CardIAP: Calcium images analyzer web application

MotivationIonic calcium (Ca2+) plays the role of the second messenger in eukaryotic cells associated with cellular functions of regulation of the cell cycle, such as transport, motility, gene expression, and metabolism (Permyakov and Kretsinger, 2009). The use of fluorometric techniques in isolated cells, loaded with Ca2+ sensitive fluorescent probes allows the quantitative measurement of dynamic events that occur in living, functioning cells. The Cardiomyocytes Images Analyzer Application (CardIAP) covers the need for tools to analyze and retrieve information from confocal microscopy images, in a systematic, accurate, and fast way.ResultsHere we present the CardIAP web app, an automated method for the identification of spatio-temporal patterns in a calcium fluorescence imaging sequence. Through this tool, users can analyze single or multiple Ca2+ transients from confocal line-scan images and obtain quantitative information on the dynamic response of the stimulated myocyte.Our web application also allows the user the extraction of data on calcium dynamics in downloadable tables and plots, simplifying the calculation of the alternation and discordance indices and their classification. CardIAP could assist in studying the underlying mechanisms of anomalous calcium release phenomena.Availability and implementationCardIAP is an open-source app, entirely developed in Python, which can be freely accessed and used at http://cardiap.herokuapp.com/.

A comparative study of serum calcium and magnesium levels in women with pre-eclampsia and normotensive women

Background: Pre-eclampsia is transient but potentially dangerous complication of pregnancy. Despite of pre-eclampsia's prevalence and severity, the pathophysiology of this multisystem disorder is still poorly understood and its aetiology has not yet been fully elucidated. Recently, nutritional deficiency especially micronutrients deficiency is gaining prominence in the pathogenesis of pre-eclampsia. Hypocalcaemia and hypomagnesaemia have been implicated in the pathogenesis of pre-eclampsia. This study has been done to compare serum calcium and magnesium levels in women with pre-eclampsia and normotensive women and their association with severity of pre-eclampsia.Methods: 50 women with pre-eclampsia and 50 normotensive women were included in the study and serum calcium and magnesium levels were measured. Data were analyzed.Results: The serum ionic calcium concentration was significantly lower in the pre-eclamptic cases compared to the normotensive controls (3.34±1.35 versus 4.37±0.74, p=0.0000) similarly serum magnesium concentration was significantly lower in the pre-eclamptic cases compared to the normotensive controls (1.68±0.41 versus 1.94±0.42, p-0.002). Mean serum ionic Ca levels in severe pre-eclampsia group was significantly lower than normotensive pregnant women (p=0.0000) as well as mild pre-eclampsia group (p=0.001). Mean serum Mg in severe pre-eclampsia was significantly lower than normotensive pregnant women (p=0.0008) as well as mild pre-eclampsia group (p=0.03). Serum ionic Ca and Mg had a negative correlation with systolic and diastolic blood pressure.Conclusions: Based on this study, measurements of serum ionic calcium and magnesium among women at risk of for pre-eclampsia may be used to predict the onset and severity of pre-eclampsia.

Endocrinology, Vitamin D and the UK’s Covid-19 Disaster

The formation of cholecalciferol (Vitamin D3) in skin depends on solar UVB to break the B ring of 7-dehydrocholesterol. Its discovery more than a century ago resulted from the identification of rickets as due to deficient sunshine in latitudes far from the equator, exacerbated by the air pollution, factory work and indoor living. Rickets resulted from defective endocrine control of blood calcium, and was accompanied by epidemic tuberculosis from failure of the D3-dependent first-line immune system. The influenza pandemic of 2018 revealed the need for D3 to fight viruses. Half a century later the systemic hormone role of 1,25(OH)D3 of renal origin, under control of PTH, was a major stimulus to understanding the mechanism of action via the VDR-RXR heterodimer. It was soon realised that 1,25(OH)D3 is also produced and acts locally in many organs and tissues provided that there are adequate reserves of the (protein-bound) blood storage form, 25(OH)D. This is the common pool for 1-hydroxylation by any cells that need local activation of VDR for induction of specific genes. In the case of the immune system, the trigger is foreign proteins recognised as ‘non-self’. Local production and action of 1,25(OH)D, and then its local destruction by 24-hydroxylation must all occur below the ‘endocrine radar’, so as not to interfere with systemic calcium control. Coronaviruses through their ‘spike’ protein are internalised by interacting with the ACE-2 receptor, which in turn is down-regulated by Vitamin D. In the process, 25(OH)D is hydroxylated to the active 1,25(OH)D, which must later be degraded to 1,24,25(OH)D. So it is to be expected that when 25(OH)D reserves are low at the onset of infection, they will fall further, allowing virus to enter the cells and trigger a cytokine storm and other damage. Blood PTH will rise to claim any residual 25(OH)D for the dominating systemic role in calcium homeostasis. It follows that intake of vitamin D3 should always be much more than the minimum claimed by the globally-active endocrine system. Unfortunately, the UK’s Specialised Advisory Committee on Nutrition (SACN), does not recognise this. It is dominated by nutritionists, even though food sources of D3 are for most non-existent, and of D2, the vegetable substitute, highly variable. The 400IU of D3 reluctantly recommended for those ‘at risk’, based on endocrinology alone, is grossly inadequate; 4,000IU daily is needed to maintain a blood 25(OH)D at more than 30 ng/ml (75 nmol/l), and provide sufficient reserve for its many autocrine and paracrine functions. The dangers of letting the dominant endocrine function of 1,25(OH)D in ionic calcium control dictate the level of D3 supplements, have once again been underlined by the Covid-19 disaster.

Electrical Propagation of Condensed and Diffuse Ions Along Actin Filaments

In this article, we elucidate the role of divalent ion condensation and high polarization of immobile water molecules in the condensed layer on the propagation of ionic calcium waves along actin filaments. We introduced a novel electrical triple layer model and used a non-linear Debye-Huckel theory with a non-linear, dissipative, electrical transmission line model to characterize the physicochemical properties of each monomer in the filament. This characterization is carried out in terms of an electric circuit model containing monomeric flow resistances and ionic capacitances in both the condensed and diffuse layers. In our studies, we characterized the biocylindrical actin filament model using a high resolution molecular structure. We considered resting and excited states of a neuron using representative mono and divalent electrolyte mixtures. Additionally, we used 0.05V and 0.15V voltage inputs to study ionic waves in voltage clamp experiments on actin filaments. Our results reveal that the physicochemical properties characterizing the condensed and diffuse layers lead to different electrical conduction mediums depending on the ionic species and the neuron state. This region specific propagation mechanism provides a more realistic avenue of delivery by way of cytoskeleton filaments for larger charged cationic species. This new direct path for transporting divalent ions might be crucial for many electrical processes that connect different compartments of the neuron to the soma.

Assessment of the Seric Calcium and Parathormone Levels in Patients Underwent Hemithyroidectomy.

Background and objective: Hypocalcemia is one of the main complications that patients undergoing thyroid surgery can suffer. We believe that there may be an impact on serum parathormone and calcium values, despite only one thyroid cell is manipulated in thyroid lobectomy. The former explanation is the reason because we carried out a measurement and analised a potential correlation between them. Methods: This is a prospective study of 53 patients underwent thyroid lobectomy. The serum parathormone value was determined in the preoperative period, 15 min after extraction of the surgical piece, 24 hours and 3 weeks after surgery. Ionic calcium was also measured at 6 hours, 24 hours and 3 weeks. Postoperative parathormone values were compared as well as their gradient descent respect to the postoperative calcium value. The appearance of the parathyroid glands was described during surgery. Results: In none of the patients did the ionic calcium drop below 4mg / dl. The decrease in preoperative calcemia compared with the values at 6 and 24 hours had statistical significance, there were no differences compared to 3 weeks experiment. An analogous trend was observed between the percentage values of decrease in parathormone and postoperative calcemia. Conclusions: Although the calcemia decreased after a lobectomy, it always remained above 4 mg / dl. We conclude that hemithyroidectomy is a safe technique regarding the appearance of hypocalcemia in the postoperative period.

Specific Adaptive Gene Expression of Smooth Muscle Cells Challenged by Organotelluranes

ABSTRACTOrganotelluranes RT3 and RT4 are thiol reagents that induce mitochondrial transition pore (MTP) opening in a sensitive and insensitive manner to cyclosporin A. Although RT3 and RT4 promote glutathione depletion, paradoxically, they are also an efficient antioxidant for membrane lipids. These compounds' antagonistic effects elicited the challenging question of how the gene expression of antioxidant enzymes would respond to treatment with these compounds. The influence of RT3 and RT4 on antioxidant enzyme expression was investigated in cultured aortic smooth muscle cells (ASMC). RT3 and RT4 promoted disruption of ionic calcium homeostasis, mitochondrial transmembrane potential (ΔΨ), and cell death in a dose-dependent manner. The cell death mechanisms responded qualitatively to the increase of the organotellurane concentration and changed from apoptosis to necrosis. RT3 and RT4 increased the expression of thioredoxin significantly. RT3 also increased the expression of glutaredoxin and glutathione peroxidase, slightly the catalase expression without significant effects on SOD expression. The results are consistent with GSH and protein thiol depletion and discussed based on the cell toxicity mechanism exhibited by these compounds.Abstract Figure

Inter-relation of Hypocalcaemia with Established Osteoporosis and DXA Analysis: A prospective study of 100 Indian subjects.

Purpose: The purpose of the study was to screen the presence of hypocalcemia and clinical signs specific to hypocalcemia in dual-emission X-ray absorptiometry proven osteoporotic patients and also to analyze variations of T scores at specific anatomical regions in lumbar spine and hip. Type: Prospective cohort. Materials and Methods: One hundred patients who had T score of <?2.5 at any of the lumbar levels or in total lumbar T score were selected. Ionic calcium levels (normal – 1.1–1.135 mmol/L) of each patient were calculated. Trousseau’s sign and Chvostek’s sign were checked. Analysis of T scores was done for each patient. Results: Twelve out of 100 patients had hypocalcemia. Out of whom, only one patient had positive Trousseau’s sign and none had Chvostek’s sign present. In normocalcemic patients (n = 88), seven patients had positive Trousseau’s sign and three had Chvostek’s sign present. Average total lumbar T score of 100 patients was ?3.0 (±1.1 SD). After calculating the averages, the L3 had least T score of ?3.3 (±0.9 SD) and L1 had highest T score of ?2.5 (±1.3 SD), respectively. Twenty-seven patients had total hip T scores <?2.5 and 72 patients had T scores <?2.5 at Ward’s triangle. Similarly, average total hip T score of 100 patients was ?2.0 (±1.6 SD); average T score at Ward’s angle was much lower at ?2.9 (±1.4SD). Conclusion: L3 vertebra and Ward’s triangle are most sensitive indicators of osteoporosis. Although theoretically unlikely, hypocalcemia can be present in osteoporotic patients. Trousseau’s sign and Chvostek’s sign may be present in patients with established hypocalcemia; however, their absence does not rule out the diagnosis. Keywords: Osteoporosis, hypocalcemia, T score, ward’s triangle.

Effect of head covering on phototherapy induced hypocalcemia in term neonates with hyperbilirubinemia: A randomised controlled study

BACKGROUND: Phototherapy is the primary treatment for hyperbilirubinemia in neonates. Hypocalcemia is a lesser known but potential detrimental effect of phototherapy. It has been hypothesized that phototherapy inhibits pineal secretion of melatonin, which blocks the effect of cortisol on bone calcium. Therefore, unchecked cortisol increases bone uptake of calcium and induces hypocalcemia. Covering head during phototherapy in order to prevent light reaching to the pineal gland which eventually leads to the prevention of hypocalcemia is hypothesized to prevent hypocalcemia but it lacks sufficient evidence worldwide. METHOD: It is a prospective, randomized controlled study. 112 neonates were randomized into two groups of 56 neonates. Group A underwent phototherapy without head cover and group B with head covered by a cap. RESULT: The mean decline in serum ionic calcium after 48 hours of phototherapy in group A and group B was 0.57±0.37 mg/dl and 0.34±0.24 mg/dl respectively. This decline in serum ionic calcium was significantly higher in group A. (p < 0.001). 26.8% newborns from group A developed hypocalcemia while in group B only 14.3% developed hypocalcemia however it was not found to be statistically significant. Incidence of symptomatic hypocalcemia between the two groups was also not significant. CONCLUSION: There was significant reduction in serum calcium in neonates undergoing phototherapy without head cover as compared to neonates with head cover but risk of hypocalcemia was not significant. Further studies with larger sample size including preterm are recommended.

Calcium and hydroxyapatite binding site of human vitronectin provides insights to abnormal deposit formation

The human blood protein vitronectin (Vn) is a major component of the abnormal deposits associated with age-related macular degeneration, Alzheimer’s disease, and many other age-related disorders. Its accumulation with lipids and hydroxyapatite (HAP) has been demonstrated, but the precise mechanism for deposit formation remains unknown. Using a combination of solution and solid-state NMR experiments, cosedimentation assays, differential scanning fluorimetry (DSF), and binding energy calculations, we demonstrate that Vn is capable of binding both soluble ionic calcium and crystalline HAP, with high affinity and chemical specificity. Calcium ions bind preferentially at an external site, at the top of the hemopexin-like (HX) domain, with a group of four Asp carboxylate groups. The same external site is also implicated in HAP binding. Moreover, Vn acquires thermal stability upon association with either calcium ions or crystalline HAP. The data point to a mechanism whereby Vn plays an active role in orchestrating calcified deposit formation. They provide a platform for understanding the pathogenesis of macular degeneration and other related degenerative disorders, and the normal functions of Vn, especially those related to bone resorption.