Ambient heat exposure patterns and emergency department visits and hospitalizations among medicare beneficiaries 2008-2019

OBJECTIVE

To assess the association between ambient heat and all-cause and cause-specific emergency department (ED) visits and acute hospitalizations among Medicare beneficiaries in the conterminous United States.

DESIGN

Retrospective cohort study.

SETTING

Conterminous US from 2008 and 2019.

PARTICIPANTS

2% random sample of all Medicare fee-for-service beneficiaries eligible for Parts A, B, and D.

MAIN OUTCOME MEASURES

All-cause and cause-specific (cardiovascular, renal, and heat-related) ED visits and unplanned hospitalizations were identified using primary ICD-9 or ICD-10 diagnosis codes. We measured the association between ambient temperature - defined as daily mean temperature percentile of summer (June through September) - and the outcomes. Hazard ratios and their associated 95% confidence intervals were estimated using multivariable Cox proportional hazards regression, adjusting for individual level demographics, comorbidities, healthcare utilization factors and zip-code level social factors.

RESULTS

Among 809,636 Medicare beneficiaries (58% female, 81% non-Hispanic White, 24% <65), older beneficiaries (aged ≥65) exposed to >95th percentile temperature had a 64% elevated adjusted risk of heat-related ED visits (HR [95% CI], 1.64 [1.46,1.85]) and a 4% higher risk of all-cause acute hospitalization (1.04 [1.01,1.06]) relative to <25th temperature percentile. Younger beneficiaries (aged <65) showed increased risk of heat-related ED visits (2.69 [2.23,3.23]) and all-cause ED visits (1.03 [1.01,1.05]). The associations with heat related events were stronger in males and individuals dually eligible for Medicare and Medicaid. No significant differences were observed by climatic region. We observed no significant relationship between temperature percentile and risk of CV-related ED visits or renal-related ED visits.

CONCLUSIONS

Among Medicare beneficiaries from 2008 to 2019, exposure to daily mean temperature ≥ 95th percentile was associated with increased risk of heat-related ED visits, with stronger associations seen among beneficiaries <65, males, and patients with low socioeconomic position. Further longitudinal studies are needed to understand the impact of heat duration, intensity, and frequency on cause-specific hospitalization outcomes.

Genome-wide mining of diversity and evolutionary signatures revealed selective hotspots in Indian Sahiwal cattle

The Sahiwal cattle breed is the best indigenous dairy cattle breed, and it plays a pivotal role in the Indian dairy industry. This is due to its exceptional milk-producing potential, adaptability to local tropical conditions, and its resilience to ticks and diseases. The study aimed to identify selective sweeps and estimate intrapopulation genetic diversity parameters in Sahiwal cattle using ddRAD sequencing-based genotyping data from 82 individuals. After applying filtering criteria, 78,193 high-quality SNPs remained for further analysis. The population exhibited an average minor allele frequency of 0.221 ± 0.119. Genetic diversity metrics, including observed (0.597 ± 0.196) and expected heterozygosity (0.433 ± 0.096), nucleotide diversity (0.327 ± 0.114), the proportion of polymorphic SNPs (0.726), and allelic richness (1.323 ± 0.134), indicated ample genomic diversity within the breed. Furthermore, an effective population size of 74 was observed in the most recent generation. The overall mean linkage disequilibrium (r2) for pairwise SNPs was 0.269 ± 0.057. Moreover, a greater proportion of short Runs of Homozygosity (ROH) segments were observed suggesting that there may be low levels of recent inbreeding in this population. The genomic inbreeding coefficients, computed using different inbreeding estimates (FHOM, FUNI, FROH, and FGROM), ranged from -0.0289 to 0.0725. Subsequently, we found 146 regions undergoing selective sweeps using five distinct statistical tests: Tajima's D, CLR, |iHS|, |iHH12|, and ROH. These regions, located in non-overlapping 500 kb windows, were mapped and revealed various protein-coding genes associated with enhanced immune systems and disease resistance (IFNL3, IRF8, BLK), as well as production traits (NRXN1, PLCE1, GHR). Notably, we identified interleukin 2 (IL2) on Chr17: 35217075-35223276 as a gene linked to tick resistance and uncovered a cluster of genes (HSPA8, UBASH3B, ADAMTS18, CRTAM) associated with heat stress. These findings indicate the evolutionary impact of natural and artificial selection on the environmental adaptation of the Sahiwal cattle population.

Clinicians Who Practice Primarily in Nursing Homes and the Quality of End-of-Life Care Among Residents

Importance

Clinician specialization in the care of nursing home (NH) residents or patients in skilled nursing facilities (SNFs) has become increasingly common. It is not known whether clinicians focused on NH care, often referred to as SNFists (ie, physicians, nurse practitioners, and physician assistants concentrating their practice in the NH or SNF setting), are associated with a reduced likelihood of burdensome transitions in the last 90 days of life for residents, which are a marker of poor-quality end-of-life (EOL) care.

Objective

To quantify the association between receipt of care from an SNFist and quality of EOL care for NH residents.

Design, Setting, and Participants

This cohort study analyzed Medicare fee-for-service claims for a nationally representative 20% sample of beneficiaries to examine burdensome transitions among NH decedents at the EOL from January 1, 2013, through December 31, 2019. Statistical analyses were conducted from December 2022 to June 2023.

Exposure

Receipt of care from an SNFist, defined as physicians and advanced practitioners who provided 80% or more of their evaluation and management visits in NHs annually.

Main Outcomes and Measures

This study used augmented inverse probability weighting in analyses of Medicare fee-for-service claims for a nationally representative 20% sample of beneficiaries. Main outcomes included 4 measures of burdensome transitions: (1) hospital transfer in the last 3 days of life; (2) lack of continuity in NHs after hospitalization in the last 90 days of life; (3) multiple hospitalizations in the last 90 days of life for any reason or any hospitalization for pneumonia, urinary tract infection, dehydration, or sepsis; and (4) any hospitalization in the last 90 days of life for an ambulatory care-sensitive condition.

Results

Of the 2 091 954 NH decedents studied (mean [SD] age, 85.4 [8.5] years; 1 470 724 women [70.3%]), 953 722 (45.6%) received care from SNFists and 1 138 232 (54.4%) received care from non-SNFists; 422 575 of all decedents (20.2%) experienced a burdensome transition at the EOL. Receipt of care by an SNFist was associated with a reduced risk of (1) hospital transfer in the last 3 days of life (-1.6% [95% CI, -2.5% to -0.8%]), (2) lack of continuity in NHs after hospitalization (-4.8% [95% CI, -6.7% to -3.0%]), and (3) decedents experiencing multiple hospitalizations for any reason or any hospitalization for pneumonia, urinary tract infection, dehydration, or sepsis (-5.8% [95% CI, -10.1% to -1.7%]). There was not a statistically significant association with the risk of hospitalization for an ambulatory care-sensitive condition in the last 90 days of life (0.0% [95% CI, -14.7% to 131.7%]).

Conclusions and Relevance

This study suggests that SNFists may be an important resource to improve the quality of EOL care for NH residents.

Building Climate Change into Medical Education: A Society of General Internal Medicine Position Statement

Building expertise in climate and planetary health among healthcare professionals cannot come with greater urgency as the threats from climate change become increasingly apparent. Current and future healthcare professionals-particularly internists-will increasingly need to understand the interconnectedness of natural systems and human health to better serve their patients longitudinally. Despite this, few national medical societies and accreditation bodies espouse frameworks for climate change and planetary health-related education at the undergraduate (UME), graduate (GME), and continuing (CME) medical education level. As a community of medical educators with an enduring interest in climate change and planetary health, the Society of General Internal Medicine (SGIM) recognizes the need to explicitly define structured educational opportunities and core competencies in both UME and GME as well as pathways for faculty development. In this position statement, we build from the related SGIM Climate and Health position statement, and review and synthesize existing position statements made by US-based medical societies and accreditation bodies that focus on climate change and planetary health-related medical education, identify gaps using Bloom's Hierarchy, and provide recommendations on behalf of SGIM regarding the development of climate and planetary health curricula development. Identified gaps include (1) limited systematic approach to climate and planetary health medical education at all levels; (2) minimal emphasis on learner-driven approaches; (3) limited focus on physician and learner well-being; and (4) limited role for health equity and climate justice. Recommendations include a call to relevant accreditation bodies to explicitly include climate change and planetary health as a competency, extend the structural competency framework to climate change and planetary health to build climate justice, proactively include learners in curricular development and teaching, and ensure resources and support to design and implement climate and planetary health-focused education that includes well-being and resiliency.

Ambient Heat and Risk of Serious Hypoglycemia in Older Adults With Diabetes Using Insulin in the U.S. and Taiwan: A Cross-National Case-Crossover Study

OBJECTIVE

To measure the association between ambient heat and hypoglycemia-related emergency department visit or hospitalization in insulin users.

RESEARCH DESIGN AND METHODS

We identified cases of serious hypoglycemia among adults using insulin aged ≥65 in the U.S. (via Medicare Part A/B/D-eligible beneficiaries) and Taiwan (via National Health Insurance Database) from June to September, 2016-2019. We then estimated odds of hypoglycemia by heat index (HI) percentile categories using conditional logistic regression with a time-stratified case-crossover design.

RESULTS

Among ∼2 million insulin users in the U.S. (32,461 hypoglycemia case subjects), odds ratios of hypoglycemia for HI >99th, 95-98th, 85-94th, and 75-84th percentiles compared with the 25-74th percentile were 1.38 (95% CI, 1.28-1.48), 1.14 (1.08-1.20), 1.12 (1.08-1.17), and 1.09 (1.04-1.13) respectively. Overall patterns of associations were similar for insulin users in the Taiwan sample (∼283,000 insulin users, 10,162 hypoglycemia case subjects).

CONCLUSIONS

In two national samples of older insulin users, higher ambient temperature was associated with increased hypoglycemia risk.

Risk Prediction for Atherosclerotic Cardiovascular Disease With and Without Race Stratification

Importance

Use of race-specific risk prediction in clinical medicine is being questioned. Yet, the most commonly used prediction tool for atherosclerotic cardiovascular disease (ASCVD)-pooled cohort risk equations (PCEs)-uses race stratification.

Objective

To quantify the incremental value of race-specific PCEs and determine whether adding social determinants of health (SDOH) instead of race improves model performance.

Design, Setting, and Participants

Included in this analysis were participants from the biracial Reasons for Geographic and Racial Differences in Stroke (REGARDS) prospective cohort study. Participants were aged 45 to 79 years, without ASCVD, and with low-density lipoprotein cholesterol level of 70 to 189 mg/dL or non-high-density lipoprotein cholesterol level of 100 to 219 mg/dL at baseline during the period of 2003 to 2007. Participants were followed up to 10 years for incident ASCVD, including myocardial infarction, coronary heart disease death, and fatal and nonfatal stroke. Study data were analyzed from July 2022 to February 2023.

Main outcome/measures

Discrimination (C statistic, Net Reclassification Index [NRI]), and calibration (plots, Nam D'Agostino test statistic comparing observed to predicted events) were assessed for the original PCE, then for a set of best-fit, race-stratified equations including the same variables as in the PCE (model C), best-fit equations without race stratification (model D), and best-fit equations without race stratification but including SDOH as covariates (model E).

Results

This study included 11 638 participants (mean [SD] age, 61.8 [8.3] years; 6764 female [58.1%]) from the REGARDS cohort. Across all strata (Black female, Black male, White female, and White male participants), C statistics did not change substantively compared with model C (Black female, 0.71; 95% CI, 0.68-0.75; Black male, 0.68; 95% CI, 0.64-0.73; White female, 0.77; 95% CI, 0.74-0.81; White male, 0.68; 95% CI, 0.64-0.71), in model D (Black female, 0.71; 95% CI, 0.67-0.75; Black male, 0.68; 95% CI, 0.63-0.72; White female, 0.76; 95% CI, 0.73-0.80; White male, 0.68; 95% CI, 0.65-0.71), or in model E (Black female, 0.72; 95% CI, 0.68-0.76; Black male, 0.68; 95% CI, 0.64-0.72; White female, 0.77; 95% CI, 0.74-0.80; White male, 0.68; 95% CI, 0.65-0.71). Comparing model D with E using the NRI showed a net percentage decline in the correct assignment to higher risk for male but not female individuals. The Nam D'Agostino test was not significant for all race-sex strata in each model series, indicating good calibration in all groups.

Conclusions

Results of this cohort study suggest that PCE performed well overall but had poorer performance in both BM and WM participants compared with female participants regardless of race in the REGARDS cohort. Removal of race or the addition of SDOH did not improve model performance in any subgroup.

Stable isotope labeling as a promising tool for rapid drug susceptibility testing in Neisseria gonorrhoeae

The world is heading towards an era of intractable and impending untreatable N. gonorrhoeae, thereby underlining the significance of rapid and accurate prediction of drug resistance as an indispensable need of the hour. In the present study, we optimized and evaluated a stable isotope labeling-based approach using the MALDI-TOF MS (Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry) for rapid and reliable detection of ciprofloxacin and azithromycin resistance in N. gonorrhoeae. All the isolates were cultured under three varied condition setups viz. medium supplemented with normal lysine, heavy lysine (isotope), and heavy lysine along with the antibiotics (ciprofloxacin/azithromycin), respectively. After incubation, spectra were acquired using the MALDI-TOF MS which were further screened for unique patterns (media-specific spectra) to differentiate drug-susceptible and resistant isolates. The results of the stable isotope labeling assay were comparable to the results of phenotypic methods used for susceptibility testing.

Risk stratification models for predicting preventable hospitalization in commercially insured late middle-aged adults with depression

BACKGROUND

A significant number of late middle-aged adults with depression have a high illness burden resulting from chronic conditions which put them at high risk of hospitalization. Many late middle-aged adults are covered by commercial health insurance, but such insurance claims have not been used to identify the risk of hospitalization in individuals with depression. In the present study, we developed and validated a non-proprietary model to identify late middle-aged adults with depression at risk for hospitalization, using machine learning methods.

METHODS

This retrospective cohort study involved 71,682 commercially insured older adults aged 55-64 years diagnosed with depression. National health insurance claims were used to capture demographics, health care utilization, and health status during the base year. Health status was captured using 70 chronic health conditions, and 46 mental health conditions. The outcomes were 1- and 2-year preventable hospitalization. For each of our two outcomes, we evaluated seven modelling approaches: four prediction models utilized logistic regression with different combinations of predictors to evaluate the relative contribution of each group of variables, and three prediction models utilized machine learning approaches - logistic regression with LASSO penalty, random forests (RF), and gradient boosting machine (GBM).

RESULTS

Our predictive model for 1-year hospitalization achieved an AUC of 0.803, with a sensitivity of 72% and a specificity of 76% under the optimum threshold of 0.463, and our predictive model for 2-year hospitalization achieved an AUC of 0.793, with a sensitivity of 76% and a specificity of 71% under the optimum threshold of 0.452. For predicting both 1-year and 2-year risk of preventable hospitalization, our best performing models utilized the machine learning approach of logistic regression with LASSO penalty which outperformed more black-box machine learning models like RF and GBM.

CONCLUSIONS

Our study demonstrates the feasibility of identifying depressed middle-aged adults at higher risk of future hospitalization due to burden of chronic illnesses using basic demographic information and diagnosis codes recorded in health insurance claims. Identifying this population may assist health care planners in developing effective screening strategies and management approaches and in efficient allocation of public healthcare resources as this population transitions to publicly funded healthcare programs, e.g., Medicare in the US.

The impact of commercial health datasets on medical research and health-care algorithms

As the health-care industry emerges into a new era of digital health driven by cloud data storage, distributed computing, and machine learning, health-care data have become a premium commodity with value for private and public entities. Current frameworks of health data collection and distribution, whether from industry, academia, or government institutions, are imperfect and do not allow researchers to leverage the full potential of downstream analytical efforts. In this Health Policy paper, we review the current landscape of commercial health data vendors, with special emphasis on the sources of their data, challenges associated with data reproducibility and generalisability, and ethical considerations for data vending. We argue for sustainable approaches to curating open-source health data to enable global populations to be included in the biomedical research community. However, to fully implement these approaches, key stakeholders should come together to make health-care datasets increasingly accessible, inclusive, and representative, while balancing the privacy and rights of individuals whose data are being collected.

Comparing Hospital Length of Stay Risk-Adjustment Models in US Value-Based Physician Payments

BACKGROUNG AND OBJECTIVES

Under the Affordable Care Act, the US Centers for Medicare & Medicaid Services created the Physician Value-Based Payment Modifier Program and its successor, the Merit-Based Incentive Payment System, to tie physician payments to quality and cost. The addition of hospital length of stay (LOS) to these value-based physician payment models reflects its increasing importance as a metric of health care cost and efficiency and its association with adverse health outcomes. This study compared the Centers for Medicare & Medicaid Services-endorsed LOS risk-adjustment methodology with a novel methodology that accounts for pre-hospitalization clinical, socioeconomic status (SES), and admission-related factors as influential factors of hospital LOS.

METHODS

Using the 2014 New York, Florida, and New Jersey State Inpatient Database, we compared the observed-to-expected LOS of 2373102 adult admissions for 742 medical and surgical diagnosis-related groups (DRGs) by 3 models: ( a ) current risk-adjustment model (CRM), which adjusted for age, sex, number of chronic conditions, Elixhauser comorbidity score, and DRG severity weight, ( b ) CRM but modeling LOS using a generalized linear model (C-GLM), and (c) novel risk-adjustment model (NRM), which added to the C-GLM covariates for race/ethnicity, SES, discharge destination, weekend admission, and individual intercepts for DRGs instead of severity weights.

RESULTS

The NRM disadvantaged physicians for fewer medical and surgical DRGs, compared with both the C-GLM and CRM models (medical DRGs: 0.49% vs 13.17% and 10.89%, respectively; surgical DRGs: 0.30% vs 13.17% and 10.98%, respectively). In subgroup analysis, the NRM reduced the proportion of physician-penalizing DRGs across all racial/ethnic and socioeconomic groups, with the highest reduction among Whites, followed by low SES patients, and the lowest reduction among Hispanic patients.

CONCLUSIONS

After accounting for pre-hospitalization socioeconomic and clinical factors, the adjusted LOS using the NRM was lower than estimates from the current Centers for Medicare & Medicaid Services-endorsed model. The current model may disadvantage physicians serving communities with higher socioeconomic risks.

Closing the Knowledge Gap in the Long-Term Health Effects of Natural Disasters: A Research Agenda for Improving Environmental Justice in the Age of Climate Change

Natural disasters continue to worsen in both number and intensity globally, but our understanding of their long-term consequences on individual and community health remains limited. As climate-focused researchers, we argue that a publicly funded research agenda that supports the comprehensive exploration of these risks, particularly among vulnerable groups, is urgently needed. This exploration must focus on the following three critical components of the research agenda to promote environmental justice in the age of climate change: (1) a commitment to long term surveillance and care to examine the health impacts of climate change over their life course; (2) an emphasis on interventions using implementation science frameworks; (3) the employment of a transdisciplinary approach to study, address, and intervene on structural disadvantage among vulnerable populations. Without doing so, we risk addressing these consequences in a reactive way at greater expense, limiting the opportunity to safeguard communities and vulnerable populations in the era of climate change.

Impact of Hurricanes and Associated Extreme Weather Events on Cardiovascular Health: A Scoping Review

BACKGROUND

The frequency and destructiveness of hurricanes and related extreme weather events (e.g., cyclones, severe storms) have been increasing due to climate change. A growing body of evidence suggests that victims of hurricanes have increased incidence of cardiovascular disease (CVD), likely due to increased stressors around time of the hurricane and in their aftermath.

OBJECTIVES

The objective was to systematically examine the evidence of the association between hurricanes (and related extreme weather events) and adverse CVD outcomes with the goal of understanding the gaps in the literature.

METHODS

A comprehensive literature search of population-level and cohort studies focused on CVD outcomes (i.e., myocardial infarction, stroke, and heart failure) related to hurricanes, cyclones, and severe storms was performed in the following databases from inception to December 2021: Ovid MEDLINE, Ovid EMBASE, Web of Science, and The Cochrane Library. Studies retrieved were then screened for eligibility against predefined inclusion/exclusion criteria. Studies were then qualitatively synthesized based on the time frame of the CVD outcomes studied and special populations that were studied. Gaps in the literature were identified based on this synthesis.

RESULTS

Of the 1,103 citations identified, 48 met our overall inclusion criteria. We identified articles describing the relationship between CVD and extreme weather, primarily hurricanes, based on data from the United States (42), Taiwan (3), Japan (2), and France (1). Outcomes included CVD and myocardial infarction-related hospitalizations (30 studies) and CVVD-related mortality (7 studies). Most studies used a retrospective study design, including one case-control study, 39 cohort studies, and 4 time-series studies.

DISCUSSION

Although we identified a number of papers that reported evaluations of extreme weather events and short-term adverse CVD outcomes, there were important gaps in the literature. These gaps included a) a lack of rigorous long-term evaluation of hurricane exposure, b) lack of investigation of hurricane exposure on vulnerable populations regarding issues related to environmental justice, c) absence of research on the exposure of multiple hurricanes on populations, and d) absence of an exploration of mechanisms leading to worsened CVD outcomes. Future research should attempt to fill these gaps, thus providing an important evidence base for future disaster-related policy. https://doi.org/10.1289/EHP11252.

Remote ischaemic conditioning: defining critical criteria for success-report from the 11th Hatter Cardiovascular Workshop

The Hatter Cardiovascular Institute biennial workshop, originally scheduled for April 2020 but postponed for 2 years due to the Covid pandemic, was organised to debate and discuss the future of Remote Ischaemic Conditioning (RIC). This evolved from the large multicentre CONDI-2-ERIC-PPCI outcome study which demonstrated no additional benefit when using RIC in the setting of ST-elevation myocardial infarction (STEMI). The workshop discussed how conditioning has led to a significant and fundamental understanding of the mechanisms preventing cell death following ischaemia and reperfusion, and the key target cyto-protective pathways recruited by protective interventions, such as RIC. However, the obvious need to translate this protection to the clinical setting has not materialised largely due to the disconnect between preclinical and clinical studies. Discussion points included how to adapt preclinical animal studies to mirror the patient presenting with an acute myocardial infarction, as well as how to refine patient selection in clinical studies to account for co-morbidities and ongoing therapy. These latter scenarios can modify cytoprotective signalling and need to be taken into account to allow for a more robust outcome when powered appropriately. The workshop also discussed the potential for RIC in other disease settings including ischaemic stroke, cardio-oncology and COVID-19. The workshop, therefore, put forward specific classifications which could help identify so-called responders vs. non-responders in both the preclinical and clinical settings.

Association between city-wide lockdown and COVID-19 hospitalization rates in multigenerational households in New York City

Background

City-wide lockdowns and school closures have demonstrably impacted COVID-19 transmission. However, simulation studies have suggested an increased risk of COVID-19 related morbidity for older individuals inoculated by house-bound children. This study examines whether the March 2020 lockdown in New York City (NYC) was associated with higher COVID-19 hospitalization rates in neighborhoods with larger proportions of multigenerational households.

Methods

We obtained daily age-segmented COVID-19 hospitalization counts in each of 166 ZIP code tabulation areas (ZCTAs) in NYC. Using Bayesian Poisson regression models that account for spatiotemporal dependencies between ZCTAs, as well as socioeconomic risk factors, we conducted a difference-in-differences study amongst ZCTA-level hospitalization rates from February 23 to May 2, 2020. We compared ZCTAs in the lowest quartile of multigenerational housing to other quartiles before and after the lockdown.

Findings

Among individuals over 55 years, the lockdown was associated with higher COVID-19 hospitalization rates in ZCTAs with more multigenerational households. The greatest difference occurred three weeks after lockdown: Q2 vs. Q1: 54% increase (95% Bayesian credible intervals: 22–96%); Q3 vs. Q1: 48% (17–89%); Q4 vs. Q1: 66% (30–211%). After accounting for pandemic-related population shifts, a significant difference was observed only in Q4 ZCTAs: 37% (7–76%).

Interpretation

By increasing house-bound mixing across older and younger age groups, city-wide lockdown mandates imposed during the growth of COVID-19 cases may have inadvertently, but transiently, contributed to increased transmission in multigenerational households.

Association Between Patient Diversity in Hospitals and Racial/Ethnic Differences in Patient Length of Stay

BACKGROUND

Hospitals serving a disproportionate share of racial/ethnic minorities have been shown to have poorer quality outcomes. It is unknown whether efficiencies in inpatient care, measured by length of stay (LOS), differ based on the proportion patients served by a hospital who are minorities.

OBJECTIVE

To examine the association between the racial/ethnic diversity of a hospital's patients and disparities in LOS.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

One million five hundred forty-six thousand nine hundred fifty-five admissions using the 2017 New York State Inpatient Database from the Healthcare Cost and Utilization Project.

MAIN MEASURE

Differences in mean adjusted LOS (ALOS) between White and Black, Hispanic, and Other (Asian, Pacific Islander, Native American, and Other) admissions by Racial/Ethnic Diversity Index (proportion of non-White patients admitted to total patients admitted to that same hospital) in quintiles (Q1 to Q5), stratified by discharge destination. Mean LOS was adjusted for patient demographic, clinical, and admission characteristics and for individual intercepts for each hospital.

KEY RESULTS

In both unadjusted and adjusted analysis, Black-White and Other-White mean LOS differences were smallest in the most diverse hospitals (Black-White: unadjusted, -0.07 days [-0.1 to -0.04], and adjusted, 0.16 days [95% CI: 0.16 to 0.16]; Other-White: unadjusted, -0.74 days [95% CI: -0.77 to -0.71], and adjusted, 0.01 days [95% CI: 0.01 to 0.02]). For Hispanic patients, in unadjusted analysis, the mean LOS difference was greatest in the most diverse hospitals (-0.92 days, 95% CI: -0.95 to -0.89) but after adjustment, this was no longer the case. Similar patterns across all racial/ethnic groups were observed after analyses were stratified by discharge destination.

CONCLUSION

Mean adjusted LOS differences between White and Black patients, and White and patients of Other race was smallest in most diverse hospitals, but not differences between Hispanic and White patients. These findings may reflect specific structural factors which affect racial/ethnic differences in patient LOS.

Predictors of life-threatening complications in relatively lower-risk patients hospitalized with COVID-19

Older individuals with chronic health conditions are at highest risk of adverse clinical outcomes from COVID-19, but there is widespread belief that risk to younger, relatively lower-risk individuals is negligible. We assessed the rate and predictors of life-threatening complications among relatively lower-risk adults hospitalized with COVID-19. Of 3766 adults hospitalized with COVID-19 to three hospitals in New York City from March to May 2020, 963 were relatively lower-risk based on absence of preexisting health conditions. Multivariable logistic regression models examined in-hospital development of life-threatening complications (major medical events, intubation, or death). Covariates included age, sex, race/ethnicity, hypertension, weight, insurance type, and area-level sociodemographic factors (poverty, crowdedness, and limited English proficiency). In individuals ≥55 years old (n = 522), 33.3% experienced a life-threatening complication, 17.4% were intubated, and 22.6% died. Among those <55 years (n = 441), 15.0% experienced a life-threatening complication, 11.1% were intubated, and 5.9% died. In multivariable analyses among those ≥55 years, age (OR 1.03 [95%CI 1.01–1.06]), male sex (OR 1.72 [95%CI 1.14–2.64]), being publicly insured (versus commercial insurance: Medicare, OR 2.02 [95%CI 1.22–3.38], Medicaid, OR 1.87 [95%CI 1.10–3.20]) and living in areas with relatively high limited English proficiency (highest versus lowest quartile: OR 3.50 [95%CI 1.74–7.13]) predicted life-threatening complications. In those <55 years, no sociodemographic factors significantly predicted life-threatening complications. A substantial proportion of relatively lower-risk patients hospitalized with COVID-19 experienced life-threatening complications and more than 1 in 20 died. Public messaging needs to effectively convey that relatively lower-risk individuals are still at risk of serious complications.

Association of ischemic electrocardiographic changes in high-altitude areas with coronary angiography

Background

Soldiers native to lowlands, while sojourning at high altitude (HA), are referred to tertiary care centers with electrocardiographic (ECG) abnormalities. Exposure to HA may precipitate myocardial ischemia in subjects with underlying coronary artery disease (CAD). Conversely, it may produce physiological ECG changes mimicking those of CAD, causing a diagnostic dilemma. This study sought to correlate the presence of CAD on coronary angiography (CAG) with a putative diagnosis of CAD based on clinical findings and ECG.

Methods

A prospective study was conducted on patient's from HA areas, referred for evaluation for CAD to a single center at near-sea-level. Thirty-five minimally symptomatic/asymptomatic soldiers with ECG changes suggestive of CAD, underwent CAG. Correlation was sought between ECG and CAG evidence of CAD.

Results

The association of CAD on CAG with clinical and ECG diagnosis of CAD was not significant, 4 of the 35 soldiers (11.4%) showing CAG evidence of CAD (chi square 3.849, p = 0.697). The association between symptoms and coronary artery lesions was, also, not significant, only four of twenty-three (17.4%) minimally symptomatic subjects having CAD on CAG.

Conclusion

Insignificant numbers of previously healthy persons, who present with minimal symptoms and ECG changes suggestive of CAD while sojourning at HA, have coronary artery involvement on CAG. Those with incidental ECG changes, without symptomatology, do not have CAD on CAG.

Association between overcrowded households, multigenerational households, and COVID-19: a cohort study

OBJECTIVES

The role of overcrowded and multigenerational households as a risk factor for COVID-19 remains unmeasured. The objective of this study is to examine and quantify the association between overcrowded and multigenerational households and COVID-19 in New York City (NYC).

STUDY DESIGN

Cohort study.

METHODS

We conducted a Bayesian ecological time series analysis at the ZIP Code Tabulation Area (ZCTA) level in NYC to assess whether ZCTAs with higher proportions of overcrowded (defined as the proportion of the estimated number of housing units with more than one occupant per room) and multigenerational households (defined as the estimated percentage of residences occupied by a grandparent and a grandchild less than 18 years of age) were independently associated with higher suspected COVID-19 case rates (from NYC Department of Health Syndromic Surveillance data for March 1 to 30, 2020). Our main measure was an adjusted incidence rate ratio (IRR) of suspected COVID-19 cases per 10,000 population. Our final model controlled for ZCTA-level sociodemographic factors (median income, poverty status, White race, essential workers), the prevalence of clinical conditions related to COVID-19 severity (obesity, hypertension, coronary heart disease, diabetes, asthma, smoking status, and chronic obstructive pulmonary disease), and spatial clustering.

RESULTS

39,923 suspected COVID-19 cases were presented to emergency departments across 173 ZCTAs in NYC. Adjusted COVID-19 case rates increased by 67% (IRR 1.67, 95% CI = 1.12, 2.52) in ZCTAs in quartile four (versus one) for percent overcrowdedness and increased by 77% (IRR 1.77, 95% CI = 1.11, 2.79) in quartile four (versus one) for percent living in multigenerational housing. Interaction between both exposures was not significant (β_interaction = 0.99, 95% CI: 0.99-1.00).

CONCLUSIONS

Overcrowdedness and multigenerational housing are independent risk factors for suspected COVID-19. In the early phase of the surge in COVID cases, social distancing measures that increase house-bound populations may inadvertently but temporarily increase SARS-CoV-2 transmission risk and COVID-19 disease in these populations.

Association Between Racial Disparities in Hospital Length of Stay and the Hospital Readmission Reduction Program

Background:

On average Black patients have longer LOS than comparable White patients. Longer hospital length of stay (LOS) may be associated with higher readmission risk. However, evidence suggests that the Hospital Readmission Reduction Program (HRRP) reduced overall racial differences in 30-day adjusted readmission risk. Yet, it is unclear whether the HRRP narrowed these LOS racial differences.

Objective:

We examined the relationship between Medicare-insured Black-White differences in average, adjusted LOS (ALOS) and the HRRP’s implementation and evaluation periods.

Methods:

Using 2009-2017 data from State Inpatient Dataset from New York, New Jersey, and Florida, we employed an interrupted time series analysis with multivariate generalized regression models controlling for patient, disease, and hospital characteristics. Results are reported per 100 admissions.

Results:

We found that for those discharged home, Black-White ALOS differences significantly widened by 4.15 days per 100 admissions (95% CI: 1.19 to 7.11, P < 0.001) for targeted conditions from before to after the HRRP implementation period, but narrowed in the HRRP evaluation period by 1.84 days per 100 admissions for every year-quarter (95% CI: −2.86 to −0.82, P < 0.001); for those discharged to non-home destinations, there was no significant change between HRRP periods, but ALOS differences widened over the study period. Black-White ALOS differences for non-targeted conditions remained unchanged regardless of HRRP phase and discharge destination.

Conclusion:

Increased LOS for Black patients may have played a role in reducing Black-White disparities in 30-day readmission risks for targeted conditions among patients discharged to home.

Association between overcrowded households, multigenerational households, and COVID-19: a cohort study

Introduction

The role of overcrowded and multigenerational households as a risk factor for COVID-19 remains unmeasured. The objective of this study is to examine and quantify the association between overcrowded and multigenerational households, and COVID-19 in New York City (NYC).

Methods

We conducted a Bayesian ecological time series analysis at the ZIP Code Tabulation Area (ZCTA) level in NYC to assess whether ZCTAs with higher proportions of overcrowded (defined as proportion of estimated number of housing units with more than one occupant per room) and multigenerational households (defined as the estimated percentage of residences occupied by a grandparent and a grandchild less than 18 years of age) were independently associated with higher suspected COVID-19 case rates (from NYC Department of Health Syndromic Surveillance data for March 1 to 30, 2020). Our main measure was adjusted incidence rate ratio (IRR) of suspected COVID-19 cases per 10,000 population. Our final model controlled for ZCTA-level sociodemographic factors (median income, poverty status, White race, essential workers), prevalence of clinical conditions related to COVID-19 severity (obesity, hypertension, coronary heart disease, diabetes, asthma, smoking status, and chronic obstructive pulmonary disease), and spatial clustering.

Results

39,923 suspected COVID-19 cases presented to emergency departments across 173 ZCTAs in NYC. Adjusted COVID-19 case rates increased by 67% (IRR 1.67, 95% CI = 1.12, 2.52) in ZCTAs in quartile four (versus one) for percent overcrowdedness and increased by 77% (IRR 1.77, 95% CI = 1.11, 2.79) in quartile four (versus one) for percent living in multigenerational housing. Interaction between both exposures was not significant (β _interaction = 0.99, 95% CI: 0.99-1.00).

Conclusions

Over-crowdedness and multigenerational housing are independent risk factors for suspected COVID-19. In the early phase of surge in COVID cases, social distancing measures that increase house-bound populations may inadvertently but temporarily increase SARS-CoV-2 transmission risk and COVID-19 disease in these populations.

Racial/ethnic and socioeconomic variations in hospital length of stay: A state-based analysis

Disparities by race/ethnicity and socioeconomic status (SES) exist in rehospitalization rates and inpatient mortality rates. Few studies have examined how length of stay (LOS, a measure of hospital efficiency/quality) differs by race/ethnicity and SES.This study's objective was to determine whether differences in risk-adjusted LOS exist by race/ethnicity and SESUsing a retrospective cohort of 1,432,683 medical and surgical discharges, we compared risk-adjusted LOS, in days, by race/ ethnicity and SES (median household income by patient ZIP code in quartiles), using generalized linear models controlling for demographic and clinical factors, and differences between hospitals and between diagnoses.White patients were on average older than both Black and Hispanic patients, had more chronic conditions, and had a higher inpatient mortality risk. In adjusted analyses, Black patients had a significantly longer LOS than White patients (0.25-day difference when discharged to home and 0.23-day difference when discharged to non-home destinations, both P<.001); there was no difference between Hispanic and White patients. Wealthier patients had a shorter LOS than poorer patients (0.16-day difference when discharged to home and 0.06-day difference when discharged to nonhome destinations, both P<.001). These differences by race/ethnicity reversed for Medicaid patients.Disparities in LOS exist based on a patient's race/ethnicity and SES. Black and poorer patients, but not Hispanic patients, have longer LOS compared to White and wealthier patients. In aggregate, these differences may be related to trust and implicit bias and have implications for use of LOS as a quality metric. Future research should examine the drivers of these disparities.

Trends in Medical and Surgical Admission Length of Stay by Race/Ethnicity and Socioeconomic Status: A Time Series Analysis

BACKGROUND

Length of stay (LOS), a metric of hospital efficiency, differs by race/ethnicity and socioeconomic status (SES) and longer LOS is associated with adverse health outcomes. Historically, projects to improve LOS efficiency have yielded LOS reductions by 0.3 to 0.7 days per admission.

OBJECTIVE

To assess differences in average adjusted length of stay (aALOS) over time by race/ethnicity, and SES stratified by discharge destination (home or non-home).

METHOD

Data were obtained from 2009-2014 Healthcare Cost and Utilization Project State Inpatient Datasets for New York, New Jersey, and Florida. Multivariate generalized linear models were used to examine trends in aALOS differences by race/ethnicity, and by high vs low SES patients (defined first vs fourth quartile of median income by zip code) controlling for patient, disease and hospital characteristics.

RESULTS

For those discharged home, racial/ethnic and SES aALOS differences remained stable from 2009 to 2014. However, among those discharged to non-home destinations, Black vs White aALOS differences increased from 0.21 days in Q1 2009, (95% confidence interval (CI): 0.13 to 0.30) to 0.32 days in Q3 2013, (95% CI: 0.23 to 0.40), and for low vs high SES patients from 0.03 days in Q1 2009 (95% CI: -0.04 to 0.1) to 0.26 days, (95% CI: 0.19 to 0.34). Notably, for patients not discharged home, racial/ethnic and SES aALOS differences increased and persisted after Q3 2011, coinciding with the introduction of the Affordable Care Act (ACA).

CONCLUSION

Further research to understand the ACA's policy impact on hospital efficiencies, and relationship to racial/ethnic and SES differences in LOS is warranted.

Roles of Re-entrant cluster glass state and spin-lattice coupling in magneto-dielectric behavior of giant dielectric double perovskite La1.8Pr0.2CoFeO6

La based Co-Fe combined double perovskite (La1.8Pr0.2CoFeO6) was synthesized and the dielectric (zero-field and in-field), magnetic, x-ray absorption and Raman spectroscopy measurements have been investigated for La1.8Pr0.2CoFeO6double perovskite. The existence of re-entrant cluster glass state is observed. The magneto-dielectric (MD) is found in two temperature regions (25-80 K and 125-275 K). It has been demonstrated that the observed MD at low and high temperatures are respectively due to the spin freezing and the spin-lattice coupling. Furthermore, the very large dielectric constant and the low loss suggest that La1.8Pr0.2CoFeO6is very important from the application point of view.

Extraordinary magnetic properties of double perovskite Eu2CoMnO6wide band gap semiconductor

Some novel magnetic behaviours in double perovskite Eu2CoMnO6(ECMO) have been reported. The x-ray photoemission spectroscopy study shows the presence of mixed valence states of transition metal ions. The UV-visible absorption spectroscopic study suggests that the ECMO has a direct wide band gap. A second-order magnetic phase transition as a sudden jump in the magnetization curve has been observed around 124.5 K. The large bifurcation between the zero field cooling and field cooling, suggests existence of strong spin frustration in the system. The inverse DC susceptibility confirms the presence of the Griffiths like phase. Sharp steps in magnetization have been observed in theM-Hcurve at 2 K, which vanishes on increasing temperature. The AC susceptibility study demonstrates the Hopkinson like effect as well as the presence of volume spin-glass-like behaviour. The temperature dependent Raman spectrum shows the presence of spin-phonon coupling.

Beta-estradiol protects against copper-ascorbate induced oxidative damage in goat liver mitochondria in vitro by binding with ascorbic acid

AIMS

β-Estradiol (β-E), one of the chemical forms of female gonad hormone exhibited antioxidant efficacy in biochemical system, in vitro. The aim of the study was to investigate whether any other mechanism of protection by β-E to hepatic mitochondria in presence of stressor agent i.e.,a combination of Cu²⁺ and ascorbic acid is involved.

MAIN METHODS

Freshly prepared goat liver mitochondria was incubated with stressors and 1 μM β-E and post incubated with the same concentration at 37 °C at pH 7.4. Mitochondrial viability, biomarkers of oxidative stress, activities of Krebs cycle enzymes, mitochondrial membrane potential, Ca²⁺ permeability were measured. Mitochondrial morphology and binding pattern of β-E with stressors were also studied.

KEY FINDINGS

Upon incubation of mitochondria with Cu, ascorbic acid and their combination there is a significant decline in activities of four of Krebs cycle enzymes in an uncompetitive manner with a concomitant increase in Ca²⁺ permeability and membrane potential of inner mitochondrial membrane, which is withdrawn during co-incubation with β-E, but was not reversed during post incubation with the β-E. The final studies on mitochondrial membrane morphology using scanning electron microscope also exhibited damage. Isothermal titration calorimetry data also showed the negative heat change in the mixture of β-E with ascorbic acid and also its combination with Cu²⁺.

SIGNIFICANCE

Our results for the first time demonstrated that β-E protects againstCu²⁺-ascorbate induced oxidative stress by binding with ascorbic acid. The new mechanism of binding of β-E with stress agents may have a future therapeutic relevance.

Anomalous Hall effect in Cu doped Bi2Te3 topological insulator

The angle resolved photo-emission spectroscopy (ARPES) study and magneto-transport properties of Bi2Cu x Te3-x have been investigated. ARPES study indicates the clear existence of surface states in the as-prepared samples. The estimated bandgap from ARPES is found to be ∼5 meV and 16 meV respectively for x = 0.03 and x = 0.15 samples. Presence of larger Cu concentration (x = 0.15) introduces magnetic ordering. Observed non-linearity in the Hall data is due to the existence of anomalous Hall effect which can be attributed to the 2D transport. The observed magneto-transport features might be related to the surface carriers which is confirmed by ARPES study.

P680The clinical value of CMR in the management of Cardio-Oncology patients - a tertiary centre experience

Background

There is increasing awareness of cardiotoxicity arising from cancer treatments. Early diagnosis and treatment is key, to ensure patients receive optimal oncological management. Cardiovascular magnetic resonance (CMR) offers gold standard measurement of cardiac function, alongside tissue characterisation and myocardial perfusion, thereby potentially providing additive value in the context of cardio-oncology.

Purpose

We sought to understand the clinical value of CMR in cardio-oncology at a tertiary cardio-oncology centre.

Methods

We retrospectively reviewed CMR scans requested in cardio-oncology patients at our institution within a ten-month period. We categorised clinical indications and assessed the impact on clinical management using previously-published criteria.

Results

102 CMR studies were requested in 93 cardio-oncology patients (mean age 56 (range 18 to 82), 49% male) between (March to December 2018). 41% of patients had haematological malignancies, 59% solid tumours.

15% of requests were for risk stratification prior to initiation of cancer therapy, 21% for screening for cardio-toxicity in patients currently receiving cardiotoxic agents (3% anthracyclines, 13% HER2 monoclonal antibodies, 4% fluoropyrimidines), 15% for investigation of patients with cardiac complications during cancer treatment, 35% assessment for late effects post cancer treatment, and 14% for cardiac malignancies/ infiltration.

The most common indications for CMR were monitoring of left ventricular ejection fraction (LVEF) in patients where quantification by echocardiography was non-diagnostic or significantly different between imaging studies (39%) and ischaemia assessment including for patients due to receive fluoropyrimidines (26%). Others were aetiology of LV dysfunction/cardiomyopathy (13%) and tissue characterisation (23%), including assessment for cardiac AL amyloid (11 patients), myocarditis (2), cardiac metastases (1), cardiac masses (6), and cardiac iron loading (1).

CMR findings had clinical impact in 61% of patients and assisted in adjudicating a new diagnosis in 29% of patients. 88% of patients were able to continue anthracycline/anti-HER2 therapies based on CMR findings of stable LVEF (93% of whose echocardiograms had suggested reductions). LVEF had reduced significantly in 12% of patients meaning chemotherapy was held/discontinued. 3 patients were recommended to receive non-fluoropyrimidine chemotherapy based on perfusion CMR (pCMR) findings, with one patient permitted to receive capecitabine following normal pCMR.

Conclusion

CMR provides a comprehensive assessment of myocardial structure and function with utility within the context of cardio-oncology for risk stratification pre-chemotherapy, screening for cardiotoxicity during treatment and investigation of cardiac complications of cancer treatment. The additional information derived from CMR generally provides reassurance enabling administration of optimal cancer therapies.

Investigation of multi-mode spin-phonon coupling and local B-site disorder in Pr2CoFeO6 by Raman spectroscopy and correlation with its electronic structure by XPS and XAS studies

Electronic structure of Pr₂CoFeO₆ (at 300 K) was investigated by x-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy techniques. All three cations, i.e. Pr, Co and Fe were found to be trivalent in nature. XPS valance band analysis suggested the system to be insulating in nature. The analysis suggested that Co³⁺ ions exist in low spin state in the system. Moreover, Raman spectroscopy study indicated the random distribution of the B-site ions (Co/Fe) triggered by same charge states. In temperature-dependent Raman study, the relative heights of the two observed phonon modes exhibited anomalous behaviour near magnetic transition temperature T _N ~ 270 K, thus indicating towards interplay between spin and phonon degrees of freedom in the system. Furthermore, clear anomalous softening was observed below T _N which confirmed the existence of strong spin-phonon coupling occurring for at least two phonon modes of the system. The line width analysis of the phonon modes essentially ruled out the role of magnetostriction effect in the observed phonon anomaly. The investigation of the lattice parameter variation across T _N (obtained from the temperature-dependent neutron diffraction measurements) further confirmed the existence of the spin-phonon coupling.

Synthesis and Biological Assessment of Pyrrolobenzoxazine Scaffold as a Potent Antioxidant

Reduction of mitochondrial oxidative stress-mediated diseases is an important pharmaceutical objective in recent biomedical research. In this context, a series of novel pyrrolobenzoxazines (PyBs) framework with enormous diversity (compounds 5a-w) was synthesized by employing a low-temperature greener pathway, and antioxidant property of the synthesized compounds was successfully demonstrated on preclinical model goat heart mitochondria, in vitro. Copper-ascorbate (Cu-As) was utilized as an oxidative stress generator. Out of screened PyBs, the compound possessing -OH and -OMe groups on benzene nucleus along with pyrrolobenzoxazine core moiety (compound 5w) displayed magnificent antioxidant property with a minimum effective dose of 66 μM during the biochemical assessment. The ameliorative effect of synthesized pyrrolobenzoxazine moiety on levels of biomarkers of oxidative stress, antioxidant enzyme, activities of Krebs cycle and respiratory chain enzymes, mitochondrial morphology, and Ca²⁺ permeability of mitochondrial membrane was investigated in the presence of Cu-As. Furthermore, the binding mode of Cu-As by compound 5w was explored successfully using isothermal titration calorimetry (ITC) analysis.

Identification of Malassezia species by MALDI-TOF MS after expansion of database

The taxonomy of Malassezia species is evolving with introduction of molecular techniques, and difficulty is faced to identify the species by phenotypic methods. Among 15 known Malassezia species, the present Bruker database could identify only 2 species. The present study was aimed to improve Matrix -assisted laser desorption ionization time-flight mass spectrometry (MALDI-TOF MS) based identification of Malassezia species. A total of 88 isolates (DNA sequencing confirmed) for database preparation and, for the validation of database, 190 isolates confirmed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) were used. The main spectrum profile dendrogram showed the sufficient discrimination between all the species by MALDI-TOF MS. The updated Malassezia database could identify 94.7% and 5.3% strains to the species and genus level, respectively. MALDI-TOF MS is a significantly reliable technique, and results were comparable with PCR-RFLP with kappa value 0.9. In conclusion, MALDI-TOF MS could be a possible alternative tool to other molecular methods for rapid and accurate identification of Malassezia species.

Mechanism of melatonin protection against copper-ascorbate-induced oxidative damage in vitro through isothermal titration calorimetry

AIMS

Involvement of oxidative stress in cardiovascular diseases is well established. Melatonin's role as an antioxidant and free radical scavenger via its receptor dependent and receptor independent pathways is well known. The aim of this study is to identify and elaborate upon a third mechanism by which melatonin is able to abrogate oxidative stress.

MAIN METHODS

Oxidative stress was induced in vitro, by copper (0.2mM)-ascorbate (1mM) in isolated goat heart mitochondria, cytosol and peroxisomes and they were co-incubated with graded doses of melatonin. Similar experiments in a cell-free chemical system involving two pure antioxidant enzymes, Cu-Zn superoxide dismutase and catalase was also carried out. Biochemical changes in activity of these antioxidant enzymes were analysed. Isothermal titration calorimetric studies with pure Cu-Zn superoxide dismutase and catalase were also carried out.

KEY FINDINGS

Incubation with copper-ascorbate led to alteration in activity of Cu-Zn superoxide dismutase and catalase which were found to be protected upon co-incubation with melatonin (80μM for catalase and 1μM for others). Results of isothermal titration calorimetric studies with pure Cu-Zn superoxide dismutase and catalase along with different combinations of copper chloride, ascorbic acid and melatonin suggest that when melatonin is present in the reaction medium along with copper-ascorbate, it restrains the copper-ascorbate molecules by binding with them physically along with scavenging the free radicals generated by them.

SIGNIFICANCE

The present study suggests that possibly, binding of melatonin with antioxidant enzymes masks the vulnerable sites of these antioxidant enzymes, thus preventing oxidative damage by copper-ascorbate molecules.

Biosynthesis and characterization of gold nanoparticles: Kinetics, in vitro and in vivo study

This study reports a facile, cost effective, nontoxic and eco-friendly method for the synthesis of gold nanoparticles. In this paper, leaf extract of Mentha piperita was successfully used to reduce chloroauric acid, leading to synthesis of gold nanoparticles (AuNPs). The synthesized nanoparticles were further characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy and field emission scanning electron microscopy. Kinetics studies like effect of volume of leaf extract, precursor, pH, temperature for the synthesis of AuNPs were studied spectrophotometrically. Synthesized AuNPs were found to possess hexagon structure where size of nanoparticles was ~78nm in diameter. These biologically synthesized AuNPs exhibited significant activity against cancerous cell lines MDA-MB-231 and A549 and was compared with the normal 3T3-L1 cell line. Anti-inflammatory and analgesic activities were studied on a Wistar rat model to gauge the impact of AuNPs for a probable role in these applications. AuNPs gave positive results for both these activities, although the potency was less as compared to the standard drugs. These results suggested that the leaves extract of Mentha piperita is a very good bioreductant for the synthesis of AuNPs and have potential for various biomedical and pharmaceutical applications.

Large power factor and anomalous Hall effect and their correlation with observed linear magneto resistance in Co-doped Bi2Se3 3D topological insulator

Magnetoresistance (MR), thermo power, magnetization and Hall effect measurements have been performed on Co-doped Bi2Se3 topological insulators. The undoped sample shows that the maximum MR as a destructive interference due to a π-Berry phase leads to a decrease of MR. As the Co is doped, the linearity in MR is increased. The observed MR of Bi2Se3 can be explained with the classical model. The low temperature MR behavior of Co doped samples cannot be explained with the same model, but can be explained with the quantum linear MR model. Magnetization behavior indicates the establishment of ferromagnetic ordering with Co doping. Hall effect data also supports the establishment of ferromagnetic ordering in Co-doped Bi2Se3 samples by showing the anomalous Hall effect. Furthermore, when spectral weight suppression is insignificant, Bi2Se3 behaves as a dilute magnetic semiconductor. Moreover, the maximum power factor is observed when time reversal symmetry (TRS) is maintained. As the TRS is broken the power factor value is decreased, which indicates that with the rise of Dirac cone above the Fermi level the anomalous Hall effect and linearity in MR increase and the power factor decreases.

Dynamics of microvesicle generation in B-cell chronic lymphocytic leukemia: implication in disease progression

Previously, we reported that B-cell chronic lymphocytic leukemia (CLL) patients contained elevated levels of microvesicles (MVs). However, given the quiescent nature of CLL B-cells and the relative indolence of the disease, the dynamics of MV generation and their unique phenotypes are not clearly defined. In this study, we find that CLL B-cells generate MVs spontaneously and can be further induced by B-cell receptor-ligation. Most interestingly, CLL B-cells predominantly generate CD52⁺ MVs, but not CD19⁺ MVs in vitro, suggesting preferential usage of CD52 into leukemic-MVs and that the CLL plasma MV phenotypes corroborate well with the in vitro findings. Importantly, we detected increased accumulation of CD52⁺ MVs in previously untreated CLL patients with progressive disease. Finally, sequential studies on MVs in pre- and post-therapy CLL patients demonstrate that while the plasma CD52⁺ MV levels drop significantly after therapy in most and remain at low levels in some patients, a trend of increased accumulation of CD52⁺ MVs was detected in majority of post-therapy CLL patients (25 of 33). In total this study emphasizes that dynamic accumulation of CD52⁺ MVs in plasma can be used to study CLL progression and may be a useful biomarker for patients as they progress and require therapy.

Using chlamydia positivity to estimate prevalence: evidence from the Chlamydia Screening Pilot in England

Studies have suggested that positivity can be used to estimate the prevalence of Chlamydia trachomatis in large-scale chlamydia screening programmes. A recent pilot of opportunistic screening in England estimated that the prevalence among 16–24-year-old women in Portsmouth and Wirral was 9.8% and 11.2%, respectively. This study assessed the continued validity of positivity as an approximate for prevalence. We re-analysed data from the Chlamydia Screening Pilot to estimate positivity, calculated as total positive tests divided by total tests, and compared these estimates with the previously reported prevalence, measured as the number of women testing positive divided by the total number of women screened. Overall positivity was 9.4% in Portsmouth and 11.0% in the Wirral; these estimates were not statistically different from prevalence, regardless of health-care setting, age group or symptoms. We conclude that positivity can be used as a proxy for prevalence.

The prevalence of abnormal ECG in trained sportsmen

BACKGROUND

Competitive sports training causes structural and conductive system changes manifesting by various electrocardiographic alterations. We undertook this study to assess the prevalence of abnormal ECG in trained Indian athletes and correlate it with the nature of sports training, that is endurance or strength training.

METHODS

We evaluated a standard resting, lying 12 lead Electrocardiogram (ECG) in 66 actively training Indian athletes. Standard diagnostic criteria were used to define various morphological ECG abnormalities.

RESULTS

33/66 (50%) of the athletes were undertaking endurance training while the other 33 (50%) were involved in a strength-training regimen. Overall 54/66 (81%) sportsmen had significant ECG changes. 68% of these changes were considered as normal training related features, while the remaining 32% were considered abnormal. There were seven common training related ECG changes-Sinus Bradycardia (21%), Sinus Arrhythmia (16%), 1st degree Atrioventricular Heart Block (6%), Type 1 2nd-degree Atrioventicular Heart Block (3%), Incomplete Right bundle branch block (RBBB) (24%), Early Repolarization (42%), Left Ventricular Hypertrophy (LVH) (14%); while three abnormal ECG changes--T-wave inversion (13%), RBBB(4%), Right ventricular hypertrophy (RVH) with strain (29%) were noted. Early repolarization (commonest change), sinus bradycardia, and incomplete RBBB were the commoner features noticed, with a significantly higher presence in the endurance trained athletes.

CONCLUSION

A high proportion of athletes undergoing competitive level sports training are likely to have abnormal ECG recordings. Majority of these are benign, and related to the physiological adaptation to the extreme levels of exertion. These changes are commoner during endurance training (running) than strength training (weightlifting).

Mechanisms of isoproterenol-induced cardiac mitochondrial damage: protective actions of melatonin

Mitochondrial dysfunction due to oxidative damage is the key feature of several diseases. We have earlier reported mitochondrial damage resulting from the generation of oxidative stress as a major pathophysiological effect of isoproterenol (ISO)-induced myocardial ischemia in rats. That melatonin is an antioxidant that ameliorates oxidative stress in experimental animals as well as in humans is well established. We previously demonstrated that melatonin provides cardioprotection against ISO-induced myocardial injury as a result of its antioxidant properties. The mechanism of ISO-induced cardiac mitochondrial damage and protection by melatonin, however, remains to be elucidated in vitro. In this study, we provide evidence that ISO causes dysfunction of isolated goat heart mitochondria. Incubation of cardiac mitochondria with increasing concentrations of ISO decreased mitochondrial succinate dehydrogenase (SDH) activity, which plays a pivotal role in mitochondrial bioenergetics, as well as altered the activities of other key enzymes of the Kreb's cycle and the respiratory chain. Co-incubation of ISO-challenged mitochondria with melatonin prevented the alterations in enzyme activity. That these changes in mitochondrial energy metabolism were due to the perpetration of oxidative stress by ISO was evident from the increased levels of lipid peroxidation and decreased reduced glutathione/oxidized glutathione ratio. ISO-induced oxidative stress also altered mitochondrial redox potential and brought about changes in the activity of the antioxidant enzymes manganese superoxide dismutase and glutathione peroxidase, eventually leading to alterations in total ATPase activity and membrane potential. Melatonin ameliorated these changes likely through its antioxidant abilities suggesting a possible mechanism of cardioprotection by this indole against ISO-induced myocardial injury.

Structural, transport and optical properties of (La0.6Pr0.4)0.65Ca0.35MnO3 nanocrystals: a wide band-gap magnetic semiconductor

(La0.6Pr0.4)0.65Ca0.35MnO3 system has been synthesized via a sol-gel route at different sintering temperatures. Structural, transport and optical measurements have been carried out to investigate (La0.6Pr0.4)0.65Ca0.35MnO3 nanoparticles. Raman spectra show that Jahn-Teller distortion has been decreased due to the presence of Ca and Pr in A-site. Magnetic measurements provide a Curie temperature around 200 K and saturation magnetization (MS) of about 3.43μB/Mn at 5 K. X-ray photoemission spectroscopy study suggests that Mn exists in a dual oxidation state (Mn(3+) and Mn(4+)). Resistivity measurements suggest that charge-ordered states of Mn(3+) and Mn(4+), which might be influenced by the presence of Pr, have enhanced insulating behavior in (La0.6Pr0.4)0.65Ca0.35MnO3. Band gap estimated from UV-Vis spectroscopy measurements comes in the range of wide band gap semiconductors (∼3.5 eV); this makes (La0.6Pr0.4)0.65Ca0.35MnO3 a potential candidate for device application.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry for the rapid identification of yeasts causing bloodstream infections

Few studies have systematically standardised and evaluated matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for identification of yeasts from bloodstream infections. This is rapidly becoming pertinent for early identification of yeasts and appropriate antifungal therapy. We used 354 yeast strains identified by polymerase chain reaction (PCR) sequencing for standardisation and 367 blind clinical strains for validation of our MALDI-TOF MS protocols. We also evaluated different sample preparation methods and found the on-plate formic acid extraction method as most cost- and time-efficient. The MALDI-TOF assay correctly identified 98.9% of PCR-sequenced yeasts. Novel main spectrum projections (MSP) were developed for Candida auris, C. viswanathii and Kodamaea ohmeri, which were missing from the Bruker MALDI-TOF MS database. Spectral cut-offs computed by receiver operating characteristics (ROC) analysis showed 99.4% to 100% accuracy at a log score of ≥ 1.70 for C. tropicalis, C. parapsilosis, C. pelliculosa, C. orthopsilosis, C. albicans, C. rugosa, C. guilliermondii, C. lipolytica, C. metapsilosis, C. nivariensis. The differences in the species-specific scores of our standardisation and blind validation strains were not statistically significant, implying the optimal performance of our test protocol. The MSPs of the three new species also were validated. We conclude that MALDI-TOF MS is a rapid, accurate and reliable tool for identification of bloodstream yeasts. With proper standardisation, validation and regular database expansion, its efficiency can be further enhanced.

Fe-S cluster biogenesis in isolated mammalian mitochondria: coordinated use of persulfide sulfur and iron and requirements for GTP, NADH, and ATP

Iron-sulfur (Fe-S) clusters are essential cofactors, and mitochondria contain several Fe-S proteins, including the [4Fe-4S] protein aconitase and the [2Fe-2S] protein ferredoxin. Fe-S cluster assembly of these proteins occurs within mitochondria. Although considerable data exist for yeast mitochondria, this biosynthetic process has never been directly demonstrated in mammalian mitochondria. Using [(35)S]cysteine as the source of sulfur, here we show that mitochondria isolated from Cath.A-derived cells, a murine neuronal cell line, can synthesize and insert new Fe-(35)S clusters into aconitase and ferredoxins. The process requires GTP, NADH, ATP, and iron, and hydrolysis of both GTP and ATP is necessary. Importantly, we have identified the (35)S-labeled persulfide on the NFS1 cysteine desulfurase as a genuine intermediate en route to Fe-S cluster synthesis. In physiological settings, the persulfide sulfur is released from NFS1 and transferred to a scaffold protein, where it combines with iron to form an Fe-S cluster intermediate. We found that the release of persulfide sulfur from NFS1 requires iron, showing that the use of iron and sulfur for the synthesis of Fe-S cluster intermediates is a highly coordinated process. The release of persulfide sulfur also requires GTP and NADH, probably mediated by a GTPase and a reductase, respectively. ATP, a cofactor for a multifunctional Hsp70 chaperone, is not required at this step. The experimental system described here may help to define the biochemical basis of diseases that are associated with impaired Fe-S cluster biogenesis in mitochondria, such as Friedreich ataxia.

Spinigerin induces apoptotic like cell death in a caspase independent manner in Leishmania donovani

Antimicrobial peptides (AMPs) are multifunctional components of the innate immune system. Chemotherapeutic agents used for treatment of visceral leishmaniasis (VL) are now threatened due to the emergence of acquired drug resistance and toxicity. AMPs are attractive alternative to conventional pharmaceuticals. In this study, first time we explored the antileishmanial activity of spinigerin originally derived from Pseudacanthotermes spiniger. Leishmania donovani promastigotes present apoptosis-like cell death upon exposure to spinigerin (IC50, 150 μM). The infection rate was reduced by 20% upon exposure to 150 μM spinigerin but no cytotoxicity on host macrophages was observed. Elevation of intracellular ROS level and down-regulation of two ROS detoxifying enzymes, ascorbate peroxidase (APx) and trypanothione reductase (TR) suggested essential role of ROS machinery during spinigerin mediated cell death. About 97% cell population was found to be Annexin-V positive; 44% cells being highly Annexin-V positive. Moreover, we observed morphological changes like cell rounding, nuclear condensation, oligonucleosomal DNA degradation and TUNEL positive cells without loss of membrane integrity upon spinigerin exposure, suggests apoptosis-like death. Interestingly, collapse in mitochondrial membrane potential and increased level of intracellular ROS and calcium were not associated with caspase like activity. Computational analysis suggests spiningerin interacts with trypanothione reductase and thus probably interferes its function to detoxify the toxic ROS level. Therefore, spinigerin induces apoptosis-like cell death in L. donovani in a caspase-independent manner. The study elucidates the antileishmanial property of spinigerin that may be considered for future chemotherapeutic option alone or adjunct with other drug regimens for improved treatment of visceral leishmaniasis.

Determination of anthelmintic activity of the leaf and bark extract of tamarindus indica linn

The aim of the present study was to evaluate the anthelmintic activity of ethanolic and aqueous extract of leaves and bark of Tamarindus indica Linn using Pheretima posthuma and Tubifex tubifex as test worms. The time of paralysis and time of death were studied and the activity was compared with piperazine citrate as reference standard. The alcohol and aqueous extract of bark of Tamarindus indica exhibited significant anthelmintic activity as evidenced by decreased paralyzing time and death time. The results thus support the use of Tamarindus indica as an anthelmintic agent.