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Sample records for abnormal calcium cycling

  1. [Microbial geochemical calcium cycle].

    PubMed

    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.

  2. Abnormal calcium homeostasis in peripheral neuropathies

    PubMed Central

    Fernyhough, Paul; Calcutt, Nigel A.

    2010-01-01

    Abnormal neuronal calcium (Ca2+) homeostasis has been implicated in numerous diseases of the nervous system. The pathogenesis of two increasingly common disorders of the peripheral nervous system, namely neuropathic pain and diabetic polyneuropathy, has been associated with aberrant Ca2+ channel expression and function. Here we review the current state of knowledge regarding the role of Ca2+ dyshomeostasis and associated mitochondrial dysfunction in painful and diabetic neuropathies. The central impact of both alterations of Ca2+ signalling at the plasma membrane and also intracellular Ca2+ handling on sensory neuron function is discussed and related to abnormal endoplasmic reticulum performance. We also present new data highlighting sub-optimal axonal Ca 2+ signalling in diabetic neuropathy and discuss the putative role for this abnormality in the induction of axonal degeneration in peripheral neuropathies. The accumulating evidence implicating Ca2+ dysregulation with both painful and degenerative neuropathies, along with recent advances in understanding of regional variations in Ca2+ channel and pump structures, makes modulation of neuronal Ca2+ handling an increasingly viable approach for therapeutic interventions against the painful and degenerative aspects of many peripheral neuropathies. PMID:20034667

  3. Abnormalities of serum calcium and magnesium

    USDA-ARS?s Scientific Manuscript database

    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...

  4. Unusual and abnormal canine estrous cycles.

    PubMed

    Meyers-Wallen, V N

    2007-12-01

    Preovulatory serum progesterone concentrations are used to estimate the day of LH peak (day 0), not only to accurately time insemination and predict parturition, but to identify abnormal or unusual estrous cycles due to ovarian dysfunction. Early identification of these disorders is of therapeutic and economic importance. This review discusses anovulation, slow preovulatory progesterone rise, "split heat", insufficient luteal phase, and persistent estrus in the bitch. Some of these were temporary dysfunctions; with appropriate breeding management, pregnancy can be achieved. However, in other cases, these were signs of severe, permanent ovarian dysfunction associated with infertility, with potentially lethal sequelae.

  5. An Intracellular Calcium Oscillations Model Including Mitochondrial Calcium Cycling

    NASA Astrophysics Data System (ADS)

    Shi, Xiao-Min; Liu, Zeng-Rong

    2005-12-01

    Calcium is a ubiquitous second messenger. Mitochondria contributes significantly to intracellular Ca2+ dynamics. The experiment of Kaftan et al. [J. Biol. Chem. 275(2000) 25465] demonstrated that inhibiting mitochondrial Ca2+ uptake can reduce the frequency of cytosolic Ca2+ concentration oscillations of gonadotropes. By considering the mitochondrial Ca2+ cycling we develop a three-variable model of intracellular Ca2+ oscillations based on the models of Atri et al. [Biophys. J. 65 (1993) 1727] and Falcke et al. [Biophys. J. 77 (1999) 37]. The model reproduces the fact that mitochondrial Ca2+ cycling increases the frequency of cytosolic Ca2+ oscillations, which accords with Kaftan's results. Moreover the model predicts that when the mitochondria overload with Ca2+, the cytosolic Ca2+ oscillations vanish, which may trigger apoptosis.

  6. Effects of dietary vitamin D on calcium and magnesium levels in mice with abnormal calcium metabolism

    SciTech Connect

    Spurlock, B.G.; West, W.L.; Knight, E.M. )

    1991-03-11

    In previous studies vitamin D has been used to induce cardiac calcium overload in laboratory animals. Interrelationships between calcium and magnesium metabolism are also documented. The authors have investigated the effect of varying vitamin D in the diet on calcium and magnesium levels in plasma, kidney and heart of DBA mice which exhibit genetic abnormalities in cardiac calcium metabolism. Weanling DBA mice were maintained for 28 days on an AIN-76 diet containing either 1,000 I.U. of vitamin D{sub 3} per kg of diet (control); 4,000 I.U. of vitamin D{sub 3} per kg of diet; or no vitamin D. When compared to controls, supplemented animals showed significantly higher plasma magnesium, kidney calcium and kidney magnesium levels; animals receiving the vitamin D-deficient diet exhibited increases in cardiac calcium levels. The authors results support previous findings that vitamin D deficiency increases cardiac calcium uptake and suggest a possible role of vitamin D in magnesium metabolism.

  7. Interneuronal calcium channel abnormalities in posttraumatic epileptogenic neocortex

    PubMed Central

    Faria, Leonardo C.; Parada, Isabel; Prince, David A.

    2012-01-01

    Decreased release probability (Pr) and increased failure rate for monosynaptic inhibitory postsynaptic currents (IPSCs) indicate abnormalities in presynaptic inhibitory terminals on pyramidal (Pyr) neurons of the undercut (UC) model of posttraumatic epileptogenesis. These indices of inhibition are normalized in high [Ca++] ACSF, suggesting dysfunction of Ca2+ channels in GABAergic terminals. We tested this hypothesis using selective blockers of P/Q and N-type Ca2+ channels whose activation underlies transmitter release in cortical inhibitory terminals. Pharmacologically isolated monosynaptic IPSCs were evoked in layer V Pyr cells by extracellular stimuli in adult rat sensorimotor cortical slices. Local perfusion of 0.2/1 μM ω-agatoxin IVa and/or 1 μM ω-conotoxin GVIA was used to block P/Q and N-type calcium channels, respectively. In control layer V Pyr cells, peak amplitude of eIPSCs was decreased by ~50% after treatment with either 1 μM ω-conotoxin GVIA or 1 μM ω-agatoxin IVa. In contrast, there was a lack of sensitivity to 1 μM ω-conotoxin GVIA in UCs. Immunocytochemical results confirmed decreased perisomatic density of N-channels on Pyr cells in UCs. We suggest that decreased calcium influx via N-type channels in presynaptic GABAergic terminals is a mechanism contributing to decreased inhibitory input onto layer V Pyr cells in this model of cortical posttraumatic epileptogenesis. PMID:22172650

  8. Cardiac alternans and intracellular calcium cycling

    PubMed Central

    Edwards, Joshua N.; Blatter, Lothar A.

    2014-01-01

    Cardiac alternans refers to a condition in which there is a periodic beat-to-beat oscillation in electrical activity and the strength of cardiac muscle contraction at a constant heart rate. Clinically, cardiac alternans occurs in settings that are typical for cardiac arrhythmias and has been causally linked to these conditions. At the cellular level, alternans is defined as beat-to-beat alternations in contraction amplitude (mechanical alternans), action potential duration (APD; electrical or APD alternans), and Ca2+ transient amplitude (Ca2+ alternans). The cause of alternans is multifactorial, however alternans always originate from disturbances of the bi-directional coupling between membrane voltage (Vm) and intracellular calcium ([Ca2+]i). Bi-directional coupling refers to the fact that in cardiac cells, Vm depolarization and the generation of action potentials cause the elevation of [Ca2+]i that is required for contraction (a process referred to as excitation-contraction coupling), the changes of [Ca2+]i on the other hand control Vm because important membrane currents are Ca2+-dependent. Evidence is mounting that alternans is ultimately caused by disturbances of cellular Ca2+ signaling. Here we review how two key factors of cardiac cellular Ca2+ cycling - the release of Ca2+ from internal stores and the capability of clearing the cytosol from Ca2+ after each beat - determine the conditions under which alternans occurs. The contributions from key Ca2+ handling proteins - surface membrane channels, ion pumps and transporters, and internal Ca2+ release channels - are discussed. PMID:25040398

  9. Calcium and calcium isotope changes during carbon cycle perturbations at the end-Permian

    NASA Astrophysics Data System (ADS)

    Komar, N.; Zeebe, R. E.

    2016-01-01

    Negative carbon and calcium isotope excursions, as well as climate shifts, took place during the most severe mass extinction event in Earth's history, the end-Permian (˜252 Ma). Investigating the connection between carbon and calcium cycles during transient carbon cycle perturbation events, such as the end-Permian, may help resolve the intricacies between the coupled calcium-carbon cycles, as well as provide a tool for constraining the causes of mass extinction. Here we identify the deficiencies of a simplified calcium model employed in several previous studies, and we demonstrate the importance of a fully coupled carbon cycle model when investigating the dynamics of carbon and calcium cycling. Simulations with a modified version of the Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir model, which includes a fully coupled carbon-calcium cycle, indicate that increased weathering rates and ocean acidification (potentially caused by Siberian Trap volcanism) are not capable of producing trends observed in the record, as previously claimed. Our model results suggest that combined effects of carbon input via Siberian Trap volcanism (12,000 Pg C), the cessation of biological carbon export, and variable calcium isotope fractionation (due to a change in the seawater carbonate ion concentration) represents a more plausible scenario. This scenario successfully reconciles δ13C and δ44Ca trends observed in the sediment record, as well as the proposed warming of >6°C.

  10. Calcium and calcium isotope changes during carbon cycle perturbations at the end-Permian

    NASA Astrophysics Data System (ADS)

    Komar, Nemanja; Zeebe, Richard

    2016-04-01

    Negative carbon and calcium isotope excursions, as well as climate shifts, took place during the most severe mass extinction event in Earth's history, the end-Permian (˜252 Ma). Investigating the connection between carbon and calcium cycles during transient carbon cycle perturbation events, such as the end-Permian, may help resolve the intricacies between the coupled calcium-carbon cycles, as well as provide a tool for constraining the causes of mass extinction. Here, we identify the deficiencies of a simplified calcium model employed in several previous studies and we demonstrate the importance of a fully coupled carbon-cycle model when investigating the dynamics of carbon and calcium cycling. Simulations with a modified version of the LOSCAR model, which includes a fully coupled carbon-calcium cycle, indicate that increased weathering rates and ocean acidification (potentially caused by Siberian Trap volcanism) are not capable of producing trends observed in the record, as previously claimed. Our model results suggest that combined effects of carbon input via Siberian Trap volcanism (12,000 Pg C), the cessation of biological carbon export, and variable calcium isotope fractionation (due to a change in the seawater carbonate ion concentration) represents a more plausible scenario. This scenario successfully reconciles δ13C and δ44Ca trends observed in the sediment record, as well as the proposed warming of >6oC.

  11. Calcium, a Cell Cycle Commander, Drives Colon Cancer Cell Diffpoptosis.

    PubMed

    Abd-Rabou, Ahmed A

    2017-03-01

    The story of the cell commonder, calcium, reaches into all corners of the cell and controls cell proliferation, differentiation, function, and even death. The calcium-driven eukaryotic revolution is one of the great turning points in the life history, happened about two billion years later when it was converted from a dangerous killer that had to be kept out of cell into the cell master which drives the cell. This review article will take the readers to a tour of tissues chosen to best show the calcium's many faces (proliferator, differentiator, and killer). The reader will first see calcium and its many helpers, such as the calcium-binding signaler protein calmodulin, directing the key events of the cell cycle. Then the tour will move onto the colon to show calcium driving the proliferation of progenitor cells, then the differentiation and ultimately the programmed death of their progeny. Moreover, the reader will learn of the striking disabling and bypassing of calcium-dependent control mechanisms during carcinogenesis. Finally, recommendations should be taken from the underlying mechanisms through which calcium masters the presistance, progression, and even apoptosis of colorectal cancer cells. Thus, this could be of great interest for designing of chemoprevention protocols.

  12. Action potential dynamics explain arrhythmic vulnerability in human heart failure: a clinical and modeling study implicating abnormal calcium handling.

    PubMed

    Narayan, Sanjiv M; Bayer, Jason D; Lalani, Gautam; Trayanova, Natalia A

    2008-11-25

    The purpose of this study was to determine whether abnormalities of calcium cycling explain ventricular action potential (AP) oscillations and cause electrocardiogram T-wave alternans (TWA). Mechanisms explaining why heart failure patients are at risk for malignant ventricular arrhythmias (ventricular tachycardia [VT]/ventricular fibrillation [VF]) are unclear. We studied whether oscillations in human ventricular AP explain TWA and predict VT/VF, and used computer modeling to suggest potential cellular mechanisms. We studied 53 patients with left ventricular ejection fraction 28 +/- 8% and 18 control subjects. Monophasic APs were recorded in the right ventricle (n = 62) and/or left ventricle (n = 9) at 109 beats/min. Alternans of AP amplitude, computed spectrally, had higher magnitude in study patients than in controls (p = 0.03), particularly in AP phase II (p = 0.02) rather than phase III (p = 0.10). The AP duration and activation restitution (n = 11 patients) were flat at 109 beats/min and did not explain TWA. In computer simulations, only reduced sarcoplasmic reticulum calcium uptake explained our results, causing calcium oscillations, AP amplitude alternans, and TWA that were all abolished by calcium clamping. On prospective follow-up for 949 +/- 553 days, 17 patients had VT/VF. The AP amplitude alternans predicted VT/VF (p = 0.04), and was 78% concordant with simultaneous TWA (p = 0.003). Patients with systolic dysfunction show ventricular AP amplitude alternans that prospectively predicted VT/VF. Alternans in AP amplitude, but not variations in AP duration or conduction, explained TWA at < or =109 beats/min. In computer models, these findings were best explained by reduced sarcoplasmic reticulum calcium uptake. Thus, in heart failure patients, in vivo AP alternans may reflect cellular calcium abnormalities and provide a mechanistic link with VT/VF.

  13. The role of the calcium-sensing receptor in disorders of abnormal calcium handling and cardiovascular disease.

    PubMed

    Toka, Hakan R; Pollak, Martin R

    2014-09-01

    The calcium-sensing receptor (CaSR) has a central role in parathyroid gland function. Genetic alterations in CaSR are well known to cause inherited forms of abnormal calcium homeostasis. This review focuses on studies investigating the role of CaSR in common disorders of abnormal calcium handling and in cardiovascular calcification. Genetic population studies tested the association of common allelic CASR variants with serum and urine calcium levels, kidney stone disease, primary hyperparathyroidism and bone mineral density. The results of these association studies suggested either minor or no effects of CASR variants in these phenotypes. Decreased expression of CaSR was associated with the etiology of cardiovascular calcification in individuals with advanced chronic kidney disease. Ionized calcium plays a central role in the physiology of many organ systems and disease states, but the roles of CaSR other than as illustrated by Mendelian forms of CaSR dysfunction remain unclear. The contributions of CaSR to bone mineral homeostasis, vascular calcification and other forms of cardiovascular disease need further investigation.

  14. Life cycle benefits of calcium silicate replacements

    SciTech Connect

    Cabrera, J.G.; Woolley, G.R.

    1996-12-31

    The most universal of all binders, produced in huge quantities worldwide, is Portland cement. Following introduction in 1824 by Joseph Aspin, it has quite properly enjoyed popular appeal with craftsmen, architects and engineers for its bonding properties. The manufacture of cement relies largely on primary minerals for feedstock and depends heavily on carboniferous fuels for production. Naturally occurring minerals have similar properties as a binder and have been used in their own right or as partial replacements for cement. Likewise, secondary products recovered from modern manufacturing or energy production processes also have the potential to replace in part a proportion of cement. Life cycle analysis of cement production supports the proposition that large quantities of fossil fuel and primary minerals are being unnecessarily used in situations where alternative replacements are available and frequently placed to waste. This paper considers the implications of cement production on a sustainable environment. It argues that, contrary to some opinions, partial replacement of cement with secondary wastes which have potential cementitious properties can enhance and improve structures which otherwise would include only Portland cement as the binder. Acceptance of this argument would leave massive quantities of primary minerals untouched and reduce the amount of fossil fuels demanded of cement production on the present scale.

  15. High-calcium exposure to frog heart: a simple model representing hypercalcemia-induced ECG abnormalities

    PubMed Central

    KAZAMA, Itsuro

    2016-01-01

    By simply adding a high concentration of calcium solution to the surface of the bullfrog heart, we reproduced electrocardiogram (ECG) abnormalities representing those observed in hypercalcemia, such as Osborn waves and shortening of the QT interval. The rise in extracellular calcium concentration may have activated the outward potassium currents during phase 3 of the action potential, and thus decreased its duration. In addition to the known decrease in the duration of phase 2, such changes in phase 3 were also likely to contribute to the shortening of the QT interval. The dual recordings of the action potential in cardiomyocytes and the ECG waves enabled us to demonstrate the mechanisms of ECG abnormalities induced by hypercalcemia. PMID:27773880

  16. High-calcium exposure to frog heart: a simple model representing hypercalcemia-induced ECG abnormalities.

    PubMed

    Kazama, Itsuro

    2017-01-20

    By simply adding a high concentration of calcium solution to the surface of the bullfrog heart, we reproduced electrocardiogram (ECG) abnormalities representing those observed in hypercalcemia, such as Osborn waves and shortening of the QT interval. The rise in extracellular calcium concentration may have activated the outward potassium currents during phase 3 of the action potential, and thus decreased its duration. In addition to the known decrease in the duration of phase 2, such changes in phase 3 were also likely to contribute to the shortening of the QT interval. The dual recordings of the action potential in cardiomyocytes and the ECG waves enabled us to demonstrate the mechanisms of ECG abnormalities induced by hypercalcemia.

  17. Calcium deprivation disrupts enlargement of Chara corallina cells: further evidence for the calcium pectate cycle

    PubMed Central

    Proseus, Timothy E.; Boyer, John S.

    2012-01-01

    Pectin is a normal constituent of cell walls of green plants. When supplied externally to live cells or walls isolated from the large-celled green alga Chara corallina, pectin removes calcium from load-bearing cross-links in the wall, loosening the structure and allowing it to deform more rapidly under the action of turgor pressure. New Ca2+ enters the vacated positions in the wall and the externally supplied pectin binds to the wall, depositing new wall material that strengthens the wall. A calcium pectate cycle has been proposed for these sub-reactions. In the present work, the cycle was tested in C. corallina by depriving the wall of external Ca2+ while allowing the cycle to run. The prediction is that growth would eventually be disrupted by a lack of adequate deposition of new wall. The test involved adding pectate or the calcium chelator EGTA to the Ca2+-containing culture medium to bind the calcium while the cycle ran in live cells. After growth accelerated, turgor and growth eventually decreased, followed by an abrupt turgor loss and growth cessation. The same experiment with isolated walls suggested the walls of live cells became unable to support the plasma membrane. If instead the pectate or EGTA was replaced with fresh Ca2+-containing culture medium during the initial acceleration in live cells, growth was not disrupted and returned to the original rates. The operation of the cycle was thus confirmed, providing further evidence that growth rates and wall biosynthesis are controlled by these sub-reactions in plant cell walls. PMID:22442410

  18. How abnormal calcium, phosphate, and parathyroid hormone relate to cardiovascular disease.

    PubMed

    Bro, Susanne

    2003-06-01

    Cardiovascular disease tends to develop prematurely in patients who have chronic kidney disease (CKD). The physiological changes that specifically arise from this disease likely account for the resulting high incidence of cardiovascular mortality. Recent studies indicate that abnormal calcium, phosphate, and parathyroid hormone (PTH) levels are associated with cardiovascular disease in CKD. This new evidence suggests that an intensive approach to the prevention and treatment of these imbalances may contribute to improved survival of patients with CKD.

  19. Incidences of menstrual cycle abnormalities in adolescence, and matches between the age at menarche and the development of menstrual cycle abnormalities.

    PubMed

    Art, Mercedes Juliana; Doerfler, Daniela

    2010-08-01

    In this study the clinical data of all girls who visited the ambulance for paediatric and adolescent gynaecology at the university clinic for gynaecology and obstetrics in Vienna between 2001 and 2008 because of menstrual cycle abnormalities were used (n = 255). Most frequently, the girls suffered from dysmenorrhoea (29%), tempoanomaly (24%) and metrorrhagia (19%). For 57%, it was possible to find an underlying cause, mainly (24%) a hormonal one. The therapy was in 54% of all cases hormonal. In a second step, the study analyses matches between the age at menarche and the development of menstrual cycle abnormalities. Girls with primary amenorrhoea were excluded (n = 219). The study shows that every age of menarche has its special kind of menstrual cycle abnormality. Only if the menarche had set in at the age of 16, two kinds were named with equal frequency.

  20. The link between abnormal calcium handling and electrical instability in acquired long QT syndrome--Does calcium precipitate arrhythmic storms?

    PubMed

    Němec, Jan; Kim, Jong J; Salama, Guy

    2016-01-01

    Release of Ca(2+) ions from sarcoplasmic reticulum (SR) into myocyte cytoplasm and their binding to troponin C is the final signal form myocardial contraction. Synchronous contraction of ventricular myocytes is necessary for efficient cardiac pumping function. This requires both shuttling of Ca(2+) between SR and cytoplasm in individual myocytes, and organ-level synchronization of this process by means of electrical coupling among ventricular myocytes. Abnormal Ca(2+) release from SR causes arrhythmias in the setting of CPVT (catecholaminergic polymorphic ventricular tachycardia) and digoxin toxicity. Recent optical mapping data indicate that abnormal Ca(2+) handling causes arrhythmias in models of both repolarization impairment and profound bradycardia. The mechanisms involve dynamic spatial heterogeneity of myocardial Ca(2+) handling preceding arrhythmia onset, cell-synchronous systolic secondary Ca(2+) elevation (SSCE), as well as more complex abnormalities of intracellular Ca(2+) handling detected by subcellular optical mapping in Langendorff-perfused hearts. The regional heterogeneities in Ca(2+) handling cause action potential (AP) heterogeneities through sodium-calcium exchange (NCX) activation and eventually overwhelm electrical coupling of the tissue. Divergent Ca(2+) dynamics among different myocardial regions leads to temporal instability of AP duration and - on the patient level - in T wave lability. Although T-wave alternans has been linked to cardiac arrhythmias, non-alternans lability is observed in pre-clinical models of the long QT syndrome (LQTS) and CPVT, and in LQTS patients. Analysis of T wave lability may provide a real-time window on the abnormal Ca(2+) dynamics causing specific arrhythmias such as Torsade de Pointes (TdP).

  1. Comparison of coronary calcium in firefighters with abnormal stress test findings and in asymptomatic nonfirefighters with abnormal stress test findings.

    PubMed

    Pillutla, Priya; Li, Dong; Ahmadi, Naser; Budoff, Matthew J

    2012-02-15

    Firefighters are known to have an elevated rate of sudden cardiac death compared to the general population. It is unclear whether this finding is related to underlying cardiovascular risk factors or whether firefighting inherently carries additional risk. Our objective was to determine whether Los Angeles county firefighters have higher coronary artery calcium (CAC) scores and increased atherosclerosis as determined using 64-slice cardiac, multidetector computed tomography. A total of 647 asymptomatic firefighters evaluated as a part of a wellness protocol were referred for cardiac multidetector computed tomography to evaluate abnormal exercise treadmill test findings. They were matched by age and cardiovascular risk factors, with 2,533 asymptomatic subjects undergoing cardiac computed tomography because of abnormal electrocardiographic or exercise treadmill test findings. CAC and the prevalence of obstructive coronary artery disease by vessel were derived. Finally, the predictors of CAC were analyzed using regression analysis. Of the firefighters, 49% had detectable CAC compared to 43% of controls (p = 0.015). Although the lesions were most prevalent in the left anterior descending artery in both groups, more firefighters had any left anterior descending artery stenosis compared to the controls (p <0.0001). The firefighters also had more left main coronary artery lesions than did the controls (p <0.0001). The firefighters had significantly greater CAC scores than did with the controls (p <0.001). Furthermore, the firefighters had significantly greater mean CAC scores (66 ± 8 in firefighters vs 33 ± 4 for controls, p <0.001). Firefighter status was independently associated with a 41-point increase in the CAC score (p <0.001). In conclusion, asymptomatic firefighters had more atherosclerosis and CAC than the matched controls. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Abnormal intracellular calcium homeostasis associated with vulnerability in the nerve cells from heroin-dependent rat.

    PubMed

    Liu, Xiaoshan; Wang, Guangyong; Pu, Hongwei; Jing, Hualan

    2014-07-14

    The cellular mechanisms by which opiate addiction develops with repetitive use remain largely unresolved. Intercellular calcium homeostasis is one of the most critical elements to determine neuroadaptive changes and neuronal fate. Heroin, one of the most addictive opiates, may induce neurotoxicity potentially inducing brain impairment, especially for those chronic users who get an overdose. Here we examined changes in intracellular calcium concentration ([Ca2+]i) after repeated exposure to heroin using cultured cerebral cortical neurons. Dynamic changes in [Ca2+]i indicated by fluo-3-AM were monitored using confocal laser scan microscopy, followed by cytotoxicity assessments. It showed that the cells dissociated from heroin-dependent rats had a smaller depolarization-induced [Ca2+]i responses, and a higher elevation in [Ca2+]i when challenged with a high concentration of heroin (500 μM). The restoration ability to remove calcium after washout of these stimulants was impaired. Calcium channel blocker verapamil inhibited the heroin-induced [Ca2+]i elevations as well as the heroin-induced cell damage. The relative [Ca2+]i of the nerve cells closely correlated with the number of damaged cells induced by heroin. These results demonstrate that nerve cells from heroin-dependent rats manifest abnormal [Ca2+]i homeostasis, as well as vulnerability to heroin overdose, suggesting involvement of [Ca2+]i regulation mechanisms in heroin addiction and neurotoxicity.

  3. Calcium oxalate contribution to calcium cycling in forests of contrasting nutrient status

    USGS Publications Warehouse

    Dauer, Jenny M.; Perakis, Steven S.

    2014-01-01

    Calcium oxalate (Ca oxalate) is an insoluble biomineral that forms in plants and fungi, and occurs in soils across many types of ecosystems. Assessing how Ca oxalate may shape ecosystem Ca cycling requires information on the distribution of Ca oxalate among plant biomass, detritus, and mineral soil, and how it varies with ecosystem Ca status. We compared two Douglas-fir forests of contrasting ecosystem Ca availability, and found that Ca oxalate was partitioned similarly among plant biomass, detritus and mineral soil major ecosystem compartments at both sites, and total pools of Ca oxalate were greater in the high-Ca forest. However, the proportional importance of Ca oxalate was greater in the low-Ca than high-Ca forest (18% versus 4% of actively cycling ecosystem Ca, respectively). And calcium oxalate in mineral soil, which is of particular interest as a potential long-term Ca reservoir, was a larger portion of total available Ca (exchangeable Ca plus Ca oxalate Ca) in the low-Ca site than the high-Ca site (9% versus 1% of available soil Ca, respectively). Calcium oxalate was the dominant form of Ca returned from plants to soil as leaf litterfall at the high-Ca site, yet calcium oxalate disappeared rapidly from decomposing litter (0.28 yr−1 or faster) at both sites. We conclude that accumulation of Ca oxalate in forest ecosystems appears most closely related to overall Ca supply for live biomass pools, and that the accumulation of Ca oxalate in forest floor and mineral soil is limited by rapid microbial degradation of putatively unavailable Ca oxalate.

  4. Serum DDT, age at menarche, and abnormal menstrual cycle length

    PubMed Central

    Ouyang, F; Perry, M; Venners, S; Chen, C; Wang, B; Yang, F; Fang, Z; Zang, T; Wang, L; Xu, X; Wang, X

    2005-01-01

    Background: Although dichlorodiphenyl trichloroethane (DDT) exposure is known to affect human endocrine function, few previous studies have investigated the effects of DDT exposure on age at menarche or menstrual cycle length. Methods: A cross sectional study was conducted to study the effects of DDT exposure on age at menarche and menstrual cycle length among 466 newly married, nulliparous female Chinese textile workers aged 20–34 years enrolled between 1996 and 1998. Serum was analysed for DDT and its major metabolites. Multivariate linear regression was used to estimate DDT exposure effects on age at menarche and multivariate logistic regression was used to estimate DDT exposure effects on odds of experiencing short or long cycles. Results: Relative to those in the lowest DDT quartile, the adjusted mean age at menarche was younger in those in the fourth quartile (–1.11 years). Modeled as a continuous variable, a 10 ng/g increase in serum DDT concentration was associated with an adjusted reduction in age at menarche of 0.20 years. Relative to those in the lowest DDT quartile, odds of any short cycle (<21 days) in the previous year were higher for those in the fourth quartile (odds ratio = 2.78; 95% CI 1.07 to 7.14). There were no associations between serum DDT concentrations and odds of experiencing a long cycle (>40 days). Conclusion: Results suggest that DDT exposure was associated with earlier age at menarche and increased risk of experiencing a shortened menstrual cycle. PMID:16299097

  5. Abnormal ovarian cycles as diagnosed by ultrasound and serum estradiol levels.

    PubMed

    Polan, M L; Totora, M; Caldwell, B V; DeCherney, A H; Haseltine, F P; Kase, N

    1982-03-01

    A significant portion of human infertility is presumably due to defective ovulation, including patients who fail to conceive despite medical induction of ovulation, those who fail despite repeated timely donor inseminations, and those with "infertility of unknown etiology". All point out the inadequacy of standard criteria for normal ovulation. This investigation correlates preovulatory serum estradiol and gonadotropin concentrations with dominant follicle growth measured ultrasonographically and serum progesterone levels. The data indicate a 35% incidence of cycles with significantly abnormal serum estradiol levels, decreased dominant follicle size, and abnormal progesterone levels despite biphasic basal body temperature curves and normal cycle length. If these cycles represent inadequate or abnormal ovulation, they can be distinguished from adequate cycles prior to follicle rupture and may benefit the treatment of human infertility.

  6. Influence of estrous and circadian cycles on calcium intake of the rat.

    PubMed

    Voznesenskaya, Anna; Tordoff, Michael G

    2013-03-15

    The food, water and sodium intake of laboratory rats fluctuates over the circadian and estrous cycles. Blood calcium and calcium-regulating hormones also wax and wane in response to these cycles, raising the possibility that the same might be true of calcium intake. To investigate this, we monitored the fluid intakes of female Long-Evans rats given a choice between water and 10mM CaCl2 solution for two consecutive estrous cycles. We found that calcium solution intake changed over the circadian cycle in a similar manner to water intake; the preference scores for CaCl2 solution remained stable. We did not detect any changes in calcium solution intake or preference scores during the estrous cycle despite a decrease in fluid intake at estrus. Thus, fluctuations in intake of calcium solution during the circadian cycle appear to be nonspecific and probably the result of changes in fluid balance. Estrous changes either do not influence calcium intake or their effects are masked by other factors, resulting in stable levels of calcium intake.

  7. Sulfur Cycling Mediates Calcium Carbonate Geochemistry in Modern Marine Stromatolites

    NASA Technical Reports Server (NTRS)

    Visscher, P. T.; Hoeft, S. E.; Bebout, B. M.; Reid, R. P.

    2004-01-01

    Modem marine stromatolites forming in Highborne Cay, Exumas (Bahamas), contain microbial mats dominated by Schizothrix. Although saturating concentrations of Ca2+ and CO32- exist, microbes mediate CaCO3 precipitation. Cyanobacterial photosynthesis in these stromatolites aids calcium carbonate precipitation by removal of HS+ through CO2 use. Photorespiration and exopolymer production predominantly by oxygenic phototrophs fuel heterotrophic activity: aerobic respiration (approximately 60 umol/sq cm.h) and sulfate reduction (SR; 1.2 umol SO42-/sq cm.h) are the dominant C- consuming processes. Aerobic microbial respiration and the combination of SR and H2S oxidation both facilitate CaCO3 dissolution through H+ production. Aerobic respiration consumes much more C on an hourly basis, but duel fluctuating O2 and H2 depth profiles indicate that overall, SR consumes only slightly less (0.2-0.5) of the primary production. Moreover, due to low O2 concentrations when SR rates are peaking, reoxidation of the H2S formed is incomplete: both thiosulfate and polythionates are formed. The process of complete H2S oxidation yields H+. However, due to a low O2 concentration late in the day and relatively high O2 concentrations early in the following morning, a two-stage oxidation takes place: first, polythionates are formed from H2S, creating alkalinity which coincides with CaCO3 precipitation; secondly, oxidation of polythionates to sulfate yields acidity, resulting in dissolution, etc. Vertical profiles confirmed that the pH peaked late in the afternoon (greater than 8.8) and had the lowest values (less than 7.4) early in the morning. Thus, the effect of this S-cycling through alkalinity production, followed by acidification during H2S oxidation, results in a six times stronger fluctuation in acidity than photosynthesis plus aerobic respiration accomplish. This implies that anaerobic processes play a pivotal role in stromatolite formation.

  8. Effect of a novel calcium channel blocker on abnormal nocturnal blood pressure in hypertensive patients.

    PubMed

    Kario, Kazuomi; Nariyama, Jin; Kido, Hidenori; Ando, Shin-ichi; Takiuchi, Shin; Eguchi, Kazuo; Niijima, Yawara; Ando, Toshiaki; Noda, Makoto

    2013-07-01

    The authors examined the effect of cilnidipine, a unique L/N-type calcium channel blocker, on abnormal nocturnal blood pressure (BP) dipping in Japanese hypertensive patients in the real world. The Ambulatory Blood Pressure Control and Home Blood Pressure (Morning and Evening) Lowering by N-Channel Blocker Cilnidipine (ACHIEVE-ONE), a large-scale clinical study, was designed to evaluate the effects of cilnidipine in daily medical practice. Among the study, 24-hour ambulatory BP data were obtained from 615 patients and classified according to their nocturnal dipping status as extreme dippers, dippers, nondippers, or risers. A 12-week treatment with cilnidipine significantly reduced 24-hour BP in all groups (P<.001). Changes in nocturnal systolic BP (SBP) from baseline were -17.9 mm Hg from 154.6 mm Hg in risers and -11.9 mm Hg from 142.1 mm Hg, -6.6 mm Hg from 128.5 mm Hg, and 0.1 mm Hg from 115.8 mm Hg in nondippers, dippers, and extreme dippers, respectively. Changes from baseline in nocturnal SBP reduction rate were 8.2% in risers (P<.001) but -7.0% in extreme dippers (P<.001), while no change was observed in the nighttime SBP reduction rate for the total patients (-0.2%±9.6%, P=.617). Cilnidipine partially, but significantly, restored abnormal nocturnal dipping status toward a normal dipping pattern in hypertensive patients.

  9. Cholecalciferol Plus Calcium Suppresses Abnormal PBMC Reactivity in Patients with Multiple Sclerosis

    PubMed Central

    Vieth, Reinhold; Dosch, Hans-Michael; Bar-Or, Amit; Cheung, Roy; Gagne, Donald; O'Connor, Paul; D'Souza, Cheryl; Ursell, Melanie; Burton, Jodie M.

    2011-01-01

    Context: The active metabolite of vitamin D, 1,25-dihydroxyvitamin D [1,25(OH)2D], is a potent modulator of immune cells in vitro. Objective: Our objective was to determine whether the sun-dependent nutrient, cholecalciferol, can alter disease-associated cellular immune abnormalities in patients with multiple sclerosis (MS). Design: This was an open-label, 12-month, randomized controlled trial. Setting: Patients with MS were recruited from the MS Clinic at St. Michael's Hospital, Toronto. Patients: Forty-nine patients were matched (for age, sex, disease duration, disease-modifying drug, and disability) and enrolled (treated n = 25; control n = 24). Four patients were lost to follow-up (n = 2 from each group). Intervention: Treated patients received increasing doses of cholecalciferol (4,000–40,000 IU/d) plus calcium (1200 mg/d), followed by equilibration to a moderate, physiological intake (10,000 IU/d). Control patients did not receive supplements. Main Outcome Measures: At enrollment and at 12 months, peripheral blood mononuclear cell (PBMC) proliferative responses to disease-associated, MS-relevant, and control antigens were measured, along with selected serum biochemical markers. Results: At 12 months, mean serum 25-hydroxyvitamin D [25(OH)D] concentrations were 83 ± 35 nmol/liter and 179 ± 76 nmol/liter in control and treated participants, respectively (paired t, P < 0.001). Serum 1,25(OH)2D did not differ between baseline and 1 yr. In treated patients, 12-month PBMC proliferative responses to neuron antigens myelin basic protein and exon-2 were suppressed (P = 0.002). In controls, there were no significant changes in disease-associated PBMC responsiveness. There were no significant differences between groups in levels of selected biomarkers. Interpretation: MS-associated, abnormal T cell reactivities were suppressed in vivo by cholecalciferol at serum 25(OH)D concentrations higher than 100 nmol/liter. PMID:21697250

  10. Impacts of an exotic disease and vegetation change on foliar calcium cycling in Appalachian forests.

    PubMed

    Jenkins, Michael A; Jose, Shibu; White, Peter S

    2007-04-01

    Because of the high calcium content of its foliage, Cornus florida (flowering dogwood) has been described as a calcium "pump" that draws calcium from deeper mineral soil and enriches surface soil horizons. However, over the last two decades an exotic fungal disease (dogwood anthracnose, Discula destructiva) has decimated populations of this once-common understory species. Its loss, combined with forest stand development, could alter intra-stand calcium cycling. We used data from long-term vegetation monitoring plots to examine the ecological role of C. florida in calcium cycling and to identify changes in annual foliar calcium cycling over a 20-year period between two sampling intervals, 1977-1979 (preanthracnose) and 1995-2000 (post-anthracnose). Published equations were used to estimate foliar biomass per species for five forest types: alluvial, typic cove, acid cove, oak-hickory, and oak-pine. Calcium concentrations derived from foliage samples were used to estimate annual foliar calcium production per species for understory woody stems (<20 cm dbh) and total foliar calcium production for overstory stems (> or =20 cm dbh). At a given level of soil calcium availability, C. florida foliage contained greater concentrations of calcium than three other dominant understory species (Tsuga canadensis, Acer rubrum, and Rhododendron maximum). Between 1977-1979 and 1995-2000, the annual calcium contributions of understory woody vegetation declined across all forest types, ranging from 26% in oak-pine stands to 49% in acid coves. Loss of C. florida was responsible for only 13% of this decline in oak-pine stands, but accounted for 96% of the decline in typic coves. In oak-hickory and oak-pine stands, we observed large increases in the foliar biomass of T. canadensis, a species whose calcium-poor foliage increases soil acidity. Increases in overstory foliar biomass and calcium offset understory losses in three forest types (alluvial, typic coves, and oak-pine) but not in oak

  11. Solar activity cycle and the incidence of foetal chromosome abnormalities detected at prenatal diagnosis

    NASA Astrophysics Data System (ADS)

    Halpern, Gabrielle J.; Stoupel, Eliahu G.; Barkai, Gad; Chaki, Rina; Legum, Cyril; Fejgin, Moshe D.; Shohat, Mordechai

    1995-06-01

    We studied 2001 foetuses during the period of minimal solar activity of solar cycle 21 and 2265 foetuses during the period of maximal solar activity of solar cycle 22, in all women aged 37 years and over who underwent free prenatal diagnosis in four hospitals in the greater Tel Aviv area. There were no significant differences in the total incidence of chromosomal abnormalities or of trisomy between the two periods (2.15% and 1.8% versus 2.34% and 2.12%, respectively). However, the trend of excessive incidence of chromosomal abnormalities in the period of maximal solar activity suggests that a prospective study in a large population would be required to rule out any possible effect of extreme solar activity.

  12. Renal tubular dysfunction and abnormalities of calcium metabolism in cadmium workers

    PubMed Central

    Kazantzis, George

    1979-01-01

    Tubular proteinuria is generally accepted as the critical effect following long-term, low-level exposure to cadmium as seen in an industrial environment. This effect may not be of immediate importance to the health of the individual, but the significance, in terms of long-term morbidity and mortality, of the renal tubular defect of which it is an indicator is not fully understood, and certain sequelae may have remained unrecognized due to inadequate follow-up. Follow-up studies have been performed in nine of 12 workers who were initially investigated in 1962. In six of the men exposures ranged from 28 to 45 years to cadmium sulfide dust and for shorter periods in the earlier years to cadmium oxide fume and dust. These six men had tubular proteinuria when first seen, and this has persisted in the five survivors. All six men had hypercalciuria, and two of them became recurrent stone formers. One man whose urinary calcium excretion later fell to a low level more recently developed vitamin D resistant osteomalacia. In addition, each of the six men had exhibited some, but not all, of a variety of biochemical abnormalities related to other proximal renal tubular defects, and the worker who developed osteomalacia had additional evidence of a distal tubular defect. The five survivors also have evidence of slowly progressive deterioration in glomerular function. Follow-up of this small group has shown that renal tubular dysfunction in cadmium workers may continue symptom-free for long intervals, but in a proportion of cases serious clinical effects may develop after a number of years. ImagesFIGURE 1. PMID:488032

  13. Abnormal propagation of calcium waves and ultrastructural remodeling in recessive catecholaminergic polymorphic ventricular tachycardia.

    PubMed

    Liu, Nian; Denegri, Marco; Dun, Wen; Boncompagni, Simona; Lodola, Francesco; Protasi, Feliciano; Napolitano, Carlo; Boyden, Penelope A; Priori, Silvia G

    2013-07-05

    The recessive form of catecholaminergic polymorphic ventricular tachycardia is caused by mutations in the cardiac calsequestrin-2 gene; this variant of catecholaminergic polymorphic ventricular tachycardia is less well characterized than the autosomal-dominant form caused by mutations in the ryanodine receptor-2 gene. We characterized the intracellular Ca²⁺ homeostasis, electrophysiological properties, and ultrastructural features of the Ca²⁺ release units in the homozygous calsequestrin 2-R33Q knock-in mouse model (R33Q) R33Q knock-in mouse model. We studied isolated R33Q and wild-type ventricular myocytes and observed properties not previously identified in a catecholaminergic polymorphic ventricular tachycardia model. As compared with wild-type cells, R33Q myocytes (1) show spontaneous Ca²⁺ waves unable to propagate as cell-wide waves; (2) show smaller Ca²⁺sparks with shortened coupling intervals, suggesting a reduced refractoriness of Ca²⁺ release events; (3) have a reduction of the area of membrane contact, of the junctions between junctional sarcoplasmic reticulum and T tubules (couplons), and of junctional sarcoplasmic reticulum volume; (4) have a propensity to develop phase 2 to 4 afterdepolarizations that can elicit triggered beats; and (5) involve viral gene transfer with wild-type cardiac calsequestrin-2 that is able to normalize structural abnormalities and to restore cell-wide calcium wave propagation. Our data show that homozygous cardiac calsequestrin-2-R33Q myocytes develop spontaneous Ca²⁺ release events with a broad range of intervals coupled to preceding beats, leading to the formation of early and delayed afterdepolarizations. They also display a major disruption of the Ca²⁺ release unit architecture that leads to fragmentation of spontaneous Ca²⁺ waves. We propose that these 2 substrates in R33Q myocytes synergize to provide a new arrhythmogenic mechanism for catecholaminergic polymorphic ventricular tachycardia.

  14. Molten-Phase Hydrolysis Stage Analysis and Experiments for the Calcium Bromine Thermochemical Cycle

    SciTech Connect

    Doctor, Richard D.; Panchal, C.B.; Lottes, Steven A.; Lyczkowski, Robert W.; Yang, Jianhong

    2007-07-01

    The goal of the United States Department of Energy Nuclear Hydrogen Initiative as linked with the Generation IV Nuclear Energy Systems Initiative for Gas Reactor Deployment is to develop a cost-effective, proliferation-resistant, low-greenhouse-gas emissions, and sustainable, nuclear-based energy supply system. The calcium-bromine cycle under development at Argonne National Laboratory combines both experimental and modeling studies of a novel continuous 'hybrid' cycle for hydrogen production, where 'hybrid' means that both nuclear heat and electricity are employed. Engineering the calcium-bromine cycle for continuous operation should facilitate its practical development since there will be an inherent advantage to using components and materials which will operate in a constant, non-cycling chemical and thermal environment. This paper focuses on the first and important calcium bromide hydrolysis stage to generate hydrogen bromide, which when split by electrolysis, produces hydrogen. (authors)

  15. Mutant laboratory mice with abnormalities in hair follicle morphogenesis, cycling, and/or structure: an update.

    PubMed

    Nakamura, Motonobu; Schneider, Marlon R; Schmidt-Ullrich, Ruth; Paus, Ralf

    2013-01-01

    Human hair disorders comprise a number of different types of alopecia, atrichia, hypotrichosis, distinct hair shaft disorders as well as hirsutism and hypertrichosis. Their causes vary from genodermatoses (e.g. hypotrichoses) via immunological disorders (e.g. alopecia areata, autoimmune cicatrical alopecias) to hormone-dependent abnormalities (e.g. androgenetic alopecia). A large number of spontaneous mouse mutants and genetically engineered mice develop abnormalities in hair follicle morphogenesis, cycling, and/or hair shaft formation, whose analysis has proven invaluable to define the molecular regulation of hair growth, ranging from hair follicle development, and cycling to hair shaft formation and stem cell biology. Also, the accumulating reports on hair phenotypes of mouse strains provide important pointers to better understand the molecular mechanisms underlying human hair growth disorders. Since numerous new mouse mutants with a hair phenotype have been reported since the publication of our earlier review on this matter a decade ago, we present here an updated, tabulated mini-review. The updated annotated tables list a wide selection of mouse mutants with hair growth abnormalities, classified into four categories: Mutations that affect hair follicle (1) morphogenesis, (2) cycling, (3) structure, and (4) mutations that induce extrafollicular events (for example immune system defects) resulting in secondary hair growth abnormalities. This synthesis is intended to provide a useful source of reference when studying the molecular controls of hair follicle growth and differentiation, and whenever the hair phenotypes of a newly generated mouse mutant need to be compared with existing ones. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  16. A dynamic marine calcium cycle during the past 28 million years

    USGS Publications Warehouse

    Griffith, E.M.; Paytan, A.; Caldeira, K.; Bullen, T.D.; Thomas, E.

    2008-01-01

    Multiple lines of evidence have shown that the isotopic composition and concentration of calcium in seawater have changed over the past 28 million years. A high-resolution, continuous seawater calcium isotope ratio curve from marine (pelagic) barite reveals distinct features in the evolution of the seawater calcium isotopic ratio suggesting changes in seawater calcium concentrations. The most pronounced increase in the ??44/40Ca value of seawater (of 0.3 per mil) occurred over roughly 4 million years following a period of low values around 13 million years ago. The major change in marine calcium corresponds to a climatic transition and global change in the carbon cycle and suggests a reorganization of the global biogeochemical system.

  17. Calcium signaling and cell cycle: Progression or death.

    PubMed

    Humeau, Juliette; Bravo-San Pedro, José Manuel; Vitale, Ilio; Nuñez, Lucia; Villalobos, Carlos; Kroemer, Guido; Senovilla, Laura

    2017-07-25

    Cytosolic Ca(2+) concentration levels fluctuate in an ordered manner along the cell cycle, in line with the fact that Ca(2+) is involved in the regulation of cell proliferation. Cell proliferation should be an error-free process, yet is endangered by mistakes. In fact, a complex network of proteins ensures that cell cycle does not progress until the previous phase has been successfully completed. Occasionally, errors occur during the cell cycle leading to cell cycle arrest. If the error is severe, and the cell cycle checkpoints work perfectly, this results into cellular demise by activation of apoptotic or non-apoptotic cell death programs. Cancer is characterized by deregulated proliferation and resistance against cell death. Ca(2+) is a central key to these phenomena as it modulates signaling pathways that control oncogenesis and cancer progression. Here, we discuss how Ca(2+) participates in the exogenous and endogenous signals controlling cell proliferation, as well as in the mechanisms by which cells die if irreparable cell cycle damage occurs. Moreover, we summarize how Ca(2+) homeostasis remodeling observed in cancer cells contributes to deregulated cell proliferation and resistance to cell death. Finally, we discuss the possibility to target specific components of Ca(2+) signal pathways to obtain cytostatic or cytotoxic effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Dexamethasone-induced cardiac deterioration is associated with both calcium handling abnormalities and calcineurin signaling pathway activation.

    PubMed

    de Salvi Guimarães, Fabiana; de Moraes, Wilson Max Almeida Monteiro; Bozi, Luis Henrique Marchesi; Souza, Pâmela R; Antonio, Ednei Luiz; Bocalini, Danilo Sales; Tucci, Paulo José Ferreira; Ribeiro, Daniel Araki; Brum, Patricia Chakur; Medeiros, Alessandra

    2017-01-01

    Dexamethasone is a potent and widely used anti-inflammatory and immunosuppressive drug. However, recent evidences suggest that dexamethasone cause pathologic cardiac remodeling, which later impairs cardiac function. The mechanism behind the cardiotoxic effect of dexamethasone is elusive. The present study aimed to verify if dexamethasone-induced cardiotoxicity would be associated with changes in the cardiac net balance of calcium handling protein and calcineurin signaling pathway activation. Wistar rats (~400 g) were treated with dexamethasone (35 µg/g) in drinking water for 15 days. After dexamethasone treatment, we analyzed cardiac function, cardiomyocyte diameter, cardiac fibrosis, and the expression of proteins involved in calcium handling and calcineurin signaling pathway. Dexamethasone-treated rats showed several cardiovascular abnormalities, including elevated blood pressure, diastolic dysfunction, cardiac fibrosis, and cardiomyocyte apoptosis. Regarding the expression of proteins involved in calcium handling, dexamethasone increased phosphorylation of phospholamban at threonine 17, reduced protein levels of Na(+)/Ca(2+) exchanger, and had no effect on protein expression of Serca2a. Protein levels of NFAT and GATA-4 were increased in both cytoplasmic and nuclear faction. In addition, dexamethasone increased nuclear protein levels of calcineurin. Altogether our findings suggest that dexamethasone causes pathologic cardiac remodeling and diastolic dysfunction, which is associated with impaired calcium handling and calcineurin signaling pathway activation.

  19. Calcium and cell cycle progression: possible effects of external perturbations on cell proliferation.

    PubMed Central

    Baran, I

    1996-01-01

    Exit from the phase of cellular division appears to be driven by a calcium signal that triggers a cascade of events leading to the completion of mitosis. Here we propose a model that relates the dynamics of cytosolic calcium to progression through mitosis, G1 and G2 phases of the cell cycle. To this end, the assumption has been made that the transient rise ir cytosolic calcium concentration during mitosis is induced by inositol(1,4,5)triphosphate (IP3), which in turn is released at high levels of mitosis-promoting factor (MPF). On this basis, a system of ordinary differential equations is proposed to simulate the evolution of ten cell-cycle-specific molecular species, including cyclins A and B, MPF, IP3, Ca2+, the CaMKII holoenzyme, and the ubiquitination complex. The influence on the cell proliferation capacity exerted by external perturbations, like calcium microinjections, depletion of intracellular calcium stores, electromagnetic fields, or stimulation/inhibition of different calcium currents through the plasma membrane, can be studied by appropriate modulation of the parameters involved in the signal transduction pathway. PMID:8785278

  20. Calcium cycling proteins and heart failure: mechanisms and therapeutics.

    PubMed

    Marks, Andrew R

    2013-01-01

    Ca2+-dependent signaling is highly regulated in cardiomyocytes and determines the force of cardiac muscle contraction. Ca2+ cycling refers to the release and reuptake of intracellular Ca2+ that drives muscle contraction and relaxation. In failing hearts, Ca2+ cycling is profoundly altered, resulting in impaired contractility and fatal cardiac arrhythmias. The key defects in Ca2+ cycling occur at the level of the sarcoplasmic reticulum (SR), a Ca2+ storage organelle in muscle. Defects in the regulation of Ca2+ cycling proteins including the ryanodine receptor 2, cardiac (RyR2)/Ca2+ release channel macromolecular complexes and the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a)/phospholamban complex contribute to heart failure. RyR2s are oxidized, nitrosylated, and PKA hyperphosphorylated, resulting in "leaky" channels in failing hearts. These leaky RyR2s contribute to depletion of Ca2+ from the SR, and the leaking Ca2+ depolarizes cardiomyocytes and triggers fatal arrhythmias. SERCA2a is downregulated and phospholamban is hypophosphorylated in failing hearts, resulting in impaired SR Ca2+ reuptake that conspires with leaky RyR2 to deplete SR Ca2+. Two new therapeutic strategies for heart failure (HF) are now being tested in clinical trials: (a) fixing the leak in RyR2 channels with a novel class of Ca2+-release channel stabilizers called Rycals and (b) increasing expression of SERCA2a to improve SR Ca2+ reuptake with viral-mediated gene therapy. There are many potential opportunities for additional mechanism-based therapeutics involving the machinery that regulates Ca2+ cycling in the heart.

  1. Enhanced calcium cycling and contractile function in transgenic hearts expressing constitutively active G alpha o* protein.

    PubMed

    Zhu, Ming; Gach, Agnieszka A; Liu, GongXin; Xu, Xiaomei; Lim, Chee Chew; Zhang, Julie X; Mao, Lan; Chuprun, Kurt; Koch, Walter J; Liao, Ronglih; Koren, Gideon; Blaxall, Burns C; Mende, Ulrike

    2008-03-01

    In contrast to the other heterotrimeric GTP-binding proteins (G proteins) Gs and Gi, the functional role of G o is still poorly defined. To investigate the role of G alpha o in the heart, we generated transgenic mice with cardiac-specific expression of a constitutively active form of G alpha o1* (G alpha o*), the predominant G alpha o isoform in the heart. G alpha o expression was increased 3- to 15-fold in mice from 5 independent lines, all of which had a normal life span and no gross cardiac morphological abnormalities. We demonstrate enhanced contractile function in G alpha o* transgenic mice in vivo, along with increased L-type Ca2+ channel current density, calcium transients, and cell shortening in ventricular G alpha o*-expressing myocytes compared with wild-type controls. These changes were evident at baseline and maintained after isoproterenol stimulation. Expression levels of all major Ca2+ handling proteins were largely unchanged, except for a modest reduction in Na+/Ca2+ exchanger in transgenic ventricles. In contrast, phosphorylation of the ryanodine receptor and phospholamban at known PKA sites was increased 1.6- and 1.9-fold, respectively, in G alpha o* ventricles. Density and affinity of beta-adrenoceptors, cAMP levels, and PKA activity were comparable in G alpha o* and wild-type myocytes, but protein phosphatase 1 activity was reduced upon G alpha o* expression, particularly in the vicinity of the ryanodine receptor. We conclude that G alpha o* exerts a positive effect on Ca2+ cycling and contractile function. Alterations in protein phosphatase 1 activity rather than PKA-mediated phosphorylation might be involved in hyperphosphorylation of key Ca2+ handling proteins in hearts with constitutive G alpha o activation.

  2. Role of calcium signaling in the activation of mitochondrial nitric oxide synthase and citric acid cycle.

    PubMed

    Traaseth, Nathaniel; Elfering, Sarah; Solien, Joseph; Haynes, Virginia; Giulivi, Cecilia

    2004-07-23

    An apparent discrepancy arises about the role of calcium on the rates of oxygen consumption by mitochondria: mitochondrial calcium increases the rate of oxygen consumption because of the activation of calcium-activated dehydrogenases, and by activating mitochondrial nitric oxide synthase (mtNOS), decreases the rates of oxygen consumption because nitric oxide is a competitive inhibitor of cytochrome oxidase. To this end, the rates of oxygen consumption and nitric oxide production were followed in isolated rat liver mitochondria in the presence of either L-Arg (to sustain a mtNOS activity) or N(G)-monomethyl-L-Arg (NMMA, a competitive inhibitor of mtNOS) under State 3 conditions. In the presence of NMMA, the rates of State 3 oxygen consumption exhibited a K(0.5) of 0.16 microM intramitochondrial free calcium, agreeing with those required for the activation of the Krebs cycle. By plotting the difference between the rates of oxygen consumption in State 3 with L-Arg and with NMMA at various calcium concentrations, a K(0.5) of 1.2 microM intramitochondrial free calcium was obtained, similar to the K(0.5) (0.9 microM) of the dependence of the rate of nitric oxide production on calcium concentrations. The activation of dehydrogenases, followed by the activation of mtNOS, would lead to the modulation of the Krebs cycle activity by the modulation of nitric oxide on the respiratory rates. This would ensue in changes in the NADH/NAD and ATP/ADP ratios, which would influence the rate of the cycle and the oxygen diffusion.

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

    PubMed

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

    2012-12-01

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

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

    PubMed Central

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

    2012-01-01

    The risk of sudden cardiac death is increased following myocardial infarction. Exercise training reduces arrhythmia susceptibility, but the mechanism is unknown. We used a canine model of sudden cardiac death (healed infarction, with ventricular tachyarrhythmias induced by an exercise plus ischemia test, VF+); we previously reported that endurance exercise training was antiarrhythmic in this model (Billman GE. Am J Physiol Heart Circ Physiol 297: H1171–H1193, 2009). A total of 41 VF+ animals were studied, after random assignment to 10 wk of endurance exercise training (EET; n = 21) or a matched sedentary period (n = 20). Following (>1 wk) the final attempted arrhythmia induction, isolated myocytes were used to test the hypotheses that the endurance exercise-induced antiarrhythmic effects resulted from normalization of cellular electrophysiology and/or normalization of calcium handling. EET prevented VF and shortened in vivo repolarization (P < 0.05). EET normalized action potential duration and variability compared with the sedentary group. EET resulted in a further decrement in transient outward current compared with the sedentary VF+ group (P < 0.05). Sedentary VF+ dogs had a significant reduction in repolarizing K+ current, which was restored by exercise training (P < 0.05). Compared with controls, myocytes from the sedentary VF+ group displayed calcium alternans, increased calcium spark frequency, and increased phosphorylation of S2814 on ryanodine receptor 2. These abnormalities in intracellular calcium handling were attenuated by exercise training (P < 0.05). Exercise training prevented ischemically induced VF, in association with a combination of beneficial effects on cellular electrophysiology and calcium handling. PMID:23042911

  5. Calcium

    MedlinePlus

    ... You'll also find calcium in broccoli and dark green, leafy vegetables (especially collard and turnip greens, ... can enjoy good sources of calcium such as dark green, leafy vegetables, broccoli, chickpeas, and calcium-fortified ...

  6. Blood metabolomics analysis identifies abnormalities in the citric acid cycle, urea cycle, and amino acid metabolism in bipolar disorder.

    PubMed

    Yoshimi, Noriko; Futamura, Takashi; Kakumoto, Keiji; Salehi, Alireza M; Sellgren, Carl M; Holmén-Larsson, Jessica; Jakobsson, Joel; Pålsson, Erik; Landén, Mikael; Hashimoto, Kenji

    2016-06-01

    Bipolar disorder (BD) is a severe and debilitating psychiatric disorder. However, the precise biological basis remains unknown, hampering the search for novel biomarkers. We performed a metabolomics analysis to discover novel peripheral biomarkers for BD. We quantified serum levels of 116 metabolites in mood-stabilized male BD patients (n = 54) and age-matched male healthy controls (n = 39). After multivariate logistic regression, serum levels of pyruvate, N-acetylglutamic acid, α-ketoglutarate, and arginine were significantly higher in BD patients than in healthy controls. Conversely, serum levels of β-alanine, and serine were significantly lower in BD patients than in healthy controls. Chronic (4-weeks) administration of lithium or valproic acid to adult male rats did not alter serum levels of pyruvate, N-acetylglutamic acid, β-alanine, serine, or arginine, but lithium administration significantly increased serum levels of α-ketoglutarate. The metabolomics analysis demonstrated altered serum levels of pyruvate, N-acetylglutamic acid, β-alanine, serine, and arginine in BD patients. The present findings suggest that abnormalities in the citric acid cycle, urea cycle, and amino acid metabolism play a role in the pathogenesis of BD.

  7. Abnormalities in the tricarboxylic Acid cycle in Huntington disease and in a Huntington disease mouse model.

    PubMed

    Naseri, Nima N; Xu, Hui; Bonica, Joseph; Vonsattel, Jean Paul G; Cortes, Etty P; Park, Larry C; Arjomand, Jamshid; Gibson, Gary E

    2015-06-01

    Glucose metabolism is reduced in the brains of patients with Huntington disease (HD). The mechanisms underlying this deficit, its link to the pathology of the disease, and the vulnerability of the striatum in HD remain unknown. Abnormalities in some of the key mitochondrial enzymes involved in glucose metabolism, including the pyruvate dehydrogenase complex (PDHC) and the tricarboxylic acid (TCA) cycle, may contribute to these deficits. Here, activities for these enzymes and select protein levels were measured in human postmortem cortex and in striatum and cortex of an HD mouse model (Q175); mRNA levels encoding for these enzymes were also measured in the Q175 mouse cortex. The activities of PDHC and nearly all of the TCA cycle enzymes were dramatically lower (-50% to 90%) in humans than in mice. The activity of succinate dehydrogenase increased with HD in human (35%) and mouse (23%) cortex. No other changes were detected in the human HD cortex or mouse striatum. In Q175 cortex, there were increased activities of PDHC (+12%) and aconitase (+32%). Increased mRNA levels for succinyl thiokinase (+88%) and isocitrate dehydrogenase (+64%) suggested an upregulation of the TCA cycle. These patterns of change differ from those reported in other diseases, which may offer unique metabolic therapeutic opportunities for HD patients.

  8. Abnormalities in the Tricarboxylic Acid Cycle in Huntington Disease and in a Huntington Disease Mouse Model

    PubMed Central

    Naseri, Nima N.; Xu, Hui; Bonica, Joseph; Vonsattel, Jean Paul G.; Cortes, Etty P.; Park, Larry C.; Arjomand, Jamshid; Gibson, Gary E.

    2015-01-01

    Glucose metabolism is reduced in the brains of patients with Huntington disease (HD). The mechanisms underlying this deficit, its link to the pathology of the disease and the vulnerability of the striatum in HD remain unknown. Abnormalities in some of the key mitochondrial enzymes involved in glucose metabolism, including the pyruvate dehydrogenase complex (PDHC) and the tricarboxylic acid (TCA) cycle, may contribute to these deficits. Here, activities for these enzymes and select protein levels were measured in human postmortem cortex and in striatum and cortex of an HD mouse model (Q175); mRNA levels encoding for these enzymes were also measured in the Q175 mouse cortex. The activities of PDHC and nearly all of the TCA cycle enzymes were dramatically lower (−50%–90%) in humans than in mice. The activity of succinate dehydrogenase increased with HD in human (35%) and mouse (23%) cortex. No other changes were detected in the HD cortex or mouse striatum. In Q175 cortex, there were increased activities of PDHC (+12%) and aconitase (+32%). Increased mRNA levels for succinyl thiokinase (+88%) and isocitrate dehydrogenase (+64%), suggested an upregulation of the TCA cycle. These patterns of change differ from those reported in other diseases, which may offer unique metabolic therapeutic opportunities for HD patients. PMID:25978848

  9. [Prevalence of anemia, calcium-phosphorus abnormalities and metabolic acidosis in different stages of chronic renal failure].

    PubMed

    Zarzecki, Miłosz; Chudek, Jerzy; Kukla, Małgorzata; Kopeć, Paulina; Mamcarz, Ewelina; Wnuk, Zuzanna; Kokot, Franciszek; Wiecek, Andrzej

    2004-10-01

    Chronic kidney disease (CKD) is associated with the reduction of haemoglobin concentration and a variety of biochemical abnormalities including changes in serum concentration of sodium, potassium, calcium, phosphate, bicarbonate, and hydrogen ions. However, data concerning epidemiology of these abnormalities are rare and incomplete, especially among subjects with mild to moderate CKD. Patients with a serum creatinine concentration > 110 micromol/l hospitalized in the Department of Nephrology, Endocrinology and Metabolic Diseases Medical University of Silesia from 1998 to 2002 were analyzed. Patients with acute renal failure or chronic renal failure treated with renal replacement therapy were excluded from this study. A total of 653 patients (262F and 391M) were divided into 9 subgroups differing from each other by progressive decline of glomerular filtration rate (GFR). A statistically significant decrease in haemoglobin concentration and increase in the prevalence of anaemia were found in patients with GFR < 50 ml/min. In a large number of patients with a GFR < 80 but > 50 ml/min, Hb concentration <11 g/dl was observed. Mean MCV, MCH and serum iron concentration were similar in all studied subgroups. A progressive increase in serum phosphorus concentration and decrease of calcaemia was found in patients with GFR < 30 ml/min. The elevated Ca x P product (> 4.44 mmol2/12) was noticed almost exclusively in patients with GFR< 30 ml/min. A decompensated metabolic acidosis was observed in 29.8% of patients with GFR <30 ml/min. Anaemia is an early symptom of chronic kidney disease preceding disturbances of calcium, phosphate and hydrogen ions metabolism. These abnormalities seem to be of therapeutic relevance.

  10. Biogeochemistry cycling of calcium and magnesium by Ceanothus and chamise

    SciTech Connect

    Quideau, S.A.; Graham, R.C.; Chadwick, O.A.; Wood, H.B.

    1999-12-01

    Vegetation has long been recognized as a fundamental factor in soil formation, but vegetation and soils commonly covary in response to other environmental factors, confounding the specific effects of vegetation on soil properties. The lysimeter installation at the San Dimas Experimental Forest in southern California offers a rarely found opportunity for quantifying cation-cycling processes in a setting where all factors except vegetation are kept constant. The lysimeters were filled in 1937 with homogenized, fine sandy loam and planted in 1946 with chamise (Adenostoma fasciculatum Hook, and Arn.) and ceanothus (Ceanothus crassifolius Torr.). Comparison of the chamise and ceanothus lysimeters was best achieved by using the Ca/Mg ration of the different cation pools and fluxes as an index. In 1987, the ceanothus exchangeable soil pool contained proportionally more Ca than Mg compared with chamise; that is, the Ca/Mg ratio in the ceanothus exchangeable soil pool was higher than that in chamise. Strong evidence supports vegetation influence on intra-system fluxes (weathering and biocycling) as the basis for these differences. First, more Ca than Mg was released by weathering under ceanothus than under chamise. Second, the ceanothus aboveground biomass exhibited a higher Ca/Mg ration that the chamise. Third, differences between vegetation types widened with time since construction of the lysimeter installation in both the aboveground biomass and exchangeable soil pools. Differences in cation storage measured for the lysimeter chamise and ceanothus stands appear representative of natural chaparral communities throughout California, and may result in distinct Ca and Mg biogeochemical processes in associated ecosystems.

  11. Moderate ovarian stimulation does not increase the incidence of human embryo chromosomal abnormalities in in vitro fertilization cycles.

    PubMed

    Labarta, Elena; Bosch, Ernesto; Alamá, Pilar; Rubio, Carmen; Rodrigo, Lorena; Pellicer, Antonio

    2012-10-01

    A high chromosomal abnormalities rate has been observed in human embryos derived from in vitro fertilization (IVF) treatments. The real incidence in natural cycles has been poorly studied, so whether this frequency may be induced by external factors, such as use of gonadotropins for ovarian stimulation, remains unknown. We conducted a prospective cohort study in a University-affiliated private infertility clinic with a comparison between unstimulated and stimulated ovarian cycles in the same women. Preimplantation genetic screening by fluorescence in situ hybridization was performed in all viable d 3 embryos. The primary objective was to compare the incidence of embryo chromosomal abnormalities in an unstimulated cycle and in an ulterior moderate ovarian stimulated cycle. Secondary outcome measures were embryo quality, blastocyst rate of biopsied embryos, number of normal blastocysts per donor, type of chromosomal abnormalities, and clinical outcome. One hundred eighty-five oocyte donors were initially recruited for the unstimulated cycle, and preimplantation genetic screening could be performed in 51 of them, showing 35.3% of embryo chromosomal abnormalities. Forty-six of them later completed a stimulated cycle. The sperm donor sample was the same for both cycles. The proportion of embryos displaying abnormalities in the unstimulated cycle was 34.8% (16 of 46), whereas it was 40.6% (123 of 303) in the stimulated cycle with risk difference=5.8 [95% confidence interval (CI)=-20.6-9.0], and relative risk=1.17 (95% CI=0.77-1.77) (P=0.45). When an intrasubject comparison was made, the abnormalities rate was 34.8% (95% CI=20.5-49.1) in the unstimulated cycle and 38.2% (95% CI=30.5-45.8) in the stimulated cycle [risk difference=3.4 (95% CI=-17.9-11.2); P=0.64]. No differences were observed for embryo quality and type of chromosomal abnormalities. Moderate ovarian stimulation in young normo-ovulatory women does not significantly increase the embryo aneuploidies rate in in

  12. Moderate Ovarian Stimulation Does Not Increase the Incidence of Human Embryo Chromosomal Abnormalities in in Vitro Fertilization Cycles

    PubMed Central

    Bosch, Ernesto; Alamá, Pilar; Rubio, Carmen; Rodrigo, Lorena; Pellicer, Antonio

    2012-01-01

    Context: A high chromosomal abnormalities rate has been observed in human embryos derived from in vitro fertilization (IVF) treatments. The real incidence in natural cycles has been poorly studied, so whether this frequency may be induced by external factors, such as use of gonadotropins for ovarian stimulation, remains unknown. Design: We conducted a prospective cohort study in a University-affiliated private infertility clinic with a comparison between unstimulated and stimulated ovarian cycles in the same women. Preimplantation genetic screening by fluorescence in situ hybridization was performed in all viable d 3 embryos. Objective: The primary objective was to compare the incidence of embryo chromosomal abnormalities in an unstimulated cycle and in an ulterior moderate ovarian stimulated cycle. Secondary outcome measures were embryo quality, blastocyst rate of biopsied embryos, number of normal blastocysts per donor, type of chromosomal abnormalities, and clinical outcome. Results: One hundred eighty-five oocyte donors were initially recruited for the unstimulated cycle, and preimplantation genetic screening could be performed in 51 of them, showing 35.3% of embryo chromosomal abnormalities. Forty-six of them later completed a stimulated cycle. The sperm donor sample was the same for both cycles. The proportion of embryos displaying abnormalities in the unstimulated cycle was 34.8% (16 of 46), whereas it was 40.6% (123 of 303) in the stimulated cycle with risk difference = 5.8 [95% confidence interval (CI) = −20.6–9.0], and relative risk = 1.17 (95% CI = 0.77–1.77) (P = 0.45). When an intrasubject comparison was made, the abnormalities rate was 34.8% (95% CI = 20.5–49.1) in the unstimulated cycle and 38.2% (95% CI = 30.5–45.8) in the stimulated cycle [risk difference = 3.4 (95% CI = −17.9–11.2); P = 0.64]. No differences were observed for embryo quality and type of chromosomal abnormalities. Conclusions: Moderate ovarian stimulation in young

  13. Clinical outcome of treatment cycles using preimplantation genetic diagnosis for structural chromosomal abnormalities.

    PubMed

    Fridström, M; Ahrlund-Richter, L; Iwarsson, E; Malmgren, H; Inzunza, J; Rosenlund, B; Sjöblom, P; Nordenskjöld, M; Blennow, E; Hovatta, O

    2001-09-01

    To explore oocyte recovery, embryo quality, the number of transferable embryos and pregnancy rate after preimplantation genetic diagnosis (PGD) in patients with structural chromosomal aberrations. PGD was performed in seven couples with Robertsonian translocations (Rob), eight couples with reciprocal translocations (Rec), two couples with inversions and one couple with a deletion. A total of 43 treatment cycles were carried out. A total of 14.2 oocytes per cycle were retrieved. Fertilisation and cleavage rates were 63% and 58%, respectively. Of the biopsied embryos 20% were transferable. Comparison of the Rob and Rec group revealed no significant differences in number of oocytes, fertilisation or cleavage rates. The number of transferable embryos after biopsy was significantly higher in the Rob group than in the Rec group. When embryo transfer (ET) was performed the pregnancy rate did not differ between the Rob and the Rec groups. Twenty-eight embryo transfers (one or two embryos) were carried out leading to eight clinical pregnancies (29% per ET): two twins, four singletons, one miscarriage and one ectopic pregnancy. All the children are carriers of balanced chromosomal aberrations. An acceptable pregnancy rate can be achieved among couples with structural chromosomal abnormalities. Copyright 2001 John Wiley & Sons, Ltd.

  14. Abnormal mitosis triggers p53-dependent cell cycle arrest in human tetraploid cells.

    PubMed

    Kuffer, Christian; Kuznetsova, Anastasia Yurievna; Storchová, Zuzana

    2013-08-01

    Erroneously arising tetraploid mammalian cells are chromosomally instable and may facilitate cell transformation. An increasing body of evidence shows that the propagation of mammalian tetraploid cells is limited by a p53-dependent arrest. The trigger of this arrest has not been identified so far. Here we show by live cell imaging of tetraploid cells generated by an induced cytokinesis failure that most tetraploids arrest and die in a p53-dependent manner after the first tetraploid mitosis. Furthermore, we found that the main trigger is a mitotic defect, in particular, chromosome missegregation during bipolar mitosis or spindle multipolarity. Both a transient multipolar spindle followed by efficient clustering in anaphase as well as a multipolar spindle followed by multipolar mitosis inhibited subsequent proliferation to a similar degree. We found that the tetraploid cells did not accumulate double-strand breaks that could cause the cell cycle arrest after tetraploid mitosis. In contrast, tetraploid cells showed increased levels of oxidative DNA damage coinciding with the p53 activation. To further elucidate the pathways involved in the proliferation control of tetraploid cells, we knocked down specific kinases that had been previously linked to the cell cycle arrest and p53 phosphorylation. Our results suggest that the checkpoint kinase ATM phosphorylates p53 in tetraploid cells after abnormal mitosis and thus contributes to proliferation control of human aberrantly arising tetraploids.

  15. Calcium

    MedlinePlus

    ... in luck if you like sardines and canned salmon with bones. Almond milk. previous continue Working Calcium ... drinks, and cereals. Other Considerations for Building Bones Vitamin D is essential for calcium absorption, so it's ...

  16. Calcium

    MedlinePlus

    ... such as canned sardines and salmon Calcium-enriched foods such as breakfast cereals, fruit juices, soy and rice drinks, and tofu. Check the product labels. The exact amount of calcium you need depends on your age and other factors. Growing children and teenagers need more calcium than ...

  17. Crude oil exposures reveal roles for intracellular calcium cycling in haddock craniofacial and cardiac development

    PubMed Central

    Sørhus, Elin; Incardona, John P.; Karlsen, Ørjan; Linbo, Tiffany; Sørensen, Lisbet; Nordtug, Trond; van der Meeren, Terje; Thorsen, Anders; Thorbjørnsen, Maja; Jentoft, Sissel; Edvardsen, Rolf B.; Meier, Sonnich

    2016-01-01

    Recent studies have shown that crude oil exposure affects cardiac development in fish by disrupting excitation-contraction (EC) coupling. We previously found that eggs of Atlantic haddock (Melanogrammus aeglefinus) bind dispersed oil droplets, potentially leading to more profound toxic effects from uptake of polycyclic aromatic hydrocarbons (PAHs). Using lower concentrations of dispersed crude oil (0.7–7 μg/L ∑PAH), here we exposed a broader range of developmental stages over both short and prolonged durations. We quantified effects on cardiac function and morphogenesis, characterized novel craniofacial defects, and examined the expression of genes encoding potential targets underlying cardiac and craniofacial defects. Because of oil droplet binding, a 24-hr exposure was sufficient to create severe cardiac and craniofacial abnormalities. The specific nature of the craniofacial abnormalities suggests that crude oil may target common craniofacial and cardiac precursor cells either directly or indirectly by affecting ion channels and intracellular calcium in particular. Furthermore, down-regulation of genes encoding specific components of the EC coupling machinery suggests that crude oil disrupts excitation-transcription coupling or normal feedback regulation of ion channels blocked by PAHs. These data support a unifying hypothesis whereby depletion of intracellular calcium pools by crude oil-derived PAHs disrupts several pathways critical for organogenesis in fish. PMID:27506155

  18. Crude oil exposures reveal roles for intracellular calcium cycling in haddock craniofacial and cardiac development.

    PubMed

    Sørhus, Elin; Incardona, John P; Karlsen, Ørjan; Linbo, Tiffany; Sørensen, Lisbet; Nordtug, Trond; van der Meeren, Terje; Thorsen, Anders; Thorbjørnsen, Maja; Jentoft, Sissel; Edvardsen, Rolf B; Meier, Sonnich

    2016-08-10

    Recent studies have shown that crude oil exposure affects cardiac development in fish by disrupting excitation-contraction (EC) coupling. We previously found that eggs of Atlantic haddock (Melanogrammus aeglefinus) bind dispersed oil droplets, potentially leading to more profound toxic effects from uptake of polycyclic aromatic hydrocarbons (PAHs). Using lower concentrations of dispersed crude oil (0.7-7 μg/L ∑PAH), here we exposed a broader range of developmental stages over both short and prolonged durations. We quantified effects on cardiac function and morphogenesis, characterized novel craniofacial defects, and examined the expression of genes encoding potential targets underlying cardiac and craniofacial defects. Because of oil droplet binding, a 24-hr exposure was sufficient to create severe cardiac and craniofacial abnormalities. The specific nature of the craniofacial abnormalities suggests that crude oil may target common craniofacial and cardiac precursor cells either directly or indirectly by affecting ion channels and intracellular calcium in particular. Furthermore, down-regulation of genes encoding specific components of the EC coupling machinery suggests that crude oil disrupts excitation-transcription coupling or normal feedback regulation of ion channels blocked by PAHs. These data support a unifying hypothesis whereby depletion of intracellular calcium pools by crude oil-derived PAHs disrupts several pathways critical for organogenesis in fish.

  19. Crude oil exposures reveal roles for intracellular calcium cycling in haddock craniofacial and cardiac development

    NASA Astrophysics Data System (ADS)

    Sørhus, Elin; Incardona, John P.; Karlsen, Ørjan; Linbo, Tiffany; Sørensen, Lisbet; Nordtug, Trond; van der Meeren, Terje; Thorsen, Anders; Thorbjørnsen, Maja; Jentoft, Sissel; Edvardsen, Rolf B.; Meier, Sonnich

    2016-08-01

    Recent studies have shown that crude oil exposure affects cardiac development in fish by disrupting excitation-contraction (EC) coupling. We previously found that eggs of Atlantic haddock (Melanogrammus aeglefinus) bind dispersed oil droplets, potentially leading to more profound toxic effects from uptake of polycyclic aromatic hydrocarbons (PAHs). Using lower concentrations of dispersed crude oil (0.7–7 μg/L ∑PAH), here we exposed a broader range of developmental stages over both short and prolonged durations. We quantified effects on cardiac function and morphogenesis, characterized novel craniofacial defects, and examined the expression of genes encoding potential targets underlying cardiac and craniofacial defects. Because of oil droplet binding, a 24-hr exposure was sufficient to create severe cardiac and craniofacial abnormalities. The specific nature of the craniofacial abnormalities suggests that crude oil may target common craniofacial and cardiac precursor cells either directly or indirectly by affecting ion channels and intracellular calcium in particular. Furthermore, down-regulation of genes encoding specific components of the EC coupling machinery suggests that crude oil disrupts excitation-transcription coupling or normal feedback regulation of ion channels blocked by PAHs. These data support a unifying hypothesis whereby depletion of intracellular calcium pools by crude oil-derived PAHs disrupts several pathways critical for organogenesis in fish.

  20. Abnormal calcium homeostasis in heart failure with preserved ejection fraction is related to both reduced contractile function and incomplete relaxation: an electromechanically detailed biophysical modeling study

    PubMed Central

    Adeniran, Ismail; MacIver, David H.; Hancox, Jules C.; Zhang, Henggui

    2015-01-01

    Heart failure with preserved ejection fraction (HFpEF) accounts for about 50% of heart failure cases. It has features of incomplete relaxation and increased stiffness of the left ventricle. Studies from clinical electrophysiology and animal experiments have found that HFpEF is associated with impaired calcium homeostasis, ion channel remodeling and concentric left ventricle hypertrophy (LVH). However, it is still unclear how the abnormal calcium homeostasis, ion channel and structural remodeling affect the electro-mechanical dynamics of the ventricles. In this study we have developed multiscale models of the human left ventricle from single cells to the 3D organ, which take into consideration HFpEF-induced changes in calcium handling, ion channel remodeling and concentric LVH. Our simulation results suggest that at the cellular level, HFpEF reduces the systolic calcium level resulting in a reduced systolic contractile force, but elevates the diastolic calcium level resulting in an abnormal residual diastolic force. In our simulations, these abnormal electro-mechanical features of the ventricular cells became more pronounced with the increase of the heart rate. However, at the 3D organ level, the ejection fraction of the left ventricle was maintained due to the concentric LVH. The simulation results of this study mirror clinically observed features of HFpEF and provide new insights toward the understanding of the cellular bases of impaired cardiac electromechanical functions in heart failure. PMID:25852567

  1. Calcium-dependent deceleration of the cell cycle in muscle cells by simulated microgravity.

    PubMed

    Benavides Damm, Tatiana; Richard, Stéphane; Tanner, Samuel; Wyss, Fabienne; Egli, Marcel; Franco-Obregón, Alfredo

    2013-05-01

    Of all our mechanosensitive tissues, skeletal muscle is the most developmentally responsive to physical activity. Conversely, restricted mobility due to injury or disease results in muscle atrophy. Gravitational force is another form of mechanical input with profound developmental consequences. The mechanical unloading resulting from the reduced gravitational force experienced during spaceflight results in oxidative muscle loss. We examined the early stages of myogenesis under conditions of simulated microgravity (SM). C2C12 mouse myoblasts in SM proliferated more slowly (2.23× less) as a result of their being retained longer within the G2/M phase of the cell cycle (2.10× more) relative to control myoblasts at terrestrial gravity. Blocking calcium entry via TRP channels with SKF-96365 (10-20 μM) accumulated myoblasts within the G2/M phase of the cell cycle and retarded their proliferation. On the genetic level, SM resulted in the reduced expression of TRPC1 and IGF-1 isoforms, transcriptional events regulated by calcium downstream of mechanical input. A decrease in TRPC1-mediated calcium entry thus appears to be a pivotal event in the muscle atrophy brought on by gravitational mechanical unloading. Hence, relieving the constant force of gravity on cells might prove one valid experimental approach to expose the underlying mechanisms modulating mechanically regulated developmental programs.

  2. Abnormal fb Es enhancements in equatorial Es layers during magnetic storms of solar cycle 23

    NASA Astrophysics Data System (ADS)

    Resende, L. C. A.; Denardini, C. M.; Batista, I. S.

    2013-09-01

    We have analyzed the behavior of blanketing frequency of the Es layer (fb Es) occurring at an equatorial station covering the days before, during and subsequent to 24 intense and very intense magnetic storms (Dst≤-100 nT) that occurred during the solar cycle 23. The fb Es was measured by digital ionosonde over São Luís, Brazil (2.33° S, 44.2° W, dip: -4.5°). Our analysis shows that there are significant changes in the fb Es, mainly during the recovery phase of magnetic storms, characterized by occurrence of peaks that exceed the ambient background values. Also, these peaks are associated to other types of sporadic E layer than the Esq (a non-blanketing layer detected due the plasma irregularities in the equatorial electrojet), which in turn means competing mechanisms. The results are discussed in terms of the statistics of the abnormal enhancement taking into account the phase of the magnetic storm.

  3. Junctophilin-2 Expression Silencing Causes Cardiocyte Hypertrophy and Abnormal Intracellular Calcium-Handling

    PubMed Central

    Landstrom, Andrew P.; Kellen, Cherisse A.; Dixit, Sayali S.; van Oort, Ralph J.; Garbino, Alejandro; Weisleder, Noah; Ma, Jianjie; Wehrens, Xander H.T.; Ackerman, Michael J.

    2011-01-01

    Background Junctophilin-2 (JPH2), a protein expressed in the junctional membrane complex, is necessary for proper intracellular calcium (Ca2+) signaling in cardiac myocytes. Down-regulation of JPH2 expression in a model of cardiac hypertrophy was recently associated with defective coupling between plasmalemmal L-type Ca2+ channels and sarcoplasmic reticular ryanodine receptors. However, it remains unclear whether JPH2 expression is altered in patients with hypertrophic cardiomyopathy (HCM). In addition, the effects of down-regulation of JPH2 expression on intracellular Ca2+-handling are presently poorly understood. We sought to determine whether loss of JPH2 expression is noted among patients with HCM and whether expression silencing might perturb Ca2+-handling in a pro-hypertrophic manner. Methods and Results JPH2 expression was reduced in flash frozen human cardiac tissue procured from patients with HCM compared to ostensibly healthy traumatic death victims. Partial silencing of JPH2 expression in HL-1 cells by a small interfering RNA probe targeted to murine JPH2 mRNA (shJPH2) resulted in myocyte hypertrophy and increased expression of known markers of cardiac hypertrophy. While expression levels of major Ca2+-handling proteins were unchanged, shJPH2 cells demonstrated depressed maximal Ca2+ transient amplitudes that were insensitive to LTCC activation with JPH2 knock-down. Further, reduced caffeine-triggered SR store Ca2+ levels were observed with potentially increased total Ca2+ stores. Spontaneous Ca2+ oscillations were elicited at a higher extracellular [Ca2+] and with decreased frequency in JPH2 knock-down cells. Conclusions Our results show that JPH2 levels are reduced in patients with HCM. Reduced JPH2 expression results in reduced excitation-contraction coupling gain as well as altered Ca2+ homeostasis which may be associated with pro-hypertrophic remodeling. PMID:21216834

  4. Magnesium hydrogen carbonate natural mineral water enriched with K(+)-citrate and vitamin B6 improves urinary abnormalities in patients with calcium oxalate nephrolithiasis.

    PubMed

    Bren, A; Kmetec, A; Kveder, R; Kaplan-Pavlovcic, S

    1998-01-01

    The influence of drinking magnesium hydrogen carbonate natural mineral water enriched with potassium citrate on urinary metabolic abnormalities was prospectively studied in 27 patients with recurrent calcium oxalate nephrolithiasis. The mean 24-hour urinary pH shifted from 6.34 to 6.93 (p < 0.01), the mean urinary magnesium/urinary creatinine ratio rose from 0.47 to 0.67 (p < 0.01), the mean urinary citrate/urinary creatinine ratio increased from 0.26 to 0.35 (p NS), and the mean 24-hour urinary calcium decreased from 7.98 to 6.05 mmol (p < 0.05). The effects of magnesium hydrogen carbonate natural mineral water enriched with potassium citrate were found to be favorable on urinary calcium, urinary magnesium/urinary creatinine ratio and urinary pH in patients with calcium oxalate nephrolithiasis.

  5. Using Calcium Isotopic Composition of Calcium Carbonate Veins to Assess the Roles of Vein Formation and Seafloor Alteration in Regulation of the Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Chen, F.; Coggon, R. M.; Teagle, D. A. H.; Turchyn, A. V.

    2016-12-01

    Calcium carbonate vein formation in the oceanic crust has been proposed as a climate-sensitive feedback mechanism that regulates the carbon cycle on million-year timescales. The suggestion has been that higher pCO2 levels may drive changes in ocean temperature and pH that increase seafloor alteration, releasing more calcium from oceanic basalt. This results in more removal of carbon from Earth's surface through calcium carbonate formation, which includes calcium carbonate vein formation in oceanic crust. The importance of this feedback mechanism remains enigmatic. Measurements of the δ44Ca of calcium carbonate veins in the oceanic crust may constrain the sources of calcium and timing of vein formation. Seawater and basalt are the only sources present shortly after crustal formation, whereas other sources, such as anhydrite dissolution and sedimentary carbonates become available when the crust ages, at which point carbonate veins may form far from the ridge axis. We report the calcium isotopic composition of 65 calcium carbonate veins, ranging from 108 to 1.2 million years old, in hydrothermally altered basalt from the Mid-Atlantic and Juan de Fuca ridges. We also present 43 δ44Ca measurements of 5.9 million year old basalts and dikes from the Costa Rica Rift that have undergone hydrothermal alteration over a range of conditions in upper crust. The δ44Ca of the calcium carbonate veins ranges from -1.59 to 1.01‰ (versus Bulk Silicate Earth), whereas the δ44Ca of altered basalts ranges from -0.18 to 0.28‰. Depth and temperature of formation seem to be major influences on calcium carbonate vein δ44Ca, with veins formed at cool, shallower depths having higher δ44Ca, closer to seawater. In contrast, we note no temporal variation in δ44Ca of calcium carbonate veins when comparing samples from older and younger crust. The majority of veins (54 out of 65) have δ44Ca between that of seawater and basalt, which implies that they may have formed quite soon after

  6. Cooperative Effects of Rigor and Cycling Cross-Bridges on Calcium Binding to Troponin C

    PubMed Central

    Cantino, Marie E.; Quintanilla, Abraham

    2007-01-01

    The effects of rigor and cycling cross-bridges on distributions of calcium (Ca) bound within sarcomeres of rabbit psoas muscle fibers were compared using electron probe x-ray microanalysis. Calcium in the overlap region of rigor fibers, after correction for that bound to thick filaments, was significantly higher than in the I-band at all pCa levels tested between 6.9 and 4.8, but the difference was greatest at pCa 6.9. With addition of MgATP, differences were significant at high levels of activation (pCa 5.6 and 4.9); near and below the threshold for activation, Ca was the same in I-band and overlap regions. Comparison of Ca and mass profiles at the A-I junction showed elevation of Ca extending 55–110 nm (up to three regulatory units) into the I-band. Extraction of TnC-reduced I-band and overlap Ca in rigor fibers at pCa 5.6 to the same levels found in unextracted fibers at pCa 8.9, suggesting that variations reported here reflect changes in Ca bound to troponin C (TnC). Taken together, these observations provide evidence for near-neighbor cooperative effects of both rigor and cycling cross-bridges on Ca2+ binding to TnC. PMID:17056730

  7. Calcium Signaling During Meiotic Cell Cycle Regulation and Apoptosis in Mammalian Oocytes.

    PubMed

    Tiwari, Meenakshi; Prasad, Shilpa; Shrivastav, Tulsidas G; Chaube, Shail K

    2017-05-01

    Calcium (Ca(++) ) is one of the major signal molecules that regulate various aspects of cell functions including cell cycle progression, arrest, and apoptosis in wide variety of cells. This review summarizes current knowledge on the differential roles of Ca(++) in meiotic cell cycle resumption, arrest, and apoptosis in mammalian oocytes. Release of Ca(++) from internal stores and/or Ca(++) influx from extracellular medium causes moderate increase of intracellular Ca(++) ([Ca(++) ]i) level and reactive oxygen species (ROS). Increase of Ca(++) as well as ROS levels under physiological range trigger maturation promoting factor (MPF) destabilization, thereby meiotic resumption from diplotene as well as metaphase-II (M-II) arrest in oocytes. A sustained increase of [Ca(++) ]i level beyond physiological range induces generation of ROS sufficient enough to cause oxidative stress (OS) in aging oocytes. The increased [Ca(++) ]i triggers Fas ligand-mediated oocyte apoptosis. Further, OS triggers mitochondria-mediated oocyte apoptosis in several mammalian species. Thus, Ca(++) exerts differential roles on oocyte physiology depending upon its intracellular concentration. A moderate increase of [Ca(++) ]i as well as ROS mediate spontaneous resumption of meiosis from diplotene as well as M-II arrest, while their high levels cause meiotic cell cycle arrest and apoptosis by operating both mitochondria- as well as Fas ligand-mediated apoptotic pathways. Indeed, Ca(++) regulates cellular physiology by modulating meiotic cell cycle and apoptosis in mammalian oocytes. J. Cell. Physiol. 232: 976-981, 2017. © 2016 Wiley Periodicals, Inc.

  8. Abnormalities in intracellular calcium regulation and contractile function in myocardium from dogs with pacing-induced heart failure

    NASA Technical Reports Server (NTRS)

    Perreault, C. L.; Shannon, R. P.; Komamura, K.; Vatner, S. F.; Morgan, J. P.

    1992-01-01

    24 d of rapid ventricular pacing induced dilated cardiomyopathy with both systolic and diastolic dysfunction in conscious, chronically instrumented dogs. We studied mechanical properties and intracellular calcium (Ca2+i) transients of trabeculae carneae isolated from 15 control dogs (n = 32) and 11 dogs with pacing-induced cardiac failure (n = 26). Muscles were stretched to maximum length at 30 degrees C and stimulated at 0.33 Hz; a subset (n = 17 control, n = 17 myopathic) was loaded with the [Ca2+]i indicator aequorin. Peak tension was depressed in the myopathic muscles, even in the presence of maximally effective (i.e., 16 mM) [Ca2+] in the perfusate. However, peak [Ca2+]i was similar (0.80 +/- 0.13 vs. 0.71 +/- 0.05 microM; [Ca2+]o = 2.5 mM), suggesting that a decrease in Cai2+ availability was not responsible for the decreased contractility. The time for decline from the peak of the Cai2+ transient was prolonged in the myopathic group, which correlated with prolongation of isometric contraction and relaxation. However, similar end-diastolic [Ca2+]i was achieved in both groups (0.29 +/- 0.05 vs. 0.31 +/- 0.02 microM), indicating that Cai2+ homeostasis can be maintained in myopathic hearts. The inotropic response of the myopathic muscles to milrinone was depressed compared with the controls. However, when cAMP production was stimulated by pretreatment with forskolin, the response of the myopathic muscles to milrinone was improved. Our findings provide direct evidence that abnormal [Ca2+]i handling is an important cause of contractile dysfunction in dogs with pacing-induced heart failure and suggest that deficient production of cAMP may be an important cause of these changes in excitation-contraction coupling.

  9. Abnormalities in intracellular calcium regulation and contractile function in myocardium from dogs with pacing-induced heart failure

    NASA Technical Reports Server (NTRS)

    Perreault, C. L.; Shannon, R. P.; Komamura, K.; Vatner, S. F.; Morgan, J. P.

    1992-01-01

    24 d of rapid ventricular pacing induced dilated cardiomyopathy with both systolic and diastolic dysfunction in conscious, chronically instrumented dogs. We studied mechanical properties and intracellular calcium (Ca2+i) transients of trabeculae carneae isolated from 15 control dogs (n = 32) and 11 dogs with pacing-induced cardiac failure (n = 26). Muscles were stretched to maximum length at 30 degrees C and stimulated at 0.33 Hz; a subset (n = 17 control, n = 17 myopathic) was loaded with the [Ca2+]i indicator aequorin. Peak tension was depressed in the myopathic muscles, even in the presence of maximally effective (i.e., 16 mM) [Ca2+] in the perfusate. However, peak [Ca2+]i was similar (0.80 +/- 0.13 vs. 0.71 +/- 0.05 microM; [Ca2+]o = 2.5 mM), suggesting that a decrease in Cai2+ availability was not responsible for the decreased contractility. The time for decline from the peak of the Cai2+ transient was prolonged in the myopathic group, which correlated with prolongation of isometric contraction and relaxation. However, similar end-diastolic [Ca2+]i was achieved in both groups (0.29 +/- 0.05 vs. 0.31 +/- 0.02 microM), indicating that Cai2+ homeostasis can be maintained in myopathic hearts. The inotropic response of the myopathic muscles to milrinone was depressed compared with the controls. However, when cAMP production was stimulated by pretreatment with forskolin, the response of the myopathic muscles to milrinone was improved. Our findings provide direct evidence that abnormal [Ca2+]i handling is an important cause of contractile dysfunction in dogs with pacing-induced heart failure and suggest that deficient production of cAMP may be an important cause of these changes in excitation-contraction coupling.

  10. Coupled Nitrogen and Calcium Cycling in Forests across a Gradient of Soil Nitrogen Availability

    NASA Astrophysics Data System (ADS)

    Perakis, S.; Maguire, D.; Bullen, T.; Cromack, K.; Waring, R.; Boyle, J.

    2004-05-01

    Nitrogen (N) is a critical limiting nutrient that regulates plant productivity and the cycling of essential base cations in forests. Increases in N availability beyond the threshold of plant and ecosystem needs may drive non-linear biogeochemical changes that include excess nitrate leaching and base cation depletion from soils. While such variations in N cycling are typically associated with polluted regions, comparable changes may also occur in unpolluted forests of the Pacific Northwest due to legacies of soil N enrichment from biological N fixation in red alder. We sampled 22 young Douglas-fir stands in the Oregon Coast Range, and found that surface soil calcium (Ca) and magnesium (Mg) concentrations were inversely related to N across a gradient from 0.15 to 1.1 soil %N. Strontium isotope ratios indicate that N-rich forests are decoupled from weathering, and obtain > 97% of base cation nutrition from marine sea-salt aerosols. However, high Ca:Mg ratios of plant demands relative to aerosol inputs selectively fosters Ca deficiency at high soil N. Plant and soil patterns were similar for sandstone versus basalt derived soils, indicating that biological N availability - not bedrock - can be the primary control of coupled N and base cation cycling across areas of high N enrichment.

  11. Calcium.

    PubMed

    Williams, Robert J P

    2002-01-01

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

  12. Investigation of duty cycle effect on corrosion properties of electrodeposited calcium phosphate coatings.

    PubMed

    Azem, Funda Ak; Delice, Tulay Koc; Ungan, Guler; Cakir, Ahmet

    2016-11-01

    The bioceramic calcium phosphate (CaP) is frequently used for improving bone fixation in titanium medical implants and thus increasing lifetime of the implant. It is known that the application of CaP coatings on metallic implant devices offers the possibility of combining the strength of the metals and the bioactivity of the ceramic materials. Many different techniques are available for producing CaP coatings. Electrochemical deposition method is widely used because of its ease of operation parameters, low temperature requirement, reproducibility and suitability for coating complex structures. This technique allows obtaining CaP coatings which promote bone in growth during the first healing period leading to permanent fixation. Electrochemical pulse technique is an alternative to calcium phosphate deposition techniques usually employed to cover orthopedic or dental titanium implant surfaces. Additionally, pulse electrodeposition technique can produce more uniform and denser CaP coatings on metallic implants. In this study, CaP based coatings were produced by electrochemical pulse technique on Ti6Al4V substrates. The resulting CaP deposits were investigated by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Corrosion properties of the CaP coatings were also investigated. The results showed that various duty cycle ranges have remarkably effect on morphology, crystallinity and corrosion properties of the produced CaP coatings. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Myoscape controls cardiac calcium cycling and contractility via regulation of L-type calcium channel surface expression.

    PubMed

    Eden, Matthias; Meder, Benjamin; Völkers, Mirko; Poomvanicha, Montatip; Domes, Katrin; Branchereau, M; Marck, P; Will, Rainer; Bernt, Alexander; Rangrez, Ashraf; Busch, Matthias; Hrabě de Angelis, Martin; Heymes, Christophe; Rottbauer, Wolfgang; Most, Patrick; Hofmann, Franz; Frey, Norbert

    2016-04-28

    Calcium signalling plays a critical role in the pathogenesis of heart failure. Here we describe a cardiac protein named Myoscape/FAM40B/STRIP2, which directly interacts with the L-type calcium channel. Knockdown of Myoscape in cardiomyocytes decreases calcium transients associated with smaller Ca(2+) amplitudes and a lower diastolic Ca(2+) content. Likewise, L-type calcium channel currents are significantly diminished on Myoscape ablation, and downregulation of Myoscape significantly reduces contractility of cardiomyocytes. Conversely, overexpression of Myoscape increases global Ca(2+) transients and enhances L-type Ca(2+) channel currents, and is sufficient to restore decreased currents in failing cardiomyocytes. In vivo, both Myoscape-depleted morphant zebrafish and Myoscape knockout (KO) mice display impairment of cardiac function progressing to advanced heart failure. Mechanistically, Myoscape-deficient mice show reduced L-type Ca(2+)currents, cell capacity and calcium current densities as a result of diminished LTCC surface expression. Finally, Myoscape expression is reduced in hearts from patients suffering of terminal heart failure, implying a role in human disease.

  14. Role of calcium cycling versus restitution in the mechanism of repolarization alternans.

    PubMed

    Pruvot, Etienne J; Katra, Rodolphe P; Rosenbaum, David S; Laurita, Kenneth R

    2004-04-30

    T-wave alternans, a powerful marker of arrhythmic events, results from alternation in action potential duration (APD). The underlying cellular mechanism of APD alternans is unknown but has been attributed to either intracellular calcium (Ca2+) cycling or membrane ionic currents, manifested by a steep slope of cellular APD restitution. To address these mechanisms, high-resolution optical mapping techniques were used to measure action potentials and Ca2+ transients simultaneously from hundreds of epicardial sites in the guinea pig model of pacing-induced T-wave alternans (n=7). The pacing rates (ie, alternans threshold) at which T-wave (369+/-11 bpm), APD (369+/-21 bpm), and Ca2+ (371+/-29 bpm) alternans first appeared were comparable. Importantly, the site of origin of APD alternans and Ca2+ alternans consistently occurred together near the base of the left ventricle, not where APD restitution was steepest. In addition, APD and Ca2+ alternans were remarkably similar both spatially and temporally during discordant alternans. In conclusion, the mechanism underlying T-wave alternans in the intact heart is more closely associated with intracellular Ca2+ cycling rather than APD restitution.

  15. Mitochondria-derived ROS bursts disturb Ca2+ cycling and induce abnormal automaticity in guinea pig cardiomyocytes: a theoretical study

    PubMed Central

    Li, Qince; Su, Di; O'Rourke, Brian; Pogwizd, Steven M.

    2014-01-01

    Mitochondria are in close proximity to the redox-sensitive sarcoplasmic reticulum (SR) Ca2+ release [ryanodine receptors (RyRs)] and uptake [Ca2+-ATPase (SERCA)] channels. Thus mitochondria-derived reactive oxygen species (mdROS) could play a crucial role in modulating Ca2+ cycling in the cardiomyocytes. However, whether mdROS-mediated Ca2+ dysregulation translates to abnormal electrical activities under pathological conditions, and if yes what are the underlying ionic mechanisms, have not been fully elucidated. We hypothesize that pathological mdROS induce Ca2+ elevation by modulating SR Ca2+ handling, which activates other Ca2+ channels and further exacerbates Ca2+ dysregulation, leading to abnormal action potential (AP). We also propose that the morphologies of elicited AP abnormality rely on the time of mdROS induction, interaction between mitochondria and SR, and intensity of mitochondrial oxidative stress. To test the hypotheses, we developed a multiscale guinea pig cardiomyocyte model that incorporates excitation-contraction coupling, local Ca2+ control, mitochondrial energetics, and ROS-induced ROS release. This model, for the first time, includes mitochondria-SR microdomain and modulations of mdROS on RyR and SERCA activities. Simulations show that mdROS bursts increase cytosolic Ca2+ by stimulating RyRs and inhibiting SERCA, which activates the Na+/Ca2+ exchanger, Ca2+-sensitive nonspecific cationic channels, and Ca2+-induced Ca2+ release, eliciting abnormal AP. The morphologies of AP abnormality are largely influenced by the time interval among mdROS burst induction and AP firing, dosage and diffusion of mdROS, and SR-mitochondria distance. This study defines the role of mdROS in Ca2+ overload-mediated cardiac arrhythmogenesis and underscores the importance of considering mitochondrial targets in designing new antiarrhythmic therapies. PMID:25539710

  16. Mice deficient in GEM GTPase show abnormal glucose homeostasis due to defects in beta-cell calcium handling.

    PubMed

    Gunton, Jenny E; Sisavanh, Mary; Stokes, Rebecca A; Satin, Jon; Satin, Leslie S; Zhang, Min; Liu, Sue M; Cai, Weikang; Cheng, Kim; Cooney, Gregory J; Laybutt, D Ross; So, Trina; Molero, Juan-Carlos; Grey, Shane T; Andres, Douglas A; Rolph, Michael S; Mackay, Charles R

    2012-01-01

    Glucose-stimulated insulin secretion from beta-cells is a tightly regulated process that requires calcium flux to trigger exocytosis of insulin-containing vesicles. Regulation of calcium handling in beta-cells remains incompletely understood. Gem, a member of the RGK (Rad/Gem/Kir) family regulates calcium channel handling in other cell types, and Gem over-expression inhibits insulin release in insulin-secreting Min6 cells. The aim of this study was to explore the role of Gem in insulin secretion. We hypothesised that Gem may regulate insulin secretion and thus affect glucose tolerance in vivo. Gem-deficient mice were generated and their metabolic phenotype characterised by in vivo testing of glucose tolerance, insulin tolerance and insulin secretion. Calcium flux was measured in isolated islets. Gem-deficient mice were glucose intolerant and had impaired glucose stimulated insulin secretion. Furthermore, the islets of Gem-deficient mice exhibited decreased free calcium responses to glucose and the calcium oscillations seen upon glucose stimulation were smaller in amplitude and had a reduced frequency. These results suggest that Gem plays an important role in normal beta-cell function by regulation of calcium signalling.

  17. Mice Deficient in GEM GTPase Show Abnormal Glucose Homeostasis Due to Defects in Beta-Cell Calcium Handling

    PubMed Central

    Gunton, Jenny E.; Sisavanh, Mary; Stokes, Rebecca A.; Satin, Jon; Satin, Leslie S.; Zhang, Min; Liu, Sue M.; Cai, Weikang; Cheng, Kim; Cooney, Gregory J.; Laybutt, D. Ross; So, Trina; Molero, Juan-Carlos; Grey, Shane T.; Andres, Douglas A.

    2012-01-01

    Aims and Hypothesis Glucose-stimulated insulin secretion from beta-cells is a tightly regulated process that requires calcium flux to trigger exocytosis of insulin-containing vesicles. Regulation of calcium handling in beta-cells remains incompletely understood. Gem, a member of the RGK (Rad/Gem/Kir) family regulates calcium channel handling in other cell types, and Gem over-expression inhibits insulin release in insulin-secreting Min6 cells. The aim of this study was to explore the role of Gem in insulin secretion. We hypothesised that Gem may regulate insulin secretion and thus affect glucose tolerance in vivo. Methods Gem-deficient mice were generated and their metabolic phenotype characterised by in vivo testing of glucose tolerance, insulin tolerance and insulin secretion. Calcium flux was measured in isolated islets. Results Gem-deficient mice were glucose intolerant and had impaired glucose stimulated insulin secretion. Furthermore, the islets of Gem-deficient mice exhibited decreased free calcium responses to glucose and the calcium oscillations seen upon glucose stimulation were smaller in amplitude and had a reduced frequency. Conclusions These results suggest that Gem plays an important role in normal beta-cell function by regulation of calcium signalling. PMID:22761801

  18. The role of the cilium in normal and abnormal cell cycles: emphasis on renal cystic pathologies

    PubMed Central

    Pan, Junmin; Seeger-Nukpezah, Tamina; Golemis, Erica A.

    2013-01-01

    The primary cilium protrudes from the cell surface and acts as a sensor for chemical and mechanical growth cues, with receptors for a number of growth factors (PDGFα, Hedgehog, Wnt, Notch) concentrated within the ciliary membrane. In normal tissues, the cilium assembles after cells exit mitosis and is resorbed as part of cell cycle re-entry. Although regulation of the cilium by cell cycle transitions has been appreciated for over 100 years, only recently have data emerged to indicate the cilium also exerts influence on the cell cycle. The resorption/protrusion cycle, regulated by proteins including Aurora-A, VHL, and GSK-3β, influences cell responsiveness to growth cues involving cilia-linked receptors; further, resorption liberates the ciliary basal body to differentiate into the centrosome, which performs discrete functions in S-, G2-, and M-phase. Besides these roles, the cilium provides a positional cue that regulates polarity of cell division, and thus directs cells towards fates of differentiation versus proliferation. In this review, we summarize the specific mechanisms mediating the cilia-cell cycle dialog. We then emphasize the examples of polycystic kidney disease (PKD), nephronopthisis (NPHP), and VHL-linked renal cysts as cases in which defects of ciliary function influence disease pathology, and may also condition response to treatment. PMID:22782110

  19. Chronic maternal calcium and 25-hydroxyvitamin D deficiency in Wistar rats programs abnormal hepatic gene expression leading to hepatic steatosis in female offspring.

    PubMed

    Sharma, Sona S; Jangale, Nivedita M; Harsulkar, Abhay M; Gokhale, Medha K; Joshi, Bimba N

    2017-02-08

    Importance of calcium and vitamin D deficiency is well established in adult dyslipidemia. We hypothesized that maternal calcium and vitamin D deficiency could alter offspring's lipid metabolism. Our objective was to investigate the effect of maternal dietary calcium and vitamin D deficiency on lipid metabolism and liver function of the F1 generation offspring. intergenerational calcium-deficient (CaD) and vitamin D-deficient (VDD) models were developed by mating normal male rats with deficient females and continuing maternal-deficient diets through pregnancy and lactation. Offspring were fed on control diet post-weaning and studied till 30 weeks. Lipid profile, serum glutamate pyruvate transaminase (SGPT), calcium and vitamin D levels were analyzed. Liver fat deposition, omega-3 fatty acids level and mRNA expression levels of peroxisome proliferator-activated receptor-alpha (PPAR-α), sterol regulatory element-binding protein 1c (SREBP-1c), interleukin 6 (IL-6), superoxide dismutase 1 (SOD-1) and uncoupling protein 2 (UCP2) were determined. Low serum vitamin D levels with an increase in SGPT and TG levels in CaD and VDD female offspring were observed. Severe liver steatosis with down-regulation of PPAR-α and UCP2 and up-regulation of SREBP-1c, IL-6 and SOD-1 was observed in the female offspring born to deficient dams. CaD and VDD male offspring showed mild steatosis and down-regulation of UCP2 and SOD-1. We conclude that maternal calcium and vitamin D deficiency programs abnormal lipid metabolism and hepatic gene expression in the F1 generation female offspring leading to hepatic steatosis, despite feeding them on control diet post-weaning.

  20. Abnormal calcium metabolism in myotonic dystrophy as shown by the Ellsworth-Howard test and its relation to CTG triplet repeat length.

    PubMed

    Kinoshita, M; Komori, T; Ohtake, T; Takahashi, R; Nagasawa, R; Hirose, K

    1997-10-01

    Myotonic dystrophy (DM) is an autosomal dominant disorder characterized by peculiar clinical features. Its molecular basis is the unstable expansion of a CTG triplet repeat in the gene encoding myotonin protein kinase (Mt-PK), the nucleotide sequence of which has extensive homology to the cyclic AMP (cAMP)-dependent protein kinase gene. Extensive efforts have been made to clarify the signal transduction pathway in which the responsible gene operates, but confirming evidence has yet to be obtained. Because some symptoms in DM are similar to those in hypoparathyroidism, we divided 24 DM patients into two groups on the basis of their serum calcium levels; Group 1, those with normocalcemia (11 patients), and group 2, those with hypocalcemia (13 patients). The highly sensitive parathyroid hormone (HS-PTH) plasma levels in group 1 were within normal limits, whereas those in group 2 were abnormally high. Laboratory findings for the group 2 patients resembled those for pseudohypoparathyroidism (PHP), whereas those for group 1 patients were normal. The Ellsworth-Howard (EH) test was used to determine which type of PHP the group 2 patients belonged to. Both the phosphaturic (delta P) and urinary cAMP (UcAMP) responses were estimated. The delta P responses in group 2 were significantly lower than those in group 1, but their UcAMP responses did not differ. This is evidence that group 2 patients had PHP type II, whereas group 1 patients were normal. We also investigated whether the disease severity differed between the groups. Cataracts, ectopic calcifications, and ossifications, which are associated with PHP, were more frequent in group 2. In addition, the mean IQ in that group was significantly lower. Clinically, the group 2 signs agreed well with those of PHP, whereas for group 1 there was only a slight similarity. These results are additional evidence that the patients in group 2 have abnormal calcium metabolism, the abnormality being in the postadenylate cyclase

  1. Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling

    PubMed Central

    Lumbreras, Vicente; Bas, Esperanza; Gupta, Chhavi

    2014-01-01

    Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca2+ imaging. Both types of neurons responded consistently with robust intracellular Ca2+ ([Ca2+]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25–1 pps). Radiant exposures of ∼637 mJ/cm2 resulted in continual neuronal activation. Temperature or [Ca2+] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca2+ involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na+, K+, and Ca2+ plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca2+ cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca2+]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca2+ release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses. PMID:24920028

  2. Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling.

    PubMed

    Lumbreras, Vicente; Bas, Esperanza; Gupta, Chhavi; Rajguru, Suhrud M

    2014-09-15

    Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ∼637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses.

  3. Deep carbon cycle recorded by calcium-silicate rocks (rodingites) in a subduction-related ophiolite

    NASA Astrophysics Data System (ADS)

    Dai, J. G.; Wang, C. S.; Liu, S. A.; Qian, X. Y.; Zhu, D. C.; Ke, S.

    2016-11-01

    Carbon cycling in subduction zones remains poorly constrained due to the lack of relevant geological records. Here we report magnesium isotope data (δ26MgDSM3) from calcium-silicate rocks (rodingites) from the Xigaze ophiolite, southern Tibet, which is thought to represent remnants of Neo-Tethyan oceanic lithosphere. Behaviors of immobile trace elements in rodingites resemble those of their mafic dike protoliths, showing subduction-related signatures. The majority of rodingites exhibits low δ26Mg values of -0.72‰ to -0.33‰ with a weighted average of -0.47 ± 0.11‰ (2 SD), significantly lighter than that of their protoliths (-0.31 ± 0.03‰). This difference likely reflects the interaction of the protolith with isotopically light carbonate fluids. Modeling indicates that this hypothesis requires the input of 5 to 15 wt % carbonates during rodingitization. Our study suggests that rodingite may represent a previously unrecognized reservoir of dissolved Ca from subducted carbonates.

  4. Store-operated calcium entry contributes to abnormal Ca²⁺ signalling in dystrophic mdx mouse myoblasts.

    PubMed

    Onopiuk, Marta; Brutkowski, Wojciech; Young, Christopher; Krasowska, Elżbieta; Róg, Justyna; Ritso, Morten; Wojciechowska, Sylwia; Arkle, Stephen; Zabłocki, Krzysztof; Górecki, Dariusz C

    2015-03-01

    Sarcolemma damage and activation of various calcium channels are implicated in altered Ca(2+) homeostasis in muscle fibres of both Duchenne muscular dystrophy (DMD) sufferers and in the mdx mouse model of DMD. Previously we have demonstrated that also in mdx myoblasts extracellular nucleotides trigger elevated cytoplasmic Ca(2+) concentrations due to alterations of both ionotropic and metabotropic purinergic receptors. Here we extend these findings to show that the mdx mutation is associated with enhanced store-operated calcium entry (SOCE). Substantially increased rate of SOCE in mdx myoblasts in comparison to that in control cells correlated with significantly elevated STIM1 protein levels. These results reveal that mutation in the dystrophin-encoding Dmd gene may significantly impact cellular calcium response to metabotropic stimulation involving depletion of the intracellular calcium stores followed by activation of the store-operated calcium entry, as early as in undifferentiated myoblasts. These data are in agreement with the increasing number of reports showing that the dystrophic pathology resulting from dystrophin mutations may be developmentally regulated. Moreover, our results showing that aberrant responses to extracellular stimuli may contribute to DMD pathogenesis suggest that treatments inhibiting such responses might alter progression of this lethal disease.

  5. Complex cell cycle abnormalities caused by human T-lymphotropic virus type 1 Tax.

    PubMed

    Yang, Liangpeng; Kotomura, Naoe; Ho, Yik-Khuan; Zhi, Huijun; Bixler, Sandra; Schell, Michael J; Giam, Chou-Zen

    2011-03-01

    Human T-lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma (ATL), a malignancy of CD4(+) T cells whose etiology is thought to be associated with the viral trans-activator Tax. We have shown recently that Tax can drastically upregulate the expression of p27(Kip1) and p21(CIP1/WAF1) through protein stabilization and mRNA trans-activation and stabilization, respectively. The Tax-induced surge in p21(CIP1/WAF1) and p27(Kip1) begins in S phase and results in cellular senescence. Importantly, HeLa and SupT1 T cells infected by HTLV-1 also arrest in senescence, thus challenging the notion that HTLV-1 infection causes cell proliferation. Here we use time-lapse microscopy to investigate the effect of Tax on cell cycle progression in two reporter cell lines, HeLa/18x21-EGFP and HeLa-FUCCI, that express enhanced green fluorescent protein (EGFP) under the control of 18 copies of the Tax-responsive 21-bp repeat element and fluorescent ubiquitin cell cycle indicators, respectively. Tax-expressing HeLa cells exhibit elongated or stalled cell cycle phases. Many of them bypass mitosis and become single senescent cells as evidenced by the expression of senescence-associated β-galactosidase. Such cells have twice the normal equivalent of cellular contents and hence are enlarged, with exaggerated nuclei. Interestingly, nocodazole treatment revealed a small variant population of HeLa/18x21-EGFP cells that could progress into mitosis normally with high levels of Tax expression, suggesting that genetic or epigenetic changes that prevent Tax-induced senescence can occur spontaneously at a detectable frequency.

  6. Coupled nitrogen and calcium cycling in forests of the Oregon Coast Range

    USGS Publications Warehouse

    Perakis, Steven S.; Maguire, Douglas A.; Bullen, Thomas D.; Cromack, Kermit; Waring, Richard H.; Boyle, James R.

    2006-01-01

    Nitrogen (N) is a critical limiting nutrient that regulates plant productivity and the cycling of other essential elements in forests. We measured foliar and soil nutrients in 22 young Douglas-fir stands in the Oregon Coast Range to examine patterns of nutrient availability across a gradient of N-poor to N-rich soils. N in surface mineral soil ranged from 0.15 to 1.05% N, and was positively related to a doubling of foliar N across sites. Foliar N in half of the sites exceeded 1.4% N, which is considered above the threshold of N-limitation in coastal Oregon Douglas-fir. Available nitrate increased five-fold across this gradient, whereas exchangeable magnesium (Mg) and calcium (Ca) in soils declined, suggesting that nitrate leaching influences base cation availability more than soil parent material across our sites. Natural abundance strontium isotopes (87Sr/86Sr) of a single site indicated that 97% of available base cations can originate from atmospheric inputs of marine aerosols, with negligible contributions from weathering. Low annual inputs of Ca relative to Douglas-fir growth requirements may explain why foliar Ca concentrations are highly sensitive to variations in soil Ca across our sites. Natural abundance calcium isotopes (I'44Ca) in exchangeable and acid leachable pools of surface soil measured at a single site showed 1 per mil depletion relative to deep soil, suggesting strong Ca recycling to meet tree demands. Overall, the biogeochemical response of these Douglas-fir forests to gradients in soil N is similar to changes associated with chronic N deposition in more polluted temperate regions, and raises the possibility that Ca may be deficient on excessively N-rich sites. We conclude that wide gradients in soil N can drive non-linear changes in base-cation biogeochemistry, particularly as forests cross a threshold from N-limitation to N-saturation. The most acute changes may occur in forests where base cations are derived principally from atmospheric

  7. Coupled nitrogen and calcium cycles in forests of the Oregon Coast Range

    USGS Publications Warehouse

    Perakis, S.S.; Maguire, D.A.; Bullen, T.D.; Cromack, K.; Waring, R.H.; Boyle, J.R.

    2006-01-01

    Nitrogen (N) is a critical limiting nutrient that regulates plant productivity and the cycling of other essential elements in forests. We measured foliar and soil nutrients in 22 young Douglas-fir stands in the Oregon Coast Range to examine patterns of nutrient availability across a gradient of N-poor to N-rich soils. N in surface mineral soil ranged from 0.15 to 1.05% N, and was positively related to a doubling of foliar N across sites. Foliar N in half of the sites exceeded 1.4% N, which is considered above the threshold of N-limitation in coastal Oregon Douglas-fir. Available nitrate increased five-fold across this gradient, whereas exchangeable magnesium (Mg) and calcium (Ca) in soils declined, suggesting that nitrate leaching influences base cation availability more than soil parent material across our sites. Natural abundance strontium isotopes (87Sr/86Sr) of a single site indicated that 97% of available base cations can originate from atmospheric inputs of marine aerosols, with negligible contributions from weathering. Low annual inputs of Ca relative to Douglas-fir growth requirements may explain why foliar Ca concentrations are highly sensitive to variations in soil Ca across our sites. Natural abundance calcium isotopes (??44Ca) in exchangeable and acid leachable pools of surface soil measured at a single site showed 1 per mil depletion relative to deep soil, suggesting strong Ca recycling to meet tree demands. Overall, the biogeochemical response of these Douglas-fir forests to gradients in soil N is similar to changes associated with chronic N deposition in more polluted temperate regions, and raises the possibility that Ca may be deficient on excessively N-rich sites. We conclude that wide gradients in soil N can drive non-linear changes in base-cation biogeochemistry, particularly as forests cross a threshold from N-limitation to N-saturation. The most acute changes may occur in forests where base cations are derived principally from atmospheric

  8. Metabonomic analysis of hepatitis E patients shows deregulated metabolic cycles and abnormalities in amino acid metabolism.

    PubMed

    Munshi, S U; Taneja, S; Bhavesh, N S; Shastri, J; Aggarwal, R; Jameel, S

    2011-10-01

    Hepatitis E, which is endemic to resource-poor regions of the world, is largely an acute and self-limiting disease, but some patients have an increased susceptibility to develop fulminant hepatitis. The pathogenesis of hepatitis E in humans is poorly characterized. To understand the metabolic pathways involved in the pathophysiology of hepatitis E, we have used (1) H nuclear magnetic resonance spectroscopy to quantify various metabolites in the plasma and urine of the patients with hepatitis E. These were compared with specimens from patients with acute hepatitis B as disease controls and healthy volunteers. Data were analysed using chemometric statistical methods and metabolite databases. The main metabonomic changes found in patients with hepatitis E, but not in those with hepatitis B, included increased plasma levels of L-isoleucine, acetone, and glycerol, reduced plasma levels of glycine, and reduced urinary levels of imidazole, 3-aminoisobutanoic acid, 1-methylnicotinamide, biopterin, adenosine, 1-methylhistidine, and salicyluric acid. Patients with hepatitis E or B both showed increased levels of plasma and urinary L-proline and decreased levels of various other metabolites. Pathway analysis tools suggest the involvement of glycolysis, tricarboxylic acid cycle, urea cycle, and amino acid metabolism in patients with acute hepatitis E. These findings may help better understand the clinical and biochemical manifestations in this disease and the underlying pathophysiologic processes. Based on our findings, it would be worthwhile determining whether patients with hepatitis E are more prone to develop lactic acidosis and ketosis compared with other forms of viral hepatitis. © 2011 Blackwell Publishing Ltd.

  9. The Transient Role for Calcium and Vitamin D during the Developmental Hair Follicle Cycle.

    PubMed

    Mady, Leila J; Ajibade, Dare V; Hsaio, Connie; Teichert, Arnaud; Fong, Chak; Wang, Yongmei; Christakos, Sylvia; Bikle, Daniel D

    2016-07-01

    The role for 1,25-dihydroxyvitamin D3 and/or calcium in hair follicle cycling is not clear despite their impact on keratinocyte differentiation. We found that calbindin-D9k null (knockout) pups generated from calbindin-D9k knockout females fed a vitamin D-deficient, low-calcium (0.47%) diet develop transient alopecia. The pups appear phenotypically normal until 13 days of age, after which the hair progressively sheds in a caudocephalic direction, resulting in truncal alopecia totalis by 20-23 days, with spontaneous recovery by 28 days. Histological studies showed markedly dystrophic hair follicles, loss of hair shafts with increased apoptosis, and hyperplastic epidermis during this time. Ha1 expression is lost during catagen in all mice but recovers more slowly in the knockout pups on the vitamin D-deficient, low-calcium diet. Keratin 1 expression is reduced throughout days 19-28. The expressions of involucrin, loricrin, and cathepsin L is initially increased by day 19 but subsequently falls below those of controls by day 23, as does that of desmoglein 3. Feeding the mothers a high-vitamin D/high-calcium (2%)/lactose (20%) diet lessens the phenotype, and knockout pups fostered to mothers fed a normal diet do not develop alopecia. Our results show that in calbindin-D9k knockout pups, a maternal vitamin D-deficient/low-calcium diet leads to transient noncicatricial alopecia. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Is my period normal? How college-aged women determine the normality or abnormality of their menstrual cycles.

    PubMed

    Wood, Jill M; Barthalow Koch, Patricia; Mansfield, Phyllis Kernoff

    2007-01-01

    The purpose of this descriptive, qualitative study was to explore young adult women's conceptualizations of their menstruation experiences using a feminist approach. Grounded theory was used to understand how 15 college-aged women (ages 18-22 years, 86% white) evaluate their menstrual patterns as "normal" or "abnormal." Data analysis of the semi-structured interviews revealed four themes that the women used to judge the pattern of their menstruation (i.e., interval, duration, discomfort, and volume) as normal: (1) Pattern resembled learned norms, (2) consistent pattern discordant from learned norms, (3) predictably variable pattern, and (4) absence of problems. Two distinct themes informed their decisions to consider a menstrual pattern as abnormal: (1) Unpredictable variability, and (2) extreme experiences. The core variable emerging from data analysis, establishing a personal norm, illuminated the two major sources that women relied on in trying to interpret their menstrual patterns: the limited and often inaccurate information that they had been taught and their own menstrual experiences. Implications include the need to improve education about menstrual variability throughout the life cycle and about the diversity of women's normal menstrual patterns and experiences.

  11. Heterogeneous abnormalities of in-vivo left ventricular calcium influx and function in mouse models of muscular dystrophy cardiomyopathy.

    PubMed

    Greally, Elizabeth; Davison, Benjamin J; Blain, Alison; Laval, Steve; Blamire, Andrew; Straub, Volker; MacGowan, Guy A

    2013-01-16

    Manganese-enhanced cardiovascular magnetic resonance (MECMR) can non-invasively assess myocardial calcium influx, and calcium levels are known to be elevated in muscular dystrophy cardiomyopathy based on cellular studies. Left ventricular functional studies and MECMR were performed in mdx mice (model of Duchenne muscular dystrophy, 24 and 40 weeks) and Sgcd -/- mice (limb girdle muscular dystrophy 2 F, 16 and 32 weeks), compared to wild type controls (C57Bl/10, WT). Both models had left ventricular hypertrophy at the later age compared to WT, though the mdx mice had reduced stroke volumes and the Sgcd -/- mice increased heart rate and cardiac index. Especially at the younger ages, MECMR was significantly elevated in both models (both P < 0.05 versus WT). The L-type calcium channel inhibitor diltiazem (5 mg/kg i.p.) significantly reduced MECMR in the mdx mice (P < 0.01), though only with a higher dose (10 mg/kg i.p.) in the Sgcd -/- mice (P < 0.05). As the Sgcd -/- mice had increased heart rates, to determine the role of heart rate in MECMR we studied the hyperpolarization-activated cyclic nucleotide-gated channel inhibitor ZD 7288 which selectively reduces heart rate. This reduced heart rate and MECMR in all mouse groups. However, when looking at the time course of reduction of MECMR in the Sgcd -/- mice at up to 5 minutes of the manganese infusion when heart rates were matched to the WT mice, MECMR was still significantly elevated in the Sgcd -/- mice (P < 0.01) indicating that heart rate alone could not account for all the increased MECMR. Despite both mouse models exhibiting increased in-vivo calcium influx at an early stage in the development of the cardiomyopathy before left ventricular hypertrophy, there are distinct phenotypical differences between the 2 models in terms of heart rates, hemodynamics and responses to calcium channel inhibitors.

  12. New insights into the mechanism of abnormal calcification in nephrogenic systemic fibrosis - gadolinium promotes calcium deposition of mesenchymal stem cells and dermal fibroblasts.

    PubMed

    Okada, Etsuko; Yamanaka, Masayoshi; Ishikawa, Osamu

    2011-04-01

    Recent studies have suggested that there is a close association between the administration of gadolinium (Gd)-based contrast agents and the development of nephrogenic systemic fibrosis (NSF), an acquired disorder characterized by systemic fibrosis and abnormal calcification in patients with severe renal dysfunction. However, the causative roles of Gd remain unknown. The aim of this in vitro study was to investigate the effect of Gd on the development of fibrosis and calcification in cultured cells. MC3T3-E1 cells (pre-osteoblastic cells), human adipose tissue-derived mesenchymal stem cells (HAMSCs), human subcutaneous preadipocytes, and human dermal fibroblasts (HDFs) were each cultured in differentiation medium with or without gadolinium chloride. Calcium deposition of MC3T3-E1 cells, HAMSCs, and HDFs was determined by alzarin red S staining. Adipogenic differentiation of human subcutaneous preadipocytes and HAMSCs was determined by oil red O staining. Fibrogenesis of HDFs was determined by real-time PCR to measure the mRNA expression of type I collagen. Cell proliferation was determined by MTS assay. Gd induced calcium deposition in MC3T3-E1 cells, HAMSCs and HDFs in osteogenic differentiation media. Gd did not induce adipogenic differentiation in human subcutaneous preadipocytes and HAMSCs. Gd did not increase the mRNA expression of type I collagen in HDFs, but did promote cell proliferation. We have demonstrated a direct effect of Gd on calcium deposition in cultured cells. The result will help us to understand the mechanism of abnormal calcification in NSF. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  13. Myoadenylate deaminase deficiency. Functional and metabolic abnormalities associated with disruption of the purine nucleotide cycle.

    PubMed Central

    Sabina, R L; Swain, J L; Olanow, C W; Bradley, W G; Fishbein, W N; DiMauro, S; Holmes, E W

    1984-01-01

    To assess the role of the purine nucleotide cycle in human skeletal muscle function, we evaluated 10 patients with AMP deaminase deficiency (myoadenylate deaminase deficiency; MDD). 4 MDD and 19 non-MDD controls participated in an exercise protocol. The latter group was composed of a patient cohort (n = 8) exhibiting a constellation of symptoms similar to those of the MDD patients, i.e., postexertional aches, cramps, and pains; as well as a cohort of normal, unconditioned volunteers (n = 11). The individuals with MDD fatigued after performing only 28% as much work as their non-MDD counterparts. Muscle biopsies were obtained from the four MDD patients and the eight non-MDD patients at rest and following exercise to the point of fatigue. Creatine phosphate content fell to a comparable extent in the MDD (69%) and non-MDD (52%) patients at the onset of fatigue. Following exercise the 34% decrease in ATP content of muscle from the non-MDD subjects was significantly greater than the 6% decrease in ATP noted in muscle from the MDD patients (P = 0.048). Only one of four MDD patients had a measurable drop in ATP compared with seven of eight non-MDD patients. At end-exercise the muscle content of inosine 5'-monophosphate (IMP), a product of AMP deaminase, was 13-fold greater in the non-MDD patients than that observed in the MDD group (P = 0.008). Adenosine content of muscle from the MDD patients increased 16-fold following exercise, while there was only a twofold increase in adenosine content of muscle from the non-MDD patients (P = 0.028). Those non-MDD patients in whom the decrease in ATP content following exercise was measurable exhibited a stoichiometric increase in IMP, and total purine content of the muscle did not change significantly. The one MDD patient in whom the decrease in ATP was measurable, did not exhibit a stoichiometric increase in IMP. Although the adenosine content increased 13-fold in this patient, only 48% of the ATP catabolized could be accounted for

  14. Oxidation of carbon sources via the tricarboxylic acid cycle during calcium-induced conidiation of Penicillium notatum.

    PubMed

    Pitt, D; Mosley, M J

    1986-01-01

    The TCA cycle was examined during Ca2+-induced conidiation in Penicillium notatum over the 12-h period after addition of Ca2+ to vegetative cultures. Conidiation was independent of Ca2+ when certain intermediates and derivatives of the TCA cycle served as sole carbon sources. Arsenite and malonate augmented the effect of Ca2+ on conidiation but did not substitute for it. Mitochondria from vegetative cells had low rates of oxidation of TCA cycle intermediates and, with the exception of pyruvate, aconitate and glutamate, these were poorly linked to phosphorylation processes. Calcium ions affected mitochondrial function causing reduced oxidation of oxoglutarate, elimination of pyruvate oxidation and a decline in respiratory control of these substrates with increased oxidation of NADH and NADPH. Radiorespirometric studies and enzyme searches revealed a complete but weakly oxidative TCA cycle in vegetative cells. In Ca2+-induced cells oxoglutarate dehydrogenase activity was deleted within 6.5 h of Ca2+ addition and this was accompanied by establishment of an 'incomplete Krebs cycle'. Calcium-induced conidiation was associated with increased capacity for acetate and glutamate metabolism involving an activated glyoxylate shunt which may be related to enhanced biosynthetic demand. The metabolic basis of the Ca2+ effect on conidiation is discussed in connection with previous findings.

  15. Deep Carbon Cycle Recorded by Calcium-Enriched Rodingite in the Subduction-Related Ophiolite

    NASA Astrophysics Data System (ADS)

    Dai, J.; Wang, C.; Shengao, L.; Zhu, D. C.; Ke, S.

    2016-12-01

    Carbon dioxide (CO2) emission from subduction zones influences both the present and ancient Earth's atmosphere. However, carbon cycling in subduction zones remains poorly constrained because of the lacking of related geological records. Here we report magnesium isotope data (δ26MgDSM3) for calcium-enriched rodingites from the Xigaze ophiolite, southern Tibet, which was thought to represent remnants of Neo-Tethyan oceanic lithosphere. Behaviors of immobile trace elements of rodingites resemble those of mafic dikes of their protoliths, showing subduction-related signatures. The majority of rodingites exhibits low δ26Mg values of -0.72‰ to -0.33‰ with a weight average of -0.47 ± 0.11‰ (2sd) significantly lighter than that of their protolith (-0.31± 0.01‰). This difference likely reflects the interaction of their protoliths with isotopically light carbonate fluids. Modeling indicates that this requires the input of 0.6 to 15 wt.% carbonates during the rodingitization, corresponding to total weight percent of 0.04% to 0.89% carbonates involved into the mantle wedge given 5.9% of rodingites in the mantle. The substantial involvement of marine carbonates along the Neo-Tethyan subduction zones into the mantle wedge, which were subsequently released via volcanism, might have been a critical factor that contributed to late Cretaceous global Greenhouse. Our study suggests that rodingites in ophiolites might be one of potential reservoirs for dissolved CaCO3 that has not been recognized so far.

  16. The Abnormal Phenotypes of Cartilage and Bone in Calcium-Sensing Receptor Deficient Mice Are Dependent on the Actions of Calcium, Phosphorus, and PTH

    PubMed Central

    Tao, Chunxiang; Ding, Guoxian; Karaplis, Andrew; Brown, Edward; Goltzman, David; Miao, Dengshun

    2011-01-01

    Patients with neonatal severe hyperparathyroidism (NSHPT) are homozygous for the calcium-sensing receptor (CaR) mutation and have very high circulating PTH, abundant parathyroid hyperplasia, and severe life-threatening hypercalcemia. Mice with homozygous deletion of CaR mimic the syndrome of NSHPT. To determine effects of CaR deficiency on skeletal development and interactions between CaR and 1,25(OH)2D3 or PTH on calcium and skeletal homeostasis, we compared the skeletal phenotypes of homozygous CaR–deficient (CaR−/−) mice to those of double homozygous CaR– and 1α(OH)ase–deficient [CaR−/−1α(OH)ase−/−] mice or those of double homozygous CaR– and PTH–deficient [CaR−/−PTH−/−] mice at 2 weeks of age. Compared to wild-type littermates, CaR−/− mice had hypercalcemia, hypophosphatemia, hyperparathyroidism, and severe skeletal growth retardation. Chondrocyte proliferation and PTHrP expression in growth plates were reduced significantly, whereas trabecular volume, osteoblast number, osteocalcin-positive areas, expression of the ALP, type I collagen, osteocalcin genes, and serum ALP levels were increased significantly. Deletion of 1α(OH)ase in CaR−/− mice resulted in a longer lifespan, normocalcemia, lower serum phosphorus, greater elevation in PTH, slight improvement in skeletal growth with increased chondrocyte proliferation and PTHrP expression, and further increases in indices of osteoblastic bone formation. Deletion of PTH in CaR−/− mice resulted in rescue of early lethality, normocalcemia, increased serum phosphorus, undetectable serum PTH, normalization in skeletal growth with normal chondrocyte proliferation and enhanced PTHrP expression, and dramatic decreases in indices of osteoblastic bone formation. Our results indicate that reductions in hypercalcemia play a critical role in preventing the early lethality of CaR−/− mice and that defects in endochondral bone formation in CaR−/− mice result from effects of the

  17. Abnormal Uterine Bleeding FAQ

    MedlinePlus

    ... PROBLEMS Abnormal Uterine Bleeding • What is a normal menstrual cycle? • When is bleeding abnormal? • At what ages is ... treat abnormal bleeding? •Glossary What is a normal menstrual cycle? The normal length of the menstrual cycle is ...

  18. Isotopic evidence for variations in the marine calcium cycle over the Cenozoic.

    PubMed

    De La Rocha, C L; DePaolo, D J

    2000-08-18

    Significant variations in the isotopic composition of marine calcium have occurred over the last 80 million years. These variations reflect deviations in the balance between inputs of calcium to the ocean from weathering and outputs due to carbonate sedimentation, processes that are important in controlling the concentration of carbon dioxide in the atmosphere and, hence, global climate. The calcium isotopic ratio of paleo-seawater is an indicator of past changes in atmospheric carbon dioxide when coupled with determinations of paleo-pH.

  19. Impact of calcium, phosphate, PTH abnormalities and management on mortality in hemodialysis: results from the RISCAVID study.

    PubMed

    Panichi, Vincenzo; Bigazzi, Roberto; Paoletti, Sabrina; Mantuano, Emanuela; Beati, Sara; Marchetti, Valentina; Bernabini, Giada; Grazi, Giovanni; Giust, Riccardo; Rosati, Alberto; Migliori, Massimiliano; Pasquariello, Antonio; Panicucci, Erica; Barsotti, Giuliano; Bellasi, Antonio

    2010-01-01

    Despite substantial progress in medical care, the mortality rate remains unacceptably high in dialysis patients. Evidence suggests that bone mineral dismetabolism (CKD-MBD) might contribute to this burden of death. However, to date only a few papers have investigated the clinical relevance of serum mineral derangements and the impact of different therapeutic strategies on mortality in a homogeneous cohort of south European dialysis patients. The RISCAVID study was a prospective, observational study in which all patients receiving hemodialysis (HD) in the north-western region of Toscany in June 2004 were enrolled (N=757) and followed up for 24 months. At study entry, only 71 (9%) patients of the entire study cohort exhibited an optimal control of serum phosphorous (Pi), calcium (Ca), calciumX-phosphorous product (CAXPi) and intact parathyroidhormone (iPTH) according to the Kidney Disease Outcomes Quality Initiative (K/DOQI) clinical guidelines. Despite a similar prevalence, the severity of CKD-MBD appeared different to the results reported in the USA. Interestingly, none of the serum biomarkers or number of serum biomarkers within KDOQI targets was independently associated with all-cause and cardiovascular (CV) mortality. Among treatments, Sevelamer was the only drug independently associated with lower all-cause and cardiovascular mortality (p<0.001). The RISCAVID study highlights the difficulty of controlling bone mineral metabolism in HD patients and lends support to the hypothesis that a carefully chosen phosphate binder might impact survival in HD patients.

  20. Tamm-Horsfall protein in recurrent calcium kidney stone formers with positive family history: abnormalities in urinary excretion, molecular structure and function.

    PubMed

    Jaggi, Markus; Nakagawa, Yasushi; Zipperle, Ljerka; Hess, Bernhard

    2007-04-01

    Tamm-Horsfall protein (THP) powerfully inhibits calcium oxalate crystal aggregation, but structurally abnormal THPs from recurrent calcium stone formers may promote crystal aggregation. Therefore, increased urinary excretion of abnormal THP might be of relevance in nephrolithiasis. We studied 44 recurrent idiopathic calcium stone formers with a positive family history of stone disease (RCSF(fam)) and 34 age- and sex-matched healthy controls (C). Twenty-four-hour urinary THP excretion was measured by enzyme linked immunosorbent assay. Structural properties of individually purified THPs were obtained from analysis of elution patterns from a Sepharose 4B column. Sialic acid (SA) contents of native whole 24-h urines, crude salt precipitates of native urines and individually purified THPs were measured. THP function was studied by measuring inhibition of CaOx crystal aggregation in vitro (pH 5.7, 200 mM sodium chloride). Twenty-four-hour urine excretion of THP was higher in RCSF(fam) (44.0 +/- 4.0 mg/day) than in C (30.9 +/- 2.2 mg/day, P = 0.015). Upon salt precipitation and lyophilization, elution from a Sepharose 4B column revealed one major peak (peak A, cross-reacting with polyclonal anti-THP antibody) and a second minor peak (peak B, not cross-reacting). THPs from RCSF(fam) eluted later than those from C (P = 0.021), and maximum width of THP peaks was higher in RCSF(fam )than in C (P = 0.024). SA content was higher in specimens from RCSF(fam) than from C, in native 24-h urines (207.5 +/- 20.4 mg vs. 135.2 +/- 16.1 mg, P = 0.013) as well as in crude salt precipitates of 24-h urines (10.4 +/- 0.5 mg vs. 7.4 +/- 0.9 mg, P = 0.002) and in purified THPs (75.3 +/- 9.3 microg/mg vs. 48.8 +/- 9.8 microg/mg THP, P = 0.043). Finally, inhibition of calcium oxalate monohydrate crystal aggregation by 40 mg/L of THP was lower in RCSF(fam) (6.1 +/- 5.5%, range -62.0 to +84.2%) than in C (24.9 +/- 6.0%, range -39.8 to +82.7%), P = 0.022, and only 25 out of 44 (57%) THPs from RCSF

  1. Quetiapine Inhibits Microglial Activation by Neutralizing Abnormal STIM1-Mediated Intercellular Calcium Homeostasis and Promotes Myelin Repair in a Cuprizone-Induced Mouse Model of Demyelination

    PubMed Central

    Wang, Hanzhi; Liu, Shubao; Tian, Yanping; Wu, Xiyan; He, Yangtao; Li, Chengren; Namaka, Michael; Kong, Jiming; Li, Hongli; Xiao, Lan

    2015-01-01

    Microglial activation has been considered as a crucial process in the pathogenesis of neuroinflammation and psychiatric disorders. Several antipsychotic drugs (APDs) have been shown to display inhibitory effects on microglial activation in vitro, possibly through the suppression of elevated intracellular calcium (Ca2+) concentration. However, the exact underlying mechanisms still remain elusive. In this study, we aimed to investigate the inhibitory effects of quetiapine (Que), an atypical APD, on microglial activation. We utilized a chronic cuprizone (CPZ)-induced demyelination mouse model to determine the direct effect of Que on microglial activation. Our results showed that treatment with Que significantly reduced recruitment and activation of microglia/macrophage in the lesion of corpus callosum and promoted remyelination after CPZ withdrawal. Our in vitro studies also confirmed the direct effect of Que on lipopolysaccharide (LPS)-induced activation of microglial N9 cells, whereby Que significantly inhibited the release of nitric oxide (NO) and tumor necrosis factor α (TNF-α). Moreover, we demonstrated that pretreatment with Que, neutralized the up-regulation of STIM1 induced by LPS and declined both LPS and thapsigargin (Tg)-induced store-operated Ca2+ entry (SOCE). Finally, we found that pretreatment with Que significantly reduced the translocation of nuclear factor kappa B (NF-κB) p65 subunit from cytoplasm to nuclei in LPS-activated primary microglial cells. Overall, our data suggested that Que may inhibit microglial activation by neutralization of the LPS-induced abnormal STIM1-mediated intercellular calcium homeostasis. PMID:26732345

  2. Hereditary urea cycle abnormality

    MedlinePlus

    ... Prenatal testing is available. Genetic testing before an embryo is implanted may be available for those using ... Prenatal testing is available. Genetic testing before an embryo is implanted may be available for those using ...

  3. Implications of sodium mass balance for interpreting the calcium cycle of a forested ecosystem

    Treesearch

    Scott W. Bailey; Donald C. Buso; Gene E. Likens

    2003-01-01

    Disturbance of forest ecosystems, such as that caused by harvesting or acid deposition, is thought to alter the ability of the ecosystem to retain nutrients. Although many watershed studies have suggested depletion of available calcium (Ca) pools, interpretation of ecosystem Ca mass balance has been limited by the difficulty in obtaining mineral weathering flux...

  4. Postprandial heat production in skeletal muscle is associated with altered mitochondrial function and altered futile calcium cycling.

    PubMed

    Clarke, Scott D; Lee, Kevin; Andrews, Zane B; Bischof, Robert; Fahri, Fahri; Evans, Roger G; Clarke, Iain J; Henry, Belinda A

    2012-11-15

    This study aimed to determine whether postprandial temperature excursions in skeletal muscle are consistent with thermogenesis or altered blood flow. Temperature probes were implanted into the vastus lateralis muscle of ovariectomized ewes, and blood flow was assessed using laser-Doppler flowmetry (tissue flow) and transit-time ultrasound flowmetry (femoral artery flow). The animals were program-fed between 1100 and 1600, and temperature and blood flow were measured during intravenous administration of either isoprenaline or phenylephrine and during feeding and meal anticipation. In addition, muscle biopsies were collected prefeeding and postfeeding to measure uncoupling protein (UCP) expression and mitochondrial function, as well as indices of calcium cycling (ryanodine 1 receptor: RyR1 and sarcoendoplasmic calcium-dependent ATPases SERCA1/ SERCA2a). Isoprenaline increased femoral artery blood flow, whereas phenylephrine reduced blood flow. At high doses only, isoprenaline treatment increased heat production in muscle. Phenylephrine treatment did not alter muscle temperature. Meal anticipation was evoked in fasted animals (previously program-fed) that were housed beside animals that were fed. Increases in muscle temperature were elicited by feeding and meal anticipation, without changes in blood flow during either paradigm. Analyses of respiration in isolated mitochondria indicated that the postprandial increase in heat production was associated with an increase in state 4 respiration, without increased UCP1, UCP2, or UCP3 expression. Feeding increased the expression of RyR1 and SERCA2a. We conclude that excursions in muscle temperature may occur independent of blood flow, suggesting that postprandial heat production is driven by altered mitochondrial function and changes in calcium cycling.

  5. Melatonin prevents abnormal mitochondrial dynamics resulting from the neurotoxicity of cadmium by blocking calcium-dependent translocation of Drp1 to the mitochondria.

    PubMed

    Xu, Shangcheng; Pi, Huifeng; Zhang, Lei; Zhang, Nixian; Li, YuMing; Zhang, Huiliang; Tang, Ju; Li, Huijuan; Feng, Min; Deng, Ping; Guo, Pan; Tian, Li; Xie, Jia; He, Mindi; Lu, Yonghui; Zhong, Min; Zhang, Yanwen; Wang, Wang; Reiter, Russel J; Yu, Zhengping; Zhou, Zhou

    2016-04-01

    Cadmium (Cd) is a persistent environmental toxin and occupational pollutant that is considered to be a potential risk factor in the development of neurodegenerative diseases. Abnormal mitochondrial dynamics are increasingly implicated in mitochondrial damage in various neurological pathologies. The aim of this study was to investigate whether the disturbance of mitochondrial dynamics contributed to Cd-induced neurotoxicity and whether melatonin has any neuroprotective properties. After cortical neurons were exposed to 10 μM cadmium chloride (CdCl2 ) for various periods (0, 3, 6, 12, and 24 hr), the morphology of their mitochondria significantly changed from the normal tubular networks into punctuated structures within 3 hr. Following this pronounced mitochondrial fragmentation, Cd treatment led to signs of mitochondrial dysfunction, including excess reactive oxygen species (ROS) production, decreased ATP content, and mitochondrial membrane potential (▵Ψm) loss. However, 1 mM melatonin pretreatment efficiently attenuated the Cd-induced mitochondrial fragmentation, which improved the turnover of mitochondrial function. In the brain tissues of rats that were intraperitoneally given 1 mg/kg CdCl2 for 7 days, melatonin also ameliorated excessive mitochondrial fragmentation and mitochondrial damage in vivo. Melatonin's protective effects were attributed to its roles in preventing cytosolic calcium ([Ca(2+) ]i ) overload, which blocked the recruitment of Drp1 from the cytoplasm to the mitochondria. Taken together, our results are the first to demonstrate that abnormal mitochondrial dynamics is involved in cadmium-induced neurotoxicity. Melatonin has significant pharmacological potential in protecting against the neurotoxicity of Cd by blocking the disbalance of mitochondrial fusion and fission.

  6. Aberrant calcium/calmodulin-dependent protein kinase II (CaMKII) activity is associated with abnormal dendritic spine morphology in the ATRX mutant mouse brain.

    PubMed

    Shioda, Norifumi; Beppu, Hideyuki; Fukuda, Takaichi; Li, En; Kitajima, Isao; Fukunaga, Kohji

    2011-01-05

    In humans, mutations in the gene encoding ATRX, a chromatin remodeling protein of the sucrose-nonfermenting 2 family, cause several mental retardation disorders, including α-thalassemia X-linked mental retardation syndrome. We generated ATRX mutant mice lacking exon 2 (ATRX(ΔE2) mice), a mutation that mimics exon 2 mutations seen in human patients and associated with milder forms of retardation. ATRX(ΔE2) mice exhibited abnormal dendritic spine formation in the medial prefrontal cortex (mPFC). Consistent with other mouse models of mental retardation, ATRX(ΔE2) mice exhibited longer and thinner dendritic spines compared with wild-type mice without changes in spine number. Interestingly, aberrant increased calcium/calmodulin-dependent protein kinase II (CaMKII) activity was observed in the mPFC of ATRX(ΔE2) mice. Increased CaMKII autophosphorylation and activity were associated with increased phosphorylation of the Rac1-guanine nucleotide exchange factors (GEFs) T-cell lymphoma invasion and metastasis 1 (Tiam1) and kalirin-7, known substrates of CaMKII. We confirmed increased phosphorylation of p21-activated kinases (PAKs) in mPFC extracts. Furthermore, reduced protein expression and activity of protein phosphatase 1 (PP1) was evident in the mPFC of ATRX(ΔE2) mice. In cultured cortical neurons, PP1 inhibition by okadaic acid increased CaMKII-dependent Tiam1 and kalirin-7 phosphorylation. Together, our data strongly suggest that aberrant CaMKII activation likely mediates abnormal spine formation in the mPFC. Such morphological changes plus elevated Rac1-GEF/PAK signaling seen in ATRX(ΔE2) mice may contribute to mental retardation syndromes seen in human patients.

  7. Overexpression of human mutated G93A SOD1 changes dynamics of the ER mitochondria calcium cycle specifically in mouse embryonic motor neurons.

    PubMed

    Lautenschläger, Janin; Prell, Tino; Ruhmer, Julia; Weidemann, Lisa; Witte, Otto W; Grosskreutz, Julian

    2013-09-01

    Motor neurons vulnerable to the rapidly progressive deadly neurodegenerative disease amyotrophic lateral sclerosis (ALS) inherently express low amounts of calcium binding proteins (CaBP), likely to allow physiological motor neuron firing frequency modulation. At the same time motor neurons are susceptible to AMPA receptor mediated excitotoxicity and internal calcium deregulation which is not fully understood. We analysed ER mitochondria calcium cycle (ERMCC) dynamics with subsecond resolution in G93A hSOD1 overexpressing motor neurons as a model of ALS using fluorescent calcium imaging. When comparing vulnerable motor neurons and non-motor neurons from G93A hSOD1 mice and their non-transgenic littermates, we found a decelerated cytosolic calcium clearance in the presence of G93A hSOD1. While both non-transgenic as well as G93A hSOD1 motor neurons displayed large mitochondrial calcium uptake by the mitochondrial uniporter (mUP), the mitochondrial calcium extrusion system was altered in the presence of G93A hSOD1. In addition, ER calcium uptake by the sarco-/endoplasmic reticulum ATPase (SERCA) was increased in G93A hSOD1 motor neurons. In survival assays, blocking the mitochondrial sodium calcium exchanger (mNCE) by CGP37157 as well as inhibiting SERCA by cyclopiazonic acid showed protective effects against kainate induced excitotoxicity. Thus, our study shows for the first time that the functional consequence of G93A hSOD1 overexpression in intact motor neurons is indeed a disturbance of the ER mitochondria calcium cycle, and identified two promising targets for therapeutic intervention in the pathology of ALS.

  8. Past daily light cycle recorded in the strontium/calcium ratios of giant clam shells.

    PubMed

    Sano, Yuji; Kobayashi, Sayumi; Shirai, Kotaro; Takahata, Naoto; Matsumoto, Katsumi; Watanabe, Tsuyoshi; Sowa, Kohki; Iwai, Kenji

    2012-03-27

    The historical record of daily light cycle in tropical and subtropical regions is short. Moreover, it remains difficult to extract this cycle in the past from natural archives such as biogenic marine carbonates. Here we describe the precise analysis of Sr/Ca, Mg/Ca, and Ba/Ca ratios in a cultivated giant clam shell, using a laterally high-resolution secondary ion mass spectrometer with 2 μm resolution. The Sr/Ca ratio exhibits striking diurnal variations, reflecting the daily light cycle. A clear seasonal variation in Sr/Ca is also observed in another longer set of measurements with 50 μm resolution. Light-enhanced calcification and elemental transportation processes, in giant clam and symbiotic algae, may explain these diurnal and annual variations. This opens the possibility to develop the Sr/Ca ratio from a giant clam shell as an effective proxy for parameters of the daily light cycle.

  9. Red blood cells of sickle cell disease patients exhibit abnormally high abundance of N-methyl D-aspartate receptors mediating excessive calcium uptake.

    PubMed

    Hänggi, Pascal; Makhro, Asya; Gassmann, Max; Schmugge, Markus; Goede, Jeroen S; Speer, Oliver; Bogdanova, Anna

    2014-10-01

    Recently we showed that N-methyl D-aspartate receptors (NMDARs) are expressed in erythroid precursors (EPCs) and present in the circulating red blood cells (RBCs) of healthy humans, regulating intracellular Ca(2+) in these cells. This study focuses on investigating the possible role of NMDARs in abnormally high Ca(2+) permeability in the RBCs of patients with sickle cell disease (SCD). Protein levels of the NMDAR subunits in the EPCs of SCD patients did not differ from those in EPCs of healthy humans. However, the number and activity of the NMDARs in circulating SCD-RBCs was substantially up-regulated, being particularly high during haemolytic crises. The number of active NMDARs correlated negatively with haematocrit and haemoglobin levels in the blood of SCD patients. Calcium uptake via these non-selective cation channels was induced by RBC treatment with glycine, glutamate and homocysteine and was facilitated by de-oxygenation of SCD-RBCs. Oxidative stress and RBC dehydration followed receptor stimulation and Ca(2+) uptake. Inhibition of the NMDARs with an antagonist memantine caused re-hydration and largely prevented hypoxia-induced sickling. The EPCs of SCD patients showed higher tolerance to memantine than those of healthy subjects. Consequently, NMDARs in the RBCs of SCD patients appear to be an attractive target for pharmacological intervention.

  10. Cell Cycle-Dependent Localization of Voltage-Dependent Calcium Channels and the Mitotic Apparatus in a Neuroendocrine Cell Line(AtT-20)

    PubMed Central

    Loechner, Karen J.; Salmon, Wendy C.; Fu, Jie; Patel, Shipra; McLaughlin, James T.

    2009-01-01

    Changes in intracellular calcium are necessary for the successful progression of mitosis in many cells. Both elevation and reduction in intracellular calcium can disrupt mitosis by mechanisms that remain ill defined. In this study we explore the role of transmembrane voltage-gated calcium channels (CaV channels) as regulators of mitosis in the mouse corticotroph cell line (AtT-20). We report that the nifedipine-sensitive isoform CaV1.2 is localized to the “poleward side” of kinetechores during metaphase and at the midbody during cytokinesis. A second nifedipine-sensitive isoform, CaV1.3, is present at the mid-spindle zone in telophase, but is also seen at the midbody. Nifedipine reduces the rate of cell proliferation, and, utilizing time-lapse microscopy, we show that this is due to a block at the prometaphase stage of the cell cycle. Using Fluo-4 we detect calcium fluxes at sites corresponding to the mid-spindle zone and the midbody region. Another calcium dye, Fura PE3/AM, causes an inhibition of mitosis prior to anaphase that we attribute to a chelation of intracellular calcium. Our results demonstrate a novel, isoform-specific localization of CaV1 channels during cell division and suggest a possible role for these channels in the calcium-dependent events underlying mitotic progression in pituitary corticotrophs. PMID:20130814

  11. Energetics, mechanics and molecular engineering of calcium cycling in skeletal muscle.

    PubMed

    Rall, Jack A

    2005-01-01

    During muscle contraction and relaxation, Ca2+ moves through a cycle. About 20 to 40% of the ATP utilized in a twitch or a tetanus is utilized by the SR Ca2+ pump to sequester Ca2+. Parvalbumin is a soluble Ca2+ binding protein that functions in parallel with the SR Ca2+ pump to promote relaxation in rapidly contracting and relaxing skeletal muscles, especially at low temperatures. The rate of Ca2+ dissociation from troponin C, once thought to be much more rapid than the rate of relaxation, is likely to be similar to the rate of cross-bridge detachment and to the rate of muscle relaxation under some conditions. During the past fifty years, great progress has been made in understanding the Ca2+ cycle during skeletal muscle contraction and relaxation. Nonetheless, there are still mysteries waiting to be unraveled.

  12. Menadione- (2-methyl-1,4-naphthoquinone-) dependent enzymatic redox cycling and calcium release by mitochondria.

    PubMed

    Frei, B; Winterhalter, K H; Richter, C

    1986-07-29

    The results presented in this paper reveal the existence of three distinct menadione (2-methyl-1,4-naphthoquinone) reductases in mitochondria: NAD(P)H:(quinone-acceptor) oxidoreductase (D,T-diaphorase), NADPH:(quinone-acceptor) oxidoreductase, and NADH:(quinone-acceptor) oxidoreductase. All three enzymes reduce menadione in a two-electron step directly to the hydroquinone form. NADH-ubiquinone oxidoreductase (NADH dehydrogenase) and NAD(P)H azoreductase do not participate significantly in menadione reduction. In mitochondrial extracts, the menadione-induced NAD(P)H oxidation occurs beyond stoichiometric reduction of the quinone and is accompanied by O2 consumption. Benzoquinone is reduced more rapidly than menadione but does not undergo redox cycling. In intact mitochondria, menadione triggers oxidation of intramitochondrial pyridine nucleotides, cyanide-insensitive O2 consumption, and a transient decrease of delta psi. In the presence of intramitochondrial Ca2+, the menadione-induced oxidation of pyridine nucleotides is accompanied by their hydrolysis, and Ca2+ is released from mitochondria. The menadione-induced Ca2+ release leaves mitochondria intact, provided excessive Ca2+ cycling is prevented. In both selenium-deficient and selenium-adequate mitochondria, menadione is equally effective in inducing oxidation of pyridine nucleotides and Ca2+ release. Thus, menadione-induced Ca2+ release is mediated predominantly by enzymatic two-electron reduction of menadione, and not by H2O2 generated by menadione-dependent redox cycling. Our findings argue against D,T-diaphorase being a control device that prevents quinone-dependent oxygen toxicity in mitochondria.

  13. Study of calcium-soy protein interactions by isothermal titration calorimetry and pH cycle.

    PubMed

    Canabady-Rochelle, Latha-Selvi; Sanchez, Christian; Mellema, Michel; Banon, Sylvie

    2009-07-08

    The aim of this work was to understand Ca-induced soy protein (nonhydrolyzed, NH; or hydrolyzed, H) aggregation and to characterize the involved interactions using ITC and pH cycle. The endothermic signals obtained upon titration of soy proteins with Ca were fitted with a one set of sites model. NH soy proteins bound more Ca than H soy proteins ( approximately 52 and approximately 2 mg of Ca/g of proteins, respectively). The binding constant K indicated the easier Ca binding onto H soy proteins than for NH soy proteins. The exothermic part involved by electrostatic interactions was completely hidden by the strong endothermic signal from the water molecule release. Ca binding onto soy proteins should be described as a H(+)/Ca(2+) exchange. Whatever the soy proteins, the positive value of heat capacity changes indicated a reduction in the number of surface-exposed polar residues. Ca-induced soy protein aggregation was irreversible for pH cycle to 3.5.

  14. Early development of intracellular calcium cycling defects in intact hearts of spontaneously hypertensive rats

    PubMed Central

    Kapur, Sunil; Aistrup, Gary L.; Sharma, Rohan; Kelly, James E.; Arora, Rishi; Zheng, Jiabo; Veramasuneni, Mitra; Kadish, Alan H.; Balke, C. William

    2010-01-01

    Defects in excitation-contraction coupling have been reported in failing hearts, but little is known about the relationship between these defects and the development of heart failure (HF). We compared the early changes in intracellular Ca2+ cycling to those that underlie overt pump dysfunction and arrhythmogenesis found later in HF. Laser-scanning confocal microscopy was used to measure Ca2+ transients in myocytes of intact hearts in Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) at different ages. Early compensatory mechanisms include a positive inotropic effect in SHRs at 7.5–9 mo compared with 6 mo. Ca2+ transient duration increased at 9 mo in SHRs, indicating changes in Ca2+ reuptake during decompensation. Cell-to-cell variability in Ca2+ transient duration increased at 7.5 mo, decreased at 9 mo, and increased again at 22 mo (overt HF), indicating extensive intercellular variability in Ca2+ transient kinetics during disease progression. Vulnerability to intercellular concordant Ca2+ alternans increased at 9–22 mo in SHRs and was mirrored by a slowing in Ca2+ transient restitution, suggesting that repolarization alternans and the resulting repolarization gradients might promote reentrant arrhythmias early in disease development. Intercellular discordant and subcellular Ca2+ alternans increased as early as 7.5 mo in SHRs and may also promote arrhythmias during the compensated phase. The incidence of spontaneous and triggered Ca2+ waves was increased in SHRs at all ages, suggesting a higher likelihood of triggered arrhythmias in SHRs compared with WKY rats well before HF develops. Thus serious and progressive defects in Ca2+ cycling develop in SHRs long before symptoms of HF occur. Defective Ca2+ cycling develops early and affects a small number of myocytes, and this number grows with age and causes the transition from asymptomatic to overt HF. These defects may also underlie the progressive susceptibility to Ca2+ alternans and Ca2+ wave

  15. Intermediate progenitors are increased by lengthening of the cell cycle through calcium signaling and p53 expression in human neural progenitors

    PubMed Central

    García-García, Elisa; Pino-Barrio, María José; López-Medina, Laura; Martínez-Serrano, Alberto

    2012-01-01

    During development, neurons can be generated directly from a multipotent progenitor or indirectly through an intermediate progenitor (IP). This last mode of division amplifies the progeny of neurons. The mechanisms governing the generation and behavior of IPs are not well understood. In this work, we demonstrate that the lengthening of the cell cycle enhances the generation of neurons in a human neural progenitor cell system in vitro and also the generation and expansion of IPs. These IPs are insulinoma-associated 1 (Insm1)+/BTG family member 2 (Btg2)−, which suggests an increase in a self-amplifying IP population. Later the cultures express neurogenin 2 (Ngn2) and become neurogenic. The signaling responsible for this cell cycle modulation is investigated. It is found that the release of calcium from the endoplasmic reticulum to the cytosol in response to B cell lymphoma-extra large overexpression or ATP addition lengths the cell cycle and increases the number of IPs and, in turn, the final neuron outcome. Moreover, data suggest that the p53–p21 pathway is responsible for the changes in cell cycle. In agreement with this, increased p53 levels are necessary for a calcium-induced increase in neurons. Our findings contribute to understand how calcium signaling can modulate cell cycle length during neurogenesis. PMID:22323293

  16. Methotrexate normalized keratinocyte activation cycle by overturning abnormal keratins as well as deregulated inflammatory mediators in psoriatic patients.

    PubMed

    Elango, Tamilselvi; Thirupathi, Anand; Subramanian, Swapna; Dayalan, Haripriya; Gnanaraj, Pushpa

    2015-12-07

    In psoriatic skin, epidermal keratinocytes undergo deregulated inflammatory response that leads to prolonged expression of inflammatory mediators as well as abnormal keratins. Methotrexate (MTX) is an immunosuppressive agent used as a standard drug to treat severe psoriasis. The aim of the study is to find the pharmacological effect of MTX on abnormal keratin and deregulated inflammatory mediators. Fifty-eight psoriasis vulgaris patients were recruited for this study. Skin biopsies of psoriatic patients were collected and analyzed for activation signal such as TNF-α and IFN-γ and deactivation signal such as TGF-β1. Also, protein and gene expression of normal keratins K14 and K10 and abnormal keratins K16 and K17 were analyzed in skin biopsies before (day 0) and after (at the end of 6 and 12 weeks) MTX treatment. Results show a significant decrease in tissue TNF-α and IFN-γ and increase in TGF-β1 after MTX treatment when compared with before MTX treatment in psoriasis patients (p<0.001). Protein and gene expression of K14, K16 and K17 decreased after MTX treatment, whereas the expression of differentiation marker K10 increased after MTX treatment. MTX resolves deregulated inflammatory markers and maintains normal keratin phenotype on hyperproliferating KC, thereby controlling acanthosis in psoriasis patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Calcium currents correlate with oocyte maturation during the reproductive cycle in Octopus vulgaris.

    PubMed

    Cuomo, Annunziata; Di Cristo, Carlo; Paolucci, Marina; Di Cosmo, Anna; Tosti, Elisabetta

    2005-03-01

    Using the whole-cell voltage clamp technique, we have studied the Ca2+ currents and the steady-state conductance during different oocyte growth stages and during the reproductive cycle of the female of Octopus vulgaris. Evidence is presented that L-type Ca2+ currents are high in small pre-vitellogenic oocytes (80-150 microm diameter) and significantly lower in early vitellogenic oocytes (180-300 microm diameter). Similarly, a significant decrease of the steady-state conductance occurred from the pre to early- vitellogenic oocytes. Octopus oocytes showed larger Ca2+ currents in the reproductive rather than non-reproductive periods. These data indicates that ion and L-type Ca2+ currents play a role in oocyte growth and cytoplasmic maturation, and possibly in preparing the plasma membrane to the interaction with the spermatozoon. By using fluorescent microscopy, we show that oocytes from 80 to 400 microm diameter have the large germinal vesicle characteristic of the immature oocytes. In subsequent stages of growth (up to 1000 microm diameter) the nucleus is no more visible and the metaphase spindle appears. These data demonstrate that Octopus vulgaris oocytes are arrested in the first meiotic prophase up to the early-vitellogenic stage and resume meiosis at this stage up to a second block presumably in metaphase I. We discuss a possible role for progesterone as the hormonal stimulus for the first prophase-metaphase meiotic transition.

  18. Intracellular calcium signals regulate growth of hepatic stellate cells via specific effects on cell cycle progression.

    PubMed

    Soliman, Elwy M; Rodrigues, Michele Angela; Gomes, Dawidson Assis; Sheung, Nina; Yu, Jin; Amaya, Maria Jimina; Nathanson, Michael H; Dranoff, Jonathan A

    2009-03-01

    Hepatic stellate cells (HSC) are important mediators of liver fibrosis. Hormones linked to downstream intracellular Ca(2+) signals upregulate HSC proliferation, but the mechanisms by which this occurs are unknown. Nuclear and cytosolic Ca(2+) signals may have distinct effects on cell proliferation, so we expressed plasmid and adenoviral constructs containing the Ca(2+) chelator parvalbumin (PV) linked to either a nuclear localization sequence (NLS) or a nuclear export sequence (NES) to block Ca(2+) signals in distinct compartments within LX-2 immortalized human HSC and primary rat HSC. PV-NLS and PV-NES constructs each targeted to the appropriate intracellular compartment and blocked Ca(2+) signals only within that compartment. PV-NLS and PV-NES constructs inhibited HSC growth. Furthermore, blockade of nuclear or cytosolic Ca(2+) signals arrested growth at the G2/mitosis (G2/M) cell-cycle interface and prevented the onset of mitosis. Blockade of nuclear or cytosolic Ca(2+) signals downregulated phosphorylation of the G2/M checkpoint phosphatase Cdc25C. Inhibition of calmodulin kinase II (CaMK II) had identical effects on LX-2 growth and Cdc25C phosphorylation. We propose that nuclear and cytosolic Ca(2+) are critical signals that regulate HSC growth at the G2/M checkpoint via CaMK II-mediated regulation of Cdc25C phosphorylation. These data provide a new logical target for pharmacological therapy directed against progression of liver fibrosis.

  19. Association of Electrocardiographic Abnormalities with Coronary Artery Calcium and Carotid Artery Intima-Media Thickness in Individuals without Clinical Coronary Heart Disease (From the Multi-Ethnic Study of Atherosclerosis [MESA])

    PubMed Central

    Lloyd-Jones, Donald M.; Walsh, Joseph A; Prineas, Ronald J.; Ning, Hongyan; Liu, Kiang; Daviglus, Martha L.; Shea, Steven; Detrano, Robert C.; Tandri, Harikrishna; Greenland, Philip

    2010-01-01

    Isolated minor non-specific ST-segment and T-wave (NSSTA), minor and major electrocardiographic (ECG) abnormalities are established, independent risk markers for incident cardiovascular events. Their association with subclinical atherosclerosis has been postulated but is not clearly defined. The aim of this study is to define the association between ECG abnormalities and measures of subclinical atherosclerosis. We studied participants from MESA, a multi-ethnic sample of men and women aged 45–84 and free of clinical cardiovascular disease at enrollment. Baseline examination included measurement of traditional risk factors, resting 12-lead electrocardiograms, coronary artery calcium (CAC) measurement and common carotid intima-media thickness (CCIMT). Electrocardiograms were coded using Novacode criteria and were defined as having either minor abnormalities (e.g., minor non-specific STTA, first degree atrioventricular block, and QRS axis deviations) or major abnormalities (e.g., pathologic Q waves, major ST-segment and T-wave abnormalities, significant dysrhythmias and conduction system delays). Multivariable logistic and linear regressions were used to determine the cross-sectional associations of ECG abnormalities with CAC and common carotid-IMT. Among 6710 participants, 52.7% were women, with a mean age of 62 years. After multivariable-adjustment, isolated minor STTA, minor and major ECG abnormalities were not associated with the presence of CAC (>0) among men (OR 1.04, 95% CI 0.81–1.33; 1.10, 0.91–1.32; and 1.03, 0.81–1.31, respectively) or women (1.01, 0.82–1.24; 1.04, 0.87–1.23; and 0.94, 0.73–1.22, respectively). Lack of association remained consistent when using both log CAC and CC-IMT as continuous variables. ECG abnormalities are not associated with markers of subclinical atherosclerosis in a large multi-ethnic cohort. PMID:19801030

  20. Association of electrocardiographic abnormalities with coronary artery calcium and carotid artery intima-media thickness in individuals without clinical coronary heart disease (from the Multi-Ethnic Study of Atherosclerosis [MESA]).

    PubMed

    Lloyd-Jones, Donald M; Walsh, Joseph A; Prineas, Ronald J; Ning, Hongyan; Liu, Kiang; Daviglus, Martha L; Shea, Steven; Detrano, Robert C; Tandri, Harikrishna; Greenland, Philip

    2009-10-15

    Isolated minor nonspecific ST-segment and T-wave abnormalities (NSSTAs), minor and major electrocardiographic (ECG) abnormalities are established, independent risk markers for incident cardiovascular events. Their association with subclinical atherosclerosis has been postulated but is not clearly defined. The aim of this study was to define the association between ECG abnormalities and measurements of subclinical atherosclerosis. We studied participants from MESA, a multiethnic sample of men and women 45 to 84 years of age and free of clinical cardiovascular disease at enrollment. Baseline examination included measurement of traditional risk factors, 12-lead electrocardiograms at rest, coronary artery calcium (CAC) measurement, and common carotid intima-media thickness (CC-IMT). Electrocardiograms were coded using Novacode criteria and were defined as having minor abnormalities (e.g., minor NSSTTAs, first-degree atrioventricular block, and QRS-axis deviations) or major abnormalities (e.g., pathologic Q waves, major STTAs, significant dysrhythmias, and conduction system delays). Multivariable logistic and linear regressions were used to determine cross-sectional associations of ECG abnormalities with CAC and CC-IMT. Of 6,710 participants, 52.7% were women, with a mean age of 62 years. After multivariable adjustment, isolated minor STTAs and minor and major ECG abnormalities were not associated with presence of CAC (>0) in men (odds ratio 1.04, 95% confidence interval 0.81 to 1.33; 1.10, 0.91 to 1.32; and 1.03, 0.81 to 1.31, respectively) or women (1.01, 0.82 to 1.24; 1.04, 0.87 to 1.23; and 0.94, 0.73 to 1.22, respectively). Lack of association remained consistent when using log CAC and CC-IMT as continuous variables. In conclusion, ECG abnormalities are not associated with markers of subclinical atherosclerosis in a large multiethnic cohort.

  1. Manganese effectively supports yeast cell-cycle progression in place of calcium

    PubMed Central

    1995-01-01

    Metal ion requirements for the proliferation of Saccharomyces cerevisiae were investigated. We used bis-(o-aminophenoxy)-ethane- N,N,N',N'-tetraacetic acid (BAPTA), a relatively acid tolerant chelator, to reduce the free metal ion concentrations in culture media. Chelatable metal ions were added back individually and in combination. In addition to a requirement for approximately 10 pM external free Zn2+ we found an interchangeable requirement for either 66 nM free Ca2+ or only 130 pM free Mn2+. Cells depleted of Mn2+ and Ca2+ arrested as viable cells with 2 N nuclei and tended to have very small minibuds. In the absence of added Mn2+, robust growth required approximately 60 microM total internal Ca2+. In the presence of added Mn2+, robust growth continued even when internal Ca2+ was < 3% this level. Chelator- free experiments showed that MnCl2 strongly and CaCl2 weakly restored high-temperature growth of cdc1ts strains which similarly arrest as viable cells with 2 N nuclear contents and small buds. Its much greater effectiveness compared with Ca2+ suggests that Mn2+ is likely to be a physiologic mediator of bud and nuclear development in yeast. This stands in marked contrast to a claim that Ca2+ is uniquely required for cell-cycle progression in yeast. We discuss the possibility that Mn2+ may function as an intracellular signal transducer and how this possibility relates to previous claims of Ca2+'s roles in yeast metabolism. PMID:7490280

  2. Stage-specific changes in calcium concentration in crustacean (Callinectes sapidus) Y-organs during a natural molting cycle, and their relation to the hemolymphatic ecdysteroid titer.

    PubMed

    Chen, Hsiang-Yin; Dillaman, Richard M; Roer, Robert D; Watson, R Douglas

    2012-09-01

    Secretion of ecdysteroid molting hormones by crustacean Y-organs is suppressed by molt-inhibiting hormone (MIH). The suppressive effect of MIH on ecdysteroidogenesis is mediated by one or more cyclic nucleotide second messengers. In addition, existing data indicate that ecdysteroidogenesis is positively regulated (stimulated) by intracellular Ca(++). Despite the apparent critical role of calcium in regulating ecdysteroidogenesis, the level of Ca(++) in Y-organ cells has not been previously measured during a natural molting cycle for any crustacean species. In studies reported here, a fluorescent calcium indicator (Fluo-4) was used to measure Ca(++) levels in Y-organs during a molting cycle of the blue crab, Callinectes sapidus. Mean calcium fluorescence increased 5.8-fold between intermolt (C4) and stage D3 of premolt, and then dropped abruptly, reaching a level in postmolt (A) that was not significantly different from that in intermolt (P>0.05). The level of ecdysteroids in hemolymph of Y-organ donor crabs (measured by radioimmunoassay) showed an overall pattern similar to that observed for calcium fluorescence, rising from 2.9 ng/mL in intermolt to 357.1 ng/mL in D3 (P<0.05), and then dropping to 55.3 ng/mL in D4 (P<0.05). The combined results are consistent with the hypothesis that ecdysteroidogenesis is stimulated by an increase in intracellular Ca(++). Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Novel Metabolic Abnormalities in the Tricarboxylic Acid Cycle in Peripheral Cells From Huntington’s Disease Patients

    PubMed Central

    Naseri, Nima N.; Bonica, Joseph; Xu, Hui; Park, Larry C.; Arjomand, Jamshid; Chen, Zhengming; Gibson, Gary E.

    2016-01-01

    Metabolic dysfunction is well-documented in Huntington’s disease (HD). However, the link between the mutant huntingtin (mHTT) gene and the pathology is unknown. The tricarboxylic acid (TCA) cycle is the main metabolic pathway for the production of NADH for conversion to ATP via the electron transport chain (ETC). The objective of this study was to test for differences in enzyme activities, mRNAs and protein levels related to the TCA cycle between lymphoblasts from healthy subjects and from patients with HD. The experiments utilize the advantages of lymphoblasts to reveal new insights about HD. The large quantity of homogeneous cell populations permits multiple dynamic measures to be made on exactly comparable tissues. The activities of nine enzymes related to the TCA cycle and the expression of twenty-nine mRNAs encoding for these enzymes and enzyme complexes were measured. Cells were studied under baseline conditions and during metabolic stress. The results support our recent findings that the activities of the pyruvate dehydrogenase complex (PDHC) and succinate dehydrogenase (SDH) are elevated in HD. The data also show a large unexpected depression in MDH activities. Furthermore, message levels for isocitrate dehydrogenase 1 (IDH1) were markedly increased in in HD lymphoblasts and were responsive to treatments. The use of lymphoblasts allowed us to clarify that the reported decrease in aconitase activity in HD autopsy brains is likely due to secondary hypoxic effects. These results demonstrate the mRNA and enzymes of the TCA cycle are critical therapeutic targets that have been understudied in HD. PMID:27611087

  4. Metabolism of 25-hydroxyvitamin D3 in renal slices from the X-linked hypophosphatemic (Hyp) mouse: abnormal response to fall in serum calcium.

    PubMed

    Tenenhouse, H S

    1984-02-01

    The effect of the X-linked Hyp mutation on 25-hydroxyvitamin D3 (25-OH-D3) metabolism in mouse renal cortical slices was investigated. Vitamin D replete normal mice and Hyp littermates fed the control diet synthesized primarily 24,25-dihydroxyvitamin D3 (24,25-(OH)2D3); only minimal synthesis of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) was detected in both genotypes and 1,25-(OH)2D3 formation was not significantly greater in Hyp mice relative to normal littermates, despite hypophosphatemia and hypocalcemia in the mutants. Calcium-deficient diet fed to normal mice reduced serum calcium (p less than 0.01), increased renal 25-hydroxyvitamin D3-1-hydroxylase (1-OHase) activity (p less than 0.05), and decreased 25-hydroxyvitamin D3-24-hydroxylase (24-OHase) activity (p less than 0.05). In contrast, Hyp littermates on the calcium-deficient diet had decreased serum calcium (p less than 0.01), without significant changes in the renal metabolism of 25-OH-D3. Both normal and Hyp mice responded to the vitamin D-deficient diet with a fall in serum calcium (p less than 0.01), significantly increased renal 1-OHase, and significantly decreased renal 24-OHase activities. In Hyp mice, the fall in serum calcium on the vitamin D-deficient diet was significantly greater than that observed on the calcium-deficient diet. Therefore the ability of Hyp mice to increase renal 1-OHase activity when fed the vitamin D-deficient diet and their failure to do so on the calcium-deficient diet may be related to the resulting degree of hypocalcemia. The results suggest that although Hyp mice can respond to a disturbance of calcium homeostasis, the in vivo signal for the stimulation of renal 1-OHase activity may be set at a different threshold in the Hyp mouse; i.e. a lower serum calcium concentration is necessary for Hyp mice to initiate increased synthesis of 1,25(-OH)2D3.

  5. Methylphenidate treatment leads to abnormalities on krebs cycle enzymes in the brain of young and adult rats.

    PubMed

    Réus, Gislaine Z; Scaini, Giselli; Furlanetto, Camila B; Morais, Meline O S; Jeremias, Isabela C; Mello-Santos, Lis Mairá; Freitas, Karolina V; Quevedo, João; Streck, Emilio L

    2013-08-01

    Studies have shown a relationship between energy metabolism and methylphenidate (MPH); however, there are no studies evaluating the effects of MPH in Krebs cycle. So, we investigated if MPH treatment could alter the activity of citrate synthase (CS), malate dehydrogenase (MD), and isocitrate dehydrogenase (ID) in the brain of young and adult Wistar rats. Our results showed that MPH (2 and 10 mg/kg) reduced CS in the striatum and prefrontal cortex (PF), with MPH at all doses in the cerebellum and hippocampus after chronic treatment in young rats. In adult rats the CS was reduced in the cerebellum after acute treatment with MPH at all doses, and after chronic treatment in the PF and cerebellum with MPH (10 mg/kg), and in the hippocampus with MPH (2 and 10 mg/kg). The ID decreased in the hippocampus and striatum with MPH (2 and 10 mg/kg), and in the cortex (10 mg/kg) after acute treatment in young rats. In adult rats acute treatment with MPH (2 and 10 mg/kg) reduced ID in the cerebellum, and with MPH (10 mg/kg) in the cortex; chronic treatment with MPH (10 mg/kg) decreased ID in the PF; with MPH (2 and 10 mg/kg) in the cerebellum, and with MPH at all doses in the hippocampus. The MD did not alter. In conclusion, our results suggest that MPH can alter enzymes of Krebs cycle in brain areas involved with circuits related with attention deficit hyperactivity disorder; however, such effects depend on age of animal and treatment regime.

  6. Abnormal crystal growth in CH3NH3PbI3-xClx using a multi-cycle solution coating process

    DOE PAGES

    Dong, Qingfeng; Yuan, Yongbo; Shao, Yuchuan; ...

    2015-06-23

    Recently, the efficiency of organolead trihalide perovskite solar cells has improved greatly because of improved material qualities with longer carrier diffusion lengths. Mixing chlorine in the precursor for mixed halide films has been reported to dramatically enhance the diffusion lengths of mixed halide perovskite films, mainly as a result of a much longer carrier recombination lifetime. Here we report that adding Cl containing precursor for mixed halide perovskite formation can induce the abnormal grain growth behavior that yields well-oriented grains accompanied by the appearance of some very large size grains. The abnormal grain growth becomes prominent only after multi-cycle coatingmore » of MAI : MACl blend precursor. The large grain size is found mainly to contribute to a longer carrier charge recombination lifetime, and thus increases the device efficiency to 18.9%, but without significantly impacting the carrier transport property. As a result, the strong correlation identified between material process and morphology provides guidelines for future material optimization and device efficiency enhancement.« less

  7. Poly(ADP-ribosyl)ation enhances H-RAS protein stability and causes abnormal cell cycle progression in human TK6 lymphoblastoid cells treated with hydroquinone.

    PubMed

    Liu, Linhua; Ling, Xiaoxuan; Tang, Huanwen; Chen, Jialong; Wen, Qiaosheng; Zou, Fei

    2015-08-05

    Hydroquinone (HQ), one of the most important benzene-derived metabolites, can induce aberrant cell cycle progression; however, the mechanism of this induction remains unclear. Poly(ADP-ribosyl)ation (PARylation), which is catalysed primarily by poly(ADP-ribose) polymerase-1 (PARP-1), participates in various biological processes, including cell cycle control. The results of the present study show an accumulation in G1 phase versus S phase of TK6 human lymphoblast cells treated with HQ for 48h compared with PBS-treated cells; after 72h of HQ treatment, the cells transitioned from G1 arrest to S phase arrest. We examined the expression of six genes related to the cell cycle or leukaemia to further explore the reason for this phenomenon. Among these genes, H-RAS was found to be associated with this phenomenon because its mRNA and protein expression decreased at 48h and increased at 72h. Experiments for PARP activity induction and inhibition revealed that the observed PARylation was positively associated with H-RAS expression. Moreover, in cells treated with HQ in conjunction with PARP-1 knockdown, expression of the H-RAS protein decreased and the number of cells in G1 phase increased. The degree of poly(ADP-ribosyl) modification of the H-RAS protein increased in cells treated with HQ for 72h, further supporting that changes in PARylation contributed to the rapid alteration of H-RAS protein expression, followed by abnormal progression of the cell cycle. Co-immunoprecipitation (co-IP) assays were employed to determine whether protein complexes were formed by PARP-1 and H-RAS proteins, and the direct interaction between these proteins indicated that PARylation regulated H-RAS expression. As detected by confocal microscopy, the H-RAS protein was found in the nucleus and cytoplasm. To our knowledge, this study is the first to reveal that H-RAS protein can be modified by PARylation.

  8. Chronic agomelatine treatment corrects the abnormalities in the circadian rhythm of motor activity and sleep/wake cycle induced by prenatal restraint stress in adult rats.

    PubMed

    Mairesse, Jerome; Silletti, Viviana; Laloux, Charlotte; Zuena, Anna Rita; Giovine, Angela; Consolazione, Michol; van Camp, Gilles; Malagodi, Marithe; Gaetani, Silvana; Cianci, Silvia; Catalani, Assia; Mennuni, Gioacchino; Mazzetta, Alessandro; van Reeth, Olivier; Gabriel, Cecilia; Mocaër, Elisabeth; Nicoletti, Ferdinando; Morley-Fletcher, Sara; Maccari, Stefania

    2013-03-01

    Agomelatine is a novel antidepressant acting as an MT1/MT2 melatonin receptor agonist/5-HT2C serotonin receptor antagonist. Because of its peculiar pharmacological profile, this drug caters the potential to correct the abnormalities of circadian rhythms associated with mood disorders, including abnormalities of the sleep/wake cycle. Here, we examined the effect of chronic agomelatine treatment on sleep architecture and circadian rhythms of motor activity using the rat model of prenatal restraint stress (PRS) as a putative 'aetiological' model of depression. PRS was delivered to the mothers during the last 10 d of pregnancy. The adult progeny ('PRS rats') showed a reduced duration of slow wave sleep, an increased duration of rapid eye movement (REM) sleep, an increased number of REM sleep events and an increase in motor activity before the beginning of the dark phase of the light/dark cycle. In addition, adult PRS rats showed an increased expression of the transcript of the primary response gene, c-Fos, in the hippocampus just prior to the beginning of the dark phase. All these changes were reversed by a chronic oral treatment with agomelatine (2000 ppm in the diet). The effect of agomelatine on sleep was largely attenuated by treatment with the MT1/MT2 melatonin receptor antagonist, S22153, which caused PRS-like sleep disturbances on its own. These data provide the first evidence that agomelatine corrects sleep architecture and restores circadian homeostasis in a preclinical model of depression and supports the value of agomelatine as a novel antidepressant that resynchronizes circadian rhythms under pathological conditions.

  9. Bone mass changes in vivo during the entire reproductive cycle in rats feeding different dietary calcium and calcium/phosphorus ratio content.

    PubMed

    Zeni, S; Weisstaub, A; Di Gregorio, S; Ronanre De Ferrer, P; Portela, M L de

    2003-12-01

    The purpose of this study was to quantify in vivo the impact of different dietary Ca contents on the maternal total skeleton and skeletal sub-areas in adult rats during pregnancy and lactation, using DXA. Twenty-four female Wistar rats (approximately 5 months old) were mated and divided into three groups (n = 8) and fed one of the following diets, varying only in Ca content (LCD: 0.14%, NCD: 0.6% or HCD: 1.2%). Pups were adjusted to 8-9 per dam. Maternal ionic calcium and in vivo bone mineral density (BMD) were measured at the beginning, after delivery and after weaning. Regardless of the diet, ionized calcium decreased from onset to weaning ( P < 0.05). At weaning, bone mass decreased 7.3% in NCD, 15% in LCD and 10.5% in HCD from initial values. Total skeleton, whole and proximal tibia and spine BMDs only decreased at delivery in the LCD group ( P < 0.05) but, irrespective of the diet, at weaning, they were lower compared to delivery and initial values ( P < 0.05). LCD group presented the lowest BMD in the proximal tibia and spine regions ( P < 0.05). At birth, pups did not present differences, however, at weaning, LCD pups reached the lowest body weight ( P < 0.05), NCD presented the highest body Ca content ( P < 0.05) and there were no differences between LCD and HCD. This in vivo study showed that regardless of the dietary calcium content, the maternal skeleton is slightly affected by pregnancy but severely affected by lactation. However, the degree of such response appears to depend not only on dietary Ca content but also on dietary Ca/P molar ratio.

  10. Correction of the abnormal mineral ion homeostasis with a high-calcium, high-phosphorus, high-lactose diet rescues the PDDR phenotype of mice deficient for the 25-hydroxyvitamin D-1alpha-hydroxylase (CYP27B1).

    PubMed

    Dardenne, O; Prud'homme, J; Hacking, S A; Glorieux, F H; St-Arnaud, R

    2003-04-01

    Mutations in the 25-hydroxyvitamin D-1alpha-hydroxylase gene (CYP27B1; 1alpha-OHase) cause pseudo vitamin D deficiency rickets (PDDR), while mutations in the vitamin D receptor (VDR) cause hereditary vitamin D resistance rickets. Animal models of both diseases have been engineered. The bone phenotype of VDR-ablated mice can be completely rescued by feeding the animals with a high-calcium, high-phosphorus, high-lactose diet. We have attempted to rescue the PDDR phenotype of mice deficient for the 1alpha-OHase gene by feeding them with the high-calcium diet. The rescue regimen consisted of feeding a diet containing 2% calcium, 1.25% phosphorus, 20% lactose (rescue diet) from 3 weeks of age until sacrifice at 8.5 weeks of age. Blood biochemistry analysis revealed that the rescue diet corrected the hypocalcemia and secondary hyperparathyroidism. Despite the restoration of normocalcemia, 1alpha-OHase(-/-) (and 1alpha-OHase(+/-)) animals fed the rescue diet initially gained weight less rapidly than control mice fed normal mouse chow. Although 1alpha-OHase(-/-) mice fed the rescue diet eventually reached the same weight as control animals, the treatment did not entirely correct bone growth, as femur size remained significantly smaller than that of control. Bone histology and histomorphometry confirmed that the rickets and osteomalacia were cured. The rescue diet also restored the biomechanical properties of the bone tissue within normal parameters. These results demonstrate that correction of the abnormal mineral ion homeostasis by feeding with a high-calcium rescue diet is effective to rescue the PDDR phenotype of 1alpha-OHase mutant mice. This treatment, however, does not appear as effective as 1,25(OH)(2)D(3) replacement therapy since bone growth remained impaired.

  11. Calsequestrin 2 deletion causes sinoatrial node dysfunction and atrial arrhythmias associated with altered sarcoplasmic reticulum calcium cycling and degenerative fibrosis within the mouse atrial pacemaker complex1

    PubMed Central

    Glukhov, Alexey V.; Kalyanasundaram, Anuradha; Lou, Qing; Hage, Lori T.; Hansen, Brian J.; Belevych, Andriy E.; Mohler, Peter J.; Knollmann, Björn C.; Periasamy, Muthu; Györke, Sandor; Fedorov, Vadim V.

    2015-01-01

    Aims Loss-of-function mutations in Calsequestrin 2 (CASQ2) are associated with catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT patients also exhibit bradycardia and atrial arrhythmias for which the underlying mechanism remains unknown. We aimed to study the sinoatrial node (SAN) dysfunction due to loss of CASQ2. Methods and results In vivo electrocardiogram (ECG) monitoring, in vitro high-resolution optical mapping, confocal imaging of intracellular Ca2+ cycling, and 3D atrial immunohistology were performed in wild-type (WT) and Casq2 null (Casq2−/−) mice. Casq2−/− mice exhibited bradycardia, SAN conduction abnormalities, and beat-to-beat heart rate variability due to enhanced atrial ectopic activity both at baseline and with autonomic stimulation. Loss of CASQ2 increased fibrosis within the pacemaker complex, depressed primary SAN activity, and conduction, but enhanced atrial ectopic activity and atrial fibrillation (AF) associated with macro- and micro-reentry during autonomic stimulation. In SAN myocytes, CASQ2 deficiency induced perturbations in intracellular Ca2+ cycling, including abnormal Ca2+ release, periods of significantly elevated diastolic Ca2+ levels leading to pauses and unstable pacemaker rate. Importantly, Ca2+ cycling dysfunction occurred not only at the SAN cellular level but was also globally manifested as an increased delay between action potential (AP) and Ca2+ transient upstrokes throughout the atrial pacemaker complex. Conclusions Loss of CASQ2 causes abnormal sarcoplasmic reticulum Ca2+ release and selective interstitial fibrosis in the atrial pacemaker complex, which disrupt SAN pacemaking but enhance latent pacemaker activity, create conduction abnormalities and increase susceptibility to AF. These functional and extensive structural alterations could contribute to SAN dysfunction as well as AF in CPVT patients. PMID:24216388

  12. Abnormal Calcium Levels During Trauma Resuscitation Are Associated With Increased Mortality, Increased Blood Product Use, and Greater Hospital Resource Consumption: A Pilot Investigation.

    PubMed

    MacKay, Emily J; Stubna, Michael D; Holena, Daniel N; Reilly, Patrick M; Seamon, Mark J; Smith, Brian P; Kaplan, Lewis J; Cannon, Jeremy W

    2017-09-01

    Admission hypocalcemia predicts both massive transfusion and mortality in severely injured patients. However, the effect of calcium derangements during resuscitation remains unexplored. We hypothesize that any hypocalcemia or hypercalcemia (either primary or from overcorrection) in the first 24 hours after severe injury is associated with increased mortality. All patients at our institution with massive transfusion protocol activation from January 2013 through December 2014 were identified. Patients transferred from another hospital, those not transfused, those with no ionized calcium (Ca) measured, and those who expired in the trauma bay were excluded. Hypocalcemia and hypercalcemia were defined as any level outside the normal range of Ca at our institution (1-1.25 mmol/L). Receiver operator curve analysis was also used to further examine significant thresholds for both hypocalcemia and hypercalcemia. Hospital mortality was compared between groups. Secondary outcomes included advanced cardiovascular life support, damage control surgery, ventilator days, and intensive care unit days. The massive transfusion protocol was activated for 77 patients of whom 36 were excluded leaving 41 for analysis. Hypocalcemia occurred in 35 (85%) patients and hypercalcemia occurred in 9 (22%). Mortality was no different in hypocalcemia versus no hypocalcemia (29% vs 0%; P = .13) but was greater in hypercalcemia versus no hypercalcemia (78% vs 9%; P < .01). Receiver operator curve analysis identified inflection points in mortality outside a Ca range of 0.84 to 1.30 mmol/L. Using these extreme values, 15 (37%) had hypocalcemia with a 60% mortality (vs 4%; P < .01) and 9 (22%) had hypercalcemia with a 78% mortality (vs 9%; P < .01). Patients with extreme hypocalcemia and hypercalcemia also received more red blood cells, plasma, platelets, and calcium repletion. Hypocalcemia and hypercalcemia occur commonly during the initial resuscitation of severely injured patients. Mild hypocalcemia

  13. Abnormality in glutamine–glutamate cycle in the cerebrospinal fluid of cognitively intact elderly individuals with major depressive disorder: a 3-year follow-up study

    PubMed Central

    Hashimoto, K; Bruno, D; Nierenberg, J; Marmar, C R; Zetterberg, H; Blennow, K; Pomara, N

    2016-01-01

    Major depressive disorder (MDD), common in the elderly, is a risk factor for dementia. Abnormalities in glutamatergic neurotransmission via the N-methyl-d-aspartate receptor (NMDA-R) have a key role in the pathophysiology of depression. This study examined whether depression was associated with cerebrospinal fluid (CSF) levels of NMDA-R neurotransmission-associated amino acids in cognitively intact elderly individuals with MDD and age- and gender-matched healthy controls. CSF was obtained from 47 volunteers (MDD group, N=28; age- and gender-matched comparison group, N=19) at baseline and 3-year follow-up (MDD group, N=19; comparison group, N=17). CSF levels of glutamine, glutamate, glycine, l-serine and d-serine were measured by high-performance liquid chromatography. CSF levels of amino acids did not differ across MDD and comparison groups. However, the ratio of glutamine to glutamate was significantly higher at baseline in subjects with MDD than in controls. The ratio decreased in individuals with MDD over the 3-year follow-up, and this decrease correlated with a decrease in the severity of depression. No correlations between absolute amino-acid levels and clinical variables were observed, nor were correlations between amino acids and other biomarkers (for example, amyloid-β42, amyloid-β40, and total and phosphorylated tau protein) detected. These results suggest that abnormalities in the glutamine–glutamate cycle in the communication between glia and neurons may have a role in the pathophysiology of depression in the elderly. Furthermore, the glutamine/glutamate ratio in CSF may be a state biomarker for depression. PMID:26926880

  14. Abnormal amounts of intracellular calcium regulatory proteins in SHRSP.Z-Lepr(fa)/IzmDmcr rats with metabolic syndrome and cardiac dysfunction.

    PubMed

    Kagota, Satomi; Maruyama, Kana; Tada, Yukari; Wakuda, Hirokazu; Nakamura, Kazuki; Kunitomo, Masaru; Shinozuka, Kazumasa

    2013-02-01

    Metabolic syndrome is known to increase the risk of abnormal cardiac structure and function, which are considered to contribute to increased incidence of cardiovascular disease and mortality. We previously demonstrated that ventricular hypertrophy and diastolic dysfunction occur in SHRSP.Z-Lepr(fa)/IzmDmcr (SHRSP fatty) rats with metabolic syndrome. The aim of this study was to investigate the possible mechanisms underlying abnormal heart function in SHRSP fatty rats. The amount of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) 2a, phospholamban (PLB) protein, and Ser(16)-phosphorylated PLB was decreased in cardiomyocytes from SHRSP fatty rats compared with those from control Wistar-Kyoto rats at 18 weeks of age, and the PLB-to-SERCA2a ratio was increased. Left ventricular developed pressure was unchanged, and coronary flow rate and maximum rate of left ventricular pressure decline (-dP/dt) was decreased in SHRSP fatty rats. Treatment with telmisartan reversed the abnormalities of PLB amount, coronary flow rate, and -dP/dt in SHRSP fatty rats. These results indicate that abnormal amounts of intracellular Ca(2+) regulatory proteins in cardiomyocytes, leading to reduced intracellular Ca(2+) reuptake into the sarcoplasmic reticulum, may play a role in the diastolic dysfunction in SHRSP fatty rats and that these effects are partially related to decreased coronary circulation. Telmisartan may be beneficial in protecting against disturbances in cardiac function associated with metabolic syndrome.

  15. Calcium and Arrhythmogenesis

    PubMed Central

    Ter Keurs, Henk E. D. J.; Boyden, Penelope A.

    2010-01-01

    Triggered activity in cardiac muscle and intracellular Ca2+ have been linked in the past. However, today not only are there a number of cellular proteins that show clear Ca2+ dependence but also there are a number of arrhythmias whose mechanism appears to be linked to Ca2+-dependent processes. Thus we present a systematic review of the mechanisms of Ca2+ transport (forward excitation-contraction coupling) in the ventricular cell as well as what is known for other cardiac cell types. Second, we review the molecular nature of the proteins that are involved in this process as well as the functional consequences of both normal and abnormal Ca2+ cycling (e.g., Ca2+ waves). Finally, we review what we understand to be the role of Ca2+ cycling in various forms of arrhythmias, that is, those associated with inherited mutations and those that are acquired and resulting from reentrant excitation and/or abnormal impulse generation (e.g., triggered activity). Further solving the nature of these intricate and dynamic interactions promises to be an important area of research for a better recognition and understanding of the nature of Ca2+ and arrhythmias. Our solutions will provide a more complete understanding of the molecular basis for the targeted control of cellular calcium in the treatment and prevention of such. PMID:17429038

  16. Absence of the Regulator of G-protein Signaling, RGS4, Predisposes to Atrial Fibrillation and Is Associated with Abnormal Calcium Handling*

    PubMed Central

    Opel, Aaisha; Nobles, Muriel; Montaigne, David; Finlay, Malcolm; Anderson, Naomi; Breckenridge, Ross; Tinker, Andrew

    2015-01-01

    The description of potential molecular substrates for predisposition to atrial fibrillation (AF) is incomplete, and it is unknown what role regulators of G-protein signaling might play. We address whether the attenuation of RGS4 function may promote AF and the mechanism through which this occurs. For this purpose, we studied a mouse with global genetic deletion of RGS4 (RGS4−/−) and the normal littermate controls (RGS4+/+). In vivo electrophysiology using atrial burst pacing revealed that mice with global RGS4 deletion developed AF more frequently than control littermates. Isolated atrial cells from RGS4−/− mice show an increase in Ca2+ spark frequency under basal conditions and after the addition of endothelin-1 and abnormal spontaneous Ca2+ release events after field stimulation. Isolated left atria studied on a multielectrode array revealed modest changes in path length for re-entry but abnormal electrical events after a pacing train in RGS4−/− mice. RGS4 deletion results in a predisposition to atrial fibrillation from enhanced activity in the Gαq/11-IP3 pathway, resulting in abnormal Ca2+ release and corresponding electrical events. PMID:26088132

  17. Absence of the Regulator of G-protein Signaling, RGS4, Predisposes to Atrial Fibrillation and Is Associated with Abnormal Calcium Handling.

    PubMed

    Opel, Aaisha; Nobles, Muriel; Montaigne, David; Finlay, Malcolm; Anderson, Naomi; Breckenridge, Ross; Tinker, Andrew

    2015-07-31

    The description of potential molecular substrates for predisposition to atrial fibrillation (AF) is incomplete, and it is unknown what role regulators of G-protein signaling might play. We address whether the attenuation of RGS4 function may promote AF and the mechanism through which this occurs. For this purpose, we studied a mouse with global genetic deletion of RGS4 (RGS4(-/-)) and the normal littermate controls (RGS4(+/+)). In vivo electrophysiology using atrial burst pacing revealed that mice with global RGS4 deletion developed AF more frequently than control littermates. Isolated atrial cells from RGS4(-/-) mice show an increase in Ca(2+) spark frequency under basal conditions and after the addition of endothelin-1 and abnormal spontaneous Ca(2+) release events after field stimulation. Isolated left atria studied on a multielectrode array revealed modest changes in path length for re-entry but abnormal electrical events after a pacing train in RGS4(-/-) mice. RGS4 deletion results in a predisposition to atrial fibrillation from enhanced activity in the Gαq/11-IP3 pathway, resulting in abnormal Ca(2+) release and corresponding electrical events. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Exogenous calcium alleviates photoinhibition of PSII by improving the xanthophyll cycle in peanut (Arachis hypogaea) leaves during heat stress under high irradiance.

    PubMed

    Yang, Sha; Wang, Fang; Guo, Feng; Meng, Jing-Jing; Li, Xin-Guo; Dong, Shu-Ting; Wan, Shu-Bo

    2013-01-01

    Peanut is one of the calciphilous plants. Calcium (Ca) serves as a ubiquitous central hub in a large number of signaling pathways. The effect of exogenous calcium nitrate [Ca(NO3)2] (6 mM) on the dissipation of excess excitation energy in the photosystem II (PSII) antenna, especially on the level of D1 protein and the xanthophyll cycle in peanut plants under heat (40°C) and high irradiance (HI) (1 200 µmol m(-2) s(-1)) stress were investigated. Compared with the control plants [cultivated in 0 mM Ca(NO3)2 medium], the maximal photochemical efficiency of PSII (Fv/Fm) in Ca(2+)-treated plants showed a slighter decrease after 5 h of stress, accompanied by higher non-photochemical quenching (NPQ), higher expression of antioxidative genes and less reactive oxygen species (ROS) accumulation. Meanwhile, higher content of D1 protein and higher ratio of (A+Z)/(V+A+Z) were also detected in Ca(2+)-treated plants under such stress. These results showed that Ca(2+) could help protect the peanut photosynthetic system from severe photoinhibition under heat and HI stress by accelerating the repair of D1 protein and improving the de-epoxidation ratio of the xanthophyll cycle. Furthermore, EGTA (a chelant of Ca ion), LaCl3 (a blocker of Ca(2+) channel in cytoplasmic membrane), and CPZ [a calmodulin (CaM) antagonist] were used to analyze the effects of Ca(2+)/CaM on the variation of (A+Z)/(V+A+Z) (%) and the expression of violaxanthin de-epoxidase (VDE). The results indicated that CaM, an important component of the Ca(2+) signal transduction pathway, mediated the expression of the VDE gene in the presence of Ca to improve the xanthophyll cycle.

  19. Occurrence of molecular abnormalities of cell cycle in L132 cells after in vitro short-term exposure to air pollution PM(2.5).

    PubMed

    Abbas, Imane; Garçon, Guillaume; Saint-Georges, Françoise; Billet, Sylvain; Verdin, Anthony; Gosset, Pierre; Mulliez, Philippe; Shirali, Pirouz

    2010-12-05

    To improve the knowledge of the underlying mechanisms implying in air pollution Particulate Matter (PM)-induced lung toxicity in humans, we were interested in the sequential occurrence of molecular abnormalities from TP53-RB gene signaling pathway activation in the L132 target human lung epithelial cell model. The most toxicologically relevant physical and chemical characteristics of air pollution PM(2.5) collected in Dunkerque, a French highly-industrialized sea-side city, were determined. L132 cells were exposed during 24, 48 and 72h to Dunkerque City's PM(2.5) (i.e. Lethal Concentration (LC)(10)=18.84μgPM/mL or 5.02μgPM/cm(2); LC(50)=75.36μgPM/mL or 20.10μgPM/cm(2)), TiO(2) and desorbed PM (i.e. dPM; EqLC(10)=15.42μg/mL or 4.11μgPM/cm(2); EqLC(50)=61.71μg/mL or 16.46μgPM/cm(2)), benzene (7μM) or Benzo[a]Pyrene (B[a]P; 1μM). Dunkerque City's PM(2.5) altered the gene expression and/or the protein concentration of several key cell cycle controllers from TP53-RB gene signaling pathway (i.e. P53; BCL2; P21; cyclin D1, cyclin-dependent kinase 1; retinoblastoma protein) in L132 cells, thereby leading to the occurrence of cell proliferation and apoptosis together. The activation of the critical cell cycle controllers under study might be related to PM-induced oxidative stress, through the possible involvement of covalent metals in redox systems, the metabolic activation of organic chemicals by enzyme-catalyzed reactions, and phagocytosis. Taken together, these results might ask the critical question whether there is a balance or, in contrast, rather an imbalance between the cell proliferation and the apoptosis occurring in PM-exposed L132 cells, with possible consequences in term of PM-induced lung tumorgenesis.

  20. Effects of iron and calcium carbonate on the variation and cycling of carbon source in integrated wastewater treatments.

    PubMed

    Zhimiao, Zhao; Xinshan, Song; Yufeng, Zhao; Yanping, Xiao; Yuhui, Wang; Junfeng, Wang; Denghua, Yan

    2017-02-01

    Iron and calcium carbonate were added in wastewater treatments as the adjusting agents to improve the contaminant removal performance and regulate the variation of carbon source in integrated treatments. At different temperatures, the addition of the adjusting agents obviously improved the nitrogen and phosphorous removals. TN and TP removals were respectively increased by 29.41% and 23.83% in AC-100 treatment under 1-day HRT. Carbon source from dead algae was supplied as green microbial carbon source and Fe(2+) was supplied as carbon source surrogate. COD concentration was increased to 30mg/L and above, so the problem of the shortage of carbon source was solved. Dead algae and Fe(2+) as carbon source supplement or surrogate played significant role, which was proved by microbial community analysis. According to the denitrification performance in the treatments, dead algae as green microbial carbon source combined with iron and calcium carbonate was the optimal supplement carbon source in wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Calsequestrin-Mediated Mechanism for Cellular Calcium Transient Alternans

    PubMed Central

    Restrepo, Juan G.; Weiss, James N.; Karma, Alain

    2008-01-01

    Intracellular calcium transient alternans (CTA) has a recognized role in arrhythmogenesis, but its origin is not yet fully understood. Recent models of CTA are based on a steep relationship between calcium release from the sarcoplasmic reticulum (SR) and its calcium load before release. This mechanism alone, however, does not explain recent observations of CTA without diastolic SR calcium content alternations. In addition, nanoscopic imaging of calcium dynamics has revealed that the elementary calcium release units of the SR can become refractory independently of their local calcium content. Here we show using a new physiologically detailed mathematical model of calcium cycling that luminal gating of the calcium release channels (RyRs) mediated by the luminal buffer calsequestrin (CSQN) can cause CTA independently of the steepness of the release-load relationship. In this complementary mechanism, CTA is caused by a beat-to-beat alternation in the number of refractory RyR channels and can occur with or without diastolic SR calcium content alternans depending on pacing conditions and uptake dynamics. The model has unique features, in that it treats a realistic number of spatially distributed and diffusively coupled dyads, each one with a realistic number of RyR channels, and that luminal CSQN buffering and gating is incorporated based on experimental data that characterizes the effect of the conformational state of CSQN on its buffering properties. In addition to reproducing observed features of CTA, this multiscale model is able to describe recent experiments in which CSQN expression levels were genetically altered as well as to reproduce nanoscopic measurements of spark restitution properties. The ability to link microscopic properties of the calcium release units to whole cell behavior makes this model a powerful tool to investigate the arrhythmogenic role of abnormal calcium handling in many pathological settings. PMID:18676655

  2. Calcium supplements

    MedlinePlus

    ... TYPES OF CALCIUM SUPPLEMENTS Forms of calcium include: Calcium carbonate: Over-the-counter (OTC) antacid products, such as Tums and Rolaids, contain calcium carbonate. These sources of calcium do not cost much. ...

  3. Remineralization potential of bioactive glass and casein phosphopeptide-amorphous calcium phosphate on initial carious lesion: An in-vitro pH-cycling study

    PubMed Central

    Mehta, Adit Bharat; Kumari, Veena; Jose, Rani; Izadikhah, Vajiheh

    2014-01-01

    Aims: The aim of this study was to evaluate and compare the remineralization potential of bioactive-Glass (BAG) (Novamin®/Calcium-sodium-phosphosilicate) and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) containing dentifrice. Materials and Methods: A total of 30 sound human premolars were decoronated, coated with nail varnish except for a 4 mm × 4 mm window on the buccal surface of crown and were randomly divided in two groups (n = 15). Group A — BAG dentifrice and Group B — CPP-ACP dentifrice. The baseline surface microhardness (SMH) was measured for all the specimens using the vickers microhardness testing machine. Artificial enamel carious lesions were created by inserting the specimens in de-mineralizing solution for 96 h. SMH of demineralized specimens was evaluated. 10 days of pH-cycling regimen was carried out. SMH of remineralized specimens was evaluated. Statistical Analysis: Data was analyzed using ANOVA and multiple comparisons within groups was done using Bonferroni method (post-hoc tests) to detect significant differences at P < 0.05 levels. Results: Group A showed significantly higher values (P < 0.05) when compared with the hardness values of Group B. Conclusions: Within the limits; the present study concluded that; both BAG and CPP-ACP are effective in remineralizing early enamel caries. Application of BAG more effectively remineralized the carious lesion when compared with CPP-ACP. PMID:24554851

  4. Calcium and magnesium content of the uterine fluid and blood serum during the estrous cycle and pre-pubertal phase in water buffaloes.

    PubMed

    Alavi Shoushtari, Sayed Mortaza; Asri Rezaie, Siamak; Khaki, Amir; Belbasi, Abulfazle; Tahmasebian, Hamid

    2014-01-01

    To investigate uterine fluid and serum calcium (Ca) and Magnesium (Mg) variations during the estrus cycle in water buffaloes, 71 genital tracts and blood samples were collected from the abattoir in Urmia. The phase of the estrous cycle was determined by examining ovarian structures. 18 animals were pro-estrous, 15 estrous, 16 met-estrous and 22 diestrous. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. Blood serum and uterine fluid samples of 71 pre-pubertal buffalo calves were also collected and treated in similar manners. The mean ± SEM total serum and uterine fluid Ca in cyclic buffaloes were 8.68 ± 0.28 mg dL(-1) and 8.10 ± 0.2 mg dL(-1) vs. 6.76 ± 0.65 mg dL(-1) and 7.90 ± 0.15 mg dL(-1) in pre-pubertal calves, respectively. Blood serum Mg was not different in cyclic and pre-pubertal animals but the uterine fluid Mg in cyclic cows was higher than those in pre-pubertal calves. Serum Ca in pro-estrus and estrus were higher than those in other stages and also higher than those in the uterine fluid. The lowest Mg content of serum was recorded in diestrus, while in the uterine fluid it was observed in estrus. In all stages of estrous cycle except for estrus the uterine fluid Mg content was significantly higher than those of the serum. These results suggested that during the estrous cycle in the buffalo cows, Ca was passively secreted in uterine lumen and mostly dependent on blood serum Ca concentrations but Mg was secreted independently. The values (except for serum total Mg) also increased after puberty.

  5. Calcium and magnesium content of the uterine fluid and blood serum during the estrous cycle and pre-pubertal phase in water buffaloes

    PubMed Central

    Alavi Shoushtari, Sayed Mortaza; Asri Rezaie, Siamak; Khaki, Amir; Belbasi, Abulfazle; Tahmasebian, Hamid

    2014-01-01

    To investigate uterine fluid and serum calcium (Ca) and Magnesium (Mg) variations during the estrus cycle in water buffaloes, 71 genital tracts and blood samples were collected from the abattoir in Urmia. The phase of the estrous cycle was determined by examining ovarian structures. 18 animals were pro-estrous, 15 estrous, 16 met-estrous and 22 diestrous. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. Blood serum and uterine fluid samples of 71 pre-pubertal buffalo calves were also collected and treated in similar manners. The mean ± SEM total serum and uterine fluid Ca in cyclic buffaloes were 8.68 ± 0.28 mg dL-1 and 8.10 ± 0.2 mg dL-1 vs. 6.76 ± 0.65 mg dL-1 and 7.90 ± 0.15 mg dL-1 in pre-pubertal calves, respectively. Blood serum Mg was not different in cyclic and pre-pubertal animals but the uterine fluid Mg in cyclic cows was higher than those in pre-pubertal calves. Serum Ca in pro-estrus and estrus were higher than those in other stages and also higher than those in the uterine fluid. The lowest Mg content of serum was recorded in diestrus, while in the uterine fluid it was observed in estrus. In all stages of estrous cycle except for estrus the uterine fluid Mg content was significantly higher than those of the serum. These results suggested that during the estrous cycle in the buffalo cows, Ca was passively secreted in uterine lumen and mostly dependent on blood serum Ca concentrations but Mg was secreted independently. The values (except for serum total Mg) also increased after puberty. PMID:25610582

  6. Overexpression of Sarcoendoplasmic Reticulum Calcium ATPase 2a Promotes Cardiac Sympathetic Neurotransmission via Abnormal Endoplasmic Reticulum and Mitochondria Ca2+ Regulation

    PubMed Central

    Shanks, Julia; Herring, Neil; Johnson, Errin; Liu, Kun; Li, Dan

    2017-01-01

    Reduced cardiomyocyte excitation–contraction coupling and downregulation of the SERCA2a (sarcoendoplasmic reticulum calcium ATPase 2a) is associated with heart failure. This has led to viral transgene upregulation of SERCA2a in cardiomyocytes as a treatment. We hypothesized that SERCA2a gene therapy expressed under a similar promiscuous cytomegalovirus promoter could also affect the cardiac sympathetic neural axis and promote sympathoexcitation. Stellate neurons were isolated from 90 to 120 g male, Sprague–Dawley, Wistar Kyoto, and spontaneously hypertensive rats. Neurons were infected with Ad-mCherry or Ad-mCherry-hATP2Aa (SERCA2a). Intracellular Ca2+ changes were measured using fura-2AM in response to KCl, caffeine, thapsigargin, and carbonylcyanide-p-trifluoromethoxyphenylhydrazine to mobilize intracellular Ca2+ stores. The effect of SERCA2a on neurotransmitter release was measured using [3H]-norepinephrine overflow from 340 to 360 g Sprague–Dawley rat atria in response to right stellate ganglia stimulation. Upregulation of SERCA2a resulted in greater neurotransmitter release in response to stellate stimulation compared with control (empty: 98.7±20.5 cpm, n=7; SERCA: 186.5±28.41 cpm, n=8; P<0.05). In isolated Sprague–Dawley rat stellate neurons, SERCA2a overexpression facilitated greater depolarization-induced Ca2+ transients (empty: 0.64±0.03 au, n=57; SERCA: 0.75±0.03 au, n=68; P<0.05), along with increased endoplasmic reticulum and mitochondria Ca2+ load. Similar results were observed in Wistar Kyoto and age-matched spontaneously hypertensive rats, despite no further increase in endoplasmic reticulum load being observed in the spontaneously hypertensive rat (spontaneously hypertensive rats: empty, 0.16±0.04 au, n=18; SERCA: 0.17±0.02 au, n=25). In conclusion, SERCA2a upregulation in cardiac sympathetic neurons resulted in increased neurotransmission and increased Ca2+ loading into intracellular stores. Whether the increased Ca2+ transient and

  7. Calcium and magnesium concentrations in uterine fluid and blood serum during the estrous cycle in the bovine.

    PubMed

    Alavi-Shoushtari, Sayed Mortaza; Asri-Rezaie, Siamak; Abedizadeh, Roya; Khaki, Amir; Pak, Mozhgan; Alizadeh, Sajad

    2012-01-01

    To investigate uterine and serum Ca(++) and Mg(++) variations during the estrous cycle in the bovine, 66 genital tracts and blood samples were collected from Urmia abattoir, Urmia, Iran. The phase of the estrous cycle was determined by examination of the structures present on ovaries and uterine tonicity. Of the collected samples, 17 were pro-estrus, 12 estrus, 14 metestrus and 23 diestrus. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. The mean ± SEM concentration of serum Ca(++) in pro-estrus, estrus, metestrus and diestrus was 5.77 ± 0.69, 8.87 ± 1.83, 10.95 ± 1.52, 11.09 ± 1.08 mg dL(-1), and the mean concentration of uterine fluid Ca(++) was 4.40 ± 0.72, 3.15 ± 0.67, 5.89 ± 0.88, 8.63 ± 0.97 mg dL(-1), respectively. The mean concentration of serum Mg(++) in pro-estrus, estrus, metestrus and diestrus was 3.53 ± 0.30, 4.20 ± 0.52, 3.49 ± 0.38, 3.39 ± 0.29 mg dL(-1), and mean concentration of uterine fluid Mg(++) was 5.27 ± 0.42, 4.92 ± 0.60, 5.56 ± 0.30, 5.88 ± 0.36 mg dL(-1), respectively. The serum and uterine fluid Ca(++) in pro-estrus were significantly different from those of the metestrus and diestrus. In all stages of estrous cycle the mean concentration of serum Ca(++) was higher than that in the uterine fluid. The difference between serum and uterine fluid Ca(++) in estrus, metestrus and diestrus was significant. There was no significant difference between serum Mg(++) content nor was it different from uterine fluid Mg(++) content at any stages of estrous cycle. In all stages of estrous cycle the uterine fluid Mg(++) was higher than that of the serum. These results suggest that during the estrous cycle in the cow, Ca(++) is passively secreted in uterine fluids and is mostly dependent on blood serum Ca(++) variations but Mg(++) is secreted independently and does not follow variations in the serum concentrations.

  8. Action of calcium ions on spinach (Spinacia oleracea) chloroplast fructose bisphosphatase and other enzymes of the Calvin cycle.

    PubMed Central

    Charles, S A; Halliwell, B

    1980-01-01

    Thiol-treated spinach (Spinacia oleracea) chloroplast fructose bisphosphatase is powerfully inhibited by Ca2+ non-competitively with respect to its substrate, fructose 1,6-bisphosphate. 500 microM-Ca2+ causes virtually complete inhibition and the Ki is 40 microM. Severe inhibition of sedoheptulose bisphosphatase is also caused by Ca2+. A role for Ca2+ in regulation of the Calvin cycle in spinach chloroplasts is proposed. PMID:6258561

  9. Meiotic abnormalities

    SciTech Connect

    1993-12-31

    Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

  10. Molt cycle-associated changes in calcium-dependent proteinase activity that degrades actin and myosin in crustacean muscle

    SciTech Connect

    Mykles, D.L.; Skinner, D.M.

    1982-01-01

    The role of calcium-dependent proteinase (CDP) in the proecdysial atrophy of crustacean claw muscle has been investigated. During atrophy the molar ratio of actin to myosin heavy chain decreased 31%, confirming earlier ultrastructural observations that the ratio of thin:thick myofilaments declined from 9:1 to 6:1 (D.L. Mykles and D.M. Skinner, 1981, J. Ultrastruct. Res. 75, 314 to 325). The release of TCA-soluble material in muscle homogenates at neutral pH was stimulated by Ca/sup 2 +/ and completely inhibited by EGTA. The specific degradation of the major myofibrillar proteins (actin, myosin heavy and light chains, paramyosin, tropomyosin, troponin-T, and troponin-I) was demonstrated by SDS-polyacrylamide gel electrophoresis. Proteolytic activity was more than twofold greater in proecdysial muscle homogenates. Degradation of myofibrillar proteins was inhibited by EGTA, and the two inhibitors of crysteine proteinases, leupeptin, and antipain, but not pepstatin, an inhibitor of aspartic proteinases. Unlike CDPs from vertebrate muscle, the CDP(s) in crab claw muscle degrades actin and myosin in addition to other myofibrillar proteins.

  11. Middle Holocene daily light cycle reconstructed from the strontium/calcium ratios of a fossil giant clam shell

    NASA Astrophysics Data System (ADS)

    Hori, Masako; Sano, Yuji; Ishida, Akizumi; Takahata, Naoto; Shirai, Kotaro; Watanabe, Tsuyoshi

    2015-03-01

    Insolation is an important component of meteorological data because solar energy is the primary and direct driver of weather and climate. Previous analyses of cultivated giant clam shells revealed diurnal variation in the Sr/Ca ratio, which might reflect the influence of the daily light cycle. We applied proxy method to sample from prehistoric era, a fossil giant clam shell collected at Ishigaki Island in southern Japan. The specimen was alive during the middle Holocene and thus exposed to the warmest climate after the last glacial period. This bivalve species is known to form a growth line each day, as confirmed by the analysis of the Sr enrichment bands using EPMA and facilitated age-model. We analyzed the Sr/Ca, Mg/Ca and Ba/Ca ratios along the growth axis, measuring a 2-μm spot size at 2-μm interval using NanoSIMS. The Sr/Ca ratios in the winter layers are characterized by a striking diurnal cycle consisting of narrow growth lines with high Sr/Ca ratios and broad growth bands with low Sr/Ca ratios. These variations, which are consistent with those of the cultivated clam shell, indicate the potential for the reconstruction of the variation in solar insolation during the middle Holocene at a multi-hourly resolution.

  12. Effect of cerium oxide doping on the performance of CaO-based sorbents during calcium looping cycles.

    PubMed

    Wang, Shengping; Fan, Shasha; Fan, Lijing; Zhao, Yujun; Ma, Xinbin

    2015-04-21

    A series of CaO-based sorbents were synthesized through a sol-gel method and doped with different amounts of CeO2. The sorbent with a Ca/Ce molar ratio of 15:1 showed an excellent absorption capacity (0.59 gCO2/g sorbent) and a remarkable cycle durability (up to 18 cycles). The admirable capture performance of CaCe-15 was ascribed to its special morphology formed by the doping of CeO2 and the well-distributed CeO2 particles. The sorbents doped with CeO2 possessed a loose shell-connected cross-linking structure, which was beneficial for the contact between CaO and CO2. CaO and CeO2 were dispersed homogeneously, and the existence of CeO2 also decreased the grain size of CaO. The well-dispersed CeO2, which could act as a barrier, effectively prevented the CaO crystallite from growing and sintering, thus the sorbent exhibited outstanding stability. The doping of CeO2 also improved the carbonation rate of the sorbent, resulting in a high capacity in a short period of time.

  13. Middle Holocene daily light cycle reconstructed from the strontium/calcium ratios of a fossil giant clam shell.

    PubMed

    Hori, Masako; Sano, Yuji; Ishida, Akizumi; Takahata, Naoto; Shirai, Kotaro; Watanabe, Tsuyoshi

    2015-03-04

    Insolation is an important component of meteorological data because solar energy is the primary and direct driver of weather and climate. Previous analyses of cultivated giant clam shells revealed diurnal variation in the Sr/Ca ratio, which might reflect the influence of the daily light cycle. We applied proxy method to sample from prehistoric era, a fossil giant clam shell collected at Ishigaki Island in southern Japan. The specimen was alive during the middle Holocene and thus exposed to the warmest climate after the last glacial period. This bivalve species is known to form a growth line each day, as confirmed by the analysis of the Sr enrichment bands using EPMA and facilitated age-model. We analyzed the Sr/Ca, Mg/Ca and Ba/Ca ratios along the growth axis, measuring a 2-μm spot size at 2-μm interval using NanoSIMS. The Sr/Ca ratios in the winter layers are characterized by a striking diurnal cycle consisting of narrow growth lines with high Sr/Ca ratios and broad growth bands with low Sr/Ca ratios. These variations, which are consistent with those of the cultivated clam shell, indicate the potential for the reconstruction of the variation in solar insolation during the middle Holocene at a multi-hourly resolution.

  14. Middle Holocene daily light cycle reconstructed from the strontium/calcium ratios of a fossil giant clam shell

    PubMed Central

    Hori, Masako; Sano, Yuji; Ishida, Akizumi; Takahata, Naoto; Shirai, Kotaro; Watanabe, Tsuyoshi

    2015-01-01

    Insolation is an important component of meteorological data because solar energy is the primary and direct driver of weather and climate. Previous analyses of cultivated giant clam shells revealed diurnal variation in the Sr/Ca ratio, which might reflect the influence of the daily light cycle. We applied proxy method to sample from prehistoric era, a fossil giant clam shell collected at Ishigaki Island in southern Japan. The specimen was alive during the middle Holocene and thus exposed to the warmest climate after the last glacial period. This bivalve species is known to form a growth line each day, as confirmed by the analysis of the Sr enrichment bands using EPMA and facilitated age-model. We analyzed the Sr/Ca, Mg/Ca and Ba/Ca ratios along the growth axis, measuring a 2-μm spot size at 2-μm interval using NanoSIMS. The Sr/Ca ratios in the winter layers are characterized by a striking diurnal cycle consisting of narrow growth lines with high Sr/Ca ratios and broad growth bands with low Sr/Ca ratios. These variations, which are consistent with those of the cultivated clam shell, indicate the potential for the reconstruction of the variation in solar insolation during the middle Holocene at a multi-hourly resolution. PMID:25736488

  15. Congenital Abnormalities

    MedlinePlus

    ... while you are pregnant. Combination of Genetic and Environmental Problems Some congenital abnormalities may occur if there is a genetic tendency for the condition combined with exposure to certain environmental influences within the womb during critical stages of ...

  16. Multiple short windows of calcium-dependent protein kinase 4 activity coordinate distinct cell cycle events during Plasmodium gametogenesis.

    PubMed

    Fang, Hanwei; Klages, Natacha; Baechler, Bastien; Hillner, Evelyn; Yu, Lu; Pardo, Mercedes; Choudhary, Jyoti; Brochet, Mathieu

    2017-05-08

    Malaria transmission relies on the production of gametes following ingestion by a mosquito. Here, we show that Ca(2+)-dependent protein kinase 4 controls three processes essential to progress from a single haploid microgametocyte to the release of eight flagellated microgametes in Plasmodium berghei. A myristoylated isoform is activated by Ca(2+) to initiate a first genome replication within twenty seconds of activation. This role is mediated by a protein of the SAPS-domain family involved in S-phase entry. At the same time, CDPK4 is required for the assembly of the subsequent mitotic spindle and to phosphorylate a microtubule-associated protein important for mitotic spindle formation. Finally, a non-myristoylated isoform is essential to complete cytokinesis by activating motility of the male flagellum. This role has been linked to phosphorylation of an uncharacterised flagellar protein. Altogether, this study reveals how a kinase integrates and transduces multiple signals to control key cell-cycle transitions during Plasmodium gametogenesis.

  17. Abnormal integrity of the nucleolus associated with cell cycle arrest owing to the temperature-sensitive ubiquitin-activating enzyme E1.

    PubMed

    Sudha, T; Tsuji, H; Sameshima, M; Matsuda, Y; Kaneda, S; Nagai, Y; Yamao, F; Seno, T

    1995-03-01

    A mouse cell mutant, ts85, containing the temperature-sensitive ubiquitin-activating enzyme was arrested in G2 phase at the non-permissive temperature. In the arrested cells, azure C, a nucleolus-specific stain, revealed a U-shaped or ring-shaped arrangement of nucleolar lobes with an unstained region in the center. Silver staining of the nucleolar organizer region (NOR) and fluorescence in situ hybridization (FISH) with rDNA both gave signals in azure C-positive regions. Electron microscopic examination revealed a cloud of unidentified electron-dense particles (diameter approximately 70 nm) in the azure C-negative center space. When the arrested cells were released into M-phase, we observed the association of NOR-bearing chromosomes with a pulverization-like abnormality. FISH with rDNA and NOR silver staining demonstrated that the pulverization-like abnormality was restricted to NORs. The frequent occurrence of persistent nucleolar material in prophase and prometaphase of the stressed cells after release indicated a delayed dissociation of the nucleolus that brought about the abnormal chromosomes in M-phase. ts85 cells transfected with the mouse E1 cDNA recovered growth at the non-permissive temperature and no longer showed abnormal nucleolar morphology. It seems that the ubiquitin system plays a role in the dissolution of the nucleolus, possibly involving the NOR-bearing chromosomes.

  18. Stabilizers of neuronal and mitochondrial calcium cycling as a strategy for developing a medicine for Alzheimer's disease.

    PubMed

    Fernández-Morales, José-Carlos; Arranz-Tagarro, Juan-Alberto; Calvo-Gallardo, Enrique; Maroto, Marcos; Padín, Juan-Fernando; García, Antonio G

    2012-11-21

    For the last two decades, most efforts on new drug development to treat Alzheimer's disease have been focused to inhibit the synthesis of amyloid beta (Aβ), to prevent Aβ deposition, or to clear up Aβ plaques from the brain of Alzheimer's disease (AD) patients. Other pathogenic mechanisms such as the hyperphosphorylation of the microtubular tau protein (that forms neurofibrillary tangles) have also been addressed as, for instance, with inhibitors of the enzyme glycogen synthase-3 kinase beta (GSK3β). However, in spite of their proven efficacy in animal models of AD, all these compounds have so far failed in clinical trials done in AD patients. It seems therefore desirable to explore new concepts and strategies in the field of drug development for AD. We analyze here our hypothesis that a trifunctional chemical entity acting on the L subtype of voltage-dependent Ca(2+) channels (VDCCs) and on the mitochondrial Na(+)/Ca(2+) exchanger (MNCX), and having additional antioxidant properties, may efficiently delay or stop the death of vulnerable neurons in the brain of AD patients. In recent years, evidence has accumulated indicating that enhanced neuronal Ca(2+) cycling (NCC) and futile mitochondrial Ca(2+) cycling (MCC) are central stage in activating calpain and calcineurin, as well as the intrinsic mitochondrial pathway for apoptosis, leading to death of vulnerable neurons. An additional contributing factor to neuronal death is the excess free radical production linked to distortion of Ca(2+) homeostasis. We propose that an hybrid compound containing a dihydropyridine moiety (to block L channels and mitigate Ca(2+) entry) and a benzothiazepine moiety (to block the MNCX and slow down the rate of Ca(2+) efflux from the mitochondrial matrix into the cytosol), as well as a polyphenol moiety (to sequester excess free radicals) could break down the pathological enhanced NCC and MCC, thus delaying the initiation of apoptosis and the death of vulnerable neurons. In so

  19. Stabilizers of Neuronal and Mitochondrial Calcium Cycling as a Strategy for Developing a Medicine for Alzheimer's Disease

    PubMed Central

    2012-01-01

    For the last two decades, most efforts on new drug development to treat Alzheimer's disease have been focused to inhibit the synthesis of amyloid beta (Aβ), to prevent Aβ deposition, or to clear up Aβ plaques from the brain of Alzheimer's disease (AD) patients. Other pathogenic mechanisms such as the hyperphosphorylation of the microtubular tau protein (that forms neurofibrillary tangles) have also been addressed as, for instance, with inhibitors of the enzyme glycogen synthase-3 kinase beta (GSK3β). However, in spite of their proven efficacy in animal models of AD, all these compounds have so far failed in clinical trials done in AD patients. It seems therefore desirable to explore new concepts and strategies in the field of drug development for AD. We analyze here our hypothesis that a trifunctional chemical entity acting on the L subtype of voltage-dependent Ca2+ channels (VDCCs) and on the mitochondrial Na+/Ca2+ exchanger (MNCX), and having additional antioxidant properties, may efficiently delay or stop the death of vulnerable neurons in the brain of AD patients. In recent years, evidence has accumulated indicating that enhanced neuronal Ca2+ cycling (NCC) and futile mitochondrial Ca2+ cycling (MCC) are central stage in activating calpain and calcineurin, as well as the intrinsic mitochondrial pathway for apoptosis, leading to death of vulnerable neurons. An additional contributing factor to neuronal death is the excess free radical production linked to distortion of Ca2+ homeostasis. We propose that an hybrid compound containing a dihydropyridine moiety (to block L channels and mitigate Ca2+ entry) and a benzothiazepine moiety (to block the MNCX and slow down the rate of Ca2+ efflux from the mitochondrial matrix into the cytosol), as well as a polyphenol moiety (to sequester excess free radicals) could break down the pathological enhanced NCC and MCC, thus delaying the initiation of apoptosis and the death of vulnerable neurons. In so doing, such a

  20. Leukocyte abnormalities.

    PubMed

    Gabig, T G

    1980-07-01

    Certain qualitative abnormalities in neutrophils and blood monocytes are associated with frequent, severe, and recurrent bacterial infections leading to fatal sepsis, while other qualitative defects demonstrated in vitro may have few or no clinical sequelae. These qualitative defects are discussed in terms of the specific functions of locomotion, phagocytosis, degranulation, and bacterial killing.

  1. Housing under abnormal light-dark cycles attenuates day/night expression rhythms of the clock genes Per1, Per2, and Bmal1 in the amygdala and hippocampus of mice.

    PubMed

    Moriya, Shunpei; Tahara, Yu; Sasaki, Hiroyuki; Ishigooka, Jun; Shibata, Shigenobu

    2015-10-01

    Although the results of previous studies have suggested that disruptions in circadian rhythms are involved in the pathogenesis of depression, no studies have examined the interaction of clock gene expression deficit and depression state. In this study, we examined clock gene expression levels and depressive-like behavior in mice housed under 3.5h light, 3.5h dark (T = 7) conditions to investigate the association between clock gene expression and depressive state. C57BL/6J mice were housed under a T = 24 cycle (12h light, 12h dark) or a T = 7 cycle and clock gene expression levels in the hippocampus and the amygdala were measured by real-time RT-PCR. Depressive state was evaluated by the forced swim test (FST). Although circadian rhythms of Per1 and Per2 clock gene expression in the hippocampus and amygdala were still detected under T = 7 conditions, rhythmicity and expression levels of both significantly decreased. Mice housed with a T = 7 cycle showed increased immobile time in the FST than those with a T = 24 cycle. The present results suggest that the presence of a depressive state around the early active phase of activity may be related to impairment of rhythmicity and expression levels of Per1 and Per2 genes under abnormal light-dark conditions. Copyright © 2015 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  2. Double Staining Cytologic Samples with Quantitative Feulgen-Thionin and Anti–Ki-67 Immunocytochemistry as a Method of Distinguishing Cells with Abnormal DNA Content from Normal Cycling Cells

    PubMed Central

    Li, Gerald; Guillaud, Martial; Follen, Michele; MacAulay, Calum

    2013-01-01

    Objective Ploidy analysis of Feulgen-thionin stained cervical cytology specimens has been shown to detect cases of high grade cervical dysplasia. However, ploidy analysis alone cannot always distinguish between cells with abnormal DNA content and normal cycling cells. We sought to use double staining with anti-Ki-67 immunocytochemistry to improve ploidy analysis. Study Design Cervical cytology specimens from 49 patients with various diagnoses, mostly dysplasias, from a previous study were used. Samples were double stained with Feulgen-thionin and anti-Ki-67 immunocytochemistry. Ki-67-negative cells were non-cycling, so non-diploid Ki-67-negative cells were likely truly abnormal cells. Results The area under the receiver operating characteristic curve for the ability to identify high-grade dysplasias was 0.73 for double staining and 0.74 for thionin-only ploidy analysis on cytospin specimens. At 90% specificity, sensitivities for double staining and thionin alone were 45% and 32%, respectively, but the difference was not statistically significant. Conclusion Double staining with Feulgen-thionin and anti-Ki-67 immunocytochemistry does not improve the ability of ploidy analysis of cervical cytology specimens to separate high- and low-grade dysplasias, but our insights into the technical aspects of double staining, especially the effects of antigen retrieval, give hope that this technique could be applied to other immunocytochemical stains that would have a greater ability to improve ploidy analysis. PMID:23301387

  3. Calcium Carbonate

    MedlinePlus

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

  4. Iontophoresis and sonophoresis stimulate epidermal cytokine expression at energies that do not provoke a barrier abnormality: lamellar body secretion and cytokine expression are linked to altered epidermal calcium levels.

    PubMed

    Choi, Eung Ho; Kim, Min Jung; Yeh, Byung-Il; Ahn, Sung Ku; Lee, Seung Hun

    2003-11-01

    We performed this study to identify whether the expression of epidermal cytokines is altered by changes in epidermal calcium content, independent of skin barrier disruption. Iontophoresis and sonophoresis with the energies that do not disrupt the skin barrier, but induce changes in the epidermal calcium gradient, were applied to the skin of hairless mice. Immediately after iontophoresis and sonophoresis, immersion in a solution containing calcium was carried out, and iontophoresis in either high- or low-calcium solutions was performed. The biopsy specimens were taken for real-time quantitative RT-PCR to detect changes in mRNA level of interleukin-1alpha (IL-1alpha), tumor necrosis factor-alpha (TNF-alpha), and transforming growth factor-beta in the epidermis and for immunohistochemical stain with primary antibodies to IL-1alpha and TNF-alpha. The expression of each cytokine mRNA increased in the epidermis treated with iontophoresis and sonophoresis compared to a nontreated control as well as in tape-stripped skin used as a positive control and was lower after immersion in a high-calcium solution than in low-calcium solution. IL-1alpha and TNF-alpha immunohistochemical protein staining increased with iontophoresis at low calcium. These studies suggest that changes in epidermal calcium can directly signal expression of epidermal cytokines in vivo, independent of changes in barrier function.

  5. Predictive value of derived calcium figures based on the measurement of ionised calcium.

    PubMed

    Gardner, M D; Dryburgh, F J; Fyffe, J A; Jenkins, A S

    1981-03-01

    The algorithms used in this hospital to assess calcium status are calculated ionised serum calcium and the serum calcium concentration adjusted for albumin. In order to establish their clinical usefulness, they were compared with the ionised calcium concentration measured on the Nova 2 instrument in patients with various calcium and protein abnormalities. Good correlation was found between the measured and calculated values. The predictive values for the calculated results and for total serum calcium concentrations are presented. In this series, the derived values were useful in predicting the serum ionised calcium concentration of the patients studied.

  6. Calcium Handling and Arrhythmogenesis.

    PubMed

    Bompotis, Georgios C; Pappas, Loukas K; Angelidis, Christos; Kossyvakis, Charalampos; Giannopoulos, Georgios; Deftereos, Spyridon

    2016-01-01

    Intracellular calcium homeostasis plays a fundamental role in the electric and mechanical function of the heart by modulating action potential pattern and duration, by linking cell membrane depolarization to myocardial contraction and by regulating cardiac automaticity. Abnormalities of intracellular calcium regulation disrupt the electrophysiological properties of the heart and create an arrhythmogenic milieu, which promotes atrial and ventricular arrhythmogenesis and impairs cardiac automaticity and atrioventricular conduction. In this brief review, we summarize the basic genetic, molecular and electrophysiological mechanisms linking inherited or acquired intracellular Ca(2+) dysregulation to arrhythmogenesis.

  7. Abnormal crystal growth in CH3NH3PbI3-xClx using a multi-cycle solution coating process

    SciTech Connect

    Dong, Qingfeng; Yuan, Yongbo; Shao, Yuchuan; Fang, Yanjun; Wang, Qi; Huang, Jinsong

    2015-06-23

    Recently, the efficiency of organolead trihalide perovskite solar cells has improved greatly because of improved material qualities with longer carrier diffusion lengths. Mixing chlorine in the precursor for mixed halide films has been reported to dramatically enhance the diffusion lengths of mixed halide perovskite films, mainly as a result of a much longer carrier recombination lifetime. Here we report that adding Cl containing precursor for mixed halide perovskite formation can induce the abnormal grain growth behavior that yields well-oriented grains accompanied by the appearance of some very large size grains. The abnormal grain growth becomes prominent only after multi-cycle coating of MAI : MACl blend precursor. The large grain size is found mainly to contribute to a longer carrier charge recombination lifetime, and thus increases the device efficiency to 18.9%, but without significantly impacting the carrier transport property. As a result, the strong correlation identified between material process and morphology provides guidelines for future material optimization and device efficiency enhancement.

  8. Determination of calcium carbonate and sodium carbonate melting curves up to Earth's transition zone pressures with implications for the deep carbon cycle

    NASA Astrophysics Data System (ADS)

    Li, Zeyu; Li, Jie; Lange, Rebecca; Liu, Jiachao; Militzer, Burkhard

    2017-01-01

    Melting of carbonated eclogite or peridotite in the mantle influences the Earth's deep volatile cycles and bears on the long-term evolution of the atmosphere. Existing data on the melting curves of calcium carbonate (CaCO3) and sodium carbonate (Na2CO3) are limited to 7 GPa and therefore do not allow a full understanding of carbon storage and cycling in deep Earth. We determined the melting curves of CaCO3 and Na2CO3 to the pressures of Earth's transition zone using a multi-anvil apparatus. Melting was detected in situ by monitoring a steep and large increase in ionic conductivity, or inferred from sunken platinum markers in recovered samples. The melting point of CaCO3 rises from 1870 K at 3 GPa to ∼2000 K at 6 GPa and then stays within 50 K of 2000 K between 6 and 21 GPa. In contrast, the melting point of Na2CO3 increases continuously from ∼1123 K at 3 GPa to ∼1950 K at 17 GPa. A pre-melting peak in the alternating current through solid CaCO3 is attributed to the transition from aragonite to calcite V. Accordingly the calcite V-aragonite-liquid invariant point is placed at 13 ± 1 GPa and 1970 ± 40 K, with the Clapeyron slope of the calcite V to aragonite transition constrained at ∼70 K/GPa. The experiments on CaCO3 suggest a slight decrease in the melting temperature from 8 to 13 GPa, followed by a slight increase from 14 to 21 GPa. The negative melting slope is consistent with the prediction from our ab initio simulations that the liquid may be more compressible and become denser than calcite V at sufficiently high pressure. The positive melting slope at higher pressures is supported by the ab initio prediction that aragonite is denser than the liquid at pressures up to 30 GPa. At transition zone pressures the melting points of CaCO3 are comparable to that of Na2CO3 but nearly 400 K and 500 K lower than that of MgCO3. The fusible nature of compressed CaCO3 may be partially responsible for the majority of carbonatitic melts found on Earth's surface

  9. Calcium isotope constraints on the marine carbon cycle and CaCO3 deposition during the late Silurian (Ludfordian) positive δ13C excursion

    NASA Astrophysics Data System (ADS)

    Farkaš, Juraj; Frýda, Jiří; Holmden, Chris

    2016-10-01

    This study investigates calcium isotope variations (δ 44 / 40 Ca) in late Silurian marine carbonates deposited in the Prague Basin (Czech Republic), which records one of the largest positive carbon isotope excursion (CIE) of the entire Phanerozoic, the mid-Ludfordian CIE, which is associated with major climatic changes (abrupt cooling) and global sea-level fluctuations. Our results show that during the onset of the CIE, when δ13 C increases rapidly from ∼0‰ to ∼8.5‰, δ 44 / 40Ca remains constant at about 0.3 ± 0.1 ‰ (relative to NIST 915a), while 87Sr/86Sr in well-preserved carbonates are consistent with a typical Ludfordian seawater composition (ranging from ∼0.70865 to ∼0.70875). Such decoupling between δ13 C and δ 44 / 40Ca trends during the onset of the CIE is consistent with the expected order-of-magnitude difference in the residence times of Ca (∼106yr) and C (∼105yr) in the open ocean, suggesting that the mid-Ludfordian CIE was caused by processes where the biogeochemical pathways of C and Ca in seawater were mechanistically decoupled. These processes may include: (i) near shore methanogenesis and photosynthesis, (ii) changes in oceanic circulation and stratification, and/or (iii) increased production and burial of organic C in the global ocean. The latter, however, is unlikely due to the lack of geological evidence for enhanced organic C burial, and also because of unrealistic parameterization of the ocean C cycle needed to generate the observed CIE over the relatively short time interval. In contrast, higher up in the section where δ13 C shifts back to pre-excursion baseline values, there is a correlated shift to higher δ 44 / 40Ca values. Such coupling of the records of Ca and C isotope changes in this part of the study section is inconsistent with the abovementioned differences in oceanic Ca and C residence times, indicating that the record of δ 44 / 40Ca changes does not faithfully reflect the evolution of the oceanic Ca

  10. Continuous Exposure to a Novel Stressor Based on Water Aversion Induces Abnormal Circadian Locomotor Rhythms and Sleep-Wake Cycles in Mice

    PubMed Central

    Miyazaki, Koyomi; Itoh, Nanako; Ohyama, Sumika; Kadota, Koji; Oishi, Katsutaka

    2013-01-01

    Psychological stressors prominently affect diurnal rhythms, including locomotor activity, sleep, blood pressure, and body temperature, in humans. Here, we found that a novel continuous stress imposed by the perpetual avoidance of water on a wheel (PAWW) affected several physiological diurnal rhythms in mice. One week of PAWW stress decayed robust circadian locomotor rhythmicity, while locomotor activity was evident even during the light period when the mice are normally asleep. Daytime activity was significantly upregulated, whereas nighttime activity was downregulated, resulting in a low amplitude of activity. Total daily activity gradually decreased with increasing exposure to PAWW stress. The mice could be exposed to PAWW stress for over 3 weeks without adaptation. Furthermore, continuous PAWW stress enhanced food intake, but decreased body weight and plasma leptin levels, indicating that sleep loss and PAWW stress altered the energy balance in these mice. The diurnal rhythm of corticosterone levels was not severely affected. The body temperature rhythm was diurnal in the stressed mice, but significantly dysregulated during the dark period. Plasma catecholamines were elevated in the stressed mice. Continuous PAWW stress reduced the duration of daytime sleep, especially during the first half of the light period, and increased nighttime sleepiness. Continuous PAWW stress also simultaneously obscured sleep/wake and locomotor activity rhythms compared with control mice. These sleep architecture phenotypes under stress are similar to those of patients with insomnia. The stressed mice could be entrained to the light/dark cycle, and when they were transferred to constant darkness, they exhibited a free-running circadian rhythm with a timing of activity onset predicted by the phase of their entrained rhythms. Circadian gene expression in the liver and muscle was unaltered, indicating that the peripheral clocks in these tissues remained intact. PMID:23383193

  11. Continuous exposure to a novel stressor based on water aversion induces abnormal circadian locomotor rhythms and sleep-wake cycles in mice.

    PubMed

    Miyazaki, Koyomi; Itoh, Nanako; Ohyama, Sumika; Kadota, Koji; Oishi, Katsutaka

    2013-01-01

    Psychological stressors prominently affect diurnal rhythms, including locomotor activity, sleep, blood pressure, and body temperature, in humans. Here, we found that a novel continuous stress imposed by the perpetual avoidance of water on a wheel (PAWW) affected several physiological diurnal rhythms in mice. One week of PAWW stress decayed robust circadian locomotor rhythmicity, while locomotor activity was evident even during the light period when the mice are normally asleep. Daytime activity was significantly upregulated, whereas nighttime activity was downregulated, resulting in a low amplitude of activity. Total daily activity gradually decreased with increasing exposure to PAWW stress. The mice could be exposed to PAWW stress for over 3 weeks without adaptation. Furthermore, continuous PAWW stress enhanced food intake, but decreased body weight and plasma leptin levels, indicating that sleep loss and PAWW stress altered the energy balance in these mice. The diurnal rhythm of corticosterone levels was not severely affected. The body temperature rhythm was diurnal in the stressed mice, but significantly dysregulated during the dark period. Plasma catecholamines were elevated in the stressed mice. Continuous PAWW stress reduced the duration of daytime sleep, especially during the first half of the light period, and increased nighttime sleepiness. Continuous PAWW stress also simultaneously obscured sleep/wake and locomotor activity rhythms compared with control mice. These sleep architecture phenotypes under stress are similar to those of patients with insomnia. The stressed mice could be entrained to the light/dark cycle, and when they were transferred to constant darkness, they exhibited a free-running circadian rhythm with a timing of activity onset predicted by the phase of their entrained rhythms. Circadian gene expression in the liver and muscle was unaltered, indicating that the peripheral clocks in these tissues remained intact.

  12. Negative Regulation of p21Waf1/Cip1 by Human INO80 Chromatin Remodeling Complex Is Implicated in Cell Cycle Phase G2/M Arrest and Abnormal Chromosome Stability.

    PubMed

    Cao, Lingling; Ding, Jian; Dong, Liguo; Zhao, Jiayao; Su, Jiaming; Wang, Lingyao; Sui, Yi; Zhao, Tong; Wang, Fei; Jin, Jingji; Cai, Yong

    2015-01-01

    We previously identified an ATP-dependent human Ino80 (INO80) chromatin remodeling complex which shares a set of core subunits with yeast Ino80 complex. Although research evidence has suggested that INO80 complex functions in gene transcription and genome stability, the precise mechanism remains unclear. Herein, based on gene expression profiles from the INO80 complex-knockdown in HeLa cells, we first demonstrate that INO80 complex negatively regulates the p21Waf1/Cip1 (p21) expression in a p53-mediated mechanism. In chromatin immunoprecipitation (ChIP) and a sequential ChIP (Re-ChIP) assays, we determined that the INO80 complex and p53 can bind to the same promoter region of p21 gene (-2.2 kb and -1.0 kb upstream of the p21 promoter region), and p53 is required for the recruitment of the INO80 complex to the p21 promoter. RNAi knockdown strategies of INO80 not only led to prolonged progression of cell cycle phase G2/M to G1, but it also resulted in abnormal chromosome stability. Interestingly, high expression of p21 was observed in most morphologically-changed cells, suggesting that negative regulation of p21 by INO80 complex might be implicated in maintaining the cell cycle process and chromosome stability. Together, our findings will provide a theoretical basis to further elucidate the cellular mechanisms of the INO80 complex.

  13. Negative Regulation of p21Waf1/Cip1 by Human INO80 Chromatin Remodeling Complex Is Implicated in Cell Cycle Phase G2/M Arrest and Abnormal Chromosome Stability

    PubMed Central

    Cao, Lingling; Ding, Jian; Dong, Liguo; Zhao, Jiayao; Su, Jiaming; Wang, Lingyao; Sui, Yi; Zhao, Tong; Wang, Fei; Jin, Jingji; Cai, Yong

    2015-01-01

    We previously identified an ATP-dependent human Ino80 (INO80) chromatin remodeling complex which shares a set of core subunits with yeast Ino80 complex. Although research evidence has suggested that INO80 complex functions in gene transcription and genome stability, the precise mechanism remains unclear. Herein, based on gene expression profiles from the INO80 complex-knockdown in HeLa cells, we first demonstrate that INO80 complex negatively regulates the p21Waf1/Cip1 (p21) expression in a p53-mediated mechanism. In chromatin immunoprecipitation (ChIP) and a sequential ChIP (Re-ChIP) assays, we determined that the INO80 complex and p53 can bind to the same promoter region of p21 gene (-2.2kb and -1.0kb upstream of the p21 promoter region), and p53 is required for the recruitment of the INO80 complex to the p21 promoter. RNAi knockdown strategies of INO80 not only led to prolonged progression of cell cycle phase G2/M to G1, but it also resulted in abnormal chromosome stability. Interestingly, high expression of p21 was observed in most morphologically-changed cells, suggesting that negative regulation of p21 by INO80 complex might be implicated in maintaining the cell cycle process and chromosome stability. Together, our findings will provide a theoretical basis to further elucidate the cellular mechanisms of the INO80 complex. PMID:26340092

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

    Treesearch

    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...

  15. Calcium Test

    MedlinePlus

    ... Hyperthyroidism Sarcoidosis Tuberculosis Prolonged immobilization Excess vitamin D intake Thiazide diuretics Kidney transplant HIV/AIDS Low total calcium (hypocalcemia) The most common cause of low total calcium is: Low blood protein levels, especially a low level of albumin , which ...

  16. Effects of seawater alkalinity on calcium and acid-base regulation in juvenile European lobster (Homarus gammarus) during a moult cycle.

    PubMed

    Middlemiss, Karen L; Urbina, Mauricio A; Wilson, Rod W

    2016-03-01

    Fluxes of NH4(+) (acid) and HCO3(-) (base), and whole body calcium content were measured in European lobster (Homarus gammarus) during intermoult (megalopae stage), and during the first 24h for postmoult juveniles under control (~2000 μeq/L) and low seawater alkalinity (~830 μeq/L). Immediately after moulting, animals lost 45% of the total body calcium via the shed exoskeleton (exuvia), and only 11% was retained in the uncalcified body. At 24h postmoult, exoskeleton calcium increased to ~46% of the intermoult stage. Ammonia excretion was not affected by seawater alkalinity. After moulting, bicarbonate excretion was immediately reversed from excretion to uptake (~4-6 fold higher rates than intermoult) over the whole 24h postmoult period, peaking at 3-6h. These data suggest that exoskeleton calcification is not completed by 24h postmoult. Low seawater alkalinity reduced postmoult bicarbonate uptake by 29% on average. Net acid-base flux (equivalent to net base uptake) followed the same pattern as HCO3(-) fluxes, and was 22% lower in low alkalinity seawater over the whole 24h postmoult period. The common occurrence of low alkalinity in intensive aquaculture systems may slow postmoult calcification in juvenile H. gammarus, increasing the risk of mortalities through cannibalism. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Calcium-sensing receptors.

    PubMed

    Goodman, William G

    2004-01-01

    It is now known that variations in extracellular calcium concentration exert diverse physiologic effects in a variety of tissues that are mediated by a calcium-sensing receptor (CaSRs). In parathyroid tissue, the CaSR represents the molecular mechanism by which parathyroid cells detect changes in blood ionized calcium concentration, modulate parathyroid hormone (PTH) secretion accordingly, and thus maintain serum calcium levels within a narrow physiologic range. In the kidney, the CaSR regulates renal calcium excretion and influences the transepithelial movement of water and other electrolytes. More generally, activation of the CaSR represents an important signal transduction pathway in intestine, placenta, brain, and perhaps bone. Some of these actions involve cell cycle regulation, changes that may be relevant to understanding the pathogenesis of parathyroid gland hyperplasia in secondary hyperparathyroidism caused by chronic kidney disease. The CaSR represents an appealing target for therapeutic agents designed to modify parathyroid gland function in vivo, offering the prospect of novel therapies for selected disorders of bone and mineral metabolism. Other receptors capable of responding to extracellular calcium ions also have been identified, but the functional importance of these interactions remains to be determined.

  18. International evaluation of unrecognizably uglifying human faces in late and severe secondary hyperparathyroidism in chronic kidney disease. Sagliker syndrome. A unique catastrophic entity, cytogenetic studies for chromosomal abnormalities, calcium-sensing receptor gene and GNAS1 mutations. Striking and promising missense mutations on the GNAS1 gene exons 1, 4, 10, 4.

    PubMed

    Yildiz, Ismail; Sagliker, Yahya; Demirhan, Osman; Tunc, Erdal; Inandiklioglu, Nihal; Tasdemir, Deniz; Acharya, Vidya; Zhang, Ling; Golea, Ovidia; Sabry, Alaa; Ookalkar, Dhananjay S; Capusa, Cristina; Radulescu, Dana; Garneata, Liliana; Mircescu, Gabriel; Ben Maiz, Hedi; Chen, Cheng Hsu; Prado Rome, Jorge; Benzegoutta, Mansour; Paylar, Nuray; Eyuboglu, Kamil; Karatepe, Ersin; Esenturk, Mustafa; Yavascan, Onder; Grzegorzevska, Alicza; Shilo, Valery; Mazdeh, Mitra Mahdavi; Francesco, Ramos Carillo; Gouda, Zaghloul; Adam, Siddik Momin; Emir, Idris; Ocal, Faith; Usta, Erol; Kiralp, Necati; Sagliker, Cemal; Ozkaynak, Piril Sagliker; Sagliker, Hasan Sabit; Bassuoni, Mahmoud; Sekin, Oktay

    2012-01-01

    Hypotheses explaining pathogenesis of secondary hyperparathyroidism (SH) in late and severe CKD as a unique entity called Sagliker syndrome (SS) are still unclear. This international study contains 60 patients from Turkey, India, Malaysia, China, Romania, Egypt, Tunisia, Taiwan, Mexico, Algeria, Poland, Russia, and Iran. We examined patients and first degree relatives for cytogenetic chromosomal abnormalities, calcium sensing receptor (Ca SR) genes in exons 2 and 3 abnormalities and GNAS1 genes mutations in exons 1, 4, 5, 7, 10, 13. Our syndrome could be a new syndrome in between SH, CKD, and hereditary bone dystrophies. We could not find chromosomal abnormalities in cytogenetics and on Ca SR gene exons 2 and 3. Interestingly, we did find promising missense mutations on the GNAS1 gene exons 1, 4, 10, 4. We finally thought that those catastrophic bone diseases were severe SH and its late treatments due to monetary deficiencies and iatrogenic mistreatments not started as early as possible. This was a sine qua non humanity task. Those brand new striking GNAS1 genes missense mutations have to be considered from now on for the genesis of SS. Copyright © 2012 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  19. Calcium and aluminum cycling in a temperate broadleaved deciduous forest of the eastern USA: relative impacts of tree species, canopy state, and flux type.

    PubMed

    Levia, Delphis F; Shiklomanov, Alexey N; Van Stan, John T; Scheick, Carrie E; Inamdar, Shreeram P; Mitchell, Myron J; McHale, Patrick J

    2015-07-01

    Ca/Al molar ratios are commonly used to assess the extent of aluminum stress in forests. This is among the first studies to quantify Ca/Al molar ratios for stemflow. Ca/Al molar ratios in bulk precipitation, throughfall, stemflow, litter leachate, near-trunk soil solution, and soil water were quantified for a deciduous forest in northeastern MD, USA. Data were collected over a 3-year period. The Ca/Al molar ratios in this study were above the threshold for aluminum stress (<1). Fagus grandifolia Ehrh. (American beech) had a median annual stemflow Ca/Al molar ratio of 15.7, with the leafed and leafless values of 12.4 and 19.2, respectively. The corresponding Ca/Al molar ratios for Liriodendron tulipifera L. (yellow poplar) were 11.9 at the annual time scale and 11.9 and 13.6 for leafed and leafless periods, respectively. Bayesian statistical analysis showed no significant effect of canopy state (leafed, leafless) on Ca/Al molar ratios. DOC was consistently an important predictor of calcium, aluminum, and Ca/Al ratios. pH was occasionally an important predictor of calcium and aluminum concentrations, but was not a good predictor of Ca/Al ratio in any of the best-fit models (of >500 examined). This study supplies new data on Ca/Al molar ratios for stemflow from two common deciduous tree species. Future work should examine Ca/Al molar ratios in stemflow of other species and examine both inorganic and organic aluminum species to better gauge the potential for, and understand the dynamics of, aluminum toxicity in the proximal area around tree boles.

  20. Abnormal secretion and function of recombinant human factor VII as the result of modification to a calcium binding site caused by a 15-base pair insertion in the F7 gene.

    PubMed

    Peyvandi, F; Carew, J A; Perry, D J; Hunault, M; Khanduri, U; Perkins, S J; Mannucci, P M; Bauer, K A

    2001-02-15

    A case of a novel mutation in the F7 gene that results in factor VII coagulant activity (VII:c) of less than 1% and VII antigen (VII:Ag) levels of 10% is presented. DNA analysis revealed a homozygous 15-base pair (bp) in-frame insertion-type mutation at nucleotide 10554. This insertion consisted of a duplication of residues leucine (L)213 to aspartic acid (D)217 (leucine, serine, glutamic acid, histidine, and aspartic acid), probably arising by slipped mispairing between 2 copies of a direct repeat (GCGAGCACGAC) separated by 4 bp. Molecular graphic analyses showed that the insertion is located at the surface of the catalytic domain in an exposed loop stabilized by extensive salt-bridge and hydrogen bond formation at which the calcium binding site is located. The mutation probably interferes with protein folding during VII biosynthesis and/or diminishes functional activity through the loss of calcium binding. In vitro expression studies demonstrated that the levels of VII:Ag in lysates of cells transfected with wild type VII (VIIWT) were equivalent to those with mutant type VII (VIIMT), but the level of secreted VIIMT was 5% to 10% that of VIIWT. Pulse chase studies demonstrated that VIIMT did not accumulate intracellularly, and studies with inhibitors of protein degradation showed that recombinant VIIMT was partially degraded in the pre-Golgi compartment. Accordingly, only small amounts of VIIMT with undetectable procoagulant activity were secreted into conditioned media. These results demonstrate that a combination of secretion and functional defects is the mechanism whereby this insertion causes VII deficiency.

  1. Calcium homeostasis in diabetes mellitus.

    PubMed

    Heath, H; Lambert, P W; Service, F J; Arnaud, S B

    1979-09-01

    Experimentally diabetic rats have low serum 1,25-dihydroxyvitamin D, intestinal malabsorption of calcium, secondary hyperparathyroidism, and bone loss. To examine the hypothesis that abnormalities similar to those in the diabetic rat might explain human diabetic osteopenia, we studied calcium metabolism in 40 healthy control and 82 diabetic patients aged 18--75 yr [47 untreated: fasting plasma glucose (mean +/- SE), 267 +/- 8 mg/dl; 19 treated but hyperglycemic: glucose 305 +/- 24 mg/dl; 16 treated and in better control: glucose, 146 +/- 8 mg/dl]. Serum total calcium, ionic calcium, immunoreactive parathyroid hormone (Arnaud method, GP-1M and CH-12M antisera), 25-hydroxyvitamin D (Haddad method), and 1,25-dihydroxyvitamin D (Lambert method) concentrations were normal in all 3 groups of diabetics and were not significantly different from values in the control group. We determined absorption of calcium from the intestine by a double isotope method (100 mg Ca carrier; normal range, 40--80%) in 11 control and 13 untreated, uncontrolled diabetics (mean plasma glucose, 285 +/- 17 mg/dl). Absorption of calcium in controls was 60 +/- 3% and in diabetics was 56 +/- 3% (not significantly different). We have found no derangement of calcium metabolism in adults with insulin-requiring juvenile- and adult-onset diabetes regardless of treatment status. The experimental diabetic rat model does not appear to be useful for determining the pathogenesis of adult human diabetic osteopenia.

  2. Impermeant Solutes and Cellular Calcium Metabolism in Pathogenesis of Acute Renal Failure.

    DTIC Science & Technology

    and nifedipine will, on the other hand, accomplish similar effects: reducing vascular and golmerular abnormalities by minimizing calcium influx induced...maneuvers. Keywords: Dogs/rats mitochondria; ATP; Norepinephrine; Calcium; Verapamil; Nifedipine ; Mannitol; Kidney diseases; Kidney failure.

  3. Calcium - ionized

    MedlinePlus

    ... 245. Read More Acute kidney failure Albumin - blood (serum) test Bone tumor Calcium blood test Hyperparathyroidism Hypoparathyroidism Malabsorption Milk-alkali syndrome Multiple myeloma Osteomalacia Paget disease of the bone Rickets Sarcoidosis Vitamin D Review ...

  4. Calcium - urine

    MedlinePlus

    ... Monitor someone who has a problem with the parathyroid gland , which helps control calcium levels in the blood ... much production of parathyroid hormone (PTH) by the parathyroid glands in the neck (hyperparathyroidism) Use of loop diuretics ...

  5. Calcium Carbonate.

    PubMed

    Al Omari, M M H; Rashid, I S; Qinna, N A; Jaber, A M; Badwan, A A

    2016-01-01

    Calcium carbonate is a chemical compound with the formula CaCO3 formed by three main elements: carbon, oxygen, and calcium. It is a common substance found in rocks in all parts of the world (most notably as limestone), and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. CaCO3 exists in different polymorphs, each with specific stability that depends on a diversity of variables. © 2016 Elsevier Inc. All rights reserved.

  6. Calcium orthophosphates

    PubMed Central

    Dorozhkin, Sergey V.

    2011-01-01

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

  7. Calcium Hydroxylapatite

    PubMed Central

    Yutskovskaya, Yana Alexandrovna; Philip Werschler, WM.

    2015-01-01

    Background: Calcium hydroxylapatite is one of the most well-studied dermal fillers worldwide and has been extensively used for the correction of moderate-to-severe facial lines and folds and to replenish lost volume. Objectives: To mark the milestone of 10 years of use in the aesthetic field, this review will consider the evolution of calcium hydroxylapatite in aesthetic medicine, provide a detailed injection protocol for a global facial approach, and examine how the unique properties of calcium hydroxylapatite provide it with an important place in today’s market. Methods: This article is an up-to-date review of calcium hydroxylapatite in aesthetic medicine along with procedures for its use, including a detailed injection protocol for a global facial approach by three expert injectors. Conclusion: Calcium hydroxylapatite is a very effective agent for many areas of facial soft tissue augmentation and is associated with a high and well-established safety profile. Calcium hydroxylapatite combines high elasticity and viscosity with an ability to induce long-term collagen formation making it an ideal agent for a global facial approach. PMID:25610523

  8. Trace element abnormalities in chronic uremia

    SciTech Connect

    Smythe, W.R.; Alfrey, A.C.; Craswell, P.W.; Crouch, C.A.; Ibels, L.S.; Kubo, H.; Nunnelley, L.L.; Rudolph, H.

    1982-03-01

    We studied the elemental composition of autopsy tissue samples to characterize the trace element changes induced in various human tissues by uremia. Samples from the United States and Australia, including those from 120 uremic patients who had been on dialysis, and 64 control subjects, were analyzed by x-ray fluorescence. Tissues analyzed were aorta, bone, brain, heart, kidney, liver, lung, muscle, and spleen; elements measured included potassium, calcium, iron, copper, zinc, selenium, bromine, rubidium, strontium, molybdenum, cadmium, tin, and uranium. Uremic abnormalities that were statistically very significant were found, including increases of calcium, strontium, molybdenum, cadmium, and tin and decreases of potassium and rubidium. The distributions of iron, copper, and zinc are altered. We conclude that these abnormalities are primarily the result of the uremia and that, generally, they are neither greatly moderated nor exacerbated by the dialysis procedure.

  9. Abnormal Head Position

    MedlinePlus

    ... an ocular cause. Can a longstanding head turn lead to any permanent problems? Yes, a significant abnormal ... cause permanent tightening of neck muscles that can lead to chronic neck ache or headache. An abnormal ...

  10. Skeletal limb abnormalities

    MedlinePlus

    ... medlineplus.gov/ency/article/003170.htm Skeletal limb abnormalities To use the sharing features on this page, please enable JavaScript. Skeletal limb abnormalities refers to a variety of bone structure problems ...

  11. Tooth - abnormal colors

    MedlinePlus

    ... medlineplus.gov/ency/article/003065.htm Tooth - abnormal colors To use the sharing features on this page, please enable JavaScript. Abnormal tooth color is any color other than white to yellowish- ...

  12. Urine - abnormal color

    MedlinePlus

    ... medlineplus.gov/ency/article/003139.htm Urine - abnormal color To use the sharing features on this page, please enable JavaScript. The usual color of urine is straw-yellow. Abnormally colored urine ...

  13. Calcium and Calcium Supplements: Achieving the Right Balance

    MedlinePlus

    ... calcium. Common calcium supplements may be labeled as: Calcium carbonate (40 percent elemental calcium) Calcium citrate (21 percent ... forms of calcium supplements are carbonate and citrate. Calcium carbonate is cheapest and therefore often a good first ...

  14. Calcium biogeochemical cycle at the beech tree-soil solution interface from the Strengbach CZO (NE France): insights from stable Ca and radiogenic Sr isotopes

    NASA Astrophysics Data System (ADS)

    Schmitt, Anne-Désirée; Gangloff, Sophie; Labolle, François; Chabaux, François; Stille, Peter

    2017-09-01

    Calcium (Ca) is the fourth most abundant element in mineral nutrition and plays key physiological and structural roles in plant metabolism. At the soil-water-plant scale, stable Ca isotopes are a powerful tool for the identification of plant-mineral interactions and recycling via vegetation. Radiogenic Sr isotopes are often used as tracers of Ca sources and mixtures of different reservoirs. In this study, stable Ca and radiogenic Sr are combined and analysed in several organs from two beech trees that were collected in June and September in the Strengbach critical zone observatory (CZO) (NE France) and in corresponding soil solutions. At the beech-tree scale, this study confirms the field Ca adsorption (i.e., physico-chemical mechanism and not vital effects) on carboxyl acid groups of pectin in the apoplasm of small roots. The analysis of the xylem sap and corresponding organs shows that although the Strengbach CZO is nutrient-poor, Ca seems to be non-limiting for tree-growth. Different viscosities of xylem sap between the stemwood and branches or leaves can explain δ44/40Ca values in different tree-organs. The bark and phloem 40Ca-enrichments could be due to Ca-oxalate precipitation in the bark tissues and in the phloem. The results from this study regarding the combination of these two isotopic systems show that the isotopic signatures of the roots are dominated by Ca fractionation mechanisms and Sr, and thus Ca, source variations. In contrast, translocation mechanisms are only governed by Ca fractionation processes. This study showed that at the root-soil solution interface, litter degradation was not the main source of Ca and Sr and that the soil solutions are not the complement of uptake by roots for samples from the 2011/2013 period. The opposite is observed for older samples. These observations indicate the decreasing contribution of low radiogenic Sr fluxes, such as recycling, alimenting the soil solutions. Such reduced importance of nutrient uptake and

  15. The remodeling transient and the calcium economy.

    PubMed

    Aloia, J F; Arunabh-Talwar, S; Pollack, S; Yeh, J K

    2008-07-01

    The remodeling transient describes a change in bone mass that lasts one remodeling cycle following an intervention that disturbs the calcium economy. We demonstrated the transient in a study of the response of bone density to calcium/vitamin D3 supplementation and show the hazards of misinterpretation if the transient is not considered. The remodeling transient describes a change in bone mass that lasts for one remodeling cycle following an intervention that disturbs the calcium economy. We report an intervention with calcium and vitamin D supplementation in 208 postmenopausal African-American women where the remodeling transient was considered a priori in the study design. Both groups (calcium alone vs. calcium + 20 microg (800 IU) vitamin D3) were ensured a calcium intake in excess of 1200 mg/day. There were no differences between the two groups in changes in BMD over time. These BMD changes were therefore interpreted to reflect increased calcium intake in both groups but not any influence of vitamin D. A transient increase in bone mineral density was observed during the first year of study, followed by a decline. The remodeling period was estimated at about 9 months, which is similar to histomorphometric estimates. It is problematic to draw conclusions concerning interventions that influence the calcium economy without considering the remodeling transient in study design. Studies of agents that effect bone remodeling must be carried out for at least two remodeling cycles and appropriate techniques must be used in data analysis.

  16. Effect of the level of cholecalciferol supplementation of broiler breeder hen diets on the performance and bone abnormalities of the progeny fed diets containing various levels of calcium or 25-hydroxycholecalciferol.

    PubMed

    Atencio, A; Edwards, H M; Pesti, G M

    2005-10-01

    Four experiments were conducted using Ross x Ross chicks hatched from broiler breeder hens fed various levels of cholecalciferol (vitamin D3; 0 to 4,000 IU/kg of diet) to determine the effect of the maternal diet on the performance and leg abnormalities of the progeny. Chicks hatched from eggs laid by the hens at different ages were used in experiments 1 to 4. The studies were conducted in an ultraviolet light-free environment as split plot designs, with Ca levels or 25-hydroxycholecalciferol (25-OHD3) in the chicks' diet as the whole plot, and vitamin D3 in the maternal diet as a subplot. Chicks in experiments 1 and 2 were fed 2 levels of Ca (0.63% or 0.90%) and chicks in experiments 3 and 4 were fed 6 levels of 25-OHD3 (0 to 40 microg/kg of diet). Significant increases in body weight gain (BWG) of the progeny were observed in experiments 1, 2, and 4 as the vitamin D3 level in the maternal diet increased. Chicks hatched from eggs laid by hens fed the highest levels of D3 had the highest tibia ash. Significant reductions in Ca rickets incidence (experiments 1 and 2) and tibial dyschondroplasia (TD) incidence (experiment 1) were observed as the level of vitamin D3 in the maternal diet increased. Chicks fed lower levels of Ca had lower BWG and tibia ash and higher incidences of TD and Ca rickets than chicks fed higher levels of Ca. Increasing the level of 25-OHD3 in the chicks' diet significantly improved BWG, tibia ash, and plasma Ca and reduced TD and Ca rickets incidence. An overall evaluation of the study indicates that chicks from hens fed the highest levels of vitamin D3 and fed high levels of Ca or 25-OHD3 had the highest BWG, tibia ash, and plasma Ca, and the lowest incidences of TD and Ca rickets.

  17. Sleep Physiology, Abnormal States, and Therapeutic Interventions

    PubMed Central

    Wickboldt, Alvah T.; Bowen, Alex F.; Kaye, Aaron J.; Kaye, Adam M.; Rivera Bueno, Franklin; Kaye, Alan D.

    2012-01-01

    Sleep is essential. Unfortunately, a significant portion of the population experiences altered sleep states that often result in a multitude of health-related issues. The regulation of sleep and sleep-wake cycles is an area of intense research, and many options for treatment are available. The following review summarizes the current understanding of normal and abnormal sleep-related conditions and the available treatment options. All clinicians managing patients must recommend appropriate therapeutic interventions for abnormal sleep states. Clinicians' solid understanding of sleep physiology, abnormal sleep states, and treatments will greatly benefit patients regardless of their disease process. PMID:22778676

  18. Cause and Consequence: Mitochondrial Dysfunction Initiates and Propagates Neuronal Dysfunction, Neuronal Death and Behavioral Abnormalities in Age Associated Neurodegenerative Diseases

    PubMed Central

    Gibson, Gary E.; Starkov, Anatoly; Blass, John P.; Ratan, Rajiv R.; Beal, M. Flint

    2009-01-01

    SUMMARY Age-related neurodegenerative diseases are associated with mild impairment of oxidative metabolism and accumulation of abnormal proteins. Within the cell, the mitochondria appears to be a dominant site for initiation and propagation of disease processes. Shifts in metabolism in response to mild metabolic perturbations may decrease the threshold for irreversible injury in response to ordinarily sub lethal metabolic insults. Mild impairment of metabolism accrue from and lead to increased reactive oxygen species (ROS). Increased ROS change cell signaling via post transcriptional and transcriptional changes. The cause and consequences of mild impairment of mitochondrial metabolism is one focus of this review. Many experiments in tissues from humans support the notion that oxidative modification of the α-ketoglutarate dehydrogenase complex (KGDHC) compromises neuronal energy metabolism and enhance ROS production in Alzheimer’s Disease (AD). These data suggest that cognitive decline in AD derives from the selective tricarboxylic acid (TCA) cycle abnormalities. By contrast in Huntington’s Disease (HD), a movement disorder with cognitive features distinct form AD, complex II + III abnormalities may dominate. These distinct mitochondrial abnormalities culminate in oxidative stress, energy dysfunction, and aberrant homeostasis of cytosolic calcium. Cytosolic calcium, elevations even only transiently, leads to hyperactivity of a number of enzymes. One calcium activated enzyme with demonstrated pathophysiological import in HD and AD is transglutaminase (TGase). TGase is a cross linking enzymes that can modulate transcrption, inactivate metabolic enzymes, and cause aggregation of critical proteins. Recent data indicate that TGase can silence expression of genes involved in compensating for metabolic stress. Altogether, our results suggest that increasing KGDHC via inhibition of TGase or via a host of other strategies to be described would be effective therapeutic

  19. [Regulatory mechanism of calcium metabolism.

    PubMed

    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.

  20. Electrocardiographic abnormalities in patients with acute pancreatitis.

    PubMed

    Rubio-Tapia, Alberto; García-Leiva, Jorge; Asensio-Lafuente, Enrique; Robles-Díaz, Guillermo; Vargas-Vorácková, Florencia

    2005-10-01

    Electrocardiographic abnormalities may be associated with acute pancreatitis (AP). To describe the electrocardiographic disturbances present in patients with AP and to assess differences in electrolyte and pancreatic enzyme levels among patients with and without these abnormalities. Fifty-one consecutive patients with AP and without preexisting heart disease underwent a standard 12-lead electrocardiogram (EKG) and a serum electrolyte profile. EKG abnormalities were summarized in terms of frequencies, means, and standard deviations. Electrolyte and enzyme levels were summarized as medians. Differences were analyzed using the Mann-Whitney U test. Twenty-eight patients (55%) had an abnormal EKG. Nonspecific changes of repolarization (20%), sinus tachycardia (12%), and left anterior hemiblock (10%) were the most frequent disturbances. Patients with sinus tachycardia had lower levels of phosphorus (2.3 vs. 3.4 mEq/L, P < 0.004) and calcium (8.4 vs. 9.1 mg/dL, P < 0.02). A tendency to higher levels of potassium and lower levels of phosphorus was found in patients with sinus tachycardia and nonspecific changes of repolarization, respectively. No differences were found in amylase, pancreatic amylase, or lipase among patients with normal and abnormal EKG. More than 50% of the patients with AP had EKG abnormalities, and these changes could be related to electrolyte alterations.

  1. Calcium cyanide

    Integrated Risk Information System (IRIS)

    Jump to main content . Integrated Risk Information System Recent Additions | Contact Us Search : All EPA IRIS • You are here : EPA Home • Research • Environmental Assessment • IRIS • IRIS Summaries Redirect Page As of September 28 , 2010 , the assessment summary for calcium cyanide is included in th

  2. Role of calcium and vitamin D in the treatment of muscle pain

    PubMed Central

    Liang, Raymond CR

    1985-01-01

    Calcium and vitamin D deficiencies are associated with abnormal muscular functions including non-specific pain and weakness. A diet survey of a patient complaining of back pain showed a low calcium intake. Clinically patients may have low utilization of dietary calcium. In addition to the normal chiropractic treatments, the patient was given calcium and vitamin D supplements. These supplements greatly improved the recovery of the patient. The nutritional status of calcium and vitamin D in the general Canadian population is discussed.

  3. Regulation of cardiomyocyte autophagy by calcium.

    PubMed

    Shaikh, Soni; Troncoso, Rodrigo; Criollo, Alfredo; Bravo-Sagua, Roberto; García, Lorena; Morselli, Eugenia; Cifuentes, Mariana; Quest, Andrew F G; Hill, Joseph A; Lavandero, Sergio

    2016-04-15

    Calcium signaling plays a crucial role in a multitude of events within the cardiomyocyte, including cell cycle control, growth, apoptosis, and autophagy. With respect to calcium-dependent regulation of autophagy, ion channels and exchangers, receptors, and intracellular mediators play fundamental roles. In this review, we discuss calcium-dependent regulation of cardiomyocyte autophagy, a lysosomal mechanism that is often cytoprotective, serving to defend against disease-related stress and nutrient insufficiency. We also highlight the importance of the subcellular distribution of calcium and related proteins, interorganelle communication, and other key signaling events that govern cardiomyocyte autophagy.

  4. Tamm-Horsfall glycoprotein and calcium nephrolithiasis.

    PubMed

    Hess, B

    1994-01-01

    Available data on the effects of Tamm-Horsfall glycoprotein (THP) on calcium oxalate crystallization processes are apparently conflicting. With the main emphasis on calcium oxalate crystal aggregation, this review demonstrates that THP has a dual role as a modifier of crystal aggregation: in solutions with high pH, low ionic strength (IS) and low concentrations of calcium and THP itself, the glycoprotein acts as a powerful inhibitor of calcium oxalate crystal aggregation. Conversely, low pH, high IS and high concentrations of calcium and THP all favor self-aggregation of THP molecules which lowers their inhibitory activity against calcium oxalate crystal aggregation. Some patients with severely recurrent Ca stone disease excrete abnormal THPs which self-aggregate at levels of pH, IS and concentrations of Ca and THP at which normal THPs remain in monomeric form. With high Ca concentrations, such abnormal THPs become strong promoters of crystal aggregation, since conformational changes in crystal-bound THP molecules induce strong viscous binding forces which overcome repulsive electrostatic surface charges. By chelating free Ca ions, citrate reduces self-aggregation of THP molecules and turns promoting THPs into inhibitors of calcium oxalate crystal aggregation.

  5. Structurally abnormal human autosomes

    SciTech Connect

    1993-12-31

    Chapter 25, discusses structurally abnormal human autosomes. This discussion includes: structurally abnormal chromosomes, chromosomal polymorphisms, pericentric inversions, paracentric inversions, deletions or partial monosomies, cri du chat (cat cry) syndrome, ring chromosomes, insertions, duplication or pure partial trisomy and mosaicism. 71 refs., 8 figs.

  6. Calcium and bone disease

    PubMed Central

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

    2013-01-01

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

  7. Morphological abnormalities among lampreys

    USGS Publications Warehouse

    Manion, Patrick J.

    1967-01-01

    The experimental control of the sea lamprey (Petromyzon marinus) in the Great Lakes has required the collection of thousands of lampreys. Representatives of each life stage of the four species of the Lake Superior basin were examined for structural abnormalities. The most common aberration was the presence of additional tails. The accessory tails were always postanal and smaller than the normal tail. The point of origin varied; the extra tails occurred on dorsal, ventral, or lateral surfaces. Some of the extra tails were misshaped and curled, but others were normal in shape and pigment pattern. Other abnormalities in larval sea lampreys were malformed or twisted tails and bodies. The cause of the structural abnormalities is unknown. The presence of extra caudal fins could be genetically controlled, or be due to partial amputation or injury followed by abnormal regeneration. Few if any lampreys with structural abnormalities live to sexual maturity.

  8. Abnormal rubbing and keratectasia.

    PubMed

    McMonnies, Charles W

    2007-11-01

    Hypotheses for the varied pathogenesis of the different forms of keratoconus have been outlined. Against this background, the possibility that abnormal rubbing causes or contributes to the development or progression of some forms of keratoconus has been examined. Circumstantial evidence that shows an association between abnormal rubbing and keratoconus is reviewed, and a wide range of different forms of abnormal rubbing is described. Also examined is evidence of several processes whereby the cornea appears to be, or could be, adversely affected by mechanical trauma caused by rubbing. Conditions that may increase susceptibility to mechanical rubbing trauma have been discussed. Evidence of a role for inflammatory mediators in the pathogenesis of keratoconus appears to void the description of keratoconus as a noninflammatory condition. When vigorous knuckle-rubbing forces are located on the normal peripheral cornea, the thinner or weakened cone apex may be exposed to high intraocular pressure distending forces that may tend to promote ectasia. It appears reasonable to conclude that abnormal rubbing is a cause of some types of keratoconus, not because all abnormal rubbing, or only abnormal rubbing, leads to the development of some types of keratoconus, but because abnormal rubbing may increase the likelihood of the development of some forms of keratoconus. Abnormal rubbing habits may commence or continue after routine contact lens wear is established. Any associated rubbing or contact lens trauma may contribute to the progression of keratoconus. The abnormal rubbing-ectasia association in keratoconus may extend to other forms of keratectasia, including that seen after laser in situ keratomileusis, for which a contributory abnormal rubbing hypothesis may be appropriate.

  9. Calcium and Vitamin D

    USDA-ARS?s Scientific Manuscript database

    Calcium is required for the bone formation phase of bone remodeling. Typically about 5 nmol (200 mg) of calcium is removed from the adult skeleton and replaced each day. To supply this amount, one would need to consume about 600 mg of calcium, since calcium is not very efficiently absorbed. Calcium ...

  10. Calcium metabolism in sarcoidosis

    PubMed Central

    Dent, C. E.

    1970-01-01

    Fifteen patients with hypercalcaemia and sarcoidosis have been studied. Twelve were males of average age 34; the three females averaged 53. Cases included widely varying sarcoid manifestations, but five gave a clear history of rather excessive ingestion of low-dosage vitamin D preparations. The data confirm that in most cases there is an undue sensitivity to all the actions of vitamin D, the situation therefore mimicking vitamin D intoxication. Two patients volunteered to receive ultra-violet irradiation and became hypercalcaemic with corresponding clinical and biochemical changes. Steroids make normal the calcium abnormalities just as they do in straight vitamin D intoxication. However, in three further patients the hypercalcaemia did not respond to steroids and was shown to be due to the presence of an over-acting parathyroid gland, removal of which corrected the abnormality. There are a sufficient number of other similar cases in the literature to suggest that the development of parathyroid adenomas is another even rarer complication of sarcoidosis which must be carefully distinguished from vitamin D sensitivity. PMID:5481094

  11. Abnormal menstrual periods (image)

    MedlinePlus

    ... have a variety of causes, such as endometrial hyperplasia, endometrial polyps, uterine fibroids, and abnormal thyroid or ... endometrium becomes unusually thick it is called endometrial hyperplasia. Hyperplasia may cause profuse or extended menstrual bleeding.

  12. Abnormal haemoglobins: detection & characterization

    PubMed Central

    Wajcman, Henri; Moradkhani, Kamran

    2011-01-01

    Haemoglobin (Hb) abnormalities though quite frequent, are generally detected in populations during surveys and programmes run for prevention of Hb disorders. Several methods are now available for detection of Hb abnormalities. In this review, the following are discussed: (i) the methods used for characterization of haemoglobin disorders; (ii) the problems linked to diagnosis of thalassaemic trait; (iii) the strategy for detection of common Hb variants; and (iv) the difficulties in identification of rare variants. The differences between developing and industrialized countries for the strategies employed in the diagnosis of abnormal haemoglobins are considered. We mention the limits and pitfalls for each approach and the necessity to characterize the abnormalities using at least two different methods. The recommended strategy is to use a combination of cation-exchange high performance chromatography (CE-HPLC), capillary electrophoresis (CE) and when possible isoelectric focusing (IEF). Difficult cases may demand further investigations requiring specialized protein and/or molecular biology techniques. PMID:22089618

  13. "Jeopardy" in Abnormal Psychology.

    ERIC Educational Resources Information Center

    Keutzer, Carolin S.

    1993-01-01

    Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

  14. "Jeopardy" in Abnormal Psychology.

    ERIC Educational Resources Information Center

    Keutzer, Carolin S.

    1993-01-01

    Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

  15. Muscle tone abnormalities.

    PubMed

    Habel, M

    1997-01-01

    Rehabilitation nurses frequently encounter clients with neurological disorders that adversely affect muscle tone. By understanding the physiological etiology of abnormal muscle tone, individual practitioners can design nursing interventions for various care settings that appropriately protect clients from injury and that can help clients and caregivers learn effective techniques for managing muscle tone problems. This article explains muscle tone abnormalities in detail and offers insight into how rehabilitation nurses can play a key role in managing clients' alterations in muscle tone.

  16. The Function of the Mitochondrial Calcium Uniporter in Neurodegenerative Disorders

    PubMed Central

    Liao, Yajin; Dong, Yuan; Cheng, Jinbo

    2017-01-01

    The mitochondrial calcium uniporter (MCU)—a calcium uniporter on the inner membrane of mitochondria—controls the mitochondrial calcium uptake in normal and abnormal situations. Mitochondrial calcium is essential for the production of adenosine triphosphate (ATP); however, excessive calcium will induce mitochondrial dysfunction. Calcium homeostasis disruption and mitochondrial dysfunction is observed in many neurodegenerative disorders. However, the role and regulatory mechanism of the MCU in the development of these diseases are obscure. In this review, we summarize the role of the MCU in controlling oxidative stress-elevated mitochondrial calcium and its function in neurodegenerative disorders. Inhibition of the MCU signaling pathway might be a new target for the treatment of neurodegenerative disorders. PMID:28208618

  17. Calcium and Vitamin D

    MedlinePlus

    ... A calcium-rich diet (including dairy, nuts, leafy greens and fish) helps to build and protect your ... yogurt and cheese are high in calcium. Certain green vegetables and other foods contain calcium in smaller ...

  18. SECONDARY HYPERPARATHYROIDISM AFTER BARIATRIC SURGERY: TREATMENT IS WITH CALCIUM CARBONATE OR CALCIUM CITRATE?

    PubMed Central

    BARETTA, Giorgio Alfredo Pedroso; CAMBI, Maria Paula Carlini; RODRIGUES, Arieli Luz; MENDES, Silvana Aparecida

    2015-01-01

    Background : Bariatric surgery, especially Roux-en-Y gastric bypass, can cause serious nutritional complications arising from poor absorption of essential nutrients. Secondary hyperparathyroidism is one such complications that leads to increased parathyroid hormone levels due to a decrease in calcium and vitamin D, which may compromise bone health. Aim : To compare calcium carbonate and calcium citrate in the treatment of secondary hyperparathyroidism. Method : Patients were selected on the basis of their abnormal biochemical test and treatment was randomly done with citrate or calcium carbonate. Results : After 60 days of supplementation, biochemical tests were repeated, showing improvement in both groups. Conclusion : Supplementation with calcium (citrate or carbonate) and vitamin D is recommended after surgery for prevention of secondary hyperparathyroidism. PMID:26537273

  19. SECONDARY HYPERPARATHYROIDISM AFTER BARIATRIC SURGERY: TREATMENT IS WITH CALCIUM CARBONATE OR CALCIUM CITRATE?

    PubMed

    Baretta, Giorgio Alfredo Pedroso; Cambi, Maria Paula Carlini; Rodrigues, Arieli Luz; Mendes, Silvana Aparecida

    2015-01-01

    Bariatric surgery, especially Roux-en-Y gastric bypass, can cause serious nutritional complications arising from poor absorption of essential nutrients. Secondary hyperparathyroidism is one such complications that leads to increased parathyroid hormone levels due to a decrease in calcium and vitamin D, which may compromise bone health. To compare calcium carbonate and calcium citrate in the treatment of secondary hyperparathyroidism. Patients were selected on the basis of their abnormal biochemical test and treatment was randomly done with citrate or calcium carbonate. After 60 days of supplementation, biochemical tests were repeated, showing improvement in both groups. Supplementation with calcium (citrate or carbonate) and vitamin D is recommended after surgery for prevention of secondary hyperparathyroidism.

  20. Interactions of Mitochondria/Metabolism and Calcium Regulation in Alzheimer's Disease: A Calcinist Point of View.

    PubMed

    Gibson, Gary E; Thakkar, Ankita

    2017-02-08

    Decades of research suggest that alterations in calcium are central to the pathophysiology of Alzheimer's Disease (AD). Highly reproducible changes in calcium dynamics occur in cells from patients with both genetic and non-genetic forms of AD relative to controls. The most robust change is an exaggerated release of calcium from internal stores. Detailed analysis of these changes in animal and cell models of the AD-causing presenilin mutations reveal robust changes in ryanodine receptors, inositol tris-phosphate receptors, calcium leak channels and store activated calcium entry. Similar anomalies in calcium result when AD-like changes in mitochondrial enzymes or oxidative stress are induced experimentally. The calcium abnormalities can be directly linked to the altered tau phosphorylation, amyloid precursor protein processing and synaptic dysfunction that are defining features of AD. A better understanding of these changes is required before using calcium abnormalities as therapeutic targets.

  1. Calcitonin control of calcium metabolism during weightlessness

    NASA Technical Reports Server (NTRS)

    Soliman, Karam F. A.

    1993-01-01

    The main objective of this proposal is to elucidate calcitonin role in calcium homeostasis during weightlessness. In this investigation our objectives are to study: the effect of weightlessness on thyroid and serum calcitonin, the effect of weightlessness on the circadian variation of calcitonin in serum and the thyroid gland, the role of light as zeitgeber for calcitonin circadian rhythm, the circadian pattern of thyroid sensitivity to release calcitonin in response to calcium load, and the role of serotonin and norepinephrine in the control of calcitonin release. The main objective of this research/proposal is to establish the role of calcitonin in calcium metabolism during weightlessness condition. Understanding the mechanism of these abnormalities will help in developing therapeutic means to counter calcium imbalance in spaceflights.

  2. Cause and consequence: mitochondrial dysfunction initiates and propagates neuronal dysfunction, neuronal death and behavioral abnormalities in age-associated neurodegenerative diseases.

    PubMed

    Gibson, Gary E; Starkov, Anatoly; Blass, John P; Ratan, Rajiv R; Beal, M Flint

    2010-01-01

    Age-related neurodegenerative diseases are associated with mild impairment of oxidative metabolism and accumulation of abnormal proteins. Within the cell, the mitochondria appears to be a dominant site for initiation and propagation of disease processes. Shifts in metabolism in response to mild metabolic perturbations may decrease the threshold for irreversible injury in response to ordinarily sublethal metabolic insults. Mild impairment of metabolism accrue from and lead to increased reactive oxygen species (ROS). Increased ROS change cell signaling via post-transcriptional and transcriptional changes. The cause and consequences of mild impairment of mitochondrial metabolism is one focus of this review. Many experiments in tissues from humans support the notion that oxidative modification of the alpha-ketoglutarate dehydrogenase complex (KGDHC) compromises neuronal energy metabolism and enhances ROS production in Alzheimer's Disease (AD). These data suggest that cognitive decline in AD derives from the selective tricarboxylic acid (TCA) cycle abnormalities. By contrast in Huntington's Disease (HD), a movement disorder with cognitive features distinct form AD, complex II+III abnormalities may dominate. These distinct mitochondrial abnormalities culminate in oxidative stress, energy dysfunction, and aberrant homeostasis of cytosolic calcium. Cytosolic calcium, elevations even only transiently, leads to hyperactivity of a number of enzymes. One calcium-activated enzyme with demonstrated pathophysiological import in HD and AD is transglutaminase (TGase). TGase is a crosslinking enzymes that can modulate transcription, inactivate metabolic enzymes, and cause aggregation of critical proteins. Recent data indicate that TGase can silence expression of genes involved in compensating for metabolic stress. Altogether, our results suggest that increasing KGDHC via inhibition of TGase or via a host of other strategies to be described would be effective therapeutic approaches

  3. Altered sarcoplasmic reticulum calcium cycling—targets for heart failure therapy

    PubMed Central

    Kho, Changwon; Lee, Ahyoung; Hajjar, Roger J.

    2013-01-01

    Cardiac myocyte function is dependent on the synchronized movements of Ca2+ into and out of the cell, as well as between the cytosol and sarcoplasmic reticulum. These movements determine cardiac rhythm and regulate excitation–contraction coupling. Ca2+ cycling is mediated by a number of critical Ca2+-handling proteins and transporters, such as L-type Ca2+ channels (LTCCs) and sodium/calcium exchangers in the sarcolemma, and sarcoplasmic/endoplasmic reticulum calcium ATPase 2a (SERCA2a), ryanodine receptors, and cardiac phospholamban in the sarcoplasmic reticulum. The entry of Ca2+ into the cytosol through LTCCs activates the release of Ca2+ from the sarcoplasmic reticulum through ryanodine receptor channels and initiates myocyte contraction, whereas SERCA2a and cardiac phospholamban have a key role in sarcoplasmic reticulum Ca2+ sequesteration and myocyte relaxation. Excitation–contraction coupling is regulated by phosphorylation of Ca2+-handling proteins. Abnormalities in sarcoplasmic reticulum Ca2+ cycling are hallmarks of heart failure and contribute to the pathophysiology and progression of this disease. Correcting impaired intracellular Ca2+ cycling is a promising new approach for the treatment of heart failure. Novel therapeutic strategies that enhance myocyte Ca2+ homeostasis could prevent and reverse adverse cardiac remodeling and improve clinical outcomes in patients with heart failure. PMID:23090087

  4. Abnormal folate metabolism in foetuses affected by neural tube defects.

    PubMed

    Dunlevy, Louisa P E; Chitty, Lyn S; Burren, Katie A; Doudney, Kit; Stojilkovic-Mikic, Taita; Stanier, Philip; Scott, Rosemary; Copp, Andrew J; Greene, Nicholas D E

    2007-04-01

    Folic acid supplementation can prevent many cases of neural tube defects (NTDs), whereas suboptimal maternal folate status is a risk factor, suggesting that folate metabolism is a key determinant of susceptibility to NTDs. Despite extensive genetic analysis of folate cycle enzymes, and quantification of metabolites in maternal blood, neither the protective mechanism nor the relationship between maternal folate status and susceptibility are understood in most cases. In order to investigate potential abnormalities in folate metabolism in the embryo itself, we derived primary fibroblastic cell lines from foetuses affected by NTDs and subjected them to the dU suppression test, a sensitive metabolic test of folate metabolism. Significantly, a subset of NTD cases exhibited low scores in this test, indicative of abnormalities in folate cycling that may be causally linked to the defect. Susceptibility to NTDs may be increased by suppression of the methylation cycle, which is interlinked with the folate cycle. However, reduced efficacy in the dU suppression test was not associated with altered abundance of the methylation cycle intermediates, s-adenosylmethionine and s-adenosylhomocysteine, suggesting that a methylation cycle defect is unlikely to be responsible for the observed abnormality of folate metabolism. Genotyping of samples for known polymorphisms in genes encoding folate-associated enzymes did not reveal any correlation between specific genotypes and the observed abnormalities in folate metabolism. These data suggest that as yet unrecognized genetic variants result in embryonic abnormalities of folate cycling that may be causally related to NTDs.

  5. Calcium Oxalate Biomineralization by Piloderma fallax in Response to Various Levels of Calcium and Phosphorus▿

    PubMed Central

    Tuason, Melissa Marie S.; Arocena, Joselito M.

    2009-01-01

    Piloderma fallax is an ectomycorrhizal fungus commonly associated with several conifer and hardwood species. We examined the formation of calcium oxalate crystals by P. fallax in response to calcium (0.0, 0.1, 0.5, 1, and 5 mM) and phosphorus (0.1 and 6 mM) additions in modified Melin-Norkrans agar medium. Both calcium and phosphorus supplementation significantly affected the amount of calcium oxalate formed. More calcium oxalate was formed at high P levels. Concentrations of soluble oxalate in the fungus and medium were higher at low P levels. There was a strong positive linear relationship between Ca level and calcium oxalate but only under conditions of phosphorus limitation. Calcium oxalate crystals were identified as the monohydrate form (calcium oxalate monohydrate [COM] whewellite) by X-ray diffraction analysis. Prismatic, styloid, and raphide forms of the crystals, characteristic COM, were observed on the surface of fungal hyphae by scanning electron microscopy. P. fallax may be capable of dissolving hyphal calcium oxalate under conditions of limited Ca. The biomineralization of calcium oxalate by fungi may be an important step in the translocation and cycling of Ca and P in soil. PMID:19783744

  6. Calcium and Calcium-Base Alloys

    DTIC Science & Technology

    1949-01-01

    alloys have •been made in electrical contacts. Little is known of’ the high - calcium alloys,» The aluminum-calcium diagram from Hansen^1) is shown in...list is still incom- plete« No use has been suggested for high calcium -aluminum alloys, ..•Arsenic-pal’c-iüm- Alloys •K.. Calcium arsenide, OajAsg...hot CaCUy, by X-ray determination of the structure. The probability of finding a useful high - calcium alloy in this system is based-on-the-validity

  7. Evidence for altered renal tubule function in idiopathic calcium stone formers

    PubMed Central

    Worcester, Elaine M.; Coe, Fredric L.

    2013-01-01

    Patients who form calcium kidney stones often have metabolic disorders such as idiopathic hypercalciuria (IH) that reflect abnormalities in mineral handling in the kidney. Renal handling of calcium is altered by ingestion of nutrients such as carbohydrates, protein, and sodium, and patients with IH appear to be more sensitive to these stimuli. Studies using probes such as diuretics or lithium clearance have the ability to clarify which nephron segments are involved in the altered renal calcium transport with nutrient seen in IH. Studies in the genetic hypercalciuric rat demonstrate alterations in both proximal tubule and thick ascending limb calcium reabsorption. Similar studies in humans have begun to provide evidence about the corresponding abnormalities in stone formers with IH. A pattern of altered renal tubule transport in calcium stone formers is suggested by the frequency of such findings as decreased tubular maximal reabsorption of phosphate and abnormal urine acidification as well as hypercalciuria in such patients, not explained by monogenic transport abnormalities. PMID:20632168

  8. Abnormalities of gonadal differentiation.

    PubMed

    Berkovitz, G D; Seeherunvong, T

    1998-04-01

    Gonadal differentiation involves a complex interplay of developmental pathways. The sex determining region Y (SRY) gene plays a key role in testis determination, but its interaction with other genes is less well understood. Abnormalities of gonadal differentiation result in a range of clinical problems. 46,XY complete gonadal dysgenesis is defined by an absence of testis determination. Subjects have female external genitalia and come to clinical attention because of delayed puberty. Individuals with 46,XY partial gonadal dysgenesis usually present in the newborn period for the valuation of ambiguous genitalia. Gonadal histology always shows an abnormality of seminiferous tubule formation. A diagnosis of 46,XY true hermaphroditism is made if the gonads contain well-formed testicular and ovarian elements. Despite the pivotal role of the SRY gene in testis development, mutations of SRY are unusual in subjects with a 46,XY karyotype and abnormal gonadal development. 46,XX maleness is defined by testis determination in an individual with a 46,XX karyotype. Most affected individuals have a phenotype similar to that of Klinefelter syndrome. In contrast, subjects with 46,XX true hermaphroditism usually present with ambiguous genitalia. The majority of subjects with 46,XX maleness have Y sequences including SRY in genomic DNA. However, only rare subjects with 46,XX true hermaphroditism have translocated sequences encoding SRY. Mosaicism and chimaerism involving the Y chromosome can also be associated with abnormal gonadal development. However, the vast majority of subjects with 45,X/46,XY mosaicism have normal testes and normal male external genitalia.

  9. [The relativity of abnormity].

    PubMed

    Nilson, Annika

    2006-01-01

    In the late 19th century and in the beginning of the 20th century, mental diseases and abnormal behavior was considered to be a great danger to culture and society. "Degeneration" was the buzzword of the time, used and misused by artists and scientists alike. At the same time, some scientists saw abnormity as the key to unlock the mysteries of the ordinary mind. Naturalistic curiosity left Pandoras box open when religion declined in Darwins wake. Two swedish scientists, the physician Bror Gadelius (1862-1938) and his friend the philosopher Axel Herrlin (1870-1937), inspired by the French psychologist Theodule Ribots (1839-1916) "psychology without a soul", denied all fixed demarcation lines between abnormity and normality. All humans are natures creatures ruled by physiological laws, not ruled by God or convention. Even ordinary morality was considered to be an utterly backward explanation and guideline for complex human behavior. Different forms of therapy, not various kinds of penalties for wicked and disturbing behavior, are the now the solution for lots of people, "normal" as well as "abnormal". Psychiatry is expanding.

  10. Biochemical abnormalities in Pearson syndrome.

    PubMed

    Crippa, Beatrice Letizia; Leon, Eyby; Calhoun, Amy; Lowichik, Amy; Pasquali, Marzia; Longo, Nicola

    2015-03-01

    Pearson marrow-pancreas syndrome is a multisystem mitochondrial disorder characterized by bone marrow failure and pancreatic insufficiency. Children who survive the severe bone marrow dysfunction in childhood develop Kearns-Sayre syndrome later in life. Here we report on four new cases with this condition and define their biochemical abnormalities. Three out of four patients presented with failure to thrive, with most of them having normal development and head size. All patients had evidence of bone marrow involvement that spontaneously improved in three out of four patients. Unique findings in our patients were acute pancreatitis (one out of four), renal Fanconi syndrome (present in all patients, but symptomatic only in one), and an unusual organic aciduria with 3-hydroxyisobutyric aciduria in one patient. Biochemical analysis indicated low levels of plasma citrulline and arginine, despite low-normal ammonia levels. Regression analysis indicated a significant correlation between each intermediate of the urea cycle and the next, except between ornithine and citrulline. This suggested that the reaction catalyzed by ornithine transcarbamylase (that converts ornithine to citrulline) might not be very efficient in patients with Pearson syndrome. In view of low-normal ammonia levels, we hypothesize that ammonia and carbamylphosphate could be diverted from the urea cycle to the synthesis of nucleotides in patients with Pearson syndrome and possibly other mitochondrial disorders.

  11. Calcium at fertilization and in early development

    PubMed Central

    Whitaker, Michael

    2012-01-01

    Fertilization calcium waves are introduced and the evidence from which we can infer general mechanisms of these waves is presented. The two main classes of hypothesis put forward to explain the generation of the fertilization calcium wave are set out and it is concluded that initiation of the fertilization calcium wave can be most generally explained in inverterbrates by a mechanism in which an activating substance enters the egg from the sperm on sperm-egg fusion, activating the egg by stimulating phospholipase C activation through a src family kinase pathway and in mammals by the diffusion of a sperm-specific phospholipase C from sperm to egg on sperm-egg fusion. The fertilization calcium wave is then set into the context of cell cycle control and the mechanism of repetitive calcium spiking in mammalian eggs is investigated. Evidence that calcium signals control cell division in early embryos is reviewed, and it is concluded that calcium signals are essential at all three stages of cell division in early embryos. Evidence that phosphoinositide signalling pathways control the resumption of meiosis during oocyte maturation is considered. It is concluded on balance that the evidence points to a need for phosphoinositide/calcium signalling during resumption of meiosis. Changes to the calcium signalling machinery occur during meiosis to enable the production of a calcium wave in the mature oocyte when it is fertilized; evidence that the shape and structure of the endoplasmic reticulum alters dynamically during maturation and after fertilization is reviewed and the link between ER dynamics and the cytoskeleton is discussed. There is evidence that calcium signalling plays a key part in the development of patterning in early embryos. Morphogenesis in ascidian, frog and zebrafish embryos is briefly described to provide the developmental context in which calcium signals act. Intracellular calcium waves that may play a role in axis formation in ascidian are discussed

  12. Imaging calcium in neurons.

    PubMed

    Grienberger, Christine; Konnerth, Arthur

    2012-03-08

    Calcium ions generate versatile intracellular signals that control key functions in all types of neurons. Imaging calcium in neurons is particularly important because calcium signals exert their highly specific functions in well-defined cellular subcompartments. In this Primer, we briefly review the general mechanisms of neuronal calcium signaling. We then introduce the calcium imaging devices, including confocal and two-photon microscopy as well as miniaturized devices that are used in freely moving animals. We provide an overview of the classical chemical fluorescent calcium indicators and of the protein-based genetically encoded calcium indicators. Using application examples, we introduce new developments in the field, such as calcium imaging in awake, behaving animals and the use of calcium imaging for mapping single spine sensory inputs in cortical neurons in vivo. We conclude by providing an outlook on the prospects of calcium imaging for the analysis of neuronal signaling and plasticity in various animal models.

  13. Thermochemical cycles

    NASA Technical Reports Server (NTRS)

    Funk, J. E.; Soliman, M. A.; Carty, R. H.; Conger, W. L.; Cox, K. E.; Lawson, D.

    1975-01-01

    The thermochemical production of hydrogen is described along with the HYDRGN computer program which attempts to rate the various thermochemical cycles. Specific thermochemical cycles discussed include: iron sulfur cycle; iron chloride cycle; and hybrid sulfuric acid cycle.

  14. Spatiotemporal intracellular calcium dynamics during cardiac alternans

    PubMed Central

    Restrepo, Juan G.; Karma, Alain

    2009-01-01

    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. PMID:19792040

  15. Carotid Vascular Abnormalities in Primary Hyperparathyroidism

    PubMed Central

    Walker, M. D.; Fleischer, J.; Rundek, T.; McMahon, D. J.; Homma, S.; Sacco, R.; Silverberg, S. J.

    2009-01-01

    Context: Data on the presence, extent, and reversibility of cardiovascular disease in primary hyperparathyroidism (PHPT) are conflicting. Objective: This study evaluated carotid structure and function in PHPT patients compared with population-based controls. Design: This is a case-control study. Setting: The study was conducted in a university hospital metabolic bone disease unit. Participants: Forty-nine men and women with PHPT and 991 controls without PHPT were studied. Outcome Measures: We measured carotid intima-media thickness (IMT), carotid plaque presence and thickness, and carotid stiffness, strain, and distensibility. Results: IMT, carotid plaque thickness, carotid stiffness, and distensibility were abnormal in PHPT patients, and IMT was higher in patients than controls (0.959 vs. 0.907 mm, P < 0.0001). In PHPT, PTH levels, but not calcium concentration, predicted carotid stiffness (P = 0.04), strain (P = 0.06), and distensibility (P = 0.07). Patients with increased carotid stiffness had significantly higher PTH levels than did those with normal stiffness (141 ± 48 vs. 94.9 ± 44 pg/ml, P = 0.002), and odds of abnormal stiffness increased 1.91 (confidence interval = 1.09–3.35; P = 0.024) for every 10 pg/ml increase in PTH, adjusted for age, creatinine, and albumin-corrected calcium. Conclusions: Mild PHPT is associated with subclinical carotid vascular manifestations. IMT, a predictor of cardiovascular outcomes, is increased. Measures of carotid stiffness are associated with extent of PTH elevation, suggesting that those with more severe PHPT may have impaired vascular compliance and that PTH, rather than calcium, is the mediator. PMID:19755478

  16. Liver abnormalities in pregnancy.

    PubMed

    Than, Nwe Ni; Neuberger, James

    2013-08-01

    Abnormalities of liver function (notably rise in alkaline phosphatase and fall in serum albumin) are common in normal pregnancy, whereas rise in serum bilirubin and aminotransferase suggest either exacerbation of underlying pre-existing liver disease, liver disease related to pregnancy or liver disease unrelated to pregnancy. Pregnant women appear to have a worse outcome when infected with Hepatitis E virus. Liver diseases associated with pregnancy include abnormalities associated hyperemesis gravidarum, acute fatty liver disease, pre-eclampsia, cholestasis of pregnancy and HELLP syndrome. Prompt investigation and diagnosis is important in ensuring a successful maternal and foetal outcome. In general, prompt delivery is the treatment of choice for acute fatty liver, pre-eclampsia and HELLP syndrome and ursodeoxycholic acid is used for cholestasis of pregnancy although it is not licenced for this indication.

  17. Heritable bovine fetal abnormalities.

    PubMed

    Whitlock, B K; Kaiser, L; Maxwell, H S

    2008-08-01

    The etiologies for congenital bovine fetal anomalies can be divided into heritable, toxic, nutritional, and infectious categories. Although uncommon in most herds, inherited congenital anomalies are probably present in all breeds of cattle and propagated as a result of specific trait selection that inadvertently results in propagation of the defect. In some herds, the occurrence of inherited anomalies has become frequent, and economically important. Anomalous traits can affect animals in a range of ways, some being lethal or requiring euthanasia on humane grounds, others altering structure, function, or performance of affected animals. Veterinary practitioners should be aware of the potential for inherited defects, and be prepared to investigate and report animals exhibiting abnormal characteristics. This review will discuss the morphologic characteristics, mode of inheritance, breeding lines affected, and the availability of genetic testing for selected heritable bovine fetal abnormalities.

  18. Morphological abnormalities in elasmobranchs.

    PubMed

    Moore, A B M

    2015-08-01

    A total of 10 abnormal free-swimming (i.e., post-birth) elasmobranchs are reported from The (Persian-Arabian) Gulf, encompassing five species and including deformed heads, snouts, caudal fins and claspers. The complete absence of pelvic fins in a milk shark Rhizoprionodon acutus may be the first record in any elasmobranch. Possible causes, including the extreme environmental conditions and the high level of anthropogenic pollution particular to The Gulf, are briefly discussed.

  19. Abnormality, rationality, and sanity.

    PubMed

    Hertwig, Ralph; Volz, Kirsten G

    2013-11-01

    A growing body of studies suggests that neurological and mental abnormalities foster conformity to norms of rationality that are widely endorsed in economics and psychology, whereas normality stands in the way of rationality thus defined. Here, we outline the main findings of these studies, discuss their implications for experimental design, and consider how 'sane' some benchmarks of rationality really are. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Anatomical Abnormalities in Autism?

    PubMed

    Haar, Shlomi; Berman, Sigal; Behrmann, Marlene; Dinstein, Ilan

    2016-04-01

    Substantial controversy exists regarding the presence and significance of anatomical abnormalities in autism spectrum disorders (ASD). The release of the Autism Brain Imaging Data Exchange (∼1000 participants, age 6-65 years) offers an unprecedented opportunity to conduct large-scale comparisons of anatomical MRI scans across groups and to resolve many of the outstanding questions. Comprehensive univariate analyses using volumetric, thickness, and surface area measures of over 180 anatomically defined brain areas, revealed significantly larger ventricular volumes, smaller corpus callosum volume (central segment only), and several cortical areas with increased thickness in the ASD group. Previously reported anatomical abnormalities in ASD including larger intracranial volumes, smaller cerebellar volumes, and larger amygdala volumes were not substantiated by the current study. In addition, multivariate classification analyses yielded modest decoding accuracies of individuals' group identity (<60%), suggesting that the examined anatomical measures are of limited diagnostic utility for ASD. While anatomical abnormalities may be present in distinct subgroups of ASD individuals, the current findings show that many previously reported anatomical measures are likely to be of low clinical and scientific significance for understanding ASD neuropathology as a whole in individuals 6-35 years old.

  1. Chemical induction of sperm abnormalities in mice.

    PubMed Central

    Wyrobek, A J; Bruce, W R

    1975-01-01

    The sperm of (C57BL X C3H)F1 mice were examined 1, 4, and 10 weeks after a subacute treatment with one of 25 chemicals at two or more dose levels. The fraction of sperm that were abnormal in shape was elevated above control values of 1.2-3.4% for methyl methanesulfonate, ethyl methanesulfonate, griseofulvin, benzo[a]pyrene, METEPA [tris(2-methyl-l-aziridinyl)phosphine oxide], THIO-TEPA [tris(l-aziridinyl)phosphine sulfide], mitomycin C, myleran, vinblastine sulphate, hydroxyurea, 3-methylcholanthrene, colchicine, actinomycin D, imuran, cyclophosphamide, 5-iododeoxyuridine, dichlorvos, aminopterin, and trimethylphosphate. Dimethylnitrosamine, urethane, DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane], 1,1-dimethylhydrazine, caffeine, and calcium cyclamate did not induce elevated levels of sperm abnormalities. The results suggest that sperm abnormalities might provide a rapid inexpensive mammalian screen for agents that lead to errors in the differentiation of spermatogenic stem cells in vivo and thus indicate agents which might prove to be mutagenic, teratogenic, or carcinogenic. Images PMID:1060122

  2. Crystal structure of calcium dodecin (Rv0379), from Mycobacterium tuberculosis with a unique calcium-binding site

    SciTech Connect

    Arockiasamy, Arulandu; Aggarwal, Anup; Savva, Christos G.; Holzenburg, Andreas; Sacchettini, James C.

    2011-09-28

    In eukaryotes, calcium-binding proteins play a pivotal role in diverse cellular processes, and recent findings suggest similar roles for bacterial proteins at different stages in their life cycle. Here, we report the crystal structure of calcium dodecin, Rv0379, from Mycobacterium tuberculosis with a dodecameric oligomeric assembly and a unique calcium-binding motif. Structure and sequence analysis were used to identify orthologs of Rv0379 with different ligand-binding specificity

  3. Abnormal pressures as hydrodynamic phenomena

    USGS Publications Warehouse

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  4. [Molecular abnormalities in lymphomas].

    PubMed

    Delsol, G

    2010-11-01

    Numerous molecular abnormalities have been described in lymphomas. They are of diagnostic and prognostic value and are taken into account for the WHO classification of these tumors. They also shed some light on the underlying molecular mechanisms involved in lymphomas. Overall, four types of molecular abnormalities are involved: mutations, translocations, amplifications and deletions of tumor suppressor genes. Several techniques are available to detect these molecular anomalies: conventional cytogenetic analysis, multicolor FISH, CGH array or gene expression profiling using DNA microarrays. In some lymphomas, genetic abnormalities are responsible for the expression of an abnormal protein (e.g. tyrosine-kinase, transcription factor) detectable by immunohistochemistry. In the present review, molecular abnormalities observed in the most frequent B, T or NK cell lymphomas are discussed. In the broad spectrum of diffuse large B-cell lymphomas microarray analysis shows mostly two subgroups of tumors, one with gene expression signature corresponding to germinal center B-cell-like (GCB: CD10+, BCL6 [B-Cell Lymphoma 6]+, centerine+, MUM1-) and a subgroup expressing an activated B-cell-like signature (ABC: CD10-, BCL6-, centerine-, MUM1+). Among other B-cell lymphomas with well characterized molecular abnormalies are follicular lymphoma (BCL2 deregulation), MALT lymphoma (Mucosa Associated Lymphoid Tissue) [API2-MALT1 (mucosa-associated-lymphoid-tissue-lymphoma-translocation-gene1) fusion protein or deregulation BCL10, MALT1, FOXP1. MALT1 transcription factors], mantle cell lymphoma (cycline D1 [CCND1] overexpression) and Burkitt lymphoma (c-Myc expression). Except for ALK (anaplastic lymphoma kinase)-positive anaplastic large cell lymphoma, well characterized molecular anomalies are rare in lymphomas developed from T or NK cells. Peripheral T cell lymphomas not otherwise specified are a heterogeneous group of tumors with frequent but not recurrent molecular abnormalities

  5. CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT WITH SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  6. Alendronate affects calcium dynamics in cardiomyocytes in vitro.

    PubMed

    Kemeny-Suss, Naomi; Kasneci, Amanda; Rivas, Daniel; Afilalo, Jonathan; Komarova, Svetlana V; Chalifour, Lorraine E; Duque, Gustavo

    2009-01-01

    Therapy with bisphosphonates, including alendronate (ALN), is considered a safe and effective treatment for osteoporosis. However, recent studies have reported an unexpected increase in serious atrial fibrillation (AF) in patients treated with bisphosphonates. The mechanism that explains this side effect remains unknown. Since AF is associated with an altered sarcoendoplasmic reticulum calcium load, we studied how ALN affects cardiomyocyte calcium homeostasis and protein isoprenylation in vitro. Acute and long-term (48h) treatment of atrial and ventricular cardiomyocytes with ALN (10(-8)-10(-6)M) was performed. Changes in calcium dynamics were determined by both fluorescence measurement of cytosolic free Ca(2+) concentration and western blot analysis of calcium-regulating proteins. Finally, effect of ALN on protein farnesylation was also identified. In both atrial and ventricular cardiomyocytes, ALN treatment delayed and diminished calcium responses to caffeine. Only in atrial cells, long-term exposure to ALN-induced transitory calcium oscillations and led to the development of oscillatory component in calcium responses to caffeine. Changes in calcium dynamics were accompanied by changes in expression of proteins controlling sarcoendoplasmic reticulum calcium. In contrast, ALN minimally affected protein isoprenylation in these cells. In summary, treatment of atrial cardiomyocytes with ALN-induced abnormalities in calcium dynamics consistent with induction of a self-stimulatory, pacemaker-like behavior, which may contribute to the development of cardiac side effects associated with these drugs.

  7. Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

    ERIC Educational Resources Information Center

    Fernald, Charles D.

    1980-01-01

    Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

  8. Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

    ERIC Educational Resources Information Center

    Fernald, Charles D.

    1980-01-01

    Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

  9. [Do cows drink calcium?].

    PubMed

    Geishauser, T; Lechner, S; Plate, I; Heidemann, B

    2008-03-01

    The objective of this study was to investigate how well cows drink the Propeller calcium drink, and it's effect on blood calcium concentration. Drinking was tested in 120 cows right after calving, before cows drank anything else. 60 cows each were offered 20 liters of Propeller calcium drink or 20 liters of water. Cows drank the Propeller as good as water. 72% of all cows drank all 20 liters, 18% drank on average 8.2 liters and 10% drank less than 1 liter. Blood calcium concentration was studied in 16 cows right after calving. Eight cows each were offered 20 liters of Propeller calcium drink or no calcium drink. Blood calcium significantly increased ten minutes after Propeller intake and stayed significantly elevated for 24 hours. Without calcium drink blood calcium levels decreased significantly. Advantages of the new Propeller calcium drink over calcium gels or boli could be that cows now drink calcium themselves and that the Propeller increases blood calcium concentration rapidly and long lasting.

  10. A calcium oxygen secondary battery

    NASA Astrophysics Data System (ADS)

    Pujare, Nirupama U.; Semkow, Krystyna W.; Sammells, Anthony F.

    1988-01-01

    This paper describes a high-temperature electrochemically-reversible calcium-oxygen cell in which the negative electroactive material consists of a calcium-silicon alloy contained within an expanded stainless steel electrode assembly immersed into a binary molten salt CaO-CaCl2 (mp 593 C). The empirical electrochemistry occurring upon electrochemical cycling is: 2CaSi + 1/2 O2(air) going to CaO + CaSi2, with oxygen being reversibly mediated to the binary molten salt via the oxygen vacancy conducting solid electrolyte; charge-discharge curves at 850 C clearly demonstrated voltage plateaus associated with the reversible formation of CaSi and CaSi2. If unit activity Ca were used as the negative electroactive material, the cell thermodynamic open-circuit voltage at 850 C is expected to be about 2.28 V. The theoretical energy density for this system calculates to 985 W h/lb.

  11. Abnormal human sex chromosome constitutions

    SciTech Connect

    1993-12-31

    Chapter 22, discusses abnormal human sex chromosome constitution. Aneuploidy of X chromosomes with a female phenotype, sex chromosome aneuploidy with a male phenotype, and various abnormalities in X chromosome behavior are described. 31 refs., 2 figs.

  12. Exercises to Improve Gait Abnormalities

    MedlinePlus

    ... Home About iChip Articles Directories Videos Resources Contact Exercises to Improve Gait Abnormalities Home » Article Categories » Exercise and Fitness Font Size: A A A A Exercises to Improve Gait Abnormalities Next Page The manner ...

  13. Abnormal Uterine Bleeding.

    PubMed

    Benetti-Pinto, Cristina Laguna; Rosa-E-Silva, Ana Carolina Japur de Sá; Yela, Daniela Angerame; Soares Júnior, José Maria

    2017-07-01

    Abnormal uterine bleeding is a frequent condition in Gynecology. It may impact physical, emotional sexual and professional aspects of the lives of women, impairing their quality of life. In cases of acute and severe bleeding, women may need urgent treatment with volumetric replacement and prescription of hemostatic substances. In some specific cases with more intense and prolonged bleeding, surgical treatment may be necessary. The objective of this chapter is to describe the main evidence on the treatment of women with abnormal uterine bleeding, both acute and chronic. Didactically, the treatment options were based on the current International Federation of Gynecology and Obstetrics (FIGO) classification system (PALM-COEIN). The etiologies of PALM-COEIN are: uterine Polyp (P), Adenomyosis (A), Leiomyoma (L), precursor and Malignant lesions of the uterine body (M), Coagulopathies (C), Ovulatory dysfunction (O), Endometrial dysfunction (E), Iatrogenic (I), and Not yet classified (N). The articles were selected according to the recommendation grades of the PubMed, Cochrane and Embase databases, and those in which the main objective was the reduction of uterine menstrual bleeding were included. Only studies written in English were included. All editorial or complete papers that were not consistent with abnormal uterine bleeding, or studies in animal models, were excluded. The main objective of the treatment is the reduction of menstrual flow and morbidity and the improvement of quality of life. It is important to emphasize that the treatment in the acute phase aims to hemodynamically stabilize the patient and stop excessive bleeding, while the treatment in the chronic phase is based on correcting menstrual dysfunction according to its etiology and clinical manifestations. The treatment may be surgical or pharmacological, and the latter is based mainly on hormonal therapy, anti-inflammatory drugs and antifibrinolytics. Thieme Revinter Publicações Ltda Rio de Janeiro

  14. Placental calcium pump: clinical-based evidence.

    PubMed

    Kasznica, John M; Petcu, Eugen B

    2003-01-01

    Placenta can be considered as a pump of calcium necessary for the normal development of the fetus. We believe that the location of this pump is in the placental basement membrane. The calcification of this membrane has been described only in cases of in utero fetal death. In this study we describe for the first time a case of placental calcification in a living fetus. The fetus of a normal 21-year-old pregnant woman showed heart abnormalities but the genetic analysis showed a normal male karyotype. The histology of the placenta demonstrated multiple intravillous linear and granular calcific incrustations The hemtoxylin/eosin stain of the sections revealed basement membrane calcific incrustations and intravillous calcium deposits. We postulate that the fetal circulation in the villi was impaired and the calcium that reached the villi from the mother was deposited at this level.

  15. Calcium in diet

    MedlinePlus

    ... Salmon and sardines canned with their soft bones Almonds, Brazil nuts, sunflower seeds, tahini, and dried beans ... greens = 100 mg of calcium ¼ cup of almonds = 100 mg of calcium 1 medium orange = 50 ...

  16. Integumentary loss of calcium.

    PubMed

    Chu, J Y; Margen, S; Calloway, D H; Costa, F M

    1979-08-01

    Integumentary calcium loss was studied in 16 healthy young men. The daily loss by the 16 ambulatory but relatively sedentary young men in 52 determinations of 6-day periods each was 8.7 +/- 1.9 mg/m2 per day (average 15.8 mg/man per day). The amount lost was not influenced by calcium intake (0.1 to 2.3 g/day). In contrast to urinary calcium excretion, which is directly related to protein intake, there was no significant change in integumentary calcium loss with varying protein intakes (1 to 96 g nitrogen per day). No compensatory relationship between urinary and integumentary calcium excretion was noted. During strenuous exercise calcium loss increased to an average of 25 mg in 40 min. There was no compensatory decrease in urinary excretion on the day of strenuous exercise. It was also noted that integumentary calcium loss was not affected by general calcium balance.

  17. Calcium Pyrophosphate Deposition (CPPD)

    MedlinePlus

    ... too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected joint. CPPD ... using a microscope to see small calcium pyrophosphate crystals in joint fluid. Anti-inflammatory medications reduce pain ...

  18. Calcium and Mitosis

    NASA Technical Reports Server (NTRS)

    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.

  19. Calcium and Mitosis

    NASA Technical Reports Server (NTRS)

    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.

  20. Direct Imaging of Hippocampal Epileptiform Calcium Motifs Following Kainic Acid Administration in Freely Behaving Mice

    PubMed Central

    Berdyyeva, Tamara K.; Frady, E. Paxon; Nassi, Jonathan J.; Aluisio, Leah; Cherkas, Yauheniya; Otte, Stephani; Wyatt, Ryan M.; Dugovic, Christine; Ghosh, Kunal K.; Schnitzer, Mark J.; Lovenberg, Timothy; Bonaventure, Pascal

    2016-01-01

    Prolonged exposure to abnormally high calcium concentrations is thought to be a core mechanism underlying hippocampal damage in epileptic patients; however, no prior study has characterized calcium activity during seizures in the live, intact hippocampus. We have directly investigated this possibility by combining whole-brain electroencephalographic (EEG) measurements with microendoscopic calcium imaging of pyramidal cells in the CA1 hippocampal region of freely behaving mice treated with the pro-convulsant kainic acid (KA). We observed that KA administration led to systematic patterns of epileptiform calcium activity: a series of large-scale, intensifying flashes of increased calcium fluorescence concurrent with a cluster of low-amplitude EEG waveforms. This was accompanied by a steady increase in cellular calcium levels (>5 fold increase relative to the baseline), followed by an intense spreading calcium wave characterized by a 218% increase in global mean intensity of calcium fluorescence (n = 8, range [114–349%], p < 10−4; t-test). The wave had no consistent EEG phenotype and occurred before the onset of motor convulsions. Similar changes in calcium activity were also observed in animals treated with 2 different proconvulsant agents, N-methyl-D-aspartate (NMDA) and pentylenetetrazol (PTZ), suggesting the measured changes in calcium dynamics are a signature of seizure activity rather than a KA-specific pathology. Additionally, despite reducing the behavioral severity of KA-induced seizures, the anticonvulsant drug valproate (VA, 300 mg/kg) did not modify the observed abnormalities in calcium dynamics. These results confirm the presence of pathological calcium activity preceding convulsive motor seizures and support calcium as a candidate signaling molecule in a pathway connecting seizures to subsequent cellular damage. Integrating in vivo calcium imaging with traditional assessment of seizures could potentially increase translatability of pharmacological

  1. [Penile congenital abnormalities].

    PubMed

    Boillot, B; Teklali, Y; Moog, R; Droupy, S

    2013-07-01

    Congenital abnormalities of the penis are usually diagnosed at birth and pose aesthetic and functional problems sometimes requiring surgical management. A literature review was conducted on Medline considering the articles listed until January 2012. Hypospadias is the most common malformation (1 in 250 boys. Familial forms: 7%). The causes remain hypothetical but the doubling of the incidence in 30 years could be linked to fetal exposure to endocrine disruptors "estrogen-like" used in the food industry in particular. Surgical treatment is usually intended to improve the aesthetic appearance but sometimes, in case of significant curvature or posterior meatus, necessary for normal sexual life and fertility. Other malformations (epispades, buried penis, transpositions, twists and preputial abnormalities) as well as management for functional or aesthetic consequences of these malformations in adulthood require complex surgical care in a specialized environment. The improvement of surgical techniques and pediatric anesthesia allows an early and effective specialized surgical approach of penile malformations. Management of sequelae in adulthood must be discussed and requires experience of surgical techniques on pediatric and adult penis. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  2. Epilepsy and chromosomal abnormalities

    PubMed Central

    2010-01-01

    Background Many chromosomal abnormalities are associated with Central Nervous System (CNS) malformations and other neurological alterations, among which seizures and epilepsy. Some of these show a peculiar epileptic and EEG pattern. We describe some epileptic syndromes frequently reported in chromosomal disorders. Methods Detailed clinical assessment, electrophysiological studies, survey of the literature. Results In some of these congenital syndromes the clinical presentation and EEG anomalies seems to be quite typical, in others the manifestations appear aspecific and no strictly linked with the chromosomal imbalance. The onset of seizures is often during the neonatal period of the infancy. Conclusions A better characterization of the electro clinical patterns associated with specific chromosomal aberrations could give us a valuable key in the identification of epilepsy susceptibility of some chromosomal loci, using the new advances in molecular cytogenetics techniques - such as fluorescent in situ hybridization (FISH), subtelomeric analysis and CGH (comparative genomic hybridization) microarray. However further studies are needed to understand the mechanism of epilepsy associated with chromosomal abnormalities. PMID:20438626

  3. [Bone and calcium metabolism in life-style related diseases].

    PubMed

    Kanazawa, Ippei; Sugimoto, Toshitsugu

    2016-03-01

    Accumulating evidence shows that life-style related diseases such as diabetes mellitus, hypertension, dyslipidemia are associated with bone and calcium metabolism. Patients with diabetes mellitus have increased fracture risks, independently of bone mineral density, with abnormality of parathyroid hormone secretion and impaired osteoblastic function. On the other hand, osteocalcin secreted from bone is reported to regulate glucose metabolism. Thus, bone, calcium and glucose metabolism may be deeply associated with each other. In this review, we describe the association between life-style related diseases, especially diabetes mellitus, and metabolism of bone and calcium.

  4. Calcium bioavailability from calcium fortified food products.

    PubMed

    Kohls, K

    1991-08-01

    The calcium balance of 12 presumed healthy human young adult subjects was assessed. Subjects consumed a constant laboratory-controlled diet supplemented with one of four calcium-fortified food products: orange juice (OJ), milk (M), experimental pasteurized processed cheese (T), soda (S), or a calcium carbonate plus vitamin D tablet (CC). Study length was 6 weeks with seven-day experimental periods (2-days allowed for adjustment with 5-days combined for purposes of analysis). All urine and fecal samples were collected by the subjects for the duration of the study. Blood samples were drawn at the end of each experimental period. Urine and fecal calcium contents were determined. Blood samples were analyzed for alkaline phosphatase. Results of this study indicate a higher fecal calcium content (mg/day) when subjects consumed CC and T, and when subjects consumed self-selected diets, than when given S, M, or OJ. Urinary calcium excretion was significantly lower when subjects consumed OJ than when they consumed M, T, or their self-selected diets. A significantly larger positive calcium balance was demonstrated when subjects consumed OJ as compared to T. Fecal transmit time did not vary significantly. Serum alkaline phosphatase was significantly lower when subjects consumed T than when they consumed self-selected diets.

  5. Skeleton-Based Abnormal Gait Detection.

    PubMed

    Nguyen, Trong-Nguyen; Huynh, Huu-Hung; Meunier, Jean

    2016-10-26

    Human gait analysis plays an important role in musculoskeletal disorder diagnosis. Detecting anomalies in human walking, such as shuffling gait, stiff leg or unsteady gait, can be difficult if the prior knowledge of such a gait pattern is not available. We propose an approach for detecting abnormal human gait based on a normal gait model. Instead of employing the color image, silhouette, or spatio-temporal volume, our model is created based on human joint positions (skeleton) in time series. We decompose each sequence of normal gait images into gait cycles. Each human instant posture is represented by a feature vector which describes relationships between pairs of bone joints located in the lower body. Such vectors are then converted into codewords using a clustering technique. The normal human gait model is created based on multiple sequences of codewords corresponding to different gait cycles. In the detection stage, a gait cycle with normality likelihood below a threshold, which is determined automatically in the training step, is assumed as an anomaly. The experimental results on both marker-based mocap data and Kinect skeleton show that our method is very promising in distinguishing normal and abnormal gaits with an overall accuracy of 90.12%.

  6. Skeleton-Based Abnormal Gait Detection

    PubMed Central

    Nguyen, Trong-Nguyen; Huynh, Huu-Hung; Meunier, Jean

    2016-01-01

    Human gait analysis plays an important role in musculoskeletal disorder diagnosis. Detecting anomalies in human walking, such as shuffling gait, stiff leg or unsteady gait, can be difficult if the prior knowledge of such a gait pattern is not available. We propose an approach for detecting abnormal human gait based on a normal gait model. Instead of employing the color image, silhouette, or spatio-temporal volume, our model is created based on human joint positions (skeleton) in time series. We decompose each sequence of normal gait images into gait cycles. Each human instant posture is represented by a feature vector which describes relationships between pairs of bone joints located in the lower body. Such vectors are then converted into codewords using a clustering technique. The normal human gait model is created based on multiple sequences of codewords corresponding to different gait cycles. In the detection stage, a gait cycle with normality likelihood below a threshold, which is determined automatically in the training step, is assumed as an anomaly. The experimental results on both marker-based mocap data and Kinect skeleton show that our method is very promising in distinguishing normal and abnormal gaits with an overall accuracy of 90.12%. PMID:27792181

  7. Eye movement abnormalities.

    PubMed

    Moncayo, Jorge; Bogousslavsky, Julien

    2012-01-01

    Generation and control of eye movements requires the participation of the cortex, basal ganglia, cerebellum and brainstem. The signals of this complex neural network finally converge on the ocular motoneurons of the brainstem. Infarct or hemorrhage at any level of the oculomotor system (though more frequent in the brain-stem) may give rise to a broad spectrum of eye movement abnormalities (EMAs). Consequently, neurologists and particularly stroke neurologists are routinely confronted with EMAs, some of which may be overlooked in the acute stroke setting and others that, when recognized, may have a high localizing value. The most complex EMAs are due to midbrain stroke. Horizontal gaze disorders, some of them manifesting unusual patterns, may occur in pontine stroke. Distinct varieties of nystagmus occur in cerebellar and medullary stroke. This review summarizes the most representative EMAs from the supratentorial level to the brainstem.

  8. Skeletal abnormalities in homocystinuria.

    PubMed Central

    Brenton, D. P.

    1977-01-01

    The skeletal changes of thirty-four patients with the biochemical and clinical features of cystathionine synthase deficiency are described. It is emphasized that there is clinical evidence of excessive bone growth and the formation for bone which is structurally weaker than normal. The similarities and differences between this condition and Marfan's syndrome are stressed and the possible nature of the connective tissue defect leading to the skeletal changes discussed. The most characteristic skeletal changes in homocystinuria are the skeletal disproportion (pubis-heel length greater than crown-pubis length), the abnormal vertebrae, sternal deformities, genu valgum and large metaphyses and epiphyses. Images Fig. 2 Fig. 3 Fig. 4 Fig. 8 Fig. 9 Fig. 10 PMID:917963

  9. The regulation of neuronal mitochondrial metabolism by calcium

    PubMed Central

    Llorente-Folch, I; Rueda, C B; Pardo, B; Szabadkai, G; Duchen, M R; Satrustegui, J

    2015-01-01

    Calcium signalling is fundamental to the function of the nervous system, in association with changes in ionic gradients across the membrane. Although restoring ionic gradients is energetically costly, a rise in intracellular Ca2+ acts through multiple pathways to increase ATP synthesis, matching energy supply to demand. Increasing cytosolic Ca2+ stimulates metabolite transfer across the inner mitochondrial membrane through activation of Ca2+-regulated mitochondrial carriers, whereas an increase in matrix Ca2+ stimulates the citric acid cycle and ATP synthase. The aspartate–glutamate exchanger Aralar/AGC1 (Slc25a12), a component of the malate–aspartate shuttle (MAS), is stimulated by modest increases in cytosolic Ca2+ and upregulates respiration in cortical neurons by enhancing pyruvate supply into mitochondria. Failure to increase respiration in response to small (carbachol) and moderate (K+-depolarization) workloads and blunted stimulation of respiration in response to high workloads (veratridine) in Aralar/AGC1 knockout neurons reflect impaired MAS activity and limited mitochondrial pyruvate supply. In response to large workloads (veratridine), acute stimulation of respiration occurs in the absence of MAS through Ca2+ influx through the mitochondrial calcium uniporter (MCU) and a rise in matrix [Ca2+]. Although the physiological importance of the MCU complex in work-induced stimulation of respiration of CNS neurons is not yet clarified, abnormal mitochondrial Ca2+ signalling causes pathology. Indeed, loss of function mutations in MICU1, a regulator of MCU complex, are associated with neuromuscular disease. In patient-derived MICU1 deficient fibroblasts, resting matrix Ca2+ is increased and mitochondria fragmented. Thus, the fine tuning of Ca2+ signals plays a key role in shaping mitochondrial bioenergetics. PMID:25809592

  10. Stretch-activated calcium channels relay fast calcium waves propagated by calcium-induced calcium influx.

    PubMed

    Jaffe, Lionel F

    2007-03-01

    For nearly 30 years, fast calcium waves have been attributed to a regenerative process propagated by CICR (calcium-induced calcium release) from the endoplasmic reticulum. Here, I propose a model containing a new subclass of fast calcium waves which is propagated by CICI (calcium-induced calcium influx) through the plasma membrane. They are called fast CICI waves. These move at the order of 100 to 1000 microm/s (at 20 degrees C), rather than the order of 3 to 30 microm/s found for CICR. Moreover, in this proposed subclass, the calcium influx which drives calcium waves is relayed by stretch-activated calcium channels. This model is based upon reports from approx. 60 various systems. In seven of these reports, calcium waves were imaged, and, in five of these, evidence was presented that these waves were regenerated by CICI. Much of this model involves waves that move along functioning flagella and cilia. In these systems, waves of local calcium influx are thought to cause waves of local contraction by inducing the sliding of dynein or of kinesin past tubulin microtubules. Other cells which are reported to exhibit waves, which move at speeds in the fast CICI range, include ones from a dozen protozoa, three polychaete worms, three molluscs, a bryozoan, two sea urchins, one arthropod, four insects, Amphioxus, frogs, two fish and a vascular plant (Equisetum), together with numerous healthy, as well as cancerous, mammalian cells, including ones from human. In two of these systems, very gentle local mechanical stimulation is reported to initiate waves. In these non-flagellar systems, the calcium influxes are thought to speed the sliding of actinomyosin filaments past each other. Finally, I propose that this mechanochemical model could be tested by seeing if gentle mechanical stimulation induces waves in more of these systems and, more importantly, by imaging the predicted calcium waves in more of them.

  11. Autoshaping of abnormal children.

    PubMed

    Deckner, C W; Wilcox, L M; Maisto, S A; Blanton, R L

    1980-09-01

    Three experimentally naive abnormal children were exposed to a terminal operant contingency, i.e., reinforcement was delivered only if the children pressed a panel during intervals when it was lighted. Despite the absence of both successive approximation and manual shaping, it was found that each child began to respond discriminatively within a small number of trials. These data replicated previous animal studies concerned with the phenomena of autoshaping and signal-controlled responding. It was also found, however, that one type of autoshaping, the classical conditioning procedure, had a powerful suppressive effect on the discriminative responding. An experimental analysis that consisted procedure, had a powerful suppressive effect on discriminative responding. An experimental analysis that consisted of intrasubject reversal an multiple baseline designs established the internal validity of the findings. The finding of rapid acquisition of signal-controlled responding obtained with the initial procedure is suggessted to have practical significance. The disruptive effects of the classical form of autoshaping are discussed in terms of negative behavioral contrast.

  12. Communication and abnormal behaviour.

    PubMed

    Crown, S

    1979-01-01

    In this paper the similarities between normal and abnormal behaviour are emphasized and selected aspects of communication, normal and aberrant, between persons are explored. Communication in a social system may be verbal or non-verbal: one person's actions cause a response in another person. This response may be cognitive, behavioural or physiological. Communication may be approached through the individual, the social situation or social interaction. Psychoanalysis approaches the individual in terms of the coded communications of psychoneurotic symptoms or psychotic behaviour; the humanist-existential approach is concerned more with emotional expression. Both approaches emphasize the development of individual identity. The interaction between persons and their social background is stressed. Relevant are sociological concepts such as illness behaviour, stigma, labelling, institutionalization and compliance. Two approaches to social interactions are considered: the gamesplaying metaphor, e.g. back pain as a psychosocial manipulation--the 'pain game'; and the 'spiral of reciprocal perspectives' which emphasizes the interactional complexities of social perceptions. Communicatory aspects of psychological treatments are noted: learning a particular metaphor such as 'resolution' of the problem (psychotherapy), learning more 'rewarding' behaviour (learning theory) or learning authenticity or self-actualization (humanist-existential).

  13. [Abnormality of thyroid function].

    PubMed

    Masamune, Taishi; Matsukawa, Takashi

    2010-07-01

    The thyroid hormones are synthesized by iodine. Thyroid dysfunction can develop in patients who have received treatment with iodine-containing contrast media or treatment with amiodarone. Thyrotoxicosis is a symptom due to high levels of thyroid hormone. The entity most threatened is the cardiovascular system. beta-adrenergic receptor blockade can control the heart rate. And a decreasing heart rate may improve heart-pumping function. We should aim to avoid surgery on any patients whose thyroid function is abnormal. The avoidance of a thyroid storm is the goal in managing hyperthyroid patients. Suppression of the sympathetic tone and maintenance of a deep level of surgical anesthesia are prudent. Thyroid storm is rare nowadays but still carries a high mortality. Precipitating factors include infection, surgery, childbirth or trauma, et al. Hypothyroid patients are sensitive to the effects of anesthetic agents and many drugs, including opioids. Mild hypothyroidism may have little perioperative significance. However, overt hypothyroidism can develop in a high percentage of patients with history of subclinical hypothyroidism. An untreated patient with hypothyroidism may present as an emergency with myxedema coma. Myxedema coma is rare but carries a high mortality. Precipitating factors include hypothermia, surgery, trauma, sedative drugs, et al.

  14. Novel brain MRI abnormalities in Gitelman syndrome

    PubMed Central

    Norbash, Alexander; Vattoth, Surjith

    2015-01-01

    Gitelman syndrome is an autosomal recessive renal tubular disorder characterized by hypokalemic metabolic alkalosis, hypomagnesemia and hypocalciuria. The syndrome is caused by a defective thiazide-sensitive sodium chloride co-transporter in the distal convoluted tubules of the kidneys. Gitelman syndrome could be confused with Bartter syndrome; the main differentiating feature is the presence of low urinary calcium excretion in the former. Descriptions of neuroradiological imaging findings associated with Gitelman syndrome are very scarce in the literature and include basal ganglia calcification, idiopathic intracranial hypertension and sclerochoroidal calcification. Cauda equina syndrome-like presentation has been reported, but without any corresponding imaging findings on lumbar spine MRI. We report a 13-year-old male with Gitelman syndrome who presented with altered mental status following a fall and scalp laceration and unremarkable brain CT, followed during hospitalization by somnolence and seizures. Metabolically the patient demonstrated hypokalemia and hypomagnesemia. MRI demonstrated features of encephalopathy including predominantly right-sided cerebral hemispheric signal abnormality and cytotoxic edema, with bilateral symmetric involvement of the thalami, midbrain tegmentum and tectum and cerebellar dentate nuclei. MRI after five months obtained during a later episode of encephalopathy showed resolution of the signal abnormalities with setting in of brain atrophy and also areas of newly developed cytotoxic edema in the left thalamus, bilateral dorsal midbrain and right greater than left dentate nuclei. The described abnormalities, either recurrent or in isolation, have not previously been published in patients with Gitelman syndrome. We believe that the findings are due to alteration of respiratory chain function secondary to the metabolic derangement and hence have a similar imaging appearance as encephalopathy related to mitochondrial cytopathy or

  15. [Walking abnormalities in children].

    PubMed

    Segawa, Masaya

    2010-11-01

    Walking is a spontaneous movement termed locomotion that is promoted by activation of antigravity muscles by serotonergic (5HT) neurons. Development of antigravity activity follows 3 developmental epochs of the sleep-wake (S-W) cycle and is modulated by particular 5HT neurons in each epoch. Activation of antigravity activities occurs in the first epoch (around the age of 3 to 4 months) as restriction of atonia in rapid eye movement (REM) stage and development of circadian S-W cycle. These activities strengthen in the second epoch, with modulation of day-time sleep and induction of crawling around the age of 8 months and induction of walking by 1 year. Around the age of 1 year 6 months, absence of guarded walking and interlimb cordination is observed along with modulation of day-time sleep to once in the afternoon. Bipedal walking in upright position occurs in the third epoch, with development of a biphasic S-W cycle by the age of 4-5 years. Patients with infantile autism (IA), Rett syndrome (RTT), or Tourette syndrome (TS) show failure in the development of the first, second, or third epoch, respectively. Patients with IA fail to develop interlimb coordination; those with RTT, crawling and walking; and those with TS, walking in upright posture. Basic pathophysiology underlying these condition is failure in restricting atonia in REM stage; this induces dysfunction of the pedunculopontine nucleus and consequently dys- or hypofunction of the dopamine (DA) neurons. DA hypofunction in the developing brain, associated with compensatory upward regulation of the DA receptors causes psychobehavioral disorders in infancy (IA), failure in synaptogenesis in the frontal cortex and functional development of the motor and associate cortexes in late infancy through the basal ganglia (RTT), and failure in functional development of the prefrontal cortex through the basal ganglia (TS). Further, locomotion failure in early childhood causes failure in development of functional

  16. Calcium hydroxide poisoning

    MedlinePlus

    These products contain calcium hydroxide: Cement Limewater Many industrial solvents and cleaners (hundreds to thousands of construction products, flooring strippers, brick cleaners, cement thickening products, and many ...

  17. Calcium Channel Blockers

    MedlinePlus

    ... calcium channel blockers interact with grapefruit products. References Kaplan NM, et al. Treatment of hypertension: Drug therapy. In: Kaplan's Clinical Hypertension. 11th ed. Philadelphia, Pa.: Wolters Kluwer ...

  18. Calcium: total or ionized?

    PubMed

    Schenck, Patricia A; Chew, Dennis J

    2008-05-01

    Measurement of serum total calcium (tCa) has been relied on for assessment of calcium status, despite the fact that it is the ionized calcium (iCa) fraction that has biologic activity. Serum tCa does not accurately predict iCa status in many clinical conditions. For accurate assessment of iCa status, iCa should be directly measured. Anaerobic measurement of serum iCa under controlled conditions provides the most reliable assessment of calcium status; aerobic measurement of iCa with species-specific pH correction is highly correlated with anaerobic measurements.

  19. Calcium bodies of Titanethes albus (Crustacea: Isopoda): molt-related structural dynamics and calcified matrix-associated bacteria.

    PubMed

    Vittori, Miloš; Kostanjšek, Rok; Znidaršič, Nada; Zagar, Kristina; Ceh, Miran; Strus, Jasna

    2012-10-01

    Crustaceans form a variety of calcium deposits in which they store calcium necessary for the mineralization of their exoskeletons. Calcium bodies, organs containing large amounts of calcium, have been reported in some terrestrial isopod crustaceans, but have not yet been extensively studied. We analyzed the architecture of these organs during the molt cycle in the isopod Titanethes albus. Two pairs of calcium bodies are positioned ventrolaterally in posterior pereonites of T. albus. Individual organs are epithelial sacs that contain material arranged in concentric layers delimited by thin laminae. As demonstrated by electron microscopy and fluorescence in situ hybridization, abundant bacteria are present within the calcium bodies. Regardless of the molt cycle stage, crystalline concretions are present in the central areas of the calcium bodies. Energy dispersive X-ray spectrometry of the concretions demonstrated that they are composed predominantly of calcium and phosphorus and selected area electron diffraction indicated the presence of hydroxyapatite. In molting animals, a glassy layer of mineralized matrix is formed between the envelope and the outermost lamina of the calcium body. This layer consists of an amorphous calcium mineral which contains less phosphorus than the central concretions and is resorbed after molt. Since changes in the mineralized matrix are synchronized with the molt cycle, the calcium bodies likely function as a storage compartment that complements sternal deposits as a source of calcium for the mineralization of the exoskeleton. Bacteria associated with the mineralized matrix of calcium bodies are evidently involved in calcium dynamics.

  20. Do calcium-dependent ionic currents mediate ischemic ventricular fibrillation?

    PubMed

    Clusin, W T; Bristow, M R; Karagueuzian, H S; Katzung, B G; Schroeder, J S

    1982-02-18

    Calcium ions mediate the adverse effects of myocardial ischemia and have been implicated in the genesis of arrhythmias. Calcium influx blocking drugs protect against early ventricular arrhythmias during experimental coronary occlusion, and recent studies suggest that this effect is at least partly due to inhibition of myocardial cell calcium influx. Most of the pharmacologic maneuvers used to simulate acute ischemic arrhythmias in vivo also produce intracellular calcium overload. Production of calcium overload in small myocardial cell clusters causes fibrillatory electrical and mechanical activity similar to that recorded from fibrillating hearts. Fibrillation in these cell clusters is mediated not by reentrant conduction, but by the same subcellular processes that give rise to depolarizing afterpotentials and abnormal automaticity. Agents favoring calcium influx, such as beta adrenergic agonists, accentuate these processes, while agents that depress calcium influx inhibit them. Although the relation of these experimental models to clinical ischemic arrhythmias has not been fully delineated, calcium influx blocking drugs may prove useful in reducing the incidence of sudden cardiac death.

  1. Abnormal pressure in hydrocarbon environments

    USGS Publications Warehouse

    Law, B.E.; Spencer, C.W.

    1998-01-01

    Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

  2. Systemic abnormalities in liver disease

    PubMed Central

    Minemura, Masami; Tajiri, Kazuto; Shimizu, Yukihiro

    2009-01-01

    Systemic abnormalities often occur in patients with liver disease. In particular, cardiopulmonary or renal diseases accompanied by advanced liver disease can be serious and may determine the quality of life and prognosis of patients. Therefore, both hepatologists and non-hepatologists should pay attention to such abnormalities in the management of patients with liver diseases. PMID:19554648

  3. Calcium fluoride window mounting

    NASA Astrophysics Data System (ADS)

    Berger, D. Douglas

    1982-10-01

    A technique has been developed for joining a large calcium fluoride crystal to a stainless-steel flange by means of a silver transition ring. The process involves both vacuum brazing using a copper-silver alloy and air brazing using silver chloride. This paper describes the procedure used in fabricating a high-vacuum leak-tight calcium fluoride window assembly.

  4. Calcium and bones (image)

    MedlinePlus

    ... for the growth, maintenance, and reproduction of the human body. Bones, like other tissues in the body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the formation of and maintenance of healthy teeth.

  5. Role of calcium in growth inhibition induced by a novel cell surface sialoglycopeptide

    NASA Technical Reports Server (NTRS)

    Betz, N. A.; Westhoff, B. A.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    Our laboratory has purified an 18 kDa cell surface sialoglycopeptide growth inhibitor (CeReS-18) from intact bovine cerebral cortex cells. Evidence presented here demonstrates that sensitivity to CeReS-18-induced growth inhibition in BALB-c 3T3 cells is influenced by calcium, such that a decrease in the calcium concentration in the growth medium results in an increase in sensitivity to CeReS-18. Calcium did not alter CeReS-18 binding to its cell surface receptor and CeReS-18 does not bind calcium directly. Addition of calcium, but not magnesium, to CeReS-18-inhibited 3T3 cells results in reentry into the cell cycle. A greater than 3-hour exposure to increased calcium is required for escape from CeReS-18-induced growth inhibition. The calcium ionophore ionomycin could partially mimic the effect of increasing extracellular calcium, but thapsigargin was ineffective in inducing escape from growth inhibition. Increasing extracellular calcium 10-fold resulted in an approximately 7-fold increase in total cell-associated 45Ca+2, while free intracellular calcium only increased approximately 30%. However, addition of CeReS-18 did not affect total cell-associated calcium or the increase in total cell-associated calcium observed with an increase in extracellular calcium. Serum addition induced mobilization of intracellular calcium and influx across the plasma membrane in 3T3 cells, and pretreatment of 3T3 cells with CeReS-18 appeared to inhibit these calcium mobilization events. These results suggest that a calcium-sensitive step exists in the recovery from CeReS-18-induced growth inhibition. CeReS-18 may inhibit cell proliferation through a novel mechanism involving altering the intracellular calcium mobilization/regulation necessary for cell cycle progression.

  6. Cinacalcet, dialysate calcium concentration, and cardiovascular events in the EVOLVE trial.

    PubMed

    Pun, Patrick H; Abdalla, Safa; Block, Geoffrey A; Chertow, Glenn M; Correa-Rotter, Ricardo; Dehmel, Bastian; Drüeke, Tilman B; Floege, Jürgen; Goodman, William G; Herzog, Charles A; London, Gerard M; Mahaffey, Kenneth W; Moe, Sharon M; Parfrey, Patrick S; Wheeler, David C; Middleton, John P

    2016-07-01

    Among patients receiving hemodialysis, abnormalities in calcium regulation have been linked to an increased risk of cardiovascular events. Cinacalcet lowers serum calcium concentrations through its effect on parathyroid hormone secretion and has been hypothesized to reduce the risk of cardiovascular events. In observational cohort studies, prescriptions of low dialysate calcium concentration and larger observed serum-dialysate calcium gradients have been associated with higher risks of in-dialysis facility or peri-dialytic sudden cardiac arrest. We performed this study to examine the risks associated with dialysate calcium and serum-dialysate gradients among participants in the Evaluation of Cinacalcet Hydrochloride Therapy to Lower Cardiovascular Events (EVOLVE) trial. In EVOLVE, 3883 hemodialysis patients were randomized 1:1 to cinacalcet or placebo. Dialysate calcium was administered at the discretion of treating physicians. We examined whether baseline dialysate calcium concentration or the serum-dialysate calcium gradient modified the effect of cinacalcet on the following adjudicated endpoints: (1) primary composite endpoint (death or first non-fatal myocardial infarction, hospitalization for unstable angina, heart failure, or peripheral vascular event); (2) cardiovascular death; and (3) sudden death. In EVOLVE, use of higher dialysate calcium concentrations was more prevalent in Europe and Latin America compared with North America. There was a significant fall in serum calcium concentration in the cinacalcet group; dialysate calcium concentrations were changed infrequently in both groups. There was no association between baseline dialysate calcium concentration or serum-dialysate calcium gradient and the endpoints examined. Neither the baseline dialysate calcium nor the serum-dialysate calcium gradient significantly modified the effects of cinacalcet on the outcomes examined. The effects of cinacalcet on cardiovascular death and major cardiovascular events

  7. Kidney and calcium homeostasis.

    PubMed

    Jeon, Un Sil

    2008-12-01

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

  8. CADASIL patient with extracellular calcium deposits.

    PubMed

    Lewandowska, Eliza; Wierzba-Bobrowicz, Teresa; Buczek, Julia; Gromadzka, Grażyna; Dziewulska, Dorota

    2013-01-01

    We report the case of a 57-year-old male patient with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) diagnosed on the basis of ultrastructural and genetic examinations. Ultrastructurally, granular osmiophilic material (GOM) deposits, degeneration and loss of vascular smooth muscle cells (VSMC) and pericytes in small arterial and capillary vessels from skin-muscle biopsy typical of CADASIL were visible. Degeneration of pericytes and endothelial cells were often pronounced, which resulted in a complete disappearance of mural cells and extremely severe thickening of the basement membrane. Degenerative changes in blood vessels, especially evident in skeletal muscle arterioles, also included significant vacuolization of VSMC, misshapen nuclei both in vessel wall cells and skeletal muscle fibres, and deposits of a hyaline material and calcium in the vessel wall. Abundant calcium deposits were located in the vascular basement membrane and exhibited laminar morphology with abnormally arranged light and dark bands. In the basement membrane of the most severely affected microvessels, only clusters of calcium deposits and remnants of the mural cells were observed. Laminar calcifications were also observed within the basement membrane surrounding skeletal muscle fibres. Such abundant calcium deposits in CADASIL have not as yet been described. Morphological findings, described in this report, expand the spectrum of histopathological changes in this genetically determined angiopathy.

  9. Chromosomal abnormalities in human sperm

    SciTech Connect

    Martin, R.H.

    1985-01-01

    The ability to analyze human sperm chromosome complements after penetration of zona pellucida-free hamster eggs provides the first opportunity to study the frequency and type of chromosomal abnormalities in human gametes. Two large-scale studies have provided information on normal men. We have studied 1,426 sperm complements from 45 normal men and found an abnormality rate of 8.9%. Brandriff et al. (5) found 8.1% abnormal complements in 909 sperm from 4 men. The distribution of numerical and structural abnormalities was markedly dissimilar in the 2 studies. The frequency of aneuploidy was 5% in our sample and only 1.6% in Brandriff's, perhaps reflecting individual variability among donors. The frequency of 24,YY sperm was low: 0/1,426 and 1/909. This suggests that the estimates of nondisjunction based on fluorescent Y body data (1% to 5%) are not accurate. We have also studied men at increased risk of sperm chromosomal abnormalities. The frequency of chromosomally unbalanced sperm in 6 men heterozygous for structural abnormalities varied dramatically: 77% for t11;22, 32% for t6;14, 19% for t5;18, 13% for t14;21, and 0% for inv 3 and 7. We have also studied 13 cancer patients before and after radiotherapy and demonstrated a significant dose-dependent increase of sperm chromosome abnormalities (numerical and structural) 36 months after radiation treatment.

  10. Chromosomal abnormalities and mental illness.

    PubMed

    MacIntyre, D J; Blackwood, D H R; Porteous, D J; Pickard, B S; Muir, W J

    2003-03-01

    Linkage studies of mental illness have provided suggestive evidence of susceptibility loci over many broad chromosomal regions. Pinpointing causative gene mutations by conventional linkage strategies alone is problematic. The breakpoints of chromosomal abnormalities occurring in patients with mental illness may be more direct pointers to the relevant gene locus. Publications that describe patients where chromosomal abnormalities co-exist with mental illness are reviewed along with supporting evidence that this may amount to an association. Chromosomal abnormalities are considered to be of possible significance if (a) the abnormality is rare and there are independent reports of its coexistence with psychiatric illness, or (b) there is colocalisation of the abnormality with a region of suggestive linkage findings, or (c) there is an apparent cosegregation of the abnormality with psychiatric illness within the individual's family. Breakpoints have been described within many of the loci suggested by linkage studies and these findings support the hypothesis that shared susceptibility factors for schizophrenia and bipolar disorder may exist. If these abnormalities directly disrupt coding regions, then combining molecular genetic breakpoint cloning with bioinformatic sequence analysis may be a method of rapidly identifying candidate genes. Full karyotyping of individuals with psychotic illness especially where this coexists with mild learning disability, dysmorphism or a strong family history of mental disorder is encouraged.

  11. Haematological abnormalities in mitochondrial disorders

    PubMed Central

    Finsterer, Josef; Frank, Marlies

    2015-01-01

    INTRODUCTION This study aimed to assess the kind of haematological abnormalities that are present in patients with mitochondrial disorders (MIDs) and the frequency of their occurrence. METHODS The blood cell counts of a cohort of patients with syndromic and non-syndromic MIDs were retrospectively reviewed. MIDs were classified as ‘definite’, ‘probable’ or ‘possible’ according to clinical presentation, instrumental findings, immunohistological findings on muscle biopsy, biochemical abnormalities of the respiratory chain and/or the results of genetic studies. Patients who had medical conditions other than MID that account for the haematological abnormalities were excluded. RESULTS A total of 46 patients (‘definite’ = 5; ‘probable’ = 9; ‘possible’ = 32) had haematological abnormalities attributable to MIDs. The most frequent haematological abnormality in patients with MIDs was anaemia. 27 patients had anaemia as their sole haematological problem. Anaemia was associated with thrombopenia (n = 4), thrombocytosis (n = 2), leucopenia (n = 2), and eosinophilia (n = 1). Anaemia was hypochromic and normocytic in 27 patients, hypochromic and microcytic in six patients, hyperchromic and macrocytic in two patients, and normochromic and microcytic in one patient. Among the 46 patients with a mitochondrial haematological abnormality, 78.3% had anaemia, 13.0% had thrombopenia, 8.7% had leucopenia and 8.7% had eosinophilia, alone or in combination with other haematological abnormalities. CONCLUSION MID should be considered if a patient’s abnormal blood cell counts (particularly those associated with anaemia, thrombopenia, leucopenia or eosinophilia) cannot be explained by established causes. Abnormal blood cell counts may be the sole manifestation of MID or a collateral feature of a multisystem problem. PMID:26243978

  12. Haematological abnormalities in mitochondrial disorders.

    PubMed

    Finsterer, Josef; Frank, Marlies

    2015-07-01

    This study aimed to assess the kind of haematological abnormalities that are present in patients with mitochondrial disorders (MIDs) and the frequency of their occurrence. The blood cell counts of a cohort of patients with syndromic and non-syndromic MIDs were retrospectively reviewed. MIDs were classified as 'definite', 'probable' or 'possible' according to clinical presentation, instrumental findings, immunohistological findings on muscle biopsy, biochemical abnormalities of the respiratory chain and/or the results of genetic studies. Patients who had medical conditions other than MID that account for the haematological abnormalities were excluded. A total of 46 patients ('definite' = 5; 'probable' = 9; 'possible' = 32) had haematological abnormalities attributable to MIDs. The most frequent haematological abnormality in patients with MIDs was anaemia. 27 patients had anaemia as their sole haematological problem. Anaemia was associated with thrombopenia (n = 4), thrombocytosis (n = 2), leucopenia (n = 2), and eosinophilia (n = 1). Anaemia was hypochromic and normocytic in 27 patients, hypochromic and microcytic in six patients, hyperchromic and macrocytic in two patients, and normochromic and microcytic in one patient. Among the 46 patients with a mitochondrial haematological abnormality, 78.3% had anaemia, 13.0% had thrombopenia, 8.7% had leucopenia and 8.7% had eosinophilia, alone or in combination with other haematological abnormalities. MID should be considered if a patient's abnormal blood cell counts (particularly those associated with anaemia, thrombopenia, leucopenia or eosinophilia) cannot be explained by established causes. Abnormal blood cell counts may be the sole manifestation of MID or a collateral feature of a multisystem problem.

  13. Calcium Dyshomeostasis in Tubular Aggregate Myopathy

    PubMed Central

    Lee, Jong-Mok; Noguchi, Satoru

    2016-01-01

    Calcium is a crucial mediator of cell signaling in skeletal muscles for basic cellular functions and specific functions, including contraction, fiber-type differentiation and energy production. The sarcoplasmic reticulum (SR) is an organelle that provides a large supply of intracellular Ca2+ in myofibers. Upon excitation, it releases Ca2+ into the cytosol, inducing contraction of myofibrils. During relaxation, it takes up cytosolic Ca2+ to terminate the contraction. During exercise, Ca2+ is cycled between the cytosol and the SR through a system by which the Ca2+ pool in the SR is restored by uptake of extracellular Ca2+ via a specific channel on the plasma membrane. This channel is called the store-operated Ca2+ channel or the Ca2+ release-activated Ca2+ channel. It is activated by depletion of the Ca2+ store in the SR by coordination of two main molecules: stromal interaction molecule 1 (STIM1) and calcium release-activated calcium channel protein 1 (ORAI1). Recently, myopathies with a dominant mutation in these genes have been reported and the pathogenic mechanism of such diseases have been proposed. This review overviews the calcium signaling in skeletal muscles and role of store-operated Ca2+ entry in calcium homeostasis. Finally, we discuss the phenotypes and the pathomechanism of myopathies caused by mutations in the STIM1 and ORAI1 genes. PMID:27879676

  14. Diseases associated with calcium-sensing receptor.

    PubMed

    Vahe, C; Benomar, K; Espiard, S; Coppin, L; Jannin, A; Odou, M F; Vantyghem, M C

    2017-01-25

    The calcium-sensing receptor (CaSR) plays a pivotal role in systemic calcium metabolism by regulating parathyroid hormone secretion and urinary calcium excretion. The diseases caused by an abnormality of the CaSR are genetically determined or are more rarely acquired. The genetic diseases consist of hyper- or hypocalcemia disorders. Hypercalcaemia disorders are related to inactivating mutations of the CASR gene either heterozygous (autosomal dominant familial benign hypercalcaemia, still named hypocalciuric hypercalcaemia syndrome type 1) or homozygous (severe neonatal hyperparathyroidism). The A986S, R990G and Q1011E variants of the CASR gene are associated with higher serum calcium levels than in the general population, hypercalciuria being also associated with the R990G variant. The differential diagnosis consists in the hypocalciuric hypercalcaemia syndrome, types 2 (involving GNA11 gene) and 3 (involving AP2S1 gene); hyperparathyroidism; abnormalities of vitamin D metabolism, involving CYP24A1 and SLC34A1 genes; and reduced GFR. Hypocalcemia disorders, which are more rare, are related to heterozygous activating mutations of the CASR gene (type 1), consisting of autosomal dominant hypocalcemia disorders, sometimes with a presentation of pseudo-Bartter's syndrome. The differential diagnosis consists of the hypercalciuric hypocalcaemia syndrome type 2, involving GNA11 gene and other hypoparathyroidism aetiologies. The acquired diseases are related to the presence of anti-CaSR antibodies, which can cause hyper- or especially hypocalcemia disorders (for instance in APECED syndromes), determined by their functionality. Finally, the role of CaSR in digestive, respiratory, cardiovascular and neoplastic diseases is gradually coming to light, providing new therapeutic possibilities. Two types of CaSR modulators are known: CaSR agonists (or activators, still named calcimimetics) and calcilytic antagonists (or inhibitors of the CasR). CaSR agonists, such as cinacalcet

  15. Calcium and osteoporosis.

    PubMed

    Nordin, B E

    1997-01-01

    Calcium is an essential nutrient that is involved in most metabolic processes and the phosphate salts of which provide mechanical rigidity to the bones and teeth, where 99% of the body's calcium resides. The calcium in the skeleton has the additional role of acting as a reserve supply of calcium to meet the body's metabolic needs in states of calcium deficiency. Calcium deficiency is easily induced because of the obligatory losses of calcium via the bowel, kidneys, and skin. In growing animals, it may impair growth, delay consolidation of the skeleton, and in certain circumstances give rise to rickets but the latter is more often due to deficiency of vitamin D. In adult animals, calcium deficiency causes mobilization of bone and leads sooner or later to osteoporosis, i.e., a reduction in the "amount of bone in the bone" or apparent bone density. The effects of calcium deficiency and oophorectomy (ovariectomy) are additive. In humans, osteoporosis is a common feature of aging. Loss of bone starts in women at the time of the menopause and in men at about age 55 and leads to an increase in fracture rates in both sexes. Individual fracture risk is inversely related to bone density, which in turn is determined by the density achieved at maturity (peak bone density) and the subsequent rate of bone loss. At issue is whether either or both of these variables is related to calcium intake. The calcium requirement of adults may be defined as the mean calcium intake needed to preserve calcium balance, i.e., to meet the significant obligatory losses of calcium through the gastrointestinal tract, kidneys, and skin. The calcium allowance is the higher intake recommended for a population to allow for individual variation in the requirement. The mean requirement defined in this way, calculated from balance studies, is about 20 mmol (800 mg) a day on Western diets, implying an allowance of 25 mmol (1000 mg) or more. Corresponding requirements and allowances have been calculated for

  16. Bile salts and calcium absorption.

    PubMed

    Webling, D D; Holdsworth, E S

    1966-09-01

    1. The study of the effect of bile salts on enhancing calcium absorption in the rachitic chick has been extended to bile salts not present in chick bile, e.g. glycine conjugates and bile alcohol sulphates. 2. Bile and bile salts cause an increase in calcium absorption from sparingly soluble calcium hydrogen phosphate when compared with a suspension of calcium hydrogen phosphate in saline. 3. If the bile ducts of normal rats are tied the absorption of calcium from calcium hydrogen phosphate decreases but can be restored by giving bile salts with the calcium salt. 4. Bile salts increase solubility in water of the sparingly soluble calcium salts, phytate and phosphate at pH values between 6 and 8. 5. Bile salts increase the solubility in lipid solvents of calcium in approximately the same proportion as they increase the absorption of calcium from the gut. 6. The physiological role of bile in calcium absorption and its mode of action are discussed.

  17. Menstrual Cycle

    MedlinePlus

    ... receive Pregnancy email updates Enter email Submit The menstrual cycle Day 1 starts with the first day of ... drop around Day 25 . This signals the next menstrual cycle to begin. The egg will break apart and ...

  18. Disorders Involving Calcium, Phosphorus, and Magnesium

    PubMed Central

    Moe, Sharon M.

    2008-01-01

    Abnormalities of calcium, phosphorus and magnesium homeostasis are common, and collectively are called disorders of mineral metabolism. Normal homeostatic regulation maintains serum levels, intracellular levels, and optimal mineral content in bone. This regulation occurs at three major target organs, the intestine, kidney and bone, principally via the complex integration of two hormones, parathyroid hormone and vitamin D. An understanding of normal physiology is necessary to accurately diagnose and treat disorders of mineral metabolism and will be briefly reviewed before discussing the differential diagnosis and treatment of specific disorders. PMID:18486714

  19. Distal Renal Tubular Acidosis and Calcium Nephrolithiasis

    NASA Astrophysics Data System (ADS)

    Moe, Orson W.; Fuster, Daniel G.; Xie, Xiao-Song

    2008-09-01

    Calcium stones are commonly encountered in patients with congenital distal renal tubular acidosis, a disease of renal acidification caused by mutations in either the vacuolar H+-ATPase (B1 or a4 subunit), anion exchanger-1, or carbonic anhydrase II. Based on the existing database, we present two hypotheses. First, heterozygotes with mutations in B1 subunit of H+-ATPase are not normal but may harbor biochemical abnormalities such as renal acidification defects, hypercalciuria, and hypocitraturia which can predispose them to kidney stone formation. Second, we propose at least two mechanisms by which mutant B1 subunit can impair H+-ATPase: defective pump assembly and defective pump activity.

  20. Skin - abnormally dark or light

    MedlinePlus

    ... ency/article/003242.htm Skin - abnormally dark or light To use the sharing features on this page, ... the hands. The bronze color can range from light to dark (in fair-skinned people) with the ...

  1. In vivo impact of presynaptic calcium channel dysfunction on motor axons in episodic ataxia type 2.

    PubMed

    Tomlinson, Susan E; Tan, S Veronica; Burke, David; Labrum, Robyn W; Haworth, Andrea; Gibbons, Vaneesha S; Sweeney, Mary G; Griggs, Robert C; Kullmann, Dimitri M; Bostock, Hugh; Hanna, Michael G

    2016-02-01

    Ion channel dysfunction causes a range of neurological disorders by altering transmembrane ion fluxes, neuronal or muscle excitability, and neurotransmitter release. Genetic neuronal channelopathies affecting peripheral axons provide a unique opportunity to examine the impact of dysfunction of a single channel subtype in detail in vivo. Episodic ataxia type 2 is caused by mutations in CACNA1A, which encodes the pore-forming subunit of the neuronal voltage-gated calcium channel Cav2.1. In peripheral motor axons, this channel is highly expressed at the presynaptic neuromuscular junction where it contributes to action potential-evoked neurotransmitter release, but it is not expressed mid-axon or thought to contribute to action potential generation. Eight patients from five families with genetically confirmed episodic ataxia type 2 underwent neurophysiological assessment to determine whether axonal excitability was normal and, if not, whether changes could be explained by Cav2.1 dysfunction. New mutations in the CACNA1A gene were identified in two families. Nerve conduction studies were normal, but increased jitter in single-fibre EMG studies indicated unstable neuromuscular transmission in two patients. Excitability properties of median motor axons were compared with those in 30 age-matched healthy control subjects. All patients had similar excitability abnormalities, including a high electrical threshold and increased responses to hyperpolarizing (P < 0.00007) and depolarizing currents (P < 0.001) in threshold electrotonus. In the recovery cycle, refractoriness (P < 0.0002) and superexcitability (P < 0.006) were increased. Cav2.1 dysfunction in episodic ataxia type 2 thus has unexpected effects on axon excitability, which may reflect an indirect effect of abnormal calcium current fluxes during development. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved.

  2. In vivo impact of presynaptic calcium channel dysfunction on motor axons in episodic ataxia type 2

    PubMed Central

    Tan, S. Veronica; Burke, David; Labrum, Robyn W.; Haworth, Andrea; Gibbons, Vaneesha S.; Sweeney, Mary G.; Griggs, Robert C.; Kullmann, Dimitri M.; Bostock, Hugh; Hanna, Michael G.

    2016-01-01

    Ion channel dysfunction causes a range of neurological disorders by altering transmembrane ion fluxes, neuronal or muscle excitability, and neurotransmitter release. Genetic neuronal channelopathies affecting peripheral axons provide a unique opportunity to examine the impact of dysfunction of a single channel subtype in detail in vivo. Episodic ataxia type 2 is caused by mutations in CACNA1A, which encodes the pore-forming subunit of the neuronal voltage-gated calcium channel Cav2.1. In peripheral motor axons, this channel is highly expressed at the presynaptic neuromuscular junction where it contributes to action potential-evoked neurotransmitter release, but it is not expressed mid-axon or thought to contribute to action potential generation. Eight patients from five families with genetically confirmed episodic ataxia type 2 underwent neurophysiological assessment to determine whether axonal excitability was normal and, if not, whether changes could be explained by Cav2.1 dysfunction. New mutations in the CACNA1A gene were identified in two families. Nerve conduction studies were normal, but increased jitter in single-fibre EMG studies indicated unstable neuromuscular transmission in two patients. Excitability properties of median motor axons were compared with those in 30 age-matched healthy control subjects. All patients had similar excitability abnormalities, including a high electrical threshold and increased responses to hyperpolarizing (P < 0.00007) and depolarizing currents (P < 0.001) in threshold electrotonus. In the recovery cycle, refractoriness (P < 0.0002) and superexcitability (P < 0.006) were increased. Cav2.1 dysfunction in episodic ataxia type 2 thus has unexpected effects on axon excitability, which may reflect an indirect effect of abnormal calcium current fluxes during development. PMID:26912519

  3. [Calcium and health].

    PubMed

    Ortega Anta, Rosa M; Jiménez Ortega, Ana I; López-Sobaler, Ana M

    2015-04-07

    An adequate intake of calcium is only not limited to avoid the risk of osteoporosis and its benefits in longterm bone health, but also it has been linked to protection against various major diseases, such as hypertension, cancer, kidney stones, insulin resistance, diabetes... and several investigations suggest its importance in preventing and controlling obesity. Studies conducted in Spanish representative samples show that a high percentage of adults and children (> 75%) don't achieve the recommended intake of calcium. Moreover, are growing trends among the population suggesting that calcium intake and dairy consumption (main food source of the mineral) are high, and even excessive, in many individuals. This misconception results in that the calcium intake is increasingly far from the recommended one. The maximum tolerable intake of the mineral is fixed at 2.500 mg/day, but this intake is unusual, and it's more disturbing and frequent, to find intakes below the recommended calcium intakes (1.000 and 1.200 mg/day in adults, men and women, respectively). Data from different studies highlight the risk of an inadequate calcium intake and the damages that may affect the health in a long term. It is not about transmitting indiscriminate guidelines in order to increase the intake of calcium / dairy, but the recommended intakes must be met to achieve both the nutritional and health benefits. Also activities for demystification of misconceptions are need, increasingly frequent, that may impair health population.

  4. Calcium Signaling and Neurodegeneration

    PubMed Central

    2010-01-01

    Neurodegenerative disorders, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), Huntington’s disease (HD), and spinocerebellar ataxias (SCA) are very important both for fundamental science and for practical medicine. Despite extensive research into the causes of these diseases, clinical researchers have had very limited progress and, as of now, there is still no cure for any of these diseases. One of the main obstacles in the way of creating treatments for these disorders is the fact that their etiology and pathophysiology still remain unclear. This paper reviews results that support the so–called “calcium hypothesis of neurodegenerative diseases.” The calcium hypothesis states that the atrophic and degenerative processes in the neurons of AD, PD, ALS, HD, and SCA patients are accompanied by alterations in calcium homeostasis. Moreover, the calcium hypothesis states that this deregulation of calcium signaling is one of the early–stage and key processes in the pathogenesis of these diseases. Based on the results we reviewed, we conclude that the calcium channels and other proteins involved in the neuronal calcium signaling system are potential drug targets for AD, PD, ALS, HD, and SCA therapy. PMID:22649630

  5. [Seizures revealing phosphocalcic metabolism abnormalities].

    PubMed

    Hmami, F; Chaouki, S; Benmiloud, S; Souilmi, F Z; Abourazzak, S; Idrissi, M; Atmani, S; Bouharrou, A; Hida, M

    2014-01-01

    Hypocalcemia due to hypoparathyroidism produces a broad spectrum of clinical manifestations, but overt symptoms may be sparse. One unusual presentation is onset or aggravation of epilepsy in adolescence revealing hypoparathyroidism. This situation can lead to delayed diagnosis, with inefficacity of the antiepileptic drugs. We report five cases of adolescence-onset epilepsy with unsuccessful antiepileptic therapy, even with gradually increasing dose. Physical examination revealed signs of hypocalcemia, confirmed biologically. Full testing disclosed the origin of the seizures: hypoparathyroidism in three patients and pseudohypoparathyroidism in the other two. In four of five patients, computed tomography showed calcification of the basal ganglia, defining Fahr's syndrome. The patients were treated with oral calcium and active vitamin D (1-alphahydroxy vitamin D3). Seizure frequency progressively decreased and serum calcium levels returned to normal. These cases illustrate the importance of the physical examination and of routine serum calcium assay in patients with new-onset epileptic seizures in order to detect hypocalcemia secondary to hypoparathyroidism.

  6. Congenital abnormalities and selective abortion.

    PubMed

    Seller, M J

    1976-09-01

    The technique of amniocentesis, by which an abnormal fetus can be detected in utero, has brought a technological advance in medical science but attendant medical and moral problems. Dr Seller describes those congenital disabilities which can be detected in the fetus before birth, for which the "remedy" is selective abortion. She then discusses the arguments for and against selective abortion, for the issue is not simple, even in the strictly genetic sense of attempting to ensure a population free of congenital abnormality.

  7. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  8. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  9. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  10. 21 CFR 184.1191 - Calcium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium chloride in the “Calcium...

  11. CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT OF CENTER WITH TOP OF SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  12. Calcium dynamics during NMDA-induced membrane potential oscillations in lamprey spinal neurons--contribution of L-type calcium channels (CaV1.3).

    PubMed

    Wang, Di; Grillner, Sten; Wallén, Peter

    2013-05-15

      NMDA receptor-dependent, intrinsic membrane potential oscillations are an important element in the operation of the lamprey locomotor network. They involve a cyclic influx of calcium, leading to an activation of calcium-activated potassium (KCa) channels that in turn contributes to the termination of the depolarized plateau and membrane repolarization. In this study, we have investigated the calcium dynamics in different regions of lamprey spinal neurons during membrane potential oscillations, using confocal calcium imaging in combination with intracellular recordings. Calcium fluctuations were observed in both soma and dendrites, timed to the oscillations. The calcium level increased sharply at the onset of membrane depolarization, to reach its maximum by the end of the plateau. The calcium peak in distal dendrites typically occurred earlier than in the soma during the oscillatory cycle. The L-type calcium channel blocker nimodipine increased the duration of the depolarized plateau phase in most cells tested, whereas the agonist Bay K 8644 decreased plateau duration. Bay K 8644 increased the amplitude of calcium fluctuations, particularly in distal dendrites, whereas nimodipine caused a decrease, suggesting that L-type low-voltage-activated calcium channels are mainly localized in these regions. Our results thus indicate that dendritic CaV1.3-like calcium channels are activated during NMDA-mediated membrane potential oscillations. This calcium influx activates KCa channels involved in plateau termination.

  13. [Management of abnormal bleeding in an intrauterine device user].

    PubMed

    Desmons, F; Adam-steen, C

    1985-01-01

    Abnormal uterine bleeding is the most common complication of IUD use. Minor metrorrhagia during the insertion and the initial 2 or 3 cycles is common and has no pathological significance. The true complications are menorrhagia, or augmentation of the volume of blood, and metrorrhagia, or repeated intermenstrual bleeding. Inert IUDs increase the volume of menstrual blood loss by 100-140% and copper devices by 50-60%. Blood loss is directly related to the size and form of the IUD; copper devices cause less bleeding primarily because of their reduced surface area. Anemia secondary to menstrual problems is a serious problem in developing countries. Metrorrhagia in IUD users is often associated with pain and may lead to removal of the device. It may result from the same array of morphological and functional modifications of the endometrium as menorrhagia, but more often it signals a true complication, either utero-adnexal infection, an intra- or extrauterine pregnancy or spontaneous abortion, or an inadaptation to the uterine cavity or a displacement of the IUD, perhaps with perforation. Metrorrhagia may also result from appearance of a calcium deposit on the surface of an IUD in place for over 2 years, or it may reveal a pathology unrelated to the IUD, such as a myoma, polyp, endometrial hyperplasia, or adenomyosis. Menorrhagia is an almost inevitable consequence of IUD use, but metrorrhagia requires close surveillance. A clinical examination aided by diagnostic tests is needed to distinguish between complications requiring immediate treatment and simple intolerances that may spontaneously resolve. Sonography is indispensable, to confirm good placement of the IUD or to rule out uterine anomalies or pregnancy. Hysteroscopy can be performed with the IUD in place or not, to diagnose localized endometrial hyperplasias, polyps, poorly positioned IUDs, or partial or complete perforations. Hysterography after infection and pregnancy have been ruled out can reveal endocavity

  14. Urine risk factors in children with calcium kidney stones and their siblings

    PubMed Central

    Bergsland, Kristin J.; Coe, Fredric L.; White, Mark D.; Erhard, Michael J.; DeFoor, William R.; Mahan, John D.; Schwaderer, Andrew L.; Asplin, John R.

    2012-01-01

    Calcium nephrolithiasis in children is increasing in prevalence and tends to be recurrent. Although children have a lower incidence of nephrolithiasis than adults, its etiology in children is less well understood; hence treatments targeted for adults may not be optimal in children. To better understand metabolic abnormalities in stone forming children, we compared chemical measurements and the crystallization properties of 24-hour urine collections from 129 stone formers matched to 105 non-stone forming siblings and 183 normal, healthy children with no family history of stones; all aged 6 to 17 years. The principal risk factor for calcium stone formation was hypercalciuria. Stone formers have strikingly higher calcium excretion along with high supersaturation for calcium oxalate and calcium phosphate, and a reduced distance between the upper limit of metastability and supersaturation for calcium phosphate, indicating increased risk of calcium phosphate crystallization. Other differences in urine chemistry that exist between adult stone formers and normal individuals such as hyperoxaluria, hypocitraturia, abnormal urine pH and low urine volume were not found in these children. Hence, hypercalciuria and a reduction in the gap between calcium phosphate upper limit of metastability and supersaturation are crucial determinants of stone risk. This highlights the importance of managing hypercalciuria in children with calcium stones. PMID:22358148

  15. Pure hemidystonia with basal ganglion abnormalities on positron emission tomography

    SciTech Connect

    Perlmutter, J.S.; Raichle, M.E.

    1984-03-01

    We present a patient with hemidystonia and an abnormality of the contralateral basal ganglion seen only with positron emission tomography. A 50-year-old sinistral man suffered minor trauma to the right side of his head and neck. Within 20 minutes he developed paroxysmal intermittent dystonic posturing of his right face, forearm, hand, and foot, with weaker contractions of the left foot, lasting several seconds and recurring every few minutes. Neurological findings between spells were normal. The following were also normal: electrolyte, calcium, magnesium, and arterial blood gas levels, and findings of drug screen, cerebrospinal fluid examination, electroencephalography with nasopharyngeal leads, computed tomographic scanning (initially and four weeks later), and cerebral angiography. Positron emission tomographic scanning revealed abnormalities in the left basal ganglion region, including decreased oxygen metabolism, decreased oxygen extraction, increased blood volume, and increased blood flow.

  16. Stoichiometry of Calcium Medicines

    ERIC Educational Resources Information Center

    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.

  17. Get Enough Calcium

    MedlinePlus

    ... like: Fat-free or low-fat (1%) milk, yogurt, and cheese Soymilk with added calcium Broccoli and ... Milk with added vitamin D Some breakfast cereals, yogurt, and juices with added vitamin D Mushrooms Vitamin ...

  18. Stoichiometry of Calcium Medicines

    ERIC Educational Resources Information Center

    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.

  19. Calcium and bones

    MedlinePlus

    ... Your body also needs calcium (as well as phosphorus) to make healthy bones. Bones are the main ... nlm.nih.gov/pubmed/25182228 . De Paula FJA, Black DM, Rosen CJ. Osteoporosis and bone biology. In: ...

  20. Calcium-D-glucarate.

    PubMed

    2002-08-01

    Calcium-D-glucarate is the calcium salt of D-glucaric acid, a substance produced naturally in small amounts by mammals, including humans. Glucaric acid is also found in many fruits and vegetables with the highest concentrations to be found in oranges, apples, grapefruit, and cruciferous vegetables. Oral supplementation of calcium-D-glucarate has been shown to inhibit beta-glucuronidase, an enzyme produced by colonic microflora and involved in Phase II liver detoxification. Elevated beta-glucuronidase activity is associated with an increased risk for various cancers, particularly hormone-dependent cancers such as breast, prostate, and colon cancers. Other potential clinical applications of oral calcium-D-glucarate include regulation of estrogen metabolism and as a lipid-lowering agent.

  1. Coronary Calcium Scan

    MedlinePlus

    ... Intramural Research Research Resources Research Meeting Summaries Technology ... complete. A coronary calcium scan uses a special scanner such as an electron beam CT or a multidetector CT (MDCT) machine. ...

  2. [Diagnosticum of abnormalities of plant meiotic division].

    PubMed

    Shamina, N V

    2006-01-01

    Abnormalities of plant meiotic division leading to abnormal meiotic products are summarized schematically in the paper. Causes of formation of monads, abnormal diads, triads, pentads, polyads, etc. have been observed in meiosis with both successive and simultaneous cytokinesis.

  3. Drug-induced abnormalities of potassium metabolism.

    PubMed

    Kokot, Franciszek; Hyla-Klekot, Lidia

    2008-01-01

    Pharmacotherapy has progressed rapidly over the last 20 years with the result that general practioners more and more often use drugs which may influence potassium metabolism at the kidney or gastrointestinal level, or the transmembrane transport of potassium at the cellular level. Potassium abnormalities may result in life-theatening clinical conditions. Hypokalemia is most frequently caused by renal loss of this electrolyte (thiazide, thiazide-like and loop diuretics, glucocorticoids) and the gastrointestinal tract (laxatives, diarrhea, vomiting, external fistula), and may be the result of an increased intracellular potassium influx induced by sympathicomimetics used mostly by patients with asthma, or by insulin overdosage in diabetic subjects. The leading symptoms of hypokalemia are skeletal and smooth muscle weakness and cardiac arrhythmias. Hyperkalemia may be caused by acute or end-stage renal failure, impaired tubular excretion of potassium (blockers of the renin-angiotensin-aldosterone system, nonsteroidal anti-inflammatory drugs, cyclosporine, antifungal drugs, potassium sparing diuretics), acidemia, and severe cellular injury (tumor lysis syndrome). Hyperkalemia may be the cause of severe injury of both skeletal and smooth muscle cells. The specific treatment counteracting hyperkalemia is a bolus injection of calcium salts and, when necessary, hemodialysis.

  4. Normal calcium homeostasis in dystrophin-expressing facioscapulohumeral muscular dystrophy myotubes.

    PubMed

    Vandebrouck, Clarisse; Imbert, Nathalie; Constantin, Bruno; Duport, Gérard; Raymond, Guy; Cognard, Christian

    2002-03-01

    The aim of this study was to provide a set of data on mechanisms involved in the calcium homeostasis of facioscapulohumeral muscular dystrophy (FSHD) co-cultured myotubes. In fact, abnormal regulation of calcium have been shown in deficient dystrophin cells like Duchenne muscular dystrophy (DMD) cells, and it seemed interesting to study the calcium regulation in a pathologic cellular model which express dystrophin. T- and L-type calcium currents and contractile responses induced by membrane depolarisations as well as intracellular calcium transients induced by three kinds of stimulus (superfusions of acetylcholine, high K+ or caffeine containing media) were recorded by means of whole-cell patch-clamp and ratiometric cytofluorimetry in co-cultured FSHD myotubes which presented a sarcolemmal localisation of dystrophin. As judged from calcium currents properties, voltage-dependency of contractile responses or amplitude of evoked calcium transients, no clear difference in the calcium handling or calcium signalling was observed between this type of cell and the control cells, at least with the means and the conditions used in the present study. Since FSHD cells, contrary to DMD (Duchenne muscular dystrophy) cells, seemed to display both dystrophin expression and unaltered calcium regulation, the FSHD co-cultured cells appeared as a useful model of dystrophin-expressing pathological muscle cells to further investigate the link between dystrophin expression and intracellular calcium level regulation.

  5. Oxidative calcium release from catechol.

    PubMed

    Riley, Patrick A; Stratford, Michael R L

    2015-04-01

    Oxidation of 4-methylcatechol previously exposed to aqueous calcium chloride was shown by ion chromatography to be associated with release of calcium ions. The catechol was oxidised to the corresponding orthoquinone by the use of tyrosinase from Agaricus bisporus. The oxidative release of calcium from the catechol is ascribed to the diminution of the available hydroxyl functions able to act as chelating groups. Our results suggest that the redox status of melanin may regulate calcium binding and influence calcium levels in pigmented cells.

  6. Complex patterns of abnormal heartbeats

    NASA Technical Reports Server (NTRS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

    2002-01-01

    Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

  7. Complex patterns of abnormal heartbeats

    NASA Technical Reports Server (NTRS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

    2002-01-01

    Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

  8. Complex patterns of abnormal heartbeats

    NASA Astrophysics Data System (ADS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch.; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

    2002-09-01

    Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical ``heartprints'' which reveal characteristic patterns in long clinical records encompassing ~105 heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

  9. Abnormal insulin levels and vertigo.

    PubMed

    Proctor, C A

    1981-10-01

    Fifty patients with unexplained vertigo (36) or lightheadedness (14) are evaluated, all of whom had abnormal ENGs and normal audiograms. Five hour insulin glucose tolerance tests were performance on all patients, with insulin levels being obtained fasting and at one-half, one, two, and three hours. The results of this investigation were remarkable. Borderline or abnormal insulin levels were discovered in 82% of patients; 90% were found to have either an abnormal glucose tolerance test or at least borderline insulin levels. The response to treatment in these dizzy patients was also startling, with appropriate low carbohydrate diets improving the patient's symptoms in 90% of cases. It is, therefore, apparent that the earliest identification of carbohydrate imbalance with an insulin glucose tolerance test is extremely important in the work-up of the dizzy patients.

  10. T-Type Calcium Channel: A Privileged Gate for Calcium Entry and Control of Adrenal Steroidogenesis.

    PubMed

    Rossier, Michel F

    2016-01-01

    Intracellular calcium plays a crucial role in modulating a variety of functions such as muscle contraction, hormone secretion, gene expression, or cell growth. Calcium signaling has been however shown to be more complex than initially thought. Indeed, it is confined within cell microdomains, and different calcium channels are associated with different functions, as shown by various channelopathies. Sporadic mutations on voltage-operated L-type calcium channels in adrenal glomerulosa cells have been shown recently to be the second most prevalent genetic abnormalities present in human aldosterone-producing adenoma. The observed modification of the threshold of activation of the mutated channels not only provides an explanation for this gain of function but also reminds us on the importance of maintaining adequate electrophysiological characteristics to make channels able to exert specific cellular functions. Indeed, the contribution to steroid production of the various calcium channels expressed in adrenocortical cells is not equal, and the reason has been investigated for a long time. Given the very negative resting potential of these cells, and the small membrane depolarization induced by their physiological agonists, low threshold T-type calcium channels are particularly well suited for responding under these conditions and conveying calcium into the cell, at the right place for controlling steroidogenesis. In contrast, high threshold L-type channels are normally activated by much stronger cell depolarizations. The fact that dihydropyridine calcium antagonists, specific for L-type channels, are poorly efficient for reducing aldosterone secretion either in vivo or in vitro, strongly supports the view that these two types of channels differently affect steroid biosynthesis. Whether a similar analysis is transposable to fasciculata cells and cortisol secretion is one of the questions addressed in the present review. No similar mutations on L-type or T-type channels

  11. Ectodermal dysplasia and abnormal thumbs.

    PubMed

    Lucky, A W; Esterly, N B; Tunnessen, W W

    1980-05-01

    Two unrelated children, a girl and a boy, with alopecia, anomalous cutaneous pigmentation, abnormal thumbs, and endocrine disorders, including short stature and delayed bone age in one patient and juvenile onset diabetes mellitus in the other, are described. In one instance, the mother and the maternal grandmother had similar abnormalities, although of a less severe nature. Both children had normal nails and no unusual susceptibility to infections. We believe these two patients represent a previously undescribed syndrome of ectodermal dysplasia that may be inherited as an autosomal-dominant trait.

  12. Lipopolysaccharides upregulate calcium concentration in mouse uterine smooth muscle cells through the T-type calcium channels.

    PubMed

    Zhang, Lijuan; Wang, Lin; Jiang, Jingyi; Zheng, Dongming; Liu, Sishi; Liu, Caixia

    2015-03-01

    Infection is a significant cause of preterm birth. Abnormal changes in intracellular calcium signals are the ultimate triggers of early uterine contractions that result in preterm birth. T‑type calcium channels play an important role in the pathogenesis of cancer, as well as endocrine and cardiovascular diseases. However, there are limited studies on their role in uterine contractions and parturition. In the present study, mouse uterine smooth muscle cells were isolated and treated with lipopolysaccharides (LPS) to mimic the microenvironment of uterine infection in vitro to investigate the role of T‑type calcium channels in the process of infection‑induced preterm birth. The results from quantitative polymerase chain reaction and western blot analysis showed that LPS significantly induced the expression of the Cav3.1 and Cav3.2 subtypes of T‑type calcium channels. Measurements of intracellular calcium concentration showed a significant increase in response to LPS. However, these effects can be reversed by T‑type calcium channel blockers. Western blot analysis further indicated that LPS induced the activation of the nuclear factor (NF)‑κB signaling pathway, and endothelin‑1 (ET‑1) was significantly upregulated, whereas NF‑κB inhibitors significantly inhibited the LPS‑induced upregulation of Cav3.1, Cav3.2 and ET‑1 expression. In addition, ET‑1 directly induced Cav3.1 and Cav3.2 expression, whereas ET‑1 antagonists inhibited the LPS‑induced upregulation of Cav3.1 and Cav3.2 expression. In conclusion, the present study demonstrates that infection triggers the upregulation of T‑type calcium channels and promotes calcium influx. This process relies on the activation of the NF‑κB/ET‑1 signaling pathway. The T‑type calcium channel is expected to become an effective target for the prevention of infection‑induced preterm birth.

  13. Collective Calcium Signaling of Defective Multicellular Networks

    NASA Astrophysics Data System (ADS)

    Potter, Garrett; Sun, Bo

    2015-03-01

    A communicating multicellular network processes environmental cues into collective cellular dynamics. We have previously demonstrated that, when excited by extracellular ATP, fibroblast monolayers generate correlated calcium dynamics modulated by both the stimuli and gap junction communication between the cells. However, just as a well-connected neural network may be compromised by abnormal neurons, a tissue monolayer can also be defective with cancer cells, which typically have down regulated gap junctions. To understand the collective cellular dynamics in a defective multicellular network we have studied the calcium signaling of co-cultured breast cancer cells and fibroblast cells in various concentrations of ATP delivered through microfluidic devices. Our results demonstrate that cancer cells respond faster, generate singular spikes, and are more synchronous across all stimuli concentrations. Additionally, fibroblast cells exhibit persistent calcium oscillations that increase in regularity with greater stimuli. To interpret these results we quantitatively analyzed the immunostaining of purigenic receptors and gap junction channels. The results confirm our hypothesis that collective dynamics are mainly determined by the availability of gap junction communications.

  14. Calcium metabolism and correcting calcium deficiencies.

    PubMed

    Emkey, Ronald D; Emkey, Gregory R

    2012-09-01

    Calcium is the most abundant cation in the human body, of which approximately 99% occurs in bone, contributing to its rigidity and strength. Bone also functions as a reservoir of Ca for its role in multiple physiologic and biochemical processes. This article aims to provide a thorough understanding of the absorptive mechanisms and factors affecting these processes to enable one to better appreciate an individual's Ca needs, and to provide a rationale for correcting Ca deficiencies. An overview of Ca requirements and suggested dosing regimens is presented, with discussion of various Ca preparations and potential toxicities of Ca treatment.

  15. Vestibular abnormalities in congenital disorders.

    PubMed

    Sando, I; Orita, Y; Miura, M; Balaban, C D

    2001-10-01

    This paper reviews the histopathologic features of vestibular abnormalities in congenital disorders affecting the inner ear, based upon a comprehensive literature survey and a review of cases in our temporal bone collection. The review proceeds in three systematic steps. First, we surveyed associated diseases with the major phenotypic features of congenital abnormalities of the inner ear (including the internal auditory canal and otic capsule). Second, the vestibular anomalies are examined specifically. Finally, the anomalies are discussed from a developmental perspective. Among vestibular anomalies, a hypoplastic endolymphatic duct and sac are observed most frequently. Anomalies of the semicircular canals are also often observed. From embryological and clinical viewpoints, many of these resemble the structural features from fetal stages and appear to be associated with vestibular dysfunction. It is expected that progress in genetic analysis and accumulation of temporal bone specimens with vestibular abnormalities in congenital diseases will provide crucial information not only for pathology of those diseases, but also for genetic factors that are responsible for the specific vestibular abnormalities.

  16. Inositol trisphosphate and calcium signalling

    NASA Astrophysics Data System (ADS)

    Berridge, Michael J.

    1993-01-01

    Inositol trisphosphate is a second messenger that controls many cellular processes by generating internal calcium signals. It operates through receptors whose molecular and physiological properties closely resemble the calcium-mobilizing ryanodine receptors of muscle. This family of intracellular calcium channels displays the regenerative process of calcium-induced calcium release responsible for the complex spatiotemporal patterns of calcium waves and oscillations. Such a dynamic signalling pathway controls many cellular processes, including fertilization, cell growth, transformation, secretion, smooth muscle contraction, sensory perception and neuronal signalling.

  17. Calcium transport mechanisms in muskrat and rat hearts.

    PubMed

    McKean, T A

    2001-11-01

    Mammalian hearts experience calcium overload during extreme and prolonged hypoxia and the calcium overload may lead to enzyme activation and cell death. Several calcium transport systems were examined in muskrat hearts and compared to those found in rat hearts to determine if there is a species difference that might be related to the muskrats' superior ability to survive hypoxia. Radiolabeled nitredendipine binding was determined in rat and muskrat hearts to estimate the density of voltage gated calcium channels in surface membranes. There were no species differences. Calcium release channel density in the sarcoplasmic reticulum was estimated by the determination of radiolabeled ryanodine binding in muskrat and rat heart SR membranes. No differences were revealed between species. The SR uptake of calcium was measured in SR membranes from the hearts of the two species. No differences were found in the B(max) values, however, the muskrat SR membranes did have a slightly lower K(m) value. There were large species differences in Na(+)/Ca(2+) exchange in SL membranes with the muskrat heart having approximately 3.5 times the transport capacity of rat SL membranes. During hypoxic conditions in which there is extensive ATP depletion leading to [Na(+)](i) accumulation and discharge of cellular membrane potential, the Na(+)/Ca(2+) exchanger may operate in the reverse mode and import calcium into the cell and accelerate hypoxic damage. Prior to reaching this state a robust Na(+)/Ca(2+) exchange would facilitate the maintenance of normal diastolic calcium levels and calcium cycling. Muskrats hearts are hypoxia tolerant by virtue of their ability to reduce metabolic demand and generate ATP anaerobically thus, maintaining a favorable ATP balance. Therefore, the relative overexpression of Na(+)/Ca(2+) exchangers in muskrat hearts may be beneficial in the preservation of contractile function and calcium homeostasis in this freshwater diving mammal.

  18. Calcium revisited: part I

    PubMed Central

    Burckhardt, Peter

    2013-01-01

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

  19. Calcium revisited: part I.

    PubMed

    Burckhardt, Peter

    2013-10-16

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

  20. Gravimetric Determination of Calcium as Calcium Carbonate Hydrate.

    ERIC Educational Resources Information Center

    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. Gravimetric Determination of Calcium as Calcium Carbonate Hydrate.

    ERIC Educational Resources Information Center

    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)

  2. Calcium and voltage imaging in arrhythmia models by high-speed microscopy

    NASA Astrophysics Data System (ADS)

    de Mauro, C.; Cecchetti, C. A.; Alfieri, D.; Borile, G.; Urbani, A.; Mongillo, M.; Pavone, F. S.

    2014-03-01

    Alterations in intracellular cardiomyocyte calcium handling have a key role in initiating and sustaining arrhythmias. Arrhythmogenic calcium leak from sarcoplasmic reticulum (SR) can be attributed to all means by which calcium exits the SR store in an abnormal fashion. Abnormal SR calcium exit maymanifest as intracellular Ca2+ sparks and/or Ca2+ waves. Ca2+ signaling in arrhythmogenesis has been mainly studied in isolated cardiomyocytes and given that the extracellular matrix influences both Ca2+ and membrane potential dynamics in the intact heart and underlies environmentally mediated changes, understanding how Ca2+ and voltage are regulated in the intact heart will represent a tremendous advancement in the understanding of arrhythmogenic mechanisms. Using novel high-speed multiphoton microscopy techinques, such as multispot and random access, we investigated animal models with inherited and acquired arrhythmias to assess the role of Ca2+ and voltage signals as arrhythmia triggers in cell and subcellular components of the intact heart and correlate these with electrophysiology.

  3. [Calcium distribution in fertile and sterile anthers of a genic male sterile Chinese cabbage].

    PubMed

    Xie, Chao-Tian; Yang, Yan-Hong; Qiu, Yi-Lan; Ge, Li-Li; Tian, Hui-Qiao

    2005-12-01

    Potassium antimonite was used to locate calcium in the fertile and sterile anthers of a genic male sterile Chinese cabbage (Brassica campestris L. ssp. chinensis Makino) to probe the relation between Ca(2+) and fertility and sterility of anthers of the cabbage. During fertile anther development, calcium granules increase in number in anther wall cells after meiosis, and then appeared also in locule, suggesting a calcium influx into locule from anther wall cells (Plate I-4). Then the number of calcium granules in microspore cytoplasm also increased at early stage (Plate II-1), accumulated mainly on the membrane of small vacuoles which were fusing to form big ones to make a polarity in the cell and to prepare asymmetric division of microspore (Plate II-3,4). After microspore division and the big vacuole decomposition, many calcium granules accumulated again on the membrane of the vacuoles (Plate III-1,2), displaying calcium regulates vacuole formation and decomposition during pollen development. In sterile anthers, abnormal distribution of calcium granules first appeared in callus wall of microspore mother cell (Plate IV-1). However, only a few calcium granules appeared in early microspores, which then could not form small vacuoles and finally a big vacuole (Plate IV-2,3). The aborting microspores degenerate by cytoplasm shrinking (Plate IV-5,6). The difference pattern of distribution of calcium granules between the fertile and sterile anthers indicates that anomalies in the distribution of calcium accumulation are correlated with the failure of pollen development and pollen abortion.

  4. Calcium metabolism in microgravity.

    PubMed

    Heer, M; Kamps, N; Biener, C; Korr, C; Boerger, A; Zittermann, A; Stehle, P; Drummer, C

    1999-09-09

    Unloading of weight bearing bones as induced by microgravity or immobilization has significant impacts on the calcium and bone metabolism and is the most likely cause for space osteoporosis. During a 4.5 to 6 month stay in space most of the astronauts develop a reduction in bone mineral density in spine, femoral neck, trochanter, and pelvis of 1%-1.6% measured by Dual Energy X-ray Absorption (DEXA). Dependent on the mission length and the individual turnover rates of the astronauts it can even reach individual losses of up to 14% in the femoral neck. Osteoporosis itself is defined as the deterioration of bone tissue leading to enhanced bone fragility and to a consequent increase in fracture risk. Thinking of long-term missions to Mars or interplanetary missions for years, space osteoporosis is one of the major concerns for manned spaceflight. However, decrease in bone density can be initiated differently. It either can be caused by increases in bone formation and bone resorption resulting in a net bone loss, as obtained in fast looser postmenopausal osteoporosis. On the other hand decrease in bone formation and increase in bone resorption also leads to bone losses as obtained in slow looser postmenopausal osteoporosis or in Anorexia Nervosa patients. Biomarkers of bone turnover measured during several missions indicated that the pattern of space osteoporosis is very similar to the pattern of Anorexia Nervosa patients or slow looser postmenopausal osteoporosis. However, beside unloading, other risk factors for space osteoporosis exist such as stress, nutrition, fluid shifts, dehydration and bone perfusion. Especially nutritional factors may contribute considerably to the development of osteoporosis. From earthbound studies it is known that calcium supplementation in women and men can prevent bone loss of 1% bone per year. Based on these results we studied the calcium intake during several European missions and performed an experiment during the German MIR 97 mission

  5. Dysregulation of calcium homeostasis in muscular dystrophies.

    PubMed

    Vallejo-Illarramendi, Ainara; Toral-Ojeda, Ivan; Aldanondo, Garazi; López de Munain, Adolfo

    2014-10-08

    Muscular dystrophies are a group of diseases characterised by the primary wasting of skeletal muscle, which compromises patient mobility and in the most severe cases originate a complete paralysis and premature death. Existing evidence implicates calcium dysregulation as an underlying crucial event in the pathophysiology of several muscular dystrophies, such as dystrophinopathies, calpainopathies or myotonic dystrophy among others. Duchenne muscular dystrophy is the most frequent myopathy in childhood, and calpainopathy or LGMD2A is the most common form of limb-girdle muscular dystrophy, whereas myotonic dystrophy is the most frequent inherited muscle disease worldwide. In this review, we summarise recent advances in our understanding of calcium ion cycling through the sarcolemma, the sarcoplasmic reticulum and mitochondria, and its involvement in the pathogenesis of these dystrophies. We also discuss some of the clinical implications of recent findings regarding Ca2+ handling as well as novel approaches to treat muscular dystrophies targeting Ca2+ regulatory proteins.

  6. Abnormalities of mitochondrial functioning can partly explain the metabolic disorders encountered in sarcopenic gastrocnemius.

    PubMed

    Martin, Caroline; Dubouchaud, Hervé; Mosoni, Laurent; Chardigny, Jean-Michel; Oudot, Alexandra; Fontaine, Eric; Vergely, Catherine; Keriel, Christiane; Rochette, Luc; Leverve, Xavier; Demaison, Luc

    2007-04-01

    Aging triggers several abnormalities in muscle glycolytic fibers including increased proteolysis, reactive oxygen species (ROS) production and apoptosis. Since the mitochondria are the main site of substrate oxidation, ROS production and programmed cell death, we tried to know whether the cellular disorders encountered in sarcopenia are due to abnormal mitochondrial functioning. Gastrocnemius mitochondria were extracted from adult (6 months) and aged (21 months) male Wistar rats. Respiration parameters, opening of the permeability transition pore and ROS production, with either glutamate (amino acid metabolism) or pyruvate (glucose metabolism) as a respiration substrate, were evaluated at different matrix calcium concentrations. Pyruvate dehydrogenase and respiratory complex activities as well as their contents measured by Western blotting analysis were determined. Furthermore, the fatty acid profile of mitochondrial phospholipids was also measured. At physiological calcium concentration, state III respiration rate was lowered by aging in pyruvate conditions (-22%), but not with glutamate. The reduction of pyruvate oxidation resulted from a calcium-dependent inactivation of the pyruvate dehydrogenase system and could provide for the well-known proteolysis encountered during sarcopenia. Matrix calcium loading and aging increased ROS production. They also reduced the oxidative phosphorylation. This was associated with lower calcium retention capacities, suggesting that sarcopenic fibers are more prone to programmed cell death. Aging was also associated with a reduced mitochondrial superoxide dismutase activity, which does not intervene in toxic ROS overproduction but could explain the lower calcium retention capacities. Despite a lower content, cytochrome c oxidase displayed an increased activity associated with an increased n-6/n-3 polyunsaturated fatty acid ratio of mitochondrial phospholipids. In conclusion, we propose that mitochondria obtained from aged muscle

  7. Cycle Analysis

    SciTech Connect

    Wright, Steven A.

    2012-03-20

    1. The Cycle Analysis code is an Microsoft Excel code that performs many different types of thermodynamic cycle analysis for power producing systems. The code will calculate the temperature and pressure and all other thermodynamic properties at the inlet and outlet of each component. The code also calculates the power that is produced, the efficiency, and the heat transported in the heater, gas chiller and recuperators. The code provides a schematic of the loop and provides the temperature and pressure at each location in the loop. The code also provides a T-S (temperature-entropy) diagram of the loop and often it provides an pressure enthalpy plot as well. 2. This version of the code concentrates on supercritical CO2 power cycles, but by simply changing the name of the working fluid many other types of fluids can be analyzed. The Cycle Analysis code provided here contains 18 different types of power cycles. Each cycle is contained in one worksheet or tab that the user can select. The user can change the yellow highlighted regions to perform different thermodynamic cycle analysis.

  8. Calcium channels, external calcium concentration and cell proliferation.

    PubMed

    Borowiec, Anne-Sophie; Bidaux, Gabriel; Pigat, Natascha; Goffin, Vincent; Bernichtein, Sophie; Capiod, Thierry

    2014-09-15

    Evidence for a role for calcium channel proteins in cell proliferation is numerous suggesting that calcium influx is essential in this physiological process. Several studies in the past thirty years have demonstrated that calcium channel expression levels are determinant in cell proliferation. Voltage-gated, store-operated, second messengers and receptor-operated calcium channels have been associated to cell proliferation. However, the relationship between calcium influx and cell proliferation can be uncoupled in transformed and cancer cells, resulting in an external calcium-independent proliferation. Thus, protein expression could be more important than channel function to trigger cell proliferation suggesting that additional channel functions may be responsible to reconcile calcium channel expression and cell proliferation. When needed, external calcium concentration is obviously important for calcium channel function but it also regulates calcium sensing receptor (CaSR) activity. CaSR can up- or down-regulate cell proliferation depending on physiological conditions. CaSR sensitivity to external calcium is within the 0.5 to 5 mM range and therefore, the role of these receptors in cell proliferation must be taken into account. We therefore suggest here that cell proliferation rates could depend on the relative balance between calcium influx and CaSR activation.

  9. Calcium Ligation in Photosystem II under Inhibiting Conditions

    PubMed Central

    Barry, Bridgette A.; Hicks, Charles; De Riso, Antonio; Jenson, David L.

    2005-01-01

    In oxygenic photosynthesis, PSII carries out the oxidation of water and reduction of plastoquinone. The product of water oxidation is molecular oxygen. The water splitting complex is located on the lumenal side of the PSII reaction center and contains manganese, calcium, and chloride. Four sequential photooxidation reactions are required to generate oxygen from water; the five sequentially oxidized forms of the water splitting complex are known as the Sn states, where n refers to the number of oxidizing equivalents stored. Calcium plays a role in water oxidation; removal of calcium is associated with an inhibition of the S state cycle. Although calcium can be replaced by other cations in vitro, only strontium maintains activity, and the steady-state rate of oxygen evolution is decreased in strontium-reconstituted PSII. In this article, we study the role of calcium in PSII that is limited in water content. We report that strontium substitution or 18OH2 exchange causes conformational changes in the calcium ligation shell. The conformational change is detected because of a perturbation to calcium ligation during the S1 to S2 and S2 to S3 transition under water-limited conditions. PMID:15985425

  10. T-Type Calcium Channel: A Privileged Gate for Calcium Entry and Control of Adrenal Steroidogenesis

    PubMed Central

    Rossier, Michel F.

    2016-01-01

    Intracellular calcium plays a crucial role in modulating a variety of functions such as muscle contraction, hormone secretion, gene expression, or cell growth. Calcium signaling has been however shown to be more complex than initially thought. Indeed, it is confined within cell microdomains, and different calcium channels are associated with different functions, as shown by various channelopathies. Sporadic mutations on voltage-operated L-type calcium channels in adrenal glomerulosa cells have been shown recently to be the second most prevalent genetic abnormalities present in human aldosterone-producing adenoma. The observed modification of the threshold of activation of the mutated channels not only provides an explanation for this gain of function but also reminds us on the importance of maintaining adequate electrophysiological characteristics to make channels able to exert specific cellular functions. Indeed, the contribution to steroid production of the various calcium channels expressed in adrenocortical cells is not equal, and the reason has been investigated for a long time. Given the very negative resting potential of these cells, and the small membrane depolarization induced by their physiological agonists, low threshold T-type calcium channels are particularly well suited for responding under these conditions and conveying calcium into the cell, at the right place for controlling steroidogenesis. In contrast, high threshold L-type channels are normally activated by much stronger cell depolarizations. The fact that dihydropyridine calcium antagonists, specific for L-type channels, are poorly efficient for reducing aldosterone secretion either in vivo or in vitro, strongly supports the view that these two types of channels differently affect steroid biosynthesis. Whether a similar analysis is transposable to fasciculata cells and cortisol secretion is one of the questions addressed in the present review. No similar mutations on L-type or T-type channels

  11. Abnormalities in Chromosomes 1q and 13 Independently Correlate With Factors of Poor Prognosis in Multiple Myeloma.

    PubMed

    Kim, Miyoung; Ju, Young Su; Lee, Eun Jin; Kang, Hee Jung; Kim, Han Sung; Cho, Hyoun Chan; Kim, Hyo Jung; Kim, Jung Ah; Lee, Dong Soon; Lee, Young Kyung

    2016-11-01

    We comprehensively profiled cytogenetic abnormalities in multiple myeloma (MM) and analyzed the relationship between cytogenetic abnormalities of undetermined prognostic significance and established prognostic factors. The karyotype of 333 newly diagnosed MM cases was analyzed in association with established prognostic factors. Survival analysis was also performed. MM with abnormal karyotypes (41.1%) exhibited high international scoring system (ISS) stage, frequent IgA type, elevated IgG or IgA levels, elevated calcium levels, elevated creatine (Cr) levels, elevated β2-microglobulin levels, and decreased Hb levels. Structural abnormalities in chromosomes 1q, 4, and 13 were independently associated with elevated levels of IgG or IgA, calcium, and Cr, respectively. Chromosome 13 abnormalities were associated with poor prognosis and decreased overall survival. This is the first study to demonstrate that abnormalities in chromosomes 1q, 4, and 13 are associated with established factors for poor prognosis, irrespective of the presence of other concurrent chromosomal abnormalities. Chromosome 13 abnormalities have a prognostic impact on overall survival in association with elevated Cr levels. Frequent centromeric breakpoints appear to be related to MM pathogenesis.

  12. Abnormalities in Chromosomes 1q and 13 Independently Correlate With Factors of Poor Prognosis in Multiple Myeloma

    PubMed Central

    Kim, Miyoung; Ju, Young-Su; Lee, Eun Jin; Kang, Hee Jung; Kim, Han-Sung; Cho, Hyoun Chan; Kim, Hyo Jung; Kim, Jung-Ah; Lee, Dong Soon

    2016-01-01

    Background We comprehensively profiled cytogenetic abnormalities in multiple myeloma (MM) and analyzed the relationship between cytogenetic abnormalities of undetermined prognostic significance and established prognostic factors. Methods The karyotype of 333 newly diagnosed MM cases was analyzed in association with established prognostic factors. Survival analysis was also performed. Results MM with abnormal karyotypes (41.1%) exhibited high international scoring system (ISS) stage, frequent IgA type, elevated IgG or IgA levels, elevated calcium levels, elevated creatine (Cr) levels, elevated β2-microglobulin levels, and decreased Hb levels. Structural abnormalities in chromosomes 1q, 4, and 13 were independently associated with elevated levels of IgG or IgA, calcium, and Cr, respectively. Chromosome 13 abnormalities were associated with poor prognosis and decreased overall survival. Conclusions This is the first study to demonstrate that abnormalities in chromosomes 1q, 4, and 13 are associated with established factors for poor prognosis, irrespective of the presence of other concurrent chromosomal abnormalities. Chromosome 13 abnormalities have a prognostic impact on overall survival in association with elevated Cr levels. Frequent centromeric breakpoints appear to be related to MM pathogenesis. PMID:27578511

  13. Evidence for a possible calcium flux dependent cardiomyopathy in hyperthyroidism

    SciTech Connect

    Barat, J.L.; Wicker, P.; Manley, W.; Brendel, A.J.; Lefort, G.; San Galli, F.; Commenges-Ducos, M.; Latapie, J.L.; Riviere, J.; Ducassou, D.

    1985-05-01

    This study was designed to test the hypothesis that the impaired functional cardiac reserve to exercise in hyperthyroidism is related to alterations in the regulation of calcium transport. In 2l hyperthyroid patients, the left ventricular ejection fraction (LVEF) was measured using equilibrium gated radionuclide angiocardiography at rest and during supine dynamic exercise. After a recovery period, the patients performed a second exercise study after random administration of Verapamil, a calcium entry blocker (11 pts), or propanolol, a beta adrenergic antagonist (10 pts) for comparison. The results showed i) normal resting LVEF with no significant change during exercise before any medication, ii) resting LVEF significantly decreased after Propanolol, and no significantly changed after Verapamil, iii) during exercise, significant increase of LVEF after Verapamil, and no significant change after Propanolol. These results are consistent with previous studies showing that abnormal change in LVEF during exercise in hyperthyroidism seems independent of beta adrenergic activation, and suggest a reversible functional cardiomyopathy dependent of calcium transporting systems.

  14. Menstrual Cycle

    MedlinePlus

    ... to the Professional version Home Women's Health Issues Biology of the Female Reproductive System Menstrual Cycle Follicular ... Version. DOCTORS: Click here for the Professional Version Biology of the Female Reproductive System Overview of the ...

  15. Endocrine abnormalities in anorexia nervosa.

    PubMed

    Lawson, Elizabeth A; Klibanski, Anne

    2008-07-01

    Anorexia nervosa (AN) is a psychiatric disease associated with notable medical complications and increased mortality. Endocrine abnormalities, including hypogonadotropic hypogonadism, hypercortisolemia, growth hormone resistance and sick euthyroid syndrome, mediate the clinical manifestations of this disease. Alterations in anorexigenic and orexigenic appetite-regulating pathways have also been described. Decreases in fat mass result in adipokine abnormalities. Although most of the endocrine changes that occur in AN represent physiologic adaptation to starvation, some persist after recovery and might contribute to susceptibility to AN recurrence. In this Review, we summarize key endocrine alterations in AN, with a particular focus on the profound bone loss that can occur in this disease. Although AN is increasingly prevalent among boys and men, the disorder predominantly affects girls and women who are, therefore, the focus of this Review.

  16. [Chromosome abnormalities in human cancer].

    PubMed

    Salamanca-Gómez, F

    1995-01-01

    Recent investigation on the presence of chromosome abnormalities in neoplasias has allowed outstanding advances in the knowledge of malignant transformation mechanisms and important applications in the clinical diagnosis and prognosis of leukaemias, lymphomas and solid tumors. The purpose of the present paper is to discuss the most relevant cytogenetic aberrations, some of them described at the Unidad de Investigación Médica en Genética Humana, Instituto Mexicano del Seguro Social, and to correlate these abnormalities with recent achievements in the knowledge of oncogenes, suppressor genes or antioncogenes, their chromosome localization, and their mutations in human neoplasia; as well as their perspectives in prevention and treatment of cancer that such findings permit to anticipate.

  17. Eye abnormalities in Fryns syndrome.

    PubMed

    Pierson, Diane M; Taboada, Eugenio; Butler, Merlin G

    2004-03-15

    Fryns syndrome is a rare, generally lethal, autosomal recessive multiple congenital anomaly (MCA) syndrome first described in 1979. Patients with the syndrome present with the classical findings of cloudy cornea, brain malformations, diaphragmatic defects, and distal limb deformities. Over 70 patients have been reported revealing a wide variety of phenotypic features. Although initially considered a major feature of Fryns syndrome, cloudy cornea has been relegated as a minor diagnostic sign and not commonly reported in patients since the original description. However, eye findings per se are not uncommon. Abnormal eye findings occasionally reported in Fryns syndrome potentially result in amblyopia and blindness, profoundly affecting neurologic outcome of those who survive the neonatal period. We reviewed 77 reported patients with Fryns syndrome and summarized the abnormal eye findings identified in 12 of the reported cases. In addition, we contribute three new patients with Fryns syndrome, one of which demonstrated unilateral microphthalmia and cloudy cornea.

  18. Neuroendocrine abnormalities in Parkinson's disease.

    PubMed

    De Pablo-Fernández, Eduardo; Breen, David P; Bouloux, Pierre M; Barker, Roger A; Foltynie, Thomas; Warner, Thomas T

    2017-02-01

    Neuroendocrine abnormalities are common in Parkinson's disease (PD) and include disruption of melatonin secretion, disturbances of glucose, insulin resistance and bone metabolism, and body weight changes. They have been associated with multiple non-motor symptoms in PD and have important clinical consequences, including therapeutics. Some of the underlying mechanisms have been implicated in the pathogenesis of PD and represent promising targets for the development of disease biomarkers and neuroprotective therapies. In this systems-based review, we describe clinically relevant neuroendocrine abnormalities in Parkinson's disease to highlight their role in overall phenotype. We discuss pathophysiological mechanisms, clinical implications, and pharmacological and non-pharmacological interventions based on the current evidence. We also review recent advances in the field, focusing on the potential targets for development of neuroprotective drugs in Parkinson's disease and suggest future areas for research.

  19. Cellular Mechanisms of Calcium-Mediated Triggered Activity

    NASA Astrophysics Data System (ADS)

    Song, Zhen

    Life-threatening cardiac arrhythmias continue to pose a major health problem. Ventricular fibrillation, which is a complex form of electrical wave turbulence in the lower chambers of the heart, stops the heart from pumping and is the largest cause of natural death in the United States. Atrial fibrillation, a related form of wave turbulence in the upper heart chambers, is in turn the most common arrhythmia diagnosed in clinical practice. Despite extensive research to date, mechanisms of cardiac arrhythmias remain poorly understood. It is well established that both spatial disorder of the refractory period of heart cells and triggered activity (TA) jointly contribute to the initiation and maintenance of arrhythmias. TA broadly refers to the abnormal generation of a single or a sequence of abnormal excitation waves from a small submillimeter region of the heart in the interval of time between two normal waves generated by the heart's natural pacemaker (the sinoatrial node). TA has been widely investigated experimentally and occurs in several pathological conditions where the intracellular concentration of free Ca2+ ions in heart cells becomes elevated. Under such conditions, Ca2+ can be spontaneously released from intracellular stores, thereby driving an electrogenic current that exchanges 3Na+ ions for one Ca2+ ion across the cell membrane. This current in turn depolarizes the membrane of heart cells after a normal excitation. If this calcium-mediated "delayed after depolarization'' (DAD) is sufficiently large, it can generate an action potential. While the arrhythmogenic importance of spontaneous Ca2+ release and DADs is well appreciated, the conditions under which they occur in heart pathologies remain poorly understood. Calcium overload is only one factor among several other factors that can promote DADs, including sympathetic nerve stimulation, different expression levels of membrane ion channels and calcium handling proteins, and different mutations of those

  20. Cycling injuries.

    PubMed Central

    Cohen, G. C.

    1993-01-01

    Bicycle-related injuries have increased as cycling has become more popular. Most injuries to recreational riders are associated with overuse or improper fit of the bicycle. Injuries to racers often result from high speeds, which predispose riders to muscle strains, collisions, and falls. Cyclists contact bicycles at the pedals, seat, and handlebars. Each is associated with particular cycling injuries. Images Figure 1 Figure 3 Figure 4 Figure 5 PMID:8471908

  1. High Blood Calcium (Hypercalcemia)

    MedlinePlus

    ... as sarcoidosis • Hormone disorders, such as overactive thyroid (hyperthyroidism) • A genetic condition called familial hypocalciuric hypercalcemia • Kidney ... topics: www.hormone.org (search for PHPT, calcium, hyperthyroidism, or osteoporosis) • MedlinePlus (National Institutes of Health-NIH): ...

  2. Calcium silicate insulation structure

    DOEpatents

    Kollie, Thomas G.; Lauf, Robert J.

    1995-01-01

    An insulative structure including a powder-filled evacuated casing utilizes a quantity of finely divided synthetic calcium silicate having a relatively high surface area. The resultant structure-provides superior thermal insulating characteristics over a broad temperature range and is particularly well-suited as a panel for a refrigerator or freezer or the insulative barrier for a cooler or a insulated bottle.

  3. Calcium biofortification of crops

    USDA-ARS?s Scientific Manuscript database

    More than half of the world's population is deficient in calcium (Ca), iron (Fe), iodine (I), magnesium (Mg), selenium (Se), or zinc (Zn). The consumption of plants, directly or via livestock, containing inadequate concentrations of particular minerals causes these deficiencies. Agronomic and geneti...

  4. Diet and calcium stones.

    PubMed Central

    Hughes, J; Norman, R W

    1992-01-01

    OBJECTIVE: To review the current literature on the dietary modification of urinary risk factors as a means of reducing the likelihood of recurrent stone formation and to develop practical dietary recommendations that might be useful to this end. DATA SOURCES: MEDLINE was searched for English-language articles published from 1983 to 1990. Additional references were selected from the bibliographies of identified articles. STUDY SELECTION: Nonrandomized trials and retrospective reviews were included because of a paucity of randomized controlled trials. DATA SYNTHESIS: Information on the dietary intake of calcium, oxalate, protein, sodium and fibre and on alcohol and fluid intake was used to develop practical guidelines on dietary modification. CONCLUSION: Dietary modification plays an important role in the reduction of urinary risk factors in patients with calcium stone disease of the urinary tract. As an initial form of prevention attention should be directed toward moderating the intake of calcium, oxalate, protein, sodium and alcohol and increasing the intake of fibre and water. Future research should include an assessment of the long-term reduction of dietary and urinary risk factors and the rates of recurrence of calcium stones. PMID:1310430

  5. Calcium and Vitamin D

    USDA-ARS?s Scientific Manuscript database

    Adequate intakes of vitamin D and calcium are essential preventative measures and essential components of any therapeutic regimen for osteoporosis. Vitamin D is also important for the prevention of falls. Current evidence suggests that a 25-hydroxyvitamin D level of 75 nmol/L (30 ng/ml) or higher ...

  6. Assay for calcium channels

    SciTech Connect

    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. Chromosome abnormalities in neurological diseases.

    PubMed

    Vassilopoulos, D

    1976-01-01

    The current status of research into chromosomal abnormalities in neurological diseases is reviewed. The only possible association between chromosome aberration and neurological disorder is found in ataxia telangiectasia and in tumours of the nervous system. In the remaining diseases reviewed, no specific association was confirmed. This was expected to some extent, since the majority of these diseases (spinal muscular atrophies, muscular dystrophies, etc.) are due to single gene defects.

  8. [Normal and abnormal skin color].

    PubMed

    Ortonne, J-P

    2012-11-01

    The varieties of normal skin color in humans range from people of "no color" (pale white) to "people of color" (light brown, dark brown, and black). Skin color is a blend resulting from the skin chromophores red (oxyhaemoglobin), blue (deoxygenated haemoglobin), yellow-orange (carotene, an exogenous pigment), and brown (melanin). Melanin, however, is the major component of skin color ; it is the presence or absence of melanin in the melanosomes in melanocytes and melanin in keratinocytes that is responsible for epidermal pigmentation, and the presence of melanin in macrophages or melanocytes in the dermis that is responsible for dermal pigmentation. Two groups of pigmentary disorders are commonly distinguished: the disorders of the quantitative and qualitative distribution of normal pigment and the abnormal presence of exogenous or endogenous pigments in the skin. The first group includes hyperpigmentations, which clinically manifest by darkening of the skin color, and leukodermia, which is characterized by lightening of the skin. Hypermelanosis corresponds to an overload of melanin or an abnormal distribution of melanin in the skin. Depending on the color, melanodermia (brown/black) and ceruloderma (blue/grey) are distinguished. Melanodermia correspond to epidermal hypermelanocytosis (an increased number of melanocytes) or epidermal hypermelanosis (an increase in the quantity of melanin in the epidermis with no modification of the number of melanocytes). Ceruloderma correspond to dermal hypermelanocytosis (abnormal presence in the dermis of cells synthesizing melanins) ; leakage in the dermis of epidermal melanin also exists, a form of dermal hypermelanosis called pigmentary incontinence. Finally, dyschromia can be related to the abnormal presence in the skin of a pigment of exogenous or endogenous origin. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  9. Antenatal calcium intake in Malaysia.

    PubMed

    Mahdy, Zaleha Abdullah; Basri, Hashimah; Md Isa, Zaleha; Ahmad, Shuhaila; Shamsuddin, Khadijah; Mohd Amin, Rahmah

    2014-04-01

    To determine the adequacy of antenatal calcium intake in Malaysia, and the influencing factors. A cross-sectional study was conducted among postnatal women who delivered in two tertiary hospitals. Data were collected from antenatal cards, hospital documents and diet recall on daily milk and calcium intake during pregnancy. SPSS version 19.0 was used for statistical analyses. A total of 150 women were studied. The total daily calcium intake was 834 ± 43 mg (mean ± standard error of the mean), but the calcium intake distribution curve was skewed to the right with a median intake of 725 mg daily. When calcium intake from milk and calcium supplements was excluded, the daily dietary calcium intake was only 478 ± 25 mg. Even with inclusion of milk and calcium supplements, more than a third (n=55 or 36.7%) of the women consumed less than 600 mg calcium in their daily diet. The adequacy of daily calcium intake was not influenced by maternal age, ethnicity, income or maternal job or educational status as well as parity. The daily dietary calcium intake of the Malaysian antenatal population is far from adequate without the addition of calcium supplements and milk. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

  10. The Plasma Membrane Calcium Pump

    NASA Technical Reports Server (NTRS)

    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.

  11. The Plasma Membrane Calcium Pump

    NASA Technical Reports Server (NTRS)

    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.

  12. Impregnating Coal With Calcium Carbonate

    NASA Technical Reports Server (NTRS)

    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.

  13. Abnormal uterine bleeding in perimenopause.

    PubMed

    Goldstein, S R; Lumsden, M A

    2017-10-01

    Abnormal uterine bleeding is one of the commonest presenting complaints encountered in a gynecologist's office or primary-care setting. The wider availability of diagnostic tools has allowed prompt diagnosis and treatment of an increasing number of menstrual disorders in an office setting. This White Paper reviews the advantages and disadvantages of transvaginal ultrasound, blind endometrial sampling and diagnostic hysteroscopy. Once a proper diagnosis has been established, appropriate therapy may be embarked upon. Fortunately, only a minority of such patients will have premalignant or malignant disease. When bleeding is sufficient to cause severe anemia or even hypovolemia, prompt intervention is called for. In most of the cases, however, the abnormal uterine bleeding will be disquieting to the patient and significantly affect her 'quality of life'. Sometimes, reassurance and expectant management will be sufficient in such patients. Overall, however, in cases of benign disease, some intervention will be required. The use of oral contraceptive pills especially those with a short hormone-free interval, the insertion of the levonorgestrel intrauterine system, the incorporation of newer medical therapies including antifibrinolytic drugs and selective progesterone receptor modulators and minimally invasive treatments have made outpatient therapy increasingly effective. For others, operative hysteroscopy and endometrial ablation are proven therapeutic tools to provide both long- and short-term relief of abnormal uterine bleeding, thus avoiding, or deferring, hysterectomy.

  14. Meiotic abnormalities in infertile males.

    PubMed

    Egozcue, J; Sarrate, Z; Codina-Pascual, M; Egozcue, S; Oliver-Bonet, M; Blanco, J; Navarro, J; Benet, J; Vidal, F

    2005-01-01

    Meiotic anomalies, as reviewed here, are synaptic chromosome abnormalities, limited to germ cells that cannot be detected through the study of the karyotype. Although the importance of synaptic errors has been underestimated for many years, their presence is related to many cases of human male infertility. Synaptic anomalies can be studied by immunostaining of synaptonemal complexes (SCs), but in this case their frequency is probably underestimated due to the phenomenon of synaptic adjustment. They can also be studied in classic meiotic preparations, which, from a clinical point of view, is still the best approach, especially if multiplex fluorescence in situ hybridization is at hand to solve difficult cases. Sperm chromosome FISH studies also provide indirect evidence of their presence. Synaptic anomalies can affect the rate of recombination of all bivalents, produce achiasmate small univalents, partially achiasmate medium-sized or large bivalents, or affect all bivalents in the cell. The frequency is variable, interindividually and intraindividually. The baseline incidence of synaptic anomalies is 6-8%, which may be increased to 17.6% in males with a severe oligozoospermia, and to 27% in normozoospermic males with one or more previous IVF failures. The clinical consequences are the production of abnormal spermatozoa that will produce a higher number of chromosomally abnormal embryos. The indications for a meiotic study in testicular biopsy are provided.

  15. Abnormal sexual behavior during sleep.

    PubMed

    Della Marca, Giacomo; Dittoni, Serena; Frusciante, Roberto; Colicchio, Salvatore; Losurdo, Anna; Testani, Elisa; Buccarella, Cristina; Modoni, Anna; Mazza, Salvatore; Mennuni, Gioacchino Francesco; Mariotti, Paolo; Vollono, Catello

    2009-12-01

    Automatic, uncontrolled, and unaware sexual behaviors during sleep have occasionally been described. The clinical and polysomnographic features of nocturnal sexual behavior allow it to be considered a distinct parasomnia named "sexsomnia". Recently, abnormal sexual behaviors during sleep have been evaluated in the forensic medical context because violent behaviors can be associated with this parasomnia. To describe the clinical and polysomnographic findings in three patients who referred to our sleep laboratory for sleep disorders and who reported episodes of sleep-related sexual activation. We analyzed video-polysomnographic recordings, sleep structure, sleep microstructure, and sleep-related respiratory events. The patients were three males aged 42, 32, and 46 years. All had unremarkable medical, neurological, and psychiatric histories. All underwent full-night polysomnography. Each patient presented a distinct sleep disorder: one had severe obstructive sleep apnea syndrome (OSAS), one presented clinical and polysomnographic features of non-rapid eye movement (NREM) sleep parasomnia (somnambulism), and the third presented clinical and polysomnographic features of rapid eye movement behavior disorder. In our patients, the clinical and polysomnographic findings suggest that abnormal nocturnal sexual behavior can occur in association with distinct sleep disorders, characterized by different pathophysiologic mechanisms and distinctive treatments. Abnormal sexual behaviors during sleep should be investigated with polysomnography in order to define their pathophysiology and to establish appropriate treatments.

  16. Congenital abnormalities of the goat.

    PubMed

    Basrur, P K

    1993-03-01

    Congenital abnormalities of genetic and environmental causes constitute a striking proportion of the afflictions seen in goats. These include a variety of malformations and metabolic diseases that could occur in all breeds but tend to exhibit predisposition in some breeds of goats. Genetic abnormalities for which the carrier state is detectable with the aid of enzymes and surface protein markers can be eliminated from goat populations, whereas common polygenic disorders including udder problems in does and gynecomastia in bucks are more difficult to eradicate because the mutant genes responsible for these traits generally do not declare themselves until inbreeding brings together a critical concentration of liability genes to create a crisis. A substantial reduction of common abnormalities in this species, such as intersexuality in dairy breeds, abortion in Angora breed, and arthritis in the Pygmy breed, will require a change in breeders' preference and selection practice. In making these changes, however, the beneficial traits will have to be balanced against the undesirable effects of the selected mutant genes (pleiotropy), which hold the key to success or failure of a breed under domestication.

  17. Prothrombin Segovia: a new congenital abnormality of prothrombin.

    PubMed

    Rocha, E; Paramo, J A; Bascones, C; Fisac, P R; Cuesta, B; Fernandez, J

    1986-05-01

    A family with a new congenital dysprothrombinemia is presented. The propositus is a 21-yr-old man who presented simultaneously with hemartrosis of the left knee and an extensive hematoma following a minor trauma. Prothrombin time and activated partial thromboplastin time were prolonged. Prothrombin activity was very low when measured by biological assay using physiological activators (7% by one-stage method and 20% by two-stage method) or a Russel's viper venom-cephalin mixture (23%), Notechis scutatus scutatus venom (15%) and Echis carinatus venom (17%); in contrast, the level was found to be borderline to normal using Taipan viper venom (64%) and normal by both staphylocoagulase and immunologic methods. Family studies revealed consanguinity between the propositus' mother and father and both presented a 50% reduced prothrombin level when physiological activators or Echis carinatus viper venom were used. A line of identity between normal and abnormal prothrombin was observed on immunodiffusion. The migration of the abnormal prothrombin was less anodic and was not changed by the addition of calcium. The patient's serum showed 3 bands in the bidimensional immunoelectrophoresis system, whereas normal serum showed only 2 bands. The term prothrombin Segovia is proposed to define this new prothrombin abnormality.

  18. Bioceramics of calcium orthophosphates.

    PubMed

    Dorozhkin, Sergey V

    2010-03-01

    A strong interest in use of ceramics for biomedical applications appeared in the late 1960's. Used initially as alternatives to metals in order to increase a biocompatibility of implants, bioceramics have become a diverse class of biomaterials, presently including three basic types: relatively bioinert ceramics, bioactive (or surface reactive) and bioresorbable ones. Furthermore, any type of bioceramics could be porous to provide tissue ingrowth. This review is devoted to bioceramics prepared from calcium orthophosphates, which belong to the categories of bioresorbable and bioactive compounds. During the past 30-40 years, there have been a number of major advances in this field. Namely, after the initial work on development of bioceramics that was tolerated in the physiological environment, emphasis was shifted towards the use of bioceramics that interacted with bones by forming a direct chemical bond. By the structural and compositional control, it became possible to choose whether the bioceramics of calcium orthophosphates was biologically stable once incorporated within the skeletal structure or whether it was resorbed over time. At the turn of the millennium, a new concept of calcium orthophosphate bioceramics, which is able to regenerate bone tissues, has been developed. Current biomedical applications of calcium orthophosphate bioceramics include replacements for hips, knees, teeth, tendons and ligaments, as well as repair for periodontal disease, maxillofacial reconstruction, augmentation and stabilization of the jawbone, spinal fusion and bone fillers after tumor surgery. Potential future applications of calcium orthophosphate bioceramics will include drug-delivery systems, as well as they will become effective carriers of growth factors, bioactive peptides and/or various types of cells for tissue engineering purposes.

  19. Visual pathway abnormalities in tuberculous meningitis.

    PubMed

    Maurya, Pradeep Kumar; Singh, Ajai Kumar; Sharma, Lalit; Kulshreshtha, Dinkar; Thacker, Anup Kumar

    2016-11-01

    Ophthalmological complications are common and disabling in patients with tuberculous meningitis. We aimed to study the visual pathway abnormalities in patients with tuberculous meningitis. Forty-three patients with tuberculous meningitis were subjected to visual evoked responses (VER) and neuroophthalmologic assessment. Neuroophthalmologic assessment revealed abnormalities in 22 (51.3%) patients. VER were found to be abnormal in 27 (62.8%) patients. The VER abnormalities included prolonged P100 latencies with relatively normal amplitude and significant interocular latency differences. Visual pathways abnormalities are common in patients with tuberculous meningitis and are often subclinical. Pathophysiologic explanations for electrophysiological abnormalities on VER in these patients are incompletely understood and needs further exploration.

  20. Calmidazolium evokes high calcium fluctuations in Plasmodium falciparum.

    PubMed

    Budu, Alexandre; Gomes, Mayrim M; Melo, Pollyana M; El Chamy Maluf, Sarah; Bagnaresi, Piero; Azevedo, Mauro F; Carmona, Adriana K; Gazarini, Marcos L

    2016-03-01

    Calcium and calmodulin (CaM) are important players in eukaryote cell signaling. In the present study, by using a knockin approach, we demonstrated the expression and localization of CaM in all erythrocytic stages of Plasmodium falciparum. Under extracellular Ca(2+)-free conditions, calmidazolium (CZ), a potent CaM inhibitor, promoted a transient cytosolic calcium ([Ca(2+)]cyt) increase in isolated trophozoites, indicating that CZ mobilizes intracellular sources of calcium. In the same extracellular Ca(2+)-free conditions, the [Ca(2+)]cyt rise elicited by CZ treatment was ~3.5 fold higher when the endoplasmic reticulum (ER) calcium store was previously depleted ruling out the mobilization of calcium from the ER by CZ. The effects of the Ca(2+)/H(+) ionophore ionomycin (ION) and the Na(+)/H(+) ionophore monensin (MON) suggest that the [Ca(2+)]cyt-increasing effect of CZ is driven by the removal of Ca(2+) from at least one Ca(2+)-CaM-related (CaMR) protein as well as by the mobilization of Ca(2+) from intracellular acidic calcium stores. Moreover, we showed that the mitochondrion participates in the sequestration of the cytosolic Ca(2+) elicited by CZ. Finally, the modulation of membrane Ca(2+) channels by CZ and thapsigargin (THG) was demonstrated. The opened channels were blocked by the unspecific calcium channel blocker Co(2+) but not by 2-APB (capacitative calcium entry inhibitor) or nifedipine (L-type Ca(2+) channel inhibitor). Taken together, the results suggested that one CaMR protein is an important modulator of calcium signaling and homeostasis during the Plasmodium intraerythrocytic cell cycle, working as a relevant intracellular Ca(2+) reservoir in the parasite. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Fertilization and embryo quality of mature oocytes with specific morphological abnormalities.

    PubMed

    Yu, Eun Jeong; Ahn, Hyojeong; Lee, Jang Mi; Jee, Byung Chul; Kim, Seok Hyun

    2015-12-01

    To investigate fertilization and embryo quality of dysmorphic mature oocytes with specific morphological abnormalities obtained from intracytoplasmic sperm injection (ICSI). The fertilization rate (FR) and embryo quality were compared among 58 dysmorphic and 42 normal form oocytes (control 1) obtained from 35 consecutive ICSI cycles, each of which yielded at least one dysmorphic mature oocyte, performed over a period of 5 years. The FR and embryo quality of 441 normal form oocytes from another 119 ICSI cycles that did not involve dysmorphic oocytes served as control 2. Dysmorphic oocytes were classified as having a dark cytoplasm, cytoplasmic granularity, cytoplasmic vacuoles, refractile bodies in the cytoplasm, smooth endoplasmic reticulum in the cytoplasm, an oval shape, an abnormal zona pellucida, a large perivitelline space, debris in the perivitelline space, or an abnormal polar body (PB). The overall FR was significantly lower in dysmorphic oocytes than in normal form oocytes in both the control 1 and control 2 groups. However, embryo quality in the dysmorphic oocyte group and the normal form oocyte groups at day 3 was similar. The FR and embryo quality were similar in the oocyte groups with a single abnormality and multiple abnormalities. Specific abnormalities related with a higher percentage of top-quality embryos were dark cytoplasm (66.7%), abnormal PB (50%), and cytoplasmic vacuoles (25%). The fertilization potential of dysmorphic oocytes in our study was lower, but their subsequent embryonic development and embryo quality was relatively good. We were able to define several specific abnormalities related with good or poor embryo quality.

  2. Voltage-Gated Calcium Channels

    NASA Astrophysics Data System (ADS)

    Zamponi, Gerald Werner

    Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

  3. Calcium Phosphates and Human Beings

    NASA Astrophysics Data System (ADS)

    Dorozhkin, Sergey V.

    2006-05-01

    This article describes the general importance of calcium phosphates for human beings. The basic information on the structure and chemical properties of the biologically relevant calcium phosphates is summarized. Basic facts on the natural occurrence and the industrial use of natural calcium phosphates are discussed. Fundamental details on the presence of calcium phosphates in major calcified tissues (bones and teeth) of humans and mammals, as well as on biomaterials made of calcium phosphates are discussed. The article will be of value for chemistry teachers for expansion of their general background and point the students' attention to the rapidly growing topic of bone-substituting biomaterials.

  4. Vapor Compression Cycle Design Program (CYCLE_D)

    National Institute of Standards and Technology Data Gateway

    SRD 49 NIST Vapor Compression Cycle Design Program (CYCLE_D) (PC database for purchase)   The CYCLE_D database package simulates the vapor compression refrigeration cycles. It is fully compatible with REFPROP 9.0 and covers the 62 single-compound refrigerants . Fluids can be used in mixtures comprising up to five components.

  5. Hypotonic medium increases calcium permeant channels activity in human normal and dystrophic myotubes.

    PubMed

    Vandebrouck, Clarisse; Duport, Gérard; Raymond, Guy; Cognard, Christian

    2002-05-03

    Duchenne muscular dystrophy (DMD) is characterized by the absence of dystrophin and an elevated intracellular calcium level. Single-channel recordings were performed with the cell-attached configuration of the patch-clamp technique. The present study shows, on human co-cultured normal and dystrophic muscle cells, the evidence for an increased activity of calcium permeant cationic mechano-sensitive channels under hypotonic medium stimulation. This activity was particularly enhanced in DMD cells. The hypotonic medium induced drastic changes in the single-channel activity characteristics, which are: a large increase of the calcium over potassium permeability ratio; and a great enhancement of the quantity of current crossing through these channels. These channels could contribute to a significant calcium entry, which could participate in the abnormal calcium homeostasis observed in DMD muscle.

  6. Calcium signaling in taste cells.

    PubMed

    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.

  7. Bile salts and calcium absorption

    PubMed Central

    Webling, D. D'A.; Holdsworth, E. S.

    1966-01-01

    1. The study of the effect of bile salts on enhancing calcium absorption in the rachitic chick has been extended to bile salts not present in chick bile, e.g. glycine conjugates and bile alcohol sulphates. 2. Bile and bile salts cause an increase in calcium absorption from sparingly soluble calcium hydrogen phosphate when compared with a suspension of calcium hydrogen phosphate in saline. 3. If the bile ducts of normal rats are tied the absorption of calcium from calcium hydrogen phosphate decreases but can be restored by giving bile salts with the calcium salt. 4. Bile salts increase solubility in water of the sparingly soluble calcium salts, phytate and phosphate at pH values between 6 and 8. 5. Bile salts increase the solubility in lipid solvents of calcium in approximately the same proportion as they increase the absorption of calcium from the gut. 6. The physiological role of bile in calcium absorption and its mode of action are discussed. PMID:4291037

  8. Growth Control in Colon Epithelial Cells: Gadolinium Enhances Calcium-Mediated Growth Regulation

    PubMed Central

    Attili, Durga; Jenkins, Brian; Aslam, Muhammad Nadeem; Dame, Michael K.

    2013-01-01

    Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1–5 µM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet. PMID:23008064

  9. Growth control in colon epithelial cells: gadolinium enhances calcium-mediated growth regulation.

    PubMed

    Attili, Durga; Jenkins, Brian; Aslam, Muhammad Nadeem; Dame, Michael K; Varani, James

    2012-12-01

    Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1-5 μM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet.

  10. Fruit Calcium: Transport and Physiology

    PubMed Central

    Hocking, Bradleigh; Tyerman, Stephen D.; Burton, Rachel A.; Gilliham, Matthew

    2016-01-01

    Calcium has well-documented roles in plant signaling, water relations and cell wall interactions. Significant research into how calcium impacts these individual processes in various tissues has been carried out; however, the influence of calcium on fruit ripening has not been thoroughly explored. Here, we review the current state of knowledge on how calcium may impact the development, physical traits and disease susceptibility of fruit through facilitating developmental and stress response signaling, stabilizing membranes, influencing water relations and modifying cell wall properties through cross-linking of de-esterified pectins. We explore the involvement of calcium in hormone signaling integral to the physiological mechanisms behind common disorders that have been associated with fruit calcium deficiency (e.g., blossom end rot in tomatoes or bitter pit in apples). This review works toward an improved understanding of how the many roles of calcium interact to influence fruit ripening, and proposes future research directions to fill knowledge gaps. Specifically, we focus mostly on grapes and present a model that integrates existing knowledge around these various functions of calcium in fruit, which provides a basis for understanding the physiological impacts of sub-optimal calcium nutrition in grapes. Calcium accumulation and distribution in fruit is shown to be highly dependent on water delivery and cell wall interactions in the apoplasm. Localized calcium deficiencies observed in particular species or varieties can result from differences in xylem morphology, fruit water relations and pectin composition, and can cause leaky membranes, irregular cell wall softening, impaired hormonal signaling and aberrant fruit development. We propose that the role of apoplasmic calcium-pectin crosslinking, particularly in the xylem, is an understudied area that may have a key influence on fruit water relations. Furthermore, we believe that improved knowledge of the calcium

  11. [Endocrine abnormalities in anorexia nervosa].

    PubMed

    Lanfranco, F; Gianotti, L; Destefanis, S; Arvat, E; Ghigo, E; Camanni, F

    2003-06-01

    Anorexia nervosa is a syndrome with multifactorial etiology in which several genetic, biologic, psychological and social factors are involved. Patients affected by anorexia nervosa (AN) may develop multiple endocrine abnormalities, e.g. amenorrhea, hypothalamus-pituitary-adrenal axis hyperactivity, low T3 syndrome and peculiar changes of somatotroph axis function. These endocrine abnormalities are also found after prolonged starvation and may represent an adaptive response developed in order to save energy and proteins. It is still a matter of debate whether these endocrine changes are etiologic or secondary. In fact, several evidences suggest the existence in AN of hypothalamus functional alterations, which may be involved in the development and maintenance of the food intake disorder; on the other hand, the increased CRH secretion seems to be secondary to malnutrition as well as GH hypersecretion coupled to low IGF-I levels; the latter is a common finding in AN, as well as in other undernutrition and malabsorption conditions, type 1 diabetes mellitus, liver cirrhosis and catabolic states. Hypothalamic amenorrhea, which is one of the diagnostic criteria for AN, is not linked only to the reduction of body weight but reflects also deep alterations of gonadotropin secretory pattern. Low T3 syndrome is frequently found in AN; on the other hand, an iodide-induced hypothyroidism is quite uncommon. T3 reduction in AN seems to be an adaptive response to prolonged starvation; however the presence of a simultaneous central dysregulation cannot be excluded. Finally, AN patients frequently show defects in urinary concentration or dilution with inappropriate secretion of antidiuretic hormone, which may be due to intrinsic defects in the neurohypophysis or to abnormalities of its regulatory afferent neurons.

  12. Foot abnormalities of wild birds

    USGS Publications Warehouse

    Herman, C.M.; Locke, L.N.; Clark, G.M.

    1962-01-01

    The various foot abnormalities that occur in birds, including pox, scaly-leg, bumble-foot, ergotism and freezing are reviewed. In addition, our findings at the Patuxent Wildlife Research Center include pox from dove, mockingbird, cowbird, grackle and several species of sparrows. Scaly-leg has been particularly prevalent on icterids. Bumble foot has been observed in a whistling swan and in a group of captive woodcock. Ergotism is reported from a series of captive Canada geese from North Dakota. Several drug treatments recommended by others are presented.

  13. Abnormalities of the erythrocyte membrane.

    PubMed

    Gallagher, Patrick G

    2013-12-01

    Primary abnormalities of the erythrocyte membrane are characterized by clinical, laboratory, and genetic heterogeneity. Among this group, hereditary spherocytosis patients are more likely to experience symptomatic anemia. Treatment of hereditary spherocytosis with splenectomy is curative in most patients. Growing recognition of the long-term risks of splenectomy has led to re-evaluation of the role of splenectomy. Management guidelines acknowledge these considerations and recommend discussion between health care providers, patient, and family. The hereditary elliptocytosis syndromes are the most common primary disorders of erythrocyte membrane proteins. However, most elliptocytosis patients are asymptomatic and do not require therapy.

  14. Complexometric Determination of Calcium

    NASA Astrophysics Data System (ADS)

    Nielsen, S. Suzanne

    Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are detected using indicators that change color when they complex with mineral ions. Calmagite and eriochrome black T (EBT) are such indicators that change from blue to pink when they complex with calcium and magnesium. In the titration of a mineral-containing solution with EDTA, the solution turns from pink to blue at the endpoint with either indicator. The pH affects a complexometric EDTA titration in several ways, and must be carefully controlled. A major application of EDTA titration is testing the hardness of water, for which the method described is an official one (Standard Methods for the Examination of Water and Wastewater, Method 2340C; AOAC Method 920.196).

  15. Nutrition in calcium nephrolithiasis

    PubMed Central

    2013-01-01

    Idiopathic calcium nephrolithiasis is a multifactorial disease with a complex pathogenesis due to genetic and environmental factors. The importance of social and health effects of nephrolithiasis is further highlighted by the strong tendency to relapse of the disease. Long-term prospective studies show a peak of disease recurrence within 2–3 years since onset, 40-50% of patients have a recurrence after 5 years and more than 50-60% after 10 years. International nutritional studies demonstrated that nutritional habits are relevant in therapy and prevention approaches of nephrolithiasis. Water, right intake of calcium, low intake of sodium, high levels of urinary citrate are certainly important for the primary and secondary prevention of nephrolithiasis. In this review is discussed how the correction of nutritional mistakes can reduce the incidence of recurrent nephrolithiasis. PMID:23634702

  16. DISTILLATION OF CALCIUM

    DOEpatents

    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. Synthesis of calcium superoxide

    NASA Technical Reports Server (NTRS)

    Rewick, R. T.; Blucher, W. G.; Estacio, P. L.

    1972-01-01

    Efforts to prepare Ca(O2) sub 2 from reactions of calcium compounds with 100% O3 and with O(D-1) atoms generated by photolysis of O3 at 2537 A are described. Samples of Ca(OH) sub 2, CaO, CaO2, Ca metal, and mixtures containing suspected impurities to promote reaction have been treated with excess O3 under static and flow conditions in the presence and absence of UV irradiation. Studies with KO2 suggest that the superoxide anion is stable to radiation at 2537 A but reacts with oxygen atoms generated by the photolysis of O3 to form KO3. Calcium superoxide is expected to behave in an analogous.

  18. Architecture of the mitochondrial calcium uniporter.

    PubMed

    Oxenoid, Kirill; Dong, Ying; Cao, Chan; Cui, Tanxing; Sancak, Yasemin; Markhard, Andrew L; Grabarek, Zenon; Kong, Liangliang; Liu, Zhijun; Ouyang, Bo; Cong, Yao; Mootha, Vamsi K; Chou, James J

    2016-05-12

    Mitochondria from many eukaryotic clades take up large amounts of calcium (Ca(2+)) via an inner membrane transporter called the uniporter. Transport by the uniporter is membrane potential dependent and sensitive to ruthenium red or its derivative Ru360 (ref. 1). Electrophysiological studies have shown that the uniporter is an ion channel with remarkably high conductance and selectivity. Ca(2+) entry into mitochondria is also known to activate the tricarboxylic acid cycle and seems to be crucial for matching the production of ATP in mitochondria with its cytosolic demand. Mitochondrial calcium uniporter (MCU) is the pore-forming and Ca(2+)-conducting subunit of the uniporter holocomplex, but its primary sequence does not resemble any calcium channel studied to date. Here we report the structure of the pore domain of MCU from Caenorhabditis elegans, determined using nuclear magnetic resonance (NMR) and electron microscopy (EM). MCU is a homo-oligomer in which the second transmembrane helix forms a hydrophilic pore across the membrane. The channel assembly represents a new solution of ion channel architecture, and is stabilized by a coiled-coil motif protruding into the mitochondrial matrix. The critical DXXE motif forms the pore entrance, which features two carboxylate rings; based on the ring dimensions and functional mutagenesis, these rings appear to form the selectivity filter. To our knowledge, this is one of the largest membrane protein structures characterized by NMR, and provides a structural blueprint for understanding the function of this channel.

  19. Mitochondrial calcium uptake capacity modulates neocortical excitability

    PubMed Central

    Sanganahalli, Basavaraju G; Herman, Peter; Hyder, Fahmeed; Kannurpatti, Sridhar S

    2013-01-01

    Local calcium (Ca2+) changes regulate central nervous system metabolism and communication integrated by subcellular processes including mitochondrial Ca2+ uptake. Mitochondria take up Ca2+ through the calcium uniporter (mCU) aided by cytoplasmic microdomains of high Ca2+. Known only in vitro, the in vivo impact of mCU activity may reveal Ca2+-mediated roles of mitochondria in brain signaling and metabolism. From in vitro studies of mitochondrial Ca2+ sequestration and cycling in various cell types of the central nervous system, we evaluated ranges of spontaneous and activity-induced Ca2+ distributions in multiple subcellular compartments in vivo. We hypothesized that inhibiting (or enhancing) mCU activity would attenuate (or augment) cortical neuronal activity as well as activity-induced hemodynamic responses in an overall cytoplasmic and mitochondrial Ca2+-dependent manner. Spontaneous and sensory-evoked cortical activities were measured by extracellular electrophysiology complemented with dynamic mapping of blood oxygen level dependence and cerebral blood flow. Calcium uniporter activity was inhibited and enhanced pharmacologically, and its impact on the multimodal measures were analyzed in an integrated manner. Ru360, an mCU inhibitor, reduced all stimulus-evoked responses, whereas Kaempferol, an mCU enhancer, augmented all evoked responses. Collectively, the results confirm aforementioned hypotheses and support the Ca2+ uptake-mediated integrative role of in vivo mitochondria on neocortical activity. PMID:23591650

  20. Calcium antagonists and vasospasm.

    PubMed

    Meyer, F B

    1990-04-01

    A critical review of the clinical data supports the conclusion that nimodipine decreases the severity of neurologic deficits and improves outcome after subarachnoid hemorrhage. The mechanisms by which mortality and morbidity are reduced are still controversial. First, the frequency of vasospasm is not altered (Figs. 5 and 6). Second, the consistent reversal of vasospasm once present has not been demonstrated either angiographically or by noninvasive cerebral blood flow studies. These observations suggest that there is either modification of microcirculatory flow (i.e., dilation of pial conducting vessels or decreased platelet aggregation) or a direct neuronal protective effect. As suggested previously, support for either mechanism is not resolute, and further investigation is necessary. Currently, nimodipine has been the most thoroughly investigated calcium antagonist both from an experimental and clinical perspective. Oral administration has had few reported complications. Therefore, the benefit/risk ratio clearly supports the prophylactic use of this calcium antagonist in patients of all clinical grades after subarachnoid hemorrhage. Evidence also indicates that starting nimodipine after the onset of delayed ischemic deficits is of benefit. Finally, it can be predicted that in the future additional calcium antagonists with more selective vascular or neuronal effects will be developed for use in neurologic disorders.

  1. Availability of calcium from skim milk, calcium sulfate and calcium carbonate for bone mineralization in pigs.

    PubMed

    Pointillart, A; Coxam, V; Sève, B; Colin, C; Lacroix, C H; Guéguen, L

    2000-01-01

    Dairy products provide abundant, accessible calcium for humans, while some calcium sulfate-rich mineral waters could provide appreciable amounts of calcium. But there is little evidence that this calcium is as available as milk calcium for making bone. The availability of calcium was studied by monitoring bone parameters in 2-month-old pigs fed restricted amounts of calcium (70% RDA) for 2.5 months. The 3 main (> or = 50% Ca intake) Ca sources were either CaCO3 or CaSO4 or skim milk powder (29% of the diet). The bones of the pigs fed the "milk" diet had higher (P < 0.01) ash contents, breaking strength and density (DEXA) than those of the two others groups, in which the bone values were similar. Thus, the calcium provided by a diet containing milk appears to ensure better bone mineralization than do calcium salts included in a non-milk diet. The calcium restriction may have enhanced some milk properties to stimulate calcium absorption in these young, rapidly growing pigs.

  2. Measurement of cytosolic calcium: fluorescent calcium indicators.

    PubMed

    Rink, T J

    1988-01-01

    The invention of intracellularly trappable fluorescent indicators of [Ca2+i] has provided an important new way to answer many key questions about the role of Ca2+ and of other messengers in cell activation. Perhaps equally important, the results of these investigations have thrown up many interesting new questions. The suitability of this, or any other method of measuring [Ca2+]i, naturally depends on the tissue, the experimenter, the facilities available and the particular question to be asked. For simply measuring [Ca2+]i, fura-2 and indo-1 are likely to be preferable to quin2, although right now more is known about quin2, its behaviour and its calibration in cells. Anecdotal evidence suggests that indo-1 may have advantages over fura-2 although many more people are presently using fura-2. For manipulating [Ca2+]i by deliberately adding Ca2+ buffering power, quin2 may have advantages and is certainly the tried and tested method. For epithelial cell work, where the relation of the cells to the rest of the tissue and their polarity are critical, suspensions and even monolayer measurements will seldom be adequate. Calcium microelectrodes or single-cell fluorescence techniques will surely be required and rewarding.

  3. Design Principles of Reptilian Muscles: Calcium Cycling Strategies.

    PubMed

    Perni, Stefano; Close, Matthew; Franzini-Armstrong, Clara

    2016-03-01

    The ultrastructure of the sarcoplasmic reticulum (SR) in skeletal muscles was compared among different reptile species (watersnake, boa constrictor, lizard, and turtle) and a mammal (mouse). Morphometric analysis demonstrates a pattern of increasing calsequestrin (CASQ) content in the lumen of SR from turtle to lizard, watersnake, and boa constrictor, and this content is in all cases higher than in mouse. In all reptiles sampled except turtle, CASQ is not confined to the junctional sarcoplasmic reticulum (jSR) cisternae as it is in other species. It instead fills the entire longitudinal (free) SR (fSR) regions, and in the extreme case of snakes, the shape of the SR is modified around the extra CASQ. We suggest that high CASQ content may represent an ATP-saving adaptation that permits relatively low metabolic rates during prolonged periods of fasting and inactivity, particularly in watersnake and boa constrictor. © 2015 Wiley Periodicals, Inc.

  4. Menu Cycles.

    ERIC Educational Resources Information Center

    Clayton, Alfred; Almony, John

    The curriculum guide for commercial foods instruction is designed to aid the teacher in communicating the importance of menu cycles in commercial food production. It also provides information about the necessary steps in getting food from the raw form to the finished product, and then to the consumer. In addition to providing information on how to…

  5. Biochemical Abnormalities in Psychiatric Outpatients

    PubMed Central

    Lipman, Daniel G.; Collins, James L.; Mathura, Clyde B.; Elder, Zelda B.

    1984-01-01

    This research project was an outgrowth of the observations of the senior author over a period exceeding four decades of practice, teaching, and research as internist and psychiatrist, with primary emphasis on relationships between psyche and soma. Patients at the Outpatient Psychiatric Clinic of the Howard University Hospital, Washington, DC, were given thorough annual physical examinations and laboratory evaluations of blood and urine. The authors found a significantly high incidence of medical illnesses and abnormal laboratory findings not previously suspected. There was a significant and direct correlation between psychopathology as projected in the Lipman Personality Image Projection (LPIP) test and abnormal laboratory and physical findings. The results in this study concur with previous reports that so-called purely psychogenic stress symptoms may be related to unrecognized medical illnesses. These somatic illnesses may remain unrecognized for indefinite periods of time in the traditional psychiatric outpatient setting from which patients are often referred elsewhere for treatment of nonpsychiatric illness. Initial and periodic physical and laboratory examinations should be performed by psychiatrists trained to recognize nonpsychiatric diseases that often present with psychiatric symptoms. A thorough knowledge of the mind-body relationship is essential to the practice of modern psychiatry. PMID:6716498

  6. Lower extremity abnormalities in children.

    PubMed

    Sass, Pamela; Hassan, Ghinwa

    2003-08-01

    Rotational and angular problems are two types of lower extremity abnormalities common in children. Rotational problems include intoeing and out-toeing. Intoeing is caused by one of three types of deformity: metatarsus adductus, internal tibial torsion, and increased femoral anteversion. Out-toeing is less common than intoeing, and its causes are similar but opposite to those of intoeing. These include femoral retroversion and external tibial torsion. Angular problems include bowlegs and knock-knees. An accurate diagnosis can be made with careful history and physical examination, which includes torsional profile (a four-component composite of measurements of the lower extremities). Charts of normal values and values with two standard deviations for each component of the torsional profile are available. In most cases, the abnormality improves with time. A careful physical examination, explanation of the natural history, and serial measurements are usually reassuring to the parents. Treatment is usually conservative. Special shoes, cast, or braces are rarely beneficial and have no proven efficacy. Surgery is reserved for older children with deformity from three to four standard deviations from the normal.

  7. Normal and abnormal lid function.

    PubMed

    Rucker, Janet C

    2011-01-01

    This chapter on lid function is comprised of two primary sections, the first on normal eyelid anatomy, neurological innervation, and physiology, and the second on abnormal eyelid function in disease states. The eyelids serve several important ocular functions, the primary objectives of which are protection of the anterior globe from injury and maintenance of the ocular tear film. Typical eyelid behaviors to perform these functions include blinking (voluntary, spontaneous, or reflexive), voluntary eye closure (gentle or forced), partial lid lowering during squinting, normal lid retraction during emotional states such as surprise or fear (startle reflex), and coordination of lid movements with vertical eye movements for maximal eye protection. Detailed description of the neurological innervation patterns and neurophysiology of each of these lid behaviors is provided. Abnormal lid function is divided by conditions resulting in excessive lid closure (cerebral ptosis, apraxia of lid opening, blepharospasm, oculomotor palsy, Horner's syndrome, myasthenia gravis, and mechanical) and those resulting in excessive lid opening (midbrain lid retraction, facial nerve palsy, and lid retraction due to orbital disease).

  8. Human papillomavirus type 59 immortalized keratinocytes express late viral proteins and infectious virus after calcium stimulation.

    PubMed

    Lehr, Elizabeth E; Qadadri, Brahim; Brown, Calla R; Brown, Darron R

    2003-09-30

    Human papillomavirus type 59 (HPV 59) is an oncogenic type related to HPV 18. HPV 59 was recently propagated in the athymic mouse xenograft system. A continuous keratinocyte cell line infected with HPV 59 was created from a foreskin xenograft grown in an athymic mouse. Cells were cultured beyond passage 50. The cells were highly pleomorphic, containing numerous abnormally shaped nuclei and mitotic figures. HPV 59 sequences were detected in the cells by DNA in situ hybridization in a diffuse nuclear distribution. Southern blots were consistent with an episomal state of HPV 59 DNA at approximately 50 copies per cell. Analysis of the cells using a PCR/reverse blot strip assay, which amplifies a portion of the L1 open reading frame, was strongly positive. Differentiation of cells in monolayers was induced by growth in F medium containing 2 mM calcium chloride for 10 days. Cells were harvested as a single tissue-like sheet, and histologic analysis revealed a four-to-six cell-thick layer. Transcripts encoding involucrin, a cornified envelope protein, and the E1/E4 and E1/E4/L1 viral transcripts were detected after several days of growth in F medium containing 2 mM calcium chloride. The E1/E4 and L1 proteins were detected by immunohistochemical analysis, and virus particles were seen in electron micrographs in a subset of differentiated cells. An extract of differentiated cells was prepared by vigorous sonication and was used to infect foreskin fragments. These fragments were implanted into athymic mice. HPV 59 was detected in the foreskin xenografts removed 4 months later by DNA in situ hybridization and PCR/reverse blot assay. Thus, the complete viral growth cycle, including production on infectious virus, was demonstrated in the HPV 59 immortalized cells grown in a simple culture system.

  9. Simultaneous electrophysiological recording and calcium imaging of suprachiasmatic nucleus neurons.

    PubMed

    Irwin, Robert P; Allen, Charles N

    2013-12-08

    Simultaneous electrophysiological and fluorescent imaging recording methods were used to study the role of changes of membrane potential or current in regulating the intracellular calcium concentration. Changing environmental conditions, such as the light-dark cycle, can modify neuronal and neural network activity and the expression of a family of circadian clock genes within the suprachiasmatic nucleus (SCN), the location of the master circadian clock in the mammalian brain. Excitatory synaptic transmission leads to an increase in the postsynaptic Ca(2+) concentration that is believed to activate the signaling pathways that shifts the rhythmic expression of circadian clock genes. Hypothalamic slices containing the SCN were patch clamped using microelectrodes filled with an internal solution containing the calcium indicator bis-fura-2. After a seal was formed between the microelectrode and the SCN neuronal membrane, the membrane was ruptured using gentle suction and the calcium probe diffused into the neuron filling both the soma and dendrites. Quantitative ratiometric measurements of the intracellular calcium concentration were recorded simultaneously with membrane potential or current. Using these methods it is possible to study the role of changes of the intracellular calcium concentration produced by synaptic activity and action potential firing of individual neurons. In this presentation we demonstrate the methods to simultaneously record electrophysiological activity along with intracellular calcium from individual SCN neurons maintained in brain slices.

  10. A model of propagating calcium-induced calcium release mediated by calcium diffusion

    PubMed Central

    1989-01-01

    The effect of sudden local fluctuations of the free sarcoplasmic [Ca++]i in cardiac cells on calcium release and calcium uptake by the sarcoplasmic reticulum (SR) was calculated with the aid of a simplified model of SR calcium handling. The model was used to evaluate whether propagation of calcium transients and the range of propagation velocities observed experimentally (0.05-15 mm s(-1)) could be predicted. Calcium fluctuations propagate by virtue of focal calcium release from the SR, diffusion through the cytosol (which is modulated by binding to troponin and calmodulin and sequestration by the SR), and subsequently induce calcium release from adjacent release sites of the SR. The minimal and maximal velocities derived from the simulation were 0.09 and 15 mm s(-1) respectively. The method of solution involved writing the diffusion equation as a difference equation in the spatial coordinates. Thus, coupled ordinary differential equations in time with banded coefficients were generated. The coupled equations were solved using Gear's sixth order predictor-corrector algorithm for stiff equations with reflective boundaries. The most important determinants of the velocity of propagation of the calcium waves were the diastolic [Ca++]i, the rate of rise of the release, and the amount of calcium released from the SR. The results are consistent with the assumptions that calcium loading causes an increase in intracellular calcium and calcium in the SR, and an increase in the amount and rate of calcium released. These two effects combine to increase the propagation velocity at higher levels of calcium loading. PMID:2738577

  11. Calcium bioavailability and kinetics of calcium ascorbate and calcium acetate in rats.

    PubMed

    Cai, Jianwei; Zhang, Qinmin; Wastney, Meryl E; Weaver, Connie M

    2004-01-01

    The objective was to investigate the bioavailability and mechanism of calcium absorption of calcium ascorbate (ASC) and calcium acetate (AC). A series of studies was performed in adult Sprague-Dawley male rats. In the first study, each group of rats (n = 10/group) was assigned to one of the five test meals labeled with (45)Ca: (i) 25 mg calcium as heated ASC or (ii) unheated ASC, (iii) 25 mg calcium as unheated AC, (iv) 3.6 mg Ca as unheated ASC, or (v) unheated AC. Femur uptake indicated better calcium bioavailability from ASC than AC at both calcium loads. A 5-min heat treatment partly reduced bioavailability of ASC. Kinetic studies were performed to further investigate the mechanism of superior calcium bioavailability from ASC. Two groups of rats (n = 10/group) received oral doses of 25 mg Ca as ASC or AC. Each dose contained 20 micro Ci (45)Ca. Two additional groups of rats (n = 10/group) received an intravenous injection (iv) of 10 micro Ci (45)Ca after receiving an unlabeled oral dose of 25 mg calcium as ASC or AC. Sequential blood samples were collected over 48 hrs. Urine and fecal samples were collected every 12 hrs for 48 hrs and were analyzed for total calcium and (45)Ca content. Total calcium and (45)Ca from serum, urine, and feces were fitted by a compartment kinetics model with saturable and nonsaturable absorption pathways by WinSAAM (Windows-based Simulation Analysis and Modeling). The difference in calcium bioavailability between the two salts was due to differences in saturable rather than passive intestinal absorption and not to endogenous secretion or calcium deposition rate. The higher bioavailability of calcium ascorbate was due to a longer transit time in the small intestine compared with ASC.

  12. Calcium signalling and calcium channels: evolution and general principles.

    PubMed

    Verkhratsky, Alexei; Parpura, Vladimir

    2014-09-15

    Calcium as a divalent cation was selected early in evolution as a signaling molecule to be used by both prokaryotes and eukaryotes. Its low cytosolic concentration likely reflects the initial concentration of this ion in the primordial soup/ocean as unicellular organisms were formed. As the concentration of calcium in the ocean subsequently increased, so did the diversity of homeostatic molecules handling calcium. This includes the plasma membrane channels that allowed the calcium entry, as well as extrusion mechanisms, i.e., exchangers and pumps. Further diversification occurred with the evolution of intracellular organelles, in particular the endoplasmic reticulum and mitochondria, which also contain channels, exchanger(s) and pumps to handle the homeostasis of calcium ions. Calcium signalling system, based around coordinated interactions of the above molecular entities, can be activated by the opening of voltage-gated channels, neurotransmitters, second messengers and/or mechanical stimulation, and as such is all-pervading pathway in physiology and pathophysiology of organisms.

  13. Effects of Calcium-Vitamin D and Calcium-Alone on Pain Intensity and Menstrual Blood Loss in Women with Primary Dysmenorrhea: A Randomized Controlled Trial.

    PubMed

    Zarei, Somayeh; Mohammad-Alizadeh-Charandabi, Sakineh; Mirghafourvand, Mojgan; Javadzadeh, Yousef; Effati-Daryani, Fatemeh

    2017-01-01

    There is limited evidence on effectiveness of calcium and vitamin D on dysmenorrhea. The authors aimed to determine the effect of combined calcium-vitamin D and calcium-alone on pain intensity and menstrual blood loss in women with primary dysmenorrhea. A randomized double-blind trial. Dormitories of Tabriz University of Medical Sciences. 85 students with moderate or severe primary dysmenorrhea. Participants were randomized into three groups: receiving one tablet/day of 1000 mg calcium + 5000 IU vitamin D3, calcium-alone 1000 mg, or matched placebo, from 15th cycle day until menstrual pain disappearance in the following cycle, for three cycles. Pain intensity and menstrual blood loss were assessed one cycle before, three cycles under, and one cycle following intervention using 10-cm visual analog scale and pictorial blood loss assessment chart, respectively. The groups were compared using repeated measures ANOVA. Time after intervention and interaction of time with group had no significant effects on the outcomes. Compared to the placebo group, mean pain intensity was lower in the both calcium-vitamin D (adjusted difference -0.7, 95% confidence interval -1.6 to 0.3) and calcium-alone (-1.6, -2.6 to -0.6) groups, but the difference was statistically significant only in the calcium-alone group. Menstrual blood loss was not significantly different in the either calcium-vitamin D (-4.7, -21.9 to 12.4) or calcium-alone (-0.4, -17.4 to 16.4) groups compared to placebo. Intake of the calcium-alone was effective in reducing menstrual pain intensity. The results could not indicate significant effects of calcium-vitamin D on the pain or any of the interventions on menstrual blood loss. This study was approved by the Ethics committee of Tabriz University of Medical Sciences (code 92145) and registered at the Iranian Registry of Clinical Trials with IRCT201402043706N21.

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

    PubMed Central

    Wilson, Rosamund J; Copley, J Brian

    2017-01-01

    Background 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. Scope 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. Findings 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. Conclusion 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. PMID:28182142

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

    PubMed

    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.

  16. Preimplantation genetic diagnosis in patients with male meiotic abnormalities.

    PubMed

    Aran, B; Veiga, A; Vidal, F; Parriego, M; Vendrell, J M; Santaló, J; Egozcue, J; Barri, P N

    2004-04-01

    Indications and candidates for preimplantation genetic diagnosis (PGD) have increased in recent years. This study evaluates whether IVF-intracytoplasmic sperm injection (ICSI) results could be improved by selecting embryos through PGD-AS (aneuploidy screening) in couples in whom the male partner presents meiotic abnormalities. Two hundred and fifty-six embryos were biopsied and 183 were suitable for analysis (73.2%). Ninety-two embryos showed normal chromosomal analysis (50.3% of the analysed embryos and 57.5% of the diagnosed embryos). Pregnancy, abortion and implantation rates were compared with 66 IVF-ICSI cycles performed in 44 patients with meiotic abnormalities without PGD (control group). No statistically significant differences in the pregnancy rate (52 versus 43.9%), implantation rate (32.1 versus 23.5%) and miscarriage rate (15.4 versus 10.3%) were observed between the groups. Although the embryos obtained from men with meiotic abnormalities showed a high frequency of chromosome abnormalities, no improvements in pregnancy and implantation rates were obtained after PGD-AS in the series analysed.

  17. Quantifying the abnormal hemodynamics of sickle cell anemia

    NASA Astrophysics Data System (ADS)

    Lei, Huan; Karniadakis, George

    2012-02-01

    Sickle red blood cells (SS-RBC) exhibit heterogeneous morphologies and abnormal hemodynamics in deoxygenated states. A multi-scale model for SS-RBC is developed based on the Dissipative Particle Dynamics (DPD) method. Different cell morphologies (sickle, granular, elongated shapes) typically observed in deoxygenated states are constructed and quantified by the Asphericity and Elliptical shape factors. The hemodynamics of SS-RBC suspensions is studied in both shear and pipe flow systems. The flow resistance obtained from both systems exhibits a larger value than the healthy blood flow due to the abnormal cell properties. Moreover, SS-RBCs exhibit abnormal adhesive interactions with both the vessel endothelium cells and the leukocytes. The effect of the abnormal adhesive interactions on the hemodynamics of sickle blood is investigated using the current model. It is found that both the SS-RBC - endothelium and the SS-RBC - leukocytes interactions, can potentially trigger the vicious ``sickling and entrapment'' cycles, resulting in vaso-occlusion phenomena widely observed in micro-circulation experiments.

  18. Abnormal dissolutions of chlorpromazine hydrochloride tablets in water by paddle method under a high agitation condition.

    PubMed

    Aoyagi, Nobuo; Rimando, Annie Policarpio; Izutsu, Kenichi; Katori, Noriko; Kojima, Shigeo

    2003-09-01

    All sugar-coated tablets of chlorpromazine hydrochloride except for those produced by one manufacture showed concave dissolution profiles in water by paddle method at 100 rpm but not at 50 rpm. The study was undertaken to clarify the agitation-dependent abnormal dissolutions. The strange dissolutions were also observed in water at different ionic strengths but not in buffer solutions of pH 1.2, 4.0 and 6.8. When monitored, the pH's of water in dissolution vessels for the abnormal tablets increased with time at 100 rpm and some of them exceeded pH 8 but did not at 50 rpm. The solubility of chlorpromazine hydrochloride decreased with the increase of pH which was too low to dissolve the whole amount of drug contained in a tablet at pH 8. The elevation of pH seemed to be mainly brought about by dissolution of calcium carbonate popularly used for sugar-coated tablets, because larger amount of calcium ion was dissolved out from the abnormal tablets at 100 rpm than from a normal tablet and from them at 50 rpm. These findings indicate that the concave dissolution profiles should be caused by the decrease of drug solubility with increase in pH of water, probably because of dissolution of calcium carbonate. We should pay attention to the change in pH of water which may differ depending on the agitation speed of dissolution tests.

  19. Intracellular calcium and the relationship to contractility in an avian model of heart failure

    PubMed Central

    Kim, C. S.; Doye, A. A.; Davidoff, A. J.; Maki, T. M.

    2005-01-01

    Global contractile heart failure was induced in turkey poults by furazolidone feeding (700 ppm). Abnormal calcium regulation appears to be a key factor in the pathophysiology of heart failure, but the cellular mechanisms contributing to changes in calcium fluxes have not been clearly defined. Isolated ventricular myocytes from non-failing and failing hearts were therefore used to determine whether the whole heart and ventricular muscle contractile dysfunctions were realized at the single cell level. Whole cell current- and voltage-clamp techniques were used to evaluate action potential configurations and L-type calcium currents, respectively. Intracellular calcium transients were evaluated in isolated myocytes with fura-2 and in isolated left ventricular muscles using aequorin. Action potential durations were prolonged in failing myocytes, which correspond to slowed cytosolic calcium clearing. Calcium current-voltage relationships were normal in failing myocytes; preliminary evidence suggests that depressed transient outward potassium currents contribute to prolonged action potential durations. The number of calcium channels (as measured by radioligand binding) were also similar in non-failing and failing hearts. Isolated ventricular muscles from failing hearts had enhanced inotropic responses, in a dose-dependent fashion, to a calcium channel agonist (Bay K 8644). These data suggest that changes in intracellular calcium mobilization kinetics and longer calcium-myofilament interaction may be able to compensate for contractile failure. We conclude that the relationship between calcium current density and sarcoplasmic reticulum calcium release is a dynamic process that may be altered in the setting of heart failure at higher contraction rates. PMID:10935520

  20. Imprint of Serpentinization Processes on Calcium Isotope Signatures

    NASA Astrophysics Data System (ADS)

    Schwarzenbach, E. M.; Gussone, N. C.; John, T.

    2016-12-01

    Serpentinization of ultramafic rocks has major implications on many global geochemical cycles and controls the transport of various elements (e.g. C, S, B, H2O) from the surficial reservoirs into the mantle. The interaction of water with ultramafic rocks results in Ca-rich (up to 120 mg/L), alkaline (pH 9-12) fluids that support chemolithoautotrophy through the production of hydrogen and methane. In addition, the unique fluid chemistry causes extensive carbonate precipitation in both oceanic peridotite-hosted hydrothermal systems and in continental serpentinization environments. Thus, serpentinization has a major impact on the global carbon cycle, which itself is strongly coupled to the calcium cycle. However, the source of calcium in peridotite-hosted hydrothermal systems is still unclear, and ultramafic rocks typically have low calcium concentrations. Here, we use calcium stable isotope systematics to identify fluid reaction pathways and fluid sources in peridotite-hosted hydrothermal systems. Calcite-veined serpentinites from the Iberian Margin (Ocean Drilling Program (ODP) Leg 149) have a large variation in δ44/40Ca values, which increase with depth and correlate negatively with total carbon contents. In contrast, serpentinites from the 15°20'N Fracture Zone (ODP Leg 209) show a narrow range in δ44/40Ca values. The δ44/40Ca values are overall higher than altered MOR basalts and high pressure serpentinites. These calcium isotope data provide new constraints on fluid cycling in peridotite-hosted hydrothermal systems and sheds new light on the importance of mafic intrusions within seawater-exposed ultramafic rocks.

  1. Sensitivity and specificity of 24-hour urine chemistry levels for detecting elevated calcium oxalate and calcium phosphate supersaturation

    PubMed Central

    Rossi, M. Adrian; Singer, Eric A; Golijanin, Dragan J; Monk, Rebeca D; Erturk, Erdal; Bushinsky, David A

    2008-01-01

    Objectives The gold standard for determining likelihood of calcium oxalate (CaOx) and calcium phosphate (CaPhos) stone formation in urine is supersaturation of CaOx and CaPhos. Our objective was to investigate whether traditional measurement of total calcium, oxalate and phosphate in a 24-hour urine collection is sufficiently sensitive and specific for detecting elevated supersaturation to preclude the more expensive supersaturation test. Methods We performed a retrospective review of 150 consecutive patients with nephrolithiasis who underwent measurement of CaOx supersaturation (CaOxSS) and CaPhos supersaturation (CaPhosSS), as well as total calcium, oxalate and phosphate in a 24-hour urine collection. We used various cut-off values to determine sensitivity and specificity of 24-hour urine measurements for detecting elevated CaOxSS and CaPhosSS. Results In men and women, the sensitivity of 24-hour calcium for detecting elevated CaOxSS was 71% and 79%, respectively; for oxalate, sensitivity was 59% and 36%, respectively. In men and women, the sensitivity of 24-hour calcium for detecting elevated CaPhosSS was 74% and 88%, respectively; for phosphate, sensitivity was 57% and 8%, respectively. In men and women, the specificity of 24-hour calcium for detecting elevated CaOxSS was 55% and 48%, respectively; it was 60% for detecting elevated CaPhosSS in both men and women. Conclusion Traditional 24-hour urine analysis is sensitive, but not specific, for detecting elevated CaOxSS and CaPhosSS. Most patients with abnormal 24-hour urine analysis have normal supersaturation, and treatment decisions based on traditional urine analysis would lead to overtreatment in these patients. PMID:18542745

  2. Ultrastructure of the calcium-sequestering gastrodermal cell in the hydroid Hydractinia symbiolongicarpus (Cnidaria, Hydrozoa).

    PubMed

    Dandar-Roh, Alicia M; Rogers-Lowery, Constance L; Zellmann, Erhard; Thomas, Mary Beth

    2004-05-01

    Large, free-floating crystals of calcium carbonate occur in vacuoles of gastrodermal cells of the hydroid Hydractinia symbiolongicarpus. Here, morphological details about the process by which these cells accumulate and sequester calcium are provided by a cytochemical method designed to demonstrate calcium at the ultrastructural level. Electron-dense material presumably indicative of the presence of calcium was EGTA-sensitive and was shown by parallel electron energy loss spectroscopy (EELS) and energy spectroscopic imaging (ESI) to contain calcium. Calcium occurred in only one cell type, the endodermally derived gastrodermal cell. In these cells, the electron-dense material appeared first as a fine precipitate in the cytosol and nucleus and later as larger deposits and aggregates in the vacuole. During the life cycle, gastrodermal cells of the uninduced planula and the planula during metamorphic induction sequestered calcium. In primary polyps and polyps from established colonies, gastrodermal cells sequestered calcium, but the endodermal secretory cells did not. Our observations support the hypothesis that gastrodermal cells function as a physiological sink for calcium that enters the organism in conjunction with calcium-requiring processes such as motility, secretion, and metamorphosis. Copyright 2004 Wiley-Liss, Inc.

  3. Endocrine and musculoskeletal abnormalities in patients with Down syndrome.

    PubMed

    Hawli, Yousra; Nasrallah, Mona; El-Hajj Fuleihan, Ghada

    2009-06-01

    Down syndrome has a prevalence of one in 500 to one in 1,000 live births and is the most common cause of mental retardation. Most patients are treated in childhood and adolescence for mental or growth retardation. Studies that evaluate bone mass in Down syndrome are limited, and many are small case series in pediatric and adult populations who live either in the community or in residential institutions. Several environmental and hormonal factors contribute to low bone mineral density in such patients. Muscle hypotonia, low amounts of physical activity, poor calcium and vitamin D intakes, hypogonadism, growth retardation and thyroid dysfunction contribute to substantial impairments in skeletal maturation and bone-mass accrual that predispose these patients to fragility fractures. Here, we review indications and limitations of bone-mass measurements in children, summarize the endocrine and skeletal abnormalities in patients presenting with Down syndrome, and review studies that investigate therapeutic strategies for such patients.

  4. Calcium and bone health--goodbye, calcium supplements?

    PubMed

    Ströhle, A; Hadji, P; Hahn, A

    2015-10-01

    This review assesses (1) the potential role of calcium supplements in the prevention and treatment of osteoporosis and osteoporotic fractures, and (2) the safety of calcium supplements with respect to cardiovascular health as well. With regard to (1), a total calcium intake of < 800 mg/day is associated with increased loss of bone mineral density in peri- and postmenopausal women with an increase in fracture risk. Hereby, the effect of calcium supplements on fracture prevention is dependent primary on baseline calcium intake. The strongest protective effect has been reported in individuals with a calcium intake < 700 mg/day and in high-risk groups. A calcium intake of about 1000-1200 mg/day seems to be sufficient for general fracture prevention. With regard to (2), an analysis of the data based on the Hill criteria does not demonstrate convincing evidence that calcium supplements increase cardiovascular risk. In the long term, total calcium intake of 2500 mg/day (from food and supplements) continues to be classified as safe. This value should not be exceeded for an extended period of time.

  5. [Milk of calcium renal stone: echographic diagnosis].

    PubMed

    Virgili, G; Rosi, P; Tamburro, F; Valitutti, M; Torelli, F; Vespasiani, G; Porena, M

    1996-12-01

    "Milk of calcium renal stone" (liquid renal calculosis) is a quite uncommon lithiasis distinguished by the presence of a semiliquid suspension of calcium salts or a "seed-like" sediment in a caliceal diverticulum or an ectasia segment of the collecting system. We reviewed 5 patients (1 male and 4 females, mean age 48.6 years), with a history of urinary tract infection, renal pain or haematuria. All patients underwent renal ultrasonographic assessment in both clinostatic and orthostatic position. Three patients underwent intravenous pyelography before ultrasound. Ultrasonography showed a sonolucent "levelled" image with a posterior acoustic shadow inside a hydro-caliceal dilation (2 pts.) or caliceal diverticulum (3 pts.); the persistence of the "level" in both clinostatic and orthostatic position allowed an immediate diagnosis in all patients. Intravenous pyelography performed before renal ultrasound showed no abnormality in 1 patient and was misleading in two; it otherwise confirmed the diagnosis when performed after renal ultrasonography. Three patients underwent surgery, two patients refused therapy; sonographic follow-up showed no evolution of the morphologic picture. Once considered as exceptional, liquid renal calculosis still remains rare pathology and accounts for 0.6% of all the urinary lithiasis diagnosed by ultrasound in our series. An accurate sonographic assessment allows a reliable diagnosis of this particular lithiasis and an easy discrimination from solid lithiasis, nephrocalcinosis, medullary sponge kidney and hydropyonephrosis. Hence, a correct diagnosis of this rare condition lets uneffective and improper treatments be avoided.

  6. Bioinspired colorimetric detection of calcium(II) ions in serum using calsequestrin-functionalized gold nanoparticles.

    PubMed

    Kim, Sunghyun; Park, Jeong Won; Kim, Dongkyu; Kim, Daejin; Lee, In-Hyun; Jon, Sangyong

    2009-01-01

    Seeing is sensing: Calsequestrin (CSQ) functionalized gold nanoparticles undergo calcium-dependent CSQ polymerization, which results in a clear color change (see picture) together with precipitation. The sensing system is specific for Ca(2+) ions and the differences between normal and disease-associated abnormal (hypercalcemia) Ca(2+) ion levels in serum can be distinguished with the naked eye.

  7. Congenital abnormalities and multiple sclerosis.

    PubMed

    Ramagopalan, Sreeram V; Guimond, Colleen; Criscuoli, Maria; Dyment, David A; Orton, Sarah-Michelle; Yee, Irene M; Ebers, George C; Sadovnick, Dessa

    2010-11-16

    There is a strong maternal parent-of-origin effect in determining susceptibility to multiple sclerosis (MS). One hypothesis is that an abnormal intrauterine milieu leading to impaired fetal development could plausibly also result in increased susceptibility to MS. A possible marker for this intrauterine insult is the presence of a non-fatal congenital anomaly. We investigated whether or not congenital anomalies are associated with MS in a population-based cohort. We identified 7063 MS index cases and 2655 spousal controls with congenital anomaly information from the Canadian Collaborative Project on Genetic Susceptibility to MS (CCPGSMS). The frequency of congenital anomalies were compared between index cases and controls. No significant differences were found. Congenital anomalies thus do not appear to be associated with MS. However, we did not have complete data on types and severity of congenital anomalies or on maternal birth history and thus this study should be regarded as preliminary.

  8. Intradialytic and interdialytic effects of treatment with 1.25 and 1. 75 Mmol/L of calcium dialysate on arterial compliance in patients on hemodialysis.

    PubMed

    Kyriazis, J; Stamatiadis, D; Mamouna, A

    2000-06-01

    Arterial compliance (AC) is an important determinant of vascular structure, and abnormalities of AC can greatly affect the cardiovascular system. Given the vasoconstrictive properties of increased levels of serum ionized calcium (iCa), we investigated the way that dialysate calcium level can influence AC in the hemodialysis (HD) population. In a crossover randomized design, 19 dialysis patients undergoing regular bicarbonate HD (three times weekly) underwent two cycles of four successive HD sessions each with a low (LdCa; 1.25 mmol/L) and high dialysate calcium concentration (HdCa; 1.75 mmol/L). At the fourth session of each cycle, iCa level and hemodynamic parameters (systolic blood pressure [SBP], diastolic blood pressure, mean arterial pressure [MAP], pulse pressure [PP], heart rate, and AC) were measured pre-HD and post-HD. AC was measured noninvasively at the brachial artery by arterial pulse waveform analysis. The dialysate calcium level was a significant determinant of both pre-HD (r = 0.335; P < 0.05) and post-HD iCa level (r = 0.767; P < 0.001). Pre-HD AC increased significantly (P < 0.05) by 0.01+/- 0.02 mL/mm Hg (7% +/- 19%) on switching from HdCa to LdCa treatment. Multiple regression analysis showed that both pre-HD PP and iCa level were major inverse determinants of pre-HD AC in both the LdCa (R(2) = 0.65; P < 0.001) and HdCa (R(2) = 0.51; P < 0.01) treatment groups. AC increased by 32% (P < 0.01) and 37% (P < 0.05) during LdCa and HdCa dialysis, respectively. Intradialytic changes in AC were inversely correlated with changes in SBP and PP. In the HdCa group, changes in iCa level related significantly to MAP (r = 0.464; P < 0.05). The results show that changes in AC during HD are mainly mediated through concurrent changes of systemic hemodynamics, which are largely affected by dialysate calcium level through parallel changes in iCa level. Interdialytically, a significant, blood pressure-independent, inverse relationship between AC and iCa level exists

  9. Theoretical aspects of calcium signaling

    NASA Astrophysics Data System (ADS)

    Pencea, Corneliu Stefan

    2001-08-01

    Experiments investigating intracellular calcium dynamics have revealed that calcium signals differentially affect a variety of intracellular processes, from fertilization and cell development and differentiation to subsequent cellular activity, ending with cell death. As an intracellular messenger, calcium transmits information within and between cells, thus regulating their activity. To control such a variety of processes, calcium signals have to be very flexible and also precisely regulated. The cell uses a calcium signaling ``toolkit'', where calcium ions can act in different contexts of space, amplitude and time. For different tasks, the cell selects the particular signal, or combination of signals, that triggers the appropriate physiological response. The physical foundations of such a versatile cellular signaling toolkit involving calcium are not completely understood, despite important experimental and theoretical progress made recently. The declared goal of this work is to investigate physical mechanisms on which the propagation of differential signals can be based. The dynamics of calcium near a cluster of inositol trisphosphate (IP3) activated calcium channels has been investigated analytically and numerically. Our work has demonstrated that clusters of different IP3 receptors can show similar bistable behavior, but differ in both the transient and long term dynamics. We have also investigated the conditions under which a calcium signal propagates between a pair of localized stores. We have shown that the propagation of the signal across a random distribution of such stores shows a percolation transition manifested in the shape of the wave front. More importantly, our work indicates that specific distribution of stores can be interpreted as calcium circuits that can perform important signal analyzing task, from unidirectional propagation and coincidence detection to a complete set of logic gates. We believe that phenomena like the ones described are

  10. Calcium nutrition and metabolism during infancy.

    PubMed

    Bass, J Kirk; Chan, Gary M

    2006-10-01

    Calcium is a vital mineral for the developing newborn infant. This review discusses perinatal and neonatal calcium metabolism, with an emphasis on enteral calcium absorption and the nutritional factors affecting calcium bioavailability including the three major endocrine hormones involved in calcium metabolism: parathyroid hormone, vitamin D, and calcitonin. The placenta transports calcium to the fetus throughout pregnancy, with the largest amount of fetal calcium accumulation occurring in the third trimester. At birth, the newborn transitions to intestinal absorption to meet the body's calcium needs. Most calcium is absorbed by paracellular passive diffusion in the small intestine. Calcium intestinal absorption is affected by the type and amount of calcium ingested. It is also affected by the amount of intestinal calcium that is bound to dietary fats and proteins. One major consequence of decreased calcium absorption is metabolic bone disease in which there is a failure of complete mineralization of the bone osteoid.

  11. Thiosulfate Reduces Calcium Phosphate Nephrolithiasis

    PubMed Central

    Asplin, John R.; Donahue, Susan E.; Lindeman, Christina; Michalenka, Anne; Strutz, Kelly Laplante; Bushinsky, David A.

    2009-01-01

    An uncontrolled trial reported that sodium thiosulfate reduces formation of calcium kidney stones in humans, but this has not been established in a controlled human study or animal model. Using the genetic hypercalciuric rat, an animal model of calcium phosphate stone formation, we studied the effect of sodium thiosulfate on urine chemistries and stone formation. We fed genetic hypercalciuric rats normal food with or without sodium thiosulfate for 18 wk and measured urine chemistries, supersaturation, and the upper limit of metastability of urine. Eleven of 12 untreated rats formed stones compared with only three of 12 thiosulfate-treated rats (P < 0.002). Urine calcium and phosphorus were higher and urine citrate and volume were lower in the thiosulfate-treated rats, changes that would increase calcium phosphate supersaturation. Thiosulfate treatment lowered urine pH, which would lower calcium phosphate supersaturation. Overall, there were no statistically significant differences in calcium phosphate supersaturation or upper limit of metastability between thiosulfate-treated and control rats. In vitro, thiosulfate only minimally affected ionized calcium, suggesting a mechanism of action other than calcium chelation. In summary, sodium thiosulfate reduces calcium phosphate stone formation in the genetic hypercalciuric rat. Controlled trials testing the efficacy and safety of sodium thiosulfate for recurrent kidney stones in humans are needed. PMID:19369406

  12. Cardiovascular effects of calcium supplements.

    PubMed

    Reid, Ian R

    2013-07-05

    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.

  13. Revisiting intracellular calcium signaling semantics.

    PubMed

    Haiech, Jacques; Audran, Emilie; Fève, Marie; Ranjeva, Raoul; Kilhoffer, Marie-Claude

    2011-12-01

    Cells use intracellular free calcium concentration changes for signaling. Signal encoding occurs through both spatial and temporal modulation of the free calcium concentration. The encoded message is detected by an ensemble of intracellular sensors forming the family of calcium-binding proteins (CaBPs) which must faithfully translate the message using a new syntax that is recognized by the cell. The cell is home to a significant although limited number of genes coding for proteins involved in the signal encoding and decoding processes. In a cell, only a subset of this ensemble of genes is expressed, leading to a genetic regulation of the calcium signal pathways. Calmodulin (CaM), the most ubiquitous expressed intracellular calcium-binding protein, plays a major role in calcium signal translation. Similar to a hub, it is central to a large and finely tuned network, receiving information, integrating it and dispatching the cognate response. In this review, we examine the different steps starting with an external stimulus up to a cellular response, with special emphasis on CaM and the mechanism by which it decodes calcium signals and translates it into exquisitely coordinated cellular events. By this means, we will revisit the calcium signaling semantics, hoping that we will ease communication between scientists dealing with calcium signals in different biological systems and different domains.

  14. The bioavailability of dietary calcium.

    PubMed

    Guéguen, L; Pointillart, A

    2000-04-01

    This update focuses on the bioavailability of dietary calcium for humans. Fundamentals of calcium metabolism, intestinal absorption, urinary excretion and balance are recalled. Dietary factors, especially lactose and other milk components, influencing calcium bioavailability at intestinal and renal levels are reviewed. A critical examination of all the methods used for evaluating calcium bioavailability is made. This includes in vitro assays, classical and isotopic balances, urinary excretion, isotope labeling in the urine, plasma and bones, long term evaluation of bone mineralization and the use of biological bone markers. Importance and advantages of animal models are discussed. The state of the art in the comparative bioavailability of calcium in foods is detailed including a comparison of sources of calcium (dairy products and calcium salts) in human studies and in some animal studies, casein phosphopeptides, proteins, lactose and lactase and their relation with calcium bioavailability (in humans and rats). An update on the consumption of dairy products and bone mass is presented. Emphasis on peculiarities and advantages of calcium in milk and dairy products is given.

  15. 21 CFR 184.1201 - Calcium glycerophosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium glycerophosphate. 184.1201 Section 184... as GRAS § 184.1201 Calcium glycerophosphate. (a) Calcium glycerophosphate (C3H7CaO6P, CAS Reg. No...

  16. Dietary calcium and magnesium in the development of hypertension in the spontaneously hypertensive rat

    SciTech Connect

    Evans, G.; Weaver, C.M.; Harrington, D.D.; Babbs, C.F.

    1986-03-01

    The role of dietary calcium and magnesium in attenuation of hypertension was studied in 9 groups of 9 spontaneously hypertensive rats ages 8 to 31 weeks. The animals were fed AIN 76 semipurified diets altered in calcium (0.075%, 0.5%, and 2.5%) and magnesium (0.01%, 0.05%, and 0.75%) using a 3 x 3 factorial design. An inverse relationship between dietary calcium and systolic blood pressure as determined by the photoelectric tail cuff method became significant (p<0.05) after 12 weeks. Repeated measures analysis of variance indicated that dietary magnesium had no effect on systolic blood pressure; no calcium x magnesium interaction was observed. Total and ultrafiltrable serum calcium had a significant inverse correlation with blood pressure (-0.4642, p = .001 and -0.5568, p = .001 respectively). Total and ultrafiltrable serum magnesium reflected dietary magnesium concentration. Magnesium deficiency signs, deposition of calcium in kidneys, and histological lesions were observed in high calcium fed groups receiving normal and low levels of magnesium. Thus, a lowering of blood pressure by calcium supplementation without concomitant magnesium supplementation was accompanied by biochemical and histologic abnormalities in this animal model.

  17. The interactive roles of zinc and calcium in mitochondrial dysfunction and neurodegeneration

    PubMed Central

    Pivovarova, Natalia B.; Stanika, Ruslan I.; Kazanina, Galina; Villanueva, Idalis; Andrews, S. Brian

    2013-01-01

    Zinc has been implicated in neurodegeneration following ischemia. In analogy to calcium, zinc has been proposed to induce toxicity via mitochondrial dysfunction, but the relative role of each cation in mitochondrial damage is unclear. Here we report that under conditions mimicking ischemia in hippocampal neurons — normal (2 mM) calcium plus elevated (>100 μM) exogenous zinc — mitochondrial dysfunction evoked by glutamate, kainate or direct depolarization is, despite significant zinc uptake, primarily governed by calcium. Thus, robust mitochondrial ion accumulation, swelling, depolarization and ROS generation were only observed after toxic stimulation in calcium-containing media. This contrasts with the lack of any mitochondrial response in zinc-containing but calcium-free medium, even though zinc uptake and toxicity were strong under these conditions. Indeed, abnormally high, ionophore-induced zinc uptake was necessary to elicit any mitochondrial depolarization. In calcium- and zinc-containing media, depolarization-induced zinc uptake facilitated cell death and enhanced accumulation of mitochondrial calcium, which localized to characteristic matrix precipitates. Some of these contained detectable amounts of zinc. Together these data indicate that zinc uptake is generally insufficient to trigger mitochondrial dysfunction, so that mechanism(s) of zinc toxicity must be different from that of calcium. PMID:24127746

  18. The interactive roles of zinc and calcium in mitochondrial dysfunction and neurodegeneration.

    PubMed

    Pivovarova, Natalia B; Stanika, Ruslan I; Kazanina, Galina; Villanueva, Idalis; Andrews, S Brian

    2014-02-01

    Zinc has been implicated in neurodegeneration following ischemia. In analogy with calcium, zinc has been proposed to induce toxicity via mitochondrial dysfunction, but the relative role of each cation in mitochondrial damage remains unclear. Here, we report that under conditions mimicking ischemia in hippocampal neurons - normal (2 mM) calcium plus elevated (> 100 μM) exogenous zinc - mitochondrial dysfunction evoked by glutamate, kainate or direct depolarization is, despite significant zinc uptake, primarily governed by calcium. Thus, robust mitochondrial ion accumulation, swelling, depolarization, and reactive oxygen species generation were only observed after toxic stimulation in calcium-containing media. This contrasts with the lack of any mitochondrial response in zinc-containing but calcium-free medium, even though zinc uptake and toxicity were strong under these conditions. Indeed, abnormally high, ionophore-induced zinc uptake was necessary to elicit any mitochondrial depolarization. In calcium- and zinc-containing media, depolarization-induced zinc uptake facilitated cell death and enhanced accumulation of mitochondrial calcium, which localized to characteristic matrix precipitates. Some of these contained detectable amounts of zinc. Together these data indicate that zinc uptake is generally insufficient to trigger mitochondrial dysfunction, so that mechanism(s) of zinc toxicity must be different from that of calcium. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  19. Extracellular calcium sensing and extracellular calcium signaling

    NASA Technical Reports Server (NTRS)

    Brown, E. M.; MacLeod, R. J.; O'Malley, B. W. (Principal Investigator)

    2001-01-01

    , localized changes in Ca(o)(2+) within the ECF can originate from several mechanisms, including fluxes of calcium ions into or out of cellular or extracellular stores or across epithelium that absorb or secrete Ca(2+). In any event, the CaR and other receptors/sensors for Ca(o)(2+) and probably for other extracellular ions represent versatile regulators of numerous cellular functions and may serve as important therapeutic targets.

  20. Breathing abnormalities in sleep in achondroplasia.

    PubMed Central

    Waters, K A; Everett, F; Sillence, D; Fagan, E; Sullivan, C E

    1993-01-01

    Overnight sleep studies were performed in 20 subjects with achondroplasia to document further the respiratory abnormalities present in this group. Somatosensory evoked potentials (SEPs) were recorded in 19 of the subjects to screen for the presence of brainstem abnormalities, which are one of the potential aetiological mechanisms. Fifteen children aged 1 to 14 years, and five young adults, aged 20 to 31 years were included. All had upper airway obstruction and 15 (75%) had a pathological apnoea index (greater than five per hour). Other sleep associated respiratory abnormalities, including partial obstruction, central apnoea, and abnormal electromyographic activity of accessory muscles of respiration, also showed a high prevalence. SEPs were abnormal in eight (42%), but there was no correlation between abnormal SEPs and apnoea during sleep, either qualitatively or quantitatively. A high prevalence of both sleep related respiratory abnormalities and abnormal SEPs in young subjects with achondroplasia was demonstrated. However, the sleep related respiratory abnormalities do not always result in significant blood gas disturbances or correlate with abnormal SEPs in this group. PMID:8215519

  1. Understanding calcium homeostasis in postnatal gonadotropin-releasing hormone neurons using cell-specific Pericam transgenics.

    PubMed

    Constantin, Stéphanie; Jasoni, Christine; Romanò, Nicola; Lee, Kiho; Herbison, Allan E

    2012-01-01

    The gonadotropin-releasing hormone (GnRH) neurons are the key output cells of a complex neuronal network controlling fertility in mammals. To examine calcium homeostasis in postnatal GnRH neurons, we generated a transgenic mouse line in which the genetically encodable calcium indicator ratiometric Pericam (rPericam) was targeted to the GnRH neurons. This mouse model enabled real-time imaging of calcium concentrations in GnRH neurons in the acute brain slice preparation. Investigations in GnRH-rPericam mice revealed that GnRH neurons exhibited spontaneous, long-duration (~8s) calcium transients. Dual electrical-calcium recordings revealed that the calcium transients were correlated perfectly with burst firing in GnRH neurons and that calcium transients in GnRH neurons regulated two calcium-activated potassium channels that, in turn, determined burst firing dynamics in these cells. Curiously, the occurrence of calcium transients in GnRH neurons across puberty or through the estrous cycle did not correlate well with the assumption that GnRH neuron burst firing was contributory to changing patterns of pulsatile GnRH release at these times. The GnRH-rPericam mouse was also valuable in determining differential mechanisms of GABA and glutamate control of calcium levels in GnRH neurons as well as effects of G-protein-coupled receptors for GnRH and kisspeptin. The simultaneous measurement of calcium levels in multiple GnRH neurons was hampered by variable rPericam fluorescence in different GnRH neurons. Nevertheless, in the multiple recordings that were achieved no evidence was found for synchronous calcium transients. Together, these observations show the great utility of transgenic targeting strategies for investigating the roles of calcium with specified neuronal cell types. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Glucose metabolic abnormality is associated with defective mineral homeostasis in skeletal disorder mouse model.

    PubMed

    Zou, JiangHuan; Xiong, XiWen; Lai, BeiBei; Sun, Min; Tu, Xin; Gao, Xiang

    2015-04-01

    Bone was reported as a crucial organ for regulating glucose homeostasis. In this study, we found that Phex mutant mice (PUG), a model of human X-linked hypophosphatemic rickets (XLH), displayed metabolic abnormality in addition to abnormal phosphate homeostasis, skeletal deformity and growth retardation. Glucose tolerance was elevated with enhanced insulin sensitivity in PUG, though circulating insulin level decreased. Interestingly, bone mineral density defects and glucose metabolic abnormality were both rescued by adding phosphorus- and calcium-enriched supplements in daily diet. Serum insulin level, glucose tolerance and insulin sensitivity showed no differences between PUG and wild-type mice with rescued osteocalcin (OCN) following treatment. Our study suggested that OCN is a potential mediator between mineral homeostasis and glucose metabolism. This investigation brings a new perspective on glucose metabolism regulation through skeleton triggered mineral homeostasis and provides new clues in clinical therapeutics of potential metabolic disorders in XLH patients.

  3. [Severe hypertrophic myocardiopathy in newborn infants. Intra-erythrocyte calcium and the effect of lidoflazine, a calcium-channel inhibitor. Apropos of 2 cases].

    PubMed

    Vliers, A; Stijns-Cailteux, M; Lintermans, J; Trémouroux-Wattiez, M; Godfraind, T

    1984-05-01

    Two cases of severe hypertrophic obstructive cardiomyopathy in the neonate are reported. The first case was poorly tolerated because of predominant stenosis of the right ventricular outflow tract causing right to left shunting through a patent foramen ovale. The second case presented with severe syncope at 6 weeks of age. The first patient was treated with propranolol without any success. Regression of the clinical and electrocardiographic signs was obtained in both cases with lidoflazine, within a few weeks. Red blood cell calcium concentrations were abnormally high in both patients before treatment and returned to normal levels with clinical and echocardiographic improvement. Abnormal accumulation of intracellular calcium in the myocardium is a possible mechanism of this cardiomyopathy. The relation between this type of accumulation and the effects of catecholamine discharge are recalled. The possible initiating role of an enzymatic abnormality of calcium entry is discussed: the chaotic geometric alignment of the myocardial fibres, characteristic of this type of hypertrophy, would therefore be a secondary phenomenon. Once constituted, the hypertrophy would then become irreversible. However, it may be possible to reverse it in the neonate by calcium antagonists as suggested by these two cases.

  4. Mitochondrial oxidative stress during cardiac lipid overload causes intracellular calcium leak and arrhythmia

    PubMed Central

    Joseph, Leroy C.; Subramanyam, Prakash; Radlicz, Christopher; Trent, Chad M.; Iyer, Vivek; Colecraft, Henry M.; Morrow, John P.

    2016-01-01

    Background Diabetes and obesity are associated with an increased risk of arrhythmia and sudden cardiac death. Abnormal lipid accumulation is observed in cardiomyocytes of obese and diabetic patients, which may contribute to arrhythmia, but the mechanisms are poorly understood. A transgenic mouse model of cardiac lipid overload, the PPARg cardiac overexpression mouse, has long QT and increased ventricular ectopy. Objective We evaluated the hypothesis that the increase in ventricular ectopy during cardiac lipid overload is caused by abnormalities in calcium handling due to increased mitochondrial oxidative stress. Methods Ventricular myocytes were isolated from adult mouse hearts to record sparks and calcium transients. Mice were implanted with heart rhythm monitors for in vivo recordings. Results PPARg cardiomyocytes have more frequent triggered activity and increased sparks compared to control. Sparks and triggered activity are reduced by mitotempo, a mitochondrial-targeted antioxidant. This is explained by a significant increase in oxidation of RyR2. Calcium transients are increased in amplitude and SR calcium stores are increased in PPARg cardiomyocytes. Computer modeling of the cardiac action potential demonstrates that long QT contributes to increased SR calcium. Mitotempo decreased ventricular ectopy in vivo. Conclusions During cardiac lipid overload, mitochondrial oxidative stress causes increased SR calcium leak by oxidizing RyR2 channels. This promotes ventricular ectopy, which is significantly reduced in vivo by a mitochondrial-targeted anti-oxidant. These results suggest a potential role for mitochondrial-targeted anti-oxidants to prevent arrhythmia and sudden cardiac death in obese and diabetic patients. PMID:27154230

  5. Williams-Beuren syndrome hypercalcemia: is TRPC3 a novel mediator in calcium homeostasis?

    PubMed

    Letavernier, Emmanuel; Rodenas, Anita; Guerrot, Dominique; Haymann, Jean-Philippe

    2012-06-01

    Williams-Beuren syndrome (WBS) is a neurodevelopmental disorder associated with hypercalcemia of unknown origin. This syndrome results from the deletion of contiguous genes on chromosome 7, including the general transcription factor IIi gene. The general transcription factor IIi gene encodes TFII-I, which suppresses cell-surface accumulation of transient receptor potential C3 (TRPC3) channels, involved in calcium transport in lymphocytes. We describe the case of a patient with WBS with hypercalcemia associated with abnormal TRPC3 expression. Analysis of peripheral lymphocytes revealed a sharp increase in TRPC3 expression, compared with control patients. To investigate the potential role of TRPC3 in calcium homeostasis, we performed specific immunostaining on the intestine and the kidney, major calcium-regulating tissues. We provide the first demonstration that TRPC3 is expressed in normal digestive epithelium and renal tubules in control patients, and overexpressed in the intestine in the patient with WBS. Taken together, these data suggest that calcium metabolism abnormalities observed in WBS may be attributable to TFII-I haploinsufficiency and subsequent TRPC3 overexpression, thereby increasing both digestive and renal calcium absorption. This original observation prompts further investigation of TRPC3 as a novel actor of calcium homeostasis.

  6. Calcium-Responsive Contractility During Fertilization in Sea Urchin Eggs

    PubMed Central

    Stack, Christianna; Lucero, Amy J.; Shuster, Charles B.

    2008-01-01

    Fertilization triggers a reorganization of oocyte cytoskeleton, and in sea urchins there is a dramatic increase in cortical F-actin. However, the role that myosin II plays during fertilization remains largely unexplored. Myosin II is localized to the cortical cytoskeleton both prior to- and following fertilization, and to examine myosin II contractility in living cells, Lytechinus pictus eggs were observed by time-lapse microscopy. Upon sperm binding, a cell surface deflection traversed the egg that was followed- and dependent on the calcium wave. The calcium-dependence of surface contractility could be reproduced in unfertilized eggs, where mobilization of intracellular calcium in unfertilized eggs under compression resulted in a marked contractile response. Lastly, inhibition of myosin II delayed absorption of the fertilization cone, suggesting that myosin II not only responds to the same signals that activate eggs, but also participates in the remodeling of the cortical actomyosin cytoskeleton during the first zygotic cell cycle. PMID:16470603

  7. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium pantothenate, calcium chloride double salt..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may... information required by the Act, the following: (1) The name of the additive “calcium chloride double salt...

  8. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium pantothenate, calcium chloride double salt..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may... information required by the Act, the following: (1) The name of the additive “calcium chloride double salt...

  9. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium pantothenate, calcium chloride double salt..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may... information required by the Act, the following: (1) The name of the additive “calcium chloride double salt...

  10. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium pantothenate, calcium chloride double salt..., calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may... information required by the Act, the following: (1) The name of the additive “calcium chloride double salt...

  11. Effect of calcium on premenstrual syndrome: A double-blind randomized clinical trial

    PubMed Central

    Shobeiri, Fatemeh; Araste, Fahimeh Ezzati; Ebrahimi, Reihaneh; Nazari, Mansour

    2017-01-01

    Objective Premenstrual syndrome (PMS) affects millions of women and is known as the most important disorder among them. The very aim of the present study was to evaluate the effects of low dose calcium on severity of PMS. Methods This study can be considered as a double-blind randomized clinical trial. Female students of Hamadan University of Medical Sciences diagnosed with PMS in 2014 participated in the present study. Sixty-six female students diagnosed with PMS were involved in the experimental and control groups. The participants were randomly assigned into two groups to receive 500 mg of calcium daily or placebo for two months. Severity of PMS was detected by Daily Record of Severity of Problems, which was used to measure symptoms during one menstrual cycle before and two menstrual cycles after the intervention. Results No signifcant differences were observed in the mean scores of PMS symptoms between calcium and placebo groups before the treatment (P=0.74). However, signifcant differences were noticed between the two intervention groups in the first (P=0.01) and second menstrual cycles (P=0.001) after the intervention. The differences were significant in subgroups of anxiety, depression, emotional changes, water retention, and somatic changes in calcium group compared with placebo group in the menstrual cycle before the intervention and two menstrual cycles after the intervention and among menstrual cycles (0, cycle 1, cycle 2) in calcium group (P=0.01). Conclusion Overall, the results of the present study suggest that treatment with calcium supplements is an effective method for reducing mood disorders during PMS. PMID:28217679

  12. Calcium channels and migraine.

    PubMed

    Pietrobon, Daniela

    2013-07-01

    Missense mutations in CACNA1A, the gene that encodes the pore-forming α1 subunit of human voltage-gated Ca(V)2.1 (P/Q-type) calcium channels, cause a rare form of migraine with aura (familial hemiplegic migraine type 1: FHM1). Migraine is a common disabling brain disorder whose key manifestations are recurrent attacks of unilateral headache that may be preceded by transient neurological aura symptoms. This review, first, briefly summarizes current understanding of the pathophysiological mechanisms that are believed to underlie migraine headache, migraine aura and the onset of a migraine attack, and briefly describes the localization and function of neuronal Ca(V)2.1 channels in the brain regions that have been implicated in migraine pathogenesis. Then, the review describes and discusses i) the functional consequences of FHM1 mutations on the biophysical properties of recombinant human Ca(V)2.1 channels and native Ca(V)2.1 channels in neurons of knockin mouse models carrying the mild R192Q or severe S218L mutations in the orthologous gene, and ii) the functional consequences of these mutations on neurophysiological processes in the cerebral cortex and trigeminovascular system thought to be involved in the pathophysiology of migraine, and the insights into migraine mechanisms obtained from the functional analysis of these processes in FHM1 knockin mice. This article is part of a Special Issue entitled: Calcium channels.

  13. Subcutis calcinosis caused by injection of calcium-containing heparin in a chronic kidney injury patient.

    PubMed

    Fatma, Lilia Ben; El Ati, Zohra; Azzouz, Haifa; Rais, Lamia; Krid, Madiha; Smaoui, Wided; Maiz, Hédi Ben; Béji, Soumaya; Zouaghi, Karim; Zitouna, Moncef; Moussa, Fatma Ben

    2014-09-01

    Subcutis calcinosis, characterized by abnormal calcium deposits in the skin, is a rare complication of using calcium-containing heparin occurring in patients with advanced renal failure. We report the case of an 83-year-old female, a known case of chronic kidney disease (CKD) for four years with recent worsening of renal failure requiring hospitalization and hemodialysis. She developed subcutis calcinosis following injection of calcium-containing heparin. Biochemical tests showed serum parathormone level at 400 pg/dL, hypercalcemia, elevated calcium-phosphate product and monoclonal gammopathy related to multiple myeloma. She developed firm subcutaneous nodules in the abdomen and the thighs, the injection sites of Calciparin ® (calcium nadroparin) that was given as a preventive measure against deep vein thrombosis. The diagnosis of subcutis calcinosis was confirmed by the histological examination showing calcium deposit in the dermis and hypodermis. These lesions completely disappeared after discontinuing calcium nadroparin injections. Subcutis calcinosis caused by injections of calcium-containing heparin is rare, and, to the best our knowledge, not more than 12 cases have been reported in the literature. Pathogenesis is not well established but is attributed to the calcium disorders usually seen in advanced renal failure. Diagnosis is confirmed by histological tests. Outcome is mostly favorable. The main differential diagnosis is calciphylaxis, which has a poor prognosis. Even though rarely reported, we should be aware that CKD patients with elevated calcium-phosphorus product can develop subcutis calcinosis induced by calcium-containing heparin. When it occurs, fortunately and unlike calciphylaxis, outcome is favorable.

  14. Skeletal muscle sarcolemma in malignant hyperthermia: evidence for a defect in calcium regulation.

    PubMed

    Mickelson, J R; Ross, J A; Hyslop, R J; Gallant, E M; Louis, C F

    1987-03-12

    contribute to the abnormal calcium homeostasis and altered contractile properties of MHS skeletal muscle.

  15. Immunoglobulin concentrations in cervical mucus in patients with normal and abnormal cervical cytology.

    PubMed

    Coughlan, B M; Skinner, G R

    1977-02-01

    The cervical mucus of 31 patients with normal and 16 patients with abnormal cervical cytology was investigated at each stage of the menstrual cycle for immunoglobulin IgG, IgA and IgM. IgG and IgA were present in every mucus sample, while IgM was only occasionally found in trace amounts. IgG and IgA increased towards the last week of the menstrual cycle, the increase being in general more marked for IgA. Patients with abnormal cervical cytology showed increased IgG and, more strikingly, IgA concentrations in their cervical mucus, but there was no correlation between the IgG and IgA concentrations at any stage of the menstrual cycle. Whereas in patients with normal cervical cytology the IgG and IgA concentrations correlated throughout the menstrual cycle.

  16. Calcium transporters: From fields to the table

    USDA-ARS?s Scientific Manuscript database

    Calcium transporters regulate calcium fluxes within cells. Plants, like all organisms, contain channels, pumps, and exchangers to carefully modulate intracellular calcium levels. This review presents a summary of the recent advances in cloning and characterizing of these transporters and highlight...

  17. Vitamin D, Calcium, and Bone Health

    MedlinePlus

    ... in Balance › Vitamin D, Calcium, and Bone Health 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 ...

  18. Electrocardiographic abnormalities in patients with Lassa fever.

    PubMed

    Cummins, D; Bennett, D; Fisher-Hoch, S P; Farrar, B; McCormick, J B

    1989-10-01

    Electrocardiograms from 32 patients with acute Lassa fever were abnormal in over 70% of cases. The changes noted included non-specific ST-segment and T-wave abnormalities, ST-segment elevation, generalized low-voltage complexes, and changes reflecting electrolyte disturbance. None of the abnormalities correlated with clinical severity of infection, serum transaminase levels, or eventual outcome. ECG changes are common in Lassa fever, but usually unassociated with clinical manifestations of myocarditis.

  19. An Improved Calcium Flame Test.

    ERIC Educational Resources Information Center

    Pearson, Robert S.

    1985-01-01

    Indicates that the true red color of calcium can be obtained (using the procedure described by Sorm and Logowski) if the calcium ion solution is mixed with an equal volume of saturated ammonium bromide solution. Suggestions for flame tests of other elements are also noted. (JN)

  20. Calcium Intake: A Lifelong Proposition.

    ERIC Educational Resources Information Center

    Amschler, Denise H.

    1985-01-01

    This article reviews the current problem of low calcium intake in the United States among all age groups, the role of calcium in the formation and maintenance of bone mass, and major factors influencing absorption. Osteoporosis is discussed, and current recommendations for Recommended Dietary allowance are provided. (Author/MT)

  1. Major Minerals - Calcium, Magnesium, Phosphorus

    USDA-ARS?s Scientific Manuscript database

    Calcium, magnesium and phosphorus are essential elements critically important for the function of the musculoskeletal system, including the formation and transduction of energy and the maintenance of healthy bone. The major calcium concern for physically active healthy middle-aged adults is to consu...

  2. Electrochemical cell with calcium anode

    DOEpatents

    Cooper, John F.; Hosmer, Pamela K.; Kelly, Benjamin E.

    1979-01-01

    An electrochemical cell comprising a calcium anode and a suitable cathode in an alkaline electrolyte consisting essentially of an aqueous solution of an hydroxide and a chloride. Specifically disclosed is a mechanically rechargeable calcium/air fuel cell with an aqueous NaOH/NaCl electrolyte.

  3. Calcium Intake: A Lifelong Proposition.

    ERIC Educational Resources Information Center

    Amschler, Denise H.

    1985-01-01

    This article reviews the current problem of low calcium intake in the United States among all age groups, the role of calcium in the formation and maintenance of bone mass, and major factors influencing absorption. Osteoporosis is discussed, and current recommendations for Recommended Dietary allowance are provided. (Author/MT)

  4. [Bone involvement in idiopathic calcium lithiasis].

    PubMed

    Ghazali, A; Bataille, P; Solal, M C; Marié, A; Brazier, M; Sebert, J L; Prin, L; Fournier, A

    1995-01-01

    Bone involvement in idiopathic calcium nephrolithiasis is characterized by the following abnormalities: a) the bone density is decreased, the severity of bone loss being dependent upon the existence of hypercalciuria and upon the pathophysiology of this latter: it is inconsistent in the absence of hypercalciuria or when hypercalciuria is of the absorptive type I or II, whereas it is almost constant in fasting hypercalciuria without secondary hyperparathyroidism and constant and severe in the rare true renal hypercalciuria. b) The bone histology (which has been evaluated only in idiopathic hypercalciuric patients) mainly shows a defect in bone formation at the exception of the rare renal hypercalciuria. Osteoclastic hyperresorption is only seen in this latter type of hypercalciuria whereas in the other types of hypercalciuria only an increase of the total or inactive resorption surface is observed. This phenomenon is possibly explained only by a delayed refilling of the resorption lacunae secondary to the decreased bone formation. The osteoid thickness is either normal or decreased despite decrease in mineralization apposition rate which seems therefore to be secondary to the decreased bone formation. c) Symptomatic bone disease in hypercalciuric stone formers is exceptional and always related to a severe long term calcium restriction. d) The biochemical markers of bone resorption tend to be increased in idiopathic hypercalciuria. Hydroxyprolinuria is more often elevated than pyridinolinuria. However pyridinolinuria is negatively correlated to bone density. The contrast between the increase of these bone resorption markers and the usual normality of plasma PTH and of the osteoclastic resorptive surfaces, suggest the role of meat induced acid load which may favor inactive resorption by dissolution of bone buffers. A disturbed profile synthesis of cytokines which induce differentiation and proliferation of the osteoclasts and which modulate the osteoblastic

  5. [Cognitive abnormalities and cannabis use].

    PubMed

    Solowij, Nadia; Pesa, Nicole

    2010-05-01

    Evidence that cannabis use impairs cognitive function in humans has been accumulating in recent decades. The purpose of this overview is to update knowledge in this area with new findings from the most recent literature. Literature searches were conducted using the Web of Science database up to February 2010. The terms searched were: "cannabi*" or "marijuana", and "cogniti*" or "memory" or "attention" or "executive function", and human studies were reviewed preferentially over the animal literature. Cannabis use impairs memory, attention, inhibitory control, executive functions and decision making, both during the period of acute intoxication and beyond, persisting for hours, days, weeks or more after the last use of cannabis. Pharmacological challenge studies in humans are elucidating the nature and neural substrates of cognitive changes associated with various cannabinoids. Long-term or heavy cannabis use appears to result in longer-lasting cognitive abnormalities and possibly structural brain alterations. Greater adverse cognitive effects are associated with cannabis use commencing in early adolescence. The endogenous cannabinoid system is involved in regulatory neural mechanisms that modulate processes underlying a range of cognitive functions that are impaired by cannabis. Deficits in human users most likely therefore reflect neuroadaptations and altered functioning of the endogenous cannabinoid system.

  6. [Renal abnormalities in ankylosing spondylitis].

    PubMed

    Samia, Barbouch; Hazgui, Faiçal; Abdelghani, Khaoula Ben; Hamida, Fethi Ben; Goucha, Rym; Hedri, Hafedh; Taarit, Chokri Ben; Maiz, Hedi Ben; Kheder, Adel

    2012-07-01

    We will study the epidemiologic, clinical, biological, therapeutic, prognostic characteristics and predictive factors of development of nephropathy in ankylosing spondylitis patients. We retrospectively reviewed the medical record of 32 cases with renal involvement among 212 cases of ankylosing spondylitis followed in our service during the period spread out between 1978 and 2006. The renal involvement occurred in all patients a mean of 12 years after the clinical onset of the rheumatic disease. Thirty-two patients presented one or more signs of renal involvement: microscopic hematuria in 22 patients, proteinuria in 23 patients, nephrotic syndrome in 11 patients and decreased renal function in 24 patients (75%). Secondary renal amyloidosis (13 patients), which corresponds to a prevalence of 6,1% and tubulointerstitial nephropathy (7 patients) were the most common cause of renal involvement in ankylosing spondylitis followed by IgA nephropathy (4 patients). Seventeen patients evolved to the end stage renal disease after an average time of 29.8 ± 46 months. The average follow-up of the patients was 4,4 years. By comparing the 32 patients presenting a SPA and renal disease to 88 with SPA and without nephropathy, we detected the predictive factors of occurred of nephropathy: tobacco, intense inflammatory syndrome, sacroileite stage 3 or 4 and presence of column bamboo. The finding of 75% of the patients presented a renal failure at the time of the diagnosis of renal involvement suggests that evidence of renal abnormality involvement should be actively sought in this disease.

  7. Abnormal band of lateral meniscus.

    PubMed

    Giordano, Brian; Goldblatt, John

    2009-01-01

    This article describes a case of an "abnormal band" of the lateral meniscus, extending from the posterior horn of the true lateral meniscus to its antero-mid portion, observed during arthroscopy in a 45-year-old white man of Bosnian descent. The periphery of the aberrant lateral meniscus was freely mobile, and not connected to the underlying true lateral meniscus. Preoperative physical examination findings were consistent with medial-sided meniscal pathology only; however, evidence of an anomalous lateral meniscus was seen with magnetic resonance imaging. This anatomical pattern is rare and has been reported in the literature only once, in a report of 2 Asian patients. This article illustrates an anatomical variant of the lateral meniscus in a non-Asian patient with a clinical presentation that has not been previously described. In addition to the case report, the article presents a comprehensive review of the existing body of literature on anomalous lateral meniscus patterns. We believe that the definitions of the types of aberrant meniscus can be clarified to establish improved accuracy in reporting.

  8. [Relationship between abnormal swallowing and mouth breathing].

    PubMed

    Wang, Meng-wu; Li, Hong-fa; Wang, Qiu-rui; Xu, Hao; He, Jing-nan

    2013-12-01

    To investigate the relationship between abnormal swallowing and mouth breathing. Thirty-eight patients with abnormal swallowing and 38 patients with normal swallowing were selected. All patients presented with no airway constriction. The age range of the patients was 11-14 years old. The number of patients with mouth breathing was calculated. Statistical analysis (χ(2) test) was performed. The number of patients with mouth breathing in the abnormal swallowing group (17, 45%) was significantly higher than that in the normal swallowing group (5, 13%) (χ(2) = 9.212, P = 0.002). Abnormal swallowing was related to mouth breathing.

  9. Radiologic atlas of pulmonary abnormalities in children

    SciTech Connect

    Singleton, E.B.; Wagner, M.L.; Dutton, R.V.

    1988-01-01

    This book is an atlas about thoracic abnormalities in infants and children. The authors include computed tomographic, digital subtraction angiographic, ultrasonographic, and a few magnetic resonance (MR) images. They recognize and discuss how changes in the medical treatment of premature infants and the management of infection and pediatric tumors have altered some of the appearances and considerations in these diseases. Oriented toward all aspects of pulmonary abnormalities, the book starts with radiographic techniques and then discusses the normal chest, the newborn, infections, tumors, and pulmonary vascular diseases. There is comprehensive treatment of mediastinal abnormalities and a discussion of airway abnormalities.

  10. Stable prenucleation calcium carbonate clusters.

    PubMed

    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.

  11. Calcium concentration dependent collagen mineralization.

    PubMed

    Niu, Xufeng; Fan, Rui; Tian, Feng; Guo, Xiaolin; Li, Ping; Feng, Qingling; Fan, Yubo

    2017-04-01

    Mineralization of collagen fibrils is a regular combination process of organic and mineral components mainly involving calcium, phosphate and collagen. We report the influence of calcium to the self-assembly of collagen by changing the concentration of calcium ion in the process of mineralization. Low concentration of calcium results in the well collagen self-assembly while poor mineral crystallization. Relatively, high concentration of calcium can hinder collagen self-assembly, whereas it is benefited to mineral crystallization. We also reveal that collagen self-assembly happens in advance of the formation of better mineral crystals. These results interpret the mechanism of collagen mineralization further. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Extracellular calcium sensing in rat aortic vascular smooth muscle cells

    SciTech Connect

    Smajilovic, Sanela; Hansen, Jakob Lerche; Christoffersen, Tue E.H.

    2006-10-06

    Extracellular calcium (Ca2+o) can act as a first messenger in many cell types through a G protein-coupled receptor, calcium-sensing receptor (CaR). It is still debated whether the CaR is expressed in vascular smooth muscle cells (VSMCs). Here, we report the expression of CaR mRNA and protein in rat aortic VSMCs and show that Ca2+o stimulates proliferation of the cells. The effects of Ca2+o were attenuated by pre-treatment with MAPK kinase 1 (MEK1) inhibitor, as well as an allosteric modulator, NPS 2390. Furthermore, stimulation of the VSMCs with Ca2+o-induced phosphorylation of ERK1/2, but surprisingly did not cause inositol phosphate accumulation. We were not able to conclusively state that the CaR mediates Ca2+o-induced cell proliferation. Rather, an additional calcium-sensing mechanism may exist. Our findings may be of importance with regard to atherosclerosis, an inflammatory disease characterized by abnormal proliferation of VSMCs and high local levels of calcium.

  13. The bioavailability of calcium in spinach and calcium-oxalate to calcium-deficient rats.

    PubMed

    Kikunaga, S; Arimori, M; Takahashi, M

    1988-04-01

    We estimated the utilization of calcium in spinach and calcium-oxalate to calcium-deficient rats, and the effect of oxalic acid on absorption of dietary calcium by using calcium-deficient rats. The body weight gain of the calcium-deficient rats for 8 days receiving a calcium-deficient diet supplemented with raw-powdered spinach (R-sp), boiled-powdered spinach (B-sp), or calcium-oxalate (Ca-ox), and a control diet supplemented with oxalic acid (OX-C) were 4.8, 2.8, 4.9, and 5.1 g, respectively. The calcium content in the liver and kidney of the rats receiving R-sp, B-sp, Ca-ox, and OX-C diets significantly increased as compared with the calcium-deficient rats. Significant differences in the liver calcium levels were not observed among the rats receiving various additional diets, though the content in the kidneys of the rats receiving R-sp, B-sp, Ca-ox, and OX-C diets were 28.0, 21.5, 0.11, and 0.59 mg, respectively. An especially large amount of calcium was accumulated in the kidneys of the rats receiving R-sp and B-sp diets. The calcium concentration in the serum of the rats receiving Ca-ox and OX-C diets was higher than the calcium concentration in the serum of the R-sp, B-sp, and calcium-deficient rats. The calcium content in the left tibiae of the rats receiving Ca-ox and OX-C diets was higher than that of the rats receiving R-sp and B-sp diets. The breaking force of the right tibiae of the rats was highest in the OX-C group, and higher in the R-sp and Ca-ox groups than the breaking force of the right tibiae of the rats fed on B-sp diet. The alkaline phosphatase activity in the small intestines of the rats rose in the order of the R-sp, B-sp, and Ca-ox groups, although significant differences of the activity were not observed between the Ca-ox and the OX-C groups. The calcium retention of the rats receiving the calcium-deficient, R-sp, B-sp, Ca-ox, and OX-C diets was -18.5, 35.2, 25.6, 41.6, and 45.8%, respectively. About 35% of the calcium in the spinach was

  14. Uric acid disorders in patients with calcium stones.

    PubMed

    Hodgkinson, A

    1976-02-01

    Plasma and uric acid levels were measured in 132 men with calcium-containing renal stones and in 24 healthy men of similar ages. Fasting resulted in a significant fall in the mean plasma uric acid level of normal subjects. Intermittent hyperuricaemia was observed in 7% of fasting patients. Intermittent hyperuricosuria was found in 17% of non-fasting patients but in only 2 to 6% of fasting subjects. Most of the uric acid abnormalities in patients with calcium stones therefore appear to be due to diet and may be prevented by reducing the consumption of purine-rich foods. A direct relationship was observed between uric acid excretion and urine flow at normal flow rates. It is suggested that the apparent increase in stone incidence, which occurs with rising living standards, may be due partly to increased consumption of purine-rich foods.

  15. Seawater calcium isotopic ratios across the Eocene-Oligocene Transition

    NASA Astrophysics Data System (ADS)

    Griffith, E. M.; Paytan, A.

    2009-12-01

    We reconstructed the evolution of the seawater calcium (Ca) isotopic ratio from marine (pelagic) barite and bulk calcium carbonate over the Eocene-Oligocene Transition (EOT), a period of extreme and rapid change in the global calcite compensation depth (CCD) (Lyle et al., 2008). The CCD is controlled by the balance between calcium carbonate deposition and dissolution in deep sea sediments. Large fluctuations in the CCD may cause changes in the concentration of dissolved Ca in seawater and its isotopic composition if accompanied by imbalances in marine Ca sources and sinks (De La Rocha and DePaolo, 2000). Our results show that the permanent deepening of the CCD during the EOT, which coincided with the major Cenozoic glaciation around 34 million years ago (Zachos et al., 2001), was not accompanied by a significant long-term change in the isotopic ratio of Ca in seawater or its sink (calcium carbonate). A simple isotopic mass balance model is constructed to compare predicted and observed isotopic fluctuations. References: Lyle, M. et al. Pacific Ocean and Cenozoic evolution of climate. Rev. Geophys. 46, 1-47 (2008). De La Rocha, C. L. & DePaolo, D. J. Isotopic evidence for variations in the marine calcium cycle over the Cenozoic. Science 289, 1176-1178 (2000). Zachos, J., Pagani, M., Sloan, L., Thomas, E. & Billups, K. Trends, rhythms, and aberrations in global climate 65 ma to present. Science 292, 686-693 (2001).

  16. The Mechanical Environment Modulates Intracellular Calcium Oscillation Activities of Myofibroblasts

    PubMed Central

    Godbout, Charles; Follonier Castella, Lysianne; Smith, Eric A.; Talele, Nilesh; Chow, Melissa L.; Garonna, Adriano; Hinz, Boris

    2013-01-01

    Myofibroblast contraction is fundamental in the excessive tissue remodeling that is characteristic of fibrotic tissue contractures. Tissue remodeling during development of fibrosis leads to gradually increasing stiffness of the extracellular matrix. We propose that this increased stiffness positively feeds back on the contractile activities of myofibroblasts. We have previously shown that cycles of contraction directly correlate with periodic intracellular calcium oscillations in cultured myofibroblasts. We analyze cytosolic calcium dynamics using fluorescent calcium indicators to evaluate the possible impact of mechanical stress on myofibroblast contractile activity. To modulate extracellular mechanics, we seeded primary rat subcutaneous myofibroblasts on silicone substrates and into collagen gels of different elastic modulus. We modulated cell stress by cell growth on differently adhesive culture substrates, by restricting cell spreading area on micro-printed adhesive islands, and depolymerizing actin with Cytochalasin D. In general, calcium oscillation frequencies in myofibroblasts increased with increasing mechanical challenge. These results provide new insight on how changing mechanical conditions for myofibroblasts are encoded in calcium oscillations and possibly explain how reparative cells adapt their contractile behavior to the stresses occurring in normal and pathological tissue repair. PMID:23691248

  17. Calcium in Plants

    PubMed Central

    WHITE, PHILIP J.; BROADLEY, MARTIN R.

    2003-01-01

    Calcium is an essential plant nutrient. It is required for various structural roles in the cell wall and membranes, it is a counter‐cation for inorganic and organic anions in the vacuole, and the cytosolic Ca2+ concentration ([Ca2+]cyt) is an obligate intracellular messenger coordinating responses to numerous developmental cues and environmental challenges. This article provides an overview of the nutritional requirements of different plants for Ca, and how this impacts on natural flora and the Ca content of crops. It also reviews recent work on (a) the mechanisms of Ca2+ transport across cellular membranes, (b) understanding the origins and specificity of [Ca2+]cyt signals and (c) characterizing the cellular [Ca2+]cyt‐sensors (such as calmodulin, calcineurin B‐like proteins and calcium‐dependent protein kinases) that allow plant cells to respond appropriately to [Ca2+]cyt signals. PMID:12933363

  18. Deficits in the Mitochondrial Enzyme α-Ketoglutarate Dehydrogenase Lead to Alzheimer’s Disease-like Calcium Dysregulation

    PubMed Central

    Gibson, Gary E.; Chen, Huan-Lian; Xu, Hui; Qiu, Linghua; Xu, Zuoshang; Denton, Travis T.; Shi, Qingli

    2011-01-01

    Understanding the molecular sequence of events that culminate in multiple abnormalities in brains from patients that died with Alzheimer’s Disease (AD) will help to reveal the mechanisms of the disease and identify upstream events as therapeutic targets. The activity of the mitochondrial α-ketoglutarate dehydrogenase complex (KGDHC) in homogenates from autopsy brain declines with AD. Experimental reductions in KGDHC in mouse models of AD promote plaque and tangle formation, the hallmark pathologies of AD. We hypothesize that deficits in KGDHC also lead to the abnormalities in endoplasmic reticulum (ER) calcium stores and cytosolic calcium following K+ -depolarization that occur in cells from AD patients and transgenic models of AD. The activity of the mitochondrial enzyme KGDHC was diminished acutely (minutes), long term (days) or chronically (weeks). Acute inhibition of KGDHC produced effects on calcium opposite to those in AD, while the chronic or long term inhibition of KGDHC mimicked the AD-related changes in calcium. Divergent changes in proteins released from the mitochondria that effect ER calcium channels may underlie the selective cellular consequences of acute versus longer term inhibition of KGDHC. The results suggest that the mitochondrial abnormalities in AD can be upstream of those in calcium. PMID:22169199

  19. Inhibition of NAPDH Oxidase 2 (NOX2) Prevents Oxidative Stress and Mitochondrial Abnormalities Caused by Saturated Fat in Cardiomyocytes.

    PubMed

    Joseph, Leroy C; Barca, Emanuele; Subramanyam, Prakash; Komrowski, Michael; Pajvani, Utpal; Colecraft, Henry M; Hirano, Michio; Morrow, John P

    2016-01-01

    Obesity and high saturated fat intake increase the risk of heart failure and arrhythmias. The molecular mechanisms are poorly understood. We hypothesized that physiologic levels of saturated fat could increase mitochondrial reactive oxygen species (ROS) in cardiomyocytes, leading to abnormalities of calcium homeostasis and mitochondrial function. We investigated the effect of saturated fat on mitochondrial function and calcium homeostasis in isolated ventricular myocytes. The saturated fatty acid palmitate causes a decrease in mitochondrial respiration in cardiomyocytes. Palmitate, but not the monounsaturated fatty acid oleate, causes an increase in both total cellular ROS and mitochondrial ROS. Palmitate depolarizes the mitochondrial inner membrane and causes mitochondrial calcium overload by increasing sarcoplasmic reticulum calcium leak. Inhibitors of PKC or NOX2 prevent mitochondrial dysfunction and the increase in ROS, demonstrating that PKC-NOX2 activation is also required for amplification of palmitate induced-ROS. Cardiomyocytes from mice with genetic deletion of NOX2 do not have palmitate-induced ROS or mitochondrial dysfunction. We conclude that palmitate induces mitochondrial ROS that is amplified by NOX2, causing greater mitochondrial ROS generation and partial depolarization of the mitochondrial inner membrane. The abnormal sarcoplasmic reticulum calcium leak caused by palmitate could promote arrhythmia and heart failure. NOX2 inhibition is a potential therapy for heart disease caused by diabetes or obesity.

  20. Altered fetal growth, placental abnormalities, and stillbirth.

    PubMed

    Bukowski, Radek; Hansen, Nellie I; Pinar, Halit; Willinger, Marian; Reddy, Uma M; Parker, Corette B; Silver, Robert M; Dudley, Donald J; Stoll, Barbara J; Saade, George R; Koch, Matthew A; Hogue, Carol; Varner, Michael W; Conway, Deborah L; Coustan, Donald; Goldenberg, Robert L

    2017-01-01

    Worldwide, stillbirth is one of the leading causes of death. Altered fetal growth and placental abnormalities are the strongest and most prevalent known risk factors for stillbirth. The aim of this study was to identify patterns of association between placental abnormalities, fetal growth, and stillbirth. Population-based case-control study of all stillbirths and a representative sample of live births in 59 hospitals in 5 geographic areas in the U.S. Fetal growth abnormalities were categorized as small (<10th percentile) and large (>90th percentile) for gestational age at death (stillbirth) or delivery (live birth) using a published algorithm. Placental examination by perinatal pathologists was performed using a standardized protocol. Data were weighted to account for the sampling design. Among 319 singleton stillbirths and 1119 singleton live births at ≥24 weeks at death or delivery respectively, 25 placental findings were investigated. Fifteen findings were significantly associated with stillbirth. Ten of the 15 were also associated with fetal growth abnormalities (single umbilical artery; velamentous insertion; terminal villous immaturity; retroplacental hematoma; parenchymal infarction; intraparenchymal thrombus; avascular villi; placental edema; placental weight; ratio birth weight/placental weight) while 5 of the 15 associated with stillbirth were not associated with fetal growth abnormalities (acute chorioamnionitis of placental membranes; acute chorioamionitis of chorionic plate; chorionic plate vascular degenerative changes; perivillous, intervillous fibrin, fibrinoid deposition; fetal vascular thrombi in the chorionic plate). Five patterns were observed: placental findings associated with (1) stillbirth but not fetal growth abnormalities; (2) fetal growth abnormalities in stillbirths only; (3) fetal growth abnormalities in live births only; (4) fetal growth abnormalities in stillbirths and live births in a similar manner; (5) a different pattern of

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

    SciTech Connect

    Bizzozero, Julien Scrivener, Karen L.

    2015-10-15

    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 and monocarboaluminate. Increasing the ratio between sulfate and aluminate decreases the extent of limestone reaction.

  2. Calcium-based multi-element chemistry for grid-scale electrochemical energy storage

    PubMed Central

    Ouchi, Takanari; Kim, Hojong; Spatocco, Brian L.; Sadoway, Donald R.

    2016-01-01

    Calcium is an attractive material for the negative electrode in a rechargeable battery due to its low electronegativity (high cell voltage), double valence, earth abundance and low cost; however, the use of calcium has historically eluded researchers due to its high melting temperature, high reactivity and unfavorably high solubility in molten salts. Here we demonstrate a long-cycle-life calcium-metal-based rechargeable battery for grid-scale energy storage. By deploying a multi-cation binary electrolyte in concert with an alloyed negative electrode, calcium solubility in the electrolyte is suppressed and operating temperature is reduced. These chemical mitigation strategies also engage another element in energy storage reactions resulting in a multi-element battery. These initial results demonstrate how the synergistic effects of deploying multiple chemical mitigation strategies coupled with the relaxation of the requirement of a single itinerant ion can unlock calcium-based chemistries and produce a battery with enhanced performance. PMID:27001915

  3. Calcium-based multi-element chemistry for grid-scale electrochemical energy storage

    NASA Astrophysics Data System (ADS)

    Ouchi, Takanari; Kim, Hojong; Spatocco, Brian L.; Sadoway, Donald R.

    2016-03-01

    Calcium is an attractive material for the negative electrode in a rechargeable battery due to its low electronegativity (high cell voltage), double valence, earth abundance and low cost; however, the use of calcium has historically eluded researchers due to its high melting temperature, high reactivity and unfavorably high solubility in molten salts. Here we demonstrate a long-cycle-life calcium-metal-based rechargeable battery for grid-scale energy storage. By deploying a multi-cation binary electrolyte in concert with an alloyed negative electrode, calcium solubility in the electrolyte is suppressed and operating temperature is reduced. These chemical mitigation strategies also engage another element in energy storage reactions resulting in a multi-element battery. These initial results demonstrate how the synergistic effects of deploying multiple chemical mitigation strategies coupled with the relaxation of the requirement of a single itinerant ion can unlock calcium-based chemistries and produce a battery with enhanced performance.

  4. Calcium oscillations index the extent of calcium loading and predict functional recovery during reperfusion in rat myocardium.

    PubMed Central

    Weiss, R G; Gerstenblith, G; Lakatta, E G

    1990-01-01

    Delayed recovery of contractile function after myocardial ischemia may be due to prolonged recovery of high-energy phosphates, persistent acidosis, increased inorganic phosphate, and/or calcium loading. To examine these potential mechanisms, metabolic parameters measured by 31P nuclear magnetic resonance spectroscopy, and spontaneous diastolic myofilament motion caused by sarcoplasmic reticulum-myofilament calcium cycling indexed by the scattered light intensity fluctuations (SLIF) it produces in laser beam reflected from the heart, were studied in isolated atrioventricularly blocked rat hearts (n = 10) after 65 min of ischemia at 30 degrees C. All metabolic parameters recovered to their full extent 5 min after reperfusion. Developed pressure evidenced a small recovery but then fell abruptly. This was accompanied by an increase in end diastolic pressure to 37 +/- 5 mm Hg and a fourfold increase in SLIF, to 252 +/- 58% of baseline. In another series of hearts initial reperfusion with calcium of 0.08 mM prevented the SLIF rise and resulted in improved developed pressure (74 +/- 3% vs. 39 +/- 13% of control), and lower cell calcium (5.9 +/- 3 vs. 10.3 +/- 1.4 mumol/g dry wt). Thus, during reperfusion, delayed contractile recovery is not associated with delayed recovery of pH, inorganic phosphate, or high-energy phosphates and can be attributed, in part, to an adverse effect of calcium loading which can be indexed by increased SLIF occurring at that time. PMID:2312726

  5. [CHROMOSOMAL ABNORMALITIES IN PATIENTS WITH INFERTILITY].

    PubMed

    Pylyp, L Y; Spinenko, L O; Verhoglyad, N V; Kashevarova, O O; Zukin, V D

    2015-01-01

    To assess the frequency and structure of chromosomal abnormalities in patients with infertility, a retrospective analysis of cytogenetic studies of 3414 patients (1741 females and 1673 males), referred to the Clinic of reproductive medicine "Nadiya" from 2007 to 2012, was performed. Chromosomal abnormalities were detected in 2.37% patients: 2.79% in males and 1.95% in females. Balanced structural chromosomal abnormalities prevailed over numerical abnormalities and corresponded to 80.2% of all chromosomal abnormalities detected in the studied group. Sex chromosome abnormalities made up 23.5% of chromosomal pathology (19/81) and included gonosomal aneuploidies in 84% of cases (16/19) and structural abnormalities of chromosome Y in 16% of cases (3/19). The low level sex chromosome mosaicism was detected with the frequency of 0.55%. Our results highlight the importance of cytogenetic studies in patients seeking infertility treatment by assisted reproductive technologies, since an abnormal finding not only provide a firm diagnosis to couples with infertility, but also influences significantly the approach to infertility treatment in such patients.

  6. Immune Abnormalities in Patients with Autism.

    ERIC Educational Resources Information Center

    Warren, Reed P.; And Others

    1986-01-01

    A study of 31 autistic patients (3-28 years old) has revealed several immune-system abnormalities, including decreased numbers of T lymphocytes and an altered ratio of helper-to-suppressor T cells. Immune-system abnormalities may be directly related to underlying biologic processes of autism or an indirect reflection of the actual pathologic…

  7. An Abnormal Psychology Community Based Interview Assignment

    ERIC Educational Resources Information Center

    White, Geoffry D.

    1977-01-01

    A course option in abnormal psychology involves students in interviewing and observing the activities of individuals in the off-campus community who are concerned with some aspect of abnormal psychology. The technique generates student interest in the field when they interview people about topics such as drug abuse, transsexualism, and abuse of…

  8. Prenatal Diagnosis and Evaluation of Abnormal Placentation.

    PubMed

    Fox, Karin A; Lee, Wesley

    2017-09-01

    Abnormalities in placental location or adherence can have important consequences on pregnancy outcome for both mother and fetus. Accurate antenatal detection is crucial for delivery timing and planning to help reduce perinatal risks for adverse events. We review the relevant literature and present a practical approach for the prenatal detection of abnormal placentation.

  9. Screening Sexually Active Teenagers for Cervical Abnormalities

    PubMed Central

    Erdstein, Julius; Pavilanis, Alan V.

    1991-01-01

    Sexually active teenagers are at increased risk of developing cervical abnormalities. It is therefore important to screen them with an annual Pap smear. The techniques of this test are reviewed, as are the importance of sexually transmitted diseases in the development of cytologic abnormalities, the pathophysiology of virus-induced changes, and the terminology of reporting. PMID:21229023

  10. Nail abnormalities in patients with vitiligo.

    PubMed

    Topal, Ilteris Oguz; Gungor, Sule; Kocaturk, Ozgur Emek; Duman, Hatice; Durmuscan, Mustafa

    2016-01-01

    Vitiligo is an acquired pigmentary skin disorder affecting 0.1-4% of the general population. The nails may be affected in patients with an autoimmune disease such as psoriasis, and in those with alopecia areata. It has been suggested that nail abnormalities should be apparent in vitiligo patients. We sought to document the frequency and clinical presentation of nail abnormalities in vitiligo patients compared to healthy volunteers. We also examined the correlations between nail abnormalities and various clinical parameters. This study included 100 vitiligo patients and 100 healthy subjects. Full medical histories were collected from the subjects, who underwent thorough general and nail examinations. All nail changes were noted. In the event of clinical suspicion of a fungal infection, additional mycological investigations were performed. Nail abnormalities were more prevalent in the patients (78%) than in the controls (55%) (p=0.001). Longitudinal ridging was the most common finding (42%), followed by (in descending order): leukonychia, an absent lunula, onycholysis, nail bed pallor, onychomycosis, splinter hemorrhage and nail plate thinning. The frequency of longitudinal ridging was significantly higher in patients than in controls (p<0.001). Nail abnormalities were more prevalent in vitiligo patients than in controls. Systematic examination of the nails in such patients is useful because nail abnormalities are frequent. However, the causes of such abnormalities require further study. Longitudinal ridging and leukonychia were the most common abnormalities observed in this study.

  11. Immune Abnormalities in Patients with Autism.

    ERIC Educational Resources Information Center

    Warren, Reed P.; And Others

    1986-01-01

    A study of 31 autistic patients (3-28 years old) has revealed several immune-system abnormalities, including decreased numbers of T lymphocytes and an altered ratio of helper-to-suppressor T cells. Immune-system abnormalities may be directly related to underlying biologic processes of autism or an indirect reflection of the actual pathologic…

  12. An Abnormal Psychology Community Based Interview Assignment

    ERIC Educational Resources Information Center

    White, Geoffry D.

    1977-01-01

    A course option in abnormal psychology involves students in interviewing and observing the activities of individuals in the off-campus community who are concerned with some aspect of abnormal psychology. The technique generates student interest in the field when they interview people about topics such as drug abuse, transsexualism, and abuse of…

  13. Nail abnormalities in patients with vitiligo*

    PubMed Central

    Topal, Ilteris Oguz; Gungor, Sule; Kocaturk, Ozgur Emek; Duman, Hatice; Durmuscan, Mustafa

    2016-01-01

    Background Vitiligo is an acquired pigmentary skin disorder affecting 0.1-4% of the general population. The nails may be affected in patients with an autoimmune disease such as psoriasis, and in those with alopecia areata. It has been suggested that nail abnormalities should be apparent in vitiligo patients. Objective We sought to document the frequency and clinical presentation of nail abnormalities in vitiligo patients compared to healthy volunteers. We also examined the correlations between nail abnormalities and various clinical parameters. Methods This study included 100 vitiligo patients and 100 healthy subjects. Full medical histories were collected from the subjects, who underwent thorough general and nail examinations. All nail changes were noted. In the event of clinical suspicion of a fungal infection, additional mycological investigations were performed. Results Nail abnormalities were more prevalent in the patients (78%) than in the controls (55%) (p=0.001). Longitudinal ridging was the most common finding (42%), followed by (in descending order): leukonychia, an absent lunula, onycholysis, nail bed pallor, onychomycosis, splinter hemorrhage and nail plate thinning. The frequency of longitudinal ridging was significantly higher in patients than in controls (p<0.001). Conclusions Nail abnormalities were more prevalent in vitiligo patients than in controls. Systematic examination of the nails in such patients is useful because nail abnormalities are frequent. However, the causes of such abnormalities require further study. Longitudinal ridging and leukonychia were the most common abnormalities observed in this study. PMID:27579738

  14. Defoaming effect of calcium soap.

    PubMed

    Zhang, Hui; Miller, Clarence A; Garrett, Peter R; Raney, Kirk H

    2004-11-15

    The effect of calcium oleate on foam stability was studied for aqueous solutions of two commonly used surfactants (anionic and nonionic) under alkaline conditions in the absence of oil. For the anionic surfactant, defoaming by calcium oleate appears to involve two mechanisms. One is that oleate and calcium ions are presumably incorporated into the surfactant monolayers with a resulting decrease in the maximum of the disjoining pressure curve and therefore produces less stable thin films. The other is bridging of the films by calcium oleate particles. The latter mechanism was especially important in freshly made solutions where precipitation in the aqueous phase was still occurring when the foam was generated. Foams generated after aging (hours) when precipitation was nearly complete were more stable even though solution turbidities were greater. Foams of the nonionic surfactant were less stable than those of the anionic surfactant but were also destabilized by sufficient amounts of calcium oleate and exhibited a similar aging effect. A simplified model was developed for estimating the sodium oleate concentration at which precipitation commences in solutions of the anionic surfactant containing dissolved calcium. It includes enhancement of calcium content in the electrical double layers of the surfactant micelles. Predictions of the model were in agreement with experiment.

  15. Can transcutaneous recordings detect gastric electrical abnormalities?

    PubMed Central

    Familoni, B O; Bowes, K L; Kingma, Y J; Cote, K R

    1991-01-01

    The ability of transcutaneous recordings of gastric electrical activity to detect gastric electrical abnormalities was determined by simultaneous measurements of gastric electrical activity with surgically implanted serosal electrodes and cutaneous electrodes in six patients undergoing abdominal operations. Transient abnormalities in gastric electrical activity were seen in five of the six patients during the postoperative period. Recognition of normal gastric electrical activity by visual analysis was possible 67% of the time and with computer analysis 95% of the time. Ninety four per cent of abnormalities in frequency were detected by visual analysis and 93.7% by computer analysis. Abnormalities involving a loss of coupling, however, were not recognised by transcutaneous recordings. Transcutaneous recordings of gastric electrical activity assessed by computer analysis can usually recognise normal gastric electrical activity and tachygastria. Current techniques, however, are unable to detect abnormalities in electrical coupling. PMID:1864531

  16. Core-Shell Collagen Peptide Chelated Calcium/Calcium Alginate Nanoparticles from Fish Scales for Calcium Supplementation.

    PubMed

    Guo, Honghui; Hong, Zhuan; Yi, Ruizao

    2015-07-01

    We report simple methods for preparing collagen peptide chelated calcium (cpcc) and a novel cpcc-loaded nanoparticle from marine fish scales for calcium supplementation. Cpcc nanoparticles have an average diameter of approximately 150 nm and a calcium content of up to 130.4 g/kg. Calcium alginate was selected to encapsulate cpcc for the preparation of core-shell cpcc/calcium alginate nanoparticles. The core-shell nanoparticles were mainly 200 to 500 nm in diameter. The ratio of calcium to sulfur was approximately 1.6:1. In vivo experiments indicated both cpcc and core-shell cpcc were able to improve calcium absorption and prevent calcium deficiency. Especially core-shell cpcc worked well to increase femur bone mineral density and femur calcium content in rats significantly. The study demonstrated that cpcc and core-shell cpcc nanoparticles were ideal for calcium supplementation. Calcium deficiency has become an increasingly relevant health concern in the food industry. There is an urgent need for new effective calcium supplements. This study consisted of preparing and characterizing alginate nanoparticles loaded with collagen peptide chelated calcium. These nanoparticles can enhance calcium absorption significantly and prevent calcium deficiency. The data presented in this study can aid the food industry in developing a new ideal calcium supplement. © 2015 Institute of Food Technologists®

  17. Liver abnormalities and endocrine diseases.

    PubMed

    Burra, Patrizia

    2013-08-01

    The liver and its pleotropic functions play a fundamental role in regulating metabolism, and is also an inevitable target of multiple metabolic disorders. The numerous and constant relationships and feedback mechanisms between the liver and all endocrine organs is reflected by the fact that an alteration of one oftentimes results in the malfunction of the other. Hypo- and hyperthyroidism are frequently associated with hepatic alterations, and thyroid diseases must be excluded in transaminase elevation of unknown cause. Drugs such as propylthiouracil, used in the treatment of hyperthyroidism, may induce liver damage, and other drugs such as amiodarone, carbamazepine, and several chemotherapeutic agents can lead to both thyroid and liver abnormalities. Liver diseases such as hepatitis, hepatocellular carcinoma, and cirrhosis may cause altered levels of thyroid hormones, and alcoholic liver disease, both due to the noxious substance ethanol as well as to the hepatic damage it causes, may be responsible for altered thyroid function. Both excess and insufficiency of adrenal function may result in altered liver function, and adrenocortical dysfunction may be present in patients with cirrhosis, especially during episodes of decompensation. Again an important player which affects both the endocrine system and the liver, alcohol may be associated with pseudo-Cushing syndrome. Sex hormones, both intrinsic as well as extrinsically administered, have an important impact on liver function. While oestrogens are related to cholestatic liver damage, androgens are the culprit of adenomas and hepatocellular carcinoma, among others. Chronic liver disease, on the other hand, has profound repercussions on sex hormone metabolism, inducing feminization in men and infertility and amenorrhoea in women. Lastly, metabolic syndrome, the pandemia of the present and future centuries, links the spectrum of liver damage ranging from steatosis to cirrhosis, to the array of endocrine alterations

  18. FDG-PET evaluation of pleural abnormalities

    SciTech Connect

    Lowe, V.J.; Patz, E.; Harris, P.L.

    1994-05-01

    Pleural abnormalities identified on anatomical studies are often nonspecific and may represent benign or malignant disease. We prospectively evaluated the ability of FDG-PET to identify malignancy in patients with pleural abnormalities detected on chest radiographs or chest CT. Thirty-two patients with pleural abnormalities (pleural masses, thickening or effusions) found on chest radiographs or CT were evaluated by FDG-PET. Regions of interest (ROI) were identified on the PET images correlating to anatomic abnormalities and standard uptake ratios (SUR`s) of these ROI`s were calculated. A SUR value of 2.5 or greater was considered positive for malignancy. Physicians blinded to biopsy results graded their confidence of malignancy (1-5 scale) and graded lesion FDG uptake with respect to mediastinal radioactivity. Twenty-three of the patients had definitive diagnoses by tissue biopsy. Seventeen of these patients had malignant (SUR=7.9{plus_minus}3.8) and 6 had benign (SUR=2.8{plus_minus}2.4) causes of their pleural abnormalities (p=0.001). All but two malignant cases had SURs higher than 2.5 and one of these two was correctly interpreted by the observers. SURs lower than 2.5 were seen in four of the six (67%) benign pleural abnormalities. Using a combination of both visual and semiquantitative analysis, the sensitivity of FDG-PET for detecting malignant pleural abnormalities was 94%. Active infections in the pleural space had increased FDG uptake on PET studies while other benign pleural abnormalities did not. FDG-PET has very high sensitivity for detecting malignant pleural abnormalities and can differentiate benign from malignant pleural abnormalities.

  19. Controlled environment life support system: Calcium-related leaf injuries on plants

    NASA Technical Reports Server (NTRS)

    Tibbitts, T. W.

    1986-01-01

    Calcium related injuries to plants grown in controlled environments under conditions which maximize plant growth rates are described. Procedures to encourage movement of calcium into developing leaves of lettuce plants were investigated. The time course and pattern of calcium accumulation was determined to develop effective control procedures for this injury, termed tipburn. Procedures investigated were: (1) increasing the relative humidity to saturation during the dark period and altering root temperatures, (2) maximizing water stress during light and minimizing water stress during dark periods, (3) shortening the light-dark cycle lengths in combination with elevated moisture levels during the dark cycles, (4) reducing nutrient concentrations and (5) vibrating the plants. Saturated humidities at night increased the rate of growth and the large fluctuation in plant water potential encouraged calcium movement to the young leaves and delayed tipburn. Root temperature regulation between 15 and 26 C was not effective in preventing tipburn. Attempts to modulate water stress produced little variation, but no difference in tipburn development. Variations in light-dark cycle lengths also had no effect on calcium concentrations within developing leaves and no variation in tipburn development. Low concentrations of nutrient solution delayed tipburn, presumably because of greater calcium transport in the low concentration plants. Shaking of the plants did not prevent tipburn, but did delay it slightly.

  20. Calcium signals in olfactory neurons.

    PubMed

    Tareilus, E; Noé, J; Breer, H

    1995-11-09

    Laser scanning confocal microscopy in combination with the fluorescent calcium indicators Fluo-3 and Fura-Red was employed to estimate the intracellular concentration of free calcium ions in individual olfactory receptor neurons and to monitor temporal and spatial changes in the Ca(2+)-level upon stimulation. The chemosensory cells responded to odorants with a significant increase in the calcium concentration, preferentially in the dendritic knob. Applying various stimulation paradigma, it was found that in a population of isolated cells, subsets of receptor neurons display distinct patterns of responsiveness.