Sample records for calcium reflect normal

  1. Normal and Malignant Cells Exhibit Differential Responses to Calcium Electroporation. (United States)

    Frandsen, Stine K; Krüger, Mie B; Mangalanathan, Uma M; Tramm, Trine; Mahmood, Faisal; Novak, Ivana; Gehl, Julie


    Calcium electroporation may offer a simple general tool for anticancer therapy. Transient permeabilization of cancer cell membranes created by applying short, high-voltage pulses in tumors enables high calcium influxes that trigger cell death. In this study, we compared the relative sensitivity of different human tumor models and normal tissues to calcium electroporation. Plasma membrane Ca(2+)-ATPase (PMCA) protein expression was confirmed in vitro in all cancer cell lines and normal primary dermal fibroblasts studied. In all tumor types tested in vivo, calcium electroporation effectively induced necrosis, with a range of sensitivities observed (36%-88%) 2 days after treatment. Necrosis was induced using calcium concentrations of 100-500 mmol/L and injection volumes 20%-80% of tumor volume. Notably, only limited effects were seen in normal tissue. Calcium content increased >7-fold in tumor and skin tissue after calcium electroporation but decreased in skin tissue 4 hours after treatment to levels comparable with untreated controls, whereas calcium content endured at high levels in tumor tissue. Mechanistic experiments in vitro indicated that calcium influx was similar in fibroblasts and cancer cells. However, we observed decreased PMCA expression in cancer cells compared with fibroblasts, offering a potential explanation for the different calcium content in tumor cells versus normal tissues. Overall, our results suggest that calcium electroporation can elicit a rapid and selective necrosis of solid tumors, with limited deleterious effects on surrounding normal tissues. Cancer Res; 77(16); 4389-401. ©2017 AACR. ©2017 American Association for Cancer Research.

  2. Normal and malignant cells exhibit differential responses to calcium electroporation

    DEFF Research Database (Denmark)

    Frandsen, Stine Krog; Krüger, Mie Barthold; Mangalanathan, Uma M.


    Calcium electroporation may offer a simple general tool for anticancer therapy. Transient permeabilization of cancer cell membranes created by applying short, high-voltage pulses in tumors enables high calcium influxes that trigger cell death. In this study, we compared the relative sensitivity...... of different human tumor models and normal tissues to calcium electroporation. Plasma membrane Ca(2+)-ATPase (PMCA) protein expression was confirmed in vitro in all cancer cell lines and normal primary dermal fibroblasts studied. In all tumor types tested in vivo, calcium electroporation effectively induced...... tissue after calcium electroporation but decreased in skin tissue 4 hours after treatment to levels comparable with untreated controls, whereas calcium content endured at high levels in tumor tissue. Mechanistic experiments in vitro indicated that calcium influx was similar in fibroblasts and cancer...

  3. Calcium homeostasis after parathyroidectomy in normal and shocked states. (United States)

    McGonigal, M D; Elliott, L; Lucas, C E; Han, S; Grabow, D; Ledgerwood, A M; Thompson, N; Dawe, E J


    The natural history of parathyroidectomy was studied for 75 weeks in two dogs. After parathyroidectomy, the dogs required intravenous and intramuscular calcium supplementation for 1 week. Despite calcium supplementation, in 2 weeks the ionized calcium (Ca++) level fell from 4.67 mg/dl to 2.39 mg/dl. The Ca++ level rose to 4.25 mg/dl by 7 weeks after which the intramuscular calcium supplement was gradually weaned so that no calcium was given after 20 weeks. The Ca++ level stabilized at 3.15 to 3.25 mg/dl after 20 weeks. Postoperative parathormone (PTH) levels remained low. The response to hemorrhagic shock in these two calcium-independent dogs was compared with that seen in two calcium-dependent dogs 4 weeks after parathyroidectomy and to that seen in two euparathyroid dogs. Shock caused a sharp decrease in Ca++ in all animals that had parathyroid ectomy. Prostaglandin E2 (PGE2) was elevated preoperatively in these dogs and fell markedly during shock. Ca++ remained normal and PGE2 increased slightly after shock in the euparathyroid dogs. Cardiac output rose with resuscitation in the euparathyroid dogs but remained constant in the calcium-dependent dogs and increased slightly in the calcium independent parathyroidectomized animals. PTH levels were low in the parathyroidectomy groups and did not react to shock. PTH increased markedly after resuscitation in the euparathyroid dogs, suggesting its role as an acute-phase hormone. All levels returned to baseline levels within 3 days after shock. Adaptation to hypocalcemia occurs in parathyroidectomized dogs and involves PGE2 as well as other factors. Hemorrhagic shock exceeds this compensatory response which in euparathyroid dogs involves active PTH release in response to hypocalcemia.

  4. Observations on the normal reflection of gaseous detonations (United States)

    Damazo, J.; Shepherd, J. E.


    Experimental results are presented examining the behavior of the shock wave created when a gaseous detonation wave normally impinges upon a planar wall. Gaseous detonations are created in a 7.67-m-long, 280-mm-internal-diameter detonation tube instrumented with a test section of rectangular cross section enabling visualization of the region at the tube-end farthest from the point of detonation initiation. Dynamic pressure measurements and high-speed schlieren photography in the region of detonation reflection are used to examine the characteristics of the inbound detonation wave and outbound reflected shock wave. Data from a range of detonable fuel/oxidizer/diluent/initial pressure combinations are presented to examine the effect of cell-size and detonation regularity on detonation reflection. The reflected shock does not bifurcate in any case examined and instead remains nominally planar when interacting with the boundary layer that is created behind the incident wave. The trajectory of the reflected shock wave is examined in detail, and the wave speed is found to rapidly change close to the end-wall, an effect we attribute to the interaction of the reflected shock with the reaction zone behind the incident detonation wave. Far from the end-wall, the reflected shock wave speed is in reasonable agreement with the ideal model of reflection which neglects the presence of a finite-length reaction zone. The net far-field effect of the reaction zone is to displace the reflected shock trajectory from the predictions of the ideal model, explaining the apparent disagreement of the ideal reflection model with experimental reflected shock observations of previous studies.

  5. Crossed Andreev reflection in graphene normal-superconductor-normal structures with pseudo-diffusive interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadpour, Hakimeh, E-mail: [Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, 45195 Zanjan (Iran, Islamic Republic of); Asgari, Asghar, E-mail: [Research Institute for Applied Physics, University of Tabriz, 51665-163, Tabriz (Iran, Islamic Republic of); School of Electrical, Electronics and Computer Engineering, the University of Western Australia, Crawley, WA 6009 (Australia)


    In this Letter graphene normal-superconductor-normal heterostructures are modeled for studying the crossed Andreev reflection. A thin layer of undoped graphene with Fermi energy at the Dirac point at is assumed the interface between superconductor layer and each normal lead. The resulting contribution of the crossed Andreev reflection to the nonlocal conductance equals that of the electron elastic cotunneling. We explain this as another figure of merit for pseudodiffusive conduction at the Dirac point of the undoped layers. Also structures with only one undoped layer at the interface between the superconductor and one of the normal leads, as well as structures in which one of the leads is ferromagnetic, show pseudodiffusive conduction at the Dirac points.

  6. Pursuing Normality: Reflections on Cancer Survivorship Care of Lymphoma Survivors. (United States)

    Madsen, Louise S; Handberg, Charlotte


    The present study explored the reflections on cancer survivorship care of lymphoma survivors in active treatment. Lymphoma survivors have survivorship care needs, yet their participation in cancer survivorship care programs is still reported as low. The aim of this study was to understand the reflections on cancer survivorship care of lymphoma survivors to aid the future planning of cancer survivorship care and overcome barriers to participation. Data were generated in a hematological ward during 4 months of ethnographic fieldwork, including participant observation and 46 semistructured interviews with 9 lymphoma survivors. Interpretive description methodology and social practice theory guided the analytical framework. "Pursuing normality" was an overall finding and was comprised of 2 overarching patterns, "future prospects" and "survivorship care perceptions," both implying an influence on whether to participate in cancer survivorship care programs. Because of "pursuing normality," 8 of 9 participants opted out of cancer survivorship care programming due to prospects of "being cured" and perceptions of cancer survivorship care as "a continuation of the disease." The findings add to our understanding of possible barriers for participation in cancer survivorship care and outline important aspects to account for in the practice of health professionals. The study findings may guide practice to establish a systematic approach for providing information to cancer survivors regarding the possible management of their symptoms and of the content and purpose of cancer survivorship care.

  7. Use of reflectance spectroscopy for early detection of calcium deficiency in plants (United States)

    Li, Bingqing; Wah, Liew Oi; Asundi, Anand K.


    This article investigates calcium deficiency symptoms of the plants grown under hydroponics conditions. Leaf reflectance data were collected from plants, and then transformed to L*, a*, b* values, which provide color information of the leaves. After comparing the color information of deficient plants to control plants, a set of deficiency criterion was established for early detection of calcium deficiency in the plants. Calcium deficiency could be detected as early as two days from the onset of stress in mature plants when optical data were collected from terminal young leaves. Young plants subjected to calcium stress for 9 days could not be distinguished from nutrient sufficient plants.

  8. normal values for ionized calcium in the plasma of normal lactating ...

    African Journals Online (AJOL)

    Department Human and Animal Physiology, University of Ste//enbosch. OPSOMMING: ... single 21-28 day old suckling lambs was 4,47 ±0,65 mg/IOO ml (1,12 ±O,16 mMfI). On average ... most important fraction of total calcium it was decided.

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

    DEFF Research Database (Denmark)

    Bro, S; Brandi, L; Olgaard, K


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

  10. Impact of calcium sulphate and calcium carbide on nitrogen use efficiency of wheat in normal and saline sodic soils

    Directory of Open Access Journals (Sweden)

    I.A. Mahmood


    Full Text Available pot experiment was conducted to study the effect of calcium as CaSO4 or CaC2 (20 mg Ca kg-1 of soil from each source on N use efficiency of wheat (Triticum aestivum L. var. Inqlab-91 under normal (ECe=0.7 dS m-1, SAR=4.37 and pH=8.1 and saline-sodic soils (ECe=8.7 dS m-1, SAR=21.43 and pH=9.2 in glass house at National Agricultural Research Centre, Islamabad during Kharif season 2007-08. The crop was grown to maturity and data on tillering, plant height, panicle length, grains spike-1, straw and grain yields were recorded at the time of crop harvest. A considerable reduction in plant height (38% and grain yield (44% was observed when grown in saline-sodic soil (ECe=8.7 dS m-1 as compared to normal soil (ECe=0.7 dS m-1 while N application significantly improved plant growth and yield in both conditions. Among the treatments, N application even at lower rate supplemented with calcium as CaSO4, CaC2 or their mixture (1:1 showed better performance than that of straight N application in both soils. A 41 to 53% increase in plant growth and 36 to 44% in grain yield over control (without N were observed through N fertilization at 25 and 50 mg kg-1 of soil supplemented with calcium as CaC2 in salinesodic soil. Similarly, calcium as CaSO4 application also caused a considerable improvement in plant growth (34 to 52% and grain yield (25 to 43%. However, the effect of mixture application of CaSO4 and CaC2 (1:1 on plant growth and yield was comparatively more pronounced for both the soils. Interestingly, lower dose ofN (25 mg kg-1 with calcium as CaC2 alone or in combination with CaSO4 (1:1 supplementation showed statistically equal performance to that of higher dose (N=50 mg kg-1 alone. Tissue Na+ significantly decreased while K+ and Ca2+ concentrations were elevated due to N application along with calcium nutrition. Maximum N uptake and apparent N recovery were revealed from treatments where N was applied @ 50 mg kg-1 soil supplemented with calcium as CaC2

  11. OligoG CF-5/20 normalizes cystic fibrosis mucus by chelating calcium. (United States)

    Ermund, Anna; Recktenwald, Christian V; Skjåk-Braek, Gudmund; Meiss, Lauren N; Onsøyen, Edvar; Rye, Philip D; Dessen, Arne; Myrset, Astrid Hilde; Hansson, Gunnar C


    The goal of this study was to determine whether the guluronate (G) rich alginate OligoG CF-5/20 (OligoG) could detach cystic fibrosis (CF) mucus by calcium chelation, which is also required for normal mucin unfolding. Since bicarbonate secretion is impaired in CF, leading to insufficient mucin unfolding and thereby attached mucus, and since bicarbonate has the ability to bind calcium, we hypothesized that the calcium chelating property of OligoG would lead to detachment of CF mucus. Indeed, OligoG could compete with the N-terminus of the MUC2 mucin for calcium binding as shown by microscale thermophoresis. Further, effects on mucus thickness and attachment induced by OligoG and other alginate fractions of different length and composition were evaluated in explants of CF mouse ileum mounted in horizontal Ussing-type chambers. OligoG at 1.5% caused effective detachment of CF mucus and the most potent alginate fraction tested, the poly-G fraction of about 12 residues, had similar potency compared to OligoG whereas mannuronate-rich (M) polymers had minimal effect. In conclusion, OligoG binds calcium with appropriate affinity without any overt harmful effect on the tissue and can be exploited for treating mucus stagnation. © 2017 John Wiley & Sons Australia, Ltd.

  12. Is Hong Kong experiencing normalization of adolescent drug use? Some reflections on the normalization thesis. (United States)

    Cheung, Nicole W T; Cheung, Yuet W


    The upsurge of consumption of party drugs among adolescents in recent years in Hong Kong has been part of the global trend of adolescent recreational use of drugs at rave parties, discos and similar party settings. Scholars in Western societies have recently proposed the thesis of "normalization of adolescent drug use" to describe such a trend. The normalization thesis points at three major aspects of the normalization phenomenon, namely, a rapid increase of the prevalence of drug use in young people, the widespread popularity of recreational drug use that is closely linked with the recent arrival of dance club culture, and a receptive attitude towards drug use as a normal part of leisure. This article aims to examine whether the normalization thesis can be applied to analyze the situation of adolescent drug use in Hong Kong. Data are drawn from official statistics and a recent survey conducted in 2002-2004 of drug use of Hong Kong marginal youths (N = 504). The case of Hong Kong only partially supports the thesis. Our findings show that the normalization of drug use among young people has occurred in Hong Kong, but the extent of normalization is smaller than those in Western societies like the United Kingdom. They also suggest that a recognition of possible cultural differences may be complementary to the normalization thesis. Limitations of the study are also noted.

  13. Calcium Electroporation: Evidence for Differential Effects in Normal and Malignant Cell Lines, Evaluated in a 3D Spheroid Model. (United States)

    Frandsen, Stine Krog; Gibot, Laure; Madi, Moinecha; Gehl, Julie; Rols, Marie-Pierre


    Calcium electroporation describes the use of high voltage electric pulses to introduce supraphysiological calcium concentrations into cells. This promising method is currently in clinical trial as an anti-cancer treatment. One very important issue is the relation between tumor cell kill efficacy-and normal cell sensitivity. Using a 3D spheroid cell culture model we have tested the effect of calcium electroporation and electrochemotherapy using bleomycin on three different human cancer cell lines: a colorectal adenocarcinoma (HT29), a bladder transitional cell carcinoma (SW780), and a breast adenocarcinoma (MDA-MB231), as well as on primary normal human dermal fibroblasts (HDF-n). The results showed a clear reduction in spheroid size in all three cancer cell spheroids three days after treatment with respectively calcium electroporation (pspheroids was neither affected after calcium electroporation nor electrochemotherapy using bleomycin, indicating that calcium electroporation, like electrochemotherapy, will have limited adverse effects on the surrounding normal tissue when treating with calcium electroporation. The intracellular ATP level, which has previously been shown to be depleted after calcium electroporation, was measured in the spheroids after treatment. The results showed a dramatic decrease in the intracellular ATP level (pspheroid types-malignant as well as normal. In conclusion, calcium electroporation seems to be more effective in inducing cell death in cancer cell spheroids than in a normal fibroblast spheroid, even though intracellular ATP level is depleted in all spheroid types after treatment. These results may indicate an important therapeutic window for this therapy; although further studies are needed in vivo and in patients to investigate the effect of calcium electroporation on surrounding normal tissue when treating tumors.

  14. Calcium (United States)

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

  15. Quantification of calcium using localized normalization on laser-induced breakdown spectroscopy data (United States)

    Sabri, Nursalwanie Mohd; Haider, Zuhaib; Tufail, Kashif; Aziz, Safwan; Ali, Jalil; Wahab, Zaidan Abdul; Abbas, Zulkifly


    This paper focuses on localized normalization for improved calibration curves in laser-induced breakdown spectroscopy (LIBS) measurements. The calibration curves have been obtained using five samples consisting of different concentrations of calcium (Ca) in potassium bromide (KBr) matrix. The work has utilized Q-switched Nd:YAG laser installed in LIBS2500plus system with fundamental wavelength and laser energy of 650 mJ. Optimization of gate delay can be obtained from signal-to-background ratio (SBR) of Ca II 315.9 and 317.9 nm. The optimum conditions are determined in which having high spectral intensity and SBR. The highest spectral lines of ionic and emission lines of Ca at gate delay of 0.83 µs. From SBR, the optimized gate delay is at 5.42 µs for both Ca II spectral lines. Calibration curves consist of three parts; original intensity from LIBS experimentation, normalization and localized normalization of the spectral line intensity. The R2 values of the calibration curves plotted using locally normalized intensities of Ca I 610.3, 612.2 and 616.2 nm spectral lines are 0.96329, 0.97042, and 0.96131, respectively. The enhancement from calibration curves using the regression coefficient allows more accurate analysis in LIBS. At the request of all authors of the paper, and with the agreement of the Proceedings Editor, an updated version of this article was published on 24 May 2017.

  16. Normalization of serum calcium by cinacalcet in a patient with hypercalcaemia due to a de novo inactivating mutation of the calcium-sensing receptor.

    NARCIS (Netherlands)

    Timmers, H.J.L.M.; Karperien, M.; Hamdy, N.A.; Boer, H. de; Hermus, A.R.M.M.


    Familial benign hypocalciuric hypercalcaemia (FHH) results from a heterozygous inactivating mutation of the calcium-sensing receptor (CaR) and is characterized by hypercalcaemia, hypocalciuria and inappropriately normal plasma levels of parathyroid hormone. In a minority of patients, a loss of

  17. Protanopic observers show nearly normal color constancy with natural reflectance spectra. (United States)

    Baraas, Rigmor C; Foster, David H; Amano, Kinjiro; Nascimento, Sérgio M C


    The ability of color-deficient observers to discriminate between illuminant changes and surface-reflectance changes in a scene was tested with natural and Munsell reflectance spectra. To avoid the confounding effects of spatial structure, stimuli were simulations of Mondrian-like colored patterns, presented on a computer-controlled color monitor. Protanopes performed less well than normal trichromats, regardless of the type of reflectance spectra, but they were least disadvantaged with patterns comprising reflectance spectra drawn from urban and rural scenes, more characteristic of the natural environment.

  18. Comparison of 25-hydroxyvitamin D and Calcium Levels between Polycystic Ovarian Syndrome and Normal Women

    Directory of Open Access Journals (Sweden)

    Ashraf Moini


    Full Text Available Background: Given the relationship of vitamin D deficiency with insulin resistance syndrome as the component of polycystic ovary syndrome (PCOS, the main aim of this study was to compare serum level of 25- hydroxyvitamin D [25(OHD] between PCOS patients and normal individuals. Materials and Methods: A cross sectional study was conducted to compare 25(OHD level between117 normal and 125 untreated PCOS cases at our clinic in Arash Hospital, Tehran, Iran, during 2011-2012. The obtained levels of 25(OHD were classified as follows: lower than 25 nmol/ml as severe deficiency, between 25-49.9 nmol/ml as deficiency, 50-74.9 nmol/ml as insufficiency, and above 75 nmol/ml asnormal. In addition, endocrine and metabolic variables were evaluated. Results: Among PCOS patients, our findings shows 3(2.4% normal, 7(5.6% with insufficiency, 33(26.4% with deficiency and 82(65.6% with severe deficiency, whereas in normal participants, 5(4.3% normal, 4(3.4% with insufficiency, 28(23.9% with deficiency and 80(68.4% with severe deficiency. Comparison of 25(OHD level between two main groups showed no significant differences (p= 0.65. Also, the calcium and 25(OHD levels had no significant differences in patients with overweight (p=0.22 and insulin resistance (p=0.64. But we also found a relationship between 25(OHD level and metabolic syndrome (p=0.01. Furthermore, there was a correlation between 25(OHD and body mass index (BMI in control group (p=0.01, while the C-reactive protein (CRP level was predominantly higher in PCOS group (p<0.001. Conclusion: Although the difference of 25(OHD level between PCOS and healthy women is not significant, the high prevalence of 25(OHD deficiency is a real alarm for public health care system and may influence our results.

  19. Calcium (United States)

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

  20. Short-term in vivo evaluation of zinc-containing calcium phosphate using a normalized procedure

    Energy Technology Data Exchange (ETDEWEB)

    Calasans-Maia, Monica, E-mail: [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Calasans-Maia, José, E-mail: [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Santos, Silvia, E-mail: [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Mavropoulos, Elena, E-mail: [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Farina, Marcos, E-mail: [Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Lima, Inayá, E-mail: [Nuclear Instrumentation Laboratory, Nuclear Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Lopes, Ricardo Tadeu [Nuclear Instrumentation Laboratory, Nuclear Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Rossi, Alexandre, E-mail: [LABIOMAT, Brazilian Center for Physics Research, CBPF, Rio de Janeiro (Brazil); Granjeiro, José Mauro, E-mail: [Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Niteroi, Rio de Janeiro (Brazil); Bioengineering Division, National Institute of Metrology, Quality and Technology, Duque de Caxias, Rio de Janeiro (Brazil)


    The effect of zinc-substituted calcium phosphate (CaP) on bone osteogenesis was evaluated using an in vivo normalized ISO 10993-6 protocol. Zinc-containing hydroxyapatite (ZnHA) powder with 0.3% by wt zinc (experimental group) and stoichiometric hydroxyapatite (control group) were shaped into cylindrical implants (2 × 6 mm) and were sintered at 1000 °C. Thermal treatment transformed the ZnHA cylinder into a biphasic implant that was composed of Zn-substituted HA and Zn-substituted β-tricalcium phosphate (ZnHA/βZnTCP); the hydroxyapatite cylinder was a highly crystalline and poorly soluble HA implant. In vivo tests were performed in New Zealand White rabbits by implanting two cylinders of ZnHA/βZnTCP in the left tibia and two cylinders of HA in the right tibia for 7, 14 and 28 days. Incorporation of 0.3% by wt zinc into CaP increased the rate of Zn release to the biological medium. Microfluorescence analyses (μXRF-SR) using synchrotron radiation suggested that some of the Zn released from the biomaterial was incorporated into new bone near the implanted region. In contrast with previous studies, histomorphometric analysis did not show significant differences between the newly formed bone around ZnHA/βZnTCP and HA due to the dissolution profile of Zn-doped CaP. Despite the great potential of Zn-containing CaP matrices for future use in bone regeneration, additional in vivo studies must be conducted to explain the mobility of zinc at the CaP surface and its interactions with a biological medium. - Highlights: • We produced a hydroxyapatite containing a low concentration (0.3 wt.%) of zinc. • The biomaterial underwent characterization before and after in vivo implant. • In vivo tests were performed according to ISO 10993-6. • Zinc-containing calcium phosphate promotes osteoconduction and bone regeneration. • Zinc-containing calcium phosphate may be useful for clinical applications.

  1. [Wide band tympanometry energy reflectance in Chinese infants and children with normal outer and middle ears]. (United States)

    Lei, Yibo; Lu, Wei; Mo, Lingyan


    To explore the law of wide band tympanometry energy reflectance (WBTER) in Chinese infants of Han nationality with normal outer and middle ears, and to provide the normal values for the clinical application of WBTER. Ninety four infants (170 ears) of Han nationality with normal outer and middle ears evidenced by temporal bone CT, and 226 Hz and 1 000 Hz tympanometry at the ages between three and 48 months (median age: 14 months) were selected and divided into four groups: 3-6 months (32 ears), 7-12 months (53 ears), 13-24 months (46 ears) and 25-48 months (39 ears). WBTER was conducted on these infants, and the basic law of energy reflectance under different frequencies, as well as the influence of age on energy reflectance were analyzed using SPSS 15.0. The normal value of energy reflectance was higher at low frequency, gradually decreased with the increase of frequency, reached the minimum near 4 000 Hz , followed by constantly increased till 8 000 Hz. In the scope of frequency below 1 000 Hz and above 6 350 Hz, the energy reflectance values of infants in the group of 3-6 months were significantly lower than those of infants in other age groups (P reflectance and lower fluctuation. The pattern of energy reflectance across frequency range for Chinese infants and children was consistent with that of other races reported in foreign countries. The WBTER changes with the growing of age, which tends to be stable after the first six months of birth.

  2. Calcium (United States)

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

  3. A comparative study of serum uric acid, glucose, calcium and magnesium in pre-eclampsia and normal pregnancy

    Directory of Open Access Journals (Sweden)

    Arun Dhungana


    Full Text Available Background: Preeclampsia is associated with liver function abnormalities and renal function impairment. The objective of this study is to compare serum uric acid, glucose, calcium and magnesium in pre-eclampsia with normal pregnancy. Materials and Methods: Normal pregnant women and pre eclamptic women of age group 20-40 years were included. Serum magnesium, calcium, glucose, uric acid were analyzed.Results: Mean serum magnesium level in preeclampsia (1.83 ± 0.21mg/dl was lesser in comparison to normal pregnant women (2.03 ± 0.16 mg/dl. Serum calcium level was lower (8.10 ±0.56mg/dl than control (9.59 ±0.62 mg/dl with p<0.001. Uric acid, glucose and lactate dehydrogenase in preeclamptic women was significantly higher than that in normal pregnant women (6.14 ± 0.85 vs.4.01 ± 0.62, p=<0.001, (94.17± 18.65 vs.86.34 ± 10.19, p=0.033 and ( 466.80 ± 97.29 vs. 194.22 ± 39.76, p=<0.001 respectively.Conclusion: There were significant changes in serum magnesium, uric acid, calcium, glucose, lactate dehydrogenase and total protein in pregnant women.

  4. Reflection and transmission of full-vector X-waves normally incident on dielectric half spaces

    KAUST Repository

    Salem, Mohamed


    The reflection and transmission of full-vector X-Waves incident normally on a planar interface between two lossless dielectric half-spaces are investigated. Full-vector X-Waves are obtained by superimposing transverse electric and magnetic polarization components, which are derived from the scalar X-Wave solution. The analysis of transmission and reflection is carried out via a straightforward but yet effective method: First, the X-Wave is decomposed into vector Bessel beams via the Bessel-Fourier transform. Then, the reflection and transmission coefficients of the beams are obtained in the spectral domain. Finally, the transmitted and reflected X-Waves are obtained via the inverse Bessel-Fourier transform carried out on the X-wave spectrum weighted with the corresponding coefficient. © 2011 IEEE.

  5. Applications of calcium electroporation to effective apoptosis induction in fibrosarcoma cells and stimulation of normal muscle cells. (United States)

    Zielichowska, Anna; Daczewska, Małgorzata; Saczko, Jolanta; Michel, Olga; Kulbacka, Julita


    The electroporation (EP) supports various types of anticancer therapies by the selective transport of cytostatics. Increase in intracellular calcium level by EP may be a new approach to fibrosarcoma treatment. Calcium is one of the most important factors of cell proliferation, differentiation and cell death (apoptosis or necrosis). Calcium level balanced by electroporation can cause different effects on normal and pathological cells. The efficiency and safety of electroporation combined with Ca(2+) ions were examined in our study. The two muscle cell lines were used: normal rat skeletal muscle cells - L6 and cancer muscle cells - Wehi-164 (fibrosarcoma). Two CaCl2 concentrations were tested: 0.5 mM and 5 mM combined with EP parameters: 1000 V/cm, 1200 V/cm, and 1500 V/cm. The results show that EP supported by Ca(2+) is cytotoxic for Wehi-164 cells and simultaneously safe for normal muscle cells. The main type of cell death - apoptosis - was confirmed by Tunnel and Annexin V/PI assay. Additionally, sPLA2 pro-tumorigenic influence was proved by immunocytochemistry. Moreover, EP with 0.5 mM of Ca(2+) slightly stimulates the normal muscle cells - L6 to increase proliferation. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Inhibition of choroidal angiogenesis by calcium dobesilate in normal Wistar and diabetic GK rats. (United States)

    Lameynardie, Stéphane; Chiavaroli, Carlo; Travo, Pierre; Garay, Ricardo P; Parés-Herbuté, Núria


    Calcium dobesilate reduces vascular endothelial growth factor (VEGF) over-expression in diabetic rat retina, but its effect on intraocular angiogenesis is unknown. Therefore, we tested calcium dobesilate for its in vitro and ex vivo effects on choroidal explant angiogenesis in spontaneously diabetic Goto-Kakizaki (GK) rats. Choroidal explants were cultured in gels of collagen. Budded microvessels numbers and VEGF formation were taken as markers of angiogenesis. Ex vivo studies were performed in GK rats orally given 100 mg/kg/day calcium dobesilate for 10 days. In vitro, calcium dobesilate dose- and time-dependently inhibited both microvessel formation and VEGF production, at concentrations >or=25 mug/ml (i.e. >or=60 microM), with complete inhibition at 100 microg/ml. Oral treatment of diabetic GK rats with calcium dobesilate induced a significant reduction of choroidal angiogenesis ex vivo (38.8% after 3 days of culture). In conclusion, calcium dobesilate inhibited choroidal explant angiogenesis both in vitro and ex vivo. This effect may be due, at least in part, to inhibition of VEGF production. Antiangiogenesis by calcium dobesilate can be involved in its therapeutic benefit in diabetic retinopathy.

  7. Reflectance Measures from Infant Ears With Normal Hearing and Transient Conductive Hearing Loss. (United States)

    Voss, Susan E; Herrmann, Barbara S; Horton, Nicholas J; Amadei, Elizabeth A; Kujawa, Sharon G


    The objective is to develop methods to utilize newborn reflectance measures for the identification of middle-ear transient conditions (e.g., middle-ear fluid) during the newborn period and ultimately during the first few months of life. Transient middle-ear conditions are a suspected source of failure to pass a newborn hearing screening. The ability to identify a conductive loss during the screening procedure could enable the referred ear to be either (1) cleared of a middle-ear condition and recommended for more extensive hearing assessment as soon as possible, or (2) suspected of a transient middle-ear condition, and if desired, be rescreened before more extensive hearing assessment. Reflectance measurements are reported from full-term, healthy, newborn babies in which one ear referred and one ear passed an initial auditory brainstem response newborn hearing screening and a subsequent distortion product otoacoustic emission screening on the same day. These same subjects returned for a detailed follow-up evaluation at age 1 month (range 14 to 35 days). In total, measurements were made on 30 subjects who had a unilateral refer near birth (during their first 2 days of life) and bilateral normal hearing at follow-up (about 1 month old). Three specific comparisons were made: (1) Association of ear's state with power reflectance near birth (referred versus passed ear), (2) Changes in power reflectance of normal ears between newborn and 1 month old (maturation effects), and (3) Association of ear's newborn state (referred versus passed) with ear's power reflectance at 1 month. In addition to these measurements, a set of preliminary data selection criteria were developed to ensure that analyzed data were not corrupted by acoustic leaks and other measurement problems. Within 2 days of birth, the power reflectance measured in newborn ears with transient middle-ear conditions (referred newborn hearing screening and passed hearing assessment at age 1 month) was significantly

  8. Plasma and erythrocyte magnesium, manganese, zinc, and plasma calcium levels in G-6-PD-deficient and normal male children. (United States)

    Sarikcioglu, Süreyya Bilmen; Gümüslü, Saadet; Uysal, Nimet; Aksu, T Aslan


    Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is the most common human enzymopathy in the world. Trace elements are important for normal hematopoiesis and can play a role in acute hemolytic anemia induced by G-6-PD deficiency. For this purpose, we studied two groups consisting of 10 male children who are G-6-PD-deficient and 12 age-matched normal male children to compare plasma and erythrocyte magnesium, manganese, zinc, and plasma calcium levels between G-6-PD-deficient and normal children. All assays were performed under normal conditions free of any oxidative attack that may result in hemolytic crisis in G-6-PD-deficient subjects. All parameters in each group did not differ significantly except for erythrocyte G-6-PD activities. These data show that plasma and erythrocyte trace element contents of G-6-PD-deficient subjects do not differ in normal conditions.

  9. Ear-Canal Reflectance, Umbo Velocity and Tympanometry in Normal Hearing Adults (United States)

    Rosowski, John J; Nakajima, Hideko H.; Hamade, Mohamad A.; Mafoud, Lorice; Merchant, Gabrielle R.; Halpin, Christopher F.; Merchant, Saumil N.


    Objective This study compares measurements of ear-canal reflectance (ECR) to other objective measurements of middle-ear function including, audiometry, umbo velocity (VU), and tympanometry in a population of strictly defined normal hearing ears. Design Data were prospectively gathered from 58 ears of 29 normal hearing subjects, 16 female and 13 male, aged 22–64 years. Subjects met all of the following criteria to be considered as having normal hearing. (1) No history of significant middle-ear disease. (2) No history of otologic surgery. (3) Normal tympanic membrane (TM) on otoscopy. (4) Pure-tone audiometric thresholds of 20 dB HL or better for 0.25 – 8 kHz. (5) Air-bone gaps no greater than 15 dB at 0.25 kHz and 10 dB for 0.5 – 4 kHz. (6) Normal, type-A peaked tympanograms. (7) All subjects had two “normal” ears (as defined by these criteria). Measurements included pure-tone audiometry for 0.25 – 8 kHz, standard 226 Hz tympanometry, Ear canal reflectance(ECR) for 0.2 – 6 kHz at 60 dB SPL using the Mimosa Acoustics HearID system, and Umbo Velocity (VU ) for 0.3 – 6 kHz at 70–90 dB SPL using the HLV-1000 laser Doppler vibrometer (Polytec Inc). Results Mean power reflectance (|ECR|2) was near 1.0 at 0.2– 0.3 kHz, decreased to a broad minimum of 0.3 to 0.4 between 1 and 4 kHz, and then sharply increased to almost 0.8 by 6 kHz. The mean pressure reflectance phase angle (∠ECR) plotted on a linear frequency scale showed a group delay of approximately 0.1 ms for 0.2 – 6 kHz. Small significant differences were observed in |ECR|2 at the lowest frequencies between right and left ears, and between males and females at 4 kHz. |ECR|2 decreased with age, but reached significance only at 1 kHz. Our ECR measurements were generally similar to previous published reports. Highly significant negative correlations were found between |ECR|2 and VU for frequencies below 1 kHz. Significant correlations were also found between the tympanometrically determined peak

  10. The Normalization of Surface Anisotropy Effects Present in SEVIRI Reflectances by Using the MODIS BRDF Method (United States)

    Proud, Simon Richard; Zhang, Qingling; Schaaf, Crystal; Fensholt, Rasmus; Rasmussen, Mads Olander; Shisanya, Chris; Mutero, Wycliffe; Mbow, Cheikh; Anyamba, Assaf; Pak, Ed; hide


    A modified version of the MODerate resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF) algorithm is presented for use in the angular normalization of surface reflectance data gathered by the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) aboard the geostationary Meteosat Second Generation (MSG) satellites. We present early and provisional daily nadir BRDFadjusted reflectance (NBAR) data in the visible and near-infrared MSG channels. These utilize the high temporal resolution of MSG to produce BRDF retrievals with a greatly reduced acquisition period than the comparable MODIS products while, at the same time, removing many of the angular perturbations present within the original MSG data. The NBAR data are validated against reflectance data from the MODIS instrument and in situ data gathered at a field location in Africa throughout 2008. It is found that the MSG retrievals are stable and are of high-quality across much of the SEVIRI disk while maintaining a higher temporal resolution than the MODIS BRDF products. However, a number of circumstances are discovered whereby the BRDF model is unable to function correctly with the SEVIRI observations-primarily because of an insufficient spread of angular data due to the fixed sensor location or localized cloud contamination.

  11. Reflection and transmission of normally incident full-vector X waves on planar interfaces

    KAUST Repository

    Salem, Mohamed


    The reflection and transmission of full-vector X waves normally incident on planar half-spaces and slabs are studied. For this purpose, X waves are expanded in terms of weighted vector Bessel beams; this new decomposition and reconstruction method offers a more lucid and intuitive interpretation of the physical phenomena observed upon the reflection or transmission of X waves when compared to the conventional plane-wave decomposition technique. Using the Bessel beam expansion approach, we have characterized changes in the field shape and the intensity distribution of the transmitted and reflected full-vector X waves. We have also identified a novel longitudinal shift, which is observed when a full-vector X wave is transmitted through a dielectric slab under frustrated total reflection condition. The results of our studies presented here are valuable in understanding the behavior of full-vector X waves when they are utilized in practical applications in electromagnetics, optics, and photonics, such as trap and tweezer setups, optical lithography, and immaterial probing. © 2011 Optical Society of America.

  12. Membrane-substrate separation distance assessed by normalized total internal reflection fluorescence microscopy (United States)

    Cardoso Dos Santos, Marcelina; Vézy, Cyrille; Jaffiol, Rodolphe


    As a consequence of the recent progress in nanoscale technology, more and more sensitive methods are developed to characterize and understand the dynamic of cell membrane adhesion process. In this paper we present a new quantitative method to measure the separation distances between the membrane and the substrate. This technique is based on a normalization of Total Internal Reflection Fluorescence (TIRF) images by usual epi-illumination images. This simple method allows to achieve a nanometric axial resolution, typically 10 nm. We demonstrate the potential of our technique through the study of phospholipids membranes such as Giant Unilamellar Vesicles (GUVs), which are usual biomimetic systems to investigate membrane-substrate interactions.

  13. Shape from specular reflection in calibrated environments and the integration of spatial normal fields

    KAUST Repository

    Balzer, Jonathan


    Reflections of a scene in a mirror surface contain information on its shape. This information is accessible by measurement through an optical metrology technique called deflectometry. The result is a field of normal vectors to the unknown surface having the remarkable property that it equally changes in all spatial directions, unlike normal maps occurring, e.g., in Shape from Shading. Its integration into a zero-order reconstruction of the surface thus deserves special attention. We develop a novel algorithm for this purpose which is relatively straightforward to implement yet outperforms existing ones in terms of efficiency and robustness. Experimental results on synthetic and real data complement the theoretical discussion. © 2011 IEEE.

  14. Effects of Supplemental Vitamin D and Calcium on Normal Colon Tissue and Circulating Biomarkers of Risk for Colorectal Neoplasms (United States)

    Bostick, Roberd M.


    This brief review, based on an invited presentation at the 17th Workshop on Vitamin D, is to summarize a line of the author’s research that has been directed at the intertwined missions of clarifying and/or developing vitamin D and calcium and as preventive agents against colorectal cancer in humans, understanding the mechanisms by which these agents may reduce risk for the disease, and developing ‘treatable’ biomarkers of risk for colorectal cancer. The biological plausibility and observational and clinical trial evidence for vitamin D and calcium in reducing risk for colorectal neoplasms, the development of pre-neoplastic biomarkers of risk for colorectal neoplasms, and the clinical trial findings from the author’s research group on the efficacy of vitamin D and calcium in modulating these biomarkers are summarized. Regarding the latter, we tested the efficacy of 800 IU (20 µg) of vitamin D3 and 2.0g of calcium daily, alone and combined vs. placebo over 6 months on modulating normal colon tissue and circulating hypothesis-based biomarkers of risk for colorectal neoplasms in a randomized, double-blind, placebo-controlled, 2×2 factorial design clinical trial (n = 92). The tissue-based biomarkers were measured in biopsies of normal-appearing rectal mucosa using immunohistochemistry with quantitative image analysis, and a panel of circulating inflammation markers was measured using enzyme-linked immunoassays (ELISA). Statistically significant proportional tissue increases in the vitamin D group relative to the placebo group were found in bax (51%), p21 (141%), APC (48%), E-cadherin (78%), MSH2 (179%), the CaSR (39%), and CYP27B1 (159%). In blood, there was a 77% statistically significant decrease in a summary inflammation z-score. The findings for calcium were similar to those for vitamin D. These findings indicate that supplemental vitamin D3 or calcium can favorably modulate multiple normal colon tissue and circulating hypothesis-based biomarkers of risk

  15. Characterization of Landsat-7 to Landsat-8 Reflective Wavelength and Normalized Difference Vegetation Index Continuity (United States)

    Roy, D. P.; Kovalskyy, V.; Zhang, H. K.; Vermote, E. F.; Yan, L.; Kumar, S. S.; Egorov, A.


    At over 40 years, the Landsat satellites provide the longest temporal record of space-based land surface observations, and the successful 2013 launch of the Landsat-8 is continuing this legacy. Ideally, the Landsat data record should be consistent over the Landsat sensor series. The Landsat-8 Operational Land Imager (OLI) has improved calibration, signal to noise characteristics, higher 12-bit radiometric resolution, and spectrally narrower wavebands than the previous Landsat-7 Enhanced Thematic Mapper (ETM+). Reflective wavelength differences between the two Landsat sensors depend also on the surface reflectance and atmospheric state which are difficult to model comprehensively. The orbit and sensing geometries of the Landsat- 8 OLI and Landsat-7 ETM+ provide swath edge overlapping paths sensed only one day apart. The overlap regions are sensed in alternating backscatter and forward scattering orientations so Landsat bi-directional reflectance effects are evident but approximately balanced between the two sensors when large amounts of time series data are considered. Taking advantage of this configuration a total of 59 million 30m corresponding sensor observations extracted from 6,317 Landsat-7 ETM+ and Landsat-8 OLI images acquired over three winter and three summer months for all the conterminous United States (CONUS) are compared. Results considering different stages of cloud and saturation filtering, and filtering to reduce one day surface state differences, demonstrate the importance of appropriate per-pixel data screening. Top of atmosphere (TOA) and atmospherically corrected surface reflectance for the spectrally corresponding visible, near infrared and shortwave infrared bands, and derived normalized difference vegetation index (NDVI), are compared and their differences quantified. On average the OLI TOA reflectance is greater than the ETM+ TOA reflectance for all bands, with greatest differences in the near-infrared (NIR) and the shortwave infrared bands

  16. Cloning, chromosomal localization, and functional expression of the alpha 1 subunit of the L-type voltage-dependent calcium channel from normal human heart

    NARCIS (Netherlands)

    Schultz, D; Mikala, G; Yatani, A; Engle, D B; Iles, D E; Segers, B; Sinke, R J; Weghuis, D O; Klöckner, U; Wakamori, M


    A unique structural variant of the cardiac L-type voltage-dependent calcium channel alpha 1 subunit cDNA was isolated from libraries derived from normal human heart mRNA. The deduced amino acid sequence shows significant homology to other calcium channel alpha 1 subunits. However, differences from

  17. Baseline Correction of Diffuse Reflection Near-Infrared Spectra Using Searching Region Standard Normal Variate (SRSNV). (United States)

    Genkawa, Takuma; Shinzawa, Hideyuki; Kato, Hideaki; Ishikawa, Daitaro; Murayama, Kodai; Komiyama, Makoto; Ozaki, Yukihiro


    An alternative baseline correction method for diffuse reflection near-infrared (NIR) spectra, searching region standard normal variate (SRSNV), was proposed. Standard normal variate (SNV) is an effective pretreatment method for baseline correction of diffuse reflection NIR spectra of powder and granular samples; however, its baseline correction performance depends on the NIR region used for SNV calculation. To search for an optimal NIR region for baseline correction using SNV, SRSNV employs moving window partial least squares regression (MWPLSR), and an optimal NIR region is identified based on the root mean square error (RMSE) of cross-validation of the partial least squares regression (PLSR) models with the first latent variable (LV). The performance of SRSNV was evaluated using diffuse reflection NIR spectra of mixture samples consisting of wheat flour and granular glucose (0-100% glucose at 5% intervals). From the obtained NIR spectra of the mixture in the 10 000-4000 cm(-1) region at 4 cm intervals (1501 spectral channels), a series of spectral windows consisting of 80 spectral channels was constructed, and then SNV spectra were calculated for each spectral window. Using these SNV spectra, a series of PLSR models with the first LV for glucose concentration was built. A plot of RMSE versus the spectral window position obtained using the PLSR models revealed that the 8680–8364 cm(-1) region was optimal for baseline correction using SNV. In the SNV spectra calculated using the 8680–8364 cm(-1) region (SRSNV spectra), a remarkable relative intensity change between a band due to wheat flour at 8500 cm(-1) and that due to glucose at 8364 cm(-1) was observed owing to successful baseline correction using SNV. A PLSR model with the first LV based on the SRSNV spectra yielded a determination coefficient (R2) of 0.999 and an RMSE of 0.70%, while a PLSR model with three LVs based on SNV spectra calculated in the full spectral region gave an R2 of 0.995 and an RMSE of

  18. Total attenuated reflection infrared analysis of silicon-stabilized tri-calcium phosphate. (United States)

    Dunfield, D; Sayer, M; Shurvell, H F


    Bioceramics based on silicon stabilized tricalcium phosphate [Si-TCP] have been investigated by attenuated total reflection infrared spectroscopy using an experimental preparation that ensures consistent high-quality spectral data. Phase normalized measurements show that changes in OH bands are primarily due to a decrease in the hydroxyapatite content; however, a band at 945 cm(-1) associated with dehydration of the apatite is visible and correlated with silicon doping. Changes in absorption bands with Si content associated with PO(4)(3-) differ for SiO(2) doping levels less than and greater than 0.2 mol of SiO(2)/mol of HA as the amount of Si-TCP phase saturates. Increased resolution allows the study of weak bands linked to Si at 668, 800, 863, and 892 cm(-1) and suggests that the loss of PO(4)(3-) coincides with the development of different silicate groups-SiO(4) at lower doping levels and a new silicon species at higher doping.

  19. Normalizing a Relativistic Model of X-Ray Reflection Definition of the Reflection Fraction and Its Implementation in relxill (United States)

    Dauser, T.; Garcia, J.; Walton, D. J.; Eikmann, W.; Kallman, T.; McClintock, J.; Wilms, J.


    Aims. The only relativistic reflection model that implements a parameter relating the intensity incident on an accretion disk to the observed intensity is relxill. The parameter used in earlier versions of this model, referred to as the reflection strength, is unsatisfactory; it has been superseded by a parameter that provides insight into the accretion geometry, namely the reflection fraction. The reflection fraction is defined as the ratio of the coronal intensity illuminating the disk to the coronal intensity that reaches the observer. Methods. The relxill model combines a general relativistic ray-tracing code and a photoionization code to compute the component of radiation reflected from an accretion that is illuminated by an external source. The reflection fraction is a particularly important parameter for relativistic models with well-defined geometry, such as the lamp post model, which is a focus of this paper. Results. Relativistic spectra are compared for three inclinations and for four values of the key parameter of the lamp post model,namely the height above the black hole of the illuminating, on-axis point source. In all cases, the strongest reflection is produced for low source heights and high spin. A low-spin black hole is shown to be incapable of producing enhanced relativistic reflection. Results for the relxill model are compared to those obtained with other models and a Monte Carlo simulation. Conclusions. Fitting data by using the relxill model and the recently implemented reflection fraction, the geometry of a system can be constrained. The reflection-fraction is independent of system parameters such as inclination and black hole spin. The reflection-fraction parameter was implemented with the name reflec_frac all flavours of the relxill model, and the non-relativistic reflection model xillver, in v0.4a (18 January 2016).

  20. Putative nanobacteria represent physiological remnants and culture by-products of normal calcium homeostasis.

    Directory of Open Access Journals (Sweden)

    John D Young

    Full Text Available Putative living entities called nanobacteria (NB are unusual for their small sizes (50-500 nm, pleomorphic nature, and accumulation of hydroxyapatite (HAP, and have been implicated in numerous diseases involving extraskeletal calcification. By adding precipitating ions to cell culture medium containing serum, mineral nanoparticles are generated that are morphologically and chemically identical to the so-called NB. These nanoparticles are shown here to be formed of amorphous mineral complexes containing calcium as well as other ions like carbonate, which then rapidly acquire phosphate, forming HAP. The main constituent proteins of serum-derived NB are albumin, fetuin-A, and apolipoprotein A1, but their involvement appears circumstantial since so-called NB from different body fluids harbor other proteins. Accordingly, by passage through various culture media, the protein composition of these particles can be modulated. Immunoblotting experiments reveal that antibodies deemed specific for NB react in fact with either albumin, fetuin-A, or both, indicating that previous studies using these reagents may have detected these serum proteins from the same as well as different species, with human tissue nanoparticles presumably absorbing bovine serum antigens from the culture medium. Both fetal bovine serum and human serum, used earlier by other investigators as sources of NB, paradoxically inhibit the formation of these entities, and this inhibition is trypsin-sensitive, indicating a role for proteins in this inhibitory process. Fetuin-A, and to a lesser degree albumin, inhibit nanoparticle formation, an inhibition that is overcome with time, ending with formation of the so-called NB. Together, these data demonstrate that NB are most likely formed by calcium or apatite crystallization inhibitors that are somehow overwhelmed by excess calcium or calcium phosphate found in culture medium or in body fluids, thereby becoming seeds for calcification. The

  1. Multi-Satellite Lambertian Equivalent Reflectivity (Noon Normalized) Daily L3 Global 5.0deg Lat Zones V1 (United States)

    National Aeronautics and Space Administration — The Multi-Satellite Lambertian Equivalent Reflectivity (Noon Normalized) Daily L3 Global 5.0deg Lat Zones data product (MSLERNNL3zm) is derived from observations...

  2. Switching of G-protein Usage by the Calcium-sensing Receptor Reverses Its Effect on Parathyroid Hormone-related Protein Secretion in Normal Versus Malignant Breast Cells*


    Mamillapalli, Ramanaiah; VanHouten, Joshua; Zawalich, Walter; Wysolmerski, John


    The calcium-sensing receptor (CaR) is a G-protein-coupled receptor that signals in response to extracellular calcium and regulates parathyroid hormone secretion. The CaR is also expressed on normal mammary epithelial cells (MMECs), where it has been shown to inhibit secretion of parathyroid hormone-related protein (PTHrP) and participate in the regulation of calcium and bone metabolism during lactation. In contrast to normal breast cells, the CaR has been reported to s...

  3. Nanoscale characterization of vesicle adhesion by normalized total internal reflection fluorescence microscopy. (United States)

    Cardoso Dos Santos, Marcelina; Vézy, Cyrille; Jaffiol, Rodolphe


    We recently proposed a straightforward fluorescence microscopy technique to study adhesion of Giant Unilamellar Vesicles. This technique is based on dual observations which combine epi-fluorescence microscopy and total internal reflection fluorescence (TIRF) microscopy: TIRF images are normalized by epi-fluorescence ones. By this way, it is possible to map the membrane/substrate separation distance with a nanometric resolution, typically ~20 nm, with a maximal working range of 300-400 nm. The purpose of this paper is to demonstrate that this technique is useful to quantify vesicle adhesion from ultra-weak to strong membrane-surface interactions. Thus, we have examined unspecific and specific adhesion conditions. Concerning unspecific adhesion, we have controlled the strength of electrostatic forces between negatively charged vesicles and various functionalized surfaces which exhibit a positive or a negative effective charge. Specific adhesion was highlighted with lock-and-key forces mediated by the well defined biotin/streptavidin recognition. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Developmental Axon Stretch Stimulates Neuron Growth While Maintaining Normal Electrical Activity, Intracellular Calcium Flux, and Somatic Morphology

    Directory of Open Access Journals (Sweden)

    Joseph R Loverde


    Full Text Available Elongation of nerve fibers intuitively occurs throughout mammalian development, and is synchronized with expansion of the growing body. While most tissue systems enlarge through mitosis and differentiation, elongation of nerve fibers is remarkably unique. The emerging paradigm suggests that axons undergo stretch as contiguous tissues enlarge between the proximal and distal segments of spanning nerve fibers. While stretch is distinct from growth, tension is a known stimulus which regulates the growth of axons. Here, we hypothesized that the axon stretch-growth process may be a natural form of injury, whereby regenerative processes fortify elongating axons in order to prevent disconnection. Harnessing the live imaging capability of our axon stretch-growth bioreactors, we assessed neurons both during and following stretch for biomarkers associated with injury. Utilizing whole-cell patch clamp recording, we found no evidence of changes in spontaneous action potential activity or degradation of elicited action potentials during real-time axon stretch at strains of up to 18 % applied over 5 minutes. Unlike traumatic axonal injury, functional calcium imaging of the soma revealed no shifts in free intracellular calcium during axon stretch. Finally, the cross-sectional areas of nuclei and cytoplasms were normal, with no evidence of chromatolysis following week-long stretch-growth limited to the lower of 25 % strain or 3 mm total daily stretch. The neuronal growth cascade coupled to stretch was concluded to be independent of the changes in membrane potential, action potential generation, or calcium flux associated with traumatic injury. While axon stretch-growth is likely to share overlap with regenerative processes, we conclude that developmental stretch is a distinct stimulus from traumatic axon injury.

  5. Developmental axon stretch stimulates neuron growth while maintaining normal electrical activity, intracellular calcium flux, and somatic morphology. (United States)

    Loverde, Joseph R; Pfister, Bryan J


    Elongation of nerve fibers intuitively occurs throughout mammalian development, and is synchronized with expansion of the growing body. While most tissue systems enlarge through mitosis and differentiation, elongation of nerve fibers is remarkably unique. The emerging paradigm suggests that axons undergo stretch as contiguous tissues enlarge between the proximal and distal segments of spanning nerve fibers. While stretch is distinct from growth, tension is a known stimulus which regulates the growth of axons. Here, we hypothesized that the axon stretch-growth process may be a natural form of injury, whereby regenerative processes fortify elongating axons in order to prevent disconnection. Harnessing the live imaging capability of our axon stretch-growth bioreactors, we assessed neurons both during and following stretch for biomarkers associated with injury. Utilizing whole-cell patch clamp recording, we found no evidence of changes in spontaneous action potential activity or degradation of elicited action potentials during real-time axon stretch at strains of up to 18% applied over 5 min. Unlike traumatic axonal injury, functional calcium imaging of the soma revealed no shifts in free intracellular calcium during axon stretch. Finally, the cross-sectional areas of nuclei and cytoplasms were normal, with no evidence of chromatolysis following week-long stretch-growth limited to the lower of 25% strain or 3 mm total daily stretch. The neuronal growth cascade coupled to stretch was concluded to be independent of the changes in membrane potential, action potential generation, or calcium flux associated with traumatic injury. While axon stretch-growth is likely to share overlap with regenerative processes, we conclude that developmental stretch is a distinct stimulus from traumatic axon injury.

  6. The calcium-binding protein S100P in normal and malignant human tissues

    Directory of Open Access Journals (Sweden)

    Pastorek Jaromir


    Full Text Available Abstract Background S100P is a Ca2+ binding protein overexpressed in a variety of cancers, and thus, has been considered a potential tumor biomarker. Very little has been studied about its normal expression and functions. Methods We examined S100P expression in normal human tissues by quantitative reverse transcription polymerase chain reaction and immunohistochemistry. S100P protein expression was also studied in a series of tumors, consisting of 74 ovarian, 11 pancreatic, 56 gastric, 57 colorectal, 89 breast and 193 prostate carcinomas using a novel anti-S100P monoclonal antibody. Results Among the normal tissues, the highest S100P mRNA levels were observed in the placenta and esophagus. Moderate signals were also detected in the stomach, duodenum, large intestine, prostate and leukocytes. At the protein level, the highest reactions for S100P were seen in the placenta and stomach. Immunostaining of tumor specimens showed that S100P protein is expressed in all the tumor categories included in the study, being most prevalent in gastric tumors. Conclusion Based on our observations, S100P is widely expressed in both normal and malignant tissues. The high expression in some tumors suggests that it may represent a potential target molecule for future diagnostic and therapeutic applications.

  7. Evidence for a role of intracellular stored parathyroid hormone in producing hysteresis of the PTH-calcium relationship in normal humans

    DEFF Research Database (Denmark)

    Schwarz, Peter; Madsen, J C; Rasmussen, A Q


    OBJECTIVE: Despite the clear recognition that extracellular ionized calcium controls PTH secretion, there have been suggestions of hysteresis in the relationship between extracellular ionized calcium and PTH during recovery from induced hypo- and hypercalcaemia in vivo in humans. In this study, we...... examined the possibility that release of intracellular stored PTH during induced hypocalcaemia may explain hysteresis. VOLUNTEERS: Eleven volunteers, five women and six men, were recruited to participate in the study. DESIGN: A series of three protocols of repeated induction of hypocalcaemia or sequential...... depot PTH can explain, at least in part, the observed hysteretic PTH-calcium relationship in normal humans....

  8. Triggered intracellular calcium waves in dog and human left atrial myocytes from normal and failing hearts. (United States)

    Aistrup, Gary L; Arora, Rishi; Grubb, Søren; Yoo, Shin; Toren, Benjamin; Kumar, Manvinder; Kunamalla, Aaron; Marszalec, William; Motiwala, Tej; Tai, Shannon; Yamakawa, Sean; Yerrabolu, Satya; Alvarado, Francisco J; Valdivia, Hector H; Cordeiro, Jonathan M; Shiferaw, Yohannes; Wasserstrom, John Andrew


    Abnormal intracellular Ca2+ cycling contributes to triggered activity and arrhythmias in the heart. We investigated the properties and underlying mechanisms for systolic triggered Ca2+ waves in left atria from normal and failing dog hearts. Intracellular Ca2+ cycling was studied using confocal microscopy during rapid pacing of atrial myocytes (36 °C) isolated from normal and failing canine hearts (ventricular tachypacing model). In normal atrial myocytes (NAMs), Ca2+ waves developed during rapid pacing at rates ≥ 3.3 Hz and immediately disappeared upon cessation of pacing despite high sarcoplasmic reticulum (SR) load. In heart failure atrial myocytes (HFAMs), triggered Ca2+ waves (TCWs) developed at a higher incidence at slower rates. Because of their timing, TCW development relies upon action potential (AP)-evoked Ca2+ entry. The distribution of Ca2+ wave latencies indicated two populations of waves, with early events representing TCWs and late events representing conventional spontaneous Ca2+ waves. Latency analysis also demonstrated that TCWs arise after junctional Ca2+ release has occurred and spread to non-junctional (cell core) SR. TCWs also occurred in intact dog atrium and in myocytes from humans and pigs. β-adrenergic stimulation increased Ca2+ release and abolished TCWs in NAMs but was ineffective in HFAMs making this a potentially effective adaptive mechanism in normals but potentially arrhythmogenic in HF. Block of Ca-calmodulin kinase II also abolished TCWs, suggesting a role in TCW formation. Pharmacological manoeuvres that increased Ca2+ release suppressed TCWs as did interventions that decreased Ca2+ release but these also severely reduced excitation-contraction coupling. TCWs develop during the atrial AP and thus could affect AP duration, producing repolarization gradients and creating a substrate for reentry, particularly in HF where they develop at slower rates and a higher incidence. TCWs may represent a mechanism for the initiation

  9. Calcium Oxalate Stone Agglomeration Inhibition [tm] Reflects Renal Stone-Forming Activity (United States)

    Lindberg, Jill S.; Cole, Francis E.; Romani, William; Husserl, Fred E.; Fuselier, Harold A.; Kok, Dirk J.; Erwin, Donald T.


    Louisiana and other Gulf South states comprise a “Stone Belt” where calcium oxalate stone formers (CaOx SFs) are found at a high rate of approximately 5%. In these patients, the agglomeration of small stone crystals, which are visible in nearly all morning urine collections, forms stones that can become trapped in the renal parenchyma and the renal pelvis. Without therapy, about half of CaOx SFs repeatedly form kidney stones, which can cause excruciating pain that can be relieved by passage, fragmentation (lithotripsy), or surgical removal. The absence of stones in “normal” patients suggests that there are stone inhibitors in “normal” urines. At the Ochsner Renal Stone Clinic, 24-hour urine samples are collected by the patient and sent to the Ochsner Renal Stone Research Program where calcium oxalate stone agglomeration inhibition [tm] measurements are performed. Urine from healthy subjects and inactive stone formers has demonstrated strongly inhibited stone growth [tm] in contrast to urine from recurrent CaOx SFs. [tm] data from 1500 visits of 700 kidney stone patients have been used to evaluate the risk of recurrence in Ochsner's CaOx SF patients. These data have also been used to demonstrate the interactive roles of certain identified urinary stone-growth inhibitors, citrate and Tamm-Horsfall protein (THP), which can be manipulated with medication to diminish recurrent stone formation. Our goal is to offer patients both financial and pain relief by reducing their stones with optimized medication, using medical management to avoid costly treatments. PMID:21811395

  10. The Efficacy of Calcium Hydroxide Powder mixed with 0.2% Chlorhexidine Digluconate or mixed with Normal Saline as Intracanal Medicament in the Treatment of Apical Periodontitis. (United States)

    Menakaya, Ifeoma N; Adegbulugbe, Ilemobade C; Oderinu, Olabisi H; Shaba, Olufemi P


    To compare the efficacy of calcium hydroxide powder mixed with 0.2% chlorhexidine digluconate or mixed with normal saline as intracanal medicament in the treatment of apical periodontitis. Subjects were 55 in number aged 17 to 60 years. Two-visit conventional root canal treatment was performed on 70 teeth. The teeth were divided by randomization (balloting) into two groups: control group and experimental group, each with 35 teeth treated with calcium hydroxide mixed with normal saline or with 0.2% chlorhexidine digluconate as intracanal medicament respectively. All treated teeth were evaluated clinically and radiographically for signs and symptom of periapical infection at specified periods postoperatively. Overall efficacy of medicament was rated based on quality guidelines for endodontic treatment by the European Society of Endodontology 2006. A postoperative favorable outcome of 97.1% in the control group and 94.3% in the experimental group was observed at 6-month review. This difference was not statistically significant (p > 0.05). The use of normal saline or 0.2% chlorhexidine digluconate to mix calcium hydroxide used as intracanal medicament during endodontic treatment resulted in high postoperative favorable outcomes. Efficacy of 0.2% chlorhexidine digluconate as a vehicle for mixing calcium hydroxide as an intracanal medicament in the treatment of apical periodontitis is comparable to the efficacy of calcium hydroxide mixed with normal saline.

  11. Voltage-activated currents through calcium channels in normal bovine lactotrophs. (United States)

    Cobbett, P; Ingram, C D; Mason, W T


    The properties of whole cell Ba2+ currents were studied in immunocytochemically identified, normal bovine lactotrophs using the patch clamp technique. In the current clamp mode, current-induced and spontaneous Ba2+ action potentials were recorded. These were of longer duration and showed less inactivation with stimulation frequency when compared with Na+ action potentials. Under voltage clamp, isolated Ba2+ currents had an activation threshold of about -35 mV and peak value at -15 mV to +20 mV. Inactivation of the current to a potential-dependent, non-zero steady-state level indicated the presence of one rapidly and one slowly inactivating component to the current. These two components were also distinguished by: (1) the voltage dependence of the inactivation time constant of the current, (2) the differential frequency-dependent inactivation of the peak and steady-state currents, and (3) the presence of two half-inactivation potentials for the current. Analysis of the ensemble current variance of the non-inactivating component gave a single-channel amplitude of 0.19 pA at 0 mV and a slope conductance of 3 pS. Fluctuation analysis of the voltage-activated Ba2+ current noise revealed two time constants, one which was voltage dependent and the other was independent of potential. The contribution of these two currents to Ca2+-dependent hormone secretion remains to be clarified.

  12. Reflections

    Indian Academy of Sciences (India)

    REFLECTIONS. A freer life and independent work made of the quiet, dreamy boy a happy, outgoing, universally liked young man. He also began to familiarize himself with classical German literature. Though at first he was acquainted only with Milan and Pavia, Italy made a great impression on him even with this limitation.

  13. Gated-SPECT myocardial perfusion imaging and coronary calcium score for evaluation of patients with acute chest pain and a normal or nondiagnostic electrocardiogram. (United States)

    Peix, Amalia; Batista, Elida; Cabrera, Lázaro O; Rodríguez, Lydia; Padrón, Kenia; Saínz, Benito; Mendoza, Vladimir; Carrillo, Regla; Fernández, Yoel; Mena, Erick; Dondi, Maurizio


    To assess the ability of rest myocardial perfusion imaging (MPI) to rule out an acute coronary syndrome (ACS) in emergency department patients, as well as to investigate whether there exists a concordance between MPI and coronary calcium. Fifty-five patients with chest pain and a normal or nondiagnostic ECG were included. Clinical follow-up was carried out within 1 year. Sixteen patients (29%) showed an abnormal rest MPI, and in 11 (20%) the MPI was equivocal. There was a weak concordance between MPI and coronary arteries calcium score (CACS) (κ: 0.25). Coronary angiogram driven by a positive MPI was performed in 12 patients (23%), resulting in percutaneous coronary intervention in nine cases (75%). A positive MPI (abnormal or equivocal results) was associated with the occurrence of events in the follow-up (χ(2)=19.961, Ppatient presenting to the emergency department with acute chest pain and a normal or nondiagnostic ECG, with a positive MPI, the relative risk of having events during the first year was 7.5 (95% confidence interval: 2.8-19.2), Ppatients were free of events. Patients presenting with acute chest pain and a low-to-intermediate likelihood of coronary artery disease with a normal rest MPI have a very low probability of cardiac events during the first year. Coronary calcium score was not helpful in risk-stratifying these patients. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

  14. Breast Cancer Stem Cells Transition between Epithelial and Mesenchymal States Reflective of their Normal Counterparts

    Directory of Open Access Journals (Sweden)

    Suling Liu


    Full Text Available Previous studies have suggested that breast cancer stem cells (BCSCs mediate metastasis, are resistant to radiation and chemotherapy, and contribute to relapse. Although several BCSC markers have been described, it is unclear whether these markers identify the same or independent BCSCs. Here, we show that BCSCs exist in distinct mesenchymal-like (epithelial-mesenchymal transition [EMT] and epithelial-like (mesenchymal-epithelial transition [MET] states. Mesenchymal-like BCSCs characterized as CD24−CD44+ are primarily quiescent and localized at the tumor invasive front, whereas epithelial-like BCSCs express aldehyde dehydrogenase (ALDH, are proliferative, and are located more centrally. The gene-expression profiles of mesenchymal-like and epithelial-like BCSCs are remarkably similar across different molecular subtypes of breast cancer, and resemble those of distinct basal and luminal stem cells found in the normal breast. We propose that the plasticity of BCSCs that allows them to transition between EMT- and MET-like states endows these cells with the capacity for tissue invasion, dissemination, and growth at metastatic sites.

  15. Autofluorescence imaging with near-infrared excitation:normalization by reflectance to reduce signal from choroidal fluorophores. (United States)

    Cideciyan, Artur V; Swider, Malgorzata; Jacobson, Samuel G


    We previously developed reduced-illuminance autofluorescence imaging (RAFI) methods involving near-infrared (NIR) excitation to image melanin-based fluorophores and short-wavelength (SW) excitation to image lipofuscin-based flurophores. Here, we propose to normalize NIR-RAFI in order to increase the relative contribution of retinal pigment epithelium (RPE) fluorophores. Retinal imaging was performed with a standard protocol holding system parameters invariant in healthy subjects and in patients. Normalized NIR-RAFI was derived by dividing NIR-RAFI signal by NIR reflectance point-by-point after image registration. Regions of RPE atrophy in Stargardt disease, AMD, retinitis pigmentosa, choroideremia, and Leber congenital amaurosis as defined by low signal on SW-RAFI could correspond to a wide range of signal on NIR-RAFI depending on the contribution from the choroidal component. Retinal pigment epithelium atrophy tended to always correspond to high signal on NIR reflectance. Normalizing NIR-RAFI reduced the choroidal component of the signal in regions of atrophy. Quantitative evaluation of RPE atrophy area showed no significant differences between SW-RAFI and normalized NIR-RAFI. Imaging of RPE atrophy using lipofuscin-based AF imaging has become the gold standard. However, this technique involves bright SW lights that are uncomfortable and may accelerate the rate of disease progression in vulnerable retinas. The NIR-RAFI method developed here is a melanin-based alternative that is not absorbed by opsins and bisretinoid moieties, and is comfortable to view. Further development of this method may result in a nonmydriatic and comfortable imaging method to quantify RPE atrophy extent and its expansion rate.

  16. Effects of Tamm-Horsfall protein with normal and reduced sialic acid content upon the crystallization of calcium phosphate and calcium oxalate in human urine

    National Research Council Canada - National Science Library

    Hallson, P C; Choong, S K; Kasidas, G P; Samuell, C T


    To examine the effects of Tamm-Horsfall protein (THP) of normal and low sialic acid content on urinary crystallization, and establish whether there are changes conducive to the formation of kidney stones...

  17. Biochemistry of the normal dura mater of the human brain determination of water, sodium, potassium, calcium, phosphorus, magnesium, copper, iron, sulfur and nitrogen contents

    Directory of Open Access Journals (Sweden)

    Horacio M. Canelas


    Full Text Available The concentrations of water, sodium, potassium, calcium, phosphorus, magnesium, copper, iron, sulfur, and nitrogen were determined in samples of apparently normal dura mater removed from 18 subjects recently dead by craniocerebral trauma. The average concentrations expressed in dry weight were: water 79.55 g/100 g ± 2.52; sodium 1.63 mequiv/100 g ±0.27; potassium 3.68 mequiv/100 g ± 0.66; calcium 119.84 mg/100 g ± 107.40; phosphorus 68.2 mg/100 g ± 34.5; magnesium 0.61 mequiv/100 g ± 0.37; copper 249.8 /xg/100 g ± 109.4; iron 0.82 mg/100 g ± 0.28; sulfur 490.7 mg/100 g ± 22.5; nitrogen 3.33 g/100 g ± 0.17.

  18. Multi-Satellite Lambertian Equivalent Reflectivity (Noon Normalized) 1 day L3 Global 5.0deg Lat Zones V1 (MSLERNNL3zm) at GES DISC (United States)

    National Aeronautics and Space Administration — The Multi-Satellite Lambertian Equivalent Reflectivity (Noon Normalized) 1 day L3 Global 5.0deg Lat Zones data product (MSLERNNL3zm) is derived from observations...

  19. Dietary polydextrose increases calcium absorption in normal rats Polidextrose aumenta a absorção de cálcio em ratos

    Directory of Open Access Journals (Sweden)

    Elisvânia Freitas dos Santos


    Full Text Available BACKGROUND: Gastric surgery is known to cause bone disorders, possibly related to an impaired capacity for the absorption of dietary calcium. AIM: To verify if polydextrose (PDX could stimulate calcium absorption in partially gastrectomized and sham operated rats. METHODS: The rats were laparotomized (sham-operated control or partially gastrectomized (Billroth II, in groups of 20 each. Half in each operated group were fed a control diet (AIN-93M without PDX or the same diet containing (PDX 50g/Kg of diet for eight weeks. The rats were divided into four subgroups: sham-operated and gastrectomized without PDX; sham-operated and gastrectomized with PDX. On the final day of the study, total blood was collected for determination of serum calcium concentration. RESULTS: In the diet with PDX, excretion of calcium in the feces was significantly lower than in the groups not receiving PDX, irrespective of the operation. Apparent calcium absorption and serum calcium was higher in the sham operated PDX fed group than in the control group. In sham operated rats, the calcium concentration in bone was higher in the PDX fed group. CONCLUSION: The polydextrose feeding increased calcium absorption and bone calcium concentration in normal rats, which may be relevant for decreasing the risk of osteoporosis. Partially gastrectomy did not affect the bone calcium concentration in 56 days of experimental period.RACIONAL: A cirurgia gástrica é conhecida por causar desordens ósseas, possivelmente relacionado com a absorção do cálcio na dieta. OBJETIVO: verificar se polidextrose (PDX poderia estimular a absorção de cálcio em ratos parcialmente gastrectomizados e ratos sham operados. MÉTODOS: Os ratos foram laparotomizadas (sham-operados de controle ou parcialmente gastrectomizados (Billroth II, em grupos de 20 animais cada. Metade de cada grupo operado foi alimentada com uma dieta controle (AIN-93M sem PDX ou a mesma dieta contendo (PDX 50g/kg de ração durante

  20. Separate effects of urinary chondroitin sulphate and heparan sulphate on the crystallization of urinary calcium oxalate: differences between stone formers and normal control subjects. (United States)

    Shum, D K; Gohel, M D


    1. Urinary glycosaminoglycans were recovered from the papain digest of polyanions precipitated sequentially by cetylpyridinium chloride and sodium acetate-saturated ethanol. Those from the early morning urine of 48 stone formers and 43 normal control subjects measured 11 and 16 micrograms of uronic acid/ml of urine, respectively. 2. Preparative agarose gel electrophoresis of the recovered glycosaminoglycans in barium acetate buffer (pH 5.8) yielded fractions containing purely chondroitin sulphate, co-polymeric chondroitin/dermatan sulphates and heparan sulphate. Identification was based on the susceptibility of the fractions to chondroitinase or nitrous acid treatment. Similar compositions of glycosaminoglycan classes were observed in samples from stone formers and normal control subjects. 3. The fractionated glycosaminoglycans were dissolved in urine ultrafiltrate to assay for nucleation-promoting and growth-inhibiting activities towards crystallization of urinary calcium oxalate. When compared at the same uronic acid concentration, both the urinary chondroitin sulphate isomers and heparan sulphates of stone formers demonstrated the capacity to enhance crystal nucleation from calcium oxalate endogenous in urine ultrafiltrates, whereas only urinary heparan sulphates of normal control subjects demonstrated this capacity. 4. Tissue-derived reference chondroitin sulphate, dermatan sulphate and heparin, when similarly tested, showed negligible crystal nucleation-promoting activity. The tissue-derived heparan sulphate was similar to the urinary heparan sulphates in showing marked crystal nucleation-promoting activity. 5. Crystal-growth inhibitory activity was evident in all urinary glycosaminoglycan fractions studied. In particular, urinary heparan sulphate of normal control subjects showed higher activity than that of stone formers or the chondroitin sulphate isomers of both stone formers and normal control subjects (P < 0.005).

  1. Calcium Electroporation

    DEFF Research Database (Denmark)

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


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

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

    Bu, Wei; Flores, Kevin; Pleasants, Jacob; Vaknin, David


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

  3. Application of the specular and diffuse reflection analysis for in vitro diagnostics of dental erosion: correlation with enamel softening, roughness, and calcium release (United States)

    Rakhmatullina, Ekaterina; Bossen, Anke; Höschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian


    We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration was compared to the increase of enamel roughness. Surface roughness was measured by optical analysis, and the observed tendency was correlated with scanning electron microscopy images of eroded enamel. A high correlation between specular reflection intensity and measurement of enamel softening (r2 >= -0.86) as well as calcium release (r2 >= -0.86) was found during erosion progression. Measurement of diffuse reflection revealed higher tooth-to-tooth deviation in contrast to the analysis of specular reflection intensity and lower correlation with other applied methods (r2 = 0.42-0.48). The proposed optical method allows simple and fast surface analysis and could be used for further optimization and construction of the first noncontact and cost-effective diagnostic tool for early erosion assessment in vivo.

  4. Cortex-wide BOLD fMRI activity reflects locally-recorded slow oscillation-associated calcium waves (United States)

    Backhaus, Hendrik; Kronfeld, Andrea; Aedo Jury, Felipe; Prouvot, Pierre-Hugues; Fois, Consuelo; Albers, Franziska; van Alst, Timo


    Spontaneous slow oscillation-associated slow wave activity represents an internally generated state which is characterized by alternations of network quiescence and stereotypical episodes of neuronal activity - slow wave events. However, it remains unclear which macroscopic signal is related to these active periods of the slow wave rhythm. We used optic fiber-based calcium recordings of local neural populations in cortex and thalamus to detect neurophysiologically defined slow calcium waves in isoflurane anesthetized rats. The individual slow wave events were used for an event-related analysis of simultaneously acquired whole-brain BOLD fMRI. We identified BOLD responses directly related to onsets of slow calcium waves, revealing a cortex-wide BOLD correlate: the entire cortex was engaged in this specific type of slow wave activity. These findings demonstrate a direct relation of defined neurophysiological events to a specific BOLD activity pattern and were confirmed for ongoing slow wave activity by independent component and seed-based analyses. PMID:28914607

  5. Stability of high-dose insulin in normal saline bags for treatment of calcium channel blocker and beta blocker overdose. (United States)

    Laskey, Dayne; Vadlapatla, Rajesh; Hart, Katherine


    High-dose insulin has become a first-line therapy for treating severe calcium channel blocker and beta blocker toxicity. Insulin infusions used to treat other conditions (e.g., diabetic ketoacidosis) may be used, but this may lead to pulmonary compromise due to fluid volume overload. An obvious solution would be to use a more concentrated insulin infusion; however, data describing the stability of insulin in polyvinyl chloride bags at concentrations >1 unit/mL are not readily available. To determine the stability of insulin at 16 units/mL in 0.9% saline solution. Eight-hundred units of regular insulin (8 mL from a stock vial containing 100 units/mL) were added to 42 mL of 0.9% saline solution in a polyvinyl chloride bag to make a final concentration of 16 units/mL. Two bags were stored at 4 °C (refrigerated) and two at 25 °C (room temperature). Samples were withdrawn and tested for insulin concentration periodically over 14 days. Concentrated regular insulin in a polyvinyl chloride bag remained within 90% of equilibrium concentration at all time points, indicating the 16 units/mL concentration was sufficiently stable both refrigerated and at room temperature for 14 days. Administration of high-dose insulin can cause fluid volume overload when using traditional insulin formulations. The 16 units/mL concentration allows for the treatment of a patient with severe calcium channel blocker or beta blocker toxicity for a reasonable period of time without administering excessive fluid. Insulin at a concentration of 16 units/mL is stable for 14 days, the maximum timeframe currently allowed under US Pharmacopeia rules for compounding of sterile preparations. This stability data will allow institutions to issue beyond-use dating for intravenous fluids containing concentrated insulin and used for treating beta blocker and calcium channel blocker toxicity.

  6. Strontium-Doped Calcium Phosphate and Hydroxyapatite Granules Promote Different Inflammatory and Bone Remodelling Responses in Normal and Ovariectomised Rats (United States)

    Xia, Wei; Emanuelsson, Lena; Norlindh, Birgitta; Omar, Omar; Thomsen, Peter


    The healing of bone defects may be hindered by systemic conditions such as osteoporosis. Calcium phosphates, with or without ion substitutions, may provide advantages for bone augmentation. However, the mechanism of bone formation with these materials is unclear. The aim of this study was to evaluate the healing process in bone defects implanted with hydroxyapatite (HA) or strontium-doped calcium phosphate (SCP) granules, in non-ovariectomised (non-OVX) and ovariectomised (OVX) rats. After 0 (baseline), six and 28d, bone samples were harvested for gene expression analysis, histology and histomorphometry. Tumour necrosis factor-α (TNF-α), at six days, was higher in the HA, in non-OVX and OVX, whereas interleukin-6 (IL-6), at six and 28d, was higher in SCP, but only in non-OVX. Both materials produced a similar expression of the receptor activator of nuclear factor kappa-B ligand (RANKL). Higher expression of osteoclastic markers, calcitonin receptor (CR) and cathepsin K (CatK), were detected in the HA group, irrespective of non-OVX or OVX. The overall bone formation was comparable between HA and SCP, but with topological differences. The bone area was higher in the defect centre of the HA group, mainly in the OVX, and in the defect periphery of the SCP group, in both non-OVX and OVX. It is concluded that HA and SCP granules result in comparable bone formation in trabecular bone defects. As judged by gene expression and histological analyses, the two materials induced different inflammatory and bone remodelling responses. The modulatory effects are associated with differences in the spatial distribution of the newly formed bone. PMID:24376855

  7. Very high coronary artery calcium score with normal myocardial perfusion SPECT imaging is associated with a moderate incidence of severe coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Yuoness, Salem A.; Goha, Ahmed M.; Romsa, Jonathan G.; Akincioglu, Cigdem; Warrington, James C.; Datta, Sudip; Gambhir, Sanjay; Urbain, Jean-Luc C.; Vezina, William C. [London Health Sciences Centre, Department of Nuclear Medicine, London, ON (Canada); Massel, David R. [London Health Sciences Centre, Division of Cardiology, London, ON (Canada); Martell, Rafael [Private Practice, London, ON (Canada)


    Myocardial perfusion imaging (MPI) has limitations in the presence of balanced multivessel disease (MVD) and left main (LM) coronary artery disease, occasionally resulting in false-normal results despite the high cardiovascular risk associated with this condition. The purpose of this study was to assess the incidence of severe coronary artery disease (CAD) in the presence of a very high Agatston coronary artery calcium (CAC) score (>1,000) in stable symptomatic patients without known CAD but with normal MPI results. A total of 2,659 prospectively acquired consecutive patients were referred for MPI and evaluation of CAC score by CT. Of this patient population, 8 % (222/2,659) had ischemia without myocardial infarction (MI) on MPI and 11 % (298/2,659) had abnormal MPI (MI and/or ischemia). On presentation 1 % of the patients (26/2,659) were symptomatic, had a CAC score >1,000 and normal MPI results. The definition of normal MPI was strict and included a normal hemodynamic response without ischemic ECG changes and normal imaging, particularly absence of transient ischemic dilation. All of these 26 patients with a CAC score >1,000 and normal MPI findings underwent cardiac catheterization. Of these 26 patients, 58 % (15/26) had severe disease (≥70 % stenosis) leading to revascularization. Of this group, 47 % (7/15) underwent percutaneous intervention, and 53 % (8/15) underwent coronary artery bypass grafting. All of these 15 patients had either MVD (14/15) or LM coronary artery disease (1/15), and represented 0.6 % (15/2,659) of all referred patients (95 % CI 0.3 - 0.9 %). The majority, 90 % (8/9), had severe CAD with typical chest pain. A very high CAC score (>1,000) with normal MPI in a small subset of symptomatically stable patients was associated with a moderate incidence of severe CAD (95 % CI 37 - 77 %). Larger studies and/or a meta-analysis of small studies are needed to more precisely estimate the incidence of CAD in this population. This study also supports

  8. Concentration trends for lead and calcium-normalized lead in fish fillets from the Big River, a mining-contaminated stream in southeastern Missouri USA (United States)

    Schmitt, Christopher J.; McKee, Michael J.


    Lead (Pb) and calcium (Ca) concentrations were measured in fillet samples of longear sunfish (Lepomis megalotis) and redhorse suckers (Moxostoma spp.) collected in 2005–2012 from the Big River, which drains a historical mining area in southeastern Missouri and where a consumption advisory is in effect due to elevated Pb concentrations in fish. Lead tends to accumulated in Ca-rich tissues such as bone and scale. Concentrations of Pb in fish muscle are typically low, but can become elevated in fillets from Pb-contaminated sites depending in part on how much bone, scale, and skin is included in the sample. We used analysis-of-covariance to normalize Pb concentration to the geometric mean Ca concentration (415 ug/g wet weight, ww), which reduced variation between taxa, sites, and years, as was the number of samples that exceeded Missouri consumption advisory threshold (300 ng/g ww). Concentrations of Pb in 2005–2012 were lower than in the past, especially after Ca-normalization, but the consumption advisory is still warranted because concentrations were >300 ng/g ww in samples of both taxa from contaminated sites. For monitoring purposes, a simple linear regression model is proposed for estimating Ca-normalized Pb concentrations in fillets from Pb:Ca molar ratios as a way of reducing the effects of differing preparation methods on fillet Pb variation.

  9. Mineral Trioxide Aggregate Mixed with Normal Saline, Calcium Chloride or KY Jelly as Apical Plug in Simulated Open Apices: An In vitro Microleakage Study (United States)

    Mehrvarzfar, Payman; Akhavan, Hengameh; Ghasemi, Sara; Khodaei, Fatemeh; Tour Savadkouhi, Sohrab; Dianat, Omid


    Introduction: Mineral trioxide aggregate (MTA) mixed with normal saline has short working time, delayed setting time, and poor consistency when used as an apical plug. A preliminary study suggested that substituting normal saline with KY Jelly or 5% calcium chloride (CaCl2) as a vehicle expedites the setting time of MTA. The present in vitro study compared the microleakage of ProRoot MTA mixed with normal saline (MS) to that of ProRoot MTA mixed with KY Jelly and/or 5% CaCl2 in simulated canals with open apices. Materials and methods: Thirty six single-rooted extracted human teeth were cleaned and shaped with ProTaper rotary system to make 36 standardized artificially created open apices. Teeth were randomly divided into three experimental groups (n=10) and two control groups (n=3). In group 1, MTA was mixed with normal saline (MS) and placed into the canals to form 4 to 5 mm apical plugs. In group 2, MTA was mixed with 5% CaCl2 (MC) and in group 3, MTA was mixed with KY Jelly (MK). The other two groups served as positive and negative controls. The remaining canal spaces in the experimental groups were backfilled with thermoplasticized gutta-percha without sealer. Dye penetration and clearing was used to evaluate the sealing ability of each group. The samples were then examined under stereomicroscope to measure the microleakage of different MTA mixtures in mm. Data were statistically analyzed using One-Sample Kolmogorov-Smirnov test for determination of normal distribution and then by one-way ANOVA and Tukey’s tests to detect any significance. Results: Positive and negative controls responded as expected. The MS group showed the least mean dye penetration value. There was a significant difference between MS with other groups (PMTA has the least amount of microleakage in canals with open apices. PMID:24396375

  10. Multi-Satellite Lambertian Equivalent Reflectivity (Noon Normalized) 10-Day L3 Global 2.0x5.0deg Lat/Lon Grid V1 (United States)

    National Aeronautics and Space Administration — The Multi-Satellite Lambertian Equivalent Reflectivity (Noon Normalized) 10-Day L3 Global 2.0x5.0deg Lat/Lon Grid data product is derived from multi-satellite Solar...

  11. 25-Hydroxyvitamin D level does not reflect intestinal calcium absorption: an assay using strontium as a surrogate marker. (United States)

    Camargo, Marília Brasilio Rodrigues; Vilaça, Tatiane; Hayashi, Lilian Fukusima; Rocha, Olguita G Ferreira; Lazaretti-Castro, Marise


    There is conflicting evidence as to the optimal serum 25-hydroxyvitamin D [25(OH)D] concentration for intestinal calcium absorption (Abs-Ca). Our purpose was to assess the relationship between vitamin D status and Abs-Ca in postmenopausal women. Fifty volunteers with low bone mass were grouped according to their serum 25(OH)D concentration as follows: mild deficient, strontium overload test to assess their Abs-Ca. Fasting blood samples were obtained to perform the relevant hormonal and biochemical tests. After the subjects received the test solution, blood samples were drawn at 30, 60, 120, and 240 min to determine the strontium concentrations. Abs-Ca was indirectly expressed as the area under the serum strontium concentration curve (AUC). A repeated measures ANOVA was performed to determine the differences among the groups. Pearson's correlation and multiple linear regression analysis were used to study the associations between the variables. The mean 25(OH)D and 1,25-dihydroxyvitamin D [1,25(OH)2D] concentrations differed between the groups (SUF vs. DEF) as follows: 98.7 ± 18.2 vs. 38.4 ± 8.5 nmol/L (p strontium absorption in the last 2 h of the test. In the studied population, no correlation between levels of 25(OH)D and Abs-Ca was found. Only 1,25(OH)2D influenced Abs-Ca as measured by a strontium absorption test.

  12. Systematic comparison of biologically active foreign ions-codoped calcium phosphate microparticles on osteogenic differentiation in rat osteoporotic and normal mesenchymal stem cells. (United States)

    Chen, Xiao-Yi; Xu, San-Zhong; Wang, Xuan-Wei; Yang, Xian-Yan; Ma, Liang; Zhang, Lei; Yang, Guo-Jing; Yang, Fan; Wang, Lin-Hong; Zhang, Xin-Li; Ting, Kang; Gao, Chang-You; Mou, Xiao-Zhou; Gou, Zhong-Ru; Zou, Hai


    Osteoporosis is a disease characterized by structural deterioration of bone tissue, leading to skeletal fragility with increased fracture risk. Calcium phosphates (CaPs) are widely used in bone tissue engineering strategies as they have similarities to bone apatite except for the absence of trace elements (TEs) in the CaPs. Bioactive glasses (BGs) have also been used successfully in clinic for craniomaxillofacial and dental applications during the last two decades due to their excellent potential for bonding with bone and inducing osteoblastic differentiation. In this study, we evaluated the osteogenic effects of the ionic dissolution products of the quaternary Si-Sr-Zn-Mg-codoped CaP (TEs-CaP) or 45S5 Bioglass® (45S5 BG), both as mixtures and separately, on rat bone marrow-derived mesenchymal stem cells (rOMSCs & rMSCs) from osteoporotic and normal animals, using an MTT test and Alizarin Red S staining. The materials enhanced cell proliferation and osteogenic differentiation, especially the combination of the BG and TEs-CaP. Analysis by quantitative PCR and ELISA indicated that the expression of osteogenic-specific genes and proteins were elevated. These investigations suggest that the TEs-CaP and 45S5 BG operate synergistically to create an extracellular environment that promotes proliferation and terminal osteogenic differentiation of both osteoporotic and normal rMSCs.

  13. Thickness, phase retardation, birefringence, and reflectance of the retinal nerve fiber layer in normal and glaucomatous non-human primates. (United States)

    Dwelle, Jordan; Liu, Shuang; Wang, Bingqing; McElroy, Austin; Ho, Derek; Markey, Mia K; Milner, Thomas; Rylander, H Grady


    We identified candidate optical coherence tomography (OCT) markers for early glaucoma diagnosis. Time variation of retinal nerve fiber layer (RNFL) thickness, phase retardation, birefringence, and reflectance using polarization sensitive optical coherence tomography (PS-OCT) were measured in three non-human primates with induced glaucoma in one eye. We characterized time variation of RNFL thickness, phase retardation, birefringence, and reflectance with elevated intraocular pressure (IOP). One eye of each of three non-human primates was laser treated to increase IOP. Each primate was followed for a 30-week period. PS-OCT measurements were recorded at weekly intervals. Reflectance index (RI) is introduced to characterize RNFL reflectance. Associations between elevated IOP and RNFL thickness, phase retardation, birefringence, and reflectance were characterized in seven regions (entire retina, inner and outer rings, and nasal, temporal, superior and inferior quadrants) by linear and non-linear mixed-effects models. Elevated IOP was achieved in three non-human primate eyes with an average increase of 13 mm Hg over the study period. Elevated IOP was associated with decreased RNFL thickness in the nasal region (P = 0.0002), decreased RNFL phase retardation in the superior (P = 0.046) and inferior (P = 0.021) regions, decreased RNFL birefringence in the nasal (P = 0.002) and inferior (P = 0.029) regions, and loss of RNFL reflectance in the outer rings (P = 0.018). When averaged over the entire retinal area, only RNFL reflectance showed a significant decrease (P = 0.028). Of the measured parameters, decreased RNFL reflectance was the most robust correlate with glaucomatous damage. Candidate cellular mechanisms are considered for decreased RNFL reflectance, including mitochondrial dysfunction and retinal ganglion cell apoptosis.

  14. Reactive oxygen species and calcium signals in skeletal muscle: A crosstalk involved in both normal signaling and disease. (United States)

    Espinosa, Alejandra; Henríquez-Olguín, Carlos; Jaimovich, Enrique


    Reactive Oxygen Species (ROS) have been profusely studied as agents of potential damage to living cells and they have been related to a number of pathological processes. Increasing evidence points to a more positive role of ROS in cell signaling and the detailed mechanism that regulates the precise amount of ROS needed for cell functioning without the deleterious effects of excess ROS still needs to be resolved in detail. In skeletal muscle the main source of ROS during normal functioning appears to be NADPH oxidase 2 (NOX2), which is activated by electrical stimuli (or exercise) through a cascade of events that include ATP release through pannexin1 channels. NOX2 is a protein complex that assembles in the T-tubule membrane before activation and ROS production by NOX2 appears to be important for muscle adaptation through gene expression and mitochondrial biogenesis as well as for improving glucose transport after insulin action. Excess ROS production (or diminished antioxidant defenses) plays a role in a number of pathological processes in skeletal muscle. Together with increased reactive nitrogen species, an increase in ROS appears to have a deleterious role in a model of Duchenne muscular dystrophy as well as muscle wasting in other diseases such as aging sarcopenia and cancer cachexia. In addition, ROS is involved in obesity and muscle insulin resistance, both of which are causally related to type 2 diabetes. A detailed description of the fine-tuning of ROS (including all sources of ROS) in skeletal muscle in health and disease will significantly contribute to our knowledge of both muscle adaptation and muscle related pathologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. High-sensitivity C-reactive protein is associated with the presence of coronary artery calcium in subjects with normal blood pressure but not in subjects with hypertension. (United States)

    Sung, Joo-Wook; Lee, Sung Ho; Byrne, Christopher D; Chung, Pil-Wook; Won, Yu Sam; Sung, Ki-Chul


    An association has been described between high sensitivity C-reactive protein (hs-CRP) and cardiovascular disease (CVD) in some studies but not in others. This finding may be explained by a differential impact of inflammation according to the absence or presence of certain co-existing risk factors. Because hypertension may be an effect modifier of inflammation on CVD, our aim was to investigate the relationship between hs-CRP and pre-clinical atherosclerosis in subjects with normal blood pressure and hypertension. Data were analyzed from 14,584 Korean subjects. Subjects were stratified according to: a) 6030 (41.3%) patients with normal blood pressure (hypertension (120-139 mmHg and 80-89 mmHg) and c) 2924 (20.0%) patients with hypertension (≥140/90 mmHg). Prevalence and odds ratio for the association between increased hs-CRP (>2 mg/L) and presence of CAC (coronary artery calcium) were calculated. In both normal and pre-hypertensive groups, the prevalence of CAC >0 was higher in subjects with increased hs-CRP concentrations (>2 mg/L). Adjusting for age, sex, cerebrovascular accident, coronary heart disease and diabetes mellitus, lifestyle, obesity, fasting glucose, triglyceride, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol concentrations, there was a significant association between higher hs-CRP levels (>2 mg/L) and CAC score in the normal group (OR 1.55, 95% CI 1.11-2.16; p = 0.010); a borderline significant association in the pre-hypertensive group (OR 1.33, 95% CI 0.99-1.76; p = 0.054); and no association in the hypertensive group (OR 1.01, 95% CI 0.76-1.33; p = 0.94). Higher hs-CRP levels (>2 mg/L) are associated with pre-clinical atherosclerosis in subjects with normal blood pressure but not hypertension. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.

  16. Effect of 3-substituted 1,4-benzodiazepin-2-ones on maximal normalized rate of bradykinin-induced smooth muscle contraction in the presence of calcium channel blockers

    Directory of Open Access Journals (Sweden)

    P. A. Virych


    Full Text Available The development of modern organic chemistry and molecular modeling technologies simplify the search for potential inhibitors of various receptor systems and biological processes. The one of the directions is the development of analgesics of broad spectrum and low toxicity. It is important to search for inhibitors of the kinin-kallikrein system that regulates many functions: inflammation, pain, carcinogenesis, vascular tone, smooth muscle contraction and other. Derivatives of 3-substituted 1,4-benzodiazepine-2-ones have a unique spatial conformation that allows one to simulate β-structures of bioactive peptides. The functional activity of compounds is determined by properties of their peripheral chemical radicals. We analyzed the effect of 3-substituted 1,4-benzodiazepin-2-ones derivatives on the normalized maximal rate of bradykinin-induced smooth muscle contraction and relaxation of the stomach in the presence of calcium channel blockers: verapamil (1 μM, gadolinium (300 μM and 2-aminoethyl diphenylborinate (0.1 μM. The levels of bradykinin and 3-arylamino-1,2-dihydro-3H-1,4-benzodiazepine-2-ones in incubation solution were 10–6 M. Data processing on dynamics of contraction was performed according to the method of Burdyha and Kosterin. Compounds MX-1775 and MX-1925 reduced maximal normalized rate (Vn of bradykinin-induced smooth muscle contraction in the presence of Gd3+ by 21.2% and 31.0% respectively. Compound MX-1925 increased Vn of relaxation by 11.6%. A similar effect is typical for MX-2011, where there is an increase by 34.6%. In the presence of verapamil this compound additionally decreased Vn contraction by 20.5%. Substances MX-1775, MX-2004 and MX-1925 restored maximal normalized rate of relaxation to original values of bradykinin-induced contraction. In the presence of 2-aminoethyldiphenylborinate MX-1775 additionally reduced Vn of contractions by 7.5%. 3-substituted 1,4-benzo­diazepine-2-ones did not change the maximal

  17. Differentiating pediatric epileptic brain tissue from normal brain tissue by using time-dependent diffuse reflectance spectroscopy in vivo: comprehensive data analysis method in the time domain (United States)

    Oh, Sanghoon; Fernald, Bradley; Bhatia, Sanjiv; Ragheb, John; Sandberg, David; Johnson, Mahlon; Lin, Wei-Chiang


    This research investigated the feasibility of using time-dependent diffuse reflectance spectroscopy to differentiate pediatric epileptic brain tissue from normal brain tissue. The optical spectroscopic technique monitored the dynamic optical properties of the cerebral cortex that are associated with its physiological, morphological, and compositional characteristics. Due to the transient irregular epileptic discharge activity within the epileptic brain tissue it was hypothesized that the lesion would express abnormal dynamic optical behavior that would alter normal dynamic behavior. Thirteen pediatric epilepsy patients and seven pediatric brain tumor patients (normal controls) were recruited for this clinical study. Dynamic optical properties were obtained from the cortical surface intraoperatively using a timedependent diffuse reflectance spectroscopy system. This system consisted of a fiber-optic probe, a tungsten-halogen light source, and a spectrophotometer. It acquired diffuse reflectance spectra with a spectral range of 204 nm to 932 nm at a rate of 33 spectra per second for approximately 12 seconds. Biopsy samples were taken from electrophysiologically abnormal cortex and evaluated by a neuropathologist, which served as a gold standard for lesion classification. For data analysis, spectral intensity changes of diffuse reflectance in the time domain at two different wavelengths from each investigated site were compared. Negative correlation segment, defined by the periods where the intensity changes at the two wavelengths were opposite in their slope polarity, were extracted. The total duration of negative correlation, referred to as the "negative correlation time index", was calculated by integrating the negative correlation segments. The negative correlation time indices from all investigated sites were sub-grouped according to the corresponding histological classifications. The difference between the mean indices of two subgroups was evaluated by standard

  18. Lipoxin A4 stimulates calcium-activated chloride currents and increases airway surface liquid height in normal and cystic fibrosis airway epithelia.

    LENUS (Irish Health Repository)


    Cystic Fibrosis (CF) is a genetic disease characterised by a deficit in epithelial Cl(-) secretion which in the lung leads to airway dehydration and a reduced Airway Surface Liquid (ASL) height. The endogenous lipoxin LXA(4) is a member of the newly identified eicosanoids playing a key role in ending the inflammatory process. Levels of LXA(4) are reported to be decreased in the airways of patients with CF. We have previously shown that in normal human bronchial epithelial cells, LXA(4) produced a rapid and transient increase in intracellular Ca(2+). We have investigated, the effect of LXA(4) on Cl(-) secretion and the functional consequences on ASL generation in bronchial epithelial cells obtained from CF and non-CF patient biopsies and in bronchial epithelial cell lines. We found that LXA(4) stimulated a rapid intracellular Ca(2+) increase in all of the different CF bronchial epithelial cells tested. In non-CF and CF bronchial epithelia, LXA(4) stimulated whole-cell Cl(-) currents which were inhibited by NPPB (calcium-activated Cl(-) channel inhibitor), BAPTA-AM (chelator of intracellular Ca(2+)) but not by CFTRinh-172 (CFTR inhibitor). We found, using confocal imaging, that LXA(4) increased the ASL height in non-CF and in CF airway bronchial epithelia. The LXA(4) effect on ASL height was sensitive to bumetanide, an inhibitor of transepithelial Cl(-) secretion. The LXA(4) stimulation of intracellular Ca(2+), whole-cell Cl(-) currents, conductances and ASL height were inhibited by Boc-2, a specific antagonist of the ALX\\/FPR2 receptor. Our results provide, for the first time, evidence for a novel role of LXA(4) in the stimulation of intracellular Ca(2+) signalling leading to Ca(2+)-activated Cl(-) secretion and enhanced ASL height in non-CF and CF bronchial epithelia.

  19. Calcium metabolism and cardiovascular function after spaceflight (United States)

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


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

  20. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) in the discrimination of normal and oral cancer blood plasma (United States)

    Pachaiappan, Rekha; Prakasarao, Aruna; Singaravelu, Ganesan


    Oral cancer is the most frequent type of cancer that occurs with 75000 to 80000 new cases reported every year in India. The carcinogens from tobacco and related products are the main cause for the oral cancer. ATR-FTIR method is label free, fast and cost-effective diagnostic method would allow for rapid diagnostic results in earlier stages by the minimal chemical changes occur in the biological metabolites available in the blood plasma. The present study reports the use of ATR-FTIR data with advanced statistical model (LDA-ANN) in the diagnosis of oral cancer from normal with better accuracy. The infrared spectra were acquired on ATR-FTIR Jasco spectrophotometer at 4 cm-1 resolution, 30 scans, in the 1800-900 cm-1 spectral range. Each sample had 5 spectra recorded from each blood plasma sample. The spectral data were routed through the multilayer perception of artificial neural network to evaluate for the statistical efficacy. Among the spectral data it was found that amide II (1486 cm-1) and lipid (1526 cm-1) affords about 90 % in the discrimination between groups using LDA. These preliminary results indicate that ATR-FTIR is useful to differentiate normal subject from oral cancer patients using blood plasma.

  1. Calcium - urine (United States)

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

  2. Normal centrolineal myelination of the callosal splenium reflects the development of the cortical origin and size of its commissural fibers

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, Matthew T. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Children' s National Medical Center, Department of Radiology, Washington, DC (United States); Raju, Anand; Choudhri, Asim F. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States)


    Commissural white matter fibers comprising the callosal splenium are diverse. Subsections of the splenium myelinate at different times, in a centrolineal manner. The aims of this study are to depict the normal callosal splenium myelination pattern and to distinguish the transient age-related mid splenium hypointensity from pathology. We reviewed 131 consecutive brain MRIs in patients between ages 3 and 6 months from a single academic children's hospital. Patients that were preterm, hydrocephalic, and/or had volume loss were excluded. Fifty total MR exams that included T1-weighted MR imaging (T1WI), T2-weighted MR imaging (T2WI), and diffusion tensor imaging (DTI) were reviewed. Regions of callosal splenium myelination manifested by T1 and T2 shortening were evaluated. Tractography was performed with seeds placed over the posterior, mid, and anterior splenium to define the origin, destination, and course of traversing fibers. Splenium signal varied significantly from 3 to 6 months, with distinct age-related trends. On T1WI, the splenium was hypointense at 3 months (12/13), centrally hypointense/peripherally hyperintense at 4 months (15/16), and hyperintense at 6 months (10/11). Tractography revealed three distinct white matter tract populations: medial occipital (posterior); precuneus, posterior cingulate, and medial temporal (middle); and postcentral gyri (anterior). Specific commissural fiber components of the splenium myelinate at different times. The transient developmental mid splenium hypointensity on T1WI corresponds to tracts from the associative cortex, principally the precuneus. Heterogeneous splenium signal alteration in patients ages 3-6 months is a normal developmental phenomenon that should not be confused with pathologic lesions. (orig.)

  3. Stay-green in spring wheat can be determined by spectral reflectance measurements (normalized difference vegetation index) independently from phenology. (United States)

    Lopes, Marta S; Reynolds, Matthew P


    The green area displayed by a crop is a good indicator of its photosynthetic capacity, while chlorophyll retention or 'stay-green' is regarded as a key indicator of stress adaptation. Remote-sensing methods were tested to estimate these parameters in diverse wheat genotypes under different growing conditions. Two wheat populations (a diverse set of 294 advanced lines and a recombinant inbred line population of 169 sister lines derived from the cross between Seri and Babax) were grown in Mexico under three environments: drought, heat, and heat combined with drought. In the two populations studied here, a moderate heritable expression of stay-green was found-when the normalized difference vegetation index (NDVI) at physiological maturity was estimated using the regression of NDVI over time from the mid-stages of grain-filling to physiological maturity-and for the rate of senescence during the same period. Under heat and heat combined with drought environments, stay-green calculated as NDVI at physiological maturity and the rate of senescence, showed positive and negative correlations with yield, respectively. Moreover, stay-green calculated as an estimation of NDVI at physiological maturity and the rate of senescence regressed on degree days give an independent measurement of stay-green without the confounding effect of phenology. On average, in both populations under heat and heat combined with drought environments CTgf and stay-green variables accounted for around 30% of yield variability in multiple regression analysis. It is concluded that stay-green traits may provide cumulative effects, together with other traits, to improve adaptation under stress further.

  4. Calcium Carbonate (United States)

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

  5. Calcium supplements (United States)

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

  6. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to calcium and potassium and maintenance of normal acid-base balance (ID 400, 407) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    within metabolism (intracellular cation)”. The target population is assumed to be the general population. In the context of the proposed wordings, the Panel assumes that the claimed effects refer to the maintenance of normal acid-base balance. The Panel considers that maintenance of normal acid...... claims in relation to calcium and potassium and maintenance of normal acid-base balance. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from...... stakeholders. The food constituents that are the subject of the health claims are calcium and potassium. The Panel considers that calcium and potassium are sufficiently characterised. The claimed effects are “calcium contributes to acid/base balance within metabolism” and “mineral/potassium: key function...

  7. Familial hypocalciuric hypercalcemia and calcium sensing receptor

    DEFF Research Database (Denmark)

    Mrgan, Monija; Nielsen, Sanne; Brixen, Kim


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

  8. Application of the specular and diffuse reflection analysis for in vitro diagnostics of dental erosion: correlation with enamel softening, roughness, and calcium release


    Rakhmatullina, Ekaterina; Bossen, Anke; Höschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian


    We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration w...

  9. Bcl-2 regulation of the inositol 1,4,5-trisphosphate receptor and calcium signaling in normal and malignant lymphocytes: potential new target for cancer treatment. (United States)

    Greenberg, Edward F; Lavik, Andrew R; Distelhorst, Clark W


    The anti-apoptotic protein Bcl-2 is a versatile regulator of cell survival. Its interactions with its own pro-apoptotic family members are widely recognized for their role in promoting the survival of cancer cells. These interactions are thus being targeted for cancer treatment. Less widely recognized is the interaction of Bcl-2 with the inositol 1,4,5-trisphosphate receptor (InsP3R), an InsP3-gated Ca(2+) channel located on the endoplasmic reticulum. The nature of this interaction, the mechanism by which it controls Ca(2+) release from the ER, its role in T-cell development and survival, and the possibility of targeting it as a novel cancer treatment strategy are summarized in this review. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Clinically relevant concentration of pregabalin has no acute inhibitory effect on excitation of dorsal horn neurons under normal or neuropathic pain conditions: An intracellular calcium-imaging study in spinal cord slices from adult rats. (United States)

    Baba, Hiroshi; Petrenko, Andrey B; Fujiwara, Naoshi


    Pregabalin is thought to exert its therapeutic effect in neuropathic pain via binding to α2δ-1 subunits of voltage-gated calcium (Ca(2+)) channels. However, the exact analgesic mechanism after its binding to α2δ-1 subunits remains largely unknown. Whether a clinical concentration of pregabalin (≈10μM) can cause acute inhibition of dorsal horn neurons in the spinal cord is controversial. To address this issue, we undertook intracellular Ca(2+)-imaging studies using spinal cord slices with an intact attached L5 dorsal root, and examined if pregabalin acutely inhibits the primary afferent stimulation-evoked excitation of dorsal horn neurons in normal rats and in rats with streptozotocin-induced painful diabetic neuropathy. Under normal conditions, stimulation of a dorsal root evoked Ca(2+) signals predominantly in the superficial dorsal horn. Clinically relevant (10μM) and a very high concentration of pregabalin (100μM) did not affect the intensity or spread of dorsal root stimulation-evoked Ca(2+) signals, whereas an extremely high dose of pregabalin (300μM) slightly but significantly attenuated Ca(2+) signals in normal rats and in diabetic neuropathic (DN) rats. There was no difference between normal rats and DN rats with regard to the extent of signal attenuation at all concentrations tested. These results suggest that the activity of dorsal horn neurons in the spinal cord is not inhibited acutely by clinical doses of pregabalin under normal or DN conditions. It is very unlikely that an acute inhibitory action in the dorsal horn is the main analgesic mechanism of pregabalin in neuropathic pain states. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. The 18 kDa translocator protein (peripheral benzodiazepine receptor expression in the bone of normal, osteoprotegerin or low calcium diet treated mice.

    Directory of Open Access Journals (Sweden)

    Winnie Wai-Ying Kam

    Full Text Available The presence of the translocator protein (TSPO, previously named as the mitochondrial or peripheral benzodiazepine receptor, in bone cells was studied in vitro and in situ using RT-qPCR, and receptor autoradiography using the selective TSPO ligand PK11195.In vitro, the TSPO is highly expressed in osteoblastic and osteoclastic cells.In situ, constitutive expression of TSPO is found in bone marrow and trabecular bone, e.g., spongiosa. Mice with a reduction of bone turnover induced by a 4-day treatment of osteoprotegerin reduces [(3H]PK11195 binding in the spongiosa (320±128 Bq x mg(-1, 499±106 Bq x mg(-1 in saline-treated controls. In contrast, mice with an increase in bone turnover caused by a 4-day low calcium diet increases [(3H]PK11195 binding in the spongiosa (615±90 Bq x mg(-1. Further, our study includes technical feasibility data on [(18F]fluoride microPET imaging of rodent bone with altered turnover. Despite [(18F]fluoride having high uptake, the in vivo signal differences were small. Using a phantom model, we describe the spillover effect and partial volume loss that affect the quantitative microPET imaging of the small bone structures in experimental mouse models. In summary, we demonstrate the expression of TSPO in small rodent bone tissues, including osteoblasts and osteoclasts. A trend increase in TSPO expression was observed in the spongiosa from low to high bone turnover conditions. However, despite the potential utility of TSPO expression as an in vivo biomarker of bone turnover in experimental rodent models, our small animal PET imaging data using [(18F]fluoride show that even under the condition of a good biological signal-to-noise ratio and high tracer uptake, the currently achievable instrument sensitivity and spatial resolution is unlikely to be sufficient to detect subtle differences in small structures, such as mouse bone.

  12. Evaluation of status of calcium, magnesium, potassium, and sodium levels in biological samples in children of different age groups with normal vision and night blindness. (United States)

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Naveed; Kandhro, Ghulam Abbas; Baig, Jameel Ahmed; Shah, Abdul Qadir; Khan, Sumaira; Kolachi, Nida Fatima; Wadhwa, Sham Kumar; Shah, Faheem


    The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization (WHO) estimates 13.8 million children have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological sample composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of magnesium (Mg), calcium (Ca), potassium (K), and sodium (Na) in scalp hair, serum, blood, and urine of night blindness children in two age groups, (1-5) and (6-10) years, of both genders comparing them to sex- and age-matched controls. A microwave assisted wet acid digestion procedure was developed as a sample pretreatment for the determination of Mg, Ca, K, and Na in biological samples of children with night blindness. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, serum, blood, and urine. The digests of all biological samples were analysed for Mg, Ca, K, and Na by flame atomic absorption spectrometry (FAAS) using an air/acetylene flame. The results indicated significantly lower levels of Mg, Ca, and K in the biological samples (blood, serum, and scalp hair) of male and female children with night blindness and higher values of Na compared with control subjects of both genders. These data present guidance to clinicians and other professionals investigating deficiency of essential mineral elements in biological samples (scalp hair, serum, and blood) of children with night blindness.

  13. Multi-Satellite Lambertian Equivalent Reflectivity (Noon Normalized) 10-Day L3 Global 2.0x5.0deg Lat/Lon Grid V1 (MSLERNNL3d10) at GES DISC (United States)

    National Aeronautics and Space Administration — The Multi-Satellite Lambertian Equivalent Reflectivity (Noon Normalized) 10-Day L3 Global 2.0x5.0deg Lat/Lon Grid data product is derived from multi-satellite Solar...

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

    Karsanov, N V; Khugashvili, Z G


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

  15. Cardiovascular Effects of Calcium Supplements

    Directory of Open Access Journals (Sweden)

    Ian R. Reid


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

  16. Novel Method to Prepare Magnesium by Aluminothermic Reduction of Magnesia and Calcium Hydroxide at Normal Atmosphere, 1223 K (950 °C) (United States)

    Zhang, Teng; Du, Shuang-Ming; Sun, Wan-Chang; Zhang, Ju-Mei; Niu, Li-Bin; Zheng, Bin; Hua, Xiao-Hu


    An experimental apparatus was designed to investigate the aluminothermic reduction of the mixture of MgO and Ca(OH)2 at normal atmosphere, 1223 K (950 °C), with the molar ratio of MgO:Al:Ca(OH)2 to be 3:2:1, reinforced by high-energy ball milling. The effect of mechanical milling time and content of grinding aid (sodium stearate) on the reduction ratio of MgO were studied. Moreover, the reduzate and reactant activated by ball milling were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectrometer analysis. The average grain sizes of Al and MgO activated by ball milling were also calculated by Scherrer formula. The results indicate that the reduction ratio of MgO is increased with increasing mechanical milling time and content of sodium stearate. The high-energy ball milling has good reinforcement on the aluminothermic reduction of MgO. Moreover, the strengthening mechanism of mechanical force on the reaction was further discussed.

  17. Paclitaxel induces apoptosis in breast cancer cells through different calcium--regulating mechanisms depending on external calcium conditions. (United States)

    Pan, Zhi; Avila, Andrew; Gollahon, Lauren


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

  18. Calcium Balance in Chronic Kidney Disease


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


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

  19. Serum antimüllerian hormone levels best reflect the reproductive decline with age in normal women with proven fertility: A longitudinal study

    NARCIS (Netherlands)

    I.A.J. van Rooij (I. A J); F.J.M. Broekmans (Frank); G.J. Scheffer (G.); C.W.N. Looman (Caspar); J.D.F. Habbema (Dik); F.H. de Jong (Frank); B.C.J.M. Fauser (Bart); A.P.N. Themmen (Axel); E.R. te Velde (Egbert)


    textabstractObjective: The aim of this study was to assess which of the basal ovarian reserve markers provides the best reflection of the changes occurring in ovarian function over time (i.e., reproductive aging). Design: Prospective longitudinal study. Setting: Healthy volunteers in an academic

  20. Normal impingement loads due to small air jets issuing from a base plate and reflecting off a platform for various jet Mach numbers, separation distances, and ambient pressures (United States)

    Hoffman, S.


    An investigation was conducted in a 12.5-meter-diameter vacuum sphere to determine the impingement loads due to air jets issuing from and perpendicular to a circular base and reflecting off a square platform, that is, a simulation of rendezvous maneuvering, docking, launch, impact dampers etc. The nozzles had exit Mach numbers of 1, 3, 5, and 7. The ambient pressures were 0.0006, 5, 225, and 760 torr. Under near-field separation distances and at 0.0006 torr, reflections were significant; and ratios of the impingement force to thrust on both plates in the biplane arrangement varied from about 750 for exit Mach number 1 to 120 for exit Mach number 7. The far-field force ratios were near unity for the platform and zero for the base and indicated few, if any, reflections. Some reversals and rapid changes in loads were obtained at transition distances between the near and far fields. In general, increasing the exit Mach number or ambient pressure reduced the impingement loads.

  1. Dystrophin Threshold Level Necessary for Normalization of Neuronal Nitric Oxide Synthase, Inducible Nitric Oxide Synthase, and Ryanodine Receptor-Calcium Release Channel Type 1 Nitrosylation in Golden Retriever Muscular Dystrophy Dystrophinopathy. (United States)

    Gentil, Christel; Le Guiner, Caroline; Falcone, Sestina; Hogrel, Jean-Yves; Peccate, Cécile; Lorain, Stéphanie; Benkhelifa-Ziyyat, Sofia; Guigand, Lydie; Montus, Marie; Servais, Laurent; Voit, Thomas; Piétri-Rouxel, France


    At present, the clinically most advanced strategy to treat Duchenne muscular dystrophy (DMD) is the exon-skipping strategy. Whereas antisense oligonucleotide-based clinical trials are underway for DMD, it is essential to determine the dystrophin restoration threshold needed to ensure improvement of muscle physiology at the molecular level. A preclinical trial has been conducted in golden retriever muscular dystrophy (GRMD) dogs treated in a forelimb by locoregional delivery of rAAV8-U7snRNA to promote exon skipping on the canine dystrophin messenger. Here, we exploited rAAV8-U7snRNA-transduced GRMD muscle samples, well characterized for their percentage of dystrophin-positive fibers, with the aim of defining the threshold of dystrophin rescue necessary for normalization of the status of neuronal nitric oxide synthase mu (nNOSμ), inducible nitric oxide synthase (iNOS), and ryanodine receptor-calcium release channel type 1 (RyR1), crucial actors for efficient contractile function. Results showed that restoration of dystrophin in 40% of muscle fibers is needed to decrease abnormal cytosolic nNOSμ expression and to reduce overexpression of iNOS, these two parameters leading to a reduction in the NO level in the muscle fibers. Furthermore, the same percentage of dystrophin-positive fibers of 40% was associated with the normalization of RyR1 nitrosylation status and with stabilization of the RyR1-calstabin1 complex that is required to facilitate coupled gating. We concluded that a minimal threshold of 40% of dystrophin-positive fibers is necessary for the reinstatement of central proteins needed for proper muscle contractile function, and thus identified a rate of dystrophin expression significantly improving, at the molecular level, the dystrophic muscle physiology.

  2. Pursuing Normality

    DEFF Research Database (Denmark)

    Madsen, Louise Sofia; Handberg, Charlotte


    semistructured interviews with 9 lymphoma survivors. Interpretive description methodology and social practice theory guided the analytical framework. RESULTS: "Pursuing normality" was an overall finding and was comprised of 2 overarching patterns, "future prospects" and "survivorship care perceptions," both......BACKGROUND: The present study explored the reflections on cancer survivorship care of lymphoma survivors in active treatment. Lymphoma survivors have survivorship care needs, yet their participation in cancer survivorship care programs is still reported as low. OBJECTIVE: The aim of this study...... was to understand the reflections on cancer survivorship care of lymphoma survivors to aid the future planning of cancer survivorship care and overcome barriers to participation. METHODS: Data were generated in a hematological ward during 4 months of ethnographic fieldwork, including participant observation and 46...

  3. Membrane sialic acid influences basophil histamine release by interfering with calcium dependence

    DEFF Research Database (Denmark)

    Jensen, C; Norn, S; Skov, P S


    The influence of the cell membrane content of sialic acid on basophil histamine release was examined in vitro in allergic patients and normal controls. Enzymatical removal of sialic acid enhanced histamine release induced by allergen and anti-IgE, whereas an increase in membrane sialic acid content....... This difference, together with the previous finding that alterations in membrane sialic acid content is reflected in the cell sensitivity to extracellular calcium, suggest an interaction between membrane sialic acid and the calcium channels involved in basophil histamine release....

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

    DEFF Research Database (Denmark)

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


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

  5. Reflecting reflection in supervision

    DEFF Research Database (Denmark)

    Lystbæk, Christian Tang

    Reflection has moved from the margins to the mainstream in supervision. Notions of reflection have become well established since the late 1980s. These notions have provided useful framing devices to help conceptualize some important processes in guidance and counseling. However, some applications...... of reflection, rehabilitate them in order to capture broader connotations or move to new ways of regarding reflection that are more in keeping with not only reflective but also emotive, normative and formative views on supervision. The paper presents a critical perspective on supervision that challenge...

  6. Uptake of 111In-labeled fully human monoclonal antibody TSP-A18 reflects transferrin receptor expression in normal organs and tissues of mice. (United States)

    Sugyo, Aya; Tsuji, Atsushi B; Sudo, Hitomi; Nomura, Fumiko; Satoh, Hirokazu; Koizumi, Mitsuru; Kurosawa, Gene; Kurosawa, Yoshikazu; Saga, Tsuneo


    Transferrin receptor (TfR) is an attractive molecule for targeted therapy of cancer. Various TfR-targeted therapeutic agents such as anti-TfR antibodies conjugated with anticancer agents have been developed. An antibody that recognizes both human and murine TfR is needed to predict the toxicity of antibody-based agents before clinical trials, there is no such antibody to date. In this study, a new fully human monoclonal antibody TSP-A18 that recognizes both human and murine TfR was developed and the correlation analysis of the radiolabeled antibody uptake and TfR expression in two murine strains was conducted. TSP-A18 was selected using extracellular portions of human and murine TfR from a human antibody library. The cross-reactivity of TSP-A18 with human and murine cells was confirmed by flow cytometry. Cell binding and competitive inhibition assays with [111In]TSP-A18 showed that TSP-A18 bound highly to TfR-expressing MIAPaCa-2 cells with high affinity. Biodistribution studies of [111In]TSP-A18 and [67Ga]citrate (a transferrin-mediated imaging probe) were conducted in C57BL/6J and BALB/c-nu/nu mice. [111In]TSP-A18 was accumulated highly in the spleen and bone containing marrow component of both strains, whereas high [67Ga]citrate uptake was only observed in bone containing marrow component and not in the spleen. Western blotting indicated the spleen showed the strongest TfR expression compared with other organs in both strains. There was significant correlation between [111In]TSP-A18 uptake and TfR protein expression in both strains, whereas there was significant correlation of [67Ga]citrate uptake with TfR expression only in C57BL/6J. These findings suggest that the difference in TfR expression between murine strains should be carefully considered when testing for the toxicity of anti-TfR antibody in mice and the uptake of anti-TfR antibody could reflect tissue TfR expression more accurately compared with that of transferrin-mediated imaging probe such as [67Ga]citrate.

  7. Get Enough Calcium (United States)

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

  8. Calcium carbonate overdose (United States)

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

  9. Calcium Balance in Chronic Kidney Disease. (United States)

    Hill Gallant, Kathleen M; Spiegel, David M


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

  10. Calcium paradox and calcium entry blockers

    NARCIS (Netherlands)

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


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

  11. The reflective learning continuum: reflecting on reflection


    Peltier, J; Hay, A.; Drago, W


    The importance of reflection to marketing educators is increasingly recognized. However, there is a lack of empirical research which considers reflection within the context of both the marketing and general business education literature. This paper describes the use of an instrument which can be used to measure four identified levels of a reflection hierarchy: habitual action, understanding, reflection and intensive reflection and two conditions for reflection: instructor to student interacti...

  12. Monitoring phenology of photosynthesis in temperate evergreen and mixed deciduous forests using the normalized difference vegetation index (NDVI) and the photochemical reflectance index (PRI) at leaf and canopy scales (United States)

    Wong, C. Y.; Arain, M. A.; Ensminger, I.


    Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which determines their phenology of high photosynthetic activity in the growing season and downregulation during the winter. Monitoring the timing of the transition between summer activity and winter downregulation in evergreens is difficult since this is a largely invisible process, unlike in deciduous trees that have a visible budding and a sequence of leaf unfolding in the spring and leaf abscission in the fall. The light-use efficiency (LUE) model estimates gross primary productivity (GPP) and may be parameterized using remotely sensed vegetation indices. Using spectral reflectance data, we derived the normalized difference vegetation index (NDVI), a measure of leaf "greenness", and the photochemical reflectance index (PRI), a proxy for chlorophyll:carotenoid ratios which is related to photosynthetic activity. To better understand the relationship between these vegetation indices and photosynthetic activity and to contrast this relationship between plant functional types, the phenology of NDVI, PRI and photosynthesis was monitored in an evergreen forest and a mixed deciduous forest at the leaf and canopy scale. Our data indicates that the LUE model can be parameterized by NDVI and PRI to track forest phenology. Differences in the sensitivity of PRI and NDVI will be discussed. These findings have implications to address the phenology of evergreen conifers by using PRI to complement NDVI in the LUE model, potentially improving model productivity estimates in northern hemisphere forests, that are dominated by conifers.

  13. Coronary Calcium Scan (United States)

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


    Directory of Open Access Journals (Sweden)

    N.I. Taibulatov


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

  15. Calcium source (image) (United States)

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

  16. Calcium and bones (image) (United States)

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

  17. Calcium hydroxide poisoning (United States)

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

  18. Calcium Pyrophosphate Deposition (CPPD) (United States)

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

  19. Calcium blood test (United States)

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

  20. The influence of environmental calcium concentrations on calcium flux, compensatory drinking and epithelial calcium channel expression in a freshwater cartilaginous fish. (United States)

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


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

  1. Reflective Writing

    DEFF Research Database (Denmark)

    Ahrenkiel Jørgensen, Andriette


    a contribution to the discussions about the role of reflection in design work and in learning situations at large. By engaging with the dialogic reflection, which is one of the four essential types of reflection, (the three others being descriptive writing, descriptive reflection and critical reflection...

  2. The distribution of free calcium ions in the cholesteatoma epithelium

    DEFF Research Database (Denmark)

    Svane-Knudsen, Viggo; Rasmussen, Gurli; Ottosen, Peter D


    The distribution of free calcium ions in normal skin and cholesteatoma epithelium was investigated using the oxalate precipitation method. In agreement with previous observations, we could demonstrate a calcium ion gradient in normal epidermis where the cells in stratum basale and spinosum reside...

  3. Astrocyte calcium signalling orchestrates neuronal synchronization in organotypic hippocampal slices (United States)

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


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

  4. Clarifying Normalization (United States)

    Carpenter, Donald A.


    Confusion exists among database textbooks as to the goal of normalization as well as to which normal form a designer should aspire. This article discusses such discrepancies with the intention of simplifying normalization for both teacher and student. This author's industry and classroom experiences indicate such simplification yields quicker…

  5. Cell saver autologous transfusion: metabolic consequences of washing blood with normal saline. (United States)

    Halpern, N A; Alicea, M; Seabrook, B; Spungen, A M; McElhinney, A J; Greenstein, R J


    To evaluate acid-base and electrolyte changes in high volume cell saver autologous blood transfusion when normal saline (0.9% NaCl) is used as the wash solution. Open-label study. Nine anesthetized and anticoagulated mongrel dogs underwent 15 cycles of cell saver autologous blood transfusion. Eight percent of the circulating blood volume (125 mL) was withdrawn, washed with normal saline, and retransfused for each cycle. Analyses of acid-base, electrolyte, and hematologic parameters were performed on both systemic and the washed blood. The washed blood had increased levels of sodium and chloride. There were decreased levels in pH, Pco2, total CO2 (bicarbonate), lactic acid, potassium, total and ionized calcium, magnesium, inorganic phosphorus, total protein, and albumin. Systemically, in the animals, by the end of the study, there were significant increases in the levels of chloride, inorganic phosphorus, hemoglobin, and hematocrit and significant decreases in the levels of pH, total CO2, total and ionized calcium, magnesium, total protein, and albumin. Acid-base, electrolyte, and hematologic changes occur when normal saline is used as the wash solution in high volume cell saver autologous blood transfusion. The washed blood with its elevation of sodium and chloride appears to reflect the constituents of the wash solution, normal saline. The depletion in the washed blood of PCO2, total CO2, potassium, total calcium, ionized calcium, magnesium, phosphorus, total protein, and albumin we feel is because of the absence of these electrolytes in the wash solution and their physical removal during salvaged blood separation and washing. The systemic acid-base and electrolyte changes primarily reflect the electrolyte pattern of the reinfused washed blood except for inorganic phosphorus. Inorganic phosphorus was maintained systemically, despite its wash out in the cell salvage process. This paradoxical finding may be caused by intracellular to extracellular inorganic

  6. Influência da direção de semeadura do milho nas variáveis reflectância e índice de vegetação verde normalizado Influence of the row direction of corn on the reflectance and green normalized difference vegetation index

    Directory of Open Access Journals (Sweden)

    Eduardo G. de Souza


    Full Text Available Com este trabalho, objetivou-se estudar a influência da direção de semeadura do milho (Zea Mays L. na sua reflectância na banda 550 nm (r550 e no Índice de Vegetação Verde da Diferença Normalizado - IVVDN, visando fornecer informações necessárias à viabilização de um sistema de aplicação localizada de nitrogênio (N em tempo real. O sistema de semeadura utilizado foi o direto, administrando-se os nutrientes de acordo com análise do solo e com uma taxa de N de 160 kg ha-1. As linhas de semeadura foram localizadas na direção Norte-Sul e Leste-Oeste. Conclui-se que o milho semeado na direção Leste-Oeste apresentou valores para reflectância r550 e índice de vegetação IVVDN menores e menos dependente da hora do dia que o milho semeado na direção Norte-Sul. O IVVDN mostrou-se mais apropriado para uso em sistemas de aplicação de fertilizantes a taxas variáveis em tempo real utilizando-se técnicas de sensoriamento remoto, por se mostrar menos sensível á direção de semeadura.The objective of this work was to study the influence of the row direction of corn (Zea mays on its spectral properties measured in the field, including the green normalized difference vegetation index (Green NDVI. Spectral properties of corn are known to be related to the nitrogen (N status of the corn and may form the basis for real-time site-specific rates of N application. Row direction effects on spectral properties may be substantial before canopy closure. If so, it will be necessary to account for these effects in order to accurately predict the N need of corn from spectral measurements. Corn was planted directly, with no tillage, in North-South (NS and East-West (EW oriented rows. Nitrogen was applied as ammonium nitrate at a rate of 160 kg N ha-1. Reflectance was measured with spectral radiometers placed 30 cm above individual plants. Reflectance and green NDVI were bly dependent on time of day for corn in NS rows, and much less so for corn

  7. Diagram of Calcium Movement in the Human Body (United States)


    This diagram shows the normal pathways of calcium movement in the body and indicates changes (green arrows) seen during preliminary space flight experiments. Calcium plays a central role because 1) it gives strength and structure to bone and 2) all types of cells require it to function normally. To better understand how and why weightlessness induces bone loss, astronauts have participated in a study of calcium kinetics -- that is, the movement of calcium through the body, including absorption from food, and its role in the formation and breakdown of bone.

  8. Substitutions in Calcium Aluminates and Calcium Aluminoferrites. (United States)


  9. Paclitaxel Induces Apoptosis in Breast Cancer Cells through Different Calcium—Regulating Mechanisms Depending on External Calcium Conditions

    Directory of Open Access Journals (Sweden)

    Zhi Pan


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

  10. Paclitaxel Induces Apoptosis in Breast Cancer Cells through Different Calcium—Regulating Mechanisms Depending on External Calcium Conditions (United States)

    Pan, Zhi; Avila, Andrew; Gollahon, Lauren


    Previously, we reported that endoplasmic reticulum calcium stores were a direct target for paclitaxel initiation of apoptosis. Furthermore, the actions of paclitaxel attenuated Bcl-2 resistance to apoptosis through endoplasmic reticulum-mediated calcium release. To better understand the calcium-regulated mechanisms of paclitaxel-induced apoptosis in breast cancer cells, we investigated the role of extracellular calcium, specifically; whether influx of extracellular calcium contributed to and/or was necessary for paclitaxel-induced apoptosis. Our results demonstrated that paclitaxel induced extracellular calcium influx. This mobilization of extracellular calcium contributed to subsequent cytosolic calcium elevation differently, depending on dosage. Under normal extracellular calcium conditions, high dose paclitaxel induced apoptosis-promoting calcium influx, which did not occur in calcium-free conditions. In the absence of extracellular calcium an “Enhanced Calcium Efflux” mechanism in which high dose paclitaxel stimulated calcium efflux immediately, leading to dramatic cytosolic calcium decrease, was observed. In the absence of extracellular calcium, high dose paclitaxel’s stimulatory effects on capacitative calcium entry and apoptosis could not be completely restored. Thus, normal extracellular calcium concentrations are critical for high dose paclitaxel-induced apoptosis. In contrast, low dose paclitaxel mirrored controls, indicating that it occurs independent of extracellular calcium. Thus, extracellular calcium conditions only affect efficacy of high dose paclitaxel-induced apoptosis. PMID:24549172

  11. Birkhoff normalization

    NARCIS (Netherlands)

    Broer, H.; Hoveijn, I.; Lunter, G.; Vegter, G.


    The Birkhoff normal form procedure is a widely used tool for approximating a Hamiltonian systems by a simpler one. This chapter starts out with an introduction to Hamiltonian mechanics, followed by an explanation of the Birkhoff normal form procedure. Finally we discuss several algorithms for

  12. Calcium channel blocker overdose (United States)

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

  13. Fenoprofen calcium overdose (United States)

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

  14. Differences between mouse and rat myocardial contractile responsiveness to calcium. (United States)

    Brooks, W W; Conrad, C H


    Genetically altered mice have become an increasingly important tool for the study of mechanisms of cardiac function, and therefore it is vital to characterize the basic contractile properties of the mouse heart. As a first approach to this goal, we first optimized perfusion conditions and characterized the effect of incremental left ventricular balloon inflation on end-diastolic, systolic and developed pressures in the isovolumically-contracting mouse heart. Under constant loading conditions, we determined developed pressure in response to changing perfusate calcium (1.25, 2.5, 3.75 and 5.0 mM) and perfusate temperature (30 and 37 degrees C). We then compared the intrinsic inotropic responsiveness to changes in extracellular calcium of left ventricular myocardium from mouse to that from the rat. In the baseline state (1.25 mM extracellular calcium; [Ca2+]o), both isometric contraction duration and normalized active force at the peak of the active force-length relationship (Lmax) were less in mouse than in rat myocardium. Under isotonic conditions, temporal parameters of shortening and the relative shortening were less in mouse vs rat myocardium. Increasing [Ca2+]o from 1.25 to 2.5 mM markedly increased active isometric force and rate of force development (+dF/dt) in the mouse. However, rat myocardium responded to a lesser extent. Under isotonic conditions, peak shortening and the rate of shortening also increased to a greater extent in mouse relative to rat myocardium. Increasing the bath calcium concentration to 5.0 mM increased isometric force and +dF/dt further in the rat but not the mouse, suggesting that two species operate at different points on the force vs [Ca2+]o relationship. We conclude that mouse myocardium exhibits increased sensitivity to changes in [Ca2+]o within the physiologic range in comparison to rat. These differences do not appear to be due to differences in loading conditions. The data suggest that differences in inotropic responsiveness to

  15. Calcium and Mitosis (United States)

    Hepler, P.


    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.

  16. Adaptive multispectral normalization system (United States)

    Lawler-Covell, Mary R.; West, Karen F.; Kiefer, Michael W.; Officer, Sarah M.; Price, Michael J.


    A multispectral normalization processing system has been developed to produce percent reflectance maps from multispectral imagery (MSI) in the .4 to 2.5 micron wavelength range. It is adaptive to multiple spatial resolutions, supporting resolutions in the .25 meter to 30 meter range. The normalization process takes advantage of known naturally occurring and man-made materials in the image to remove the effects of atmospheric haze and sensor gain contributions for each multispectral band. The output product is a percent reflectance map for each multispectral band. Although the normalization technique is well known, the MSI normalization system (MSINS) provides a simple, adaptive, robust graphical user interface for normalizing multispectral imagery from various sensor platforms. Over 130 different surface material spectra have been collected from reputable sources in literature and other spectral material libraries and installed in the MSINS Materials Spectral Information Database (MSID). The MSID has been designed to allow the addition of new material spectra into the system via a menu interface. A neural-net-based region grower has been developed to minimize user interaction and increase the robustness and repeatability of the normalization. New multispectral sensor platforms can be introduced into the system quickly via a menu interface. The current system was developed and tested using Landsat Thematic Mapper, Erim M7 Mapper, Positive Systems ADAR 5500, and ITRES casi multispectral imagery.

  17. Calcium en cardioplegie

    NARCIS (Netherlands)

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


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

  18. Treatment of fluorosed and white-spot human enamel with calcium sucrose phosphate in vitro. (United States)

    Den Besten, P; Giambro, N


    A number of treatments have been devised to improve the appearance of fluorosed enamel. However, many of these have been empirically based, and the success of the various treatment regimens have not been quantitated. In this study, the relative whiteness of normal, mildly fluorosed, moderately fluorosed, and carious white-spot lesions on extracted teeth was quantitated by light reflectance using a Minolta Chroma Meter. The color was again determined following a number of treatment regimens to assess the potential use of various agents in treating the enamel lesions. Treatment of the enamel with a 35% hydrogen peroxide gel resulted in a significantly increased whitening, which was not reduced by subsequent treatment (P calcium sucrose phosphate paste and placement in artificial saliva was most successful in returning both white-spot and fluorosed lesions to a normal color. SEM imaging of the calcium sucrose phosphate treated enamel suggests that this treatment filled the porous enamel, resulting in a normal light reflectance from the enamel.

  19. Computational study of a calcium release-activated calcium channel (United States)

    Talukdar, Keka; Shantappa, Anil


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

  20. Biochemistry of the normal dura mater of the human brain determination of water, sodium, potassium, calcium, phosphorus, magnesium, copper, iron, sulfur and nitrogen contents Estudo bioquímico da dura mater normal do cérebro humano: conteúdo de água, sódio, potássio, cálcio, fósforo, magnésio, cobre ferro, enxôfre e nitrogênio

    Directory of Open Access Journals (Sweden)

    Horacio M. Canelas


    Full Text Available The concentrations of water, sodium, potassium, calcium, phosphorus, magnesium, copper, iron, sulfur, and nitrogen were determined in samples of apparently normal dura mater removed from 18 subjects recently dead by craniocerebral trauma. The average concentrations expressed in dry weight were: water 79.55 g/100 g ± 2.52; sodium 1.63 mequiv/100 g ±0.27; potassium 3.68 mequiv/100 g ± 0.66; calcium 119.84 mg/100 g ± 107.40; phosphorus 68.2 mg/100 g ± 34.5; magnesium 0.61 mequiv/100 g ± 0.37; copper 249.8 /xg/100 g ± 109.4; iron 0.82 mg/100 g ± 0.28; sulfur 490.7 mg/100 g ± 22.5; nitrogen 3.33 g/100 g ± 0.17.Foram determinadas as concentrações de água, sódio, potássio, cálcio, fósforo, magnésio, cobre, ferro, enxôfre e nitrogênio de espécimes de dura máter aparentemente normal retirados de 18 indivíduos recentemente falecidos em conseqüência de traumatismo crânio-encefálico. As concentrações médias, expressas em peso seco, foram as seguintes: água 79,55 g/100 g ± 2,52; sódio 1,63 mequiv/100 g ± 0,27; potássio 3,68 mequiv/100 g ± 0,66; cálcio 119,84 mg/100 g ± 107,40; fósforo 68,2 mg/100 g ± 34,5; magnésio 0,61 mequiv/100 g ± 0,37; cobre 249,8 mg/100 ± 109,4; ferro 0,82 mg/100 g ± 0,28; enxôfre 490,7 mg/100 g ± 22,5; nitrogênio 3,33 g/100 g ± 0,17.

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

    Directory of Open Access Journals (Sweden)

    Yajin Liao


    Full Text Available 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.

  2. Calcium handling in Sparus auratus: effects of water and dietary calcium levels on mineral composition, cortisol and PTHrP levels.

    NARCIS (Netherlands)

    Abbink, W.; Bevelander, G.S.; Rotllant, J.; Canario, A.V.; Flik, G.


    Juvenile gilthead sea bream (Sparus auratus L.; 10-40 g body mass) were acclimatized in the laboratory to full strength (34 per thousand) or dilute (2.5 per thousand) seawater and fed normal, calcium-sufficient or calcium-deficient diet for nine weeks. Mean growth rate, whole-body calcium and

  3. Computational analysis of calcium signaling and membrane electrophysiology in cerebellar Purkinje neurons associated with ataxia

    Directory of Open Access Journals (Sweden)

    Brown Sherry-Ann


    Full Text Available Abstract Background Mutations in the smooth endoplasmic reticulum (sER calcium channel Inositol Trisphosphate Receptor type 1 (IP3R1 in humans with the motor function coordination disorders Spinocerebellar Ataxia Types 15 and 16 (SCA15/16 and in a corresponding mouse model, the IP3R1delta18/delta18 mice, lead to reduced IP3R1 levels. We posit that increasing IP3R1 sensitivity to IP3 in ataxias with reduced IP3R1 could restore normal calcium response. On the other hand, in mouse models of the human polyglutamine (polyQ ataxias, SCA2, and SCA3, the primary finding appears to be hyperactive IP3R1-mediated calcium release. It has been suggested that the polyQ SCA1 mice may also show hyperactive IP3R1. Yet, SCA1 mice show downregulated gene expression of IP3R1, Homer, metabotropic glutamate receptor (mGluR, smooth endoplasmic reticulum Ca-ATP-ase (SERCA, calbindin, parvalbumin, and other calcium signaling proteins. Results We create a computational model of pathological alterations in calcium signaling in cerebellar Purkinje neurons to investigate several forms of spinocerebellar ataxia associated with changes in the abundance, sensitivity, or activity of the calcium channel IP3R1. We find that increasing IP3R1 sensitivity to IP3 in computational models of SCA15/16 can restore normal calcium response if IP3R1 abundance is not too low. The studied range in IP3R1 levels reflects variability found in human and mouse ataxic models. Further, the required fold increases in sensitivity are within experimental ranges from experiments that use IP3R1 phosphorylation status to adjust its sensitivity to IP3. Results from our simulations of polyglutamine SCAs suggest that downregulation of some calcium signaling proteins may be partially compensatory. However, the downregulation of calcium buffer proteins observed in the SCA1 mice may contribute to pathology. Finally, our model suggests that the calcium-activated voltage-gated potassium channels may provide an

  4. Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture* (United States)

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


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

  5. Understanding the Biocompatibility of Sintered Calcium Phosphate with Ratio of [Ca]/[P] = 1.50

    Directory of Open Access Journals (Sweden)

    Feng-Lin Yen


    Full Text Available Biocompatibility of sintered calcium phosphate pellets with [Ca]/[P] = 1.50 was determined in this study. Calcium pyrophosphate (CPP phase formed on the sintered pellets immersed in a normal saline solution for 14 d at 37∘C. The intensities of hydroxyapatite (HA reflections in the X-ray diffraction (XRD patterns of the pellets were retrieved to as-sintered state. The pellet surface morphology shows that CPP crystallites were clearly present and make an amorphous calcium phosphate (ACP to discriminate against become to the area of slice join together. In addition, the intensities of the CPP reflections in the XRD patterns were the highest when the pellets were immersed for 28 d. When the CPP powders were extracted from the pellets after immersion in the solution for 14 d, the viability of 3T3 cells remained above 90% for culture times from 1 to 4 d. The pellet surface morphology observed using optical microscopy showed that the cells did not adhere to the bottom of the sintered pellets when cultured for 4 d; however, some CPP phase precipitates were formed, as confirmed by XRD. In consequence, the results suggest that the sintered HA powders are good materials for use in biomedical applications because of their good biocompatibility.

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

    NARCIS (Netherlands)

    Graveland, J.


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

  7. Quantifying Reflection

    DEFF Research Database (Denmark)

    Alcock, Gordon Lindsay


    This paper documents 1st semester student reflections on “learning to learn” in a team-based PBL environment with quantitative and qualitative student reflective feedback on the learning gains of 60 Architectural Technology and Construction Management students at VIA University College, Denmark....... It contrasts the students’ self-assessment in a range of ‘product’ skills such as Revit, Structural Design, Mathematics of construction, Technical Installations; as well as ‘process’ competencies such as ‘Working in a team’, Sharing knowledge, Maintaining a portfolio and Reflecting ON learning and FOR learning......´ These are all based on Blooms taxonomy and levels of competence and form a major part of individual student and group learning portfolios. Key Words :Project-Based learning, Reflective Portfolios, Self assessment, Defining learning gains, Developing learning strategies , Reflections on and for learning...

  8. Infinitary normalization

    NARCIS (Netherlands)

    J.W. Klop (Jan Willem); R. de Vrijer


    textabstractIn infinitary orthogonal first-order term rewriting the properties confluence (CR), Uniqueness of Normal forms (UN), Parallel Moves Lemma (PML) have been generalized to their infinitary versions CR-inf, UN-inf, PML-inf, and so on. Several relations between these properties have been

  9. Normal Coagulation (United States)


    PROTEINS, INHIBITORS, AND RECEPTORS History and Nomenclature Current knowledge of the components involved in the complex process of blood...specific, and it does not necessarily reflect the risk or severity of surgical bleeding. It is poorly reproducible, can be affected by aspirin ...epinephrine test response may be due to aspirin ingestion. This is the most frequently encountered abnormal collagen/epinephrine result as a single

  10. Reflection ciphers

    DEFF Research Database (Denmark)

    Boura, Christina; Canteaut, Anne; Knudsen, Lars Ramkilde


    study the necessary properties for this coupling permutation. Special care has to be taken of some related-key distinguishers since, in the context of reflection ciphers, they may provide attacks in the single-key setting.We then derive some criteria for constructing secure reflection ciphers...... and analyze the security properties of different families of coupling permutations. Finally, we concentrate on the case of reflection block ciphers and, as an illustration, we provide concrete examples of key schedules corresponding to several coupling permutations, which lead to new variants of the block...

  11. Calcium channel blocker poisoning

    Directory of Open Access Journals (Sweden)

    Miran Brvar


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

  12. Dietary supplementation with β-hydroxy-β-methylbutyrate calcium during the early postnatal period accelerates skeletal muscle fibre growth and maturity in intra-uterine growth-retarded and normal-birth-weight piglets. (United States)

    Wan, Haifeng; Zhu, Jiatao; Su, Guoqi; Liu, Yan; Hua, Lun; Hu, Liang; Wu, Caimei; Zhang, Ruinan; Zhou, Pan; Shen, Yong; Lin, Yan; Xu, Shengyu; Fang, Zhengfeng; Che, Lianqiang; Feng, Bin; Wu, De


    Intra-uterine growth restriction (IUGR) impairs postnatal growth and skeletal muscle development in neonatal infants. This study evaluated whether dietary β-hydroxy-β-methylbutyrate Ca (HMB-Ca) supplementation during the early postnatal period could improve muscle growth in IUGR neonates using piglets as a model. A total of twelve pairs of IUGR and normal-birth-weight (NBW) male piglets with average initial weights (1·85 (sem 0·36) and 2·51 (sem 0·39) kg, respectively) were randomly allotted to groups that received milk-based diets (CON) or milk-based diets supplemented with 800 mg/kg HMB-Ca (HMB) during days 7-28 after birth. Blood and longissimus dorsi (LD) samples were collected and analysed for plasma amino acid content, fibre morphology and the expression of genes related to muscle development. The results indicate that, regardless of diet, IUGR piglets had a significantly decreased average daily weight gain (ADG) compared with that of NBW piglets (Psupplementation markedly increased the type II fibre cross-sectional area and the mRNA expression of mammalian target of rapamycin (mTOR), insulin-like growth factor-1 and myosin heavy-chain isoform IIb in the LD of piglets (Psupplementation during the early postnatal period could improve skeletal muscle growth and maturity by accelerating fast-twitch glycolytic fibre development in piglets.

  13. Malware Normalization


    Christodorescu, Mihai; Kinder, Johannes; Jha, Somesh; Katzenbeisser, Stefan; Veith, Helmut


    Malware is code designed for a malicious purpose, such as obtaining root privilege on a host. A malware detector identifies malware and thus prevents it from adversely affecting a host. In order to evade detection by malware detectors, malware writers use various obfuscation techniques to transform their malware. There is strong evidence that commercial malware detectors are susceptible to these evasion tactics. In this paper, we describe the design and implementation of a malware normalizer ...

  14. Calcium-Induced calcium release during action potential firing in developing inner hair cells. (United States)

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


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

  15. Changes in total body calcium and diet of breeding house sparrows (United States)

    Krementz, D.G.; Ankney, C.D.


    We collected House Sparrows Passer domesticus around London, Ontario, estimated their total body calcium masses, food habits and egg production to test for the effects of endogenous calcium levels on control of clutch size. Before egg production began, calcium levels increased significantly and remained high through the end of egg laying, and then declined significantly after egg laying. We found no evidence that clutch size was related to endogenous calcium levels. Upon first ovulation, House Sparrows greatly increased consumption of calciferous materials such as snail shells, bird eggshells and calciferous grit. Their diet returned to normal after the final egg was ovulated. Daily calcium intake was sufficient to meet eggshell calcium needs.

  16. Normalizing Rejection. (United States)

    Conn, Vicki S; Zerwic, Julie; Jefferson, Urmeka; Anderson, Cindy M; Killion, Cheryl M; Smith, Carol E; Cohen, Marlene Z; Fahrenwald, Nancy L; Herrick, Linda; Topp, Robert; Benefield, Lazelle E; Loya, Julio


    Getting turned down for grant funding or having a manuscript rejected is an uncomfortable but not unusual occurrence during the course of a nurse researcher's professional life. Rejection can evoke an emotional response akin to the grieving process that can slow or even undermine productivity. Only by "normalizing" rejection, that is, by accepting it as an integral part of the scientific process, can researchers more quickly overcome negative emotions and instead use rejection to refine and advance their scientific programs. This article provides practical advice for coming to emotional terms with rejection and delineates methods for working constructively to address reviewer comments. © The Author(s) 2015.

  17. Acidosis and Urinary Calcium Excretion

    DEFF Research Database (Denmark)

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


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

  18. Calcium and bones (United States)

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

  19. Calcium D-saccharate

    DEFF Research Database (Denmark)

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


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

  20. Extracellular Calcium and Magnesium

    African Journals Online (AJOL)

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

  1. The salutary effect of dietary calcium on bone mass in a rat model of simulated weightlessness (United States)

    Bikle, D. D.; Globus, R.; Halloran, B. P.; Morey-Holton, E.


    Whether supplementation of dietary calcium reduces the differences in bone mass of unweighed limbs and normally weighted limbs, and whether parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (1,25(OH)2D) respond differently to dietary calcium in unweighted animals in comparison with pair-fed controls was studied. The hind limbs of rats were unweighted by a tail suspension method and diets containing 0.1% to 2.4% calcium. After 2 weeks serum calcium, phosphorus, PTH and 1,25(OH)2D intestinal calcium transport were determined and bone mass, ash weight, and calcium in the tibia, L-1 vertebra, and humerus were measured. No significant differences in body weights were observed among the various groups. Suspended rats maintained constant levels of serum calcium and phosphate over the wide range of dietary calcium. Serum PTH and 1,25(OH)2D and intestinal calcium transport fell as dietary calcium was increased. Bone calcium in the tibia and vertebra from suspended rats remained less than that from pair-fed control. It is suggested that although no striking difference between suspended and control animals was observed in response to dieteary calcium, increasing dietary calcium may reduce the negative impact of unloading on the calcium content of the unweighted bones. The salutary effect of high dietary calcium appears to be due to inhibition of bone resorption rather than to stimulation of bone formation.

  2. Reconstructing Normality

    DEFF Research Database (Denmark)

    Gildberg, Frederik Alkier; Bradley, Stephen K.; Fristed, Peter Billeskov


    Forensic psychiatry is an area of priority for the Danish Government. As the field expands, this calls for increased knowledge about mental health nursing practice, as this is part of the forensic psychiatry treatment offered. However, only sparse research exists in this area. The aim of this study...... was to investigate the characteristics of forensic mental health nursing staff interaction with forensic mental health inpatients and to explore how staff give meaning to these interactions. The project included 32 forensic mental health staff members, with over 307 hours of participant observations, 48 informal...... interviews, and seven semistructured interviews. The findings show that staff interaction is typified by the use of trust and relationship-enabling care, which is characterized by the establishment and maintenance of an informal, trusting relationship through a repeated reconstruction of normality...


    NARCIS (Netherlands)



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

  4. Reflective Learning

    African Journals Online (AJOL)


    students who used learning log and those who did not especially for the course Pschopharmacology, but the mean scores did not show a significant difference for the course Psychology of Gender. The reflective reports of the students also roughly indicated that the students developed positive attitudes towards using ...


    Indian Academy of Sciences (India)

    IAS Admin

    Resonance journal of science education. April 2015 Volume 20 Number 4. GENERALARTICLES ... Development of. Probability Theory. K B Athreya. Classroom. Tutorial on Phyloge- netic Inference –1. Felix Bast. 360. 346. 286. PERSONAL REFLECTIONS. 368 The Road to IISc. M L Munjal (Transcribed by Maneesh Kunte).


    Directory of Open Access Journals (Sweden)

    S A Vladimirov


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

  7. Calcium sensing in exocytosis

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Wu, Bingbing; Han, Weiping


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

  8. Normalizing difference in inclusive teaching. (United States)

    Baglieri, Susan; Knopf, Janice H


    Inclusion practices and special education can be transformed by using a disability studies perspective, which constructs differences as natural, acceptable, and ordinary. Although inclusion is a moral imperative in promoting social justice, some inclusive practices continue to marginalize students with disabilities. A truly inclusive school reflects a democratic philosophy whereby all students are valued, educators normalize difference through differentiated instruction, and the school culture reflects an ethic of caring and community.

  9. Calcium response to vitamin D supplementation

    Directory of Open Access Journals (Sweden)

    Francisco R. Spivacow


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

  10. Far infrared near normal specular reflectivity of Nix(SiO2)1-x (x = 1.0, 0.84, 0.75, 0.61, 0.54, 0.28) granular films

    KAUST Repository

    Massa, Néstor E.


    One of the current issues at the basis of the understanding of novel materials is the degree of the role played by spatial inhomogeneities due to subtle phase separations. To clarify this picture here we compare the plain glass network response of transition metal granular films with different metal fractions against what is known for conducting oxides. Films for Nix(SiO2)1-x (x = 1.0, 0.84, 0.75, 0.61, 0.54, 0.28) were studied by temperature dependent far infrared measurements. While for pure Ni the spectrum shows a flat high reflectivity, those for x ∼ 0.84 and ∼0.75 have a Drude component, vibrational modes mostly carrier screened, and a long tail that extents toward near infrared. This is associated with hopping electron conductivity and strong electron-phonon interactions. The relative reduction of the number of carriers in Ni0.75(SiO2)0.25 allows less screened phonon bands on the top of a continuum and a wide and overdamped oscillator at mid-infrared frequencies. Ni0.54(SiO2)0.46 and Ni0.28(SiO2)0.72 have well defined vibrational bands and a sharp threshold at ∼1450 cm-1. It is most remarkable that a distinctive resonant peak at ∼1250 cm-1 found for p-polarized angle dependent specular reflectivity. It originates in an electron cloud traced to electrons that are not able to overcome the metal-dielectric interface that, beating against the positive background, generates the electric dipole. Overall, we conclude that the spectra are analogous to those regularly found in conducting oxides where with a suitable percolating network polarons are formed. © 2009 Elsevier B.V. All rights reserved.

  11. Calcium's Role in Mechanotransduction during Muscle Development

    Directory of Open Access Journals (Sweden)

    Tatiana Benavides Damm


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

  12. Bone repair in calcium-deficient rats: comparison of xylitol+calcium carbonate with calcium carbonate, calcium lactate and calcium citrate on the repletion of calcium. (United States)

    Hämäläinen, M M


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

  13. Calcium and Magnesium Metabolism in Pre-Eclampsia. (United States)

    Udenze, I C; Arikawe, A P; Azinge, E C; Okusanya, B O; Ebuehi, O A


    Preeclampsia is a multisystem disorder associated with high maternal and perinatal mortality and morbidity. The cause of the disorder is largely unknown and its pathogenesis is complex and poorly understood. Calcium and magnesium are divalent ions which may have roles to play in the manifestations of the disease. An understanding of their metabolism in preeclampsia may aid our management of pregnant women who develop the disease. To determine the plasma and urinary concentrations of calcium, magnesium and parathyroid hormone in women with mild, severe preeclampsia and in normal pregnancy. This is was a case control study of fifty women with mild preeclampsia, fifty women with severe preeclampsia and fifty women with normal pregnancy as controls, drawn from The Antenatal Clinic at the Lagos University Teaching Hospital, Lagos, Nigeria. The women were consecutively recruited after signing an informed consent form. Ethical approval was obtained from the medical ethics committee of the hospital. The three groups of women were similar in their socio demographic characteristics. Plasma calcium was low in mild and severe preeclampsia compared to normal pregnancy controls (p=0.021). Urine calcium/creatinine ratio was lower in mild and severe preeclampsia compared to normal pregnancy controls (p= 0.030). Fractional excretion of calcium and levels of parathyroid hormone were similar across all three subgroups of women. Plasma magnesium was higher in mild and severe preeclampsia compared to normal pregnancy controls (p=0.011) and showed a positive correlation with plasma creatinine (r=0.48, p=0.045). Parathyroid hormone levels were similar across the study groups. Preeclampsia is associated with significant changes in calcium and magnesium metabolism. This study noted significant hypocalcaemia in mild and severe preeclampsia with significantly low urine calcium/creatinine levels. Calcium supplementation may have a place in patient's management. Hypermagnesemia was observed in

  14. Calcium – how and why?

    Indian Academy of Sciences (India)


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

  15. Calcium and Your Child (United States)

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

  16. Stoichiometry of Calcium Medicines (United States)

    Pinto, Gabriel


    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. Magnesium, calcium and cancer

    National Research Council Canada - National Science Library

    Anghileri, Leopoldo J


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

  18. Effects of elevated calcium on motor and exploratory activities of rats

    Directory of Open Access Journals (Sweden)

    Godinho A.F.


    Full Text Available The effects of serum and brain calcium concentration on rat behavior were tested by maintaining animals on either distilled water (N = 60 or water containing 1% calcium gluconate (N = 60 for 3 days. Animals that were maintained on high calcium drinking water presented increased serum calcium levels (control = 10.12 ± 0.46 vs calcium treated = 11.62 ± 0.51 µg/dl. Increase of brain calcium levels was not statistically significant. In the behavioral experiments each rat was used for only one test. Rats that were maintained on high calcium drinking water showed increased open-field behavior of ambulation (20.68% and rearing (64.57%. On the hole-board, calcium-supplemented animals showed increased head-dip (67% and head-dipping (126%, suggesting increased ambulatory and exploratory behavior. The time of social interaction was normal in animals maintained on drinking water containing added calcium. Rats supplemented with calcium and submitted to elevated plus-maze tests showed a normal status of anxiety and elevated locomotor activity. We conclude that elevated levels of calcium enhance motor and exploratory behavior of rats without inducing other behavioral alterations. These data suggest the need for a more detailed analysis of several current proposals for the use of calcium therapy in humans, for example in altered blood pressure states, bone mineral metabolism disorders in the elderly, hypocalcemic states, and athletic activities.

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

    NARCIS (Netherlands)

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


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

  20. Calcium in plant cells

    Directory of Open Access Journals (Sweden)

    V. V. Schwartau


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

  1. Calcium antagonists and the diabetic hypertensive patient

    DEFF Research Database (Denmark)

    Parving, H H; Rossing, P


    reduces albuminuria, delays the progression of nephropathy, and postpones renal insufficiency in diabetic nephropathy. Calcium antagonists and angiotensin converting enzyme inhibitors induce an acute increase in the glomerular filtration rate, renal plasma flow, and renal sodium excretion...... nephropathy alone and is rapidly rising. Increased arterial blood pressure is an early and common finding in incipient and overt diabetic nephropathy. Fluid and sodium retention with normal concentrations of active renin, angiotensin I and II, and aldosterone has been demonstrated in diabetic renal disease...

  2. [Microbial geochemical calcium cycle]. (United States)

    Zavarzin, G A


    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.

  3. Normalizing Catastrophe: Sustainability and Scientism (United States)

    Bonnett, Michael


    Making an adequate response to our deteriorating environmental situation is a matter of ever increasing urgency. It is argued that a central obstacle to achieving this is the way that scientism has become normalized in our thinking about environmental issues. This is taken to reflect on an underlying "metaphysics of mastery" that vitiates proper…

  4. Associations between calcium-phosphate metabolism and coronary artery calcification

    DEFF Research Database (Denmark)

    Grønhøj, Mette H; Gerke, Oke; Mickley, Hans


    BACKGROUND AND AIMS: High serum calcium-phosphate levels are associated with increased risk of cardiovascular disease (CVD) in patients with chronic kidney disease. Recent studies have demonstrated this relationship also in subjects with normal kidney function. Our aim was to examine whether......, were analysed for total calcium, phosphate, parathyroid hormone (PTH) and 25-hydroxyvitamin D (25(OH)D). CAC was measured by a non-contrast cardiac CT scan and categorised into four groups: 0, 1-99, 100-399, ≥400 Agatston units. The association of calcium-phosphate metabolism with CAC was evaluated...

  5. On Reflection

    DEFF Research Database (Denmark)

    Blasco, Maribel


    This article explores how the concept of reflexivity is used in intercultural education. Reflexivity is often presented as a key learning goal in acquiring intercultural competence (ICC). Yet, reflexivity can be defined in different ways, and take different forms across time and space, depending...... on the concepts of selfhood that prevail and how notions of difference are constructed. First, I discuss how the dominant usages of reflexivity in intercultural education reflect and reproduce a Cartesian view of the self that shapes how ICC is conceptualized and taught. I discuss three assumptions that this view...... in designing learning objectives in intercultural education and in devising ways to attain them. Greater attention is also needed in intercultural education to the ways in which selfhood, and hence also reflexivity and constructions of difference, differ across space and time....

  6. Calcium orthophosphates in dentistry. (United States)

    Dorozhkin, Sergey V


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

  7. Lead content in 70 brands of dietary calcium supplements. (United States)

    Bourgoin, B P; Evans, D R; Cornett, J R; Lingard, S M; Quattrone, A J


    OBJECTIVES. Elevated lead levels in calcium supplements may pose a health risk, particularly to children with milk intolerance who rely on these products to meet their calcium requirement. Earlier reports chiefly focused on the lead content in supplements derived from bonemeal and dolomite. This study undertook to determine the lead levels in the major forms of calcium supplements currently available. METHODS. The lead content was measured in 70 brands of calcium supplements grouped in the following five categories: dolomite, bonemeal, refined and natural source calcium carbonate, and calcium chelates. RESULTS. The lead levels measured in the supplements ranged from 0.03 microgram/g to 8.83 micrograms/g. Daily lead ingestion rates revealed that about 25% of the products exceeded the US Food and Drug Administration's "provisional" total tolerable daily intake of lead for children aged 6 years and under. Less than 20% of the supplements had "normalized" lead levels comparable to or lower than that reported for cow's milk. CONCLUSIONS. Children are the most sensitive to the low-level effects of lead. If calcium supplements are to provide an alternate source of calcium to some of these individuals, they should also deliver concomitant lead dosages no greater than those obtained from milk products themselves. PMID:8342726

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


    Hajnóczky, György; Csordás, György


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

  9. Gravimetric Determination of Calcium as Calcium Carbonate Hydrate. (United States)

    Henrickson, Charles H.; Robinson, Paul R.


    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)

  10. Nutritional aspects of calcium and vitamin D from infancy to adolescence. (United States)

    Saggese, G; Igli Baroncelli, G


    Calcium is an essential nutrient for normal growth and development. Growing individuals must be in positive calcium balance to satisfy their calcium needs. Calcium requirements are higher during infancy and adolescence than childhood and adulthood. The achievement of a higher calcium balance in infancy and adolescence is likely due to the increased serum 1,25-dihydroxyvitamin D concentration occurring during these periods. The main determinants of calcium balance in infancy are dietary calcium intake and vitamin D. In normal circumstances, breast milk and formulas supply sufficient amounts of calcium. In the post-natal life, the major sources of vitamin D are sunlight exposure and supplemented formulas; in fact, the amount of vitamin D in breast milk, cow's milk, and common foods is poor. Although sunlight exposure should be able to maintain adequate vitamin D stores, a supplement with 400 IU/day of vitamin D from birth to the second year of life is recommended to assure the prophylaxis of rickets in all breast-fed infants. A dose of 400 IU/day of vitamin D is safe and appropriate. During childhood and adolescence, currently recommended dietary allowances (RDA) for calcium might be augmented, as suggested by calcium balance studies. The higher amount of calcium intake may lead to achieve maximal peak bone mass. The main source of vitamin D in children and adolescents is the casual sunlight exposure; therefore, a sistematical vitamin D supplementation is not usually needed. The major sources of calcium are milk and dairy products. However, if calcium intake is reduced, an additional calcium intake to reach the RDA may be provided by calcium supplements.

  11. Children's Bone Health and Calcium (United States)

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

  12. Plasma phospholipid arachidonic acid content and calcium metabolism in idiopathic calcium nephrolithiasis. (United States)

    Baggio, B; Budakovic, A; Nassuato, M A; Vezzoli, G; Manzato, E; Luisetto, G; Zaninotto, M


    Reports of an increase in plasma and erythrocyte phospholipid arachidonic acid content and in urinary prostaglandin E2 (PGE2) excretion in patients with idiopathic calcium nephrolithiasis suggested their crucial role in the pathogenesis of hypercalciuria, a well-known risk factor for lithogenesis. To confirm this hypothesis, 15 healthy subjects and 20 nephrolithiasis patients were evaluated for plasma phospholipid polyunsaturated fatty acid content and PGE2 concentration, serum parathyroid hormone, 25 hydroxyvitamin D3, 1, 25-dihydroxyvitamin D3, and bone-specific alkaline phosphatase levels, as well as urinary excretion of calcium, biochemical markers of bone resorption (hydroxyproline and crossLaps), and intestinal calcium absorption. Furthermore, the effect of a 30-day fish-oil diet supplementation on the previously mentioned parameters was investigated in the patients. At baseline, patients compared with controls showed higher levels of plasma phospholipid arachidonic acid content (P = 0.002), PGE2 (P = 0.0004), serum 25-vitamin D3 (P = 0.001), and 1,25-vitamin D3 (P = 0.001), urinary excretion of calcium (P = 0.001), hydroxyproline (P = 0.007), and crossLaps (P = 0.019), as well as intestinal calcium absorption (P = 0.03 at 60 min). Fish oil supplementation induced a reduction in the plasma phospholipid arachidonic acid level (P < 0.0001), and except for serum concentrations of 25-vitamin D3, normalized baseline blood and urinary parameters, including intestinal calcium absorption. A close correlation between plasma PGE2 and serum 1,25-vitamin D3 (P = 0.004) and between phospholipid arachidonic acid and intestinal calcium absorption (P = 0.0002) and calciuria (P = 0.007) was observed, as well as between urine excretion of crossLaps and hydroxyproline (P < 0.0001), crossLaps and calcium (P < 0.0001), and hydroxyproline and calcium (P < 0.0001). These findings indicate that the phospholipid arachidonic acid content anomaly could represent the primary event

  13. From Milk to Bones, Moving Calcium Through the Body: Calcium Kinetics During Space Flight (United States)

    Smith, Scott; Bloomberg, Jacob; Lee, Angie (Technical Monitor)


    Did you know that when astronauts are in space, their height increases about two inches? This happens because the weightlessness of space allows the spine, usually compressed in Earth's gravity, to expand. While this change is relatively harmless, other more serious things can happen with extended stays in weightlessness, notably bone loss. From previous experiments, scientists have observed that astronauts lose bone mass at a rate of about one percent per month during flight. Scientists know that bone is a dynamic tissue - continually being made and repaired by specialized bone cells throughout life. Certain cells produce new bone, while other cells are responsible for removing and replacing old bone. Research on the mechanisms of bone metabolism and the effects of space flight on its formation and repair are part of the exciting studies that will be performed during STS-107. Calcium plays a central role because 1) it gives strength and structure to bone and 2) all types of cells require it to function normally. Ninety-nine percent of calcium in the body is stored in the skeleton. However, calcium may be released, or resorbed, from bone to provide for other tissues when you are not eating. To better understand how and why weightlessness induces bone loss, astronauts will participate in a study of calcium kinetics - that is, the movement of calcium through the body, including absorption from food, and its role in the formation and breakdown of bone.

  14. Stable prenucleation calcium carbonate clusters


    Gebauer, Denis; Völkel, Antje; Cölfen, Helmut


    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...

  15. Assay for calcium channels

    Energy Technology Data Exchange (ETDEWEB)

    Glossmann, H.; Ferry, D.R.


    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.

  16. Solar Imagery - Chromosphere - Calcium (United States)

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

  17. Calcium Signaling and Cardiac Arrhythmias. (United States)

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


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

  18. Calcium-sensing receptor in breast physiology and cancer

    Directory of Open Access Journals (Sweden)

    Wonnam Kim


    Full Text Available The calcium-sensing receptor (CaSR is expressed in normal breast epithelial cells and in breast cancer cells. During lactation, activation of the CaSR in mammary epithelial cells increases calcium transport into milk and inhibits parathyroid hormone-related protein (PTHrP secretion into milk and into the circulation. The ability to sense changes in extracellular calcium allows the lactating breast to actively participate in the regulation of systemic calcium and bone metabolism, and to coordinate calcium usage with calcium availability during milk production. Interestingly, as compared to normal breast cells, in breast cancer cells, the regulation of PTHrP secretion by the CaSR becomes rewired due to a switch in its G-protein usage such that activation of the CaSR increases instead of decreases PTHrP production. In normal cells the CaSR couples to Gi to inhibit cAMP and PTHrP production, whereas in breast cancer cells, it couples to Gs to stimulate cAMP and PTHrP production. Activation of the CaSR on breast cancer cells regulates breast cancer cell proliferation, death and migration, in part, by stimulating PTHrP production. In this article, we discuss the biology of the CaSR in the normal breast and in breast cancer, and review recent findings suggesting that the CaSR activates a nuclear pathway of PTHrP action that stimulates cellular proliferation and inhibits cell death, helping cancer cells adapt to elevated extracellular calcium levels. Understanding the diverse actions mediated by the CaSR may help us better understand lactation physiology, breast cancer progression and osteolytic bone metastases.

  19. The Plasma Membrane Calcium Pump (United States)

    Rasmussen, H.


    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.

  20. Calcium addition in straw gasification

    DEFF Research Database (Denmark)

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


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

  1. Impregnating Coal With Calcium Carbonate (United States)

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


    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.

  2. Effect of Potassium Citrate on Calcium Phosphate Stones in a Model of Hypercalciuria (United States)

    Asplin, John R.; Frick, Kevin K.; Granja, Ignacio; Culbertson, Christopher D.; Ng, Adeline; Grynpas, Marc D.; Bushinsky, David A.


    Potassium citrate is prescribed to decrease stone recurrence in patients with calcium nephrolithiasis. Citrate binds intestinal and urine calcium and increases urine pH. Citrate, metabolized to bicarbonate, should decrease calcium excretion by reducing bone resorption and increasing renal calcium reabsorption. However, citrate binding to intestinal calcium may increase absorption and renal excretion of both phosphate and oxalate. Thus, the effect of potassium citrate on urine calcium oxalate and calcium phosphate supersaturation and stone formation is complex and difficult to predict. To study the effects of potassium citrate on urine supersaturation and stone formation, we utilized 95th-generation inbred genetic hypercalciuric stone-forming rats. Rats were fed a fixed amount of a normal calcium (1.2%) diet supplemented with potassium citrate or potassium chloride (each 4 mmol/d) for 18 weeks. Urine was collected at 6, 12, and 18 weeks. At 18 weeks, stone formation was visualized by radiography. Urine citrate, phosphate, oxalate, and pH levels were higher and urine calcium level was lower in rats fed potassium citrate. Furthermore, calcium oxalate and calcium phosphate supersaturation were higher with potassium citrate; however, uric acid supersaturation was lower. Both groups had similar numbers of exclusively calcium phosphate stones. Thus, potassium citrate effectively raises urine citrate levels and lowers urine calcium levels; however, the increases in urine pH, oxalate, and phosphate levels lead to increased calcium oxalate and calcium phosphate supersaturation. Potassium citrate induces complex changes in urine chemistries and resultant supersaturation, which may not be beneficial in preventing calcium phosphate stone formation. PMID:25855777

  3. Assessment of coronary atherosclerosis by cardiac image: complementary amount of the calcium score to myocardial perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Vitola, Joao Vicente; Cerci, Rodrigo J.; Zapparoli, Marcello, E-mail: [Quanta Diagnostico Nuclear, Curitiba, PR (Brazil)


    Over the last decades we have witnessed significant advances on diagnostic tools and management of patients with or suspected cardiovascular disease, and consequently a significant reduction in mortality. Nevertheless, cardiovascular disease remains the leader cause of death in many countries, including Brazil. Identifying the high risk patient is important, so we can intensify prevention strategies. Non invasive diagnostic tools have been developed to identify the high risk patient in need of a myocardial revascularization, notably using myocardial scintigraphy. However, many clinicians still question, what is the best management for a patient with traditional risk factors, who has a positive treadmill test result and a completely normal myocardial scintigraphy? What is the literature showing in relation to the role of coronary calcium score for these patients? In this article we will reflect over these issues which are so frequently encountered in daily cardiology practice. (author)

  4. Calcium in milk and fermentation by yoghurt bacteria increase the resistance of rats to Salmonella infection.


    Bovee-Oudenhoven, I; Termont, D; Dekker, R. (Rudolf); Van der Meer, R


    Calcium in milk products stimulates gastric acid secretion and inhibits the cytolytic activity of intestinal contents. Based on these effects, it was hypothesised that calcium might lessen the severity of food borne intestinal infections. The possible differential effects of a low calcium milk and normal milk products (milk, acidified milk, and pasteurised yoghurt) on the resistance of rats to a salmonella infection was therefore studied. Rats were infected orally with Salmonella enteritidis ...

  5. Calcitonin secretion in normal human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Parthemore, J.G.; Deftos, L.J.


    A sensitive RIA for human calcitonin has been developed which can detect 1 to 2 pg hormone. This procedure permits the measurement of the low concentrations of calcitonin in the unextracted plasma of normal human subjects. In 55 normal adults, mean plasma calcitonin was 24 pg/ml with an SD of +-18 pg/ml, an SE of +-2 pg/ml, and a range of less than 10 to 75 pg/ml. There were no discernible age or sex differences in basal hormone concentration. Infusions of calcium, pentagastrin, and glucagon stimulated plasma calcitonin, whereas food and oral calcium did not. The stimulatory effect of pentagastrin was greater in males than in females. These data demonstrate that the low concentration of calcitonin in humans can be stimulated by several secretagogues and suggest that females may have decreased calcitonin reserve.

  6. A Reflective Look at Reflecting Teams (United States)

    Pender, Rebecca L.; Stinchfield, Tracy


    This article reviewed existing literature and research on the reflecting team process. There is a dearth of empirical research that explores the reflecting team process and the outcome of counseling that uses reflecting teams. Implications of using reflecting teams for counselors, counselor educators, and clients will be discussed. A call for…

  7. Intestinal hyperabsorption of calcium and low bone turnover in hypercalciuric postmenopausal osteoporosis. (United States)

    Odvina, Clarita V; Poindexter, John R; Peterson, Roy D; Zerwekh, Joseph E; Pak, Charles Y C


    Hypercalciuria of intestinal origin has been linked with bone loss in calcium nephrolithiasis and idiopathic osteoporosis. This retrospective data analysis was performed to explore potential pathogenetic link between intestinal hyperabsorption of calcium and postmenopausal osteoporosis. Data were retrieved from postmenopausal women who were evaluated for osteoporosis or osteopenia at the Mineral Metabolism Clinic of UT Southwestern Medical Center. A total of 319 patients underwent the test of calciuric response to oral calcium load to obtain an indirect measure of intestinal calcium absorption. Serum and urinary biochemistry and L2-L4 bone mineral density (BMD) were compared between five quintiles of calciuric response. There was a statistically significant trend toward a rise in 24-h urinary calcium and a decrease in urinary deoxypyridinoline (DPD) and BMD, with increasing order of quintiles. The presentation of those in the 1st quintile was consistent with vitamin D insufficiency or deficiency, with impaired calcium absorption, secondary hyperparathyroidism, and stimulated bone turnover (high normal urinary DPD). In contrast, patients in the 5th quintile displayed a picture of absorptive hypercalciuria of stone disease, with intestinal hyperabsorption of calcium, high or high normal urinary calcium and suppressed bone turnover (low or low normal urinary DPD). Thus, the assessment of intestinal calcium absorption in a seemingly homogeneous group of postmenopausal women with osteoporosis or osteopenia revealed a spectrum of calciuric response whose extremes may represent two physiologically distinct subtypes that have important diagnostic and therapeutic implications.

  8. Testing Urey's carbonate-silicate cycle using the calcium isotopic composition of sedimentary carbonates (United States)

    Blättler, Clara L.; Higgins, John A.


    Carbonate minerals constitute a major component of the sedimentary geological record and an archive of a fraction of the carbon and calcium cycled through the Earth's surface reservoirs for over three billion years. For calcium, carbonate minerals constitute the ultimate sink for almost all calcium liberated during continental and submarine weathering of silicate minerals. This study presents >500 stable isotope ratios of calcium in Precambrian carbonate sediments, both limestones and dolomites, in an attempt to characterize the isotope mass balance of the sedimentary carbonate reservoir through time. The mean of the dataset is indistinguishable from estimates of the calcium isotope ratio of bulk silicate Earth, consistent with the Urey cycle being the dominant mechanism exchanging calcium among surface reservoirs. The variability in bulk sediment calcium isotope ratios within each geological unit does not reflect changes in the global calcium cycle, but rather highlights the importance of local mineralogical and/or diagenetic effects in the carbonate record. This dataset demonstrates the potential for calcium isotope ratios to help assess these local effects, such as the former presence of aragonite, even in rocks with a history of neomorphism and recrystallization. Additionally, 29 calcium isotope measurements are presented from ODP (Ocean Drilling Program) Site 801 that contribute to the characterization of altered oceanic crust as an additional sink for calcium, and whose distinct isotopic signature places a limit on the importance of this subduction flux over Earth history.

  9. Quantitative observation on teeth during calcium deprivation in rats. (United States)

    Rasmussen, P


    Adult female rats were subjected to severe calcium deprivation by feeding them a calcium-deficient diet containing oxalate (Group A). Furthermore, pregnant and lactating animals were subjected to the same diet (Group B). The mandibular teeth were collected for ash determination and for linear measurements. The ash content of the growing incisors was only slightly reduced in Group A, while the reduction in Group B was 27%. Linear measurements demonstrated that the outer dimensions of the incisors were not affected by the calcium-depriving regimen in either group, while the inner dimensions (pulp cavity) were considerably increased in Group B due to reduced thickness of the dentin mantle. The daily dentin apposition in Group A did not deviate much from the control values, while in Group B it was severely reduced. The thickness of incisor enamel was unaffected by the calcium-depriving regimen. The ash content of the molars was normal in Group A, but slightly reduced in Group B.

  10. Calcium signaling in taste cells. (United States)

    Medler, Kathryn F


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

  11. T-type calcium channel: a privileged gate for calcium entry and control of adrenal steroidogenesis

    Directory of Open Access Journals (Sweden)

    Michel Florian Rossier


    Full Text Available 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 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


    Barton, J.


    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.

  13. Models of calcium signalling

    CERN Document Server

    Dupont, Geneviève; Kirk, Vivien; Sneyd, James


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

  14. Elemental calcium intake associated with calcium acetate/calcium carbonate in the treatment of hyperphosphatemia. (United States)

    Wilson, Rosamund J; Copley, J Brian


    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.

  15. Comparative Analysis of Spontaneous and Stimulus-Evoked Calcium Transients in Proliferating and Differentiating Human Midbrain-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Torben Johansen


    Full Text Available Spontaneous cytosolic calcium transients and oscillations have been reported in various tissues of nonhuman and human origin but not in human midbrain-derived stem cells. Using confocal microfluorimetry, we studied spontaneous calcium transients and calcium-regulating mechanisms in a human ventral mesencephalic stem cell line undergoing proliferation and neuronal differentiation. Spontaneous calcium transients were detected in a large fraction of both proliferating (>50% and differentiating (>55% cells. We provide evidence for the existence of intracellular calcium stores that respond to muscarinic activation of the cells, having sensitivity for ryanodine and thapsigargin possibly reflecting IP3 receptor activity and the presence of ryanodine receptors and calcium ATPase pumps. The observed calcium transient activity potentially supports the existence of a sodium-calcium antiporter and the existence of calcium influx induced by depletion of calcium stores. We conclude that the cells have developed the most important mechanisms governing cytosolic calcium homeostasis. This is the first comparative report of spontaneous calcium transients in proliferating and differentiating human midbrain-derived stem cells that provides evidence for the mechanisms that are likely to be involved. We propose that the observed spontaneous calcium transients may contribute to mechanisms involved in cell proliferation, phenotypic differentiation, and general cell maturation.

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


    Bizzozero, Julien; Scrivener, Karen


    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 ...

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


    Verch, Andreas; Antonietti, Markus; Cölfen, Helmut


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

  18. Fast calcium wave propagation mediated by electrically conducted excitation and boosted by CICR

    NARCIS (Netherlands)

    Kusters, J.M.A.M.; Meerwijk, W.P. van; Ypey, D.L.; Theuvenet, A.P.R.; Gielen, C.C.A.M.


    We have investigated synchronization and propagation of calcium oscillations, mediated by gap junctional excitation transmission. For that purpose we used an experimentally based model of normal rat kidney (NRK) cells, electrically coupled in a one-dimensional configuration (linear strand).

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

    National Research Council Canada - National Science Library

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


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

  20. On the growth of calcium tartrate tetrahydrate single crystals

    Indian Academy of Sciences (India)


    tartaric acid content of the gel is completely exhausted partly through the formation of calcium tartrate crystals and partly through the demonstrable loss of tartaric acid to the solution at the top in the gel region close to the super- natant liquid. Normally, many small crystals grow in the gel medium and only a few of them are ...

  1. Distal Renal Tubular Acidosis and Calcium Nephrolithiasis (United States)

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


    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.

  2. Physiological studies in heterozygous calcium sensing receptor (CaSR gene-ablated mice confirm that the CaSR regulates calcitonin release in vivo

    Directory of Open Access Journals (Sweden)

    Kovacs Christopher S


    Full Text Available Abstract Background The calcium sensing receptor (CaSR regulates serum calcium by suppressing secretion of parathyroid hormone; it also regulates renal tubular calcium excretion. Inactivating mutations of CaSR raise serum calcium and reduce urine calcium excretion. Thyroid C-cells (which make calcitonin express CaSR and may, therefore, be regulated by it. Since calcium stimulates release of calcitonin, the higher blood calcium caused by inactivation of CaSR should increase serum calcitonin, unless CaSR mutations alter the responsiveness of calcitonin to calcium. To demonstrate regulatory effects of CaSR on calcitonin release, we studied calcitonin responsiveness to calcium in normal and CaSR heterozygous-ablated (Casr+/- mice. Casr+/- mice have hypercalcemia and hypocalciuria, and live normal life spans. Each mouse received either 500 μl of normal saline or one of two doses of elemental calcium (500 μmol/kg or 5 mmol/kg by intraperitoneal injection. Ionized calcium was measured at baseline and 10 minutes, and serum calcitonin was measured on the 10 minute sample. Results At baseline, Casr+/- mice had a higher blood calcium, and in response to the two doses of elemental calcium, had greater increments and peak levels of ionized calcium than their wild type littermates. Despite significantly higher ionized calcium levels, the calcitonin levels of Casr+/- mice were consistently lower than wild type at any ionized calcium level, indicating that the dose-response curve of calcitonin to increases in ionized calcium had been significantly blunted or shifted to the right in Casr+/- mice. Conclusions These results confirm that the CaSR is a physiological regulator of calcitonin; therefore, in response to increases in ionized calcium, the CaSR inhibits parathyroid hormone secretion and stimulates calcitonin secretion.


    The reflection of electromagnetic waves normally incident on the wavefronts of a semi-infinite standing sound wave is discussed. By analogy with the...with the sound frequency. An experiment is described in which the Bragg reflection of 3 cm electromagnetic waves from a standing sound wave beneath a water surface is observed.

  4. Osteoporosis, calcium and physical activity.


    Martin, A. D.; Houston, C S


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

  5. Testing for normality

    CERN Document Server

    Thode, Henry C


    Describes the selection, design, theory, and application of tests for normality. Covers robust estimation, test power, and univariate and multivariate normality. Contains tests ofr multivariate normality and coordinate-dependent and invariant approaches.

  6. Challenging Narcissus, or Reflecting on Reflecting. (United States)

    Achilles, C. M.

    The concept of reflective practice and teaching people to be reflective practitioners is examined. The document begins with a look at professional knowledge according to three prominent professionals in the educational administration field: Schon, Schein, and Achilles. "Reflective" strategies that could be incorporated into courses and…

  7. Laser Sintered Calcium Phosphate Bone

    National Research Council Canada - National Science Library

    Vail, Neil


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

  8. Urine risk factors in children with calcium kidney stones and their siblings. (United States)

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


    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-h 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.

  9. 21 CFR 73.1070 - Calcium carbonate. (United States)


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

  10. 21 CFR 184.1191 - Calcium carbonate. (United States)


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

  11. Calcium signalling: fishing out molecules of mitochondrial calcium transport. (United States)

    Hajnóczky, György; Csordás, György


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

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

    DEFF Research Database (Denmark)

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


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

  13. The Normal Distribution Some Roles of Normality

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 7. The Normal Distribution Some Roles of Normality. S Ramasubramanian. Series Article Volume 2 Issue 7 July 1997 pp 27-37. Fulltext. Click here to view fulltext PDF. Permanent link: ...

  14. The Normal Distribution From Binomial to Normal

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 6. The Normal Distribution From Binomial to Normal. S Ramasubramanian. Series Article Volume 2 Issue ... Author Affiliations. S Ramasubramanian1. Statistics & Mathematics Unit, Indian Statistical Institute, RVCE Post, Bangalore 560 059, India.

  15. Oxypurines, protein, glucose and the functional state of blood vasculature are markers of renal calcium stone-forming processes? Observations in men with idiopathic recurrent calcium urolithiasis. (United States)

    Manoharan, Mahimaidos; Schwille, Paul O


    In idiopathic calcium urolithiasis the relationships between oxypurines, accompanying proteins and glucose in urine and plasma, and the associated metabolic activity (MA) are unknown. To establish whether MA is related to these parameters and to calcium oxalate crystallization, or whether it reflects a reaction of metabolism to systemic insults was the major goal of the work. One hundred fifty one males were studied in three trials: trial 1 (n=130 patients) and trial 2 (n=24 patients) were cross-sectional; trial 3 included 11 patients and 14 controls). Mean age was 46 years (trials 1 and 2) and 29 years (trial 3). In trial 1 the stratification was based on the median urinary oxypurine excretion, in trial 2 on the median plasma oxypurine concentration (below or above: Low and High subgroups). No dietary restrictions were imposed, but standardized ambulatory laboratory testing was carried out. MA was quantitated by a score. Established analytical methods were used, except for oxypurine measurement which was done by high performance liquid chromatography. Patients with kidney stones tended to be overweight (body mass index >25 kg/(m)2) and to have fasting hyperglycemia. In trial 1 severe oxypurinuria, and especially severe xanthinuria, was associated with an increase in urinary pH, creatinine clearance, proteins, uric acid, malonedialdehyde (indicator of lipid peroxidation), systolic blood pressure, and with a decrease in plasma uric acid (synonymous with a decrease of antioxidant capacity). Tubular reabsorption of proteins and stone-forming substances was diminished but MA remained unchanged despite slightly increased calcium oxalate crystal growth. In trial 2 high adenosine and xanthine coincided with elevated systolic and diastolic blood pressure, high uric acid with high urinary malonedialdehyde, high summed oxypurines minus uric acid with an increase of diastolic blood pressure, glycemia and MA; urinary nitrate (indicator of systemic vasodilation) was unchanged

  16. Seismic reflection and refraction methods

    Digital Repository Service at National Institute of Oceanography (India)

    Chaubey, A.K.

    , reflection method is a very sophisticated version of the echosounding used in submarines, ships, and radar systems. Whereas, in seismic refraction method, principal portion of the wave-path is along the interface between the two layers and hence... into electrical signals, which are recorded digitally. The Ocean Bottom Seismometers 221 (OBS) are normally designed to record the earth motion under oceans and lakes from air-gun seismic sources. The air gun array is towed behind a ship usually at a...

  17. Update on normal tension glaucoma

    Directory of Open Access Journals (Sweden)

    Jyotiranjan Mallick


    Full Text Available Normal tension glaucoma (NTG is labelled when typical glaucomatous disc changes, visual field defects and open anterior chamber angles are associated with intraocular pressure (IOP constantly below 21 mmHg. Chronic low vascular perfusion, Raynaud's phenomenon, migraine, nocturnal systemic hypotension and over-treated systemic hypertension are the main causes of normal tension glaucoma. Goldmann applanation tonometry, gonioscopy, slit lamp biomicroscopy, optical coherence tomography and visual field analysis are the main tools of investigation for the diagnosis of NTG. Management follows the same principles of treatment for other chronic glaucomas: To reduce IOP by a substantial amount, sufficient to prevent disabling visual loss. Treatment is generally aimed to lower IOP by 30% from pre-existing levels to 12-14 mmHg. Betaxolol, brimonidine, prostaglandin analogues, trabeculectomy (in refractory cases, systemic calcium channel blockers (such as nifedipine and 24-hour monitoring of blood pressure are considered in the management of NTG. The present review summarises risk factors, causes, pathogenesis, diagnosis and management of NTG.

  18. Calcium, vitamin D, and your bones (United States)

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

  19. Calcium Supplements: Do Men Need Them Too? (United States)

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

  20. Stable prenucleation calcium carbonate clusters. (United States)

    Gebauer, Denis; Völkel, Antje; Cölfen, Helmut


    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.

  1. Effect of oral drenching with zinc oxide or synthetic zeolite A on total blood calcium in dairy cows

    DEFF Research Database (Denmark)

    Jørgensen, R J; Hansen, T; Jensen, M L


    values. Oral drenching with a single dose of zinc oxide of 100 mg/kg of body weight as well as with zeolite in doses of 500 g of zeolite/cow twice a day for 2.5 d was reflected in serum calcium levels. In the group given zeolite A, there was a depression in evening values of total serum calcium although...

  2. Layered magnets: polarized neutron reflection studies

    Energy Technology Data Exchange (ETDEWEB)

    Zabel, H.; Schreyer, A. [Ruhr-Univ. Bochum, Lehrstuhl fuer Experimentalphysik/Festkoerperphysik, Bochum (Germany)


    Neutron reflectivity measurements from extended surfaces, thin films and superlattices provide information on the chemical profile parallel to the film normal, including film thicknesses, average composition and interfacial roughness parameters. Reflectivity measurements with polarized neutrons are particularly powerful for analyzing the magnetic density profiles in thin films and superlattices in addition to chemical profiles. The basic theory of polarized neutron reflectivity is provided, followed by some examples and more recent applications concerning polarized neutron reflectivity studies from exchange coupled Fe/Cr superlattices. (author) 5 figs., 13 refs.

  3. In vivo impact of presynaptic calcium channel dysfunction on motor axons in episodic ataxia type 2. (United States)

    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


    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 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.

  4. Fluorescence measurement of calcium transients in perfused rabbit heart using rhod 2. (United States)

    Del Nido, P J; Glynn, P; Buenaventura, P; Salama, G; Koretsky, A P


    Surface fluorescence spectroscopy of the beating heart to measure cytosolic calcium has been limited by the need to use ultraviolet excitation light for many of the commonly used calcium indicators. Ultraviolet light in the heart produces a high level of background fluorescence and is highly absorbed, limiting tissue penetration. Visible wave-length fluorescence dyes such as rhod 2 are available; however, the lack of spectral shift with calcium binding precludes the use of ratio techniques to account for changes in cytosolic dye concentration. We have developed a method for in vivo quantitation of cytosolic rhod 2 concentration that in conjunction with calcium-dependent fluorescence measurements permits estimation of cytosolic calcium levels in perfused rabbit hearts. Reflective absorbance of excitation light by rhod 2 loaded into myocardium was used as an index of dye concentration and the ratio of fluorescence intensity to absorbance as a measure of cytosolic calcium concentration. Endothelial cell loading of rhod 2 was found to be minimal (calcium was measured in vitro to be 500 nM, and this value increased to 710 nM in the presence of 0.5 mM myoglobin. On the basis of this value and in vivo fluorescence measurements, cytosolic calcium concentration in the rabbit heart was found to be 229 +/- 90 nM at end diastole and 930 +/- 130 nM at peak systole, with peak fluorescence preceding peak ventricular pressure by approximately 40 ms. This technique should facilitate detailed analysis of calcium transients from the whole heart.

  5. Optical based tactile shear and normal load sensor

    Energy Technology Data Exchange (ETDEWEB)

    Salisbury, Curt Michael


    Various technologies described herein pertain to a tactile sensor that senses normal load and/or shear load. The tactile sensor includes a first layer and an optically transparent layer bonded together. At least a portion of the first layer is made of optically reflective material. The optically transparent layer is made of resilient material (e.g., clear silicone rubber). The tactile sensor includes light emitter/light detector pair(s), which respectively detect either normal load or shear load. Light emitter(s) emit light that traverses through the optically transparent layer and reflects off optically reflective material of the first layer, and light detector(s) detect and measure intensity of reflected light. When a normal load is applied, the optically transparent layer compresses, causing a change in reflected light intensity. When shear load is applied, a boundary between optically reflective material and optically absorptive material is laterally displaced, causing a change in reflected light intensity.

  6. Renal control of calcium, phosphate, and magnesium homeostasis. (United States)

    Blaine, Judith; Chonchol, Michel; Levi, Moshe


    Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys. Copyright © 2015 by the American Society of Nephrology.

  7. Calcium metabolism & hypercalcemia in adults. (United States)

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


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

  8. Hybrid calcium phosphate coatings for implants (United States)

    Malchikhina, Alena I.; Shesterikov, Evgeny V.; Bolbasov, Evgeny N.; Ignatov, Viktor P.; Tverdokhlebov, Sergei I.


    Monophasic biomaterials cannot provide all the necessary functions of bones or other calcined tissues. It is necessary to create for cancer patients the multiphase materials with the structure and composition simulating the natural bone. Such materials are classified as hybrid, obtained by a combination of chemically different components. The paper presents the physical, chemical and biological studies of coatings produced by hybrid technologies (HT), which combine primer layer and calcium phosphate (CaP) coating. The first HT type combines the method of vacuum arc titanium primer layer deposition on a stainless steel substrate with the following micro-arc oxidation (MAO) in phosphoric acid solution with addition of calcium compounds to achieve high supersaturated state. MAO CaP coatings feature high porosity (2-8%, pore size 5-7 µm) and surface morphology with the thickness greater than 5 µm. The thickness of Ti primer layer is 5-40 µm. Amorphous MAO CaP coating micro-hardness was measured at maximum normal load Fmax = 300 mN. It was 3.1 ± 0.8 GPa, surface layer elasticity modulus E = 110 ± 20 GPa, roughness Ra = 0.9 ± 0.1 µm, Rz = 7.5 ± 0.2 µm, which is less than the titanium primer layer roughness. Hybrid MAO CaP coating is biocompatible, able to form calcium phosphates from supersaturated body fluid (SBF) solution and also stimulates osteoinduction processes. The second HT type includes the oxide layer formation by thermal oxidation and then CaP target radio frequency magnetron sputtering (RFMS). Oxide-RFMS CaP coating is a thin dense coating with good adhesion to the substrate material, which can be used for metal implants. The RFMS CaP coating has thickness 1.6 ± 0.1 µm and consists of main target elements calcium and phosphorus and Ca/P ratio 2.4. The second HT type can form calcium phosphates from SBF solution. In vivo study shows that hybrid RFMS CaP coating is biocompatible and produces fibrointegration processes.

  9. Adaptations in Maternofetal Calcium Transport in Relation to Placental Size and Fetal Sex in Mice

    Directory of Open Access Journals (Sweden)

    Christina E. Hayward


    Full Text Available Appropriate placental transport of calcium is essential for normal fetal skeletal mineralization. In fetal growth restriction (FGR, the failure of a fetus to achieve its growth potential, a number of placental nutrient transport systems show reduced activity but, in the case of calcium, placental transport is increased. In a genetic mouse model of FGR this increase, or adaptation, maintains appropriate fetal calcium content, relative to the size of the fetus, despite a small, dysfunctional placenta. It is unknown whether such an adaptation is also apparent in small, but normally functioning placentas. We tested the hypothesis that calcium transfer would be up-regulated in the lightest vs. heaviest placentas in the same C57Bl/6J wild-type (WT mouse litter. Since lightest placentas are often from females, we also assessed whether fetal sex influenced placental calcium transfer. Placentas and fetuses were collected at embryonic day (E16.5 and 18.5; the lightest and heaviest placentas, and female and male fetuses, were identified. Unidirectional maternofetal calcium clearance (CaKmf was assessed following 45Ca administration to the dam and subsequent radiolabel counts within the fetuses. Placental expression of calcium pathway components was measured by Western blot. Data (median are lightest placenta expressed as percentage of the heaviest within a litter and analyzed by Wilcoxon signed-rank test. In WT mice having normally grown fetuses, CaKmf, per gram placenta near term, in the lightest placentas was increased (126%; P < 0.05 in association with reduced fetal calcium accretion earlier in gestation (92%; P < 0.05, that was subsequently normalized near term. Increased placental expression of calbindin-D9K, an important calcium binding protein, was observed in the lightest placentas near term (122%; P < 0.01. There was no difference in fetal calcium accretion between male and female littermates but a trend toward higher CaKmf in females (P = 0

  10. Calcium and Calcium Supplements: Achieving the Right Balance (United States)

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

  11. Calcium carbonate and calcium sulfate in Martian meteorite EETA79001 (United States)

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


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

  12. The Normal Distribution

    Indian Academy of Sciences (India)

    The Normal Distribution. 2. Some Roles of Normality. S Ramasubramanian. The computational aid of part 1 of this series turns out to be a basic feature of nature, thanks to the central limit theorem. The role of normal distribu- tion in statistics, velocity distribution of an ideal gas, and the phenomenon of Brownian motion is ...

  13. Combined EUV reflectance and X-ray reflectivity data analysis of periodic multilayer structures

    NARCIS (Netherlands)

    Yakunin, S. N.; Makhotkin, I. A.; K. V. Nikolaev,; van de Kruijs, R. W. E.; Chuev, M. A.; F. Bijkerk,


    We present a way to analyze the chemical composition of periodical multilayer structures using the simultaneous analysis of grazing incidence hard X-Ray reflectivity (GIXR) and normal incidence extreme ultraviolet reflectance (EUVR). This allows to combine the high sensitivity of GIXR data to layer

  14. Confocal microscope is able to detect calcium metabolic in neuronal infection by toxoplasma gondii (United States)

    Sensusiati, A. D.; Priya, T. K. S.; Dachlan, Y. P.


    Calcium metabolism plays a very important role in neurons infected by Toxoplasma. Detection of change of calcium metabolism of neuron infected by Toxoplasma and Toxoplasma requires the calculation both quantitative and qualitative method. Confocal microscope has the ability to capture the wave of the fluorescent emission of the fluorescent dyes used in the measurement of cell calcium. The purpose of this study was to prove the difference in calcium changes between infected and uninfected neurons using confocal microscopy. Neuronal culture of human-skin-derived neural stem cell were divided into 6 groups, consisting 3 uninfected groups and 3 infected groups. Among the 3 groups were 2 hours, 24 hours and 48 hours. The neuron Toxoplasma gondii ratio was 1:5. Observation of intracellular calcium of neuron and tachyzoite, evidence of necrosis, apoptosis and the expression of Hsp 70 of neuron were examined by confocal microscope. The normality of the data was analysed by Kolmogorov-Smirnov Test, differentiation test was checked by t2 Test, and ANOVAs, for correlation test was done by Pearson Correlation Test. The calcium intensity of cytosolic neuron and T. gondii was significantly different from control groups (p<0.05). There was also significant correlation between calcium intensity with the evidence of necrosis and Hsp70 expression at 2 hours after infection. Apoptosis and necrosis were simultaneously shown with calcium contribution in this study. Confocal microscopy can be used to measure calcium changes in infected and uninfected neurons both in quantitatively and qualitatively.

  15. A model of calcium homeostasis in the rat. (United States)

    Granjon, David; Bonny, Olivier; Edwards, Aurélie


    We developed a model of calcium homeostasis in the rat to better understand the impact of dysfunctions such as primary hyperparathyroidism and vitamin D deficiency on calcium balance. The model accounts for the regulation of calcium intestinal uptake, bone resorption, and renal reabsorption by parathyroid hormone (PTH), vitamin D 3 , and Ca 2+ itself. It is the first such model to incorporate recent findings regarding the role of the calcium-sensing receptor (CaSR) in the kidney, the presence of a rapidly exchangeable pool in bone, and the delayed response of vitamin D 3 synthesis. Accounting for two (fast and slow) calcium storage compartments in bone allows the model to properly predict the effects of bisphophonates on the plasma levels of Ca 2+ ([Ca 2+ ] p ), PTH, and vitamin D 3 Our model also suggests that Ca 2+ exchange rates between plasma and the fast pool vary with both sex and age, allowing [Ca 2+ ] p to remain constant in spite of sex- and age-based hormonal and other differences. Our results suggest that the inconstant hypercalciuria that is observed in primary hyperparathyroidism can be attributed in part to counterbalancing effects of PTH and CaSR in the kidney. Our model also correctly predicts that calcimimetic agents such as cinacalcet bring down [Ca 2+ ] p to within its normal range in primary hyperparathyroidism. In addition, the model provides a simulation of CYP24A1 inactivation that leads to a situation reminiscent of infantile hypercalcemia. In summary, our model of calcium handling can be used to decipher the complex regulation of calcium homeostasis. Copyright © 2016 the American Physiological Society.

  16. The mechanical environment modulates intracellular calcium oscillation activities of myofibroblasts.

    Directory of Open Access Journals (Sweden)

    Charles Godbout

    Full Text Available 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.

  17. Meta-Analysis of Genome-Wide Association Studies Identifies Six New Loci for Serum Calcium Concentrations

    NARCIS (Netherlands)

    C.M. O'Seaghdha (Conall); H. Wu (Hongsheng); Q. Yang (Qiong); K. Kapur (Karen); I. Guessous (Idris); P. Zuber (Patrick); A. Köttgen (Anna); C. Stoudmann (Candice); A. Teumer (Alexander); Z. Kutalik (Zoltán); M. Mangino (Massimo); A. Dehghan (Abbas); W. Zhang (Weihua); G. Eiriksdottir (Gudny); G. Li (Guo); T. Tanaka (Toshiko); L. Portas (Laura); L.M. Lopez (Lorna); C. Hayward (Caroline); K. Lohman (Kurt); K. Matsuda (Koichi); S. Padmanabhan (Sandosh); D. Firsov (Dmitri); R. Sorice; S. Ulivi (Shelia); A.C. Brockhaus (A. Catharina); M.E. Kleber (Marcus); A. Mahajan (Anubha); F.D.J. Ernst (Florian); V. Gudnason (Vilmundur); L.J. Launer (Lenore); A. Mace (Aurelien); E.A. Boerwinkle (Eric); D.E. Arking (Dan); C. Tanikawa (Chizu); Y. Nakamura (Yusuke); M.J. Brown (Morris); J.-M. Gaspoz (Jean-Michel); J.-M. Theler (Jean-Marc); D.S. Siscovick (David); B.M. Psaty (Bruce); S.M. Bergmann (Sven); P. Vollenweider (Peter); V. Vitart (Veronique); A.F. Wright (Alan); T. Zemunik (Tatijana); M. Boban (Mladen); I. Kolcic (Ivana); P. Navarro (Pau); E.M. Brown (Edward); K. Estrada Gil (Karol); J. Ding (Jinhui); T.B. Harris (Tamara); S. Bandinelli (Stefania); D.G. Hernandez (Dena); A. Singleton (Andrew); S. Girotto; D. Ruggiero; P. d' Adamo (Pio); A. Robino (Antonietta); T. Meitinger (Thomas); C. Meisinger (Christa); G. Davies (Gail); J.M. Starr (John); J.C. Chambers (John); B.O. Boehm (Bernhard); B. Winkelmann; J. Huang (Jian); D. Murgia (Daniela); S.H. Wild (Sarah); H. Campbell (Harry); A.D. Morris (Andrew); O.H. Franco (Oscar); A. Hofman (Albert); A.G. Uitterlinden (André); F. Rivadeneira Ramirez (Fernando); U. Vol̈ker (Uwe); M. Hannemann (Mario); R. Biffar (Reiner); W. Hoffmann (Wolfgang); S.-Y. Shin; P. Lescuyer (Pierre); H. Henry (Hughes); C. Schurmann (Claudia); P. Munroe (Patricia); P. Gasparini (Paolo); N. Pirastu (Nicola); M. Ciullo; C. Gieger (Christian); W. März (Winfried); L. Lind (Lars); T.D. Spector (Timothy); G.D. Smith; I. Rudan (Igor); J.F. Wilson (James); O. Polasek (Ozren); I.J. Deary (Ian); M. Pirastu (Mario); L. Ferrucci (Luigi); Y. Liu (Yongmei); B. Kestenbaum (Bryan); J.S. Kooner (Jaspal); J.C.M. Witteman (Jacqueline); M. Nauck (Matthias); W.H.L. Kao (Wen); H. Wallaschofski (Henri); O. Bonny (Olivier); C. Fox (Craig); M. Bochud (Murielle)


    textabstractCalcium is vital to the normal functioning of multiple organ systems and its serum concentration is tightly regulated. Apart from CASR, the genes associated with serum calcium are largely unknown. We conducted a genome-wide association meta-analysis of 39,400 individuals from 17

  18. 21 CFR 184.1187 - Calcium alginate. (United States)


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

  19. Extracellular and Intracellular Regulation of Calcium Homeostasis

    Directory of Open Access Journals (Sweden)

    Felix Bronner


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

  20. Calcium phosphates for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

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


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

  1. Polysulfide calcium as multyfunctional product

    Directory of Open Access Journals (Sweden)

    G. Abramova


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

  2. [Calcium metabolism after the menopause]. (United States)

    Kanovitch, D; Klotz, H P


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

  3. Calcium-sensing beyond neurotransmitters

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Han, Weiping


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

  4. Serum calcium and risk of gastrointestinal cancer in the Swedish AMORIS study. (United States)

    Wulaningsih, Wahyu; Michaelsson, Karl; Garmo, Hans; Hammar, Niklas; Jungner, Ingmar; Walldius, Göran; Lambe, Mats; Holmberg, Lars; Van Hemelrijck, Mieke


    Observational studies have indicated that high calcium intake may prevent colorectal cancer, but as for randomized trials the results are inconclusive. Meanwhile, limited data on the link between serum calcium and cancer risk is available. We investigated the relation between serum calcium and risk of different gastrointestinal cancers in a prospective study. A cohort based on 492,044 subjects with baseline information on calcium (mmol/L) and albumin (g/L) was selected from the Swedish Apolipoprotein MOrtality RISk (AMORIS) study. Multivariable Cox proportional hazard models were used to analyse associations between standardised levels, quartiles and age/sex-specific categories of serum calcium and risk of oesophageal, stomach, colon, rectal cancer and also colorectal cancer combined, while taking into account serum albumin and other comorbidities. During 12 years of follow-up, we identified 323 incident oesophageal cancers, 782 stomach cancers, 2519 colon cancers, and 1495 rectal cancers. A positive association was found between albumin-adjusted serum calcium and risk of oesophageal [HR: 4.82 (95% CI: 2.07 - 11.19) for high compared to normal age-specific calcium levels] and colon cancer [e.g. HR: 1.07 (95% CI: 1.00 - 1.14) for every SD increase of calcium] as well as colorectal cancer [e.g. HR: 1.06 (95% CI: 1.02-1.11) for every SD increase of calcium] in women. In men there were similar but weaker non-statistically significant trends. The positive relation between serum calcium, oesophageal cancer and colorectal cancer calls for further studies including calcium regulators to evaluate whether there is a true link between calcium metabolism and development of gastrointestinal cancer.

  5. Elevated Alkaline Phosphatase in Infants With Parenteral Nutrition-Associated Liver Disease Reflects Bone Rather Than Liver Disease. (United States)

    Nandivada, Prathima; Potemkin, Alexis K; Carlson, Sarah J; Chang, Melissa I; Cowan, Eileen; O'Loughlin, Alison A; Gura, Kathleen M; Puder, Mark


    Elevated serum alkaline phosphatase (ALP) in infants with intestinal failure (IF) can be due to parenteral nutrition-associated liver disease (PNALD) or metabolic bone disease (MBD). The purpose of the study was to determine the utility of serum ALP in the diagnostic criteria for PNALD by measuring tissue-specific levels in infants with IF and PNALD. A retrospective review of patient data for 15 infants diagnosed with PNALD between December 2012 and August 2013 was performed. PNALD was defined as the presence of 2 consecutive direct bilirubin (DB) levels >2 mg/dL. Fractionated serum alkaline phosphatase was measured in each patient, while the DB was >2 mg/dL. Parathyroid hormone (PTH), vitamin D3, calcium, and phosphate levels were recorded where available. In 15 infants with PNALD, elevation in total ALP was due to marked elevations in bone-specific ALP. The median liver-specific ALP remained within the normal range. PTH, vitamin D3, calcium, and phosphate levels were within normal limits. While elevated ALP can reflect biliary stasis, the ALP elevation observed in infants with IF and PNALD is predominantly of bone rather than hepatic origin. An elevated unfractionated ALP in infants with PNALD should therefore raise suspicion of underlying bone disease, rather than being attributed to liver disease alone. © 2014 American Society for Parenteral and Enteral Nutrition.

  6. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt. (United States)


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

  7. Calcium affects on vascular endpoints

    Directory of Open Access Journals (Sweden)

    Patel Vaishali B


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

  8. The central role of calcium in the effects of cytokines on beta-cell function: implications for type 1 and type 2 diabetes. (United States)

    Ramadan, James W; Steiner, Stephen R; O'Neill, Christina M; Nunemaker, Craig S


    The appropriate regulation of intracellular calcium is a requirement for proper cell function and survival. This review focuses on the effects of proinflammatory cytokines on calcium regulation in the insulin-producing pancreatic beta-cell and how normal stimulus-secretion coupling, organelle function, and overall beta-cell viability are impacted. Proinflammatory cytokines are increasingly thought to contribute to beta-cell dysfunction not only in type 1 diabetes (T1D), but also in the progression of type 2 diabetes (T2D). Cytokine-induced disruptions in calcium handling result in reduced insulin release in response to glucose stimulation. Cytokines can alter intracellular calcium levels by depleting calcium from the endoplasmic reticulum (ER) and by increasing calcium influx from the extracellular space. Depleting ER calcium leads to protein misfolding and activation of the ER stress response. Disrupting intracellular calcium may also affect organelles, including the mitochondria and the nucleus. As a chronic condition, cytokine-induced calcium disruptions may lead to beta-cell death in T1D and T2D, although possible protective effects are also discussed. Calcium is thus central to both normal and pathological cell processes. Because the tight regulation of intracellular calcium is crucial to homeostasis, measuring the dynamics of calcium may serve as a good indicator of overall beta-cell function. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Temperature-reflection I

    DEFF Research Database (Denmark)

    McGady, David A.


    -temperature path integrals for quantum field theories (QFTs) should be T-reflection invariant. Because multi-particle partition functions are equal to Euclidean path integrals for QFTs, we expect them to be T-reflection invariant. Single-particle partition functions though are often not invariant under T......In this paper, we revisit the claim that many partition functions are invariant under reflecting temperatures to negative values (T-reflection). The goal of this paper is to demarcate which partition functions should be invariant under T-reflection, and why. Our main claim is that finite...... that T-reflection is unrelated to time-reversal. Finally, we study the interplay between T-reflection and perturbation theory in the anharmonic harmonic oscillator in quantum mechanics and in Yang-Mills in four-dimensions. This is the first in a series of papers on temperature-reflections....

  10. Strength of gamma rhythm depends on normalization.

    Directory of Open Access Journals (Sweden)

    Supratim Ray

    Full Text Available Neuronal assemblies often exhibit stimulus-induced rhythmic activity in the gamma range (30-80 Hz, whose magnitude depends on the attentional load. This has led to the suggestion that gamma rhythms form dynamic communication channels across cortical areas processing the features of behaviorally relevant stimuli. Recently, attention has been linked to a normalization mechanism, in which the response of a neuron is suppressed (normalized by the overall activity of a large pool of neighboring neurons. In this model, attention increases the excitatory drive received by the neuron, which in turn also increases the strength of normalization, thereby changing the balance of excitation and inhibition. Recent studies have shown that gamma power also depends on such excitatory-inhibitory interactions. Could modulation in gamma power during an attention task be a reflection of the changes in the underlying excitation-inhibition interactions? By manipulating the normalization strength independent of attentional load in macaque monkeys, we show that gamma power increases with increasing normalization, even when the attentional load is fixed. Further, manipulations of attention that increase normalization increase gamma power, even when they decrease the firing rate. Thus, gamma rhythms could be a reflection of changes in the relative strengths of excitation and normalization rather than playing a functional role in communication or control.

  11. Liberating Moral Reflection (United States)

    Horell, Harold D.


    The author argues that if we are to foster life-giving and liberating moral reflection, we must first liberate moral reflection from distortions; specifically, from the distorting effects of moral insensitivity, destructive moral relativism, and confusions resulting from a failure to understand the dynamics of moral reflection. The author proposes…

  12. Imaging Seismic Reflections

    NARCIS (Netherlands)

    op 't Root, T.J.P.M.; Op 't Root, Timotheus Johannes Petrus Maria


    The goal of reflection seismic imaging is making images of the Earth subsurface using surface measurements of reflected seismic waves. Besides the position and orientation of subsurface reflecting interfaces it is a challenge to recover the size or amplitude of the discontinuities. We investigate

  13. A prospective study of total and ionized serum calcium and time to fatal prostate cancer. (United States)

    Schwartz, Gary G; Skinner, Halcyon G


    Higher levels of total and ionized serum calcium have been shown to predict fatal prostate cancer in prospective studies. Because the follow-up time in these studies was relatively short, these associations could reflect the effect of clinically significant but occult prostate tumors on serum calcium levels. If this were true, prostate cancer mortality rates among men with higher levels of serum calcium should be higher during the early follow-up period and should decline thereafter. We tested this hypothesis by estimating the relative risk of death from prostate cancer in the National Health and Nutrition Examination Survey III for incremental increases in total and ionized serum calcium using Cox proportional hazards regression with time-dependent effects. Forty-nine (49) fatal prostate cancers occurred over 204 months of follow-up and 1,069,327 person-months of observation. Men with higher total serum calcium and higher serum ionized calcium had increased risks of fatal prostate cancer during the first 96 months of follow-up [Relative Hazard (RH) = 1.50 per 0.1 mmol/L total serum calcium, 95% confidence interval (CI) = 1.04-2.17; RH = 1.72 per 0.05 mmol/L ionized calcium, 95% CI = 1.11-2.66]. Evidence of an association between total and ionized serum calcium and prostate cancer deaths was not significant after 96 months. Our analyses support the hypothesis that the elevated risk for fatal prostate cancer observed in men with high serum calcium is because of the presence of extant, but occult prostate cancer. These findings have implications for the potential use of serum calcium in the detection of clinically significant prostate cancer. 2012 AACR

  14. Role of Calcium Signaling in the Transcriptional Regulation of the Apicoplast Genome of Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Sabna Cheemadan


    Full Text Available Calcium is a universal second messenger that plays an important role in regulatory processes in eukaryotic cells. To understand calcium-dependent signaling in malaria parasites, we analyzed transcriptional responses of Plasmodium falciparum to two calcium ionophores (A23187 and ionomycin that cause redistribution of intracellular calcium within the cytoplasm. While ionomycin induced a specific transcriptional response defined by up- or downregulation of a narrow set of genes, A23187 caused a developmental arrest in the schizont stage. In addition, we observed a dramatic decrease of mRNA levels of the transcripts encoded by the apicoplast genome during the exposure of P. falciparum to both calcium ionophores. Neither of the ionophores caused any disruptions to the DNA replication or the overall apicoplast morphology. This suggests that the mRNA downregulation reflects direct inhibition of the apicoplast gene transcription. Next, we identify a nuclear encoded protein with a calcium binding domain (EF-hand that is localized to the apicoplast. Overexpression of this protein (termed PfACBP1 in P. falciparum cells mediates an increased resistance to the ionophores which suggests its role in calcium-dependent signaling within the apicoplast. Our data indicate that the P. falciparum apicoplast requires calcium-dependent signaling that involves a novel protein PfACBP1.

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

    National Research Council Canada - National Science Library

    Pochet, Roland; Donato, Rosario


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

  16. Parental perceptions of the outcome and meaning of normalization. (United States)

    Knafl, Kathleen A; Darney, Blair G; Gallo, Agatha M; Angst, Denise B


    The purpose of this secondary analysis was to identify the meaning of normalization for parents of a child with a chronic genetic condition. The sample was comprised of 28 families (48 parents), selected to reflect two groups: Normalization Present (NP) and Normalization Absent (NA). Constant comparison analysis was used to identify themes characterizing parents' perceptions of the meaning of normalization. The meanings parents attributed to normalization reflected their evaluation of condition management, parenting role, and condition impact, with parents in the NP and NA groups demonstrating distinct patterns of meaning. These meaning patterns are discussed as an outcome of normalization. Providers can play a pivotal role in helping families achieve normalization by providing guidance on how to balance condition management with normal family life. (c) 2010 Wiley Periodicals, Inc.

  17. Calcium-deficiency rickets in a four-year-old boy with milk allergy. (United States)

    Davidovits, M; Levy, Y; Avramovitz, T; Eisenstein, B


    A 4-year-old boy was found to have rickets associated with normal serum levels of 25-hydroxyvitamin D and high serum levels of 1,25-dihydroxyvitamin D. These findings were thought to be the result of dietary calcium deficiency caused by the prolonged elimination from his diet of cow milk and milk products because of allergy. Adequate intake of calcium resulted in rapid improvement.

  18. Kit (W-sh) Mutation Prevents Cancellous Bone Loss during Calcium Deprivation. (United States)

    Lotinun, Sutada; Suwanwela, Jaijam; Poolthong, Suchit; Baron, Roland


    Calcium is essential for normal bone growth and development. Inadequate calcium intake increases the risk of osteoporosis and fractures. Kit ligand/c-Kit signaling plays an important role in regulating bone homeostasis. Mice with c-Kit mutations are osteopenic. The present study aimed to investigate whether impairment of or reduction in c-Kit signaling affects bone turnover during calcium deprivation. Three-week-old male WBB6F1/J-Kit (W) /Kit (W-v) /J (W/W (v) ) mice with c-Kit point mutation, Kit (W-sh) /HNihrJaeBsmJ (W (sh) /W (sh) ) mice with an inversion mutation in the regulatory elements upstream of the c-Kit promoter region, and their wild-type controls (WT) were fed either a normal (0.6% calcium) or a low calcium diet (0.02% calcium) for 3 weeks. μCT analysis indicated that both mutants fed normal calcium diet had significantly decreased cortical thickness and cancellous bone volume compared to WT. The low calcium diet resulted in a comparable reduction in cortical bone volume and cortical thickness in the W/W (v) and W (sh) /W (sh) mice, and their corresponding controls. As expected, the low calcium diet induced cancellous bone loss in the W/W (v) mice. In contrast, W (sh) /W (sh) cancellous bone did not respond to this diet. This c-Kit mutation prevented cancellous bone loss by antagonizing the low calcium diet-induced increase in osteoblast and osteoclast numbers in the W (sh) /W (sh) mice. Gene expression profiling showed that calcium deficiency increased Osx, Ocn, Alp, type I collagen, c-Fms, M-CSF, and RANKL/OPG mRNA expression in controls; however, the W (sh) mutation suppressed these effects. Our findings indicate that although calcium restriction increased bone turnover, leading to osteopenia, the decreased c-Kit expression levels in the W (sh) /W (sh) mice prevented the low calcium diet-induced increase in cancellous bone turnover and bone loss but not the cortical bone loss.

  19. Estimation of calcium and magnesium in serum and urine by atomic absorption spectrophotometry (United States)

    Thin, Christian G.; Thomson, Patricia A.


    A method has been described for the estimation of calcium and magnesium in serum and urine using atomic absorption spectrophotometry. The precision and accuracy of the techniques have been determined and were found to be acceptable. The range of values for calcium and magnesium in the sera of normal adults was found to be: serum calcium (corrected to a specific gravity of 1·026) 8·38-10·08 mg. per 100 ml.; serum magnesium 1·83-2·43 mg. per 100 ml. PMID:5602562

  20. The effects of thermal stimuli on intracellular calcium change and histamine releases in rat basophilic leukemia mast cells (United States)

    Wu, Zu-Hui; Zhu, Dan; Chen, Ji-Yao; Zhou, Lu-Wei


    The effects of thermal stimuli on rat basophilic leukemia mast cells were studied. The cells in calcium-contained or calcium-free buffers were thermally stimulated in the temperature range of 25-60 °C. The corresponding calcium ion concentration in cells [Ca2+]i as well as the released histamine from cells was measured with fluorescence staining methods. The ruthenium red (RR), a block of membrane calcium channels (transient receptor potential family V (TRPV)), was used in experiments. Under the stimulus of 25-50 °C, no significant difference on [Ca2+]i was found between these three groups of the cells in calcium-contained buffer without or with RR and cells in calcium-free saline, indicating that the increased calcium in cytosol did not result from the extracellular buffer but came from the intracellular calcium stores. The [Ca2+]i continuously increased under the temperature of 50-60 °C, but the RR and calcium-free saline can obviously diminish the [Ca2+]i increase at these high temperatures, reflecting that the opening of the TRPV2 channels leads to a calcium influx resulting in the [Ca2+]i increment. The histamine release also became significant in these cases. Since the released histamine is a well-known mediator for the microcirculation promotion, the histamine release from mast cells could be one of the mechanisms of thermal therapy.

  1. Presynaptic calcium signalling in cerebellar mossy fibres

    DEFF Research Database (Denmark)

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


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

  2. Normalized medical information visualization. (United States)

    Sánchez-de-Madariaga, Ricardo; Muñoz, Adolfo; Somolinos, Roberto; Castro, Antonio; Velázquez, Iker; Moreno, Oscar; García-Pacheco, José L; Pascual, Mario; Salvador, Carlos H


    A new mark-up programming language is introduced in order to facilitate and improve the visualization of ISO/EN 13606 dual model-based normalized medical information. This is the first time that visualization of normalized medical information is addressed and the programming language is intended to be used by medical non-IT professionals.

  3. Comparison of calcium supplementation or low-fat dairy foods on epithelial cell proliferation and differentiation. (United States)

    Holt, P R; Wolper, C; Moss, S F; Yang, K; Lipkin, M


    Epidemiological evidence suggests that dietary calcium and vitamin D intake are inversely related to incidence of colon cancer. Previous studies have demonstrated that supplementation of the diet with calcium in the form of calcium tablets or low-fat dairy foods alters colonic epithelial cell proliferation from a higher- to a lower-risk pattern. The present study compared relative effects of administration of calcium carbonate at approximately 900 mg/day (calcium) with those of a low-fat dairy food diet providing about the same amount of calcium (dairy) in a cross-over "head-to-head" study of 40 subjects at risk for colonic neoplasia. Dietary intake of macronutrients was similar in the two study periods, except for a slight increase in protein intake during dairy calcium supplementation. Rectal epithelial cell proliferation was studied in flat endoscopically normal-appearing mucosa at baseline and at the end of each of the two study periods and showed a significant reduction in epithelial crypt cell labeling index from 12.5% to 9.1% (calcium) or 9.3% (dairy) as well as in proliferating cells in the upper 40% of the crypt from 0.09 to 0.03 in the calcium- and low-fat dairy-supplemented intervention groups. No significant changes in two epithelial cell differentiation markers, cytokeratin AE1 and acidic mucins, were found. Furthermore, there were no differences in epithelial cell apoptosis or expression of the proapoptotic gene product BAK. These data indicate that increased dietary calcium given as supplements or in the diet in low-fat dairy foods lowers epithelial cell proliferation indexes from a higher- to a lower-risk pattern. Because supplemental calcium has been shown to reduce the recurrence of colonic adenomatous polyps in patients at increased risk for colonic neoplasia, our data suggest that supplemental low-fat dairy foods may also be effective.

  4. Mixed-mode oscillations in a three-store calcium dynamics model (United States)

    Liu, Peng; Liu, Xijun; Yu, Pei


    Calcium ions are important in cell process, which control cell functions. Many models on calcium oscillation have been proposed. Most of existing literature analyzed calcium oscillations using numerical methods, and found rich dynamical behaviours. In this paper, we explore a further study on an established three-store model, which contains endoplasmic reticulum (ER), mitochondria and calcium binding proteins. We conduct bifurcation analysis to identify two Hopf bifurcations, and apply normal form theory to study their stability and show that one of them is supercritical while the other is subcritical. Further, we transform the model into a slow-fast system, and then apply the geometrical singular perturbation theory to investigate the mechanism of generating slow-fast motions. The study reveals that the mechanism of generating the slow-fast oscillating behaviour in the three-store calcium model for certain parameter values is due to the relative fast change in the free calcium in cytosol, and relative slow changes in the free calcium in mitochondria and in the bounded Ca2+ binding sites on the cytosolic proteins. A further parametric study may provide some useful information for controlling harmful effect, by adjusting the amount of calcium in a human body. Numerical simulations are present to demonstrate the correct analytical predictions.

  5. Swimming behaviour and calcium incorporation into inner ear otoliths of fish after vestibular nerve transection (United States)

    Edelmann, E.; Anken, R. H.; Rahmann, H.


    Previous investigations on neonate swordtail fish (Xiphophorus helleri) revealed that otolithic calcium incorporation (visualized using the calcium tracer alizarin complexone) and thus otolith growth had ceased after nerve transection, supporting a hypothesis according to which the gravity-dependent otolith growth is regulated neuronally. Subsequent investigations on larval cichlid fish (Oreochromis mossambicus) yielded contrasting results, repeatedly depending on the particular batch of cichlids investigated. Like most neonate swordtails, Type I cichlids revealed a stop of calcium incorporation after unilateral vestibular nerve transection. Their behaviour after transection was normal, and the otolithic calcium incorporation in controls of the same batch was symmetric. In Type II cichlids, however, vestibular nerve transection had no effect on otolithic calcium incorporation. They behaved kinetotically after transection (this kind of kinetosis was qualitatively similar to the swimming behaviour exhibited by larval cichlids during microgravity in the course of parabolic aircraft flights). The otolithic calcium incorporation in control animals was asymmetric. These results show that the effects of vestibular nerve transection as well as the efficacy of the mechanism, which regulates otolith growth/otolithic calcium incorporation, are - depending on the particular batch of animals - genetically predispositioned. In conclusion, the regulation of otolithic calcium incorporation is guided neuronally, in part via the vestibular nerve and, in part, via a further pathway, which remains to be addressed in the course of future investigations.

  6. Ionized calcium serum evaluation in unilateral thyroidectomized cats

    Directory of Open Access Journals (Sweden)

    Katia Barão Corgozinho


    Full Text Available ABSTRACT. Corgozinho K.B., Cunha S.C.S., Neves A.P., Belchior C., Damico C.B., Silva C.A., Souza H.J.M.& Ferreira A.M.R. [Ionized calcium serum evaluation in unilateral thyroidectomized cats.] Avaliação do cálcio ionizado em gatos submetidos a tireoidectomia unilateral. Revista Brasileira de Medicina Veterinária 37(4:345-349, 2015. Pós-Graduação em Clínica e Reprodução Animal, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Vital Brasil Filho, 64, Niterói, RJ 24230-340, Brasil. E-mail: Seventeen hyperthyroid cats with cervical palpable nodules were submitted to clinical and laboratorial examination and they were prepared to surgery. Unilateral thyroparathyroidectomy with parathyroid gland autotransplantation was performed. Concentrations of serum urea, creatinine, alkaline phosphatase, alanine aminotransferase, phosphorus, potassium, total thyroxine and hematologic profile were determined before and seven days after surgery. Blood samples for serum ionized calcium concentration were collected before and after surgery on days 1, 2, 7, 15, 21. All cats had ionized calcium concentration within the reference range before surgery. Serum calcium concentration fell significantly in all cats within 24 hours after surgery. Hypocalcemia occurred in two cats without clinical signs. Ionized calcium concentration decreased after surgery and returned to normal levels on day 7 postoperatively. The results of this study suggest that calcium concentration must be measured before surgery in cats submitted to thyroidectomy even if they are submitted to unilateral technique.

  7. Measurement of calcium content of gallstones by computed tomography and the relationship between gallbladder function and calcification of gallstones

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, Masashi; Tamasawa, Naoki; Takebe, Kazuo (Hirosaki Univ. (Japan). School of Medicine); Makino, Isao; Sakuraba, Kiyoshi; Tamura, Toyokazu


    To evaluate the relationship between gallbladder function and calcification of gallstones, we studied gallbladder contractility by oral cholecystography, the computed tomography (CT) number of stones for 30 gallstone patients, calcium content of 13 stones operatively extirpated, and the degree of inflammatory change in 13 surgical gallbladder specimens. There was significant correlation between the calcium content and CT numbers of stones, and 1% of the calcium content of gallstone was approximately equal to 40 Hounsfield Units (HU) of the CT number. The calcium content of stones in patients with normal gallbladder contractility was extrapolated to be below 1.5%, while that with poor contractility ranged from 0% to 21%. Additionally there is a possibility that calcium content increases, related to the inflammatory change of gallbladder. Hence our results suggested that measurement of the CT number of stones is useful to evaluate the calcium content of gallstones, and that the gallbladder contractility could be one of the factors to influence calcification of stones. (author).

  8. Masses of exotic calcium isotopes pin down nuclear forces. (United States)

    Wienholtz, F; Beck, D; Blaum, K; Borgmann, Ch; Breitenfeldt, M; Cakirli, R B; George, S; Herfurth, F; Holt, J D; Kowalska, M; Kreim, S; Lunney, D; Manea, V; Menéndez, J; Neidherr, D; Rosenbusch, M; Schweikhard, L; Schwenk, A; Simonis, J; Stanja, J; Wolf, R N; Zuber, K


    The properties of exotic nuclei on the verge of existence play a fundamental part in our understanding of nuclear interactions. Exceedingly neutron-rich nuclei become sensitive to new aspects of nuclear forces. Calcium, with its doubly magic isotopes (40)Ca and (48)Ca, is an ideal test for nuclear shell evolution, from the valley of stability to the limits of existence. With a closed proton shell, the calcium isotopes mark the frontier for calculations with three-nucleon forces from chiral effective field theory. Whereas predictions for the masses of (51)Ca and (52)Ca have been validated by direct measurements, it is an open question as to how nuclear masses evolve for heavier calcium isotopes. Here we report the mass determination of the exotic calcium isotopes (53)Ca and (54)Ca, using the multi-reflection time-of-flight mass spectrometer of ISOLTRAP at CERN. The measured masses unambiguously establish a prominent shell closure at neutron number N = 32, in excellent agreement with our theoretical calculations. These results increase our understanding of neutron-rich matter and pin down the subtle components of nuclear forces that are at the forefront of theoretical developments constrained by quantum chromodynamics.

  9. Masses of exotic calcium isotopes pin down nuclear forces

    CERN Document Server

    Wienholtz, F; Blaum, K; Borgmann, Ch; Breitenfeldt, M; Cakirli, R B; George, S; Herfurth, F; Holt, J D; Kowalska, M; Kreim, S; Lunney, D; Manea, V; Menéndez, J; Neidherr, D; Rosenbusch, M; Schweikhard, L; Schwenk, A; Simonis, J; Stanja, J; Wolf, R N; Zuber, K


    The properties of exotic nuclei on the verge of existence play a fundamental part in our understanding of nuclear interactions. Exceedingly neutron-rich nuclei become sensitive to new aspects of nuclear forces. Calcium, with its doubly magic isotopes $^{40}$Ca and $^{48}$Ca, is an ideal test for nuclear shell evolution, from the valley of stability to the limits of existence. With a closed proton shell, the calcium isotopes mark the frontier for calculations with three-nucleon forces from chiral effective field theory. Whereas predictions for the masses of $^{51}$Ca and $^{52}$Ca have been validated by direct measurements$^4$, it is an open question as to how nuclear masses evolve for heavier calcium isotopes. Here we report the mass determination of the exotic calcium isotopes $^{53}$Ca and $^{54}$Ca, using the multi-reflection time-of-flight mass spectrometer of ISOLTRAP at CERN. The measured masses unambiguously establish a prominent shell closure at neutron number N = 32, in excellent agreement with our t...

  10. Calcium metabolism and cardiovascular function after spaceflight (United States)

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


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

  11. Recruited renin-containing renal microvascular cells demonstrate the calcium paradox regulatory phenotype

    Directory of Open Access Journals (Sweden)

    MacGriff S


    Full Text Available Spencer MacGriff,1 Richard E Woo,1 M Cecilia Ortiz-Capisano,1 Douglas K Atchison,1,2 William H Beierwaltes1,2 1Department of Internal Medicine, Hypertension and Vascular Research Division, Henry Ford Hospital, 2Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA Abstract: Renin is the critical regulatory enzyme for production of angiotensin (Ang-II, a potent vasoconstrictor involved in regulating blood pressure and in the pathogenesis of hypertension. Chronic sodium deprivation enhances renin secretion from the kidney, due to recruitment of additional cells from the afferent renal microvasculature to become renin-producing rather than just increasing release from existing juxtaglomerular (JG cells. JG cells secrete renin inversely proportional to extra- and intracellular calcium, a unique phenomenon characteristic of the JG regulatory phenotype known as the “calcium paradox.” It is not known if renin secreted from recruited renin-containing cells is regulated similarly to native JG cells, and therefore acquires this JG cell phenotype. We hypothesized that non-JG cells in renal microvessels recruited to produce renin in response to chronic dietary sodium restriction would demonstrate the calcium paradox, characteristic of the JG cell phenotype. Histology showed recruitment of upstream arteriolar renin in response to sodium restriction compared to normal-diet rats. Renin fluorescence intensity increased 53% in cortices of sodium-restricted rats (P<0.001. We measured renin release from rat afferent microvessels, isolated using iron oxide nanopowder and incubated in either normal or low-calcium media. Basal renin release from normal sodium-diet rat microvessels in normal calcium media was 298.1±44.6 ng AngI/mL/hour/mg protein, and in low-calcium media increased 39% to 415.9±71.4 ng AngI/mL/hour/mg protein (P<0.025. Renin released from sodium-restricted rat microvessels increased 50% compared to samples from

  12. [Regulatory mechanism of calcium metabolism. (United States)

    Ozono, Keiichi

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

  13. Calcium signaling and cell proliferation. (United States)

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


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

  14. Calcium regulation of muscle contraction. (United States)

    Szent-Györgyi, A G


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

  15. Chapter 1: Direct Normal Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Myer, Daryl R.


    This chapter addresses the quantitative and qualitative aspects of the solar resource, the direct solar radiation. It discusses the total or integrated broadband direct beam extraterrestrial radiation (ETR). This total integrated irradiance is comprised of photons of electromagnetic radiation. The chapter also discusses the impact of the atmosphere and its effect upon the direct normal irradiance (DNI) beam radiation. The gases and particulates present in the atmosphere traversed by the direct beam reflect, absorb, and scatter differing spectral regions and proportions of the direct beam, and act as a variable filter. Knowledge of the available broadband DNI beam radiation resource data is essential in designing a concentrating photovoltaic (CPV) system. Spectral variations in the DNI beam radiation affect the performance of a CPV system depending on the solar cell technology used. The chapter describes propagation and scattering processes of circumsolar radiation (CSR), which includes the Mie scattering from large particles.

  16. Dissenting in Reflective Conversations

    DEFF Research Database (Denmark)

    Bjørn, Pernille; Boulus, Nina


    Reflective monitoring of research practices is essential. However, we often lack formal training in the practices of doing action research, and descriptions of actual inquiry practice are seldom included in publications. Our aim is to provide a glimpse of self-reflective practices based on our...... gradually evolved into second-person inquiry. We argue that enacting second-person reflective conversations renders alternative strategies for handling uncertainties through articulation of the tacit assumptions within particular empirical situations. Finally, we argue that reflective conversations should...... a methodological reflective approach that provides space for taking seriously uncertainties experienced in the field as these can be a catalyst for learning and sharpening our theoretical and empirical skills as action researchers. Through first-person inquiry, we investigate how our reflective conversations...

  17. A Seismic Analysis for Reflective Metal Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyuhyung; Kim, Taesoon [KHNP CRI, Daejeon (Korea, Republic of)


    U.S. NRC (Nuclear Regulatory Commission) GSI- 191 (Generic Safety Issue-191) is concerned about the head-loss of emergency core cooling pumps caused by calcium silicate insulation debris accumulated on a sump screen when a loss of coolant accident (LOCA). In order to cope with the concern, many nuclear plants in U. S. have been replacing calcium silicate insulation in containment building with reflective metal insulation (RMI). In Korea, RMI has been used for only reactor vessels recently constructed, but the RMI was imported. Therefore, we have been developing the domestic design of RMI to supply to nuclear power plants under operation and construction in relation to the GSI-191. This paper covers that the structural integrity of the RMI assembly was evaluated under SSE (safety shutdown earthquake) load. An analysis model was built for the seismic test system of a reflective metal insulation assembly and pre-stress, modal, and spectrum analysis for the model were performed using a commercial structural analysis code, ANSYS. According to the results of the analyses, the buckles fastening the RMIs showed the structural integrity under the required response spectrum containing the safety shutdown earthquake loads applied to main components in containment building. Consequently, since the RMI isn't disassembled under the SSE load, the RMI is judged not to affect safety related components.

  18. Tandem resonator reflectance modulator (United States)

    Fritz, I.J.; Wendt, J.R.


    A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors. 8 figs.

  19. Can total cardiac calcium predict the coronary calcium score? (United States)

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


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

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

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

  2. Media for Reflection

    DEFF Research Database (Denmark)

    Knudsen, Morten


    This article develops the concept media for reflection in the interest of conceptualizing the interpretative frames that enable and limit reflection in management and leadership education. The concept ‘media for reflection’ allows us to conceptualize the social and cultural mediation of reflection...... of the mediations is analysed as well as the societal and organizational background. Furthermore, the means by which the two media enable and limit reflection in different ways is compared. Finally, the article discusses possible implications of the analysis in terms of management and leadership education....

  3. Normal Functioning Family (United States)

    ... Spread the Word Shop AAP Find a Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care ... Español Text Size Email Print Share Normal Functioning Family Page Content Article Body Is there any way ...

  4. Monitoring the normal body

    DEFF Research Database (Denmark)

    Nissen, Nina Konstantin; Holm, Lotte; Baarts, Charlotte


    Introduction : An extensive body of literature is concerned with obese people, risk, and weight management. However, little is known about weight management among people not belonging to the extreme BMI categories. Management of weight among normal-weight and moderately overweight individuals...... provides us with knowledge about how to prevent future overweight or obesity. This paper investigates body size ideals and monitoring practices among normal-weight and moderately overweight people. Methods : The study is based on in-depth interviews combined with observations. 24 participants were...... recruited by strategic sampling based on self-reported BMI 18.5-29.9 kg/m2 and socio-demographic factors. Inductive analysis was conducted. Results : Normal-weight and moderately overweight people have clear ideals for their body size. Despite being normal weight or close to this, they construct a variety...

  5. Normal growth and development (United States)

    ... page: // Normal growth and development To use the sharing features on this page, please enable JavaScript. A child's growth and development can be divided into four periods: Infancy Preschool ...

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

    Directory of Open Access Journals (Sweden)

    Dmitry eSamigullin


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

  7. Calcium fertilization increases the concentration of calcium in sapwood and calcium oxalate in foliage of red spruce (United States)

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


    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...

  8. The amazing normal forces


    Petrache, Horia I.


    This manuscript is written for students in introductory physics classes to address some of the common difficulties and misconceptions of the normal force, especially the relationship between normal and friction forces. Accordingly, it is intentionally informal and conversational in tone to teach students how to build an intuition to complement mathematical formalism. This is accomplished by beginning with common and everyday experience and then guiding students toward two realizations: (i) Th...

  9. Normalization Theory for XML


    Libkin, Leonid


    Specifications of XML documents typically consist of typing information (e.g., a DTD), and integrity constraints. Just like relational schema specifications, not all are good – some are prone to redundancies and update anomalies. In the relational world we have a well-developed theory of data design (also known as normalization). A few definitions of XML normal forms have been proposed, but the main question is why a particular design is good. In the XML world, we still lack universally accep...

  10. Relationship between mycotoxicosis and calcium during preproduction period in layers

    Directory of Open Access Journals (Sweden)

    T. S. Qubih


    Full Text Available This study was conducted to examine field cases of mycotoxicosis (A flatoxicosis and ochratoxicosis and their effects on calcium during the preproduction period of 1SA brown pullets. Birds were 12-15 weeks of age. The feed was subjected to analysis for mycotoxin and blood samples were laboratory diagnosed for infectious bronchitis and infectious bursal viruses antibody titer and for determination calcium level. Clinical signs of affected birds were rubbery bone, ruffled feather, paleness and high mortality. Necropsy findings of sick birds were characterized by muscle dehydration, enlarged livers yellowished, kidney enlargement and urate deposition. Histopathological features of liver consisted of capsular thickening hepatocellular necrosis, subcapsular infiltration with inflammatory kidneys cells showed swelling of tubular cells, deposition of calcium between kidney tubules with infiltration of inflammatory cells. ELISA test revealed the presence of 800 ppb aflatoxin and 100 ppb ochratoxin. Normal titers of infectious bronchitis virus and infectious bursal diseases antibodies were recorded. Low blood calcium level of 8.2 mg/dl was registered in the tested blood samples.

  11. Calcium-regulated import of myosin IC into the nucleus. (United States)

    Maly, Ivan V; Hofmann, Wilma A


    Myosin IC is a molecular motor involved in intracellular transport, cell motility, and transcription. Its mechanical properties are regulated by calcium via calmodulin binding, and its functions in the nucleus depend on import from the cytoplasm. The import has recently been shown to be mediated by the nuclear localization signal located within the calmodulin-binding domain. In the present paper, it is demonstrated that mutations in the calmodulin-binding sequence shift the intracellular distribution of myosin IC to the nucleus. The redistribution is displayed by isoform B, described originally as the "nuclear myosin," but is particularly pronounced with isoform C, the normally cytoplasmic isoform. Furthermore, experimental elevation of the intracellular calcium concentration induces a rapid import of myosin into the nucleus. The import is blocked by the importin β inhibitor importazole. These findings are consistent with a mechanism whereby calmodulin binding prevents recognition of the nuclear localization sequence by importin β, and the steric inhibition of import is released by cell signaling leading to the intracellular calcium elevation. The results establish a mechanistic connection between the calcium regulation of the motor function of myosin IC in the cytoplasm and the induction of its import into the nucleus. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Calcium release from experimental dental materials. (United States)

    Okulus, Zuzanna; Buchwald, Tomasz; Voelkel, Adam


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

  13. Vitamin D, Calcium, and Bone Health (United States)

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

  14. 21 CFR 184.1229 - Calcium stearate. (United States)


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

  15. Bioactive and Hemocompatible Calcium Sulphoaluminate Cement


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


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

  16. Electrochemical Induced Calcium Phosphate Precipitation

    NARCIS (Netherlands)

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


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

  17. Reflective Lifeworld Research

    African Journals Online (AJOL)


    May 1, 2009 ... Reflective Lifeworld Research is a suitable title for a text that argues for, and gives convincing philosophical credence to, a qualitative sensibility in the human sciences. The key concept is 'reflective'. This is a rightful scientific attitude, the implications of which become the main theme of an academic.

  18. Earth's Reflection: Albedo (United States)

    Gillette, Brandon; Hamilton, Cheri


    When viewing objects of different colors, you might notice that some appear brighter than others. This is because light is reflected differently from various surfaces, depending on their physical properties. The word "albedo" is used to describe how reflective a surface is. The Earth-atmosphere has a combined albedo of about 30%, a number that is…

  19. Reflective Learning in Practice. (United States)

    Brockbank, Anne, Ed.; McGill, Ian, Ed.; Beech, Nic, Ed.

    This book contains 22 papers on reflective learning in practice. The following papers are included: "Our Purpose" (Ann Brockbank, Ian McGill, Nic Beech); "The Nature and Context of Learning" (Ann Brockbank, Ian McGill, Nic Beech); "Reflective Learning and Organizations" (Ann Brockbank, Ian McGill, Nic Beech);…

  20. Reflection: A Socratic approach (United States)

    Van Seggelen – Damen, Inge C. M.; Van Hezewijk, René; Helsdingen, Anne S.; Wopereis, Iwan G. J. H.


    Reflection is a fuzzy concept. In this article we reveal the paradoxes involved in studying the nature of reflection. Whereas some scholars emphasize its discursive nature, we go further and underline its resemblance to the self-biased dialogue Socrates had with the slave in Plato’s Meno. The individual and internal nature of the reflection process creates difficulty for studying it validly and reliably. We focus on methodological issues and use Hans Linschoten’s view of coupled systems to identify, analyze, and interpret empirical research on reflection. We argue that researchers and research participants can take on roles in several possible system couplings. Depending on who controls the manipulation of the stimulus, who controls the measuring instrument, who interprets the measurement and the response, different types of research questions can be answered. We conclude that reflection may be validly studied by combining different couplings of experimenter, manipulation, stimulus, participant, measurement, and response. PMID:29249867

  1. Self-Reflection

    DEFF Research Database (Denmark)

    Fausing, Bent


    and physical bodies are constantly broken with technology. Perception and reflection are in synergy. Reflection means etymologically to bend back, to mirror, and to think. My presentation will take its point of departure in this etymology and make perspectives to modern use of refection in digital media. I...... will take a look at the establishing of the modern self and possibilities of self-reflection, too. My examples will be from the so-called dark-selfies and from a new selfie form, which merge the present with the previous progressing into the future. I will discuss the media reflections as loos and/or gain....... As another but short viewpoint telepresence, Skype, will be discussed, where new screen types, presence and reflections are established. In a perspective, I debate my term sore-society in relation to my topic and especially the dark selfies....

  2. 21 CFR 582.7187 - Calcium alginate. (United States)


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

  3. Abnormalities of serum calcium and magnesium (United States)

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

  4. Modularized study of human calcium signalling pathway

    Indian Academy of Sciences (India)


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

  5. 21 CFR 582.1191 - Calcium carbonate. (United States)


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

  6. 21 CFR 582.5191 - Calcium carbonate. (United States)


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

  7. Mechanism of store-operated calcium entry

    Indian Academy of Sciences (India)

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

  8. Mitochondrial Calcium Sparkles Light Up Astrocytes. (United States)

    MacVicar, Brian A; Ko, Rebecca W Y


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

  9. 21 CFR 182.1217 - Calcium phosphate. (United States)


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

  10. 21 CFR 582.1217 - Calcium phosphate. (United States)


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

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

    African Journals Online (AJOL)

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

  12. Calcium Orthophosphate-Based Bioceramics

    Directory of Open Access Journals (Sweden)

    Sergey V. Dorozhkin


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

  13. Calcium or resistant starch does not affect colonic epithelial cell proliferation throughout the colon in adenoma patients : A randomized controlled trial

    NARCIS (Netherlands)

    van Gorkom, Britta A P; Karrenbeld, Arend; van der Sluis, Tineke; Zwart, Nynke; van der Meer, Roelof; de Vries, Elisabeth G E; Kleibeuker, Jan H


    Patients with a history of sporadic adenomas have increased epithelial cell proliferative activity, an intermediate risk marker for colorectal cancer. Reduction of proliferation by dietary intervention may reflect a decreased colorectal cancer risk. To evaluate whether calcium or resistant starch

  14. A simplified derivation of leaf normal spherical coordinates (United States)

    Card, Don H.


    The paper presents formulas for the direction in spherical coordinates of the normal vector to a planar leaf in terms of the coordinates of incident and reflected rays. A simple idea from vector analysis is applied. These formulas are important in plant canopy modeling and experimental data collection in situations where specular reflection at optical wavelengths plays a part.

  15. Calcium channel-dependent molecular maturation of photoreceptor synapses.

    Directory of Open Access Journals (Sweden)

    Nawal Zabouri

    Full Text Available Several studies have shown the importance of calcium channels in the development and/or maturation of synapses. The Ca(V1.4(α(1F knockout mouse is a unique model to study the role of calcium channels in photoreceptor synapse formation. It features abnormal ribbon synapses and aberrant cone morphology. We investigated the expression and targeting of several key elements of ribbon synapses and analyzed the cone morphology in the Ca(V1.4(α(1F knockout retina. Our data demonstrate that most abnormalities occur after eye opening. Indeed, scaffolding proteins such as Bassoon and RIM2 are properly targeted at first, but their expression and localization are not maintained in adulthood. This indicates that either calcium or the Ca(V1.4 channel, or both are necessary for the maintenance of their normal expression and distribution in photoreceptors. Other proteins, such as Veli3 and PSD-95, also display abnormal expression in rods prior to eye opening. Conversely, vesicle related proteins appear normal. Our data demonstrate that the Ca(V1.4 channel is important for maintaining scaffolding proteins in the ribbon synapse but less vital for proteins related to vesicular release. This study also confirms that in adult retinae, cones show developmental features such as sprouting and synaptogenesis. Overall we present evidence that in the absence of the Ca(V1.4 channel, photoreceptor synapses remain immature and are unable to stabilize.

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


    Huaigang Cheng; Xiaoxi Zhang; Huiping Song


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


    Directory of Open Access Journals (Sweden)



    Full Text Available

    Normal" style="margin: 0cm 0cm 0pt; line-height: normal; text-align: justify; mso-layout-grid-align: none;"> Experimental and epidemiological evidences have demonstrated that calcium inhibits iron absorption; calcium carbonate being one of the most effective calcium sources to reduce iron absorption from dietary origin or from iron sulfate. In the present work, the short-term effect of calcium from calcium carbonate on iron absorption was studied in rats, using different iron compounds (monosodium ferric EDTA, iron-bys-glicine, iron peptide complex with iron sulfate as a control. Eighty (80 animals were divided into groups of 10 animals each with homogeneous weight. After 18h fast, the animals received by gavage 5 mL of a dispersion containing one of the iron compounds (1mg Fe/kg body weight, concomitantly or not with calcium carbonate at a molar ratio of 150:1 (Ca/Fe. Two hours after the administration, the animals were sacrificed and blood was collected for serum iron determination (iron transfer rate from intestinal lumen to blood compartment. Additionally, the intestines were collected for soluble iron determination (available iron. The results demonstrated that calcium ion from calcium carbonate inhibits the iron absorption from iron sulfate, but not from organic iron (di- or trivalent complexes.

  18. Mammary-Specific Ablation of the Calcium-Sensing Receptor During Lactation Alters Maternal Calcium Metabolism, Milk Calcium Transport, and Neonatal Calcium Accrual (United States)

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


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

  19. Apatite Formation from Amorphous Calcium Phosphate and Mixed Amorphous Calcium Phosphate/Amorphous Calcium Carbonate. (United States)

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


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

  20. Reflectivity in Research Practice

    Directory of Open Access Journals (Sweden)

    Luigina Mortari


    Full Text Available The article grounds on the assumption that researchers, in order to be not mere technicians but competent practitioners of research, should be able to reflect in a deep way. That means they should reflect not only on the practical acts of research but also on the mental experience which constructs the meaning about practice. Reflection is a very important mental activity, both in private and professional life. Learning the practice of reflection is fundamental because it allows people to engage into a thoughtful relationship with the world-life and thus gain an awake stance about one’s lived experience. Reflection is a crucial cognitive practice in the research field. Reflexivity is largely practiced in qualitative research, where it is used to legitimate and validate research procedures. This study introduces different perspectives of analysis by focusing the discourse on the main philosophical approaches to reflection: pragmatistic, critical, hermeneutic, and finally phenomenological. The thesis of this study is that the phenomenological theory makes possible to analyze in depth the reflective activity and just by that to support an adequate process of training of the researcher.

  1. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.


    This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...... Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process...

  2. Medically-enhanced normality

    DEFF Research Database (Denmark)

    Møldrup, Claus; Traulsen, Janine Morgall; Almarsdóttir, Anna Birna


    Objective: To consider public perspectives on the use of medicines for non-medical purposes, a usage called medically-enhanced normality (MEN). Method: Examples from the literature were combined with empirical data derived from two Danish research projects: a Delphi internet study and a Telebus......, to optimise economic, working and family conditions. The term "doping" does not cover or explain the use of medicines as enhancement among healthy non-athletes. Conclusion: We recommend wider use of the term medically-enhanced normality as a conceptual framework for understanding and analysing perceptions...

  3. The Calcium Wave of Vegetable Cells

    Directory of Open Access Journals (Sweden)

    TD. Geydan


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

  4. Quantum transport in graphene normal-metal superconductor- normal-metal structures

    Directory of Open Access Journals (Sweden)

    H. Mohammadpour


    Full Text Available  We study the transport of electrons in a graphene NSN structure in which two normal regions are connected by a superconducting strip of thickness d. Within Dirac-Bogoliubov-de Gennes equations we describe the transmission through the contact in terms of different scattering processes consisting of quasiparticle cotunneling, local and crossed Andreev reflections. Compared to a fully normal structure we show that the angular dependence of the transmission probability is significantly modified by the presence of superconducting correlations. This modifation can be explained in terms of the interplay between Andreev reflection and Klein tunneling of chiral quasiparticles. We further analyze the energy dependence of the resulting differential conductance of the structure. The subgap differential conductance shows features of Andreev reflection and cotunelling processes, which tends to the values of an NS structure for large ds. Above the gap, the differential conductance shows an oscillatory behavior with energy even at very large ds.

  5. Effects of metabolic acidosis and alkalosis on sodium and calcium transport in the dog kidney. (United States)

    Sutton, R A; Wong, N L; Dirks, J H


    Clearance and micropuncture studies have been performed in dogs to examine the effects of acute and chronic metabolic acidosis and acute alkalosis on tubular sodium and calcium transport. Acute metabolic acidosis, induced by the infusion of hydrochloric acid, decreased proximal fluid reabsorption and increased the fractional delivery of sodium and calcium to the distal tubule, but not to the final urine. In comparison with normal dogs, dogs with chronic metabolic acidosis (induced by feeding ammonium chloride) showed an increase in proximal fluid reabsorption and a dissociation of calcium from sodium reabsorption more distally, leading to an increased delivery of calcium relative to sodium at the distal tubule and in the final urine. The infusion of sodium bicarbonate to correct chronic metabolic acidosis, both in intact and thyroparathyroidectomized (TPTX) dogs, reduced proximal fluid reabsorption and caused a selective enhancement of calcium reabsorption relative to sodium in the more distal nephron, resulting in a reversal of the dissociation observed in acidosis, both at the distal tubule and in the final urine. By contrastin fusion of sodium chloride in parathyroid-intact acidotic dogs did not reduce proximal fluid reabsorption or enhance tubular calcium reabsorption. In nonacidotic dogs, both intact and TPTX, infusion of sodium bicarconate to induce acute alkalosis resulted in selhese data demonstrate the presence of a component of tubular calcium reabsorption situated beyond the proximal tubule, which is inhibited by chronic (but not acute) metabolic acidosis and enhanced by metabolic alkalosis (or bicarbonate infusion) independently of parathyroid hormone.

  6. MICU1 Serves as a Molecular Gatekeeper to Prevent In Vivo Mitochondrial Calcium Overload

    Directory of Open Access Journals (Sweden)

    Julia C. Liu


    Full Text Available MICU1 is a component of the mitochondrial calcium uniporter, a multiprotein complex that also includes MICU2, MCU, and EMRE. Here, we describe a mouse model of MICU1 deficiency. MICU1−/− mitochondria demonstrate altered calcium uptake, and deletion of MICU1 results in significant, but not complete, perinatal mortality. Similar to afflicted patients, viable MICU1−/− mice manifest marked ataxia and muscle weakness. Early in life, these animals display a range of biochemical abnormalities, including increased resting mitochondrial calcium levels, altered mitochondrial morphology, and reduced ATP. Older MICU1−/− mice show marked, spontaneous improvement coincident with improved mitochondrial calcium handling and an age-dependent reduction in EMRE expression. Remarkably, deleting one allele of EMRE helps normalize calcium uptake while simultaneously rescuing the high perinatal mortality observed in young MICU1−/− mice. Together, these results demonstrate that MICU1 serves as a molecular gatekeeper preventing calcium overload and suggests that modulating the calcium uniporter could have widespread therapeutic benefits.

  7. Hypocalciuric Hypercalcemia due to Impaired Renal Tubular Calcium Excretion in a Type 2 Diabetic Patient

    Directory of Open Access Journals (Sweden)

    Sihao Yang


    Full Text Available The case we presented here was a 73-year-old gentleman, who was admitted to endocrinology department due to recurrent fatigue for 1 year. He had medical histories of type 2 diabetes for 18 years and developed CKD 4 years ago. He also suffered from dilated cardiomyopathy, and coronary heart disease, moderate sleep apnea syndrome, primary hypothyroidism, and gout. His treatment regimen was complicated which included Caltrate D and compound α-keto acid (1200 mg calcium/d. Laboratory examination revealed that his serum calcium level elevated, 24-hour urine calcium output decreased, PTH level was suppressed, and 25-hydroxyvitamin D was in normal low range. No other specific abnormalities were found in serum bone turnover markers, ultrasonography, computed tomography, and bone scintigraphy. The diagnosis was suggested to be hypocalciuric hypercalcemia but was different from familial or acquired hypocalciuric hypercalcemia which were featured by elevated PTH level. The patient was asked to restrict calcium intake and to take diuretics; then his serum calcium level gradually lowered. In brief, patients with CKD could present with hypocalciuric hypercalcemia due to impaired renal calcium excretion. In this case, calcium restriction should be applied for treatment.

  8. Swimming Behavior and Calcium Incorporation into inner Ear Otoliths of Fish after vestibular Nerve Transection (United States)

    Edelmann, E.; Anken, R.; Rahmann, H.

    Previous investigations on neonate swordtail fish (Xiphophorus helleri) revealed that otolithic calcium incorporation (visualized using the calcium-tracer alizarin- complexone) and thus otolith growth had ceased after nerve transection, supporting a hypothesis according to which the gravity-dependent otolith growth is regulated neuronally. Subsequent investigations on larval cichlid fish (Oreochromis mossambicus) yielded contrasting results, repeatedly depending on the particular batch of cichlids investigated: Like neonate swordtails, type I cichlids revealed a stop of calcium incorporation after unilateral vestibular nerve transection. Their behaviour after transection was normal and the otolithic calcium incorporation in controls of the same batch was symmetrical. In type II cichlids, however, vestibular nerve transection had no effect on otolithic calcium incorporation. They behaved kinetotically after transection (this kind of kinetosis was qualitatively similar to the swimming behaviour exhibited by larval cichlids during microgravity in the course of parabolic aircraft flights). The otolithic calcium incorporation in control animals was asymmetrical. These results stongly suggest that the effects of vestibular nerve transection as well as the efficacy of the mechanism, which regulates otolith growth/otolithic calcium incorporation, are - depending on the particular batch of animals - genetically predispositioned. Thus, it is assumed that the mechanisms regulating otolith growth and equlibibrium differ in the two types of cichlid fish. This work was financially supported by the German Aerospace Center (DLR) e.V. (FKZ: 50 WB 9997).

  9. Amplitude Normalization of Dendritic EPSPs at the Soma of Binaural Coincidence Detector Neurons of the Medial Superior Olive. (United States)

    Winters, Bradley D; Jin, Shan-Xue; Ledford, Kenneth R; Golding, Nace L


    The principal neurons of the medial superior olive (MSO) encode cues for horizontal sound localization through comparisons of the relative timing of EPSPs. To understand how the timing and amplitude of EPSPs are maintained during propagation in the dendrites, we made dendritic and somatic whole-cell recordings from MSO principal neurons in brain slices from Mongolian gerbils. In somatic recordings, EPSP amplitudes were largely uniform following minimal stimulation of excitatory synapses at visualized locations along the dendrites. Similar results were obtained when excitatory synaptic transmission was eliminated in a low calcium solution and then restored at specific dendritic sites by pairing input stimulation and focal application of a higher calcium solution. We performed dual dendritic and somatic whole-cell recordings to measure spontaneous EPSPs using a dual-channel template-matching algorithm to separate out those events initiated at or distal to the dendritic recording location. Local dendritic spontaneous EPSP amplitudes increased sharply in the dendrite with distance from the soma (length constant, 53.6 μm), but their attenuation during propagation resulted in a uniform amplitude of ∼0.2 mV at the soma. The amplitude gradient of dendritic EPSPs was also apparent in responses to injections of identical simulated excitatory synaptic currents in the dendrites. Compartmental models support the view that these results extensively reflect the influence of dendritic cable properties. With relatively few excitatory axons innervating MSO neurons, the normalization of dendritic EPSPs at the soma would increase the importance of input timing versus location during the processing of interaural time difference cues in vivoSIGNIFICANCE STATEMENT The neurons of the medial superior olive analyze cues for sound localization by detecting the coincidence of binaural excitatory synaptic inputs distributed along the dendrites. Previous studies have shown that dendritic

  10. Vitamin D: calcium and bone homeostasis during evolution (United States)

    Bouillon, Roger; Suda, Tatsuo


    Vitamin D3 is already found early in the evolution of life but essentially as inactive end products of the photochemical reaction of 7-dehydrocholestol with ultraviolet light B. A full vitamin D (refers to vitamin D2 and D3) endocrine system, characterized by a specific VDR (vitamin D receptor, member of the nuclear receptor family), specific vitamin D metabolizing CYP450 enzymes regulated by calciotropic hormones and a dedicated plasma transport-protein is only found in vertebrates. In the earliest vertebrates (lamprey), vitamin D metabolism and VDR may well have originated from a duplication of a common PRX/VDR ancestor gene as part of a xenobiotic detoxification pathway. The vitamin D endocrine system, however, subsequently became an important regulator of calcium supply for an extensive calcified skeleton. Vitamin D is essential for normal calcium and bone homeostasis as shown by rickets in vitamin D-deficient growing amphibians, reptiles, birds and mammals. From amphibians onward, bone is gradually more dynamic with regulated bone resorption, mainly by combined action of PTH and 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the generation and function of multinucleated osteoclasts. Therefore, bone functions as a large internal calcium reservoir, under the control of osteoclasts. Osteocytes also display a remarkable spectrum of activities, including mechanical sensing and regulating mineral homeostasis, but also have an important role in global nutritional and energy homeostasis. Mineralization from reptiles onward is under the control of well-regulated SIBLING proteins and associated enzymes, nearly all under the control of 1,25(OH)2D3. The vitamin D story thus started as inert molecule but gained an essential role for calcium and bone homeostasis in terrestrial animals to cope with the challenge of higher gravity and calcium-poor environment. PMID:24466411

  11. The Plasma Membrane Calcium ATPases and Their Role as Major New Players in Human Disease. (United States)

    Stafford, Nicholas; Wilson, Claire; Oceandy, Delvac; Neyses, Ludwig; Cartwright, Elizabeth J


    The Ca2+ extrusion function of the four mammalian isoforms of the plasma membrane calcium ATPases (PMCAs) is well established. There is also ever-increasing detail known of their roles in global and local Ca2+ homeostasis and intracellular Ca2+ signaling in a wide variety of cell types and tissues. It is becoming clear that the spatiotemporal patterns of expression of the PMCAs and the fact that their abundances and relative expression levels vary from cell type to cell type both reflect and impact on their specific functions in these cells. Over recent years it has become increasingly apparent that these genes have potentially significant roles in human health and disease, with PMCAs1-4 being associated with cardiovascular diseases, deafness, autism, ataxia, adenoma, and malarial resistance. This review will bring together evidence of the variety of tissue-specific functions of PMCAs and will highlight the roles these genes play in regulating normal physiological functions and the considerable impact the genes have on human disease. Copyright © 2017 the American Physiological Society.

  12. CO2/HCO3(-)- and calcium-regulated soluble adenylyl cyclase as a physiological ATP sensor. (United States)

    Zippin, Jonathan H; Chen, Yanqiu; Straub, Susanne G; Hess, Kenneth C; Diaz, Ana; Lee, Dana; Tso, Patrick; Holz, George G; Sharp, Geoffrey W G; Levin, Lonny R; Buck, Jochen


    The second messenger molecule cAMP is integral for many physiological processes. In mammalian cells, cAMP can be generated from hormone- and G protein-regulated transmembrane adenylyl cyclases or via the widely expressed and structurally and biochemically distinct enzyme soluble adenylyl cyclase (sAC). sAC activity is uniquely stimulated by bicarbonate ions, and in cells, sAC functions as a physiological carbon dioxide, bicarbonate, and pH sensor. sAC activity is also stimulated by calcium, and its affinity for its substrate ATP suggests that it may be sensitive to physiologically relevant fluctuations in intracellular ATP. We demonstrate here that sAC can function as a cellular ATP sensor. In cells, sAC-generated cAMP reflects alterations in intracellular ATP that do not affect transmembrane AC-generated cAMP. In β cells of the pancreas, glucose metabolism generates ATP, which corresponds to an increase in cAMP, and we show here that sAC is responsible for an ATP-dependent cAMP increase. Glucose metabolism also elicits insulin secretion, and we further show that sAC is necessary for normal glucose-stimulated insulin secretion in vitro and in vivo.

  13. Bilateral Olecranon Bursitis – A Rare Clinical presentation of Calcium Pyrophosphate Crystal Deposition Disease (United States)

    Patel, Jignesh; Girishkumar; Mruthyunjaya; Rupakumar, C. S


    Introduction: Calcium pyrophosphate crystal deposition disease (CPPD) is the most common form of crystal arthropathy second only to gout. Common clinical presentation is an acute monoarticular arthritis commonly occurring in knee joints. We presented a case of bilateral olecranon bursitis in a calcium pyrophosphate crystal deposition disease. Case Report: A 42-year-old female patient is presented with golf ball sized painless swellings in the posterior aspect of her elbows. Elbow joints were clinically normal except for restriction of terminal flexion. X-ray showed mild erosion at the tip of olecranon. Excision biopsy of the swelling showed positive birefringent calcium pyrophosphate dehydrate crystals on the inner wall of the specimen on polarized light microscopy. Conclusion: Bilateral olecranon bursitis may be part of the extraarticular manifestations of calcium pyrophosphate dihydrate crystal deposition disease with good prognosis following in toto bursa excision. PMID:27298934

  14. Bilateral Olecranon Bursitis - A Rare Clinical presentation of Calcium Pyrophosphate Crystal Deposition Disease. (United States)

    Patel, Jignesh; Girishkumar; Mruthyunjaya; Rupakumar, C S


    Calcium pyrophosphate crystal deposition disease (CPPD) is the most common form of crystal arthropathy second only to gout. Common clinical presentation is an acute monoarticular arthritis commonly occurring in knee joints. We presented a case of bilateral olecranon bursitis in a calcium pyrophosphate crystal deposition disease. A 42-year-old female patient is presented with golf ball sized painless swellings in the posterior aspect of her elbows. Elbow joints were clinically normal except for restriction of terminal flexion. X-ray showed mild erosion at the tip of olecranon. Excision biopsy of the swelling showed positive birefringent calcium pyrophosphate dehydrate crystals on the inner wall of the specimen on polarized light microscopy. Bilateral olecranon bursitis may be part of the extraarticular manifestations of calcium pyrophosphate dihydrate crystal deposition disease with good prognosis following in toto bursa excision.

  15. Calcium Intake in the Moroccan Elderly

    Directory of Open Access Journals (Sweden)

    Sebbar El-houcine


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

  16. Calcium Impact on Milk Gels Formation

    DEFF Research Database (Denmark)

    Koutina, Glykeria

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

  17. Normal Psychosexual Development (United States)

    Rutter, Michael


    Normal sexual development is reviewed with respect to physical maturation, sexual interests, sex drive", psychosexual competence and maturity, gender role, object choice, children's concepts of sexual differences, sex role preference and standards, and psychosexual stages. Biologic, psychoanalytic and psychosocial theories are briefly considered.…

  18. Normalized information distance

    NARCIS (Netherlands)

    Vitányi, P.M.B.; Balbach, F.J.; Cilibrasi, R.L.; Li, M.


    The normalized information distance is a universal distance measure for objects of all kinds. It is based on Kolmogorov complexity and thus uncomputable, but there are ways to utilize it. First, compression algorithms can be used to approximate the Kolmogorov complexity if the objects have a string

  19. Normality in Analytical Psychology

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    Steve Myers


    Full Text Available Although C.G. Jung’s interest in normality wavered throughout his career, it was one of the areas he identified in later life as worthy of further research. He began his career using a definition of normality which would have been the target of Foucault’s criticism, had Foucault chosen to review Jung’s work. However, Jung then evolved his thinking to a standpoint that was more aligned to Foucault’s own. Thereafter, the post Jungian concept of normality has remained relatively undeveloped by comparison with psychoanalysis and mainstream psychology. Jung’s disjecta membra on the subject suggest that, in contemporary analytical psychology, too much focus is placed on the process of individuation to the neglect of applications that consider collective processes. Also, there is potential for useful research and development into the nature of conflict between individuals and societies, and how normal people typically develop in relation to the spectrum between individuation and collectivity.

  20. Normalized information distance

    NARCIS (Netherlands)

    Vitányi, P.M.B.; Balbach, F.J.; Cilibrasi, R.L.; Li, M.; Emmert-Streib, F.; Dehmer, M.


    The normalized information distance is a universal distance measure for objects of all kinds. It is based on Kolmogorov complexity and thus uncomputable, but there are ways to utilize it. First, compression algorithms can be used to approximate the Kolmogorov complexity if the objects have a string

  1. Reflectance Reference Targets (OTTER) (United States)

    National Aeronautics and Space Administration — ABSTRACT: Spectral reflectance measurements of flat field targets as reference points representative of pseudo-invariant targets as measured by Spectron SE590...

  2. Reflectance Reference Targets (OTTER) (United States)

    National Aeronautics and Space Administration — Spectral reflectance measurements of flat field targets as reference points representative of pseudo-invariant targets as measured by Spectron SE590 spectrophotometer

  3. "Ser diferente é normal?"/"Being different: is it normal?"

    Directory of Open Access Journals (Sweden)

    Viviane Veras


    Full Text Available A pergunta título deste trabalho retoma o slogan “Ser diferente é normal”, que é parte da campanha criada para uma organização não-governamental que atende portadores de Síndrome de Down. O objetivo é a inclusão social da pessoa com deficiência e o primeiro passo foi propor a inclusão de um grupo de diferentes no grupo dito normal. No vídeo de lançamento da campanha, o diferente, identificado como normal, é mostrado por meio de exemplos – um negro com cabelo black-power, um skin-head, um corpo tatuado, um corpo feminino halterofílico, uma família hippie, uma garota com síndrome de Down. A visão da adolescente dançando reduz, de certo modo, o efeito imaginário que vai além da síndrome, uma vez que apenas o corpo com seus olhinhos puxados se destacam, e não se interrogam questões cognitivas. Minha proposta é refletir sobre o estatuto paradoxal do exemplo, tal como é trabalhado nesse vídeo: se, por definição, um exemplo mostra de fato seu pertencimento a uma classe, pode-se concluir que é exatamente por ser exemplar que ele se encontra fora dela, no exato momento em que a exibe e define. The question in the title of this paper refers to the slogan "ser diferente é normal" ("It´s normal to be different", which is part of a campaign created for a NGO that supports people with Down syndrome. The objective of the campaign is to promote the social inclusion of individuals with Down syndrome, and the first step was to propose the inclusion of a group of "differents" in the so-called normal group. The film launching the campaign shows the different identified as normal by means of examples: a black man exhibiting blackpower haircut, a skin-head, a tattooed body, an over-athletic female body, a hippie family and a girl with Down syndrome. The vision of the dancing teenager lessens the imaginary effect that surpasses the syndrome, since only her body and her little oriental eyes stand out and no cognitive issues are

  4. Exopolysaccharides regulate calcium flow in cariogenic biofilms. (United States)

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


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

  5. Exopolysaccharides regulate calcium flow in cariogenic biofilms.

    Directory of Open Access Journals (Sweden)

    Monika Astasov-Frauenhoffer

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

  6. Catheter based mid-infrared reflectance and reflectance generated absorption spectroscopy (United States)

    Holman, Hoi-Ying N


    A method of characterizing conditions in a tissue, by (a) providing a catheter that has a light source that emits light in selected wavenumbers within the range of mid-IR spectrum; (b) directing the light from the catheter to an area of tissue at a location inside a blood vessel of a subject; (c) collecting light reflected from the location and generating a reflectance spectra; and (d) comparing the reflectance spectra to a reference spectra of normal tissue, whereby a location having an increased number of absorbance peaks at said selected wavenumbers indicates a tissue inside the blood vessel containing a physiological marker for atherosclerosis.

  7. Thoughts on Reflection (Editorial

    Directory of Open Access Journals (Sweden)

    Denise Koufogiannakis


    Full Text Available There has been some acknowledgement in the published literature that reflection is a crucial element of the evidence based library and information practice (EBLIP model we have adopted (Booth 2004, 2006; Grant 2007; Helliwell 2007. As we work through a problem and try to incorporate the best available evidence into our decision making, reflection is required at several stages, including the very identification of the problem through to our assessment of the process itself and what we have learned in order to inform future practice. However, reflection and reflective writing have not fully been integrated into the process we espouse, and very little has been done to look more closely at this element of the model and how it can be integrated into professional learning.In a recently published research article, Sen (2010 confirms the relationship between reflection and several aspects of professional practice. These include critical review and decision making, two aspects that are tied closely to the evidence based process. Sen notes: Students were more likely to show evidence of learning, self‐development, the ability to review issues crucially, awareness of their own mental functions, ability to make decision [sic] and being empowered when they had mastered the art of reflective practice and the more deeply analytical reflective writing. (p.84 EBLIP (the journal tries to incorporate elements of reflection within the articles we publish. While we clearly believe in the need for our profession to do quality research and publish that research so that it can be accessible to practitioners, we also know that research cannot be looked at in isolation. Our evidence summaries are one way of reflecting critically on previously published research, and in the same vein, our classics bring older research studies back to the foreground. This work needs to continue to be discussed and looked at for its impact on our profession.More directly, the Using

  8. Calcium precipitate induced aerobic granulation. (United States)

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


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

  9. Expression of the high capacity calcium-binding domain of calreticulin increases bioavailable calcium stores in plants (United States)

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


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

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

    Directory of Open Access Journals (Sweden)

    Maria C. Machado


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

  11. Inhibition of "spontaneous," notochord-induced, and collagen-induced in vitro somite chondrogenesis by the calcium lonophore, A23187. (United States)

    Kosher, R A


    The present study represents a first step in investigating the possible involvement of calcium (Ca2+) in the stimulation of somite chondrogenesis elicited by extracellular matrix components produced by the embryonic notochord. The ionophore, A23187, a drug that facilitates Ca2+ uptake leading to elevation of cytoplasmic Ca2+ levels, at concentrations of 0.25-1.0 microgram/ml severely impairs "spontaneous" somite chondrogenesis, i.e., inhibits the formation of the small amount of cartilaginous matrix normally formed by embryonic somites in vitro in the absence of inducing tissues. This inhibition is reflected in a considerable reduction in sulfated glycosaminoglycan (GAG) accumulation by A23187-treated somite explants. Furthermore, A23187 inhibits the striking stimulation of cartilaginous matrix formation and sulfated GAG accumulation normally elicited by the embryonic notochord and collagen substrates. In fact, 1.0 microgram/ml of A23187 reduces sulfated GAG accumulation by somites cultured in association with notochord or on collagen to a level even below that accumulated by somites cultured in the absence of these inductive agents. Although these results must be interpreted with caution, they provide incentive for considering a possible regulatory role for Ca2+ in the chondrogenic response of somites to extracellular matrix components produced by the embryonic notochord.

  12. A Closer look at calcium absorption and the benefits and risks of dietary versus supplemental calcium. (United States)

    Booth, Anna; Camacho, Pauline


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

  13. CCN3 and calcium signaling

    Directory of Open Access Journals (Sweden)

    Li Chang Long


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

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

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuerun, E-mail:; Zhang, Yu; Shen, Xiaodong, E-mail:; Wang, Qianqian; Pan, Zhigang


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

  15. Nitrogen enrichment regulates calcium sources in forests. (United States)

    Hynicka, Justin D; Pett-Ridge, Julie C; Perakis, Steven S


    Nitrogen (N) is a key nutrient that shapes cycles of other essential elements in forests, including calcium (Ca). When N availability exceeds ecosystem demands, excess N can stimulate Ca leaching and deplete Ca from soils. Over the long term, these processes may alter the proportion of available Ca that is derived from atmospheric deposition vs. bedrock weathering, which has fundamental consequences for ecosystem properties and nutrient supply. We evaluated how landscape variation in soil N, reflecting long-term legacies of biological N fixation, influenced plant and soil Ca availability and ecosystem Ca sources across 22 temperate forests in Oregon. We also examined interactions between soil N and bedrock Ca using soil N gradients on contrasting basaltic vs. sedimentary bedrock that differed 17-fold in underlying Ca content. We found that low-N forests on Ca-rich basaltic bedrock relied strongly on Ca from weathering, but that soil N enrichment depleted readily weatherable mineral Ca and shifted forest reliance toward atmospheric Ca. Forests on Ca-poor sedimentary bedrock relied more consistently on atmospheric Ca across all levels of soil N enrichment. The broad importance of atmospheric Ca was unexpected given active regional uplift and erosion that are thought to rejuvenate weathering supply of soil minerals. Despite different Ca sources to forests on basaltic vs. sedimentary bedrock, we observed consistent declines in plant and soil Ca availability with increasing N, regardless of the Ca content of underlying bedrock. Thus, traditional measures of Ca availability in foliage and soil exchangeable pools may poorly reflect long-term Ca sources that sustain soil fertility. We conclude that long-term soil N enrichment can deplete available Ca and cause forests to rely increasingly on Ca from atmospheric deposition, which may limit ecosystem Ca supply in an increasingly N-rich world. © 2016 John Wiley & Sons Ltd.

  16. Creation, Identity and Reflection

    Directory of Open Access Journals (Sweden)

    Alina Beatrice Cheşcă


    Full Text Available The paper “Creation, Identity and Reflection” approaches the identification in the “mirror” of reality with creation, in other words seeking the authors’ identity in the reflected images. Reflection means attempting to find oneself, the mirror being the main principle of creation. Many characters become interesting only when they step into the world beyond the mirror, when their faces are doubled by the other self or when their selves are returned by other characters. The narcissistic concept of the mirror, i.e. the reflection in the mirror and the representation of the mirror itself, is a recurrent one in literature, but the reflection of the self which is not the self (as it is a reflection does not necessarily appear in a mirror or in a photograph or portrait. Sometimes, the not-self is returned to the self by another person or character. As far as Oscar Wilde’s theories are concerned, the main idea is that people are interesting for their masks, not for their inner nature. What Wilde calls “inner nature” is the characters’ un-reflected self and the mask is the reflection, the self in the mirror. Some characters’ relationships develop within a fiction that they dramatically try to preserve and protect with the risk of suffering. They refuse to take off the masks which define them in the others’ minds and hearts; the narcissistic individuals (both artists and characters seek and love their own image which they project upon facts, thus creating a fictive realm.

  17. Normal Weight Dyslipidemia

    DEFF Research Database (Denmark)

    Ipsen, David Hojland; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens


    Objective: The liver coordinates lipid metabolism and may play a vital role in the development of dyslipidemia, even in the absence of obesity. Normal weight dyslipidemia (NWD) and patients with nonalcoholic fatty liver disease (NAFLD) who do not have obesity constitute a unique subset...... of individuals characterized by dyslipidemia and metabolic deterioration. This review examined the available literature on the role of the liver in dyslipidemia and the metabolic characteristics of patients with NAFLD who do not have obesity. Methods: PubMed was searched using the following keywords: nonobese......, dyslipidemia, NAFLD, NWD, liver, and metabolically obese/unhealthy normal weight. Additionally, article bibliographies were screened, and relevant citations were retrieved. Studies were excluded if they had not measured relevant biomarkers of dyslipidemia. Results: NWD and NAFLD without obesity share a similar...

  18. Idiopathic Normal Pressure Hydrocephalus

    Directory of Open Access Journals (Sweden)

    Basant R. Nassar BS


    Full Text Available Idiopathic normal pressure hydrocephalus (iNPH is a potentially reversible neurodegenerative disease commonly characterized by a triad of dementia, gait, and urinary disturbance. Advancements in diagnosis and treatment have aided in properly identifying and improving symptoms in patients. However, a large proportion of iNPH patients remain either undiagnosed or misdiagnosed. Using PubMed search engine of keywords “normal pressure hydrocephalus,” “diagnosis,” “shunt treatment,” “biomarkers,” “gait disturbances,” “cognitive function,” “neuropsychology,” “imaging,” and “pathogenesis,” articles were obtained for this review. The majority of the articles were retrieved from the past 10 years. The purpose of this review article is to aid general practitioners in further understanding current findings on the pathogenesis, diagnosis, and treatment of iNPH.

  19. Liquid Carbon Reflectivity at 19 nm

    Directory of Open Access Journals (Sweden)

    Riccardo Mincigrucci


    Full Text Available We hereby report on a pump-probe reflectivity experiment conducted on amorphous carbon, using a 780 nm laser as a pump and a 19 nm FEL emission as probe. Measurements were performed at 50 degrees with respect to the surface normal to have an un-pumped reflectivity higher than 0.5%. A sub-10 fs time synchronization error could be obtained exploiting the nearly jitter-free capabilities of FERMI. EUV FEL-based experiments open the way to study the behaviour of a liquid carbon phase being unaffected by plasma screening.

  20. Gravitational wave sources: reflections and echoes (United States)

    Price, Richard H.; Khanna, Gaurav


    The recent detection of gravitational waves has generated interest in alternatives to the black hole interpretation of sources. A subset of such alternatives involves a prediction of gravitational wave ‘echoes’. We consider two aspects of possible echoes: first, general features of echoes coming from spacetime reflecting conditions. We find that the detailed nature of such echoes does not bear any clear relationship to quasi-normal frequencies. Second, we point out the pitfalls in the analysis of local reflecting ‘walls’ near the horizon of rapidly rotating black holes.

  1. Bioinspired irregularly chirped broadband reflecting multilayers (United States)

    Chiadini, Francesco; Fiumara, Vincenzo; Scaglione, Antonio


    Dielectric multilayers consisting of alternating layers of two different materials with thicknesses irregularly decreasing with depth in the structure are included in the cuticle of some beetles whose shell exhibits broadband reflection in the optical wavelength range. Emulating these structures, we propose and numerically analyze irregularly chirped dielectric multilayers. Analysis was performed using a dedicated genetic algorithm (GA) that searches for the multilayer configurations maximizing the reflection for normal incidence over a large wavelength range. We found that the GA leads to the irregularly chirped reflectors that significantly outperform the regularly chirped ones proposed and analyzed in the literature.

  2. Use of reflective surfaces on roadway embankment

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Doré, Guy


    Temperature measurements have been used to study the effect of two reflective surfaces on a roadway embankment in Forêt Montmorency, Québec, Canada. Both tested materials, Mapelastic (from MAPEI) and Colored Slurry (from Tech-Mix), have lead to a reduction in n-factor and proved to have very good...... adherence characteristics for roadway use. In Kangerlussuaq Airport, western Greenland, ground-penetrating radar (GPR) has been used to compare the variation of the frost table underneath a normal black asphalt surface and a more reflective surface (white paint). The GPR results have shown a clear...

  3. Calcium Lactate addition in Bioconcrete: Effect on Compressive strength and Water penetration

    Directory of Open Access Journals (Sweden)

    Irwan J.M


    Full Text Available This paper presents compressive strength and water penetration of bioconcrete with addition of calcium lactate. Bioconcrete has higher engineering concrete properties and durability compared to normal concrete but the natural production of calcium carbonate is limited to the calcium content in cement. Therefore, additional calcium is added as an additional calcium source to study the influence towards compressive strength and water penetration. The bacteria used in this research are Enterococcus faecalis and Bacillus sp. Calcium lactate was added into concrete mix in concentrations of 0.001mol/l, 0.005mol/l and 0.01mol/l of liquid used. The concentration of bacteria added into the mix is by partial replacement of water used in casting, which are 3% for Enterococcus faecalis and 5% for Bacillus sp. Both compressive strength and water penetration test used cubes of 150mm × 150mm × 150mm. The cubes were tested after 28 days. The result of compressive strength for control is 36 MPa while partial replacement of bacteria yields 38.2 MPa for 3% Enterococcus faecalis and 37.0 MPa for 5% Bacillus sp. Calcium lactate with 0.005 mol/L has the best performance with 42.8 MPa for Enterococcus faecalis and 39.6 MPa for Bacillus sp. Whereas for water penetration, the best concentration of calcium lactate which yielded the lowest water penetration is 0.01 mol/l for both Enterococcus faecalis and Bacillus sp which are 8.7 cm and 8 cm respectively. The addition of calcium lactate into bioconcrete is quite promising for improvement of concrete properties and durability.

  4. Filamin and phospholipase C-ε are required for calcium signaling in the Caenorhabditis elegans spermatheca.

    Directory of Open Access Journals (Sweden)

    Ismar Kovacevic


    Full Text Available The Caenorhabditis elegans spermatheca is a myoepithelial tube that stores sperm and undergoes cycles of stretching and constriction as oocytes enter, are fertilized, and exit into the uterus. FLN-1/filamin, a stretch-sensitive structural and signaling scaffold, and PLC-1/phospholipase C-ε, an enzyme that generates the second messenger IP3, are required for embryos to exit normally after fertilization. Using GCaMP, a genetically encoded calcium indicator, we show that entry of an oocyte into the spermatheca initiates a distinctive series of IP3-dependent calcium oscillations that propagate across the tissue via gap junctions and lead to constriction of the spermatheca. PLC-1 is required for the calcium release mechanism triggered by oocyte entry, and FLN-1 is required for timely initiation of the calcium oscillations. INX-12, a gap junction subunit, coordinates propagation of the calcium transients across the spermatheca. Gain-of-function mutations in ITR-1/IP3R, an IP3-dependent calcium channel, and loss-of-function mutations in LFE-2, a negative regulator of IP3 signaling, increase calcium release and suppress the exit defect in filamin-deficient animals. We further demonstrate that a regulatory cassette consisting of MEL-11/myosin phosphatase and NMY-1/non-muscle myosin is required for coordinated contraction of the spermatheca. In summary, this study answers long-standing questions concerning calcium signaling dynamics in the C. elegans spermatheca and suggests FLN-1 is needed in response to oocyte entry to trigger calcium release and coordinated contraction of the spermathecal tissue.

  5. Toward the optimization of normalized graph Laplacian. (United States)

    Xie, Bo; Wang, Meng; Tao, Dacheng


    Normalized graph Laplacian has been widely used in many practical machine learning algorithms, e.g., spectral clustering and semisupervised learning. However, all of them use the Euclidean distance to construct the graph Laplacian, which does not necessarily reflect the inherent distribution of the data. In this brief, we propose a method to directly optimize the normalized graph Laplacian by using pairwise constraints. The learned graph is consistent with equivalence and nonequivalence pairwise relationships, and thus it can better represent similarity between samples. Meanwhile, our approach, unlike metric learning, automatically determines the scale factor during the optimization. The learned normalized Laplacian matrix can be directly applied in spectral clustering and semisupervised learning algorithms. Comprehensive experiments demonstrate the effectiveness of the proposed approach.

  6. The Role of Calcium in Osteoporosis (United States)

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


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

  7. Assessment of calcium intake by adolescents

    Directory of Open Access Journals (Sweden)

    Cristiane Franco de Oliveira


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

  8. The Risks and Benefits of Calcium Supplementation

    Directory of Open Access Journals (Sweden)

    Chan Soo Shin


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

  9. Normalized Temperature Contrast Processing in Infrared Flash Thermography (United States)

    Koshti, Ajay M.


    The paper presents further development in normalized contrast processing used in flash infrared thermography method. Method of computing normalized image or pixel intensity contrast, and normalized temperature contrast are provided. Methods of converting image contrast to temperature contrast and vice versa are provided. Normalized contrast processing in flash thermography is useful in quantitative analysis of flash thermography data including flaw characterization and comparison of experimental results with simulation. Computation of normalized temperature contrast involves use of flash thermography data acquisition set-up with high reflectivity foil and high emissivity tape such that the foil, tape and test object are imaged simultaneously. Methods of assessing other quantitative parameters such as emissivity of object, afterglow heat flux, reflection temperature change and surface temperature during flash thermography are also provided. Temperature imaging and normalized temperature contrast processing provide certain advantages over normalized image contrast processing by reducing effect of reflected energy in images and measurements, therefore providing better quantitative data. Examples of incorporating afterglow heat-flux and reflection temperature evolution in flash thermography simulation are also discussed.

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


    Eder, Anja; Bading, Hilmar


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

  11. Urinary acidification and urinary excretion of calcium and citrate in women with bilateral medullary sponge kidney

    DEFF Research Database (Denmark)

    Osther, P J; Mathiasen, Helle; Hansen, A B


    Urinary acidification ability, acid-base status and urinary excretion of calcium and citrate were evaluated in 10 women with bilateral medullary sponge kidney (MSK) and in 10 healthy women. Patients with MSK had higher fasting urine pH compared to normal controls (p ... in the mechanism of hypercalciuria and hypocitraturia in patients with medullary sponge kidney.(ABSTRACT TRUNCATED AT 250 WORDS)...

  12. Calcium regulation of androgen receptor expression in the human prostate cancer cell line LNCaP

    NARCIS (Netherlands)

    L.J. Blok (Leen); J.E. Perry; J.K. Lindzey; D.J. Tindall; Y. Gong (Yuewen)


    textabstractElevation of intracellular calcium levels in the presence of normal androgen levels has been implicated in apoptotic prostate cell death. Since the androgen receptor (AR) plays a critical role in the regulation of growth and differentiation of the prostate, it was of

  13. The effect of different diets on urine composition and the risk of calcium oxalate crystallisation in healthy subjects. (United States)

    Siener, Roswitha; Hesse, Albrecht


    The aim of the study was to determine the impact of defined diet modifications on urine composition and the risk of calcium oxalate crystallisation. Ten healthy male volunteers consumed a self-selected diet (SD) for 14 days, and three different standard diets for a period of 5 days each. Whereas the western-type diet (WD) is representative of the usual dietary habits, the normal mixed diet (ND) and the ovo-lacto-vegetarian diet (VD) were calculated according to the requirements. The risk of calcium oxalate crystallisation, calculated as relative supersaturation (EQUIL2) from urine composition, was highest during ingestion of diets SD and WD. The intake of diet ND resulted in a significant decrease in relative supersaturation with calcium oxalate by 58% (p<0.05) compared with diet WD, due to a significant decline in urinary calcium and uric acid excretion and a significant increase in urinary volume, pH-value and citrate excretion. In spite of an increase in urinary pH, citrate and magnesium excretion and a decline in calcium excretion, no further significant decrease in the risk of calcium oxalate crystallisation was observed on diet VD, due to a significant increase in urinary oxalate by 30% (p<0.05) on average. The change of usual dietary habits for a normal mixed diet significantly reduces the risk of calcium oxalate crystallisation. With a vegetarian diet a similar decline in urinary supersaturation with calcium oxalate can be achieved compared to a normal mixed diet. Since urinary oxalate excretion increased significantly, a vegetarian diet without adequate intake of calcium may not be recommended to patients with mild hyperoxaluria.

  14. The Reflective Foundation

    DEFF Research Database (Denmark)

    Lunde Jørgensen, Ida

    Private foundations and cultural philanthropy by élites is viewed with increasing skepticism in recent years, begging the question of the extent to which foundations reflect on their role vis a vis wider societal norms. Through the prism of the New Carlsberg Foundation, financed by the brewery...... Carlsberg A/S, the paper seeks to elucidate the way in which one culturally significant foundation from Denmark has reflected on - and legitimated - its work and investments at critical moments in the past decades. The paper indicates a foundation with a high degree of reflection on the wider societal...... pressures, and position as a mediator between culture and capital. The paper draws inspiration from the institutional logics perspective and Boltanski and Thévenot’s convention theoretical work, to analyse the legitimations pursued by the foundation....

  15. Calcium gluconate supplementation is effective to balance calcium homeostasis in patients with gastrectomy. (United States)

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


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

  16. Influence of calcium sources on microbially induced calcium carbonate precipitation by Bacillus sp. CR2. (United States)

    Achal, Varenyam; Pan, Xiangliang


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

  17. Inhibitors of arachidonate-regulated calcium channel signaling suppress triggered activity induced by the late sodium current. (United States)

    Wolkowicz, Paul; Umeda, Patrick K; Sharifov, Oleg F; White, C Roger; Huang, Jian; Mahtani, Harry; Urthaler, Ferdinand


    Disturbances in myocyte calcium homeostasis are hypothesized to be one cause for cardiac arrhythmia. The full development of this hypothesis requires (i) the identification of all sources of arrhythmogenic calcium and (ii) an understanding of the mechanism(s) through which calcium initiates arrhythmia. To these ends we superfused rat left atria with the late sodium current activator type II Anemonia sulcata toxin (ATXII). This toxin prolonged atrial action potentials, induced early afterdepolarization, and provoked triggered activity. The calmodulin-dependent protein kinase II (CaMKII) inhibitor KN-93 (N-[2-[[[3-(4-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulphon-amide) suppressed ATXII triggered activity but its inactive congener KN-92 (2-[N-(4-methoxy benzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine) did not. Neither drug affected normal atrial contractility. Calcium entry via L-type channels or calcium leakage from sarcoplasmic reticulum stores are not critical for this type of ectopy as neither verapamil ((RS)-2-(3,4-dimethoxyphenyl)-5-{[2-(3,4-dimethoxyphenyl)ethyl]-(methyl)amino}-2-prop-2-ylpentanenitrile) nor ryanodine affected ATXII triggered activity. By contrast, inhibitors of the voltage independent arachidonate-regulated calcium (ARC) channel and the store-operated calcium channel specifically suppressed ATXII triggered activity without normalizing action potentials or affecting atrial contractility. Inhibitors of cytosolic calcium-dependent phospholipase A2 also suppressed triggered activity suggesting that this lipase, which generates free arachidonate, plays a key role in ATXII ectopy. Thus, increased left atrial late sodium current appears to activate atrial Orai-linked ARC and store operated calcium channels, and these voltage-independent channels may be unexpected sources for the arrhythmogenic calcium that underlies triggered activity. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Bading Hilmar


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

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

    Eder, Anja; Bading, Hilmar


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

  20. The Incredible, Embryological Egg: Calcium and Strontium Isotopes Recapitulate Ontogeny (United States)

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


    Embryological development reflects evolutionary history. Understanding the processes of fetal growth is important for curing human birth defects and predicting damage to ecosystems from environmental insults. Tracing enzymatic and hormonal gradients during development, and correlating them to genetic cues dominate modern embryology. Previous work done tracing the mass transfer of elements has generally been limited to isotope spikes in vitro. Natural mass-dependent Ca and Sr isotopic ratios and radiogenic Sr isotopes have the potential to reveal both source and biochemical mechanism information about processes in vivo, but have not previously been extensively explored. The process when a hen lays a fertilized egg that becomes a chick includes formation and dissolution of calcium phosphate (bone) and calcium carbonate (shell). Skulan and DePaolo (1999) showed that chickens have 2% δ44/42Ca between a hen's bones and an egg white; this span represents more than 80% of the entire range of natural Ca isotope variation and illustrates there is significant variation to investigate. A striking feature of archosaurian development that also occurs in many mammals, including humans, is mass transfer of calcium from mother to embryo. The yolk of the domestic hen matures over 7-9 days, but the albumen, shell membranes and shell form in less than 20 hours. Domestic laying hens are at the physiological limit of egg production and selective breeding is no longer an effective method of increasing egg production. 60-75% of the shell's ~1.5 g of calcium comes from dietary sources, while 25-40% comes from the hen's medullary bone. Medullary bone is spicules formed in the marrow of long bones, and is a store of dietary calcium rapidly available for eggshell secretion. During in ovo development, the embryo's skeleton is formed from calcium in the yolk and by bulk dissolution of the eggshell's inner aspect via carbonic anhydrase in a process that has an effect on bone density similar to

  1. Reflections and Interpretations

    DEFF Research Database (Denmark)

    Reflections and Interpretations is an anthology on The Freedom Writers’ methodology. It is an anthology for all those with a professional need for texts explaining, not only how The Freedom Writers’ tools are being used, but also why they work so convincingly well. It is not an anthology of guide......Reflections and Interpretations is an anthology on The Freedom Writers’ methodology. It is an anthology for all those with a professional need for texts explaining, not only how The Freedom Writers’ tools are being used, but also why they work so convincingly well. It is not an anthology...

  2. Reflections on Leadership (United States)


    Reflections on Leadership ROBERT GATES Last year I read Partners in Command, a book by Mark Perry. It is an ac-count of the unique relationship...TITLE AND SUBTITLE Reflections on Leadership 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...Long War, but the Long War is interested in us. How America’s military and civilian leadership grapples with these transcendent issues and dilemmas will

  3. Invisibility via reflecting coating


    Burdzy, Krzysztof; Kulczycki, Tadeusz


    We construct a subset $A$ of the unit disc with the following properties. (i) The set $A$ is the finite union of disjoint line segments. (ii) The shadow of $A$ is arbitrarily close to the shadow of the unit disc in "most" directions. (iii) If the line segments are considered to be mirrors reflecting light according to the classical law of specular reflection then most light rays hitting the set emerge on the other side of the disc moving along a parallel line and shifted by an arbitrarily sma...

  4. Postscript: Delving into Reflection

    Directory of Open Access Journals (Sweden)

    Susan Noffke


    Full Text Available Although, the authors presented an earlier version of the paper, "The Dimensions of Reflection: A Conceptual and Contextual Analysis", at the Annual Meeting of the American Educational Research Association, New Orleans, April, 1988, they did not have a chance to publish the paper till today. This postscript is about why the paper stayed as an “unpublished” conference paper for so long. Editors believe that the authors’ reflection on their academic journey with the paper in the postscript could be seen as an outstanding practical exemplar, a moral-political narrative of how to shape and create well-formed academic lives and identities.

  5. Induced calcium carbonate precipitation using Bacillus species. (United States)

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


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

  6. Calcium excretion in feces of ungulates. (United States)

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


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

  7. Binding of calcium and carbonate to polyacrylates. (United States)

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


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

  8. Altered calcium signaling in cancer cells. (United States)

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


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

  9. Corners of normal matrices

    Indian Academy of Sciences (India)

    λj (BB∗) = λj (I − AA∗) = 1 − λj (AA∗). = 1 − λj (A∗A) = λj (I − A∗A) = λj (C∗C). Thus B and C have the same singular values, and again |||B||| = |||C||| for all unitarily invariant norms. This equality of norms does not persist when we go to arbitrary normal matrices, as we will soon see. From (2) and (4) we get a simple inequality.

  10. Reflective masks for extreme ultraviolet lithography

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Khanh Bao [Univ. of California, Berkeley, CA (United States)


    Extreme ultraviolet lithographic masks are made by patterning multilayer reflective coatings with high normal incidence reflectivity. Masks can be patterned by depositing a patterned absorber layer above the coating or by etching the pattern directly into the coating itself. Electromagnetic simulations showed that absorber-overlayer masks have superior imaging characteristics over etched masks (less sensitive to incident angles and pattern profiles). In an EUVL absorber overlayer mask, defects can occur in the mask substrate, reflective coating, and absorber pattern. Electromagnetic simulations showed that substrate defects cause the most severe image degradation. A printability study of substrate defects for absorber overlayer masks showed that printability of 25 nm high substrate defects are comparable to defects in optical lithography. Simulations also indicated that the manner in which the defects are covered by multilayer reflective coatings can affect printability. Coverage profiles that result in large lateral spreading of defect geometries amplify the printability of the defects by increasing their effective sizes. Coverage profiles of Mo/Si coatings deposited above defects were studied by atomic force microscopy and TEM. Results showed that lateral spread of defect geometry is proportional to height. Undercut at defect also increases the lateral spread. Reductions in defect heights were observed for 0.15 μm wide defect lines. A long-term study of Mo/Si coating reflectivity revealed that Mo/Si coatings with Mo as the top layer suffer significant reductions in reflectivity over time due to oxidation.

  11. Case-control study of breast milk calcium in mothers of children with and without nutritional rickets. (United States)

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


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

  12. Calcium dobesilate: pharmacology and future approaches. (United States)

    Tejerina, T; Ruiz, E


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

  13. Presynaptic calcium dynamics of learning neurons


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


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

  14. Protein-Mediated Precipitation of Calcium Carbonate


    Izabela Polowczyk; Anna Bastrzyk; Marta Fiedot


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

  15. Subthalamic nucleus electrical stimulation modulates calcium activity of nigral astrocytes.

    Directory of Open Access Journals (Sweden)

    Elodie Barat

    Full Text Available BACKGROUND: The substantia nigra pars reticulata (SNr is a major output nucleus of the basal ganglia, delivering inhibitory efferents to the relay nuclei of the thalamus. Pathological hyperactivity of SNr neurons is known to be responsible for some motor disorders e.g. in Parkinson's disease. One way to restore this pathological activity is to electrically stimulate one of the SNr input, the excitatory subthalamic nucleus (STN, which has emerged as an effective treatment for parkinsonian patients. The neuronal network and signal processing of the basal ganglia are well known but, paradoxically, the role of astrocytes in the regulation of SNr activity has never been studied. PRINCIPAL FINDINGS: In this work, we developed a rat brain slice model to study the influence of spontaneous and induced excitability of afferent nuclei on SNr astrocytes calcium activity. Astrocytes represent the main cellular population in the SNr and display spontaneous calcium activities in basal conditions. Half of this activity is autonomous (i.e. independent of synaptic activity while the other half is dependent on spontaneous glutamate and GABA release, probably controlled by the pace-maker activity of the pallido-nigral and subthalamo-nigral loops. Modification of the activity of the loops by STN electrical stimulation disrupted this astrocytic calcium excitability through an increase of glutamate and GABA releases. Astrocytic AMPA, mGlu and GABA(A receptors were involved in this effect. SIGNIFICANCE: Astrocytes are now viewed as active components of neural networks but their role depends on the brain structure concerned. In the SNr, evoked activity prevails and autonomous calcium activity is lower than in the cortex or hippocampus. Our data therefore reflect a specific role of SNr astrocytes in sensing the STN-GPe-SNr loops activity and suggest that SNr astrocytes could potentially feedback on SNr neuronal activity. These findings have major implications given the

  16. Serum ionised calcium and cardiovascular disease in 45-years old men and women followed for 18 years

    DEFF Research Database (Denmark)

    Ogard, Christina Gerlach; Petersen, Janne; Jørgensen, Torben


    a health survey in 1981 in Copenhagen had ionised serum calcium and different cardiovascular risk factors measured. The participants were followed until 1999 in The National Hospital Patients Registry and The National Death Registry in Denmark regarding the diagnosis ischemic heart disease (IHD......High level of total serum calcium within the normal range has been associated with increased cardiovascular risk. We wanted to evaluate whether the physiological active ionised form of calcium also was a risk factor for cardiovascular disease (CVD). Methods: A total of 974 participants from...

  17. Calcium Unresponsive Hypocalcemic Tetany: Gitelman Syndrome with Hypocalcemia

    Directory of Open Access Journals (Sweden)

    Madhav Desai


    Full Text Available Introduction. Gitelman’s syndrome (GS is autosomal recessive renal tubular disorder characterized by hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis, and hyperreninemic hyperaldosteronism. It is usually associated with normal serum calcium. We report a patient presented with hypocalcemic tetany, and evaluation showed Gitelman’s syndrome with hypocalcemia. Case Report. A 28-year-old woman presented with cramps of the arms, legs, fatigue, and carpal spasms of one week duration. She has history of similar episodes on and off for the past two years. Her blood pressure was 98/66 mmHg. Chvostek’s sign and Trousseau’s sign were positive. Evaluation showed hypokalemia, hypocalcemia, hypomagnesemia, metabolic alkalosis, and hypocalciuria. Self-medication, diuretic use, laxative abuse, persistent vomiting, and diarrhoea were ruled out. Urinary prostaglandins and genetic testing could not be done because of nonavailability. To differentiate Gitelman syndrome from Bartter’s syndrome (BS, thiazide loading test was done. It showed blunted fractional chloride excretion. GS was confirmed and patient was treated with spironolactone along with magnesium, calcium, and potassium supplementation. Symptomatically, she improved and did not develop episodes of tetany again. Conclusion. In tetany patient along with serum calcium measurement, serum magnesium, serum potassium, and arterial blood gases should be measured. Even though hypocalcemia in Gitelman syndrome is rare, it still can occur.

  18. Magnesium: Effect on ocular health as a calcium channel antagonist

    Directory of Open Access Journals (Sweden)

    Şafak Korkmaz


    Full Text Available Magnesium is the physiologic calcium channel blocker,involving in many different metabolic processes by maintainingcell membrane function, modulating smooth musclecontraction and influencing enzymatic activities. Magnesiumhas been shown to increase blood flow to tissuesby modifying endothelial function via endothelin-1 (ET-1and nitric Oxide (NO pathways. Magnesium also exhibitsneuroprotective role by blocking N-methyl-D-aspartate(NMDA receptor related calcium influx and by inhibitingthe release of glutamate, hence protects the cell againstoxidative stress and apoptosis. Both increase in bloodflow and its neuroprotective effect make magnesium agood candidate for glaucoma studies. Magnesium hasbeen shown to decrease oxidative stress and apoptosisin retinal tissue and to have retinal ganglion cell sparingeffect. A series of studies has been conducted aboutmagnesium could decrease insulin resistance in diabeticpatients, ease glycemia control and prevent diabetic retinopathy.Magnesium is found to be critically important inmaintaining normal ionic homeostasis of lens. Magnesiumdeficiency has been shown to cause increased lenticularoxidative stress and ionic imbalance in the lens so triggercataractogenesis. J Clin Exp Invest 2013; 4 (2: 244-251Key words: Magnesium, calcium channel blockage,glaucoma, neuroprotection, diabetic retinopathy, cataract

  19. Mechanical Properties of a Calcium Dietary Supplement, Calcium Fumarate Trihydrate. (United States)

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


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

  20. Calcium dependence of inactivation of calcium release from the sarcoplasmic reticulum in skeletal muscle fibers. (United States)

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


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

  1. Self-Reflection

    DEFF Research Database (Denmark)

    Fausing, Bent


    Reflecting has a double meaning, mirroring and thinking. The seminar will investigate how these two meanings intervene in each other. As we perceive we are already in pre-refectory state, and thinking involves a lot of not only thoughts, but also of senses and sensing, wherefrom our thoughts star...

  2. Value reflected health education

    DEFF Research Database (Denmark)

    Wistoft, Karen; Nordentoft, Helle Merete


    This article examines the impact of a value-reflected approach in health education by demonstrating the nature of professional competence development connected to this approach. It is based on findings from two three-year health educational development projects carried out by school health nurses...... develop pedagogical competences in health education improving school childrens’ health....

  3. Reflection on Political Representation

    DEFF Research Database (Denmark)

    Kusche, Isabel


    This article compares how Members of Parliament in the United Kingdom and Ireland reflect on constituency service as an aspect of political representation. It differs from existing research on the constituency role of MPs in two regards. First, it approaches the question from a sociological...

  4. Reflections on Software Research

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 8. Reflections on Software Research. Dennis M Ritchie. Classics Volume 17 Issue 8 August 2012 pp 810-816. Fulltext. Click here to view fulltext PDF. Permanent link: Author Affiliations.

  5. Reflections on "La Esperanza" (United States)

    Cortez, Anita


    The author was recently asked to reflect on her "educational journey." As far as she can remember she has been hungry to learn. A friend once described her as having "hambres atrasadas," which he described as a kind of "hunger nipping at her heels." It goes back, of course, to her parents: Her father's and her early…

  6. Wave Reflection Model Tests

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Larsen, Brian Juul

    The investigation concerns the design of a new internal breakwater in the main port of Ibiza. The objective of the model tests was in the first hand to optimize the cross section to make the wave reflection low enough to ensure that unacceptable wave agitation will not occur in the port. Secondly...... wave overtopping was studied as well....

  7. Teaching as Reflective Practice. (United States)

    Kennedy, Rosa L.; Wyrick, Amy M.

    This paper describes a method of reflective practice called "critical incident" which was used to examine teacher trainees' educational assumptions. A qualitative case study of one fifth-year teaching intern (Amy) at the University of Tennessee represents the experience of seven other master's level students already practicing within the…

  8. Protein-Mediated Precipitation of Calcium Carbonate. (United States)

    Polowczyk, Izabela; Bastrzyk, Anna; Fiedot, Marta


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

  9. Diuretics and disorders of calcium homeostasis. (United States)

    Grieff, Marvin; Bushinsky, David A


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


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


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

  11. Molecular imaging of in vivo calcium ion expression in area postrema of total sleep deprived rats: Implications for cardiovascular regulation by TOF-SIMS analysis (United States)

    Mai, Fu-Der; Chen, Li-You; Ling, Yong-Chien; Chen, Bo-Jung; Wu, Un-In; Chang, Hung-Ming


    Excessive calcium influx in chemosensitive neurons of area postrema (AP) is detrimental for sympathetic activation and participates in the disruption of cardiovascular activities. Since total sleep deprivation (TSD) is a stressful condition known to harm the cardiovascular function, the present study is aimed to determine whether the in vivo calcium expression in AP would significantly alter following TSD by the use of time-of-flight secondary ion mass spectrometry (TOF-SIMS) and calretinin (a specific calcium sensor protein in AP neurons) immunohistochemistry. The results indicated that in normal rats, the calcium intensity was estimated to be 0.5 × 10 5 at m/ z 40.08. However, following TSD, the intensity for calcium ions was greatly increased to 1.2 × 10 5. Molecular imaging revealed that after TSD, various strongly expressed calcium signals were distributed throughout AP with clear identified profiles instead of randomly scattered within this region in normal rats. Immunohistochemical staining corresponded well with ionic image in which a majority of calcium-enriched gathering co-localized with calretinin positive neurons. The functional significance of TSD-induced calcium augmentation was demonstrated by increased heart rate and mean arterial pressure, clinical markers for cardiovascular dysfunction. Considering AP-mediated sympathetic activation is important for cardiovascular regulation, exaggerated calcium influx in AP would render this neurocircuitry more vulnerable to over-excitation, which might serve as the underlying mechanism for the development of TSD-relevant cardiovascular deficiency.

  12. The Electronic Structure of Calcium

    DEFF Research Database (Denmark)

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


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

  13. Reflectance Hashing for Material Recognition


    Zhang, Hang; Dana, Kristin; Nishino, Ko


    We introduce a novel method for using reflectance to identify materials. Reflectance offers a unique signature of the material but is challenging to measure and use for recognizing materials due to its high-dimensionality. In this work, one-shot reflectance is captured using a unique optical camera measuring {\\it reflectance disks} where the pixel coordinates correspond to surface viewing angles. The reflectance has class-specific stucture and angular gradients computed in this reflectance sp...

  14. Complex refractive index measurements for BaF 2 and CaF 2 via single-angle infrared reflectance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kelly-Gorham, Molly Rose K.; DeVetter, Brent M.; Brauer, Carolyn S.; Cannon, Bret D.; Burton, Sarah D.; Bliss, Mary; Johnson, Timothy J.; Myers, Tanya L.


    We have re-investigated the optical constants n and k for the homologous series of inorganic salts barium fluoride (BaF2) and calcium fluoride (CaF2) using a single-angle near-normal incidence reflectance device in combination with a calibrated Fourier transform infrared (FTIR) spectrometer. Our results are in good qualitative agreement with most previous works. However, certain features of the previously published data near the reststrahlen band exhibit distinct differences in spectral characteristics. Notably, our measurements of BaF2 do not include a spectral feature in the ~250 cm-1 reststrahlen band that was previously published. Additionally, CaF2 exhibits a distinct wavelength shift relative to the model derived from previously published data. We confirmed our results with recently published works that use significantly more modern instrumentation and data reduction techniques

  15. Treatment of secondary hyperparathyroidism by high calcium diet is associated with enhanced resistance artery relaxation in experimental renal failure. (United States)

    Jolma, Pasi; Kööbi, Peeter; Kalliovalkama, Jarkko; Saha, Heikki; Fan, Meng; Jokihaara, Jarkko; Moilanen, Eeva; Tikkanen, Ilkka; Pörsti, Ilkka


    Vasorelaxation is impaired in renal failure (RF) and hypertension. A high calcium diet enhances vasodilatation and reduces blood pressure in experimental hypertension. Oral calcium salts are used as phosphate binders in RF. However, the effect of increased calcium intake on arterial tone in RF is unknown. We investigated the influence of an 8-week high calcium diet (0.3 vs 3.0%) on resistance artery tone in 5/6 nephrectomized (NTX) rats. Calcium was supplemented as carbonate salt, blood pressure measured by tail-cuff, urine collected in metabolic cages, and samples taken for blood chemistry and parathyroid hormone (PTH). Functional studies of isolated third-order branches of the mesenteric artery in vitro were performed using the Mulvany multimyograph. Plasma urea was elevated 1.6-fold and systolic blood pressure by 10 mmHg after NTX, while increased calcium intake was without effect on these variables. Plasma PTH and phosphate were raised following NTX, and suppressed by high calcium diet. Vasorelaxations induced by K(+) channel agonists 11,12-epoxyeicosatrienoic acid and levcromakalim were impaired after NTX. Vasorelaxation induced by acetylcholine was also reduced following NTX, and experiments with N(G)-nitro-L-arginine methyl ester, diclofenac and charybdotoxin + apamin suggested that the K(+) channel-mediated component of endothelium-dependent relaxation was deficient after NTX. Increased calcium intake corrected all impairments of vasodilatation in NTX rats. Deficient vasorelaxation via K(+) channels was normalized by high calcium diet in experimental RF. This effect was independent of the degree of renal impairment and blood pressure, but was associated with improved calcium metabolism: plasma levels of PTH and phosphate were decreased and ionized calcium was increased.

  16. Reflectivity-modulated grating-mirror

    DEFF Research Database (Denmark)


    The invention relates to vertical cavity lasers (VCL) incorporating a reflectivity-modulated grating mirror (1) for modulating the laser output. A cavity is formed by a bottom mirror (4), an active region (3), and an outcoupling top grating mirror (1) formed by a periodic refractive index grating...... region in a layer structure comprising a p- and a n-doped semiconductor layer with an electrooptic material layer (12) arranged there between. The grating region comprises a grating structure formed by periodic perforations to change the refractive index periodically in directions normal...... to the oscillation axis. A modulated voltage (91) is applied in reverse bias between the n- and p-doped layers to modulate the refractive index of the electrooptic material layer (12) and thereby the reflectivity spectrum of the grating mirror (1). The reflectivity of the grating mirror (1) can be modulated between...

  17. Calcium and magnesium levels in isolated mitochondria from human cardiac biopsies. (United States)

    Saetersdal, T; Engedal, H; Røli, J; Myklebust, R


    A non-enzymatic method is presented for isolating mitochondria from small-sized human cardiac samples, including ventricular needle biopsies of 15-25 mg of wet weight. Electron microscopy demonstrates that these fractions are rich in structurally well preserved mitochondria. Calcium and magnesium levels of fractions are determined by atomic absorption flame spectroscopy. Comparative analyses are made in similar fractions of the mouse ventricle. Calcium concentrations of mitocondria isolated in the presence of ruthenium red do not differ significantly between the human auricle and ventricle, averaging 61 nmol Ca/mg protein and 68 nmol Ca/mg protein, respectively. Mitochondrial calcium level is lower in the mouse ventricular fractions, averaging 7 nmol Ca/mg protein. Mitochondrial magnesium amounts to slightly less than 60% of the calcium levels in the human heart, while it exceeds the calcium level by more than 100 per cent in the mouse heart. There is no significant difference of mitochondrial calcium between normal auricles, and, auricles of patients with increased right atrial mean pressure and/or volume overload.

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

    NARCIS (Netherlands)

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


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

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

    NARCIS (Netherlands)

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


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

  20. Phosphorus and Calcium Metabolism in Postmenopausal Women with Diabetes Mellitus: Effects of the Type and Duration of the Disease, Time of Menopause and Body Mass

    Directory of Open Access Journals (Sweden)

    M.L. Kyryliuk


    Full Text Available The article deals with the impact of diabetes mellitus (DM on the phosphorus and calcium metabolism in postmenopausal women, depending on the type and duration of the disease, duration of menopause, body mass and type of hypoglycemic therapy. The state of phosphorus and calcium metabolism in 86 women with type 1 DM (13 patients and type 2 DM (73 patients was studied. In all patients, the concentration of calcium and phosphorus in the blood was within normal limits. It was found that the concentration of ionized calcium, total calcium and inorganic phosphorus in the blood can not be the main criterion for the state of bone mineral density in postmenopausal women with DM. Sulfonylureas and insulin in combination with biguanides have no effect on the status of phosphorus and calcium metabolism in postmenopausal women with type 2 DM.

  1. An experimental study of mandibular fracture wound healing in the calcium deficient rat

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoon; Wang, Eui Hwan; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyunghee University, Seoul (Korea, Republic of)


    The purpose of this study was to investigate effects of osteoporosis on fracture wound healing in the calcium deficient rat. To research the experiment some ten-week old Wistar strain rats with approximately 300 gms weight were selected. Then, the rats were divided into two groups : Normal diet group (rats given a normal diet before and after bone fracture) and Low calcium diet group (rats given a low calcium diet before and after bone fracture). Both groups had been provided with each diet for three weeks. When the rats became thirteen weeks old, the mandibular angle of rats in both groups was artificially fractured for test. The healing of fracture wounds was reviewed by using soft x-ray radiography and {sup 99m}Tc-MDP bone scan and also histopathologic examination. The obtained results were as follows : 1. The radiolucency of the fracture site for the Normal diet group started to decrease from the 14th day since the experiment was made, while the Low calcium diet group began decrease in the radiolucency from the 21st day of the experiment . The radiolucency for the normal diet group disappeared at the 42nd day, but one for the Low calcium diet group disappeared at the 56th day of the experiment. 2. The highest uptake rate of {sup 99m}Tc-MDP stood at the 14th day of the experiment in the Normal diet group and the Low calcium diet group's maximum rate was recorded at the 21st day of the experiment. These both groups were gradually experiencing decrease in the uptake rate as the experiment time was going on. However, the uptake rate in the Low calcium diet group was lower than one in the Normal diet group. 3. For the Normal diet group, the newly formed trabecular, which were similar to one of the surrounding bone, were seen at the 42nd day of the experiment. On the other hand, the Low claium diet group showed at the 56th day of the experiment that the osteoporotic findings looked weak, irregular trabecular, and also large bone marrow space were observed

  2. Plasma membrane calcium pump and sodium-calcium exchanger in maintenance and control of calcium concentrations in platelets. (United States)

    Juska, Alfonsas


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

  3. Extracting infrared absolute reflectance from relative reflectance measurements. (United States)

    Berets, Susan L; Milosevic, Milan


    Absolute reflectance measurements are valuable to the optics industry for development of new materials and optical coatings. Yet, absolute reflectance measurements are notoriously difficult to make. In this paper, we investigate the feasibility of extracting the absolute reflectance from a relative reflectance measurement using a reference material with known refractive index.

  4. Dissolved strontium and calcium levels in the tropical Indian Ocean (United States)

    Steiner, Zvi; Sarkar, Amit; Turchyn, Alexandra


    the section Sr/Ca ratios increase significantly. This finding is opposite to expectations based on plankton net tows collected during the cruise, where we found high abundance of acantharia in the southern parts of the section, while the preferential enrichment in strontium is in the northern part of the section. When potential alkalinity is calculated by correcting the normalized total alkalinity for the effects of nutrient accumulation below the thermocline, we observe that the increase in alkalinity begins at 100 m, well above the aragonite saturation horizon. The total change in dissolved calcium concentrations between 0 and 2000 m is similar to the total change in potential alkalinity yet their profiles do not overlap; calcium concentrations increase faster than total alkalinity between 100-1000 m and the gap is closed between 1000-1500 m. This suggests an additional, unaccounted process that is likely occurring in the Red Sea and Persian Gulf, the intermediate water sources of this region.

  5. Pseudogout and Calcium Pyrophosphate Disease

    Directory of Open Access Journals (Sweden)

    Andrew Williamson


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

  6. Reflecting differently. New dimensions: reflection-before-action and reflection-beyond-action

    Directory of Open Access Journals (Sweden)

    Sharon Edwards


    Full Text Available Background: This article attempts to move reflection forward from a process currently identified as two-dimensional (reflection-in-action and reflection-on-action to a four-dimensional process by adding reflection-before-action and reflection-beyond-action. In nursing clinical practice reflection-in-action is the required skill, but reflection-on-action is often advocated in nurse education through the application of reflective models in assignments. Nurse education draws on practice but generally, when using reflective practice, applies some sort of method or guide to direct student learning. This approach does not fully recognise that much learning arises from individual students’ own clinical practice experiences. The notion that undertaking reflection-on-action assignments develops the reflection-in-action skills needed for clinical practice is not demonstrated in the literature. Yet it is reflection-in-action that can aid professional practice and enhance learning. This is why it is important to explore a broader approach to reflection. Aims: To show more value can be gained from engaging with two additional dimensions of reflection – those of reflection-before-action and reflection-beyond-action, and to demonstrate how these can be linked to the better known concepts reflection-in-action and reflection-on-action, and to the author’s doctoral research, practice experience and practice development activities. Findings: Nursing reflection-on-action is widely used for a range of purposes, but restricting reflection in nurse education to this neglects the full potential of a broader application of reflection. A lifelong application of reflection can demonstrate its value for a more holistic and practical development approach. Conclusions: This article expands reflection and provides two additional dimensions. Instead of identifying reflection as two-dimensional, this article proposes that reflection can better serve learning from practice

  7. Calcium signaling in plant cells in microgravity (United States)

    Kordyum, E.

    Changes in the intracellular Ca 2 + concentration in altered gravity (microgravity and clinostating) evidence that Ca2 + signaling can play a fundamental role in biological effects of microgravity. Calcium as a second messenger is known to play a crucial role in stimulus - response coupling for many plant cellular signaling pathways. Its messenger functions are realized by transient changes in the cytosolic ion concentration induced by a variety of internal and external stimuli such as light, hormones, temperature, anoxia, salinity, and gravity. Although the first data on the changes in the calcium balance in plant cells under the influence of altered gravity have appeared in eighties, a review highlighting the performed research and the possible significance of such Ca 2 + changes in the structural and metabolic rearrangements of plant cells in altered gravity is still lacking. In this paper, an attempt was made to summarize the available experimental results and to consider some hypotheses in this field of research. It is proposed to distinguish between cell gravisensing and cell graviperception; the former is related to cell structure and metabolism stability in the gravitational field and their changes in microgravity (cells not specialized to gravity perception), the latter is related to active use of a gravitational stimulus by cells presumably specialized to gravity perception for realization of normal space orientation, growth, and vital activity (gravitropism, gravitaxis) in plants. The main experimental data concerning both redistribution of free Ca 2 + ions in plant cell organelles and the cell wall, and an increase in the intracellular Ca 2+ concentration under the influence of altered gravity are presented. Based on the gravitational decompensation hypothesis, the consequence of events occurring in gravis ensing cells not specialized to gravity perception under altered gravity are considered in the following order: changes in the cytoplasmic membrane

  8. New spatial upscaling methods for multi-point measurements: From normal to p-normal (United States)

    Liu, Feng; Li, Xin


    Careful attention must be given to determining whether the geophysical variables of interest are normally distributed, since the assumption of a normal distribution may not accurately reflect the probability distribution of some variables. As a generalization of the normal distribution, the p-normal distribution and its corresponding maximum likelihood estimation (the least power estimation, LPE) were introduced in upscaling methods for multi-point measurements. Six methods, including three normal-based methods, i.e., arithmetic average, least square estimation, block kriging, and three p-normal-based methods, i.e., LPE, geostatistics LPE and inverse distance weighted LPE are compared in two types of experiments: a synthetic experiment to evaluate the performance of the upscaling methods in terms of accuracy, stability and robustness, and a real-world experiment to produce real-world upscaling estimates using soil moisture data obtained from multi-scale observations. The results show that the p-normal-based methods produced lower mean absolute errors and outperformed the other techniques due to their universality and robustness. We conclude that introducing appropriate statistical parameters into an upscaling strategy can substantially improve the estimation, especially if the raw measurements are disorganized; however, further investigation is required to determine which parameter is the most effective among variance, spatial correlation information and parameter p.

  9. Spatiotemporal intracellular calcium dynamics during cardiac alternans (United States)

    Restrepo, Juan G.; Karma, Alain


    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.

  10. Src Dependent Pancreatic Acinar Injury Can Be Initiated Independent of an Increase in Cytosolic Calcium.

    Directory of Open Access Journals (Sweden)

    Vivek Mishra

    Full Text Available Several deleterious intra-acinar phenomena are simultaneously triggered on initiating acute pancreatitis. These culminate in acinar injury or inflammatory mediator generation in vitro and parenchymal damage in vivo. Supraphysiologic caerulein is one such initiator which simultaneously activates numerous signaling pathways including non-receptor tyrosine kinases such as of the Src family. It also causes a sustained increase in cytosolic calcium- a player thought to be crucial in regulating deleterious phenomena. We have shown Src to be involved in caerulein induced actin remodeling, and caerulein induced changes in the Golgi and post-Golgi trafficking to be involved in trypsinogen activation, which initiates acinar cell injury. However, it remains unclear whether an increase in cytosolic calcium is necessary to initiate acinar injury or if injury can be initiated at basal cytosolic calcium levels by an alternate pathway. To study the interplay between tyrosine kinase signaling and calcium, we treated mouse pancreatic acinar cells with the tyrosine phosphatase inhibitor pervanadate. We studied the effect of the clinically used Src inhibitor Dasatinib (BMS-354825 on pervanadate or caerulein induced changes in Src activation, trypsinogen activation, cell injury, upstream cytosolic calcium, actin and Golgi morphology. Pervanadate, like supraphysiologic caerulein, induced Src activation, redistribution of the F-actin from its normal location in the sub-apical area to the basolateral areas, and caused antegrade fragmentation of the Golgi. These changes, like those induced by supraphysiologic caerulein, were associated with trypsinogen activation and acinar injury, all of which were prevented by Dasatinib. Interestingly, however, pervanadate did not cause an increase in cytosolic calcium, and the caerulein induced increase in cytosolic calcium was not affected by Dasatinib. These findings suggest that intra-acinar deleterious phenomena may be initiated

  11. A free calcium wave traverses the activating egg of the medaka, Oryzias latipes

    Energy Technology Data Exchange (ETDEWEB)

    Gilkey, J.C.; Jaffee, L.E.; Ridgway, E.B.; Reynolds, G.T.


    Aequorin injected eggs of the medaka (a fresh water fish) show an explosive rise in free calcium during fertilization, which is followed by a slow return to the resting level. Image intensification techniques now show a spreading wave of high free calcium during fertilization. The wave starts at the animal pole (where the sperm enters) and then traverses the egg as a shallow, roughly 20/sup 0/-wide band which vanishes at the antipode some minutes later. The peak free calcium concentration within this moving band is estimated to be about 30 (perhaps 100 to 1,000 times the resting level). Eggs activated by ionophore A23187 may show multiple initiation sites. The resulting multiple waves never spread throuh each other, rather, they fuse upon meeting so as to form spreading waves of compound origin. The fertilization wave is nearly independent of extracellular calcium because it is only slightly slowed (by perhaps 15%) in a medium containing 5mM ethylene glycol-bis(..beta..-aminoethyl ether)N,N'-tetraacetic acid (EGTA) and no deliberately added calcium. It is also independent of the large cortical vesicles, which may be centrifugally displaced. Normally, however, it distinctly precedes the well-known wave of cortical vesicle exocytosis. We conclude that the fertilization wave in the medaka egg is propagated by calcium-stimulated calcium release, primarily from some internal sources other than the large cortical vesicles. A comparison of the characteristics of the exocytotic wave in the medaka with that in other eggs, particularly in echinoderm eggs, suggests that such a propagated calcium wave is a general feature of egg activation.

  12. Clinical linguistics: conversational reflections. (United States)

    Crystal, David


    This is a report of the main points I made in an informal "conversation" with Paul Fletcher and the audience at the 14th ICPLA conference in Cork. The observations arose randomly, as part of an unstructured 1-h Q&A, so they do not provide a systematic account of the subject, but simply reflect the issues which were raised by the conference participants during that time.

  13. Landsat surface reflectance data (United States)



    Landsat satellite data have been produced, archived, and distributed by the U.S. Geological Survey since 1972. Users rely on these data for historical study of land surface change and require consistent radiometric data processed to the highest science standards. In support of the guidelines established through the Global Climate Observing System, the U.S. Geological Survey has embarked on production of higher-level Landsat data products to support land surface change studies. One such product is Landsat surface reflectance.

  14. Calcium Blood Test: MedlinePlus Lab Test Information (United States)

    ... this page: Calcium Blood Test To use the sharing features on this page, please enable JavaScript. What is a Calcium Blood Test? A calcium blood test measures the ...

  15. Normalized GNSS Interference Pattern Technique for Altimetry

    Directory of Open Access Journals (Sweden)

    Miguel Angel Ribot


    Full Text Available It is well known that reflected signals from Global Navigation Satellite Systems (GNSS can be used for altimetry applications, such as monitoring of water levels and determining snow height. Due to the interference of these reflected signals and the motion of satellites in space, the signal-to-noise ratio (SNR measured at the receiver slowly oscillates. The oscillation rate is proportional to the change in the propagation path difference between the direct and reflected signals, which depends on the satellite elevation angle. Assuming a known receiver position, it is possible to compute the distance between the antenna and the surface of reflection from the measured oscillation rate. This technique is usually known as the interference pattern technique (IPT. In this paper, we propose to normalize the measurements in order to derive an alternative model of the SNR variations. From this model, we define a maximum likelihood estimate of the antenna height that reduces the estimation time to a fraction of one period of the SNR variation. We also derive the Cramér–Rao lower bound for the IPT and use it to assess the sensitivity of different parameters to the estimation of the antenna height. Finally, we propose an experimental framework, and we use it to assess our approach with real GPS L1 C/A signals.

  16. Normalized GNSS interference pattern technique for altimetry. (United States)

    Ribot, Miguel Angel; Kucwaj, Jean-Christophe; Botteron, Cyril; Reboul, Serge; Stienne, Georges; Leclère, Jérôme; Choquel, Jean-Bernard; Farine, Pierre-André; Benjelloun, Mohammed


    It is well known that reflected signals from Global Navigation Satellite Systems (GNSS) can be used for altimetry applications, such as monitoring of water levels and determining snow height. Due to the interference of these reflected signals and the motion of satellites in space, the signal-to-noise ratio (SNR) measured at the receiver slowly oscillates. The oscillation rate is proportional to the change in the propagation path difference between the direct and reflected signals, which depends on the satellite elevation angle. Assuming a known receiver position, it is possible to compute the distance between the antenna and the surface of reflection from the measured oscillation rate. This technique is usually known as the interference pattern technique (IPT). In this paper, we propose to normalize the measurements in order to derive an alternative model of the SNR variations. From this model, we define a maximum likelihood estimate of the antenna height that reduces the estimation time to a fraction of one period of the SNR variation. We also derive the Cramér-Rao lower bound for the IPT and use it to assess the sensitivity of different parameters to the estimation of the antenna height. Finally, we propose an experimental framework, and we use it to assess our approach with real GPS L1 C/A signals.

  17. Rates of calcium carbonate removal from soils.

    NARCIS (Netherlands)

    Breemen, van N.; Protz, R.


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

  18. Calcium and M'yocardial Infarction

    African Journals Online (AJOL)


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

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

    Directory of Open Access Journals (Sweden)

    R. Mänd


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

  20. 21 CFR 182.8223 - Calcium pyrophosphate. (United States)


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

  1. 21 CFR 182.8217 - Calcium phosphate. (United States)


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

  2. Elements from chlorine to calcium nuclear reactions

    CERN Document Server

    Kunz, Wunibald


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

  3. Role of calcium in selenium cataract. (United States)

    Shearer, T R; David, L L

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

  4. Adding calcium improves lithium ferrite core (United States)

    Lessoff, H.


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

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

    DEFF Research Database (Denmark)

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


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

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

    African Journals Online (AJOL)

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

  7. Dairy Dilemma: Are You Getting Enough Calcium? (United States)

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


    NARCIS (Netherlands)



    Diet is a major determinant of colon cancer risk. Calcium may protect against colon cancer, presumably by binding cytotoxic bile acids and fatty acids. Numerous studies support this proposition. In subjects at risk for colon cancer oral calcium supplementation has been shown to reduce rectal

  9. Calcium Impact on Milk Gels Formation

    DEFF Research Database (Denmark)

    Koutina, Glykeria

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

  10. Bespuiten met calcium kan neusrot voorkomen

    NARCIS (Netherlands)

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


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

  11. Influence of differences in the hardness and calcium content of diets on the growth of craniofacial bone in rats. (United States)

    Goto, Shota; Fujita, Yuko; Hotta, Maika; Sugiyama, Ayako; Maki, Kenshi


    To examine the effects of a soft diet and a low-calcium diet on the craniofacial growth and bone architectures of the maxilla and mandible. Male rats (n  =  20, 3 weeks old) were divided into four groups. Ten rats were given a normal-calcium diet, and the other rats were given a low-calcium diet. Each group was then divided into two subgroups, which were fed a hard or a soft diet. After 4 weeks, craniofacial growth and architecture in maxillary and mandibular bone were analyzed using cephalometry, micro-computed tomography, and histopathology. The low-calcium diet had no effect on serum calcium levels. The low-calcium diet had the greatest effect on craniofacial bone growth, while the soft diet affected the growth of several bone sites that are attached to the masseter muscle. A low-calcium diet resulted in the deterioration of the connectivity of the trabeculae in the furcation region of the maxillary and mandibular first molar, while a soft diet resulted in the diffuse disappearance of trabeculae in the central part of the furcation regions. In the midpalatal suture, a low-calcium diet resulted in inhibition of cartilaginous ossification, although the midpalatal suture had a normal cartilaginous structure. A soft diet resulted in narrower cartilage cell layers in the midpalatal suture. We demonstrated that a low-calcium diet and a soft diet resulted in a deterioration of bone structures in both the maxilla and in the mandible; however, the mechanisms underlying these effects differed between diets.

  12. Estimating surface reflectance from Himawari-8/AHI reflectance channels Using 6SV (United States)

    Lee, Kyeong-sang; Choi, Sungwon; Seo, Minji; Seong, Noh-hun; Han, Kyung-soo


    TOA (Top Of Atmospheric) reflectance observed by satellite is modified by the influence of atmosphere such as absorbing and scattering by molecular and gasses. Removing TOA reflectance attenuation which is caused by the atmospheric is essential. surface reflectance with compensated atmospheric effects used as important input data for land product such as Normalized Difference Vegetation Index (NDVI), Land Surface Albedo (LSA) and etc. In this study, we Second Simulation of a Satellite Signal in the Solar Spectrum Vector (6SV) Radiative Transfer Model (RTM) for atmospheric correction and estimating surface reflectance from Himawari-8/Advanced Himawari Imager (AHI) reflectance channels. 6SV has the advantage that it has high accuracy by performing the atmospheric correction by dividing the width of the satellite channel by 2.5 nm, but it is slow to use in the operation. So, we use LUT approach to reduce the computation time and avoid the intensive calculation required for retrieving surface reflectance. Estimated surface reflectance data were compared with PROBA-V S1 data to evaluate the accuracy. As a result Root Mean Square Error (RMSE) and bias were about 0.05 and -0.02. It is considered that this error is due to the difference of angle component and Spectral Response Function (SRF) of each channel.

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

    Directory of Open Access Journals (Sweden)

    Sandra Tavares da Silva


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

  14. Store-operated calcium entry is essential for glial calcium signalling in CNS white matter. (United States)

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


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

  15. Plant Calcium Content: Ready to Remodel

    Directory of Open Access Journals (Sweden)

    Mary Lou Guerinot


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

  16. Endoplasmic reticulum calcium stores in dendritic spines. (United States)

    Segal, Menahem; Korkotian, Eduard


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

  17. Application of Calcium Phosphate Materials in Dentistry

    Directory of Open Access Journals (Sweden)

    Jabr S. Al-Sanabani


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

  18. Calcium phosphate: a substitute for aluminum adjuvants? (United States)

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


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

  19. Plant Calcium Content: Ready to Remodel (United States)

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


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

  20. The calcium and vitamin D controversy

    DEFF Research Database (Denmark)

    Abrahamsen, Bo


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

  1. Expert review on coronary calcium

    Directory of Open Access Journals (Sweden)

    Matthew J Budoff


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

  2. [Normal aging and cognition]. (United States)

    Ska, Bernadette; Joanette, Yves


    It is now well documented that normal aging modifies the cognitive functioning and most observations suggest that cognition evolves in the direction of deterioration. The more frequently impaired functions are memory, attention and visual-spatial abilities. On the other hand, some abilities seem to increase, such as vocabulary. Considering the aging effect on cognition, questions remain regarding directionality, universality and reversibility. A great variability in aged related impacts is observed among subjects and among cognitive domains. Some individuals evolved more rapidly than others. Some cognitive functions are more affected by aging than others. General and specific factors are hypothesized to explain the aged related cognitive decline. Among them, educational level, health, cognitive style, life style, personality, are likely to modulate the aged related cognitive evolution by influencing attentional resources and cerebral plasticity. Cognitive resources are essential to develop adaptative strategies. During the life span, resources are activated and increased by learning and training. Considering the role of cognitive resources, successful aging is dependent on several conditions : absence of disease leading to a loss of autonomy, maintenance of cognitive and physical activities, and active and social engaged lifestyle.

  3. Strontium Substitution for Calcium in Lithogenesis (United States)

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


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

  4. A comparison of total calcium, corrected calcium, and ionized calcium concentrations as indicators of calcium homeostasis among hypoalbuminemic dogs requiring intensive care. (United States)

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


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

  5. Tuning local calcium availability: cell-type-specific immobile calcium buffer capacity in hippocampal neurons. (United States)

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


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

  6. Autobiographical Memory in Normal Ageing and Dementia

    Directory of Open Access Journals (Sweden)

    Harvey J. Sagar


    Full Text Available Autobiographical memories in young and elderly normal subjects are drawn mostly from the recent past but elderly subjects relate a second peak of memories from early adulthood. Memory for remote past public events is relatively preserved in dementia, possibly reflecting integrity of semantic relative to episodic memory. We examined recall of specific, consistent autobiographical episodes in Alzheimer's disease (AD in response to cue words. Patients and control subjects drew most memories from the recent 20 years: episode age related to anterograde memory function but not subject age or dementia. Subjects also related a secondary peak of memories from early adulthood; episode age related to subject age and severity of dementia. The results suggest that preferential recall of memories from early adulthood is based on the salience of retrieval cues, altered by age and dementia, superimposed on a temporal gradient of semantic memory. Further, AD shows behavioural similarity to normal ageing.


    Directory of Open Access Journals (Sweden)



    Full Text Available

    Normal" style="margin: 0cm 0cm 0pt; line-height: normal; text-align: justify; mso-layout-grid-align: none;"> The osmotic dehydration kinetics of guavas in maltose solutions at 40 and 60ºBrix, with addition of 0, 0.6 and 1.2% of calcium lactate was studied in this paper and the final product quality was evaluated. The experiments were carried out up to 60 hours and samples were taken for analysis at different times to evaluate guavas weight reduction, water loss and sugar gain and to characterize the product according to its texture and color. After 24 hours of process the mass transfer of water and sugar between the osmotic solution and the fruit was negligible, showing that process equilibrium was reached. The increase of sugar concentration in the osmotic solution showed strong influence on the dehydration process, increasing the water loss and reducing sugar gain. The presence of calcium ions in the osmotic solution also influenced the kinetics of mass transfer and showed a strong influence on fruit texture. Higher values of stress and strain at failure were obtained when calcium lactate was employed. The effect of the different osmotic treatments on the color parameters was also investigated and significant changes were observed in the values of chroma C* and hue H* due to sugar concentration and calcium addition.

    Normal" style="margin: 0cm 0cm 0pt; line-height: normal; text-align: justify; mso-layout-grid-align: none;">

    KEYWORDS: Osmotic dehydration; kinetics; guava; maltose; calcium lactate.

  8. Delayed serum calcium biochemical response to successful parathyroidectomy in primary hyperparathyroidism. (United States)

    Alabdulkarim, Yousof; Nassif, Edgard


    Parathyroidectomy is considered the standard treatment for primary hyperparathyroidism, however, though the onset of biochemical response is variable and is different from one patient to the other. To evaluate the onset of systemic response and the biochemical normalization of serum calcium levels to a successful surgery. In a retrospective fashion, we collected clinical data from 303 patients admitted to our hospital between 2005 and 2008, with a diagnosis of primary hyperparathyroidism after sestamibi localization. The pathology reports, parathyroidectomy results, the preoperative and postoperative parathormone (PTH) and serum calcium levels were reviewed. Response of each patient to the surgery was studied and all the data were analyzed to determine how fast the serum calcium levels drop. The majority of patients (72.9%, 221/303) showed a decrease in their serum calcium levels to normal values within 48 h. While in 40 patients it took 72 hours and 42 patients (13.8%) had a delayed normalization for more than 72 h. The pathology in the PH group was predominantly of a single adenoma 80.9% vs.19.1 with hyperplasia with a P of 0.03. Preoperative parathyroid hormone PTH elevation was not significantly deferent between the two groups (PH and EN) with a mean of 7.9±5.36 vs. 7.41±14.5 pmol/L respectively with a P of 0.43. The majority of patients with primary hyperparathyroidism (PHP) respond to parathyroidectomy in the form of normalization of their serum calcium levels and PTH within 48 h; however, a certain group of patients will need more than 3 days.

  9. Diagnosis and assessment of skeletal related disease using calcium 41 (United States)

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


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

  10. Non-calcium desulphurisation technologies

    Energy Technology Data Exchange (ETDEWEB)

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


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

  11. Calcium-sensitive immunoaffinity chromatography

    DEFF Research Database (Denmark)

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


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

  12. Variations in the lead, zinc, and calcium content of Dendrobaena rubida (Oligachaeta) in a base metal mining area

    Energy Technology Data Exchange (ETDEWEB)

    Ireland, M.P.; Wooton, R.J.


    A study was made of the concentrations of lead, zinc and calcium in Dendrobaena rubida (Savigny) taken at different times of the year and at three different sites. Lead levels in earthworms reflected the levels in the soils and the highest concentrations occurred in the winter months. Zinc appeared to be unrelated to soil levels at the site where the level of zinc in the soil was high. At the sites with lower levels of zinc in the soil the lowest concentration of zinc in earthworms was found in November. Earthworm calcium values were inversely proportional to the soil levels but monthly variations were inconsistent. There was a good correlation in earthworms between lead and calcium at the sites with high levels of lead in the soil. The concentration of metal in D. rubida is discussed in relation to seasonal changes, regulation and lead/calcium antagonism. (auth)

  13. Differences in peripartal plasma parameters related to calcium homeostasis of dairy sheep and goats in comparison with cows. (United States)

    Wilkens, Mirja R; Liesegang, Annette; Richter, Julia; Fraser, David R; Breves, Gerhard; Schröder, Bernd


    Recently it has been demonstrated that there are differences between sheep and goats in respect to adaptation to a calcium-restricted diet. It was the aim of the present study to evaluate whether species-specific peculiarities also occur when calcium homoeostasis is challenged by lactation. Therefore, we investigated the time courses of plasma parameters related to calcium homoeostasis (calcium, phosphate, calcitriol, the bone resorption marker CrossLaps and the bone formation marker osteocalcin) during the transition period in multiparous animals of both species and compared the results to data from a former study carried out with dairy cows. As in cows, plasma calcium and the ratio of bone formation to bone resorption decreased at parturition in goats while plasma calcitriol increased. On day 10 post partum the bone parameters of goats reached prepartum values again, which was not the case in cows. Sheep were found to experience a challenge of calcium homoeostasis already 10 d before parturition, reflected by a very low ratio of bone formation to bone resorption, which was not accompanied by an increase in plasma calcitriol. Additionally, sheep and goats which had been in milk for 3 months were sampled, dried-off and sampled again 6 weeks later. In dried-off animals there were no detectable differences in parameters of bone metabolism. In conclusion we could show that the contribution of bone mobilisation to the compensation for the enhanced calcium demand due to lactation differs between the three ruminant species.

  14. Lunar surface reflectance by LALT aboard KAGUYA (United States)

    Noda, H.; Araki, H.; Ishihara, Y.; Tazawa, S.; Sasaki, S.; Kawano, N.


    The Laser Altimeter (LALT) aboard Japanese lunar explorer KAGUYA (SELENE) is a ranging instrument which measures the distance between the satellite and the lunar surface with accuracy of 1 m by detecting the timing delay of the reflected laser light. The main science goal of the LALT is to obtain the lunar global topographic data including polar regions for the study of the origin and the evolution of the Moon [1]. Besides, the LALT is equipped with an intensity monitor of the returned pulses. The intensity of the returned pulses contains information concerning surface roughness and reflectance of the footprints, which will contribute to the study of the lunar surface maturity and age. The reflectance at LALT wavelength (1064nm) is sensitive to the surface maturity and composition. The data should be particularly important at lunar polar regions where camera instruments should suffer from phase angle effects in the surface reflectance and moreover cannot obtain reflectance data at the permanently shadowed area. The normal operation of the LALT began on 30th, December 2007 after two months’ commissioning phase. Before the end of the normal operation phase in October 2008, the LALT measured more than 10 million range data. Unfortunately, due to the laser power decrease and also possible smaller surface reflectance than the expected value before launch (15 % at 1 micro meter), the return pulse intensity during the nominal mission phase is so small that they are not reliable enough to discuss the surface property. During the extended mission phase, which started November 2008, the satellite altitude decreased to 50 km. Due to the malfunction of the reaction wheel and high-voltage instruments were shutdown, the observation was suspended until 11th of February, 2009. LALT successfully resumed observation on 12th February and continued observation until the controlled crash of KAGUYA onto the Moon on 10th of June, 2009. Thanks to the lower orbit during this phase, the

  15. Normal and pathological altruism. (United States)

    Seelig, B J; Rosof, L S


    The psychoanalytic literature on altruism is sparse, although much has been written on this topic from a sociobiological perspective. Freud (1917) first described the concept in "Libido Theory and Narcissism." In 1946 Anna Freud coined the term "altruistic surrender" to describe the psychodynamics of altruistic behavior in a group of inhibited individuals who were neurotically driven to do good for others. The usefulness and clinical applicability of this formulation, in conjunction with the frequent coexistence of masochism and altruism, encouraged psychoanalysts to regard all forms of altruism as having masochistic underpinnings. Since then, there has been a conflation of the two concepts in much of the analytic literature. This paper reexamines the psychoanalytic understanding of altruism and proposes an expansion of the concept to include a normal form. Five types of altruism are described: protoaltruism, generative altruism, conflicted altruism, pseudoaltruism, and psychotic altruism. Protoaltruism has biological roots and can be observed in animals. In humans, protoaltruism includes maternal and paternal nurturing and protectiveness. Generative altruism is the nonconflictual pleasure in fostering the success and/or welfare of another. Conflicted altruism is generative altruism that is drawn into conflict, but in which the pleasure and satisfaction of another (a proxy) is actually enjoyed. Pseudoaltruism originates in conflict and serves as a defensive cloak for underlying sadomasochism. Psychotic altruism is defined as the sometimes bizarre forms of caretaking behavior and associated self-denial seen in psychotic individuals, and often based on delusion. We consider Anna Freud's altruistic surrender to combine features of both conflict-laden altruism and pseudoaltruism. Two clinical illustrations are discussed.

  16. Global South: Anthropological Reflections

    DEFF Research Database (Denmark)

    Steur, Luisa Johanna; Kalb, Don


    The global south is a complex and dynamic concept that straddles multiple social science and humanist disciplines. Emerging around 2000, it reflects the agenda of two ascending forces in those years: the antiglobalist (alterglobalist/global justice) movement and the World Social Forum, on the one...... hand, and an alliance of Southern states within the World Trade Organization on the other. Generally seen as an inheritor of the emancipatory thought behind the notion of the ‘third world,’ in the social sciences the idea of the ‘global south’ is also entangled with more classical academic themes...

  17. Normal Stress or Adjustment Disorder? (United States)

    ... Lifestyle Stress management What's the difference between normal stress and an adjustment disorder? Answers from Daniel K. Hall-Flavin, M.D. Stress is a normal psychological and physical reaction to ...

  18. On the Folded Normal Distribution

    Directory of Open Access Journals (Sweden)

    Michail Tsagris


    Full Text Available The characteristic function of the folded normal distribution and its moment function are derived. The entropy of the folded normal distribution and the Kullback–Leibler from the normal and half normal distributions are approximated using Taylor series. The accuracy of the results are also assessed using different criteria. The maximum likelihood estimates and confidence intervals for the parameters are obtained using the asymptotic theory and bootstrap method. The coverage of the confidence intervals is also examined.

  19. Escuela Normal (Normal School of Costa Rica: History and Legacy

    Directory of Open Access Journals (Sweden)

    Vivian Carvajal-Jiménez


    Full Text Available On the centennial of the Escuela Normal (Normal School of Costa Rica, this paper discusses its role and its legacy in teacher training.  It is structured in three parts. Firstly, it presents a brief historical background of the origin and profile of normal schools in various parts of the world. Secondly, it describes the development of the Escuela Normal (Normal School in Costa Rica, refers to various personalities and significant elements that have set the course and prestige of the institution, and places the emphasis on its key role in the humanistic training of teachers, which helped to establish the foundations of Costa Rican educational development. Finally, it presents some remarks about the educational legacy of this noble institution that has remained to this day, particularly in tertiary education, in the teacher training career at the National University, the major historical heir of the Escuela Normal (Normal School.

  20. Calcium wave signaling in cancer cells (United States)



    Ca2+ functions as an important signaling messenger right from beginning of the life to final moment of the end of the life. Ca2+ is needed at several steps of the cell cycle such as early G1, at the G1/S, and G2/M transitions. The Ca2+ signals in the form of time-dependent changes in intracellular Ca2+ concentrations, [Ca2+]i, are presented as brief spikes organized into regenerative Ca2+ waves. Ca2+-mediated signaling pathways have also been shown to play important roles in carcinogenesis such as transformation of normal cells to cancerous cells, tumor formation and growth, invasion, angiogenesis and metastasis. Since the global Ca2+ oscillations arise from Ca2+ waves initiated locally, it results in stochastic oscillations because although each cell has many IP3Rs and Ca2+ ions, the law of large numbers does not apply to the initiating event which is restricted to very few IP3Rs due to steep Ca2+ concentration gradients. The specific Ca2+ signaling information is likely to be encoded in a calcium code as the amplitude, duration, frequency, waveform or timing of Ca2+ oscillations and decoded again at a later stage. Since Ca2+ channels or pumps involved in regulating Ca2+ signaling pathways show altered expression in cancer, one can target these Ca2+ channels and pumps as therapeutic options to decrease proliferation of cancer cells and to promote their apoptosis. These studies can provide novel insights into alterations in Ca2+ wave patterns in carcinogenesis and lead to development of newer technologies based on Ca2+ waves for the diagnosis and therapy of cancer. PMID:20875431