Role of 90-kDa Heat Shock Protein (Hsp 90) and Protein Degradation in Regulating Neuronal Levels of G Protein- Coupled Receptor Kinase 3

ABSTRACT Cellular levels of G protein-coupled receptor kinase (GRK)3 determine the sensitivity of the ␣ 2A/B -adrenoceptor (␣ 2 -AR) to agonist-induced down-regulation. Using human neuroblastoma BE(2)-C cells, this study examines how cellular GRK3 levels are affected by several mechanisms reported to influence stability and degradation of other GRKs. We first examined the interaction between the 90-kDa heat shock protein (Hsp90) and GRK3; Hsp90 reportedly affects the maturation and stability of GRK2. In unstimulated cells, GRK3 coimmunoprecipitates with Hsp90, suggesting a physical interaction. Moreover, when GRK3 protein expression was increased by 24-h epinephrine (EPI) treatment, Hsp90 protein expression increased with a similar but slightly delayed time course. To investigate the influence of Hsp90 on GRK3 protein stability, we determined the effect of the Hsp90 inhibitor geldanamycin (GA) on cellular GRK3 levels. GA eliminated the interaction between Hsp90 with GRK3 and produced a rapid, proteasome-mediated, 70% decrease in GRK3 levels within 24 h. To investigate the influence of Hsp90 on up-regulation of GRK3 expression, we examined the effect of GA on EPI-induced up-regulation. GA reduced the absolute increase in GRK3; however, the percentage of increase in GRK3 by EPI was not significantly different in the absence versus presence of GA (141 Ϯ 41 versus 94 Ϯ 12%). Finally, we examined the influence of Ca 2ϩ -activated proteases on cellular GRK3. Treatment with the calcium ionophore ionomycin produced a rapid decrease in GRK3 levels that was inhibited by the calpain inhibitor calpeptin. In conclusion, several mechanisms influence the degradation of GRK3 and therefore have the potential to affect GPCR signaling by regulating GRK3 levels in neurons

Smart Watch Detection of Supraventricular Tachycardia (SVT): First Case from Tanzania

Smartwatches like the Apple Watch have been on the rise worldwide and their use is gaining popularity in developing countries. Their ability to detect dysrhythmias is well documented. Present practice discourages the use of these devices as a diagnostic tool. Nevertheless, atypical findings from these devices should be clinically investigated. This case demonstrates an eventual diagnosis of supraventricular tachycardia (SVT) based on an Apple watch alert which was subsequently confirmed by electrophysiological evaluation

Effect of ischemia reperfusion on sodium-dependent phosphate transport in renal brush border membranes

AbstractThe effect of ischemia induced acute renal failure (ARF) on the transport of phosphate (Pi) after early (15–30 min) and prolonged (60 min) ischemia in the brush border membrane vesicles (BBMV) from rat renal cortex was studied. Sodium-dependent transport of Pi declined significantly and progressively due to ischemia. Western blot analysis of BBM from ischemic rats showed decreased expression of NaPi-2. A compensatory increase was observed in Pi uptake in BBMV from contralateral kidneys. There was no significant difference in NaPi-2 expression between BBMV from sham and contralateral kidneys. Early blood reperfusion for 15 min after 30 min ischemia caused further decline in Pi uptake. Prolonged reperfusion for 120 min caused partial reversal of transport activities in 30-min ischemic rats. However, no improvement in the transport of Pi was observed in 60-min ischemic rats after 120 min of blood reperfusion. Kinetic studies showed that the effect of ischemia and blood reperfusion was dependent on the Vmax of the Na-Pi transporter. Western blot analysis showed increased expression of NaPi-2 in the BBMs from ischemia–reperfusion animals. Further, a shift in the association of Na ions to transport one molecule of Pi was observed under different extracellular Na concentrations [Na]o. Feeding rats with low Pi diet and/or treatment with thyroid hormone (T3) prior to ischemia resulted in increased basal Pi transport. Ischemia caused similar decline in Pi transport in BBM from LPD and/or T3 animals. However, recovery in these animals was faster than the normal Pi diet fed (NPD) animals. The study suggests a change in the intrinsic properties of the Na-Pi transporter in rat kidneys due to ischemia. The study also indicates that treatment with T3 and feeding LPD prior to ischemia caused faster recovery of phosphate uptake due to ischemia–reperfusion injury

Factors Associated with Mortality Among Hospitalized Adults with COVID-19 Pneumonia at a Private Tertiary Hospital in Tanzania: A Retrospective Cohort Study

Background: The emergence of the novel coronavirus disease 2019 (COVID-19) has caused millions of deaths worldwide. There has been paucity of data for hospitalized African patients suffering from COVID-19. This study aimed to identify factors associated with in-hospital mortality in patients suffering from COVID-19 in Tanzania. Methods: This was a single center, retrospective, observational cohort study in adult patients hospitalized with confirmed COVID-19 infection. Demographics, clinical pattern, laboratory and radiological investigations associated with increased odds of mortality were analyzed. Results: Of the 157 patients, 107 (68.1%) patients survived and 50 (31.8%) died. Mortality was highest in patients suffering with severe (26%) and critical (68%) forms of the disease. The median age of the cohort was 52 years (IQR 42– 61), majority of patients were male (86%) and of African origin (46%), who presented with fever (69%), cough (62%) and difficulty in breathing (43%). Factors that were associated with mortality among our cohort were advanced age (OR 1.07, 95% CI 1.03– 1.11), being overweight and obese (OR 9.44, 95% CI 2.71– 41.0), suffering with severe form of the disease (OR 4.77, 95% CI 1.18– 25.0) and being admitted to the HDU and ICU (OR 6.68, 95% CI 2.06– 24.6). Conclusion: The overall in-hospital mortality was 31.8%. Older age, obesity, the severe form of the disease and admission to the ICU and HDU were major risk factors associated with in-hospital mortality

Postoperative myocardial injury in a patient with left ureteric stone and asymptomatic COVID-19 disease

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first identified on 8thDecember 2019 in Wuhan, Hubei, China, and has since spread globally to become an emergency of international concern. Patients infected with SARS-CoV-2 may be asymptomatic or present with symptoms ranging from mild clinical manifestations: such as fever, cough, and sore throat to moderate and severe form of the disease such as pneumonia and acute respiratory distress syndrome (ARDS). In some patients, SARS-CoV-2 can affect the heart and cause myocardial injury which is evidenced either by electrocardiographic (ECG) changes or by a rise in serum troponin level. Patients with myocardial involvement are generally at risk of developing severe illness and tend to have a poor outcome. We hereby present a case of a hypertensive male patient with undiagnosed, asymptomatic COVID-19, who underwent an emergency urologic procedure for ureteric calculi. He eventually sustained a postoperative myocardial injury resulting in his demise. This case highlights the importance of detailed preoperative assessment and anticipation of complications during this global pandemic

Assessment of total phenolic and flavonoid contents of selected fruits and vegetables

686-693This work was conceptualized with the goal to investigate different fruits and vegetables for their comparative investigation of total phenolic and total flavonoid contents. The total phenolic content of 9 fruits and 12 vegetables used in the current study was determined by Folin-Ciocalteau assay. In addition, total flavonoid content was identified through catechin and aluminum colorimetric analysis. The ratio among the phenolic and flavonoid contents of fruits and vegetables extracts were also analyzed. Our results showed that methanolic extract of Citrullus lanatus had higher contents of phenolics and flavonoids (215±1.24 mg GAE/100 g and 73±0.81 mg CE/100 g) than other fruits. Moreover, maturity process of fruits from unripened to fully ripened stage showed significant increase in the total phenolic and flavonoid contents. Fruits under study had shown flavonoids/phenolics ratio of 0.32, which indicates that these fruits contained about 32% of flavonoid contents. Among vegetables, the greatest value of phenolic contents was observed in Capsicum annuum (213±1.24 mg GAE/100 g), and total flavonoid content in Raphanus sativus (45±1.24 mg CE/100 g). Vegetables showed lower ratios of flavonoids/phenolics (0.11-0.2) indicating lesser total flavonoid content (11-20%) as compared with fruits. The obtained results indicate that fruits and vegetables could be attributed to a potential source of natural phenolics and flavonoids in the pharmaceutical and food industry. Moreover, the antioxidant activities of these selected fruits and vegetables should also be determined in order to explore their beneficial effects against the prevention and management of disorders caused by oxidative stress

Autoimmune and neuropsychiatric phenotypes in a Mecp2 transgenic mouse model on C57BL/6 background

IntroductionSystemic Lupus Erythematosus (SLE) impacts the central nervous system (CNS), leading to severe neurological and psychiatric manifestations known as neuropsychiatric lupus (NPSLE). The complexity and heterogeneity of clinical presentations of NPSLE impede direct investigation of disease etiology in patients. The limitations of existing mouse models developed for NPSLE obstruct a comprehensive understanding of this disease. Hence, the identification of a robust mouse model of NPSLE is desirable.MethodsC57BL/6 mice transgenic for human MeCP2 (B6.Mecp2Tg1) were phenotyped, including autoantibody profiling through antigen array, analysis of cellularity and activation of splenic immune cells through flow cytometry, and measurement of proteinuria. Behavioral tests were conducted to explore their neuropsychiatric functions. Immunofluorescence analyses were used to reveal altered neurogenesis and brain inflammation. Various signaling molecules implicated in lupus pathogenesis were examined using western blotting.ResultsB6.Mecp2Tg1 exhibits elevated proteinuria and an overall increase in autoantibodies, particularly in female B6.Mecp2Tg1 mice. An increase in CD3+CD4+ T cells in the transgenic mice was observed, along with activated germinal center cells and activated CD11b+F4/80+ macrophages. Moreover, the transgenic mice displayed reduced locomotor activity, heightened anxiety and depression, and impaired short-term memory. Immunofluorescence analysis revealed IgG deposition and immune cell infiltration in the kidneys and brains of transgenic mice, as well as altered neurogenesis, activated microglia, and compromised blood-brain barrier (BBB). Additionally, protein levels of various key signaling molecules were found to be differentially modulated upon MeCP2 overexpression, including GFAP, BDNF, Albumin, NCoR1, mTOR, and NLRP3.DiscussionCollectively, this work demonstrates that B6.Mecp2Tg1 mice exhibit lupus-like phenotypes as well as robust CNS dysfunctions, suggesting its utility as a new animal model for NPSLE

Assessment of total phenolic and flavonoid contents of selected fruits and vegetables

This work was conceptualized with the goal to investigate different fruits and vegetables for their comparative investigation of total phenolic and total flavonoid contents. The total phenolic content of 9 fruits and 12 vegetables used in the current study was determined by Folin-Ciocalteau assay. In addition, total flavonoid content was identified through catechin and aluminum colorimetric analysis. The ratio among the phenolic and flavonoid contents of fruits and vegetables extracts were also analyzed. Our results showed that methanolic extract of Citrullus lanatus had higher contents of phenolics and flavonoids (215±1.24 mg GAE/100 g and 73±0.81 mg CE/100 g) than other fruits. Moreover, maturity process of fruits from unripened to fully ripened stage showed significant increase in the total phenolic and flavonoid contents. Fruits under study had shown flavonoids/phenolics ratio of 0.32, which indicates that these fruits contained about 32% of flavonoid contents. Among vegetables, the greatest value of phenolic contents was observed in Capsicum annuum (213±1.24 mg GAE/100 g), and total flavonoid content in Raphanus sativus (45±1.24 mg CE/100 g). Vegetables showed lower ratios of flavonoids/phenolics (0.11-0.2) indicating lesser total flavonoid content (11-20%) as compared with fruits. The obtained results indicate that fruits and vegetables could be attributed to a potential source of natural phenolics and flavonoids in the pharmaceutical and food industry. Moreover, the antioxidant activities of these selected fruits and vegetables should also be determined in order to explore their beneficial effects against the prevention and management of disorders caused by oxidative stress