Calcium Activity Research Articles

Palopegteriparatide Treatment Improves Renal Function in Adults with Chronic Hypoparathyroidism: 1-Year Results from the Phase3 PaTHway Trial.

Individuals with chronic hypoparathyroidism managed with conventional therapy (active vitaminD and calcium) have an increased risk for renal dysfunction versus age- and sex-matched controls. Treatments that replace the physiologic effects of parathyroid hormone (PTH) while reducing the need for conventional therapy may help prevent a decline in renal function in this population. This post hoc analysis examined the impact of palopegteriparatide treatment on renal function in adults with chronic hypoparathyroidism. PaTHway is a phase3 trial of palopegteriparatide in adults with chronic hypoparathyroidism that included a randomized, double-blind, placebo-controlled 26-week period followed by an ongoing 156-week open-label extension (OLE) period. Changes in renal function over 52weeks (26weeks blinded + 26weeks OLE) were assessed using estimated glomerular filtration rate (eGFR). A subgroup analysis was performed with participants stratified by baseline eGFR < 60 or ≥ 60mL/min/1.73m2. At week52, over 95% (78/82) of participants remained enrolled in the OLE and of those, 86% maintained normocalcemia and 95% achieved independence from conventional therapy (no active vitaminD and ≤ 600mg/day of calcium), with none requiring active vitaminD. Treatment with palopegteriparatide over 52weeks resulted in a mean (SD) increase in eGFR of 9.3 (11.7)mL/min/1.73m2 from baseline (P < 0.0001) and 43% of participants had an increase ≥ 10mL/min/1.73m2. In participants with baseline eGFR < 60mL/min/1.73m2, 52weeks of treatment with palopegteriparatide resulted in a mean (SD) increase of 11.5 (11.3) mL/min/1.73m2 (P < 0.001). One case of nephrolithiasis was reported for a participant in the placebo group during blinded treatment; none were reported through week52 with palopegteriparatide. In this post hoc analysis of the PaTHway trial, palopegteriparatide treatment was associated with significantly improved eGFR at week52 in addition to previously reported maintenance and normalization of serum and urine biochemistries. Further investigation of palopegteriparatide for the preservation of renal function in hypoparathyroidism is warranted. ClinicalTrials.gov NCT04701203.

A Comprehensive Fuzzy Model for Understanding Neuronal Calcium Distribution in Presence of VGCC, Na+/Ca2+ Exchanger, Buffer, and ER Fluxes.

Free Calcium ions in the cytosol are essential for many physiological and physical functions. The free calcium ions are commonly regarded as a second messenger, are an essential part of brain communication. Numerous physiological activities, such as calcium buffering and calcium ion channel flow, etc. influence the cytosolic calcium concentration. In light of the above, the primary goal of this study is to develop a model of calcium distribution in neuron cells when a Voltage-Gated Calcium Channel and Sodium Calcium Exchanger are present. As we know, decreased buffer levels and increased calcium activity in the Voltage-Gated Calcium Channel and Sodium Calcium Exchanger lead to Alzheimer's disease. Due to these changes, the calcium diffusion in that location becomes disrupted and impacted by Alzheimer's disease. The model has been constructed by considering key factors like buffers and ER fluxes when Voltage-Gated Calcium Channels and Sodium Calcium Exchangers are present. Based on the physiological conditions of the parameters, appropriate boundary conditions have been constructed in the fuzzy environment. This model is considered a fuzzy boundary value problem with the source term and initial boundary conditions are modeled by triangular fuzzy functions. In this, paper we observed the approximate solution of the mathematical model which was investigated by the fuzzy undetermined coefficient method. The solution has been performed through MATLAB and numerical results have been computed using simulation. The observation made that the proper operation of the Voltage-Gated Calcium Channel and Sodium Calcium Exchanger is critical for maintaining the delicate equilibrium of calcium ions, which regulates vital cellular activities. Dysregulation of Voltage-Gated Calcium Channel and Sodium Calcium Exchanger activity has been linked to neurodegenerative illnesses like Alzheimer's disease.

STARDUST: a pipeline for the unbiased analysis of astrocyte regional calcium dynamics.

Calcium imaging has become a popular way to probe astrocyte activity, but few analysis methods holistically capture discrete calcium signals that occur across the astrocyte domain. Here, we introduce STARDUST, a pipeline for the Spatio-Temporal Analysis of Regional Dynamics & Unbiased Sorting of Transients from fluorescence recordings of astrocytes, and provide step-by-step guidelines. STARDUST yields fluorescence time-series from data-defined regions of activity and performs systematic signal detection and feature extraction, enabling the in-depth and unbiased study of astrocyte calcium signals.

THE EXPERIENCE OF USING A NEW PHARMACOLOGICALLY ACTIVE COMPOSITION OF NANOSTRUCTURED FLUORAPATITE IN THE TREATMENT OF EARLY MANIFESTATIONS OF INCREASED TOOTH ABRASION

Despite the obvious successes in the field of preventive and conservative dentistry, the prevalence of abrasion of teeth (ITP) continues to grow: during the period 1992-2004, the proportion of diseases of hard tissues of teeth with elimination properties increased from 30.9 ± 1.8% to 38.2 ± 1.3%, i.e. increased by 7.3% [1, 7-10]. Many issues related to the diagnosis and planning of an integrated approach to the provision of dental care to patients with moderate CAH have not yet been sufficiently studied and covered [2]. Biologically active calcium phosphate in gel or colloidal state is currently of increasing interest in many areas of clinical medicine related to the problem of regeneration of soft and hard tissues of the body. It has been established that the biological activity of apatite largely depends on the size of its particles or grains, and the higher the dispersion of the substance, the more pronounced it is [3]. The use of pure compounds, as well as various combinations of bioactive substances to improve properties such as adhesion, bioactivity and biocompatibility, is also very promising [4]. A promising direction of modification of calcium hydroxyapatite (HCA) from the point of view of obtaining materials with improved properties is the introduction of fluorine and silicon atoms into the structure of HCA. This transformation increases the stability of the material in the chemically active environment of the human body (due to the presence of fluoride ions) and increases its biological activity (due to the presence of silicate ions), while maintaining the inherent biocompatibility of HAP [5]. Nanotechnology is used in the study, production and use of nanostructures, devices and systems, including targeted control and modification of the shape, size, interaction and integration of their constituent nanoscale elements (1-100 nm) to obtain objects with new chemical, physical and biological properties. A number of technologies and methods. Direct transport of medicines to the focus of the pathological process can increase the effectiveness of existing drug therapies [6]. A promising direction in modern dentistry is the creation of new pharmacological agents with particle sizes of the order of 10-9 (nanoparticles) for noninvasive treatment and early prevention of dental diseases. The aim of the study was to study the effectiveness of new pharmacologically active compositions of nanostructured fluorohydroxyapatite in the treatment of early symptoms of dental hyperextension.

Effect of novel blanching methods on Infra-red drying characteristics and quality attributes of elephant foot yam

The present study evaluated the effect of various pre-treatments (Potassium metabisulphite (KMS), KMS+Ultrasonication (KMSUS), KMS+Microwave (KMSMW), KMS+Hot water (KMSHWB) followed by infrared drying on the quality of Elephant Foot Yam (EFY). KMSMW-treated samples showed the fastest drying rate and highest moisture diffusivity, whereas the KMS-treated sample had the highest weight gain (171.57 %) in rehydration (80 °C). KMSMW and KMSHWB-treated samples exhibited softer textures in rehydration compared to control. Pre-treated samples had higher water absorption capacity and lower oil absorption capacity compared to the control. Pre-treatments also influenced the amylose content and the highest amylose content was observed for KMSUS (21.25 %). Pre-treatments positively influenced the retention of bioactive compounds and reduced the calcium oxalate (117.37 mg/g to 64.09 mg/g). Among all the pre-treatments, KMSHWB showed higher retention of bioactive compounds viz., TPC (297.67 mg GAE/100 g), TFC (922.22 mg QE/100 g), DPPH scavenging activity (57.91 %), ABTS (1.42 mmol TE/100 g) and lowest calcium oxalate (64.09 mg/100 g).

Therapeutic Effects of Capsaicin on Pain Management

Pain is an undesirable sensory experience that occurs from the noisome stimulus, it becomes a warning sign of an upcoming disease or existing disease thereby signaling immediate attention. There exists a variety of pharmacological and non-pharmacological methods to alleviate pain, with their own effects and impacts on health. The natural herb capsicum, used in most families as a spice is also found to have the therapeutic effects of for treating cardiovascular disorders, respiratory issues, gastrointestinal problems, urological disorders, cancer, diabetic peripheral neuropathy, obesity and pain reduction, especially in osteoarthritis and rheumatoid arthritis. It acts as a counter-irritant for various conditions like rheumatism, lumbago and neuralgia. It reduces pain by aiding in the depletion of substance-P and increases the activation of intracellular calcium by activating the calcium channel. The stimulation of transient receptor potential vanilloid 1 (TRPV1) causes effects like analgaesia, anti-infectious, anti-carcinogenic and antioxidant. It is permissible to use capsaicin in low concentrations such as in creams, lotions, gel patches and nasal sprays. High-concentration capsaicin is available in the form of oral formulations, intradermal, subcutaneous and intravenous. Capsaicin is mostly available in topical form, in many concentrations such as 0.025%, 0.0355%, 0.075% and 0.10%. It has been permitted to use capsaicin to the maximum concentration of 8%. Capsaicin is safe to use even in pregnancy, lactation, children and adolescents but is contraindicated for children less than 2 years old as well as for people with bleeding disorders..

Effect of electroacupuncture stimulation of "Sibai"(ST2) and "Quanliao"(SI18) on excitatory neurons of sensorimotor cortex in mice.

To observe the activation state and neuronal types of somatosensory cortex and the primary motor cortex induced by electroacupuncture (EA) stimulation of "Sibai" (ST2) and "Quanliao" (SI18) acupoints in mice. Male C57BL/6J mice were randomly divided into blank control and EA groups, with 6 mice in each group. Rats of the EA group received EA stimulation (2 Hz, 0.6 mA) at ST2 and SI18 for 30 minutes. Samples were collected after EA intervention, and immunofluorescence staining was performed to quantify the expression of the c-Fos gene (proportion of c-Fos positive cells) in the somatosensory cortex and primary motor cortex. The co-labelled cells of calcium/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) and gamma-aminobutyric acid (GABA) in the somatosensory cortex and primary motor cortex were observed and counted by using microscope after immunofluorescence staining. Another 10 mice were used to detect the calcium activity of excitatory neurons in the somatosensory cortex and primary motor cortex by fiber photometry. In comparison with the blank control group, the number of c-Fos positive cells, and the proportion of c-Fos and CaMKⅡ co-labelled cells in both the somatosensory cortex and primary motor cortex were significantly increased after EA stimulation (P<0.05). No significant changes were found in the proportion of c-Fos and GABA co-labeled cells in both the somatosensory cortex and primary motor cortex after EA. Results of fiber optic calcium imaging technology showed that the spontaneous calcium activity of excitatory neurons in both somatosensory cortex and primary motor cortex were obviously increased during EA compared with that before EA (P<0.01), and strikingly reduced after cessation of EA compared with that during EA (P<0.05). Under physiological conditions, EA of ST2 and SI18 can effectively activate excitatory neurons in the somatosensory cortex and primary motor cortex.

Appraisal of Minerals, Fasting Blood Glucose, and Lipid Parameters in Obese and Nonobese Premenopausal Women.

Introduction Menopause is an important milestone in the lives of women. Despite it being a natural phenomenon, menopause brings a lot of changes in a woman'slife, which significantly affects their health and well-being.Menopause involves the cessation of hormone productionnecessary for menstrual cycles and fertility of females. The absence of these hormones may disturb the homeostasis of minerals, blood glucose, and lipid parameters and predispose women to several health conditions affecting different organs. Obesity has been identified as one of the several conditions that influence the health of women. Therefore, assessing women'shealth before menopause may improveunderstanding of their well-being and predict problems during and after menopause. The present study evaluated the activities of calcium, magnesium, phosphorous, fasting blood glucose (FBG), and lipid parameters in obese and nonobese premenopausal women. Methods The present study included 90 obese and 110 nonobese premenopausal women attending the General Medicine and Obstetrics and Gynaecology Departments of Gandhi Medical College and Hospital (GMC&H), Secunderabad, Telangana, India. The body mass index (BMI) was measured in all the study participants to put them under obese and nonobese categories. Blood samples were collected from all the study participants for the estimation of the activities of minerals like calcium, magnesium, phosphorous,FBG, and lipid parameters including total cholesterol (TC), triglycerides (TG), very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Results The results demonstrated a significant difference in the activities of lipid parameters (TC-obese (158.90 ± 20.20 mg/dl) versus nonobese (148.7 ± 18.6 mg/dl), p < 0.05; TG-obese (143.1 ± 58.2 mg/dl) versus nonobese (118.40 ± 55.80 mg/dl), p < 0.01; VLDL-obese (28.30 ± 11.50 mg/dl) versus nonobese (23.30 ± 11 mg/dl), p < 0.05; LDL-obese (92 ± 30.30 mg/dl) versus nonobese (73.90 ± 26.10 mg/dl), p < 0.01; HDL-obese (61.60 ± 12.50) versus nonobese (65.30 ± 11.25 mg/dl), p < 0.01), FBG (obese (106.80 ± 32.20 mg/dl) versus nonobese (88.50 ± 42.60 mg/dl); p < 0.01)), and magnesium (obese (1.79 ± 0.36 mg/dl) versus nonobese (2.42 ± 0.67 mg/dl); p < 0.01)). However, the activities of calcium (obese (9 ± 0.54 mg/dl) vs. nonobese (8.9 ± 0.58); p > 0.05)) and phosphorous (obese (3.84 ± 0.53 mg/dl) versus nonobese (3.75 ± 0.46 mg/dl); p > 0.05)) was found to be similar in obese and nonobese premenopausal women. Conclusions The results suggest that obese premenopausal women revealed lowered activities of magnesium that can predispose them to chronic diseases like cardiovascular diseases. In addition, obese women showed higher activities of FBG that predisposes them to type 2 diabetes mellitus (T2DM). There was significant variation in the lipid parameters among obese and nonobese women. However, serum calcium and phosphorous were similar in obese and nonobese premenopausal women.

Construction of human 3D striato-nigral assembloids to recapitulate medium spiny neuronal projection defects in Huntington’s disease

The striato-nigral (Str-SN) circuit is composed of medium spiny neuronal projections that are mainly sent from the striatum to the midbrain substantial nigra (SN), which is essential for regulating motor behaviors. Dysfunction of the Str-SN circuitry may cause a series of motor disabilities that are associated with neurodegenerative disorders, such as Huntington's disease (HD). Although the etiology of HD is known as abnormally expanded CAG repeats of the huntingtin gene, treatment of HD remains tremendously challenging. One possible reason is the lack of effective HD model that resembles Str-SN circuitry deficits for pharmacological studies. Here, we first differentiated striatum-like organoids from human pluripotent stem cells (hPSCs), containing functional medium spiny neurons (MSNs). We then generated 3D Str-SN assembloids by assembling striatum-like organoids with midbrain SN-like organoids. With AAV-hSYN-GFP-mediated viral tracing, extensive MSN projections from the striatum to the SN are established, which formed synaptic connection with GABAergic neurons in SN organoids and showed the optically evoked inhibitory postsynaptic currents and electronic field potentials by labeling the striatum-like organoids with optogenetic virus. Furthermore, these Str-SN assembloids exhibited enhanced calcium activity compared to that of individual striatal organoids. Importantly, we further demonstrated the reciprocal projection defects in HD iPSC-derived assembloids, which could be ameliorated by treatment of brain-derived neurotrophic factor. Taken together, these findings suggest that Str-SN assembloids could be used for identifying MSN projection defects and could be applied as potential drug test platforms for HD.

Is There a Need for an Exogenous Activator Along with PRP for Early Knee Osteoarthritis? A Triple-Blinded Randomized Control Trial.

In addition to other variables associated with PRP injections for Knee Osteoarthritis (OA), some confusion exists about the role of exogenous activators. The current study looks at matched groups getting PRP injections with or without activator (Calcium gluconate) in early knee OA patients. Patients of early OA knee meeting inclusion criteria were randomly divided into 2 groups; Group A (43 patients) received 8ml PRP injection alone, and Group B (48 patients) received 8ml PRP along with 2ml Calcium gluconate as activator. The patients were evaluated at baseline, 6weeks, 3months and 6months for WOMAC Pain and Total WOMAC scores; secondary variables assessed were VAS score and patient satisfaction. The baseline characteristics of both groups were comparable. Leucocyte-depleted PRP with 5 times concentration and average absolute platelet numbers of 7.144 billion per knee was injected. Mean Pain WOMAC scores decreased in both groups from baseline (group A-8.68, group B-9.09) to final follow-up (group A-4.67, group B-5.11). Similarly, Mean Total WOMAC scores decreased from baseline (group A-37.81, group B-37.41) to (group A-21, group B-21.36) at the final follow-up in both groups. There was no significant difference between both groups, and both showed similar trends. Similar findings were noted for VAS scores. Patient satisfaction was also not different (group A, 90.69%, group B, 89.58%) at the end of 6months. Our study concluded doubtful role of adding exogenous activator to PRP preparation. The online version contains supplementary material available at 10.1007/s43465-024-01159-7.

Cellular resolution contributions to ictal population signals.

The increased amplitude of ictal activity is a common feature of epileptic seizures, but the determinants of this amplitude have not been identified. Clinically, ictal amplitudes are measured electrographically (using, e.g., electroencephalography, electrocorticography, and depth electrodes), but these methods do not enable the assessment of the activity of individual neurons. Population signal may increase from three potential sources: (1) increased synchrony (i.e., more coactive neurons); (2) altered active state, from bursts of action potentials and/or paroxysmal depolarizing shifts in membrane potential; and (3) altered subthreshold state, which includes all lower levels of activity. Here, we quantify the fraction of ictal signal from each source. To identify the cellular determinants of the ictal signal, we measured single cell and population electrical activity and neuronal calcium levels via optical imaging of the genetically encoded calcium indicator (GECI) GCaMP. Spontaneous seizure activity was assessed with microendoscopy in an APP/PS1 mouse with focal cortical injury and via widefield imaging in the organotypic hippocampal slice cultures (OHSCs) model of posttraumatic epilepsy. Single cell calcium signals were linked to a range of electrical activities by performing simultaneous GECI-based calcium imaging and whole-cell patch-clamp recordings in spontaneously seizing OHSCs. Neuronal resolution calcium imaging of spontaneous seizures was then used to quantify the cellular contributions to population-level ictal signal. The seizure onset signal was primarily driven by increased subthreshold activity, consistent with either barrages of excitatory postsynaptic potentials or sustained membrane depolarization. Unsurprisingly, more neurons entered the active state as seizure activity progressed. However, the increasing fraction of active cells was primarily driven by synchronous reactivation and not from continued recruitment of new populations of neurons into the seizure. This work provides a critical link between single neuron activity and population measures of seizure activity.

Cerebellar Heterogeneity and Selective vulnerability in Spinocerebellar Ataxia Type 1 (SCA1)

Heterogeneity is one of the key features of the healthy brain and selective vulnerability characterizes many, if not all, neurodegenerative diseases. While cerebellum contains majority of brain cells, neither its heterogeneity nor selective vulnerability in disease are well understood. Here we describe molecular, cellular and functional heterogeneity in the context of healthy cerebellum as well as in cerebellar disease Spinocerebellar Ataxia Type 1 (SCA1). We first compared disease pathology in cerebellar vermis and hemispheres across anterior to posterior axis in a knock-in SCA1 mouse model. Using immunohistochemistry, we demonstrated earlier and more severe pathology of PCs and glia in the posterior cerebellar vermis of SCA1 mice. We also demonstrate heterogeneity of Bergmann glia in the unaffected, wild-type mice. Then, using RNA sequencing, we found both shared, as well as, posterior cerebellum-specific molecular mechanisms of pathogenesis that include exacerbated gene dysregulation, increased number of altered signaling pathways, and decreased pathway activity scores in the posterior cerebellum of SCA1 mice. We demonstrated unexpectedly large differences in the gene expression between posterior and anterior cerebellar vermis of wild-type mice, indicative of robust intraregional heterogeneity of gene expression in the healthy cerebellum. Additionally, we found that SCA1 disease profoundly reduces intracerebellar heterogeneity of gene expression. Further, using fiber photometry, we found that population level PC calcium activity was altered in the posterior lobules in SCA1 mice during walking. We also identified regional differences in the population level activity of Purkinje cells (PCs) in unrestrained wild-type mice that were diminished in SCA1 mice.

The Role of Astrocytes in Migraine with Cortical Spreading Depression: Protagonists or Bystanders? A Narrative Review.

Cortical spreading depression (CSD) is a slow wave of cortical depolarization closely associated with migraines with an aura. Previously, it was thought that CSD depolarization was mainly driven by neurons, with characteristic changes in neuronal swelling and increased extracellular potassium (K+) and glutamate. However, the role of astrocytes, a member of the neurovascular unit, in migraine with CSD has recently received increasing attention. In the early stages of CSD, astrocytes provide neurons with energy support and clear K+ and glutamate from synaptic gaps. However, in the late stages of CSD, astrocytes release large amounts of lactic acid to exacerbate hypoxia when the energy demand exceeds the astrocytes' compensatory capacity. Astrocyte endfoot swelling is a characteristic of CSD, and neurons are not similarly altered. It is primarily due to K+ influx and abnormally active calcium (Ca2+) signaling. Aquaporin 4 (AQP-4) only mediates K+ influx and has little role as an aquaporin. Astrocytes endfoot swelling causes perivascular space closure, slowing the glymphatic system flow and exacerbating neuroinflammation, leading to persistent CSD. Astrocytes are double-edged swords in migraine with CSD and may be potential targets for CSD interventions.

Formation of the calpain-1/calpastatin complex promotes activation of calpain-1 under oxidizing conditions.

Calpains are cysteine proteinases responsible for many biological roles in muscle, including protein degradation, muscle growth, and myoblast fusion. Calpains are inhibited by calpastatin, an endogenous inhibitor. Other factors, such as variations in pH, ionic strength, and oxidation influence calpain activity. This study aimed to determine the extent to which oxidation influences calpastatin inhibition of calpain-1. A series of order of addition assays were used to determine calpain-1 calcium activation and autolysis after exposure to an oxidizing agent (n-ethylmaleimide [NEM] or hydrogen peroxide [H2O2]. In the first series, purified calpastatin was added to the assay before or after oxidizing exposure at 165mM NaCl, pH 6.5. In the second series, incubation buffer ionic strength (165mM or 295mM NaCl) was evaluated. The inhibitory activities of purified porcine calpastatin, purified human calpastatin domain I, or a subdomain B inhibitor peptide were evaluated in the third series. In the fourth series, a maleimide-polyethylene glycol molecule (MAL-PEG; MW = 5,000 Dalton) was used to evaluate the accessibility of free sulfhydryl groups and tagging of calpain-1 under each condition through a molecular weight shift assay. Results from this study indicate that autolysis of calpain-1, when used as an indicator of activation, occurred when the calpain-1/calpastatin complex was exposed to an oxidant or cysteine modifier such as NEM. However, when calpain-1 was exposed to the cysteine modifier before calpastatin, autolysis of calpain-1 did not occur or was significantly decreased (P < 0.05). Irreversible modification of cysteine residues by NEM prevented activation of calpain-1 in the absence of calpastatin, but if the cysteine modification is potentially reversible (H2O2), calpain-1 activity can be recovered. Results from this study indicate that when calpastatin is bound to calpain-1, calpain-1 activation can occur even after being exposed to a cysteine modifier (NEM) or hydrogen peroxide (H2O2). Calpain-1 is not tagged with maleimide-polyethylene glycol (MAL-PEG) in the presence of calpastatin, indicating that calpastatin blocks or covers free cysteines on calpain-1 from modification. Moreover, exposure to calpain-1/calpastatin complex with a cysteine modifier allows activation of calpain-1, indicating that the inhibitory action of calpastatin is compromised. These results indicate a regulatory role for calpastatin that is not inhibitory but protective for calpain-1.

Intraplatelet Calcium Signaling Regulates Thrombus Growth under Flow: Insights from a Multiscale Model

In injured arteries, platelets adhere to the subendothelium and initiate the coagulation process. They recruit other platelets and form a plug that stops blood leakage. The formation of the platelet plug depends on platelet activation, a process that is regulated by intracellular calcium signaling. Using an improved version of a previous multiscale model, we study the effects of changes in calcium signaling on thrombus growth. This model utilizes the immersed boundary method to capture the interplay between platelets and the flow. Each platelet can attach to other platelets, become activated, express proteins on its surface, detach, and/or become non-adhesive. Platelet activation is captured through a specific calcium signaling model that is solved at the intracellular level, which considers calcium activation by agonists and contacts. Simulations reveal a contact-dependent activation threshold necessary for the formation of the thrombus core. Next, we evaluate the effect of knocking out the P2Y and PAR receptor families. Further, we show that blocking P2Y receptors reduces platelet numbers in the shell while slightly increasing the core size. An analysis of the contribution of P2Y and PAR activation to intraplatelet calcium signaling reveals that each of the ADP and thrombin agonists promotes the activation of platelets in different regions of the thrombus. Finally, the model predicts that the heterogeneity in platelet size reduces the overall number of platelets recruited by the thrombus. The presented framework can be readily used to study the effect of antiplatelet therapy under different physiological and pathological blood flow, platelet count, and activation conditions.

TWISP: a transgenic worm for interrogating signal propagation in Caenorhabditis elegans.

Genetically encoded optical indicators and actuators of neural activity allow for all-optical investigations of signaling in the nervous system. But commonly used indicators, actuators, and expression strategies are poorly suited for systematic measurements of signal propagation at brain scale and cellular resolution. Large-scale measurements of the brain require indicators and actuators with compatible excitation spectra to avoid optical crosstalk. They must be highly expressed in every neuron but at the same time avoid lethality and permit the animal to reach adulthood. Their expression must also be compatible with additional fluorescent labels to locate and identify neurons, such as those in the NeuroPAL cell identification system. We present TWISP, a transgenic worm for interrogating signal propagation, that addresses these needs and enables optical measurements of evoked calcium activity at brain scale and cellular resolution in the nervous system of the nematode Caenorhabditis elegans. In every neuron we express a nonconventional optical actuator, the gustatory receptor homolog GUR-3 + PRDX-2, under the control of a drug-inducible system QF + hGR, and a calcium indicator GCAMP6s, in a background with additional fluorophores from the NeuroPAL cell ID system. We show that this combination, but not others tested, avoids optical crosstalk, creates strong expression in the adult, and generates stable transgenic lines for systematic measurements of signal propagation in the worm brain.

Effect of Swimming Free 50 Meters for Males on Calcium Levels and Some Enzymes of Thyroid and Parathyroid Gland

Study purpose. This study aimed to investigate the effect of swimming free 50 meters on calcium levels and activities of some key enzymes involved in calcium metabolism in males. Materials and Methods. Eleven healthy male adults were selected to participate in the study. They freely swam 50 meters daily for four weeks. A one-group pretest-posttest design was used to evaluate the effect of the swimming intervention on markers of calcium metabolism. Measurements were taken for participants before and after swimming. Fasting blood samples were collected before and after swimming to measure serum calcium levels as well as the activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), 5'-nucleotidase, thyroid stimulating hormone (TSH) and parathormone (PTH) by standard enzymatic methods. Results. After four weeks of swimming free 50 meters daily, serum calcium levels showed a statistically significant increase compared to baseline (p &lt; 0.05). The activities of ALP, AST, and ALT were significantly higher post-intervention (p &lt; 0.05 for all enzymes). There were no significant changes in 5'-nucleotidase, TSH, and PTH activities. Conclusions. The results indicate that swimming free 50 meters daily for four weeks increases serum calcium levels, likely through enhanced bone resorption as suggested by the elevated activities of ALP, AST, and ALT. However, there were no significant effects on thyroid and parathyroid functions as assessed by TSH and PTH.

Binding of coagulation factor IXa to procoagulant platelets revisited: Low affinity and interactions with other factors

Binding of activated factor IX (fIXa) to the phosphatidylserine-expressing procoagulant platelets is a critical step in blood coagulation, which is necessary for the membrane-dependent intrinsic tenase complex assembly and factor X activation. However, the nature and parameters of the fIXa binding sites on the procoagulant platelet surface remain unclear. We used flow cytometry to elucidate the quantitative details of the fluorescently labeled fIXa binding to gel-filtered activated platelets. FIXa bound to the procoagulant platelet subpopulation only, with the parameters (maximal number of binding sites at 58900 ± 3400, Kd at 1000 ± 170 nM) similar to binding observed with phospholipid vesicles. No specific high-affinity binding sites for fIXa were detected, and binding proceeded similarly for different methods of procoagulant platelet production (thrombin, thrombin receptor activation peptide, collagen-related peptide, their combinations, or calcium ionophore A23187). Factor VIII, known to form a high affinity complex with fIXa, enhanced fIXa binding to platelets. In contrast, only competition effects were observed for factor X, which binds fIXa with much lower affinity. Unexpectedly, fIXa itself, fIX, and prothrombin also dose-dependently enhance fIXa binding at concentrations below 1000 nM, suggesting the formation of membrane-bound fIXa dimers and fIXa-prothrombin complexes on platelets. These findings provide a novel perspective on the fIXa binding site on procoagulant platelets, which does not have any major differences from pure phospholipid-based model membranes, exhibits inherently low affinity (3–5 orders of magnitude below the physiologically relevant fIXa concentration) but is significantly enhanced by its cofactor VIII, and regulated by previously unknown membrane interactions.

Preparation and characterization of high-ash coal slime-based soil amendment as well as investigations of its adsorption performance and mechanisms towards heavy metals in soil

In this study, high-ash coal slime-based mineral soil amendment (MSA) was prepared via the hydrothermal method using high-ash coal slime as raw material, supplemented with activator calcium oxide and additive KOH solution. After hydrothermal treatment at 230 °C for 5 h, the original crystalline phase (quartz and kaolinite) of the high-ash slime was completely transformed into hydrotalcite zeolite, tobermorite, and silicate of potassium aluminosilicate, which has the largest specific surface area. The adsorption of Pb2+ and Cd2+ was adherent to the kinetic equation of secondary adsorption and Freundlich models, and the removal of Pb2+ and Cd2+ reached up to 362.58 mg g−1 and 64.67 mg g−1. The successive releases of SiO2 and CaO from MSA conformed to the Elovich equation, whereas the releases of SiO2 in Cd-containing environments and CaO in Pb- and Cd-containing environments more closely conformed to the power function; the releases of K2O all conformed to the first-order kinetic equation. The presence of Pb2+ and Cd2+ in the environment promotes the release of potassium and calcium elements with MSA's ion-exchange ability, and attenuates the release of silicon elements. Combining Pb2+ and Cd2+ with silicon resulted in the intolerant precipitation of 3PbO·2SiO2 and Cd2SiO4. The mineral precipitation mechanism is the most important mechanism of MSA in immobilizing heavy metals, accounting for 72.7%–80.5% of the total adsorption. Further contaminated soil immobilization experiments also showed that the application of MSA significantly reduced the bioavailability of soil heavy metals. When the MSA addition amount was 1.6%, the residual state increased by 63.58%. In conclusion, preparing MSA may effectively utilize coal-based solid waste with high added value.

A distinct, high-affinity, alkaline phosphatase facilitates occupation of P-depleted environments by marine picocyanobacteria

Marine picocyanobacteria of the genera Prochlorococcus and Synechococcus, the two most abundant phototrophs on Earth, thrive in oligotrophic oceanic regions. While it is well known that specific lineages are exquisitely adapted to prevailing in situ light and temperature regimes, much less is known of the molecular machinery required to facilitate occupancy of these low-nutrient environments. Here, we describe a hitherto unknown alkaline phosphatase, Psip1, that has a substantially higher affinity for phosphomonoesters than other well-known phosphatases like PhoA, PhoX, or PhoD and is restricted to clade III Synechococcus and a subset of high light I-adapted Prochlorococcus strains, suggesting niche specificity. We demonstrate that Psip1 has undergone convergent evolution with PhoX, requiring both iron and calcium for activity and likely possessing identical key residues around the active site, despite generally very low sequence homology. Interrogation of metagenomes and transcriptomes from TARA oceans and an Atlantic Meridional transect shows that psip1 is abundant and highly expressed in picocyanobacterial populations from the Mediterranean Sea and north Atlantic gyre, regions well recognized to be phosphorus (P)-deplete. Together, this identifies psip1 as an important oligotrophy-specific gene for P recycling in these organisms. Furthermore, psip1 is not restricted to picocyanobacteria and is abundant and highly transcribed in some α-proteobacteria and eukaryotic algae, suggesting that such a high-affinity phosphatase is important across the microbial taxonomic world to occupy low-P environments.