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PubMed1977

Peripheral nerve abnormality in multiple sclerosis.

Biopsy specimens of sural nerve from 10 patients with multiple sclerosis (MS), of whom only 1 was severely disabled, were assessed by morphometric techniques and compared to nerves from age-matched controls. The frequency of abnormal teased fibers was increased in MS nerve, with many internodes showing at least a 50% reduction in myelin thickness. Myelinated nerve fiber densities were not significantly different in MS and control nerves. Regression analysis of axonal area on number of myelin lamellae indicated a generalized reduction of myelin lamellae in this disorder. It is suggested that peripheral myelin may be involved in multiple sclerosis.

Axons↗

PubMed1975

Academic achievement, situational stress, and problem-solving flexibility.

Academic overachieving (n equals 12) and underachieving (n equals 10) tenth grade boys were randomly assigned, with their parents, to either a success or a failure treatment in a problem solving task to determine the effects of induced stress on problem solving flexibility. For the underachievers, Ss in the success treatment were the most flexible, while for the overachievers, Ss in the failure treatment were the most flexible. A curvilinear proposition, consistent with Hebb's cue-arousal postulate was proposed to explain the results and also to explain the apparent discrepancies in the literature as to whether situational stress increases or decreases flexibility in problem solving. An implication of the proposition is that for persons with feelings of personal inadequacy, increases in situation stress result in decreased problem solving flexibility, but for persons with feelings of personal adequacy such increases enhance their problem solving flexibility.

Achievement↗