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1

Calcium and Cancer Prevention: Strengths and Limits of the Evidence  

Cancer.gov

A fact sheet that summarizes the results of studies on calcium and cancer prevention. It includes information about dietary recommendations for calcium, and the amount of calcium in foods and supplements.

2

Adenovirus E3-6.7K Maintains Calcium Homeostasis and Prevents Apoptosis and Arachidonic Acid Release  

E-print Network

to maintain endoplasmic reticulum-Ca2+ homeostasis and inhibit the induction of apoptosis by thapsigargin. The presence of E3-6.7K also lead to a reduction in the TNF-induced release of arachidonic acid from transfected U937 human histiocytic lymphoma cells...

Moise, Alexander R.; Grant, Jason R.; Vitalis, Timothy Z.; Jefferies, Wilfred A.

2002-02-01

3

Calcium binding to an aquatic fulvic acid  

NASA Astrophysics Data System (ADS)

The degree of binding of calcium to aquatic fulvic acid from the Göta River was estimated from potentiometric titrations. A pH-glass electrode and a calcium-selective electrode were used to monitor the free concentrations of the competing, central ions. The ionic strength and the temperature were maintained constant at 0.1 M and 25°C. The total concentration of fulvic acid was maintained at approximately 1 g 1-1, while the total calcium concentration was varied within the range 0-10-3 M. Two types of titrations were carried out: (1) back titration with hydrochloric acid from basic solution, roughly within the pH range 10.5-2.5; (2) titration with calcium chloride at a constant total hydrogen ion concentration. The model applied for the calcium binding was an extension of our previous model for the acid-base behaviour.

Paxéus, Nicklas; Wedborg, Margareta

4

Calcium prevention and treatment of osteoporosis  

Microsoft Academic Search

Less bone loss occurs when calcium intake is adequate. Calcium therapy can increase bone mineral density by 1.5 to 2%. Most\\u000a studies revealing a reduced fracture rate with antiresorptive agents included concomitant calcium supplementation. Calcium\\u000a absorption occurs predominantly in the upper small bowel under the control of 1,25 hydroxyvitamin D. Adequate vitamin D intake\\u000a should be ensured, especially in winter

Mary Beth O'Connell; Pamela L. Stamm

2004-01-01

5

Role of calcium in colon cancer prevention: experimental and clinical studies.  

PubMed

Many dietary factors have been studied for their potential in the chemoprevention of human colorectal cancer. From an epidemiological standpoint, there have been many studies linking calcium intake to colon cancer risk. Significant reductions in risk have been shown for the consumption of milk, dietary calcium and dairy products in general. Additionally, there have been numerous studies of calcium and cell proliferation in experimental animals. Supplemental calcium in the diet or drinking water has been reported to decrease the colonic epithelial hyperproliferation induced by bile and fatty acids, enteric resection, a nutritional stress diet, and to suppress induction of the tumor-promotion enzyme ornithine decarboxylase. Calcium has also demonstrated an inhibitory effect on experimental colon carcinogenesis. Mechanisms of calcium inhibition are still speculative, but the "calcium soaps" hypothesis, fatty acid destabilization of cellular membranes, modulation of protein kinase C and K-ras mutations are under investigation. Additionally, numerous clinical studies of calcium modulation of human colonic hyperproliferation in high-risk groups as well as chemoprevention trials of calcium supplementation are currently ongoing. Although the question of whether dietary calcium can prevent human colorectal cancer remains to be answered, the data presently available appear promising. PMID:7694103

Pence, B C

1993-11-01

6

Calcium stimulation of gastrin and gastric acid secretion: effect of small doses of calcium carbonate  

Microsoft Academic Search

Oral calcium carbonate (0-5 g, pH 9-4) increased serum gastrin and gastric acid output with slight but insignificant change in serum calcium. A similar rise in serum calcium during an intravenous infusion of calcium gluconate failed to increase serum gastrin and gastric acid output. Both intragastric calcium actions were abolished by acidification of the calcium carbonate solution (pH 1-0). The

J Behar; M Hitchings; R D Smyth

1977-01-01

7

Retinoic acid affects calcium signaling in adult molluscan neurons.  

PubMed

Retinoic acid, the active metabolite of vitamin A, is important for nervous system development, regeneration, as well as cognitive functions of the adult central nervous system. These central nervous system functions are all highly dependent on neuronal activity. Retinoic acid has previously been shown to induce changes in the firing properties and action potential waveforms of adult molluscan neurons in a dose- and isomer-dependent manner. In this study, we aimed to determine the cellular pathways by which retinoic acid might exert such effects, by testing the involvement of pathways previously shown to be affected by retinoic acid. We demonstrated that the ability of all-trans retinoic acid (atRA) to induce electrophysiological changes in cultured molluscan neurons was not prevented by inhibitors of protein synthesis, protein kinase A or phospholipase C. However, we showed that atRA was capable of rapidly reducing intracellular calcium levels in the same dose- and isomer-dependent manner as shown previously for changes in neuronal firing. Moreover, we also demonstrated that the transmembrane ion flux through voltage-gated calcium channels was rapidly modulated by retinoic acid. In particular, the peak current density was reduced and the inactivation rate was increased in the presence of atRA, over a similar time course as the changes in cell firing and reductions in intracellular calcium. These studies provide further evidence for the ability of atRA to induce rapid effects in mature neurons. PMID:25343782

Vesprini, Nicholas D; Dawson, Taylor F; Yuan, Ye; Bruce, Doug; Spencer, Gaynor E

2015-01-01

8

Serine hydrolase inhibitors block necrotic cell death by preventing calcium overload of the mitochondria and permeability transition pore formation.  

PubMed

Perturbation of calcium signaling that occurs during cell injury and disease, promotes cell death. In mouse lung fibroblasts A23187 triggered mitochondrial permeability transition pore (MPTP) formation, lactate dehydrogenase (LDH) release, and necrotic cell death that were blocked by cyclosporin A (CsA) and EGTA. LDH release temporally correlated with arachidonic acid release but did not involve cytosolic phospholipase A2? (cPLA2?) or calcium-independent PLA2. Surprisingly, release of arachidonic acid and LDH from cPLA2?-deficient fibroblasts was inhibited by the cPLA2? inhibitor pyrrophenone, and another serine hydrolase inhibitor KT195, by preventing mitochondrial calcium uptake. Inhibitors of calcium/calmodulin-dependent protein kinase II, a mitochondrial Ca(2+) uniporter (MCU) regulator, also prevented MPTP formation and arachidonic acid release induced by A23187 and H2O2. Pyrrophenone blocked MCU-mediated mitochondrial calcium uptake in permeabilized fibroblasts but not in isolated mitochondria. Unlike pyrrophenone, the diacylglycerol analog 1-oleoyl-2-acetyl-sn-glycerol and CsA blocked cell death and arachidonic acid release not by preventing mitochondrial calcium uptake but by inhibiting MPTP formation. In fibroblasts stimulated with thapsigargin, which induces MPTP formation by a direct effect on mitochondria, LDH and arachidonic acid release were blocked by CsA and 1-oleoyl-2-acetyl-sn-glycerol but not by pyrrophenone or EGTA. Therefore serine hydrolase inhibitors prevent necrotic cell death by blocking mitochondrial calcium uptake but not the enzyme releasing fatty acids that occurs by a novel pathway during MPTP formation. This work reveals the potential for development of small molecule cell-permeable serine hydrolase inhibitors that block MCU-mediated mitochondrial calcium overload, MPTP formation, and necrotic cell death. PMID:24297180

Yun, Bogeon; Lee, HeeJung; Ghosh, Moumita; Cravatt, Benjamin F; Hsu, Ku-Lung; Bonventre, Joseph V; Ewing, Heather; Gelb, Michael H; Leslie, Christina C

2014-01-17

9

Genetic Ablation of Calcium-independent Phospholipase A2? Prevents Obesity and Insulin Resistance during High Fat Feeding by Mitochondrial Uncoupling and Increased Adipocyte Fatty Acid Oxidation*  

PubMed Central

Phospholipases are critical enzyme mediators participating in many aspects of cellular function through modulating the generation of lipid 2nd messengers, membrane physical properties, and cellular bioenergetics. Here, we demonstrate that mice null for calcium-independent phospholipase A2? (iPLA2??/?) are completely resistant to high fat diet-induced weight gain, adipocyte hypertrophy, hyperinsulinemia, and insulin resistance, which occur in iPLA2?+/+ mice after high fat feeding. Notably, iPLA2??/? mice were lean, demonstrated abdominal lipodystrophy, and remained insulin-sensitive despite having a marked impairment in glucose-stimulated insulin secretion after high fat feeding. Respirometry of adipocyte explants from iPLA2??/? mice identified increased rates of oxidation of multiple different substrates in comparison with adipocyte explants from wild-type littermates. Shotgun lipidomics of adipose tissue from wild-type mice demonstrated the anticipated 2-fold increase in triglyceride content after high fat feeding. In sharp contrast, the adipocyte triglyceride content was identical in iPLA2??/? mice fed either a standard diet or a high fat diet. Respirometry of skeletal muscle mitochondria from iPLA2??/? mice demonstrated marked decreases in state 3 respiration using multiple substrates whose metabolism was uncoupled from ATP production. Shotgun lipidomics of skeletal muscle revealed a decreased content of cardiolipin with an altered molecular species composition thereby identifying the mechanism underlying mitochondrial uncoupling in the iPLA2??/? mouse. Collectively, these results identify iPLA2? as an obligatory upstream enzyme that is necessary for efficient electron transport chain coupling and energy production through its participation in the alterations of cellular bioenergetics that promote the development of the metabolic syndrome. PMID:20817734

Mancuso, David J.; Sims, Harold F.; Yang, Kui; Kiebish, Michael A.; Su, Xiong; Jenkins, Christopher M.; Guan, Shaoping; Moon, Sung Ho; Pietka, Terri; Nassir, Fatiha; Schappe, Timothy; Moore, Kristin; Han, Xianlin; Abumrad, Nada A.; Gross, Richard W.

2010-01-01

10

Folic acid and birth defect prevention  

MedlinePLUS

Prevention of birth defects with folic acid (folate) ... There is good evidence that taking folic acid before and during pregnancy can reduce the risk of certain birth defects ( spina bifida , anencephaly , and some heart defects). Experts recommend taking 400 ...

11

The role of dietary calcium concentration in the use of anionic salts to prevent parturient paresis in dairy cows.  

PubMed

The role of dietary calcium concentration during the feeding of anionic salts (AS) was reviewed. Hypocalcaemia is still the major cause of parturient paresis in dairy cows. Feeding AS is an established method for preventing severe hypocalcaemia by activating the calcium metabolism in the last two to three weeks before parturition by inducing a metabolic acidosis. In compensation for this acidosis, the organism increases the concentrations of ionised Ca [Ca2+] in the blood. This increase leads to an increasing excretion of calcium via the urine, which is ensued by an increased calcium absorption in the intestine. The ongoing metabolic acidosis changed the flux of Ca. The size of the Ca pool, however, remained unchanged. As the calcium metabolism is activated by AS, it seems necessary to increase the amount of calcium that is fed to the cows. Several studies examined the impact of different dietary calcium concentrations on the acid-base balance and the calcium metabolism in cows fed anionic salts. The study designs vary concerning the amounts of calcium fed and the use of pregnant or non-pregnant cows. Only one study combined the feeding of AS with a very low amount of calcium, which fell below the daily requirements of pregnant cows in the last three weeks before parturition. In this study, the calcium balance post partum was better in the cows that were administered AS and a high calcium diet. In the other studies, the amount of calcium in the different experimental groups and the difference between the amounts of calcium fed varied greatly. As far as it was monitored in the studies, the calcium concentration of the diet did not have a significant impact on the degree of acidosis induced by AS. In pregnant cows, no significant differences in the calcium concentration in serum or urine occurred before parturition. Some of the researchers found a lower incidence of parturient paresis when cows were fed a combination of AS and a higher amount of calcium, but some other researches did not. Interestingly, the parameters of bone metabolism did not change between experimental groups. According to what is currently known, the feeding of AS to transition cows should not be combined with a dietary calcium concentration that falls below the requirement of cows in this stage of lactation. On the other hand, there is no need to increase the Ca concentration. When AS are used the dietary calcium concentration should be between 9 g and 12 g/kg dry matter. Further research is needed to investigate the role of dietary calcium regarding the use of AS for improving Ca metabolism in dairy cows around parturition. PMID:18712261

Gelfert, Carl-Christian; Staufenbiel, Rudolf

2008-01-01

12

Method for evaluating acid-base properties of complex calcium greases  

Microsoft Academic Search

The active components that determine the properties of complex calcium greases are salts of fatty acids, together with unreacted acids and calcium hydroxide. The acid-base properties of the grease depend on the content of these components, in particular on the ratio of hydroxide constituents (basic salts of fatty acids, calcium hydroxide) and acidic constituents (acid soaps, fatty acids). In order

I. G. Dagaeva; V. A. Kuznetsov; V. P. Korolenko; M. B. Nakonechnaya

1974-01-01

13

Diet Acids and Alkalis Influence Calcium Retention in Bone  

Microsoft Academic Search

:   The urine-acidifying properties of food constituents depend on their content of non-oxidizable acids or precursors. Acidifying\\u000a constituents such as animal proteins may negatively affect calcium metabolism and accelerate bone resorption, thus representing\\u000a an aggravating factor for osteoporosis. This four-period, double-crossover study investigated whether a diet intervention\\u000a specifically focused on acid load could modify calcium metabolism in humans. Eight healthy

T. Buclin; M. Cosma; M. Appenzeller; A.-F. Jacquet; L. A. Décosterd; J. Biollaz; P. Burckhardt

2001-01-01

14

Arachidonic acid and calcium signals in human breast tumor-derived endothelial cells: a proteomic study.  

PubMed

Intracellular calcium signals activated by growth factors in endothelial cells during angiogenesis regulate cytosolic and nuclear events involved in survival, proliferation and motility. Among the intracellular messengers released upon proangiogenic stimulation, arachidonic acid (AA) and its metabolites play a key role, and their effects are strictly related to calcium homeostasis. In human breast tumor-derived endothelial cells (B-TECs) AA stimulates proliferation and tubulogenesis in a calcium-dependent way. Here, to characterize the proteins whose expression is regulated by AA-induced calcium entry, we used a proteomic approach (two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization mass spectrometry, 2-DE and MALDI-MS) and we compared the proteomes of B-TECs stimulated with AA in presence or in absence of calcium entry (with addition to the culture medium of the calcium chelator EGTA, which completely prevents calcium fluxes throughout the plasma membrane). We found that six proteins increased their levels of expression, all higher when AA-induced calcium entry was abolished. These proteins have been identified by mass spectrometry and database search, and their potential roles in AA-stimulated pathway and in angiogenesis are discussed. PMID:19769547

Antoniotti, Susanna; Fattori, Paolo; Tomatis, Cristiana; Pessione, Enrica; Munaron, Luca

2009-01-01

15

Folic Acid Helps Prevent Neural Tube Defects  

MedlinePLUS

... What's this? Submit Button CDC Features Folic Acid Helps Prevent Neural Tube Defects Language: English Español (Spanish) ... Submit Button Language: English Español (Spanish) File Formats Help: How do I view different file formats (PDF, ...

16

Original article Acid gelation of colloidal calcium phosphate-  

E-print Network

of 45% total Ca and 30% total phosphorus, to an increase in sodium content and pH of milk, to lower, especially for -casein. The pH value at which the milk sample begins to gel increased for low mineral of acid gels. colloidal calcium phosphate / CCP / acid milk gel / dialysis ­ 90 °C 10 min pH

Paris-Sud XI, Université de

17

Lithium prevents early cytosolic calcium increase and secondary injurious calcium overload in glycolytically inhibited endothelial cells  

SciTech Connect

Highlights: •We investigate free calcium as a central signalling element in endothelial cells. •Inhibition of glycolysis with 2-deoxy-D-glucose reduces cellular ATP. •This manoeuvre leads to a biphasic increase and overload of free calcium. •Pre-treatment with lithium for 24 h abolishes both phases of the calcium increase. •This provides a new strategy to protect endothelial calcium homeostasis and barrier function. -- Abstract: Cytosolic free calcium concentration ([Ca{sup 2+}]{sub i}) is a central signalling element for the maintenance of endothelial barrier function. Under physiological conditions, it is controlled within narrow limits. Metabolic inhibition during ischemia/reperfusion, however, induces [Ca{sup 2+}]{sub i} overload, which results in barrier failure. In a model of cultured porcine aortic endothelial monolayers (EC), we addressed the question of whether [Ca{sup 2+}]{sub i} overload can be prevented by lithium treatment. [Ca{sup 2+}]{sub i} and ATP were analysed using Fura-2 and HPLC, respectively. The combined inhibition of glycolytic and mitochondrial ATP synthesis by 2-desoxy-D-glucose (5 mM; 2-DG) plus sodium cyanide (5 mM; NaCN) caused a significant decrease in cellular ATP content (14 ± 1 nmol/mg protein vs. 18 ± 1 nmol/mg protein in the control, n = 6 culture dishes, P < 0.05), an increase in [Ca{sup 2+}]{sub i} (278 ± 24 nM vs. 71 ± 2 nM in the control, n = 60 cells, P < 0.05), and the formation of gaps between adjacent EC. These observations indicate that there is impaired barrier function at an early state of metabolic inhibition. Glycolytic inhibition alone by 10 mM 2-DG led to a similar decrease in ATP content (14 ± 2 nmol/mg vs. 18 ± 1 nmol/mg in the control, P < 0.05) with a delay of 5 min. The [Ca{sup 2+}]{sub i} response of EC was biphasic with a peak after 1 min (183 ± 6 nM vs. 71 ± 1 nM, n = 60 cells, P < 0.05) followed by a sustained increase in [Ca{sup 2+}]{sub i}. A 24-h pre-treatment with 10 mM of lithium chloride before the inhibition of ATP synthesis abolished both phases of the 2-DG-induced [Ca{sup 2+}]{sub i} increase. This effect was not observed when lithium chloride was added simultaneously with 2-DG. We conclude that lithium chloride abolishes the injurious [Ca{sup 2+}]{sub i} overload in EC and that this most likely occurs by preventing inositol 3-phosphate-sensitive Ca{sup 2+}-release from the endoplasmic reticulum. Though further research is needed, these findings provide a novel option for therapeutic strategies to protect the endothelium against imminent barrier failure.

Bosche, Bert, E-mail: bert.bosche@uk-essen.de [Department of Neurology, University of Duisburg-Essen (Germany) [Department of Neurology, University of Duisburg-Essen (Germany); Max Planck Institute for Neurological Research with Klaus-Joachim-Zülch Laboratories of the Max Planck Society and the Medical Faculty of the University of Cologne (Germany); Schäfer, Matthias, E-mail: matthias.schaefer@sanofi.com [Institute of Physiology, Justus-Liebig-University Giessen (Germany)] [Institute of Physiology, Justus-Liebig-University Giessen (Germany); Graf, Rudolf, E-mail: rudolf.graf@nf.mpg.de [Max Planck Institute for Neurological Research with Klaus-Joachim-Zülch Laboratories of the Max Planck Society and the Medical Faculty of the University of Cologne (Germany)] [Max Planck Institute for Neurological Research with Klaus-Joachim-Zülch Laboratories of the Max Planck Society and the Medical Faculty of the University of Cologne (Germany); Härtel, Frauke V., E-mail: frauke.haertel@tu-dresden.de [Institute of Physiology, Medical Faculty Carl Gustav Carus, Technical University Dresden (Germany); Schäfer, Ute, E-mail: ute.schaefer@medunigraz.at [Research Unit for Experimental Neurotraumatology, Medical University of Graz (Austria)] [Research Unit for Experimental Neurotraumatology, Medical University of Graz (Austria); Noll, Thomas, E-mail: thomas.noll@tu-dresden.de [Institute of Physiology, Medical Faculty Carl Gustav Carus, Technical University Dresden (Germany)] [Institute of Physiology, Medical Faculty Carl Gustav Carus, Technical University Dresden (Germany)

2013-05-03

18

40 CFR 721.10382 - Diphosphoric acid, calcium salt (1:1).  

...2014-07-01 false Diphosphoric acid, calcium salt (1:1). 721.10382 Section... § 721.10382 Diphosphoric acid, calcium salt (1:1). (a) Chemical substance...substance identified as diphosphoric acid, calcium salt (1:1) (PMN...

2014-07-01

19

40 CFR 721.10382 - Diphosphoric acid, calcium salt (1:1).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Diphosphoric acid, calcium salt (1:1). 721.10382 Section... § 721.10382 Diphosphoric acid, calcium salt (1:1). (a) Chemical substance...substance identified as diphosphoric acid, calcium salt (1:1) (PMN...

2012-07-01

20

40 CFR 721.10382 - Diphosphoric acid, calcium salt (1:1).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Diphosphoric acid, calcium salt (1:1). 721.10382 Section... § 721.10382 Diphosphoric acid, calcium salt (1:1). (a) Chemical substance...substance identified as diphosphoric acid, calcium salt (1:1) (PMN...

2013-07-01

21

Ferulic acid prevents cerebral ischemic injury-induced reduction of hippocalcin expression.  

PubMed

Intracellular calcium overload is a critical pathophysiological factor in ischemic injury. Hippocalcin is a neuronal calcium sensor protein that buffers intracellular calcium levels and protects cells from apoptotic stimuli. Ferulic acid exerts a neuroprotective effect in cerebral ischemia through its anti-oxidant and anti-inflammation activity. This study investigated whether ferulic acid contributes to hippocalcin expression during cerebral ischemia and glutamate exposure-induced neuronal cell death. Rats were immediately treated with vehicle or ferulic acid (100 mg/kg, i.v.) after middle cerebral artery occlusion (MCAO). Brain tissues were collected 24 h after MCAO and followed by assessment of cerebral infarct. Ferulic acid reduced MCAO-induced infarct regions. A proteomics approach elucidated a decrease in hippocalcin in MCAO-operated animals, ferulic acid attenuates the injury-induced decrease in hippocalcin expression. Reverse transcription-polymerase chain reaction and Western blot analyses confirmed that ferulic acid prevents the injury-induced decrease in hippocalcin. In cultured HT22 hippocampal cells, glutamate exposure increased the intracellular Ca(2+) levels, whereas ferulic acid attenuated this increase. Moreover, ferulic acid attenuated the glutamate toxicity-induced decrease in hippocalcin expression. These findings can suggest the possibility that ferulic acid exerts a neuroprotective effect through modulating hippocalcine expression and regulating intracellular calcium levels. PMID:23401261

Koh, Phil-Ok

2013-07-01

22

Detection of bound phenolic acids: prevention by ascorbic acid and ethylenediaminetetraacetic acid of degradation of phenolic acids during alkaline hydrolysis  

Microsoft Academic Search

The experimental conditions commonly used to detect bound phenolic acids by alkaline hydrolysis result in loss of several phenolic acids, particularly dihydroxy-derivatives (caffeic acid, dihydrocaffeic acid, homogentisic acid). In this study we show that the addition of ascorbic acid, a strong antioxidant, and ethylenediaminetetraacetic acid, a metal chelator, totally prevent the loss of phenolic acids during alkaline hydrolysis. In these

M Nardini; E Cirillo; F Natella; D Mencarelli; A Comisso; C Scaccini

2002-01-01

23

Calcium phosphate: an alternative calcium compound for dietary prevention of colon cancer? A study on intestinal and faecal parameters in healthy volunteers.  

PubMed

In an effort to reduce the risk of colorectal cancer development, oral calcium carbonate supplementation has been used in previous studies for the precipitation of cytotoxic bile acids and fatty acids. In human intervention trials its effect on mucosal hyperproliferation in the colorectum has not always been satisfactory. Because the complexation of calcium and bile acids requires the formation of calcium phosphate, we performed an intervention study in 14 healthy volunteers, giving them 1,500 mg calcium as Ca3(PO4)2 for 1 week. The effects of tricalcium phosphate on luminal and faecal parameters of cytolytic activity were evaluated before, during, and after calcium phosphate supplementation. The cytolytic activity of faecal water and intestinal alkaline phosphatase activity in faecal water were not affected by supplemental calcium phosphate. In duodenal bile, the proportion of cholic acid tended to increase, whereas that of chenodeoxycholic acid tended to decrease during calcium phosphate supplementation. Neither concentrations of total and individual faecal bile acids, nor that of faecal fat were affected during calcium phosphate supplementation. It is suggested that, although phosphate is involved in bile acid precipitation, phosphate competes for calcium in the binding of fatty acids. This might possibly explain the unchanged cytolytic potency of faecal water, and therefore does not make tricalcium phosphate a suitable calcium compound for dietary intervention. PMID:8401176

Cats, A; Mulder, N H; de Vries, E G; Oremus, E T; Kreumer, W M; Kleibeuker, J H

1993-09-01

24

Abscisic acid controls calcium-dependent egress and development in Toxoplasma gondii  

PubMed Central

Calcium controls a number of critical events including motility, secretion, cell invasion, and egress by protozoan parasites 1. Compared to animal 2 and plant cells 3, the molecular mechanisms that govern calcium signaling in parasites are poorly understood. Here we demonstrate that the production of the phytohormone abscisic acid (ABA) controls calcium signaling within the apicomplexan parasite Toxoplasma gondii, an important human pathogen. In plants, ABA controls a number of important events including environmental stress responses, embryo development, and seed dormancy 4,5. ABA induces production of the second-messenger cyclic ADP ribose (cADPR), which controls release of intracellular calcium stores in plants 6. cADPR also controls intracellular calcium release in the protozoan parasite T. gondii 7,8; however, previous studies have not revealed the molecular basis of this pathway9. Addition of exogenous ABA induced formation of cADPR in T. gondii, stimulated calcium-dependent protein secretion, and induced parasite egress from the infected host cell in a density-dependent manner. Production of endogenous ABA within the parasite was confirmed by HPLC purification and GC-MS analysis. Selective disruption of ABA synthesis by the inhibitor fluridone (FLU) delayed egress and induced development of the slow-growing, dormant cyst stage of the parasite. Thus, ABA-mediated calcium signaling controls the decision between lytic and chronic stage growth, a developmental switch that is central in pathogenesis and transmission. The pathway for ABA production was likely acquired with an algal endosymbiont that was retained as a non-photosynthetic plastid known as the apicoplast. The plant-like nature of this pathway may be exploited therapeutically as shown by the ability of a specific inhibitor of ABA synthesis to prevent toxoplasmosis in the mouse model. PMID:18185591

Nagamune, Kisaburo; Hicks, Leslie M.; Fux, Blima; Brossier, Fabien; Chini, Eduardo N.; Sibley, L. David

2010-01-01

25

Reduced endoplasmic reticulum luminal calcium links saturated fatty acid-mediated endoplasmic reticulum stress and cell death in liver cells.  

PubMed

Chronic exposure to elevated free fatty acids, in particular long chain saturated fatty acids, provokes endoplasmic reticulum (ER) stress and cell death in a number of cell types. The perturbations to the ER that instigate ER stress and activation of the unfolded protein in response to fatty acids in hepatocytes have not been identified. The present study employed H4IIE liver cells and primary rat hepatocytes to examine the hypothesis that saturated fatty acids induce ER stress via effects on ER luminal calcium stores. Exposure of H4IIE liver cells and primary hepatocytes to palmitate and stearate reduced thapsigargin-sensitive calcium stores and increased biochemical markers of ER stress over similar time courses (6 h). These changes preceded cell death, which was only observed at later time points (16 h). Co-incubation with oleate prevented the reduction in calcium stores, induction of ER stress markers and cell death observed in response to palmitate. Inclusion of calcium chelators, BAPTA-AM or EGTA, reduced palmitate- and stearate-mediated enrichment of cytochrome c in post-mitochondrial supernatant fractions and cell death. These data suggest that redistribution of ER luminal calcium contributes to long chain saturated fatty acid-mediated ER stress and cell death. PMID:19444596

Wei, Yuren; Wang, Dong; Gentile, Christopher L; Pagliassotti, Michael J

2009-11-01

26

Calcium ion binding to a soil fulvic acid using a donnan potential model  

USGS Publications Warehouse

Calcium ion binding to a soil fulvic acid (Armadale Bh Horizon) was evaluated over a range of calcium ion concentrations, from pH 3.8 to 7.3, using potentiometric titrations and calcium ion electrode measurements. Fulvic acid concentration was constant (100 milligrams per liter) and calcium ion concentration varied up to 8 X 10-4 moles per liter. Experiments discussed here included: (1) titrations of fulvic acid-calcium ion containing solutions with sodium hydroxide; and (2) titrations of fully neutralized fulvic acid with calcium chloride solutions. Apparent binding constants (expressed as the logarithm of the value, log ??app) vary with solution pH, calcium ion concentration, degree of acid dissociation, and ionic strength (from log ??app = 2.5 to 3.9) and are similar to those reported by others. Fulvic acid charge, and the associated Donnan Potential, influences calcium ion-fulvic acid ion pair formation. A Donnan Potential corrrection term allowed calculation of intrinsic calcium ion-fulvic acid binding constants. Intrinsic binding constants vary from 1.2 to 2.5 (the average value is about log??= 1.6) and are similar to, but somewhat higher than, stability constants for calcium ion-carboxylic acid monodentate complexes. ?? by Oldenbourg Wissenschaftsverlag, Mu??nchen.

Marinsky, J.A.; Mathuthu, A.; Ephraim, J.H.; Reddy, M.M.

1999-01-01

27

Soil-calcium depletion linked to acid rain and forest growth in the eastern United States  

USGS Publications Warehouse

Since the discovery of acid rain in the 1970's, scientists have been concerned that deposition of acids could cause depletion of calcium in forest soils. Research in the 1980's showed that the amount of calcium in forest soils is controlled by several factors that are difficult to measure. Further research in the 1990's, including several studies by the U.S. Geological Survey, has shown that (1) calcium in forest soils has decreased at locations in the northeastern and southeastern U.S., and (2) acid rain and forest growth (uptake of calcium from the soil by roots) are both factors contributing to calcium depletion.

Lawrence, Gregory B.; Huntington, T.G.

1999-01-01

28

The role of calcium channel blocking agents in the prevention of migraine.  

PubMed

Vascular headache pathophysiology and manifestations are reviewed along with the role that calcium channel blocking agents play in prevention of these vascular headaches. Of the calcium channel blockers presently marketed in the U.S., verapamil has been the most widely studied. Verapamil has been shown to produce a significant improvement in frequency and duration of migraine as compared with placebo. Calcium channel blocking agents that have been studied and used outside of the U.S. are flunarizine and nimodipine, both of which provide significant improvement in measures of migraine severity, duration, frequency, and other pain and severity indices. There have been no controlled trials comparing these agents with each other as with beta-blocking agents and other prophylactic agents presently marketed in the U.S. Calcium channel blocking agents may become the drugs of first choice in migraine prophylaxis due to their effectiveness and mild side effect profile. PMID:3284729

Schuler, M E; Goldman, M P; Munger, M A

1988-03-01

29

Phosphate decreases urine calcium and increases calcium balance: A meta-analysis of the osteoporosis acid-ash diet hypothesis  

PubMed Central

Background The acid-ash hypothesis posits that increased excretion of "acidic" ions derived from the diet, such as phosphate, contributes to net acidic ion excretion, urine calcium excretion, demineralization of bone, and osteoporosis. The public is advised by various media to follow an alkaline diet to lower their acidic ion intakes. The objectives of this meta-analysis were to quantify the contribution of phosphate to bone loss in healthy adult subjects; specifically, a) to assess the effect of supplemental dietary phosphate on urine calcium, calcium balance, and markers of bone metabolism; and to assess whether these affects are altered by the b) level of calcium intake, c) the degree of protonation of the phosphate. Methods Literature was identified through computerized searches regarding phosphate with surrogate and/or direct markers of bone health, and was assessed for methodological quality. Multiple linear regression analyses, weighted for sample size, were used to combine the study results. Tests of interaction included stratification by calcium intake and degree of protonation of the phosphate supplement. Results Twelve studies including 30 intervention arms manipulated 269 subjects' phosphate intakes. Three studies reported net acid excretion. All of the meta-analyses demonstrated significant decreases in urine calcium excretion in response to phosphate supplements whether the calcium intake was high or low, regardless of the degree of protonation of the phosphate supplement. None of the meta-analyses revealed lower calcium balance in response to increased phosphate intakes, whether the calcium intake was high or low, or the composition of the phosphate supplement. Conclusion All of the findings from this meta-analysis were contrary to the acid ash hypothesis. Higher phosphate intakes were associated with decreased urine calcium and increased calcium retention. This meta-analysis did not find evidence that phosphate intake contributes to demineralization of bone or to bone calcium excretion in the urine. Dietary advice that dairy products, meats, and grains are detrimental to bone health due to "acidic" phosphate content needs reassessment. There is no evidence that higher phosphate intakes are detrimental to bone health. PMID:19754972

Fenton, Tanis R; Lyon, Andrew W; Eliasziw, Michael; Tough, Suzanne C; Hanley, David A

2009-01-01

30

Direct Identification of the Calcium-Binding Amino Acid, gamma -carboxyglutamate, in Mineralized Tissue  

Microsoft Academic Search

A direct approach has been developed for quantitative identification of the calcium-binding amino acid, gamma -carboxyglutamate, in proteins. This should be advantageous for the study of numerous systems where specific roles for the binding of calcium or other divalent cations are suspected. Investigation of mineralized tissue, where calcium-binding proteins are implicated in the mineralization process, revealed that gamma -carboxyglutamate was

Peter V. Hauschka; Jane B. Lian; Paul M. Gallop

1975-01-01

31

Calcium  

MedlinePLUS

... of calcium dietary supplements are carbonate and citrate. Calcium carbonate is inexpensive, but is absorbed best when taken ... antacid products, such as Tums® and Rolaids®, contain calcium carbonate. Each pill or chew provides 200–400 mg ...

32

Surface modification of calcium-copper hydroxyapatites using polyaspartic acid  

NASA Astrophysics Data System (ADS)

Mixed calcium-copper hydroxyapatite (Ca-CuHAp), with general formula Ca(10-x)Cux(PO4)6(OH)2, where 0 ? x ? 0.75 was prepared in aqueous medium in the presence of different concentrations of poly-L-aspartic acid (PASP). XRD, IR, TG-DTA, TEM-EDX, AFM and chemical analyses were used to characterize the structure, morphology and composition of the products. All techniques show the formation of new hybrid compounds Ca-CuHAp-PASP. The presence of the grafting moiety on the apatitic material is more significant with increasing of copper amount and/or organic concentration in the starting solution. These increases lead to the affectation of apatite crystallinity. The IR spectroscopy shows the conservation of (Psbnd OH) band of (HPO4)2- groups, suggesting that PASP acid was interacted only with metallic cations of hydroxyapatite.

Othmani, Masseoud; Aissa, Abdallah; Bachoua, Hassen; Debbabi, Mongi

2013-01-01

33

Roles of oleic acid during micropore dispersing preparation of nano-calcium carbonate particles  

NASA Astrophysics Data System (ADS)

In the present work, nano-calcium carbonate powder was prepared by micropore dispersion method with assistance of oleic acid as surfactant. CO 2 gas was dispersed into the Ca(OH) 2/H 2O slurry via a glass micropore-plate with the diameter of micropore about 20 ?m. To investigate the effect of oleic acid on the size of CaCO 3 particles, different amount of oleic acid was added in Ca(OH) 2/H 2O slurry at 5 °C and 25 °C, respectively. XRD patterns show that cubic calcite is the only crystalline phase in all cases. ZPA data and TEM photo indicate that the average particle size synthesized at 5 °C without oleic acid is of about 40 nm, slightly smaller than that of prepared at 25 °C, and that the dispersity of sample prepared at 5 °C is better than that of 25 °C. When oleic acid is added in both temperatures, the average particle size decreases a little. FT-IR spectra demonstrate that oleic acid interacts with Ca 2+ and carbon-carbon double bond existed on the surface of particle. Consequently, two opposite roles of oleic acid during the process of preparation of nano-CaCO 3 were proposed, namely preventing nanoparticles from growing during reaction and making nanoparticles reunite to a certain extent after reaction.

Jiang, Jiuxin; Liu, Jie; Liu, Chang; Zhang, Gaowen; Gong, Xinghou; Liu, Jianing

2011-06-01

34

CO.sub.2 Pretreatment prevents calcium carbonate formation  

DOEpatents

Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with carbon dioxide. The carbon dioxide pretreatment is believed to convert the scale-forming components to the corresponding carbonate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 14 to about 68 atmospheres and a carbon dioxide partial pressure within the range from about 14 to about 34 atmospheres. Temperature during pretreatment will generally be within the range from about 100.degree. to about 200.degree. C.

Neavel, Richard C. (Baytown, TX); Brunson, Roy J. (Buffalo Grove, IL); Chaback, Joseph J. (Worthington, OH)

1980-01-01

35

The role of calcium in improving photosynthesis and related physiological and biochemical attributes of spring wheat subjected to simulated acid rain.  

PubMed

The response of photosynthesis parameters, catalase, superoxide dismutase and peroxidase activity, malondialdehyde, proline, chlorophyll, yield and yield components to foliar application of calcium and simulated acid rain in wheat were investigated. Foliar treatment of calcium led to significant increases in the photosynthesis rate, transpiration rate, stomatal conductance, proline, chlorophyll, yield and yield components in plants subjected to acid rain. Antioxidant enzyme activity and lipid peroxidation in the wheat leaves decreased because of calcium foliar application. Calcium hindered degradation of the rubisco subunits under acid rain treatment compared with water-treated plants. Results suggest that acid rain induces the production of free radicals resulting in lipid peroxidation of the cell membrane so that significant increase in antioxidant enzyme activity was observed. In addition, photosynthetic parameters i.e. photosynthesis rate, transpiration rate and stomatal conductance were drastically suppressed by acid rain. The cellular damage caused by free radicals might be reduced or prevented by a protective metabolism including antioxidative enzymes and calcium. We report that foliar application of calcium before acid rain may ameliorate the adverse effects of acid rain in wheat plants. PMID:24431486

Dolatabadian, Aria; Sanavy, Seyed Ali Mohammad Modarres; Gholamhoseini, Majid; Joghan, Aydin Khodaei; Majdi, Mohammad; Kashkooli, Arman Beyraghdar

2013-04-01

36

The impact of osteoporosis prevention programs on calcium intake: a systematic review.  

PubMed

Little is known about the dimensions of osteoporosis prevention programs essential to changing health behaviors. The purpose of this review was to determine the impact of select characteristics of structured osteoporosis prevention programs on calcium intake in women. This systematic review included 12 experimental and quasi-experimental studies conducted internationally with adult women participants. Studies were more likely to demonstrate differences when they were conducted outside the U.W.; participants had lower baseline calcium intake; and interventions were multi-dimensional and included factual information, skill training, and social contact delivered dynamically over time. The results document extensive variability across participants, programs, and measures. There is a need to document the source (total and sub-total) of calcium intake, to provide the necessary data to calculate effect sizes to enable comparison across studies, and to identify those moderating factors (such as menopausal status) that affect the ability to determine differences between sub-groups. Results indicate health behavior change is more likely to occur when patient-centered interventions designed to increase knowledge and health beliefs, skills and abilities, and social facilitation are delivered over time. There is an urgent need for the development and testing of new health behavior change theories, prevention programs, and delivery media to support and complement health care providers in the prevention and management of this common, debilitating condition. PMID:23314270

Ryan, P; Schlidt, A; Ryan, C

2013-06-01

37

Carboxylic Acid Ionophores as Probes of the Role of Calcium in Biological Systems  

NASA Technical Reports Server (NTRS)

The biological effects of calcium ionophores are described, focusing on arachidonic acid oxygenation, and the formation of a number of oxygenated metabolites of arachidonic acid. These metabolites are involved in a number of bodily functions, and their production may be regulated by calcium.

Reed, P. W.

1983-01-01

38

Comparative effects of oral aromatic and branched-chain amino acids on urine calcium and excretion  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aromatic amino acids (AAAs) bind to the calcium sensor receptor (CaR) but branched-chain amino acids (B-CAAs) do not; by binding to this receptor, AAAs have an increased potential to affect calcium homeostasis. This study was conducted to determine and compare the effects of AAAs and B-CAAs on calci...

39

Calcium antagonist verapamil prevented pulmonary arterial hypertension in broilers with ascites by arresting pulmonary vascular remodeling.  

PubMed

Calcium signaling has been reported to be involved in the pathogenesis of hypertension. Verapamil, one of the calcium antagonists, is used to characterize the role of calcium signaling in the development of pulmonary arterial hypertension syndrome in broilers. The suppression effect of verapamil on pulmonary arterial hypertension and pulmonary vascular remodeling was examined in broilers, from the age of 16 days to 43 days. Our results showed that oral administration of lower dose of verapamil (5 mg/kg body weight every 12 h) prevented the mean pulmonary arterial pressure, the ascites heart index and the erythrocyte packed cell volume of birds at low temperature from increasing, the heart rate from decreasing, and pulmonary arteriole median from thickening, and no pulmonary arteriole remodeling in broilers treated with the two doses of verapamil at low temperature was observed. Our results indicated that calcium signaling was involved in the development of broilers' pulmonary arterial hypertension, which leads to the development of ascites, and we suggest that verapamil may be used as a preventive agent to reduce the occurrence and development of pulmonary arterial hypertension in broilers. PMID:17320074

Yang, Ying; Qiao, Jian; Wang, Huiyu; Gao, Mingyu; Ou, Deyuan; Zhang, Jianjun; Sun, Maohong; Yang, Xin; Zhang, Xiaobo; Guo, Yuming

2007-04-30

40

Folic Acid for the Prevention of Infant Neural Tube Defects: U.S. Preventive Services Task Force Recommendation  

MedlinePLUS

Folic Acid for the Prevention of Infant Neural Tube Defects: U.S. Preventive Services Task Force Recommendation Summaries for Patients ... modern medicine. The full reports are titled “Folic Acid for the Prevention of Neural Tube Defects: U.S. ...

41

Omega3 Fatty Acids for Cardiovascular Disease Prevention  

Microsoft Academic Search

Opinion statement  Major dietary sources of omega-3 fatty acids are fish containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA),\\u000a as well as nuts, seeds, and vegetable oils containing ?-linolenic acid (ALA). Omega-3 fatty acids, especially those derived\\u000a from marine sources, may be a useful tool for the primary and secondary prevention of cardiovascular disease. Omega-3s exert\\u000a their cardioprotective effects through multiple

Andrew Paul DeFilippis; Michael J. Blaha; Terry A. Jacobson

2010-01-01

42

21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...  

Code of Federal Regulations, 2010 CFR

...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. (a) Identification...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

2010-04-01

43

21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...  

...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. (a) Identification...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

2014-04-01

44

21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...  

Code of Federal Regulations, 2011 CFR

...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. (a) Identification...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

2011-04-01

45

21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...  

Code of Federal Regulations, 2013 CFR

...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. (a) Identification...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

2013-04-01

46

21 CFR 872.3490 - Carboxymethylcellulose sodium and/or polyvinylmethylether maleic acid calcium-sodium double salt...  

Code of Federal Regulations, 2012 CFR

...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. 872.3490 Section...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive. (a) Identification...polyvinylmethylether maleic acid calcium-sodium double salt denture adhesive is a device...

2012-04-01

47

Calcium  

MedlinePLUS

Calcium is a mineral that is an essential part of bones and teeth. The heart, nerves, and blood-clotting systems also need calcium ... as well as the calcium-enriched citrus juices, mineral water, canned fish with bones, and soy products ...

48

Influence of calcium chloride on systemic acid-base status and calcium metabolism in dairy heifers.  

PubMed

Twenty heifers (12 Holsteins and 8 Jerseys) ranging from 15 to 22 mo of age (SD = 2.2 mo) and weighing 271 to 486 kg (SD = 72 kg) were offered diets containing 0, .5, 1, and 1.5% CaCl2 for 3 wk followed by a 1-wk readjustment period to evaluate the effect of CaCl2 on acid-base status, diuresis, and Ca metabolism. These evaluations were conducted under conditions simulating changes in dietary cation-anion balance that potentially can be utilized as prophylaxis for parturient paresis during transition from dry cow period to lactation. Free proton concentration in blood increased and blood bicarbonate decreased with increasing dietary CaCl2. Plasma protein and blood hematocrit were unaffected by dietary CaCl2. Plasma Ca and urinary hydroxyproline excretion also were unaffected, but urinary Ca excretion rose with increasing dietary CaCl2, possibly reflecting either increased bone mobilization or intestinal absorption of Ca. Elevating dietary Cl increased both plasma Cl and urinary Cl excretion. During the readjustment period, all differences caused by CaCl2 disappeared. Based on the responses of acid-base status and Ca metabolism to the different dietary concentrations of CaCl2, we suggest that feeding 1% CaCl2 to dry cows for 3 wk prepartum could be a suitable method to prevent parturient paresis without causing detrimental acid-base disturbances. PMID:1860981

Tucker, W B; Xin, Z; Hemken, R W

1991-04-01

49

Regional Intravenous Infusion of Calcium Gluconate for Hydrofluoric Acid Burns of the Upper Extremity  

Microsoft Academic Search

Study objective: To describe regional intravenous infusion of calcium gluconate as a therapy for hydrofluoric acid (HF) burns of the forearm, hand, or digits. Methods: This study describes seven patients with HF burns. Calcium gluconate, 10 mL of 10% solution with 30 to 40 mL normal saline solution, was injected intravenously into the affected limb using a Bier block technique.

Andis Graudins; Michael J Burns; Cynthia K Aaron

1997-01-01

50

Poly (vinylsulfonic acid) assisted synthesis of aqueous solution stable vaterite calcium carbonate nanoparticles.  

PubMed

Calcium carbonate nanoparticles of the vaterite polymorph were synthesized by combining CaCl2 and Na2CO3 in the presence of poly (vinylsulfonic acid) (PVSA). By studying the important experimental parameters we found that controlling PVSA concentration, reaction temperature, and order of reagent addition the particle size, monodispersity, and surface charge can be controlled. By increasing PVSA concentration or by decreasing temperature CCNPs with an average size from ?150 to 500 nm could be produced. We believe the incorporation of PVSA into the reaction plays a dual role to (1) slow down the nucleation rate by sequestering calcium and to (2) stabilize the resulting CCNPs as the vaterite polymorph, preventing surface calcification or aggregation into microparticles. The obtained vaterite nanoparticles were found to maintain their crystal structure and surface charge after storage in aqueous buffer for at least 5 months. The aqueous stable vaterite nanoparticles could be a useful platform for the encapsulation of a large variety of biomolecules for drug delivery or as a sacrificial template toward capsule formation for biosensor applications. PMID:24461857

Nagaraja, Ashvin T; Pradhan, Sulolit; McShane, Michael J

2014-03-15

51

Inhibition of calcium oxalate crystallization by glutamic acid: Different effects at low and high concentrations  

NASA Astrophysics Data System (ADS)

The effects of L-aspartic acid, alanine and L-glutamic acid on the crystallization of calcium oxalate were followed by two methods: measurements of the changes in calcium ion concentrations and determination of crystal size distribution in the calcium oxalate precipitate. The changes in calcium ion concentration were detected by a specific calcium electrode and are expressed as Discriminating Index (DI) values. Median size and number of crystals per milliliter were determined by Particle Data Counter. Glutamic acid in the range of 0-200 ppm was added to solutions of CaCl 2 which were subsequently mixed with solutions of Na 2C 2O 4 to yield CaC 2O 4 precipitation. At relatively high concentrations of glutamic acid, namely 20-200 ppm, the precipitation of calcium oxalate is retarded. However, at low concentrations, 2.5-20 ppm oxalate precipitation is enhanced. The two independent methods yield well-correlated results. Both L-aspartic acid and alanine did not affect the precipitation of calcium oxalate at similar experimental conditions.

Azoury, Reuven; Randolph, Alan D.; Drach, George W.; Perlberg, Saul; Garti, Nissim; Sarig, Sara

1983-11-01

52

Layered Calcium Structures of p-Phosphonic Acid O-Methyl-Calix[6]arene  

PubMed Central

Hexamethoxy-calix[6]arene has been fully functionalized with p-phosphonic acid groups on the upper rim in 57% yield over three steps, and has been authenticated in the solid state by X-ray diffraction as either a nitrate salt or one of two calcium complexes. The latter differ by the ratio of calcium ions per calixarene, either 3:1 or 4:1. In both structures the coordination sphere of the calcium ions is made up of oxygen atoms from the phosphonic acid groups and from water of crystallization, as part of extended polymeric layers in the extended 3D packing. Hirshfeld surface analysis shows extensive O…H and O…Ca interactions for the phosphonic acid moieties in both calcium structures. MALDI-TOF MS of the hexaphosphonic acid shows nano-arrays consisting of up to a maximum of 28 calixarene units. PMID:20657793

Clark, Thomas E.; Martin, Adam; Makha, Mohamed; Sobolev, Alexandre N.; Su, Dian; Rohrs, Henry W.; Gross, Michael L.; Raston, Colin L.

2010-01-01

53

SEMI-BATCH PRECIPITATION OF CALCIUM SULFATE DIHYDRATE FROM CALCITE AND SULFURIC ACID  

E-print Network

SEMI-BATCH PRECIPITATION OF CALCIUM SULFATE DIHYDRATE FROM CALCITE AND SULFURIC ACID Frédéric BARD1 a calcite suspension to a sulfuric acid solution from industrial waste. The morphology of the precipitated, sulfuric acid, industrial waste. 1. INTRODUCTION Gypsum is a mineral compound of first importance

Paris-Sud XI, Université de

54

Protein adsorption characteristics of calcium hydroxyapatites modified with pyrophosphoric acids.  

PubMed

Protein adsorption characteristics of calcium hydroxyapatite (Hap) modified with pyrophosphoric acids (PP(a)) were examined. The PP(a) modified Hap particles (abbreviated as PP-Hap) possessed anchored polyphosphate (PP: P-{O-PO(OH)}(n)-OH) branches on their surfaces. The proteins of bovine serum albumin (BSA: isoelectric point (iep)=4.7, molecular mass (M(s))=67,200 Da, acidic protein), myoglobin (MGB: iep=7.0, M(s)=17,800 Da, neutral protein), and lysozyme (LSZ: iep=11.1, M(s)=14,600 Da, basic protein) were examined. The zeta potential (zp) of PP-Hap particles as a function of pH overlapped; zp-pH curves were independent of the concentration of pyrophosphoric acids (abbreviated as [PP(a)]) used for modifying Hap surface. The saturated amounts of adsorbed BSA (Delta n(ads)(BSA)) were increased three-fold by the surface modification with PP(a) though they were independent of the [PP(a)]. Furthermore, the fraction of BSA desorption was independent of the [PP(a)]. This enhancement of BSA adsorption onto the PP-Hap is due to the hydrogen bonding between oxygen and OH groups of the PP-branches and functional groups of BSA molecules. In the case of LSZ, a more higher adsorption enhancement was observed; the saturated amount of adsorbed LSZ (Delta n(ads)(LSZ)) for Hap modified at [PP(a)]=6 mmol/dm(3) was nine-fold than that for Hap unmodified. This remarkable adsorption enhancement was explained by a three-dimensional binding mechanism; LSZ molecules were trapped inside of the PP-branches. Hence, a fraction of LSZ desorption was decreased with an increase in the [PP(a)]; as more PP-branches are presented on the surface the higher retardation of LSZ desorption was induced. It was expected from their small size that MGB adsorb between the PP-branches as well as LSZ. However, the amounts of adsorbed MGB (Delta n(ads)(MGB)) did not vary and were independent of the [PP(a)] due to the small numbers of functional groups of MGB. In addition, no dependence of the fraction of MGB desorption on the [PP(a)] was observed. The results of zp for all the protein systems supported the mode of protein adsorption discussed. The anchored structure of the PP-branches developed on the Hap surface to provide three-dimensional protein adsorption spaces was proved by a comparative experiment that was elucidating the effect of pyrophosphate ions for BSA adsorption onto Hap. PMID:17399960

Kandori, Kazuhiko; Tsuyama, Shintaro; Tanaka, Hidekazu; Ishikawa, Tatsuo

2007-08-01

55

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

PubMed

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. PMID:25371160

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

2014-12-01

56

[Preventive and remineralization effect over incipient lesions of caries decay by phosphopeptide-amorphous calcium phosphate].  

PubMed

INTRODUCTION. Dental caries continues to affect a large percentage of Mexican children and currently advises that if diagnosed at an early stage can be reversed with minimally invasive treatments. The casein phosphopeptide amorphous calcium phosphate known as CPP-ACP is a phosphoprotein capable of releasing calcium and phosphate ions in the oral environment promoting remineralization. OBJECTIVE. To evaluate the effect of CPP-ACP with fluoride added in a scholar preventive program. MATERIAL AND METHODS. A cuasi- experimental study was conducted in 104 schools of six years old. The children were classified into three groups and received six months biweekly applications of different treatments: casein phosphopeptide amorphous calcium phosphate added fluoride (CPP-ACPF), sodium fluoride (NaF) and a control group. Clinical evaluation was performed with the laser fluorescence technique (Diagnodent model 2095). 1340 teeth were included: 294 teeth with incipient lesions and 1,046 healthy teeth. Statistical tests of ?2 y Mc Nemar were used. RESULTS. In the group that received the application of CPP-ACPF, 38% of incipient carious lesions were remineralizing compared with 21% in the group receiving the NaF (p < 0.001) and 15% in the control group (p < 0.0001) The percentage of teeth free of caries were preserved in the therapy group phosphoprotein was the biggest. This group also showed the lower proportion of deep carious lesion development (p < 0.0001). CONCLUSION. The application biweekly for six months of CPP-ACPF showed a protective and remineralizing effect on incipient carious lesions. His action was better than the application of NaF. However, to reduce the impact from dental caries in schoolchildren is important to have a comprehensive preventive approach that includes promoting self-care, as well as the application of sealants. PMID:24960324

Juárez-López, María Lilia Adriana; Hernández-Palacios, Rosa Diana; Hernández-Guerrero, Juan Carlos; Jiménez-Farfán, Dolores; Molina-Frechero, Nelly

2014-01-01

57

Oleanolic acid induces relaxation and calcium-independent release of endothelium-derived nitric oxide  

PubMed Central

Background and purpose: The present study investigated the mechanisms by which oleanolic acid, a component of olive oil, increases release of nitric oxide (NO). Experimental approach: Measurements of isometric tension, NO concentration, or endothelial cell calcium were made in rat isolated mesenteric arteries. Immunoblotting for endothelial NOS (eNOS) and Akt kinase were performed in primary cultures of human umbilical vein endothelial cells (HUVECs). Key results: Oleanolic acid (3–30??M) evoked endothelium-dependent relaxations in noradrenaline-contracted rat superior and small mesenteric arteries. In rat superior mesenteric arteries, oleanolic acid induced simultaneous increases in NO concentration and relaxation, and these responses were inhibited by an inhibitor of NOS, asymmetric dimethyl-L-arginine (300??M) and by the NO scavenger, oxyhaemoglobin (10??M). Oleanolic acid-evoked NO increases were not reduced in Ca2+-free solution and in the presence of an inhibitor of endoplasmic reticulum calcium-ATPase, thapsigargin (1??M). Oleanolic acid evoked relaxation without changes in endothelial cell calcium, but decreased smooth muscle calcium in arterial segments. Oleanolic acid failed to increase calcium in HUVECs, but increased time-dependently phosphorylation of Akt kinase at Serine473 (Akt-Ser473) and eNOS at Serine1177 (eNOS-Ser1177), which was attenuated by inhibitors of phosphoinositide-3-kinase. Conclusions and implications: This study provides direct evidence that a component of olive oil, oleanolic acid, activated endothelium-dependent release of NO and decreased smooth muscle cell calcium followed by relaxation. The oleanolic acid-evoked endothelium-derived NO release was independent of endothelial cell calcium and involved phosphoinositide-3-kinase-dependent phosphorylation of Akt-Ser473 followed by phosphorylation of eNOS-Ser1177. PMID:18622409

Rodriguez-Rodriguez, R; Stankevicius, E; Herrera, M D; Østergaard, L; Andersen, M R; Ruiz-Gutierrez, V; Simonsen, U

2008-01-01

58

Low-dose calcium supplementation for preventing pre-eclampsia: a systematic review and commentary  

PubMed Central

Background Epidemiological data link low dietary calcium with pre-eclampsia. Current recommendations are for 1.5–2 g/day calcium supplementation for low-intake pregnant women, based on randomised controlled trials of ?1 g/day calcium supplementation from 20 weeks of gestation. This is problematic logistically in low-resource settings; excessive calcium may be harmful; and 20 weeks may be too late to alter outcomes. Objectives To review the impact of lower dose calcium supplementation on pre-eclampsia risk. Search strategy and selection criteria We searched PubMed and the Cochrane Pregnancy and Childbirth Group trials register. Data collection and analysis Two authors extracted data from eligible randomised and quasi-randomised trials of low-dose calcium (LDC, <1 g/day), with or without other supplements. Main results Pre-eclampsia was reduced consistently with LDC with or without co-supplements (nine trials, 2234 women, relative risk [RR] 0.38; 95% confidence interval [95% CI] 0.28–0.52), as well as for subgroups: LDC alone (four trials, 980 women, RR 0.36; 95% CI 0.23–0.57]); LDC plus linoleic acid (two trials, 134 women, RR 0.23; 95% CI 0.09–0.60); LDC plus vitamin D (two trials, 1060 women, RR 0.49; 0.31–0.78) and a trend for LDC plus antioxidants (one trial, 60 women, RR 0.24; 95% CI 0.06–1.01). Overall results were consistent with the single quality trial of LDC alone (171 women, RR 0.30; 95% CI 0.06–1.38). LDC plus antioxidants commencing at 8–12 weeks tended to reduce miscarriage (one trial, 60 women, RR 0.06; 95% CI 0.00–1.04). Conclusions These limited data are consistent with LDC reducing the risk of pre-eclampsia; confirming this in sufficiently powered randomised controlled trials would have implications for current guidelines and their global implementation. PMID:24621141

Hofmeyr, GJ; Belizán, JM; von Dadelszen, P

2014-01-01

59

Catechin prevents the calcium oxalate monohydrate induced renal calcium crystallization in NRK-52E cells and the ethylene glycol induced renal stone formation in rat  

PubMed Central

Background Reactive oxygen species play important roles in renal calcium crystallization. In this study, we examined the effects of catechin, which have been shown to have antioxidant properties on the renal calcium crystallization. Methods In the vitro experiment, the changes of the mitochondrial membrane potential, expression of superoxide dismutase (SOD), 4-hydroxynonenal (4-HNE), cytochrome c, and cleaved caspase 3 were measured to show the effects of catechin treatment on the NRK-52E cells induced by calcium oxalate monohydrate (COM). In the vivo study, Sprague–Dawley rats were administered 1% ethylene glycol (EG) to generate a rat kidney stone model and then treated with catechin (2.5 and 10 mg/kg/day) for 14 days. The urine and serum variables were dected on 7 and 14 days after EG administration. The expression of cytochrome c, cleaved caspase 3, SOD, osteopontin (OPN), malondialdehyde (MDA), 8-hydroxy-2?-deoxyguanosine (8-OHdG) in kidney were measured. Furthermore, the mitochondrial microstructure in the kidney was also examined by transmission electron microscopy. Results Catechin treatment could prevent the changes in mitochondrial membrane potential and expression of SOD, 4-HNE, cytochrome c, and cleaved caspase 3 in NRK-52E cells induced by the COM. For the in vivo experiments, the EG administration induced renal calcium crystallization was also prevented by the catechin. The expression of SOD, OPN, MDA, OPN and 8-OHdG, were increased after EG administration and this increase was diminished by catechin. Moreover, catechin also prevented EG induced mitochondrial collapse in rat. Conclusions Catechin has preventive effects on renal calcium crystallization both in vivo and in vitro, and provide a potential therapeutic treatment for this disease. PMID:24044655

2013-01-01

60

Fabrication of calcium phosphate-calcium sulfate injectable bone substitute using hydroxy-propyl-methyl-cellulose and citric acid.  

PubMed

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate (CSD, CaSO4 x 2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid phase (20, 40 wt%). In each groups, the HPMC percentage was 0, 2, and 4 wt%. An increase in compressive strength due to changes in morphology was confirmed by scanning electron microscopy images. A good conversion rate of HAp at 20% citric acid was observed in the XRD profiles. In addition, HPMC was not obviously affected by apatite formation. However, both HPMC and citric acid increased the compressive strength of IBS. The maximum compressive strength for IBS was with 40% citric acid and 4% HPMC after 14 days of incubation in 100% humidity at 37 degrees C. PMID:20333539

Thai, Van Viet; Lee, Byong-Taek

2010-06-01

61

Ruminal biohydrogenation in Holstein cows fed soybean fatty acids as amides or calcium salts.  

PubMed

Fatty amides of high oleate fats and calcium salts of palm oil were reported to resist biohydrogenation by ruminal microorganisms. This study was conducted to determine whether converting polyunsaturated fat sources to amides and calcium salts had equal ability to resist biohydrogenation. A total mixed ration consisting of forage and concentrate contained (dry basis): 1) 2.45% soybean oil (SBO), 2) 2.75% calcium salt of SBO, 3) 2.75% amide of SBO, or 4) 2.75% of a mixture of the calcium salt and amide (80:20, wt/wt) of SBO. The 4 diets were fed ad libitum to 4 multiparous lactating Holstein cows fitted with ruminal cannulas in a 4 x 4 Latin square with 21-d periods. Omasal samples were taken to measure postruminal fatty acid content and determine the extent of ruminal biohydrogenation. Adding SBO to the diets as either calcium salts or amides increased omasal flow of C18:2 (n-6) from 25 to 39 g/d. Omasal flow of C18:1 increased from 36 to 49 g/d when SBO was fed to cows as calcium salts, but increased to 86 g/d when SBO was fed as amides. Adding the soybean amide to the diet more than doubled the delivery of C18:1 (n-9) to the omasum of lactating cows, but it also increased trans fatty acid production in the rumen accompanied by milk fat depression. In this study, calcium salts and amide derivatives of fatty acids were both effective in enhancing omasal flow of unsaturataed fatty acids in lactating dairy cows. Amides were more effective than calcium salts for increasing the postruminal flow of oleic acid. PMID:15259239

Lundy, F P; Block, E; Bridges, W C; Bertrand, J A; Jenkins, T C

2004-04-01

62

Arachidonic acid stimulates /sup 45/calcium efflux and HPL release in isolated trophoblast cells  

SciTech Connect

Previous investigations from this laboratory have indicated that arachidonic acid stimulates a rapid, dose-dependent and reversible increase in hPL release which is not dependent on cyclooxygenase or lipoxygenase metabolism. To investigate further the mechanism by which arachidonic acid stimulates the release of hPL, the effect of arachidonic acid on the release of /sup 45/Ca from perifused cells prelabelled with /sup 45/Ca was examined in an enriched cell culture population of term human syncytiotrophoblast. Arachidonic acid (10-100 ..mu..M) stimulated a dose-dependent, rapid, and reversible increase in the release of both /sup 45/Ca and hPL from the perifused placental cells. On the other hand, palmitic acid had little effect on either hPL release or /sup 45/Ca release even at concentrations as high as 100 ..mu..M. Ionophore A23187 (1-10..mu..M) also stimulated a dose-dependent and reversible increase in hPL release. Since arachidonic acid increases the mobilization of cellular calcium, as reflected by the increased /sup 45/calcium efflux, and since an increase in the intracellular calcium concentration appears to stimulate an increase in hPL release, these results suggest that the stimulation of hPL release by arachidonic acid may be due, at least in part, to the effects of the fatty acid on cellular calcium mobilization. 26 references, 5 figures.

Zeitler, P.; Murphy, E.; Handwerger, S.

1986-01-13

63

BENCH-SCALE EVALUATION OF CALCIUM SORBENTS FOR ACID GAS EMISSION CONTROL  

EPA Science Inventory

Calcium sorbents for acid gas emission control were evaluated for effectiveness in removing SO2/HCl and SO2/NO from simulated incinerator and boiler flue gases. All tests were conducted in a bench-scale reactor (fixed-bed) simulating fabric filter conditions in an acid gas remova...

64

Calcium.  

PubMed

This chapter describes the chemical and biological value of the calcium ion. In calcium chemistry, our main interest is in equilibria within static, nonflowing systems. Hence, we examined the way calcium formed precipitates and complex ions in solution. We observed thereafter its uses by humankind in a vast number of materials such as minerals, e.g., marble, concrete, mortars, which parallel the biological use in shells and bones. In complex formation, we noted that many combinations were of anion interaction with calcium for example in the uses of detergents and medicines. The rates of exchange of calcium from bound states were noted but they had little application. Calcium ions do not act as catalysts of organic reactions. In biological systems, interest is in the above chemistry, but extends to the fact that Ca2+ ions can carry information by flowing in one solution or from one solution to another through membranes. Hence, we became interested in the details of rates of calcium exchange. The fast exchange of this divalent ion from most organic binding sites has allowed it to develop as the dominant second messenger. Now the flow can be examined in vitro as calcium binds particular isolated proteins, which it activates as seen in physical mechanical changes or chemical changes and this piece-by-piece study of cells is common. Here, however, we have chosen to stress the whole circuit of Ca2+ action indicating that the cell is organized both at a basal and an activated state kinetic level by the steady state flow of the ion (see Fig. 11). Different time constants of exchange utilizing very similar binding constants lead to: 1) fast responses as in the muscle of an animal; or 2) slower change as in differentiation of an egg or seed. Many other changes of state may relate to Ca2+ steady-state levels of flow in the circuitry and here we point to two: 1) dormancy in reptiles and animals; and 2) sporulation in both bacteria and lower plants. In the other chapters of this volume many components of the overall circuitry will be described. The reader should try to marry these into the overall activity of the cell for on top of molecular biology there is the cooperative system molecular biology of cells. To give an analogy, whereas much can be understood from the analysis of the properties of single-isolated water molecules, even examining their interaction in ice, this study alone cannot lead to an appreciation of the melting or boiling points of bulk water. PMID:11833348

Williams, Robert J P

2002-01-01

65

Nicotinic acid modulates intracellular calcium concentration and disassembles the cytoskeleton  

PubMed Central

Nicotinic acid (NA), a member of the vitamin B family, is well known for its functions in the treatment and prevention of atherosclerosis due to decreasing plasma levels of low-density lipoprotein cholesterol. In recent years, the major side effect of NA, cutaneous flushing, has also attracted extensive attention. However, the effects of NA in other aspects of physiology or cell biology have remained elusive. The present study provided evidence that high concentrations of NA were able to first reduce and later elevate intracellular [Ca2+] in the NIH3T3 cell line. The reduction of the intracellular Ca2+ concentration was achieved within the initial 10 sec, and was preceded by a gradual elevation of intracellular [Ca2+]. Notably, marked accumulation of opaque materials in the perinuclear region was observed in NIH3T3 cells treated with 70 mM NA. Further analysis revealed that treatment with 70 mM NA for 1 h disassembled the microtubule and F-actin cytoskeleton systems and resulted in ?-tubulin degradation in an ubiquitin-proteasome-dependent manner. These data indicated that high concentrations of NA disrupted cytoskeleton structures, which may have contributed to minus end (nucleus region) to plus end (cell membrane region)-directed transport processes and resulted in the deposition of material in the perinuclear region. Artificially increasing [Ca2+] adding CaCl2 to the culture media effected the disassembly of F-actin, while it had no apparent effect on microtubules. These results suggested that the disruption of the cytoskeleton systems was not entirely due to the NA-induced elevation of [Ca2+]. Finally, microinjection of NA into xenopus embryos blocked the transport of melanosomes to the peripheral cellular area. In conclusion, the present study indicated that NA disassembles F-actin and microtubule systems, thereby blocking cytoskeleton-dependent intracellular transport. PMID:25241762

LI, JIEJING; LI, YANXI; ZHANG, PENGHUI; NIU, HUA; SHI, YU

2014-01-01

66

[Prevention of osteoporosis by foods and dietary supplements. The effect of fructooligosaccharides (FOS) on the calcium absorption and bone].  

PubMed

Fructooligosaccharides (FOS) are well known as prebiotics which improve intestinal microflaura. FOS also have increasing effect on the intestinal absorption of calcium (Ca), magnesium (Mg) and iron. These effects were inspected by many animal experiments and then by human studies. Especially, FOS clearly prevent the decrease of bone mineral density by gastrectomy in rats. In this report, we mainly explain the preventive effect of FOS on the bone of gastrectomized rats and introduce relationship between another food ingredient or exercise. PMID:17012821

Ohta, Atsutane

2006-10-01

67

Luteolin prevents uric acid-induced pancreatic ?-cell dysfunction  

PubMed Central

Abstract Elevated uric acid causes direct injury to pancreatic ?-cells. In this study, we examined the effects of luteolin, an important antioxidant, on uric acid-induced ?-cell dysfunction. We first evaluated the effect of luteolin on nitric oxide (NO) formation in uric acid-stimulated Min6 cells using the Griess method. Next, we performed transient transfection and reporter assays to measure transcriptional activity of nuclear factor (NF)-?B. Western blotting assays were also performed to assess the effect of luteolin on the expression of MafA and inducible NO synthase (iNOS) in uric acid-treated cells. Finally, we evaluated the effect of luteolin on uric acid-induced inhibition of glucose-stimulated insulin secretion (GSIS) in Min6 cells and freshly isolated mouse pancreatic islets. We found that luteolin significantly inhibited uric acid-induced NO production, which was well correlated with reduced expression of iNOS mRNA and protein. Furthermore, decreased activity of NF-?B was implicated in inhibition by luteolin of increased iNOS expression induced by uric acid. Besides, luteolin significantly increased MafA expression in Min6 cells exposed to uric acid, which was reversed by overexpression of iNOS. Moreover, luteolin prevented uric acid-induced inhibition of GSIS in both Min6 cells and mouse islets. In conclusion, luteolin protects pancreatic ?-cells from uric acid-induced dysfunction and may confer benefit on the protection of pancreatic ?-cells in hyperuricemia-associated diabetes. PMID:25050113

Ding, Ying; Shi, Xuhui; Shuai, Xuanyu; Xu, Yuemei; Liu, Yun; Liang, Xiubin; Wei, Dong; Su, Dongming

2014-01-01

68

The effects of hyaluronic acid, calcium hydroxide, and dentin adhesive on rat odontoblasts and fibroblasts.  

PubMed

The aim of this study was to investigate the effects and efficiency of pulp capping preparations based on hyaluronic acid, calcium hydroxide, and dentin adhesive on the pulp tissue of Sprague-Dawley rats. The rats were killed and extracted teeth sectioned transversely through the pulp. The slices were placed in a RPMI 1640 cell culture medium supplemented with 10 % foetal calf serum. During 14 days of cultivation cultures were treated with preparations that contained hyaluronic acid (Gengigel Prof®), and calcium hydroxide (ApexCal®), or with dentin adhesive (Excite®). Cellularity and viability of fibroblasts and odontoblasts was analysed using a haemocytometer. Hyaluronic acid proved most efficient and the least toxic for direct pulp capping. Even though calcium hydroxide and dentin adhesive demonstrated a higher degree of cytotoxicity, their effects were still acceptable in terms of biocompatibility. PMID:21705303

Bogovi?, Ana; Nižeti?, Jana; Gali?, Nada; Zelježi?, Davor; Micek, Vedran; Mladini?, Marin

2011-06-01

69

L-type voltage-gated calcium channels modulate kainic acid neurotoxicity in cerebellar granule cells.  

PubMed

This study reports on the regulation of kainate neurotoxicity in cerebellar granule cells by calcium entry through voltage-gated calcium channels and by calcium release from internal cellular stores. Kainate neurotoxicity was prevented by the AMPA selective antagonist LY 303070 (10 microM). Kainate neurotoxicity was potentiated by cadmium, a general voltage-gated calcium channel blocker, and the L-type voltage-gated calcium channel blocker nifedipine. The antagonists of intracellular Ca2+ ([Ca2+]i) release, thapsigargin and ryanodine, were also able to potentiate kainate neurotoxicity. Kainate treatment elevated [Ca2+]i concentration with a rapid initial increase that peaked at 1543 nM and then declined to plateau at approximately 400 nM. Nifedipine lowered the peak response to 764 nM and the plateau response to approximately 90 nM. Thapsigargin also lowered the kainate-induced increase in [Ca2+]i (640 nM peak, 125 nM plateau). The ryanodine receptor agonist caffeine eliminated the kainate-induced increase in [Ca2+]i, and reduced kainate neurotoxicity. Kainate neurotoxicity potentiated by nifedipine was not prevented by RNA or protein synthesis inhibitors, nor by the caspase inhibitors YVAD-CHO and DEVD-CHO. Neither DNA laddering nor the number of apoptotic nuclei were increased following treatment with kainate and nifedipine. Increased nuclear staining with the membrane impermeable dye propidium iodide was observed immediately following kainate treatment, indicating a loss of plasma membrane integrity. Thus, kainate neurotoxicity is prevented by calcium entry through L-type calcium channels. PMID:10320722

Leski, M L; Valentine, S L; Coyle, J T

1999-05-15

70

Are the anti-arrhythmic effects of omega-3 fatty acids due to modulation of myocardial calcium handling?  

PubMed Central

Both animal and clinical studies have demonstrated that omega-3 fatty acids have anti-arrhythmic properties. It has been suggested that these anti-arrhythmic effects are due to modulation of the activity of various myocardial calcium handling proteins such as ryanodine receptor (RyR), L-type calcium current and sodium/calcium exchanger. In this article, we review all the data available on the effects of omega-3 fatty acids on ventricular myocardial calcium handling. In addition we highlight some unanswered questions and discuss possible therapeutic benefits of omega-3 fatty acids. PMID:23060805

Sankaranarayanan, Rajiv; Venetucci, Luigi

2012-01-01

71

Effects of Intrathecally Administered Aminoglycoside Antibiotics, Calcium-Channel Blockers, Nickel and Calcium on Acetic Acid-Induced Writhing Test in Mice  

Microsoft Academic Search

1.Antinociceptive effects of intrathecally administered aminoglycoside antibiotics, calcium-channel blockers, nickel and calcium ions on the acetic acid–induced writhing test in mice were examined.2.Neomycin (0.5–20.0 ?g\\/mouse) gentamicin (5–40 ?g\\/mouse), nicardipine, diltiazem and verapamil (0.5–80.0 ?g\\/mouse) and calcium ions (0.02–1.0 ?mol\\/mouse) exerted a dose-dependent antinociceptive activity on the acetic acid–induced writhing test. Nickel ions ( 2.5, 5.0 and 10.0 ?mol\\/mouse) were found

Ahmet Do?rul; Özgür Ye?ilyurt

1998-01-01

72

Calcium in diet  

MedlinePLUS

... with calcium and prevent it from being absorbed. DIETARY SUPPLEMENTS Calcium is also found in many multivitamin-mineral supplements. The amount varies depending on the. supplement. Dietary supplements may contain only calcium or calcium with other ...

73

A biocompatible calcium salt of hyaluronic acid grafted with polyacrylic acid.  

PubMed

We have synthesized hyaluronic acid (HA) grafted with polyacrylic acid (PAA) via controlled radical polymerization (CRP) in aqueous media. The grafted HA (HA-g-PAA) showed slow degradation by hyaluronidase compared with unmodified HA as a result of the steric hindrance produced by grafted PAA, and PAA was detached by hydrolysis and enzymatic degradation by lipase. It formed an insoluble salt immediately after mixing with Ca(2+) by the binding between grafted PAA and Ca(2+). Both HA-g-PAA and its salt showed good biocompatibility, especially to mesothelial cells in vitro. Finally, they were administered into mice subcutaneously and intraperitoneally. The residue of the material was observed 7 days after subcutaneous administration, while the material was almost cleared from the peritoneum 7 days after intraperitoneal administration with or without Ca(2+). HA-g-PAA is expected to be applicable to medical uses such as drug delivery in the peritoneum and for materials preventing peritoneal adhesion. PMID:25498607

Nakagawa, Yoshiyuki; Nakasako, Satoshi; Ohta, Seiichi; Ito, Taichi

2015-03-01

74

Calcium antagonist verapamil prevented pulmonary arterial hypertension in broilers with ascites by arresting pulmonary vascular remodeling  

Microsoft Academic Search

Calcium signaling has been reported to be involved in the pathogenesis of hypertension. Verapamil, one of the calcium antagonists, is used to characterize the role of calcium signaling in the development of pulmonary arterial hypertension syndrome in broilers. The suppression effect of verapamil on pulmonary arterial hypertension and pulmonary vascular remodeling was examined in broilers, from the age of 16 days

Ying Yang; Jian Qiao; Huiyu Wang; Mingyu Gao; Deyuan Ou; Jianjun Zhang; Maohong Sun; Xin Yang; Xiaobo Zhang; Yuming Guo

2007-01-01

75

Solubility, inhibited growth and dissolution kinetics of calcium oxalate crystals in solutions, containing hippuric acid  

Microsoft Academic Search

An analysis of crystal growth and dissolution of slightly soluble salts in physiological solutions in the presence of complexing ions was carried out, simulating conditions typical in human urine. It was found that hippuric acid, a normal physiological constituent of urine, acts at increased concentrations as a dissolving agent with respect to calcium oxalate (CaOx) and CaOx calculi. The kinetics

I. Gutzow; S. Atanassova; G. Budevsky; K. Neykov

1993-01-01

76

Influence of maleic acid copolymers on calcium orthophosphates crystallization at low temperature  

NASA Astrophysics Data System (ADS)

The goal of this study was to investigate the maleic acid copolymers role on calcium orthophosphates crystallization at low temperature. In this respect, two maleic acid copolymers with different structures [poly(sodium maleate-co-vinyl acetate) and poly(sodium maleate-co-methyl methacrylate)] were used. The syntheses of the calcium orthophosphates in the absence and in the presence of the copolymers were performed through the wet chemical method using calcium nitrate, ammonium dihydrogen phosphate and ammonium hydroxide as reactants. The syntheses were monitored in situ by potentiometric and conductometric measurements. To ensure the transformation of less thermodynamically stable calcium orthophosphates into more stable forms, the samples were aged 30 days in mother solutions, at room temperature. The presence of the copolymers in the final products was evidenced by FTIR spectroscopy and thermogravimetric analysis. Scanning and transmission electron microscopy and laser light scattering measurements gave information about the composites morphology and the size of the formed structures. X-ray diffraction evidenced that, as a function of comonomer structure and of copolymer concentration, the products could contain hydroxyapatite with low crystallinity, calcium-deficient or carbonated hydroxyapatite. At high concentration of poly(sodium maleate-co-methyl methacrylate) the transformation of brushite into apatitic structures was inhibited.

Pelin, Irina M.; Popescu, Irina; Suflet, Dana M.; Aflori, Magdalena; Bulacovschi, Victor

2013-08-01

77

Coronary artery calcium and primary prevention risk assessment: What is the evidence?  

PubMed Central

Background While the Framingham Risk Score provides a reasonable estimation of risk in certain subgroups, the majority of MIs occur in individuals classified as low or moderate risk. Coronary Artery Calcium (CAC) testing provides an individualized measure of atherosclerotic burden that integrates an individual’s cumulative lifetime risk factor exposure that cannot be obtained from serum markers. Methods and Results We briefly summarize the existing evidence for the use of CAC scanning in primary prevention and performed a meta-analysis of the existing randomized controlled data investigating the impact of CAC screening on lifestyle modification, risk factors, and downstream testing. We identified four trials published between 2003 and 2011 with a total of 2,490 participants, >75% of whom came from the Early Identification of Subclinical Atherosclerosis by Noninvasive Imaging Research (EISNER) trial. Three of the trials reported a non-significant increase in smoking cessation in the scan versus no-scan group with a pooled mean of 1.15 (95% CI 0.77 – 1.71). A significant reduction in SBP and LDL was noted in the EISNER trial, but the pooled estimates were 0.23mmHg (95% CI ?2.25 – 2.71) and 0.23mg/dL (95% CI ?5.96 – 6.42), respectively. Only the EISNER trial reported medication usage according to CAC score. They found a higher CAC score associated with an increased prescription of lipid lowering medications (p=<0.001) and a CAC=0 associated with fewer prescriptions for lipid lowering medications (p=0.02). Conclusions Our meta-analysis highlights the paucity of randomized evidence linking CAC scanning to improved intermediate and hard outcomes in primary prevention. Future trials are urgently needed to determine the impact of CAC screening on lifestyle modification, risk factor modification, and downstream testing. PMID:22811506

Whelton, Seamus P.; Nasir, Khurram; Blaha, Michael J.; Gransar, Heidi; Metkus, Thomas S.; Coresh, Josef; Berman, Daniel S.; Blumenthal, Roger S.

2012-01-01

78

Influence of Urinary Sialic Acid on Calcium Oxalate Crystal Formation  

Microsoft Academic Search

Using seed crystal method, whole-urine method, and scanning electron microscopy, the inhibitory effects of sialic acid and osteopontin (OPN) on aggregation\\/growth of CaOx crystals were investigated. Using the seed crystal method, sialic acid showed an inhibitory effect on CaOx crystal aggregation\\/growth in a concentration-dependent manner, but almost no effect was observed using the whole-urine method. OPN showed an inhibitory effect

E. Konya; N. Amasaki; T. Umekawa; M. Iguchi; T. Kurita

2002-01-01

79

IMPACT OF AROMATIC VERSUS BRANCHED-CHAIN AMINO ACIDS ON CALCIUM EXCRETION, ABSORPTION, AND BONE TURNOVER – POTENTIAL ROLE OF THE CALCIUM SENSOR RECEPTOR  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aromatic amino acids (AAAs), but not branched-chain amino acids (B-CAAs), bind to the calcium sensor receptor (CaSR) in renal tissue and thus AAAs may have a greater calciuric action than B-CAAs (1). This study was done to determine and compare the effects of increasing intake of these two types of ...

80

Limited efficacy of calcium and magnesium in a porcine model of hydrofluoric acid ingestion  

Microsoft Academic Search

Objective  This investigation evaluated the effectiveness of calcium and magnesium in treating oral hydrofluoric acid (HF) poisoning.\\u000a \\u000a \\u000a \\u000a Methods  The controlled laboratory investigation used anesthetized pigs. Subjects received HF via NG tube, titrated to abolish electrocardiographic\\u000a abnormalities. The untreated group received saline infusion. The treatment group received serial injections of calcium chloride\\u000a (CaCl2) and magnesium chloride (MgCl2). A third group received oral infusions

Jason A. Coffey; Kori L. Brewer; Robert Carroll; John Bradfield; William J. Meggs

2007-01-01

81

Characterization of modified calcium-silicate cements exposed to acidic environment  

SciTech Connect

Portland cement which is used as a binder in concrete in the construction industry has been developed into a biomaterial. It is marketed as mineral trioxide aggregate and is used in dentistry. This material has been reported to be very biocompatible and thus its use has diversified. The extended use of this material has led to developments of newer versions with improved physical properties. The aim of this study was to evaluate the effect of acidic environments found in the oral cavity on fast setting calcium silicate cements with improved physical properties using a combination of techniques. Two fast setting calcium silicate cements (CSA and CFA) and two cement composites (CSAG and CFAG) were assessed by subjecting the materials to lactic acid/sodium lactate buffer gel for a period of 28 days. At weekly intervals the materials were viewed under the tandem scanning confocal microscope (TSM), and scanning electron microscope (SEM). The two prototype cements exhibited changes in their internal chemistry with no changes in surface characteristics. Since the changes observed were mostly sub-surface evaluation of surface characteristics of cement may not be sufficient in the determination of chemical changes occurring. - Research Highlights: {yields} An acidic environment affects modified fast setting calcium silicate-based cements. {yields} No surface changes are observed in acidic environment. {yields} An acidic environment causes sub-surface changes in the material chemistry which are only visible in fractured specimens. {yields} A combination of techniques is necessary in order to evaluate the chemical changes occurring.

Camilleri, Josette, E-mail: josette.camilleri@um.edu.mt

2011-01-15

82

Effects of acid deposition on calcium nutrition and health of Southern Appalachian spruce fir forests  

SciTech Connect

The role of acid deposition in the health of spruce fir forests in the Southern Appalachian Mountains has been investigated by a wide variety of experimental approaches during the past 10 years. These studies have proceeded from initial dendroecological documentation of altered growth patterns of mature trees to increasingly more focused ecophysiological research on the causes and characteristics of changes in system function associated with increased acidic deposition. Field studies across gradients in deposition and soil chemistry have been located on four mountains spanning 85 km of latitude within the Southern Appalachians. The conclusion that calcium nutrition is an important component regulating health of red spruce in the Southern Appalachians and that acid deposition significantly reduces calcium availability in several ways has emerged as a consistent result from multiple lines or research. These have included analysis of trends in wood chemistry, soil solution chemistry, foliar nutrition, gas exchange physiology, root histochemistry, and controlled laboratory and field studies in which acid deposition and/or calcium nutrition has been manipulated and growth and nutritional status of saplings or mature red spruce trees measured. This earlier research has led us to investigate the broader implications and consequences of calcium deficiency for changing resistance of spruce-fir forests to natural stresses. Current research is exploring possible relationships between altered calcium nutrition and shifts in response of Fraser fir to insect attack by the balsam wooly adelgid. In addition, changes in wood ultrastructural properties in relation to altered wood chemistry is being examined to evaluate its possible role in canopy deterioration, under wind and ice stresses typical of high elevation forests.

McLaughlin, S.B.; Wullschleger, S. [Oak Ridge National Lab., TN (United States); Stone, A. [Univ. of Tennessee, Knoxville, TN (United States); Wimmer, R. [Austrian Agricultural Univ., Vienna (Austria); Joslin, J.D.

1995-02-01

83

Filler modification for papermaking with starch/oleic acid complexes with the aid of calcium ions.  

PubMed

To mitigate the negative effect of filler addition on paper strength and improve filler retention, filler modification with hydrogen bonding polymers (e.g., starch) or their composites is an interesting research topic. Differing from previous reports, the concept related to the deposition of starch/oleic acid complexes on precipitated calcium carbonate (PCC) with the aid of calcium ions was demonstrated. The introduction of calcium ions resulted in effective starch deposition. As a result of filler modification, filler retention and the tensile strength of the filled paper were simultaneously improved essentially due to the aggregation of PCC particles in filler modification process as well as improved filler bondability. The concept demonstrated in this brief study may provide an alternative approach to filler bondability enhancement for improved papermaking performances. PMID:23987430

Huang, Xiujie; Shen, Jing; Qian, Xueren

2013-10-15

84

Interactions of calcium and fulvic acid at the goethite-water interface  

NASA Astrophysics Data System (ADS)

Interactions of calcium and fulvic acid (Strichen ) with the surface of goethite were studied with batch and titration experiments. The mutual influence of the interactions on the adsorption of fulvic acid, calcium ions and protons were examined. Adsorption of the fulvic acid to goethite decreased with increase in pH (pH range 3-11). Addition of Ca (1.0 mM) at intermediate and high pH significantly enhanced the adsorption of fulvic acid. Compared to the adsorption to pure goethite, the presence of fulvic acid enhanced the adsorption of Ca significantly. In comparison to the simple linear sum of Ca bound to fulvic acid and goethite, the interactions between goethite and fulvic acid led to a reduced adsorption of Ca at low pH and an enhanced adsorption at high pH. With the adsorption of fulvic acid, protons were released at low pH and coadsorbed at high pH. When Ca was added, fewer protons were released at low pH and fewer coadsorbed at high pH. The experimental results can be adequately described using a surface complexation model, the Ligand and Charge Distribution (LCD) model, in which the CD-MUSIC model for ion adsorption to mineral oxides and the NICA model for ion binding to humics are integrated. In the model calculations, adequate descriptions of the ternary system data (Ca-fulvic acid-goethite) were obtained with parameters derived from three binary systems (fulvic acid-goethite, Ca-goethite and Ca-fulvic acid) without further adjustment. The model calculations suggest that the interactions between Ca and fulvic acid at the surface of goethite are mainly due to the electrostatic effects.

Weng, Li Ping; Koopal, Luuk K.; Hiemstra, Tjisse; Meeussen, Johannes C. L.; Van Riemsdijk, Willem H.

2005-01-01

85

Lysosomal release of cathepsins causes ischemic damage in the rat hippocampal slice and depends on NMDA-mediated calcium influx, arachidonic acid metabolism, and free radical production.  

PubMed

NMDA-mediated calcium entry and reactive oxygen species (ROS) production are well-recognized perpetrators of ischemic neuronal damage. The current studies show that these events lead to the release of the protein hydrolase, cathepsin B, from lysosomes 2 h following 5-min oxygen-glucose deprivation in the rat hippocampal slice. This release reflects a lysosomal membrane permeabilization (LMP) and was measured as the appearance of diffuse immunolabeled cathepsin B in the cytosol of CA1 pyramidal neurons. Necrotic neuronal damage begins after the release of cathepsins and is prevented by inhibitors of either cathepsin B or D indicating that the release of cathepsins is an important mediator of severe damage. There was an increase in superoxide levels, measured by dihydroethidium fluorescence, at the same time as LMP and reducing ROS levels with antioxidants, Trolox or N-tert-butyl-alpha-phenyl nitrone, blocked LMP. Both LMP and ROS production were blocked by an NMDA channel blocker (MK-801) and by inhibitors of mitogen-activated protein kinase kinase (U0126), calcium-dependent/independent phospholipases A2 (methyl arachidonyl fluorophosphonate) but not calcium-independent phospholipases A2 (bromoenol lactone) and cyclooxygenase-2 (NS398). A cell-permeant specific inhibitor of calpain (PD150606) prevented LMP, but not ROS production. It is concluded that LMP results in part from calcium-initiated and extracellular signal-regulated kinase-initiated arachidonic acid metabolism, which produces free radicals; it also requires the action of calpain. PMID:18363826

Windelborn, James A; Lipton, Peter

2008-07-01

86

Hierarchical role of fetuin-A and acidic serum proteins in the formation and stabilization of calcium phosphate particles.  

PubMed

The serum protein fetuin-A is a potent systemic inhibitor of soft tissue calcification. Fetuin-A is highly effective in the formation and stabilization of protein-mineral colloids, referred to as calciprotein particles (CPPs). These particles ripen in vitro in a two-step process, indicated by a morphological conversion from spheres to larger prolate ellipsoids. Using a combined light scattering and electron microscopic imaging approach we determined that the second-stage particles resulted from a highly anisotropic outgrowth of the first-stage particles. Electron microscopy of ascites fluid from a patient with calcifying peritonitis revealed particles reminiscent of secondary CPPs. Thus, CPPs form in the body and undergo the two-step ripening at least in pathological conditions. Unlike in vitro generated CPPs, ascites-derived CPPs contained little fetuin-A but large amounts of albumin. This prompted us to study the role of fetuin-A combined with other serum proteins in CPP formation. Fetuin-A was indispensable for primary CPP formation. Albumin and acidic proteins in general greatly enhanced the fetuin-A triggered formation of secondary CPPs and, thus, substituted substantial amounts of fetuin-A without loss of inhibition of calcium phosphate precipitation. Thus, direct mineral deposition from solute in the body is unlikely even at low fetuin-A serum levels as long as sufficient bulk acidic protein is available. Collectively fetuin-A and other acidic bulk plasma proteins may be considered as mineral chaperones mediating the stabilization, safe transport, and clearance in the body of calcium and phosphate as colloidal complexes, thus, preventing ectopic calcification. PMID:18364352

Heiss, Alexander; Eckert, Thomas; Aretz, Anke; Richtering, Walter; van Dorp, Wim; Schäfer, Cora; Jahnen-Dechent, Willi

2008-05-23

87

Morphological modifications of electrodeposited calcium phosphate coatings under amino acids effect  

NASA Astrophysics Data System (ADS)

Calcium phosphate coatings are synthesized on titanium alloy (Ti6Al4V) substrates by pulsed electrodeposition. This work aims to observe the morphological modifications of the coating when an amino acid is added to the electrolytic solution used in the process. The effects of two amino acids (glutamic acid and aspartic acid) are studied at a low and a high concentration. The coating morphology is observed at a nanometer scale by field emission gun-scanning electron microscopy (FEG-SEM). The structural characterization of the coating is performed by Fourier transformed infrared spectroscopy (FT-IR), Raman spectroscopy and X-ray diffraction (XRD). Moreover, corrosion measurements of the prosthetic surfaces are carried out by potentiodynamic polarization experiments in a physiological solution named Dulbecco's modified eagle medium (DMEM). The results show that the addition of an amino acid to the electrolytic solution leads to the decrease of the size of the crystallites which compose the prosthetic calcium phosphate coating that becomes denser and less porous than the coatings obtained without amino acid. Consequently, the corrosion behavior of the prosthetic material immersed in DMEM is improved.

Drevet, R.; Lemelle, A.; Untereiner, V.; Manfait, M.; Sockalingum, G. D.; Benhayoune, H.

2013-03-01

88

The effect of biliary bile acid concentration and composition on the calcium level in human gallbladder bile.  

PubMed

We analyzed total and ionized calcium concentrations in gallbladder bile of 34 humans in four groups: 8 patients with no gallstone, 11 gallstone patients treated with no gallstone dissolution agents, 8 gallstone patients treated with chenodeoxycholic acid (CDCA) and 7 gallstone patients treated with ursodeoxycholic acid (UDCA). We found that total calcium level ranged from 1.40 to 8.01 mmol/liter, closely related to total bile acid concentration (r = 0.759). However, ionized calcium level was maintained in a narrow range of 0.25 to 1.23 mmol/liter and had no relation to total bile acid concentration. UDCA-rich bile showed relatively high level of ionized calcium. We performed ultrafiltration of bile with cut-off molecular weight 1,000 to investigate the interaction between biliary calcium and bile acid aggregates. The proportion of ultrafiltrated bile acid level to that in original bile in the UDCA group was statistically higher than the other groups. Relatively large percentage of smaller bile acid aggregates in UDCA-rich bile may impair its calcium solubility. PMID:8184404

Tamasawa, N; Yoneda, M; Makino, I; Takebe, K; Sone, K; Kogawa, R

1993-12-01

89

Increased biliary calcium in cholesterol and pigment gallstone disease: The role of altered bile acid composition  

Microsoft Academic Search

The present study was undertaken to define the relationship between calcium metabolism and bile acid composition in animal\\u000a models of diet induced cholesterol and pigment gallstones. Groups of prairie dogs were fed either a control non-lithogenic\\u000a chow (N=12), a 1.2% cholesterol enriched chow (N=6, XOL) for two weeks, or a high carbohydrate diet deficient in iron (N=6,\\u000a CHO-FeD), or a

Mohammad Z. AbedinO; Seth D. Strichadzab; Sarkis Festekdjiana; Joel J. Roslynab

1989-01-01

90

CITRIC ACID AS A SET RETARDER FOR CALCIUM ALUMINATE PHOSPHATE CEMENTS.  

SciTech Connect

Citric acid added as set retarder significantly contributed to enhancing the setting temperature and to extending the thickening time of a calcium aluminate phosphate (CaP) geothermal cement slurry consisting of calcium aluminate cement (CAC) as the base reactant and sodium polyphosphate (NaP) solution as the acid reactant. The set-retarding activity of citric acid was due to the uptake of Ca{sup 2+} ions from the CAC by carboxylic acid groups within the citric acid. This uptake led to the precipitation of a Ca-complexed carboxylate compound as a set-retarding barrier layer on the CAC grains' surfaces. However, this barrier layer was vulnerable to disintegration by the attack of free Ca{sup 2+} ions from CAC, and also to degradation at elevated temperature, thereby promoting the generation of exothermic energy from acid-base reactions between the CAC and NaP after the barrier was broken. The exothermic reaction energy that was promoted in this way minimized the loss in strength of the citric acid-retarded cement. The phase composition assembled in both retarded and non-retarded cements after autoclaving at 180 C encompassed three reaction products, hydroxyapatite (HOAp), hydrogrossular and boehmite, which are responsible for strengthening the autoclaved cement. The first two reaction products were susceptible to reactions with sulfuric acid and sodium sulfate to form crystalline bassanite scale as the corrosion product. The boehmite phase possessed a great resistance to acid and sulfate. Although the bassanite scales clinging to the cement's surfaces were the major factor governing the loss in weight, they served in protecting the cement from further acid- and sulfate-corrosion until their spallation eventually occurred. Nevertheless, the repetitive processes of HOAp and hydrogrossular {yields} bassanite {yields} spallation played an important role in extending the useful lifetime of CaP cement in a low pH environment at 180 C.

SUGAMA,T.; BROTHERS, L.E.

2005-01-01

91

Effect of glyceric acid calcium salt on the viability of ethanol-dosed gastric cells.  

PubMed

D-Glyceric acid (D-GA) calcium has been reported to accelerate ethanol oxidation in vivo in rats (Eriksson et al., Metabolism, 56, 895-898 (2007)). However, no other reports have shown that D-GA can reduce the harmful effects of ethanol. In this study, the effects of D-, L-, and DL-GA calcium on ethanol-dosed gastric cell viability were investigated using human gastric carcinoma cells (Kato III) and normal rat gastric mucosa cells (RGM1). Addition of 2% and 3 % ethanol to Kato III and RGM1 cells, respectively, decreased their cell viability by approximately 20-50 % after 24 or 72 h of cultivation. In 2 % ethanol-dosed Kato III cells cultivated for 24 h, addition of 0.002-20 µg/mL D- and L-GA calcium did not affect cell viability. Similarly, addition of less than 20 µg/mL DL-GA calcium did not affect cell viability. However, when 20 µg/mL DL-GA calcium was added, cell viability increased by 35.7 % after 72 h of incubation, compared to the viability of control cells without ethanol or GA. Addition of 20 µg/mL DL-GA calcium to 3 % ethanol-dosed RGM1 cells cultivated for 24 or 72 h also increased cell viability up to those observed in control cells. These results suggest that a racemic mixture of GA may have the strongest effect on enhancing the viability of ethanol-exposed cells. PMID:22027025

Habe, Hiroshi; Sato, Shun; Fukuoka, Tokuma; Kitamoto, Dai; Sakaki, Keiji

2011-01-01

92

Ascorbic Acid Prevents Increased Endothelial Permeability Caused by Oxidized Low Density Lipoprotein  

PubMed Central

Mildly oxidized low density lipoprotein (mLDL) acutely increases the permeability of the vascular endothelium to molecules that would not otherwise cross the barrier. We have shown that ascorbic acid tightens the permeability barrier in endothelial barrier in cells, so in this work we tested whether it might prevent the increase in endothelial permeability due to mLDL. Treatment of EA.hy926 endothelial cells with mLDL decreased intracellular GSH and activated the cells to further oxidize the mLDL. mLDL also increased endothelial permeability over 2 h to both inulin and ascorbate in cells cultured on semi-permeable filters. This effect was blocked by microtubule and microfilament inhibitors, but not by chelation of intracellular calcium. Intracellular ascorbate both prevented and reversed the mLDL-induced increase in endothelial permeability, an effect mimicked by other cell-penetrant antioxidants. These results suggest a role for endothelial cell ascorbate in ameliorating an important facet of endothelial dysfunction caused by mLDL. PMID:20815791

May, James M.; Qu, Zhi-chao

2013-01-01

93

Heat stability and acid gelation properties of calcium-enriched reconstituted skim milk affected by ultrasonication.  

PubMed

The aggregation of proteins after heating of calcium-fortified milks has been an ongoing problem in the dairy industry. This undesirable effect restricts the manufacture of calcium rich dairy products. To overcome this problem, a completely new approach in controlling the heat stability of dairy protein solutions, developed in our lab, has been employed. In this approach, high intensity, low frequency ultrasound is applied for a very short duration after a pre-heating step at ?70 °C. The ultrasound breaks apart whey/whey and whey/casein aggregates through the process of acoustic cavitation. Protein aggregates do not reform on subsequent post-heating, thereby making the systems heat stable. In this paper, the acid gelation properties of ultrasonicated calcium-enriched skim milks have also been investigated. It is shown that ultrasonication alone does not change the gelation properties significantly whereas a sequence of preheating (72 °C/1 min) followed by ultrasonication leads to decreased gelation times, decreased gel syneresis and increased skim milk viscosity in comparison to heating alone. Overall, ultrasonication has the potential to provide calcium-fortified dairy products with increased heat stability. However, enhanced gelation properties can only be achieved when ultrasonication is completed in conjunction with heating. PMID:24698480

Chandrapala, Jayani; Bui, Don; Kentish, Sandra; Ashokkumar, Muthupandian

2014-05-01

94

PREDICTING THE PERFORMANCE OF AN ELEVATED WATER TABLE FOR PREVENTING ACID  

E-print Network

PREDICTING THE PERFORMANCE OF AN ELEVATED WATER TABLE FOR PREVENTING ACID MINE DRAINAGE M. The effectiveness of an elevated water table in preventing acid mine drainage (AMD) can be quantified using diffusion de l'oxygène en milieu quasi saturé. Cette efficacité à empêcher le drainage minier acide (DMA

Aubertin, Michel

95

Survey of calcium supplementation to prevent preeclampsia: the gap between evidence and practice in Brazil  

PubMed Central

Background Preeclampsia is a major cause of maternal and perinatal morbidity and mortality worldwide and especially in Latin America. High quality evidence indicates that calcium supplementation during pregnancy significantly reduces the incidence of preeclampsia and its consequences, including severe maternal morbidity and death. Few studies have assessed the implementation of this intervention in clinical practice. The study aimed to assess the proportion of pregnant women who received calcium supplements in Brazilian public antenatal care clinics. Methods This cross-sectional study interviewed women waiting for antenatal care visits in 9 public clinics in 4 Brazilian cities in 2010-2012. Trained interviewers used a standardized anonymous questionnaire to collect socio demographic and obstetric data, information on ingestion of dairy products and on prescriptions received during current pregnancy. Results A total of 788 valid questionnaires were analyzed. Participants were young (mean age 25.9), mostly multiparous (71.3%) and in the 2nd or 3rd trimesters of pregnancy at the time of interview (87.6%). Only 5.1% (40/788) had received a prescription for calcium supplements. Based on their reported ingestion of dairy products, the mean daily dietary calcium intake of the participants was 210 (+ 265) mg/day and over 90% consumed less than 1 g of calcium/day. Conclusions Despite good quality evidence indicating the benefits of this practice especially for women with low calcium diets, less than 6% of a sample of women receiving antenatal care in Brazilian public clinics received a prescription for calcium supplements. There is an urgent need to upscale the implementation of this life-saving intervention. PMID:24215470

2013-01-01

96

On the coating of precipitated calcium carbonate with stearic acid in aqueous medium.  

PubMed

A series of experimental precipitated calcium carbonates (PCCs) coated with commercial stearic acid (stearin), with the coating amount of stearin added to the PCC particles ranging from 3 to 13.5 wt %, were prepared in aqueous medium and characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). FTIR and TGA results indicated that only calcium stearate is present without any free stearic acid left on the surface of the produced PCCs. It was also found that the calcium stearate formed on the coated surface is partially chemisorbed and partially physisorbed. Interestingly, the surface coverage of the chemisorbed stearate, determined by the DSC technique in about 3.25 wt %, was much lower than the theoretical full monolayer coverage (4.17 wt %) for the same set of particles. This result was confirmed by determining the amount necessary to cover the filler with a full monolayer of surfactant by means of a dissolution method where the amount of dissolved surface agent, after the coating reaction, was measured by gas chromatography (GC). In other words, a complete chemisorbed monolayer on the surface cannot be reached, even in the presence of an amount of stearate ions far in excess compared to those required by the stoichiometry. This can be explained by considering that the coating in aqueous medium is quite different from solvent or dry coating, since the process is controlled by micelle adsorption, followed by the collapse of micelles into double or multiple layers during the drying stage. PMID:20334413

Shi, Xuetao; Rosa, Roberto; Lazzeri, Andrea

2010-06-01

97

Antibiotic-loaded synthetic calcium sulfate beads for prevention of bacterial colonization and biofilm formation in periprosthetic infections.  

PubMed

Periprosthetic infection (PI) causes significant morbidity and mortality after fixation and joint arthroplasty and has been extensively linked to the formation of bacterial biofilms. Poly(methyl methacrylate) (PMMA), as a cement or as beads, is commonly used for antibiotic release to the site of infection but displays variable elution kinetics and also represents a potential nidus for infection, therefore requiring surgical removal once antibiotics have eluted. Absorbable cements have shown improved elution of a wider range of antibiotics and, crucially, complete biodegradation, but limited data exist as to their antimicrobial and antibiofilm efficacy. Synthetic calcium sulfate beads loaded with tobramycin, vancomycin, or vancomycin-tobramycin dual treatment (in a 1:0.24 [wt/wt] ratio) were assessed for their abilities to eradicate planktonic methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis relative to that of PMMA beads. The ability of the calcium sulfate beads to prevent biofilm formation over multiple days and to eradicate preformed biofilms was studied using a combination of viable cell counts, confocal microscopy, and scanning electron microscopy of the bead surface. Biofilm bacteria displayed a greater tolerance to the antibiotics than their planktonic counterparts. Antibiotic-loaded beads were able to kill planktonic cultures of 10(6) CFU/ml, prevent bacterial colonization, and significantly reduce biofilm formation over multiple days. However, established biofilms were harder to eradicate. These data further demonstrate the difficulty in clearing established biofilms; therefore, early preventive measures are key to reducing the risk of PI. Synthetic calcium sulfate loaded with antibiotics has the potential to reduce or eliminate biofilm formation on adjacent periprosthetic tissue and prosthesis material and, thus, to reduce the rates of periprosthetic infection. PMID:25313221

Howlin, R P; Brayford, M J; Webb, J S; Cooper, J J; Aiken, S S; Stoodley, P

2015-01-01

98

Habit modification of calcium carbonate in the presence of malic acid  

SciTech Connect

The ability of malic acid to control calcium carbonate morphology has been investigated by aging calcium chloride solution in the presence of urea in a 90 deg. C bath. Malic acid favors the formation of calcite. A transition from single block to aggregate with special morphology occurs upon increasing malic acid concentration. The morphological development of CaCO{sub 3} crystal obviously depends on the starting pH. CaCO{sub 3} crystal grows from spindle seed to dumbbell in the pH regime from 7 to 11; while it evolves from spindle seed, through peanut, to sphere at pH=11.5. Both dumbbell and sphere consist of rods that are elongated along c-axis and capped with three smooth, well-defined rhombic {l_brace}1 0 4{r_brace} faces. A tentative growth mechanism is proposed based on the fractal model suggested by R. Kniep and S. Busch [Angew. Chem. Int. Ed. Engl. 35 (1996) 2624]. - Graphical abstract: Dumbbell-like CaCO{sub 3} particles obtained in the presence of malic acid.

Mao Zhaofeng [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Huang Jianhua [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018 (China)], E-mail: jhhuang@zstu.edu.cn

2007-02-15

99

Preparation and characterization of uniform particles of flufenamic acid and its calcium and barium salts.  

PubMed

Uniform fully dispersed particles of flufenamic acid, a widely used anti-inflammatory drug, were prepared by two different methods. In the first one, the drug solution in organic solvents was added to a non-solvent (water or aqueous solutions of stabilizers); while in the second procedure the drug was precipitated by acidifying its basic aqueous solutions. In addition calcium and barium salts of uniform spherical particles were obtained by precipitation in aqueous basic solutions of the drug. These salts are supposed to improve the drug reactivity. The prepared dispersions of the drug and its salts were examined by scanning electron microscopy, X-ray diffractometry and electrophoresis. PMID:22703985

Mohamed, Amr Ali; Matijevi?, Egon

2012-09-01

100

Acid-induced release of curcumin from calcium containing nanotheranostic excipient.  

PubMed

Poor water solubility is believed one of the most critical problems of numerous promising pharmaceutical ingredients in their successful clinical utilization. Nanomedicine holds considerable promise to address this challenge, because it extends the therapeutic window of hydrophobic drugs through nanonization approach. Recently, the integration of diagnostic agents with smart therapeutic nanocarriers is also an emerging research arena to simultaneously visualize diseased tissues, achieve site specific drug release and track the impact of therapy. In this study, we have developed a biocompatible smart theranostic nanosystem which transports a highly promising hydrophobic drug (curcumin) in response to mildly acidic environment. As calcium is a main constituent of human body, hence we exploited the reversible calcium chelate formation tendency of divalent calcium to load and unload curcumin molecules. Moreover, an emerging T1 contrast agent is also tethered onto the surface of nanocarrier to realize MRI diagnosis application. In-vitro cell experiments revealed a significantly high chemotherapeutic efficiency of curcumin nanoformulation (IC50; 1.67 ?g/mL), whereas free curcumin was found ineffective at the corresponding concentration (IC50; 29.72 ?g/mL). MR imaging test also validated the performance of resulting system. Our strategy can be extended for the targeted delivery of other hydrophobic pharmaceutical ingredients. PMID:25025519

Wang, Aifei; Muhammad, Faheem; Qi, Wenxiu; Wang, Nan; Chen, Liang; Zhu, Guangshan

2014-08-27

101

Calcium carbonate breath test for non-invasive estimation of gastric acid secretion.  

PubMed

Gastric acid measurement is useful in assessing the effectiveness of antisecretory drugs, however, the conventional tests involve invasive nasogastric intubation. Orally administered ¹³C-labeled calcium carbonate (Ca¹³CO?) reacts with gastric acid to produce ¹³C-labeled carbon dioxide (¹³CO?), which is then excreted in the breath. The objective of this study was to evaluate the suitability of Ca¹³CO3 breath test for estimating gastric acid secretion in human noninvasively. First, the Ca¹³CO? breath test and the measurement of pooled gastric acid under a fasting condition were performed in 6 healthy volunteers to evaluate the correlation between the two parameters. Next, endoscopic gastric acid collection and the Ca¹³CO? breath test were performed on different days after pentagastrin injection in 20 subjects to evaluate the correlation between the tests and the reproducibility. Finally, the same studies were repeated in 4 subjects before and after 1-week rabeprazole, a proton pump inhibitor, administration. The maximum CO? concentration (Cmax) correlated very well with the amount of pooled gastric acid (r = 0.95), suggesting that Ca¹³CO? breath test values well reflected the fasting intragastric acidity. The ¹³CO? concentration after pentagastrin injection correlated well with pentagastrin-stimulated maximal acid output (r = 0.79 at 20 min). The reproducibility of the Ca¹³CO? breath test under pentagastrin-stimulation was good (coefficient of variation = 0.11). Rabeprazole administration markedly reduced the values of the Ca¹³CO? breath test, suggesting that it can sensitively assess the efficacy of rabeprazole. The Ca¹³CO? breath test can potentially be a useful method for non-invasive estimation for gastric acid secretion in human. PMID:24670370

Shinkai, Hirohiko; Iijima, Katsunori; Koike, Tomoyuki; Nakagawa, Kenichiro; Maejima, Ryuhei; Endo, Hiroyuki; Ara, Nobuyuki; Asano, Naoki; Imatani, Akira; Ohara, Shuichi; Shimosegawa, Tooru

2014-01-01

102

The Use of Oxalic Acid as a Chelating Agent in the Dissolution Reaction of Calcium Molybdate  

NASA Astrophysics Data System (ADS)

In this study, the dissolution behavior of calcium molybdate (CaMoO4) was investigated in oxalic acid (H2C2O4) solution. The effects of stirring speed, temperature, H2C2O4 concentration, and particle size on the dissolution reaction of CaMoO4 were determined. The dissolved quantities of molybdenum and calcium were analyzed quantitatively by ICP-OES. Fractional conversion of CaMoO4 vs time and concentration of calcium vs time diagrams were plotted. It was observed that at constant temperatures and lower H2C2O4 concentrations, the dissolution increased by increasing H2C2O4 concentration, but at higher H2C2O4 concentrations, the effect of H2C2O4 concentrations was negligible. The dissolution reaction of CaMoO4 in H2C2O4 solution was performed in two steps as series-parallel type reaction. In the first step, CaMoO4 reacted with H2C2O4 to form the water-soluble calcium aqua oxalato molybdate (Ca[MoO3(C2O4)(H2O)]) intermediate chelate product. In the second step, the intermediate chelate, Ca[MoO3(C2O4)(H2O)], reacted with the reactant, H2C2O4, to yield water-soluble hydrogen oxalato dimolybdate chelate (H2[(MoO3)2(C2O4)]) and insoluble CaC2O4H2O as final products. It was found that 500 rpm was enough to eliminate the resistance of liquid film layer that surrounds the solid particles. It was concluded that the optimum temperature was 313 K (40 °C) and the optimum concentration of H2C2O4 was 1 kmol m-3 to obtain high conversion during the dissolution of CaMoO4.

Ilhan, Sedat; Kalpakli, Ahmet Orkun; Kahruman, Cem; Yusufoglu, Ibrahim

2013-06-01

103

Dietary magnesium, not calcium, prevents vascular calcification in a mouse model for pseudoxanthoma elasticum  

Microsoft Academic Search

Pseudoxanthoma elasticum (PXE) is a heritable disorder characterized by ectopic calcification of connective tissue in skin,\\u000a Bruch’s membrane of the eye, and walls of blood vessels. PXE is caused by mutations in the ABCC6 gene, but the exact etiology is still unknown. While observations on patients suggest that high calcium intake worsens the\\u000a clinical symptoms, the patient organization PXE International

Theo G. M. F. Gorgels; Jan H. Waarsing; Anneke de Wolf; Jacoline B. ten Brink; Willem J. P. Loves; Arthur A. B. Bergen

2010-01-01

104

Formation of calcium carbonate films on chitosan substrates in the presence of polyacrylic acid  

SciTech Connect

In this investigation, chitosan membranes with different surface average degrees of deacetylation (DA) are prepared and then are employed as the support matrix to culture calcium carbonate (CaCO{sub 3}). In the presence of high concentration of polyacrylic acid (PAA), the CaCO{sub 3} films obtained on the surface of all chitosan films mainly consisted of vaterite, which suggests the presence of bulk PAA plays an overwhelming part in stabilizing the vaterite. As a comparison, the influences of active groups indicate that only in case of low concentration PAA the thin CaCO{sub 3} films grown on chitosan with 8% DA mainly consisted of vaterite owing to the strong nucleation ability of -NH{sub 2} group, whereas, for those grown on chitosan with 80% DA the CaCO{sub 3} films mainly consisted of aragonite. A more complex scenario revealed that in the case of intermediate concentration of PAA the formed polymorphs behave as mixtures of vaterite and aragonite. - Graphical abstract: Chitosan membranes with different degrees of deacetylation (DA) are employed as support to culture calcium carbonate (CaCO{sub 3}). In high concentration of polyacrylic acid (PAA), the CaCO{sub 3} films obtained consisted of vaterite. However, the CaCO{sub 3} film grown on chitosan with 8% DA mainly consisted of vaterite as opposed to aragonite for chitosan with 8% DA. The schematic presentation of the formation of calcium carbonate on chitosan films with different degrees of acetylation in the presence of PAA with low-, mid- and high concentrations.

He, Linghao; Xue, Rui [Zhengzhou University of Light Industry Henan Provincial Key Laboratory of Surface and Interface Science, Henan, Zhengzhou 450002 (China); Song, Rui, E-mail: rsong@gucas.ac.c [Zhengzhou University of Light Industry Henan Provincial Key Laboratory of Surface and Interface Science, Henan, Zhengzhou 450002 (China); College of Chemistry and Chemical Engineering, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China)

2009-05-15

105

Automated flow-injection pseudotitration of strong and weak acids, ascorbic acid and calcium, and catalytic pseudotitrations of aminopolycarboxylic acids by use of a microcomputer-controlled analyser.  

PubMed

A simple, inexpensive, fully automated spectrophotometric system for flow-injection pseudotitrations is used to perform acid-base, redox, complexometric and catalytic "titrations". Peak widths (in time units) in the range 10-100 sec can be measured with a precision of better than 0.3% in most cases. Strong and weak acids in the range 5.0 x 10(-4)-1.0 x 10(-2)M are measured by using sodium hydroxide-Bromothymol Blue "titrant". Ascorbic acid (1 x 10(-4)-1 x 10(-2)M) is "titrated" with 2,6-dichlorophenolindophenol, and calcium (5.0 x 10(-4)-5.0 x 10(-2)M) with EDTA, with calmagite as indicator in the presence of magnesium. Aminopolycarboxylic acids (5 x 10(-6)-1 x 10(-2)M) are measured by use of catalytic indication based on the manganese-catalysed periodate-diethylaniline reaction. The ascorbic acid method has been applied to analysis of pharmaceutical preparations, and the calcium method to water analysis. PMID:18963869

Koupparis, M A; Anagnostopoulou, P; Malmstadt, H V

1985-05-01

106

Hopantenic acid beta-glucoside as a new urinary metabolite of calcium hopantenate in dogs.  

PubMed

The metabolism of calcium hopantenate (HOPA) was studied in beagle dogs. After oral administration of 14C-labeled HOPA, 25.5% of the administered radioactivity was excreted in the urine within 24 hr, mostly in the form of unchanged drug. The only metabolite, accounting for 4.2% of the radioactivity in the urine, was isolated by HPLC. The metabolite was hydrolyzed by the treatment of beta-glucuronidase (Helix pomatia), acid phosphatase, or beta-glucosidase. These enzyme activities were not inhibited by treatment with D-glucaric acid 1,4-lactone or PO4(3-), but with D-gluconic acid 1,5-lactone, demonstrating that the metabolite is a glucose conjugate. The compound was identified as HOPA-glucoside, 4'-O-(beta-D-glucopyranosyl)-D-hopantenic acid, by GC/MS analyses after derivatization of the metabolite and the synthetic compound. This is the first reported instance of glucose conjugation to a non-acidic hydroxyl group in the metabolism of xenobiotics in mammals. PMID:2877836

Nakano, K; Ando, H; Sugawara, Y; Ohashi, M; Harigaya, S

1986-01-01

107

Calcium and bone disease  

PubMed Central

Calcium transport and calcium signaling are of basic importance in bone cells. Bone is the major store of calcium and a key regulatory organ for calcium homeostasis. Bone, in major part, responds to calcium-dependent signals from the parathyroids and via vitamin D metabolites, although bone retains direct response to extracellular calcium if parathyroid regulation is lost. Improved understanding of calcium transporters and calcium-regulated cellular processes has resulted from analysis of genetic defects, including several defects with low or high bone mass. Osteoblasts deposit calcium by mechanisms including phosphate and calcium transport with alkalinization to absorb acid created by mineral deposition; cartilage calcium mineralization occurs by passive diffusion and phosphate production. Calcium mobilization by osteoclasts is mediated by acid secretion. Both bone forming and bone resorbing cells use calcium signals as regulators of differentiation and activity. This has been studied in more detail in osteoclasts, where both osteoclast differentiation and motility are regulated by calcium. PMID:21674636

Blair, Harry C.; Robinson, Lisa J.; Huang, Christopher L.-H.; Sun, Li; Friedman, Peter A.; Schlesinger, Paul H.; Zaidi, Mone

2013-01-01

108

Preventive effect of a high fluoride toothpaste and arginine-carbonate toothpaste on dentinal tubules exposure followed by acid challenge: a dentine permeability evaluation  

PubMed Central

Background Considering the current high use of high fluoride toothpastes, the aim of the study was to quantify alterations in the root dentine permeability submitted to treatment with a high fluoride toothpaste and 8% arginine, calcium carbonate, sodium monofluorophosphate toothpaste as a preventive treatment for dentinal tubules exposure followed by acid challenge. Methods Thirty-third molars were sectioned below the cementoenamel. The root segments were connected to a hydraulic pressure apparatus to measure dentine permeability after the following sequential steps (n = 10 per group): I) Baseline; II) treatment with phosphoric acid for 30 s (maximum permeability); III) Toothbrushing (1 min) according to the experimental groups (G1- control; G2- 5000 ppm fluoride toothpaste; G3- 8% arginine-calcium carbonate toothpaste); IV) acid challenge for 5 min (orange juice). The data were converted into percentage, considering stage II as 100%. Results The results have shown a statistically significant decreasing on dentine permeability after treatment with toothpaste (Friedman test and Dunn’s post hoc test). Comparison among groups demonstrated a high increasing on dentine permeability when acid challenge was performed after toothbrushing with distilled water (control group) (Kruskal-Wallis and Dunn’s post hoc test). Conclusion The toothpaste treatment may provide sufficient resistance on dentine surface, preventing dentinal tubules exposure after acid challenge. PMID:24958423

2014-01-01

109

Purification and characterisation of a glutamic acid-containing peptide with calcium-binding capacity from whey protein hydrolysate.  

PubMed

The bioavailability of dietary ionised calcium is affected by intestinal basic environment. Calcium-binding peptides can form complexes with calcium to improve its absorption and bioavailability. The aim of this study was focused on isolation and characterisation of a calcium-binding peptide from whey protein hydrolysates. Whey protein was hydrolysed using Flavourzyme and Protamex with substrate to enzyme ratio of 25 : 1 (w/w) at 49 °C for 7 h. The calcium-binding peptide was isolated by DEAE anion-exchange chromatography, Sephadex G-25 gel filtration and reversed phase high-performance liquid chromatography (RP-HPLC). A purified peptide of molecular mass 204 Da with strong calcium binding ability was identified on chromatography/electrospray ionisation (LC/ESI) tandem mass spectrum to be Glu-Gly (EG) after analysis and alignment in database. The calcium binding capacity of EG reached 67·81 ?g/mg, and the amount increased by 95% compared with whey protein hydrolysate complex. The UV and infrared spectrometer analysis demonstrated that the principal sites of calcium-binding corresponded to the carboxyl groups and carbonyl groups of glutamic acid. In addition, the amino group and peptide amino are also the related groups in the interaction between EG and calcium ion. Meanwhile, the sequestered calcium percentage experiment has proved that EG-Ca is significantly more stable than CaCl2 in human gastrointestinal tract in vitro. The findings suggest that the purified dipeptide has the potential to be used as ion-binding ingredient in dietary supplements. PMID:25592629

Huang, Shun-Li; Zhao, Li-Na; Cai, Xixi; Wang, Shao-Yun; Huang, Yi-Fan; Hong, Jing; Rao, Ping-Fan

2015-02-01

110

Fatty acid profile and physical properties of milk fat from cows fed calcium salts of fatty acids with varying unsaturation.  

PubMed

Holstein cows (n = 24) averaging 42 d in milk were used in a randomized complete block design during a 4-wk trial. A control total mixed ration (TMR) was compared with TMR supplemented with Ca salts of fatty acids from canola oil, soybean oil, or linseed oil. The three vegetable oils were progressively more unsaturated; the dominant fatty acids were, respectively, cis-delta-9-C18:1, C18:2, and C18:3. Apparent total tract digestibility of dry matter, crude protein, ether extract, and neutral detergent fiber was higher for rations containing Ca salts than for the control ration. Milk yield increased linearly as the unsaturation of the dominant fatty acid in the Ca salts increased. Milk fat percentage was reduced when Ca salts were added to the rations. The addition of Ca salts to the ration decreased the proportions of saturated fatty acids that contained C6 to C16 and increased the proportions of C18:0, cis-delta-C18:1, and trans-delta-11-C18:1 in milk fat. Proportions of C18:2 and C18:3 increased linearly, and cis-delta-9-C18:1 decreased linearly, as the unsaturation of the dominant fatty acid in the Ca salts increased. The proportion of fat that was liquid at 5 degrees C was higher for butter from cows fed diets containing Ca salts, but the proportion of liquid fat at 20 degrees C was not affected. Calcium salts of unsaturated fatty acids added to the diets of dairy cows improved the thermal properties of milk fat. PMID:9532502

Chouinard, P Y; Girard, V; Brisson, G J

1998-02-01

111

The crystallinity of calcium phosphate powders influenced by the conditions of neutralized procedure with citric acid additions  

SciTech Connect

Calcium phosphate powders with nano-sized crystallinity were synthesized by neutralization using calcium hydroxide and orthophosphoric acid with the assistance of citric acid. The influence of processing parameters, such as free or additive citric acid, synthetic temperature and ripening time, on the crystallinity of hydroxyapatite were investigated. The results of X-ray diffraction and microstructure observations showed that the crystallinity and morphology of nano-sized hydroxyapatite particles were influenced by the presence or absence of citric acid. It was found that the crystallinities and crystallite sizes of hydroxyapatite powders prepared with the additive citric acid increased with increasing synthetic temperature and ripening time. Especially, the crystallinities of (h k 0) planes were raised and more homogeneously grown particles were obtained with increasing synthetic temperature.

Li Chengfeng [School of Materials Science and Engineering, Shandong University of Technology, No. 12 Zhangzhou Road, 255049 Zibo, Shandong (China)], E-mail: cfli@sdut.edu.cn

2009-05-06

112

Protection of human umbilical vein endothelial cells by glycine and structurally similar amino acids against calcium and hydrogen peroxide-induced lethal cell injury.  

PubMed Central

Cultured human umbilical vein endothelial cells treated with either the calcium ionophore, ionomycin, or ionomycin plus cyanide-m-chlorophenylhydrazone had immediate severe depletion of adenosine triphosphate, (ATP) and increases of cytosolic free calcium (Caf) and then sustained lethal cell injury as manifested by release of lactate dehydrogenase and failure to exclude vital dyes within 15 minutes. Inclusion of glycine in the experimental medium prevented the enzyme leakage for at least 60 minutes without altering the ATP depletion or increases of Caf. The physiologic glycine concentration of 0.25 mmol/l gave 50% protection, and protection was complete at 1 mmol/l. Several other small neutral amino acids, L- and D-alanine, beta-alanine, 1-aminocyclopropane-1-carboxylate, alpha-aminoisobutyrate, and L-serine, had effects similar to glycine, but other amino acids and metabolic substrates did not. The endothelial cells were relatively resistant to damage from hydrogen peroxide, but sensitivity could be increased by preloading with Fe2+. In both non-loaded and Fe(2+)-loaded cells, hydrogen-peroxide-induced lactate dehydrogenase (LDH) release developing over 180 minutes was prevented by glycine in a fashion analogous to that seen with ionomycin damage. Mn2+ also partially protected against hydrogen peroxide injury but was not required for glycine's effects. These data demonstrate that striking modulatory effects of glycine and structurally similar amino acids that have previously been characterized in most detail using kidney tubule cells are strongly expressed in human umbilical vein endothelial cells and are involved in their response to Ca2+ and oxidant-mediated damage. These amino acid effects must be considered in the design of in vitro studies of endothelial cell injury and may contribute to endothelial cell pathophysiology in vivo. Images Figure 3 Figure 4 PMID:1739136

Weinberg, J. M.; Varani, J.; Johnson, K. J.; Roeser, N. F.; Dame, M. K.; Davis, J. A.; Venkatachalam, M. A.

1992-01-01

113

The changes of stratum corneum interstices and calcium distribution of follicular epithelium of experimentally induced comedones (EIC) by oleic acid.  

PubMed

Abnormal follicular keratinization is important for comedo formation in acne, but the precise mechanism is not known. A recent report about acne vulgaris suggested that an impaired water barrier function may be responsible for comedo formation, since the barrier dysfunction is accompanied by hyperkeratosis of the follicular epithelium. Furthermore, the integrity of the water barrier is crucial for the maintenance of the epidermal calcium gradient. Yet stratum corneum intercellular lipid structures, a major factor of the skin barrier function, and calcium distribution in the follicular epithelium of comedones, were not reported. To see SC intercellular lipid and calcium distribution of the follicular epithelium of comedo by electron microscopy, we applied oleic acid on the inner surface of the ear of New Zealand white rabbits to induce comedones, and then we obtained specimens and performed osmium and ruthenium tetroxide postfixation and calcium ion-capture cytochemical procedure. We found incomplete lipid bilayer structures, prominent dilatation of lacunar domains and the loss of follicular epidermal calcium gradient in experimentally induced comedones. From our results, we suggest that the permeability barrier disruption in oleic-acid-applied follicular epithelium can be induced by the changes of SC intercellular membrane structures and lacunar dilatation, and the calcium gradient is lost, so follicular epithelial proliferation and hyperkeratosis can be induced and then comedo formation occurs. PMID:9067704

Choi, E H; Ahn, S K; Lee, S H

1997-02-01

114

Blockage of mitochondrial calcium uniporter prevents iron accumulation in a model of experimental subarachnoid hemorrhage.  

PubMed

Previous studies have shown that iron accumulation is involved in the pathogenesis of brain injury following subarachnoid hemorrhage (SAH) and chelation of iron reduced mortality and oxidative DNA damage. We previously reported that blockage of mitochondrial calcium uniporter (MCU) provided benefit in the early brain injury after experimental SAH. This study was undertaken to identify whether blockage of MCU could ameliorate iron accumulation-associated brain injury following SAH. Therefore, we used two reagents ruthenium red (RR) and spermine (Sper) to inhibit MCU. Sprague-Dawley (SD) rats were randomly divided into four groups including sham, SAH, SAH+RR, and SAH+Sper. Biochemical analysis and histological assays were performed. The results confirmed the iron accumulation in temporal lobe after SAH. Interestingly, blockage of MCU dramatically reduced the iron accumulation in this area. The mechanism was revealed that inhibition of MCU reversed the down-regulation of iron regulatory protein (IRP) 1/2 and increase of ferritin. Iron-sulfur cluster dependent-aconitase activity was partially conserved when MCU was blocked. In consistence with this and previous report, ROS levels were notably reduced and ATP supply was rescued; levels of cleaved caspase-3 dropped; and integrity of neurons in temporal lobe was protected. Taken together, our results indicated that blockage of MCU could alleviate iron accumulation and the associated injury following SAH. These findings suggest that the alteration of calcium and iron homeostasis be coupled and MCU be considered to be a therapeutic target for patients suffering from SAH. PMID:25529443

Yan, Huiying; Hao, Shuangying; Sun, Xiaoyan; Zhang, Dingding; Gao, Xin; Yu, Zhuang; Li, Kuanyu; Hang, Chun-Hua

2015-01-24

115

A comparison of calcium to zoledronic acid for improvement of cortical bone in an animal model of CKD.  

PubMed

Patients with chronic kidney disease (CKD) have increased risk of fractures, yet the optimal treatment is unknown. In secondary analyses of large randomized trials, bisphosphonates have been shown to improve bone mineral density and reduce fractures. However, bisphosphonates are currently not recommended in patients with advanced kidney disease due to concern about oversuppressing bone remodeling, which may increase the risk of developing arterial calcification. In the present study we used a naturally occurring rat model of CKD with secondary hyperparathyroidism, the Cy/+ rat, and compared the efficacy of treatment with zoledronic acid, calcium given in water to simulate a phosphate binder, and the combination of calcium and zoledronic acid. Animals were treated beginning at 25 weeks of age (approximately 30% of normal renal function) and followed for 10 weeks. The results demonstrate that both zoledronic acid and calcium improved bone volume by micro-computed tomography (µCT) and both equally suppressed the mineral apposition rate, bone formation rate, and mineralizing surface of trabecular bone. In contrast, only calcium treatment with or without zoledronic acid improved cortical porosity and cortical biomechanical properties (ultimate load and stiffness) and lowered parathyroid hormone (PTH). However, only calcium treatment led to the adverse effects of increased arterial calcification and fibroblast growth factor 23 (FGF23). These results suggest zoledronic acid may improve trabecular bone volume in CKD in the presence of secondary hyperparathyroidism, but does not benefit extraskeletal calcification or cortical biomechanical properties. Calcium effectively reduces PTH and benefits both cortical and trabecular bone yet increases the degree of extra skeletal calcification. © 2014 American Society for Bone and Mineral Research. PMID:24038306

Moe, Sharon M; Chen, Neal X; Newman, Christopher L; Gattone, Vincent H; Organ, Jason M; Chen, Xianming; Allen, Matthew R

2014-04-01

116

[The vitamin D allowance of premature infants and their phosphorus-calcium metabolic status with different types of feeding and rickets prevention].  

PubMed

The content of 25-hydroxycholecalciferol, calcium and phosphorus in blood serum was measured in 80 premature infants aged 12 to 120 days depending on the type of feeding and rickets prevention. Administration of vitamin D in a dose of 400 IU and increase of calcium consumption up to 110-120 mg and of phosphorus to 45-57 mg per kg body weight at the expense of calcinated cottage introduction into the diet provide for the optimal levels of 25-hydroxycholecalciferol and calcium in the blood of these children. Administration of calcium and phosphorus to children receiving breast feeding in doses of 80-90 and 33-37 mg/kg, respectively, is not sufficient for the maintenance of calcium homeostasis and endogenous supply with vitamin D even if the latter is given prophylactically. When children are fed with the mixture Maliutka, the maximal permissible dose of vitamin D may amount to 800 IU a day. Administration of vitamin D in a dose of 3750 IU is fraught with a danger of hypervitaminosis D in the presence of high alimentary supply with calcium and phosphorus and does not make calcium homeostasis return to normal in the presence of low supply with these mineral substances. PMID:2378101

Shakirova, E M; Pereverzeva, O G

1990-01-01

117

Inhibition of Aldose Reductase Prevents Endotoxin-Induced Inflammation by Regulating Arachidonic Acid Pathway in Murine Macrophages  

PubMed Central

Bacterial endotoxin, lipopolysaccharide (LPS) is known to induce release of arachidonic acid (AA) and its metabolic products which play important role in inflammatory process. We have shown earlier that LPS-induced signals in macrophages are mediated by aldose reductase (AR). Here we have investigated the role of AR in LPS-induced release of AA metabolites and their modulation using a potent pharmacological inhibitor fidarestat and AR-siRNA ablation in RAW 264.7 macrophages, and AR-knockout mice peritoneal macrophages and heart tissue. Inhibition or genetic ablation of AR prevented the LPS-induced synthesis and release of AA metabolites such as PGE2, TXB, PGI2 and LTBs in macrophages. LPS-induced activation of cPLA2 was also prevented by AR inhibition. Similarly, AR inhibition also prevented the calcium ionophore A23187 –induced cPLA2 and LTB4 in macrophages. Further, AR inhibition with fidarestat prevented the expression of AA metabolizing enzymes such as COX-2 and LOX-5 in RAW 264.7 cells and AR-knockout mice derived peritoneal macrophages. LPS-induced expression of AA metabolizing enzymes and their catalyzed metabolic products were significantly lower in peritoneal macrophages and heart tissue from AR-knockout mice. LPS-induced activation of redox-sensitive signaling intermediates such as MAPKs, transcription factor NF-kB as well as Egr-1, a transcription regulator of mPGES-1, which in collaboration with COX-2 leads to the production of PGE2, were also significantly prevented by AR inhibition. Taken together, our results indicate that AR mediates LPS-induced inflammation by regulating AA metabolic pathway and thus provide novel role of AR inhibition in preventing inflammatory complications such as sepsis. PMID:21856412

Shoeb, Mohammad; Yadav, Umesh CS; Srivastava, Satish K; Ramana, Kota V

2011-01-01

118

Grafting process of ethyltrimethoxysilane and polyphosphoric acid on calcium carbonate surface  

NASA Astrophysics Data System (ADS)

In order to facilitate its incorporation into a polymer matrix (mostly hydrophobic), calcium carbonate (CaCO3), which is strongly hydrophilic, has to be chemically treated to avoid the formation of aggregates and to improve the compatibility with the polymer. The objective of this study is to analyze, by using contact angle measurements and X-ray photoelectron spectroscopy (XPS), the CaCO3 surface after a chemical surface treatment with ethyltrimethoxysilane (ETMO) and polyphosphoric acid (PPA) in an organic solvent, in order to verify if these molecules are able to interact with the CaCO3 surface, and to propose some hypothesis about the surface grafting mechanism. After several solvent washings were performed to remove all species in excess, contact angle results have pointed out the presence of an organic layer after the chemical treatment of CaCO3 with ETMO and PPA. Based on XPS results, we propose a grafting mechanism of silane and phosphoric acid molecules. Ethyltrimethoxysilane induce an hydrolysis process of the CaCO3 surface which leads to a condensation phenomenon. This Sisbnd OH network is adsorbed through hydrogen interactions with some hydroxyl groups. In the case of phosphoric acid, the molecules are adsorbed on carbon atoms through Psbnd Osbnd C bonds formation. This original grafting points out the major role of the solvent nature with CaCO3 surface reactivity.

Kiehl, J.; Ben-Azzouz, C.; Dentel, D.; Derivaz, M.; Bischoff, J. L.; Delaite, C.; Bistac, S.

2013-01-01

119

Cyclopiazonic acid disturbs the regulation of cytosolic calcium when repetitive action potentials are evoked in Dionaea traps  

Microsoft Academic Search

Evoking of action potentials (APs) in the trap of Dionaea muscipula Ellis at intervals shorter than 20 s caused a gradual decrease in the amplitude of the APs. At longer intervals the amplitude was constant. The calcium ionophore A23187 (1 µM) caused a considerable decrease of AP amplitude. Pretreatment of a segment of the Dionaea trap with cyclopiazonic acid (CPA),

Kazimierz Trebacz; Marion B. Busch; Zygmunt Hejnowicz; Andreas Sievers

1996-01-01

120

Analysis of carbon functional groups in mobile humic acid and recalcitrant calcium humate extracted from eight US soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

Solid state 13C nuclear magnetic resonance (NMR) spectroscopy is a common tool to study the structure of soil humic fractions; however, knowledge regarding carbon structural relationships in humic fractions is limited. In this study, mobile humic acid (MHA) and recalcitrant calcium humate (CaHA) fr...

121

Zoledronic Acid Prevents Bone Loss During Estrogen-Suppression Treatment of Breast Cancer  

Cancer.gov

Zoledronic acid can prevent treatment-induced bone loss in premenopausal women undergoing total estrogen suppression after surgery for hormone-responsive breast cancer, according to an article published online Jan. 3, 2007, in the Journal of Clinical Oncology.

122

?-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid receptor activation protects against phencyclidine-induced caspase-3 activity by activating voltage-gated calcium channels.  

PubMed

Phencyclidine (PCP) is a noncompetitive, open channel blocker of the N-methyl-D-aspartate (NMDA) receptor-ion channel complex. When administered to immature animals, it is known to cause apoptotic neurodegeneration in several regions, and this is followed by olanzapine-sensitive, schizophrenia-like behaviors in late adolescence and adulthood. Clarification of its mechanism of action could yield data that would help to inform the treatment of schizophrenia. In our initial experiments, we found that ?-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) inhibited PCP-induced apoptosis in organotypic neonatal rat brain slices in a concentration-dependent and 6-cyano-7-nitroquinoxaline-2,3-dione-sensitive manner. Calcium signaling pathways are widely implicated in apoptosis, and PCP prevents calcium influx through NMDA receptor channels. We therefore hypothesized that AMPA could protect against this effect by activation of voltage-dependent calcium channels (VDCCs). In support of this hypothesis, pretreatment with the calcium channel blocker cadmium chloride eliminated AMPA-mediated protection against PCP. Furthermore, the L-type VDCC inhibitor nifedipine (10 µM) fully abrogated the effects of AMPA, suggesting that L-type VDCCs are required for AMPA-mediated protection against PCP-induced neurotoxicity. Whereas the P/Q-type inhibitor ?-agatoxin TK (200 nM) reduced AMPA protection by 51.7%, the N-type VDCC inhibitor ?-conotoxin (2 µM) had no effect. Decreased AMPA-mediated protection following cotreatment with K252a, a TrkB inhibitor, suggests that brain-derived neurotrophic factor signaling plays an important role. By analogy, these results suggest that activation of L-type, and to a lesser extent P/Q-type, VDCCs might be advantageous in treating conditions associated with diminished NMDAergic activity during early development. PMID:24995437

Timpe, Jennifer M; Wang, Cheng Z; Kim, Jisoo; Johnson, Kenneth M

2014-12-01

123

Effect of Dose of Calcium Salts of Conjugated Linoleic Acid (CLA) on Percentage and Fatty Acid Content of Milk Fat in Midlactation Holstein Cows1  

Microsoft Academic Search

Increasing conjugated linoleic acid (CLA) content of milk fat from lactating dairy cattle has become a re- search interest due to the possible health benefits af- forded humans consuming CLA. Dietary supplementa- tion of CLA to lactating dairy cows is one potential method by which CLA content of milk and dairy prod- ucts may be enhanced. Feeding CLA in calcium

J. G. Giesy; M. A. McGuire; B. Shafii; T. W. Hanson

2002-01-01

124

MINE WASTE TECHNOLOGY PROGRAM PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT HIGHWALLS  

EPA Science Inventory

This document summarizes the results of Mine Waste Technology Program Activity III, Project 26, Prevention of Acid Mine Drainage Generation from Open-Pit Highwalls. The intent of this project was to obtain performance data on the ability of four technologies to prevent the gener...

125

Modulation of the mitochondrial large-conductance calcium-regulated potassium channel by polyunsaturated fatty acids.  

PubMed

Polyunsaturated fatty acids (PUFAs) and their metabolites can modulate several biochemical processes in the cell and thus prevent various diseases. PUFAs have a number of cellular targets, including membrane proteins. They can interact with plasma membrane and intracellular potassium channels. The goal of this work was to verify the interaction between PUFAs and the most common and intensively studied mitochondrial large conductance Ca(2+)-regulated potassium channel (mitoBKCa). For this purpose human astrocytoma U87 MG cell lines were investigated using a patch-clamp technique. We analyzed the effects of arachidonic acid (AA); eicosatetraynoic acid (ETYA), which is a non-metabolizable analog of AA; docosahexaenoic acid (DHA); and eicosapentaenoic acid (EPA). The open probability (Po) of the channel did not change significantly after application of 10?M ETYA. Po increased, however, after adding 10?M AA. The application of 30?M DHA or 10?M EPA also increased the Po of the channel. Additionally, the number of open channels in the patch increased in the presence of 30?M EPA. Collectively, our results indicate that PUFAs regulate the BKCa channel from the inner mitochondrial membrane. PMID:25046142

Olszewska, Anna; Bednarczyk, Piotr; Siemen, Detlef; Szewczyk, Adam

2014-10-01

126

Calcium involved in the poly(?-glutamic acid)-mediated promotion of Chinese cabbage nitrogen metabolism.  

PubMed

Plant growth can reportedly be promoted by poly(?-glutamic acid) (?-PGA). However, the underlying mechanism is unknown. To reveal the mechanism of ?-PGA, we designed an experiment that investigated the effect of ?-PGA on the nitrogen metabolism of Chinese cabbage hydroponic cultured at different calcium (Ca) levels and varied exogenous Ca(2+) inhibitors. The results showed that nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase, and glutamate dehydrogenase activities in leaves and roots were obviously enhanced by ?-PGA at the normal Ca(2+) level (4.0 mM). Meanwhile, ?-PGA increased the content of total nitrogen, soluble protein, and soluble amino acids in leaves. However, the promotional effect of ?-PGA on fresh weight weakened when Ca(2+) was inadequate. Moreover, ?-PGA not only induced the influx of extracellular Ca(2+) and Ca(2+) in organelles into cytoplasm, but also increased the Ca(2+)-ATPase level to modify Ca(2+) homeostasis in plant cells. In addition, exogenous Ca(2+) inhibitors significantly suppressed the ?-PGA-mediated promotion of cytoplasmic free Ca(2+) level, calmodulin (CaM) content, GS and glutamate dehydrogenase activities. In summary, ?-PGA accelerated the nitrogen metabolism of plants through the Ca(2+)/CaM signaling pathway, thereby improving the growth of the plant. PMID:24762787

Xu, Zongqi; Lei, Peng; Feng, Xiaohai; Xu, Xianju; Liang, Jinfeng; Chi, Bo; Xu, Hong

2014-07-01

127

The retention of calcium, barium, and strontium ions by a mollisol humic acid: Spectroscopic investigation  

NASA Astrophysics Data System (ADS)

Humic substances have a major role in controlling the mobility and bioavailability of metallic ions in soils and natural waters. The alkaline earth metals, calcium, barium, and strontium, are broadly abundant in the crust of the earth, and Ca2+ ions are known to be important in the formation of structural aggregates in soils. Yet, direct spectroscopic evidence of how Ca, Ba, and Sr ions interact with soil organic matter, is minimal. To develop a deeper understanding of the interaction of the alkaline earth cations in soil, we studied the complexation behavior of strontium, barium and calcium by humic acid (HA) using solid-state 13C CP-MAS NMR, FTIR and extended x-ray absorption fine structure (EXAFS) spectroscopy. A HA sample was extracted from an agricultural mollisol (pH 6, 32.5% clay content, 3.7% organic carbon) located in southwestern Minnesota, USA, by the standard NaOH method. The HA sample was treated with chloride salts of Ca, Sr or Ba, then freeze-dried prior to spectroscopic measurements. The FTIR spectra, obtained using pressed KBr disks, and the 13C NMR spectra revealed spectral differences, stemming mainly from deprotonation reactions of the carboxylic and phenolic groups of the HA. The association of Ca, Ba, and Sr ions with the HA caused a marked FTIR shift of the carboxylate band, with the Ba shift being the most pronounced (HA 1604.7; HA-Ca 1595.1; HA-Sr 1597; HA-Ba 1579.6), which seems to imply that Ba is the strongest bound element. An NMR shift of the carbonyl peak at 171.8 ppm was also observed to 174.5 for Ca, 173.7 for Sr, and 174.4 for Ba confirming that these cations are behaving differently towards soil HA. The EXAFS spectra indicated back-scattering from oxygen atoms, in the first shell, for Ca, Sr, and Ba with varied coordination number. Our data prove that (1) the carboxylates and phenolates are the prevailing functional groups involved in the interactions between the extracted HA and alkali metal cations, (2) barium forms the strongest complex compared to strontium and calcium.

Oufqir, Sofia; Bloom, Paul R.; Torner, Brandy M.

2014-05-01

128

Hydrogen production from steam reforming of acetic acid over Cu-Zn supported calcium aluminate.  

PubMed

Hydrogen can be produced by catalytic steam reforming (CSR) of biomass-derived oil. Typically bio oil contains 12-14% acetic acid; therefore, this acid was chosen as model compound for reforming of biooil with the help of a Cu-Zn/Ca-Al catalyst for high yield of H(2) with low CH(4) and CO content. Calcium aluminate support was prepared by solid-solid reaction at 1350°C. X-ray diffraction indicates 12CaO·7Al(2)O(3) as major, CaA(l4)O(7) and Ca(5)A(l6)O(14) as minor phases. Cu and Zn were loaded onto the support by wet-impregnation at 10 and 1wt.%, respectively. The catalysts were characterized by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy TEM and the surface area for both support and Cu-Zn were 10.5 and 5.8m(2)/g, respectively. CSR was carried out in a tubular fixed bed reactor (I.D.=19mm) at temperatures between 600 and 800°C with 3-g loadings and (H(2)O/acetic acid) wt. ratio of 9:1. Significantly high (80%) yield of hydrogen was obtained over Cu-Zn/Ca-Al catalyst, as incorporation of Zn enhanced the H(2) yield by reducing deactivation of the catalyst. The coke formation on the support (Ca-12/Al-7) surface was negligible due to the presence of excess oxygen in the 12CaO·7Al(2)O(3) phase. PMID:22944490

Mohanty, Pravakar; Patel, Madhumita; Pant, Kamal K

2012-11-01

129

Resveratrol inhibits the intracellular calcium increase and angiotensin/endothelin system activation induced by soluble uric acid in mesangial cells.  

PubMed

Resveratrol (Resv) is natural polyphenol found in grapes. This study evaluated the protective effect of Resv against the effects of uric acid (UA) in immortalized human mesangial cells (ihMCs). ihMCs were preincubated with Resv (12.5 µM) for 1 h and treated with UA (10 mg/dL) for 6 or 12 h. The intracellular calcium concentration [Ca2+]i was quantified by fluorescence using flow cytometry. Angiotensinogen (AGT) and pre-pro endothelin-1 (ppET-1) mRNA were assayed by quantitative real-time RT-PCR. Angiotensin II (AII) and endothelin-1 (ET-1) were assayed by ELISA. UA significantly increased [Ca2+]i. Pre-incubation with Resv significantly reduced the change in [Ca2+]i induced by UA. Incubation with UA for 6 or 12 h also increased AGT mRNA expression and AII protein synthesis. Resv blunted these increases in AGT mRNA expression and AII protein. Incubation with UA in the ihMCs increased ppET-1 expression and ET-1 protein synthesis at 6 and 12 h. When ihMCs were pre-incubated with Resv, UA had a significantly diminished effect on ppET-1 mRNA expression and ET-1 protein synthesis at 6 and 12 h, respectively. Our results suggested that UA triggers reactions including AII and ET-1 production in mesangial cells. The renin-angiotensin system may contribute to the pathogenesis of renal function and chronic kidney disease. Resv can minimize the impact of UA on AII, ET-1 and the increase of [Ca2+]i in mesangial cells, suggesting that, at least in part, Resv can prevent the effects of soluble UA in mesangial cells. PMID:25493383

Albertoni, G; Schor, N

2015-01-01

130

Resveratrol inhibits the intracellular calcium increase and angiotensin/endothelin system activation induced by soluble uric acid in mesangial cells  

PubMed Central

Resveratrol (Resv) is natural polyphenol found in grapes. This study evaluated the protective effect of Resv against the effects of uric acid (UA) in immortalized human mesangial cells (ihMCs). ihMCs were preincubated with Resv (12.5 µM) for 1 h and treated with UA (10 mg/dL) for 6 or 12 h. The intracellular calcium concentration [Ca2+]i was quantified by fluorescence using flow cytometry. Angiotensinogen (AGT) and pre-pro endothelin-1 (ppET-1) mRNA were assayed by quantitative real-time RT-PCR. Angiotensin II (AII) and endothelin-1 (ET-1) were assayed by ELISA. UA significantly increased [Ca2+]i. Pre-incubation with Resv significantly reduced the change in [Ca2+]i induced by UA. Incubation with UA for 6 or 12 h also increased AGT mRNA expression and AII protein synthesis. Resv blunted these increases in AGT mRNA expression and AII protein. Incubation with UA in the ihMCs increased ppET-1 expression and ET-1 protein synthesis at 6 and 12 h. When ihMCs were pre-incubated with Resv, UA had a significantly diminished effect on ppET-1 mRNA expression and ET-1 protein synthesis at 6 and 12 h, respectively. Our results suggested that UA triggers reactions including AII and ET-1 production in mesangial cells. The renin-angiotensin system may contribute to the pathogenesis of renal function and chronic kidney disease. Resv can minimize the impact of UA on AII, ET-1 and the increase of [Ca2+]i in mesangial cells, suggesting that, at least in part, Resv can prevent the effects of soluble UA in mesangial cells. PMID:25493383

Albertoni, G.; Schor, N.

2014-01-01

131

Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) May Be an Alternative Preventive Therapy in Children with Cerebral Palsy.  

PubMed

Purpose: To evaluate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the buffering capacity of saliva and plaque pH in individuals with cerebral palsy (CP). Materials and Methods: A total of 15 3- to 8-year-old subjects with CP living in a governmental institution were included in this study. Dental plaque pH and the buffering capacity of saliva were measured at the first visit (baseline) and accepted as control values. CPP-ACP complex (GC Tooth Mousse) was applied to the children twice a day. Measurements were repeated after the 1st, 2nd, 3rd, 4th, 6th and 8th weeks. Results: Plaque indicator data show decreased acidogenicity in the 8-week period. Although there were no significant differences between the baseline and the 1st, 2nd and 3rd weeks' pH scores, a statistically significant difference was observed between the initial and 4th, 6th and 8th weeks' plaque pH scores. Saliva buffer scores were found to statistically significant increase between baseline and the 3rd, 4th, 6th and 8th weeks. Conclusion: Daily application of 10% w/v CPP-ACP paste is effectively changes saliva buffering capacity and plaque pH, thus promoting caries prevention in the primary and mixed dentition of CP children. PMID:25431804

Ozdas, Didem Oner; Tuna, Elif Bahar; Yilmaz, Esra Yamac; Aytepe, Zeynep

2014-11-27

132

Antimicrobial activity of gallic acid against thermophilic Campylobacter is strain specific and associated with a loss of calcium ions.  

PubMed

Gallic acid has been suggested as a potential antimicrobial for the control of Campylobacter but its effectiveness is poorly studied. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of gallic acid against Campylobacter jejuni (n = 8) and Campylobacter coli (n = 4) strains was determined. Gallic acid inhibited the growth of five C. jejuni strains and three C. coli strains (MIC: 15.63-250 ?g mL(-1)). Gallic acid was only bactericidal to two C. coli strains (MBC: 125 and 62.5 ?g mL(-1)). The mechanism of the bactericidal effect against these two strains (and selected non-susceptible controls) was investigated by determining decimal reduction times and by monitoring the loss of cellular content and calcium ions, and changes in cell morphology. Gallic acid did not result in a loss of cellular content or morphological changes in the susceptible strains as compared to the controls. Gallic acid resulted in a loss of calcium ions (0.58-1.53 ?g mL(-1) and 0.54-1.17 ?g mL(-1), respectively, over a 180 min period) from the susceptible strains but not the controls. Gallic acid is unlikely to be an effective antimicrobial against Campylobacter in a practical sense unless further interventions to ensure an effective bactericidal mode of action against all strains are developed. PMID:25475290

Sarjit, Amreeta; Wang, Yi; Dykes, Gary A

2015-04-01

133

Enhancement of root hydraulic conductivity by methyl jasmonate and the role of calcium and abscisic acid in this process.  

PubMed

The role of jasmonic acid in the induction of stomatal closure is well known. However, its role in regulating root hydraulic conductivity (L) has not yet been explored. The objectives of the present research were to evaluate how JA regulates L and how calcium and abscisic acid (ABA) could be involved in such regulation. We found that exogenous methyl jasmonate (MeJA) increased L of Phaseolus vulgaris, Solanum lycopersicum and Arabidopsis thaliana roots. Tomato plants defective in JA biosynthesis had lower values of L than wild-type plants, and that L was restored by addition of MeJA. The increase of L by MeJA was accompanied by an increase of the phosphorylation state of the aquaporin PIP2. We observed that MeJA addition increased the concentration of cytosolic calcium and that calcium channel blockers inhibited the rise of L caused by MeJA. Treatment with fluoridone, an inhibitor of ABA biosynthesis, partially inhibited the increase of L caused by MeJA, and tomato plants defective in ABA biosynthesis increased their L after application of MeJA. It is concluded that JA enhances L and that this enhancement is linked to calcium and ABA dependent and independent signalling pathways. PMID:24131347

Sánchez-Romera, Beatriz; Ruiz-Lozano, Juan Manuel; Li, Guowei; Luu, Doan-Trung; Martínez-Ballesta, Maria del Carmen; Carvajal, Micaela; Zamarreño, Angel María; García-Mina, Jose María; Maurel, Christophe; Aroca, Ricardo

2014-04-01

134

Oleuropein, chief constituent of olive leaf extract, prevents the development of morphine antinociceptive tolerance through inhibition of morphine-induced L-type calcium channel overexpression.  

PubMed

It has been shown that blockade of L-type calcium channels could abolish the development of opioid-induced antinociceptive tolerance. Here, the antitolerant effects of olive leaf extract (OLE) and its main component, oleuropein, which have a calcium channel blocker property were determined. Adult male Wistar rats were injected with morphine (20?mg/kg, i.p.) for 8?days to induce antinociceptive tolerance. Then OLE (50-200?mg/kg i.g.) and oleuropein (1-10?mg/kg?i.p.) were injected concomitantly with morphine. The tail-flick test was used to assess the nociceptive threshold. The dorsal half of the lumbar spinal cord was assayed for the expression of L-type calcium channel using semiquantitative RT-PCR. The results showed that OLE (200?mg/kg) completely prevented morphine tolerance development. In addition, oleuropein in dose of 10?mg/kg, but not in 5?mg/kg, prevented the development of morphine antinociceptive tolerance. In addition, a significant increase in the mRNA levels of calcium channel (43.9%) was observed in the lumbar spinal cord of tolerant animals, which was reversed by effective of dose OLE. In conclusion, the results indicate that olive leaf extract has a potential antitolerant property against the chronic usage of morphine and that its main component, oleuropein, is responsible for such effect. PMID:22422486

Zare, Leila; Esmaeili-Mahani, Saeed; Abbasnejad, Mehdi; Rasoulian, Bahram; Sheibani, Vahid; Sahraei, Hedayat; Kaeidi, Ayat

2012-11-01

135

Calcium balance and acid-base status of women as affected by increased protein intake and by sodium bicarbonate ingestion13  

Microsoft Academic Search

Six women, aged 38 to 62 yr. participated in a 40-day metabolic study to investigate the effect of level of protein intake and of sodium bicarbonate ingestion on urinary calcium, net calcium balance, net renal acid excretion, and arterialized venous blood pH and bicarbonate ion concentration. The diet contained 44 g protein during the first 16 days and 102 g

Josephine Lutz

136

Novel 5-substituted benzyloxy-2-arylbenzofuran-3-carboxylic acids as calcium activated chloride channel inhibitors  

PubMed Central

Transmembrane protein 16A (TMEM16A) channels are recently discovered membrane proteins that functions as a calcium activated chloride channel (CaCC). CaCCs are major regulators of various physiological processes, such as sensory transduction, epithelial secretion, smooth muscle contraction and oocyte fertilization. Thirty novel 5-substituted benzyloxy-2-arylbenzofuran-3-carboxylic acids (B01–B30) were synthesized and evaluated for their TMEM16A inhibitory activity by using short circuit current measurements in Fischer rat thyroid (FRT) cells expressing human TMEM16A. IC50 values were calculated using YFP fluorescence plate reader assay. Final compounds, having free carboxylic group displayed significant inhibition. Eight of the novel compounds B02, B13, B21, B23, B25, B27, B28, B29 exhibit excellent CaCCs inhibition with IC50 value <6 ?M, with compound B25 exhibiting the lowest IC50 value of 2.8 ± 1.3 ?M. None of the tested ester analogs of final benzofuran derivatives displayed TMEM16A/CaCCs inhibition. PMID:22739085

Kumar, Satish; Namkung, Wan; Verkman, A. S.; Sharma, Pawan K.

2013-01-01

137

Effects of environmental calcium and phosphate on wear and strength of glass ionomers exposed to acidic conditions.  

PubMed

This study evaluated the effects of environmental calcium and phosphate on wear resistance, strength, and surface morphology of highly viscous glass-ionomers (HVGICs) (Fuji IX Fast [FN] and KetacMolar [KM]) when exposed to acidic conditions. Fabricated specimens were randomly divided into five groups and kept in acidic solutions (pH 3) with varied levels of calcium and phosphate ranging from 0 to 2.4 mM. After 4 weeks of conditioning, the specimens were subjected to wear testing, shear punch, and surface roughness testing as well as SEM evaluation. Multiple comparisons of wear depth (microm), shear strength (MPa), and surface roughness (Ra) between acidic conditions were performed using ANOVA/post-hoc Scheffe's test (p < 0.05). Results showed that FN and KM exposed to acidic conditions had varied wear resistance, shear strength, surface roughness, and structure depending on environmental phosphate level. Increased level of environmental phosphate led to rougher surface, greater wear resistance, and strength of FN and KM than the controls (acid of pH 3). Under SEM, the surface of both FN and KM specimens were covered by numerous small particles when environmental phosphate was high. Results suggest that environmental phosphate may improve wear resistance and shear strength of HVGICs when challenged by acids. PMID:18506830

Wang, X Y; Yap, Adrian U J

2009-02-01

138

Caffeic acid phenethyl ester prevents intestinal reperfusion injury in rats  

Microsoft Academic Search

Background\\/Purpose: Ischemia-reperfusion injury is encountered frequently in conditions that diminish intestinal blood flow. Caffeic acid phenethyl ester (CAPE), which is a specific component of the honeybee hive product propolis, exhibits potential antioxidant properties. This experimental study was designed to determine the effect of CAPE on ischemia-reperfusion injury in rat intestine.Methods: Fifty rats were divided into 5 groups; sham (SH), saline

U?ur Koltuksuz; Süleyman Özen; Efkan Uz; Mustafa Aydinç; Abdurrahman Karaman; Ahmet Gültek; Ömer Akyol; M. Harun Gürsoy; Engin Aydin

1999-01-01

139

Lysophosphatidic acid induces inositol phosphate and calcium signals in exocrine cells from the avian nasal salt gland  

Microsoft Academic Search

We tested lysophosphatidic acid (LPA), known to induce inositol phosphate generation and calcium signals as well as rearrangements of the cytoskeleton and mitogenic responses in fibroblasts, for its ability to activate phospholipase C in an exocrine cell system, the salt-secreting cells from the avian nasal salt gland. LPA (>10 nmol\\/l) caused the generation of inositol phosphates from membrane-bound phosphatidylinositides. The

J.-P. Hildebrandt

1995-01-01

140

Acid-induced gelation of whey protein polymers: effects of pH and calcium concentration during polymerization  

Microsoft Academic Search

Heating whey protein dispersions (90°C for 15 min) at low ionic strength and pH values far from isoelectric point (pH>6.5) induced the formation of soluble polymers. The effect of mineral environment during heating on the hydrodynamic characteristics and acid-induced gelation properties of polymers was studied. Whey protein dispersions (80g\\/l) were denatured at different pH (6.5–8.5) and calcium concentrations (0–4mm) according

Michel Britten; Hélène J Giroux

2001-01-01

141

ISOLATED MEDICAGO TRUNCATULA MUTANTS WITH INCREASED CALCIUM OXALATE CRYSTAL ACCUMULATION HAVE DECREASED ASCORBIC ACID LEVELS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The mechanisms controlling oxalate biosynthesis and calcium oxalate formation in plants remains largely unknown. As an initial step toward gaining insight into these regulatory mechanisms we initiated a mutant screen to identify plants that over-accumulate crystals of calcium oxalate. Four new mut...

142

Ruminal Biohydrogenation in Holstein Cows Fed Soybean Fatty Acids as Amides or Calcium Salts  

Microsoft Academic Search

Fatty amides of high oleate fats and calcium salts of palm oil were reported to resist biohydrogenation by ruminal microorganisms. This study was conducted to determine whether converting polyunsaturated fat sources to amides and calcium salts had equal ability to resist biohydrogenation. A total mixed ration con- sisting of forage and concentrate contained (dry basis): 1) 2.45% soybean oil (SBO),

F. P. Lundy III; E. Block; W. C. Bridges Jr.; J. A. Bertrand; T. C. Jenkins

2004-01-01

143

Development and characterization of an injectable cement of nano calcium-deficient hydroxyapatite/multi(amino acid) copolymer/calcium sulfate hemihydrate for bone repair.  

PubMed

A novel injectable bone cement was developed by integration of nano calcium-deficient hydroxyapatite/multi(amino acid) copolymer (n-CDHA/MAC) and calcium sulfate hemihydrate (CSH; CaSO4 · 1/2H2O). The structure, setting time, and compressive strength of the cement were investigated. The results showed that the cement with a liquid to powder ratio of 0.8 mL/g exhibited good injectability and appropriate setting time and mechanical properties. In vitro cell studies indicated that MC3T3-E1 cells cultured on the n-CDHA/MAC/CSH composite spread well and showed a good proliferation state. The alkaline phosphatase activity of the MC3T3-E1 cells cultured on the n-CDHA/MAC/CSH composite was significantly higher than that of the cells on pure CSH at 4 and 7 days of culture. The n-CDHA/MAC/CSH cement was implanted into critical size defects of the femoral condyle in rabbits to evaluate its biocompatibility and osteogenesis in vivo. Radiological and histological results indicated that introduction of the n-CDHA/MAC into CSH enhanced new bone formation, and the n-CDHA/MAC/CSH cement exhibited good biocompatibility and degradability. In conclusion, the injectable n-CDHA/MAC/CSH composite cement has a significant clinical advantage over pure CSH cement, and may be a promising bone graft substitute for the treatment of bone defects. PMID:24293996

Qi, Xiaotong; Li, Hong; Qiao, Bo; Li, Weichao; Hao, Xinyan; Wu, Jun; Su, Bao; Jiang, Dianming

2013-01-01

144

Development and characterization of an injectable cement of nano calcium-deficient hydroxyapatite/multi(amino acid) copolymer/calcium sulfate hemihydrate for bone repair  

PubMed Central

A novel injectable bone cement was developed by integration of nano calcium-deficient hydroxyapatite/multi(amino acid) copolymer (n-CDHA/MAC) and calcium sulfate hemihydrate (CSH; CaSO4 · 1/2H2O). The structure, setting time, and compressive strength of the cement were investigated. The results showed that the cement with a liquid to powder ratio of 0.8 mL/g exhibited good injectability and appropriate setting time and mechanical properties. In vitro cell studies indicated that MC3T3-E1 cells cultured on the n-CDHA/MAC/CSH composite spread well and showed a good proliferation state. The alkaline phosphatase activity of the MC3T3-E1 cells cultured on the n-CDHA/MAC/CSH composite was significantly higher than that of the cells on pure CSH at 4 and 7 days of culture. The n-CDHA/MAC/CSH cement was implanted into critical size defects of the femoral condyle in rabbits to evaluate its biocompatibility and osteogenesis in vivo. Radiological and histological results indicated that introduction of the n-CDHA/MAC into CSH enhanced new bone formation, and the n-CDHA/MAC/CSH cement exhibited good biocompatibility and degradability. In conclusion, the injectable n-CDHA/MAC/CSH composite cement has a significant clinical advantage over pure CSH cement, and may be a promising bone graft substitute for the treatment of bone defects. PMID:24293996

Qi, Xiaotong; Li, Hong; Qiao, Bo; Li, Weichao; Hao, Xinyan; Wu, Jun; Su, Bao; Jiang, Dianming

2013-01-01

145

Regulation of the synthesis of barley aleurone. cap alpha. -amylase by gibberellic acid and calcium ions  

SciTech Connect

The effects of gibberellic acid (GA/sub 3/) and calcium ions on the production of ..cap alpha..-amylase and acid phosphatase by isolated aleurone layers of barley (Hordeum vulgare L. cv Himalaya) were studied. Aleurone layers not previously exposed to GA/sub 3/ or CA/sup 2 +/ show qualitative and quantitative changes in hydrolase production following incubation in either GA/sub 3/ or CA/sup 2 +/ or both. In cubation in H/sub 2/O or CA/sup 2 +/ results in the production of low levels of ..cap alpha..-amylase or acid phosphatase. The addition of GA/sub 3/ to the incubation medium causes 10- to 20-fold increase in the amounts of these enzymes released from the tissue, and addition of CA/sup 2 +/ at 10 millimolar causes a further 8- to 9-fold increase in ..cap alpha..-amylase release and a 75% increase in phosphatase release. Production of ..cap alpha..-amylase isoenzymes is also modified by the levels of GA/sub 3/ and CA/sup 2 +/ in the incubation medium. ..cap alpha..-amylase 2 is produced under all conditions of incubation, while ..cap alpha..-amylase 1 appears only when layers are incubated in GA/sub 3/ or GA/sub 3/ plus CA/sup 2 +/. The synthesis of ..cap alpha..-amylases 3 and 4 requires the presence of both GA/sub 3/ and CA/sup 2 +/ in the incubation medium. Laurell rocket immunoelectrophoresis shows that two distinct groups of ..cap alpha..-amylase antigens are present in incubation media of aleurone layers incubated with both GA/sub 3/ and CA/sup 2 +/, while only one group of antigens is found in media of layers incubated in GA/sub 3/ alone. Strontium ions can be substituted for CA/sup 2 +/ in increasing hydrolase production, although higher concentrations of Sr/sup 2 +/ are requried for maximal response. We conclude that GA/sub 3/ is required for the production of ..cap alpha..-amylase 1 and that both GA/sub 3/ and either CA/sup 2 +/ or Sr/sup 2 +/ are required for the production of isoenzymes 3 and 4 of barley aleurone ..cap alpha..-amylase. 22 references, 8 figures, 1 tables.

Jones, R.L.; Carbonell, J.

1984-09-01

146

Calcium-Dependent and Calcium-Independent Events in the Initiation of Stomatal Closure by Abscisic Acid  

Microsoft Academic Search

The signal transduction mechanisms by which abscisic acid (ABA) induces net loss of potassium salts from guard cells and closes stomata are not understood. This paper describes the detailed timecourse of the ABA-induced K+(Rb+) efflux transient in guard cells of Commelina communis L. and its dependence on external Ca2+, and compares the effects of short pulses of ABA with that

E. A. C. MacRobbie

1990-01-01

147

The role of calcium in growth induced by indole-3-acetic acid and gravity in the leaf-sheath pulvinus of oat (Avena sativa)  

NASA Technical Reports Server (NTRS)

Leaf-sheath pulvini of excised segments from oat (Avena sativa L.) were induced to grow by treatment with 10 micromoles indole-3-acetic acid (IAA), gravistimulation, or both, and the effects of calcium, EGTA, and calcium channel blockers on growth were evaluated. Unilaterally applied calcium (10 mM CaCl2) significantly inhibited IAA-induced growth in upright pulvini but had no effect on growth induced by either gravity or gravity plus IAA. Calcium alone had no effect on upright pulvini. The calcium chelator EGTA alone (10 mM) stimulated growth in upright pulvini. However, EGTA had no effect on either IAA- or gravity-induced growth but slightly diminished growth in IAA-treated gravistimulated pulvini. The calcium channel blockers lanthanum chloride (25 mM), verapamil (2.5 mM), and nifedipine (2.5 mM) greatly inhibited growth as induced by IAA (> or = 50% inhibition) or IAA plus gravity (20% inhibition) but had no effect on gravistimulated pulvini. Combinations of channel blockers were similar in effect on IAA action as individual blockers. Since neither calcium ions nor EGTA significantly affected the graviresponse of pulvini, we conclude that apoplastic calcium is unimportant in leaf-sheath pulvinus gravitropism. The observation that calcium ions and calcium channel blockers inhibit IAA-induced growth, but have no effect on gravistimulated pulvini, further supports previous observations that gravistimulation alters the responsiveness of pulvini to IAA.

Brock, T. G.; Burg, J.; Ghosheh, N. S.; Kaufman, P. B.

1992-01-01

148

Bioefficacy of a novel calcium-potassium salt of (-)-hydroxycitric acid.  

PubMed

Obesity is associated with cardiovascular disease, diabetes and certain forms of cancer. Popular strategies on weight loss often fail to address many key factors such as fat mass, muscle density, bone density, water mass, their inter-relationships and impact on energy production, body composition, and overall health and well-being. (-)-Hydroxycitric acid (HCA), a natural plant extract from the dried fruit rind of Garcinia cambogia, has been reported to promote body fat loss in humans without stimulating the central nervous system. The level of effectiveness of G. cambogia extract is typically attributed solely to HCA. However, other components by their presence or absence may significantly contribute to its therapeutic effectiveness. Typically, HCA used in dietary weight loss supplement is bound to calcium, which results in a poorly soluble (<50%) and less bioavailable form. Conversely, the structural characteristics of a novel Ca2+/K+ bound (-)-HCA salt (HCA-SX or Super CitriMax) make it completely water soluble as well as bioavailable. An efficacious dosage of HCA-SX (4500 mg/day t.i.d.) provides a good source of Ca2+ (495 mg, 49.5% of RDI) and K+ (720 mg, 15% of RDI). Ca2+ ions are involved in weight management by increasing lipid metabolism, enhancing thermogenesis, and increasing bone density. K+, on the other hand, increases energy, reduces hypertension, increases muscle strength and regulates arrhythmias. Both Ca and K act as buffers in pH homeostasis. HCA-SX has been shown to increase serotonin availability, reduce appetite, increase fat oxidation, improve blood lipid levels, reduce body weight, and modulate a number of obesity regulatory genes without affecting the mitochondrial and nuclear proteins required for normal biochemical and physiological functions. PMID:16055158

Downs, Bernard W; Bagchi, Manashi; Subbaraju, Gottumukkala V; Shara, Michael A; Preuss, Harry G; Bagchi, Debasis

2005-11-11

149

Overexpression of a Calcium-Dependent Protein Kinase Confers Salt and Drought Tolerance in Rice by Preventing Membrane Lipid Peroxidation.  

PubMed

The OsCPK4 gene is a member of the complex gene family of calcium-dependent protein kinases in rice (Oryza sativa). Here, we report that OsCPK4 expression is induced by high salinity, drought, and the phytohormone abscisic acid. Moreover, a plasma membrane localization of OsCPK4 was observed by transient expression assays of green fluorescent protein-tagged OsCPK4 in onion (Allium cepa) epidermal cells. Overexpression of OsCPK4 in rice plants significantly enhances tolerance to salt and drought stress. Knockdown rice plants, however, are severely impaired in growth and development. Compared with control plants, OsCPK4 overexpressor plants exhibit stronger water-holding capability and reduced levels of membrane lipid peroxidation and electrolyte leakage under drought or salt stress conditions. Also, salt-treated OsCPK4 seedlings accumulate less Na(+) in their roots. We carried out microarray analysis of transgenic rice overexpressing OsCPK4 and found that overexpression of OsCPK4 has a low impact on the rice transcriptome. Moreover, no genes were found to be commonly regulated by OsCPK4 in roots and leaves of rice plants. A significant number of genes involved in lipid metabolism and protection against oxidative stress appear to be up-regulated by OsCPK4 in roots of overexpressor plants. Meanwhile, OsCPK4 overexpression has no effect on the expression of well-characterized abiotic stress-associated transcriptional regulatory networks (i.e. ORYZA SATIVA DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN1 and ORYZA SATIVA No Apical Meristem, Arabidopsis Transcription Activation Factor1-2, Cup-Shaped Cotyledon6 genes) and LATE EMBRYOGENESIS ABUNDANT genes in their roots. Taken together, our data show that OsCPK4 functions as a positive regulator of the salt and drought stress responses in rice via the protection of cellular membranes from stress-induced oxidative damage. PMID:24784760

Campo, Sonia; Baldrich, Patricia; Messeguer, Joaquima; Lalanne, Eric; Coca, María; San Segundo, Blanca

2014-05-01

150

[Folic acid use by pregnant women in Israel for preventing neural tube defects].  

PubMed

Spina bifida and anencephaly are the most common, serious malformations in neural tube defects (NTD). Randomized trials in the last 2 decades have demonstrated that folic acid, 0.4 mg/d, reduces the incidence of NTD by more than 50%. We investigated the use of folic acid and multivitamins containing folic acid in childbearing women. Of 221 women interviewed, 67 (30%) regularly took pills containing 0.4 mg folic acid. Women with higher educational levels were more likely to take multivitamins with folic acid than were the less educated (p = 0.05). Of the women who took folic acid, only 5 (7.5%) used separate folic acid tablets, before and during their pregnancy. The rest used multivitamins containing folic acid. The 5 women who took folic acid separately were college-educated and nonreligious, and they took multivitamins in addition (p > 0.05). Of the women interviewed, 58 (26.2%) were Bedouin of the Negev. 24 (41.4%) of them took pills containing folic acid on a regular basis. This percentage is higher than that in the Jewish women in the study who took folic acid for prevention of NTD (17%; p = 0.038). Most of the women took folic acid after the first trimester. Only a minority took daily periconceptional folic acid. Multivitamins containing 0.4 mg of folic acid were more popular than folic acid tablets alone. This study emphasizes the need for continuing efforts to increase consumption of folic acid and awareness of its benefits among women of childbearing age. PMID:11341184

Gil, Z; Aran, A; Friedman, O; Beni-Adani, L; Constantini, S

2000-12-01

151

A field study of constructed wetlands for preventing and treating acid mine drainage  

Microsoft Academic Search

The formation of acid mine drainage (AMD) from mine tailings is a severe environmental problem associated with tailings impoundments. The study evaluated the ability of wetlands built on tailings impoundments to prevent AMD formation and to treat already formed AMD, with special emphasis on the role of wetland plants in the remediation process. Four small-scale surface-flow wetlands of different designs,

Johanna Nyquist; Maria Greger

2009-01-01

152

Hydrophilic but not hydrophobic bile acids prevent gallbladder muscle dysfunction in acute cholecystitis.  

PubMed

The pathogenesis of acute cholecystitis (AC) is controversial. Bile acids may be involved in the pathogenesis of AC because the hydrophobic chenodeoxycholic acid (CDCA) reproduced in vitro the muscle dysfunction observed in AC and was prevented by the hydrophilic ursodeoxycholic acid (UDCA). The present study examined the in vivo effects of UDCA or CDCA on gallbladder muscle dysfunction caused by AC. Guinea pigs were treated with placebo, UDCA, or CDCA for 2 weeks before sham operation or induction of AC by bile duct ligation (BDL) for 3 days. Pretreatment with oral UDCA prevented the defective contraction in response to agonists (acetylcholine [ACh], cholecystokinin 8 [CCK-8], and KCl) that occurs after BDL. Prostaglandin (PG) E(2)-induced contraction remained normal in the placebo and UDCA-treated groups but was impaired in the CDCA-treated group. Treatment with UDCA also prevented the expected increase in the levels of H(2)O(2), lipid peroxidation, and PGE(2) content in the placebo-treated AC group, whereas CDCA caused further increases in these oxidative stress markers. The binding capacity of PGE(2) to its receptors and the activity of catalase were reduced after treatment with CDCA. Treatment with UDCA enriched gallbladder bile acids with its conjugates and reduced the percentage of CDCA conjugates. In contrast, treatment with CDCA significantly decreased the percentage of UDCA in bile. In conclusion, oral treatment with UDCA prevents gallbladder muscle damage caused by BDL, whereas oral treatment with CDCA worsens the defective muscle contractility and the oxidative stress. PMID:12774024

Xiao, Zuo-Liang; Biancani, Piero; Carey, Martin C; Behar, Jose

2003-06-01

153

21 CFR 184.1195 - Calcium citrate.  

Code of Federal Regulations, 2010 CFR

...acid. It is prepared by neutralizing citric acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder and usually contains four moles of water per mole of calcium citrate. (b) The ingredient...

2010-04-01

154

Stimulation of carbohydrate metabolism reduces hypothermia-induced calcium load in fatty acid-perfused rat hearts.  

PubMed

In the present study we examined the impact of glycolysis and glucose oxidation on myocardial calcium control and mechanical function of fatty acid-perfused rat hearts subjected to hypothermia rewarming. One group (control) was given glucose (11.1 mM) and palmitate (1.2 mM) as energy substrates. In a second group glycolysis was inhibited by iodoacetate (IAA, 100 microM) and replacement of glucose with pyruvate (5 mM), whereas in the third group glucose oxidation was stimulated by administration of dichloroacetate (DCA, 1 mM) and insulin (500 microU/ml). All groups showed a rise in myocardial calcium ([Ca]total in response to hypothermia (10 degrees C). However, [Ca]total was significantly lower both in IAA- and DCA-treated hearts, as compared to controls (2.20 +/- 0.22 and 2.94 +/- 0.20 v 3.83 +/- 0.29 nmol/mg dry wt., P < 0.025). The reduced calcium load in the treated hearts was correlated with higher levels of high energy phosphates. Following rewarming control and DCA-treated hearts still showed elevated [Ca]total, whereas IAA-treated hearts [Ca]total was not different from the pre-hypothermic value. All groups showed a reduction in cardiac output following rewarming. Furthermore, the control group, in contrast to both IAA- and DCA-treated hearts, showed a significant reduction in systolic pressure. These results show that hypothermia-induced calcium uptake in glucose and fatty acid-perfused rat hearts was reduced by two different metabolic approaches: (1) inhibition of glycolysis by IAA while simultaneously by-passing the glycolytic pathway by exogenous pyruvate: and (2) stimulation of glucose oxidation by DCA. Thus, glycolytic ATP is not an essential regulator of sarcolemmal calcium transport under the present experimental conditions. Instead, we suggest that a change in oxidative substrate utilization in favour of carbohydrates may improve myocardial calcium homeostasis during hypothermia and rewarming. PMID:9140812

Aasum, E; Steigen, T K; Larsen, T S

1997-02-01

155

Preventive Effects of Folic Acid Supplementation on Adverse Maternal and Fetal Outcomes  

PubMed Central

Although there is accumulating evidence regarding the additional protective effect of folic acid against adverse pregnancy outcomes other than neural tube defects, these effects have not been elucidated in detail. We evaluated whether folic acid supplementation is associated with favorable maternal and fetal outcomes. This was a secondary analysis of 215 pregnant women who were enrolled in our prior study. With additional data from telephone interviews regarding prenatal folic acid supplementation, existing demographic, maternal and fetal data were statistically analyzed. The concentration of folic acid in maternal blood was significantly higher following folic acid supplementation (24.6 ng/mL vs.11.8 ng/mL). In contrast, homocysteine level in maternal blood decreased with folic acid supplementation (5.5 µmol/mL vs. 6.8 µmol/mL). The rates of both preeclampsia (odds ratio [OR], 0.27; 95% confidence interval [CI], 0.09–0.76) and small for gestational age (SGA; 9.2% vs. 20.0%; OR, 0.42; 95% CI, 0.18–0.99) were lower in the folic acid supplementation group than those in the control group. Other pregnancy outcomes had no association with folic acid supplementation. The findings indicate that folic acid supplementation may help to prevent preeclampsia and SGA. Further studies are warranted to elucidate the favorable effects of folic acid supplementation on pregnancy outcomes. PMID:24842467

Kim, Min Woo; Ahn, Ki Hoon; Ryu, Ki-Jin; Hong, Soon-Cheol; Lee, Ji Sung; Nava-Ocampo, Alejandro A.; Oh, Min-Jeong; Kim, Hai-Joong

2014-01-01

156

Preventive effects of folic acid supplementation on adverse maternal and fetal outcomes.  

PubMed

Although there is accumulating evidence regarding the additional protective effect of folic acid against adverse pregnancy outcomes other than neural tube defects, these effects have not been elucidated in detail. We evaluated whether folic acid supplementation is associated with favorable maternal and fetal outcomes. This was a secondary analysis of 215 pregnant women who were enrolled in our prior study. With additional data from telephone interviews regarding prenatal folic acid supplementation, existing demographic, maternal and fetal data were statistically analyzed. The concentration of folic acid in maternal blood was significantly higher following folic acid supplementation (24.6 ng/mL vs.11.8 ng/mL). In contrast, homocysteine level in maternal blood decreased with folic acid supplementation (5.5 µmol/mL vs. 6.8 µmol/mL). The rates of both preeclampsia (odds ratio [OR], 0.27; 95% confidence interval [CI], 0.09-0.76) and small for gestational age (SGA; 9.2% vs. 20.0%; OR, 0.42; 95% CI, 0.18-0.99) were lower in the folic acid supplementation group than those in the control group. Other pregnancy outcomes had no association with folic acid supplementation. The findings indicate that folic acid supplementation may help to prevent preeclampsia and SGA. Further studies are warranted to elucidate the favorable effects of folic acid supplementation on pregnancy outcomes. PMID:24842467

Kim, Min Woo; Ahn, Ki Hoon; Ryu, Ki-Jin; Hong, Soon-Cheol; Lee, Ji Sung; Nava-Ocampo, Alejandro A; Oh, Min-Jeong; Kim, Hai-Joong

2014-01-01

157

The Ability of PAS, Acetylsalicylic Acid and Calcium Disodium EDTA to Protect Against the Toxic Effects of Manganese on Mitochondrial Respiration in Gill of Crassostrea virginica  

PubMed Central

Manganese (Mn) is an essential metal that at excessive levels in brain causes Manganism, a condition similar to Parkinson's disease. Previously we showed that Mn had a neurotoxic effect on the dopaminergic, but not serotonergic, innervation of the lateral ciliated cells in the gill of the Eastern Oyster, Crassostrea virginica. While the mechanism of action of Mn toxicity is not completely understood, studies suggest that Mn toxicity may involve mitochondrial damage and resulting neural dysfunction in the brain’s dopaminergic system. In this study we utilized micro-batch chambers and oxygen probes to measure oyster gill mitochondrial respiration in the presence of Mn and potential Mn blockers. The addition of Mn to respiring mitochondria caused a dose dependent decrease in mitochondrial O2 consumption. Pretreating mitochondria with calcium disodium EDTA (caEDTA), p aminosalicylic acid (PAS) or acetylsalicylic acid (ASA) before Mn additions, provided full protection against the toxic effects of Mn. While mitochondrial pretreatment with any of the 3 drugs effectively blocked Mn toxicity, none of the drugs tested was able to reverse the decrease in mitochondrial O2 consumption seen in Mn treated mitochondria. The study found that high levels of Mn had a toxic effect on gill mitochondrial O2 consumption and that this effect could be blocked by the drugs caEDTA, PAS and ASA. C. virginica continues to be a good model with which to investigate the mechanism that underlies manganese neurotoxcity and in the pharmacological study of drugs to treat or prevent Manganism. PMID:21977482

Crawford, Sherine; Davis, Kiyya; Saddler, Claudette; Joseph, Jevaun; Catapane, Edward J.; Carroll, Margaret A.

2011-01-01

158

The Ability of PAS, Acetylsalicylic Acid and Calcium Disodium EDTA to Protect Against the Toxic Effects of Manganese on Mitochondrial Respiration in Gill of Crassostrea virginica.  

PubMed

Manganese (Mn) is an essential metal that at excessive levels in brain causes Manganism, a condition similar to Parkinson's disease. Previously we showed that Mn had a neurotoxic effect on the dopaminergic, but not serotonergic, innervation of the lateral ciliated cells in the gill of the Eastern Oyster, Crassostrea virginica. While the mechanism of action of Mn toxicity is not completely understood, studies suggest that Mn toxicity may involve mitochondrial damage and resulting neural dysfunction in the brain's dopaminergic system. In this study we utilized micro-batch chambers and oxygen probes to measure oyster gill mitochondrial respiration in the presence of Mn and potential Mn blockers. The addition of Mn to respiring mitochondria caused a dose dependent decrease in mitochondrial O(2) consumption. Pretreating mitochondria with calcium disodium EDTA (caEDTA), p aminosalicylic acid (PAS) or acetylsalicylic acid (ASA) before Mn additions, provided full protection against the toxic effects of Mn. While mitochondrial pretreatment with any of the 3 drugs effectively blocked Mn toxicity, none of the drugs tested was able to reverse the decrease in mitochondrial O(2) consumption seen in Mn treated mitochondria. The study found that high levels of Mn had a toxic effect on gill mitochondrial O(2) consumption and that this effect could be blocked by the drugs caEDTA, PAS and ASA. C. virginica continues to be a good model with which to investigate the mechanism that underlies manganese neurotoxcity and in the pharmacological study of drugs to treat or prevent Manganism. PMID:21977482

Crawford, Sherine; Davis, Kiyya; Saddler, Claudette; Joseph, Jevaun; Catapane, Edward J; Carroll, Margaret A

2011-01-01

159

Effects of unsaturated fatty acids on calcium-activated potassium current in gastric myocytes of guinea pigs  

PubMed Central

AIM: To investigate the effects of exogenous unsaturated fatty acids on calcium-activated potassium current [IK(Ca)] in gastric antral circular myocytes of guinea pigs. METHODS: Gastric myocytes were isolated by collagenase from the antral circular layer of guinea pig stomach. The whole-cell patch clamp technique was used to record IK(Ca) in the isolated single smooth muscle cells with or without different concentrations of arachidonic acid (AA), linoleic acid (LA), and oleic acid (OA). RESULTS: AA at concentrations of 2,5 and 10 ?mol/L markedly increased IK(Ca) in a dose-dependent manner. LA at concentrations of 5, 10 and 20 ?mol/L also enhanced IK(Ca) in a dose-dependent manner. The increasing potency of AA, LA, and oleic acid (OA) on IK(Ca) at the same concentration (10 ?mol/L) was in the order of AA>LA>OA. AA (10 ?mol/L)-induced increase of IK(Ca) was not blocked by H-7 (10 ?mol/L), an inhibitor of protein kinase C (PKC), or indomethacin (10 ?mol/L), an inhibitor of the cyclooxygenase pathway, and 17-octadecynoic acid (10 ?mol/L), an inhibitor of the cytochrome P450 pathway, but weakened by nordihydroguaiaretic acid (10 ?mol/L), an inhibitor of the lipoxygenase pathway. CONCLUSION: Unsaturated fatty acids markedly increase IK(Ca), and the enhancing potencies are related to the number of double bonds in the fatty acid chain. The lipoxygenase pathway of unsaturated fatty acid metabolism is involved in the unsaturated fatty acid-induced increase of IK(Ca) in gastric antral circular myocytes of guinea pigs. PMID:15655819

Zheng, Hai-Feng; Li, Xiang-Lan; Jin, Zheng-Yuan; Sun, Jia-Bin; Li, Zai-Liu; Xu, Wen-Xie

2005-01-01

160

Preventive role of gallic acid on alcohol dependent and cysteine protease-mediated pancreas injury.  

PubMed

In order to investigate an association between alcohol consumption and lysosomal cysteine protease induced pancreatic injury and preventive effect of gallic acid as dose-dependent, we determined myeloperoxidase and malondialdehyde levels, serum amylase activities and cathepsin B and L activities in the cytosolic and lysosomal fractions of pancreatic tissue in the ethanol (8 g/kg) and ethanol plus gallic acid (at different doses 50, 100 and 200 mg/kg) given rats. Absolute ethanol (8 g/kg) was given by oral gavage. Gallic acid was dissolved in the saline (2 ml/kg) and administered before 30 min the oral administration of ethanol. Pancreatic myeloperoxidase and also malondialdehyde levels and serum amylase activities were measured. Besides, histological investigations were made. Cathepsin B activities in the cytosolic fraction were decreased by gallic acid (200 mg/kg) and increased in ethanol given rats. Cytosolic/lysosomal ratio of cathepsin B and L were found to be low in the all doses of gallic acid as compared to ethanol group. Serum amylase, pancreatic myeloperoxidase activities and malondialdehyde levels in the ethanol group were higher than in the control group. These were not statistically significant for myeloperoxidase and malondialdehyde. Also, our histopathologic results indicated that ethanol administration increased pancreatic tissue injury. Gallic acid especially at 200 mg/kg improved ethanol-mediated pancreatic tissue damage.In conclusion, gallic acid treatments were decreased release of lysosomal cathepsin B and L enzymes into cytoplasmic fraction and prevented alcohol mediated pancreatic tissue injury. Preventive effect of gallic acid might be dose-dependent. PMID:23053933

Kanbak, Güngör; Canbek, Mediha; O?lakç?, Ay?egül; Kartkaya, Kazim; Sentürk, Hakan; Bayramo?lu, Gökhan; Bal, Cengiz; Göl, Burak; Ozmen, Ay?e

2012-12-01

161

Cancer Preventive Potential of Kimchi Lactic Acid Bacteria (Weissella cibaria, Lactobacillus plantarum)  

PubMed Central

The number of death due to cancer has been increasing in Korea. Chemotherapy is known to cause side effects because it damages not only cancerous cells but healthy cells. Recently, attention has focused on food-derived chemopreventive and anti-tumor agents or formulations with fewer side effects. Kimchi, most popular and widely consumed in Korea, contains high levels of lactic acid bacteria and has been shown to possess chemopreventive effects. This review focuses on Weissella cibaria and Lactobacillus plantarum, the representatives of kimchi lactic acid bacteria, in terms of their abilities to prevent cancer. Further studies are needed to understand the mechanisms by which lactic acid bacteria in kimchi prevent carcinogenic processes and improve immune functions. PMID:25574459

Kwak, Shin-Hye; Cho, Young-Mi; Noh, Geon-Min; Om, Ae-Son

2014-01-01

162

In Barrett's esophagus patients and Barrett's cell lines, ursodeoxycholic acid increases antioxidant expression and prevents DNA damage by bile acids.  

PubMed

Hydrophobic bile acids like deoxycholic acid (DCA), which cause oxidative DNA damage and activate NF-?B in Barrett's metaplasia, might contribute to carcinogenesis in Barrett's esophagus. We have explored mechanisms whereby ursodeoxycholic acid (UDCA, a hydrophilic bile acid) protects against DCA-induced injury in vivo in patients and in vitro using nonneoplastic, telomerase-immortalized Barrett's cell lines. We took biopsies of Barrett's esophagus from 21 patients before and after esophageal perfusion with DCA (250 ?M) at baseline and after 8 wk of oral UDCA treatment. DNA damage was assessed by phospho-H2AX expression, neutral CometAssay, and phospho-H2AX nuclear foci formation. Quantitative PCR was performed for antioxidants including catalase and GPX1. Nrf2, catalase, and GPX1 were knocked down with siRNAs. Reporter assays were performed using a plasmid construct containing antioxidant responsive element. In patients, baseline esophageal perfusion with DCA significantly increased phospho-H2AX and phospho-p65 in Barrett's metaplasia. Oral UDCA increased GPX1 and catalase levels in Barrett's metaplasia and prevented DCA perfusion from inducing DNA damage and NF-?B activation. In cells, DCA-induced DNA damage and NF-?B activation was prevented by 24-h pretreatment with UDCA, but not by mixing UDCA with DCA. UDCA activated Nrf2 signaling to increase GPX1 and catalase expression, and protective effects of UDCA pretreatment were blocked by siRNA knockdown of these antioxidants. UDCA increases expression of antioxidants that prevent toxic bile acids from causing DNA damage and NF-?B activation in Barrett's metaplasia. Elucidation of this molecular pathway for UDCA protection provides rationale for clinical trials on UDCA for chemoprevention in Barrett's esophagus. PMID:24852569

Peng, Sui; Huo, Xiaofang; Rezaei, Davood; Zhang, Qiuyang; Zhang, Xi; Yu, Chunhua; Asanuma, Kiyotaka; Cheng, Edaire; Pham, Thai H; Wang, David H; Chen, Minhu; Souza, Rhonda F; Spechler, Stuart Jon

2014-07-15

163

Surface properties of calcium and magnesium oxide nanopowders grafted with unsaturated carboxylic acids studied with inverse gas chromatography.  

PubMed

Inverse gas chromatography (IGC) was applied at infinite dilution to evaluate the surface properties of calcium and magnesium oxide nanoparticles and the effect of surface grafted unsaturated carboxylic acid on the nanopowder donor-acceptor characteristics. The dispersive components (?(s)(D)) of the free energy of the nanopowders were determined by Gray's method, whereas their tendency to undergo specific interactions was estimated based on the electron donor-acceptor approach presented by Papirer. The calcium and magnesium oxide nanoparticles exhibited high surface energies (79 mJ/m² and 74 mJ/m², respectively). Modification of nanopowders with unsaturated carboxylic acids decreased their specific adsorption energy. The lowest value of ?(s)(D) was determined for nanopowders grafted with undecylenic acid, approximately 55 mJ/m². The specific interactions were characterised by the molar free energy (?G(A)(SP)) and molar enthalpy (?H(A)(SP)) of adsorption as well as the donor and acceptor interaction parameters (K(A), K(D)). PMID:22907042

Maciejewska, Magdalena; Krzywania-Kaliszewska, Alicja; Zaborski, Marian

2012-09-28

164

Impacts of calcium signal transduction on the fermentation production of antitumor ganoderic acids by medicinal mushroom Ganoderma lucidum.  

PubMed

Recently signal transduction engineering of secondary metabolism is receiving great interest as a powerful tool towards efficient production of valuable secondary metabolites. This work found that the calcineurin-signal transduction was significant to triterpene biosynthesis by higher fungus (mushroom). Addition of calcium ion (at 10mM) to static liquid cultures of Ganoderma lucidum, a famous traditional medicinal mushroom, was proved as a useful strategy to enhance the production of antitumor ganoderic acids (GAs), which resulted in 3.7-, 2.6-, 4.5-, 3.2- and 3.8-fold improvement of total GAs, individual GA-Mk, -T, -S, and -Me, respectively. Experiments using Ca2+ sensor inhibitors indicated the involvement of calcineurin signal in regulating GAs biosynthesis. Quantitative gene transcription analysis revealed that the expression levels of genes of GAs biosynthesis and Ca2+ sensor were up-regulated with calcium addition while down-regulated under the inhibitors addition, suggesting that higher GAs production may be resulted from higher expressions of those genes. Based on the results obtained, a possible model on the effect of external calcium ion on the GAs biosynthesis via calcineurin signal transduction pathway was proposed. PMID:22036615

Xu, Yi-Ning; Zhong, Jian-Jiang

2012-01-01

165

Absorption of calcium and magnesium in patients with intestinal resections treated with medium chain fatty acids  

PubMed Central

BACKGROUND—Steatorrhoea is associated with increased faecal loss of calcium and magnesium. Medium chain C8-C10 triglycerides (MCTs) improve fat absorption in patients with small bowel resections but the effects on intestinal absorption of divalent cations are not clear.?AIM—To assess the effect of dietary replacement of long chain triglycerides (LCTs) with MCTs on calcium and magnesium absorption in patients with small bowel resections.?PATIENTS—Nineteen adult patients with a remaining small intestine averaging 171 cm (range 50-300).?METHODS—In a crossover design, patients were randomised to two high fat diets (10 MJ/day, 50% as fat) for four days each separated by one day of washout. Diets were prepared in duplicate and were based on either LCT (LCT period) or equal quantities of LCT and MCT (L/MCT period). Metabolic balances were calculated during the last three days of each period.?RESULTS—Mean stool volume increased significantly with the L/MCT diet and was 336 ml more than that with the LCT diet (95% confidence interval of mean difference, 26-649 ml). There was no significant change in the net absorption of calcium and magnesium between the two diets. On average, percentage calcium absorption was 8.6% with the LCT diet and 12.5% with the L/MCT diet. Mean percentage magnesium absorption was 5.4% with the LCT diet and 2.9% with the L/MCT diet.?CONCLUSIONS—Dietary replacement of 50% long chain triglycerides with medium chain triglycerides in small bowel resected patients increased faecal volume significantly. No changes in the intestinal net absorption of calcium and magnesium were demonstrated.???Keywords: medium chain triglycerides; calcium absorption; magnesium absorption; intestinal resections; fat absorption PMID:10807894

Haderslev, K; Jeppesen, P; Mortensen, P; Staun, M

2000-01-01

166

The Effect of varying ratios of docosahexaenoic Acid and arachidonic acid in the prevention and reversal of biochemical essential fatty acid deficiency in a murine model  

PubMed Central

Objective Essential fatty acids (EFA) are necessary for growth, development, and biological function, and must be acquired through the diet. While linoleic acid (LA) and alpha-linolenic acid (ALA) have been considered the true EFAs, we previously demonstrated that docosahexaenoic acid (DHA) and arachidonic acid (AA) taken together as the sole source of dietary fatty acids can prevent biochemical essential fatty acid deficiency (EFAD). This study evaluates the effect of varying dietary ratios of DHA:AA in the prevention and reversal of biochemical EFAD in a murine model. Methods Using a murine model of EFAD, we provided mice with 2.1% of daily caloric intake in varying DHA:AA ratios (1:1, 5:1, 10:1, 20:1, 200:1, 100:0) for 19 days in association with a liquid high-carbohydrate fat-free diet to evaluate the effect on fatty acid profiles. In a second experiment, we evaluated the provision of varying DHA:AA ratios (20:1, 200:1, 100:0) on the reversal of biochemical EFAD. Results Mice provided with DHA and AA had no evidence of biochemical EFAD, regardless of the ratio (1:1, 5:1, 10:1, 20:1, 200:1, 100:0) administered. Biochemical EFAD was reversed with DHA:AA ratios of 20:1, 200:1, and 100:0 following 3 and 5 weeks of dietary provision, although the 20:1 ratio was most effective in the reversal and stabilization of the triene:tetraene ratio. Conclusion Provision of DHA and AA, at 2.1% of daily caloric intake in varying ratios can prevent biochemical evidence of EFAD and hepatic steatosis over the short-term, with a ratio of 20:1 DHA:AA most effectively reversing EFAD. PMID:23151438

Le, Hau D.; Fallon, Erica M.; Kalish, Brian T.; de Meijer, Vincent E.; Meisel, Jonathan A.; Gura, Kathleen M.; Nose, Vania; Pan, Amy H.; Bistrian, Bruce R.; Puder, Mark

2012-01-01

167

Calcium Sulfate Formation and Mitigation when Seawater was Used to Prepare HCl-Based Acids  

E-print Network

with sulfate ion in seawater (greater than 3000 ppm) and calcium sulfate will precipitate once it exceeds its critical scaling tendency. A few studies have provided evidence for this problem and how to address this problem has not been fully examined. Core...

He, Jia

2012-02-14

168

Pretreatment of solid carbonaceous material with dicarboxylic aromatic acids to prevent scale formation  

SciTech Connect

Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with a pretreating agent selected from the group consisting of phthalic acid, phthalic anhydride, pyromellitic acid and pyromellitic anhydride. The pretreatment is believed to convert the scale-forming components to the corresponding phthalate and/or pyromellitate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 1 to about 2 atmospheres. Temperature during pretreatment will generally be within the range from about 5 to about 80/sup 0/ C.

Brunson, R.J.

1982-06-01

169

Pretreatment of solid carbonaceous material with dicarboxylic aromatic acids to prevent scale formation  

DOEpatents

Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with a pretreating agent selected from the group consisting of phthalic acid, phthalic anhydride, pyromellitic acid and pyromellitic anhydride. The pretreatment is believed to convert the scale-forming components to the corresponding phthalate and/or pyromellitate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 1 to about 2 atmospheres. Temperature during pretreatment will generally be within the range from about 5.degree. to about 80.degree. C.

Brunson, Roy J. (Buffalo Grove, IL)

1982-01-01

170

Randomized Controlled Trial of a Low Animal Protein, High Fiber Diet in the Prevention of Recurrent Calcium Oxalate Kidney Stones  

Microsoft Academic Search

Low protein diets are commonly prescribed for patients with idiopathic calcium nephrolithiasis, who account for >80% of new diagnoses of kidney stones. This dietary advice is supported by metabolic studies and epidemiologic observational studies but has not been evaluated in a controlled trial. Using 1983-1985 data from three Northern California Kaiser Permanente Medical Centers, the authors randomly assigned 99 persons

Robert A. Hiatt; Bruce Ettinger; Bette Caan; Charles P. Quesenberry; Debra Duncan; John T. Citron

171

Supplementation with calcium salts of linoleic and trans-octadecenoic acids improves fertility of lactating dairy cows.  

PubMed

Objectives were to evaluate effects of feeding a calcium salt rich in linoleic and trans-octadecenoic acids (LTFA) on synthesis of prostaglandin F(2alpha) based on its metabolite (PGFM), uterine involution and pregnancy rates in lactating dairy cows. Five hundred and eleven Holstein cows were blocked according to parity, body condition score and milk yield in the previous lactation. Primiparous and multiparous cows were randomly assigned to one of the two treatments consisting of calcium salt (2% diet dry matter) of either palm oil (PO) or LTFA from 25 days prepartum to 80 days of lactation. Cows were time-inseminated at 70 +/- 3 days postpartum. Feeding LTFA tended (p = 0.08) to decrease the incidence of puerperal metritis (15.1% vs 8.8%). Primiparous cows supplemented with LTFA showed larger increase in plasma PGFM concentration at day 1 postpartum (17018 vs 6897 pm). Pregnancy rate after first insemination tended (p = 0.07) to be greater at 27 days after insemination (37.9% vs 28.6%), and was greater (p = 0.05) at 41 days after insemination (35.5% vs 25.8%) for cows fed LTFA compared with PO. These results indicate that unsaturated fatty acids fed in a rumen inert form have the potential to modulate reproductive events and improve pregnancy rates in lactating dairy cows. PMID:19144007

Juchem, S O; Cerri, R L A; Villaseñor, M; Galvão, K N; Bruno, R G S; Rutigliano, H M; DePeters, E J; Silvestre, F T; Thatcher, W W; Santos, J E P

2010-02-01

172

Bile acids stimulate chloride secretion through CFTR and calcium-activated Cl- channels in Calu-3 airway epithelial cells.  

PubMed

Bile acids resulting from the aspiration of gastroesophageal refluxate are often present in the lower airways of people with cystic fibrosis and other respiratory distress diseases. Surprisingly, there is little or no information on the modulation of airway epithelial ion transport by bile acids. The secretory effect of a variety of conjugated and unconjugated secondary bile acids was investigated in Calu-3 airway epithelial cells grown under an air-liquid interface and mounted in Ussing chambers. Electrogenic transepithelial ion transport was measured as short-circuit current (Isc). The taurine-conjugated secondary bile acid, taurodeoxycholic acid (TDCA), was found to be the most potent modulator of basal ion transport. Acute treatment (5 min) of Calu-3 cells with TDCA (25 ?M) on the basolateral side caused a stimulation of Isc, and removal of extracellular Cl(-) abolished this response. TDCA produced an increase in the cystic fibrosis transmembrane conductance regulator (CFTR)-dependent current that was abolished by pretreatment with the CFTR inhibitor CFTRinh172. TDCA treatment also increased Cl(-) secretion through calcium-activated chloride (CaCC) channels and increased the Na(+)/K(+) pump current. Acute treatment with TDCA resulted in a rapid cellular influx of Ca(2+) and increased cAMP levels in Calu-3 cells. Bile acid receptor-selective activation with INT-777 revealed TGR5 localized at the basolateral membrane as the receptor involved in TDCA-induced Cl(-) secretion. In summary, we demonstrate for the first time that low concentrations of bile acids can modulate Cl(-) secretion in airway epithelial cells, and this effect is dependent on both the duration and sidedness of exposure to the bile acid. PMID:24993131

Hendrick, Siobhán M; Mroz, Magdalena S; Greene, Catherine M; Keely, Stephen J; Harvey, Brian J

2014-09-01

173

Ascorbic acid spares ?-tocopherol and prevents lipid peroxidation in cultured H4IIE liver cells  

Microsoft Academic Search

Ascorbic acid, or vitamin C, can recycle a-tocopherol in lipid bilayers, but even sparing of a-tocopherol has not been a consistent finding in intact cells. Therefore, we tested the ability of ascorbate loading to spare a-tocopherol and to prevent lipid peroxidation of cultured H4IIE rat liver cells. Although a-tocopherol was undetectable in H4IIE cells, its cell content was increased by

Junjun Huang; James M. May

2003-01-01

174

Effect of feeding calcium salts of long-chain fatty acids, from palm fatty acid distillate or soybean oil, to high producing dairy cows on milk yield and composition, and on selected blood and reproductive parameters  

Microsoft Academic Search

Calcium salts of long-chain fatty acids from palm fatty acid distillate (CaPFAD) and soybean oil (CaSOFA) were compared using 14 first lactation and 26 multiparous Holstein cows housed in a free-stall barn. It was hypothesized that if replacing CaPFAD with CaSOFA, a rich source of linoleic acid, could result in increased conjugated linoleic acid (CLA) content in milk without losing

P Mandebvu; C. S Ballard; C. J Sniffen; M. P Carter; H. M Wolford; T Sato; Y Yabuuchi; E Block; D. L Palmquist

2003-01-01

175

The Effects of Dietary Calcium and Conjugated Linoleic Acid on Bone Health.  

E-print Network

??Approximately 200 million people worldwide, including 25 million in the United States, suffer from osteoporosis. The pathophysiology of osteoporosis suggests that prevention through dietary intervention… (more)

Terk, Michael

2007-01-01

176

Redox regulation of calcium signaling in cancer cells by ascorbic Acid involving the mitochondrial electron transport chain.  

PubMed

Previously, we have reported that ascorbic acid regulates calcium signaling in human larynx carcinoma HEp-2 cells. To evaluate the precise mechanism of Ca(2+) release by ascorbic acid, the effects of specific inhibitors of the electron transport chain components on mitochondrial reactive oxygen species (ROS) production and Ca(2+) mobilization in HEp-2 cells were investigated. It was revealed that the mitochondrial complex III inhibitor (antimycin A) amplifies ascorbate-induced Ca(2+) release from intracellular stores. The mitochondrial complex I inhibitor (rotenone) decreases Ca(2+) release from intracellular stores in HEp-2 cells caused by ascorbic acid and antimycin A. In the presence of rotenone, antimycin A stimulates ROS production by mitochondria. Ascorbate-induced Ca(2+) release in HEp-2 cells is shown to be unaffected by catalase. The results obtained suggest that Ca(2+) release in HEp-2 cells caused by ascorbic acid is associated with induced mitochondrial ROS production. The data obtained are in line with the concept of redox signaling that explains oxidant action by compartmentalization of ROS production and oxidant targets. PMID:23227042

Martinovich, Grigory G; Golubeva, Elena N; Martinovich, Irina V; Cherenkevich, Sergey N

2012-01-01

177

Dietary Berries and Ellagic Acid Prevent Oxidative DNA Damage and Modulate Expression of DNA Repair Genes  

PubMed Central

DNA damage is a pre-requisite for the initiation of cancer and agents that reduce this damage are useful in cancer prevention. In this study, we evaluated the ability of whole berries and berry phytochemical, ellagic acid to reduce endogenous oxidative DNA damage. Ellagic acid was selected based on >95% inhibition of 8-oxodeoxyguosine (8-oxodG) and other unidentified oxidative DNA adducts induced by 4-hydroxy-17ß-estradiol and CuCl2 in vitro. Inhibition of the latter occurred at lower concentrations (10 ?M) than that for 8-oxodG (100 ?M). In the in vivo study, female CD-1 mice (n=6) were fed either a control diet or diet supplemented with ellagic acid (400 ppm) and dehydrated berries (5% w/w) with varying ellagic acid contents – blueberry (low), strawberry (medium) and red raspberry (high), for 3 weeks. Blueberry and strawberry diets showed moderate reductions in endogenous DNA adducts (25%). However, both red raspberry and ellagic acid diets showed a significant reduction of 59% (p < 0.001) and 48% (p < 0.01), respectively. Both diets also resulted in a 3–8 fold over-expression of genes involved in DNA repair such as xeroderma pigmentosum group A complementing protein (XPA), DNA excision repair protein (ERCC5) and DNA ligase III (DNL3). These results suggest that red raspberry and ellagic acid reduce endogenous oxidative DNA damage by mechanisms which may involve increase in DNA repair. PMID:19325752

Aiyer, Harini S.; Vadhanam, Manicka V.; Stoyanova, Radka; Caprio, Gerard D.; Clapper, Margie L.; Gupta, Ramesh C.

2008-01-01

178

Effectiveness of acidic oxidative potential water in preventing bacterial infection in islet transplantation.  

PubMed

At a number of points in the current procedures of islet isolation and islet culture after the harvesting of donor pancreata, microorganisms could potentially infect the islet preparation. Furthermore, the use of islets from multiple donors can compound the risks of contamination of individual recipients. Acidic oxidative potential water (also termed electrolyzed strong acid solution, function water, or acqua oxidation water), which was developed in Japan, is a strong acid formed on the anode in the electrolysis of water containing a small amount of sodium chloride. It has these physical properties: pH, from 2.3 to 2.7; oxidative-reduction potential, from 1,000 to 1,100 mV; dissolved chlorine, from 30 to 40 ppm; and dissolved oxygen, from 10 to 30 ppm. Because of these properties, acidic oxidative potential water has strong bactericidal effects on all bacteria including methicillin-resistant Staphylococcus aureus (MRSA), viruses including HIV, HBV, HCV, CMV, and fungi as a result of the action of the active oxygen and active chlorine that it contains. We conducted this study to evaluate the effect of acidic oxidative potential water irrigation on bacterial contamination on the harvesting of porcine pancreata from slaughterhouses for islet xenotransplantation by counting the number of pancreatic surface bacteria using the Dip-slide method, and on the results of islet culture; and to evaluate the direct effect on isolated islets when it is used to prevent bacterial contamination by the static incubation test and by morphological examination. Direct irrigation of the pancreas by acidic oxidative potential water was found to be very effective in preventing bacterial contamination, but direct irrigation of isolated islets slightly decreased their viability and function. PMID:10478721

Miyamoto, M; Inoue, K; Gu, Y; Hoki, M; Haji, S; Ohyanagi, H

1999-01-01

179

Prevention by Means of Fluoride of Enamel Erosion as Caused by Soft Drinks and Orange Juice  

Microsoft Academic Search

Fluoride has been suggested to prevent erosion of the teeth, either after a topical treatment of the teeth or by addition of fluoride to the acidic drink. The main aim of the present study was to describe the dissolution of calcium fluoride in some soft drinks and orange juice and compare it with the amounts of calcium fluoride left on

M. J. Larsen

2001-01-01

180

The Marine Sponge-Derived Polyketide Endoperoxide Plakortide F Acid Mediates Its Antifungal Activity by Interfering with Calcium Homeostasis? §  

PubMed Central

Plakortide F acid (PFA), a marine-derived polyketide endoperoxide, exhibits strong inhibitory activity against the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. In the present study, transcriptional profiling coupled with mutant and biochemical analyses were conducted using the model organism Saccharomyces cerevisiae to investigate the mechanism of action of this compound. PFA elicited a transcriptome response indicative of a Ca2+ imbalance, affecting the expression of genes known to be responsive to altered cellular calcium levels. Several additional lines of evidence obtained supported a role for Ca2+ in PFA's activity. First, mutants lacking calcineurin and various Ca2+ transporters, including pumps (Pmr1 and Pmc1) and channels (Cch1 and Mid1), showed increased sensitivity to PFA. In addition, the calcineurin inhibitors FK506 and cyclosporine strongly enhanced PFA activity in wild-type cells. Furthermore, PFA activated the transcription of a lacZ reporter gene driven by the calcineurin-dependent response element. Finally, elemental analysis indicated a significant increase in intracellular calcium levels in PFA-treated cells. Collectively, our results demonstrate that PFA mediates its antifungal activity by perturbing Ca2+ homeostasis, thus representing a potentially novel mechanism distinct from that of currently used antifungal agents. PMID:21300833

Xu, Tao; Feng, Qin; Jacob, Melissa R.; Avula, Bharathi; Mask, Melanie M.; Baerson, Scott R.; Tripathi, Siddharth K.; Mohammed, Rabab; Hamann, Mark T.; Khan, Ikhlas A.; Walker, Larry A.; Clark, Alice M.; Agarwal, Ameeta K.

2011-01-01

181

Target-specific delivery of siRNA by stabilized calcium phosphate nanoparticles using dopa-hyaluronic acid conjugate.  

PubMed

Low cytotoxicity and high cellular gene delivery capability are among the most important prerequisites for the selection of a non-viral carrier. Although calcium phosphate (CAP) nanoparticles have been long used for animal cell transfection, its rapid and uncontrollable crystal growth and lack of tissue specificity are among the most challenging problems that limit its use in the clinic. In this study, we report the development of CAP nanoparticles stabilized by a conjugate of the mussel-inspired adhesive molecule, 3,4-dihydroxy-l-phenylalanine (dopa), and a nontoxic hydrophilic natural polymer, hyaluronic acid (HA), for targeted siRNA delivery to tumors. CAP/siRNA/dopa-HA can form compact nanoparticles that effectively protect siRNA from enzymatic degradation despite the structural drawbacks of siRNA, such as low charge density and short and rigid structure. In addition, stabilized CAP nanoparticles were able to maintain their colloidal stability in a physiological salt condition for over a week. The superior ability of CAP/siRNA/dopa-HA to maintain the integrity of encapsulated siRNA and the stability in solution of the nanoparticles allow this formulation to achieve improved intratumoral accumulation of siRNA and a high level of target gene silencing in solid tumors after systemic administration. Considering its biocompatibility, transfection efficacy, and tumor targeting capability, this stabilized calcium phosphate nanoparticle-based gene delivery platform should be considered a promising candidate carrier for systemic siRNA delivery and targeted cancer therapy. PMID:24995950

Lee, Min Sang; Lee, Jung Eun; Byun, Eunkyoung; Kim, Nak Won; Lee, Kyuri; Lee, Haeshin; Sim, Sang Jun; Lee, Doo Sung; Jeong, Ji Hoon

2014-10-28

182

Tests of alkaline addition to coal mine spoils for prevention of acid mine drainage  

SciTech Connect

Addition of limestone or lime products to spoil during surface mining of coal has been widely proposed in recent years, but with some apparent failures and a lack of careful documentation of successes vs. failures. This paper summarizes tests of the method at three scales. Lab tests with 1 kg samples showed that lime kiln flue dust completely prevented acid generation from shale with 7% pyritic sulfur, and limestone markedly decreased but did not prevent acid generation. At the Kauffman Mine of Al Hamilton Contracting Co. in Clearfield Co., PA, with support from PA Energy Development Authority, a mine-scale test of lime addition shows satisfactory water quality in a backfill well within the spoil. The application of a special handling procedure for the alkaline addition is believed to be a major factor in the positive results received to date. Also at this site, five test cells containing about 400 tons each of spoil with 2% pyritic sulfur had different amounts of lime added. Results to date indicate that lime addition markedly decreases AMD, but that delays in mixing lime with newly broken overburden or incomplete mixing to leave portions of spoil unlimed can allow microenvironments of acid generation to develop; the resulting AMD generation process may take some time to stop.

Rose, A.W.; Phelps, L.B.; Evans, D.R.; Parizek, R.R. [Pennsylvania State Univ., PA (United States)

1994-12-31

183

Hyaluronic acid prevents immunosuppressive drug-induced ovarian damage via up-regulating PGRMC1 expression  

PubMed Central

Chemotherapy treatment in women can frequently cause damage to the ovaries, which may lead to primary ovarian insufficiency (POI). In this study, we assessed the preventative effects of hyaluronic acid (HA) in immunosuppressive drug-induced POI-like rat models and investigated the possible mechanisms. We found that HA, which was reduced in primary and immunosuppressant-induced POI patients, could protect the immunosuppressant-induced damage to granulosa cells (GCs) in vitro. Then we found that HA blocked the tripterygium glycosides (TG) induced POI-like presentations in rats, including delayed or irregular estrous cycles, reduced 17 beta-estradiol(E2) concentration, decreased number of follicles, destruction of follicle structure, and damage of reproductive ability. Furthermore, we investigated the mechanisms of HA prevention effects on POI, which was associated with promotion of GC proliferation and PGRMC1 expression. In conclusion, HA prevents chemotherapy-induced ovarian damage by promoting PGRMC1 in GCs. This study may provide a new strategy for prevention and treatment of POI. PMID:25558795

Zhao, Guangfeng; Yan, Guijun; Cheng, Jie; Zhou, Xue; Fang, Ting; Sun, Haixiang; Hou, Yayi; Hu, Yali

2015-01-01

184

Baicalein, an active component of Scutellaria baicalensis Georgi, prevents lysophosphatidylcholine-induced cardiac injury by reducing reactive oxygen species production, calcium overload and apoptosis via MAPK pathways  

PubMed Central

Background Lysophosphatidylcholine (lysoPC), a metabolite from membrane phospholipids, accumulates in the ischemic myocardium and plays an important role in the development of myocardial dysfunction ventricular arrhythmia. In this study, we investigated if baicalein, a major component of Huang Qui, can protect against lysoPC-induced cytotoxicity in rat H9c2 embryonic cardiomyocytes. Methods Cell viability was detected by the MTT assay; ROS levels were assessed using DCFH-DA; and intracellular free calcium concentrations were assayed by spectrofluorophotometer. Cell apoptosis and necrosis were evaluated by the flow cytometry assay and Hoechst staining. Mitogen-Activated Protein Kinases (MAPKs), which included the ERK, JNK, and p38, and the apoptotic mechanisms including Bcl-2/Bax, caspase-3, caspase-9 and cytochrome c pathways were examined by Western blot analysis. The activation of MAPKs was examined by enzyme-linked immunosorbent assay. Results We found that lysoPC induced death and apoptosis of H9c2 cells in a dose-dependent manner. Baicalein could prevent lysoPC-induced cell death, production of reactive oxygen species (ROS), and increase of intracellular calcium concentration in H9c2 cardiomyoctes. In addition, baicalein also inhibited lysoPC-induced apoptosis, with associated decreased pro-apoptotic Bax protein, increased anti-apoptotic Bcl-2 protein, resulting in an increase in the Bcl-2/Bax ratio. Finally, baicalein attenuated lysoPC-induced the expression of cytochrome c, casapase-3, casapase-9, and the phosphorylations of ERK1/2, JNK, and p38. LysoPC-induced ERK1/2, JNK, and p38 activations were inhibited by baicalein. Conclusions Baicalein protects cardiomyocytes from lysoPC-induced apoptosis by reducing ROS production, inhibition of calcium overload, and deactivations of MAPK signaling pathways. PMID:25012390

2014-01-01

185

Preliminary evaluation of effects of invasive tunicate management with acetic acid and calcium hydroxide on non-target marine organisms in Prince Edward Island, Canada  

Microsoft Academic Search

The proliferation of invasive tunicates in Prince Edward Island (PEI) estuaries has necessitated the development of approaches for managing tunicates that foul aquaculture structures, especially Styela clava and Ciona intestinalis. Spraying or immersion with a saturated solution of hydrated lime (calcium hydroxide) or 5% acetic acid are effective against these tunicates, but are also biocidal to a variety of non-target

Andrea Locke; Kenneth G. Doe; Wayne L. Fairchild; Paula M. Jackman; Erica J. Reese

2009-01-01

186

Dietary inclusion of diallyl disulfide, yucca powder, calcium fumarate, an extruded linseed product, or medium-chain fatty acids does not affect methane production in lactating dairy cows  

Microsoft Academic Search

Two similar experiments were conducted to assess the effect of diallyl disulfide (DADS), yucca powder (YP), calcium fumarate (CAFU), an extruded linseed product (UNSAT), or a mixture of capric and caprylic acid (MCFA) on methane production, energy balance, and dairy cow performance. In experiment 1, a control diet (CON1) and diets supplemented with 56mg of DADS\\/kg of dry matter (DM),

S. M. van Zijderveld; J. Dijkstra; H. B. Perdok; J. R. Newbold; W. J. J. Gerrits

2011-01-01

187

Omega-3 fatty acid is a potential preventive agent for recurrent colon cancer.  

PubMed

Increasing evidence supports the contention that many malignancies, including sporadic colorectal cancer, are driven by the self-renewing, chemotherapy-resistant cancer stem/stem-like cells (CSC/CSLC), underscoring the need for improved preventive and therapeutic strategies targeting CSCs/CSLCs. Omega-3 polyunsaturated fatty acids (?-3 PUFA), have been reported to inhibit the growth of primary tumors, but their potential as a preventive agent for recurring cancers is unexplored. The primary objectives of this investigation are (i) to examine whether eicosapentaenoic acid (EPA; one of the ?-3 PUFA) synergizes with FuOx (5-FU+Oxaliplatin), the backbone of colon cancer chemotherapy, and (ii) whether EPA by itself or in combination with conventional chemotherapy prevents the recurrence of colon cancer via eliminating/suppressing CSCs/CSLCs. FuOx-resistant (chemoresistant; CR) colon cancer cells, highly enriched in CSCs, were used for this study. Although EPA alone was effective, combination of EPA and FuOx was more potent in (i) inhibiting cell growth, colonosphere formation, and sphere-forming frequency, (ii) increasing sphere disintegration, (iii) suppressing the growth of SCID mice xenografts of CR colon cancer cells, and (iv) decreasing proinflammatory metabolites in mice. In addition, EPA + FuOx caused a reduction in CSC/CSLC population. The growth reduction by this regimen is the result of increased apoptosis as evidenced by PARP cleavage. Furthermore, increased pPTEN, decreased pAkt, normalization of ?-catenin expression, localization, and transcriptional activity by EPA suggests a role for the PTEN-Akt axis and Wnt signaling in regulating this process. Our data suggest that EPA by itself or in combination with FuOx could be an effective preventive strategy for recurring colorectal cancer. PMID:25193342

Vasudevan, Anita; Yu, Yingjie; Banerjee, Sanjeev; Woods, James; Farhana, Lulu; Rajendra, Sindhu G; Patel, Aamil; Dyson, Gregory; Levi, Edi; Maddipati, Krishna Rao; Majumdar, Adhip P N; Nangia-Makker, Pratima

2014-11-01

188

Vasodilation by in vivo activation of astrocyte endfeet via two-photon calcium uncaging as a strategy to prevent brain ischemia.  

PubMed

Decreased cerebral blood flow causes brain ischemia and plays an important role in the pathophysiology of many neurodegenerative diseases, including Alzheimer's disease and vascular dementia. In this study, we photomodulated astrocytes in the live animal by a combination of two-photon calcium uncaging in the astrocyte endfoot and in vivo imaging of neurovasculature and astrocytes by intravital two-photon microscopy after labeling with cell type specific fluorescent dyes. Our study demonstrates that photomodulation at the endfoot of a single astrocyte led to a 25% increase in the diameter of a neighboring arteriole, which is a crucial factor regulating cerebral microcirculation in downstream capillaries. Two-photon uncaging in the astrocyte soma or endfoot near veins does not show the same effect on microcirculation. These experimental results suggest that infrared photomodulation on astrocyte endfeet may be a strategy to increase cerebral local microcirculation and thus prevent brain ischemia. PMID:24343443

Chen, Yuanxin; Mancuso, James; Zhao, Zhen; Li, Xuping; Cheng, Jie; Roman, Gustavo; Wong, Stephen T C

2013-12-01

189

Vasodilation by in vivo activation of astrocyte endfeet via two-photon calcium uncaging as a strategy to prevent brain ischemia  

PubMed Central

Abstract. Decreased cerebral blood flow causes brain ischemia and plays an important role in the pathophysiology of many neurodegenerative diseases, including Alzheimer’s disease and vascular dementia. In this study, we photomodulated astrocytes in the live animal by a combination of two-photon calcium uncaging in the astrocyte endfoot and in vivo imaging of neurovasculature and astrocytes by intravital two-photon microscopy after labeling with cell type specific fluorescent dyes. Our study demonstrates that photomodulation at the endfoot of a single astrocyte led to a 25% increase in the diameter of a neighboring arteriole, which is a crucial factor regulating cerebral microcirculation in downstream capillaries. Two-photon uncaging in the astrocyte soma or endfoot near veins does not show the same effect on microcirculation. These experimental results suggest that infrared photomodulation on astrocyte endfeet may be a strategy to increase cerebral local microcirculation and thus prevent brain ischemia. PMID:24343443

Chen, Yuanxin; Mancuso, James; Zhao, Zhen; Li, Xuping; Cheng, Jie; Roman, Gustavo; Wong, Stephen T. C.

2013-01-01

190

Vasodilation by in vivo activation of astrocyte endfeet via two-photon calcium uncaging as a strategy to prevent brain ischemia  

NASA Astrophysics Data System (ADS)

Decreased cerebral blood flow causes brain ischemia and plays an important role in the pathophysiology of many neurodegenerative diseases, including Alzheimer's disease and vascular dementia. In this study, we photomodulated astrocytes in the live animal by a combination of two-photon calcium uncaging in the astrocyte endfoot and in vivo imaging of neurovasculature and astrocytes by intravital two-photon microscopy after labeling with cell type specific fluorescent dyes. Our study demonstrates that photomodulation at the endfoot of a single astrocyte led to a 25% increase in the diameter of a neighboring arteriole, which is a crucial factor regulating cerebral microcirculation in downstream capillaries. Two-photon uncaging in the astrocyte soma or endfoot near veins does not show the same effect on microcirculation. These experimental results suggest that infrared photomodulation on astrocyte endfeet may be a strategy to increase cerebral local microcirculation and thus prevent brain ischemia.

Chen, Yuanxin; Mancuso, James; Zhao, Zhen; Li, Xuping; Cheng, Jie; Roman, Gustavo; Wong, Stephen T. C.

2013-12-01

191

Use of a Gluconobacter frateurii mutant to prevent dihydroxyacetone accumulation during glyceric acid production from glycerol.  

PubMed

To prevent dihydroxyacetone (DHA) by-production during glyceric acid (GA) production from glycerol using Gluconobacter frateurii, we used a G. frateurii THD32 mutant, ?sldA, in which the glycerol dehydrogenase subunit-encoding gene (sldA) was disrupted, but ?sldA grew much more slowly than the wild type, growth starting after a lag of 3 d under the same culture conditions. The addition of 1% w/v D-sorbitol to the medium improved both the growth and the GA productivity of the mutant, and ?sldA produced 89.1 g/l GA during 4 d of incubation without DHA accumulation. PMID:21071844

Habe, Hiroshi; Shimada, Yuko; Fukuoka, Tokuma; Kitamoto, Dai; Itagaki, Masayuki; Watanabe, Kunihiro; Yanagishita, Hiroshi; Yakushi, Toshiharu; Matsushita, Kazunobu; Sakaki, Keiji

2010-01-01

192

Intravenous ascorbic acid to prevent and treat cancer-associated sepsis?  

PubMed Central

The history of ascorbic acid (AA) and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS) and multi organ failure (MOF), has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once these patients develop septic symptoms, a further decrease in ascorbic acid levels occurs. Given the known role of ascorbate in: a) maintaining endothelial and suppression of inflammatory markers; b) protection from sepsis in animal models; and c) direct antineoplastic effects, we propose the use of ascorbate as an adjuvant to existing modalities in the treatment and prevention of cancer-associated sepsis. PMID:21375761

2011-01-01

193

Chlorogenic acid prevents isoproterenol-induced hypertrophy in neonatal rat myocytes.  

PubMed

Cardiac hypertrophy is an independent risk factor for cardiovascular disease and its subsequent progression to heart failure represents a major cause of morbidity and mortality in the world. CGA is an important component of Chinese herbal medicine, acting as an antioxidant, scavenging free radicals and preventing inflammation. This study found that with the pre-treatment of chlorogenic acid in Iso-induced neonatal rat myocytes, the levels of the hypertrophic markers, ANP, BNP and ?-MHC decreased. The nuclear translocation of NF-?B was blocked, whereas NF-?BIA, an inhibitor of NF-?B, was upregulated accordingly. And the level of the intracellular ROS was also reduced. These data reveal that chlorogenic acid may inhibit Iso-induced cardiac hypertrophy by attenuating NF-?B signaling pathway and suppressing ROS. PMID:24583048

Li, Yanfei; Shen, Dan; Tang, Xiaomei; Li, Xin; Wo, Da; Yan, Hongwei; Song, Rui; Feng, Jian; Li, Ping; Zhang, Jie; Li, Jue

2014-05-01

194

THE POTENTIAL ROLE OF DIETARY OMEGA 3 FATTY ACIDS IN THE PREVENTION OF DEMENTIA AND MACULAR DEGENERATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dementia and AMD are major causes of disability in the elderly. Omega-3 fatty acids, particularly docosahexaenoic acid (DHA) are highly concentrated in brain and retinal tissue and have been implicated in the prevention or delay in progression of dementia and age-related macular degeneration (AMD). ...

195

Effect of Acidic Environment on the Push-Out Bond Strength of Calcium-Enriched Mixture Cement  

PubMed Central

Introduction: This laboratory study was performed to evaluate the effect of different acidic pH values on the push-out bond strength of calcium-enriched mixture (CEM) cement. Methods and Materials: Forty-eight root dentin slices were obtained from freshly extracted single rooted human teeth and their lumen were instrumented to achieve a diameter of 1.3 mm. Then, CEM cement was mixed according to manufacturers’ instruction and placed in the lumens with minimal pressure. The specimens were randomly divided into four groups (n=12) which were wrapped in pieces of gauze soaked in either synthetic tissue fluid (STF) (pH=7.4) or butyric acid which was buffered at pH values of 4.4, 5.4 and 6.4. They were then incubated for 4 days at 37°C. The push-out test was performed by means of the universal testing machine. Specimens were then examined under a digital light microscope at 20× magnification to determine the nature of the bond failure. The data were analyzed using the Kruskal-Wallis test followed by Dunn’s test for pairwise comparisons. Results: The highest push-out bond strength (10.19±4.39) was seen in the pH level of 6.4, which was significantly different from the other groups (P<0.05). The values decreased to 2.42±2.25 MPa after exposure to pH value of 4.4. Conclusion: Lower pH value of highly acidic environments (pH=4.4), adversely affects the force needed for displacement of CEM cement; while in higher pH values (pH=6.4) the bond-strength was not affected. CEM cement is recommended in clinical situations where exposure to acidic environment is unavoidable. PMID:25386207

Sobhnamayan, Fereshte; Sahebi, Safoora; Naderi, Misagh; Shojaee, Nooshin Sadat; Shanbezadeh, Najmeh

2014-01-01

196

The Effect of Acidic pH on Microleakage of Mineral Trioxide Aggregate and Calcium-Enriched Mixture Apical Plugs  

PubMed Central

Introduction: The purpose of this laboratory study was to evaluate the effect of acidic pH on the sealing ability of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA) apical plugs. Methods and Materials: Seventy single-rooted human maxillary anterior teeth were recruited. The teeth were randomly divided into 4 experimental groups (n=15), and 1 negative and 1 positive control groups of 5. The root canals were cleaned and shaped and the terminal 3 mm of the roots were resected. Then MTA and CEM cement plugs were condensed in apical region with 3 mm thicknesses. The samples were exposed to pH values of 5.5 and 7.4. Leakage was evaluated by the fluid filtration technique at 1, 7, 14, 30 day intervals. Data were analyzed by the repeated measures MANOVA, one-way ANOVA and MANOVA/Bonferroni test. Results: Acidic pH significantly reduced the sealing ability of MTA after 1, 14 and 30 days (P<0.05). The rate of microleakage in CEM cement samples in acidic pH was significantly greater than that in neutral pH in day 30 (P<0.05). There was no significant difference between the sealing property of MTA and CEM cement at both pH levels (P>0.05). Conclusion: It can be concluded that the CEM cement exhibited similar sealing ability as MTA at both pH levels. In addition, an acidic pH environment reduced the sealing ability of MTA and CEM cement after 30 days. PMID:25386205

Mirhadi, Hossein; Moazzami, Fariborz; Safarzade, Sareh

2014-01-01

197

Effects of Benzoic Acid and Dietary Calcium:Phosphorus Ratio on Performance and Mineral Metabolism of Weanling Pigs  

PubMed Central

In a 2×2 factorial experiment the hypotheses tested were that the metabolic acid load caused by benzoic acid (BA) added to the feed affects bone mineralization of weanling pigs, and that a wide dietary calcium (Ca) to phosphorus (P) ratio in phytase-supplemented feeds with a marginal P concentration has a positive effect on bone mineralization. The four experimental diets, which contained 0.4% P and were supplemented with 1,000 FTU phytase/kg, contained either 5 g BA/kg or no BA and either 0.77% Ca or 0.57% Ca. The 68 four-week-old Large White pigs were fed the experimental diets ad libitum for six weeks and were then slaughtered. Benzoic acid increased feed intake (p = 0.009) and growth rate (p = 0.051), but did not influence the feed conversion ratio (p>0.10). Benzoic acid decreased the pH of the urine (p = 0.031), but did not affect breaking strength and mineralization of the tibia (p>0.10). The wide Ca:P ratio decreased feed intake (p = 0.034) and growth rate (p = 0.007) and impaired feed the conversion ratio (p = 0.027), but increased the mineral concentration in the fat-free DM of the tibia (p = 0.013) without influencing its breaking strength (p>0.10). The observed positive effect of the wide Ca:P ratio on bone mineralization may be attributed, at least in part, to the impaired feed conversion ratio, i.e. to the higher feed intake and consequently to the higher mineral intake per kg BW gain. The negative impact on animal performance of the wide dietary Ca:P ratio outweighs its potentially positive effect on bone mineralization, precluding its implementation under practical feeding conditions. PMID:25049984

Gutzwiller, A.; Schlegel, P.; Guggisberg, D.; Stoll, P.

2014-01-01

198

Effects of calcium on seed germination, seedling growth and photosynthesis of six forest tree species under simulated acid rain.  

PubMed

We selected six tree species, Pinus massoniana Lamb., Cryptomeria fortunei Hooibr. ex Otto et Dietr., Cunninghamia lanceolata (Lamb.) Hook., Liquidambar formosana Hance, Pinus armandii Franch. and Castanopsis chinensis Hance, which are widely distributed as dominant species in the forest of southern China where acid deposition is becoming more and more serious in recent years. We investigated the effects and potential interactions between simulated acid rain (SiAR) and three calcium (Ca) levels on seed germination, radicle length, seedling growth, chlorophyll content, photosynthesis and Ca content in leaves of these six species. We found that the six species showed different responses to SiAR and different Ca levels. Pinus armandii and C. chinensis were very tolerant to SiAR, whereas the others were more sensitive. The results of significant SiAR?×?Ca interactions on different physiological parameters of the six species demonstrate that additional Ca had a dramatic rescue effect on the seed germination and seedling growth for the sensitive species under SiAR. Altogether, we conclude that the negative effects of SiAR on seed germination, seedling growth and photosynthesis of the four sensitive species could be ameliorated by Ca addition. In contrast, the physiological processes of the two tolerant species were much less affected by both SiAR and Ca treatments. This conclusion implies that the degree of forest decline caused by long-term acid deposition may be attributed not only to the sensitivity of tree species to acid deposition, but also to the Ca level in the soil. PMID:21470980

Liu, Ting-Wu; Wu, Fei-Hua; Wang, Wen-Hua; Chen, Juan; Li, Zhen-Ji; Dong, Xue-Jun; Patton, Janet; Pei, Zhen-Ming; Zheng, Hai-Lei

2011-04-01

199

[Topical Application of Tranexamic Acid to Prevent Post-tonsillectomy Haemorrhage.  

PubMed

Topical Application of Tranexamic Acid to Prevent Post-tonsillectomy Haemorrhage Background: Haemorrhage after tonsillectomy (TE) is a frequent and possibly major complication. The aim of the present study was to examine, if the rate of haemorrhage after tonsillectomy could be reduced by the topical application of Tranexamic acid (TXA) postoperatively. Material and Methods: Between November 2011 and April 2013, all patients (n=246) received TXA postoperatively to prevent haemorrhage after TE. The patients were instructed to dilute 1 ampulla of TXA in 300?ml of tap water (concentration 0.2%) from postoperative day 5-10 and to gargle or spray the tonsillar fossae 5-6 times daily. The study group was compared retrospectively with a control group of patients undergoing TE with-out postoperative application of TXA from December 2010 to November 2011 (n=248). Results: The overall rate of postoperative haemorrhage was 19% and 22% in the study and control group, respectively. The rate of postoperative bleeding that needed surgical intervention was at 8.9% and 11.3% in the study and control group, respectively. Topical application of TXA did not significantly reduce the rate of postoperative haemorrhage after TE. Conclusion: Topically applied TXA did not reduce postoperative haemorrhage after TE. However, a slight tendency to less bleeding which needed surgical intervention was found in pa-tients older than ??12 years. PMID:24967824

Hinder, D; Tschopp, K

2014-06-26

200

Reducing cannabinoid abuse and preventing relapse by enhancing endogenous brain levels of kynurenic acid  

PubMed Central

In the reward circuitry of the brain, alpha-7-nicotinic acetylcholine receptors (?7nAChRs) modulate effects of delta-9-tetrahydrocannabinol (THC), marijuana’s main psychoactive ingredient. Kynurenic acid (KYNA) is an endogenous negative allosteric modulator of ?7nAChRs. Here we report that the kynurenine 3-monooxygenase (KMO) inhibitor Ro 61-8048 increases brain KYNA levels and attenuates cannabinoid-induced increases in extracellular dopamine in reward-related brain areas. In the self-administration model of drug abuse, Ro 61-8048 reduced the rewarding effects of THC and the synthetic cannabinoid WIN 55,212-2 in squirrel monkeys and rats, respectively, and it also prevented relapse to drug-seeking induced by re-exposure to cannabinoids or cannabinoid-associated cues. The effects of enhancing endogenous KYNA levels with Ro 61-8048 were prevented by positive allosteric modulators of ?7nAChRs. Despite a clear need, there are currently no medications approved for treatment of marijuana dependence. Modulation of KYNA provides a novel pharmacological strategy for achieving abstinence from marijuana and preventing relapse. PMID:24121737

Justinova, Zuzana; Mascia, Paola; Wu, Hui-Qiu; Secci, Maria E.; Redhi, Godfrey H.; Panlilio, Leigh V.; Scherma, Maria; Barnes, Chanel; Parashos, Alexandra; Zara, Tamara; Fratta, Walter; Solinas, Marcello; Pistis, Marco; Bergman, Jack; Kangas, Brian D.; Ferré, Sergi; Tanda, Gianluigi; Schwarcz, Robert; Goldberg, Steven R.

2013-01-01

201

Gluconic acid-producing Pseudomonas sp. prevent ?-actinorhodin biosynthesis by Streptomyces coelicolor A3(2).  

PubMed

Streptomyces are ubiquitous soil bacteria well known for their ability to produce a wide range of secondary metabolites including antibiotics. In their natural environments, they co-exist and interact with complex microbial communities and their natural products are assumed to play a major role in mediating these interactions. Reciprocally, their secondary metabolism can be influenced by the surrounding microbial communities. Little is known about these complex interactions and the underlying molecular mechanisms. During pairwise co-culture experiments, a fluorescent Pseudomonas, Pseudomonas fluorescens BBc6R8, was shown to prevent the production of the diffusible blue pigment antibiotic ?-actinorhodin by Streptomyces coelicolor A3(2) M145 without altering the biosynthesis of the intracellular actinorhodin. A mutant of the BBc6R8 strain defective in the production of gluconic acid from glucose and consequently unable to acidify the culture medium did not show any effect on the ?-actinorhodin biosynthesis in contrast to the wild-type strain and the mutant complemented with the wild-type allele. In addition, when glucose was substituted by mannitol in the culture medium, P. fluorescens BBc6R8 was unable to acidify the medium and to prevent the biosynthesis of the antibiotic. All together, the results show that P. fluorescens BBc6R8 impairs the biosynthesis of the lactone form of actinorhodin in S. coelicolor by acidifying the medium through the production of gluconic acid. Other fluorescent Pseudomonas and the opportunistic pathogen Pseudomonas aeruginosa PAO1 also prevented the ?-actinorhodin production in a similar way. We propose some hypotheses on the ecological significance of such interaction. PMID:24906569

Galet, Justine; Deveau, Aurélie; Hôtel, Laurence; Leblond, Pierre; Frey-Klett, Pascale; Aigle, Bertrand

2014-09-01

202

The effect of casein phosphopeptide-amorphous calcium phosphate paste and sodium fluoride mouthwash on the prevention of dentine erosion: An in vitro study  

PubMed Central

Aim: The purpose was to compare the effect of 0.2% sodium fluoride mouthwash and casein phosphopeptide-amorphous calcium phosphate paste on prevention of dentin erosion. Materials and Methods: Buccal surfaces of 36 sound premolar teeth were ground flat and polished with abrasive discs. Half the polished surfaces were covered with tape to maintain a reference surface. Samples were randomly allocated into three groups. Group A was pretreated with tooth mousse (TM) 4 times a day for 5 days. Group B was pretreated with 0.2% sodium fluoride mouthwash 4 times a day for 5 days. Group C was considered as the control group with no pretreatment. In the next step, the samples were exposed to Coca-Cola 4 times a day for 3 days. After each erosive cycle, the samples were rinsed with deionized water and stored in artificial saliva. The surface loss was determined using profilometry. Results: The erosion in both Groups A and B was less than the control group. The surface loss in mouthwash group was significantly lower than in the control group. Erosion in TM group was more than the mouthwash group and less than the control group. Conclusion: Sodium fluoride mouthwash is more effective for prevention of dentin erosion. PMID:24944448

Moezizadeh, Maryam; Alimi, Azar

2014-01-01

203

Effects of the N/L-type calcium channel blocker cilnidipine on nephropathy and uric acid metabolism in hypertensive patients with chronic kidney disease (J-CIRCLE study).  

PubMed

This study assessed the urinary albumin/creatinine ratio (ACR) and uric acid metabolism in 70 hypertensive patients with chronic kidney disease in whom urinary ACR had remained ?30 mg/g under the treatment of the L-type calcium channel blocker amlodipine. Three months after switching to the N/L-type calcium channel blocker cilnidipine, blood pressure (BP) did not change; however, urinary ACR significantly decreased with cilnidipine. Serum uric acid levels showed no significant change. In cases where uric acid production had been high (urinary uric acid/creatinine ratio ?0.5), the urinary uric acid/creatinine ratio decreased significantly after cilnidipine treatment, suggesting that cilnidipine can suppress excessive uric acid formation. These results suggest that switching from amlodipine to cilnidipine results in a significant reduction in urinary ACR as well as significant reduction in uric acid production. Thus, cilnidipine is more useful than amlodipine in improving albuminuria and uric acid metabolism in hypertensive patients with chronic kidney disease. PMID:25264215

Uchida, Shunya; Takahashi, Masato; Sugawara, Masahiro; Saito, Tomoaki; Nakai, Kazuhiko; Fujita, Masami; Mochizuki, Koichi; Shin, Isu; Morita, Takashi; Hikita, Tomoyuki; Itakura, Hironao; Takahashi, Yuko; Mizuno, Shigeki; Ohno, Yasumi; Ito, Kageki; Ito, Takafumi; Soma, Masayoshi

2014-10-01

204

Influence of citric acid as chemical modifier for lead determination in dietary calcium supplement samples by graphite furnace atomic absorption spectrometry  

NASA Astrophysics Data System (ADS)

Citric acid was used as a chemical modifier for Pb determination by graphite furnace atomic absorption spectrometry in dietary supplement samples (calcium carbonate, dolomite and oyster shell samples) and its efficiency was compared to the use of palladium. Pyrolysis and atomization curves were established without use of chemical modifier, with the addition of 20, 100 and 200 ?g of citric acid, and with 3 ?g of palladium. The citric acid modifier made possible the interference-free Pb determination in the presence of high concentrations of Ca and Mg nitrates. Acid sample digestion involving closed vessels (microwave-assisted and conventional heating) and acid attack using polypropylene vessels at room temperature were compared. All digestion procedures presented similar results for calcium carbonate and dolomite samples. However, for oyster shell samples accurate results were obtained only with the use of closed vessel systems. Analyte addition and matrix-matched standards were used for calibration. The characteristic mass for Pb using citric acid and palladium were 16 and 25 pg, respectively. The relative standard deviation (RSD) was always less than 5% when citric acid was used. The relative and absolute limits of detection were 0.02 ?g g - 1 and 8 pg with citric acid and 0.1 ?g g - 1 and 44 pg with the Pd modifier, respectively ( n = 10, 3?). The recovery of Pb in spiked calcium supplement samples (10 ?g l - 1 ) was between 98% and 105%. With the use of 100 ?g of citric acid as chemical modifier, problems such as high background absorption and high RSD values were minimized in comparison to the addition of 3 ?g of palladium.

Cezar Paz de Mattos, Julio; Medeiros Nunes, Adriane; Figueiredo Martins, Ayrton; Luiz Dressler, Valderi; Marlon de Moraes Flores, Érico

2005-06-01

205

The effects of acid treatment and calcium ions on the solubility of concanavalin A  

NASA Technical Reports Server (NTRS)

The effects of acid treatment (which removes Mn and Ca ions) and Ca(2+) ions on the solubility of jack-bean-meal concanavalin A were investigated using two techniques: the sitting drop technique and the microcolumn technique. It was found that the solubility of concanavalin A varied with the protein preparation procedures and with measurement techniques. Addition of Ca(2+) resulted in greatly lowered solubilities compared with the acid treated protein. The sitting drop solubilities for the recalcified protein agreed better with those reported by Mikol and Giege (1989) than with solubilities determined from column data.

Cacioppo, Elizabeth; Pusey, Marc L.

1992-01-01

206

Electrochemical splitting of calcium carbonate to increase solution alkalinity: implications for mitigation of carbon dioxide and ocean acidity.  

PubMed

Electrochemical splitting of calcium carbonate (e.g., as contained in limestone or other minerals) is explored as a means of forming dissolve hydroxides for absorbing, neutralizing, and storing carbon dioxide, and for restoring, preserving, or enhancing ocean calcification. While essentially insoluble in water, CaCO3 can be dissolved in the presence of the highly acidic anolyte of a water electrolysis cell. The resulting charged constituents, Ca2+ and C03(2-), migrate to the cathode and anode, respectively, forming Ca(OH)2 on the one hand and H2CO3 (or H2O and CO2) on the other. By maintaining a pH between 6 and 9, subsequent hydroxide reactions with CO2 primarily produce dissolved calcium bicarbonate, Ca(HCO3)2aq. Thus, for each mole of CaCO3 split there can be a net capture of up to 1 mol of CO2. Ca(HCO3)2aq is thus the carbon sequestrant that can be diluted and stored in the ocean, in natural or artificial surface water reservoirs, or underground. The theoretical work requirement for the reaction is 266 kJe per net mole CO2 consumed. Even with inefficiencies, a realized net energy expenditure lower than the preceding quantity appears possible considering energy recovery via oxidation of the H2 produced. The net process cost is estimated to be <$100/tonne CO2 mitigated. An experimental demonstration of the concept is presented, and further implementation issues are discussed. PMID:19192821

Rau, Greg H

2008-12-01

207

Bioefficacy of a novel calcium–potassium salt of (?)-hydroxycitric acid  

Microsoft Academic Search

Obesity is associated with cardiovascular disease, diabetes and certain forms of cancer. Popular strategies on weight loss often fail to address many key factors such as fat mass, muscle density, bone density, water mass, their inter-relationships and impact on energy production, body composition, and overall health and well-being. (?)-Hydroxycitric acid (HCA), a natural plant extract from the dried fruit rind

Bernard W. Downs; Manashi Bagchi; Gottumukkala V. Subbaraju; Michael A. Shara; Harry G. Preuss; Debasis Bagchi

2005-01-01

208

Comparison of Calcium Salts and Formaldehyde-Protected Conjugated Linoleic Acid in Inducing Milk Fat Depression  

Microsoft Academic Search

Abomasal infusion studies have shown that trans-10, cis-12 conjugated linoleic acid (CLA) decreases milk fat synthesis. However, supplements of CLA must avoid rumen biohydrogenation for this technology to be ap- plied to ruminants. Rumen protection methods would reduce CLA metabolism in the rumen and increase its supply to the small intestine. Our objective was to com- pare the efficacy of

M. J. de Veth; S. K. Gulati; N. D. Luchini; D. E. Bauman

2005-01-01

209

ALUMINUM SOLUBILITY, CALCIUM-ALUMINUM EXCHANGE, AND PH IN ACID FOREST SOILS  

EPA Science Inventory

Important components in several models designed to describe the effects of acid deposition on soils and surface waters are the pH-A1 and Ca-A1 exchange relationships. f A1 solubility is controlled by A1 trihydroxide minerals, the theoretical pH-A1 relationship can be described by...

210

Lead and calcium binding to fulvic acids: Salt effect and competition  

SciTech Connect

Knowledge of the speciation of Pb in natural aquatic systems is important if the authors want to understand the bioavailability and mobility of Pb in polluted and natural environments. The results given in this paper were obtained under conditions as close as possible to natural conditions. These new data show that Pb strongly binds to fulvic acids. The authors also show that the competitive effect of Pb on Ca binding to the same fulvic acid is smaller than the salt effect on Ca binding to fulvic acids as pH varies from 4 to 8. All the data were analyzed with the NICCA-Donnan model developed to describe metal ion binding to natural organic matter. The model predictions of competitive and salt effects are excellent. Comparison of their results with previously published data suggests that metal ion binding strength is similar for fulvic acids from different origins. Thus, all data sets could be interpreted within the framework of a unified modeling approach.

Pinheiro, J.P.; Mota, A.M.; Benedetti, M.F.

1999-10-01

211

Safety assessment of (?)-hydroxycitric acid and Super CitriMax ®, a novel calcium\\/potassium salt  

Microsoft Academic Search

(?)-Hydroxycitric acid (HCA) is a principle constituent (10–30%) of the dried fruit rind of Garcinia cambogia, a plant native to Southeastern Asia. The dried rind has been used for centuries throughout Southeast Asia as a food preservative, flavoring agent and carminative. Extensive experimental studies show that HCA inhibits fat synthesis and reduces food intake. The objective of this review is

M. G. Soni; G. A. Burdock; H. G. Preuss; S. J. Stohs; S. E. Ohia; D. Bagchi

2004-01-01

212

Soil calcium status and the response of stream chemistry to changing acidic deposition rates  

USGS Publications Warehouse

Despite a decreasing trend in acidic deposition rates over the past two to three decades, acidified surface waters in the northeastern United States have shown minimal changes. Depletion of soil Ca pools has been suggested as a cause, although changes in soil Ca pools have not been directly related to long-term records of stream chemistry. To investigate this problem, a comprehensive watershed study was conducted in the Neversink River Basin, in the Catskill Mountains of New York, during 1991-1996. Spatial variations of atmospheric deposition, soil chemistry, and stream chemistry were evaluated over an elevation range of 817-1234 m to determine whether these factors exhibited elevational patterns. An increase in atmospheric deposition of SO4 with increasing elevation corresponded with upslope decreases of exchangeable soil base concentrations and acid-neutralizing capacity of stream water. Exchangeable base concentrations in homogeneous soil incubated within the soil profile for one year also decreased with increasing elevation. An elevational gradient in precipitation was not observed, and effects of a temperature gradient on soil properties were not detected. Laboratory leaching experiments with soils from this watershed showed that (1) concentrations of Ca in leachate increased as the concentrations of acid anions in added solution increased, and (2) the slope of this relationship was positively correlated with base saturation. Field and laboratory soil analyses are consistent with the interpretation that decreasing trends in acid-neutralizing capacity in stream water in the Neversink Basin, dating back to 1984, are the result of decreases in soil base saturation caused by acidic deposition.

Lawrence, G.B.; David, M.B.; Lovett, G.M.; Murdoch, P.S.; Burns, D.A.; Stoddard, J.L.; Baldigo, B.P.; Porter, J.H.; Thompson, A.W.

1999-01-01

213

Calcium supplements  

MedlinePLUS

... The two main forms of calcium pills are: Calcium carbonate: Over-the-counter antacid products, such as Tums and Rolaids contain calcium carbonate. These sources of calcium carbonate do not cost ...

214

[Calcium-dependent signaling of acid secretion in isolated parietal cells from guinea pigs and its modification by ethanol].  

PubMed

Treatment of isolated parietal cells from guinea pig gastric mucosa with ethanol caused a rapid increase in [Ca2+]i and concomitant decrease in the capacity for carbachol-stimulated acid secretion in a dose dependent manner. Carbachol rapidly increased the [Ca2+]i from trimethoxybenzoic acid 8-(diethylamino)-octyl ester sensitive intracellular pool. In contrast, the increase with ethanol was through La3+ sensitive Ca2+ channel from external source, which suppressed the Ca2+ response subsequently stimulated with carbachol. Pretreatment of the cells with EGTA or La3+ completely prevented the elevation of [Ca2+]i with ethanol and preserved the Ca2+ response to carbachol. These findings indicate that ethanol-induced elevation of [Ca2+]i may desensitize the stimulation of carbachol. Furthermore, treatment of the parietal cells with ethanol increased the activity of protein kinase C in both cytosolic and membrane fractions of the cells. Activation of protein kinase C with phorbol diester suppressed the capacity for acid secretion. These results suggest that ethanol may inhibit the carbachol-stimulated acid secretion through the desensitization of Ca2+ response and the activation of protein kinase C. PMID:1404976

Niki, S; Rokutan, K; Nakamura, K; Ogihara, S; Kutsumi, H; Saitoh, T; Aoike, A; Kawai, K

1992-08-01

215

Free fatty acid induced impairment of insulin signaling is prevented by the diastereomeric mixture of calophyllic acid and isocalophyllic acid in skeletal muscle cells.  

PubMed

Elevated fatty acid levels play a pathogenic role in the development of insulin resistance, associated with type 2 diabetes. Interventions with ability to ameliorate fatty acid-induced insulin resistance might be useful for the management of diabetes. Here, we explored the effect of the diastereomeric mixture of calophyllic acid and isocalophyllic acid (F015) on palmitate-induced insulin resistance in skeletal muscle cells. An incubation of L6 myotubes with palmitate inhibited insulin-stimulated glucose uptake and translocation of GLUT4 to cell surface. Addition of F015 strongly prevented these inhibitions. Furthermore, F015 effectively inhibited the ability of palmitate to reduce insulin-stimulated phosphorylation of IRS-1, AKT and GSK-3? in L6 myotubes. F015 presented a strong inhibition on palmitate-induced production of reactive oxygen species and associated inflammation, as the activation JNK, ERK1/2 and p38 MAPK were greatly reduced. F015 also inhibited inflammation-stimulated IRS-1 serine phosphorylation and restored insulin-stimulated IRS-1 tyrosine phosphorylation in presence of palmitate, resulted in enhanced insulin sensitivity. Results suggest that F015 inhibits palmitate-induced, reactive oxygen species-associated MAPK kinase activation and restored insulin sensitivity through regulating IRS-1 function. All these indicate F015 to be a potentially therapeutic candidate for insulin resistance and type 2 diabetes. PMID:25445050

Jaiswal, Natasha; Gunaganti, Naresh; Maurya, Chandan Kumar; Narender, Tadigoppula; Tamrakar, Akhilesh Kumar

2015-01-01

216

Regulation of transmural transport of amino acid/metal conjugates by dietary calcium in crustacean digestive tract.  

PubMed

Effects of luminal Ca(2+) and Mn(2+) on transmural mucosal to serosal (MS) transport of (3) H-L-leucine were characterized in the isolated and perfused intestine of the American lobster, Homarus americanus. (3) H-L-leucine MS transport in the presence of 20 µM Mn(2+) was a sigmoidal function of luminal amino acid concentration, following the Hill equation for multisite cooperative, carrier-mediated, transport. Luminal Ca(2+) was a non-competitive inhibitor of Mn(2+) -stimulated (3) H-L-leucine MS flux. Amino acid transport was hyperbolically stimulated by luminal Ca(2+) or Mn(2+). During 20 µM Mn(2+) -stimulation of (3) H-L-leucine MS flux, addition of 25 mM Ca(2+) strongly reduced amino acid transport Jmax , without affecting amino acid binding properties. Hyperbolic luminal Mn(2+) stimulation of 20 µM (3) H-L-leucine MS flux was also strongly inhibited by 25 mM luminal Ca(2+) , significantly reducing 20 µM (3) H-L-leucine Jmax . Increasing the luminal concentration of verapamil, a calcium channel blocker, significantly increased MS transport of 20 µM (3) H-L-leucine in the presence of 100 nM Mn(2+) by reducing diffusional Ca(2+) uptake into intestinal epithelial cells through verapamil-sensitive channels. A model is proposed supporting the concept of molecular mimicry, whereby (3) H-L-leucine enters lobster intestinal epithelial cells by one or more amino acid-specific transporters and by a dipeptide-like transporter that is capable of binding and transporting peptide molecular mimics (bis-complexes) between Ca(2+) or Mn(2+) and (3) H-L-leucine using the membrane potential as a major driving force for the transport event. According to the model, Ca(2+) entry through apical Ca(2+) channels regulates the magnitude of the membrane potential and therefore the size of the driving force for bis-complex uptake. PMID:24254522

Abdel-Malak, Rania; Ahearn, Gregory A

2014-03-01

217

Influence of fluoride, sulfate and acidity on extractable phosphorus, calcium, magnesium and potassium  

Microsoft Academic Search

In an attempt to develop an improved extractant for the soil test evaluation of plant available nutrients the influence of fluoride, sulfate and acidity on extractable P and Ca was investigated with 12 taxonomically different soils, (sequentially fractionated for Ca, Al, and Fe forms of phosphorus). The soils were extracted with 0.025, 0.05, 0.075 and 0.1N HCl alone and in

A. Mehlich

1978-01-01

218

Nanouric acid or nanocalcium phosphate as central nidus to induce calcium oxalate stone formation: a high-resolution transmission electron microscopy study on urinary nanocrystallites  

PubMed Central

Purpose This study aimed to accurately analyze the relationship between calcium oxalate (CaOx) stone formation and the components of urinary nanocrystallites. Method High-resolution transmission electron microscopy (HRTEM), selected area electron diffraction, fast Fourier transformation of HRTEM, and energy dispersive X-ray spectroscopy were performed to analyze the components of these nanocrystallites. Results The main components of CaOx stones are calcium oxalate monohydrate and a small amount of dehydrate, while those of urinary nanocrystallites are calcium oxalate monohydrate, uric acid, and calcium phosphate. The mechanism of formation of CaOx stones was discussed based on the components of urinary nanocrystallites. Conclusion The formation of CaOx stones is closely related both to the properties of urinary nanocrystallites and to the urinary components. The combination of HRTEM, fast Fourier transformation, selected area electron diffraction, and energy dispersive X-ray spectroscopy could be accurately performed to analyze the components of single urinary nanocrystallites. This result provides evidence for nanouric acid and/or nanocalcium phosphate crystallites as the central nidus to induce CaOx stone formation. PMID:25258530

Gao, Jie; Xue, Jun-Fa; Xu, Meng; Gui, Bao-Song; Wang, Feng-Xin; Ouyang, Jian-Ming

2014-01-01

219

Exercise training delays cardiac dysfunction and prevents calcium handling abnormalities in sympathetic hyperactivity-induced heart failure mice.  

PubMed

Exercise training (ET) is a coadjuvant therapy in preventive cardiology. It delays cardiac dysfunction and exercise intolerance in heart failure (HF); however, the molecular mechanisms underlying its cardioprotection are poorly understood. We tested the hypothesis that ET would prevent Ca(2+) handling abnormalities and ventricular dysfunction in sympathetic hyperactivity-induced HF mice. A cohort of male wild-type (WT) and congenic alpha(2A)/alpha(2C)-adrenoceptor knockout (alpha(2A)/alpha(2C)ARKO) mice with C57BL6/J genetic background (3-5 mo of age) were randomly assigned into untrained and exercise-trained groups. ET consisted of 8-wk swimming session, 60 min, 5 days/wk. Fractional shortening (FS) was assessed by two-dimensional guided M-mode echocardiography. The protein expression of ryanodine receptor (RyR), phospho-Ser(2809)-RyR, sarcoplasmic reticulum Ca(2+) ATPase (SERCA2), Na(+)/Ca(2+) exchanger (NCX), phospholamban (PLN), phospho-Ser(16)-PLN, and phospho-Thr(17)-PLN were analyzed by Western blotting. At 3 mo of age, no significant difference in FS and exercise tolerance was observed between WT and alpha(2A)/alpha(2C)ARKO mice. At 5 mo, when cardiac dysfunction is associated with lung edema and increased plasma norepinephrine levels, alpha(2A)/alpha(2C)ARKO mice presented reduced FS paralleled by decreased SERCA2 (26%) and NCX (34%). Conversely, alpha(2A)/alpha(2C)ARKO mice displayed increased phospho-Ser(16)-PLN (76%) and phospho-Ser(2809)-RyR (49%). ET in alpha(2A)/alpha(2C)ARKO mice prevented exercise intolerance, ventricular dysfunction, and decreased plasma norepinephrine. ET significantly increased the expression of SERCA2 (58%) and phospho-Ser(16)-PLN (30%) while it restored the expression of phospho-Ser(2809)-RyR to WT levels. Collectively, we provide evidence that improved net balance of Ca(2+) handling proteins paralleled by a decreased sympathetic activity on ET are, at least in part, compensatory mechanisms against deteriorating ventricular function in HF. PMID:17975126

Medeiros, Alessandra; Rolim, Natale P L; Oliveira, Rodrigo S F; Rosa, Kaleizu T; Mattos, Katt C; Casarini, Dulce E; Irigoyen, Maria Claúdia; Krieger, Eduardo M; Krieger, José Eduardo; Negrão, Carlos Eduardo; Brum, Patricia C

2008-01-01

220

European Stroke Prevention Study 2. Dipyridamole and acetylsalicylic acid in the secondary prevention of stroke 1 1 ESPS-2 Writing Committee  

Microsoft Academic Search

In 1988, we undertook a randomized, placebo-controlled, double-blind trial to investigate the safety and efficacy of low-dose acetylsalicylic acid (ASA), modified-release dipyridamole, and the two agents in combination for secondary prevention of ischemic stroke. Patients with prior stroke or transient ischemic attack (TIA) were randomized to treatment with ASA alone (50 mg daily), modified-release dipyridamole alone (400 mg daily), the

H. C. Diener; L. Cunha; C. Forbes; J. Sivenius; P. Smets; A. Lowenthal

1996-01-01

221

Acacetin Inhibits Glutamate Release and Prevents Kainic Acid-Induced Neurotoxicity in Rats  

PubMed Central

An excessive release of glutamate is considered to be a molecular mechanism associated with several neurological diseases that causes neuronal damage. Therefore, searching for compounds that reduce glutamate neurotoxicity is necessary. In this study, the possibility that the natural flavone acacetin derived from the traditional Chinese medicine Clerodendrum inerme (L.) Gaertn is a neuroprotective agent was investigated. The effect of acacetin on endogenous glutamate release in rat hippocampal nerve terminals (synaptosomes) was also investigated. The results indicated that acacetin inhibited depolarization-evoked glutamate release and cytosolic free Ca2+ concentration ([Ca2+]C) in the hippocampal nerve terminals. However, acacetin did not alter synaptosomal membrane potential. Furthermore, the inhibitory effect of acacetin on evoked glutamate release was prevented by the Cav2.2 (N-type) and Cav2.1 (P/Q-type) channel blocker known as ?-conotoxin MVIIC. In a kainic acid (KA) rat model, an animal model used for excitotoxic neurodegeneration experiments, acacetin (10 or 50 mg/kg) was administrated intraperitoneally to the rats 30 min before the KA (15 mg/kg) intraperitoneal injection, and subsequently induced the attenuation of KA-induced neuronal cell death and microglia activation in the CA3 region of the hippocampus. The present study demonstrates that the natural compound, acacetin, inhibits glutamate release from hippocampal synaptosomes by attenuating voltage-dependent Ca2+ entry and effectively prevents KA-induced in vivo excitotoxicity. Collectively, these data suggest that acacetin has the therapeutic potential for treating neurological diseases associated with excitotoxicity. PMID:24520409

Lin, Tzu-Yu; Huang, Wei-Jan; Wu, Chia-Chan; Lu, Cheng-Wei; Wang, Su-Jane

2014-01-01

222

Acid-sensitive channel inhibition prevents fetal alcohol spectrum disorders cerebellar Purkinje cell loss  

NSDL National Science Digital Library

Ethanol is now considered the most common human teratogen. Educational campaigns have not reduced the incidence of ethanol-mediated teratogenesis, leading to a growing interest in the development of therapeutic prevention or mitigation strategies. On the basis of the observation that maternal ethanol consumption reduces maternal and fetal pH, we hypothesized that a pH-sensitive pathway involving the TWIK-related acid-sensitive potassium channels (TASKs) is implicated in ethanol-induced injury to the fetal cerebellum, one of the most sensitive targets of prenatal ethanol exposure. Pregnant ewes were intravenously infused with ethanol (258 ± 10 mg/dl peak blood ethanol concentration) or saline in a "3 days/wk binge" pattern throughout the third trimester. Quantitative stereological analysis demonstrated that ethanol resulted in a 45% reduction in the total number of fetal cerebellar Purkinje cells, the cell type most sensitive to developmental ethanol exposure. Extracellular pH manipulation to create the same degree and pattern of pH fall caused by ethanol (manipulations large enough to inhibit TASK 1 channels), resulted in a 24% decrease in Purkinje cell number. We determined immunohistochemically that TASK 1 channels are expressed in Purkinje cells and that the TASK 3 isoform is expressed in granule cells of the ovine fetal cerebellum. Pharmacological blockade of both TASK 1 and TASK 3 channels simultaneous with ethanol effectively prevented any reduction in fetal cerebellar Purkinje cell number. These results demonstrate for the first time functional significance of fetal cerebellar two-pore domain pH-sensitive channels and establishes them as a potential therapeutic target for prevention of ethanol teratogenesis.

Jay Ramadoss (University of Wisconsin)

2008-05-22

223

Tachikawa project for prevention of posttraumatic stress disorder with polyunsaturated fatty acid (TPOP): study protocol for a randomized controlled trial  

PubMed Central

Background Preclinical and clinical studies suggest that supplementation with omega-3 fatty acids after trauma might reduce subsequent posttraumatic stress disorder (PTSD). To date, we have shown in an open trial that PTSD symptoms in critically injured patients can be reduced by taking omega-3 fatty acids, hypothesized to stimulate hippocampal neurogenesis. The primary aim of the present randomized controlled trial is to examine the efficacy of omega-3 fatty acid supplementation in the secondary prevention of PTSD following accidental injury, as compared with placebo. This paper describes the rationale and protocol of this trial. Methods/design The Tachikawa Project for Prevention of Posttraumatic Stress Disorder with Polyunsaturated Fatty Acid (TPOP) is a double-blinded, parallel group, randomized controlled trial to assess whether omega-3 fatty acid supplementation can prevent PTSD symptoms among accident-injured patients consecutively admitted to an intensive care unit. We plan to recruit accident-injured patients and follow them prospectively for 12 weeks. Enrolled patients will be randomized to either the omega-3 fatty acid supplement group (1,470 mg docosahexaenoic acid and 147 mg eicosapentaenoic acid daily) or placebo group. Primary outcome is score on the Clinician-Administered PTSD Scale (CAPS). We will need to randomize 140 injured patients to have 90% power to detect a 10-point difference in mean CAPS scores with omega-3 fatty acid supplementation compared with placebo. Secondary measures are diagnosis of PTSD and major depressive disorder, depressive symptoms, physiologic response in the experiment using script-driven imagery and acoustic stimulation, serum brain-derived neurotrophic factor, health-related quality of life, resilience, and aggression. Analyses will be by intent to treat. The trial was initiated on December 13 2008, with 104 subjects randomized by November 30 2012. Discussion This study promises to be the first trial to provide a novel prevention strategy for PTSD among traumatized people. Trial registration ClinicalTrials.gov Identifier NCT00671099 PMID:23289548

2013-01-01

224

Inhibition of polar calcium movement and gravitropism in roots treated with auxin-transport inhibitors  

NASA Technical Reports Server (NTRS)

Primary roots of maize (Zea mays L.) and pea (Pisum sativum L.) exhibit strong positive gravitropism. In both species, gravistimulation induces polar movement of calcium across the root tip from the upper side to the lower side. Roots of onion (Allium cepa L.) are not responsive to gravity and gravistimulation induces little or no polar movement of calcium across the root tip. Treatment of maize or pea roots with inhibitors of auxin transport (morphactin, naphthylphthalamic acid, 2,3,5-triiodobenzoic acid) prevents both gravitropism and gravity-induced polar movement of calcium across the root tip. The results indicate that calcium movement and auxin movement are closely linked in roots and that gravity-induced redistribution of calcium across the root cap may play an important role in the development of gravitropic curvature.

Lee, J. S.; Mulkey, T. J.; Evans, M. L.

1984-01-01

225

Crystal growth of calcium carbonate on the cellulose acetate/pyrrolidon blend films in the presence of L-aspartic acid  

NASA Astrophysics Data System (ADS)

The morphogenesis and growth process of calcium carbonate on the cellulose acetate/polyvinyl pyrrolidone (CA/PVP) blend films in the presence of L-aspartic acid was carefully investigated. The results showed that the concentration of L-aspartic acid, the initial pH value of reaction solution and temperature turned out to be important factors for the control of morphologies and polymorphs of calcium carbonate. Complex morphologies of CaCO3 particles, such as cubes, rose-like spheres, twinborn-spheres, cone-like, bouquet-like, etc. could be obtained under the different experimental conditions. The dynamic process of formation of rose-like sphere crystals was analyzed by monitoring the continuous morphological and structural evolution and components of crystals in different crystal stages. This research may provide a promising method to prepare other inorganic materials with complex morphologies.

Zhang, Xiuzhen; Xie, Anjian; Huang, Fangzhi; Shen, Yuhua

2014-03-01

226

Extracellular-derived calcium does not initiate in vivo neurotransmission involving docosahexaenoic acid  

PubMed Central

In vitro studies show that docosahexaenoic acid (DHA) can be released from membrane phospholipid by Ca2+-independent phospholipase A2 (iPLA2), Ca2+-independent plasmalogen PLA2 or secretory PLA2 (sPLA2), but not by Ca2+-dependent cytosolic PLA2 (cPLA2), which selectively releases arachidonic acid (AA). Since glutamatergic NMDA (N-methyl-D-aspartate) receptor activation allows extracellular Ca2+ into cells, we hypothesized that brain DHA signaling would not be altered in rats given NMDA, to the extent that in vivo signaling was mediated by Ca2+-independent mechanisms. Isotonic saline, a subconvulsive dose of NMDA (25 mg/kg), MK-801, or MK-801 followed by NMDA was administered i.p. to unanesthetized rats. Radiolabeled DHA or AA was infused intravenously and their brain incorporation coefficients k*, measures of signaling, were imaged with quantitative autoradiography. NMDA or MK-801 compared with saline did not alter k* for DHA in any of 81 brain regions examined, whereas NMDA produced widespread and significant increments in k* for AA. In conclusion, in vivo brain DHA but not AA signaling via NMDA receptors is independent of extracellular Ca2+ and of cPLA2. DHA signaling may be mediated by iPLA2, plasmalogen PLA2, or other enzymes insensitive to low concentrations of Ca2+. Greater AA than DHA release during glutamate-induced excitotoxicity could cause brain cell damage. PMID:20388940

Ramadan, Epolia; Rosa, Angelo O.; Chang, Lisa; Chen, Mei; Rapoport, Stanley I.; Basselin, Mireille

2010-01-01

227

Biomedical nanocomposites of poly(lactic acid) and calcium phosphate hybridized with modified carbon nanotubes for hard tissue implants.  

PubMed

Degradable polymer-based materials are attractive in orthopedics and dentistry as an alternative to metallic implants for use as bone fixatives. Herein, a degradable polymer poly(lactic acid) (PLA) was combined with novel hybrid nanopowder of carbon nanotubes (CNTs)-calcium phosphate (CP) for this application. In particular, CNTs-CP hybrid nanopowders (0.1 and 0.25% CNTs) were prepared from the solution of ionically modified CNTs (mCNTs), which was specifically synthesized to be well-dispersed and thus to effectively adsorb onto the CP nanoparticles. The mCNTs-CP hybrid nanopowders were then mixed with PLA (up to 50%) to produce mCNTs-CP-PLA nanocomposites. The mechanical tensile strength of the nanocomposites was significantly improved by the addition of mCNTs-CP hybrid nanopowders. Moreover, nanocomposites containing low concentration of mCNTs (0.1%) showed significantly stimulated biological responses including cell proliferation and osteoblastic differentiation in terms of gene and protein expressions. Based on this study, the addition of novel mCNT-CP hybrid nanopowders to PLA biopolymer may be considered a new material choice for developing hard tissue implants. PMID:21591250

Lee, Hae-Hyoung; Sang Shin, Ueon; Lee, Jae-Ho; Kim, Hae-Won

2011-08-01

228

Intake, performance, and efficiency of nutrient utilization in Saanen goat kids fed diets containing calcium salts of fatty acids.  

PubMed

The objective of this study was to evaluate the effect of feeding Saanen goat kids with calcium salts of fatty acids (CSFA) in diet, on intake, performance, digestibility of nutrients, and blood parameters. Twenty-eight uncastrated male goat kids, with round average age to 112.86?±?4.81 days and an average body weight (BW) of 19.54?±?2.76 kg, were distributed in a completely randomized design distributed into four groups with seven animals per group: one control group fed a diet containing 2.5 Mcal metabolizable energy (ME)/kg dry matter (DM) and three groups fed a diet containing 2.6, 2.7, or 2.8 Mcal ME/kg DM, with CSFA added to increase the energy levels. The animals were fed the diets until they reached an average BW of 28 kg. There was hardly any apparent effect of dietary CSFA on intake of DM and organic matter (OM). The digestibility of DM and OM showed an improvement with 2.64 and 2.65 Mcal ME/kg DM in the diet. The diets containing CSFA improved average daily gain and reduced the time on the feedlot to 30 days fed diet with 2.8 Mcal ME/kg DM. However, lipid supplementation increased serum cholesterol levels. Thus, CSFA can be used to increase the energy density of the diet in finisher Saanen goat kids and improve performance by reducing days on feedlot. PMID:25367279

Possamai, Ana Paula Silva; Alcalde, Claudete Regina; de Souza, Rodrigo; Gomes, Ludmila Couto; de Macedo, Francisco de Assis Fonseca; Martins, Elias Nunes

2015-01-01

229

Effects of supplementing with calcium salts of palm oil fatty acids or hydrogenated tallow on ewe milk production and twin lamb growth1  

Microsoft Academic Search

Two experiments were conducted with Polypay ewes nursing twin lambs to evaluate the effects of supplementing fat (calcium salts of palm oil fatty acids or hydrogenated tallow) on ewe lactation. In Exp. 1, ewes were fed a 52% concentrate:48% hay-based diet (as-fed basis) consisting of alfalfa hay (n = 4), endo- phyte-free fescue hay (n = 4), or fescue hay

L. A. Appeddu; D. G. Ely; D. K. Aaron; W. P. Deweese; E. Fink

230

Calcium homeostasis, acid–base balance, and health status in periparturient Holstein cows fed diets with low cation–anion difference  

Microsoft Academic Search

Forty multiparous Holstein dry cows on d 21 prepartum were randomly allocated to four blocks of 10 cows to examine the effects of reducing the dietary cation–anion difference (DCAD) on calcium homeostasis, acid–base balance, health status, and subsequent lactation performance. The reduced DCADs (Na+K?Cl?S, mEq\\/kg DM) of +150,+50, ?50, and ?150 were obtained by addition of anionic salts. Reducing DCAD

W. X. Wu; J. X. Liu; G. Z. Xu; J. A. Ye

2008-01-01

231

Tauroursodeoxycholic acid (TUDCA) supplementation prevents cognitive impairment and amyloid deposition in APP/PS1 mice.  

PubMed

Alzheimer's disease (AD) is a neurodegenerative disease hallmarked by extracellular A?(1-42) containing plaques, and intracellular neurofibrillary tangles (NFT) containing hyperphosphorylated tau protein. Progressively, memory deficits and cognitive disabilities start to occur as these hallmarks affect hippocampus and frontal cortex, regions highly involved in memory. Connective tissue growth factor (CTGF) expression, which is high in the vicinity of A? plaques and NFTs, was found to influence ?-secretase activity, the molecular crux in A?(1-42) production. Tauroursodeoxycholic acid (TUDCA) is an endogenous bile acid that downregulates CTGF expression in hepatocytes and has been shown to possess therapeutic efficacy in neurodegenerative models. To investigate the possible in vivo therapeutic effects of TUDCA, we provided 0.4% TUDCA-supplemented food to APP/PS1 mice, a well-established AD mouse model. Six months of TUDCA supplementation prevented the spatial, recognition and contextual memory defects observed in APP/PS1 mice at 8 months of age. Furthermore, TUDCA-supplemented APP/PS1 mice displayed reduced hippocampal and prefrontal amyloid deposition. These effects of TUDCA supplementation suggest a novel mechanistic route for Alzheimer therapeutics. PMID:22974733

Lo, Adrian C; Callaerts-Vegh, Zsuzsanna; Nunes, Ana F; Rodrigues, Cecília M P; D'Hooge, Rudi

2013-02-01

232

Lack of effect of eicosapentaenoic acid in preventing cancer cachexia and inhibiting tumor growth.  

PubMed

It has been recently reported that a diet enriched in n-3 polyunsaturated fatty acids reduces the growth of different kinds of tumors as well as the host tissue hypercatabolic state frequently associated. The rat ascites hepatoma Yoshida AH-130 is a fast growing tumor that causes a rapid and progressive body weight loss in the host and tissue waste associated with a hypercatabolic condition. Plasma levels of classical hormones and humoral mediators (prostaglandin E2 and tumor necrosis factor-alpha) are early perturbed after tumor transplantation (Tessitore, L., Costelli, P. and Baccino, F.M. (1993) Humoral mediation for cachexia in tumour-bearing rats. Br. J. Cancer, 67, 16-23). Enhanced protein degradation rates and alteration of lipoprotein lipase activity mainly account for the wasting of protein and adipose mass, respectively. However, the daily intragastric administration of eicosapentaenoic acid (1.5 g/kg body wt) to AH-130 bearing rats was completely ineffective either in preventing tissue waste or in reducing tumor growth. The low degree of differentiation and the high growth rate of the AH0130 hepatoma probably account for this lack of effect. PMID:7585474

Costelli, P; Llovera, M; López-Soriano, J; Carbó, N; Tessitore, L; López-Soriano, F J; Baccino, F M; Argilés, J M

1995-10-20

233

Sulfur and chlorine play a non-acid base role in periparturient calcium homeostasis.  

PubMed

The increased risk of periparturient hypocalcaemia through offering high-K feeds in the precalving period has been reported previously. Two experiments (experiment 1 and 2) investigated the effect of KCl fertilizer on pasture mineral concentration, the dietary cation-anion difference (DCAD), and the subsequent effect of this on periparturient plasma and urine mineral status. Experiment 2 examined the effect of precalving Mg source (MgO, MgSO4, and MgCl2) and postcalving Ca supplementation on the concentration of Ca and Mg in plasma and urine. Unexpectedly, pasture DCAD increased (P = 0.06) from 434 to 535 mEq/kg DM in experiment 1 as pasture K concentration decreased from 4.2 to 3.5%, primarily because of a corresponding and greater decrease in pasture Cl concentration (from 1.9 to 1.3%). Plasma Ca or Mg concentrations were not affected by pasture K concentration. A linear decline (P < 0.10) in urine Mg suggested a decline in Mg absorption as pasture K increased. In experiment 2, pasture DCAD decreased (P < 0.05) linearly from 403 to 350 mEq/kg DM as pasture K concentration decreased from 3.8 to 3.3%. However, precalving urine pH was not affected by the declining DCAD. Postcalving plasma Ca concentration was affected by precalving Mg source with MgSO4 > MgCl2 > MgO. Differences in acid-base balance do not explain the difference between Mg salts. These results indicate that precalving dietary S and Cl concentration plays an important role in Ca homeostasis, in addition to its role in acid-base balance. Supplementation with Ca postcalving increased plasma Ca concentration for 2 d postcalving. Milk production was not affected. PMID:12512617

Roche, J R; Morton, J; Kolver, E S

2002-12-01

234

Effect of supplementation with calcium salts of fish oil on n-3 fatty acids in milk fat.  

PubMed

Enrichment of milk fat with n-3 fatty acids, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may be advantageous because of their beneficial effects on human health. In addition, these fatty acids play an important role in reproductive processes in dairy cows. Our objective was to evaluate the protection of EPA and DHA against rumen biohydrogenation provided by Ca salts of fish oil. Four Holstein cows were assigned in a Latin square design to the following treatments: 1) ruminal infusion of Ca salts of fish oil and palm fatty acid distillate low dose (CaFO-1), 2) ruminal infusion of Ca salts of fish oil and palm fatty acid distillate high dose (CaFO-2), 3) ruminal infusion of fish oil high dose (RFO), and 4) abomasal infusion of fish oil high dose (AFO). The high dose of fish oil provided approximately 16 and approximately 21 g/d of EPA and DHA, respectively, whereas the low dose (CaFO-1) provided 50% of these amounts. A 10-d pretreatment period was used as a baseline, followed by 9-d treatment periods with interceding intervals of 10 d. Supplements were infused every 6 h, milk samples were taken the last 3 d, and plasma samples were collected the last day of baseline and treatment periods. Milk fat content of EPA and DHA were 5 to 6 times greater with AFO, but did not differ among other treatments. Milk and milk protein yield were unaffected by treatment, but milk fat yield and DM intake were reduced by 20 and 15%, respectively, by RFO. Overall, results indicate rumen biohydrogenation of long chain n-3 fatty acids was extensive, averaging >85% for EPA and >75% for DHA for the Ca salts and unprotected fish oil supplements. Thus, Ca salts of fish oil offered no protection against the biohydrogenation of EPA and DHA beyond that observed with unprotected fish oil; however, the Ca salts did provide rumen inertness by preventing the negative effects on DM intake and milk fat yield observed with unprotected fish oil. PMID:17699033

Castañeda-Gutiérrez, E; de Veth, M J; Lock, A L; Dwyer, D A; Murphy, K D; Bauman, D E

2007-09-01

235

Tumor necrosis factor alpha protects heart cultures against hypoxic damage via activation of PKA and phospholamban to prevent calcium overload.  

PubMed

This study aims to elucidate the mechanisms by which tumor necrosis factor alpha (TNF?) provides protection from hypoxic damage to neonatal rat cardiomyocyte cultures. We show that when intracellular Ca(2+) ([Ca(2+)]i) levels are elevated by extracellular Ca(2+) ([Ca(2+)]o) or by hypoxia, then TNF? decreased [Ca(2+)]i in individual cardiomyocytes. However, TNF? did not reduce [Ca(2+)]i after its increase by thapsigargin, (a SERCA2a inhibitor), indicating that TNF? attenuates Ca(2+) overload through Ca(2+) uptake by SERCA2a. TNF? did not reduce [Ca(2+)]i, following its elevation when [Ca(2+)]o levels were elevated in TNF? receptor knock-out mice. H-89, a protein kinase A (PKA) inhibitor, attenuated the protective effect of TNF? when the cardiomyoctyes were subjected to hypoxia, as determined by lactate dehydrogenase (LDH) and creatine kinase (CK) released and from the cardiomyocytes. Moreover, when the levels of [Ca(2+)]i were increased by hypoxia, H-89, but not KN93, (a calmodulin kinase II inhibitor), prevented the reduction in [Ca(2+)]i by TNF?. TNF? increased the phosphorylation of PKA in normoxic and hypoxic cardiomyoctes, indicating that the cardioprotective effect of TNF? against hypoxic damage was via PKA activation. Hypoxia decreased phosphorylated phospholamban levels; however, TNF? attenuated this decrease following hypoxia. It is suggested that TNF? activates phospholamban phosphorylation in hypoxic heart cultures via PKA to stimulate SERCA2a activity to limit Ca(2+) overload. PMID:25349921

El-Ani, Dalia; Philipchik, Irena; Stav, Hagit; Levi, Moran; Zerbib, Jordana; Shainberg, Asher

2014-11-01

236

Isradipine prevents rotenone-induced intracellular calcium rise that accelerates senescence in human neuroblastoma SH-SY5Y cells.  

PubMed

Previous research demonstrated that rotenone (RT) induces neuronal injury partially by increasing intracellular Ca(2+) concentrations ([Ca(2+)]i), and inducing oxidative stress, leading to a neurodegenerative disorder. However, the mechanism of RT-induced injury remains elusive. Recent work revealed that Ca(2+) signaling is important for RT-induced senescence in human neuroblastoma SH-SY5Y cells. In the present study, we found that in SH-SY5Y cells, RT increased [Ca(2+)]i, senescence associated ?-galactosidase activity, aggregation of lipofuscin, production of reactive oxygen species, G1/G0 cell cycle arrest, and activation of p53/p21 signaling proteins. In addition, RT decreased the expression of the signaling proteins for cell proliferation and survival, Cyclin-dependent kinase 2 (CDK2), cyclin D1, and Akt. Pretreatment of SH-SY5Y cells with isradipine, an L-type Ca(2+) channel blocker, or EGTA antagonized these effects of RT. These results suggested that application of isradipine might be a novel approach to prevent RT-induced neurodegenerative disorder such as Parkinson's disease. PMID:23664925

Yu, X; Li, X; Jiang, G; Wang, X; Chang, H C; Hsu, W H; Li, Qinglin

2013-08-29

237

Assessment of high performance concrete containing fly ash and calcium nitrite based corrosion inhibitor as a mean to prevent the corrosion of reinforcing steel  

NASA Astrophysics Data System (ADS)

This research analyses the effectiveness of the water-to-cement ratio (w/c), fly ash and a calcium nitrite based corrosion inhibitor to prevent the corrosion of reinforcing steel embedded in high performance concrete. The interactive effect between the inhibitor and fly ash was evaluated because the occurrence of a negative effect when both ingredients are added together in a concrete mixture has been reported. All the concrete mixtures studied in this investigation had 8.2% of silica fume. Twenty seven prismatic concrete specimens were fabricated with dimensions of 55 × 230 × 300 mm each containing two steel rods embedded for the purpose of corrosion monitoring. The specimens were exposed to a simulated marine environment with two daily cycles of wetting and drying for one year. To evaluate the deterioration of the specimens corrosion potentials and linear polarization resistance tests were carried out. The results indicate that the use of a low w/c, the addition of fly ash and the addition of the corrosion inhibitor contributed to the reduction of the corrosion of steel in the concrete specimens. The results further suggest that the combination of fly ash and corrosion inhibitor does not promote the deterioration of the concrete matrix.

Montes-García, P.; Jiménez-Quero, V.; López-Calvo, H.

2015-01-01

238

miR-786 Regulation of a Fatty-Acid Elongase Contributes to Rhythmic Calcium-Wave Initiation in C. elegans  

PubMed Central

Summary Background Rhythmic behaviors are ubiquitous phenomena in animals. In C. elegans, defecation is an ultradian rhythmic behavior: every ~50 s a calcium wave initiating in the posterior intestinal cells triggers the defecation motor program that comprises three sequential muscle contractions. Oscillatory calcium signaling is central to the periodicity of defecation. The posteriormost intestinal cells function as the pacemaker for this rhythmic behavior, although it is unclear how the supremacy of these cells for calcium-wave initiation is controlled. Results We describe how the loss of the mir-240/786 micro-RNA cluster, which results in arrhythmic defecation, causes ectopic intestinal calcium-wave initiation. mir-240/786 expression in the intestine is restricted to the posterior cells that function as the defecation pacemaker. Genetic data indicate that mir-240/786 functions upstream of the inositol 1,4,5-trisphosphate (IP3) receptor. Through rescue analysis, it was determined that miR-786 functions to regulate defecation. Furthermore, we identified elo-2, a fatty-acid elongase with a known role in defecation cycling, as a direct target for miR-786.We propose that the regulation of palmitate levels through repression of elo-2 activity is the likely mechanistic link to defecation. Conclusions Together, these data indicate that miR-786 confers pacemaker status on posterior intestinal cells for the control of calcium-wave initiation through the regulation of elo-2 and, subsequently, palmitate levels. We propose that a difference in fatty-acid composition in the posterior intestinal cells may alter the activities of membrane proteins, such as IP3-receptor or TRPM channels, that control pacemaker activity in the C. elegans intestine. PMID:23141108

Kemp, Benedict J.; Allman, Erik; Immerman, Lois; Mohnen, Megan; Peters, Maureen A.; Nehrke, Keith; Abbott, Allison L.

2012-01-01

239

Water, acid, and calcium carbonate pretreatment of fly ash: The effect on setting of cement-fly ash mixtures  

SciTech Connect

The treatment of class C, I, and F fly ash (FA) with water, HNO{sub 3}, and aqueous CaCO{sub 3} has been investigated to develop a simple chemical route to change the morphology and surface chemistry of fly ash particles to enhance the setting properties of a cement/fly ash (C/FA) composite. The treatment of C-FA with an aqueous CaCO{sub 3} solution results in a dramatic improvement in the setting time and the setting profile on C-class FA; in contrast, the treatment has no effect on the set time for F-FA and reduces the set time and appears to result in an even more nonideal induction setting curve as compared to the untreated C/I-FA. The enhancement observed for the treatment of C-FA with aqueous CaCO{sub 3} solution is not a consequence of the water solution since simply washing with water (i.e., C-FA(H{sub 2}O)) results in the extraction of Na and Ca with a concomitant increase in surface area and a performance similar to those observed for untreated I-FA and F-FA despite a much higher surface area. The acid (HNO{sub 3}) treatment of I-FA and F-FA results in the formation of an inert filler-like material, while acid treatment of C-FA results in a material with completely undesirable setting properties. Clearly, the enhancements observed for the aqueous CaCO{sub 3} treatment are not as a result of simply either the aqueous or acidic nature of the HCO{sub 3} containing CaCO{sub 3} solution. Based upon the forgoing, we propose that the efficacy of the aqueous CaCO{sub 3} treatment on C-FA is associated with the availability of 'reactive calcium'. Exposure of C-FA to dry CO{sub 2} does not affect the set time or set profile for C/C-FA mixture, but the retarding effect of the aqueous CaCO{sub 3} treatment on C-FA can be replicated by the exposure of the C-FA to a stepwise reaction with water and CO{sub 2}. Exposure of C-FA to wet CO{sub 2} results in the improvement of the setting induction profile without significantly affecting the set time.

Lupu, C.; Jackson, K.L.; Bard, S.; Barron, A.R. [Rice University, Houston, TX (United States)

2007-11-15

240

Eicosapentaenoic acid prevents high fat diet-induced metabolic disorders: Genomic and metabolomic analyses of underlying mechanism  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previously our lab demonstrated eicosapenaenoic acid (EPA)'s ability to prevent high-fat (HF) diet-induced obesity by decreasing insulin resistance, glucose intolerance and inflammation. In the current study, we used genomic and metabolomic approaches to further investigate the molecular basis for t...

241

Efficiency of Sulfuric Acid, Mined Gypsum, and Two Gypsum By-Products in Soil Crusting Prevention and Sodic Soil Reclamation  

Microsoft Academic Search

face runoff and erosion (Sumner and Stewart, 1992). Al- though not properly quantified, soil crusting has been Sulfuric acid and gypsum-like by-products are potentially effective identified as a moderate to severe problem in different amendments in preventing soil crusting and reclaiming calcareous sodic soils. However, their relative efficiencies at chemically equiva- soils of the middle Ebro River Basin (Spain), whereas

E. Amezketa; R. Aragüés; R. Gazol

2005-01-01

242

Tauroursodeoxycholic acid prevents MPTP-induced dopaminergic cell death in a mouse model of Parkinson's disease.  

PubMed

Mitochondrial dysfunction and oxidative stress are implicated in the neurodegenerative process in Parkinson's disease (PD). Moreover, c-Jun N-terminal kinase (JNK) plays an important role in dopaminergic neuronal death in substantia nigra pars compacta. Tauroursodeoxycholic acid (TUDCA) acts as a mitochondrial stabilizer and anti-apoptotic agent in several models of neurodegenerative diseases. Here, we investigated the role of TUDCA in preventing 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurodegeneration in a mouse model of PD. We evaluated whether TUDCA modulates MPTP-induced degeneration of dopaminergic neurons in the nigrostriatal axis, and if that can be explained by regulation of JNK phosphorylation, reactive oxygen species (ROS) production, glutathione S-transferase (GST) catalytic activation, and Akt signaling, using C57BL/6 glutathione S-transferase pi (GSTP) null mice. TUDCA efficiently protected against MPTP-induced dopaminergic degeneration. We have previously demonstrated that exacerbated JNK activation in GSTP null mice resulted in increased susceptibility to MPTP neurotoxicity. Interestingly, pre-treatment with TUDCA prevented MPTP-induced JNK phosphorylation in mouse midbrain and striatum. Moreover, the anti-oxidative role of TUDCA was demonstrated in vivo by impairment of ROS production in the presence of MPTP. Finally, results herein suggest that the survival pathway activated by TUDCA involves Akt signaling, including downstream Bad phosphorylation and NF-?B activation. We conclude that TUDCA is neuroprotective in an in vivo model of PD, acting mainly by modulation of JNK activity and cellular redox thresholds, together with activation of the Akt pro-survival pathway. These results open new perspectives for the pharmacological use of TUDCA, as a modulator of neurodegeneration in PD. PMID:22773138

Castro-Caldas, M; Carvalho, A Neves; Rodrigues, E; Henderson, C J; Wolf, C R; Rodrigues, C M P; Gama, M J

2012-10-01

243

Omega-3 fatty acids for the prevention of breast cancer: an update and state of the science.  

PubMed

The quantity and makeup of dietary fat intake are known to impact human health. Use of Omega-3 (?-3) polyunsaturated fatty acid (PUFA) supplements has gained increasing attention for a variety of purported health benefits, including cancer prevention. Preclinical evidence has been encouraging and recent studies have expanded our understanding of the mechanisms by which ?-3 PUFAs may protect against breast cancer. However, epidemiologic studies have yielded mixed results. Recent population studies have attempted to delineate factors that may influence the effects of ?-3 PUFAs such as total fat intake and the ratio of ?-3 to ?-6 PUFA intake. Several clinical trials, including some currently ongoing, are investigating novel strategies that favorably alter endogenous fatty acid profiles in an effort to develop clinically feasible prevention methods. Identification of well-defined subpopulations that are most likely to benefit from a targeted prevention approach will likely be crucial in this effort. PMID:24073296

Iyengar, Neil M; Hudis, Clifford A; Gucalp, Ayca

2013-09-01

244

Renal Outcomes in High-Risk Hypertensive Patients Treated With an Angiotensin-Converting Enzyme Inhibitor or a Calcium Channel Blocker vs. a Diuretic. A Report From the Antihypertensive and Lipid-lowering Treatment to Prevent Heart Attack Trial (ALLHAT)  

Microsoft Academic Search

Background: This study was performed to determine whether, in high-risk hypertensive patients with a re- duced glomerular filtration rate (GFR), treatment with a calcium channel blocker or an angiotensin-converting enzyme inhibitor lowers the incidence of renal disease outcomes compared with treatment with a diuretic. Methods: We conducted post hoc analyses of the Anti- hypertensive and Lipid-Lowering Treatment to Prevent Heart

Mahboob Rahman; Sara Pressel; Barry R. Davis

2005-01-01

245

Berries and Ellagic Acid Prevent Estrogen-Induced Mammary Tumorigenesis by Modulating Enzymes of Estrogen Metabolism  

PubMed Central

In order to determine whether dietary berries and ellagic acid prevent 17? estradiol (E2) -induced mammary tumors by altering estrogen metabolism, we randomized ACI rats (n=6/group) into 5 groups ? sham implant + control diet (SH-CD), E2 ? implant + control diet (E2-CD), E2+2.5% black raspberry (E2-BRB); E2+2.5% blueberry (E2-BB) and E2+ 400ppm ellagic acid (E2-EA). Animals were euthanized at early (6wk), intermediate (18wk) and late (24wk) phases of E2-carcinogenesis and the mammary tissue analyzed for gene-expression changes using quantitative real-time PCR. At 6 weeks, E2-treatment caused 48-fold increase in cytochrome P4501A1(CYP1A1) (p<0.0001), which was attenuated by both BRB and BB diets to 12- and 21-fold, respectively (p<0.001). E2 did not alter CYP1B1 levels, but both berry and EA diets significantly suppressed it by 11- and 3.5-fold, respectively from baseline (p<0.05). There was a 5-fold increase in 17?-Hydroxysteroid dehyrdogenase(17?HSD7) and this was moderately abrogated to about 2-fold by all supplementation (p<0.05). At 18 weeks, CYP1A1 was elevated by 15-fold in E2-CD and only E2-BB reduced this increase to 7-fold (p<0.05). Catechol-O-methyl transferase(COMT) expression was elevated 2-fold by E2-treatment (p<0.05) and all supplementation reversed this. At 24 weeks, CYP1A1 expression was less pronounced, but still high (8-fold) in E2-treated rats. This increase was reduced to 3.2 and 4.6-fold, by E2-BRB and E2-EA, respectively (p<0.05), but not by E2-BB. Supplementation did not alter the effect of E2 on steroid receptors. The diets also significantly suppressed mammary tumor incidence (10–30%), volume (41–67%) and multiplicity (38 to 51%) (p<0.05). Berries may prevent mammary tumors by suppressing the levels of E2-metabolizing enzymes during the early phase of E2-carcinogenesis. PMID:20501861

Aiyer, Harini S.; Gupta, Ramesh C.

2010-01-01

246

Inhibition of UV-induced uric acid production using allopurinol prevents suppression of the contact hypersensitivity response.  

PubMed

Exposure to solar ultraviolet (UV) radiation suppresses adaptive immune responses. This contributes to skin carcinogenesis but may protect from some autoimmune diseases. However, the molecular changes occurring within UV-exposed skin that precipitate the downstream events leading to immune suppression are not fully understood. Using a combination of in vitro and in vivo mouse models, we have discovered that UV induces significant cutaneous production of immune suppressive uric acid. The ability of UV-induced uric acid to inhibit a contact hypersensitivity response was successfully blocked by the gout-treating drug Allopurinol. Up-regulation of NLRP3 mRNA by UV was also found to be dependent on UV-induced uric acid. This suggested that the target of UV-induced uric acid included proteins involved in the formation and activation of the NLRP3-inflammasome. However, in contrast to NLRP3, the adaptor protein ASC, which is required for formation of the NLRP3-inflammasome, was significantly down-regulated. Furthermore, this down-regulation was not dependent on UV-induced uric acid production because Allopurinol treatment failed to prevent the reduction in ASC. Hence, our results identify uric acid as an important molecule involved in sterile UV-induced inflammation and immune suppression. UV-induced uric acid may therefore offer a unique therapeutic target for preventing and treating skin cancer. PMID:23387472

Leighton, Sarah; Kok, Lai-Fong; Halliday, Gary M; Byrne, Scott N

2013-03-01

247

Valproic acid prevents retinal degeneration in a murine model of normal tension glaucoma.  

PubMed

Valproic acid (VPA) is widely used for treatment of epilepsy, mood disorders, migraines and neuropathic pain. It exerts its therapeutic benefits through modulation of multiple mechanisms including regulation of gamma-aminobutyric acid and glutamate neurotransmissions, activation of pro-survival protein kinases and inhibition of histone deacetylase. The evidence for neuroprotective properties associated with VPA is emerging. Herein, we investigated the therapeutic potential of VPA in a mouse model of normal tension glaucoma (NTG). Mice with glutamate/aspartate transporter gene deletion (GLAST KO mice) demonstrate progressive retinal ganglion cell (RGC) loss and optic nerve degeneration without elevated intraocular pressure, and exhibit glaucomatous pathology including glutamate neurotoxicity and oxidative stress in the retina. VPA (300mg/kg) or vehicle (PBS) was administered via intraperitoneal injection in GLAST KO mice daily for 2 weeks from the age of 3 weeks, which coincides with the onset of glaucomatous retinal degeneration. Following completion of the treatment period, the vehicle-treated GLAST KO mouse retina showed significant RGC death. Meanwhile, VPA treatment prevented RGC death and thinning of the inner retinal layer in GLAST KO mice. In addition, in vivo electrophysiological analyses demonstrated that visual impairment observed in vehicle-treated GLAST KO mice was ameliorated with VPA treatment, clearly establishing that VPA beneficially affects both histological and functional aspects of the glaucomatous retina. We found that VPA reduces oxidative stress induced in the GLAST KO retina and stimulates the cell survival signalling pathway associated with extracellular-signal-regulated kinases (ERK). This is the first study to report the neuroprotective effects of VPA in an animal model of NTG. Our findings raise intriguing possibilities that the widely prescribed drug VPA may be a novel candidate for treatment of glaucoma. PMID:25555796

Kimura, Atsuko; Guo, Xiaoli; Noro, Takahiko; Harada, Chikako; Tanaka, Kohichi; Namekata, Kazuhiko; Harada, Takayuki

2015-02-19

248

Calcium Carbonate  

MedlinePLUS

Calcium carbonate is a dietary supplement used when the amount of calcium taken in the diet is not ... for healthy bones, muscles, nervous system, and heart. Calcium carbonate also is used as an antacid to relieve ...

249

Betulinic acid prevents alcohol-induced liver damage by improving the antioxidant system in mice  

PubMed Central

Betulinic acid (BA), a pentacyclic lupane-type triterpene, has a wide range of bioactivities. The main objective of this work was to evaluate the hepatoprotective activity of BA and the potential mechanism underlying the ability of this compound to prevent liver damage induced by alcohol in vivo. Mice were given oral doses of BA (0.25, 0.5, and 1.0 mg/kg) daily for 14 days, and induced liver injury by feeding 50% alcohol orally at the dosage of 10 ml/kg after 1 h last administration of BA. BA pretreatment significantly reduced the serum levels of alanine transaminase, aspartate transaminase, total cholesterol, and triacylglycerides in a dose-dependent manner in the mice administered alcohol. Hepatic levels of glutathione, superoxide dismutase, glutathione peroxidase, and catalase were remarkably increased, while malondialdehyde contents and microvesicular steatosis in the liver were decreased by BA in a dose-dependent manner after alcohol-induced liver injury. These findings suggest that the mechanism underlying the hepatoprotective effects of BA might be due to increased antioxidant capacity, mainly through improvement of the tissue redox system, maintenance of the antioxidant system, and decreased lipid peroxidation in the liver. PMID:24378582

Xia, Wei; Wu, Jianping; Yuan, Liyun; Wu, Jing; Tu, Di; Fang, Jun

2014-01-01

250

Salicylic acid prevents Trichoderma harzianum from entering the vascular system of roots.  

PubMed

Trichoderma is a soil-borne fungal genus that includes species with a significant impact on agriculture and industrial processes. Some Trichoderma strains exert beneficial effects in plants through root colonization, although little is known about how this interaction takes place. To better understand this process, the root colonization of wild-type Arabidopsis and the salicylic acid (SA)-impaired mutant sid2 by a green fluorescent protein (GFP)-marked Trichoderma harzianum strain was followed under confocal microscopy. Trichoderma harzianum?GFP22 was able to penetrate the vascular tissue of the sid2 mutant because of the absence of callose deposition in the cell wall of root cells. In addition, a higher colonization of sid2 roots by GFP22 compared with that in Arabidopsis wild-type roots was detected by real-time polymerase chain reaction. These results, together with differences in the expression levels of plant defence genes in the roots of both interactions, support a key role for SA in Trichoderma early root colonization stages. We observed that, without the support of SA, plants were unable to prevent the arrival of the fungus in the vascular system and its spread into aerial parts, leading to later collapse. PMID:24684632

Alonso-Ramírez, Ana; Poveda, Jorge; Martín, Ignacio; Hermosa, Rosa; Monte, Enrique; Nicolás, Carlos

2014-10-01

251

Orphenadrine prevents 3-nitropropionic acid-induced neurotoxicity in vitro and in vivo  

PubMed Central

Previous studies indicate that 3-nitropropionic acid (3-NPA) neurotoxicity involves the excitotoxic activation of N-methyl-D-aspartate (NMDA) receptors. Thus, we examined the effect of orphenadrine (an anticholinergic drug with NMDA receptor antagonist properties) on 3-NPA neurotoxicity in both cultured rat cerebellar granule cells (CGCs) and in rats. Orphenadrine protected CGCs from 3-NPA-induced mortality, as assessed by both the neutral red viability assay and laser scanning cytometry, using propidium iodide staining. For rats, two indirect markers of neuronal damage were used: the binding of [3H]-PK 11195 to the peripheral-type benzodiazepine receptor (PBR), a microglial marker, and expression of the 27?kD heat-shock protein (HSP27), a marker of activated astroglia. Systemic administration of 3-NPA (30?mg?kg?1 per day for 3 days) induced a 170% increase in [3H]-PK 11195 binding, and expression of HSP27. Both the increase in [3H]-PK 11195 and HSP 27 expression were prevented by previous administration of 30?mg?kg?1 per day of orphenadrine for 3 days. Lower doses (10 and 20?mg?kg?1) had no protective effect. Orphenadrine also reduced 3-NPA-induced mortality in a dose-dependent manner. We propose that orphenadrine or orphenadrine-like drugs could be used to treat neurodegenerative disorders mediated by overactivation of NMDA receptors. PMID:11159722

Pubill, David; Verdaguer, Ester; Canudas, Anna Ma; Sureda, Francesc Xavier; Escubedo, Elena; Camarasa, Jordi; Pallàs, Merce; Camins, Antoni

2001-01-01

252

RapA2 Is a Calcium-binding Lectin Composed of Two Highly Conserved Cadherin-like Domains That Specifically Recognize Rhizobium leguminosarum Acidic Exopolysaccharides*  

PubMed Central

In silico analyses have revealed a conserved protein domain (CHDL) widely present in bacteria that has significant structural similarity to eukaryotic cadherins. A CHDL domain was shown to be present in RapA, a protein that is involved in autoaggregation of Rhizobium cells, biofilm formation, and adhesion to plant roots as shown by us and others. Structural similarity to cadherins suggested calcium-dependent oligomerization of CHDL domains as a mechanistic basis for RapA action. Here we show by circular dichroism spectroscopy, light scattering, isothermal titration calorimetry, and other methods that RapA2 from Rhizobium leguminosarum indeed exhibits a cadherin-like ?-sheet conformation and that its proper folding and stability are dependent on the binding of one calcium ion per protein molecule. By further in silico analysis we also reveal that RapA2 consists of two CHDL domains and expand the range of CHDL-containing proteins in bacteria and archaea. However, light scattering assays at various concentrations of added calcium revealed that RapA2 formed neither homo-oligomers nor hetero-oligomers with RapB (a distinct CHDL protein), indicating that RapA2 does not mediate cellular interactions through a cadherin-like mechanism. Instead, we demonstrate that RapA2 interacts specifically with the acidic exopolysaccharides (EPSs) produced by R. leguminosarum in a calcium-dependent manner, sustaining a role of these proteins in the development of the biofilm matrix made of EPS. Because EPS binding by RapA2 can only be attributed to its two CHDL domains, we propose that RapA2 is a calcium-dependent lectin and that CHDL domains in various bacterial and archaeal proteins confer carbohydrate binding activity to these proteins. PMID:23235153

Abdian, Patricia L.; Caramelo, Julio J.; Ausmees, Nora; Zorreguieta, Angeles

2013-01-01

253

Docosahexaenoic acid supplementation modifies fatty acid incorporation in tissues and prevents hypoxia induced-atherosclerosis progression in apolipoprotein-E deficient mice.  

PubMed

The n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA), displays anti-inflammatory properties that may prevent atherosclerosis progression. Exposure of apolipoprotein-E deficient (ApoE(-/-)) mice to chronic intermittent hypoxia (CIH) accelerates atherosclerosis progression. Our aim was to assess DHA-supplementation influence on fatty acid incorporation in different tissues/organs and on atherosclerosis progression in ApoE(-/-) mice exposed to CIH. ApoE(-/-) mice were exposed to CIH or normoxia (N) and randomized to four groups (N control, CIH control, N+DHA, and CIH+DHA). DHA-supplementation enhanced DHA and reduced arachidonic acid (AA) contents in tissues/organs. CIH control mice exhibited increased atherosclerosis lesion sizes compared to N control mice. DHA prevented CIH induced atherosclerosis but did not improve atherosclerosis burden in N mice. Aortic matrix metalloproteinase-2 (MMP-2) expression was decreased in CIH+DHA mice (p=0.007). DHA-supplementation prevented CIH-induced atherosclerosis acceleration. This was associated with a decrease of AA incorporation and of aortic MMP-2 gene expression. PMID:25139400

Van Noolen, Laetitia; Bäck, Magnus; Arnaud, Claire; Rey, Amandine; Petri, Marcelo H; Levy, Patrick; Faure, Patrice; Stanke-Labesque, Françoise

2014-10-01

254

Poly-l-lactic acid/amorphous calcium phosphate bioabsorbable stent causes less inflammation than poly-l-lactic acid stent in coronary arteries  

PubMed Central

Aim: Poly-l-lactic acid (PLLA) based bioabsorbable stents with or without amorphous calcium phosphate (ACP) were implanted and compared the inflammation in coronary arteries. Methods: 6 PLLA and 6 PLLA/ACP based paclitaxel-eluting stents were randomly implanted into the coronary arteries of 12 healthy mini-pigs. The segments with stent were used to evaluate inflammation score and endothelialization score by hematoxylin-eosin staining. Results: At the 28th day after stent implantation, no in-stent restenosis or stent thrombosis was found in both PLLA and PLLA/ACP group. Histological analysis indicated that the inflammation score in PLLA/ACP group was less than that of in PLLA group (2.20±0.42 vs. 2.80±0.48, P<0.05). Consist with that, the expression of NF-?B was lower in PLLA/ACP group. The results from immunohistochemistry showed that the expressions of endothelial nitric oxide synthase (eNOS) and CD 31 in PLLA/ACP group were dramatically higher than those in PLLA group respectively. The serum levels of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in PLLA/ACP group were significantly higher than those in PLLA group respectively (509.86±49.37 pg/ml vs. 322.04±35.16 pg/ml and 139.46±7.52 ?mol/L vs. 29.55±16.55 ?mol/L, P<0.05). Conclusion: The application of ACP helps to reduce the inflammation caused by PLLA, and is also helpful in endothelial formation and function for PLLA-based bioabsorbable stent.

Kong, Lingting; Liu, Wenbo; Yan, Ge; Li, Qiang; Yang, Haiyan; Yu, Fengxia; Song, Haoming

2014-01-01

255

Molecular Pathways: Current Role and Future Directions of the Retinoic Acid Pathway In Cancer Prevention and Treatment  

PubMed Central

Retinoids and their naturally metabolized and synthetic products (e.g. all-trans retinoic acid, 13-cis retinoic acid, bexarotene) induce differentiation in various cell types. Retinoids exert their actions mainly through binding to the nuclear retinoic acid receptors (?, ?, ?), which are transcriptional and homeostatic regulators whose functions are often compromised early in neoplastic transformation. The retinoids have been investigated extensively for their utility in cancer prevention and treatment. Success has been achieved with their use in the treatment of subtypes of leukemia harboring chromosomal translocations. Promising results have been observed in the breast cancer prevention setting, where fenretinide prevention trials have provided a strong rationale for further investigation in young women at high-risk for breast cancer. Ongoing phase 3 randomized trials investigating retinoids in combination with chemotherapy in non-small cell lung cancer aim to definitively characterize the role of retinoids in this tumor type. The limited treatment success observed to date in the prevention and treatment of solid tumors may relate to the frequent epigenetic silencing of RAR?. Robust evaluation of RAR? and downstream genes may permit optimized use of retinoids in the solid tumor arena. PMID:23322901

Connolly, Roisin M.; Nguyen, Nguyen K.; Sukumar, Saraswati

2013-01-01

256

Long term higher urinary calcium excretion within the normal physiologic range predicts impaired bone status of the proximal radius in healthy children with higher potential renal acid load.  

PubMed

Reduced bone mineral density (BMD) and bone mass have been observed in children with idiopathic hypercalciuria. Whether urinary calcium excretion at the higher end of the normal physiologic range can influence bone health in healthy children independent of dietary intake is unknown. Urinary calcium was quantified in 603 24-h urine samples from 154 healthy children and adolescents who had ?3 urine collections and parallel 3-day weighed dietary records during the 4years preceding proximal forearm bone analyses by peripheral quantitative computed tomography (pQCT). Urinary potential renal acid load (uPRAL) was determined according to urine ionogram by subtracting measured quantitatively important mineral cations from nonbicarbonate anions. Urinary calcium excretion was significantly associated with volumetric (v)BMD (P=0.04), almost significantly with cortical bone mineral content (BMC) (P=0.05), but not with cortical cross-sectional area (CSA) (P=0.09), total CSA (P=0.3), or Strength-Strain Index (P=0.8) in the total population sample. Stratified analyses based on the median split of uPRAL showed that calcium excretion was negatively associated with vBMD (P=0.007), cortical BMC (P=0.001), and cortical CSA (P=0.004) in those children with higher uPRALs, but not in those with low uPRALs (P>0.3). In conclusion, long-term higher calciuria within the physiological range predicts reduced diaphyseal bone mass and bone density particularly in healthy children and adolescents with long-term unfavorable higher dietary acid load, i.e., with lower fruit and vegetable intake. PMID:22342797

Shi, Lijie; Libuda, Lars; Schönau, Eckhard; Frassetto, Lynda; Remer, Thomas

2012-05-01

257

Calcium oxalate stone and gout.  

PubMed

Gout is well known to be produced by increased uric acid level in blood. The objective of this paper is to assess the relationship between gout and calcium oxalate stone formation in the humans. 48 patients with combination of gout and calcium oxalate stone problem were included. The biochemical values of this group were compared with 38 randomly selected uric acid stone patients with gout, 43 stone patients with gout alone, 100 calcium oxalate stone patients without gout and 30 controls, making a total of 259 patients. Various biochemical parameters, namely serum calcium, phosphorus and uric acid and 24-h urine calcium, phosphorus, uric acid, oxalate, citrate and magnesium were analysed. ANOVA and Duncan's multiple-range tests were performed to assess statistical significance of the variations. The promoters of stone formation, namely serum calcium (P < 0.05), phosphorus (P < 0.05) and uric acid (P < 0.05) and urine calcium (P < 0.05), uric acid (P < 0.05) and oxalate (P < 0.05) were significantly variable in the different groups. The inhibitor citrate (P < 0.05) was also significantly variable. Multiple-range test showed that the promoters, namely serum calcium (P < 0.05) and urine uric acid (P < 0.05) were in a significantly higher range in the gouty patients, gouty uric acid stone patients and gouty calcium oxalate stone patients compared to the non-gouty patients and controls. Urine oxalate (P < 0.0001) was in the highest range in the gouty calcium oxalate or gouty uric acid stones patients. The inhibitor urine citrate (P < 0.001) was significantly lower in the gouty, gouty uric acid and gouty calcium oxalate patients. Serum uric acid was highest in the non-stone gouty patients, followed by the gouty uric acid stone formers and gouty calcium oxalate stone patients. The high values of promoters, namely uric acid and calcium in the gouty stone patients indicate the tendency for urinary stone formation in the gouty stone patients. There is probably a correlation between gout and calcium oxalate urinary stone. We presume this mechanism is achieved through the uric acid metabolism. The findings point to the summation effect of metabolic changes in development of stone disease. PMID:19779706

Marickar, Y M Fazil

2009-12-01

258

Use of caffeic acid phenethyl ester and cortisone may prevent proliferative vitreoretinopathy.  

PubMed Central

PURPOSE: To investigate whether caffeic acid phenethyl ester (CAPE) and cortisone prevent proliferative vitreoretinopathy (PVR). METHODS: Twenty pigmented rabbits were used in this study. All rabbits except controls received an intravitreal injection of 0.15 ml (75,000 U) of platelet-rich plasma into their left eye. The animals were divided into four groups: group I was treated with intraperitoneal injection of 0.5 ml (15 micromol/kg) of CAPE for 3 days, group II received 0.15 ml (4 mg/kg) of intravitreal cortisone, group III received nothing (blank group), and group IV (control group) received only 1 ml of 1% ethanol intraperitoneally daily for 3 days. Proliferative changes were graded in a masked fashion by indirect ophthalmoscopy for a 15-day follow-up period. The malondialdehyde (MDA), reduced glutathione (GSH) and total nitrite (NO) levels were measured in the vitreous humor. RESULTS: The grades of PVR were B-C in group I, and C-D in group II. The PVR grade in the control group was C-D. The mean MDA level in group I (4.0+/-0.8 micromol/l) was significantly lower than in the blank group (6.0 micromol/l) (p < 0.05). The mean GSH level in group I (71.0+/-11.2 micromol/l) was significantly different than in the blank group (p < 0.05). The MDA and GSH levels in group II were 4.7+/-0.6 micromol/l and 53.8+/-7.8 micromol/l, respectively. Both these levels were not significantly different from the blank group (p > 0.05). The NO levels in both treatment groups were significantly lower than in the blank group (p < 0.001). CONCLUSION: These findings suggest an inhibitory effect of CAPE on PVR. The inhibitory effect was supported by lower MDA and NO with higher GSH levels in treatment groups than in the blank group. There was no detected significant effect of cortisone for preventing PVR experimentally. PMID:15203555

Turkoz, Yusuf; Er, Hamdi; Borazan, Mehmet; Yilmaz, Harun; Mizrak, Bülent; Parlakpinar, Hakan; Cigremis, Yilmaz

2004-01-01

259

Calcium mobilisation and CCK secretion induced by modified fatty acids and latex microspheres reveal dual receptor mechanisms for lipid stimulation of STC-1 cells  

PubMed Central

How fatty acids stimulate enteroendocrine cells to release cholecystokinin (CCK) is largely unknown. Recently, we proposed that the murine enteroendocrine cell line, STC-1, responds to insoluble fatty acid aggregates rather than fatty acid monomers in solution. This hypothesis led to two testable predictions. First, other insoluble particles of similar size but unrelated to fatty acid may be able to stimulate STC-1 cells in a similar fashion to dodecanoic acid and second, fatty acid sensing in STC-1 cells should be fairly insensitive to chemical modifications of the fatty acid as long as these modifications do not greatly alter the ability of the molecule to form insoluble aggregates. We used several analogues of dodecanoic acid and several varieties of latex microsphere (varying in size and surface charge) to see whether the predictions of our model hold. We found that while there was at least one latex microsphere that could induce CCK secretion and calcium mobilisation in STC-1 cells, there was a very poor correlation between the presence of insoluble aggregates and a cellular response. Instead the most important property, determining the potency of fatty acid analogues as stimulants of CCK secretion, was their amphipathicity. Removal of either the polar head or lipophilic tail completely abolished the ability of a given fatty acid analogue to stimulate STC-1 cells. These data suggested that while fatty acids can stimulate cells as aggregates, they may also be acting in monomeric form with the oil:water partitioning coefficient playing a crucial role. We finally resolved this issue with the observation that the sulfate ion greatly altered the response of STC-1 cells to monomeric dodecanoic acid. In the presence of sulfate, STC-1 cells will only respond to dodecanoic acid aggregates whereas when sulfate is replaced with chloride the cells clearly respond to dodecanoic acid monomers which are completely in solution. In summary, we propose that dodecanoic acid can stimulate STC-1 cells via two separate pathways one involving fatty acid monomers in solution and one involving fatty acid aggregates. Which pathway dominates depends on the presence of sulfate in the extracellular medium. PMID:14555726

Kazmi, S; Sidhu, S S; Donohoe, T J; Wickham, M; Jones, M N; Thompson, D G; Case, R M; Benson, R S P

2003-01-01

260

Characterization of calcium carbonate/chitosan composites  

SciTech Connect

The crystal growth of calcium carbonate on a chitosan substrate was achieved using a supersaturated calcium carbonate solution, by using various additives, polyacrylic acid (PAA). Polyacrylic acid modified the chitosan-film surface and promoted the nucleation of calcium carbonate crystals.

Gonsalves, K.E.; Zhang, S. [Univ. of Connecticut, Storrs, CT (United States)

1995-12-31

261

21 CFR 184.1195 - Calcium citrate.  

Code of Federal Regulations, 2012 CFR

...Ca3 (C6 H5 O7 )2 ·4H2 O, CAS Reg. No. 813-0994-095) is the calcium salt of citric acid. It is prepared by neutralizing citric acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder...

2012-04-01

262

Daily calcium intake and physical activity status in urban women living on low incomes in Davao, Philippines: a primary study for osteoporosis prevention.  

PubMed

Low calcium intake and physical inactivity are modifiable risk factors of osteoporosis; however, little information is available about the prevalence of these risk factors among urban Filipino women living on low-incomes. The present study, therefore, investigated daily calcium intake, main calcium sources, and physical activity status in this population. The study group comprised healthy women aged in their 30 s who had participated in our previous survey using heel speed of sound (SOS) measurement in Davao, Philippines. The women were stratified into three groups based on SOS score and 20 were randomly selected from each, giving 60 in total. Calcium intake was measured by direct analysis of the food samples collected from 3-days 24 hour-food duplicate method. Physical activity was estimated based on pedometer determined walking steps over 5 days. The median [25%, 75%] calcium intake per day was 289 [225, 434] mg. Traditional foods derived from local small fish and plants were the main calcium sources. The median walking steps per day was 8750 [6920, 10836]. Although three groups did not show significantly different calcium intakes and walking steps, consumption of low-cost small fish and plant foods could be encouraged along with walking in urban Filipino women living on low-incomes. PMID:19763025

Miura, Shoko; Nakamori, Masayo; Yagi, Masumi; Saavedra, Ophelia L; Ikemoto, Shinji; Yamamoto, Shigeru

2009-08-01

263

5-Aminosalicylic acid prevents oxidant mediated damage of glyceraldehyde-3-phosphate dehydrogenase in colon epithelial cells  

PubMed Central

Background—Reactive oxygen and nitrogen derived species produced by activated neutrophils have been implicated in the damage of mucosal proteins including the inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in the active inflammatory lesion in patients with inflammatory bowel disease (IBD). This study investigated the efficacy of currently used IBD therapeutics to prevent injury mediated by reactive oxygen and nitrogen derived species. ?Methods—GAPDH activity of human colon epithelial cells was used as a sensitive indicator of injury produced by reactive oxygen and nitrogen derived species. HCT116 cells (106/ml phosphate buffered saline; 37°C) were incubated in the presence of 5-aminosalicylic acid (5-ASA), 6-mercaptopurine, methylprednisolone, or metronidazole before exposure to H2O2, HOCl, or NO in vitro. HCT116 cell GAPDH enzyme activity was determined by standard procedures. Cell free reactions between 5-ASA and HOCl were analysed by spectrophotometry and fluorimetry to characterise the mechanism of oxidant scavenging. ?Results—GAPDH activity of HCT116 cells was inhibited by the oxidants tested: the concentration that produced 50% inhibition (IC50) was 44.5 (2.1) µM for HOCl, 379.8 (21.3) µM for H2O2, and 685.8 (103.8) µM for NO (means (SEM)). 5-ASA was the only therapeutic compound tested to show efficacy (p<0.05) against HOCl mediated inhibition of enzyme activity; however, it was ineffective against H2O2 and NO mediated inhibition of GAPDH. Methylprednisolone, metronidazole, and the thiol-containing 6-mercaptopurine were ineffective against all oxidants. Studies at ratios of HOCl:5-ASA achievable in the mucosa showed direct scavenging to be the mechanism of protection of GAPDH activity. Mixing 5-ASA and HOCl before addition to the cells resulted in significantly greater protection of GAPDH activity than when HOCl was added to cells preincubated with 5-ASA. The addition of 5-ASA after HOCl exposure did not restore GAPDH activity. ?Conclusions—Therapies based on 5-ASA may play a direct role in scavenging the potent neutrophil oxidant HOCl, thereby protecting mucosal GAPDH from oxidative inhibition. These findings suggest that strategies for the further development of new HOCl scavenging compounds may be useful in the treatment of IBD. ?? Keywords: 5-aminosalicylic acid; 6-mercaptopurine; prednisolone; metronidazole; oxidants; glyceraldehyde-3-phosphate dehydrogenase PMID:9895376

McKenzie, S; Doe, W; Buffinton, G

1999-01-01

264

Effect of the addition of calcium soap to ewes' diet on fatty acid composition of ewe milk and subcutaneous fat of suckling lambs reared on ewe milk.  

PubMed

The aim of this work was to study the effect of the inclusion of calcium soap (CS) in ewes' diet on the fatty acid profile of suckling lambs. Sixty suckling lambs of three breeds (Castellana, Churra and Assaf) were divided into two equal groups. One group was fed with a diet composed of beetroot pulp, alfalfa, barley, corn, soy, cotton and 4% of CS, and the other with a control diet without CS. The fatty acid profiles of the ewe's milk samples collected on the day before slaughter and of the lamb subcutaneous fat collected from the back of the carcasses were analysed. The addition of calcium soap to the ewe's diet did not change the milk fatty acid profile but significantly increased SFA and decreased both the PUFA and MUFA levels of suckling lamb fat. PCA analysis revealed a good separation of the lamb samples according to the diet of the mothers, showing that diet is more important than breed in explaining sample variability. PMID:20374842

Lurueña-Martínez, M A; Palacios, C; Vivar-Quintana, A M; Revilla, I

2010-04-01

265

Antinociceptive effect of clavulanic acid and its preventive activity against development of morphine tolerance and dependence in animal models  

PubMed Central

Glutamate has a key role in pain perception and also development of tolerance and dependence to morphine. It has been reported that clavulanic acid affects glutamatergic transmission via activation of glutamate transporter. Therefore the present study was aimed to evaluate the possible antinociceptive effect of clavulanic acid and its preventive activity against development of morphine tolerance and dependence in animal models. Male Swiss mice (25-30 g) were used in this study. Acetic acid-induced writhing, formalin test and hot plate method were used to assess the antinociceptive effect of clavulanic acid. Morphine (30 mg/kg, s.c.) was administered to the mice two times a day (8 AM and 4 PM) for 3 days in order to produce tolerance. To develop morphine dependence, morphine sulfate (50, 50 and 75 mg/kg) was injected at 8 and 12 AM and 16 PM respectively and for 3 consecutive days. Naloxone (5 mg/kg, i.p) was used to induce morphine withdrawal syndrome and the number of jumps and presence of ptosis, piloerection, tremor, sniffing and diarrhea were recorded and compared with control group. Clavulanic acid at doses of 10, 20 and 40 mg/kg inhibited abdominal constriction and licking behavior of acetic acid and formalin-induced pain respectively. Clavulanic acid was not able to show any antinociception in hot plate model and could not prevent development of tolerance and dependence to morphine. Clavulanic acid has considerable antinociceptive activity and further studies are needed to clarify its exact mechanism. PMID:25657803

Hajhashemi, V.; Dehdashti, Kh.

2014-01-01

266

Caffeic acid phenethyl ester (CAPE) prevents inflammatory stress in organotypic hippocampal slice cultures.  

PubMed

Caffeic acid phenethyl ester (CAPE) is an antioxidant component of propolis, a natural product secreted by honeybee. Recent literature shows that CAPE inhibits nuclear factor kappa B (NFkappaB) activation in cell lines. Since NFkappaB was shown to be a crucial factor in neuroinflammation and to be associated with some neuropathologies, CAPE might reduce these disorders in brain too and have therapeutic applications. To test this hypothesis we used a model of endotoxic insult (interferon-gamma, followed by lipopolysaccharide) on rat organotypic hippocampal cultures. Cerebral inflammatory responses were strongly inhibited by CAPE (100 microM): reductions of NFkappaB nuclear activity, tumor necrosis factor alpha and nitric oxide productions were observed. At the dose of maximal effects (100 microM), an increase of cAMP-responsive element binding protein (CREB) activity, which anti-inflammatory role is well known, was seen. We compared CAPE effects with those of other drugs: anti-inflammatory as acetyl-salicylate and dexamethasone (glucocorticoid), antioxidant as pyrrolidine dithiocarbamate, or selective permeant inhibitor of NFkappaB as SN 50 peptide. These studies lead us to conclude that CAPE presents an interesting and original neuropharmacological profile compared to these drugs and might be helpful in the prevention of neurotoxic events due to excessive inflammatory reaction in brain. CAPE interferes with several effectors of neuroinflammation that might have complementary and synergic effects and allows a rather durable control since an acute treatment at the time of endotoxin exposure allows to control inflammatory factors for over 48 h. PMID:12877982

Montpied, Pascale; de Bock, Frédéric; Rondouin, Gérard; Niel, Gilles; Briant, Laurence; Courseau, Anne-Sophie; Lerner-Natoli, Mireille; Bockaert, Joël

2003-07-23

267

Interactions of calcium ions with weakly acidic active ingredients slow cuticular penetration: a case study with glyphosate.  

PubMed

Potassium and calcium salts of glyphosate were obtained by titrating glyphosate acid with the respective bases to pH 4.0, and rates of penetration of these salts across isolated astomatous cuticular membranes (CMs) were measured at 20 degrees C and 70, 80, 90, and 100% humidity. K-glyphosate exhibited first-order penetration kinetics, and rate constants (k) increased with increasing humidity. Ca-glyphosate penetrated only when the humidity above the salt residue was 100%. At 90% humidity and below, Ca-glyphosate formed a solid residue on the CMs and penetration was not measurable. With Ca-glyphosate, the k value at 100% humidity decreased with time and the initial rates were lower than for K-glyphosate by a factor of 3.68. After equimolar concentrations of ammonium oxalate were added to Ca-glyphosate, high penetration rates close to those measured with K-glyphosate were measured at all humidities. Adding ammonium sulfate or potassium carbonate also increased rates between 70 and 100% humidity, but they were not as high as with ammonium oxalate. The data indicate that at pH 4.0 one Ca2+ ion is bound to two glyphosate anions. This salt has its deliquescence point near 100% humidity. Therefore, it is a solid at lower humidity and does not penetrate. Its molecular weight is 1.82 times larger than that of K-glyphosate, and this greatly slows down rates of penetration, even at 100% humidity. The additives tested have low solubility products and form insoluble precipitates with Ca2+ ions, but only ammonium oxalate binds Ca2+ quantitatively. The resulting ammonium salt of glyphosate penetrates at 70-100% humidity and at rates comparable to K-glyphosate. The results contribute to a better understanding of the hard water antagonism observed with glyphosate. It is argued that other pesticides and hormones with carboxyl functions are likely to respond to Ca2+ ions in a similar fashion. In all of these cases, ammonium oxalate is expected to overcome hard water antagonism. PMID:15479021

Schönherr, Jörg; Schreiber, Lukas

2004-10-20

268

Nitric oxide-activated calcium/calmodulin-dependent protein kinase regulates the abscisic acid-induced antioxidant defence in maize  

PubMed Central

Nitric oxide (NO), hydrogen peroxide (H2O2), and calcium (Ca2+)/calmodulin (CaM) are all required for abscisic acid (ABA)-induced antioxidant defence. Ca2+/CaM-dependent protein kinase (CCaMK) is a strong candidate for the decoder of Ca2+ signals. However, whether CCaMK is involved in ABA-induced antioxidant defence is unknown. The results of the present study show that exogenous and endogenous ABA induced increases in the activity of ZmCCaMK and the expression of ZmCCaMK in leaves of maize. Subcellular localization analysis showed that ZmCCaMK is located in the nucleus, the cytoplasm, and the plasma membrane. The transient expression of ZmCCaMK and the RNA interference (RNAi) silencing of ZmCCaMK analysis in maize protoplasts revealed that ZmCCaMK is required for ABA-induced antioxidant defence. Moreover, treatment with the NO donor sodium nitroprusside (SNP) induced the activation of ZmCCaMK and the expression of ZmCCaMK. Pre-treatments with an NO scavenger and inhibitor blocked the ABA-induced increases in the activity and the transcript level of ZmCCaMK. Conversely, RNAi silencing of ZmCCaMK in maize protoplasts did not affect the ABA-induced NO production, which was further confirmed using a mutant of OsCCaMK, the homologous gene of ZmCCaMK in rice. Moreover, H2O2 was also required for the ABA activation of ZmCCaMK, and pre-treatments with an NO scavenger and inhibitor inhibited the H2O2-induced increase in the activity of ZmCCaMK. Taken together, the data clearly suggest that ZmCCaMK is required for ABA-induced antioxidant defence, and H2O2-dependent NO production plays an important role in the ABA-induced activation of ZmCCaMK. PMID:22865912

Zhang, Aying; Jiang, Mingyi

2012-01-01

269

Cloning of a new cation ATPase from Plasmodium falciparum: conservation of critical amino acids involved in calcium binding in mammalian organellar Ca(2+)-ATPases.  

PubMed

In order to study molecules that may be involved in pH gradient formation in Plasmodium, we have identified a novel cation-translocating ATPase (P-type ATPase) gene from P. falciparum (Pf). We report the full-length nucleotide and deduced amino acid (aa) sequences of this gene that we called PfATPase4. The PfATPase4 protein shares features with the different members of eukaryotic P-type ATPases, such as a similar transmembrane (TM) organization and aa identity in functionally important regions. Interestingly, the PfATPase4 protein possesses conserved aa involved in calcium binding in mammalian organellar Ca(2+)-ATPases. PMID:7789797

Trottein, F; Thompson, J; Cowman, A F

1995-05-26

270

Effects of supplementing with calcium salts of palm oil fatty acids or hydrogenated tallow on ewe milk production and twin lamb growth.  

PubMed

Two experiments were conducted with Polypay ewes nursing twin lambs to evaluate the effects of supplementing fat (calcium salts of palm oil fatty acids or hydrogenated tallow) on ewe lactation. In Exp. 1, ewes were fed a 52% concentrate:48% hay-based diet (as-fed basis) consisting of alfalfa hay (n = 4), endophyte-free fescue hay (n = 4), or fescue hay with 3.7% fatty acids (n = 4) from d 4 to 56 of lactation. In Exp. 2, ewes were fed similar diets that had endophyte-free fescue hay (n = 6), fescue hay with 3.7% fatty acids (n = 5), or fescue hay with 3.1% tallow (n = 6) from d 14 before lambing until d 57 of lactation. Diet formulations with supplemental fat were more nutrient dense, and treatments were fed to meet ewe nutrient requirements; this caused diets with added fat to be offered at 10 and 17% lower rates than unsupplemented diets in Exp. 1 and 2, respectively. Lambs were maintained to consume only ewe milk. Ewe milk production and composition were determined using a portable milking machine following a 3-h separation from lambs. In Exp. 1, milk fat content was increased (P < 0.01) when ewes consumed fescue hay with fatty acids vs. the fescue hay diet (11.4 vs. 8.3%). Ewes fed fescue hay with fatty acids lost the most (P < 0.05) weight over lactation (-8.6 kg) compared with ewes fed the alfalfa hay (-2.4 kg) and fescue hay (-3.8 kg) diets. Other milk measures, lamb gain, and production efficiencies were not changed. In Exp. 2, ewes supplemented with fatty acids produced more (P < 0.05) milk fat than those fed tallow (290 vs. 210 g/d). The proportion of synthesized milk fat 14:0 was decreased (P < 0.01), but the percentage of incorporated 16:0 increased (P < 0.05) when fatty acids were fed. Dietary fat digestibility by ewes was increased (P < 0.01) by fatty acid supplementation but decreased (P < 0.01) when tallow was added. Although ewe weight measures were not changed in Exp. 2, twin lamb gain per ewe organic matter intake was most efficient (P < 0.05) when ewes were supplemented with fatty acids. Results suggest that feeding hydrogenated tallow decreased nutrient availability for ewe milk fat production. A complete diet based on endophyte-free fescue hay can replace a traditional alfalfa hay diet, whereas supplementing with the calcium salts of palm oil fatty acids may be more feasible when energy is limiting during ewe lactation. PMID:15446495

Appeddu, L A; Ely, D G; Aaron, D K; Deweese, W P; Fink, E

2004-09-01

271

Folate Deficiency and Folic Acid Supplementation: The Prevention of Neural-Tube Defects and Congenital Heart Defects  

PubMed Central

Diet, particularly vitamin deficiency, is associated with the risk of birth defects. The aim of this review paper is to show the characteristics of common and severe neural-tube defects together with congenital heart defects (CHD) as vitamin deficiencies play a role in their origin. The findings of the Hungarian intervention (randomized double-blind and cohort controlled) trials indicated that periconceptional folic acid (FA)-containing multivitamin supplementation prevented the major proportion (about 90%) of neural-tube defects (NTD) as well as a certain proportion (about 40%) of congenital heart defects. Finally the benefits and drawbacks of three main practical applications of folic acid/multivitamin treatment such as (i) dietary intake; (ii) periconceptional supplementation; and (iii) flour fortification are discussed. The conclusion arrived at is indeed confirmation of Benjamin Franklin’s statement: “An ounce of prevention is better than a pound of care”. PMID:24284617

Czeizel, Andrew E.; Dudás, Istvan; Vereczkey, Attila; Bánhidy, Ferenc

2013-01-01

272

Ferulic acid prevents the injury-induced decrease of ?-enolase expression in brain tissue and HT22 cells  

PubMed Central

Ferulic acid is known to act as a protective agent in cerebral ischemia through its anti-oxidant activity. ?-Enolase is a neuron-specific enolase that also exerts a neuroprotective effect. Here, we investigated whether ferulic acid regulates the expression level of ?-enolase in middle cerebral artery occlusion (MCAO)-induced brain injury and glutamate exposure-induced neuronal cell death. Adult male rats were treated with either vehicle or ferulic acid (100 mg/kg, i.v.) after MCAO and cerebral cortex tissues were collected 24 h after MCAO. Using a proteomics approach, we found that ?-enolase expression was decreased in MCAO-injured animals treated with vehicle alone, whereas ferulic acid treatment attenuated this decrease. Reverse-transcription PCR and Western blot analyses confirmed that ferulic acid treatment prevented MCAO injury-induced decrease in ?-enolase. Furthermore, in hippocampal-derived cell lines, glutamate exposure also decreased ?-enolase expression and ferulic acid treatment attenuated this glutamate-induced decrease in ?-enolase. These findings suggest that ferulic acid mediates a neuroprotective effect by attenuating injury-induced decreases of ?-enolase expression in neuronal cells. PMID:24707299

Gim, Sang-A

2014-01-01

273

Ferulic acid prevents the injury-induced decrease of ?-enolase expression in brain tissue and HT22 cells.  

PubMed

Ferulic acid is known to act as a protective agent in cerebral ischemia through its anti-oxidant activity. ?-Enolase is a neuron-specific enolase that also exerts a neuroprotective effect. Here, we investigated whether ferulic acid regulates the expression level of ?-enolase in middle cerebral artery occlusion (MCAO)-induced brain injury and glutamate exposure-induced neuronal cell death. Adult male rats were treated with either vehicle or ferulic acid (100 mg/kg, i.v.) after MCAO and cerebral cortex tissues were collected 24 h after MCAO. Using a proteomics approach, we found that ?-enolase expression was decreased in MCAO-injured animals treated with vehicle alone, whereas ferulic acid treatment attenuated this decrease. Reverse-transcription PCR and Western blot analyses confirmed that ferulic acid treatment prevented MCAO injury-induced decrease in ?-enolase. Furthermore, in hippocampal-derived cell lines, glutamate exposure also decreased ?-enolase expression and ferulic acid treatment attenuated this glutamate-induced decrease in ?-enolase. These findings suggest that ferulic acid mediates a neuroprotective effect by attenuating injury-induced decreases of ?-enolase expression in neuronal cells. PMID:24707299

Gim, Sang-A; Koh, Phil-Ok

2014-03-01

274

Effect of calcium salts of a mixture of conjugated linoleic acids containing trans-10, cis-12 in the diet on milk fat synthesis in goats.  

PubMed

Dietary supplements of conjugated linoleic acid (CLA) containing trans-10, cis-12 CLA decrease milk fat secretion in the lactating cow and sheep, but their effects on mammary lipogenesis in the goat are less well defined. Eight lactating goats were used in two 4 x 4 Latin-square experiments with 14 d experimental periods to examine the effects of calcium salts of CLA methyl esters (CaCLA) containing trans-10, cis-12 on milk fat synthesis. Experimental treatments consisted of incremental inclusion of 0, 30, 60 or 90 g of CaCLA/d (corresponding to 7.47, 14.9 and 22.4 g/d of trans-10, cis-12 CLA) offered during the first 10 d of each experimental period that replaced maize grain in concentrates (Experiment 1) or calcium salts of palm oil fatty acids (Experiment 2). Relative to the control, inclusion of 30, 60 or 90 g CaCLA/d in the diet reduced milk fat yield by 19.8, 27.9 and 32.3 % and 17.5, 39.0 and 49.3 % in Experiments 1 and 2, respectively. Decreases in milk fat were due to reductions in the secretion of fatty acids synthesised de novo rather than the uptake of fatty acids from the peripheral circulation. Indirect comparisons with the studies in the lactating cow indicated a lower efficacy of CaCLA supplements on mammary lipogenesis in the goat. In conclusion, CaCLA in the diet inhibits milk fat synthesis in the goat, responses that are dependent on the supply of dietary fatty acids, with evidence that the caprine is less sensitive to the anti-lipogenic effects of trans-10, cis-12 CLA compared with the bovine or ovine. PMID:18814802

Shingfield, Kevin J; Rouel, Jacques; Chilliard, Yves

2009-04-01

275

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2010 CFR

...Calcium glycerophosphate (C3 H7 CaO6 P, CAS Reg. No. 27214-00-2) is a fine, white, odorless, almost tasteless, slightly hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or...

2010-04-01

276

21 CFR 184.1212 - Calcium pantothenate.  

Code of Federal Regulations, 2010 CFR

...vitamins of the B complex. Only the D- isomer of pantothenic acid has vitamin activity, although both the D- isomer and the DL- racemic mixture of calcium pantothenate are used in food. Commercial calcium pantothenate is prepared synthetically...

2010-04-01

277

?-Aminobutyric Acid Type B (GABAB) Receptor Expression Is Needed for Inhibition of N-type (Cav2.2) Calcium Channels by Analgesic ?-Conotoxins*  

PubMed Central

?-Conotoxins Vc1.1 and RgIA are small peptides isolated from the venom of marine cone snails. They have effective anti-nociceptive actions in rat models of neuropathic pain. Pharmacological studies in rodent dorsal root ganglion (DRG) show their analgesic effect is mediated by inhibition of N-type (Cav2.2) calcium channels via a pathway involving ?-aminobutyric acid type B (GABAB) receptor. However, there is no direct demonstration that functional GABAB receptors are needed for inhibition of the Cav2.2 channel by analgesic ?-conotoxins. This study examined the effect of the GABAB agonist baclofen and ?-conotoxins Vc1.1 and RgIA on calcium channel currents after transient knockdown of the GABAB receptor using RNA interference. Isolated rat DRG neurons were transfected with small interfering RNAs (siRNA) targeting GABAB subunits R1 and R2. Efficient knockdown of GABAB receptor expression at mRNA and protein levels was confirmed by quantitative real time PCR (qRT-PCR) and immunocytochemical analysis, respectively. Whole-cell patch clamp recordings conducted 2–4 days after transfection showed that inhibition of N-type calcium channels in response to baclofen, Vc1.1 and RgIA was significantly reduced in GABAB receptor knockdown DRG neurons. In contrast, neurons transfected with a scrambled nontargeting siRNA were indistinguishable from untransfected neurons. In the HEK 293 cell heterologous expression system, Vc1.1 and RgIA inhibition of Cav2.2 channels needed functional expression of both human GABAB receptor subunits. Together, these results confirm that GABAB receptors must be activated for the modulation of N-type (Cav2.2) calcium channels by analgesic ?-conotoxins Vc1.1 and RgIA. PMID:22613715

Cuny, Hartmut; de Faoite, Andrew; Huynh, Thuan G.; Yasuda, Takahiro; Berecki, Géza; Adams, David J.

2012-01-01

278

Effect of timing and duration of dietary conjugated linoleic acid on mammary cancer prevention  

Microsoft Academic Search

Conjugated linoleic acid (CLA) is a minor fatty acid found predominantly in the form of triglycerides in beef and dairy products. Previous work by Ip and co?workers showed that free fatty acid?CLA at ?1% in the diet is protective against mammary carcinogenesis in rats. The present study verified that the anticancer activities of free fatty acid?CLA and triglyceride?CLA are essentially

Clement Ip; Joseph A. Scimeca; Henry Thompson

1995-01-01

279

40 CFR 721.2076 - D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...  

Code of Federal Regulations, 2012 CFR

...acetate, calcium magnesium potassium sodium salt. 721.2076 Section 721.2076 Protection...acetate, calcium magnesium potassium sodium salt. (a) Chemical substance and significant...acetate, calcium magnesium potassium sodium salt (PMN P-00-7; CAS...

2012-07-01

280

Calcium signaling in neuronal cells exposed to the munitions compound Cyclotrimethylenetrinitramine (RDX).  

PubMed

Cyclotrimethylenetrinitramine (RDX) has been used extensively as an explosive in military munitions. Mechanisms for seizure production, seen in past animal studies, have not been described. Increased calcium levels contribute to excitotoxicity, so in this study neuroblastoma cells are loaded with calcium-indicating dye before application of 1.5 microM to 7.5 mM RDX, with fluorescence recorded for 30 cycles of 11 seconds each. The lowest concentration of RDX increases calcium fluorescence significantly above baseline for cycles 2 to 8; millimolar concentrations increase calcium fluorescence significantly above baseline for cycles 2 to 30. Increases in calcium, like those of 200 nM carbachol, are prevented with 10 mM of calcium chelator ethylene glycol-bis(beta-aminoethyl ether)-N,N,N,N tetra-acetic acid (EGTA, tetrasodium salt). Calcium channel blocker verapamil (20 microM), Ca(2+)-ATPase inhibitor thapsigargin (5 microM), and general membrane stabilizer lidocaine (10 mM) partially attenuate carbachol- and RDX-induced increases in calcium, suggesting that RDX transiently increases intracellular calcium by multiple mechanisms. PMID:19652196

Ehrich, Marion; Wu, Xiaohua; Werre, Stephen R; Major, Michael A; McCain, Wilfred C; Reddy, Gunda

2009-01-01

281

Effect of Supplementation with Calcium Salts of Fish Oil on n-3 Fatty Acids in Milk Fat1  

Microsoft Academic Search

Enrichment of milk fat with n-3 fatty acids, in partic- ular eicosapentaenoic acid (EPA) and docosahexaenoic acid(DHA),maybeadvantageousbecauseoftheirbene- ficial effects on human health. In addition, these fatty acids play an important role in reproductive processes in dairy cows. Our objective was to evaluate the protec- tion of EPA and DHA against rumen biohydrogenation provided by Ca salts of fish oil. Four

E. Castañeda-Gutiérrez; M. J. de Veth; A. L. Lock; D. A. Dwyer; K. D. Murphy; D. E. Bauman

2007-01-01

282

Milk composition, milk fatty acid profile, digestion, and ruminal fermentation in dairy cows fed whole flaxseed and calcium salts of flaxseed oil.  

PubMed

Four ruminally lactating Holstein cows averaging 602+/-25 kg of body weight and 64+/-6 d in milk at the beginning of the experiment were randomly assigned to a 4 x 4 Latin square design to determine the effects of feeding whole flaxseed and calcium salts of flaxseed oil on dry matter intake, digestibility, ruminal fermentation, milk production and composition, and milk fatty acid profile. The treatments were a control with no flaxseed products (CON) or a diet (on a dry matter basis) of 4.2% whole flaxseed (FLA), 1.9% calcium salts of flaxseed oil (SAL), or 2.3% whole flaxseed and 0.8% calcium salts of flaxseed oil (MIX). The 4 isonitrogenous and isoenergetic diets were fed for ad libitum intake. Experimental periods consisted of 21 d of diet adaptation and 7 d of data collection and sampling. Dry matter intake, digestibility, milk production, and milk concentrations of protein, lactose, urea N, and total solids did not differ among treatments. Ruminal pH was reduced for cows fed the CON diet compared with those fed the SAL diet. Propionate proportion was higher in ruminal fluid of cows fed CON than in that of those fed SAL, and cows fed the SAL and CON diets had ruminal propionate concentrations similar to those of cows fed the FLA and MIX diets. Butyrate concentration was numerically higher for cows fed the SAL diet compared with those fed the FLA diet. Milk fat concentration was lower for cows fed SAL than for those fed CON, and there was no difference between cows fed CON and those fed FLA and MIX. Milk yields of protein, fat, lactose, and total solids were similar among treatments. Concentrations of cis-9 18:1 and of intermediates of ruminal biohydrogenation of fatty acids such as trans-9 18:1 were higher in milk fat of cows fed SAL and MIX than for those fed the CON diet. Concentration of rumenic acid (cis-9, trans-11 18:2) in milk fat was increased by 63% when feeding SAL compared with FLA. Concentration of alpha-linolenic acid was higher in milk fat of cows fed SAL and MIX than in milk of cows fed CON (75 and 61%, respectively), whereas there was no difference between FLA and CON. Flaxseed products (FLA, SAL, and MIX diets) decreased the n-6 to n-3 fatty acid ratio in milk fat. Results confirm that flax products supplying 0.7 to 1.4% supplemental fat in the diet can slightly improve the nutritive value of milk fat for better human health. PMID:20630232

Côrtes, C; da Silva-Kazama, D C; Kazama, R; Gagnon, N; Benchaar, C; Santos, G T D; Zeoula, L M; Petit, H V

2010-07-01

283

Potential preventive role of lactic acid bacteria against Aflatoxin M1 immunotoxicity and genotoxicity in mice.  

PubMed

Abstract Aflatoxin M1 (AFM1) is a mycotoxin produced by numerous Aspergillus species in pre- or post-harvest cereals and milk. Exposure to AFM1 imparts potent economic losses in the livestock industry. Toxicologically, it also causes severe immune system problems. The aims of this study were to evaluate a new AFM1-binding/degrading microorganism for biologic detoxification, to examine its ability to degrade AFM1 in liquid medium, and to evaluate its potential for in vivo preventative effects against AFM1-induced immunotoxicity and genotoxicity in mice. Lactobacillus plantarum MON03 (LP) isolated from Tunisian artisanal butter was found to display significant binding ability to AFM1 in PBS (93%) within 24?h of incubation. Further, the LP was able to tolerate gastric acidity, bile salts, and adhere efficiently to Caco-3 cells in vitro. The in vivo study used Balb/c mice that received either vehicle (control), LP only (at 1?×?10(9?)CFU/L, ?1?mg/kg bw), AFM1 (100?mg/kg bw), or AFM1?+?LP daily for 15 days (by gavage); two other groups received a single dose of colchicine (4?mg/kg) or mitomycin C (1?mg/kg) as positive controls for induction of micronuclei and chromosomal aberrations, respectively. The results showed that, compared to in control mice, AFM1 treatment led to significantly decreased body weight gains, and caused cytotoxic/genotoxic effects as indicated by increases in frequencies of polychromatic erythrocytes, as well as those with micronucleation (PCEMN) and chromosomal aberrations, among bone marrow cells. The concurrent administration of LP with AFM1 strongly reduced the adverse effects of AFM1 on each parameter. Mice receiving AFM1?+?LP co-treatment displayed no significant differences in the assayed parameters as compared to the control mice. By itself, the bacteria caused no adverse effects. Based on the data, it is concluded that the test bacteria could potentially be beneficial in the detoxification of AFM1-contaminated foods and feeds for humans and animals. PMID:24738739

Ben Salah-Abbès, Jalila; Abbès, Samir; Jebali, Rania; Haous, Zohra; Oueslati, Ridha

2015-04-01

284

Multi-element analysis of milk by ICP-oa-TOF-MS after precipitation of calcium and proteins by oxalic and nitric acid.  

PubMed

In this work a simple technique employing oxalic and nitric acid to cow's milk samples prior to analysis by inductively coupled plasma orthogonal acceleration time-of-flight mass spectrometry (ICP-oa-TOF-MS) was introduced. After the precipitation of calcium and proteins via oxalic and nitric acid, respectively, the resulting liquid phase was aspirated with a concentric glass nebulizer for ICP-TOF-MS determination of trace elements. Precipitation of proteins is essential for better separation of solid and liquid phase of modified samples. Separation of calcium as a precipitated non-soluble oxalate enables the elimination of spectral interferences originating from different calcium containing species like (40)Ca(35)Cl(+), (40)Ca(37)Cl(+), (43)Ca(16)O(+), (40)Ca(18)O(+), (44)Ca(16)O(+), (43)Ca(16)O(1)H(+) onto the determination of As, Se, Co and Ni whose assay is more difficult when using conventional quadrupole instruments. High detection capability is further an advantage as the approach enables the analysis without dilution. The methodology may serve, in addition, for a fast and sensitive determination of some other elements. After that, direct, reliable and simultaneous determination of 16 elements (Li, Be, B, V, Cr, Mn, Ni, Co, Ga, As, Se, Mo, Sn, Sb, Cs, Tl) at trace and ultra-trace levels in milk can be performed under optimum instrumental conditions and by using Rh as an internal standard. Accuracy and precision was assessed by measuring NCS ZC73015 milk powder control standard, yielding results in agreement with certified values and RSD <10%. The accuracy was also checked by comparison of the results of the proposed method with those found by a method based on a microwave-assisted digestion of real samples. PMID:23598096

Husáková, Lenka; Urbanová, Iva; Šrámková, Jitka; Kone?ná, Michaela; Bohuslavová, Jana

2013-03-15

285

Molecular Cell Calcium Blocks Formation of Apoptosome  

E-print Network

Molecular Cell Article Calcium Blocks Formation of Apoptosome by Preventing Nucleotide Exchange in the monomeric, autoinhibited Apaf-1 protein. Con- sequently, calcium blocks the ability of Apaf-1 to activate caspase-9. These observations sug- gest an important role of calcium homeostasis on the Apaf-1-dependent

Rabinowitz, Joshua D.

286

Black Tea May Be a Prospective Adjunct for Calcium Supplementation to Prevent Early Menopausal Bone Loss in a Rat Model of Osteoporosis  

PubMed Central

The present study was undertaken to find out the ability of black tea extract (BTE) as a suitable alternative of adjunct for calcium supplementation in treating an ovariectomized rat model of early osteoporosis. Female Wistar rats weighing 140–150?g were divided into four groups consisting of six animals in each group: (A) sham-operated control; (B) bilaterally ovariectomized; (C) bilaterally ovariectomized + BTE; (D) bilaterally ovariectomized + 17?-estradiol. Results suggest that BTE could promote intestinal absorption of calcium significantly (P < 0.01 for duodenum and ileum; and P < 0.05 for jejunum). This was found associated with enhanced activities of two relevant intestinal mucosal enzymes alkaline phosphatase (P < 0.01 for duodenum, jejunum, and ileum) and Ca2+ activated ATPase (P < 0.01 for duodenum, jejunum, and ileum). Such BTE-mediated promotion of calcium absorption was coupled with increase in serum estrogen titer (P < 0.01) and recovery of all urinary, bone, and serum osteoporotic marker parameters, including bone histological features. Serum parathyroid hormone level, however, was not altered in these animals (P > 0.05). A comparative study with 17?-estradiol, a well-known adjunct for calcium supplementation, indicated that efficacy of BTE in maintaining skeletal health is close to that of 17?-estradiol. This study suggests that simultaneous use of BTE is promising as a prospective candidate for adjunctive therapies for calcium supplementation in the early stage of menopausal bone changes. PMID:23984184

Das, Asankur Sekhar; Banerjee, Maitrayee; Das, Dolan; Mukherjee, Sandip; Mitra, Chandan

2013-01-01

287

Preferential affinity of calcium ions to charged phosphatidic-acid surface from a mixed calcium/barium solution: X-ray reflectivity and fluorescence studies  

E-print Network

X-ray reflectivity and fluorescence near total reflection experiments were performed to examine the affinities of divalent ions ($\\mathrm{Ca^{2+}}$ and $\\mathrm{Ba^{2+}}$) from aqueous solution to a charged phosphatidic-acid (PA) surface. A phospholipid (1,2-Dimyristoyl-sn-Glycero-3-Phosphate, DMPA), spread as a monolayer at the air/water interface, was used to form and control the charge density at the interface. We find that for solutions of the pure salts (i.e., $\\mathrm{CaCl_{2}}$ and $\\mathrm{BaCl_{2}}$), the number of bound ions per DMPA at the interface is saturated at concentrations that exceed $\\mathrm{10^{-3}M}$. For a 1:1 $\\mathrm{Ca^{2+}/Ba^{2+}}$ mixed solutions, we find that the bound $\\mathrm{Ca^{2+}/Ba^{2+}}$ ratio at the interface is 4:1. If the only property determining charge accumulation near PA were the ionic charges, the concentration of mixed $\\mathrm{Ca^{2+}/Ba^{2+}}$ at the interface would equal that of the bulk. Our results show a clear specific affinity of PA for Ca compared to Ba. We provide some discussion on this issues as well as some implications for biological systems. Although our results indicate an excess of counterion charge with respect to the surface charge, that is, charge inversion, the analysis of both reflectivity and fluorescence do not reveal excess of co-ions (namely, $\\mathrm{Cl^{-}}$ or $\\mathrm{I}^{-}$).

Wei Bu; Kevin Flores; Jacob Pleasants; David Vaknin

2009-01-16

288

Kidney and Calcium Homeostasis  

PubMed Central

Plasma calcium concentration is maintained within a narrow range (8.5-10.5 mg/dL) by the coordinated action of parathyroid hormone (PTH), 1,25(OH)2D3, calcitonin, and ionized calcium (iCa2+) itself. The kidney plays a key role in this process by the fine regulation of calcium excretion. More than 95% of filtered calcium is reabsorbed along the renal tubules. In the proximal tubules, 60% of filtered calcium is reabsorbed by passive mechanisms. In the thick ascending limb, 15% of calcium is reabsorbed by paracellular diffusion through paracellin-1 (claudin-16). The calcium sensing receptor (CaSR) in the basolateral membrane of the thick ascending limb senses the change in iCa2+ and inhibits calcium reabsorption independent to PTH and 1,25(OH)2D3. The fine regulation of calcium excretion occurs in the distal convoluted tubules and connecting tubules despite the fact that only 10-15% of filtered calcium is reabsorbed there. Transient receptor potential vanilloid 5 (TRPV5) and 6 (TRPV6) in the apical membrane act as the main portal of entry, calbindin-D28K delivers Ca2+ in the cytoplasm, and then Na2+/Ca2+ exchanger (NCX1) and plasma membrane Ca2+-ATPase in the basolateral membrane serve as an exit. In the cortical collecting duct, TRPV6 is expressed, but the role might be negligible. In addition to PTH and 1,25(OH)2D3, acid-base disturbance, diuretics, and estrogen affect on these calcium channels. Recently, klotho and fibroblast growth factor 23 (FGF23) are suggested as new players in the calcium metabolism. Klotho is exclusively expressed in the kidney and co-localized with TRPV5, NCX1, and calbindin-D28K. Klotho increases calcium reabsorption through trafficking of TRPV5 to the plasma membrane, and also converts FGF receptor to the specific FGF23 receptor. FGF23:klotho complex bound to FGF receptor inhibits 1?-hydroxylase of vitamin D, and contributes to calcium reabsorption and phosphate excretion in the kidney. PMID:24459525

2008-01-01

289

Combinatorial chemopreventive effect of butyric acid, nicotinamide and calcium glucarate against the 7,12-dimethylbenz(a)anthracene induced mouse skin tumorigenesis attained by enhancing the induction of intrinsic apoptotic events.  

PubMed

We explored the basis of the combinatorial chemopreventive effect of butyric acid (BA), nicotinamide (NA) and calcium glucarate (CAG) on mouse skin exposed to 7,12-dimethylbenz(a)anthracene (DMBA). We studied the effects of topical application of DMBA in the presence or absence of BA, NA and CAG on the regulators of apoptosis. DMBA treatment suppressed Bax, Bax/Bcl-2 ratio, release of cyt c, Apaf1, caspase-9, -3 mediated apoptosis. Downregulation of p21 and upregulation of Bcl-2, mut p53 were also observed in only DMBA treated mice. Simultaneous application of BA, NA and CAG induced a mitochondria-mediated apoptosis, characterized by a rise in the Bax, Bax/Bcl-2 ratio, release of cyt c, upregulation of Apaf1 with down-stream activation of caspase-9, -3. Furthermore treatment with BA, NA and CAG demonstrated an upregulation of p21 and downregulation of Bcl-2, mut p53. But this effect was enhanced in the presence of all the three compounds together in combination. Chemoprevention by a combination of BA, NA and CAG by inducing the apoptosis, the natural cell death, suggest the importance of the potential combinational strategies capable of preventing skin tumor development. PMID:25478867

Tiwari, Prakash; Sahay, Satya; Pandey, Manuraj; Qadri, Syed S Y H; Gupta, Krishna P

2015-01-25

290

Updated estimates of neural tube defects prevented by mandatory folic Acid fortification - United States, 1995-2011.  

PubMed

In 1992, the U.S. Public Health Service recommended that all women capable of becoming pregnant consume 400 µg of folic acid daily to prevent neural tube defects (NTDs). NTDs are major birth defects of the brain and spine that occur early in pregnancy as a result of improper closure of the embryonic neural tube, which can lead to death or varying degrees of disability. The two most common NTDs are anencephaly and spina bifida. Beginning in 1998, the United States mandated fortification of enriched cereal grain products with 140 µg of folic acid per 100 g. Immediately after mandatory fortification, the birth prevalence of NTD cases declined. Fortification was estimated to avert approximately 1,000 NTD-affected pregnancies annually. To provide updated estimates of the birth prevalence of NTDs in the period after introduction of mandatory folic acid fortification (i.e., the post-fortification period), data from 19 population-based birth defects surveillance programs in the United States, covering the years 1999-2011, were examined. After the initial decrease, NTD birth prevalence during the post-fortification period has remained relatively stable. The number of births occurring annually without NTDs that would otherwise have been affected is approximately 1,326 (95% confidence interval = 1,122-1,531). Mandatory folic acid fortification remains an effective public health intervention. There remain opportunities for prevention among women with lower folic acid intakes, especially among Hispanic women, to further reduce the prevalence of NTDs in the United States. PMID:25590678

Williams, Jennifer; Mai, Cara T; Mulinare, Joe; Isenburg, Jennifer; Flood, Timothy J; Ethen, Mary; Frohnert, Barbara; Kirby, Russell S

2015-01-16

291

A full-scale porous reactive wall for prevention of acid mine drainage  

Microsoft Academic Search

The generation and release of acidic drainage containing high concentrations of dissolved metals from decommissioned mine wastes is an environmental problem of international scale. A potential solution to many acid drainage problems is the installation of permeable reactive walls into aquifers affected by drainage water derived from mine waste materials. A permeable reactive wall installed into an aquifer impacted by

Shawn G. Benner; David W. Blowes; Carol J. Ptacek

1997-01-01

292

Effect of replacing calcium salts of palm oil distillate with extruded linseeds on milk fatty acid composition in Jersey and Holstein cows.  

PubMed

Clinical and biomedical studies have provided evidence for the critical role of n-3 fatty acids on the reduction of chronic disease risk in humans, including cardiovascular disease. In the current experiment, the potential to enhance milk n-3 content in two breeds with inherent genetic differences in mammary lipogenesis and de novo fatty acid synthesis was examined using extruded linseeds. Six lactating cows (three Holstein and three Jersey) were used in a two-treatment switchback design with 3 × 21-day experimental periods to evaluate the effect of iso-energetic replacement of calcium salts of palm oil distillate (CPO) in the diet (34 g/kg dry matter (DM)) with 100 g/kg DM extruded linseeds (LIN). For both breeds, replacing CPO with LIN had no effect (P > 0.05) on DM intake or milk yield, but reduced (P < 0.05) milk fat and protein yield (on average, from 760 to 706 and 573 to 552 g/day, respectively). Relative to CPO, the LIN treatment reduced (P < 0.01) total saturated fatty acid content and enhanced (P < 0.001) 18:3n-3 in milk, whereas breed by diet interactions were significant for milk fat 16:0, total trans fatty acid and conjugated linoleic acid concentrations. Increases in 18:3n-3 intake derived from LIN in the diet were transferred into milk with a mean marginal transfer efficiency of 1.8%. Proportionate changes in milk fatty acid composition were greater in the Jersey, highlighting the importance of diet-genotype interactions on mammary lipogenesis. More extensive studies are required to determine the role of genotype on milk fat composition responses to oilseeds in the diet. PMID:22443561

Kliem, K E; Aikman, P C; Humphries, D J; Morgan, R; Shingfield, K J; Givens, D I

2009-12-01

293

Periparturient effects of feeding a low dietary cation-anion difference diet on acid-base, calcium, and phosphorus homeostasis and on intravenous glucose tolerance test in high-producing dairy cows.  

PubMed

Feeding rations with low dietary cation-anion difference (DCAD) to dairy cows during late gestation is a common strategy to prevent periparturient hypocalcemia. Although the efficacy of low-DCAD rations in reducing the incidence of clinical hypocalcemia is well documented, potentially deleterious effects have not been explored in detail. The objective of the study presented here was to determine the effect of fully compensated metabolic acidosis on calcium and phosphorus homeostasis, insulin responsiveness, and insulin sensitivity as well as on protein metabolism. Twenty multiparous Holstein-Friesian dairy cows were assigned to 1 of 2 treatment groups and fed a low-DCAD ration (DCAD = -9 mEq/100g, group L) or a control ration (DCAD = +11 mEq/100g, group C) for the last 3 wk before the expected calving date. Blood and urine samples were obtained periodically between 14 d before to 14 d after calving. Intravenous glucose tolerance tests and 24-h volumetric urine collection were conducted before calving as well as 7 and 14 d postpartum. Cows fed the low-DCAD ration had lower urine pH and higher net acid excretion, but unchanged blood pH and bicarbonate concentration before calving. Protein-corrected plasma Ca concentration 1 d postpartum was higher in cows on the low-DCAD diet when compared with control animals. Urinary Ca and P excretion was positively associated with urine net acid excretion and negatively associated with urine pH. Whereas metabolic acidosis resulted in a 6-fold increase in urinary Ca excretion, the effect on renal P excretion was negligible. A more pronounced decline of plasma protein and globulin concentration in the periparturient period was observed in cows on the low-DCAD diets resulting in significantly lower total protein and globulin concentrations after calving in cows on low-DCAD diets. Intravenous glucose tolerance tests conducted before and after calving did not reveal group differences in insulin response or insulin sensitivity. Our results indicate that fully compensated metabolic acidosis increased the Ca flux resulting in increased urinary calcium excretion before calving and increased plasma Ca concentration on the day after calving, whereas the effect on P homeostasis was unlikely to be clinically relevant. The clinical relevance of the effect of metabolic acidosis on the plasma protein and globulin concentration is unclear but warrants further investigation. PMID:21257041

Grünberg, W; Donkin, S S; Constable, P D

2011-02-01

294

Final report of the safety assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate as used in cosmetics.  

PubMed

L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate function in cosmetic formulations primarily as antioxidants. Ascorbic Acid is commonly called Vitamin C. Ascorbic Acid is used as an antioxidant and pH adjuster in a large variety of cosmetic formulations, over 3/4 of which were hair dyes and colors at concentrations between 0.3% and 0.6%. For other uses, the reported concentrations were either very low (<0.01%) or in the 5% to 10% range. Calcium Ascorbate and Magnesium Ascorbate are described as antioxidants and skin conditioning agents--miscellaneous for use in cosmetics, but are not currently used. Sodium Ascorbyl Phosphate functions as an antioxidant in cosmetic products and is used at concentrations ranging from 0.01% to 3%. Magnesium Ascorbyl Phosphate functions as an antioxidant in cosmetics and was reported being used at concentrations from 0.001% to 3%. Sodium Ascorbate also functions as an antioxidant in cosmetics at concentrations from 0.0003% to 0.3%. Related ingredients (Ascorbyl Palmitate, Ascorbyl Dipalmitate, Ascorbyl Stearate, Erythorbic Acid, and Sodium Erythorbate) have been previously reviewed by the Cosmetic Ingredient Review (CIR) Expert Panel and found "to be safe for use as cosmetic ingredients in the present practices of good use." Ascorbic Acid is a generally recognized as safe (GRAS) substance for use as a chemical preservative in foods and as a nutrient and/or dietary supplement. Calcium Ascorbate and Sodium Ascorbate are listed as GRAS substances for use as chemical preservatives. L-Ascorbic Acid is readily and reversibly oxidized to L-dehydroascorbic acid and both forms exist in equilibrium in the body. Permeation rates of Ascorbic Acid through whole and stripped mouse skin were 3.43 +/- 0.74 microg/cm(2)/h and 33.2 +/- 5.2 microg/cm(2)/h. Acute oral and parenteral studies in mice, rats, rabbits, guinea pigs, dogs, and cats demonstrated little toxicity. Ascorbic Acid and Sodium Ascorbate acted as a nitrosation inhibitor in several food and cosmetic product studies. No compound-related clinical signs or gross or microscopic pathological effects were observed in either mice, rats, or guinea pigs in short-term studies. Male guinea pigs fed a control basal diet and given up to 250 mg Ascorbic Acid orally for 20 weeks had similar hemoglobin, blood glucose, serum iron, liver iron, and liver glycogen levels compared to control values. Male and female F344/N rats and B6C3F(1) mice were fed diets containing up to 100,000 ppm Ascorbic Acid for 13 weeks with little toxicity. Chronic Ascorbic Acid feeding studies showed toxic effects at dosages above 25 mg/kg body weight (bw) in rats and guinea pigs. Groups of male and female rats given daily doses up to 2000 mg/kg bw Ascorbic Acid for 2 years had no macro- or microscopically detectable toxic lesions. Mice given Ascorbic Acid subcutaneous and intravenous daily doses (500 to 1000 mg/kg bw) for 7 days had no changes in appetite, weight gain, and general behavior; and histological examination of various organs showed no changes. Ascorbic Acid was a photoprotectant when applied to mice and pig skin before exposure to ultraviolet (UV) radiation. The inhibition of UV-induced suppression of contact hypersensitivity was also noted. Magnesium Ascorbyl Phosphate administration immediately after exposure in hairless mice significantly delayed skin tumor formation and hyperplasia induced by chronic exposure to UV radiation. Pregnant mice and rats were given daily oral doses of Ascorbic Acid up to 1000 mg/kg bw with no indications of adult-toxic, teratogenic, or fetotoxic effects. Ascorbic Acid and Sodium Ascorbate were not genotoxic in several bacterial and mammalian test systems, consistent with the antioxidant properties of these chemicals. In the presence of certain enzyme systems or metal ions, evidence of genotoxicity was seen. The National Toxicology Program (NTP) conducted a 2-year oral carcinogenesis bioassay of Ascorbic Acid (25,000 and 50,000 ppm) in F344/N ra

Elmore, Amy R

2005-01-01

295

Acyl Coenzyme A Thioesterase 7 Regulates Neuronal Fatty Acid Metabolism To Prevent Neurotoxicity  

PubMed Central

Numerous neurological diseases are associated with dysregulated lipid metabolism; however, the basic metabolic control of fatty acid metabolism in neurons remains enigmatic. Here we have shown that neurons have abundant expression and activity of the long-chain cytoplasmic acyl coenzyme A (acyl-CoA) thioesterase 7 (ACOT7) to regulate lipid retention and metabolism. Unbiased and targeted metabolomic analysis of fasted mice with a conditional knockout of ACOT7 in the nervous system, Acot7N?/?, revealed increased fatty acid flux into multiple long-chain acyl-CoA-dependent pathways. The alterations in brain fatty acid metabolism were concomitant with a loss of lean mass, hypermetabolism, hepatic steatosis, dyslipidemia, and behavioral hyperexcitability in Acot7N?/? mice. These failures in adaptive energy metabolism are common in neurodegenerative diseases. In agreement, Acot7N?/? mice exhibit neurological dysfunction and neurodegeneration. These data show that ACOT7 counterregulates fatty acid metabolism in neurons and protects against neurotoxicity. PMID:23459938

Ellis, Jessica M.; Wong, G. William

2013-01-01

296

Alpha-lipoic acid prevents mitochondrial damage and neurotoxicity in experimental chemotherapy neuropathy  

Microsoft Academic Search

The study investigates if alpha-lipoic acid is neuroprotective against chemotherapy induced neurotoxicity, if mitochondrial damage plays a critical role in toxic neurodegenerative cascade, and if neuroprotective effects of alpha-lipoic acid depend on mitochondria protection.We used an in vitro model of chemotherapy induced peripheral neuropathy that closely mimic the in vivo condition by exposing primary cultures of dorsal root ganglion (DRG)

Giorgia Melli; Michela Taiana; Francesca Camozzi; Daniela Triolo; Paola Podini; Angelo Quattrini; Franco Taroni; Giuseppe Lauria

2008-01-01

297

Palatinose and oleic acid act together to prevent pancreatic islet disruption in nondiabetic obese Zucker rats.  

PubMed

We showed previously that 8-wk consumption of a diet containing palatinose (P, a slowly-absorbed sucrose analogue) and oleic acid (O) ameliorates but a diet containing sucrose (S) and linoleic acid (L) aggravates metabolic abnormalities in Zucker fatty (fa/fa) rats. In this study, we aimed to identify early changes in metabolism in rats induced by certain combinations of carbohydrates and fatty acids. Specifically, male Zucker fatty rats were fed an isocaloric diet containing various combinations of carbohydrates (P; S) and fatty acids (O; L). After 4 wk, no significant differences in body weight, visceral fat mass, plasma parameters (glucose, insulin, lipids, and adipokines), hepatic adiposity and gene expression, and adipose inflammation were observed between dietary groups. In contrast, pancreatic islets of palatinose-fed (PO and PL) rats were smaller and less fibrotic than sucrose-fed (SO and SL) rats. The abnormal alpha-cell distribution and sporadic staining of active caspase-3 common to islets of linoleic-acid-fed rats were not observed in oleic-acid-fed (PO and SO) rats. Accordingly, progressive beta-cell loss was seen in SL rats, but not in PO rats. These findings suggest that pancreatic islets may be initial sites that translate the effects of different combinations of dietary carbohydrates and fats into metabolic changes. PMID:18797130

Sato, Kazusa; Arai, Hidekazu; Miyazawa, Yui; Fukaya, Makiko; Uebanso, Takashi; Koganei, Megumi; Sasaki, Hajime; Sato, Tadatoshi; Yamamoto, Hironori; Taketani, Yutaka; Takeda, Eiji

2008-08-01

298

Calcium alginate bead immobilization of cells containing tyrosine ammonia lyase activity for use in the production of p-hydroxycinnamic acid.  

PubMed

An Escherichia coli catalyst with tyrosine ammonia lyase activity (TAL) has been stabilized for repeated use in batch conversions of high tyrosine solids to p-hydroxycinnamic acid (pHCA). The TAL biocatalyst was stabilized by controlling the reaction pH to 9.8 +/- 0.1 and immobilizing the cells within a calcium alginate matrix that was cross-linked with glutaraldehyde and polyethyleneimine (GA/PEI). We found a GA range where the bead-encapsulated TAL was not inactivated, and the resulting cross-linking provided the beads with the mechanical stability necessary for repeated use in consecutive batch reactions with catalyst recycle. The GA/PEI calcium alginate TAL catalyst was used in 41 1-L batch reactions where 50 g L(-1) tyrosine was converted to 39 +/- 4 g L(-1) pHCA in each batch. The practical usefulness and ease of this process was demonstrated by scaling up the TAL bead immobilization and using the immobilized TAL catalyst in four 125-L bioconversion reactions to produce over 12 kg of purified pHCA. PMID:17461550

Trotman, Robert J; Camp, Carl E; Ben-Bassat, Arie; DiCosimo, Robert; Huang, Lixuan; Crum, Grace A; Sariaslani, F Sima; Haynie, Sharon L

2007-01-01

299

Oleanolic acid, a pentacyclic triterpenoid, induces rabbit platelet aggregation through a phospholipase C-calcium dependent signaling pathway  

Microsoft Academic Search

Oleanolic acid (3?-hydroxy-olea-12-en-28-oic), a pentacyclic triterpenoid, exists widely in the plant kingdom and has a wide\\u000a variety of pharmacological effects such as antitumor, antifungal, insecticidal, hepatoprotective and anti-HIV activities.\\u000a This paper reports that oleanolic acid induces the aggregation of rabbit platelets, a mechanism was also investigated. Oleanolic\\u000a acid at concentrations of 25, 50, 100 and 200 ?M induced the aggregation

Jung-Jin Lee; Yong-Ri Jin; Yong Lim; Ji-Yeon Yu; Tack-Joong Kim; Hwan-Soo Yoo; Hwa-Sup Shin; Yeo-Pyo Yun

2007-01-01

300

Fluorescence and FT-IR spectroscopic studies of Suwannee river fulvic acid complexation with aluminum, terbium and calcium  

Microsoft Academic Search

In this study fluorescence emission and IR spectroscopy have been used to investigate the interaction of the class A (oxygen seeking ‘hard acid’) metal Al3+, with Suwannee River fulvic acid. Addition of Al3+ ion results in a significant enhancement in fulvic acid fluorescence emission (at ?em=424 nm) and significant red shift of the excitation wavelength (from ?ex=324 nm to ?ex=344

Kelly M. Elkins; Donald J. Nelson

2001-01-01

301

Transgenic 6F tomatoes act on the small intestine to prevent systemic inflammation and dyslipidemia caused by Western diet and intestinally derived lysophosphatidic acid[S  

PubMed Central

We recently reported that levels of unsaturated lysophosphatidic acid (LPA) in the small intestine significantly correlated with the extent of aortic atherosclerosis in LDL receptor-null (LDLR?/?) mice fed a Western diet (WD). Here we demonstrate that WD increases unsaturated (but not saturated) LPA levels in the small intestine of LDLR?/? mice and causes changes in small intestine gene expression. Confirmation of microarray analysis by quantitative RT-PCR showed that adding transgenic tomatoes expressing the apoA-I mimetic peptide 6F (Tg6F) to WD prevented many WD-mediated small intestine changes in gene expression. If instead of feeding WD, unsaturated LPA was added to chow and fed to the mice: i) levels of LPA in the small intestine were similar to those induced by feeding WD; ii) gene expression changes in the small intestine mimicked WD-mediated changes; and iii) changes in plasma serum amyloid A, total cholesterol, triglycerides, HDL-cholesterol levels, and the fast-performance liquid chromatography lipoprotein profile mimicked WD-mediated changes. Adding Tg6F (but not control tomatoes) to LPA-supplemented chow prevented the LPA-induced changes. We conclude that: i) WD-mediated systemic inflammation and dyslipidemia may be in part due to WD-induced increases in small intestine LPA levels; and ii) Tg6F reduces WD-mediated systemic inflammation and dyslipidemia by preventing WD-induced increases in LPA levels in the small intestine. PMID:24085744

Navab, Mohamad; Hough, Greg; Buga, Georgette M.; Su, Feng; Wagner, Alan C.; Meriwether, David; Chattopadhyay, Arnab; Gao, Feng; Grijalva, Victor; Danciger, Janet S.; Van Lenten, Brian J.; Org, Elin; Lusis, Aldons J.; Pan, Calvin; Anantharamaiah, G. M.; Farias-Eisner, Robin; Smyth, Susan S.; Reddy, Srinivasa T.; Fogelman, Alan M.

2013-01-01

302

The Effect of Preincubation of Seed Crystals of Uric Acid and Monosodium Urate with Undiluted Human Urine to Induce Precipitation of Calcium Oxalate in Vitro: Implications for Urinary  

E-print Network

Background: Previous studies demonstrated that crystals of uric acid (UA) and sodium urate (NaU) can induce the precipitation of calcium oxalate (CaOx) from its inorganic metastable solutions, but similar effects have not been unequivocally shown to occur in urine. The aim of this investigation was to determine whether preincubation of these seeds with urine alter their ability to induce deposition of CaOx from solution and thus provide a possible explanation for discrepancy of results obtained from aqueous inorganic solutions and undiluted urine. Materials and Methods: The effects of commercial seed crystals of UA, NaU and CaOx (6 mg/100 ml) on CaOx crystallization were compared in a solution with the same crystals that had been preincubated for 3 hours with healthy

Stone Formation; Phulwinder K. Grover; Rosemary L. Ryall

2002-01-01

303

Acid precipitation and food quality: Inhibition of growth and survival in black ducks and mallards by dietary aluminum, calcium and phosphorus  

USGS Publications Warehouse

In areas impacted by acid precipitation, water chemistry of acidic ponds and streams often changes, resulting in increased mobilization of aluminum and decreased concentration of calcium carbonate. Aluminum binds with phosphorus and inhibits its uptake by organisms. Thus, invertebrate food organisms used by waterfowl may have inadequate Ca and P or elevated Al for normal growth and development. Acid rain and its effects may be one of the factors negatively impacting American black ducks (Anas rubripes) in eastern North America. One-day old mallards (A. platyrhynchos) and black ducks were placed on one of three Ca:P regimens: low:low (LL), normal:normal (NN), and low:high (LH) with each regimen divided further into three or four Al levels for 10 weeks. Forty-five % of the black ducks died on nine different diets whereas only 28% of the mallards died on three different diets. Mortality was significantly related to diet in both species. Growth rates for body weight, culmens, wings, and tarsi of both species on control diets exceeded those on many treatment diets but the differences were less apparent for mallards than for black ducks. Differences among treatments were due to both Ca:P and Al levels.

Sparling, D.W.

1990-01-01

304

Prevention of N-nitrosodiethylamine-induced lung tumorigenesis by ellagic acid and quercetin in mice.  

PubMed

The polyphenolic antioxidants, consumed as an integral part of vegetables, fruits and beverages, are suggested as possessing anticarcinogenic properties. In the present study we have looked into the anticarcinogenic potential of plant polyphenols ellagic acid (EA) and quercetin against N-nitrosodiethylamine-induced lung tumorigenesis in mice. Ellagic acid was able to significantly reduce tumour incidence to 20% from the control value of 72.2%. Similarly, tumour burden was also decreased, although not significantly, from 3.15 to 2.5. Quercetin (QR) caused the tumour incidence to decrease from 76.4% to 44.4% when fed until the third dose of carcinogen. Both of the polyphenols suppressed the tumour incidence mainly by acting at the initiation phase of the carcinogenesis, since continuing the feeding of polyphenols until the termination of the experiment did not cause any apparent change in tumour incidence or tumour burden. Besides this, ellagic acid was found to be a better chemopreventor than quercetin. In order to search for their mechanism of action, the effect of feeding of these compounds on reduced glutathione (GSH), an important endogenous antioxidant, and on lipid peroxidation was investigated. Both ellagic acid and QR caused a significant increase in GSH and decrease in NADPH- and ascorbate-dependent lipid peroxidation. Ellagic acid was found to be more effective in decreasing the lipid peroxidation and increasing the GSH. This may be one of the reasons for its observed better anticarcinogenic property as compared to quercetin. PMID:10418948

Khanduja, K L; Gandhi, R K; Pathania, V; Syal, N

1999-04-01

305

?-Linolenic Acid-Enriched Diet Prevents Myocardial Damage and Expands Longevity in Cardiomyopathic Hamsters  

PubMed Central

Randomized clinical trials have demonstrated that the increased intake of ?-3 polyunsaturated fatty acids significantly reduces the risk of ischemic cardiovascular disease, but no investigations have been performed in hereditary cardiomyopathies with diffusely damaged myocardium. In the present study, ?-sarcoglycan-null cardiomyopathic hamsters were fed from weaning to death with an ?-linolenic acid (ALA)-enriched versus standard diet. Results demonstrated a great accumulation of ALA and eicosapentaenoic acid and an increased eicosapentaenoic/arachidonic acid ratio in cardiomyopathic hamster hearts, correlating with the preservation of myocardial structure and function. In fact, ALA administration preserved plasmalemma and mitochondrial membrane integrity, thus maintaining proper cell/extracellular matrix contacts and signaling, as well as a normal gene expression profile (myosin heavy chain isoforms, atrial natriuretic peptide, transforming growth factor-?1) and a limited extension of fibrotic areas within ALA-fed cardiomyopathic hearts. Consequently, hemodynamic indexes were safeguarded, and more than 60% of ALA-fed animals were still alive (mean survival time, 293 ± 141.8 days) when all those fed with standard diet were deceased (mean survival time, 175.9 ± 56 days). Therefore, the clinically evident beneficial effects of ?-3 polyunsaturated fatty acids are mainly related to preservation of myocardium structure and function and the attenuation of myocardial fibrosis. PMID:17148657

Fiaccavento, Roberta; Carotenuto, Felicia; Minieri, Marilena; Masuelli, Laura; Vecchini, Alba; Bei, Roberto; Modesti, Andrea; Binaglia, Luciano; Fusco, Angelo; Bertoli, Aldo; Forte, Giancarlo; Carosella, Luciana; Di Nardo, Paolo

2006-01-01

306

Docosahexaenoic acid prevents paraquat-induced reactive oxygen species production in dopaminergic neurons via enhancement of glutathione homeostasis.  

PubMed

Omega-3 polyunsaturated fatty acid levels are reduced in the substantia nigra area in Parkinson's disease patients and animal models, implicating docosahexaenoic acid (DHA) as a potential treatment for preventing Parkinson's disease and suggesting the need for investigations into how DHA might protect against neurotoxin-induced dopaminergic neuron loss. The herbicide paraquat (PQ) induces dopaminergic neuron loss through the excessive production of reactive oxygen species (ROS). We found that treatment of dopaminergic SN4741 cells with PQ reduced cell viability in a dose-dependent manner, but pretreatment with DHA ameliorated the toxic effect of PQ. To determine the toxic mechanism of PQ, we measured intracellular ROS content in different organelles with specific dyes. As expected, all types of ROS were increased by PQ treatment, but DHA pretreatment selectively decreased cytosolic hydrogen peroxide content. Furthermore, DHA treatment-induced increases in glutathione reductase and glutamate cysteine ligase modifier subunit (GCLm) mRNA expression were positively correlated with glutathione (GSH) content. Consistent with this increase in GCLm mRNA levels, Western blot analysis revealed that DHA pretreatment increased nuclear factor-erythroid 2 related factor 2 (Nrf2) protein levels. These findings indicate that DHA prevents PQ-induced neuronal cell loss by enhancing Nrf2-regulated GSH homeostasis. PMID:25545062

Lee, Hyoung Jun; Han, Jeongsu; Jang, Yunseon; Kim, Soo Jeong; Park, Ji Hoon; Seo, Kang Sik; Jeong, Soyeon; Shin, Soyeon; Lim, Kyu; Heo, Jun Young; Kweon, Gi Ryang

2015-01-30

307

Dietary glutamine supplementation prevents mucosal injury and modulates intestinal epithelial restitution following acetic acid induced intestinal injury in rats  

PubMed Central

Beneficial effects of glutamine (GLN) have been described in many gastrointestinal disorders. The aim of the present study was to evaluate the preventative effect of oral GLN supplementation against acetic acid (AA) induced intestinal injury in a rat. Male Sprague–Dawley rats were divided into four experimental groups: control (CONTR) rats underwent laparotomy, control-glutamine (CONTR-GLN) rats were treated with enteral glutamine given in drinking water (2%) 48 hours before and five days following laparotomy, AA rats underwent laparotomy and injection of AA into an isolated jejunal loop, and acetic acid-glutamine (AA-GLN) rats underwent AA-induced injury and were treated with enteral GLN 48 hours before and 5 days following laparotomy. Intestinal mucosal damage (Park’s injury score), mucosal structural changes, enterocyte proliferation and enterocyte apoptosis were determined five days following intestinal injury. Western blotting was used to determine p-ERK and bax protein levels. AA-induced intestinal injury resulted in a significantly increased intestinal injury score with concomitant inhibition of cell turnover (reduced proliferation and enhanced apoptosis). Treatment with dietary GLN supplementation resulted in a decreased intestinal injury score with concomitant stimulation of cell turnover (enhanced proliferation and reduced apoptosis). In conclusion, pre-treatment with oral GLN prevents mucosal injury and improves intestinal recovery following AA-induced intestinal injury in rats. PMID:23919638

2013-01-01

308

Ferulic acid prevents pathological and functional abnormalities of the kidney in Otsuka Long-Evans Tokushima Fatty diabetic rats.  

PubMed

We investigated the preventive effects of ferulic acid (FA) and alpha-tocopherol (AT) on the progression of diabetic nephropathy. Otsuka Long-Evans Tokushima Fatty (OLETF) and Long-Evans Tokushima Otsuka (LETO) rats were used as type 2 diabetes and non-diabetes models, respectively. Two-thirds of the OLETF rats were fed 0.2% FA-containing or 0.5% AT-containing chow. Diabetic nephropathy was assessed based on urinary protein excretion and pathological changes which were scored based on the percentages of extracellular matrix area in the glomerular area. Furthermore, renal messenger RNA (mRNA) expression of intercellular adhesion molecule-1 (ICAM-1), cyclooxygenase-2 (COX-2) and transforming growth factor-beta1 (TGF-beta1) was quantified by real-time polymerase chain reaction. After 12 weeks of FA- or AT-supplementation, urinary protein in untreated-OLETF group was significantly higher than that in LETO group, thus FA-supplementation significantly decreased urinary protein excretion. Pathological scores in FA-supplemented group were significantly lower than those in untreated OLETF group. Supplementation with either FA or AT significantly prevented the elevation of TGF-beta1 mRNA expression caused by diabetes. Treatment with neither FA nor AT had a significant effect on COX-2 or ICAM-1 mRNA expressions. We have demonstrated the preventative effects of FA on diabetic nephropathy via suppression of TGF-beta1 upregulation, furthermore FA may be more potent than AT. PMID:17897750

Fujita, Atsuyo; Sasaki, Hideyuki; Doi, Asako; Okamoto, Kunihisa; Matsuno, Shohei; Furuta, Hiroto; Nishi, Masahiro; Nakao, Taisei; Tsuno, Takuo; Taniguchi, Hisaji; Nanjo, Kishio

2008-01-01

309

Corrosion Prevention of Cold Rolled Steel Using Water Dispersible Lignosulfonic Acid Doped Polyaniline  

NASA Technical Reports Server (NTRS)

The invention provides coatings useful for preventing corrosion of metals. The coatings comprise a film-forming resin and conductive polymers comprising linearly conjugated x-systems and residues of sulfonated lignin or a sulfonated polyflavonoid or derivatives of solfonated lignin or a sulfonated polyflavonoid. The invention also provides a latex formulation of the coatings, and articles of manufacture comprising a metal substrate and a coating in contact with the metal substrate.

Viswanathan, Tito (Inventor)

2007-01-01

310

Corrosion prevention of cold rolled steel using water dispersible lignosulfonic acid doped polyaniline  

NASA Technical Reports Server (NTRS)

The invention provides coatings useful for preventing corrosion of metals. The coatings comprise a film-forming resin and conductive polymers comprising linearly conjugated .pi.-systems and residues of sulfonated lignin or a sulfonated polyflavonoid or derivatives of solfonated lignin or a sulfonated polyflavonoid. The invention also provides a latex formulation of the coatings, and articles of manufacture comprising a metal substrate and a coating in contact with the metal substrate.

Viswanathan, Tito (Inventor)

2007-01-01

311

CORROSION PREVENTION OF COLD ROLLED STEEL USING WATER DISPERSIBLE LIGNOSULFONIC ACID DOPED POLYANILINE  

NASA Technical Reports Server (NTRS)

The invention provides coatings useful for preventing corrosion of metals. The coatings comprise a film-forming resin and conductive polymers comprising linearly conjugated pi-systems and residues of sulfonated lignin or a sulfonated polyflavonoid or derivatives of sulfonated lignin or a sulfonated polyflavonoid. The invention also provides a latex formulation of the coatings, and articles of manufacture comprising a metal substrate and a coating in contact with the metal substrate.

Viswanathan, Tito (Inventor)

2005-01-01

312

Prevention of Alzheimer's disease: Omega3 fatty acid and phenolic anti-oxidant interventions  

Microsoft Academic Search

Alzheimer's disease (AD) and cardiovascular disease (CVD) are syndromes of aging that share analogous lesions and risk factors, involving lipoproteins, oxidative damage and inflammation. Unlike in CVD, in AD, sensitive biomarkers are unknown, and high-risk groups are understudied. To identify potential prevention strategies in AD, we have focused on pre-clinical models (transgenic and amyloid infusion models), testing dietary\\/lifestyle factors strongly

Greg M. Cole; Giselle P. Lim; Fusheng Yang; Bruce Teter; Aynun Begum; Qiulan Ma; Marni E. Harris-White; Sally A. Frautschy

2005-01-01

313

Natural xenobiotics to prevent cyanobacterial and algal growth in freshwater: contrasting efficacy of tannic acid, gallic acid, and gramine.  

PubMed

Allelochemical action against planktonic phototrophs is one central issue in freshwater ecology and quality management. To determine some basic mechanisms of this toxic action, we exposed the coccal green alga, Desmodesmus armatus, and the coccal cyanobacterium, Microcystis aeruginosa, in a batch culture well-supplied with carbon dioxide to increasing concentrations of the polyphenols tannic acid and gallic acid and the alkaloid gramine. The phototrophs were checked after 2d and at the end of the culture for biomass-based growth rates, cell volume, maximum quantum yield of photosystem II (?PSIImax), chlorophyll a content (chla) after 2d and at the end of the culture, and lipid peroxidation only at the end of the culture. During the culture, the pH rose from 7.64 to 10.95, a pH characteristic of eutrophic freshwater bodies during nuisance algal blooms. All xenobiotics reduced the growth rate, ?PSIImax, and chla during the first 2d with M. aeruginosa being more sensitive to the polyphenols than D. armatus. The efficacy of the polyphenols declined with increasing pH, indicating potential polymerization and corresponding reduced bioavailability of the polyphenols. In contrast to the polyphenols, gramine increased its toxic action over time, independent of the prevailing pH. All exposures caused slight to severe lipid peroxidation (LPO) in the phototrophs. Hence, one mechanism of growth inhibition may be oxidative stress-mediated reduction in photosynthesis. The presented results suggest that in successful field trials with leachate, the prevailing environmental conditions may inactivate polyphenols and xenobiotics other than polyphenols may be more effective. PMID:24332729

Laue, Pauline; Bährs, Hanno; Chakrabarti, Shumon; Steinberg, Christian E W

2014-06-01

314

Interleukin-1? Inhibits Insulin Signaling and Prevents Insulin-Stimulated System A Amino Acid Transport in Primary Human Trophoblasts  

PubMed Central

Interleukin-1? (IL-1?) promotes insulin resistance in tissues such as liver and skeletal muscle; however the influence of IL-1? on placental insulin signaling is unknown. We recently reported increased IL-1? protein expression in placentas of obese mothers, which could contribute to insulin resistance. In this study, we tested the hypothesis that IL-1? inhibits insulin signaling and prevents insulin-stimulated amino acid transport in cultured primary human trophoblast (PHT) cells. Cultured trophoblasts isolated from term placentas were treated with physiological concentrations of IL-1? (10 pg/ml) for 24 hours. IL-1? increased the phosphorylation of insulin receptor substrate-1 (IRS-1) at Ser307 (inhibitory) and decreased total IRS-1 protein abundance but did not affect insulin receptor ? expression. Furthermore, IL-1? inhibited insulin-stimulated phosphorylation of IRS-1 (Tyr612, activation site) and Akt (Thr308) and prevented insulin-stimulated increase in PI3K/p85 and Grb2 protein expression. IL-1? alone stimulated cRaf (Ser338), MEK (Ser221) and Erk1/2 (Thr202/Tyr204) phosphorylation. The inflammatory pathways nuclear factor kappa B and c-Jun N-terminal kinase, which are involved in insulin resistance, were also activated by IL-1? treatment. Moreover, IL-1? inhibited insulin-stimulated System A, but not System L amino acid uptake, indicating functional impairment of insulin signaling. In conclusion, IL-1? inhibited the insulin signaling pathway by inhibiting IRS-1 signaling and prevented insulin-stimulated System A transport, thereby promoting insulin resistance in cultured PHT cells. These findings indicate that conditions which lead to increased systemic maternal or placental IL-1? levels may attenuate the effects of maternal insulin on placental function and consequently fetal growth. PMID:23891856

Aye, Irving L. M. H.; Jansson, Thomas; Powell, Theresa L.

2013-01-01

315

The role of extracellular free-calcium gradients in gravitropic signalling in maize roots  

NASA Technical Reports Server (NTRS)

Gravitropism in roots has been proposed to depend on a downward redistribution of calcium across the root cap. However, because of the many calcium-binding sites in the apoplast, redistribution might not result in a physiologically effective change in the apoplasmic calcium activity. To test whether there is such a change, we measured the effect of gravistimulation on the calcium activity of statocyte cell walls with calcium-specific microelectrodes. Such a measurement must be made on a tissue with gravity sensing cells at the surface. To obtain such a tissue, decapped maize roots (Zea mays L. cv. Golden Cross Bantam) were grown for 31 h to regenerate gravitropic sensitivity, but not root caps. The calcium activity in the apoplasm surrounding the gravity-sensing cells could then be measured. The initial pCa was 2.60 +/- 0.28 (approx 2.5 mM). The calcium activity on the upper side of the root tip remained constant for 10 min after gravistimulation, then decreased 1.7-fold. On the lower side, after a similar lag the calcium activity increased 1.6-fold. Control roots, which were decapped but measured before recovering gravisensitivity (19 h), showed no change in calcium activity. To test whether this gradient is necessary for gravitropic curvature, we eliminated the calcium activity gradient during gravitropism by applying a mobile calcium-binding site (dinitro-BAPTA; 1,2-bis(2-amino-5-nitro-phenoxy)ethane-N,N,N',N'-tetraacetic acid) to the root cap; this treatment eliminated gravicurvature. A calcium gradient may be formed by proton-induced calcium desorption if there is a proton gradient. Preventing the formation of apoplastic pH gradients, using 10 and 50 mM 2-(N-morpholino)ethanesulfonic acid (Mes) buffer or 10 mM fusicoccin to stimulate proton excretion maximally, did not inhibit curvature; therefore the calcium gradient is not a secondary effect of a proton gradient. We have found a distinct and rapid differential in the apoplasmic calcium activity between the upper and lower sides of gravistimulated maize root tips which is necessary for gravitropism.

Bjorkman, T.; Cleland, R. E.

1991-01-01

316

Ascorbic acid prevents lipid peroxidation and oxidative damage of proteins in guinea pig extrahepatic tissue microsomes  

Microsoft Academic Search

It has recently been indicated that in the absence of free iron, NADPH initiates oxidative damage of proteins in guinea pig liver microsomes and also lipid peroxidation and protein damage in cardiac microsomes and that ascorbic acid specifically inhibits both the lipid peroxidation and protein damage [Mukhopadhyay CK, Chatterjee IB: J Biol Chem 269: 13390–13397, 1994; Mukhopadhyay Met al.: Mol

Chinmay K. Mukhopadhyay; Mrinal K. Ghosh; Indu B. Chatterjee

1995-01-01

317

A laboratory study of covers made of low-sulphide tailings to prevent acid mine drainage  

Microsoft Academic Search

Covers with capillary barrier effects (CCBE) are considered to be one of the most effective ways to control acid mine drainage (AMD) production from mine wastes. The use of low-sulphide tailings in CCBE has been proposed recently for cases where other types of material may be unavailable near the mining site. This paper presents leaching column test results showing that

B. Bussière; M. Benzaazoua; M. Aubertin; M. Mbonimpa

2004-01-01

318

The role of lactic acid bacteria in colon cancer prevention: mechanistic considerations  

Microsoft Academic Search

Colorectal cancer is one of the most important causes of cancer morbidity and mortality in Western countries. While a myriad of healthful effects have been attributed to the probiotic lactic acid bacteria, perhaps the most controversial remains that of anticancer activity. It should be pointed out already at this point that there is no direct experimental evidence for cancer suppression

Kazuhiro Hirayama; Joseph Rafter

1999-01-01

319

Lack of effect of eicosapentaenoic acid in preventing cancer cachexia and inhibiting tumor growth  

Microsoft Academic Search

It has been recently reported that a diet enriched in n-3 polyunsaturated fatty acids reduces the growth of different kinds of tumors as well as the host tissue hypercatabolic state frequently associated. The rat ascites hepatoma Yoshida AH-130 is a fast growing tumor that causes a rapid and progressive body weight loss in the host and tissue waste associated with

Paola Costelli; Marta Llovera; Joaquín López-Soriano; Neus Carbó; Luciana Tessitore; Francisco J. López-Soriano; Francesco M. Baccino; Josep M. Argilés

1995-01-01

320

Helicobacter pylori infection prevents erosive reflux oesophagitis by decreasing gastric acid secretion  

Microsoft Academic Search

BACKGROUNDHelicobacter pylori infection is less prevalent and atrophic gastritis is less extensive in patients with reflux oesophagitis than those without it, but few studies have examined this relationship directly.AIMSWe investigated the relationship between H pylori infection, acid secretion, and reflux oesophagitis in Japanese subjects.SUBJECTSA total of 105 patients with erosive reflux oesophagitis were compared with 105 sex and age matched

T Koike; S Ohara; H Sekine; K Iijima; Y Abe; K Kato; T Toyota; T Shimosegawa

2001-01-01

321

Cyclic GMP signaling in cardiomyocytes modulates fatty acid trafficking and prevents triglyceride accumulation  

Technology Transfer Automated Retrieval System (TEKTRAN)

While the balance between carbohydrates and fatty acids for energy production appears to be crucial for cardiac homeostasis, much remains to be learned about the molecular mechanisms underlying this relationship. Given the reported benefits of cGMP signaling on the myocardium, we investigated the im...

322

Feast or famine: role of TRPML in preventing cellular amino acid starvation.  

PubMed

Lysosomal storage diseases are metabolic disorders characterized by the accumulation of acidic vacuoles, and are usually the consequence of the deficiency of an enzyme responsible for the metabolism of vesicular lipids, proteins or carbohydrates. In contrast, mucolipidosis type IV (MLIV), results from the absence of a vesicular Ca ( 2+) release channel called mucolipin 1/transient receptor potential mucolipin 1 (MCOLN1/TRPML1) which is required for the fusion of amphisomes with lysosomes. In Drosophila, ablation of the MCOLN1 homolog (trpml) leads to diminished viability during pupation when the animals rely on autophagy for nutrients. This pupal lethality results from decreased target of rapamycin complex 1 (TORC1) signaling, and is reversed by reactivating TORC1. Our findings indicate that one of the primary causes of toxicity in the absence of TRPML is cellular amino acid starvation, and the resulting decrease in TORC1 activity. Furthermore, our findings raise the intriguing possibility that the neurological dysfunction in MLIV patients may arise from amino acid deprivation in neurons. Therefore, future studies evaluating the levels of amino acids and TORC1 activity in MLIV neurons may aid in the development of novel therapeutic strategies to combat the severe manifestations of MLIV. PMID:23047439

Venkatachalam, Kartik; Wong, Ching-On; Montell, Craig

2013-01-01

323

The role of omega-3 fatty acids in the secondary prevention of cardiovascular disease  

Microsoft Academic Search

Summary It has long been recognized from epidemiological studies that Greenland Eskimos have substantially reduced rates of acute myocardial infarction (MI) compared with Western controls. From these epidemiological observations, the benefits of fatty fish consumption have been explored in cell culture and animal studies, as well as randomized con- trolled trials investigating the cardioprotective effects of omega-3 fatty acids. Dietary

K. W. Lee; G. Y. H. LIP

2003-01-01

324

PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS  

EPA Science Inventory

Exposed, open pit mine highwalls contribute significantly to the production of acid mine drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

325

Beneficial Effect of Food Substitute Containing L-Arginine, ?-3 Poly Unsaturated Fatty Acid, and Ribonucleic Acid in Preventing or Improving Metabolic Syndrome: A Study in 15 Overweight Patients and a Study of Fatty Acid Metabolism in Animals  

PubMed Central

This study was conducted to investigate whether or not a food substitute (Dr. BAANs®) containing three bioactive components L-arginine, ?-3 polyunsaturated fatty acid, and ribonucleic acid, supplied orally to 15 overweight patients, may have efficacy to prevent or improve the metabolic syndrome of these patients. To provide supporting data for this clinical study, the in vivo fatty acid metabolism of obese mice was analyzed using 125I labeled 15-(p-iodophenyl)-9-methylpentadecanoic acid (9MPA) in the tissues’ lipid pool. After 3 months of intervention, the results showed that there were improvements observed in liver functions, lipid profiles and metabolic syndrome marker. Significant differences were also found in the values of blood pressure, body weight, percentage of body fat, and body mass index. In the animal study, the tissue uptake of 125I-9MPA at 10 min after injection was higher in obese mice than in the control mice and the treatment with Dr. BAANs® in obese mice decreased the uptake significantly. The final product metabolite of p-iodophenylacetic acid in obese mice was increased significantly by the treatment. In conclusion, this food substitute may have a beneficial effect for the prevention or improvement of metabolic syndrome. PMID:19430616

Watanabe, Kenichi; Arozal, Wawaimuli; Tanaka, Hiroko; Ma, Meilei; Satoh, Susumu; Veeraveedu, Punniyakoti T.; Kobayashi, Takashi; Oyama, Hiroshi; Sakaguchi, Yoshiko

2009-01-01

326

Ursolic acid protects monocytes against metabolic stress-induced priming and dysfunction by preventing the induction of Nox4?  

PubMed Central

Aims Dietary supplementation with ursolic acid (UA) prevents monocyte dysfunction in diabetic mice and protects mice against atherosclerosis and loss of renal function. The goal of this study was to determine the molecular mechanism by which UA prevents monocyte dysfunction induced by metabolic stress. Methods and results Metabolic stress sensitizes or “primes” human THP-1 monocytes and murine peritoneal macrophages to the chemoattractant MCP-1, converting these cells into a hyper-chemotactic phenotype. UA protected THP-1 monocytes and peritoneal macrophages against metabolic priming and prevented their hyper-reactivity to MCP-1. UA blocked the metabolic stress-induced increase in global protein-S-glutathionylation, a measure of cellular thiol oxidative stress, and normalized actin-S-glutathionylation. UA also restored MAPK phosphatase-1 (MKP1) protein expression and phosphatase activity, decreased by metabolic priming, and normalized p38 MAPK activation. Neither metabolic stress nor UA supplementation altered mRNA or protein levels of glutaredoxin-1, the principal enzyme responsible for the reduction of mixed disulfides between glutathione and protein thiols in these cells. However, the induction of Nox4 by metabolic stress, required for metabolic priming, was inhibited by UA in both THP-1 monocytes and peritoneal macrophages. Conclusion UA protects THP-1 monocytes against dysfunction by suppressing metabolic stress-induced Nox4 expression, thereby preventing the Nox4-dependent dysregulation of redox-sensitive processes, including actin turnover and MAPK-signaling, two key processes that control monocyte migration and adhesion. This study provides a novel mechanism for the anti-inflammatory and athero- and renoprotective properties of UA and suggests that dysfunctional blood monocytes may be primary targets of UA and related compounds. PMID:24494201

Ullevig, Sarah L.; Kim, Hong Seok; Nguyen, Huynh Nga; Hambright, William S.; Robles, Andrew J.; Tavakoli, Sina; Asmis, Reto

2014-01-01

327

Fatty Acid Profile and Physical Properties of Milk Fat from Cows fed Calcium Salts of Fatty Acids with Varying Unsaturation1  

Microsoft Academic Search

Holstein cows (n = 24) averaging 42 d in milk were used in a randomized complete block design during a 4-wk trial. A control total mixed ration (TMR) was compared with TMR supplemented with Ca salts of fatty acids from canola oil, soybean oil, or linseed oil. The three vegetable oils were progressively more un- saturated; the dominant fatty acids

P. Y. Chouinard; V. Girard; G. J. Brisson

1998-01-01

328

Continuous Production of Lactic Acid from Whey Perméate by Free and Calcium Alginate Entrapped Lactobacillus helveticus1  

Microsoft Academic Search

Lactobacillus belveticus strain milano was used for the continuous fermentation of lactic acid in cheese whey-yeast extract permeate medium. The best productivity of lactic acid was with the free cell system, which was 9.7 g\\/L per h at a dilution rate of .352 h -1. Under such conditions, lactose conversion was 87.5%, based on the lactose concentration of 37.4 g\\/L

Denis Roy; Jacques Goulet; Anh Le Duy

1987-01-01

329

Innovative Approach to Prevent Acid Drainage from Uranium Mill Tailings Based on the Application of Na-Ferrate (VI)  

SciTech Connect

The operation of uranium mining and milling plants gives rise to huge amounts of wastes from both mining and milling operations. When pyrite is present in these materials, the generation of acid drainage can take place and result in the contamination of underground and surface waters through the leaching of heavy metals and radionuclides. To solve this problem, many studies have been conducted to find cost-effective solutions to manage acid mine drainage; however, no adequate strategy to deal with sulfide-ric h wastes is currently available. Ferrate (VI) is a powerful oxidizing agent in aqueous media. Under acidic conditions, the redox potential of the Ferrate (VI) ion is the highest of any other oxidant used in wastewater treatment processes. The standard half cell reduction potential of ferrate (VI) has been determined as +2.20 V to + 0.72 V in acidic and basic solutions, respectively. Ferrate (VI) exhibits a multitude of advantageous properties, including higher reactivity and selectivity than traditional oxidant alternatives, as well as disinfectant, flocculating, and coagulant properties. Despite numerous beneficial properties in environmental applications, ferrate (VI) has remained commercially unavailable. Starting in 1953, different methods for producing a high purity, powdered ferrate (VI) product were developed. However, producing this dry, stabilized ferrate (VI) product required numerous process steps which led to excessive synthesis costs (over $20/lb) thereby preventing bulk industrial use. Recently a novel synthesis method for the production of a liquid ferrate (VI) based on hypochlorite oxidation of ferric ion in strongly alkaline solutions has been discovered (USPTO 6,790,428; September 14, 2004). This on-site synthesis process dramatically reduces manufacturing cost for the production of ferrate (VI) by utilizing common commodity feedstocks. This breakthrough means that for the first time ferrate (VI) can be an economical alternative to treating acid mining drainage generating materials. The objective of the present study was to investigate a methodology of preventing the generation of acid drainage by applying ferrate (VI) to acid generating materials prior to the disposal in impoundments or piles. Oxidizing the pyritic material in mining waste could diminish the potential for acid generation and its related environmental risks and long-term costs at disposal sites. The effectiveness of toxic metals removal from acid mine drainage by applying ferrate (VI) is also examined. Preliminary results presented in this paper show that the oxidation of pyrite by ferrate is a first-order rate reaction in Fe(VI) with a half-life of about six hours. The stability of Fe(VI) in water solutions will not influence the reaction rate in a significant manner. New low-cost production methods for making liquid ferrate on-site makes this technology a very attractive option to mitigate one of the most pressing environmental problems in the mining industry. (authors)

Fernandes, H.M.; Reinhart, D.; Lettie, L.; Franklin, M.R. [University of Central Florida, P.O. Box. 162450, Orlando, FL, 32816-2450 (United States); Fernandes, H.M.; Franklin, M.R. [Institute of Radiation Protection and Dosimetry (IRD), Av. Salvador Allende s/n - Recreio - Rio de Janeiro - RJ - 22795-090 (Brazil); Sharma, V. [Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 (United States); Daly, L.J. [Ferrate Treatment Technologies, LLC, 6432 Pine Castle Blvd. Unit 2C, Orlando, FL, 32809 (United States)

2006-07-01

330

Conjugated linoleic acid (CLA) prevents age-associated skeletal muscle loss  

Microsoft Academic Search

In this study, we examined the effect of CLA isomers in preventing age-associated muscle loss and the mechanisms underlying this effect, using 12-months-old C57BL\\/6 mice fed 10% corn oil (CO) or a diet supplemented with 0.5% c9t11-CLA, t10c12-CLA, or c9t11-CLA+t10c12-CLA (CLA-mix) for 6months. Both t10c12-CLA and CLA-mix groups showed significantly higher muscle mass, as compared to CO and c9t11-CLA groups,

Ganesh V. Halade; Amina El Jamali; Gabriel Fernandes

2009-01-01

331

Inhibition of the HER2 pathway by n-3 polyunsaturated fatty acids prevents breast cancer in fat-1 transgenic mice  

PubMed Central

Overexpression of the tyrosine kinase receptor, ErbB2/HER2/Neu, occurs in 25–30% of invasive breast cancer (BC) with poor patient prognosis. Due to confounding factors, inconsistencies still remain regarding the protective effects of n-3 polyunsaturated fatty acids (PUFAs) on BC. We therefore evaluated whether fat-1 transgenic mice, endogenously synthesizing n-3 PUFAs from n-6 PUFAs, were protected against BC development, and we then aimed to study in vivo a mechanism potentially involved in such protection. E0771 BC cells were implanted into fat-1 and wild-type (WT) mice. After tumorigenesis examination, we analyzed the expression of proteins involved in the HER2 signaling pathway and lipidomic analyses were performed in tumor tissues and plasma. Our results showed that tumors totally disappeared by day 15 in fat-1 mice but continued to grow in WT mice. This prevention can be related in part to significant repression of the HER2/?-catenin signaling pathway and formation of significant levels of n-3 PUFA-derived bioactive mediators (particularly 15-hydroxyeicosapentaenoic acid, 17-hydroxydocosahexaenoic acid, and prostaglandin E3) in the tumors of fat-1 mice compared with WT mice. All together these data demonstrate an anti-BC effect of n-3 PUFAs through, at least in part, HER2 signaling pathway downregulation, and highlight the importance of gene-diet interactions in BC. PMID:24052576

Zou, Zuquan; Bellenger, Sandrine; Massey, Karen A.; Nicolaou, Anna; Geissler, Audrey; Bidu, Célia; Bonnotte, Bernard; Pierre, Anne-Sophie; Minville-Walz, Mélaine; Rialland, Michaël; Seubert, John; Kang, Jing X.; Lagrost, Laurent; Narce, Michel; Bellenger, Jérôme

2013-01-01

332

Tuning the Degradation Rate of Calcium Phosphate Cements by Incorporating Mixtures of Polylactic-co-Glycolic Acid Microspheres and Glucono-Delta-Lactone Microparticles.  

PubMed

Calcium phosphate cements (CPCs) are frequently used as synthetic bone graft materials in view of their excellent osteocompatibility and clinical handling behavior. Hydroxyapatite-forming CPCs, however, degrade at very low rates, thereby limiting complete bone regeneration. The current study has investigated whether degradation of apatite-forming cements can be tuned by incorporating acid-producing slow-resorbing poly(D,L-lactic-co-glycolic) acid (PLGA) porogens, fast-resorbing glucono-delta-lactone (GDL) porogens, or mixtures thereof. The physicochemical, mechanical, and degradation characteristics of these CPC formulations were systematically analyzed upon soaking in phosphate-buffered saline (PBS). In parallel, various CPC formulations were implanted intramuscularly and orthotopically on top of the transverse process of goats followed by analysis of the soft tissue response and bone ingrowth after 12 weeks. In vitro degradation of GDL was almost completed after 2 weeks, as evidenced by characterization of the release of gluconic acid, while PLGA-containing CPCs released glycolic acid throughout the entire study (12 weeks), resulting in a decrease in compression strength of CPC. Extensive in vitro degradation of the CPC matrix was observed upon simultaneous incorporation of 30% PLGA-10% GDL. Histomorphometrical evaluation of the intramuscularly implanted samples revealed that all CPCs exhibited degradation, accompanied by an increase in capsule thickness. In the in vivo goat transverse process model, incorporation of 43% PLGA, 30% PLGA-5% GDL, and 30% PLGA-10% GDL in CPC significantly increased bone formation and resulted in higher bone height compared with both 10% GDL and 20% GDL-containing CPC samples. PMID:24819744

Sariibrahimoglu, Kemal; An, Jie; van Oirschot, Bart A J A; Nijhuis, Arnold W G; Eman, Rhandy M; Alblas, Jacqueline; Wolke, Joop G C; van den Beucken, Jeroen J J P; Leeuwenburgh, Sander C G; Jansen, John A

2014-11-01

333

Topical trans-4-aminomethylcyclohexanecarboxylic acid prevents ultraviolet radiation-induced pigmentation  

Microsoft Academic Search

We have studied the effect of a plasmin inhibitor, trans-4-aminomethylcyclohexanecarboxylic acid (trans-AMCHA), on skin pigmentation induced by ultraviolet (UV) exposure in Weiser—Maples guinea pigs. When guinea pigs are exposed to UV radiation (840 mJ cm?2), skin pigmentation is clearly observed from seven days after exposure and continued to increase to 29 days. Post-exposure applications of 2 and 3% solutions of

Kazuhisa Maeda; Masako Naganuma

1998-01-01

334

Prevention of Ornithine Cytotoxicity by Nonpolar Side Chain Amino Acids in Retinal Pigment Epithelial Cells  

Microsoft Academic Search

PURPOSE. To investigate the effect of amino acids on ornithine cytotoxicity in ornithine--aminotransferase (OAT)- deficient human retinal pigment epithelial (RPE) cells as an in vitro model of gyrate atrophy (GA) of the choroid and retina. METHODS. RPE cells were treated with 0.5 mM 5-fluoromethyl- ornithine (5-FMOrn), a specific and irreversible OAT inhibitor. OAT-deficient RPE cells were incubated with 10 mM

Tadashi Nakauchi; Akira Ando; Mami Ueda-Yamada; Yukari Yamazaki; Masanobu Uyama; Miyo Matsumura; Seiji Ito

2003-01-01

335

A full-scale porous reactive wall for prevention of acid mine drainage  

SciTech Connect

The generation and release of acidic drainage containing high concentrations of dissolved metals from decommissioned mine wastes is an environmental problem of international scale. A potential solution to many acid drainage problems is the installation of permeable reactive walls into aquifers affected by drainage water derived from mine waste materials. A permeable reactive wall installed into an aquifer impacted by low-quality mine drainage waters was installed in August 1995 at the Nickel Rim mine site near Sudbury, Ontario. The reactive mixture, containing organic matter, was designed to promote bacterially mediated sulfate reduction and subsequent metal sulfide precipitation. The reactive wall is installed to an average depth of 12 feet (3.6 m) and is 49 feet (15 m) long perpendicular to ground water flow. The wall thickness (flow path length) is 13 feet (4 m). Initial results, collected nine months after installation, indicate that sulfate reduction and metal sulfide precipitation is occurring. The reactive wall has effectively removed the capacity of the ground water to generate acidity on discharge to the surface. Calculations based on comparison to previously run laboratory column experiments indicate that the reactive wall has potential to remain effective for at least 15 years.

Benner, S.G.; Blowes, D.W.; Ptacek, C.J.

1997-12-31

336

Preventing corona effects: multiphosphonic acid poly(ethylene glycol) copolymers for stable stealth iron oxide nanoparticles.  

PubMed

When dispersed in biological fluids, engineered nanoparticles are selectively coated with proteins, resulting in the formation of a protein corona. It is suggested that the protein corona is critical in regulating the conditions of entry into the cytoplasm of living cells. Recent reports describe this phenomenon as ubiquitous and independent of the nature of the particle. For nanomedicine applications, however, there is a need to design advanced and cost-effective coatings that are resistant to protein adsorption and that increase the biodistribution in vivo. In this study, phosphonic acid poly(ethylene glycol) copolymers were synthesized and used to coat iron oxide particles. The copolymer composition was optimized to provide simple and scalable protocols as well as long-term stability in culture media. It is shown that polymers with multiple phosphonic acid functionalities and PEG chains outperform other types of coating, including ligands, polyelectrolytes, and carboxylic acid functionalized PEG. PEGylated particles exhibit moreover exceptional low cellular uptake, of the order of 100 femtograms of iron per cell. The present approach demonstrates that the surface chemistry of engineered particles is a key parameter in the interactions with cells. It also opens up new avenues for the efficient functionalization of inorganic surfaces. PMID:25046557

Torrisi, V; Graillot, A; Vitorazi, L; Crouzet, Q; Marletta, G; Loubat, C; Berret, J-F

2014-08-11

337

Consequences of Calcium Deficiency on Embryogenesis in a Keystone Freshwater Crustacean: Daphnia magna .  

E-print Network

??Ambient calcium is declining in thousands of soft-water lake habitats as a consequence of unsustainable forestry practices, decreased atmospheric calcium deposition, and acidic deposition. The… (more)

Giardini, Jamie-Lee

2014-01-01

338

Effectiveness of acidic calcium sulfate with propionic and lactic acid and lactates as postprocessing dipping solutions to control Listeria monocytogenes on frankfurters with or without potassium lactate and stored vacuum packaged at 4.5 degrees C.  

PubMed

The safety of ready-to-eat meat products such as frankfurters can be enhanced by treating with approved antimicrobial substances to control the growth of Listeria monocytogenes. We evaluated the effectiveness of acidic calcium sulfate with propionic and lactic acid, potassium lactate, or lactic acid postprocessing dipping solutions to control L. monocytogenes inoculated (ca. 10(8) CFU/ml) onto the surface of frankfurters with or without potassium lactate and stored in vacuum packages at 4.5 degrees C for up to 12 weeks. Two frankfurter formulations were manufactured without (control) or with potassium lactate (KL, 3.3% of a 60% [wt/wt] commercially available syrup). After cooking, chilling, and peeling, each batch was divided into inoculated (four strains of L. monocytogenes mixture) and noninoculated groups. Each group was treated with four different dips: (i) control (saline solution), (ii) acidic calcium sulfate with propionic and lactic acid (ACS, 1:2 water), (iii) KL, or (iv) lactic acid (LA, 3.4% of a 88% [wt/wt] commercially available syrup) for 30 s. Noninoculated frankfurters were periodically analyzed for pH, water activity, residual nitrite, and aerobic plate counts (APCs), and L. monocytogenes counts (modified Oxford medium) were determined on inoculated samples. Surface APC counts remained at or near the lower limit of detection (<2 log CFU per frank) on franks with or without KL and treated with ACS or LA throughout 12 weeks at 4.5 degrees C. L. monoctogenes counts remained at the minimum level of detection on all franks treated with the ACS dip, which indicated a residual bactericidal effect when L. monocytogenes populations were monitored over 12 weeks. L. monocytogenes numbers were also reduced, but not to the same degree in franks made without or with KL and treated with LA. These results revealed the effectiveness of ACS (bactericidal effect) or LA (bacteriostatic effect) as postprocessing dipping solutions to inhibit or control the growth of L. monocytogenes on vacuum-packaged frankfurters stored at 4.5 degrees C for up to 12 weeks. PMID:15151227

Nuñez de Gonzalez, Maryuri T; Keeton, Jimmy T; Acuff, Gary R; Ringer, Larry J; Lucia, Lisa M

2004-05-01

339

Impact of Estradiol on ?-Aminobutyric Acid- and Glutamate-Mediated Calcium Responses of Fetal Baboon (Papio anubis) Hippocampal and Cortical Neurons  

PubMed Central

High levels of maternal estrogens are likely to gain access to the fetal brain, yet little is known regarding the role of the steroid hormone 17?-estradiol in neuronal differentiation and maturation of primate neurons. Previous research documented the presence of estrogen receptors during development in the hippocampus and cortex of the primate brain, but the functional significance of steroid exposure has not been widely investigated. Using both an in vitro preparation of primary hippocampal and frontal cortex neurons and Western blot analysis of fetal hippocampal and frontal cortex tissue, we documented the effects of in utero and acute in vitro exposure to 17?-estradiol on the development of neuronal responsiveness to the amino acid transmitters ?-aminobutyric acid (GABA) and glutamate in fetal baboon, Papio anubis, hippocampal, and cortical neurons. We found that in utero 17?-estradiol exposure enhanced the excitatory action of the GABAergic system on immature cortical and hippocampal neurons, as manifest by increases in intracellular calcium after transient muscimol application and changes in the relevant ion cotransporters. Acute exposure to 17?-estradiol in vitro had limited effect on GABAergic responses in cultured hippocampal and frontal cortex neurons. Moreover, there was limited effect of both prolonged in utero and acute estradiol on the response to glutamatergic system activation, consistent with previous findings in the rat. Along with documenting a prominent role for 17?-estradiol in maturation of the GABAergic system, these findings increase our understanding of neuronal differentiation and maturation in the fetal primate brain. PMID:18703635

Nuñez, Joseph L.; Aberdeen, Graham W.; Albrecht, Eugene D.; McCarthy, Margaret M.

2008-01-01

340

Taurine regulates mitochondrial calcium homeostasis.  

PubMed

We have investigated the protective role of taurine in glutamate-mediated cell death and the involvement of mitochondria in this process. In cultured cerebellar granule cells, glutamate induces a rapid and sustained elevation in cytoplasmic free calcium ([Ca2+]i), causing the collapse of the mitochondrial electrochemical gradient (MtECG) and subsequent cell death. We found that pre-treatment with taurine, did not affect the level of calcium uptake with glutamate but rather reduced its duration; the calcium increase was transient and returned to basal levels about 10 min after adding glutamate. Furthermore, taurine reduced mitochondrial calcium concentration under non-depolarizing conditions. Treatment of cerebellar granule cells with taurine enhanced mitochondrial activity as measured by rhodamine uptake, both in the presence or absence of glutamate. We conclude that taurine prevents or reduces glutamate excitotoxicity through both the enhancement of mitochondrial function and the regulation of intracellular (cytoplasmic and mitochondrial) calcium homeostasis. PMID:12908639

El Idrissi, Abdeslem; Trenkner, Ekkhart

2003-01-01

341

Calcium phosphate deposition rate, structure and osteoconductivity on electrospun poly(l-lactic acid) matrix using electrodeposition or simulated body fluid incubation  

PubMed Central

Mineralized nanofibrous scaffolds have been proposed as promising scaffolds for bone regeneration due to their ability to mimic both nanoscale architecture and chemical composition of natural bone extracellular matrix (ECM). In this study, a novel electrodeposition method was compared with an extensively explored simulated body fluid (SBF) incubation method in terms of the deposition rate, chemical composition, and morphology of calcium phosphate formed on electrospun fibrous thin matrices with a fiber diameter in the range from about 200 nm to about 1400 nm prepared using 6, 8, 10 and 12 wt% poly(l-lactic acid) (PLLA) solutions in a mixture of dichloromethane and acetone (2:1 in volume). The effects of the surface modification using the two mineralization techniques on osteoblastic cell (MC3T3-E1) proliferation and differentiation were also examined. It was found that electrodeposition was two to three orders of magnitude faster than the SBF method in mineralizing the fibrous matrices, reducing the mineralization time from about two weeks to an hour to achieve the same amounts of mineralization. The mineralization rate also varied with the fiber diameter but in opposite directions between the two mineralization methods. As a general trend, the increase of fiber diameter resulted in a faster mineralization rate for the electrodeposition method but a slower mineralization rate for the SBF incubation method. Using the electrodeposition method, one can control the chemical composition and morphology of the calcium phosphate by varying the electric deposition potential and electrolyte temperature to tune the mixture of dicalcium phosphate dihydrate (DCPD) and hydroxy apatite (HAp). Using the SBF method, one can only obtain a low crystallinity HAp. The mineralized electrospun PLLA fibrous matrices from either method similarly facilitate the proliferation and osteogenic differentiation of preosteoblastic MC3T3-E1 cells as compared to neat PLLA matrices. Therefore, the electrodeposition method can be utilized as a fast and versatile technique to fabricate mineralized nanofibrous scaffolds for bone tissue engineering. PMID:24012605

He, Chuanglong; Jin, Xiaobing; Ma, Peter X.

2013-01-01

342

Calcium phosphate deposition rate, structure and osteoconductivity on electrospun poly(l-lactic acid) matrix using electrodeposition or simulated body fluid incubation.  

PubMed

Mineralized nanofibrous scaffolds have been proposed as promising scaffolds for bone regeneration due to their ability to mimic both nanoscale architecture and chemical composition of natural bone extracellular matrix. In this study, a novel electrodeposition method was compared with an extensively explored simulated body fluid (SBF) incubation method in terms of the deposition rate, chemical composition and morphology of calcium phosphate formed on electrospun fibrous thin matrices with a fiber diameter in the range ~200-1400 nm prepared using 6, 8, 10 and 12 wt.% poly(l-lactic acid) (PLLA) solutions in a mixture of dichloromethane and acetone (2:1 in volume). The effects of the surface modification using the two mineralization techniques on osteoblastic cell (MC3T3-E1) proliferation and differentiation were also examined. It was found that electrodeposition was two to three orders of magnitude faster than the SBF method in mineralizing the fibrous matrices, reducing the mineralization time from ~2 weeks to 1h to achieve the same amounts of mineralization. The mineralization rate also varied with the fiber diameter but in opposite directions between the two mineralization methods. As a general trend, the increase of fiber diameter resulted in a faster mineralization rate for the electrodeposition method but a slower mineralization rate for the SBF incubation method. Using the electrodeposition method, one can control the chemical composition and morphology of the calcium phosphate by varying the electric deposition potential and electrolyte temperature to tune the mixture of dicalcium phosphate dihydrate and hydroxyapatite (HAp). Using the SBF method, one can only obtain a low crystallinity HAp. The mineralized electrospun PLLA fibrous matrices from either method similarly facilitate the proliferation and osteogenic differentiation of preosteoblastic MC3T3-E1 cells as compared to neat PLLA matrices. Therefore, the electrodeposition method can be utilized as a fast and versatile technique to fabricate mineralized nanofibrous scaffolds for bone tissue engineering. PMID:24012605

He, Chuanglong; Jin, Xiaobing; Ma, Peter X

2014-01-01

343

Abscisic Acid-Induced Actin Reorganization in Guard Cells of Dayflower Is Mediated by Cytosolic Calcium Levels and by Protein Kinase and Protein Phosphatase Activities1  

PubMed Central

In guard cells of open stomata under daylight, long actin filaments are arranged at the cortex, radiating out from the stomatal pore. Abscisic acid (ABA), a signal for stomatal closure, induces rapid depolymerization of cortical actin filaments and the slower formation of a new type of actin that is randomly oriented throughout the cell. This change in actin organization has been suggested to be important in signaling pathways involved in stomatal closing movement, since actin antagonists interfere with normal stomatal closing responses to ABA. Here we present evidence that the actin changes induced by ABA in guard cells of dayflower (Commelina communis) are mediated by cytosolic calcium levels and by protein phosphatase and protein kinase activities. Treatment of guard cells with CaCl2 induced changes in actin organization similar to those induced by ABA. Removal of extracellular calcium with EGTA inhibited ABA-induced actin changes. These results suggest that Ca2+ acts as a signal mediator in actin reorganization during guard cell response to ABA. A protein kinase inhibitor, staurosporine, inhibited actin reorganization in guard cells treated with ABA or CaCl2, and also increased the population of cells with long radial cortical actin filaments in untreated control cells. A protein phosphatase inhibitor, calyculin A, induced fragmentation of actin filaments in ABA- or CaCl2-treated cells and in control cells, and inhibited the formation of randomly oriented long actin filaments induced by ABA or CaCl2. These results suggest that protein kinase(s) and phosphatase(s) participate in actin remodeling in guard cells during ABA-induced stomatal closure. PMID:11299391

Hwang, Jae-Ung; Lee, Youngsook

2001-01-01

344

Cost analysis of use of tranexamic Acid to prevent major bleeding complications in hip and knee arthroplasty surgery.  

PubMed

We used decision analysis to assess the cost profile associated with preoperative use of tranexamic acid (TXA) to prevent major bleeding complications associated with hip and knee arthroplasty surgery. We defined major bleeding complications as blood loss sufficient to require transfusion or surgical evacuation of a postoperative hematoma. In the absence of a reduction in revision rates, using current cost data, TXA use is not cost-saving for institutions with baseline blood transfusion rates under 25%. For centers with baseline transfusion rates above 25%, however, TXA becomes increasingly cost-saving as the reduction in transfusion rates seen with use of the drug increases, but a minimum 12% reduction in transfusion rates is needed, even if the expected baseline transfusion rate is 100%. Nevertheless, TXA use is much more likely to be cost-saving, regardless of transfusion rates, if it leads to a reduction in need for revision surgery. PMID:25303447

Slover, James; Bosco, Joseph

2014-10-01

345

21 CFR 184.1187 - Calcium alginate.  

...alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Calcium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents, or...

2014-04-01

346

21 CFR 184.1187 - Calcium alginate.  

Code of Federal Regulations, 2011 CFR

...alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Calcium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents, or...

2011-04-01

347

21 CFR 184.1187 - Calcium alginate.  

Code of Federal Regulations, 2012 CFR

...alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Calcium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents, or...

2012-04-01

348

21 CFR 184.1187 - Calcium alginate.  

Code of Federal Regulations, 2013 CFR

...alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Calcium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents, or...

2013-04-01

349

21 CFR 184.1187 - Calcium alginate.  

Code of Federal Regulations, 2010 CFR

...alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Calcium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents, or...

2010-04-01

350

Prevention of alcoholic fatty liver and mitochondrial dysfunction in the rat by long-chain polyunsaturated fatty acids  

PubMed Central

Background/Aims We reported that reduced dietary intake of polyunsaturated fatty acids (PUFA) such as arachidonic (AA,20:4n6, omega-6) and docosahexaenoic (DHA,22:6n3, omega-3) acids led to alcohol-induced fatty liver and fibrosis. This study was aimed at studying the mechanisms by which a DHA/AA-supplemented diet prevents alcohol-induced fatty liver. Methods Male Long-Evans rats were fed an ethanol or control liquid-diet with or without DHA/AA for 9 weeks. Plasma transaminase levels, liver histology, oxidative/nitrosative stress markers, and activities of oxidatively-modified mitochondrial proteins were evaluated. Results Chronic alcohol administration increased the degree of fatty liver but fatty liver decreased significantly in rats fed the alcohol-DHA/AA-supplemented diet. Alcohol exposure increased oxidative/nitrosative stress with elevated levels of ethanol-inducible CYP2E1, nitric oxide synthase, nitrite and mitochondrial hydrogen peroxide. However, these increments were normalized in rats fed the alcohol-DHA/AA-supplemented diet. The number of oxidatively-modified mitochondrial proteins was markedly increased following alcohol exposure but significantly reduced in rats fed the alcohol-DHA/AA-supplemented diet. The suppressed activities of mitochondrial aldehyde dehydrogenase, ATP synthase, and 3-ketoacyl-CoA thiolase in ethanol-exposed rats were also recovered in animals fed the ethanol-DHA/AA-supplemented diet. Conclusions Addition of DHA/AA prevents alcohol-induced fatty liver and mitochondrial dysfunction in an animal model by protecting various mitochondrial enzymes most likely through reducing oxidative/nitrosative stress. PMID:18571270

Song, Byoung-Joon; Moon, Kwan-Hoon; Olsson, Nils U.; Salem, Norman

2008-01-01

351

The retinaldehyde reductase DHRS3 is essential for preventing the formation of excess retinoic acid during embryonic development  

PubMed Central

Oxidation of retinol via retinaldehyde results in the formation of the essential morphogen all-trans-retinoic acid (ATRA). Previous studies have identified critical roles in the regulation of embryonic ATRA levels for retinol, retinaldehyde, and ATRA-oxidizing enzymes; however, the contribution of retinaldehyde reductases to ATRA metabolism is not completely understood. Herein, we investigate the role of the retinaldehyde reductase Dhrs3 in embryonic retinoid metabolism using a Dhrs3-deficient mouse. Lack of DHRS3 leads to a 40% increase in the levels of ATRA and a 60% and 55% decrease in the levels of retinol and retinyl esters, respectively, in Dhrs3?/? embryos compared to wild-type littermates. Furthermore, accumulation of excess ATRA is accompanied by a compensatory 30–50% reduction in the expression of ATRA synthetic genes and a 120% increase in the expression of the ATRA catabolic enzyme Cyp26a1 in Dhrs3?/? embryos vs. controls. Excess ATRA also leads to alterations (40–80%) in the expression of several developmentally important ATRA target genes. Consequently, Dhrs3?/? embryos die late in gestation and display defects in cardiac outflow tract formation, atrial and ventricular septation, skeletal development, and palatogenesis. These data demonstrate that the reduction of retinaldehyde by DHRS3 is critical for preventing formation of excess ATRA during embryonic development.—Billings, S. E., Pierzchalski, K., Butler Tjaden, N. E., Pang, X.-Y., Trainor, P. A., Kane, M. A., Moise, A. R. The retinaldehyde reductase DHRS3 is essential for preventing the formation of excess retinoic acid during embryonic development. PMID:24005908

Billings, Sara E.; Pierzchalski, Keely; Butler Tjaden, Naomi E.; Pang, Xiao-Yan; Trainor, Paul A.; Kane, Maureen A.; Moise, Alexander R.

2013-01-01

352

Loblolly pine plant community structure and soil solution aluminum, organic acids, calcium, magnesium, and pH  

Microsoft Academic Search

Vegetative cover may influence soil chemical properties by producing organic acids that can modify the toxicity are responsible for high levels of nontoxic soil solution aluminum (Al). This study was conducted to determine the effect of loblolly pine (Pinus taeda L.) plant community structure, i.e., differing vegetative covers, on exchangeable cation distribution, and soil solution concentration of aluminum (Al) and

J. F. Adams; C. W. Wood; R. I. Mitchell

1999-01-01

353

Dietary Supplements of Two Doses of Calcium Salts of Conjugated Linoleic Acid During the Transition Period and Early Lactation  

Microsoft Academic Search

Reduction of milk fat secretion by the use of conju- gated linoleic acid (CLA) supplements may alleviate energy demands during early lactation. The objective of the present study was to evaluate lactational perfor- mance, net energy balance, and reproductive response of dairy cows supplemented with 2 doses of CLA from 2 wk before predicted calving until 9 wk postpartum. Holstein

E. Castañeda-Gutiérrez; T. R. Overton; W. R. Butler; D. E. Bauman

2005-01-01

354

Polyglycolic acid sheet application to prevent esophageal stricture after endoscopic submucosal dissection for esophageal squamous cell carcinoma.  

PubMed

Background and study aim: Esophageal stricture following endoscopic submucosal dissection (ESD) can be a serious complication in patients with large mucosal defects. This preliminary study examined the efficacy of using a polyglycolic acid (PGA) sheet with fibrin glue for the prevention of esophageal stricture after ESD. Patients and methods: A total of 15 patients were enrolled. After resection, PGA sheets were placed over the surgical wound. The size of the mucosal defect was estimated by dividing the circumference of the esophagus into 12 parts of equal size. The occurrence of esophageal stricture at 6 weeks, along with the proportion of patients who had PGA sheet remaining in place 1 week and 2 weeks after ESD, and the occurrence of adverse events were investigated. Results: The size of mucosal defects in the 15 patients were 7/12 (n?=?4), 8?/12 (n?=?5), 9/12 (n?=?4), 10/12 (n?=?1) and 11/12 (n?=?1). Esophageal stricture occurred in 1/13 patients (7.7?%; two patients were not included in the analysis because they had required surgical resection during the follow-up period). The PGA sheet remained at 1 week after ESD in 13/15 patients (86.7?%) and at 2 weeks after ESD in 6/15 patients (40?%). No adverse events were observed. Conclusion: PGA sheets may have the potential to prevent esophageal stricture. PMID:25412087

Iizuka, Toshiro; Kikuchi, Daisuke; Yamada, Akihiro; Hoteya, Shu; Kajiyama, Yoshiaki; Kaise, Mitsuru

2014-11-20

355

On the role of calcium in indole-3-acetic acid movement and graviresponse in etiolated pea epicotyls  

NASA Technical Reports Server (NTRS)

To determine whether Ca2+ plays a special role in the early graviresponse of shoots, as has been reported for roots, we treated etiolated pea epicotyls with substances known to antagonize Ca2+ (La3+), to remove Ca2+ from the wall (spermidine, EGTA), to inhibit calmodulin mediated reactions (chlorpromazine), or to inhibit IAA transport (TIBA). We studied the effect of these substances on IAA and Ca2+ uptake into 7 mm long subapical 3rd internode etiolated pea epicotyl sections and pea leaf protoplasts, on pea epicotyl growth, and graviresponse and on lateral IAA redistribution during gravistimulation. Our results support the view that adequate Ca2+ in the apoplast is required for normal IAA uptake, transport and graviresponse. Experiments with protoplasts indicate that Ca2+ may be controlling a labile membrane porter, possibly located on the external surface of cell membrane, while inhibitor experiments suggest that calmodulin is also implicated in both the movement of IAA and graviresponse. Since a major transfer of Ca2+ through free space during graviresponse has not yet been demonstrated, and since inhibition of calcium channels does not affect IAA redistribution (Migliaccio and Galston, 1987, Plant Physiology 85:542), we conclude that no clear evidence links prior Ca2+ movement with IAA redistribution during graviresponse in stems.

Migliaccio, F.; Galston, A. W.

1989-01-01

356

Effects of different sources of fat (calcium soap of palm oil vs. extruded linseed) in lactating ewes' diet on the fatty acid profile of their suckling lambs.  

PubMed

The main objective of this study was to evaluate the effects of supplementing lactating ewe diets with extruded linseed on the fatty acid (FA) composition of intramuscular and subcutaneous fat depots of suckling lambs. Twenty-four pregnant Churra ewes were divided into two groups based on the milk production, age, body weight and parity, and assigned to one of two treatments. Each ewe of the Control treatment was supplemented with 70 g/day of FAs from a calcium soap of palm oil, while the other treatment group (Lin) was supplemented with 128 g/day of extruded linseed. All lambs were reared exclusively on milk and were slaughtered when they reached 11 kg live weight. FA profiles of ewe milk, lamb meat and subcutaneous adipose tissue were determined by GC. Lamb performance was not affected by the treatments. Muscle fat and adipose tissue from the Lin treatment showed higher proportions of polyunsaturated fatty acids (PUFA). The percentages of ?-linolenic (C18:3 n-3), docosahexaenoic (C22:6 n-3), vaccenic (trans-11 C18:1) and rumenic (cis-9, trans-11 C18:2) acids in both fat depots were higher in Lin than in Control suckling lambs. Furthermore, meat fat from Lin carcasses displayed a lower n-6/n-3 ratio than Control samples. Intramuscular depots clearly showed a greater content of PUFA, including cis-9, trans-11 C18:2, and a lower n-6/n-3 ratio than subcutaneous fat. The results from this study demonstrate that dietary extruded linseed supplementation of lactating ewes enhances the nutritional quality of suckling lamb fat depots such as intramuscular and subcutaneous fats. PMID:24334053

Gómez-Cortés, P; Gallardo, B; Mantecón, A R; Juárez, M; de la Fuente, M A; Manso, T

2014-03-01

357

Sensitivity analyses of MAGIC modelled predictions of future impacts of whole-tree harvest on soil calcium supply and stream acid neutralizing capacity.  

PubMed

Forest biofuel is a main provider of energy in Sweden and the market is expected to grow even further in the future. Removal of logging residues via harvest can lead to short-term acidification but the long-term effects are largely unknown. The objectives of this study were to 1) model the long-term effect of whole-tree harvest (WTH) on soil and stream water acidity and 2) perform sensitivity analyses by varying the amounts of logging residues, calcium (Ca(2+)) concentrations in tree biomass and site productivity in nine alternate scenarios. Data from three Swedish forested catchments and the Model of Acidification of Groundwater in Catchments (MAGIC) were used to simulate changes in forest soil exchangeable Ca(2+) pools and stream water acid neutralizing capacity (ANC) at Gammtratten, Kindla and Aneboda. Large depletions in soil Ca(2+) supply and a reversal of the positive trend in stream ANC were predicted for all three sites after WTH. However, the magnitude of impact on stream ANC varied depending on site and the concentration of mobile strong acid anions. Contrary to common beliefs, the largest decrease in modelled ANC was observed at the well-buffered site Gammtratten. The effects at Kindla and Aneboda were much more limited and not large enough to offset the general recovery from acidification. Varying the tree biomass Ca(2+) concentrations exerted the largest impact on modelled outcome. Site productivity was the second most important variable whereas changing biomass amounts left on site only marginally affected the results. The outcome from the sensitivity analyses pointed in the same direction of change as in the base scenario, except for Kindla where soil Ca(2+) pools were predicted to be replenished under a given set of input data. The reliability of modelled outcome would increase by using site-specific Ca(2+) concentrations in tree biomass and field determined identification of site productivity. PMID:25046610

Zetterberg, Therese; Köhler, Stephan J; Löfgren, Stefan

2014-10-01

358

Oral calcium carbonate affects calcium but not phosphorus balance in stage 3–4 chronic kidney disease  

PubMed Central

Chronic kidney disease (CKD) patients are given calcium carbonate to bind dietary phosphorus and reduce phosphorus retention, and to prevent negative calcium balance. Data are limited on calcium and phosphorus balance in CKD to support this. The aim of this study was to determine calcium and phosphorus balance and calcium kinetics with and without calcium carbonate in CKD patients. Eight stage 3/4 CKD patients, eGFR 36 mL/min, participated in two 3-week balances in a randomized placebo-controlled cross-over study of calcium carbonate (1500 mg/d calcium). Calcium and phosphorus balance were determined on a controlled diet. Oral and intravenous 45calcium with blood sampling and urine and fecal collections were used for calcium kinetics. Fasting blood and urine were collected at baseline and end of each week of each balance period for biochemical analyses. Results showed that patients were in neutral calcium and phosphorus balance while on placebo. Calcium carbonate produced positive calcium balance, did not affect phosphorus balance, and produced only a modest reduction in urine phosphorus excretion compared with placebo. Calcium kinetics demonstrated positive net bone balance but less than overall calcium balance suggesting tissue deposition. Fasting biochemistries of calcium and phosphate homeostasis were unaffected by calcium carbonate. If they can be extrapolated to effects of chronic therapy, these data caution against the use of calcium carbonate as a phosphate binder. PMID:23254903

Hill, Kathleen M.; Martin, Berdine R.; Wastney, Meryl; McCabe, George P.; Moe, Sharon M.; Weaver, Connie M.; Peacock, Munro

2014-01-01

359

Effect of replacing calcium salts of palm oil distillate with incremental amounts of conventional or high oleic acid milled rapeseed on milk fatty acid composition in cows fed maize silage-based diets.  

PubMed

Based on potential benefits to human health, there is increasing interest in altering the composition of ruminant-derived foods. Including rapeseeds in the dairy cow diet is an effective strategy for replacing medium-chain saturated fatty acids (SFA) with cis-monounsaturated fatty acids (MUFA) in bovine milk, but there is limited information on the optimum level of supplementation. Decreases in SFA due to plant oils are also accompanied by increases in milk trans fatty acid (FA) content and it is possible that high oleic acid rapeseeds may result in a higher enrichment of cis-9 18:1 and lower increases in trans FAs in milk compared with conventional varieties. Seven multiparous lactating Holstein-Friesian cows were allocated to one of seven treatments in an incomplete Latin square design with five 28-day experimental periods, to evaluate the effect of replacing calcium salts of palm oil distillate (CPO; 41 g/kg diet dry matter, DM) with 128, 168 or 207 g/kg diet DM of conventional (COR) or a high oleic acid (HOR) rapeseed fed as a supplement milled with wheat. Rapeseed variety and inclusion level had no effect (P > 0.05) on DM intake, milk yield and composition. Both rapeseed varieties decreased linearly (P < 0.001) milk fat SFA content, which was partially compensated for by a linear increase (P < 0.001) in cis-9 18:1 concentration. Reductions in milk SFA were also associated with increases (P < 0.05) in trans 18:1 and total trans FA content, with no difference (P > 0.05) between rapeseed varieties. Replacing CPO in the diet with milled rapeseeds had no effect (P > 0.05) on total milk conjugated linoleic acid (CLA) concentration. Relative to a COR, inclusion of a high oleic acid variant in the diet increased (P = 0.01) the ratio of trans-MUFA : trans-polyunsaturated fatty acids in milk that may have implications with respect to cardiovascular disease risk in humans. In conclusion, data indicated that replacing CPO with milled rapeseeds at levels up to 1150 g oil/day could be used as a nutritional strategy to lower milk SFA content without inducing adverse effects on DM intake and milk production. HOR reduced milk fat SFA content to a greater extent than a conventional variety, but did not minimise associated increases in trans FA concentrations. However, the high oleic acid variant did alter the relative abundance of specific trans 18:1, CLA and trans 18:2 isomers compared with conventional rapeseeds. PMID:22440184

Kliem, K E; Shingfield, K J; Humphries, D J; Givens, D I

2011-06-01

360

Eicosapentaenoic acid free fatty acid prevents and suppresses colonic neoplasia in colitis-associated colorectal cancer acting on Notch signaling and gut microbiota.  

PubMed

Inflammatory bowel diseases are associated with increased risk of developing colitis-associated colorectal cancer (CAC). Epidemiological data show that the consumption of ?-3 polyunsaturated fatty acids (?-3 PUFAs) decreases the risk of sporadic colorectal cancer (CRC). Importantly, recent data have shown that eicosapentaenoic acid-free fatty acid (EPA-FFA) reduces polyp formation and growth in models of familial adenomatous polyposis. However, the effects of dietary EPA-FFA are unknown in CAC. We tested the effectiveness of substituting EPA-FFA, for other dietary fats, in preventing inflammation and cancer in the AOM-DSS model of CAC. The AOM-DSS protocols were designed to evaluate the effect of EPA-FFA on both initiation and promotion of carcinogenesis. We found that EPA-FFA diet strongly decreased tumor multiplicity, incidence and maximum tumor size in the promotion and initiation arms. Moreover EPA-FFA, in particular in the initiation arm, led to reduced cell proliferation and nuclear ?-catenin expression, whilst it increased apoptosis. In both arms, EPA-FFA treatment led to increased membrane switch from ?-6 to ?-3 PUFAs and a concomitant reduction in PGE2 production. We observed no significant changes in intestinal inflammation between EPA-FFA treated arms and AOM-DSS controls. Importantly, we found that EPA-FFA treatment restored the loss of Notch signaling found in the AOM-DSS control and resulted in the enrichment of Lactobacillus species in the gut microbiota. Taken together, our data suggest that EPA-FFA is an excellent candidate for CRC chemoprevention in CAC. PMID:24676631

Piazzi, Giulia; D'Argenio, Giuseppe; Prossomariti, Anna; Lembo, Vincenzo; Mazzone, Giovanna; Candela, Marco; Biagi, Elena; Brigidi, Patrizia; Vitaglione, Paola; Fogliano, Vincenzo; D'Angelo, Leonarda; Fazio, Chiara; Munarini, Alessandra; Belluzzi, Andrea; Ceccarelli, Claudio; Chieco, Pasquale; Balbi, Tiziana; Loadman, Paul M; Hull, Mark A; Romano, Marco; Bazzoli, Franco; Ricciardiello, Luigi

2014-11-01

361

Salvianolic Acid A, a Novel Matrix Metalloproteinase-9 Inhibitor, Prevents Cardiac Remodeling in Spontaneously Hypertensive Rats  

PubMed Central

Cardiac fibrosis is a deleterious consequence of hypertension which may further advance to heart failure and increased matrix metalloproteinase-9 (MMP-9) contributes to the underlying mechanism. Therefore, new therapeutic strategies to attenuate the effects of MMP-9 are urgently needed. In the present study, we characterize salvianolic acid A (SalA) as a novel MMP-9 inhibitor at molecular, cellular and animal level. We expressed a truncated form of MMP-9 which contains only the catalytic domain (MMP-9 CD), and used this active protein for enzymatic kinetic analysis and Biacore detection. Data generated from these assays indicated that SalA functioned as the strongest competitive inhibitor of MMP-9 among 7 phenolic acids from Salvia miltiorrhiza. In neonatal cardiac fibroblast, SalA inhibited fibroblast migration, blocked myofibroblast transformation, inhibited secretion of intercellular adhesion molecule (ICAM), interleukin-6 (IL-6) and soluble vascular cell adhesion molecule-1 (sVCAM-1) as well as collagen induced by MMP-9 CD. Functional effects of SalA inhibition on MMP-9 was further confirmed in cultured cardiac H9c2 cell overexpressing MMP-9 in vitro and in heart of spontaneously hypertensive rats (SHR) in vivo. Moreover, SalA treatment in SHR resulted in decreased heart fibrosis and attenuated heart hypertrophy. These results indicated that SalA is a novel inhibitor of MMP-9, thus playing an inhibitory role in hypertensive fibrosis. Further studies to develop SalA and its analogues for their potential clinical application of cardioprotection are warranted. PMID:23533637

Deng, Yanping; Teng, Fukang; Chen, Jing; Xue, Song; Kong, Xiangqian; Luo, Cheng; Shen, Xu; Jiang, Hualiang; Xu, Feng; Yang, Wengang; Yin, Jun; Wang, Yanhui; Chen, Hui; Wu, Wanying; Liu, Xuan; Guo, De-an

2013-01-01

362

Dietary omega-3 alpha-linolenic acid does not prevent venous thrombosis in mice.  

PubMed

Venous thromboembolism (VTE) is a leading cause of cardiovascular death. Omega-3 fatty acids (n-3 FA) exhibit protective effects against cardiovascular disease. Others and our group have reported that the plant-derived n-3 FA alpha-linolenic acid (ALA) displays antiinflammatory, anticoagulant and antiplatelet effects, thereby reducing atherosclerosis and arterial thrombosis in mice fed a high ALA diet. Since procoagulant factors such as tissue factor and fibrin as well as platelets and leukocytes are crucially involved in the development of VTE, we investigated possible protective effects of dietary ALA on venous thrombus formation in a mouse model of stenosis- and furthermore, in a mouse model of endothelial injury-induced venous thrombosis. Four week old C57BL/6 mice underwent four weeks of high (7.3g%) or low ALA (0.03g%) treatment before being exposed to inferior vena cava (IVC) stenosis for 48 hours or laser injury of the endothelium of the internal jugular vein (IJV). Thrombus generation frequency, thrombus size and composition (IVC stenosis group) and time to thrombus formation (endothelial injury group) were assessed. In addition, plasma glycocalicin, a marker of platelet activation, platelet P-selectin and activated integrin expression as well as plasma thrombin generation was determined, but did not reveal any significant differences between the groups. Despite its protective properties against arterial thrombus formation, dietary ALA did not protect against venous thrombosis neither in the IVC stenosis nor the endothelial injury model, further indicating that the biological processes involved in arterial and venous thrombosis are different. PMID:25231375

Reiner, M F; Martinod, K; Stivala, S; Savarese, G; Camici, G G; Lüscher, T F; Wagner, D D; Beer, J H

2015-01-01

363

Sinapic Acid Prevents Hypertension and Cardiovascular Remodeling in Pharmacological Model of Nitric Oxide Inhibited Rats  

PubMed Central

Objectives Hypertensive heart disease is a constellation of abnormalities that includes cardiac fibrosis in response to elevated blood pressure, systolic and diastolic dysfunction. The present study was undertaken to examine the effect of sinapic acid on high blood pressure and cardiovascular remodeling. Methods An experimental hypertensive animal model was induced by L-NAME intake on rats. Sinapic acid (SA) was orally administered at a dose of 10, 20 and 40 mg/kg body weight (b.w.). Blood pressure was measured by tail cuff plethysmography system. Cardiac and vascular function was evaluated by Langendorff isolated heart system and organ bath studies, respectively. Fibrotic remodeling of heart and aorta was assessed by histopathologic analyses. Oxidative stress was measured by biochemical assays. mRNA and protein expressions were assessed by RT-qPCR and western blot, respectively. In order to confirm the protective role of SA on endothelial cells through its antioxidant property, we have utilized the in vitro model of H2O2-induced oxidative stress in EA.hy926 endothelial cells. Results Rats with hypertension showed elevated blood pressure, declined myocardial performance associated with myocardial hypertrophy and fibrosis, diminished vascular response, nitric oxide (NO) metabolites level, elevated markers of oxidative stress (TBARS, LOOH), ACE activity, depleted antioxidant system (SOD, CAT, GPx, reduced GSH), aberrant expression of TGF-?, ?-MHC, eNOS mRNAs and eNOS protein. Remarkably, SA attenuated high blood pressure, myocardial, vascular dysfunction, cardiac fibrosis, oxidative stress and ACE activity. Level of NO metabolites, antioxidant system, and altered gene expression were also repaired by SA treatment. Results of in vitro study showed that, SA protects endothelial cells from oxidative stress and enhance the production of NO in a concentration dependent manner. Conclusions Taken together, these results suggest that SA may have beneficial role in the treatment of hypertensive heart disease by attenuating fibrosis and oxidative stress through its antioxidant potential. PMID:25531679

Silambarasan, Thangarasu; Manivannan, Jeganathan; Krishna Priya, Mani; Suganya, Natarajan; Chatterjee, Suvro; Raja, Boobalan

2014-01-01

364

Sperm Abnormalities in Heterozygous Acid Sphingomyelinase Knockout Mice Reveal a Novel Approach for the Prevention of Genetic Diseases  

PubMed Central

Acid sphingomyelinase knockout mice are a model of the inherited human disorder types A and B Niemann-Pick disease. Herein, we show that heterozygous (ASMKO+/?) mice have two distinct sperm populations resembling those found in normal and mutant animals, respectively, and that these two populations could be distinguished by their morphology, ability to undergo capacitation or the acrosome reaction, and/or mitochondrial membrane potential (MMP). The abnormal morphology of the mutant sperm could be normalized by demembranation with detergents or by the addition of recombinant acid sphingomyelinase to the culture media, and the corrected sperm also had an enhanced fertilization capacity. Methods were then explored to enrich for normal sperm from the mixed ASMKO+/? population, and flow cytometric sorting based on MMP provided the best results. In vitro fertilization was performed using ASMKO+/? oocytes and sperm before and after MMP sorting, and it was found that the sorted sperm produced significantly more wild-type pups than nonsorted sperm. Sperm sorting is much less invasive and more cost-effective than egg isolation, and offers several advantages over the existing assisted reproduction options for Niemann-Pick disease carrier couples. It therefore could have a major impact on the prevention of this and perhaps other genetic diseases. PMID:17525274

Butler, Avigdor; Gordon, Ronald E.; Gatt, Shimon; Schuchman, Edward H.

2007-01-01

365

9-Anthracene carboxylic acid is more suitable than DIDS for characterization of calcium-activated chloride current during canine ventricular action potential.  

PubMed

Understanding the role of ionic currents in shaping the cardiac action potential (AP) has great importance as channel malfunctions can lead to sudden cardiac death by inducing arrhythmias. Therefore, researchers frequently use inhibitors to selectively block a certain ion channel like 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) and 9-anthracene carboxylic acid (9-AC) for calcium-activated chloride current (ICl(Ca)). This study aims to explore which blocker is preferable to study ICl(Ca). Whole-cell voltage-clamp technique was used to record ICa,L, IKs, IKr and IK1, while action potentials were measured using sharp microelectrodes. DIDS- (0.2 mM) and 9-AC-sensitive (0.5 mM) currents were identical in voltage-clamp conditions, regardless of intracellular Ca(2+) buffering. DIDS-sensitive current amplitude was larger with the increase of stimulation rate and correlated well with the rate-induced increase of calcium transients. Both drugs increased action potential duration (APD) to the same extent, but the elevation of the plateau potential was more pronounced with 9-AC at fast stimulation rates. On the contrary, 9-AC did not influence either the AP amplitude or the maximal rate of depolarization (V max), but DIDS caused marked reduction of V max. Both inhibitors reduced the magnitude of phase-1, but, at slow stimulation rates, this effect of DIDS was larger. All of these actions on APs were reversible upon washout of the drugs. Increasing concentrations of 9-AC between 0.1 and 0.5 mM in a cumulative manner gradually reduced phase-1 and increased APD. 9-AC at 1 mM had no additional actions upon perfusion after 0.5 mM. The half-effective concentration of 9-AC was approximately 160 ?M with a Hill coefficient of 2. The amplitudes of ICa,L, IKs, IKr and IK1 were not changed by 0.5 mM 9-AC. These results suggest that DIDS is equally useful to study ICl(Ca) during voltage-clamp but 9-AC is superior in AP measurements for studying the physiological role of ICl(Ca) due to the lack of sodium channel inhibition. 9-AC has also no action on other ion currents (ICa,L, IKr, IKs, IK1); however, ICa,L tracings can be contaminated with ICl(Ca) when measured in voltage-clamp condition. PMID:25344201

Váczi, Krisztina; Hegyi, Bence; Ruzsnavszky, Ferenc; Kistamás, Kornél; Horváth, Balázs; Bányász, Tamás; Nánási, Péter P; Szentandrássy, Norbert; Magyar, János

2014-10-26

366

Measurement of total calcium by flash chronopotentiometry at polymer membrane ion-selective electrodes.  

PubMed

Ionophore-based ion-selective electrodes are widely used for potentiometric electrolyte measurements, in which case they are known to detect the free ion activity. Total ion concentrations cannot be directly assessed by this methodology if the ion is predominantly present in a complexed form. We present here the direct measurement of total calcium using a calcium ion-selective electrode interrogated in a flash chronopotentiometric transduction mode. A high magnitude of cathodic current pulse is applied across a calcium ion-selective membrane containing the ionophore ETH 5234 but void of ion-exchanger to prevent spontaneous extraction. This induces a defined flux of calcium ions from the sample side to the membrane and results in the release of labile bound calcium and a concomitant depletion at the membrane surface at a critical current or time. This is observed as an inflection point on the potential-time curve and the square root of the transition time is linearly related to the total concentration in the sample. It is shown that the responses to solutions of labile calcium complexes of nitrilotriacetic acid (NTA) are in a good agreement with that of the same concentration of calcium chloride in saline solution with this protocol. Initial applications are aimed towards assaying extracellular calcium. Calcium binding to albumin is shown to be inconsequential with sample dilutions typical for clinical assays. Calcium calibration curves in real and artificial dilute serum are finally shown to correspond to that of calcium chloride, suggesting that the methodology is indeed capable of detecting total calcium under these conditions. The present membrane materials allow detection of up to over 0.5mM total calcium in serum, currently requiring such samples to be diluted about 5-fold. The slopes of the square root of time-concentration dependence for the calibrations of free calcium in a background of NaCl and total serum calcium were found to be 3.857 and 3.717 s(1/2)mM(-1), respectively, deviating by just 3.6%. The lower detection limit (3x SD) was calculated as 12 microM. PMID:19646590

Gemene, Kebede L; Bakker, Eric

2009-08-26

367

In vitro digestion testing of lipid-based delivery systems: calcium ions combine with fatty acids liberated from triglyceride rich lipid solutions to form soaps and reduce the solubilization capacity of colloidal digestion products.  

PubMed

In vitro digestion testing is of practical importance to predict the fate of drugs administered in lipid-based delivery systems. Calcium ions are often added to digestion media to increase the extent of digestion of long-chain triglycerides (LCTs), but the effects they have on phase behaviour of the products of digestion, and consequent drug solubilization, are not well understood. This study investigates the effect of calcium and bile salt concentrations on the rate and extent of in vitro digestion of soybean oil, as well as the solubilizing capacity of the digestion products for two poorly water-soluble drugs, fenofibrate and danazol. In the presence of higher concentrations of calcium ions, the solubilization capacities of the digests were reduced for both drugs. This effect is attributed to the formation of insoluble calcium soaps, visible as precipitates during the digestions. This reduces the availability of liberated fatty acids to form mixed micelles and vesicles, thereby reducing drug solubilization. The use of high calcium concentrations does indeed force in vitro digestion of LCTs but may overestimate the extent of drug precipitation that occurs within the intestinal lumen. PMID:23178598

Devraj, Ravi; Williams, Hywel D; Warren, Dallas B; Mullertz, Anette; Porter, Christopher J H; Pouton, Colin W

2013-01-30

368

Differential Responses of Abaxial and Adaxial Guard Cells of Broad Bean to Abscisic Acid and Calcium1  

Microsoft Academic Search

Regulation by abscisic acid (ABA) and Ca21 of broad bean (Vicia faba) abaxial and adaxial guard cell movements and inward K1 currents were compared. One millimolar Ca21 in the bathing me- dium inhibited abaxial stomatal opening by 60% but only inhibited adaxial stomatal opening by 15%. The addition of 1 mM ABA in the bathing medium resulted in 80% inhibition

Xi-Qing Wang; Wei-Hua Wu; Sarah M. Assmann

1998-01-01

369

Influence of Prilled Fat and Calcium Salt of Palm Oil Fatty Acids on Ruminal Fermentation and Nutrient Digestibility1  

Microsoft Academic Search

Four rumen cannulated Holstein cows were used in a Latin square design to examine the effect of supplemental cal- cium salt of palm oil fatty acids (.68 kg\\/d) or prilled fat (.68 or .91 kg\\/d) on DM intake, rumen fermentation, and nutrient digestibility. Basal diet con- tained 45% concentrate, 27.5% alfalfa silage, and 27.5% corn silage (DM basis), and treatments

Ric R. Grummer

1988-01-01

370

The effect of conjugated linoleic acid on calcium absorption and bone metabolism and composition in adult ovariectomised rats  

Microsoft Academic Search

The effect of conjugated linoleic acid (CLA) on postmenopausal bone metabolism has not been investigated. Therefore, forty-three adult ovariectomised (OVX) rats (8–9 rats per group) were fed either a control diet containing 40g\\/kg soyabean oil (SBO diet) or the SBO diet with 0 (control OVX), 2.5, 5 or 10g\\/kg of CLA (replacing soybean oil) for 9 weeks. A group of

O. Kelly; K. D. Cashman

2004-01-01

371

Alterations of concentrations of calcium and arachidonic acid and agglutinations of microfilaments in host cells during Toxoplasma gondii invasion  

Microsoft Academic Search

Toxoplasma gondii (T. gondii) invasion of host cells is a complicated process of interaction between parasites and host cells. In the present study we investigated the alterations of free Ca2+ concentration ([Ca2+]i) and cytoskeletons in phagocytic and non-phagocytic host cells and arachidonic acid (AA) concentration in cells supernatant during T. gondii invasion. T. gondii invasion induced significant elevation of intracellular

Liwei Li; Xunde Li; Jie Yan

2008-01-01

372

Abscisic Acid Induces Oscillations in Guard-Cell Cytosolic Free Calcium That Involve Phosphoinositide-Specific Phospholipase C  

Microsoft Academic Search

Oscillations in cytosolic free Ca2+ concentration ([Ca2+]cyt) are an important component of Ca2+-based signal transduction pathways. This fact has led us to investigate whether oscillations in [Ca2+]cyt are involved in the response of stomatal guard cells to the plant hormone abscisic acid (ABA). We show that ABA induces oscillations in guard-cell [Ca2+]cyt. The pattern of the oscillations depended on the

Irina Staxen; Christophe Pical; Lucy T. Montgomery; Julie E. Gray; Alistair M. Hetherington; Martin R. McAinsh

1999-01-01

373

Calcium Additions and Microbial Nitrogen Cycle Processes in a  

E-print Network

Calcium Additions and Microbial Nitrogen Cycle Processes in a Northern Hardwood Forest Peter M to replace calcium (Ca) leached from the ecosystem by acid deposition over the past 6 decades. Soil microbial- posals to mitigate the depletion of nutrient cations in soil. Key words: acid deposition; calcium; carbon

Berkowitz, Alan R.

374

Effect of calcium ion (cross-linker) concentration on porosity, surface morphology and thermal behavior of calcium alginates prepared from algae ( Undaria pinnatifida)  

Microsoft Academic Search

Alginic acid and metal (sodium) alginates was prepared from fresh algae using hot extraction method. Calcium alginates are also prepared from sodium alginate by varying calcium ion (calcium chloride) concentrations. FTIR spectra indicate that alginic acid is converted into metal alginate. Surface morphology as well as total intrusion volume, porosity (%) and pore size distribution changes by changing calcium ion

Tara Sankar Pathak; Jung-Ho Yun; Joonbae Lee; Ki-Jung Paeng

2010-01-01

375

Prevention of Surgical Site Infection After Open Prosthetic Inguinal Hernia Repair: Efficacy of Parenteral Versus Oral Prophylaxis with Amoxicillin-Clavulanic Acid in a Randomized Clinical Trial  

Microsoft Academic Search

The aim of this prospective study was to compare the efficacy of oral versus parenteral prophylactic amoxicillin–clavulanic acid for preventing surgical site infection after open prosthetic mesh repair of inguinal hernia. A total of 480 inguinal-hernia patients were randomly assigned to two groups. Group I (n = 240) received 1.313 g oral amoxicillin–clavulanic acid 2 hours before operation, and group

Mehmet A. Kuzu; Selçuk Hazinedaro?lu; ?ükrü Dolalan; Nam?k Özkan; Samet Yalç?n; A. Bülent Erkek; Hatem Mahmoudi; Acar Tüzüner; Atilla H. Elhan; Ercümet Kuterdem

2005-01-01

376

Roles of arachidonic acid, lipoxygenases and phosphatases in calcium-dependent modulation of M-current in bullfrog sympathetic neurons.  

PubMed Central

1. M-current (IM) is regulated by intracellular free Ca2+ ([Ca2+]i). Suppression and overrecovery of IM induced by muscarine and luteinizing-hormone releasing hormone (LHRH) are also regulated by [Ca2+]i. The role of the arachidonic acid (AA) pathway in the Ca(2+)-dependent modulation of IM was investigated using whole-cell voltage clamp and intracellular perfusion in dissociated bullfrog sympathetic B neurons. 2. Quinacrine (10-20 microM) and 4-bromophenacyl bromide (4-BPB; 4-10 microM), the inhibitors of phospholipase A2, blocked the enhancement of IM evoked by raising [Ca2+]i. 3. AA (6-120 microM) increased IM by about 50% of the control current in a Ca(2+)-dependent manner. 4. Enhancements of IM by Ca2+ and AA were blocked by the lipoxygenase (LO) inhibitors nordihydroguaiaretic acid (NDGA; 1-5 microM) and 5,8,11-eicosatrynoic acid (ETI; 10 microM). The cyclo-oxygenase inhibitor indomethacin (10 microM) had no effect. 5. Enhancement of IM by Ca2+ was abolished by the selective 12-LO inhibitors baicalein (1-2 microM) and 15(S)-hydroxy-5-cis-8-cis-11-cis-13-trans-eicosatetraenoic acid (15-HETE; 6.5 microM). A 12-LO product, 2(S)-hydroxy-5-cis-8-cis-10-trans-14-cis- eicosatetraenoic acid (12-HETE; 13-20 microM), increased IM without Ca2+ requirement. 6. Enhancement of IM by Ca2+ was not affected by the selective 5-LO inhibitors AA-861 (10 microM), 5,6-dehydroarachidonic acid (5,6-DAA, 10 microM) and L-651,896 (10 microM). The 5-LO metabolites leukotriene C4 (1.5-8 microM) and leukotriene B4 (1.5-5 microM) showed no obvious effect on IM. 7. NDGA alone inhibited IM with an IC50 of 0.73 microM at 120 nM Cai(2+). 8. NDGA did not affect suppression of IM by muscarine or LHRH; however, overrecovery of IM upon removing these agonists was totally eliminated by 1 microM NDGA. 9. Inhibitors of phosphatases, calyculin A (0.1 microM) and okadaic acid (1 microM), completely abolished overrecovery of IM. Calyculin A also blocked the Ca(2+)-induced IM enhancement. 10. It is suggested that Ca2+ enhances IM by stimulating the AA metabolic pathway. Dephosphorylation probably upregulates IM. Overrecovery of IM is probably a result of stimulation of the LO pathway and phosphatases by increased [Ca2+]i. Images Figure 3 Figure 4 Figure 8 Figure 9 PMID:8544140

Yu, S P

1995-01-01

377

Fusarium Head Blight Control and Prevention of Mycotoxin Contamination in Wheat with Botanicals and Tannic Acid  

PubMed Central

Suspensions or solutions with 1% of Chinese galls (Galla chinensis, GC) or 1% of tannic acid (TA), inhibited germination of conidia or mycelium growth of Fusarium graminearum (FG) by 98%–100% or by 75%–80%, respectively, whereas dried bark from buckthorn (Frangula alnus, FA) showed no effect at this concentration. In climate chamber experiments where the wheat variety “Apogee” was artificially inoculated with FG and F. crookwellense (FCr) and treated with 5% suspensions of TA, GC and FA, the deoxynivalenol (DON) content in grains was reduced by 81%, 67% and 33%, respectively. In field experiments with two commercial wheat varieties and artificial or semi-natural inoculations, mean DON reductions of 66% (TA) and 58% (FA), respectively, were obtained. Antifungal toxicity can explain the high efficacies of TA and GC but not those of FA. The Fusarium head blight (FHB) and mycotoxin reducing effect of FA is probably due to elicitation of resistance in wheat plants. With semi-natural inoculation, a single FA application in the first half of the flowering period performed best. However, we assume that applications of FA at the end of ear emergence and a treatment, triggered by an infection period, with TA or GC during flowering, might perform better than synthetic fungicides. PMID:24577585

Forrer, Hans-Rudolf; Musa, Tomke; Schwab, Fabienne; Jenny, Eveline; Bucheli, Thomas D.; Wettstein, Felix E.; Vogelgsang, Susanne

2014-01-01

378

The FXR Agonist Obeticholic Acid Prevents Gut Barrier Dysfunction and Bacterial Translocation in Cholestatic Rats.  

PubMed

Bacterial translocation (BTL) drives pathogenesis and complications of cirrhosis. Farnesoid X-activated receptor (FXR) is a key transcription regulator in hepatic and intestinal bile metabolism. We studied potential intestinal FXR dysfunction in a rat model of cholestatic liver injury and evaluated effects of obeticholic acid (INT-747), an FXR agonist, on gut permeability, inflammation, and BTL. Rats were gavaged with INT-747 or vehicle during 10 days after bile-duct ligation and then were assessed for changes in gut permeability, BTL, and tight-junction protein expression, immune cell recruitment, and cytokine expression in ileum, mesenteric lymph nodes, and spleen. Auxiliary in vitro BTL-mimicking experiments were performed with Transwell supports. Vehicle-treated bile duct-ligated rats exhibited decreased FXR pathway expression in both jejunum and ileum, in association with increased gut permeability through increased claudin-2 expression and related to local and systemic recruitment of natural killer cells resulting in increased interferon-? expression and BTL. After INT-747 treatment, natural killer cells and interferon-? expression markedly decreased, in association with normalized permeability selectively in ileum (up-regulated claudin-1 and occludin) and a significant reduction in BTL. In vitro, interferon-? induced increased Escherichia coli translocation, which remained unaffected by INT-747. In experimental cholestasis, FXR agonism improved ileal barrier function by attenuating intestinal inflammation, leading to reduced BTL and thus demonstrating a crucial protective role for FXR in the gut-liver axis. PMID:25592258

Verbeke, Len; Farre, Ricard; Verbinnen, Bert; Covens, Kris; Vanuytsel, Tim; Verhaegen, Jan; Komuta, Mina; Roskams, Tania; Chatterjee, Sagnik; Annaert, Pieter; Elst, Ingrid Vander; Windmolders, Petra; Trebicka, Jonel; Nevens, Frederik; Laleman, Wim

2015-02-01

379

Role of Hyaluronic Acid Treatment in the Prevention of Keloid Scarring  

PubMed Central

Background Keloids are benign dermal scars characterized by enhanced growth factor signaling, hyperproliferation activity and reduced extracellular matrix (ECM) deposition of hyaluronic acid. Our hypothesis is that high molecular weight HA can be used to replenish HA deposition in keloids thereby normalizing the keloid fibroblast phenotype. Methods One normal (NF1) fibroblast culture and five keloid (KF1, KF2, KF3, KF4, KF5) fibroblast cultures were analyzed for changes in hyperproliferation, growth factor production and extracellular matrix deposition following 72 hour treatment with or without 10 ?g/ml HA. Results Proliferation activity decreased significantly in KF3 following HA treatment. Pro-collagen I expression in KF2 was decreased following HA treatment in association with changes in fiber arrangement to more parallel collagen bundles. In addition, HA demonstrated a downregulation on TGF-b1 growth factor expression in KF3 and KF4 and a decrease in active TGF-b1 release in KF2 and KF5 using ELISA. Conclusion Our data demonstrates that HA has the potential to normalize keloid fibroblast characteristic features such as hyperproliferation, growth factor production and ECM deposition depending on the specific genotype of the keloid fibroblast cell line. This study suggests that high molecular weight HA can be used to replenish HA deposition in keloid fibroblasts thereby decreasing fibrosis and ultimately decreasing keloid manifestation. PMID:24936445

Hoffmann, Andrea; Hoing, Jessica Lynn; Newman, Mackenzie; Simman, Richard

2013-01-01

380

Calcium - ionized  

MedlinePLUS

... before the test. Many medicines can interfere with blood test results. Your health care provider will tell you if ... decrease total calcium levels. These may include abnormal blood levels of albumin or immunoglobulins.

381

Comparative stability of the bioresorbable ferric crosslinked hyaluronic acid adhesion prevention solutions.  

PubMed

The Intergel® ferric crosslinked hyaluronate (FeHA) adhesion prevention solution (APS) (FDA) is associated with serious post-operative complications (Henley, http://www.lawyersandsettlements.com/features/gynecare-intergel/intergel-timeline.html, 2007; FDA, 2003; Roman et al., Fertil Steril 2005, 83 Suppl 1:1113-1118; Tang et al., Ann Surg 2006;243(4):449-455; Wiseman, Fertil Steril 2006;86(3):771; Wiseman, Fertil Steril 2006;85(4):e7). This prompted us to examine the in situ stability of crosslinked HA materials to hyaluronidase lyase degradation. Variables such as ferric ionic crosslink density, HA concentration, gel geometry, and molecular weight (MW) of HA polymer were studied. Various formulations of the crosslinked "in house" [Isayeva et al., J Biomed Mater Res: Part B - Appl Biomater 2010, 95B (1):9-18] FeHA (0.5%, w/v; 30, 50, 90% crosslinked), the Intergel® FeHA (0.5%, w/v; 90%), and the non-crosslinked HA (0.05-0.5%, w/v) were degraded at a fixed activity of hyaluronidase lyase from Streptomyces hyalurolyticus (Hyase) at 37°C over time according to the method [Payan et al., J Chrom B: Biomed Sci Appl 1991;566(1):9-18]. Under our conditions, the data show that the crosslink density affects degradation the most, followed by HA concentration and then gel geometry. We found that MW has no effect. Our results are one possible explanation of the observations that the Intergel® FeHA APS (0.5%, w/v; 90%) material persisted an order of magnitude longer than expected [t1/2 = 500 hrs vs. t1/2 = 50 hrs (FDA; Johns et al., Fertil Steril 1997;68(1):37-42)]. These data also demonstrate the sensitivity of the in vitro hyaluronidase assay to predict the in situ stability of crosslinked HA medical products as previously reported [Sall et al., Polym Degrad Stabil 2007;92(5):915-919]. PMID:23559362

Luu, Hoan-My Do; Chen, Angela; Isayeva, Irada S

2013-08-01

382

The Proteomic and Genomic Teratogenicity Elicited by Valproic Acid Is Preventable with Resveratrol and ?-Tocopherol  

PubMed Central

Background Previously, we reported that valproic acid (VPA), a common antiepileptic drug and a potent teratogenic, dowregulates RBP4 in chicken embryo model (CEM) when induced by VPA. Whether such teratogenicity is associated with more advanced proteomic and genomic alterations, we further performed this present study. Methodology/Principal Findings VPA (60 µM) was applied to 36 chicken embryos at HH stage 10 (day-1.5). Resveratrol (RV) and vitamin E (vit E) (each at 0.2 and 2.0 µM) were applied simultaneously to explore the alleviation effect. The proteins in the cervical muscles of the day-1 chicks were analyzed using 2D-electrophoresis and LC/MS/MS. While the genomics associated with each specific protein alteration was examined with RT-PCR and qPCR. At earlier embryonic stage, VPA downregulated PEBP1 and BHMT genes and at the same time upregulated MYL1, ALB and FLNC genes significantly (p<0.05) without affecting PKM2 gene. Alternatively, VPA directly inhibited the folate-independent (or the betaine-dependent) remethylation pathway. These features were effectively alleviated by RV and vit E. Conclusions VPA alters the expression of PEBP1, BHMT, MYL1, ALB and FLNC that are closely related with metabolic myopathies, myogenesis, albumin gene expression, and haemolytic anemia. On the other hand, VPA directly inhibits the betaine-dependent remethylation pathway. Taken together, VPA elicits hemorrhagic myoliposis via these action mechanisms, and RV and vit E are effective for alleviation of such adverse effects. PMID:25551574

Chen, Yeh; Lin, Ping-Xiao; Hsieh, Chiu-Lan; Peng, Chiung-Chi; Peng, Robert Y.

2014-01-01

383

Calcium Hydroxylapatite  

PubMed Central

Background: Calcium hydroxylapatite is one of the most well-studied dermal fillers worldwide and has been extensively used for the correction of moderate-to-severe facial lines and folds and to replenish lost volume. Objectives: To mark the milestone of 10 years of use in the aesthetic field, this review will consider the evolution of calcium hydroxylapatite in aesthetic medicine, provide a detailed injection protocol for a global facial approach, and examine how the unique properties of calcium hydroxylapatite provide it with an important place in today’s market. Methods: This article is an up-to-date review of calcium hydroxylapatite in aesthetic medicine along with procedures for its use, including a detailed injection protocol for a global facial approach by three expert injectors. Conclusion: Calcium hydroxylapatite is a very effective agent for many areas of facial soft tissue augmentation and is associated with a high and well-established safety profile. Calcium hydroxylapatite combines high elasticity and viscosity with an ability to induce long-term collagen formation making it an ideal agent for a global facial approach. PMID:25610523

Yutskovskaya, Yana Alexandrovna; Philip Werschler, WM.

2015-01-01

384

Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP)-mediated Calcium Signaling and Arrhythmias in the Heart Evoked by ?-Adrenergic Stimulation*?  

PubMed Central

Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most potent Ca2+-releasing second messenger known to date. Here, we report a new role for NAADP in arrhythmogenic Ca2+ release in cardiac myocytes evoked by ?-adrenergic stimulation. Infusion of NAADP into intact cardiac myocytes induced global Ca2+ signals sensitive to inhibitors of both acidic Ca2+ stores and ryanodine receptors and to NAADP antagonist BZ194. Furthermore, in electrically paced cardiac myocytes BZ194 blocked spontaneous diastolic Ca2+ transients caused by high concentrations of the ?-adrenergic agonist isoproterenol. Ca2+ transients were recorded both as increases of the free cytosolic Ca2+ concentration and as decreases of the sarcoplasmic luminal Ca2+ concentration. Importantly, NAADP antagonist BZ194 largely ameliorated isoproterenol-induced arrhythmias in awake mice. We provide strong evidence that NAADP-mediated modulation of couplon activity plays a role for triggering spontaneous diastolic Ca2+ transients in isolated cardiac myocytes and arrhythmias in the intact animal. Thus, NAADP signaling appears an attractive novel target for antiarrhythmic therapy. PMID:23564460

Nebel, Merle; Schwoerer, Alexander P.; Warszta, Dominik; Siebrands, Cornelia C.; Limbrock, Ann-Christin; Swarbrick, Joanna M.; Fliegert, Ralf; Weber, Karin; Bruhn, Sören; Hohenegger, Martin; Geisler, Anne; Herich, Lena; Schlegel, Susan; Carrier, Lucie; Eschenhagen, Thomas; Potter, Barry V. L.; Ehmke, Heimo; Guse, Andreas H.

2013-01-01

385

Effects of diet magnesium on acid-base status and calcium metabolism of dry cows fed acidogenic salts.  

PubMed

The objective was to study effects of dietary Mg on acid-base status and Ca metabolism of Holstein cows fed acidogenic diets with relatively high Ca concentrations. Eight nonlactating, nonpregnant Holstein cows were used in a switchback experiment with three 28-d periods. The normal Mg (.2%, dry basis) diet consisted of corn silage plus a concentrate mix supplemented with NH4Cl (126 g/d per cow) and (NH4)2SO4 (126 g/d per cow). The high Mg (.37%, dry basis) diet had MgSO4 substituted for an equivalent amount of S supplied by (NH4)2SO4 in the normal Mg diet. Cation-anion differences of the two diets were -302 (normal Mg) and -289 (high Mg) meq/kg of dietary DM. Compared with cows fed the normal Mg diet, those fed high Mg tended to have higher blood pH and plasma concentrations of total Ca but lower plasma concentrations of P and lower urinary excretion of ammonium and net acid. Cows fed the high Mg diet also tended to increase Mg excretion with a decrease in urinary excretion of Ca. Metabolic responses to intravenous infusion of Na2-EDTA were similar among cows fed either diet. Results indicate that increasing Mg intake of cows fed acidogenic salts was of no advantage with regard to Ca metabolism. PMID:1569272

Wang, C; Beede, D K

1992-03-01

386

The Calcium-mobilizing Messenger Nicotinic Acid Adenine Dinucleotide Phosphate Participates in Sperm Activation by Mediating the Acrosome Reaction*  

PubMed Central

Before a sperm can fertilize an egg it must undergo a final activation step induced by the egg termed the acrosome reaction. During the acrosome reaction a lysosome-related organelle, the acrosome, fuses with the plasma membrane to release hydrolytic enzymes and expose an egg-binding protein. Because NAADP (nicotinic acid adenine dinucleotide phosphate) releases Ca2+ from acidic lysosome-related organelles in other cell types, we investigated a possible role for NAADP in mediating the acrosome reaction. We report that NAADP binds with high affinity to permeabilized sea urchin sperm. Moreover, we used Mn2+ quenching of luminal fura-2 and 45Ca2+ to directly demonstrate NAADP regulation of a cation channel on the acrosome. Additionally, we show that NAADP synthesis occurs through base exchange and is driven by an increase in Ca2+. We propose a new model for acrosome reaction signaling in which Ca2+ influx initiated by egg jelly stimulates NAADP synthesis and that this NAADP acts on its receptor/channel on the acrosome to release Ca2+ to drive acrosomal exocytosis. PMID:20400502

Vasudevan, Sridhar R.; Lewis, Alexander M.; Chan, Jennifer W.; Machin, Claire L.; Sinha, Debroshi; Galione, Antony; Churchill, Grant C.

2010-01-01

387

A controlled release of antibiotics from calcium phosphate-coated poly(lactic-co-glycolic acid) particles and their in vitro efficacy against Staphylococcus aureus biofilm.  

PubMed

Ceramic-polymer hybrid particles, intended for osteomyelitis treatment, were fabricated by preparing poly(lactic-co-glycolic acid) particles through an emulsion solvent evaporation technique, followed by calcium phosphate (CaP) coating via a surface adsorption-nucleation method. The presence of CaP coating on the surface of the particles was confirmed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Subsequently, two antibiotics for treating bone infection, nafcillin (hydrophilic) and levofloxacin (amphiphilic), were loaded into these hybrid particles and their in vitro drug release studies were investigated. The CaP coating was shown to reduce burst release, while providing sustained release of the antibiotics for up to 4 weeks. In vitro bacterial study against Staphylococcus aureus demonstrated the capability of these antibiotic-loaded hybrid particles to inhibit biofilm formation as well as deteriorate established biofilm, making this hybrid system a potential candidate for further investigation for osteomyelitis treatment. PMID:24370968

Bastari, Kelsen; Arshath, Mohamed; Ng, Zhi Hui Melissa; Chia, Jia Hua; Yow, Zhi Xian Daniel; Sana, Barindra; Tan, Meng Fong Cherine; Lim, Sierin; Loo, Say Chye Joachim

2014-03-01

388

L/N-type calcium channel blocker cilnidipine reduces plasma aldosterone, albuminuria, and urinary liver-type fatty acid binding protein in patients with chronic kidney disease.  

PubMed

Cilnidipine inhibits both L- and N-type calcium channels and has been shown to dilate efferent arterioles as effectively as afferent arterioles. We conducted an open-label, randomized trial to compare the effects of cilnidipine against those of amlodipine on blood pressure (BP), albuminuria, and plasma aldosterone concentration in hypertensive patients with mild- to moderate-stage chronic kidney disease. Patients with BP ?130/80 mmHg, an estimated glomerular filtration rate of 90-30 ml/min/1.73 m(2), and albuminuria ?30 mg/g, despite treatment with the maximum recommended dose of angiotensin II receptor blockers, were randomly assigned to two groups. Patients received either 10 mg/day cilnidipine (increased to 20 mg/day; n = 35) or 2.5 mg/day amlodipine (increased to 5 mg/day; n = 35). After 48 weeks of treatment, a significant and comparable reduction in systolic and diastolic BP was observed in both groups. The percent reduction in the urinary albumin to creatinine ratio and liver-type fatty acid binding protein (L-FABP) in the cilnidipine group was significantly greater than in the amlodipine group. Although plasma renin activity did not differ between the two groups, the plasma aldosterone level was significantly decreased in the cilnidipine group. Cilnidipine therefore appears to reduce albuminuria, urinary L-FABP, and plasma aldosterone levels more than amlodipine, and these effects are independent of BP reduction. PMID:22914905

Abe, Masanori; Maruyama, Noriaki; Suzuki, Hiroko; Inoshita, Atsushi; Yoshida, Yoshinori; Okada, Kazuyoshi; Soma, Masayoshi

2013-07-01

389

Comparison of enriched palmitic acid and calcium salts of palm fatty acids distillate fat supplements on milk production and metabolic profiles of high-producing dairy cows.  

PubMed

A variable response to fat supplementation has been reported in dairy cows, which may be due to cow production level, environmental conditions, or diet characteristics. In the present experiment, the effect of a high palmitic acid supplement was investigated relative to a conventional Ca salts of palm fatty acids (Ca-FA) supplement in 16 high-producing Holstein cows (46.6±12.4kg of milk/d) arranged in a crossover design with 14-d periods. The experiment was conducted in a non-heat-stress season with 29.5% neutral detergent fiber diets. Treatments were (1) high palmitic acid (PA) supplement fed as free FA [1.9% of dry matter (DM); 84.8% C16:0] and (2) Ca-FA supplement (2.3% of DM; 47.7% C16:0, 35.9% C18:1, and 8.4% C18:2). The PA supplement tended to increase DM intake, and increased the yields of milk and energy-corrected milk. Additionally, PA increased the yields of milk fat, protein, and lactose, whereas milk concentrations of these components were not affected. The yields of milk de novo and 16-C FA were increased by PA compared with Ca-FA (7 and 20%, respectively), whereas the yield of preformed FA was higher in Ca-FA. A reduction in milk fat concentration of de novo and 16-C FA and a marginal elevation in trans-10 C18:1 in Ca-FA is indicative of altered ruminal biohydrogenation and increased risk of milk fat depression. No effect of treatment on plasma insulin was observed. A treatment by time interaction was detected for plasma nonesterified fatty acids (NEFA), which tended to be higher in Ca-FA than in PA before feeding. Overall, the palmitic acid supplement improved production performance in high-producing cows while posing a lower risk for milk fat depression compared with a supplement higher in unsaturated FA. PMID:25022691

Rico, D E; Ying, Y; Harvatine, K J

2014-09-01

390

Preventive effect of a pectic polysaccharide of the common cranberry Vaccinium oxycoccos L. on acetic acid-induced colitis in mice  

Microsoft Academic Search

AIM: To study isolation and chemical characterization of pectin derived from the common cranberry Vaccinium oxycoccos L. (oxycoccusan OP) and the testing of its preventive effect on experimental colitis. METHODS: Mice were administrated orally with OP two days prior to a rectal injection of 5% acetic acid and examined for colonic damage 24 h later. Colonic inflammation was characterized by

Sergey V Popov; Pavel A Markov; Ida R Nikitina; Sergey Petrishev; Vasily Smirnov; Yury S Ovodov

391

Preventive Effects of Omega3 and Omega6 Fatty Acids on Peroxide Mediated Oxidative Stress Responses in Primary Human Trabecular Meshwork Cells  

Microsoft Academic Search

Pathologic processes in glaucoma include increased apoptosis, accumulation of extracellular material in the trabecular meshwork and optic nerve, condensations of the cytoskeleton and precocious cellular senescence. Oxidative stress was shown to generate these alterations in primary ocular cells. Fatty acids omega-3 and -6 are alleged to constitute a prophylaxis against these deleterious effects. Here, we tested actual preventive effects omega-3

Theofilos Tourtas; Marco T. Birke; Friedrich E. Kruse; Ulrich-Christoph Welge-Lüssen; Kerstin Birke

2012-01-01

392

Calcium release from the endoplasmic reticulum of higher plants elicited by the NADP metabolite nicotinic acid adenine dinucleotide phosphate.  

PubMed

Higher plants share with animals a responsiveness to the Ca(2+) mobilizing agents inositol 1,4,5-trisphosphate (InsP(3)) and cyclic ADP-ribose (cADPR). In this study, by using a vesicular (45)Ca(2+) flux assay, we demonstrate that microsomal vesicles from red beet and cauliflower also respond to nicotinic acid adenine dinucleotide phosphate (NAADP), a Ca(2+)-releasing molecule recently described in marine invertebrates. NAADP potently mobilizes Ca(2+) with a K(1/2) = 96 nM from microsomes of nonvacuolar origin in red beet. Analysis of sucrose gradient-separated cauliflower microsomes revealed that the NAADP-sensitive Ca(2+) pool was derived from the endoplasmic reticulum. This exclusively nonvacuolar location of the NAADP-sensitive Ca(2+) pathway distinguishes it from the InsP(3)- and cADPR-gated pathways. Desensitization experiments revealed that homogenates derived from cauliflower tissue contained low levels of NAADP (125 pmol/mg) and were competent in NAADP synthesis when provided with the substrates NADP and nicotinic acid. NAADP-induced Ca(2+) release is insensitive to heparin and 8-NH(2)-cADPR, specific inhibitors of the InsP(3)- and cADPR-controlled mechanisms, respectively. However, NAADP-induced Ca(2+) release could be blocked by pretreatment with a subthreshold dose of NAADP, as previously observed in sea urchin eggs. Furthermore, the NAADP-gated Ca(2+) release pathway is independent of cytosolic free Ca(2+) and therefore incapable of operating Ca(2+)-induced Ca(2+) release. In contrast to the sea urchin system, the NAADP-gated Ca(2+) release pathway in plants is not blocked by L-type channel antagonists. The existence of multiple Ca(2+) mobilization pathways and Ca(2+) release sites might contribute to the generation of stimulus-specific Ca(2+) signals in plant cells. PMID:10890899

Navazio, L; Bewell, M A; Siddiqua, A; Dickinson, G D; Galione, A; Sanders, D

2000-07-18

393

Calcium pyrophosphate arthritis (Pseudogout)  

MedlinePLUS

Calcium pyrophosphate dihydrate deposition disease; CPPD disease; Acute CPPD arthritis; Pseudogout ... Calcium pyrophosphate arthritis is caused by the collection of salt called calcium pyrophosphate dihydrate (CPPD). The buildup ...

394

Conjugated linoleic Acid prevents ovariectomy-induced bone loss in mice by modulating both osteoclastogenesis and osteoblastogenesis.  

PubMed

Postmenopausal osteoporosis due to estrogen deficiency is associated with severe morbidity and mortality. Beneficial effects of conjugated linoleic acid (CLA) on bone mineral density (BMD) have been reported in mice, rats and humans, but the effect of long term CLA supplementation against ovariectomy-induced bone loss in mice and the mechanisms underlying this effect have not been studied yet. Eight-week old ovariectomized (Ovx) and sham operated C57BL/6 mice were fed either a diet containing 0.5 % safflower oil (SFO) or 0.5 % CLA for 24 weeks to examine BMD, bone turn over markers and osteotropic factors. Bone marrow (BM) cells were cultured to determine the effect on inflammation, osteoclastogenesis, and osteoblastogenesis. SFO/Ovx mice had significantly lower femoral, tibial and lumbar BMD compared to SFO/Sham mice; whereas, no difference was found between CLA/Ovx and CLA/Sham mice. CLA inhibited bone resorption markers whereas enhanced bone formation markers in Ovx mice as compared to SFO-fed mice. Reverse transcriptase polymerase chain reaction and fluorescence activated cell sorting analyses of splenocytes revealed that CLA inhibited pro-osteoclastogenic receptor activator of NF-?B (RANKL) and stimulated decoy receptor of RANKL, osteoprotegerin expression. CLA also inhibited pro-inflammatory cytokine and enhanced anti-inflammatory cytokine production of lipopolysaccharide-stimulated splenocytes and BM cells. Furthermore, CLA inhibited osteoclast differentiation in BM and stimulated osteoblast differentiation in BM stromal cells as confirmed by tartrate resistant acid phosphatase and Alizarin Red staining, respectively. In conclusion, CLA may prevent postmenopausal bone loss not only by inhibiting excessive bone resorption due to estrogen deficiency but also by stimulating new bone formation. CLA might be a potential alternative therapy against osteoporotic bone loss. PMID:24338525

Rahman, Md Mizanur; Fernandes, Gabriel; Williams, Paul

2014-03-01

395

Rapid Low Temperature-Induced Stomatal Closure Occurs in Cold-Tolerant Commelina communis Leaves But Not in Cold-Sensitive Tobacco Leaves, via a Mechanism That Involves Apoplastic Calcium But Not Abscisic Acid1  

PubMed Central

Commelina communis stomata closed within 1 h of transferring intact plants from 27°C to 7°C, whereas tobacco (Nicotiana rustica) stomata did not until the leaves wilted. Abscisic acid (ABA) did not mediate cold-induced C. communis stomatal closure: At low temperatures, bulk leaf ABA did not increase; ABA did not preferentially accumulate in the epidermis; its flux into detached leaves was lower; its release from isolated epidermis was not greater; and stomata in epidermal strips were less sensitive to exogenous ABA. Stomata of both species in epidermal strips on large volumes of cold KCl failed to close unless calcium was supplied. Therefore, the following cannot be triggers for cold-induced stomatal closure in C. communis: direct effects of temperature on guard or epidermal cells, long-distance signals, and effects of temperature on photosynthesis. Low temperature increased stomatal sensitivity to external CaCl2 by 50% in C. communis but only by 20% in tobacco. C. communis stomata were 300- to 1,000-fold more sensitive to calcium at low temperature than tobacco stomata, but tobacco epidermis only released 13.6-fold more calcium into bathing solutions than C. communis. Stomata in C. communis epidermis incubated on ever-decreasing volumes of cold calcium-free KCl closed on the lowest volume (0.2 cm3) because the epidermal apoplast contained enough calcium to mediate closure if this was not over diluted. We propose that the basis of cold-induced stomatal closure exhibited by intact C. communis leaves is increased apoplastic calcium uptake by guard cells. Such responses do not occur in chill-sensitive tobacco leaves. PMID:11500555

Wilkinson, Sally; Clephan, Alison Lee; Davies, William John

2001-01-01