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Biomedical subjects

A G Engel

Publications and source records attributed to A G Engel.

At least 217 records · Page 12Linked to original sources
PubMed1975

Human muscle fiber fine structure: morphometric data on controls.

Muscle fiber fine structure was quantitatively analyzed in 70 longitudinally and 65 transversely sectioned fibers from 10 control subjects without weakness. The average mitochondrial fraction of the fiber volume is close to 4 percent and the mean size of a mitochondrion is about 0.1 mum2. The sarcotubular surface area per unit fiber volume is close to 1.5 mum2/mum3 in transverse sections and 0.65 times this value in longitudinal sections. Only one-third of all fibers contain lipid droplets in the sectioned plane, and for all fibers the droplets account for approximately 0.12 percent of the fiber volume. Variations with the age and sex of the subjects and with different muscles were analyzed and the feasibility of typing human muscle fibers at the ultrastructural level was evaluated.

Adult↗
PubMed1974

Muscle blood flow in Duchenne type muscular dystrophy, limb-girdle dystrophy, polymyositis, and in normal controls.

Muscle blood flow (MBF) was measured using the local (133)Xenon injection method in patients with Duchenne type muscular dystrophy (six), limb-girdle dystrophy (four), polymyositis (seven), and in normal controls (11). Measurements were made at rest and during hyperaemia induced by ischaemic exercise and by histamine injection. Capillary diffusion capacity was measured with the (51)Cr-EDTA method in three patients with Duchenne dystrophy and in six normal controls. Patients with Duchenne dystrophy had normal MBF during rest and during hyperaemia after exercise and significantly increased MBF after histamine injection. The capillary diffusion capacity was higher than normal, but not significantly. In limb-girdle dystrophy MBF was normal, while in polymyositis it was significantly decreased in all three circulatory states. The relevance of the findings to the proposed ischaemic aetiology of Duchenne dystrophy is considered.

Capillary Permeability↗
PubMed1973

Carnitine deficiency of human skeletal muscle with associated lipid storage myopathy: a new syndrome.

In a rare myopathy muscle fibers contained myriad lipid-filled vacuoles. Homogenates of the patient's muscle oxidized fatty acids more slowly than normal (11 controls). Addition of carnitine increased the oxidation rate with the patient's muscle to the level attained by the controls with carnitine. In five separate muscle samples from the patient the mean carnitine level was less than 20 percent of that observed in 42 controls. Carnitine palmityl transferase and palmityl thiokinase levels in the patient's muscles were not depressed. The present case represents the first recognized instance of carnitine deficiency in human skeletal muscle.

Acyltransferases↗