Effect of Exercise Training on Microvascular Function in African American and Caucasian Women

African Americans (AA), especially women, exhibit long-standing disparities in cardiovascular disease (CVD) and obesity. The prevalence of endothelial dysfunction, directly linked to hypertension, is considerably greater in AA than Caucasians (C). Vascular smooth muscle function (mediating endothelium-independent vasodilation) is also related to CVD risk factors but is underappreciated because most literature in C suggest endothelium-independent vasodilatory response is resistance to change with disease (hypertension) or exercise training. Furthermore, the regulation of local skeletal muscle blood flow (an important site of peripheral resistance) has not been sufficiently assessed. Microdialysis is the only method that allows monitoring of microvascular blood flow while affecting the local tissue with pharmacological agents in the absence of systemic, or organ level, effects in humans. Microvascular blood flow was assessed by microdialysis in vivo in skeletal muscle before and after 12 weeks of aerobic exercise training in young, obese AA and C women. Our preliminary data suggested that microvascular endothelial function, assessed by percent change in blood flow from basal (Δ Blood Flow) in response to acetylcholine perfusion was improved in both obese AA (n=5) and obese C (n=4) women. Microvascular endothelium-independent blood flow, assessed by percent change in blood flow from baseline (Δ Blood Flow) upon addition of sodium nitroprusside to the perfusate, was improved in AA (n=3) but not in C (n=9) women. Exercise training may improve endothelium-dependent vascular function in both AA and C, but improve endothelium-independent vascular function only in AA. Results of this study have potential to inform preventive interventions including lifestyle and pharmacological approaches designed to reduce disparities in hypertension and end-organ damage

Electrocatalyst Design for Direct Borohydride Oxidation Guided by First Principles

© 2017 American Chemical Society. Density functional theory (DFT) calculations are used to propose a Au-Cu binary metal catalyst for the electrochemical borohydride oxidation reaction (BOR), which is evaluated experimentally and observed to show enhanced oxidation activity relative to a pure Au electrode. Our previous work has applied DFT methods to determine the BOR mechanism and elucidate the key reaction steps that dictate catalyst activity and selectivity to complete oxidation. A balanced initial adsorption strength of the borohydride anion is essential for an active and selective catalyst. Adsorption must be strong enough to provide a reasonable coverage of surface species and promote B-H bond dissociation but not so strong as to promote easy dissociation and provide a high coverage of surface H atoms that result in H 2 evolution. Borohydride adsorption energetics were evaluated for a series of close-packed pure metal surfaces. Copper catalysts appear encouraging but are not electrochemically stable under reaction conditions. Gold-copper alloys are predicted to show increased activity compared to a pure gold electrode while maintaining the selectivity to direct oxidation and increasing the stability compared to pure Cu. DFT results suggest an approximately 0.2 V decrease in the overpotential for borohydride oxidation on a Au 2 Cu(111) electrode compared to that on a Au(111) electrode. This DFT-predicted reduction in overpotential is realized experimentally. Electrodeposition was used to prepare AuCu electrodes, and their borohydride oxidation electrokinetics were examined by linear sweep voltammetry. An 88.5% gold and 11.5% copper sample demonstrated an overpotential reduction of 0.17 V compared to a pure Au electrode. The binding energy and adsorption free energy of BH 4- over other surface alloys are also examined to further identify promising BOR electrodes. (Chemical Equation Presented)

Acute Modulation of Adipose Tissue Lipolysis by Intravenous Estrogens

Objective: The aim of this study was to determine whether intravenous (IV) conjugated estrogens (EST) acutely enhance the suppression of whole-body or regional subcutaneous adipose tissue (SAT) lipolysis by insulin in postmenopausal women. Research Methods and Procedures: We assessed whole-body lipolysis by [2H5]glycerol rate of appearance (GlycRA) and abdominal and femoral SAT lipolysis (interstitial glycerol; GlycIS) by subcutaneous microdialysis. Postmenopausal women (n = 12) were studied on two occasions, with IV EST or saline control (CON), under basal conditions and during a 3-stage (4, 8, and 40 mU/m2/ min) hyperinsulinemic, euglycemic clamp. Ethanol outflow/inflow ratio and recovery of [13C] glycerol during microdialysis were used to assess blood flow changes and interstitial glycerol concentrations, respectively. Results: Compared with CON, EST did not affect systemic basal or insulin-mediated suppression of lipolysis (GlycRA) or SAT nutritive blood flow. Basal GlycIS in SAT was reduced on the EST day. However, insulin-mediated suppression of lipolysis in SAT was not significantly influenced by EST. Discussion: These findings suggest that estrogens acutely reduce basal lipolysis in SAT through an unknown mechanism but do not alter whole-body or SAT suppression of lipolysis by insulin. Originally published Obesity (Silver Spring), Vol. 14, No. 12, Dec 200

The Short-Term Effect of Prunes in Improving Bone in Men

Osteoporosis is a major health concern in aging populations, where 54% of the U.S. population aged 50 and older have low bone mineral density (BMD). Increases in inflammation and oxidative stress play a major role in the development of osteoporosis. Men are at a greater risk of mortality due to osteoporosis-related fractures. Our earlier findings in rodent male and female models of osteoporosis, as well as postmenopausal women strongly suggest the efficacy of prunes (dried plum) in reducing inflammation and preventing/reversing bone loss. The objective of this study was to examine the effects of two doses of prunes, daily, on biomarkers of inflammation and bone metabolism in men with some degree of bone loss (BMD; t-score between −0.1 and −2.5 SD), for three months. Thirty-five men between the ages of 55 and 80 years were randomized into one of three groups: 100 g prunes, 50 g prunes, or control. Consumption of 100 g prunes led to a significant decrease in serum osteocalcin (p < 0.001). Consumption of 50 g prunes led to significant decreases in serum osteoprotegerin (OPG) (p = 0.003) and serum osteocalcin (p = 0.040), and an increase in the OPG:RANKL ratio (p = 0.041). Regular consumption of either 100 g or 50 g prunes for three months may positively affect bone turnover

Systemic Racism and Health Disparities: A Statement from Editors of Family Medicine Journals

The year 2020 has been marked by historic protests across the United States and the globe sparked by the deaths of George Floyd, Ahmaud Arbery, Breonna Taylor, and so many other Black people. The protests heightened awareness of racism as a public health crisis and triggered an antiracism movement. The editors of several North American family medicine publications have come together to address this call to action and share resources on racism across our readerships.http://deepblue.lib.umich.edu/bitstream/2027.42/163331/1/Final Statement on Systemic Racism- with acknowledgements.pdf-1Description of Final Statement on Systemic Racism- with acknowledgements.pdf : Main ArticleSEL

Review of microdialysis in brain tumors, from concept to application: First Annual Carolyn Frye-Halloran Symposium

In individuals with brain tumors, pharmacodynamic and pharmacokinetic studies of therapeutic agents have historically used analyses of drug concentrations in serum or cerebrospinal fluid, which unfortunately do not necessarily reflect concentrations within the tumor and adjacent brain. This review article introduces to neurological and medical oncologists, as well as pharmacologists, the application of microdialysis in monitoring drug metabolism and delivery within the fluid of the interstitial space of brain tumor and its surroundings. Microdialysis samples soluble molecules from the extracellular fluid via a semipermeable membrane at the tip of a probe. In the past decade, it has been used predominantly in neurointensive care in the setting of brain trauma, vasospasm, epilepsy, and intracerebral hemorrhage. At the first Carolyn Frye-Halloran Symposium held at Massachusetts General Hospital in March 2002, the concept of microdialysis was extended to specifically address its possible use in treating brain tumor patients. In doing so we provide a rationale for the use of this technology by a National Cancer Institute consortium, New Approaches to Brain Tumor Therapy, to measure levels of drugs in brain tissue as part of phase 1 trials. Originally published Neuro-oncology, Vol. 6, No. 1, Jan 200

The influence of the level of physical activity and human development in the quality of life in survivors of stroke

<p>Abstract</p> <p>Background</p> <p>The association between physical activity and quality of life in stroke survivors has not been analyzed within a framework related to the human development index. This study aimed to identify differences in physical activity level and in the quality of life of stroke survivors in two cities differing in economic aspects of the human development index.</p> <p>Methods</p> <p>Two groups of subjects who had suffered a stroke at least a year prior to testing and showed hemiplegia or hemiparesis were studied: a group from Belo Horizonte (BH) with 48 people (51.5 ± 8.7 years) and one from Montes Claros (MC) with 29 subjects (55.4 ± 8.1 years). Subsequently, regardless of location, the groups were divided into Active and Insufficiently Active so their difference in terms of quality of life could be analyzed.</p> <p>Results</p> <p>There were no significant differences between BH and MCG when it came to four dimensions of physical health that were evaluated (physical functioning, physical aspect, pain and health status) or in the following four dimensions of mental health status (vitality, social aspect, emotional aspect and mental health). However, significantly higher mean values were found in Active when compared with Insufficiently Active individuals in various measures of physical health (physical functioning 56.2 ± 4.4 vs. 47.4 ± 6.9; physical aspect 66.5 ± 6.5 vs. 59.1 ± 6.7; pain 55.9 ± 6.2 vs. 47.7 ± 6.0; health status 67.2 ± 4.2 vs. 56.6 ± 7.8) (arbitrary units), and mental health (vitality 60.9 ± 6.8 vs. 54.1 ± 7.2; social aspect 60.4 ± 7.1 vs. 54.2 ± 7.4; emotional aspect 64.0 ± 5.5 vs. 58.1 ± 6.9; mental health status 66.2 ± 5.5 vs. 58.4 ± 7.5) (arbitrary units).</p> <p>Conclusions</p> <p>Despite the difference between the cities concerning HDI values, no significant differences in quality of life were found between BH and MCG. However, the Active group showed significantly better results, confirming the importance of active lifestyle to enhance quality of life in stroke survivors.</p

Antimicrobial-Drug Prescription in Ambulatory Care Settings, United States, 1992–2000

During the 1990s, as antimicrobial resistance increased among pneumococci, many organizations promoted appropriate antimicrobial use to combat resistance. We analyzed data from the National Ambulatory Medical Care Survey, an annual sample survey of visits to office-based physicians, and the National Hospital Ambulatory Medical Care Survey, an annual sample survey of visits to hospital emergency and outpatient departments, to describe trends in antimicrobial prescribing from 1992 to 2000 in the United States. Approximately 1,100–1,900 physicians reported data from 21,000–37,000 visits; 200–300 outpatient departments reported data for 28,000–35,000 visits; ~400 emergency departments reported data for 21,000–36,000 visits each year. In that period, the population- and visit-based antimicrobial prescribing rates in ambulatory care settings decreased by 23% and 25%, respectively, driven largely by a decrease in prescribing by office-based physicians. Antimicrobial prescribing rates changed as follows: amoxicillin and ampicillin, –43%; cephalosporins, –28%; erythromycin, –76%; azithromycin and clarithromycin, +388%; quinolones, +78%; and amoxicillin/clavulanate, +72%. This increasing use of azithromycin, clarithromycin, and quinolones warrants concern as macrolide- and fluoroquinolone-resistant pneumococci are increasing

Effect of 28 days of creatine ingestion on muscle metabolism and performance of a simulated cycling road race

<p>Abstract</p> <p>Purpose</p> <p>The effects of creatine supplementation on muscle metabolism and exercise performance during a simulated endurance road race was investigated.</p> <p>Methods</p> <p>Twelve adult male (27.3 ± 1.0 yr, 178.6 ± 1.4 cm, 78.0 ± 2.5 kg, 8.9 ± 1.1 %fat) endurance-trained (53.3 ± 2.0 ml* kg^-1* min^-1, cycling ~160 km/wk) cyclists completed a simulated road race on a cycle ergometer (Lode), consisting of a two-hour cycling bout at 60% of peak aerobic capacity (VO_2peak) with three 10-second sprints performed at 110% VO_{2 peak}every 15 minutes. Cyclists completed the 2-hr cycling bout before and after dietary creatine monohydrate or placebo supplementation (3 g/day for 28 days). Muscle biopsies were taken at rest and five minutes before the end of the two-hour ride.</p> <p>Results</p> <p>There was a 24.5 ± 10.0% increase in resting muscle total creatine and 38.4 ± 23.9% increase in muscle creatine phosphate in the creatine group (<it>P </it>< 0.05). Plasma glucose, blood lactate, and respiratory exchange ratio during the 2-hour ride, as well as VO_{2 peak}, were not affected by creatine supplementation. Submaximal oxygen consumption near the end of the two-hour ride was decreased by approximately 10% by creatine supplementation (P < 0.05). Changes in plasma volume from pre- to post-supplementation were significantly greater in the creatine group (⁺14.0 ± 6.3%) than the placebo group (^-10.4 ± 4.4%; <it>P </it>< 0.05) at 90 minutes of exercise. The time of the final sprint to exhaustion at the end of the 2-hour cycling bout was not affected by creatine supplementation (creatine pre, 64.4 ± 13.5s; creatine post, 88.8 ± 24.6s; placebo pre, 69.0 ± 24.8s; placebo post 92.8 ± 31.2s: creatine vs. placebo not significant). Power output for the final sprint was increased by ~33% in both groups (creatine vs. placebo not significant).</p> <p>Conclusions</p> <p>It can be concluded that although creatine supplementation may increase resting muscle total creatine, muscle creatine phosphate, and plasma volume, and may lead to a reduction in oxygen consumption during submaximal exercise, creatine supplementation does not improve sprint performance at the end of endurance cycling exercise.</p