Seven-day overfeeding enhances adipose tissue dietary fatty acid storage and decreases myocardial and skeletal muscle dietary fatty acid partitioning in healthy subjects.

Increased myocardial partitioning of dietary fatty acids (DFA) and decreased left ventricular (LV) function is associated with insulin resistance in prediabetes. We hypothesized that enhanced myocardial DFA partitioning and reduced LV function might be induced concomitantly with reduced insulin sensitivity upon a 7-day hypercaloric (+50% in caloric intake), high-saturated fat (~11%energy), and simple carbohydrates (~54%energy) diet (HIGHCAL) versus an isocaloric diet (ISOCAL) with a moderate amount of saturated fat (~8%energy) and carbohydrates (~50%energy). Thirteen healthy subjects (7 men/6 women) underwent HIGHCAL versus ISOCAL in a randomized crossover design, with organ-specific DFA partitioning and LV function measured using the oral 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid and [11C]acetate positron emission tomography methods at the end of both interventions. HIGHCAL induced a decrease in insulin sensitivity indexes with no significant change in body composition. HIGHCAL led to increased subcutaneous abdominal (+4.2 ± 1.6%, P < 0.04) and thigh (+2.4 ± 1.2%, P < 0.08) adipose tissue storage and reduced cardiac (-0.31 ± 0.11 mean standard uptake value [(SUV), P < 0.03] and skeletal muscle (-0.17 ± 0.08 SUV, P < 0.05) DFA partitioning without change in LV function. We conclude that early increase in adipose tissue DFA storage protects the heart and skeletal muscles from potential deleterious effects of DFA.

Performance characteristics of a straight versus bent 25-gauge vitrector.

BACKGROUND AND OBJECTIVE: During vitrectomy in phakic patients, lens damage can occur while shaving the peripheral vitreous. Modifying the vitrector with a slight bend can diminish this risk. MATERIALS AND METHODS: To assess whether the bent vitrector performs to standard, the cutting and aspiration functionality of a straight and bent cutter was tested on both the vitreous from an enucleated porcine eye and balanced salt solution. Data were analyzed using a paired two-tailed t-test for comparison of two small sample means. RESULTS: The average time for removal of vitreous was 19.32 seconds with the straight cutter and 19.26 seconds for the bent cutter. There was no statistically significant difference between the removal rates (P = .87). The average time for aspiration of balanced salt solution was 14.3 seconds with the straight tip and 14.16 seconds with the bent tip. There was no statistically significant difference between the aspiration rates (P = .55). CONCLUSION: Both unmodified and bent vitrectors demonstrate an equally efficient rate of removal of vitreous and balanced salt solution in vitro.