WorldWideScience

Sample records for calcium 35

  1. High-normal calcium (1.35 mmol/l) dialysate in patients on CAPD

    DEFF Research Database (Denmark)

    Bro, S; Brandi, L; Olgaard, K

    1996-01-01

    from a dialysate Ca of 1.75 to 1.35 mmol/l, the doses of calcium carbonate and alfacalcidol could be significantly increased. Furthermore, using the dialysate Ca of 1.35 mmol/l made it possible to induce a controlled increase of PTH levels to 80-100 pg/ml by a temporarily discontinuation......-normal plasma P levels could be readily achieved with a minimal risk of incidental hypercalcaemia despite use of calcium carbonate as the main P binder. As a consequence of the tight Ca and P regulation, minimal doses of alfacalcidol were required to keep PTH within acceptable limits. We recommend...... at in dialysis patients in order to suppress the parathyroid hormone secretion. The end-points of the study were (1) plasma ionized calcium (iCa) and phosphate (P) levels, (2) plasma intact parathyroid hormone (PTH) levels, (3) doses of calcium carbonate and alfacalcidol, (4) requirements of Al...

  2. Calcium

    Science.gov (United States)

    ... Turn to calcium-fortified (or "calcium-set") tofu, soy milk, tempeh, soy yogurt, and cooked soybeans (edamame). Calcium-fortified foods. Look for calcium-fortified orange juice, soy or rice milk, breads, and cereal. Beans. You can get decent ...

  3. Deciphering ligand specificity of a Clostridium thermocellum family 35 carbohydrate binding module (CtCBM35 for gluco- and galacto- substituted mannans and its calcium induced stability.

    Directory of Open Access Journals (Sweden)

    Arabinda Ghosh

    Full Text Available This study investigated the role of CBM35 from Clostridium thermocellum (CtCBM35 in polysaccharide recognition. CtCBM35 was cloned into pET28a (+ vector with an engineered His6 tag and expressed in Escherichia coli BL21 (DE3 cells. A homogenous 15 kDa protein was purified by immobilized metal ion chromatography (IMAC. Ligand binding analysis of CtCBM35 was carried out by affinity electrophoresis using various soluble ligands. CtCBM35 showed a manno-configured ligand specific binding displaying significant association with konjac glucomannan (Ka = 14.3×10(4 M(-1, carob galactomannan (Ka = 12.4×10(4 M(-1 and negligible association (Ka = 12 µM(-1 with insoluble mannan. Binding of CtCBM35 with polysaccharides which was calcium dependent exhibited two fold higher association in presence of 10 mM Ca(2+ ion with konjac glucomannan (Ka = 41×10(4 M(-1 and carob galactomannan (Ka = 30×10(4 M(-1. The polysaccharide binding was further investigated by fluorescence spectrophotometric studies. On binding with carob galactomannan and konjac glucomannan the conformation of CtCBM35 changed significantly with regular 21 nm peak shifts towards lower quantum yield. The degree of association (K a with konjac glucomannan and carob galactomannan, 14.3×10(4 M(-1 and 11.4×10(4 M(-1, respectively, corroborated the findings from affinity electrophoresis. The association of CtCBM35with konjac glucomannan led to higher free energy of binding (ΔG -25 kJ mole(-1 as compared to carob galactomannan (ΔG -22 kJ mole(-1. On binding CtCBM35 with konjac glucomannan and carob galactomannan the hydrodynamic radius (RH as analysed by dynamic light scattering (DLS study, increased to 8 nm and 6 nm, respectively, from 4.25 nm in absence of ligand. The presence of 10 mM Ca(2+ ions imparted stiffer orientation of CtCBM35 particles with increased RH of 4.52 nm. Due to such stiffer orientation CtCBM35 became more thermostable and its melting temperature was

  4. Calcium

    Science.gov (United States)

    ... and blood vessels contract and expand, to secrete hormones and enzymes and to send messages through the nervous system. It is important to get plenty of calcium in the foods you eat. Foods rich in calcium include Dairy products such as milk, cheese, and yogurt Leafy, green vegetables Fish with ...

  5. Calcium

    Science.gov (United States)

    ... from dietary supplements are linked to a greater risk of kidney stones, especially among older adults. But calcium from foods does not appear to cause kidney stones. For most people, other factors (such as not drinking enough fluids) probably have ...

  6. Experimental study of aluminum and calcium malonate complexation at 25, 35, and 80°C

    Science.gov (United States)

    Fein, Jeremy B.; Yane, Lawrence; Jyoti, Ajay; Handa, Tanya

    1995-03-01

    The solubility of gibbsite was measured at 35 and 80°C, and the solubility of portlandite was measured at 25, 35, and 80°C, each as a function of pH and malonate concentration. The gibbsite solubility data can be satisfactorily modelled using only one aqueous Al-malonate species. The data rule out all possible Alp(OH)q(Mal)r3p-q-2r and Alp(OH)q(HMal)r3p-q-r stoichiometries except Al(Mal)2- and Al(OH )2(HMal)2, each of which provides an excellent fit to all of the experimental solubility data. If Al(Mal)2- is the dominant species, the data constrain the value for the log of the dissociation constant of Al(Mal)2- to be -11.3 ± 1.0 and -14.5 ± 0.5 at 35 and 80°C, respectively. If Al(OH)2(HMal)2- is the dominant species, the values of its dissociation constant at 35°C and at 80°C are -27.3 ± 1.0 and -27.6 ± 0.5, respectively. The portlandite solubilities indicate that Ca(Mal)0 is the dominant Ca-malonate complex, with values for the log of the dissociation constant of Ca(Mal)0 of -2.4 ± 0.3, -2.4 ± 0.3, and -2.9 ± 0.3, at 25, 35, and 80°C, respectively. Thermodynamic modelling, using these results, indicates that Al-malonate complexation can potentially enhance the solubility of Al-bearing minerals by up to five orders of magnitude.

  7. [Effect of tanshinone IIA on the change of calcium current induced by beta-amyloid protein 25-35 in neurons of nucleus basalis of Meynert].

    Science.gov (United States)

    Zhu, Shujuan; Qian, Yihua; Shi, Lili; Yang, Weina; Feng, Xinzheng; Li, Cuiqin; Liu, Yong

    2010-08-01

    To explore the effect of tanshinone IIA (TanIIA) on calcium current induced by beta-amyloid protein 25-35 (Abeta25-35) in neurons of nucleus basalis of Meynert (nbM). Cell acute dissociated technique and the whole-cell recording model of patch-clamp technique of single-cell were used. The voltage-dependent calcium current in neurons of nbM was recorded in SD rats first. Then the effect of TanIIA on the voltage-dependent calcium current in the neurons was assayed. The change of calcium current induced by Abeta25-35 as well as the effect of TanIIA on the change of calcium current induced by Abeta25-35 in neurons of nbM were analyzed. Extracellular fluid containing different concentrations of TanIIA was irrigated, respectively. The peak current did not change obviously. There was no difference in current density between the TanIIA group and the control group at 0 mV (P>0.05). Extracellular fluid containing 200 nmol/L Abeta25-35 was irrigated after the normal calcium current recorded under whole patch clamp, and the peak current changed obviously. There was distinct difference in the current density between the Abeta group and the control group at 0 mV (Pcalcium current was recorded under whole patch clamp, respectively, and the peak current did not change. There was no difference in current density between the TanIIA +Abeta group and the control group at 0 mV (P>0.05). In vitro, TanIIA could inhibit the calcium current amplification induced by Abeta25-35 in neurons of nbM. TanIIA may protect neurons against the toxicity of Abeta and decrease the inward flow of Ca(2+).

  8. [Effect of calmodulin and 3':5'-AMP-dependent protein kinases on calcium transport by sarcoplasmic reticulum of normal rabbit myocardium and in toxico-allergic myocarditis].

    Science.gov (United States)

    Karsanov, N V; Khugashvili, Z G

    1983-08-01

    It was demonstrated that under normal conditions calmodulin and exogenous 3':5'-AMP-dependent protein kinase considerably active Ca2+ transport by sarcoplasmic reticulum of rabbit myocardium; a combined action of these compounds produces an additive effect. The protein-inhibitor of 3':5'-AMP-dependent protein kinase and trifluoroperazine eliminate the activating effect of 3':5'-AMP-dependent protein kinase; in addition, trifluoroperazine decreases significantly the basal level of Ca2+ uptake. The 3':5'-AMP-dependent activation of Ca2+ transport becomes apparent after Ca2+-calmodulin-dependent phosphorylation of FSR membrane proteins. In toxico-allergic myocarditis calmodulin and 3':5'-AMP-dependent protein kinase do not activate the low level of Ca2+ uptake. No differences were observed between the action of calmodulin and 3':5'-AMP-dependent protein kinase isolated from normal and pathological rabbit heart. A conclusion is drawn that the decrease of Ca2+ transport is due to the impairment of Ca2+-calmodulin and 3':5'-AMP-dependent phosphorylation in sarcoplasmic reticulum membranes.

  9. Calcium - urine

    Science.gov (United States)

    Urinary Ca+2; Kidney stones - calcium in urine; Renal calculi - calcium in your urine; Parathyroid - calcium in urine ... Urine calcium level can help your provider: Decide on the best treatment for the most common type of kidney ...

  10. Calcium Carbonate

    Science.gov (United States)

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

  11. Calcium supplements

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007477.htm Calcium supplements To use the sharing features on this page, please enable JavaScript. WHO SHOULD TAKE CALCIUM SUPPLEMENTS? Calcium is an important mineral for the ...

  12. Levels of available phosphorus and calcium for broilers from 8 to 35 days of age fed rations containing phytase Níveis de fósforo disponível e de cálcio para frangos de corte de 8 a 35 dias de idade alimentados com rações contendo fitase

    Directory of Open Access Journals (Sweden)

    Adimar Cardoso Júnior

    2010-06-01

    Full Text Available Two experiments using Cobb broiler chicks from 8 to 35 days of age were carried out to evaluate the effect of reducing levels of calcium and available phosphorus in diets supplemented with 500 ftu phytase/kg on the performance of the birds, the content of ashes in the tibia, the metabolizable energy of the diet, and the metabolizability of the dry matter and crude protein. It was used 1,404 broiler chicks in the experiment 1 to evaluate feed intake, weight gain, food conversion and percentage of the ashes in the tibia. In the experiment 2, simultaneously carried out with experiment 1, a total of 390 birds were transferred to a metabolism room to determine the metabolizable energy and metabolizability of the dry matter and crude protein. It was used in the two experiments, a complete random design in a 3 × 4 + 1 factorial scheme with three levels of available phosphorus (0.375; 0.325; and 0.275% and four levels of calcium (0.85; 0.75; 0.65 and 0.55% in the diets, supplemented with phytase. It was also used a control diet without phytase, based on corn and soybean bran, formulated with 0.425% of available phosphorus and 0.85% of calcium. In the experiment 1, the reduction of levels of calcium and phosphorus did not cause a significant difference on the performance and percentage of bone ashes. The levels of calcium and available phosphorus used in the experiment 2 can be reduced down to 0.65 and 0.325%, respectively, because the effects are similar to those obtained with the currently suggested levels.Dois experimentos com pintos de corte da linhagem Cobb no período de 8 a 35 dias de idade foram realizados para avaliar o efeito da redução dos níveis de cálcio e fósforo disponível (Pdisp em rações suplementadas com 500 ftu de fitase/kg sobre o desempenho das aves, o teor de cinzas na tíbia, a energia metabolizável (EMAn da dieta e a metabolizabilidade da matéria seca (MS e da proteína bruta (PB. No experimento 1, foram utilizados 1

  13. 21 CFR 184.1229 - Calcium stearate.

    Science.gov (United States)

    2010-04-01

    ... Specific Substances Affirmed as GRAS § 184.1229 Calcium stearate. (a) Calcium stearate (Ca(C17H35COO)2, CAS Reg. No. 1529-23-0) is the calcium salt of stearic acid derived from edible sources. It is prepared as... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium stearate. 184.1229 Section 184.1229 Food...

  14. Calcium Electroporation

    DEFF Research Database (Denmark)

    Frandsen, Stine Krog; Gibot, Laure; Madi, Moinecha

    2015-01-01

    BACKGROUND: Calcium electroporation describes the use of high voltage electric pulses to introduce supraphysiological calcium concentrations into cells. This promising method is currently in clinical trial as an anti-cancer treatment. One very important issue is the relation between tumor cell kill...... efficacy-and normal cell sensitivity. METHODS: Using a 3D spheroid cell culture model we have tested the effect of calcium electroporation and electrochemotherapy using bleomycin on three different human cancer cell lines: a colorectal adenocarcinoma (HT29), a bladder transitional cell carcinoma (SW780......), and a breast adenocarcinoma (MDA-MB231), as well as on primary normal human dermal fibroblasts (HDF-n). RESULTS: The results showed a clear reduction in spheroid size in all three cancer cell spheroids three days after treatment with respectively calcium electroporation (p

  15. Get Enough Calcium

    Science.gov (United States)

    ... Calcium Print This Topic En español Get Enough Calcium Browse Sections The Basics Overview Foods and Vitamins ... women, don't get enough calcium. How much calcium do I need every day? Women: If you ...

  16. Calcium carbonate overdose

    Science.gov (United States)

    Tums overdose; Calcium overdose ... Calcium carbonate can be dangerous in large amounts. ... Some products that contain calcium carbonate are certain: ... and mineral supplements Other products may also contain calcium ...

  17. 42 CFR 35.35 - Unsalable articles.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Unsalable articles. 35.35 Section 35.35 Public... HOSPITAL AND STATION MANAGEMENT Disposition of Articles Produced by Patients § 35.35 Unsalable articles. Articles having no commercial value shall be stored, destroyed, or otherwise disposed of as the officer in...

  18. Calcium paradox and calcium entry blockers

    NARCIS (Netherlands)

    Ruigrok, T.J.C.; Slade, A.M.; Nayler, W.G.; Meijler, F.L.

    1984-01-01

    Reperfusion of isolated hearts with calcium-containing solution after a short period of calcium-free perfusion results in irreversible cell damage (calcium paradox). This phenomenon is characterized by an excessive influx of calcium into the cells, the rapid onset of myocardial contracture,

  19. Coronary Calcium Scan

    Science.gov (United States)

    ... Back To Health Topics / Coronary Calcium Scan Coronary Calcium Scan Also known as Calcium Scan Test A coronary calcium scan is a CT scan of your heart that detects and measures the amount of calcium in the walls of your coronary arteries. Overview ...

  20. Calcium source (image)

    Science.gov (United States)

    Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...

  1. Calcium and bones (image)

    Science.gov (United States)

    Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human ... body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the ...

  2. Calcium hydroxide poisoning

    Science.gov (United States)

    Hydrate - calcium; Lime milk; Slaked lime ... Calcium hydroxide ... These products contain calcium hydroxide: Cement Limewater Many industrial solvents and cleaners (hundreds to thousands of construction products, flooring strippers, brick cleaners, cement ...

  3. Calcium Pyrophosphate Deposition (CPPD)

    Science.gov (United States)

    ... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

  4. Calcium blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003477.htm Calcium blood test To use the sharing features on this page, please enable JavaScript. The calcium blood test measures the level of calcium in the blood. ...

  5. Embryonic mobilization of calcium in a viviparous reptile: evidence for a novel pattern of placental calcium secretion.

    Science.gov (United States)

    Fregoso, Santiago P; Stewart, James R; Ecay, Tom W

    2010-05-01

    Yolk reserves supply the majority of embryonic nutrition in squamate reptiles, including calcium. Embryos of oviparous squamates exploit the eggshell for supplemental calcium, while embryos of viviparous species may receive additional calcium via the placenta. Developmental uptake of calcium in oviparous snakes increases during the interval of greatest embryonic growth (stage 35 to parturition). However, the pattern of embryonic calcium acquisition is unknown for viviparous snakes. Furthermore, while the uterus of oviparous species transports calcium early in embryonic development during mineralization of the eggshell, the timing of uterine calcium secretion in viviparous snakes is unknown. We studied a viviparous snake, Virginia striatula, to determine the ontogenetic pattern of yolk and embryonic calcium content. The pattern of embryonic calcium uptake of V. striatula is similar to that of oviparous snakes but the sources of calcium differ. In contrast to oviparous species, embryos of V. striatula acquire half of total neonatal calcium via placental provision, of which 71% is mobilized between stage 35 and parturition. Furthermore, we report for the first time in a viviparous squamate an increase in yolk calcium content during early stages of embryonic development, indicating that uterine secretion of calcium occurs in V. striatula coincident with shelling in oviparous squamates. Thus, uterine calcium secretion in this viviparous species may either occur continuously or in two phases, coincident with the timing of shelling in oviparous species and again during the last stages of development. Whereas, the pattern of embryonic calcium acquisition in V. striatula is plesiomorphic for squamates, the pattern of uterine calcium secretion includes both retention of a plesiomorphic trait and the evolution of a novel trait. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Substitutions in Calcium Aluminates and Calcium Aluminoferrites.

    Science.gov (United States)

    ALUMINUM COMPOUNDS, *CEMENTS, * CALCIUM COMPOUNDS, * FERRITES , *SCIENTIFIC RESEARCH, INFRARED SPECTROSCOPY, X RAY DIFFRACTION, CHEMICAL COMPOSITION, SUBSTITUTES, CHEMICAL ANALYSIS, ALKALI METAL COMPOUNDS.

  7. Boron, calcium and magnesium in Kavaratti lagoon water, Lakshadweep Archipelago

    Digital Repository Service at National Institute of Oceanography (India)

    Nasnolkar, C.M.; Salkar, V.R.; Shirodkar, P.V.; Abidi, S.A.H.

    1228.8 to 1319.8 mg kg sup(-1) (av. 1280.19 mg kg sup(-1)) and the salinity varied from 35.01 to 35.10 x 10 sup(-3) (av. 35.04 x 10 sup(-3)). The ratios of boron, calcium and magnesium to chlorinity in the lagoon water showed wide variation and were...

  8. Calcium channel blocker overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002580.htm Calcium-channel blocker overdose To use the sharing features on this page, please enable JavaScript. Calcium-channel blockers are a type of medicine used to ...

  9. Fenoprofen calcium overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002649.htm Fenoprofen calcium overdose To use the sharing features on this page, please enable JavaScript. Fenoprofen calcium is a type of medicine called a nonsteroidal ...

  10. Calcium and Mitosis

    Science.gov (United States)

    Hepler, P.

    1983-01-01

    Although the mechanism of calcium regulation is not understood, there is evidence that calcium plays a role in mitosis. Experiments conducted show that: (1) the spindle apparatus contains a highly developed membrane system that has many characteristics of sarcoplasmic reticulum of muscle; (2) this membrane system contains calcium; and (3) there are ionic fluxes occurring during mitosis which can be seen by a variety of fluorescence probes. Whether the process of mitosis can be modulated by experimentally modulating calcium is discussed.

  11. Calcium concentration in the CAPD dialysate

    DEFF Research Database (Denmark)

    Bro, S; Brandi, L; Daugaard, H

    1998-01-01

    with a reduced dialysate Ca concentration (1.00, 1.25, or 1.35 mmol/L) improved the tolerance to calcium carbonate and/or vitamin D metabolites and reduced the need for Al-containing phosphate binders. When using dialysate Ca 1.25 or 1.35 mmol/L, the initial decrease of plasma Ca and increase of PTH could easily......), doses of calcium carbonate, doses of vitamin D analogs, and requirements of aluminum-containing phosphate binders. STUDY SELECTION: Eleven studies of nonselected CAPD patients, and 13 studies of CAPD patients with hypercalcemia were reviewed. RESULTS: In nonselected CAPD patients, treatment...... for the progression of secondary hyperparathyroidism. When hypercalcemia was present in combination with suppressed PTH levels, a controlled increase of PTH could be obtained with a temporary discontinuation of vitamin D and/or a reduction of calcium carbonate treatment in combination with a dialysate Ca...

  12. Calcium en cardioplegie

    NARCIS (Netherlands)

    Ruigrok, T.J.C.; Meijler, F.L.

    1985-01-01

    Coronary perfusion with a calcium-free solution, followed by reperfusion with a calcium containing solution, may result in acute myocardial cell death and in irreversible loss of the e1ectrical and mechanical activity of the heart. This phenomenon is known as the calcium paradox. A number of

  13. Pregnancy After Age 35

    Science.gov (United States)

    ... Global Map Premature Birth Report Cards Careers Archives Pregnancy Before or between pregnancies Nutrition, weight & fitness Prenatal ... Complications & Loss > Pregnancy complications > Pregnancy after age 35 Pregnancy after age 35 E-mail to a friend ...

  14. Consumption of calcium-fortified cereal bars to improve dietary calcium intake of healthy women: randomized controlled feasibility study.

    Directory of Open Access Journals (Sweden)

    Jennifer T Lee

    Full Text Available Calcium is an important structural component of the skeletal system. Although an adequate intake of calcium helps to maintain bone health and reduce the risk of osteoporosis, many women do not meet recommended daily intakes of calcium. Previous interventions studies designed to increase dietary intake of women have utilized primarily dairy sources of calcium or supplements. However, lactose intolerance, milk protein allergies, or food preferences may lead many women to exclude important dairy sources of dietary calcium. Therefore, we undertook a 9 week randomized crossover design trial to examine the potential benefit of including a non-dairy source of calcium in the diet of women. Following a 3 week run-in baseline period, 35 healthy women > 18 years were randomized by crossover design into either Group I or Group II. Group I added 2 calcium-fortified cereal bars daily (total of 400 mg calcium/day (intervention to their usual diet and Group II continued their usual diet (control. At the end of 3 weeks, diets were switched for another 3 weeks. Intakes of calcium and energy were estimated from 3-day diet and supplemental diaries. Wilcoxon signed-rank tests were used for within group comparisons and Mann Whitney U tests were used for between group comparisons of calcium and energy intake. Dietary calcium was significantly higher during intervention (1071 mg/d when participants consumed 2 calcium-fortified cereal bars daily than during the baseline (720 mg/d, P <0.0001 or control diets (775 mg/d, P = 0.0001 periods. Furthermore, the addition of 2 calcium-fortified cereal bars daily for the 3 week intervention did not significantly increase total energy intake or result in weight gain. In conclusion, consumption of calcium-fortified cereal bars significantly increased calcium intake of women. Further research examining the potential ability of fortified cereal bars to help maintain and improve bone health of women is warranted.ClinicalTrials.gov NCT

  15. [Calcium/protein relation of women on the climacteric].

    Science.gov (United States)

    Montilla, Regina das Neves Girão; Aldrighi, José Mendes; Marucci, Maria de Fátima Nunes

    2004-01-01

    To evaluate the calcium/protein relation of the diet of climacteric women. In a transversal study the diet was evaluated of 154 women 35-65 years old and matriculated in the Health Clinic of the Climateric Woman of Health Center of Public Health College of the São Paulo University. The food intake of calcium and protein was investigated by "24 hours recall" method. The evaluation of calcium/protein relation was made according to Massey and Heaney (1998), that is 20/1 (mg/g). The mean of intake of calcium was 624.9 mg, the mean of intake of protein was 86.7 g and the calcium/protein relation was 7/1 (624.9 mg/86.7 g). The studied population presents inadequated consumation of the calcium and protein nutrients. It could result in serious risk for health.

  16. Quantification of Dialytic Removal and Extracellular Calcium Mass Balance during a Weekly Cycle of Hemodialysis.

    Directory of Open Access Journals (Sweden)

    Jacek Waniewski

    Full Text Available The removal of calcium during hemodialysis with low calcium concentration in dialysis fluid is generally slow, and the net absorption of calcium from dialysis fluid is often reported. The details of the calcium transport process during dialysis and calcium mass balance in the extracellular fluid, however, have not been fully studied.Weekly cycle of three dialysis sessions with interdialytic breaks of 2-2-3 days was monitored in 25 stable patients on maintenance hemodialysis with calcium concentration in dialysis fluid of 1.35 mmol/L. Total and ionic calcium were frequently measured in blood and dialysate. The volume of fluid compartments was measured by bioimpedance.Weekly dialytic removal of 12.79 ± 8.71 mmol calcium was found in 17 patients, whereas 9.48 ± 8.07 mmol calcium was absorbed per week from dialysis fluid in 8 patients. Ionic calcium was generally absorbed from dialysis fluid, whereas complexed calcium (the difference of total and ionic calcium in dialysis fluid was removed from the body. The concentration of total calcium in plasma increased slightly during dialysis. The mass of total and ionic calcium in extracellular fluid decreased during dialysis in patients with the dialytic removal of calcium from the body and did not change in patients with the absorption of calcium from dialysis fluid.We conclude that about one third of patients on dialysis with calcium 1.35 mmol/L in dialysis fluid may absorb calcium from dialysis fluid and therefore individual prescriptions of calcium concentration in dialysis fluid should be considered for such patients.

  17. Calcium channel blocker poisoning

    Directory of Open Access Journals (Sweden)

    Miran Brvar

    2005-04-01

    Full Text Available Background: Calcium channel blockers act at L-type calcium channels in cardiac and vascular smooth muscles by preventing calcium influx into cells with resultant decrease in vascular tone and cardiac inotropy, chronotropy and dromotropy. Poisoning with calcium channel blockers results in reduced cardiac output, bradycardia, atrioventricular block, hypotension and shock. The findings of hypotension and bradycardia should suggest poisoning with calcium channel blockers.Conclusions: Treatment includes immediate gastric lavage and whole-bowel irrigation in case of ingestion of sustainedrelease products. All patients should receive an activated charcoal orally. Specific treatment includes calcium, glucagone and insulin, which proved especially useful in shocked patients. Supportive care including the use of catecholamines is not always effective. In the setting of failure of pharmacological therapy transvenous pacing, balloon pump and cardiopulmonary by-pass may be necessary.

  18. Acidosis and Urinary Calcium Excretion

    DEFF Research Database (Denmark)

    Alexander, R Todd; Cordat, Emmanuelle; Chambrey, Régine

    2016-01-01

    Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and inhibi...

  19. Calcium and bones

    Science.gov (United States)

    ... eat in their diet. Vitamin D is the hormone that helps the gut absorb more calcium. Many older adults have common risks that make bone health worse. Calcium intake in the diet (milk, cheese, yogurt) is low. Vitamin D levels are ...

  20. Calcium D-saccharate

    DEFF Research Database (Denmark)

    Garcia, André Castilho; Hedegaard, Martina Vavrusova; Skibsted, Leif Horsfelt

    2016-01-01

    Molar conductivity of saturated aqueous solutions of calcium d-saccharate, used as a stabilizer of beverages fortified with calcium d-gluconate, increases strongly upon dilution, indicating complex formation between calcium and d-saccharate ions, for which, at 25 °C, Kassoc = 1032 ± 80, ΔHassoc......° = -34 ± 6 kJ mol-1, and ΔSassoc° = -55 ± 9 J mol-1 K-1, were determined electrochemically. Calcium d-saccharate is sparingly soluble, with a solubility product, Ksp, of (6.17 ± 0.32) × 10-7 at 25 °C, only moderately increasing with the temperature: ΔHsol° = 48 ± 2 kJ mol-1, and ΔSassoc° = 42 ± 7 J mol-1...... K-1. Equilibria in supersaturated solutions of calcium d-saccharate seem only to adjust slowly, as seen from calcium activity measurements in calcium d-saccharate solutions made supersaturated by cooling. Solutions formed by isothermal dissolution of calcium d-gluconate in aqueous potassium d...

  1. Extracellular Calcium and Magnesium

    African Journals Online (AJOL)

    ABSTRACT. The cause of preeclampsia remains unknown and calcium and magnesium supplement are being suggested as means of prevention. The objective of this study was to assess magnesium and calcium in the plasma and cerebrospinal fluid of Nigerian women with preedamp sia and eclampsia. Setting was ...

  2. HYPERTHERMIA, INTRACELLULAR FREE CALCIUM AND CALCIUM IONOPHORES

    NARCIS (Netherlands)

    STEGE, GJJ; WIERENGA, PK; KAMPINGA, HH; KONINGS, AWT

    1993-01-01

    It is shown that heat-induced increase of intracellular calcium does not correlate with hyperthermic cell killing. Six different cell lines were investigated; in four (EAT, HeLa S3, L5178Y-R and L5178Y-S) heat treatments killing 90% of the cells did not affect the levels of intracellular free

  3. Programming NET 35

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Bestselling author Jesse Liberty and industry expert Alex Horovitz uncover the common threads that unite the .NET 3.5 technologies, so you can benefit from the best practices and architectural patterns baked into the new Microsoft frameworks. The book offers a Grand Tour" of .NET 3.5 that describes how the principal technologies can be used together, with Ajax, to build modern n-tier and service-oriented applications. "

  4. Calcium sensing in exocytosis

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Wu, Bingbing; Han, Weiping

    2012-01-01

    Neurotransmitters, neuropeptides and hormones are released through regulated exocytosis of synaptic vesicles and large dense core vesicles. This complex and highly regulated process is orchestrated by SNAREs and their associated proteins. The triggering signal for regulated exocytosis is usually...... an increase in intracellular calcium levels. Besides the triggering role, calcium signaling modulates the precise amount and kinetics of vesicle release. Thus, it is a central question to understand the molecular machineries responsible for calcium sensing in exocytosis. Here we provide an overview of our...

  5. Nuclear symmetry energy in calcium-calcium collisions (INDRA-VAMOS

    Directory of Open Access Journals (Sweden)

    Chartier M.

    2012-07-01

    Full Text Available The density dependence of the symmetry energy is of great interest to many fields of nuclear physics and nuclear astro-physics. The E503 INDRA-VAMOS experiment performed at GANIL in 2007 is intended to provide further sub-saturation constraints using calcium-calcium collisions around the Fermi energy (35AMeV. In these proceedings this experiment will be discussed in the context of the physics it is aiming to study and will give a brief summary of the current progress of the data analysis.

  6. Bone repair in calcium-deficient rats: comparison of xylitol+calcium carbonate with calcium carbonate, calcium lactate and calcium citrate on the repletion of calcium.

    Science.gov (United States)

    Hämäläinen, M M

    1994-06-01

    The potential value of xylitol in calcium therapy was evaluated by comparing the effect of dietary xylitol (50 g/kg diet) + calcium carbonate with the effects of calcium carbonate, calcium lactate and calcium citrate on bone repair of young male rats after the rats consumed for 3 wk a calcium-deficient diet (0.2 g Ca/kg diet). After this calcium-depletion period, the rats were fed for 2 wk one of four diets, each containing 5 g Ca/kg diet as one of the four dietary calcium sources. The diet of the control animals was supplemented with CaCO3 (5 g Ca/kg diet) throughout the study. The Ca-deficient rats showed low bone mass, low serum calcium and high serum 1,25-dihydroxycholecalciferol, parathyroid hormone (1-34 fraction) and osteocalcin concentrations. They also excreted magnesium, phosphate and hydroxyproline in the urine in high concentrations, and had high bone alkaline phosphatase and tartrate-resistant acid phosphatase activities. Most of these changes were reversed by the administered of the calcium salts. The highest recoveries of femoral dry weight, calcium, magnesium and phosphate were observed in the groups receiving xylitol+CaCO3 and calcium lactate. Calcium lactate and calcium citrate caused low serum phosphate concentration compared with rats receiving CaCO3 and with the age-matched Ca-replete controls. Xylitol-treated rats excreted more calcium and magnesium in urine than did the other rats, probably due to increased absorption of these minerals from the gut. These results suggest that dietary xylitol improves the bioavailability of calcium salts.

  7. High calcium and dobutamine positive inotropy in the perfused mouse heart: myofilament calcium responsiveness, energetic economy, and effects of protein kinase C inhibition

    Directory of Open Access Journals (Sweden)

    Du Congwu

    2001-08-01

    Full Text Available Abstract Background In perfused hearts, high calcium-induced inotropy results in less developed pressure relative to myocardial oxygen consumption compared to the β-adrenergic agonist dobutamine. Calcium handling is an important determinant of myocardial oxygen consumption. Therefore, we hypothesized that this phenomenon was due to reduced myofilament responsiveness to calcium, related to protein kinase C activation. Results Developed pressure was significantly higher with dobutamine compared to high perfusate calcium of 3.5 mM (73 ± 10 vs 63 ± 10 mmHg, p Conclusions By measuring intracellular calcium, developed pressures and myocardial oxygen consumption in perfused mouse hearts, these results demonstrate that high perfusate calcium positive inotropy compared to dobutamine results in reduced myofilament responsiveness to intracellular calcium, which is associated with energetic inefficiency and evidence of protein kinase C activation.

  8. Calcium – how and why?

    Indian Academy of Sciences (India)

    Unknown

    Calcium is among the most commonly used ions, in a multitude of biological functions, so much so that it is impossible to imagine life without calcium. In this article I have attempted to address the question as to how calcium has achieved this status with a brief mention of the history of calcium research in biology. It appears ...

  9. Calcium and Your Child

    Science.gov (United States)

    ... Milk Allergy Figuring Out Food Labels What's a Vegetarian? Osteoporosis Minerals Your Bones Mineral Chart Vitamin D ... Need to Drink Milk? Lactose Intolerance Becoming a Vegetarian Soy Foods and Health Calcium Bones, Muscles, and ...

  10. Stoichiometry of Calcium Medicines

    Science.gov (United States)

    Pinto, Gabriel

    2005-01-01

    The topic of calcium supplement and its effects on human lives is presented in the way of questions to the students. It enables the students to realize the relevance of chemistry outside the classroom surrounding.

  11. Magnesium, calcium and cancer

    National Research Council Canada - National Science Library

    Anghileri, Leopoldo J

    2009-01-01

    Magnesium ion (Mg(2+)) and calcium ion (Ca(2+)) control a diverse and important range of cellular processes, such as gene transcription, cell proliferation, neoplastic transformation, immune response and therapeutic treatment...

  12. [Calcium suppletion for patients who use gastric acid inhibitors: calcium citrate or calcium carbonate?].

    NARCIS (Netherlands)

    Jonge, H.J. de; Gans, R.O.; Huls, G.A.

    2012-01-01

    Various calcium supplements are available for patients who have an indication for calcium suppletion. American guidelines and UpToDate recommend prescribing calcium citrate to patients who use antacids The rationale for this advice is that water-insoluble calcium carbonate needs acid for adequate

  13. Calcium in plant cells

    Directory of Open Access Journals (Sweden)

    V. V. Schwartau

    2014-04-01

    Full Text Available The paper gives the review on the role of calcium in many physiological processes of plant organisms, including growth and development, protection from pathogenic influences, response to changing environmental factors, and many other aspects of plant physiology. Initial intake of calcium ions is carried out by Ca2+-channels of plasma membrane and they are further transported by the xylem owing to auxins’ attractive ability. The level of intake and selectivity of calcium transport to ove-ground parts of the plant is controlled by a symplast. Ca2+enters to the cytoplasm of endoderm cells through calcium channels on the cortical side of Kaspary bands, and is redistributed inside the stele by the symplast, with the use of Ca2+-АТPases and Ca2+/Н+-antiports. Owing to regulated expression and activity of these calcium transporters, calclum can be selectively delivered to the xylem. Important role in supporting calcium homeostasis is given to the vacuole which is the largest depo of calcium. Regulated quantity of calcium movement through the tonoplast is provided by a number of potential-, ligand-gated active transporters and channels, like Ca2+-ATPase and Ca2+/H+ exchanger. They are actively involved in the inactivation of the calcium signal by pumping Ca2+ to the depo of cells. Calcium ATPases are high affinity pumps that efficiently transfer calcium ions against the concentration gradient in their presence in the solution in nanomolar concentrations. Calcium exchangers are low affinity, high capacity Ca2+ transporters that are effectively transporting calcium after raising its concentration in the cell cytosol through the use of protons gradients. Maintaining constant concentration and participation in the response to stimuli of different types also involves EPR, plastids, mitochondria, and cell wall. Calcium binding proteins contain several conserved sequences that provide sensitivity to changes in the concentration of Ca2+ and when you

  14. [Microbial geochemical calcium cycle].

    Science.gov (United States)

    Zavarzin, G A

    2002-01-01

    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.

  15. Presentation VI-35

    OpenAIRE

    Vega, Omar Antonio

    2016-01-01

    Edition 35, corresponding to half of 2016, includes nine of the 15 items proposed for consideration during the call closed on February 20, 2016, from Colombian universities (of Manizales, of Caldas, Nacional de Colombia, ECCI, Pilot of Colombia, Technologic of Pereira, Libre of Barranquilla and Metropolitan Technological Institute), Mexico (of La Salle Bajio, Autonomous of Nayarit, State of Sonora, Quintana Roo and Technological Institute of Toluca); Spanish (International of La Rioja and Sal...

  16. 35 REVIEW ARTICLE

    African Journals Online (AJOL)

    boaz

    MICROBIOL. 17 (1): 35-45 http://dx.doi.org/10.4314/ajcem.v17i1.5. SPECTRUM OF ASPERGILLOSIS: PATHOGENESIS, RISK FACTORS AND MANAGEMENT. Iyalla, C. ... Le symptôme clinique d'aspergillose dépend du type et les systèmesaffectés ; les symptômes respiratoires sont plus ..... Mannose-binding lectin gene.

  17. Calcium orthophosphates in dentistry.

    Science.gov (United States)

    Dorozhkin, Sergey V

    2013-06-01

    Dental caries, also known as tooth decay or a cavity, remains a major public health problem in the most communities even though the prevalence of disease has decreased since the introduction of fluorides for dental care. Therefore, biomaterials to fill dental defects appear to be necessary to fulfill customers' needs regarding the properties and the processing of the products. Bioceramics and glass-ceramics are widely used for these purposes, as dental inlays, onlays, veneers, crowns or bridges. Calcium orthophosphates belong to bioceramics but they have some specific advantages over other types of bioceramics due to a chemical similarity to the inorganic part of both human and mammalian bones and teeth. Therefore, calcium orthophosphates (both alone and as components of various formulations) are used in dentistry as both dental fillers and implantable scaffolds. This review provides brief information on calcium orthophosphates and describes in details current state-of-the-art on their applications in dentistry and dentistry-related fields. Among the recognized dental specialties, calcium orthophosphates are most frequently used in periodontics; however, the majority of the publications on calcium orthophosphates in dentistry are devoted to unspecified "dental" fields.

  18. Dietary calcium intake in a cohort of elderly patients already in drug therapy for osteoporosis. Is it possible and how to modify the eating habits before calcium supplementation?

    Directory of Open Access Journals (Sweden)

    Ciro Manzo

    2015-08-01

    Full Text Available Inadequate intake of calcium via the diet is very common in patients taking drugs for osteoporosis. We have evaluated 302 consecutive elderly patients (68.6 median age attending our Rheumatological and Orthopedic Outpatient Clinics using a questionnaire for evaluation of dietary calcium intake. Two hundred and forty of these had a questionnaire score 7 in 205/240 after an average period of 3-6 months. In the 35 patients in which this was not possible, the exact knowledge of calcium dietary intake (poor or absent has allowed a tailored calcium supplementation.

  19. Calcium Signalling: Fishing Out Molecules of Mitochondrial Calcium Transport

    OpenAIRE

    Hajnóczky, György; Csordás, György

    2010-01-01

    Cellular energy metabolism, survival and death are controlled by mitochondrial calcium signals originating in the cytoplasm. Now, RNAi studies link three proteins — MICU1, NCLX and LETM1 — to the previously unknown molecular mechanism of mitochondrial calcium transport.

  20. Gravimetric Determination of Calcium as Calcium Carbonate Hydrate.

    Science.gov (United States)

    Henrickson, Charles H.; Robinson, Paul R.

    1979-01-01

    The gravimetric determination of calcium as calcium carbonate is described. This experiment is suitable for undergraduate quantitative analysis laboratories. It is less expensive than determination of chloride as silver chloride. (BB)

  1. Annex 35: Hybvent

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The Annex 35 research project is aiming at a better knowledge of hybrid systems and focusing on development of control strategies and performance prediction methods for hybrid ventilation in new and retrofitted office buildings. Its main objectives are: • to develop control strategies for hybrid...... ventilation systems in new and retrofitted office and educational buildings • to develop methods to predict ventilation performance in hybrid ventilated buildings • . to select suitable measurement techniques for diagnostic purposes to be used in . buildings with hybrid ventilation systems • to promote energy...... and cost effective hybrid ventilation systems in office and educational buildings...

  2. MECHANISM OF THE PROTECTIVE EFFECT OF SUPPLEMENTAL DIETARY CALCIUM ON CYTOLYTIC ACTIVITY OF FECAL WATER

    NARCIS (Netherlands)

    LAPRE, JA; DEVRIES, HT; TERMONT, DSML; KLEIBEUKER, JH; DEVRIES, EGE; VANDERMEER, R

    1993-01-01

    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

  3. Effects of calcium and humic acid treatment on the growth and ...

    African Journals Online (AJOL)

    Humic acid (HA) may facilitate plant growth by improving the nutrient uptake as well as through hormonal effects. Studies were conducted to investigate the effect of a mixture of calcium and HA on Oriental lily, which is sensitive to calcium deficiency. Two levels of Ca (3.5 and 7.0 meq/L) were combined with 500 mg/L HA ...

  4. Children's Bone Health and Calcium

    Science.gov (United States)

    ... Email Share Dialog × Print Children's Bone Health and Calcium: Condition Information What is bone health and how ... straight, walk, run, and lead an active life. Calcium is one of the key dietary building blocks ...

  5. Stable prenucleation calcium carbonate clusters

    OpenAIRE

    Gebauer, Denis; Völkel, Antje; Cölfen, Helmut

    2008-01-01

    Calcium carbonate forms scales, geological deposits, biominerals, and ocean sediments. Huge amounts of carbon dioxide are retained as carbonate ions, and calcium ions represent a major contribution to water hardness. Despite its relevance, little is known about the precipitation mechanism of calcium carbonate, and specified complex crystal structures challenge the classical view on nucleation considering the formation of metastable ion clusters. We demonstrate that dissolved calcium carbonate...

  6. Assay for calcium channels

    Energy Technology Data Exchange (ETDEWEB)

    Glossmann, H.; Ferry, D.R.

    1985-01-01

    This chapter focuses on biochemical assays for Ca/sup 2 +/-selective channels in electrically excitable membranes which are blocked in electrophysiological and pharmacological experiments by verapamil, 1,4-dihydropyridines, diltiazen (and various other drugs), as well as inorganic di- or trivalent cations. The strategy employed is to use radiolabeled 1,4-dihydropyridine derivatives which block calcium channels with ED/sub 50/ values in the nanomolar range. Although tritiated d-cis-diltiazem and verapamil can be used to label calcium channels, the 1,4-dihydropyridines offer numerous advantages. The various sections cover tissue specificity of channel labeling, the complex interactions of divalent cations with the (/sup 3/H)nimodipine-labeled calcium channels, and the allosteric regulation of (/sup 3/H)nimodipine binding by the optically pure enantiomers of phenylalkylamine and benzothiazepine calcium channel blockers. A comparison of the properties of different tritiated 1,4-dihydropyridine radioligands and the iodinated channel probe (/sup 125/I)iodipine is given.

  7. Solar Imagery - Chromosphere - Calcium

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of full-disk images of the sun in Calcium (Ca) II K wavelength (393.4 nm). Ca II K imagery reveal magnetic structures of the sun from about 500...

  8. Diagnosis of alterations of serum calcium metabolism.

    Science.gov (United States)

    Lumachi, Franco; Cappelletti, Piero; Tozzoli, Renato; Basso, Stafano M M; Luisetto, Giovanni; Camozzi, Valentina

    2012-07-01

    Calcium is essential to homeostasis and functioning of multiple organ systems. Its circulating concentration is maintained within a very tight physiologic range: 2.25 and 2.50 mmol/L. Under physiological conditions, the ionized calcium concentration is regulated by the parathyroid hormone (PTH), and 1,25(OH)(2) vitamin D through interactions on target organs such as kidney, bone and intestine. In mild, moderate, and severe hypercalcemia, laboratory findings are essential in assessing and monitoring disease course and therapy. The main tools are specific standard biochemical tests able to assess calcium balance and renal function, and some specific biochemical tests, such as PTH, 25(OH) vitamin D, and genetic sequencing, used to clarify the cause of hypercalcemia and, subsequently, to determine appropriate therapy. Once hypercalcemia is confirmed by ionized calcium measurement, the intact PTH assay plays a crucial role to differentiate PTH-mediated from non-PTH-mediated hypercalcemia. Mild hypercalcemia is also present in up to 10-20% of patients treated with lithium for bipolar disorders, in 7-8% of those treated with thiazide diuretics, and in patients with prolonged immobilization, while very high (>3.5 mmol/L) serum calcium levels, together with low PTH, and a rapid increase of hypercalcemia, usually suggest a malignancy-associated hypercalcemic syndrome. The measurement of PTH-related protein, a tumor product that mimics certain action of PTH, is useful only in selected cases. The role of biochemical markers of bone turnover for predicting metastatic bone disease, and monitoring bone metabolic changes, and their usefulness as a predictive mean of the likelihood of bone loss or fractures risk is still unclear.

  9. The Plasma Membrane Calcium Pump

    Science.gov (United States)

    Rasmussen, H.

    1983-01-01

    Three aspect of cellular calcium metabolism in animal cells was discussed including the importance of the plasma membrane in calcium homeostasis, experiments dealing with the actual mechanism of the calcium pump, and the function of the pump in relationship to the mitochondria and to the function of calmodulin in the intact cell.

  10. Calcium addition in straw gasification

    DEFF Research Database (Denmark)

    Risnes, H.; Fjellerup, Jan Søren; Henriksen, Ulrik Birk

    2003-01-01

    The present work focuses on the influence of calcium addition in gasification. The inorganic¿organic element interaction as well as the detailed inorganic¿inorganic elements interaction has been studied. The effect of calcium addition as calcium sugar/molasses solutions to straw significantly...

  11. Impregnating Coal With Calcium Carbonate

    Science.gov (United States)

    Sharma, Pramod K.; Voecks, Gerald E.; Gavalas, George R.

    1991-01-01

    Relatively inexpensive process proposed for impregnating coal with calcium carbonate to increase rates of gasification and combustion of coal and to reduce emission of sulfur by trapping sulfur in calcium sulfide. Process involves aqueous-phase reactions between carbon dioxide (contained within pore network of coal) and calcium acetate. Coal impregnated with CO2 by exposing it to CO2 at high pressure.

  12. Interactions of genotype, housing and dietary calcium in layer ...

    African Journals Online (AJOL)

    The study was designed to evaluate the interactions in performance, eggshell quality and tibia traits of two laying hen genotypes, namely a commercial hybrid, Lohmann (LSL), and a traditional breed, the Czech Hen (CH), housed in conventional cages and on litter, and fed two levels of dietary calcium (Ca) (3.5% vs. 3.0%).

  13. Shape control synthesis of low-dimensional calcium sulfate

    Indian Academy of Sciences (India)

    Calcium sulfate nanorods, nanowires, nanobelts and sheets had been synthesized via a facile solution reaction of CaCl2 and H2SO4 in mixed solvents of ethanol/, -dimethylformamide and deionized water at 35°C. The results indicated that well-crystallized CaSO4 nanomaterials with different morphology were obtained ...

  14. Calcium signaling in taste cells.

    Science.gov (United States)

    Medler, Kathryn F

    2015-09-01

    The sense of taste is a common ability shared by all organisms and is used to detect nutrients as well as potentially harmful compounds. Thus taste is critical to survival. Despite its importance, surprisingly little is known about the mechanisms generating and regulating responses to taste stimuli. All taste responses depend on calcium signals to generate appropriate responses which are relayed to the brain. Some taste cells have conventional synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release to formulate an output signal through a hemichannel. Beyond establishing these characteristics, few studies have focused on understanding how these calcium signals are formed. We identified multiple calcium clearance mechanisms that regulate calcium levels in taste cells as well as a calcium influx that contributes to maintaining appropriate calcium homeostasis in these cells. Multiple factors regulate the evoked taste signals with varying roles in different cell populations. Clearly, calcium signaling is a dynamic process in taste cells and is more complex than has previously been appreciated. This article is part of a Special Issue entitled: 13th European Symposium on Calcium. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Urinary calcium excretion in treated and untreated essential hypertension.

    Science.gov (United States)

    Quereda, C; Orte, L; Sabater, J; Navarro-Antolin, J; Villafruela, J J; Ortuño, J

    1996-07-01

    A high prevalence of hypercalciuria has been reported in patients with essential hypertension. Nevertheless, the clinical and therapeutic implications of this finding have scarcely been studied. This study was designed to determine the prevalence of hypercalciuria in an unselected population with essential hypertension and to analyze the relationship between the urinary calcium and the clinical and therapeutic status of these patients. This article presents a prospective study of 112 patients with essential hypertension and 49 healthy normotensive control subjects. Urinary excretion rates of calcium, sodium, chloride, potassium, urinary calcium/creatinine index, the fractional excretion of sodium, potassium and uric acid, the creatinine clearance and serum values of creatinine, urea, uric acid, electrolytes, total proteins, parathormone (intact molecule), plasma renin activity, aldosterone, glucose, and insulin (fasting and after an oral glucose load) were performed in every patient and control subject. Untreated hypertensive patients had a higher prevalence of hypercalciuria (35% had a urinary calcium/creatinine ratio > 0.20 versus 20% of treated hypertensives and 2% of control subjects; P < 0.001). Patients on thiazide or beta-blocker monotherapy had lower urinary excretion rates of calcium and urate than patients on calcium-antagonist monotherapy or untreated patients. Urinary calcium, sodium, and urate correlated positively both in treated and untreated essential hypertension patients. Patients with the higher urinary calcium levels also had higher excretion rates of sodium and urate, higher creatinine clearance rates, and lower serum creatinine and serum uric acid levels. It was concluded that hypercalciuria is a frequent finding of untreated essential hypertension. The association of high urinary calcium levels with high urinary urate excretion rates in the same patient may predispose to development of lithiasis in patients with essential hypertension

  16. DISTILLATION OF CALCIUM

    Science.gov (United States)

    Barton, J.

    1954-07-27

    This invention relates to an improvement in the process for the purification of caicium or magnesium containing an alkali metal as impurity, which comprises distiiling a batch of the mixture in two stages, the first stage distillation being carried out in the presence of an inert gas at an absolute pressure substantially greater than the vapor pressure of calcium or maguesium at the temperature of distillation, but less than the vaper pressure at that temperature of the alkali metal impurity so that only the alkali metal is vaporized and condensed on a condensing surface. A second stage distilso that substantially only the calcium or magnesium distills under its own vapor pressure only and condenses in solid form on a lower condensing surface.

  17. Calcium metabolism and cardiovascular function after spaceflight

    Science.gov (United States)

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

    2002-01-01

    To determine the influence of dietary calcium on spaceflight-induced alterations in calcium metabolism and blood pressure (BP), 9-wk-old spontaneously hypertensive rats, fed either high- (2%) or low-calcium (0.02%) diets, were flown on an 18-day shuttle flight. On landing, flight animals had increased ionized calcium (P platelet free calcium (intracellular calcium concentration) were also reduced (P metabolism (P metabolism are relatively impervious to dietary calcium in the short term, 2) increased ionized calcium did not normalize low-calcium-induced elevations of BP, and 3) parathyroid hormone was paradoxically increased in the high-calcium-fed flight animals after landing.

  18. Models of calcium signalling

    CERN Document Server

    Dupont, Geneviève; Kirk, Vivien; Sneyd, James

    2016-01-01

    This book discusses the ways in which mathematical, computational, and modelling methods can be used to help understand the dynamics of intracellular calcium. The concentration of free intracellular calcium is vital for controlling a wide range of cellular processes, and is thus of great physiological importance. However, because of the complex ways in which the calcium concentration varies, it is also of great mathematical interest.This book presents the general modelling theory as well as a large number of specific case examples, to show how mathematical modelling can interact with experimental approaches, in an interdisciplinary and multifaceted approach to the study of an important physiological control mechanism. Geneviève Dupont is FNRS Research Director at the Unit of Theoretical Chronobiology of the Université Libre de Bruxelles;Martin Falcke is head of the Mathematical Cell Physiology group at the Max Delbrück Center for Molecular Medicine, Berlin;Vivien Kirk is an Associate Professor in the Depar...

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

    Science.gov (United States)

    Wilson, Rosamund J; Copley, J Brian

    2017-01-01

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

  20. Limestone reaction in calcium aluminate cement–calcium sulfate systems

    OpenAIRE

    Bizzozero, Julien; Scrivener, Karen

    2015-01-01

    This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase evolution and the total porosity were followed and compared to thermodynamic simulation to understand the reactions involved and the effect of limestone on these binders. The reaction of limestone leads to the formation of hemicarboaluminate ...

  1. Mixed calcium-magnesium pre-nucleation clusters enrich calcium

    OpenAIRE

    Verch, Andreas; Antonietti, Markus; Cölfen, Helmut

    2012-01-01

    It is demonstrated that magnesium and carbonate ions can form pre-nucleation clusters in analogy to calcium carbonate. If a mixed calcium and magnesium solution is brought in contact with carbonate ions, mixed pre-nucleation clusters form. The equilibrium constants for their formation are reported revealing that over the entire range of possible cation mixing ratios, calcium gets enriched over magnesium in the pre-nucleation clusters. This can explain high magnesium contents in amorphous calc...

  2. Young Adults' Perceptions of Calcium Intake and Health: A Qualitative Study.

    Science.gov (United States)

    Marcinow, Michelle L; Randall Simpson, Janis A; Whiting, Susan J; Jung, Mary E; Buchholz, Andrea C

    2017-12-01

    Many young Canadian adults are not meeting dietary calcium recommendations. This is concerning as adequate calcium is important throughout young adulthood to maximize peak bone mass for osteoporosis prevention. There are limited studies that have explored young adults' perceptions toward calcium and health. Our objectives were to determine young adults' (18-34 years) knowledge of calcium in relation to health, facilitators and barriers to adequate calcium intake, and to explore both their suggestions for individual strategies to increase calcium intake and ways to communicate calcium-related messaging to this population. Eight gender-specific focus groups (18 men; 35 women) were conducted using a semistructured interview guide, guided by social cognitive theory. Deductive thematic analysis was used to generate themes. Participants perceived adequate calcium intake to be important for children and older adults but were uncertain of the benefits for their own age group. Perceived positive outcomes (e.g., aesthetics such as strong nails) associated with adequate calcium intake were cited as a motivator to increase intake. Perceived barriers to achieving increased calcium intake included the high cost and inconvenience of milk products and negative practices of dairy farmers. Participants suggested planning healthy well-balanced meals and forming a habit of consuming calcium-rich foods as individual strategies to increase calcium intake. Strategies to convey calcium-related information to young adults included increasing awareness of the importance of calcium via credible sources of information and developing nutrition education curricula. Social media and advertising were perceived as ineffective. Our findings provide key information for nutrition education initiatives.

  3. Biological Reactions to Calcium Phosphate-coated Calcium Carbonate Particles

    National Research Council Canada - National Science Library

    Tetsunari NISHIKAWA; Kazuya MASUNO; Tomoharu OKAMURA; Kazuya TOMINAGA; Masahiro WATO; Mayu KOKUBU; Koichi IMAI; Shoji TAKEDA; Yoichro TAGUCHI; Masatoshi UEDA; Akio TANAKA

    2010-01-01

    [SYNOPSIS][Objectives]: In order to histopathologically investigate biological reactions to materials used for scaffolds, we examined the cytotoxicity to calcium particles in vitro and bioabsorption in vivo...

  4. Formate Oxidation-Driven Calcium Carbonate Precipitation by Methylocystis parvus OBBP

    Science.gov (United States)

    Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Arvaniti, Eleni Charalampous; Hosseinkhani, Baharak; Ramos, Jose Angel; Rahier, Hubert

    2014-01-01

    Microbially induced carbonate precipitation (MICP) applied in the construction industry poses several disadvantages such as ammonia release to the air and nitric acid production. An alternative MICP from calcium formate by Methylocystis parvus OBBP is presented here to overcome these disadvantages. To induce calcium carbonate precipitation, M. parvus was incubated at different calcium formate concentrations and starting culture densities. Up to 91.4% ± 1.6% of the initial calcium was precipitated in the methane-amended cultures compared to 35.1% ± 11.9% when methane was not added. Because the bacteria could only utilize methane for growth, higher culture densities and subsequently calcium removals were exhibited in the cultures when methane was added. A higher calcium carbonate precipitate yield was obtained when higher culture densities were used but not necessarily when more calcium formate was added. This was mainly due to salt inhibition of the bacterial activity at a high calcium formate concentration. A maximum 0.67 ± 0.03 g of CaCO3 g of Ca(CHOOH)2−1 calcium carbonate precipitate yield was obtained when a culture of 109 cells ml−1 and 5 g of calcium formate liter−1 were used. Compared to the current strategy employing biogenic urea degradation as the basis for MICP, our approach presents significant improvements in the environmental sustainability of the application in the construction industry. PMID:24837386

  5. Formate oxidation-driven calcium carbonate precipitation by Methylocystis parvus OBBP.

    Science.gov (United States)

    Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Arvaniti, Eleni Charalampous; Hosseinkhani, Baharak; Ramos, Jose Angel; Rahier, Hubert; Boon, Nico

    2014-08-01

    Microbially induced carbonate precipitation (MICP) applied in the construction industry poses several disadvantages such asammonia release to the air and nitric acid production. An alternative MICP from calcium formate by Methylocystis parvus OBBP is presented here to overcome these disadvantages. To induce calcium carbonate precipitation, M. parvus was incubated at different calcium formate concentrations and starting culture densities. Up to 91.4% ± 1.6% of the initial calcium was precipitated in the methane-amended cultures compared to 35.1% ± 11.9% when methane was not added. Because the bacteria could only utilize methane for growth, higher culture densities and subsequently calcium removals were exhibited in the cultures when methane was added. A higher calcium carbonate precipitate yield was obtained when higher culture densities were used but not necessarily when more calcium formate was added. This was mainly due to salt inhibition of the bacterial activity at a high calcium formate concentration. A maximum 0.67 ± 0.03 g of CaCO3 g of Ca(CHOOH)2(-1) calcium carbonate precipitate yield was obtained when a culture of 10(9) cells ml(-1) and 5 g of calcium formate liter(-)1 were used. Compared to the current strategy employing biogenic urea degradation as the basis for MICP, our approach presents significant improvements in the environmental sustainability of the application in the construction industry.

  6. Osteoporosis, calcium and physical activity.

    OpenAIRE

    Martin, A. D.; Houston, C S

    1987-01-01

    Sales of calcium supplements have increased dramatically since 1983, as middle-aged women seek to prevent or treat bone loss due to osteoporosis. However, epidemiologic studies have failed to support the hypothesis that larger amounts of calcium are associated with increased bone density or a decreased incidence of fractures. The authors examine the evidence from controlled trials on the effects of calcium supplementation and physical activity on bone loss and find that weight-bearing activit...

  7. Cardiovascular Effects of Calcium Supplements

    Directory of Open Access Journals (Sweden)

    Ian R. Reid

    2013-07-01

    Full Text Available Calcium supplements reduce bone turnover and slow the rate of bone loss. However, few studies have demonstrated reduced fracture incidence with calcium supplements, and meta-analyses show only a 10% decrease in fractures, which is of borderline statistical and clinical significance. Trials in normal older women and in patients with renal impairment suggest that calcium supplements increase the risk of cardiovascular disease. To further assess their safety, we recently conducted a meta-analysis of trials of calcium supplements, and found a 27%–31% increase in risk of myocardial infarction, and a 12%–20% increase in risk of stroke. These findings are robust because they are based on pre-specified analyses of randomized, placebo-controlled trials and are consistent across the trials. Co-administration of vitamin D with calcium does not lessen these adverse effects. The increased cardiovascular risk with calcium supplements is consistent with epidemiological data relating higher circulating calcium concentrations to cardiovascular disease in normal populations. There are several possible pathophysiological mechanisms for these effects, including effects on vascular calcification, vascular cells, blood coagulation and calcium-sensing receptors. Thus, the non-skeletal risks of calcium supplements appear to outweigh any skeletal benefits, and are they appear to be unnecessary for the efficacy of other osteoporosis treatments.

  8. Laser Sintered Calcium Phosphate Bone

    National Research Council Canada - National Science Library

    Vail, Neil

    1999-01-01

    ...) technology selective laser sintering (SLS). BME has successfully implemented a pilot facility to fabricate calcium phosphate implants using anatomical data coupled with the selective laser sintering process...

  9. 21 CFR 73.1070 - Calcium carbonate.

    Science.gov (United States)

    2010-04-01

    ... precipitated calcium carbonate (CaCO3). (2) Color additive mixtures for drug use made with calcium carbonate... precipitated calcium carbonate in the United States Pharmacopeia XX (1980). (c) Uses and restrictions. Calcium... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Calcium carbonate. 73.1070 Section 73.1070 Food...

  10. 21 CFR 184.1191 - Calcium carbonate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium carbonate. 184.1191 Section 184.1191 Food... Specific Substances Affirmed as GRAS § 184.1191 Calcium carbonate. (a) Calcium carbonate (CaCO3, CAS Reg... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation...

  11. Calcium signalling: fishing out molecules of mitochondrial calcium transport.

    Science.gov (United States)

    Hajnóczky, György; Csordás, György

    2010-10-26

    Cellular energy metabolism, survival and death are controlled by mitochondrial calcium signals originating in the cytoplasm. Now, RNAi studies link three proteins - MICU1, NCLX and LETM1 - to the previously unknown molecular mechanism of mitochondrial calcium transport. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Calcium electroporation in three cell lines; a comparison of bleomycin and calcium, calcium compounds, and pulsing conditions

    DEFF Research Database (Denmark)

    Frandsen, Stine Krog; Gissel, Hanne; Hojman, Pernille

    2013-01-01

    BACKGROUND: Electroporation with calcium (calcium electroporation) can induce ATP depletion-associated cellular death. In the clinical setting, the cytotoxic drug bleomycin is currently used with electroporation (electrochemotherapy) for palliative treatment of tumors. Calcium electroporation off...

  13. Calcium, vitamin D, and your bones

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000490.htm Calcium, vitamin D, and your bones To use the sharing ... and maintain strong bones. How Much Calcium and Vitamin D do I Need? Amounts of calcium are ...

  14. Calcium Supplements: Do Men Need Them Too?

    Science.gov (United States)

    ... Lifestyle Nutrition and healthy eating Should men take calcium supplements? Answers from Katherine Zeratsky, R.D., L. ... Most healthy men don't need to take calcium supplements. Calcium is important for men for optimal ...

  15. Stable prenucleation calcium carbonate clusters.

    Science.gov (United States)

    Gebauer, Denis; Völkel, Antje; Cölfen, Helmut

    2008-12-19

    Calcium carbonate forms scales, geological deposits, biominerals, and ocean sediments. Huge amounts of carbon dioxide are retained as carbonate ions, and calcium ions represent a major contribution to water hardness. Despite its relevance, little is known about the precipitation mechanism of calcium carbonate, and specified complex crystal structures challenge the classical view on nucleation considering the formation of metastable ion clusters. We demonstrate that dissolved calcium carbonate in fact contains stable prenucleation ion clusters forming even in undersaturated solution. The cluster formation can be characterized by means of equilibrium thermodynamics, applying a multiple-binding model, which allows for structural preformation. Stable clusters are the relevant species in calcium carbonate nucleation. Such mechanisms may also be important for the crystallization of other minerals.

  16. A Multiplexed Fluorescent Calcium and NFAT Reporter Gene Assay to Identify GPCR Agonists.

    Science.gov (United States)

    Sheth, Heeral; Gorey, Colleen; Roush, Nicole; Smallman, Shelly; Collantes, Elizabeth; Santoro, Maxine; Olson, Barbara; Fitzgerald, Laura; Lee, Paul H; Shen, Xiqiang John

    2013-01-01

    Intracellular calcium response and resulting calcium signaling to an agonist-GPCR interaction are important for the measurement of compound activity in the GPCR drug development. The increase in cytosol calcium concentration can be measured by the fluorescent calcium indicator dye such as Fluo-4 in a quick assay (in 3-5 minutes) using the fluorescence imaging plate reader. The calcium signaling through the transcription factors such as NFAT that induces gene expression can be measured by the reporter gene assay that links to the expression of reporter enzyme such as the beta-lactamase that requires 5-hour incubation. We have evaluated a multiplexed assay that sequentially measures the calcium response to a GPCR agonist in a rapid fluorescent calcium dye assay, followed by a NFAT beta-lactamase assay, and compared them in the single assay format. We found that the agonist activity determined in the multiplexed assay were comparable with these determined in the single assay format and the Z' factors were all >0.5. Five active compounds were identified that were active in both calcium dye assay and beta-lactamase assay. Therefore, our results demonstrated the utility of this multiplexed calcium assay for screening of GPCR compounds that can cross validate the primary hits and help to eliminate the false positive compounds.

  17. DIHYDROPYRIDINE CALCIUM- CHANNELBLOCKERSFOR ...

    African Journals Online (AJOL)

    assessed by the Mini Mental State Examination 35 If the. MMSE score was 23 or less, then the diagnosis of dementia was ascertained based on the DSM-ill-R criteria.36 In dementia cases the Modified Ischaemic Score}' including a computerised tomography (CD brain scan, served to differentiate vascular.

  18. Calcium digestibility studies utilizing acid-insoluble ash measurements.

    Science.gov (United States)

    Cheng, T K; Coon, C N

    1990-12-01

    Laying hens were individually fed diets providing daily calcium intakes ranging from 2.0 to 4.5 g from two sources of limestone. Silica (washed sand) was added to the diets as filler for hens with less than 4.5 g of daily calcium intake. The calcium digestibility data were obtained both by the total collection (TC) method and b y using acid-insoluble ash (AIA) as an indicator. Source effect was not significant (P greater than .7) within each method tested, and data were pooled for analysis. The calcium digestibility values obtained by the TC method for hens with intake of 2.0, 2.5, 3.0, 3.5, 4.0, and 4.5 g daily were 59.16, 57.31, 54.29, 50.99, 44.63, and 41.76%, respectively. The AIA method consistently yielded higher digestibility values: 73.0, 65.36, 61.78, 54.19, 45.76, and 42.0%. The differences in calcium digestibility values between the two methods were linearly related to the levels of silica consumption (P less than .05).

  19. Calcium metabolism & hypercalcemia in adults.

    Science.gov (United States)

    Lumachi, F; Motta, R; Cecchin, D; Ave, S; Camozzi, V; Basso, S M M; Luisetto, G

    2011-01-01

    Calcium is essential for many metabolic process, including nerve function, muscle contraction, and blood clotting. The metabolic pathways that contribute to maintain serum calcium levels are bone remodeling processes, intestinal absorption and secretion, and renal handling, but hypercalcemia occurs when at least 2 of these 3 metabolic pathways are altered. Calcium metabolism mainly depends on the activity of parathyroid hormone (PTH). Its secretion is strictly controlled by the ionized serum calcium levels through a negative feed-back, which is achieved by the activation of calcium-sensing receptors (CaSRs) mainly expressed on the surface of the parathyroid cells. The PTH receptor in bone and kidney is now referred as PTHR1. The balance of PTH, calcitonin, and vitamin D has long been considered the main regulator of calcium metabolism, but the function of other actors, such as fibroblast growth factor-23 (FGF-23), Klotho, and TPRV5 should be considered. Primary hyperparathyroidism and malignancy are the most common causes of hypercalcemia, accounting for more than 90% of cases. Uncontrolled hypercalcemia may cause renal impairment, both temporary (alteration of renal tubular function) and progressive (relapsing nephrolithiasis), leading to a progressive loss of renal function, as well as severe bone diseases, and heart damages. Advances in the understanding of all actors of calcium homeostasis will be crucial, having several practical consequences in the treatment and prevention of hypercalcemia. This would allow to move from a support therapy, sometimes ineffective, to a specific and addressed therapy, especially in patients with chronic hypercalcemic conditions unsuitable for surgery.

  20. desensitisation and calcium-sensitivity in the isolated perfused rat ...

    African Journals Online (AJOL)

    Dr Olaleye

    1) to 2.35 (for calcium buffer 6); glucose11.1; cocaine, 4μM; propranolol, 1μM; and EDTA. (ethylenediaminetetra-acetic acid disodium salt), 23μM. The composition of the series of buffered salines is shown in table 1. Another saline solution used in some experiments (examining the Ca2+ dependence of the contraction ...

  1. Calcium plus vitamin D supplementation and height loss: findings from the Women's Health Initiative Calcium and Vitamin D clinical trial.

    Science.gov (United States)

    Crandall, Carolyn J; Aragaki, Aaron K; LeBoff, Meryl S; Li, Wenjun; Wactawski-Wende, Jean; Cauley, Jane A; Margolis, Karen L; Manson, JoAnn E

    2016-12-01

    The aim of this study was to determine the associations between calcium + vitamin D supplementation (vs placebo) and height loss in 36,282 participants of the Women's Health Initiative Calcium and Vitamin D trial. Post hoc analysis of data from a double-blind randomized controlled trial of 1,000 mg of elemental calcium as calcium carbonate with 400 IU of vitamin D3 daily (CaD) or placebo in postmenopausal women at 40 US clinical centers. Height was measured annually (mean follow-up 5.9 y) with a stadiometer. Average height loss was 1.28 mm/y among participants assigned to CaD versus 1.26 mm/y for women assigned to placebo (P = 0.35). Effect modification of the CaD intervention was not observed by age, race/ethnicity, or baseline intake of calcium or vitamin D. Randomization to the CaD group did not reduce the risk of clinical height loss (loss of ≥1.5 inches [3.8 cm]: hazard ratio (95% CI) = 1.00 (0.81, 1.23). A strong association (P supplement used in this trial did not prevent height loss in healthy postmenopausal women.

  2. Calcium and Calcium Supplements: Achieving the Right Balance

    Science.gov (United States)

    ... Duyff RL. American Dietetic Association Complete Food and Nutrition Guide. 4th ed. Hoboken, N.J.: John Wiley & Sons; 2012:140. Rosen HN. Calcium and vitamin D supplementation in osteoporosis. http://www.uptodate.com/home/index. ...

  3. Calcium carbonate and calcium sulfate in Martian meteorite EETA79001

    Science.gov (United States)

    Gooding, J. L.; Wentworth, S. J.

    1987-01-01

    Chips of glassy Lithology C of EETA79001 were studied by scanning electron microscopy and energy dispersive X-ray spectroscopy to determine the mineralogy and petrogenesis of the glass that was shown by others to contain trapped Mars-like gases. Calcium carbonite was identified as massive to acicular crystals for which Ca, C, and O were the major elements. Calcium sulfate was identified as prismatic-acicular crystals with Ca and S as the major elements.

  4. Interstate-35 bridge instrumentation renaissance.

    Science.gov (United States)

    2012-09-01

    An updated, accelerometer-based, sensor and data acquisition system was installed and verified on the I-35 Walnut Creek Bridge in Purcell, Oklahoma. The data collection system also includes a microwave communication system to move sensor and video da...

  5. 21 CFR 184.1187 - Calcium alginate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium alginate. 184.1187 Section 184.1187 Food... Specific Substances Affirmed as GRAS § 184.1187 Calcium alginate. (a) Calcium alginate (CAS Reg. No. 9005.... Calcium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control...

  6. Extracellular and Intracellular Regulation of Calcium Homeostasis

    Directory of Open Access Journals (Sweden)

    Felix Bronner

    2001-01-01

    Full Text Available An organism with an internal skeleton must accumulate calcium while maintaining body fluids at a well-regulated, constant calcium concentration. Neither calcium absorption nor excretion plays a significant regulatory role. Instead, isoionic calcium uptake and release by bone surfaces causes plasma calcium to be well regulated. Very rapid shape changes of osteoblasts and osteoclasts, in response to hormonal signals, modulate the available bone surfaces so that plasma calcium can increase when more low-affinity bone calcium binding sites are made available and can decrease when more high-affinity binding sites are exposed. The intracellular free calcium concentration of body cells is also regulated, but because cells are bathed by fluids with vastly higher calcium concentration, their major regulatory mechanism is severe entry restriction. All cells have a calcium-sensing receptor that modulates cell function via its response to extracellular calcium. In duodenal cells, the apical calcium entry structure functions as both transporter and a vitamin D–responsive channel. The channel upregulates calcium entry, with intracellular transport mediated by the mobile, vitamin D–dependent buffer, calbindin D9K, which binds and transports more than 90% of the transcellular calcium flux. Fixed intracellular calcium binding sites can, like the body's skeleton, take up and release calcium that has entered the cell, but the principal regulatory tool of the cell is restricted entry.

  7. Calcium phosphates for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Canillas, M.; Pena, P.; Aza, A.H. de; Rodriguez, M.A.

    2017-07-01

    The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies. (Author)

  8. Polysulfide calcium as multyfunctional product

    Directory of Open Access Journals (Sweden)

    G. Abramova

    2012-12-01

    Full Text Available A modified method of producing of polysulfide calcium, the influence of various factors on the degree of polysulfide of product, as well as possible directions for its use as a multifunctional compound were considered.

  9. [Calcium metabolism after the menopause].

    Science.gov (United States)

    Kanovitch, D; Klotz, H P

    1976-02-16

    The authors recall the antagonism between estradiol and parathormone. Estradiol tends to lower serum calcium and fix calcium in the bones as shown by one of us 25 years ago. The mechanism of this action of estrogen on calcium metabolism has been determined by numerous authors but some points are still not clear, e.g. the interferences between estrogen and calcitonin. Classically, parathormone is known to increase bony reabsorption and raise serum calcium. After the menopause the gradual reduction in estradiol secretion leads to post-menopausal osteoporosis. It is better to administer estrogens prophylactically to women after the menopause provided a cervical smear and mammography have been carried out to eliminate latent carcinoma of the breast or uterine cervix.

  10. Calcium-sensing beyond neurotransmitters

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Han, Weiping

    2009-01-01

    Neurotransmitters, neuropeptides and hormones are released through the regulated exocytosis of SVs (synaptic vesicles) and LDCVs (large dense-core vesicles), a process that is controlled by calcium. Synaptotagmins are a family of type 1 membrane proteins that share a common domain structure. Most....... Also, we discuss potential roles of synaptotagmins in non-traditional endocrine systems....... synaptotagmins are located in brain and endocrine cells, and some of these synaptotagmins bind to phospholipids and calcium at levels that trigger regulated exocytosis of SVs and LDCVs. This led to the proposed synaptotagmin-calcium-sensor paradigm, that is, members of the synaptotagmin family function...... as calcium sensors for the regulated exocytosis of neurotransmitters, neuropeptides and hormones. Here, we provide an overview of the synaptotagmin family, and review the recent mouse genetic studies aimed at understanding the functions of synaptotagmins in neurotransmission and endocrine-hormone secretion...

  11. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium pantothenate, calcium chloride double salt. 172.330 Section 172.330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may...

  12. Calcium affects on vascular endpoints

    Directory of Open Access Journals (Sweden)

    Patel Vaishali B

    2012-03-01

    Full Text Available Abstract Calcium is one of the most abundant minerals in the body and its metabolism is one of the basic biologic processes in humans. Although historically linked primarily to bone structural development and maintenance, calcium is now recognized as a key component of many physiologic pathways necessary for optimum health including cardiovascular, neurological, endocrine, renal, and gastrointestinal systems. A recent meta-analysis published in August 2011 showed a potential increase in cardiovascular events related to calcium supplementation. The possible mechanism of action of this correlation has not been well elucidated. This topic has generated intense interest due to the widespread use of calcium supplements, particularly among the middle aged and elderly who are at the most risk from cardiac events. Prior studies did not control for potential confounding factors such as the use of statins, aspirin or other medications. These controversial results warrant additional well-designed studies to investigate the relationship between calcium supplementation and cardiovascular outcomes. The purpose of this review is to highlight the current literature in regards to calcium supplementation and cardiovascular health; and to identify areas of future research.

  13. Calcium: the molecular basis of calcium action in biology and medicine

    National Research Council Canada - National Science Library

    Pochet, Roland; Donato, Rosario

    2000-01-01

    ... of Calcium Calcium Signalling in Excitable Cells Ca2+ Release in Muscle Cells by N. Macrez and J. Mironneau Calcium Signalling in Neurons Exemplified by Rat Sympathetic Ganglion Cells by S.J. M...

  14. F-35 Pollution Prevention Activities

    Science.gov (United States)

    2008-02-26

    ODC Free Manufacturing •Traditional Aircraft Fabrication Aids, Sealants , and Cleaning Solutions Often ODC-Based •Good Cleanliness and Efficient...Completed SCC and Salt Fog exposure – All F-35 Bushings ɚ.5”Ø Switched to Cold Worked Nitronic 60 – Phase 5 test plan Evaluating Installation Issues • ASC

  15. Presynaptic calcium signalling in cerebellar mossy fibres

    DEFF Research Database (Denmark)

    Thomsen, Louiza Bohn; Jörntell, Henrik; Midtgaard, Jens

    2010-01-01

    Whole-cell recordings were obtained from mossy fibre terminals in adult turtles in order to characterize the basic membrane properties. Calcium imaging of presynaptic calcium signals was carried out in order to analyse calcium dynamics and presynaptic GABA B inhibition. A tetrodotoxin (TTX....... Calcium imaging using Calcium-Green dextran revealed a stimulus-evoked all-or-none TTX-sensitive calcium signal in simple and complex rosettes. All compartments of a complex rosette were activated during electrical activation of the mossy fibre, while individual simple and complex rosettes along an axon...... appeared to be isolated from one another in terms of calcium signalling. CGP55845 application showed that GABA B receptors mediated presynaptic inhibition of the calcium signal over the entire firing frequency range of mossy fibres. A paired-pulse depression of the calcium signal lasting more than 1 s...

  16. Evaluation of calcium ion release and change in pH on combining calcium hydroxide with different vehicles

    Directory of Open Access Journals (Sweden)

    Charu Grover

    2014-01-01

    of 99.53, 17.98, 74.93% respectively with a significant difference among all groups. Group 1 reached the highest Ca 2+ level (39.79% at the end of 1 day but showed almost complete release of calcium hydroxide at the end of 15 days. Group 3 showed least calcium ion release (17.98% at 15 days. Group 4 showed a sustained release of Ca +2 ions from 74% at 15 days to 95% at the end of 30 days. After the 1 st h; Group 1 showed the highest pH level (11.8. However, pH reduced to 7.8 at the end of 30 days in this group. Group 2 showed the highest pH value (10.35, followed by Group 4 (10.32 after 30 days. Conclusion: Chitosan can be used as a promising vehicle for calcium hydroxide to maintain an alkaline pH and to allow sustained release of calcium ions in the root canal system.

  17. Calcium metabolism and cardiovascular function after spaceflight

    Science.gov (United States)

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

    2002-01-01

    To determine the influence of dietary calcium on spaceflight-induced alterations in calcium metabolism and blood pressure (BP), 9-wk-old spontaneously hypertensive rats, fed either high- (2%) or low-calcium (0.02%) diets, were flown on an 18-day shuttle flight. On landing, flight animals had increased ionized calcium (P parathyroid hormone levels (P animals (P = 0.057). However, mean arterial pressure was elevated (P animals fed low- compared with high-calcium diets (P parathyroid hormone was paradoxically increased in the high-calcium-fed flight animals after landing.

  18. [Regulatory mechanism of calcium metabolism.

    Science.gov (United States)

    Ozono, Keiichi

    It is often difficult for terrestrial animals to take enough calcium. To maintain serum or extracellular calcium levels is very important for muscle and nerve function. Two major regulators to increase the serum calcium levels are parathyroid hormone(PTH)and vitamin D. PTH binds to the G protein coupling receptor, PTH1R, and increases intracellular cAMP levels. Impirement in the PTH signalling causes many diseases such as pseudohypoparathyroidism and acrodysostosis with hormone resistance. Vitamin D is activated to 1,25-dihydroxyvitamin D[1,25(OH)2D]by two steps of hydroxylation which occurs in the Liver and Kidney. Then, 1,25(OH)2D binds to vitamin D receptor(VDR), which works as a ligand-dependent transcription factor. Hypocalcemia and hypercalcemia are caused by various disorders including abnormal regulation of PTH and vitamin D production and their signal transduction.

  19. Calcium signaling and cell proliferation.

    Science.gov (United States)

    Pinto, Mauro Cunha Xavier; Kihara, Alexandre Hiroaki; Goulart, Vânia A M; Tonelli, Fernanda M P; Gomes, Katia N; Ulrich, Henning; Resende, Rodrigo R

    2015-11-01

    Cell proliferation is orchestrated through diverse proteins related to calcium (Ca(2+)) signaling inside the cell. Cellular Ca(2+) influx that occurs first by various mechanisms at the plasma membrane, is then followed by absorption of Ca(2+) ions by mitochondria and endoplasmic reticulum, and, finally, there is a connection of calcium stores to the nucleus. Experimental evidence indicates that the fluctuation of Ca(2+) from the endoplasmic reticulum provides a pivotal and physiological role for cell proliferation. Ca(2+) depletion in the endoplasmatic reticulum triggers Ca(2+) influx across the plasma membrane in an phenomenon called store-operated calcium entries (SOCEs). SOCE is activated through a complex interplay between a Ca(2+) sensor, denominated STIM, localized in the endoplasmic reticulum and a Ca(2+) channel at the cell membrane, denominated Orai. The interplay between STIM and Orai proteins with cell membrane receptors and their role in cell proliferation is discussed in this review. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Calcium regulation of muscle contraction.

    Science.gov (United States)

    Szent-Györgyi, A G

    1975-07-01

    Calcium triggers contraction by reaction with regulatory proteins that in the absence of calcium prevent interaction of actin and myosin. Two different regulatory systems are found in different muscles. In actin-linked regulation troponin and tropomyosin regulate actin by blocking sites on actin required for complex formation with myosin; in myosin-linked regulation sites on myosin are blocked in the absence of calcium. The major features of actin control are as follows: there is a requirement for tropomyosin and for a troponin complex having three different subunits with different functions; the actin displays a cooperative behavior; and a movement of tropomyosin occurs controlled by the calcium binding on troponin. Myosin regulation is controlled by a regulatory subunit that can be dissociated in scallop myosin reversibly by removing divalent cations with EDTA. Myosin control can function with pure actin in the absence of tropomyosin. Calcium binding and regulation of molluscan myosins depend on the presence of regulatory light chains. It is proposed that the light chains function by sterically blocking myosin sites in the absence of calcium, and that the "off" state of myosin requires cooperation between the two myosin heads. Both myosin control and actin control are widely distributed in different organisms. Many invertebrates have muscles with both types of regulation. Actin control is absent in the muscles of molluscs and in several minor phyla that lack troponin. Myosin control is not found in striated vertebrate muscles and in the fast muscles of crustacean decapods, although regulatory light chains are present. While in vivo myosin control may not be excluded from vertebrate striated muscles, myosin control may be absent as a result of mutations of the myosin heavy chain.

  1. Counter support for WA35

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    This assembly was equipped with 78 counters, each consisting of a lucite cone, to produce Cerenkov light, and a CsI scintillator plate of 3 mm thickness glued on the face of the cone. The experiment WA35 was set-up in the s1 beam (West Hall) by the Darmstadt-Heidelberg-Virginia-Warsaw Collaboration to measure angular distributions and multiplicities of pions and recoil protons produced by hadrons interacting in nuclei. (See Annual Report 1976 p. 39)

  2. Can total cardiac calcium predict the coronary calcium score?

    Science.gov (United States)

    Pressman, Gregg S; Crudu, Vitalie; Parameswaran-Chandrika, Anoop; Romero-Corral, Abel; Purushottam, Bhaskar; Figueredo, Vincent M

    2011-01-21

    Mitral annular calcification (MAC) shares the same risk factors as atherosclerosis and is associated with coronary artery disease as well as cardiovascular events. However, sensitivity and positive predictive value are low. We hypothesized that a global echocardiographic calcium score would better predict coronary atherosclerotic burden, as assessed by coronary artery calcium score (CAC), than MAC alone. An echocardiographic score was devised to measure global cardiac calcification in a semi-quantitative manner; this included calcification in the aortic valve and root, the mitral valve and annulus, and the sub-mitral apparatus. This score, and a simplified version, were compared with a similar calcification score by CT scan, as well as the CAC. There was a good correlation between the two global calcification scores; the echocardiographic score also correlated with CAC. Using CAC >400 as a measure of severe coronary atherosclerosis, an echocardiographic score ≥5 had a positive predictive value of 60%. Importantly, the simplified score performed equally well (≥3 had a positive predictive value of 62%). Global cardiac calcification, assessed by CT scan or echocardiography, correlates with the extent of coronary calcium. A semi-quantitative calcium score can be easily applied during routine echocardiographic interpretation and can alert the reader to the possibility of severe coronary atherosclerosis. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  3. Calcium ferrite formation from the thermolysis of calcium tris (maleato)

    Indian Academy of Sciences (India)

    stoichiometric quantities of aqueous solutions of calcium maleate, iron(III) maleate and maleic acid. The reaction mixture was concentrated on a water bath until a brown coloured product formed after the addition of excess of acetone. The complex was vacuum dried and its identity was established by chemical analysis.

  4. Calcium ferrite formation from the thermolysis of calcium tris ...

    Indian Academy of Sciences (India)

    Various physico-chemical techniques i.e. TG, DTG, DTA, Mössbauer, XRD, IR etc have been used to study the decomposition behaviour from ambient to 900°C and ferrite formation. Three consecutive decomposition steps leading to the formation of -Fe2O3 and calcium carbonate have been observed at various stages of ...

  5. Estimation of presynaptic calcium currents and endogenous calcium buffers at the frog neuromuscular junction with two different calcium fluorescent dyes

    Directory of Open Access Journals (Sweden)

    Dmitry eSamigullin

    2015-01-01

    Full Text Available At the frog neuromuscular junction, under physiological conditions, the direct measurement of calcium currents and of the concentration of intracellular calcium buffers—which determine the kinetics of calcium concentration and neurotransmitter release from the nerve terminal—has hitherto been technically impossible. With the aim of quantifying both Ca2+ currents and the intracellular calcium buffers, we measured fluorescence signals from nerve terminals loaded with the low-affinity calcium dye Magnesium Green or the high-affinity dye Oregon Green BAPTA-1, simultaneously with microelectrode recordings of nerve-action potentials and end-plate currents. The action-potential-induced fluorescence signals in the nerve terminals developed much more slowly than the postsynaptic response. To clarify the reasons for this observation and to define a spatiotemporal profile of intracellular calcium and of the concentration of mobile and fixed calcium buffers, mathematical modeling was employed. The best approximations of the experimental calcium transients for both calcium dyes were obtained when the calcium current had an amplitude of 1.6 ± 0.08 рА and a half-decay time of 1.2 ± 0.06 ms, and when the concentrations of mobile and fixed calcium buffers were 250 ± 13 µM and 8 ± 0.4 mM, respectively. High concentrations of endogenous buffers define the time course of calcium transients after an action potential in the axoplasm, and may modify synaptic plasticity.

  6. Calcium fertilization increases the concentration of calcium in sapwood and calcium oxalate in foliage of red spruce

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle; Jon H. Connolly; Rakesh Minocha; Jody Jellison

    2009-01-01

    Calcium cycling plays a key role in the health and productivity of red spruce forests in the northeastern US. A portion of the flowpath of calcium within forests includes translocation as Ca2+ in sapwood and accumulation as crystals of calcium oxalate in foliage. Concentrations of Ca in these tree tissues have been used as markers of...

  7. Calcium release from experimental dental materials.

    Science.gov (United States)

    Okulus, Zuzanna; Buchwald, Tomasz; Voelkel, Adam

    2016-11-01

    The calcium release from calcium phosphate-containing experimental dental restorative materials was examined. The possible correlation of ion release with initial calcium content, solubility and degree of curing (degree of conversion) of examined materials was also investigated. Calcium release was measured with the use of an ion-selective electrode in an aqueous solution. Solubility was established by the weighing method. Raman spectroscopy was applied for the determination of the degree of conversion, while initial calcium content was examined with the use of energy-dispersive spectroscopy. For examined materials, the amount of calcium released was found to be positively correlated with solubility and initial calcium content. It was also found that the degree of conversion does not affect the ability of these experimental composites to release calcium ions. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Familial hypocalciuric hypercalcemia and calcium sensing receptor

    DEFF Research Database (Denmark)

    Mrgan, Monija; Nielsen, Sanne; Brixen, Kim

    2014-01-01

    Familial hypocalciuric hypercalcemia (FHH) is a lifelong, benign autosomal dominant disease characterized by hypercalcemia, normal to increased parathyroid hormone level, and a relatively low renal calcium excretion. Inactivation of the calcium-sensing receptor in heterozygous patients results in...

  9. Vitamin D, Calcium, and Bone Health

    Science.gov (United States)

    ... Bone Health Featured Resource Find an Endocrinologist Search Vitamin D, Calcium, and Bone Health March 2012 Download ... also helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin ...

  10. Calcium Binding Ability of Recombinant Buffalo Regucalcin: A Study Using Circular Dichroism Spectroscopy.

    Science.gov (United States)

    Harikrishna, P; Thomas, Jobin; Shende, A M; Bhure, S K

    2017-04-01

    Regucalcin is a calcium regulating multifunctional protein reported to have many important functions like calcium homeostasis, anti-oxidative, anti-apoptotic and anti-cancerous functions. Although it is demonstrated as a calcium regulating protein, the calcium binding ability of regucalcin is still a controversy. The main reason for the controversy is that it lacks a typical EF hand motif which is common to most of the calcium binding proteins. Even though many studies reported regucalcin as a calcium binding protein, there are some studies reporting regucalcin as non-calcium binding also. In the present study, we investigated the calcium binding ability of recombinant buffalo regucalcin by assessing the secondary structural changes of the protein using circular dichroism spectroscopy after adding Ca(2+) to the protein solution. Two types of calcium binding studies were done, one with different concentration of calcium chloride (0.5 mM CaCl2, 1 mM CaCl2, 2 mM CaCl2) and other at different time interval (no incubation and 10 min incubation) after addition of calcium chloride. Significant structural changes were observed in both studies which prove the calcium binding ability of recombinant regucalcin. A constant increase in the α-helix (1.1% with 0.5 mM CaCl2, 1.4% with 1 mM CaCl2, 3.5% with 2 mM CaCl2) and a decrease in β-sheets (78.5% with 0.5 mM CaCl2, 77.4% with 1 mM CaCl2, 75.7% with 2 mM CaCl2) were observed with the increase in calcium chloride concentration. There was a rapid increase in α-helix and decrease in β-sheets immediately after addition of calcium chloride, which subsides after 10 min incubation.

  11. Oxalate co-precipitation synthesis of calcium zirconate and calcium titanate powders.

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Sanchez, Bernadette A.; Tuttle, Bruce Andrew

    2009-06-01

    Fine powders of calcium zirconate (CaZrO{sub 3}, CZ) and calcium titanate (CaTiO{sub 3}, CT) were synthesized using a nonaqueous oxalate co-precipitation route from Ca(NO{sub 3}){sub 2}{center_dot}4 H{sub 2}O and group(IV) n-butoxides (Ti(OBu{sup n}){sub 4} or Zr(OBu{sup n}){sub 4}). Several reaction conditions and batch sizes (2-35 g) were explored to determine their influence on final particle size, morphology, and phase. Characterization of the as-prepared oxalate precursors, oven dried oxalate precursors (60-90 C), and calcined powders (635-900 C) were analyzed with TGA/DTA, XRD, TEM, and SEM. Densification and sintering studies on pressed CZ pellets at 1375 and 1400 C were also performed. Through the developed oxalate co-precipitation route, densification temperatures for CZ were lowered by 125 C from the 1500 C firing temperature required for conventional mixed oxide powders. Low field electrical tests of the CZ pellets indicated excellent dielectric properties with dielectric constants of {approx}30 and a dissipation factor of 0.0004 were measured at 1 kHz.

  12. Studies on magnetic properties of chemically synthesized crystalline calcium ferrite nanoparticles

    Science.gov (United States)

    Debnath, A.; Bera, A.; Chattopadhyay, K. K.; Saha, B.

    2016-05-01

    Spinel-type ferrites have taken a very important role for modern electronic industry. Most of these ferrites exhibit low-loss dielectric properties, high resistivity, low eddy current and also high temperature ferromagnetism. Calcium ferrite is one such important metal oxide which is environmentally safe, chemically stable, low cost and greatly abundant. This outstanding material of calcium ferrite is synthesized by a simple chemical precipitation method using NaOH as the precipitating agent. Ferric chloride anhydrous (FeCl3) and Calcium chloride dihydrate (CaCl2.2H2O) were used as iron and calcium sources respectively. The samples were heated at 200°C for 8h to obtain homogeneous powder of Calcium ferrite. The powders were characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Transmission electrical microscopy (TEM), and Fourier transform infrared spectroscopic (FTIR) measurements. The polycrystalline nature of the sample was confirmed by X-ray diffraction study. The magnetic properties of the sample were investigated by vibrating sample magnetometer (VSM) measurements. Magnetization curve of the prepared sample depicts that as synthesized calcium ferrite nanoparticles have saturation magnetic moment of 1.74 emu/g and the coercivity of 35.08 Oe with superparamagnetic behavior. The synthesized calcium ferrite nanoparticles with such magnetic properties will be a candidate material for different applications in electronics and exploring its functionality in the field of recently developing semiconductor device physics and spintronics.

  13. Studies on magnetic properties of chemically synthesized crystalline calcium ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Debnath, A., E-mail: debnathanimesh@gmail.com [Department of Civil Engineering, National Institute of Technology Agartala, Jirania, West Tripura, 799046 India (India); Bera, A.; Saha, B. [Department of Physics, National Institute of Technology Agartala, Jirania, West Tripura 799046 (India); Chattopadhyay, K. K. [Department of Physics, Jadavpur University, Kolkata 700 032 (India)

    2016-05-23

    Spinel-type ferrites have taken a very important role for modern electronic industry. Most of these ferrites exhibit low-loss dielectric properties, high resistivity, low eddy current and also high temperature ferromagnetism. Calcium ferrite is one such important metal oxide which is environmentally safe, chemically stable, low cost and greatly abundant. This outstanding material of calcium ferrite is synthesized by a simple chemical precipitation method using NaOH as the precipitating agent. Ferric chloride anhydrous (FeCl{sub 3}) and Calcium chloride dihydrate (CaCl{sub 2}.2H{sub 2}O) were used as iron and calcium sources respectively. The samples were heated at 200°C for 8h to obtain homogeneous powder of Calcium ferrite. The powders were characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Transmission electrical microscopy (TEM), and Fourier transform infrared spectroscopic (FTIR) measurements. The polycrystalline nature of the sample was confirmed by X-ray diffraction study. The magnetic properties of the sample were investigated by vibrating sample magnetometer (VSM) measurements. Magnetization curve of the prepared sample depicts that as synthesized calcium ferrite nanoparticles have saturation magnetic moment of 1.74 emu/g and the coercivity of 35.08 Oe with superparamagnetic behavior. The synthesized calcium ferrite nanoparticles with such magnetic properties will be a candidate material for different applications in electronics and exploring its functionality in the field of recently developing semiconductor device physics and spintronics.

  14. Bioactive and Hemocompatible Calcium Sulphoaluminate Cement

    OpenAIRE

    Acuña-Gutiérrez, Iván Omar; Escobedo-Bocardo, José Concepción; Almanza-Robles, José Manuel; Cortés-Hernández, Dora Alicia; Saldívar-Ramírez, Mirna María Guadalupe; Reséndiz-Hernández, Perla Janet; Zugasti-Cruz, Alejandro

    2015-01-01

    Calcium sulphoaluminate cement (CSAC) is an attractive candidate for biomedical applications due to its appropriate mechanical properties and high calcium content. In vitro bioactivity and hemocompatibility of calcium sulphoaluminate cement were assessed. The cement was prepared from a mixture of calcium sulphoaluminate (CSA) clinker, gypsum and water. Cement samples were immersed in a simulated body fluid (SBF) at 37 °C for different periods of time (7, 14 and 21 days). The analyses of these...

  15. Calcium Balance in Chronic Kidney Disease

    OpenAIRE

    Hill Gallant, Kathleen M.; Spiegel, David M.

    2017-01-01

    Purpose of Review The kidneys play a critical role in the balance between the internal milieu and external environment. Kidney failure is known to disrupt a number of homeostatic mechanisms that control serum calcium and normal bone metabolism. However, our understanding of calcium balance throughout the stages of chronic kidney disease is limited and the concept of balance itself, especially with a cation as complex as calcium, is often misunderstood. Both negative and positive calcium balan...

  16. Calcium Balance in Chronic Kidney Disease.

    Science.gov (United States)

    Hill Gallant, Kathleen M; Spiegel, David M

    2017-06-01

    The kidneys play a critical role in the balance between the internal milieu and external environment. Kidney failure is known to disrupt a number of homeostatic mechanisms that control serum calcium and normal bone metabolism. However, our understanding of calcium balance throughout the stages of chronic kidney disease is limited and the concept of balance itself, especially with a cation as complex as calcium, is often misunderstood. Both negative and positive calcium balance have important implications in patients with chronic kidney disease, where negative balance may increase risk of osteoporosis and fracture and positive balance may increase risk of vascular calcification and cardiovascular events. Here, we examine the state of current knowledge about calcium balance in adults throughout the stages of chronic kidney disease and discuss recommendations for clinical strategies to maintain balance as well as future research needs in this area. Recent calcium balance studies in adult patients with chronic kidney disease show that neutral calcium balance is achieved with calcium intake near the recommended daily allowance. Increases in calcium through diet or supplements cause high positive calcium balance, which may put patients at risk for vascular calcification. However, heterogeneity in calcium balance exists among these patients. Given the available calcium balance data in this population, it appears clinically prudent to aim for recommended calcium intakes around 1000 mg/day to achieve neutral calcium balance and avoid adverse effects of either negative or positive calcium balance. Assessment of patients' dietary calcium intake could further equip clinicians to make individualized recommendations for meeting recommended intakes.

  17. Electrochemical Induced Calcium Phosphate Precipitation

    NARCIS (Netherlands)

    Lei, Yang; Song, Bingnan; Weijden, van der Renata D.; Saakes, M.; Buisman, Cees J.N.

    2017-01-01

    Phosphorus (P) is an essential nutrient for living organisms and cannot be replaced or substituted. In this paper, we present a simple yet efficient membrane free electrochemical system for P removal and recovery as calcium phosphate (CaP). This method relies on in situ formation of hydroxide

  18. 21 CFR 582.7187 - Calcium alginate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium alginate. 582.7187 Section 582.7187 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium alginate. (a) Product. Calcium alginate. (b) Conditions of use. This substance is generally...

  19. Abnormalities of serum calcium and magnesium

    Science.gov (United States)

    Neonatal hypocalcemia is defined as a total serum calcium concentration of <7 mg/dL or an ionized calcium concentration of <4 mg/dL (1mmol/L). In very low birth weight (VLBW) infants, ionized calcium values of 0.8 to 1 mmol/L are common and not usually associated with clinical symptoms. In larger in...

  20. Modularized study of human calcium signalling pathway

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    When there is an extracellular change, cells get the message either by introduction of calcium ions into ... as it precipitates phosphate, the established energy currency of cells. Prolonged high intracellular calcium ... trigger proteins upon binding with free calcium ion(s) change their confirmation to modulate enzymes and ion ...

  1. 21 CFR 582.1191 - Calcium carbonate.

    Science.gov (United States)

    2010-04-01

    ... Additives § 582.1191 Calcium carbonate. (a) Product. Calcium carbonate. (b) Conditions of use. This... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium carbonate. 582.1191 Section 582.1191 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

  2. 21 CFR 582.5191 - Calcium carbonate.

    Science.gov (United States)

    2010-04-01

    ... Supplements 1 § 582.5191 Calcium carbonate. (a) Product. Calcium carbonate. (b) Conditions of use. This... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium carbonate. 582.5191 Section 582.5191 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

  3. Mechanism of store-operated calcium entry

    Indian Academy of Sciences (India)

    Activation of receptors coupled to the phospholipase C/IP3 signalling pathway results in a rapid release of calcium from its intracellular stores, eventually leading to depletion of these stores. Calcium store depletion triggers an influx of extracellular calcium across the plasma membrane, a mechanism known as the ...

  4. Mitochondrial Calcium Sparkles Light Up Astrocytes.

    Science.gov (United States)

    MacVicar, Brian A; Ko, Rebecca W Y

    2017-02-27

    Discrete calcium signals in the fine processes of astrocytes are a recent discovery and a new mystery. In a recent issue of Neuron, Agarwal et al. (2017) report that calcium efflux from mitochondria during brief openings of the mitochondrial permeability transition pore (mPTP) contribute to calcium microdomains. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  5. 21 CFR 182.1217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium phosphate. 182.1217 Section 182.1217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic). (b...

  6. 21 CFR 582.1217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phosphate. 582.1217 Section 582.1217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1217 Calcium phosphate. (a) Product. Calcium phosphate (mono-, di-, and tribasic). (b...

  7. ORIGINAL ARTICLES Calcium supplementation to prevent pre ...

    African Journals Online (AJOL)

    ORIGINAL ARTICLES. Calcium supplementation to prevent pre-eclampsia - a systematic review. G J Hofmeyr, A Roodt, A N Atallah, L Duley. Background. Calcium supplementation during pregnancy may prevent high blood pressure and preterm labour. Objective. To assess the effects of calcium supplementation.

  8. Calcium Orthophosphate-Based Bioceramics

    Directory of Open Access Journals (Sweden)

    Sergey V. Dorozhkin

    2013-09-01

    Full Text Available Various types of grafts have been traditionally used to restore damaged bones. In the late 1960s, a strong interest was raised in studying ceramics as potential bone grafts due to their biomechanical properties. A bit later, such synthetic biomaterials were called bioceramics. In principle, bioceramics can be prepared from diverse materials but this review is limited to calcium orthophosphate-based formulations only, which possess the specific advantages due to the chemical similarity to mammalian bones and teeth. During the past 40 years, there have been a number of important achievements in this field. Namely, after the initial development of bioceramics that was just tolerated in the physiological environment, an emphasis was shifted towards the formulations able to form direct chemical bonds with the adjacent bones. Afterwards, by the structural and compositional controls, it became possible to choose whether the calcium orthophosphate-based implants remain biologically stable once incorporated into the skeletal structure or whether they were resorbed over time. At the turn of the millennium, a new concept of regenerative bioceramics was developed and such formulations became an integrated part of the tissue engineering approach. Now calcium orthophosphate scaffolds are designed to induce bone formation and vascularization. These scaffolds are often porous and harbor different biomolecules and/or cells. Therefore, current biomedical applications of calcium orthophosphate bioceramics include bone augmentations, artificial bone grafts, maxillofacial reconstruction, spinal fusion, periodontal disease repairs and bone fillers after tumor surgery. Perspective future applications comprise drug delivery and tissue engineering purposes because calcium orthophosphates appear to be promising carriers of growth factors, bioactive peptides and various types of cells.

  9. Morphological Investigation of Calcium Carbonate during Ammonification-Carbonization Process of Low Concentration Calcium Solution

    OpenAIRE

    Huaigang Cheng; Xiaoxi Zhang; Huiping Song

    2014-01-01

    Ultrafine calcium carbonate is a widely used cheap additive. The research is conducted in low degree supersaturation solution in order to study the polymorphic phases’ change and its factors of the calcium carbonate precipitate in the ammonification-carbonization process of the solution with calcium. Fine particles of calcium carbonate are made in the solution containing 0.015 mol/L of Ca2+. Over 98% of the calcium carbonate precipitate without ammonification resembles the morphology of calci...

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

    Science.gov (United States)

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

    2002-01-01

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

  11. Mammary-Specific Ablation of the Calcium-Sensing Receptor During Lactation Alters Maternal Calcium Metabolism, Milk Calcium Transport, and Neonatal Calcium Accrual

    Science.gov (United States)

    Mamillapalli, Ramanaiah; VanHouten, Joshua; Dann, Pamela; Bikle, Daniel; Chang, Wenhan; Brown, Edward

    2013-01-01

    To meet the demands for milk calcium, the lactating mother adjusts systemic calcium and bone metabolism by increasing dietary calcium intake, increasing bone resorption, and reducing renal calcium excretion. As part of this adaptation, the lactating mammary gland secretes PTHrP into the maternal circulation to increase bone turnover and mobilize skeletal calcium stores. Previous data have suggested that, during lactation, the breast relies on the calcium-sensing receptor (CaSR) to coordinate PTHrP secretion and milk calcium transport with calcium availability. To test this idea genetically, we bred BLG-Cre mice with CaSR-floxed mice to ablate the CaSR specifically from mammary epithelial cells only at the onset of lactation (CaSR-cKO mice). Loss of the CaSR in the lactating mammary gland did not disrupt alveolar differentiation or milk production. However, it did increase the secretion of PTHrP into milk and decreased the transport of calcium from the circulation into milk. CaSR-cKO mice did not show accelerated bone resorption, but they did have a decrease in bone formation. Loss of the mammary gland CaSR resulted in hypercalcemia, decreased PTH secretion, and increased renal calcium excretion in lactating mothers. Finally, loss of the mammary gland CaSR resulted in decreased calcium accrual by suckling neonates, likely due to the combination of increased milk PTHrP and decreased milk calcium. These results demonstrate that the mammary gland CaSR coordinates maternal bone and calcium metabolism, calcium transport into milk, and neonatal calcium accrual during lactation. PMID:23782944

  12. Apatite Formation from Amorphous Calcium Phosphate and Mixed Amorphous Calcium Phosphate/Amorphous Calcium Carbonate.

    Science.gov (United States)

    Ibsen, Casper J S; Chernyshov, Dmitry; Birkedal, Henrik

    2016-08-22

    Crystallization from amorphous phases is an emerging pathway for making advanced materials. Biology has made use of amorphous precursor phases for eons and used them to produce structures with remarkable properties. Herein, we show how the design of the amorphous phase greatly influences the nanocrystals formed therefrom. We investigate the transformation of mixed amorphous calcium phosphate/amorphous calcium carbonate phases into bone-like nanocrystalline apatite using in situ synchrotron X-ray diffraction and IR spectroscopy. The speciation of phosphate was controlled by pH to favor HPO4 (2-) . In a carbonate free system, the reaction produces anisotropic apatite crystallites with large aspect ratios. The first formed crystallites are highly calcium deficient and hydrogen phosphate rich, consistent with thin octacalcium phosphate (OCP)-like needles. During growth, the crystallites become increasingly stoichiometric, which indicates that the crystallites grow through addition of near-stoichiometric apatite to the OCP-like initial crystals through a process that involves either crystallite fusion/aggregation or Ostwald ripening. The mixed amorphous phases were found to be more stable against phase transformations, hence, the crystallization was inhibited. The resulting crystallites were smaller and less anisotropic. This is rationalized by the idea that a local phosphate-depletion zone formed around the growing crystal until it was surrounded by amorphous calcium carbonate, which stopped the crystallization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Computational study of a calcium release-activated calcium channel

    Science.gov (United States)

    Talukdar, Keka; Shantappa, Anil

    2016-05-01

    The naturally occurring proteins that form hole in membrane are commonly known as ion channels. They play multiple roles in many important biological processes. Deletion or alteration of these channels often leads to serious problems in the physiological processes as it controls the flow of ions through it. The proper maintenance of the flow of ions, in turn, is required for normal health. Here we have investigated the behavior of a calcium release-activated calcium ion channel with pdb entry 4HKR in Drosophila Melanogaster. The equilibrium energy as well as molecular dynamics simulation is performed first. The protein is subjected to molecular dynamics simulation to find their energy minimized value. Simulation of the protein in the environment of water and ions has given us important results too. The solvation energy is also found using Charmm potential.

  14. The Calcium Wave of Vegetable Cells

    Directory of Open Access Journals (Sweden)

    TD. Geydan

    2007-08-01

    Full Text Available Calcium is an essential nutrient for plants; it is involved in developmental processes and in responses to biotic and abiotic factors. Several signals that modify the calcium concentration in the cytoplasm, endoplasmic reticulum, nucleus and/or plastids have been observed. These changes in the calcium concentration in the cell interior are rapidly returned to basal levels, in the meantime, innumerable and complex signaling cascades. This note exposes the mechanisms of calcium transport through the cell membranes of the entrance of calcium in the plant cells.

  15. 40 CFR 35.925-12 - Property.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Property. 35.925-12 Section 35.925-12... ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-12 Property. That the... property requirements of § 35.935-3. ...

  16. 40 CFR 35.662 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... ASSISTANCE Environmental Program Grants for Tribes Pollution Prevention Grants (section 6605) § 35.662 Definitions. The following definition applies to the Pollution Prevention Grant program and to §§ 35.660... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Definitions. 35.662 Section 35.662...

  17. 40 CFR 35.2116 - Collection system.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Collection system. 35.2116 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2116 Collection system. Except as provided in § 35.2032(c), if the project involves collection system work, such work: (a) Shall...

  18. 40 CFR 35.936-4 - Profits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Profits. 35.936-4 Section 35.936-4... ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.936-4 Profits. Only fair and reasonable profits may be earned by contractors in subagreements under EPA grants. See § 35.937-7 for...

  19. Calcium Intake in the Moroccan Elderly

    Directory of Open Access Journals (Sweden)

    Sebbar El-houcine

    2017-08-01

    Full Text Available Introduction: Calcium intakes of elderly people are often below the recommendations which are 1200 mg/day. The advancing age may be accompanied by a loss of capacity to absorb additional calcium in case of deficiency. The aim of our work is to evaluate the calcium intake in the Moroccan elderly. Methods: The version translated into Arabic dialect Fardellone questionnaire is tested on a sample of 159 subjects aged over 60 years. Results: The study population includes 87 women (55%, 72 men (45%. The mean calcium intake was respectively 3078 mg by week (that means 440 mg/day. The assessment of calcium intake showed a deficiency and the average consumption of calcium per day is significantly lower than the recommended daily amount for this population. The comparison of both gender found a deficit higher among women than among men. Conclusion: Evaluation of the calcium intake is an essential tool for better management of metabolic bone diseases.

  20. Calcium Impact on Milk Gels Formation

    DEFF Research Database (Denmark)

    Koutina, Glykeria

    Calcium is one of the several elements that can be found in milk distributed between the micellar and the serum milk phase. Calcium is important from a nutritional point of view, but its contribution to the functional and structural properties of dairy products has only recently been...... acknowledgement. The presence of calcium in a dynamic equilibrium between the serum and the micellar milk phase make the distribution susceptible to certain physicochemical conditions and to technological treatments of milk resulting in fluctuations in pH and temperature and also sensitive to addition of calcium...... salts. The perturbation of calcium equilibria by these factors will affect the final properties of acid, calcium and rennet milk gels. By decreasing the pH from 6.0 to 5.2 (acid gels), the calcium equilibrium was significantly affected by temperature (4, 20, 30, 40 oC), and different combinations...

  1. Exopolysaccharides regulate calcium flow in cariogenic biofilms.

    Science.gov (United States)

    Astasov-Frauenhoffer, Monika; Varenganayil, Muth M; Decho, Alan W; Waltimo, Tuomas; Braissant, Olivier

    2017-01-01

    Caries-associated biofilms induce loss of calcium from tooth surfaces in the presence of dietary carbohydrates. Exopolysaccharides (EPS) provide a matrix scaffold and an abundance of primary binding sites within biofilms. The role of EPS in binding calcium in cariogenic biofilms is only partially understood. Thus, the aim of the present study is to investigate the relationship between the calcium dissolution rates and calcium tolerance of caries-associated bacteria and yeast as well as to examine the properties of EPS to quantify its binding affinity for dissolved calcium. Calcium dissolution was measured by dissolution zones on Pikovskaya's agar. Calcium tolerance was assessed by isothermal microcalorimetry (IMC) by adding CaCl2 to the bacterial cultures. Acid-base titration and Fourier transform infrared (FTIR) spectroscopy were used to identify possible functional groups responsible for calcium binding, which was assessed by isothermal titration calorimetry (ITC). Lactobacillus spp. and mutans streptococci demonstrated calcium dissolution in the presence of different carbohydrates. All strains that demonstrated high dissolution rates also revealed higher rates of calcium tolerance by IMC. In addition, acidic functional groups were predominantly identified as possible binding sites for calcium ions by acid-base titration and FTIR. Finally, ITC revealed EPS to have a higher binding affinity for calcium compared, for example, to lactic acid. In conclusion, this study illustrates the role of EPS in terms of the calcium tolerance of cariogenic microbiota by determining the ability of EPS to control free calcium concentrations within the biofilms as a self-regulating mode of action in the pathogenesis of dental caries.

  2. Exopolysaccharides regulate calcium flow in cariogenic biofilms.

    Directory of Open Access Journals (Sweden)

    Monika Astasov-Frauenhoffer

    Full Text Available Caries-associated biofilms induce loss of calcium from tooth surfaces in the presence of dietary carbohydrates. Exopolysaccharides (EPS provide a matrix scaffold and an abundance of primary binding sites within biofilms. The role of EPS in binding calcium in cariogenic biofilms is only partially understood. Thus, the aim of the present study is to investigate the relationship between the calcium dissolution rates and calcium tolerance of caries-associated bacteria and yeast as well as to examine the properties of EPS to quantify its binding affinity for dissolved calcium. Calcium dissolution was measured by dissolution zones on Pikovskaya's agar. Calcium tolerance was assessed by isothermal microcalorimetry (IMC by adding CaCl2 to the bacterial cultures. Acid-base titration and Fourier transform infrared (FTIR spectroscopy were used to identify possible functional groups responsible for calcium binding, which was assessed by isothermal titration calorimetry (ITC. Lactobacillus spp. and mutans streptococci demonstrated calcium dissolution in the presence of different carbohydrates. All strains that demonstrated high dissolution rates also revealed higher rates of calcium tolerance by IMC. In addition, acidic functional groups were predominantly identified as possible binding sites for calcium ions by acid-base titration and FTIR. Finally, ITC revealed EPS to have a higher binding affinity for calcium compared, for example, to lactic acid. In conclusion, this study illustrates the role of EPS in terms of the calcium tolerance of cariogenic microbiota by determining the ability of EPS to control free calcium concentrations within the biofilms as a self-regulating mode of action in the pathogenesis of dental caries.

  3. Calcium precipitate induced aerobic granulation.

    Science.gov (United States)

    Wan, Chunli; Lee, Duu-Jong; Yang, Xue; Wang, Yayi; Wang, Xingzu; Liu, Xiang

    2015-01-01

    Aerobic granulation is a novel biotechnology for wastewater treatment. This study refined existing aerobic granulation mechanisms as a sequencing process including formation of calcium precipitate under alkaline pH to form inorganic cores, followed by bacterial attachment and growth on these cores to form the exopolysaccharide matrix. Mature granules comprised an inner core and a matrix layer and a rim layer with enriched microbial strains. The inorganic core was a mix of different crystals of calcium and phosphates. Functional strains including Sphingomonas sp., Paracoccus sp. Sinorhizobium americanum strain and Flavobacterium sp. attached onto the cores. These functional strains promote c-di-GMP production and the expression by Psl and Alg genes for exopolysaccharide production to enhance formation of mature granules. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Testosterone increases urinary calcium excretion and inhibits expression of renal calcium transport proteins

    DEFF Research Database (Denmark)

    Hsu, Yu-Juei; Dimke, Henrik Anthony; Schoeber, Joost P H

    2010-01-01

    Although gender differences in the renal handling of calcium have been reported, the overall contribution of androgens to these differences remains uncertain. We determined here whether testosterone affects active renal calcium reabsorption by regulating calcium transport proteins. Male mice had...... higher urinary calcium excretion than female mice and their renal calcium transporters were expressed at a lower level. We also found that orchidectomized mice excreted less calcium in their urine than sham-operated control mice and that the hypocalciuria was normalized after testosterone replacement...... calcium transport. Thus, our study shows that gender differences in renal calcium handling are, in part, mediated by the inhibitory actions of androgens on TRPV5-mediated active renal calcium transport....

  5. A Closer look at calcium absorption and the benefits and risks of dietary versus supplemental calcium.

    Science.gov (United States)

    Booth, Anna; Camacho, Pauline

    2013-11-01

    To perform a thorough search of the literature on calcium research and specifically address the topic of calcium absorption. PubMed and Ovid were the main engines used for primary literature searches; textbooks, review articles, and book chapters are examples of the other sources used for supplemental information. Regarding calcium absorption, it seems apparent that the absorption efficiency of all calcium salts, regardless of solubility, is fairly equivalent and not significantly less than the absorption efficiency of dietary calcium. However, dietary calcium has been shown to have greater impact in bone building than supplemental calcium. This is likely due to improved absorption with meals and the tendency of people to intake smaller amounts more frequently, which is more ideal for the body's method of absorption. In addition, the cardiovascular risks of excessive calcium intake appear to be more closely related to calcium supplements than dietary calcium; this relationship continues to be controversial in the literature. We conclude that further studies are needed for direct comparison of supplemental and dietary calcium to fully establish if one is superior to the other with regard to improving bone density. We also propose further studies on the cardiovascular risk of long-term increased calcium intake and on physician estimates of patients' daily calcium intake to better pinpoint those patients who require calcium supplementation.

  6. CCN3 and calcium signaling

    Directory of Open Access Journals (Sweden)

    Li Chang Long

    2003-08-01

    Full Text Available Abstract The CCN family of genes consists presently of six members in human (CCN1-6 also known as Cyr61 (Cystein rich 61, CTGF (Connective Tissue Growth Factor, NOV (Nephroblastoma Overexpressed gene, WISP-1, 2 and 3 (Wnt-1 Induced Secreted Proteins. Results obtained over the past decade have indicated that CCN proteins are matricellular proteins, which are involved in the regulation of various cellular functions, such as proliferation, differentiation, survival, adhesion and migration. The CCN proteins have recently emerged as regulatory factors involved in both internal and external cell signaling. CCN3 was reported to physically interact with fibulin-1C, integrins, Notch and S100A4. Considering that, the conformation and biological activity of these proteins are dependent upon calcium binding, we hypothesized that CCN3 might be involved in signaling pathways mediated by calcium ions. In this article, we review the data showing that CCN3 regulates the levels of intracellular calcium and discuss potential models that may account for the biological effects of CCN3.

  7. Kinetics of calcium sulfoaluminate formation from tricalcium aluminate, calcium sulfate and calcium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuerun, E-mail: xuerunli@163.com; Zhang, Yu; Shen, Xiaodong, E-mail: xdshen@njut.edu.cn; Wang, Qianqian; Pan, Zhigang

    2014-01-15

    The formation kinetics of tricalcium aluminate (C{sub 3}A) and calcium sulfate yielding calcium sulfoaluminate (C{sub 4}A{sub 3}$) and the decomposition kinetics of calcium sulfoaluminate were investigated by sintering a mixture of synthetic C{sub 3}A and gypsum. The quantitative analysis of the phase composition was performed by X-ray powder diffraction analysis using the Rietveld method. The results showed that the formation reaction 3Ca{sub 3}Al{sub 2}O{sub 6} + CaSO{sub 4} → Ca{sub 4}Al{sub 6}O{sub 12}(SO{sub 4}) + 6CaO was the primary reaction < 1350 °C with and activation energy of 231 ± 42 kJ/mol; while the decomposition reaction 2Ca{sub 4}Al{sub 6}O{sub 12}(SO{sub 4}) + 10CaO → 6Ca{sub 3}Al{sub 2}O{sub 6} + 2SO{sub 2} ↑ + O{sub 2} ↑ primarily occurred beyond 1350 °C with an activation energy of 792 ± 64 kJ/mol. The optimal formation region for C{sub 4}A{sub 3}$ was from 1150 °C to 1350 °C and from 6 h to 1 h, which could provide useful information on the formation of C{sub 4}A{sub 3}$ containing clinkers. The Jander diffusion model was feasible for the formation and decomposition of calcium sulfoaluminate. Ca{sup 2+} and SO{sub 4}{sup 2−} were the diffusive species in both the formation and decomposition reactions. -- Highlights: •Formation and decomposition of calcium sulphoaluminate were studied. •Decomposition of calcium sulphoaluminate combined CaO and yielded C{sub 3}A. •Activation energy for formation was 231 ± 42 kJ/mol. •Activation energy for decomposition was 792 ± 64 kJ/mol. •Both the formation and decomposition were controlled by diffusion.

  8. Clogging and Cementation Caused by Calcium or Iron Biogrouts

    Science.gov (United States)

    Ivanov, V.; Chu, J.; Naeimi, M.

    2012-12-01

    Chemical grouts are often used to reduce the hydraulic conductivity of soil for seepage control purposes. However, chemical grouts can be expensive and environmentally unfriendly. Therefore, two new biogrouts were tested for their bioclogging and biocementation properties. The first was calcium-based biogrout, which contained urease-producing bacteria, calcium chloride and urea for the crystallization of calcite due to enzymatic hydrolysis of urea. The second was iron-based biogrout, which consisted of urease-producing bacteria, ferric chelate, and urea for the precipitation of ferric hydroxide and carbonate due to enzymatic hydrolysis of urea. The permeability of sand (P, 10^-5 m/s), treated with calcium-based biogrout, linearly decreased as a function of the content of precipitated calcium (C, % w/w) according to the following equation: P = 5.1 - 4.0 C. Meanwhile, the permeability of sand treated with iron-based biogrout dropped to 2.7x10^-6 m/s at content of precipitated iron (F, % w/w) about 0.35 % w/w , by the equation: P = 5.1 - 14.6 F , and then slowly decreased to 1.4x10^-7 m/s at content of precipitated iron 1.8% w/w by the following equation: P = 0.36 - 0.23F. Both biogrouts have approximately same efficiency in the reduction of permeability of sand to low values. However, the mechanisms of bioclogging are probably different because the reduction of permeability by calcium-based biogrout was described by linear function of precipitated calcium but the reduction of permeability by iron-based biogrout showed two steps of the clogging. Different functions and mechanisms were related probably to the different type of precipitates. The images of biogrouted sand samples show that calcium-based biogrout produced white amorphous or crystallised calcium carbonate, while iron-based biogrout produced gel-like brown precipitate without visible crystals. The unconfined compressive strengths of the sand treated with different biogrouts (Y, kPa) increased by power

  9. The Role of Calcium in Osteoporosis

    Science.gov (United States)

    Arnaud, C. D.; Sanchez, S. D.

    1991-01-01

    Calcium requirements may vary throughout the lifespan. During the growth years and up to age 25 to 30, it is important to maximize dietary intake of calcium to maintain positive calcium balance and achieve peak bone mass, thereby possibly decreasing the risk of fracture when bone is subsequently lost. Calcium intake need not be greater than 800 mg/day during the relatively short period of time between the end of bone building and the onset of bone loss (30 to 40 years). Starting at age 40 to 50, both men and women lose bone slowly, but women lose bone more rapidly around the menopause and for about 10 years after. Intestinal calcium absorption and the ability to adapt to low calcium diets are impaired in many postmenopausal women and elderly persons owing to a suspected functional or absolute decrease in the ability of the kidney to produce 1,25(OH)2D2. The bones then become more and more a source of calcium to maintain critical extracellular fluid calcium levels. Excessive dietary intake of protein and fiber may induce significant negative calcium balance and thus increase dietary calcium requirements. Generally, the strongest risk factors for osteoporosis are uncontrollable (e.g., sex, age, and race) or less controllable (e.g., disease and medications). However, several factors such as diet, physical activity, cigarette smoking, and alcohol use are lifestyle related and can be modified to help reduce the risk of osteoporosis.

  10. Assessment of calcium intake by adolescents

    Directory of Open Access Journals (Sweden)

    Cristiane Franco de Oliveira

    2014-06-01

    Full Text Available OBJECTIVE: To evaluate the daily calcium intake of adolescents in schools from Chapecó, Santa Catarina, Southern Brazil, to check if calcium intake is in accordance with the Dietary Reference Intakes (DRI, and to investigate variables associated with daily calcium intake.METHODS: Cross-sectional study approved by the Institutional Review Board and developed in 2010. Students of the 8th grade completed questionnaires with personal data and questions about the calcium-rich foods intake frequency. In order to compare students with adequate (1300mg or inadequate intake of calcium/day (<1300mg, parametric and nonparametric tests were used.RESULTS: A total of 214 students with a mean age of 14.3±1.0 years were enrolled. The median daily calcium intake was 540mg (interquartile range - IQ: 312-829mg and only 25 students (11.7% had calcium intake within the recommendations of the DRI for age. Soft drink consumption ≥3 times/week was associated with a lower intake of calcium.CONCLUSIONS: Few students ingested adequate levels of calcium for the age group. It is necessary to develop a program to encourage a greater intake of calcium-rich foods in adolescence.

  11. The Risks and Benefits of Calcium Supplementation

    Directory of Open Access Journals (Sweden)

    Chan Soo Shin

    2015-03-01

    Full Text Available The association between calcium supplementation and adverse cardiovascular events has recently become a topic of debate due to the publication of two epidemiological studies and one meta-analysis of randomized controlled clinical trials. The reports indicate that there is a significant increase in adverse cardiovascular events following supplementation with calcium; however, a number of experts have raised several issues with these reports such as inconsistencies in attempts to reproduce the findings in other populations and questions concerning the validity of the data due to low compliance, biases in case ascertainment, and/or a lack of adjustment. Additionally, the Auckland Calcium Study, the Women's Health Initiative, and many other studies included in the meta-analysis obtained data from calcium-replete subjects and it is not clear whether the same risk profile would be observed in populations with low calcium intakes. Dietary calcium intake varies widely throughout the world and it is especially low in East Asia, although the risk of cardiovascular events is less prominent in this region. Therefore, clarification is necessary regarding the occurrence of adverse cardiovascular events following calcium supplementation and whether this relationship can be generalized to populations with low calcium intakes. Additionally, the skeletal benefits from calcium supplementation are greater in subjects with low calcium intakes and, therefore, the risk-benefit ratio of calcium supplementation is likely to differ based on the dietary calcium intake and risks of osteoporosis and cardiovascular diseases of various populations. Further studies investigating the risk-benefit profiles of calcium supplementation in various populations are required to develop population-specific guidelines for individuals of different genders, ages, ethnicities, and risk profiles around the world.

  12. Calcium Carbonate versus Sevelamer Hydrochloride as Phosphate Binders after Long-Term Disease Progression in 5/6 Nephrectomized Rats

    Directory of Open Access Journals (Sweden)

    Suvi Törmänen

    2014-01-01

    Full Text Available Our aim was to compare the effects of calcium carbonate and sevelamer-HCl treatments on calcium-phosphate metabolism and renal function in 5/6 nephrectomized (NX rats so that long-term disease progression preceded the treatment. After 15-week progression, calcium carbonate (3.0%, sevelamer-HCl (3.0%, or control diets (0.3% calcium were given for 9 weeks. Subtotal nephrectomy reduced creatinine clearance (−40%, plasma calcidiol (−25%, and calcitriol (−70% and increased phosphate (+37%, parathyroid hormone (PTH (11-fold, and fibroblast growth factor-23 (FGF-23 (4-fold. In NX rats, calcium carbonate diet increased plasma (+20% and urinary calcium (6-fold, reduced plasma phosphate (−50% and calcidiol (−30%, decreased creatinine clearance (−35% and FGF 23 (−85%, and suppressed PTH without influencing blood pH. In NX rats, sevelamer-HCl increased urinary calcium (4-fold and decreased creatinine clearance (−45%, PTH (−75%, blood pH (by 0.20 units, plasma calcidiol (−40%, and calcitriol (−65%. Plasma phosphate and FGF-23 were unchanged. In conclusion, when initiated after long-term progression of experimental renal insufficiency, calcium carbonate diet reduced plasma phosphate and FGF-23 while sevelamer-HCl did not. The former induced hypercalcemia, the latter induced acidosis, while both treatments reduced vitamin D metabolites and deteriorated renal function. Thus, delayed initiation influences the effects of these phosphate binders in remnant kidney rats.

  13. Effect of timing of administered calcium lactate on the sucrose-induced intraoral demineralization of bovine enamel.

    Science.gov (United States)

    Kashket, S; Yaskell, T

    1992-03-01

    A number of soluble calcium salts are known to reduce the demineralization of enamel in the mouth. The present study was undertaken to examine the effects of rinses containing different concentrations of calcium lactate, and the time of giving the rinses with respect to sucrose challenges. Subjects wore palatal appliances containing blocks of bovine enamel whose surfaces were covered with Streptococcus mutans IB 1600, and rinsed with 10% sucrose for 1 min. Changes in iodide penetrability of the enamel, and the pH and extracellular ion concentrations of the streptococcal plaque were determined. When added to the sucrose rinse, 100 or 150 mM calcium lactate reduced demineralization by about 35%, although the plaque pH was not affected. Plaque calcium was elevated but diffused away rapidly so that concentrations after 45 min were close to control values. Plaque inorganic phosphate and lactate were not affected. Ongoing demineralization appeared to be stopped when 100 mM calcium lactate was given 15 min after the sucrose rinse. When the lactate was given 15 min before the sucrose rinse, demineralization was reduced by only about 25%, consistent with the rapid diffusion of plaque calcium. The combination of (i) pretreatment with calcium lactate and (ii) admixture of calcium lactate with sucrose was most effective. Demineralization was reduced about 55% with 100 mM calcium lactate under these conditions, and protective effects were seen with as little as 25 mM. In summary, the findings demonstrate the enamel-protective effect of relatively low concentrations of calcium lactate, and point to the need to sustain a high plaque calcium during periods of maximum acidogenicity.

  14. Calcium signals can freely cross the nuclear envelope in hippocampal neurons: somatic calcium increases generate nuclear calcium transients

    OpenAIRE

    Eder, Anja; Bading, Hilmar

    2007-01-01

    Abstract Background In hippocampal neurons, nuclear calcium signaling is important for learning- and neuronal survival-associated gene expression. However, it is unknown whether calcium signals generated by neuronal activity at the cell membrane and propagated to the soma can unrestrictedly cross the nuclear envelope to invade the nucleus. The nuclear envelope, which allows ion transit via the nuclear pore complex, may represent a barrier for calcium and has been suggested to insulate the nuc...

  15. Mechanisms of calcium sequestration by isolated Malpighian tubules of the house cricket Acheta domesticus.

    Science.gov (United States)

    Browne, Austin; O'Donnell, Michael J

    2018-01-01

    Hemolymph calcium homeostasis in insects is achieved by the Malpighian tubules, primarily by sequestering excess Ca 2+ within internal calcium stores (Ca-rich granules) most often located within type I (principal) tubule cells. Using both the scanning ion-selective electrode technique and the Ramsay secretion assay this study provides the first measurements of basolateral and transepithelial Ca 2+ fluxes across the Malpighian tubules of an Orthopteran insect, the house cricket Acheta domesticus. Ca 2+ transport was specific to midtubule segments, where 97% of the Ca 2+ entering the tubule is sequestered within intracellular calcium stores and the remaining 3% is secreted into the lumen. Antagonists of voltage-gated (L-type) calcium channels decreased Ca 2+ influx ≥fivefold in adenosine 3',5'-cyclic monophosphate (cAMP)-stimulated tubules, suggesting basolateral Ca 2+ influx is facilitated by voltage-gated Ca 2+ channels. Increasing fluid secretion through manipulation of intracellular levels of cAMP or Ca 2+ had opposite effects on tubule Ca 2+ transport. The adenylyl cyclase-cAMP-PKA pathway promotes Ca 2+ sequestration whereas both 5-hydroxytryptamine and thapsigargin inhibited sequestration. Our results suggest that the midtubules of Acheta domesticus are dynamic calcium stores, which maintain hemolymph calcium concentration by manipulating rates of Ca 2+ sequestration through stimulatory (cAMP) and inhibitory (Ca 2+ ) regulatory pathways. © 2017 Wiley Periodicals, Inc.

  16. Calcium gluconate supplementation is effective to balance calcium homeostasis in patients with gastrectomy.

    Science.gov (United States)

    Krause, M; Keller, J; Beil, B; van Driel, I; Zustin, J; Barvencik, F; Schinke, T; Amling, M

    2015-03-01

    We demonstrate histological evidence for hyperparathyroidism in patients with gastrectomy. This is, at least in part, explained by impaired calcium absorption, resulting in mineralization defects and secondary hyperparathyroidism. Additionally, we demonstrate improved bone mineralization in patients with gastrectomy after gluconate therapy and showed the effectiveness of calcium gluconate over carbonate to balance impaired calcium hemostasis in mice. Gastrectomy and hypochlorhydria due to long-term proton pump inhibitor therapy are associated with increased fracture risk because of intestinal calcium malabsorption. Hence, our objectives were to histologically investigate bone metabolism in patients with gastrectomy and to analyze the impact of calcium gluconate supplementation on skeletal integrity in the setting of impaired gastric acidification. Undecalcified bone biopsies of 26 gastrectomized individuals were histologically analyzed. In the clinical setting, we retrospectively identified 5 gastrectomized patients with sufficient vitamin D level, who were additionally supplemented with calcium gluconate and had a real bone mineral density (aBMD) follow-up assessments. A mouse model of achlorhydria (ATP4b-/-) was used to compare the effect of calcium gluconate and calcium carbonate supplementation on bone metabolism. Biopsies from gastrectomized individuals showed significantly increased osteoid, osteoclast, and osteoblast indices and fibroosteoclasia (p < 0.05) as well as impaired calcium distribution in mineralized bone matrix compared to healthy controls. Five gastrectomized patients with sufficient vitamin D level demonstrated a significant increase in aBMD after a treatment with calcium gluconate alone for at least 6 months (p < 0.05). Calcium gluconate was superior to calcium carbonate in maintaining calcium metabolism in a mouse model of achlorhydria. Gastrectomy is associated with severe osteomalacia, marrow fibrosis, and impaired calcium distribution

  17. Influence of calcium sources on microbially induced calcium carbonate precipitation by Bacillus sp. CR2.

    Science.gov (United States)

    Achal, Varenyam; Pan, Xiangliang

    2014-05-01

    Stimulation of microbially induced calcium carbonate precipitation (MICCP) is likely to be influenced by calcium sources. In order to study such influences, we performed MICCP using Bacillus sp. CR2 in nutrient broth containing urea, supplemented with different calcium sources (calcium chloride, calcium oxide, calcium acetate and calcium nitrate). The experiment lasted 7 days, during which bacterial growth, urease activity, calcite production and pH were measured. Our results showed that calcium chloride is the better calcium source for MICCP process, since it provides higher urease activity and more calcite production. The influences of calcium sources on MICCP were further studied using Fourier transform-infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. These analyses confirmed that the precipitate formed was CaCO3 and composed of predominantly calcite crystals with a little amount of aragonite and vaterite crystals. The maximum yield of calcite precipitation was achievable with calcium chloride followed by calcium nitrate as a calcium source. The results of present study may be applicable to media preparation during efficient MICCP process.

  18. Calcium signals can freely cross the nuclear envelope in hippocampal neurons: somatic calcium increases generate nuclear calcium transients

    Directory of Open Access Journals (Sweden)

    Bading Hilmar

    2007-07-01

    Full Text Available Abstract Background In hippocampal neurons, nuclear calcium signaling is important for learning- and neuronal survival-associated gene expression. However, it is unknown whether calcium signals generated by neuronal activity at the cell membrane and propagated to the soma can unrestrictedly cross the nuclear envelope to invade the nucleus. The nuclear envelope, which allows ion transit via the nuclear pore complex, may represent a barrier for calcium and has been suggested to insulate the nucleus from activity-induced cytoplasmic calcium transients in some cell types. Results Using laser-assisted uncaging of caged calcium compounds in defined sub-cellular domains, we show here that the nuclear compartment border does not represent a barrier for calcium signals in hippocampal neurons. Although passive diffusion of molecules between the cytosol and the nucleoplasm may be modulated through changes in conformational state of the nuclear pore complex, we found no evidence for a gating mechanism for calcium movement across the nuclear border. Conclusion Thus, the nuclear envelope does not spatially restrict calcium transients to the somatic cytosol but allows calcium signals to freely enter the cell nucleus to trigger genomic events.

  19. Calcium signals can freely cross the nuclear envelope in hippocampal neurons: somatic calcium increases generate nuclear calcium transients

    Science.gov (United States)

    Eder, Anja; Bading, Hilmar

    2007-01-01

    Background In hippocampal neurons, nuclear calcium signaling is important for learning- and neuronal survival-associated gene expression. However, it is unknown whether calcium signals generated by neuronal activity at the cell membrane and propagated to the soma can unrestrictedly cross the nuclear envelope to invade the nucleus. The nuclear envelope, which allows ion transit via the nuclear pore complex, may represent a barrier for calcium and has been suggested to insulate the nucleus from activity-induced cytoplasmic calcium transients in some cell types. Results Using laser-assisted uncaging of caged calcium compounds in defined sub-cellular domains, we show here that the nuclear compartment border does not represent a barrier for calcium signals in hippocampal neurons. Although passive diffusion of molecules between the cytosol and the nucleoplasm may be modulated through changes in conformational state of the nuclear pore complex, we found no evidence for a gating mechanism for calcium movement across the nuclear border. Conclusion Thus, the nuclear envelope does not spatially restrict calcium transients to the somatic cytosol but allows calcium signals to freely enter the cell nucleus to trigger genomic events. PMID:17663775

  20. Induced calcium carbonate precipitation using Bacillus species.

    Science.gov (United States)

    Seifan, Mostafa; Samani, Ali Khajeh; Berenjian, Aydin

    2016-12-01

    Microbially induced calcium carbonate precipitation is an emerging process for the production of self-healing concrete. This study was aimed to investigate the effects and optimum conditions on calcium carbonate biosynthesis. Bacillus licheniformis, Bacillus sphaericus, yeast extract, urea, calcium chloride and aeration were found to be the most significant factors affecting the biomineralization of calcium carbonate. It was noticed that the morphology of microbial calcium carbonate was mainly affected by the genera of bacteria (cell surface properties), the viscosity of the media and the type of electron acceptors (Ca2+). The maximum calcium carbonate concentration of 33.78 g/L was achieved at the optimum conditions This value is the highest concentration reported in the literature.

  1. Calcium excretion in feces of ungulates.

    Science.gov (United States)

    Schryver, H F; Foose, T J; Williams, J; Hintz, H F

    1983-01-01

    1. Fecal excretion of calcium was examined in 122 individual ungulates representing 7 species of Equidae, 3 species of Tapiridae, 3 species of Rhinocerotidae, 2 species of Elephantidae, 2 species of Hippopotamidae, 12 species of Bovidae, 2 species of Cervidae, 3 species of Camellidae and 1 species of Giraffidae. 2. Animals were fed timothy hay, a low calcium diet or alfalfa hay, a high calcium diet. 3. In a few cases oat straw or prairie hay was used instead of timothy hay. 4. Samples of feces were obtained from individuals daily for 4 days following a 20 day dietary equilibration period. 5. Feces of equids, tapirs, rhinoceros and elephants had a lower calcium concentration and a lower Ca/P ratio than feces of ruminants when the animals were fed diets of equivalent calcium content. 6. The findings suggest that the non-ruminant ungulate equids, tapirs, rhinoceros and elephants absorb a larger proportion of dietary calcium than ruminants do.

  2. Binding of calcium and carbonate to polyacrylates.

    Science.gov (United States)

    Tribello, Gareth A; Liew, CheeChin; Parrinello, Michele

    2009-05-21

    Polyacrylate molecules can be used to slow the growth of calcium carbonate. However, little is known about the mechanism by which the molecules impede the growth rate. A recent computational study (Bulo et al. Macromolecules 2007, 40, 3437) used metadynamics to investigate the binding of calcium to polyacrylate chains and has thrown some light on the coiling and precipitation of these polymers. We extend these simulations to examine the binding of calcium and carbonate to polyacrylate chains. We show that calcium complexed with both carbonate and polyacrylate is a very stable species. The free energies of calcium-carbonate-polyacrylate complexes, with different polymer configurations, are calculated, and differences in the free energy of the binding of carbonate are shown to be due to differences in the amount of steric hindrance about the calcium, which prevents the approach of the carbonate ion.

  3. WAYS TO CORRECT CALCIUM DEFFICIT AMONG CHILDREN

    Directory of Open Access Journals (Sweden)

    N.I. Taibulatov

    2007-01-01

    Full Text Available The article is dedicated to the urgent issue of the pediatrics — calcium deficit among children. The authors provide modern data on the scheme of the normal calcium exchange in the human body. They also review the main diseases related to the disorders of the pho sphorocalcic metabolism, requiring prompt prevention and treatment by calcium based medications. The researchers stress the diseases of the musculoskeletal system, as insufficient calcium, phosphorus and vitamins supply of the child's body chiefly effects the state of the skeletal and muscular tissue. They give recommendations how to use the vitamin and mineral complex to correct calcium deficit.Key words: calcium deficit, diseases of the musculoskeletal system, vitamin and mineral complex, children.

  4. Altered calcium signaling in cancer cells.

    Science.gov (United States)

    Stewart, Teneale A; Yapa, Kunsala T D S; Monteith, Gregory R

    2015-10-01

    It is the nature of the calcium signal, as determined by the coordinated activity of a suite of calcium channels, pumps, exchangers and binding proteins that ultimately guides a cell's fate. Deregulation of the calcium signal is often deleterious and has been linked to each of the 'cancer hallmarks'. Despite this, we do not yet have a full understanding of the remodeling of the calcium signal associated with cancer. Such an understanding could aid in guiding the development of therapies specifically targeting altered calcium signaling in cancer cells during tumorigenic progression. Findings from some of the studies that have assessed the remodeling of the calcium signal associated with tumorigenesis and/or processes important in invasion and metastasis are presented in this review. The potential of new methodologies is also discussed. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Increasing Calcium Carbonate (Caco3) To Growt And Survival Rate Vannamei Shrimp (Litopenaeus Vannamei))

    OpenAIRE

    Heriadi, Unggul Fitrah; ', Mulyadi; Putra, Iskandar

    2016-01-01

    This research was conducted in March 2016 - April 2016 for 21 days at the NationalBroodstock Center For Shrimp and Mollusk Karangasem Bali. The purpose of this study todetermine the effect of calcium carbonate (CaCO3) on the growth and survival rate vanameishrimp (Litopeneaus vannamei). Vanamei shrimp size PL25 were used in the research. Thecontainer used fiber tub with capacity 250 liters and the volume of water used is 100 liters.The treatment is giving of calcium carbonate 20 mg, 35mg, 50m...

  6. Calcium dobesilate: pharmacology and future approaches.

    Science.gov (United States)

    Tejerina, T; Ruiz, E

    1998-09-01

    1. Calcium dobesilate (2,5-dihydroxybenzene sulfonate) is a drug commonly used in the treatment of diabetic retinopathy and chronic venous insufficiency. 2. The pharmacology of calcium dobesilate reveals its ability to decrease capillary permeability, as well as platelet aggregation and blood viscosity. 3. Furthermore, recent data show that calcium dobesilate increases endothelium-dependent relaxation owing to an increase in nitric oxide synthesis.

  7. Presynaptic calcium dynamics of learning neurons

    OpenAIRE

    Meyer-Hermann, Michael; Erler, Frido; Soff, Gerhard

    2002-01-01

    We present a new model for the dynamics of the presynaptic intracellular calcium concentration in neurons evoked by various stimulation protocols. The aim of the model is twofold: We want to discuss the calcium transients during and after specific stimulation protocols as they are used to induce long-term-depression and long-term-potentiation. In addition we would like to provide a general tool which allows the comparison of different calcium experiments. This may help to draw conclusions on ...

  8. Protein-Mediated Precipitation of Calcium Carbonate

    OpenAIRE

    Izabela Polowczyk; Anna Bastrzyk; Marta Fiedot

    2016-01-01

    Calcium carbonate is an important component in exoskeletons of many organisms. The synthesis of calcium carbonate was performed by mixing dimethyl carbonate and an aqueous solution of calcium chloride dihydrate. The precipitation product was characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) measurements. In addition, the turbidity of the reaction solution was acquire...

  9. Hypercalcemia Associated with Calcium Supplement Use: Prevalence and Characteristics in Hospitalized Patients

    Directory of Open Access Journals (Sweden)

    Maria C. Machado

    2015-03-01

    Full Text Available Background: The ingestion of large amounts of milk and antacids to treat peptic ulcer disease was a common cause of hypercalcemia in the past (the “milk-alkali syndrome”. The current popularity of calcium and supplements has given rise to a similar problem. Objectives: To evaluate the prevalence and characteristics of hypercalcemia induced by calcium intake (“calcium supplement syndrome”; or CSS in hospitalized patients. Methods: We conducted a retrospective; electronic health record (EHR-based review of patients with hypercalcemia over a 3-year period. Diagnosis of CSS was based on the presence of hypercalcemia; a normal parathyroid hormone (PTH level; renal insufficiency; metabolic alkalosis; a history of calcium intake; and documented improvement with treatment. Results: Of the 72 patients with non-PTH mediated hypercalcemia; 15 (20.8% satisfied all the criteria for the diagnosis of CSS. Calcium; vitamin D; and multivitamin ingestion were significantly associated with the diagnosis (p values < 0.0001; 0.014; and 0.045 respectively; while the presence of hypertension; diabetes; and renal insufficiency showed a trend towards statistical significance. All patients received intravenous fluids; and six (40% received calcium-lowering drugs. The calcium level at discharge was normal 12 (80% of patients. The mean serum creatinine and bicarbonate levels decreased from 2.4 and 35 mg/dL on admission respectively; to 1.6 mg/dL and 25.6 mg/dL at discharge respectively. Conclusion: The widespread use of calcium and vitamin D supplementation can manifest as hypercalcemia and worsening of kidney function in susceptible individuals. Awareness among health care professionals can lead to proper patient education regarding these health risks.

  10. Mechanical Properties of a Calcium Dietary Supplement, Calcium Fumarate Trihydrate.

    Science.gov (United States)

    Sun, Shijing; Henke, Sebastian; Wharmby, Michael T; Yeung, Hamish H-M; Li, Wei; Cheetham, Anthony K

    2015-12-07

    The mechanical properties of calcium fumarate trihydrate, a 1D coordination polymer considered for use as a calcium source for food and beverage enrichment, have been determined via nanoindentation and high-pressure X-ray diffraction with single crystals. The nanoindentation studies reveal that the elastic modulus (16.7-33.4 GPa, depending on crystallographic orientation), hardness (1.05-1.36 GPa), yield stress (0.70-0.90 GPa), and creep behavior (0.8-5.8 nm/s) can be rationalized in view of the anisotropic crystal structure; factors include the directionality of the inorganic Ca-O-Ca chain and hydrogen bonding, as well as the orientation of the fumarate ligands. High-pressure single-crystal X-ray diffraction studies show a bulk modulus of ∼ 20 GPa, which is indicative of elastic recovery intermediate between small molecule drug crystals and inorganic pharmaceutical ingredients. The combined use of nanoindentation and high-pressure X-ray diffraction techniques provides a complementary experimental approach for probing the critical mechanical properties related to tableting of these dietary supplements.

  11. Calcium dependence of inactivation of calcium release from the sarcoplasmic reticulum in skeletal muscle fibers.

    Science.gov (United States)

    Simon, B J; Klein, M G; Schneider, M F

    1991-03-01

    The steady-state calcium dependence of inactivation of calcium release from the sarcoplasmic reticulum was studied in voltage-clamped, cut segments of frog skeletal muscle fibers containing two calcium indicators, fura-2 and anti-pyrylazo III (AP III). Fura-2 fluorescence was used to monitor resting calcium and relatively small calcium transients during small depolarizations. AP III absorbance signals were used to monitor larger calcium transients during larger depolarizations. The rate of release (Rrel) of calcium from the sarcoplasmic reticulum was calculated from the calcium transients. The equilibrium calcium dependence of inactivation of calcium release was determined using 200-ms prepulses of various amplitudes to elevate [Ca2+] to various steady levels. Each prepulse was followed by a constant test pulse. The suppression of peak Rrel during the test pulse provided a measure of the extent of inactivation of release at the end of the prepulse. The [Ca2+] dependence of inactivation indicated that binding of more than one calcium ion was required to inactivate each release channel. Half-maximal inactivation was produced at a [Ca2+] of approximately 0.3 microM. Variation of the prepulse duration and amplitude showed that the suppression of peak release was consistent with calcium-dependent inactivation of calcium release but not with calcium depletion. The same calcium dependence of inactivation was obtained using different amplitude test pulses to determine the degree of inactivation. Prepulses that produced near maximal inactivation of release during the following test pulse produced no suppression of intramembrane charge movement during the test pulse, indicating that inactivation occurred at a step beyond the voltage sensor for calcium release. Three alternative set of properties that were assumed for the rapidly equilibrating calcium-binding sites intrinsic to the fibers gave somewhat different Rrel records, but gave very similar calcium dependence of

  12. Protein-Mediated Precipitation of Calcium Carbonate.

    Science.gov (United States)

    Polowczyk, Izabela; Bastrzyk, Anna; Fiedot, Marta

    2016-11-22

    Calcium carbonate is an important component in exoskeletons of many organisms. The synthesis of calcium carbonate was performed by mixing dimethyl carbonate and an aqueous solution of calcium chloride dihydrate. The precipitation product was characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) measurements. In addition, the turbidity of the reaction solution was acquired to monitor the kinetics of the calcium carbonate structure's growth in the investigated system. In this study, samples of CaCO₃ particles obtained with individual proteins, such as ovalbumin, lysozyme, and a mixture of the proteins, were characterized and compared with a control sample, i.e., synthesized without proteins. The obtained data indicated that the addition of ovalbumin to the reaction changed the morphology of crystals from rhombohedral to 'stack-like' structures. Lysozyme, however, did not affect the morphology of calcium carbonate, yet the presence of the protein mixture led to the creation of more complex composites in which the calcium carbonate crystals were constructed in protein matrices formed by the ovalbumin-lysozyme interaction. It was also observed that in the protein mixture, ovalbumin has a major influence on the CaCO₃ formation through a strong interaction with calcium ions, which leads to the coalescence and creation of a steric barrier reducing particle growth. The authors proposed a mechanism of calcium carbonate grain growth in the presence of both proteins, taking into account the interaction of calcium ions with the protein.

  13. Diuretics and disorders of calcium homeostasis.

    Science.gov (United States)

    Grieff, Marvin; Bushinsky, David A

    2011-11-01

    Diuretics commonly are administered in disorders of sodium balance. Loop diuretics inhibit the Na-K-2Cl transporter and also increase calcium excretion. They are often used in the treatment of hypercalcemia. Thiazide diuretics block the thiazide-sensitive NaCl transporter in the distal convoluted tubule, and can decrease calcium excretion. They are often used in the treatment of nephrolithiasis. Carbonic anhydrase inhibitors decrease bicarbonate absorption and the resultant metabolic acidosis can increase calcium excretion. Their use can promote nephrocalcinosis and nephrolithiasis. This review will address the use of diuretics on disorders of calcium homeostasis. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. [ZINK IS ACTIVATOR OF ENTERAL CALCIUM METABOLISM].

    Science.gov (United States)

    Polyakova, E P; Ksenofontov, D A; Revyakin, A O; Ivanov, A A

    2015-01-01

    Experiments on goats and rabbits showed that zinc supplement to the diet leads to calcium concentration rise in muscle, bone and blood of animals. However, this rise was not adequate to increase in.zinc consumption. The bulk of alimentary zinc stayed in soluble fraction, dense endogen fraction and infusoria fraction of digesta and stimulated calcium release from food particles, it's accumulation in digesta fractions and calcium utilization on the whole. Authors estimate animal digesta as homeostatic, spatial organized, endogenic formation in which zinc and calcium are functionally dependent through enteral mucosa.

  15. The Electronic Structure of Calcium

    DEFF Research Database (Denmark)

    Jan, J.-P.; Skriver, Hans Lomholt

    1981-01-01

    .149 Ryd, respectively, relative to the s band, give the best possible agreement. Under increasing pressure the s and p electrons are found to transfer into the d band, and Ca undergoes metal-semimetal-metal electronic transitions. Calculations of the bandstructure and the electronic pressure, including......The electronic structure of calcium under pressure is re-examined by means of self-consistent energy band calculations based on the local density approximation and using the linear muffin-tin orbitals (LMTO) method with corrections to the atomic sphere approximation included. At zero pressure...

  16. 50 CFR 35.8 - Forest management.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Forest management. 35.8 Section 35.8... NATIONAL WILDLIFE REFUGE SYSTEM WILDERNESS PRESERVATION AND MANAGEMENT General Rules § 35.8 Forest management. Forest management activities in a wilderness unit will be directed toward allowing natural...

  17. 40 CFR 35.9065 - Limitations.

    Science.gov (United States)

    2010-07-01

    ... cost share of the aggregate costs of research, surveys, studies, modeling, and other technical work... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Limitations. 35.9065 Section 35.9065... ASSISTANCE Financial Assistance for the National Estuary Program § 35.9065 Limitations. (a) Management...

  18. 40 CFR 35.935-3 - Property.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Property. 35.935-3 Section 35.935-3... ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.935-3 Property. (a) The grantee must comply with the property provisions of § 30.810 et seq. of this subchapter with respect to all...

  19. 40 CFR 35.937-5 - Negotiation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Negotiation. 35.937-5 Section 35.937-5... ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.937-5 Negotiation. (a) Grantees are responsible for negotiation of their contracts for architectural or engineering services. Contract...

  20. 40 CFR 35.6405 - Use.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Use. 35.6405 Section 35.6405 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL... Requirements Under A Cooperative Agreement § 35.6405 Use. The recipient must comply with the requirements...

  1. 50 CFR 35.6 - Public use.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Public use. 35.6 Section 35.6 Wildlife and... WILDLIFE REFUGE SYSTEM WILDERNESS PRESERVATION AND MANAGEMENT General Rules § 35.6 Public use. Public uses... wildlife refuge was established and is administered and laws and regulations governing public uses within...

  2. 32 CFR 3.5 - Appropriate use.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Appropriate use. 3.5 Section 3.5 National... CONTRACTS, GRANTS, OR COOPERATIVE AGREEMENTS FOR PROTOTYPE PROJECTS § 3.5 Appropriate use. In accordance... Executive for the agency determines in writing that exceptional circumstances justify the use of a...

  3. 40 CFR 35.9020 - Planning targets.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Planning targets. 35.9020 Section 35... STATE AND LOCAL ASSISTANCE Financial Assistance for the National Estuary Program § 35.9020 Planning targets. The EPA Assistant Administrator for Water develops planning targets each year to help each...

  4. 45 CFR 5.35 - Time limits.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Time limits. 5.35 Section 5.35 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION FREEDOM OF INFORMATION REGULATIONS Release and Denial of Records § 5.35 Time limits. (a) General. FOIA sets certain time limits for us to decide whether...

  5. 40 CFR 35.682 - Definition.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Definition. 35.682 Section 35.682... ASSISTANCE Environmental Program Grants for Tribes Underground Water Source Protection (section 1443(b)) § 35.682 Definition. Tribe. Any Indian Tribe having a federally recognized governing body carrying out...

  6. 21 CFR 203.35 - Standing requests.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Standing requests. 203.35 Section 203.35 Food and... PRESCRIPTION DRUG MARKETING Samples § 203.35 Standing requests. Manufacturers or authorized distributors of record shall not distribute drug samples on the basis of open-ended or standing requests, but shall...

  7. 40 CFR 35.936-1 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.936-1 Definitions. As used in §§ 35.936 through 35.939, the following words and terms shall have the meaning set forth below. All...

  8. 32 CFR 701.35 - Reading room.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Reading room. 701.35 Section 701.35 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY REGULATIONS AND... DOCUMENTS AFFECTING THE PUBLIC FOIA Definitions and Terms § 701.35 Reading room. Location where (a)(2...

  9. 40 CFR 35.161 - Definition.

    Science.gov (United States)

    2010-07-01

    ... ASSISTANCE Environmental Program Grants Water Pollution Control (section 106) § 35.161 Definition. Recurrent expenditures are those expenditures associated with the activities of a continuing Water Pollution Control... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Definition. 35.161 Section 35.161...

  10. 28 CFR 35.178 - State immunity.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false State immunity. 35.178 Section 35.178 Judicial Administration DEPARTMENT OF JUSTICE NONDISCRIMINATION ON THE BASIS OF DISABILITY IN STATE AND LOCAL GOVERNMENT SERVICES Compliance Procedures § 35.178 State immunity. A State shall not be immune...

  11. 49 CFR 605.35 - Judicial review.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Judicial review. 605.35 Section 605.35..., DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS Complaint Procedures and Remedies § 605.35 Judicial review... parties, but shall be subject to judicial review pursuant to title 5 U.S.C. 701-706. ...

  12. 50 CFR 35.12 - Water rights.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Water rights. 35.12 Section 35.12 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM WILDERNESS PRESERVATION AND MANAGEMENT General Rules § 35.12 Water rights... the Department of the Interior as to exemption from State water laws. ...

  13. 48 CFR 35.012 - Patent rights.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Patent rights. 35.012 Section 35.012 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 35.012 Patent rights. For a discussion of patent rights, see...

  14. 48 CFR 35.011 - Data.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Data. 35.011 Section 35... CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 35.011 Data. (a) R&D contracts shall specify the technical data to be delivered under the contract, since the data clauses required by part 27 do not require the...

  15. 40 CFR 35.6290 - Program income.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Program income. 35.6290 Section 35.6290... Administration Requirements Under A Cooperative Agreement § 35.6290 Program income. The recipient must comply with the requirements regarding program income described in 40 CFR 31.25. Recoveries of Federal cost...

  16. 28 CFR 35.132 - Smoking.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Smoking. 35.132 Section 35.132 Judicial... SERVICES General Requirements § 35.132 Smoking. This part does not preclude the prohibition of, or the imposition of restrictions on, smoking in transportation covered by this part. ...

  17. 40 CFR 35.2218 - Project performance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Project performance. 35.2218 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2218 Project performance. (a... personnel; and (3) Advise the grantee whether the project is meeting the project performance standards. (c...

  18. 24 CFR 35.315 - Risk assessment.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Risk assessment. 35.315 Section 35... Provided by a Federal Agency Other Than HUD § 35.315 Risk assessment. Each owner shall complete a risk assessment in accordance with 40 CFR 745.227(d). Each risk assessment shall be completed in accordance with...

  19. 14 CFR 35.36 - Bird impact.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird impact. 35.36 Section 35.36... STANDARDS: PROPELLERS Tests and Inspections § 35.36 Bird impact. The applicant must demonstrate, by tests or... 4-pound bird at the critical location(s) and critical flight condition(s) of a typical installation...

  20. 40 CFR 35.2114 - Value engineering.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Value engineering. 35.2114 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2114 Value engineering. (a) If the project has not received Step 2 grant assistance the applicant shall conduct value engineering...

  1. 50 CFR 35.11 - Scientific uses.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Scientific uses. 35.11 Section 35.11... NATIONAL WILDLIFE REFUGE SYSTEM WILDERNESS PRESERVATION AND MANAGEMENT General Rules § 35.11 Scientific uses. Recognizing the scientific value of wilderness, research data gathering and similar scientific...

  2. 7 CFR 35.1 - Act.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Act. 35.1 Section 35.1 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices... Definitions § 35.1 Act. Act or Export Grape and Plum Act means “An Act to promote the foreign trade of the...

  3. 42 CFR 35.41 - Inventory.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Inventory. 35.41 Section 35.41 Public Health PUBLIC... STATION MANAGEMENT Disposal of Money and Effects of Deceased Patients § 35.41 Inventory. Promptly after the death of a patient in a station or hospital of the Service, an inventory of his money and effects...

  4. 24 CFR 1007.35 - Loan terms.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Loan terms. 1007.35 Section 1007.35... LOAN GUARANTEES FOR NATIVE HAWAIIAN HOUSING § 1007.35 Loan terms. To be eligible for guarantee under this part, the loan shall: (a) Be made for a term not exceeding 30 years; (b) Bear interest (exclusive...

  5. 40 CFR 73.35 - Compliance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Compliance. 73.35 Section 73.35... ALLOWANCE SYSTEM Allowance Tracking System § 73.35 Compliance. (a) Allowance transfer deadline. No allowance shall be deducted for purposes of compliance with an affected source's sulfur dioxide Acid Rain...

  6. 40 CFR 35.2113 - Environmental review.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Environmental review. 35.2113 Section 35.2113 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2113 Environmental review. (a...

  7. 14 CFR 77.35 - Aeronautical studies.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical studies. 77.35 Section 77.35 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRSPACE OBJECTS AFFECTING NAVIGABLE AIRSPACE Aeronautical Studies of Effect of Proposed Construction on Navigable Airspace § 77.35 Aeronautical studies. ...

  8. 36 CFR 222.35 - Studies.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Studies. 222.35 Section 222.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE RANGE MANAGEMENT Management of Wild Free-Roaming Horses and Burros § 222.35 Studies. The Chief, Forest Service, is authorized and directed to undertake those studies of...

  9. 40 CFR 35.2101 - Advanced treatment.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Advanced treatment. 35.2101 Section 35... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2101 Advanced treatment. Projects proposing advanced treatment shall be awarded grant assistance only after the project has been...

  10. 14 CFR 35.39 - Endurance test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Endurance test. 35.39 Section 35.39... STANDARDS: PROPELLERS Tests and Inspections § 35.39 Endurance test. Endurance tests on the propeller system... propellers must be subjected to one of the following tests: (1) A 50-hour flight test in level flight or in...

  11. 14 CFR 35.40 - Functional test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Functional test. 35.40 Section 35.40... STANDARDS: PROPELLERS Tests and Inspections § 35.40 Functional test. The variable-pitch propeller system must be subjected to the applicable functional tests of this section. The same propeller system used in...

  12. 14 CFR 35.15 - Safety analysis.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Safety analysis. 35.15 Section 35.15... STANDARDS: PROPELLERS Design and Construction § 35.15 Safety analysis. (a)(1) The applicant must analyze the.... This analysis will take into account, if applicable: (i) The propeller system in a typical installation...

  13. 46 CFR 58.30-35 - Testing.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Testing. 58.30-35 Section 58.30-35 Shipping COAST GUARD... SYSTEMS Fluid Power and Control Systems § 58.30-35 Testing. (a) All fluid power and control systems and... fluid and all trapped air bled from the system prior to any shipboard testing. In no case shall air...

  14. 7 CFR 953.35 - Accounting.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Accounting. 953.35 Section 953.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... STATES Order Regulating Handling Expenses and Assessments § 953.35 Accounting. (a) If, at the end of a...

  15. 7 CFR 906.35 - Accounting.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Accounting. 906.35 Section 906.35 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Expenses and Assessments § 906.35 Accounting. (a...

  16. 40 CFR 35.382 - Competitive process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive process. 35.382 Section 35.382 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...)(3)) § 35.382 Competitive process. State Wetlands Development Grants are awarded on a competitive...

  17. 40 CFR 35.613 - Competitive process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive process. 35.613 Section 35.613 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... (section 104(b)(3)) § 35.613 Competitive process. Wetlands development grants are awarded on a competitive...

  18. 40 CFR 35.661 - Competitive process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive process. 35.661 Section 35.661 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... 6605) § 35.661 Competitive process. EPA Regions award Pollution Prevention Grant funds to Tribes and...

  19. 40 CFR 35.603 - Competitive process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive process. 35.603 Section 35.603 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... (section 104(b)(3)) § 35.603 Competitive process. EPA will award water quality cooperative agreement funds...

  20. 40 CFR 35.723 - Competitive process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive process. 35.723 Section 35.723 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Grants (pub.l. 105-276) § 35.723 Competitive process. EPA will award Tribal hazardous waste program...

  1. 40 CFR 35.712 - Competitive process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive process. 35.712 Section 35.712 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Monitoring (section 28) § 35.712 Competitive process. EPA will award Toxic Substances Control Act Compliance...

  2. 40 CFR 35.362 - Competitive process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive process. 35.362 Section 35.362 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... 104(b)(3)) § 35.362 Competitive process. EPA will award Water Quality Cooperative Agreement funds...

  3. 40 CFR 35.342 - Competitive process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive process. 35.342 Section 35.342 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...) § 35.342 Competitive process. EPA Regions award Pollution Prevention State Grants to State programs...

  4. 24 CFR 35.815 - Evaluation.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Evaluation. 35.815 Section 35.815 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD... Multifamily Property § 35.815 Evaluation. HUD shall conduct a risk assessment and a lead-based paint...

  5. 10 CFR § 1003.35 - Contents.

    Science.gov (United States)

    2017-01-01

    ... 10 Energy 4 2017-01-01 2017-01-01 false Contents. § 1003.35 Section § 1003.35 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) OFFICE OF HEARINGS AND APPEALS PROCEDURAL REGULATIONS Appeals § 1003.35 Contents. (a) The appeal shall contain a concise statement of grounds upon which it is brought and...

  6. IL-35 and Autoimmunity: a Comprehensive Perspective.

    Science.gov (United States)

    Choi, Jinjung; Leung, Patrick S C; Bowlus, Christopher; Gershwin, M Eric

    2015-12-01

    Interleukin 35 (IL-35) is the most recently identified member of the IL-12 family of cytokines and offers the potential to be a target for new therapies for autoimmune, inflammatory, and infectious diseases. Similar to other members of the IL-12 family including IL-12, IL-23, and IL-27, IL-35 is composed of a heterodimer of α and β chains, which in the case of IL-35 are the p35 and Epstein-Barr virus-induced gene 3 (EBI3) proteins. However, unlike its proinflammatory relatives, IL-35 has immunosuppressive effects that are mediated through regulatory T and B cells. Although there are limited data available regarding the role of IL-35 in human autoimmunity, several murine models of autoimmunity suggest that IL-35 may have potent effects in regulating immunoreactivity via IL-10-dependent mechanisms. We suggest that similar effects are operational in human disease and IL-35-directed therapies hold significant promise. In particular, we emphasize that IL-35 has immunosuppressive ability that are mediated via regulatory T and B cells that are IL-10 dependent. Further, although deletion of IL-35 does not result in spontaneous breach of tolerance, recombinant IL-35 can improve autoimmune responses in several experimental models.

  7. 24 CFR 7.35 - Processing.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Processing. 7.35 Section 7.35 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development EQUAL..., Color Religion, Sex, National Origin, Age, Disability or Reprisal Complaints § 7.35 Processing. (a) The...

  8. 7 CFR 29.35 - Lot seal.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots of...

  9. 40 CFR 35.117 - Unused funds.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Unused funds. 35.117 Section 35.117 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants Post-Award Requirements § 35.117 Unused funds. If funds for an...

  10. 40 CFR 35.517 - Unused funds.

    Science.gov (United States)

    2010-07-01

    ... ASSISTANCE Environmental Program Grants for Tribes Post-Award Requirements § 35.517 Unused funds. If funds... has already received funds) for the same environmental program or for a Performance Partnership Grant... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Unused funds. 35.517 Section 35.517...

  11. 14 CFR 21.35 - Flight tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight tests. 21.35 Section 21.35... PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.35 Flight tests. (a) Each applicant for an aircraft...) That the aircraft conforms with the type design; and (4) That the Administrator received a flight test...

  12. Short communication: Urinary oxalate and calcium excretion by dogs and cats diagnosed with calcium oxalate urolithiasis

    NARCIS (Netherlands)

    Dijcker, J.C.; Kummeling, A.; Hagen-Plantinga, E.A.; Hendriks, W.H.

    2012-01-01

    Introduction Urine concentrations of oxalate and calcium play an important role in calcium oxalate (CaOx) urolith formation in dogs and cats, with high excretions of both substances increasing the chance of CaOx urolithiasis. In 17 CaOx-forming dogs, urine calcium:creatinine ratio (Ca:Cr) was found

  13. Impaired body calcium metabolism with low bone density and compensatory colonic calcium absorption in cecectomized rats

    NARCIS (Netherlands)

    Jongwattanapisan, P.; Suntornsaratoon, P.; Wongdee, K.; Dorkkam, N.; Krishnamra, N.; Charoenphandhu, N.

    2012-01-01

    An earlier study reported that cecal calcium absorption contributes less than 10% of total calcium absorbed by the intestine, although the cecum has the highest calcium transport rate compared with other intestinal segments. Thus, the physiological significance of the cecum pertaining to body

  14. Plasma membrane calcium pump and sodium-calcium exchanger in maintenance and control of calcium concentrations in platelets.

    Science.gov (United States)

    Juska, Alfonsas

    2010-01-29

    The purpose of this research was to elucidate the activity of the mechanisms responsible for control of cytosolic calcium concentration in platelets by modeling the time-course of the concentration changing in response to discharge of the intracellular stores or store-operated calcium entry (SOCE). The parameters estimated as a result of model fitting to experimental data are related to physiological or pathological state of the cells. It has been shown that: (a) the time-course is determined by the passive calcium fluxes and activities of the corresponding mechanisms; (b) the decline in the concentration (after its rise) develops due to activity of plasma membrane calcium ATPase (PMCA) both in the case of discharge of the stores of platelets contained in calcium-free medium and in the case of SOCE; (c) impulsive extrusion of calcium in response to its sudden influx, presumably, is the main function of PMCA; (d) the function of sodium-calcium exchanger (NCX) is to extrude calcium excess by permanent counteracting its influx. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  15. Pseudogout and Calcium Pyrophosphate Disease

    Directory of Open Access Journals (Sweden)

    Andrew Williamson

    2017-01-01

    Full Text Available History of present illness: A 53-year-old male presented with worsening right knee pain and swelling over the past 48 hours. He denied recent trauma to the knee, history of IV drug use, and recent illness. He had no history of diabetes, immunodeficiency, chronic steroids, rheumatologic disease, or knee replacement. He described the pain as sharp, non-radiating, and worse with movement. He was unable to walk due to pain. Significant findings: Radiographs of the knee showed multiple radio-dense lines paralleling the articular surface (see red arrows consistent with calcium pyrophosphate crystal deposition within the joint often seen in calcium pyrophosphate disease (CPPD also known as pseudogout. Discussion: Patients commonly present to the emergency department with non-traumatic joint pain. Arthrocentesis is an important diagnostic tool to evaluate for septic arthritis, gout, or pseudogout. Arthrocentesis can demonstrate crystals or abnormal cell count, gram stain, and culture.[1] In the evaluation of joint pain, plain films are usually obtained to evaluate for fracture, dislocation, effusion, or secondary signs of infection. In this case the classic x-ray supported the diagnosis of CPPD.2 The patient was found to have positively birefringent rhomboid shaped crystals consistent with pseudogout on arthrocentesis. Gram stain and culture were both negative. The patient was discharged with NSAIDs and had significant improvement in symptoms upon follow up with primary care physician in 3 days.

  16. Paclitaxel induces apoptosis in breast cancer cells through different calcium--regulating mechanisms depending on external calcium conditions.

    Science.gov (United States)

    Pan, Zhi; Avila, Andrew; Gollahon, Lauren

    2014-02-17

    Previously, we reported that endoplasmic reticulum calcium stores were a direct target for paclitaxel initiation of apoptosis. Furthermore, the actions of paclitaxel attenuated Bcl-2 resistance to apoptosis through endoplasmic reticulum-mediated calcium release. To better understand the calcium-regulated mechanisms of paclitaxel-induced apoptosis in breast cancer cells, we investigated the role of extracellular calcium, specifically; whether influx of extracellular calcium contributed to and/or was necessary for paclitaxel-induced apoptosis. Our results demonstrated that paclitaxel induced extracellular calcium influx. This mobilization of extracellular calcium contributed to subsequent cytosolic calcium elevation differently, depending on dosage. Under normal extracellular calcium conditions, high dose paclitaxel induced apoptosis-promoting calcium influx, which did not occur in calcium-free conditions. In the absence of extracellular calcium an "Enhanced Calcium Efflux" mechanism in which high dose paclitaxel stimulated calcium efflux immediately, leading to dramatic cytosolic calcium decrease, was observed. In the absence of extracellular calcium, high dose paclitaxel's stimulatory effects on capacitative calcium entry and apoptosis could not be completely restored. Thus, normal extracellular calcium concentrations are critical for high dose paclitaxel-induced apoptosis. In contrast, low dose paclitaxel mirrored controls, indicating that it occurs independent of extracellular calcium. Thus, extracellular calcium conditions only affect efficacy of high dose paclitaxel-induced apoptosis.

  17. Spatiotemporal intracellular calcium dynamics during cardiac alternans

    Science.gov (United States)

    Restrepo, Juan G.; Karma, Alain

    2009-09-01

    Cellular calcium transient alternans are beat-to-beat alternations in the peak cytosolic calcium concentration exhibited by cardiac cells during rapid electrical stimulation or under pathological conditions. Calcium transient alternans promote action potential duration alternans, which have been linked to the onset of life-threatening ventricular arrhythmias. Here we use a recently developed physiologically detailed mathematical model of ventricular myocytes to investigate both stochastic and deterministic aspects of intracellular calcium dynamics during alternans. The model combines a spatially distributed description of intracellular calcium cycling, where a large number of calcium release units are spatially distributed throughout the cell, with a full set of ionic membrane currents. The results demonstrate that ion channel stochasticity at the level of single calcium release units can influence the whole-cell alternans dynamics by causing phase reversals over many beats during fixed frequency pacing close to the alternans bifurcation. They also demonstrate the existence of a wide range of dynamical states. Depending on the sign and magnitude of calcium-voltage coupling, calcium alternans can be spatially synchronized or desynchronized, in or out of phase with action potential duration alternans, and the node separating out-of-phase regions of calcium alternans can be expelled from or trapped inside the cell. This range of states is found to be larger than previously anticipated by including a robust global attractor where calcium alternans can be spatially synchronized but out of phase with action potential duration alternans. The results are explained by a combined theoretical analysis of alternans stability and node motion using general iterative maps of the beat-to-beat dynamics and amplitude equations.

  18. Cloning, purification, crystallization and preliminary crystallographic study of calcium-binding protein 5 from Entamoeba histolytica.

    Science.gov (United States)

    Kumar, Sanjeev; Zaidi, Rana; Gourinath, Samudrala

    2012-12-01

    Entamoeba histolytica is the causative agent of human amoebiasis. Phagocytosis is the major route of food intake by this parasite and is responsible for its virulence. Calcium and calcium-binding proteins play major roles in its phagocytosis. Calcium-binding protein 5 from E. histolytica (EhCaBP5) is a cytoplasmic protein; its expression is very sensitive to serum starvation and it seems to be involved in binding to myosin I. In this study, EhCaBP5 was cloned, expressed in Escherichia coli and purified using affinity and size-exclusion chromatography. The purified protein crystallized in space group C222 and the crystals diffracted to 2 Å resolution. The Matthews coefficient indicated the presence of one molecule in the asymmetric unit, with a VM of 2.35 Å3 Da(-1) and a solvent content of 47.7%.

  19. Calcium pyrophosphate dihydrate deposition disease (CPPD/Pseudogout of the temporomandibular joint - FNA findings and microanalysis.

    Directory of Open Access Journals (Sweden)

    Naqvi Asghar

    2008-01-01

    Full Text Available We report a case of a Calcium pyrophosphate dihydrate deposition disease (CPPD presenting as a mass in the parotid and temporomandibular joint (TMJ that simulated a parotid tumor. A 35 year-old man presented with pain in the left ear area. A CT Scan of the area showed a large, calcified mass surrounding the left condylar head, and extending into the infratemporal fossa. FNA of the mass showed birefringent crystals, most of which were rhomboid with occasional ones being needle shaped, embedded in an amorphous pink substance. Scanning electron microscopy (SEM with energy dispersive x-ray spectroscopy (EDS of these crystals showed peaks corresponding to calcium and phosphorus. SEM/EDS is a rapid method of diagnosing calcium pyrophosphate dihydrate deposition disease (CPPD and an alternative to more commonly used method of special staining of cell block sections coupled with polarizing microscopy.

  20. Calcium Blood Test: MedlinePlus Lab Test Information

    Science.gov (United States)

    ... this page: https://medlineplus.gov/labtests/calciumbloodtest.html Calcium Blood Test To use the sharing features on this page, please enable JavaScript. What is a Calcium Blood Test? A calcium blood test measures the ...

  1. Rates of calcium carbonate removal from soils.

    NARCIS (Netherlands)

    Breemen, van N.; Protz, R.

    1988-01-01

    Mean annual rates of calcium carbonate removal from soils in a subarctic climate estimated from data on two chronosequences of calcareous storm ridges, appeared to be relatively constant through time. Concentrations of dissolved calcium carbonate in the soil solution in the study sites calculated

  2. Calcium and M'yocardial Infarction

    African Journals Online (AJOL)

    1974-03-16

    Mar 16, 1974 ... Urinary excretion of calcium tended to be even lower in these .... 16 March 1974. S.A. MEDICAL JOURNAL. 525. 150. 50. Fig. 5. Urine calcium in myocardial infarction (means and standard error relative to age). AGE OF PATIENT .... Plasma proteins and blood urea were also measured in. 10 consecutive ...

  3. Calcium, snails, and birds: a case study

    Directory of Open Access Journals (Sweden)

    R. Mänd

    2000-10-01

    Full Text Available Recent studies have shown that wild birds breeding in acidified areas have difficulties with obtaining sufficient calcium for their eggshells, and that the cause of it is the shortage of land snails. Many birds have to search for Ca-rich snail shells on a daily basis during egg production. Molluscs depend on litter calcium, which has decreased due to acidification of the environment. Calcium limitation may be a widespread phenomenon also in non-acidified, naturally Ca-poor areas. The problem is that while in the latter areas the time for development of specific adaptations may have been sufficient, then in acidified areas, on the contrary, calcium shortage is a recent phenomenon. Therefore, since the extent of calcium limitation in non-acidified areas is hard to derive from observational data, experimental approach is needed. We provide experimental evidence that specific calcium deficit does affect reproductive traits also in the birds breeding in naturally base-poor habitats. Our study was conducted in a heterogeneous woodland area in Estonia containing deciduous forest patches as well as base-poor pine forest with low snail abundance. Ca supplementation, using snail shell and chicken eggshell fragments, was carried out for pied flycatchers and great tits. Extra calcium affected positively several reproductive traits like egg volume and eggshell thickness, start of breeding, and fledglings’ parameters. The negative relationship between calcium availability and lay-date suggests that birds adjust their breeding tactics to conditions of Ca deficiency, for example, by postponing laying.

  4. 21 CFR 182.8223 - Calcium pyrophosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium pyrophosphate. 182.8223 Section 182.8223 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8223 Calcium...

  5. 21 CFR 182.8217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium phosphate. 182.8217 Section 182.8217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8217 Calcium...

  6. Elements from chlorine to calcium nuclear reactions

    CERN Document Server

    Kunz, Wunibald

    1968-01-01

    Nuclear Tables: Part II Nuclear Reactions, Volume 3: The Elements from Chlorine to Calcium contains tabulations of the nuclear reaction values of elements chlorine, argon, potassium, and calcium. These tabulations provide the calculated Q-values of the elements and their isotopes. This book will be of value to general chemistry researchers.

  7. Role of calcium in selenium cataract.

    Science.gov (United States)

    Shearer, T R; David, L L

    The purpose of this research was to test the role of certain minerals in the formation of cataract caused by an overdose of selenium. Several pieces of information indicated that lenticular calcium may play an important role in selenite cataractogenesis: 1) Lens calcium concentrations in selenite treated rats were increased more than 5-fold, and the increase in lens calcium was localized in the nucleus. 2) Lens calcium concentrations were elevated at least one full day before actual formation of nuclear cataract, but serum calcium levels were not changed. 3) In older rats not susceptible to selenite cataract, lens calcium was not significantly increased. 4) No evidence was found for a generalized disruption in lens permeability, since no major changes in lens water, sodium, and potassium levels were observed, and 5) when levels of calcium observed in selenite cataract were added to solutions of soluble proteins from rat lenses, light scattering was increased. Selenium-overdose cataracts may provide an important model for studies on the role of calcium in cataractogenesis.

  8. Adding calcium improves lithium ferrite core

    Science.gov (United States)

    Lessoff, H.

    1969-01-01

    Adding calcium increases uniformity of grain growth over a wide range of sintering temperatures and reduces porosity within the grain. Ferrite cores containing calcium have square hysteresis loops and high curie temperatures, making them useful in coincident current memories of digital electronic computers.

  9. ALG-2, a multifunctional calcium binding protein?

    DEFF Research Database (Denmark)

    Tarabykina, Svetlana; Mollerup, Jens; Winding Gojkovic, P.

    2004-01-01

    ALG-2 was originally discovered as a pro-apoptotic protein in a genetic screen. Due to its ability to bind calcium with high affinity it was postulated to provide a link between the known effect of calcium in programmed cell death and the molecular death execution machinery. This review article...

  10. Comparison of Serum Calcium and Magnesium Between ...

    African Journals Online (AJOL)

    The present study compared serum calcium and magnesium in forty preeclamptic (cases) and forty normotensive (control) pregnant women matched for age, parity, and socioeconomic status. Serum calcium and magnesium levels were measured using atomic absorption spectrophotometer. Statistical analysis was done ...

  11. Dairy Dilemma: Are You Getting Enough Calcium?

    Science.gov (United States)

    ... body also needs vitamin D to absorb calcium. Nutrition surveys have shown that most people in the U.S. aren’t getting the calcium they need. If you’re avoiding milk and dairy ... taking nutritional supplements and choosing reduced-lactose or non-dairy ...

  12. CALCIUM AND THE PREVENTION OF COLON CANCER

    NARCIS (Netherlands)

    WELBERG, JWM; KLEIBEUKER, JH; VANDERMEER, R; MULDER, NH; DEVRIES, EGE

    1991-01-01

    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

  13. Calcium Impact on Milk Gels Formation

    DEFF Research Database (Denmark)

    Koutina, Glykeria

    salts. The perturbation of calcium equilibria by these factors will affect the final properties of acid, calcium and rennet milk gels. By decreasing the pH from 6.0 to 5.2 (acid gels), the calcium equilibrium was significantly affected by temperature (4, 20, 30, 40 oC), and different combinations...... of temperature and pH may result in different final structure properties in dairy products such as cheese. A significant amount of calcium remained in the micelles between pH 4.8 and 4.6, this can contribute to the final strength of acid milk gels, such as in yogurt or in cream cheeses. After the gelation point......, a sudden solubilization of micellar calcium was observed at 50 oC and 60 oC, which revealed an interesting role of calcium during acidification at elevated temperatures. After enrichment of milk with calcium D-lactobionate, the added calcium was distributed between the micellar and serum milk phase at pH 6...

  14. Bespuiten met calcium kan neusrot voorkomen

    NARCIS (Netherlands)

    Blom-Zandstra, Greet; Marcelis, L.F.M.

    2000-01-01

    Oorzaak van neusrot bij paprika is een calciumtekort in de vrucht. Een bespuiting met calcium vlak na de bloei heeft een zeer gunstig effect. In bijgaande tabel gegevens over het effect van spuiten met calcium op het optreden van neusrot bij paprika

  15. Calcium and caffeine interaction in increased calcium balance in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Sandra Tavares da Silva

    2013-06-01

    Full Text Available OBJECTIVE: This study investigated the effects of caffeine intake associated with inadequate or adequate calcium intake in laparotomized or ovariectomized rats by means of the calcium balance. Forty adults Wistar rats were ovariectomized or laparotomized. METHODS: The animals (n=40 were randomly placed in eight groups receiving the AIN-93 diet with 100% or 50% of the recommended calcium intake with or without added caffeine (6mg/kg/day. The animals were kept in individuals metabolic cages at a temperature of 24°±2ºC, light/dark cycles of 12/12 hours, and deionized water available ad libitum. On the 8th week of the experiment, food consumption was measured and 24-hour urine and 4-day feces were collected to determine calcium balance [Balance=Ca intake-(Urinary Ca+Fecal Ca]. RESULTS: Animals with adequate calcium intake presented higher balances and rates of calcium absorption and retention (p<0.05 than those with inadequate calcium intake, regardless of caffeine intake (p<0.05. Caffeine intake did not affect urinary calcium excretion but increased balance (p<0.05 in the groups with adequate calcium intake. CONCLUSION: Adequate calcium intake attenuated the negative effects of estrogen deficiency and improved calcium balance even in the presence of caffeine.

  16. Store-operated calcium entry is essential for glial calcium signalling in CNS white matter.

    Science.gov (United States)

    Papanikolaou, M; Lewis, A; Butt, A M

    2017-02-28

    'Calcium signalling' is the ubiquitous response of glial cells to multiple extracellular stimuli. The primary mechanism of glial calcium signalling is by release of calcium from intracellular stores of the endoplasmic reticulum (ER). Replenishment of ER Ca(2+) stores relies on store-operated calcium entry (SOCE). However, despite the importance of calcium signalling in glial cells, little is known about their mechanisms of SOCE. Here, we investigated SOCE in glia of the mouse optic nerve, a typical CNS white matter tract that comprises bundles of myelinated axons and the oligodendrocytes and astrocytes that support them. Using quantitative RT-PCR, we identified Orai1 channels, both Stim1 and Stim2, and the transient receptor potential M3 channel (TRPM3) as the primary channels for SOCE in the optic nerve, and their expression in both astrocytes and oligodendrocytes was demonstrated by immunolabelling of optic nerve sections and cultures. The functional importance of SOCE was demonstrated by fluo-4 calcium imaging on isolated intact optic nerves and optic nerve cultures. Removal of extracellular calcium ([Ca(2+)]o) resulted in a marked depletion of glial cytosolic calcium ([Ca(2+)]i), which recovered rapidly on restoration of [Ca(2+)]o via SOCE. 2-aminoethoxydiphenylborane (2APB) significantly decreased SOCE and severely attenuated ATP-mediated calcium signalling. The results provide evidence that Orai/Stim and TRPM3 are important components of the 'calcium toolkit' that underpins SOCE and the sustainability of calcium signalling in white matter glia.

  17. Plant Calcium Content: Ready to Remodel

    Directory of Open Access Journals (Sweden)

    Mary Lou Guerinot

    2012-08-01

    Full Text Available By identifying the relationship between calcium location in the plant cell and nutrient bioavailability, the plant characteristics leading to maximal calcium absorption by humans can be identified. Knowledge of plant cellular and molecular targets controlling calcium location in plants is emerging. These insights should allow for better strategies for increasing the nutritional content of foods. In particular, the use of preparation-free elemental imaging technologies such as synchrotron X-ray fluorescence (SXRF microscopy in plant biology may allow researchers to understand the relationship between subcellular location and nutrient bioavailability. These approaches may lead to better strategies for altering the location of calcium within the plant to maximize its absorption from fruits and vegetables. These modified foods could be part of a diet for children and adults identified as at-risk for low calcium intake or absorption with the ultimate goal of decreasing the incidence and severity of inadequate bone mineralization.

  18. Endoplasmic reticulum calcium stores in dendritic spines.

    Science.gov (United States)

    Segal, Menahem; Korkotian, Eduard

    2014-01-01

    Despite decades of research, the role of calcium stores in dendritic spines structure, function and plasticity is still debated. The reasons for this may have to do with the multitude of overlapping calcium handling machineries in the neuron, including stores, voltage and ligand gated channels, pumps and transporters. Also, different cells in the brain are endowed with calcium stores that are activated by different receptor types, and their differential compartmentalization in dendrites, spines and presynaptic terminals complicates their analysis. In the present review we address several key issues, including the role of calcium stores in synaptic plasticity, their role during development, in stress and in neurodegenerative diseases. Apparently, there is increasing evidence for a crucial role of calcium stores, especially of the ryanodine species, in synaptic plasticity and neuronal survival.

  19. Application of Calcium Phosphate Materials in Dentistry

    Directory of Open Access Journals (Sweden)

    Jabr S. Al-Sanabani

    2013-01-01

    Full Text Available Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1 application of calcium phosphate into various fields in dentistry; (2 improving mechanical properties of calcium phosphate; (3 biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

  20. Calcium phosphate: a substitute for aluminum adjuvants?

    Science.gov (United States)

    Masson, Jean-Daniel; Thibaudon, Michel; Bélec, Laurent; Crépeaux, Guillemette

    2017-03-01

    Calcium phosphate was used as an adjuvant in France in diphtheria, tetanus, pertussis and poliomyelitis vaccines. It was later completely substituted by alum salts in the late 80's, but it still remains as an approved adjuvant for the World Health Organization for human vaccination. Area covered: Thus, calcium phosphate is now considered as one of the substances that could replace alum salts in vaccines. The aim of this paper is to draw a review of existing data on calcium phosphate as an adjuvant in order to bring out the strengths and weaknesses for its use on a large scale. Expert commentary: Calcium phosphate is a compound naturally present in the organism, safe and already used in human vaccination. Beyond comparisons with the other adjuvants, calcium phosphate represents a good candidate to replace or to complete alum salts as a vaccine adjuvant.

  1. Plant Calcium Content: Ready to Remodel

    Science.gov (United States)

    Yang, Jian; Punshon, Tracy; Guerinot, Mary Lou; Hirschi, Kendal D.

    2012-01-01

    By identifying the relationship between calcium location in the plant cell and nutrient bioavailability, the plant characteristics leading to maximal calcium absorption by humans can be identified. Knowledge of plant cellular and molecular targets controlling calcium location in plants is emerging. These insights should allow for better strategies for increasing the nutritional content of foods. In particular, the use of preparation-free elemental imaging technologies such as synchrotron X-ray fluorescence (SXRF) microscopy in plant biology may allow researchers to understand the relationship between subcellular location and nutrient bioavailability. These approaches may lead to better strategies for altering the location of calcium within the plant to maximize its absorption from fruits and vegetables. These modified foods could be part of a diet for children and adults identified as at-risk for low calcium intake or absorption with the ultimate goal of decreasing the incidence and severity of inadequate bone mineralization. PMID:23016135

  2. The calcium and vitamin D controversy

    DEFF Research Database (Denmark)

    Abrahamsen, Bo

    2017-01-01

    or subanalyses while maintaining balancing. Though large clinical RCTs currently evaluate the effects of higher vitamin D doses (equivalent to 50–83 μg/d) there is no current research effort regarding the calcium controversy. In the absence of such studies it is not possible to provide clinicians with evidence......Areas of the world where vitamin D levels are low for months of the year and intakes of calcium are high have a high prevalence of osteoporosis and cardiovascular disease. This suggests a public health message of avoiding calcium supplements and increasing vitamin D intake. No message could be more...... welcome as vitamin D can be given as a bolus while calcium must be taken daily and may be poorly tolerated. This approach is based on no evidence from intervention studies. Randomized controlled trials (RCTs) suggest that vitamin D given with calcium elicits a small reduction in fracture risk and deaths...

  3. Expert review on coronary calcium

    Directory of Open Access Journals (Sweden)

    Matthew J Budoff

    2008-04-01

    Full Text Available Matthew J Budoff, Khawar M GulDivision of Cardiology, Saint John’s Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, California, USAAbstract: While there is no doubt that high risk patients (those with >20% ten year risk of future cardiovascular event need more aggressive preventive therapy, a majority of cardiovascular events occur in individuals at intermediate risk (10%–20% ten year risk. Accurate risk assessment may be helpful in decreasing cardiovascular events through more appropriate targeting of preventive measures. It has been suggested that traditional risk assessment may be refined with the selective use of coronary artery calcium (CAC or other methods of subclinical atherosclerosis measurement. Coronary calcification is a marker of atherosclerosis that can be quantified with the use of cardiac CT and it is proportional to the extent and severity of atherosclerotic disease. The published studies demonstrate a high sensitivity of CAC for the presence of coronary artery disease but a lower specificity for obstructive CAD depending on the magnitude of the CAC. Several large clinical trials found clear, incremental predictive value of CAC over the Framingham risk score when used in asymptomatic patients. Based on multiple observational studies, patients with increased plaque burdens (increased CAC are approximately ten times more likely to suffer a cardiac event over the next 3–5 years. Coronary calcium scores have outperformed conventional risk factors, highly sensitive C-reactive protein (CRP and carotid intima media thickness (IMT as a predictor of cardiovascular events. The relevant prognostic information obtained may be useful to initiate or intensify appropriate treatment strategies to slow the progression of atherosclerotic vascular disease. Current data suggests intermediate risk patients may benefit most from further risk stratification with cardiac CT, as CAC testing is

  4. Strontium Substitution for Calcium in Lithogenesis

    Science.gov (United States)

    Blaschko, Sarah D.; Chi, Thomas; Miller, Joe; Flechner, Lawrence; Fakra, Sirine; Kapahi, Pankaj; Kahn, Arnold; Stoller, Marshall L.

    2013-01-01

    Purpose Strontium has chemical similarity to calcium, which enables the replacement of calcium by strontium in biomineralization processes. Incorporating strontium into human bone and teeth has been studied extensively but little research has been performed of the incorporation of strontium into urinary calculi. We used synchrotron based x-ray fluorescence and x-ray absorption techniques to examine the presence of strontium in different types of human kidney stones. Materials and Methods Multiple unique human stone samples were obtained via consecutive percutaneous nephrolithotomies/ureteroscopies. A portion of each stone was sent for standard laboratory analysis and a portion was retained for x-ray fluorescence and x-ray absorption measurements. X-ray fluorescence and x-ray absorption measurements determined the presence, spatial distribution and speciation of strontium in each stone sample. Results Traditional kidney stone analyses identified calcium oxalate, calcium phosphate, uric acid and cystine stones. X-ray fluorescence measurements identified strontium in all stone types except pure cystine. X-ray fluorescence elemental mapping of the samples revealed co-localization of calcium and strontium. X-ray absorption measurements of the calcium phosphate stone showed strontium predominately present as strontium apatite. Conclusions Advanced x-ray fluorescence imaging identified strontium in all calcium based stones, present as strontium apatite. This finding may be critical since apatite is thought to be the initial nidus for calcium stone formation. Strontium is not identified by standard laboratory stone analyses. Its substitution for calcium can be reliably identified in stones from multiple calcium based stone formers, which may offer opportunities to gain insight into early events in lithogenesis. PMID:23260568

  5. A comparison of total calcium, corrected calcium, and ionized calcium concentrations as indicators of calcium homeostasis among hypoalbuminemic dogs requiring intensive care.

    Science.gov (United States)

    Sharp, Claire R; Kerl, Marie E; Mann, F A

    2009-12-01

    (1) To evaluate whether total calcium (tCa) correlates with ionized calcium (iCa) in hypoalbuminemic dogs; (2) to evaluate whether calcium adjusted for albumin (Alb), or total protein (TP), or both accurately predict iCa concentrations and hence can be used to monitor calcium homeostasis in critically ill hypoalbuminemic dogs; and (3) to evaluate factors associated with any potential discrepancy in calcium classification between corrected total and ionized values. Prospective observational clinical study. Small animal intensive care unit in a veterinary medical teaching hospital. Twenty-eight client-owned dogs with hypoalbuminemia. None. iCa was determined using ion-specific electrode methodology, on heparinized plasma. The tCa concentration was adjusted for Alb and TP using published equations. In total 29% (8/28) of the hypoalbuminemic, critically ill dogs in this study were hypocalcemic at intensive care unit admission, as determined by iCa measurement. Corrected calcium values failed to accurately classify calcium status in 67.9% and 64.3% of cases, according to whether the Alb-adjusted or TP-adjusted values, respectively, were used. The sensitivity and specificity of the tCa to evaluate hypocalcemia was 100% and 47%, respectively. The sensitivity and specificity of the correction formulae were 37.5% and 79% for the Alb-adjusted values and 37.5% and 74% for TP-adjusted values. tCa overestimated the presence of hypocalcemia and underestimated the presence of normocalcemia, while corrected calcium values overestimated the presence of normocalcemia and underestimated the presence of hypocalcemia. Calcium homeostasis in hypoalbuminemic critically ill dogs should be evaluated by iCa concentrations rather than tCa or calcium adjusted for Alb or TP. Given that tCa has 100% sensitivity for detecting hypocalcemia in this population it is recommended that all hypoalbuminemic and critically ill patients with low tCa should be evaluated with an iCa measurement.

  6. Tuning local calcium availability: cell-type-specific immobile calcium buffer capacity in hippocampal neurons.

    Science.gov (United States)

    Matthews, Elizabeth A; Schoch, Susanne; Dietrich, Dirk

    2013-09-04

    It has remained difficult to ascribe a specific functional role to immobile or fixed intracellular calcium buffers in central neurons because the amount of these buffers is unknown. Here, we explicitly isolated the fixed buffer fraction by prolonged whole-cell patch-clamp dialysis and quantified its buffering capacity in murine hippocampal slices using confocal calcium imaging and the "added-buffer" approach. In dentate granule cells, the calcium binding ratio (κ) after complete washout of calbindin D28k (Cb), κfixed, displayed a substantial value of ∼100. In contrast, in CA1 oriens lacunosum moleculare (OLM) interneurons, which do not contain any known calcium-binding protein(s), κfixed amounted to only ∼30. Based on these values, a theoretical analysis of dendritic spread of calcium after local entry showed that fixed buffers, in the absence of mobile species, decrease intracellular calcium mobility 100- and 30-fold in granule cells and OLM cells, respectively, and thereby strongly slow calcium signals. Although the large κfixed alone strongly delays the spread of calcium in granule cells, this value optimizes the benefits of additionally expressing the mobile calcium binding protein Cb. With such high κfixed, Cb effectively increases the propagation velocity to levels seen in OLM cells and, contrary to expectation, does not affect the peak calcium concentration close to the source but sharpens the spatial and temporal calcium gradients. The data suggest that the amount of fixed buffers determines the temporal availability of calcium for calcium-binding partners and plays a pivotal role in setting the repertoire of cellular calcium signaling regimens.

  7. Case-control study of breast milk calcium in mothers of children with and without nutritional rickets.

    Science.gov (United States)

    Thacher, Tom D; Pettifor, John M; Fischer, Philip R; Okolo, Selina N; Prentice, Ann

    2006-07-01

    Despite similarly low calcium intakes and normal vitamin D status, only some Nigerian children develop nutritional rickets. We hypothesized that mothers with children who had developed rickets might have lower breast-milk calcium concentration than mothers with normal children and compared the breast-milk calcium concentration of mothers who had had children with rickets with those who had not (controls). We collected breast milk from 35 Nigerian mothers who had previously had children with nutritional rickets. For each case mother, we collected breast milk from three matched control mothers at the same stage of lactation (+/-4 weeks) who had had no children with rickets. Data were collected about parity, stage of lactation, and the infant's intake. The mother's bone density was measured. The mean breast milk calcium concentration of mothers of children with rickets (4.30+/-1.24 mmol/L) was less than that of control mothers (4.65+/-1.03 mmol/L; P=0.034 in multivariate regression controlling for duration of lactation and resumption of menses). Forearm bone mineral content was significantly related to breast milk calcium concentration (r=0.20) after adjusting for height, weight, and bone area (P=0.028). Reduced breast-milk calcium concentration may contribute to a reduced calcium intake in infancy and predispose children to nutritional rickets.

  8. Calcium and Vitamin D Supplementation for Prevention of Preeclampsia: A Systematic Review and Network Meta-Analysis

    Science.gov (United States)

    Khaing, Win; Vallibhakara, Sakda Arj-Ong; Tantrakul, Visasiri; Vallibhakara, Orawin; Rattanasiri, Sasivimol; McEvoy, Mark; Attia, John; Thakkinstian, Ammarin

    2017-01-01

    Vitamin D supplementation effects with or without calcium in pregnancy for reducing risk of preeclampsia and gestational or pregnancy induced hypertension are controversial. Literature was systematically searched in Medline, Scopus and Cochrane databases from inception to July 2017. Only randomized controlled trials (RCTs) in English were selected if they had any pair of interventions (calcium, vitamin D, both, or placebo). Systematic review with two-step network-meta-analysis was used to indirectly estimate supplementary effects. Twenty-seven RCTs with 28,000 women were eligible. A direct meta-analysis suggested that calcium, vitamin D, and calcium plus vitamin D could lower risk of preeclampsia when compared to placebo with the pooled risk ratios (RRs) of 0.54 (0.41, 0.70), 0.47 (0.24, 0.89) and 0.50 (0.32, 0.78), respectively. Results of network meta-analysis were similar with the corresponding RRs of 0.49 (0.35, 0.69), 0.43 (0.17, 1.11), and 0.57 (0.30, 1.10), respectively. None of the controls were significant. Efficacy of supplementation, which was ranked by surface under cumulative ranking probabilities, were: vitamin D (47.4%), calcium (31.6%) and calcium plus vitamin D (19.6%), respectively. Calcium supplementation may be used for prevention for preeclampsia. Vitamin D might also worked well but further large scale RCTs are warranted to confirm our findings. PMID:29057843

  9. Calcium and Vitamin D Supplementation for Prevention of Preeclampsia: A Systematic Review and Network Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Win Khaing

    2017-10-01

    Full Text Available Vitamin D supplementation effects with or without calcium in pregnancy for reducing risk of preeclampsia and gestational or pregnancy induced hypertension are controversial. Literature was systematically searched in Medline, Scopus and Cochrane databases from inception to July 2017. Only randomized controlled trials (RCTs in English were selected if they had any pair of interventions (calcium, vitamin D, both, or placebo. Systematic review with two-step network-meta-analysis was used to indirectly estimate supplementary effects. Twenty-seven RCTs with 28,000 women were eligible. A direct meta-analysis suggested that calcium, vitamin D, and calcium plus vitamin D could lower risk of preeclampsia when compared to placebo with the pooled risk ratios (RRs of 0.54 (0.41, 0.70, 0.47 (0.24, 0.89 and 0.50 (0.32, 0.78, respectively. Results of network meta-analysis were similar with the corresponding RRs of 0.49 (0.35, 0.69, 0.43 (0.17, 1.11, and 0.57 (0.30, 1.10, respectively. None of the controls were significant. Efficacy of supplementation, which was ranked by surface under cumulative ranking probabilities, were: vitamin D (47.4%, calcium (31.6% and calcium plus vitamin D (19.6%, respectively. Calcium supplementation may be used for prevention for preeclampsia. Vitamin D might also worked well but further large scale RCTs are warranted to confirm our findings.

  10. Diagnosis and assessment of skeletal related disease using calcium 41

    Science.gov (United States)

    Hillegonds, Darren J [Oakland, CA; Vogel, John S [San Jose, CA; Fitzgerald, Robert L [Encinitas, CA; Deftos, Leonard J [Del Mar, CA; Herold, David [Del Mar, CA; Burton, Douglas W [San Diego, CA

    2012-05-15

    A method of determining calcium metabolism in a patient comprises the steps of administering radioactive calcium isotope .sup.41Ca to the patient, allowing a period of time to elapse sufficient for dissemination and reaction of the radioactive calcium isotope .sup.41Ca by the patient, obtaining a sample of the radioactive calcium isotope .sup.41Ca from the patient, isolating the calcium content of the sample in a form suitable for precise measurement of isotopic calcium concentrations, and measuring the calcium content to determine parameters of calcium metabolism in the patient.

  11. 46 CFR 62.35-35 - Starting systems for internal-combustion engines.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Starting systems for internal-combustion engines. 62.35-35 Section 62.35-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE... Starting systems for internal-combustion engines. The starting systems for propulsion engines and for prime...

  12. Non-calcium desulphurisation technologies

    Energy Technology Data Exchange (ETDEWEB)

    Qian Zhu [IEA Clean Coal Centre, London (United Kingdom)

    2010-06-15

    Flue gas desulphurisation (FGD) is traditionally based on limestone/lime sorbent. The majority of the installed FGD systems worldwide use limestone or lime as sorbent. However, technologies are rapidly evolving that allow desulphurisation in regions where there are limited resources of lime or limestone. These technologies provide alternatives to limestone/lime scrubbers for efficient and cost effective control of SO{sub 2} emissions from coal combustion. This report reviews the existing and emerging non-calcium based FGD processes as well as FGD technologies currently under development that apply new concepts and different approaches. It looks at the fundamentals and features of these processes, the recent technical advances and their applications in coal-fired power plants. The capital and operating costs of the processes are evaluated where information available. 66 refs., 15 figs., 10 tabs.

  13. Calcium-sensitive immunoaffinity chromatography

    DEFF Research Database (Denmark)

    Henriksen, Maiken L; Lindhardt Madsen, Kirstine; Skjoedt, Karsten

    2014-01-01

    Immunoaffinity chromatography is a powerful fractionation technique that has become indispensable for protein purification and characterization. However, it is difficult to retrieve bound proteins without using harsh or denaturing elution conditions, and the purification of scarce antigens...... to homogeneity may be impossible due to contamination with abundant antigens. In this study, we purified the scarce, complement-associated plasma protein complex, collectin LK (CL-LK, complex of collectin liver 1 and kidney 1), by immunoaffinity chromatography using a calcium-sensitive anti-collectin-kidney-1 m...... chromatography was superior to the traditional immunoaffinity chromatographies and resulted in a nine-fold improvement of the purification factor. The technique is applicable for the purification of proteins in complex mixtures by single-step fractionation without the denaturation of eluted antigens...

  14. Pengujian Kehandalan LM 35 Sebagai Sensor Temperatur

    OpenAIRE

    Nainggolan, Johannes

    2015-01-01

    Pada Tugas Akhir ini Penulis membahas masalah yang berjudul “Pengujian Kehandalan LM 35 Sebagai Sensor Temperatur”. Alat ini berfungsi untuk mengukur temperature suhu yang ada di dalam ruangan. Dalam hal ini simulasi dilakukan dengan menggunakan Mikrokontroller ATMega 8535, sensor suhu LM 35, PSA, Seven Segment. Pada pengujian kali ini, penulis ingin melihat seberapa besar keakuratan LM 35 dalam mengukur temperatur suhu pada bahan pengujian dengan menganalisis air raksa, ter...

  15. 40 CFR 35.925-7 - Design.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Design. 35.925-7 Section 35.925-7... ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-7 Design. That the treatment works design will be (in the case of projects involving step 2) or has been (in the case of projects for...

  16. Calcium and available phosphorus levels for laying hens in second production cycle

    Directory of Open Access Journals (Sweden)

    K Pelicia

    2009-03-01

    Full Text Available This experiment studied the effect of four calcium (3.0, 3.5, 4.0, and 4.5% and four available phosphorus levels (0.25, 0.30, 0.35, and 0.40% in the diet of semi-heavy commercial layers after molting. Hisex Brown® layers between 90 and 108 weeks of age were distributed in a completely randomized experimental design with a 4x4 factorial arrangement with 16 treatments of five replicates of eight birds each. mortality, egg production, feed intake, egg mass, average egg weight, calcium and phosphorus intake, feed conversion ratio (per dozen eggs and per kg eggs, eggshell percentage and thickness, eggshell strength, eggshell weight per surface area (ESWSA, yolk percentage and color, albumen percentage, albumen and yolk heights, and blood and excreta calcium and phosphorus concentrations. There was no interaction (P>0.05 between dietary Ca and avP for any of the studied parameters. There were linear increases in Ca intake (P0.05 by dietary Ca and avP levels. The diet containing 4.5% calcium improved feed conversion ratio per dozen eggs and eggshell quality. The lowest avP level fed (0.25% is sufficient to maintain the performance and the egg quality of semi-heavy commercial layers after molting.

  17. Relationship between milk and calcium intake and lipid metabolism in female patients with type 2 diabetes.

    Science.gov (United States)

    Kim, JaeHee; Hwang, Ji-Yun; Kim, Ki Nam; Choi, Young-Ju; Chang, Namsoo; Huh, Kap-Bum

    2013-05-01

    This study was conducted to determine the association between intake of milk and dairy products as well as calcium and biomarkers related to lipid metabolism in Korean female patients with type 2 diabetes. A cohort of 509 female subjects (mean age: 59.0 years; range: 35-80 years) was recruited from Huh's Diabetes Clinic in Seoul between 2005 and 2010. Dietary intake was assessed using a validated food-frequency questionnaire. Subjects were divided into three groups on the basis of their daily intake of milk and dairy products [200 g/day (>200-1201 g/day)] and then further divided into two groups according to their daily calcium intake: below and above the estimated average requirement (EAR). After adjustment for age, body mass index, energy intake, exercise, use of nutritional supplements and cholesterol medication, the level of serum high-density lipoprotein (HDL)-cholesterol was significantly higher in subjects with milk and dairy products consumption of >200 g/day than in subjects in the other two groups. Those subjects with a milk and dairy products consumption of >200 g/day had significantly higher levels of apolipoprotein A-1 and a significantly lower atherogenic index than the other two groups. Patients with a calcium intake above the EAR exhibited a significantly greater serum HDL-cholesterol level than those with a calcium intake below the EAR. Milk and dairy products, good sources of calcium, play a positive role in lipid profiles in female patients with type 2 diabetes.

  18. Identification of mitochondrial DNA polymorphisms that alter mitochondrial matrix pH and intracellular calcium dynamics.

    Directory of Open Access Journals (Sweden)

    An-a Kazuno

    2006-08-01

    Full Text Available Mitochondrial DNA (mtDNA is highly polymorphic, and its variations in humans may contribute to individual differences in function as well as susceptibility to various diseases such as Parkinson disease, Alzheimer disease, bipolar disorder, and cancer. However, it is unclear whether and how mtDNA polymorphisms affect intracellular function, such as calcium signaling or pH regulation. Here we searched for mtDNA polymorphisms that have intracellular functional significance using transmitochondrial hybrid cells (cybrids carrying ratiometric Pericam (RP, a fluorescent calcium indicator, targeted to the mitochondria and nucleus. By analyzing the entire mtDNA sequence in 35 cybrid lines, we found that two closely linked nonsynonymous polymorphisms, 8701A and 10398A, increased the basal fluorescence ratio of mitochondria-targeted RP. Mitochondrial matrix pH was lower in the cybrids with 8701A/10398A than it was in those with 8701G/10398G, suggesting that the difference observed by RP was mainly caused by alterations in mitochondrial calcium levels. Cytosolic calcium response to histamine also tended to be higher in the cybrids with 8701A/10398A. It has previously been reported that 10398A is associated with an increased risk of Parkinson disease, Alzheimer disease, bipolar disorder, and cancer, whereas 10398G associates with longevity. Our findings suggest that these mtDNA polymorphisms may play a role in the pathophysiology of these complex diseases by affecting mitochondrial matrix pH and intracellular calcium dynamics.

  19. Calcium and Bone Homeostasis During 4-6 Months Space Flight

    Science.gov (United States)

    Smith, Scott M.; OBrien, K.; Wastney, M.; Morukov, B.; Larina, I.; Abrams, S.; Lane, H.; Nillen, J.; Davis-Street, J.; Paloski, W. H. (Technical Monitor)

    2000-01-01

    Bone and calcium homeostasis are altered by weightlessness. We previously reported calcium studies on three subjects from the first joint US/Russian mission to Mir. We report here data on an additional three male subjects, whose stays on Mir were 4 (n= 1) and 6 (n=2) mos. Data were collected before, during, and after the missions. Inflight studies were conducted at 2-3 mos. Endocrine and biochemical indices were measured, along with 3-wk calcium tracer studies. Percent differences are reported compared to preflight. Ionized calcium was unchanged (2.8 +/-2.1 %) during flight. Calcium absorption was variable inflight, but was decreased after landing. Vitamin D stores were decreased 35 +/-24% inflight, similar to previous reports. Serum PTH was decreased 59 +/-9% during flight (greater than we previously reported), while 1,25(OH)(sub 2)-Vitamin D was decreased in 2 of 3 subjects. Markers of bone resorption (e.g., crosslinks) were increased in all subjects. Bone-specific alkaline phosphatase was decreased (n=1) or unchanged (n=2), while osteocalcin was decreased 34 +/-23%. Previously presented data showed that inflight bone loss is associated with increased resorption and unchanged/decreased formation. The data reported here support these earlier findings. These studies will help to extend our understanding of space flight-induced bone loss, and of bone loss associated with diseases such as osteoporosis or paralysis.

  20. Bone healing around nanocrystalline hydroxyapatite, deproteinized bovine bone mineral, biphasic calcium phosphate, and autogenous bone in mandibular bone defects

    DEFF Research Database (Denmark)

    Broggini, Nina; Bosshardt, Dieter D; Jensen, Simon S

    2015-01-01

    with nanocrystalline hydroxyapatite (HA-SiO), deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate (BCP) with a 60/40% HA/β-TCP (BCP 60/40) ratio, or particulate autogenous bone (A) for histological and histomorphometric analysis. At 2 weeks, percent filler amongst the test groups (DBBM (35.65%), HA...

  1. Calcium currents in a fast-twitch skeletal muscle of the rat.

    Science.gov (United States)

    Donaldson, P L; Beam, K G

    1983-10-01

    Slow ionic currents were measured in the rat omohyoid muscle with the three-microelectrode voltage-clamp technique. Sodium and delayed rectifier potassium currents were blocked pharmacologically. Under these conditions, depolarizing test pulses elicited an early outward current, followed by a transient slow inward current, followed in turn by a late outward current. The early outward current appeared to be a residual delayed rectifier current. The slow inward current was identified as a calcium current on the basis that (a) its magnitude depended on extracellular calcium concentration, (b) it was blocked by the addition of the divalent cations cadmium or nickel, and reduced in magnitude by the addition of manganese or cobalt, and (c) barium was able to replace calcium as an inward current carrier. The threshold potential for inward calcium current was around -20 mV in 10mM extracellular calcium and about -35 mV in 2 mM calcium. Currents were net inward over part of their time course for potentials up to at least +30 mV. At temperatures of 20-26 degrees C, the peak inward current (at approximately 0 mV) was 139 +/- 14 microA/cm2 (mean +/- SD), increasing to 226 +/- 28 microA/cm2 at temperatures of 27-37 degrees C. The late outward current exhibited considerable fiber-to-fiber variability. In some fibers it was primarily a time-independent, nonlinear leakage current. In other fibers it was primarily a time-independent, nonlinear leakage current. In other fibers it appeared to be the sum of both leak and a slowly activated outward current. The rate of activation of inward calcium current was strongly temperature dependent. For example, in a representative fiber, the time-to-peak inward current for a +10-mV test pulse decreased from approximately 250 ms at 20 degrees C to 100 ms at 30 degrees C. At 37 degrees C, the time-to-peak current was typically approximately 25 ms. The earliest phase of activation was difficult to quantify because the ionic current was partially

  2. [Food sources and average intake of calcium in a representative sample of Spanish schoolchildren].

    Science.gov (United States)

    Ortega, R M; López-Sobaler, A M; Jiménez Ortega, A I; Navia Lombán, B; Ruiz-Roso Calvo de Mora, B; Rodríguez-Rodríguez, E; López Plaza, B

    2012-01-01

    There is controversy about the adequacy of calcium intake to that recommended in Spanish schoolchildren. Some studies indicate that the intake is inadequate in a variable percentage of children, while others insist on the danger of an excessive intake in a huge percentage of this population. To assess calcium intake and food sources of this nutrient in a representative sample of Spanish children and to judge the adequacy of its contribution to the coverage of recommended intakes. 903 schoolchildren (7 to 11 years) from 10 Spanish provinces (Tarragona, Caceres, Burgos, Guadalajara, Valencia, Salamanca, Cordoba, Vizcaya, Lugo and Madrid) were studied. They constituted a representative sample of the Spanish schoolchildren population. The energy and nutrient intake was determined using a "Food record questionnaire" for 3 days, including a Sunday. Calcium intake was compared with the recommended intakes (RI) for the mineral. Weight and height were recorded and body mass index (BMI) calculated. In the studied group (55.3% girls and 44.7% of children), 30.7% had an excess body weight (23.3% overweight and 7.4% obesity). Calcium intake was 859.9 ± 249.2 mg / day (79.5% of the recommendations). 76.7% of children had intakes below 100% of those recommended and 40.1% below of 67% of RI. The ratios calcium/phosphorus (0.74 ± 0.21) and calcium/protein (10.1 ± 2.8) and the index of nutritional quality for calcium (0.78 ± 0.29) were lower than recommended in 91.6%, 99.8% and 81.1% of children, respectively. Dietary calcium came from dairy products (64.7%), dietetic products and infant formulae (7.6%), cereals (7.3%), vegetables (3.5%), fruits (3.4%), pre-cooked meals (3.3%), meats (2.8%), fishes (2.8%) and pulses (2.2%), with no differences by gender. Calcium intake was lower than recommended in 76.7% of the children and 40.1% had insufficient intake (calcium source was dairy products (64.7%), increase consumption of this food group is recommended, especially in the 37.1% of

  3. Relationship of calcium absorption with 25(OH)D and calcium intake in children with rickets.

    Science.gov (United States)

    Thacher, Tom D; Abrams, Steven A

    2010-11-01

    Nutritional rickets has long been considered a disease caused by vitamin D deficiency, but recent data indicate that inadequate dietary calcium intake is an important cause of rickets, particularly in tropical countries. Children with rickets due to calcium deficiency do not have very low 25(OH)D concentrations, and serum 1,25(OH)(2) D values are markedly elevated. Studies of Nigerian children with rickets demonstrated they have high fractional calcium absorption. A high-phytate diet was demonstrated to increase calcium absorption compared with the fasting state, and enzymatic dephytinization did not significantly improve calcium absorption. When given vitamin D, children with rickets have a marked increase in 1,25(OH)(2) D concentrations without any change in fractional calcium absorption. No positive relationship was found between fractional calcium absorption and serum 25(OH)D concentrations in children on low-calcium diets. More research is needed to understand the interaction between calcium and vitamin D and the role of vitamin D in calcium absorption. © 2010 International Life Sciences Institute.

  4. Calcium phosphate scaffold from biogenic calcium carbonate by fast ambient condition reactions

    Science.gov (United States)

    Dutta, Abhishek; Fermani, Simona; Arjun Tekalur, Srinivasan; Vanderberg, Abigail; Falini, Giuseppe

    2011-12-01

    Calcium phosphate biogenic materials are biocompatible and promote bioactivity and osteoconductivity, which implies their natural affinity and tendency to bond directly to bones subsequently replacing the host bone after implantation owing to its biodegradability. Calcium hydrogen phosphate dihydrate, CaHPO 4·2H 2O, is known to be a nucleation precursor, in aqueous solutions, for apatitic calcium phosphates and, hence, a potential starting material for bone substitutes. Numerous approaches, via hydrothermal and ambient synthetic routes, have been used to produce calcium phosphate from biogenic calcium carbonate, taking advantage of the peculiar architecture and composition of the latter. In this article, the lamellar region of the cuttlefish bone ( Sepia officinalis) was used as a framework for the organized deposition of calcium phosphate crystals, at ambient conditions via a fast procedure involving an amorphous calcium carbonate intermediate, and ending with a conversion to calcium phosphate and a fixation procedure, thereby resulting in direct conversion of biogenic calcium carbonate into calcium phosphates at ambient conditions from the scale of months to hours.

  5. Transgenic plants with increased calcium stores

    Science.gov (United States)

    Wyatt, Sarah (Inventor); Tsou, Pei-Lan (Inventor); Robertson, Dominique (Inventor); Boss, Wendy (Inventor)

    2004-01-01

    The present invention provides transgenic plants over-expressing a transgene encoding a calcium-binding protein or peptide (CaBP). Preferably, the CaBP is a calcium storage protein and over-expression thereof does not have undue adverse effects on calcium homeostasis or biochemical pathways that are regulated by calcium. In preferred embodiments, the CaBP is calreticulin (CRT) or calsequestrin. In more preferred embodiments, the CaBP is the C-domain of CRT, a fragment of the C-domain, or multimers of the foregoing. In other preferred embodiments, the CaBP is localized to the endoplasmic reticulum by operatively associating the transgene encoding the CaBP with an endoplasmic reticulum localization peptide. Alternatively, the CaBP is targeted to any other sub-cellular compartment that permits the calcium to be stored in a form that is biologically available to the plant. Also provided are methods of producing plants with desirable phenotypic traits by transformation of the plant with a transgene encoding a CaBP. Such phenotypic traits include increased calcium storage, enhanced resistance to calcium-limiting conditions, enhanced growth and viability, increased disease and stress resistance, enhanced flower and fruit production, reduced senescence, and a decreased need for fertilizer production. Further provided are plants with enhanced nutritional value as human food or animal feed.

  6. In vitro antioxidant properties of calcium dobesilate.

    Science.gov (United States)

    Brunet, J; Farine, J C; Garay, R P; Hannaert, P

    1998-01-01

    Calcium dobesilate, a vascular protective agent, was tested in vitro for its scavenging action against oxygen free radicals. Calcium dobesilate was as potent as rutin to scavenge hydroxyl radicals (IC50 = 1.1 vs 0.7 microM, respectively). It was also able to scavenge superoxide radicals, but with 23 times less potency than rutin (IC50 = 682 vs 30 microM, respectively). Calcium dobesilate significantly reduced platelet activating factor (PAF)-induced chemiluminescence in human PMN cells and lipid peroxidation by oxygen free radicals in human erythrocyte membranes, although these actions required calcium dobesilate concentrations > or = 50 microM. Finally, in cultured bovine aortic endothelial cells, magnesium dobesilate reduced the increase in cytosolic free calcium induced by hydrogen peroxide and inhibited phenazine methosulfate-induced cell potassium loss. In conclusion, calcium dobesilate was effective in scavenging hydroxyl radicals in vitro, at therapeutically relevant concentrations. Conversely, higher concentrations of the compound were required to scavenge superoxide radicals or to protect the cells against the deleterious effects of intracellular reactive oxygen species. Further studies in vivo are required to determine if these antioxidant properties of calcium dobesilate can play a role in its vascular protective mechanisms.

  7. Intracellular sphingosine releases calcium from lysosomes

    Science.gov (United States)

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

    2015-01-01

    To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in late endosomes and lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC. DOI: http://dx.doi.org/10.7554/eLife.10616.001 PMID:26613410

  8. Calcium content of different compositions of gallstones and pathogenesis of calcium carbonate gallstones.

    Science.gov (United States)

    Yu, Ji-Kuen; Pan, Huichin; Huang, Shing-Moo; Huang, Nan-Lan; Yao, Chung-Chin; Hsiao, Kuang-Ming; Wu, Chew-Wun

    2013-01-01

    Our aim was to investigate the calcium content of different gallstone compositions and the pathogenic mechanisms of calcium carbonate gallstones. Between August 2001 and July 2007, gallstones from 481 patients, including 68 calcium carbonate gallstones, were analyzed for total calcium content. Gallbladder bile samples from 33 cases and six controls were analyzed for pH, carbonate anion level, free-ionized calcium concentration and saturation index for calcium carbonate. Total calcium content averaged 75.6 %, 11.8 %, and 4.2 % for calcium carbonate, calcium bilirubinate and cholesterol gallstones. In 29.4 % of patients, chronic and/or intermittent cystic duct obstructions were caused by polypoid lesions in the neck region and 70.6 % were caused by stones. A total of 82 % of patients had chronic low-grade inflammation of the gallbladder wall and 18.0 % had acute inflammatory exacerbations. In the bile, we found the mean pH, mean carbonate anion, free-ionized calcium concentrations, and mean saturation index for calcium carbonate to be elevated in comparison to controls. From our study, we found chronic and/or intermittent cystic duct obstructions and low-grade GB wall inflammation lead to GB epithelium hydrogen secretion dysfunction. Increased calcium ion efflux into the GB lumen combined with increased carbonate anion presence increases SI_CaCO(3) from 1 to 22.4. Thus, in an alkaline milieu with pH 7.8, calcium carbonate begins to aggregate and precipitate. Copyright © 2012. Published by Elsevier B.V.

  9. Effect of calcium intake on urinary oxalate excretion in calcium stone-forming patients

    Directory of Open Access Journals (Sweden)

    Nishiura J.L.

    2002-01-01

    Full Text Available Dietary calcium lowers the risk of nephrolithiasis due to a decreased absorption of dietary oxalate that is bound by intestinal calcium. The aim of the present study was to evaluate oxaluria in normocalciuric and hypercalciuric lithiasic patients under different calcium intake. Fifty patients (26 females and 24 males, 41 ± 10 years old, whose 4-day dietary records revealed a regular low calcium intake (<=500 mg/day, received an oral calcium load (1 g/day for 7 days. A 24-h urine was obtained before and after load and according to the calciuria under both diets, patients were considered as normocalciuric (NC, N = 15, diet-dependent hypercalciuric (DDHC, N = 9 or diet-independent hypercalciuric (DIHC, N = 26. On regular diet, mean oxaluria was 30 ± 14 mg/24 h for all patients. The 7-day calcium load induced a significant decrease in mean oxaluria compared to the regular diet in NC and DIHC (20 ± 12 vs 26 ± 7 and 27 ± 18 vs 32 ± 15 mg/24 h, respectively, P<0.05 but not in DDHC patients (22 ± 10 vs 23 ± 5 mg/24 h. The lack of an oxalate decrease among DDHC patients after the calcium load might have been due to higher calcium absorption under higher calcium supply, with a consequent lower amount of calcium left in the intestine to bind with oxalate. These data suggest that a long-lasting regular calcium consumption <500 mg was not associated with high oxaluria and that a subpopulation of hypercalciuric patients who presented a higher intestinal calcium absorption (DDHC tended to hyperabsorb oxalate as well, so that oxaluria did not change under different calcium intake.

  10. Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture*

    Science.gov (United States)

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

    2015-01-01

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

  11. Protein-Mediated Precipitation of Calcium Carbonate

    Directory of Open Access Journals (Sweden)

    Izabela Polowczyk

    2016-11-01

    Full Text Available Calcium carbonate is an important component in exoskeletons of many organisms. The synthesis of calcium carbonate was performed by mixing dimethyl carbonate and an aqueous solution of calcium chloride dihydrate. The precipitation product was characterized by means of scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, and Fourier transform infrared spectroscopy (FTIR measurements. In addition, the turbidity of the reaction solution was acquired to monitor the kinetics of the calcium carbonate structure’s growth in the investigated system. In this study, samples of CaCO3 particles obtained with individual proteins, such as ovalbumin, lysozyme, and a mixture of the proteins, were characterized and compared with a control sample, i.e., synthesized without proteins. The obtained data indicated that the addition of ovalbumin to the reaction changed the morphology of crystals from rhombohedral to ‘stack-like’ structures. Lysozyme, however, did not affect the morphology of calcium carbonate, yet the presence of the protein mixture led to the creation of more complex composites in which the calcium carbonate crystals were constructed in protein matrices formed by the ovalbumin-lysozyme interaction. It was also observed that in the protein mixture, ovalbumin has a major influence on the CaCO3 formation through a strong interaction with calcium ions, which leads to the coalescence and creation of a steric barrier reducing particle growth. The authors proposed a mechanism of calcium carbonate grain growth in the presence of both proteins, taking into account the interaction of calcium ions with the protein.

  12. Protein-Mediated Precipitation of Calcium Carbonate

    Science.gov (United States)

    Polowczyk, Izabela; Bastrzyk, Anna; Fiedot, Marta

    2016-01-01

    Calcium carbonate is an important component in exoskeletons of many organisms. The synthesis of calcium carbonate was performed by mixing dimethyl carbonate and an aqueous solution of calcium chloride dihydrate. The precipitation product was characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) measurements. In addition, the turbidity of the reaction solution was acquired to monitor the kinetics of the calcium carbonate structure’s growth in the investigated system. In this study, samples of CaCO3 particles obtained with individual proteins, such as ovalbumin, lysozyme, and a mixture of the proteins, were characterized and compared with a control sample, i.e., synthesized without proteins. The obtained data indicated that the addition of ovalbumin to the reaction changed the morphology of crystals from rhombohedral to ‘stack-like’ structures. Lysozyme, however, did not affect the morphology of calcium carbonate, yet the presence of the protein mixture led to the creation of more complex composites in which the calcium carbonate crystals were constructed in protein matrices formed by the ovalbumin-lysozyme interaction. It was also observed that in the protein mixture, ovalbumin has a major influence on the CaCO3 formation through a strong interaction with calcium ions, which leads to the coalescence and creation of a steric barrier reducing particle growth. The authors proposed a mechanism of calcium carbonate grain growth in the presence of both proteins, taking into account the interaction of calcium ions with the protein. PMID:28774065

  13. Choroid vascular occlusion and ischemic optic neuropathy after facial calcium hydroxyapatite injection- a case report

    OpenAIRE

    Chou, Chien-Chih; Chen, Hsin-Han; Tsai, Yi-Yu; Li, You-Ling; Lin, Hui-Ju

    2015-01-01

    Background We reported a case of sudden monocular vision loss after calcium hydroxyapatite (CaHA) injection into the nasal tip and dorsum with detailed retina images. Case presentation A healthy, 35-year-old woman received CaHA filler injection for nose augmentation. Ten minutes after the procedure, she developed nausea, vomiting, headache, ptosis, and left periorbital pain. After 30?minutes, she complained of progressively blurring vision in the left eye. The best-corrected visual acuity (BC...

  14. 24 CFR 280.35 - Minimum participation.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Minimum participation. 280.35 Section 280.35 Housing and Urban Development Regulations Relating to Housing and Urban Development... Minimum participation. Except as provided in paragraph (a) or (b) of this section, the recipient may not...

  15. 40 CFR 35.3035 - Public participation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Public participation. 35.3035 Section 35.3035 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... participation. (a) Public participation during the development, review, approval, and substantial revision of...

  16. 40 CFR 35.927-3 - Rehabilitation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Rehabilitation. 35.927-3 Section 35.927... Rehabilitation. (a) Subject to State concurrence, the Regional Administrator may authorize the grantee to perform minor rehabilitation concurrently with the sewer system evaluation survey in any step under a grant if...

  17. 14 CFR 375.35 - Free transportation.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Free transportation. 375.35 Section 375.35 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) SPECIAL... transportation. (a) Foreign civil aircraft may be navigated in the United States by a foreign air carrier for the...

  18. 5 CFR 1201.35 - Substituting parties.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Substituting parties. 1201.35 Section... AND PROCEDURES Procedures for Appellate Cases Parties, Representatives, and Witnesses § 1201.35 Substituting parties. (a) If an appellant dies or is otherwise unable to pursue the appeal, the processing of...

  19. 40 CFR 35.6245 - Allowable activities.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Allowable activities. 35.6245 Section... Actions Support Agency Cooperative Agreements § 35.6245 Allowable activities. Support agency activities are those activities conducted by the recipient to ensure its meaningful and substantial involvement...

  20. 43 CFR 423.35 - Animals.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Animals. 423.35 Section 423.35 Public... Animals. (a) You must not bring pets or other animals into public buildings, public transportation vehicles, or sanitary facilities. This provision does not apply to properly trained animals assisting...

  1. 40 CFR 35.3105 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... ASSISTANCE State Water Pollution Control Revolving Funds § 35.3105 Definitions. Words and terms that are not... and 40 CFR part 35, subpart I. (a) Act. The Federal Water Pollution Control Act, more commonly known as the Clean Water Act (Pub. L. 92-500), as amended by the Water Quality Act of 1987 (Pub. L. 100-4...

  2. 31 CFR 360.35 - Payment (redemption).

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Payment (redemption). 360.35 Section 360.35 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL... remittances, including checks and electronic payments, drawn against funds of the United States. See...

  3. 29 CFR 1915.35 - Painting.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Painting. 1915.35 Section 1915.35 Labor Regulations... Painting. (a) Paints mixed with toxic vehicles or solvents. (1) When paints mixed with toxic vehicles or.... (2) Where brush application of paints with toxic solvents is done in confined spaces or in other...

  4. 18 CFR 35.39 - Affiliate restrictions.

    Science.gov (United States)

    2010-04-01

    ... with a market-regulated power sales affiliate if the sharing could be used to the detriment of captive... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Affiliate restrictions. 35.39 Section 35.39 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION...

  5. 36 CFR 223.35 - Performance bond.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Performance bond. 223.35 Section 223.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SALE AND... Performance bond. Timber sale contracts may require the purchaser to furnish a performance bond for...

  6. 49 CFR 260.35 - Environmental assessment.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Environmental assessment. 260.35 Section 260.35... assessment. (a) The provision of financial assistance by the Administrator under this Part is subject to a... Environmental Procedures and, if not, to prepare or have prepared an Environmental Assessment leading to an...

  7. 27 CFR 41.35 - Cigarette tubes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following rates...

  8. 7 CFR 35.14 - Notice.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Notice. 35.14 Section 35.14 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... offers for shipment, any variety of vinifera species table grapes to any foreign destination in violation...

  9. 7 CFR 35.6 - Shipment.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Shipment. 35.6 Section 35.6 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... country regardless of the number of consignees, receivers, or ports of destination in that country. [41 FR...

  10. 24 CFR 1720.35 - Prefiling assistance.

    Science.gov (United States)

    2010-04-01

    ..., Office of Interstate Land Sales Registration, Department of Housing and Urban Development, 451 Seventh... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Prefiling assistance. 1720.35 Section 1720.35 Housing and Urban Development Regulations Relating to Housing and Urban Development...

  11. Your Child's Development: 3-5 Days

    Science.gov (United States)

    ... Teens a Voice in Health Care Decisions Your Child’s Development: 3-5 Days KidsHealth > For Parents > Your Child’s Development: 3-5 Days Print A A A en ... the sole of the foot Social and Emotional Development soothed by a ... When to Talk to Your Doctor Every child develops at his or her own pace, but ...

  12. 7 CFR 35.13 - Minimum quantity.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Minimum quantity. 35.13 Section 35.13 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... part, transport or receive for transportation to any foreign destination, a shipment of 25 packages or...

  13. 40 CFR 35.918 - Individual systems.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Individual systems. 35.918 Section 35... Individual systems. (a) For references to individual systems, the following definitions apply: (1) Individual systems. Privately owned alternative wastewater treatment works (including dual waterless/gray water...

  14. 36 CFR 910.35 - Fine arts.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Fine arts. 910.35 Section 910... DEVELOPMENT AREA Standards Uniformly Applicable to the Development Area § 910.35 Fine arts. Fine arts... of art which are appropriate for the development. For information and guidance, a reasonable...

  15. 40 CFR 35.343 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... other resources; or (ii) Protection of natural resources by conservation. (b) Pollution prevention... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Definitions. 35.343 Section 35.343 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL...

  16. 36 CFR 230.35 - FLEP elements.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false FLEP elements. 230.35 Section... FORESTRY ASSISTANCE Forest Land Enhancement Program § 230.35 FLEP elements. (a) States may use FLEP funds... through the following elements: (1) Development and implementation of educational programs; (2) Resource...

  17. 50 CFR 35.9 - Livestock grazing.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Livestock grazing. 35.9 Section 35.9 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE..., reconstruction or relocation of only those livestock management improvements and structures which existed within...

  18. 21 CFR 73.35 - Astaxanthin.

    Science.gov (United States)

    2010-04-01

    ... safe for use in color additive mixtures for coloring foods. (b) Specifications. Astaxanthin shall... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Astaxanthin. 73.35 Section 73.35 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR...

  19. 48 CFR 35.013 - Insurance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Insurance. 35.013 Section... CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 35.013 Insurance. Nonprofit, educational, or State institutions performing cost-reimbursement contracts often do not carry insurance. They may claim immunity from...

  20. 40 CFR 35.6565 - Procurement methods.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Procurement methods. 35.6565 Section 35.6565 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...) Competitive proposals. The technique of competitive proposals is normally conducted with more than one source...

  1. 40 CFR 35.143 - Allotment.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Allotment. 35.143 Section 35.143 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL...) The Administrator may award funds on a competitive basis. ...

  2. 40 CFR 35.936-13 - Specifications.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Specifications. 35.936-13 Section 35.936-13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... which are readily available through competitive procurement, or through standard or proven production...

  3. 40 CFR 35.138 - Competitive grants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Competitive grants. 35.138 Section 35.138 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Competitive grants. (a) Some environmental program grants are awarded through a competitive process. An...

  4. 24 CFR 35.1335 - Standard treatments.

    Science.gov (United States)

    2010-04-01

    ... paint on exterior and interior surfaces located on the residential property shall be stabilized in accordance with § 35.1330(a)(b), or abated in accordance with § 35.1325. (b) Smooth and cleanable horizontal surfaces. All horizontal surfaces, such as uncarpeted floors, stairs, interior window sills and window...

  5. 12 CFR 1408.35 - Purpose.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Purpose. 1408.35 Section 1408.35 Banks and Banking FARM CREDIT SYSTEM INSURANCE CORPORATION COLLECTION OF CLAIMS OWED THE UNITED STATES Offset... salary offset published by the Office of Personnel Management, codified in 5 CFR part 550, subpart K...

  6. 24 CFR 35.1115 - Evaluation.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Evaluation. 35.1115 Section 35.1115 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD... Evaluation. (a) A lead-based paint inspection shall be conducted in all public housing unless a lead-based...

  7. 45 CFR 74.35 - Supplies.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Supplies. 74.35 Section 74.35 Public Welfare... Federal funds to provide services to non-Federal organizations for a fee that is less than private companies charge for equivalent services, unless specifically authorized by Federal statute as long as the...

  8. 38 CFR 21.35 - Definitions.

    Science.gov (United States)

    2010-07-01

    ...) VOCATIONAL REHABILITATION AND EDUCATION Vocational Rehabilitation and Employment Under 38 U.S.C. Chapter 31 Definitions § 21.35 Definitions. (a) Employment handicap. This term means an impairment of a veteran's ability... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Definitions. 21.35...

  9. Calcium Signaling Is Required for Erythroid Enucleation.

    Directory of Open Access Journals (Sweden)

    Christina B Wölwer

    Full Text Available Although erythroid enucleation, the property of erythroblasts to expel their nucleus, has been known for 7ore than a century, surprisingly little is known regarding the molecular mechanisms governing this unique developmental process. Here we show that similar to cytokinesis, nuclear extrusion requires intracellular calcium signaling and signal transduction through the calmodulin (CaM pathway. However, in contrast to cytokinesis we found that orthochromatic erythroblasts require uptake of extracellular calcium to enucleate. Together these functional studies highlight a critical role for calcium signaling in the regulation of erythroid enucleation.

  10. Coronary artery calcium score: current status

    Science.gov (United States)

    Neves, Priscilla Ornellas; Andrade, Joalbo; Monção, Henry

    2017-01-01

    The coronary artery calcium score plays an Important role In cardiovascular risk stratification, showing a significant association with the medium- or long-term occurrence of major cardiovascular events. Here, we discuss the following: protocols for the acquisition and quantification of the coronary artery calcium score by multidetector computed tomography; the role of the coronary artery calcium score in coronary risk stratification and its comparison with other clinical scores; its indications, interpretation, and prognosis in asymptomatic patients; and its use in patients who are symptomatic or have diabetes. PMID:28670030

  11. Contribution of presynaptic calcium-activated potassium currents to transmitter release regulation in cultured Xenopus nerve-muscle synapses.

    Science.gov (United States)

    Pattillo, J M; Yazejian, B; DiGregorio, D A; Vergara, J L; Grinnell, A D; Meriney, S D

    2001-01-01

    Using Xenopus nerve-muscle co-cultures, we have examined the contribution of calcium-activated potassium (K(Ca)) channels to the regulation of transmitter release evoked by single action potentials. The presynaptic varicosities that form on muscle cells in these cultures were studied directly using patch-clamp recording techniques. In these developing synapses, blockade of K(Ca) channels with iberiotoxin or charybdotoxin decreased transmitter release by an average of 35%. This effect would be expected to be caused by changes in the late phases of action potential repolarization. We hypothesize that these changes are due to a reduction in the driving force for calcium that is normally enhanced by the local hyperpolarization at the active zone caused by potassium current through the K(Ca) channels that co-localize with calcium channels. In support of this hypothesis, we have shown that when action potential waveforms were used as voltage-clamp commands to elicit calcium current in varicosities, peak calcium current was reduced only when these waveforms were broadened beginning when action potential repolarization was 20% complete. In contrast to peak calcium current, total calcium influx was consistently increased following action potential broadening. A model, based on previously reported properties of ion channels, faithfully reproduced predicted effects on action potential repolarization and calcium currents. From these data, we suggest that the large-conductance K(Ca) channels expressed at presynaptic varicosities regulate transmitter release magnitude during single action potentials by altering the rate of action potential repolarization, and thus the magnitude of peak calcium current.

  12. The Incredible, Embryological Egg: Calcium and Strontium Isotopes Recapitulate Ontogeny

    Science.gov (United States)

    Gordon, G. W.; Skulan, J. L.

    2011-12-01

    that caused by osteoporosis in humans. For both mass-dependent Ca and Sr isotopes, the isotopic value of the albumen is the highest natural value yet measured. The offset between the δ88/86Sr values of the albumen and shell is 0.45%, less than half that of the δ44/42Ca offset value (1.29%), as predicted by the relative mass differences. However, the yolk is 0.35% heavier than the shell in δ44/42Ca but 0.70% lighter in δ88/86Sr. In addition, the 87Sr/86Sr value of the shell (0.70854 ±0.000012, 2σ) is statistically the same as the albumen (0.70856 ±0.000018), but slightly offset from the yolk (0.70830 ±0.000014). The apparent decoupling of Ca and Sr, and the radiogenic offset between yolk and shell, may reflect differences in the residence time of calcium and strontium in different reproductive organs, as well as the contribution of medullary bone to shell formation. In addition, it may also reflect differential discrimination against Sr versus Ca in oviduct and uterus. Further studies could extend to thinning eggshells in wild avian populations, biochemical mechanisms of bone formation, and the mechanism of strontium ranelate in the treatment of osteoporosis.

  13. Structures of apicomplexan calcium-dependent protein kinases reveal mechanism of activation by calcium

    Energy Technology Data Exchange (ETDEWEB)

    Wernimont, Amy K; Artz, Jennifer D.; Jr, Patrick Finerty; Lin, Yu-Hui; Amani, Mehrnaz; Allali-Hassani, Abdellah; Senisterra, Guillermo; Vedadi, Masoud; Tempel, Wolfram; Mackenzie, Farrell; Chau, Irene; Lourido, Sebastian; Sibley, L. David; Hui, Raymond (Toronto); (WU-MED)

    2010-09-21

    Calcium-dependent protein kinases (CDPKs) have pivotal roles in the calcium-signaling pathway in plants, ciliates and apicomplexan parasites and comprise a calmodulin-dependent kinase (CaMK)-like kinase domain regulated by a calcium-binding domain in the C terminus. To understand this intramolecular mechanism of activation, we solved the structures of the autoinhibited (apo) and activated (calcium-bound) conformations of CDPKs from the apicomplexan parasites Toxoplasma gondii and Cryptosporidium parvum. In the apo form, the C-terminal CDPK activation domain (CAD) resembles a calmodulin protein with an unexpected long helix in the N terminus that inhibits the kinase domain in the same manner as CaMKII. Calcium binding triggers the reorganization of the CAD into a highly intricate fold, leading to its relocation around the base of the kinase domain to a site remote from the substrate binding site. This large conformational change constitutes a distinct mechanism in calcium signal-transduction pathways.

  14. Mesure de la bioaccessibilité du calcium en digestion in vitro : impact de la source calcique et de la structure (liquide ou gélifiée) d’une matrice alimentaire, contenant des protéines sériques.

    OpenAIRE

    Lorieau, Lucie; Le Roux, Linda; Gaucheron, Frederic; Ligneul, Amandine; Hazart, Etienne; Dupont, Didier; Floury, Juliane

    2016-01-01

    Discipline : Expérimental/mécanismes cellulaires et moléculaires Introduction et but de l’étude : Le calcium est un élément essentiel pour le développement et le maintien de la masse osseuse chez l’Homme. Pourtant, en France, seulement 40% des seniors ont un apport suffisant en calcium [1]. En moyenne, la biodisponibilité du calcium est de 35% et varie en fonction des sources de calcium [2] et de la composition de l’aliment. Ce protocole permet d'estimer la bioaccessibilité du calcium pouv...

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

    Science.gov (United States)

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

    2009-05-01

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

  16. Effects of Adding Chymosin to Milk on Calcium Homeostasis

    DEFF Research Database (Denmark)

    Møller, Ulla Kristine; Jensen, Lars Thorbjørn; Mosekilde, Leif

    2014-01-01

    either chymosin or similar placebo was added. Compared with placebo, chymosin did not affect 24-h urinary calcium, calcium/creatinine ratio, plasma parathyroid hormone, calcitonin or ionized calcium levels. However, during the first 4 h after intake of milk with chymosin, urinary calcium-creatinine ratio...

  17. Does calcium constrain reproductive activity in insectivorous bats ...

    African Journals Online (AJOL)

    Insects are a poor source of dietary calcium and since they are seasonally abundant, it has been suggested that calcium availability may play a significant role in controlling the timing of reproduction in insectivorous bats. To assess the possible role of dietary calcium, we have measured bone calcium concentrations in ...

  18. Model of intracellular calcium cycling in ventricular myocytes.

    Science.gov (United States)

    Shiferaw, Y; Watanabe, M A; Garfinkel, A; Weiss, J N; Karma, A

    2003-12-01

    We present a mathematical model of calcium cycling that takes into account the spatially localized nature of release events that correspond to experimentally observed calcium sparks. This model naturally incorporates graded release by making the rate at which calcium sparks are recruited proportional to the whole cell L-type calcium current, with the total release of calcium from the sarcoplasmic reticulum (SR) being just the sum of local releases. The dynamics of calcium cycling is studied by pacing the model with a clamped action potential waveform. Experimentally observed calcium alternans are obtained at high pacing rates. The results show that the underlying mechanism for this phenomenon is a steep nonlinear dependence of the calcium released from the SR on the diastolic SR calcium concentration (SR load) and/or the diastolic calcium level in the cytosol, where the dependence on diastolic calcium is due to calcium-induced inactivation of the L-type calcium current. In addition, the results reveal that the calcium dynamics can become chaotic even though the voltage pacing is periodic. We reduce the equations of the model to a two-dimensional discrete map that relates the SR and cytosolic concentrations at one beat and the previous beat. From this map, we obtain a condition for the onset of calcium alternans in terms of the slopes of the release-versus-SR load and release-versus-diastolic-calcium curves. From an analysis of this map, we also obtain an understanding of the origin of chaotic dynamics.

  19. Vitamin D with calcium reduces mortality

    DEFF Research Database (Denmark)

    Rejnmark, Lars; Avenell, Alison; Masud, Tahir

    2012-01-01

    Introduction:Vitamin D may affect multiple health outcomes. If so, an effect on mortality is to be expected. Using pooled data from randomized controlled trials, we performed individual patient data (IPD) and trial level meta-analyses to assess mortality among participants randomized to either...... calcium (odds ratio, 0.94; 95% CI, 0.88-0.99), but not with vitamin D alone (odds ratio, 0.98; 95% CI, 0.91-1.06).Conclusion:Vitamin D with calcium reduces mortality in the elderly, whereas available data do not support an effect of vitamin D alone....... vitamin D alone or vitamin D with calcium.Subjects and Methods:Through a systematic literature search, we identified 24 randomized controlled trials reporting data on mortality in which vitamin D was given either alone or with calcium. From a total of 13 trials with more than 1000 participants each, eight...

  20. Calcium Signaling and Cardiac Arrhythmias.

    Science.gov (United States)

    Landstrom, Andrew P; Dobrev, Dobromir; Wehrens, Xander H T

    2017-06-09

    There has been a significant progress in our understanding of the molecular mechanisms by which calcium (Ca2+) ions mediate various types of cardiac arrhythmias. A growing list of inherited gene defects can cause potentially lethal cardiac arrhythmia syndromes, including catecholaminergic polymorphic ventricular tachycardia, congenital long QT syndrome, and hypertrophic cardiomyopathy. In addition, acquired deficits of multiple Ca2+-handling proteins can contribute to the pathogenesis of arrhythmias in patients with various types of heart disease. In this review article, we will first review the key role of Ca2+ in normal cardiac function-in particular, excitation-contraction coupling and normal electric rhythms. The functional involvement of Ca2+ in distinct arrhythmia mechanisms will be discussed, followed by various inherited arrhythmia syndromes caused by mutations in Ca2+-handling proteins. Finally, we will discuss how changes in the expression of regulation of Ca2+ channels and transporters can cause acquired arrhythmias, and how these mechanisms might be targeted for therapeutic purposes. © 2017 American Heart Association, Inc.

  1. Morphological Investigation of Calcium Carbonate during Ammonification-Carbonization Process of Low Concentration Calcium Solution

    Directory of Open Access Journals (Sweden)

    Huaigang Cheng

    2014-01-01

    Full Text Available Ultrafine calcium carbonate is a widely used cheap additive. The research is conducted in low degree supersaturation solution in order to study the polymorphic phases’ change and its factors of the calcium carbonate precipitate in the ammonification-carbonization process of the solution with calcium. Fine particles of calcium carbonate are made in the solution containing 0.015 mol/L of Ca2+. Over 98% of the calcium carbonate precipitate without ammonification resembles the morphology of calcite, while the introduction of ammonia can benefit the formation of vaterite. It was inferred that the main cause should be serious partial oversaturation or steric effects. Ammonia also helps to form the twin spherical calcium carbonate. However, particles formed in the process of ammonification-carbonization in solution with low concentration degree of calcium are not even with a scale of the particle diameter from 5 to 12 μm. Inorganic salts, alcohol, or organic acid salts have significant controlling effect on the particle diameter of calcium carbonate and can help to decrease the particle diameter to about 3 μm. Anionic surfactants can prevent the conglobation of calcium carbonate particles and shrink its diameter to 500 nm–1 μm.

  2. Calcium-induced calcium release supports recruitment of synaptic vesicles in auditory hair cells.

    Science.gov (United States)

    Castellano-Muñoz, Manuel; Schnee, Michael E; Ricci, Anthony J

    2016-01-01

    Hair cells from auditory and vestibular systems transmit continuous sound and balance information to the central nervous system through the release of synaptic vesicles at ribbon synapses. The high activity experienced by hair cells requires a unique mechanism to sustain recruitment and replenishment of synaptic vesicles for continuous release. Using pre- and postsynaptic electrophysiological recordings, we explored the potential contribution of calcium-induced calcium release (CICR) in modulating the recruitment of vesicles to auditory hair cell ribbon synapses. Pharmacological manipulation of CICR with agents targeting endoplasmic reticulum calcium stores reduced both spontaneous postsynaptic multiunit activity and the frequency of excitatory postsynaptic currents (EPSCs). Pharmacological treatments had no effect on hair cell resting potential or activation curves for calcium and potassium channels. However, these drugs exerted a reduction in vesicle release measured by dual-sine capacitance methods. In addition, calcium substitution by barium reduced release efficacy by delaying release onset and diminishing vesicle recruitment. Together these results demonstrate a role for calcium stores in hair cell ribbon synaptic transmission and suggest a novel contribution of CICR in hair cell vesicle recruitment. We hypothesize that calcium entry via calcium channels is tightly regulated to control timing of vesicle fusion at the synapse, whereas CICR is used to maintain a tonic calcium signal to modulate vesicle trafficking. Copyright © 2016 the American Physiological Society.

  3. Fractal aspects of calcium binding protein structures

    Energy Technology Data Exchange (ETDEWEB)

    Isvoran, Adriana [West University of Timisoara, Department of Chemistry, Pestalozzi 16, 300115 Timisoara (Romania)], E-mail: aisvoran@cbg.uvt.ro; Pitulice, Laura [West University of Timisoara, Department of Chemistry, Pestalozzi 16, 300115 Timisoara (Romania); Craescu, Constantin T. [INSERM U759/Institute Curie-Recherche, Centre Universitaire Paris-Sud, Batiment 112, 91405 Orsay (France); Chiriac, Adrian [West University of Timisoara, Department of Chemistry, Pestalozzi 16, 300115 Timisoara (Romania)

    2008-03-15

    The structures of EF-hand calcium binding proteins may be classified into two distinct groups: extended and compact structures. In this paper we studied 20 different structures of calcium binding proteins using the fractal analysis. Nine structures show extended shapes, one is semi-compact and the other 10 have compact shapes. Our study reveals different fractal characteristics for protein backbones belonging to different structural classes and these observations may be correlated to the physicochemical forces governing the protein folding.

  4. Understanding calcium dynamics experiments and theory

    CERN Document Server

    Malchow, Dieter

    2003-01-01

    Intracellular Calcium is an important messenger in living cells. Calcium dynamics display complex temporal and spatial structures created by the concentration patterns which are characteristic for a nonlinear system operating far from thermodynamic equilibrium. Written as a set of tutorial reviews on both experimental facts and theoretical modelling, this volume is intended as an introduction and modern reference in the field for graduate students and researchers in biophysics, biochemistry and applied mathematics.

  5. Analytical models of calcium binding in a calcium channel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jinn-Liang [Department of Applied Mathematics, National Hsinchu University of Education, Hsinchu 300, Taiwan (China); Eisenberg, Bob [Department of Molecular Biophysics and Physiology, Rush University, Chicago, Illinois 60612 (United States)

    2014-08-21

    The anomalous mole fraction effect of L-type calcium channels is analyzed using a Fermi like distribution with the experimental data of Almers and McCleskey [J. Physiol. 353, 585 (1984)] and the atomic resolution model of Lipkind and Fozzard [Biochemistry 40, 6786 (2001)] of the selectivity filter of the channel. Much of the analysis is algebraic, independent of differential equations. The Fermi distribution is derived from the configuration entropy of ions and water molecules with different sizes, different valences, and interstitial voids between particles. It allows us to calculate potentials and distances (between the binding ion and the oxygen ions of the glutamate side chains) directly from the experimental data using algebraic formulas. The spatial resolution of these results is comparable with those of molecular models, but of course the accuracy is no better than that implied by the experimental data. The glutamate side chains in our model are flexible enough to accommodate different types of binding ions in different bath conditions. The binding curves of Na{sup +} and Ca{sup 2+} for [CaCl{sub 2}] ranging from 10{sup −8} to 10{sup −2} M with a fixed 32 mM background [NaCl] are shown to agree with published Monte Carlo simulations. The Poisson-Fermi differential equation—that includes both steric and correlation effects—is then used to obtain the spatial profiles of energy, concentration, and dielectric coefficient from the solvent region to the filter. The energy profiles of ions are shown to depend sensitively on the steric energy that is not taken into account in the classical rate theory. We improve the rate theory by introducing a steric energy that lumps the effects of excluded volumes of all ions and water molecules and empty spaces between particles created by Lennard-Jones type and electrostatic forces. We show that the energy landscape varies significantly with bath concentrations. The energy landscape is not constant.

  6. Contribution of calcium oxalate to soil-exchangeable calcium

    Science.gov (United States)

    Dauer, Jenny M.; Perakis, Steven S.

    2013-01-01

    Acid deposition and repeated biomass harvest have decreased soil calcium (Ca) availability in many temperate forests worldwide, yet existing methods for assessing available soil Ca do not fully characterize soil Ca forms. To account for discrepancies in ecosystem Ca budgets, it has been hypothesized that the highly insoluble biomineral Ca oxalate might represent an additional soil Ca pool that is not detected in standard measures of soil-exchangeable Ca. We asked whether several standard method extractants for soil-exchangeable Ca could also access Ca held in Ca oxalate crystals using spike recovery tests in both pure solutions and soil extractions. In solutions of the extractants ammonium chloride, ammonium acetate, and barium chloride, we observed 2% to 104% dissolution of Ca oxalate crystals, with dissolution increasing with both solution molarity and ionic potential of cation extractant. In spike recovery tests using a low-Ca soil, we estimate that 1 M ammonium acetate extraction dissolved sufficient Ca oxalate to contribute an additional 52% to standard measurements of soil-exchangeable Ca. However, in a high-Ca soil, the amount of Ca oxalate spike that would dissolve in 1 M ammonium acetate extraction was difficult to detect against the large pool of exchangeable Ca. We conclude that Ca oxalate can contribute substantially to standard estimates of soil-exchangeable Ca in acid forest soils with low soil-exchangeable Ca. Consequently, measures of exchangeable Ca are unlikely to fully resolve discrepancies in ecosystem Ca mass balance unless the contribution of Ca oxalate to exchangeable Ca is also assessed.

  7. Self-Setting Calcium Orthophosphate Formulations

    Science.gov (United States)

    Dorozhkin, Sergey V.

    2013-01-01

    In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are bioactive and biodegradable grafting bioceramics in the form of a powder and a liquid. After mixing, both phases form pastes, which set and harden forming either a non-stoichiometric calcium deficient hydroxyapatite or brushite. Since both of them are remarkably biocompartible, bioresorbable and osteoconductive, self-setting calcium orthophosphate formulations appear to be promising bioceramics for bone grafting. Furthermore, such formulations possess excellent molding capabilities, easy manipulation and nearly perfect adaptation to the complex shapes of bone defects, followed by gradual bioresorption and new bone formation. In addition, reinforced formulations have been introduced, which might be described as calcium orthophosphate concretes. The discovery of self-setting properties opened up a new era in the medical application of calcium orthophosphates and many commercial trademarks have been introduced as a result. Currently such formulations are widely used as synthetic bone grafts, with several advantages, such as pourability and injectability. Moreover, their low-temperature setting reactions and intrinsic porosity allow loading by drugs, biomolecules and even cells for tissue engineering purposes. In this review, an insight into the self-setting calcium orthophosphate formulations, as excellent bioceramics suitable for both dental and bone grafting applications, has been provided. PMID:24956191

  8. Calcium signaling in human pluripotent stem cells.

    Science.gov (United States)

    Apáti, Ágota; Berecz, Tünde; Sarkadi, Balázs

    2016-03-01

    Human pluripotent stem cells provide new tools for developmental and pharmacological studies as well as for regenerative medicine applications. Calcium homeostasis and ligand-dependent calcium signaling are key components of major cellular responses, including cell proliferation, differentiation or apoptosis. Interestingly, these phenomena have not been characterized in detail as yet in pluripotent human cell sates. Here we review the methods applicable for studying both short- and long-term calcium responses, focusing on the expression of fluorescent calcium indicator proteins and imaging methods as applied in pluripotent human stem cells. We discuss the potential regulatory pathways involving calcium responses in hPS cells and compare these to the implicated pathways in mouse PS cells. A recent development in the stem cell field is the recognition of so called "naïve" states, resembling the earliest potential forms of stem cells during development, as well as the "fuzzy" stem cells, which may be alternative forms of pluripotent cell types, therefore we also discuss the potential role of calcium homeostasis in these PS cell types. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. High speed two-photon imaging of calcium dynamics in dendritic spines: consequences for spine calcium kinetics and buffer capacity

    NARCIS (Netherlands)

    Cornelisse, L.N.; van Elburg, R.A.J.; Meredith, R.M.; Yuste, R.; Mansvelder, H.D.

    2007-01-01

    Rapid calcium concentration changes in postsynaptic structures are crucial for synaptic plasticity. Thus far, the determinants of postsynaptic calcium dynamics have been studied predominantly based on the decay kinetics of calcium transients. Calcium rise times in spines in response to single action

  10. High Speed Two-Photon Imaging of Calcium Dynamics in Dendritic Spines: : Consequences for Spine Calcium Kinetics and Buffer Capacity

    NARCIS (Netherlands)

    van Elburg, R.A.J.; Cornelisse, L.N; Meredith, R.M; Yuste, R; Mansvelder, H.D

    2007-01-01

    Rapid calcium concentration changes in postsynaptic structures are crucial for synaptic plasticity. Thus far, the determinants of postsynaptic calcium dynamics have been studied predominantly based on the decay kinetics of calcium transients. Calcium rise times in spines in response to single action

  11. Oral calcium carbonate affects calcium but not phosphorus balance in stage 3-4 chronic kidney disease.

    Science.gov (United States)

    Hill, Kathleen M; Martin, Berdine R; Wastney, Meryl E; McCabe, George P; Moe, Sharon M; Weaver, Connie M; Peacock, Munro

    2013-05-01

    Patients with chronic kidney disease (CKD) are given calcium carbonate to bind dietary phosphorus, reduce phosphorus retention, and prevent negative calcium balance; however, data are limited on calcium and phosphorus balance during CKD to support this. Here, we studied eight patients with stage 3 or 4 CKD (mean estimated glomerular filtration rate 36 ml/min) who received a controlled diet with or without a calcium carbonate supplement (1500 mg/day calcium) during two 3-week balance periods in a randomized placebo-controlled cross-over design. All feces and urine were collected during weeks 2 and 3 of each balance period and fasting blood, and urine was collected at baseline and at the end of each week. Calcium kinetics were determined using oral and intravenous (45)calcium. Patients were found to be in neutral calcium and phosphorus balance while on the placebo. Calcium carbonate supplementation produced positive calcium balance, did not affect phosphorus balance, and produced only a modest reduction in urine phosphorus excretion compared with placebo. Calcium kinetics demonstrated positive net bone balance but less than overall calcium balance, suggesting soft-tissue deposition. Fasting blood and urine biochemistries of calcium and phosphate homeostasis were unaffected by calcium carbonate. Thus, the positive calcium balance produced by calcium carbonate treatment within 3 weeks cautions against its use as a phosphate binder in patients with stage 3 or 4 CKD, if these findings can be extrapolated to long-term therapy.

  12. Effect of calcium hydroxide on ph changes of the external medium after intracoronal bleaching.

    Science.gov (United States)

    Sa, Patricia Marra de; Jeronymo, Raffaela Di Iorio; Yui, Karen Cristina Kazue; Silva, Eduardo Galera da; Huhtala, Maria Filomena Rocha Lima; Torres, Carlos Rocha Gomes; Gomes, Ana Paula Martins

    2011-05-01

    This in vitro study evaluated the effect of calcium hydroxide on pH changes of the external medium after intracoronal bleaching. A total of 50 extracted human premolars were prepared and filled with gutta-percha and endodontic sealer. The teeth were randomly divided into five groups according to the bleaching agents employed: (a) Sterile cotton pellet with distilled water (control group); (b) sodium perborate and distilled water; (c) sodium perborate and 10% carbamide peroxide; (d) sodium perborate and 35% hydrogen peroxide; (e) 35% hydrogen peroxide. The teeth were stored in vials containing distilled water and the pH values of the medium surrounding the teeth were analyzed. After 7-day storage, the bleaching agent was removed and replaced by calcium hydroxide, and the distilled water was changed, in which the teeth were kept stored for further 14 days. Measurement of pH of the external medium (distilled water) was performed 7 days after insertion of the bleaching agents, immediately, 7 and 14 days after insertion of the calcium hydroxide. Data were submitted to statistical analysis by the two-way ANOVA and Tukey,s test. There were pH changes of the external medium at 7- day period after bleaching procedures. These results confirmed the diffusion of bleaching agents to the external medium. Calcium hydroxide increased the external medium pH and was effective for pH alkalinization after intracoronal bleaching. Intracoronal bleaching of endodontically treated teeth may cause cervical root resorption. A possible explanation for this process is the passage of bleaching agents to the periodontal tissues yielding an inflammatory process. In an attempt to keep the neutrality of the periodontal pH, the calcium hydroxide has been recommended.Results of this study showed that this material should be always used after intracoronal bleaching.

  13. The influence of environmental calcium concentrations on calcium flux, compensatory drinking and epithelial calcium channel expression in a freshwater cartilaginous fish.

    Science.gov (United States)

    Allen, Peter J; Weihrauch, Dirk; Grandmaison, Vanessa; Dasiewicz, Patricia; Peake, Stephan J; Anderson, W Gary

    2011-03-15

    Calcium metabolism and mRNA levels of the epithelial calcium channel (ECaC) were examined in a freshwater cartilaginous fish, the lake sturgeon Acipenser fulvescens. Lake sturgeon were acclimated for ≥2 weeks to 0.1 (low), 0.4 (normal) or 3.3 (high) mmol l(-1) environmental calcium. Whole-body calcium flux was examined using (45)Ca as a radioactive marker. Net calcium flux was inward in all treatment groups; however, calcium influx was greatest in the low calcium environment and lowest in the high calcium environment, whereas efflux had the opposite relationship. A significant difference in the concentration of (45)Ca in the gastrointestinal tract (GIT) of fish in the low calcium environment led to the examination of drinking rate and calcium flux across the anterior-middle (mid) intestine. Drinking rate was not different between treatments; however, calcium influx across the mid-intestine in the low calcium treatment was significantly greater than that in both the normal and high calcium treatments. The lake sturgeon ECaC was 2831 bp in length, with a predicted protein sequence of 683 amino acids that shared a 66% identity with the closest sequenced ECaCs from the vertebrate phyla. ECaC mRNA levels were examined in the gills, kidney, pyloric caeca, mid-intestine and spiral intestine. Expression levels were highest in the gills, then the kidneys, and were orders of magnitude lower in the GIT. Contrary to existing models for calcium uptake in the teleost gill, ECaC expression was greatest in high calcium conditions and kidney ECaC expression was lowest in low calcium conditions, suggesting that cellular transport mechanisms for calcium may be distinctly different in these freshwater cartilaginous fishes.

  14. Magnetometer Data recovered from 35mm film

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The L57 CDMP recovery project takes magnetometer data on 35mm film stored at the archive's climate controlled warehouse and digitizes them.

  15. 40 CFR 35.3170 - Corrective action.

    Science.gov (United States)

    2010-07-01

    ... STATE AND LOCAL ASSISTANCE State Water Pollution Control Revolving Funds § 35.3170 Corrective action. (a) Causes. If the RA determines that the State has not complied with requirements under title VI, the RA...

  16. 40 CFR 35.3155 - Payments.

    Science.gov (United States)

    2010-07-01

    ... ASSISTANCE State Water Pollution Control Revolving Funds § 35.3155 Payments. (a) Payment schedule. The State... VI of the Act. The State may draw cash for these incurred pre-building costs immediately upon...

  17. 40 CFR 35.4270 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... ASSISTANCE Grants for Technical Assistance Other Things You Need to Know § 35.4270 Definitions. The following... country's national response capability and promotes overall coordination among the hierarchy of responders...

  18. 40 CFR 35.970 - Contract enforcement.

    Science.gov (United States)

    2010-07-01

    ... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.970 Contract... technical or legal involvement in any contract dispute will not make EPA a party to any contract entered...

  19. Acute effects of calcium carbonate, calcium citrate and potassium citrate on markers of calcium and bone metabolism in young women.

    Science.gov (United States)

    Karp, Heini J; Ketola, Maarit E; Lamberg-Allardt, Christel J E

    2009-11-01

    Both K and Ca supplementation may have beneficial effects on bone through separate mechanisms. K in the form of citrate or bicarbonate affects bone by neutralising the acid load caused by a high protein intake or a low intake of alkalising foods, i.e. fruits and vegetables. Ca is known to decrease serum parathyroid hormone (S-PTH) concentration and bone resorption. We compared the effects of calcium carbonate, calcium citrate and potassium citrate on markers of Ca and bone metabolism in young women. Twelve healthy women aged 22-30 years were randomised into four controlled 24 h study sessions, each subject serving as her own control. At the beginning of each session, subjects received a single dose of calcium carbonate, calcium citrate, potassium citrate or a placebo in randomised order. The diet during each session was identical, containing 300 mg Ca. Both the calcium carbonate and calcium citrate supplement contained 1000 mg Ca; the potassium citrate supplement contained 2250 mg K. Markers of Ca and bone metabolism were followed. Potassium citrate decreased the bone resorption marker (N-terminal telopeptide of type I collagen) and increased Ca retention relative to the control session. Both Ca supplements decreased S-PTH concentration. Ca supplements also decreased bone resorption relative to the control session, but this was significant only for calcium carbonate. No differences in bone formation marker (bone-specific alkaline phosphatase) were seen among the study sessions. The results suggest that potassium citrate has a positive effect on the resorption marker despite low Ca intake. Both Ca supplements were absorbed well and decreased S-PTH efficiently.

  20. 27 CFR 9.35 - Edna Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Edna Valley. 9.35 Section 9.35 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... identified as “T31S/T32S” on the U.S.G.S. map; (4) Thence east along township line “T31S/T32S”, across Price...

  1. Effects of the application sequence of calcium-containing desensitising pastes during etch-and-rinse adhesive restoration.

    Science.gov (United States)

    Yang, Hongye; Pei, Dandan; Chen, Zhiyong; Lei, Jinmei; Zhou, Liqun; Huang, Cui

    2014-09-01

    To evaluate the effects of different application sequence of calcium-containing desensitising pastes on bonding effectiveness and tubule occlusion during etch-and-rinse (E&R) adhesive restoration. Seventy molars were sectioned parallel to the occlusal plane, polished and randomly divided into seven groups (n=10). Group 1 was etched with 35% phosphoric acid for 15s. Groups 2-4 were treated with different calcium-containing desensitisers, including an arginine-calcium carbonate (Arg-CaCO3)-containing paste, a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-containing paste and a calcium-sodium phosphosilicate (Novamin)-containing paste, respectively. Afterward, these groups were etched with 35% phosphoric acid for 15s. Groups 5-7 were initially etched and then treated with Arg-CaCO3-, CPP-ACP- and Novamin-containing desensitisers, respectively. In each group, samples were equally distributed into two subgroups (n=5) to bond with either a two-step E&R adhesive Adper SingleBond 2 (SB) or a three-step E&R adhesive Adper ScotchBond Multi-Purpose (SBMP). The microtensile bond strengths (MTBS) were tested and fracture modes were analyzed by stereomicroscopy and field-emission scanning electron microscopy (FESEM). Eight additional dentine disks were prepared to evaluate tubule occlusion prior to bonding using FESEM. The application sequence of calcium-containing desensitising pastes did not significantly affect MTBS irrespective of two-step SB (P>0.05) or three-step SBMP E&R adhesives (P>0.05). Effective dentinal tubule occlusion was observed in the mode of etching-desensitising. Applying calcium-containing desensitisers (particularly Arg-CaCO3- and Novamin-based) after etching during E&R adhesive restoration could achieve effective tubule occlusion without affecting the bonding strength. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. A randomized, double-blind, placebo-controlled, clinical study on the efficacy and safety of calcium dobesilate in the treatment of chronic venous insufficiency.

    Science.gov (United States)

    Rabe, Eberhard; Ballarini, Stefania; Lehr, Lorenz

    2016-05-01

    To show the superiority of 500 mg calcium dobesilate vs. placebo in reduction of edema of the lower limbs in patients with chronic venous insufficiency, Clinical, Etiological, Anatomical and Pathophysiological classes C3/C4. A total of 351 patients were randomized (n = 174 calcium dobesilate, n = 177 placebo). Active treatment was 500 mg calcium dobesilate, three times daily for 12 weeks, with a 12-week follow-up. At the end of treatment, the relative volume change in the most pathological leg was -0.6 ± 4.8% with calcium dobesilate compared to -0.3 ± 3.3% with placebo (p = 0.09). At the end of follow-up, this was -1.01 ± 5.4% for calcium dobesilate vs. -0.08 ± 3.5% for placebo (p = 0.002). Calcium dobesilate treatment resulted in no significant volume change in the most pathological leg between baseline and end of treatment. However, the calcium dobesilate group showed a significantly greater volume decrease in the most pathological leg at the end of follow-up. Calcium dobesilate was well-tolerated, with a safety profile consistent with previously published data. © The Author(s) 2015.

  3. Y1 receptors for neuropeptide Y are coupled to mobilization of intracellular calcium and inhibition of adenylate cyclase

    DEFF Research Database (Denmark)

    Aakerlund, L; Gether, U; Fuhlendorff, J

    1990-01-01

    a rapid and transient increase in the concentration of free calcium in the cytoplasm as measured by the fluorescent probe, Fura-2. The effect of both peptides was independent of extracellular calcium as addition of EGTA or manganese neither changed the size nor the shape of the calcium response....... The calcium response to NPY was abolished by pretreatment with thapsigargin, which can selectively deplete a calcium store in the endoplasmic reticulum. Y1 receptor stimulation, by both NPY and [Leu31,Pro34]NPY, also inhibited the forskolin-stimulated cAMP production with an EC50 of 3.5 nM. There was a close...... relation between the receptor binding and the cellular effects as half-maximal displacement of [125I-Tyr36]monoiodoNPY from the receptor was obtained with 2.1 nM NPY. The Y2-specific ligand NPY(16-36)peptide had no effect on either intracellular calcium or cAMP levels in the SK-N-MC cells. It is concluded...

  4. PTHrP regulation and calcium balance in sea bream (Sparus auratus L.) under calcium constraint

    NARCIS (Netherlands)

    Abbink, W.; Bevelander, G.S.; Hang, X.; Lu, W.; Guerreiro, P.M.; Spanings, T.; Canario, A.V.; Flik, G.

    2006-01-01

    Juvenile gilthead sea bream were exposed to diluted seawater (2.5 per thousand salinity; DSW) for 3 h or, in a second experiment, acclimated to DSW and fed a control or calcium-deficient diet for 30 days. Branchial Ca(2+) influx, drinking rate and plasma calcium levels were assessed. Sea bream

  5. Calcium spikes and calcium plateaux evoked by differential polarization in dendrites of turtle motoneurones in vitro

    DEFF Research Database (Denmark)

    Hounsgaard, J; Kiehn, O

    1993-01-01

    The ability of dendrites in turtle motoneurones to support calcium spikes and calcium plateaux was investigated using differential polarization by applied electric fields. 2. Electric fields were generated by passing current through transverse slices of the turtle spinal cord between two plate......+ spikes and Ca2+ plateaux are present in dendrites of spinal motoneurones of the turtle....

  6. Eggshell powder, a comparable or better source of calcium than purified calcium carbonate: Piglet studies

    NARCIS (Netherlands)

    Schaafsma, A.; Beelen, G.M.

    1999-01-01

    Powdered chicken eggshells might be an interesting and widely available source of calcium. In two studies using piglets we determined the digestibility of calcium from different diets. The first study compared casein-based diets with CaCO3 (CasCC) or eggshell powder (CasES). The second study

  7. Calcium response to vitamin D supplementation

    Directory of Open Access Journals (Sweden)

    Francisco R. Spivacow

    2018-01-01

    Full Text Available Several studies show the importance of serum vitamin D sufficient levels to prevent multiple chronic diseases. However, vitamin D supplementation and its effects on urine calcium excretion remain controversial. The objective of this prospective and interventional study was to evaluate urine calcium excretion in women with normal calciuria or hypercalciuria, once serum vitamin D sufficiency was achieved. We studied 63 women with idiopathic hypercalciuria, (9 with renal lithiasis and 50 normocalciuric women. Both groups had serum vitamin D levels low (deficiency or insufficiency. Baseline urine calcium excretion was measured before being supplemented with vitamin D2 or D3 weekly or vitamin D3 100.000 IU monthly. Once serum vitamin D levels were corrected achieving at least 30 ng/ml, a second urine calcium excretion was obtained. Although in the whole sample we did not observe significant changes in urine calcium excretion according to the way of supplementation, some of those with weekly supplementation had significant higher urine calcium excretion, 19% (n = 12 of hypercalciuric women and 12% (n = 6 of the normocalciuric group. Monthly doses, also showed higher urine calcium excretion in 40% of hypercalciuric women (n = 4/10 and in 44% (n = 4/9 of the renal lithiasis hypercalciuric patients. In conclusion, different ways of vitamin D supplementation and adequate serum levels are safe in most patients, although it should be taken into account a subgroup, mainly with monthly loading doses, that could increase the calciuria significantly eventually rising renal lithiasis risk or bone mass loss, if genetically predisposed.

  8. Calcium carbonate polyamorphism and its role in biomineralization: how many amorphous calcium carbonates are there?

    Science.gov (United States)

    Cartwright, Julyan H E; Checa, Antonio G; Gale, Julian D; Gebauer, Denis; Sainz-Díaz, C Ignacio

    2012-11-26

    Although the polymorphism of calcium carbonate is well known, and its polymorphs--calcite, aragonite, and vaterite--have been highly studied in the context of biomineralization, polyamorphism is a much more recently discovered phenomenon, and the existence of more than one amorphous phase of calcium carbonate in biominerals has only very recently been understood. Here we summarize what is known about polyamorphism in calcium carbonate as well as what is understood about the role of amorphous calcium carbonate in biominerals. We show that consideration of the amorphous forms of calcium carbonate within the physical notion of polyamorphism leads to new insights when it comes to the mechanisms by which polymorphic structures can evolve in the first place. This not only has implications for our understanding of biomineralization, but also of the means by which crystallization may be controlled in medical, pharmaceutical, and industrial contexts. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Serum calcium levels are associated with novel cardiometabolic risk factors in the population-based CoLaus study.

    Directory of Open Access Journals (Sweden)

    Idris Guessous

    Full Text Available BACKGROUND: Associations of serum calcium levels with the metabolic syndrome and other novel cardio-metabolic risk factors not classically included in the metabolic syndrome, such as those involved in oxidative stress, are largely unexplored. We analyzed the association of albumin-corrected serum calcium levels with conventional and non-conventional cardio-metabolic risk factors in a general adult population. METHODOLOGY/PRINCIPAL FINDINGS: The CoLaus study is a population-based study including Caucasians from Lausanne, Switzerland. The metabolic syndrome was defined using the Adult Treatment Panel III criteria. Non-conventional cardio-metabolic risk factors considered included: fat mass, leptin, LDL particle size, apolipoprotein B, fasting insulin, adiponectin, ultrasensitive CRP, serum uric acid, homocysteine, and gamma-glutamyltransferase. We used adjusted standardized multivariable regression to compare the association of each cardio-metabolic risk factor with albumin-corrected serum calcium. We assessed associations of albumin-corrected serum calcium with the cumulative number of non-conventional cardio-metabolic risk factors. We analyzed 4,231 subjects aged 35 to 75 years. Corrected serum calcium increased with both the number of the metabolic syndrome components and the number of non-conventional cardio-metabolic risk factors, independently of the metabolic syndrome and BMI. Among conventional and non-conventional cardio-metabolic risk factors, the strongest positive associations were found for factors related to oxidative stress (uric acid, homocysteine and gamma-glutamyltransferase. Adiponectin had the strongest negative association with corrected serum calcium. CONCLUSIONS/SIGNIFICANCE: Serum calcium was associated with the metabolic syndrome and with non-conventional cardio-metabolic risk factors independently of the metabolic syndrome. Associations with uric acid, homocysteine and gamma-glutamyltransferase were the strongest. These

  10. Calcium-Induced calcium release during action potential firing in developing inner hair cells.

    Science.gov (United States)

    Iosub, Radu; Avitabile, Daniele; Grant, Lisa; Tsaneva-Atanasova, Krasimira; Kennedy, Helen J

    2015-03-10

    In the mature auditory system, inner hair cells (IHCs) convert sound-induced vibrations into electrical signals that are relayed to the central nervous system via auditory afferents. Before the cochlea can respond to normal sound levels, developing IHCs fire calcium-based action potentials that disappear close to the onset of hearing. Action potential firing triggers transmitter release from the immature IHC that in turn generates experience-independent firing in auditory neurons. These early signaling events are thought to be essential for the organization and development of the auditory system and hair cells. A critical component of the action potential is the rise in intracellular calcium that activates both small conductance potassium channels essential during membrane repolarization, and triggers transmitter release from the cell. Whether this calcium signal is generated by calcium influx or requires calcium-induced calcium release (CICR) is not yet known. IHCs can generate CICR, but to date its physiological role has remained unclear. Here, we used high and low concentrations of ryanodine to block or enhance CICR to determine whether calcium release from intracellular stores affected action potential waveform, interspike interval, or changes in membrane capacitance during development of mouse IHCs. Blocking CICR resulted in mixed action potential waveforms with both brief and prolonged oscillations in membrane potential and intracellular calcium. This mixed behavior is captured well by our mathematical model of IHC electrical activity. We perform two-parameter bifurcation analysis of the model that predicts the dependence of IHCs firing patterns on the level of activation of two parameters, the SK2 channels activation and CICR rate. Our data show that CICR forms an important component of the calcium signal that shapes action potentials and regulates firing patterns, but is not involved directly in triggering exocytosis. These data provide important insights

  11. Discovery and Development of Calcium Channel Blockers

    Directory of Open Access Journals (Sweden)

    Théophile Godfraind

    2017-05-01

    Full Text Available In the mid 1960s, experimental work on molecules under screening as coronary dilators allowed the discovery of the mechanism of calcium entry blockade by drugs later named calcium channel blockers. This paper summarizes scientific research on these small molecules interacting directly with L-type voltage-operated calcium channels. It also reports on experimental approaches translated into understanding of their therapeutic actions. The importance of calcium in muscle contraction was discovered by Sidney Ringer who reported this fact in 1883. Interest in the intracellular role of calcium arose 60 years later out of Kamada (Japan and Heibrunn (USA experiments in the early 1940s. Studies on pharmacology of calcium function were initiated in the mid 1960s and their therapeutic applications globally occurred in the the 1980s. The first part of this report deals with basic pharmacology in the cardiovascular system particularly in isolated arteries. In the section entitled from calcium antagonists to calcium channel blockers, it is recalled that drugs of a series of diphenylpiperazines screened in vivo on coronary bed precontracted by angiotensin were initially named calcium antagonists on the basis of their effect in depolarized arteries contracted by calcium. Studies on arteries contracted by catecholamines showed that the vasorelaxation resulted from blockade of calcium entry. Radiochemical and electrophysiological studies performed with dihydropyridines allowed their cellular targets to be identified with L-type voltage-operated calcium channels. The modulated receptor theory helped the understanding of their variation in affinity dependent on arterial cell membrane potential and promoted the terminology calcium channel blocker (CCB of which the various chemical families are introduced in the paper. In the section entitled tissue selectivity of CCBs, it is shown that characteristics of the drug, properties of the tissue, and of the stimuli are

  12. Store-operated calcium entry and increased endothelial cell permeability.

    Science.gov (United States)

    Norwood, N; Moore, T M; Dean, D A; Bhattacharjee, R; Li, M; Stevens, T

    2000-11-01

    We hypothesized that myosin light chain kinase (MLCK) links calcium release to activation of store-operated calcium entry, which is important for control of the endothelial cell barrier. Acute inhibition of MLCK caused calcium release from inositol trisphosphate-sensitive calcium stores and prevented subsequent activation of store-operated calcium entry by thapsigargin, suggesting that MLCK serves as an important mechanism linking store depletion to activation of membrane calcium channels. Moreover, in voltage-clamped single rat pulmonary artery endothelial cells, thapsigargin activated an inward calcium current that was abolished by MLCK inhibition. F-actin disruption activated a calcium current, and F-actin stabilization eliminated the thapsigargin-induced current. Thapsigargin increased endothelial cell permeability in the presence, but not in the absence, of extracellular calcium, indicating the importance of calcium entry in decreasing barrier function. Although MLCK inhibition prevented thapsigargin from stimulating calcium entry, it did not prevent thapsigargin from increasing permeability. Rather, inhibition of MLCK activity increased permeability that was especially prominent in low extracellular calcium. In conclusion, MLCK links store depletion to activation of a store-operated calcium entry channel. However, inhibition of calcium entry by MLCK is not sufficient to prevent thapsigargin from increasing endothelial cell permeability.

  13. The spatial pattern of atrial cardiomyocyte calcium signalling modulates contraction.

    Science.gov (United States)

    Mackenzie, Lauren; Roderick, H Llewelyn; Berridge, Michael J; Conway, Stuart J; Bootman, Martin D

    2004-12-15

    We examined the regulation of calcium signalling in atrial cardiomyocytes during excitation-contraction coupling, and how changes in the distribution of calcium impacts on contractility. Under control conditions, calcium transients originated in subsarcolemmal locations and showed local regeneration through activation of calcium-induced calcium release from ryanodine receptors. Despite functional ryanodine receptors being expressed at regular (approximately 2 microm) intervals throughout atrial myocytes, the subsarcolemmal calcium signal did not spread in a fully regenerative manner through the interior of a cell. Rather, there was a diminishing centripetal propagation of calcium. The lack of regeneration was due to mitochondria and SERCA pumps preventing the inward movement of calcium. Inhibiting these calcium buffering mechanisms allowed the globalisation of action potential-evoked responses. In addition, physiological positive inotropic agents, such as endothelin-1 and beta-adrenergic agonists, as well as enhanced calcium current, calcium store loading and inositol 1,4,5-trisphosphate infusion also led to regenerative global responses. The consequence of globalising calcium signals was a significant increase in cellular contraction. These data indicate how calcium signals and their consequences are determined by the interplay of multiple subcellular calcium management systems.

  14. Calcium Aluminate Cement Hydration Model

    Directory of Open Access Journals (Sweden)

    Matusinović, T.

    2011-01-01

    Full Text Available Calcium aluminate cement (AC is a very versatile special cement used for specific applications. As the hydration of AC is highly temperature dependent, yielding structurally different hydration products that continuously alter material properties, a good knowledge of thermal properties at early stages of hydration is essential. The kinetics of AC hydration is a complex process and the use of single mechanisms models cannot describe the rate of hydration during the whole stage.This paper examines the influence of temperature (ϑ=5–20 °C and water-to-cement mass ratio (mH /mAC = 0.4; 0.5 and 1.0 on hydration of commercial iron-rich AC ISTRA 40 (producer: Istra Cement, Pula, Croatia, which is a part of CALUCEM group, Figs 1–3. The flow rate of heat generation of cement pastes as a result of the hydration reactions was measured with differential microcalorimeter. Chemically bonded water in the hydrated cement samples was determined by thermo-gravimetry.Far less heat is liberated when cement and water come in contact for the first time, Fig. 1, than in the case for portland cement (PC. Higher water-to-cement ratio increases the heat evolved at later ages (Fig. 3 due to higher quantity of water available for hydration. A significant effect of the water-to-cement ratio on the hydration rate and hydration degree showed the importance of water as being the limiting reactant that slows down the reaction early. A simplified stoichiometric model of early age AC hydration (eq. (8 based on reaction schemes of principal minerals, nominally CA, C12A7 and C4AF (Table 1, was employed. Hydration kinetics after the induction period (ϑ < 20 °C had been successfully described (Fig. 4 and Table 2 by a proposed model (eq. (23 which simultaneously comprised three main mechanisms: nucleation and growth, interaction at phase boundary, and mass transfer. In the proposed kinetic model the nucleation and growth is proportional to the amount of reacted minerals (eq

  15. Phase transitions in biogenic amorphous calcium carbonate

    Science.gov (United States)

    Gong, Yutao

    Geological calcium carbonate exists in both crystalline phases and amorphous phases. Compared with crystalline calcium carbonate, such as calcite, aragonite and vaterite, the amorphous calcium carbonate (ACC) is unstable. Unlike geological calcium carbonate crystals, crystalline sea urchin spicules (99.9 wt % calcium carbonate and 0.1 wt % proteins) do not present facets. To explain this property, crystal formation via amorphous precursors was proposed in theory. And previous research reported experimental evidence of ACC on the surface of forming sea urchin spicules. By using X-ray absorption near-edge structure (XANES) spectroscopy and photoelectron emission microscopy (PEEM), we studied cross-sections of fresh sea urchin spicules at different stages (36h, 48h and 72h after fertilization) and observed the transition sequence of three mineral phases: hydrated ACC → dehydrated ACC → biogenic calcite. In addition, we unexpectedly found hydrated ACC nanoparticles that are surrounded by biogenic calcite. This observation indicates the dehydration from hydrated ACC to dehydrated ACC is inhibited, resulting in stabilization of hydrated ACC nanoparticles. We thought that the dehydration was inhibited by protein matrix components occluded within the biomineral, and we designed an in vitro assay to test the hypothesis. By utilizing XANES-PEEM, we found that SM50, the most abundant occluded matrix protein in sea urchin spicules, has the function to stabilize hydrated ACC in vitro.

  16. Do Calcium Supplements Predispose to Urolithiasis?

    Science.gov (United States)

    Kozyrakis, Diomidis; Paridis, Dionysios; Karatzas, Anastasios; Soukias, Georgios; Dailiana, Zoi

    2017-03-01

    The purpose of this study was to investigate the role of calcium supplements, with or without vitamin D, in urinary stone formation in healthy population and in osteoporotic patients as well. Moreover, this review aims to clarify whether or not, and above which dose, they are associated with the risk of lithiasis. A research in Medline, Embase, and Scopus databases up to September 2015 was conducted using the following keywords: calcium, supplements, vitamin D, complications, lithiasis, and urinary stone. All types of studies were taken into account (cohort studies, reviews, meta-analyses), and in case they fulfilled the inclusion criteria, they were included in our review. The analysis of the data showed that calcium supplements, probably in association with anti osteoporotic treatment, do not create a predisposition towards lithiasis formation among women suffering from osteoporosis, neither among non-osteoporotic older men. In healthy postmenopausal as well as younger women, the supplements might increase susceptibility to urinary stone formation in long-term basis. The consumption of calcium supplements with the meals could play a protective role in women and younger males. There is certain evidence that supplements containing citrate may be more beneficial over the rest of calcium supplements, particularly when consumed during the meal. Osteoporotic women and healthy men are not at risk of stone formation. On the contrary, healthy women should be aware of the potential risk of developing urinary lithiasis in long-term basis.

  17. Voltage-Gated Calcium Channels in Nociception

    Science.gov (United States)

    Yasuda, Takahiro; Adams, David J.

    Voltage-gated calcium channels (VGCCs) are a large and functionally diverse group of membrane ion channels ubiquitously expressed throughout the central and peripheral nervous systems. VGCCs contribute to various physiological processes and transduce electrical activity into other cellular functions. This chapter provides an overview of biophysical properties of VGCCs, including regulation by auxiliary subunits, and their physiological role in neuronal functions. Subsequently, then we focus on N-type calcium (Cav2.2) channels, in particular their diversity and specific antagonists. We also discuss the role of N-type calcium channels in nociception and pain transmission through primary sensory dorsal root ganglion neurons (nociceptors). It has been shown that these channels are expressed predominantly in nerve terminals of the nociceptors and that they control neurotransmitter release. To date, important roles of N-type calcium channels in pain sensation have been elucidated genetically and pharmacologically, indicating that specific N-type calcium channel antagonists or modulators are particularly useful as therapeutic drugs targeting chronic and neuropathic pain.

  18. Calcium's Role in Mechanotransduction during Muscle Development

    Directory of Open Access Journals (Sweden)

    Tatiana Benavides Damm

    2014-01-01

    Full Text Available Mechanotransduction is a process where cells sense their surroundings and convert the physical forces in their environment into an appropriate response. Calcium plays a crucial role in the translation of such forces to biochemical signals that control various biological processes fundamental in muscle development. The mechanical stimulation of muscle cells may for example result from stretch, electric and magnetic stimulation, shear stress, and altered gravity exposure. The response, mainly involving changes in intracellular calcium concentration then leads to a cascade of events by the activation of downstream signaling pathways. The key calcium-dependent pathways described here include the nuclear factor of activated T cells (NFAT and mitogen-activated protein kinase (MAPK activation. The subsequent effects in cellular homeostasis consist of cytoskeletal remodeling, cell cycle progression, growth, differentiation, and apoptosis, all necessary for healthy muscle development, repair, and regeneration. A deregulation from the normal process due to disuse, trauma, or disease can result in a clinical condition such as muscle atrophy, which entails a significant loss of muscle mass. In order to develop therapies against such diseased states, we need to better understand the relevance of calcium signaling and the downstream responses to mechanical forces in skeletal muscle. The purpose of this review is to discuss in detail how diverse mechanical stimuli cause changes in calcium homeostasis by affecting membrane channels and the intracellular stores, which in turn regulate multiple pathways that impart these effects and control the fate of muscle tissue.

  19. Effect of feeding calcium salts on performance of nursing Awassi ewes.

    Science.gov (United States)

    Obeidat, Belal S; Awawdeh, Mofleh S; Titi, Hosam H; AbuGhazaleh, Amer A; Al-Lataifeh, Fatima A; Alawneh, Ibrahim A; Abu Ishmais, Majdi A; Qudsieh, Rasha I; Subih, Hadil S

    2011-08-01

    Twenty nursing Awassi ewes (BW = 50 ± 2.35 kg, age = 4.5 ± 1.2 years) with their lambs were used to evaluate the effects of feeding calcium salts in lactation diets on performance and pre-weaning growth of their lambs. Treatments were 0% calcium salts (CON) or 5% calcium salts (FAT). At the end of the study, a digestibility experiment was performed. Milk yield was greater (P Milk composition was similar (P > 0.05) between diets. However, milk energy value (kcal/day) tended to be greater (P = 0.07) for the FAT diet than the CON diet. Concentrations of milk C18:1c9 and C20:0 were greater (P  0.05) for diets. For lambs, weaning weight was not affected by treatments. However, average daily gain and total gain were greater (P = 0.053) for the FAT diet than the CON diet. Results suggest that supplementing lactating ewes with calcium salts at the beginning of lactation phase improves daily milk yield of ewes and pre-weaning growth of their lambs with no major negative impact on feed intake and digestibility.

  20. Pulp capping with adhesive resin-based composite vs. calcium hydroxide: a review.

    Science.gov (United States)

    Schuurs, A H; Gruythuysen, R J; Wesselink, P R

    2000-12-01

    The results of some short-term experiments suggest that direct capping of a vital pulp with the modern resin-based composite systems may be as effective as capping with calcium hydroxide. Total cavity etching with 10% phosphoric acid seems to be safe for the exposed pulp, but unless annulled by calcium hydroxide 35% phosphoric acid may be disastrous. For hemostasis and cleaning of the pulp wound both sodium hypochlorite and saline seem suitable, whereas the effectiveness of a 2% chlorhexidine solution is questionable. Although hard-setting calcium hydroxide cements may induce the formation of dentin bridges, they appear not to provide an effective long-term seal against bacterial factors. Within a few years, the majority of mechanically exposed and capped pulps show infection and necrosis due to microleakage of such capping materials and tunnel defects in the dentin bridges. It is unknown whether newer types of resin containing calcium-hydroxide-products will act as a permanent barrier. The cytotoxicity of the resin-based composites and the temperature rise during polymerisation may not be of concern, but microleakage, sensitisation and allergic reactions may pose problems. Based on available data, pulp capping with resin-based composites may be said to be promising, but more and long-term research is mandatory before the method can be recommended.

  1. Calcium acetate or calcium carbonate for hyperphosphatemia of hemodialysis patients: a meta-analysis.

    Science.gov (United States)

    Wang, Yong; Xie, Guoqiang; Huang, Yuanhang; Zhang, Han; Yang, Bo; Mao, Zhiguo

    2015-01-01

    High levels of serum phosphorus both at baseline and during follow-up are associated with increased mortality in dialysis patients, and administration of phosphate binders was independently associated with improved survival among hemodialysis population. Calcium-based phosphate binders are the most commonly used phosphate binders in developing countries for their relatively low costs. To compare the efficacy and safety between calcium carbonate and calcium acetate in the treatment of hyperphosphatemia in hemodialysis patients. PubMed, EMBASE, Cochrane Library, Google scholar and Chinese databases (Wanfang, Weipu, National Knowledge Infrastructure of China) were searched for relevant studies published before March 2014. Reference lists of nephrology textbooks and review articles were checked. A meta-analysis of randomized controlled trials (RCTs) and quasi-RCTs that assessed the effects and adverse events of calcium acetate and calcium carbonate in adult patients with MHD was performed using Review Manager 5.0. A total of ten studies (625 participants) were included in this meta-analysis. There was insufficient data in all-cause mortality and cardiovascular events for meta-analysis. Compared with calcium carbonate group, the serum phosphorus was significantly lower in calcium acetate group after4 weeks' administration (MD -0.15 mmol/L, 95% CI -0.28 to -0.01) and after 8 weeks' administration (MD -0.25 mmol/L, 95% CI -0.40 to -0.11). There was no difference in serum calcium levels or the incidence of hypercalcemia between two groups at 4 weeks and 8 weeks. No statistical difference was found in parathyroid hormone (PTH) levels or serum calcium by phosphorus (Ca x P) product. There was significantly higher risk of intolerance with calcium acetate treatment (RR 3.46, 95% CI 1.48 to 8.26). For hyperphosphatemia treatment, calcium acetate showed better efficacy and with a higher incidence of intolerance compared with calcium carbonate. There are insufficient data to

  2. The effects of intracellular pH changes on resting cytosolic calcium in voltage-clamped snail neurones

    Science.gov (United States)

    Willoughby, Debbie; Thomas, Roger C; Schwiening, Christof J

    2001-01-01

    We have investigated the effects of changing intracellular pH on intracellular free calcium concentration ([Ca2+]i) in voltage-clamped neurones of the snail Helix aspersa. Intracellular pH (pHi) was measured using the fluorescent dye 8-hydroxypyrene-1,3,6-trisulphonic acid (HPTS) and changed using weak acids and weak bases. Changes in [Ca2+]i were recorded using either fura-2 or calcium-sensitive microelectrodes. Acidification of the neurones with 5 mM or 20 mM propionate (∼0.2 or 0.3 pH units acidification, respectively) caused a small reduction in resting [Ca2+]i of 5 ± 2 nM (n = 4) and 7 ± 16 nM (n = 4), respectively. The removal of the 20 mM propionate after ∼40 min superfusion resulted in an alkalinization of ∼0.35 pH units and an accompanying rise in resting [Ca2+]i of 31 ± 9 nM (n = 4, P Helix neurones induced by superfusion with 3 mM concentrations of the weak bases trimethylamine (TMA), ammonium chloride (NH4Cl) and procaine were accompanied by significant (P < 0.05) increases in resting [Ca2+]i of 42 ± 4 nM (n = 26), 30 ± 7 nM (n = 5) and 36 ± 4 nM (n = 3), respectively. The effect of TMA (0.5-6 mM) on [Ca2+]i was dose dependent with an increase in [Ca2+]i during pHi increases of less than 0.1 pH units (0.5 mM TMA). Superfusion of neurones with zero calcium (1 mM EGTA) Ringer solution inhibited depolarization-induced calcium increases but not the calcium increase produced by the first exposure to TMA (3 mM). In the prolonged absence of extracellular calcium (∼50 min) TMA-induced calcium rises were decreased by 64 ± 10% compared to those seen in the presence of external calcium (P < 0.05). The calcium rise induced by TMA (3 mM) was reduced by 60 ± 5% following a 10 min period of superfusion with caffeine (10 mM) to deplete the endoplasmic reticulum (ER) stores of calcium (P < 0.05). Cyclopiazonic acid (10-30 μM CPA), an inhibitor of the ER calcium pump, inhibited the calcium rise produced by TMA (3 mM) and NH4Cl (3 mM) by 61 ± 4% compared

  3. Toxicity of calcium salts to aqueous microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Lakhina, K.G.; Dolganova, A.V.; Yakobi, L.K.

    1983-03-01

    This article investigates the toxicity of calcium to aqueous microogranisms by means of a procedure developed by VNII VODGEO (All-Union Scientific-Research Institute of Water Supply, Sewer Systems, Hydrotechnical Facilities, and Engineering Hydrogeology), with certain changes in the preparation of the culture water. Proposes that with this method, calcium toxicity can be determined for groups of microorganisms that are among the most important in biochemical wastewater treatment and self-purification of water bodies (saprophytes, phase I and II nitrifiers). Finds that calcium in the form of the hydroxide and chloride is nontoxic under the following conditions: for protozoa in concentrations up to 2 g/liter, for saprophytic bacteria up to 3 g/liter, for phase I nitrifiers up to 1 g/liter, and for phase II nitrifiers up to 0.1 g/liter.

  4. Magnesium and Calcium in Isolated Cell Nuclei

    Science.gov (United States)

    Naora, H.; Naora, H.; Mirsky, A. E.; Allfrey, V. G.

    1961-01-01

    The calcium and magnesium contents of thymus nuclei have been determined and the nuclear sites of attachment of these two elements have been studied. The nuclei used for these purposes were isolated in non-aqueous media and in sucrose solutions. Non-aqueous nuclei contain 0.024 per cent calcium and 0.115 per cent magnesium. Calcium and magnesium are held at different sites. The greater part of the magnesium is bound to DNA, probably to its phosphate groups. Evidence is presented that the magnesium atoms combined with the phosphate groups of DNA are also attached to mononucleotides. There is reason to believe that those DNA-phosphate groups to which magnesium is bound, less than 1/10th of the total, are metabolically active, while those to which histones are attached seem to be inactive. PMID:13727745

  5. OSTEOPOROSIS IN CALCIUM PYROPHOSPHATE CRYSTAL DEPOSITION DISEASE

    Directory of Open Access Journals (Sweden)

    S A Vladimirov

    2013-01-01

    Full Text Available Objective: to study the incidence of osteoporosis (OP in patients with calcium pyrophosphate crystal deposition disease (CPCDD. Subjects and methods. Eighty patients with CPCDD were examined. Bone mineral density (BMD of the forearm, lumbar spine, and femoral neck was determined by dual-energy X-ray absorptiometry. Laboratory diagnosis involved determination of the blood levels of C-reactive protein, parathyroid hormone, calcium, magnesium, and phosphorus and the daily urinary excretion of calcium and phosphates. Results. The patients with OP were significantly older than those with normal BMD and osteopenia. Forearm bones were the most common isolated location of OP and osteopenia. Injuries in the history, traumatic fractures, and the intake of diuretics were somewhat more common in the patients diagnosed with OP. The incidence of hyperparathyroidism did not differ significantly in the groups.

  6. In situ preparation of Calcium hydroxide films

    Energy Technology Data Exchange (ETDEWEB)

    Dahle, S.; Voigts, F. [Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); Maus-Friedrichs, W., E-mail: w.maus-friedrichs@pe.tu-clausthal.de [Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); Clausthaler Zentrum fuer Materialtechnik, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany)

    2011-10-31

    The in situ preparation of Calcium hydroxide films in an ultra high vacuum (UHV) is constrained by the decomposition of species at the surface and the absence of OH bulk diffusion. Therefore, it is not possible to prepare such films simply by water exposure to a Calcium layer. We present four different approaches for the preparation of Ca(OH){sub 2} films in an UHV. Two of these methods are found to be ineffective for the preparation, the other two are shown to produce Calcium hydroxide films. Both of the two effective procedures make use of H{sub 2} gas exposure. Metastable Induced Electron Spectroscopy, Ultraviolet Photoelectron Spectroscopy, and X-ray Photoelectron Spectroscopy are employed to verify quality and purity of the films.

  7. In situ preparation of calcium carbonate films

    Energy Technology Data Exchange (ETDEWEB)

    Dahle, S. [Clausthaler Zentrum fuer Materialtechnik, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); Voigts, F. [Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); Maus-Friedrichs, W., E-mail: w.maus-friedrichs@pe.tu-clausthal.de [Clausthaler Zentrum fuer Materialtechnik, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany)

    2012-01-01

    The in situ preparation of calcium carbonate films in an ultra high vacuum (UHV) is inhibited by the decomposition of CO{sub 2} molecules at the surface and the absence of CO{sub 2} bulk diffusion. Therefore, it is not possible to prepare such films simply by CO{sub 2} exposure to a calcium layer. We investigated different approaches for the preparation of CaCO{sub 3} films in an UHV. Among these, only the simultaneous evaporation of Ca atoms in a mixed O{sub 2} and CO{sub 2} atmosphere is able to produce well defined stoichiometric calcium carbonate films. Metastable Induced Electron Spectroscopy, Ultraviolet Photoelectron Spectroscopy and X-ray Photoelectron Spectroscopy are employed to verify quality and purity of the films.

  8. Calcination of calcium carbonate and blend therefor

    Science.gov (United States)

    Mallow, William A.; Dziuk, Jr., Jerome J.

    1989-01-01

    A method for calcination of a calcium carbonate material comprising heating the calcium carbonate material to a temperature and for a time sufficient to calcine the material to the degree desired while in the presence of a catalyst; said catalyst comprising at least one fused salt having the formula MCO.sub.3.CaCO.sub.3.CaO.H.sub.2 O.sub.x, wherein M is an alkali metal and x is 0 to 1 and formed by fusing MCO.sub.3 and CaCO.sub.3 in a molar ratio of about 1:2 to 2:1, and a blend adapted to be heated to CaO comprising a calcium carbonate material and at least one such fused salt.

  9. Synthesis of Portland cement and calcium sulfoaluminate-belite cement for sustainable development and performance

    Science.gov (United States)

    Chen, Irvin Allen

    Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive, accounting for 2% of primary energy consumption and 5% of industrial energy consumption globally. Moreover, portland cement manufacturing contributes significantly to greenhouse gases and accounts for 5% of the global CO2 emissions resulting from human activity. The primary objective of this research was to explore methods of reducing the environmental impact of cement production while maintaining or improving current performance standards. Two approaches were taken, (1) incorporation of waste materials in portland cement synthesis, and (2) optimization of an alternative environmental friendly binder, calcium sulfoaluminate-belite cement. These approaches can lead to less energy consumption, less emission of CO2, and more reuse of industrial waste materials for cement manufacturing. In the portland cement part of the research, portland cement clinkers conforming to the compositional specifications in ASTM C 150 for Type I cement were successfully synthesized from reagent-grade chemicals with 0% to 40% fly ash and 0% to 60% slag incorporation (with 10% intervals), 72.5% limestone with 27.5% fly ash, and 65% limestone with 35% slag. The synthesized portland cements had similar early-age hydration behavior to commercial portland cement. However, waste materials significantly affected cement phase formation. The C3S--C2S ratio decreased with increasing amounts of waste materials incorporated. These differences could have implications on proportioning of raw materials for cement production when using waste materials. In the calcium sulfoaluminate-belite cement part of the research, three calcium sulfoaluminate-belite cement clinkers with a range of phase compositions were successfully synthesized from reagent-grade chemicals. The synthesized calcium sulfoaluminate

  10. Calcium pathway machinery at fertilization in echinoderms.

    Science.gov (United States)

    Ramos, Isabela; Wessel, Gary M

    2013-01-01

    Calcium signaling in cells directs diverse physiological processes. The calcium waves triggered by fertilization is a highly conserved calcium signaling event essential for egg activation, and has been documented in every egg tested. This activity is one of the few highly conserved events of egg activation through the course of evolution. Echinoderm eggs, as well as many other cell types, have three main intracellular Ca(2+) mobilizing messengers - IP3, cADPR and NAADP. Both cADPR and NAADP were identified as Ca(2+) mobilizing messengers using the sea urchin egg homogenate, and this experimental system, along with the intact urchin and starfish oocyte/egg, continues to be a vital tool for investigating the mechanism of action of calcium signals. While many of the major regulatory steps of the IP3 pathway are well resolved, both cADPR and NAADP remain understudied in terms of our understanding of the fundamental process of egg activation at fertilization. Recently, NAADP has been shown to trigger Ca(2+) release from acidic vesicles, separately from the ER, and a new class of calcium channels, the two-pore channels (TPCs), was identified as the likely targets for this messenger. Moreover, it was found that both cADPR and NAADP can be synthesized by the same family of enzymes, the ADP-rybosyl cyclases (ARCs). In this context of increasing amount of information, the potential coupling and functional roles of different messengers, intracellular stores and channels in the formation of the fertilization calcium wave in echinoderms will be critically evaluated. Copyright © 2012. Published by Elsevier India Pvt Ltd.

  11. Characterization of Calcium Compounds in Opuntia ficus indica as a Source of Calcium for Human Diet

    Directory of Open Access Journals (Sweden)

    Isela Rojas-Molina

    2015-01-01

    Full Text Available Analyses of calcium compounds in cladodes, soluble dietary fiber (SDF, and insoluble dietary fiber (IDF of Opuntia ficus indica are reported. The characterization of calcium compounds was performed by using Scanning Electron Microscopy, Energy Dispersive Spectrometry, X-ray diffraction, and infrared spectroscopy. Atomic Absorption Spectroscopy and titrimetric methods were used for quantification of total calcium and calcium compounds. Whewellite (CaC2O4·H2O, weddellite (CaC2O4·(H2O2.375, and calcite (CaCO3 were identified in all samples. Significant differences (P≤0.05 in the total calcium contents were detected between samples. CaC2O4·H2O content in cladodes and IDF was significantly higher (P≤0.05 in comparison to that observed in SDF, whereas minimum concentration of CaCO3 was detected in IDF with regard to CaCO3 contents observed in cladodes and SDF. Additionally, molar ratio oxalate : Ca2+ in all samples changed in a range from 0.03 to 0.23. These results support that calcium bioavailability in O. ficus indica modifies according to calcium compounds distribution.

  12. Calcium carbonate phase transformations during the carbonation reaction of calcium heavy alkylbenzene sulfonate overbased nanodetergents preparation.

    Science.gov (United States)

    Chen, Zhaocong; Xiao, Shan; Chen, Feng; Chen, Dongzhong; Fang, Jianglin; Zhao, Min

    2011-07-01

    The preparation and application of overbased nanodetergents with excess alkaline calcium carbonate is a good example of nanotechnology in practice. The phase transformation of calcium carbonate is of extensive concern since CaCO(3) serves both as an important industrial filling material and as the most abundant biomineral in nature. Industrially valuable overbased nanodetergents have been prepared based on calcium salts of heavy alkylbenzene sulfonate by a one-step process under ambient pressure, the carbonation reaction has been monitored by the instantaneous temperature changes and total base number (TBN). A number of analytical techniques such as TGA, DLS, SLS, TEM, FTIR, and XRD have been utilized to explore the carbonation reaction process and phase transformation mechanism of calcium carbonate. An enhanced understanding on the phase transformation of calcium carbonate involved in calcium sulfonate nanodetergents has been achieved and it has been unambiguously demonstrated that amorphous calcium carbonate (ACC) transforms into the vaterite polymorph rather than calcite, which would be of crucial importance for the preparation and quality control of lubricant additives and greases. Our results also show that a certain amount of residual Ca(OH)(2) prevents the phase transformation from ACC to crystalline polymorphs. Moreover, a vaterite nanodetergent has been prepared for the first time with low viscosity, high base number, and uniform particle size, nevertheless a notable improvement on its thermal stability is required for potential applications. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Comparison of Ferrous Calcium Silicate Slag and Calcium Ferrite Slag Interactions with Magnesia-Chrome Refractories

    Science.gov (United States)

    Kaur, R. R.; Swinbourne, D. R.; Wadsley, M. W.; Nexhip, C.

    2011-06-01

    The cost of maintaining and eventually replacing refractories as a result of slag attack is a significant cost component in the copper industry. Converting matte to blister copper takes place in reactors lined with direct-bonded magnesia-chrome refractories, and several continuous converting operations use calcium ferrite slag. Unfortunately, the low viscosity of calcium ferrite slag makes it aggressive toward the refractories. Ferrous calcium silicate (FCS) slag has been proposed as a replacement; however, the effect of this slag on magnesia-chrome refractories has not been studied. In this work, the interactions between FCS slag and magnesia-chrome refractory at 1573 K (1300 °C) with an oxygen partial pressure of 10-6 atm were studied and compared with that experienced with calcium ferrite slag under the same conditions. Both slags penetrated the pores in the refractory and caused compositional change in the chromite spinel intergranular bonding phase through cation interdiffusion, which resulted in cracking and debonding of periclase grains. It was observed that the refractory was penetrated much more deeply by calcium ferrite slag than FCS slag because of the higher surface tension and lower viscosity of calcium ferrite slag. As a result, the refractory was attacked less by FCS slag than it was by calcium ferrite slag. It is concluded that the use of FCS slag in continuous copper converting is likely to extend refractory life.

  14. 46 CFR 35.35-60 - Transportation of other cargo or stores on tank barges-B/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Transportation of other cargo or stores on tank barges-B/ALL. 35.35-60 Section 35.35-60 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Cargo Handling § 35.35-60 Transportation of other cargo or stores on tank barges—B/ALL. (a) Tank...

  15. Calcium Oxalate: A Surface Treatment for Limestone

    Directory of Open Access Journals (Sweden)

    Tody M. Cezar

    1998-05-01

    Full Text Available This paper looks at the artificially induced surface conversion of calcium carbonate to the more durable calcium oxalate. Extensive research is being carried out on wall paintings and marble sculpture at the Opicificio delle Pietre Dure e Laboratori di Restauro in Florence, Encouraged by their work, I have researched the effectiveness of the conversion on English limestones. The treated samples have been compared to untreated samples for appearance, hardness, resistance to acid and alkali, porosity, and durability. The results have been assessed considering ease of use, effectiveness, and the appropriateness of the treatment.

  16. Evolutionary Diversity of the Mitochondrial Calcium Uniporter

    Science.gov (United States)

    Bick, Alexander G.; Calvo, Sarah E.; Mootha, Vamsi K.

    2012-01-01

    Calcium uptake into mitochondria occurs via a recently identified ion channel called the uniporter. Here, we characterize the phylogenomic distribution of the uniporter’s membrane-spanning pore subunit (MCU) and regulatory partner (MICU1). Homologs of both components tend to co-occur in all major branches of eukaryotic life, but both have been lost along certain protozoan and fungal lineages. Several bacterial genomes also contain putative MCU homologs that may represent prokaryotic calcium channels. The analyses indicate that the uniporter may have been an early feature of mitochondria. PMID:22605770

  17. Biotic Nitrogen Enrichment Regulates Calcium Sources to Forests

    Science.gov (United States)

    Pett-Ridge, J. C.; Perakis, S. S.; Hynicka, J. D.

    2015-12-01

    Calcium is an essential nutrient in forest ecosystems that is susceptible to leaching loss and depletion. Calcium depletion can affect plant and animal productivity, soil acid buffering capacity, and fluxes of carbon and water. Excess nitrogen supply and associated soil acidification are often implicated in short-term calcium loss from soils, but the long-term role of nitrogen enrichment on calcium sources and resupply is unknown. Here we use strontium isotopes (87Sr/86Sr) as a proxy for calcium to investigate how soil nitrogen enrichment from biological nitrogen fixation interacts with bedrock calcium to regulate both short-term available supplies and the long-term sources of calcium in montane conifer forests. Our study examines 22 sites in western Oregon, spanning a 20-fold range of bedrock calcium on sedimentary and basaltic lithologies. In contrast to previous studies emphasizing abiotic control of weathering as a determinant of long-term ecosystem calcium dynamics and sources (via bedrock fertility, climate, or topographic/tectonic controls) we find instead that that biotic nitrogen enrichment of soil can strongly regulate calcium sources and supplies in forest ecosystems. For forests on calcium-rich basaltic bedrock, increasing nitrogen enrichment causes calcium sources to shift from rock-weathering to atmospheric dominance, with minimal influence from other major soil forming factors, despite regionally high rates of tectonic uplift and erosion that can rejuvenate weathering supply of soil minerals. For forests on calcium-poor sedimentary bedrock, we find that atmospheric inputs dominate regardless of degree of nitrogen enrichment. Short-term measures of soil and ecosystem calcium fertility are decoupled from calcium source sustainability, with fundamental implications for understanding nitrogen impacts, both in natural ecosystems and in the context of global change. Our finding that long-term nitrogen enrichment increases forest reliance on atmospheric

  18. Voltage-gated calcium flux mediatesEscherichia colimechanosensation.

    Science.gov (United States)

    Bruni, Giancarlo N; Weekley, R Andrew; Dodd, Benjamin J T; Kralj, Joel M

    2017-08-29

    Electrically excitable cells harness voltage-coupled calcium influx to transmit intracellular signals, typically studied in neurons and cardiomyocytes. Despite intense study in higher organisms, investigations of voltage and calcium signaling in bacteria have lagged due to their small size and a lack of sensitive tools. Only recently were bacteria shown to modulate their membrane potential on the timescale of seconds, and little is known about the downstream effects from this modulation. In this paper, we report on the effects of electrophysiology in individual bacteria. A genetically encoded calcium sensor expressed in Escherichia coli revealed calcium transients in single cells. A fusion sensor that simultaneously reports voltage and calcium indicated that calcium influx is induced by voltage depolarizations, similar to metazoan action potentials. Cytoplasmic calcium levels and transients increased upon mechanical stimulation with a hydrogel, and single cells altered protein concentrations dependent on the mechanical environment. Blocking voltage and calcium flux altered mechanically induced changes in protein concentration, while inducing calcium flux reproduced these changes. Thus, voltage and calcium relay a bacterial sense of touch and alter cellular lifestyle. Although the calcium effectors remain unknown, these data open a host of new questions about E. coli , including the identity of the underlying molecular players, as well as other signals conveyed by voltage and calcium. These data also provide evidence that dynamic voltage and calcium exists as a signaling modality in the oldest domain of life, and therefore studying electrophysiology beyond canonical electrically excitable cells could yield exciting new findings.

  19. Calcium intake, polymorphisms of the calcium-sensing receptor, and recurrent/aggressive prostate cancer.

    Science.gov (United States)

    Binder, Moritz; Shui, Irene M; Wilson, Kathryn M; Penney, Kathryn L; Mucci, Lorelei A; Kibel, Adam S

    2015-12-01

    To assess whether calcium intake and common genetic variants of the calcium-sensing receptor (CASR) are associated with either aggressive prostate cancer (PCa) or disease recurrence after prostatectomy. Calcium intake at diagnosis was assessed, and 65 common single-nucleotide polymorphisms (SNPs) in CASR were genotyped in 886 prostatectomy patients. We investigated the association between calcium intake and CASR variants with both PCa recurrence and aggressiveness (defined as Gleason score ≥4 + 3, stage ≥pT3, or nodal-positive disease). A total of 285 men had aggressive disease and 91 experienced recurrence. A U-shaped relationship between calcium intake and both disease recurrence and aggressiveness was observed. Compared to the middle quintile, the HR for disease recurrence was 3.07 (95% CI 1.41-6.69) for the lowest quintile and 3.21 (95% CI 1.47-7.00) and 2.97 (95% CI 1.37-6.45) for the two upper quintiles, respectively. Compared to the middle quintile, the OR for aggressive disease was 1.80 (95% CI 1.11-2.91) for the lowest quintile and 1.75 (95% CI 1.08-2.85) for the highest quintile of calcium intake. The main effects of CASR variants were not associated with PCa recurrence or aggressiveness. In the subgroup of patients with moderate calcium intake, 31 SNPs in four distinct blocks of high linkage disequilibrium were associated with PCa recurrence. We observed a protective effect of moderate calcium intake for PCa aggressiveness and recurrence. While CASR variants were not associated with these outcomes in the entire cohort, they may be associated with disease recurrence in men with moderate calcium intakes.

  20. Do calcium buffers always slow down the propagation of calcium waves?

    Science.gov (United States)

    Tsai, Je-Chiang

    2013-12-01

    Calcium buffers are large proteins that act as binding sites for free cytosolic calcium. Since a large fraction of cytosolic calcium is bound to calcium buffers, calcium waves are widely observed under the condition that free cytosolic calcium is heavily buffered. In addition, all physiological buffered excitable systems contain multiple buffers with different affinities. It is thus important to understand the properties of waves in excitable systems with the inclusion of buffers. There is an ongoing controversy about whether or not the addition of calcium buffers into the system always slows down the propagation of calcium waves. To solve this controversy, we incorporate the buffering effect into the generic excitable system, the FitzHugh-Nagumo model, to get the buffered FitzHugh-Nagumo model, and then to study the effect of the added buffer with large diffusivity on traveling waves of such a model in one spatial dimension. We can find a critical dissociation constant (K = K(a)) characterized by system excitability parameter a such that calcium buffers can be classified into two types: weak buffers (K ∈ (K(a), ∞)) and strong buffers (K ∈ (0, K(a))). We analytically show that the addition of weak buffers or strong buffers but with its total concentration b(0)(1) below some critical total concentration b(0,c)(1) into the system can generate a traveling wave of the resulting system which propagates faster than that of the origin system, provided that the diffusivity D1 of the added buffers is sufficiently large. Further, the magnitude of the wave speed of traveling waves of the resulting system is proportional to √D1 as D1 --> ∞. In contrast, the addition of strong buffers with the total concentration b(0)(1) > b(0,c)(1) into the system may not be able to support the formation of a biologically acceptable wave provided that the diffusivity D1 of the added buffers is sufficiently large.

  1. 40 CFR 35.9030 - Work program.

    Science.gov (United States)

    2010-07-01

    ... ASSISTANCE Financial Assistance for the National Estuary Program § 35.9030 Work program. The work program is part of the application for financial assistance and becomes part of the award document. It is part of the basis for an award decision and the basis for management and evaluation of performance under an...

  2. 10 CFR 35.13 - License amendments.

    Science.gov (United States)

    2010-01-01

    ... where PET radionuclides are produced or a PET radioactive drug delivery line from the PET radionuclide/PET radioactive drug production area. Other areas of use where byproduct material is used only in... REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Information § 35.13 License amendments. A...

  3. 10 CFR 35.14 - Notifications.

    Science.gov (United States)

    2010-01-01

    ... produced or a PET radioactive drug delivery line from the PET radionuclide/PET radioactive drug production... REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL General Information § 35.14 Notifications. (a) A... master material licensee, the permit issued by a Commission or Agreement State licensee of broad scope...

  4. Geometry task sheets : grades 3-5

    CERN Document Server

    Rosenberg, Mary

    2009-01-01

    For grades 3-5, our Common Core State Standards-based resource meets the geometry concepts addressed by the NCTM standards and encourages the students to learn and review the concepts in unique ways. Each task sheet is organized around a central problem taken from real-life experiences of the students.

  5. 17 CFR 35.1 - Definitions.

    Science.gov (United States)

    2010-04-01

    ... collar agreement, currency swap agreement, cross-currency rate swap agreement, currency option, any other... Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION EXEMPTION OF SWAP AGREEMENTS § 35.1 Definitions. (a) Scope. The provisions of this part shall apply to any swap agreement which may be subject to...

  6. 46 CFR 58.16-35 - Markings.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-35 Markings. (a) The outside of the cylinder enclosure housing liquefied petroleum gas cylinders, valves and regulators shall be marked as...

  7. 24 CFR 58.35 - Categorical exclusions.

    Science.gov (United States)

    2010-04-01

    ...) Tenant-based rental assistance; (2) Supportive services including, but not limited to, health care, housing services, permanent housing placement, day care, nutritional services, short-term payments for... Environmental Review Process: Documentation, Range of Activities, Project Aggregation and Classification § 58.35...

  8. 49 CFR 230.35 - Pressure testing.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Pressure Testing of Boilers § 230.35 Pressure testing. The temperature of the steam locomotive boiler shall be raised to at least 70 deg. F any time hydrostatic pressure is applied to the boiler. ...

  9. 46 CFR 194.10-35 - Labeling.

    Science.gov (United States)

    2010-10-01

    ... CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Magazines § 194.10-35 Labeling. (a) Labeling shall be... door to magazines and magazine vans shall bear the inscription: MAGAZINE KEEP OPEN LIGHTS AND FIRE AWAY... conspicuous location, preferably the top, with the inscription: MAGAZINE CHEST KEEP OPEN LIGHTS AND FIRE AWAY...

  10. 40 CFR 35.2030 - Facilities planning.

    Science.gov (United States)

    2010-07-01

    ... description of the Best Practicable Wastewater Treatment Technology. (See § 35.2005(b)(7).) (3) A cost..., processes and techniques capable of meeting the applicable effluent, water quality and public health... wastewater and sludge material resulting from the treatment process; (v) A consideration of systems with...

  11. 40 CFR 86.098-35 - Labeling.

    Science.gov (United States)

    2010-07-01

    ...) introductory text through (a)(1)(iii)(B) . For guidance see § 86.095-35. (a)(1)(iii)(C) Engine displacement (in... EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks and Heavy-Duty Engines, and for...

  12. 40 CFR 86.007-35 - Labeling.

    Science.gov (United States)

    2010-07-01

    ...) heading through (b) . For guidance see § 86.095-35. (c) Vehicles powered by model year 2007 and later... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for...

  13. Unique biosynthesis of sesquarterpenes (C35 terpenes).

    Science.gov (United States)

    Sato, Tsutomu

    2013-01-01

    To the best of my knowledge, only 19 cyclic and 8 linear C35 terpenes have been identified to date, and no family name was assigned to this terpene class until recently. In 2011, it was proposed that these C35 terpenes should be called sesquarterpenes. This review highlights the biosynthesis of two kinds of sesquarterpenes (C35 terpenes) that are produced via cyclization of a linear C35 isoprenoid in Bacillus and Mycobacterium species. In Bacillus species, a new type of terpene cyclase that has no sequence homology with any known terpene synthases, as well as a bifunctional terpene cyclase that biosynthesizes two classes of cyclic terpenes with different numbers of carbons as natural products, have been identified. On the other hand, in Mycobacterium species, the first bifunctional Z-prenyltransferase has been found, but a novel terpene cyclase and a unique polyprenyl reductase remain unidentified. The identification of novel enzyme types should lead to the discovery of many homologous enzymes and their products including novel natural compounds. On the other hand, many enzymes responsible for the biosynthesis of natural products have low substrate specificities in vitro. Therefore, to find novel natural products present in organisms, the multifunctionality of enzymes in the biosynthetic pathway of natural products should be analyzed.

  14. Africa Insight - Vol 35, No 1 (2005)

    African Journals Online (AJOL)

    The New Partnership for Africa\\'s Development: Promoting Foreign Direct Investment Through Moral Political Leadership · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Zein Kebonang, 3-13. http://dx.doi.org/10.4314/ai.v35i1.22419 ...

  15. Water SA - Vol 35, No 2 (2009)

    African Journals Online (AJOL)

    Characterisation of natural organic matter (NOM) and its removal using cyclodextrin polyurethanes · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. TI Nkambule, RWM Krause, BB Mamba, J Haarhoff. http://dx.doi.org/10.4314/wsa.v35i2.76755 ...

  16. 40 CFR 35.6595 - Contract provisions.

    Science.gov (United States)

    2010-07-01

    ... must comply with 40 CFR 31.36(i)(3) through (6). (4) Conflict of interest. The recipient must include provisions pertaining to conflict of interest as described in § 35.6550(b)(2)(ii). ... regulations pertaining to reporting and patent rights under any contract involving research, developmental...

  17. Water SA - Vol 35, No 3 (2009)

    African Journals Online (AJOL)

    Performance of tubular reverse osmosis for the desalination/concentration of a municipal solid waste leachate · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. JJ Schoeman, LJ Strachan. http://dx.doi.org/10.4314/wsa.v35i3.76776 ...

  18. Water SA - Vol 35, No 1 (2009)

    African Journals Online (AJOL)

    Environmental life cycle assessments for water treatment processes – A South African case study of an urban water cycle · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. E Friedrich, S Pillay, CA Buckley. http://dx.doi.org/10.4314/wsa.v35i1.76710 ...

  19. Africa Insight - Vol 35, No 2 (2005)

    African Journals Online (AJOL)

    Editorial East African popular culture and literature · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. James Ogude, Joyce Nyairo, 2-3. http://dx.doi.org/10.4314/ai.v35i2.22428 ...

  20. 20 CFR 655.35 - Required departure.

    Science.gov (United States)

    2010-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TEMPORARY EMPLOYMENT OF... Temporary Employment in Occupations Other Than Agriculture or Registered Nursing in the United States (H-2B Workers) § 655.35 Required departure. (a) Limit to worker's stay. As defined further in DHS regulations, a...

  1. Africa Insight - Vol 35, No 4 (2005)

    African Journals Online (AJOL)

    Planning or doing local economic development? Problems with the orthodox approach to LED · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Shawn Cunningham, Jörg Meyer-Stamer, 4-14. http://dx.doi.org/10.4314/ai.v35i4.22449 ...

  2. Vitamin d deficiency is associated with insulin resistance independent of intracellular calcium, dietary calcium and serum levels of parathormone, calcitriol and calcium in premenopausal women.

    Science.gov (United States)

    Ferreira, Thaís da Silva; Rocha, Tatiana Martins; Klein, Márcia Regina Simas Torres; Sanjuliani, Antonio Felipe

    2015-04-01

    There is evidence that vitamin D deficiency is associated with increased risk of cardiovascular disease. However, it is not known if this association is independent of dietary calcium, intracellular calcium and serum levels of parathormone, calcitriol and calcium. To investigate the independent relationship of vitamin D deficiency with insulin resistance, lipid profile, inflammatory status, blood pressure and endothelial function. Cross-sectional study conducted with 73 healthy Brazilian premenopausal women aged 18 - 50 years. All participants were evaluated for: 25 hydroxyvitamin D serum levels, anthropometric parameters, body composition, calcium metabolism, insulin resistance, lipoprotein profile, inflammatory status, blood pressure and endothelial function. Endothelial function was assessed by reactive hyperemia index using Endo-PAT 2000®. Women were stratified in two groups: with vitamin D deficiency (25 hydroxyvitamin D independent of dietary calcium, intracellular calcium and serum levels of parathormone, calcitriol and calcium in healthy premenopausal women. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  3. Calcium pyrophosphate dihydrate deposition disease (CPPD/Pseudogout of the temporomandibular joint – FNA findings and microanalysis

    Directory of Open Access Journals (Sweden)

    Naqvi Asghar H

    2008-04-01

    Full Text Available Abstract We report a case of a Calcium pyrophosphate dihydrate deposition disease (CPPD presenting as a mass in the parotid and temporomandibular joint (TMJ that simulated a parotid tumor. A 35 year-old man presented with pain in the left ear area. A CT Scan of the area showed a large, calcified mass surrounding the left condylar head, and extending into the infratemporal fossa. FNA of the mass showed birefringent crystals, most of which were rhomboid with occasional ones being needle shaped, embedded in an amorphous pink substance. Scanning electron microscopy (SEM with energy dispersive x-ray spectroscopy (EDS of these crystals showed peaks corresponding to calcium and phosphorus. SEM/EDS is a rapid method of diagnosing calcium pyrophosphate dihydrate deposition disease (CPPD and an alternative to more commonly used method of special staining of cell block sections coupled with polarizing microscopy.

  4. Successful pregnancy and childbirth after intracytoplasmic sperm injection with calcium ionophore oocyte activation in a globozoospermic patient.

    Science.gov (United States)

    Tejera, Alberto; Mollá, Marta; Muriel, Lourdes; Remohí, Jose; Pellicer, Antonio; De Pablo, Jose Luis

    2008-10-01

    To check the effectiveness of intracytoplasmic sperm injection (ICSI) combined with assisted oocyte activation (AOA) in a globozoospermic patient. Case report. Instituto Valenciano de Infertilidad, Valencia, Spain. A patient with globozoospermia. ICSI was administered in 14 oocytes. ICSI combined with AOA, in which a small amount of calcium was injected followed by calcium ionophore exposure, was done in 9 oocytes. Fertilization rate and embryo quality was assessed in both groups. Chemical activation increased fertilization rate (55.6% vs. 35.7%) and the number of embryos with less multinucleation on day 2 (0 vs. 60%). Two embryos generated from AOA were transferred into the uterus (on day 3), resulting in a pregnancy and a healthy newborn. The AOA with calcium ionophore treatment improved fertilization rate and quality of the embryos, and was found to be an effective method for AOA in this patient with a low fertilization rate after previous ICSI treatment.

  5. Avian eggshell formation in calcium-rich and calcium-poor habitats: Importance of snail shells and anthropogenic calcium sources

    NARCIS (Netherlands)

    Graveland, J.

    1996-01-01

    Most passerines depend on the intake of calcium-rich material in addition to their normal food for proper eggshell formation and skeletal growth. A large proportion of Great Tits (Pants major) in forests on nutrient-poor soils in the Netherlands produce eggs with defective shells as a result of

  6. Localization of calcium signals by a mobile calcium buffer in frog saccular hair cells.

    Science.gov (United States)

    Roberts, W M

    1994-05-01

    A recent study (Roberts, 1993) of saccular hair cells from grass frogs (Rana pipiens) has suggested a mechanism by which the unusually high concentrations of calcium-binding proteins found in certain sensory receptors and neurons, particularly in the auditory system, can influence short-range intracellular calcium signaling. In frog saccular hair cells, the mechanism operates within arrays of calcium channels and calcium-activated potassium channels that are involved in the cells' electrical resonance and synaptic transmission. The present study tests the hypothesis that calbindin-D28k, one of the most abundant proteins in these cells, can serve as a mobile calcium buffer that reduces and localizes changes in the intracellular free-calcium concentration ([Ca2+]i) by shuttling calcium away from the channel arrays. Based upon theoretical analysis and computer modeling, it is shown that [Ca2+]i near one or more open channels quickly reaches a steady-state level determined primarily by two properties of the buffer, the mean time (tau c) before it captures a free-calcium ion and a replenishment factor (R), which are related to the buffer's diffusional mobility (DBu), association rate constant (kon), and concentration (Bo) by tau c = (konB0)-1 and R = B0DBu. Simulation of calcium entry through a channel array showed that approximately 1.5 mM of a molecule with the diffusional and binding properties expected for calbindin-D28k (Bo approximately 8 mM calcium-binding sites) is needed to reproduce the previous experimental results. A lower concentration (B0 = 2 mM) was almost completely depleted within the channel array by a modest calcium current (8 pA = 12% of calcium channels open), but still had two important effects: it caused [Ca2+]i to fall steeply with distance outside the array (space constant < 50 nm), and returned [Ca2+]i quickly to the resting level after the channels closed. A high concentration of calbindin-D28k can thus influence the cell's electrical

  7. Effects of extracellular calcium on calcium transport during hyperthermia of tumor cells.

    Science.gov (United States)

    Anghileri, L J; Marcha, C; Crone-Escanyé, M C; Robert, J

    1985-08-01

    The effects of different concentrations of extracellular ion calcium on the transport of calcium by tumor cells have been studied by means of the uptake of radiocalcium. Tumor cells incubated at 45 degrees C take up 4-10 times the amount of radioactivity incorporated by cells incubated at 37 degrees C. The difference is still greater (up to 100 times) for the intracellular incorporation as assessed by elimination of the membrane-bound calcium by EGTA treatment. The possible mechanisms involved in this differential behavior are discussed.

  8. Tribological and Antioxidation Synergistic Effect Study of Sulfonate-Modified Nano Calcium Carbonate

    Science.gov (United States)

    Zhongyi, He; Liping, Xiong; Sheng, Han; Aixi, Chen; Jianwei, Qiu; Xisheng, Fu

    2013-01-01

    A middle base number sulphonate-modified nano calcium carbonate (SMC) with an average size of 35 nm was synthesized, and its tribological and antioxidation synergistic behaviors with ashless antioxidant N-phenyl-α-naphthylamine (T531) in hydrogenated oil (5Cst) were evaluated. The results demonstrate that adding this synethesized additive even at a low amount (chemical composition of the rubbing surface which formed on the boundary film was analyzed by using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicating that the excellent antiwear and load-carrying performance could be attributed to the forming of boundary lubrication film which composed of calcium carbonate, oxides, ferrites, sulphide and FeSO4, and so on. Its ability to increase oxidation free energy of base oil is the main reason for increasing its antioxidant collaboration property with ashless antioxidant T531. PMID:23658705

  9. Calcium pyrophosphate dihydrate deposition in the trochanteric hip bursa presenting as acute hip pain.

    Science.gov (United States)

    Salar, Omer; Mushtaq, Fizza; Ahmed, Mushtaq

    2012-07-10

    Acute hip pain is a common reason for attendance to hospital. Immediate diagnoses include occult fractures, infectious and non-infectious inflammatory processes such as gout and pseudogout. Calcium pyrophosphate deposition disease (CPDD) is a rheumatological syndrome affecting articular cartilage and/or synovial fluid. It can occur as a clinical presentation (pseudogout) where calcium pyrophosphate dihydrate (CPPD) crystals are deposited within the joint space or radiographically, as chondrocalcinosis (CC), where CPPD crystals are deposited onto articular cartilages. Extraarticular manifestations of CPDD are rare. The authors report a case of CPPD deposition in the trochanteric bursa of a 35-year-old woman presenting as acute hip pain. The patient was treated successfully during arthroscopy with removal of the deposits and excision of the bursa. The patient remains well at 6 month follow-up.

  10. Simplified Citrate Anticoagulation for CRRT Without Calcium Replacement.

    Science.gov (United States)

    Broman, Marcus; Klarin, Bengt; Sandin, Karin; Carlsson, Ola; Wieslander, Anders; Sternby, Jan; Godaly, Gabriela

    2015-01-01

    Since 2012, citrate anticoagulation is the recommended anticoagulation strategy for continuous renal replacement therapy (CRRT). The main drawback using citrate as anticoagulant compared with heparin is the need for calcium replacement and the rigorous control of calcium levels. This study investigated the possibility to achieve anticoagulation while eliminating the need for calcium replacement. This was successfully achieved by including citrate and calcium in all CRRT solutions. Thereby the total calcium concentration was kept constant throughout the extracorporeal circuit, whereas the ionized calcium was kept at low levels enough to avoid clotting. Being a completely new concept, only five patients with acute renal failure were included in a short, prospective, intensely supervised nonrandomized pilot study. Systemic electrolyte levels and acid-base parameters were stable and remained within physiologic levels. Ionized calcium levels declined slightly initially but stabilized at 1.1 mmol/L. Plasma citrate concentrations stabilized at approximately 0.6 mmol/L. All postfilter ionized calcium levels were CRRT.

  11. Calcium and Iron Levels in Some Fruits and Vegetables Commonly ...

    African Journals Online (AJOL)

    , Cabbage, Pepper, Spinach, and Tomato) in each case were analysed for their Calcium and iron levels using spectrophotometric method of analysis; From the results, it was found that the concentration of Calcium was highest in spinach ...

  12. Calcium supplementation to prevent pre-eclampsia - a systematic ...

    African Journals Online (AJOL)

    Calcium supplementation to prevent pre-eclampsia - a systematic review. ... To assess the effects of calcium supplementation during pregnancy on hypertensive disorders of pregnancy and related maternal and child adverse ... Article Metrics.

  13. The effect of farmyard manure and calcium ammonium nitrate ...

    African Journals Online (AJOL)

    The effect of farmyard manure and calcium ammonium nitrate fertilisers on micronutrient density (iron, zinc, manganese, calcium and potassium) and seed yields of solanium villosum (black nightshade) and cleome gynandra (cat whiskers) on uetric nitisol.

  14. Peanut (Arachis hypogaea L.) Cultivar Response to Prohexadione Calcium

    Science.gov (United States)

    Peanut digging efficiency can be reduced if row visibility is limited by excessive vegetation. The plant growth regulator prohexadione calcium retards vegetative growth and improves row visibility by inhibiting internode elongation. In some instances, prohexadione calcium also increases pod yield....

  15. Astrocyte calcium signalling orchestrates neuronal synchronization in organotypic hippocampal slices

    Science.gov (United States)

    Sasaki, Takuya; Ishikawa, Tomoe; Abe, Reimi; Nakayama, Ryota; Asada, Akiko; Matsuki, Norio; Ikegaya, Yuji

    2014-01-01

    Astrocytes are thought to detect neuronal activity in the form of intracellular calcium elevations; thereby, astrocytes can regulate neuronal excitability and synaptic transmission. Little is known, however, about how the astrocyte calcium signal regulates the activity of neuronal populations. In this study, we addressed this issue using functional multineuron calcium imaging in hippocampal slice cultures. Under normal conditions, CA3 neuronal networks exhibited temporally correlated activity patterns, occasionally generating large synchronization among a subset of cells. The synchronized neuronal activity was correlated with astrocyte calcium events. Calcium buffering by an intracellular injection of a calcium chelator into multiple astrocytes reduced the synaptic strength of unitary transmission between pairs of surrounding pyramidal cells and caused desynchronization of the neuronal networks. Uncaging the calcium in the astrocytes increased the frequency of neuronal synchronization. These data suggest an essential role of the astrocyte calcium signal in the maintenance of basal neuronal function at the circuit level. PMID:24710057

  16. Calcium Supplements: A Risk Factor for Heart Attack?

    Science.gov (United States)

    ... factor for heart attack? I've read that calcium supplements may increase the risk of heart attack. ... D. Some doctors think it's possible that taking calcium supplements may increase your risk of a heart ...

  17. Calcium Supplements: Do They Interfere with Blood Pressure Drugs?

    Science.gov (United States)

    ... with blood pressure drugs? Is it true that calcium supplements may interact with blood pressure medications? Answers ... G. Sheps, M.D. Yes. In large amounts, calcium supplements may interact with some blood pressure medications. ...

  18. Effect of high calcium concentration influents on enhanced biological phosphorus removal process; Efecto del proceso de eliminacion biologica de fosforo en enfluentes con elevadas concentraciones de calcio

    Energy Technology Data Exchange (ETDEWEB)

    Montoya Martinez, T.; Aguado Garcia, D.; Ferrer Polo, J.

    2010-07-01

    In this work, the effect of calcium concentration in wastewater on the polyphosphate accumulating organisms (PAO) is investigated as well as its influence in PAO metabolism, specifically in the Y{sub P}O4 (ratio between phosphorus release and acetic acid uptake). For this study a sequencing batch reactor (SBR) anaerobic-aerobic was used, in which the PAO enriched biomass was exposed to different calcium concentrations in the influent wastewater. The results indicate that until a given calcium level in the influent wastewater (35 mg Ca/l) the metabolism is not affect, but higher calcium concentrations lead to significant Y{sub P}O4 decline. (Author) 18 refs.

  19. Mantle Calcium Dominates Continental Magmas

    Science.gov (United States)

    Simon, J. I.; Depaolo, D. J.; Bachmann, O.

    2009-12-01

    Trace element and isotopic compositions of continental igneous rocks are often used to model the generation and evolution of crustal magmas. Here we report new Ca isotopic measurements of crystal-poor (35%) rhyolites from the Oligocene San Juan Volcanic Field (SJVF) and Pliocene to Pleistocene tuffs from Yellowstone Caldera. Because both volcanic fields are located within the North American craton the extruded magmas could have assimilated old crustal source components with radiogenic Ca that would be clearly distinguishable from that of the mantle. New Ca data are also reported for two crustal xenoliths found within the 28.2 Ma Fish Canyon Tuff (FCT) of the SJVF that yield ɛCa values of 3.8±0.6 (2 σ, n=3) and 7.5±0.4 (2 σ, n=3), respectively. The 40Ca excesses of these possible source rocks are due to long-term in situ 40K decay and suggest that they are Precambrian in age. In contrast to the excess radiogenic Ca signatures, most Cenozoic basalts and many silicic igneous rocks from Earth yield initial ɛCa values close to zero, which indicates that the 40Ca/44Ca ratio of the Earth’s mantle is well defined and virtually invariant at the resolution of our measurements. The crystal-rich FCT, inferred to result from batholith-scale remobilization of a shallow subvolcanic magma chamber, exhibits an ɛCai value of 0.32±0.02 (2 σ, n=5) that is indistinguishable from Ca in clinopyroxene from an ultramafic xenolith that has a mantle-like ɛCai value of -0.35±0.62 (2 σ, n=2). Simple mass balance calculations indicate that Ca in the FCT is greater than ~75% mantle derived. Similar mixing models based on published Nd data for the FCT that consider the range of possible crustal source components can deviate substantially from the Ca models. At face value the Nd data indicate that the FCT magma underwent significant crustal assimilation (i.e., at least ~10% and possibly ~75% of the Nd appears to have come from an enriched source component). So even in cases where a

  20. Effect of calcium dobesilate on occurrence of diabetic macular oedema (CALDIRET study): randomised, double-blind, placebo-controlled, multicentre trial.

    Science.gov (United States)

    Haritoglou, Christos; Gerss, Joachim; Sauerland, Cristina; Kampik, Anselm; Ulbig, Michael W

    2009-04-18

    Medical treatment for diabetic retinopathy could have an important role in prevention of complications such as visual loss. We aimed to assess the effect of calcium dobesilate on occurrence of diabetic macular oedema. We undertook a randomised, double-blind, placebo-controlled, multicentre study in 40 centres in 11 countries. We enrolled outpatients with adult-onset type 2 diabetes and mild-to-moderate non-proliferative diabetic retinopathy, and randomly allocated them via sealed envelopes either calcium dobesilate (1500 mg per day) or placebo. The primary endpoint was development of clinically significant macular oedema (CSME) within a follow-up period of 5 years. Patients who dropped out of the study early were censored. Analysis was by intention to treat. We enrolled 635 patients. 324 were randomly allocated calcium dobesilate and 311 were assigned placebo. In the calcium dobesilate group, 86 patients developed CSME compared with 69 in the placebo group. Accounting for censored cases, estimated cumulative 5-year CSME probability was 35% and 28%, respectively (hazard ratio 1.32, 95% CI 0.96-1.81; p=0.0844). Adverse events did not differ between treatment groups (78 [24%] on calcium dobesilate and 90 [29%] with placebo). No relevant drug-related complications were noted. Nine patients (3%) died in the calcium dobesilate group and eight (3%) deaths were recorded on placebo. Calcium dobesilate did not reduce the risk of development of CSME.

  1. Beyond-root calcium fertilization of apple trees

    Directory of Open Access Journals (Sweden)

    Kazimierz Słowik

    2013-12-01

    Full Text Available Investigations were performed in the period 1977-1979 on the apple tree cultivar 'Fantazja', on rootstock A 2, M 7 and MM 106 on the effect of spraying with solution containing calcium on the incidence of bitter pit, breakdown, calcium content in the fruit flesh and other features of the fruits. Threefold spraying with calcium nitrate, calcium chloride or Anti-Stipp significantly limited the appearance of bitter pit and breakdown.

  2. Calcium Intake in Elderly Australian Women Is Inadequate

    Directory of Open Access Journals (Sweden)

    Colin W. Binns

    2010-09-01

    Full Text Available The role of calcium in the prevention of bone loss in later life has been well established but little data exist on the adequacy of calcium intakes in elderly Australian women. The aim of this study was to compare the dietary intake including calcium of elderly Australian women with the Australian dietary recommendation, and to investigate the prevalence of calcium supplement use in this population. Community-dwelling women aged 70–80 years were randomly recruited using the Electoral Roll for a 2-year protein intervention study in Western Australia. Dietary intake was assessed at baseline by a 3-day weighed food record and analysed for energy, calcium and other nutrients. A total of 218 women were included in the analysis. Mean energy intake was 7,140 ± 1,518 kJ/day and protein provided 19 ± 4% of energy. Mean dietary calcium intake was 852 ± 298 mg/day, which is below Australian recommendations. Less than one quarter of women reported taking calcium supplements and only 3% reported taking vitamin D supplements. Calcium supplements by average provided calcium 122 ± 427 mg/day and when this was taken into account, total calcium intake increased to 955 ± 504 mg/day, which remained 13% lower than the Estimated Average Requirement (EAR, 1,100 mg/day for women of this age group. The women taking calcium supplements had a higher calcium intake (1501 ± 573 mg compared with the women on diet alone (813 ± 347 mg. The results of this study indicate that the majority of elderly women were not meeting their calcium requirements from diet alone. In order to achieve the recommended dietary calcium intake, better strategies for promoting increased calcium, from both diet and calcium supplements appears to be needed.

  3. Modulation of L-type calcium channels by sodium ions.

    OpenAIRE

    Balke, C W; Wier, W G

    1992-01-01

    It is universally believed that the removal of external sodium ions is without effect on calcium current. We now report that in enzymatically isolated guinea pig ventricular cells, the replacement of external sodium ions with certain other cations causes a 3- to 6-fold increase in peak L-type calcium current. The increase in current is reversibly blocked by L-type calcium-channel antagonists, not mediated by changes in internal calcium, and is inhibited by intracellular 5'-adenylyl imidodipho...

  4. How calcium makes endocytic receptors attractive

    DEFF Research Database (Denmark)

    Andersen, Christian B F; Moestrup, Søren K

    2014-01-01

    'lynchpin' that stabilizes favorable positioning of ligand-attractive receptor residues. In addition to explaining how calcium depletion can cause ligand-receptor dissociation, the new data add further insight into how acidification contributes to dissociation through structural changes that affect...

  5. Drying and Rehydration of Calcium Alginate Gels

    NARCIS (Netherlands)

    Vreeker, R.; Li, L.; Fang, Y.; Appelqvist, I.; Mendes, E.

    2008-01-01

    In this paper, we study the rehydration properties of air-dried calcium alginate gel beads. Rehydration is shown to depend on alginate source (i.e. mannuronic to guluronic acid ratio) and the salt concentration in the rehydration medium. Rehydration curves are described adequately by the empirical

  6. Pharmacological analysis of calcium antagonist receptors

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, I.J.

    1987-01-01

    This work focuses on two aspects of the action of calcium antagonist drugs, namely, the interaction of drugs with receptors for verapamil-like calcium antagonists, and the interactions of drugs with voltage-sensitive calcium fluxes in rat brain synaptosomes. From binding studies I have found that the ligand of choice for labeling the verapamil receptor is (-)(/sup 3/H)desmethoxy-verapamil. This drug labels potently, reversibly and stereoselectively two receptors in membranes prepared from rat brain and rabbit skeletal muscle tissues. In equilibrium studies dihydropyridine calcium antagonists interact in a non-competitive fashion, while many non-DHPs are apparently competitive. In-depth kinetic studies in skeletal muscle membranes indicate that the two receptors are linked in a negative heterotropic fashion, and that low-affinity binding of (-) (/sup 3/H)desmethoxy-verapamil may be to the diltiazem receptor. However, these studies were not able to distinguish between the hypothesis that diltiazem binds to spatially separate, allosterically coupled receptors, and the hypothesis that diltiazem binds to a subsite of the verapamil receptor.

  7. Physicochemical characterization of zinc-substituted calcium ...

    Indian Academy of Sciences (India)

    On the contrary, no changes of the crystallinity were observed for the brushite doped with Zn ions. Morphology of attained powders, visualized using scanningelectron microscopy exemplified structural changes between calcium phosphates conjugated with zinc ions. Many authors report that the addition of small amounts of ...

  8. Simulating cement microstructural evolution during calcium leaching

    NARCIS (Netherlands)

    Patel, R.A.; Perko, J.; Jacques, D.; De Schutter, G.; Van Breugel, K.; Ye, G.

    2014-01-01

    Calcium leaching is one of the important degradation mechanisms causing dissolution of the crystalline phases such as, AFm, portlandite increasing capillary porosity. Further it leads to decalcification of an amorphous C-S-H phase causing increase in the gel porosity and in turn degrading the long

  9. Serum Calcium, Inorganic Phosphates and some Haematological ...

    African Journals Online (AJOL)

    Objectives: Sickle cell disease has long been associated with bone deformities and pain. Mineral salts such as calcium and inorganic phosphate are critical in bone formation and metabolism. This investigation was designed to study the serum concentration of these minerals as well as some haematological parameters in ...

  10. 21 CFR 582.5217 - Calcium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phosphate. 582.5217 Section 582.5217 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  11. 21 CFR 582.5210 - Calcium oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium oxide. 582.5210 Section 582.5210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements...

  12. 21 CFR 582.5223 - Calcium pyrophosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium pyrophosphate. 582.5223 Section 582.5223 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  13. 21 CFR 582.5212 - Calcium pantothenate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium pantothenate. 582.5212 Section 582.5212 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  14. 21 CFR 582.5230 - Calcium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium sulfate. 582.5230 Section 582.5230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  15. 21 CFR 582.5195 - Calcium citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.5195 Section 582.5195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  16. 21 CFR 582.5201 - Calcium glycerophosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium glycerophosphate. 582.5201 Section 582.5201 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  17. CALCIUM DEFICIENCY AND CAUSATION OF RICKETS IN ...

    African Journals Online (AJOL)

    hi-tech

    2005-03-03

    Mar 3, 2005 ... Objective: To assess the role of calcium in the development of clinical rickets among. Ethiopian children coming to Jimma Specialised Hospital outpatient, department. Design: Case control study. Settings: Jimma Specialised Teaching Hospital and surrounding urban and rural community in the catchment ...

  18. An improved calcium chloride method preparation and ...

    African Journals Online (AJOL)

    In this paper, we have reported a modified method for preparation and transformation of competent cells. This modified method, improved from a classical protocol, has made some modifications on the concentration of calcium chloride and competent bacteria solution, rotation speed in centrifugation and centrifugation time.

  19. Biocompatibility of bio based calcium carbonate nanocrystals ...

    African Journals Online (AJOL)

    Material and Methods: Transmission and field emission scanning electron microscopy (TEM and FESEM) were used for the characterisation of CaCO3 nanocrystals. Cytotoxicity and genotoxic effect of calcium carbonate nanocrystals in cultured mouse embryonic fibroblast NIH 3T3 cell line using various bioassays including ...

  20. Calcium carbonate precipitation by different bacterial strains ...

    African Journals Online (AJOL)

    Bacteria are capable of performing metabolic activities which thereby promote precipitation of calcium carbonate in the form of calcite. In this study, it is shown that microbial mineral precipitation was a result of metabolic activities of some specific microorganisms. Concrete microorganisms were used to improve the overall ...

  1. Fabrication and Evaluation of Rosuvastatin Calcium Fast ...

    African Journals Online (AJOL)

    Available online at http://www.tjpr.org · http://dx.doi.org/10.4314/tjpr.v14i11.2. Original ... Revised accepted: 6 October 2015. Abstract. Purpose: To formulate fast-disintegrating tablets (FDT) of rosuvastatin calcium (RST) using β- ... promote dissolution, absorption and ultimately bioavailability thereby reducing particle size or.

  2. Calcium enhances cadmium tolerance and decreases cadmium ...

    African Journals Online (AJOL)

    These results suggest that cadmium uptake in lettuce plants is negatively associated with the presence of calcium in the culture medium, maybe due to a competition between these two cations for binding and absorption sites in roots. In conclusion, the results suggest that fertilization with Ca2+ appears to be a promising ...

  3. Osteophagia provide giraffes with phosphorus and calcium?

    Science.gov (United States)

    Bredin, I P; Skinner, J D; Mitchell, G

    2008-03-01

    The daily requirement for calcium and phosphorus by giraffes to sustain the growth and maintenance of their skeletons is large. The source of sufficient calcium is browse. The source of necessary phosphorus is obscure, but it could be osteophagia, a frequently observed behaviour in giraffes. We have assessed whether bone ingested as a result of osteophagia can be digested in the rumen. Bone samples from cancellous (cervical vertebrae) and dense bones (metacarpal shaft) were immersed in the rumens of five sheep, for a period of up to 30 days, and the effect compared to immersion in distilled water and in artificial saliva for 30 days. Distilled water had no effect on the bones. Dense bone samples were softened by exposure to the saliva and rumen fluid, but did not lose either calcium or phosphorus. In saliva and rumen fluid the cancellous bone samples also softened, and their mass and volume decreased as a result of exposure to saliva, but in neither fluid did they lose significant amounts of calcium and phosphorus. We conclude that although saliva and rumen fluid can soften ingested bones, there is an insignificant digestion of bones in the rumen.

  4. [Intra-cystic renal calcium milk].

    Science.gov (United States)

    Meunier, B; Médart, L; Massart, J P; Collignon, L

    2015-02-01

    Intra-cystic renal calcium milk is a rare entity. The authors report a clinical case, and describe the radiographic and tomodensitometric appearances. This 50 year old patient has been followed up for more than ten years for urinary lithiasis with recurrent pain.

  5. Isolation and characterization of biogenic calcium carbonate ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 2. Isolation and characterization of biogenic calcium carbonate/phosphate from oral bacteria and their adhesion studies on YSZ-coated titanium substrate for dental implant application. GOBI SARAVANAN KALIARAJ KAMALAN KIRUBAHARAN G ...

  6. 76 FR 71459 - Prohexadione Calcium; Pesticide Tolerances

    Science.gov (United States)

    2011-11-18

    ... requested that 40 CFR 180.547 be amended by establishing tolerances for residues of the plant growth... subgroups of consumers, including infants and children. Prohexadione calcium is not acutely toxic by the..., and kidneys were the target organ for toxicity in the dogs. Following repeated dermal exposures for 28...

  7. Effect of Ultrasound on Calcium Carbonate Crystallization

    NARCIS (Netherlands)

    Wagterveld, R.M.

    2013-01-01

    Scaling comprises the formation of hard mineral deposits on process or membrane equipment and calcium carbonate is the most common scaling salt. Especially in reverse osmosis (RO) membrane systems, scale formation has always been a serious limitation, causing flux decline, membrane degradation, loss

  8. Exploring the calcium isotope signature of

    NARCIS (Netherlands)

    Hippler, D.; Witbaard, R.; van Aken, H.M.; Buhl, D.; Immenhauser, A.

    2013-01-01

    The calcium-isotope composition (delta Ca-44/40) of the aragonitic bivalve Arctica islandica grown in laboratory and field cultures was investigated in terms of environmental and biological controls to explore its potential as a palaeoceanographic proxy. While we found no significant effect of

  9. Thermoluminescence dosimetry of rare earth doped calcium ...

    Indian Academy of Sciences (India)

    The thermoluminescence (TL) properties of calcium aluminate (CaAl2O4) doped with different rare earth ions have been studied and their suitability for radiation dosimetry applications is discussed. It is observed that monocalcium aluminate doped with cerium is a good dosimeter having linear response up to about 4 kGy of ...

  10. Effects of Calcium Ion, Calpains, and Calcium Channel Blockers on Retinitis Pigmentosa

    Directory of Open Access Journals (Sweden)

    Mitsuru Nakazawa

    2011-01-01

    Full Text Available Recent advances in molecular genetic studies have revealed many of the causative genes of retinitis pigmentosa (RP. These achievements have provided clues to the mechanisms of photoreceptor degeneration in RP. Apoptosis is known to be a final common pathway in RP and, therefore, a possible therapeutic target for photoreceptor rescue. However, apoptosis is not a single molecular cascade, but consists of many different reactions such as caspase-dependent and caspase-independent pathways commonly leading to DNA fractionation and cell death. The intracellular concentration of calcium ions is also known to increase in apoptosis. These findings suggest that calpains, one of the calcium-dependent proteinases, play some roles in the process of photoreceptor apoptosis and that calcium channel antagonists may potentially inhibit photoreceptor apoptosis. Herein, the effects of calpains and calcium channel antagonists on photoreceptor degeneration are reviewed.

  11. In vivo optoacoustic monitoring of calcium activity in the brain (Conference Presentation)

    Science.gov (United States)

    Deán-Ben, Xose Luís.; Gottschalk, Sven; Sela, Gali; Lauri, Antonella; Kneipp, Moritz; Ntziachristos, Vasilis; Westmeyer, Gil G.; Shoham, Shy; Razansky, Daniel

    2017-03-01

    Non-invasive observation of spatio-temporal neural activity of large neural populations distributed over the entire brain of complex organisms is a longstanding goal of neuroscience [1,2]. Recently, genetically encoded calcium indicators (GECIs) have revolutionized neuroimaging by enabling mapping the activity of entire neuronal populations in vivo [3]. Visualization of these powerful sensors with fluorescence microscopy has however been limited to superficial regions while deep brain areas have so far remained unreachable [4]. We have developed a volumetric multispectral optoacoustic tomography platform for imaging neural activation deep in scattering brains [5]. The developed methodology can render 100 volumetric frames per second across scalable fields of view ranging between 50-1000 mm3 with respective spatial resolution of 35-150µm. Experiments performed in immobilized and freely swimming larvae and in adult zebrafish brains expressing the genetically-encoded calcium indicator GCaMP5G demonstrated, for the first time, the fundamental ability to directly track neural dynamics using optoacoustics while overcoming the depth barrier of optical imaging in scattering brains [6]. It was further possible to monitor calcium transients in a scattering brain of a living adult transgenic zebrafish expressing GCaMP5G calcium indicator [7]. Fast changes in optoacoustic traces associated to GCaMP5G activity were detectable in the presence of other strongly absorbing endogenous chromophores, such as hemoglobin. The results indicate that the optoacoustic signal traces generally follow the GCaMP5G fluorescence dynamics and further enable overcoming the longstanding optical-diffusion penetration barrier associated to scattering in biological tissues [6]. The new functional optoacoustic neuroimaging method can visualize neural activity at penetration depths and spatio-temporal resolution scales not covered with the existing neuroimaging techniques. Thus, in addition to the well

  12. Altered calcium metabolism: the probable major biochemical lesion ...

    African Journals Online (AJOL)

    These data are suggestive of altered calcium metabolism impairing cell membrane stabilization, the vasorelaxing effect of calcium and cell signaling. Altered calcium metabolism may be the major biochemical lesion underlying many pathological and clinical states of lead toxicity. Journal of Biomedical Investigation Vol.

  13. Dietary calcium intake and sunlight exposure among children aged ...

    African Journals Online (AJOL)

    Nutritional rickets can be caused by either or both calcium and vitamin D deficiencies, and can frequently occur in Africa. In Ethiopia, limited evidence exists regarding the calcium intake of children and their sunlight exposure practices. The purpose of this study was to assess information regarding dietary calcium intake and ...

  14. Magnesium: Origin and role in calcium-treated inclusions

    CSIR Research Space (South Africa)

    Pistorius, CP

    2006-08-01

    Full Text Available in calcium-treated steel is not fully clear, nor is the origin of the several percent of magnesium oxide that is often present in calcium-treated inclusions. To study this, steel was sampled after calcium treatment at an industrial steel plant...

  15. Enhanced expression of a calcium-dependent protein kinase from ...

    Indian Academy of Sciences (India)

    Among the downstream targets of calcium in plants, calcium-dependent protein kinases (CDPKs) form an interesting class of kinases which are activated by calcium binding. They have been implicated in a diverse array of responses to hormonal and environmental stimuli. In order to dissect the role of CDPKs in the moss ...

  16. Serum Calcium Level is Associated with Lipids in Young Nigerian ...

    African Journals Online (AJOL)

    cholesterol (VLDL‑c), total lipids and total calcium were assayed in 160 young women (110 OCP users and 50 controls) using colorimetric ... Emokpae and Uadia: Serum calcium correlates with lipid levels in women using low dose oral contraceptive pills ..... by increasing calcium absorption from diet in the intestine.

  17. Transfected parvalbumin alters calcium homeostasis in teratocarcinoma PCC7 cells

    DEFF Research Database (Denmark)

    Müller, B K; Kabos, P; Belhage, B

    1996-01-01

    transfected. Parvalbumin-transfected and mock-transfected cells were loaded with the calcium indicator fura-2 and were exposed, in the same dish, to different concentrations of the calcium ionophore A23187 or to KCI. The results show that parvalbumin-transfected PCC7 cells had much better calcium buffering...... capacity than control cells....

  18. Interactions of genotype, housing and dietary calcium in layer ...

    African Journals Online (AJOL)

    uzivatel

    2016-08-31

    Aug 31, 2016 ... Castillo, C., Cuca, M., Pro, A., González, M. & Morales, E., 2004. Biological and economic optimum level of calcium in white leghorn laying hens. Poult. Sci. 83, 868-872. Cheng, T.K. & Coon, C.N., 1990. Effect of calcium source, particle size, limestone solubility in vitro and calcium intake level on layer bone ...

  19. Transfected parvalbumin alters calcium homeostasis in teratocarcinoma PCC7 cells

    DEFF Research Database (Denmark)

    Müller, B K; Kabos, P; Belhage, B

    1996-01-01

    transfected. Parvalbumin-transfected and mock-transfected cells were loaded with the calcium indicator fura-2 and were exposed, in the same dish, to different concentrations of the calcium ionophore A23187 or to KCI. The results show that parvalbumin-transfected PCC7 cells had much better calcium buffering...

  20. Effect of nutrient calcium on the cell wall composition and ...

    African Journals Online (AJOL)

    The effect of calcium in the nutrient medium on kikuyu grass (Pennisetum clandestinum Hochst), grown in a solution culture, was investigated. Calcium had no effect on the lignin content of leaf material, but decreased the lignin content per unit stem cell wall. Calcium appeared to have no significant effect on either the ...