oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 6 )

2018 ( 52 )

2017 ( 58 )

2016 ( 56 )

Custom range...

Search Results: 1 - 10 of 3160 matches for " calcium "
All listed articles are free for downloading (OA Articles)
Page 1 /3160
Display every page Item
Amorphous Calcium Salt Composition Bioavailability Evaluation in Chickens  [PDF]
D. Babarykin, M. Mutalova, G. Smirnova, S. Vasiljeva, G. Krumina, N. Basova, V. Agejchenko, R. Simanis
Journal of Biosciences and Medicines (JBM) , 2019, DOI: 10.4236/jbm.2019.72002
Abstract: Despite the market saturation with a wide range of calcium preparations in dietary supplements as well as in pharmaceuticals, calcium product safety and efficacy remain an item for further optimization. Bones and teeth mainly consist of calcium phosphate, but tablets and capsules are predominantly produced from calcium carbonate. On the other hand, in human food Ca2+ is bound with a lot of anions—carbonates, sulphates, chlorides, phosphates, citrates, oxalates etc. It seems that traditional calcium formulations due its low bioavailability cannot provide all spectra of biological calcium-dependant effects and dietary calcium might be safer and more effective than traditional calcium supplements and medicines. To increase calcium salt efficacy a new formulation of calcium salts has been developed. It is a mixture (water suspension) of amorphous calcium carbonate, citrate, hydrocarbonate, as well as magnesium hydrocarbonate and hydrocitrate as stabilizers. The capacity of a cockerel’s duodenal mucosa to absorb Ca2+ after peroral ingestion of the mentioned composition in vivo was as much as 126% higher in comparison with CaCO3 suspension intake. Vitamin D3 enhanced the amorphous antirachitic activity of calcium salts. The aim of the study was to compare original amorphous calcium salt composition bioavailability with Ca salts most often in food and medicines, as well as to evaluate the antirachitic activity of the mentioned composition in combination with vitamin D3 in chickens.
Pharmacological evaluation of catalepsy in low calcium and/or magnesium deficient feeding mice  [PDF]
Osamu Nakagawasai, Ryoo Taniguchi, Koichi Tan-No, Fumihiro Yamadera, Wataru Nemoto, Fukie Yaoita, Takeshi Tadano
Health (Health) , 2012, DOI: 10.4236/health.2012.431172
Abstract: Populations from the Kii peninsula of Japan and Guam present a high incidence of amyotrophic lateral sclerosis and parkinsonism-dementia complex. It is thought that the low levels of calcium (Ca) and magnesium (Mg) in the drinking water are involved in the pathogenesis of these diseases. The present study aimed to test the hypothesis that catalepsy, a behavioral immobility and one of the Parkinsonian symptoms, may result from functionally impaired dopaminergic neurons in low Ca and Mg (LCa/Mg) fed mice. A group of mice fed with an LCa/Mg diet for 6 weeks was compared to a control group on a standard diet. Cataleptic symptoms such as akinesia and rigidity were measured using the bar test. The antiparkinsonian drugs dopamine (DA) precursor L-3, 4-dihydroxy phenylamine (L-DOPA), the selective DA receptor D2 agonist bromocriptine and the DA releaser amantadine were tested for their effects on the induced catalepsy. Mice developped catalepsy after 3 weeks on the LCa/Mg diet. LCa/Mg diet-induced catalepsy was improved by the administration of either L-DOPA (50 - 200 mg/kg i.p.) in combination with benserazide (25 mg/kg i.p.), bromo- criptine (0.25 - 4 mg/kg i.p.) or amantadine (5 - 20 mg/kg i.p.). These results suggest that catalepsy in LCa/Mg mice might result from a hypofunction of dopaminergic neurons. Moreover, our results support the hypothesis that LCa/Mg in-take may be one etiological factor in neurodegenerative disorders including Parkinson’s disease.
Effect of Calcium Consumption on the Spasticity in the Spastic Rats  [PDF]
Marina Indriasari, ? Hardinsyah, Lilik Kustiyah, Bambang Pontjo Priosoeryanto, Ferial Hadipoetro Idris
Food and Nutrition Sciences (FNS) , 2019, DOI: 10.4236/fns.2019.101004
Abstract: Spasticity is a stiff muscle condition because the muscles receive impulses continuously. Calcium ions play a role in the ability of nerves to stimulate muscle contraction. This study aimed to analyze the effect of calcium consumption on the changes of spasticity and the relation of calcium levels in the blood and muscle to the spasticity. The experimental study was conducted on 42 male Sprague-Dawley rats aged 12 - 14 weeks. The 15-d intervention was conducted on six groups of spastic rats by administering 20 g of feed containing 50 mg, 100 mg, and 200 mg of calcium, it also received 100 mg, 200 mg, and 300 mg of calcium lactate supplementation. The experimental rats were induced with 80 mg/kg BW of Erythrocin B through the tail vein to make them spastic. This study showed a tendency of increased spasticity along with the increased dose of calcium given to the subjects. There were significant differences (p = 0.007) in changes in spasticity between groups. The significant differences (p = 0.02) in changes in blood calcium levels. The Spearman’s correlations test on the changes in blood calcium levels and changes in spasticity showed a positive coefficient correlation (r = 0.097) with a p-value of 0.54. An increase in blood calcium levels and a large decrease in spasticity were found in the group receiving 100 mg calcium intake in 20 g of feed. The calcium levels in muscles had a significant correlation with spasticity (p = 0.038, r = 0.810). The calcium levels in the muscle had a strong correlation with blood calcium levels (p = 0.041, r = 0.748). The biggest decrease in spasticity occurred after 100 mg of calcium were given to the rats for 15 days, and it was considered as an optimal dose. The calcium levels in the muscles had a strong correlation with blood calcium levels and the spasticity of the spastic rats.
The role of intracellular sodium (Na+) in the regulation of calcium (Ca2+)-mediated signaling and toxicity  [PDF]
Xian-Min Yu, Bradley R. Groveman, Xiao-Qian Fang, Shuang-Xiu Lin
Health (Health) , 2010, DOI: 10.4236/health.2010.21002
Abstract: It is known that activated N-methyl-D-aspartate receptors (NMDARs) are a major route of ex-cessive calcium ion (Ca2+) entry in central neu-rons, which may activate degradative processes and thereby cause cell death. Therefore, NMD- ARs are now recognized to play a key role in the development of many diseases associated with injuries to the central nervous system (CNS). However, it remains a mystery how NMDAR ac-tivity is recruited in the cellular processes leading to excitotoxicity and how NMDAR activ-ity can be controlled at a physiological level. The sodium ion (Na+) is the major cation in ex-tracellular space. With its entry into the cell, Na+ can act as a critical intracellular second mes-senger that regulates many cellular functions. Recent data have shown that intracellular Na+ can be an important signaling factor underlying the up-regulation of NMDARs. While Ca2+ influx during the activation of NMDARs down-regu-lates NMDAR activity, Na+ influx provides an essential positive feedback mechanism to over- come Ca2+-induced inhibition and thereby po-tentiate both NMDAR activity and inward Ca2+ flow. Extensive investigations have been con-ducted to clarify mechanisms underlying Ca2+- mediated signaling. This review focuses on the roles of Na+ in the regulation of Ca2+-mediated NMDAR signaling and toxicity.
Preparation of Calcium Phosphate with Oyster Shells  [PDF]
Hiroaki Onoda, Hironari Nakanishi
Natural Resources (NR) , 2012, DOI: 10.4236/nr.2012.32011
Abstract: Oyster shells have received attention for use as a calcium resource. For this study, calcium phosphate was prepared from phosphoric acid and oyster shells. The influences of the concentration of phosphoric acid and pH in the preparation conditions were studied from the yields of calcium phosphate and unreacted carbonate, and the Ca/P ratios in precipitates. The yield of calcium phosphate and carbonate was low in the preparation condition with 0.1 mol/l of phosphoric acid. The obtained precipitates were the mixture of calcium hydrogen phosphate dihydrate and the unreacted calcium carbonate. The reactivity of the oyster shells with phosphoric acid was discussed from the yields and Ca/P ratios in precipitates.
Exploiting MCF-7 Cells’ Calcium Dependence with Interlaced Therapy  [PDF]
Jonathan Pottle, Chengrong Sun, Lloyd Gray, Ming Li
Journal of Cancer Therapy (JCT) , 2013, DOI: 10.4236/jct.2013.47A006
Abstract:

The purpose of this study is to demonstrate MCF-7 cells’ dependence on calcium for growth and to exploit that dependence to improve chemotherapy efficacy. Fura-2 fluorescence imaging shows that MCF-7 cells maintain a higher basal intracellular calcium concentration than non-tumorigenic MCF-10A cells. Blocking T-type calcium channels with mibefradil reduced MCF-7 intracellular calcium concentration. Flow cytometry shows that knocking down T-type calcium channel expression with siRNA caused an increase in MCF-7 cells in G1 phase and a decrease in cells in S phase. Proliferation assays of MCF-7 cells treated with EGTA and thapsigargin reveal the dependence of MCF-7 cell growth on extracellular and intracellular calcium sources, respectively. In vitro, interlaced treatment that alternated the T-type calcium channel blocker NNC-55-0396 with paclitaxel more effectively reduced MCF-7 cell number than chemotherapy alone. In a mouse in vivo model, interlaced mibefradil and paclitaxel more effectively reduced MCF-7 xenograft size than chemotherapy alone. These findings indicate that MCF-7 cells are dependent on calcium for proliferation, particularly in passing the G1/S cell cycle checkpoint. Further, this dependence on calcium can be exploited by alternating treatment with T-type calcium channel blockers with paclitaxel in an interlaced therapy scheme that increases the efficacy of the chemotherapy.

Synthesis of CaO-SiO2 Compounds Using Materials Extracted from Industrial Wastes  [PDF]
Nobuaki Yamaguchi, Yoshiko Masuda, Yoshishige Yamada, Hideaki Narusawa, Cho Han-Cheol, Yukimichi Tamaki, Takashi Miyazaki
Open Journal of Inorganic Non-metallic Materials (OJINM) , 2015, DOI: 10.4236/ojinm.2015.51001
Abstract: Mineral trioxide aggregate (MTA) cement is an attractive material in endodontic dentistry. The purpose of this study was to produce calcium silicate, which is a major component of MTA, from waste materials. A dental alginate impression gel and used chalks were selected and mixed in a suitable ratio (Code: EXP). As a control, CaCO3 and a commercial diatomite were used (Code: CON). Each powder was heated to 850C and 1000C, and then kneaded with water. TG-DTA, compressive tests, SEM observations, elemental mapping analyses, and XRD analyses were performed. TG-DTA indicated that weight reduction of CaCO3 started at 600C, and it completely decomposed on heating at 850C. The strength was affected by the temperature. After heating, CaCO3 was transformed into CaO and/or Ca2SiO4, and Ca(OH)2 was formed by mixing with water. There were no differences between EXP and CON. These data suggested that recycled wastes might be promising MTA sources.
Calcium and Oxalate Contents of Curly Leaf ( Petroselinum crispum) and Flat Leaf ( P. crispum var. neapolitanum ) Parsley Cultivars  [PDF]
Geoffrey Savage, Leo Vanhanen
Food and Nutrition Sciences (FNS) , 2015, DOI: 10.4236/fns.2015.616161
Abstract: The total, soluble and insoluble oxalate contents of the leaves and stems of curly leaf (Petroselinum crispum) and flat leaf (P. crispum var. neapolitanum) parsley cultivars were extracted from fresh tissue and measured using HPLC chromatography. There were no significant differences between the total and insoluble oxalate contents of the leaves between the flat leaf and curly leaf cultivars. There was a small difference (P < 0.05) between the soluble oxalate contents of the leaves of the two cultivars. The mean total, soluble and insoluble oxalates of the leaves of the two cultivars were 1137.0, 177.9 and 959.3 mg/100 g dry matter (DM), respectively. The mean total, soluble and insoluble oxalate contents of the stems were 1680.7, 386.2 and 1294.5 mg/100 g DM, respectively, and these were significantly higher than the mean values for the leaves of the two cultivars. Insoluble oxalate made up a mean of 77.0% of the curly leaf stems and leaves compared to a mean of 84.4% found in the flat-leaved cultivar. Unavailable calcium, that is, calcium bound to oxalate as insoluble oxalate, made up a mean of 26.9% of the total calcium in the leaves of both cultivars while the unavailable calcium made up 45.0% of the total calcium in the stems of the two cultivars. Overall, the oxalate contents of both parsley cultivars are relatively high, on a dry matter basis, but their overall contribution to dietary intake is likely to be quite small as parsley is an herb that is only used in small amounts to garnish foods.
Inhibition of calcium oxalate nephrotoxicity with Zamzam water  [PDF]
Saeed S. Al-Ghamdi
Open Journal of Preventive Medicine (OJPM) , 2012, DOI: 10.4236/ojpm.2012.21010
Abstract: Zamzam water is well known of its high conductivity. For this fact urologist and nephrologists recommend their patients who are suffering from kidney stones not to drink this water because it could worse their health status. This study was conducted to investigate the effect of Zamzam water on calcium oxalate nephrotoxicity in experimentally induced kidney stones in male Wistar albino rats. Calcium oxalate crystals were induced by orally administration of 200 mg of glycolic acid dissolved in the drinking water. The rats were divided into three groups; six rats each. These include positive control group (given glycolic acid), test group (given glycolic acid plus Zamzam water) and negative group (given drinking water only). After two weeks of treatment, blood analysis of blood urea nitrogen (BUN) and creatinine showed significant differences in positive control group compared to the negative control group, whereas no significant differences were noticed in the level of BUN and creatinine between both the negative control and the test group. Moreover, urine analysis showed a high density of calcium oxalate crystals in the positive control group, whereas no crystals were detected in the negative control and the test groups. Histopathological investigations showed damaging in kidneys of the positive control group with no tissue abnormalities in the negative control and the test group. I concluded from this study that Zamzam water prevents the formation calcium oxalate stone, which probably mean that it has no negative effect on patients suffering from kidney disorders due to crystals formation.
Study of Calcium and Sodium Behavior to Identify Milk Adulteration Using Flame Atomic Absorption Spectrometry  [PDF]
Poliana M. dos Santos, Lenon F. B. Costa, Edenir R. Pereira-Filho
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.39161
Abstract: A fast and direct method for determination of milk adulteration by monitoring of calcium and sodium concentrations variations was described. Milk samples were furnished by a dairy company located at S?o Carlos (S?o Paulo State, Brazil) and and spiked with tap-water, whey, hydrogen peroxide, synthetic urine, urea and synthetic milk in the ranged from 5% to 50% (v/v), expect for caustic soda. Caustic soda was added in the milk until establish the original pH. The milk samples were analyzed by using flame atomic absorption spectrometry (FAAS) and no acid digestion process was required. Results showed a significant decrease in the Na and Ca concentrations with addition of synthetic milk and tap-water, a nonlinear variation with addition of synthetic urine, whey and hydrogen peroxide and a largest increase in the Na concentration with addition of NaOH. Correlation between Na and Ca concentrations in pure and adulterated milk were evaluated by paired t-test at a 95% confidence level. Results showed that the method proposed is efficient to identify samples adulterated with tap-water, caustic soda, synthetics milk and urine.
Page 1 /3160
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.