethrionomys glareolus (Schreber 1780) from limestone areas had significantly higher calcium concentrations in stomach contents and in faeces compared with their counterparts from gritstone areas. Calcium status was assessed from serum calcium concentration, femur weight, ash content of the body, calcium concentration in the femur and body ash. There was no significant difference in serum calcium concentration, femur calcium concentration and body ash calcium concentration between animals from the limestone and the gritstone. However, on the limestone, bank voles, but not wood mice, had significantly heavier femora and a greater proportion of ash in the body compared with their gritstone counterparts.

Calcium supplementation prevents endothelial cell activation: possible relevance to preeclampsia.

PubMed

Chen, Qi; Tong, Mancy; Wu, Man; Stone, Peter R; Snowise, Saul; Chamley, Lawrence W

2013-09-01

Preeclampsia is a leading cause of maternal and fetal mortality and morbidity. A hallmark of preeclampsia is endothelial cell dysfunction/activation in response to 'toxins' from the placenta. Necrotic trophoblastic debris (NTD) is one possible placental toxin and other activators of endothelial cells include inflammatory cytokines. Calcium supplementation appears to protect 'at-risk' women from developing preeclampsia but how is unclear. Placental explants were cultured with interleukin-6 (IL-6) in varied concentrations of calcium. The resultant trophoblastic debris was exposed to endothelial cells. Endothelial cells were exposed to activators including NTD, IL-6, and preeclamptic sera in the presence of varied concentrations of calcium and activation monitored by quantifying cell surface markers by ELISA. Raising the levels of calcium did not prevent the IL-6-induced shedding of NTD from placental explants but did prevent the activation of endothelial cells in response to IL-6, preeclamptic sera, or NTD. Reducing the level of calcium directly induced the activation of endothelial cells. Inhibiting nitric oxide synthetase ablated the ability of high calcium levels to protect endothelial cell activation. The activity of endothelial cell nitric oxide synthetase was blocked with L-N-nitroarginine methyl ester. Our results demonstrate calcium levels do not affect the shedding of trophoblastic debris but are important to endothelial cell activation and supplemental calcium may reverse the activation of the endothelium in preeclamptic women. These results may in part explain the benefits of calcium supplementation in the reduction of risk for developing preeclampsia and provide in-vitro mechanistic support for the use of calcium supplementation in at-risk women.

Early prediction of post-thyroidectomy hypocalcemia by early parathyroid hormone measurement.

PubMed

Yetkin, Gurkan; Citgez, Bulent; Yazici, Pinar; Mihmanli, Mehmet; Sit, Erhan; Uludag, Mehmet

2016-01-01

Hypoparathyroidism is the most common complication of total thyroidectomy (TT). Postthyroidectomy hypocalcemia occurs 24 to 48 hours after the operation. It prolongs the length of hospital stay, even though transient in most cases. The aim of this study was to predetermine the patients who may develop postthyroidectomy hypocalcemia by using early postoperative serum intact parathormone (iPTH) and calcium (Ca2+) measurements, and to investigate the effects of early initiated oral calcium and vitamin D treatments on the development of transient hypocalcemia. Patients who underwent TT after initiation of the early iPTH measurement protocol in January 2013 were included into the study group (Group 1, n=202). The control group (Group 2) was composed of 72 patients who underwent TT before the protocol. Prior to the initiation of the protocol, Ca2+ was measured instead of iPTH. In the study group, the serum Ca2+ and iPTH levels were measured before surgery, and 1 and 24-hours after. A calcium level below 8 mg/dL was accepted as biochemical hypocalcaemia, and a iPTH level under 15pg/mL was accepted as hypoparathyroidism. In the study group, patients with below normal iPTH levels were treated with prophylactic oral calcium and vitamin D. In Group 1, 15.8% (n=32) of the patients had hypoparathyroidism on the 1h and 24 h iPTH measurements. There was no statistically difference with regard to PTH levels measured in the postoperative 1st hour and at the 24th hour (p= 0.078). Biochemical hypocalcaemia developed in 16 (7.9%) and 13 (18%) patients in Groups 1 and 2, respectively, 24 hours after thyroidectomy (p<0.05). Mean length of hospital stay was 2.17 and 3.26 days in the study and control groups (p<0.001). We believe that the measurement of iPTH levels one hour after thyroidectomy, when compared to levels at 24 hours after procedure, is a safe, reliable, and adequate method for the effective management of plausible postthyroidectomic hypocalcemia. It yields significantly shorter hospital stay periods. Calcium, Hypoparathyroidism, Postoperative complication, Total thyroidectomy.

Expressed ryanodine receptor can substitute for the inositol 1,4,5-trisphosphate receptor in Xenopus laevis oocytes during progesterone-induced maturation.

PubMed

Kobrinsky, E; Ondrias, K; Marks, A R

1995-12-01

Two structurally related forms of intracellular calcium release channels that can mediate the release of intracellular calcium have been identified: the ryanodine receptors (RyR) and the inositol 1,4,5-trisphosphate receptors (IP3R). Each channel responds to distinct pathways for activation. The IP3R is activated by IP3 and the RyR is thought to be activated by calcium or by another second messenger cADP ribose. It has been proposed that each type of channel subserves a specialized pool of intracellular calcium, and it is not understood why some cell types require more than one form of intracellular calcium release channel. The present study was designed to examine whether the RyR can substitute for the IP3R during oocyte maturation. IP3R expression was inhibited in Xenopus laevis oocytes using antisense oligonucleotides. These oocytes, with reduced levels of IP3R, demonstrated a marked delay in the time course of progesterone-induced maturation. The cloned skeletal muscle RyR1 was then expressed in X. laevis oocytes that were deficient in IP3R. Functional studies showed that the properties of the cloned RyR1, expressed in oocytes, were comparable to those of the native RyR1. X. laevis oocytes deficient in IP3R, but expressing RyR1, were able to undergo progesterone-induced maturation with a time course comparable to that seen in wild-type oocytes when caffeine was used to activate RyR and induce intracellular calcium release. These studies show that RyR1 can substitute for the IP3R as the intracellular calcium release channel required for Xenopus oocyte maturation and that intracellular calcium release is important for controlling the rate of progesterone-induced maturation.

Deficient ryanodine receptor S-nitrosylation increases sarcoplasmic reticulum calcium leak and arrhythmogenesis in cardiomyocytes.

PubMed

Gonzalez, Daniel R; Beigi, Farideh; Treuer, Adriana V; Hare, Joshua M

2007-12-18

Altered Ca(2+) homeostasis is a salient feature of heart disease, where the calcium release channel ryanodine receptor (RyR) plays a major role. Accumulating data support the notion that neuronal nitric oxide synthase (NOS1) regulates the cardiac RyR via S-nitrosylation. We tested the hypothesis that NOS1 deficiency impairs RyR S-nitrosylation, leading to altered Ca(2+) homeostasis. Diastolic Ca(2+) levels are elevated in NOS1(-/-) and NOS1/NOS3(-/-) but not NOS3(-/-) myocytes compared with wild-type (WT), suggesting diastolic Ca(2+) leakage. Measured leak was increased in NOS1(-/-) and NOS1/NOS3(-/-) but not in NOS3(-/-) myocytes compared with WT. Importantly, NOS1(-/-) and NOS1/NOS3(-/-) myocytes also exhibited spontaneous calcium waves. Whereas the stoichiometry and binding of FK-binding protein 12.6 to RyR and the degree of RyR phosphorylation were not altered in NOS1(-/-) hearts, RyR2 S-nitrosylation was substantially decreased, and the level of thiol oxidation increased. Together, these findings demonstrate that NOS1 deficiency causes RyR2 hyponitrosylation, leading to diastolic Ca(2+) leak and a proarrhythmic phenotype. NOS1 dysregulation may be a proximate cause of key phenotypes associated with heart disease.

Visualization of Calcium Dynamics in Kidney Proximal Tubules

PubMed Central

Szebényi, Kornélia; Füredi, András; Kolacsek, Orsolya; Csohány, Rózsa; Prókai, Ágnes; Kis-Petik, Katalin; Szabó, Attila; Bősze, Zsuzsanna; Bender, Balázs; Tóvári, József; Enyedi, Ágnes; Orbán, Tamás I.

2015-01-01

Intrarenal changes in cytoplasmic calcium levels have a key role in determining pathologic and pharmacologic responses in major kidney diseases. However, cell-specific delivery of calcium-sensitive probes in vivo remains problematic. We generated a transgenic rat stably expressing the green fluorescent protein-calmodulin–based genetically encoded calcium indicator (GCaMP2) predominantly in the kidney proximal tubules. The transposon-based method used allowed the generation of homozygous transgenic rats containing one copy of the transgene per allele with a defined insertion pattern, without genetic or phenotypic alterations. We applied in vitro confocal and in vivo two-photon microscopy to examine basal calcium levels and ligand- and drug-induced alterations in these levels in proximal tubular epithelial cells. Notably, renal ischemia induced a transient increase in cellular calcium, and reperfusion resulted in a secondary calcium load, which was significantly decreased by systemic administration of specific blockers of the angiotensin receptor and the Na-Ca exchanger. The parallel examination of in vivo cellular calcium dynamics and renal circulation by fluorescent probes opens new possibilities for physiologic and pharmacologic investigations. PMID:25788535

Assessment of fluoride-induced changes on physicochemical and structural properties of bone and the impact of calcium on its control in rabbits.

PubMed

Gopalakrishnan, Subarayan Bothi; Viswanathan, Gopalan

2012-03-01

Bone deformities caused by the chronic intake of large quantities of fluoride and the beneficial effect of calcium on its control have been studied for many years, but only limited data are available on the quantitative effect of fluoride intake and the beneficial impact of calcium on fluoride-induced changes in bone at the molecular level. It is necessary to determine the degree of fluoride-induced changes in bone at different levels of fluoride intake to evaluate the optimum safe intake level of fluoride for maintaining bone health and quality. The ameliorative effect of calcium at different dose levels on minimizing fluoride-induced changes in bone is important to quantify the amount of calcium intake necessary for reducing fluoride toxicity. Thirty rabbits, 2 months old, were divided into five groups. Group I animals received 1 mg/l fluoride and 0.11% calcium diet; groups II and III received 10 mg/l fluoride and diet with 0.11% or 2.11% calcium, respectively; and groups IV and V received 150 mg/l fluoride and diet with 2.11% or 0.11% calcium, respectively. Analysis of bone density, ash content, fluoride, calcium, phosphorus, and Ca:P molar ratio levels after 6 months of treatment indicated that animals that received high fluoride with low-calcium diet showed significant detrimental changes in physicochemical properties of bone. Animals that received fluoride with high calcium intake showed notable amelioration of the impact of calcium on fluoride-induced changes in bone. The degree of fluoride-induced characteristic changes in structural properties such as crystalline size, crystallinity, and crystallographic "c"-axis length of bone apatite cells was also assessed by X-ray diffraction and Fourier transform infrared studies. X-ray images showed bone deformity changes such as transverse stress growth lines, soft tissue ossification, and calcification in different parts of bones as a result of high fluoride accumulation and the beneficial role of calcium intake on its control.

Relationship between serum calcium and CA 19-9 levels in colorectal cancer

PubMed Central

Fuszek, Peter; Lakatos, Peter; Tabak, Adam; Papp, Janos; Nagy, Zsolt; Takacs, Istvan; Horvath, Henrik Csaba; Lakatos, Peter Laszlo; Speer, Gabor

2004-01-01

AIM: To examine the calcium metabolism of colorectal cancer (CRC) in patients with colorectal cancer and control patients. METHODS: Seventy newly diagnosed CRC patients were included. The healthy control group was age and gender matched (n = 32). Particular attention was devoted to the relationship between serum calcium of patients, and levels of AFP, CEA, carbohydrate antigen 19-9 (CA 19-9) (that could be considered as prognostic factors). Furthermore, the Ca-sensing receptor (CaSR) gene A986S polymorphism was investigated in these patients, as well as the relationship between different CaSR genotypes and the data stated above. RESULTS: A lower level of ionized calcium (also corrected for albumin) was found in the serum of CRC patients with normal 25 (OH) vitamin D levels. The ionized calcium concentration was inversely correlated with the serum level of CA 19-9. There was no difference in the distribution of CaSR genotypes, between CRC patients and general population. The genotypes did not correlate with other data examined. CONCLUSION: Based on these results, lower levels of serum calcium might be a pathogenic and prognostic factor in colorectal cancer. PMID:15222030

TMEM203 Is a Novel Regulator of Intracellular Calcium Homeostasis and Is Required for Spermatogenesis

PubMed Central

Shambharkar, Prashant B.; Bittinger, Mark; Latario, Brian; Xiong, ZhaoHui; Bandyopadhyay, Somnath; Davis, Vanessa; Lin, Victor; Yang, Yi; Valdez, Reginald; Labow, Mark A.

2015-01-01

Intracellular calcium signaling is critical for initiating and sustaining diverse cellular functions including transcription, synaptic signaling, muscle contraction, apoptosis and fertilization. Trans-membrane 203 (TMEM203) was identified here in cDNA overexpression screens for proteins capable of modulating intracellular calcium levels using activation of a calcium/calcineurin regulated transcription factor as an indicator. Overexpression of TMEM203 resulted in a reduction of Endoplasmic Reticulum (ER) calcium stores and elevation in basal cytoplasmic calcium levels. TMEM203 protein was localized to the ER and found associated with a number of ER proteins which regulate ER calcium entry and efflux. Mouse Embryonic Fibroblasts (MEFs) derived from Tmem203 deficient mice had reduced ER calcium stores and altered calcium homeostasis. Tmem203 deficient mice were viable though male knockout mice were infertile and exhibited a severe block in spermiogenesis and spermiation. Expression profiling studies showed significant alternations in expression of calcium channels and pumps in testes and concurrently Tmem203 deficient spermatocytes demonstrated significantly altered calcium handling. Thus Tmem203 is an evolutionarily conserved regulator of cellular calcium homeostasis, is required for spermatogenesis and provides a causal link between intracellular calcium regulation and spermiogenesis. PMID:25996873

Determination of serum calcium levels by 42Ca isotope dilution inductively coupled plasma mass spectrometry.

PubMed

Han, Bingqing; Ge, Menglei; Zhao, Haijian; Yan, Ying; Zeng, Jie; Zhang, Tianjiao; Zhou, Weiyan; Zhang, Jiangtao; Wang, Jing; Zhang, Chuanbao

2017-11-27

Serum calcium level is an important clinical index that reflects pathophysiological states. However, detection accuracy in laboratory tests is not ideal; as such, a high accuracy method is needed. We developed a reference method for measuring serum calcium levels by isotope dilution inductively coupled plasma mass spectrometry (ID ICP-MS), using 42Ca as the enriched isotope. Serum was digested with 69% ultrapure nitric acid and diluted to a suitable concentration. The 44Ca/42Ca ratio was detected in H2 mode; spike concentration was calibrated by reverse IDMS using standard reference material (SRM) 3109a, and sample concentration was measured by a bracketing procedure. We compared the performance of ID ICP-MS with those of three other reference methods in China using the same serum and aqueous samples. The relative expanded uncertainty of the sample concentration was 0.414% (k=2). The range of repeatability (within-run imprecision), intermediate imprecision (between-run imprecision), and intra-laboratory imprecision were 0.12%-0.19%, 0.07%-0.09%, and 0.16%-0.17%, respectively, for two of the serum samples. SRM909bI, SRM909bII, SRM909c, and GBW09152 were found to be within the certified value interval, with mean relative bias values of 0.29%, -0.02%, 0.10%, and -0.19%, respectively. The range of recovery was 99.87%-100.37%. Results obtained by ID ICP-MS showed a better accuracy than and were highly correlated with those of other reference methods. ID ICP-MS is a simple and accurate candidate reference method for serum calcium measurement and can be used to establish and improve serum calcium reference system in China.

In vitro evaluation of a new iterative reconstruction algorithm for dose reduction in coronary artery calcium scoring

PubMed Central

Allmendinger, Thomas; Kunz, Andreas S; Veyhl-Wichmann, Maike; Ergün, Süleyman; Bley, Thorsten A; Petritsch, Bernhard

2017-01-01

Background Coronary artery calcium (CAC) scoring is a widespread tool for cardiac risk assessment in asymptomatic patients and accompanying possible adverse effects, i.e. radiation exposure, should be as low as reasonably achievable. Purpose To evaluate a new iterative reconstruction (IR) algorithm for dose reduction of in vitro coronary artery calcium scoring at different tube currents. Material and Methods An anthropomorphic calcium scoring phantom was scanned in different configurations simulating slim, average-sized, and large patients. A standard calcium scoring protocol was performed on a third-generation dual-source CT at 120 kVp tube voltage. Reference tube current was 80 mAs as standard and stepwise reduced to 60, 40, 20, and 10 mAs. Images were reconstructed with weighted filtered back projection (wFBP) and a new version of an established IR kernel at different strength levels. Calcifications were quantified calculating Agatston and volume scores. Subjective image quality was visualized with scans of an ex vivo human heart. Results In general, Agatston and volume scores remained relatively stable between 80 and 40 mAs and increased at lower tube currents, particularly in the medium and large phantom. IR reduced this effect, as both Agatston and volume scores decreased with increasing levels of IR compared to wFBP (P < 0.001). Depending on selected parameters, radiation dose could be lowered by up to 86% in the large size phantom when selecting a reference tube current of 10 mAs with resulting Agatston levels close to the reference settings. Conclusion New iterative reconstruction kernels may allow for reduction in tube current for established Agatston scoring protocols and consequently for substantial reduction in radiation exposure. PMID:28607763

Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer

PubMed Central

KUGA, Milton Carlos; DUARTE, Marco Antonio Hungaro; SANT'ANNA-JÚNIOR, Arnaldo; KEINE, Kátia Cristina; FARIA, Gisele; DANTAS, Andrea Abi Rached; GUIOTTI, Flávia Angélica

2014-01-01

Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. Objective The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. Material and Methods The flowability test was performed according to the ISO 6876:2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (α=5%). Results In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. Conclusions The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential. PMID:25025558

Artefactual serum hyperkalaemia and hypercalcaemia in essential thrombocythaemia

PubMed Central

Howard, M; Ashwell, S; Bond, L; Holbrook, I

2000-01-01

Aim—To investigate possible abnormalities of serum potassium and calcium levels in patients with essential thrombocythaemia and significant thrombocytosis. Methods—24 cases of essential thrombocythaemia with significant thrombocytosis (platelet count > 700 x 109/litre) had serum potassium and calcium estimations performed at the time of maximum thrombocytosis before treatment, and at the time of low platelet count after treatment with cytoreductive drugs. Selected patients were further investigated with plasma sampling and estimation of ionised calcium and parathyroid hormone. Results—At the time of maximum thrombocytosis six patients had serum hyperkalaemia (> 5.5 mmol/litre) and five had serum hypercalcaemia (> 2.6 mmol/litre). Following treatment and reduction of the platelet count, hyperkalaemia resolved in all cases and hypercalcaemia in four of the five cases. Mean serum potassium and calcium concentrations were raised (p < 0.0001) at maximum thrombocytosis compared with the values when the platelet count was low. Serum potassium and calcium values were significantly correlated at all stages. Measurements on plasma consistently corrected the hyperkalaemia but not the hypercalcaemia. Serum hypercalcaemia was associated with raised ionised calcium and normal parathyroid hormone concentrations. Conclusions—Essential thrombocythaemia with significant thrombocytosis is associated with serum hyperkalaemia and hypercalcaemia. The probable mechanism of hypercalcaemia is the secretion of calcium in vitro from an excessive number of abnormally activated platelets. It is thus likely that the hypercalcaemia is an artefact, as is the hyperkalaemia. Key Words: thrombocythaemia • hypercalcaemia • hyperkalaemia PMID:10767824

Influence of calcium and phosphorus, lactose, and salt-to-moisture ratio on Cheddar cheese quality: proteolysis during ripening.

PubMed

Upreti, P; Metzger, L E; Hayes, K D

2006-02-01

Proteolysis in cheese is influenced by the state of proteins (protein-calcium-phosphate interactions), level of indigenous milk enzymes (plasmin), externally added milk-clotting enzymes (chymosin), and endogenous and exogenous enzymes from starter and non-starter lactic acid bacteria (NSLAB). The objective of this study was to determine how different levels of calcium (Ca) and phosphorus (P), residual lactose, and salt-to-moisture ratio (S/M) in cheese influence proteolysis during ripening. Eight cheeses with 2 levels of Ca and P (0.67 and 0.47% vs. 0.53 and 0.39%, respectively), 2 levels of lactose at pressing (2.4 vs. 0.78%), and 2 levels of S/M (6.4 vs. 4.8%) were manufactured. The cheeses were analyzed for changes in pH 4.6-soluble N, and starter and NSLAB counts during 48 wk of ripening. Cheeses at d 1 were also analyzed for residual chymosin, plasmin, and plasminogen activity. A significant increase in soluble N was observed during ripening for all the treatments. Cheeses with low Ca and P, low lactose, and low S/M treatments exhibited higher levels of proteolysis as compared to their corresponding high treatments. Differences in the rate of proteolysis for cheeses with different levels of Ca and P might be due to changes in protein conformation and differences in residual chymosin in the cheeses. Cheeses with low Ca and P were manufactured by lowering the pH at set and drain, which led to higher chymosin retention in cheeses with low Ca and P compared with high Ca and P. Differences in proteolysis between treatments with different levels of lactose were also partly attributed to residual chymosin activity. In all treatments, a major fraction of plasmin existed as plasminogen, indicating minimal contribution of plasmin to proteolysis in Cheddar cheeses. The number of starter bacteria, in all treatments, decreased significantly during ripening. However, the decrease was larger in the case of high S/M treatments compared with low S/M treatments. In contrast, the number of NSLAB increased during ripening, and low S/M cheeses had higher counts compared with high S/M cheeses. The differences in proteolysis due to S/M were partially attributed to changes in protein conformation or bacterial proteolytic activity.

Genotypic to expression profiling of bovine calcium channel, voltage-dependent, alpha-2/delta subunit 1 gene, and their association with bovine mastitis among Frieswal (HFX Sahiwal) crossbred cattle of Indian origin.

PubMed

Deb, Rajib; Singh, Umesh; Kumar, Sushil; Kumar, Arun; Singh, Rani; Sengar, Gyanendra; Mann, Sandeep; Sharma, Arjava

2014-04-03

Calcium channel, voltage-dependent, alpha-2/delta subunit 1 (CACNA2D1) gene is considered to be an important noncytokine candidate gene influencing mastitis. Scanty of reports are available until today regarding the role play of CACNA2D1 gene on the susceptibility of bovine mastitis. We interrogated the CACNA2D1 G519663A [A>G] SNP by PCR-RFLP among two hundreds Frieswal (HF X Sahiwal) crossbred cattle of Indian origin. Genotypic frequency of AA (51.5, n=101) was comparatively higher than AG (35, n=70) and GG (14.5, n=29). Association of Somatic cell score (SCS) with genotypes revealed that, GG genotypes showing lesser count (less susceptible to mastitis) compare to AA and AG. Relative expression of CACNA2D1 transcript (in milk samples) was significantly higher among GG than AG and AA. Further we have also isolated blood sample from the all groups and PBMCs were cultured from each blood sample as per the standard protocol. They were treated with Calcium channel blocker and the expression level of the CACNA2D1 gene was evaluated by Real Time PCR. Results show that expression level decline in each genotypic group after treatment and expression level of GG are again significantly higher than AA and AG. Thus, it may be concluded that GG genotypic animals are favorable for selecting disease resistant breeds.

Arterial Structure and Function in Mild Primary Hyperparathyroidism Is Not Directly Related to Parathyroid Hormone, Calcium, or Vitamin D

PubMed Central

Ring, Margareta; Farahnak, Parastou; Gustavsson, Tomas; Nilsson, Inga-Lena; Eriksson, Maria J.; Caidahl, Kenneth

2012-01-01

Objective Elevated levels of calcium and parathyroid hormone (PTH), characteristics of primary hyperparathyroidism (PHPT), may be associated with cardiovascular morbidity and mortality in the general population. We evaluated the possible vascular effects of these risk factors in patients with mild PHPT by using standard methods and new imaging techniques. Design A prospective case-control study. Subjects and Methods Forty-eight patients with mild PHPT without any known cardiovascular risk factors were studied at baseline and at one year after parathyroidectomy (PTX) in comparison with 48 healthy age- and gender-matched controls. We measured biochemical variables, augmentation index (AIx), aortic pulse wave velocity (PWVao), radial (IMTrad) and common carotid artery (IMTcca) intima media thicknesses, and the grayscale median (IM-GSM) of the latter. Results No significant differences were observed between PHPT patients and controls at baseline for AIx (28.6±12.2 vs. 27.7±12.8%), IMTrad (0.271±0.060 vs. 0.255±0.053 mm), IMTcca (0.688±0.113 vs. 0.680±0.135 mm), or IM-GSM (82.3±17.2 vs. 86.5±15.3), while PWVao was slightly higher in patients (8.68±1.50 vs. 8.13±1.55, p<0.05). Systolic blood pressure (SBP), calcium, and PTH were higher in patients compared with controls, and decreased after PTX, while vitamin D was lower in patients and increased after PTX. While AIx, PWVao, IMTrad, and IMTcca were related to SBP, neither correlated to vitamin D levels. Only PWVao correlated weakly to plasma PTH (r = 0.29, p<0.01) and ionized calcium (r = 0.22, p<0.05) but showed no relation when age and SBP were adjusted for. Conclusion We found normal arterial function despite high calcium, PTH, and low vitamin D levels, in patients with mild PHPT without cardiovascular risk factors. The cardiovascular risk associated with low vitamin D and/or high PTH and calcium levels may be explained by their coupling to blood pressure and other risk factors rather than direct effects on arterial structure. PMID:22815708

Characterisation of Fecal Soap Fatty Acids, Calcium Contents, Bacterial Community and Short-Chain Fatty Acids in Sprague Dawley Rats Fed with Different sn-2 Palmitic Triacylglycerols Diets.

PubMed

Wan, Jianchun; Hu, Songyou; Ni, Kefeng; Chang, Guifang; Sun, Xiangjun; Yu, Liangli

2016-01-01

The structure of dietary triacylglycerols is thought to influence fatty acid and calcium absorption, as well as intestinal microbiota population of the host. In the present study, we investigated the impact of palmitic acid (PA) esterified at the sn-2 position on absorption of fatty acid and calcium and composition of intestinal microorganisms in rats fed high-fat diets containing either low sn-2 PA (12.1%), medium sn-2 PA (40.4%) or high sn-2 PA (56.3%), respectively. Fecal fatty acid profiles in the soaps were measured by gas chromatography (GC), while fecal calcium concentration was detected by ICP-MS. The fecal microbial composition was assessed using a 16S rRNA high-throughput sequencing technology and fecal short-chain fatty acids were detected by ion chromatograph. Dietary supplementation with a high sn-2 PA fat significantly reduced total fecal contents of fatty acids soap and calcium compared with the medium or low sn-2 PA fat groups. Diet supplementation with sn-2 PA fat did not change the entire profile of the gut microbiota community at phylum level and the difference at genera level also were minimal in the three treatment groups. However, high sn-2 PA fat diet could potentially improve total short-chain fatty acids content in the feces, suggesting that high dietary sn-2 PA fat might have a beneficial effect on host intestinal health.

Efficacy of a workplace osteoporosis prevention intervention: a cluster randomized trial.

PubMed

Tan, Ai May; LaMontagne, Anthony D; English, Dallas R; Howard, Peter

2016-08-24

Osteoporosis is a debilitating disease. Adequate calcium consumption and physical activity are the two major modifiable risk factors. This paper describes the major outcomes and efficacy of a workplace-based targeted behaviour change intervention to improve the dietary and physical activity behaviours of working women in sedentary occupations in Singapore. A cluster-randomized design was used, comparing the efficacy of a tailored intervention to standard care. Workplaces were the units of randomization and intervention. Sixteen workplaces were recruited from a pool of 97, and randomly assigned to intervention and control arms (eight workplaces in each). Women meeting specified inclusion criteria were then recruited to participate. Workplaces in the intervention arm received three participatory workshops and organization-wide educational activities. Workplaces in the control/standard care arm received print resources. Outcome measures were calcium intake (milligrams/day) and physical activity level (duration: minutes/week), measured at baseline, 4 weeks and 6 months post intervention. Adjusted cluster-level analyses were conducted comparing changes in intervention versus control groups, following intention-to-treat principles and CONSORT guidelines. Workplaces in the intervention group reported a significantly greater increase in calcium intake and duration of load-bearing moderate to vigorous physical activity (MVPA) compared with the standard care control group. Four weeks after intervention, the difference in adjusted mean calcium intake was 343.2 mg/day (95 % CI = 337.4 to 349.0, p < .0005) and the difference in adjusted mean load-bearing MVPA was 55.6 min/week (95 % CI = 54.5 to 56.6, p < .0005). Six months post intervention, the mean differences attenuated slightly to 290.5 mg/day (95 % CI = 285.3 to 295.7, p < .0005) and 50.9 min/week (95 % CI =49.3 to 52.6, p < .0005) respectively. This workplace-based intervention substantially improved calcium intake and load-bearing moderate to vigorous physical activity 6 months after the intervention began. Australia New Zealand Clinical Trial Registry ACTRN12616000079448 . Registered 25 January 2016 (retrospectively registered).

Molecular Dynamics Simulations of Membrane-Bound STIM1 to Investigate Conformational Changes during STIM1 Activation upon Calcium Release.

PubMed

Mukherjee, Sreya; Karolak, Aleksandra; Debant, Marjolaine; Buscaglia, Paul; Renaudineau, Yves; Mignen, Olivier; Guida, Wayne C; Brooks, Wesley H

2017-02-27

Calcium is involved in important intracellular processes, such as intracellular signaling from cell membrane receptors to the nucleus. Typically, calcium levels are kept at less than 100 nM in the nucleus and cytosol, but some calcium is stored in the endoplasmic reticulum (ER) lumen for rapid release to activate intracellular calcium-dependent functions. Stromal interacting molecule 1 (STIM1) plays a critical role in early sensing of changes in the ER's calcium level, especially when there is a sudden release of stored calcium from the ER. Inactive STIM1, which has a bound calcium ion, is activated upon ion release. Following activation of STIM1, there is STIM1-assisted initiation of extracellular calcium entry through channels in the cell membrane. This extracellular calcium entering the cell then amplifies intracellular calcium-dependent actions. At the end of the process, ER levels of stored calcium are reestablished. The main focus of this work was to study the conformational changes accompanying homo- or heterodimerization of STIM1. For this purpose, the ER luminal portion of STIM1 (residues 58-236), which includes the sterile alpha motif (SAM) domain plus the calcium-binding EF-hand domains 1 and 2 attached to the STIM1 transmembrane region (TM), was modeled and embedded in a virtual membrane. Next, molecular dynamics simulations were performed to study the conformational changes that take place during STIM1 activation and subsequent protein-protein interactions. Indeed, the simulations revealed exposure of residues in the EF-hand domains, which may be important for dimerization steps. Altogether, understanding conformational changes in STIM1 can help in drug discovery when targeting this key protein in intracellular calcium functions.

Increased calcium absorption from synthetic stable amorphous calcium carbonate: Double-blind randomized crossover clinical trial in post-menopausal women

USDA-ARS?s Scientific Manuscript database

Calcium supplementation is a widely recognized strategy for achieving adequate calcium intake. We designed this blinded, randomized, crossover interventional trial to compare the bioavailability of a new stable synthetic amorphous calcium carbonate (ACC) with that of crystalline calcium carbonate (C...

Estimation of salivary sodium, potassium, calcium, phosphorus and urea in type II diabetic patients.

PubMed

Shirzaiy, Masoumeh; Heidari, Fatemeh; Dalirsani, Zohreh; Dehghan, Javid

2015-01-01

Diabetes mellitus is an endocrine disease due to insufficiency production of insulin that is associated with altered quantity and quality in salivary secretion. Alteration in saliva can reflect the changes in patients' blood. The collection of saliva is easy therefore; the assessment of saliva is suitable for screening tests of large population. The study aimed at evaluate some elements in diabetic patients' saliva. A total of 25 diabetic patients and age-sex matched control group enrolled into the study. Absorbance spectrophotometer technique was used for assessment of some salivary elements. The assessment of saliva showed that diabetics had unstimulated salivary flow rate of 0.18 ± 0.14 mL/min compared to 0.30 ± 0.12 mL/min for healthy individuals (P<0.01). Secretion of potassium and urea to saliva was significantly higher in diabetics compared to healthy group (P<0.05). In contrast calcium, sodium and phosphorus concentration was not significantly different in two groups. The level of salivary urea, potassium and phosphorus was significantly elevated in diabetic males compared to healthy males and the level of salivary calcium in diabetic females was significantly reduced compared to healthy females (P<0.05). There was not any significant difference in salivary sodium of healthy and diabetic persons according to gender (P>0.05). The finding showed that there were some alterations in salivary elements in diabetic patients even in well-controlled subjects compared to healthy group. Moreover, some salivary elements concentrations were various in diabetic and healthy subjects regarding to the sex. Assessment of salivary composition could be beneficial in oral health evaluation. Copyright © 2013 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Structure and function of ameloblastin as an extracellular matrix protein: adhesion, calcium binding, and CD63 interaction in human and mouse.

PubMed

Zhang, Xu; Diekwisch, Thomas G H; Luan, Xianghong

2011-12-01

The functional significance of extracellular matrix proteins in the life of vertebrates is underscored by a high level of sequence variability in tandem with a substantial degree of conservation in terms of cell-cell and cell-matrix adhesion interactions. Many extracellular matrix proteins feature multiple adhesion domains for successful attachment to substrates, such as integrin, CD63, and heparin. Here we have used homology and ab initio modeling algorithms to compare mouse ameloblastin (mAMBN) and human ameloblastin (hABMN) isoforms and to analyze their potential for cell adhesion and interaction with other matrix molecules as well as calcium binding. Sequence comparison between mAMBN and hAMBN revealed a 26-amino-acid deletion in mAMBN, corresponding to a helix-loop-helix frameshift. The human AMBN domain (174Q-201G), homologous to the mAMBN 157E-178I helix-loop-helix region, formed a helix-loop motif with an extended loop, suggesting a higher degree of flexibility of hAMBN compared with mAMBN, as confirmed by molecular dynamics simulation. Heparin-binding domains, CD63-interaction domains, and calcium-binding sites in both hAMBN and mAMBN support the concept of AMBN as an extracellular matrix protein. The high level of conservation between AMBN functional domains related to adhesion and differentiation was remarkable when compared with only 61% amino acid sequence homology. © 2011 Eur J Oral Sci.

Chronic alcohol feeding potentiates hormone‐induced calcium signalling in hepatocytes

PubMed Central

Bartlett, Paula J.; Antony, Anil Noronha; Agarwal, Amit; Hilly, Mauricette; Prince, Victoria L.; Combettes, Laurent; Hoek, Jan B.

2017-01-01

Key points Chronic alcohol consumption causes a spectrum of liver diseases, but the pathogenic mechanisms driving the onset and progression of disease are not clearly defined.We show that chronic alcohol feeding sensitizes rat hepatocytes to Ca2+‐mobilizing hormones resulting in a leftward shift in the concentration–response relationship and the transition from oscillatory to more sustained and prolonged Ca2+ increases.Our data demonstrate that alcohol‐dependent adaptation in the Ca2+ signalling pathway occurs at the level of hormone‐induced inositol 1,4,5 trisphosphate (IP3) production and does not involve changes in the sensitivity of the IP3 receptor or size of internal Ca2+ stores.We suggest that prolonged and aberrant hormone‐evoked Ca2+ increases may stimulate the production of mitochondrial reactive oxygen species and contribute to alcohol‐induced hepatocyte injury. Abstract ‘Adaptive’ responses of the liver to chronic alcohol consumption may underlie the development of cell and tissue injury. Alcohol administration can perturb multiple signalling pathways including phosphoinositide‐dependent cytosolic calcium ([Ca2+]i) increases, which can adversely affect mitochondrial Ca2+ levels, reactive oxygen species production and energy metabolism. Our data indicate that chronic alcohol feeding induces a leftward shift in the dose–response for Ca2+‐mobilizing hormones resulting in more sustained and prolonged [Ca2+]i increases in both cultured hepatocytes and hepatocytes within the intact perfused liver. Ca2+ increases were initiated at lower hormone concentrations, and intercellular calcium wave propagation rates were faster in alcoholics compared to controls. Acute alcohol treatment (25 mm) completely inhibited hormone‐induced calcium increases in control livers, but not after chronic alcohol‐feeding, suggesting desensitization to the inhibitory actions of ethanol. Hormone‐induced inositol 1,4,5 trisphosphate (IP3) accumulation and phospholipase C (PLC) activity were significantly potentiated in hepatocytes from alcohol‐fed rats compared to controls. Removal of extracellular calcium, or chelation of intracellular calcium did not normalize the differences in hormone‐stimulated PLC activity, indicating calcium‐dependent PLCs are not upregulated by alcohol. We propose that the liver ‘adapts’ to chronic alcohol exposure by increasing hormone‐dependent IP3 formation, leading to aberrant calcium increases, which may contribute to hepatocyte injury. PMID:28220501

Concentrations of cadmium and selected essential elements in malignant large intestine tissue

PubMed Central

Dziki, Adam; Kilanowicz, Anna; Sapota, Andrzej; Duda-Szymańska, Joanna; Daragó, Adam

2015-01-01

Introduction Colorectal cancer is one of the most common cancers worldwide. Incidence rates of large intestine cancer indicate a role of environmental and occupational factors. The role of essential elements and their interaction with toxic metals can contribute to the explanation of a complex mechanism by which large intestine cancer develops. Bearing this in mind, determining the levels of essential and toxic elements in tissues (organs), as well as in body fluids, seems to shed light on their role in the mode of action in malignant disease. Aim Determination of the levels of cadmium, zinc, copper, selenium, calcium, magnesium, and iron in large intestine malignant tissue. Material and methods Two intraoperative intestine sections were investigated: one from the malignant tissue and the other one from the normal tissue, collected from each person with diagnosed large intestine cancer. Cadmium, zinc, copper, calcium, magnesium, and iron levels were determined with atomic absorption spectrometry, and selenium levels by spectrofluorimetric method. Results The levels of copper, selenium, and magnesium were higher in the malignant than in normal tissues. In addition, the zinc/copper and calcium/magnesium relationship was altered in malignant tissue, where correlations were lower compared to non-malignant tissue. Conclusions The results seems to demonstrate disturbed homeostasis of some essential elements. However, it is hard to confirm their involvement in the aetiology of colorectal cancer. PMID:27110307

Nutrition knowledge, outcome expectations, self-efficacy, and eating behaviors by calcium intake level in Korean female college students.

PubMed

Kim, Min Ju; Kim, Kyung Won

2015-10-01

Calcium is important but deficient in diets of young adult women. This study aimed to examine if cognitive factors and eating behaviors differ according to calcium intake based on the Social Cognitive Theory. Subjects were female college students in Seoul, Korea. Three hundred students completed the questionnaire regarding calcium intake, nutrition knowledge, outcome expectations, self-efficacy and eating behaviors. Data on 240 students were analyzed using t-test or χ(2)-test. Subjects were categorized into two groups, high calcium intake (HC, ≥ 650 mg/day) and low calcium intake (LC, < 650 mg/day), according to recommended intakes of calcium for women aged 19-29 years. The LC group constituted 77.9% of total subjects. Nutrition knowledge was not different according to calcium intake. Three out of 12 outcome expectations items were significantly different between the HC and LC groups. Subjects in the HC group agreed more strongly with the practical benefits of consuming calcium-rich foods, including 'taste' (P < 0.01) and 'going well with other snacks' (P < 0.05), compared to those in the LC group. Negative expectations of 'indigestion' were stronger in the LC group than HC group (P < 0.001). Among self-efficacy items, perceived ability of 'eating dairy foods for snacks' (P < 0.001), 'eating dairy foods every day' (P < 0.01), and 'eating calcium-rich side dishes at meals' (P < 0.05) differed significantly between the HC and LC groups. Eating behaviors including more frequent consumption of dairy foods, fruits or fruit juice (P < 0.001), anchovy, seaweeds, green vegetables, protein-rich foods (P < 0.05), and less frequent consumption of sweets or soft drinks (P < 0.01) were significantly related to calcium intake. This study found that outcome expectations, self-efficacy in consuming calcium-rich foods, and eating behaviors are important in explaining calcium intake. Nutrition education needs to address practical benefits, reduce negative expectations of calcium-rich foods, increase self-efficacy, and modify eating behaviors contributing to calcium intake.

Genome-wide analysis of wheat calcium ATPases and potential role of selected ACAs and ECAs in calcium stress.

PubMed

Aslam, Roohi; Williams, Lorraine E; Bhatti, Muhammad Faraz; Virk, Nasar

2017-10-27

P 2 - type calcium ATPases (ACAs-auto inhibited calcium ATPases and ECAs-endoplasmic reticulum calcium ATPases) belong to the P- type ATPase family of active membrane transporters and are significantly involved in maintaining accurate levels of Ca 2+ , Mn 2+ and Zn 2+ in the cytosol as well as playing a very important role in stress signaling, stomatal opening and closing and pollen tube growth. Here we report the identification and possible role of some of these ATPases from wheat. In this study, ACA and ECA sequences of six species (belonging to Poaceae) were retrieved from different databases and a phylogenetic tree was constructed. A high degree of evolutionary relatedness was observed among P 2 sequences characterized in this study. Members of the respective groups from different plant species were observed to fall under the same clade. This pattern highlights the common ancestry of P 2- type calcium ATPases. Furthermore, qRT-PCR was used to analyse the expression of selected ACAs and ECAs from Triticum aestivum (wheat) under calcium toxicity and calcium deficiency. The data indicated that expression of ECAs is enhanced under calcium stress, suggesting possible roles of these ATPases in calcium homeostasis in wheat. Similarly, the expression of ACAs was significantly different in plants grown under calcium stress as compared to plants grown under control conditions. This gives clues to the role of ACAs in signal transduction during calcium stress in wheat. Here we concluded that wheat genome consists of nine P 2B and three P 2A -type calcium ATPases. Moreover, gene loss events in wheat ancestors lead to the loss of a particular homoeolog of a gene in wheat. To elaborate the role of these wheat ATPases, qRT-PCR was performed. The results indicated that when plants are exposed to calcium stress, both P 2A and P 2B gene expression get enhanced. This further gives clues about the possible role of these ATPases in wheat in calcium management. These findings can be useful in future for genetic manipulations as well as in wheat genome annotation process.

Defective Store-Operated Calcium Entry Causes Partial Nephrogenic Diabetes Insipidus

PubMed Central

Mamenko, Mykola; Dhande, Isha; Tomilin, Viktor; Zaika, Oleg; Boukelmoune, Nabila; Zhu, Yaming; Gonzalez-Garay, Manuel L.

2016-01-01

Store-operated calcium entry (SOCE) is the mechanism by which extracellular signals elicit prolonged intracellular calcium elevation to drive changes in fundamental cellular processes. Here, we investigated the role of SOCE in the regulation of renal water reabsorption, using the inbred rat strain SHR-A3 as an animal model with disrupted SOCE. We found that SHR-A3, but not SHR-B2, have a novel truncating mutation in the gene encoding stromal interaction molecule 1 (STIM1), the endoplasmic reticulum calcium (Ca2+) sensor that triggers SOCE. Balance studies revealed increased urine volume, hypertonic plasma, polydipsia, and impaired urinary concentrating ability accompanied by elevated circulating arginine vasopressin (AVP) levels in SHR-A3 compared with SHR-B2. Isolated, split-open collecting ducts (CD) from SHR-A3 displayed decreased basal intracellular Ca2+ levels and a major defect in SOCE. Consequently, AVP failed to induce the sustained intracellular Ca2+ mobilization that requires SOCE in CD cells from SHR-A3. This effect decreased the abundance of aquaporin 2 and enhanced its intracellular retention, suggesting impaired sensitivity of the CD to AVP in SHR-A3. Stim1 knockdown in cultured mpkCCDc14 cells reduced SOCE and basal intracellular Ca2+ levels and prevented AVP-induced translocation of aquaporin 2, further suggesting the effects in SHR-A3 result from the expression of truncated STIM1. Overall, these results identify a novel mechanism of nephrogenic diabetes insipidus and uncover a role of SOCE in renal water handling. PMID:26574044

Computation of Calcium Score with Dual Energy CT: A Phantom Study

PubMed Central

Kumar, Vidhya; Min, James K.; He, Xin; Raman, Subha V.

2016-01-01

Dual energy computed tomography (DECT) improves material and tissue characterization compared to single energy CT (SECT); we sought to validate coronary calcium quantification in advancing cardiovascular DECT. In an anthropomorphic phantom, agreement between measurements was excellent, and Bland-Altman analysis demonstrated minimal bias. Compared to the known calcium mass for each phantom, calcium mass by DECT was highly accurate. Noncontrast DECT yields accurate calcium measures, and warrants consideration in cardiac protocols for additional tissue characterizations. PMID:27680414

Association between direct measurement of active serum calcium and risk of type 2 diabetes mellitus: A prospective study.

PubMed

Zaccardi, F; Webb, D R; Carter, P; Pitocco, D; Khunti, K; Davies, M J; Kurl, S; Laukkanen, J A

2015-06-01

Previous prospective studies showing a positive association between serum calcium and incidence of type 2 diabetes mellitus (T2DM) have relied on total calcium or an indirect estimate of active, ionized calcium (iCa). We aimed to assess this relationship using a direct measurement of iCa. iCa and cardiometabolic risk factors were measured in a population-based sample of 2350 men without a known history of T2DM at baseline. Associations between iCa levels and incident cases of T2DM (self-reported, ascertained with a glucose tolerance test, or determined by record linkage to national registers) were estimated using Cox regression analyses adjusted for potential confounders. At baseline, mean (standard deviation) age was 53 (5) years and mean iCa 1.18 (0.05) mmol/L. During a median follow-up of 23.1 years, 140 new cases of T2DM were recorded. In a multivariable analysis adjusted for age, body mass index, systolic blood pressure, serum HDL-cholesterol, and family history of T2DM, there was no association comparing second (hazard ratio 0.84; 95% confidence interval 0.59-1.18), third (0.77; 0.52-1.14), or fourth (0.98; 0.69-1.39) vs first quartile of iCa (p for trend 0.538); further adjustment for C-reactive protein, physical activity level, and triglycerides did not change the estimates (p for trend 0.389). In this study, we did not find evidence of an association between direct measurement of active calcium and risk of T2DM. Further studies are needed to confirm our findings and define the relationship between factors influencing indirect calcium estimation and incident T2DM. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of low calcium dialysate on the progression of coronary artery calcification in hemodialysis patients: An open-label 12-month randomized clinical trial.

PubMed

Kim, Soo Jin; Lee, Young-Ki; Oh, Jieun; Cho, AJin; Noh, Jung Woo

2017-09-15

The association between the dialysate calcium level and coronary artery calcification (CAC) has not yet been evaluated in hemodialysis patients. The objective of this study was to determine whether lowering the dialysate calcium levels would decrease the progression of coronary artery calcification (CAC) compared to using standard calcium dialysate. We conducted an open-label randomized trial with parallel groups. The patients were randomly assigned to either 12-month treatment with low calcium dialysate (LCD; 1.25mmol/L, n=36) or standard calcium dialysate (SCD; 1.5mmol/L, n=40). The primary outcome was the change in the CAC scores assessed by 64-slice multidetector computed tomography after 12months. During the treatment period, CAC scores increased in both groups, especially significant in LCD group (402.5±776.8, 580.5±1011.9, P=0.004). When we defined progressors as patients at second and third tertiles of CAC changes, progressor group had a higher proportion of LCD-treated patients than SCD-treated patients (P=0.0229). In multivariate analysis, LCD treatment is a significant risk factor for increase in CAC scores (odds ratio=5.720, 95% CI: 1.219-26.843, P=0.027). Use of LCD may accelerate the progression of CAC in patients with chronic hemodialysis over a 12-month period. Clinical Research Information Service [Internet]; Osong (Chungcheongbuk-do): Korea Centers for Disease Control and Prevention, Ministry of Health and Welfare (Republic of Korea), 2010: KCT0000942. Available from: https://cris.nih.go.kr/cris/search/search_result_st01_kren.jsp?seq=3572&sLeft=2&type=my. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

One nuclear calcium transient induced by a single burst of action potentials represents the minimum signal strength in activity-dependent transcription in hippocampal neurons.

PubMed

Yu, Yan; Oberlaender, Kristin; Bengtson, C Peter; Bading, Hilmar

2017-07-01

Neurons undergo dramatic changes in their gene expression profiles in response to synaptic stimulation. The coupling of neuronal excitation to gene transcription is well studied and is mediated by signaling pathways activated by cytoplasmic and nuclear calcium transients. Despite this, the minimum synaptic activity required to induce gene expression remains unknown. To address this, we used cultured hippocampal neurons and cellular compartment analysis of temporal activity by fluorescence in situ hybridization (catFISH) that allows detection of nascent transcripts in the cell nucleus. We found that a single burst of action potentials, consisting of 24.4±5.1 action potentials during a 6.7±1.9s depolarization of 19.5±2.0mV causing a 9.3±0.9s somatic calcium transient, is sufficient to activate transcription of the immediate early gene arc (also known as Arg3.1). The total arc mRNA yield produced after a single burst-induced nuclear calcium transient was very small and, compared to unstimulated control neurons, did not lead to a significant increase in arc mRNA levels measured using quantitative reverse transcriptase PCR (qRT-PCR) of cell lysates. Significantly increased arc mRNA levels became detectable in hippocampal neurons that had undergone 5-8 consecutive burst-induced nuclear calcium transients at 0.05-0.15Hz. These results indicate that a single burst-induced nuclear calcium transient can activate gene expression and that transcription is rapidly shut off after synaptic stimulation has ceased. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intracellular sphingosine releases calcium from lysosomes.

PubMed

Höglinger, Doris; Haberkant, Per; Aguilera-Romero, Auxiliadora; Riezman, Howard; Porter, Forbes D; Platt, Frances M; Galione, Antony; Schultz, Carsten

2015-11-27

To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in late endosomes and lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC.

Chemical analysis of World Trade Center fine particulate matter for use in toxicologic assessment.

PubMed

McGee, John K; Chen, Lung Chi; Cohen, Mitchell D; Chee, Glen R; Prophete, Colette M; Haykal-Coates, Najwa; Wasson, Shirley J; Conner, Teri L; Costa, Daniel L; Gavett, Stephen H

2003-06-01

The catastrophic destruction of the World Trade Center (WTC) on 11 September 2001 caused the release of high levels of airborne pollutants into the local environment. To assess the toxicity of fine particulate matter [particulate matter with a mass median aerodynamic diameter < 2.5 microm (PM2.5)], which may adversely affect the health of workers and residents in the area, we collected fallen dust samples on 12 and 13 September 2001 from sites within a half-mile of Ground Zero. Samples of WTC dust were sieved, aerosolized, and size-separated, and the PM2.5 fraction was isolated on filters. Here we report the chemical and physical properties of PM2.5 derived from these samples and compare them with PM2.5 fractions of three reference materials that range in toxicity from relatively inert to acutely toxic (Mt. St. Helens PM; Washington, DC, ambient air PM; and residual oil fly ash). X-ray diffraction of very coarse sieved WTC PM (< 53 microm) identified calcium sulfate (gypsum) and calcium carbonate (calcite) as major components. Scanning electron microscopy confirmed that calcium-sulfur and calcium-carbon particles were also present in the WTC PM2.5 fraction. Analysis of WTC PM2.5 using X-ray fluorescence, neutron activation analysis, and inductively coupled plasma spectrometry showed high levels of calcium (range, 22-33%) and sulfur (37-43% as sulfate) and much lower levels of transition metals and other elements. Aqueous extracts of WTC PM2.5 were basic (pH range, 8.9-10.0) and had no evidence of significant bacterial contamination. Levels of carbon were relatively low, suggesting that combustion-derived particles did not form a significant fraction of these samples recovered in the immediate aftermath of the destruction of the towers. Because gypsum and calcite are known to cause irritation of the mucus membranes of the eyes and respiratory tract, inhalation of high doses of WTC PM2.5 could potentially cause toxic respiratory effects.

The FGF-2-triggered protection of cardiac subsarcolemmal mitochondria from calcium overload is mitochondrial connexin 43-dependent.

PubMed

Srisakuldee, Wattamon; Makazan, Zhanna; Nickel, Barbara E; Zhang, Feixiong; Thliveris, James A; Pasumarthi, Kishore B S; Kardami, Elissavet

2014-07-01

Fibroblast growth factor 2 (FGF-2) protects the heart from ischaemia- and reperfusion-induced cell death by a mechanism linked to protein kinase C (PKC)ε-mediated connexin 43 (Cx43) phosphorylation. Cx43 localizes predominantly to gap junctions, but has also been detected at subsarcolemmal (SSM), but not interfibrillar (IFM), mitochondria, where it is considered important for cardioprotection. We have now examined the effect of FGF-2 administration to the heart on resistance to calcium-induced permeability transition (mPTP) of isolated SSM vs. IFM suspensions, in relation to mitochondrial PKCε/Cx43 levels, phosphorylation, and the presence of peptide Gap27, a Cx43 channel blocker. FGF-2 perfusion increased resistance to calcium-induced mPTP in SSM and IFM suspensions by 2.9- and 1.7-fold, respectively, compared with their counterparts from vehicle-perfused hearts, assessed spectrophotometrically as cyclosporine A-inhibitable swelling. The salutary effect of FGF-2 was lost in SSM, but not in IFM, in the presence of Gap27. FGF-2 perfusion increased relative levels of PKCε, phospho(p) PKCε, and Tom-20 translocase in SSM and IFM, and of Cx43 in SSM. Phospho-serine (pS) 262- and pS368-Cx43 showed a 30- and 8-fold increase, respectively, in SSM from FGF-2-treated, compared with untreated, hearts. Stimulation of control SSM with phorbol 12-myristate 13-acetate (PMA), a PKC activator, increased both calcium tolerance and mitochondrial Cx43 phosphorylation at S262 and S368. The PMA-induced phosphorylation of mitochondrial Cx43 was prevented by εV1-2, a PKCε-inhibiting peptide. SSM are more responsive than IFM to FGF-2-triggered protection from calcium-induced mPTP, by a mitochondrial Cx43 channel-mediated pathway, associated with mitochondrial Cx43 phosphorylation at PKCε target sites. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Dietary calcium and cholecalciferol modulate cyclin D1 expression, apoptosis, and tumorigenesis in intestine of adenomatous polyposis coli1638N/+ mice.

PubMed

Yang, Kan; Lamprecht, Sergio A; Shinozaki, Hiroharu; Fan, Kunhua; Yang, Wancai; Newmark, Harold L; Kopelovich, Levy; Edelmann, Winfried; Jin, Bo; Gravaghi, Claudia; Augenlicht, Leonard; Kucherlapati, Raju; Lipkin, Martin

2008-09-01

Both epidemiological and experimental findings have indicated that components of Western diets influence colonic tumorigenesis. Among dietary constituents, calcium and cholecalciferol have emerged as promising chemopreventive agents. We have demonstrated that a Western-style diet (WD) with low levels of calcium and cholecalciferol and high levels of (n-6) PUFA, increased the incidence of neoplasia in mouse intestine compared with a standard AIN-76A diet; models included wild-type mice and mice with targeted mutations. In the present study, adenomatous polyposis coli (Apc)(1638N/+) mice carrying a heterozygous Apc mutation were fed either an AIN-76A diet, a WD, or a WD supplemented with calcium and cholecalciferol (WD/Ca/VitD3). Diets were fed for 24 wk and effects on cellular and molecular events were assessed by performing immunohistochemistry in colonic epithelium along the crypt-to-surface continuum. Feeding WD to Apc(1638N/+) mice not only enhanced cyclin D1 expression in colonic epithelium compared with AIN-76A treatment as previously reported but also significantly increased the expression of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) concomitantly with a decrease in the proapoptotic Bcl2-associated X protein and the number of apoptotic epithelial cells. WD treatment enhanced mutant Apc-driven small intestinal carcinogenesis and also resulted in the formation of a small number of colonic adenomas (0.16 +/- 0.09; P < 0.05). By contrast, the WD/Ca/VitD3 diet reversed WD-induced growth, promoting changes in colonic epithelium. Importantly, Apc(1638N/+) mice fed the WD/Ca/VitD3 diet did not develop colonic tumors, further indicating that dietary calcium and cholecalciferol have a key role in the chemoprevention of colorectal neoplasia in this mouse model of human colon cancer.

In vitro degradation and cell response of calcium carbonate composite ceramic in comparison with other synthetic bone substitute materials.

PubMed

He, Fupo; Zhang, Jing; Yang, Fanwen; Zhu, Jixiang; Tian, Xiumei; Chen, Xiaoming

2015-05-01

The robust calcium carbonate composite ceramics (CC/PG) can be acquired by fast sintering calcium carbonate at a low temperature (650 °C) using a biocompatible, degradable phosphate-based glass (PG) as sintering agent. In the present study, the in vitro degradation and cell response of CC/PG were assessed and compared with 4 synthetic bone substitute materials, calcium carbonate ceramic (CC), PG, hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ceramics. The degradation rates in decreasing order were as follows: PG, CC, CC/PG, β-TCP, and HA. The proliferation of rat bone mesenchymal stem cells (rMSCs) cultured on the CC/PG was comparable with that on CC and PG, but inferior to HA and β-TCP. The alkaline phosphatase (ALP) activity of rMSCs on CC/PG was lower than PG, comparable with β-TCP, but higher than HA. The rMSCs on CC/PG and PG had enhanced gene expression in specific osteogenic markers, respectively. Compared to HA and β-TCP, the rMSCs on the CC/PG expressed relatively lower level of collagen I and runt-related transcription factor 2, but showed more considerable expression of osteopontin. Although CC, PG, HA, and β-TCP possessed impressive performances in some specific aspects, they faced extant intrinsic drawbacks in either degradation rate or mechanical strength. Based on considerable compressive strength, moderate degradation rate, good cell response, and being free of obvious shortcoming, the CC/PG is promising as another choice for bone substitute materials. Copyright © 2015 Elsevier B.V. All rights reserved.

[Comparative characteristics of lead and cadmium intoxication in the Khanty-Mansi autonomous district].

PubMed

Korchina, T Ia; Korchin, V I

2011-01-01

The Khanty-Mansi Autonomous District (KMAD) occupies a prominent place in the economy of Russia in oil and gas production and energy generation. The development of hydrocarbon raw material extraction in the district does great damage to the environment and nature. This results in the accumulation of toxic chemical elements in man. The levels of lead, cadmium, calcium, and zinc were measured in the hair of indigenous and non-indigenous populations of the district. High lead and cadmium and low calcium and zinc concentration were found in indigenous adults and children in the KMAD.

Ultimobranchial body and parathyroid gland of the parrot Psittacula psittacula in response to experimental hypercalcemia.

PubMed

Swarup, K; Tewari, N P; Srivastav, A K

Psittacula psittacula when subjected to long term hypercalcemia by intramuscular injections of vitamin D2 (20,000 I.U.) on alternate days and by increasing dietary calcium, exhibit a rise in the serum calcium level after 10, 20 and 30 days of treatment as compared to their corresponding controls. The ultimobranchial cells show progressive hypertrophy up to 20th day of the treatment. From 20th day till the end of the experiment (30 days) these cells show feeble staining response. The parathyroid glands suffer from degenerative changes due to its inactivity under chronic hypercalcemia.

The complex nature of calcium cation interactions with phospholipid bilayers

PubMed Central

Melcrová, Adéla; Pokorna, Sarka; Pullanchery, Saranya; Kohagen, Miriam; Jurkiewicz, Piotr; Hof, Martin; Jungwirth, Pavel; Cremer, Paul S.; Cwiklik, Lukasz

2016-01-01

Understanding interactions of calcium with lipid membranes at the molecular level is of great importance in light of their involvement in calcium signaling, association of proteins with cellular membranes, and membrane fusion. We quantify these interactions in detail by employing a combination of spectroscopic methods with atomistic molecular dynamics simulations. Namely, time-resolved fluorescent spectroscopy of lipid vesicles and vibrational sum frequency spectroscopy of lipid monolayers are used to characterize local binding sites of calcium in zwitterionic and anionic model lipid assemblies, while dynamic light scattering and zeta potential measurements are employed for macroscopic characterization of lipid vesicles in calcium-containing environments. To gain additional atomic-level information, the experiments are complemented by molecular simulations that utilize an accurate force field for calcium ions with scaled charges effectively accounting for electronic polarization effects. We demonstrate that lipid membranes have substantial calcium-binding capacity, with several types of binding sites present. Significantly, the binding mode depends on calcium concentration with important implications for calcium buffering, synaptic plasticity, and protein-membrane association. PMID:27905555

The complex nature of calcium cation interactions with phospholipid bilayers

NASA Astrophysics Data System (ADS)

Melcrová, Adéla; Pokorna, Sarka; Pullanchery, Saranya; Kohagen, Miriam; Jurkiewicz, Piotr; Hof, Martin; Jungwirth, Pavel; Cremer, Paul S.; Cwiklik, Lukasz

2016-12-01

Understanding interactions of calcium with lipid membranes at the molecular level is of great importance in light of their involvement in calcium signaling, association of proteins with cellular membranes, and membrane fusion. We quantify these interactions in detail by employing a combination of spectroscopic methods with atomistic molecular dynamics simulations. Namely, time-resolved fluorescent spectroscopy of lipid vesicles and vibrational sum frequency spectroscopy of lipid monolayers are used to characterize local binding sites of calcium in zwitterionic and anionic model lipid assemblies, while dynamic light scattering and zeta potential measurements are employed for macroscopic characterization of lipid vesicles in calcium-containing environments. To gain additional atomic-level information, the experiments are complemented by molecular simulations that utilize an accurate force field for calcium ions with scaled charges effectively accounting for electronic polarization effects. We demonstrate that lipid membranes have substantial calcium-binding capacity, with several types of binding sites present. Significantly, the binding mode depends on calcium concentration with important implications for calcium buffering, synaptic plasticity, and protein-membrane association.

A comparative in vitro study investigating the occlusion and mineralization properties of commercial toothpastes in a four-day dentin disc model.

PubMed

Parkinson, Charles R; Willson, Richard J

2011-01-01

The objective of this study was to evaluate the relative level of dentin tubule occlusion and dentin mineralization conferred by a 5% w/w calcium sodium phosphosilicate (45S5)/1450 ppm fluoride toothpaste in comparison to a range of commercial toothpastes reported to occlude dentin tubules. Two separate experiments were employed to (i) determine the level of dentin tubule occlusion, and (ii) explore the change in dentin mineralization conferred by a number of marketed toothpastes and controls, following twice-daily brushing in a longitudinal, acid challenge-based, dentin disc model. In Study I, 192 bovine dentin discs, polished and etched in citric acid to provide a smooth dentin surface with patent tubules, were divided into eight treatment groups and subjected to brushing with one of seven test toothpastes or deionized water over four days. Prior to and between treatments, the dentin samples were stored in saliva. The test products were fluoridated toothpastes containing: calcium sodium phosphosilicate (45S5); strontium acetate; arginine/calcium carbonate; amine fluoride; calcium sulphate/diphosphate; stannous fluoride; casein stabilized amorphous calcium phosphate toothpaste; and a non-occluding negative control, deionized water. At the end of each treatment day (1 though 4), one group of samples was removed for scanning electron microscopy (SEM) analysis and graded on a categorical visual scale to assess the level of dentin tubule occlusion. A subset of samples from Study I was also cross-sectioned and examined using SEM. For the exploratory mineralization study (Study II), 120 dentin specimens were prepared as previously described and divided into four treatment groups consisting of A, C, F, and a tooth sealant varnish (I), and subjected to the treatment regimen described in Study I. The dentin samples were assessed for changes in surface microhardness using an indenter fitted with a Knoop probe and the level of dentin occlusion. In Study I, the 5% w/w calcium sodium phosphosilicate/1450 ppm fluoride-containing toothpaste (A), the stannous fluoride-containing toothpaste (F), and the strontium acetate-containing toothpaste (B) delivered the highest level of occlusion following four days of twice-daily brushing and a twice-daily acid challenge on days 3 and 4. Surface analysis of a subset of Study I samples, following four days of treatment, indicated that the 5% w/w calcium sodium phosphosilicate/1450 ppm fluoride-containing toothpaste formed a distinct layer at the surface of dentin. For Study II, surface microhardness analysis revealed that the 5% w/w calcium sodium phosphosilicate/1450 ppm fluoride-containing toothpaste (A) delivered significantly more surface hardening then the control or competitor toothpastes on days 2 and 4. Desensitizing toothpastes reported to operate by an occlusion mechanism have been observed to confer varying degrees of dentin tubule occlusion and dentin mineralization over four days in an acid challenge-based in vitro model. A 5% w/w calcium sodium phosphosilicate/1450 ppm fluoride-containing toothpaste was observed to impart a significant level of dentin tubule occlusion and surface hardening, and form durable occlusive deposits following four days of twice-daily brushing in vitro.

Mechanisms of Intracellular Calcium Homeostasis in MC3T3-E1 Cells and Bone Tissues of Sprague-Dawley Rats Exposed to Fluoride.

PubMed

Duan, Xiao-qin; Li, Yan-hui; Zhang, Xiu-yun; Zhao, Zhi-tao; Wang, Ying; Wang, Huan; Li, Guang-sheng; Jing, Ling

2016-04-01

Calcium homeostasis of osteoblasts (OBs) has an important role in the physiology and pathology of bone tissue. In order to study the mechanisms of intracellular calcium homeostasis, MC3T3-E1 cells and Sprague-Dawley rats were treated with different concentrations of fluoride. Then, we examined intracellular-free calcium ion ([Ca(2+)]i) in MC3T3-E1 cells as well as mRNA and protein levels of Cav1.2, the main subunit of L-type voltage-dependent calcium channels (VDCCs), Na(+)/Ca(2+) exchange carriers (NCS), and plasma membrane Ca(2+)-ATPase (PMCA), inositol 1,4,5-trisphosphate receptor (IP3R) channels, sarco/endoplasmic reticulum calcium ATPase 2b (SERCA2b)/ATP2A2 in vitro, and rat bone tissues in vivo. Our results showed that [Ca(2+)]i of fluoride-treated OBs increased in a concentration-dependent manner with an increase in the concentration of fluoride. We also found that the low dose of fluoride led to high expression levels of Cav1.2, NCS-1, and PMCA and low expression levels of IP3R and SERCA2b/ATP2A2, while the high dose of fluoride induced an increase in SERCA2b/ATP2A2 levels and decrease in Cav1.2, PMCA, NCS-1, and IP3R levels. These results demonstrate that calcium channels and calcium pumps of plasma and endoplasmic reticulum (ER) membranes keep intracellular calcium homeostasis by regulating Cav1.2, NCS-1, PMCA, IP3R, and SERCA2b/ATP2A2 expression.

Physicochemical studies on Uburu Salt Lake Ebonyi State-Nigeria.

PubMed

Akubugwo, I E; Ofoegbu, C J; Ukwuoma, C U

2007-09-15

Physicochemical properties of soil (sediment) and water from Uburu salt lake were evaluated and compared with control soil and surface water from the same community. Results showed significant (p < 0.05) higher values for the heavy metals cadmium, chromium, copper, lead and zinc in the lake water relative to the control. The values of these metals in the lake soil (sediments) however, were significantly (p < 0.05) lower than the control soil. Similar significant (p < 0.05) elevations were observed in the lake water temperature, salinity, pH, calcium, magnesium, sodium, potassium, nitrate, carbonate, sulphate and phosphate levels compared to the control. Significant (p < 0.05) changes were also noted in the lake soil's pH, exchangeable acidity, nitrogen, organic carbon, calcium and magnesium levels. Also the soil texture was affected relative to the control. In a number of cases, the values of the studied parameters were higher than the permissible WHO standards. In view of these findings, cautious use of the salt lake soil and water is advocated.

Interactions between calcium and phosphorus in the regulation of the production of fibroblast growth factor 23 in vivo

PubMed Central

Quinn, Stephen J.; Thomsen, Alex R. B.; Pang, Jian L.; Kantham, Lakshmi; Bräuner-Osborne, Hans; Pollak, Martin; Goltzman, David

2013-01-01

Calcium and phosphorus homeostasis are highly interrelated and share common regulatory hormones, including FGF23. However, little is known about calcium's role in the regulation of FGF23. We sought to investigate the regulatory roles of calcium and phosphorus in FGF23 production using genetic mouse models with targeted inactivation of PTH (PTH KO) or both PTH and the calcium-sensing receptor (CaSR; PTH-CaSR DKO). In wild-type, PTH KO, and PTH-CaSR DKO mice, elevation of either serum calcium or phosphorus by intraperitoneal injection increased serum FGF23 levels. In PTH KO and PTH-CaSR DKO mice, however, increases in serum phosphorus by dietary manipulation were accompanied by severe hypocalcemia, which appeared to blunt stimulation of FGF23 release. Increases in dietary phosphorus in PTH-CaSR DKO mice markedly decreased serum 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] despite no change in FGF23, suggesting direct regulation of 1,25(OH)2D3 synthesis by serum phosphorus. Calcium-mediated increases in serum FGF23 required a threshold level of serum phosphorus of about 5 mg/dl. Analogously, phosphorus-elicited increases in FGF23 were markedly blunted if serum calcium was less than 8 mg/dl. The best correlation between calcium and phosphorus and serum FGF23 was found between FGF23 and the calcium × phosphorus product. Since calcium stimulated FGF23 production in the PTH-CaSR DKO mice, this effect cannot be mediated by the full-length CaSR. Thus the regulation of FGF23 by both calcium and phosphorus appears to be fundamentally important in coordinating the serum levels of both mineral ions and ensuring that the calcium × phosphorus product remains within a physiological range. PMID:23233539

Monitoring Calcium in Trout Eggs Exposed to Hydrazine.

DTIC Science & Technology

1981-07-10

differentiation processes (Chapman, 1980). The high level of calcium in the notochord can be attributed to poor circulation which is characteristic of this...healthy muscle of the same individual. The notochord of the 8.0 mg/P group showed a higher calcium level than the control group. The chorion did not...calcium can alter the process . The above would suggest that even if some hydrazine is converted to N2 and thereby produce the gas bubble disease

Supplemental levels of iron and calcium interfere with repletion of zinc status in zinc-deficient animals.

PubMed

Jayalakshmi, S; Platel, Kalpana

2016-05-18

Negative interactions between minerals interfering with each other's absorption are of concern when iron and calcium supplements are given to pregnant women and children. We have previously reported that supplemental levels of iron and calcium inhibit the bioaccessibility of zinc, and compromise zinc status in rats fed diets with high levels of these two minerals. The present study examined the effect of supplemental levels of iron and calcium on the recovery of zinc status during a zinc repletion period in rats rendered zinc-deficient. Iron and calcium, both individually and in combination, significantly interfered with the recovery of zinc status in zinc deficient rats during repletion with normal levels of zinc in the diet. Rats maintained on diets containing supplemental levels of these two minerals had significantly lower body weight, and the concentration of zinc in serum and organs was significantly lower than in zinc-deficient rats not receiving the supplements. Iron and calcium supplementation also significantly inhibited the activity of zinc-containing enzymes in the serum as well as liver. Both iron and calcium independently exerted this negative effect on zinc status, while their combination seemed to have a more prominent effect, especially on the activities of zinc containing enzymes. This investigation is probably the first systematic study on the effect of these two minerals on the zinc status of zinc deficient animals and their recovery during repletion with normal amounts of zinc.

Calcium dependent current recordings in Xenopus laevis oocytes in microgravity

NASA Astrophysics Data System (ADS)

Wuest, Simon L.; Roesch, Christian; Ille, Fabian; Egli, Marcel

2017-12-01

Mechanical unloading by microgravity (or weightlessness) conditions triggers profound adaptation processes at the cellular and organ levels. Among other mechanisms, mechanosensitive ion channels are thought to play a key role in allowing cells to transduce mechanical forces. Previous experiments performed under microgravity have shown that gravity affects the gating properties of ion channels. Here, a method is described to record a calcium-dependent current in native Xenopus laevis oocytes under microgravity conditions during a parabolic flight. A 3-voltage-step protocol was applied to provoke a calcium-dependent current. This current increased with extracellular calcium concentration and could be reduced by applying extracellular gadolinium. The custom-made ;OoClamp; hardware was validated by comparing the results of the 3-voltage-step protocol to results obtained with a well-established two-electrode voltage clamp (TEVC). In the context of the 2nd Swiss Parabolic Flight Campaign, we tested the OoClamp and the method. The setup and experiment protocol worked well in parabolic flight. A tendency that the calcium-dependent current was smaller under microgravity than under 1 g condition could be observed. However, a conclusive statement was not possible due to the small size of the data base that could be gathered.

Enhancement of oral bioavailability of atorvastatin calcium by self-emulsifying drug delivery systems (SEDDS).

PubMed

Kadu, Pawan J; Kushare, Sachin S; Thacker, Dhaval D; Gattani, Surendra G

2011-02-01

The aim of the present study was to formulate a self-emulsifying drug delivery system of atorvastatin calcium and its characterization including in vitro and in vivo potential. The solubility of atorvastatin calcium was determined in various vehicles such as Captex 355, Captex 355 EP/NF, Ethyl oleate, Capmul MCM, Capmul PG-8, Gelucire 44/14, Tween 80, Tween 20, and PEG 400. Pseudoternary phase diagrams were plotted on the basis of solubility data of drug in various components to evaluate the microemulsification region. Formulation development and screening was carried out based on results obtained from phase diagrams and characteristics of resultant microemulsion. Prepared formulations were tested for microemulsifying properties and evaluated for clarity, precipitation, viscosity determination, drug content and in vitro dissolution. The optimized formulation further evaluated for particle size distribution, zeta potential, stability studies and in vivo potential. In vivo performance of the optimized formulation was evaluated using a Triton-induced hypercholesterolemia model in male Albino Wistar rats. The formulation significantly reduced serum lipid levels as compared with atorvastatin calcium. Thus studies illustrated the potential use for the delivery of hydrophobic drug such as atorvastatin calcium by oral route.

Calcium antagonists modulate oxidative stress and acrosomal reaction in rat spermatozoa.

PubMed

Morakinyo, Ayodele; Iranloye, Bolanle; Adegoke, Olufeyisipe

2011-08-01

Calcium ions are vital in many biological processes and qualify as an almost ubiquitous intracellular second messenger. This indicates the multiplicity of the effects associated with drug actions aimed at interfering with calcium ions. To examine the cellular process involved in the induction of infertility in males by calcium antagonist (CA) even in the presence of normal semen parameters, we studied the effects of different CA namely; nifedipine, verapamil and diltiazem on oxidative balance and acrosome reaction in the sperm. For this purpose, lipid peroxidation, antioxidants such as superoxide dismutase, catalase and reduced glutathione, and acrosomal reaction were determined in sperm samples of rats. Calcium antagonist causes significant oxidative stress in the epididymal sperm with increased malondialdehyde level and a concomitant decrease in antioxidant activities of catalase and superoxide dismutase. The percentage value of acrosomal-reacted sperm in the nifedipine, verapamil and diltiazem-treated rats were 41 ±2.45, 39 ±2.92 and 42 ±1.22 respectively, compared with the control group value of 86 ±2.92. It appears CA oxidatively modify the sperm resulting in functional inhibition of acrosomal reaction. Suppression of the sperm acrosomal reaction is known to have serious adverse implications for fertilization.

Calcium in drinking water: effect on iron stores in Danish blood donors-results from the Danish Blood Donor Study.

PubMed

Rigas, Andreas S; Ejsing, Benedikte H; Sørensen, Erik; Pedersen, Ole B; Hjalgrim, Henrik; Erikstrup, Christian; Ullum, Henrik

2018-06-01

Studies confirm that calcium inhibits iron absorption. Danish tap water comes from groundwater, which contains varying amounts of calcium depending on the subsoil. We investigated the association of calcium in drinking water with iron levels in Danish blood donors. We used data on Danish blood donors including dietary and lifestyle habits, blood donation history, and physiologic characteristics including measures of ferritin levels along with information on area of residence from The Danish Blood Donor Study. Data on calcium levels in groundwater ("water hardness") were obtained through the Geological Survey of Denmark and Greenland. We performed multiple linear and logistic regression analyses to evaluate the effect of water hardness on ferritin levels and risk of having iron deficiency (defined as ferritin levels <15 ng/mL), stratified by sex. There was a significant negative association between water hardness and ferritin levels in both men and women. Risk of iron deficiency was correspondingly increased in both men (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.14-2.12) and women (OR, 1.20; 95% CI, 1.03-1.40) with increasing water hardness. In analyses restricted to individuals who received supplemental iron tablets no significant association between groundwater hardness and ferritin levels was observed. As measured by ferritin levels, residential drinking water calcium content is associated with blood donors- iron levels and risk of iron deficiency. However, effect sizes are small. © 2018 AABB.

Citrate salts for preventing and treating calcium containing kidney stones in adults.

PubMed

Phillips, Rebecca; Hanchanale, Vishwanath S; Myatt, Andy; Somani, Bhaskar; Nabi, Ghulam; Biyani, C Shekhar

2015-10-06

Kidney stones affect people worldwide and have a high rate of recurrence even with treatment. Recurrences are particularly prevalent in people with low urinary citrate levels. These people have a higher incidence of calcium phosphate and calcium oxalate stones. Oral citrate therapy increases the urinary citrate levels, which in turn binds with calcium and inhibits the crystallisation thus reduces stone formation. Despite the widespread use of oral citrate therapy for prevention and treatment of calcium oxalate stones, the evidence to support its clinical efficacy remains uncertain. The objective of this review was to determine the efficacy and adverse events associated with citrate salts for the treatment and prevention of calcium containing kidney stones. We searched the Cochrane Kidney and Transplant Specialised Register to 29 July 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review. We included randomised controlled trials (RCTs) that assessed the efficacy and adverse events associated with citrate salts for the treatment and prevention of calcium containing kidney stones in adults treated for a minimum of six months. Two authors assessed studies for inclusion in this review. Data were extracted according to predetermined criteria. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. We included seven studies that included a total of 477 participants, most of whom had oxalate stones. Of these, three studies (247 participants) compared potassium citrate with placebo or no intervention; three (166 participants) compared potassium-sodium citrate with no intervention; and one (64 participants) compared potassium-magnesium citrate with placebo. Overall, quality of the reporting of the included studies was considered moderate to poor, and there was a high risk of attrition bias in two studies.Compared with placebo or no intervention, citrate therapy significantly reduced the stone size (4 studies, 160 participants: RR 2.35, 95% CI 1.36 to 4.05). New stone formation was significantly lower with citrate therapy compared to control (7 studies, 324 participants: RR 0.26, 95% CI 0.10 to 0.68). The beneficial effect on stone size stability was also evident (4 studies, 160 participants: RR 1.97, 95% CI 1.19 to 3.26). Adverse events were reported in four studies, with the main side effects being upper gastrointestinal disturbance and one patient reported a rash. There were more gastrointestinal adverse events in the citrate group; however this was not significant (4 studies, 271 participants: RR 2.55, 95% CI 0.71 to 9.16). There were significantly more dropouts due to adverse events with citrate therapy compared to control (4 studies, 271 participants: RR 4.45, 95% CI 1.28 to 15.50). The need for retreatment was significantly less with citrate therapy compared to control (2 studies, 157 participants: RR 0.22, 95% CI 0.06 to 0.89). Citrate salts prevent new stone formation and reduce further stone growth in patients with residual stones that predominantly contain oxalate. The quality of reported literature remains moderate to poor; hence a well-designed statistically powered multi-centre RCT is needed in order to answer relevant questions concerning the efficacy of citrate salts.

Hyperthyroidism-associated hypercalcemic crisis: A case report and review of the literature.

PubMed

Chen, Ke; Xie, Yanhong; Zhao, Liling; Mo, Zhaohui

2017-01-01

Hyperthyroidism is one of the major clinical causes of hypercalcaemia, however, hyperthyroidism-related hypercalcemic crisis is rare, only 1 case have been reported. The potential mechanisms are still not too clear. It may be related that thyroid hormone stimulate bone turnover, elevate serum calcium, increase urinary and fecal calcium excretion. A 58-year-old female patient was found to have Graves' disease, a marked elevated serum calcium level (adjusted serum calcium: 3.74 mmol/L), and reduced parathyroid hormone level. She was diagnosed as hyperthyroidism-associated hypercalcemic crisis. Treatment with methimazole to correct the hyperthyroidism and treatment of the patient's hypercalcaemia was achieved by physiological saline, salmon calcitonin and furosemide. After treatment for hypercalcaemia and hyperthyroidism, her symptoms and serum calcium levels quickly returned to normal. hyperthyroid-associated hypercalcaemia crisis is rare, however, the diagnosis should pay attention to screening for other diseases caused by hypercalcemia. Timely treatment of hypercalcaemia is a critical step for rapidly control of symptoms, and treatment of hyperthyroidism is beneficial to relief the symptoms and maintain the blood calcium level.

Effects of storage time on the motility, mortality and calcium levels of Atlantic salmon Salmo salar spermatozoa.

PubMed

Parodi, J; Guerra, G; Cuevas, M; Ramírez-Reveco, A; Romero, F

2017-04-01

This study estimates spermatozoa mortality, morphology, motility and intracellular calcium levels in Atlantic salmon Salmo salar milt after prolonged storage. Milt samples were preserved at 4° C for 25 days and then evaluated for mortality. Motility remained high for the first 3 days and the mortality was low during the first 5 days of storage. A decrease of >50% in calcium content was observed after 5 days of storage. When spermatozoa were activated, calcium levels increased >200% in relative fluorescence units (RFU); this rate of increase was lost when the samples were stored for extended periods of time and was only partially manifested in a zero calcium solution. The results suggest that in vitro storage of S. salar spermatozoa at 4° C for a period of 3 days preserves motility and limits mortality to levels similar to those of fresh spermatozoa. This method also maintains intracellular calcium storage critical for spermatozoa performance. © 2017 The Fisheries Society of the British Isles.

Further improvement in ganoderic acid production in static liquid culture of Ganoderma lucidum by integrating nitrogen limitation and calcium ion addition.

PubMed

Li, Huan-Jun; Zhang, De-Huai; Han, Li-Liang; Yu, Xuya; Zhao, Peng; Li, Tao; Zhong, Jian-Jiang; Xu, Jun-Wei

2016-01-01

To further improve the ganoderic acid (GA) production, a novel integrated strategy by combining nitrogen limitation and calcium ion addition was developed. The effects of the integrated combination on the content of GA-T (one powerful anticancer compound), their intermediates (squalene and lanosterol) and on the transcription levels of GA biosynthetic genes in G. lucidum fermentation were investigated. The maximum GA-T content with the integrated strategy were 1.87 mg/ 100 mg dry cell weight, which was 2.1-4.2 fold higher than that obtained with either calcium ion addition or nitrogen limitation alone, and it is also the highest record as ever reported in submerged fermentation of G. lucidum. The squalene content was increased by 3.9- and 2.2-fold in this case compared with either individual strategy alone. Moreover, the transcription levels of the GA biosynthetic genes encoding 3-hydroxy-3-methyglutaryl coenzyme A reductase and lanosterol synthase were also up-regulated by 3.3-7.5 and 1.3-2.3 fold, respectively.

Hypoparathyroidism: what is the best calcium carbonate supplementation intake form?

PubMed

Gollino, Loraine; Biagioni, Maria Fernanda Giovanetti; Sabatini, Nathalia Regina; Tagliarini, José Vicente; Corrente, José Eduardo; Paiva, Sérgio Alberto Rupp de; Mazeto, Gláucia Maria Ferreira da Silva

2017-11-15

In hypoparathyroidism, calcium supplementation using calcium carbonate is necessary for the hypocalcemia control. The best calcium carbonate intake form is unknown, be it associated with feeding, juice or in fasting. The objective was to evaluate the calcium, phosphorus and Calcium×Phosphorus product serum levels of hypoparathyroidism women after total thyroidectomy, following calcium carbonate intake in three different forms. A crossover study was carried out with patients presenting definitive hypoparathyroidism, assessed in different situations (fasting, with water, orange juice, breakfast with a one-week washout). Through the review of clinical data records of tertiary hospital patients from 1994 to 2010, 12 adult women (18 50 years old) were identified and diagnosed with definitive post-thyroidectomy hypoparathyroidism. The laboratory results of calcium and phosphorus serum levels dosed before and every 30min were assessed, for 5h, after calcium carbonate intake (elementary calcium 500mg). The maximum peak average values for calcium, phosphorus and Calcium×Phosphorus product were 8.63mg/dL (water), 8.77mg/dL (orange juice) and 8.95mg/dL (breakfast); 4.04mg/dL (water), 4.03mg/dL (orange juice) and 4.12mg/dL (breakfast); 34.3mg 2 /dL 2 (water), 35.8mg 2 /dL 2 (orange juice) and 34.5mg 2 /dL 2 (breakfast), respectively, and the area under the curve 2433mg/dLmin (water), 2577mg/dLmin (orange juice) and 2506mg/dLmin (breakfast), 1203mg/dLmin (water), 1052mg/dLmin (orange juice) and 1128mg/dLmin (breakfast), respectively. There was no significant difference among the three different tests (p>0.05). The calcium, phosphorus and Calcium×Phosphorus product serum levels evolved in a similar fashion in the three calcium carbonate intake forms. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Effect of calcium chloride treatments on calcium content, anthracnose severity and antioxidant activity in papaya fruit during ambient storage.

PubMed

Madani, Babak; Mirshekari, Amin; Yahia, Elhadi

2016-07-01

There have been no reports on the effects of preharvest calcium application on anthracnose disease severity, antioxidant activity and cellular changes during ambient storage of papaya, and therefore the objective of this study was to investigate these effects. Higher calcium concentrations (1.5 and 2% w/v) increased calcium concentration in the peel and pulp tissues, maintained firmness, and reduced anthracnose incidence and severity. While leakage of calcium-treated fruit was lower for 1.5 and 2% calcium treatments compared to the control, microscopic results confirmed that pulp cell wall thickness was higher after 6 days in storage, for the 2% calcium treatment compared to the control. Calcium-treated fruit also had higher total antioxidant activity and total phenolic compounds during storage. Calcium chloride, especially at higher concentrations, is effective in maintaining papaya fruit quality during ambient storage. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

In vitro calcium availability in bakery products fortified with tuna bone powder as a natural calcium source.

PubMed

Nemati, Mahnaz; Kamilah, Hanisah; Huda, Nurul; Ariffin, Fazilah

2015-08-01

Avoidance of dairy products due to lactose intolerance can lead to insufficiency of calcium (Ca) in the body. In an approach to address this problem, tuna bone powder (TBP) was formulated as a calcium supplement to fortify bakery products. In a study, TBP recovered by alkaline treatment contained 38.16 g/100 g of calcium and 23.31 g/100 g of phosphorus. The ratio of Ca:P that was close to 2:1 was hence comparable to that in human bones. The availability of calcium in TBP was 53.93%, which was significantly higher than most calcium salts, tricalcium phosphate (TCP) being the exception. In vitro availability of calcium in TBP-fortified cookies or TCP-fortified cookies were comparable at 38.9% and 39.5%, respectively. These values were higher than the readings from TBP-fortified bread (36.7%) or TCP-fortified bread (37.4%). Sensory evaluation of bakery products containing TBP or TCP elicited comparable scores for the two additives from test panels. Hence, TBP could be used in the production of high calcium bakery products that would enjoy consumer acceptance.

Low-concentration hydrogen peroxide can upregulate keratinocyte intracellular calcium and PAR-2 expression in a human keratinocyte-melanocyte co-culture system.

PubMed

Li, Jian; Tang, Lu-Yan; Fu, Wen-Wen; Yuan, Jin; Sheng, You-Yu; Yang, Qin-Ping

2016-12-01

Hydrogen peroxide (H 2 O 2 ) may have a biphasic effect on melanin synthesis and melanosome transfer. High H 2 O 2 concentrations are involved in impaired melanosome transfer in vitiligo. However, low H 2 O 2 concentration promotes the beneficial proliferation and migration of melanocytes. The aim of this study was to explore low H 2 O 2 and its mechanism in melanosome transfer, protease-activated receptor-2 (PAR-2) expression and calcium balance. Melanosomes were fluorescein-labeled for clear visualization of their transfer. The expression of protease-activated receptor-2 (PAR-2) in keratinocytes was determined by western blot analysis. Flow cytometry was employed to evaluate the effects of H 2 O 2 on calcium levels in keratinocytes. Fluorescence microscopy showed the upregulation of melanosome transfer into keratinocytes following 0.3 mM H 2 O 2 treatment in the co-cultures rather than in the untreated control groups, which was associated with higher expression of PAR-2 protein and increased calcium concentration. The addition of a PAR-2 antagonist inhibited the positive activity of H 2 O 2 and calcium flow in keratinocytes. When calcium flow was blocked by a calcium chelator, the addition of H 2 O 2 did not increase the PAR-2 expression level in keratinocytes, therefore, inhibiting dendrite formation and melanosome transfer. Low H 2 O 2 concentration promotes melanosome transfer with increased PAR-2 expression level and calcium concentration in keratinocytes. In addition, the interaction between melanocytes and keratinocytes is more beneficial to enhance calcium levels in keratinocytes which mediate melanin transfer. Moreover, low H 2 O 2 concentration promotes dendrite formation, in which extracellular calcium and Par-2 were involved.

Monitoring Endoplasmic Reticulum Calcium Homeostasis Using a Gaussia Luciferase SERCaMP.

PubMed

Henderson, Mark J; Wires, Emily S; Trychta, Kathleen A; Yan, Xiaokang; Harvey, Brandon K

2015-09-06

The endoplasmic reticulum (ER) contains the highest level of intracellular calcium, with concentrations approximately 5,000-fold greater than cytoplasmic levels. Tight control over ER calcium is imperative for protein folding, modification and trafficking. Perturbations to ER calcium can result in the activation of the unfolded protein response, a three-prong ER stress response mechanism, and contribute to pathogenesis in a variety of diseases. The ability to monitor ER calcium alterations during disease onset and progression is important in principle, yet challenging in practice. Currently available methods for monitoring ER calcium, such as calcium-dependent fluorescent dyes and proteins, have provided insight into ER calcium dynamics in cells, however these tools are not well suited for in vivo studies. Our lab has demonstrated that a modification to the carboxy-terminus of Gaussia luciferase confers secretion of the reporter in response to ER calcium depletion. The methods for using a luciferase based, secreted ER calcium monitoring protein (SERCaMP) for in vitro and in vivo applications are described herein. This video highlights hepatic injections, pharmacological manipulation of GLuc-SERCaMP, blood collection and processing, and assay parameters for longitudinal monitoring of ER calcium.

Salivary mineral composition in patients with oral cancer.

PubMed

Dziewulska, Anna; Janiszewska-Olszowska, Joanna; Bachanek, Teresa; Grocholewicz, Katarzyna

2013-01-01

To analyse the mineral content of saliva in patients with oral cancer in order to identify possible markers that might aid the diagnosis of oral cancer. The study group consisted of 34 patients, aged 35-72 years with a diagnosis of oral cancer, including seven women and 27 men, before the start of treatment. Samples of unstimulated saliva were collected in plastic containers. The concentrations of sodium and potassium were assessed using ion selective electrodes, and the concentrations of calcium, magnesium, iron and phosphorus were assessed using colorimetric methods. Statistically significant differences between the study and control groups were found only for the concentration of sodium--higher concentrations were found in the study group. When comparing different cancer localisations, the highest levels of salivary sodium were found in cases of cancer of the floor of the oral cavity, and the lowest levels in tongue or parotid gland cancer. The highest calcium levels were found in cancer of the floor of the oral cavity, and the lowest levels in tongue cancer. The highest levels of magnesium were found in cancer of the floor of the oral cavity, and the lowest in tongue cancer. As regards the different histological types, higher sodium and calcium levels were found in squamous cell carcinomas than in other types. Salivary mineral content in patients with oral squamous cell carcinoma is indicative of oral dehydration; however, we found no evidence of any salivary mineral markers that would be useful for the diagnosis of oral cancer.

Supplemental calcium attenuates the colitis-related increase in diarrhea, intestinal permeability, and extracellular matrix breakdown in HLA-B27 transgenic rats.

PubMed

Schepens, Marloes A A; Schonewille, Arjan J; Vink, Carolien; van Schothorst, Evert M; Kramer, Evelien; Hendriks, Thijs; Brummer, Robert-Jan; Keijer, Jaap; van der Meer, Roelof; Bovee-Oudenhoven, Ingeborg M J

2009-08-01

We have shown in several controlled rat and human infection studies that dietary calcium improves intestinal resistance and strengthens the mucosal barrier. Reinforcement of gut barrier function may alleviate inflammatory bowel disease (IBD). Therefore, we investigated the effect of supplemental calcium on spontaneous colitis development in an experimental rat model of IBD. HLA-B27 transgenic rats were fed a purified high-fat diet containing either a low or high calcium concentration (30 and 120 mmol CaHPO4/kg diet, respectively) for almost 7 wk. Inert chromium EDTA (CrEDTA) was added to the diets to quantify intestinal permeability by measuring urinary CrEDTA excretion. Relative fecal wet weight was determined to quantify diarrhea. Colonic inflammation was determined histologically and by measuring mucosal interleukin (IL)-1beta. In addition, colonic mucosal gene expression of individual rats was analyzed using whole-genome microarrays. The calcium diet significantly inhibited the increase in intestinal permeability and diarrhea with time in HLA-B27 rats developing colitis compared with the control transgenic rats. Mucosal IL-1beta levels were lower in calcium-fed rats and histological colitis scores tended to be lower (P = 0.08). Supplemental calcium prevented the colitis-induced increase in the expression of extracellular matrix remodeling genes (e.g. matrix metalloproteinases, procollagens, and fibronectin), which was confirmed by quantitative real-time PCR and gelatin zymography. In conclusion, dietary calcium ameliorates several important aspects of colitis severity in HLA-B27 transgenic rats. Reduction of mucosal irritation by luminal components might be part of the mechanism. These results show promise for supplemental calcium as effective adjunct therapy for IBD.

Secretory pathway Ca2+/Mn2+-ATPase isoform 2 and lactation: specific localization of plasmalemmal and secretory pathway Ca2+ pump isoforms in the mammary gland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faddy, Helen M.; Smart, Chanel E.; Xu, Ren

2008-04-09

The supply of calcium to the developing neonate via milk is an important physiological process. Until recently the mechanism for the enrichment of milk with calcium was thought to be almost entirely mediated via the secretory pathway. However, recent studies suggest that a specific isoform of the plasma membrane calcium ATPase, PMCA2, is the primary mechanism for calcium transport into milk, highlighting a major role for apical calcium transport. We compared the expression of the recently identified secretory calcium ATPase, SPCA2, and SPCA1, in the mouse mammary gland during different stages of development. SPCA2 levels increased over 35 fold duringmore » lactation, while SPCA1 increased only a modest two fold. The potential importance of SPCA2 in lactation was also highlighted by its localization to luminal secretory cells of the mammary gland during lactation, while SPCA1 was expressed throughout the cells of the mammary gland. We also observed major differences in the localization of PMCA2 and PMCA1 during lactation. Using the SCp2 mouse mammary epithelial cell 3D culture model, differences in the sub-cellular distribution of PMCA2 and PMCA1 were clear. These studies highlight the likely specific roles of PMCA2 and SPCA2 in lactation, and link the recently characterized SPCA2 calcium pump to the supply of calcium into milk and the regulation of Golgi resident enzymes important in lactation. They also indicate that calcium transport into milk is a complex interplay between apical and secretory pathways.« less

Effects of Ghrelin miRNA on Inflammation and Calcium Pathway in Pancreatic Acinar Cells of Acute Pancreatitis.

PubMed

Tang, Xiping; Tang, Guodu; Liang, Zhihai; Qin, Mengbin; Fang, Chunyun; Zhang, Luyi

The study investigated the effects of endogenous targeted inhibition of ghrelin gene on inflammation and calcium pathway in an in vitro pancreatic acinar cell model of acute pancreatitis. Lentiviral expression vector against ghrelin gene was constructed and transfected into AR42J cells. The mRNA and protein expression of each gene were detected by reverse transcription polymerase chain reaction, Western blotting, or enzyme-linked immunosorbent assay. The concentration of intracellular calcium ([Ca]i) was determined by calcium fluorescence mark probe combined with laser scanning confocal microscopy. Compared with the control group, cerulein could upregulate mRNA and protein expression of inflammatory factors, calcium pathway, ghrelin, and [Ca]i. mRNA and protein expression of inflammatory factors increased significantly in cells transfected with ghrelin miRNA compared with the other groups. Intracellular calcium and expression of some calcium pathway proteins decreased significantly in cells transfected with ghrelin miRNA compared with the other groups. Targeted inhibition of ghrelin gene in pancreatic acinar cells of acute pancreatitis can upregulate the expression of the intracellular inflammatory factors and alleviate the intracellular calcium overload.

Interpreting the Marine Calcium Isotope Record: Influence of Reef Builders

NASA Astrophysics Data System (ADS)

Boehm, F.; Eisenhauer, A.; Farkas, J.; Kiessling, W.; Veizer, J.; Wallmann, K.

2008-12-01

The calcium isotopic composition of seawater as recorded in brachiopod shells varied substantially during the Paleozoic (Farkas et al. 2007, Geochim. Cosmochim. Acta, 71, 5117-5134). The most prominent feature of the record is an excursion to higher 44Ca/40Ca values that started during the Early Carboniferous and lasted until the Permian. The shift occurred shortly after the transition from a calcite-sea to an aragonite-sea (Sandberg 1983, Nature 305, 19-22; Stanley and Hardie 1998, Pal3, 144, 3-19). It therefore has been interpreted to reflect a change in the average calcium isotope fractionation of carbonates produced in the oceans. Aragonite is depleted by about 0.6 permil in 44Ca/40Ca compared to calcite (Gussone et al. 2005, Geochim. Cosmochim. Acta, 69, 4485-4494). Consequently a transient shift from calcite dominated to an aragonite dominated calcium carbonate sedimentation could have caused the observed 0.5 permil isotope shift. We compare the marine calcium isotope record with a new compilation of the Phanerozoic trends in the skeletal mineralogy of marine invertebrates (Kiessling et al. 2008, Nature Geoscience, 1, 527-530). The compilation is based on data collected in the PaleoReef database and the Paleobiology Database, which include information on Phanerozoic reef complexes and taxonomic collection data of Phanerozoic biota, respectively. We find a strong positive correlation between the calcium isotope ratios and the abundance of aragonitic reef builders from the Silurian until the Permian at a sample resolution of about 10 million years. The two records, however, diverge in the Triassic, when reefs were dominated by aragonite but the calcium isotope values remained at a relatively low level. We also find a good correlation between calcium isotopes and the proportion of aragonite in the general record of Phanerozoic biota. However, in this case the records start to diverge already in the latest Carboniferous. The observations suggest that the Paleozoic calcium isotope record was indeed strongly controlled by the skeletal mineralogy of the major carbonate producers. The collapse of the correlation in the late Paleozoic points to the evolution of new biocalcification mechanisms that allowed a more strict biological control of the calcium fluxes in the calcifying biota (sensu Gussone et al. 2006, Geology, 34, 625-628).

Effects of calcium-vitamin D co-supplementation on metabolic profiles in vitamin D insufficient people with type 2 diabetes: a randomised controlled clinical trial.

PubMed

Tabesh, Marjan; Azadbakht, Leila; Faghihimani, Elham; Tabesh, Maryam; Esmaillzadeh, Ahmad

2014-10-01

This study was performed to assess the effects of vitamin D and calcium supplementation on the metabolic profiles of vitamin D insufficient persons with type 2 diabetes. In a parallel designed randomised placebo-controlled clinical trial, a total of 118 non-smoker individuals with type 2 diabetes and insufficient 25-hydroxyvitamin D, aged >30 years, were recruited from the Isfahan Endocrine and Metabolism Research Centre. Participants were randomly assigned to four groups receiving: (1) 50,000 U/week vitamin D + calcium placebo; (2) 1,000 mg/day calcium + vitamin D placebo; (3) 50,000 U/week vitamin D + 1,000 mg/day calcium; or (4) vitamin D placebo + calcium placebo for 8 weeks. A study technician carried out the random allocations using a random numbers table. All investigators, participants and laboratory technicians were blinded to the random assignments. All participants provided 3 days of dietary records and 3 days of physical activity records throughout the intervention. Blood samples were taken to quantify glycaemic and lipid profiles at study baseline and after 8 weeks of intervention. 30 participants were randomised in each group. During the intervention, one participant from the calcium group and one from the vitamin D group were excluded because of personal problems. Calcium-vitamin D co-supplementation resulted in reduced serum insulin (changes from baseline: -14.8 ± 3.9 pmol/l, p = 0.01), HbA1c [-0.70 ± 0.19% (-8.0 ± 0.4 mmol/mol), p = 0.02], HOMA-IR (-0.46 ± 0.20, p = 0.001), LDL-cholesterol (-10.36 ± 0.10 mmol/l, p = 0.04) and total/HDL-cholesterol levels (-0.91 ± 0.16, p = 0.03) compared with other groups. We found a significant increase in QUICKI (0.025 ± 0.01, p = 0.004), HOMA of beta cell function (HOMA-B; 11.8 ± 12.17, p = 0.001) and HDL-cholesterol (0.46 ± 0.05 mmol/l, p = 0.03) in the calcium-vitamin D group compared with others. Joint calcium and vitamin D supplementation might improve the glycaemic status and lipid profiles of vitamin D insufficient people with type 2 diabetes. ClinicalTrials.gov NCT01662193 FUNDING: Clinical Research Council, Isfahan University of Medical Sciences, Isfahan, Iran.

INCREASES IN CYTOSOLIC CALCIUM ION LEVELS IN HUMAN NATURAL KILLER CELLS IN RESPONSE TO BUTYLTIN EXPOSURE

PubMed Central

Lane, Rhonda; Ghazi, Sabah O.; Whalen, Margaret M.

2009-01-01

This study investigated whether exposures to butyltins (BTs), tributylin (TBT) and dibutyltin (DBT) were able to alter cytosolic calcium levels in human natural killer (NK) cells. Additionally, the effects of cytosolic calcium ion increases on the activation state of mitogen activated protein kinases (MAPKs) in NK cells were also investigated. NK cells are an intital immune defense against the development of tumors or viral infections. TBT and DBT are widespread environmental contaminants, due to their various industrial applications. Both TBT and DBT have been shown to decrease the ability of NK cells to lyse tumor cells (lytic function). TBT has also been shown to activate MAPKs in NK cells. The results of this study indicated that TBT increased cytosolic calcium levels by as much as 100% after a 60 min exposure to 500 nM TBT while DBT increased cytosolic calcium levels to a much smaller extent (and required higher concentrations). The results also indicated that increases in cytosolic calcium could activate MAPKs but only for a short period of time (5 min), while previous studies showed that activation of MAPKs by TBT last for at least 6 hours. Thus, it appears that TBT stimulated increases in cytosolic calcium may contribute to, but are not fully responsible for, TBT-induced activation of MAPKs. PMID:19365649

FGF-23 dysregulates calcium homeostasis and electrophysiological properties in HL-1 atrial cells.

PubMed

Kao, Yu-Hsun; Chen, Yao-Chang; Lin, Yung-Kuo; Shiu, Rong-Jie; Chao, Tze-Fan; Chen, Shih-Ann; Chen, Yi-Jen

2014-08-01

Fibroblast growth factor (FGF)-23 is a key regulator of phosphate homeostasis. Higher FGF-23 levels are correlated with poor outcomes in cardiovascular diseases. FGF-23 can produce cardiac hypertrophy and increase intracellular calcium, which can change cardiac electrical activity. However, it is not clear whether FGF-23 possesses arrhythmogenic potential through calcium dysregulation. Therefore, the purposes of this study were to evaluate the electrophysiological effects of FGF-23 and identify the underlying mechanisms. Patch clamp, confocal microscope with Fluo-4 fluorescence, and Western blot analyses were used to evaluate the electrophysiological characteristics, calcium homeostasis and calcium regulatory proteins in HL-1 atrial myocytes with and without FGF-23 (10 and 25 ng/mL) incubation for 24 h. FGF-23 (25 ng/mL) increased L-type calcium currents, calcium transient and sarcoplasmic reticulum Ca(2+) contents in HL-1 cells. FGF-23 (25 ng/mL)-treated cells (n = 14) had greater incidences (57%, 17% and 15%, P < 0·05) of delayed afterdepolarizations than control (n = 12) and FGF-23 (10 ng/mL)-treated cells (n = 13). Compared with control cells, FGF-23 (25 ng/mL)-treated cells (n = 14) exhibited increased phosphorylation of calcium/calmodulin-dependent protein kinase IIδ and phospholamban (PLB) at threonine 17 but had similar phosphorylation extents of PLB at serine 16, total PLB and sarcoplasmic reticulum Ca(2+) -ATPase protein. Moreover, the FGF receptor inhibitor (PD173074, 10 nM), calmodulin inhibitor (W7, 5 μM) and phospholipase C inhibitor (U73122, 1 μM) attenuated the effects of FGF-23 on calcium/calmodulin-dependent protein kinase II phosphorylation. FGF-23 increases HL-1 cells arrhythmogenesis with calcium dysregulation through modulating calcium-handling proteins. © 2014 Stichting European Society for Clinical Investigation Journal Foundation.

Calcium/vitamin D supplementation and coronary artery calcification in the Women's Health Initiative.

PubMed

Manson, JoAnn E; Allison, Matthew A; Carr, J Jeffrey; Langer, Robert D; Cochrane, Barbara B; Hendrix, Susan L; Hsia, Judith; Hunt, Julie R; Lewis, Cora E; Margolis, Karen L; Robinson, Jennifer G; Rodabough, Rebecca J; Thomas, Asha M

2010-07-01

Coronary artery calcified plaque is a marker for atheromatous plaque burden and predicts future risk of cardiovascular events. The relationship between calcium plus vitamin D (calcium/D) supplementation and coronary artery calcium (CAC) has not been previously assessed in a randomized trial setting. We compared CAC scores after trial completion between women randomized to calcium/vitamin D supplementation and women randomized to placebo. In an ancillary substudy of women randomized to calcium carbonate (1,000 mg of elemental calcium daily) plus vitamin D3 (400 IU daily) or placebo, nested within the Women's Health Initiative trial of estrogen among women who underwent hysterectomy, we measured CAC with cardiac CT in 754 women aged 50 to 59 years at randomization. Imaging for CAC was performed at 28 of 40 centers after a mean of 7 years of treatment, and scans were read centrally. CAC scores were measured by a central reading center with masking to randomization assignments. Posttrial CAC measurements were similar in women randomized to calcium/D supplementation and those receiving placebo. The mean CAC score was 91.6 for women receiving calcium/D and 100.5 for women receiving placebo (rank test P value = 0.74). After adjustment for coronary risk factors, multivariate odds ratios for increasing CAC score cutpoints (CAC >0, > or =10, and > or =100) for calcium/D versus placebo were 0.92 (95% CI, 0.64-1.34), 1.29 (0.88-1.87), and 0.90 (0.56-1.44), respectively. Corresponding odds ratios among women with a 50% or higher adherence to study pills and for higher levels of CAC (>300) were similar. Treatment with moderate doses of calcium plus vitamin D3 did not seem to alter coronary artery calcified plaque burden among postmenopausal women. Whether higher or lower doses would affect this outcome remains uncertain.

Calcium Blood Test

MedlinePlus

... Your health care provider may order a calcium test if you have a pre-existing condition that may affect your calcium levels. These include: Kidney disease Thyroid disease Malnutrition Certain types of cancer What happens during a calcium blood test? A health care professional will take a blood ...

Nephrocalcinosis

MedlinePlus

... Blood tests to check levels of calcium, phosphate, uric acid, and parathyroid hormone Urinalysis to see crystals and ... to measure acidity and levels of calcium, sodium, uric acid, oxalate, and citrate

New agent to treat elevated phosphate levels: magnesium carbonate/calcium carbonate tablets.

PubMed

Meyer, Caitlin; Cameron, Karen; Battistella, Marisa

2012-01-01

In summary, Binaphos CM, a magnesium carbonate/calcium carbonate combination phosphate binder, is marketed for treating elevated phosphate levels in dialysis patients. Although studies using magnesium/calcium carbonate as a phosphate binder are short term with small numbers of patients, this phosphate binder has shown some promising results and may provide clinicians with an alternative for phosphate binding. Using a combination phosphate binder may reduce pill burden and encourage patient compliance. In addition to calcium and phosphate, it is imperative to diligently monitor magnesium levels in patients started on this medication, as magnesium levels may increase with longer duration of use. Additional randomized controlled trials are necessary to evaluate long-term efficacy and safety of this combination phosphate binder.

Vitamin D deficiency remains prevalent despite increased laboratory testing in New South Wales, Australia

PubMed Central

Quaggiotto, Paul; Tran, Huy; Bhanugopan, Marie

2014-01-01

INTRODUCTION The aim of the present study was to assess the prevalence of vitamin D deficiency and toxicity, the frequency of 25-hydroxyvitamin D (25[OH]D) testing, and 25(OH)D variations with respect to patient gender, patient age and season in New South Wales, Australia. METHODS A retrospective analysis of pathology records was performed to ascertain patient age, patient gender, sample collection date, plasma or serum 25(OH)D levels, calcium and parathyroid hormone (PTH) levels, and test numbers between 2001 and 2010. Linear regression with Bonferroni correction was used to calculate and compare age- adjusted mean 25(OH)D levels. Relationships of 25(OH)D with PTH and calcium were tested using Spearman’s rank correlation. RESULTS 25(OH)D testing increased by 730% over the ten-year study period. In 2010, many men (33%) and women (40%) were, to some degree, vitamin D deficient (≤ 50 nmol/L). Vitamin D toxicity was rare, with only one instance noted. 25(OH)D levels correlated positively with calcium and negatively with PTH levels. 25(OH)D levels decreased with age. In 2010, 25(OH)D levels were highest in February and lowest in September/October. Cyclical variation was observed for 25(OH)D levels between 2006 and 2010. CONCLUSION We found that vitamin D deficiency was prevalent in both men and women, with a higher prevalence in the latter, despite the substantial increased demand for 25(OH)D testing in our population over the decade. Vitamin D deficiency was associated with elevated PTH levels. Vitamin D toxicity was rare and only observed once during our study period. 25(OH)D levels decreased with age and varied with season, with the highest levels observed in late summer and the lowest in early spring. PMID:24862752

Does dairy calcium intake enhance weight loss among overweight diabetic patients?

PubMed

Shahar, Danit R; Abel, Relly; Elhayany, Asher; Vardi, Hillel; Fraser, Drora

2007-03-01

To examine the effect of dairy calcium consumption on weight loss and improvement in cardiovascular disease (CVD) and diabetes indicators among overweight diabetic patients. This was an ancillary study of a 6-month randomized clinical trial assessing the effect of three isocaloric diets in type 2 diabetic patients: 1) mixed glycemic index carbohydrate diet, 2) low-glycemic index diet, and 3) modified Mediterranean diet. Low-fat dairy product consumption varied within and across the groups by personal choice. Dietary intake, weight, CVD risk factors, and diabetes indexes were measured at baseline and at 6 months. A total of 259 diabetic patients were recruited with an average BMI >31 kg/m2 and mean age of 55 years. No difference was found at baseline between the intervention groups in CVD risk factors, diabetes indicators, macronutrient intake, and nutrient intake from dairy products. Dairy calcium intake was associated with percentage of weight loss. Among the high tertile of dairy calcium intake, the odds ratio for weight loss of >8% was 2.4, P = 0.04, compared with the first tertile, after controlling for nondairy calcium intake, diet type, and the change in energy intake from baseline. No association was noted between dairy calcium and other health indexes except for triglyceride levels. A diet rich in dairy calcium intake enhances weight reduction in type 2 diabetic patients. Such a diet could be tried in diabetic patients, especially those with difficulty adhering to other weight reduction diets.

The influence of phosphate, calcium and magnesium on matrix Gla-protein and vascular calcification: a systematic review.

PubMed

Houben, E; Neradova, A; Schurgers, L J; Vervloet, Marc

2016-01-01

Vitamin K-dependent matrix Gla protein (MGP) is a key inhibitor of vascular calcification (VC). MGP is synthesized by chondrocytes and vascular smooth muscle cells (VSMC) and the absence or inactivity of MGP results in excessive calcification of both growth plate and vasculature. Apart from its vitamin K dependency little is known about other factors that influence MGP metabolism. Phosphate, calcium and magnesium are involved in bone mineralization and play an important role in VC. In this review we provide a summary of the effect of phosphate, calcium, and magnesium on MGP metabolism. Elevated phosphate and calcium levels promote VC, in part by increasing the release of matrix vesicles (MV) that under the influence of calcium and phosphate become calcification competent. Phosphate and calcium simultaneously induce an upregulation of MGP protein and gene expression, which possibly inhibits calcification. Elevated phosphate levels did not change MGP protein levels in MV. On the contrary, elevated calcium concentrations caused a decrease of MGPloading in MV, which might in part explainthe calcifying effects of MV. Magnesium is a known inhibitor of VC. However, magnesium has been shown to have an inhibitory effect on MGP synthesis induced through downregulation of the calcium-sensing receptor and hereby causing a decrease in calcium induced MGP upregulation. There might also be stimulatory effect of magnesium on MGP in which the TRPM7 channel is involved. In conclusion there is a clear interaction between MGP and phosphate, calcium and magnesium. The upregulation of MGP by phosphate and calcium might be a cellular response that possibly results in the mitigation of VC.

Preferential Ty1 retromobility in mother cells and nonquiescent stationary phase cells is associated with increased concentrations of total Gag or processed Gag and is inhibited by exposure to a high concentration of calcium.

PubMed

Peifer, Andrew C; Maxwell, Patrick H

2018-03-21

Retrotransposons are abundant mobile DNA elements in eukaryotic genomes that are more active with age in diverse species. Details of the regulation and consequences of retrotransposon activity during aging remain to be determined. Ty1 retromobility in Saccharomyces cerevisiae is more frequent in mother cells compared to daughter cells, and we found that Ty1 was more mobile in nonquiescent compared to quiescent subpopulations of stationary phase cells. This retromobility asymmetry was absent in mutant strains lacking BRP1 that have reduced expression of the essential Pma1p plasma membrane proton pump, lacking the mRNA decay gene LSM1 , and in cells exposed to a high concentration of calcium. Mother cells had higher levels of Ty1 Gag protein than daughters. The proportion of protease-processed Gag decreased as cells transitioned to stationary phase, processed Gag was the dominant form in nonquiescent cells, but was virtually absent from quiescent cells. Treatment with calcium reduced total Gag levels and the proportion of processed Gag, particularly in mother cells. We also found that Ty1 reduced the fitness of proliferating but not stationary phase cells. These findings may be relevant to understanding regulation and consequences of retrotransposons during aging in other organisms, due to conserved impacts and regulation of retrotransposons.

Preferential Ty1 retromobility in mother cells and nonquiescent stationary phase cells is associated with increased concentrations of total Gag or processed Gag and is inhibited by exposure to a high concentration of calcium

PubMed Central

Peifer, Andrew C.

2018-01-01

Retrotransposons are abundant mobile DNA elements in eukaryotic genomes that are more active with age in diverse species. Details of the regulation and consequences of retrotransposon activity during aging remain to be determined. Ty1 retromobility in Saccharomyces cerevisiae is more frequent in mother cells compared to daughter cells, and we found that Ty1 was more mobile in nonquiescent compared to quiescent subpopulations of stationary phase cells. This retromobility asymmetry was absent in mutant strains lacking BRP1 that have reduced expression of the essential Pma1p plasma membrane proton pump, lacking the mRNA decay gene LSM1, and in cells exposed to a high concentration of calcium. Mother cells had higher levels of Ty1 Gag protein than daughters. The proportion of protease-processed Gag decreased as cells transitioned to stationary phase, processed Gag was the dominant form in nonquiescent cells, but was virtually absent from quiescent cells. Treatment with calcium reduced total Gag levels and the proportion of processed Gag, particularly in mother cells. We also found that Ty1 reduced the fitness of proliferating but not stationary phase cells. These findings may be relevant to understanding regulation and consequences of retrotransposons during aging in other organisms, due to conserved impacts and regulation of retrotransposons. PMID:29562219

Inflammatory cytokine response to titanium chemical composition and nanoscale calcium phosphate surface modification.

PubMed

Hamlet, Stephen; Ivanovski, Saso

2011-05-01

Nanoscale surface modification of titanium dental implants with calcium phosphate (CaP) has been shown to achieve superior bone wound healing and osseointegration compared with smooth or microrough titanium surfaces alone. As bone healing has been shown to be influenced by the action of cytokines, this study examined whether changes in cytokine gene expression from RAW 264.7 cells cultured on commercially pure and titanium alloy (Ti-6Al-4V) microrough or nanoscale crystalline CaP-modified surfaces, may influence downstream events in bone wound healing and osseointegration. Whilst no significant difference in the attachment or proliferation of RAW 264.7 cells was observed, the nanoscale CaP-modified surface elicited a gene expression profile with marked down-regulation of a number of pro-inflammatory cytokines and chemokines. Inflammatory cytokine gene expression was further influenced by chemical composition, with lower levels of pro-inflammatory markers noted following exposure of the macrophage-like cells to titanium alloy (Ti-6Al-4V) compared with the commercially pure titanium surface. Down-regulation of pro-inflammatory cytokine gene expression (confirmed at the protein level for TNFα and CCL5), may thus facilitate the enhanced bone wound healing and osseointegration observed clinically with nanoscale calcium phosphate-modified implant surfaces. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Compromised zinc status of experimental rats as a consequence of prolonged iron & calcium supplementation.

PubMed

Jayalakshmi, S; Platel, Kalpana

2016-02-01

Iron supplementation is usually given to pregnant and lactating women who may also have marginal deficiency of zinc. The negative impact of supplemental iron and calcium on zinc status is a cause of concern. The present investigation was undertaken to examine the effect of inclusion of iron and calcium in the diet at supplementary levels on zinc status of experimental rats. Groups of experimental rats were maintained on diets supplemented with iron (Molar ratio - Zn:Fe 1:30) and calcium (Molar ratio - Zn:Ca 1:667) both individually and in combination for six weeks. Zinc status of these rats was assessed by determining zinc concentration in circulation and in organs, and the activities of zinc containing enzymes in serum and liver. The zinc status of experimental rats receiving supplemental levels of iron and calcium was significantly compromised. Zinc concentration in serum, kidney, spleen and liver was reduced significantly by both these minerals. Six weeks of supplementation of iron and calcium individually, significantly reduced the activity of liver and serum superoxide dismutase and alkaline phosphatase. Activity of liver alcohol dehydrogenase was lowered in calcium supplemented group and in calcium + iron supplemented group, while that of carbonic anhydrase was significantly reduced by iron, calcium and their combination. Supplemental levels of iron and calcium, both individually and in combination, significantly compromised the zinc status of experimental rats. This negative effect of these two minerals was more prominent when these were supplemented for a period of six weeks.

Divergent calcium signaling in RBCs from Tropidurus torquatus (Squamata – Tropiduridae) strengthen classification in lizard evolution

PubMed Central

Beraldo, Flávio H; Garcia, Célia RS

2007-01-01

Background We have previously reported that a Teiid lizard red blood cells (RBCs) such as Ameiva ameiva and Tupinambis merianae controls intracellular calcium levels by displaying multiple mechanisms. In these cells, calcium stores could be discharged not only by: thapsigargin, but also by the Na+/H+ ionophore monensin, K+/H+ ionophore nigericin and the H+ pump inhibitor bafilomycin as well as ionomycin. Moreover, these lizards possess a P2Y-type purinoceptors that mobilize Ca2+ from intracellular stores upon ATP addition. Results Here we report, that RBCs from the tropidurid lizard Tropidurus torquatus store Ca2+ in endoplasmic reticulum (ER) pool but unlike in the referred Teiidae, these cells do not store calcium in monensin-nigericin sensitive pools. Moreover, mitochondria from T. torquatus RBCs accumulate Ca2+. Addition of ATP to a calcium-free medium does not increase the [Ca2+]c levels, however in a calcium medium we observe an increase in cytosolic calcium. This is an indication that purinergic receptors in these cells are P2X-like. Conclusion T. torquatus RBCs present different mechanisms from Teiid lizard red blood cells (RBCs), for controlling its intracellular calcium levels. At T. torquatus the ion is only stored at endoplasmic reticulum and mitochondria. Moreover activation of purinergic receptor, P2X type, was able to induce an influx of calcium from extracelullar medium. These studies contribute to the understanding of the evolution of calcium homeostasis and signaling in nucleated RBCs. PMID:17716375

Divergent calcium signaling in RBCs from Tropidurus torquatus (Squamata--Tropiduridae) strengthen classification in lizard evolution.

PubMed

Beraldo, Flávio H; Garcia, Célia R S

2007-08-23

We have previously reported that a Teiid lizard red blood cells (RBCs) such as Ameiva ameiva and Tupinambis merianae controls intracellular calcium levels by displaying multiple mechanisms. In these cells, calcium stores could be discharged not only by: thapsigargin, but also by the Na+/H+ ionophore monensin, K+/H+ ionophore nigericin and the H+ pump inhibitor bafilomycin as well as ionomycin. Moreover, these lizards possess a P2Y-type purinoceptors that mobilize Ca2+ from intracellular stores upon ATP addition. Here we report, that RBCs from the tropidurid lizard Tropidurus torquatus store Ca2+ in endoplasmic reticulum (ER) pool but unlike in the referred Teiidae, these cells do not store calcium in monensin-nigericin sensitive pools. Moreover, mitochondria from T. torquatus RBCs accumulate Ca2+. Addition of ATP to a calcium-free medium does not increase the [Ca2+]c levels, however in a calcium medium we observe an increase in cytosolic calcium. This is an indication that purinergic receptors in these cells are P2X-like. T. torquatus RBCs present different mechanisms from Teiid lizard red blood cells (RBCs), for controlling its intracellular calcium levels. At T. torquatus the ion is only stored at endoplasmic reticulum and mitochondria. Moreover activation of purinergic receptor, P2X type, was able to induce an influx of calcium from extracellular medium. These studies contribute to the understanding of the evolution of calcium homeostasis and signaling in nucleated RBCs.

Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture*

PubMed Central

Mauceri, Daniela; Hagenston, Anna M.; Schramm, Kathrin; Weiss, Ursula; Bading, Hilmar

2015-01-01

Calcium-binding proteins (CaBPs) such as parvalbumin are part of the cellular calcium buffering system that determines intracellular calcium diffusion and influences the spatiotemporal dynamics of calcium signals. In neurons, CaBPs are primarily localized to the cytosol and function, for example, in nerve terminals in short-term synaptic plasticity. However, CaBPs are also expressed in the cell nucleus, suggesting that they modulate nuclear calcium signals, which are key regulators of neuronal gene expression. Here we show that the calcium buffering capacity of the cell nucleus in mouse hippocampal neurons regulates neuronal architecture by modulating the expression levels of VEGFD and the complement factor C1q-c, two nuclear calcium-regulated genes that control dendrite geometry and spine density, respectively. Increasing the levels of nuclear calcium buffers by means of expression of a nuclearly targeted form of parvalbumin fused to mCherry (PV.NLS-mC) led to a reduction in VEGFD expression and, as a result, to a decrease in total dendritic length and complexity. In contrast, mRNA levels of the synapse pruning factor C1q-c were increased in neurons expressing PV.NLS-mC, causing a reduction in the density and size of dendritic spines. Our results establish a close link between nuclear calcium buffering capacity and the transcription of genes that determine neuronal structure. They suggest that the development of cognitive deficits observed in neurological conditions associated with CaBP deregulation may reflect the loss of necessary structural features of dendrites and spines. PMID:26231212

Protease Activated Receptor-2 Expression and Function in Asthmatic Bronchial Smooth Muscle

PubMed Central

Gilbert, Guillaume; Carvalho, Gabrielle; Trian, Thomas; Ozier, Annaig; Gillibert-Duplantier, Jennifer; Ousova, Olga; Maurat, Elise; Thumerel, Matthieu; Quignard, Jean-François; Girodet, Pierre-Olivier; Marthan, Roger; Berger, Patrick

2014-01-01

Asthmatic bronchial smooth muscle (BSM) is characterized by structural remodeling associated with mast cell infiltration displaying features of chronic degranulation. Mast cell-derived tryptase can activate protease activated receptor type-2 (PAR-2) of BSM cells. The aims of the present study were (i) to evaluate the expression of PAR-2 in both asthmatic and non asthmatic BSM cells and, (ii) to analyze the effect of prolonged stimulation of PAR-2 in asthmatic BSM cells on cell signaling and proliferation. BSM cells were obtained from both 33 control subjects and 22 asthmatic patients. PAR-2 expression was assessed by flow cytometry, western blot and quantitative RT-PCR. Calcium response, transduction pathways and proliferation were evaluated before and following PAR-2 stimulation by SLIGKV-NH2 or trypsin for 1 to 3 days. Asthmatic BSM cells expressed higher basal levels of functional PAR-2 compared to controls in terms of mRNA, protein expression and calcium response. When PAR-2 expression was increased by means of lentivirus in control BSM cells to a level similar to that of asthmatic cells, PAR-2-induced calcium response was then similar in both types of cell. However, repeated PAR-2 stimulations increased the proliferation of asthmatic BSM cells but not that of control BSM cells even following lentiviral over-expression of PAR-2. Such an increased proliferation was related to an increased phosphorylation of ERK in asthmatic BSM cells. In conclusion, we have demonstrated that asthmatic BSM cells express increased baseline levels of functional PAR-2. This higher basal level of PAR-2 accounts for the increased calcium response to PAR-2 stimulation, whereas the increased proliferation to repeated PAR-2 stimulation is related to increased ERK phosphorylation. PMID:24551046

Atorvastatin calcium in combination with methylprednisolone for the treatment of multiple sclerosis relapse.

PubMed

Li, Xiao-ling; Zhang, Zhen-chang; Zhang, Bo; Jiang, Hua; Yu, Chun-mei; Zhang, Wen-jing; Yan, Xiang; Wang, Man-xia

2014-12-01

This study aimed to investigate the efficacy of combined atorvastatin calcium and methylprednisolone for the treatment of multiple sclerosis relapse. Patients with multiple sclerosis (MS) at the relapse phase were randomized to receive either combined treatment of atorvastatin calcium and methylprednisolone (n = 19) or methylprednisolone alone (n = 19). Expanded Disability Status Scale (EDSS) was administered at baseline, 1 week, 2 weeks, 4 weeks, 3 months, and 6 months after treatment initiation. The number and volume of brain lesions were evaluated using magnetic resonance imaging at baseline and 6 months. The levels of IL-13, IL-35, IFN-γ, and IL-10 in the cerebrospinal fluid were examined using the enzyme-linked immunosorbent assay method. There was no significant difference in EDSS scores at 1, 2, and 4 weeks. At 3 and 6 months, the combined treatment group showed significantly lower EDSS scores than the monotherapy group (P < 0.05). The number and volume of brain lesions in the combined treatment group were significantly lower than the monotherapy group at 6 months (P < 0.001). The mean time to relapse was significantly extended in the combined treatment group than the monotherapy group (P < 0.001). At 2 and 4 weeks, the combined treatment group had significantly higher levels of IL-13, IL-35, and IL-10 in the cerebrospinal fluid than the monotherapy group (P < 0.05), but significantly lower level of IFN-γ (P < 0.001). The levels of IL-13 and IL-10 in the combined treatment group were positively correlated with EDSS scores (r = 0.632, P = 0.001; r = 0.731, P = 0.002). Combined treatment with atorvastatin calcium and methylprednisolone can improve the outcomes of MS relapse compared with glucocorticosteroid alone. Copyright © 2014 Elsevier B.V. All rights reserved.

Similar calcium status is present in infants fed formula with and without prebiotics

USDA-ARS?s Scientific Manuscript database

Prebiotic oligosaccharides can increase calcium absorption in adolescents and adults. Whether they affect calcium absorption in infants has not been assessed. Few data are available to compare the calcium status of infants fed modern infant formulas to that of breast fed infants. To evaluate calcium...

Impact of Dietary Calcium Supplement on Circulating Lipoprotein Concentrations and Atherogenic Indices in Overweight and Obese Individuals: A Systematic Review.

PubMed

Heshmati, Javad; Sepidarkish, Mahdi; Namazi, Nazli; Shokri, Fatemeh; Yavari, Mahsa; Fazelian, Siavash; Khorshidi, Masoud; Shidfar, Farzad

2018-03-21

Dyslipidemia is the main risk factor for developing cardiovascular disease. There are discrepancies in the effects of calcium supplementation on modulation of lipid status. Therefore, we aimed to summarize the effects of dietary calcium supplement on circulating lipoprotein concentrations and atherogenic indices in overweight and obese individuals. We conducted a systematic literature search from 2000 until July 2016. PubMed, Scopus, Cochran Library, and ISI Web of Science databases were searched for clinical trials written in English. Placebo controlled clinical trials on calcium or calcium with vitamin D supplement in overweight and obese indiciduals were considered. Finally, 11 clinical trials met the criteria and were included. Most studies (n = 9) evaluated Ca/D co-supplementation. Positive effects of calcium supplementation alone or with vitamin D were as follows: serum levels of total cholesterol (TC; n = 1), triglyceride (TG) concentrations (n = 1), serum levels of low-density lipoprotein cholesterol (LDL-C; n = 5) and high-density lipoprotein cholesterol (HDL-C; n = 3). Seven clinical trials reported atherogenic indices and three of them demonstrated beneficial effects of calcium supplementation on at least one atherogenic index. Calcium supplementation may not be helpful to reduce serum levels of TC and TG in overweight and obese individuals. However, it may modulate LDL-C and HDL-C concentration. More studies are warranted to clarify the effects of calcium supplementation on each atherogenic index.

Intracellular sphingosine releases calcium from lysosomes

PubMed Central

Höglinger, Doris; Haberkant, Per; Aguilera-Romero, Auxiliadora; Riezman, Howard; Porter, Forbes D; Platt, Frances M; Galione, Antony; Schultz, Carsten

2015-01-01

To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in late endosomes and lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC. DOI: http://dx.doi.org/10.7554/eLife.10616.001 PMID:26613410

Effect of heat shock on ultrastructure and calcium distribution in Lavandula pinnata L. glandular trichomes.

PubMed

Huang, S S; Kirchoff, B K; Liao, J P

2013-02-01

The effects of heat shock (HS) on the ultrastructure and calcium distribution of Lavandula pinnata secretory trichomes are examined using transmission electron microscopy and potassium antimonate precipitation. After 48-h HS at 40°C, plastids become distorted and lack stroma and osmiophilic deposits, the cristae of the mitochondria become indistinct, the endoplasmic reticulum acquires a chain-like appearance with ribosomes prominently attached to the lamellae, and the plasma and organelle membranes become distorted. Heat shock is associated with a decrease in calcium precipitates in the trichomes, while the number of precipitates increases in the mesophyll cells. Prolonged exposure to elevated calcium levels may be toxic to the mesophyll cells, while the lack of calcium in the glands cell may deprive them of the normal protective advantages of elevated calcium levels. The inequality in calcium distribution may result not only from uptake from the transpiration stream, but also from redistribution of calcium from the trichomes to the mesophyll cells.

Association between Decreased Serum Parathyroid Hormone after Total Thyroidectomy and Persistent Hypoparathyroidism

PubMed Central

Wang, Jian-Biao; Sun, Hai-Li; Song, Chun-Yi; Gao, Li

2015-01-01

Background Postoperative hypocalcemia caused by hypoparathyroidism is one of the most common morbidities of total thyroidectomy. The aim of this study was to analyze the kinetics and factors affecting PTH levels after total thyroidectomy and central neck dissection (CND). Material/Methods We performed a retrospective study in 438 consecutive patients who underwent total thyroidectomy between January 2007 and December 2010. No patient had a history of thyroid or neck surgery. PTH and calcium levels were recorded 1 day before the operation, during the first 5 days, and during follow-up (2 weeks and 2, 6, and 12 months). Results PTH levels declined to 41.90% of its initial value on the first day after the operation. After surgery, PTH was correlated positively with calcium and inversely with phosphate levels from postoperative day 1 to 14. Based on clinical observation, using a PTH threshold of <7 ng/L on postoperative day 1 was predictive of persistent hypoparathyroidism, with sensitivity and negative predictive value 100%, but poor specificity (70.19%). CND increased the risk of transient hypoparathyroidism compared with total thyroidectomy alone. Patients with thyroiditis had an increased risk of permanent hypoparathyroidism compared with those without thyroiditis. Iatrogenic removal of the parathyroid glands increased the risk of permanent hypoparathyroidism compared with those without iatrogenic parathyroidectomy. Conclusions PTH declined on the first day after thyroidectomy. PTH levels <7 ng/L on the first day after surgery might be associated with persistent hypoparathyroidism. CND, thyroiditis, and iatrogenic parathyroidectomy increased the risk of hypoparathyroidism. PMID:25923249

Effect of a magnesium-based phosphate binder on medial calcification in a rat model of uremia.

PubMed

De Schutter, Tineke M; Behets, Geert J; Geryl, Hilde; Peter, Mirjam E; Steppan, Sonja; Gundlach, Kristina; Passlick-Deetjen, Jutta; D'Haese, Patrick C; Neven, Ellen

2013-06-01

Calcium-based phosphate binders are used to control hyperphosphatemia; however, they promote hypercalcemia and may accelerate aortic calcification. Here we compared the effect of a phosphate binder containing calcium acetate and magnesium carbonate (CaMg) to that of sevelamer carbonate on the development of medial calcification in rats with chronic renal failure induced by an adenine diet for 4 weeks. After 1 week, rats with chronic renal failure were treated with vehicle, 375 or 750 mg/kg CaMg, or 750 mg/kg sevelamer by daily gavage for 5 weeks. Renal function was significantly impaired in all groups. Vehicle-treated rats with chronic renal failure developed severe hyperphosphatemia, but this was controlled in treated groups, particularly by CaMg. Neither CaMg nor sevelamer increased serum calcium ion levels. Induction of chronic renal failure significantly increased serum PTH, dose-dependently prevented by CaMg but not sevelamer. The aortic calcium content was significantly reduced by CaMg but not by sevelamer. The percent calcified area of the aorta was significantly lower than vehicle-treated animals for all three groups. The presence of aortic calcification was associated with increased sox9, bmp-2, and matrix gla protein expression, but this did not differ in the treatment groups. Calcium content in the carotid artery was lower with sevelamer than with CaMg but that in the femoral artery did not differ between groups. Thus, treatment with either CaMg or sevelamer effectively controlled serum phosphate levels in CRF rats and reduced aortic calcification.

Effect of a magnesium-based phosphate binder on medial calcification in a rat model of uremia

PubMed Central

De Schutter, Tineke M; Behets, Geert J; Geryl, Hilde; Peter, Mirjam E; Steppan, Sonja; Gundlach, Kristina; Passlick-Deetjen, Jutta; D'Haese, Patrick C; Neven, Ellen

2013-01-01

Calcium-based phosphate binders are used to control hyperphosphatemia; however, they promote hypercalcemia and may accelerate aortic calcification. Here we compared the effect of a phosphate binder containing calcium acetate and magnesium carbonate (CaMg) to that of sevelamer carbonate on the development of medial calcification in rats with chronic renal failure induced by an adenine diet for 4 weeks. After 1 week, rats with chronic renal failure were treated with vehicle, 375 or 750 mg/kg CaMg, or 750 mg/kg sevelamer by daily gavage for 5 weeks. Renal function was significantly impaired in all groups. Vehicle-treated rats with chronic renal failure developed severe hyperphosphatemia, but this was controlled in treated groups, particularly by CaMg. Neither CaMg nor sevelamer increased serum calcium ion levels. Induction of chronic renal failure significantly increased serum PTH, dose-dependently prevented by CaMg but not sevelamer. The aortic calcium content was significantly reduced by CaMg but not by sevelamer. The percent calcified area of the aorta was significantly lower than vehicle-treated animals for all three groups. The presence of aortic calcification was associated with increased sox9, bmp-2, and matrix gla protein expression, but this did not differ in the treatment groups. Calcium content in the carotid artery was lower with sevelamer than with CaMg but that in the femoral artery did not differ between groups. Thus, treatment with either CaMg or sevelamer effectively controlled serum phosphate levels in CRF rats and reduced aortic calcification. PMID:23486515

Effectiveness of a Theory-Driven Nutritional Education Program in Improving Calcium Intake among Older Mauritian Adults

PubMed Central

Jeewon, Rajesh

2013-01-01

Background. Low calcium intake, a risk factor of osteoporosis and subsequent fractures, has been previously reported among post-menopausal women in Mauritius. Objective. To assess the effectiveness of a theory-based educational intervention in improving the calcium intake, self-efficacy, and knowledge of older Mauritians. Methodology. The study was conducted as a pre- and post-test design which was evaluated through a baseline, immediate postintervention, and 2-month follow-up assessments. Participants were adults (n = 189) aged ≥40 years old from 2 urban community-based centres. The intervention group (IG) (n = 98) participated in 6 weekly interactive lessons based on the health belief model (HBM). The main outcome measures were calcium intake, HB scale scores, knowledge scores, and physical activity level (PAL). Anthropometric measurements were also assessed. Results. The IG significantly increased its baseline calcium intake, knowledge and self-efficacy (P < 0.001) at post-assessments. A significant decrease in waist circumference in the IG was noted (P < 0.05) after intervention. PAL significantly increased by 12.3% at post-test and by 29.6% at follow-up among intervention adults when compared to the CG (P < 0.001). Conclusion. A theory-driven educational intervention is effective in improving the dietary calcium intake, knowledge, self-efficacy, and PAL of older community-based Mauritian adults. PMID:24453901

Postoperative Calcium Management in Same-Day Discharge Thyroid and Parathyroid Surgery.

PubMed

Nelson, Kurt L; Hinson, Andrew M; Lawson, Bradley R; Middleton, Derek; Bodenner, Donald L; Stack, Brendan C

2016-05-01

To describe a safe and effective postoperative prophylactic calcium regimen for same-day discharge thyroid and parathyroid surgery. Case series with chart review. Tertiary referral academic institution. In total, 162 adult patients who underwent total thyroidectomy, completion thyroidectomy, unilateral parathyroidectomy, parathyroidectomy with bilateral neck exploration, or revision parathyroidectomy were identified preoperatively to be candidates for same-day discharge. All patients in this study were successfully discharged the same day on our standard prophylactic calcium regimen. Less than 1% (1/162) of patients re-presented to the hospital within 30 days of surgery, and that patient was successfully discharged from the emergency department after negative workup for hypocalcemia. There was no significant difference between preoperative and postoperative calcium levels in the total/completion thyroidectomy groups (9.3 vs 9.2 mg/dL, respectively; P = .14). The average postoperative calcium level in the parathyroid group was well within normal limits (9.5 mg/dL), and the difference in postoperative calcium levels between revision and primary parathyroidectomy cases was not significantly different (P = .34). The reported calcium regimen demonstrates a safe, effective, and objective means of postoperative calcium management in outpatient thyroid and parathyroid surgery in appropriately selected patients. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Extracellular calcium antagonizes forskolin-induced aquaporin 2 trafficking in collecting duct cells.

PubMed

Procino, Giuseppe; Carmosino, Monica; Tamma, Grazia; Gouraud, Sabine; Laera, Antonia; Riccardi, Daniela; Svelto, Maria; Valenti, Giovanna

2004-12-01

Urinary concentrating defects and polyuria are the most important renal manifestations of hypercalcemia and the resulting hypercalciuria. In this study, we tested the hypothesis that hypercalciuria-associated polyuria in kidney collecting duct occurs through an impairment of the vasopressin-dependent aquaporin 2 (AQP2) water channel targeting to the apical membrane possibly involving calcium-sensing receptor (CaR) signaling. AQP2-transfected collecting duct CD8 cells were used as experimental model. Quantitation of cell surface AQP2 immunoreactivity was performed using an antibody recognizing the extracellular AQP2 C loop. Intracellular cyclic adenosine monophosphate (cAMP) accumulation was measured in CD8 cells using a cAMP enzyme immunoassay kit. To study the translocation of protein kinase C (PKC), membranes or cytosol fractions from CD8 cells were subjected to Western blotting using anti-PKC isozymes antibodies. The amount of F-actin was determined by spectrofluorometric techniques. Intracellular calcium measurements were performed by spectrofluorometric analysis with Fura-2/AM. We demonstrated that extracellular calcium (Ca2+ o) (5 mmol/L) strongly inhibited forskolin-stimulated increase in AQP2 expression in the apical plasma membrane. At least three intracellular pathways activated by extracellular calcium were found to contribute to this effect. Firstly, the increase in cAMP levels in response to forskolin stimulation was drastically reduced in cells pretreated with Ca2+ o compared to untreated cells. Second, Ca2+ o activated PKC, known to counteract vasopressin response. Third, quantification of F-actin demonstrated that Ca2+ o caused a nearly twofold increase in F-actin content compared with basal conditions. All these effects were mimicked by a nonmembrane permeable agonist of the extracellular CaR, Gd3+. Together, these data demonstrate that extracellular calcium, possibly acting through the endogenous CaR, antagonizes forskolin-induced AQP2 translocation to the apical plasma membrane in CD8 cells. In hypercalciuria, this mechanism might blunt water reabsorption and prevent further calcium concentration, thus protecting against a potential risk of urinary calcium-containing stone formation.

Calcium and magnesium in drinking-water and risk of death from lung cancer in women.

PubMed

Cheng, Meng-Hsuan; Chiu, Hui-Fen; Tsai, Shang-Shyue; Chen, Chih-Cheng; Yang, Chun-Yuh

2012-01-01

The possible association between the risk of lung cancer in women and the levels of calcium (Ca) and magnesium (Mg) in drinking-water from municipal supplies was investigated in a matched, case-control study in Taiwan. All eligible female lung cancer deaths (3,532 cases) of Taiwan residents, from 2000 through to 2008, were compared with deaths from other causes (3,532 controls), and the levels of Ca and Mg in drinking-water of these residents were determined. Data on Ca and Mg levels in drinking-water throughout Taiwan were obtained from the Taiwan Water Supply Corporation (TWSC). The control group consisted of people who died from other causes, and the controls were pair-matched to the cases by sex, year of birth, and year of death. The adjusted odd ratios were not statistically significant for the relationship between Ca levels in drinking-water and lung cancer in women. The adjusted odd ratios for female lung cancer deaths for those with higher Mg levels in their drinking-water, as compared to the lowest tertile, were 0.82 (95% CI = 0.72-0.93) and 0.80 (95% CI = 0.69-0.93), respectively. The results of the present study show that there is a significant trend toward a decreased risk of lung cancer in women with increasing Mg levels in drinking-water.

Nerve Growth Factor Sensitizes Adult Sympathetic Neurons to the Proinflammatory Peptide Bradykinin

PubMed Central

Vivas, Oscar; Kruse, Martin

2014-01-01

Levels of nerve growth factor (NGF) are elevated in inflamed tissues. In sensory neurons, increases in NGF augment neuronal sensitivity (sensitization) to noxious stimuli. Here, we hypothesized that NGF also sensitizes sympathetic neurons to proinflammatory stimuli. We cultured superior cervical ganglion (SCG) neurons from adult male Sprague Dawley rats with or without added NGF and compared their responsiveness to bradykinin, a proinflammatory peptide. The NGF-cultured neurons exhibited significant depolarization, bursts of action potentials, and Ca2+ elevations after bradykinin application, whereas neurons cultured without NGF showed only slight changes in membrane potential and cytoplasmic Ca2+ levels. The NGF effect, which requires trkA receptors, takes hours to develop and days to reverse. We addressed the ionic mechanisms underlying this sensitization. NGF did not alter bradykinin-induced M-current inhibition or phosphatidylinositol 4,5-bisphosphate hydrolysis. Maxi-K channel-mediated current evoked by depolarizations was reduced by 50% by culturing neurons in NGF. Application of iberiotoxin or paxilline, blockers of Maxi-K channels, mimicked NGF treatment and sensitized neurons to bradykinin application. A calcium channel blocker also mimicked NGF treatment. We found that NGF reduces Maxi-K channel opening by decreasing the activity of nifedipine-sensitive calcium channels. In conclusion, culture in NGF reduces the activity of L-type calcium channels, and secondarily, the calcium-sensitive activity of Maxi-K channels, rendering sympathetic neurons electrically hyper-responsive to bradykinin. PMID:25186743

Effects of dietary calcium, phosphorus and magnesium on intranephronic calculosis in rats.

PubMed

Woodward, J C; Jee, W S

1984-12-01

The effects of varying dietary levels of calcium, phosphorus and magnesium on the incidence and severity of intranephronic calculosis were studied. Renal calculi were induced by feeding female rats the AIN-76TM semipurified diet for 4 weeks. During this time period, dietary levels of 350, 450 or 550 mg calcium per 100 g diet did not influence the occurrence of urolithiasis. Increasing dietary magnesium levels from 50 to 350 mg was beneficial in preventing the occurrence of calculi if the diet contained 400 mg or less phosphorus. The protective effects of dietary magnesium were counteracted when dietary phosphorus levels were increased from 400 mg to 550 or 700 mg. If the dietary content of phosphorus and magnesium permitted the formation of renal calculi, the severity of the condition was also influenced by the dietary level of calcium. Some animal groups fed semipurified diets did not have microscopic or radiographic evidence of renal calculi but were found to have significantly elevated renal calcium values. It was suggested that these animals might be in a precalculus-forming state.

Parathyroid Hormone Injection

MedlinePlus

... injection is used along with calcium and vitamin D to treat low levels of calcium in the ... condition can be controlled by calcium and vitamin D alone. Parathyroid hormone injection is in a class ...

T Cell Dynamic Activation and Functional Analysis in Nanoliter Droplet Microarray.

PubMed

Sarkar, Saheli; Motwani, Vinny; Sabhachandani, Pooja; Cohen, Noa; Konry, Tania

2015-06-01

Characterization of the heterogeneity in immune reactions requires assessing dynamic single cell responses as well as interactions between the various immune cell subsets. Maturation and activation of effector cells is regulated by cell contact-dependent and soluble factor-mediated paracrine signalling. Currently there are few methods available that allow dynamic investigation of both processes simultaneously without physically constraining non-adherent cells and eliminating crosstalk from neighboring cell pairs. We describe here a microfluidic droplet microarray platform that permits rapid functional analysis of single cell responses and co-encapsulation of heterotypic cell pairs, thereby allowing us to evaluate the dynamic activation state of primary T cells. The microfluidic droplet platform enables generation and docking of monodisperse nanoliter volume (0.523 nl) droplets, with the capacity of monitoring a thousand droplets per experiment. Single human T cells were encapsulated in droplets and stimulated on-chip with the calcium ionophore ionomycin. T cells were also co-encapsulated with dendritic cells activated by ovalbumin peptide, followed by dynamic calcium signal monitoring. Ionomycin-stimulated cells depicted fluctuation in calcium signalling compared to control. Both cell populations demonstrated marked heterogeneity in responses. Calcium signalling was observed in T cells immediately following contact with DCs, suggesting an early activation signal. T cells further showed non-contact mediated increase in calcium level, although this response was delayed compared to contact-mediated signals. Our results suggest that this nanoliter droplet array-based microfluidic platform is a promising technique for assessment of heterogeneity in various types of cellular responses, detection of early/delayed signalling events and live cell phenotyping of immune cells.

Flow rate, pH and calcium concentration of saliva of children and adolescents with type 1 diabetes mellitus.

PubMed

Moreira, A R; Passos, I A; Sampaio, F C; Soares, M S M; Oliveira, R J

2009-08-01

Alterations in salivary parameters may increase the caries risk in diabetic children, but, contradictory data on this issue have been reported. The aims of this study were to compare salivary parameters (flow rate, pH and calcium concentration) between healthy and type 1 diabetes mellitus (T1DM) individuals. The sample consisted of 7- to 18-year-old individuals divided into two groups: 30 subjects with T1DM (group A) and 30 healthy control subjects (group B). Fasting glucose levels were determined. Unstimulated and stimulated saliva was collected. The pH of unstimulated saliva was measured with paper strips and an electrode. Calcium concentrations in stimulated saliva were determined with a selective electrode. Group A individuals had inadequate blood glucose control (HbA(1C) >9%), with means +/- SD unstimulated salivary flow rate of 0.15 +/- 0.1 mL/min compared to 0.36 +/- 0.2 mL/min for group B (P < 0.01). Stimulated salivary flow rate was similar by both groups and above 2.0 mL/min. Saliva pH was 6.0 +/- 0.8 for group A and significantly different from 7.0 +/- 0.6 for group B (P < 0.01). Salivary calcium was 14.7 +/- 8.1 mg/L for group A and significantly higher than 9.9 +/- 6.4 mg/L for group B (P < 0.01). Except for elevated calcium concentrations in saliva, salivary parameters favoring caries such as low saliva pH and unstimulated salivary flow rate were observed in T1DM individuals.

Correlation between calcium and phosphate levels to calculus accumulation on coronary heart disease patients

NASA Astrophysics Data System (ADS)

Cahaya, Cindy; Masulili, Sri Lelyati C.; Lessang, Robert; Radi, Basuni

2017-02-01

Coronary Artery Disease (CAD) or Coronary Heart Disease (CHD) is a disease that happened because of blood flow being blocked by atherosclerosis. Atherosclerosis is a process of hardening of the arteries which characterized by thickening and loss of elasticity of the intimal layer of vascular wall, by lipid deposit. Periodontitis is a chronic multifactorial inflammatory disease caused by microorganism and characterized by progressive destruction of the tooth supporting apparatus leading to tooth loss. Many studies use saliva as a valuable source for clinically information, as an asset for early diagnosis, prognostic and reviewer for pascatherapy status. Dental calculus had happened as a consequence of saliva supersaturation by calcium and phosphate. Salivary flow rate and its composition influence the formation of calculus. Increasing salivary calcium levels is characteristic of periodontitis patients. An important hipotesis in Cardiology is chronic infections contribute in atherosclerosis. Objective: To analyse the correlation between calcium and phosphate levels in saliva to calculus accumulation on CHD patients. Result: Correlation analysis between salivary calcium levels with calculus accumulation in patients with CHD and non-CHD showed no significant p value, p=0.59 and p=0.518. Correlation analysis between salivary phosphate levels and calculus accumulation showed no significant p value, p=0.836 for CHD patients and p=0.484 for non-CHD patients. Conclusion: There are no correlation between calcium levels and phosphate levels with calculus accumulation in CHD patients. Further research need to be done.

Java project on periodontal diseases: effect of vitamin C/calcium threonate/citrus flavonoids supplementation on periodontal pathogens, CRP and HbA1c.

PubMed

Amaliya, Amaliya; Laine, Marja L; Loos, Bruno G; Van der Velden, Ubele

2015-12-01

To assess in a periodontally diseased rural population deprived from regular dental care and having poor dietary conditions, the effect of vitamin C/calcium threonate/citrus flavonoids (VitC/Ca/Fl) supplementation on subgingival microbiota and plasma levels of vitamin C, HbA1c and hsCRP. The study population consisted of 98 subjects who previously participated in a prospective study on the natural history of periodontitis. Participants were instructed to consume one tablet/day containing 200 mg Ester C(®) calcium ascorbate, 25 mg calcium threonate and 100 mg citrus flavonoids for 90 days. Following parameters were evaluated: prevalence/amount of seven traditional periodontal pathogens, cytomegalovirus, Epstein-Barr virus (EBV); and plasma levels of vitamin C, HbA1c and hsCRP. After VitC/Ca/Fl supplementation, 100% of subjects showed normal plasma vitamin C values compared to 55% before. At baseline, 48% of subjects harboured Aggregatibacter actinomycetemcomitans, >97% the other periodontal pathogens and 73% EBV. Supplementation with VitC/Ca/F reduced the subgingival load of all studied bacteria (p-values: 0.014-0.0001) and EBV (p < 0.0001) substantially in all initially positive subjects. Plasma levels of HbA1c and hsCRP dropped in all subjects (p < 0.0001). This uncontrolled study suggested that supplemental VitC/Ca/Fl may be helpful in reducing subgingival numbers of periodontal pathogens and EBV, and promoting systemic health. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Defective Store-Operated Calcium Entry Causes Partial Nephrogenic Diabetes Insipidus.

PubMed

Mamenko, Mykola; Dhande, Isha; Tomilin, Viktor; Zaika, Oleg; Boukelmoune, Nabila; Zhu, Yaming; Gonzalez-Garay, Manuel L; Pochynyuk, Oleh; Doris, Peter A

2016-07-01

Store-operated calcium entry (SOCE) is the mechanism by which extracellular signals elicit prolonged intracellular calcium elevation to drive changes in fundamental cellular processes. Here, we investigated the role of SOCE in the regulation of renal water reabsorption, using the inbred rat strain SHR-A3 as an animal model with disrupted SOCE. We found that SHR-A3, but not SHR-B2, have a novel truncating mutation in the gene encoding stromal interaction molecule 1 (STIM1), the endoplasmic reticulum calcium (Ca(2+)) sensor that triggers SOCE. Balance studies revealed increased urine volume, hypertonic plasma, polydipsia, and impaired urinary concentrating ability accompanied by elevated circulating arginine vasopressin (AVP) levels in SHR-A3 compared with SHR-B2. Isolated, split-open collecting ducts (CD) from SHR-A3 displayed decreased basal intracellular Ca(2+) levels and a major defect in SOCE. Consequently, AVP failed to induce the sustained intracellular Ca(2+) mobilization that requires SOCE in CD cells from SHR-A3. This effect decreased the abundance of aquaporin 2 and enhanced its intracellular retention, suggesting impaired sensitivity of the CD to AVP in SHR-A3. Stim1 knockdown in cultured mpkCCDc14 cells reduced SOCE and basal intracellular Ca(2+) levels and prevented AVP-induced translocation of aquaporin 2, further suggesting the effects in SHR-A3 result from the expression of truncated STIM1. Overall, these results identify a novel mechanism of nephrogenic diabetes insipidus and uncover a role of SOCE in renal water handling. Copyright © 2016 by the American Society of Nephrology.

Maternal hypervitaminosis D reduces fetal bone mass and mineral acquisition and leads to neonatal lethality.

PubMed

Lieben, L; Stockmans, I; Moermans, K; Carmeliet, G

2013-11-01

Pregnancy challenges maternal calcium handling because sufficient calcium has to be transferred to the fetus to ensure fetal bone mass acquisition. 1,25(OH)2 vitamin D [1,25(OH)2D] is an important regulator of calcium homeostasis during adulthood, yet its role seems redundant for the maternal adaptations to pregnancy as well as during fetal development. However, not only deficiency but also excess of 1,25(OH)2D can be harmful and we therefore questioned whether high maternal 1,25(OH)2D levels may injure fetal development or neonatal outcome, as maternal-fetal transport of 1,25(OH)2D has been largely disputed. To this end, vitamin D receptor (VDR) null (Vdr(-/-)) females, displaying high 1,25(OH)2D levels, were mated with Vdr(+/-) males to obtain pregnancies with fetuses that are responsive (Vdr(+/-)) or resistant (Vdr(-/-)) to 1,25(OH)2D. Surprisingly, most of the Vdr(+/-) neonates died shortly after birth, whereas none of the Vdr(-/-). Mechanistically, we noticed that in Vdr(+/-) embryos, serum calcium levels were normal, but that skeletal calcium storage was reduced as evidenced by decreased mineralized bone mass as well as bone mineral content. More precisely, bone formation was decreased and the level of bone mineralization inhibitors was increased. This decreased fetal skeletal calcium storage may severely compromise calcium balance and survival at birth. In conclusion, these data indicate that high maternal 1,25(OH)2D levels are transferred across the placental barrier and adversely affect the total amount of calcium stored in fetal bones which is accompanied by neonatal death. © 2013 Elsevier Inc. All rights reserved.

Mitochondrial impairment increases FL-PINK1 levels by calcium-dependent gene expression☆

PubMed Central

Gómez-Sánchez, Rubén; Gegg, Matthew E.; Bravo-San Pedro, José M.; Niso-Santano, Mireia; Alvarez-Erviti, Lydia; Pizarro-Estrella, Elisa; Gutiérrez-Martín, Yolanda; Alvarez-Barrientos, Alberto; Fuentes, José M.; González-Polo, Rosa Ana; Schapira, Anthony H.V.

2014-01-01

Mutations of the PTEN-induced kinase 1 (PINK1) gene are a cause of autosomal recessive Parkinson's disease (PD). This gene encodes a mitochondrial serine/threonine kinase, which is partly localized to mitochondria, and has been shown to play a role in protecting neuronal cells from oxidative stress and cell death, perhaps related to its role in mitochondrial dynamics and mitophagy. In this study, we report that increased mitochondrial PINK1 levels observed in human neuroblastoma SH-SY5Y cells after carbonyl cyanide m-chlorophelyhydrazone (CCCP) treatment were due to de novo protein synthesis, and not just increased stabilization of full length PINK1 (FL-PINK1). PINK1 mRNA levels were significantly increased by 4-fold after 24 h. FL-PINK1 protein levels at this time point were significantly higher than vehicle-treated, or cells treated with CCCP for 3 h, despite mitochondrial content being decreased by 29%. We have also shown that CCCP dissipated the mitochondrial membrane potential (Δψm) and induced entry of extracellular calcium through L/N-type calcium channels. The calcium chelating agent BAPTA-AM impaired the CCCP-induced PINK1 mRNA and protein expression. Furthermore, CCCP treatment activated the transcription factor c-Fos in a calcium-dependent manner. These data indicate that PINK1 expression is significantly increased upon CCCP-induced mitophagy in a calcium-dependent manner. This increase in expression continues after peak Parkin mitochondrial translocation, suggesting a role for PINK1 in mitophagy that is downstream of ubiquitination of mitochondrial substrates. This sensitivity to intracellular calcium levels supports the hypothesis that PINK1 may also play a role in cellular calcium homeostasis and neuroprotection. PMID:24184327

[Impact of drinking water calcium and magnesium levels on morbidity in the Omsk Region].

PubMed

Erofeev, Iu V; Neskin, T A; Turchaninov, D V

2006-01-01

Drinking water calcium and magnesium levels were examined for impact on morbidity in a model rural area of a West Siberian region. It was ascertained that there were negative correlations between the water levels of the above elements and the incidence of respiratory, gastrointestinal, and locomotor diseases and positive correlations between the concentrations of calcium and magnesium and the incidence of nervous, urogenital, and eye diseases. It is concluded that by adjusting the findings, the medical care availability factor should be taken into account in the investigations using the health indices calculated on the data from official medical accounts. This investigation has shown the estimation of the drinking water levels of calcium and magnesium as a significant hygienic problem for a model region.

Parathyroid Hormone Levels and Cognition

NASA Technical Reports Server (NTRS)

Burnett, J.; Smith, S.M.; Aung, K.; Dyer, C.

2009-01-01

Hyperparathyroidism is a well-recognized cause of impaired cognition due to hypercalcemia. However, recent studies have suggested that perhaps parathyroid hormone itself plays a role in cognition, especially executive dysfunction. The purpose of this study was to explore the relationship of parathyroid hormone levels in a study cohort of elders with impaied cognition. Methods: Sixty community-living adults, 65 years of age and older, reported to Adult Protective Services for self-neglect and 55 controls matched (on age, ethnicity, gender and socio-economic status) consented and participated in this study. The research team conducted in-home comprehensive geriatric assessments which included the Mini-mental state exam (MMSE), the 15-item geriatric depression scale (GDS) , the Wolf-Klein clock test and a comprehensive nutritional panel, which included parathyroid hormone and ionized calcium. Students t tests and linear regression analyses were performed to assess for bivariate associations. Results: Self-neglecters (M = 73.73, sd=48.4) had significantly higher PTH levels compared to controls (M =47.59, sd=28.7; t=3.59, df=98.94, p<.01). There was no significant group difference in ionized calcium levels. Overall, PTH was correlated with the MMSE (r=-.323, p=.001). Individual regression analyses revealed a statistically significant correlation between PTH and MMSE in the self-neglect group (r=-.298, p=.024) and this remained significant after controlling for ionized calcium levels in the regression. No significant associations were revealed in the control group or among any of the other cognitive measures. Conclusion: Parathyroid hormone may be associated with cognitive performance.

CALCIPROTEIN PARTICLE FORMATION IN PERITONEAL DIALYSIS EFFLUENT IS DEPENDENT ON DIALYSATE CALCIUM CONCENTRATION.

PubMed

Cai, Michael M; Smith, Edward R; Kent, Annette; Huang, Louis; Hewitson, Tim D; McMahon, Lawrence P; Holt, Stephen G

2018-05-23

The accumulation of fetuin-A-containing calciprotein particles (CPP) in the serum of patients with renal disease and those with chronic inflammation may be involved in driving sterile inflammation and extraosseous mineral deposition. We previously showed that both fetuin-A and CPP were present in the peritoneal dialysis (PD) effluent of stable PD patients. It is unknown whether different PD fluids might affect the formation of CPP in vivo Method: Peritoneal effluent from 12 patients was collected after a 6-hour dwell with 7 different commercial PD fluids. Calciprotein particles and inflammatory cytokines were measured by flow cytometry. High inter-subject variability in CPP concentration was observed. Peritoneal dialysis fluids containing 1.75 mmol/L calcium were associated with enhanced formation of CPP in vivo , compared with fluids containing 1.25 mmol/L calcium. Osmotic agent, fluid pH, and glucose concentration did not affect CPP formation. Peritoneal dialysis effluent CPP levels were not associated with changes in inflammatory cytokines. High calcium-containing PD fluids favor intraperitoneal CPP formation. This finding may have relevance for future PD fluid design.

Disorder of endoplasmic reticulum calcium channel components is associated with the increased apoptotic potential in pale, soft, exudative pork.

PubMed

Guo, Bing; Zhang, Wangang; Tume, Ron K; Hudson, Nicholas J; Huang, Feng; Yin, Yan; Zhou, Guanghong

2016-05-01

Eight pale, soft and exudative (PSE) and eight reddish-pink, firm and non-exudative (RFN) porcine longissimus muscle samples were selected based on pH and L* at 1h postmortem (PM), and drip loss at 24h PM, and used to evaluate the cellular calcium and apoptosis status. We found that SERCA1 was decreased, while IP3R was decreased in PSE meat (P<0.05), indicative of the overloaded sarcoplasmic calcium status. In PSE meat, the pro-apoptotic factor BAX was increased while the anti-apoptotic factor Bcl-2 was decreased (P<0.05). The significantly increased activity of caspase 3 and the expression of its cleavage fragment suggested higher apoptotic potential in PSE meat compared with RFN meat (P<0.05). Moreover, the significantly higher expression level of cytochrome C (P<0.05) suggests the important role of mitochondria during apoptosis appearance in PSE meat. Taken together, our data inferred that the calcium channel disorder present in PSE meat was associated with the increased apoptotic potential. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurement of urinary calcium using AT89C51RD2 microcontroller.

PubMed

Neelamegam, P; Jamaludeen, A; Rajendran, A; Raghunathan, R

2009-04-01

A simple and inexpensive absorption technique for determination of calcium ion in urine samples is developed, comprising a light emitting diode (650 nm) as the light source and photodiode as the detector with AT89C51RD2 microcontroller. The design of the system and details of interface, calibration, and procedure of operation are explained in this paper. Software is developed to monitor sample processing and to display the results in liquid crystal display screen. With 15 microl sample volume, a linear output is obtained in the range of 2.5-7.5 mM calcium with a detection limit of 0.06 mM. Interferences from other cations such as monovalent ion and divalent ion are investigated in the expected range, which are normally present in clinical samples, and absorption changes over the pH range of 3-12 are also determined. This system has been demonstrated successfully for the successive assay of calcium in urine samples, with the results comparing well to those achieved and in good agreement with values obtained with the current clinical spectrophotometric method at 95% of confidence level.

Calcium - ionized

MedlinePlus

... diuretics Thrombocytosis (high platelet count) Tumors Vitamin A excess Vitamin D excess Lower-than-normal levels may be due to: Hypoparathyroidism Malabsorption Osteomalacia Pancreatitis Renal failure Rickets Vitamin D deficiency Alternative Names Free calcium; Ionized calcium ...

Effect of calcium and vitamin D on growth, rickets and Kashin-Beck disease in 0- to 5-year-old children in a rural area of central Tibet.

PubMed

Rooze, Shancy; Mathieu, Françoise; Claus, William; Yangzom, Tashi; Yangzom, Dikki; Goyens, Philippe; de Maertelaer, Viviane

2016-06-01

To evaluate the effect of calcium (15 mmol/day) and vitamin D (625 μg/month), as single supplement or in combination, vs. no supplement on growth, clinical signs of rickets and Kashin-Beck disease (KBD) and dental health. Prospective controlled trial involving children aged 0-5 years living in four groups of villages in a KBD-endemic rural area of central Tibet who received either calcium and/or vitamin D or no supplement. The cohort was followed over 3 years. Primary outcome was the impact of the different supplementation regimes on KBD, rickets and growth; secondary outcomes were impact on urinary levels of calcium and phosphorus, biomarkers of bone and cartilage turnover, and dental health. No difference was observed between the four groups with regard to anthropometric data, rickets, KBD, urinary levels of CrossLaps(®) and CartiLaps(®) . Weight for height or age, mid-upper arm circumference and skinfold thickness decreased in the four groups. Height for age increased and the prevalence of KBD fell in the four groups. Dental health was better in the group receiving calcium and vitamin D. Urinary calcium levels increased after 3 years of follow-up in all groups; the group receiving vitamin D had a higher increase (P-value: 0.044). The same global increase was observed for urinary phosphorus levels; the group receiving calcium had a higher increase (P-value: 0.01). Calcium and vitamin D failed to improve growth and bone metabolism of children living in a KBD-endemic rural area. Calcium and vitamin D supplementation improved dental health. © 2016 John Wiley & Sons Ltd.

Calcium and vitamin D intake and biochemical tests in short-stature children and adolescents.

PubMed

Bueno, A L; Czepielewski, M A; Raimundo, F V

2010-11-01

Growth is highly dependent on the absorption of nutrients. Inadequate calcium and vitamin D intake may compromise bone mineralization and growth. There is a great deal of concern regarding calcium and vitamin D intake, as well as biochemical changes in children and adolescents, which led us to investigate calcium and vitamin D levels during growth. Fifty-eight children and adolescents with short stature (z-score <3 s.d.) were evaluated from September 2005 to February 2007. Blood biochemical analyses and 24-h urine tests were performed and were used to evaluate calcium, phosphorus, creatinine, sodium, alkaline phosphatase, parathyroid hormone (PTH) and 25(OH)D levels. Dietary inquiries, repeated three times, were used to estimate the actual intake of these substances. A reduced calcium (608.6 mg/day) and vitamin D (72.5 IU/day) intake was observed. Calcium excretion in 24-h urine (56 mg/24 h) and calcium excretion by weight (2.0 mg/24 h/kg) showed scores that were below normal. A negative correlation between PTH and both dietary vitamin D (r=-0.46; P<0.01) and calcium intake (r =-0.41; P<0.001) was observed. The low calcium and vitamin D intake observed in short-stature children and adolescents was associated with biochemical results, and suggested that PTH and calcium excretion may be useful screening tests for evaluating dietary calcium and vitamin D.

Formation and reduction of furan in a soy sauce model system.

PubMed

Kim, Min Yeop; Her, Jae-Young; Kim, Mina K; Lee, Kwang-Geun

2015-12-15

The formation and reduction of furan using a soy sauce model system were investigated in the present study. The concentration of furan fermented up to 30 days increased by 211% after sterilization compared to without sterilization. Regarding fermentation temperature, furan level after 30 days' fermentation was the highest at 30°C (86.21 ng/mL). The furan levels in the soy sauce fermentation at 20°C and 40°C were reduced by 45% and 88%, respectively compared to 30°C fermentation. Five metal ions (iron sulfate, zinc sulfate, manganese sulfate, magnesium sulfate, and calcium sulfate), sodium sulfite, ascorbic acid, dibutyl hydroxyl toluene (BHT), and butylated hydroxyanisole (BHA) were added in a soy sauce model system. The addition of metal ions such as magnesium sulfate and calcium sulfate reduced the furan concentration significantly by 36-90% and 27-91%, respectively in comparison to furan level in the control sample (p<0.05). Iron sulfate and ascorbic acid increased the furan level at 30 days' fermentation in the soy sauce model system by 278% and 87%, respectively. In the case of the BHT and BHA, furan formation generally was reduced in the soy sauce model system by 84%, 56%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessment of bone turnover markers and bone mineral density in normal short boys.

PubMed

Gayretli Aydin, Zeynep Gökçe; Bideci, Aysun; Emeksiz, Hamdi C; Çelik, Nurullah; Döğer, Esra; Bukan, Neslihan; Yildiz, Ummügülsüm; Camurdan, Orhun M; Cinaz, Peyami

2015-11-01

To investigate whether there is a change in bone turnover-related biochemical markers and bone mineral density of children with constitutional delay of growth and puberty (CDGP) in the prepubertal period. We measured serum calcium, phosphorus, alkaline phosphatase, parathormone, 25-OH vitamin D, osteocalcin, osteoprotogerin and urinary deoxypyridinoline levels (D-pyd), and bone mineral density (BMD) in 31 prepubertal boys with CDGP. These children were compared with 22 prepubertal boys with familial short stature (FSS) and 27 normal prepubertal boys. Urinary D-pyd was significantly high in CDGP group as compared to control group (p=0.010). Volumetric BMD did not significantly differ between CDGP, FSS, and control groups (p=0.450). Volumetric BMD and urinary D-pyd levels of FSS and control groups were similar. Mean or median levels of calcium, phosphorus, alkaline phosphatase, parathormone, and osteoprotegerin did not significantly differ between CDGP, FSS, and control groups. Our data suggest that prepubertal boys with CDPG have normal bone turnover. However, their significantly higher urinary D-pyd levels relative to those of FSS and control groups might be an indicator of later development of osteoporosis. Therefore, long-term follow-up studies monitoring bone mineral status of prepubertal boys with CDPG from prepuberty to adulthood are needed to better understand bone metabolism of these patients.

Compromised zinc status of experimental rats as a consequence of prolonged iron & calcium supplementation

PubMed Central

Jayalakshmi, S.; Platel, Kalpana

2016-01-01

Background & objectives: Iron supplementation is usually given to pregnant and lactating women who may also have marginal deficiency of zinc. The negative impact of supplemental iron and calcium on zinc status is a cause of concern. The present investigation was undertaken to examine the effect of inclusion of iron and calcium in the diet at supplementary levels on zinc status of experimental rats. Methods: Groups of experimental rats were maintained on diets supplemented with iron (Molar ratio - Zn:Fe 1:30) and calcium (Molar ratio - Zn:Ca 1:667) both individually and in combination for six weeks. Zinc status of these rats was assessed by determining zinc concentration in circulation and in organs, and the activities of zinc containing enzymes in serum and liver. Results: The zinc status of experimental rats receiving supplemental levels of iron and calcium was significantly compromised. Zinc concentration in serum, kidney, spleen and liver was reduced significantly by both these minerals. Six weeks of supplementation of iron and calcium individually, significantly reduced the activity of liver and serum superoxide dismutase and alkaline phosphatase. Activity of liver alcohol dehydrogenase was lowered in calcium supplemented group and in calcium + iron supplemented group, while that of carbonic anhydrase was significantly reduced by iron, calcium and their combination. Interpretation & conclusions: Supplemental levels of iron and calcium, both individually and in combination, significantly compromised the zinc status of experimental rats. This negative effect of these two minerals was more prominent when these were supplemented for a period of six weeks. PMID:27121523

Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture.

PubMed

Mauceri, Daniela; Hagenston, Anna M; Schramm, Kathrin; Weiss, Ursula; Bading, Hilmar

2015-09-18

Calcium-binding proteins (CaBPs) such as parvalbumin are part of the cellular calcium buffering system that determines intracellular calcium diffusion and influences the spatiotemporal dynamics of calcium signals. In neurons, CaBPs are primarily localized to the cytosol and function, for example, in nerve terminals in short-term synaptic plasticity. However, CaBPs are also expressed in the cell nucleus, suggesting that they modulate nuclear calcium signals, which are key regulators of neuronal gene expression. Here we show that the calcium buffering capacity of the cell nucleus in mouse hippocampal neurons regulates neuronal architecture by modulating the expression levels of VEGFD and the complement factor C1q-c, two nuclear calcium-regulated genes that control dendrite geometry and spine density, respectively. Increasing the levels of nuclear calcium buffers by means of expression of a nuclearly targeted form of parvalbumin fused to mCherry (PV.NLS-mC) led to a reduction in VEGFD expression and, as a result, to a decrease in total dendritic length and complexity. In contrast, mRNA levels of the synapse pruning factor C1q-c were increased in neurons expressing PV.NLS-mC, causing a reduction in the density and size of dendritic spines. Our results establish a close link between nuclear calcium buffering capacity and the transcription of genes that determine neuronal structure. They suggest that the development of cognitive deficits observed in neurological conditions associated with CaBP deregulation may reflect the loss of necessary structural features of dendrites and spines. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Impact of mineral and bone disorder on healthcare resource use and associated costs in the European Fresenius medical care dialysis population: a retrospective cohort study.

PubMed

Chiroli, Silvia; Mattin, Caroline; Belozeroff, Vasily; Perrault, Louise; Mitchell, Dominic; Gioni, Ioanna

2012-10-29

Secondary hyperparathyroidism (SHPT) is associated with mortality in patients with chronic kidney disease (CKD), but the economic consequences of SHPT have not been adequately studied in the European population. We assessed the relationship between SHPT parameters (intact parathyroid hormone [iPTH], calcium, and phosphate) and hospitalisations, medication use, and associated costs among CKD patients in Europe. The analysis of this retrospective cohort study used records of randomly selected patients who underwent haemodialysis between January 1, 2005 and December 31, 2006 at participating European Fresenius Medical Care facilities in 10 countries. Patients had ≥ 1 iPTH value recorded, and ≥ 1 month of follow-up after a 3-month baseline period during which SHPT parameters were assessed. Time at risk was post-baseline until death, successful renal transplantation, loss to follow-up, or the end of follow-up. Outcomes included cost per patient-month, rates of hospitalisations (cardiovascular disease [CVD], fractures, and parathyroidectomy [PTX]), and use of SHPT-, diabetes-, and CVD-related medications. National costs were applied to hospitalisations and medication use. Generalised linear models compared costs across strata of iPTH, total calcium, and phosphate, adjusting for baseline covariates. There were 6369 patients included in the analysis. Mean ± SD person-time at risk was 13.1 ± 6.4 months. Patients with iPTH > 600 pg/mL had a higher hospitalisation rate than those with lower iPTH. Hospitalisation rates varied little across calcium and phosphate levels. SHPT-related medication use varied with iPTH, calcium, and phosphate. After adjusting for demographic and clinical variables, patients with baseline iPTH > 600 pg/mL had 41% (95% CI: 25%, 59%) higher monthly total healthcare costs compared with those with iPTH in the K/DOQI target range (150-300 pg/mL). Patients with baseline phosphate and total calcium levels above target ranges (1.13-1.78 mmol/L and 2.10-2.37 mmol/L, respectively) had 38% (95% CI: 27%, 50%) and 8% (95% CI: 0%, 17%) higher adjusted monthly costs, respectively. Adjusted costs were 25% (95% CI: 18%, 32%) lower among patients with baseline phosphate levels below the target range. Results were consistent in sensitivity analyses. These data suggest that elevated SHPT parameters increase the economic burden of CKD in Europe.

Micronutrient status (calcium, zinc, vitamins D and E) in patients with medullary thyroid carcinoma: A cross-sectional study.

PubMed

Emami, Ali; Nazem, Mohammad Reza; Shekarriz, Reza; Hedayati, Mehdi

2017-09-01

The aim of this study was to evaluate the micronutrient status of Iranian patients with medullary thyroid carcinoma (MTC) and to analyze potential relationships with respect to MTC risk. This was a cross-sectional study (Tehran Thyroid Cancer Survey 2015-2016). We measured and compared preoperative serum calcium, zinc, and vitamins D and E in patients with MTC and healthy controls. Forty cases with MTC and 40 (age-, sex-, and body mass index-matched) healthy controls voluntarily participated in the project. Serum calcium, zinc, and vitamin D and E concentrations were lower in the patients with cancer (P Ca < 0.001, P Zn  = 0.01, P D  = 0.056, P E  = 0.002) than in the healthy controls. We found that serum calcium remarkably associated with enhanced risk for thyroid cancer (odds ratio [OR], 6.5; P = 0.001). Likewise, serum vitamin E was linked to the risk for cancer (OR, 1.31; P = 0.056). Moreover, serum zinc was correlated with vitamin E and calcium (r = +0.23; P = 0.04 and r = +0.25, P = 0.03; respectively). We also observed a correlation between calcium and vitamin E (r = +0.27; P = 0.02). A multiple-micronutrient decrease was confirmed in patients with MTC. A low serum calcium level was a potent risk factor for MTC. Findings from the present study suggest that dietary intake and/or supplementation of micronutrients, especially calcium and vitamin E, may be beneficial in reducing the risk for thyroid cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

Correlation between carotid bifurcation calcium burden on non-enhanced CT and percentage stenosis, as confirmed by digital subtraction angiography

PubMed Central

Sarikaya, B; Lohman, B; Mckinney, A M; Gadani, S; Irfan, M; Lucato, L

2012-01-01

Objectives Previous evidence supports a direct relationship between the calcium burden (volume) on post-contrast CT with the percent internal carotid artery (ICA) stenosis at the carotid bifurcation. We sought to further investigate this relationship by comparing non-enhanced CT (NECT) and digital subtraction angiography (DSA). Methods 50 patients (aged 41–82 years) were retrospectively identified who had undergone cervical NECT and DSA. A 64-multidetector array CT (MDCT) scanner was utilised and the images reviewed using preset window widths/levels (30/300) optimised to calcium, with the volumes measured via three-dimensional reconstructive software. Stenosis measurements were performed on DSA and luminal diameter stenoses >40% were considered “significant”. Volume thresholds of 0.01, 0.03, 0.06, 0.09 and 0.12 cm3 were utilised and Pearson'S correlation coefficient (r) was calculated to correlate the calcium volume with percent stenosis. Results Of 100 carotid bifurcations, 88 were available and of these 7 were significantly stenotic. The NECT calcium volume moderately correlated with percent stenosis on DSA r=0.53 (p<0.01). A moderate–strong correlation was found between the square root of calcium volume on NECT with percent stenosis on DSA (r=0.60, p<0.01). Via a receiver operating characteristic curve, 0.06 cm3 was determined to be the best threshold (sensitivity 100%, specificity 90.1%, negative predictive value 100% and positive predictive value 46.7%) for detecting significant stenoses. Conclusion This preliminary investigation confirms a correlation between carotid bifurcation calcium volume and percent ICA stenosis and is promising for the optimal threshold for stenosis detection. Future studies could utilise calcium volumes to create a “score” that could predict high grade stenosis. PMID:21896662

Osteoporosis Knowledge, Calcium Intake, and Weight-Bearing Physical Activity in Three Age Groups of Women.

ERIC Educational Resources Information Center

Terrio, Kate; Auld, Garry W.

2002-01-01

Determined the extent and integration of osteoporosis knowledge in three age groups of women, comparing knowledge to calcium intake and weight bearing physical activity (WBPA). Overall calcium intake was relatively high. There were no differences in knowledge, calcium intake, or WBPA by age, nor did knowledge predict calcium intake and WBPA. None…

HIV associated hypocalcaemia among diarrheic patients in northwest Ethiopia: a cross sectional study.

PubMed

Moges, Beyene; Amare, Bemnet; Yabutani, Timoki; Kassu, Afework

2014-07-04

Hypocalcaemia, defined by serum calcium level less than 8.5 mg/dl, could be caused by human immunodeficiency virus (HIV) and diarrheal diseases. In Ethiopia, while morbidities from diarrheal diseases and HIV are serious health problems, studies assessing the interactions amongst of the three do not exist. Therefore, the present study was undertaken to investigate the level of calcium among diarrheic patients with and without HIV co-infection. Consecutive diarrheic patients attending Gondar University Hospital in Ethiopia were enrolled and screened for HIV, intestinal parasites, Shigella and Salmonella. Concentration of calcium in serum was determined using an inductively coupled plasma mass spectrometer. A total of 206 diarrheic patients were included in the study (109 = HIV positive, 97 = HIV negative). Intestinal parasites and Shigella species were detected in 32.2% and 8.5% of the patients, respectively. The serum calcium levels in the patients who were found positive for Shigella species or intestinal parasites was not significantly different by the presence or absence of HIV co-infection. HIV infected diarrheic patients had significantly lower mean serum calcium levels (7.82 ± 1.23 mg/dl) than those negative for HIV (8.38 ± 1.97) (P = 0.015). The age groups 25-35 and greater than 45 years showed significantly lower mean serum calcium levels (7.77 ± 1.55 mg/dl) in comparison to the other age groups (7.84 ± 1.41 mg/dl, P = 0.009). On the other hand, females presented with significantly lower mean serum calcium levels (7.79 ± 1.60 mg/dl, P = 0.044) than males (8.26 ± 1.65 mg/dl). There is high prevalence of hypocalcaemia among diarrheic patients in northwest Ethiopia. And HIV stood out to be a major risk factor for development of hypocalcaemia among the diarrheic patients in northwest Ethiopia. Further studies are required to substantiate and characterize the mechanisms and consequences of calcium metabolism disorders among HIV infected individuals in the study area.

Influence of calcium oxide level and time of exposure to sugarcane on in vitro and in situ digestion kinetics

USDA-ARS?s Scientific Manuscript database

Experiments were carried out to evaluate, using in vitro and in situ techniques, the effects of three inclusion levels of calcium oxide (0, 5, and 10 g/kg of sugarcane fresh matter) and four exposure times (0, 24, 48, and 72 h) of sugarcane to calcium oxide on the chemical composition and digestive ...

Does dietary calcium interact with dietary fiber against colorectal cancer? A case-control study in Central Europe.

PubMed

Galas, Aleksander; Augustyniak, Malgorzata; Sochacka-Tatara, Elzbieta

2013-10-04

An unfavorable trend of increasing rates of colorectal cancer has been observed across modern societies. In general, dietary factors are understood to be responsible for up to 70% of the disease's incidence, though there are still many inconsistencies regarding the impact of specific dietary items. Among the dietary minerals, calcium intake may play a crucial role in the prevention. The purpose of this study was to assess the effect of intake of higher levels of dietary calcium on the risk of developing of colorectal cancer, and to evaluate dose dependent effect and to investigate possible effect modification. A hospital based case-control study of 1556 patients (703 histologically confirmed colon and rectal incident cases and 853 hospital-based controls) was performed between 2000-2012 in Krakow, Poland. The 148-item semi-quantitative Food Frequency Questionnaire to assess dietary habits and level of nutrients intake was used. Data regarding possible covariates was also collected. After adjustment for age, gender, education, consumption of fruits, raw and cooked vegetables, fish, and alcohol, as well as for intake of fiber, vitamin C, dietary iron, lifetime recreational physical activity, BMI, smoking status, and taking mineral supplements, an increase in the consumption of calcium was associated with the decrease of colon cancer risk (OR = 0.93, 95% CI: 0.89-0.98 for every 100 mg Ca/day increase). Subjects consumed >1000 mg/day showed 46% decrease of colon cancer risk (OR = 0.54, 95% CI: 0.35-0.83). The effect of dietary calcium was modified by dietary fiber (p for interaction =0.015). Finally, consistent decrease of colon cancer risk was observed across increasing levels of dietary calcium and fiber intake. These relationships were not proved for rectal cancer. The study confirmed the effect of high doses of dietary calcium against the risk of colon cancer development. This relationship was observed across different levels of dietary fiber, and the beneficial effect of dietary calcium depended on the level of dietary fiber suggesting modification effect of calcium and fiber. Further efforts are needed to confirm this association, and also across higher levels of dietary fiber intake.

In Vitro Release and Bioavailability of Silybin from Micelle-Templated Porous Calcium Phosphate Microparticles.

PubMed

Zhu, Yuan; Wang, Miaomiao; Zhang, Ya; Zeng, Jin; Omari-Siaw, E; Yu, Jiangnan; Xu, Ximing

2016-10-01

Developing a promising carrier for the delivery of poorly water-soluble drugs, such as silybin, to improve oral absorption has become a very worthy of consideration. The goal of this study was to prepare a novel porous calcium phosphate microparticle using povidone-mixed micelles as template while evaluating its in vitro and in vivo properties with silybin as a model drug. The particle characterization, in vitro drug release behavior, and pharmacokinetic parameters of the prepared silybin-loaded calcium phosphate microparticle were investigated. The mean particle size was found to be 3.54 ± 0.32 μm with a rough surface porous structure. Additionally, the silybin-loaded calcium phosphate microparticle compared with the free silybin showed a prolonged 72-h release in vitro and a higher C max (418.5 ± 23.7 ng mL(-1)) with 167.5% oral relative bioavailability. A level A in vitro-in vivo correlation (IVIVC), established for the first time, demonstrated an excellent IVIVC of the formulated silybin in oral administration. In conclusion, this povidone-mixed micelle-based microparticle was successfully prepared to enhance the oral bioavailability of silybin. Therefore, application of this novel porous calcium phosphate microparticle holds a significant potential for the development of poorly water-soluble drugs.

Vitamin D, PTH, and calcium in relation to survival following prostate cancer.

PubMed

Brändstedt, Johan; Almquist, Martin; Manjer, Jonas; Malm, Johan

2016-05-01

Epidemiological studies suggest that low levels of vitamin D constitute a risk factor for prostate cancer. However, the results are conflicting, perhaps because prostate cancer is a very heterogeneous disease. More recent studies have focused on cancer progression and mortality. Vitamin D is closely related to both calcium metabolism and parathyroid hormone (PTH) levels, and all three factors have been implicated in prostate cancer. We examined the associations between pre-diagnostic serum levels of vitamin D (25OHD), PTH, and calcium and mortality among 943 participants within the Malmö Diet and Cancer Study, who were diagnosed with prostate cancer. The mean time from diagnosis until the end of followup was 9.1 years (SD 4.5), and the mean time from inclusion until end of follow-up was 16.6 years (SD 4.9). The analytes were divided into quartiles, and the risk of death from prostate cancer was analyzed using Cox proportional hazard analysis, yielding hazards ratios (HR) with 95 % confidence intervals. The models were adjusted for season and year of inclusion, age at baseline, age at diagnosis, body mass index (BMI), and tumor characteristics (TNM and Gleason score). We observed a trend toward a lower prostate-specific mortality with 25OHD >85 nmol/L in the unadjusted analysis. This became statistically significantly in the third quartile of 25OHD (85-102 nmol/L) compared to the first (<68 nmol/L), HR 0.54 (0.34-0.85) when adjusting for age, time of inclusion, and BMI. The association was further strengthened when adjusted for age at diagnosis, Gleason score, and TNM classification with a HR in Q3 0.36 (0.22-0.60). p for trend was 0.03. Regarding calcium, there was a significantly lower HR for the second quartile (2.35-2.39 mmol/L) compared to the first (≤2.34 mmol/L) with a HR of 0.54 (0.32-0.86) in the unadjusted analysis. However, this association disappeared when adjusting for tumor characteristics. There were no associations between levels of PTH and prostate cancer mortality. This study shows that levels of pre-diagnostic vitamin D above 85 nmol/L may improve survival in men with prostate cancer.

Involvement of endoplasmic reticulum in hepatitis B virus replication.

PubMed

Xia, Weiliang; Shen, Yan; Xie, Haiyang; Zheng, Shusen

2006-11-01

The mitochondrial calcium and downstream proline-rich tyrosine kinase-2 (PyK2) signaling pathway are critical to hepatitis B virus (HBV) replication, and the endoplasmic reticulum (ER) plays an important role in intracellular calcium regulation. To investigate the role of ER in HBV replication, the HBV genome transfected HepG2.2.15 cells were treated by cyclosporine A (CsA), cyclopiazonic acid (CPA), ryanodine and U73122, which are all specific blockers of calcium channels located in either ER or mitochondria. The HBV replication level was evaluated by two methods: slot blot hybridization analysis of intracellular HBV DNA and real-time polymerase chain reaction (PCR) analysis of secreted HBV DNA in supernatant; the activation of PyK2 kinase was detected by Western blot analysis. Results indicated that the HBV replication was inhibited when mitochondrial permeability transition pore, ER Ca2+ -ATPase and ER inositol 1,4,5-trisphosphate receptor (IP3R) were blocked by CsA, CPA and U73122, respectively; but not inhibited when ER ryanodine receptor was blocked by ryanodine. The PyK2 phosphorylation level declined after treatment of 2 microg/ml CsA, 5 microM CPA and 25 microM U73122, but not changed apparently after 50 microM ryanodine treatment. Compared with monotreatment, a more powerful inhibitory effect was achieved when the CsA, CPA and U73122 were combined used in twosome or triple manner, while the HBV replication level did not change apparently when ryanodine combined with CsA, CPA or U73122. In conclusion, besides the mitochondria, the ER also participates in the HBV replication through calcium-PyK2 signaling pathway; the calcium channels of ER Ca2+ -ATPase and ER IP3R are responsible for this role; during this complicated process, an interaction between ER and mitochondria maybe involved.

Postoperative hypocalcemia after thyroidectomy for Graves' disease.

PubMed

Pesce, Catherine E; Shiue, Zita; Tsai, Hua-Ling; Umbricht, Christopher B; Tufano, Ralph P; Dackiw, Alan P B; Kowalski, Jeanne; Zeiger, Martha A

2010-11-01

It is believed that patients who undergo thyroidectomy for Graves' disease are more likely to experience postoperative hypocalcemia than patients undergoing total thyroidectomy for other indications. However, no study has directly compared these two groups of patients. The aim of this study was to determine whether there was an increased incidence or severity of postoperative hypocalcemia in patients who underwent thyroidectomy for Graves' disease. An institutional review board-approved database was created of all patients who underwent thyroidectomy from 1998 to 2009 at the Johns Hopkins Hospital. There were a total of 68 patients with Graves' disease who underwent surgery. Fifty-five patients who underwent total thyroidectomy were randomly selected and served as control subjects. An analysis was conducted that examined potential covariates for postoperative hypocalcemia, including age, gender, ethnicity, preoperative alkaline phosphatase level, size of goiter, whether parathyroid tissue or glands were present in the specimen, and the reason the patient underwent surgery. Specific outcomes examined were calcium levels on postoperative day 1, whether or not patients experienced symptoms of hypocalcemia, whether or not Rocaltrol was required, the number of calcium tablets prescribed upon discharge, whether or not postoperative tetany occurred, and calcium levels 1 month after discharge. Each outcome was analyzed using a logistic regression. Graves' disease patients had a significantly (p-value < 0.001) higher odds of greater number of calcium tablets prescribed upon discharge. Further, 6 of 68 patients with Graves' disease and no patient in the control group were readmitted with tetany (p = 0.033). There was a trend, though not significant, toward patients with Graves' disease having a higher prevalence of hypocalcemia the day after thyroidectomy and 1 month later. Patients with Graves' disease are more likely to require increased dosages of calcium as well as experience tetany postoperatively than patients undergoing total thyroidectomy for other indications. This suggests that patients operated upon for Graves' disease warrant close followup as both inpatients and outpatients for signs and symptoms of hypocalcemia.

Biochemical Predictors of Low Bone Mineral Density and Fracture Susceptibility in Maltese Postmenopausal Women.

PubMed

Formosa, Melissa M; Xuereb-Anastasi, Angela

2016-01-01

Osteoporosis and fractures are complex conditions influenced by an interplay of genetic and environmental factors. The aim of the study was to investigate three biochemical parameters including total serum calcium, total serum alkaline phosphatase (sALP) and albumin in relation to bone mineral density (BMD) at the lumbar spine and femoral neck (FN), and with all-type of low-trauma fractures in Maltese postmenopausal women. Levels were also correlated with age and physical activity. A case-control study of 1045 women was performed. Women who suffered a fracture were classified as cases whereas women without a fracture history were included as controls subdivided into normal, osteopenic, or osteoporotic according to their BMD measurements. Blood specimens were collected following good standard practice and testing was performed by spectrophotometry. Calcium and sALP levels were weakly correlated with FN BMD levels (calcium: r = -0.111, p = 0.002; sALP: r = 0.089, p = 0.013). Fracture cases had the lowest serum levels of calcium, sALP and albumin relative to all other control groups, which decreased with increasing age, possibly increasing fracture risk. Biochemical levels were lowest in women who sustained a hip fracture and more than one fracture. Biochemical parameters decreased with reduced physical activity; however, this was most evident for fracture cases. Reduced physical activity was associated with lower BMD levels at the hip, and to a lower extent at the spine. In conclusion, results suggest that levels of serum calcium and albumin could be indicative of fracture risk, whereas calcium levels and to lower extent sALP levels could be indicators of hip BMD.

Serum levels of 25-hydroxyvitamin D in a year of residence on the Antarctic continent.

PubMed

Oliveri, M B; Mautalen, C; Bustamante, L; Gómez García, V

1994-06-01

Since exposure to sunlight is the main source of vitamin D in human beings and skin photosynthesis decreases markedly as the latitude increases, we studied the changes in serum 25-hydroxyvitamin D (25(OH)D) levels in young healthy men who lived in the Antarctic Continent during 1 year. Blood was drawn in the fasting state every 2 months from March 1990 to January 1991 to determine the serum levels of calcium, alkaline phosphatase and 25(OH)D. 19 healthy volunteers, who left Buenos Aires (34 degrees S) during the 1990 summer, arriving at the Antarctic bases at the end of January (Belgrano) and in mid-March (San Martín) and stayed there up to summer 1991. Serum calcium did not change significantly throughout the year. Serum alkaline phosphatase levels were not different comparing the beginning to the end of the year, but autumn and winter levels were lower (P < 0.05). At Belgrano Base the serum 25(OH)D levels (ng/ml) decreased from (mean +/- SD) 18.7 +/- 7.4 (March) to 10.0 +/- 4.3 (July) (P < 0.005) and did not recover for the rest of the year. At San Martín Base the serum 25(OH)D levels descended from 22.0 +/- 5.4 in March to 12.2 +/- 3.7 in August (P < 0.02) and did not increase even at the beginning of summer (January) except in two men with frequent outdoor activities. The levels of 25(OH)D of healthy men living in the Antarctic continent decreased to approximately 46% of the initial values and did not increase even at the onset of summer. Further studies should determine the effect of these changes upon calcium-regulating hormones and bone metabolism.

The timing of calcium measurements in helping to predict temporary and permanent hypocalcaemia in patients having completion and total thyroidectomies.

PubMed

Pfleiderer, A G; Ahmad, N; Draper, M R; Vrotsou, K; Smith, W K

2009-03-01

Postoperative hypocalaemia commonly occurs after extensive thyroid surgery and may require calcium and/or vitamin D supplements to alleviate or prevent the symptoms. In this study, we determined the risk factors for developing hypocalcaemia and whether early serum calcium levels can predict the development of or differentiate between temporary or permanent hypocalcaemia. A total of 162 patients who either had a completion or total thyroidectomy formed the basis of this prospective study. Serial serum calcium measurements were recorded as well as details of the operation, pathology, indications for surgery, number of parathyroids identified at operation and any complications. Eighty-four (52%) patients did not develop hypocalcaemia but 69 (43%) were found to have temporary hypocalcaemia and 9 (5%) had permanent hypocalcaemia. Hypocalcaemia was more common after total than completion thyroidectomies and the identification of parathyroids at operation appears to have a significant adverse effect on outcome. The calcium levels measured on day 1 postoperatively and the slope (serum calcium levels of day 1 postoperative minus day of operation) were statistically significant in predicting the development of hypocalcaemia and possibly to differentiate between temporary or permanent hypocalcaemia. Although almost half the patients having extensive thyroid surgery developed hypocalcaemia (as defined by any postoperative corrected serum calcium level of < 2.12 mmol/l) only 24% had a serum calcium of < 2.12 mmol/l associated with clinical symptoms of hypocalcaemia or a calcium level of < 2.0 mmol/l. Only 5% had persistent hypocalcaemia defined as requiring exogenous supplements at 6 months' postoperatively. Patients having a completion thyroidectomy appear to be less likely to develop hypocalcaemia perhaps as a result of any iatrogenic effects on the parathyroids at the first operation being reversed before the second operation. Identification and, therefore, exposure of parathyroids at operation may have an adverse effect on the blood supply to the glands affecting their function. Serum calcium levels measured 6 hours' post-surgery and on day 1 postoperatively can be useful in predicting if the patient will develop hypocalcaemia and the slope may indicate whether the hypocalcaemia will be temporary or permanent. Patients with toxic goitres and those having a one-stage total thyroidectomy are most at risk of developing hypocalcaemia.

The Timing of Calcium Measurements in Helping to Predict Temporary and Permanent Hypocalcaemia in Patients Having Completion and Total Thyroidectomies

PubMed Central

Pfleiderer, AG; Ahmad, N; Draper, MR; Vrotsou, K; Smith, WK

2009-01-01

INTRODUCTION Postoperative hypocalaemia commonly occurs after extensive thyroid surgery and may require calcium and/or vitamin D supplements to alleviate or prevent the symptoms. In this study, we determined the risk factors for developing hypocalcaemia and whether early serum calcium levels can predict the development of or differentiate between temporary or permanent hypocalcaemia. PATIENTS AND METHODS A total of 162 patients who either had a completion or total thyroidectomy formed the basis of this prospective study. Serial serum calcium measurements were recorded as well as details of the operation, pathology, indications for surgery, number of parathyroids identified at operation and any complications. RESULTS Eighty-four (52%) patients did not develop hypocalcaemia but 69 (43%) were found to have temporary hypocalcaemia and 9 (5%) had permanent hypocalcaemia. Hypocalcaemia was more common after total than completion thyroidectomies and the identification of parathyroids at operation appears to have a significant adverse effect on outcome. The calcium levels measured on day 1 postoperatively and the slope (serum calcium levels of day 1 postoperative minus day of operation) were statistically significant in predicting the development of hypocalcaemia and possibly to differentiate between temporary or permanent hypocalcaemia. DISCUSSION Although almost half the patients having extensive thyroid surgery developed hypocalcaemia (as defined by any postoperative corrected serum calcium level of < 2.12 mmol/l) only 24% had a serum calcium of < 2.12 mmol/l associated with clinical symptoms of hypocalcaemia or a calcium level of < 2.0 mmol/l. Only 5% had persistent hypocalcaemia defined as requiring exogenous supplements at 6 months' postoperatively. Patients having a completion thyroidectomy appear to be less likely to develop hypocalcaemia perhaps as a result of any iatrogenic effects on the parathyroids at the first operation being reversed before the second operation. Identification and, therefore, exposure of parathyroids at operation may have an adverse effect on the blood supply to the glands affecting their function. CONCLUSIONS Serum calcium levels measured 6 hours' post-surgery and on day 1 postoperatively can be useful in predicting if the patient will develop hypocalcaemia and the slope may indicate whether the hypocalcaemia will be temporary or permanent. Patients with toxic goitres and those having a one-stage total thyroidectomy are most at risk of developing hypocalcaemia. PMID:19317937

Calcium and Vitamin D: Important at Every Age

MedlinePlus

... 100 Turnip greens, boiled, ½ cup 99 Broccoli, raw, 1 cup 90 Ice cream, vanilla, ½ cup 85 Soy or rice milk, fortified with calcium, 1 cup 80–500 (varies) Calcium Culprits Although a balanced diet aids calcium absorption, high levels of protein and sodium (salt) in the diet are thought ...

Calcium as a signal integrator in developing epithelial tissues.

PubMed

Brodskiy, Pavel A; Zartman, Jeremiah J

2018-05-16

Decoding how tissue properties emerge across multiple spatial and temporal scales from the integration of local signals is a grand challenge in quantitative biology. For example, the collective behavior of epithelial cells is critical for shaping developing embryos. Understanding how epithelial cells interpret a diverse range of local signals to coordinate tissue-level processes requires a systems-level understanding of development. Integration of multiple signaling pathways that specify cell signaling information requires second messengers such as calcium ions. Increasingly, specific roles have been uncovered for calcium signaling throughout development. Calcium signaling regulates many processes including division, migration, death, and differentiation. However, the pleiotropic and ubiquitous nature of calcium signaling implies that many additional functions remain to be discovered. Here we review a selection of recent studies to highlight important insights into how multiple signals are transduced by calcium transients in developing epithelial tissues. Quantitative imaging and computational modeling have provided important insights into how calcium signaling integration occurs. Reverse-engineering the conserved features of signal integration mediated by calcium signaling will enable novel approaches in regenerative medicine and synthetic control of morphogenesis.

[Calcium carbonate for the treatment of hyperphosphatemia in chronic hemodialysis patients].

PubMed

Kiss, D; Battegay, M; Meier, C; Lyrer, A

1990-03-03

Hyperphosphatemia in chronic hemodialysis patients is usually treated with aluminium containing phosphate binders. In recent years there has been increasing evidence of serious complications due to aluminium accumulation. We have investigated a new calcium carbonate preparation with an HCl-resistant capsule designed to prevent gastrointestinal side effects. Its phosphate binding capacity in comparison to aluminium chloride hydroxide was investigated in 17 chronic hemodialysis patients. The dose of the phosphate binder was adjusted regularly so that the serum phosphorus levels were below 1.8 mmol/l. The mean dose of aluminium chloride hydroxide was 3.36 g/day and of calcium carbonate 4.96 g/day. The mean (+/- SD) serum calcium level was 2.58 +/- 0.11 mmol/l under aluminium chloride hydroxide and 2.50 +/- 0.25 mmol/l under calcium carbonate. The mean phosphorus level was 1.69 +/- 0.31 mmol/l under aluminium chloride hydroxide and 1.71 +/- 0.33 under calcium carbonate. Serum aluminium fell from 64.5 +/- 14.4 micrograms/l to 28.5 +/- 17.5 micrograms/l after 3 months.

Modeled microgravity-induced protein kinase C isoform expression in human lymphocytes

NASA Technical Reports Server (NTRS)

Sundaresan, A.; Risin, D.; Pellis, N. R.

2004-01-01

In long-term space travel, the crew is exposed to microgravity and radiation that invoke potential hazards to the immune system. T cell activation is a critical step in the immune response. Receptor-mediated signaling is inhibited in both microgravity and modeled microgravity (MMG) as reflected by diminished DNA synthesis in peripheral blood lymphocytes and their locomotion through gelled type I collagen. Direct activation of protein kinase C (PKC) bypassing cell surface events using the phorbol ester PMA rescues MMG-inhibited lymphocyte activation and locomotion, whereas the calcium ionophore ionomycin had no rescue effect. Thus calcium-independent PKC isoforms may be affected in MMG-induced locomotion inhibition and rescue. Both calcium-dependent isoforms and calcium-independent PKC isoforms were investigated to assess their expression in lymphocytes in 1 g and MMG culture. Human lymphocytes were cultured and harvested at 24, 48, 72, and 96 h, and serial samples were assessed for locomotion by using type I collagen and expression of PKC isoforms. Expression of PKC-alpha, -delta, and -epsilon was assessed by RT-PCR, flow cytometry, and immunoblotting. Results indicated that PKC isoforms delta and epsilon were downregulated by >50% at the transcriptional and translational levels in MMG-cultured lymphocytes compared with 1-g controls. Events upstream of PKC, such as phosphorylation of phospholipase Cgamma in MMG, revealed accumulation of inactive enzyme. Depressed calcium-independent PKC isoforms may be a consequence of an upstream lesion in the signal transduction pathway. The differential response among calcium-dependent and calcium-independent isoforms may actually result from MMG intrusion events earlier than PKC, but after ligand-receptor interaction.

Physiological characterisation of a pH- and calcium-dependent sodium uptake mechanism in the freshwater crustacean, Daphnia magna.

PubMed

Glover, Chris N; Wood, Chris M

2005-03-01

Daphnia are highly sensitive to sodium metabolism disruption caused by aquatic acidification and ionoregulatory toxicants, due to their finely balanced ion homeostasis. Nine different water chemistries of varying pH (4, 6 and 8) and calcium concentration (0, 0.5 and 1 mmol l(-1)) were used to delineate the mechanism of sodium influx in Daphnia magna. Lowering water pH severely inhibited sodium influx when calcium concentration was high, but transport kinetic analysis revealed a stimulated sodium influx capacity (J(max)) when calcium was absent. At low pH increasing water calcium levels decreased J(max) and raised K(m) (decreased sodium influx affinity), while at high pH the opposite pattern was observed (elevated J(max) and reduced K(m)). These effects on sodium influx were mirrored by changes in whole body sodium levels. Further examination of the effect of calcium on sodium influx showed a severe inhibition of sodium uptake by 100 micromol l(-1) calcium gluconate at both low (50 micromol l(-1)) and high (1000 micromol l(-1)) sodium concentrations. At high sodium concentrations, stimulated sodium influx was noted with elevated calcium levels. These results, in addition to data showing amiloride inhibition of sodium influx (K(i)=180 micromol l(-1)), suggest a mechanism of sodium influx in Daphnia magna that involves the electrogenic 2Na(+)/1H(+) exchanger.

Role of calcium in phosphoinositide metabolism and inhibition of norepinephrine transport into synaptic vesicles by amphetamine analogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knepper, S.M.

1985-01-01

Norepinephrine-(NE) and calcium ionophore A23187-stimulated phosphoinositide (PIn) metabolism in rat brain slices was studied under varying calcium conditions. Tissue was labelled with /sup 3/H-myo-inositol and /sup 3/H-inositol phosphates (IPn), products of PIn metabolism were measured. In the absence of media calcium the response to NE was decreased while that to A23187 was little affected A23187 can release calcium from intracellular stores. Basal and stimulated accumulation of /sup 3/H-IPn was reversibly antagonized with EGTA by addition of calcium. Using calcium buffers, approximately 10/sup -7/ M free calcium was required to support hydrolysis. Free intracellular calcium is maintained at approximately this level.more » Thus calcium is required for PIn hydrolysis but appears to play a permissive role, basal levels being sufficient to support metabolism. Conformationally-defined (rigid) and -restricted (semi-rigid) analogs of the most stable conformations of amphetamine, antiperiplanar (exo) and gauche (endo), were utilized to probe the conformational requirements of vesicular NE transport. Analogs tested were 2-aminotetralin (2AT), 3-methyltetrahydroisoquinoline, anti- and syn-9-aminobenzobicyclo(2.2.1)heptene, and endo and exo conformers of 2-aminobenzobicyclo(2.2.1)heptene and 2-aminobenzobicyclo(2.2.2)octene.« less

Low-level overexpression of p53 promotes warfarin-induced calcification of porcine aortic valve interstitial cells by activating Slug gene transcription.

PubMed

Gao, Li; Ji, Yue; Lu, Yan; Qiu, Ming; Shen, Yejiao; Wang, Yaqing; Kong, Xiangqing; Shao, Yongfeng; Sheng, Yanhui; Sun, Wei

2018-03-09

The most frequently used oral anti-coagulant warfarin has been implicated in inducing calcification of aortic valve interstitial cells (AVICs), whereas the mechanism is not fully understood. The low-level activation of p53 is found to be involved in osteogenic transdifferentiation and calcification of AVICs. Whether p53 participates in warfarin-induced AVIC calcification remains unknown. In this study, we investigated the role of low-level p53 overexpression in warfarin-induced porcine AVIC (pAVIC) calcification. Immunostaining, quantitative PCR, and Western blotting revealed that p53 was expressed in human and pAVICs and that p53 expression was slightly increased in calcific human aortic valves compared with non-calcific valves. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling staining indicated that apoptosis slightly increased in calcific aortic valves than in non-calcific valves. Warfarin treatment led to a low-level increase of p53 mRNA and protein in both pAVICs and mouse aortic valves. Low-level overexpression of p53 in pAVICs via an adenovirus vector did not affect pAVIC apoptosis but promoted warfarin-induced calcium deposition and expression of osteogenic markers. shRNA-mediated p53 knockdown attenuated the pAVIC calcium deposition and osteogenic marker expression. Moreover, ChIP and luciferase assays showed that p53 was recruited to the slug promoter and activated slug expression in calcific pAVICs. Of note, overexpression of Slug increased osteogenic marker Runx2 expression, but not pAVIC calcium deposition, and Slug knockdown attenuated pAVIC calcification and p53-mediated pAVIC calcium deposition and expression of osteogenic markers. In conclusion, we found that p53 plays an important role in warfarin induced pAVIC calcification, and increased slug transcription by p53 is required for p53-mediated pAVIC calcification. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Mechanisms behind Post-Thyroidectomy Hypocalcemia: Interplay of Calcitonin, Parathormone, and Albumin-A Prospective Study.

PubMed

Chisthi, Meer M; Nair, Rakhi S; Kuttanchettiyar, Krishnakumar G; Yadev, Induprabha

2017-08-01

Hypocalcemia after thyroidectomy is attributed to injury or ischemia to parathyroid glands. Transient hypocalcemia in thyroidectomy when parathyroids are preserved is not adequately explained. Release of calcitonin and hypoalbuminemia are two proposed reasons. Primary objective of this study was to find the change in calcitonin in the postoperative period after total thyroidectomy. Secondarily, hypocalcemia and its correlation with calcitonin, albumin, and parathormone were also studied. This Cohort study was carried out at the general surgical department of a tertiary level teaching institution from April 2015 to December 2015. One hundred adult patients undergoing total thyroidectomy, with at least three parathyroids being preserved were included. Changes in calcium, calcitonin, albumin, and parathormone were studied based on preoperative levels and the values at 1, 6, 24, and 48 hr after surgery. Calcitonin increased at one hour after thyroidectomy and fell below preoperative levels subsequently. Parathormone showed a mild rise at one hour and normalized subsequently. Total calcium, corrected calcium, and albumin showed decline at one hour and recovered gradually over the next two days. At preoperative level, calcium had significant correlation with parathormone alone. Calcium levels at one hour had significant correlation with calcitonin. All post-operative calcium levels had significant correlation with parathormone and the number of parathyroids preserved in situ without auto-transplantation. There is significant hypocalcemia within the first 24 hr after thyroidectomy, caused by calcitonin release and hypoalbuminemia. Preservation of maximum number of parathyroids in-situ can counter and normalize this hypocalcemia.

Aromatase Deficient Female Mice Demonstrate Altered Expression of Molecules Critical for Renal Calcium Reabsorption

NASA Astrophysics Data System (ADS)

Öz, Orhan K.; Hajibeigi, Asghar; Cummins, Carolyn; van Abel, Monique; Bindels, René J.; Kuro-o, Makoto; Pak, Charles Y. C.; Zerwekh, Joseph E.

2007-04-01

The incidence of kidney stones increases in women after the menopause, suggesting a role for estrogen deficiency. In order to determine if estrogen may be exerting an effect on renal calcium reabsorption, we measured urinary calcium excretion in the aromatase-deficient female mouse (ArKO) before and following estrogen therapy. ArKO mice had hypercalciuria that corrected during estrogen administration. To evaluate the mechanism by which estrogen deficiency leads to hypercalciuria, we examined the expression of several proteins involved in distal tubule renal calcium reabsorption, both at the message and protein levels. Messenger RNA levels of TRPV5, TRPV6, calbindin-D28K, the Na+/Ca++ exchanger (NCX1), and the plasma membrane calcium ATPase (PMCA1b) were significantly decreased in kidneys of ArKO mice. On the other hand, klotho mRNA levels were elevated in kidneys of ArKO mice. ArKO renal protein extracts had lower levels of calbindin-D28K but higher levels of the klotho protein. Immunochemistry demonstrated increased klotho expression in ArKO kidneys. Estradiol therapy normalized the expression of TRPV5, calbindin-D28K, PMCA1b and klotho. Taken together, these results demonstrate that estrogen deficiency produced by aromatase inactivation is sufficient to produce a renal leak of calcium and consequent hypercalciuria. This may represent one mechanism leading to the increased incidence of kidney stones following the menopause in women.

Is excess calcium harmful to health?

PubMed

Daly, Robin M; Ebeling, Peter R

2010-05-01

Most current guidelines recommend that older adults and the elderly strive for a total calcium intake (diet and supplements) of 1,000 to 1,300 mg/day to prevent osteoporosis and fractures. Traditionally, calcium supplements have been considered safe, effective and well tolerated, but their safety has recently been questioned due to potential adverse effects on vascular disease which may increase mortality. For example, the findings from a meta-analysis of randomized controlled trials (currently published in abstract form only) revealed that the use of calcium supplements was associated with an ~30% increased risk of myocardial infarction. If high levels of calcium are harmful to health, this may alter current public health recommendations with regard to the use of calcium supplements for preventing osteoporosis. In this review, we provide an overview of the latest information from human observational and prospective studies, randomized controlled trials and meta-analyses related to the effects of calcium supplementation on vascular disease and related risk factors, including blood pressure, lipid and lipoprotein levels and vascular calcification.

TRP channels in calcium homeostasis: from hormonal control to structure-function relationship of TRPV5 and TRPV6.

PubMed

van Goor, Mark K C; Hoenderop, Joost G J; van der Wijst, Jenny

2017-06-01

Maintaining plasma calcium levels within a narrow range is of vital importance for many physiological functions. Therefore, calcium transport processes in the intestine, bone and kidney are tightly regulated to fine-tune the rate of absorption, storage and excretion. The TRPV5 and TRPV6 calcium channels are viewed as the gatekeepers of epithelial calcium transport. Several calciotropic hormones control the channels at the level of transcription, membrane expression, and function. Recent technological advances have provided the first near-atomic resolution structural models of several TRPV channels, allowing insight into their architecture. While this field is still in its infancy, it has increased our understanding of molecular channel regulation and holds great promise for future structure-function studies of these ion channels. This review will summarize the mechanisms that control the systemic calcium balance, as well as extrapolate structural views to the molecular functioning of TRPV5/6 channels in epithelial calcium transport. Copyright © 2016. Published by Elsevier B.V.

Is Excess Calcium Harmful to Health?

PubMed Central

Daly, Robin M.; Ebeling, Peter R.

2010-01-01

Most current guidelines recommend that older adults and the elderly strive for a total calcium intake (diet and supplements) of 1,000 to 1,300 mg/day to prevent osteoporosis and fractures. Traditionally, calcium supplements have been considered safe, effective and well tolerated, but their safety has recently been questioned due to potential adverse effects on vascular disease which may increase mortality. For example, the findings from a meta-analysis of randomized controlled trials (currently published in abstract form only) revealed that the use of calcium supplements was associated with an ~30% increased risk of myocardial infarction. If high levels of calcium are harmful to health, this may alter current public health recommendations with regard to the use of calcium supplements for preventing osteoporosis. In this review, we provide an overview of the latest information from human observational and prospective studies, randomized controlled trials and meta-analyses related to the effects of calcium supplementation on vascular disease and related risk factors, including blood pressure, lipid and lipoprotein levels and vascular calcification. PMID:22254038

Effect of animal and vegetable protein intake on oxalate excretion in idiopathic calcium stone disease.

PubMed

Marangella, M; Bianco, O; Martini, C; Petrarulo, M; Vitale, C; Linari, F

1989-04-01

Oxalate excretion was measured in healthy subjects and idiopathic calcium stone-formers on dietary regimens which differed in the type and amount of protein allowed; 24-h urine collections were obtained from 41 practising vegetarians and 40 normal persons on a free, mixed, "mediterranean" diet. Twenty idiopathic calcium stone-formers were also studied while on two low calcium, low oxalate diets which differed in that animal protein was high in one and restricted in the other. Vegetarians had higher urinary oxalate levels than controls and although the calcium levels were markedly lower, urinary saturation with calcium/oxalate was significantly higher. This mild hypercalciuria was interpreted as being secondary to both a higher intake and increased fractional intestinal absorption of oxalate. Changing calcium stone-formers from a high to a low animal protein intake produced a significant decrease in calcium excretion but there was no variation in urinary oxalate. As a result, the decrease in calcium oxalate saturation was only marginal and not significant. It was concluded that dietary animal protein has a minimal effect on oxalate excretion. Mild hyperoxaluria of idiopathic calcium stone disease is likely to be intestinal in origin. Calcium stone-formers should be advised to avoid an excess of animal protein but the risks of a vegetable-rich diet should also be borne in mind.

Fasting serum CGRP levels are related to calcium concentrations, but cannot be elevated by short-term calcium/vitamin D supplementation.

PubMed

Hu, Fudong; Chen, Lianglong; Che, Hailan; Fang, Jun; Lv, Fenghua; Li, Hongjun; Zhang, Surong; Guo, Changlei; Yin, Honglei; Zhang, Shaoli; Zuo, Yulan

2015-02-01

Calcitonin gene-related peptide (CGRP) is an important cardioprotective neuropeptide. Few studies have shown that calcium supplementation may increase CGRP levels transiently. However, the relationship between CGRP and calcium is poorly known. This study was to explore the correlation between serum calcium and CGRP in coronary artery disease (CAD), and observe whether short-term calcium/vitamin D supplementation would increase fasting serum CGRP. A randomized, placebo-controlled and double-blind clinical trial, and a supplementary study for further analysis of the correlations were conducted. The results showed that the correlation between serum calcium and CGRP was positive in CAD without myocardial infarction (MI) (r = 0.487, P = 0.029), but negative in acute and healing MI (r = -0.382, P = 0.003). Moreover, we found a positive correlation between lg (amino-terminal pro-B-type natriuretic peptide, NT-proBNP) and CGRP (r = 0.312, P = 0.027), but a negative correlation between lg (NT-proBNP) and serum calcium (r = -0.316, P = 0.025) in acute and healing MI. As to the clinical trial, participants subjected to CAD but without evolving or acute MI, together with blood calcium ≤ 2.4 mmol/L, were randomized into three groups. Among the groups of placebo, caltrate (600 mg elemental calcium; 125 IU vitamin D3, per tablet) 1 tablet/d and caltrate 2 tablets/d, there were no significant differences in baseline characteristics. After short-term (5 days) treatments, the results indicated that the effect of grouping was not statistically significant (P = 0.915). In conclusion, the correlations between serum calcium and CGRP in different types of CAD are inconsistent, and the main reason may be associated with elevated natriuretic peptides after acute MI. Further, our study shows that short-term calcium/vitamin D supplementation cannot significantly increase fasting serum CGRP levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Naringin administration inhibits platelet aggregation and release by reducing blood cholesterol levels and the cytosolic free calcium concentration in hyperlipidemic rabbits

PubMed Central

XIAO, YANG; LI, LAI-LAI; WANG, YAN-YAN; GUO, JING-JING; XU, WEN-PING; WANG, YAN-YAN; WANG, YI

2014-01-01

This study investigated the effects of naringin on platelet aggregation and release in hyperlipidemic rabbits, and the underlying mechanisms. The safety of naringin was also investigated. The rabbits were orally administered 60, 30 or 15 mg/kg of naringin once a day for 14 days after being fed a high fat/cholesterol diet for four weeks. Following the two weeks of drug administration, the degree of platelet aggregation induced by arachidonic acid, adenosine diphosphate and collagen was significantly reduced by naringin at certain doses compared with those in the rabbits of the model group (P<0.01). The levels of P-selectin and platelet factor 4 (PF4) also decreased following treatment with naringin compared with those of the model group. Certain doses of naringin significantly reduced the total cholesterol (TC) levels and elevated the ratio of high-density lipoprotein cholesterol to TC compared with those in the model group, and significantly decreased the cytosolic free calcium concentration ([Ca2+]i). No significant difference in the coagulation function was observed between the control and drug-treatment groups. These results indicate that naringin improved platelet aggregation and inhibited the excessive release of P-selectin and PF4 in hyperlipidemic rabbits. This study suggests that the antiplatelet effect of naringin may be due to its ability to regulate the levels of blood cholesterol and [Ca2+]i in platelets. Naringin also did not cause bleeding in the hyperlipidemic rabbits. PMID:25120631

Calcium and phosphorus regulatory hormones and risk of incident symptomatic kidney stones.

PubMed

Taylor, Eric N; Hoofnagle, Andrew N; Curhan, Gary C

2015-04-07

Calcium and phosphorus regulatory hormones may contribute to the pathogenesis of calcium nephrolithiasis. However, there has been no prospective study to date of plasma hormone levels and risk of kidney stones. This study aimed to examine independent associations between plasma levels of 1,25-dihydroxyvitamin D (1,25[OH]2D), 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, fibroblast growth factor 23 (FGF23), parathyroid hormone, calcium, phosphate, and creatinine and the subsequent risk of incident kidney stones. This study was a prospective, nested case-control study of men in the Health Professionals Follow-Up Study who were free of diagnosed nephrolithiasis at blood draw. During 12 years of follow-up, 356 men developed an incident symptomatic kidney stone. Using risk set sampling, controls were selected in a 2:1 ratio (n=712 controls) and matched for age, race, and year, month, and time of day of blood collection. Baseline plasma levels of 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, parathyroid hormone, calcium, phosphate, and creatinine were similar in cases and controls. Mean 1,25(OH)2D and median FGF23 levels were higher in cases than controls but differences were small and statistically nonsignificant (45.7 versus 44.2 pg/ml, P=0.07 for 1,25[OH]2D; 47.6 versus 45.1 pg/ml, P=0.08 for FGF23). However, after adjusting for body mass index, diet, plasma factors, and other covariates, the odds ratios of incident symptomatic kidney stones in the highest compared with lowest quartiles were 1.73 (95% confidence interval, 1.11 to 2.71; P for trend 0.01) for 1,25(OH)2D and 1.45 (95% confidence interval, 0.96 to 2.19; P for trend 0.03) for FGF23. There were no significant associations between other plasma factors and kidney stone risk. Higher plasma 1,25(OH)2D, even in ranges considered normal, is independently associated with higher risk of symptomatic kidney stones. Although of borderline statistical significance, these findings also suggest that higher FGF23 may be associated with risk. Copyright © 2015 by the American Society of Nephrology.

MIH supplementation strategies: prospective clinical and laboratory trial.

PubMed

Baroni, C; Marchionni, S

2011-03-01

The use of calcium-phosphate casein on hypomineralized molars (molar incisor hypomineralization, MIH) has been proposed but not clinically investigated. Qualitative and quantitative effects of supplementation with a calcium-phosphate casein product on MIH molars were monitored over a period of three years. Molar replicas, minimally invasive biopsies and their SEM microphotographs, plus ESEM/EDX semi-quantitative peaks of elements present in affected enamel were evaluated. Mineralization, morphology, and porosity appeared markedly improved, with calcium and phosphate levels reaching almost normal levels at three years' follow-up. The hypothesis tested was rejected, since calcium-phosphate casein improved enamel morphology in vivo.

Calcium Intake in Elderly Australian Women Is Inadequate

PubMed Central

Meng, Xingqiong; Kerr, Deborah A.; Zhu, Kun; Devine, Amanda; Solah, Vicky; Binns, Colin W.; Prince, Richard L.

2010-01-01

The role of calcium in the prevention of bone loss in later life has been well established but little data exist on the adequacy of calcium intakes in elderly Australian women. The aim of this study was to compare the dietary intake including calcium of elderly Australian women with the Australian dietary recommendation, and to investigate the prevalence of calcium supplement use in this population. Community-dwelling women aged 70–80 years were randomly recruited using the Electoral Roll for a 2-year protein intervention study in Western Australia. Dietary intake was assessed at baseline by a 3-day weighed food record and analysed for energy, calcium and other nutrients. A total of 218 women were included in the analysis. Mean energy intake was 7,140 ± 1,518 kJ/day and protein provided 19 ± 4% of energy. Mean dietary calcium intake was 852 ± 298 mg/day, which is below Australian recommendations. Less than one quarter of women reported taking calcium supplements and only 3% reported taking vitamin D supplements. Calcium supplements by average provided calcium 122 ± 427 mg/day and when this was taken into account, total calcium intake increased to 955 ± 504 mg/day, which remained 13% lower than the Estimated Average Requirement (EAR, 1,100 mg/day) for women of this age group. The women taking calcium supplements had a higher calcium intake (1501 ± 573 mg) compared with the women on diet alone (813 ± 347 mg). The results of this study indicate that the majority of elderly women were not meeting their calcium requirements from diet alone. In order to achieve the recommended dietary calcium intake, better strategies for promoting increased calcium, from both diet and calcium supplements appears to be needed. PMID:22254072

Low Serum Calcium and Magnesium Levels and Rupture of Intracranial Aneurysms.

PubMed

Can, Anil; Rudy, Robert F; Castro, Victor M; Dligach, Dmitriy; Finan, Sean; Yu, Sheng; Gainer, Vivian; Shadick, Nancy A; Savova, Guergana; Murphy, Shawn; Cai, Tianxi; Weiss, Scott T; Du, Rose

2018-05-29

Both low serum calcium and magnesium levels have been associated with the extent of bleeding in patients with intracerebral hemorrhage, suggesting hypocalcemia- and hypomagnesemia-induced coagulopathy as a possible underlying mechanism. We hypothesized that serum albumin-corrected total calcium and magnesium levels are associated with ruptured intracranial aneurysms. The medical records of 4701 patients, including 1201 prospective patients, diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016 were reviewed and analyzed. One thousand two hundred seventy-five patients had available serum calcium, magnesium, and albumin values within 1 day of diagnosis. Individuals were divided into cases with ruptured aneurysms and controls with unruptured aneurysms. Univariable and multivariable logistic regression analyses were performed to determine the association between serum albumin-corrected total calcium and magnesium levels and ruptured aneurysms. In multivariable analysis, both albumin-corrected calcium (odds ratio, 0.33; 95% confidence interval, 0.27-0.40) and magnesium (odds ratio, 0.40; 95% confidence interval, 0.28-0.55) were significantly and inversely associated with ruptured intracranial aneurysms. In this large case-control study, hypocalcemia and hypomagnesemia at diagnosis were significantly associated with ruptured aneurysms. Impaired hemostasis caused by hypocalcemia and hypomagnesemia may explain this association. © 2018 American Heart Association, Inc.

Influence of 2% chlorhexidine on pH, calcium release and setting time of a resinous MTA-based root-end filling material.

PubMed

Jacinto, Rogério Castilho; Linhares-Farina, Giane; Sposito, Otávio da Silva; Zanchi, César Henrique; Cenci, Maximiliano Sérgio

2015-01-01

The addition of chlorhexidine (CHX) to a resinous experimental Mineral Trioxide Aggregate (E-MTA) based root-end filling material is an alternative to boost its antimicrobial activity. However, the influence of chlorhexidine on the properties of this material is unclear. The aim of this study was to evaluate the influence of 2% chlorhexidine on the pH, calcium ion release and setting time of a Bisphenol A Ethoxylate Dimethacrylate/Mineral Trioxide Aggregate (Bis-EMA/MTA) based dual-cure experimental root-end filling material (E-MTA), in comparison with E-MTA without the addition of CHX and with conventional white MTA (W-MTA). The materials were placed in polyethylene tubes, and immersed in deionized water to determine pH (digital pH meter) and calcium ion release (atomic absorption spectrometry technique). The setting time of each material was analyzed using Gilmore needles. The data were statistically analyzed at a significance level of 5%. E-MTA + CHX showed an alkaline pH in the 3 h period of evaluation, the alkalinity of which decreased but remained as such for 15 days. The pH of E-MTA + CHX was higher than the other two materials after 7 days, and lower after 30 days (p < 0.05). All of the materials were found to release calcium ions throughout the 30 days of the study. The addition of CHX increased the calcium ion release of E-MTA to levels statistically similar to W-MTA. E-MTA showed shorter initial and final setting time, compared with W-MTA (p < 0.05). The addition of 2% CHX to MTA prevented setting of the material. The addition of CHX to E-MTA increased its pH and calcium ion release. However, it also prevented setting of the material.

[Effect of 2,3-butanedione monoxime on calcium paradox-induced heart injury in rats].

PubMed

Kong, Ling-Heng; Gu, Xiao-Ming; Su, Xing-Li; Sun, Na; Wei, Ming; Zhu, Juan-Xia; Chang, Pan; Zhou, Jing-Jun

2016-05-01

To investigate the Effect of 2,3-butanedione monoxime (BDM) on calcium paradox-induced heart injury and its underlying mechanisms. Thirty-two adult male SD rats were randomized into 4 groups, namely the control group, BDM treatment control group, calcium paradox group, and BDM treatment group. Isolated Sprague Dawley male rat hearts underwent Langendorff perfusion and the left ventricular pressure (LVP) and left ventricular end-diastolic pressure (LVEDP) were monitored. Left ventricular developed pressure (LVDP) was calculated to evaluate the myocardial performance. Lactate dehydrogenase (LDH) content in the coronary flow was determined. Triphenyltetrazolium chloride staining was used to measure the infarct size, and myocardial cell apoptosis was tested with TUNEL method. Western blotting was used to determine the expression of cleaved caspase-3 and cytochrome c. Compared with the control group, BDM at 20 mmol/L had no effect on cardiac performance, cell death, apoptotic index or the content of LDH, cleaved caspase-3 and cytochrome c at the end of perfusion under control conditions (P>0.05). Calcium paradox treatment significantly decreased the cardiac function and the level of LVDP and induced a larger infarct size (P<0.01), an increased myocardial apoptosis index (P<0.01), and up-regulated expressions of cleaved caspase-3 and cytochrome c (P<0.01). BDM (20 mmol/L) significantly attenuated these effects induced by calcium paradox, and markedly down-regulated the levels of LVEDP and LDH (P<0.01), lowered myocardial apoptosis index, decreased the content of cleaved caspase-3 and cytochrome c (P<0.01), increased LVDP, and reduced the infarct size (P<0.01). BDM suppresses cell apoptosis and contracture and improves heart function and cell survival in rat hearts exposed to calcium paradox, suggesting the value of BDM as an potential drug for myocardial ischemia reperfusion injur.

Polygalacturonase production by calcium alginate immobilized Enterobacter aerogenes NBO2 cells.

PubMed

Darah, I; Nisha, M; Lim, Sheh-Hong

2015-03-01

Bacterial cells of Enterobacter aerogenes NBO2 were entrapped in calcium alginate beads in order to enhance polygalacturonase production compared to free cells. The optimized condition of 5 % (w/v) sodium alginate concentration, agitation speed of 250 rpm, and 15 beads of calcium alginate with inoculum size of 4 % (v/v; 5.4 × 10(7) cells/ml) produced 23.48 U/mL of polygalacturonase compared to free cells of 18.54 U/ml. There was about 26.6 % increment in polygalaturonase production. However, in this study, there was 296.6 % of increment in polygalacturonase production after improvement parameters compared to before improvement parameters of calcium alginate bead immobilization cells (5.92 U/ml). This research has indicated that optimized physical parameters of calcium alginate bead immobilization cells have significantly enhanced the production of polygalacturonase.

Women’s Health Initiative Clinical Trials: Interaction of calcium plus vitamin D and Hormone Therapy

PubMed Central

Robbins, John A; Aragaki, Aaron; Crandall, Carolyn J; Manson, Joann E; Carbone, Laura; Jackson, Rebecca; Lewis, Cora E.; Johnson, Karen C.; Sarto, Gloria; Stefanick, Marcia L; Wactawski-Wende, Jean

2013-01-01

Objective To test the added value of Calcium and vitamin D (CaD) for fracture prevention among women taking postmenopausal hormone therapy (HT). Methods A prospective, partial-factorial design, randomized controlled double blind trial amongst Women’s Health Initiative post-menopausal participants, ages 50–79, at 40 centers in the US, with 7.1 years average follow-up. 27,347 women were randomized to HT (conjugated estrogen 0.625 mg alone, or CEE 0.625 mg daily plus medroxyprogesterone acetate 2.5mg) and 36,282 women randomized to either 1000mg elemental calcium (carbonate) plus 400 IU of vitamin D3 daily each compared to placebo. A total of 16,089 women were in both arms. The predefined outcomes were adjudicated hip fractures and measured bone mineral density. Results Interaction between HT and CaD on hip fracture (P-interaction = 0.01) was shown. The effect of CaD was stronger among women assigned to HT (HR, 0.59; 95%CI, 0.38–0.93) than placebo (HR, 1.20; 95%CI, 0.85, 1.69). The effect of HT on hip fracture was stronger among women assigned to active CaD (HR, 0.43; 0.28–0.66) than placebo (HR, 0.87; 95%CI, 0.60–1.26). CaD supplementation enhanced the anti-fracture effect of the HT at all levels of personal calcium intake. There was no interaction of HT and CaD on change in hip or spine BMD. Conclusions Postmenopausal women at normal risk of hip fracture on HT, supplementation with CaD significantly reduced incident hip fracture beyond HT alone; at all levels of personal baseline total calcium intake. PMID:23799356

Lemon juice has protective activity in a rat urolithiasis model.

PubMed

Touhami, Mohammed; Laroubi, Amine; Elhabazi, Khadija; Loubna, Farouk; Zrara, Ibtissam; Eljahiri, Younes; Oussama, Abdelkhalek; Grases, Félix; Chait, Abderrahman

2007-10-05

The use of herbal medicines (medicinal plants or phytotherapy) has recently gained popularity in Europe and the United States. Nevertheless the exact mechanism of the preventive effects of these products is still far to be clearly established, being its knowledge necessary to successfully apply these therapies to avoid stone formation. The effect of oral lemon juice administration on calcium oxalate urolithiasis was studied in male Wistar rats. Rats were rendered nephrolithic by providing drinking water containing 0.75% ethylene glycol [v/v] (EG) and 2% ammonium chloride [w/v] (AC) for 10 days. In addition to EG/AC treatment, three groups of rats were also gavage-administered solutions containing 100%, 75% or 50% lemon juice [v/v] (6 microl solution/g body weight). Positive control rats were treated with EG/AC but not lemon juice. Negative control rats were provided with normal drinking water, and were administered normal water by gavage. Each group contained 6 rats. After 10 days, serum samples were collected for analysis, the left kidney was removed and assessed for calcium levels using flame spectroscopy, and the right kidney was sectioned for histopathological analysis using light microscopy. Analysis showed that the rats treated with EG/AC alone had higher amounts of calcium in the kidneys compared to negative control rats. This EG/AC-induced increase in kidney calcium levels was inhibited by the administration of lemon juice. Histology showed that rats treated with EG/AC alone had large deposits of calcium oxalate crystals in all parts of the kidney, and that such deposits were not present in rats also treated with either 100% or 75% lemon juice. These data suggest that lemon juice has a protective activity against urolithiasis.

Deoxidation Limits of Titanium Alloys during Pressure Electro Slag Remelting

NASA Astrophysics Data System (ADS)

Bartosinski, M.; Hassan-Pour, S.; Friedrich, B.; Ratiev, S.; Ryabtsev, A.

2016-07-01

This paper focuses on deoxidation of titanium alloys produced by aluminothermic reduction (ATR) and subsequent homogenizing and alloying by vacuum induction melting (VIM). The main goal of the performed research work is to outline the deoxidation limit during pressure electro slag remelting (PESR) of the described material. To obtain electrodes for deoxidation, a Ti-24Al-16V masteralloy was produced by ATR and afterwards melted in a 0.5 litre calcium- zirconate (lab scale) or 14 litres high purity calcia (pilot scale) crucibles with continuous addition of Ti-sponge after reaching liquid state in order to obtain a final Ti-6Al-4V alloy. During melting, in both cases evaporation of calcium was noticed. The cast ingots were analysed for oxygen using inert gas fusion method, matrix and alloying elements were analysed by XRF. Results show oxygen levels between 0.5 and 0.95 wt.-% for the ingots which were melted in calcium-zirconate crucibles and approx. 1 - 1.2 wt.-% for the material produced by utilization of calcia crucibles. The subsequent deoxidation was carried out in lab and pilot scale electroslag remelting furnaces using a commercially pure calcium fluoride slag and metallic calcium as deoxidation agent. It could be shown, that deoxidation of the highly contaminated material is possible applying this method to a certain limit. Pilot scale trials showed a reduction of oxygen contents by 1500 - 3500 ppm. Oxygen levels in lab scale trials showed weaker deoxidation effects. In order to describe the achieved deoxidation effects in a quantitative way, the analyzed oxygen contents of the obtained ingots are compared with calculated data resulting from a mathematical kinetic model. The modelled datasets are in good agreement with experimental oxygen values.

Increased calcium absorption from synthetic stable amorphous calcium carbonate: double-blind randomized crossover clinical trial in postmenopausal women.

PubMed

Vaisman, Nachum; Shaltiel, Galit; Daniely, Michal; Meiron, Oren E; Shechter, Assaf; Abrams, Steven A; Niv, Eva; Shapira, Yami; Sagi, Amir

2014-10-01

Calcium supplementation is a widely recognized strategy for achieving adequate calcium intake. We designed this blinded, randomized, crossover interventional trial to compare the bioavailability of a new stable synthetic amorphous calcium carbonate (ACC) with that of crystalline calcium carbonate (CCC) using the dual stable isotope technique. The study was conducted in the Unit of Clinical Nutrition, Tel Aviv Sourasky Medical Center, Israel. The study population included 15 early postmenopausal women aged 54.9 ± 2.8 (mean ± SD) years with no history of major medical illness or metabolic bone disorder, excess calcium intake, or vitamin D deficiency. Standardized breakfast was followed by randomly provided CCC or ACC capsules containing 192 mg elemental calcium labeled with 44Ca at intervals of at least 3 weeks. After swallowing the capsules, intravenous CaCl2 labeled with 42Ca on was administered on each occasion. Fractional calcium absorption (FCA) of ACC and CCC was calculated from the 24-hour urine collection following calcium administration. The results indicated that FCA of ACC was doubled (± 0.96 SD) on average compared to that of CCC (p < 0.02). The higher absorption of the synthetic stable ACC may serve as a more efficacious way of calcium supplementation. © 2014 American Society for Bone and Mineral Research.

The Content of Structural and Trace Elements in the Knee Joint Tissues.

PubMed

Roczniak, Wojciech; Brodziak-Dopierała, Barbara; Cipora, Elżbieta; Mitko, Krzysztof; Jakóbik-Kolon, Agata; Konieczny, Magdalena; Babuśka-Roczniak, Magdalena

2017-11-23

Many elements are responsible for the balance in bone tissue, including those which constitute a substantial proportion of bone mass, i.e., calcium, phosphorus and magnesium, as well as minor elements such as strontium. In addition, toxic elements acquired via occupational and environmental exposure, e.g., Pb, are included in the basic bone tissue composition. The study objective was to determine the content of strontium, lead, calcium, phosphorus, sodium and magnesium in chosen components of the knee joint, i.e., tibia, femur and meniscus. The levels of Sr, Pb, Ca, P, Na and Mg were the highest in the tibia in both men and women, whereas the lowest in the meniscus. It should be noted that the levels of these elements were by far higher in the tibia and femur as compared to the meniscus. In the components of the knee joint, the level of strontium showed the greatest variation. Significant statistical differences were found between men and women only in the content of lead.

The Content of Structural and Trace Elements in the Knee Joint Tissues

PubMed Central

Roczniak, Wojciech; Brodziak-Dopierała, Barbara; Cipora, Elżbieta; Mitko, Krzysztof; Jakóbik-Kolon, Agata; Konieczny, Magdalena; Babuśka-Roczniak, Magdalena

2017-01-01

Many elements are responsible for the balance in bone tissue, including those which constitute a substantial proportion of bone mass, i.e., calcium, phosphorus and magnesium, as well as minor elements such as strontium. In addition, toxic elements acquired via occupational and environmental exposure, e.g., Pb, are included in the basic bone tissue composition. The study objective was to determine the content of strontium, lead, calcium, phosphorus, sodium and magnesium in chosen components of the knee joint, i.e., tibia, femur and meniscus. The levels of Sr, Pb, Ca, P, Na and Mg were the highest in the tibia in both men and women, whereas the lowest in the meniscus. It should be noted that the levels of these elements were by far higher in the tibia and femur as compared to the meniscus. In the components of the knee joint, the level of strontium showed the greatest variation. Significant statistical differences were found between men and women only in the content of lead. PMID:29168758

ALTERATIONS IN CARDIOMYOCYTE FUNCTION AFTER PULMONARY TREATMENT WITH STAINLESS STEEL WELDING FUME IN RATS

PubMed Central

Popstojanov, Risto; Antonini, James M.; Salmen, Rebecca; Ye, Morgan; Zheng, Wen; Castranova, Vincent; Fekedulegn, Desta B.; Kan, Hong

2015-01-01

Welding fume is composed of a complex of different metal particulates. Pulmonary exposure to different welding fumes may exert a negative impact on cardiac function, although the underlying mechanisms remain unclear. To explore the effect of welding fumes on cardiac function, Sprague-Dawley rats were exposed by intratracheal instillation to 2 mg/rat of manual metal arc hard surfacing welding fume (MMA-HS) once per week for 7 wk. Control rats received saline. Cardiomyocytes were isolated enzymatically at d 1 and 7 postexposure. Intracellular calcium ([Ca2+]i) transients (fluorescence ratio) were measured on the stage of an inverted phase-contrast microscope using a myocyte calcium imaging/cell length system. Phosphorylation levels of cardiac troponin I (cTnI) were determined by Western blot. The levels of nonspecific inflammatory marker C-reactive protein (CRP) and proinflammatory cytokine interleukin-6 (IL-6) in serum were measured by enzyme-linked immunosorbent assay (ELISA). Contraction of isolated cardiomyocytes was significantly reduced at d 1 and d 7 postexposure. Intracellular calcium levels were decreased in response to extracellular calcium stimulation at d 7 postexposure. Changes of intracellular calcium levels after isoprenaline hydrochloride (ISO) stimulation were not markedly different between groups at either time point. Phosphorylation levels of cTnI in the left ventricle were significantly lower at d 1 post-exposure. The serum levels of CRP were not markedly different between groups at either time point. Serum levels of IL-6 were not detectable in both groups. Cardiomyocyte alterations observed after welding fume treatment were mainly due to alterations in intracellular calcium handling and phosphorylation levels of cTnI. PMID:24786677

Alterations in cardiomyocyte function after pulmonary treatment with stainless steel welding fume in rats.

PubMed

Popstojanov, Risto; Antonini, James M; Salmen, Rebecca; Ye, Morgan; Zheng, Wen; Castranova, Vincent; Fekedulegn, Desta B; Kan, Hong

2014-01-01

Welding fume is composed of a complex of different metal particulates. Pulmonary exposure to different welding fumes may exert a negative impact on cardiac function, although the underlying mechanisms remain unclear. To explore the effect of welding fumes on cardiac function, Sprague-Dawley rats were exposed by intratracheal instillation to 2 mg/rat of manual metal arc hard surfacing welding fume (MMA-HS) once per week for 7 wk. Control rats received saline. Cardiomyocytes were isolated enzymatically at d 1 and 7 postexposure. Intracellular calcium ([Ca(2+)]i) transients (fluorescence ratio) were measured on the stage of an inverted phase-contrast microscope using a myocyte calcium imaging/cell length system. Phosphorylation levels of cardiac troponin I (cTnI) were determined by Western blot. The levels of nonspecific inflammatory marker C-reactive protein (CRP) and proinflammatory cytokine interleukin-6 (IL-6) in serum were measured by enzyme-linked immunosorbent assay (ELISA). Contraction of isolated cardiomyocytes was significantly reduced at d 1 and d 7 postexposure. Intracellular calcium levels were decreased in response to extracellular calcium stimulation at d 7 postexposure. Changes of intracellular calcium levels after isoprenaline hydrochloride (ISO) stimulation were not markedly different between groups at either time point. Phosphorylation levels of cTnI in the left ventricle were significantly lower at d 1 postexposure. The serum levels of CRP were not markedly different between groups at either time point. Serum levels of IL-6 were not detectable in both groups. Cardiomyocyte alterations observed after welding fume treatment were mainly due to alterations in intracellular calcium handling and phosphorylation levels of cTnI.

Dietary calcium and vitamin D intake in an adult Middle Eastern population: food sources and relation to lifestyle and PTH.

PubMed

Gannagé-Yared, Marie-Hélène; Chemali, Rana; Sfeir, Cynthia; Maalouf, Ghassan; Halaby, Georges

2005-07-01

Little is known about calcium and vitamin D intakes in Middle Eastern countries, where the prevalence of hypovitaminosis D is high. This study identifies major sources of calcium and vitamin D in the Lebanese diet, examines lifestyle factors that may influence intake of these nutrients and investigates the relationship between nutritional or lifestyle factors and parathyroid hormone (PTH). Three hundred sixteen young healthy volunteers aged 30 to 50 (men, non-veiled and veiled women) were recruited from different rural and urban Lebanese community centers. Food frequency questionnaire was used to evaluate the consumption of vitamin D and calcium-rich foods. We also measured serum PTH levels. Mean daily calcium and vitamin D intake were respectively 683.8 +/- 281.2 mg and 100.6 +/- 71.0 IU. Daily vitamin D sources were divided as follows: 30.4 +/- 46.4 IU from milk and dairy products, 28.2 +/- 26.3 IU from meat and poultry, 25.8 +/- 25 IU from fish, 8.5 +/- 8.6 IU from eggs, and 7.8 +/- 14.3 IU from sweets (respectively 30.2%, 28%, 25.6%, 8.4% and 7.7% of the total vitamin D intake). Mean daily calcium from animal and vegetable sources were respectively 376.3 +/- 233.6 mg and 307.9 +/- 118.5 mg. Animal/total calcium intake ratio was 52% and was only statistically significantly higher in urban people compared to rural ones. Multivariate analysis showed that male sex and urban residence were independent predictors of both vitamin D and calcium intakes (p < 0.01 and p < 0.01 respectively). In addition, veiling was an independent predictor of low vitamin D intake (p < 0.05) and a high body mass index (BMI) was an independent predictor of low calcium intake (p < 0.05). Finally, PTH was inversely correlated with vitamin D intake and the animal/total calcium intake ratio (r = -0.18 and r = -0.22, p < 0.01), while no significant results were achieved for the vegetable calcium. In a multivariate model, urban living, female gender, low vitamin D and calcium intakes, low animal/total calcium intake ratio, and high BMI, are independent predictors of hyperparathyroidism. The deficient nutritional status of vitamin D and calcium in Lebanon justify the implementation of dietary public health measures. People at most risk for secondary hyperparathyroidism should be advised to increase their dietary calcium (mostly animal calcium) and vitamin D, to take supplements, or to increase their sun exposure.

Using Calcium Isotopic Composition of Calcium Carbonate Veins to Assess the Roles of Vein Formation and Seafloor Alteration in Regulation of the Carbon Cycle

NASA Astrophysics Data System (ADS)

Chen, F.; Coggon, R. M.; Teagle, D. A. H.; Turchyn, A. V.

2016-12-01

Calcium carbonate vein formation in the oceanic crust has been proposed as a climate-sensitive feedback mechanism that regulates the carbon cycle on million-year timescales. The suggestion has been that higher pCO2 levels may drive changes in ocean temperature and pH that increase seafloor alteration, releasing more calcium from oceanic basalt. This results in more removal of carbon from Earth's surface through calcium carbonate formation, which includes calcium carbonate vein formation in oceanic crust. The importance of this feedback mechanism remains enigmatic. Measurements of the δ44Ca of calcium carbonate veins in the oceanic crust may constrain the sources of calcium and timing of vein formation. Seawater and basalt are the only sources present shortly after crustal formation, whereas other sources, such as anhydrite dissolution and sedimentary carbonates become available when the crust ages, at which point carbonate veins may form far from the ridge axis. We report the calcium isotopic composition of 65 calcium carbonate veins, ranging from 108 to 1.2 million years old, in hydrothermally altered basalt from the Mid-Atlantic and Juan de Fuca ridges. We also present 43 δ44Ca measurements of 5.9 million year old basalts and dikes from the Costa Rica Rift that have undergone hydrothermal alteration over a range of conditions in upper crust. The δ44Ca of the calcium carbonate veins ranges from -1.59 to 1.01‰ (versus Bulk Silicate Earth), whereas the δ44Ca of altered basalts ranges from -0.18 to 0.28‰. Depth and temperature of formation seem to be major influences on calcium carbonate vein δ44Ca, with veins formed at cool, shallower depths having higher δ44Ca, closer to seawater. In contrast, we note no temporal variation in δ44Ca of calcium carbonate veins when comparing samples from older and younger crust. The majority of veins (54 out of 65) have δ44Ca between that of seawater and basalt, which implies that they may have formed quite soon after crustal formation before other sources of calcium became available. We conclude that calcium carbonate vein formation may derive a significant fraction of calcium from seafloor alteration of basalts. This may cause rates of carbonate vein formation to be sensitive to aspects of ocean chemistry that vary due to changing climate conditions.

Effects of isoflurane anesthesia on ensemble patterns of Ca2+ activity in mouse v1: reduced direction selectivity independent of increased correlations in cellular activity.

PubMed

Goltstein, Pieter M; Montijn, Jorrit S; Pennartz, Cyriel M A

2015-01-01

Anesthesia affects brain activity at the molecular, neuronal and network level, but it is not well-understood how tuning properties of sensory neurons and network connectivity change under its influence. Using in vivo two-photon calcium imaging we matched neuron identity across episodes of wakefulness and anesthesia in the same mouse and recorded spontaneous and visually evoked activity patterns of neuronal ensembles in these two states. Correlations in spontaneous patterns of calcium activity between pairs of neurons were increased under anesthesia. While orientation selectivity remained unaffected by anesthesia, this treatment reduced direction selectivity, which was attributable to an increased response to the null-direction. As compared to anesthesia, populations of V1 neurons coded more mutual information on opposite stimulus directions during wakefulness, whereas information on stimulus orientation differences was lower. Increases in correlations of calcium activity during visual stimulation were correlated with poorer population coding, which raised the hypothesis that the anesthesia-induced increase in correlations may be causal to degrading directional coding. Visual stimulation under anesthesia, however, decorrelated ongoing activity patterns to a level comparable to wakefulness. Because visual stimulation thus appears to 'break' the strength of pairwise correlations normally found in spontaneous activity under anesthesia, the changes in correlational structure cannot explain the awake-anesthesia difference in direction coding. The population-wide decrease in coding for stimulus direction thus occurs independently of anesthesia-induced increments in correlations of spontaneous activity.

Effects of Isoflurane Anesthesia on Ensemble Patterns of Ca2+ Activity in Mouse V1: Reduced Direction Selectivity Independent of Increased Correlations in Cellular Activity

PubMed Central

Goltstein, Pieter M.; Montijn, Jorrit S.; Pennartz, Cyriel M. A.

2015-01-01

Anesthesia affects brain activity at the molecular, neuronal and network level, but it is not well-understood how tuning properties of sensory neurons and network connectivity change under its influence. Using in vivo two-photon calcium imaging we matched neuron identity across episodes of wakefulness and anesthesia in the same mouse and recorded spontaneous and visually evoked activity patterns of neuronal ensembles in these two states. Correlations in spontaneous patterns of calcium activity between pairs of neurons were increased under anesthesia. While orientation selectivity remained unaffected by anesthesia, this treatment reduced direction selectivity, which was attributable to an increased response to the null-direction. As compared to anesthesia, populations of V1 neurons coded more mutual information on opposite stimulus directions during wakefulness, whereas information on stimulus orientation differences was lower. Increases in correlations of calcium activity during visual stimulation were correlated with poorer population coding, which raised the hypothesis that the anesthesia-induced increase in correlations may be causal to degrading directional coding. Visual stimulation under anesthesia, however, decorrelated ongoing activity patterns to a level comparable to wakefulness. Because visual stimulation thus appears to ‘break’ the strength of pairwise correlations normally found in spontaneous activity under anesthesia, the changes in correlational structure cannot explain the awake-anesthesia difference in direction coding. The population-wide decrease in coding for stimulus direction thus occurs independently of anesthesia-induced increments in correlations of spontaneous activity. PMID:25706867

Effects of NaCl and CaCl2 on Water Transport across Root Cells of Maize (Zea mays L.) Seedlings 1

PubMed Central

Azaizeh, Hassan; Gunse, Benito; Steudle, Ernst

1992-01-01

The effect of salinity and calcium levels on water flows and on hydraulic parameters of individual cortical cells of excised roots of young maize (Zea mays L. cv Halamish) plants have been measured using the cell pressure probe. Maize seedlings were grown in one-third strength Hoagland solution modified by additions of NaCl and/or extra calcium so that the seedlings received one of four treatments: control; +100 millimolar NaCl; +10 millimolar CaCl2; +100 millimolar NaCl + 10 millimolar CaCl2. From the hydrostatic and osmotic relaxations of turgor, the hydraulic conductivity (Lp) and the reflection coefficient (σs) of cortical cells of different root layers were determined. Mean Lp values in the different layers (first to third, fourth to sixth, seventh to ninth) of the four different treatments ranged from 11.8 to 14.5 (Control), 2.5 to 3.8 (+NaCl), 6.9 to 8.7 (+CaCl2), and 6.6 to 7.2 · 10−7 meter per second per megapascal (+NaCl + CaCl2). These results indicate that salinization of the growth media at regular calcium levels (0.5 millimolar) decreased Lp significantly (three to six times). The addition of extra calcium (10 millimolar) to the salinized media produced compensating effects. Mean cell σs values of NaCl ranged from 1.08 to 1.16, 1.15 to 1.22, 0.94 to 1.00, and 1.32 to 1.46 in different root cell layers of the four different treatments, respectively. Some of these σs values were probably overestimated due to an underestimation of the elastic modulus of cells, σs values of close to unity were in line with the fact that root cell membranes were practically not permeable to NaCl. However, the root cylinder exhibited some permeability to NaCl as was demonstrated by the root pressure probe measurements that resulted in σsr of less than unity. Compared with the controls, salinity and calcium increased the root cell diameter. Salinized seedlings grown at regular calcium levels resulted in shorter cell length compared with control (by a factor of 2). The results demonstrate that NaCl has adverse effects on water transport parameters of root cells. Extra calcium could, in part, compensate for these effects. The data suggest a considerable apoplasmic water flow in the root cortex. However, the cell-to-cell path also contributed to the overall water transport in maize roots and appeared to be responsible for the decrease in root hydraulic conductivity reported earlier (Azaizeh H, Steudle E [1991] Plant Physiol 97: 1136-1145). Accordingly, the effect of high salinity on the cell Lp was much larger than that on root Lpr. PMID:16669016

L-type calcium channels refine the neural population code of sound level

PubMed Central

Grimsley, Calum Alex; Green, David Brian

2016-01-01

The coding of sound level by ensembles of neurons improves the accuracy with which listeners identify how loud a sound is. In the auditory system, the rate at which neurons fire in response to changes in sound level is shaped by local networks. Voltage-gated conductances alter local output by regulating neuronal firing, but their role in modulating responses to sound level is unclear. We tested the effects of L-type calcium channels (CaL: CaV1.1–1.4) on sound-level coding in the central nucleus of the inferior colliculus (ICC) in the auditory midbrain. We characterized the contribution of CaL to the total calcium current in brain slices and then examined its effects on rate-level functions (RLFs) in vivo using single-unit recordings in awake mice. CaL is a high-threshold current and comprises ∼50% of the total calcium current in ICC neurons. In vivo, CaL activates at sound levels that evoke high firing rates. In RLFs that increase monotonically with sound level, CaL boosts spike rates at high sound levels and increases the maximum firing rate achieved. In different populations of RLFs that change nonmonotonically with sound level, CaL either suppresses or enhances firing at sound levels that evoke maximum firing. CaL multiplies the gain of monotonic RLFs with dynamic range and divides the gain of nonmonotonic RLFs with the width of the RLF. These results suggest that a single broad class of calcium channels activates enhancing and suppressing local circuits to regulate the sensitivity of neuronal populations to sound level. PMID:27605536

Comparative effect of soy protein, soy isoflavones, and 17beta-estradiol on bone metabolism in adult ovariectomized rats.

PubMed

Cai, David J; Zhao, Yongdong; Glasier, Jennifer; Cullen, Diane; Barnes, Stephen; Turner, Charles H; Wastney, Meryl; Weaver, Connie M

2005-05-01

This study provided a comprehensive investigation on the effect of soy protein and soy isoflavones on both calcium and bone metabolism in virgin adult rats. The measurements included bone histology, calcium kinetic modeling, calcium balance, bone densitometry, and whole body densitometry. Results confirmed the bone-preserving effect of estrogen but did not support a bone-sparing role of soy isoflavones. Several animal and short-term human studies have indicated that soy protein isolate enriched with isoflavones may be used as an alternative therapy to estrogen replacement therapy. However, none of the previous studies have investigated this estrogenic effect on both calcium and bone metabolism in animals or humans, which is essential in ascertaining the mode of action of isoflavones. This study was designed to determine the effects of soy protein versus isoflavones on calcium and bone metabolism in an ovariectomized rat model. Unmated 6-month-old ovariectomized and sham-operated female Sprague-Dawley rats were randomly assigned to nine groups (16 rats/group) and pair-fed soy- or casein-based diets with or without isoflavones for 8 weeks. A reference group was administered estrogen through subcutaneous implants (20-35 pg/liter plasma). Bone densitometry, histomorphometry, and mechanical testing were used to study bone metabolism and quality. Calcium metabolism was studied using calcium tracer balance and kinetics. After ovariectomy, estrogen prevented bone loss in trabecular bone and suppressed formation on both trabecular and cortical bone surfaces. Isoflavones given as enriched soy protein isolate or supplements did not prevent trabecular bone loss. Combining isoflavones with estrogen had no additional benefits over estrogen alone. There were no differences in response to isoflavones caused by protein source. None of the treatments significantly affected either total Ca balance or (45)Ca absorption. However, soy protein showed significant effects on reducing urinary loss of Ca in animals, irrespective of isoflavone level, perhaps because of the lower amount of sulfur-containing amino acids in soy protein. Estrogen, but not isoflavones at the levels tested, suppressed bone remodeling in both trabecular and cortical bone after ovariectomy.

Endocrine effects of the tyrosine kinase inhibitor vandetanib in patients treated for thyroid cancer.

PubMed

Brassard, Maryse; Neraud, Barbara; Trabado, Séverine; Salenave, Sylvie; Brailly-Tabard, Sylvie; Borget, Isabelle; Baudin, Eric; Leboulleux, Sophie; Chanson, Philippe; Schlumberger, Martin; Young, Jacques

2011-09-01

The purpose of the study was to assess the endocrine effects of vandetanib, a multikinase inhibitor targeting RET, vascular endothelial growth factor receptor, and epidermal growth factor receptor, in 39 patients with progressive thyroid cancer included in two randomized placebo-controlled trials using vandetanib 300 mg/d. Endocrine samplings were performed at baseline and then every 6 months. We compared differences in endocrine parameters between baseline and on vandetanib therapy or placebo. During vandetanib treatment, several changes were observed. 1) Calcium (P = 0.0004) and vitamin D (P = 0.001) mean replacement doses were increased; calcium level remained unchanged, but serum 25(OH) vitamin D level decreased (P = 0.001); and serum PTH (P = 0.01) and 1,25(OH)(2) vitamin D (P = 0.01) levels increased, suggesting a decreased intestinal absorption of vitamin D or lack of sun exposure as a result of photosensitization. 2) l-T(4) doses were increased (P < 0.0001) to maintain serum TSH within the normal range. 3) In male patients, total testosterone (P = 0.048), bioavailable testosterone (P = 0.03), and SHBG (P = 0.02) levels increased. Serum inhibin B decreased (P = 0.02) and stimulated FSH increased (P = 0.006), suggesting a Sertoli cells insufficiency. 4) Cortisol level increased (P = 0.007) as well as ACTH level (P = 0.03) and cortisol-binding globulin (P = 0.02), but free urinary cortisol levels remained in the normal range. None of these changes were observed in patients randomized to the placebo arm. In patients with locally advanced or metastatic thyroid cancer, the tyrosine kinase inhibitor vandetanib has several endocrine effects. Thyroid hormone, calcium, and vitamin D analog requirements increased, but consequences of the biological alterations on phosphocalcic metabolism and gonadotrope and adrenal functions are unknown.

High dietary calcium intake does not counteract disuse-induced bone loss

NASA Astrophysics Data System (ADS)

Baecker, N.; Boese, A.; Smith, S. M.; Heer, M.

Reduction of mechanical stress on bone inhibits osteoblast-mediated bone formation, increases osteoclast-mediated bone resorption, and leads to what has been called disuse osteoporosis. Prolonged therapeutic bed rest, immobilization and space flight are common causes of disuse osteoporosis. There are sufficient data supporting the use of calcium in combination with vitamin D in the prevention and treatment of postmenopausal osteoporosis. In our study we examined the potential of high dietary calcium intake as a nutrition therapy for disuse-induced bone loss during head-down bed rest in healthy young men. In 2 identical metabolic ward, head-down bed rest (HDBR) experiments (crossover design), we studied the effect of high dietary calcium intake (2000 mg/d) in comparison to the recommended calcium intake of 1000 mg/d on markers of bone turnover. Experiment A (EA) was a 6-day randomized, controlled HDBR study. Experiment B (EB) was a 14-day randomized, controlled HDBR study. In both experiments, the test subjects stayed under well-controlled environmental conditions in our metabolic ward. Subjects' diets in the relevant study phases (HDBR versus Ambulatory Control) of EA and EB were identical except for the calcium intake. The subjects obtained 2000 mg/d Calcium in EA and 2000 mg/d in EB. Blood was drawn at baseline, before entering the relevant intervention period, on day 5 in study EA, and on days 6, 11 and 14 in study EB. Serum calcium, bone formation markers - Procollagen-I-C-Propeptide (PICP) and bone alkaline phosphatase (bAP) were analyzed in serum. 24h-urine was collected throughout the studies for determination of the excretion of calcium (UCaV) and a bone resorption marker, C-terminal telopeptide of collagen type I (UCTX). In both studies, serum calcium levels were unchanged. PICP tended to decrease in EA (p=0.08). In EB PICP decreased significantly over time (p=0.003) in both the control and HDBR periods, and tended to further decrease in the HDBR period (p=0.06). While HDBR did not affect bAP in both EA and EB, bAP decreased significantly over time in both groups of EB (p<0.001). UCaV significantly increased during HDBR in EA (p=0.002) and EB (p=0.004) compared to the ambulatory controls. UCTX significantly increased on the second day of HDBR by 18% (p<0.001) in EA and by 27% (p=0.03) in EB. We conclude from these results that doubling dietary calcium intake from the recommended level of 1000 mg/d to 2000 mg/d does not prevent the decrease in bone formation activity and the increase of bone resorption activity in disuse-induced bone loss.

Meals and dephytinization affect calcium and zinc absorption in Nigerian children with rickets

USDA-ARS?s Scientific Manuscript database

Nutritional rickets resulting from calcium insufficiency is common in Nigeria, and high dietary phytate is thought to inhibit calcium and zinc absorption. We compared the effects of a high-phytate meal and enzymatic dephytinization on calcium and zinc absorption in Nigerian children with and without...

[Effect of intensive pretreatment with atorvastatin calcium on outcomes of percutaneous coronary intervention in elderly patients with coronary heart disease].

PubMed

Guo, Xiaoyan; Huang, Xuecheng; Wang, Qiwu

2015-02-01

To observe the effects of different loading doses of atorvastatin calcium on the outcomes of percutaneous coronary intervention (PCI) in elderly patients with coronary heart disease (CHD). A total of 120 CHD patients aged over 80 years were randomly assigned into 3 equal groups to receive intensive pretreatment with statin at the doses of 20, 40, or 60 mg prior to PCI performed within 48 to 72 h after admission. The changes of postoperative cardiac biochemical markers including creatine kinase isoenzyme (CKMB), troponin I (cTNI) and high-sensitivity c-reactive protein (hs-CRP) were observed and the incidence of major adverse cardiac events (MACE, including cardiac death, myocardial infarction, and target vessel revascularization) were recorded within 30 days after PCI. Thirty-four patients in 20 mg statin group, 40 in 40 mg statin group, and 38 in 60 mg statin group completed this study. In all the 3 groups, hs-CRP level significantly increased at 12 and 24 h after PCI compared with the preoperative levels (P<0.05). The patients in 60 mg statin group showed significantly lower levels of CKMB, cTNI, and hs-CRP at 24 h after PCI than those in 20 mg statin group (P<0.05), and had also a significantly lower incidence of total MACE within 30 days after PCI (2.6% vs 26.5%, P=0.003) resulting primarily from significantly reduced myocardial infarction associated with PCI (2.6% vs 20.6%, P=0.016). The adverse drug reactions were comparable among the 3 groups (P>0.05). Intensive pretreatment with 60 mg/day atorvastatin calcium can significantly reduce myocardial infarction related to PCI with good safety in elderly patients with CHD.

Comparison of side effects of pentagastrin test and calcium stimulation test in patients with increased basal calcitonin concentration: the gender-specific differences.

PubMed

Ubl, Philipp; Gincu, Tatiana; Keilani, Mohammad; Ponhold, Lothar; Crevenna, Richard; Niederle, Bruno; Hacker, Marcus; Li, Shuren

2014-08-01

The aim of this study was to compare the side effects of the pentagastrin test and the calcium stimulation test in patients with increased basal calcitonin concentration, especially the gender-specific differences of side effects. A total of 256 patients (123 females and 133 males, mean age of 56 ± 27 years, range 21-83 years) had both pentagastrin and calcium stimulation tests. All patients filled in a questionnaire regarding the side effects within 30 min after completion of the stimulation tests. The differences of side effects between female and male patients as well as between the pentagastrin stimulation test and the calcium stimulation test were evaluated. Warmth feeling was the most frequent occurring side effect in all patients who had both pentagastrin and calcium stimulation tests, followed by nausea, altered gustatory sensation, and dizziness. The incidences of urgency to micturate (p < 0.05) and dizziness (p < 0.05) were significantly increased in the female patients as compared to male patients by calcium stimulation test. Significant higher incidences of urgency to micturate (p < 0.05) and warmth feeling (p < 0.05) were found by calcium stimulation test as compared with those by pentagastrin test in female patients. The incidences of nausea (p < 0.05) and abdominal cramping (p < 0.05) in male patients were significantly higher by pentagastrin stimulation test than by calcium stimulation test. There is a significant gender-specific difference in side effects induced by calcium stimulation test. Female patients have fewer side effects by pentagastrin test than by calcium stimulation test. Male patients may tolerate the calcium stimulation test better than the pentagastrin test.

Serum calcium and incident diabetes: an observational study and meta-analysis.

PubMed

Sing, C W; Cheng, V K F; Ho, D K C; Kung, A W C; Cheung, B M Y; Wong, I C K; Tan, K C B; Salas-Salvadó, J; Becerra-Tomas, N; Cheung, C L

2016-05-01

The study aimed to prospectively evaluate if serum calcium is related to diabetes incidence in Hong Kong Chinese. The results showed that serum calcium has a significant association with increased risk of diabetes. The result of meta-analysis reinforced our findings. This study aimed to evaluate the association of serum calcium, including serum total calcium and albumin-corrected calcium, with incident diabetes in Hong Kong Chinese. We conducted a retrospective cohort study in 6096 participants aged 20 or above and free of diabetes at baseline. Serum calcium was measured at baseline. Incident diabetes was determined from several electronic databases. We also searched relevant databases for studies on serum calcium and incident diabetes and conducted a meta-analysis using fixed-effect modeling. During 59,130.9 person-years of follow-up, 631 participants developed diabetes. Serum total calcium and albumin-corrected calcium were associated with incident diabetes in the unadjusted model. After adjusting for demographic and clinical variables, the association remained significant only for serum total calcium (hazard ratio (HR), 1.32 (95 % confidence interval (CI), 1.02-1.70), highest vs. lowest quartile). In a meta-analysis of four studies including the current study, both serum total calcium (pooled risk ratio (RR), 1.38 (95 % CI, 1.15-1.65); I (2) = 5 %, comparing extreme quantiles) and albumin-corrected calcium (pooled RR, 1.29 (95 % CI, 1.03-1.61); I (2) = 0 %, comparing extreme quantiles) were associated with incident diabetes. Penalized regression splines showed that the association of incident diabetes with serum total calcium and albumin-correlated calcium was non-linear and linear, respectively. Elevated serum calcium concentration is associated with incident diabetes. The mechanism underlying this association warrants further investigation.

A comparative study of calcium absorption following a single serving administration of calcium carbonate powder versus calcium citrate tablets in healthy premenopausal women

PubMed Central

Wang, Haiyuan; Bua, Peter; Capodice, Jillian

2014-01-01

Background Calcium is an essential mineral often taken as a daily, long-term nutritional supplement. Data suggests that once-daily dosing is important with regard to long-term compliance of both drugs and nutritional supplements. Objective This study was undertaken to compare the bioavailability of a single serving of two calcium supplements in healthy, premenopausal women. Design A two-period, crossover bioavailability study of a single serving of calcium citrate tablets (two tablets=500 mg calcium) versus a single serving of calcium carbonate powder (one packet of powder=1,000 mg calcium) was performed in healthy women aged between 25 and 45. All subjects were on a calcium-restricted diet 7 days prior to testing and fasted for 12 h before being evaluated at 0, 1, 2, and 4 h after oral administration of the test agents. Blood measurements for total and ionized calcium and parathyroid hormone were performed and adverse events were monitored. Results Twenty-three women were evaluable with a mean age of 33.2±8.71. Results showed that administration of a single serving of a calcium carbonate powder resulted in greater absorption in total and ionized calcium versus a single serving of calcium citrate tablets at 4 h (4.25±0.21 vs. 4.16±0.16, p=0.001). There were minimal side effects and no reported serious adverse events. Conclusions This study shows that a single serving of a calcium carbonate powder is more bioavailable than a single serving of calcium citrate tablets. This may be beneficial for long-term compliance. PMID:24772062

Evolution of a Lowland Karst Landscape; A Mass-Balance Approach

NASA Astrophysics Data System (ADS)

Chamberlin, C.; Heffernan, J. B.; Cohen, M. J.; Quintero, C.; Pain, A.

2016-12-01

Karst landscapes are highly soluble, and are vulnerable to biological acid production as a major driving factor in their evolution. Big Cypress National Park (BICY) is a low-lying karst landscape in southern Florida displaying a distinctive morphology of isolated depressions likely influenced by biology. The goal of this study is to constrain timescales of landform development in BICY. This question was addressed through the construction of landscape-scale elemental budgets for both calcium and phosphorus. Precipitation and export fluxes were calculated using available chemistry and hydrology data, and stocks were calculated from a combination of existing data, field measurements, and laboratory chemical analysis. Estimates of expected mass export given no biological acid production and given an equivalent production of 100% of GPP were compared with observed rates. Current standing stocks of phosphorus are dominated by a large soil pool, and contain 500 Gg P. Inputs are largely dominated by precipitation, and 8000 years are necessary to accumulate standing stocks of phosphorus given modern fluxes. Calcium flux is vastly dominated by dissolution of the limestone bedrock, and though some calcium is retained in the soil, most is exported. Using LiDAR generated estimates of volume loss across the landscape and current export rates, an estimated 15,000 years would be necessary to create the modern landscape. Both of these estimates indicate that the BICY landscape is geologically very young. The different behaviors of these elements (calcium is largely exported, while phosphorus is largely retained) lend additional confidence to estimates of denudation rates of the landscape. These estimates can be even closer reconciled if calcium redistribution over the landscape is allowed for. This estimate is compared to the two bounding conditions for biological weathering to indicate a likely level of biological importance to landscape development in this system.

Dysregulation of cellular calcium homeostasis in Alzheimer's disease: bad genes and bad habits.

PubMed

Mattson, M P; Chan, S L

2001-10-01

Calcium is one of the most important intracellular messengers in the brain, being essential for neuronal development, synaptic transmission and plasticity, and the regulation of various metabolic pathways. The findings reviewed in the present article suggest that calcium also plays a prominent role in the pathogenesis of Alzheimer's disease (AD). Associations between the pathological hallmarks ofAD (neurofibrillary tangles [NFT] and amyloid plaques) and perturbed cellular calcium homeostasis have been established in studies of patients, and in animal and cell culture models of AD. Studies of the effects of mutations in the beta-amyloid precursor protein (APP) and presenilins on neuronal plasticity and survival have provided insight into the molecular cascades that result in synaptic dysfunction and neuronal degeneration in AD. Central to the neurodegenerative process is the inability of neurons to properly regulate intracellular calcium levels. Increased levels of amyloid beta-peptide (Abeta) induce oxidative stress, which impairs cellular ion homeostasis and energy metabolism and renders neurons vulnerable to apoptosis and excitotoxicity. Subtoxic levels of Abeta may induce synaptic dysfunction by impairing multiple signal transduction pathways. Presenilin mutations perturb calcium homeostasis in the endoplasmic reticulum in a way that sensitizes neurons to apoptosis and excitotoxicity; links between aberrant calcium regulation and altered APP processing are emerging. Environmental risk factors for AD are being identified and may include high calorie diets, folic acid insufficiency, and a low level of intellectual activity (bad habits); in each case, the environmental factor impacts on neuronal calcium homeostasis. Low calorie diets and intellectual activity may guard against AD by stimulating production of neurotrophic factors and chaperone proteins. The emerging picture of the cell and molecular biology of AD is revealing novel preventative and therapeutic strategies for eradicating this growing epidemic of the elderly.

Coronary artery calcium: a multi-institutional, multimanufacturer international standard for quantification at cardiac CT.

PubMed

McCollough, Cynthia H; Ulzheimer, Stefan; Halliburton, Sandra S; Shanneik, Kaiss; White, Richard D; Kalender, Willi A

2007-05-01

To develop a consensus standard for quantification of coronary artery calcium (CAC). A standard for CAC quantification was developed by a multi-institutional, multimanufacturer international consortium of cardiac radiologists, medical physicists, and industry representatives. This report specifically describes the standardization of scan acquisition and reconstruction parameters, the use of patient size-specific tube current values to achieve a prescribed image noise, and the use of the calcium mass score to eliminate scanner- and patient size-based variations. An anthropomorphic phantom containing calibration inserts and additional phantom rings were used to simulate small, medium-size, and large patients. The three phantoms were scanned by using the recommended protocols for various computed tomography (CT) systems to determine the calibration factors that relate measured CT numbers to calcium hydroxyapatite density and to determine the tube current values that yield comparable noise values. Calculation of the calcium mass score was standardized, and the variance in Agatston, volume, and mass scores was compared among CT systems. Use of the recommended scanning parameters resulted in similar noise for small, medium-size, and large phantoms with all multi-detector row CT scanners. Volume scores had greater interscanner variance than did Agatston and calcium mass scores. Use of a fixed calcium hydroxyapatite density threshold (100 mg/cm(3)), as compared with use of a fixed CT number threshold (130 HU), reduced interscanner variability in Agatston and calcium mass scores. With use of a density segmentation threshold, the calcium mass score had the smallest variance as a function of patient size. Standardized quantification of CAC yielded comparable image noise, spatial resolution, and mass scores among different patient sizes and different CT systems and facilitated reduced radiation dose for small and medium-size patients.

Biomimetic fabrication of a three-level hierarchical calcium phosphate/collagen/hydroxyapatite scaffold for bone tissue engineering.

PubMed

Zhou, Changchun; Ye, Xingjiang; Fan, Yujiang; Ma, Liang; Tan, Yanfei; Qing, Fangzu; Zhang, Xingdong

2014-09-01

A three-level hierarchical calcium phosphate/collagen/hydroxyapatite (CaP/Col/HAp) scaffold for bone tissue engineering was developed using biomimetic synthesis. Porous CaP ceramics were first prepared as substrate materials to mimic the porous bone structure. A second-level Col network was then composited into porous CaP ceramics by vacuum infusion. Finally, a third-level HAp layer was achieved by biomimetic mineralization. The three-level hierarchical biomimetic scaffold was characterized using scanning electron microscopy, energy-dispersive x-ray spectra, x-ray diffraction and Fourier transform infrared spectroscopy, and the mechanical properties of the scaffold were evaluated using dynamic mechanical analysis. The results show that this scaffold exhibits a similar structure and composition to natural bone tissues. Furthermore, this three-level hierarchical biomimetic scaffold showed enhanced mechanical strength compared with pure porous CaP scaffolds. The biocompatibility and osteoinductivity of the biomimetic scaffolds were evaluated using in vitro and in vivo tests. Cell culture results indicated the good biocompatibility of this biomimetic scaffold. Faster and increased bone formation was observed in these scaffolds following a six-month implantation in the dorsal muscles of rabbits, indicating that this biomimetic scaffold exhibits better osteoinductivity than common CaP scaffolds.

[Changes of control of disorders of calcium and phosphorus metabolism in Lithuanian hemodialysis centers 1996-2003].

PubMed

Ziginskiene, Edita; Kuzminskis, Vytautas; Bumblyte, Inga Arūne; Kardauskaite, Zydrūne; Uogintaite, Jurgita

2005-01-01

The aim of the study was to evaluate the changes of the rate of disorders of calcium and phosphorus metabolism and their control in patients on hemodialysis (HD) in Lithuania in 1996-2003. Every December during this period we visited all HD centers of Lithuania and collected data on calcium-phosphorus metabolism in HD patients. 51.8% of HD patients in 1999 and 44.6% in 2003 had hyperphosphatemia (>1.8 mmol/l) (p<0.05). The mean phosphate concentration was 1.82+/-0.56 mmol/l in 2003 (p<0.05, comparing with 1.95+/-0.72 mmol/l in 1999 and 1.9+/-0.72 mmol/l in 2001). 7.1% of HD patients had hypocalcemia in 2003 and 7.8% hypercalcemia. Serum parathyroid hormone level was investigated only in 27.3% of HD patients in 1999 and 84.8% in 2003 (p<0.05). Use of alfacalcidol significantly decreased from 77.5% in 1998 to 29.4% in 2003, when the evaluation of serum parathyroid hormone increased (r=-0.911, p=0.03). Serum parathyroid hormone level was not analyzed for 59.8% of patients who used alfacalcidol and 59.4% of them had hyperphosphatemia in 1999 (6.3% and 32.9% in 2003, respectively; p<0.05). 10.7% of these patients had hypercalcemia in 2003. In summary, the correction of disorders of calcium and phosphorus metabolism in HD patients was insufficient but ameliorative. Monitoring of serum parathyroid hormone increased significantly during 1997-2003. The percentage of the precarious use of alfacalcidol decreased significantly when the evaluation of serum parathyroid hormone level became regular.

Comparative 25-OH-vitamin D level in institutionalized women older than 65 years from two cities in Spain and Argentina having a similar solar radiation index.

PubMed

Portela, María Luz Pita Martin; Mónico, Amália; Barahona, Antonieta; Dupraz, Hernan; Sol Gonzales-Chaves, Macarena Maria; Zeni, Susana Noemi

2010-03-01

The present study evaluated and compared vitamin D nutritional status and calcium-phosphorus metabolism in institutionalized women >65 y from two cities that have a similar sun irradiation index (heliophany). The study was carried out in women living in similar social-status institutions from geographic cities having a similar solar radiation index (Lleida, Spain, n=49, and suburban Buenos Aires, Argentina [BA], n=48) at the end of summer. Fish consumption was higher in the Lleida group, as was red-meat consumption in the BA group. In both groups mean calcium intake was 800 mg/d. The daily intake of vitamin D was higher in the BA group (P<0.001). A total of 90% in Lleida and 86% in BA had 25-hydroxyvitamin D (25OHD) levels <20 ng/mL. A significant inverse correlation between individual 25OHD and parathyroid hormone (PTH) levels was observed in the two groups of women (r=-0.329, P=0.035). PTH levels >100 pg/mL were found in 24% and 20% of women in Lleida and BA, respectively. There was a marked increase in carboxy-terminal telopeptide cross-links of type I collagen levels and a decrease in 25OHD with an increase in PTH levels (P<0.05). Conversely, bone alkaline phosphatase increased significantly only when the PTH concentration duplicated the reference range. Even at the end of summer, vitamin D deficiency/insufficiency was prevalent in the two studied institutionalized elderly women. In the narrow range of the dietary calcium intake (close to 800 mg/d) of both studied groups, secondary hyperparathyroidism was absent when 25OHD levels were >17 ng/dL, indicating changes in the regulation control of serum PTH and consequently the changes in this threshold. As a result, vitamin D deficiency must be reversed to avoid the increment in bone turnover and to ensure the endocrine and paracrine functions of vitamin D for overall health and well-being. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Convergent synthesis of double point modified analogs of 1α,25-dihydroxyvitamin D2 for biological evaluation.

PubMed

Nadkarni, Sharmin; Chodyński, Michał; Krajewski, Krzysztof; Cmoch, Piotr; Marcinkowska, Ewa; Brown, Geoffrey; Kutner, Andrzej

2016-11-01

There is a long lasting controversy over the biological activity of vitamin D 2 as compared to vitamin D 3 in terms of maintaining of calcium homeostasis and raising the level of circulating 25-OH-D. To shed more light on this relationship we synthesized 1α,25-dihydroxyvitamin D 2 , by a novel convergent strategy, to compare this compound directly with the activity of 1α,25-dihydroxyvitamin D 3 . The same synthetic strategy also provided a series of (5E,7E) geometric isomers of the natural 1α,25-dihydroxyvitamin D 2 as well as a series of double point modified analogs of its (24R)-epimer, including C-22 hydroxy derivatives. The structure of the new analogs was determined by 1 H and 13 C NMR as well as by mass spectrometry. The influence of (5E,7E) modification, alone or in combination with additional modifications in the side chain, on the activity profile and metabolic deactivation of analogs of 1α,25-dihydroxyvitamin D 2 still remains unknown. (5E,7E) modification in the structure of new analogs of 1α,25-dihydroxyvitamin D 2 is expected to give analogs with no influence on calcium level, as was previously obtained for the analogs of 1α,25-dihydroxyvitamin D 3 . Investigation of the affinities for the vitamin D receptor and cell differentiation, transcriptional and calcium activities of the most active form of vitamin D 2 and of (5E,7E) analogs, compared to 1α,25-dihydroxyvitamin D 3 , is underway in the collaborating laboratories. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cross Talk among Calcium, Hydrogen Peroxide, and Nitric Oxide and Activation of Gene Expression Involving Calmodulins and Calcium-Dependent Protein Kinases in Ulva compressa Exposed to Copper Excess1[C][W][OA

PubMed Central

González, Alberto; Cabrera, M. de los Ángeles; Henríquez, M. Josefa; Contreras, Rodrigo A.; Morales, Bernardo; Moenne, Alejandra

2012-01-01

To analyze the copper-induced cross talk among calcium, nitric oxide (NO), and hydrogen peroxide (H2O2) and the calcium-dependent activation of gene expression, the marine alga Ulva compressa was treated with the inhibitors of calcium channels, ned-19, ryanodine, and xestospongin C, of chloroplasts and mitochondrial electron transport chains, 3-(3,4-dichlorophenyl)-1,1-dimethylurea and antimycin A, of pyruvate dehydrogenase, moniliformin, of calmodulins, N-(6-aminohexyl)-5-chloro-1-naphtalene sulfonamide, and of calcium-dependent protein kinases, staurosporine, as well as with the scavengers of NO, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, and of H2O2, ascorbate, and exposed to a sublethal concentration of copper (10 μm) for 24 h. The level of NO increased at 2 and 12 h. The first peak was inhibited by ned-19 and 3-(2,3-dichlorophenyl)-1,1-dimethylurea and the second peak by ned-19 and antimycin A, indicating that NO synthesis is dependent on calcium release and occurs in organelles. The level of H2O2 increased at 2, 3, and 12 h and was inhibited by ned-19, ryanodine, xestospongin C, and moniliformin, indicating that H2O2 accumulation is dependent on calcium release and Krebs cycle activity. In addition, pyruvate dehydrogenase, 2-oxoxglutarate dehydrogenase, and isocitrate dehydrogenase activities of the Krebs cycle increased at 2, 3, 12, and/or 14 h, and these increases were inhibited in vitro by EGTA, a calcium chelating agent. Calcium release at 2, 3, and 12 h was inhibited by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and ascorbate, indicating activation by NO and H2O2. In addition, the level of antioxidant protein gene transcripts decreased with N-(6-aminohexyl)-5-chloro-1-naphtalene sulfonamide and staurosporine. Thus, there is a copper-induced cross talk among calcium, H2O2, and NO and a calcium-dependent activation of gene expression involving calmodulins and calcium-dependent protein kinases. PMID:22234999

Cross talk among calcium, hydrogen peroxide, and nitric oxide and activation of gene expression involving calmodulins and calcium-dependent protein kinases in Ulva compressa exposed to copper excess.

PubMed

González, Alberto; Cabrera, M de Los Ángeles; Henríquez, M Josefa; Contreras, Rodrigo A; Morales, Bernardo; Moenne, Alejandra

2012-03-01

To analyze the copper-induced cross talk among calcium, nitric oxide (NO), and hydrogen peroxide (H(2)O(2)) and the calcium-dependent activation of gene expression, the marine alga Ulva compressa was treated with the inhibitors of calcium channels, ned-19, ryanodine, and xestospongin C, of chloroplasts and mitochondrial electron transport chains, 3-(3,4-dichlorophenyl)-1,1-dimethylurea and antimycin A, of pyruvate dehydrogenase, moniliformin, of calmodulins, N-(6-aminohexyl)-5-chloro-1-naphtalene sulfonamide, and of calcium-dependent protein kinases, staurosporine, as well as with the scavengers of NO, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, and of H(2)O(2), ascorbate, and exposed to a sublethal concentration of copper (10 μm) for 24 h. The level of NO increased at 2 and 12 h. The first peak was inhibited by ned-19 and 3-(2,3-dichlorophenyl)-1,1-dimethylurea and the second peak by ned-19 and antimycin A, indicating that NO synthesis is dependent on calcium release and occurs in organelles. The level of H(2)O(2) increased at 2, 3, and 12 h and was inhibited by ned-19, ryanodine, xestospongin C, and moniliformin, indicating that H(2)O(2) accumulation is dependent on calcium release and Krebs cycle activity. In addition, pyruvate dehydrogenase, 2-oxoxglutarate dehydrogenase, and isocitrate dehydrogenase activities of the Krebs cycle increased at 2, 3, 12, and/or 14 h, and these increases were inhibited in vitro by EGTA, a calcium chelating agent. Calcium release at 2, 3, and 12 h was inhibited by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and ascorbate, indicating activation by NO and H(2)O(2). In addition, the level of antioxidant protein gene transcripts decreased with N-(6-aminohexyl)-5-chloro-1-naphtalene sulfonamide and staurosporine. Thus, there is a copper-induced cross talk among calcium, H(2)O(2), and NO and a calcium-dependent activation of gene expression involving calmodulins and calcium-dependent protein kinases.

Hyperoside protects human kidney‑2 cells against oxidative damage induced by oxalic acid.

PubMed

Chen, Yongliang; Ye, Lihong; Li, Wangjian; Li, Dongzhang; Li, Feng

2018-05-02

The majority of renal calculi (kidney stones) are calcium stones. Oxidative damage to renal tubular epithelial cells induced by reactive oxygen species (ROS) is the predominant cause of calcium oxalate stone formation. Hyperoside (Hyp) is a flavonol glycoside extracted from medicinal plants and appears to exhibit potent antioxidant activity in various cells. The aim of the present study was to investigate the protective effect of Hyp on renal cells exposed to oxidative stress simulated by oxalic acid (OA), and to determine whether the underlying mechanism involves the nuclear factor E2‑related factor2 (Nrf2)‑antioxidative response element signaling pathway. The study determined the indicators of high oxidative stress, including ROS and hydrogen peroxide (H2O2) in human kidney‑2 cells and the results demonstrated that the levels of ROS, as evaluated by flow cytometry, and H2O2 were significantly increased following treatment with OA (5 mmol/l) for 24 h (OA group), compared with those in the untreated control group. The increased activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in these cells explained this observation, as it is a major source of ROS. The results demonstrated that, in the OA group, the adhesion of calcium oxalate crystals and lactate dehydrogenase (LDH) were significantly increased, and MTT assay demonstrated that cell viability was inhibited, compared with the control, which indicated that severe injury of cells was induced by OA. However, when the cells were pre‑treated with Hyp prior to treatment with OA (drug group), the levels of ROS and H2O2, and the activities of NADPH oxidase and LD were increased, and the adhesion of calcium oxalate crystals to cells was reduced, compared with the OA group. Western blot analysis and reverse transcription‑quantitative polymerase chain reaction demonstrated that the protein and mRNA expression levels of Nrf2, heme oxygenase‑1 (HO‑1) and NAD(P)H: quinineoxidoreductase 1 (NQO1) in the Hyp groups were significantly increased, compared with those in the OA group, with the exception of Nrf2 mRNA. These results suggested that Hyp had a marked protective effect on renal cells against the oxidative damage and cytotoxicity simulated by OA. This is the first report, to the best of our knowledge, demonstrating that the ability of Hyp to enhance the endogenous functions of antioxidation and detoxification in cells may involve the Nrf2/HO‑1/NQO1 pathway.

Perioperative indicators of hypocalcemia in total thyroidectomy: the role of vitamin D and parathyroid hormone.

PubMed

Salinger, Eric M; Moore, John T

2013-12-01

Hypocalcemia is a common complication of thyroidectomy. The aim of this study was to identify risk factors for this problem. This prospective analysis included 111 patients undergoing total or completion thyroidectomy. Preoperative vitamin D levels and postoperative day 1 parathyroid hormone levels were analyzed for their predictive effects on postoperative hypocalcemia. Patients with ionized calcium <4.4 mg/dL had significantly lower mean parathyroid hormone levels than normocalcemic patients (13.0 vs 28.4 pg/mL, P < .001). Parathyroid hormone levels were also significantly lower in symptomatic patients (11.0 vs 28.4 pg/mL, P < .001). Preoperative vitamin D level, body mass index, gender, and pathologic findings were not associated with low calcium levels or symptoms of hypocalcemia. Younger age and low postoperative parathyroid hormone levels are predictive of symptomatic hypocalcemia. A parathyroid hormone level outside of the reference range may indicate a need for more aggressive postoperative calcium supplementation and treatment with activated vitamin D. Older patients with normal postoperative parathyroid hormone levels may be safely discharged with appropriate calcium supplementation. Copyright © 2013 Elsevier Inc. All rights reserved.

Bioaccessibility of four calcium sources in different whey-based dairy matrices assessed by in vitro digestion.

PubMed

Lorieau, Lucie; Le Roux, Linda; Gaucheron, Frédéric; Ligneul, Amandine; Hazart, Etienne; Dupont, Didier; Floury, Juliane

2018-04-15

Numerous calcium sources are available to enrich food, but their behavior during digestion is still unknown. This study focused on the influence of the gastro-intestinal pH, the food structure and the calcium source on the bioaccessibility of the nutrient. Four calcium sources were studied: calcium carbonate, calcium citrate malate, calcium phosphate and calcium bisglycinate. These were added to dairy matrices, containing cream and whey proteins, of different forms (liquid or gel). The kinetics of solubility and ionic calcium concentration during in vitro digestion were studied, as function of gastro-intestinal pH. All calcium sources were almost fully soluble in the gastric compartment, and then became insoluble in the intestinal phase. The level of calcium insolubilisation in the intestinal phase was not significantly influenced by the matrix structure (liquid or gel), but was more dependent on the calcium source, this effect leading to different final calcium bioaccessibility from 36% to 20%. Copyright © 2017 Elsevier Ltd. All rights reserved.

Regulation of bone mineral loss during lactation

NASA Technical Reports Server (NTRS)

Brommage, R.; Deluca, H. F.

1985-01-01

The effects of varyng dietary calcium and phosphorous levels, vitamin D deficiency, oophorectomy, adrenalectomy, and simultaneous pregnancy on bone mineral loss during lactation in rats are studied. The experimental procedures and evaluations are described. The femur ash weight of lactating and nonlactating rats are calculated. The data reveals that a decrease in dietary calcium of 0.02 percent results in an increased loss of bone mineral, an increase in calcium to 1.4 percent does not lessen bone mineral loss, and bone mineral loss in vitamin D deficient rats is independent of calcium levels. It is observed that changes in dietary phosphorous level, oophorectomy, adrenalectomy, and simultaneous pragnancy do not reduce bone mineral loss during lactation. The analysis of various hormones to determine the mechanism that triggers bone mineral loss during lactation is presented.

Calcium Deficiency of Dark-grown Seedlings of Phaseolus vulgaris L.

PubMed

Helms, K

1971-06-01

Hypocotyl collapse in dark-grown seedlings of Phaseolus vulgaris cv. Pinto was due to calcium deficiency. There was no evidence of an associated pathogen. The number of seedlings with hypocotyl collapse decreased and the mean hypocotyl length increased when increasing levels of calcium (0-100 micrograms per gram) were supplied in an external nutrient solution to seedlings grown under sterile conditions.When seedlings were supplied with a complete nutrient solution, containing calcium at 100 micrograms per gram, but minus potassium, magnesium, sulfur, nitrogen, or phosphorus, occasional plants developed hypocotyl collapse symptoms; however, the lengths of hypocotyls varied little from those of controls grown in complete nutrient. When the calcium level in the deficient nutrient solutions was raised to 200 micrograms per gram, the number of plants with hypocotyl collapse was reduced markedly.With complete nutrient solution minus calcium, seedlings developed symptoms of calcium deficiency irrespective of seed size, i.e., irrespective of whether or not the seed contained a total calcium content that was low or relatively high.An increase in hypocotyl length in response to an external supply of calcium was obtained with five cultivars of Phaseolus vulgaris L. and with one of Soja max Piper. A similar response to calcium was obtained for epicotyl growth of a cultivar of Vicia faba L., but not for a cultivar of Pisum sativum L.

Association of serum calcium with serum sex steroid hormones in men in NHANES III.

PubMed

Van Hemelrijck, Mieke; Michaelsson, Karl; Nelson, William G; Kanarek, Norma; Dobs, Adrian; Platz, Elizabeth A; Rohrmann, Sabine

2013-12-01

Bone is a positive regulator of male fertility, which indicates a link between regulation of bone remodeling and reproduction or more specifically a link between calcium and androgens. This possibly suggests how calcium is linked to prostate cancer development through its link with the reproductive system. We studied serum calcium and sex steroid hormones in the Third National Health and Nutrition Examination Survey (NHANES III). Serum calcium and sex steroid hormones were measured for 1262 men in NHANES III. We calculated multivariable-adjusted geometric means of serum concentrations of total and estimated free testosterone and estradiol, androstanediol glucuronide (AAG), and sex hormone binding globulin (SHBG) by categories of calcium (lowest 5% [<1.16 mmol/L], mid 90%, top 5% [≥1.30 mmol/L]). Levels of total and free testosterone, total estradiol or AAG did not differ across categories of serum calcium. Adjusted SHBG concentrations were 36.4 for the bottom 5%, 34.2 for the mid 90% and 38.9 nmol/L for the top 5% of serum calcium (Ptrend = 0.006), free estradiol levels were 0.88, 0.92 and 0.80 pg/ml (Ptrend = 0.048). This link between calcium and sex steroid hormones, in particular the U-shaped pattern with SHBG, may, in part, explain why observational studies have found a link between serum calcium and risk of prostate cancer.

Prolonged Hypocalcemic Effect by Pulmonary Delivery of Calcitonin Loaded Poly(Methyl Vinyl Ether Maleic Acid) Bioadhesive Nanoparticles

PubMed Central

Varshosaz, J.; Minaiyan, M.; Forghanian, M.

2014-01-01

The purpose of the present study was to design a pulmonary controlled release system of salmon calcitonin (sCT). Therefore, poly(methyl vinyl ether maleic acid) [P(MVEMA)] nanoparticles were prepared by ionic cross-linking method using Fe2+ and Zn2+ ions. Physicochemical properties of nanoparticles were studied in vitro. The stability of sCT in the optimized nanoparticles was studied by electrophoretic gel method. Plasma calcium levels until 48 h were determined in rats as pulmonary-free sCT solution or nanoparticles (25 μg·kg−1), iv solution of sCT (5 μg·kg−1), and pulmonary blank nanoparticles. The drug remained stable during fabrication and tests on nanoparticles. The optimized nanoparticles showed proper physicochemical properties. Normalized reduction of plasma calcium levels was at least 2.76 times higher in pulmonary sCT nanoparticles compared to free solution. The duration of hypocalcemic effect of pulmonary sCT nanoparticles was 24 h, while it was just 1 h for the iv solution. There was not any significant difference between normalized blood calcium levels reduction in pulmonary drug solution and iv injection. Pharmacological activity of nanoparticles after pulmonary delivery was 65% of the iv route. Pulmonary delivery of P(MVEMA) nanoparticles of sCT enhanced and prolonged the hypocalcemic effect of the drug significantly. PMID:24701588

Targeting Cellular Calcium Homeostasis to Prevent Cytokine-Mediated Beta Cell Death.

PubMed

Clark, Amy L; Kanekura, Kohsuke; Lavagnino, Zeno; Spears, Larry D; Abreu, Damien; Mahadevan, Jana; Yagi, Takuya; Semenkovich, Clay F; Piston, David W; Urano, Fumihiko

2017-07-17

Pro-inflammatory cytokines are important mediators of islet inflammation, leading to beta cell death in type 1 diabetes. Although alterations in both endoplasmic reticulum (ER) and cytosolic free calcium levels are known to play a role in cytokine-mediated beta cell death, there are currently no treatments targeting cellular calcium homeostasis to combat type 1 diabetes. Here we show that modulation of cellular calcium homeostasis can mitigate cytokine- and ER stress-mediated beta cell death. The calcium modulating compounds, dantrolene and sitagliptin, both prevent cytokine and ER stress-induced activation of the pro-apoptotic calcium-dependent enzyme, calpain, and partly suppress beta cell death in INS1E cells and human primary islets. These agents are also able to restore cytokine-mediated suppression of functional ER calcium release. In addition, sitagliptin preserves function of the ER calcium pump, sarco-endoplasmic reticulum Ca 2+ -ATPase (SERCA), and decreases levels of the pro-apoptotic protein thioredoxin-interacting protein (TXNIP). Supporting the role of TXNIP in cytokine-mediated cell death, knock down of TXNIP in INS1-E cells prevents cytokine-mediated beta cell death. Our findings demonstrate that modulation of dynamic cellular calcium homeostasis and TXNIP suppression present viable pharmacologic targets to prevent cytokine-mediated beta cell loss in diabetes.

Long-term effects of L- and N-type calcium channel blocker on uric acid levels and left atrial volume in hypertensive patients.

PubMed

Masaki, Mitsuru; Mano, Toshiaki; Eguchi, Akiyo; Fujiwara, Shohei; Sugahara, Masataka; Hirotani, Shinichi; Tsujino, Takeshi; Komamura, Kazuo; Koshiba, Masahiro; Masuyama, Tohru

2016-11-01

Left ventricular (LV) diastolic dysfunction is associated with hypertension and hyperuricemia. However, it is not clear whether the L- and N-type calcium channel blocker will improve LV diastolic dysfunction through the reduction of uric acid. The aim of this study was to investigate the effects of anti-hypertensive therapy, the L- and N-type calcium channel blocker, cilnidipine or the L-type calcium channel blocker, amlodipine, on left atrial reverse remodeling and uric acid in hypertensive patients. We studied 62 patients with untreated hypertension, randomly assigned to cilnidipine or amlodipine for 48 weeks. LV diastolic function was assessed with the left atrial volume index (LAVI), mitral early diastolic wave (E), tissue Doppler early diastolic velocity (E') and the ratio (E/E'). Serum uric acid levels were measured before and after treatment. After treatment, systolic and diastolic blood pressures equally dropped in both groups. LAVI, E/E', heart rate and uric acid levels decreased at 48 weeks in the cilnidipine group but not in the amlodipine group. The % change from baseline to 48 weeks in LAVI, E wave, E/E' and uric acid levels were significantly lower in the cilnidipine group than in the amlodipine group. Larger %-drop in uric acid levels were associated with larger %-reduction of LAVI (p < 0.01). L- and N-type calcium channel blocker but not L-type calcium channel blocker may improve LV diastolic function in hypertensive patients, at least partially through the decrease in uric acid levels.

Calcium Regulates FGF-23 Expression in Bone

PubMed Central

David, Valentin; Dai, Bing; Martin, Aline; Huang, Jinsong; Han, Xiaobin

2013-01-01

Calcium has recently been shown to regulate fibroblast growth factor 23 (FGF-23), a bone-derived phosphate and vitamin D-regulating hormone. To better understand the regulation of FGF-23 by calcium, phosphorus, 1,25 dihydroxyvitamin D3 [1,25(OH)2D], and PTH, we examined FGF-23 expression under basal conditions and in response to PTH, doxercalciferol, or high-calcium diet treatment in Gcm2−/− and Cyp27b1−/− mutant mice. Gcm2−/− mice exhibited low serum PTH and 1,25(OH)2D concentrations, hypocalcemia, and hyperphosphatemia, whereas Cyp27b1−/− mice had high PTH, undetectable 1,25(OH)2D, hypocalcemia, and hypophosphatemia. Serum FGF-23 levels were decreased in both mutant models. Doxercalciferol administration increased serum FGF-23 levels in both mutant models. PTH administration to Gcm2−/− mice also increased serum FGF-23 levels, in association with an increase in both 1,25(OH)2D and calcium concentrations. Multiple regression analysis of pooled data indicated that changes in FGF-23 were positively correlated with serum calcium and 1,25(OH)2D but not related to changes in serum phosphate concentrations. A high-calcium diet also increased serum FGF-23 concentrations in Cyp27b1−/− mice in the absence of 1,25(OH)2D and in Gcm2−/− mice with low PTH. The addition of calcium to the culture media also stimulated FGF-23 message expression in MC3T3-E1 osteoblasts. In addition, FGF-23 promoter activity in cultured osteoblasts was inhibited by the L-calcium-channel inhibitor nifedipine and stimulated by calcium ionophores. The effects of chronic low calcium to prevent 1,25(OH)2D and PTH stimulation of FGF-23 in these mutant mouse models suggest that suppression of FGF-23 plays an important physiological adaptive response to hypocalcemia. PMID:24140714

Calcium regulates FGF-23 expression in bone.

PubMed

David, Valentin; Dai, Bing; Martin, Aline; Huang, Jinsong; Han, Xiaobin; Quarles, L Darryl

2013-12-01

Calcium has recently been shown to regulate fibroblast growth factor 23 (FGF-23), a bone-derived phosphate and vitamin D-regulating hormone. To better understand the regulation of FGF-23 by calcium, phosphorus, 1,25 dihydroxyvitamin D3 [1,25(OH)2D], and PTH, we examined FGF-23 expression under basal conditions and in response to PTH, doxercalciferol, or high-calcium diet treatment in Gcm2(-/-) and Cyp27b1(-/-) mutant mice. Gcm2(-/-) mice exhibited low serum PTH and 1,25(OH)2D concentrations, hypocalcemia, and hyperphosphatemia, whereas Cyp27b1(-/-) mice had high PTH, undetectable 1,25(OH)2D, hypocalcemia, and hypophosphatemia. Serum FGF-23 levels were decreased in both mutant models. Doxercalciferol administration increased serum FGF-23 levels in both mutant models. PTH administration to Gcm2(-/-) mice also increased serum FGF-23 levels, in association with an increase in both 1,25(OH)2D and calcium concentrations. Multiple regression analysis of pooled data indicated that changes in FGF-23 were positively correlated with serum calcium and 1,25(OH)2D but not related to changes in serum phosphate concentrations. A high-calcium diet also increased serum FGF-23 concentrations in Cyp27b1(-/-) mice in the absence of 1,25(OH)2D and in Gcm2(-/-) mice with low PTH. The addition of calcium to the culture media also stimulated FGF-23 message expression in MC3T3-E1 osteoblasts. In addition, FGF-23 promoter activity in cultured osteoblasts was inhibited by the L-calcium-channel inhibitor nifedipine and stimulated by calcium ionophores. The effects of chronic low calcium to prevent 1,25(OH)2D and PTH stimulation of FGF-23 in these mutant mouse models suggest that suppression of FGF-23 plays an important physiological adaptive response to hypocalcemia.

Predictive Mechanical Characterization of Macro-Molecular Material Chemistry Structures of Cement Paste at Nano Scale - Two-phase Macro-Molecular Structures of Calcium Silicate Hydrate, Tri-Calcium Silicate, Di-Calcium Silicate and Calcium Hydroxide

NASA Astrophysics Data System (ADS)

Padilla Espinosa, Ingrid Marcela

Concrete is a hierarchical composite material with a random structure over a wide range of length scales. At submicron length scale the main component of concrete is cement paste, formed by the reaction of Portland cement clinkers and water. Cement paste acts as a binding matrix for the other components and is responsible for the strength of concrete. Cement paste microstructure contains voids, hydrated and unhydrated cement phases. The main crystalline phases of unhydrated cement are tri-calcium silicate (C3S) and di-calcium silicate (C2S), and of hydrated cement are calcium silicate hydrate (CSH) and calcium hydroxide (CH). Although efforts have been made to comprehend the chemical and physical nature of cement paste, studies at molecular level have primarily been focused on individual components. Present research focuses on the development of a method to model, at molecular level, and analysis of the two-phase combination of hydrated and unhydrated phases of cement paste as macromolecular systems. Computational molecular modeling could help in understanding the influence of the phase interactions on the material properties, and mechanical performance of cement paste. Present work also strives to create a framework for molecular level models suitable for potential better comparisons with low length scale experimental methods, in which the sizes of the samples involve the mixture of different hydrated and unhydrated crystalline phases of cement paste. Two approaches based on two-phase cement paste macromolecular structures, one involving admixed molecular phases, and the second involving cluster of two molecular phases are investigated. The mechanical properties of two-phase macromolecular systems of cement paste consisting of key hydrated phase CSH and unhydrated phases C3S or C2S, as well as CSH with the second hydrated phase CH were calculated. It was found that these cement paste two-phase macromolecular systems predicted an isotropic material behavior. Also, these systems exhibited a high bulk modulus, compared to the elastic modulus. These results are an indication and concur with the high compression strength of cement paste seen at engineering length scale. In addition, the bulk modulus of two-phase systems consisting of hydrated CSH and unhydrated C3S or C2S was found to increase with higher levels of unhydrated components. The interaction energies of two-phase cement paste molecular structures studied in the present work were calculated, showing that a higher interaction is attained when the two phases are admixed as small components instead of cluster of phases. Finally, the mechanical behavior under shear deformation was predicted by using a quasi-static deformation method and analyzed for a representative two-phase (CSH and C2S) macromolecular structure of cement paste.

Calcium and energy: making the cake and eating it too?

PubMed

Green, Douglas R; Wang, Ruoning

2010-07-23

Mitochondrial calcium ions promote a number of events that sustain ATP levels in the cell. Cardenas et al. (2010) now demonstrate that the inositol 1,4,5-triphosphate receptor at the endoplasmic reticulum constitutively provides calcium for mitochondria. In the absence of this calcium transfer, cells use autophagy to sustain survival. Copyright 2010 Elsevier Inc. All rights reserved.

Hydrogen peroxide homeostasis: activation of plant catalase by calcium/calmodulin

NASA Technical Reports Server (NTRS)

Yang, T.; Poovaiah, B. W.

2002-01-01

Environmental stimuli such as UV, pathogen attack, and gravity can induce rapid changes in hydrogen peroxide (H(2)O(2)) levels, leading to a variety of physiological responses in plants. Catalase, which is involved in the degradation of H(2)O(2) into water and oxygen, is the major H(2)O(2)-scavenging enzyme in all aerobic organisms. A close interaction exists between intracellular H(2)O(2) and cytosolic calcium in response to biotic and abiotic stresses. Studies indicate that an increase in cytosolic calcium boosts the generation of H(2)O(2). Here we report that calmodulin (CaM), a ubiquitous calcium-binding protein, binds to and activates some plant catalases in the presence of calcium, but calcium/CaM does not have any effect on bacterial, fungal, bovine, or human catalase. These results document that calcium/CaM can down-regulate H(2)O(2) levels in plants by stimulating the catalytic activity of plant catalase. Furthermore, these results provide evidence indicating that calcium has dual functions in regulating H(2)O(2) homeostasis, which in turn influences redox signaling in response to environmental signals in plants.

Effects of Serum Albumin, Calcium Levels, Cancer Stage and Performance Status on Weight Loss in Parathyroid Hormone-Related Peptide Positive or Negative Patients with Cancer.

PubMed

Lee, Ji Yeon; Hong, Namki; Kim, Hye Ryun; Lee, Byung Wan; Kang, Eun Seok; Cha, Bong Soo; Lee, Yong Ho

2018-03-01

A recent animal study showed that parathyroid hormone-related peptide (PTHrP) is associated with cancer cachexia by promoting adipose tissue browning, and we previously demonstrated that PTHrP predicts weight loss (WL) in patients with cancer. In this study, we investigated whether prediction of WL by PTHrP is influenced by clinical factors such as serum albumin, corrected calcium levels, cancer stage, and performance status (PS). A cohort of 219 patients with cancer whose PTHrP level was measured was enrolled and followed for body weight (BW) changes. Subjects were divided into two groups by serum albumin (cutoff value, 3.7 g/dL), corrected calcium (cutoff value, 10.5 mg/dL), cancer stage (stage 1 to 3 or 4), or PS (Eastern Cooperative Oncology Group 0 to 1 or 2 to 4), respectively. Clinically significant WL was defined as either percent of BW change (% BW) <-5% or % BW <-2% plus body mass index (BMI) <20 kg/m². After a median follow-up of 327 days, 74 patients (33.8%) experienced clinically significant WL. A positive PTHrP level was associated with a 2-fold increased risk of WL after adjusting for age, baseline BMI, serum albumin, corrected calcium level, cancer stage, and PS. The effect of PTHrP on WL remained significant in patients with low serum albumin, stage 4 cancer, and good PS. Regardless of calcium level, the effect of PTHrP on WL was maintained, although there was an additive effect of higher calcium and PTHrP levels. Early recognition of patients with advanced cancer who are PTHrP positive with hypercalcemia or hypoalbuminemia is needed for their clinical management. Copyright © 2018 Korean Endocrine Society.

Expressed sequence tag analysis of adult human optic nerve for NEIBank: Identification of cell type and tissue markers

PubMed Central

Bernstein, Steven L; Guo, Yan; Peterson, Katherine; Wistow, Graeme

2009-01-01

Background The optic nerve is a pure white matter central nervous system (CNS) tract with an isolated blood supply, and is widely used in physiological studies of white matter response to various insults. We examined the gene expression profile of human optic nerve (ON) and, through the NEIBANK online resource, to provide a resource of sequenced verified cDNA clones. An un-normalized cDNA library was constructed from pooled human ON tissues and was used in expressed sequence tag (EST) analysis. Location of an abundant oligodendrocyte marker was examined by immunofluorescence. Quantitative real time polymerase chain reaction (qRT-PCR) and Western analysis were used to compare levels of expression for key calcium channel protein genes and protein product in primate and rodent ON. Results Our analyses revealed a profile similar in many respects to other white matter related tissues, but significantly different from previously available ON cDNA libraries. The previous libraries were found to include specific markers for other eye tissues, suggesting contamination. Immune/inflammatory markers were abundant in the new ON library. The oligodendrocyte marker QKI was abundant at the EST level. Immunofluorescence revealed that this protein is a useful oligodendrocyte cell-type marker in rodent and primate ONs. L-type calcium channel EST abundance was found to be particularly low. A qRT-PCR-based comparative mammalian species analysis reveals that L-type calcium channel expression levels are significantly lower in primate than in rodent ON, which may help account for the class-specific difference in responsiveness to calcium channel blocking agents. Several known eye disease genes are abundantly expressed in ON. Many genes associated with normal axonal function, mRNAs associated with axonal transport, inflammation and neuroprotection are observed. Conclusion We conclude that the new cDNA library is a faithful representation of human ON and EST data provide an initial overview of gene expression patterns in this tissue. The data provide clues for tissue-specific and species-specific properties of human ON that will help in design of therapeutic models. PMID:19778450

The role of wall calcium in the extension of cell walls of soybean hypocotyls

NASA Technical Reports Server (NTRS)

Virk, S. S.; Cleland, R. E.

1990-01-01

Calcium crosslinks are load-bearing bonds in soybean (Glycine max (L.) Merr.) hypocotyl cell walls, but they are not the same load-bearing bonds that are broken during acid-mediated cell elongation. This conclusion is reached by studying the relationship between wall calcium, pH and the facilitated creep of frozen-thawed soybean hypocotyl sections. Supporting data include the following observations: 1) 2-[(2-bis-[carboxymethyl]amino-5-methylphenoxy)methyl]-6-methoxy-8-bis[car boxymethyl]aminoquinoline (Quin 2) and ethylene glycol-bis(2-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) caused only limited facilitated creep as compared with acid, despite removal of comparable or larger amounts of wall calcium; 2) the pH-response curves for calcium removal and acid-facilitated creep were different; 3) reversible acid-extension occurred even after removal of almost all wall calcium with Quin 2; and 4) growth of abraded sections did not involve a proportional loss of wall calcium. Removal of wall calcium, however, increased the capacity of the walls to undergo acid-facilitated creep. These data indicate that breakage of calcium crosslinks is not a major mechanism of cell-wall loosening in soybean hypocotyl tissues.

The elementome of calcium-based urinary stones and its role in urolithiasis

PubMed Central

Ramaswamy, Krishna; Killilea, David W.; Kapahi, Pankaj; Kahn, Arnold J.; Chi, Thomas; Stoller, Marshall L.

2016-01-01

Urolithiasis affects around 10% of the US population with an increasing rate of prevalence, recurrence and penetrance. The causes for the formation of most urinary calculi remain poorly understood, but obtaining the chemical composition of these stones might help identify key aspects of this process and new targets for treatment. The majority of urinary stones are composed of calcium that is complexed in a crystalline matrix with organic and inorganic components. Surprisingly, mitigation of urolithiasis risk by altering calcium homeostasis has not been very effective. Thus, studies to identify other therapeutic stone-specific targets, using proteomics, metabolomics and microscopy techniques, have been conducted, revealing a high level of complexity. The data suggest that numerous metals other than calcium and many nonmetals are present within calculi at measurable levels and several have distinct distribution patterns. Manipulation of the levels of some of these elemental components of calcium-based stones has resulted in clinically beneficial changes in stone chemistry and rate of stone formation. The elementome—the full spectrum of elemental content—of calcium-based urinary calculi is emerging as a new concept in stone research that continues to provide important insights for improved understanding and prevention of urinary stone disease. PMID:26334088

Prophylactic intravenous calcium therapy for exchange blood transfusion in the newborn.

PubMed

Ogunlesi, Tinuade A; Lesi, Foluso Ea; Oduwole, Olabisi

2017-10-12

Exchange blood transfusion (EBT) is a form of whole blood transfusion in which the total blood volume is replaced within a few hours. In perinatal and neonatal medicine, EBT is most often used in the management of severe anaemia or severe hyperbilirubinaemia in the first week of life. Hypocalcaemia, one of the common morbidities associated with EBT, is thought to arise from the chelating effects of the citrate commonly used as an anticoagulant in the donor's blood. This disorder manifests with muscular and nervous irritability and cardiac arrhythmias. To determine whether the use of prophylactic calcium reduces the risk of hypocalcaemia-related morbidities and death among newborn infants receiving EBT. We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 5), MEDLINE via PubMed (1966 to 29 June 2016), Embase (1980 to 29 June 2016), and CINAHL (1982 to 29 June 2016). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. All randomised and quasi-randomised trials of prophylactic intravenous calcium in EBT for newborns. Two review authors independently assessed and extracted data on methods, participants, interventions, and outcomes (mean total and ionised serum calcium before and after EBT and the presence of adverse events such as hypoglycaemia, apnoea, cardiac arrest, and death immediately after EBT). We reported results as means difference (MD) with 95% confidence intervals (CI) for continuous outcomes and risk ratio (RR) and risk differences (RD) and 95% CIs for dichotomous outcomes. We assessed quality using the Cochrane 'Risk of bias' assessment tool and the GRADE system. We found only one quasi-randomised trial with 30 participants that met our inclusion criteria. In the small trial, total and ionised serum calcium levels were measured immediately before and immediately after EBT. All the participants were included in the final analysis and all the important outcomes were reported. Primary outcomesThere was one death in each group (RR 1.00, 95% CI 0.07 to 14.55; RD 0.00, 95% CI -0.18 to 0.18; participants = 30; studies = 1). The study did not report the presence of cardiac arrhythmias within one week of EBT and the number of infants with serum calcium levels (total less than 8 mg/dL (2 mmol/L) or ionised less than 4.4 mg/dL (1.1 mmol/L)).Pair-wise comparison of EBT with intravenous 10% calcium gluconate versus EBT without intravenous calcium (change from baseline) showed mean total serum calcium was raised in the intervention group compared to the control group (MD -0.46, 95% CI -0.81 to -0.11; participants = 30; studies = 1). Very low-quality evidence also indicated an increase in the levels of mean ionised serum calcium in the intervention group compared to the control group (MD -0.22, 95% CI -0.33 to -0.11; participants = 30; studies = 1). Secondary outcomesAdverse reactions to intravenous calcium therapy included cardiac arrest in one neonate in the intervention arm (RR 3.00, 95% CI 0.13 to 68.26; RD 0.07, 95% CI -0.10 to 0.23; participants = 30; studies = 1). There was apnoea and hypoglycaemia (RR 1.00, 95% CI 0.07 to 14.55; RD 0.00, 95% CI -0.18 to 0.18; participants = 30; studies = 1) in the two neonates who died. Data were not available for other major secondary outcomes such as the number of infants with reduced serum magnesium, reduced parathormone, increased calcitonin, presence of seizures, carpopedal spasm, jitteriness and prolonged QTc interval on electrocardiography within one week of EBT. Very low-quality data from one quasi-randomised controlled trial suggested that the mean serum total and ionised calcium increased in the study group but decreased in the control group immediately after EBT. However, the mean values of total and ionised calcium in both arms of studies remained within international reference ranges. Unfortunately, data were not available to assess the trend of total and ionised serum calcium to the end of the first week after EBT. Therefore, due to the very low quality of evidence available, it is difficult to support or reject the continual use of prophylactic intravenous calcium in newborn infants receiving EBT. Researchers are encouraged to conduct more robustly designed trials with larger numbers of participants, and particularly, addressing the pattern of differences based on gestational age of participants, type of anticoagulant used, and the volume of blood used.

Is bone equally responsive to calcium and vitamin D intake from food vs. supplements? Use of 41calcium tracer kinetic model

DOE PAGES

Rogers, Tara S.; Garrod, Marjorie G.; Peerson, Janet M.; ...

2016-05-09

Few interventions directly compare equivalent calcium and vitamin D from dairy vs. supplements on the same bone outcomes. Here, the radioisotope calcium-41 ( 41Ca) holds promise as a tracer method to directly measure changes in bone resorption with differing dietary interventions.

Is bone equally responsive to calcium and vitamin D intake from food vs. supplements? Use of 41calcium tracer kinetic model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Tara S.; Garrod, Marjorie G.; Peerson, Janet M.

Few interventions directly compare equivalent calcium and vitamin D from dairy vs. supplements on the same bone outcomes. Here, the radioisotope calcium-41 ( 41Ca) holds promise as a tracer method to directly measure changes in bone resorption with differing dietary interventions.

Fractional absorption of active absorbable algal calcium (AAACa) and calcium carbonate measured by a dual stable-isotope method

USDA-ARS?s Scientific Manuscript database

With the use of stable isotopes, this study aimed to compare the bioavailability of active absorbable algal calcium (AAACa), obtained from oyster shell powder heated to a high temperature, with an additional heated seaweed component (Heated Algal Ingredient, HAI), with that of calcium carbonate. In ...

Imbalanced Diet Deficient in Calcium and Vitamin D- Induced Juvenile Osteopenia in Rats; the Potential Therapeutic Effect of Egyptian Moghat Roots Water Extract (Glossostemon bruguieri).

PubMed

Ghareeb, Doaa A; El-Rashidy, Fatma H; El-Mallawany, Sherif

2014-01-01

This study aimed to explore and validate a new juvenile osteopenic (JO) rat model then examine the efficacy of moghat (Glossostemon bruguieri) as an alternative reversal therapy for JO. Phytochemical screening analysis showed that moghat contains 5.8% alkaloids, 1.5% flavonoids and 13.2% total phenols. Juvenile osteopenia was induced in 15 days old Sprague- Dawley female rats by feeding them free Ca and vitamin D synthetic diet for 21 days. Osteopenic rats were either treated with moghat (0.8 g dried plant tissue/Kg body weight, orally), or with a reference nutritional supplements of calcium chloride (14 mg Ca/Kg) and vitamin D3 (7 IU/Kg), for extra 21 days. Both untreated and treated groups were compared to a control group that fed a regular pelleted food. Our results showed that osteopenic rats lost normal bone tissue architecture, 30 % of body mass, 54 % of bone mass and finally 93% of bone calcium mass. Furthermore, these rats showed a markedly increase in serum phosphate, PTH, alkaline phosphatase, aspartate transaminase activities and creatinine level as compared to the control group. Moghat administration was successfully reversed osteopenia by normalizing body and bone masses to the reference ranges, increased the bone calcium mass by 17 fold without any detectable side effects on liver and kidney physiological performance. Therefore, moghat could be considered as potent safe -JO- reversal extract.

An evaluation of the levels of 25-hydroxyvitamin D3 and bone turnover markers in professional football players and in physically inactive men.

PubMed

Solarz, K; Kopeć, A; Pietraszewska, J; Majda, F; Słowińska-Lisowska, M; Mędraś, M

2014-01-01

Vitamin D is synthesised in the skin during exposure to sunlight and its fundamental roles are the regulation of calcium and phosphate metabolism and bone mineralisation. The aim of our study was to evaluate serum levels of 25-hydroxyvitamin D3, PTH and bone turnover markers (P1NP, OC, beta-CTx, OC/beta-CTx) and the intake of calcium and vitamin D in Polish Professional Football League (Ekstraklasa) players and in young men with a low level of physical activity. Fifty healthy men aged 19 to 34 years were included in the study. We showed that 25(OH)D3 and P1NP levels and OC/beta-CTx were higher in the group of professional football players than in the group of physically inactive men. The daily vitamin D and calcium intake in the group of professional football players was also higher. We showed a significant relationship between 25(OH)D3 levels and body mass, body cell mass, total body water, fat-free mass, muscle mass, vitamin D and calcium intake. Optimum 25(OH)D3 levels were observed in a mere 16.7% of the football players and vitamin D deficiency was observed in the physically inactive men. The level of physical activity, body composition, calcium and vitamin D intake and the duration of exposure to sunlight may significantly affect serum levels of 25(OH)D3.

Calcium aluminate in alumina

NASA Astrophysics Data System (ADS)

Altay, Arzu

The properties of ceramic materials are determined not only by the composition and structure of the phases present, but also by the distribution of impurities, intergranular films and second phases. The phase distribution and microstructure both depend on the fabrication techniques, the raw materials used, the phase-equilibrium relations, grain growth and sintering processes. In this dissertation research, various approaches have been employed to understand fundamental phenomena such as grain growth, impurity segregation, second-phase formation and crystallization. The materials system chosen was alumina intentionally doped with calcium. Atomic-scale structural analyses of grain boundaries in alumina were carried on the processed samples. It was found that above certain calcium concentrations, CA6 precipitated as a second phase at all sintering temperatures. The results also showed that abnormal grain growth can occur after precipitation and it is not only related to the calcium level, but it is also temperature dependent. In order to understand the formation mechanism of CA6 precipitates in calcium doped alumina samples, several studies have been carried out using either bulk materials or thin films The crystallization of CA2 and CA6 powders has been studied. Chemical processing techniques were used to synthesize the powders. It was observed that CA2 powders crystallized directly, however CA6 powders crystallized through gamma-Al 2O3 solid solution. The results of energy-loss near-edge spectrometry confirmed that gamma-Al2O3 can dissolve calcium. Calcium aluminate/alumina reaction couples have also been investigated. All reaction couples were heat treated following deposition. It was found that gamma-Al2O3 was formed at the interface as a result of the interfacial reaction between the film and the substrate. gamma-Al 2O3 at the interface was stable at much higher temperatures compared to the bulk gamma-Al2O3 formed prior to the CA6 crystallization. In order to complement the studies carried out on the calcium aluminate phases, energy-loss near-edge structure (ELNES) fingerprints of CA2 and CA6 were obtained. It was shown that it is possible to distinguish these phases from each other by comparing the ELNES fingerprints. Theoretical calculations of ELNES were used to assign spectral features to certain symmetry environments that can later be used to understand the structures of unknown materials.

Formate oxidation-driven calcium carbonate precipitation by Methylocystis parvus OBBP.

PubMed

Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Arvaniti, Eleni Charalampous; Hosseinkhani, Baharak; Ramos, Jose Angel; Rahier, Hubert; Boon, Nico

2014-08-01

Microbially induced carbonate precipitation (MICP) applied in the construction industry poses several disadvantages such asammonia release to the air and nitric acid production. An alternative MICP from calcium formate by Methylocystis parvus OBBP is presented here to overcome these disadvantages. To induce calcium carbonate precipitation, M. parvus was incubated at different calcium formate concentrations and starting culture densities. Up to 91.4% ± 1.6% of the initial calcium was precipitated in the methane-amended cultures compared to 35.1% ± 11.9% when methane was not added. Because the bacteria could only utilize methane for growth, higher culture densities and subsequently calcium removals were exhibited in the cultures when methane was added. A higher calcium carbonate precipitate yield was obtained when higher culture densities were used but not necessarily when more calcium formate was added. This was mainly due to salt inhibition of the bacterial activity at a high calcium formate concentration. A maximum 0.67 ± 0.03 g of CaCO3 g of Ca(CHOOH)2(-1) calcium carbonate precipitate yield was obtained when a culture of 10(9) cells ml(-1) and 5 g of calcium formate liter(-)1 were used. Compared to the current strategy employing biogenic urea degradation as the basis for MICP, our approach presents significant improvements in the environmental sustainability of the application in the construction industry.

Formate Oxidation-Driven Calcium Carbonate Precipitation by Methylocystis parvus OBBP

PubMed Central

Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Arvaniti, Eleni Charalampous; Hosseinkhani, Baharak; Ramos, Jose Angel; Rahier, Hubert

2014-01-01

Microbially induced carbonate precipitation (MICP) applied in the construction industry poses several disadvantages such as ammonia release to the air and nitric acid production. An alternative MICP from calcium formate by Methylocystis parvus OBBP is presented here to overcome these disadvantages. To induce calcium carbonate precipitation, M. parvus was incubated at different calcium formate concentrations and starting culture densities. Up to 91.4% ± 1.6% of the initial calcium was precipitated in the methane-amended cultures compared to 35.1% ± 11.9% when methane was not added. Because the bacteria could only utilize methane for growth, higher culture densities and subsequently calcium removals were exhibited in the cultures when methane was added. A higher calcium carbonate precipitate yield was obtained when higher culture densities were used but not necessarily when more calcium formate was added. This was mainly due to salt inhibition of the bacterial activity at a high calcium formate concentration. A maximum 0.67 ± 0.03 g of CaCO3 g of Ca(CHOOH)2−1 calcium carbonate precipitate yield was obtained when a culture of 109 cells ml−1 and 5 g of calcium formate liter−1 were used. Compared to the current strategy employing biogenic urea degradation as the basis for MICP, our approach presents significant improvements in the environmental sustainability of the application in the construction industry. PMID:24837386

[Comparative study of the antimicrobial effect of various cavity liners used in conservative dentistry].

PubMed

Pumarola Suñé, J; Espias Gómez, A; Canalda Sahli, C

1989-01-01

We have compared the microbiological activity of the following cavity liners: Life, Dycal II, Calcipulpe, Pure calcium hydroxide and Cavitec; against five different bacterial strains: Veillonella parvula, Bacteroides fragilis, Peptococcus s.p., Staphylococcus aureus, and Streptococcus beta hemolytic: The results demonstrate the higher antimicrobial activity of the manufactured cavity liners with calcium hydroxide base in comparison with the pure calcium hydroxide.

SUBFIELD AND LAYER-SPECIFIC DEPLETION IN CALBINDIN-D28K, CALRETININ AND PARVALBUMIN IMMUNOREACTIVITY IN THE DENTATE GYRUS OF APP/PS1 TRANSGENIC MICE

PubMed Central

Popovi, Miroljub; Caballero-Bleda, María; Kadish, Inga; van Groen, Thomas

2008-01-01

The depletion of neuronal calcium binding proteins deprives neurons of the capacity to buffer high levels of intracellular Ca2+ and this leaves them vulnerable to pathological processes, such as those present in Alzheimer’s disease (AD). The aim of the present study was to investigate the expression of the calcium binding proteins, calbindin-D28K, calretinin and parvalbumin in the dentate gyrus (DG) of APP/PS1 transgenic mice and their non-Tg littermates, as well as the relation with the deposition of human Aβ. We measured the expression of these three proteins at seven different rostro-caudal levels, and in the molecular, granular and polymorphic layers of the DG. We found that, except in the most caudal part of the DG, there is a substantial loss of calbindin-D28K immunoreactivity in all three layers of the DG in APP/PS1 mice compared to the non-Tg mice. Significant loss of calretinin immunoreactivity is present in most of the polymorphic layer of the DG of APP/PS1 mice compared to the non-Tg mice, as well as in the rostral and intermediate part of the inner molecular layer. Compared to the non-Tg mice parvalbumin immunoreactivity is significantly reduced throughout the whole polymorphic layer as well as in the rostral and intermediate part of the granular layer of DG in APP/PS1 mice. The relatively preservation of calbindin immunoreactivity in the caudal part of molecular and granular layers as well as calretinin immunoreactivity in the caudal part of polymorphic layer of the DG is likely related to the lower Aβ expression in those parts of DG. The present data suggest an involvement of calcium-dependent pathways in the pathogenesis of AD and indicate that there exists a subfield and layer-specific decrease in immunoreactivity which is related to the type of calcium-binding protein in APP/PS1 mice. Moreover, it seems that APP expression affects more the calbindin expression then parvalbumin and calretinin expression in the DG of APP/PS1 transgenic mice. PMID:18583063

Transmural Heterogeneity and Remodeling of Ventricular Excitation-Contraction Coupling in Human Heart Failure

PubMed Central

Lou, Qing; Fedorov, Vadim V.; Glukhov, Alexey V.; Moazami, Nader; Fast, Vladimir G.; Efimov, Igor R.

2011-01-01

Background Excitation-contraction (EC) coupling is altered in the end-stage heart failure (HF). However, spatial heterogeneity of this remodeling has not been established at the tissue level in failing human heart. The objective is to study functional remodeling of EC coupling and calcium handling in failing and nonfailing human hearts. Methods and Results We simultaneously optically mapped action potentials (AP) and calcium transients (CaT) in coronary-perfused left ventricular wedge preparations from nonfailing (n = 6) and failing (n = 5) human hearts. Our major findings are: (1) CaT duration minus AP duration was longer at sub-endocardium in failing compared to nonfailing hearts during bradycardia (40 beats/min). (2) The transmural gradient of CaT duration was significantly smaller in failing hearts compared with nonfailing hearts at fast pacing rates (100 beats/min). (3) CaT in failing hearts had a flattened plateau at the midmyocardium; and exhibited a “two-component” slow rise at sub-endocardium in three failing hearts. (4) CaT relaxation was slower at sub-endocardium than that at sub-epicardium in both groups. Protein expression of sarcoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) was lower at sub-endocardium than that at sub-epicardium in both nonfailing and failing hearts. SERCA2a protein expression at sub-endocardium was lower in hearts with ischemic cardiomyopathy compared with nonischemic cardiomyopathy. Conclusions For the first time, we present direct experimental evidence of transmural heterogeneity of EC coupling and calcium handling in human hearts. End-stage HF is associated with the heterogeneous remodeling of EC coupling and calcium handling. PMID:21502574

HIV associated hypocalcaemia among diarrheic patients in northwest Ethiopia: a cross sectional study

PubMed Central

2014-01-01

Background Hypocalcaemia, defined by serum calcium level less than 8.5 mg/dl, could be caused by human immunodeficiency virus (HIV) and diarrheal diseases. In Ethiopia, while morbidities from diarrheal diseases and HIV are serious health problems, studies assessing the interactions amongst of the three do not exist. Therefore, the present study was undertaken to investigate the level of calcium among diarrheic patients with and without HIV co-infection. Methods Consecutive diarrheic patients attending Gondar University Hospital in Ethiopia were enrolled and screened for HIV, intestinal parasites, Shigella and Salmonella. Concentration of calcium in serum was determined using an inductively coupled plasma mass spectrometer. Results A total of 206 diarrheic patients were included in the study (109 = HIV positive, 97 = HIV negative). Intestinal parasites and Shigella species were detected in 32.2% and 8.5% of the patients, respectively. The serum calcium levels in the patients who were found positive for Shigella species or intestinal parasites was not significantly different by the presence or absence of HIV co-infection. HIV infected diarrheic patients had significantly lower mean serum calcium levels (7.82 ± 1.23 mg/dl) than those negative for HIV (8.38 ± 1.97) (P = 0.015). The age groups 25–35 and greater than 45 years showed significantly lower mean serum calcium levels (7.77 ± 1.55 mg/dl) in comparison to the other age groups (7.84 ± 1.41 mg/dl, P = 0.009). On the other hand, females presented with significantly lower mean serum calcium levels (7.79 ± 1.60 mg/dl, P = 0.044) than males (8.26 ± 1.65 mg/dl). Conclusion There is high prevalence of hypocalcaemia among diarrheic patients in northwest Ethiopia. And HIV stood out to be a major risk factor for development of hypocalcaemia among the diarrheic patients in northwest Ethiopia. Further studies are required to substantiate and characterize the mechanisms and consequences of calcium metabolism disorders among HIV infected individuals in the study area. PMID:24993127

Large-particle calcium hydroxylapatite injection for correction of facial wrinkles and depressions.

PubMed

Alam, Murad; Havey, Jillian; Pace, Natalie; Pongprutthipan, Marisa; Yoo, Simon

2011-07-01

Small-particle calcium hydroxylapatite (Radiesse, Merz, Frankfurt, Germany) is safe and effective for facial wrinkle reduction, and has medium-term persistence for this indication. There is patient demand for similar fillers that may be longer lasting. We sought to assess the safety and persistence of effect in vivo associated with use of large-particle calcium hydroxylapatite (Coaptite, Merz) for facial augmentation and wrinkle reduction. This was a case series of 3 patients injected with large-particle calcium hydroxylapatite. Large-particle calcium hydroxylapatite appears to be effective and well tolerated for correction of facial depressions, including upper mid-cheek atrophy, nasolabial creases, and HIV-associated lipoatrophy. Adverse events included erythema and edema, and transient visibility of the injection sites. Treated patients, all of whom had received small-particle calcium hydroxylapatite correction before, noted improved persistence at 6 and 15 months with the large-particle injections as compared with prior small-particle injections. This is a small case series, and there was no direct control to compare the persistence of small-particle versus large-particle correction. For facial wrinkle correction, large-particle calcium hydroxylapatite has a safety profile comparable with that of small-particle calcium hydroxylapatite. The large-particle variant may have longer persistence that may be useful in selected clinical circumstances. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Low Density Lipoproteins Promote Unstable Calcium Handling Accompanied by Reduced SERCA2 and Connexin-40 Expression in Cardiomyocytes

PubMed Central

Cabello, Nuria; Llach, Anna; Vallmitjana, Alexander; Benítez, Raúl; Badimon, Lina; Cinca, Juan; Llorente-Cortés, Vicenta; Hove-Madsen, Leif

2013-01-01

The damaging effects of high plasma levels of cholesterol in the cardiovascular system are widely known, but little attention has been paid to direct effects on cardiomyocyte function. We therefore aimed at testing the hypothesis that Low Density Lipoprotein (LDL) cholesterol affects calcium dynamics and signal propagation in cultured atrial myocytes. For this purpose, mRNA and protein expression levels were determined by real time PCR and western blot analysis, respectively, and intracellular calcium was visualized in fluo-4 loaded atrial HL-1 myocyte cultures subjected to field stimulation. At low stimulation frequencies all cultures had uniform calcium transients at all tested LDL concentrations. However, 500 µg LDL/mL maximally reduced the calcium transient amplitude by 43% from 0.30±0.04 to 0.17±0.02 (p<0.05). Moreover, LDL-cholesterol dose-dependently increased the fraction of alternating and irregular beat-to-beat responses observed when the stimulation interval was shortened. This effect was linked to a concurrent reduction in SERCA2, RyR2, IP3RI and IP3RII mRNA levels. SERCA2 protein levels were also reduced by 43% at 200 µg LDL/mL (p<0.05) and SR calcium loading was reduced by 38±6% (p<0.001). By contrast, HDL-cholesterol had no significant effect on SERCA expression or SR calcium loading. LDL-cholesterol also slowed the conduction velocity of the calcium signal from 3.2+0.2 mm/s without LDL to 1.7±0.1 mm/s with 500 µg LDL/mL (p<0.05). This coincided with a reduction in Cx40 expression (by 44±3%; p<0.05 for mRNA and by 79±2%; p<0.05 for Cx40 protein at 200 µg/ml LDL) whereas the Cx-43 expression did not significantly change. In conclusion, LDL-cholesterol destabilizes calcium handling in cultured atrial myocytes subjected to rapid pacing by reducing SERCA2 and Cx40 expression and by slowing the conduction velocity of the calcium signal. PMID:23516438

Vitamin D, calcium, and cardiovascular mortality: a perspective from a plenary lecture given at the annual meeting of the American Association of Clinical Endocrinologists.

PubMed

Miller, Paul D

2011-01-01

To examine data showing associations between serum 25-hydroxyvitamin D levels and calcium intake and cardiovascular mortality. The articles reviewed include those published from 1992-2011 derived from search engines (PubMed, Scopus, Medscape) using the following search terms: vitamin D, calcium, cardiovascular events, cardiovascular mortality, all-cause mortality, vascular calcification, chronic kidney disease, renal stones, and hypercalciuria. Because these articles were not weighted (graded) on the level of evidence, this review reflects my own perspective on the data and how they should be applied to clinical management. For skeletal health, vitamin D and calcium are both needed to ensure proper skeletal growth (modeling) and repair (remodeling). Nutritional deficiencies of either vitamin D or calcium may lead to a spectrum of metabolic bone disorders. Excessive consumption of either nutrient has been linked to a variety of medical disorders, such as hypercalcemia or renal stones. There have also been associations between vitamin D or calcium intake and cardiovascular disease. However, neither of these associations have established evidence nor known causality for increasing cardiovascular risk or all-cause mortality in patients with creatinine clearances greater than 60 mL/min. In patients with more severe chronic kidney disease, stronger data link excess calcium (or phosphorus) intake and increase in vascular calcification, but not mortality. The safe upper limit for vitamin D intake is at least 4000 IU daily and probably 10 000 IU daily; for calcium, the safe upper limit is between 2000 and 3000 mg daily. While no solid scientific evidence validates that serum vitamin D levels between 15 and 70 ng/mL are associated with increased cardiovascular disease risk, stronger but inconsistent evidence shows an association between calcium supplementation greater than 500 mg daily and an increase in cardiovascular disease risk. Most professional societies suggest that replacement levels of these nutrients be personalized with the goal of reaching a 25-hydroxyvitamin D concentration between 30 and 50 ng/mL and a calcium intake of 1200 mg daily.

Optimization of Direct Fibroblast Reprogramming to Cardiomyocytes Using Calcium Activity as a Functional Measure of Success

PubMed Central

Addis, Russell C.; Ifkovits, Jamie L.; Pinto, Filipa; Kellam, Lori D.; Esteso, Paul; Rentschler, Stacey; Christoforou, Nicolas; Epstein, Jonathan A.; Gearhart, John D.

2013-01-01

Direct conversion of fibroblasts to induced cardiomyocytes (iCMs) has great potential for regenerative medicine. Recent publications have reported significant progress, but the evaluation of reprogramming has relied upon non-functional measures such as flow cytometry for cardiomyocyte markers or GFP expression driven by a cardiomyocyte-specific promoter. The issue is one of practicality: the most stringent measures - electrophysiology to detect cell excitation and the presence of spontaneously contracting myocytes - are not readily quantifiable in the large numbers of cells screened in reprogramming experiments. However, excitation and contraction are linked by a third functional characteristic of cardiomyocytes: the rhythmic oscillation of intracellular calcium levels. We set out to optimize direct conversion of fibroblasts to iCMs with a quantifiable calcium reporter to rapidly assess functional transdifferentiation. We constructed a reporter system in which the calcium indicator GCaMP is driven by the cardiomyocyte-specific Troponin T promoter. Using calcium activity as our primary outcome measure, we compared several published combinations of transcription factors along with novel combinations in mouse embryonic fibroblasts. The most effective combination consisted of Hand2, Nkx2.5, Gata4, Mef2c, and Tbx5 (HNGMT). This combination is >50-fold more efficient than GMT alone and produces iCMs with cardiomyocyte marker expression, robust calcium oscillation, and spontaneous beating that persists for weeks following inactivation of reprogramming factors. HNGMT is also significantly more effective than previously published factor combinations for the transdifferentiation of adult mouse cardiac fibroblasts to iCMs. Quantification of calcium function is a convenient and effective means for the identification and evaluation of cardiomyocytes generated by direct reprogramming. Using this stringent outcome measure, we conclude that HNGMT produces iCMs more efficiently than previously published methods. PMID:23591016

Fine spatiotemporal activity in contracting myometrium revealed by motion-corrected calcium imaging.

PubMed

Loftus, Fiona C; Shmygol, Anatoly; Richardson, Magnus J E

2014-10-15

Successful childbirth depends on the occurrence of precisely coordinated uterine contractions during labour. Calcium indicator fluorescence imaging is one of the main techniques for investigating the mechanisms governing this physiological process and its pathologies. The effective spatiotemporal resolution of calcium signals is, however, limited by the motion of contracting tissue: structures of interest in the order of microns can move over a hundred times their width during a contraction. The simultaneous changes in local intensity and tissue configuration make motion tracking a non-trivial problem in image analysis and confound many of the standard techniques. This paper presents a method that tracks local motion throughout the tissue and allows for the almost complete removal of motion artefacts. This provides a stabilized calcium signal down to a pixel resolution, which, for the data examined, is in the order of a few microns. As a byproduct of image stabilization, a complete kinematic description of the contraction-relaxation cycle is also obtained. This contains novel information about the mechanical response of the tissue, such as the identification of a characteristic length scale, in the order of 40-50 μm, below which tissue motion is homogeneous. Applied to our data, we illustrate that the method allows for analyses of calcium dynamics in contracting myometrium in unprecedented spatiotemporal detail. Additionally, we use the kinematics of tissue motion to compare calcium signals at the subcellular level and local contractile motion. The computer code used is provided in a freely modifiable form and has potential applicability to in vivo calcium imaging of neural tissue, as well as other smooth muscle tissue. © 2014 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Fine spatiotemporal activity in contracting myometrium revealed by motion-corrected calcium imaging

PubMed Central

Loftus, Fiona C; Shmygol, Anatoly; Richardson, Magnus J E

2014-01-01

Successful childbirth depends on the occurrence of precisely coordinated uterine contractions during labour. Calcium indicator fluorescence imaging is one of the main techniques for investigating the mechanisms governing this physiological process and its pathologies. The effective spatiotemporal resolution of calcium signals is, however, limited by the motion of contracting tissue: structures of interest in the order of microns can move over a hundred times their width during a contraction. The simultaneous changes in local intensity and tissue configuration make motion tracking a non-trivial problem in image analysis and confound many of the standard techniques. This paper presents a method that tracks local motion throughout the tissue and allows for the almost complete removal of motion artefacts. This provides a stabilized calcium signal down to a pixel resolution, which, for the data examined, is in the order of a few microns. As a byproduct of image stabilization, a complete kinematic description of the contraction–relaxation cycle is also obtained. This contains novel information about the mechanical response of the tissue, such as the identification of a characteristic length scale, in the order of 40–50 μm, below which tissue motion is homogeneous. Applied to our data, we illustrate that the method allows for analyses of calcium dynamics in contracting myometrium in unprecedented spatiotemporal detail. Additionally, we use the kinematics of tissue motion to compare calcium signals at the subcellular level and local contractile motion. The computer code used is provided in a freely modifiable form and has potential applicability to in vivo calcium imaging of neural tissue, as well as other smooth muscle tissue. PMID:25085893

Comparison of adaptive statistical iterative and filtered back projection reconstruction techniques in quantifying coronary calcium.

PubMed

Takahashi, Masahiro; Kimura, Fumiko; Umezawa, Tatsuya; Watanabe, Yusuke; Ogawa, Harumi

2016-01-01

Adaptive statistical iterative reconstruction (ASIR) has been used to reduce radiation dose in cardiac computed tomography. However, change of image parameters by ASIR as compared to filtered back projection (FBP) may influence quantification of coronary calcium. To investigate the influence of ASIR on calcium quantification in comparison to FBP. In 352 patients, CT images were reconstructed using FBP alone, FBP combined with ASIR 30%, 50%, 70%, and ASIR 100% based on the same raw data. Image noise, plaque density, Agatston scores and calcium volumes were compared among the techniques. Image noise, Agatston score, and calcium volume decreased significantly with ASIR compared to FBP (each P < 0.001). Use of ASIR reduced Agatston score by 10.5% to 31.0%. In calcified plaques both of patients and a phantom, ASIR decreased maximum CT values and calcified plaque size. In comparison to FBP, adaptive statistical iterative reconstruction (ASIR) may significantly decrease Agatston scores and calcium volumes. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

The relationship between serum and urinary Fetuin-A levels and kidney stone formation among kidney stone patients.

PubMed

Mehrsai, Abdolrasoul; Guitynavard, Fateme; Nikoobakht, Mohammad Reza; Gooran, Shahram; Ahmadi, Ayat

2017-01-01

Mineralization inhibitors are required to prevent the precipitation of minerals and inhibit the formation of kidney stones and other ectopic calcifications. In laboratory studies, Fetuin-A as a glycoprotein has inhibited hydroxyapatite precipitation in calcium and phosphate supersaturated solutions; however, information about patients with kidney stones is limited. The aim of this study was to investigate the association of serum and urinary Fetuin-A levels with calcium oxalate kidney stones. In this case-control study, 30 patients with kidney stones and 30 healthy individuals without any history of urolithiasis who were referred to the urology ward of Sina Hospital of Tehran, Iran, in 2015 were entered into the study. All patients underwent computerized tomography scans. After collecting demographic information, serum and urine levels of Fetuin-A and some other calcification inhibitors and promoters, were measured and compared using T-test, Mann-Whitney and logistic regression between the two study groups. Patients with kidney stones, on average, had lower levels of Serum Fetuin-A (1522.27 ±755.39 vs. 1914.64 ±733.76 μg/ml; P = 0.046) as well as lower levels of Urine Fetuin-A (944.62 ±188.5 vs. 1409.68 ±295.26 μg/ml; P <0.001). Multivariate logistic analysis showed that urinary calcium and serum creatinine are the risk factors and Fetuin-A is a urinary protective factor for kidney stones. PFC Our study showed that patients with kidney stones had lower serum and urinary levels of Fetuin-A. In the logistic regression model, urinary Fetuin-A was reported as a protective factor for kidney stones.

An Exploration of the Calcium-Binding Mode of Egg White Peptide, Asp-His-Thr-Lys-Glu, and In Vitro Calcium Absorption Studies of Peptide-Calcium Complex.

PubMed

Sun, Na; Jin, Ziqi; Li, Dongmei; Yin, Hongjie; Lin, Songyi

2017-11-08

The binding mode between the pentapeptide (DHTKE) from egg white hydrolysates and calcium ions was elucidated upon its structural and thermodynamics characteristics. The present study demonstrated that the DHTKE peptide could spontaneously bind calcium with a 1:1 stoichiometry, and that the calcium-binding site corresponded to the carboxyl oxygen, amino nitrogen, and imidazole nitrogen atoms of the DHTKE peptide. Moreover, the effect of the DHTKE-calcium complex on improving the calcium absorption was investigated in vitro using Caco-2 cells. Results showed that the DHTKE-calcium complex could facilitate the calcium influx into the cytosol and further improve calcium absorption across Caco-2 cell monolayers by more than 7 times when compared to calcium-free control. This study facilitates the understanding about the binding mechanism between peptides and calcium ions as well as suggests a potential application of egg white peptides as nutraceuticals to improve calcium absorption.

Changes in calcium and iron levels in the brains of rats during kainate induced epilepsy

NASA Astrophysics Data System (ADS)

Ren, Min-Qin; Ong, Wei-Yi; Makjanic, Jagoda; Watt, Frank

1999-10-01

Epilepsy is a recurrent disorder of cerebral function characterised by sudden brief attacks of altered consciousness, motor activity or sensory phenomena, and affects approximately 1% of the population. Kainic acid injection induces neuronal degeneration in rats, is associated with glial hypertrophy and proliferation in the CA3-CA4 fields of hippocampal complex, and is a model for temporal lobe epilepsy. In this study we have applied Nuclear Microscopy to the investigation of the elemental changes within the hippocampus and the cortex areas of the rat brain following kainate injection. Analyses of unstained freeze dried tissue sections taken at 1 day and 1, 2, 3 and 4 weeks following injection were carried out using the Nuclear Microscopy facility at the Research Centre for Nuclear Microscopy, National University of Singapore. Quantitative analysis and elemental mapping indicates that there are significant changes in the calcium levels and distributions in the hippocampus as early as 1 day following injection. Preliminary results indicate a rapid increase in cellular calcium. High levels of calcium can activate calcium dependent proteins and phospholipases. Activation of phospholipase A 2 can be harmful to surrounding neurons through free radical damage. In addition to observed increases in calcium, there was evidence of increases in iron levels. This is consistent with measurements in other degenerative brain disorders, and may signal a late surge in free radical production.

Neuropsychiatric manifestations and their outcomes in chronic hypocalcaemia.

PubMed

Maiti, Abhishek; Chatterjee, Sudip

2013-03-01

Hypocalcaemia is an established cause of neurological and psychiatric disease with numerous clinical manifestations. The aim of the study was to determine the outcome of severe neuropsychiatric manifestations of chronic hypocalcaemia after correction of calcium levels. Clinical and laboratory data of 22 patients seen between 1999 and 2009 were retrospectively analysed. Calcium, magnesium, phosphorus, albumin and parathormone values were measured in all cases. All patients except infants under one year of age had computed tomography (CT) scans of the head. Most patients (n = 19; 86%) presented with generalised tonic clonic convulsions while three had seizures with psychiatric manifestations. Movement disorders were present in 4 patients and one had candida meningitis. Nineteen of the 22 patients had primary hypoparathyroidism of which one had associated mucocutaneous candidiasis. One had pseudohypoparathyroidism and two had vitamin D deficiency. All patients improved with calcitriol and calcium treatment. Twelve of the 14 patients with convulsions could be taken off anticonvulsants. Hemiballismus disappeared in one patient and choreiform movements disappeared in one patient and dystonia in two patients. Psychiatric manifestations improved but did not disappear in the three patients who had them. Adult patients with seizures or neuropsychiatric manifestations should have calcium levels checked. Seizure disorders due to chronic hypocalcaemia had excellent prognosis on correction of serum calcium levels. Movement disorders improved markedly. Psychiatric manifestations did not improve substantially on correction of serum calcium levels.

Parathyroid adenoma

MedlinePlus

... the body. They do this by producing parathyroid hormone, or PTH. PTH helps control calcium, phosphorus, and vitamin D levels in the ... from surgery include: Damage to a nerve that controls your voice Damage to the parathyroid ... hormone) and low calcium level When to Contact a ...

Decreased fractional urinary calcium excretion and serum 1,25-dihydroxyvitamin D and IGF-I levels in preeclampsia.

PubMed

Halhali, Ali; Díaz, Lorenza; Avila, Euclides; Ariza, Ana Carolina; Garabédian, Michèle; Larrea, Fernando

2007-03-01

During preeclampsia several alterations of calcium metabolism have been described, the most common of them is hypocalciuria, which pathophysiology is still unclear. In order to assess the contribution of calciotropic hormones to urinary calcium excretion, a cross-sectional study was done including 26 preeclamptic Mexican women (PE group) and 26 normotensive control pregnant women (NT group). Total and fractional urinary calcium excretion were significantly lower (P<0.0001) in the PE group than in the NT group (82+/-7 versus 171+/-7 mg/24h and 0.62+/-0.38 versus 1.38+/-0.71%, respectively), without significant differences in creatinine clearance, urinary sodium excretion and phosphate tubular reabsorption. In addition, serum 1,25-(OH)(2)D and IGF-I levels were significantly (P<0.05) lower in the PE than in NT group (43+/-9 versus 50+/-9 pg/mL and 195+/-67 versus 293+/-105 ng/mL, respectively), without significant differences in serum PTH levels. In the NT group, association analysis showed that total and fractional urinary calcium excretions positively correlated with serum levels of 1,25-(OH)(2)D (P<0.01) and IGF-I (P<0.001). In the PE group, total urinary calcium excretion positively correlated only with serum 1,25-(OH)(2)D (P<0.05). In conclusion, the results obtained in this study confirm that PE is associated with hypocalciuria and suggest that 1,25-(OH)(2)D and/or IGF-I may be involved in the regulation of urinary calcium excretion.

Calcium-regulated in vivo protein phosphorylation in Zea mays L. root tips

NASA Technical Reports Server (NTRS)

Raghothama, K. G.; Reddy, A. S.; Friedmann, M.; Poovaiah, B. W.

1987-01-01

Calcium dependent protein phosphorylation was studied in corn (Zea mays L.) root tips. Prior to in vivo protein phosphorylation experiments, the effect of calcium, ethyleneglycol-bis-(beta-aminoethyl ether)-N-N' -tetraacetic acid (EGTA) and calcium ionophore (A-23187) on phosphorus uptake was studied. Calcium increased phosphorus uptake, whereas EGTA and A-23187 decreased it. Consequently, phosphorus concentration in the media was adjusted so as to attain similar uptake in different treatments. Phosphoproteins were analyzed by two-dimensional gel electrophoresis. Distinct changes in phosphorylation were observed following altered calcium levels. Calcium depletion in root tips with EGTA and A-23187 decreased protein phosphorylation. However, replenishment of calcium following EGTA and ionophore pretreatment enhanced phosphorylation of proteins. Preloading of the root tips with 32P in the presence of EGTA and A-23187 followed by a ten minute calcium treatment, resulted in increased phosphorylation indicating the involvement of calcium, calcium and calmodulin-dependent kinases. Calmodulin antagonist W-7 was effective in inhibiting calcium-promoted phosphorylation. These studies suggest a physiological role for calcium-dependent phosphorylation in calcium-mediated processes in plants.

Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis.

PubMed

Zhao, Jia-Guo; Zeng, Xian-Tie; Wang, Jia; Liu, Lin

2017-12-26

The increased social and economic burdens for osteoporosis-related fractures worldwide make the prevention of such injuries a major public health goal. Previous studies have reached mixed conclusions regarding the association between calcium, vitamin D, or combined calcium and vitamin D supplements and fracture incidence in older adults. To investigate whether calcium, vitamin D, or combined calcium and vitamin D supplements are associated with a lower fracture incidence in community-dwelling older adults. The PubMed, Cochrane library, and EMBASE databases were systematically searched from the inception dates to December 24, 2016, using the keywords calcium, vitamin D, and fracture to identify systematic reviews or meta-analyses. The primary randomized clinical trials included in systematic reviews or meta-analyses were identified, and an additional search for recently published randomized trials was performed from July 16, 2012, to July 16, 2017. Randomized clinical trials comparing calcium, vitamin D, or combined calcium and vitamin D supplements with a placebo or no treatment for fracture incidence in community-dwelling adults older than 50 years. Two independent reviewers performed the data extraction and assessed study quality. A meta-analysis was performed to calculate risk ratios (RRs), absolute risk differences (ARDs), and 95% CIs using random-effects models. Hip fracture was defined as the primary outcome. Secondary outcomes were nonvertebral fracture, vertebral fracture, and total fracture. A total of 33 randomized trials involving 51 145 participants fulfilled the inclusion criteria. There was no significant association of calcium or vitamin D with risk of hip fracture compared with placebo or no treatment (calcium: RR, 1.53 [95% CI, 0.97 to 2.42]; ARD, 0.01 [95% CI, 0.00 to 0.01]; vitamin D: RR, 1.21 [95% CI, 0.99 to 1.47]; ARD, 0.00 [95% CI, -0.00 to 0.01]. There was no significant association of combined calcium and vitamin D with hip fracture compared with placebo or no treatment (RR, 1.09 [95% CI, 0.85 to 1.39]; ARD, 0.00 [95% CI, -0.00 to 0.00]). No significant associations were found between calcium, vitamin D, or combined calcium and vitamin D supplements and the incidence of nonvertebral, vertebral, or total fractures. Subgroup analyses showed that these results were generally consistent regardless of the calcium or vitamin D dose, sex, fracture history, dietary calcium intake, and baseline serum 25-hydroxyvitamin D concentration. In this meta-analysis of randomized clinical trials, the use of supplements that included calcium, vitamin D, or both compared with placebo or no treatment was not associated with a lower risk of fractures among community-dwelling older adults. These findings do not support the routine use of these supplements in community-dwelling older people.

Ghrelin attenuates vascular calcification in diabetic patients with amputation.

PubMed

Xu, Suining; Ye, Fei; Li, Lihua; Yan, Jinchuan; Bao, Zhengyang; Sun, Zhen; Xu, Liangjie; Zhu, Jie; Wang, Zhongqun

2017-07-01

Vascular calcification is established to be a critical factor in diabetes mellitus, which causes cardiovascular and amputation complication of diabetic patients. OPG/RANKL/RANK axis serves as a regulatory role in vascular calcification. Ghrelin, an endogenous ligand of growth hormone secretagogue receptor (GHSR), has been reported to exhibit potent cardiovascular protective effects. However, the role of ghrelin in the regulation of diabetic vascular calcification is still elusive. Here, we reported the role of ghrelin and its relationship with OPG/RANKL/RANK system in patients with diabetic foot amputation. In vivo and in vitro investigations were performed. Sixty type 2 diabetic patients with foot amputation were enrolled in vivo investigation, and they were divided into three groups through Doppler ultrasound: mild stenosis group (n=20), moderate stenosis group (n=20), and severe stenosis/occlusion group (n=20). Morphological analysis results showed diffused calcium depositions in the anterior tibial artery of diabetic amputees. Compared with the mild and moderate stenosis group, the severe stenosis/occlusion group had more spotty calcium depositions in atherosclerotic plaques. Western blot analysis indicated the expressions of osteoprotegerin (OPG) and ghrelin were downregulated, while the expression of receptor activator of nuclear factor kappa B ligand (RANKL) was upregulated with the vascular stenosis aggravation. Pearson correlation analysis revealed a negative correlation between calcium content and ghrelin levels (r=-0.58, P<0.001), as well as the ghrelin levels and sRANKL levels (r=-0.57, P<0.001). Meanwhile, OPG levels were positively correlated with ghrelin levels (r=0.63, P<0.001). From in vitro investigation, we found that the high-glucose (HG), high-lipid (HL), and β-glycerophosphate (β-GP) considerably increased the total calcium content, ALP activity, and expression of osteogenic markers in vascular smooth muscle cells (VSMCs). Ghrelin blunted calcification in a dose-dependent manner. In addition, ghrelin upregulated OPG expression and downregulated RANKL expression in VSMC calcification when anti-OPG antibody and RANKL were performed. Collectively, we therefore conclude serum ghrelin level may be a predictor of diabetic vascular calcification. The possible mechanism may be related with OPG/RANKL signal. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

L-type calcium channels refine the neural population code of sound level.

PubMed

Grimsley, Calum Alex; Green, David Brian; Sivaramakrishnan, Shobhana

2016-12-01

The coding of sound level by ensembles of neurons improves the accuracy with which listeners identify how loud a sound is. In the auditory system, the rate at which neurons fire in response to changes in sound level is shaped by local networks. Voltage-gated conductances alter local output by regulating neuronal firing, but their role in modulating responses to sound level is unclear. We tested the effects of L-type calcium channels (Ca L : Ca V 1.1-1.4) on sound-level coding in the central nucleus of the inferior colliculus (ICC) in the auditory midbrain. We characterized the contribution of Ca L to the total calcium current in brain slices and then examined its effects on rate-level functions (RLFs) in vivo using single-unit recordings in awake mice. Ca L is a high-threshold current and comprises ∼50% of the total calcium current in ICC neurons. In vivo, Ca L activates at sound levels that evoke high firing rates. In RLFs that increase monotonically with sound level, Ca L boosts spike rates at high sound levels and increases the maximum firing rate achieved. In different populations of RLFs that change nonmonotonically with sound level, Ca L either suppresses or enhances firing at sound levels that evoke maximum firing. Ca L multiplies the gain of monotonic RLFs with dynamic range and divides the gain of nonmonotonic RLFs with the width of the RLF. These results suggest that a single broad class of calcium channels activates enhancing and suppressing local circuits to regulate the sensitivity of neuronal populations to sound level. Copyright © 2016 the American Physiological Society.

Hypocalcaemia, alcohol drinking and viroimmune responses in ART recipients.

PubMed

Míguez, María José; Burbano-Levy, Ximena; Carmona, Talita; Quiros, Clery; Thompson, Michelle; Lewis, John E; Asthana, Desharatan; Rodríguez, Allan; Valiathan, Ranjini; Malow, Robert

2012-12-01

Metabolic perturbations associated with HIV and antiretroviral therapies are widespread. Unfortunately, research has predominantly focused in cardiometabolic problems, neglecting other important areas. In fact, the immune-calcium-skeletal interface has been understudied despite its potential relevance in people living with HIV (PLWH). Using a case-control methodology, 200 PLWH receiving medical care were enrolled and stratified according to hazardous vs. non-hazardous alcohol intake (HAU vs. non-HAU) and calcium (Ca) levels by analyzing baseline data. The group was chosen to represent relatively "pure" HAU with minimal drug use and no psychiatric diagnoses. With these narrow parameters in place, we found evidence that HAU significantly increases TNF-α levels compared to Non-HAU (2.8 ± 0.6 vs. 1.9 ± 0.3 pg/ml, p = 0.05) and decreases blood Ca levels (9 ± 0.6 vs. 9.4 ± 0.5, p = 0.03). Our analyses also suggest that chronic inflammation, as indicated by increased TNF-α levels, is associated with hypocalcemia (hypoCa <8.6). Despite the limited prevalence of hypoCa, these findings are clinically significant given that hypoCA PLWH exhibited decreased CD4 (253 ± 224 vs. 417.7 ± 281, p = 0.02), B cells (147 ± 58 vs. 248 ± 151, p = 0.03) and NK cells (146.8 ± 90 vs. 229 ± 148, p = 0.008) and elevated CD8 (902.5 ± 438 vs. 699 ± 510, p = 0.09) compared to those with normal calcium. Furthermore, calcium effects on viral load were also evident with hypoCA exhibiting the highest loads (140,187 ± 111 vs. 35,622 ± 7770 HIV copies, p = 0.01). Multivariate analyses confirmed the significance of hypoCa in predicting viroimmune parameters. This paper provides the first evidence that hypoCa accounts for some of the variation in viroimmune measures in HAART recipients and suggests that hypoCa may be mediating alcohol's deleterious effects. Copyright © 2012 Elsevier Inc. All rights reserved.

The calcium isotope evolution of Lake Lisan, the Dead Sea glacial precursor

NASA Astrophysics Data System (ADS)

Bradbury, H. J.; Turchyn, A. V.; Wong, K.; Torfstein, A.

2016-12-01

Calcium is a stoichiometric component of carbonate minerals whose calcium isotopic composition reflects changes in the calcium isotope composition of the water from which it precipitates as well as the calcium isotope fractionation factor during precipitation. The lacustrine deposits of the last glacial Dead Sea (Lisan Formation) are dominated by carbonate minerals (aragonite) that record the geochemical history of the lake. The sediment sequence comprises alternating laminae of aragonite and clay-rich marls, interspersed with primary gypsum beds and disseminated secondary gypsum crystals. The aragonite precipitated annually during high lake stands associated with wet periods, while the primary gypsum precipitated during low lake conditions (arid periods). We report the calcium isotopic composition (δ44Ca in ‰ relative to bulk silicate earth) of primary aragonite laminae, primary gypsum and secondary gypsum at 1-5kyr resolution throughout the Lisan Formation sampled at the Masada section (70 - 14.5 ka). The δ44Ca of the primary gypsum averages +0.29‰, and displays smaller temporal variations than the aragonite, which averages -0.35‰ but ranges between +0.18‰ and -0.68‰. The aragonite δ44Ca changes temporally in sync with the previously reconstructed lake level suggesting the aragonite δ44Ca reflects changes in the lake calcium balance during lake level changes. The secondary gypsum composition (-0.3‰) corresponds to coeval aragonite samples. For the secondary gypsum to have a similar δ44Ca to the aragonite it is likely that the calcium derived from the aragonite in a near quantitative fashion through recrystallization of the aragonite to gypsum. A numerical box model is used to explore the effect of changing lake water levels on the calcium isotope composition of the aragonite and gypsum over the time interval studied.

Voltage-Gated Calcium Channels

NASA Astrophysics Data System (ADS)

Zamponi, Gerald Werner

Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

The ability of a collagen/calcium phosphate scaffold to act as its own vector for gene delivery and to promote bone formation via transfection with VEGF(165).

PubMed

Keeney, Michael; van den Beucken, Jeroen J J P; van der Kraan, Peter M; Jansen, John A; Pandit, Abhay

2010-04-01

Collagen/calcium phosphate scaffolds have been used for bone reconstruction due to their inherent similarities to the bone extracellular matrix. Calcium phosphate alone has also been used as a non-viral vector for gene delivery. The aim of this study was to determine the capability of a collagen/calcium phosphate scaffold to deliver naked plasmid DNA and mediate transfection in vivo. The second goal of the study was to deliver a plasmid encoding vascular endothelial growth factor(165) (pVEGF(165)) to promote angiogenesis, and hence bone formation, in a mouse intra-femoral model. The delivery of naked plasmid DNA resulted in a 7.6-fold increase in mRNA levels of beta-Galactosidase compared to the delivery of plasmid DNA complexed with a partially degraded PAMAM dendrimer (dPAMAM) in a subcutaneous murine model. When implanted in a muirne intra-femoral model, the delivery of pVEGF(165) resulted in a 2-fold increase in bone volume at the defect site relative to control scaffolds without pVEGF(165). It was concluded that a collagen/calcium phosphate scaffold can mediate transfection without the use of additional transfection vectors and can promote bone formation in a mouse model via the delivery of pVEGF(165). 2009 Elsevier Ltd. All rights reserved.

Expanding the range of free calcium regulation in biological solutions.

PubMed

Dweck, David; Reyes-Alfonso, Avelino; Potter, James D

2005-12-15

Many biological systems use ethylene glycol bis (beta-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) to regulate the free calcium concentration ([Ca(2+)](free)) in the presence of physiological levels of free Mg(2+) ([Mg(2+)](free)). Frequently, it is necessary to work at [Ca(2+)](free) beyond EGTA's buffering capabilities. Therefore, we have developed methods to extend the buffering range by adding nitrilotriacetic acid (NTA) to solutions containing EGTA. This extension results from NTA having a lower K'(dCa) than EGTA. Such equilibria are solved by pCa Calculator, a computer program designed to aid in the study of Ca(2+)-dependent physiological processes while accounting for the effects of pH, temperature, and ionic strength. With multiple chelators and pH buffers from which to choose, pCa Calculator calculates the total concentration of each species required to achieve specified free concentrations of Ca(2+), ATP, and Mg(2+). The program is intuitive, user-friendly, and flexible enough to fix or vary the [Mg-ATP(2-)] and ionic strength. Moreover, it can account for increases in experimental volume from calcium addition. A comparative analysis is reported for testing solutions in the presence and absence of NTA by measuring the calcium binding affinity of fluorescent cardiac troponin C. These findings demonstrate that EGTA, when used in conjunction with NTA, improves and expands the regulation of free calcium in solution.

Effects of calcium-fortified ice cream on markers of bone health.

PubMed

Ferrar, L; van der Hee, R M; Berry, M; Watson, C; Miret, S; Wilkinson, J; Bradburn, M; Eastell, R

2011-10-01

Premenopausal women with low calcium intakes consumed calcium-fortified ice cream daily for 28 days. Bone markers, NTX, CTX and PTH decreased significantly by 7 days, with some evidence of a calcium dose-dependent effect. Bone marker responses were observed within 1 h of consuming ice cream. Body weight remained constant over 28 days. Dietary calcium is important for lifelong bone health. Milk is a good source of bioavailable calcium, but consumption has declined among young adults. The aims were to determine whether calcium-fortified ice cream, a palatable source of calcium, produces significant, sustainable changes in bone turnover markers and parathyroid hormone (PTH) in premenopausal women with calcium intake below recommended UK levels. Eighty women, ages 20-39 years (calcium intake <750 mg/day) were randomised to consume lower saturated fat/sugar ice cream containing 96, 244, 459 or 676 mg calcium daily for 28 days. Urinary NTX/Cr, serum CTX, PINP, 1,25D and PTH were measured (baseline, days 1, 7 and 28). Acute changes in CTX and PTH were measured over 5 h (n = 29 women). There were significant mean decreases by 7 days in NTX/Cr, CTX, PTH and 1,25D and increases in PINP (one sample t tests), with a significant dose-dependent effect on CTX analysis of covariance. Only CTX remained suppressed at 28 days. Serum CTX and PTH decreased within 1 h. Body weight did not change significantly between baseline and 28 days. Daily consumption of calcium-fortified ice cream by premenopausal women may significantly reduce levels of the bone resorption marker serum CTX, without stimulating weight gain. The ice cream could be incorporated into the diet to replace low-calcium snacks and thus help individuals with habitually low calcium intakes to meet recommended intakes. The 244 mg calcium preparation would provide more than a quarter of the UK daily recommended nutrient intake for premenopausal women.

Association of urinary calcium excretion with serum calcium and vitamin D levels.

PubMed

Rathod, Anita; Bonny, Olivier; Guessous, Idris; Suter, Paolo M; Conen, David; Erne, Paul; Binet, Isabelle; Gabutti, Luca; Gallino, Augusto; Muggli, Franco; Hayoz, Daniel; Péchère-Bertschi, Antoinette; Paccaud, Fred; Burnier, Michel; Bochud, Murielle

2015-03-06

Population-based data on urinary calcium excretion are scarce. The association of serum calcium and circulating levels of vitamin D [25(OH)D2 or D3] with urinary calcium excretion in men and women from a population-based study was explored. Multivariable linear regression was used to explore factors associated with square root-transformed 24-hour urinary calcium excretion (milligrams per 24 hours) taken as the dependent variable with a focus on month-specific vitamin D tertiles and serum calcium in the Swiss Survey on Salt Study. In total, 624 men and 669 women were studied with mean ages of 49.2 and 47.0 years, respectively (age range=15-95 years). Mean urinary calcium excretion was higher in men than in women (183.05 versus 144.60 mg/24 h; P<0.001). In adjusted models, the association (95% confidence interval) of square root urinary calcium excretion with protein-corrected serum calcium was 1.78 (95% confidence interval, 1.21 to 2.34) mg/24 h per milligram per deciliter in women and 0.59 (95% confidence interval, -0.11 to 1.29) mg/24 h per milligram per deciliter in men. Men in the third 25(OH)D3 tertile had higher square root urinary calcium excretion than men in the first tertile (0.99; 95% confidence interval, 0.36 to 1.63 mg/24 h per nanogram per milliliter), and the corresponding association was 0.32 (95% confidence interval, -0.22 to 0.85) mg/24 h per nanogram per milliliter in women. These sex differences were more marked under conditions of high urinary sodium or urea excretions. There was a positive association of serum calcium with urinary calcium excretion in women but not men. Vitamin 25(OH)D3 was associated with urinary calcium excretion in men but not women. These results suggest important sex differences in the hormonal and dietary control of urinary calcium excretion. Copyright © 2015 by the American Society of Nephrology.

Tibial bone mineral distribution as influenced by calcium, phosphorus, and vitamin D feeding levels in the growing turkey

NASA Technical Reports Server (NTRS)

Spurrell, F. A.; Brenes, J.; Waibel, P.

1974-01-01

Roentgen signs, subperiosteal, endosteal, and trabecular bone growth are evaluated in turkeys fed phosphorus at the 0.5, 0.56, 0.68, 0.90, and 2.70 percent levels. Calcium levels of 0.30, 0.40, 0.60, 1.2, and 3.60 percent were also tested. Vitamin D levels of 0, 100, 300, 900 and 27,000 I.U. per day were likewise evaluated. Roentgen signs, bone mineral as measured by T-125 gamma ray absorption, and bone mineral growth patterns as shown by radiograph area projection are correlated with calcium, phosphorus, and vitamin D feeding levels. Differences in bone growth at the various feeding levels were observed which were not reflected by differences in other studied parameters.

Whey versus soy protein diets and renal status in rats.

PubMed

Aparicio, Virginia A; Nebot, Elena; Tassi, Mohamed; Camiletti-Moirón, Daniel; Sanchez-Gonzalez, Cristina; Porres, Jesús M; Aranda, Pilar

2014-09-01

Different dietary protein sources can promote different renal statuses. We examined the effects of whey protein (WP) and soy protein (SP) intake on plasma, urinary, and morphological renal parameters in rats. One hundred and twenty Wistar rats were randomly distributed into 2 experimental groups fed with either WP or SP diets over 12 weeks. These diets were based on commercial WP or SP isolates. The urinary calcium content was higher in the WP diet compared to the SP diet group (P<.001) whereas the urinary citrate level was lower (P<.001). The urinary pH was more acidic in the WP diet group compared to the SP diet group (P<.001); however, no differences were observed between the groups for any of the renal morphological parameters analyzed (all, P>.05) or other plasma renal markers such as albumin or urea concentrations. The increase of acid and urinary calcium and the lower urinary citrate level observed in the WP diet group could increase the incidence of nephrolithiasis compared to the SP diet group. Despite the WP showed poorer acid-base profile, no significant morphological renal changes were observed. These results suggest that the use of SP instead of WP appears to promote a more alkaline plasma and urinary profile, with their consequent renal advantages.

Lack of association of oral calcium supplementation with coronary artery calcification in rheumatoid arthritis.

PubMed

Geraldino-Pardilla, Laura; Dhaduvai, Shanthi; Giles, Jon T; Bathon, Joan M

2015-06-01

To investigate the association between oral calcium supplementation and coronary artery calcification among rheumatoid arthritis (RA) patients without known cardiovascular disease (CVD). This study was conducted as a nested, prospective cohort study of RA patients without known CVD. The daily supplemental calcium dose was ascertained from each patients' list of prescription and over-the-counter medications at baseline and at visit 2 (median 20 months postbaseline). The coronary artery calcium (CAC) score, a measure of coronary atherosclerosis, was assessed by cardiac multidetector row computed tomography at baseline and at visit 3 (median 39 months postbaseline). The association between calcium supplementation and CAC was explored. Among the 145 RA patients studied, 42 (28%) were taking ≥1,000 mg/day of supplemental calcium at baseline. A CAC score of >100 units was seen in 44 patients (30%) at baseline and 50 patients (34%) at followup. Baseline CAC scores of >100 units were significantly less frequent in patients receiving the higher dosage (≥1,000 mg/day) of supplemental calcium than in those receiving the lower dosage (<1,000 mg/day) (odds ratio [OR] 0.28, 95% confidence interval [95% CI] 0.11-0.74); this association remained significant after adjustment for relevant confounders (adjusted OR 0.30, 95% CI 0.09-0.93). Similarly, at the third study visit, CAC scores of >100 units were less frequent in the higher supplemental calcium dose group compared to the lower dose group (OR 0.41, 95% CI 0.18-0.95); however, after adjustment for relevant confounders, the statistical significance of this association was lost (adjusted OR 0.39, 95% CI 0.14-1.12). No effect of sex heterogeneity was seen in the association of calcium supplementation with coronary artery calcification, and no change in the CAC score over time was observed. Higher levels of oral calcium supplementation were not associated with an increased risk of coronary atherosclerosis, as measured by the CAC score, in this RA cohort. © 2015, American College of Rheumatology.

Is bone equally responsive to calcium and vitamin D intake from food vs. supplements? Use of (41)calcium tracer kinetic model.

PubMed

Rogers, Tara S; Garrod, Marjorie G; Peerson, Janet M; Hillegonds, Darren J; Buchholz, Bruce A; Demmer, Elieke; Richardson, Christine; Gertz, Erik R; Van Loan, Marta D

2016-12-01

Few interventions directly compare equivalent calcium and vitamin D from dairy vs. supplements on the same bone outcomes. The radioisotope calcium-41 ((41)Ca) holds promise as a tracer method to directly measure changes in bone resorption with differing dietary interventions. Using (41)Ca tracer methodology, determine if 4 servings/day of dairy foods results in greater (41)Ca retention than an equivalent amount of calcium and vitamin D from supplements. Secondary objective was to evaluate the time course for the change in (41)Ca retention. In this crossover trial, postmenopausal women (n = 12) were dosed orally with 100 nCi of (41)Ca and after a 180 day equilibration period received dairy (4 servings/day of milk or yogurt; ~ 1300 mg calcium, 400 IU cholecalciferol (vitamin D3/day)) or supplement treatments (1200 mg calcium carbonate/day and 400 IU vitamin D3/day) in random order. Treatments lasted 6 weeks separated by a 6 week washout (WO). Calcium was extracted from weekly 24 h urine collections; accelerator mass spectrometry (AMS) was used to determine the (41/40)Ca ratio. Primary outcome was change in (41/40)Ca excretion. Secondary outcome was the time course for change in (41)Ca excretion during intervention and WO periods. The (41/40)Ca ratio decreased significantly over time during both treatments; there was no difference between treatments. Both treatments demonstrated a significant retention of (41)Ca within 1-2 weeks (p = 0.0007 and p < 0.001 for dairy and supplements, respectively). WO demonstrated a significant decrease (p = 0.0024) in (41)Ca retention within 1-2 weeks, back to pre-intervention levels. These data demonstrate that urinary (41)Ca retention is increased with an increase in calcium and vitamin D intake regardless of the source of calcium, and the increased retention occurs within 1-2 weeks.

Assessment and clinical course of hypocalcemia in critical illness

PubMed Central

2013-01-01

Introduction Hypocalcemia is common in critically ill patients. However, its clinical course during the early days of admission and the role of calcium supplementation remain uncertain, and the assessment of calcium status is inconsistent. We aimed to establish the course of hypocalcemia during the early days of critical illness in relation to mortality and to assess the impact of calcium supplementation on calcium normalization and mortality. Methods Data were collected on 1,038 admissions to the critical care units of a tertiary care hospital. One gram of calcium gluconate was administered intravenously once daily to patients with adjusted calcium (AdjCa) <2.2 mmol/L. Demographic and outcome data were compared in normocalcemic (ionized calcium, iCa, 1.1-1.3 mmol/L) and mildly and severely hypocalcemic patients (iCa 0.9-1.1 mmol/L and <0.9 mmol/L, respectively). The change in iCa concentrations was monitored during the first four days of admission and comparisons between groups were made using Repeated Measures ANOVA. Comparisons of normalization and outcome were made between hypocalcemic patients who did and did not receive calcium replacement according to the local protocol. The suitability of AdjCa to predict low iCa was determined by analyzing sensitivity, specificity and receiver operating characteristic (ROC) curves. Multivariate logistic regression was performed to determine associations of other electrolyte derangements with hypocalcemia. Results 55.2% of patients were hypocalcemic on admission; 6.2% severely so. Severely hypocalcemic patients required critical care for longer (P = 0.001) compared to normocalcemic or mildly hypocalcemic patients, but there was no difference in mortality between groups (P = 0.48). iCa levels normalized within four days in most, with no difference in normalization between those who died and survived (P = 0.35). Severely hypocalcemic patients who failed to normalize their iCa by day 4 had double the mortality (38% vs. 19%, P = 0.15). Neither iCa normalization nor survival were superior in hypocalcemic patients receiving supplementation on admission. AdjCa <2.2 mmol/L had a sensitivity of 78.2% and specificity of 63.3% for predicting iCa <1.1 mmol/L. Low magnesium, sodium and albumin were independently associated with hypocalcemia on admission. Conclusions Hypocalcemia usually normalizes within the first four days after admission to ICU and failure to normalize in severely hypocalcemic patients may be associated with increased mortality. Calcium replacement appears not to improve normalization or mortality. AdjCa is not a good surrogate of iCa in an ICU setting. PMID:23734769

The Roles of Fibroblast Growth Factor (FGF)-23, α-Klotho and Furin Protease in Calcium and Phosphate Homeostasis : A Mini-Review.

PubMed

Mattoo, Roshan L

2014-01-01

The roles of calcitonin, parathormone and calcitriol in the regulation of plasma calcium and phosphate are well-established. However, in autosomal-dominant hypophosphatemic rickety patients, studies have revealed normal plasma levels of calcium, associated with normal thyroid and parathyroid functions, but decreased levels of phosphate and calcitriol despite adequate reserves of vitamin D. Also, in tumoral calcinosis, persistent hyperphosphatemia with increased levels of 1,25(OH)2D3 have been observed. These studies indicate the involvement of factors other than the ones already known. The first decade of this century/millennium has led to the discovery of the involvement of fibroblast growth factor-23, furin protease and α-klotho in the homeostasis of calcium and phosphate, which is the subject of this mini-review.

A quadruped study on chitosan microspheres containing atorvastatin calcium: preparation, characterization, quantification and in-vivo application.

PubMed

Eroglu, Hakan; Nemutlu, Emirhan; Turkoglu, Omer Faruk; Nacar, Osman; Bodur, Ebru; Sargon, Mustafa Fevzi; Beskonakli, Etem; Oner, Levent

2010-09-01

Atorvastatin is commonly used as a cholesterol lowering agent in patients. Recently, the neuroprotective effects of atorvastatin became the focus of many research studies. In this study, we have formulated chitosan microspheres containing atorvastatin calcium. In-vitro characterization of chitosan microspheres and quantification of atorvastatin calcium from formulations were also evaluated. The neuroprotective efficiency of atorvastatin calcium was investigated by an experimental spinal cord injury model. Atorvastatin calcium microspheres were implanted at the laminectomy area (1 mg/kg) immediately after trauma. Twenty-four hours after injury, motor functions of animals were scored according to modified Tarlov Scale. In spinal cord tissues tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6 and lipid peroxidation levels were quantified and ultrastructural changes have been investigated. The results of all parameters indicate that microspheres containing atorvastatin calcium were capable of improving functional outcome, attenuating the expression of TNF-alpha, IL-1beta and IL-6; lowering lipid peroxidation levels and maintaining the preservation of the cellular uniformity.

Calcium-sensitive MRI contrast agents based on superparamagnetic iron oxide nanoparticles and calmodulin

PubMed Central

Atanasijevic, Tatjana; Shusteff, Maxim; Fam, Peter; Jasanoff, Alan

2006-01-01

We describe a family of calcium indicators for magnetic resonance imaging (MRI), formed by combining a powerful iron oxide nanoparticle-based contrast mechanism with the versatile calcium-sensing protein calmodulin and its targets. Calcium-dependent protein–protein interactions drive particle clustering and produce up to 5-fold changes in T2 relaxivity, an indication of the sensors' potency. A variant based on conjugates of wild-type calmodulin and the peptide M13 reports concentration changes near 1 μM Ca2+, suitable for detection of elevated intracellular calcium levels. The midpoint and cooperativity of the response can be tuned by mutating the protein domains that actuate the sensor. Robust MRI signal changes are achieved even at nanomolar particle concentrations (<1 μM in calmodulin) that are unlikely to buffer calcium levels. When combined with technologies for cellular delivery of nanoparticulate agents, these sensors and their derivatives may be useful for functional molecular imaging of biological signaling networks in live, opaque specimens. PMID:17003117

Calcium-sensitive MRI contrast agents based on superparamagnetic iron oxide nanoparticles and calmodulin.

PubMed

Atanasijevic, Tatjana; Shusteff, Maxim; Fam, Peter; Jasanoff, Alan

2006-10-03

We describe a family of calcium indicators for magnetic resonance imaging (MRI), formed by combining a powerful iron oxide nanoparticle-based contrast mechanism with the versatile calcium-sensing protein calmodulin and its targets. Calcium-dependent protein-protein interactions drive particle clustering and produce up to 5-fold changes in T2 relaxivity, an indication of the sensors' potency. A variant based on conjugates of wild-type calmodulin and the peptide M13 reports concentration changes near 1 microM Ca(2+), suitable for detection of elevated intracellular calcium levels. The midpoint and cooperativity of the response can be tuned by mutating the protein domains that actuate the sensor. Robust MRI signal changes are achieved even at nanomolar particle concentrations (<1 microM in calmodulin) that are unlikely to buffer calcium levels. When combined with technologies for cellular delivery of nanoparticulate agents, these sensors and their derivatives may be useful for functional molecular imaging of biological signaling networks in live, opaque specimens.

[Psychosis Associated With Fahr's Syndrome: A Case Report].

PubMed

Cassiani-Miranda, Carlos Arturo; Herazo-Bustos, Mariana; Cabrera-González, Armando; Cadena-Ramos, Ivan; Barrios-Ayola, Francisco

2015-01-01

Fahr syndrome (SF) is a rare neurological disorder, characterized by abnormal deposition of calcium in brain areas that control movement. The case is presented of a 41-year-old female with a convulsive syndrome, psychotic disorder, neurocognitive disorde,r and intellectual disability associated with bilateral brain calcifications and altered calcium/phosphorus metabolism in the context of hypoparathyroidism. Case report. The calcifications found in the patient could be the cause of psychotic symptoms and cognitive impairment. Diagnostic imaging, laboratory tests, psychiatric and neuropsychological assessments are presented. The clinical presentation of this case is compared with similar ones reported in the literature. Therapeutic approaches and clinical outcomes are described. Fahr's syndrome should be suspected in patients with neuropsychiatric disorders and seizures. Neuroimaging studies, and the determining of phosphorus and calcium metabolism and parathyroid hormone levels are important in this type of patient. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Fatigue in isometric contraction in a single muscle fibre: a compartmental calcium ion flow model.

PubMed

Kothiyal, K P; Ibramsha, M

1986-01-01

Fatigue in muscle is a complex biological phenomenon which has so far eluded a definite explanation. Many biochemical and physiological models have been suggested in the literature to account for the decrement in the ability of muscle to sustain a given level of force for a long time. Some of these models have been critically analysed in this paper and are shown to be not able to explain all the experimental observations. A new compartmental model based on the intracellular calcium ion movement in muscle is proposed to study the mechanical responses of a muscle fibre. Computer simulation is performed to obtain model responses in isometric contraction to an impulse and a train of stimuli of long duration. The simulated curves have been compared with experimentally observed mechanical responses of the semitendinosus muscle fibre of Rana pipiens. The comparison of computed and observed responses indicates that the proposed calcium ion model indeed accounts very well for the muscle fatigue.

Enhanced production of alkaline thermostable keratinolytic protease from calcium alginate immobilized cells of thermoalkalophilic Bacillus halodurans JB 99 exhibiting dehairing activity.

PubMed

Shrinivas, Dengeti; Kumar, Raghwendra; Naik, G R

2012-01-01

The thermoalkalophilic Bacillus halodurans JB 99 cells known for production of novel thermostable alkaline keratinolytic protease were immobilized in calcium alginate matrix. Batch and repeated batch cultivation using calcium alginate immobilized cells were studied for alkaline protease production in submerged fermentation. Immobilized cells with 2.5% alginate and 350 beads/flask of initial cell loading showed enhanced production of alkaline protease by 23.2% (5,275 ± 39.4 U/ml) as compared to free cells (4,280 ± 35.4 U/ml) after 24 h. In the semicontinuous mode of cultivation, immobilized cells under optimized conditions produced an appreciable level of alkaline protease in up to nine cycles and reached a maximal value of 5,975 U/ml after the seventh cycle. The enzyme produced from immobilized cells efficiently degraded chicken feathers in the presence of a reducing agent which can help the poultry industry in the management of keratin-rich waste and obtaining value-added products.

Gel-Free/Label-Free Proteomic Analysis of Endoplasmic Reticulum Proteins in Soybean Root Tips under Flooding and Drought Stresses.

PubMed

Wang, Xin; Komatsu, Setsuko

2016-07-01

Soybean is a widely cultivated crop; however, it is sensitive to flooding and drought stresses. The adverse environmental cues cause the endoplasmic reticulum (ER) stress due to accumulation of unfolded or misfolded proteins. To investigate the mechanisms in response to flooding and drought stresses, ER proteomics was performed in soybean root tips. The enzyme activity of NADH cytochrome c reductase was two-fold higher in the ER than other fractions, indicating that the ER was isolated with high purity. Protein abundance of ribosomal proteins was decreased under both stresses compared to control condition; however, the percentage of increased ribosomes was two-fold higher in flooding compared to drought. The ER proteins related to protein glycosylation and signaling were in response to both stresses. Compared to control condition, calnexin was decreased under both stresses; however, protein disulfide isomerase-like proteins and heat shock proteins were markedly decreased under flooding and drought conditions, respectively. Furthermore, fewer glycoproteins and higher levels of cytosolic calcium were identified under both stresses compared to control condition. These results suggest that reduced accumulation of glycoproteins in response to both stresses might be due to dysfunction of protein folding through calnexin/calreticulin cycle. Additionally, the increased cytosolic calcium levels induced by flooding and drought stresses might disturb the ER environment for proper protein folding in soybean root tips.

Effects of Single Vitamin D₃ Injection (200,000 Units) on Serum Fibroblast Growth Factor 23 and Sclerostin Levels in Subjects with Vitamin D Deficiency.

PubMed

Zhang, Dongdong; Seo, Da Hea; Choi, Han Seok; Park, Hye Sun; Chung, Yoon Sok; Lim, Sung Kil

2017-12-01

Vitamin D deficiency remains common in all age groups and affects skeletal and non-skeletal health. Fibroblast growth factor 23 is a bone-derived hormone that regulates phosphate and 1,25-dihydroxyvitamin D homeostasis as a counter regulatory factor. 1,25-Dihydroxyvitamin D stimulates fibroblast growth factor 23 synthesis in bone, while fibroblast growth factor 23 suppresses 1,25-dihydroxyvitamin D production in the kidney. The aim of this study was to evaluate the effects of vitamin D₃ intramuscular injection therapy on serum fibroblast growth factor 23 concentrations, and several other parameters associated with bone metabolism such as sclerostin, dickkopf-1, and parathyroid hormone. A total of 34 subjects with vitamin D deficiency (defined by serum 25-hydroxyvitamin D levels below 20 ng/mL) were randomly assigned to either the vitamin D injection group (200,000 units) or placebo treatment group. Serum calcium, phosphate, urine calcium/creatinine, serum 25-hydroxyvitamin D, fibroblast growth factor 23, sclerostin, parathyroid hormone, and dickkopf-1 levels were serially measured after treatment. Comparing the vitamin D injection group with the placebo group, no significant changes were observed in serum fibroblast growth factor 23, parathyroid hormone, or dickkopf-1 levels. Serum sclerostin concentrations transiently increased at week 4 in the vitamin D group. However, these elevated levels declined later and there were no statistically significant differences as compared with baseline levels. Serum fibroblast factor 23, sclerostin, parathyroid hormone, and dickkopf-1 levels were not affected significantly by single intramuscular injection of vitamin D₃. Copyright © 2017 Korean Endocrine Society

Calcium Modulation of Plant Plasma Membrane-Bound Atpase Activities

NASA Technical Reports Server (NTRS)

Caldwell, C.

1983-01-01

The kinetic properties of barley enzyme are discussed and compared with those of other plants. Possibilities for calcium transport in the plasma membrane by proton pump and ATPase-dependent calcium pumps are explored. Topics covered include the ph phase of the enzyme; high affinity of barley for calcium; temperature dependence, activation enthalpy, and the types of ATPase catalytic sites. Attention is given to lipids which are both screened and bound by calcium. Studies show that barley has a calmodulin activated ATPase that is found in the presence of magnesium and calcium.

Calcium-phosphate metabolism in patients with multiple sclerosis.

PubMed

Kubicka-Baczyk, K; Labuz-Roszak, B; Pierzchala, K; Adamczyk-Sowa, M; Machowska-Majchrzak, A

2015-06-01

The purpose of this study was to evaluate the concentration of 25-hydroxycholecalciferol and parameters of calcium-phosphate metabolism at different periods of relapsing-remitting multiple sclerosis (RRMS). Forty-five patients, residents of Poland (49°-50°, N), were enrolled in the study, i.e. 15 immediately after the diagnosis of RRMS, 15 at the early stage and 15 at the advanced stage of RRMS. The results were compared to values obtained in 20 age- and sex-matched controls. Lower serum concentrations of 25-hydroxycholecalciferol and ionised calcium were found in patients compared to the control group. In patients with the disease duration of 5-6 years, concentrations of 25-hydroxycholecalciferol and ionised calcium were lower than in patients in the earlier period of RRMS. The inverse and clearer direction of changes was found in parathormone serum concentration in patients compared to the controls. In patients with a longer disease duration, a significantly lower 25-hydroxycholecalciferol concentration was found in female patients compared to male patients. In patients, more frequent 25-hydroxycholecalciferol and unsaturated fatty acids' supplementation was observed compared to the controls. In RRMS patients, calcium-phosphate metabolism is disturbed which increases during disease progression.

Zinc oxide nanoparticles decrease the expression and activity of plasma membrane calcium ATPase, disrupt the intracellular calcium homeostasis in rat retinal ganglion cells.

PubMed

Guo, Dadong; Bi, Hongsheng; Wang, Daoguang; Wu, Qiuxin

2013-08-01

Zinc oxide nanoparticle is one of the most important materials with diverse applications. However, it has been reported that zinc oxide nanoparticles are toxic to organisms, and that oxidative stress is often hypothesized to be an important factor in cytotoxicity mediated by zinc oxide nanoparticles. Nevertheless, the mechanism of toxicity of zinc oxide nanoparticles has not been completely understood. In this study, we investigated the cytotoxic effect of zinc oxide nanoparticles and the possible molecular mechanism involved in calcium homeostasis mediated by plasma membrane calcium ATPase in rat retinal ganglion cells. Real-time cell electronic sensing assay showed that zinc oxide nanoparticles could exert cytotoxic effect on rat retinal ganglion cells in a concentration-dependent manner; flow cytometric analysis indicated that zinc oxide nanoparticles could lead to cell damage by inducing the overproduction of reactive oxygen species. Furthermore, zinc oxide nanoparticles could also apparently decrease the expression level and their activity of plasma membrane calcium ATPase, which finally disrupt the intracellular calcium homeostasis and result in cell death. Taken together, zinc oxide nanoparticles could apparently decrease the plasma membrane calcium ATPase expression, inhibit their activity, cause the elevated intracellular calcium ion level and disrupt the intracellular calcium homeostasis. Further, the disrupted calcium homeostasis will trigger mitochondrial dysfunction, generate excessive reactive oxygen species, and finally initiate cell death. Thus, the disrupted calcium homeostasis is involved in the zinc oxide nanoparticle-induced rat retinal ganglion cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

Analysis of the mechanism by which calcium negatively regulates the tyrosine phosphorylation cascade associated with sperm capacitation.

PubMed

Baker, Mark A; Hetherington, Louise; Ecroyd, Heath; Roman, Shaun D; Aitken, R John

2004-01-15

The capacitation of mammalian spermatozoa involves the activation of a cAMP-mediated signal transduction pathway that drives tyrosine phosphorylation via mechanisms that are unique to this cell type. Controversy surrounds the impact of extracellular calcium on this process, with positive and negative effects being recorded in independent publications. We clearly demonstrate that the presence of calcium in the external medium decreases tyrosine phosphorylation in both human and mouse spermatozoa. Under these conditions, a rise in intracellular pH was recorded, however, this event was not responsible for the observed changes in phosphotyrosine expression. Rather, the impact of calcium on tyrosine phosphorylation in these cells was associated with an unexpected change in the intracellular availability of ATP. Thus, the ATP content of both human and mouse spermatozoa fell significantly when these cells were incubated in the presence of external calcium. Furthermore, the removal of glucose, or addition of 2-deoxyglucose, decreased ATP levels within human spermatozoon populations and induced a corresponding decline in phosphotyrosine expression. In contrast, the mitochondrial inhibitor rotenone had no effect on either ATP levels or tyrosine phosphorylation. Addition of the affinity-labeling probe 8-N3 ATP confirmed our prediction that spermatozoa have many calcium-dependent ATPases. Moreover, addition of the ATPase inhibitor thapsigargin, increased intracellular calcium levels, decreased ATP and suppressed tyrosine phosphorylation. Based on these findings, the present study indicates that extracellular calcium suppresses tyrosine phosphorylation by decreasing the availability of intracellular ATP, and not by activating tyrosine phosphatases or inhibiting tyrosine kinases as has been previously suggested.

Pharmacological and clinical properties of calcimimetics: calcium receptor activators that afford an innovative approach to controlling hyperparathyroidism.

PubMed

Nagano, Nobuo

2006-03-01

Circulating levels of calcium ion (Ca2+) are maintained within a narrow physiological range mainly by the action of parathyroid hormone (PTH) secreted from parathyroid gland (PTG) cells. PTG cells can sense small fluctuations in plasma Ca2+ levels by virtue of a cell surface Ca2+ receptor (CaR) that belongs to the superfamily of G protein-coupled receptors (GPCR). Compounds that activate the CaR and inhibit PTH secretion are termed 'calcimimetics' because they mimic or potentiate the effects of extracellular Ca2+ on PTG cell function. Preclinical studies with NPS R-568, a first generation calcimimetic compound that acts as a positive allosteric modulator of the CaR, have demonstrated that oral administration decreases serum levels of PTH and calcium, with a leftward shift in the set-point for calcium-regulated PTH secretion in normal rats. NPS R-568 also suppresses the elevation of serum PTH levels and PTG hyperplasia and can improve bone mineral density (BMD) and strength in rats with chronic renal insufficiency (CRI). Clinical trials with cinacalcet hydrochloride (cinacalcet), a compound with an improved metabolic profile, have shown that long-term treatment continues to suppress the elevation of serum levels of calcium and PTH in patients with primary hyperparathyroidism (1HPT). Furthermore, clinical trials in patients with uncontrolled secondary hyperparathyroidism (2HPT) have demonstrated that cinacalcet not only lowers serum PTH levels, but also the serum phosphorus and calcium x phosphorus product; these are a hallmark of an increased risk of cardiovascular disease and mortality in dialysis patients with end-stage renal disease. Indeed, cinacalcet has already been approved for marketing in several countries. Calcimimetic compounds like cinacalcet have great potential as an innovative medical approach to manage 1HPT and 2HPT.

The effects of calcium and sodium bicarbonate on severe hyperkalaemia during cardiopulmonary resuscitation: A retrospective cohort study of adult in-hospital cardiac arrest.

PubMed

Wang, Chih-Hung; Huang, Chien-Hua; Chang, Wei-Tien; Tsai, Min-Shan; Yu, Ping-Hsun; Wu, Yen-Wen; Hung, Kuan-Yu; Chen, Wen-Jone

2016-01-01

Calcium and sodium bicarbonate (SB) are frequently used in treating patients with severe hyperkalaemia. We evaluated the efficacy of these medications for the treatment of severe hyperkalaemia during cardiopulmonary resuscitation (CPR). We also hypothesised that the effects of these medications might be associated with serum potassium level during CPR. We conducted a retrospective observational study in a single medical centre. From adult patients who had suffered an in-hospital cardiac arrest from 2006 through 2012, we included those with a serum potassium level>6.5 mEq/L measured during CPR. We used multivariable logistic regression analysis to study the association of calcium/SB with sustained return of spontaneous circulation (ROSC). Among the 109 patients included in our analysis, 40 (36.7%) patients achieved sustained ROSC, and only four (3.7%) patients survived to hospital discharge. The mean serum potassium level was 7.8 mEq/L. The analysis indicated that administration of SB was positively associated with sustained ROSC when serum potassium level was <7.9 mEq/L (odds ratio [OR]: 10.51; 95% confidence interval [CI]: 1.50-112.89; p: 0.03); administration of calcium and SB was also positively associated with sustained ROSC when serum potassium level was <9.4 mEq/L (OR: 51.11; 95% CI: 3.12-1639.16; p: 0.01). The use of calcium and SB might be effective in the treatment of severe hyperkalaemia during cardiac arrest. The efficacy of SB/calcium correlated with serum potassium level. However, because the number of patients included in the analysis was small, this conclusion should be further examined in the future. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Calcium and other ions in blood and skeleton of Nicaraguan fresh-water shark.

PubMed

URIST, M R

1962-09-21

The bull shark, Carcharhinus leucas, employing archaic but effective means of regulating the physical-chemical composition of its body fluids, thrives in tropical fresh-water rivers and lakes. The ionic strength of the serum and the concentrations of total solutes, calcium, urea, and other ions are below the levels found in marine elasmobranchs but higher than the levels in teleosts. The patterns of the calcium deposits of the vertebrae are identical in marine and fresh-water subspecies.

The impact of mitochondrial endosymbiosis on the evolution of calcium signaling.

PubMed

Blackstone, Neil W

2015-03-01

At high concentrations, calcium has detrimental effects on biological systems. Life likely arose in a low calcium environment, and the first cells evolved mechanisms to maintain this environment internally. Bursts of calcium influx followed by efflux or sequestration thus developed in a functional context. For example, in proto-cells with exterior energy-converting membranes, such bursts could be used to depolarize the membrane. In this way, proto-cells could maintain maximal phosphorylation (metabolic state 3) and moderate levels of reactive oxygen species (ROS), while avoiding the resting state (metabolic state 4) and high levels of ROS. This trait is likely a shared primitive characteristic of prokaryotes. When eukaryotes evolved, the α-proteobacteria that gave rise to proto-mitochondria inhabited a novel environment, the interior of the proto-eukaryote that had a low calcium concentration. In this environment, metabolic homeostasis was difficult to maintain, and there were inherent risks from ROS, yet depolarizing the proto-mitochondrial membrane by calcium influx was challenging. To maintain metabolic state 3, proto-mitochondria were required to congregate near calcium influx points in the proto-eukaryotic membrane. This behavior, resulting in embryonic forms of calcium signaling, may have occurred immediately after the initiation of the endosymbiosis. Along with ROS, calcium may have served as one of the key forms of crosstalk among the community of prokaryotes that led to the eukaryotic cell. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bone mineral status and metabolism in patients with Williams-Beuren syndrome.

PubMed

Stagi, Stefano; Manoni, Cristina; Scalini, Perla; Chiarelli, Francesco; Verrotti, Alberto; Cecchi, Cecilia; Lapi, Elisabetta; Giglio, Sabrina; Romano, Silvia; de Martino, Maurizio

2016-07-01

To evaluate bone mineral status and metabolism in a cohort of patients with Williams-Beuren syndrome (WBS). Thirty-one children (15 females, 16 males; mean age 9.6±2.74 years) and 10 young adults (6 females, 4 males; mean age 21.4±5.11 years) with WBS were cross-sectionally evaluated and compared with two age-, sex-, and body-size-matched paediatric (155 subjects, 75 females and 80 males; mean age 9.7±2.93 years) and adult (50 subjects, 30 females and 20 males; mean age 22.3±5.42 years) healthy controls. We evaluated ionised and total calcium, phosphate, parathyroid hormone (PTH), 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase levels, and urinary deoxypyridinoline concentrations. We also calculated the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT) z-scores. WBS patients showed a significantly reduced AD-SoS z-score (p <0.001) and BTT z-score (p <0.001) compared with the controls. This finding persisted when we divided the sample into paediatric and adult patients. WBS patients also had significantly higher ionised (p <0.001) and total calcium (p <0.001) levels as well as higher PTH levels (p <0.001) compared with the controls. Furthermore, WBS children and adolescents had significantly lower serum osteocalcin levels (p <0.001) and urinary deoxypyridinoline concentrations (p <0.001) than controls. WBS subjects exhibit a significant reduction in bone mineral status and impaired bone metabolism. These findings point to the need for close monitoring of WBS patients.

Hypercalcemia and hypophosphatemia among preterm infants receiving aggressive parenteral nutrition.

PubMed

Brener Dik, Pablo H; Galletti, María F; Bacigalupo, Leticia T; Fernández Jonusas, Silvia; L Mariani, Gonzalo

2018-06-01

Aggressive parenteral nutrition is the standard of care among very-low-birth weight preterm infants. However, in recent studies, its impact on short-term outcomes, has been evaluated. The objective was to compare the prevalence of hypercalcemia and hypophosphatemia among preterm infants receiving aggressive or standard parenteral nutrition. Observational, retrospective study comparing a group of preterm infants weighing less than 1250 grams who received aggressive parenteral nutrition with a historical control group. The prevalence of hypercalcemia was estimated and its association with aggressive parenteral nutrition was searched adjusting by confounders. The mean phosphate level was estimated for the control group by linear regression and was compared to the value in the other group. Forty patients per group were included. The prevalence of hypercalcemia was higher in the group who received aggressive parenteral nutrition (87.5% versus 35%, p= 0.001). Aggressive parenteral nutrition was associated with hypercalcemia when adjusting by birth weight, intrauterine growth restriction, amino acid, and calorie intake (adjusted odds ratio: 21.8, 95% confidence interval [CI]: 3.7-128). The mean calcium level was different between both groups (p= 0.002). Infants who received aggressive parenteral nutrition had more sepsis without reaching statistical significance and the mean phosphate level was lower than that estimated for the control group (p= 0.04). The prevalence of hypophosphatemia in this group was 90% (95% CI: 76-97%). Our data show an association between hypercalcemia/hypophosphatemia and aggressive parenteral nutrition. It is recommended to frequently monitor calcium and phosphate levels since they might be associated with adverse clinical outcomes. Sociedad Argentina de Pediatría.

Evidence of Multi-Component Ion Exchange in Dolomite Formation during Low Salinity Waterflooding

NASA Astrophysics Data System (ADS)

Srisuriyachai, Falan; Meekangwal, Suthida

2017-12-01

Low salinity waterflooding is a technique performed in many oil reservoirs around the globe. The technique is simply implemented by injecting water with very low ionic activity compared to formation water into an injection well. The injected water will increase reservoir pressure that is compulsory to drive oil moving toward production well. More than just maintaining reservoir pressure as obtained from conventional waterflooding, low salinity water creates shifting of surface condition, resulting in additional amount of liberated oil. Nevertheless, exact oil recovery mechanisms are still discussed. Among these proposed mechanisms, Multi-component Ion Exchange (MIE) together with wettability alteration is believed to be a major mechanism leading to higher oil recovery compared to conventional waterflooding. In this study, detection of calcium and magnesium ions which are Potential Determining Ions (PDI) for carbonate reservoirs are detected during the coreflood experiment. Dolomite rock sample is used to represent carbonate formation and detection of previously mentioned ions is performed by complexometric titration of the effluents. From the study, it is observed that during conventional waterflooding and low salinity waterflooding at low temperature of 30 degrees Celsius, calcium and magnesium ions in the produced water is increased compared to the amount of these ions in the injected water. This incremental of ions can be explained by the dissolution of calcium and magnesium from dolomite which is chemically composed of calcium magnesium carbonate. At this temperature, the portion of calcium ion is always less than magnesium ion even though the amount of calcium ion is higher than magnesium ion in injected water. However, at higher temperatures which are 50 and 70 degrees Celsius, ratio of calcium and magnesium ions in injected and produced water is reversed. Disappearance of magnesium ion in the effluent is more obvious especially at 70 degrees Celsius and by low salinity waterflooding. This can be explained that at lower temperature, calcium ion disappears to form of calcium carboxylate complex with oil and at higher temperature, magnesium ion disappears as magnesium can start to form magnesium carboxylate complex with oil and hence, the amount of both calcium and magnesium ions is decreased compared to lower temperature. In dolomite reservoir, since both calcium ions and magnesium ions are provided from dissolution mechanism, the benefit from multi-component ion exchange will occur at high temperature as both calcium and magnesium ions will be consumed for oil recovery mechanism.

Deficiencies in extrusion of the second polar body due to high calcium concentrations during in vitro fertilization in inbred C3H/He mice.

PubMed

Ohta, Yuki; Nagao, Yoshikazu; Minami, Naojiro; Tsukamoto, Satoshi; Kito, Seiji

2016-08-01

Successful in vitro fertilization (IVF) of all inbred strains of laboratory mice has not yet been accomplished. We have previously shown that a high calcium concentration improved IVF in various inbred mice. However, we also found that in cumulus-free ova of C3H/He mice such IVF conditions significantly increased the deficiency of extrusion of the second polar body (PBII) in a dose-dependent manner (2% at 1.71 mM and 29% at 6.84 mM, P < 0.05) and that PBII extrusion was affected by high calcium levels at 2-3 h post-insemination. While developmental competence of ova without PBII extrusion to blastocysts after 96 h culture was not affected, a significant reduction in the nuclear number of the inner cell mass was observed in blastocyst fertilized under high calcium condition. We also examined how high calcium concentration during IVF affects PBII extrusion in C3H/He mice. Cumulus cells cultured under high calcium conditions showed a significantly alleviated deficient PBII extrusion. This phenomenon is likely to be specific to C3H/He ova because deficient PBII extrusion in reciprocal fertilization between C3H and BDF1 gametes was observed only in C3H/He ova. Sperm factor(s) was still involved in deficient PBII extrusion due to high calcium concentrations, as this phenomenon was not observed in ova activated by ethanol. The cytoskeletal organization of ova without PBII extrusion showed disturbed spindle rotation, incomplete formation of contractile ring and disturbed localization of actin, suggesting that high calcium levels affect the anchoring machinery of the meiotic spindle. These results indicate that in C3H/He mice high calcium levels induce abnormal fertilization, i.e. deficient PBII extrusion by affecting the cytoskeletal organization, resulting in disturbed cytokinesis during the second meiotic division. Thus, use of high calcium media for IVF should be avoided for this strain.

Development of a Radiolabeled Amlodipine Analog for L-type Calcium Channel Imaging.

PubMed

Firouzyar, Tahereh; Jalilian, Amir Reza; Aboudzadeh, Mohammad Reza; Sadeghpour, Hossein; Pooladi, Mehrban; Shafiee-Ardestani, Mahdi; Khalaj, Ali

2017-01-01

The non-invasive imaging and quantification of L-type calcium channels (also known as dihydropyridine channels) in living tissues is of great interest in diagnosis of congestive heart failure, myocardial hypertrophy, irritable bowel syndrome etc. Technetium-99m labeled amlodipine conjugate ([99mTc]-DTPA-AMLO) was prepared starting freshly eluted (<1 h) 99mTechnetium pertechnetate (86.5 MBq) and conjugated DTPAAMLO at pH 5 in 30 min at room temperature in high radiochemical purity (>99%, RTLC; specific activity: 55-60 GBq/mmol). The calcium channel blockade activity (CCBA) and apoptosis/necrosis assay of DTPA-amlodipine conjugate evaluations were performed for the conjugate. Log P, stability, bio-distribution and imaging studies were performed for the tracer followed by biodistribution studies as well as imaging. The conjugate demonstrated low toxicity on MCF-7 cells and CCBA (at µm level) compared to the amlodipine. The tracer was stable up to 4 h in final production and presence of human serum and log P (-0.49) was consistent with a water soluble complex. The tracer was excreted through kidneys and liver as expected for dihydropyridines; excluding excretory organs, calcium channel rich smooth muscle cells; including colon, intestine and lungs which demonstrated significant uptake. SPECT images supported the bio-distribution data up to 4 h. significant uptake of [99mTc]-DTPA-AMLO was obtained in calcium channel rich organs. The complex can be a candidate for further SPECT imaging for L-type calcium channels. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Negative interferences by calcium dobesilate in the detection of five serum analytes involving Trinder reaction-based assays

PubMed Central

Wu, Jie; Zhao, Fang; Xia, Liangyu; Cheng, Xinqi; Liu, Qian; Liu, Li; Xu, Ermu; Qiu, Ling

2018-01-01

Previously, we reported the strong negative interference of calcium dobesilate, a vasoprotective agent, in creatinine assays involving the Trinder reaction. It is hypothesized that a similar effect occurs in the detection of uric acid (UA), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). The interferences of calcium dobesilate during the detection of the five serum analytes were investigated on automated systems/analysers, and the effects were compared among eight different assay systems for each analyte. A calcium dobesilate standard was added into two sets of the blank serum pools of each analyte at final concentrations of 0, 2, 4, 8, 16, 32, and 64 μg/mL. The percentage deviation of each analyte value was calculated between each drug concentration and the drug-free samples. The clinically acceptable error levels for UA, TC, TG, HDL-C, and LDL-C were defined as ±4.87%, ±4.1%, ±9.57%, ±5.61%, and ±5.46%, respectively. The observed interference was concentration dependent for each analyte. In the presence of 16 μg/mL calcium dobesilate, which was within the therapeutic range, all seven Trinder reaction-based UA assay systems, two TG assay systems, two HDL-C assay systems and one TC assay system exhibited negative drug interferences. Calcium dobesilate negatively interferes with the detection of UA, TG, TC, and HDL-C in assay systems based on the Trinder reaction. The effect was most significant in UA and TG detection. PMID:29432460