The endothelial microparticle response to a high fat meal is not attenuated by prior exercise

Triglyceride-rich postprandial lipoproteins are known to activate endothelial cells in vitro, contributing to atherosclerosis. Endothelial microparticles (EMP) are membranous vesicles released into the circulation from vascular endothelial cells that permit cell activation to be monitored in vivo. The objective of the study was to examine changes in EMP following a high fat meal, consumed with and without prior exercise. Eight recreationally active young men underwent two oral fat tolerance tests following either 100 min exercise at 70% VO₂peak (EX trial) or no exercise (CON trial) on the previous evening. Postprandial triglycerides were reduced (1.97 ± 0.31 vs. 1.17 ± 0.13 mmol L⁻¹, p < 0.05) and HDL-cholesterol (HDL-C) increased (1.20 ± 0.07 vs. 1.30 ± 0.08 mmol L⁻¹, p < 0.05) in the EX compared to CON trial. EMP (CD31+/42b−) increased postprandially (p < 0.05). However, counts were not different between trials (postprandial CON and EX trial counts × 10³ μL⁻¹, 3.10 ± 0.14 vs. 3.26 ± 0.37). There were no changes in sICAM-1 or sVCAM-1 postprandially and no differences between trials. Interleukin-6 (IL-6) and leukocytes increased postprandially (p < 0.05). IL-6 values were not different between trials. Leukocytes were higher at 0 h in the EX trial with CON and EX trial values similar at 6 h. EMP, but not sICAM-1 or sVCAM-1, increase in response to a high fat meal. However, EMP are not attenuated by acute exercise, despite a considerable reduction in postprandial lipemia and an increase in HDL-C. M. Harrison and R. P. Murphy contributed equally to this work.     

Exploring age-related decline on the Wisconsin Card Sorting Test

It is well established that performance on the Wisconsin Card Sorting Test (WCST) tends to decline with advanced age, but the reason for this decline has not been established. The objective of the present study was to clarify this question using a qualitative approach to the task. The WCST was administered to 19 older adults and 25 younger participants. In addition to standard testing procedures, all participants were asked to verbalize their response strategy when placing each card. Results of this procedure implicate poor set shifting and set maintenance, consistent with reduced efficiency of feedback utilization, as the primary cause for age-related decline on the WCST.     

Protective effects of voluntary exercise during the postinitiation phase of pancreatic carcinogenesis in the rat

Studies were undertaken to evaluate the effects of exercise on the development of pancreatic cancer. Exercise is one life-style factor that has received little attention with regard to its role in the etiology of cancer. Male Lewis and female F344 rats were initiated with azaserine during the suckling period and weaned to the experimental protocols. Food and water were available ad libitum. A purified diet of 20% unsaturated fat was fed to both the sedentary and exercise groups. Rats of the exercise group had free access to voluntary exercise wheels. At approximately 2 and 4 months postinitiation, pancreases were evaluated for the number and size of azaserine-induced putative preneoplastic foci by quantitative stereology. Voluntary exercise activity peaked at approximately 2 months postinitiation with a gradual decline in activity there-after. Male Lewis rats averaged 0.95 +/- 0.13 km/day (SE) and female F344 rats averaged 2.73 +/- 0.26 km/day of voluntary wheel running. Compared with the sedentary groups, male Lewis and female F344 rats with access to the running wheels had significantly smaller foci at 4 months postinitiation. Azaserine-induced foci were evaluated in the male Lewis rats at both 2 and 4 months postinitiation. At 4 months postinitiation, the size and growth rate (as measured by [3H]thymidine autoradiography) of foci were less in the rats with access to the exercise wheels. No differences were observed at 2 months postinitiation. Access to voluntary exercise reduced the growth rate of azaserine-induced pancreatic foci. The effect occurred late in the postinitiation phase and was not directly related to the extent of running activity early in the postinitiation phase.     

To activate or not to activate: distinct strategies used by Helicobacter pylori and Francisella tularensis to modulate the NADPH oxidase and survive in human neutrophils

Summary:  Neutrophils accumulate rapidly at sites of infection, and the ability of these cells to phagocytose and kill microorganisms is an essential component of the innate immune response. Relatively few microbial pathogens are able to evade neutrophil killing. Herein, we describe the novel strategies used by Helicobacter pylori and Francisella tularensis to disrupt neutrophil function, with a focus on assembly and activation of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase.     

The effect of tissue expansion on previously irradiated skin.

Opinion remains divided over the advisability of tissue expansion in previously irradiated skin. We examined the properties of, and complications associated with, tissue expansion in previously irradiated rabbit scalps. Irradiation injury was produced using fractionated roentgen rays, with a total dose of 5000 cGy over a 5-week interval. Following a 20-week convalescence interval, expansion was incrementally conducted over 4 weeks. Monitored parameters included cutaneous perfusion as indicated by fiberoptic dermofluorometry, intraluminal pressure, linear surface gain, and area of surface necrosis. The incidence and severity of complications, including surface necrosis, were significantly higher among irradiated animals. Furthermore, the overlying skin of irradiated animals demonstrated a significantly decreased compliance and measurable area gain. Given the inferior expansibility and higher tendency toward complications with contemporary expansion techniques in previously irradiated skin, alternate reconstructive options are preferable in this setting.