David R. Pendergast

Phenotypic variability among first‐degree relatives with carnitine palmitoyltransferase II deficiency

Carnitine palmitoyltransferase (CPT) II deficiency disorders are clinically very variable. To examine the cause(s) of variable symptoms in first‐degree relatives with CPT II deficiency, four sisters with various combinations of mutations and polymorphisms in the CPT2 gene were studied, together with 20 sedentary and 24 trained healthy female subjects. One sister, whose symptoms began at age 7 years, was more severely affected than her older sister, whose symptoms began at age 16 years; both were compound heterozygotes for the common S113L mutation and Q413fs, and for the common CPT2 polymorphisms, V3681 and M647V. A third sister became hypoglycemic with fasting, was heterozygous for the S113L mutation, and homozygous for the polymorphism variants. The fourth sister was asymptomatic, heterozygous for the Q413fs mutation, and homozygous for the normal polymorphisms. Residual CPT II activity in skeletal muscle and cultured skin fibroblasts from the two myopathic sisters, and palmitate oxidation in fibrobasts, were abnormally low; cellular and total body fat oxidation were also diminished. Muscle function and fat oxidation were nomal at rest, but a switch to carbohydrate utilization occurred at lower exercise intensities than in sedentary and trained individuals, respectively. Reliance on carbohydrates during stress and hormonal alterations may explain, in part, the variance in ages of onset and serverity of symptoms in myopathic patients.

Peripheral circulation inAlligator mississippiensis effects of diving, fear, movement, investigator activities, and temperature

Summary1.Cutaneous and skeletal muscle blood flows cease when alligators are forcibly submerged or when they are disturbed by the investigator. Contrary to previous reports, blood flow to the musculature and tail of freely diving alligators remains normal during submergence, as measured with133Xe (Fig. 2). Cardiovascular adjustments previously reported for diving reptiles appear to be due largely to a psychogenic response (fear) induced by experimental manipulation.2.Handling and experimental manipulation cause a statistically significant elevation in peripheral blood flow at the beginning of an experiment. Blood flow then gradually decreases and reaches a steady-state after 30 min. Muscles and skin are minimally perfused when at rest. Standard blood flows for muscle ranged from 0.004 to 0.049 ml·g−1 min−1n

Effects of acceleration in the Gz axis on human cardiopulmonary responses to exercise

(bar X = 0.018)

Active Heating/Cooling Requirements for Divers in Water at Varying Temperatures

n and for skin ranged from 0.006 to 0.039n

The Role of Dietary Fat on Performance, Metabolism, and Health:

(bar X = 0.016)

Lipids, Exercise, and Immunology

n.3.Voluntary movement in the absence of disturbance results in a statistically significant increase in blood flow (Figs. 3 and 4). When alligators struggle against a restraint their muscles undergo isometric contraction and blood flow ceases (Fig. 3).4.Skin blood flow is elevated at temperatures above 30°C during the early portion (<30 min) of experiments (Fig. 4). There are no differences in flows during heating, cooling or steady-state conditions at the same temperature.5.Muscle blood flow is insensitive to temperature between 25°C and 35°C and increases in response to exercise.