Validation of the BioPRYN enzyme-linked immunosorbent assay for detection of pregnancy-specific protein-B (PSPB) and diagnosis of pregnancy in American bison (Bison bison).

This study assessed the accuracy of the commercial BioPRYN® ELISA for the detection of pregnancy-specific protein-B (PSPB) using a single blood sample to determine pregnancy status in American bison (Bison bison). A total of 49 bison cows were used in the study, and sampled at two time-points during the gestation period, fall and spring, correlating with early- to mid-term gestation (average 62.9 days post-mating) and mid- to late-term gestation (average 229.2 days post-mating), respectively. Sensitivity of the test during early- to mid-term gestation sampling period (fall) was 87.1%, while specificity was 100%; sensitivity of the test during late-term gestation sampling period (spring) was 96.3%, while specificity remained at 100%. In total, the test showed a total sensitivity of 91.4%, specificity of 100% and total accuracy of 93.8%, similar to domestic cattle. Use of the single-sample BioPRYN® ELISA in American Bison for pregnancy diagnosis is economical and practical, minimizing animal handling time, frequency and subsequent stress while providing accurate results for pregnancy diagnosis at 62 days post-mating. This method should be considered over more traditional pregnancy diagnosis methods for use in managed bison herds.

Effects of an 8-week weight-loss program on cardiovascular disease risk factors and regional body composition.

OBJECTIVE: To determine the influence of weight loss on multiple cardiovascular disease (CVD) risk factors. DESIGN: Overweight women (n = 12; mean 44.2% fat) and men (n = 10; mean 30.7% fat) participated in an 8 week weight-loss program that included dietary, exercise, multi-vitamin/mineral supplementation, and behavior modification components. Measurement of total and regional body composition assessed using dual energy X-ray absorptiometry (DEXA), circumferences and blood sampling for total cholesterol, LDL cholesterol, HDL cholesterol, triacylglycerols, homocysteine, insulin and leptin were performed before and after the weight loss intervention. RESULTS: Subjects increased their physical activity and decreased their energy intake, resulting in a mean decrease in body mass of - 4.3 +/- 3.4 kg in women and -4.7 +/- 3.1 kg in men. Fat accounted for 88 and 58% of the decrease in body mass in men and women, respectively. Proportionally, men lost significantly more fat mass from the trunk region compared to women. Serum total and LDL cholesterol were significantly decreased in men (-11 and -14%, respectively) but not women (-3 and -3%, respectively) and there were no changes in HDL cholesterol and triacylglycerols. Serum leptin was significantly decreased (-36%) and highly correlated to fat mass (r= 0.839). There were no changes in serum insulin and plasma homocysteine. CONCLUSIONS: These data indicate that short-term weight loss resulting from reducing percentage energy from fat, increasing physical activity and vitamin/mineral supplements including folic acid has a favorable effect on regional body composition and total and LDL cholesterol with minimal effects on HDL cholesterol, triacylglycerols, homocysteine and insulin and the effects are greater in men compared to women. Supplementation with folic acid or emphasis on folic acid-rich foods may be an important component of a weight loss program to prevent increases in homocysteine.

Effects of a high-fat diet on postabsorptive and postprandial testosterone responses to a fat-rich meal.

Postprandial testosterone concentrations have been shown to significantly decrease after a fat-rich meal, which may be due to inhibition of testosterone production by chylomicrons. We examined the effects of a high-fat diet known to reduce postprandial chylomicrons on the testosterone response to a fat-rich meal. Total testosterone (TT), free testosterone (FT), cortisol, and insulin responses to a high-fat test meal containing 5.44 MJ (1,300 kcal, 11% carbohydrate, 3% protein, 86% fat) were determined before (week 0) and after (week 8) an 8-week high-fat diet (64% fat) in 11 healthy men. The high-fat diet resulted in significant reductions in postabsorptive and postprandial serum triacylglycerols (55% and 50%, respectively). There were no significant changes in postabsorptive serum TT, FT, and cortisol, but insulin concentrations were significantly (P < or = .05) lower at week 8 (-28%). There was a significant reduction 1 hour after the fat-rich meal for TT (-22%) and FT (-23%), which remained significantly below baseline for 8 hours. Postprandial TT and FT responses were not significantly different after the 8-week high-fat diet. Postprandial serum cortisol concentrations were significantly reduced 1 hour after the meal. There were no significant differences before and after the high-fat diet. Insulin was significantly increased at the 0-, 1-, and 2-hour postprandial time points before and after the high-fat diet. Compared with week 0, insulin concentrations were significantly lower prior to and immediately after the fat-rich meal at week 8. These data indicate a fat-rich meal results in a prolonged reduction in TT and FT concentrations that is not altered by lowering postprandial chylomicrons. Alternative mechanisms (eg, higher uptake at the receptor level of cells) other than chylomicron-induced or insulin-induced inhibition of steroidogenesis are likely responsible for the reduction in TT and FT after a fat-rich meal.