Increased muscle blood supply and transendothelial nutrient and insulin transport induced by food intake and exercise: effect of obesity and ageing.

This review concludes that a sedentary lifestyle, obesity and ageing impair the vasodilator response of the muscle microvasculature to insulin, exercise and VEGF-A and reduce microvascular density. Both impairments contribute to the development of insulin resistance, obesity and chronic age-related diseases. A physically active lifestyle keeps both the vasodilator response and microvascular density high. Intravital microscopy has shown that microvascular units (MVUs) are the smallest functional elements to adjust blood flow in response to physiological signals and metabolic demands on muscle fibres. The luminal diameter of a common terminal arteriole (TA) controls blood flow through up to 20 capillaries belonging to a single MVU. Increases in plasma insulin and exercise/muscle contraction lead to recruitment of additional MVUs. Insulin also increases arteriolar vasomotion. Both mechanisms increase the endothelial surface area and therefore transendothelial transport of glucose, fatty acids (FAs) and insulin by specific transporters, present in high concentrations in the capillary endothelium. Future studies should quantify transporter concentration differences between healthy and at risk populations as they may limit nutrient supply and oxidation in muscle and impair glucose and lipid homeostasis. An important recent discovery is that VEGF-B produced by skeletal muscle controls the expression of FA transporter proteins in the capillary endothelium and thus links endothelial FA uptake to the oxidative capacity of skeletal muscle, potentially preventing lipotoxic FA accumulation, the dominant cause of insulin resistance in muscle fibres

Investigation on patterns of water mite abundance on host damselflies and their effect on mating success.

Water mite parasitism is expected to have important effects on damselfly survivorship and reproductive success. The mites drain considerable amounts of bodily fluid from their hosts, increasing greatly in size during the parasitic phase of their life cycle. Studies in the past have repeatedly shown conflicting results regarding the effects of the water mites on their hosts. In order to investigate these opposing ideas, two day trips to Sugar Island in the Michigan Upper Peninsula were scheduled during which damselflies of the species Enallagma hageni were collected at the water's edge, looking for both single and copulating individuals. The data collected was analyzed using Systat. Results showed a moderate correlation between prevalence of parasitism and sex, with greater percentages of females hosting parasites compared to males. Greater abundances of mites were present on the larger damselflies, indicating a significant increasing linear regression of mite load versus body mass. No difference was noted between either males or females in copulation and mite prevalence. While no reproductive consequence was noted in this study on the damselflies hosting parasites, the water mites do negatively affect their hosts in other ways not related to reproduction.http://deepblue.lib.umich.edu/bitstream/2027.42/55079/1/3524.pdfDescription of 3524.pdf : Access restricted to on-site users at the U-M Biological Station

Primary Cutaneous Cryptococcosis Treated with Debridement and Fluconazole Monotherapy in an Immunosuppressed Patient: A Case Report and Review of the Literature

Cryptococcus neoformans is an opportunistic yeast present in the environment. Practitioners are familiar with the presentation and management of the most common manifestation of cryptococcal infection, meningoencephalitis, in patients with AIDS or other conditions of immunocompromise. There is less awareness, however, of uncommon presentations where experience rather than evidence guides therapy. We report a case of primary cutaneous cryptococcosis (PCC) in a patient who had been immunosuppressed by chronic high-dose corticosteroid for the treatment of severe asthma. This case highlights the importance of early recognition of aggressive cellulitis that fails standard empiric antibiotic treatment in an immunocompromised patient. It also demonstrates successful treatment of PCC with a multispecialty approach including local debridement and fluconazole monotherapy