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1

Glycochenodeoxycholic acid inhibits calcium phosphate precipitation in vitro by preventing the transformation of amorphous calcium phosphate to calcium hydroxyapatite.  

PubMed Central

Calcium hydroxyapatite can be a significant component of black pigment gallstones. Diverse molecules that bind calcium phosphate inhibit hydroxyapatite precipitation. Because glycine-conjugated bile acids, but not their taurine counterparts, bind calcium phosphate, we studied whether glycochenodeoxycholic acid inhibits calcium hydroxyapatite formation. Glycochenodeoxycholic acid (2 mM) totally inhibited transformation of amorphous calcium phosphate microprecipitates to macroscopic crystalline calcium hydroxyapatite. This inhibition was not mediated by decreased Ca2+ activity. Taurocholic acid (2-12 mM) did not affect hydroxyapatite formation, but antagonized glycochenodeoxycholic acid. Both amorphous and crystalline precipitates contained a surface fraction relatively rich in phosphate. The surface phosphate content was diminish by increasing glycochenodeoxycholic acid concentrations, and this relationship was interpreted as competition between bile acid and HPO4(-4) for binding sites on the calcium phosphate surface. A phosphate-rich crystal surface was associated with rapid transition from amorphous to crystalline states. These results indicate that glycochenodeoxycholic acid prevents transformation of amorphous calcium phosphate to crystalline hydroxyapatite by competitively inhibiting the accumulation of phosphate on the crystal embryo surface.

Qiu, S M; Wen, G; Hirakawa, N; Soloway, R D; Hong, N K; Crowther, R S

1991-01-01

2

Abscisic acid triggers whole-plant and fruit-specific mechanisms to increase fruit calcium uptake and prevent blossom end rot development in tomato fruit.  

PubMed

Calcium (Ca) uptake into fruit and leaves is dependent on xylemic water movement, and hence presumably driven by transpiration and growth. High leaf transpiration is thought to restrict Ca movement to low-transpiring tomato fruit, which may increase fruit susceptibility to the Ca-deficiency disorder, blossom end rot (BER). The objective of this study was to analyse the effect of reduced leaf transpiration in abscisic acid (ABA)-treated plants on fruit and leaf Ca uptake and BER development. Tomato cultivars Ace 55 (Vf) and AB2 were grown in a greenhouse environment under Ca-deficit conditions and plants were treated weekly after pollination with water (control) or 500 mg l(-1) ABA. BER incidence was completely prevented in the ABA-treated plants and reached values of 30-45% in the water-treated controls. ABA-treated plants had higher stem water potential, lower leaf stomatal conductance, and lower whole-plant water loss than water-treated plants. ABA treatment increased total tissue and apoplastic water-soluble Ca concentrations in the fruit, and decreased Ca concentrations in leaves. In ABA-treated plants, fruit had a higher number of Safranin-O-stained xylem vessels at early stages of growth and development. ABA treatment reduced the phloem/xylem ratio of fruit sap uptake. The results indicate that ABA prevents BER development by increasing fruit Ca uptake, possibly by a combination of whole-plant and fruit-specific mechanisms. PMID:21282326

de Freitas, Sergio Tonetto; Shackel, Kenneth A; Mitcham, Elizabeth J

2011-05-01

3

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.

4

The Role of Calcium in Prevention and Treatment of Osteoporosis.  

ERIC Educational Resources Information Center

Osteoporosis results from several factors. Calcium deficiency is only one, and high calcium intake will prevent only those cases in which calcium is the limiting factor. Calcium cannot reverse, but only arrest, bone loss. A high calcium intake for every member of the population is advocated. (Author/MT)

Heaney, Robert P.

1987-01-01

5

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

PubMed Central

E3-6.7K is a small and hydrophobic membrane glycoprotein encoded by the E3 region of subgroup C adenovirus. Recently, E3-6.7K has been shown to be required for the downregulation of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptors by the adenovirus E3/10.4K and E3/14.5K complex of proteins. We demonstrate here that E3-6.7K has additional protective roles, independent of other virus proteins. In transfected Jurkat T-cell lymphoma cells, E3-6.7K was found 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. In addition, E3-6.7K protected cells against apoptosis induced through Fas, TNF receptor, and TRAIL receptors. Therefore, E3-6.7K confers a wide range of protective effects against both Ca2+ flux-induced and death receptor-mediated apoptosis.

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

2002-01-01

6

Calcium Prevents Tumorigenesis in a Mouse Model of Colorectal Cancer  

PubMed Central

Background and Aim Calcium has been proposed as a mediator of the chemoprevention of colorectal cancer (CRC), but the comprehensive mechanism underlying this preventive effect is not yet clear. Hence, we conducted this study to evaluate the possible roles and mechanisms of calcium-mediated prevention of CRC induced by 1,2-dimethylhydrazine (DMH) in mice. Methods For gene expression analysis, 6 non-tumor colorectal tissues of mice from the DMH + Calcium group and 3 samples each from the DMH and control groups were hybridized on a 4×44 K Agilent whole genome oligo microarray, and selected genes were validated by real-time polymerase chain reaction (PCR). Functional analysis of the microarray data was performed using KEGG and Gene Ontology (GO) analyses. Hub genes were identified using Pathway Studio software. Results The tumor incidence rates in the DMH and DMH + Calcium groups were 90% and 40%, respectively. Microarray gene expression analysis showed that S100a9, Defa20, Mmp10, Mmp7, Ptgs2, and Ang2 were among the most downregulated genes, whereas Per3, Tef, Rnf152, and Prdx6 were significantly upregulated in the DMH + Calcium group compared with the DMH group. Functional analysis showed that the Wnt, cell cycle, and arachidonic acid pathways were significantly downregulated in the DMH + Calcium group, and that the GO terms related to cell differentiation, cell cycle, proliferation, cell death, adhesion, and cell migration were significantly affected. Forkhead box M1 (FoxM1) and nuclear factor kappa-B (NF-?B) were considered as potent hub genes. Conclusion In the DMH-induced CRC mouse model, comprehensive mechanisms were involved with complex gene expression alterations encompassing many altered pathways and GO terms. However, how calcium regulates these events remains to be studied.

Chen, Hui-Min; Kong, Xuan; Xiong, Hua; Shen, Nan; Hong, Jie; Fang, Jing-Yuan

2011-01-01

7

Calcium apatite prepared from calcium hydroxide and orthophosphoric acid  

Microsoft Academic Search

Calcium hydroxyapatite has been prepared due to a direct precipitation reaction between 0.3m orthophosphoric acid solution and 0.1 mol calcium hydroxide dispersed in 200 ml water. The effect of the addition rate of the acid solution, reaction temperature and mixing molar Ca\\/P ratio is examined on the thermal stability and stoichiometry of the precipitates. Optimum conditions for HAp suitable for

A. Osaka; Y. Miura; K. Takeuchi; M. Asada; K. Takahashi

1991-01-01

8

Humic acid complexation of calcium and copper  

SciTech Connect

High-affinity metal binding by isolated humic acids has been observed for both copper and calcium in metal titration experiments. Results of titration of humic acids with a single metal (either calcium or copper) are consistent with a discrete ligand site model of humate-metal binding. However, copper titrations in the presence of excess calcium do not show competitive effects predicted by such a model. Hence, different ligand sites must be involved in calcium and copper binding, or a binding mechanism other than discrete ligand binding must be operative.

Hering, J.G.; Morel, F.M.M.

1984-10-01

9

Development and Field Application of a Novel Non-acid Calcium Naphthenate Inhibitor  

Microsoft Academic Search

Current state of the art for treating calcium naphthenates requires addition of large doses of acid to the production fluids. Although effective in dissolving deposits, acid treatments result in increased corrosion in production equipment, decreased oil quality and increased transport and HSE costs. Consequently, an opportunity exists for the development of non-acid inhibitors to prevent calcium naphthenate formation without the

Justin Debord; Piyush Srivastava

2009-01-01

10

The solubilization of calcium soaps by fatty acids  

Microsoft Academic Search

The solubilization of the calcium soaps of long chain fatty acids by liquid fatty acids was observed. The solubilities of\\u000a calcium palmitate, calcium laurate, and calcium oleate were 15.6, 22.8, and 53.3 wt%, respectively, in oleic acid at 40°C.\\u000a The formation of an acid-calcium soap complex was demonstrated by x-ray diffraction studies of calcium laurate, lauric acid,\\u000a and a mixture

R. J. Jandacek

1991-01-01

11

Use of High Calcium Infant Formula to Prevent Plumbism.  

National Technical Information Service (NTIS)

This study explored an alternative form of primary prevention of lead poisoning in children using the nutritional supplement calcium glycerophosphate added to infant formula to reduce lead absorption from the gastrointestinal tract. Subjects were children...

J. D. Sargent

1992-01-01

12

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

13

Should We Prescribe Calcium Supplements For Osteoporosis Prevention?  

PubMed Central

Advocacy for the use of calcium supplements arose at a time when there were no other effective interventions for the prevention of osteoporosis. Their promotion was based on the belief that increasing calcium intake would increase bone formation. Our current understandings of the biology of bone suggest that this does not occur, though calcium does act as a weak antiresorptive. Thus, it slows postmenopausal bone loss but, despite this, recent meta-analyses suggest no significant prevention of fractures. In sum, there is little substantive evidence of benefit to bone health from the use of calcium supplements. Against this needs to be balanced the likelihood that calcium supplement use increases cardiovascular events, kidney stones, gastrointestinal symptoms, and admissions to hospital with acute gastrointestinal problems. Thus, the balance of risk and benefit seems to be consistently negative. As a result, current recommendations are to obtain calcium from the diet in preference to supplements. Dietary calcium intake has not been associated with the adverse effects associated with supplements, probably because calcium is provided in smaller boluses, which are absorbed more slowly since they come together with quantities of protein and fat, resulting in a slower gastric transit time. These findings suggest that calcium supplements have little role to play in the modern therapeutics of osteoporosis, which is based around the targeting of safe and effective anti-resorptive drugs to individuals demonstrated to be at increased risk of future fractures.

2014-01-01

14

Acidic Calcium Stores of Saccharomyces cerevisiae  

PubMed Central

Fungi and animals constitute sister kingdoms in the eukaryotic domain of life. The major classes of transporters, channels, sensors, and effectors that move and respond to calcium ions were already highly networked in the common ancestor of fungi and animals. Since that time, some key components of the network have been moved, altered, relocalized, lost, or duplicated in the fungal and animal lineages and at the same time some of the regulatory circuitry has been dramatically rewired. Today the calcium transport and signaling networks in fungi provide a fresh perspective on the scene that has emerged from studies of the network in animal cells. This review provides an overview of calcium signaling networks in fungi, particularly the model yeast Saccharomyces cerevisiae, with special attention to the dominant roles of acidic calcium stores in fungal cell physiology.

Cunningham, Kyle W.

2011-01-01

15

Calcium-based Lewis acid catalysts.  

PubMed

Recently, Lewis acidic calcium salts bearing weakly coordinating anions such as Ca(NTf?)?, Ca(OTf)?, CaF? and Ca[OCH(CF?)?]? have been discovered as catalysts for the transformation of alcohols, olefins and carbonyl compounds. High stability towards air and moisture, selectivity and high reactivity under mild reaction conditions render these catalysts a sustainable and mild alternative to transition metals, rare-earth metals or strong Brønsted acids. PMID:23712417

Begouin, Jeanne-Marie; Niggemann, Meike

2013-06-17

16

Biliary calcium and bile acid secretion in intact and TPTX rats with varying plasma calcium concentration  

Microsoft Academic Search

Investigations of the effects of plasma calcium concentration on the relationship between biliary secretion of bile acid and calcium were performed in normocalcemic, calcium gluconate-induced hypercalcemie, thyroparathyroidectomy-induced hypocalcemic (TPTX) rats, and TPTX rats that received calcium gluconate to maintain normocalcemia. Studies were done at normal bile flow and at sodium taurocholate-stimulated bile flow. The results showed that biliary calcium secretion,

L. Limlomwongse; C. Deachapunya; N. Krishnamra

1988-01-01

17

Osteoporosis prevention in female adolescents: calcium intake and exercise participation.  

PubMed

Adolescence is a critical period for physiologic growth. Calcium consumption and exercise affect bone mass, and both may be the most significant factors in preventing osteoporosis. The purpose of this study was to identify problem areas that would place adolescent females at risk for developing osteoporosis. The sample consisted of 293 adolescent females, ages 14 to 19 years. Data collected included assessment of calcium consumption, physical activities, and variables that may affect both. Results showed that participants consumed inadequate calcium but were attentive to participate in physical activities. Half of the sample reported skipping one meal per day, slightly over half were trying to lose weight, and almost three fourths were trying to keep from gaining weight. Predictors of calcium intake were skipping meals, perception of barriers to calcium intake, and trying to lose weight (beta weight: 0.29, 0.28, and 0.25, respectively). Predictors of exercise were perceptions of barriers and benefits to exercise (beta weights: 0.27 and 0.13, respectively). Nutritional education and behavior modification strategies to address the findings are presented. PMID:12962249

Ali, N; Siktberg, L

2001-01-01

18

Calcium antagonists in the prevention of motion sickness.  

PubMed

Flunarizine is a calcium antagonist which has proved clinically useful in controlling chronic vertigo. In a double blind crossover trial 10 subjects were used to compare the electronystagmic responses to motion in patients taking flunarizine, prochlorperazine maleate, or placebo. Flunarizine is shown to be a powerful peripherally acting labyrinthine suppressant, with application in the prevention of motion sickness. Flunarizine produces none of the central depressive side effects characteristic of antihistamines and anticholinergics, which are the conventional anti-motion sickness drugs. PMID:3510617

Lee, J A; Watson, L A; Boothby, G

1986-01-01

19

Folic Acid Helps Prevent Neural Tube Defects  

MedlinePLUS

... Submit What's this? Submit Button CDC Features Folic Acid Helps Prevent Neural Tube Defects Language: English Español ( ... day before and during pregnancy. What Is Folic Acid? Folic acid is a B vitamin. Our bodies ...

20

Plasma phospholipid arachidonic acid content and calcium metabolism in idiopathic calcium nephrolithiasis  

Microsoft Academic Search

Plasma phospholipid arachidonic acid content and calcium metabolism in idiopathic calcium nephrolithiasis.BackgroundReports of an increase in plasma and erythrocyte phospholipid arachidonic acid content and in urinary prostaglandin E2 (PGE2) excretion in patients with idiopathic calcium nephrolithiasis suggested their crucial role in the pathogenesis of hypercalciuria, a well-known risk factor for lithogenesis.MethodsTo confirm this hypothesis, 15 healthy subjects and 20 nephrolithiasis

Bruno Baggio; Alessandro Budakovic; Maria Angela Nassuato; Giuseppe Vezzoli; Enzo Manzato; Giovanni Luisetto; Martina Zaninotto

2000-01-01

21

Oxalic acid decreases calcium absorption in rats  

SciTech Connect

Calcium absorption from salts and foods intrinsically labeled with /sup 45/Ca was determined in the rat model. Calcium bioavailability was nearly 10 times greater for low oxalate kale, CaCO/sub 3/ and CaCl/sub 2/ than from CaC/sub 2/O/sub 4/ (calcium oxalate) and spinach (high in oxalates). Extrinsic and intrinsic labeling techniques gave a similar assessment of calcium bioavailability from kale but not from spinach.

Weaver, C.M.; Martin, B.R.; Ebner, J.S.; Krueger, C.A.

1987-11-01

22

Preventing ?-Cell Loss and Diabetes With Calcium Channel Blockers  

PubMed Central

Although loss of functional ?-cell mass is a hallmark of diabetes, no treatment approaches that halt this process are currently available. We recently identified thioredoxin-interacting protein (TXNIP) as an attractive target in this regard. Glucose and diabetes upregulate ?-cell TXNIP expression, and TXNIP overexpression induces ?-cell apoptosis. In contrast, genetic ablation of TXNIP promotes endogenous ?-cell survival and prevents streptozotocin (STZ)- and obesity-induced diabetes. Finding an oral medication that could inhibit ?-cell TXNIP expression would therefore represent a major breakthrough. We were surprised to discover that calcium channel blockers inhibited TXNIP expression in INS-1 cells and human islets and that orally administered verapamil reduced TXNIP expression and ?-cell apoptosis, enhanced endogenous insulin levels, and rescued mice from STZ-induced diabetes. Verapamil also promoted ?-cell survival and improved glucose homeostasis and insulin sensitivity in BTBR ob/ob mice. Our data further suggest that this verapamil-mediated TXNIP repression is conferred by reduction of intracellular calcium, inhibition of calcineurin signaling, and nuclear exclusion and decreased binding of carbohydrate response element–binding protein to the E-box repeat in the TXNIP promoter. Thus, for the first time, we have identified an oral medication that can inhibit proapoptotic ?-cell TXNIP expression, enhance ?-cell survival and function, and prevent and even improve overt diabetes.

Xu, Guanlan; Chen, Junqin; Jing, Gu; Shalev, Anath

2012-01-01

23

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

24

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

25

Prevention of CCl4-induced liver necrosis by the calcium chelator arsenazo III.  

PubMed

Arsenazo III (AIII) (100 mg/kg ip in saline) administration to Sprague-Dawley male rats 30 min before or 6 or 10 hr after CCl4 [1 ml/kg ip as a 20% (v/v) solution in olive oil] significantly prevented liver necrosis but not fatty liver caused by the hepatotoxin at 24 hr as demonstrated either by histology or by determination of isocitric acid dehydrogenase in plasma. AIII did not modify the CCl4 concentrations reaching the liver, the intensity of the covalent binding of CCl4-reactive metabolites to hepatic microsomal lipids, or the CCl4-promoted lipid peroxidation process at either 1 or 3 hr of poisoning. AIII administration enhanced glutathione (GSH) levels in liver and significantly prevented the CCl4-induced minor decreases in GSH content and the CCl4-induced increases in calcium content at 24 hr of intoxication. AIII treatment further enhanced the CCl4-induced decreases in body temperature of the poisoned rats. Results suggest that AIII's preventive effects might be related to its very well-known calcium-chelating properties, but that additional factors related to AIII's ability to increase GSH content in liver or to decrease body temperature of CCl4-intoxicated animals may also play a role. PMID:8519346

de Ferreyra, E C; Bernacchi, A S; Villarruel, M C; de Fenos, O M; Castro, J A

1993-06-01

26

Vitamin D and Calcium Supplementation to Prevent Fractures  

MedlinePLUS

... important nutrients that work together to keep bones strong. Both nutrients are found naturally in foods but ... properly. Calcium is a mineral that helps maintain strong bones and teeth. The body also needs calcium ...

27

Ascorbic acid, calcium, phosphorus and magnesium intake variations: effects on calcium, phosphorus and magnesium utilization by human adults  

SciTech Connect

The objective of the study was to determine the effects of feeding two levels of ascorbic acid, calcium, phosphorus, magnesium and ascorbic acid on the apparent utilization of calcium, phosphorus and magnesium by healthy, human adult subjects. During 4 randomly-arranged experimental periods of 7 days each, a laboratory-controlled diet alone or with supplements of ascorbic acid, dicalcium phosphate or magnesium oxide was fed to the 18 subjects. Results indicated that ascorbic acid supplementation tended to reduce urinary phosphorus loss and to slightly increase fecal phosphorus loss so that overall phosphorus balances became more positive. Conversely, under these conditions, urinary calcium losses were little affected but fecal calcium losses were increased resulting in an overall decrease in calcium balance with ascorbic acid supplementation. Ascorbic acid supplementation resulted in decreased urine and fecal losses of magnesium and more positive magnesium balances. Magnesium supplementation resulted in more positive calcium and phosphorus balances as did calcium phosphate supplementation on magnesium balance.

Kies, C.; Brennan, M.A.; Parks, S.K.; Stauffer, D.J.; Wang, H.Y.; Young, S.F.; Fox, H.M.

1986-03-01

28

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

29

Partial depletion of sarcoplasmic reticulum calcium does not prevent calcium sparks in rat ventricular myocytes.  

PubMed Central

1. The exact nature of calcium sparks in the heart remains highly controversial. We sought to determine whether calcium sparks arise from a single or multiple calcium release channels/ ryanodine receptors in the sarcoplasmic reticulum (SR). If their genesis involves a calcium-coupled recruitment of multiple channels, calcium sparks might be abolished by a modest depletion of SR calcium (because of the decrease in unitary calcium flux and hence a decrease in the gain of local calcium-induced calcium release). If, on the other extreme, calcium sparks are produced despite severe SR depletion, the single-channel origin will be preferred. 2. Spontaneous calcium sparks were studied in rat ventricular myocytes using confocal microscopy and the fluorescent calcium probe fluo-3. A computer algorithm was developed to count and measure objectively calcium sparks in linescan images. 3. Thapsigargin (25-150 nM) depleted caffeine-releasable SR calcium by up to 64%, in a dose- and time-dependent manner, without altering the resting cytosolic calcium level. During SR depletion, calcium sparks were robustly observed, albeit at reduced frequency (> or = 30% of control) and amplitude (> or = 60% of control). 4. Due to the reduced detectability of small sparks against noise background, the observed data would overestimate reduction in spark frequency but underestimate amplitude reduction. After correction for this detection bias, we found that the spark frequency was independent of SR load, whereas the amplitude was proportional to load. 5. We conclude that, although spark amplitude depends on SR filling status, the frequency of spark generation is independent of SR calcium load, and therefore independent of the local calcium release rate. This implies that sparks are single-channel events, or collective events that are well above threshold for local regeneration. Additionally, our results suggest that intraluminal SR calcium, at normal or low loads, does not play a major role in the regulation of on-gating of the ryanodine receptor. Images Figure 1

Song, L S; Stern, M D; Lakatta, E G; Cheng, H

1997-01-01

30

Comparative absorption of calcium sources and calcium citrate malate for the prevention of osteoporosis.  

PubMed

Anthropologically speaking, humans were high consumers of calcium until the onset of the Agricultural Age, 10,000 years ago. Current calcium intake is one-quarter to one-third that of our evolutionary diet and, if we are genetically identical to the Late Paleolithic Homo sapiens, we may be consuming a calcium-deficient diet our bodies cannot adjust to by physiologic mechanisms. Meta-analyses of calcium and bone mass studies demonstrate supplementation of 500 to 1500 mg calcium daily improves bone mass in adolescents, young adults, older men, and postmenopausal women. Calcium citrate malate has high bioavailability and thus has been the subject of calcium studies in these populations. Positive effects have been seen in prepubertal girls, adolescents, and postmenopausal women. The addition of trace minerals and vitamin D in separate trials has improved the effect of calcium citrate malate on bone density and shown a reduction of fracture risk. PMID:10231607

Patrick, L

1999-04-01

31

Comparative Absorption of Calcium Sources and Calcium Citrate Malate for the Prevention of Osteoporosis  

Microsoft Academic Search

Anthropologically speaking, humans were high consumers of calcium until the onset of the Agricultural Age, 10,000 years ago. Current calcium intake is one-quarter to one-third that of our evolutionary diet and, if we are genetically identical to the Late Paleolithic Homo sapiens, we may be consuming a calcium-deficient diet our bodies cannot adjust to by physiologic mechanisms. Meta-analyses of calcium

Lyn Patrick

1999-01-01

32

Calcium sulphate scale prevention in a desalinatïon unit using the SMCEC technique  

Microsoft Academic Search

The desalination unit UTAIM using the solar multiple condensation evaporation cycle principle (SMCEC) is confronted with the problem of heat-exchange surface plugging by dihydrate calcium sulphate. The aim of this work is the prevention of this scale problem by using chemical inhibitors. The kinetics of calcium sulphate nucleation and crystalline growth increase with temperature. At all operating temperatures, the solution

S. Ben Ahmed; M. Tlili; M. Ben Amor; H. Ben Bacha; B. Elleuch

2004-01-01

33

Solubility of calcium soaps of long-chain fatty acids in simulated intestinal environment  

Microsoft Academic Search

Calcium soaps of long-chain fatty acids are often referred to as being insoluble. These soaps make up most of the fecal lipid in infants fed high calcium diets and are responsible for increased fat malabsorption in patients with exocrine pancreatic insufficiency receiving enzymes and calcium carbonate antacids. We investigated the solubility of the calcium soaps of long-chain fatty acids in

David Y. Graham; Jeffrey W. Sackman

1983-01-01

34

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

PubMed

Cytosolic free calcium concentration ([Ca(2+)]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(2+)]i overload, which results in barrier failure. In a model of cultured porcine aortic endothelial monolayers (EC), we addressed the question of whether [Ca(2+)]i overload can be prevented by lithium treatment. [Ca(2+)]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 (5mM; 2-DG) plus sodium cyanide (5mM; 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(2+)]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 10mM 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(2+)]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(2+)]i. A 24-h pre-treatment with 10mM of lithium chloride before the inhibition of ATP synthesis abolished both phases of the 2-DG-induced [Ca(2+)]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(2+)]i overload in EC and that this most likely occurs by preventing inositol 3-phosphate-sensitive Ca(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. PMID:23541580

Bosche, Bert; Schäfer, Matthias; Graf, Rudolf; Härtel, Frauke V; Schäfer, Ute; Noll, Thomas

2013-05-01

35

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

36

Morphological control of calcium oxalate particles in the presence of poly-(styrene-alt-maleic acid)  

NASA Astrophysics Data System (ADS)

Calcium oxalate (CaOx) particles exhibiting different shapes and phase structures were fabricated by a simple precipitation reaction of sodium oxalate with calcium chloride in the absence and presence of poly-(styrene-alt-maleic acid) (PSMA) as a crystal modifier at room temperature. The as-obtained products were characterized with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of reaction conditions including pH, [Ca 2+]/[C 2O 42-] ratio and concentration of PSMA and CaC 2O 4 on the crystal forms and morphologies of the as-obtained calcium oxalate were investigated. The results show that various crystal morphologies of calcium oxalate, such as parallelograms, plates, spheres, bipyramids etc. can be obtained depending on the experimental conditions. Higher polymer concentration favors formation of the metastable calcium oxalate dihydrate (COD) crystals. Lower pH is beneficial to the formation of plate-like CaOx crystals. Especially, the monodispersed parallelogram-like CaOx crystals can be produced by PSMA as an additive at pH 2. PSMA may act as a good inhibitor for urolithiasis since it induces the formation of COD and reduces the particle size of CaOx. This research may provide new insight into the morphological control of CaOx particles and the prevention of urolithiasis.

Yu, Jiaguo; Tang, Hua; Cheng, Bei; Zhao, Xiujian

2004-10-01

37

Reye-like syndrome following treatment with the pantothenic acid antagonist, calcium hopantenate.  

PubMed Central

Three senile patients developed fatal acute encephalopathy while receiving calcium hopantenate. The clinical, biochemical, and pathological picture was similar to Reye's syndrome. Calcium hopantenate is a pantothenic acid antagonist. The serum levels of calcium hopantenate were high in coma, and that of pantothenic acid examined in one patient was lowered. Evidence obtained indicated that the Reye-like syndrome might be caused by calcium hopantenate possibly due to the induction of pantothenic acid deficiency. Images

Noda, S; Umezaki, H; Yamamoto, K; Araki, T; Murakami, T; Ishii, N

1988-01-01

38

Calcium  

MedlinePLUS

... calcium. Veggies. You'll also find calcium in broccoli and dark green, leafy vegetables (especially collard and ... of calcium such as dark green, leafy vegetables, broccoli, chickpeas, and calcium-fortified products, including orange juice, ...

39

Stability of calcium carbonate and magnesium carbonate in rainwater and nitric acid solutions  

Microsoft Academic Search

Carbonation of magnesium and calcium silicates has emerged as an interesting option for long term storage of captured CO2. However, carbonated minerals are not stable in acidic environments. This study was conducted to determine if synthetically carbonated minerals dissolve in acidic rain and release CO2. Synthetic magnesium and calcium carbonates were leached in nitric acid solutions of various acidities, as

Sebastian Teir; Sanni Eloneva; Carl-Johan Fogelholm; Ron Zevenhoven

2006-01-01

40

Pelleting or Priming Seed with Calcium Improves Groundnut Seedling Survival in Acid Soils  

Microsoft Academic Search

A growth chamber experiment and a field experiment were conducted to investigate the effects of pelleting or priming groundnut seed with calcium (Ca), either as calcium sulfate (CaSO4), calcium chloride (CaCl2), calcium nitrate [Ca(NO3)2], calcium carbonate (CaCO3) or Calcimax on growth of groundnut seedlings in acid soils. In the growth chamber experiment, Ca-treated and non-treated groundnut seeds were planted in

M. R. Murata; G. E. Zharare; P. S. Hammes

2008-01-01

41

Phytic acid plus calcium, but not phytic acid alone, decreases fluoride bioavailability in the rat  

SciTech Connect

Results of in vitro studies have suggested that fluoride becomes insoluble when some soy-based infant formulas are diluted with fluoridated water because of the presence of phytate, added calcium or a combination of these factors. The present study was designed to test this hypothesis in vivo. Male albino rats were fed a purified diet containing phytic acid, calcium and fluoride for 4 weeks in a factorial design of treatments. Phytic acid was added to the diet by chemically reacting a phytic acid concentrate with casein prior to diet preparation to mimic a soy-protein. Food intake, weight gain and femur P were unaffected by dietary treatments. Both phytic acid and supplemental calcium alone had little or no effect upon fluoride uptake into either bone or teeth. The combination of phytic acid plus supplemental calcium, however, significantly increased % of fluoride intake found in the feces which was reflected in a significant decrease in fluoride concentration of femur, 2nd molar teeth and vertebrate bone. These results provide evidence that insoluble complex formation produced by a calcium and phytate interaction can explain reduced fluoride solubility in some soy-based infant formulas as well as decreased fluoride absorbability in vivo.

Cerklewski, F.L. (Oregon State Univ., Corvallis (United States))

1991-03-15

42

Lysophosphatidic acids. Influence on platelet aggregation and intracellular calcium flux.  

PubMed Central

Decanoyl-, palmitoyl-, and oleoyl-lysophosphatidic acid (LPA) were studied for their effects on platelet aggregation and intracellular calcium flux. Palmitoyl-LPA and oleoyl-LPA both caused a concentration-dependent aggregation of human blood platelets at concentrations of 12--300 microM. Aggregation by adenosine diphosphate (ADP) was enhanced at slightly lower concentrations. First-wave aggregation induced by these LPAs was not blocked by aspirin, indomethacin, or heparin, suggesting similarities to ADP aggregation. However, in washed platelets with a high calcium concentration, no serotonin secretion was observed, even though full aggregation occurred, suggesting that aggregation was not due to released ADP. This concept was supported by studies of platelets deficient in the storage pool of ADP and serotonin, which had a normal first-wave aggregation response to palmitoyl-LPA. Aggregation induced by palmitoyl LPA was inhibited by prostaglandin E1 (PGE1), theophylline, and ethylenediaminotetraacetate (EDTA), though in the presence of EDTA shape change occurred. Aggregation stimulated by palmitoyl-LPA or oleoyl-LPA was characterized by changes in the shape of the platelets with development of pseudopods and centralization of granules closely surrounded by contractile microfilaments and supporting microtubules. The addition of palmitoyl-LPA and oleoyl-LPA, but not decanoyl-LPA, caused the release of calcium from a platelet membrane fraction that contains elements of the intracellular calcium storage system and actively concentrates this cation in the presence of adenosine triphosphate (ATP) and magnesium. It is suggested that LPAs cause aggregation by stimulating the release of calcium intracellularly. Images Figure 1 Figure 2 Figure 3 Figure 4 Text-Figure 6

Gerrard, J. M.; Kindom, S. E.; Peterson, D. A.; Peller, J.; Krantz, K. E.; White, J. G.

1979-01-01

43

Targeting calcium and the mitochondria in prevention of pathology in the heart.  

PubMed

Calcium is a key determinant of cardiac excitation, contraction and relaxation. Cardiac excitation and contraction is powered by ATP that is synthesized within mitochondria via a calcium-dependent process known as oxidative phosphorylation. During this process oxygen molecules within the mitochondria are converted to superoxide. Under physiological conditions, low levels of ROS are required to maintain normal cellular function. This is achieved as a result of a balance between ROS formation and amelioration by antioxidants. Uninhibited increases in ROS production lead to oxidative stress. Large increases in ROS are associated with damage to mitochondria, DNA, proteins and lipids. In the heart this ultimately leads to apoptosis and loss of myocytes. However sub-lethal increases in ROS can activate hypertrophic signaling kinases and transcription factors including NFAT, CaMK and serine-threonine and tyrosine kinases. Calcium is also an important signaling molecule and a mediator of hypertrophic signaling pathways. ROS and calcium appear to participate as partners in pathological remodeling but their interaction and early mechanisms associated with the development of cardiac hypertrophy are poorly understood. An increase in cytoplasmic calcium can potentiate cellular oxidative stress via effects on mitochondrial metabolism. In addition oxidative stress can regulate the function of calcium channels and transporters. We discuss the evidence for calcium transporting proteins and the mitochondria in oxidative stress responses and propose sites to target in the prevention of cardiac hypertrophy. PMID:21291390

Viola, Helena M; Hool, Livia C

2011-05-01

44

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

Microsoft Academic Search

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose\\u000a (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate\\u000a (CSD, CaSO4·2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid\\u000a phase

Van Viet Thai; Byong-Taek Lee

2010-01-01

45

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

46

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

47

Comparison between perioperative treatment with calcium and with calcium and vitamin d in prevention of post thyroidectomy hypocalcemia.  

PubMed

Even though thyroid surgery is quite safe, mechanical damage, devascularization or inadvertent removal of the parathyroid glands are possible. Though postoperative mortality is extremely low, post thyroidectomy hypocalcemia is one of the most common and potentially life-threatening complication following thyroid surgery. The clinical manifestation varies from minimal twitching to life threatening tetany and can prolong the hospital stay. The purpose of this study is to evaluate the clinical usefulness of routine oral calcium with Vitamin D supplements in reducing the incidence and severity of hypocalcemia after total thyroidectomy. This safe and cost effective therapy may prevent the threatening complications like tetany and reduce the hospital stay. PMID:24533386

Nemade, Sanjana Vijay; Rokade, Vidya Vasant; Pathak, Netra Aniruddha; Tiwari, Shannu Sushil; Sonkhedkar, Sayali Jayant

2014-01-01

48

The study of modified calcium hydroxides with surfactants for acid gas removal during incineration.  

PubMed

The primary objective of the present work is to use additives to extend the sulfation reaction of the calcium hydroxide (Ca(OH)2) used to control SO2 emission from incineration processes. There are two reasons for adding surfactants (surface-active agent): (1) to provide an appropriate dispersion of the Ca(OH)2', thus preventing particle agglomeration due to humidity; (2) to alter the sulfation reaction environment by adsorbing heterogeneous materials on the surface of the Ca(OH)2 to extend the adsorption equilibrium. A dry scrubber integrated with a fabric filter was employed to study the effect of surfactants on the removal efficiency of acid gas in the flue gas with Ca(OH)2 as the sorbent. The operating parameters evaluated include: (1) the different surfactants (calcium lignosulfonate, sodium lignosulfonate, alkyl naphthalene sodium sulfonate and beta-naphthalene sodium sulfonate condensates) and (2) the composition of acid gas (i.e. sulfur dioxide (SO2), nitrogen oxide (NO) and hydrogen chloride (HCl)). The results show that modified Ca(OH)2 with surfactants could effectively decrease the emission of acid gas during incineration. Different additives had individual absorption efficiencies on different acid gases. On the whole, sodium lignosulfonate and beta-naphthalene sodium sulfonate condensates had better sorption capacity for SO2 and NO, but not for HCl. In addition, when SO2 coexisted with NO and HCl, the concentration of NO and HCl will result in decrease or increase of the removal efficiency of SO2. PMID:11924579

Tseng, H H; Wey, M Y; Lu, C Y

2002-01-01

49

Effect of calcium ion on fatty acid-induced generation of superoxide in guinea pig neutrophils.  

PubMed

When phospholipases of plasma membranes are activated by certain stimuli, unsaturated fatty acids are liberated. Because unsaturated fatty acids enhance the transmembrane movement of calcium ions, the fatty acids released may modulate intracellular calcium homeostasis in various cells, including neutrophils. To determine the physiological function of these unsaturated fatty acids, we studied the effects of various fatty acids on superoxide generation and on changes in intracellular calcium contents of guinea pig neutrophils. Some unsaturated fatty acids, arachidonate and linoleate, stimulated the rate of superoxide generation concomitant with the increase in the amount of intracellular calcium. In contrast, the saturated fatty acid, myristate, stimulated the generation of superoxide without affecting the content of intracellular calcium. The stimulating actions of arachidonate and myristate were increased dramatically by the presence of a low concentration (1 microM) of extracellular calcium ion. The rate of superoxide generation in fatty acid-treated neutrophils was inhibited by chlorpromazine, an inhibitor of such calcium-binding proteins as C-kinase. These and other observations suggest that liberated unsaturated fatty acids increase the amount of intracellular calcium and enhance C-kinase activity also that the increased activity of the enzyme is involved in the chain of events leading to the stimulation of superoxide generation in fatty acid-treated neutrophils. PMID:3015427

Morimoto, Y M; Sato, E; Nobori, K; Takahashi, R; Utsumi, K

1986-06-01

50

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

51

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

52

Late preventive effects against carbon tetrachloride-induced liver necrosis of the calcium chelating agent Calcion.  

PubMed

In agreement with the hypothesis that changes in calcium homeostasis might be significant in late stages of chemically-induced liver cell injury, a calcium chelating agent, Calcion, was able to partially prevent CCl4-induced liver necrosis observed at 24 h, when treatment was given as late as 6 or 10 h after the hepatotoxin. Calcion had minor or no effects on covalent binding of reactive metabolites to cellular components, or on lipid peroxidation or on CCl4 levels reaching the liver. Calcion treatment of CCl4-poisoned animals decreased CCl4-induced calcium increases in liver and increased glutathione levels decreased by hepatotoxin at 24 h. Calcion treatment was not able to prevent CCl4-induced fatty liver. Calcion protective effects were body temperature dependent but they were cancelled when Calcion-treated poisoned animals were kept normothermic. Results suggest that Calcion protective effects might be linked to calcium chelation or alternatively that they might derive from decreases in body temperature. PMID:2619559

de Ferreyra, E C; Villarruel, M C; Bernacchi, A S; Fernández, G; de Fenos, O M; Castro, J A

1989-01-01

53

Arachidonic Acid and Prostaglandins Enhance Potassium-Stimulated Calcium InFlux into Rat Brain Synaptosomes.  

National Technical Information Service (NTIS)

Exogenous administration of arachidonic acid, prostaglandins PGF2 alpha, PGD2 and PGE2 increased potassium-stimulated uptake of calcium in rat brain synaptosomes from the brain of the rat, but had no effect on the basal uptake of calcium. Arachidonic acid...

S. B. Kandasamy W. A. Hunt

1990-01-01

54

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

55

High-Melting Lubricants Based on Complex Calcium Soaps of Commercial Synthetic Fatty Acids.  

National Technical Information Service (NTIS)

Synthetic fatty acids can be used in the production of high-quality complex calcium lubricants which can be used in a wide range of temperatures. The best calcium lubricants are obtained when using the wide heat-treated and distilled fraction of acids C10...

M. B. Nakonechnaya N. S. Goshko V. V. Sinitsyn Y. L. Ishchuk

1969-01-01

56

Intraluminal calcium binding does not mediate fatty acid-induced pancreatic bicarbonate secretion  

Microsoft Academic Search

Summary  Since the chain length dependency of fatty acid-induced pancreatic exocrine secretion parallels that of fatty acid-induced\\u000a inhibition of gastric emptying, similar mechanisms of action may be involved. An earlier study suggested that binding of calcium\\u000a might mediate fatty acid-induced inhibition of gastric emptying. This study investigated possible mediation of fatty acid-induced\\u000a pancreatic secretion by calcium binding. Pancreatic secretory response to

Aaron S. Fink; Mark Irving; James H. Meyer

1989-01-01

57

Effect of Potential Renal Acid Load of Foods on Calcium Metabolism of Renal Calcium Stone Formers  

Microsoft Academic Search

Objectives: Diet has been proposed as a causative factor of hypercalciuria in patients with calcium stones. The aim of this study was to investigate the influence of diet on calcium metabolism of renal stone formers. Methods: Thirty-five renal calcium stone formers were entered in this study. A 2-day recall of dietary intake was obtained from each subject. The food records

Alberto Trinchieri; Giampaolo Zanetti; Anna Currò; Renata Lizzano

2001-01-01

58

Unsaturated fatty acids induce calcium influx into keratinocytes and cause abnormal differentiation of epidermis.  

PubMed

Abnormal follicular keratinization is involved in comedogenesis in acne vulgaris. We recently demonstrated that calcium influx into epidermal keratinocytes is associated with impaired skin barrier function and epidermal proliferation. Based on these results, we hypothesized that sebum components affect calcium dynamics in the keratinocyte and consequently induce abnormal keratinization. To test this idea, we first observed the effects of topical application of sebum components, triglycerides (triolein), saturated fatty acids (palmitic acid and stearic acid), and unsaturated fatty acids (oleic acid and palmitoleic acid) on hairless mouse skin. Neither triglyceride nor saturated fatty acids affected the skin surface morphology or epidermal proliferation. On the other hand, application of unsaturated fatty acids, oleic acid, and palmitoleic acid induced scaly skin, abnormal keratinization, and epidermal hyperplasia. Application of triglycerides and saturated fatty acids on cultured human keratinocytes did not affect the intracellular calcium concentration ([Ca(2+)](i)), whereas unsaturated fatty acids increased the [Ca(2+)](i) of the keratinocytes. Moreover, application of oleic acid on hairless mouse skin induced an abnormal calcium distribution in the epidermis. These results suggest that unsaturated fatty acids in sebum alter the calcium dynamics in epidermal keratinocytes and induce abnormal follicular keratinization. PMID:15854043

Katsuta, Yuji; Iida, Toshii; Inomata, Shinji; Denda, Mitsuhiro

2005-05-01

59

Polyunsaturated fatty acids modulate sodium and calcium currents in CA1 neurons.  

PubMed Central

Recent evidence indicates that long-chain polyunsaturated fatty acids (PUFAs) can prevent cardiac arrhythmias by a reduction of cardiomyocyte excitability. This was shown to be due to a modulation of the voltage-dependent inactivation of both sodium (INa) and calcium (ICa) currents. To establish whether PUFAs also regulate neuronal excitability, the effects of PUFAs on INa and ICa were assessed in CA1 neurons freshly isolated from the rat hippocampus. Extracellular application of PUFAs produced a concentration-dependent shift of the voltage dependence of inactivation of both INa and ICa to more hyperpolarized potentials. Consequently, they accelerated the inactivation and retarded the recovery from inactivation. The EC50 for the shift of the INa steady-state inactivation curve was 2.1 +/- 0.4 microM for docosahexaenoic acid (DHA) and 4 +/- 0.4 microM for eicosapentaenoic acid (EPA). The EC50 for the shift on the ICa inactivation curve was 2.1 +/- 0.4 for DHA and > 15 microM for EPA. Additionally, DHA and EPA suppressed both INa and ICa amplitude at concentrations > 10 microM. PUFAs did not affect the voltage dependence of activation. The monounsaturated oleic acid and the saturated palmitic acid were virtually ineffective. The combined effects of the PUFAs on INa and ICa may reduce neuronal excitability and may exert anticonvulsive effects in vivo.

Vreugdenhil, M; Bruehl, C; Voskuyl, R A; Kang, J X; Leaf, A; Wadman, W J

1996-01-01

60

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

61

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

62

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

63

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

64

Randomized Controlled Trial of Febuxostat Versus Allopurinol or Placebo in Individuals with Higher Urinary Uric Acid Excretion and Calcium Stones  

PubMed Central

Summary Background and objectives Higher urinary uric acid excretion is a suspected risk factor for calcium oxalate stone formation. Febuxostat, a xanthine oxidoreductase inhibitor, is effective in lowering serum urate concentration and urinary uric acid excretion in healthy volunteers and people with gout. This work studied whether febuxostat, compared with allopurinol and placebo, would reduce 24-hour urinary uric acid excretion and prevent stone growth or new stone formation. Design, setting, participants, & measurements In this 6-month, double-blind, multicenter, randomized controlled trial, hyperuricosuric participants with a recent history of calcium stones and one or more radio-opaque calcium stone ?3 mm (as seen by multidetector computed tomography) received daily febuxostat at 80 mg, allopurinol at 300 mg, or placebo. The primary end point was percent change from baseline to month 6 in 24-hour urinary uric acid. Secondary end points included percent change from baseline to month 6 in size of index stone and change from baseline in the mean number of stones and 24-hour creatinine clearance. Results Of 99 enrolled participants, 86 participants completed the study. Febuxostat led to significantly greater reduction in 24-hour urinary uric acid (?58.6%) than either allopurinol (?36.4%; P=0.003) or placebo (?12.7%; P<0.001). Percent change from baseline in the size of the largest calcium stone was not different with febuxostat compared with allopurinol or placebo. There was no change in stone size, stone number, or renal function. No new safety concerns were noted for either drug. Conclusions Febuxostat (80 mg) lowered 24-hour urinary uric acid significantly more than allopurinol (300 mg) in stone formers with higher urinary uric acid excretion after 6 months of treatment. There was no change in stone size or number over the 6-month period.

MacDonald, Patricia A.; Gunawardhana, Lhanoo; Chefo, Solomon; McLean, Lachy

2013-01-01

65

Calcium phosphate cements prepared by acid-base reaction  

SciTech Connect

In this paper, the authors investigate the characteristics of calcium phosphate cements (CPC) prepared by an exothermic acid-base reaction between NH[sub 4]H[sub 2]PO[sub 4]-based fertilizer (Poly-N) and calcium aluminate compounds (CAC), such as 3CaO[center dot]Al[sub 2]O[sub 3] (C[sub 3]A), CaO[center dot] Al[sub 2]O[sub 3] (CA), and CaO[center dot] 2Al[sub 2]O[sub 3] (CA[sub 2]), in a series of integrated studies of reaction kinetics, interfacial reactions, in-situ phase transformations, and microstructure development. Two groups were compared: untreated and hydrothermally treated CPC specimens. The extent of reactivity of CAC with Poly-N at 25[degrees]C was in the following order: CA [gt] C[sub 3]A much+[gt] CA[sub 2]. The formation of a NH[sub 4]CaPO[sub 4][center dot]xH[sub 2]O salt during this reaction was responsible for the development of strength in the CPC specimens. The in-situ phase transformation of amorphous NH[sub 4]CaPO[sub 4][center dot]xH8[sub 2]O into crystalline Ca[sub 5](PO[sub 4])[sub 3](OH) and the conversion of hydrous Al[sub 2]O[sub 3] gel [yields] [gamma]-AlOOH occur in cement bodies during exposure in an autoclave to temperatures up to 300[degrees]C.

Sugama, T.; Allan, M. (Brookhaven National Lab., Upton, NY (United States). Applied Science Dept.)

1992-08-01

66

Unique roles of acidic amino acids in phase transformation of calcium phosphates.  

PubMed

Although phase transformation is suggested as a key step in biomineralization, the chemical scenario about how organic molecules mediate inorganic phase transformations is still unclear. The inhibitory effect of amino acids on hydroxyapatite (HAP, the main inorganic component of biological hard tissues such as bone and enamel) formation was concluded by the previous biomimetic modeling based upon direct solution crystallization. Here we demonstrate that acidic amino acids, Asp and Glu, could promote HAP crystallization from its precursor crystal, brushite (DCPD). However, such a promotion effect could not be observed when the nonacidic amino acids were applied in the transformation-based HAP formation. We found that the specific modification of acidic amino acid on crystal-solution interfaces played a key role in the phase transition. The distinct properties between DCPD and HAP in the solution resulted in an interfacial energy barrier to suppress the spontaneous formation of HAP phase on DCPD phase. Different from the other amino acids, the carboxylate-rich amino acids, Asp and Glu, could modify the interfacial characteristics of these two calcium phosphate crystals to make them similar to each other. The experiments confirmed that the involvement of Asp or Glu reduced the interfacial energy barrier between DCPD and HAP, leading to a trigger effect on the phase transformation. An in-depth understanding about the unique roles of acidic amino acids may contribute to understanding phase transformation controls druing biomineralization. PMID:21190387

Chu, Xiaobin; Jiang, Wenge; Zhang, Zhisen; Yan, Yang; Pan, Haihua; Xu, Xurong; Tang, Ruikang

2011-02-10

67

Calcium channel blocker prevents stress-induced activation of renin and aldosterone in conscious pig  

SciTech Connect

A considerable amount of data suggest the involvement of calcium-mediated processes in the activation of the renin-angiotensin-aldosterone (RAA) cascade. To investigate the effect of calcium-channel inhibition on the RAA system, the authors studied 21 conscious pigs. Blood renin and aldosterone levels increased by subjecting animals to 24 hours of immobilization stress. Renin and aldosterone levels were repeatedly measured by radioimmunoassay in blood samples taken periodically over 24 hours from a chronically implanted arterial cannula. Pretreatment of the animals (N = 11) with nisoldipine, 2 {times} 20 mg p.o. daily for 2 days before and on the day of immobilization, transiently attenuated the stress-induced increase of plasma renin activity and completely prevented the rise of aldosterone, as compared to nontreated controls (N = 10). The finding that nisoldipine suppresses RAA activation induced by a nonpharmacologic stimulus in the conscious intact animal may have clinical implications.

Ceremuzynski, L.K.; Klos, J.; Barcikowski, B.; Herbaczynska-Cedro, K. (Department of Cardiology, Postgraduate Medical School, Warsaw (Poland))

1991-06-01

68

Evolution of EF-hand calcium-modulated proteins. I. Relationships based on amino acid sequences  

Microsoft Academic Search

Summary The relationships among 153 EF-hand (calcium-modulated) proteins of known amino acid sequence were determined using the method of maximum parsimony. These proteins can be ordered into 12 distinct subfamilies-calmodulin, troponin C, essential light chain of myosin, regulatory light chain, sarcoplasmic calcium binding protein, calpain, aequorin,Strongylocentrotus purpuratus ectodermal protein, calbindin 28 kd, parvalbumin, ?-actinin, and S100\\/intestinal calcium-binding protein. Eight individual

Nancy D. Moncrief; Robert H. Kretsinger; Morris Goodman

1990-01-01

69

Aspirin plus calcium supplementation to prevent superimposed preeclampsia: a randomized trial.  

PubMed

Preeclampsia is an important cause of maternal and perinatal morbidity and mortality. Previous studies have tested calcium supplementation and aspirin separately to reduce the incidence of preeclampsia but not the effects of combined supplementation. The objective of this study was to investigate the effectiveness of aspirin combined with calcium supplementation to prevent preeclampsia in women with chronic hypertension. A double-blind, placebo-controlled randomized clinical trial was carried out at the antenatal clinic of a large university hospital in São Paulo, SP, Brazil. A total of 49 women with chronic hypertension and abnormal uterine artery Doppler at 20-27 weeks gestation were randomly assigned to receive placebo (N = 26) or 100 mg aspirin plus 2 g calcium (N = 23) daily until delivery. The main outcome of this pilot study was development of superimposed preeclampsia. Secondary outcomes were fetal growth restriction and preterm birth. The rate of superimposed preeclampsia was 28.6% lower among women receiving aspirin plus calcium than in the placebo group (52.2 vs 73.1%, respectively, P=0.112). The rate of fetal growth restriction was reduced by 80.8% in the supplemented group (25 vs 4.8% in the placebo vs supplemented groups, respectively; P=0.073). The rate of preterm birth was 33.3% in both groups. The combined supplementation of aspirin and calcium starting at 20-27 weeks of gestation produced a nonsignificant decrease in the incidence of superimposed preeclampsia and fetal growth restriction in hypertensive women with abnormal uterine artery Doppler. PMID:24728212

Souza, E V; Torloni, M R; Atallah, A N; Dos Santos, G M S; Kulay, L; Sass, N

2014-05-01

70

Aspirin plus calcium supplementation to prevent superimposed preeclampsia: a randomized trial  

PubMed Central

Preeclampsia is an important cause of maternal and perinatal morbidity and mortality. Previous studies have tested calcium supplementation and aspirin separately to reduce the incidence of preeclampsia but not the effects of combined supplementation. The objective of this study was to investigate the effectiveness of aspirin combined with calcium supplementation to prevent preeclampsia in women with chronic hypertension. A double-blind, placebo-controlled randomized clinical trial was carried out at the antenatal clinic of a large university hospital in São Paulo, SP, Brazil. A total of 49 women with chronic hypertension and abnormal uterine artery Doppler at 20-27 weeks gestation were randomly assigned to receive placebo (N = 26) or 100 mg aspirin plus 2 g calcium (N = 23) daily until delivery. The main outcome of this pilot study was development of superimposed preeclampsia. Secondary outcomes were fetal growth restriction and preterm birth. The rate of superimposed preeclampsia was 28.6% lower among women receiving aspirin plus calcium than in the placebo group (52.2 vs 73.1%, respectively, P=0.112). The rate of fetal growth restriction was reduced by 80.8% in the supplemented group (25 vs 4.8% in the placebo vs supplemented groups, respectively; P=0.073). The rate of preterm birth was 33.3% in both groups. The combined supplementation of aspirin and calcium starting at 20-27 weeks of gestation produced a nonsignificant decrease in the incidence of superimposed preeclampsia and fetal growth restriction in hypertensive women with abnormal uterine artery Doppler.

Souza, E.V.; Torloni, M.R.; Atallah, A.N.; dos Santos, G.M.S.; Kulay, L.; Sass, N.

2014-01-01

71

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

72

A new CO 2 disposal process via artificial weathering of calcium silicate accelerated by acetic acid  

Microsoft Academic Search

A new disposal process for anthropogenic CO2 via an artificially accelerated weathering reaction is proposed to counteract global warming. The process is essentially composed of the following two steps:(1)CaSiO3+2CH3COOH?Ca2++2CH3COO?+H2O+SiO2(2)Ca2++2CH3COO?+CO2+H2O?CaCO3?+2CH3COOHStep (1) is the extraction of calcium ions by acetic acid from calcium silicate, for example, wollastonite rocks. Step (2) is the deposition of calcium carbonate from the solution of calcium ions

M. Kakizawa; A. Yamasaki; Y. Yanagisawa

2001-01-01

73

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.

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

2010-01-01

74

Complex forming properties of natural organic acids. Pt. 2. Complexes with iron and calcium.  

National Technical Information Service (NTIS)

An ultrafiltration technique combined with ion-selective-electrode and atomic absorption methods have been employed to obtain information on the complex forming properties of fulvic acid with iron and calcium. A model for interpreting complexation of meta...

J. H. Ephraim A. S. Mathuthu J. A. Marinsky

1990-01-01

75

Effect of calcium ion on the fouling of nanofilter by humic acid in drinking water production  

Microsoft Academic Search

The influence of the charge of humic acid (HA) on the fouling of nanofilters was investigated as a function of pH and concentration of calcium ions. The charge of the humic acid as well as the zeta-potential of the membrane surface were measured to elucidate the mechanism of humic acid deposition on the membrane surface. The negative charge of humic

Seong-Hoon Yoon; Chung-Hak Lee; Kyu-Jin Kim; Anthony G. Fane

1998-01-01

76

The Effect of Calcium Carbonate on the Stability of Acid Treated Papers.  

National Technical Information Service (NTIS)

Exposure of kraft wood pulps to an acidic medium results in a destabilization of wood pulp. The degree of destabilization appears to depend on the concentration of acid the pulp is exposed to. The addition of calcium carbonate to acid destabilized pulp do...

E. L. Graminski E. J. Parks

1980-01-01

77

Polycarboxylic acids containing acetal functions: calcium sequestering compounds based on oxidized carbohydrates  

Microsoft Academic Search

A number of polycarboxylic acids containing acetal functions have been prepared by a two-step oxidation of carbohydrates.\\u000a Their calcium sequestering behavior is compared with that of a series of model polycarboxylic acids. It is found that calcium\\u000a sequestration by oxidized carbohydrates is less than that by corresponding ether polycarboxylates, since (a) acetal oxygens\\u000a have a lower coordinating power than ether

M. S. Nieuwenhuizen; A. P. G. Kieboom; H. van Bekkum

1983-01-01

78

Effect of Fatty Acids or Calcium Soaps on Rumen and Total Nutrient Digestibility of Dairy Rations1  

Microsoft Academic Search

Two trials ascertained whether feeding fatty acids as preformed calcium soaps would permit normal digestibility of fiber without reducing availabilities of fatty acids or energy. Six diets contained no added fat (control) or the equivalent of 4.5% added fatty acids as tallow or soy fatty acids, tallow or soy calcium soaps, or tallow combined with the nonnutritive carrier verxite. Six

T. C. Jenkins; D. L. Palmquist

1984-01-01

79

The effect of different n-6 n-3 essential fatty acid ratios on calcium balance and bone in rats  

Microsoft Academic Search

Prostaglandins (PGs) are known to have various effects on bone metabolism. The supplementation of essential fatty acids (EFAs), the precursors of PGs, leads to increased intestinal calcium absorption and calcium balance. It is, however, not known whether increased calcium absorption and calcium balance will enhance the calcium content in bone.Male Sprague-Dawley rats (n = 40) aged 5–12 weeks were supplemented

N. Claassen; H. Coetzer; C. M. L. Steinmann; M. C. Kruger

1995-01-01

80

Long-chain fatty acids activate calcium channels in ventricular myocytes.  

PubMed Central

Nonesterified fatty acids accumulate at sites of tissue injury and necrosis. In cardiac tissue the concentrations of oleic acid, arachidonic acid, leukotrienes, and other fatty acids increase greatly during ischemia due to receptor or nonreceptor-mediated activation of phospholipases and/or diminished reacylation. In ischemic myocardium, the time course of increase in fatty acids and tissue calcium closely parallels irreversible cardiac damage. We postulated that fatty acids released from membrane phospholipids may be involved in the increase of intracellular calcium. We report here that low concentrations (3-30 microM) of each long-chain unsaturated (oleic, linoleic, linolenic, and arachidonic) and saturated (palmitic, stearic, and arachidic) fatty acid tested induced multifold increases in voltage-dependent calcium currents (ICa) in cardiac myocytes. In contrast, neither short-chain fatty acids (less than 12 carbons) or fatty acid esters (oleic and palmitic methyl esters) had any effect on ICa, indicating that activation of calcium channels depended on chain length and required a free carboxyl group. Inhibition of protein kinases C and A, G proteins, eicosanoid production, or nonenzymatic oxidation did not block the fatty acid-induced increase in ICa. Thus, long-chain fatty acids appear to directly activate ICa, possibly by acting at some lipid sites near the channels or directly on the channel protein itself. We suggest that the combined effects of fatty acids released during ischemia on ICa may contribute to ischemia-induced pathogenic events on the heart that involve calcium, such as arrhythmias, conduction disturbances, and myocardial damage due to cytotoxic calcium overload.

Huang, J M; Xian, H; Bacaner, M

1992-01-01

81

Long-Chain Fatty Acids Activate Calcium Channels in Ventricular Myocytes  

NASA Astrophysics Data System (ADS)

Nonesterified fatty acids accumulate at sites of tissue injury and necrosis. In cardiac tissue the concentrations of oleic acid, arachidonic acid, leukotrienes, and other fatty acids increase greatly during ischemia due to receptor or nonreceptor-mediated activation of phospholipases and/or diminished reacylation. In ischemic myocardium, the time course of increase in fatty acids and tissue calcium closely parallels irreversible cardiac damage. We postulated that fatty acids released from membrane phospholipids may be involved in the increase of intracellular calcium. We report here that low concentrations (3-30 ?M) of each long-chain unsaturated (oleic, linoleic, linolenic, and arachidonic) and saturated (palmitic, stearic, and arachidic) fatty acid tested induced multifold increases in voltage-dependent calcium currents (ICa) in cardiac myocytes. In contrast, neither short-chain fatty acids (<12 carbons) or fatty acid esters (oleic and palmitic methyl esters) had any effect on ICa, indicating that activation of calcium channels depended on chain length and required a free carboxyl group. Inhibition of protein kinases C and A, G proteins, eicosanoid production, or nonenzymatic oxidation did not block the fatty acid-induced increase in ICa. Thus, long-chain fatty acids appear to directly activate ICa, possibly by acting at some lipid sites near the channels or directly on the channel protein itself. We suggest that the combined effects of fatty acids released during ischemia on ICa may contribute to ischemia-induced pathogenic events on the heart that involve calcium, such as arrhythmias, conduction disturbances, and myocardial damage due to cytotoxic calcium overload.

Huang, James Min-Che; Xian, Hu; Bacaner, Marvin

1992-07-01

82

Effects of high calcium intake on fat digestion and bile acid excretion in feces of veal calves.  

PubMed

We tested the hypothesis that apparent digestibility of fat by veal calves is determined by the participation of bile acids in the process of fat absorption and is, therefore, negatively associated with bile acid excretion in feces. Veal calves were fed milk replacers that contained whey protein and either a low (5.2 g of calcium/kg of air-dried diet) or high (12.4 g of calcium/kg of air-dried diet) concentration of calcium. The high calcium milk replacer contained extra calcium in the form of calcium formate. Final body weight was not significantly influenced by diet after the milk replacers had been fed for 27 wk. Feces were quantitatively collected during wk 23 of the trial. The high calcium milk replacer reduced apparent fat digestibility by 5.6 percentage units and increased bile acid excretion in feces by 90% compared with the low calcium milk replacer. The extra calcium intake decreased apparent absorption of magnesium and phosphorus. We proposed that a high intake of calcium by veal calves would increase the amount of insoluble calcium, magnesium, and phosphate complexes in the intestinal lumen, which, because of the binding of bile acids, would exclude bile acids from the process of fat digestion and inhibit reabsorption of bile acids. As a result, fat digestion is impaired, and bile acid excretion in feces is enhanced. The complex formation in the ileal lumen also explains why high calcium intake reduces magnesium and phosphorus absorption in veal calves. PMID:9749383

Xu, C; Wensing, T; Beynen, A C

1998-08-01

83

Prevention of calcium carbonate precipitation from calcium chloride kill fluid in CO/sub 2/-laden formations  

SciTech Connect

Water containing high concentrations of calcium chloride can now be efficiently used as a kill fluid in production wells having heavily laden carbon dioxide formations. This investigation has determined that the amount of calcium carbonate scale normally produced under these conditions can be reduced by increasing the carbon dioxide partial pressure and increasing the tubing pressure leading from the casing annulus.

Kapelke, M.S.; Caballero, E.P.

1984-04-01

84

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.

2013-01-01

85

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol  

SciTech Connect

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of {sup 51}Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in {sup 51}Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal {sup 51}Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol.

Miller, M.J.; Zhang, x.J.; Gu, x.A.; Clark, D.A. (Department of Pediatrics, Louisiana State University School of Medicine, New Orleans (USA))

1991-07-01

86

Mechanism of action of a desensitizing fluoride toothpaste delivering calcium and phosphate ingredients in the treatment of dental hypersensitivity. Part III: Prevention of dye penetration through dentin vs a calcium- and phosphate-free control.  

PubMed

It is generally accepted that the pain of dental hypersensitivity resulting from gum recession is from the movement of fluid within the exposed tubules of dentin, causing changes in pressure on the nerve within the pulpal cavity. One method of treating hypersensitivity is to occlude the tubules, preventing fluid movement. This article discusses the use of a dye penetration technique, which establishes this mechanism of action for a desensitizing fluoride toothpaste containing calcium and phosphate. Two groups of intact teeth were perfectly sealed with enamel paint. Windows 100-micro to 200-micro deep were opened on opposite sides of each tooth at the dentin-enamel junction and briefly etched using 20% polyacrylic acid. One batch of teeth was treated eight times for 30 mins each with a 1:3 slurry of the desensitizing toothpaste and another set with a similar slurry prepared from a calcium- and phosphate-free control. A 0.85% aqueous solution of acid red fuchsin dye was applied to each window and allowed to dry. After a brief rinse, the teeth were sectioned across the windows. Almost no dye penetration was seen in teeth treated with the desensitizing toothpaste; however, extensive penetration through the dentin was visible in the control-treated teeth. The differences in dye penetration for the two sets of teeth were significant by both subjective (P < .001) and objective (P < .01) measures. Tubule occlusion because of calcium and phosphate ions from the desensitizing toothpaste accounts for its tooth desensitizing efficacy. PMID:20158016

Winston, Anthony E; Charig, Andrew J; Thong, Stephen

2010-01-01

87

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

88

L-Ascorbic acid and L-galactose are sources for oxalic acid and calcium oxalate in Pistia stratiotes  

Microsoft Academic Search

Axenic Pistia stratiotes L. plants were pulse-chase labeled with [14C]oxalic acid, L-[1-14C]ascorbic acid, L-[6-14C]ascorbic acid, D-[1-14C]erythorbic acid, L-[1-14C]galactose, or [1-14C]glycolate. Specific radioactivities of L-ascorbic acid (AsA), free oxalic acid (OxA) and calcium oxalate (CaOx) in labeled plants were compared. Samples of leaf tissue were fixed for microautoradiography and examined by confocal microscopy. Results demonstrate a biosynthetic role for AsA as

Sarah E. Keates; Nathan M. Tarlyn; Frank A. Loewus; Vincent R. Franceschi

2000-01-01

89

Role of boric acid in synthesis and tailoring the properties of calcium aluminate phosphor  

Microsoft Academic Search

In the present work related to the development of high-luminous blue-emitting calcium aluminate phosphor, the active role of boric acid (H3BO3) as a chemical additive is identified. The appropriate usage of H3BO3 in defining the crystal structure, morphology and momentous variation in luminescent properties of calcium aluminate long persisting (LP) phosphor is systematically studied and presented. The results attribute two

D. Haranath; Pooja Sharma; Harish Chander; Anwar Ali; Nitesh Bhalla; S. K. Halder

2007-01-01

90

Templating route for mesostructured calcium phosphates with carboxylic acid- and amine-type surfactants.  

PubMed

Mesostructured calcium phosphates constructed by ionic frameworks were synthesized using carboxylic acid- and amine-type surfactants in mixed solvent systems of ethanol and water. A lamellar mesostructured calcium phosphate was prepared using palmitic acid as an anionic surfactant, as in the case using n-alkylamines. A wormhole-like mesostructured calcium phosphate can be obtained using dicarboxyl N-lauroyl- l-glutamic acid, whose headgroup is larger than that of palmitic acid. Similar mesostructured product was obtained using 4-dodecyldiethylenetriamine with a large headgroup containing two primary amine groups. Interactions of carboxyl and primary amino groups in the surfactant molecules with inorganic species are quite important for the formation of mesostructured calcium phosphates. The Ca/P molar ratio of mesostructured calcium phosphates was strongly affected by the molecular structure of surfactants containing carboxyl and primary amino groups. Ca-rich materials can be obtained using carboxylic acid-type surfactants (Ca/P approximately 1.7) rather than amine-type surfactants (Ca/P approximately 1.0). PMID:18947246

Ikawa, Nobuaki; Hori, Hideki; Kimura, Tatsuo; Oumi, Yasunori; Sano, Tsuneji

2008-11-18

91

Loading of amphipathic weak acids into liposomes in response to transmembrane calcium acetate gradients.  

PubMed

We describe a novel procedure to load amphipathic weak acid molecules into preformed liposomes. Differences in calcium acetate concentrations across the liposomal membrane induce an increase of the internal pH. This pH imbalance serves as an efficient driving force to load and accumulate weak acids (5(6)-carboxyfluorescein and nalidixic acid) inside the lipid vesicles. The mechanism of loading and the relevance of the method in drug delivery systems are discussed. PMID:8541297

Clerc, S; Barenholz, Y

1995-12-13

92

Loading of amphipathic weak acids into liposomes in response to transmembrane calcium acetate gradients  

Microsoft Academic Search

We describe a novel procedure to load amphipathic weak acid molecules into preformed liposomes. Differences in calcium acetate concentrations across the liposomal membrane induce an increase of the internal pH. This pH imbalance serves as an efficient driving force to load and accumulate weak acids (5(6)-carboxyfluorescein and nalidixic acid) inside the lipid vesicles. The mechanism of loading and the relevance

Stéphane Clerc; Yechezkel Barenholz

1995-01-01

93

Determination of C 80 tetra-acid content in calcium naphthenate deposits  

Microsoft Academic Search

A method is described which allows to determine the content of the so-called C80 tetra-acid molecules (TA) in calcium naphthenate deposits. The method consists of four steps. Molecules present in the deposit are dissolved in a mixture of toluene and 2-butanol after an acidic treatment. All acid molecules are then selectively extracted and concentrated by a solid-phase extraction (SPE) method.

Sébastien Simon; Erland Nordgård; Per Bruheim; Johan Sjöblom

2008-01-01

94

Recovery of calcium carbonate from steelmaking slag and utilization for acid mine drainage pre-treatment.  

PubMed

The conversion of steelmaking slag (a waste product of the steelmaking process) to calcium carbonate (CaCO(3)) was tested using hydrochloric acid, ammonium hydroxide and carbon dioxide via a pH-swing process. Batch reactors were used to assess the technical feasibility of calcium carbonate recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effects of key process parameters, such as the amount of acid (HCl/calcium molar ratio), the pH and the CO(2) flow rate were considered. It was observed that calcium extraction from steelmaking slag significantly increased with an increase in the amount of hydrochloric acid. The CO(2) flow rate also had a positive effect on the carbonation reaction rate but did not affect the morphology of the calcium carbonate produced for values less than 2 L/min. The CaCO(3) recovered from the bench scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with the commercial laboratory grade CaCO(3). PMID:22643421

Mulopo, J; Mashego, M; Zvimba, J N

2012-01-01

95

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.

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

2014-01-01

96

The Role of Polycarboxylic Acids in Calcium Phosphate Mineralization  

Microsoft Academic Search

The role of two polyelectrolytes, poly-L-glutamate and poly-L-aspartate, in the growth of calcium phosphate crystal phases, has been investigated at constant supersaturation. Both molecules are strong inhibitors of HAP growth when present in the solution phase but also act as hydroxyapatite and (octacalcium phosphate)-like crystal nucleators when adsorbed on germanium surfaces. The structure of the polymers in solution is presented

Achilles Tsortos; George H. Nancollas

2002-01-01

97

The calcium sensing receptor modulates fluid reabsorption and acid secretion in the proximal tubule.  

PubMed

The proximal tubule uses a complex process of apical acid secretion and basolateral bicarbonate absorption to regulate both luminal acidification and fluid absorption. One of the primary regulators of apical acid secretion is the luminal sodium-hydrogen exchanger expressed along the apical membrane of the proximal tubule. Similarly, the calcium-sensing receptor (CaSR) is also located along the luminal membrane of the proximal tubule. Here we investigated the role of CaSR in proton secretion and fluid reabsorption in proximal tubules by modulating luminal calcium concentration, using both in vivo micropuncture in rats and in vitro perfused mouse proximal tubules. Using CaSR knockout mice and a calcimimetic agent, we found that increased proton secretion and fluid reabsorption were CaSR dependent. Activating CaSR by either raising the luminal calcium ion concentration or by the calcimimetic caused a concomitant increase in sodium-dependent proton extrusion and fluid reabsorption, whereas in proximal tubules isolated from CaSR knockout mice varying calcium ion concentration had no effect. Application of a calcimimetic in lower concentrations of calcium ion stimulated these processes in vitro and in vivo. Thus, in both rats and mice, increased luminal calcium concentration leads to enhanced fluid reabsorption in the proximal tubule, a process related to activation of CaSR. PMID:23615500

Capasso, Giovambattista; Geibel, Peter J; Damiano, Sara; Jaeger, Philippe; Richards, William G; Geibel, John P

2013-08-01

98

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

99

Determination of C(80) tetra-acid content in calcium naphthenate deposits.  

PubMed

A method is described which allows to determine the content of the so-called C(80) tetra-acid molecules (TA) in calcium naphthenate deposits. The method consists of four steps. Molecules present in the deposit are dissolved in a mixture of toluene and 2-butanol after an acidic treatment. All acid molecules are then selectively extracted and concentrated by a solid-phase extraction (SPE) method. After derivatization of acids into their naphthacyl esters to increase the sensitivity of the detection, TA is separated and detected by reversed-phase HPLC with UV detection. We have checked that all the steps are quantitative and the method appears selective. The TA content can be determined in presence of other naphthenic acids. Using this methodology we have determined the TA content in three calcium naphthenate deposits from different oil fields. It appears that these deposits have a similar TA concentration between 28 and 41% (w/w). PMID:18556007

Simon, Sébastien; Nordgård, Erland; Bruheim, Per; Sjöblom, Johan

2008-07-25

100

Adsorption and release of amino acids mixture onto apatitic calcium phosphates analogous to bone mineral  

NASA Astrophysics Data System (ADS)

Study focused on the interaction of adsorbate with poorly crystalline apatitic calcium phosphates analogous to bone mineral. Calcium phosphates prepared in water-ethanol medium at physiological temperature (37 °C) and neutral pH, their Ca/P ratio was between 1.33 and 1.67. Adsorbate used in this paper takes the mixture form of two essential amino acids L-lysine and DL-leucine which have respectively a character hydrophilic and hydrophobic. Adsorption and release are investigated experimentally; they are dependent on the phosphate type and on the nature of adsorbate L-lysine, DL-leucine and their mixture. Adsorption of mixture of amino acids on the apatitic calcium phosphates is influenced by the competition between the two amino acids: L-lysine and DL-leucine which exist in the medium reaction. The adsorption kinetics is very fast while the release kinetics is slow. The chemical composition of apatite has an influence on both adsorption and release. The interactions adsorbate-adsorbent are electrostatic type. Adsorption and release reactions of the amino acid mixture are explained by the existence of the hydrated surface layer of calcium phosphate apatite. The charged sbnd COOsbnd and sbnd NH3+ of adsorbates are the strongest groups that interact with the surface of apatites, the adsorption is mainly due to the electrostatic interaction between the groups sbnd COOsbnd of amino acids and calcium Ca2+ ions of the apatite. Comparative study of interactions between adsorbates (L-lysine, DL-leucine and their mixture) and apatitic calcium phosphates is carried out in vitro by using UV-vis and infrared spectroscopy IR techniques.

El Rhilassi, A.; Mourabet, M.; El Boujaady, H.; Bennani-Ziatni, M.; Hamri, R. El; Taitai, A.

2012-10-01

101

Activation of the calcium sensing receptor stimulates gastrin and gastric acid secretion in healthy participants  

PubMed Central

Summary In 17 adults on a fixed metabolic diet, an 11-day course of cinacalcet increased serum gastrin and basal gastric acid output, but not maximal gastric acid output, compared with a placebo. These findings indicate that the calcium sensor receptor plays a role in the regulation of gastric acid. Introduction Gastric acid secretion is a complex process regulated by neuronal and hormonal pathways. Ex vivo studies in human gastric tissues indicate that the calcium sensing receptor (CaR), expressed on the surface of G and parietal cells, may be involved in this regulation. We sought to determine whether cinacalcet, a CaR allosteric agonist, increases serum gastrin and gastric acid secretion. Methods Seventeen healthy adults with normal gastric acid output were placed on an 18-day metabolic diet. On day 8 (baseline), participants were given cinacalcet (15 then 30 mg/day) or placebo for 11 days. Changes in gastric acid output, serum gastrin, and other measures were compared in the two groups. Results Changes in serum gastrin and basal acid output (adjusted for baseline body weight) were significantly more positive in the cinacalcet group compared with placebo (P=0.004 and P=0.039 respectively). Change in maximal acid output was similar in the two groups (P=0.995). As expected, cinacalcet produced significant decreases in serum PTH (P<0.001) and ionized calcium levels (P=0.032), and increases in serum phosphorus levels (P=0.001) and urinary calcium (P=0.023). Conclusions This study provides in vivo evidence that activation of the CaR increases serum gastrin levels and basal gastric acid secretion in healthy adults.

Ceglia, L.; Harris, S. S.; Rasmussen, H. M.; Dawson-Hughes, B.

2009-01-01

102

Influence of calcium on the effects of okadaic acid and its interaction with caffeine and theophylline in rat myometrium  

Microsoft Academic Search

The effects of okadaic acid (OA), a monocarboxylic acid produced by marine dinoflagellates belonging to the genera Dinophysis and Prorocentrum, and their interactions with theophylline and caffeine were studied on the rat-isolated uterus in a calcium-containing medium and a calcium-free medium in the presence of 10-3 M EGTA.

M.-L. Candenas; E. Arteche; M. Norte; C. Advenier; J. D. Martín

1994-01-01

103

Hexavalent chromium damages chamomile plants by alteration of antioxidants and its uptake is prevented by calcium.  

PubMed

Toxicity of low (3?M) and high (60 and 120?M) concentrations of hexavalent chromium/Cr(VI) in chamomile plants was studied. Fluorescence staining confirmed reduction of Cr(VI) to Cr(III). Cr was mainly accumulated in the roots with translocation factor <0.007. Notwithstanding this, both shoots and roots revealed increase in oxidative stress and depletion of glutathione, total thiols, ascorbic acid and activities of glutathione reductase and partially ascorbate peroxidase mainly at 120?M Cr. Though some protective mechanisms were detected (elevation of nitric oxide, enhancement of GPX activity and increase in phenols and lignin), this was not sufficient to counteract the oxidative damage. Consequently, soluble proteins, tissue water content and biomass production were considerably depleted. Surprising increase in some mineral nutrients in roots (Ca, Fe, Zn and Cu) was also detected. Subsequent experiment confirmed that exogenous calcium suppressed oxidative symptoms and Cr uptake but growth of chamomile seedlings was not improved. Alteration of naturally present reductants could be a reason for Cr(III) signal detected using specific fluorescence reagent: in vitro assay confirmed disappearance of ascorbic acid in equimolar mixture with dichromate (>96% at pH 4 and 7) while such response of glutathione was substantially less visible. PMID:24727012

Ková?ik, Jozef; Babula, Petr; Hedbavny, Josef; Klejdus, Bo?ivoj

2014-05-30

104

Study of the chemical mechanisms of the reaction of neutralization of calcium hydroxide by phosphoric acid  

NASA Astrophysics Data System (ADS)

Calcium phosphates reported in this study, are prepared following an acido-basic reaction between phosphoric acid and calcium hydroxide. These phosphates are the brushite, tricalcium phosphate, hydroxyapatite and oxygenated apatite. The follow-up of the reaction by infra-red spectroscopy of absorption showed that the alkaline pH of calcium hydroxide solution, favours the formation of carbonated apatite, at the start of the reaction. Following the addition of phosphoric acid, the pH becomes increasingly favourable to the formation of the desired phase. The insertion of molecular oxygen in the apatitic tunnel is carried out by the use of hydrogen peroxide. The molecular oxygen rate in the apatite is then determined by volumetric analysis.

Elgadi, M.; Mejdoubi, E.; Elansari, L. L.; Essaddek, A.; Abouricha, S.; Lamhamdi, A.

2005-03-01

105

Protein, calcium, iron, and amino acid content of selected wild and domesticated cultivars of finger millet.  

PubMed

Two wild and eight domesticated cultivars of finger millet were analyzed to determine their proximate composition and calcium, iron, and amino acid content. Wide variations were observed in the protein (mean values ranged from 7.5 to 11.7%), calcium (376 to 515 mg/100 g), and iron (3.7 to 6.8 mg/100 g) content of the wild and domesticated cultivars. A wild progenitor of finger millet, E coracana subsp. africana was significantly higher in protein than four of the six domesticated accessions analyzed. The calcium and iron content of the wild progenitor was also significantly greater than that of two domesticated cultivars. The wild species was also found to be higher in lysine and five other essential amino acids. These results indicate that the nutritional value of finger millet may be significantly improved by selective crossbreeding of the cereal's wild and domesticated cultivars. PMID:8475005

Barbeau, W E; Hilu, K W

1993-03-01

106

Investigation of serum calcium, phosphorus, albumine uric acid and lipid parameters in sportsmen and sedanters.  

PubMed

In this study, it was aimed to investigate the differences in blood lipid fractions which are important risk factors for atherosclerosis and to show how the levels of serum albumin, uric acid, ionized calcium, inorganic phosphorus change with exercises between sportsmen and sedanters. 25 sportsmen and 25 sedanters (13 male, 12 female in each group) aged 18-23 were chosen for the study. From the venous blood samples taken from the two groups, levels of serum total lipid, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, triglyceride, albumin, uric acid, ionized calcium, inorganic phosphorus were analyzed. Student's t-test was used for the statistical analyses. There were some important changes in the levels of serum triglyceride, VLDL-cholesterol and ionized calcium of sportsmen compared to those of controls. PMID:10797858

Turgut, G; Genc, O; Kaptanoglu, B

1999-01-01

107

Precipitation of calcium phosphate from moderately acid solution  

NASA Astrophysics Data System (ADS)

The precipitation of calcium phosphate upon mixing of equimolar amounts of calcium nitrate and ammonium phosphate has been studied in the temperature range 40-60°C and pH 3.5-6.5. At the lowertemperatures, brushite, CaHPO 4, 2 H 2O, is the major crystalline product. Monetite, CaHPO 4, is formed at the higher temperatures and above a certain critical supersaturation, and OCP, Ca 4H(PO 4) 3.2.5H 2O, in the higher pH range. A metastable, amorphous tricalcium phosphate, Ca 3(PO 4) 2. xH2O, is formed initially if a(Ca 2+) 3a(PO 3-4) 2 exceeds a certain value, which decreases rapidly as temperature increases. The range in which brushite is found as the only crystalline phase narrows with increasing temperature. The results are explained in terms of heterogeneous nucleation for brushite and homogeneous nucleation for monetite.

Lundager Madsen, H. E.; Thorvardarson, G.

1984-04-01

108

Ursodeoxycholic and deoxycholic acids: A good and a bad bile acid for intestinal calcium absorption.  

PubMed

The aim of this study was to investigate the effect of ursodeoxycholic acid (UDCA) on intestinal Ca(2+) absorption and to find out whether the inhibition of this process caused by NaDOC could be prevented by UDCA. Chicks were employed and divided into four groups: (a) controls, (b) treated with 10mM NaDOC, (c) treated with 60 ?g UDCA/100g of b.w., and (d) treated with 10mM NaDOC and 60 ?g UDCA/100g of b.w. UDCA enhanced intestinal Ca(2+) absorption, which was time and dose-dependent. UDCA avoided the inhibition of intestinal Ca(2+) absorption caused by NaDOC. Both bile acids altered protein and gene expression of molecules involved in the transcellular pathway of intestinal Ca(2+) absorption, but in the opposite way. UDCA aborted the oxidative stress produced by NaDOC in the intestine. UDCA and UDCA plus NaDOC increased vitamin D receptor protein expression. In conclusion, UDCA is a beneficial bile acid for intestinal Ca(2+) absorption. Contrarily, NaDOC inhibits the intestinal cation absorption through triggering oxidative stress. The use of UDCA in patients with cholestasis would be benefited because of the protective effect on the intestinal Ca(2+) absorption, avoiding the inhibition caused by hydrophobic bile acids and neutralizing the oxidative stress. PMID:24096173

Rodríguez, Valeria; Rivoira, María; Marchionatti, Ana; Pérez, Adriana; Tolosa de Talamoni, Nori

2013-12-01

109

Effects of Calcium Deficiency on Potato Sets in Acid Soils  

Microsoft Academic Search

DURING the War, when many poor upland areas and commons in Britain were ploughed up for crop production, potatoes were commonly planted as a first crop in view of their tolerance to acid soil conditions. Many failures, however, were experienced where the soils were very strongly acid, with pH values of the order of 4.0, and it was shown that

T. Wallace; E. J. Hewitt

1948-01-01

110

Evaluation of the Health Aspects of Ascorbic Acid, Sodium Ascorbate, Calcium Ascorbate, Erythorbic Acid, Sodium Erythorbate, and Ascorbyl Palmitate as Food Ingredients.  

National Technical Information Service (NTIS)

The report, by a group of qualified scientists designated the Select Committee of GRAS Substances (SCOGS), provides an independent evaluation of the safety of ascorbic acid, sodium ascorbate, calcium ascorbate, erythorbic acid, sodium erythorbate, and asc...

1979-01-01

111

The Calcium-Sensing Receptor Promotes Urinary Acidification to Prevent Nephrolithiasis  

PubMed Central

Hypercalciuria increases the risk for urolithiasis, but renal adaptive mechanisms reduce this risk. For example, transient receptor potential vanilloid 5 knockout (TPRV5?/?) mice lack kidney stones despite urinary calcium (Ca2+) wasting and hyperphosphaturia, perhaps as a result of their significant polyuria and urinary acidification. Here, we investigated the mechanisms linking hypercalciuria with these adaptive mechanisms. Exposure of dissected mouse outer medullary collecting ducts to high (5.0 mM) extracellular Ca2+ stimulated H+-ATPase activity. In TRPV5?/? mice, activation of the renal Ca2+-sensing receptor promoted H+-ATPase–mediated H+ excretion and downregulation of aquaporin 2, leading to urinary acidification and polyuria, respectively. Gene ablation of the collecting duct-specific B1 subunit of H+-ATPase in TRPV5?/? mice abolished the enhanced urinary acidification, which resulted in severe tubular precipitations of Ca2+-phosphate in the renal medulla. In conclusion, activation of Ca2+-sensing receptor by increased luminal Ca2+ leads to urinary acidification and polyuria. These beneficial adaptations facilitate the excretion of large amounts of soluble Ca2+, which is crucial to prevent the formation of kidney stones.

Renkema, Kirsten Y.; Velic, Ana; Dijkman, Henry B.; Verkaart, Sjoerd; van der Kemp, Annemiete W.; Nowik, Marta; Timmermans, Kim; Doucet, Alain; Wagner, Carsten A.; Bindels, Rene J.

2009-01-01

112

IMPLICATIONS OF THE CALCIUM-ALUMINUM EXCHANGE SYSTEM FOR THE EFFECT OF ACID PRECIPITATION ON SOILS  

EPA Science Inventory

Calcium-aluminum exchange isotherms were generated for three common ion exchange equilibrium equations, and their implications relative to the probable effects of acid rainfall are examined. The equations examined were those of Gaines and Thomas (1953), Vanselow (1932), and Gapon...

113

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

114

Yeast adaptation to weak acids prevents futile energy expenditure  

PubMed Central

Weak organic acids (WOAs) are widely used preservatives to prevent fungal spoilage of foods and beverages. Exposure of baker's yeast Saccharomyces cerevisiae to WOA leads to cellular acidification and anion accumulation. Pre-adaptation of cultures reduced the rate of acidification caused by weak acid exposure, most likely as a result of changes in plasma membrane or cell wall composition. In order to adapt to sublethal concentrations of the acids and grow, yeast cells activate ATP consuming membrane transporters to remove protons and anions. We explored to what extent ATP depletion contributes to growth inhibition in sorbic or acetic acid treated cells. Therefore, we analyzed the effect of the reduction of proton and anion pumping activity on intracellular pH (pHi), growth, and energy status upon exposure to the hydrophilic acetic acid (HA) and the lipophilic sorbic acid (HS). ATP concentrations were dependent on the severity of the stress. Unexpectedly, we observed a stronger reduction of ATP with growth reducing than with growth inhibitory concentrations of both acids. We deduce that the not the ATP reduction caused by proton pumping, but rather the cost of sorbate anion pumping contributes to growth inhibition. A reduction of proton pumping activity may reduce ATP consumption, but the resulting decrease of pHi affects growth more. ATP utilization was differentially regulated during moderate and severe stress conditions. We propose that the energy depletion alone is not the cause of growth inhibition during HA or HS stress. Rather, the cells appear to reduce ATP consumption in high stress conditions, likely to prevent futile cycling and maintain energy reserves for growth resumption in more favorable conditions. The mechanism for such decision making remains to be established.

Ullah, Azmat; Chandrasekaran, Gayathri; Brul, Stanley; Smits, Gertien J.

2013-01-01

115

Bioactivity in silica/poly(?-glutamic acid) sol-gel hybrids through calcium chelation.  

PubMed

Bioactive glasses and inorganic/organic hybrids have great potential as biomedical implant materials. Sol-gel hybrids with interpenetrating networks of silica and biodegradable polymers can combine the bioactive properties of a glass with the toughness of a polymer. However, traditional calcium sources such as calcium nitrate and calcium chloride are unsuitable for hybrids. In this study calcium was incorporated by chelation to the polymer component. The calcium salt form of poly(?-glutamic acid) (?CaPGA) was synthesized for use as both a calcium source and as the biodegradable toughening component of the hybrids. Hybrids of 40wt.% ?CaPGA were successfully formed and had fine scale integration of Ca and Si ions, according to secondary ion mass spectrometry imaging, indicating a homogeneous distribution of organic and inorganic components. (29)Si magic angle spinning nuclear magnetic resonance data demonstrated that the network connectivity was unaltered with changing polymer molecular weight, as there was no perturbation to the overall Si speciation and silica network formation. Upon immersion in simulated body fluid a hydroxycarbonate apatite surface layer formed on the hybrids within 1week. The polymer molecular weight (Mw 30-120kDa) affected the mechanical properties of the resulting hybrids, but all hybrids had large strains to failure, >26%, and compressive strengths, in excess of 300MPa. The large strain to failure values showed that ?CaPGA hybrids exhibited non-brittle behaviour whilst also incorporating calcium. Thus calcium incorporation by chelation to the polymer component is justified as a novel approach in hybrids for biomedical materials. PMID:23632373

Valliant, Esther M; Romer, Frederik; Wang, Daming; McPhail, David S; Smith, Mark E; Hanna, John V; Jones, Julian R

2013-08-01

116

Recommendations for accelerating global action to prevent folic acid-preventable birth defects and other folate-deficiency diseases: Meeting of experts on preventing folic acid-preventable neural tube defects  

Microsoft Academic Search

BACKGROUND: In April of 2003, The Micronutrient Initiative, in collaboration with several other organizations, convened a group of knowledgeable scientists and policy experts to discuss ways to accelerate the global pace at which countries implement effective and sustainable programs to prevent folic acid-preventable birth defects and other folate-deficiency diseases. Programs implemented to date by fewer than 40 countries have prevented

Godfrey P. Oakley; Karen N. Bell; Mary Beth Weber

2004-01-01

117

[Long-term effect of calcium carbonate containing antacids on basally and peptone-stimulated hydrochloric acid secretion].  

PubMed

Basal and meal-stimulated gastric acid secretion was measured before and after a 3-week-period of regular consumption of a calcium carbonate-containing antacid with 6 therapeutic doses per day in normal healthy volunteers. Furthermore the effect of a single large dose of 2000 mg calcium ions was studied on meal-stimulated gastric acid secretion before and after this period. The results suggest that (1) even a large single dose of calcium ions seems to have no major effect on meal-stimulated gastric acid secretion and (2) chronic consumption of calcium carbonate containing antacids over a 3-week-period does not change basal- and meal-stimulated gastric acid secretion in healthy volunteers nor does it increase the response to 2 g calcium ions. PMID:40853

Lux, G; Waldherr, P A; Schmack, B; Rösch, W

1979-10-01

118

The influence of some amino acids on calcium oxalate dihydrate transformation  

NASA Astrophysics Data System (ADS)

The influence of histidine (His), serine (Ser), tryptophan (Trp), glutamic acid (Glu) and ornithine (Orn) on the formation of calcium oxalate hydrates and the transformation of calcium oxalate dihydrate (COD) to the thermodynamically stable monohydrate (COM) has been studied. Simultaneous production of two hydrates (COM and COD) was initiated by mixing sodium oxalate solutions containing the respective amino acid with equal volumes of calcium chloride solutions. A combination of optical microscopy, X-ray diffraction, thermogravimetric analysis, size distribution measurements and atomic absorption spectroscopy were used to characterize the processes involved. The examined amino acids have a specific effect on the nucleation of calcium oxalates: Trp and His promote the formation of COD over COM while the others favour the formation of COM. The presence of Trp and Ser influenced the morphology of COD crystals. The processes comprising the transformation, the dissolution of COD and the growth of COM, were examined separately. The corresponding growth and dissolution rates have been determined and it was found that Trp and Ser affected the transformation kinetics by changing the rate controlling mechanism of COD dissolution from diffusion to a surface controlled reaction.

Bre?evi?, Lj.; Kralj, D.

1986-12-01

119

Effects of calcium salts of acidic monomers on mineral induction of phosphoprotein immobilized to agarose beads.  

PubMed

The aim of this study is to evaluate the mineralizing potential of acidic monomers and their calcium salts for mineralization, using an in vitro mineral induction model. Phosvitin (PV) was used as a model phosphoprotein in this study. PV was immobilized on agarose beads with divinyl sulfone. Five aliquots of agarose-immobilized PV, acidic monomers, and their calcium salts were incubated in mineralizing solution at various concentrations. The PV beads and acidic monomers were incubated at 37°C. Samples were taken at several time points during the incubation. Then, the agarose beads were analyzed for bound calcium by atomic absorption spectrometry. The mineral formed on the agarose beads was identified as an apatite by microarea X-ray diffraction. Additionally, the specimens were observed using scanning electron microscopy (SEM). Mineral induction time decreased with increasing solution saturation. 4-METCa salt [calcium salt of 4-methacryloxyethyl trimellitate (CMET)] significantly reduced the mineral induction time. Using these data, the interfacial tension for mineral induction of PV and CMET was determined to be 90.1 and 92.7 ergs/cm(2), respectively. The mineral induced in each specimen after incubation for 24 h was identified by its X-ray diffraction pattern as apatite. SEM observation showed that lath-shaped crystals were formed on the surfaces of the CMET. We conclude that CMET could play a role in dentin remineralization. PMID:22623052

Ito, Shuichi; Iijima, Masahiro; Motai, Fumiko; Mizoguchi, Itaru; Saito, Takashi

2012-10-01

120

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

121

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

122

Effect of ethylenediaminetetraacetic acid (di sodium salt) and aquasoft 330 on crystal growth and morphology of calcium oxalate  

Microsoft Academic Search

Calcium oxalate was synthesized from calcium chloride solution using oxalic acid in the presence of di sodium salt of ethylenediaminetetraacetic acid (EDTA) and commercially available1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), aquasoft having chelating value 330 (AQ 330). The experiments were carried out at three different temperatures 60, 80 and 100°C. The samples were characterized using scanning electron microscope (SEM), powder X-ray diffraction analysis

P. Vijaya; Shanmukhaprasad Gopi; Aushiq H. Wani; M. V. Rajasekharan; V. K. Subramanian

123

Calcium salts for treating hypocalcemia: carrier effects, acid-base balance, and oral versus rectal administration.  

PubMed

Oral Ca salt supplements are being used to combat hypocalcemia in dairy cows. The absorption of these Ca supplements is dependent on the salt and carrier used. In the studies presented, the magnitude of the rise in plasma Ca concentration following administration of the Ca preparation was used as an index of Ca absorption by the gastrointestinal tract. Calcium chloride preparations in a water-soluble carrier (propylene glycol) were absorbed more readily than Ca propionate in propylene glycol, but Ca propionate effected a more sustained increase in plasma Ca concentration. Vegetable oil preparations of these salts were poorly absorbed. Calcium chloride preparations induced a significant decrease in blood and urine pH. Calcium propionate salts did not alter acid-base balance. Rectal administration of Ca salts could raise plasma Ca concentration rapidly, but caused serious pathological lesions, precluding their use. PMID:8046084

Goff, J P; Horst, R L

1994-05-01

124

Oxygen-regulated protein-150 prevents calcium homeostasis deregulation and apoptosis induced by oxidized LDL in vascular cells.  

PubMed

Oxidized LDLs (oxLDLs) induce apoptosis, which contributes to the pathogenesis of atherosclerosis. The 150 kDa oxygen-regulated protein (ORP150), an endoplasmic reticulum (ER)-resident chaperone, is upregulated by hypoxia and prevents ischemia-induced cell death. The aim of this work was to investigate whether and how ORP150 can prevent apoptosis induced by oxLDLs in vascular cells. OxLDLs induced ORP150 expression in the ER of human microvascular endothelial cell line (HMEC-1). ORP150 expression was blocked by antioxidants, by the permeant calcium chelator BAPTA-AM, and by inhibitors of the inositol-1,4,5 trisphosphate (IP3) receptors, 2-aminoethyl diphenylborinate (2-APB) and xestospongin C. ORP150 silencing by siRNA-enhanced oxLDL-induced apoptosis, while forced ORP150 expression increased the resistance of cells via an inhibition of the oxLDL-induced calcium rise, and of subsequent calpain activation, cytochrome c release, caspase 3 activation and apoptosis. A similar protective effect was achieved by BAPTA-AM, 2-APB and xestospongin C. Altogether, these data indicate that (i)ORP150 inhibits oxLDL-induced apoptosis by blocking calcium signaling and subsequent apoptosis, (ii)calcium released from ER stores through IP3 channels is involved in the oxLDL-induced calcium rise and apoptosis, and is inhibited by ORP150. Finally, ORP150 is expressed in advanced atherosclerotic lesions, where it may locally participate to reduce the apoptotic effect of oxLDLs and the subsequent risk of plaque rupture. PMID:18404158

Sanson, M; Ingueneau, C; Vindis, C; Thiers, J-C; Glock, Y; Rousseau, H; Sawa, Y; Bando, Y; Mallat, Z; Salvayre, R; Nègre-Salvayre, A

2008-08-01

125

Endurance exercise training normalizes repolarization and calcium-handling abnormalities, preventing ventricular fibrillation in a model of sudden cardiac death  

PubMed Central

The risk of sudden cardiac death is increased following myocardial infarction. Exercise training reduces arrhythmia susceptibility, but the mechanism is unknown. We used a canine model of sudden cardiac death (healed infarction, with ventricular tachyarrhythmias induced by an exercise plus ischemia test, VF+); we previously reported that endurance exercise training was antiarrhythmic in this model (Billman GE. Am J Physiol Heart Circ Physiol 297: H1171–H1193, 2009). A total of 41 VF+ animals were studied, after random assignment to 10 wk of endurance exercise training (EET; n = 21) or a matched sedentary period (n = 20). Following (>1 wk) the final attempted arrhythmia induction, isolated myocytes were used to test the hypotheses that the endurance exercise-induced antiarrhythmic effects resulted from normalization of cellular electrophysiology and/or normalization of calcium handling. EET prevented VF and shortened in vivo repolarization (P < 0.05). EET normalized action potential duration and variability compared with the sedentary group. EET resulted in a further decrement in transient outward current compared with the sedentary VF+ group (P < 0.05). Sedentary VF+ dogs had a significant reduction in repolarizing K+ current, which was restored by exercise training (P < 0.05). Compared with controls, myocytes from the sedentary VF+ group displayed calcium alternans, increased calcium spark frequency, and increased phosphorylation of S2814 on ryanodine receptor 2. These abnormalities in intracellular calcium handling were attenuated by exercise training (P < 0.05). Exercise training prevented ischemically induced VF, in association with a combination of beneficial effects on cellular electrophysiology and calcium handling.

Bonilla, Ingrid M.; Belevych, Andriy E.; Sridhar, Arun; Nishijima, Yoshinori; Ho, Hsiang-Ting; He, Quanhua; Kukielka, Monica; Terentyev, Dmitry; Terentyeva, Radmila; Liu, Bin; Long, Victor P.; Gyorke, Sandor; Billman, George E.

2012-01-01

126

Method for preventing the precipitation of ferric compounds during the acid treatment of wells  

SciTech Connect

A method is described for preventing the undesirable formation and precipitation of ferric compounds from a spent threatment acid containing dissolved iron following an acidizing treatment of subterranean formations surrounding a wellbore. The method consists of adding to the treatment acid prior to contact with the formation an amount of ascorbic acid and/or erythorbic acid, and/or a soluble salt of the acid, sufficient to prevent the formation and precipitation of ferric compounds from the treatment acid upon spending.

Crowe, C.W.; Maddin, C.M.

1986-03-04

127

Calcium-binding protein of bovine intestine. The complete amino acid sequence.  

PubMed

The amino acid sequence for vitamin D-dependent bovine intestinal calcium binding protein has been established. It contains 85 amino acids in a single chain and lacks cysteine, tryptophan, methionine, histidine, and arginine. The NH2-terminal lysine is blocked by an N-acetyl group. Enzymatic digestion with trypsin, chymotrypsin, and pepsin yielded a number of peptides which were purified by two-dimensional high voltage paper electrophoresis. These peptides were examined by end group analysis and sequenced by the dansyl procedure. The absence of tryptophan permitted by a single cleavage of the molecule by N-bromosuccinimide at the tyrosine residue at position 8 and the larger fragment was subjected to automated Edman degradation. By these means, the following sequence was established: N-Ac-Lys-Gln-Ser-Pro-Leu-Glu-Tyr-Ala-Ala-Glu-Lys-Ser-Ile-Gln-Lys-Glu-Ile-Glu-Lys-Gly-Phe-Phe-Lys-Gln-Leu-Leu-Val-Ser-Val-Gln-Lys-Ala-Gly-Asp-Lys-Glu-Ser-Leu-Gln-Pro-Leu-Phe-Thr-Leu-Leu-Lys-Ser-Gly-Pro-Glu-Glu-Asn-Leu-Lys-Glu-Ser-Gln-Asn-Gly-Pro-Asp-Leu-Ls7-Ser-Gly-Pro-Gly-Asn-Asp-Leu-Glu-Glu-Lys-Gly-Thr-Asp-Val-Phe-Ser-Leu-Lys-Gln. Microheterogeneity may exist in the molecule at residue 76 in which position threonine may be replaced by serine. Comparison of the sequence of calcium-binding protein to the "test" sequence of Tufty and Kretsinger ((1975) Science 187, 167-169) proposed to identify E-F hands in muscle proteins suggests that intestinal calcium-binding protein may likewise contain one or possibly two E-F hands which could account for calcium-binding property. Dayhoff alignment scores, however, calculated for calcium-binding protein against nine E-F hands in muscle proteins parvalbumin, troponin and alkali light chains do not indicate that intestinal calcium-binding protein is homologous to these muscle protein chains. PMID:1176441

Huang, W Y; Cohn, D V; Hamilton, J W; Fullmer, C; Wasserman, R H

1975-10-10

128

Acidic NAADP-sensitive Calcium Stores in the Endothelium  

PubMed Central

Accumulating evidence implicates nicotinic acid adenine dinucleotide phosphate (NAADP) in the control of Ca2+-dependent functions. Little, however, is known concerning its role in the vascular endothelium, a major regulator of blood pressure. Here, we show that NAADP acetoxymethyl ester (NAADP-AM), a cell-permeant NAADP analog, increases cytosolic Ca2+ concentration in aortic endothelial cells. We demonstrate that these signals and those evoked by acetylcholine are blocked by disrupting acidic organelles with bafilomycin A1. In contrast, Ca2+ signals in response to thrombin are only partially inhibited by bafilomycin A1 treatment, and those to ATP were insensitive, suggesting that recruitment of acidic stores is agonist-specific. We further show that NAADP-evoked Ca2+ signals hyperpolarize endothelial cells and generate NO. Additionally, we demonstrate that NAADP dilates aortic rings in an endothelium- and NO-dependent manner. Finally, we show that intravenous administration of NAADP-AM into anesthetized rats decreases mean arterial pressure. Our data extend the actions of NAADP to the endothelium both in vitro and in vivo, pointing to a previously unrecognized role for this messenger in controlling blood pressure.

Brailoiu, G. Cristina; Gurzu, Bogdan; Gao, Xin; Parkesh, Raman; Aley, Parvinder K.; Trifa, Diana I.; Galione, Antony; Dun, Nae J.; Madesh, Muniswamy; Patel, Sandip; Churchill, Grant C.; Brailoiu, Eugen

2010-01-01

129

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

130

The activity of ferulic and gallic acids in biofilm prevention and control of pathogenic bacteria  

Microsoft Academic Search

The activity of two phenolic acids, gallic acid (GA) and ferulic acid (FA) at 1000 ?g ml, was evaluated on the prevention and control of biofilms formed by Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. In addition, the effect of the two phenolic acids was tested on planktonic cell susceptibility, bacterial motility and adhesion. Biofilm prevention and control

Anabela Borges; Maria J. Saavedra; Manuel Simões

2012-01-01

131

[Calcium antagonists: current and future applications based on new evidence. The mechanisms on lowering serum uric acid level by calcium channel blockers].  

PubMed

In hypertensive subjects, their serum uric acid levels tend to be higher because of decreasing urinary secretion or overproduction of uric acid. Among calcium channel blockers (CCBs) , long acting nifedipine and cilnidipine reveal serum uric acid lowering action. They decrease the production of uric acid precursor in skeletal muscles under anaerobic condition induced by hypertension or insulin resistance. Hyperuricemia is considered to be a risk factor of not only gout but also renal and cardiovascular diseases, thus, it is important to use CCBs without adverse effect on uric acid metabolisms. PMID:20048433

Mizuta, Einosuke; Hamada, Toshihiro; Igawa, Osamu; Shigemasa, Chiaki; Hisatome, Ichiro

2010-01-01

132

Preparation of poly(lactic acid)\\/siloxane\\/calcium carbonate composite membranes with antibacterial activity  

Microsoft Academic Search

A poly(lactic acid) (PLA)\\/siloxane\\/calcium carbonate composite membrane containing mercapto groups (PSC-SH) with antibacterial ability and excellent bone-forming ability was prepared using 3-mercaptopropyltrimethoxysilane for application in guided bone regeneration. Mercapto groups were reported to adsorb silver ions, which are well known to show antibacterial activity. Ionic silicon species were reported to stimulate the proliferation of osteoblasts. A PSC-SH membrane with a

Shingo Tokuda; Akiko Obata; Toshihiro Kasuga

2009-01-01

133

Effects of calcium soaps of fatty acids on postpartum reproductive function in beef  

Microsoft Academic Search

ABSTRACT Twelve multiparous Simmental cows (584 kg) were used to determine the influence of calcium soaps of fatty acids (CSFA) incorporated in a range supplement on postpartum reproductive characteristics. Cows were assigned randomly,to receive a control [C; containin grain sorghum,(GS) and soybean meal (SBM)] or CSFA-based (containing were individually , fed CSFA although plasma triglyceride concentrations were similar between treatments.

R. B. Hightshoe; R. C. Cochran; L. R. Corah; G. H. Kiracofe; D. L. Harmon; R. C. Perry

134

Interaction between dietary conjugated linoleic acid and calcium supplementation affecting bone and fat mass  

Microsoft Academic Search

Dietary conjugated linoleic acid (CLA) has shown wide biologically beneficial effects, such as anticancer, antiatherosclerotic,\\u000a antidiabetic, immunomodulating, and antiobesity effects. However, the effects of CLA on total body ash, reflective of bone\\u000a mineral content, have not been consistent. We hypothesized that the inconsistency of the CLA effect on ash may be linked to\\u000a interaction between CLA and dietary calcium levels.

Yooheon ParkMichael; Michael Terk

2011-01-01

135

Roles of microbial acidic polysaccharides in precipitation rate and polymorph of calcium carbonate minerals  

Microsoft Academic Search

Organic molecules secreted by bacterial cells are capable of influencing dissolution and precipitation rates of various minerals including calcium carbonate (CaCO3) minerals. To evaluate the effects of polysaccharides on the precipitation rates and polymorph of CaCO3 minerals, precipitation experiments were performed in systems containing alginic acid or gellan gum by the batch method using 100ml solution at 25°C. Each solution

Motoharu Kawano; Jinyeon Hwang

2011-01-01

136

Synthesis, characterization and cation adsorption of p-aminobenzoic acid intercalated on calcium phosphate  

SciTech Connect

Graphical abstract: Scanning electron microscopy photographs of calcium phosphate (a) and intercalated with p-aminobenzoic acid (b). Highlights: ? Calcium phosphate was intercalated with p-aminobenzoic acid. ? Guest molecule contains nitrogen and oxygen atoms from amine and carboxylic groups. ? These basic centers are potentially useful for cation coordination in ethanol solution. ? Crystal morphology of compounds is lamellar, it agrees with expected structural characteristics. -- Abstract: Crystalline lamellar calcium phosphate retained 4-aminobenzoic acid inside its cavity without leaching. The intense infrared bands in the 1033 and 1010 cm{sup ?1} interval confirmed the presence of the phosphonate groups attached to the inorganic layer, with sharp and intense peaks in X-ray diffraction patterns, which gave basal distances of 712 and 1578 pm for the original and the intercalated compounds, respectively. Solid-state {sup 31}P nuclear magnetic resonance spectra presented only one peak for the phosphate groups attached to the main inorganic polymeric structure near ?2.4 ppm. The adsorption isotherms from ethanol gave the maximum adsorption capacities of 6.44 and 3.34 mmol g{sup ?1} for nickel and cobalt, respectively, which stability constant and distribution coefficient followed Co > Ni.

Silva, Camila F.N. [Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR (Brazil)] [Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR (Brazil); Lazarin, Angélica M., E-mail: amlazarin2@uem.br [Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR (Brazil); Sernaglia, Rosana L.; Andreotti, Elza I.S. [Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR (Brazil)] [Departamento de Química, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR (Brazil)

2012-06-15

137

Fabrication and characterization of poly(lactic-co-glycolic acid) microsphere/amorphous calcium phosphate scaffolds.  

PubMed

Although hydroxyapatite (HAP) and ?-tricalcium phosphate have been used extensively as osteoconductive minerals in biomaterial scaffolds for bone regeneration, they lack the capacity to stimulate osteoblastic differentiation of progenitor cells. In contrast, amorphous calcium phosphates (ACPs), which convert to HAP under aqueous conditions, have the potential to facilitate osteoblastic differentiation through the transient local release of calcium and phosphate ions. Therefore, in this study ACPs were synthesized using zinc and zirconia divalent cations as stabilizers (denoted ZnACP and ZrACP, respectively) and compared to HAP. Analysis of ion release into serum-containing cell culture medium revealed transiently elevated levels of calcium and phosphorous, consistent with the enhanced solubility of ZrACP and ZnACP relative to HAP. In addition, X-ray diffraction analysis revealed partial conversion of ZrACP to HAP but no conversion of ZnACP after 96 h. Next, scaffolds were fabricated by sintering mixtures of 300-500 µm poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres and 0.5 wt% calcium phosphate mineral (HAP, ZrACP or ZnACP) at 70 °C for 24 h. Scanning electron microscopy revealed a porous microsphere matrix with calcium phosphate particulates clinging to the microsphere surfaces both prior to and after 14 days in culture medium. Finally, the incorporation of calcium phosphate resulted in a lower compressive modulus in the range 127 to 74-89 MPa. Taken together, these results indicate that ZrACP, ZnACP and HAP minerals exhibit very different properties, and therefore may elicit different osteoblastic responses in vitro. PMID:21312335

Popp, Jenni R; Laflin, Kate E; Love, Brian J; Goldstein, Aaron S

2012-01-01

138

Effect of polyacrylic acid and polyethylene glycol on the crystallization of calcium carbonates in the presence of magnesium ions  

Microsoft Academic Search

The effect of polyacrylic acid and polyethylene glycol on the crystallization of calcium carbonates in the presence of magnesium\\u000a ions was studied. It was found that the presence of magnesium ions in solution and the treatment temperature (80°C) influence\\u000a the formation of the final products of calcium carbonate crystallization. In binary mixtures, low-molecular-weight polyacrylic\\u000a acid and polyethylene glycol affect synergistically,

I. V. Shestak; P. D. Vorob’ev; D. V. Cherednichenko; E. V. Vorob’eva; G. V. Bondareva; N. Strnadova

2011-01-01

139

The role of lipoic acid in prevention of nitroglycerin tolerance.  

PubMed

Besides other organic nitrates, nitroglycerin (glyceryl trinitrate; GTN) has been used to treat acute heart failure particularly due to ischemic heart disease. However, one of serious clinical problems of the GTN therapy, particularly a long-standing medication, is hemodynamic tolerance to GTN, manifested by the decreased therapeutic efficacy of the drug. The most recent studies have suggested that mitochondrial lipoate/dihydrolipoate system-dependent aldehyde dehydrogenase-2 plays a key role in nitric oxide release from GTN. The aldehyde dehydrogenase-2 performs three enzymatic activities of dehydrogenase, esterase and reductase. The reductase activity is responsible for bioactivation of organic nitrates, such as GTN yielding nitrite and dinitrate (1,2-GDN/1,3-GDN, approximately 8:1). In view of a large contribution of dihydrolipoic acid to stabilization and regeneration of thiol groups, necessary for the reductase activity of aldehyde dehydrogenase-2, we conducted studies aimed to determine whether lipoic acid administration to rats is able to prevent GTN tolerance. The studies were conducted on 4 groups of animals: control saline-treated, model GTN-tolerant, GTN + lipoic acid-treated, lipoic acid alone-administered groups. On the 9th day of experiment animals were given i.v. therapeutic dose of GTN. We measured in all animals systolic and diastolic blood pressure before injection of therapeutic dose of GTN into the cadual vein and during 20 min thereafter. Levels of nitric oxide and reactive oxygen species and activities of glutathione peroxidase and superoxide dismutase were assayed in the aorta, plasma and heart of all animals. In addition, levels of malondialdehyde, and non-protein thiols, and activities of glutathione S-transferase and gamma-glutamyl transpeptidase were evaluated in the heart and plasma. The obtained results indicate that treatment of rats with a combination of lipoic acid and GTN can efficiently counteract GTN tolerance. PMID:18616939

Dudek, Magdalena; Bednarski, Marek; Bilska, Anna; Iciek, Ma?gorzata; Soko?owska-Jezewicz, Maria; Filipek, Barbara; W?odek, Lidia

2008-09-01

140

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.

May, James M.; Qu, Zhi-chao

2013-01-01

141

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

142

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

PubMed Central

Pseudoxanthoma elasticum (PXE) is a heritable disorder characterized by ectopic calcification of connective tissue in skin, 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 clinical symptoms, the patient organization PXE International has published the dietary advice to increase calcium intake in combination with increased magnesium intake. To obtain more data on this controversial issue, we examined the effect of dietary calcium and magnesium in the Abcc6?/? mouse, a PXE mouse model which mimics the clinical features of PXE. Abcc6?/? mice were placed on specific diets for 3, 7, and 12 months. Disease severity was measured by quantifying calcification of blood vessels in the kidney. Raising the calcium content in the diet from 0.5% to 2% did not change disease severity. In contrast, simultaneous increase of both calcium (from 0.5% to 2.0%) and magnesium (from 0.05% to 0.2%) slowed down the calcification significantly. Our present findings that increase in dietary magnesium reduces vascular calcification in a mouse model for PXE should stimulate further studies to establish a dietary intervention for PXE.

Waarsing, Jan H.; de Wolf, Anneke; ten Brink, Jacoline B.; Loves, Willem J. P.; Bergen, Arthur A. B.

2010-01-01

143

In-Situ Cold Temperature XRD of Calcium Phosphate Produced From Organic Phosphoric Acid  

NASA Astrophysics Data System (ADS)

In this study, we synthesized calcium phosphate from an organic phosphoric acid, diethylhexyl phosphoric acid (DEHPA) and calcium hydroxide solution. The reaction involves a sol-gel process with a whitish gel formed. In-situ XRD analysis was then performed on the sample from room temperature to -140° C. At room the XRD diffractogram shows the sample as an amorphous material and as the temperature was further lowered sharp peaks begins to form indicating that the material had becomes crystalline. The peaks were identified to be that calcium hydrogen phosphate (Ca(H2PO4)2) and this indicates that there is no hydroxyl group removal during the cooling process. The relative crystallinity values obtained for the different cooling temperatures show a slow exponential increase on the initial cooling of 0 to -100° C and at further cooling temperatures resulted fast and linear process. Also unlike the in-situ XRD analysis performs at high temperature no phase transformation occurred at this low temperature.

Yusoff, M. S. Meor; Paulus, Wilfred; Muslimin, Masliana

2010-01-01

144

Composite scaffolds of nano calcium deficient hydroxyapatite/multi-(amino acid) copolymer for bone tissue regeneration.  

PubMed

In this study, nano calcium deficient hydroxyapatite (n-DA)/multi-(amino acid) copolymer composite scaffolds were prepared by injection molding foaming method using calcium sulphate dihydrate as a foaming agent. The composite scaffolds showed well interconnected macropores with the pore size of ranging from 100 to 600 ?m, porosity of 81 % and compressive strength of 12 MPa, and the compressive strength obviously affected by the porosity. The composite scaffolds could be slowly degraded in phosphate buffered solution (PBS), which lost its initial weight of 61 w % after immersion into PBS for 12 weeks, and the porosity significantly affected the degradability of the scaffolds. Moreover, it was found that the composite scaffolds could promote the MG-63 cells growth and proliferation, and enhance its alkaline phosphatase activity. The implantation of the scaffolds into the femoral bone of rabbits confirmed that the composite scaffolds were biocompatibitive, degradable, and osteoconductive in vivo. PMID:24488438

Li, Hong; Yang, Lili; Dong, Xieping; Gu, Yifei; Lv, Guoyu; Yan, Yonggang

2014-05-01

145

Methylene blue intercalated into calcium phosphate - Electrochemical properties and an ascorbic acid oxidation study  

NASA Astrophysics Data System (ADS)

Methylene blue (MB) was intercalated inside the cavity of a layered calcium phosphate host. The dye is strongly retained and not easily leached from the matrix. The intercalated dye material was incorporated into a carbon paste electrode and by means of cyclic voltammetry and amperometry, its electrochemical properties were investigated. In various electrolyte solutions, on changing the pH between 3 and 9, the midpoint potential remained practically constant at -0.15 V. This is not the usual behavior for MB, since it is known that in the solution phase the midpoint potential changes considerably with pH, indicating that, in the present case, methylene blue is a guest molecule intercalated inside the lamellar structure of the calcium phosphate. An electrode made with this material was used to study the electrochemical oxidation of ascorbic acid and then applied to commercial samples, with excellent agreement within the 95% confidence level.

Lazarin, Angélica M.; Airoldi, Claudio

2008-09-01

146

Prevention of falls and fractures in old people by administration of calcium and vitamin d. randomized clinical trial  

PubMed Central

Background There are many studies that associate vitamin D serum levels in older persons with muscle strength, physical performance and risk of fractures and falls. However, current evidence is insufficient to make a general recommendation for administrating calcium and vitamin D to older persons. The objective of this study is to determine the effectiveness of calcium and vitamin D supplementation in improving musculoskeletal function and decreasing the number of falls in person aged over 65 years. Methods/Design Phase III, randomized, double blind, placebo-controlled trial to evaluate the efficacy of already marketed drugs in a new indication. It will be performed at Primary Care doctor visits at several Healthcare Centers in different Spanish Health Areas. A total of 704 non-institutionalized subjects aged 65 years or older will be studied (sample size calculated for a statistical power of 80%, alpha error 0.05, annual incidence of falls 30% and expected reduction of 30% to 20% and expected loss to follow up of 20%). The test drug containing 800 IU of vitamin D and 1000 mg of calcium will be administered daily. The control group will receive a placebo. The subjects will be followed up over two years. The primary variable will be the incidence of spontaneous falls. The secondary variables will include: consequences of the falls (fractures, need for hospitalization), change in calcidiol plasma levels and other analytical determinations (transaminases, PTH, calcium/phosphorous, albumin, creatinine, etc.), change in bone mass by densitometry, change in muscle strength in the dominant hand and change in musculoskeletal strength, risk factors for falls, treatment compliance, adverse effects and socio-demographic data. Discussion The following principles have been considered in the development of this Project: the product data are sufficient to ensure that the risks assumed by the study participants are acceptable, the study objectives will probably provide further knowledge on the problem studied and the available information justifies the performance of the study and its possible risk for the participants. If calcium and vitamin D supplementation is effective in the prevention of falls and fractures in the elderly population, a recommendation may be issued with the aim of preventing some of the consequences of falls that affect quality of life and the ensuing personal, health and social costs. Trial Registration ClinicalTrials.gov: NCT01452243 Clinical trial authorized by the Spanish Medicines Agency: EudraCT number 2006-001643-63.

2011-01-01

147

Atherosclerosis and hypertension induction by lead and cadmium ions: an effect prevented by calcium ion  

SciTech Connect

In epidemiological studies, both positive and negative correlations have been found between cardiovascular disease and mortality and the presence of several inorganic ions in the drinking water. In an attempt to resolve this apparent disagreement, we exposed White Carneau pigeons to drinking water containing calcium (100 ppm), magnesium (30 ppm), lead (0.8 ppm), or cadmium (0.6 ppm) and used a 2/sup 4/-factorial design to measure the effects of these elements in atherosclerosis and hypertension. The results indicate that (i) lead and cadmium induced aortic atherosclerosis and hypertension, and (ii) calcium protects against the cardiovascular effects of cadmium. Furthermore, the effects were indications that magnesium antagonized the atherosclerotic protective effect of calcium. We suggest that, if these results with the pigeon can be applied to humans, the incidence of aortic atherosclerosis and hypertension should be significantly higher in areas where the drinking water contains magnesium, lead, and cadmium with a relatively low calcium concentration. Furthermore, if hard and soft water produce similar levels of lead and cadmium uptakes, the level of magnesium may be an additional factor in aortic atherosclerosis.

Revis, N.W. (Oak Ridge National Lab., TN); Zinsmeistery, A.R.; Bull, R.

1981-10-01

148

Inhibiting Gastric Acid Production Does Not Affect Intestinal Calcium Absorption in Young, Healthy Individuals: A Randomized, Crossover, Controlled Clinical Trial  

PubMed Central

Proton pump inhibitors (PPIs) are the most potent gastric acid suppressing drugs available, and their use is widespread. An emerging concern about chronic PPI therapy is whether these drugs impair intestinal calcium absorption, resulting in a negative calcium balance and thereby potentially causing bone loss. The objective of this study was to evaluate the acute effect of the PPI esomeprazole or placebo on intestinal calcium absorption in healthy adults. Twelve young adults participated in a placebo-controlled, double-blind, crossover study. There were two 3-week interventions that included a 14-day adjustment period (designed to stabilize calcium homeostasis) followed by 6 days of a diet containing 800 mg of calcium and 2.1 g/kg of protein (intervention). During the last 3 days of the adjustment period and throughout the intervention period, subjects consumed esomeprazole or placebo. Half the subjects underwent 24-hour continuous gastric acid pH monitoring. Intestinal calcium absorption was measured using dual-stable calcium isotopes at the end of each intervention. Treatment with esomprazole significantly increased gastric pH (mean pH on PPI 5.38 ± 0.13, mean pH on placebo 2.70 ± 0.44, p =.005). Neither calcium absorption (PPI 34.2% ± 2.4%, placebo 31.5% ± 2.1%, p =.24) nor urinary calcium (PPI 321 ± 38 mg/34 hours, placebo 355 ± 37 mg/34 hours, p =.07) differed between the PPI and placebo groups. It is concluded that short-term gastric acid suppression by PPIs does not attenuate intestinal calcium absorption in healthy young adults.

Wright, Matthew J; Sullivan, Rebecca R; Gaffney-Stomberg, Erin; Caseria, Donna M; O'Brien, Kimberly O; Proctor, Deborah D; Simpson, Christine A; Kerstetter, Jane E; Insogna, Karl L

2010-01-01

149

Strontium ranelate prevents the deleterious action of advanced glycation endproducts on osteoblastic cells via calcium channel activation.  

PubMed

Accumulation of advanced glycation endproducts (AGEs) in bone tissue occurs in ageing and in Diabetes mellitus, and is partly responsible for the increased risk of low-stress bone fractures observed in these conditions. In this study we evaluated whether the anti-osteoporotic agent strontium ranelate can prevent the deleterious effects of AGEs on bone cells, and possible mechanisms of action involved. Using mouse MC3T3E1 osteoblastic cells in culture we evaluated the effects of 0.1mM strontium ranelate and/or 100 ?g/ml AGEs-modified bovine serum albumin (AGEs-BSA) on cell proliferation, osteogenic differentiation and pro-inflammatory cytokine production. We found that AGEs-BSA alone decreased osteoblastic proliferation and differentiation (P<0.01) while increasing IL-1? and TNF? production (P<0.01). On its own, strontium ranelate induced opposite effects: an increase in osteoblast proliferation and differentiation (P<0.01) and a decrease in cytokine secretion (P<0.01). Additionally, strontium ranelate prevented the inhibitory and pro-inflammatory actions of AGEs-BSA on osteoblastic cells (P<0.01). These effects of strontium ranelate were blocked by co-incubation with either the MAPK inhibitor PD98059, or the calcium channel blocker nifedipine. We also evaluated by Western blotting the activation status of ERK (a MAPK) and b-catenin. Activation of both signaling pathways was decreased by AGEs treatment, and this inhibitory effect was prevented if AGEs were co-incubated with strontium ranelate (P<0.01). On its own, strontium ranelate increased both pERK and activated b-catenin levels. In conclusion, this study demonstrates that strontium ranelate can prevent the deleterious in vitro actions of AGEs on osteoblastic cells in culture by mechanisms that involve calcium channel, MAPK and b-catenin activation. PMID:23499695

Fernández, Juan Manuel; Molinuevo, María Silvina; Sedlinsky, Claudia; Schurman, León; Cortizo, Ana María; McCarthy, Antonio Desmond

2013-04-15

150

L-type calcium channel inhibitor diltiazem prevents aneurysm formation by blood pressure-independent anti-inflammatory effects.  

PubMed

Formation of abdominal aortic aneurysms is a progressive inflammatory process that involves infiltration and differentiation of monocytes in the vessel wall, proliferation and migration of smooth muscle cells, and eventually the degradation of the internal elastic lamina, which leads to outward vascular remodeling and distension of the vessel. Because calcium channel blockers exert multiple beneficial effects on the vascular system, we investigated the effect of the benzothiazepine-type calcium channel blocker diltiazem on aneurysm formation in a mouse model. Angiotensin II infusion induced massive suprarenal aortic aneurysm formation in male apolipoprotein E-deficient mice that was blocked by cotreatment with diltiazem even if the blood pressure was controlled by coinfusion of phenylephrine. Diltiazem prevented the angiotensin II-mediated induction of proinflammatory cytokines after 7 days of angiotensin II treatment in the aortic arch attributable to a reduction in the amount of locally infiltrating macrophages. To identify the underlying mechanism, vascular segments and cultured vascular cells as well as monocytes were studied. Diltiazem failed to reduce the angiotensin II-induced expression of proinflammatory chemokines and cytokines in isolated mouse thoracic aortic segments in organ culture. Furthermore, diltiazem did not affect the recruitment of proinflammatory Ly6C(+) monocytes in vivo pointing toward an effect of the compound on gene expression in monocytes/macrophages. Indeed, diltiazem prevented the interleukin-6-induced mRNA expression of interleukin-1? and the monocyte chemoattractant protein CCL12 in peritoneal macrophages and RAW264.7 cells independent of the intracellular calcium concentration. Thus, diltiazem limits aortic aneurysm formation in mice by a blood pressure-independent anti-inflammatory effect on monocytic cells. PMID:24082061

Mieth, Anja; Revermann, Marc; Babelova, Andrea; Weigert, Andreas; Schermuly, Ralph T; Brandes, Ralf P

2013-12-01

151

Effects of calcium salts of fatty acids and calcium salt of methionine hydroxy analogue on plasma prostaglandin F 2? metabolite and milk fatty acid profiles in late lactation Holstein–Friesian cows  

Microsoft Academic Search

Effects of a dietary lipid supplement containing calcium salts of fatty acids and methionine hydroxy analogue on plasma prostaglandin F2? (PGF2?) metabolite (PGFM) and milk fatty acid profiles were examined in 40 late lactation, nonpregnant, Holstein–Friesian cows for a period of 70 days. Effects on milk production, milk composition, and blood metabolites were also examined. Cows were paired on the

J Fahey; J. F Mee; J. J Murphy; D O’Callaghan

2002-01-01

152

Aspirin potentiates prestimulated acid secretion and mobilizes intracellular calcium in rabbit parietal cells.  

PubMed Central

The effects of aspirin on gastric acid secretion were studied in isolated rabbit parietal cells (PC). Aspirin (10(-5) M) potentiated histamine-, dibutyryl cyclic AMP (dbcAMP)-, forskolin- and 3-isobutyl-1-methylxanthine-stimulated acid secretion without affecting basal acid secretion. Augmentation of secretagogue-stimulated acid secretion by aspirin was dependent on calcium (Ca2+) since potentiation was blocked by removal of extracellular Ca2+ ([Ca2+]o) or addition of the calcium antagonist lanthanum chloride. Using the Ca2+ probe fura-2, aspirin (10(-6) - 2 X 10(-5) M) rapidly increased intracellular free Ca2+ concentration ([Ca2+]i) in a dose-dependent manner. The source of released Ca2+ was intracellular as demonstrated by depletion of intracellular Ca2+ and [Ca2+]o with EGTA washing. Aspirin did not affect several other signal transduction sites involved in stimulus-secretion coupling, including the H2 receptor, intracellular cyclic AMP (cAMP), inositol 1,4,5, triphosphate (IP3) and H+,K(+)-ATPase. Aspirin decreased PC prostaglandin E2 (PGE2) content by 98%. Exogenous dimethyl PGE2 (dmPGE2) inhibited both histamine-stimulated acid secretion and its enhancement by aspirin. In contrast, dmPGE2 abolished aspirin-induced potentiation of dbcAMP-stimulated acid secretion by augmenting the dbcAMP-stimulated response. These results indicate that aspirin acts at a site beyond the adenylate cyclase/cAMP system and before the proton pump, presumably by releasing Ca2+ from an IP3-independent intracellular storage pool and by inhibiting PGE2 generation. Images

Levine, R A; Nandi, J; King, R L

1990-01-01

153

Prevention of Posttransplant Acute Tubular Necrosis by the Calcium Antagonist Diltiazem: A Prospective Randomized Study  

Microsoft Academic Search

In a prospective randomized trial we evaluated the influence of the calcium antagonist diltiazem (Dil) on the development of acute tubular necrosis (ATN) in cadaveric kidney transplantation. Dil was added to Euro-collin’s solution (20 mg\\/l) at donor nephrectomy. The graft recipient received a preoperative bolus injection of Dil (0.28 mg\\/kg) which was followed by an infusion of Dil (0.0022 mg\\/min\\/kg)

Karl Wagner; Stefan Albrecht; Hans-Hellmut Neumayer

1987-01-01

154

Serum prevents glutamate-induced mitochondrial calcium accumulation in primary neuronal cultures  

Microsoft Academic Search

The effect of serum proteins on glutamate-induced mitochondrial calcium accumulation was studied in primary cortical and\\u000a hippocampal cultures using oxalate-pyroantimonate staining with electron microscopy. Cultures were prepared from rat embryos\\u000a on gestational day 17–19 and cultivated for 8 days in minimal essential medium (MEM) containing 5% native horse serum. At\\u000a this time cultures were exposed for 5 min to 100

E. Dux; U. Oschlies; A. Uto; M. Kusumoto; L. Siklos; F. Joo; K.-A. Hossmann

1996-01-01

155

DELIQUESCENCE BEHAVIOR AND CHEMICAL STABILITY OF VITAMIN C FORMS (ASCORBIC ACID, SODIUM ASCORBATE, AND CALCIUM ASCORBATE) AND BLENDS  

Microsoft Academic Search

The stability and type of vitamin C added to foods is important for enhancing product quality, label claims, and shelf-life. To improve understanding of stability, the effects of deliquescence, storage RH, formulation, and addition of ascorbyl palmitate and dehydroascorbic acid on degradation of vitamin C at 25°C were studied. Individual vitamin C forms (ascorbic acid, sodium and calcium ascorbate) and

Ashley N. Hiatt; Mario G. Ferruzzi; Lynne S. Taylor; Lisa J. Mauer

2010-01-01

156

In vitro biocompatibility of chitosan/hyaluronic acid-containing calcium phosphate bone cements.  

PubMed

The need for bone repair has increased as the population ages. In this research, calcium phosphate cements, with and without chitosan (CS) and hyaluronic acid (HA), were synthesized. The composition and morphological properties of cements were evaluated by X-ray diffraction and scanning electron microscopy. The acellular in vitro bioactivity revealed that different apatite morphologies were formed on the surfaces of cements after soaking in simulated body fluid. The in vitro osteoblastic cell biocompatibility of in situ forming cements was evaluated and compared with those of conventional calcium phosphate cements (CPCs). The viability and growth rate of the cells were similar for all CPCs, but better alkaline phosphatase activity was observed for CPC with CS and HA. Calcium phosphate cements supported attachment of osteoblastic cells on their surfaces. Spindle-shaped osteoblasts with developed cytoplasmic membrane were found on the surfaces of cement samples after 7 days of culture. These results reveal the potential of the CPC-CS/HA composites to be used in bone tissue engineering. PMID:24399509

Hesaraki, Saeed; Nezafati, Nader

2014-08-01

157

Dairy products, dietary calcium and bone health: possibility of prevention of osteoporosis in women: the Polish experience.  

PubMed

The objective of the study was to analyze the consumption of dairy products and dietary calcium by women in the context of bone mineral density and to assess opportunities to prevent osteoporosis in a dietary manner. The study was carried out with 712 Polish women. In 170 women aged 32 to 59 bone mineral density (BMD) was measured. The data on the consumption of dairy products and dietary calcium and some other osteoporosis risk factors was collected from 712 women. The average calcium intake from a diet was 507 mg/day. Only 2% of the women met Polish calcium intake recommendations. During adulthood, dairy product consumption or dietary calcium intake did not differ significantly between women with low BMD (below -1 SD) and women with regular BMD (?-1 SD) (47.4 vs. 44.3 servings/week and 459 vs. 510 mg/day, respectively, p > 0.05). The odds ratios adjusted for age, menstruation and BMI in women with upper BMD tercile in comparison to the reference group (bottom tercile) was 2.73 (95% CI: 1.14, 6.55; p < 0.05) for the daily consumption of dairy products during the pre-school period and 2.40 (95% CI: 1.01, 5.70; p < 0.05) for the daily consumption of dairy products during the school period. Two clusters of women were established. In the S1 cluster, low BMD (below -1 SD) was associated with older age (? 50 years), lack of menstrual cycle. In the S2 cluster, regular BMD (?-1 SD) was related to younger aged women (<50 years), presence of menstrual cycle, consumption of higher level of dairy products (?28 servings/week) during adulthood and daily intake of dairy products during childhood and adolescence. The results indicate that good bone health to the larg e extent depended upon the combined impact of dietary factors and some non-modifiable risk factors of osteoporosis such as age and the presence of menstruation. Consumption of dairy products in childhood and adolescence may improve bone mineral density and reduce the risk of osteoporosis in adult women. PMID:23863825

Wadolowska, Lidia; Sobas, Kamila; Szczepanska, Justyna W; Slowinska, Malgorzata A; Czlapka-Matyasik, Magdalena; Niedzwiedzka, Ewa

2013-07-01

158

Isolation, Partial Amino Acid Sequence, and Immunohistochemical Localization of a Brain-Specific Calcium-Binding Protein  

Microsoft Academic Search

A calcium-binding protein (protein 10) having a molecular mass of 29 kDa and an isoelectric point of 5.3 was purified from guinea pig brain. The amino acid sequence of fragments from proteolytic digestion of protein 10 revealed an 86% sequence identity with a calcium-binding protein (calretinin) found in chicken retina. Polyclonal antibodies against protein 10 revealed a specific distribution of

Lois Winsky; Hiroyasu Nakata; Brian M. Martin; David M. Jacobowitz

1989-01-01

159

Role of Postoperative Vitamin D and/or Calcium Routine Supplementation in Preventing Hypocalcemia After Thyroidectomy: A Systematic Review and Meta-Analysis  

PubMed Central

Background. Transient hypocalcemia is a frequent complication after total thyroidectomy. Routine postoperative administration of vitamin D and calcium can reduce the incidence of symptomatic postoperative hypocalcemia. We performed a systematic review to assess the effectiveness of this intervention. The primary aim was to evaluate the efficacy of routine postoperative oral calcium and vitamin D supplementation in preventing symptomatic post-thyroidectomy hypocalcemia. The second aim was to draw clear guidelines regarding prophylactic calcium and/or vitamin D therapy for patients after thyroidectomy. Methods. We identified randomized controlled trials comparing the administration of vitamin D or its metabolites to calcium or no treatment in adult patients after thyroidectomy. The search was performed in PubMed, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Google Scholar, and Web of Knowledge databases. Patients with a history of previous neck surgery, calcium supplementation, or renal impairment were excluded. Results. Nine studies with 2,285 patients were included: 22 in the vitamin D group, 580 in the calcium group, 792 in the vitamin D and calcium group, and 891 in the no intervention group, with symptomatic hypocalcemia incidences of 4.6%, 14%, 14%, and 20.5%, respectively. Subcomparisons demonstrated that the incidences of postoperative hypocalcemia were 10.1% versus 18.8% for calcium versus no intervention and 6.8% versus 25.9% for vitamin D and calcium versus no intervention. The studies showed a significant range of variability in patients' characteristics. Conclusions. A significant decrease in postoperative hypocalcemia was identified in patients who received routine supplementation of oral calcium or vitamin D. The incidence decreased even more with the combined administration of both supplements. Based on this analysis, we recommend oral calcium for all patients following thyroidectomy, with the addition of vitamin D for high-risk individuals.

Alhefdhi, Amal; Mazeh, Haggi

2013-01-01

160

Lipoic Acid Prevents the Changes of Intracellular Lipid Partitioning by Free Fatty Acid  

PubMed Central

Background/Aims It is suggested that the hepatic lipid composition is more important than lipid quantity in the pathogenesis of non-alcoholic steatohepatitis. We examined whether lipoic acid (LA) could alter intrahepatic lipid composition and free cholesterol distribution. Methods HepG2 cells were cultured with palmitic acid (PA) with and without LA. Apoptosis, changes of the mitochondrial structure, intracellular lipid partitioning, and reactive oxygen species (ROS) activity were measured. Results Free fatty acid (FA) increased apoptosis, and LA co-treatment prevented this lipotoxicity (apoptosis in controls vs PA vs PA+LA, 0.5% vs 19.5% vs 1.6%, p<0.05). LA also restored the intracellular mitochondrial DNA copy number (553±33.8 copies vs 291±14.55 copies vs 421±21.05 copies, p<0.05) and reversed the morphological changes induced by PA. In addition, ROS was increased in response to PA and was decreased in response to LA co-treatment (41,382 relative fluorescence unit [RFU] vs 43,646 RFU vs 41,935 RFU, p<0.05). LA co-treatment increased the monounsaturated and polyunsaturated FA concentrations and decreased the total saturated FA fraction. It also prevented the movement of intracellular free cholesterol from the cell membrane to the cytoplasm. Conclusions LA opposes free FA-generated lipotoxicity by altering the intracellular lipid composition and free cholesterol distribution.

Kim, Dong Chan; Jang, Eun Chul; Kim, Sang Heum; Kim, Eun Kyung; Lee, Sang Pyo; Lee, Kang Nyeong; Lee, Hang Lak; Lee, Oh Young; Yoon, Byung Chul; Choi, Ho Soon

2013-01-01

161

Phase diagram for controlled crystallization of calcium phosphate under acidic organic monolayers  

NASA Astrophysics Data System (ADS)

The effect of ionic concentration and pH on matrix-regulated crystallization may be important in biomineralization processes and biomimetic synthesis of materials. This effect in the system of calcium phosphate solution under stearic acid monolayers was investigated. In experiments, the solution conditions ranged in concentration of Ca ion of 0.1-20mM and in pH of 5.3-7.0. It was found that at the initial stage of the controlled crystallization, the (0001)-oriented hydroxyapatite (HAp) precipitations under the acidic monolayers always occur. At solution conditions near the solubility isotherms of octacalcium phosphate (OCP) and dicalcium phosphate dihydrate (DCPD) in the solubility phase diagram, precipitations of OCP and DCPD phases can form together with HAp precipitation, respectively. Orientations of DCPD or OCP phase precipitations were irregular.

Cui, F. Z.; Zhou, L. F.; Cui, H.; Ma, C. L.; Lu, H. B.; Li, H. D.

1996-12-01

162

Fluorescent-tagged acrylic acid-allylpolyethoxy carboxylate copolymer as a green inhibitor for calcium phosphate in industrial cooling systems  

Microsoft Academic Search

Allyloxy polyethoxy ether (APEG) and succinic anhydride were used to prepare allyloxy polyethoxy carboxylate (APEL). The 8-hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt (PY) was reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA). APEL and PA were copolymerized with acrylic acid (AA) to synthesize PA-tagged no phosphate and nitrogen free calcium phosphate inhibitor AA–APEL–PA. Structures of

Guangqing Liu; Jingyi Huang; Yuming Zhou; Qingzhao Yao; Yong Yang; Lei Ling; Huchuan Wang; Wendao Wu; Wei Sun; Zhengjun Hu

2012-01-01

163

Supplementing a low-protein diet with dibasic amino acids increases urinary calcium excretion in young women.  

PubMed

Increasing dietary protein within a physiologic range stimulates intestinal calcium absorption, but it is not known if specific amino acids or dietary protein as a whole are responsible for this effect. Therefore, we selectively supplemented a low-protein (0.7 g/kg) diet with either the calcium-sensing receptor-activating amino acids (CaSR-AAAs) L-tryptophan, L-phenylalanine, and L-histidine, or the dibasic amino acids (DAAs) L-arginine and L-lysine, to achieve intakes comparable to the content of a high-protein diet (2.1 g/kg) and measured intestinal calcium absorption. Fourteen young women took part in a placebo-controlled, double-blind, crossover feeding trial in which each participant ingested a 6-d low-protein diet supplemented with CaSR-AAAs, DAAs, or methylcellulose capsules (control) after an 11-d adjustment period. All participants ingested all 3 diets in random order. Intestinal calcium absorption was measured between days 5 and 6 using dual-stable calcium isotopes ((42)Ca, (43)Ca, and (44)Ca). There was no difference in calcium absorption between the diet supplemented with CaSR-AAAs (22.9 ± 2.0%) and the control diet (22.3 ± 1.4%) (P = 0.64). However, calcium absorption tended to be greater during the DAA supplementation period (25.2 ± 1.4%) compared with the control diet period (22.3 ± 1.4%) (P < 0.10). Larger and longer clinical trials are needed to clarify the possible benefit of arginine and lysine on calcium absorption. PMID:24431325

Bihuniak, Jessica D; Sullivan, Rebecca R; Simpson, Christine A; Caseria, Donna M; Huedo-Medina, Tania B; O'Brien, Kimberly O; Kerstetter, Jane E; Insogna, Karl L

2014-03-01

164

Preventive and therapeutic effects of caffeic acid against inflammatory injury in striatum of MPTP-treated mice.  

PubMed

Preventive or therapeutic effects of caffeic acid in brain of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated mice against inflammatory injury were examined. Caffeic acid at 0.5, 1 or 2% was supplied either pre-intake or post-intake for 4 weeks. Brain caffeic acid content was increased by caffeic acid pre-intake at 1 and 2%, and post-intake at 2% (P < 0.05). MPTP treatment enhanced the release of interleukin (IL)-1beta, IL-6, tumor necrosis factor (TNF)-alpha, IL-4 and IL-10 (P < 0.05). Pre-intake of caffeic acid decreased the production of test cytokines (P < 0.05); however, post-intake only at 2% reduced the level of IL-1beta, IL-6 and TNF-alpha (P < 0.05). MPTP treatment up-regulated mRNA expression of inducible nitric oxide synthase (iNOS), neuronal NOS, cyclooxygenase (COX)-2, glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1, and increased production of nitric oxide (NO) and prostaglandin E? (PGE?) (P < 0.05). Caffeic acid pre-intake at test doses and post-intake at 2% declined the expression of iNOS, COX-2 and GFAP; and lowered the production of NO and PGE? (P < 0.05). MPTP treatment suppressed mRNA expression of brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor and tyrosine hydroxylase (TH), and lowered dopamine level (P < 0.05). Caffeic acid pre-intake retained the expression of these factors, maintained TH activity and protein production, and dopamine synthesis (P < 0.05). These results suggest that caffeic acid is a potent neuroprotective agent against the development of Parkinson's disease. PMID:21970803

Tsai, Shih-jei; Chao, Che-yi; Yin, Mei-chin

2011-11-30

165

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.

2014-01-01

166

In vivo evaluation of teicoplanin- and calcium sulfate-loaded PMMA bone cement in preventing implant-related osteomyelitis in rats.  

PubMed

The objective of this study was to evaluate the efficacy of teicoplanin- and calcium sulphate-loaded polymethylmethacrylate (PMMA) bone cements in preventing experimental implant-related osteomyelitis in rats. Four groups of antibiotic-loaded rods were prepared and were implanted into the lateral condylus of the rat femur after inoculation of Staphylococcus aureus. The effectiveness of these were assessed microbiologically, radiographically, and histopathologically. Radiographic evaluation revealed a significant reduction of periostal reaction and osteolysis in rats that received calcium sulphate- and teicoplanin-loaded rods. Histopathological evaluation confirmed these results. Acute infection and bone necrosis were found to be significantly lower in rats that had received calcium sulphate- and teicoplanin-loaded rods. The addition of calcium sulfate to teicoplanin-loaded PMMA bone cement appeared satisfactory as an antibiotic-carrying system for prophylaxis of experimental implant-related osteomyelitis, but further investigations are needed to reach definitive statements for clinical applications. PMID:17267341

Tuzuner, T; Sencan, I; Ozdemir, D; Alper, M; Duman, S; Yavuz, T; Yildirim, M

2006-12-01

167

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

PubMed

Optimized conditions were obtained by one-factor-at-a-time test (OFAT) and ternary quadratic regression orthogonal composite design (TQROCD) respectively. By pulse electric fields (PEF) technology, the process of eggshell calcium citrate malate (ESCCM), eggshell calcium citrate (ESCC) and eggshells calcium malate (ESCM) were comprehensive compared. The levels of tartrate-resistant acid phosphatase (TRAP) and the bioavailability on mice fed with eggshell calcium citrate malate (ESCCM) treated by pulsed electric field (PEF) were evaluated. Results showed that the rates of calcium dissolution of the different acids studied can be arranged as ESCCM (7.90 mg/mL)>ESCC (7.12 mg/mL)>ESCM (7.08 mg/mL) from highest to lowest rate of dissolution. At the same dose 133.0 mg kg(-1) d(-1), the levels of TRAP in the ESCCM treatment groups were significantly lower than those in ESCM and ESCC (P<0.05). Bone calcium content in the mice fed with ESCCM was generally higher than fed with ESCM and ESCC. PMID:23603074

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

2013-07-01

168

Rap1 signaling prevents L type calcium channel dependent neurotransmitter release  

PubMed Central

The small GTPase Rap1 contributes to fear learning and cortico-amygdala plasticity by inhibiting glutamate release from cortical neurons, but mechanisms of this inhibition remain unknown. On the other hand, L-type calcium channels (LTCC) become involved in glutamate release upon fear learning and LTP induction. Here, we show that Rap1 deletion in mouse primary cortical neurons increases synaptic vesicle exocytosis without altering endocytosis or vesicle pool size, in a LTCC dependent manner. We identify Erk1/2 as the downstream effector of Rap1 and show that its inhibition increases plasma membrane expression of LTCC near presynaptic terminals. We propose that the Rap1 signaling enables plasticity and fear learning by regulating LTCC at cortico-amygdala synapses.

Subramanian, Jaichandar; Dye, Louis; Morozov, Alexei

2013-01-01

169

Rap1 signaling prevents L-type calcium channel-dependent neurotransmitter release.  

PubMed

The small GTPase Rap1 contributes to fear learning and cortico-amygdala plasticity by inhibiting glutamate release from cortical neurons, but mechanisms of this inhibition remain unknown. Conversely, L-type calcium channels (LTCCs) become involved in glutamate release after fear learning and LTP induction. Here, we show that Rap1 deletion in mouse primary cortical neurons increases synaptic vesicle exocytosis without altering endocytosis or vesicle pool size in an LTCC-dependent manner. We identify Erk1/2 as the downstream effector of Rap1 and show that its inhibition increases plasma membrane expression of LTCCs near presynaptic terminals. We propose that the Rap1 signaling enables plasticity and fear learning by regulating LTCCs at cortico-amygdala synapses. PMID:23616533

Subramanian, Jaichandar; Dye, Louis; Morozov, Alexei

2013-04-24

170

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

171

Mechanical and acid neutralizing properties and bacteria inhibition of amorphous calcium phosphate dental nanocomposite  

PubMed Central

Dental composites do not hinder bacteria colonization and plaque formation. Caries at the restoration margins is a frequent reason for replacement of existing restorations, which accounts for 50 to 70% of all restorations. The objectives of this study were to examine the filler level effect on nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP) and investigate the load-bearing and acid-neutralizing properties and bacteria inhibition. NACP with 116-nm particle size were synthesized via a spray-drying technique and incorporated into a resin. Flexural strength of nanocomposite with 10 to 30% NACP fillers matched the strength of a commercial hybrid composite (p > 0.1). Nanocomposite with 40% NACP matched the strength of a microfill composite, which was 2-fold that of a resin-modified glass ionomer. Nanocomposite with 40% NACP neutralized a lactic acid solution of pH 4 by rapidly increasing the pH to 5.69 in 10 min. In contrast, the commercial controls had pH staying at near 4. Using Streptoccocus mutans, an agar disk-diffusion test showed no inhibition zone for commercial controls. In contrast, the inhibition zone was (2.5 ± 0.7) mm for nanocomposite with 40% NACP. Crystal violet staining showed that S. mutans coverage on nanocomposite was 1/4 that on commercial composite. In conclusion, novel calcium–phosphate nanocomposite matched the mechanical properties of commercial composite and rapidly neutralized lactic acid of pH 4. The nanocomposite appeared to moderately reduce the S. mutans growth, and further study is needed to obtain strong antimicrobial properties. The new nanocomposite may have potential to reduce secondary caries and restoration fracture, two main challenges facing tooth cavity restorations.

Moreau, Jennifer L.; Sun, Limin; Chow, Laurence C.; Xu, Hockin H. K.

2012-01-01

172

Mechanical and acid neutralizing properties and bacteria inhibition of amorphous calcium phosphate dental nanocomposite.  

PubMed

Dental composites do not hinder bacteria colonization and plaque formation. Caries at the restoration margins is a frequent reason for replacement of existing restorations, which accounts for 50 to 70% of all restorations. The objectives of this study were to examine the filler level effect on nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP) and investigate the load-bearing and acid-neutralizing properties and bacteria inhibition. NACP with 116-nm particle size were synthesized via a spray-drying technique and incorporated into a resin. Flexural strength of nanocomposite with 10 to 30% NACP fillers matched the strength of a commercial hybrid composite (p > 0.1). Nanocomposite with 40% NACP matched the strength of a microfill composite, which was 2-fold that of a resin-modified glass ionomer. Nanocomposite with 40% NACP neutralized a lactic acid solution of pH 4 by rapidly increasing the pH to 5.69 in 10 min. In contrast, the commercial controls had pH staying at near 4. Using Streptoccocus mutans, an agar disk-diffusion test showed no inhibition zone for commercial controls. In contrast, the inhibition zone was (2.5 ± 0.7) mm for nanocomposite with 40% NACP. Crystal violet staining showed that S. mutans coverage on nanocomposite was 1/4 that on commercial composite. In conclusion, novel calcium-phosphate nanocomposite matched the mechanical properties of commercial composite and rapidly neutralized lactic acid of pH 4. The nanocomposite appeared to moderately reduce the S. mutans growth, and further study is needed to obtain strong antimicrobial properties. The new nanocomposite may have potential to reduce secondary caries and restoration fracture, two main challenges facing tooth cavity restorations. PMID:21504057

Moreau, Jennifer L; Sun, Limin; Chow, Laurence C; Xu, Hockin H K

2011-07-01

173

[Regulation function of calcium on photosynthesis of Dimocarpus longana Lour. cv. wulongling under simulated acid rain stress].  

PubMed

Studies on the regulation function of calcium on photosynthesis of Dimocarpus longana under simulated acid rain stress showed that the photoreduction activity of chloroplasts was activated when the concentration of calcium ion in reaction medium ranged from 0 to 5 mmol.L-1, and peaked at the 3.5 mmol.L-1, which was 41.90% higher than that of control. Conversely, the activity of chloroplasts reduced 26.06% in the reaction medium with a concentration of 2 mmol.L-1 EGTA, as compared with the control. Both Mn2+ and Mg2+ could inhibit photoreduction activity. The photophosphorylation activity increased when the concentration of calcium ion in reaction medium ranged from 0 to 6 mmol.L-1, and peaked at the 4.5 mmol.L-1, while superoxidase dismutase (SOD) activity rose from 0 to 6 mmol.L-1 and peaked at 6 mmol.L-1. Calcium ion with the concentration of both 10 mmol.L-1 and 15 mmol.L-1 could increase the content of chlorophyll(Chl), stabilize the membrane structure of leaf discs, and reduce the membrane permeability under simulated acid rain with pH value of 3.0. The effect in 15 mmol.L-1 were better than in 10 mmol.L-1. However, the injury of acid rain to leaves was strengthened when the concentration of calcium was higher than 20 mmol.L-1. Net photosynthesis rate (Pn) rose when leaves sprayed with 15 mmol.L-1 Ca(NO3)2 before treatment of acid rain stress of pH 2.5. All of the results represented the excellent protection function of calcium on D. longana leaves under simulated acid rain. PMID:12561164

Qiu, Dongliang; Liu, Xinghui; Guo, Suzhi

2002-09-01

174

Effects of Monocarboxylic Acid Addition on Crystallization of Calcium Phosphate in a Hydrogel Matrix  

NASA Astrophysics Data System (ADS)

In biomineralization, it is thought that water-soluble organic substances control crystal growth of minerals in hard tissues. The roles of organic substances are not well understood, because the biomineralization process is established by complicated parameters. Crystal growth in hydrogel matrixes can be regarded as simplified model system of biomineralization. In the present study, we investigated the effects of propionic acid (Pro) on crystalline phases and crystal morphologies of calcium phosphate formed in polymeric hydrogel matrixes as the model system of biomineralization. Crystalline phase of the precipitates was octacalcium phosphate (OCP) with spherical shape regardless of Pro concentrations. The fibrous crystals formed under the condition without addition of Pro. The crystal morphologies composing spherical crystals were changed from fibrous to plate-like shape with increasing Pro concentrations. Generally, OCP crystal has plate-like shape exposing (100) face, which calcium ions exist on. Therefore, crystal growth rate of [100] direction of OCP was decreased by Pro adsorbed on (100) face. As a result, crystal morphology composing spherulite became plate-like shape with increasing Pro concentrations.

Yokoi, T.; Kawashita, M.; Ohtsuki, C.

2011-10-01

175

Isolation from human calcium oxalate renal stones of nephrocalcin, a glycoprotein inhibitor of calcium oxalate crystal growth. Evidence that nephrocalcin from patients with calcium oxalate nephrolithiasis is deficient in gamma-carboxyglutamic acid.  

PubMed Central

We have determined that the organic matrix of calcium oxalate kidney stones contains a glycoprotein inhibitor of calcium oxalate crystal growth (nephrocalcin) that resembles nephrocalcin present in the urine of patients with calcium oxalate stones and differs from nephrocalcin from the urine of normal people. Pulverized calcium oxalate renal stones were extracted with 0.05 M EDTA, pH 8.0; nephrocalcin eluted in five peaks using DEAE-cellulose column chromatography, and each peak was further resolved by Sephacryl S-200 column chromatography. Four of the five DEAE peaks corresponded to those usually found in nephrocalcin from urine; the fifth eluted at a lower ionic strength than any found in urine. Amino acid compositions and surface properties of nephrocalcins isolated from kidney stones closely resembled those of nephrocalcins isolated from urine of stone-forming patients: they differed from normal in lacking gamma-carboxyglutamic acid residues, and in forming air-water interfacial films that were less stable than those formed by nephrocalcin from normal urine. Images

Nakagawa, Y; Ahmed, M; Hall, S L; Deganello, S; Coe, F L

1987-01-01

176

Inhibition of aldose reductase prevents endotoxin-induced inflammation by regulating the arachidonic acid pathway in murine macrophages.  

PubMed

The bacterial endotoxin lipopolysaccharide (LPS) is known to induce release of arachidonic acid (AA) and its metabolic products, which play important roles in the 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 RAW264.7 macrophages and AR-knockout mouse 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 by fidarestat prevented the expression of AA-metabolizing enzymes such as COX-2 and LOX-5 in RAW264.7 cells and AR-knockout mouse-derived peritoneal macrophages. LPS-induced expression of AA-metabolizing enzymes and their catalyzed metabolic products was 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-?B, and EGR-1, a transcriptional regulator of mPGES-1, which in collaboration with COX-2 leads to the production of PGE2, was also significantly prevented by AR inhibition. Taken together, our results indicate that AR mediates LPS-induced inflammation by regulating the AA-metabolic pathway and thus provide a novel role for AR inhibition in preventing inflammatory complications such as sepsis. PMID:21856412

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

2011-11-01

177

Poly(?-glutamic acid)/Silica Hybrids with Calcium Incorporated in the Silica Network by Use of a Calcium Alkoxide Precursor.  

PubMed

Current materials used for bone regeneration are usually bioactive ceramics or glasses. Although they bond to bone, they are brittle. There is a need for new materials that can combine bioactivity with toughness and controlled biodegradation. Sol-gel hybrids have the potential to do this through their nanoscale interpenetrating networks (IPN) of inorganic and organic components. Poly(?-glutamic acid) (?-PGA) was introduced into the sol-gel process to produce a hybrid of ?-PGA and bioactive silica. Calcium is an important element for bone regeneration but calcium sources that are used traditionally in the sol-gel process, such as Ca salts, do not allow Ca incorporation into the silicate network during low-temperature processing. The hypothesis for this study was that using calcium methoxyethoxide (CME) as the Ca source would allow Ca incorporation into the silicate component of the hybrid at room temperature. The produced hybrids would have improved mechanical properties and controlled degradation compared with hybrids of calcium chloride (CaCl2 ), in which the Ca is not incorporated into the silicate network. Class II hybrids, with covalent bonds between the inorganic and organic species, were synthesised by using organosilane. Calcium incorporation in both the organic and inorganic IPNs of the hybrid was improved when CME was used. This was clearly observed by using FTIR and solid-state NMR spectroscopy, which showed ionic cross-linking of ?-PGA by Ca and a lower degree of condensation of the Si species compared with the hybrids made with CaCl2 as the Ca source. The ionic cross-linking of ?-PGA by Ca resulted in excellent compressive strength and reduced elastic modulus as measured by compressive testing and nanoindentation, respectively. All hybrids showed bioactivity as hydroxyapatite (HA) was formed after immersion in simulated body fluid (SBF). PMID:24838668

Poologasundarampillai, Gowsihan; Yu, Bobo; Tsigkou, Olga; Wang, Daming; Romer, Frederik; Bhakhri, Vineet; Giuliani, Finn; Stevens, Molly M; McPhail, David S; Smith, Mark E; Hanna, John V; Jones, Julian R

2014-06-23

178

Inertisation of galvanic sludge with calcium oxide, activated carbon, and phosphoric acid.  

PubMed

In this study we compared three methods for the treatment of electroplating sludge highly loaded with zinc and iron: (1) calcium oxide-based solidification/stabilisation; (2) conversion into inert material by adsorption of organic and inorganic pollutants onto activated carbon; and (3) conversion of mobile waste components into insoluble phosphates. All three methods proved highly efficient in the conversion of hazardous waste into inert material. Under optimum treatment conditions zinc concentration in the leachate of solidified waste was reduced by 99.7 % compared to untreated sludge. Zinc retention efficiency in the waste treated with activated carbon and phosphoric acid was 99.9 % and 98.7 %, respectively. The advantages of electroplating sludge treatment with activated carbon over the other two methods are high sorption capacity, insignificant pH and volume changes of the sludge, and simple use. PMID:23152383

Oreš?anin, Višnja; Lovren?i? Mikeli?, Ivanka; Kollar, Robert; Mikuli?, Nenad; Meduni?, Gordana

2012-09-01

179

Design of chiral LC separations for calcium antagonists on alpha 1-acid glycoprotein and ovomucoid columns.  

PubMed

Three chiral calcium antagonist drugs, gallopamil and two dihydropyridine derivatives, have been successfully separated within short retention times using both the alpha 1-acid glycoprotein chiral stationary phase (Chiral-AGP) and the ovomucoid column (Ultron ES-OVM). Aqueous buffer at defined pH is modified by the addition of an organic component, in order to modulate the retention properties of each system. Optimization of pH and organic modifier is carried out using the modified simplex method, with Kaiser's peak separation function as a criterion. The influence of pH and percentage of organic modifier on retention, selectivity, resolution and column performance are discussed for the two dihydropyridines analysed on Chiral-AGP and Ultron ES-OVM stationary phases. A new method is proposed as a new chiral system suitability test for these protein-based phases, utilizing a racemic mixture of closely eluting verapamil enantiomers as a probe. PMID:1298397

De Lorenzi, E; Fell, A F; Caccialanza, G; Massolini, G; Kitsos, M

1992-01-01

180

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

181

Two Metabotropic ?-Aminobutyric Acid Receptors Differentially Modulate Calcium Currents in Retinal Ganglion Cells  

PubMed Central

Metabotropic ?-aminobutyric acid (GABA) receptors were studied in amphibian retinal ganglion cells using whole cell current and voltage clamp techniques. The aim was to identify the types of receptor present and their mechanisms of action and modulation. Previous results indicated that ganglion cells possess two ionotropic GABA receptors: GABAAR and GABACR. This study demonstrates that they also possess two types of metabotropic GABAB receptor: one sensitive to baclofen and another to cis-aminocrotonic acid (CACA). The effects of these selective agonists were blocked by GDP-?-S. Baclofen suppressed an ?-conotoxin–GVIA-sensitive barium current, and this action was reversed by prepulse facilitation, indicative of a direct G-protein pathway. The effect of baclofen was also partially occluded by agents that influence the protein kinase A (PKA) pathway. But the effect of PKA activation was unaffected by prepulse facilitation, indicating PKA acted through a parallel pathway. Calmodulin antagonists reduced the action of baclofen, whereas inhibitors of calmodulin phosphatase enhanced it. Antagonists of internal calcium release, such as heparin and ruthenium red, did not affect the baclofen response. Thus, the baclofen-sensitive receptor may respond to influx of calcium. The CACA-sensitive GABA receptor reduced current through dihydropyridine-sensitive channels. Sodium nitroprusside and 8-bromo-cGMP enhanced the action of CACA, indicating that a nitric oxide system can up-regulate this receptor pathway. CACA-sensitive and baclofen-sensitive GABAB receptors reduced spike activity in ganglion cells. Overall, retinal ganglion cells possess four types of GABA receptor, two ionotropic and two metabotropic. Each has a unique electrogenic profile, providing a wide range of neural integration at the final stage of retinal information processing.

Zhang, Jian; Shen, Wen; Slaughter, Malcolm M.

1997-01-01

182

Effect of fruit on net acid and urinary calcium excretion in an acute feeding trial of women  

Microsoft Academic Search

ObjectiveConsumption of fruits and vegetables has been implicated in lowering net acid excretion (NAE), but few studies have directly examined NAE and urinary calcium effects. Further, there is no evidence that only fresh fruits and vegetables must be consumed for a beneficial effect on bone.

Janet Amy Bell; Susan Joyce Whiting

2004-01-01

183

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

184

Comparative analysis of calcium gluconate and sodium gluconate techniques for the production of gluconic acid by Aspergillus niger  

Microsoft Academic Search

Sodium gluconate and calcium gluconate methods are important techniques available for gluconic acid fermentation. The comparative analysis of these fermentations has been addressed using Aspergillus niger. The techniques are equally influenced by the spores age in slant growth, inoculum level in germination and production media, different levels of Fe, Cu, Zn and Mn. Sodium gluconate method is promising with respect

D. Subba Rao; T. Panda

1993-01-01

185

Calcium and temperature effects on seedling exudation and root rot infection of common bean on an acid sandy soil  

Microsoft Academic Search

Soil born fungi such as Phytium ultimum, Fusarium ssp., and Rhizoctonia solani (Kühn) severely restrict stand establishment of common bean (Phaseolus vulgaris L.) on acid soils of the Tropics. Calcium application is known to alleviate fungal infection in many legumes but the causes are still unclear. To investigate environmental factors and physiological mechanisms involved, growth chamber experiments were conducted with

A. Buerkert; H. Marschner

1992-01-01

186

The effects of citric and acetic acids on the formation of calcium-deficient hydroxyapatite at 38 °C  

Microsoft Academic Search

This study is concerned with the formation of calcium-deficient hydroxyapatite at physiological temperature. Isothermal calorimetry, solution chemistry, scanning electron microscopy, BET surface area analyses and FTIR spectroscopy were used to characterize the kinetics of HAp formation and the microstructure of the HAp formed in varying concentrations of citric and acetic acids, and in deionized water. The kinetics of HAp formation

K. S. Tenhuisen; P. W. Brown

1994-01-01

187

Application of 1-methylcyclopropene, calcium chloride and calcium amino acid chelate on fresh-cut cantaloupe muskmelon  

Microsoft Academic Search

The objective of this work was to determine the effects of postharvest application of 1-methylcyclopropene (1-MCP) and two calcium salts, applied individually or combined, on firmness and visual quality of fresh-cut muskmelon stored in air, for 18 days. Two sets of fruits, one of them exposed to 1-MCP at 300 nL L -1 , were cut into cubes, dipped in

Francisca Ligia

2008-01-01

188

Final Report On the Safety Assessment of Glycolic Acid, Ammonium, Calcium, Potassium, and Sodium Glycolates, Methyl, Ethyl, Propyl, and Butyl Glycolates, and Lactic Acid, Ammonium, Calcium, Potassium, Sodium, and Tea-Lactates, Methyl, Ethyl, Isopropyl, and Butyl Lactates, and Lauryl, Myristyl, and Cetyl Lactates  

Microsoft Academic Search

This report provides a review of the safety of Glycolic Acid, Ammonium, Calcium, Potassium, and Sodium Glycolates, Methyl, Ethyl, Propyl, and Butyl Glycolates, Lactic Acid, Ammonium, Calcium, Potassium, Sodium, and TEA-Lactates, and Lauryl, Myristyl, and Cetyl Lactates. These ingredients belong to a group known as alpha-hydroxy acids (AHAs). Products containing these ingredients may be for consumer use, salon use, or

F. A. Andersen

1998-01-01

189

Acid-sensing ion channel 3 decreases phosphorylation of extracellular signal-regulated kinases and induces synoviocyte cell death by increasing intracellular calcium  

PubMed Central

Introduction Acid-sensing ion channel 3 (ASIC3) is expressed in synoviocytes, activated by decreases in pH, and reduces inflammation in animal models of inflammatory arthritis. The purpose of the current study was to characterize potential mechanisms underlying the control of inflammation by ASIC3 in fibroblast-like synoviocytes (FLS). Methods Experiments were performed in cultured FLS from wild-type (WT) and ASIC3-/- mice, ASIC1-/- mice, and people with rheumatoid arthritis. We assessed the effects of acidic pH with and without interleukin-1? on FLS and the role of ASICs in modulating intracellular calcium [Ca2+]i, mitogen activated kinase (MAP kinase) expression, and cell death. [Ca2+]i was assessed by fluorescent calcium imaging, MAP kinases were measured by Western Blots; ASIC, cytokine and protease mRNA expression were measured by quantitative PCR and cell death was measured with a LIVE/DEAD assay. Results Acidic pH increased [Ca2+]i and decreased p-ERK expression in WT FLS; these effects were significantly smaller in ASIC3-/- FLS and were prevented by blockade of [Ca2+]i. Blockade of protein phosphatase 2A (PP2A) prevented the pH-induced decreases in p-ERK. In WT FLS, IL-1? increases ASIC3 mRNA, and when combined with acidic pH enhances [Ca2+]i, p-ERK, IL-6 and metalloprotienase mRNA, and cell death. Inhibitors of [Ca2+]i and ERK prevented cell death induced by pH 6.0 in combination with IL-1? in WT FLS. Conclusions Decreased pH activates ASIC3 resulting in increased [Ca2+]i, and decreased p-ERK. Under inflammatory conditions, acidic pH results in enhanced [Ca2+]i and phosphorylation of extracellular signal-regulated kinase that leads to cell death. Thus, activation of ASIC3 on FLS by acidic pH from an inflamed joint could limit synovial proliferation resulting in reduced accumulation of inflammatory mediators and subsequent joint damage.

2014-01-01

190

I. Effect of acetylsalicylic acid upon gastric activity and the modifying action of calcium gluconate and sodium bicarbonate  

Microsoft Academic Search

Conclusions  1. In some normal human subjects and normal dogs, single oral doses (1–2 gms.) of acetylsalicylic acid caused gastric retention;\\u000a the addition of calcium gluconate tended to increase the degree of retention while the addition of sodium bicarbonate increased\\u000a the rate of gastric evacuation.\\u000a \\u000a 2. In normal human subjects and normal dogs, single oral doses of acetylsalicylic acid increased the

J. G. Schnedorf; W. B. Bradley; A. C. Ivy

1936-01-01

191

Effect of poly(aspartic acid) on calcium phosphate removal from stainless steel tubing under turbulent flow conditions  

NASA Astrophysics Data System (ADS)

Calcium phosphate deposition causes cleaning problems in a number of situations including water treatment, dairy processing, and dental applications. This problem is exacerbated by the limited choices of cleaning chemicals that meet environmental regulations. To promote the development of biodegradable, non-toxic alternatives, this research examines the removal of calcium phosphate deposits consisting of brushite (dicalcium phosphate dihydrate; DCPD) and a mixture of hydroxyapatite (HAP) and DCPD from stainless steel in the presence of poly(aspartic acid) and its sodium salt (PASP). The effects of solvent pH, PASP concentration, and flow rate on the calcium phosphate removal rates are measured from stainless steel tubing under turbulent flow conditions using a solid scintillation detection technique. A mechanistic evaluation of the cleaning data in the absence of PASP indicates that DCPD removal is dominated by shear while HAP/DCPD deposit removal is limited by a combination of mass transfer and interfacial processes. Although the removal mechanisms differ, the results conclusively show that PASP promotes calcium phosphate removal under conditions that favor calcium sequestration in both cases. An in-depth study of DCPD removal in the presence of PASP reveals that this additive is most effective under conditions where calcium sequestration and phosphate protonation occur simultaneously.

Littlejohn, Felicia

192

Calcium stone disease: a multiform reality  

Microsoft Academic Search

In calcium renal stones, calcium oxalate and calcium phosphate in various crystal forms and states of hydration can be identified. Calcium oxalate monohydrate (COM) or whewellite and calcium oxalate dihydrate (COD) or weddellite are the commonest constituents of calcium stones. Calcium oxalate stones may be pure or mixed, usually with calcium phosphate or sometimes with uric acid or ammonium urate.

Alberto Trinchieri; Chiara Castelnuovo; Renata Lizzano; Giampaolo Zanetti

2005-01-01

193

Hypercalcemia, metabolic alkalosis and renal failure secondary to calcium bicarbonate intake for osteoporosis prevention--'modern' milk alkali syndrome: a case report.  

PubMed

We report a case of a patient presenting with a triad of hypercalcemia, metabolic alkalosis and renal failure secondary to calcium bicarbonate intake for osteoporosis prevention. It is the classical presentation of the "modern" milk alkali syndrome that presents several characteristics distinguishing it from the "old" syndrome described secondary to peptic ulcer disease treatment. Milk alkali syndrome affects middle-aged female patients taking over-the-counter calcium carbonate. Clinically, these patients present in an acute hypercalcemia crisis, responding rapidly to hydration. The phosphorus level is normal to low. Bisphosphonate should be used cautiously due to the risk of symptomatic hypocalcemia. PMID:19918560

Waked, Alain; Geara, Abdallah; El-Imad, Badiaa

2009-01-01

194

Evaluation of agents for preventing precipitation of ferric hydroxide from spent treating acid  

Microsoft Academic Search

Studies were performed, over a temperature range of 100° to 400°F, to evaluate the effectiveness of commonly used chemical agents for preventing precipitation of ferric hydroxide from spent treating acid. Citric acid, ethylenediaminetetraacetic acid (EDTA) and erythorbic acid were all shown to be effective iron stabilizers at temperatures up to at least 400°F. In some cases, efficiency actually increased with

Crowe

1984-01-01

195

Dissolution of steelmaking slags in acetic acid for precipitated calcium carbonate production  

Microsoft Academic Search

A promising option for long-term storage of CO2 is to fixate carbon dioxide as magnesium- and calcium carbonates. Slags from iron and steel works are potential raw materials for carbonation due to their high contents of calcium silicates. Precipitated calcium carbonate (PCC) is used as filler and coating materials in paper. If slag could be used instead of limestone for

Sebastian Teir; Sanni Eloneva; Carl-Johan Fogelholm; Ron Zevenhoven

2007-01-01

196

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

197

The influence of aliphatic amines, diamines, and amino acids on the polymorph of calcium carbonate precipitated by the introduction of carbon dioxide gas into calcium hydroxide aqueous suspensions  

NASA Astrophysics Data System (ADS)

The influence of aliphatic organic additives including amines, diamines and amino acids, on the polymorph of calcium carbonate (CaCO3) precipitated from a calcium hydroxide (Ca(OH)2) suspensions and carbon dioxide gas (CO2) was studied by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The amorphous calcium carbonate, vaterite, aragonite and calcite were observed for the precipitated samples with organic additives. While the precipitation without organic additive, only the stable phase; calcite was obtained. The observed crystal phases were related with the alkyl chain length in the aliphatic part of additives. These results suggested that hydrophobic interactions due to the van der Waals force between organic additives and surface of inorganic precipitates could not be ignored. We concluded that covering or adsorbing of these organic additives on the precipitates surfaces retarded the successive dissolution/recrystallisation process in the aqueous systems. The results revealed that not only the polar interaction from the hydrophilic functional groups, as the former reports proposed, but also the van der Waals interactions from the hydrophobic alkyl groups played the important role in the phase transformation of CaCO3.

Chuajiw, Wittaya; Takatori, Kazumasa; Igarashi, Teruki; Hara, Hiroki; Fukushima, Yoshiaki

2014-01-01

198

Tetradecylthioacetic acid prevents high fat diet induced adiposity and insulin resistance  

Microsoft Academic Search

Tetradecylthioacetic acid (TTA) is a non- ? -oxi- dizable fatty acid analog, which potently regulates lipid ho- meostasis. Here we evaluate the ability of TTA to prevent diet-induced and genetically determined adiposity and insu- lin resistance. In Wistar rats fed a high fat diet, TTA admin- istration completely prevented diet-induced insulin resis- tance and adiposity. In genetically obese Zucker (fa\\/fa)

Lise Madsen; Michéle Guerre-Millo; Esben N. Flindt; Kjetil Berge; Karl Johan Tronstad; Elin Bergene; Elena Sebokova; Arild C. Rustan; Jørgen Jensen; Susanne Mandrup; Karsten Kristiansen; Iwar Klimes; Bart Staels; Rolf K. Berge

199

Modification of polyglutamic acid with silanol groups and calcium salts to induce calcification in a simulated body fluid.  

PubMed

The formation of hydroxyapatite is important for artificial materials to show high biological affinities for bone tissue. The present study focused on the synthesis of hydrogels capable of showing apatite formation, through modification of polyglutamic acid (PGA) with 3-aminopropyltriethoxysilane (APTES), followed by treatment with calcium chloride solution. A transparent bulk hydrogel was obtained at a molar ratio of PGA/APTES of 0.5. Prior soaking of the PGA hydrogel in calcium chloride solution accelerated the formation of bone-like apatite in a simulated body fluid. The modified PGA hydrogel is a candidate material for a biodegradable scaffold for bone regeneration. PMID:20207777

Koh, Mi-Young; Ohtsuki, Chikara; Miyazaki, Toshiki

2011-02-01

200

Prevention of sudden cardiac death by n?3 polyunsaturated fatty acids  

Microsoft Academic Search

This is a review of our present understanding of the mechanism by which the n?3 polyunsaturated fatty acids (PUFA) in fish oils prevent fatal ventricular arrhythmias in animals and cultured heart cells. A brief review of three clinical trials that suggest that these PUFAs prevent sudden cardiac death is also included in order to emphasize the potential importance of these

Alexander Leaf; Yong-Fu Xiao; Jing X. Kang; George E. Billman

2003-01-01

201

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...

202

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

203

LMO4 is essential for paraventricular hypothalamic neuronal activity and calcium channel expression to prevent hyperphagia.  

PubMed

The dramatic increase in the prevalence of obesity reflects a lack of progress in combating one of the most serious health problems of this century. Recent studies have improved our understanding of the appetitive network by focusing on the paraventricular hypothalamus (PVH), a key region responsible for the homeostatic balance of food intake. Here we show that mice with PVH-specific ablation of LIM domain only 4 (Lmo4) become rapidly obese when fed regular chow due to hyperphagia rather than to reduced energy expenditure. Brain slice recording of LMO4-deficient PVH neurons showed reduced basal cellular excitability together with reduced voltage-activated Ca(2+) currents. Real-time PCR quantification revealed that LMO4 regulates the expression of Ca(2+) channels (Cacna1h, Cacna1e) that underlie neuronal excitability. By increasing neuronal activity using designer receptors exclusively activated by designer drugs technology, we could suppress food intake of PVH-specific LMO4-deficient mice. Together, these results demonstrate that reduced neural activity in LMO4-deficient PVH neurons accounts for hyperphagia. Thus, maintaining PVH activity is important to prevent hyperphagia-induced obesity. PMID:24381275

Zaman, Tariq; Zhou, Xun; Pandey, Nihar R; Qin, Zhaohong; Keyhanian, Kianoosh; Wen, Kendall; Courtney, Ryan D; Stewart, Alexandre F R; Chen, Hsiao-Huei

2014-01-01

204

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

205

Wrought lead-calcium-tin alloys for tubular lead/acid battery grids  

NASA Astrophysics Data System (ADS)

Lead/acid batteries with tubular grids for the positive electrodes give flatter discharge curves and higher cycle life than batteries using flat plates. Most tubular grids for motive-power batteries contain 9-11 wt.% antimony. Recently, alloys with 1-6 wt.% antimony have been used for reduced maintenance batteries. Sealed, valve-regulated batteries with tubular positive grids for motive power, telecommunications, and UPS service are produced from cast lead-calcium-tin alloys. While these alloys permit the construction of such batteries, cast Pb?Ca?Sn alloys are significantly inferior to cast Pb?Sb alloys in mechanical properties. Wrought Pb?Ca?Sn alloys, when used for tubular grids, permit the application of maintenance-free alloys with mechanical properties comparable with, or higher than, those of high-antimony alloys. Wrought materials increase life due to the absence of casting defects. Wrought lead-calcium alloys also offer a dramatic improvement in creep and corrosion resistance compared with conventional cast, tubular, Pb?Ca?Sn alloys, as well as superior conductivity to cast Pb?Sb. Wrought Pb?Ca?Sn alloys permit the production of tubular grids at high speed in shapes and forms that are difficult to produce from cast materials. These grid shapes can lead to higher performance, higher discharge-rate, tubular plates. This paper discusses the mechanical properties, grain structure, and corrosion behaviour of cast and wrought Pb?Ca?Sn and Pb?Sb alloys for tubular grids. It also suggests manufacturing techniques for high performance, wrought, tubular plates.

Prengaman, R. David

206

Calcium dependence of the mechanical response evoked by okadaic acid in smooth muscle.  

PubMed

The effects of okadaic acid (OA), obtained from a culture of the marine dinoflagellate Prorocentrum lima were studied on isolated strips of rat myometrium. The contractile response evoked by OA at 5, 10, and 20 microM in normal physiological solution was unaffected in the presence of tetrodotoxin (10 microM), indomethacin (3 microM), or a cocktail of antagonists which blocked muscarinic, adrenergic, histaminergic, serotonergic, and opioid receptors. Similarly, the response to OA was unaffected in the presence of nifedipine at a concentration (1 microM) which completely or highly blocked the response to KCl (60 mM), oxytocin (1 microM), or acetylcholine (100 microM). In a Ca(2+)-free 1 mM EGTA-containing solution, the response to 10 and 20 microM OA was slightly but significantly reduced whereas the response to 5 microM OA was abolished. However, a response similar to that evoked in Ca(2+)-containing solution was observed when 5 microM OA was added to the bath in the presence of 1 microM oxytocin or 160 microM vanadate in a Ca(2+)-depleted solution with 1 mM EGTA. These data suggest that the response of rat myometrium to OA (> or = 5 microM) is not mediated through activation of membrane receptors or neurotransmitter release nor by cyclo-oxygenase products. The response to OA (10 and 20 microM) is highly resistant to the absence of calcium in the medium and does not seem to involve calcium entry through dihydropyridine-sensitive Ca2+ channels.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7700982

Arteche, E; Ausina, M P; Martin, J D; Norte, M; Advenier, C; Candenas, M L

1995-02-01

207

Molecular Dynamics Simulation on Scale Inhibition Mechanism of Polyepoxysuccinic Acid to Calcium Sulphate  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulation has been performed to simulate the interaction between PESA and the (001) face of anhydrite crystal CaSO4 at different temperatures with the presence of various number of H2O molecules. The results show that PESA can effectively prevent the growth of CaSO4 scale at 323-343 K. At the same temperature, the binding energy between PESA and the (001) face of CaSO4 for systems with various number of H2O has the order of Ebind(0H2O) > Ebind(200-400H2O) > Ebind(100H2O). For the same system at different temperatures the binding energies are close and are mainly contributed from the Coulomb interaction, including ionic bonds. The bonds are formed between the calcium atoms of anhydrite scale crystal and the oxygen atoms of the carboxyl group of PESA. Hydrogen bonds are formed between the O atoms of the carboxyl group of PESA and the H atoms of H2O. van der Waals interaction is conducive to the stability of the system of PESA, H2O, and CaSO4. The radial distribution functions of O(carbonyl of PESA)-H(H2O), O(CaSO4)-H(H2O), and O(CaSO4)-H(PESA) imply that solvents have effects on the anti-scale performance of PESA to CaSO4.

Zeng, Jian-ping; Wang, Feng-he; Zhou, Chen; Gong, Xue-dong

2012-04-01

208

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

209

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

210

The combination of 1?,25(OH) 2–vitamin D 3, calcium and acetylsalicylic acid affects azoxymethane-induced aberrant crypt foci and colorectal tumours in rats  

Microsoft Academic Search

Effects of 1?,25(OH)2–vitamin D3 and acetylsalicylic acid at various dietary levels of calcium (CaCO3) on development of aberrant crypt foci (ACF) and tumours in colon were examined in groups of 16 male F344 rats initiated with azoxymethane and observed for 16 weeks. Calcium was the most potent modulator of ACF development. The total number of ACF increased with low calcium

Anne-Marie Mølck; Morten Poulsen; Otto Meyer

2002-01-01

211

The effect of calcium salts, ascorbic acid and peptic pH on calcium, zinc and iron bioavailabilities from fortified human milk using an in vitro digestion/Caco-2 cell model.  

PubMed

The calcium, zinc, and iron bioavailabilities of human milk with commercial and noncommercial human milk fortifiers (HMFs) were evaluated under a variety of conditions: peptic digestion at pH 2 and pH 4, supplementation of ascorbic acid, and addition of three calcium salts. The noncommercial HMFs consisted of casein phosphopeptides (CPPs), alpha-lactalbumin, colostrum, and hydrolyzed whey protein concentrate (WPC). They were mixed with human milk (HM) and calcium, zinc, and iron were added. Ascorbic acid (AA) was added in certain studies. The commercial HMFs were Nestlé FM-85, Similac HMF (SHMF), and Enfamil HMF (EHMF). All HMFs were compared to S-26/SMA HMF. Results showed that the peptic pH (2 vs. 4) had no effect on mineral bioavailability. Addition of different calcium salts had no effect on calcium cell uptake and cell ferritin levels (an indicator of iron uptake), however, the addition of calcium glycerophosphate/gluconate increased zinc uptake by Caco-2 cells. Addition of AA significantly increased ferritin levels, with no effect on calcium or zinc uptake. Among the commercial HMFs, FM-85 was significantly lower in zinc uptake than S-26/SMA, and HM+EHMF was significantly higher than HM+S-26/SMA. Cell ferritin levels were significantly higher for HM+S-26/SMA than for all other commercial fortifiers. None of the commercial HMFs were different from HM+S-26/SMA in calcium uptake. PMID:16028632

Etcheverry, Paz; Wallingford, John Charles; Miller, Dennis Dean; Glahn, Raymond Philip

2005-05-01

212

Therapeutic efficiency of succimer used with calcium and ascorbic acid in the treatment of mild lead-poisoning.  

PubMed

The aim of this study was to explore therapeutic efficiency of succimer used with calcium and ascorbic acid in the treatment of mildly lead-poisoned mice and preschool children. Mice were exposed to lead by drinking water, and then treated with saline solution, 50mg/kg body weight (b.w.) succimer, 100mg/kg b.w. succimer, or 50mg/kg b.w. succimer plus calcium and ascorbic acid by gavage. Seventy-two children aged 48-72 months were randomly assigned into combined treatment or nutritional intervention group. Lead levels in blood and bone were analyzed by atomic absorption spectrophotometry. Activities of aminolevulinic acid dehydratase (ALAD) in blood were determined by colorimetric method. Results of animal experiment showed that succimer used alone could reduce lead levels in blood and bone and reverse activities of ALAD in blood, however, a better therapeutic efficiency in mobilizing bone lead could be achieved by succimer used with calcium and ascorbic acid. Findings from the clinical study showed that reduction of blood lead levels (BLLs) between the end and initiation of therapy in the combined treatment group was significantly greater than that in the nutritional intervention group. Percentage of children with BLLs less than 10?g/dL at the end of therapy and the eighth week after therapy in the combined treatment group was significantly higher than that in the nutritional intervention group. In conclusion, combined use of succimer with calcium and ascorbic acid seemed to be a choice in the treatment of mildly lead poisoned children. PMID:21787678

Jin, Yaping; Yu, Fei; Liao, Yingjun; Liu, Shaoxia; Liu, Meimei; Xu, Jianhong; Yang, Jun

2011-01-01

213

Benidipine, a Long-Acting Calcium-Channel Blocker, Prevents the Progression to End-Stage Renal Failure in a Rat Mesangioproliferative Glomerulonephritis  

Microsoft Academic Search

Background: Although the renoprotective effect of calcium-channel blockers (CCBs) has been examined in several models of hypertensive nephropathy, it remains unclear. It also remains to be clarified whether CCBs prevent the progression to end-stage renal failure in chronic progressive glomerulonephritis (GN). A new rat model of progressive mesangioproliferative GN was used to study the effect of benidipine hydrochloride, a long-acting

Takamichi Nakamura; Jun-ei Obata; Makoto Onitsuka; Yuji Shimada; Yoji Yoshida; Hiroshi Kawachi; Fujio Shimizu

2000-01-01

214

Membrane Effects of the n-3 Fish Oil Fatty Acids, which Prevent Fatal Ventricular Arrhythmias  

Microsoft Academic Search

Fish oil fatty acids are known to exert beneficial effects on the heart and vascular systems. We have studied the membrane\\u000a effects on ion channel conductance by the n-3 fish oil fatty acids that account for these beneficial effects. We have confirmed\\u000a that these fatty acids prevent fatal cardiac arrhythmias in a reliable dog model of sudden cardiac death. This

A. Leaf; Y.-F. Xiao; J. X. Kang; G. E. Billman

2005-01-01

215

Omega-3 Fatty Acid Supplementation to Prevent Recurrent Preterm Birth  

PubMed Central

OBJECTIVE To assess whether the addition of an omega-3 long-chain polyunsaturated fatty acid supplement would reduce preterm birth in women with at least one prior spontaneous preterm birth receiving 17?-hydroxyprogesterone caproate. METHODS We conducted a randomized, double-masked, placebo-controlled trial in 13 centers. Women with a history of prior spontaneous singleton preterm birth and a current singleton gestation were assigned to either a daily omega-3 supplement (1,200 mg eicosapentaenoic acid and 800 mg docosahexaenoic acid) or matching placebo from 16–22 through 36 weeks of gestation. All participants received weekly intramuscular 17?-hydroxyprogesterone caproate (250 mg). The primary study outcome was delivery before 37 weeks of gestation. A sample size of 800 was necessary to have 80% power to detect a 30% reduction in the primary outcome from 30%, assuming a type I error two-sided of 5%. RESULTS A total of 852 women were included, and none was lost to follow up. Delivery before 37 weeks of gestation occurred in 37.8% (164/434) of women in the omega-3 group and 41.6% (174/418) in the placebo group (relative risk 0.91, 95% confidence interval 0.77–1.07). CONCLUSION Omega-3 long-chain polyunsaturated fatty acid supplementation offered no benefit in reducing preterm birth among women receiving 17?-hydroxyprogesterone caproate who have a history of preterm delivery.

Harper, Margaret; Thom, Elizabeth; Klebanoff, Mark A.; Thorp, John; Sorokin, Yoram; Varner, Michael W.; Wapner, Ronald J.; Caritis, Steve N.; Iams, Jay D.; Carpenter, Marshall W.; Peaceman, Alan M.; Mercer, Brian M.; Sciscione, Anthony; Rouse, Dwight J.; Ramin, Susan M.; Anderson, Garland D.

2014-01-01

216

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

217

Determination of calcium oxalate (mono- and dihydrate) in mixtures with magnesium ammonium phosphate or uric acid: the use of simultaneous thermal analysis in urinary calculi  

Microsoft Academic Search

Background: The human urinary calculi are mainly formed from calcium oxalate, magnesium ammonium phosphate hexahydrate (MAPH) and uric acid (UA) crystals. It is important for the physician and surgeon to distinguish the two types of hydrates of calcium oxalate, mainly mono- (COM, Whewellite) and dihydrate (COD, Weddelite). This is because COM stones are evacuated two times more frequently than COD,

Jacques Kaloustian; Tarek F. El-Moselhy; Henri Portugal

2003-01-01

218

Induction of bovine bronchial epithelial cell filopodia by tetradecanoyl phorbol acetate, calcium ionophore, and lysophosphatidic acid.  

PubMed

The morphological responses of primary bovine bronchial epithelial cells (BBECs) cultured in serum-free medium to protein activators have been examined. When attached to type I collagen-coated tissue culture dishes, the cells responded to tetradecanoyl phorbol acetate (TPA), calcium ionophore A23187, and lysophosphatidic acid (LPA) by extruding filopodia. In contrast, no morphological changes were elicited by exposures to either epinephrine or dibutyryl-cAMP. Formation of filopodia was accompanied by actin filament reorganization as demonstrated by staining with labeled phalloidin. Exposures to varied TPA concentrations for 2 h showed maximal stimulation of filopodial extrusions at 10 nM TPA with half-maximal stimulation at 1 nM. Time-course measurements with 10 nM TPA showed filopodia formation within 30 min of exposure, with 85% of the BBECs being filopodia positive after 5 h. Filopodia induction in 20-30% of the cells could be achieved by 1-100 microM LPA concentrations. BBECs acquired increasing resistance to TPA-induced filopodia during the initial 5 days in culture; however, responsiveness to TPA was regenerated by mild treatment with trypsin. Inclusion of fibronectin or vitronectin into the attachment matrix had no effects on the rates or extent of TPA-induced filopodia formation. PMID:7540618

Beckmann, J D; Romberger, D J; Rennard, S I; Spurzem, J R

1995-07-01

219

Salicylic acid and calcium-induced protection of wheat against salinity.  

PubMed

Soil salinity is one of the important environmental factors that produce serious agricultural problems. The objective of the present study was to determine the interactive effect of salicylic acid (SA) and calcium (Ca) on plant growth, photosynthetic pigments, proline (Pro) concentration, carbonic anhydrase (CA) activity and activities of antioxidant enzymes of Triticum aestivum L. (cv. Samma) under salt stress. Application of 90 mM of NaCl reduced plant growth (plant height, fresh weight (FW) and dry weight (DW), chlorophyll (Chl) a, Chl b, CA activity) and enhanced malondialdehyde (MDA) and Pro concentration. However, the application of SA or Ca alone as well as in combination markedly improved plant growth, photosynthetic pigments, Pro concentration, CA activity and activities of antioxidant enzymes peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR) and ascorbate peroxidase (APX) under salt stress. It was, therefore, concluded that application of SA and Ca alone as well as in combination ameliorated the adverse effect of salinity, while combined application proved more effective to reduce the oxidative stress generated by NaCl through reduced MDA accumulation, Chl a/b ratio and Chls degradation and enhanced activities of antioxidant enzymes. PMID:21979309

Al-Whaibi, Mohamed H; Siddiqui, Manzer H; Basalah, Mohammed O

2012-07-01

220

Bilayer tablets of atorvastatin calcium and nicotinic acid: formulation and evaluation.  

PubMed

The objective of the study is to formulate bilayer tablets consisting of atorvastatin calcium (AT) as an immediate release layer and nicotinic acid (NA) as an extended release layer. The immediate release layer was prepared using super disintegrant croscarmellose sodium and extended release layer using hydroxypropylmethyl cellulose (HPMC K100M). Both the matrix and bilayer tablets were evaluated for hardness, friability, weight variation, thickness, and drug content uniformity and subjected to in vitro drug release studies. The amount of AT and NA released at different time intervals were estimated by HPLC method. The bilayer tablets showed no significant change either in physical appearance, drug content or in dissolution pattern after storing at 40 degrees C/75% relative humiding (RH) for 3 months. The release of the drug from the tablet was influenced by the polymer content and it was much evident from thermogravimetry/differential thermal analysis (TG/DTA) analysis. The results indicated that the bilayer tablets could be a potential dosage form for delivering AT and NA. PMID:18827389

Nirmal, Jayabalan; Saisivam, Srinivasan; Peddanna, Chintalapati; Muralidharan, Selvadurai; Godwinkumar, Sundaram; Nagarajan, Muthuraja

2008-10-01

221

Degradable biocomposite of nano calcium-deficient hydroxyapatite-multi(amino acid) copolymer  

PubMed Central

Background and methods A nano calcium-deficient hydroxyapatite (n-CDHA)-multi(amino acid) copolymer (MAC) composite bone substitute biomaterial was prepared using an in situ polymerization method. The composition, structure, and compressive strength of the composite was characterized, and the in vitro degradability in phosphate-buffered solution and preliminary cell responses to the composite were investigated. Results The composite comprised n-CDHA and an amide linkage copolymer. The compressive strength of the composite was in the range of 88–129 MPa, varying with the amount of n-CDHA in the MAC (ranging from 10 wt% to 50 wt%). Weight loss from the composite increased (from 32.2 wt% to 44.3 wt%) with increasing n-CDHA content (from 10 wt% to 40 wt%) in the MAC after the composite was soaked in phosphate-buffered solution for 12 weeks. The pH of the soaking medium varied from 6.9 to 7.5. MG-63 cells with an osteogenic phenotype were well adhered and spread on the composite surface. Viability and differentiation increased with time, indicating that the composite had no negative effects on MG-63 cells. Conclusion The n-CDHA-MAC composite had good cytocompatibility and has potential to be used as a bone substitute.

Li, Hong; Gong, Min; Yang, Aiping; Ma, Jian; Li, Xiangde; Yan, Yonggang

2012-01-01

222

The effect of phosphoric acid concentration on the synthesis of nano-whiskers of calcium metaphosphate by chemical precipitation Method  

NASA Astrophysics Data System (ADS)

Calcium metaphosphate (CMP) nano-whiskers were produced by a chemical precipitation method. In order to produce nano-powders, CMP was prepared by the mixing of two precursors, calcium oxide (CaO) and phosphate acid (H3PO4). Sparingly soluble chemicals, the Ca/P ratio of the mixture was set to be 0.50 to produce stoichiometric CMP, were chemical agitated in phosphate acid solution. At least 3 hours of pre-hydrolysis of phosphorus precursor were required to obtain CMP phase. The CMP powders were dried in a drying oven at 60 °C for 7 days and then followed by a heat treatment at 390 °C for 8hours. The obtained powder was analyzed using XRD, XRF, FT-IR, SEM, TG-DTA, Zeta Potential Meter, Specific Surface Area, and Particle Size Analyzer. The results showed that obtained CMP nano-whiskers have a significantly powder characteristics.

Yao, Nengjian; Zhang, Yin; Kong, Deshuang; Zhu, Jianping; Tao, Yaqiu; Qiu, Tai

2011-10-01

223

Conjugated linoleic acid (CLA) prevents age associated skeletal muscle loss  

PubMed Central

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 6 months. Both t10c12-CLA and CLA-mix groups showed significantly higher muscle mass, as compared to CO and c9t11-CLA groups, measured by dual-energy-Xray-absorptiometry and muscle wet weight. Enhanced mitochondrial ATP production, with higher membrane potential, and elevated muscle antioxidant enzymes (catalase and glutathione peroxidase) production, accompanied by slight increase in H2O2 production was noted in t10c12-CLA and CLA-mix groups, as compared to that of CO and c9t11-CLA groups. Oxidative stress, as measured by serum malondialdehyde and inflammation, as measured by LPS-treated splenocyte IL-6 and TNF-alpha, were significantly less in CLA isomers groups. Thus, CLA may be a novel dietary supplement that will prevent sarcopenia by maintaining redox balance during aging.

Rahman, Md M; Halade, Ganesh V; Jamali, Amina El; Fernandes, Gabriel

2010-01-01

224

Deltamethrin Lethal Multifactorial Activity toward Carp Larva Related to pH, Calcium, and Humic Acid Concentrations  

Microsoft Academic Search

Acute 24-hr embryotoxicity of the pyrethroid insecticide deltamethrin toward carp larvae was tested in multifactorial combinations of three pHs (6.9, 7.8, 9.0), two calcium concentrations ([Ca] = 2 × 10?4and 2 × 10?2M), and three humic acids concentrations ([HA] = 0, 5, and 100 mg\\/liter). Lethal effects were determined and compared to the distribution and hexane extractibility of radiolabeled deltamethrin

François Ghillebaert; Didier Prodorutti; Catherine Chaillou; Pierre Roubaud

1996-01-01

225

Population based data on urinary excretion of calcium, magnesium, oxatate, phosphate and uric acid in children from Cimitile (southern Italy)  

Microsoft Academic Search

Population based data on 24-h urinary excretion of calcium, oxalate, magnesium, phosphate, uric acid and creatinine were collected from 220 children (aged 3–16 years) living in Cimitile, Campania, southern Italy. Mean excretion rates for 7 days were correlated with age, body weight, body mass index and height. The prevalence of hypercalciuria (>4 mg\\/kg body weight) and of hyperoxaluria (>60 mg\\/day)

Natale G. De Santot; Biagio Di Iorio; Giovambattista Capasso; Carmine Paduanol; Rose Stamler; Craig B. Langman; Jeremiah Stamler

1992-01-01

226

Uric acid and xanthine oxidase: future therapeutic targets in the prevention of cardiovascular disease?  

PubMed Central

Serum uric acid may be an independent risk factor for cardiovascular disease. This review examines this association, potential mechanisms, and explores whether strategies to reduce uric acid will improve outcomes. The recent studies of xanthine oxidase inhibition are given particular focus. Epidemiological evidence supports the theory that uric acid is an independent risk factor for cardiovascular disease. Recent studies of losartan, atorvastatin and fenofibrate suggest that uric acid reduction contributes to the risk reduction offered by these therapies. Several small studies of xanthine oxidase inhibition have shown improvements in measures of cardiovascular function of a similar magnitude to that of other proven preventative treatments. These trial data and the convincing epidemiological evidence mandate that large clinical trials of uric acid-lowering strategies are performed in patients with or at high risk of cardiovascular disease. If such approaches are shown to be effective in reducing cardiovascular events, they would represent a novel and cost-effective preventative approach.

Dawson, Jesse; Walters, Matthew

2006-01-01

227

Evaluation of the Health Aspects of Citric Acid, Sodium Citrate, Potassium Citrate, Calcium Citrate, Ammonium Citrate, Triethyl Citrate, Isopropyl Citrate, and Stearyl Citrate as Food Ingredients.  

National Technical Information Service (NTIS)

The report, by a group of qualified scientists designated the Select Committee on GRAS Substances (SCOGS), provides an independent evaluation of the safety of citric acid, sodium citrate, potassium citrate, calcium citrate, ammonium citrate, triethyl citr...

1977-01-01

228

Unsaturated Fatty Acids Induce Calcium Influx into Keratinocytes and Cause Abnormal Differentiation of Epidermis  

Microsoft Academic Search

Abnormal follicular keratinization is involved in comedogenesis in acne vulgaris. We recently demonstrated that calcium influx into epidermal keratinocytes is associated with impaired skin barrier function and epidermal proliferation. Based on these results, we hypothesized that sebum components affect calcium dynamics in the keratinocyte and consequently induce abnormal keratinization. To test this idea, we first observed the effects of topical

Yuji Katsuta; Toshii Iida; Shinji Inomata; Mitsuhiro Denda

2005-01-01

229

Retinoic acid regulates the expression of the calcium binding protein, calbindin-D28K.  

PubMed

It is a well established fact that the calcium-binding protein, calbindin-D28k, is influenced by vitamin D in intestine and kidney. However, very little is known concerning the regulation of calbindin-D28k in brain. Although few genes that are regulated by retinoic acid (RA) have been identified in the nervous system, we now report that the human medulloblastoma cell line D283 (which is derived from cerebellum and has a distinctly neuronal phenotype) contains calbindin-D28k endogenously and that calbindin protein and mRNA can be induced 10- to 15-fold in these cells by 10(-7) M RA. These findings are the first evidence of RA-mediated regulation of calbindin. The time course of response, as determined by Northern blot analysis, indicated that the first significant increase in calbindin-D28k mRNA is at 12 h with a plateau of calbindin mRNA induction at 72 h after RA treatment. The induction of calbindin mRNA by RA was preceded by an induction of retinoic acid receptor-alpha mRNA and was accompanied by an induction of retinoid X receptor-alpha mRNA. Calbindin-D28k mRNA levels in D283 medulloblastoma cells as well as the induction of calbindin mRNA by RA were not significantly affected by 1,25-dihydroxyvitamin D3 treatment. Deletion mutant analysis of the native calbindin-D28k promoter and cotransfection of CV-1 or D283 medulloblastoma cells in the presence of retinoic acid receptor-alpha and/or retinoid X receptor-alpha expression vectors as well as results of nuclear transcription assays did not indicate transcriptional regulation of calbindin-D28k by RA. Studies of calbindin-D28k mRNA in control and RA-pretreated D283 medulloblastoma cells at various times (3-24 h) after treatment with 4 micrograms/ml actinomycin D indicated that the half-life of calbindin-D28k mRNA was significantly increased in the presence of RA, suggesting regulation of calbindin-D28k mRNA stability by RA. Thus, calbindin-D28k is one of the few known targets of RA action in cells that express a neuronal phenotype. In addition, our findings present further evidence of an interrelationship between the actions of 1,25-dihydroxyvitamin D3 and the active metabolites of vitamin A. PMID:8584029

Wang, Y Z; Christakos, S

1995-11-01

230

Meta-analysis of the quantity of calcium excretion associated with the net acid excretion of the modern diet under the acid-ash diet  

Microsoft Academic Search

Background:Theacid-ashdiethypothesisofosteoporosissuggests that acid from the modern diet causes a demineralization of the skeleton, and mobilized bone calcium is excreted. A systematic approachhasnotbeenusedtosummarizethefindingsofthenumer- ous studies about the hypothesis. Objectives: The purpose of this meta-analysis was to estimate the quantityofnetacidexcretionandcalciuriaassociatedwiththemod- erndiet,toassesstheassociationbetweenacidexcretionandcalcium excretion, and to assess the influence of urine preservatives on cal- cium measurement. Design: We systematically searched for trials of the

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

231

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

232

The role of calcium channel blockers and resveratrol in the prevention of paraquat-induced parkinsonism in Drosophila melanogaster: a locomotor analysis.  

PubMed

Studies have suggested that neuronal loss in Parkinson's disease (PD) could be related to the pacemaker activity of the substantia nigra pars compacta generated by L-type Ca(v) 1.3 calcium channels, which progressively substitute voltage-dependent sodium channels in this region during aging. Besides this mechanism, which leads to increases in intracellular calcium, other factors are also known to play a role in dopaminergic cell death due to overproduction of reactive oxygen species. Thus, dihydropyridines, a class of calcium channel blockers, and resveratrol, a polyphenol that presents antioxidant properties, may represent therapeutic alternatives for the prevention of PD. In the present study, we tested the effects of the dihydropyridines, isradipine, nifedipine, and nimodipine and of resveratrol upon locomotor behavior in Drosophila melanogaster. As previously described, paraquat induced parkinsonian-like motor deficits. Moreover, none of the drugs tested were able to prevent the motor deficits produced by paraquat. Additionally, isradipine, nifedipine, resveratrol, and ethanol (vehicle), when used in isolation, induced motor deficits in flies. This study is the first demonstration that dyhidropyridines and resveratrol are unable to reverse the locomotor impairments induced by paraquat in Drosophila melanogaster. PMID:21523449

Bagatini, Pamela Brambilla; Saur, Lisiani; Rodrigues, Mariana Freitas; Bernardino, Guilherme Cardoso; Paim, Mariana Fontoura; Coelho, Guilherme Peres; Silva, Daniele Vieira da; de Oliveira, Raquel Mattos; Schirmer, Helena; Souto, André Arigony; Vianna, Mônica Ryff Moreira Roca; Xavier, Léder Leal

2011-06-01

233

Acute exercise increases triglyceride synthesis in skeletal muscle and prevents fatty acid-induced insulin resistance  

PubMed Central

Fatty acid oversupply is a key mediator of skeletal muscle insulin resistance in obesity, primarily via accumulation of fatty acid metabolites and activation of proinflammatory pathways. Herein, we demonstrate that fatty acid–induced insulin resistance in humans is completely prevented the day after 1 session of endurance exercise. Because skeletal muscle is the primary site for systemic glucose disposal and is highly susceptible to impaired insulin action by elevated fatty acid availability, we obtained skeletal muscle samples to investigate possible mechanisms mediating this protective effect of exercise. Prevention of fatty acid–induced insulin resistance after exercise accompanied enhanced skeletal muscle protein expression of key lipogenic enzymes and an increase in muscle triglyceride synthesis. Partitioning more fatty acids toward triglyceride synthesis within muscle reduced the accumulation of fatty acid metabolites and suppressed the proinflammatory response in skeletal muscle, as evidenced by decreased phosphorylation and activation of JNK and increased abundance of inhibitor of NF-?B ? (I?B-?) and I?B-?. We believe this is the first study to demonstrate that 1 session of exercise completely reverses fatty acid–induced insulin resistance in humans. Reversal of insulin resistance accompanied enhanced lipogenic capacity within skeletal muscle, reduced accumulation of highly bioactive fatty acid metabolites, and suppressed activation of proinflammatory pathways known to impair insulin action.

Schenk, Simon; Horowitz, Jeffrey F.

2007-01-01

234

Effect of uncoated calcium carbonate and stearic acid coated calcium carbonate on mechanical, thermal and structural properties of poly(butylene terephthalate) (PBT)\\/calcium carbonate composites  

Microsoft Academic Search

PBT\\/CaCO3 composites were prepared in a single screw extruder with particle content varying from 0–30% by weight. The influence of\\u000a surface treatment of the particles, with and without stearic acid (SA), on the mechanical, thermal and structural properties\\u000a was studied. The experiments included tensile tests, impact tests, differential scanning calorimetry (DSC), scanning electron\\u000a microscopy (SEM), X-ray diffraction (XRD) and Fourier

G. S. Deshmukh; S. U. Pathak; D. R. Peshwe; J. D. Ekhe

2010-01-01

235

The curative effect of zoledronic acid and pamidronic acid on treating ostealgia in malignant tumor with bone metastases and its side effects on serum calcium and phosphorus  

Microsoft Academic Search

Objective  Bisphosphonates were widely used with the rate of malignant tumor with bone metastases increasing rapidly. The aim of this\\u000a study was to evaluate zoledronic acid and pamidronic acid on treating ostealgia of malignant tumor with bone metastases and\\u000a serum calcium, phosphorus and alkaline phosphorus movement.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  One Hundred cancer patients with bone metastases were diagnosed according to pathological and imaging methods.

Yuedi Dai; Meixing Wang; Li Tao; Anqi Li; Haixia Wu; Mi Xiao

2011-01-01

236

Improved grid alloys for deep-cycling lead?calcium batteries  

NASA Astrophysics Data System (ADS)

Lead?calcium standby batteries contain free acid, thick grids of low calcium content, and are discharged infrequently. Valve-regulated lead/acid batteries (VRLAs) are deeply discharged, contain immobilized electrolyte, and contain much thinner grids of lead?calcium?tin alloys. Tin is added to enhance rechargeability from deep discharge and to enhance the mechanical properties of the alloys, particularly creep resistance. Until 1980, lead?calcium?tin alloys suffered from wide variations in grain structure, caused mainly by poor control of the calcium content. The latter is due to calcium oxidation and the inclusion of suspended oxide into the grids. The introduction of aluminium into lead?calcium and lead?calcium?tin?aluminium alloys prevents calcium loss from the melt. Lead?calcium?tin?aluminium alloys can be produced to the desired specification without fear of either calcium loss or poor control of grain structure. Aluminium also serves both as a nucleant to significantly reduce the initial cast grain-structure and as a means to enhance the precipitation of calcium in lead?calcium?tin alloys. Grain-structure control is now possible even in very high tin-content alloys. Lead?calcium?tin alloys with aluminium are not susceptible to penetrating grain boundary corrosion and will become the favored alloys for deep-cycling VRLAs of the future.

David Prengaman, R.

237

Dehydroeburicoic acid induces calcium- and calpain-dependent necrosis in human U87MG glioblastomas.  

PubMed

Dehydroeburicoic acid (DeEA) is a triterpene purified from medicinal fungi such as Antrodia camphorate, the crude extract of which is known to exert cytotoxic effects against several types of cancer cells. We aim to test the hypothesis that DeEA possesses significant cytotoxic effects against glioblastomas, one of the most frequent and malignant brain tumors in adults. 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase release assays indicated that DeEA inhibited the proliferation of the human glioblastoma cell U87MG. In addition, Annexin V and propidium iodide staining showed that DeEA treatment led to a rapid increase of glioblastomas in the necrotic/late apoptotic fraction, whereas cell cycle analysis revealed that DeEA failed to significantly enhance the population of U87MG cells in the hypodiploid (sub-G1) fraction. Using electron microscopy, we found that DeEA induced significant cell enlargements, massive cytoplasmic vacuolization, and loss of mitochondrial membrane integrity. DeEA treatment triggered an intracellular Ca(2+) increase, and DeEA-induced cell death was significantly attenuated by BAPTA-AM but not ethylenediaminetetraacetic acid or ethylene glycol tetraacetic acid. DeEA instigated a reduction of both mitochondrial transmembrane potential and intracellular ATP level. Moreover, DeEA induced proteolysis of alpha-spectrin by calpain, and DeEA cytotoxicity in U87MG cells was caspase-independent but was effectively blocked by calpain inhibitor. Interestingly, DeEA also caused autophagic response that was prevented by calpain inhibitor. Taken together, these results suggest that in human glioblastomas, DeEA induces necrotic cell death that involves Ca(2+) overload, mitochondrial dysfunction, and calpain activation. PMID:19848398

Deng, Jhu-Yun; Chen, Sian-Jin; Jow, Guey-Mei; Hsueh, Chao-Wen; Jeng, Chung-Jiuan

2009-11-01

238

Efficacy of a novel calcium/potassium salt of (-)-hydroxycitric acid in weight control.  

PubMed

The weight-loss efficacy of a novel, water-soluble, calcium-potassium salt of (-)-hydroxycitric acid (HCA-SX) was re-examined in 90 obese subjects (BMI: 30-50.8 kg/m2). We combined data from two previously reported randomized, double-blind, placebo-controlled clinical studies in order to achieve a better statistical evaluation based on a larger population. This re-examination of data also allowed us to reflect more intensely on various aspects of weight loss studies. Subjects were randomly divided into three groups: group A received a daily dose of HCA-SX 4, 667 mg (providing 2,800 mg HCA per day); group B was given a daily dose of a combination of HCA-SX 4,667 mg, niacin-bound chromium (NBC) 4 mg (providing 400 microg elemental chromium), and Gymnema sylvestre extract (GSE) 400 mg (providing 100 mg gymnemic acid); and group C received a placebo in three equally divided doses 30-60 min before each meal. All subjects were provided a 2,000 kcal diet/day and participated in a supervised walking program for 30 min/day, 5 days/week. Eighty-two subjects completed the study. At the end of 8 weeks, in group A, both body weight and BMI decreased by 5.4%, low-density lipoprotein and triglycerides levels were reduced by 12.9% and 6.9%, respectively, while high-density lipoprotein levels increased by 8.9%, serum leptin levels decreased by 38%, serotonin levels increased by 44.5% and urinary excretion of fat metabolites increased by 32-109%. Group B demonstrated similar beneficial changes, but generally to a greater extent. No significant adverse effects were observed. The combined results confirm that HCA-SX and, to a greater degree, the combination of HCA-SX plus NBC and GSE reduce body weight and BMI, suppress appetite, improve blood lipid profiles, increase serum leptin and serotonin levels and increase fat oxidation more than placebo. We conclude that dosage levels, timing of administration, subject compliance and bioavailability of HCA-SX significantly affect results and that when taken as directed, HCA-SX is a highly effective adjunct to healthy weight control. PMID:16366421

Preuss, H G; Garis, R I; Bramble, J D; Bagchi, D; Bagchi, M; Rao, C V S; Satyanarayana, S

2005-01-01

239

?-Lipoic acid and ascorbate prevent LDL oxidation and oxidant stress in endothelial cells  

Microsoft Academic Search

Both ?-lipoic acid (LA) and ascorbic acid (vitamin C) have been shown to improve endothelial dysfunction, a precursor of atherosclerosis.\\u000a Since oxidant stress can cause endothelial dysfunction, we tested the interaction and efficacy of these antioxidants in preventing\\u000a oxidant damage to lipids due to both intra- and extracellular oxidant stresses in EA.hy926 endothelial cells. LA spared intracellular\\u000a ascorbate in culture

Anup K. Sabharwal; James M. May

2008-01-01

240

Prevention of ischemia-induced ventricular fibrillation by omega 3 fatty acids.  

PubMed Central

A specially prepared dog model of myocardial infarction was used to test the efficacy of the long-chain polyunsaturated fish oil omega 3 fatty acids eicosapentaenoic (20:5 n-3) and docosahexaenoic (22:6 n-3) acids to prevent ischemia-induced malignant cardiac arrhythmias. The dogs had sustained a prior experimental myocardial infarction from ligation of the left anterior descending coronary artery, and a hydraulic cuff was implanted around the left circumflex artery at that operation. After recovery from that procedure the animals were tested during a treadmill exercise test. With compression of the left circumflex artery sensitive animals will predictably develop ventricular fibrillation (VF). In such prepared dogs an emulsion of fish oil fatty acids was infused i.v. over a 50- to 60-min period just before the exercise-plus-ischemia test, and the effect on development of VF was recorded. The infusion was 100 ml of a 10% (vol/vol) emulsion of a fish oil concentrate containing 70% omega 3 fatty acids with free eicosapentaenoic acid and docosahexaenoic acid composing 33.9% and 25.0% of that total, respectively. Alternatively, some animals similarly received an emulsion containing 5 ml of the free fatty acid concentrate plus 5 ml of a triacylglyerol concentrate containing 65% omega 3 fatty acids with eicosapentaenoic acid and docosahexaenoic acid composing 34.0% and 23.6% of that total, respectively. In seven of eight animals the infusion of the fish oil emulsion completely prevented the acute occurrence of VF in the susceptible animals (P < 0.005). In five of five of these animals the subsequent exercise-plus-ischemia test after a similar infusion of an emulsion in which soy bean oil replaced the fish oil fatty acid concentrates resulted in prompt development of VF. Possible mechanisms for this protective effect of omega 3 fatty acids against exercise and ischemia-induced malignant arrhythmias are considered.

Billman, G E; Hallaq, H; Leaf, A

1994-01-01

241

Knowledge about folic acid and the prevention of neural tube defects in two general practice populations.  

PubMed Central

Knowledge about the link between folic acid supplementation in pregnancy and the prevention of neural tube defects was assessed in women from two contrasting general practices using a questionnaire. The persisting lack of awareness, particularly in the more at-risk group from the inner city area, lends support to the argument in favour of the fortification of flour.

Krischer, J

1997-01-01

242

Phase III Trial of Ursodeoxycholic Acid To Prevent Colorectal Adenoma Recurrence  

Microsoft Academic Search

Background: Ursodeoxycholic acid (UDCA) treatment is associated with a reduced incidence of colonic neoplasia in preclinical models and in patients with conditions associated with an increased risk for colon cancer. We conducted a phase III, double-blind placebo-controlled trial of UDCA to evalu- ate its ability to prevent colorectal adenoma recurrence. Methods: We randomly assigned 1285 individuals who had undergone removal

David S. Alberts; María Elena Martínez; Lisa M. Hess; Janine G. Einspahr; Sylvan B. Green; A. K. Bhattacharyya; Jose Guillen; Mary Krutzsch; Ashok K. Batta; Gerald Salen; Liane Fales; Kris Koonce; Dianne Parish; Mary Clouser; Denise Roe; Peter Lance

243

21 CFR 172.844 - Calcium stearoyl-2-lactylate.  

Code of Federal Regulations, 2013 CFR

...additive, which is a mixture of calcium salts of stearoyl lactylic acids and minor proportions of other calcium salts of related acids, is manufactured by the reaction of stearic acid and lactic acid and conversion to the calcium salts....

2013-04-01

244

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.

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

2011-01-01

245

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.

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

246

Nucleotide precursors prevent folic acid-resistant neural tube defects in the mouse.  

PubMed

Closure of the neural tube during embryogenesis is a crucial step in development of the central nervous system. Failure of this process results in neural tube defects, including spina bifida and anencephaly, which are among the most common birth defects worldwide. Maternal use of folic acid supplements reduces risk of neural tube defects but a proportion of cases are not preventable. Folic acid is thought to act through folate one-carbon metabolism, which transfers one-carbon units for methylation reactions and nucleotide biosynthesis. Hence suboptimal performance of the intervening reactions could limit the efficacy of folic acid. We hypothesized that direct supplementation with nucleotides, downstream of folate metabolism, has the potential to support neural tube closure. Therefore, in a mouse model that exhibits folic acid-resistant neural tube defects, we tested the effect of specific combinations of pyrimidine and purine nucleotide precursors and observed a significant protective effect. Labelling in whole embryo culture showed that nucleotides are taken up by the neurulating embryo and incorporated into genomic DNA. Furthermore, the mitotic index was elevated in neural folds and hindgut of treated embryos, consistent with a proposed mechanism of neural tube defect prevention through stimulation of cellular proliferation. These findings may provide an impetus for future investigations of supplemental nucleotides as a means to prevent a greater proportion of human neural tube defects than can be achieved by folic acid alone. PMID:23935126

Leung, Kit-Yi; De Castro, Sandra C P; Savery, Dawn; Copp, Andrew J; Greene, Nicholas D E

2013-09-01

247

Acidic Amino Acids in the First Intracellular Loop Contribute to Voltage- and Calcium- Dependent Gating of Anoctamin1/TMEM16A  

PubMed Central

Anoctamin1 (Ano1, or TMEM16A) is a Ca2+-activated chloride channel that is gated by both voltage and Ca2+. We have previously identified that the first intracellular loop that contains a high density of acidic residues mediates voltage- and calcium-dependent gating of Ano1. Mutation of the four consecutive glutamates (444EEEE447) inhibits the voltage-dependent activation of Ano1, whereas deletion of these residues decreases apparent Ca2+ sensitivity. In the present study, we further found that deletion of 444EEEEEAVKD452 produced a more than 40-fold decrease in the apparent Ca2+ sensitivity with altered activation kinetics. We then systematically mutated each acidic residue into alanine, and analyzed the voltage- and calcium dependent activation of each mutation. Activation kinetics of wild type Ano1 consisted of a fast component (?fast) that represented voltage-dependent mode, and a slow component (?slow) that reflected the Ca2+-dependent modal gating. E444A, E445A, E446A, E447A, E448A, and E457A mutations showed a decrease in the ?fast, significantly inhibited voltage-dependent activation of Ano1 in the absence of Ca2+, and greatly shifted the G-V curve to the right, suggesting that these glutamates are involved in voltage-gating of Ano1. Furthermore, D452A, E464A, E470A, and E475A mutations that did not alter voltage-dependent activation of the channel, significantly decreased Ca2+ dependence of G-V curve, exhibited an increase in the ?slow, and produced a 2–3 fold decrease in the apparent Ca2+ sensitivity, suggesting that these acidic residues are involved in Ca2+-dependent gating of the channel. Our data show that acidic residues in the first intracellular loop are the important structural determinant that couples the voltage and calcium dependent gating of Ano1.

Xiao, Qinghuan; Cui, Yuanyuan

2014-01-01

248

Evaluation of the natural product antifoulant, zosteric acid, for preventing the attachment of quagga mussels--a preliminary study.  

PubMed

The effectiveness of zosteric acid, a natural antifoulant from the marine seagrass Zostera marina, in preventing the attachment of quagga mussels, a biofouling bivalve, was investigated. Animals were exposed to water containing zosteric acid ranging from 0 to 1000?ppm, and their attachment to the container glass walls was tracked with time. 500?ppm zosteric acid was not effective at detaching animals that had already attached, but was able to prevent the attachment of most unattached animals for two days. The anti-fouling effect increased with higher concentration. Low concentrations (250?ppm and below) were not effective at preventing attachment; however, 1000?ppm zosteric acid prevented attachment of mussels for the first three days of zosteric acid exposure, and only 20% of the mussels were attached by day 4. In contrast, animals in control (no zosteric acid) solutions began to attach within one day. In conclusion, zosteric acid is an effective natural product deterrent of attachment of a biofouling bivalve. PMID:21861646

Ram, Jeffrey L; Purohit, Sonal; Newby, Bi-Min Zhang; Cutright, Teresa J

2012-01-01

249

Salicylic acid, hydrogen peroxide and calcium-induced saline tolerance associated with endogenous hydrogen peroxide homeostasis in naked oat seedlings  

Microsoft Academic Search

This study investigates the role of salicylic acid (SA), hydrogen peroxide (H2O2) and calcium chloride (CaCl2) singly or in combination, in inducing naked oat plant tolerance to sodium chloride (NaCl). Two-week-old naked oat plants\\u000a were pretreated with both single and double of 0.5 mM SA, 0.5 mM H2O2 and 5 mM CaCl2 by adding them to the culture solution for 24 h. At the

Qiang Xu; Xin Xu; Yan Zhao; Kun Jiao; Stephen J. Herbert; Lin Hao

2008-01-01

250

Partial replacement of corn grain with calcium salts of fatty acid in the concentrate fed to grazing primiparous and multiparous dairy cows  

Microsoft Academic Search

The effects of the partial replacement of corn grain with calcium salts of unsaturated fatty acids (CSFA) on milk yield and composition, milk?fatty acid profile and parameters linked to body lipid mobilisation were examined in 32 multiparous (MC) and 18 primiparous (PC) grazing cows in early lactation. Cows grazed a lucerne pasture and received a concentrate composed (DM basis) of

G. F. Schroeder; G. A. Gagliostro

2007-01-01

251

Investigation of Acid Deposition Effects on Southern Appalachian Red Spruce (Picea rubens) by Determination of Calcium, Magnesium, and Aluminum in Foliage and Surrounding Soil Using Icp-Oes  

Microsoft Academic Search

Red spruce (Picea rubens) are conifers found at high elevations (above 1370 m) sites in the Southern Appalachian Mountains. A decline of red spruce forests in the Southern Appalachian Mountains caused by atmospheric acid deposition has been reported since the 1970s. Acid deposition leaches essential nutrients (calcium and magnesium) out of the soil and increases the availability of toxic metals (aluminum)

Matthew B. Rosenberg; David J. Butcher

2010-01-01

252

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

253

Dual SO{sub 2}-NO{sub x} concentration reduction by calcium salts of carboxylic acids  

SciTech Connect

This research continues the investigation of agents that are capable of simultaneously removing SO{sub 2} and Mo{sub x} from the effluent of coal-fired power plants. The simultaneous removal of SO{sub 2} and NO{sub x} by calcium salts of carboxylic acids was evaluated in a laboratory-scale furnace in atmospheres containing 2,000 ppm SO{sub 2}, 1,000 ppm NO, 3% O{sub 2}, and 12% CO{sub 2} at gas temperatures between 550 and 1,250 C (825 and 1,425 K) with a residence times of 4 s in an isothermal zone. The salts studied included calcium formate (CF, Ca(COOH){sub 2}), calcium acetate (CA, Ca(CH{sub 2}COOH){sub 2}), calcium propionate CP, (Ca(CH{sub 2}CH{sub 2}COOH){sub 2}) and calcium benzoate (CB, Ca(C{sub 6}H{sub 4}COOH){sub 2}). Maximum reductions in SO{sub 2} concentration due to the formation of CaSO{sub 4} were recorded as follows: 60% for CP, 55% for CR, 35% for CA, and 18% for CB at gas temperatures in the neighborhood of 950 C and at a Ca/s molar ratio near 2.8. With the organic portion of the injected salts acting as secondary fuel for NO{sub x} control, maximum NO{sub x} concentration reductions were 88% for CP, 65% for CB, 22% for CA and less than 10% for CF at gas temperatures near 950 C at bulk equivalence ratios that varied between 0.5 for CF and 2.1 for CB. A recently constructed, narrower furnace increased the gas flow velocities and the particle dispersion in the gas. Therein, at residence times as low as 1 s, CP achieved simultaneous SO{sub 2} and NO{sub x} removal of over 80% at gas temperatures {ge}950 C. the addition of an oxidizing zone following the carboxylic acid sorbent injection zone affected the overall SO{sub 2}-NO{sub x} removal according to the stoichiometry of the sorbent injection zone. When this zone was: (1) fuel-lean, the overall SO{sub 2} removal improved; (2) stoichiometric, the overall SO{sub 2} removal was not affected; and (3) significantly fuel-rich , the overall SO{sub 2} removal worsened.

Steciak, J.; Levendis, Y.A.; Wise, D.L. [Northeastern Univ., Boston, MA (United States); Simons, G.A. [Simons Research Association, Lynnfield, MA (United States)

1995-08-01

254

Hyperuricosuric calcium oxalate nephrolithiasis  

Microsoft Academic Search

Many investigators have observed that renal calcium stones may be associated with uric acid disorders. Prien and Prien [1] noted that patients with gout who had stone disease frequently passed stones which contained or were composed of calcium oxalate. Gutman [2] also observed a high frequency of calcium oxalate stones in patients who had gout; and he called attention to

Fredric L Coe

1978-01-01

255

Androgenesis in Hordeum vulgare L.: Effects of mannitol, calcium and abscisic acid on anther pretreatment  

Microsoft Academic Search

Pretreatment-induced androgenesis of Hordeum vulgare L. cv. Igri was investigated in order to find factors which control optimal plant production. The influence of what is called pre-medium and of the concentration of both mannitol and calcium were studied. Increasing concentrations of each of the compounds, also resulting in a higher osmolality, improved both embryo like structure (ELS) and plant productions.

S Hoekstra; S van Bergen; I. R van Brouwershaven; R. A Schilperoort; M Wang

1997-01-01

256

Prevention by calcium antagonists of profibrillatory effects of class I antiarrhythmic drugs in acute myocardial ischemia: study in pig heart in situ.  

PubMed

Class I antiarrhythmic drugs do not decrease, but increase, the risk of ventricular fibrillation in the ischemic myocardium. On the contrary, vulnerability to fibrillation related to ischemia appears to be substantially reduced by calcium antagonists. We assessed whether the calcium antagonist diltiazem (0.50 mg/kg bolus plus 0.02 mg/kg/min infusion) could prevent the profibrillatory effect or even partially restore the antifibrillatory effect of a class I antiarrhythmic drug, flecainide (1 mg/kg bolus plus 0.04 mg/kg/min infusion) in the ischemic myocardium of anesthetized, open-chest pigs. Ischemia was obtained by completely occluding the left anterior descending coronary artery near its origin. Vulnerability to fibrillation was assessed by electrical fibrillation threshold (EFT), measured with diastolic impulses of 100 msec duration delivered at a rate of 180 beats/minute. Diltiazem did not oppose the rise in EFT induced by flecainide in the absence of ischemia (6.8 +/- 1.2 to 9.9 +/- 0.9 mA, p<0.001). It limited the fall in EFT observed under the dual influence of ischemia and flecainide (4.2 +/- 0.9 vs 1.3 +/- 0.6 mA, p<0.001). By reducing calcium entry into myocardial fibers, diltiazem delayed ischemic depolarization, as evidenced by reduced shortening of the monophasic action potential duration from 215 +/- 7 to 200 +/- 4 msec, instead of 178 +/- 6 (p<0.001), and reduced lengthening of intraventricular conduction time from 33 +/- 5 to 43 +/- 4 msec, instead of 53 +/- 4 (p<0.01). Therefore, diltiazem is likely to prevent the loss and even the reversal of the antifibrillatory properties of flecainide due to myocardial ischemia in dosages that do not adversely affect myocardial contractility or atrioventricular conduction to a large extent. PMID:9250551

Bui-Xuan, B; Aupetit, J F; Freysz, M; Faucon, G; Timour, Q

1997-01-01

257

The effect of four levels of ascorbic acid and two levels of calcium on eggshell quality of forced-molted White Leghorn hens.  

PubMed

The present experiment evaluated the effect of four levels of ascorbic acid (0, 100, 250, and 500 ppm) and two levels of calcium (3.0 and 3.5%) on the productivity and eggshell quality of molted Single Comb White Leghorn hens, housed four per 30.5 cm wide x 45.7 cm deep cage. The 4 x 2 factorial treatment combinations were randomly assigned to eight blocks of cages. Egg production increased (P < .06) an average of 5% for the levels of 250 and 500 ppm ascorbic acid. No differences were observed for feed consumption, egg weight, and shell thickness for the different levels of ascorbic acid or calcium in the diet. An increase (P < .01) was observed for specific gravity, as the levels of ascorbic acid increased. Increasing the level of calcium from 3.0 to 3.5% increased (P < .01) specific gravity from 1.073 to 1.075. Shell weight increased (P < .01) with the higher levels of ascorbic acid (250 and 500 ppm). No interactions were observed between the levels of ascorbic acid and calcium. Results suggest that supplementing ascorbic acid to molted laying hens can be beneficial to egg production and eggshell quality. PMID:7644417

Zapata, L F; Gernat, A G

1995-06-01

258

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

259

Hyaluronic acid stimulates the formation of calcium phosphate on CoCrMo alloy in simulated physiological solution.  

PubMed

The behaviour of CoCrMo alloy has been studied in two simulated physiological solutions-NaCl and Hanks' solutions-each containing the sodium salt of hyaluronic acid. Hyaluronic acid is a component of synovial joint fluid, so the behaviour of orthopaedic alloys in its presence needs to be assessed. Electrochemical methods, X-ray photoelectron spectroscopy and scanning electron microscopy have been used to analyse the composition, thickness and morphology of any layers formed on the alloy. The addition of hyaluronic acid shifts the corrosion potential and increases the value of polarization resistance. The presence of hyaluronic acid in simulated Hanks' physiological solution stimulates the formation of a calcium phosphate layer, opening up the possibility for tailoring the surface properties of CoCrMo alloy. The viability of human osteoblast-like was determined using the Alamar(®) Blue Assay, while the osteogenic activity was evaluated by alkaline phosphatase activity. The presence of hyaluronic acid affects the alkaline phosphatase activity. PMID:23250579

Milošev, Ingrid; Hmeljak, Julija; Cör, Andrej

2013-03-01

260

Combined inhalational and oral supplementation of ascorbic acid may prevent influenza pandemic emergency: a hypothesis.  

PubMed

Occurrence of influenza pandemics is a worldwide phenomenon and a significant cause of mortality and morbidity throughout the globe. It is due to mutations in the influenza virus genetic material creating antigenic drift of pathogenic viral proteins resulting in emergence of new influenza virus strains. Therefore, the vaccines available for prevention of influenza offer no protection against influenza pandemics caused by new virus strains. Moreover, the existing drugs used to combat influenza may be ineffective to treat influenza pandemics due to the emergence of drug resistance in the pandemic virus strain. Therefore, a working strategy must be developed to combat influenza pandemics. In this review we have addressed this problem and reviewed the published studies on ascorbic acid in the common cold and influenza and laboratory studies on the effect of ascorbic acid on influenza virus. We have also correlated the clinical and laboratory studies and developed a hypothesis to prevent influenza pandemics. PMID:20005468

Banerjee, Dibyajyoti; Kaul, Deepak

2010-01-01

261

Inhibitory effects of calcium antagonists on mitochondrial swelling induced by lipid peroxidation or amchidonic acid in the rat brain in vitro  

Microsoft Academic Search

Inhibitory effects of calcium antagonists, efonidipine (NZ-105), nicardipine, nifedipine, nimodipine and flunarizine, on mitochondrial swelling induced by lipid peroxidation or arachidonic acid in the rat brain in vitro were investigated. Mitochondrial swelling and lipid peroxidation induced by FeSO4 and ascorbic acid system showed a close and significant relationship. Mitochondrial swelling and lipid peroxidation induced by FeSO4 and ascorbic acid were

Mineo Takei; Midori Hiramatsu; Akitane Mori

1994-01-01

262

The two calcium-binding proteins, S100A8 and S100A9, are involved in the metabolism of arachidonic acid in human neutrophils.  

PubMed

Recently, we identified the two myeloid related protein-8 (MRP8) (S100A8) and MRP14 (S100A9) as fatty acid-binding proteins (Klempt, M., Melkonyan, H., Nacken, W., Wiesmann, D., Holtkemper, U., and Sorg, C. (1997) FEBS Lett. 408, 81-84). Here we present data that the S100A8/A9 protein complex represents the exclusive arachidonic acid-binding proteins in human neutrophils. Binding and competition studies revealed evidence that (i) fatty acid binding was dependent on the calcium concentration; (ii) fatty acid binding was specific for the protein complex formed by S100A8 and S100A9, whereas the individual components were unable to bind fatty acids; (iii) exclusively polyunsaturated fatty acids were bound by S100A8/A9, whereas saturated (palmitic acid, stearic acid) and monounsaturated fatty acids (oleic acid) as well as arachidonic acid-derived eicosanoids (15-hydroxyeicosatetraenoic acid, prostaglandin E(2), thromboxane B(2), leukotriene B(4)) were poor competitors. Stimulation of neutrophil-like HL-60 cells with phorbol 12-myristate 13-acetate led to the secretion of S100A8/A9 protein complex, which carried the released arachidonic acid. When elevation of intracellular calcium level was induced by A23187, release of arachidonic acid occurred without secretion of S100A8/A9. In view of the unusual abundance in neutrophilic cytosol (approximately 40% of cytosolic protein) our findings assign an important role for S100A8/A9 as mediator between calcium signaling and arachidonic acid effects. Further investigations have to explore the exact function of the S100A8/A9-arachidonic acid complex both inside and outside of neutrophils. PMID:10551823

Kerkhoff, C; Klempt, M; Kaever, V; Sorg, C

1999-11-12

263

Prolonged Diuretic Activity and Calcium-Sparing Effect of Tropaeolum majus: Evidence in the Prevention of Osteoporosis  

PubMed Central

Although several studies indicate high effectiveness in the use of the hydroethanolic extract from Tropaeolum majus (HETM) as a diuretic, the impact of its prolonged use in the presence of low estrogen levels remains unclear. Thus, the aim of this study was to investigate the diuretic effects of prolonged administration of HETM in ovariectomized rats and their interrelationship between calcium excretion and bone turnover. Forty-two female Wistar rats were ovariectomized (OVX) and treated orally with different doses of HETM (3, 30, and 300?mg/kg) for 4 weeks. On the first day of treatment and at weekly intervals for four weeks the diuretic activity was evaluated. Electrolyte concentrations and creatinine levels were estimated from urine sample of each rat. The serum lipids, urea, creatinine, and osteocalcin were also measured at the end of the experiment. The data revealed that the HETM was able to sustain its diuretic effect after prolonged treatment. Moreover, its use has not affected the urinary calcium or potassium excretion, reduces lipid levels, and maintains osteocalcin levels similarly to untreated rats. These findings support the potential of HETM as a candidate to be used in clinical conditions in which the renal loss of calcium is not desired.

Barboza, Lorena Neris; Prando, Thiago Bruno Lima; Dalsenter, Paulo Roberto; Gasparotto, Francielly Mourao; Gasparotto, Francielli; Jacomassi, Ezilda; Araujo, Valdinei de Oliveira; Lourenco, Emerson Luiz Botelho; Gasparotto Junior, Arquimedes

2014-01-01

264

Prolonged Diuretic Activity and Calcium-Sparing Effect of Tropaeolum majus: Evidence in the Prevention of Osteoporosis.  

PubMed

Although several studies indicate high effectiveness in the use of the hydroethanolic extract from Tropaeolum majus (HETM) as a diuretic, the impact of its prolonged use in the presence of low estrogen levels remains unclear. Thus, the aim of this study was to investigate the diuretic effects of prolonged administration of HETM in ovariectomized rats and their interrelationship between calcium excretion and bone turnover. Forty-two female Wistar rats were ovariectomized (OVX) and treated orally with different doses of HETM (3, 30, and 300?mg/kg) for 4 weeks. On the first day of treatment and at weekly intervals for four weeks the diuretic activity was evaluated. Electrolyte concentrations and creatinine levels were estimated from urine sample of each rat. The serum lipids, urea, creatinine, and osteocalcin were also measured at the end of the experiment. The data revealed that the HETM was able to sustain its diuretic effect after prolonged treatment. Moreover, its use has not affected the urinary calcium or potassium excretion, reduces lipid levels, and maintains osteocalcin levels similarly to untreated rats. These findings support the potential of HETM as a candidate to be used in clinical conditions in which the renal loss of calcium is not desired. PMID:25028592

Barboza, Lorena Neris; Prando, Thiago Bruno Lima; Dalsenter, Paulo Roberto; Gasparotto, Francielly Mourão; Gasparotto, Francielli; Jacomassi, Ezilda; Araújo, Valdinei de Oliveira; Lourenço, Emerson Luiz Botelho; Gasparotto Junior, Arquimedes

2014-01-01

265

Prevention of ischemia-induced cardiac Sudden death by n?3 polyunsaturated fatty acids in dogs  

Microsoft Academic Search

The objective of this study was to obtain functional information associated with the prevention by n?3 polyunsaturated fatty\\u000a acids (PUFA) of ischemia-induced fatal cardiac ventricular arrhythmias in the intact, conscious, exercising dog. Thirteen\\u000a dogs suceptible to ischemia-induced ventricular fibrillation were prepared surgically by ligation of their anterior descending\\u000a left coronary artery and placement of an inflatable cuff around their left

George E. Billman; Jing X. Kang; Alexander Leaf

1997-01-01

266

Tauroursodeoxycholic acid (TUDCA) in the prevention of total parenteral nutrition-associated liver disease  

Microsoft Academic Search

Objective: To determine whether tauroursodeoxycholic acid (TUDCA) would prevent or ameliorate the liver injury in neonates treated with total parenteral nutrition (TPN). Study design: Eligible infants were enrolled after surgery when serum direct bilirubin (DB) was <2 mg\\/dL. TUDCA (30 mg\\/kg\\/day) was given enterally to 22 subjects. A concurrent untreated\\/placebo group was evaluated for comparison (n = 30). Blood chemistries

James E. Heubi; David A. Wiechmann; Vivian Creutzinger; Kenneth D. R. Setchell; Robert Squires; Robert Couser; Philip Rhodes

2002-01-01

267

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

268

Determination of citric acid based on inhibition of the crystal growth of calcium fluoride.  

PubMed

Inhibition of the growth of calcium fluoride crystals in the presence of citrate was followed using a kinetic-potentiometric technique and a calcium ion-selective electrode, and as a consequence, a method for the determination of citrate in the range 0.5-2.4 micrograms ml-1 has been developed. The method was successfully applied to the determination of citrate contained in pharmaceutical products and urine. Urine analysis requires prior separation of phosphate, sulphate and magnesium(II). Elimination of these interferences was studied and accomplished using precipitation processes. Magnesium and phosphate were jointly eliminated in basic media by the addition of ammonium ions. Phosphate and sulphate were eliminated with barium(II). Phosphate was also eliminated as a lithium salt. PMID:2008941

Grases, F; Costa-Bauzá, A; March, J G

1991-01-01

269

An attempt to reduce calcium phosphate deposits on cobaltic oxide pellets by citric acid treatment  

Microsoft Academic Search

ExtractAt least under New Zealand conditions, the use of cobaltic oxide pellets (“cobalt bullets”) to control cobalt deficiency in sheep is limited by a tendency of the bullet to accumulate deposits of calcium phosphate (Andrews, 1961). Although the use of steel “grinders” (for example, in the form of 1\\/2 in. × 1\\/2 in. engineer's grub screws) has been recommended as

E. D. Andrews; B. J. Stephenson; C. E. Isaacs

1964-01-01

270

Deltamethrin Multifactorial Activity toward Carp Larva Mobility Related to Calcium, Humic Acids, and pH  

Microsoft Academic Search

The toxicity of pyrethroid insecticide deltamethrin was assesssed by the “escaping capability” of carp larvae out of a trap. Mobility was tested after 1, 4, and 12 hr exposure to eight deltamethrin concentrations in standard water and after 24 hr exposure to seven deltamethrin concentrations in 18 media derived from the combinations of pH levels of 6.9, 7.8, 9.0, calcium

François Ghillebaert; Didier Prodorutti; Catherine Chaillou; Pierre Roubaud

1996-01-01

271

Calcium gating of H + fluxes in chloroplasts affects acid-base-driven ATP formation  

Microsoft Academic Search

In previous work, calcium ions, bound at the lumenal side of the CF0H+ channel, were suggested to keep a H+ flux gating site closed, favoring sequestered domain H+ ions flowing directly into the CF0-CF1 and driving ATP formation by a localized\\u000a$$\\\\Delta \\\\tilde \\\\mu _{H^ + } $$\\u000a gradient. Treatments expected to displace Ca++ from binding sites had the effect

Dennis C. Wooten; Richard A. Dilley

1993-01-01

272

Calcium- and polyphosphate-containing acidic granules of sea urchin eggs are similar to acidocalcisomes, but are not the targets for NAADP  

PubMed Central

Acidocalcisomes are acidic calcium-storage compartments described from bacteria to humans and characterized by their high content in poly P (polyphosphate), a linear polymer of many tens to hundreds of Pi residues linked by high-energy phosphoanhydride bonds. In the present paper we report that millimolar levels of short-chain poly P (in terms of Pi residues) and inorganic PPi are present in sea urchin extracts as detected using 31P-NMR, enzymatic determinations and agarose gel electrophoresis. Poly P was localized to granules randomly distributed in the sea urchin eggs, as shown by labelling with the poly-P-binding domain of Escherichia coli exopolyphosphatase. These granules were enriched using iodixanol centrifugation and shown to be acidic and to contain poly P, as determined by Acridine Orange and DAPI (4?,6?-diamidino-2-phenylindole) staining respectively. These granules also contained large amounts of calcium, sodium, magnesium, potassium and zinc, as detected by X-ray microanalysis, and bafilomycin A1-sensitive ATPase, pyrophosphatase and exopolyphosphatase activities, as well as Ca2+/H+ and Na+/H+ exchange activities, being therefore similar to acidocalcisomes described in other organisms. Calcium release from these granules induced by nigericin was associated with poly P hydrolysis. Although NAADP (nicotinic acid–adenine dinucleotide phosphate) released calcium from the granule fraction, this activity was not significantly enriched as compared with the NAADP-stimulated calcium release from homogenates and was not accompanied by poly P hydrolysis. GPN (glycyl-L-phenylalanine-naphthylamide) released calcium when added to sea urchin homogenates, but was unable to release calcium from acidocalcisome-enriched fractions, suggesting that these acidic stores are not the targets for NAADP.

Ramos, Isabela B.; Miranda, Kildare; Pace, Douglas A.; Verbist, Katherine C.; Lin, Fu-Yang; Zhang, Yonghui; Oldfield, Eric; Machado, Ednildo A.; De Souza, Wanderley; Docampo, Roberto

2010-01-01

273

Evaluation of the natural product antifoulant, zosteric acid, for preventing the attachment of quagga mussels – a preliminary study  

Microsoft Academic Search

The effectiveness of zosteric acid, a natural antifoulant from the marine seagrass Zostera marina, in preventing the attachment of quagga mussels, a biofouling bivalve, was investigated. Animals were exposed to water containing zosteric acid ranging from 0 to 1000?ppm, and their attachment to the container glass walls was tracked with time. 500?ppm zosteric acid was not effective at detaching animals

Jeffrey L. Ram; Sonal Purohit; Bi-min Zhang Newby; Teresa J. Cutright

2011-01-01

274

Evaluation of the natural product antifoulant, zosteric acid, for preventing the attachment of quagga mussels – a preliminary study  

Microsoft Academic Search

The effectiveness of zosteric acid, a natural antifoulant from the marine seagrass Zostera marina, in preventing the attachment of quagga mussels, a biofouling bivalve, was investigated. Animals were exposed to water containing zosteric acid ranging from 0 to 1000?ppm, and their attachment to the container glass walls was tracked with time. 500?ppm zosteric acid was not effective at detaching animals

Jeffrey L. Ram; Sonal Purohit; Bi-min Zhang Newby; Teresa J. Cutright

2012-01-01

275

pH sensitive polyelectrolyte complex of O-carboxymethyl chitosan and poly (acrylic acid) cross-linked with calcium for sustained delivery of acid susceptible drugs.  

PubMed

The present study investigates the ability of a polyelectrolyte complex, composed of O-carboxymethyl chitosan (O-CMC) and carbopol cross linked with calcium, as a pH-sensitive carrier for acid susceptible drugs. DSC studies were performed to confirm the formation of O-CMC-carbopol complex. Double endothermic peaks in thermogram of polyelectrolyte beads reflect the molecular changes brought in after cross-linking. FT-IR spectroscopy was used to reveal peak variation of the carboxylic groups as a function of pH 1.2 and pH 6.8. The formation of polyelectrolyte complex, on account of electrostatic interactions between the COO(-) group of carbopol and the NH(3)(+) group of O-CMC, was also confirmed by FT-IR studies. Swelling of the O-CMC-carbopol film showed a pH-dependent profile that was affected by calcium ion concentration. The swelling rate was more significant at intestinal pH because the ionization of carboxylic acid group on O-CMC and carbopol creates electrostatic repulsion. Release behavior of drug is relative to the viscosity of solution and the ionic interaction between O-CMC and carbopol. Mucous glycoprotein assay revealed that ionization of carboxylic group on the beads at intestinal pH formed a strong hydrogen bond with mucin, which was responsible for the prominent mucoadhesive property thus prolonging the intestinal residence time. PMID:22814224

Gujarathi, Nayan A; Rane, Bhushan R; Patel, Jayvadan K

2012-10-15

276

Complex Forming Properties of Natural Occurring Fulvic Acids. Part 1. Complexes with Cadmium, Copper and Calcium.  

National Technical Information Service (NTIS)

The experimental program developed in our earlier investigations of the protonation equilibria encountered with Armadale Horizons Bh and Suwannee River fulvic-acid has been employed in the present investigation of a Swedish fulvic acid source. Complicatio...

J. A. Marinsky A. Mathuthu M. Bicking J. Ephraim

1985-01-01

277

Are conjugated linolenic acid isomers an alternative to conjugated linoleic acid isomers in obesity prevention?  

PubMed

Despite its benefits, conjugated linoleic acid (CLA) may cause side effects after long-term administration. Because of this and the controversial efficacy of CLA in humans, alternative biomolecules that may be used as functional ingredients have been studied in recent years. Thus, conjugated linolenic acid (CLNA) has been reported to be a potential anti-obesity molecule which may have additional positive effects related to obesity. According to the results reported in obesity, CLNA needs to be given at higher doses than CLA to be effective. However, because of the few studies conducted so far, it is still difficult to reach clear conclusions about the potential use of these CLNAs in obesity and its related changes (insulin resistance, dyslipidemia, or inflammation). PMID:24029409

Miranda, Jonatan; Arias, Noemi; Fernández-Quintela, Alfredo; del Puy Portillo, María

2014-04-01

278

In vitro elution of moxifloxacin and fusidic acid by a synthetic crystallic semihydrate form of calcium sulphate (Stimulan).  

PubMed

Stimulan was evaluated in vitro as a biodegradable carrier for local delivery of moxifloxacin and fusidic acid. Moxifloxacin or fusidic acid was mixed with calcium sulphate at a ratio of 95:5 to prepare five replicas per antibiotic. In vitro elution was estimated daily using a high-performance liquid chromatography (HPLC) system. Elution of moxifloxacin lasted for 31 days. Eluted concentrations reached their peak on Day 13 (mean level 745 microg/mL); the lowest eluted concentration was detected on Day 30 (mean level 367 microg/mL). Elution of fusidic acid lasted for 14 days. Eluted concentrations reached their peak on Day 6 (mean value 249.5 microg/mL); the lowest eluted concentration was detected on Day 13 (mean value 10.9 microg/mL). The presented results revealed that Stimulan may allow adequate in vitro elution of moxifloxacin and fusidic acid. The latter results support the application of this system in experimental models of osteomyelitis. PMID:18790611

Panagopoulos, Periklis; Tsaganos, Thomas; Plachouras, Diamantis; Carrer, Dionyssia-Pinelopi; Papadopoulos, Antonios; Giamarellou, Helen; Kanellakopoulou, Kyriaki

2008-12-01

279

Imbricatolic acid from Juniperus communis L. prevents cell cycle progression in CaLu-6 cells.  

PubMed

Imbricatolic acid was isolated from the methanolic extract of the fresh ripe berries of Juniperus communis (Cupressaceae) together with sixteen known compounds and a new dihydrobenzofuran lignan glycoside named juniperoside A. Their structures were determined by spectroscopic methods and by comparison with the spectral data reported in literature. Imbricatolic acid was evaluated for its ability to prevent cell cycle progression in p53-null CaLu-6 cells. This compound induces the upregulation of cyclin-dependent kinase inhibitors and their accumulation in the G1 phase of the cell cycle, as well as the degradation of cyclins A, D1, and E1. Furthermore, no significant imbricatolic acid-induced apoptosis was observed. Therefore, this plant-derived compound may play a role in the control of cell cycle. PMID:21567359

De Marino, Simona; Cattaneo, Fabio; Festa, Carmen; Zollo, Franco; Iaccio, Annalisa; Ammendola, Rosario; Incollingo, Filomena; Iorizzi, Maria

2011-11-01

280

Preconceptional folic acid-containing supplement use in the national birth defects prevention study.  

PubMed

Background: Despite public health campaigns encouraging women to take a daily folic acid supplement, the proportion of reproductive age women, in the United States, who comply with this recommendation is less than optimal. The objective of this analysis was to identify predictors of preconceptional folic acid-containing supplement use to define subgroups of women who may benefit from targeted folic acid campaigns. Methods: This study included 6570 mothers of live born infants from the control population of National Birth Defects Prevention Study (1997-2005). Logistic regression analyses were used to identify predictors of preconceptional folic acid supplementation. A classification and regression tree (CART) analysis was used to define subgroups of women with different patterns of preconceptional folic acid supplementation. Results: Race/ethnicity, education, age at delivery, nativity, employment, income, number of dependents, smoking, and birth control use were significantly associated with preconceptional folic acid-containing supplement use. Based on a CART analysis, education, race/ethnicity, and age were the most distinguishing factors between women with different preconceptional supplementation patterns. Non-white women with <4 years of a college education were the least likely to use folic acid-containing supplements (11%). However, even in the most compliant subgroup (women with ?4 years of college), only 60% of women supplemented with folic acid. Conclusion: These results demonstrate the need for continued efforts to increase folic acid supplementation among all reproductive aged women. However, the success of such efforts may be improved if maternal characteristics such as education, race/ethnicity, and age, are considered in the development of future interventions. Birth Defects Research (Part A) 100:472-482, 2014. © 2014 Wiley Periodicals, Inc. PMID:24706436

Khodr, Zeina G; Lupo, Philip J; Agopian, A J; Canfield, Mark A; Case, Amy P; Carmichael, Suzan L; Mitchell, Laura E

2014-06-01

281

The value of the thromboelastogram as means of monitoring the sub-cutaneous preventive action of calcium heparinate.  

PubMed

The index of the thrombodynamic potential (I.T.P.) as one of the biological means of controlling the prophylactic effect of sub-cutaneous injections of Calcium Heparinate has been studied in 34 spinal cord injuries during the acute phase. Individual tolerance variations, some of them important, have been noted as well as the necessity of adjusting the doses, according to the time after injury. A biological hypercoagulability has been noted within the first and third month after injury. The interest and the cost of such a method are discussed and further comparative biological investigations, using other methods, have started. PMID:7413237

Dollfus, P; Bouchier, J J; Henon, P; Jung, G; Issler, M

1980-06-01

282

Polished rice as natural sources of cancer-preventing geranylgeranoic acid  

PubMed Central

Geranylgeranoic acid, a 20-carbon polyprenoic acid (all-trans 3,7,11,15-tetramethyl-2,4,6,10,14-hexadecatetraenoic acid) and its derivatives were previously developed as synthetic “acyclic retinoids” for cancer chemoprevention. Recently, we demonstrated the natural occurrence of geranylgeranoic acid in various medicinal herbs (Shidoji and Ogawa, 2004). In this present study, we present several lines of evidence to demonstrate that geranylgeranyl diphosphate taken in foods could be metabolized to GGA through geranylgeraniol and geranylgeranyl aldehyde via the following steps: 1) The conversion from geranylgeranyl diphosphate to geranylgeraniol was demonstrated to occur by the action of bovine intestinal alkaline phosphatase, with a Km of 46.1 µM. 2) Geranylgeraniol oxidase-mediated conversion of geranylgeraniol to geranylgeranyl aldehyde was revealed in rat liver homogenates, which activity was mainly localized in the mitochondrial fraction. The mitochondrial enzyme showed a Km of 92.9 µM. 3) The conversion of geranylgeranyl aldehyde to geranylgeranoic acid by geranylgeranyl aldehyde dehydrogenase in rat liver homogenates was absolutely dependent on exogenously added NAD+ or NADP+. The Km of the mitochondrial geranylgeranyl aldehyde dehydrogenase was 27.5 µM for geranylgeranyl aldehyde. Taken together, our data suggest that cancer preventive geranylgeranoic acid could be a physiological metabolite from commonly consumed foods.

Muraguchi, Takashi; Okamoto, Kyoko; Mitake, Maiko; Ogawa, Hiroko; Shidoji, Yoshihiro

2011-01-01

283

Fatty acids and breast cancer: sensitization to treatments and prevention of metastatic re-growth.  

PubMed

Lifestyle and nutritional factors have been recognized to influence breast cancer survival, irrespective of genomic alterations that are the hallmarks of the disease. The biological and molecular mechanisms involved in the effects of dietary polyunsaturated fatty acids and breast cancer response to treatments in clinical and preclinical studies have been reviewed. Among nutrients, rumenic acid, a naturally occurring CLA isomer and n-3 docosahexaenoic acid (DHA) a highly unsaturated fatty acid, have emerged due to their potential to increase cancer treatment efficacy without additional side effects. In this review, we analyze the literature evidence that breast cancer treatment and outcome could be improved through an adjuvant dietary supplementation. Such an original approach would involve two successive phases of breast cancer treatment: an initial sensitization of residual tumor cells to chemotherapy and to radiation therapy with dietary DHA; then a prevention of metastatic re-growth with a prolonged rumenic acid supplementation. Safety is not anticipated to be a critical issue, although it has to be assessed in the long term. Dietary supplements, used in combination to anti-cancer agents, should be provided under medical prescription. Such an original use of fatty acids in breast cancer treatment could provide the lipid field with a new avenue to impact public health. PMID:19715726

Bougnoux, Philippe; Hajjaji, Nawale; Maheo, Karine; Couet, Charles; Chevalier, Stephan

2010-01-01

284

Palmitic acid and DGAT1 deficiency enhance osteoclastogenesis, while oleic acid-induced triglyceride formation prevents it.  

PubMed

Both obesity and diabetes mellitus are associated with alterations in lipid metabolism as well as a change in bone homeostasis and osteoclastogenesis. We hypothesized that increased fatty acid levels affect bone health by altering precursor cell differentiation and osteoclast activation. Here we show that palmitic acid (PA, 16:0) enhances receptor activator of NF-?B ligand (RANKL)-stimulated osteoclastogenesis and is sufficient to induce osteoclast differentiation even in the absence of RANKL. TNF? expression is crucial for PA-induced osteoclastogenesis, as shown by increased TNF? mRNA levels in PA-treated cells and abrogation of PA-stimulated osteoclastogenesis by TNF? neutralizing antibodies. In contrast, oleic acid (OA, 18:1) does not enhance osteoclast differentiation, leads to increased intracellular triglyceride accumulation, and inhibits PA-induced osteoclastogenesis. Adenovirus-mediated expression of diacylglycerol acyl transferase 1 (DGAT1), a gene involved in triglyceride synthesis, also inhibits PA-induced osteoclastogenesis, suggesting a protective role of DGAT1 for bone health. Accordingly, Dgat1 knockout mice have larger bone marrow-derived osteoclasts and decreased bone mass indices. In line with these findings, mice on a high-fat PA-enriched diet have a greater reduction in bone mass and structure than mice on a high-fat OA-enriched diet. Thus, we propose that TNF? mediates saturated fatty acid-induced osteoclastogenesis that can be prevented by DGAT activation or supplementation with OA. PMID:24272998

Drosatos-Tampakaki, Zoi; Drosatos, Konstantinos; Siegelin, Yasemin; Gong, Shan; Khan, Salmiyeh; Van Dyke, Thomas; Goldberg, Ira J; Schulze, P Christian; Schulze-Späte, Ulrike

2014-05-01

285

Immunolocalization of an acid phosphatase from pearl oyster (Pinctada fucata) and its in vitro effects on calcium carbonate crystal formation.  

PubMed

Distribution of an acid phosphatase, AcPase I, from pearl oyster (Pinctada fucata) in different tissues was investigated via enzyme activity determination and immunohistochemistry. Positive reactions were observed in sections of digestive gland, base of gill filaments, and epithelia of the outer side of the middle fold and the inner side of the outer fold, which indicated AcPase I might participate in processes besides immune defense, such as calcium metabolism or shell formation. Its effects on CaCO(3) crystal formation were studied in vitro. Results revealed that AcPase I inhibited CaCO(3) precipitation in a dose-dependent manner and had no affinity for calcium. CaCO(3) crystals induced by AcPase I exhibited a cluster needle-like morphology, which proved to be aragonite. The morphology and size of the aragonites varied with different concentrations of AcPase I. Our observations described here may provide important clues to further understanding of the correlations between mineralization and immune defense in the oyster. PMID:17619219

Jing, Gu; Yan, Zhenguang; Li, Yu; Xie, Liping; Zhang, Rongqing

2007-01-01

286

Kallikrein Expression and Cathelicidin Processing Are Independently Controlled in Keratinocytes by Calcium, Vitamin D3, and Retinoic Acid  

PubMed Central

Cathelicidin has dual functions in the skin, acting as an innate antibiotic and as an immunomodulator in diseases such as rosacea and psoriasis. The serine proteases kallikrein 5 (KLK5) and kallikrein 7 (KLK7) control enzymatic processing of cathelicidin precursor in the skin and regulate the eventual function of the final forms of these peptides. We analyzed factors that control expression of KLK5 and KLK7 in normal human epidermal keratinocytes to better understand how these may influence cathelicidin processing and function. Increased extracellular calcium-induced KLK5 and KLK7 mRNA expression and protein release in a time-dependent manner that is similar to induction of differentiation markers such as keratin 10 and involucrin. However, 1,25(OH)2 vitamin D3, 9-cis retinoic acid (RA), and 13-cisRA also induced the KLKs, but the timing and pattern of KLK induction for each were different and distinct from changes in differentiation markers. Increased protease activity and differential processing of cathelicidin accompanied increased KLK expression. These findings show that the expression and activity of KLK are under fine control and can be distinctly influenced by variables such as differentiation, calcium, vitamin D, and RA. Thus, these variables may further control the functions of antimicrobial peptides in the skin.

Morizane, Shin; Yamasaki, Kenshi; Kabigting, Filamer D.; Gallo, Richard L.

2010-01-01

287

Tanshinone IIA and Cryptotanshinone Prevent Mitochondrial Dysfunction in Hypoxia-Induced H9c2 Cells: Association to Mitochondrial ROS, Intracellular Nitric Oxide, and Calcium Levels  

PubMed Central

The protective actions of tanshinones on hypoxia-induced cell damages have been reported, although the mechanisms have not been fully elucidated. Given the importance of nitric oxide (NO) and reactive oxygen species (ROS) in regulation of cell functions, the present study investigated the effects of two major tanshinones, Tanshinone IIA (TIIA) and cryptotanshinone (CT), on hypoxia-induced myocardial cell injury and its relationships with intracellular NO and ROS, calcium, and ATP levels in H9c2 cells. Chronic hypoxia significantly reduced cell viability which accompanied with LDH release, increase in mitochondrial ROS, intracellular NO and calcium levels, decrease in superoxide dismutase (SOD) activity, and cellular ATP contents. TIIA and CT significantly prevented cell injury by increasing cell viability and decreasing LDH release. The protective effects of tanshinones were associated with reduced mitochondrial superoxide production and enhanced mitochondrial SOD activity. Tanshinones significantly reduced intracellular NO and Ca2+ levels. ATP levels were also restored by TIIA. These findings suggest that the cytoprotective actions of tanshinones may involve regulation of intracellular NO, Ca2+, ATP productions, mitochondrial superoxide production, and SOD activity, which contribute to their actions against hypoxia injuries.

Jin, Hyou-Ju; Li, Chun-Guang

2013-01-01

288

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

289

Regulation of Arachidonic Acid Release by Calcium Influx in Human Endothelial Cells  

Microsoft Academic Search

In response to stimuli, endothelial cells release arachidonic acid, a lipid precursor of various vasoactive substances. We have investigated the relationships between cytosolic Ca2+ movements and arachidonic acid release in human umbilical vein endothelial cells. Histamine, a receptor-dependent agonist, and thapsigargin, a specific inhibitor of sarco-\\/endoplasmic Ca2+ pumps, time- and dose-dependently increased the release of [1-14C]-arachidonic acid. This release was

Elisabeth Millanvoye-Van Brussel; Monique David-Dufilho; Thuc Do Pham; Lahcen Iouzalen; Marie Aude Devynck

1999-01-01

290

Omega-3 fatty acid oxidation products prevent vascular endothelial cell activation by coplanar polychlorinated biphenyls.  

PubMed

Coplanar polychlorinated biphenyls (PCBs) may facilitate development of atherosclerosis by stimulating pro-inflammatory pathways in the vascular endothelium. Nutrition, including fish oil-derived long-chain omega-3 fatty acids, such as docosahexaenoic acid (DHA, 22:6?-3), can reduce inflammation and thus the risk of atherosclerosis. We tested the hypothesis that cyclopentenone metabolites produced by oxidation of DHA can protect against PCB-induced endothelial cell dysfunction. Oxidized DHA (oxDHA) was prepared by incubation of the fatty acid with the free radical generator 2,2-azo-bis(2-amidinopropane) dihydrochloride (AAPH). Cellular pretreatment with oxDHA prevented production of superoxide induced by PCB77, and subsequent activation of nuclear factor-?B (NF-?B). A?/J?-neuroprostanes (NPs) were identified and quantitated using HPLC ESI tandem mass spectrometry. Levels of these NPs were markedly increased after DHA oxidation with AAPH. The protective actions of oxDHA were reversed by treatment with sodium borohydride (NaBH?), which concurrently abrogated A?/J?-NP formation. Up-regulation of monocyte chemoattractant protein-1 (MCP-1) by PCB77 was markedly reduced by oxDHA, but not by un-oxidized DHA. These protective effects were proportional to the abundance of A?/J? NPs in the oxidized DHA sample. Treatment of cells with oxidized eicosapentaenoic acid (EPA, 20:5?-3) also reduced MCP-1 expression, but less than oxDHA. Treatment with DHA-derived cyclopentenones also increased DNA binding of NF-E2-related factor-2 (Nrf2) and downstream expression of NAD(P)H:quinone oxidoreductase (NQO1), similarly to the Nrf-2 activator sulforaphane. Furthermore, sulforaphane prevented PCB77-induced MCP-1 expression, suggesting that activation of Nrf-2 mediates the observed protection against PCB77 toxicity. Our data implicate A?/J?-NPs as mediators of omega-3 fatty acid-mediated protection against the endothelial toxicity of coplanar PCBs. PMID:21130106

Majkova, Zuzana; Layne, Joseph; Sunkara, Manjula; Morris, Andrew J; Toborek, Michal; Hennig, Bernhard

2011-02-15

291

Overexpression of PDZ1 domain prevents apoptosis of rat hippocampal neurons induced by kainic acid.  

PubMed

In our previous studies, Tat-GluR6-9c (a glutamate receptor 6 C-terminus peptide fused the TAT protein transduction sequence) not only inhibited the activation of MLK3 (mixed lineage kinase 3) and JNK (c-Jun N-terminal kinase) via the GluR6.PSD-95 (postsynaptic density protein 95).MLK3 signaling module but also diminished neuronal death induced by kainic acid or transient cerebral ischemia in rat hippocampus. Here, we investigate whether overexpression of the PDZ1 domain of PSD-95 protein could suppress the binding of GluR6 with PSD-95 and the activation of MLK3, MKK7 (mitogen-activated kinase kinase 7) and JNK1/2, and rescused neuronal cell death induced by kainic acid. Our results showed that overexpression of the PDZ1 domain of PSD-95 protein could prevent nuclear accumulation and abrogate neuronal cell death in SD (Sprague-Dawley) rat hippocampal neuronal cells. Further studies indicated that overexpression of PDZ1 could inhibit the enhancement of binding of GluR6 to PSD-95 and prevent the activation of MLK3, MKK7 and JNK1/2 induced by kainic acid. Taken together, the essential role of the PDZ1 domain of PSD-95 in apoptotic cell death in neurons provides an experimental foundation for gene therapy of neurodegenerative diseases with overexpression of the PDZ1 domain. PMID:19477222

Hu, Shu-Qun; Zong, Yan-Yan; Fan, Le-Ming; Zhang, Guang-Yi

2009-08-28

292

21 CFR 184.1187 - Calcium alginate.  

Code of Federal Regulations, 2010 CFR

...RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1187 Calcium alginate. (a) Calcium alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown...

2010-01-01

293

Effect of a calcium soap of fatty acids on reproductive characteristics and lactation performance of fat-tailed sheep.  

PubMed

Experiments were carried out to study the effect of feeding Megalac, calcium soaps of fatty acids (protected fat), on reproduction and lactation of sheep. In the first experiment, 20 Ghezel and 20 Mehraban cyclic fertile ewes (4-5 years old) were randomly allotted to 4 groups. The control group was fed with a balanced ration and the other groups received the same diet as well as a daily allowance of 40 g non-protected fat (NP), 40 g protected fat (LP), or 80 g (HP) protected fat. The ewes were fed with their respective rations for one cycle length. Blood samples were collected and analyzed for progesterone (P4), cholesterol (CHOL), High Density Lipoproteins (HDL), Low Density Lipoproteins (LDL) and triacylglycerols (TG). The ewes were slaughtered on their next estrous period and the size and number of follicles in ovaries were recorded. There were no significant effects of feeding fat on ovarian weights, cycle length and follicular numbers in each class, or on the size of the largest follicle. Serum concentrations of P4, CHOL, TG and HDL were greater for HP ewes as compared with the control ewes (p<0.05). In the second experiment, effects on lactation and lamb performance of feeding protected fat during mating, late gestation and early lactation were studied in Mehraban ewes. Milk and fat yields on day 25 of lactation were significantly increased by feeding protected fat. Protected fat resulted in lower weight loss in ewes and a higher lamb birth weight. Average daily weight gain of lambs from birth to day 60 and the weaning weight of lambs were increased by feeding protected fat (p<0.05). In conclusion, calcium soaps of fatty acids increased serum P4 between days 10 to 14 of the cycle which may be beneficial to early pregnancy maintenance. Protected fat seemed to have a beneficial effect on milk yield, fat yield, lamb daily gain, lamb birth weight and ewe weight loss. PMID:19070162

Ghoreishi, S M; Zamiri, M J; Rowghani, E; Hejazi, H

2007-07-15

294

Nutritional interventions to prevent and treat osteoarthritis. Part I: focus on fatty acids and macronutrients.  

PubMed

Osteoarthritis (OA) is the most common cause of musculoskeletal disability in elderly individuals, and it places an enormous economic burden on society. Management of OA is primarily focused on palliative relief by using agents such as nonsteroidal anti-inflammatory drugs and analgesics. However, such an approach is limited by a narrow therapeutic focus that fails to address the progressive and multimodal nature of OA. Given the favorable safety profile of most nutritional interventions, identifying disease-modifying nutritional agents capable of improving symptoms and also preventing, slowing, or even reversing the degenerative process in OA should remain an important paradigm in translational and clinical research. Applying advances in nutritional science to musculoskeletal medicine remains challenging, given the fluid and dynamic nature of the field, along with a rapidly developing regulatory climate over manufacturing and commerce requirements. The aim of this article is to review the available literature on effectiveness and potential mechanism of macronutrients for OA, with a focus on the following: long-chain ?-3 essential fatty acids eicosapentaenoic acid and docosahexaenoic acid, functional ?-6 fatty acid ?-linolenic acid, and macronutrient composition of background diet. There also is a discussion about the concept of rational polysupplementation via the strategic integration of multiple nutraceuticals with potential complementary mechanisms for improving outcomes in OA. As applied nutritional science evolves, it will be important to stay on the forefront of proteomics, metabolomics, epigenetics, and nutrigenomics, because they hold enormous potential for developing novel therapeutic and prognostic breakthroughs in many areas of medicine, including OA. PMID:22632694

Lopez, Hector L

2012-05-01

295

Continuous production of gibberellic acid in a fixed-bed reactor by immobilized mycelia of Gibberella fujikuroi in calcium alginate beads  

Microsoft Academic Search

The continuous production of gibberellic acid with immobilized mycelia of Gibberella fujikuroi was maintained over a hundred days in a tubular fixed-bed reactor. Free mycelium at the beginning of the storage phase was harvested from G. fujikuroi shake-flask culture and was immobilized by ionotropic gelation in calcium alginate beads.

José Edmundo Nava Saucedo; Jean-Noël Barbotin; Daniel Thomas

1989-01-01

296

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

297

Human milk beyond one year post-partum: lower content of protein, calcium, and saturated very long-chain fatty acids.  

PubMed

Maternal milk feeding for more than 1 year is encouraged by many health care authorities. We demonstrate that human milk beyond 1 year of lactation had a small but significantly lower concentration of protein, calcium, and long-chain saturated fatty acids compared with human milk at 3 months after delivery. PMID:16423611

Shehadeh, Naim; Aslih, Nardin; Shihab, Shihab; Werman, Moshe J; Sheinman, Rivkah; Shamir, Raanan

2006-01-01

298

Effect of Addition of Citric Acid and Casein Phosphopeptide-Amorphous Calcium Phosphate to a Sugar-Free Chewing Gum on Enamel Remineralization in situ  

Microsoft Academic Search

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has been shown to remineralize enamel subsurface lesions in situ. The aim of this study was to investigate the effects of CPP-ACP in a fruit-flavoured sugar-free chewing gum containing citric acid on enamel remineralization, and acid resistance of the remineralized enamel, using an in situ remineralization model. The study utilized a double-blind, randomized, crossover design

F. Cai; D. J. Manton; P. Shen; G. D. Walker; K. J. Cross; Y. Yuan; C. Reynolds; E. C. Reynolds

2007-01-01

299

Prevention of bone mineral changes induced by bed rest: Modification by static compression simulating weight bearing, combined supplementation of oral calcium and phosphate, calcitonin injections, oscillating compression, the oral diophosphonatedisodium etidronate, and lower body negative pressure  

NASA Technical Reports Server (NTRS)

The phenomenon of calcium loss during bed rest was found to be analogous to the loss of bone material which occurs in the hypogravic environment of space flight. Ways of preventing this occurrence are investigated. A group of healthy adult males underwent 24-30 weeks of continuous bed rest. Some of them were given an exercise program designed to resemble normal ambulatory activity; another subgroup was fed supplemental potassium phosphate. The results from a 12-week period of treatment were compared with those untreated bed rest periods. The potassium phosphate supplements prevented the hypercalciuria of bed rest, but fecal calcium tended to increase. The exercise program did not diminish the negative calcium balance. Neither treatment affected the heavy loss of mineral from the calcaneus. Several additional studies are developed to examine the problem further.

Schneider, V. S.; Hulley, S. B.; Donaldson, C. L.; Vogel, J. M.; Rosen, S. N.; Hantman, D. A.; Lockwood, D. R.; Seid, D.; Hyatt, K. H.; Jacobson, L. B.

1974-01-01

300

Omega-3 polyunsaturated fatty acids: a necessity for a comprehensive secondary prevention strategy  

PubMed Central

Long-chain omega-3 polyunsaturated fatty acid (PUFA) supplementation has been used for the secondary prevention of fatal and nonfatal myocardial infarction (MI). However, the benefit of this therapy is frequently confused with other established treatments in the therapeutic strategy among such patients. We review the data on omega-3 PUFA use in secondary care and consider indications for its use which include post-MI and raised triglycerides. We suggest that the available evidence supports the use of omega-3 supplementation as part of the comprehensive secondary care package for post-MI patients.

Patel, Jeetesh V; Tracey, Inessa; Hughes, Elizabeth A; Lip, Gregory YH

2009-01-01

301

The effect of treatment of acidosis on calcium balance in patients with chronic azotemic renal disease.  

PubMed

Small but statistically significant negative calcium balances were found in each of eight studies in seven patients with chronic azotemic renal disease when stable metabolic acidosis was present. Only small quantities of calcium were excreted in the urine, but fecal calcium excretion equaled or exceeded dietary intake. Complete and continuous correction of acidosis by NaHCO(3) therapy reduced both urinary and fecal calcium excretion and produced a daily calcium balance indistinguishable from zero. Apparent acid retention was found throughout the studies during acidosis, despite no further reduction of the serum bicarbonate concentration. The negative calcium balances that accompanied acid retention support the suggestion that slow titration of alkaline bone salts provides an additional buffer reservoir in chronic metabolic acidosis. The treatment of metabolic acidosis prevented further calcium losses but did not induce net calcium retention. It is suggested that the normal homeostatic responses of the body to the alterations in ionized calcium and calcium distribution produced by raising the serum bicarbonate might paradoxically retard the repair of skeletal calcium deficits. PMID:6018764

Litzow, J R; Lemann, J; Lennon, E J

1967-02-01

302

A poly(lactic acid)/calcium metaphosphate composite for bone tissue engineering.  

PubMed

A new method to prepare PLA/CMP (poly-L-lactide/calcium metaphosphate) composite scaffolds was developed for effective bone tissue engineering. This novel sintering method is composed of pressing the mixture of PLA, CMP, and salt particles at 150 MPa for 3 min followed by heat treatment at 210 degrees C for 30 min. The scaffolds had a homogeneously interconnected porous structure without a skin layer, and they exhibited a narrower pore size distribution and higher mechanical strength in comparison with scaffolds made by a solvent casting method. The scaffolds were seeded by osteoblasts and cultured in vitro or implanted into nude mice subcutaneously for up to 5 weeks. The number of cells attached to and proliferated on the scaffolds at both in vitro and in vivo was in the order of; PLA by novel sintering < PLA/CMP by solvent casting < PLA/CMP by novel sintering. In addition, the alkaline phosphatase activity of and calcium deposition in the scaffolds explanted from mice were enhanced significantly for the scaffolds by novel sintering compared to them by solvent casting. The in vitro results agreed well with the in vivo data. Such a superior characteristic of the novel sintering method should have resulted from the fact that the CMP particles could contact directly with cells/tissues to stimulate the cell proliferation and osteogenic differentiation, while the CMP particles would be coated by polymers and hindered to interact with cells/tissues in the case of a solvent casting method. As the novel sintering method does not use any solvents it offers another advantage to avoid problems associated with solvent residue. PMID:15913759

Jung, Youngmee; Kim, Sang-Soo; Kim, Young Ha; Kim, Sang-Heon; Kim, Byung-Soo; Kim, Sukyoung; Choi, Cha Yong; Kim, Soo Hyun

2005-11-01

303

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.

2011-01-01

304

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

305

Cancer Preventive Agents 9. Betulinic Acid Derivatives as Potent Cancer Chemopreventive Agents †  

PubMed Central

C-3 Esterifications of betulinic acid (BA, 1) and its A-ring homolog, ceanothic acid (CA, 2), were carried out to provide sixteen terpenoids, 4-19, including nine new compounds (4-12). All synthesized compounds were evaluated in an in vitro antitumor-promoting assay using the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. Among them, compounds 4-6, 11-14, 16, and 17 displayed remarkable inhibitory effects of EBV-EA activation. BA analog 6, which contains a prenyl-like group, showed the most potent inhibitory effect (100, 76, 37, and 11% inhibition of EBA activation at 1000, 500, 100 and 10 mol ratio/TPA, respectively, with IC50 value of 285 mol ratio/32pmol TPA). Compound 6 merits further development as a cancer preventive agent.

Nakagawa-Goto, Kyoko; Yamada, Koji; Taniguchi, Masahiko; Tokuda, Harukuni; Lee, Kuo-Hsiung

2009-01-01

306

[All-trans retinoic acid (ATRA) in prevention and cancer therapy].  

PubMed

Retinoids are useful pharmacological agents in therapy and prevention of cancer. All-trans retinoic acid (ATRA) is applied in chemoprevention and differentiation therapy of some cancers with particularly impressive results in the management of acute promyelocytic leukemia (APL). ATRA plays a major role in regulating growth and differentiation of a wide variety of normal and malignant cell types. ATRA mediates these effects by regulating gene transcription. Nuclear retinoic acid receptors (RARs) are considered to be the mediators of most of the effects of ATRA on gene expression. We present a current state of knowledge on the effects of ATRA on cell growth and differentiation as well as describe RARs and their role in the cellular mechanism of ATRA action. A particular attention was paid to the effects of ATRA on proliferation and differentiation of cancer cells. PMID:20558866

Hoffman, Ewelina; Mielicki, Wojciech P

2010-01-01

307

Mineralisation of reconstituted collagen using polyvinylphosphonic acid/polyacrylic acid templating matrix protein analogues in the presence of calcium, phosphate and hydroxyl ions.  

PubMed

The complex morphologies of mineralised collagen fibrils are regulated through interactions between the collagen matrix and non-collagenous extracellular proteins. In the present study, polyvinylphosphonic acid, a biomimetic analogue of matrix phosphoproteins, was synthesised and confirmed with FTIR and NMR. Biomimetic mineralisation of reconstituted collagen fibrils devoid of natural non-collagenous proteins was demonstrated with TEM using a Portland cement-containing resin composite and a phosphate-containing fluid in the presence of polyacrylic acid as sequestration, and polyvinylphosphonic acid as templating matrix protein analogues. In the presence of these dual biomimetic analogues in the mineralisation medium, intrafibrillar and extrafibrillar mineralisation via bottom-up nanoparticle assembly based on the non-classical crystallisation pathway could be identified. Conversely, only large mineral spheres with no preferred association with collagen fibrils were observed in the absence of biomimetic analogues in the medium. Mineral phases were evident within the collagen fibrils as early as 4 h after the initially-formed amorphous calcium phosphate nanoprecursors were transformed into apatite nanocrystals. Selected area electron diffraction patterns of highly mineralised collagen fibrils were nearly identical to those of natural bone, with apatite crystallites preferentially aligned along the collagen fibril axes. PMID:20621767

Kim, Young Kyung; Gu, Li-sha; Bryan, Thomas E; Kim, Jong R; Chen, Liang; Liu, Yan; Yoon, James C; Breschi, Lorenzo; Pashley, David H; Tay, Franklin R

2010-09-01

308

Mineralisation of reconstituted collagen using polyvinylphosphonic acid/polyacrylic acid templating matrix protein analogues in the presence of calcium, phosphate and hydroxyl ions  

PubMed Central

The complex morphologies of mineralised collagen fibrils are regulated through interactions between the collagen matrix and non-collagenous extracellular proteins. In the present study, polyvinylphosphonic acid, a biomimetic analogue of matrix phosphoproteins, was synthesised and confirmed with FTIR and NMR. Biomimetic mineralisation of reconstituted collagen fibrils devoid of natural non-collagenous proteins was demonstrated with TEM using a Portland cement-containing resin composite and a phosphate-containing fluid in the presence of polyacrylic acid as sequestration, and polyvinylphosphonic acid as templating matrix protein analogues. In the presence of these dual biomimetic analogues in the mineralisation medium, intrafibrillar and extrafibrillar mineralisation via bottom-up nanoparticle assembly based on the nonclassical crystallisation pathway could be identified. Conversely, only large mineral spheres with no preferred association with collagen fibrils were observed in the absence of biomimetic analogues in the medium. Mineral phases were evident within the collagen fibrils as early as 4 hours after the initially-formed amorphous calcium phosphate nanoprecursors were transformed into apatite nanocrystals. Selected area electron diffraction patterns of highly mineralised collagen fibrils were nearly identical to those of natural bone, with apatite crystallites preferentially aligned along the collagen fibril axes.

Kim, Young Kyung; Gu, Li-sha; Bryan, Thomas E.; Kim, Jong Ryul; Chen, Liang; Liu, Yan; Yoon, James C.; Breschi, Lorenzo; Pashley, David H.; Tay, Franklin R.

2010-01-01

309

Docosahexaenoic acid prevents palmitate-induced activation of proteolytic systems in C2C12 myotubes.  

PubMed

Saturated fatty acids like palmitate contribute to muscle atrophy in a number of conditions (e.g., type II diabetes) by altering insulin signaling. Akt is a key modulator of protein balance that inhibits the FoxO transcription factors (e.g., FoxO3) which selectively induce the expression of atrophy-inducing genes (atrogenes) in the ubiquitin-proteasome and autophagy-lysosome systems. Conversely, omega-3 polyunsaturated fatty acids have beneficial effects on insulin signaling and may preserve muscle mass. In an earlier report, the omega-3 fatty acid docosahexaenoic acid (DHA) protected myotubes from palmitate-induced atrophy; the mechanisms underlying the alterations in protein metabolism were not identified. This study investigated whether DHA prevents a palmitate-induced increase in proteolysis by restoring Akt/FoxO signaling. Palmitate increased the rate of protein degradation, while cotreatment with DHA prevented the response. Palmitate reduced the activation state of Akt and increased nuclear FoxO3 protein while decreasing its cytosolic level. Palmitate also increased the messenger RNAs (mRNAs) of two FoxO3 atrogene targets, the E3 ubiquitin ligase atrogin-1/MAFbx and the autophagy mediator Bnip3. DHA attenuated the effects of palmitate on Akt activation, FoxO3 localization and atrogene mRNAs. DHA, alone or in combination with palmitate and decreased the ratio of LC3B-II:LC3B-I protein as well as the rate of autophagosome formation, as indicated by reduced LC3B-II protein in the presence of 10 mmol/L methylamine, suggesting an independent effect of DHA on the macroautophagy pathway. These data indicate that palmitate induces myotube atrophy, at least in part, by activating multiple proteolytic systems and that DHA counters the catabolic effects of palmitate by restoring Akt/FoxO signaling. PMID:24835079

Woodworth-Hobbs, Myra E; Hudson, Matthew B; Rahnert, Jill A; Zheng, Bin; Franch, Harold A; Price, S Russ

2014-08-01

310

Efficacy of Organic Acids in Hand Cleansers for Prevention of Rhinovirus Infections  

PubMed Central

Direct hand-to-hand contact is an important mechanism of transmission of rhinovirus infection. The rhinoviruses are inactivated at a low pH. A survey of organic acids in vitro revealed that these compounds have antirhinoviral activity that persists for at least 3 h after application to the skin. In additional studies of salicylic acid (SA) and pyroglutamic acid (PGA), the hands of volunteers were contaminated with rhinovirus at defined times after application of the acid, and then volunteers attempted to inoculate the nasal mucosa with one hand and quantitative viral cultures were done on the other hand. In one study, 3.5% SA or 1% SA with 3.5% PGA was compared with controls 15 min after application to assess the efficacy of the inactivation of virus and prevention of infection. Virus was recovered from the hands of 28 out of 31 (90%) of the volunteers in the control group compared to 4 out of 27 (15%) and 0 out of 27 in the groups administered 3.5 and 1% SA, respectively (P < 0.05). Rhinovirus infection occurred in 10 out of 31 (32%) of the controls and 2 out of 27 (7%) of volunteers in both treatment groups (P < 0.05 compared with control). In a second study, the efficacy of 4% PGA was evaluated 15 min, 1 h, and 3 h after application. Significantly fewer volunteers had positive hand cultures at all time points compared with the control group, but the proportion that developed rhinovirus infection was not significantly reduced. These results suggest the feasibility of the prevention of rhinovirus transmission by hand treatments that are virucidal on contact and have activity that persists after application.

Turner, Ronald B.; Biedermann, Kim A.; Morgan, Jeffery M.; Keswick, Bruce; Ertel, Keith D.; Barker, Mark F.

2004-01-01

311

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.

Moezizadeh, Maryam; Alimi, Azar

2014-01-01

312

Increased tissue levels of omega-3 polyunsaturated fatty acids prevents pathological preterm birth  

PubMed Central

Omega-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) have anti-inflammatory effects. Preterm birth is an important problem in modern obstetrics and one of the main causes is an inflammation. We here showed that abundance of omega-3 fatty acids reduced the incidence of preterm birth induced by LPS with fat-1 mice, capable of converting omega-6 to omega-3 fatty acids. We also indicated that the gene expression of IL-6 and IL-1? in uteruses and the number of cervical infiltrating macrophages were reduced in fat-1 mice. The analyses of lipid metabolomics showed the high level of 18-hydroxyeicosapentaenoate in fat-1 mice, which was derived from EPA and was metabolized to anti-inflammatory product named resolvin E3 (RvE3). We finally showed that the administration of RvE3 to LPS-exposed pregnant wild type mice lowered the incidence of preterm birth. Our data suggest that RvE3 could be a potential new therapeutic for the prevention of preterm birth.

Yamashita, Aki; Kawana, Kei; Tomio, Kensuke; Taguchi, Ayumi; Isobe, Yosuke; Iwamoto, Ryo; Masuda, Koji; Furuya, Hitomi; Nagamatsu, Takeshi; Nagasaka, Kazunori; Arimoto, Takahide; Oda, Katsutoshi; Wada-Hiraike, Osamu; Yamashita, Takahiro; Taketani, Yuji; Kang, Jing X.; Kozuma, Shiro; Arai, Hiroyuki; Arita, Makoto; Osuga, Yutaka; Fujii, Tomoyuki

2013-01-01

313

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

314

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.

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

2014-01-01

315

Secondary prevention of heart disease – knowledge among cardiologists and ?-3 (Omega3) fatty acid prescribing behaviors in Karachi, Pakistan  

Microsoft Academic Search

BACKGROUND: The use of omega-3 fatty acids is a currently proven strategy for secondary prevention of heart disease. The prescription practices for this important nutraceutical is not currently known. It is imperative to assess the knowledge of cardiologists regarding the benefits of omega-3 fatty acids and to determine the frequency of its prescription. The aim of the study was to

Saqib A Gowani; Sana Shoukat; Ather M Taqui; Hashim M Hanif; Wasiq F Rawasia; Zeeshan Qadri; Sajid H Dhakam

2009-01-01

316

Role of intracellular calcium and NADPH oxidase NOX5-S in acid-induced DNA damage in Barrett's cells and Barrett's esophageal adenocarcinoma cells.  

PubMed

Mechanisms whereby acid reflux may accelerate the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. Acid and reactive oxygen species (ROS) have been reported to cause DNA damage in Barrett's cells. We have previously shown that NADPH oxidase NOX5-S is responsible for acid-induced H2O2 production in Barrett's cells and in EA cells. In this study we examined the role of intracellular calcium and NADPH oxidase NOX5-S in acid-induced DNA damage in a Barrett's EA cell line FLO and a Barrett's cell line CP-A. We found that pulsed acid treatment significantly increased tail moment in FLO and CP-A cells and histone H2AX phosphorylation in FLO cells. In addition, acid treatment significantly increased intracellular Ca(2+) in FLO cells, an increase that is blocked by Ca(2+)-free medium with EGTA and thapsigargin. Acid-induced increase in tail moment was significantly decreased by NADPH oxidase inhibitor diphenylene iodonium in FLO cells, and by blockade of intracellular Ca(2+) increase or knockdown of NOX5-S with NOX5 small-interfering RNA (siRNA) in FLO and CP-A cells. Acid-induced increase in histone H2AX phosphorylation was significantly decreased by NOX5 siRNA in FLO cells. Conversely, overexpression of NOX5-S significantly increased tail moment and histone H2AX phosphorylation in FLO cells. We conclude that pulsed acid treatment causes DNA damage via increase of intracellular calcium and activation of NOX5-S. It is possible that in BE acid reflux increases intracellular calcium, activates NOX5-S, and increases ROS production, which causes DNA damage, thereby contributing to the progression from BE to EA. PMID:24699332

Li, Dan; Cao, Weibiao

2014-05-15

317

Efficacy of casein phosphopeptide-amorphous calcium phosphate to prevent stain absorption on freshly bleached enamel: An in vitro study  

PubMed Central

Background: Teeth when subjected to bleaching bring about the desiccation of the enamel, making it more susceptible to stain absorption. While subjecting the freshly bleached enamel surface to various surface treatments of Fluoride and Casein Phosphopeptide - Amorphous Calcium phosphate (CPP-ACP) brought about the reduction in stain absorption, which is assessed in this study. Aims: The study aims to evaluate the tea stain absorption on freshly bleached enamel surface of extracted human teeth with varied surface treatment. The stain absorption was evaluated at the end of one hour and 24 hours post bleaching. Materials and Methods: Forty extracted human permanent maxillary central incisors were subjected to bleaching with 10% carbamide peroxide for eight days. They were divided into four groups of 10 each. Group I was control group. Group II was immersed in tea solution without surface treatment, while Group III and IV were immersed in tea solution with surface treatment of topical Fluoride and CPP-ACP respectively. Spectrophotometer was used for color analysis. Results: Surface treatment with CPP-ACP and topical fluoride on freshly beached enamel surface, significantly reduced the stain absorption. Conclusion: Remineralizing agents reduce stain absorption after tooth bleaching.

Singh, Raghuwar D; Ram, Sabita M; Shetty, Omkar; Chand, Pooran; Yadav, Rakesh

2010-01-01

318

Lipoic acid prevents Cr(6+) induced cell transformation and the associated genomic dysregulation.  

PubMed

Investigation of the transcription profile of cells transformed by Cr(6+) in vivo was undertaken. The objective was to elucidate genomic changes underlying the mechanism of action of the carcinogenic dose of Cr(6+)and their prevention using metabolic antioxidant lipoic acid (LA). Cr(6+) was administered intraperitoneally to LPS+TPA challenged Swiss albino mice in host mediated cell transformation assay using peritoneal macrophages in vivo. The cell transforming potential of Cr(6+) test doses was validated by gain of anchorage independent growth potential in soft agar and loss of Fc receptor on target cells. LA was administered in equimolar doses. Compared to non-transformed cells, the gene expression profile of transformed cells was found to be dysregulated substantially and in dose dependent manner. Genes showing down regulation were found to be involved in tumour suppression, apoptosis, DNA repair, and cell-cycle. A similar response was noted in the genes pertaining to immune system, morphogenesis, cell-communication, energy-metabolism, and biosynthesis. The co-administration of lipoic acid prevented the transcription dysregulation and cell transformation by Cr(6+) in vivo. The influenced pathways seem to be crucial for progression as well as mitigation of Cr toxicity; and their response to LA indicated their critical role in mechanism of anti-carcinogenic action of LA. Results are of importance to mitigate Cr(6+) induced occupational cancer hazard. PMID:23608068

Kumar, Sushil; Nigam, Akanksha; Priya, Shivam; Bajpai, Preeti; Budhwar, Roli

2013-07-01

319

Somatostatin prevents the postoperative increases in plasma amino acid clearance and urea synthesis after elective cholecystectomy.  

PubMed Central

The importance of glucagon on postoperative changes in hepatic amino-nitrogen conversion were investigated in six patients undergoing elective cholecystectomy for uncomplicated gall stones. Patients were given infusions of somatostatin (bolus of 6 micrograms/kg followed by continuous infusion of 6 micrograms/kg/h) from induction of anaesthesia to the end of investigation, the first postoperative day (30 hours). Controls were 16 patients undergoing the same procedures omitting the somatostatin infusion. In all patients blood concentration and plasma clearance of total alpha-amino-nitrogen, and amino acid stimulated rate of urea synthesis were measured. Elective cholecystectomy decreased blood alpha-amino-nitrogen concentration from mean (SEM) 2.9 (0.2) to 2.4 (0.1) mmol/l (p < 0.05), increased the clearance of total alpha-amino-nitrogen from 5.2 (0.3) to 6.6 (0.3) ml/s (p < 0.05), and increased the rate of amino acid stimulated urea synthesis from 27 (1) to 37 (2) mumol/s (p < 0.05) pointing to increased hepatic removal of amino-nitrogen at expense of plasma amino-nitrogen. Infusion of somatostatin prevented increase of glucagon for 24 hours after surgery, and prevented the negative changes in postoperative nitrogen homeostasis resulting from the postoperative changes in hepatic nitrogen conversion, suggesting glucagon as mediator. The exact mechanism remains in doubt, however, because of the multiple effects of somatostatin.

Heindorff, H; Billesb?lle, P; Pedersen, S L; Hansen, R; Vilstrup, H

1995-01-01

320

Docosahexaenoic Acid Supplementation Early in Pregnancy May Prevent Deep Placentation Disorders  

PubMed Central

Uteroplacental ischemia may cause preterm birth, either due to preterm labor, preterm premature rupture of membranes, or medical indication (in the presence of preeclampsia or fetal growth restriction). Uteroplacental ischemia is the product of defective deep placentation, a failure of invasion, and transformation of the spiral arteries by the trophoblast. The failure of normal placentation generates a series of clinical abnormalities nowadays called “deep placentation disorders”; they include preeclampsia, fetal growth restriction, preterm labor, preterm premature rupture of membranes, in utero fetal death, and placental abruption. Early reports suggested that a LC-PUFAs (long chain polyunsaturated fatty acids) rich diet reduces the incidence of deep placentation disorders. Recent randomized controlled trials are inconsistent to show the benefit of docosahexaenoic acid (DHA) supplementation during pregnancy to prevent deep placentation disorders, but most of them showed that DHA supplementation was associated with lower risk of early preterm birth. We postulate that DHA supplementation, early in pregnancy, may reduce the incidence of deep placentation disorders. If our hypothesis is correct, DHA supplementation, early in pregnancy, will become a safe and effective strategy for primary prevention of highly relevant pregnancy diseases, such as preterm birth, preeclampsia, and fetal growth restriction.

Carvajal, Jorge A.

2014-01-01

321

Fatty Acid Oxidation and Calcium Homeostasis are Involved in the Rescue of Bupivacaine Induced Cardiotoxicity by Lipid Emulsion in Rats  

PubMed Central

OBJECTIVES Lipid Emulsion (LE) has been shown to be effective in resuscitating bupivacaine-induced cardiac arrest but its mechanism of action is not clear. Here we investigated whether fatty acid oxidation is required for rescue of bupivacaine induced cardiotoxicity by LE in rats. We also compared the mitochondrial function and calcium threshold for triggering of mitochondrial permeability transition pore (mPTP) opening in bupivacaine-induced cardiac arrest before and after resuscitation with LE. DESIGN Prospective, randomized, animal study. SETTING University Research Laboratory. SUBJECTS Adult male Sprague-Dawley rats. INTERVENTIONS Asystole was achieved with a single dose of bupivacaine (10mg/kg over 20seconds, i.v.) and 20% LE infusion (5ml/kg bolus, and 0.5ml/kg/min maintenance) with cardiac massage started immediately. The rats in CVT group were pretreated with a single dose of fatty acid oxidation inhibitor CVT (0.5, 0.25, 0.125 or 0.0625mg/kg bolus i.v.) 5min prior to inducing asystole by bupivacaine overdose. Heart rate (HR), ejection fraction (EF), fractional shortening (FS), the threshold for opening of mPTP, oxygen consumption and membrane potential were measured. The values are Mean±SEM. MEASUREMENTS AND MAIN RESULTS Administration of bupivacaine resulted in asystole. ILP infusion improved the cardiac function gradually as the EF was fully recovered within 5min (EF=64±4% and FS=36±3%, n=6) and heart rate increased to 239±9 beats/min (71% recovery, n=6) within 10min. LE was only able to rescue rats pretreated with low dose of CVT (0.0625mg/kg) (HR=~181±11 beats/min at 10 min, recovery of 56%; EF=50±1%; FS=26±0.6% at 5min, n=3) but was unable to resuscitate rats pretreated with higher doses of CVT (0.5, 0.25 or 0.125mg/kg). The calcium retention capacity in response to Ca2+ overload was significantly higher in cardiac mitochondria isolated from rats resuscitated with 20% LE compared to the group that did not receive ILP after bupivacaine-overdose (330±42 vs. 180±8.2 nmol/mg-mitochondrial protein, p<0.05, n=3 in each group). The mitochondrial oxidative rate and membrane potential were similar in bupivacaine group before and after resuscitation with LE infusion. CONCLUSIONS Fatty acid oxidation is required for successful rescue of bupivacaine induced cardiotoxicity by LE. This rescue action is associated with inhibition of mitochondrial permeability transition pore opening.

Partownavid, Parisa; Umar, Soban; Li, Jingyuan; Rahman, Siamak; Eghbali, Mansoureh

2012-01-01

322

Structure and properties of the sodium, potassium and calcium salts of 2-(2,3-dimethylphenyl)aminobenzoic acid  

NASA Astrophysics Data System (ADS)

The mefenamic acid sodium, potassium, and calcium salts with general formulae [Na(mef)(H 2O) 2] n· nH 2O, [K(mef)(H 2O)] n and [Ca(mef) 2(H 2O) 2] n· nH 2O have been synthesised, studied by X-ray crystallography, 1H and 13C NMR and IR spectroscopy. The complex salts are air stable and soluble in water. During heating the Na and K complexes melt in the complexed water and next recrystallise in anhydrous form. In the solid state all salts create one-dimensional coordination polymers. The central atoms are five, six and seven coordinated, respectively, for Na, K and Ca complexes. In all structures exist O sbnd H⋯O, N sbnd H⋯O and C sbnd H⋯O hydrogen bonds. The vibrational analysis has been carried out for mefenamic acid and its three coordination polymer compounds on the basis of experimental results as well as quantum mechanical calculations. The theoretical and experimental vibrational frequencies are similar and reveal characteristic vibrations for all IR active oscillators. In the IR spectra of salts exist strong bands at ca. 1365 and 1600 cm -1 typical for carboxylate groups.

Kruszynski, Rafal; Trzesowska-Kruszynska, Agata; Majewski, Piotr; ?ukaszewicz, Ewa; Majewska, Kamila; Siera?ski, Tomasz; Lewi?ski, Bart?omiej

2010-04-01

323

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.

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.; Ferre, Sergi; Tanda, Gianluigi; Schwarcz, Robert; Goldberg, Steven R.

2013-01-01

324

Effects of calcium hydroxide and calcium chloride addition to bentonite in iron ore pelletization.  

PubMed

Pyrite ash is created as waste from the roasting of pyrite ores during the production of sulphuric acid. These processes generate great amounts of pyrite ash waste that is generally land filled. This creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be utilized in the iron production industry as a blast furnace feed to process this waste and prevent environmental pollution. The essential parameters affecting the pelletization process of pyrite ash were studied using bentonite as a binder. Experiments were then carried out using bentonite and a mixture of bentonite with calcium hydroxide and calcium chloride in order to make the bentonite more effective. The metallurgical properties of pyrite ash, bentonite, calcium hydroxide, calcium chloride, a mixture of these and sintered pellets were studied using X-ray analysis. The crushing strength tests were carried out to investigate the strength of pyrite ash waste pellets. The results of these analyses showed that pyrite ash can be agglomerated to pellets and used in the iron production industry as a blast furnace feed. The crushing strength of the pellets containing calcium hydroxide and calcium chloride in addition to bentonite was better than the strength of pellets prepared using only bentonite binder. PMID:17121116

Tugrul, Nurcan; Derun, Emek Moroydor; Pi?kin, Mehmet

2006-10-01

325

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

326

Vitamin E supplementation does not prevent ethanol-reduced hepatic retinoic acid levels in rats  

PubMed Central

Chronic, excessive ethanol intake can increase retinoic acid (RA) catabolism by inducing cytochrome P450 2E1 (CYP2E1). Vitamin E (VE) is an antioxidant implicated in CYP2E1 inhibition. In the current study, we hypothesized that VE supplementation inhibits CYP2E1 and decreases RA catabolism, thereby preventing ethanol-induced hepatocyte hyperproliferation. For 1 month, four groups of Sprague-Dawley rats were fed a Lieber-DeCarli liquid ethanol (36% of the total calories) diet as follows: either ethanol alone (Alc group) or ethanol in combination with 0.1 mg/kg body wt of all-trans RA (Alc+RA group), 2 mg/kg body wt of VE (Alc+VE group), or both together (Alc+RA+VE group). Control rats were pair-fed a liquid diet with an isocaloric amount of maltodextrin instead of ethanol. The ethanol-fed groups had three-fold higher hepatic CYP2E1 levels, 50% lower hepatic RA levels, and significantly increased hepatocyte proliferation when compared with the controls. The ethanol-fed rats given VE had more than four-fold higher hepatic VE concentrations than did ethanol-fed rats without VE, but this did not prevent ethanol induction of CYP2E1, lower hepatic retinoid levels, or hepatocellular hyperproliferation. Further, VE supplementation could not prevent RA catabolism in liver microsomal fractions of the ethanol-fed rats in vitro. These results show that VE supplementation can neither inhibit ethanol-induced changes in RA catabolism nor prevent ethanol-induced hepatocyte hyperproliferation in the rat liver.

Chung, Jayong; Veeramachaneni, Sudipta; Liu, Chun; Mernitz, Heather; Russell, Robert M.; Wang, Xiang-Dong

2009-01-01

327

[Prevention of migraine with flunarizine and acetylsalicylic acid. A double-blind study].  

PubMed

30 children between 7 and 17 years suffering from at least 2 attacks/month of common or classical migraine since more than 1 year were studied. After clinical exclusion of symptomatic headache 4 weeks were documented by means of a migraine diary. Prophylaxis with Calcium entry blocker Flunarizine (Sibelium) or Thromboxane A inhibitor Acetylsalicylic acid (ASS) was carried out in a double blind design for 3 months. Medication was given as one dosage in the evening: 2-5 mg/kg KG ASS or 5-10 mg Flunarizine. Documented attack frequency and duration were controlled at monthly physical examinations. Final results showed no differences in significant reduction of attack frequency or symptoms between both different therapeutic principals. 72.4% (ASS 73.3%; Flunarizine 71.4%) of patients were attack-free or had at least a 50% reduction. Migraine frequency of initially 7-8 was reduced to 1-2 attacks/month. Duration remained constant in both groups (1-3 h). Side effects were slight body weight gain or abdominal pain after intake, prophylaxis had not to be interrupted therefore. Longtime prognosis is not yet possible because the time of observation is too short so far. Conclusion: Both substances are definitely useful and have few side effects in childhood migraine. If the response to one is insufficient the other substance should be tried. PMID:3313023

Pothmann, R

1987-09-01

328

A traditional Chinese herbal antilithic formula, Wulingsan, effectively prevents the renal deposition of calcium oxalate crystal in ethylene glycol-fed rats.  

PubMed

We investigated the effects of a traditional Chinese herbal formula, Wulingsan (WLS), on renal stone prevention using an ethylene glycol-induced nephrocalcinosis rat model. Forty-one male Sprague-Dawley (SD) rats were divided into four groups. Group 1 (n=8) was the normal control; group 2 (n=11) served as the placebo group, and received a gastric gavage of starch and 0.75% ethylene glycol (EG) as a stone inducer; group 3 received EG and a low dose of WLS (375 mg/kg); and group 4 received EG and a high dose of WLS (1,125 mg/kg). Baseline and final 24 h urine samples were collected individually; biochemical data of urine and serum were also obtained at the beginning and at the end of the experiment. After 4 weeks, animals were killed and kidneys were harvested. The kidney specimens were examined by polarized light microscopy and the crystal deposits were evaluated by a semi-quantitative scoring method using computer software (ImageScoring). The results revealed that the rats of placebo group gained the least significant body weight; in contrast, the rats of WLS-fed groups could effectively reverse it. The placebo group exhibited lower levels of free calcium (p=0.059) and significantly lower serum phosphorus (p=0.015) in urine than WLS-fed rats. Histological findings of kidneys revealed tubular destruction, damage and inflammatory reactions in the EG-water rats. The crystal deposit scores dropped significantly in the WLS groups, from 1.40 to 0.46 in the low-dose group and from 1.40 to 0.45 in the high-dose group. Overall, WLS effectively inhibited the deposition of calcium oxalate (CaOx) crystal and lowered the incidence of stones in rats (p=0.035). In conclusion, WLS significantly reduced the severity of calcium oxalate crystal deposits in rat kidneys, indicating that Wulingsan may be an effective antilithic herbal formula. PMID:18040675

Tsai, Chou-Huang; Chen, Yu-Cheng; Chen, Lieh-Der; Pan, Tien-Chien; Ho, Chien-Yi; Lai, Ming-Tsung; Tsai, Fuu-Jen; Chen, Wen-Chi

2008-02-01

329

Ryanodine receptors contribute to bile acid-induced pathological calcium signaling and pancreatitis in mice  

PubMed Central

Biliary pancreatitis is the most common etiology for acute pancreatitis, yet its pathophysiological mechanism remains unclear. Ca2+ signals generated within the pancreatic acinar cell initiate the early phase of pancreatitis, and bile acids can elicit anomalous acinar cell intracellular Ca2+ release. We previously demonstrated that Ca2+ released via the intracellular Ca2+ channel, the ryanodine receptor (RyR), contributes to the aberrant Ca2+ signal. In this study, we examined whether RyR inhibition protects against pathological Ca2+ signals, acinar cell injury, and pancreatitis from bile acid exposure. The bile acid tauro-lithocholic acid-3-sulfate (TLCS) induced intracellular Ca2+ oscillations at 50 ?M and a peak-plateau signal at 500 ?M, and only the latter induced acinar cell injury, as determined by lactate dehydrogenase (LDH) leakage. Pretreatment with the RyR inhibitors dantrolene or ryanodine converted the peak-plateau signal to a mostly oscillatory pattern (P < 0.05). They also reduced acinar cell LDH leakage, basolateral blebbing, and propidium iodide uptake (P < 0.05). In vivo, a single dose of dantrolene (5 mg/kg), given either 1 h before or 2 h after intraductal TLCS infusion, reduced the severity of pancreatitis down to the level of the control (P < 0.05). These results suggest that the severity of biliary pancreatitis may be ameliorated by the clinical use of RyR inhibitors.

Orabi, Abrahim I.; Muili, Kamaldeen A.; Luo, Yuhuan; Sarwar, Sheharyar; Mahmood, Syeda Maham; Wang, Dong; Choo-Wing, Rayman; Singh, Vijay P.; Parness, Jerome; Ananthanaravanan, Meena; Bhandari, Vineet; Perides, George

2012-01-01

330

Effect of Calcium Salts of Long-Chain Fatty Acids on Dairy Cows in Early Lactation  

Microsoft Academic Search

Twenty dairy cows in early lactation were assigned to one of two dietary treat- ment groups based on milk production and days in milk. Treatments were a total mixed ration containing 13.2% whole cottonseed on a DM basis with or without added Ca salts of long-chain fatty acids. Treatments were fed ad libitum for 11 wk. Dry matter intake and

B. A. Kent; M. J. Arambel

1988-01-01

331

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

332

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

333

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

334

Calcium Supplementation Prevents Seasonal Bone Loss and Changes in Biochemical Markers of Bone Turnover in Elderly New England Women: A Randomized Placebo Controlled Trial  

Microsoft Academic Search

Elderly women are at increased risk for bone loss and fractures. In previous cross-sectional and longitudinal studies of women residing in northern latitudes, bone loss was most pronounced during winter months and in those consuming less than 1 g calcium per day. In this study we sought to test the hypothesis that calcium supplementation by either calcium carbonate or dietary

DEBORAH STORM; REBEKAH ESLIN; EILEEN SMITH PORTER; KATHERINE MUSGRAVE; DONALD VEREAULT; CHRISTINE PATTON; CATHY KESSENICH; SUBBURAMAN MOHAN; TAI CHEN; MICHAEL F. HOLICK; CLIFFORD J. ROSEN

335

Omega-3 fatty acid oxidation products prevent vascular endothelial cell activation by coplanar polychlorinated biphenyls  

PubMed Central

Coplanar polychlorinated biphenyls (PCBs) may facilitate development of atherosclerosis by stimulating pro-inflammatory pathways in the vascular endothelium. Nutrition, including fish oil-derived long-chain omega-3 fatty acids, such as docosahexaenoic acid (DHA, 22:6?-3), can reduce inflammation and thus the risk of atherosclerosis. We tested the hypothesis that cyclopentenone metabolites produced by oxidation of DHA can protect against PCB-induced endothelial cell dysfunction. Oxidized DHA (oxDHA) was prepared by incubation of the fatty acid with the free radical generator 2,2-azo-bis(2-amidinopropane) dihydrochloride (AAPH). Cellular pretreatment with oxDHA prevented production of superoxide induced by PCB77, and subsequent activation of nuclear factor-?B (NF-?B). A4/J4-neuroprostanes (NPs) were identified and quantitated using HPLC ESI tandem mass spectrometry. Levels of these NPs were markedly increased after DHA oxidation with AAPH.. The protective actions of oxDHA were reversed by treatment with sodium borohydride (NaBH4), which concurrently abrogated A4/J4-NP formation. Up-regulation of monocyte chemoattractant protein-1 (MCP-1)by PCB77 was markedly reduced by oxDHA, but not by un-oxidized DHA. These protective effects were proportional to the abundance of A4/J4NPs in the oxidized DHA sample. Treatment of cells with oxidized eicosapentaenoic acid (EPA, 20:5?-3) also reduced MCP-1 expression, but less than oxDHA. Treatment with DHA-derived cyclopentenones also increased DNA binding of NF-E2-related factor-2 (Nrf2)and downstream expression of NAD(P)H:quinone oxidoreductase (NQO1), similarly to the Nrf-2 activator sulforaphane. Furthermore, sulforaphane prevented PCB77-induced MCP-1 expression, suggesting that activation of Nrf-2 mediates the observed protection against PCB77 toxicity. Our data implicate A4/J4-NPs as mediators of omega-3 fatty acid-mediated protection against the endothelial toxicity of coplanar PCBs.

Majkova, Zuzana; Layne, Joseph; Sunkara, Manjula; Morris, Andrew J.; Toborek, Michal; Hennig, Bernhard

2011-01-01

336

Omega-3 fatty acid oxidation products prevent vascular endothelial cell activation by coplanar polychlorinated biphenyls  

SciTech Connect

Coplanar polychlorinated biphenyls (PCBs) may facilitate development of atherosclerosis by stimulating pro-inflammatory pathways in the vascular endothelium. Nutrition, including fish oil-derived long-chain omega-3 fatty acids, such as docosahexaenoic acid (DHA, 22:6{omega}-3), can reduce inflammation and thus the risk of atherosclerosis. We tested the hypothesis that cyclopentenone metabolites produced by oxidation of DHA can protect against PCB-induced endothelial cell dysfunction. Oxidized DHA (oxDHA) was prepared by incubation of the fatty acid with the free radical generator 2,2-azo-bis(2-amidinopropane) dihydrochloride (AAPH). Cellular pretreatment with oxDHA prevented production of superoxide induced by PCB77, and subsequent activation of nuclear factor-{kappa}B (NF-{kappa}B). A{sub 4}/J{sub 4}-neuroprostanes (NPs) were identified and quantitated using HPLC ESI tandem mass spectrometry. Levels of these NPs were markedly increased after DHA oxidation with AAPH. The protective actions of oxDHA were reversed by treatment with sodium borohydride (NaBH{sub 4}), which concurrently abrogated A{sub 4}/J{sub 4}-NP formation. Up-regulation of monocyte chemoattractant protein-1 (MCP-1) by PCB77 was markedly reduced by oxDHA, but not by un-oxidized DHA. These protective effects were proportional to the abundance of A{sub 4}/J{sub 4} NPs in the oxidized DHA sample. Treatment of cells with oxidized eicosapentaenoic acid (EPA, 20:5{omega}-3) also reduced MCP-1 expression, but less than oxDHA. Treatment with DHA-derived cyclopentenones also increased DNA binding of NF-E2-related factor-2 (Nrf2) and downstream expression of NAD(P)H:quinone oxidoreductase (NQO1), similarly to the Nrf-2 activator sulforaphane. Furthermore, sulforaphane prevented PCB77-induced MCP-1 expression, suggesting that activation of Nrf-2 mediates the observed protection against PCB77 toxicity. Our data implicate A{sub 4}/J{sub 4}-NPs as mediators of omega-3 fatty acid-mediated protection against the endothelial toxicity of coplanar PCBs.

Majkova, Zuzana [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536-0200 (United States); Layne, Joseph [Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40536-0200 (United States); Sunkara, Manjula; Morris, Andrew J. [Division of Cardiovascular Medicine, The Gill Heart Institute, University of Kentucky, Lexington, KY 40536-0509 (United States); Toborek, Michal [Department of Neurosurgery, University of Kentucky, Lexington, KY 40536-0200 (United States); Hennig, Bernhard, E-mail: bhennig@email.uky.edu [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536-0200 (United States); Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40536-0200 (United States); Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40536-0200 (United States)

2011-02-15

337

Nucleic Acid Polymers Prevent the Establishment of Duck Hepatitis B Virus Infection In Vivo  

PubMed Central

Nucleic acid polymers (NAPs) are novel, broad-spectrum antiviral compounds that use the sequence-independent properties of phosphorothioate oligonucleotides (PS-ONs) as amphipathic polymers to block amphipathic interactions involved in viral entry. Using the duck hepatitis B virus (DHBV) model of human hepatitis B virus infection, NAPs have been shown to have both entry and postentry antiviral activity against DHBV infection in vitro in primary duck hepatocytes (PDH). In the current study, various NAPs were assessed for their prophylactic activity in vivo against DHBV infection in ducks. The degenerate NAP REP 2006 prevented the development of widespread and persistent DHBV infection in 14-day-old ducks, while the acidic-pH-sensitive NAP REP 2031 had little or no prophylactic effect. REP 2006 displayed significant toxicity in ducks, which was attributed to CpG-mediated proinflammation, while REP 2031 (which has no CpG motifs) displayed no toxicity. A third NAP, REP 2055, which was designed to retain amphipathic activity at acidic pH and contained no CpG motifs, was well tolerated and displayed prophylactic activity against DHBV infection at doses as low as 1 mg/kg of body weight/day. These studies suggest that NAPs can be easily and predictably tailored to retain anti-DHBV activity and to have minimal toxic effects in vivo. Future studies are planned to establish the therapeutic efficacy of NAPs against persistent DHBV infection.

Noordeen, Faseeha

2013-01-01

338

Effect of Dietary Calcium Lactate and Lactic Acid on Fæcal Escherichia coli Counts in Pigs  

Microsoft Academic Search

CERTAIN strains of E. coli have been isolated1 from pigs which have died from bowel oedema. Strains of the same organism are involved2 in certain baby pig scours. It has been reported3, in investigations of the intestinal flora of growing\\/fattening pigs, that the count of E. coli was inversely related to those of lactic acid producing bacteria, chiefly Lactobacillus bifidus.

G. S. Burnett

1963-01-01

339

Tauroursodeoxycholic Acid Protects Cholestasis in Rat Reperfused Livers (Its Roles in Hepatic Calcium Mobilization)  

Microsoft Academic Search

Tauroursodeoxycholic acid (TUDCA) is ofpotential benefit in cholestatic disorders. However, theeffect of TUDCA on hepatic ischemia-reperfusion injuryis unknown. We studied this subject with particular regard to its roles in hepatic calciummobilization. Three doses of TUDCA were used withcontinuous intravenous infusion (1.0, 0.1, and 0.01mumol\\/kg body weight\\/min). At 3 hr after 1 hr ofischemia and reperfusion in 70% rat liver, high-dose

Takashi Ono; Katsuyuki Imai; Hitoshi Kohno; Masaaki Uchida; Yoshinari Takemoto; Dipok Kumar Dhar; Naofumi Nagasue

1998-01-01

340

Ursolic Acid Inhibits Na+/K+-ATPase Activity and Prevents TNF-?-Induced Gene Expression by Blocking Amino Acid Transport and Cellular Protein Synthesis.  

PubMed

Pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-?, induce the expression of a wide variety of genes, including intercellular adhesion molecule-1 (ICAM-1). Ursolic acid (3?-hydroxy-urs-12-en-28-oic acid) was identified to inhibit the cell-surface ICAM-1 expression induced by pro-inflammatory cytokines in human lung carcinoma A549 cells. Ursolic acid was found to inhibit the TNF-?-induced ICAM-1 protein expression almost completely, whereas the TNF-?-induced ICAM-1 mRNA expression and NF-?B signaling pathway were decreased only partially by ursolic acid. In line with these findings, ursolic acid prevented cellular protein synthesis as well as amino acid uptake, but did not obviously affect nucleoside uptake and the subsequent DNA/RNA syntheses. This inhibitory profile of ursolic acid was similar to that of the Na+/K+-ATPase inhibitor, ouabain, but not the translation inhibitor, cycloheximide. Consistent with this notion, ursolic acid was found to inhibit the catalytic activity of Na+/K+-ATPase. Thus, our present study reveals a novel molecular mechanism in which ursolic acid inhibits Na+/K+-ATPase activity and prevents the TNF-?-induced gene expression by blocking amino acid transport and cellular protein synthesis. PMID:24970122

Yokomichi, Tomonobu; Morimoto, Kyoko; Oshima, Nana; Yamada, Yuriko; Fu, Liwei; Taketani, Shigeru; Ando, Masayoshi; Kataoka, Takao

2011-01-01

341

Ursolic Acid Inhibits Na+/K+-ATPase Activity and Prevents TNF-?-Induced Gene Expression by Blocking Amino Acid Transport and Cellular Protein Synthesis  

PubMed Central

Pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-?, induce the expression of a wide variety of genes, including intercellular adhesion molecule-1 (ICAM-1). Ursolic acid (3?-hydroxy-urs-12-en-28-oic acid) was identified to inhibit the cell-surface ICAM-1 expression induced by pro-inflammatory cytokines in human lung carcinoma A549 cells. Ursolic acid was found to inhibit the TNF-?-induced ICAM-1 protein expression almost completely, whereas the TNF-?-induced ICAM-1 mRNA expression and NF-?B signaling pathway were decreased only partially by ursolic acid. In line with these findings, ursolic acid prevented cellular protein synthesis as well as amino acid uptake, but did not obviously affect nucleoside uptake and the subsequent DNA/RNA syntheses. This inhibitory profile of ursolic acid was similar to that of the Na+/K+-ATPase inhibitor, ouabain, but not the translation inhibitor, cycloheximide. Consistent with this notion, ursolic acid was found to inhibit the catalytic activity of Na+/K+-ATPase. Thus, our present study reveals a novel molecular mechanism in which ursolic acid inhibits Na+/K+-ATPase activity and prevents the TNF-?-induced gene expression by blocking amino acid transport and cellular protein synthesis.

Yokomichi, Tomonobu; Morimoto, Kyoko; Oshima, Nana; Yamada, Yuriko; Fu, Liwei; Taketani, Shigeru; Ando, Masayoshi; Kataoka, Takao

2011-01-01

342

Physiological and toxicological effects of long-term exposure to acid, aluminum, and low calcium on adult brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri)  

SciTech Connect

Although the toxic effects of these three parameters were highly interactive, survival and growth of adult brook trout were reduced at elevated aluminum concentrations. Only 40 ug/L aluminum was necessary to produce similar responses in rainbow trout. Neither species was sensitive to pH alone in the range 4.5-6.5 except at very low calcium concentrations. Reductions in fecundity were observed, but only as a result of decreased growth. Progeny spawned from brook trout that had been exposed to 0.5 mg/L calcium were more sensitive to continued exposure to acid, aluminum and low calcium than were progeny of control fish. Physiologically, brook and rainbow trout responded similarly to sublethal acid, aluminum and low calcium stress. All fish exposed to depressed pH showed reductions in plasma sodium, but in most cases they were able to maintain normal plasma osmolality. But those fish stressed most severely displayed an entire suite of disturbances, including decreased survival, growth and feeding, as well as abnormal vitellogenesis and ionoregulatory failure.

Mount, D.R.

1987-01-01

343

Specific amino acids in the BAR domain allow homodimerization and prevent heterodimerization of sorting nexin 33.  

PubMed

SNX33 (sorting nexin 33) is a homologue of the endocytic protein SNX9 and has been implicated in actin polymerization and the endocytosis of the amyloid precursor protein. SNX33 belongs to the large family of BAR (Bin/amphiphysin/Rvs) domain-containing proteins, which alter cellular protein trafficking by modulating cellular membranes and the cytoskeleton. Some BAR domains engage in homodimerization, whereas other BAR domains also mediate heterodimerization between different BAR domain-containing proteins. The molecular basis for this difference is not yet understood. Using co-immunoprecipitations we report that SNX33 forms homodimers, but not heterodimers, with other BAR domain-containing proteins, such as SNX9. Domain deletion analysis revealed that the BAR domain, but not the SH3 (Src homology 3) domain, was required for homodimerization of SNX33. Additionally, the BAR domain prevented the heterodimerization between SNX9 and SNX33, as determined by domain swap experiments. Molecular modelling of the SNX33 BAR domain structure revealed that key amino acids located at the BAR domain dimer interface of the SNX9 homodimer are not conserved in SNX33. Replacing these amino acids in SNX9 with the corresponding amino acids of SNX33 allowed the mutant SNX9 to heterodimerize with SNX33. Taken together, the present study identifies critical amino acids within the BAR domains of SNX9 and SNX33 as determinants for the specificity of BAR domain-mediated interactions and suggests that SNX9 and SNX33 have distinct molecular functions. PMID:20964629

Dislich, Bastian; Than, Manuel E; Lichtenthaler, Stefan F

2011-01-01

344

?-3 fatty acids in the prevention of cognitive decline in humans.  

PubMed

The brain is a lipid-rich organ where docosahexaenoic acid (DHA) is enriched and where eicosapentaenoic acid (EPA) may have anti-inflammatory effects. The potential role for n-3 (?-3) fatty acids such as DHA and EPA in the prevention of cognitive decline, including Alzheimer's disease (AD) has attracted major interest for the past 20 y. This review presents our understanding of recent observational, interventional, and experimental studies, with the aim of providing some answers to the following question: Can n-3 FA intake modulate cognitive function during aging? In longitudinal observation studies we mainly observe inverse relations between fish intake or serum concentrations of DHA and cognitive impairment. Intervention studies of EPA and DHA supplementation in healthy old individuals have been negative so far (i.e., after up to 2 years of treatment, no differences in cognitive decline between treated and nontreated participants have been observed). In studies that provided EPA and DHA to adults with mild cognitive impairment or age-related cognitive impairment the data seem to be positive. However, when patients with established AD were supplemented with EPA and DHA it appears no benefit was gained. For studies on healthy individuals, a major concern is that the treatment periods may have been too short. There might also be subgroup effects because of the carriage of apolipoprotein E?4 alleles or risk factor burden. Experimental studies appear to be consistently positive (i.e., n-3 FA supplementation in rodents over a substantial portion of their lives reduces amyloid-? deposition and hippocampal neuron loss and improves cognitive functioning). We are getting closer to providing evidence-based recommendations on fish and fish oil intake to facilitate memory function during old age. In the meantime it is advised to follow the general CDC dietary recommendations of 2-3 fish meals per week or the equivalent intake of long chain n-3 fatty acids, particularly DHA. PMID:24228198

Cederholm, Tommy; Salem, Norman; Palmblad, Jan

2013-11-01

345

Zoledronic acid prevents loss of trabecular bone after focal irradiation in mice.  

PubMed

Radiation therapy for soft tissue sarcomas and metastatic disease can adversely affect bone, leading to late-onset fragility fractures. Adjunct administration of bisphosphonates has been postulated as means of minimizing these adverse effects. Using a murine model of focal hindlimb irradiation, we examined the potential for zoledronic acid treatment to minimize the deleterious effects of localized radiotherapy (RTx) on bone. Mice received a single, unilateral hindlimb exposure of 20 Gy. Beginning 4 days prior to irradiation, and at 1, 2 and 3 weeks post-irradiation, animals were treated with zoledronic acid or saline/vehicle injections. Areal bone mineral density was assessed at 4 days, and 2, 4 and 12 weeks post-irradiation by dual-energy X-ray absorptiometry (DXA). Micro-computed tomography and axial compression testing were used to quantify changes in morphological and mechanical properties of femurs at 4 and 12 weeks post-irradiation. Radiation had differential effects on cortical and trabecular bone, increasing cortical bone mineral content (BMC), cortical bone volume (BV) and trabecular separation (Tb.Sp) while decreasing trabecular number (Tb.N) by 12 weeks after localized radiotherapy. Administration of zoledronic acid increased hindlimb areal bone mineral density in both the presence and absence of radiotherapy, increased cortical bone mineral content and bone volume, increased trabecular bone volume (BV/TV), increased trabecular number, increased trabecular thickness (Tb.Th), and decreased trabecular separation compared to irradiated and vehicle control femurs. Despite these improvements in morphology with zoledronic acid, no biomechanical advantage was observed. Further work is needed to define the role of bisphosphonates in prevention of post-irradiation fragility fractures. PMID:23772924

Keenawinna, Lihini; Oest, Megan E; Mann, Kenneth A; Spadaro, Joseph; Damron, Timothy A

2013-07-01

346

Mechanism and energetics by which glutamic acid 242 prevents leaks in cytochrome c oxidase.  

PubMed

Cytochrome c oxidase (CcO) is the terminal enzyme of aerobic respiration. The energy released from the reduction of molecular oxygen to water is used to pump protons across the mitochondrial or bacterial membrane. The pump function introduces a mechanistic requirement of a valve that prevents protons from flowing backwards during the process. It was recently found that Glu-242, a key amino acid in transferring protons to be pumped across the membrane and to the site of oxygen reduction, fulfils the function of such a valve by preventing simultaneous contact to the pump site and to the proton-conducting D-channel (Kaila V.R.I. et al. Proc. Natl. Acad. Sci. USA 105, 2008). Here we have incorporated the valve model into the framework of the reaction mechanism. The function of the Glu valve is studied by exploring how the redox state of the surrounding metal centers, dielectric effects, and membrane potential, affects the energetics and leaks of this valve. Parallels are drawn between the dynamics of Glu-242 and the long-standing obscure difference between the metastable O(H) and stable O states of the binuclear center. Our model provides a suggestion for why reduction of the former state is coupled to proton translocation while reduction of the latter is not. PMID:19406098

Kaila, Ville R I; Verkhovsky, Michael I; Hummer, Gerhard; Wikström, Mårten

2009-10-01

347

Oral administration of acidic xylooligosaccharides prevents the development of atopic dermatitis-like skin lesions in NC/Nga mice.  

PubMed

We examined whether two types of xylooligosaccharides (neutral or acidic xylooligosaccharides) derived from hardwood kraft pulp ameliorate the development of atopic dermatitis (AD)-like skin lesions induced by repeated application of picryl chloride (PiCl) in NC/Nga mice. Oral administration of acidic xylooligosaccharides at a daily dose of 100 mg/kg significantly prevented the development of AD-like skin lesions. Serum histamine level was significantly suppressed, but serum total IgE level was not significantly suppressed. Moreover, the secretion of inflammatory cytokine IL-12 from splenic lymphocytes was significantly suppressed. On the other hand, neutral xylooligosaccharides showed no significant preventive effect on the development of AD-like symptoms. These results suggest that oral administration of acidic xylooligosaccharides may be effective in preventing the development of AD-like skin disease and one of the mechanisms is the suppressive effect on IL-12. PMID:20354347

Ohbuchi, Takayuki; Sakaino, Makoto; Takahashi, Tetsunari; Azumi, Naoya; Ishikawa, Kotaro; Kawazoe, Sadahiro; Kobayashi, Yukiko; Kido, Yasuhiro

2010-01-01

348

Preparation and characteristics of nano-grained calcium phosphate coatings on titanium from ultrasonated bath at acidic pH.  

PubMed

Electrochemically deposited nano-grained calcium phosphate coatings were produced on titanium substrates using aqueous electrolyte at acidic pH. Different coatings were produced by using cathodic current densities ranging from 10 to 50 mA/cm(2) from an ultrasonated electrolytic bath. These coatings contained dicalcium phosphate dihydrate as the predominant phase and hydroxyapatite as the minor phase. With increasing current density, hydroxyapatite content in the coatings increased. Dicalcium phosphate grains had size in the range of 55-85 nm and hydroxyapatite had grains in the size range of 20-25 nm. Scanning electron microscopy showed that the morphology of the coatings obtained at lower current densities had acicular structure. With increasing current densities, the needles became blunt and small and finally, at 50 mA/cm(2) the coating had globular deposits. Surface roughness of the coatings also increased with increasing deposition current density. Tensile bond strengths of the coatings were in the range of 3.6-6.9 MPa and decreased with increase of deposition current density. Heat-treatment of the coatings for 2 h at 500 degrees C completely eliminated the dicalcium phosphate phase and resulted in mono hydroxyapatite phase containing grains in the size range of 20-30 nm. PMID:17854064

Narayanan, R; Kwon, Tae-Yub; Kim, Kyo-Han

2008-04-01

349

Surface modification of superparamagnetic iron nanoparticles with calcium salt of poly({gamma}-glutamic acid) as coating material  

SciTech Connect

Surface-modified magnetite nanoparticles (MNPs) were synthesized by co-precipitation of aqueous solution of ferrous and ferric salts (molar ratio 1:2) upon adding a base followed by calcium salt of poly({gamma}-glutamic acid) (Ca-{gamma}-PGA) for uniform coating on the surface of MNPs. Both uncoated and Ca-{gamma}-PGA-coated MNPs were characterized using various techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and vibrating sample magnetometric (VSM) studies. Compared with bare MNPs, the IR spectra of coated MNPs showed characteristic peaks of {gamma}-PGA, implying the {gamma}-PGA coating on MNPs did occur. The TEM images depicted an average size of 8-10 nm for bare MNPs and 14 nm for coated MNPs, with their shape being spherical in nature. In the presence of applied magnetic field, a superparamagnetic behavior was observed at room temperature for both bare and Ca-{gamma}-PGA-coated MNPs, with no magnetism left upon magnetic-field removal.

Kumar, Ramesh; Inbaraj, B. Stephen [Department of Food Science, Fu Jen University, Taipei 242, Taiwan (China)] [Department of Food Science, Fu Jen University, Taipei 242, Taiwan (China); Chen, B.H., E-mail: 002622@mail.fju.edu.tw [Department of Food Science, Fu Jen University, Taipei 242, Taiwan (China); Graduate Institute of Medicine, Fu Jen University, Taipei 242, Taiwan (China)

2010-11-15

350

Calcium phenylphosphonate as a host for 4-aminobenzoic acid-Synthesis, characterization, and cation adsorption from ethanol solution  

SciTech Connect

Crystalline lamellar calcium phenylphosphonate retained 4-aminobenzoic acid inside its cavity without leaching. The intense infrared bands in the 1160-695 cm{sup -1} interval confirmed the presence of the phosphonate groups attached to the inorganic layer, with sharp and intense peaks in X-ray diffraction patterns, which gave basal distances of 1532 and 1751 pm for the original and the intercalated compounds, respectively. The thermogravimetric curves of both layered compounds showed the release of water molecules and the organic moiety in distinct stages, to yield a final Ca(PO{sub 3}){sub 2} residue. Solid-state {sup 31}P nuclear magnetic resonance spectra presented only one peak for the phenylphosphonate groups attached to the main inorganic polymeric structure near 12.4 ppm. The adsorption isotherms from ethanol gave the maximum adsorption capacities of 1.68 and 0.50 mmol g{sup -1} for copper and cobalt, respectively, whose average stability constants followed Co > Cu; the number of ligands was determined as four for both cations.

Lazarin, Angelica M., E-mail: amlazarin2@uem.br [Departamento de Quimica, Universidade Estadual de Maringa, Av. Colombo, 5790, 87020-900 Maringa, PR (Brazil); Ganzerli, Thiago A.; Sernaglia, Rosana L.; Andreotti, Elza I.S. [Departamento de Quimica, Universidade Estadual de Maringa, Av. Colombo, 5790, 87020-900 Maringa, PR (Brazil); Airoldi, Claudio [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP (Brazil)

2009-11-15

351

A combination of biphasic calcium phosphate scaffold with hyaluronic Acid-gelatin hydrogel as a new tool for bone regeneration.  

PubMed

A novel bone substitute was fabricated to enhance bone healing by combining ceramic and polymer materials. In this study, Hyaluronic acid (HyA)-Gelatin (Gel) hydrogel was loaded into a biphasic calcium phosphate (BCP) ceramic, and the resulting scaffold, with unique micro- and macroporous orientation, was evaluated for bone regeneration applications. The fabricated scaffold showed high interconnected porosity, with an average compressive strength of 2.8±0.15?MPa, which is usually recommended for cancellous bone substitution. In vitro cytocompatibility studies were conducted using bone marrow mesenchymal stem cells. The HyA-Gel-loaded BCP scaffold resulted in a significant increase in cell proliferation at 3 (p<0.05) and 7 days (p<0.001) and high alkaline phosphatase activities at 14 and 21 days. Furthermore, the in vivo studies showed that the implanted HyA-Gel-loaded BCP scaffold begins to degrade within 3 months after implantation. Histological sections also confirmed a rapid new bone formation and a high rate of collagen mineralization. A bone matrix formation was confirmed by positive immunohistochemistry staining of osteopontin, osteocalcin, and collagen type I. In vivo expression of extracellular matrix proteins demonstrated that this novel bone substitute holds great promise for use in stimulating new bone regeneration. PMID:24517159

Nguyen, Thuy Ba Linh; Lee, Byong-Taek

2014-07-01

352

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

353

Calcium-dependent protein kinases, CDPK4 and CDPK5, affect early steps of jasmonic acid biosynthesis in Nicotiana attenuata.  

PubMed

Calcium-dependent protein kinases (CDPKs) modulate plant development and growth and are important regulators of biotic and abiotic stress responses. Recently it was found that simultaneously silencing Nicotiana attenuata NaCDPK4 and NaCDPK5 (IRcdpk4/5 plants) results in accumulation of exceptionally high JA levels after wounding or simulated herbivory treatments, which in turn induced high levels of defense metabolites that slowed the growth of Manduca sexta, a specialist insect herbivore. To investigate the mechanism by which NaCDPK4 and NaCDPK5 regulate JA accumulation, we analyzed the transcript levels of all important enzymes involved in JA biosynthesis, but these genes showed no differences between wild-type and IRcdpk4/5 plants. Moreover, the dynamics of JA were similar between these plants, excluding the possibility of decreased degradation rates in IRcdpk4/5 plants. To gain insight into the mechanism by which NaCDPK4 and NaCDPK5 regulate JA biosynthesis, free fatty acids, including C18:3, and (9S,13S)-12-oxo-phytodienoic acid (OPDA), two important precursors of JA were quantified at different times before and after wounding and simulated herbivore feeding treatments. We show that after these treatments, IRcdpk4/5 plants have decreased levels of C18:3, but have enhanced OPDA and JA levels, suggesting that NaCDPK4 and NaCDPK5 have a role in the early steps of JA biosynthesis. The possible role of NaCDPK4 and NaCDPK5 regulating AOS and AOC enzymatic activity is discussed. PMID:23221744

Hettenhausen, Christian; Yang, Da-Hai; Baldwin, Ian T; Wu, Jianqiang

2013-01-01

354

EE-drospirenone-levomefolate calcium versus EE-drospirenone + folic acid: folate status during 24 weeks of treatment and over 20 weeks following treatment cessation  

PubMed Central

Background Adequate folate supplementation in the periconceptional phase is recommended to reduce the risk of neural tube defects. Oral contraceptives may provide a reasonable delivery vehicle for folate supplementation before conception in women of childbearing potential. This study aimed to demonstrate that a fixed-dose combination of an oral contraceptive and levomefolate calcium leads to sustainable improvements in folate status compared with an oral contraceptive + folic acid. Methods This was a double-blind, randomized, parallel-group study in which 172 healthy women aged 18–40 years received ethinylestradiol (EE)-drospirenone-levomefolate calcium or EE-drospirenone + folic acid for 24 weeks (invasion phase), and EE-drospirenone for an additional 20 weeks (folate elimination phase). The main objective of the invasion phase was to examine the area under the folate concentration time-curve for plasma and red blood cell (RBC) folate, while the main objective of the elimination phase was to determine the duration of time for which RBC folate concentration remained ? 906 nmol/L after cessation of EE-drospirenone-levomefolate calcium. Results Mean concentration-time curves for plasma folate, RBC folate, and homocysteine were comparable between treatment groups during both study phases. During the invasion phase, plasma and RBC folate concentrations increased and approached steady-state after about 8 weeks (plasma) or 24 weeks (RBC). After cessation of treatment with levomefolate calcium, folate concentrations decreased slowly. The median time to RBC folate concentrations falling below 906 nmol/L was 10 weeks (95% confidence interval 8–12 weeks) after cessation of EE-drospirenone-levomefolate calcium treatment. Plasma and RBC folate levels remained above baseline values in 41.3% and 89.3% of women, respectively, at the end of the 20-week elimination phase. Conclusion Improvements in folate status were comparable between EE-drospirenone-levomefolate calcium and EE-drospirenone + folic acid. Plasma and RBC folate levels remained elevated for several months following cessation of treatment with EE-drospirenone-levomefolate calcium.

Diefenbach, Konstanze; Trummer, Dietmar; Ebert, Frank; Lissy, Michael; Koch, Manuela; Rohde, Beate; Blode, Hartmut

2013-01-01

355

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

2013-01-01

356

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

MedlinePLUS

... the 5 May 2009 issue of Annals of Internal Medicine (volume 150, pages 626-631 and pages 632- ... by eating folic acid–forti?ed food. Annals of Internal Medicine Summaries for Patients I-50© 2009 American College ...

357

gamma-Aminobutyric acid (A) receptor agonists accelerate cutaneous barrier recovery and prevent epidermal hyperplasia induced by barrier disruption.  

PubMed

gamma-Aminobutyric acid, is an amino acid transmitter, which mediates rapid inhibition in the central nervous system. gamma-Aminobutyric acid (A) receptor is a ligand-gated chloride ion channel playing an important part in polarizing the cell membrane and reducing neuronal excitability in the neuron. In this study, we demonstrated the effects of gamma-aminobutyric acid (A) receptor agonists on the cutaneous barrier repair process after the barrier disruption of hairless mice. Topical application of gamma-aminobutyric acid and gamma-aminobutyric acid (A) receptor-specific agonists, musimol and isoguvacine, after barrier disruption accelerated the barrier recovery. The gamma-aminobutyric acid (B)-specific agonist, baclofen, did not affect the barrier recovery rate. The effect of gamma-aminobutyric acid on the barrier recovery was blocked by the gamma-aminobutyric acid (A)-receptor antagonist, bicuculline methobromide, but gamma-aminobutyric acid (B) receptor antagonist, saclofen, did not affect the effect of gamma-aminobutyric acid. Topical application of gamma-aminobutyric acid also prevented epidermal hyperplasia, which was induced by the barrier insults under low environmental humidity and bicuculline methobromide blocked the effect of gamma-aminobutyric acid on the epidermal hyperplasia. Immunoreactivity against gamma-aminobutyric acid (A) polyclonal antibody was observed in hairless mouse epidermis. The fluorescent probe of gamma-aminobutyric acid (A) receptor, TXR-musimol showed the localization of gamma-aminobutyric acid (A) receptor in the epidermis of the hairless mice. Elevation of intracellular chloride ion was induced by gamma-aminobutyric acid in cultured human keratinocytes and it was blocked by bicuculline methobromide. These results suggest that the gamma-aminobutyric acid (A)-like receptor is associated with skin barrier homeostasis and regulation of the receptor clinically effective for barrier dysfunctional or epidermal hyperproliferative diseases. PMID:12445190

Denda, Mitsuhiro; Inoue, Kaori; Inomata, Shinji; Denda, Sumiko

2002-11-01

358

Effect of low-carbohydrate high-protein diets on acid-base balance, stone-forming propensity, and calcium metabolism  

Microsoft Academic Search

Background: Low-carbohydrate high-protein (LCHP) diets are used commonly for weight reduction. This study explores the relationship between such diets and acid-base balance, kidney-stone risk, and calcium and bone metabolism. Methods: Ten healthy subjects participated in a metabolic study. Subjects initially consumed their usual non-weight-reducing diet, then a severely carbohydrate-restricted induction diet for 2 weeks, followed by a moderately carbohydrate-restricted maintenance

Shalini T. Reddy; Chia-Ying Wang; Khashayar Sakhaee; Linda Brinkley; Charles Y. C. Pak

2002-01-01

359

Acid Resistance of Enamel Subsurface Lesions Remineralized by a Sugar-Free Chewing Gum Containing Casein Phosphopeptide-Amorphous Calcium Phosphate  

Microsoft Academic Search

The aim of this clinical study was to investigate the acid resistance of enamel lesions remineralized in situ by a sugar-free chewing gum containing casein phosphopeptide-amorphous calcium phosphate nanocomplexes (CPP-ACP: Recaldent™). The study utilized a double-blind, randomized, crossover design with two treatments: (i) sugar-free gum containing 18.8 mg of CPP-ACP, and (ii) sugar-free gum not containing CPP-ACP as control. Subjects

Y. Iijima; F. Cai; P. Shen; G. Walker; C. Reynolds; E. C. Reynolds

2004-01-01

360

The effect of dietary supplementation with calcium salts of long chain fatty acids and\\/or l-carnitine on ovarian activity of Rahmani ewes  

Microsoft Academic Search

This study investigated the effect of dietary supplementation with calcium salts of long chain fatty acids with or without of l-carnitine on ovarian activity using 24 Rahmani ewes randomly allocated to four treatments. Control animals (n=6) were fed a basal diet of hay (64.2%) and barley grain (35.0%) plus minerals and vitamins (0.8%). Ewes on the three treatments received the

K. H. El-Shahat; Amal M. Abo-El maaty

2010-01-01

361

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

362

Comparative study of the use of poly(glycolic acid), calcium alginate and pluronics in the engineering of autologous porcine cartilage  

Microsoft Academic Search

New cartilage formation has been successfully achieved by a technology referred to as tissue engineering. Polymers and hydrogels such as poly(glycolic acid), calcium alginate, and poly(ethylene) and poly(propylene) hydrogels have been used as cell carriers to regenerate cartilage in the nude mouse model. The next step toward human applications of engineered cartilage is to demonstrate their potential in immunocompetent animal

Yilin Cao; Angela Rodriguez; Martin Vacanti; Clemente Ibarra; Carlos Arevalo; Charles A. Vacanti

1998-01-01

363

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

364

The effects of taurochenodeoxycholic acid in preventing pulmonary fibrosis in mice.  

PubMed

The present study prepared the pulmonary fibrosis model in mice by using Bleomycin and carry out the investigations on the effects of taurochenodeoxycholic acid (TCDCA) in preventing pulmonary fibrosis in mice. Expression profiles of the bile acid receptors in the lung of mice FXR? and TGR5 were examined, and pulmonary coefficient, pathohistology as well as expression of TNF-?, MMP-2, MMP-9 and TIMP-2 in pulmonary fibrosis mice. The results showed that FXR? and TGR5 simultaneously expressed in the lung of the mice; TCDCA in dosages of 0.05 and 0.1g/kg can extremely significantly decrease the pulmonary coefficient in the model mice (P>0.01), TCDCA in a dosage of 0.2g/kg significantly decreased the pulmonary coefficient in the model mice (P<0.05); TCDCA in dosages of 0.05 and 0.1g/kg significantly reduce the pathological damages on their lungs; TCDCA can extremely significantly decrease the expression levels of TNF-? and TIMP-2 in pulmonary tissues in the pulmonary fibrosis mice (P>0.01), the expression level of MMP-9 extremely significantly increased (P>0.01), while it has no significant effects on MMP2. The results as mentioned above indicated that TCDCA had antagonistic actions on pulmonary fibrosis in mice. PMID:23811455

Zhou, Chuan; Shi, Youfei; Li, Jinlian; Zhang, Wen; Wang, Yanmin; Liu, Yan; Liu, Jianzhu

2013-07-01

365

Gallic acid prevents memory deficits and oxidative stress induced by intracerebroventricular injection of streptozotocin in rats.  

PubMed

In the present study, we evaluated the effects of gallic acid (GA; 30 mg/kg, orally, once daily for 26 days starting from day 5 prior to streptozotocin injection) on cognitive impairment and cerebral oxidative stress induced by intracerebroventricular-streptozotocin (ICV-STZ; bilaterally, two doses of 3 mg/kg) injection as an animal model of sporadic Alzheimers type (SDAT) in rats. The results showed that ICV-STZ-injection reduced the passive avoidance and spatial memory performance associated with decreased non-enzymatic [total thiol concentration, -58.5%, -50.7%] and enzymatic [superoxide dismutase (SOD, -30.2%, -32.9%), catalase (CAT, -43.5%, -50.7%), glutathione peroxidase (GPx, -57.1%, -61.7%)] activities and increased the level of thio-barbituric acid reactive species (TBARS, +103.5%, +82.5%) in the hippocampus and cerebral cortex, respectively. In contrast, chronic administration of GA significantly prevented cognitive deficits and biochemical alterations in the ICV-STZ rats. These findings highlight the beneficial role of GA in the ICV-STZ rats via enhancement of cerebral antioxidant defense system. Thus, it may have a therapeutic value for the treatment of SDAT. PMID:24036471

Mansouri, Mohammad Taghi; Naghizadeh, Bahareh; Ghorbanzadeh, Behnam; Farbood, Yaghoub; Sarkaki, Alireza; Bavarsad, Kowsar

2013-10-01

366

Ferulic acid prevents liver injury and increases the anti-tumor effect of diosbulbin B in vivo.  

PubMed

The present study is designed to investigate the protection by ferulic acid against the hepatotoxicity induced by diosbulbin B and its possible mechanism, and further observe whether ferulic acid augments diosbulbin B-induced anti-tumor activity. The results show that ferulic acid decreases diosbulbin B-increased serum alanine transaminase/aspartate transaminase (ALT/AST) levels. Ferulic acid also decreases lipid peroxide (LPO) levels which are elevated in diosbulbin B-treated mice. Histological evaluation of the liver demonstrates hydropic degeneration in diosbulbin B-treated mice, while ferulic acid reverses this injury. Moreover, the activities of copper- and zinc-containing superoxide dismutase (CuZn-SOD) and catalase (CAT) are decreased in the livers of diosbulbin B-treated mice, while ferulic acid reverses these decreases. Further results demonstrate that the mRNA expressions of CuZn-SOD and CAT in diosbulbin B-treated mouse liver are significantly decreased, while ferulic acid prevents this decrease. In addition, ferulic acid also augments diosbulbin B-induced tumor growth inhibition compared with diosbulbin B alone. Taken together, the present study shows that ferulic acid prevents diosbulbin B-induced liver injury via ameliorating diosbulbin B-induced liver oxidative stress injury and augments diosbulbin B-induced anti-tumor activity. PMID:24903991

Wang, Jun-Ming; Sheng, Yu-Chen; Ji, Li-Li; Wang, Zheng-Tao

2014-06-01

367

Decrease in calcium concentration triggers neuronal retinoic acid synthesis during homeostatic synaptic plasticity  

PubMed Central

Blockade of synaptic activity induces homeostatic plasticity, in part by stimulating synthesis of all-trans retinoic acid (RA), which in turn increases AMPA receptor synthesis. However, the synaptic signal that triggers RA synthesis remained unknown. Using multiple activity-blockade protocols that induce homeostatic synaptic plasticity, here we show that RA synthesis is activated whenever postsynaptic Ca2+-entry is significantly decreased, and that RA is required for up-regulation of synaptic strength under these homeostatic plasticity conditions, suggesting that Ca2+ plays an inhibitory role in RA synthesis. Consistent with this notion, we demonstrate that both transient Ca2+-depletion by membrane-permeable Ca2+-chelators and chronic blockage of L-type Ca2+-channels induces RA synthesis. Moreover, the source of dendritic Ca2+ entry that regulates RA synthesis is not specific as mild depolarization with KCl is sufficient to reverse synaptic scaling induced by L-type Ca2+-channel blocker. By expression of a dihydropyridine-insensitive L-type Ca2+-channel, we further show that RA acts cell-autonomously to modulate synaptic transmission. Our findings suggest that in synaptically active neurons, modest ‘basal’ levels of postsynaptic Ca2+ physiologically suppress RA synthesis, whereas in synaptically inactive neurons, decreases in the resting Ca2+-levels induce homeostatic plasticity, by stimulating synthesis of RA that then acts in a cell-autonomous fashion to increase AMPA receptor function.

Wang, Hui-Li; Zhang, Zhenjie; Hintze, Maik; Chen, Lu

2012-01-01

368

Arachidyl amido cholanoic acid (aramchol) is a cholesterol solubilizer and prevents the formation of cholesterol gallstones in inbred mice  

Microsoft Academic Search

We have recently synthesized fatty acid bile acid conjugates (FABAC) that were able to reduce and retard cholesterol crystallization\\u000a in model and human biles. When given orally, they prevented the formation of cholesterol crystals in the bile of hamsters.\\u000a The aim of the present study was to determine whether the FABAC are cholesterol solubilizers, whether they can dissolve pre-existing\\u000a crystals,

Tuvia Gilat; Alicia Leikin-Frenkel; Ilana Goldiner; Hava Laufer; Zamir Halpern; Fred M. Konikoff

2001-01-01

369

In situ cross-linkable hyaluronic acid hydrogels prevent post-operative abdominal adhesions in a rabbit model  

Microsoft Academic Search

We studied the efficacy of an in situ cross-linked hyaluronic acid hydrogel (HAX) in preventing post-surgical peritoneal adhesions, using a rabbit sidewall defect-cecum abrasion model. Two cross-linkable precursors were prepared by modifying hyaluronic acid with adipic dihydrazide and aldehyde, respectively. The hydrogel precursors cross-linked to form a flexible hydrogel upon mixing. The hydrogel was biodegradable and provided a durable physical

Yoon Yeo; Christopher B. Highley; Evangelia Bellas; Taichi Ito; Robert Marini; Robert Langer; Daniel S. Kohane

2006-01-01

370

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

371

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

372

Five year study of etidronate and/or calcium as prevention and treatment for osteoporosis and fractures in patients with asthma receiving long term oral and/or inhaled glucocorticoids  

PubMed Central

Background: Glucocorticoids are associated with a reduction in bone density and an increased risk of fracture. Concurrent treatment with bisphosphonates reduces bone loss and may prevent fractures. A randomised study was performed to determine whether treatment with cyclical etidronate and/or calcium for 5 years prevents fractures or reverses/reduces bone loss in patients receiving glucocorticoid treatment for asthma. Methods: A multicentre, randomised, parallel group comparison of etidronate alone, calcium alone, etidronate + calcium, and no treatment, with stratification according to level of glucocorticoid exposure was carried out in 39 chest clinics in the UK. Three hundred and forty nine postmenopausal female and male outpatients with asthma aged 50–70 years were randomised. The main outcome measures were fractures and changes in bone mineral density (BMD). Results: Overall, 8% of the patients experienced symptomatic fractures and 17.5% developed either a symptomatic fracture and/or a semiquantitative vertebral fracture by the end of 5 years There were no significant differences between the four treatment groups. Comparing etidronate with no etidronate, the rates of new fractures were not significantly different for symptomatic fractures (OR 1.07 (95% CI 0.46 to 2.47)) or for any fractures (OR 0.82 (95% CI 0.45 to 1.47)). For the comparison of calcium with no calcium the corresponding ORs were 1.43 (95% CI 0.62 to 3.33) and 0.91 (95% CI 0.50 to 1.63). In post hoc analysis the effect of etidronate was greater in women than in men (interaction p value 0.02) with the fracture incidence roughly halved (OR 0.39, 95% CI 0.14 to 0.99). Etidronate increased BMD at the lumbar spine by 4.1% (p = 0.001) while calcium had no significant effect. At the proximal femur the effects of treatment were not significant (relative increases etidronate 1.6%; calcium 1.1%). The rate of new fractures in patients with fractures at entry (23.7%) was higher than in those without fractures at entry (14.3%): OR 1.87 (95% CI 1.06 to 3.07). No association was found between change in BMD and new fractures. Conclusions: In patients receiving glucocorticoids for asthma etidronate significantly increased BMD over 5 years at the lumbar spine but not at the hip and had little if any protective effect against fractures, except possibly in postmenopausal women. The effects of calcium were not significant. Combination treatment had no advantage but increased unwanted effects.

Campbell, I; Douglas, J; Francis, R; Prescott, R; Reid, D

2004-01-01

373

Is 5-methyltetrahydrofolate an alternative to folic acid for the prevention of neural tube defects?  

PubMed

Women have higher requirements for folate during pregnancy. An optimal folate status must be achieved before conception and in the first trimester when the neural tube closes. Low maternal folate status is causally related to neural tube defects (NTDs). Many NTDs can be prevented by increasing maternal folate intake in the preconceptional period. Dietary folate is protective, but recommending increasing folate intake is ineffective on a population level particularly during periods of high demands. This is because the recommendations are often not followed or because the bioavailability of food folate is variable. Supplemental folate [folic acid (FA) or 5-methyltetrahydrofolate (5-methylTHF)] can effectively increase folate concentrations to the level that is considered to be protective. FA is a synthetic compound that has no biological functions unless it is reduced to dihydrofolate and tetrahydrofolate. Unmetabolized FA appears in the circulation at doses of >200 ?g. Individuals show wide variations in their ability to reduce FA. Carriers of certain polymorphisms in genes related to folate metabolism or absorption can better benefit from 5-methylTHF instead of FA. 5-MethylTHF [also known as (6S)-5-methylTHF] is the predominant natural form that is readily available for transport and metabolism. In contrast to FA, 5-methylTHF has no tolerable upper intake level and does not mask vitamin B12 deficiency. Supplementation of the natural form, 5-methylTHF, is a better alternative to supplementation of FA, especially in countries not applying a fortification program. Supplemental 5-methylTHF can effectively improve folate biomarkers in young women in early pregnancy in order to prevent NTDs. PMID:23482308

Obeid, Rima; Holzgreve, Wolfgang; Pietrzik, Klaus

2013-09-01

374

Chlorhexidine prevents hypochlorous acid-induced inactivation of alpha1-antitrypsin.  

PubMed

1. Chlorhexidine digluconate has been used as a topical antiseptic in the treatment of acne vulgaris and periodontitis. The acute phase of these diseases involves neutrophilic infiltration. Neutrophil activation and recruitment to inflammatory sites are crucial in both protection against bacterial infection and the induction of hystotoxic damage. Activated neutrophils release several enzymes, including elastase and myeloperoxidase (MPO), which contribute to tissue injury via direct toxic actions, the generation of oxidants and inactivation of protective factors, such as alpha1-antitrypsin (alpha1-AT). In the present study, we investigated whether chlorhexidine can modulate neutrophil-mediated histotoxicity. 2. Human primary neutrophils were isolated from healthy donors. Inactivation of alpha1-AT by neutrophils or hypochlorous acid (HOCl) was evaluated by spectrophotometry and sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis of its capacity to complex with porcine pancreatic elastase (PPE). Neutrophil generation of HOCl, superoxide anion and MPO release were assessed spectrophometrically. 3. Chlorhexidine (0, 0.5, 1, 5 and 10 micromol/L) dose-dependently prevented HOCl-induced inactivation of alpha1-AT and reduced HOCl recovery from phorbol myristate acetate (PMA)-treated human neutrophils, but did not inhibit superoxide anion and MPO release. Chlorhexidine directly inhibited HOCl recovery from neutrophils and HOCl-induced inactivation of alpha1-AT in a cell-free assay. Accordingly, chlorhexidine reversed HOCl-mediated inhibition of alpha1-AT capacity to complex with PPE. 4. These data suggest that chlorhexidine prevents neutrophil-induced alpha1-AT inactivation via a direct inhibitory action on HOCl. Although highly speculative, the present study indicates that chlorhexidine may protect inflamed tissues not only through its antimicrobial properties, but also via a direct anti-inflammatory effect on neutrophil toxic products. PMID:19671069

Montecucco, Fabrizio; Bertolotto, M; Ottonello, L; Pende, A; Dapino, P; Quercioli, A; Mach, F; Dallegri, F

2009-11-01

375

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

376

Biosynthesis of L-Ascorbic Acid and Conversion of Carbons 1 and 2 of L-Ascorbic Acid to Oxalic Acid Occurs within Individual Calcium Oxalate Crystal Idioblasts  

Microsoft Academic Search

the pattern OxA . AsA (erythorbic acid) . l-galactose . d-mannose. Our results demonstrate that P. stratiotes crystal idioblasts synthesize the OxA used for crystal formation, the OxA is derived from the number 1 and 2 carbons of AsA, and the proposed pathway of ascorbic acid synthesis via d-mannose and l-galactose is operational in individual P. stratiotes crystal idioblasts. These

Todd A. Kostman; Nathan M. Tarlyn; Frank A. Loewus; Vincent R. Franceschi

2001-01-01

377

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

378

Valproic Acid Prevents Penile Fibrosis and Erectile Dysfunction in Cavernous Nerve Injured Rats  

PubMed Central

Introduction Bilateral cavernous nerve injury (BCNI) causes profound penile changes such as apoptosis and fibrosis leading to erectile dysfunction (ED). Histone deacetylase (HDAC) has been implicated in chronic fibrotic diseases. Aims This study will characterize the molecular changes in penile HDAC after BCNI and determine if HDAC inhibition can prevent BCNI-induced ED and penile fibrosis. Methods Five groups of rats (8–10 wks, n=10/group) were utilized: 1) sham, 2&3) BCNI 14 and 30 days following injury, and 4&5) BCNI treated with HDAC inhibitor valproic acid (VPA 250mg/kg; 14 and 30 days). All groups underwent cavernous nerve stimulation (CNS) to determine intracavernosal pressure (ICP). Penile HDAC3, HDAC4, fibronectin, and transforming growth factor-?1 (TGF-?1) protein expression (Western blot) were assessed. Trichrome staining and the fractional area of fibrosis were determined in penes from each group. Cavernous smooth muscle content was assessed by immunofluorescence to alpha smooth muscle actin (?-SMA) antibodies. Main Outcome Measures ICP; HDAC3, HDAC4, fibronectin and TGF-?1 protein expression; penile fibrosis; penile ?-SMA content. Results There was a voltage-dependent decline (p<0.05) in ICP to CNS 14 and 30 days after BCNI. Penile HDAC3, HDAC4, and fibronectin were significantly increased (P<0.05) 14 days after BCNI. There was a slight increase in TGF-?1 protein expression after BCNI. Histological analysis showed increased (P<0.05) corporal fibrosis after BCNI at both time points. VPA treatment decreased (P<0.05) penile HDAC3, HDAC4, and fibronectin protein expression as well as corporal fibrosis. There was no change in penile ?-SMA between all groups. Furthermore, VPA-treated BCNI rats had improved erectile responses to CNS (P<0.05). Conclusion HDAC-induced pathological signaling in response to BCNI contributes to penile vascular dysfunction after BCNI. Pharmacological inhibition of HDAC prevents penile fibrosis, normalizes fibronectin expression, and preserves erectile function. The HDAC pathway may represent a suitable target in preventing the progression of ED occurring post-RP.

Hannan, Johanna L.; Kutlu, Omer; Stopak, Bernard L.; Liu, Xiaopu; Castiglione, Fabio; Hedlund, Petter; Burnett, Arthur L.; Bivalacqua, Trinity J.

2014-01-01

379

Amlodipine prevents apoptotic cell death by correction of elevated intracellular calcium in a primary neuronal model of Batten disease (CLN3 disease).  

PubMed

CLN3 disease (Spielmeyer-Vogt-Sjogren-Batten disease) is a severe pediatric neurodegenerative disorder for which there is currently no effective treatment. The disease is characterized by progressive neuronal death, which may be triggered by abnormal intracellular calcium levels leading to neuronal apoptosis. Previously, we demonstrated reversal of the calcium effect in a neuroblastoma cell line using amlodipine and other calcium channel antagonists. In the present studies, we developed a CLN3 siRNA-inhibited primary rat neuron model to further study etoposide-induced calcium changes and apoptosis in CLN3 disease followed by recovery experiments with amlodipine. Our results show that intracellular calcium is significantly elevated in siRNA-inhibited cortical neurons after potassium chloride-induced depolarization. We were also able to show that amlodipine, a predominantly L-type dihydropyrimidine calcium channel antagonist can reverse the aberrant calcium elevations in this model of the disease. We performed an in situ TUNEL assay following etoposide-exposure to siRNA inhibited primary neurons, and apoptotic nuclei were detected providing additional evidence that increased neuronal apoptosis is associated with increased calcium levels. Amlodipine also reduced the absolute number of apoptotic cells in this experimental model. PMID:23769828

Warnock, Ashley; Tan, Lu; Li, Changhong; An Haack, Kristina; Narayan, Srinivas B; Bennett, Michael J

2013-07-12

380

KMUP-1 Suppresses RANKL-Induced Osteoclastogenesis and Prevents Ovariectomy-Induced Bone Loss: Roles of MAPKs, Akt, NF-?B and Calcium/Calcineurin/NFATc1 Pathways  

PubMed Central

Background KMUP-1 is a xanthine derivative with inhibitory activities on the phosphodiesterase (PDE) 3,4 and 5 isoenzymes to suppress the degradation of cyclic AMP and cyclic GMP. However, the effects of KMUP-1 on osteoclast differentiation are still unclear. In this study, we investigated whether KMUP-1 inhibits osteoclastogenesis induced by RANKL in RAW 264.7 cells and bone loss induced by ovariectomy in mice, and the underlying mechanisms. Principal Findings In vitro, KMUP-1 inhibited RANKL-induced TRAP activity, the formation of multinucleated osteoclasts and resorption-pit formation. It also inhibited key mediators of osteoclastogenesis including IL-1?, IL-6, TNF-? and HMGB1. In addition, KMUP-1 inhibited RANKL-induced activation of signaling molecules (Akt, MAPKs, calcium and NF-?B), mRNA expression of osteoclastogensis-associated genes (TRAP, MMP-9, Fra-1, and cathepsin K) and transcription factors (c-Fos and NFATc1). Furthermore, most inhibitory effects of KMUP-1 on RANKL-mediated signal activations were reversed by a protein kinase A inhibitor (H89) and a protein kinase G inhibitor (KT5823). In vivo, KMUP-1 prevented loss of bone mineral content, preserved serum alkaline phosphate and reduced serum osteocalcin in ovariectomized mice. Conclusions KMUP-1 inhibits RANKL-induced osteoclastogenesis in vitro and protects against ovariectomy-induced bone loss in vivo. These effects are mediated, at least in part, by cAMP and cGMP pathways. Therefore, KMUP-1 may have a role in pharmacologic therapy of osteoporosis.

Lin, I-Ling; Ho, Mei-Ling; Hsu, Pei-Chuan; Chen, Li-Wen; Chen, Ing-Jun; Yeh, Jwu-Lai

2013-01-01

381

Effect of sodium gluconate on the solubility of calcium lactate.  

PubMed

Calcium and lactate are present in excess of their solubility in Cheddar cheese. Consequently, calcium lactate crystals (CLC) are a common defect in Cheddar cheese. A novel approach for preventing CLC is the addition of sodium gluconate. Sodium gluconate has the potential to increase the solubility of calcium and lactate by forming soluble complexes with calcium and lactate ions, and preventing them from being available for the formation of CLC. The objective of this study was to determine if sodium gluconate could increase the solubility of calcium lactate (CaL(2)). Seven CaL(2) solutions (5.31% wt/wt) with 7 levels of sodium gluconate (0, 0.5, 1, 1.5, 2, 3, and 4% wt/wt) were made in triplicate. Solutions were stored at 7 °C for 21 d, and were visually inspected for CLC formation. Subsequently, they were filtered to remove CLC and the supernatant was analyzed for lactic acid and gluconic acid by HPLC and for calcium by atomic absorption spectroscopy. The visual inspection demonstrated that CLC were formed in the solution with 0% gluconate after the first day of storage and CLC continued to accumulate over time. A minute amount of CLC was also visible in the solution with 0.5% gluconate after 21 d of storage, whereas CLC were not visible in the other solutions. The HPLC results indicated a higher concentration of calcium and lactic acid in the filtrate from the solutions containing added gluconate. Thus, sodium gluconate can increase the solubility of CaL(2). PMID:21943735

Phadungath, C; Metzger, L E

2011-10-01

382

A single residue in a novel ADP-ribosyl cyclase controls production of the calcium-mobilizing messengers cyclic ADP-ribose and nicotinic acid adenine dinucleotide phosphate.  

PubMed

Cyclic ADP-ribose and nicotinic acid adenine dinucleotide phosphate are ubiquitous calcium-mobilizing messengers produced by the same family of multifunctional enzymes, the ADP-ribosyl cyclases. Not all ADP-ribosyl cyclases have been identified, and how production of different messengers is achieved is incompletely understood. Here, we report the cloning and characterization of a novel ADP-ribosyl cyclase (SpARC4) from the sea urchin, a key model organism for the study of calcium-signaling pathways. Like several other members of the ADP-ribosyl cyclase superfamily, SpARC4 is a glycoprotein targeted to the plasma membrane via a glycosylphosphatidylinositol anchor. However, unlike most other members, SpARC4 shows a remarkable preference for producing cyclic ADP-ribose over nicotinic acid adenine dinucleotide phosphate. Mutation of a single residue (tyrosine 142) within a noncanonical active site reversed this striking preference. Our data highlight further diversification of this unusual enzyme family, provide mechanistic insight into multifunctionality, and suggest that different ADP-ribosyl cyclases are fine-tuned to produce specific calcium-mobilizing messengers. PMID:20385553

Ramakrishnan, Latha; Muller-Steffner, Hélène; Bosc, Christophe; Vacquier, Victor D; Schuber, Francis; Moutin, Marie-Jo; Dale, Leslie; Patel, Sandip

2010-06-25

383

A Single Residue in a Novel ADP-ribosyl Cyclase Controls Production of the Calcium-mobilizing Messengers Cyclic ADP-ribose and Nicotinic Acid Adenine Dinucleotide Phosphate*  

PubMed Central

Cyclic ADP-ribose and nicotinic acid adenine dinucleotide phosphate are ubiquitous calcium-mobilizing messengers produced by the same family of multifunctional enzymes, the ADP-ribosyl cyclases. Not all ADP-ribosyl cyclases have been identified, and how production of different messengers is achieved is incompletely understood. Here, we report the cloning and characterization of a novel ADP-ribosyl cyclase (SpARC4) from the sea urchin, a key model organism for the study of calcium-signaling pathways. Like several other members of the ADP-ribosyl cyclase superfamily, SpARC4 is a glycoprotein targeted to the plasma membrane via a glycosylphosphatidylinositol anchor. However, unlike most other members, SpARC4 shows a remarkable preference for producing cyclic ADP-ribose over nicotinic acid adenine dinucleotide phosphate. Mutation of a single residue (tyrosine 142) within a noncanonical active site reversed this striking preference. Our data highlight further diversification of this unusual enzyme family, provide mechanistic insight into multifunctionality, and suggest that different ADP-ribosyl cyclases are fine-tuned to produce specific calcium-mobilizing messengers.

Ramakrishnan, Latha; Muller-Steffner, Helene; Bosc, Christophe; Vacquier, Victor D.; Schuber, Francis; Moutin, Marie-Jo; Dale, Leslie; Patel, Sandip

2010-01-01

384

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

385

Preventive effects of p-coumaric acid on lysosomal dysfunction and myocardial infarct size in experimentally induced myocardial infarction.  

PubMed

The present study was designed to evaluate the preventive effects of p-coumaric acid on lysosomal dysfunction and myocardial infarct size in isoproterenol induced myocardial infarcted rats. Male albino Wistar rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days after which isoproterenol (100mg/kg body weight) was injected subcutaneously into rats twice at an interval of 24h (8th and 9th day).The activity/levels of serum cardiac diagnostic markers, heart lysosomal lipid peroxidation products and the activities of lysosomal enzymes (?-glucuronidase, ?-galactosidase, cathepsin-B and cathepsin-D) were significantly (P<0.05) increased in the serum and heart of isoproterenol induced myocardial infarcted rats. Isoproterenol also lowered the activities of ?-glucuronidase and cathepsin-D in the lysosomal fraction. The pretreatment with p-coumaric acid significantly (P<0.05) prevented the changes in the levels of lysosomal lipid peroxidation products and the activities of lysosomal enzymes. In addition, p-coumaric acid greatly reduced myocardial infarct size. p-Coumaric acid pretreatment (8 mg/kg body weight) to normal rats did not show any significant effect. Thus, this study showed that p-coumaric acid prevents lysosomal dysfunction against cardiac damage induced by isoproterenol and brings back the levels of lipid peroxidation products and activities of lysosomal enzymes to near normal levels. The in vitro study also revealed the free radical scavenging activity of p-coumaric acid. Thus, the observed effects are due to p-coumaric acid's free radical scavenging and membrane stabilizing properties. PMID:23178520

Jyoti Roy, Abhro; Stanely Mainzen Prince, P

2013-01-15

386

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

PubMed

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

Yi, Jine; Xia, Wei; Wu, Jianping; Yuan, Liyun; Wu, Jing; Tu, Di; Fang, Jun; Tan, Zhuliang

2014-01-01

387

[Omega-3-fatty acids, Mediterranean cooking, low-fat diet. What really prevents myocardial infarct?].  

PubMed

The strength of evidence in support of dietary measures in the secondary prevention of coronary artery disease is variable (Table 1). The most impressive data available concern the impact of omega-3 fatty acids found in sea-fish at an intake of about 1.0 g/day, but the data underscoring the value of a Mediterranean diet are also convincing. No comparable data are available for low-fat and fat-modified diets. For diabetics, an HbA1c of < 7% should be achieved. There is indirect evidence that a body mass index of between 18.5 and 23.9 kg is optimal, and can be achieved by physical exercise and weight control. Weight reduction also lowers blood pressure, a goal that can equally be reached by a low-salt diet rich in fruit and vegetables, and the practice of endurance sports. The results of ongoing studies on the use of vitamin supplements are as yet unavailable. PMID:11862790

von Schacky, C

2002-01-24

388

{alpha}-Lipoic acid prevents lipotoxic cardiomyopathy in acyl CoA-synthase transgenic mice  

SciTech Connect

{alpha}-Lipoic acid ({alpha}-LA) mimics the hypothalamic actions of leptin on food intake, energy expenditure, and activation of AMP-activated protein kinase (AMPK). To determine if, like leptin, {alpha}-LA protects against cardiac lipotoxicity, {alpha}-LA was fed to transgenic mice with cardiomyocyte-specific overexpression of the acyl CoA synthase (ACS) gene. Untreated ACS-transgenic mice died prematurely with increased triacylglycerol content and dilated cardiomyopathy, impaired systolic function and myofiber disorganization, apoptosis, and interstitial fibrosis on microscopy. In {alpha}-LA-treated ACS-transgenic mice heart size, echocardiogram and TG content were normal. Plasma TG fell 50%, hepatic-activated phospho-AMPK rose 6-fold, sterol regulatory element-binding protein-1c declined 50%, and peroxisome proliferator-activated receptor-{gamma} cofactor-1{alpha} mRNA rose 4-fold. Since food restriction did not prevent lipotoxicity, we conclude that {alpha}-LA treatment, like hyperleptinemia, protects the heart of ACS-transgenic mice from lipotoxicity.

Lee, Young [Gifford Laboratories, Touchstone Center for Diabetes Research, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States); Department of Internal Medicine, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States); Naseem, R. Haris [Division of Cardiology, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States); Department of Internal Medicine, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States); Park, Byung-Hyun [Gifford Laboratories, Touchstone Center for Diabetes Research, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States); Department of Internal Medicine, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States); Garry, Daniel J. [Department of Internal Medicine, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States); Richardson, James A. [Department of Pathology, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States); Schaffer, Jean E. [Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110 (United States); Unger, Roger H. [Gifford Laboratories, Touchstone Center for Diabetes Research, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States) and Department of Internal Medicine, University of Texas, Southwestern Medical Center, Dallas, TX 75390-8854 (United States) and Veterans Affairs Medical Center, Dallas, TX 75216 (United States)]. E-mail: roger.unger@utsouthwestern.edu

2006-05-26

389

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.

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

2014-01-01

390

Calcification prevention tablets  

NASA Technical Reports Server (NTRS)

Citric acid tablets, which slowly release citric acid when flushed with water, are under development by the Navy for calcification prevention. The citric acid dissolves calcium carbonate deposits and chelates the calcium. For use in urinals, a dispenser is not required because the tablets are non-toxic and safe to handle. The tablets are placed in the bottom of the urinal, and are consumed in several hundred flushes (the release rate can be tailored by adjusting the formulation). All of the ingredients are environmentally biodegradable. Mass production of the tablets on commercial tableting machines was demonstrated. The tablets are inexpensive (about 75 cents apiece). Incidences of clogged pipes and urinals were greatly decreased in long term shipboard tests. The corrosion rate of sewage collection pipe (90/10 Cu/Ni) in citric acid solution in the laboratory is several mils per year at conditions typically found in traps under the urinals. The only shipboard corrosion seen to date is of the yellow brass urinal tail pieces. While this is acceptable, the search for a nontoxic corrosion inhibitor is underway. The shelf life of the tablets is at least one year if stored at 50 percent relative humidity, and longer if stored in sealed plastic buckets.

Lindsay, Geoffrey A.; Hasting, Michael A.; Gustavson, Michael A.

1991-01-01

391

Oral chemoprevention with acetyl salicylic Acid, vitamin D and calcium reduces the risk of tobacco carcinogen-induced bladder tumors in mice.  

PubMed

Bladder cancer is a common urological malignancy with high recurrence rate, which may be reduced by chemoprevention. The aim was to evaluate chemoprevention in a mouse model of tobacco carcinogen-induced bladder tumors. A total of 60 A/J mice were randomized to normal diet, diet with low calcium, and diet with chemoprevention (acetyl salicylic acid, 1-alpha 25(OH)2-vitamin D3 and calcium). There were significantly fewer tumors (0 (0-0) vs. 0 (0-2), p = .045) and fewer animals with tumors (0/20 vs. 5/20, p = .045) in the chemoprevention group compared with controls. Thus, chemoprevention diet effectively reduced the tumor promoting effect of tobacco carcinogens in the mouse bladder. PMID:23915073

Pommergaard, H C; Burcharth, J; Rosenberg, J; Raskov, H

2013-08-01

392

A maize calcium-dependent protein kinase gene, ZmCPK4, positively regulated abscisic acid signaling and enhanced drought stress tolerance in transgenic Arabidopsis.  

PubMed

Calcium-dependent protein kinases (CDPKs) play essential roles in calcium-mediated signal transductions in plant response to abiotic stress. Several members have been identified to be regulators for plants response to abscisic acid (ABA) signaling. Here, we isolated a subgroup I CDPK gene, ZmCPK4, from maize. Quantitative real time PCR (qRT-PCR) analysis revealed that the ZmCPK4 transcripts were induced by various stresses and signal molecules. Transient and stable expression of the ZmCPK4-GFP fusion proteins revealed ZmCPK4 localized to the membrane. Moreover, overexpression of ZmCPK4 in the transgenic Arabidopsis enhanced ABA sensitivity in seed germination, seedling growth and stomatal movement. The transgenic plants also enhanced drought stress tolerance. Taken together, the results suggest that ZmCPK4 might be involved in ABA-mediated regulation of stomatal closure in response to drought stress. PMID:23911729

Jiang, Shanshan; Zhang, Dan; Wang, Li; Pan, Jiaowen; Liu, Yang; Kong, Xiangpei; Zhou, Yan; Li, Dequan

2013-10-01

393

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

394

Sinomenine protects against ischaemic brain injury: involvement of co-inhibition of acid-sensing ion channel 1a and L-type calcium channels  

PubMed Central

BACKGROUND AND PURPOSE Sinomenine (SN), a bioactive alkaloid, has been utilized clinically to treat rheumatoid arthritis in China. Our preliminary experiments indicated that it could protect PC12 cells from oxygen-glucose deprivation-reperfusion (OGD-R), we thus investigated the possible effects of SN on cerebral ischaemia and the related mechanism. EXPERIMENTAL APPROACH Middle cerebral artery occlusion in rats was used as an animal model of ischaemic stroke in vivo. The mechanisms of the effects of SN were investigated in vitro using whole-cell patch-clamp recording, calcium imaging in PC12 cells and rat cortical neurons subjected to OGD-R. KEY RESULTS Pretreatment with SN (10 and 30 mg·kg?1, i.p.) significantly decreased brain infarction and the overactivation of calcium-mediated events in rats subjected to 2 h ischaemia followed by 24 h reperfusion. Extracellular application of SN inhibited the currents mediated by acid-sensing ion channel 1a and L-type voltage-gated calcium channels, in the rat cultured neurons, in a concentration-dependent manner. These inhibitory effects contribute to the neuroprotection of SN against OGD-R and extracellular acidosis-induced cytotoxicity. More importantly, administration of SN (30 mg·kg?1, i.p.) at 1 and 2 h after cerebral ischaemia also decreased brain infarction and improved functional recovery. CONCLUSION AND IMPLICATIONS SN exerts potent protective effects against ischaemic brain injury when administered before ischaemia or even after the injury. The inhibitory effects of SN on acid-sensing ion channel 1a and L-type calcium channels are involved in this neuroprotection.

Wu, Wen-Ning; Wu, Peng-Fei; Chen, Xiang-Long; Zhang, Zui; Gu, Jun; Yang, Yuan-Jian; Xiong, Qiu-Ju; Ni, Lan; Wang, Fang; Chen, Jian-Guo

2011-01-01

395

The N-terminal 20-Amino Acid Region of Guanine Nucleotide Exchange Factor Vav1 Plays a Distinguished Role in T Cell Receptor-mediated Calcium Signaling*  

PubMed Central

Vav1 is a guanine nucleotide exchange factor (GEF) specifically expressed in hematopoietic cells. It consists of multiple structural domains and plays important roles in T cell activation. The other highly conserved isoforms of Vav family, Vav2 and Vav3, are ubiquitously expressed in human tissues including lymphocytes. All three Vav proteins activate Rho family small GTPases, which are involved in a variety of biological processes during T cell activation. Intensive studies have demonstrated that Vav1 is indispensable for T cell receptor (TCR)-mediated signal transduction, whereas Vav2 and Vav3 function as GEFs that overlap with Vav1 on TCR-induced cytoskeleton reorganization. T cells lacking Vav1 exhibited severe defect in TCR-mediated calcium elevation, indicating that the co-existing Vav2 and Vav3 did not compensate Vav1 in calcium signaling. What is the functional particularity of Vav1 in lymphocytes? In this study, we identified the N-terminal 20 amino acids of Vav1 in the calponin homology (CH) domain to be essential for its interaction with calmodulin (CaM) that leads to TCR-induced calcium mobilization. Substitution of the 1–20 amino acids of Vav1 with those of Vav2 or Vav3 abolished the association with CaM, and the N-terminal mutations of Vav1 failed to potentiate normal TCR-induced calcium mobilization, that in turn, suspended nuclear factor of activated T cells (NFAT) activation and IL-2 production. This study highlights the importance of the N-terminal 20 aa of Vav1 for CaM binding, and provides new insights into the distinguished and irreplaceable role of Vav1 in T cell activation and signal transduction.

Li, Shi-Yang; Du, Ming-Juan; Wan, Ya-Juan; Lan, Bei; Liu, Yao-Hui; Yang, Yin; Zhang, Cui-Zhu; Cao, YouJia

2013-01-01

396

Cilnidipine, an L/N-type calcium channel blocker prevents acquisition and expression of ethanol-induced locomotor sensitization in mice.  

PubMed

Several evidences indicated the involvement of L- and N-type calcium channels in behavioral effects of drugs of abuse, including ethanol. Calcium channels are implicated in ethanol-induced behaviors and neurochemical responses. Calcium channel antagonists block the psychostimulants induced behavioral sensitization. Recently, it is demonstrated that L-, N- and T-type calcium channel blockers attenuate the acute locomotor stimulant effects of ethanol. However, no evidence indicated the role of calcium channels in ethanol-induced psychomotor sensitization. Therefore, present study evaluated the influence of cilnidipine, an L/N-type calcium channel blocker on acquisition and expression of ethanol-induced locomotor sensitization. The results revealed that cilnidipine (0.1 and 1.0?g/mouse, i.c.v.) attenuates the expression of sensitization to locomotor stimulant effect of ethanol (2.0g/kg, i.p.), whereas pre- treatment of cilnidipine (0.1 and 1.0?g/mouse, i.c.v.) during development of sensitization blocks acquisition and attenuates expression of sensitization to locomotor stimulant effect of ethanol. Cilnidipine per se did not influence locomotor activity in tested doses. Further, cilnidipine had no influence on effect of ethanol on rotarod performance. These results support the hypothesis that neuroadaptive changes in calcium channels participate in the acquisition and the expression of ethanol-induced locomotor sensitization. PMID:22402189

Bhutada, Pravinkumar; Mundhada, Yogita; Patil, Jayshree; Rahigude, Anand; Zambare, Krushna; Deshmukh, Prashant; Tanwar, Dhanshree; Jain, Kishor

2012-04-11

397

Basic Fibroblast Growth Factor Maintains Calcium Homeostasis and Granulosa Cell Viability by Stimulating Calcium Efflux via a PKC Dependent Pathway  

Microsoft Academic Search

Previous studies have demonstrated that basic fibroblast growth factor prevents granulosa cell apoptosis. The following six observations provide insight into the mechanism by which basic fibroblast growth factor mediates its antiapoptotic action. First, loading granulosa cells with 1,2 bis(2-aminophenoxy)- ethane-N,N,N,N-tetraacetic acid, an intracellular calcium che- lator, prevented apoptosis when granulosa cells were deprived of basic fibroblast growth factor. Second, treatment

J. J. Peluso; A. PAPPALARDO; G. FERNANDEZ

2001-01-01