Determining the waist circumference in african americans which best predicts insulin resistance

Total body size and central fat distribution are important determinants of insulin resistance. The BMI and waist circumference (WC) thresholds in African Americans that best predict insulin resistance are unknown. Our goal was to determine the BMI and WC values in African Americans, which optimally predict insulin resistance. The subjects were African Americans (68 men, 63 women), aged 35 +/- 8 years (mean +/- s.d.), with a BMI of 30.9 +/- 7.5, in the range of 18.5-54.7 kg/m(2), and with a WC of 98 +/- 18, in the range of 69-173 cm. Insulin resistance was defined by the lowest tertile of the insulin sensitivity index (S(I)). The Youden index was calculated to determine the WC and BMI thresholds that predict insulin resistance with an optimal combination of sensitivity and specificity. In men the thresholds that optimally predicted insulin resistance were a BMI > or =30 kg/m(2) or a WC > or =102 cm. For women, insulin resistance was best predicted by a BMI > or =32 kg/m(2) or a WC > or =98 cm. In African Americans, insulin resistance (in men) was best predicted by a WC > or =102 cm, and in women by a WC > or =98 cm, or by a BMI value that fell in the obese category (men: > or =30 kg/m(2), women: > or =32 kg/m(2)).     

Insect-attracting and antimicrobial properties of antifreeze for monitoring insect pests and natural enemies in stored corn

Insect infestations in stored grain cause extensive damage worldwide. Storage insect pests, including the Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae); Sitophilus spp. (Coleoptera: Curculionidae); and their natural enemies [e.g., Cephalonomia tarsalis (Ashmead) (Hymenoptera: Bethylidae), and Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae)] inhabit a temporary, but stable ecosystem with constant environmental conditions. The objective of the present experiment was to assess the efficacy of using ethylene glycol antifreeze in combination with nutrient solutions to monitor storage insect pest and natural enemy populations in three bins of corn, Zea mays L. The treatments were deionized water, a diluted (1:5 antifreeze:water) antifreeze solution, 10% honey, 10% honey in the diluted antifreeze solution, 10% beer in the diluted antifreeze solution, 10% sucrose in the diluted antifreeze solution, and a commercial pheromone trap suspended in a 3.8-liter container filled with 300-ml of diluted antifreeze solution. The seven treatments captured storage insect pests and their natural enemies in the bins at 33-36 degrees C and 51-55% RH. The pheromone trap in the container with the diluted antifreeze captured significantly more P. interpunctella than the other treatments, but a lower percentage (7.6%) of these captures were females compared with the rest of the treatments (> 40% females). All trapping solutions also captured Sitophilus spp. and other beetle species, but the captures of the coleopteran pests were not significantly different among the seven treatments (P > 0.05). Two parasitoid wasps also were captured in the study. The number of A. calandrae was different among the seven treatments (P < 0.05), whereas the number of C. tarsalis was not different among the treatments (P > 0.05). Most A. calandrae adults were captured by the 10% honey in the diluted antifreeze, whereas the fewest were captured in the deionized water. Microbial growth was observed in the 10% honey solution, but no microbial growth occurred in the rest of the treatments, including 10% honey in the diluted antifreeze solution. The results of insect captures and microbial growth demonstrated that antifreeze could be used as a part of storage insect monitoring and/or control programs.     

Evaluation of quantitative models of the effect of insulin on lipolysis and glucose disposal

The effects of insulin on the suppression of lipolysis are neither fully understood nor quantified. We examined a variety of mathematical models analogous to the minimal model of glucose disposal (MMG) to quantify the combined influence of insulin on lipolysis and glucose disposal during an insulin-modified frequently sampled intravenous glucose tolerance test. The tested models, which include two previously published ones, consisted of separate compartments for plasma free fatty acids (FFA), glucose, and insulin. They differed in the number of compartments and in the action of insulin to suppress lipolysis that decreased the plasma FFA level. In one category of models, a single insulin compartment acted on both glucose and FFA simultaneously. In a second category, there were two insulin compartments, each acting on FFA and glucose independently. For each of these two categories, we tested 11 variations of how insulin suppressed lipolysis. We also tested a model with an additional glucose compartment that acted on FFA. These 23 models were fit to the plasma FFA and glucose concentrations of 102 subjects individually. Using Bayesian model comparison methods, we selected the model that best balanced fit and minimized model complexity. In the best model, insulin suppressed lipolysis via a Hill function through a remote compartment that acted on both glucose and FFA simultaneously, and glucose dynamics obeyed the classic MMG.     

Both Subcutaneous and Visceral Adipose Tissue Correlate Highly with Insulin Resistance in African Americans

Objective: The contribution of visceral adipose tissue (VAT) to insulin resistance is well‐established; however, the role of subcutaneous abdominal adipose tissue (SAT) in insulin resistance remains controversial. Sex may determine which of these two components of abdominal obesity is more strongly related to insulin resistance and its consequences. The aim of this study was to determine whether both VAT and SAT contribute to insulin resistance in African Americans and to examine the effects of sex on this relationship. Research Methods and Procedures: This was a cross‐sectional study of 78 nondiabetic African‐American volunteers (44 men, 35 women; age 33.8 ± 7.3 years; BMI 30.9 ± 7.4 kg/m²). VAT and SAT volumes were measured using serial computerized tomography slices from the dome of the diaphragm to the iliac crest. The insulin sensitivity index (S_I) was determined from the minimal model using data obtained from the frequently sampled intravenous glucose tolerance test. Results: In men, both VAT and SAT were negatively correlated with S_I (r for both correlations = ?0.57; p < 0.01). In women, the correlation coefficient between VAT and S_I was ?0.50 (p < 0.01) and between SAT and S_I was ?0.67 (p < 0.01). In women, the correlation coefficient for S_I with SAT was significantly greater than the correlation coefficient with VAT (p = 0.02). Discussion: Both SAT and VAT are strongly correlated with insulin resistance in African Americans. For African‐American women, SAT may have a greater effect than VAT on insulin resistance.     

Some observations on the mechanisms of blocking of nuclear staining by cisplatin

Summary The effect of cisplatin (cis-dichloro-diamminoplatinum II) treatment on staining of nuclei with various basic dyes and with the Feulgen reaction has been studied. Although cisplatin is reported to show negligible reaction with DNA phosphates, it has a substantial blocking effect on staining with most dyes. Short treatment with cisplatin results in binding mainly to guanine bases of DNA, causing partial blocking of the Feulgen reaction and almost complete blocking of ethidium intercalation; binding of neutral red and crystal violet is enhanced, apparently as a result of cisplatin-induced denaturation of DNA. Very prolonged cisplatin treatment does not completely block the Feulgen reaction, indicating that reaction of cisplatin with purine bases is not complete. Since attachment of cisplatin to DNA bases is unlikely to prevent binding of most basic dyes, it is suggested that the blocking of their staining may result from steric hindrance caused by formation of DNA-protein cross-links by cisplatin. Whatever the mechanism, it is incapable of producing complete blocking of staining with certain dyes. As a practical tool, it appears that rapid and almost complete blocking of staining by cisplatin may be used as an indicator of intercalative binding of dyes to DNA.     

Identification of endogenous acyl amino acids based on a targeted lipidomics approach

Using a partially purified bovine brain extract, our lab identified three novel endogenous acyl amino acids in mammalian tissues. The presence of numerous amino acids in the body and their ability to form amides with several saturated and unsaturated fatty acids indicated the potential existence of a large number of heretofore unidentified acyl amino acids. Reports of several additional acyl amino acids that activate G-protein coupled receptors (e.g., N-arachidonoyl glycine, N-arachidonoyl serine) and transient receptor potential channels (e.g., N-arachidonoyl dopamine, N-acyl taurines) suggested that some or many novel acyl amino acids could serve as signaling molecules. Here, we used a targeted lipidomics approach including specific enrichment steps, nano-LC/MS/MS, high-throughput screening of the datasets with a potent search algorithm based on fragment ion analysis, and quantification using the multiple reaction monitoring mode in Analyst software to measure the biological levels of acyl amino acids in rat brain. We successfully identified 50 novel endogenous acyl amino acids present at 0.2 to 69 pmol g⁻¹ wet rat brain.     

The Relationship between Reversed Masked Priming and the Tri-Phasic Pattern of the Lateralised Readiness Potential

One of the potential explanations for negative compatibility effects (NCE) in subliminal motor priming tasks has been perceptual prime-target interactions. Here, we investigate whether the characteristic tri-phasic LRP pattern associated with the NCE is caused by these prime-target interactions. We found that both the prime-related phase and the critical reversal phase remain present even on trials where the target is omitted, confirming they are elicited by the prime and mask, not by prime-target interactions. We also report that shape and size of the reversal phase are associated with response speed, consistent with a causal role for the reversal for the subsequent response latency. Additionally, we analysed sequential modulation of the NCE by previous conflicting events, even though such conflict is subliminal. In accordance with previous literature, this modulation is small but significant.