36 research outputs found
P2X receptors: epithelial ion channels and regulators of salt and water transport.
When the results from electrophysiological studies of renal epithelial cells are combined with data from in vivo tubule microperfusion experiments and immunohistochemical surveys of the nephron, the accumulated evidence suggests that ATP-gated ion channels, P2X receptors, play a specialized role in the regulation of ion and water movement across the renal tubule and are integral to electrolyte and fluid homeostasis. In this short review, we discuss the concept of P2X receptors as regulators of salt and water salvage pathways, as well as acknowledging their accepted role as ATP-gated ion channels
The β3-Adrenergic Receptor Agonist Mirabegron Improves Glucose Homeostasis in Obese Humans
BACKGROUND. Beige adipose tissue is associated with improved glucose homeostasis in mice. Adipose tissue contains β3-adrenergic receptors (β3-ARs), and this study was intended to determine whether the treatment of obese, insulin-resistant humans with the β3-AR agonist mirabegron, which stimulates beige adipose formation in subcutaneous white adipose tissue (SC WAT), would induce other beneficial changes in fat and muscle and improve metabolic homeostasis.
METHODS. Before and after β3-AR agonist treatment, oral glucose tolerance tests and euglycemic clamps were performed, and histochemical analysis and gene expression profiling were performed on fat and muscle biopsies. PET-CT scans quantified brown adipose tissue volume and activity, and we conducted in vitro studies with primary cultures of differentiated human adipocytes and muscle.
RESULTS. The clinical effects of mirabegron treatment included improved oral glucose tolerance (P \u3c 0.01), reduced hemoglobin A1c levels (P = 0.01), and improved insulin sensitivity (P = 0.03) and β cell function (P = 0.01). In SC WAT, mirabegron treatment stimulated lipolysis, reduced fibrotic gene expression, and increased alternatively activated macrophages. Subjects with the most SC WAT beiging showed the greatest improvement in β cell function. In skeletal muscle, mirabegron reduced triglycerides, increased the expression of PPARγ coactivator 1 α (PGC1A) (P \u3c 0.05), and increased type I fibers (P \u3c 0.01). Conditioned media from adipocytes treated with mirabegron stimulated muscle fiber PGC1A expression in vitro (P \u3c 0.001).
CONCLUSION. Mirabegron treatment substantially improved multiple measures of glucose homeostasis in obese, insulin-resistant humans. Since β cells and skeletal muscle do not express β3-ARs, these data suggest that the beiging of SC WAT by mirabegron reduces adipose tissue dysfunction, which enhances muscle oxidative capacity and improves β cell function.
TRIAL REGISTRATION. Clinicaltrials.gov NCT02919176.
FUNDING. NIH: DK112282, P30GM127211, DK 71349, and Clinical and Translational science Awards (CTSA) grant UL1TR001998
Australasian malignant pleural effusion (AMPLE)-4 trial: Study protocol for a multi-centre randomised trial of topical antibiotics prophylaxis for infections of indwelling pleural catheters
Background: Malignant pleural effusion (MPE) is a debilitating condition as it commonly causes disabling breathlessness and impairs quality of life (QoL). Indwelling pleural catheter (IPC) offers an effective alternative for the management of MPE. However, IPC-related infections remain a significant concern and there are currently no long-term strategies for their prevention. The Australasian Malignant PLeural Effusion (AMPLE)-4 trial is a multicentre randomised trial that evaluates the use of topical mupirocin prophylaxis (vs no mupirocin) to reduce catheter-related infections in patients with MPE treated with an IPC. Methods: A pragmatic, multi-centre, open-labelled, randomised trial. Eligible patients with MPE and an IPC will be randomised 1:1 to either regular topical mupirocin prophylaxis or no mupirocin (standard care). For the interventional arm, topical mupirocin will be applied around the IPC exit-site after each drainage, at least twice weekly. Weekly follow-up via phone calls or in person will be conducted for up to 6 months. The primary outcome is the percentage of patients who develop an IPC-related (pleural, skin, or tract) infection between the time of catheter insertion and end of follow-up period. Secondary outcomes include analyses of infection (types and episodes), hospitalisation days, health economics, adverse events, and survival. Subject to interim analyses, the trial will recruit up to 418 participants. Discussion: Results from this trial will determine the efficacy of mupirocin prophylaxis in patients who require IPC for MPE. It will provide data on infection rates, microbiology, and potentially infection pathways associated with IPC-related infections. Ethics and dissemination: Sir Charles Gairdner and Osborne Park Health Care Group Human Research Ethics Committee has approved the study (RGS0000005920). Results will be published in peer-reviewed journals and presented at scientific conferences. Trial registration: Australia New Zealand Clinical Trial Registry ACTRN12623000253606. Registered on 9 March 2023
Pharmacological Properties and Physiological Function of a P2X-Like Current in Single Proximal Tubule Cells Isolated from Frog Kidney
Although previous studies have provided evidence for the expression of P2X receptors in renal proximal tubule, only one cell line study has provided functional evidence. The current study investigated the pharmacological properties and physiological role of native P2X-like currents in single frog proximal tubule cells using the whole-cell patch-clamp technique. Extracellular ATP activated a cation conductance (P2Xf) that was also Ca2+-permeable. The agonist sequence for activation was ATP = αβ-MeATP > BzATP = 2-MeSATP, and P2Xf was inhibited by suramin, PPADS and TNP-ATP. Activation of P2Xf attenuated the rundown of a quinidine-sensitive K+ conductance, suggesting that P2Xf plays a role in K+ channel regulation. In addition, ATP/ADP apyrase and inhibitors of P2Xf inhibited regulatory volume decrease (RVD). These data are consistent with the presence of a P2X receptor that plays a role in the regulation of cell volume and K+ channels in frog renal proximal tubule cells
Yield and Bio-Chemical Parameters of Onion (Allium Cepa L.) and Consequences of Saline Irrigation Water on It
At Department of Agricultural Chemistry and Soil Science a pot experiment was conducted during the rabi, season of 2017-18. Department of Agricultural Chemistry and Soil Science situated at College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat. The objective of the study is to assess the consequences of saline irrigation water on yield of Onion (Allium Cepa L.) varieties. The study also possess the growth and nutrients composition of Onion (Allium Cepa L.) varieties and effect of saline irrigation water on it. Four levels of salinity are contained viz., < 2.0, 4.0, 6.0 and 8.0 dS m-1. GJWO-3, GJRO-11, Talaj red, Pilli patti and PWF-131 these five varieties comprised in factorial completely randomized design with three replications. It found that the yield of chlorophyll a (5.77 mg/gf.wt), chlorophyll-b (4.22 mg/gf.wt), and total chlorophyll were significantly influenced by different levels of salinity, whereas; yield of fresh straw (37.03 g/pot), bulb (37.49 g/pot), RWC, proline (0.96 µmole/gf.wt), were significantly influenced among different varieties of onion tested
Adult age differences in decision making across domains: Increased discounting of social and health-related rewards.
Although research on aging and decision making continues to grow, the majority of studies examine decisions made to maximize monetary earnings or points. It is not clear whether these results generalize to other types of rewards. To investigate this, we examined adult age differences in ninety-two healthy participants aged 22–83. Participants completed nine hypothetical discounting tasks, which included three types of discounting factors (time, probability, effort) across three reward domains (monetary, social, health). Participants made choices between a smaller magnitude reward with a shorter time delay / higher probability / lower level of physical effort required and a larger magnitude reward with a longer time delay / lower probability / higher level of physical effort required. Older compared to younger individuals were more likely to choose options that involved shorter time delays or higher probabilities of experiencing an interaction with a close social partner or receiving health benefits from a hypothetical drug. These findings suggest that older adults may be more motivated than young adults to obtain social and health rewards immediately and with certainty
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Adult Age Differences in Decision Making Across Domains: Increased Discounting of Social and Health-Related Rewards
Although research on aging and decision making continues to grow, the majority of studies examine decisions made to maximize monetary earnings or points. It is not clear whether these results generalize to other types of rewards. To investigate this, we examined adult age differences in 92 healthy participants aged 22 to 83. Participants completed 9 hypothetical discounting tasks, which included 3 types of discounting factors (time, probability, effort) across 3 reward domains (monetary, social, health). Participants made choices between a smaller magnitude reward with a shorter time delay/higher probability/lower level of physical effort required and a larger magnitude reward with a longer time delay/lower probability/higher level of physical effort required. Older compared with younger individuals were more likely to choose options that involved shorter time delays or higher probabilities of experiencing an interaction with a close social partner or receiving health benefits from a hypothetical drug. These findings suggest that older adults may be more motivated than young adults to obtain social and health rewards immediately and with certainty. (PsycINFO Database Recor
Influence of climate change on Helicoverpa armigera (Hubner) in pigeonpea
Annual monitoring of the population dynamics of Helicoverpa armigera in unprotected pigeonpea crop during kharif seasons of 2011 to 2014 for 4 years at the farmers field North Gujarat, India. Temperature, rainfall and host-plant species were analyzed with respect to population fluctuation of the insect pest. The observations revealed that, the average number of larval population per plant in the season (from 27th to 3rd standard weeks) was 0.97, 0.32, 0.30 and 0.38 larvae/plant during 2011, 2012, 2013 and 2014 respectively. Population of Helicoverpa armigera had significant and negative correlation with maximum temperature (r= -0.524), rainfall (r= 0.079) and relative humidity (r= -0.827, r= -0.595 morning and evening, respectively)
An enzyme with high catalytic proficiency utilizes distal site substrate binding energy to stabilize the closed state but at the expense of substrate inhibition
Understanding the factors that underpin the enormous catalytic proficiencies of enzymes is fundamental to catalysis and enzyme design. Enzymes are, in part, able to achieve high catalytic proficiencies by utilizing the binding energy derived from nonreacting portions of the substrate. In particular, enzymes with substrates containing a nonreacting phosphodianion group coordinated in a distal site have been suggested to exploit this binding energy primarily to facilitate a conformational change from an open inactive form to a closed active form, rather than to either induce ground state destabilization or stabilize the transition state. However, detailed structural evidence for the model is limited. Here, we use β-phosphoglucomutase (βPGM) to investigate the relationship between binding a phosphodianion group in a distal site, the adoption of a closed enzyme form, and catalytic proficiency. βPGM catalyzes the isomerization of β-glucose 1-phosphate to glucose 6-phosphate via phosphoryl transfer reactions in the proximal site, while coordinating a phosphodianion group of the substrate(s) in a distal site. βPGM has one of the largest catalytic proficiencies measured and undergoes significant domain closure during its catalytic cycle. We find that side chain substitution at the distal site results in decreased substrate binding that destabilizes the closed active form but is not sufficient to preclude the adoption of a fully closed, near-transition state conformation. Furthermore, we reveal that binding of a phosphodianion group in the distal site stimulates domain closure even in the absence of a transferring phosphoryl group in the proximal site, explaining the previously reported β-glucose 1-phosphate inhibition. Finally, our results support a trend whereby enzymes with high catalytic proficiencies involving phosphorylated substrates exhibit a greater requirement to stabilize the closed active form
Table_1_Association of dementia and patient outcomes among COVID-19 patients: A multi-center retrospective case-control study.pdf
BackgroundWe conducted a retrospective cohort study on COVID-19 patients with and without dementia by extracting data from the HCA Healthcare Enterprise Data Warehouse between January-September 2020.AimsTo describe the role of patients' baseline characteristics specifically dementia in determining overall health outcomes in COVID-19 patients.MethodsWe grouped in-patients who had ICD-10 codes for dementia (DM) with age and gender-matched (1:2) patients without dementia (ND). Our primary outcome variables were in-hospital mortality, length of stay, Intensive Care Unit (ICU) admission, ICU-free days, mechanical ventilation (MV) use, MV-free days and 90-day re-admission.ResultsMatching provided similar age and sex in DM and ND groups. BMI (median, 25.8 vs. 27.6) and proportion of patients who had smoked (23.3 vs. 31.3%) were lower in DM than in ND patients. The median (IQR) Elixhauser Comorbidity Index was higher in dementia patients 7 (5–10) vs. 5 (3–7, p ConclusionsOur data showed that COVID-19 patients with dementia did not fare substantially worse, but in fact, fared better when certain metrics were considered.</p