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1

Calcium phosphate, bile acids and colorectal cancer.  

PubMed

The biochemical and nutritional studies discussed here are consistent with the model presented in Figure 1. As shown in vitro, bile acids are precipitated by insoluble calcium phosphate. This calcium phosphate dependent precipitation drastically inhibits their cytotoxicity. A diet-induced increase in luminal surfactant concentration stimulates lytic activity of faecal water and intestinal cell damage resulting in an increased proliferation. The increase in luminal surfactant concentration and lytic activity of faecal water can be counteracted by supplemental dietary calcium phosphate. Supplemental calcium in humans increases the formation of insoluble calcium-phosphate-bile acid complexes in faeces, decreases the soluble fatty acid concentration and decreases lytic activity of faecal water. This sequence of effects offers a molecular explanation of the protective effects of supplemental calcium on proliferation as frequently observed (see studies cited above). It should be realised that this chain of evidence still lacks final proof of a preventive effect of dietary calcium on colorectal cancer. Until now, only protective effects on the first stage of development of colorectal cancer (hyperproliferation) have been observed. More well-designed studies in patients and healthy volunteers are needed using a combined biochemical, nutritional and clinical approach to elucidate the complex mechanism of the protective effect of calcium on colon cancer. PMID:1842734

Van der Meer, R; Kleibeuker, J H; Lapré, J A

1991-10-01

2

Calcium and the prevention of colon cancer.  

PubMed

Diet is a major determinant of colon cancer risk. Calcium may protect against colon cancer, presumably by binding cytotoxic bile acids and fatty acids. Numerous studies support this proposition. In subjects at risk for colon cancer oral calcium supplementation has been shown to reduce rectal epithelial proliferation rate, thereby supposedly decreasing cancer risk. In contrast to the original hypothesis that phosphate counteracts the effect of calcium, evidence has now been provided that phosphate is crucial for the intraluminal binding of bile acids in complexes of calcium, phosphate, and bile acids. Supplemental calcium has been shown to reduce the cytotoxic potential of fecal water, which is probably attributable to the profound effect of calcium on bile acid and fatty acid metabolism. However, some reservation with regard to the protective ability of calcium seems to be warranted as we found that oral calcium supplementation caused an increase in epithelial proliferation rate in the sigmoid of patients with adenomatous polyps. Further controlled studies evaluating the effects of calcium on the epithelium of different parts of the colon should now be performed. PMID:1775941

Welberg, J W; Kleibeuker, J H; Van der Meer, R; Mulder, N H; De Vries, E G

1991-01-01

3

Calcium and the prevention of colon cancer.  

PubMed

Chemoprevention studies utilizing calcium have now progressed from basic measurements to clinical trials. Calcium's effects on epithelial cells have demonstrated decreased proliferation and induced cell differentiation with increasing levels of calcium in vitro, similar in vivo effects in rodent and human colon, and decreased carcinogen-induced colonic tumor formation in rodents. Current studies are attempting to inhibit colonic adenoma formation in human subjects. Most but not all epidemiologic studies also link increased dietary calcium with a decreased risk of colon cancer. In animal models, supplemental dietary calcium has decreased mammary epithelial cell hyperplasia and hyperproliferation and colonic cell hyperproliferation when the latter was induced by bile acids, fatty acids, and partial resection of the small intestine. Supplemental dietary calcium also decreased carcinogen-induced colonic tumors in several rodent models. In normal mice, and in mice carrying a targeted apc gene mutation, we recently increased colonic polypoid hyperplasias by a Western-style diet containing low calcium and vitamin D. In human subjects at increased risk for colon cancer, oral calcium supplementation significantly reduced colonic epithelial cell proliferation in most of the studies, including four randomized clinical trials. These studies have now progressed to short-term human clinical trials, including trials that measure the regrowth of transformed adenoma cells. Short-term adenoma-regrowth clinical trials, however, are limited in their ability to measure whether chemopreventive agents inhibit early genotoxic events, abnormal cellular metabolic activities involved in tumor promotion over many years, or the progression of adenoma cells to carcinoma. PMID:8538212

Lipkin, M; Newmark, H

1995-01-01

4

Vitamin D and Calcium Supplementation to Prevent Fractures  

MedlinePLUS

... Task Force FINAL | 1 Understanding Task Force Recommendations Vitamin D and Calcium Supplementation to Prevent Fractures The ... for you. What are vitamin D and calcium? Vitamin D and calcium are important nutrients that work ...

5

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

6

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

7

Effects of supplemental dietary calcium on the intestinal association of calcium, phosphate, and bile acids.  

PubMed

It has been suggested that supplemental dietary calcium decreases hyperproliferation of colonic epithelial cells because calcium precipitates and thus inactivates luminal bile acids. Therefore, 12 healthy men were studied before and after dietary calcium supplementation (35.5 mmol/day) to quantify intestinal associations of calcium, phosphate, and bile acids. The supplemental dietary calcium was almost completely (95%) recovered, mainly in feces. Calcium increased the fecal excretion of both phosphate (31%) and bile acids (53%) and decreased the ratio of dihydroxy to trihydroxy bile acids in duodenal bile almost twofold. In vitro studies showed that precipitation of glycodeoxycholic acid was caused by the formation of insoluble calcium phosphate. Water-soluble and calcium-associated amounts of phosphate and bile acids in feces were measured by resolubilization studies, using the calcium chelator ethylenediaminetetraacetate. In both the control and calcium periods, significant amounts of phosphate (80% and 90%) and bile acids (33% and 50%) were calcium-associated. Moreover, the calcium-induced increments in fecal phosphate and bile acids were completely calcium-associated. Calcium decreased the amount of water-soluble phosphate but not of bile acids. These results indicate that supplemental calcium stimulates formation of insoluble calcium phosphate in the intestinal lumen and thus increases binding of luminal bile acids. PMID:2121581

Van der Meer, R; Welberg, J W; Kuipers, F; Kleibeuker, J H; Mulder, N H; Termont, D S; Vonk, R J; De Vries, H T; De Vries, E G

1990-12-01

8

Calcium channel antagonists prevent adaptive responses to ethanol.  

PubMed

Prolonged ethanol administration causes upregulation of dihydropyridine-sensitive binding sites, thought to represent neuronal calcium channels, and these channels appear to play an important role in ethanol physical dependence. Dihydropyridine calcium channel antagonists, when given chronically with ethanol, prevent the development of tolerance to ethanol and the ethanol withdrawal syndrome. The upregulation of binding sites for these compounds was also prevented. Epileptiform activity has been described in isolated hippocampal slices after chronic ethanol treatment in vivo. This was prevented, stereoselectively, by the dihydropyridine calcium channel antagonist, isradipine, that did not affect the hyperexcitability produced in control slices by the GABAA antagonist, bicuculline. PMID:7748308

Little, H J; Dolin, S J; Whittington, M A

1993-01-01

9

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

10

Calcium Prevents Tumorigenesis in a Mouse Model of Colorectal Cancer  

Microsoft Academic Search

Background and AimCalcium 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.MethodsFor gene expression analysis, 6 non-tumor colorectal tissues of mice

Ji-Lin Wang; Yan-Wei Lin; Hui-Min Chen; Xuan Kong; Hua Xiong; Nan Shen; Jie Hong; Jing-Yuan Fang

2011-01-01

11

Germination of Bacterial Endospores with Calcium and Dipicolinic Acid  

Microsoft Academic Search

Aerobic and anaerobic bacterial endospores can be germinated if calcium chloride and dipicolinic acid are added to well-washed suspensions. Maximum germination is obtained when the calcium and acid are present in a molar ratio of one or more. This suggests that the 1:1 chelate of calcium and dipicolinic acid is the agent that induces germination.

Hans Riemann; Z. John Ordal

1961-01-01

12

Osteoporosis prevention education: behavior theories and calcium intake.  

PubMed

Osteoporosis is a worldwide health concern. Preventing osteoporosis, and subsequent fractures, has become a goal of many health care practitioners, especially dietetics professionals. However, few prevention models have proven effective. The goal of this project was to determine whether an educational, theory-based osteoporosis prevention program would significantly impact calcium intake. This project used a convenience sample of 42 women who participated in an 8-week educational intervention, similarly to a community class. The program included hands-on activities to increase self-efficacy and was based on the Health Belief Model and Theory of Reasoned Action (TRA). The main outcome measures were calcium intake and constructs from the Health Belief Model and TRA. Significant changes in the Health Belief Model and TRA constructs at postintervention included increased perceived susceptibility to osteoporosis ( P <.001), perceived benefits to increasing calcium intake ( P <.001), and increased self-efficacy related to calcium intake ( P calcium. Postintervention calcium intake significantly increased to 821+/-372 mg/day ( P <.0001). Results of this project can be used as guidelines for dietetics professionals to develop osteoporosis prevention programs for their clientele. PMID:15635352

Tussing, Lisa; Chapman-Novakofski, Karen

2005-01-01

13

Genetic ablation of calcium-independent phospholipase A2gamma prevents obesity and insulin resistance during high fat feeding by mitochondrial uncoupling and increased adipocyte fatty acid oxidation.  

PubMed

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

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

2010-11-19

14

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

15

Original article Acid gelation of colloidal calcium phosphate-  

E-print Network

Original article Acid gelation of colloidal calcium phosphate- depleted preheated milk Marie Research, RD 128, 91767 Palaiseau Cedex, France Received 25 September 2008 ­ Accepted 23 March 2009 of milk. Milks were depleted in Calcium (Ca) by dialysis against milk permeate containing a cation

Paris-Sud XI, Université de

16

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. PMID:22442301

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

2012-01-01

17

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

18

Effect of blending calcium compounds on hydrolytic degradation of poly( dl-lactic acid-co-glycolic acid)  

Microsoft Academic Search

To clarify the effect of blending calcium compounds with different acidity or basicity on the degradation of poly(dl-lactic acid-co-glycolic acid) (PLGA), composite materials composed of PLGA incorporated with 30mass% of calcium dihydrogenphosphate (CDHP), calcium hydrogenphosphate, calcium phosphate, and calcium carbonate (CC) were prepared by mixing in dioxane followed by freeze-drying. The porous composite materials were then compressed to yield nonporous

M. Ara; M. Watanabe; Y. Imai

2002-01-01

19

Calcium and Cancer Prevention: Strengths and Limits of the Evidence  

MedlinePLUS

... is high in calcium) and some types of antacids, especially antacids containing calcium carbonate or sodium bicarbonate (baking soda), ... LP. Life-threatening milk-alkali syndrome resulting from antacid ingestion during pregnancy. Medical Journal of Australia 2005; ...

20

Calcium alginate beads as core carriers of 5-aminosalicylic acid.  

PubMed

The utilization of calcium alginate beads as core carriers for delayed dissolution followed by burst release as a potential method of intestinal site specific drug delivery was investigated. 5-Aminosalicylic acid was spray-coated on dried calcium alginate beads and then coated with different percentages of enteric coating polymer and/or sustained-release polymer. Beads coated with more than 6% (w/w) methacrylic copolymer plastisized with dibutyl sebacate and triethyl citrate resisted release in 2-hr acid fluid challenge and allowed immediate dissolution upon transfer to simulated intestinal fluid. With 6% (w/w) methacrylic copolymer on top of 4% (w/w) ethylcellulose polymer, the major portion of drug did not release in 2 hr of acid treatment or the next 3 hr of simulated intestinal fluid treatment. This dosage form provides the possibility to deliver drug to the lower intestinal tract with minimal early release, followed by sustained release in the colon. PMID:1409392

Lin, S Y; Ayres, J W

1992-09-01

21

Inhibiting MAP Kinase Activity Prevents Calcium Transients and Mitosis Entry in Early Sea Urchin Embryos*  

E-print Network

Inhibiting MAP Kinase Activity Prevents Calcium Transients and Mitosis Entry in Early Sea Urchin Kingdom A transient calcium increase triggers nuclear enve- lope breakdown (mitosis entry) in sea urchin embryos. Cdk1/cyclin B kinase activation is also known to be re- quired for mitosis entry. More recently

Newcastle upon Tyne, University of

22

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

23

Vitamin D and Calcium Supplementation to Prevent Fractures  

MedlinePLUS

... decisions about what screening tests, counseling services, and preventive medicines to get and when to get them. Many ... you learn about screening tests, counseling services, and preventive medicines. These services can keep you healthy and prevent ...

24

Characterization of the adsorption of conjugated and unconjugated bile acids to insoluble, amorphous calcium phosphate.  

PubMed

Recently we showed that supplemental dietary calcium stimulates the intestinal formation of insoluble calcium phosphate and decreases the ratio of dihydroxy to trihydroxy bile acids in human duodenal bile. Because previous in vitro studies indicated that these effects could be due to differential adsorption of bile acids to amorphous calcium phosphate, we characterized the binding of bile acids to calcium phosphate. Freshly formed, amorphous, calcium phosphate bound and thus precipitated glycine-conjugated and unconjugated bile acids, whereas taurine-conjugated bile acids showed little binding. Glycochenodeoxycholic acid hardly adsorbed to other insoluble calcium phosphates, including hydroxyapatite. Adsorption studies using increasing amounts of glycine-conjugated and unconjugated bile acids showed that binding occurred above a bile acid-specific critical minimum concentration, dependent on bile acid hydrophobicity. The simultaneous use of a fluorescent hydrophobic probe indicated that this binding was due to ionic adsorption of monomers of bile acids, followed by their hydrophobic aggregation on the calcium phosphate surface, probably in the form of a bilayer. Finally, using human duodenal bile we found that amorphous calcium phosphate, but not Ca2+, preferentially bound and thus precipitated dihydroxy bile acids. We conclude that freshly formed, amorphous, calcium phosphate is a prerequisite for adsorption of bile acids and that monomers of glycine-conjugated and unconjugated dihydroxy bile acids have a high binding affinity for amorphous calcium phosphate. PMID:8071598

Govers, M J; Termont, D S; Van Aken, G A; Van der Meer, R

1994-05-01

25

Aluminum Citrate Prevents Renal Injury from Calcium Oxalate Crystal Deposition  

PubMed Central

Calcium oxalate monohydrate crystals are responsible for the kidney injury associated with exposure to ethylene glycol or severe hyperoxaluria. Current treatment strategies target the formation of calcium oxalate but not its interaction with kidney tissue. Because aluminum citrate blocks calcium oxalate binding and toxicity in human kidney cells, it may provide a different therapeutic approach to calcium oxalate-induced injury. Here, we tested the effects of aluminum citrate and sodium citrate in a Wistar rat model of acute high-dose ethylene glycol exposure. Aluminum citrate, but not sodium citrate, attenuated increases in urea nitrogen, creatinine, and the ratio of kidney to body weight in ethylene glycol–treated rats. Compared with ethylene glycol alone, the addition of aluminum citrate significantly increased the urinary excretion of both crystalline calcium and crystalline oxalate and decreased the deposition of crystals in renal tissue. In vitro, aluminum citrate interacted directly with oxalate crystals to inhibit their uptake by proximal tubule cells. These results suggest that treating with aluminum citrate attenuates renal injury in rats with severe ethylene glycol toxicity, apparently by inhibiting calcium oxalate’s interaction with, and retention by, the kidney epithelium. PMID:23138489

Besenhofer, Lauren M.; Cain, Marie C.; Dunning, Cody

2012-01-01

26

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

PubMed

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

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

1993-09-01

27

Calcium  

MedlinePLUS

... when taken with food. Some over-the-counter antacid products, such as Tums® and Rolaids®, contain calcium ... calcium excretion and thereby lower blood calcium levels. Antacids containing aluminum or magnesium increase calcium loss in ...

28

Calcium  

MedlinePLUS

... lead levels. Calcium carbonate is used as an antacid for “heartburn.” Calcium carbonate and calcium acetate are ... when given intravenously (by IV). Use as an antacid as calcium carbonate. Reducing phosphate levels in people ...

29

Fabrication of calcium phosphate-calcium sulfate injectable bone substitute using chitosan and citric acid.  

PubMed

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan solution as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA) and calcium sulfate hemihydrate (CSH) powders as the solid phase was prepared. Four groups containing different percentages (0-30%) of calcium sulfate hemihydrate (CSH, CaSO(4) . 0.5H(2)O) were investigated. Initial setting times for IBS with CSH were longer than those without CSH. The setting times for all compositions were in the range of 25-45 min. The injectability was improved by the addition of CSH in the present system. Scanning electron microscopy images showed that fiber-like crystallization appeared in the cements. The enhancement of crystallinity was confirmed by XRD profiles where the peak intensity of HAp increased with incubation time and the addition of CSH. Also, the compressive strength increased with the addition of CSH. The maximum compressive strength obtained for IBS was with 20% CSH after 28-day incubation in 100% humidity at 37 degrees C. PMID:19052849

Song, Ho-Yeon; Esfakur Rahman, A H M; Lee, Byong-Taek

2009-04-01

30

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

31

Interactions between red light, abscisic acid, and calcium in gravitropism  

NASA Technical Reports Server (NTRS)

The effect of red light on orthogravitropism of Merit corn (Zea mays L.) roots has been attributed to its effects on the transduction phase of gravitropism (AC Leopold, SH Wettlaufer [1988] Plant Physiol 87:803-805). In an effort to characterize the orthogravitropic transduction system, comparative experiments have been carried out on the effects of red light, calcium, and abscisic acid (ABA). The red light effect can be completely satisfied with added ABA (100 micromolar) or with osmotic shock, which is presumed to increase endogenous ABA. The decay of the red light effect is closely paralleled by the decay of the ABA effect. ABA and exogenous calcium show strong additive effects when applied to either Merit or a line of corn which does not require red light for orthogravitropism. Measurements of the ABA content show marked increases in endogenous ABA in the growing region of the roots after red light. The interpretation is offered that red light or ABA may serve to increase the cytoplasmic concentrations of calcium, and that this may be an integral part of orthogravitropic transduction.

Leopold, A. C.; LaFavre, A. K.

1989-01-01

32

Causal analysis of exercise and calcium intake behaviors for osteoporosis prevention among young women in Thailand.  

PubMed

The goal of health education is to provide information to affect attitudes, beliefs, and intentions for behavior change. However, little is known about the effects of changes in knowledge on behaviors for osteoporosis prevention. Our objective is to develop and test theoretical models of the effects of knowledge, attitude, and self-efficacy on exercise and calcium intake among young women before and after an intervention program. First, we hypothesized that knowledge would positively predict attitude, self-efficacy, calcium intake, and exercise. Second, attitude would positively predict self-efficacy, calcium intake, and exercise. Third, self-efficacy would positively predict calcium intake and exercise. Fourth, attitude and self-efficacy would mediate the effect of knowledge on calcium intake and exercise. At the beginning and end of the study, participants in the control group and intervention group completed the osteoporosis knowledge test, the osteoporosis health belief scale, the osteoporosis self-efficacy scale, a self-report for food records, and exercise. The causal model was examined as a result of our study. After the intervention program, calcium intake and exercise were predicted by knowledge when mediated by attitudes and self-efficacy. The final model accounted for 30% and 45% of the variance in calcium intake and exercise, respectively. We conclude that interventions to enhance young women's knowledge and self-efficacy may result in increased calcium intake and exercise. PMID:12148914

Piaseu, Noppawan; Schepp, Karen; Belza, Basia

2002-06-01

33

Surface modification of calcium-copper hydroxyapatites using polyaspartic acid  

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

34

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

E-print Network

It has been a practice to use seawater for preparing acid in offshore operations where fresh water is relatively expensive or logistically impossible to use. However, hydrochloric acid will release calcium ion into solution, which will combine...

He, Jia

2012-02-14

35

Osteoporosis Prevention Among Young Women: Psychosocial Models of Calcium Consumption and Weight-Bearing Exercise  

Microsoft Academic Search

Objective: To examine the putative determinants of two osteoporosis-preventive behaviors, calcium consumption and weight-bearing exercise, in 2 samples of young women (Sample 1, n = 202; Sample 2, n = 209). A common psychosocial model of both behaviors, comprising the health belief model and augmented with constructs drawn from social cognitive theory and the theory of planned behavior, was developed,

Sarah J. Schmiege; Leona S. Aiken; Jennifer L. Sander; Mary A. Gerend

2007-01-01

36

Highly enantioselective electrophilic ?-bromination of enecarbamates: chiral phosphoric acid and calcium phosphate salt catalysts.  

PubMed

Metal-free chiral phosphoric acids and chiral calcium phosphates both catalyze highly enantio- and diastereoselective electrophilic ?-bromination of enecarbamates to provide an atom-economical synthesis of enantioenriched vicinal haloamines. Either enantiomer can be formed in good yield with excellent diastereo- and enantioselectivity simply by switching the catalyst from a phosphoric acid to its calcium salt. PMID:22686436

Alix, Aurélien; Lalli, Claudia; Retailleau, Pascal; Masson, Géraldine

2012-06-27

37

DOCOSAHEXAENOIC ACID AND ARACHIDONIC ACID PREVENT ESSENTIAL FATTY ACID DEFICIENCY AND HEPATIC STEATOSIS  

PubMed Central

Objectives Essential fatty acids are important for growth, development, and physiologic function. Alpha-linolenic acid and linoleic acid are the precursors of docosahexaenoic and arachidonic acid, respectively, and have traditionally been considered the essential fatty acids. However, we hypothesized that docosahexaenoic acid and arachidonic acid can function as the essential fatty acids. Methods Using a murine model of essential fatty acid deficiency and consequent hepatic steatosis, we provided mice with varying amounts of docosahexaenoic and arachidonic acids to determine whether exclusive supplementation of docosahexaenoic and arachidonic acids could prevent essential fatty acid deficiency and inhibit or attenuate hepatic steatosis. Results Mice supplemented with docosahexaenoic and arachidonic acids at 2.1% or 4.2% of their calories for 19 days had normal liver histology and no biochemical evidence of essential fatty acid deficiency, which persisted when observed after 9 weeks. Conclusion Supplementation of sufficient amounts of docosahexaenoic and arachidonic acids alone without alpha-linolenic and linoleic acids meets essential fatty acid requirements and prevents hepatic steatosis in a murine model. PMID:22038210

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

2012-01-01

38

Relationship between biliary calcium and bile acid secretion in the regenerating liver of the rat.  

PubMed Central

Biliary calcium secretion during liver regeneration following two-thirds hepatectomy was studied in Wistar rats. Calcium output per 100 g body weight was significantly reduced at 24 h post-hepatectomy but not at other times. Values per gram of liver were significantly increased at 48 h and 96 h. A significant relationship was found between bile acid output and calcium output into bile both in controls and hepatectomized animals. The number of nmol of calcium secreted per nmol of bile acids was increased at 24 h post-hepatectomy parallel to an increased choleretic capacity of bile acids and a decrease in the fraction of bile acid independent flow. Our data confirm that bile acid secretion is an important determinant in the secretion of calcium into bile after partial hepatectomy in the rat. PMID:3426947

Pérez-Barriocanal, F.; Esteller, A.; González Gallego, J.

1987-01-01

39

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

PubMed

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

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

2013-04-01

40

CO.sub.2 Pretreatment prevents calcium carbonate formation  

DOEpatents

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

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

1980-01-01

41

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

42

Protection against Heat Stress-Induced Oxidative Damage in Arabidopsis Involves Calcium, Abscisic Acid, Ethylene, and Salicylic Acid  

Microsoft Academic Search

Plants, in common with all organisms, have evolved mechanisms to cope with the problems caused by high temperatures. We examined specifically the involvement of calcium, abscisic acid (ABA), ethylene, and salicylic acid (SA) in the protection against heat-induced oxidative damage in Arabidopsis. Heat caused increased thiobarbituric acid reactive substance levels (an indicator of oxidative damage to membranes) and reduced survival.

Jane Larkindale; Marc R. Knight

2002-01-01

43

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

PubMed

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

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

2014-03-15

44

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

45

Protection against Heat Stress-Induced Oxidative Damage in Arabidopsis Involves Calcium, Abscisic Acid, Ethylene, and Salicylic Acid  

PubMed Central

Plants, in common with all organisms, have evolved mechanisms to cope with the problems caused by high temperatures. We examined specifically the involvement of calcium, abscisic acid (ABA), ethylene, and salicylic acid (SA) in the protection against heat-induced oxidative damage in Arabidopsis. Heat caused increased thiobarbituric acid reactive substance levels (an indicator of oxidative damage to membranes) and reduced survival. Both effects required light and were reduced in plants that had acquired thermotolerance through a mild heat pretreatment. Calcium channel blockers and calmodulin inhibitors increased these effects of heating and added calcium reversed them, implying that protection against heat-induced oxidative damage in Arabidopsis requires calcium and calmodulin. Similar to calcium, SA, 1-aminocyclopropane-1-carboxylic acid (a precursor to ethylene), and ABA added to plants protected them from heat-induced oxidative damage. In addition, the ethylene-insensitive mutant etr-1, the ABA-insensitive mutant abi-1, and a transgenic line expressing nahG (consequently inhibited in SA production) showed increased susceptibility to heat. These data suggest that protection against heat-induced oxidative damage in Arabidopsis also involves ethylene, ABA, and SA. Real time measurements of cytosolic calcium levels during heating in Arabidopsis detected no increases in response to heat per se, but showed transient elevations in response to recovery from heating. The magnitude of these calcium peaks was greater in thermotolerant plants, implying that these calcium signals might play a role in mediating the effects of acquired thermotolerance. Calcium channel blockers and calmodulin inhibitors added solely during the recovery phase suggest that this role for calcium is in protecting against oxidative damage specifically during/after recovery. PMID:11842171

Larkindale, Jane; Knight, Marc R.

2002-01-01

46

The role of calcium in the prevention of cardiovascular disease--a review of observational studies and randomized clinical trials.  

PubMed

Calcium is a mineral that is important for bone health and has also been suggested to play a role in the prevention of cardiovascular disease (CVD). Lately, the potential effects of both inadequate and excessive calcium intake have received growing attention. In this review, we summarize the evidence from experimental, epidemiologic, and clinical studies investigating the role of calcium intake, either from the diet or from supplements, as well as blood concentrations, in relation to the risk of CVD in adults. In vitro and in vivo laboratory studies suggest that calcium may be involved in CVD development through multiple pathways, including blood cholesterol, insulin secretion and sensitivity, vasodilation, inflammatory profile, thrombosis, obesity, and vascular calcification. Several prospective epidemiologic studies have examined how dietary or supplemental calcium intake is associated with CVD incidence or mortality in middle-aged and older adults, and the results are inconsistent. Prospective studies investigating blood concentrations of calcium have also reported mixed results. However, changes in blood calcium concentrations may reflect a disturbed calcium phosphate balance, which is associated with increased risk of CVD. To date there is no randomized clinical trial that has been designed specifically to test the effect of calcium supplementation on the risk of CVD as the primary end point. Existing trials have performed secondary analyses, and most of them have been conducted among postmenopausal women. These trials suggest that calcium supplementation has no effect on CVD development; however, they do not allow a definitive conclusion to be drawn. The average daily intake of calcium is low in many populations; however, the evidence for a potential role of dietary or supplemental calcium in the prevention of CVD remains insufficient and inconclusive. Only large-scale randomized trials designed to investigate the effects of calcium supplementation on CVD events as the primary end point, as well as short-term trials investigating the effect on coronary biomarkers, can provide a definitive answer. PMID:24022513

Rautiainen, Susanne; Wang, Lu; Manson, JoAnn E; Sesso, Howard D

2013-11-01

47

Buffering effects of calcium salts in kimchi: lowering acidity, elevating lactic acid bacterial population and dextransucrase activity.  

PubMed

This study investigates the buffering effects of calcium salts in kimchi on total acidity, microbial population, and dextransucrase activity. Calcium chloride or calcium carbonate was added in dongchimi-kimchi, a watery-radish kimchi, and their effects on various biochemical attributes were analyzed. The addition of 0.1% calcium chloride produced a milder decrease in the pH after 24 days of incubation, which allowed the lactic acid bacteria to survive longer than in the control. In particular, the heterofermentative Leuconostoc genus population was 10-fold higher than that in the control. When sucrose and maltose were also added along with the calcium salts, the dextransucrase activity in the kimchi was elevated and a higher concentration of isomaltooligosaccharides was synthesized when compared with the control. Calcium chloride was determined as a better activator compound of dextransucrase than calcium carbonate, probably because of its higher solubility. Therefore, the results of this study confirm the ability of the proposed approach to modulate the kimchi fermentation process and possibly enhance the quality of kimchi based on the addition of dietary calcium salts. PMID:20075632

Chae, Seo Eun; Moon, Jin Seok; Jung, Jee Yun; Kim, Ji-Sun; Eom, Hyun-Ju; Kim, So-Young; Yoon, Hyang Sik; Han, Nam Soo

2009-12-01

48

Calcium  

MedlinePLUS

... it from: Dairy products. Low-fat milk, yogurt, cheese, and cottage cheese are good sources of calcium. Veggies. You'll ... burritos or wraps. Fill them with eggs and cheese for breakfast; turkey, cheese, lettuce, tomato, and light ...

49

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

50

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

PubMed Central

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

Thai, Van Viet

2010-01-01

51

Prevention of volatile fatty acids production and limitation of odours from winery wastewaters by denitrification.  

PubMed

The effect of the addition of nitrate to winery wastewaters to control the formation of VFA in order to prevent odours during storage and treatment was studied in batch bioreactors at different NO(3)/chemical oxygen demand (COD) ratios and at full scale in natural evaporation ponds (2 x 7000 m(2)) by measuring olfactory intensity. In the absence of nitrate, butyric acid (2304 mgL(-1)), acetic acid (1633 mgL(-1)), propionic acid (1558 mgL(-1)), caproic acid (499 mgL(-1)) and valeric acid (298 mgL(-1)) were produced from reconstituted winery wastewater. For a ratio of NO(3)/COD=0.4 gg(-1), caproic and valeric acids were not formed. The production of butyric and propionic acids was reduced by 93.3% and 72.5%, respectively, at a ratio of NO(3)/COD=0.8, and by 97.4% and 100% at a ratio of NO(3)/COD=1.2 gg(-1). Nitrate delayed and decreased butyric acid formation in relation to the oxidoreduction potential. Studies in ponds showed that the addition of concentrated calcium nitrate (NITCAL) to winery wastewaters (3526 m(3)) in a ratio of NO(3)/COD=0.8 inhibited VFA production, with COD elimination (94%) and total nitrate degradation, and no final nitrite accumulation. On the contrary, in ponds not treated with nitrate, malodorous VFA (from propionic to heptanoïc acids) represented up to 60% of the COD. Olfactory intensity measurements in relation to the butanol scale of VFA solutions and the ponds revealed the pervasive role of VFA in the odour of the untreated pond as well as the clear decrease in the intensity and not unpleasant odour of the winery wastewater pond enriched in nitrates. The results obtained at full scale underscored the feasibility and safety of the calcium nitrate treatment as opposed to concentrated nitric acid. PMID:17467770

Bories, André; Guillot, Jean-Michel; Sire, Yannick; Couderc, Marie; Lemaire, Sophie-Andréa; Kreim, Virginie; Roux, Jean-Claude

2007-07-01

52

Phosphate coating on pyrite to prevent acid mine drainage  

Microsoft Academic Search

Acid mine drainage (AMD) is a serious environmental problem that preoccupies the Canadian Mineral Industry. Considerable amounts of money are spent every year in an effort to prevent or reduce the acid mine drainage phenomenon. AMD occurs when sulfide minerals (ex. pyrite) contained in rock are exposed to air and water and subsequently oxidize to produce low pH water. This

Kostas Fytas; Bill Evangelou

1998-01-01

53

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

54

Performance of calcium deficient hydroxyapatite–polyglycolic acid composites: an in vitro study  

Microsoft Academic Search

The strategic incorporation of bioresorbable polymeric additives to calcium-deficient hydroxyapatite cement may provide short-term\\u000a structural reinforcement and modify the modulus to closer match bone. The longer-term resorption properties may also be improved,\\u000a creating pathways for bone in-growth. The aim of this study was to investigate the resorption process of a calcium phosphate\\u000a cement system containing either in polyglycolic acid tri-methylene

Nicholas Dunne; Valerie Jack; Rochelle O’Hara; David Farrar; Fraser Buchanan

2010-01-01

55

Calcium Signals Activated by Arachidonic Acid in Embryonic Chick Ciliary Ganglion Neurons  

Microsoft Academic Search

Arachidonic acid (AA, 20:4) has been reported to modulate a variety of calcium-permeable ionic channels, both in the plasma membrane and in the endoplasmic reticulum. We have studied the effects of AA on calcium signaling in a well-characterized model of developing peripheral neurons, embryonic chick ciliary ganglion neurons in culture. When given at low non-micellar concentrations (5 ?M), in the

Jessica Erriquez; Alessandra Gilardino; Paolo Ariano; Luca Munaron; Davide Lovisolo; Carla Distasi

2005-01-01

56

Nicotinic acid modulates intracellular calcium concentration and disassembles the cytoskeleton  

PubMed Central

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

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

2014-01-01

57

Nicotinic acid modulates intracellular calcium concentration and disassembles the cytoskeleton.  

PubMed

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

Li, Jiejing; Li, Yanxi; Zhang, Penghui; Niu, Hua; Shi, Yu

2014-12-01

58

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

PubMed Central

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

2013-01-01

59

Calcium-dependent phospholipid catabolism and arachidonic acid mobilization in cerebral minces  

Microsoft Academic Search

Cerebral minces were used to investigate the role of calcium influx on trauma-induced alterations of brain lipid metabolism.\\u000a Cerebral phospholipids, nonpolar lipids, and free fatty acids were radiolabeled in vivo with [3H]arachidonic acid. Tissue incubation stimulated the time-dependent catabolism of choline and inositol glycerophospholipids,\\u000a and resulted in the accumulation of [3H]free fatty acids. These effects were attenuated in Ca2+-free incubations,

Derek S. Damron; Robert V. Dorman

1990-01-01

60

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

61

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

62

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

PubMed

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

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

1999-05-15

63

Improvement of Tear Trough by Monophasic Hyaluronic Acid and Calcium Hydroxylapatite  

PubMed Central

Tear trough deformities are a sign of facial aging. The anatomical base is well understood. In many patients, minimal invasive surgical procedures are useful to improve appearance. Here, the authors describe the use of monophasic hyaluronic acid dermal filler and calcium hydroxylapatite injection for correction. Forty female patients with a mean age of 50 years have been treated. On average, an improvement of one class of Hidman’s severity score could be achieved by single treatment. Mean duration of the effect was 10.1 months for hyaluronic acid and 12.8 months for calcium hydroxylapatite. Adverse effects were mild and temporary. Patients satisfaction was high (95%). PMID:25371770

2014-01-01

64

Firmness and cell wall characteristics of pasteurized jalapeno pepper rings affected by acetic acid, calcium chloride and preheating  

E-print Network

pasteurization and storage, especially when high acid brines are used. Development of treatments to retard softening may result in a higher quality product. This study was undertaken to investigate the effects of calcium chloride (CaCI2), acetic acid...

Burma, Prashanthi V

2012-06-07

65

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

66

Vibratonal Spectra and DFT calculations of dipicolinic acid and its calcium salt  

Microsoft Academic Search

The infrared and Raman spectra of dipicolinic acid (DPA) and calcium dipicolinate have been recorded in the solid phase and their vibrations have been assigned. DFT calculations using B3LYP\\/6-311++G** have been used to calculate the spectra of the free dipicolinic acid molecule and its ion in an environment free of intermolecular interactions. Calculations have also been carried out to better

Kathleen McCann; Jaan Laane

2007-01-01

67

Sphingosine 1Phosphate Mobilizes Sequestered Calcium, Activates Calcium Entry, and Stimulates Deoxyribonucleic Acid Synthesis in Thyroid FRTL-5 Cells  

Microsoft Academic Search

Sphingosine 1-phosphate (SPP) potently mobilizes sequestered cal- cium and is a mitogen in several cell types. In the present investi- gation, we have evaluated the effect of SPP on intracellular free calcium concentration ((Ca21)i) and synthesis of DNA in thyroid FRTL-5 cells. SPP rapidly and transiently mobilized sequestered calcium and stimulated entry of extracellular calcium. The entry of calcium, but

KID TORNQUIST; PIA SAARINEN; MINNA VAINIO; MIKAEL AHLSTROM

1997-01-01

68

Luteolin prevents uric acid-induced pancreatic ?-cell dysfunction  

PubMed Central

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

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

2014-01-01

69

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

70

Intra-Arterial Calcium Gluconate Treatment After Hydrofluoric Acid Burn of the Hand  

SciTech Connect

Hydrofluoric acid (HF) is a colorless corrosive acid used in different industrial branches. Exposure to HF typically results from spills, and most often the hand or fingers are involved. Tissue damage through cutaneous HF exposure occurs through corrosive burns due to the free hydrogen ions and through skin penetration of the fluoride ions, causing a depletion of calcium in the deep tissue layers, ultimately leading to cell death and tissue necrosis. Treatment of HF burns consists of thoroughly flushing the exposed area with water and applying calcium gluconate gel to the skin. If topical treatment does not suffice, subcutaneous injections, as well as intravascular-both intravenous and intra-arterial-calcium gluconate therapy, have been advocated. We report for the first time a case of HF burn of the hand and digits associated with vasospasm. Pain and vasospasm were successfully treated by repeated intra-arterial calcium gluconate injection. We conclude that intra-arterial calcium gluconate injection is a successful and well-tolerated therapy for HF burn associated with Raynaud's syndrome. Intra-arterial injection allows for well-controlled delivery of therapy as well as assessment of the vascular status.

Thomas, D., E-mail: daniel.thomas@ukb.uni-bonn.de; Jaeger, U. [Radiologische Universitaetsklinik, Universitaet Bonn (Germany); Sagoschen, I. [Klinikum der Johannes Gutenberg Universitaet, Poison Control Center, Medizinische Klinik und Poliklinik II (Germany); Lamberti, C. [Universitaet Bonn, Medizinische Klinik und Poliklinik I (Germany); Wilhelm, K. [Radiologische Universitaetsklinik, Universitaet Bonn (Germany)

2009-01-15

71

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

72

Renal calcium and magnesium excretion during vasopressin administration into sheep with acid or alkaline urine.  

PubMed Central

1. The proposition that changes in renal calcium excretion during vasopressin administration are positively correlated with concurrent changes in urine hydrogen ion concentration was tested by administration of vasopressin into twelve conscious diuresing sheep receiving either alkalinizing or acidifying infusions. 2. Vasopressin-induced antidiuresis in sheep with alkaline urine was associated with significant increases in urinary pH and decreases in the rate of calcium excretion whereas antidiuresis in sheep with acid urine was associated with significant decreases in urinary pH and no consistent effect on calcium excretion. 3. Magnesium excretion increased during vasopressin administration in most experiments regardless of urinary pH changes. 4. Vasopressin administration did not significantly alter the rate of excretion of sodium, potassium, chloride and phosphate or the rates of sodium, potassium, chloride, inulin, para-aminohippurate and osmolal clearance in sheep with either acid or alkaline urine. Potassium excretion and clearance in sheep with alkaline ruine was higher than that of sheep with acid urine during vasopressin infusion. 5. The results support the hypothesis that changes in renal tubular hydrogen ion concentration or bicarbonate concentration caused by water reabsorption from the collecting duct and possibly the late distal tubule could be part of the explanation for changes in renal calcium excretion which occur during vasopressin-induced antidiuresis. PMID:41939

Beal, A M

1979-01-01

73

Habit modification of calcium carbonate in the presence of malic acid  

NASA Astrophysics Data System (ADS)

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

Mao, Zhaofeng; Huang, Jianhua

2007-02-01

74

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

75

Diabetes induces and calcium channel blockers prevent cardiac expression of proapoptotic thioredoxin-interacting protein.  

PubMed

Cardiomyocyte apoptosis is a critical process in the pathogenesis of ischemic and diabetic cardiomyopathy, but the mechanisms are not fully understood. Thioredoxin-interacting protein (TXNIP) has recently been shown to have deleterious effects in the cardiovascular system and we therefore investigated whether it may also play a role in diabetes-associated cardiomyocyte apoptosis. In fact, TXNIP expression was increased in H9C2 cardiomyocytes incubated at high glucose, and cardiac expression of TXNIP and cleaved caspase-3 were also elevated in vivo in streptozotocin- and obesity-induced diabetic mice. Together, these findings not only suggest that TXNIP is involved in diabetic cardiomyopathy but also that it may represent a novel therapeutic target. Surprisingly, testing putative TXNIP modulators revealed that calcium channel blockers reduce cardiomyocyte TXNIP transcription and protein levels in a dose-dependent manner. Oral administration of verapamil for 3 wk also reduced cardiac TXNIP expression in mice even in the face of severe diabetes, and these reduced TXNIP levels were associated with decreased apoptosis. To determine whether lack of TXNIP can mimic the verapamil-induced decrease in apoptosis, we used TXNIP-deficient HcB-19 mice, harboring a natural nonsense mutation in the TXNIP gene. Interestingly, we found significantly reduced cleaved caspase-3 levels in HcB-19 hearts, suggesting that TXNIP plays a critical role in cardiac apoptosis and that the verapamil effects were mediated by TXNIP reduction. Thus our results suggest that TXNIP reduction is a powerful target to enhance cardiomyocyte survival and that agents such as calcium channel blockers may be useful in trying to achieve this goal and prevent diabetic cardiomyopathy. PMID:19258488

Chen, Junqin; Cha-Molstad, Hyunjoo; Szabo, Anna; Shalev, Anath

2009-05-01

76

Diabetes induces and calcium channel blockers prevent cardiac expression of proapoptotic thioredoxin-interacting protein  

PubMed Central

Cardiomyocyte apoptosis is a critical process in the pathogenesis of ischemic and diabetic cardiomyopathy, but the mechanisms are not fully understood. Thioredoxin-interacting protein (TXNIP) has recently been shown to have deleterious effects in the cardiovascular system and we therefore investigated whether it may also play a role in diabetes-associated cardiomyocyte apoptosis. In fact, TXNIP expression was increased in H9C2 cardiomyocytes incubated at high glucose, and cardiac expression of TXNIP and cleaved caspase-3 were also elevated in vivo in streptozotocin- and obesity-induced diabetic mice. Together, these findings not only suggest that TXNIP is involved in diabetic cardiomyopathy but also that it may represent a novel therapeutic target. Surprisingly, testing putative TXNIP modulators revealed that calcium channel blockers reduce cardiomyocyte TXNIP transcription and protein levels in a dose-dependent manner. Oral administration of verapamil for 3 wk also reduced cardiac TXNIP expression in mice even in the face of severe diabetes, and these reduced TXNIP levels were associated with decreased apoptosis. To determine whether lack of TXNIP can mimic the verapamil-induced decrease in apoptosis, we used TXNIP-deficient HcB-19 mice, harboring a natural nonsense mutation in the TXNIP gene. Interestingly, we found significantly reduced cleaved caspase-3 levels in HcB-19 hearts, suggesting that TXNIP plays a critical role in cardiac apoptosis and that the verapamil effects were mediated by TXNIP reduction. Thus our results suggest that TXNIP reduction is a powerful target to enhance cardiomyocyte survival and that agents such as calcium channel blockers may be useful in trying to achieve this goal and prevent diabetic cardiomyopathy. PMID:19258488

Chen, Junqin; Cha-Molstad, Hyunjoo; Szabo, Anna; Shalev, Anath

2009-01-01

77

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

78

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

79

Calcium Antagonists Inhibit Sustained Gibberellic Acid-Induced Growth of Avena (Oat) Stem Segments.  

PubMed Central

The elongation response of Avena sativa (oat) stem segments to gibberellic acid (GA3) is of large magnitude, with high hormonal sensitivity and specificity, but without cell division activity. This system is therefore an excellent model for mechanistic studies on higher plant cell elongation and the action of gibberellin. At millimolar concentrations, the calcium antagonists verapamil, D-600, nicardipine, diltiazem, bepridil, 8-(N,N,-diethylamino)-octyl-3,4,5-trimethoxybenzoate HCl, and lanthanum substantially inhibited the growth of GA3-treated segments but had no effect on the elongation of nonhormone-treated segments. Although verapamil reduced the maximum growth rate and caused premature cessation of growth, even preincubation of the segments with the drug prior to treatment with GA3 failed to inhibit the earliest measured stimulation of growth by the hormone. Inhibition by verapamil was not reversed by increased concentrations of GA3 or calcium. Neither the calcium ionophore A23187 nor agonist BAY K 8644 had any effect on growth. Light microscopic examination of epidermal peels from antagonist-treated internodal tissue revealed no obvious differences from the control except that the cells were not as elongated. Although these results may support a role for calcium ion movement in maintaining the GA3-induced growth of Avena stem segments, they do not support the involvement of calcium ion movement in the hormone-mediated initiation of growth. PMID:12231695

Montague, M. J.

1993-01-01

80

Calcium Carbonate  

MedlinePLUS

... heart. Calcium carbonate also is used as an antacid to relieve heartburn, acid indigestion, and upset stomach. ... use.Do not take calcium carbonate as an antacid for more than 2 weeks unless your doctor ...

81

Oleic acid induces intracellular calcium mobilization, MAPK phosphorylation, superoxide production and granule release in bovine neutrophils.  

PubMed

Oleic acid (OA) is a nonesterified fatty acid that is released into the blood during lipomobilization at the time of calving in cows, a period where increased risk of infection and acute inflammation is observed. These data suggest potential OA-mediated regulation of innate immune responses. In the present study, we assessed the effects of OA on intracellular calcium release, ERK1/2 phosphorylation, superoxide production, CD11b expression and matrix metalloproteinase-9 (MMP-9) release in bovine neutrophils. Furthermore, the presence of GPR40, an OA receptor, was assessed by RT-PCR, immunoblotting and confocal microscopy. OA induced, in a dose-dependent manner, intracellular calcium mobilization, superoxide production and CD11b expression in bovine neutrophils; these effects were reduced by the intracellular chelating agent BAPTA-AM. OA also induced ERK2 phosphorylation and MMP-9 release. RT-PCR analysis detected mRNA expression of a bovine ortholog of the GPR40 receptor. Using a polyclonal antibody against human GPR40, we detected a protein of 31kDa by immunoblotting that was localized predominately in the plasma membrane. The selective agonist of GPR40, GW9508, induced intracellular calcium mobilization and ERK2 phosphorylation. In conclusion, OA can modulate bovine neutrophil responses in an intracellular calcium-dependent manner; furthermore, these responses could be induced by GPR40 activation. PMID:21575602

Hidalgo, Maria A; Nahuelpan, Carla; Manosalva, Carolina; Jara, Evelyn; Carretta, Maria D; Conejeros, Ivan; Loaiza, Anitsi; Chihuailaf, Ricardo; Burgos, Rafael A

2011-06-01

82

Effect of Calcium Nitrate and Boric Acid Sprays on Fruit Set, Yield and Fruit Quality of cv. Amhat Date Palm  

E-print Network

Abstract: The objective of the present study is to investigate the impact of spraying boric acid and/or calcium nitrate on fruit set, yield and fruit of cv. Amhat date palm. The present study was carried out during 2011/2012 growing seasons. Palms were sprayed with boric acid at 250 and 500 ppm and calcium nitrate at 1 and 2 % as individual application or in a combination between boric acid and calcium nitrate concentrations treatments. In general, results indicated that spraying date palm inflorescence with both boric acid and/or calcium nitrate had a significant effect on fruit set, yield and fruit physical and chemical characteristics of Amhat date palm. The superior treatment concerning yield and fruit quality was spraying boric acid at 500 ppm combined with calcium nitrate at 2 % in the two experimental seasons. Key words: Date palm Fruit set Yield Fruit quality Boric acid Calcium nitrate INTRODUCTION synthesis, transport of sugars and carbohydrate metabolism [12]. Calcium is conceder as one of the most Date palm (Phoenix dactylifera L.) is concerned as important minerals determining the quality of fruit since it one of the important crops in arid and semi-arid regions of is required for cell elongation and cell division [13]. Till the world. Date palm is one of the ancient domestic fruit now, a little attention have been paid towards nutrient

S. M. A. Sarrwy; E. G. Gadalla; E. A. M. Mostafa

83

[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

84

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

PubMed

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

Windelborn, James A; Lipton, Peter

2008-07-01

85

Morphological modifications of electrodeposited calcium phosphate coatings under amino acids effect  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

86

A calcium and free fatty acid-modulated protein kinase as putative effector of the fusicoccin 14-3-3 receptor.  

PubMed Central

A protein kinase that is activated by calcium and cis-unsaturated fatty acids has been characterized from oat (Avena sativa L.) root plasma membranes. The kinase phosphorylates a synthetic peptide with a motif (-R-T-L-S-) that can be phosphorylated by both protein kinase C (PKC) and calcium-dependent protein kinase (CDPK)-type kinases. Calphostin C and chelerythrine, two PKC inhibitors, completely inhibited the kinase activity with values of inhibitor concentration for 50% inhibition of 0.7 and 30 microns, respectively. At low Ca2+ concentrations cis-unsaturated fatty acids (linolenic acid, linoleic acid, arachidonic acid, and oleic acid) stimulated the kinase activity almost 10-fold. The two inhibitors of the kinase, calphostin C and chelerythrin, strongly reduced the fusicoccin (FC)-induced H+ extrusion, and the activators of the kinase, the cis-unsaturated fatty acids, prevented [3H]FC binding to the FC 14-3-3 receptor. CDPK antibodies cross-reacted with a 43-kD band in the plasma membrane and in a purified FC receptor fraction. A polypeptide with the same apparent molecular mass was recognized by a synthetic peptide that has a sequence homologous to the annexin-like domain from barely 14-3-3. The possibility of the involvement of a kinase, with properties from both CDPK and PKC, and a phospholipase A2 in the FC Signal transduction pathway is discussed. PMID:8754686

van der Hoeven, P C; Siderius, M; Korthout, H A; Drabkin, A V; de Boer, A H

1996-01-01

87

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

SciTech Connect

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

SUGAMA,T.; BROTHERS, L.E.

2005-01-01

88

[Calcium ions, glutaminate acid, hypothalamic-pituitary-adrenal axis, calcium dependent ATP-ase as causes of oxidative damage in depression patients (part II)].  

PubMed

Depressive disorder is still a rising and important problem in the modern world, it affects about 15% of the population. Present forms of treatment are effective in about 70% and require monthly therapy which sometimes causes side effects. Last decade studies paid attention to theories different to monoaminergic and to neurodegenerative changes mainly in the limbic system of hippocampus. In this article authors show a relationship between calcium ions, glutaminergic transduction and disfunction of hypothalamic-pituitary-adrenal (HPA) axis. They also take into account the activity of calcium dependent ATPase and its influence on overproduction of reactive oxygen species in the central neuron system (CNS). In the second part authors conclude that deregulation of calcium ions concentration in and out of cells and decreased activity of calcium dependent ATPase stimulate tricarboxylic acid cycle, oxidative phosphorilation. Mitochondria work faster and consume more oxygen. It correlates well with overproduction of reactive oxygen species (RFT). Above process results in neurons apoptosis and necrosis. PMID:18634258

Ga?ecki, Piotr; Florkowski, Antoni; Mrowicka, Ma?gorzata; Pietras, Tadeusz; Ga?ecka, Elzbieta

2008-01-01

89

Inhibition of calcium-independent phospholipase A2 prevents inflammatory mediator production in pulmonary microvascular endothelium.  

PubMed

Inhalation of allergens can result in mast cell degranulation and release of granule contents, including tryptase, in the lung. Injury to human pulmonary microvascular endothelial cells (HMVEC-L) can also result in activation of the coagulation cascade and thrombin generation. We hypothesize that these proteases activate calcium-independent phospholipase A2 (iPLA2), in HMVEC-L, leading to the production of membrane phospholipids-derived inflammatory mediators. Both thrombin and tryptase stimulation of HMVEC-L increased iPLA2 activity that was inhibited by pretreatment with the iPLA2 selective inhibitor bromoenol lactone (BEL). Arachidonic acid and prostaglandin I2 (PGI2) release were also increased in tryptase and thrombin stimulated cells and inhibited by BEL pretreatment. Pretreating the endothelial cells with AACOCF3 a cytosolic PLA2 inhibitor did not inhibit tryptase or thrombin induced arachidonic acid and PGI2 release. In addition thrombin and tryptase also increased HMVEC-L platelet activating factor (PAF) production that significantly contributes to the recruitment and initial adherence of polymorphonuclear neutrophils (PMN) to the endothelium. Tryptase or thrombin stimulated increase in PMN adherence to the endothelium was inhibited by pretreatment of HMVEC-L with BEL or pretreatment of PMN with CV3988, a PAF receptor specific antagonist. Collectively, these data support our hypothesis that iPLA2 activity is responsible for membrane phospholipid hydrolysis in response to tryptase or thrombin stimulation in HMVEC-L. Therefore selective inhibition of iPLA2 may be a pharmacological target to inhibit the early inflammation in pulmonary vasculature that occurs as a consequence of mast cell degranulation or acute lung injury. PMID:19059366

Rastogi, Prerna; McHowat, Jane

2009-02-28

90

Vibratonal Spectra and DFT calculations of dipicolinic acid and its calcium salt  

NASA Astrophysics Data System (ADS)

The infrared and Raman spectra of dipicolinic acid (DPA) and calcium dipicolinate have been recorded in the solid phase and their vibrations have been assigned. DFT calculations using B3LYP/6-311++G** have been used to calculate the spectra of the free dipicolinic acid molecule and its ion in an environment free of intermolecular interactions. Calculations have also been carried out to better understand the effects of intermolecular hydrogen bonding and the interactions between water and DPA. The calculated frequencies agree well with the experimental values after scaling.

McCann, Kathleen; Laane, Jaan

2007-10-01

91

The relationship between blood carbon dioxide, acid-base balance and calcium metabolism in the hyperthermic laying hen  

E-print Network

THE RELATIONSHIP BETWEEN BLOOD CARBON DIOXIDE, ACID-BASE BALANCE AND CALCIUM METABOLISM IN THE HYPERTHERMIC LAYING HEN A Thesis by YOSHITAKA ONO Subrnittcd to thc Office of Graduate Studies of Texas AA, M University in partial I...'ulfillmcnt of thc requirements for thc dcgrcc of MASTER OF SCIENCE Dcccmbcr 1988 Major Sulajccu Poultry Scicncc THE RELATIONSHIP BETWEEN BLOOD CARBON DIOXIDE, ACID-BASE BALANCE AND CALCIUM METABOLISM IN THE HYPERTHERMIC LAYING HEN A Thesis by YOSHITAKA ONO...

Ono, Yoshitaka

2012-06-07

92

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

93

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

94

N-3 fatty acids for prevention of cardiovascular disease.  

PubMed

Cardiovascular disease (CVD) is the leading cause of death in the USA. A diet enriched with n-3 fatty acids (FA) has been reported to play an important role in preventing the development of CVD. Prior studies have demonstrated beneficial effects of n-3 FA on hypertriglyceridemia, blood pressure, inflammation, endothelial function, and platelet function. However, data on the relation of n-3 FA consumption with CVD risk remain inconsistent. This paper reviews current evidence on the effects of n-3 FA on CVD, CVD risk factors, and potential biologic mechanisms. Last, we discuss major limitations of currently available data and future directions in the field. PMID:25214423

Khawaja, Owais A; Gaziano, John M; Djoussé, Luc

2014-11-01

95

Habit modification of calcium carbonate in the presence of malic acid  

SciTech Connect

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

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

2007-02-15

96

Folic acid and primary prevention of birth defects.  

PubMed

Birth defects (BDs) are an important public health problem, due to their overall incidence, occurring in 2-3% of live births in European Union. Neural tube defects (NTDs) are among major NTDs, due to their severity and relatively high incidence; in the meanwhile NTDs are also the most effectively preventable BDs to date. In particular, an adequate folic acid (FA) intake reduces both the occurrence and the recurrence of NTDs; FA is the synthetic form of folates, naturally occurring vitamins in a number of foods, especially vegetables. The daily intake of 0.4 mg of FA should be recommended to all women of childbearing age who plan to become pregnant. The Italian Network for Primary Prevention of BDs through FA Promotion has achieved a significant improvement in FA awareness and use in the periconceptional period. Nevertheless, primary prevention of BDs needs to make further progress; the Italian National Centre for Rare Diseases participates in european sureveillance of congenital anomalies (EUROCAT) Joint Action as coordinator of activities on the effectiveness of BDs prevention. Mandatory food fortification with FA has not been introduced in any European country. The health benefits of FA in reducing the risk of NTDs are undisputed; however mechanistic and animal studies suggest a relationship between high FA intakes and increased cancer promotion, while human studies are still inconsistent and inconclusive. A Working Group organized by the European Food Safety Authority pointed out significant uncertainties about fortification safety and the need for more studies; currently, FA intake from fortified foods and supplements should not exceed 1 mg/day in adults. In conclusion, based on up-to-date scientific evidence, the Italian Network strategy pivots on periconceptional supplementation integrated with promotion of healthy eating habits, support to health education, enhancing the role of women in managing life choices about their health and pregnancy and increasing the scientific knowledge about BDs primary prevention. PMID:21915935

Taruscio, Domenica; Carbone, Pietro; Granata, Orietta; Baldi, Francesca; Mantovani, Alberto

2011-01-01

97

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

PubMed Central

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

2013-01-01

98

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

SciTech Connect

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

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

2009-05-15

99

Dissolution mechanism of calcium apatites in acids: A review of literature  

PubMed Central

Eight dissolution models of calcium apatites (both fluorapatite and hydroxyapatite) in acids were drawn from the published literature, analyzed and discussed. Major limitations and drawbacks of the models were conversed in details. The models were shown to deal with different aspects of apatite dissolution phenomenon and none of them was able to describe the dissolution process in general. Therefore, an attempt to combine the findings obtained by different researchers was performed which resulted in creation of the general description of apatite dissolution in acids. For this purpose, eight dissolution models were assumed to complement each other and provide the correct description of the specific aspects of apatite dissolution. The general description considers all possible dissolution stages involved and points out to some missing and unclear phenomena to be experimentally studied and verified in future. This creates a new methodological approach to investigate reaction mechanisms based on sets of affine data, obtained by various research groups under dissimilar experimental conditions.

Dorozhkin, Sergey V

2012-01-01

100

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

101

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

102

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. PMID:21504057

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

2012-01-01

103

Linoleic acid increases adhesion, chemotaxis, granule release, intracellular calcium mobilisation, MAPK phosphorylation and gene expression in bovine neutrophils.  

PubMed

Neutrophils are critical to the innate immune response; therefore, the proper function of neutrophils is critical to avoid the development of certain diseases. Linoleic acid, a polyunsaturated long-chain fatty acid, is one of the most abundant long-chain fatty acids found in the plasma of cows after giving birth. In this study, we evaluated the effects of linoleic acid treatment on bovine neutrophil adhesion, chemotaxis, metalloproteinase (MMP)-9 release, CD11b expression, intracellular calcium mobilisation, mitogen-activating protein kinase (MAPK) phosphorylation and COX-2 and IL-8 expression. Bovine neutrophils isolated from healthy heifers were incubated with different concentrations of linoleic acid, and then neutrophil responses were evaluated. Our results show that the treatment of neutrophils with 100 ?M linoleic acid increased their adhesion to the bovine endothelial cell line CPA47. The results of a transwell migration assay revealed that linoleic acid could also promote the chemotaxis of bovine neutrophils. Furthermore, linoleic acid treatment increased MMP-9 activity and CD11b cell surface expression in neutrophils. Fifty and 100 ?M linoleic acid also increased intracellular calcium mobilisation in neutrophils loaded with Fluo-4 AM dye. Linoleic acid also rapidly (2-5 min) stimulated the phosphorylation of ERK1/2 and p38 MAPK as evaluated by immunoblot. Finally, COX-2 and IL-8 mRNA expression increased after 2h of linoleic acid treatment. In conclusion, linoleic acid stimulates adhesion, chemotaxis, granule release and intracellular responses in bovine neutrophils. PMID:23267746

Mena, Jaqueline; Manosalva, Carolina; Ramirez, Ruben; Chandia, Lhia; Carroza, Daniel; Loaiza, Anitsi; Burgos, Rafael A; Hidalgo, Maria A

2013-02-15

104

Sigma-1 receptor activation prevents intracellular calcium dysregulation in cortical neurons during in vitro ischemia.  

PubMed

Sigma receptors are putative targets for neuroprotection following ischemia; however, little is known on their mechanism of action. One of the key components in the demise of neurons following ischemic injury is the disruption of intracellular calcium homeostasis. Fluorometric calcium imaging was used to examine the effects of sigma receptor activation on changes in intracellular calcium concentrations ([Ca(2+)](i)) evoked by in vitro ischemia in cultured cortical neurons from embryonic rats. The sigma receptor agonist, 1,3-di-o-tolyl-guanidine (DTG), was shown to depress [Ca(2+)](i) elevations observed in response to ischemia induced by sodium azide and glucose deprivation. Two sigma receptor antagonists, metaphit [1-(1-(3-isothiocyanatophenyl)-cyclohexyl)-piperidine] and BD-1047 (N-[2-3,4-dichlorophenyl)-ethyl]-N-methyl-2-(dimethylamino)ethylamine), were shown to blunt the ability of DTG to inhibit ischemia-evoked increases in [Ca(2+)](i), revealing that the effects are mediated by activation of sigma receptors and not via the actions of DTG on nonspecific targets such as N-methyl-d-aspartate receptors. DTG inhibition of ischemia-induced increases in [Ca(2+)](i) was mimicked by the sigma-1 receptor-selective agonists, carbetapentane, (+)-pentazocine and PRE-084 [2-(4-morpholinethyl) 1-phenylcyclohexanecarboxylate hydrochloride], but not by the sigma-2-selective agonist, ibogaine, showing that activation of sigma-1 receptors is responsible for the effects. In contrast, DTG, carbetapentane, and ibogaine blocked spontaneous, synchronous calcium transients observed in our preparation at concentrations consistent with sigma receptor-mediated effects, indicating that both sigma-1 and sigma-2 receptors regulate events that affect [Ca(2+)](i) in cortical neurons. Our studies show that activation of sigma receptors can ameliorate [Ca(2+)](i) dysregulation associated with ischemia in cortical neurons and, thus, identify one of the mechanisms by which these receptors may exert their neuroprotective properties. PMID:16988055

Katnik, Christopher; Guerrero, Waldo R; Pennypacker, Keith R; Herrera, Yelenis; Cuevas, Javier

2006-12-01

105

The Transport of Indole-3-Acetic Acid in Boron- and Calcium-Deficient Sunflower Hypocotyl Segments 1  

PubMed Central

Transfer of sunflower (Helianthus annuus L. cv Russian Mammoth) seedlings from complete nutrient solution to solutions deficient in either boron or calcium resulted in a steady decline in the rate of auxin transport, compared to seedlings that remained in the complete solution. In seedlings transferred to solutions deficient in both B and Ca, the decline in auxin transport was greater than seedlings deficient in only one element. The transfer of B- or Ca-deficient seedlings back to the complete solution prevented further decline in auxin transport, but auxin transport did not increase to the same level as seedlings maintained in complete solution. The significant reduction in auxin transport during the early stages of B or Ca deficiency was not related to (a) reduced growth rate of the hypocotyl, (b) increased acropetal movement of auxin, or (c) lack of respiratory substrates in the hypocotyl. In addition, no difference was found in the water-extractable total and ionic Ca in B-deficient and control nondeficient hypocotyls, indicating a direct effect of B on auxin transport, rather than indirectly by affecting Ca absorption. The rate of auxin transport in hypocotyls deficient in either B or Ca, was inversely correlated with K+ leakage and rate of respiration. The data presented strongly support the view that there are separate sites for B and Ca in the basipetal transport of the plant hormone indoleacetic acid. PMID:16664871

Tang, Pauline M.; dela Fuente, Rollo K.

1986-01-01

106

Dairy Products, Dietary Calcium and Bone Health: Possibility of Prevention of Osteoporosis in Women: The Polish Experience  

PubMed Central

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 large 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

2013-01-01

107

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

108

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

109

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

110

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

111

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

112

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2011 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2011-04-01

113

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2010 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2010-04-01

114

21 CFR 184.1199 - Calcium gluconate.  

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2014-04-01

115

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2013 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2013-04-01

116

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2012 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2012-04-01

117

Capsaicin prevents kainic acid-induced epileptogenesis in mice.  

PubMed

Epilepsy is a neurodegenerative disease with periodic occurrences of spontaneous seizures as the main symptom. The aim of this study was to investigate the neuroprotective effects of capsaicin, the major ingredient of hot peppers, in a kainic acid (KA)-induced status epilepticus model. After intraperitoneal injections of KA (30mg/kg) in 8-week-old male ICR mice, the animals were treated subcutaneously with capsaicin (0.33mg/kg or 1mg/kg) and then examined for any anti-ictogenic, hypothermic, antioxidative, anti-inflammatory, and anti-apoptotic effects of the capsaicin treatment 3 days after KA treatment. KA injections significantly enhanced neurodegenerative conditions but co-injection with capsaicin reduced the detrimental effects of KA in a dose-dependent manner in mice. The co-administered group that received KA and 1mg/kg of capsaicin showed significantly decreased behavioral seizure activity and body temperature for 3h and also remarkably blocked intense and high-frequency seizure discharges in the parietal cortex for 3 days compared with those that received KA alone. Capsaicin treatment significantly diminished the levels of oxidant activity and malondialdehyde concentration and increased the antioxidant activity in the blood and brain of KA-treated mice. In addition, capsaicin significantly lowered the KA-induced increase in the concentration of the cytokines IL-1? and TNF-? in the brain. Furthermore, co-treatment of KA and capsaicin (1mg/kg) resulted in considerably decreased apoptotic cell death in the cornu ammonis sections of the hippocampus compared with that seen in the KA-alone group. These findings indicate that capsaicin is preventative for the epileptogenesis induced by KA in mice. PMID:21333704

Lee, Tae-Hee; Lee, Jong-Geol; Yon, Jung-Min; Oh, Ki-Wan; Baek, In-Jeoung; Nahm, Sang-Soep; Lee, Beom Jun; Yun, Young Won; Nam, Sang-Yoon

2011-05-01

118

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. PMID:23616533

Subramanian, Jaichandar; Dye, Louis; Morozov, Alexei

2013-01-01

119

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

120

Hippuric Acid as a Significant Regulator of Supersaturation in Calcium Oxalate Lithiasis: The Physiological Evidence  

PubMed Central

At present, the clinical significance of existing physicochemical and biological evidence and especially the results we have obtained from our previous in vitro experiments have been analyzed, and we have come to the conclusion that hippuric acid (C6H5CONHCH2COOH) is a very active solvent of Calcium Oxalate (CaOX) in physiological solutions. Two types of experiments have been discussed: clinical laboratory analysis on the urine excretion of hippuric acid (HA) in patients with CaOX lithiasis and detailed measurements of the kinetics of the dissolution of CaOX calculi in artificial urine, containing various concentrations of HA. It turns out that the most probable value of the HA concentration in the control group is approximately ten times higher than the corresponding value in the group of the stone-formers. Our in vitro analytical measurements demonstrate even a possibility to dissolve CaOX stones in human urine, in which increased concentration of HA have been established. A conclusion can be that drowning out HA is a significant regulator of CaOX supersaturation and thus a regulation of CaOX stone formation in human urine. Discussions have arisen to use increased concentration of HA in urine both as a solubilizator of CaOX stones in the urinary tract and on the purpose of a prolonged metaphylactic treatment. PMID:24307993

Atanassova, Stoyanka S.; Gutzow, Ivan S.

2013-01-01

121

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

122

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

PubMed

Phencyclidine (PCP) is a noncompetitive, open channel blocker of the N-methyl-D-aspartate (NMDA) receptor-ion channel complex. When administered to immature animals, it is known to cause apoptotic neurodegeneration in several regions, and this is followed by olanzapine-sensitive, schizophrenia-like behaviors in late adolescence and adulthood. Clarification of its mechanism of action could yield data that would help to inform the treatment of schizophrenia. In our initial experiments, we found that ?-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) inhibited PCP-induced apoptosis in organotypic neonatal rat brain slices in a concentration-dependent and 6-cyano-7-nitroquinoxaline-2,3-dione-sensitive manner. Calcium signaling pathways are widely implicated in apoptosis, and PCP prevents calcium influx through NMDA receptor channels. We therefore hypothesized that AMPA could protect against this effect by activation of voltage-dependent calcium channels (VDCCs). In support of this hypothesis, pretreatment with the calcium channel blocker cadmium chloride eliminated AMPA-mediated protection against PCP. Furthermore, the L-type VDCC inhibitor nifedipine (10 µM) fully abrogated the effects of AMPA, suggesting that L-type VDCCs are required for AMPA-mediated protection against PCP-induced neurotoxicity. Whereas the P/Q-type inhibitor ?-agatoxin TK (200 nM) reduced AMPA protection by 51.7%, the N-type VDCC inhibitor ?-conotoxin (2 µM) had no effect. Decreased AMPA-mediated protection following cotreatment with K252a, a TrkB inhibitor, suggests that brain-derived neurotrophic factor signaling plays an important role. By analogy, these results suggest that activation of L-type, and to a lesser extent P/Q-type, VDCCs might be advantageous in treating conditions associated with diminished NMDAergic activity during early development. © 2014 Wiley Periodicals, Inc. PMID:24995437

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

2014-12-01

123

Secondary prevention after myocardial infarction: Effects of beta blocking agents and calcium antagonists  

Microsoft Academic Search

Therapeutic interventions in patients with myocardial infarction, whether during the first hours after coronary occlusion or several days later, aim to reduce mortality and morbidity by several mechanisms: Prevention of fatal ventricular fibrillation, limitation of infarct size, and inhibition of platelet aggregation are some examples of such mechanisms. Results from early intervention trials with beta blocking agents, particularly from ISIS-I,

P. Depelchin; J. Sobolski; M. Jottrand; C. Flament

1988-01-01

124

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

Microsoft Academic Search

Leaf-sheath pulvini of excised segments from oat (Avena sativa L.) were induced to grow by treatment with 10 ?M indole-3-acetic acid (IAA), gravistimulation, or both, and the effects of\\u000a 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

Thomas G. Brock; James Burg; Najati S. Ghosheh; Peter B. Kaufman

1992-01-01

125

Thermotolerance and antioxidant systems in Agrostis stolonifera: involvement of salicylic acid, abscisic acid, calcium, hydrogen peroxide, and ethylene.  

PubMed

This study investigated whether pre-treating plants with specific putative signaling components and heat acclimation would induce tolerance of a cool-season grass, creeping bentgrass (Agrostis stolonifera var. palustris), to subsequent heat stress and whether thermotolerance induction of those pretreatments was associated with the regulation of antioxidant regenerating enzymes. The treatments included foliar application of salicylic acid (SA), abscisic acid (ABA), calcium chloride (CaCl2), hydrogen peroxide (H2O2), 1-aminocyclopropane-1-carboxylic acid (ACC, a precursor of ethylene prior to the exposure of plants to heat stress (35 degrees C) in a growth chamber. Physiological measurements including turf quality, leaf photosynthetic rate, and levels of oxidative damage demonstrated that all treatments increased heat tolerance. The better heat tolerance for pre-treated plants as compared to controls was related to the protection of oxidative damage under heat stress. APX activity increased over the first 2 days and 5 days of heating for ACC and CaCl2 respectively, but for only 12 h for H2O2. SA and ABA pre-treatments had no effects on APX activity earlier, but maintained APX activity at a significantly higher level than in controls after 24 h of heating. SA and ABA pre-treatments had no effects on POX activity. ACC treatment significantly increased POX activity. Pre-treatment with CaCl2, H2O2, and HA reduced POX activity, particularly during the later phase of heating. Plants treated with SA, CaCl2, H2O2 and HA had lower CAT activity than their control plants prior to heating and within 48 h of heat stress. ABA and ACC pre-treatments maintained higher CAT activity than the controls after 48 h of heating. ACC, CaCl2, or HA pre-treatments increased SOD activity only before 5 days of heat stress. SA and ABA pre-treatments had less effect on APX activity earlier under heat stress. These results suggest that specific groups of potential signaling molecules may induce tolerance of creeping bentgrass to heat stress by reducing oxidative damage. PMID:15128028

Larkindale, Jane; Huang, Bingru

2004-04-01

126

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

PubMed

Transmembrane protein 16A (TMEM16A) channels are recently discovered membrane proteins that functions as a calcium activated chloride channel (CaCC). CaCCs are major regulators of various physiological processes, such as sensory transduction, epithelial secretion, smooth muscle contraction and oocyte fertilization. Thirty novel 5-substituted benzyloxy-2-arylbenzofuran-3-carboxylic acids (B01-B30) were synthesized and evaluated for their TMEM16A inhibitory activity by using short circuit current measurements in Fischer rat thyroid (FRT) cells expressing human TMEM16A. IC(50) values were calculated using YFP fluorescence plate reader assay. Final compounds, having free carboxylic group displayed significant inhibition. Eight of the novel compounds B02, B13, B21, B23, B25, B27, B28, B29 exhibit excellent CaCCs inhibition with IC(50) value <6 ?M, with compound B25 exhibiting the lowest IC(50) value of 2.8 ± 1.3 ?M. None of the tested ester analogs of final benzofuran derivatives displayed TMEM16A/CaCCs inhibition. PMID:22739085

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

2012-07-15

127

Two-dimensional multiwavelength fluorescence spectra of dipicolinic acid and calcium dipicolinate  

NASA Astrophysics Data System (ADS)

Dipicolinic acid (DPA) and the Ca2+ complex of DPA (CaDPA) are major chemical components of bacterial spores. With fluorescence being considered for the detection and identification of spores, it is important to understand the optical properties of the major components of the spores. We report in some detail on the room-temperature fluorescence excitation and emission spectra of DPA and its calcium ion complex and provide a comparison of the excitation-emission spectrum in a dry, wet paste and aqueous form. DPA solutions have weak, if any, fluorescence, with increased fluorescence when the DPA is dry. After exposure to a broad source UV light of the DPA, wet or dry, we observe a large increase in fluorescence with a maximum intensity emission peak at around 440 nm for excitation light with a wavelength of around 360 nm. There is a slight blueshift in the absorption spectra of UV-exposed DPA from the unexposed DPA solution. CaDPA in solution shows a slight fluorescence with increased fluorescence in the dry form, and a substantial increase of fluorescence was observed after UV exposure with an emission peak of around 410 nm for excitation around 305 nm. The detailed excitation-emission spectra are necessary for better interpretation of the fluorescence spectra of bacterial spores where DPA is a major chemical component.

Sarasanandarajah, Sivananthan; Kunnil, Joseph; Bronk, Burt V.; Reinisch, Lou

2005-03-01

128

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

129

Electrolytic deposition of calcium phosphate\\/chitosan coating on titanium alloy: Growth kinetics and influence of current density, acetic acid, and chitosan  

Microsoft Academic Search

Electrolytically deposited calcium phosphate\\/chitosan coating demonstrated good bone marrow stromal cell attachment. The aim of this study was to understand the coating's growth kinetics as well as the effects of current density, acetic acid, and chitosan on the coating's formation. The scanning electron micrographs found that calcium phosphate crystals homogeneously distributed into chitosan aggregates as early as 30 min. X-ray

Jiawei Wang; Apeldoorn van Aart; Groot de Klaas

2006-01-01

130

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

Cancer.gov

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

131

A new approach in biomimetic synthesis of calcium phosphate coatings using lactic acid–Na lactate buffered body fluid solution  

Microsoft Academic Search

The main objective of this study was to investigate calcium phosphate (CaP) coatings on Ti6Al4V substrates by using the biomimetic technique. To this purpose, a new solution was developed to coat CaP on Ti6Al4V alloy substrates. The newly formulated body fluid (Lac-SBF) contained appropriate amounts of sodium lactate (NaL) and lactic acid (HL), as well as all the other ionic

Ahmet Pasinli; Mithat Yuksel; Erdal Celik; Sevil Sener; A. Cuneyt Tas

2010-01-01

132

Preventive effect of chlorogenic acid on lens opacity and cytotoxicity in human lens epithelial cells.  

PubMed

The present study reveals the pharmacological effect of chlorogenic acid, a major phenolic compound in plants, food, and coffee, on diabetic cataracts. Chlorogenic acid examined the inhibitory effects upon rat lens aldose reductase (AR) activity and xylose-induced rat lens opacity. The effect of chlorogenic acid on high glucose-induced cytotoxicity in lens epithelial cells was also examined. Chlorogenic acid showed potential inhibitory activity against rat lens AR, with an IC?? value of 0.95 µM. The xylose-induced opacity of lenses was significantly improved after treatment with chlorogenic acid in a dose-dependent manner. Chlorogenic acid prevented high glucose-induced cytotoxicity in human lens epithelial (HLE-B3) cells in a dose-dependent manner. These results suggest that chlorogenic acid may provide a potential therapeutic approach for prevention of diabetic complications, such as cataracts. PMID:21628897

Kim, Young Sook; Kim, Nan Hee; Lee, Yun Mi; Kim, Jin Sook

2011-01-01

133

Iron prevents ascorbic acid (vitamin C) induced hydrogen peroxide accumulation in copper contaminated drinking water.  

PubMed

Ascorbic acid (vitamin C) induced hydrogen peroxide (H(2)O(2)) formation was measured in household drinking water and metal supplemented Milli-Q water by using the FOX assay. Here we show that ascorbic acid readily induces H(2)O(2) formation in Cu(II) supplemented Milli-Q water and poorly buffered household drinking water. In contrast to Cu(II), iron was not capable to support ascorbic acid induced H(2)O(2) formation during acidic conditions (pH: 3.5-5). In 12 out of the 48 drinking water samples incubated with 2 mM ascorbic acid, the H(2)O(2) concentration exceeded 400 microM. However, when trace amounts of Fe(III) (0.2 mg/l) was present during incubation, the ascorbic acid/Cu(II)-induced H(2)O(2) accumulation was totally blocked. Of the other common divalent or trivalent metal ions tested, that are normally present in drinking water (calcium, magnesium, zinc, cobalt, manganese or aluminum), only calcium and magnesium displayed a modest inhibitory activity on the ascorbic acid/Cu(II)-induced H(2)O(2) formation. Oxalic acid, one of the degradation products from ascorbic acid, was confirmed to actively participate in the iron induced degradation of H(2)O(2). Ascorbic acid/Cu(II)-induced H(2)O(2) formation during acidic conditions, as demonstrated here in poorly buffered drinking water, could be of importance in host defense against bacterial infections. In addition, our findings might explain the mechanism for the protective effect of iron against vitamin C induced cell toxicity. PMID:16298750

Jansson, Patric J; Lindqvist, Christer; Nordström, Tommy

2005-11-01

134

Inhibition of Stabilin-2 elevates circulating hyaluronic acid levels and prevents tumor metastasis  

E-print Network

Inhibition of Stabilin-2 elevates circulating hyaluronic acid levels and prevents tumor metastasis, and also suppressed spontaneous metastasis of mammary tumor and human breast tumor cells inoculated to lung endothelial cells. These results suggest that blocking Stab2 function prevents tumor metastasis

Gleeson, Joseph G.

135

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

SciTech Connect

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

Jones, R.L.; Carbonell, J.

1984-09-01

136

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

137

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

PubMed

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

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

2013-01-01

138

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

PubMed Central

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

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

2013-01-01

139

Vapour pressure of water over saturated solutions of tartaric acid, sodium hydrogen tartrate, sodium tartrate, potassium tartrate, calcium tartrate, barium tartrate, citric acid, disodium hydrogen citrate, sodium citrate, and potassium citrate at temperatures from 277 K to 317 K  

Microsoft Academic Search

Vapour pressures of saturated aqueous solutions of tartaric acid, sodium hydrogen tartrate, sodium tartrate, potassium tartrate, calcium tartrate, barium tartrate, citric acid, disodium hydrogen citrate, sodium citrate, and potassium citrate were determined in the temperature range (277 to 317)K using an electronic hygrometer. Only for tartaric acid, sodium tartrate, potassium tartrate and citric acid was it possible to compare the

Emanuel Manzurola; Alexander Apelblat

2003-01-01

140

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

Microsoft Academic Search

In areas impacted by acid precipitation, water chemistry of acidic ponds and streams often changes, resulting in increased mobilization of aluminum and decreased concentration of calcium carbonate. Aluminum binds with phosphorus and inhibits its uptake by organisms. Thus, invertebrate food organisms used by waterfowl may have inadequate Ca and P or elevated Al for normal growth and development. Acid rain

Donald W. Sparling

1990-01-01

141

An investigation into the role of calcium in the modulation of rat synaptosomal D-[3H]aspartate transport by docosahexaenoic acid.  

PubMed

The effect of the polyunsaturated fatty acid cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) on the high-affinity, sodium-dependent uptake of D-[3H]aspartate into purified rat brain synaptosomes was examined. Incubation of the synaptosomes with 20 microM DHA caused over 50% inhibition of the maximum velocity (V(max)) of D-[3H]aspartate transport. This inhibition was significantly potentiated by pre-exposure of the synaptosomes to the fatty acid for 10 min prior to the start of the transport assay. Less highly unsaturated fatty acids such as arachidonic acid (cis-5,8,11,14-eicosatetraenoic acid), linolenic acid (cis-9,12,15-octadecatrienoic acid) and oleic acid (cis-9-octadecenoic acid) were significantly less potent than DHA. Removal of extracellular calcium, or reduction of the intracellular calcium concentration using the intracellular calcium chelator BAPTA/AM (10 microM), did not reduce the inhibition caused by DHA. On the other hand, an increase in the concentration of intracellular calcium mediated by thapsigargin (25 microM) or the calcium ionophore A23187 (10 or 100 nM) led to a reduction in the rate of D-[3H]aspartate transport in the absence of DHA. The CaM kinase II inhibitor, KN-93, reduced D-[3H]aspartate uptake independently of whether DHA was also present, but had no effect on the inhibition of D-[3H]aspartate uptake by either A23187 or thapsigargin. We conclude that whereas DHA inhibits synaptosomal D-[3H]aspartate uptake in a calcium-independent manner, a calcium-based mechanism exists that can also modulate glutamate transporter activity. PMID:12729959

Berry, Colm B; McBean, Gethin J

2003-05-23

142

Calcium aluminate cements in fly ash\\/calcium aluminate blend phosphate cement systems: Their role in inhibiting carbonation and acid corrosion at a low hydrothermal temperature of 90°C  

Microsoft Academic Search

Study was focused upon formulating sodium polyphosphate-modified fly ash\\/calcium aluminate blend (SFCB) geothermal well cements with advanced anti-carbonation and anti-acid corrosive properties. At a low hydrothermal temperature of 90°C, to improve these properties, we investigated the effectiveness of various calcium aluminate cement (CAC) reactants in minimizing the rate of carbonation and in abating the attack of H2SO4 (pH ~ 1.6).

T. Sugama; L. E. Brothers; L. Weber

2002-01-01

143

Conjugated linoleic acid prevents the development of essential hypertension in spontaneously hypertensive rats  

Microsoft Academic Search

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of linoleic acid found in beef, lamb, and dairy products. CLA has attracted considerable attention over the past several decades because of its potentially beneficial biologic effects, including protective effects against several cancers, atherosclerosis, and obesity. In previous studies, we provided evidence that dietary CLA could prevent the

Nao Inoue; Koji Nagao; Junichi Hirata; Yu-Ming Wang; Teruyoshi Yanagita

2004-01-01

144

Inhibitory effects of phytic acid and other inositol phosphates on zinc and calcium absorption in suckling rats.  

PubMed

While it is known that phytic acid, inositol hexaphosphate, has a negative effect on zinc and calcium absorption, the effects of inositol which is phosphorylated to a lesser extent are less known. We have prepared inositol triphosphate (IP-3), tetraphosphate (IP-4), pentaphosphate (IP-5) and hexaphosphate (IP-6) by hydrolysis of sodium phytate and separation by ion-exchange chromatography and have studied their effect on zinc and calcium absorption. Using a suckling rat pup model, we found that liver uptake of 65Zn after 6 h was 5% of the total dose from solutions of IP-6, 19% from IP-5, 28% from IP-4, 29% from IP-3 and 31% from ZnCl2 (control). Non-absorbed calcium was 17%, 1.4%, 0.5%, 0.5% and 0.5% of the given dose of 45Ca, respectively. Thus, at a high degree of phosphorylation (IP-6, IP-5), zinc and calcium uptake was inhibited, while no effect was observed for the other phosphates. Consequently, total "phytate" analysis, which includes inositol phosphates with varying degrees of phosphorylation, can give misleading information with regard to mineral availability. In addition, even limited dephosphorylation of inositol hexaphosphate can have a positive effect on mineral absorption. PMID:2918393

Lönnerdal, B; Sandberg, A S; Sandström, B; Kunz, C

1989-02-01

145

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

146

The Use of Fibric Acid Derivatives in Cardiovascular Prevention  

Microsoft Academic Search

Opinion statement  Clinical trials have demonstrated the benefit of reduction of low-density lipoprotein (LDL) cholesterol levels in the prevention\\u000a of atherosclerotic cardiovascular disease. Evidence is less robust for the effect of reduction of triglyceride levels and\\u000a increase of high-density lipoprotein (HDL) cholesterol levels. In spite of the decrease of cardiovascular events in trials\\u000a of LDL cholesterol–lowering medications, considerable residual risk remains,

Nadia Khoury; Anne Carol Goldberg

147

Bioactive 1,4-dihydroisonicotinic acid derivatives prevent oxidative damage of liver cells  

Microsoft Academic Search

1,4-Dihydroisonicotinic acid derivatives (1,4-DHINA) are compounds closely related to derivatives of 1,4-dihydropyridine, a well-known calcium channel antagonists. 1,4-DHINA we used were derived from a well-known antioxidant Diludin. Although some compounds have neuromodulatory or antimutagenic properties, their activity mechanisms are not well known. This study was performed to obtain data on antioxidant and bioprotective activities of: 2,6-dimethyl-3,5-diethoxycarbonyl-1,4-dihydroisonicotinic acid (Ia); sodium 2-(2,6-dimethyl-3,5-diethoxycarbonyl-1,4-dihydropyridine-4-carboxamido)glutamate

Suzana Borovic; Gunars Tirzitis; Dace Tirzite; Ana Cipak; Gholam A. Khoschsorur; Georg Waeg; Franz Tatzber; Mira Scukanec-Spoljar; Neven Zarkovic

2006-01-01

148

Inhibition of hydroxyapatite dissolution by ovalbumin as a function of pH, calcium concentration, protein concentration and acid type.  

PubMed

Hydroxyapatite is the main constituent of the dental hard tissues, and in vivo its dissolution in acids leads to the pathological condition of dental erosion. Food proteins which inhibit hydroxyapatite dissolution may find application as erosion-reducing agents in food and drink products. The aim of this study was to investigate the egg protein ovalbumin as a potential inhibitor of hydroxyapatite dissolution in acidic solutions, with conditions representative of dental erosion. The dissolution rate of hydroxyapatite discs was measured in an acidic solution as a function of pH, calcium concentration, ovalbumin concentration and acid type. All experiments were performed in triplicate. 0.2% w/v ovalbumin significantly reduced the dissolution rate in citric acid by 50-75% over the pH range 2.80-4.00, and by 45-60% in solutions with calcium concentrations of up to 20 mM (p < 0.05). The effect was persistent for several rinses after the initial exposure to the protein. 0.02% w/v ovalbumin significantly reduced the dissolution of hydroxyapatite in citric acid by 30-55%. Ovalbumin did not, however, statistically significantly reduce the hydroxyapatite dissolution rate in malic or lactic acids. The effect is ascribed to adsorption and partial, reversible denaturation of ovalbumin on the hydroxyapatite surface. There may be some interaction between ovalbumin and the citrate ion which promotes the adsorption of protein in the presence of citric acid. Ovalbumin shows promise as a potential erosion-reducing additive to citrus-based drinks. PMID:18714157

Hemingway, C A; Shellis, R P; Parker, D M; Addy, M; Barbour, M E

2008-01-01

149

Omega-3 Fatty Acids Unlikely to Prevent Cancer  

Cancer.gov

An analysis of numerous, large population cohort studies did not detect evidence of a significant link between dietary intake of omega-3 fatty acids (found in fish) and the incidence of several major cancer types, according to a review study published in the January 25, 2006, issue of the Journal of the American Medical Association.

150

Role of calcium independent phospholipase A2 in maintaining mitochondrial membrane potential and preventing excessive exocytosis in PC12 cells.  

PubMed

This study was carried out to elucidate the effects of calcium independent phospholipase A(2) (iPLA(2)) on mitochondrial function and exocytosis in neuroendocrine cells. iPLA(2) mRNA and protein were detected in cell lysates and mitochondria from PC12 cells. Treatment of cells with the iPLA(2) inhibitor, bromoenol lactone (BEL), resulted in reduction in the mitochondrial membrane potential. Increase in membrane capacitance and number of spikes at amperometry, indicating exocytosis, were detected from PC12 cells after treatment with BEL. The induced exocytosis was abolished by pre-incubation of cells with the antioxidant, glutathione monoethyl ester, spin-trap/free radical scavenger, PBN, or inhibitors of the mitochondrial permeability transition pore, cyclosporine A and bongkrekic acid. These findings indicate that inhibition of iPLA(2) results in excessive exocytosis through increased oxidative damage (or failure to repair such damage) and defects in mitochondrial function. A similar process may occur in neurons with mutations in iPLA(2), leading to neuronal injury. PMID:21116712

Ma, May-Thu; Yeo, Jin-Fei; Farooqui, Akhlaq A; Ong, Wei-Yi

2011-02-01

151

Recovery of calcium carbonate from waste gypsum and utilization for remediation of acid mine drainage from coal mines.  

PubMed

The recovery of calcium carbonate from waste gypsum (a waste product of the reverse osmosis (RO) desalination process) was tested using sodium carbonate. Batch recovery of calcium carbonate from waste gypsum slurries by reacting with sodium carbonate under ambient conditions was used to assess the technical feasibility of CaCO(3) recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effect of key process parameters, such as the slurry concentration (%) and the molar ratio of sodium carbonate to gypsum were considered. It was observed that batch waste gypsum conversion significantly increased with decrease in the slurry concentration or increase in the molar ratio of sodium carbonate to gypsum. The CaCO(3) recovered from the bench-scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with commercial laboratory grade CaCO(3). PMID:22828309

Mulopo, J; Radebe, V

2012-01-01

152

The role of citric acid in oral peptide and protein formulations: relationship between calcium chelation and proteolysis inhibition.  

PubMed

The excipient citric acid (CA) has been reported to improve oral absorption of peptides by different mechanisms. The balance between its related properties of calcium chelation and permeation enhancement compared to a proteolysis inhibition was examined. A predictive model of CA's calcium chelation activity was developed and verified experimentally using an ion-selective electrode. The effects of CA, its salt (citrate, Cit) and the established permeation enhancer, lauroyl carnitine chloride (LCC) were compared by measuring transepithelial electrical resistance (TEER) and permeability of insulin and FD4 across Caco-2 monolayers and rat small intestinal mucosae mounted in Ussing chambers. Proteolytic degradation of insulin was determined in rat luminal extracts across a range of pH values in the presence of CA. CA's capacity to chelate calcium decreased ~10-fold for each pH unit moving from pH 6 to pH 3. CA was an inferior weak permeation enhancer compared to LCC in both in vitro models using physiological buffers. At pH 4.5 however, degradation of insulin in rat luminal extracts was significantly inhibited in the presence of 10mM CA. The capacity of CA to chelate luminal calcium does not occur significantly at the acidic pH values where it effectively inhibits proteolysis, which is its dominant action in oral peptide formulations. On account of insulin's low basal permeability, inclusion of alternative permeation enhancers is likely to be necessary to achieve sufficient oral bioavailability since this is a weak property of CA. PMID:24384069

Welling, Søren H; Hubálek, František; Jacobsen, Jette; Brayden, David J; Rahbek, Ulrik L; Buckley, Stephen T

2014-04-01

153

FISH OIL PREVENTS ESSENTIAL FATTY ACID DEFICIENCY AND ENHANCES GROWTH: CLINICAL AND BIOCHEMICAL IMPLICATIONS  

PubMed Central

Background Fish oil, a rich source of omega-3 fatty acids, has never been used as the sole source of lipid in clinical practice for fear of development of essential fatty acid deficiency, as it lacks the believed requisite levels of linoleic acid, an omega-6 fatty acid. The objectives of this study were to establish biochemical standards for fish oil as the sole fat and to test the hypothesis that fish oil contains adequate amounts of omega-6 fatty acids to prevent essential fatty acid deficiency. Methods Forty mice were divided into two groups that were either pair fed or allowed to eat ad libitum. In each group, four subgroups of five mice were fed 1%, 5%, and 10% fish oil diets by weight or a control soybean diet for nine weeks. Blood was collected at four time points and fatty acid analysis was performed. Food intake and weight status were monitored. Results All groups but the pair fed 1% fish oil group gained weight and the 5% fish oil group showed the highest caloric efficiency in both pair fed and ad libitum groups. Fatty acid profiles for the 1% fish oil group displayed clear essential fatty acid deficiency, 5% fish oil appeared marginal, and 10% and soybean oil diets were found to prevent essential fatty acid deficiency. Conclusion Fish oil enhances growth through higher caloric efficiency. We established a total omega-6 fatty acid requirement of between 0.30% and 0.56% of dietary energy, approximately half of the conventionally believed 1% as linoleic acid. This can presumably be attributed to the fact that fish oil contains not only a small amount of linoleic acid, but also arachidonic acid, which has greater efficiency to meet omega-6 fatty acid requirements. PMID:18442636

Strijbosch, RAM; Lee, S; Arsenault, DA; Andersson, C; Gura, KM; Bistrian, BR; Puder, M

2012-01-01

154

Complete amino acid sequence of the sarcoplasmic calcium-binding protein (SCP-I) from crayfish (Astacus leptodactylus).  

PubMed

The complete amino acid sequence of the alpha chain of the dimeric sarcoplasmic Ca2+-binding protein (SCP-I = alpha 2) from crayfish (Astacus leptodactylus) has been determined by partial automatic sequencing of the peptides derived from tryptic digests of the protein after citraconylation or treatment with 1,2-cyclohexanedione. Overlapping peptides were obtained by cleavage with o-iodosobenzoic acid, or digestion with Staphylococcus aureus protease, thermolysin and pepsin. The acetylated N-terminus was identified by fast atom bombardment mass spectrometry. The monomeric protein contains 192 amino acids and has an Mr of 21,643. The sequence shows the presence of three calcium-binding sites and perhaps of two others that may be degenerated. PMID:2917647

Jauregui-Adell, J; Wnuk, W; Cox, J A

1989-01-30

155

ISOLATION OF PECTIC ACIDS FROM BLEACHED TMP WATER AND AGGREGATION OF MODEL AND TMP PECTIC ACIDS BY CALCIUM  

Microsoft Academic Search

Pectins are important structural elements in spruce fibres. Alkaline peroxide bleaching of spruce thermomechanical pulp (TMP) causes degradation and demethylation of pectins, yielding high-charge-density pectic acids. The pectic acids in fibres contribute strongly to the negative fibre charge, and the dissolved pectic acids increase the cationic demand of bleached TMP water. In this study, a method to isolate pectic acids

Ville J. Saarimaa; Andrey V. Pranovich; Anna C. Sundberg; Bjarne R. Holmbom

156

Preventing Intra-Abdominal Adhesions With Polylactic Acid Film: An Animal Study  

Microsoft Academic Search

PURPOSE  The aim of this study was to evaluate the efficacy of an absorbable polylactic acid film (SurgiWrapTM) in preventing postoperative intra-abdominal adhesions in an animal model.METHODS  Forty-four female Sprague-Dawley rats underwent laparotomy with subsequent cecal wall abrasion and abdominal wall injury. Rats were divided equally between untreated and treated groups. Treated rats had a polylactic acid film (SurgiWrapTM) placed between the

Shmuel Avital; Thomas J. Bollinger; James D. Wilkinson; Floriano Marchetti; Michael D. Hellinger; Laurence R. Sands

2005-01-01

157

Incremental effect of a calcium salt of cis-monounsaturated fatty acids supplement on milk fatty acid composition in cows fed maize silage-based diets.  

PubMed

In most Western countries, saturated fatty acid (SFA) intake exceeds recommended levels, which is considered a risk factor for cardiovascular disease (CVD). As milk and dairy products are major contributors to SFA intake in many countries, recent research has focused on sustainable methods of producing milk with a lower saturated fat concentration by altering dairy cow diets. Human intervention studies have shown that CVD risk can be reduced by consuming dairy products with reduced SFA and increased cis-monounsaturated fatty acid (MUFA) concentrations. This milk fatty acid profile can be achieved by supplementing dairy cow diets with cis-MUFA-rich unsaturated oils. However, rumen exposure of unsaturated oils also leads to enhanced milk trans fatty acid (TFA) concentrations. Because of concerns about the effects of TFA consumption on CVD, feeding strategies that increase MUFA concentrations in milk without concomitant increases in TFA concentration are preferred by milk processors. In an attempt to limit TFA production and increase the replacement of SFA by cis-MUFA, a preparation of rumen-protected unsaturated oils was developed using saponification with calcium salts. Four multiparous Holstein-Friesian cows in mid-late lactation were used in a 4 × 4 Latin square design with 21-d periods to investigate the effect of incremental dietary inclusion of a calcium salt of cis-MUFA product (Ca-MUFA; 20, 40, and 60 g/kg of dry matter of a maize silage-based diet), on milk production, composition, and fatty acid concentration. Increasing Ca-MUFA inclusion reduced dry matter intake linearly, but no change was observed in estimated ME intake. No change in milk yield was noted, but milk fat and protein concentrations were linearly reduced. Supplementation with Ca-MUFA resulted in a linear reduction in total SFA (from 71 to 52 g/100 g of fatty acids for control and 60 g/kg of dry matter diets, respectively). In addition, concentrations of both cis- and trans-MUFA were increased with Ca-MUFA inclusion, and increases in other biohydrogenation intermediates in milk fat were also observed. The Ca-MUFA supplement was very effective at reducing milk SFA concentration and increasing cis-MUFA concentrations without incurring any negative effects on milk and milk component yields. However, reduced milk fat and protein concentrations, together with increases in milk TFA concentrations, suggest partial dissociation of the calcium salts in the rumen. PMID:23498010

Kliem, K E; Reynolds, C K; Humphries, D J; Kirkland, R M; Barratt, C E S; Livingstone, K M; Givens, D I

2013-05-01

158

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

PubMed

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

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

2010-02-01

159

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

PubMed

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

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

2014-09-01

160

Corticosteroid Pretreatment Prevents Small Intestinal Mucosal Lesion Induced by Acetic Acid-Perfusion Model in Rats  

Microsoft Academic Search

One of the important problems in experimentally induced small intestinal lesions is that there is no reproducible model of diffuse and stable mucosal lesion. In this paper, we studied in detail the effects of continuous perfusion of various concentrations of acetic acid on the rat small intestinal mucosa. In order to evaluate its applicability for screening of the preventive effect

Ivan Pacheco; Michiro Otaka; Mario Jin; Hideaki Sasahara; Akira Iwabuchi; Masaru Odashima; Noriaki Konishi; Isao Wada; Osamu Masamune; Sumio Watanabe

2000-01-01

161

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

Microsoft Academic Search

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

Johanna Nyquist; Maria Greger

2009-01-01

162

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

163

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

PubMed Central

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

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

2014-01-01

164

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

E-print Network

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

Terk, Michael

2007-01-01

165

Calcium carbonate crystal growth beneath Langmuir monolayers of acidic ?-hairpin peptides.  

PubMed

Four amphiphilic peptides with designed hairpin structure were synthesized and their monolayers were employed as model systems to study biologically inspired calcium carbonate crystallization. Langmuir monolayers of hairpin peptides were investigated by surface pressure area isotherms, surface potential isotherms, Brewster angle microscopy (BAM), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. A ?-hairpin conformation was found for all peptides at the air-water interface although their packing arrangements seem to be different. Crystallization of calcium carbonate under these peptide monolayers was investigated at different surface pressures and growth times both by in situ optical microscopy, BAM and ex situ investigations such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). An amorphous calcium carbonate precursor was found at the initial crystallization stage. The crystallization process occurred in three stages. It starts from the nucleation of amorphous particles being a kinetically controlled process. Crystal nuclei subsequently aggregate to large particles and vaterite crystals start to form inside the amorphous layer, with the monolayer fluidity exerting an important role. The third process includes the re-crystallization of vaterite to calcite, which is thermodynamically controlled by monolayer structural factors including the monolayer flexibility and packing arrangement of the polar headgroups. Thus, the kinetic factors, monolayer fluidity and flexibility as well as structure factors govern the crystal morphology and polymorph distribution simultaneously and synergistically. PMID:25292256

Gong, Haofei; Yang, Yi; Pluntke, Manuela; Marti, Othmar; Majer, Zsuzsa; Sewald, Norbert; Volkmer, Dirk

2014-10-22

166

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

PubMed Central

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

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

2012-01-01

167

Prevention of aflatoxicosis in farm animals by Means of hydrated sodium calcium aluminosilicate addition to feedstuffs: a review  

Microsoft Academic Search

Mycotoxins are a wide group of fungal toxins that have been associated with severe toxic effects in man and animals. Aflatoxins are the most dangerous of these fungal secondary metabolites. Because there is no definitive way in which complete detoxification of food and feed contaminated with mycotoxins can be achieved, new methods to eliminate mycotoxicosis are sought.Hydrated sodium calcium aluminosilicate

A. J. Ramos; E. Hernández

1997-01-01

168

Effect of calcium on synthesis of dipicolinic acid in Penicillium citreoviride and its feedback resistant mutant  

Microsoft Academic Search

Dipicolinic acid synthesis inPenicillium citreoviride strain 3114 was inhibited by Ca2+ ions, but not by Ba2+, Cu2+or Fe2+. Among the metals tested, only Zn2+ inhibited the synthesis of dipicolinic acid and promoted sporulation. None of these metals reversed the inhibition by Ca2+ or Zn2+. A mutant 27133-dpa-ca selected for resistance to feedback inhibition by dipicolinic acid: Ca2+ complex showed cross-resistance

G. P. Kalle; Y. M. Deo

1983-01-01

169

Ursodeoxycholic Acid in the Prevention of Gallstone Formation after Bariatric Surgery: A Meta-analysis  

Microsoft Academic Search

Background  Rapid weight loss increases risk for gallstone formation. Prophylactic cholecystectomy is difficult. Several small trials\\u000a have shown that ursodeoxycholic acid (UDCA) may prevent gallstone formation after bariatric surgery. The aim of this study\\u000a is to assess the efficacy and safety of UDCA in the prevention of gallstone formation after bariatric surgery.\\u000a \\u000a \\u000a \\u000a Methods  Electronic databases, including the Cochrane Central Register of Controlled

Manley C. Uy; Marilyn C. Talingdan-Te; Wendell Z. Espinosa; Ma. Lourdes O. Daez; Janus P. Ong

2008-01-01

170

Calcium sulfate crystallization along citrus root channels in a Florida soil exhibiting acid sulfate properties  

SciTech Connect

The authors observed euhedral crystals in Manatee soil in a citrus grove in St. Lucie County, Florida. The material was identified as gypsum (CaSO/sub 4/ /times/ 2H/sub 2/O) using x-ray diffraction and infrared spectra. Photomicrography and scanning electron microscopy revealed that gypsum accumulated both in old root channels and within citrus root tissue of the Btg horizon. The subsurface horizons had elevated sulfate levels, a low initial pH, a drop (0.5 unit) in pH upon air-drying. Electrical conductivity paralleled the concentration of water-soluble sulfate. High levels of calcium and sulfate occurred for horizons above the water table. This accumulation is attributed to groundwater bearing these ions and subsequently discharging them to the overlying soil. Dead citrus roots appear to act as wicks to aid water transfer from lower to higher horizons. The roots and their empty channels provide spaces in which the gypsum can precipitate if the concentrations of calcium and sulfate in the evaporating groundwater exceed the solubility product of gypsum.

Syslo, S.K.; Myhre, D.L.; Harris, W.G.

1988-02-01

171

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

172

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

173

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 Idioblasts1  

PubMed Central

l-Ascorbic acid (AsA) and its metabolic precursors give rise to oxalic acid (OxA) found in calcium oxalate crystals in specialized crystal idioblast cells in plants; however, it is not known if AsA and OxA are synthesized within the crystal idioblast cell or transported in from surrounding mesophyll cells. Isolated developing crystal idioblasts from Pistia stratiotes were used to study the pathway of OxA biosynthesis and to determine if idioblasts contain the entire path and are essentially independent in OxA synthesis. Idioblasts were supplied with various 14C-labeled compounds and examined by micro-autoradiography for incorporation of 14C into calcium oxalate crystals. [14C]OxA gave heavy labeling of crystals, indicating the isolated idioblasts are functional in crystal formation. Incubation with [1-14C]AsA also gave heavy labeling of crystals, whereas [6-14C]AsA gave no labeling. Labeled precursors of AsA (l-[1-14C]galactose; d-[1-14C]mannose) also resulted in crystal labeling, as did the ascorbic acid analog, d-[1-14C]erythorbic acid. Intensity of labeling of isolated idioblasts followed 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 results are discussed with respect to fine control of calcium oxalate precipitation and the concept of crystal idioblasts as independent physiological compartments. PMID:11161021

Kostman, Todd A.; Tarlyn, Nathan M.; Loewus, Frank A.; Franceschi, Vincent R.

2001-01-01

174

Intracellular calcium regulates insulin-like growth factor-I messenger ribonucleic acid levels.  

PubMed

Insulin-like growth factor-I (IGF-I) is involved in repair and regeneration in tissues in which non-GH-mediated regulation of its production has been shown to be important. We have investigated the effects of a second messenger signaling pathway, intracellular calcium, on IGF-I mRNA levels in cultured rat dermal fibroblasts using a RNase protection assay. Intracellular calcium concentrations ([Ca2+]i) were increased using either the calcium ionophore A23187 or thapsigargin. The ability of these agents to increase [Ca2+]i was confirmed by spectrofluorimetry, using fluo-3 as the Ca2+ indicator. Treatment of cells in serum-free medium and 0.25% BSA [Minimum Essential Medium (MEM) + BSA] with 500 nM A23187 or 1 micron thapsigargin decreased IGF-I mRNA levels in a time-responsive manner over 4-8 h. A23187 and thapsigargin also decreased IGF-I mRNA levels to 36% and 47% of control levels, respectively, in a dose-responsive fashion. Basic fibroblast growth factor mRNA levels, which were simultaneously determined, were either unchanged or increased in cells treated with thapsigargin or A23187. Consistent with the change in IGF-I mRNA levels, immunoreactive IGF-I levels in medium conditioned for 48 h by A23187 or thapsigargin decreased to 25% and 14%, respectively, of control levels in cells maintained in MEM + BSA. To determine the role of protein synthesis in the effects of A23187 and thapsigargin, cells were treated with these agents in the presence or absence of cycloheximide. Cycloheximide had no effect on the decrease in IGF-I mRNA levels mediated by thapsigargin, but significantly attenuated the response to A23187. Given these differences in the role of protein synthesis in and the time course of the effects of A23187 and thapsigargin on IGF-I mRNA levels, additivity experiments were performed. Treatment of cells with the combination of A23187 and thapsigargin resulted in IGF-I mRNA levels that were approximately 70% of the levels present in cells treated with either agent alone. These data are consistent with a small additive effect, but suggest that the majority of the effect of A23187 and thapsigargin occurs via the same final pathway.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8477645

Hovis, J G; Meyer, T; Teasdale, R M; Albrecht, B N; Yorek, M A; Lowe, W L

1993-05-01

175

Evaluation of four animal models of intrarenal calcium deposition and assessment of the influence of dietary supplementation with essential fatty acids on calcification  

Microsoft Academic Search

Firstly, to determine a satisfactory animal model for induction of intrarenal calcification, a study of four previously described animal models of intrarenal calcification was carried out which showed that intraperitoneal injection of 10% calcium gluconate into female Sprague-Dawley rats was most effective. We then investigated the hypothesis that dietary supplementation with essential fatty acids could reduce the intrarenal calcification developing

N. A. Burgess; T. M. Reynolds; N. Williams; A. Pathy; S. Smith

1995-01-01

176

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

177

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

Microsoft Academic Search

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

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

2011-01-01

178

BCL2/BCL-X(L) inhibition induces apoptosis, disrupts cellular calcium homeostasis, and prevents platelet activation.  

PubMed

Apoptosis in megakaryocytes results in the formation of platelets. The role of apoptotic pathways in platelet turnover and in the apoptotic-like changes seen after platelet activation is poorly understood. ABT-263 (Navitoclax), a specific inhibitor of antiapoptotic BCL2 proteins, which is currently being evaluated in clinical trials for the treatment of leukemia and other malignancies, induces a dose-limiting thrombocytopenia. In this study, the relationship between BCL2/BCL-X(L) inhibition, apoptosis, and platelet activation was investigated. Exposure to ABT-263 induced apoptosis but repressed platelet activation by physiologic agonists. Notably, ABT-263 induced an immediate calcium response in platelets and the depletion of intracellular calcium stores, indicating that on BCL2/BCL-X(L) inhibition platelet activation is abrogated because of a diminished calcium signaling. By comparing the effects of ABT-263 and its analog ABT-737 on platelets and leukemia cells from the same donor, we show, for the first time, that these BCL2/BCL-X(L) inhibitors do not offer any selective toxicity but induce apoptosis at similar concentrations in leukemia cells and platelets. However, reticulated platelets are less sensitive to apoptosis, supporting the hypothesis that treatment with ABT-263 induces a selective loss of older platelets and providing an explanation for the transient thrombocytopenia observed on ABT-263 treatment. PMID:21562047

Vogler, Meike; Hamali, Hassan A; Sun, Xiao-Ming; Bampton, Edward T W; Dinsdale, David; Snowden, Roger T; Dyer, Martin J S; Goodall, Alison H; Cohen, Gerald M

2011-06-30

179

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. PMID:25028592

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

180

Effect of pH and succinic acid on the morphology of ?-calcium sulfate hemihydrate synthesized by a salt solution method  

NASA Astrophysics Data System (ADS)

Well-crystallized ?-calcium sulfate hemihydrate (?-CSH) powders useful for bone defect filling were synthesized using a salt solution method and their morphologies were effectively modified by adjusting the pH of the reaction solutions or by adding succinic acid. The effect and its mechanism of the pH and the succinic acid on the phase composition and the morphology of the crystals were discussed in detail.

Li, Fan; Liu, Jianli; Yang, Guangyong; Pan, Zongyou; Ni, Xiao; Xu, Huazi; Huang, Qing

2013-07-01

181

Therapeutical targeting of nucleic acid-sensing Toll-like receptors prevents experimental cerebral malaria  

PubMed Central

Excessive release of proinflammatory cytokines by innate immune cells is an important component of the pathogenic basis of malaria. Proinflammatory cytokines are a direct output of Toll-like receptor (TLR) activation during microbial infection. Thus, interference with TLR function is likely to render a better clinical outcome by preventing their aberrant activation and the excessive release of inflammatory mediators. Herein, we describe the protective effect and mechanism of action of E6446, a synthetic antagonist of nucleic acid-sensing TLRs, on experimental cerebral malaria (ECM) induced by Plasmodium berghei ANKA. We show that in vitro, low doses of E6446 specifically inhibited the activation of human and mouse TLR9. Tenfold higher concentrations of this compound also inhibited the human TLR8 response to single-stranded RNA. In vivo, therapy with E6446 diminished the activation of TLR9 and prevented the exacerbated cytokine response observed during acute Plasmodium infection. Furthermore, severe signs of ECM, such as limb paralysis, brain vascular leak, and death, were all prevented by oral treatment with E6446. Hence, we provide evidence that supports the involvement of nucleic acid-sensing TLRs in malaria pathogenesis and that interference with the activation of these receptors is a promising strategy to prevent deleterious inflammatory responses that mediate pathogenesis and severity of malaria. PMID:21303985

Franklin, Bernardo S.; Ishizaka, Sally T.; Lamphier, Marc; Gusovsky, Fabian; Hansen, Hans; Rose, Jeffrey; Zheng, Wanjun; Ataide, Marco Antonio; de Oliveira, Rosane B.; Golenbock, Douglas T.; Gazzinelli, Ricardo T.

2011-01-01

182

n-3 Fatty Acids Modulate T-Cell Calcium Signaling in Obese Macrosomic Rats  

Microsoft Academic Search

Objective: We investigated the effects of a diet containing EPAX-7010, rich in PUFAs such as eicosapentaenoic acid [20:5(n-3)] and docosahexaenoic acid [22:6(n-3)], i.e., a PUFA\\/EPAX regimen, on T-cell activation in diabetic pregnant rats and their obese pups.Research Methods and Procedures: Mild hyperglycemia in pregnant rats was induced by intraperitoneal injection of streptozotocin on Day 5 of gestation. T-cell blastogenesis was

Baya Guermouche; Akadiri Yessoufou; Nassima Soulimane; Hafida Merzouk; Kabirou Moutairou; Aziz Hichami; Naim Akhtar Khan

2004-01-01

183

Acidic mist reduces foliar membrane-associated calcium and impairs stomatal responsiveness in red spruce  

Microsoft Academic Search

Summary Acidic deposition can leach essential pools of cal- cium (Ca) directly from plant foliage. Because of the central role of Ca in environmental signal transduction, disruptions of labile foliar Ca pools could impair physiological responses to a variety of environmental stimuli and stressors. We investigated the possibility that acidic mist-induced depletion of mem- brane-associated Ca (mCa), which is one

CATHERINE H. BORER; PAUL G. SCHABERG; DONALD H. DEHAYES

184

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. PMID:20621767

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

185

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

186

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

PubMed Central

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

Mirhadi, Hossein; Moazzami, Fariborz; Safarzade, Sareh

2014-01-01

187

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

PubMed Central

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

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

2014-01-01

188

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2012 CFR

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2012-04-01

189

21 CFR 184.1201 - Calcium glycerophosphate.  

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2014-04-01

190

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2011 CFR

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2011-04-01

191

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2013 CFR

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2013-04-01

192

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2010 CFR

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2010-04-01

193

21 CFR 172.720 - Calcium lactobionate.  

Code of Federal Regulations, 2011 CFR

...Calcium lactobionate. The food additive calcium lactobionate may be safely used in food in accordance with the following...conditions: (a) The food additive is the calcium...D-gluconic acid) produced by the oxidation of lactose. (b)...

2011-04-01

194

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

195

Inhibition of Calcium Oxalate Crystal Growth in vitro by Uropontin: Another Member of the Aspartic Acid-Rich Protein Superfamily  

Microsoft Academic Search

The majority of human urinary stones are primarily composed of calcium salts. Although normal urine is frequently supersaturated with respect to calcium oxalate, most humans do not form stones. Inhibitors are among the multiple factors that may influence the complex process of urinary stone formation. We have isolated an inhibitor of calcium oxalate crystal growth from human urine by monoclonal

H. Shiraga; W. Min; W. J. Vandusen; M. D. Clayman; D. Miner; C. H. Terrell; J. R. Sherbotie; J. W. Foreman; C. Przysiecki; E. G. Neilson; J. R. Hoyer

1992-01-01

196

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

PubMed Central

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

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

2008-01-01

197

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

NASA Technical Reports Server (NTRS)

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

Cacioppo, Elizabeth; Pusey, Marc L.

1992-01-01

198

Electrolytic deposition of calcium phosphate/chitosan coating on titanium alloy: growth kinetics and influence of current density, acetic acid, and chitosan.  

PubMed

Electrolytically deposited calcium phosphate/chitosan coating demonstrated good bone marrow stromal cell attachment. The aim of this study was to understand the coating's growth kinetics as well as the effects of current density, acetic acid, and chitosan on the coating's formation. The scanning electron micrographs found that calcium phosphate crystals homogeneously distributed into chitosan aggregates as early as 30 min. X-ray diffraction patterns and Fourier transform infrared spectra demonstrated that the coating experienced a compositional conversion from octacalcium phosphate to carbonate apatite during the deposition process. Electric current influenced the deposition. Higher current density accelerated the process and induced faster and more chitosan deposition. Both acetic acid and chitosan were found to inhibit calcium phosphate deposition. Chitosan was thought to induce stronger effects than acetic acid did. Furthermore, the inhibitive effect related to their concentration in the electrolyte. When chitosan concentration increased to a certain degree, this inhibitive effect not only affected calcium phosphate deposition, but also affected its own deposition. The chitosan content within the hybrid coating was small, which could be verified through Raman spectrum. At the same time, no clear evidence of chemical reactions could be found between these two components. We considered that both components were just naturally wrapped to form as a whole. PMID:16278873

Wang, Jiawei; van Apeldoorn, Aart; de Groot, Klaas

2006-03-01

199

An evaluation of waste gypsum-based precipitated calcium carbonate for acid mine drainage neutralization.  

PubMed

Precipitated CaCO(3) compounds recovered from pulped waste gypsum using some carbonate and hydroxide-based reagents were evaluated for their utilization in acid mine drainage (AMD) neutralization. The neutralization potentials, acid neutralization capacities and compositions of the CaCO(3) compounds were determined and compared with some commercial CaCO(3). It was observed that CaCO(3) recovered from waste gypsum using Na(2)CO(3) significantly neutralized AMD compared with commercial CaCO(3) and that recovered using both (NH(4))(2)CO(3) or NH(4)OH-CO(2) reagents. Moreover, a higher acid neutralization capacity of 1,370 kg H(2)SO(4)/t was determined for CaCO(3) recovered from waste gypsum using Na(2)CO(3) compared with an average of 721 and 1,081 kg H(2)SO(4)/t for ammonium-based CaCO(3) and commercial CaCO(3) respectively. The inorganic carbon content for the CaCO(3) recovered using Na(2)CO(3) and ammonium-based reagents of 49 and 34% respectively confirmed their observed neutralization potentials and acid neutralization capacities, while energy dispersive X-ray fluorescence suggested absence of major oxide impurities, with the exception of residual SO(4)(2-) and Na(2)O which still requires further reduction in the respective compounds. PMID:22508119

Zvimba, J N; Mulopo, J; Bologo, L T; Mathye, M

2012-01-01

200

Docosahexaenoic acid and butyrate synergistically modulate intracellular calcium compartmentalization to induce colonocyte apoptosis  

E-print Network

and pathogenesis of colon cancer ........................1 Diet and colon cancer.............................................................................8 Ion transport across biological membranes..........................................13... BETWEEN DOCOSAHEXAENOIC ACID AND BUTYRATE ELICITS p53 INDEPENDENT APOPTOSIS VIA MITOCHONDRIAL CA 2+ ACCUMULATION IN HUMAN COLON CANCER CELLS AND IN RAT PRIMARY COLONIC CULTURE.............57 Experimental procedures...

Kolar, Satya Sree N.

2009-05-15

201

Prevention of cultured rat stellate cell transformation and endothelin-B receptor upregulation by retinoic acid  

PubMed Central

Physiologically, perisinusoidal hepatic stellate cells (HSC) are quiescent and store retinoids. During liver injury and in cell culture, HSC transform into proliferating myofibroblast-like cells that express ?-smooth muscle actin (?-sma) and produce excessive amounts of extracellular matrix. During transformation (also known as activation), HSC are depleted of the retinoid stores, and their expression of the endothelin-1 (ET-1) system is increased. ET-1 causes contraction of transformed HSC and is implicated in their proliferation and fibrogenic activity. In order to understand the association between retinoids, ET-1 and the activation of HSC, we investigated the effect of 13-cis-retinoic acid on the transformation of cultured HSC and the expression of ET-1 system. HSC derived from normal rat liver were maintained for 10–12 days in a medium supplemented with 5% serum and containing 2.5 ?M retinoic acid without or with 50 nM ET-1 (ETA+ETB agonist) or sarafotoxin S6c (ETB agonist). In another set of experiments, cells treated for 10–12 days with vehicle (ethanol) or retinoic acid were challenged with ET-1 or sarafotoxin S6c, and various determinations were made at 24 h. Retinoic acid inhibited transformation and proliferation of HSC as assessed by morphological characteristics, expression of ?-sma, bromodeoxyuridine incorporation and cell count. Retinoic acid also prevented upregulation of ETB receptors without affecting ET-1 or ETA expression. Total protein synthesis ([3H]leucine incorporation), collagen ? types I mRNA expression and collagen synthesis ([3H]proline incorporation) were lower in retinoic acid-treated cells. Although ET-1-treated cells were morphologically similar to the control cells, their expression of ?-smooth muscle actin was significantly inhibited. The presence of retinoic acid in the medium during treatment with ET-1 caused further reduction in the expression of ?-smooth muscle actin. ET-1 and sarafotoxin S6c stimulated total protein synthesis in vehicle- and retinoic acid-treated cells, but collagen synthesis only in the latter. These results showing prevention of HSC activation and negative regulation of ETB receptor expression in them by retinoic acid may have important pathophysiologic implications. PMID:12813000

Chi, Xuedong; Anselmi, Kristin; Watkins, Simon; Gandhi, Chandrashekhar R

2003-01-01

202

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

PubMed Central

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

2014-01-01

203

Effects of the N/L-Type Calcium Channel Blocker Cilnidipine on Nephropathy and Uric Acid Metabolism in Hypertensive Patients With Chronic Kidney Disease (J-CIRCLE Study).  

PubMed

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

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

2014-10-01

204

Investigation, using rat embryo culture, of the role of methionine supply in folic acid-mediated prevention of neural tube defects  

Microsoft Academic Search

Peri-conceptional folic acid supplementation has become a well established way to prevent neural tube defects (NTDs) and such supplementation reduces the prevalence of these defects by approximately 70%. However, the mechanism of the preventive effect of folic acid is not clear. This overview focuses on the biochemical basis of folic acid-preventable NTDs and on the results obtained with whole embryo

L. A. G. J. M. Vanaerts

1995-01-01

205

The Role of n-3 Polyunsaturated Fatty Acids in the Prevention and Treatment of Breast Cancer  

PubMed Central

Breast cancer (BC) is the most common cancer among women worldwide. Dietary fatty acids, especially n-3 polyunsaturated fatty acids (PUFA), are believed to play a role in reducing BC risk. Evidence has shown that fish consumption or intake of long-chain n-3 PUFA, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are beneficial for inhibiting mammary carcinogenesis. The evidence regarding ?-linolenic acid (ALA), however, remains equivocal. It is essential to clarify the relation between ALA and cancer since ALA is the principal source of n-3 PUFA in the Western diet and the conversion of ALA to EPA and DHA is not efficient in humans. In addition, the specific anticancer roles of individual n-3 PUFA, alone, have not yet been identified. Therefore, the present review evaluates ALA, EPA and DHA consumed individually as well as in n-3 PUFA mixtures. Also, their role in the prevention of BC and potential anticancer mechanisms of action are examined. Overall, this review suggests that each n-3 PUFA has promising anticancer effects and warrants further research. PMID:25412153

Liu, Jiajie; Ma, David W. L.

2014-01-01

206

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

SciTech Connect

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

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

1994-12-31

207

Effects of aluminum and acid on calcium uptake by the crayfish Orconectes virilis  

Microsoft Academic Search

Aluminum increases in concentration in acidified waters and is sometimes more toxic to aquatic organisms at acidic than at neutral pH. This paper examined the interaction of pH and Al in inhibiting uptake of Ca++ from lake water by postmolt crayfish,Orconectes virilis (Hagen). Aluminum at 200 µg\\/L in non-acidified media had no effect on45Ca uptake. Media at pH 5.5 without

D. F. Malley; P. S. S. Chang

1985-01-01

208

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

Microsoft Academic Search

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

A. Mehlich

1978-01-01

209

Two-dimensional multiwavelength fluorescence spectra of dipicolinic acid and calcium dipicolinate  

Microsoft Academic Search

Dipicolinic acid (DPA) and the Ca2+ complex of DPA (CaDPA) are major chemical components of bacterial spores. With fluorescence being considered for the detection and identification of spores, it is important to understand the optical properties of the major components of the spores. We report in some detail on the room-temperature fluorescence excitation and emission spectra of DPA and its

Sivananthan Sarasanandarajah; Joseph Kunnil; Burt V. Bronk; Lou Reinisch

2005-01-01

210

Calcium influx is required for tannin-mediated arachidonic acid release from alveolar macrophages.  

PubMed

The role of Ca2+ was investigated in the response of alveolar macrophages to cotton tannin, an agent implicated in the lung disease byssinosis in textile mill workers. A physiological concentration of extracellular Ca2+ was found to be required for tannin-mediated release of radiolabeled arachidonic acid (AA). Flow cytometry using indo 1 indicated that tannin caused a rapid and dose-dependent Ca2+ increase in macrophages that also required extracellular Ca2+. Ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid virtually abolished the Ca2+ influx mediated by tannin but had little effect on intracellular Ca2+ release induced by thapsigargin, N-formylmethionyl-leucylphenylalanine, or thimerosal. A mechanism for extracellular Ca2+ influx was demonstrated by rapid Mn2+ quenching of indo 1 by tannin. Verapamil inhibited tannin-mediated Ca2+ influx and AA release, but the effective concentration was 100 microM. 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid chelated all Ca2+ in the cells and effectively abolished the tannin response. Exposure to tannin was not associated with cytotoxicity, as judged by 51Cr release. The data suggest that tannin induces Ca2+ influx in alveolar macrophages, which represents an important prerequisite for a cell-signaling pathway resulting in the accumulation of free AA. PMID:7840226

Bates, P J; Ralston, N V; Vuk-Pavlovi?, Z; Rohrbach, M S

1995-01-01

211

Calcium supplements  

MedlinePLUS

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

212

4-Phenylbutyric acid prevent cytotoxicity induced by thapsigargin in rat cardiac fibroblast.  

PubMed

Cardiac fibroblast (CF) survival is important for the maintenance of the extracellular matrix homeostasis in the heart; providing a functional support to cardiomyocytes necessary for the correct myocardial function. Endoplasmic reticulum (ER) stress causes cellular dysfunction and cell death by apoptosis; and thapsigargin is a well-known ER stress inducer. On the other hand, the chemical chaperone, 4-phenylbutyric acid (4-PBA) had showed to prevent ER stress; however, in cardiac fibroblast both the ER stress induced by thapsigargin and prevention by 4-PBA, have not been studied in detail. Neonate rat CF were treated with thapsigargin in presence or absence of 4-PBA, and cell viability was evaluated by trypan blue exclusion and apoptosis by flow cytometry; whereas CHOP, BIP, PDI, ATF4 and procollagen protein levels were assessed by western blot. In CF, thapsigargin triggered the unfolded protein response detected by early increases in ATF4, CHOP, PDI and BIP protein levels as well as, the accumulation of intracellular procollagen. Thapsigargin also stimulated CF death in a time and concentration-dependent manner. ER stress, CF death and apoptosis induced by thapsigargin were prevented by 4-PBA. Conclusion our data suggest that 4-PBA prevent ER stress, intracellular procollagen accumulation, CF death and apoptosis induced by thapsigargin. PMID:25149584

Humeres, C; Montenegro, J; Varela, M; Ayala, P; Vivar, R; Letelier, A; Olmedo, I; Catalán, M; Rivas, C; Baeza, P; Muñoz, C; García, L; Lavandero, S; Díaz-Araya, G

2014-12-01

213

Effect of folinic acid on the capacity of trimethoprim-sulfamethoxazole to prevent and treat Pneumocystis carinii pneumonia in rats.  

PubMed

Daily administration of 1 mg of folinic acid to immunosuppressed rats with incipient or established Pneumocystis carinii pneumonia did not impair the capacity of trimethoprim-sulfamethoxazole to either prevent or treat this disease. These observations constitute the first experimental support for the use of folinic acid to prevent or control cytopenias that occur in patients with Pneumocystis carinii pneumonia who are under trimethoprim-sulfamethoxazole treatment. PMID:3487285

D'Antonio, R G; Johnson, D B; Winn, R E; van Dellen, A F; Evans, M E

1986-02-01

214

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

PubMed

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

Abdel-Malak, Rania; Ahearn, Gregory A

2014-03-01

215

Omega-3 Fatty Acid is a potential preventive agent for recurrent colon cancer.  

PubMed

Increasing evidence supports the contention that many malignancies, including sporadic colorectal cancer, are driven by the self-renewing, chemotherapy-resistant cancer stem/stem-like cells (CSC/CSLC), underscoring the need for improved preventive and therapeutic strategies targeting CSCs/CSLCs. Omega-3 polyunsaturated fatty acids (?-3 PUFA), have been reported to inhibit the growth of primary tumors, but their potential as a preventive agent for recurring cancers is unexplored. The primary objectives of this investigation are (i) to examine whether eicosapentaenoic acid (EPA; one of the ?-3 PUFA) synergizes with FuOx (5-FU+Oxaliplatin), the backbone of colon cancer chemotherapy, and (ii) whether EPA by itself or in combination with conventional chemotherapy prevents the recurrence of colon cancer via eliminating/suppressing CSCs/CSLCs. FuOx-resistant (chemoresistant; CR) colon cancer cells, highly enriched in CSCs, were used for this study. Although EPA alone was effective, combination of EPA and FuOx was more potent in (i) inhibiting cell growth, colonosphere formation, and sphere-forming frequency, (ii) increasing sphere disintegration, (iii) suppressing the growth of SCID mice xenografts of CR colon cancer cells, and (iv) decreasing proinflammatory metabolites in mice. In addition, EPA + FuOx caused a reduction in CSC/CSLC population. The growth reduction by this regimen is the result of increased apoptosis as evidenced by PARP cleavage. Furthermore, increased pPTEN, decreased pAkt, normalization of ?-catenin expression, localization, and transcriptional activity by EPA suggests a role for the PTEN-Akt axis and Wnt signaling in regulating this process. Our data suggest that EPA by itself or in combination with FuOx could be an effective preventive strategy for recurring colorectal cancer. Cancer Prev Res; 7(11); 1138-48. ©2014 AACR. PMID:25193342

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

2014-11-01

216

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. PMID:19481937

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

2009-01-01

217

[Calcium ions, glutaminate acid, hypothalamic-pituitary-adrenal axis, calcium dependent ATP-ase as causes of oxidative damage in depression patients--Part I].  

PubMed

Depressive disorder is still a rising and important problem in the modem world, it affects about 15% of the population. Present forms of treatment are effective in about 70% and require monthly therapy which sometimes causes side effects. Last decade studies paid attention to theories different to monoaminergic and to neurodegenerative changes mainly in the limbic system of hippocampus. In this article authors show a relationship between calcium ions, glutaminergic transduction and disfunction of hypothalamic-pituitary-adrenal (HPA) axis. They also take into account the activity of calcium dependent ATPase and its influence on overproduction of reactive oxygen species in the central neuron system (CNS). The first part of this article proves that disregulation of HPA increases the glutaminergic conduction in neurons and causes a cytoskeletal damage in the CNS. PMID:18432134

Ga?ecki, Piotr; Florkowski, Antoni; Mrowicka, Ma?gorzata; Malinowska, Katarzyna; Ga?ecka, Elzbieta

2007-12-01

218

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

219

Microwave-assisted synthesis of biocompatible europium-doped calcium hydroxyapatite and fluoroapatite luminescent nanospindles functionalized with poly(acrylic acid).  

PubMed

Europium-doped calcium hydroxyapatite and fluoroapatite nanophosphors functionalized with poly(acrylic acid) (PAA) have been synthesized through a one-pot microwave-assisted hydrothermal method from aqueous basic solutions containing calcium nitrate, sodium phosphate monobasic, and PAA, as well as sodium fluoride in the case of the fluoroapatite particles. In both cases a spindlelike morphology was obtained, resulting from an aggregation process of smaller subunits which also gave rise to high specific surface area. The size of the nanospindles was 191 (32) × 40 (5) nm for calcium hydroxyapatite and 152 (24) × 38 (6) nm for calcium fluoroapatite. The luminescent nanoparticles showed the typical red luminescence of Eu(3+), which was more efficient for the fluoroapatite particles than for the hydroxyapatite. This is attributed to the presence of OH(-) quenchers in the latter. The nanophosphors showed negligible toxicity for Vero cells. Both PAA-functionalized nanophosphors showed a very high (up to at least 1 week) colloidal stability in 2-(N-morpholino)ethanesulfonic acid (MES) at pH 6.5, which is a commonly used buffer for physiological pH. All these features make both kinds of apatite-based nanoparticles promising tools for biomedical applications, such as luminescent biolabels and tracking devices in drug delivery systems. PMID:23317411

Escudero, Alberto; Calvo, Mauricio E; Rivera-Fernández, Sara; de la Fuente, Jesús M; Ocaña, Manuel

2013-02-12

220

Quercetin antagonism of GABAA?? receptors is prevented by ascorbic acid through a redox-independent mechanism.  

PubMed

Quercetin is a natural flavonoid widely distributed in plants that acts as a neuroprotective agent and modulates the activity of different synaptic receptors and ion channels, including the ionotropic GABA receptors. GABA(A??) receptors were shown to be antagonized by quercetin, but the mechanisms underlying these antagonistic actions are still unknown. We have analyzed here if the antagonistic action produced by quercetin on GABA(A??) receptors was related to its redox activity or due to alternative mechanism/s. Homomeric GABA(A??) receptors were expressed in frog oocytes and GABA-evoked responses electrophysiologically recorded. Quercetin effects on GABA(A??) receptors were examined in the absence or presence of ascorbic acid. Chemical protection of cysteines by selective sulfhydryl reagents and site directed mutagenesis experiments were also used to determine ?? subunit residues involved in quercetin actions. Quercetin antagonized GABA(A??) receptor responses in a dose-dependent, fast and reversible manner. Quercetin inhibition was prevented in the presence of ascorbic acid, but not by thiol reagents that modify the extracellular Cys-loop of these receptors. H141, an aminoacidic residue located near to the ?? subunit GABA binding site, was involved in the allosteric modulation of GABA(A??) receptors by several agents including ascorbic acid. Quercetin similarly antagonized GABA-evoked responses mediated by mutant (H141D)GABA(A??) and wild-type receptors, but prevention exerted by ascorbic acid on quercetin effects was impaired in mutant receptors. Taken together the present results suggest that quercetin antagonistic actions on GABA(A??) receptors are mediated through a redox-independent allosteric mechanism. PMID:23916728

Calero, Cecilia I; Beltrán González, Andrea N; Gasulla, Javier; Alvarez, Silvia; Evelson, Pablo; Calvo, Daniel J

2013-08-15

221

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

222

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

PubMed

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

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

2011-08-01

223

Long-term colloidal stability of 10 carbon nanotube types in the absence/presence of humic acid and calcium.  

PubMed

The colloidal stabilities of ten carbon nanotubes (CNTs) having varying physico-chemical properties were compared in long-term experiments. The presence of Suwannee River Humic Acid (SRHA) increased the fraction of CNTs in the supernatants (4-88% for the various CNT types) after addition in pre-dispersed form and 20 days of shaking and 5 days of settling. These suspensions were monomodal, containing individually suspended CNTs with highly negative surface charges. Calcium (2 mM) removed most of the CNT types from the supernatant, due to CNT-agglomerate formation initiated by reduction in surface charge. The amount of SRHA adsorbed to the different CNT types did not correlate (r(2) < 0.1) with the percentage of CNTs remaining in suspension. Multiple linear regression analysis revealed that the oxygen content and the diameter of the CNTs significantly influenced the percentage of stabilized CNTs, resulting in an increased fraction of functionalized and large-diameter CNTs that remained in suspension. PMID:22683482

Schwyzer, Irène; Kaegi, Ralf; Sigg, Laura; Smajda, Rita; Magrez, Arnaud; Nowack, Bernd

2012-10-01

224

An acidic peptide sequence of nucleolin-related protein can mediate the attachment of calcium oxalate to renal tubule cells.  

PubMed

Crystals that form in tubular fluid must be retained in the kidney to become stones. Nucleolin-related protein (NRP) is found on the surface of inner medullary collecting duct (IMCD) cells in culture (cIMCD) and selectively adsorbs to calcium oxalate (CaOx). We proposed that NRP mediates attachment to the renal tubular epithelium of Ca stone crystals through an electrostatic interaction with a highly acidic region (acidic fragment [AF]) similar to those of other proteins that have been reported to affect urinary crystal formation. The current studies demonstrate that nucleolin is expressed on both apical and basolateral cell surfaces of cIMCD, reaching a peak in the late stages of mitosis and gradually declining to undetectable levels with maturation of the polarized epithelium. Scraping areas of mature monolayers stimulated the cells surrounding the defects to migrate and proliferate so as to repair them, and these areas demonstrate surface NRP expression and enhanced attachment of CaOx monohydrate crystals. Surface expression of the NRP AF was produced by cloning the NRP AF into a display vector. Transfected cIMCD demonstrating copious surface expression of AF enhanced CaOx attachment 6.7-fold compared with control cIMCD, whereas cells transfected with a vector without the AF did not differ from control. AF was also cloned into a replication-deficient adenovirus and expressed in 293 cells, resulting in AF secretion into the nutrient medium. This medium inhibited CaOx attachment to cIMCD, compared with conditioned medium from cells infected with wild-type virus. These results demonstrate that surface-bound AF can mediate CaOx attachment and that secreted AF can inhibit attachment. These results support the notion that surface-associated NRP could mediate attachment of CaOx to the renal tubule epithelium, thereby causing retention of crystals that might eventually become kidney stones. PMID:15284292

Sorokina, Elena A; Wesson, Jeffrey A; Kleinman, Jack G

2004-08-01

225

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

226

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. PMID:25019084

Carvajal, Jorge A.

2014-01-01

227

Micro Determination of Calcium  

Microsoft Academic Search

Hildebrand and Reilly1 have recently described a complexometric titration method for the determination of calcium: the indicator used, `Calcon', is superior to `Solochrome' black in that calcium can be determined independently of magnesium, and, unlike the murexide method, a sharp end-point is obtained. All three methods employ ethylenediamine tetraacetic acid. The purpose of the present communication is to direct attention

A. B. Gilbert

1959-01-01

228

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. PMID:23610531

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

2013-01-01

229

Role of calcium and free fatty acids in epinephrine-induced myocardial necrosis  

SciTech Connect

A possible mechanism by which large doses of catecholamines produce myocardial necrosis was investigated. Male Sprague-Dawley rats, 275 to 325 g in weight, were injected once, sc, with 3 mg/kg epinephrine (E) or infused iv for 1 hr with E at a rate of 1.2 or 1.7 micrograms/min, and also injected iv with either 45Ca or (3H)palmitic acid (3H-PA) at the same time as or at various periods of time after E administration but exactly 0.5 or 1 hr before death. Controls were injected with saline solution. Heart/plasma ratios of radioactivity (H/P) were determined. The ratios increased in the case of both 45Ca and (3H)PA within 0.5 hr after E, reached peak values after 18 to 24 hr with 45Ca and 3 to 6 hr with (3H)PA, and remained above values for the controls for at least 72 hr with 45Ca and 48 hr with (3H)PA. The rate of 45Ca influx into heart 20 hr after E administration paralleled the severity of the myocardial damage that had been produced. When 45Ca and E were injected simultaneously, H/P increased progressively with time to 30 times control values, indicating the accumulation and retention of Ca in the heart. Under the same conditions, H/P values with (3H)PA also rose but remained constant at a level two to three times that in controls. Total cardiac free fatty acids (FFA) rose slightly and remained constant at the elevated level. It was not possible to distinguish a given point in time at which the increase in either Ca or FFA influx, initially due to the normal pharmacological effect of E, began to occur as a consequence of damage produced by the latter. It is concluded that high concentrations of catecholamines promote the deposition of Ca and FFA in myocardial cells in various forms, and that the deposition of these substances as soaps in the plasma membranes may cause permeability changes that lead to cell injury.

Mallov, S.

1983-11-01

230

Controlled release of rhBMP-2 loaded poly( dl-lactic- co-glycolic acid)\\/calcium phosphate cement composites in vivo  

Microsoft Academic Search

The release kinetics of recombinant human bone morphogenetic protein-2 (rhBMP-2) loaded poly(dl-lactic-co-glycolic acid)\\/calcium phosphate cement (PLGA\\/Ca–P cement) composites were studied in vivo. RhBMP-2 was radiolabeled with 131I and entrapped within PLGA microparticles or adsorbed onto the microparticle surface. PLGA microparticles were prepared of high molecular weight (HMW) PLGA (weight average molecular weight [Mw] 49,100±1700) or low molecular weight (LMW) PLGA

P. Q. Ruhé; O. C. Boerman; F. G. M. Russel; P. H. M. Spauwen; A. G. Mikos; J. A. Jansen

2005-01-01

231

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

232

Prevention of Acute Kidney Injury by Tauroursodeoxycholic Acid in Rat and Cell Culture Models  

PubMed Central

Background Acute kidney injury (AKI) has grave short- and long-term consequences. Often the onset of AKI is predictable, such as following surgery that compromises blood flow to the kidney. Even in such situations, present therapies cannot prevent AKI. As apoptosis is a major form of cell death following AKI, we determined the efficacy and mechanisms of action of tauroursodeoxycholic acid (TUDCA), a molecule with potent anti-apoptotic and pro-survival properties, in prevention of AKI in rat and cell culture models. TUDCA is particularly attractive from a translational standpoint, as it has a proven safety record in animals and humans. Methodology/Principal Findings We chose an ischemia-reperfusion model in rats to simulate AKI in native kidneys, and a human kidney cell culture model to simulate AKI associated with cryopreservation in transplanted kidneys. TUDCA significantly ameliorated AKI in the test models due to inhibition of the mitochondrial pathway of apoptosis and upregulation of survival pathways. Conclusions This study sets the stage for testing TUDCA in future clinical trials for prevention of AKI, an area that needs urgent attention due to lack of effective therapies. PMID:23152827

Li, Shunan; Abedin, Md. Joynal; Noppakun, Kajohnsak; Wang, Lawrence; Kaur, Tarundeep; Najafian, Behzad; Rodrigues, Cecilia M. P.

2012-01-01

233

Putative amino acid sequence of chick calcium-binding protein deduced from a complementary DNA sequence.  

PubMed Central

Two DNA fragments coding for chick CaBP have been isolated and sequenced. cDNA was prepared from enriched intestinal mRNA and cloned in pUC12. The recombinant clones were screened by differential hybridisation with 32P-cDNA probes synthesized from vitamin D replete and deficient chick intestinal mRNA. Two clones had outstanding affinity with the +D probe. Hybrid-arrested and hybrid-selected translation systems showed that both clones hybridised to mRNA coding for immunoprecipitable CaBP. The mRNA for CaBP has a 100 bp G,C rich sequence before a 786 bp coding region followed by 1250 nucleotides 3' untranslated region. Nucleotides coding for the Ca-binding sites show a high degree of homology for Ca-binding sites in chick calmodulin and rat intestinal CaBP. The amino acid sequence specified by the longest open reading frame contains five Ca-binding sites but is too large for the native CaBP; post-translational modification must therefore occur. PMID:3841205

Wilson, P W; Harding, M; Lawson, D E

1985-01-01

234

Study on analysis of waste edible oil with deterioration and removal of acid value, carbonyl value, and free fatty acid by a food additive (calcium silicate).  

PubMed

This study investigated the regeneration of waste edible oil using a food additive (calcium silicate, CAS). Waste edible oil was prepared by combined heat and aeration treatment. Moreover, the deterioration of edible oil by combined heat and aeration treatment was greater than that by heat treatment alone. The acid value (AV) and carbonyl value (CV) increased with increasing deterioration; conversely, the tocopherol concentration decreased with increasing deterioration. The specific surface area, pore volume, and mean pore diameter of the 3 CAS formulations used (CAS30, CAS60, and CAS90) were evaluated, and scanning electron microscopic images were taken. The specific surface area increased in the order of CAS30 (115.54 m(2)/g) < CAS60 (163.93 m(2)/g) < CAS90 (187.47 m(2)/g). The mean pore diameter increased in the order of CAS90 (170.59 Å) < CAS60 (211.60 Å) < CAS30 (249.70 Å). The regeneration of waste edible oil was possible with CAS treatment. The AV reduced by 15.2%, 10.8%, and 23.1% by CAS30, CAS60, and CAS90 treatment, respectively, and the CV was reduced by 35.6%, 29.8%, and 31.3% by these 3 treatments, respectively. Moreover, the concentrations of tocopherol and free fatty acids did not change with CAS treatment. The characteristics of CAS were not related to the degree of change of AV and CV. However, the adsorption mechanism of polar and non-polar compounds generated in waste edible oil by CAS was related with the presence of silica gel molecules in CAS. The findings indicated that CAS was useful for the regeneration of waste edible oil. PMID:23391535

Ogata, Fumihiko; Tanaka, Yuko; Tominaga, Hisato; Kangawa, Moe; Inoue, Kenji; Ueda, Ayaka; Iwata, Yuka; Kawasaki, Naohito

2013-01-01

235

The PI3K/Akt and ERK1/2 signaling pathways mediate the erythropoietin-modulated calcium influx in kainic acid-induced epilepsy.  

PubMed

Erythropoietin (EPO) suppresses epileptogenesis and limits the neuronal damage associated with recurrent seizures, but the neurocellular mechanism is unclear. Dysregulation of intracellular calcium homeostasis is a key pathogenic event leading to the progression of epileptic activity, suggesting that EPO may suppress seizures by stabilizing intracellular calcium. In this study, we examined the effects of EPO on voltage-gated Ca(2+) influx in cultured rat hippocampal neurons and population spike (PS) amplitude in kainic acid (KA)-induced rats and the mechanisms responsible. KA injection markedly increased EPO and EPO receptor expression and the amplitude of PS in the hippocampal CA3 region, evoked by perforant pathway stimulation. Intracerebroventricular injection of exogenous rat recombinant EPO reversed KA-induced PS amplitude in the hippocampal CA3 region. Similarly, rat recombinant EPO pretreatment attenuates the increased voltage-gated calcium current's (I(Ca)) amplitude and density induced by KA in cultured hippocampal neurons. In contrast, transient transfection of rat EPO small interfering RNS (siRNA) further enhanced I(Ca) amplitude and density in the presence of KA, whereas a scrambled control siRNA had no effect. Further, EPO activates the PI3K and ERK1/2 pathways in cultured hippocampal neurons, and the PI3K/Akt inhibitor LY294002 and ERK1/2 inhibitor U0126 both blocked, at least in part, the suppressive effect of exogenous EPO on KA-induced calcium currents. This study indicates that both endogenous and exogenous EPO decrease KA-sensitive calcium influx and concomitant hyperexcitability in hippocampal neurons. The results also demonstrate that the PI3K/Akt and ERK1/2 signaling pathways mediate the EPO-modulated calcium influx in KA-induced epilepsy. PMID:23518641

Zheng, Honghua; Wang, Xiaojing; Tang, Zhengang; Zheng, Weihong; Li, Zhengli

2013-04-17

236

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. PMID:21130106

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

2011-01-01

237

Do Omega-3 Polyunsaturated Fatty Acids Prevent Cardiovascular Disease? A Review of the Randomized Clinical Trials  

PubMed Central

Fish oil is rich in the omega-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Numerous epidemiological studies and several large randomized clinical trials have shown that modest doses of omega-3 PUFAs significantly reduce the risk of unstable angina, myocardial infarction, and sudden cardiac death as well as death in coronary artery disease and heart failure patients. Based on the scientific evidence, the American Heart Association (AHA) has recommended all individuals eat fish at least twice a week to prevent cardiovascular disease. For individuals with coronary artery disease, the recommended dose of omega-3 PUFAs is 1 g of EPA and DHA daily. To lower triglyceride levels, much higher doses are needed. However, more recent randomized clinical trials have questioned the cardiovascular benefits of fish oil. These studies have contributed to the uncertainty health care providers face when recommending omega-3 PUFA supplementation according to clinical guidelines. The purpose of this review is to examine the randomized clinical trials and scientific evidence between omega-3 PUFAs and cardiovascular outcomes to better understand the current role of omega-3 PUFAs in improving cardiovascular health.

Kimmig, Lucas M; Karalis, Dean G

2013-01-01

238

Structure and dynamics of dimyristoylphosphatidic acid/calcium complexes by sup 2 H NMR, infrared, and Raman spectroscopies and small-angle X-ray diffraction  

SciTech Connect

The structural and dynamic properties of complexes of dimyristoylphosphatidic acid (DMPA) and calcium ions have been characterized by {sup 2}H NMR, Raman, and infrared spectroscopies and small-angle X-ray diffraction. All techniques used show that these complexes do not undergo a cooperative thermotropic phase transition. Small-angle X-ray diffraction unambiguously demonstrates that the structure of the lipid molecules of the DMPA/Ca{sup 2+} complexes remains lamellar even at a temperature as high as 85C. Raman results indicate that within this temperature range, only a few trans-gauche isomerizations of the C-C bonds of the phospholipid acyl chains arise in this system. The {sup 2}H NMR spectra indicate that the DMPA chains are highly motionally restricted up to 65C and that higher temperatures might activate some low-frequency overall motions of entire lamellar domains. Small-angle X-ray scattering and {sup 2}H NMR spectroscopy of {sup 2}H{sub 2}O also show that the interaction of calcium with DMPA promotes an important dehydration of the lipid assembly, even though the latter technique clearly demonstrates that some water molecules remain strongly bond in the DMPA/Ca{sup 2+} complexes. Finally, comparison of the phosphate stretching mode region of the infrared spectra of complexes of DMPA with calcium ions with those model compounds provides strong evidence that calcium ions bind to both charges of the phosphate group of DMPA and form bridges between adjacent bilayers.

Laroche, G.; Pezolet, M. (Universite Laval, Quebec (Canada)); Dufourc, E.J.; Dufourcq, J. (Centre de Recherche Paul Pascal/CNRS, Pessac (France))

1991-03-26

239

?-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

240

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

241

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

NSDL National Science Digital Library

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

Jay Ramadoss (University of Wisconsin); Emilie R Lunde (College of Veterinary Medicine and Biomedical Sciences Veterinary Physiology and Pharmacology); Nengtai Ouyang (Texas A&M College of Veterinary Medicine and Biomedical Sciences Veterinary Physiology and Pharmacology); Wei-Jung A Chen (Texas A&M HSC Neuroscience and Experimental Therapeutics); Dr. Timothy A. Cudd (Texas A&M University Dept. of Veterinary Physiology and Pharmacology)

2008-05-22

242

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

PubMed

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

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

2014-11-01

243

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

PubMed Central

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

2013-01-01

244

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

PubMed Central

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

2014-01-01

245

Hydrogen sulfide prevents hypoxia-induced apoptosis via inhibition of an H2O2-activated calcium signaling pathway in mouse hippocampal neurons.  

PubMed

Hydrogen sulfide (H(2)S), an endogenous gaseous mediator, has been shown to exert protective effects against damage to different organs in the human body caused by various stimuli. However, the potential effects of H(2)S on hypoxia-induced neuronal apoptosis and its mechanisms remain unclear. Here, we exposed mouse hippocampal neurons to hypoxic conditions (2% O(2), 5% CO(2) and 93% N(2) at 37 °C) to establish a hypoxic cell model. We found that 4-h hypoxia treatment significantly increased intracellular reactive oxygen species (ROS) levels, and pretreatment with NaHS (a source of H(2)S) for 30 min suppressed hypoxia-induced intracellular ROS elevation. The hypoxia treatment significantly increased cytosolic calcium ([Ca(2+)](i)), and pretreatment with NaHS prevented the increase in [Ca(2+)](i). Additionally, polyethylene glycol (PEG)-catalase (a H(2)O(2) scavenger) but not PEG-SOD (an O(2)(-) scavenger) conferred an inhibitory effect similar to H(2)S on the hypoxia-induced increase in [Ca(2+)](i). Furthermore, we found that pretreatment with NaHS could significantly inhibit hypoxia-induced neuronal apoptosis, which was also inhibited by PEG-catalase or the inositol 1,4,5-triphosphate (IP(3)) receptor blocker xestospongin C. Taken together, these findings suggest that H(2)S inhibits hypoxia-induced apoptosis through inhibition of a ROS (mainly H(2)O(2))-activated Ca(2+) signaling pathway in mouse hippocampal neurons. PMID:22846576

Luo, Yougen; Liu, Xiaoai; Zheng, Qisheng; Wan, Xiaomei; Ouyang, Shuichang; Yin, Yedong; Sui, Xiaojing; Liu, Jianjun; Yang, Xifei

2012-08-24

246

Abscisic acid does not evoke calcium influx in murine primary microglia and immortalised murine microglial BV-2 and N9 cells.  

PubMed

Brain microglia are resident macrophage-like cells representing the first and main form of active immune response during brain injury. Microglia-mediated inflammatory events in the brain are known to be associated with chronic degenerative diseases such as Multiple Sclerosis, Parkinson's, or Alzheimer's disease. Therefore, identification of mechanisms activating microglia is not only important in the understanding of microglia-mediated brain pathologies, but may also lead to the development of new anti-inflammatory drugs for the treatment of chronic neurodegenerative diseases. Recently, abscisic acid (ABA), a phytohormone regulating important physiological functions in higher plants, has been proposed to activate murine microglial cell line N9 through increased intracellular calcium. In the present study, we determined the response to ABA and its analogues from murine primary microglia and immortalized murine microglial cell line BV-2 and N9 cells. A Fura-2-acetoxymethyl ester (Fura-2AM)-based ratiometric calcium imaging and measurement technique was used to determine the intracellular calcium changes in these cells when treated with (-)-ABA, (+)-ABA, (-)-trans-ABA and (+)-trans-ABA. Both primary microglia and microglial cell lines (BV-2 and N9 cells) showed significant increase in intracellular calcium ([Ca(2+)]i) in response to treatment with ATP and ionomycine. However, ABAs failed to evoke dose- and time-dependent [Ca(2+)]i changes in mouse primary microglia, BV-2 and N9 cells. Together, these surprising findings demonstrate that, contrary to that reported in N9 cells [3], ABAs do not evoke intracellular calcium changes in primary microglia and microglial cell lines. The broad conclusion that ABA evokes [Ca(2+)]i in microglia requires more evidence and further careful examination. PMID:20869945

Jiang, Susan X; Benson, Chantel L; Zaharia, L Irina; Abrams, Suzanne R; Hou, Sheng T

2010-10-22

247

RapA2 is a calcium-binding lectin composed of two highly conserved cadherin-like domains that specifically recognize Rhizobium leguminosarum acidic exopolysaccharides.  

PubMed

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

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

2013-01-25

248

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

PubMed Central

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

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

2013-01-01

249

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

250

Improved biocompatibility of poly(lactic-co-glycolic acid) orv and poly-L-lactic acid blended with nanoparticulate amorphous calcium phosphate in vascular stent applications.  

PubMed

Biodegradable polymers used as vascular stent coatings and stent platforms encounter a major challenge: biocompatibility in vivo, which plays an important role in in-stent restenosis (ISR). Co-formulating amorphous calcium phosphate (ACP) into poly(lactic-co-glycolic acid) (PLGA) or poly-L-lactic acid (PLLA) was investigated to address the issue. For stent coating applications, metal stents were coated with polyethylene-co-vinyl acetate/poly-n-butyl methacrylate (PEVA/PBMA), PLGA or PLGA/ACP composites, and implanted into rat aortas for one and three months. Comparing with both PEVA/PBMA and PLGA groups after one month, the results showed that stents coated with PLGA/ACP had significantly reduced restenosis (PLGA/ACP vs. PEVA/PBMA vs. PLGA: 21.24 +/- 2.59% vs. 27.54 +/- 1.19% vs. 32.12 +/- 3.93%, P < 0.05), reduced inflammation (1.25 +/- 0.35 vs. 1.77 +/- 0.38 vs. 2.30 +/- 0.21, P < 0.05) and increased speed of re-endothelialization (1.78 +/- 0.46 vs. 1.17 +/- 0.18 vs. 1.20 +/- 0.18, P < 0.05). After three months, the PLGA/ACP group still displayed lower inflammation score (1.33 +/- 0.33 vs. 2.27 +/- 0.55, P < 0.05) and higher endothelial scores (2.33 +/- 0.33 vs. 1.20 +/- 0.18, P < 0.05) as compared with the PEVA/PBMA group. Moreover, for stent platform applications, PLLA/ACP stent tube significantly reduced the inflammatory cells infiltration in the vessel walls of rabbit iliac arteries relative to their PLLA cohort (NF-kappaB-positive cells: 23.31 +/- 2.33/mm2 vs. 9.34 +/- 1.35/mm2, P < 0.05). No systemic biochemical or pathological evidence of toxicity was found in either PLGA/ACP or PLLA/ACP. The co-formulation of ACP into PLGA and PLLA resulted in improved biocompatibility without systemic toxicity. PMID:24749387

Zheng, Xiaoxin; Wang, Yujue; Lan, Zhiyuan; Lyu, Yongnan; Feng, Gaoke; Zhang, Yipei; Tagusari, Shizu; Kislauskis, Edward; Robich, Michael P; McCarthy, Stephen; Sellke, Frank W; Laham, Roger; Jiang, Xuejun; Gu, Wei Wang; Wu, Tim

2014-06-01

251

Oral Administration of Dihomo-?-Linolenic Acid Prevents Development of Atopic Dermatitis in NC\\/Nga Mice  

Microsoft Academic Search

Disorders of the metabolism of essential fatty acids (EFAs) are related to atopic dermatitis (AD). Concentrations of dihomo-?-linolenic\\u000a acid (DGLA), an EFA, in the serum of AD patients are lower than those in healthy volunteers. Recently we developed a fermented\\u000a DGLA oil, and examined whether oral administration of DGLA prevents development of dermatitis in NC\\/Nga mice, which spontaneously\\u000a develop human

H. Kawashima; N. Tateishi; A. Shiraishi; N. Teraoka; T. Tanaka; A. Tanaka; H. Matsuda; Y. Kiso

2008-01-01

252

21 CFR 184.1207 - Calcium lactate.  

Code of Federal Regulations, 2010 CFR

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6 .xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2010-04-01

253

21 CFR 184.1207 - Calcium lactate.  

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6. xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2014-04-01

254

21 CFR 184.1207 - Calcium lactate.  

Code of Federal Regulations, 2012 CFR

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6 .xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2012-04-01

255

21 CFR 184.1207 - Calcium lactate.  

Code of Federal Regulations, 2013 CFR

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6 .xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2013-04-01

256

21 CFR 184.1207 - Calcium lactate.  

Code of Federal Regulations, 2011 CFR

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6 .xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2011-04-01

257

Preparation, mechanical property and cytocompatibility of poly(L-lactic acid)/calcium silicate nanocomposites with controllable distribution of calcium silicate nanowires.  

PubMed

How to accurately control the microstructure of bioactive inorganic/organic nanocomposites still remains a significant challenge, which is of great importance in influencing their mechanical strength and biological properties. In this study, using a combined method of electrospinning and hot press processing, calcium silicate hydrate (CSH) nanowire/poly(L-lactide) (PLLA) nanocomposites with controllable microstructures and tailored mechanical properties were successfully prepared as potential bone graft substitutes. The electrospun hybrid nanofibers with various degrees of alignment were stacked together in a predetermined manner and hot pressed into hierarchically structured nanocomposites. The relationship between the microstructure and mechanical properties of the as-prepared nanocomposites were systematically evaluated. The results showed that CSH nanowires in a PLLA matrix were able to be controlled from completely randomly oriented to uniaxially aligned, and then hierarchically organized with different interlayer angles, leading to corresponding nanocomposites with improved mechanical properties and varied anisotropies. It was also found that the bending strength of nanocomposites with 5 wt.% CSH nanowires (130 MPa) was significantly higher than that of pure PLLA (86 MPa) and other composites. The addition of CSH nanowires greatly enhanced the hydrophilicity and apatite-forming ability of PLLA films, as well as the attachment and proliferation of bone marrow stromal cells. The study suggested that a combination of electrospinning and hot pressing is a viable means to control the microstructure and mechanical properties, and improve the mineralization ability and cellular responses, of CSH/PLLA nanocomposites for potential bone repair applications. PMID:22813849

Dou, Yuandong; Wu, Chengtie; Chang, Jiang

2012-11-01

258

Mechanism of the protective effect of supplemental dietary calcium on cytolytic activity of fecal water.  

PubMed

Dietary calcium supplementation inhibits hyperproliferation of rectal epithelium, possibly by precipitating luminal surfactants and thus preventing their cell-damaging effects. Therefore, we studied the effects of supplemental dietary calcium (35.5 mmol/day) on composition and cytolytic activity of fecal water and on the release of the epithelial marker alkaline phosphatase in 12 healthy volunteers. Fecal water was isolated by low-speed centrifugation. Cytolytic activity was determined as lysis of human erythrocytes by fecal water. Intestinal alkaline phosphatase activity in fecal water was measured with the use of the uncompetitive inhibitor L-phenylalanine. Supplemental calcium increased soluble calcium and decreased soluble P(i). The logarithm of the concentration product of calcium and phosphate was linearly dependent on pH. These observations indicate formation of insoluble calcium phosphate. Supplemental calcium did not alter the total bile acid concentration in fecal water but significantly decreased the ratio of more hydrophobic to more hydrophilic bile acids from 3.3 to 2.3. Calcium also significantly decreased the concentration of fatty acids (from 2.9 to 2.1 mM). Consistent with these decreases in hydrophobic surfactants, calcium decreased the cytolytic activity of fecal water from 47 +/- 9 to 27 +/- 8% (n = 12, P < 0.05). Analogous to the decrease in cytolytic activity, the release of the epithelial marker alkaline phosphatase was also lowered by supplemental calcium. We conclude that supplemental dietary calcium decreases luminal cytotoxic surfactant concentrations and thus inhibits luminal cytolytic activity and the release of the epithelial marker alkaline phosphatase as an indicator of intestinal epitheliolysis. This mechanism may explain how dietary calcium could decrease epithelial cell proliferation. PMID:8417817

Lapré, J A; De Vries, H T; Termont, D S; Kleibeuker, J H; De Vries, E G; Van der Meer, R

1993-01-15

259

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

260

Calcium channel blocker verapamil accelerates gambogic acid-induced cytotoxicity via enhancing proteasome inhibition and ROS generation.  

PubMed

Verapamil (Ver), an inhibitor of the multidrug resistance gene product, has been proved to be a promising combination partner with other anti-cancer agents including proteasome inhibitor bortezomib. Gambogic acid (GA) has been approved for Phase II clinical trials in cancer therapy in China. We have most recently reported that GA is a potent proteasome inhibitor, with anticancer efficiency comparable to bortezomib but much less toxicity. In the current study we investigated whether Ver can enhance the cytotoxicity of GA. We report that (i) the combination of Ver and GA results in synergistic cytotoxic effect and cell death induction in HepG2 and K562 cancer cell lines; (ii) a combinational treatment with Ver and GA induces caspase activation, endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production; (iii) caspase inhibitor z-VAD blocks GA+Ver-induced apoptosis but not proteasome inhibition; (iv) cysteine-containing compound N-acetylcysteine (NAC) prevents GA+Ver-induced poly(ADP-ribose) polymerase cleavage and proteasome inhibition. These results demonstrate that Ver accelerates GA-induced cytotoxicity via enhancing proteasome inhibition and ROS production. These findings indicate that the natural product GA is a valuable candidate that can be used in combination with Ver, thus representing a compelling anticancer strategy. PMID:24373880

Liu, Ningning; Huang, Hongbiao; Liu, Shouting; Li, Xiaofen; Yang, Changshan; Dou, Q Ping; Liu, Jinbao

2014-04-01

261

Zoledronic Acid Versus Alendronate for the Prevention of Bone Loss after Heart or Liver Transplantation  

PubMed Central

Context: The first year after transplantation is characterized by rapid bone loss. Objective: The aim of this study was to compare zoledronic acid (zoledronate) and alendronate for prevention of transplantation bone loss. Design and Setting: A randomized clinical trial was conducted at a transplantation center. Patients: The study included 84 adults undergoing heart or liver transplantation and a concurrently transplanted, nonrandomized reference group of 27 adults with T scores greater than ?1.5. Interventions: Alendronate (70 mg weekly for 12 months) or one 5-mg infusion of zoledronate were both initiated 26 ± 8 d after transplantation. Main Outcome Measures: The primary outcome was total hip bone mineral density (BMD) 1 yr after transplantation. Secondary outcomes included femoral neck and lumbar spine BMD and serum C-telopeptide, a bone resorption marker. Results: In the reference group, BMD declined at the spine and hip (P < 0.001). In the randomized groups, hip BMD remained stable. Spine BMD increased in the zoledronate group and did not change in the alendronate group; at 12 months, the 2.2% difference between groups (95% confidence interval, 0.6 to 3.9%; P = 0.009) favored zoledronate. In heart transplant patients, spine BMD declined in the alendronate and increased in the zoledronate group (?3.0 vs. +1.6%, respectively; between-group difference, 4.2%; 95% confidence interval, 2.1 to 6.3%; P < 0.001). In liver transplant patients, spine BMD increased comparably in both groups. Twelve-month C-telopeptide was lower in the zoledronate group than in the alendronate group (79 vs. 49%; P = 0.04). Conclusions: One 5-mg infusion of zoledronate and weekly alendronate prevent bone loss at the hip and, in liver transplant patients, increase spine BMD. In heart transplant patients, spine bone BMD remained stable with zoledronate but decreased with alendronate. PMID:23024190

Cohen, Adi; Stein, Emily M.; McMahon, Donald J.; Zhang, Chiyuan; Young, Polly; Pandit, Kavita; Staron, Ronald B.; Verna, Elizabeth C.; Brown, Robert; Restaino, Susan; Mancini, Donna

2012-01-01

262

Dietary Calcium Intake and The Prevalence of Calcium Supplement Use Among Well-Educated Women  

Microsoft Academic Search

LEARNING OUTCOME: To propagate among women the consumption of adequate dietary calcium to prevent osteoporosis.More women are seeking advice about calcium supplementation as awareness of osteoporosis increases. The purposes of this study were to determine the calcium content of women's diets to see if the recommended dietary allowance (RDA) was being met and to find out the prevalence of calcium

K. G. Galvacs

1997-01-01

263

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

264

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. PMID:24636283

Hannan, Johanna L.; Kutlu, Omer; Stopak, Bernard L.; Liu, Xiaopu; Castiglione, Fabio; Hedlund, Petter; Burnett, Arthur L.; Bivalacqua, Trinity J.

2014-01-01

265

S-acylation-dependent association of the calcium sensor CBL2 with the vacuolar membrane is essential for proper abscisic acid responses  

PubMed Central

Calcineurin B-like (CBL) proteins contribute to decoding calcium signals by interacting with CBL-interacting protein kinases (CIPKs). Currently, there is still very little information about the function and specific targeting mechanisms of CBL proteins that are localized at the vacuolar membrane. In this study, we focus on CBL2, an abundant vacuolar membrane-localized calcium sensor of unknown function from Arabidopsis thaliana. We show that vacuolar targeting of CBL2 is specifically brought about by S-acylation of three cysteine residues in its N-terminus and that CBL2 S-acylation and targeting occur by a Brefeldin A-insensitive pathway. Loss of CBL2 function renders plants hypersensitive to the phytohormone abscisic acid (ABA) during seed germination and only fully S-acylated and properly vacuolar-targeted CBL2 proteins can complement this mutant phenotype. These findings define an S-acylation-dependent vacuolar membrane targeting pathway for proteins and uncover a crucial role of vacuolar calcium sensors in ABA responses. PMID:22547024

Batistic, Oliver; Rehers, Marion; Akerman, Amir; Schlucking, Kathrin; Steinhorst, Leonie; Yalovsky, Shaul; Kudla, Jorg

2012-01-01

266

21 CFR 184.1195 - Calcium citrate.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

267

Inhibition of L-type calcium-channel activity by thapsigargin and 2,5-t-butylhydroquinone, but not by cyclopiazonic acid.  

PubMed

Thapsigargin (TG), 2,5-t-butylhydroquinone (tBHQ) and cyclopiazonic acid (CPA) all inhibit the initial Ca(2+)-response to thyrotropin-releasing hormone (TRH) by depleting intracellular Ca2+ pools sensitive to inositol 1,4,5-trisphosphate (IP3). Treatment of GH3 pituitary cells for 30 min with 5 nM TG, 500 nM tBHQ or 50 nM CPA completely eliminated the TRH-induced spike in intracellular free Ca2+ ([Ca2+]i). Higher concentrations of TG and tBHQ, but not CPA, were also found to inhibit strongly the activity of L-type calcium channels, as measured by the increase in [Ca2+]i or 45Ca2+ influx stimulated by depolarization. TG and tBHQ blocked high-K(+)-stimulated 45Ca2+ uptake, with IC50 values of 10 and 1 microM respectively. Maximal inhibition of L-channel activity was achieved 15-30 min after drug addition. Inhibition by tBHQ was reversible, whereas inhibition by TG was not. TG and CPA did not affect spontaneous [Ca2+]i oscillations when tested at concentrations adequate to deplete the IP3-sensitive Ca2+ pool. However, 20 microM TG and 10 microM tBHQ blocked [Ca2+]i oscillations completely. The effect of drugs on calcium currents was measured directly by using the patch-clamp technique. When added to the external bath, 10 microM CPA caused a sustained increase in the calcium-channel current amplitude over 8 min, 10 microM tBHQ caused a progressive inhibition, and 10 microM TG caused an enhancement followed by a sustained block of the calcium current over 8 min. In summary, CPA depletes IP3-sensitive Ca2+ stores and does not inhibit voltage-operated calcium channels. At sufficiently low concentrations, TG depletes IP3-sensitive stores without inhibiting L-channel activity, but, for tBHQ, inhibition of calcium channels occurs at concentrations close to those needed to block agonist mobilization of intracellular Ca2+. PMID:7520693

Nelson, E J; Li, C C; Bangalore, R; Benson, T; Kass, R S; Hinkle, P M

1994-08-15

268

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. PMID:23936022

Lin, I-Ling; Ho, Mei-Ling; Hsu, Pei-Chuan; Chen, Li-Wen; Chen, Ing-Jun; Yeh, Jwu-Lai

2013-01-01

269

{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

270

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

E-print Network

(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...

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

2002-02-01

271

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

272

21 CFR 184.1212 - Calcium pantothenate.  

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

2014-04-01

273

Insights into prevention of human neural tube defects by folic acid arising from consideration of mouse mutants.  

PubMed

Almost 30 years after the initial study by Richard W. Smithells and coworkers, it is still unknown how maternal periconceptional folic acid supplementation prevents human neural tube defects (NTDs). In this article, questions about human NTD prevention are considered in relation to three groups of mouse models: NTD mutants that respond to folate, NTD mutants and strains that do not respond to folate, and mutants involving folate-pathway genes. Of the 200 mouse NTD mutants, only a few have been tested with folate; half respond and half do not. Among responsive mutants, folic acid supplementation reduces exencephaly and/or spina bifida aperta frequency in the Sp(2H), Sp, Cd, Cited2, Cart1, and Gcn5 mutants. Prevention ranges from 35 to 85%. The responsive Sp(2H) (Pax3) mutant has abnormal folate metabolism, but the responsive Cited2 mutant does not. Neither folic nor folinic acid reduces NTD frequency in Axd, Grhl3, Fkbp8, Map3k4, or Nog mutants or in the curly tail or SELH/Bc strains. Spina bifida frequency is reduced in Axd by methionine and in curly tail by inositol. Exencephaly frequency is reduced in SELH/Bc by an alternative commercial ration. Mutations in folate-pathway genes do not cause NTDs, except for 30% exencephaly in folate-treated Folr1. Among folate-pathway mutants, neural tube closure is normal in Cbs, Folr2, Mthfd1, Mthfd2, Mthfr, and Shmt1 mutants. Embryos die by midgestation in Folr1, Mtr, Mtrr, and RFC1 mutants. The mouse models point to genetic heterogeneity in the ability to respond to folic acid and also to heterogeneity in genetic cause of NTDs that can be prevented by folic acid. PMID:19117321

Harris, Muriel J

2009-04-01

274

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

E-print Network

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

Wei Bu; Kevin Flores; Jacob Pleasants; David Vaknin

2009-01-16

275

Upregulation of the Human Alkaline Ceramidase 1 and Acid Ceramidase Mediates Calcium-Induced Differentiation of Epidermal Keratinocytes  

Microsoft Academic Search

Extracellular calcium (Cao2+) potently induces the growth arrest and differentiation of human epidermal keratinocytes (HEKs). We report that Cao2+ markedly upregulates the human alkaline ceramidase 1 (haCER1) in HEKs; and its upregulation mediates the Cao2+-induced growth arrest and differentiation of HEKs. haCER1 is the human ortholog of mouse alkaline ceramidase 1 that we previously identified. haCER1 catalyzed the hydrolysis of

Wei Sun; Ruijuan Xu; Wei Hu; Junfei Jin; Heather A. Crellin; Jacek Bielawski; Zdzislaw M. Szulc; Bruce H. Thiers; Lina M. Obeid; Cungui Mao

2008-01-01

276

Effect of different amounts and types of calcium on colonic cell proliferation and fecal bile acids concentration  

E-print Network

). Clinical trials support the epidemiological evidence . One study which was conducted in England compared the habitual diets of 50 patients with colorectal cancer to that of 50 closely matched controls. Patients with colorectal cancer were found... concluded that supplemental dietary calcium did not affect mucosal risk factors for colon cancer (37). Some clinical trials support epidemiologcal studies. In a separate clinical study, ten patients at high risk for familial colon cancer were given 1. 25g...

C?hen Hsiao-Ch?ing

2012-06-07

277

[Calcium--essential for everybody].  

PubMed

Calcium regulates majority of metabolic processes within human organism and its optimal intake decreases risk of metabolic illnesses conditioned by diet. Deficiency of calcium results in higher body max index, increase risk of insulin resistance, diabetes type 2 and osteoporosis. Diet delivering full calcium load diminished impendency of hypertension; calcium regulates tension of smooth muscles of blood vessels, limits neurotransmitters activity and also diminish hazardous activity of sodium chloride. Anticancerogenic activity of calcium results from formation insoluble bile acids and fat acids salts, and most of all, from inhibition of intestine mucosa cells hyper proliferation. Due to presence of vitamin D3, CLA, proteins and bioactive peptides emerging from them, milk is more efficient in prophylaxis of diet conditioned illnesses than calcium supplements. Efficiency of milk and dairy products in treatment of obesity, sclerosis and hypertension has been proved by DASH diet. PMID:25095643

Cichosz, Grazyna; Czeczot, Hanna

2014-06-01

278

Calcium revisited: part I  

PubMed Central

In February 2013, the US Preventive Services Task Force (see www.uspreventiveservicestaskforce.org) recommended ‘against daily supplementation with 400?IU or less of vitamin D3 and 1000, mg or less of calcium for the primary prevention of fractures in non institutionalized postmenopausal women', which illustrates the divergence of opinions. This review wants to shed an objective light on the importance of calcium for bone health. It cannot compete with an exhaustive analysis of the literature by an institute. It does not mention all significant references. But it highlights some pivotal studies from the past and it refers to recent studies that opened new views or added essential data to known facts. It also reflects the personal perception of the author. The first part deals mainly with intake, absorption, needs and recommendations; the second part will discuss the effects of calcium and its supplements on bone. PMID:24422133

Burckhardt, Peter

2013-01-01

279

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

PubMed Central

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

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

2013-01-01

280

Roles of Acidic Phospholipids and Nucleotides in Regulating Membrane Binding and Activity of a Calcium-independent Phospholipase A2 Isoform*  

PubMed Central

Phospholipase A2 activity plays key roles in generating lipid second messengers and regulates membrane topology through the generation of asymmetric lysophospholipids. In particular, the Group VIA phospholipase A2 (GVIA-iPLA2) subfamily of enzymes functions independently of calcium within the cytoplasm of cells and has been implicated in numerous cellular processes, including proliferation, apoptosis, and membrane transport steps. However, mechanisms underlying the spatial and temporal regulation of these enzymes have remained mostly unexplored. Here, we examine the subset of Caenorhabditis elegans lipases that harbor a consensus motif common to members of the GVIA-iPLA2 subfamily. Based on sequence homology, we identify IPLA-1 as the closest C. elegans homolog of human GVIA-iPLA2 enzymes and use a combination of liposome interaction studies to demonstrate a role for acidic phospholipids in regulating GVIA-iPLA2 function. Our studies indicate that IPLA-1 binds directly to multiple acidic phospholipids, including phosphatidylserine, phosphatidylglycerol, cardiolipin, phosphatidic acid, and phosphorylated derivatives of phosphatidylinositol. Moreover, the presence of these acidic lipids dramatically elevates the specific activity of IPLA-1 in vitro. We also found that the addition of ATP and ADP promote oligomerization of IPLA-1, which probably underlies the stimulatory effect of nucleotides on its activity. We propose that membrane composition and the presence of nucleotides play key roles in recruiting and modulating GVIA-iPLA2 activity in cells. PMID:23007400

Morrison, Kylee; Witte, Kristen; Mayers, Jonathan R.; Schuh, Amber L.; Audhya, Anjon

2012-01-01

281

Extraction and sorption of acetic acid at pH above pK{sub a} to form calcium magnesium acetate  

SciTech Connect

The use of rock salt for deicing roads has many negative effects on automobiles, highway systems, and the environment. Calcium magnesium acetate, hence-forth denoted CMA, has been identified as a more desirable, environmentally benign solid deicer for high-ways, airport runaways, and similar applications. CMA is also of interest as an additive for scavenging sulfur in combustion processes so as to reduce emissions of sulfur oxides and as a catalyst for coal gasification. Different extractants (trioctylphosphine oxide and secondary, tertiary, and quaternary amines) and solid sorbents (tertiary and quaternary amines) were investigated as agents for recovery of acetic acid as part of a process for production of CMA from fermentation acetic acid. The pH and temperature dependencies for uptake of acetic acid by these extractants and sorbents were measured, along with the degrees of regeneration by aqueous suspensions of slaked dolomitic lime. These results enable identification of agents having optimal basicity. Among the extractants, the secondary amine Amberlite LA-2 gave the best combined performance for extraction and regeneration. Among the sorbents, a tertiary amine, Amberlite IRA-35, gave the best performance. Trioctylphosphine oxide does not maintain capacity in the pH range (about 6) most attractive for acetic acid fermentation. Slurred crushed dolomite is not sufficiently basic to accomplish regeneration.

Reisinger, H.; King, C.J. [Lawrence Berkeley Lab., CA (United States)

1995-03-01

282

Differential effects of endogenous and synthetic cannabinoids on voltage-dependent calcium fluxes in rabbit T-tubule membranes: comparison with fatty acids.  

PubMed

The effects of cannabinoid receptor ligands including 2-arachidonoylglycerol, R-methanandamide, Delta9-THC (Delta9-tetrahydrocannabinol), WIN 55,212-2 [4,5-dihydro-2-methyl-4(4-morpholinylmethyl)-1-(1-naphthalenylcarbonyl)-6H-pyrrolo[3,2,1ij]quinolin-6-one], CP 55,940 ([1alpha,2beta-(R)-5alpha]-(-)-5-(1,1-dimethyl)-2-[5-hydroxy-2-(3-hydroxypropyl) cyclohexyl-phenol]) and a series of fatty acids on depolarization-induced Ca2+ effluxes mediated by voltage-dependent Ca2+ channels were investigated comparatively in transverse tubule membrane vesicles from rabbit skeletal muscle. Vesicles were loaded with 45Ca2+ and membrane potentials were generated by establishing potassium gradients across the vesicle using the ionophore valinomycin. Endocannabinoids, 2-arachidonoylglycerol and R-methanandamide (all 10 microM), inhibited depolarization-induced Ca2+ effluxes and specific binding of [3H]PN 200-110 (isradipine) to transverse tubule membranes. On the other hand, synthetic cannabinoids, including CP 55,940, WIN 55,212-2, and Delta9-THC (all 10 microM), were ineffective. Additional experiments using endocannabinoid metabolites suggested that whereas ethanolamine and glycerol were ineffective, arachidonic acid inhibited Ca2+ effluxes and specific binding of [3H]PN 200-110. Further studies indicated that only those fatty acids containing two or more double bonds were effective in inhibiting depolarization-induced Ca2+ effluxes and specific binding of [3H]PN 200-110. These results indicate that endocannabinoids, but not synthetic cannabinoids, directly inhibit the function of voltage-dependent calcium channels (VDCCs) and modulate the specific binding of calcium channel ligands of the dihydropyridine (DHP) class. PMID:15464089

Oz, Murat; Tchugunova, Yulia; Dinc, Meral

2004-10-11

283

The effects of ezetimibe on omega-3 fatty acid absorption in the prevention of cardiovascular disease.  

E-print Network

??Omega-3 polyunsaturated fatty acids like alpha-linolenic acid (ALA) may be beneficial for cardiovascular health. A cholesterol supplemented diet will increase ALA bioavailability. Conversely, drugs which… (more)

Blackwood, David Palmer

2012-01-01

284

Evaluation of Preventive and Control Measures for Lead Exposure in a South African Lead-Acid Battery Recycling Smelter  

Microsoft Academic Search

In South Africa, new lead regulations released in February 2002 served as motivation for a cross-sectional study investigating the effectiveness of preventive and control measures implemented in a lead smelter that recycles lead-acid batteries. Twenty-two workers were observed and interviewed. Structured questionnaires were used to gather workers' personal information, perception about their work environment, health risks, and work practices. Retrospective

Sindiswa Dyosi

2007-01-01

285

Physicochemical changes in Mazafati date fruits incubated in hot acetic acid for accelerated ripening to prevent diseases and decay  

Microsoft Academic Search

A method was developed and optimized for the accelerated ripening of date fruits of cultivar ‘Mazafati’ to prevent diseases and decay. The date fruits were incubated in hot acetic acid solution 0.5% at 40+1°C for 72h. During the process some physicochemical changes in the fruits were studied and were found to be comparable with the changes in the fruits that

Asgar Farahnaky; Hassan Afshari-Jouybari

2011-01-01

286

Prevention of Retrosternal Adhesion Formation in a Rabbit Model Using Bioresorbable Films of Polyethylene Glycol and Polylactic Acid  

Microsoft Academic Search

The purpose of this study was to test the efficacy of three bioresorbable films of polyethylene glycol (EO) and polylactic acid (LA) (EO\\/LA = 1.5, 2.5, and 3.0) in the prevention of adhesion formation between the epicardium and the sternum (retrosternal adhesions) in a rabbit model. Retrosternal adhesions were generated by sternotomy, pericardiotomy, and abrasion of the anterior epicardium. The

Naoki Okuyama; Kathleen E. Rodgers; Catherine Y. Wang; Wefki Girgis; Mehmet Oz; Karen St. Amand; Eli Pines; Alexander H. DeCherney; Eric A. Rose; Daniel Cohn; Gere S. diZerega

1998-01-01

287

Olive Oil Prevents the Adverse Effects of Dietary Conjugated Linoleic Acid on Chick Hatchability and Egg Quality1  

Microsoft Academic Search

Dietary conjugated linoleic acid (CLA) decreases yolk 18:1(n-9), induces chick embryonic mortality and alters egg quality. A study was conducted to determine whether olive oil would prevent these adverse effects of CLA. Hens (15 per treatment) were fed diets containing 0.5 g corn oil\\/100 g (CO), 0.5 g CLA\\/100 g (CLA), 0.5 g corn oil plus 10 g olive oil\\/100

Rahim Aydin; Michael W. Pariza; Mark E. Cook

288

Palmitoleic acid prevents palmitic acid-induced macrophage activation and consequent p38 MAPK-mediated skeletal muscle insulin resistance  

PubMed Central

Obesity and saturated fatty acid (SFA) treatment are both associated with skeletal muscle insulin resistance (IR) and increased macrophage infiltration. However, the relative effects of SFA and unsaturated fatty acid (UFA)-activated macrophages on muscle are unknown. Here, macrophages were treated with palmitic acid, palmitoleic acid or both and the effects of the conditioned medium (CM) on C2C12 myotubes investigated. CM from palmitic acid-treated J774s (palm-mac-CM) impaired insulin signalling and insulin-stimulated glycogen synthesis, reduced Inhibitor ?B? and increased phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase in myotubes. p38 MAPK inhibition or siRNA partially ameliorated these defects, as did addition of tumour necrosis factor-? blocking antibody to the CM. Macrophages incubated with both FAs generated CM that did not induce IR, while palmitoleic acid-mac-CM alone was insulin sensitising. Thus UFAs may improve muscle insulin sensitivity and counteract SFA-mediated IR through an effect on macrophage activation. PMID:24973767

Talbot, Nicola A.; Wheeler-Jones, Caroline P.; Cleasby, Mark E.

2014-01-01

289

Ca 2+ channel blockade prevents lysergic acid diethylamide-induced changes in dopamine and serotonin metabolism  

Microsoft Academic Search

To investigate the effect of a single and multiple administration of lysergic acid diethylamide (LSD) on cerebral metabolism of dopamine and serotonin, male Wistar rats were treated with low and high doses (0.1 and 2.0 mg\\/kg i.p.) of LSD and the levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, 3-methoxytyramine, serotonin and 5-hydroxyindoleacetic acid were assayed by HPLC in the nucleus

Lucyna Antkiewicz-Michaluk; Irena Roma?ska; Jerzy Vetulani

1997-01-01

290

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

Microsoft Academic Search

Chronic exposure to elevated free fatty acids, in particular long chain saturated fatty acids, provokes endoplasmic reticulum\\u000a (ER) stress and cell death in a number of cell types. The perturbations to the ER that instigate ER stress and activation\\u000a of the unfolded protein in response to fatty acids in hepatocytes have not been identified. The present study employed H4IIE\\u000a liver

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

2009-01-01

291

Benzodiazepine-induced hippocampal CA1 neuron alpha-amino-3-hydroxy-5-methylisoxasole-4-propionic acid (AMPA) receptor plasticity linked to severity of withdrawal anxiety: differential role of voltage-gated calcium channels and N-methyl-D-aspartic acid receptors.  

PubMed

Withdrawal from 1-week oral administration of the benzodiazepine, flurazepam (FZP) is associated with increased alpha-amino-3-hydroxy-5-methylisoxasole-4-propionic acid (AMPA) receptor (AMPAR) miniature excitatory postsynaptic currents (mEPSCs) but reduction of N-methyl-D-aspartic acid (NMDA) receptor (NMDAR)-evoked (e)EPSCs in hippocampal CA1 neurons. A positive correlation was observed between increased AMPAR-mediated mEPSC amplitude and anxiety-like behavior in 1-day FZP-withdrawn rats. These effects were disrupted by systemic AMPAR antagonist administration (GYKI-52466, 0.5 mg/kg, intraperitoneal) at withdrawal onset, strengthening the hypothesis that CA1 neuron AMPAR-mediated hyperexcitability is a central component of a functional anatomic circuit associated with the expression of withdrawal anxiety. Abolition of AMPAR current upregulation in 2-day FZP withdrawn rats by GYKI-52466 injection also reversed the reduction in NMDAR-mediated eEPSC amplitude in CA1 neurons from the same rats, suggesting that downregulation of NMDAR function may serve a protective, negative-feedback role to prevent AMPAR-mediated neuronal overexcitation. NMDAR antagonist administration (MK-801, 0.25 mg/kg intraperitoneally) had no effect on modifying increased glutamatergic strength or on withdrawal anxiety, whereas injection of an L-type voltage-gated calcium channel antagonist, nimodipine (10 mg/kg, intraperitoneally) averted AMPAR current enhancement and anxiety-like behavior, suggesting that these manifestations may be initiated by a voltage-gated calcium channel-dependent signal transduction pathway. An evidence-based model of likely cellular mechanisms in the hippocampus contributing to benzodiazepine withdrawal anxiety was proposed implicating regulation of multiple CA1 neuron ion channels. PMID:17762513

Xiang, Kun; Tietz, Elizabeth I

2007-09-01

292

Effect of Calcium Soap of Fatty Acids Supplementation on Serum Biochemical Parameters and Ovarian Activity during Out-of-the-Breeding Season in Crossbred Ewes  

PubMed Central

This experiment aimed to evaluate the effect of calcium soap of fatty acid (CSFA) supplementation on serum biochemical and hormones and ovarian activity during out-of-the-breeding season in ewes. Twelve crossbred ewes, 2-3 years of age and weighting 45–55?kg, were allocated into two equal groups. The first group was control and the other was treated with 50?g/head of CSFA. All ewes were fed basal diet and treated with 60?mg of medroxy progesterone acetate intravaginal sponge for 12 day. At the third day of sponge removal, the CSFA-treated group was given 50?g/head of CSFA daily for two estrous cycles. During the estrus phase, ovarian activity was detected using ultrasonography in both groups. All ewes were then subjected to natural breeding and conception rate. Blood samples were collected from all ewes during treatment period. Results revealed significant (P < 0.05) increases in serum cholesterol, triglycerides, low-density lipoprotein cholesterol, glucose, and progesterone levels with decrease in calcium and phosphorous levels in treated group. In treated group, normal-size ovaries and more than one follicle on the ovaries were detected and pregnancy rate increased. In conclusion, CSFA supplementation was effective to maintain the reproductive performance when ewes were out of the breeding season. PMID:22629155

El-Nour, Hayat H. M.; Nasr, Soad M.; Hassan, Walid R.

2012-01-01

293

Calcium channel blockers and dementia  

PubMed Central

Degenerative dementia is mainly caused by Alzheimer's disease and/or cerebrovascular abnormalities. Disturbance of the intracellular calcium homeostasis is central to the pathophysiology of neurodegeneration. In Alzheimer's disease, enhanced calcium load may be brought about by extracellular accumulation of amyloid-?. Recent studies suggest that soluble forms facilitate influx through calcium-conducting ion channels in the plasma membrane, leading to excitotoxic neurodegeneration. Calcium channel blockade attenuates amyloid-?-induced neuronal decline in vitro and is neuroprotective in animal models. Vascular dementia, on the other hand, is caused by cerebral hypoperfusion and may benefit from calcium channel blockade due to relaxation of the cerebral vasculature. Several calcium channel blockers have been tested in clinical trials of dementia and the outcome is heterogeneous. Nimodipine as well as nilvadipine prevent cognitive decline in some trials, whereas other calcium channel blockers failed. In trials with a positive outcome, BP reduction did not seem to play a role in preventing dementia, indicating a direct protecting effect on neurons. An optimization of calcium channel blockers for the treatment of dementia may involve an increase of selectivity for presynaptic calcium channels and an improvement of the affinity to the inactivated state. Novel low molecular weight compounds suitable for proof-of-concept studies are now available. PMID:23638877

Nimmrich, V; Eckert, A

2013-01-01

294

Lipopolysaccharide prevents valproic acid-induced apoptosis via activation of nuclear factor-?B and inhibition of p53 activation.  

PubMed

The effect of lipopolysaccharide (LPS) on valproic acid (VPA)-induced cell death was examined by using mouse RAW 264.7 macrophage cells. LPS inhibited the activation of caspase 3 and poly (ADP-ribose) polymerase and prevented VPA-induced apoptosis. LPS inhibited VPA-induced p53 activation and pifithrin-? as a p53 inhibitor as well as LPS prevented VPA-induced apoptosis. LPS abolished the increase of Bax/Bcl-2 ratio, which is a critical indicator of p53-mediated mitochondrial damage, in response to VPA. The nuclear factor (NF)-?B inhibitors, Bay 11-7082 and parthenolide, abolished the preventive action of LPS on VPA-induced apoptosis. A series of toll-like receptor ligands, Pam3CSK4, poly I:C, and CpG DNA as well as LPS prevented VPA-induced apoptosis. Taken together, LPS was suggested to prevent VPA-induced apoptosis via activation of anti-apoptotic NF-?B and inhibition of pro-apoptotic p53 activation. The detailed inhibitory mechanism of VPA-induced apoptosis by LPS is discussed. PMID:23770718

Tsolmongyn, Bilegtsaikhan; Koide, Naoki; Odkhuu, Erdenezaya; Haque, Abedul; Naiki, Yoshikazu; Komatsu, Takayuki; Yoshida, Tomoaki; Yokochi, Takashi

2013-04-01

295

Influence of diet transition on serum calcium and phosphorus and fatty acids in zoo giraffe (Giraffa camelopardalis).  

PubMed

In response to new recommendations for feeding giraffe in zoos, giraffe (n = 6) were transitioned from a typical hoofstock diet to diets containing reduced starch, protein, Ca and P and added n3 fatty acids. This diet was fed as a 50:50 mix with alfalfa and grass hay. Over the next 4 years, serum Ca, P, and fatty acids were measured every 6 months (summer and winter). Serum Ca was not affected by season (P = 0.67) or by diet (P = 0.12). Serum P was not affected season (P = 0.14), but was reduced by diet (P<0.01), and serum Ca:P was also increased by diet (P<0.01). The ratio of serum Ca:P tended to be affected by season (P = 0.07), in which animals tended to have greater Ca:P during the summer vs. the winter. The diet transition resulted in reduced serum saturated fatty acids (including lauric, myristic, palmitic, arachidic, and behenic acids), and increases in n6 fatty acids (including linolenic and arachidonic acids) and n3 fatty acids (docosahexaenoic acid) (P<0.05 for each). Overall, this diet transition resulted in blood nutrient profiles that more closely match that of values found in free-ranging giraffe. PMID:20954252

Koutsos, E A; Armstrong, D; Ball, R; Dikeman, C; Hetherington, J; Simmons, L; Valdes, E V; Griffin, M

2011-01-01

296

[Microbial geochemical calcium cycle].  

PubMed

The participation of microorganisms in the geochemical calcium cycle is the most important factor maintaining neutral conditions on the Earth. This cycle has profound influence on the fate of inorganic carbon, and, thereby, on the removal of CO2 from the atmosphere. The major part of calcium deposits was formed in the Precambrian, when prokaryotic biosphere predominated. After that, calcium recycling based on biogenic deposition by skeletal organisms became the main process. Among prokaryotes, only a few representatives, e.g., cyanobacteria, exhibit a special calcium function. The geochemical calcium cycle is made possible by the universal features of bacteria involved in biologically mediated reactions and is determined by the activities of microbial communities. In the prokaryotic system, the calcium cycle begins with the leaching of igneous rock predominantly through the action of the community of organotrophic organisms. The release of carbon dioxide to the soil air by organotrophic aerobes leads to leaching with carbonic acid and soda salinization. Under anoxic conditions, of major importance is the organic acid production by primary anaerobes (fermentative microorganisms). Calcium carbonate is precipitated by secondary anaerobes (sulfate reducers) and to a smaller degree by methanogens. The role of the cyanobacterial community in carbonate deposition is exposed by stromatolites, which are the most common organo-sedimentary Precambrian structures. Deposition of carbonates in cyanobacterial mats as a consequence of photoassimilation of CO2 does not appear to be a significant process. It is argued that carbonates were deposited at the boundary between the "soda continent", which emerged as a result of subaerial leaching with carbonic acid, and the ocean containing Ca2+. Such ecotones provided favorable conditions for the development of the benthic cyanobacterial community, which was a precursor of stromatolites. PMID:11910807

Zavarzin, G A

2002-01-01

297

Activation of Retinoid X Receptors by Phytanic Acid and Docohexaenoic Acid: Role in the Prevention and Therapy of Prostate Cancer.  

National Technical Information Service (NTIS)

In this study we investigated the effects of these two dietary RXR ligands (agonists) on the cell growth and retinoid metabolism of cultured human prostate cancer cell lines. Retinoic acid (RA) treatment for 72 hours and 120 hours did not have a significa...

X. Tang

2005-01-01

298

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

USGS Publications Warehouse

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

Sparling, D.W.

1990-01-01

299

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

PubMed

In areas impacted by acid precipitation, water chemistry of acidic ponds and streams often changes, resulting in increased mobilization of aluminum and decreased concentration of calcium carbonate. Aluminum binds with phosphorus and inhibits its uptake by organisms. Thus, invertebrate food organisms used by waterfowl may have inadequate Ca and P or elevated Al for normal growth and development. Acid rain and its effects may be one of the factors negatively impacting American black ducks (Anas rubripes) in eastern North America. One-day old mallards (A. platyrhynchos) and black ducks were placed on one of three Ca:P regimens: low:low (LL), normal:normal (NN), and low:high (LH) with each regimen divided further into three or four Al levels for 10 weeks. Forty-five % of the black ducks died on nine different diets whereas only 28% of the mallards died on three different diets. Mortality was significantly related to diet in both species. Growth rates for body weight, culmens, wings, and tarsi of both species on control diets exceeded those on many treatment diets but the differences were less apparent for mallards than for black ducks. Differences among treatments were due to both Ca:P and Al levels. PMID:2353844

Sparling, D W

1990-01-01

300

Economic burden of neural tube defects and impact of prevention with folic acid: a literature review  

Microsoft Academic Search

Neural tube defects (NTDs) are the second most common group of serious birth defects. Although folic acid has been shown to\\u000a reduce effectively the risk of NTDs and measures have been taken to increase the awareness, knowledge, and consumption of\\u000a folic acid, the full potential of folic acid to reduce the risk of NTDs has not been realized in most

Yunni Yi; Marion Lindemann; Antje Colligs; Claire Snowball

301

Aspirin prevents wound-induced gene expression in tomato leaves by blocking jasmonic acid biosynthesis  

Microsoft Academic Search

Jasmonic acid (JA) and its methyl ester, like mechanical wounding, strongly induce accumulation of proteinase inhibitor II (Pin2) in tomato and potato leaves. In plants, JA is synthesized from a-linolenic acid by a lipoxygenase (LOX)-mediated oxygenation leading to 13-hydroxyperoxylinolenic acid (13-HPLA) which is then subsequently transformed to JA by the action of hydroperoxide-dehydrase activity and additional modification steps. Both the

Hugo Pena-Cortés; Tanja Albrecht; Salomé Prat; Elmar W. Weiler; Lothar Willmitzer

1993-01-01

302

Dipicolinic acid prevents the copper-dependent oxidation of low density lipoprotein  

Microsoft Academic Search

Effect of dipicolinic acid (pyridine 2,6-dicarboxylic acid) and pyridine compounds on the copper-dependent oxidation of human low density lipoprotein was analyzed in relation to the inhibition of copper reduction. Dipicolinic acid inhibited copper-dependent LDL oxidation completely, but the LDL oxidation was slightly inhibited by pyridine compounds with one carboxyl group at 2 or 6-position. Reduction of copper by LDL itself

Keiko Murakami; Yasuko Tanemura; Masataka Yoshino

2003-01-01

303

[Conjugated linoleic acid as a potential protective factor in prevention of breast cancer].  

PubMed

Cancers are the second leading cause of deaths in Poland, among both women and men. Breast cancer is the malignancy most frequently diagnosed in women. In 2008 mammary cancer was diagnosed in up to 14 500 patients. It is also the second most common cause of cancer deaths among women in our country. Although the etiology of most cases of this disease is not known, risk factors include a variety of nutritional factors. The amount of fat consumed in the diet and the quantity and quality of fatty acids are especially crucial. Among fatty acids to which great importance in modification of cancer risk is attributed are conjugated linoleic acid. Conjugated linoleic acids (CLA) are a group of positional and geometric isomers of linoleic acid, with a conjugated double bond system in the carbon chain. The main natural source of them is milk and dairy products and meat of different species of ruminants, in which cis-9, trans-11 octadecadienoic acid (rumenic acid) occurs in the largest quantities, constituting over 90% of the total pool of CLA. Another important isomer is trans-10, cis-12 octadecadienoic acid, which occurs with rumenic acid in dietary supplements, usually in the ratio 1:1. Surveys conducted show their possible health promoting effects in obesity, atherosclerosis, cardiovascular diseases, osteoporosis, diabetes, insulin resistance, inflammation, and various types of cancer, especially breast cancer.  PMID:23475478

Bia?ek, Agnieszka; Tokarz, Andrzej

2013-01-01

304

Relative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate  

E-print Network

of calcium from calcium formate, a new experimental dietary calcium supplement, to that of calcium citrate and calcium carbonate. In a four-way crossover study, either a placebo or 1200 mg of calcium as calcium carbonate, calcium citrate, or calcium formate...

Hanzlik, Robert P.; Fowler, S. C.; Fisher, D. H.

2005-06-01

305

Treatment and prevention systems for acid mine drainage and halogenated contaminants  

DOEpatents

Embodiments include treatments for acid mine drainage generation sources (10 perhaps by injection of at least one substrate (11) and biologically constructing a protective biofilm (13) on acid mine drainage generation source materials (14). Further embodiments include treatments for degradation of contaminated water environments (17) with substrates such as returned milk and the like.

Jin, Song (Fort Collins, CO); Fallgren, Paul H. (Laramie, WY); Morris, Jeffrey M. (Laramie, WY)

2012-01-31

306

Optical sensors for evaluating environmental acidity in the preventive conservation of historical objects  

Microsoft Academic Search

Since their creation, appearing or recovering, historical objects are sensitive to environmental corrosion. Although the pollutants level is nowadays strictly controlled, new pollutants appear every year both indoor and outdoor the buildings, due to the industrial development. The increasing environmental acidity and the risk of acid rain under highly polluted and humid areas are one of the most dangerous chemical

N. Carmona; M. A. Villegas; J. M. Fernández Navarro

2004-01-01

307

Prevention of bleeding after cardiopulmonary bypass with high-dose tranexamic acid  

Microsoft Academic Search

This prospective, double-blind, randomized trial assessed the effectiveness of high-dose tranexamic acid given in the preoperative period on blood loss in patients undergoing cardiopulmonary bypass. One hundred fifty patients scheduled to undergo cardiac operations with cardiopulmonary bypass were randomized into three groups of equal size. The first group received 10 gm of tranexamic acid intravenously over 20 minutes before sternotomy

Jacek M. Karski; Sally J. Teasdale; Peter Norman; Jo Carroll; Karl VanKessel; Peter Wong; M. F. X. Glynn

1995-01-01

308

Continuous Production of Lactic Acid from Whey Perméate by Free and Calcium Alginate Entrapped Lactobacillus helveticus1  

Microsoft Academic Search

Lactobacillus belveticus strain milano was used for the continuous fermentation of lactic acid in cheese whey-yeast extract permeate medium. The best productivity of lactic acid was with the free cell system, which was 9.7 g\\/L per h at a dilution rate of .352 h -1. Under such conditions, lactose conversion was 87.5%, based on the lactose concentration of 37.4 g\\/L

Denis Roy; Jacques Goulet; Anh Le Duy

1987-01-01

309

Influences of humic acid, bicarbonate and calcium on Cr(VI) reductive removal by zero-valent iron.  

PubMed

The influences of various geochemical constituents, such as humic acid, HCO(3)(-), and Ca(2+), on Cr(VI) removal by zero-valent iron (Fe(0)) were investigated in a batch setting. The collective impacts of humic acid, HCO(3)(-), and Ca(2+) on the Cr(VI) reduction process by Fe(0) appeared to significantly differ from their individual impacts. Humic acid introduced a marginal influence on Fe(0) reactivity toward Cr(VI) reduction, whereas HCO(3)(-) greatly enhanced Cr(VI) removal by maintaining the solution pH near neutral. The Cr(VI) reduction rate constants (k(obs)) were increased by 37.8% and 78.3%, respectively, with 2 mM and 6 mM HCO(3)(-) in solutions where humic acid and Ca(2+) were absent. Singly present Ca(2+) did not show a significant impact to Cr(VI) reduction. However, probably due to the formation of passivating CaCO(3), further addition of Ca(2+) to HCO(3)(-) containing solutions resulted in a decrease of k(obs) compared to solutions containing HCO(3)(-) alone. Ca(2+) enhanced humic acid adsorption led to a minor decrease of Cr(VI) reduction rates. In Ca(2+)-free solutions, humic acid increased the amount of total dissolved iron to 25 mg/l due to the formation of soluble Fe-humate complexes and stably dispersed fine Fe (oxy)hydroxide colloids, which appeared to suppress iron precipitation. In contrast, the coexistence of humic acid and Ca(2+) significantly promoted the aggregation of Fe (oxy)hydroxides, with which humic acid co-aggregated and co-precipitated. These aggregates would progressively be deposited on Fe(0) surfaces and impose long-term impacts on the permeability of PRBs. PMID:19232679

Liu, Tongzhou; Rao, Pinhua; Lo, Irene M C

2009-05-01

310

Preventive effect of ?-lipoic acid on prepulse inhibition deficits in a juvenile two-hit model of schizophrenia.  

PubMed

Some pathophysiological models of schizophrenia posit that prenatal inflammation sensitizes the developing brain to second insults in early life and enhances brain vulnerability, thereby increasing the risk of developing the disorder during adulthood. We previously developed a two-hit animal model, based on the well-established prenatal immune challenge with poly-inosinic/cytidylic acid (polyI:C), followed by juvenile restraint stress (RS). We observed an additive disruption of prepulse inhibition (PPI) of acoustic startle in juvenile mice submitted to both insults. Previous studies have also reported that oxidative stress is associated with pathophysiological mechanisms of psychiatric disorders, including schizophrenia. We report here that PPI disruption in our two-hit animal model of schizophrenia is associated with an increase in oxidative stress. These findings led us to assess whether ?-lipoic acid, an antioxidant, can prevent both increase in oxidative status and PPI deficits in our juvenile in vivo model of schizophrenia. In the offspring submitted to prenatal injection of polyI:C and to RS, treatment with ?-lipoic acid prevented the development of PPI deficits 24h after the last period of RS. ?-Lipoic acid also improved PPI performance in control mice. The reversal effect of ?-lipoic acid pretreatment on these behavioral alterations was further accompanied by a normalization of the associated oxidative status and dopaminergic and GABAergic abnormalities in the prefrontal cortex. Based on our double insult paradigm, these results support the hypothesis that oxidative stress plays an important role in the development of PPI deficits, a well-known behavior associated with schizophrenia. These findings form the basis of future studies aiming to unravel mechanistic insights of the putative role of antioxidants in the treatment of schizophrenia, especially during the prodromal stage. PMID:24813434

Deslauriers, J; Racine, W; Sarret, P; Grignon, S

2014-07-11

311

Effect of sodium gluconate on the solubility of calcium lactate  

Microsoft Academic Search

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

C. Phadungath; L. E. Metzger

2011-01-01

312

Multiple Calcium Stores: Separate but Interacting  

NSDL National Science Digital Library

Multiple mechanisms exist for increasing the concentration of intracellular calcium. This Perspective by Lee is one in a series on intracellular calcium release mechanisms and focuses on the calcium store operated by nicotinic acid adenine dinucleotide phosphate (NAADP). The characterization of the NAADP-operated calcium store as separate from the inositol trisphosphate (IP3)-operated and cyclic ADP-ribose (cADPR)-operated calcium stores is discussed. Lee also addresses the role of NAADP in regulating intracellular calcium fluctuations during fertilization and hormonal activation of pancreatic acinar cells.

Hon Cheung Lee (University of Minnesota;Department of Pharmacology REV)

2000-07-11

313

Attenuation of endoplasmic reticulum stress using the chemical chaperone 4-phenylbutyric acid prevents cardiac fibrosis induced by isoproterenol.  

PubMed

Increasing evidence indicates that endoplasmic reticulum (ER) stress is involved in various diseases. In the human heart, ischemia/reperfusion has been correlated to ER stress, and several markers of the unfolded protein response (UPR) participate during cardiac remodeling and fibrosis. Here, we used isoproterenol (ISO) injection as a model for in vivo cardiac fibrosis. ISO induced significant cardiomyocyte loss and collagen deposition in the damaged areas of the endocardium. These responses were accompanied by an increase in the protein levels of the luminal ER chaperones BIP and PDI, as well as an increase in the UPR effector CHOP. The use of the chemical chaperone 4-phenylbutyric acid (4-PBA) prevented the activation of the UPR, the increase in luminal chaperones and also, leads to decreased collagen deposition, cardiomyocyte loss into the damaged zones. Our results suggest that cardiac damage and fibrosis induced in vivo by the beta-adrenergic agonist ISO are tightly related to ER stress signaling pathways, and that increasing the ER luminal folding capacity with exogenously administrated 4-PBA is a powerful strategy for preventing the development of cardiac fibrosis. Additionally, 4-PBA might prevent the loss of cardiomyocytes. Our data suggests that the attenuation of ER stress pathways with pharmacological compounds such as the chemical chaperone 4-PBA can prevent the development of cardiac fibrosis and adverse remodeling. PMID:22101259

Ayala, Pedro; Montenegro, José; Vivar, Raúl; Letelier, Alan; Urroz, Pablo Aránguiz; Copaja, Miguel; Pivet, Deisy; Humeres, Claudio; Troncoso, Rodrigo; Vicencio, José Miguel; Lavandero, Sergio; Díaz-Araya, Guillermo

2012-02-01

314

Disturbed brain phospholipid and docosahexaenoic acid metabolism in calcium-independent phospholipase A2-VIA (iPLA2?)-knockout mice  

PubMed Central

Calcium-independent phospholipase A2 group VIA (iPLA2?) releases docosahexaenoic acid (DHA) from phospholipids in vitro. Mutations in the iPLA2? gene, PLA2G6, are associated with dystonia-parkinsonism and infantile neuroaxonal dystrophy. To understand the role of iPLA2? in brain, we applied our in vivo kinetic method using radiolabeled DHA in 4 to 5-month-old wild type (iPLA2?+/+) and knockout (iPLA2??/?) mice, and measured brain DHA kinetics, lipid concentrations, and expression of PLA2, cyclooxygenase (COX), and lipoxygenase (LOX) enzymes. Compared to iPLA2?+/+ mice, iPLA2??/? mice showed decreased rates of incorporation of unesterified DHA in plasma into brain phospholipids, reduced concentration of several fatty acid residues (including DHA) esterified in ethanolamine- and serine-glycerophospholipids, and increased lysophospholipid fatty acid concentrations. DHA turnover rates in brain phospholipids did not differ between genotypes. In iPLA2??/? mice, brain levels of iPLA2? mRNA, protein, and activity were decreased, as was the iPLA2? (Group VIB PLA2) mRNA level. Brain levels of secretory sPLA2-V mRNA, protein, and activity and cytosolic cPLA2-IVA mRNA were increased in iPLA2??/? mice. Levels of COX-1 protein were decreased in brain, while COX-2 protein and mRNA were increased. Levels of 5-, 12-, and 15-LOX proteins did not differ significantly between genotypes. Thus, genetic iPLA2? deficiency in mice is associated with profound reorganization of lipid-metabolizing enzyme expression and of phospholipid fatty acid content of brain (particularly of DHA), which may be relevant to the neurologic abnormalities in humans with iPLA2? mutations. PMID:22349267

Cheon, Yewon; Kim, Hyung-Wook; Igarashi, Miki; Modi, Hiren R.; Chang, Lisa; Ma, Kaizong; Greenstein, Deanna; Wohltmann, Mary; Turk, John; Rapoport, Stanley I; Taha, Ameer Y.

2012-01-01

315

Disturbed brain phospholipid and docosahexaenoic acid metabolism in calcium-independent phospholipase A(2)-VIA (iPLA(2)?)-knockout mice.  

PubMed

Calcium-independent phospholipase A(2) group VIA (iPLA(2)?) releases docosahexaenoic acid (DHA) from phospholipids in vitro. Mutations in the iPLA(2)? gene, PLA2G6, are associated with dystonia-parkinsonism and infantile neuroaxonal dystrophy. To understand the role of iPLA(2)? in brain, we applied our in vivo kinetic method using radiolabeled DHA in 4 to 5-month-old wild type (iPLA(2)?(+/+)) and knockout (iPLA(2)?(-/-)) mice, and measured brain DHA kinetics, lipid concentrations, and expression of PLA(2), cyclooxygenase (COX), and lipoxygenase (LOX) enzymes. Compared to iPLA(2)?(+/+) mice, iPLA(2)?(-/-) mice showed decreased rates of incorporation of unesterified DHA from plasma into brain phospholipids, reduced concentrations of several fatty acids (including DHA) esterified in ethanolamine- and serine-glycerophospholipids, and increased lysophospholipid fatty acid concentrations. DHA turnover in brain phospholipids did not differ between genotypes. In iPLA(2)?(-/-) mice, brain levels of iPLA(2)? mRNA, protein, and activity were decreased, as was the iPLA(2)? (Group VIB PLA(2)) mRNA level, while levels of secretory sPLA(2)-V mRNA, protein, and activity and cytosolic cPLA(2)-IVA mRNA were increased. Levels of COX-1 protein were decreased in brain, while COX-2 protein and mRNA were increased. Levels of 5-, 12-, and 15-LOX proteins did not differ significantly between genotypes. Thus, a genetic iPLA(2)? deficiency in mice is associated with reduced DHA metabolism, profound changes in lipid-metabolizing enzyme expression (demonstrating lack of redundancy) and of phospholipid fatty acid content of brain (particularly of DHA), which may be relevant to neurologic abnormalities in humans with PLA2G6 mutations. PMID:22349267

Cheon, Yewon; Kim, Hyung-Wook; Igarashi, Miki; Modi, Hiren R; Chang, Lisa; Ma, Kaizong; Greenstein, Deanna; Wohltmann, Mary; Turk, John; Rapoport, Stanley I; Taha, Ameer Y

2012-09-01

316

Tuning the Degradation Rate of Calcium Phosphate Cements by Incorporating Mixtures of Polylactic-co-Glycolic Acid Microspheres and Glucono-Delta-Lactone Microparticles.  

PubMed

Calcium phosphate cements (CPCs) are frequently used as synthetic bone graft materials in view of their excellent osteocompatibility and clinical handling behavior. Hydroxyapatite-forming CPCs, however, degrade at very low rates, thereby limiting complete bone regeneration. The current study has investigated whether degradation of apatite-forming cements can be tuned by incorporating acid-producing slow-resorbing poly(D,L-lactic-co-glycolic) acid (PLGA) porogens, fast-resorbing glucono-delta-lactone (GDL) porogens, or mixtures thereof. The physicochemical, mechanical, and degradation characteristics of these CPC formulations were systematically analyzed upon soaking in phosphate-buffered saline (PBS). In parallel, various CPC formulations were implanted intramuscularly and orthotopically on top of the transverse process of goats followed by analysis of the soft tissue response and bone ingrowth after 12 weeks. In vitro degradation of GDL was almost completed after 2 weeks, as evidenced by characterization of the release of gluconic acid, while PLGA-containing CPCs released glycolic acid throughout the entire study (12 weeks), resulting in a decrease in compression strength of CPC. Extensive in vitro degradation of the CPC matrix was observed upon simultaneous incorporation of 30% PLGA-10% GDL. Histomorphometrical evaluation of the intramuscularly implanted samples revealed that all CPCs exhibited degradation, accompanied by an increase in capsule thickness. In the in vivo goat transverse process model, incorporation of 43% PLGA, 30% PLGA-5% GDL, and 30% PLGA-10% GDL in CPC significantly increased bone formation and resulted in higher bone height compared with both 10% GDL and 20% GDL-containing CPC samples. PMID:24819744

Sariibrahimoglu, Kemal; An, Jie; van Oirschot, Bart A J A; Nijhuis, Arnold W G; Eman, Rhandy M; Alblas, Jacqueline; Wolke, Joop G C; van den Beucken, Jeroen J J P; Leeuwenburgh, Sander C G; Jansen, John A

2014-11-01

317

[Prevention and therapeutic effects of sika deer velvet collagen hydrolysate on osteoporosis in rats by retinoic acid].  

PubMed

The objective was to evaluate the preventive and therapeutic effects of the collagen hydrolysate extracted from Sika deer velvet (CSDV) on osteoporosis rats induced by retinoicacid. Histomorphometric indices and serum biochemical parameters were measured in osteoporosis rats treated with/without antler collagen and in sham-operated rats. Our results were as follows: compared with the osteoporosis group, significant elevation in the levels of bone mineral density (BMD), Ca, P and static histomorphometric indexes and biomechanical properties, but reduction in the level of serum alkaline phosphatase (ALP) were observed in antler collagen-treated groups. However, the above function with the collagenase solution velvet material varied with the different doses. In conclusion, the extracted collagen is found to play a role in the prevention and treatment of osteoporosis rats by retinoic acid. PMID:20545204

Li, Yinqing; Zhao, Yu; Sun, Xiaodi; Qu, Xiaobo

2010-03-01

318

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

PubMed Central

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

Ellis, Jessica M.; Wong, G. William

2013-01-01

319

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

PubMed

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

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

2008-08-01

320

Determination of uric acid in urine, saliva and calcium oxalate renal calculi by high-performance liquid chromatography/mass spectrometry.  

PubMed

A very simple and direct method for determination of uric acid, in various biological matrices, based on high-performance liquid chromatography and mass spectrometry is described. Chromatographic separations were performed with a stationary phase Zorbax Sax Column, an anion exchange resin, with 50% sodium citrate 1 mM at pH 6.5 and 50% acetonitrile as mobile phase delivered at a flow rate of 1 ml/min. The detector counted negative ions by monitoring m/z 167.1, which corresponds to the urate anion. The method does not use an internal standard but quality control samples were used. Intra-day precision ranged between 1.1 and 1.5%, whereas inter-day precision was between 1.3 and 2.8% (n=5) working with some selected standards. Recovery tests of added standard have been successfully performed in urine and saliva samples, thus showing an appropriate accuracy of the method. The limit of quantitation found was 70 microg/l. Different urine and saliva samples were analyzed using an alternative analytical methodology based on an enzymatic reaction and photometric detection at 520 nm, resulting both methods comparable at a 95% confidence level. The method has been also applied to the determination of trace amounts of uric acid in the core of some selected calcium oxalate renal calculi. PMID:16061429

Perelló, Joan; Sanchis, Pilar; Grases, Félix

2005-09-25

321

[Prevention of preeclampsia with low-dose acetyl salicylic acid: critical assessment].  

PubMed

The Authors present a critical review of the published literature about the effect of low dose of acido acetilsalicilico on prevention and treatment of preeclampic. Beginning from the effects of low daily dose of acido acetilsalicilico on the pregnancy, the Authors present the published datas from 1970 until today, and suggest the present directions for use of acido acetilsalicilico in pregnancy. PMID:11402808

Verrotti, C; Fieni, S; Gualdi, M; Cavatorta, E

1999-01-01

322

Diabetes-induced alterations in calcium homeostasis in sensory neurones of streptozotocin-diabetic rats are restricted to lumbar ganglia and are prevented by neurotrophin-3  

Microsoft Academic Search

Aims\\/hypothesis. In diabetic sensory polyneuropathy the earliest and most severe pathophysiology occurs in neurones with the longest axons.\\u000a The aim of this study was to characterise a diabetes-induced neurodegenerative marker that was selective for sensory neurones\\u000a with the longest axons. We studied alterations in calcium homeostasis since this occurs in other neurodegenerative diseases.\\u000a Methods. Sensory neurones were cultured from control

T.-J. Huang; N. M. Sayers; P. Fernyhough; A. Verkhratsky

2002-01-01

323

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

NASA Technical Reports Server (NTRS)

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

Bjorkman, T.; Cleland, R. E.

1991-01-01

324

Calcium phosphate deposition rate, structure and osteoconductivity on electrospun poly(l-lactic acid) matrix using electrodeposition or simulated body fluid incubation.  

PubMed

Mineralized nanofibrous scaffolds have been proposed as promising scaffolds for bone regeneration due to their ability to mimic both nanoscale architecture and chemical composition of natural bone extracellular matrix. In this study, a novel electrodeposition method was compared with an extensively explored simulated body fluid (SBF) incubation method in terms of the deposition rate, chemical composition and morphology of calcium phosphate formed on electrospun fibrous thin matrices with a fiber diameter in the range ~200-1400 nm prepared using 6, 8, 10 and 12 wt.% poly(l-lactic acid) (PLLA) solutions in a mixture of dichloromethane and acetone (2:1 in volume). The effects of the surface modification using the two mineralization techniques on osteoblastic cell (MC3T3-E1) proliferation and differentiation were also examined. It was found that electrodeposition was two to three orders of magnitude faster than the SBF method in mineralizing the fibrous matrices, reducing the mineralization time from ~2 weeks to 1h to achieve the same amounts of mineralization. The mineralization rate also varied with the fiber diameter but in opposite directions between the two mineralization methods. As a general trend, the increase of fiber diameter resulted in a faster mineralization rate for the electrodeposition method but a slower mineralization rate for the SBF incubation method. Using the electrodeposition method, one can control the chemical composition and morphology of the calcium phosphate by varying the electric deposition potential and electrolyte temperature to tune the mixture of dicalcium phosphate dihydrate and hydroxyapatite (HAp). Using the SBF method, one can only obtain a low crystallinity HAp. The mineralized electrospun PLLA fibrous matrices from either method similarly facilitate the proliferation and osteogenic differentiation of preosteoblastic MC3T3-E1 cells as compared to neat PLLA matrices. Therefore, the electrodeposition method can be utilized as a fast and versatile technique to fabricate mineralized nanofibrous scaffolds for bone tissue engineering. PMID:24012605

He, Chuanglong; Jin, Xiaobing; Ma, Peter X

2014-01-01

325

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

PubMed

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

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

2014-06-01

326

Investigation, using rat embryo culture, of the role of methionine supply in folic acid-mediated prevention of neural tube defects.  

PubMed

Peri-conceptional folic acid supplementation has become a well established way to prevent neural tube defects (NTDs) and such supplementation reduces the prevalence of these defects by approximately 70%. However, the mechanism of the preventive effect of folic acid is not clear. This overview focuses on the biochemical basis of folic acid-preventable NTDs and on the results obtained with whole embryo culture that may help to shed some light on the mechanisms that underlie the preventive effect of folic acid. Culturing gestational day (GD) 9.5 rat embryos on diet-induced folate-deficient rat serum resulted in many malformations, but no NTDs and this embryotoxicity could only partly be overcome by supplementation with N(5)-methyltetrahydrofolate(5-methylTHF). This indicates that there may be an indirect effect of folate deficiency. Besides an important role in purine and thymidine synthesis, folate drives the methylation cycle in which the methyl group of 5-methylTHF is transferred to numerous biomolecules. In this process homocysteine and methionine are constantly interconverted. It was hypothesized that folate deficiency might lead to a toxic accumulation of homocysteine. However, only homocysteine levels 100-fold higher than physiological levels were embryotoxic to cultured GD10 rat embryos. Moreover, 1 and 2 mm l-homocysteine could prevent NTDs in GD9.5 rat embryos when they were cultured in human serum. Addition of 100 mum methionine had the same preventive effect, but addition of 1 mm folinic acid could not prevent the NTDs. When embryos were cultured in cow or canine serum, methionine had a similar preventive effect. These results suggest folic acid mediated prevention of NTDs may be based on an increase of the methionine supply and possibly its supportive action towards the methylation cycle. PMID:20650144

Vanaerts, L A

1995-10-01

327

Periconceptional folic acid and multivitamin supplementation for the prevention of neural tube defects and other congenital abnormalities.  

PubMed

The pioneering studies of Smithells et al. showed the reduction of recurrent neural-tube defects (NTD) after periconceptional folic acid-containing multivitamin supplementation. The Hungarian Periconceptional Service was established in 1984, and this primary health care system offered a chance to organize a randomized controlled trial to check whether the supplementation of a multivitamin containing 0.8 mg of folic acid during the periconceptional period is appropriate for the reduction of a first occurrence of NTD in the family. This found a reduction of approximately 90% of primary NTD. An unexpected finding was a significant reduction in the rate of congenital abnormalities overall: 20.6 per 1000 in the 'multivitamin' group, and 40.6 per 1000 in the 'trace-element-like' placebo group (RR = 0.53, 95% CI: 0.35-0.70). When the 6 cases of NTD were excluded, this difference in the rates of major congenital abnormalities between the two study-groups remained very highly significant (p < 0.0001). Cardiovascular malformations and urinary tract defects were particularly affected. These findings were confirmed in the Hungarian cohort-controlled trial and by observational studies in other countries. Two questions remain to be answered. Is folic acid better alone or with multivitamins? What is the optimal dose of folic acid? Overall, the Hungarian experiences of periconceptional care have shown not only primary prevention of several severe congenital abnormalities but also a good cost-benefit balance. PMID:19161162

Czeizel, Andrew E

2009-04-01

328

Antioxidant properties of an endogenous thiol: Alpha-lipoic acid, useful in the prevention of cardiovascular diseases.  

PubMed

In the past few years, a growing interest has been given to the possible antioxidant functions of a natural acid, synthesized in human tissues: alpha-lipoic acid (ALA). Both the oxidized (disulfide) and reduced (dithiol: dihydrolipoic acid, DHLA) forms of ALA show antioxidant properties. ALA administered in the diet accumulates in tissues, and a substantial part is converted to DHLA via a lipoamide dehydrogenase. Commercial ALA is usually a racemic mixture of the R and S forms. Chemical studies have indicated that ALA scavenges hydroxyl radicals, hypochlorous acid, and singlet oxygen. ALA exerts antioxidant effects in biological systems not only through direct ROS quenching but also via transition metal chelation. ALA has been shown to possess a number of beneficial effects both in the prevention and treatment of diabetes in experimental conditions. ALA presents beneficial effects in the management of symptomatic diabetic neuropathy and has been used in this context in Germany for more than 30 years. In cardiovascular disease, dietary supplementation with ALA has been successfully employed in a variety of in vivo models: ischemia-reperfusion, heart failure, and hypertension. More mechanistic and human in vivo studies are needed to determine whether optimizing the dietary intake of ALA can help to decrease cardiovascular diseases. A more complete understanding of cellular biochemical events that influence oxidative damage is required to guide future therapeutic advances. PMID:19998523

Ghibu, Stéliana; Richard, Carole; Vergely, Catherine; Zeller, Marianne; Cottin, Yves; Rochette, Luc

2009-11-01

329

Effects of different sources of fat (calcium soap of palm oil vs. extruded linseed) in lactating ewes' diet on the fatty acid profile of their suckling lambs.  

PubMed

The main objective of this study was to evaluate the effects of supplementing lactating ewe diets with extruded linseed on the fatty acid (FA) composition of intramuscular and subcutaneous fat depots of suckling lambs. Twenty-four pregnant Churra ewes were divided into two groups based on the milk production, age, body weight and parity, and assigned to one of two treatments. Each ewe of the Control treatment was supplemented with 70 g/day of FAs from a calcium soap of palm oil, while the other treatment group (Lin) was supplemented with 128 g/day of extruded linseed. All lambs were reared exclusively on milk and were slaughtered when they reached 11 kg live weight. FA profiles of ewe milk, lamb meat and subcutaneous adipose tissue were determined by GC. Lamb performance was not affected by the treatments. Muscle fat and adipose tissue from the Lin treatment showed higher proportions of polyunsaturated fatty acids (PUFA). The percentages of ?-linolenic (C18:3 n-3), docosahexaenoic (C22:6 n-3), vaccenic (trans-11 C18:1) and rumenic (cis-9, trans-11 C18:2) acids in both fat depots were higher in Lin than in Control suckling lambs. Furthermore, meat fat from Lin carcasses displayed a lower n-6/n-3 ratio than Control samples. Intramuscular depots clearly showed a greater content of PUFA, including cis-9, trans-11 C18:2, and a lower n-6/n-3 ratio than subcutaneous fat. The results from this study demonstrate that dietary extruded linseed supplementation of lactating ewes enhances the nutritional quality of suckling lamb fat depots such as intramuscular and subcutaneous fats. PMID:24334053

Gómez-Cortés, P; Gallardo, B; Mantecón, A R; Juárez, M; de la Fuente, M A; Manso, T

2014-03-01

330

Silencing Nicotiana attenuata calcium-dependent protein kinases, CDPK4 and CDPK5, strongly up-regulates wound- and herbivory-induced jasmonic acid accumulations.  

PubMed

The plant hormone jasmonic acid (JA) plays a pivotal role in plant-insect interactions. Herbivore attack usually elicits dramatic increases in JA concentrations, which in turn activate the accumulation of metabolites that function as defenses against herbivores. Although almost all enzymes involved in the biosynthesis pathway of JA have been identified and characterized, the mechanism by which plants regulate JA biosynthesis remains unclear. Calcium-dependent protein kinases (CDPKs) are plant-specific proteins that sense changes in [Ca(2+)] to activate downstream responses. We created transgenic Nicotiana attenuata plants, in which two CDPKs, NaCDPK4 and NaCDPK5, were simultaneously silenced (IRcdpk4/5 plants). IRcdpk4/5 plants were stunted and aborted most of their flower primordia. Importantly, after wounding or simulated herbivory, IRcdpk4/5 plants accumulated exceptionally high JA levels. When NaCDPK4 and NaCDPK5 were silenced individually, neither stunted growth nor high JA levels were observed, suggesting that NaCDPK4 and NaCDPK5 have redundant roles. Attack from Manduca sexta larvae on IRcdpk4/5 plants induced high levels of defense metabolites that slowed M. sexta growth. We found that NaCDPK4 and NaCDPK5 affect plant resistance against insects in a JA- and JA-signaling-dependent manner. Furthermore, IRcdpk4/5 plants showed overactivation of salicylic-acid-induced protein kinase, a mitogen-activated protein kinase involved in various stress responses, and genetic analysis indicated that the increased salicylic-acid-induced protein kinase activity in IRcdpk4/5 plants was a consequence of the exceptionally high JA levels and was dependent on CORONATINE INSENSITIVE1. This work reveals the critical roles of CDPKs in modulating JA homeostasis and highlights the complex duet between JA and mitogen-activated protein kinase signaling. PMID:22715110

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

2012-08-01

331

Effects of Feeding Propionate and Calcium Salts of Long-Chain Fatty Acids on Transition Dairy Cow Performance  

Microsoft Academic Search

Multiparous Holstein cows (n = 40) were used in a randomized complete block design to determine the ef- fects of feeding Ca and Na salts (1:1, wt\\/wt) of propio- nate and Ca salts of long-chain fatty acids (LCFA) on transition cow performance. All cows were fed the same basal diet once daily for ad libitum intake. Treatments (g\\/d) were 320

J. M. DeFrain; A. R. Hippen; K. F. Kalscheur; R. S. Patton

2005-01-01

332

Dairy foods and prevention of colon cancer: human studies.  

PubMed

Colon cancer is the commonest gastrointestinal cancer and the second leading cause of cancer deaths in the United States. Recent approaches to lowering the incidence of colon cancer have included attempts at dietary prevention and chemoprevention. International and national incidence rates for colon cancer suggest an inverse relationship with dietary calcium and/or vitamin D intake (or sun exposure). Several human intervention studies have suggested that supplemental calcium administration will change proliferative indices of risk for colon cancer from high to lower risk patterns. The principal current hypothesis for the action of calcium implies that calcium may precipitate or bring out of solution fatty acids and bile acids that are potentially toxic to the colorectal epithelium. Both calcium administration and dairy food administration are associated with lowering aqueous fecal concentrations of bile acids and fatty acids accompanied by a highly significant lowering of cytotoxicity in studies in vitro. There is biochemical and biological evidence in cell culture systems that exposure to calcium and/or vitamin D reduces the oncogenic properties of colon cancer cells. A recent blinded study of the administration of low-fat dairy foods demonstrated a significant improvement in several parameters of proliferation as well as in two differentiation markers from a high to a lower risk pattern. Furthermore, administration of calcium also has been shown to reduce the incidence of recurrent adenomatous polyps in individuals at increased risk for colon polyp formation because of the presence of prior colon adenomata. These combined data suggest that administration of supplemental calcium or low-fat dairy foods may have a significant effect upon colonic polyp and perhaps colon cancer incidence. PMID:10511318

Holt, P R

1999-10-01

333

PREVENTION POSSIBILITIES OF STRESS CORROSION CRACKING OF MONEL 400 IN HYDROFLUORIC ACID  

Microsoft Academic Search

Stress corrosion cracking (SCC) of Monel 400 in hydrofluoric acid vapour has been investigated by slow strain rate testing. The effect of grain size, cold work and galvanic coupling has been studied. The as-received hot rolled material has shown intergranular cracking, the 50% cold worked material transgranular cracking with decreased susceptibility and the 60% material immunity to SCC. A decrease

R. Kumar; U. K. Chatterjee

334

PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS  

EPA Science Inventory

Exposed, open pit mine highwalls contribute significantly to the production of acid mine drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

335

The role of omega-3 fatty acids in the secondary prevention of cardiovascular disease  

Microsoft Academic Search

Summary It has long been recognized from epidemiological studies that Greenland Eskimos have substantially reduced rates of acute myocardial infarction (MI) compared with Western controls. From these epidemiological observations, the benefits of fatty fish consumption have been explored in cell culture and animal studies, as well as randomized con- trolled trials investigating the cardioprotective effects of omega-3 fatty acids. Dietary

K. W. Lee; G. Y. H. LIP

2003-01-01

336

Combined metoprolol and ascorbic acid treatment prevents intrinsic damage to the heart during diabetic cardiomyopathy.  

PubMed

Metabolic disturbances and oxidative stress have been highlighted as potential causative factors for the development of diabetic cardiomyopathy. The ?-blocker metoprolol is known to improve function in the diabetic rat heart and ameliorates the sequelae associated with oxidative stress, without lowering oxidative stress. The antioxidant ascorbic acid is known to improve function in the diabetic rat heart. We tested whether a combination of ascorbic acid and metoprolol treatment would improve function further than each drug individually. Control and streptozotocin-induced diabetic Wistar rats were treated with metoprolol (15 mg·(kg body mass)(-1)·day(-1), via an osmotic pump) and (or) ascorbic acid (1000 mg·(kg body mass)(-1)·day(-1), via their drinking water). To study the effect of treatment on the development of dysfunction, we examined time points before (5 weeks diabetic) and after (7 weeks diabetic) development of overt systolic dysfunction. Echocardiography and working-heart-perfusion were used to assess cardiac function. Blood and tissue samples were collected to assess the severity of disease and oxidative stress. While both drugs improved function, only ascorbic acid had effects on oxidative damage. Combination treatment had a more pronounced improvement in function. Our ?-blocker + antioxidant treatment strategy focused on oxidative stress, not diabetes specifically; therefore, it may prove useful in other diseases where oxidative stress contributes to the pathology. PMID:25229873

Saran, Varun; Sharma, Vijay; Wambolt, Richard; Yuen, Violet G; Allard, Michael; McNeill, John Hugh

2014-10-01

337

A laboratory study of covers made of low-sulphide tailings to prevent acid mine drainage  

Microsoft Academic Search

Covers with capillary barrier effects (CCBE) are considered to be one of the most effective ways to control acid mine drainage (AMD) production from mine wastes. The use of low-sulphide tailings in CCBE has been proposed recently for cases where other types of material may be unavailable near the mining site. This paper presents leaching column test results showing that

B. Bussière; M. Benzaazoua; M. Aubertin; M. Mbonimpa

2004-01-01

338

Essential Fatty Acid Depletion of Renal Allografts and Prevention of Rejection  

Microsoft Academic Search

A central hypothesis in transplantation biology is that resident leukocytes expressing class II histocompatibility antigens may determine the immunogenicity of an organ. By means of a novel method to deplete the kidney of resident leukocytes, essential fatty acid deficiency (EFAD), this hypothesis was tested in an intact, vascular organ. Kidneys subjected to EFAD and thus depleted of resident Ia-positive macrophages

George F. Schreiner; Wayne Flye; Elizabeth Brunt; Ken Korber; James B. Lefkowith

1988-01-01

339

Disruption of glucose tolerance caused by glucocorticoid excess in rats is partially prevented, but not attenuated, by arjunolic acid.  

PubMed

Arjunolic acid (AA) obtained from plants of the Combretaceae family has shown anti-diabetic effects. Here, we analyzed whether the diabetogenic effects of dexamethasone (DEX) treatment on glucose homeostasis may be prevented or attenuated by the concomitant administration of AA. Adult Wistar rats were assigned to the following groups: vehicle-treated (Ctl), DEX-treated (1 mg/kg body weight intraperitoneally for 5 days) (Dex), AA-treated (30 mg/kg body weight by oral gavage twice per day) (Aa), AA treatment previous to and concomitant to DEX treatment (AaDex), and AA treatment after initiation of DEX treatment (DexAa). AA administration significantly ameliorated (AaDex) (P > 0.05), but did not attenuate (DexAa), the glucose intolerance induced by DEX treatment. AA did not prevent or attenuate the elevation in hepatic glycogen and triacylglycerol content caused by DEX treatment. All DEX-treated rats exhibited hepatic steatosis that seemed to be more pronounced when associated with AA treatment given for a prolonged period (AaDex). Markers of liver function and oxidative stress were not significantly altered among the groups. Therefore, AA administered for a prolonged period partially prevents the glucose intolerance induced by DEX treatment, but it fails to produce this beneficial effect when given after initiation of GC treatment. Since AA may promote further hepatic steatosis when co-administered with GCs, care is required when considering this phytochemical as a hypoglycemiant and/or insulin-sensitizing agent. PMID:25345246

Gonçalves-Neto, Luiz M; Ferreira, Francielle B D; Souza, Luiz; dos Santos, Cristiane; Boschero, Antonio C; Facundo, Valdir A; Santos, Adair R S; Nunes, Everson A; Rafacho, Alex

2014-10-01

340

Rosmarinic acid prevents lipid peroxidation and increase in acetylcholinesterase activity in brain of streptozotocin-induced diabetic rats.  

PubMed

We investigated the efficacy of rosmarinic acid (RA) in preventing lipid peroxidation and increased activity of acetylcholinesterase (AChE) in the brain of streptozotocin-induced diabetic rats. The animals were divided into six groups (n?=?8): control, ethanol, RA 10 mg/kg, diabetic, diabetic/ethanol and diabetic/RA 10 mg/kg. After 21 days of treatment with RA, the cerebral structures (striatum, cortex and hippocampus) were removed for experimental assays. The results demonstrated that the treatment with RA (10 mg/kg) significantly reduced the level of lipid peroxidation in hippocampus (28%), cortex (38%) and striatum (47%) of diabetic rats when compared with the control. In addition, it was found that hyperglycaemia caused significant increased in the activity of AChE in hippocampus (58%), cortex (46%) and striatum (30%) in comparison with the control. On the other hand, the treatment with RA reversed this effect to the level of control after 3 weeks. In conclusion, the present findings showed that treatment with RA prevents the lipid peroxidation and consequently the increase in AChE activity in diabetic rats, demonstrating that this compound can modulate cholinergic neurotransmission and prevent damage oxidative in brain in the diabetic state. Thus, we can suggest that RA could be a promising compound in the complementary therapy in diabetes. PMID:24301255

Mushtaq, Nadia; Schmatz, Roberta; Pereira, Luciane B; Ahmad, Mushtaq; Stefanello, Naiara; Vieira, Juliano M; Abdalla, Fátima; Rodrigues, Marília V; Baldissarelli, Jucimara; Pelinson, Luana Paula; Dalenogare, Diéssica P; Reichert, Karine Paula; Dutra, Eduardo M; Mulinacci, Nádia; Innocenti, Marzia; Bellumori, Maria; Morsch, Vera Maria; Schetinger, Maria Rosa

2014-04-01

341

21 CFR 184.1187 - Calcium alginate.  

...alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Calcium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents, or...

2014-04-01

342

Cooperative federal-state liming research on surface waters impacted by acidic deposition  

Microsoft Academic Search

In the eastern and north-central United States, lakes and streams with low acid neutralizing capacity are at risk from acidity. Resource management agencies are interested in developing mitigation strategies that protect or restore fisheries in these waters. Addition of limestone (calcium carbonate) to improve water quality and prevent episodic depressions of pH during precipitation events and spring runoff is one

R. Kent Schreiber

1988-01-01

343

Ursolic acid protects monocytes against metabolic stress-induced priming and dysfunction by preventing the induction of Nox4?  

PubMed Central

Aims Dietary supplementation with ursolic acid (UA) prevents monocyte dysfunction in diabetic mice and protects mice against atherosclerosis and loss of renal function. The goal of this study was to determine the molecular mechanism by which UA prevents monocyte dysfunction induced by metabolic stress. Methods and results Metabolic stress sensitizes or “primes” human THP-1 monocytes and murine peritoneal macrophages to the chemoattractant MCP-1, converting these cells into a hyper-chemotactic phenotype. UA protected THP-1 monocytes and peritoneal macrophages against metabolic priming and prevented their hyper-reactivity to MCP-1. UA blocked the metabolic stress-induced increase in global protein-S-glutathionylation, a measure of cellular thiol oxidative stress, and normalized actin-S-glutathionylation. UA also restored MAPK phosphatase-1 (MKP1) protein expression and phosphatase activity, decreased by metabolic priming, and normalized p38 MAPK activation. Neither metabolic stress nor UA supplementation altered mRNA or protein levels of glutaredoxin-1, the principal enzyme responsible for the reduction of mixed disulfides between glutathione and protein thiols in these cells. However, the induction of Nox4 by metabolic stress, required for metabolic priming, was inhibited by UA in both THP-1 monocytes and peritoneal macrophages. Conclusion UA protects THP-1 monocytes against dysfunction by suppressing metabolic stress-induced Nox4 expression, thereby preventing the Nox4-dependent dysregulation of redox-sensitive processes, including actin turnover and MAPK-signaling, two key processes that control monocyte migration and adhesion. This study provides a novel mechanism for the anti-inflammatory and athero- and renoprotective properties of UA and suggests that dysfunctional blood monocytes may be primary targets of UA and related compounds. PMID:24494201

Ullevig, Sarah L.; Kim, Hong Seok; Nguyen, Huynh Nga; Hambright, William S.; Robles, Andrew J.; Tavakoli, Sina; Asmis, Reto

2014-01-01

344

A-ring modified betulinic acid derivatives as potent cancer preventive agents.  

PubMed

Ten new 3,4-seco betulinic acid (BA) derivatives were designed and synthesized. Among them, compounds 7-15 exhibited enhanced chemopreventive ability in an in vitro short-term 12-O-tetradecanoylphorbol-13-acetate (TPA) induced Epstein-Barr virus early antigen (EBV-EA) activation assay in Raji cells. Specifically, analogs with a free C-28 carboxylic acid, including 7, 8, 11, and 13, inhibited EBV-EA activation significantly. The most potent compound 8 displayed 100% inhibition at 1×10(3) mol ratio/TPA and 73.4%, 35.9%, and 8.4% inhibition at 5×10(2), 1×10(2), and 1×10 mol ratio/TPA, respectively, comparable with curcumin at high concentration and better than curcumin at low concentration. The potent chemopreventive activity of novel seco A-ring BAs (8 and 11) was further confirmed in an in vivo mouse skin carcinogenesis assay. PMID:24411124

Hung, Hsin-Yi; Nakagawa-Goto, Kyoko; Tokuda, Harukuni; Iida, Akira; Suzuki, Nobutaka; Bori, Ibrahim D; Qian, Keduo; Lee, Kuo-Hsiung

2014-02-01

345

Ebselen inhibits hepatitis C virus NS3 helicase binding to nucleic Acid and prevents viral replication.  

PubMed

The hepatitis C virus (HCV) nonstructural protein 3 (NS3) is both a protease, which cleaves viral and host proteins, and a helicase that separates nucleic acid strands, using ATP hydrolysis to fuel the reaction. Many antiviral drugs, and compounds in clinical trials, target the NS3 protease, but few helicase inhibitors that function as antivirals have been reported. This study focuses on the analysis of the mechanism by which ebselen (2-phenyl-1,2-benzisoselenazol-3-one), a compound previously shown to be a HCV antiviral agent, inhibits the NS3 helicase. Ebselen inhibited the abilities of NS3 to unwind nucleic acids, to bind nucleic acids, and to hydrolyze ATP, and about 1 ?M ebselen was sufficient to inhibit each of these activities by 50%. However, ebselen had no effect on the activity of the NS3 protease, even at 100 times higher ebselen concentrations. At concentrations below 10 ?M, the ability of ebselen to inhibit HCV helicase was reversible, but prolonged incubation of HCV helicase with higher ebselen concentrations led to irreversible inhibition and the formation of covalent adducts between ebselen and all 14 cysteines present in HCV helicase. Ebselen analogues with sulfur replacing the selenium were just as potent HCV helicase inhibitors as ebselen, but the length of the linker between the phenyl and benzisoselenazol rings was critical. Modifications of the phenyl ring also affected compound potency over 30-fold, and ebselen was a far more potent helicase inhibitor than other, structurally unrelated, thiol-modifying agents. Ebselen analogues were also more effective antiviral agents, and they were less toxic to hepatocytes than ebselen. Although the above structure-activity relationship studies suggest that ebselen targets a specific site on NS3, we were unable to confirm binding to either the NS3 ATP binding site or nucleic acid binding cleft by examining the effects of ebselen on NS3 proteins lacking key cysteines. PMID:25126694

Mukherjee, Sourav; Weiner, Warren S; Schroeder, Chad E; Simpson, Denise S; Hanson, Alicia M; Sweeney, Noreena L; Marvin, Rachel K; Ndjomou, Jean; Kolli, Rajesh; Isailovic, Dragan; Schoenen, Frank J; Frick, David N

2014-10-17

346

Role of Ursodeoxycholic Acid in Prevention of Methotrexate-induced Liver Toxicity  

Microsoft Academic Search

Aim Methotrexate (MTX)-induced hepatotoxicity restricts the clinical use of this immunosuppressive drug. In this study, our aim\\u000a was to research the role of oxidative stress in the hepatic toxicity of MTX and the protective effect of ursodeoxycholic acid\\u000a (UDCA) in this setting. Methods Wistar type rats (n = 32) were divided into four groups; group-1 as the MTX + UDCA, group-2 as the MTX,

Suleyman Uraz; Veysel Tahan; Cem Aygun; Fatih Eren; Goksenin Unluguzel; Meral Yuksel; Omer Senturk; Erol Avsar; Goncagul Haklar; Cigdem Celikel; Sadettin Hulagu; Nurdan Tozun

2008-01-01

347

Salicylic Acid Reduces Napropamide Toxicity by Preventing Its Accumulation in Rapeseed ( Brassica napus L.)  

Microsoft Academic Search

Napropamide is a widely used herbicide for controlling weeds in crop production. However, extensive use of the herbicide has\\u000a led to its accumulation in ecosystems, thus causing toxicity to crops and reducing crop production and quality. Salicylic\\u000a acid (SA) plays multiple roles in regulating plant adaptive responses to biotic and environmental stresses. However, whether\\u000a SA regulates plant response to herbicides

Jing Cui; Rui Zhang; Guo Lin Wu; Hong Mei Zhu; Hong Yang

2010-01-01

348

Preventing disease transmission by deceased tissue donors by testing blood for viral nucleic acid  

Microsoft Academic Search

Nucleic acid testing (NAT) has reduced the risk of transmitting infectious disease through blood transfusion. Currently NAT\\u000a for HIV-1 and HCV are FDA licensed and performed by nearly all blood collection facilities, but HBV NAT is performed under\\u000a an investigational study protocol. Residual risk estimates indicate that NAT could potentially reduce disease transmission\\u000a through transplanted tissue. However, tissue donor samples

D. Michael Strong; Karen Nelson; Marge Pierce; Susan L. Stramer

2005-01-01

349

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

SciTech Connect

The generation and release of acidic drainage containing high concentrations of dissolved metals from decommissioned mine wastes is an environmental problem of international scale. A potential solution to many acid drainage problems is the installation of permeable reactive walls into aquifers affected by drainage water derived from mine waste materials. A permeable reactive wall installed into an aquifer impacted by low-quality mine drainage waters was installed in August 1995 at the Nickel Rim mine site near Sudbury, Ontario. The reactive mixture, containing organic matter, was designed to promote bacterially mediated sulfate reduction and subsequent metal sulfide precipitation. The reactive wall is installed to an average depth of 12 feet (3.6 m) and is 49 feet (15 m) long perpendicular to ground water flow. The wall thickness (flow path length) is 13 feet (4 m). Initial results, collected nine months after installation, indicate that sulfate reduction and metal sulfide precipitation is occurring. The reactive wall has effectively removed the capacity of the ground water to generate acidity on discharge to the surface. Calculations based on comparison to previously run laboratory column experiments indicate that the reactive wall has potential to remain effective for at least 15 years.

Benner, S.G.; Blowes, D.W.; Ptacek, C.J.

1997-12-31

350

Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP)-mediated Calcium Signaling and Arrhythmias in the Heart Evoked by ?-Adrenergic Stimulation*?  

PubMed Central

Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most potent Ca2+-releasing second messenger known to date. Here, we report a new role for NAADP in arrhythmogenic Ca2+ release in cardiac myocytes evoked by ?-adrenergic stimulation. Infusion of NAADP into intact cardiac myocytes induced global Ca2+ signals sensitive to inhibitors of both acidic Ca2+ stores and ryanodine receptors and to NAADP antagonist BZ194. Furthermore, in electrically paced cardiac myocytes BZ194 blocked spontaneous diastolic Ca2+ transients caused by high concentrations of the ?-adrenergic agonist isoproterenol. Ca2+ transients were recorded both as increases of the free cytosolic Ca2+ concentration and as decreases of the sarcoplasmic luminal Ca2+ concentration. Importantly, NAADP antagonist BZ194 largely ameliorated isoproterenol-induced arrhythmias in awake mice. We provide strong evidence that NAADP-mediated modulation of couplon activity plays a role for triggering spontaneous diastolic Ca2+ transients in isolated cardiac myocytes and arrhythmias in the intact animal. Thus, NAADP signaling appears an attractive novel target for antiarrhythmic therapy. PMID:23564460

Nebel, Merle; Schwoerer, Alexander P.; Warszta, Dominik; Siebrands, Cornelia C.; Limbrock, Ann-Christin; Swarbrick, Joanna M.; Fliegert, Ralf; Weber, Karin; Bruhn, Soren; Hohenegger, Martin; Geisler, Anne; Herich, Lena; Schlegel, Susan; Carrier, Lucie; Eschenhagen, Thomas; Potter, Barry V. L.; Ehmke, Heimo; Guse, Andreas H.

2013-01-01

351

Fusidic acid and rifampicin co-loaded PLGA nanofibers for the prevention of orthopedic implant associated infections.  

PubMed

Implant-associated infections following invasive orthopedic surgery are a major clinical problem, and are one of the primary causes of joint failure following total joint arthroplasty. Current strategies using perioperative antibiotics have been met with little clinical success and have resulted in various systemic toxicities and the promotion of antibiotic resistant microorganisms. Here we report the development of a biodegradable localized delivery system using poly(D,L-lactic acid-co-glycolic acid) (PLGA) for the combinatorial release of fusidic acid (FA) (or its sodium salt; SF) and rifampicin (RIF) using electrospinning. The drug-loaded formulations showed good antibiotic encapsulation (~75%-100%), and a biphasic drug release profile. All dual-loaded formulations showed direct antimicrobial activity in vitro against Staphylococcus epidermidis, and two strains of methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, lead formulations containing 10% (w/w) FA/SF and 5% (w/w) RIF were able to prevent the adherence of MRSA to a titanium implant in an in vivo rodent model of subcutaneous implant-associated infection. PMID:23639451

Gilchrist, Samuel E; Lange, Dirk; Letchford, Kevin; Bach, Horacio; Fazli, Ladan; Burt, Helen M

2013-08-28

352

Corosolic acid prevents oxidative stress, inflammation and hypertension in SHR/NDmcr-cp rats, a model of metabolic syndrome.  

PubMed

Corosolic acid (CRA), a constituent of banaba leaves, has been reported to have anti-inflammatory and hypoglycemic activities. The aim of this study was to determine the effects of CRA on metabolic risk factors including obesity, hypertension, hyperinsulinemia, hyperglycemia, and hyperlipidemia together with oxidative stress and inflammation, all of which are characteristic of the SHR/NDmcr-cp (cp/cp) (SHR-cp) rat, an animal model of metabolic syndrome. Six-week-old male SHR-cp rats were fed a high fat diet containing 0.072% CRA for 14 weeks. Treatment with CRA lowered blood pressure, which was elevated in control animals, by 10% after 8 weeks, and serum free fatty acids by 21% after 2 weeks. CRA treatment resulted in decreases in the levels of the oxidative stress markers thiobarbituric acid-reactive substances and 8-hydroxydeoxyguanosine by 27% and 59%, respectively, after 2 weeks. CRA treatment also reduced the levels of myeloperoxidase markers, 3-nitrotyrosine and 3-chlorotyrosine by 38% and 39%, respectively, after 10 weeks, and tended to decrease the levels of high sensitivity C-reactive protein, a marker of inflammation, after 6 weeks. However, CRA had no effect on weight gain or hyperglycemia. These results demonstrate that CRA can ameliorate hypertension, abnormal lipid metabolism, and oxidative stress as well as the inflammatory state in SHR-cp rats. This implies that CRA can be beneficial for preventing atherosclerosis-related diseases that are an increasing health care problem worldwide. PMID:16959274

Yamaguchi, Yu; Yamada, Kotaro; Yoshikawa, Noriko; Nakamura, Kazuki; Haginaka, Jun; Kunitomo, Masaru

2006-11-25

353

Calcium orthophosphates  

PubMed Central

The present overview is intended to point the readers’ attention to the important subject of calcium orthophosphates. This type of materials is of special significance for human beings, because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with calcium orthophosphates, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenphosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of calcium orthophosphates. Similarly, dental caries and osteoporosis might be considered an in vivo dissolution of calcium orthophosphates. Thus, calcium orthophosphates hold a great significance for humankind, and in this paper, an overview on the current knowledge on this subject is provided. PMID:23507744

Dorozhkin, Sergey V.

2011-01-01

354

R E S E A R C H A R T I C L E Fungicidalactivityofamiodarone istightlycoupled to calcium inux  

E-print Network

amiodarone; calcium influx; fungicide; cell death; calcium stress. Abstract The antiarrhythmic drug inset] is listed as a Class III antiarrhythmic drug that prevents atrial fibrillation and ventricular

Rao, Rajini

355

Blocking the calcium cascade in experimental acute renal failure.  

PubMed

Calcium is believed to be responsible for initiating a deleterious cascade of events that leads to irreversible cell injury during prolonged ischemia. Theoretically, the calcium-dependent cascade of events can be interrupted at three distinct points: a) by reducing calcium inflow into the cytosol using a calcium channel blocker such as verapamil, b) by increasing the mitochondrial capacity to sequester calcium using ethane-1-hydroxy-1:1-diphosphonic acid (EHDP), and c) by inhibiting the activation of the calcium-calmodulin complex using trifluoperazine (TFP). To evaluate the protective role of these agents in prolonged ischemia, 190 unilaterally nephrectomized rats underwent total occlusion of the renal artery for 90 min. One hour before surgery, all the rats received an i.p. injection of either saline or one of the drugs. Of the 190 rats, 130 were used to determine survival and optimal drug doses; the remaining 60 rats were used to determine blood urea nitrogen and serum creatinine at 40 h and 5 days after surgery. Only 33% of the rats in the control group survived for 10 days. However, 87.5% (P less than 0.005), 90% (P less than 0.005), and 60% (P less than 0.01) of the rats pretreated with verapamil, TFP and EHDP respectively survived for 10 days. No differences, however, were seen in renal function tests among the control, TFP or EHDP groups. This suggests that calcium antagonists are successful in protecting the kidney from prolonged ischemic injury despite impaired renal function tests. It may also indicate that these agents delay or prevent the ischemic cells from undergoing irreversible damage. PMID:2116382

Greif, F; Anais, D; Frei, L; Arbeit, L; Sorroff, H S

1990-06-01

356

L/N-type calcium channel blocker cilnidipine reduces plasma aldosterone, albuminuria, and urinary liver-type fatty acid binding protein in patients with chronic kidney disease.  

PubMed

Cilnidipine inhibits both L- and N-type calcium channels and has been shown to dilate efferent arterioles as effectively as afferent arterioles. We conducted an open-label, randomized trial to compare the effects of cilnidipine against those of amlodipine on blood pressure (BP), albuminuria, and plasma aldosterone concentration in hypertensive patients with mild- to moderate-stage chronic kidney disease. Patients with BP ?130/80 mmHg, an estimated glomerular filtration rate of 90-30 ml/min/1.73 m(2), and albuminuria ?30 mg/g, despite treatment with the maximum recommended dose of angiotensin II receptor blockers, were randomly assigned to two groups. Patients received either 10 mg/day cilnidipine (increased to 20 mg/day; n = 35) or 2.5 mg/day amlodipine (increased to 5 mg/day; n = 35). After 48 weeks of treatment, a significant and comparable reduction in systolic and diastolic BP was observed in both groups. The percent reduction in the urinary albumin to creatinine ratio and liver-type fatty acid binding protein (L-FABP) in the cilnidipine group was significantly greater than in the amlodipine group. Although plasma renin activity did not differ between the two groups, the plasma aldosterone level was significantly decreased in the cilnidipine group. Cilnidipine therefore appears to reduce albuminuria, urinary L-FABP, and plasma aldosterone levels more than amlodipine, and these effects are independent of BP reduction. PMID:22914905

Abe, Masanori; Maruyama, Noriaki; Suzuki, Hiroko; Inoshita, Atsushi; Yoshida, Yoshinori; Okada, Kazuyoshi; Soma, Masayoshi

2013-07-01

357

In vitro degradation, biocompatibility, and in vivo osteogenesis of poly(lactic-co-glycolic acid)/calcium phosphate cement scaffold with unidirectional lamellar pore structure.  

PubMed

The aim of this study was to investigate the in vitro degradation, cytocompatibility, and in vivo osteogenesis of poly(lactic-co-glycolic acid) (PLGA)/calcium phosphate cement (CPC) scaffold with unidirectional lamellar pore structure. CPC-based scaffold was fabricated by unidirectional freeze casting, and PLGA was used to improve the mechanical properties of the CPC-based scaffold, which covered the surface of the pore wall as coating. The in vitro degradation results demonstrated that the PLGA/CPC scaffold had good degradability. The degradation of PLGA film on the surface of the scaffold made the CPC matrix exposed, which facilitated cell response and osteogenesis. Rat bone mesenchymal stem cells (rMSCs) were seeded on the PLGA/CPC composite scaffold. Cell viability, proliferation, and differentiation on the PLGA/CPC composite scaffold were evaluated. The results showed that viable rMSCs attached on the surface of pore wall gradually penetrated into the internal pores of the scaffold as prolongation of culture time. In addition, the rMSCs seeded on the scaffold exhibited good proliferation and growing alkaline phosphatase activity. The scaffold was implanted in the defects in distal end of femora of New Zealand white rabbits. Histological evaluation indicated that the PLGA/CPC scaffold with unidirectional lamellar pore structure had good biocompatibility and effective osteogenesis. These results suggest PLGA/CPC composite scaffold with unidirectional lamellar pore structure is a promising scaffold for bone tissue engineering. PMID:22733543

He, Fupo; Ye, Jiandong

2012-12-01

358

A controlled release of antibiotics from calcium phosphate-coated poly(lactic-co-glycolic acid) particles and their in vitro efficacy against Staphylococcus aureus biofilm.  

PubMed

Ceramic-polymer hybrid particles, intended for osteomyelitis treatment, were fabricated by preparing poly(lactic-co-glycolic acid) particles through an emulsion solvent evaporation technique, followed by calcium phosphate (CaP) coating via a surface adsorption-nucleation method. The presence of CaP coating on the surface of the particles was confirmed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Subsequently, two antibiotics for treating bone infection, nafcillin (hydrophilic) and levofloxacin (amphiphilic), were loaded into these hybrid particles and their in vitro drug release studies were investigated. The CaP coating was shown to reduce burst release, while providing sustained release of the antibiotics for up to 4 weeks. In vitro bacterial study against Staphylococcus aureus demonstrated the capability of these antibiotic-loaded hybrid particles to inhibit biofilm formation as well as deteriorate established biofilm, making this hybrid system a potential candidate for further investigation for osteomyelitis treatment. PMID:24370968

Bastari, Kelsen; Arshath, Mohamed; Ng, Zhi Hui Melissa; Chia, Jia Hua; Yow, Zhi Xian Daniel; Sana, Barindra; Tan, Meng Fong Cherine; Lim, Sierin; Loo, Say Chye Joachim

2014-03-01

359

Calcium phosphate glass improves angiogenesis capacity of poly(lactic acid) scaffolds and stimulates differentiation of adipose tissue-derived mesenchymal stromal cells to the endothelial lineage.  

PubMed

The angiogenic capacity of a new biomaterial composite of poly(lactic acid) and calcium phosphate glass (PLA/CaP) was analyzed by noninvasive bioluminescence imaging (BLI) and histological procedures. Human adipose tissue-derived mesenchymal stromal cells expressing cytomegalovirus (CMV) promoter regulated Photinus pyralis luciferase (hAMSC-PLuc) grew up to 30 times the initial cell load, in vitro, when seeded in PLA/CaP scaffolds, but suffered an initial growth crisis followed by recovery when the scaffolds were subcutaneously implanted in SCID mice. To analyze changes in gene expression, hAMSC-PLuc cells were double labeled with a CMV promoter regulated Renilla reniformis luciferase and a Photinus pyralis luciferase reporter regulated by either the PECAM promoter or a hypoxia response element (HRE) artificial promoter and seeded in PLA/CaP and PLA scaffolds implanted in SCID mice. Analysis by BLI showed that hAMSCs in scaffolds were induced to differentiate to the endothelial lineage and did this faster in PLA/CaP than in PLA scaffolds. Endothelial differentiation correlated with a decrease in the activity of HRE regulated luciferase expression, indicative of a reduction of hypoxia. Histological analysis showed that PLA/CaP scaffolds were colonized by a functional host vascular system. Moreover, colonization by isolectin B(4) positive host cells was more effective in PLA/CaP than in PLA scaffolds, corroborating BLI results. PMID:22962041

Vila, Olaia F; Bagó, Juli R; Navarro, Melba; Alieva, Maria; Aguilar, Elisabeth; Engel, Elisabeth; Planell, Josep; Rubio, Nuria; Blanco, Jerónimo

2013-04-01

360

Surface aggregation of urinary proteins and aspartic acid-rich peptides on the faces of calcium oxalate monohydrate investigated by in situ force microscopy  

SciTech Connect

The growth of calcium oxalate monohydrate in the presence of Tamm-Horsfall protein (THP), osteopontin (OPN), and the 27-residue synthetic peptides (DDDS){sub 6}DDD and (DDDG){sub 6}DDD [where D = aspartic acid and X = S (serine) or G (glycine)] was investigated via in situ atomic force microscopy (AFM). The results show that these three growth modulators create extensive deposits on the crystal faces. Depending on the modulator and crystal face, these deposits can occur as discrete aggregates, filamentary structures, or uniform coatings. These proteinaceous films can lead to either the inhibition or increase of the step speeds (with respect to the impurity-free system) depending on a range of factors that include peptide or protein concentration, supersaturation and ionic strength. While THP and the linear peptides act, respectively, to exclusively increase and inhibit growth on the (-101) face, both exhibit dual functionality on the (010) face, inhibiting growth at low supersaturation or high modulator concentration and accelerating growth at high supersaturation or low modulator concentration. Based on analyses of growth morphologies and dependencies of step speeds on supersaturation and protein or peptide concentration, we argue for a picture of growth modulation that accounts for the observations in terms of the strength of binding to the surfaces and steps and the interplay of electrostatic and solvent-induced forces at crystal surface.

Weaver, M L; Qiu, S R; Hoyer, J R; Casey, W H; Nancollas, G H; De Yoreo, J J

2008-05-28

361

Evaluation of biomechanical strength, stability, bioactivity, and in vivo biocompatibility of a novel calcium deficient hydroxyapatite/poly(amino acid) composite cervical vertebra cage.  

PubMed

A new type of cervical vertebra cage was prepared using a novel composite, calcium deficient hydroxyapatite/poly(amino acid) (HA/PAA), and its mechanical properties, in vitro stability and bioactivity, and in vivo biocompatibility were characterized. The results showed that the axial compressive loads of the HA/PAA cage were in the range of 10058-10612 N and the lateral compressive loads were in the range of 1180-2363 N, and varied with the height of the cervical vertebra cages. After immersion in simulated body fluid (SBF) for 16 weeks, the axial compressive loads of the cage decreased from 10058 to 7131 N and the lateral compressive loads decreased from 1180 to 479 N. In addition, the weight loss decreased 6.01%, showing that HA/PAA composites had good stability during the incubation period. The pH value of SBF was also monitored during the whole soaking period; it fluctuated in the range of 6.9-7.4. Scanning electron microscope and energy dispersive spectrometer results showed the cage was bioactive with a new apatite layer attached on the surface. The histological evaluation revealed that new bone tissue bonded tightly with the surfaces of the implants, showing excellent biocompatibility. In conclusion, the HA/PAA cage showed sufficient strength, good stability, bioactivity, and biocompatibility, and has potential applications for clinical cervical vertebrae repair. PMID:25162474

Xiong, Yi; Li, Hong; Zhou, Chunguang; Yang, Xi; Song, Yueming; Qing, Yan; Yan, Yonggang

2014-11-01

362

Primary prevention of neural-tube defects and some other congenital abnormalities by folic acid and multivitamins: history, missed opportunity and tasks  

PubMed Central

The history of intervention trials of periconception folic acid with multivitamin and folic acid supplementation in women has shown a recent breakthrough in the primary prevention of structural birth defects, namely neural-tube defects and some other congenital abnormalities. Recently, some studies have demonstrated the efficacy of this new method in reducing congenital abnormalities with specific origin; for example, in the offspring of diabetic and epileptic mothers, and in pregnancy with high fever. The benefits and drawbacks of four possible uses of periconception folate/folic acid and multivitamin supplementation are discussed: we believe there has been a missed opportunity to implement this preventive approach in medical practice. The four methods are as follows: (i) dietary intake of folate and other vitamins, (ii) periconception folic acid/multivitamin supplementation, (iii) food fortification with folic acid, and (iv) the combination of oral contraceptives with 6S-5-methytetrahydrofolate (‘folate’). PMID:25083211

Bártfai, Zoltán; Bánhidy, Ferenc

2011-01-01

363

Halothane prevents nitrous oxide teratogenicity in Sprague-Dawley rats; folinic acid does not.  

PubMed

The teratogenic effects of nitrous oxide (N2O) administered with halothane or folinic acid (FA) were studied in two separate experiments using a total of 206 timed-pregnant Sprague-Dawley rats. In each experiment, rats were exposed to either 1) air (n = 30-40); 2) N2O (50-75% for 24 h on day 8 of pregnancy, n = 20-30); 3) test agent (i.e., 0.27% halothane for 24 h on day 8 of pregnancy; or 5 mg/kg/day of FA on day 5-13 of pregnancy, subcutaneously by osmotic pump, n = 20-30); or 4) N2O + test agent (n = 20-30). Cesarean sections were performed on day 20, and fetuses were examined for visceral and skeletal abnormalities. There were no differences in pregnancy rate, number of implantations and live fetuses per rat, and fetal weight among any of the groups. Treatment with N2O resulted in significantly higher incidences of resorptions and of major visceral and minor skeletal abnormalities. Halothane administered with N2O protected against these effects; folinic acid did not. Using an additional 65 nonpregnant rats, hepatic methionine synthase activity was measured after treatment with 50% N2O, 50% N2O plus 0.27% halothane, or 50% N2O plus 5 mg/kg/day of folinic acid. Methionine synthase activity was equally depressed in all groups. These findings do not support the commonly held theory that inactivation of methionine synthase is the sole cause of N2O teratogenicity; rather, they suggest a multifactorial etiology, which may include changes in uterine blood flow. PMID:3262935

Mazze, R I; Fujinaga, M; Baden, J M

1988-08-01

364

Urinary excretion of calcium, magnesium, phosphate, citrate, oxalate, and uric acid by healthy schoolchildren using a 12-h collection protocol.  

PubMed

Although we do not have reliable data for the true prevalence of urolithiasis during childhood, the number of patients seen in outpatient clinics and admitted for stone-related problems is steadily increasing worldwide. As for most pediatric patients a metabolic disease is the reason for stone development, because a high number of patients have severely recurrent urolithiasis, early and proper diagnostic evaluation is necessary to begin adequate and preventive treatment. However, diagnostic evaluation, especially in infants and younger children, is not always easy, and frequently a diagnosis is made late. Diagnostic evaluation should start with repeated urine analysis; but how and which urine should be collected and analyzed? What is the best and most accurate method for urine collection? In a paper published in a recent issue of Pediatric Nephrology, Torres and colleagues describe a more simplified method of urine collection. They propose analysis of late-afternoon spot-urine samples as well as an overnight collection of urine as the most appropriate to evaluate patient-specific urinary risk factors. Is this truly the case? PMID:25173356

Hoppe, Bernd

2014-11-01

365

Knowledge and periconceptional use of folic acid for the prevention of neural tube defects in ethnic communities in the United Kingdom: Systematic review and meta-analysis  

PubMed Central

BACKGROUND: It is widely accepted that periconceptional supplementation with folic acid can prevent a significant proportion of neural tube defects (NTDs). The present study evaluated how folic acid knowledge and periconceptional use for NTD prevention varies by ethnicity in the United Kingdom (U.K.). METHODS: A literature search was conducted to identify studies that included assessment of folic acid knowledge or use in U.K. women of different ethnicities. Only research and referenced sources published after 1991, the year of the landmark Medical Research Council’s Vitamin Study, were included. A meta-analysis was performed of studies that assessed preconceptional folic acid use in Caucasians and non-Caucasians. RESULTS: Five studies met the inclusion criteria for assessment of knowledge and/or use of folic acid supplements in U.K. women including non-Caucasians. The available evidence indicates that South Asians specifically have less knowledge and lower periconceptional use of folic acid than Caucasians; one study found that West Indian and African women also had lower folic acid uptake. A synthesis of results from three of the studies, in a meta-analysis, shows that Caucasians are almost three times more likely to take folic acid before conception than non-Caucasians. CONCLUSION: From the limited evidence available, U.K. women of non-Caucasian ethnicity appear to have less knowledge and a lower uptake of folic acid supplementation than Caucasians during the periconceptional period. Implementing targeted, innovative education campaigns together with a mandatory fortification policy, including the fortification of ethnic minority foods, will be required for maximum prevention of folic acid–preventable NTDs across different ethnic groups. Birth Defects Research (Part A) 97:444–451, 2013. © 2013 Wiley Periodicals, Inc. PMID:23873812

Peake, Jordana N; Copp, Andrew J; Shawe, Jill

2013-01-01

366

Long-term effects of dietary calcium on risk markers for colon cancer in patients with familial polyposis.  

PubMed

There is conflicting evidence regarding the benefit of calcium in prevention of colon cancer. Patients who have undergone ileorectal operations for familial polyposis can be useful to study hypotheses on prevention of colon cancer. In this study we evaluated the effect of long-term calcium supplementation on risk markers of colon cancer. Thirty-one patients with familial polyposis, after subtotal colectomy, were randomized to group A, which received placebo, and group B, which received 1200 mg of calcium daily. Intervention lasted 9 months, in which they underwent four 3-monthly evaluations that included food records, fecal pH, calcium and bile acids, and rectal biopsy for thymidine labeling. Age, height, weight, macronutrients, and dietary fiber were comparable in both groups. More women were in the group that received placebo. Fecal pH, weight, and bile acid levels were similar before intervention and remained unchanged. Fecal calcium levels were similar before intervention and increased in the calcium group throughout the study (p less than 0.05). Labeling index of placebo and calcium groups was similar before intervention (4.8 and 6.1, respectively). After 3 months it was reduced in both groups (3.1 and 4.4, respectively; p less than 0.05). After 6 months it was reduced only in the calcium group (3.4; p less than 0.05). After 9 months it did not differ from the starting point (3.4 and 4.0, respectively). In a long-term intervention study with a homogenous group of patients with familial polyposis, supplemental dietary calcium did not affect mucosal risk factors for colon cancer. PMID:2168586

Stern, H S; Gregoire, R C; Kashtan, H; Stadler, J; Bruce, R W

1990-09-01

367

Implementing preventive iron-folic acid supplementation among women of reproductive age in some Western Pacific countries: possibilities and challenges.  

PubMed

Lack of effective implementation mechanisms is identified as a major obstacle in the prevention and control of iron-deficiency anemia. This paper discusses experiences gained from implementing iron-folic acid supplementation in the Philippines, Vietnam, and Cambodia. The understanding of contextual elements is proposed as a foundation for planning interventions. Moreover, it is suggested that a social marketing framework should provide a way of thinking about how to influence related behaviors. The application of a social marketing framework applied using a "5 P's" approach: public relations and collaboration, product, price, place, and promotion, is described, as well as enabling factors (possibilities) and inhibiting factors (challenges) of this approach. Although a program to improve iron nutrition among women of reproductive age may not be simple to implement, it is essential to enhancing health, human development, and economic advancement in developing countries. PMID:16466083

Smitasiri, Suttilak; Solon, Florentino S

2005-12-01

368

A newborn lethal defect due to inactivation of retinaldehyde dehydrogenase type 3 is prevented by maternal retinoic acid treatment.  

PubMed

The retinoic acid (RA) signal, produced locally from vitamin A by retinaldehyde dehydrogenase (Raldh) and transduced by the nuclear receptors for retinoids (RA receptor and 9-cis-RA receptor), is indispensable for ontogenesis and homeostasis of numerous tissues. We demonstrate that Raldh3 knockout in mouse suppresses RA synthesis and causes malformations restricted to ocular and nasal regions, which are similar to those observed in vitamin A-deficient fetuses and/or in retinoid receptor mutants. Raldh3 knockout notably causes choanal atresia (CA), which is responsible for respiratory distress and death of Raldh3-null mutants at birth. CA is due to persistence of nasal fins, whose rupture normally allows the communication between nasal and oral cavities. This malformation, which is similar to isolated congenital CA in humans and may result from impaired RA-controlled down-regulation of Fgf8 expression in nasal fins, can be prevented by a simple maternal treatment with RA. PMID:14623956

Dupé, Valérie; Matt, Nicolas; Garnier, Jean-Marie; Chambon, Pierre; Mark, Manuel; Ghyselinck, Norbert B

2003-11-25

369

A newborn lethal defect due to inactivation of retinaldehyde dehydrogenase type 3 is prevented by maternal retinoic acid treatment  

PubMed Central

The retinoic acid (RA) signal, produced locally from vitamin A by retinaldehyde dehydrogenase (Raldh) and transduced by the nuclear receptors for retinoids (RA receptor and 9-cis-RA receptor), is indispensable for ontogenesis and homeostasis of numerous tissues. We demonstrate that Raldh3 knockout in mouse suppresses RA synthesis and causes malformations restricted to ocular and nasal regions, which are similar to those observed in vitamin A-deficient fetuses and/or in retinoid receptor mutants. Raldh3 knockout notably causes choanal atresia (CA), which is responsible for respiratory distress and death of Raldh3-null mutants at birth. CA is due to persistence of nasal fins, whose rupture normally allows the communication between nasal and oral cavities. This malformation, which is similar to isolated congenital CA in humans and may result from impaired RA-controlled down-regulation of Fgf8 expression in nasal fins, can be prevented by a simple maternal treatment with RA. PMID:14623956

Dupe, Valerie; Matt, Nicolas; Garnier, Jean-Marie; Chambon, Pierre; Mark, Manuel; Ghyselinck, Norbert B.

2003-01-01

370

Control of. cap alpha. -amylase mRNA accumulation by gibberellic acid and calcium in barley aleurone layers  

SciTech Connect

Pulse-labeling of barley (Hordeum vulgare L. cv Himalaya) aleurone layers incubated for 13 hours in 2.5 micromolar gibberellic acid (GA/sub 3/) with or without 5 millimolar CaCl/sub 2/ shows that ..cap alpha..-amylase isozymes 3 and 4 are not synthesized in vivo in the absence of Ca/sup 2 +/. No difference was observed in ..cap alpha..-amylase mRNA levels between layers incubated for 12 hours in 2.5 micromolar GA/sub 3/ with 5 millimolar CaCl/sub 2/ and layers incubated in GA/sub 3/ alone. RNA isolated from layers incubated for 12 hours in GA/sub 3/ with and without CA/sup 2 +/. A cDNA clone for ..cap alpha..-amylase was isolated and used to measure ..cap alpha..-amylase mRNA levels in aleurone layers incubated in the presence and absence of Ca/sup 2 +/ was translated in vitro and was found to produce the same complement of translation products regardless of the presence of Ca/sup 2 +/ in the incubation medium. Immunoprecipitation of translation products showed that the RNA for ..cap alpha..-amylase synthesized in Ca/sup 2 +/-deprived aleurone layers was translatable. Ca/sup 2 +/ is required for the synthesis of ..cap alpha..-amylase isozymes 3 and 4 at a step after mRNA accumulation and processing.

Deikman, J.; Jones, R.L.

1985-01-01

371

on Moisture, Firmness, and Calcium Levels of Cheese  

Microsoft Academic Search

Blue cheese was made by direct acidifica- tion of milk, with phosphoric, hydrochloric, lactic, and citric acids prior to rennet co- agulation. These acids except citric were used to make Pizza cheese. Calcium levels were significantly higher in both varieties of cheese made with phosphoric acid; Blue cheese made with citric acid had the lowest calcium level. Cheese made with

A. E. SHEHATA; MEENA IYER; N. F. OLSON; T. RICHARDSON

372

Salicylic acid improves the salinity tolerance of Medicago sativa in symbiosis with Sinorhizobium meliloti by preventing nitrogen fixation inhibition.  

PubMed

In this work we have investigated the contribution of pretreatment with 0.1 and 0.5mM salicylic acid (SA) to the protection against salt stress in root nodules of Medicago sativa in symbiosis with Sinorhizobium meliloti. SA alleviated the inhibition induced by salinity in the plant growth and photosynthetic capacity of M. sativa-S. meliloti symbiosis. In addition, SA prevented the inhibition of the nitrogen fixation capacity under salt stress since nodule biomass was not affected by salinity in SA pretreated plants. Antioxidant enzymes peroxidase (POX), superoxide dismutase (SOD), ascorbate peroxidase (APX), dehidroascorbate reductase (DHAR) and glutathione reductase (GR), key in the main pathway that scavenges H2O2 in plants, were induced by SA pretreatments which suggest that SA may participate in the redox balance in root nodules under salt stress. Catalase activity (CAT) was inhibited around 40% by SA which could be behind the increase of H2O2 detected in nodules of plants pretreated with SA. The accumulation of polyamines (PAs) synthesized in response to salinity was prevented by SA which together with the induction of 1-aminocyclopropane-l-carboxylic acid (ACC) content suggest the prevalence of the ethylene signaling pathway induced by SA in detriment of the synthesis of PAs. In conclusion, SA alleviated the negative effect of salt stress in the M. sativa-S. meliloti symbiosis through the increased level of nodule biomass and the induction of the nodular antioxidant metabolism under salt stress. The H2O2 accumulation and the PAs inhibition induced by SA in nodules of M. sativa suggest that SA activates a hypersensitive response dependent on ethylene. PMID:23683932

Palma, F; López-Gómez, M; Tejera, N A; Lluch, C

2013-07-01

373

CASE REPORT Calcium Oxalate Precipitates  

E-print Network

We report a case of calcium oxalate deposition in a renomedullary interstitial cell tumor (RICT) in a patient dying of full-blown AIDS. The precipitates showed birefringence using a partially polaris ed light and were stained black in Yasue’s silver nit rate-rubeanic acid method. The combination of calcium oxalosis and RICT has not been reported before and might possibly be due to systemic biochemical alterations of the glycosaminoglycans as a result of profound metabolic disturbances in AIDS

Irene Pecorella; Sebastian B Lucas; Antonio Ciardi; Lorenzo Memeo; Robert F Miller

374

Calcium determination in serum with stable alkaline Arsenazo III and triglyceride clearing.  

PubMed

We describe an analytical procedure for determining serum calcium, using the ligand Arsenazo III in an aqueous alkaline medium. The choice of pH for the proposed technique differs from current procedures, which are for the most part carried out in a slightly acidic medium. An acidic medium avoids interference from magnesium, but is spectrophotometrically suboptimal for this pH-dependent reaction: the molar absorptivity of the Arsenazo III complex with calcium at acid pH is 13,787 L mol-1 cm-1, about one-half of that at a more optimal alkaline pH (26,574 L mol-1 cm-1). We have included a clearing technique in the reagent to avoid spectral aberrations from hypertriglyceridemic samples. alpha-Cyclodextrin absorbs the nonesterified fatty acids liberated from triglycerides by a microbial lipase. This modification may also be helpful for binding nonesterified fatty acids, which are known to interfere with calcium procedures by forming calcium soaps and thus preventing the reaction with intended ligands. The use of 8-hydroxyquinoline sulfonate as the magnesium-masking agent facilitates the use of alkaline pH. The less-water-soluble alternative, 8-hydroxyquinoline, commonly used as a precipitating agent for several methods, is difficult to solubilize in the alkaline reagent and tends to precipitate when complexed to magnesium. Finally, the use of alkaline pH results in a prolonged (> or = 6 weeks) shelf life for the reagent. PMID:8353945

Morgan, B R; Artiss, J D; Zak, B

1993-08-01

375

Salvianolic Acid A, a Novel Matrix Metalloproteinase-9 Inhibitor, Prevents Cardiac Remodeling in Spontaneously Hypertensive Rats  

PubMed Central

Cardiac fibrosis is a deleterious consequence of hypertension which may further advance to heart failure and increased matrix metalloproteinase-9 (MMP-9) contributes to the underlying mechanism. Therefore, new therapeutic strategies to attenuate the effects of MMP-9 are urgently needed. In the present study, we characterize salvianolic acid A (SalA) as a novel MMP-9 inhibitor at molecular, cellular and animal level. We expressed a truncated form of MMP-9 which contains only the catalytic domain (MMP-9 CD), and used this active protein for enzymatic kinetic analysis and Biacore detection. Data generated from these assays indicated that SalA functioned as the strongest competitive inhibitor of MMP-9 among 7 phenolic acids from Salvia miltiorrhiza. In neonatal cardiac fibroblast, SalA inhibited fibroblast migration, blocked myofibroblast transformation, inhibited secretion of intercellular adhesion molecule (ICAM), interleukin-6 (IL-6) and soluble vascular cell adhesion molecule-1 (sVCAM-1) as well as collagen induced by MMP-9 CD. Functional effects of SalA inhibition on MMP-9 was further confirmed in cultured cardiac H9c2 cell overexpressing MMP-9 in vitro and in heart of spontaneously hypertensive rats (SHR) in vivo. Moreover, SalA treatment in SHR resulted in decreased heart fibrosis and attenuated heart hypertrophy. These results indicated that SalA is a novel inhibitor of MMP-9, thus playing an inhibitory role in hypertensive fibrosis. Further studies to develop SalA and its analogues for their potential clinical application of cardioprotection are warranted. PMID:23533637

Deng, Yanping; Teng, Fukang; Chen, Jing; Xue, Song; Kong, Xiangqian; Luo, Cheng; Shen, Xu; Jiang, Hualiang; Xu, Feng; Yang, Wengang; Yin, Jun; Wang, Yanhui; Chen, Hui; Wu, Wanying; Liu, Xuan; Guo, De-an

2013-01-01

376

Salicylate prevents hepatic insulin resistance caused by short-term elevation of free fatty acids in vivo.  

PubMed

Recent evidence indicates that inflammatory pathways are causally involved in insulin resistance. In particular, Ikappa Balpha kinase beta (IKKbeta ), which can impair insulin signaling directly via serine phosphorylation of insulin receptor substrates (IRS) and/or indirectly via induction of transcription of proinflammatory mediators, has been implicated in free fatty acid (FFA)-induced insulin resistance in skeletal muscle. However, it is unclear whether liver IKKbeta activation plays a causal role in hepatic insulin resistance caused by acutely elevated FFA. In the present study, we wished to test the hypothesis that sodium salicylate, which inhibits IKKbeta , prevents hepatic insulin resistance caused by short-term elevation of FFA. To do this, overnight-fasted Wistar rats were subject to 7-h i.v. infusion of either saline or Intralipid plus 20 U/ml heparin (IH; triglyceride emulsion that elevates FFA levels in vivo) with or without salicylate. Hyperinsulinemic-euglycemic clamp with tracer infusion was performed to assess insulin-induced stimulation of peripheral glucose utilization and suppression of endogenous glucose production (EGP). Infusion of IH markedly decreased (P < 0.05) insulin-induced stimulation of peripheral glucose utilization and suppression of EGP, which were completely prevented by salicylate co-infusion. Furthermore, salicylate reversed IH-induced 1) decrease in Ikappa Balpha content; 2) increase in serine phosphorylation of IRS-1 (Ser 307) and IRS-2 (Ser 233); 3) decrease in tyrosine phosphorylation of IRS-1 and IRS-2; and 4) decrease in serine 473-phosphorylated Akt in the liver. These results demonstrate that inhibition of IKKbeta prevents FFA-induced impairment of hepatic insulin signaling, thus implicating IKKbeta as a causal mediator of hepatic insulin resistance caused by acutely elevated plasma FFA. PMID:17951543

Park, Edward; Wong, Victor; Guan, Xinyu; Oprescu, Andrei I; Giacca, Adria

2007-11-01

377

Identifying calcium sources at an acid deposition-impacted spruce forest: A strontium isotope, alkaline earth element multi-tracer approach  

USGS Publications Warehouse

Depletion of calcium from forest soils has important implications for forest productivity and health. Ca is available to fine feeder roots from a number of soil organic and mineral sources, but identifying the primary source or changes of sources in response to environmental change is problematic. We used strontium isotope and alkaline earth element concentration ratios of trees and soils to discern the record of Ca sources for red spruce at a base-poor, acid deposition-impacted watershed. We measured 87Sr/86Sr and chemical compositions of cross-sectional stemwood cores of red spruce, other spruce tissues and sequential extracts of co-located soil samples. 87Sr/86Sr and Sr/Ba ratios together provide a tracer of alkaline earth element sources that distinguishes the plant-available fraction of the shallow organic soils from those of deeper organic and mineral soils. Ca/Sr ratios proved less diagnostic, due to within-tree processes that fractionate these elements from each other. Over the growth period from 1870 to 1960, 87Sr/86Sr and Sr/Ba ratios of stemwood samples became progressively more variable and on average trended toward values that considered together are characteristic of the uppermost forest floor. In detail the stemwood chemistry revealed an episode of simultaneous enhanced uptake of all alkaline earth elements during the growth period from 1930 to 1960, coincident with reported local and regional increases in atmospheric inputs of inorganic acidity. We attribute the temporal trends in stemwood chemistry to progressive shallowing of the effective depth of alkaline earth element uptake by fine roots over this growth period, due to preferential concentration of fine roots in the upper forest floor coupled with reduced nutrient uptake by roots in the lower organic and upper mineral soils in response to acid-induced aluminum toxicity. Although both increased atmospheric deposition and selective weathering of Ca-rich minerals such as apatite provide possible alternative explanations of aspects of the observed trends, the chemical buffering capacity of the forest floor-biomass pool limits their effectiveness as causal mechanisms. ?? Springer 2005.

Bullen, T.D.; Bailey, S.W.

2005-01-01

378

Responsiveness of voltage-gated calcium channels in SH-SY5Y human neuroblastoma cells on quasi-three-dimensional micropatterns formed with poly (l-lactic acid)  

PubMed Central

Introduction In this study, quasi-three-dimensional (3D) microwell patterns were fabricated with poly (l-lactic acid) for the development of cell-based assays, targeting voltage-gated calcium channels (VGCCs). Methods and materials SH-SY5Y human neuroblastoma cells were interfaced with the microwell patterns and found to grow as two dimensional (2D), 3D, and near two dimensional (N2D), categorized on the basis of the cells’ location in the pattern. The capability of the microwell patterns to support 3D cell growth was evaluated in terms of the percentage of the cells in each growth category. Cell spreading was analyzed in terms of projection areas under light microscopy. SH-SY5Y cells’ VGCC responsiveness was evaluated with confocal microscopy and a calcium fluorescent indicator, Calcium Green™-1. The expression of L-type calcium channels was evaluated using immunofluorescence staining with DM-BODIPY. Results It was found that cells within the microwells, either N2D or 3D, showed more rounded shapes and less projection areas than 2D cells on flat poly (l-lactic acid) substrates. Also, cells in microwells showed a significantly lower VGCC responsiveness than cells on flat substrates, in terms of both response magnitudes and percentages of responsive cells, upon depolarization with 50 mM K+. This lower VGCC responsiveness could not be explained by the difference in L-type calcium channel expression. For the two patterns addressed in this study, N2D cells consistently exhibited an intermediate value of either projection areas or VGCC responsiveness between those for 2D and 3D cells, suggesting a correlative relation between cell morphology and VGCC responsiveness. Conclusion These results suggest that the pattern structure and therefore the cell growth characteristics were critical factors in determining cell VGCC responsiveness and thus provide an approach for engineering cell functionality in cell-based assay systems and tissue engineering scaffolds. PMID:23319861

Wu, Ze-Zhi; Wang, Zheng-Wei; Zhang, Li-Guang; An, Zhi-Xing; Zhong, Dong-Huo; Huang, Qi-Ping; Luo, Mei-Rong; Liao, Yan-Jian; Jin, Liang; Li, Chen-Zhong; Kisaalita, William S

2013-01-01

379

Sperm abnormalities in heterozygous acid sphingomyelinase knockout mice reveal a novel approach for the prevention of genetic diseases.  

PubMed

Acid sphingomyelinase knockout mice are a model of the inherited human disorder types A and B Niemann-Pick disease. Herein, we show that heterozygous (ASMKO(+/-)) mice have two distinct sperm populations resembling those found in normal and mutant animals, respectively, and that these two populations could be distinguished by their morphology, ability to undergo capacitation or the acrosome reaction, and/or mitochondrial membrane potential (MMP). The abnormal morphology of the mutant sperm could be normalized by demembranation with detergents or by the addition of recombinant acid sphingomyelinase to the culture media, and the corrected sperm also had an enhanced fertilization capacity. Methods were then explored to enrich for normal sperm from the mixed ASMKO(+/-) population, and flow cytometric sorting based on MMP provided the best results. In vitro fertilization was performed using ASMKO(+/-) oocytes and sperm before and after MMP sorting, and it was found that the sorted sperm produced significantly more wild-type pups than nonsorted sperm. Sperm sorting is much less invasive and more cost-effective than egg isolation, and offers several advantages over the existing assisted reproduction options for Niemann-Pick disease carrier couples. It therefore could have a major impact on the prevention of this and perhaps other genetic diseases. PMID:17525274

Butler, Avigdor; Gordon, Ronald E; Gatt, Shimon; Schuchman, Edward H

2007-06-01

380

Prevention of cardiolipin oxidation and fatty acid cycling as two antioxidant mechanisms of cationic derivatives of plastoquinone (SkQs).  

PubMed

The present state of the art in studies on the mechanisms of antioxidant activities of mitochondria-targeted cationic plastoquinone derivatives (SkQs) is reviewed. Our experiments showed that these compounds can operate as antioxidants in two quite different ways, i.e. (i) by preventing peroxidation of cardiolipin [Antonenko et al., Biochemistry (Moscow) 73 (2008) 1273-1287] and (ii) by fatty acid cycling resulting in mild uncoupling that inhibits the formation of reactive oxygen species (ROS) in mitochondrial State 4 [Severin et al. Proc. Natl. Acad. Sci. USA 107 (2009), 663-668]. The quinol and cationic moieties of SkQ are involved in cases (i) and (ii), respectively. In case (i) SkQH2 interrupts propagation of chain reactions involved in peroxidation of unsaturated fatty acid residues in cardiolipin, the formed SkQ- being reduced back to SkQH2 by heme bH of complex III in an antimycin-sensitive way. Molecular dynamics simulation showed that there are two stable conformations of SkQ1 with the quinol residue localized near peroxyl radicals at C9 or C13 of the linoleate residue in cardiolipin. In mechanism (ii), fatty acid cycling mediated by the cationic SkQ moiety is involved. It consists of (a) transmembrane movement of the fatty acid anion/SkQ cation pair and (b) back flows of free SkQ cation and protonated fatty acid. The cycling results in a protonophorous effect that was demonstrated in planar phospholipid membranes and liposomes. In mitochondria, the cycling gives rise to mild uncoupling, thereby decreasing membrane potential and ROS generation coupled to reverse electron transport in the respiratory chain. In yeast cells, dodecyltriphenylphosphonium (capital ES, Cyrillic12TPP), the cationic part of SkQ1, induces uncoupling that is mitochondria-targeted since capital ES, Cyrillic12TPP is specifically accumulated in mitochondria and increases the H+ conductance of their inner membrane. The conductance of the outer cell membrane is not affected by capital ES, Cyrillic12TPP. PMID:20307489

Skulachev, Vladimir P; Antonenko, Yury N; Cherepanov, Dmitry A; Chernyak, Boris V; Izyumov, Denis S; Khailova, Ludmila S; Klishin, Sergey S; Korshunova, Galina A; Lyamzaev, Konstantin G; Pletjushkina, Olga Yu; Roginsky, Vitaly A; Rokitskaya, Tatiana I; Severin, Fedor F; Severina, Inna I; Simonyan, Ruben A; Skulachev, Maxim V; Sumbatyan, Natalia V; Sukhanova, Evgeniya I; Tashlitsky, Vadim N; Trendeleva, Tatyana A; Vyssokikh, Mikhail Yu; Zvyagilskaya, Renata A

2010-01-01

381

Fusarium head blight control and prevention of mycotoxin contamination in wheat with botanicals and tannic acid.  

PubMed

Suspensions or solutions with 1% of Chinese galls (Galla chinensis, GC) or 1% of tannic acid (TA), inhibited germination of conidia or mycelium growth of Fusarium graminearum (FG) by 98%-100% or by 75%-80%, respectively, whereas dried bark from buckthorn (Frangula alnus, FA) showed no effect at this concentration. In climate chamber experiments where the wheat variety "Apogee" was artificially inoculated with FG and F. crookwellense (FCr) and treated with 5% suspensions of TA, GC and FA, the deoxynivalenol (DON) content in grains was reduced by 81%, 67% and 33%, respectively. In field experiments with two commercial wheat varieties and artificial or semi-natural inoculations, mean DON reductions of 66% (TA) and 58% (FA), respectively, were obtained. Antifungal toxicity can explain the high efficacies of TA and GC but not those of FA. The Fusarium head blight (FHB) and mycotoxin reducing effect of FA is probably due to elicitation of resistance in wheat plants. With semi-natural inoculation, a single FA application in the first half of the flowering period performed best. However, we assume that applications of FA at the end of ear emergence and a treatment, triggered by an infection period, with TA or GC during flowering, might perform better than synthetic fungicides. PMID:24577585

Forrer, Hans-Rudolf; Musa, Tomke; Schwab, Fabienne; Jenny, Eveline; Bucheli, Thomas D; Wettstein, Felix E; Vogelgsang, Susanne

2014-03-01

382

Fusarium Head Blight Control and Prevention of Mycotoxin Contamination in Wheat with Botanicals and Tannic Acid  

PubMed Central

Suspensions or solutions with 1% of Chinese galls (Galla chinensis, GC) or 1% of tannic acid (TA), inhibited germination of conidia or mycelium growth of Fusarium graminearum (FG) by 98%–100% or by 75%–80%, respectively, whereas dried bark from buckthorn (Frangula alnus, FA) showed no effect at this concentration. In climate chamber experiments where the wheat variety “Apogee” was artificially inoculated with FG and F. crookwellense (FCr) and treated with 5% suspensions of TA, GC and FA, the deoxynivalenol (DON) content in grains was reduced by 81%, 67% and 33%, respectively. In field experiments with two commercial wheat varieties and artificial or semi-natural inoculations, mean DON reductions of 66% (TA) and 58% (FA), respectively, were obtained. Antifungal toxicity can explain the high efficacies of TA and GC but not those of FA. The Fusarium head blight (FHB) and mycotoxin reducing effect of FA is probably due to elicitation of resistance in wheat plants. With semi-natural inoculation, a single FA application in the first half of the flowering period performed best. However, we assume that applications of FA at the end of ear emergence and a treatment, triggered by an infection period, with TA or GC during flowering, might perform better than synthetic fungicides. PMID:24577585

Forrer, Hans-Rudolf; Musa, Tomke; Schwab, Fabienne; Jenny, Eveline; Bucheli, Thomas D.; Wettstein, Felix E.; Vogelgsang, Susanne

2014-01-01

383

Electroaddressing of Cell Populations by Co-Deposition with Calcium Alginate Hydrogels  

E-print Network

solubilize calcium ions from insoluble calcium carbonate. The solubilized Ca2þ can then bind alginateElectroaddressing of Cell Populations by Co-Deposition with Calcium Alginate Hydrogels By Xiao is an acidic polysaccharide that forms a gel in the presence of calcium ions. Calcium alginate gels are widely

Rubloff, Gary W.

384

Calcium partitioning and allocation and blossom-end rot development in tomato plants in response to whole-plant and fruit-specific abscisic acid treatments  

PubMed Central

The mechanisms regulating Ca2+ partitioning and allocation in plants and fruit remain poorly understood. The objectives of this study were to determine Ca2+ partitioning and allocation in tomato plants and fruit in response to whole-plant and fruit-specific abscisic acid (ABA) treatments, as well as to analyse the effect of changes in Ca2+ partitioning and allocation on fruit susceptibility to the Ca2+ deficiency disorder blossom-end rot (BER) under water stress conditions. Tomato plants of the cultivar Ace 55 (Vf) were grown in a greenhouse and exposed to low Ca2+ conditions during fruit growth and development. Starting 1 day after pollination (DAP), the following treatments were initiated: (i) whole plants were sprayed weekly with deionized water (control) or (ii) with 500mg l?1 ABA; or fruit on each plant were dipped weekly (iii) in deionized water (control) or (iv) in 500mg l?1 ABA. At 15 DAP, BER was completely prevented by whole-plant or fruit-specific ABA treatments, whereas plants or fruit treated with water had 16–19% BER incidence. At 30 DAP, BER was prevented by the whole-plant ABA treatment, whereas fruit dipped in ABA had a 16% and water-treated plants or fruit had a 36–40% incidence of BER. The results showed that spraying the whole plant with ABA increases xylem sap flow and Ca2+ movement into the fruit, resulting in higher fruit tissue and water-soluble apoplastic Ca2+ concentrations that prevent BER development. Although fruit-specific ABA treatment had no effect on xylem sap flow rates or Ca2+ movement into the fruit, it increased fruit tissue water-soluble apoplastic Ca2+ concentrations and reduced fruit susceptibility to BER to a lesser extent. PMID:24220654

Tonetto de Freitas, Sergio

2014-01-01

385

Preventing protein oxidation with sugars: scavenging of hypohalous acids by 5-selenopyranose and 4-selenofuranose derivatives.  

PubMed

Heme peroxidases including myeloperoxidase (MPO) are released at sites of inflammation by activated leukocytes. MPO generates hypohalous acids (HOX, X = Cl, Br, SCN) from H(2)O(2); these oxidants are bactericidal and are key components of the inflammatory response. However, excessive, misplaced or mistimed production can result in host tissue damage, with this implicated in multiple inflammatory diseases. We report here methods for the conversion of simple monosaccharide sugars into selenium- and sulfur-containing species that may act as potent water-soluble scavengers of HOX. Competition kinetic studies show that the seleno species react with HOCl with rate constants in the range 0.8-1.0 × 10(8) M(-1) s(-1), only marginally slower than those for the most susceptible biological targets including the endogenous antioxidant, glutathione. The rate constants for the corresponding sulfur-sugars are considerably slower (1.4-1.9 × 10(6) M(-1) s(-1)). Rate constants for reaction of the seleno-sugars with HOBr are ~8 times lower than those for HOCl (1.0-1.5 × 10(7) M(-1) s(-1)). These values show little variation with differing sugar structures. Reaction with HOSCN is slower (~10(2) M(-1) s(-1)). The seleno-sugars decreased the extent of HOCl-mediated oxidation of Met, His, Trp, Lys, and Tyr residues, and 3-chlorotyrosine formation, on both isolated bovine serum albumin and human plasma proteins, at concentrations as low as 50 ?M. These studies demonstrate that novel selenium (and to a lesser extent, sulfur) derivatives of monosaccharides could be potent modulators of peroxidase-mediated damage at sites of acute and chronic inflammation, and in multiple human pathologies. PMID:23075063

Storkey, Corin; Pattison, David I; White, Jonathan M; Schiesser, Carl H; Davies, Michael J

2012-11-19

386

meso-2,3-Dimercaptosuccinic acid and prevention of arsenite embryotoxicity and teratogenicity in the mouse.  

PubMed

meso-2,3-Dimercaptosuccinic acid (DMSA), an antidote for the treatment of experimental and human poisoning by a number of heavy metals, has been reported to reduce the lethality of animals poisoned with arsenic more effectively than 2,3-dimercaptopropanol. In the present study, the effect of DMSA on arsenite-induced embryotoxic and teratogenic effects was evaluated in mice. In a first experiment, a series of four DMSA injections was administered sc to pregnant Swiss mice immediately after a single ip injection of 12 mg/kg of sodium arsenite (NaAsO2) given on Day 10 of gestation, and at 24, 48, and 72 hr thereafter. DMSA effectiveness was assessed at dosage levels of 0, 80, 160, and 320 mg/kg/day. Treatment with DMSA significantly reduced the embryolethality and the incidence of gross external and skeletal malformations and variations provoked by NaAsO2. Based on these findings, the effect of increasing the time interval between acute arsenite exposure and initiation of DMSA therapy was investigated in a second experiment. On Day 10 of gestation, DMSA (320 mg/kg) was administered sc to pregnant mice at 0, 0.25, 0.50, 1, 4, or 12 hr after a 12-mg/kg ip dose of NaAsO2. Embryotoxicity and teratogenicity derived from NaAsO2 exposure were significantly reduced when DMSA was given during the first hour after NaAsO2 injection. According to these results, a delay between acute arsenite intoxication and DMSA treatment should be avoided to have a practical beneficial effect on the arsenite exposed conceptus. PMID:1662650

Domingo, J L; Bosque, M A; Piera, V

1991-08-01

387

Assessment of tailor-made prevention of atherosclerosis with folic acid supplementation: randomized, double-blind, placebo-controlled trials in each MTHFR C677T genotype  

Microsoft Academic Search

This study aimed at assessing the effect of folic acid supplementation quantitatively in each MTHFR C677T genotype and considered the efficiency of tailor-made prevention of atherosclerosis. Study design was genotype-stratified, randomized, double-blind, placebo-controlled trials. The setting was a Japanese company in the chemical industry. Subjects were 203 healthy men after exclusion of those who took folic acid or drugs known

Koichi Miyaki; Mitsuru Murata; Haruhito Kikuchi; Izumi Takei; Takeo Nakayama; Kiyoaki Watanabe; Kazuyuki Omae

2005-01-01

388

Differential gene expression for glutamic acid decarboxylase and type II calcium-calmodulin-dependent protein kinase in basal ganglia, thalamus, and hypothalamus of the monkey  

SciTech Connect

In situ hybridization histochemistry, using cRNA probes, revealed a complementarity in the distributions of cells in the basal ganglia, basal nucleus of Meynert, thalamus, hypothalamus, and rostral part of the midbrain that showed gene expression for glutamic acid decarboxylase (GAD) or the alpha-subunit of type II calcium-calmodulin-dependent protein kinase (CAM II kinase-alpha). Cells in certain nuclei such as the thalamic reticular nucleus, globus pallidus, and pars reticulata of the substantia nigra show GAD gene expression only; others in nuclei such as the basal nucleus of Meynert, medial mamillary nuclei, and ventromedial hypothalamic nuclei show CAM II kinase-alpha gene expression only. A few nuclei, for example, the pars compacta of the substantia nigra and the greater part of the subthalamic nucleus, display gene expression for neither GAD nor CAM II kinase-alpha. In other nuclei, notably those of the dorsal thalamus, and possibly in the striatum, GAD- and CAM II kinase-expressing cells appear to form two separate populations that, in most thalamic nuclei, together account for the total cell population. In situ hybridization reveals large amounts of CAM II kinase-alpha mRNA in the neuropil of most nuclei containing CAM II kinase-alpha-positive cells, suggesting its association with dendritic polyribosomes. The message may thus be translated at those sites, close to the synapses with which the protein is associated. The in situ hybridization results, coupled with those from immunocytochemical staining for CAM II kinase-alpha protein, indicate that CAM II kinase-alpha is commonly found in certain non-GABAergic afferent fiber systems but is not necessarily present in the postsynaptic cells on which they terminate. It appears to be absent from most GABAergic fiber systems but can be present in the cells on which they terminate.

Benson, D.L.; Isackson, P.J.; Hendry, S.H.; Jones, E.G. (Department of Anatomy, University of California, Irvine (USA))

1991-06-01

389

Hypothermia and Pharmacological Regimens that Prevent Overexpression and Overactivity of the Extracellular Calcium-Sensing Receptor Protect Neurons against Traumatic Brain Injury  

PubMed Central

Abstract Traumatic brain injury (TBI) leads to acute functional deficit in the brain. Molecular events underlying TBI remain unclear. In mouse brains, we found controlled cortical impact (CCI) injury induced overexpression of the extracellular calcium-sensing receptor (CaSR), which is known to stimulate neuronal activity and accumulation of intracellular Ca2+ and concurrent down-regulation of type B or metabotropic GABA receptor 1 (GABA-B-R1), a prominent inhibitory pathway in the brain. These changes in protein expression preceded and were closely associated with the loss of brain tissue, as indicated by the increased size of cortical cavity at impact sites, and the development of motor deficit, as indicated by the increased frequency of right-biased swing and turn in the CCI mice. Mild hypothermia, an established practice of neuroprotection for brain ischemia, partially but significantly blunted all of the above effects of CCI. Administration of CaSR antagonist NPS89636 mimicked hypothermia to reduce loss of brain tissue and motor functions in the CCI mice. These data together support the concept that CaSR overexpression and overactivity play a causal role in potentiating TBI potentially by stimulating excitatory neuronal responses and by interfering with inhibitory GABA-B-R signaling and that the CaSR could be a novel target for neuroprotection against TBI. PMID:23360235

Kim, Jong Youl; Kim, Nuri

2013-01-01

390

The development and effectiveness of an osteoporosis prevention education intervention .  

E-print Network

??Osteoporosis prevention education interventions intended to increase the osteoporosis preventive behaviors of weight-bearing physical activity and calcium consumption in young individuals have been found to… (more)

Nguyen, Vu H.

2011-01-01

391

Nuclear calcium signaling.  

PubMed

Calcium is the major intracellular messenger linking synaptic activity in neurons to gene expression to control diverse functions including adaptive responses to synaptic activity as well as survival and death (Bading et al. 1993; Hardingham et al. 1997; Chawla and Bading 2001; West et al. 2001; Zhang et al. 2007; Flavell and Greenberg 2008; Mellstrom et al. 2008; Redmond 2008; Wayman et al. 2008; Bootman et al. 2009; Zhang et al. 2009; Hardingham and Bading 2010). Calcium entry at the synapse acts locally to activate signaling cascades which regulate posttranslational modifications essential for synaptic plasticity, such as the insertion of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) into the postsynaptic membrane (Soderling 2000; Malinow and Malenka 2002; Ehrlich and Malinow 2004). Synaptic activity can also evoke calcium signals in the nucleus which regulate gene pools largely through the phosphorylation of cAMP response element-binding protein (CREB) and its coactivator, CREB-binding protein (CBP) (Bading et al. 1993; Hardingham et al. 1997; Hardingham et al. 1999; Hu et al. 1999; Hardingham et al. 2001b; Impey et al. 2002; Zhang et al. 2009). Distinct mechanisms have been proposed to mediate synaptically generated calcium signals in subcompartments of pyramidal neurons; N-methyl-D -aspartate receptors (NMDARs) and ryanodine receptors have been implicated in the spine, inositol 3,4,5 triphosphate (IP3) receptors in the dendrites, and L-type voltage-gated calcium channels (VGCCs) at the soma and nucleus, although both NMDARs and IP3 receptors can also contribute to somatic and nuclear calcium signals under certain stimulation conditions (Nakamura et al. 1999; Bardo et al. 2006; Raymond and Redman 2006; Watanabe et al. 2006; Hong and Ross 2007; Hagenston et al. 2008; Bengtson et al. 2010). We review here the calcium signaling pathways underlying synaptically activated gene transcription leading to long-lasting changes in synaptic efficacy and memory as well as the physiological mechanisms by which synaptic activity evokes nuclear calcium signals. PMID:22351065

Bengtson, C Peter; Bading, Hilmar

2012-01-01

392

Omega 3 fatty acids for prevention and treatment of cardiovascular disease  

PubMed Central

Background It has been suggested that omega 3 (W3, n-3 or omega-3) fats from oily fish and plants are beneficial to health. Objectives To assess whether dietary or supplemental omega 3 fatty acids alter total mortality, cardiovascular events or cancers using both RCT and cohort studies. Search methods Five databases including CENTRAL, MEDLINE and EMBASE were searched to February 2002. No language restrictions were applied. Bibliographies were checked and authors contacted. Selection criteria RCTs were included where omega 3 intake or advice was randomly allocated and unconfounded, and study duration was at least six months. Cohorts were included where a cohort was followed up for at least six months and omega 3 intake estimated. Data collection and analysis Studies were assessed for inclusion, data extracted and quality assessed independently in duplicate. Random effects meta-analysis was performed separately for RCT and cohort data. Main results Forty eight randomised controlled trials (36,913 participants) and 41 cohort analyses were included. Pooled trial results did not show a reduction in the risk of total mortality or combined cardiovascular events in those taking additional omega 3 fats (with significant statistical heterogeneity). Sensitivity analysis, retaining only studies at low risk of bias, reduced heterogeneity and again suggested no significant effect of omega 3 fats. Restricting analysis to trials increasing fish-based omega 3 fats, or those increasing short chain omega 3s, did not suggest significant effects on mortality or cardiovascular events in either group. Subgroup analysis by dietary advice or supplementation, baseline risk of CVD or omega 3 dose suggested no clear effects of these factors on primary outcomes. Neither RCTs nor cohorts suggested increased relative risk of cancers with higher omega 3 intake but estimates were imprecise so a clinically important effect could not be excluded. Authors’ conclusions It is not clear that dietary or supplemental omega 3 fats alter total mortality, combined cardiovascular events or cancers in people with, or at high risk of, cardiovascular disease or in the general population. There is no evidence we should advise people to stop taking rich sources of omega 3 fats, but further high quality trials are needed to confirm suggestions of a protective effect of omega 3 fats on cardiovascular health. There is no clear evidence that omega 3 fats differ in effectiveness according to fish or plant sources, dietary or supplemental sources, dose or presence of placebo. PMID:15495044

Hooper, Lee; Harrison, Roger A; Summerbell, Carolyn D; Moore, Helen; Worthington, Helen V; Ness, Andrew; Capps, Nigel; Smith, George Davey; Riemersma, Rudolph; Ebrahim, Shah

2014-01-01

393

Project Calcium  

SciTech Connect

Fouling problems in utility boilers have been classified into two principal types: high-temperature and low-temperature fouling. A multiclient-sponsored program was initiated at the Energy and Environmental Research Center (EERC) to better understand the causes of low-temperature fouling when burning high-calcium western US coals. The goals of Project Calcium were to define the low-temperature deposition problem, identify the calcium-based components that are responsible for the formation of the deposits, develop ways to predict their formation, and identify possible methods to mitigate the formation of these deposits. To achieve the goals of Project Calcium, detailed sampling of utility boilers and laboratory-scale studies coupled with state-of-the-art methods to determine the inorganic components in coals and coal ash-derived materials were conducted. Boiler Sampling was also performed. The work involved sampling coal, entrained ash, deposits and slags from five full-scale utility boilers combined with detailed advanced characterization of the materials. The results of this work aided in identifying the key phenomena to focus the laboratory studies and in model verification. Field testing was conducted at three utilities.

Hurley, J.P.; Benson, S.A.; Erickson, T.A.; Allan, S.E.; Bieber, J.

1992-09-01

394

Rosuvastatin calcium  

Microsoft Academic Search

Rosuvastatin calcium (Crestor; AstraZeneca), the seventh drug in the statin class, was approved by the US FDA in August 2003 for the reduction of cholesterol levels in patients with hypercholesterolaemia. Billed as the most potent statin available, can it overcome initial setbacks and make a significant impact in the multi-billion-dollar market for cholesterol-lowering drugs?

Mark Thornton; Peter Kirkpatrick; Jeremy Quirk

2003-01-01

395

Prevention of Acid Mine Drainage Through Complexation of Ferric Iron by Soluble Microbial Growth Products  

NASA Astrophysics Data System (ADS)

Acid mine drainage (AMD) is a widespread environmental problem with deleterious impacts on water quality in streams and watersheds. AMD is generated largely by the oxidation of metal sulfides (i.e. pyrite) by ferric iron. This abiotic reaction is catalyzed by conversion of ferrous to ferric iron by iron and sulfur oxidizing microorganisms. Biostimulation is currently being investigated as an attempt to inhibit the oxidation of pyrite and growth of iron oxidizing bacteria through addition of organic carbon. This may stimulate growth of indigenous communities of acidophilic heterotrophic bacteria to compete for oxygen. The goal of this research is to investigate a secondary mechanism associated with carbon addition: complexation of free Fe(III) by soluble microbial growth products (SMPs) produced by microorganisms growing in waste rock. Exploratory research at the laboratory scale examined the effect of soluble microbial products (SMPs) on the kinetics of oxidation of pure pyrite during shaker flask experiments. The results confirmed a decrease in the rate of pyrite oxidation that was dependent upon the concentration of SMPs in solution. We are using these data to verify results from a pyrite oxidation model that accounts for SMPs. This reactor model involves differential-algebraic equations incorporating total component mass balances and mass action laws for equilibrium reactions. Species concentrations determined in each time step are applied to abiotic pyrite oxidation rate expressions from the literature to determine the evolution of total component concentrations. The model was embedded in a parameter estimation algorithm to determine the reactive surface area of pyrite in an abiotic control experiment, yielding an optimized value of 0.0037 m2. The optimized model exhibited similar behavior to the experiment for this case; the root mean squared of residuals for Fe(III) was calculated to be 7.58 x 10-4 M, which is several orders of magnitude less than the actual Fe(III) concentrations. The model was refined to include Fe(III)-SMP complexes, but these are not well documented and vary depending upon the nature and origin of the growth products. Well known chelating agents form predictable complexes with Fe(III) iron through documented complexation reactions. If chelation of soluble Fe(III) by SMPs is similar to such a chelator, the latter may be used as a basis to parameterize inhibition of pyrite oxidation due to complexation of Fe(III) by SMPs. Fe(III)