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Biomedical subjects

S D Smith

Publications and source records attributed to S D Smith.

At least 325 records · Page 18Linked to original sources

Peroneus longus tendon lengthening as an adjuvant measure in cavus foot surgery.

Lengthening of the peroneus longus tendon is very important when performing cavus foot surgery. This tendon directly affects all three components (varus heel, increased arch height, and forefoot adduction) of the idiopathic cavus foot which can be accounted for by increased strength and activity of the peroneus muscle. The deforming force is removed or weakened according to the degree, duration and rigidity of the cavus foot by lengthening or transferring the tendon.

Foot↗

The effects of minute direct electrical currents on cultured chick embryo trigeminal ganglia.

The effects of low levels of electric current were determined on organ cultures of 6- to 19-day-old chick embryo trigeminal ganglia. Current levels ranged from 0.00115 to 11.5 nA/mm2; the time of electrical treatment varied from 2 h to 96 h. Low levels of electricity were found to have at least three major effects on this system of mixed cellular types: (1) Outgrowth of nerve fibers from the explant was enriched. This resulted in a greater number of fibers which were longer and more highly branched than those in control cultures. (2) Survival of neurons within the original explanted ganglion was enchanced by treatment with electricity. The presence of healthy neurons was found in 93.1% of the treated cultures and in 53.5% of untreated cultures. (3) Neurons, fibers and non-neural cells were stimulated to grow in the direction of the cathode. The rate of cathodal migration was calculated to be 0.1 mm/h (2.4 mm/day) in an explant from 12-day-old embryo. No differences were observed between surviving treated and control cultures in histochemical tests for acetycholinesterase. A similarity between the action of low levels of electrical current and nerve growth factor (NGF) is suggested.

Acetylcholinesterase↗

Effects of long-term rotation and hypergravity on developing rat femurs.

Male and female Sprague-Dawley rats derived from a single mating were raised for three generations under constant centrifugation at 1.03 G (Rotation Controls) and at 2 G. When the third generation rats were 3 months old, they were sacrificed, and their femurs removed. After fixation and cleaning, the femurs were then measured for length and diameter. Then right femurs were sectioned longitudinally, left femurs transversely. After staining with Hematoxylin and Eosin, right femurs were examined for ossification patterns and left femurs were measured for cortical thickness. All rotation control rats showed marked stimulation of ossification in the femoral head, and males showed significant cortical thinning when compared to non-rotated earth gravity controls. All 2 G femurs showed decreased length and aspect (L/D) ratios, and increased cortical thickness/diameter ratios when compared to earth controls or rotation controls. Ossification of the femoral head was slightly advanced, while the distal epiphyseal plate was thinned.

Animals↗