Defects in Mitochondrial Efficiency and H2O2 Emissions in Obese Women Are Restored to a Lean Phenotype With Aerobic Exercise Training

The notion that mitochondria contribute to obesity-induced insulin resistance is highly debated. Therefore, we determined whether obese (BMI 33 kg/m²), insulin-resistant women with polycystic ovary syndrome had aberrant skeletal muscle mitochondrial physiology compared with lean, insulin-sensitive women (BMI 23 kg/m²). Maximal whole-body and mitochondrial oxygen consumption were not different between obese and lean women. However, obese women exhibited lower mitochondrial coupling and phosphorylation efficiency and elevated mitochondrial H₂O₂ (mtH₂O₂) emissions compared with lean women. We further evaluated the impact of 12 weeks of aerobic exercise on obesity-related impairments in insulin sensitivity and mitochondrial energetics in the fasted state and after a high-fat mixed meal. Exercise training reversed obesity-related mitochondrial derangements as evidenced by enhanced mitochondrial bioenergetics efficiency and decreased mtH₂O₂ production. A concomitant increase in catalase antioxidant activity and decreased DNA oxidative damage indicate improved cellular redox status and a potential mechanism contributing to improved insulin sensitivity. mtH₂O₂ emissions were refractory to a high-fat meal at baseline, but after exercise, mtH₂O₂ emissions increased after the meal, which resembles previous findings in lean individuals. We demonstrate that obese women exhibit impaired mitochondrial bioenergetics in the form of decreased efficiency and impaired mtH₂O₂ emissions, while exercise effectively restores mitochondrial physiology toward that of lean, insulin-sensitive individuals.     

A Team-Based Approach to Introduce and Sustain the Use of the WHO Surgical Safety Checklist in Tanzania

Introduction

Millions of patients worldwide suffer disability and death due to complications related to surgery. Many of these complications can be reduced by the use of the World Health Organization (WHO) Surgical Safety Checklist (SSC), a simple tool that can enhance teamwork and communication and improve patient safety. Despite the evidence on benefits of its use, introducing and sustaining the use of the checklist are challenging. We present a team-based approach employed in a low-resource setting in Tanzania, which resulted in high checklist utilization and compliance rates.

Methods

We reviewed reported data from facility registers supplemented by direct observation data by mentors to evaluate the use of the WHO SSC across 40 health facilities in two regions of Tanzania between January and December 2018. We analyzed the self-reported monthly data on total number of major surgeries performed and proportion of surgeries where the checklist was used. We also analyzed the use of the SSC during direct observation by external mentors and completion rates of the SSC in a random selection of patient files during two mentorship visits between June and December 2018.

Results

During the review period, the average self-reported checklist utilization rate was 79.3% (11,564 out of 14,580 major surgeries). SSC utilization increased from 0% at baseline in January 2018 to 98% in December 2018. The proportion of checklists that were completely and correctly filled out increased between the two mentor visits from 82.1 to 92.8%, but the gain was significantly greater at health centers than at hospitals (p < 0.05). Health centers (which had one or two surgical teams) self-reported a higher checklist utilization rate than hospitals (which had multiple surgical teams), i.e., 99.4% vs 68.8% (p < 0.05).

Conclusion and recommendations

Our findings suggest that Surgical Safety Checklist implementation is feasible even in lower-resource settings. The self-reported SSC utilization rate is higher than reported in other similar settings. We attribute this finding to the team-based approach employed and the ongoing regular mentorship. We recommend use of this approach to scale-up checklist use in other regions in the country as recommended in the Ministry of Health of Tanzania’s National Surgical, Obstetric, and Anesthesia Plan (NSOAP).

     

Three-dimensional transesophageal echocardiographic demonstration of anatomical defects in AV septal defect patients presenting for reoperation

We present two- and three-dimensional transesophageal echocardiographic findings of two adult patients who presented for reoperation after previous repair of a partial atrioventricular (AV) septal defect. Both patients had a cleft in the left AV valve with severe regurgitation. One patient had an additional 10 x 5 mm defect connecting the left ventricle to the right atrium through the AV junction. Three-dimensional echocardiography was superior to two-dimensional echocardiography in comprehensively delineating the anatomical defects in the left AV valve and the AV junction.