Visfatin/Nampt, vaspin, and retinol binding protein-4 (RBP-4) play an important role in insulin resistance. The objectives of this study were to measure visfatin/Nampt, vaspin, and RBP-4 concentrations in blood, liver, muscle, subcutaneous, omental, and mesenteric adipose tissues in morbidly obese subjects and investigate their relationship to insulin resistance. Blood and tissue samples were collected from 38 morbidly obese subjects during Roux-en-Y surgery. Insulin resistance biomarkers were measured using standard kits. Visfatin/Nampt, vaspin, and RBP-4 gene expression levels in tissues were measured using real-time PCR. Their protein concentrations in blood and tissues were measured using ELISA kits. Diabetic subjects had significantly higher homeostasis model of assessment-insulin resistance and age and lower blood HDL-cholesterol concentrations than nondiabetic and prediabetic subjects. Diabetic and prediabetic subjects had significantly higher blood concentrations of visfatin/Nampt and vaspin than nondiabetic subjects. Liver RBP-4 concentrations were positively associated with blood glucose concentrations. Blood insulin resistance biomarker levels were positively associated with visfatin/Nampt concentrations in omental adipose tissue and liver, and vaspin concentrations in mesenteric adipose tissue. In conclusion, the correlations of visfatin/Nampt, vaspin, and RBP-4 with insulin resistance are tissue dependent.

Abstract. Background: Vitamin D insufficiency is common before and after bariatric surgery. Optimal supplementation to treat vitamin D insufficiency is not clearly defined. Objective: Determine if serum 25 (OH) D levels improve by the consumption of an additional monthly ergocalciferol supplement by subjects after bariatric surgery. Study design: Thirty-two subjects were randomly divided to receive an additional 100,000 IUs of ergocalciferol monthly after bariatric surgery (n=10) or standard level vitamin D supplement after bariatric surgery (n=22). Serum 25 (OH) D, calcium, and hemoglobin A1c levels were measured preoperatively and one year after bariatric surgery. Results: Mean changes in BMI at 1-year post-operation was −18.12±6.46 kg/m2 in the control group versus −18.84±4.7 kg/m2; p=0.638 in the vitamin D group. One year after bariatric surgery, the mean changes from baseline in vitamin D levels were 2.69±9.4 and 12.4±17.0 ng/mL in control and intervention groups, respectively. The treated group showed a marginally higher mean increase in Vitamin D than the control group, p=0.059. Other mean changes at 1-year post-surgery that were not significantly different include calcium −0.264±0.45 and −0.21±0.509 mg/dl in control and intervention groups, respectively and Hgb A1c −1.0±1.21 and −0.95±0.071% in control and intervention groups, respectively. Conclusion: This study showed 100,000 IUs ergocalciferol once a month is a safe and effective treatment for vitamin D insufficiency in most patients having bariatric surgery.

Antiarrhythmic agents alter cardiac conduction, refractoriness, and action potential duration in a rate dependent fashion. A simple in vivo model was developed to measure these variables over a wide range of cycle lengths. Complete heart block was produced in dogs using an 8 French hexapolar ablation catheter, anterior skin electrode, and radiofrequency current (30 W, 13.6 +/- 2.6 seconds). Ventricular pacing and monophasic action potential recordings were performed using a single combination catheter. QRS and action potential durations were measured at multiple cycle lengths and after an abrupt change in paced cycle length. Ventricular effective refractory periods were also measured at multiple cycle lengths. Data obtained during flecainide and d-Sotalol infusions are presented. This simple model allows detailed in vivo evaluation of the electrophysiological effects of antiarrhythmic agents and combinations.

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