Citations

Jensen, Michael D., Tu T. Nguyen, A. Hernández Mijares, C. Michael Johnson, and Michael J. Murray. Effects of gender on resting leg blood flow: implications for measurement of regional substrate oxidation. J. Appl. Physiol. 84(1): 141–145, 1998.—These studies were designed to examine whether the respiratory quotient (RQ) of leg tissue (primarily skeletal muscle) would increase to a greater degree in women than in men during meal ingestion. We found that mean leg and systemic RQ values were similar in men under both basal and fed conditions, whereas the agreement was poor in women. In women, leg RQ values tended to be greater than the systemic RQ, whereas splanchnic RQ values tended to be lower than the systemic RQ. The possibility that measurement imprecision accounted for the different findings in women could not be excluded because the arteriovenous blood O2 differences were almost twice as great in men as in women (53.7 ± 5.4 vs. 28.6 ± 2.9 ml of O2/l, respectively; P < 0.01), as were venoarterial blood CO2 differences. The smaller arteriovenous differences in women appeared to limit our ability to accurately measure their leg RQ values. O2 uptake relative to leg fat-free mass (FFM) was not different between men and women, whereas leg blood flow relative to leg FFM was greater in women than in men (55 ± 3 vs. 39 ± 2 ml ⋅ kg FFM−1 ⋅ min−1, respectively; P < 0.001). These findings were confirmed by examining data from other studies conducted in our laboratory to create a larger data set. We conclude that resting leg blood flow in women is greater (relative to FFM) than in men, making it more difficult to accurately measure leg RQ in women.

These studies were conducted to determine whether there are gender-specific regional differences in meal triglyceride fatty acid uptake. Systemic and regional oleate ([3H]oleate) kinetics were measured in nine nonobese men and eight nonobese women before and at the end of a 6-h meal, administered as small frequent feedings to achieve steady-state chylomicronemia. Chylomicron uptake in the splanchnic bed accounted for 71 +/- 15% of meal triglyceride disappearance in men and 20 +/- 7% in women (P < 0.01), whereas leg chylomicron uptake could only account for 12 +/- 2 and 8 +/- 4% (P not significant in men vs. women) of meal triglyceride disappearance. Meal ingestion suppressed (P < 0.05) systemic and regional free fatty acid release in both men and women. Splanchnic nonchylomicron triglyceride release and leg nonchylomicron triglyceride uptake were not significantly different in men and women. In summary, the largest quantitative difference between men and women in fatty acid kinetics during meal ingestion is a substantially greater splanchnic uptake of meal triglyceride fatty acids in men. This could represent greater meal fatty acid storage in visceral adipose tissue.

A case involving a retired, elderly male war veteran with a symptomatic peroneus brevis muscle hernia causing superficial peroneal nerve compression with chosen surgical management is presented. Symptomatic muscle hernias of the extremities occur most commonly in the leg and are a rare cause of chronic leg pain. Historically, treating military surgeons pioneered the early documentation of leg hernias observed in active military recruits. A focal fascial defect can cause a muscle to herniate, forming a variable palpable subcutaneous mass, and causing pain and potentially neuropathic symptoms with nerve involvement. While the true incidence is not known, the etiology has been classified as secondary to a congenital (or constitutional) fascial weakness, or acquired fascial defect, usually secondary to direct or indirect trauma. The highest occurrence is believed to be in young, physically active males. Involvement of the tibialis anterior is most common, although other muscles have been reported. Dynamic ultrasonography or magnetic resonance imaging is often used to confirm diagnosis and guide treatment. Most symptomatic cases respond successfully to conservative treatment, with surgery reserved for refractory cases. A variety of surgical techniques have been described, ranging from fasciotomy to anatomical repair of the fascial defect, with no consensus on optimal treatment. Clinicians must remember to consider muscle hernias in their repertoire of differential diagnoses for chronic leg pain or neuropathy. A comprehensive review of muscle hernias of the leg is presented to highlight their history, occurrence, presentation, diagnosis and treatment.

Abstract Introduction Comparative transcriptome analyses in Alzheimer's disease (AD) and other neurodegenerative proteinopathies can uncover both shared and distinct disease pathways. Methods We analyzed 940 brain transcriptomes including patients with AD, progressive supranuclear palsy (PSP; a primary tauopathy), and control subjects. Results We identified transcriptional coexpression networks implicated in myelination, which were lower in PSP temporal cortex (TCX) compared with AD. Some of these associations were retained even after adjustments for brain cell population changes. These TCX myelination network structures were preserved in cerebellum but they were not differentially expressed in cerebellum between AD and PSP. Myelination networks were downregulated in both AD and PSP, when compared with control TCX samples. Discussion Downregulation of myelination networks may underlie both PSP and AD pathophysiology, but may be more pronounced in PSP. These data also highlight conservation of transcriptional networks across brain regions and the influence of cell type changes on these networks.