Genetic Variants Associated with the Risk of Stroke in Sickle Cell Anemia: Systematic Review and Meta-Analysis.

Sickle cell anemia (SCA) is the most common cause of stroke in children. As it is a rare disease, studies investigating the association with complications like stroke in SCD have small sample sizes. Here, we performed a systematic review and meta-analysis of the studies exploring an association of genetic variants with stroke to get a better indication of their association with stroke. PubMed and Google Scholar were searched to identify studies that had performed an association analysis of genetic variants for the risk of stroke in SCA patients. After screening of eligible studies, summary statistics of association analysis with stroke and other general information were extracted. Meta-analysis was performed using the fixed effect method on the tool METAL and forest plots were plotted using the R program. The random effect model was performed as a sensitivity analysis for loci where significant heterogeneity was observed. 407 studies were identified using the search term and after screening 37 studies that cumulatively analyzed 11,373 SCA patients were included. These 37 studies included a total of 2,222 SCA patients with stroke, predominantly included individuals of African ancestry (N = 16). Three of these studies performed whole exome sequencing while 35 performed single nucleotide-based genotyping. Though the studies reported association with 132 loci, meta-analyses could be performed only for 12 loci that had data from two or more studies. After meta-analysis we observed that four loci were significantly associated with risk for stroke: -α3.7 kb Alpha-thalassemia deletion (P = 0.00000027), rs489347-TEK (P = 0.00081), rs2238432-ADCY9 (P = 0.00085), rs11853426-ANXA2 (P = 0.0034), and rs1800629-TNF (P = 0.0003396). Ethnic representation of regions with a high prevalence of SCD like the Mediterranean basin and India needs to be improved for genetic studies on associated complications like stroke. Larger genome-wide collaborative studies on SCD and associated complications including stroke need to be performed.

Burden of communicable and non-communicable diseases-related inequalities among older adults in India: a study based on LASI survey.

BACKGROUND: A rising proportion of elderly in India has infused notable challenges to the healthcare system, which is already underdeveloped. On one side, NCDs are increasing among the elderly in India; however, on the other side, CDs are also a cause of concern among the elderly in India. While controlling the outbreak of communicable diseases (CDs) remained a priority, non-communicable diseases (NCDs) are placing an unavoidable burden on the health and social security system. India, a developing nation in South Asia, has seen an unprecedented economic growth in the past few years; however, it struggled to fight the burden of communicable and non-communicable diseases. Therefore, this study aimed at examining the burden of CDs and NCDs among elderly in India. METHODS: Data from Longitudinal Ageing Study in India (LASI Wave-I, 2017-18) were drawn to conduct this study. The LASI is a large-scale nationwide scientific study of the health, economics, and social determinants and implications of India's aged population. The LASI is a nationally representative survey of 72,250 aged 45 and over from all Indian states and union territories. Response variables were the occurrence of CDs and NCDs. The bi-variate and binary logistic regression were used to predict the association between communicable and non-communicable diseases by various socio-demographic and health parameters. Furthermore, to understand the inequalities of communicable and non-communicable diseases in urban and rural areas, the Fairlie decomposition technique was used to predict the contribution toward rural-urban inequalities in CDs and NCDs. RESULTS: Prevalence of communicable diseases was higher among uneducated elderly than those with higher education (31.9% vs. 17.3%); however, the prevalence of non-communicable diseases was higher among those with higher education (67.4% vs. 47.1%) than uneducated elderly. The odds of NCDs were higher among female elderly (OR = 1.13; C.I. = 1-1.27) than their male counterparts. Similarly, the odds of CDs were lower among urban elderly (OR = 0.70; C.I. = 0.62-0.81) than rural elderly, and odds of NCDs were higher among urban elderly (OR = 1.85; C.I. = 1.62-2.10) than their rural counterparts. Results found that education (50%) contributes nearly half of the rural-urban inequality in the prevalence of CDs among the elderly. Education status and current working status were the two significant predictors of widening rural-urban inequality in the prevalence of NCDs among the elderly. CONCLUSION: The burden of both CD and NCD among the elderly population requires immediate intervention. The needs of men and women and urban and rural elderly must be addressed through appropriate efforts. In a developing country like India, preventive measures, rather than curative measures of communicable diseases, will be cost-effective and helpful. Further, focusing on educational interventions among older adults might bring some required changes.

Procalcitonin as a predictive marker in COVID-19: A systematic review and meta-analysis.

BACKGROUND: Coronavirus disease 2019 has emerged as a global pandemic causing millions of critical cases and deaths. Early identification of at-risk patients is crucial for planning triage and treatment strategies. METHODS AND FINDINGS: We performed this systematic review and meta-analysis to determine the pooled prognostic significance of procalcitonin in predicting mortality and severity in patients with COVID-19 using a robust methodology and clear clinical implications. DESIGN: We used Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane Handbook for Systematic Reviews of Interventions guidelines. We included thirty-two prospective and retrospective cohort studies involving 13,154 patients. RESULTS: The diagnostic odds ratio of procalcitonin for predicting mortality were estimated to be 11 (95% CI: 7 to 17) with sensitivity, specificity, and summary area under the curveof 0.83 (95% CI: 0.70 to 0.91), 0.69 (95% CI: 0.58 to 0.79), and 0.83 (95% CI: 0.79 to 0.86) respectively. While for identifying severe cases of COVID-19, the odds ratio was 8.0 (95% CI 5.0 to 12.0) with sensitivity, specificity, and summary area under the curve of 0.73 (95% CI 0.67 to 0.78), 0.74 (0.66 to 0.81), and 0.78 (95% CI 0.74 to 0.82) respectively. CONCLUSION: Procalcitonin has good discriminatory power for predicting mortality and disease severity in COVID-19 patients. Therefore, procalcitonin measurement may help identify potentially severe cases and thus decrease mortality by offering early aggressive treatment.

"Association of Leptin with Polycystic Ovary Syndrome: a Systematic Review and Meta-Analysis".

BACKGROUND: Serum leptin has been considered as an important measurable diagnostic and prognostic biomarker for polycystic ovarian syndrome (PCOS), although its evidence for use in clinical practice is limited. We aim to synthesize the available evidence on the clinical use of serum leptin values in PCOS by doing a systematic review and meta-analysis of studies. OBJECTIVE: To conduct a meta-analysis to determine the pooled effect size of the association of leptin levels in patients with PCOS. METHODS: We searched electronic databases, i.e., PubMed, Google Scholar, Web of Science, ClinicalTrials.gov, and Medline from inception to September 2020, keeping filters for human studies and published in the English language. We used the random-effects model if heterogeneity between the studies was > 50%; otherwise, a fixed-effect model was applied to determine the standardized mean difference with 95% CI for comparison of leptin level between cases and controls. All the statistical analyses were completed using software STATA version 13. RESULTS: The meta-analysis included a total of 35 studies involving 2015 cases and 1767 controls that suggested statistically significantly higher leptin levels in the women with PCOS as compared to controls (SMD, 1.76, 95% CI 1.28 to 2.23, P < 0.001). In the stratified analysis when only high methodological quality studies were included, we did not observe a statistically significant difference in the leptin level between PCOS and controls (SMD 0.68, 95% CI -0.09 to 1.46). Analysis restricted to low methodological quality studies observed statistically significant high leptin levels in PCOS women as compared to controls (SMD 2.24, 95% CI 1.65 to 2.83). CONCLUSION: The available evidence suggests that elevated leptin levels may be associated with risk of PCOS as compared to controls; however, failure to observe the similar association in high methodological quality studies demands further well-designed adequately powered studies to validate the findings.

Stochastic heat engine using an active particle.

The topic of microscopic heat engine has undergone intensive research in recent years. Microscopic heat engines can exploit thermal as well as active fluctuations to extract thermodynamic work. We investigate the properties of a microscopic Stirling's engine that uses an active (self-propelling) particle as a working substance, in contact with two thermal baths. It is shown that the presence of activity leads to an enhanced performance of the engine. The efficiency can be improved by increasing the activity strength for all cycle time, including the nonquasistatic regime. We verify that the analytical results agree very well with our simulations. The variation of efficiency with the temperature difference between the two thermal baths has also been explored. The optimum region of operation of the engine has been deduced, by using its efficient power (product of efficiency and power) as a quantifier. Finally, a simple model is provided that emulates the behavior of a flywheel driven by this engine.