Biomedical subjects
Publications and source records attributed to T W Crosby.
A woman had episodes of bilateral thermal sensation, initially thought to be hot flashes related to menopause. EEG telemetry documented the epileptic nature of the attacks with an electrographic seizure emanating from the right temporal area coincident with the hot flashes.
Fluorescent protease histochemical analysis of muscle biopsy specimens from two patients with nemaline myopathy revealed the apparent absence of one proteolytic enzyme, dipeptidyl peptidase. Although the function of peptidases in normal muscle is obscure, this abnormality suggests that proteases may participate in posttranslational modification of proteins that are to be assembled into Z lines or, alternatively, in the disassembly and degradation of Z-line material.
A 43-year-old woman who indiscriminately took colchicine for five years developed a progressive multisystem syndrome that included severe axonal neuropathy and a pathologically striking myopathy. The neuropathy and myopathy were similar to experimental animal colchicine-induced neuromuscular toxicity.
We report two siblings with a mitochondrial encephalomyopathy. The syndrome was characterized by ataxia, intellectual impairment, myoclonic jerks, rare seizures, and small stature. Muscle biopsy specimens showed abnormal accumulations of mitochondria and lipid droplets. Biochemical studies on muscle demonstrated decreased succinate-cytochrome c reductase activity in the mitochondrial respiratory chain.
A patient is described who presented with isolated episodes of typical angina pectoris. Subsequent exercise electrocardiogram was positive, and cardiac catheterization revealed a 90 percent lesion of a nondominant right coronary artery supplying only the right ventricular (RV) myocardium. The left coronary artery was normal. Stress gated equilibrium radionuclide angiograms (RNA) revealed a normal left ventricular exercise response and a markedly abnormal RV response (RV ejection fraction decreased from 31 percent at rest to 27 percent at peak stress). Nondominant right coronary artery lesions can be a source of angina pectoris, RV infarction, and a positive ECG response to exercise. Stress RNA can be useful in evaluating the functional significance of these lesions.
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A remarkably observant 89-year-old woman experienced the abrupt onset of musical hallucinations on the background of longstanding progressive hearing loss and in the absence of psychosis or major dementia. These hallucinations were nearly constant, wellformed perceptions of religious hymns, and their content could be altered by several mechanisms. The patient also occasionally heard voices recapitulating childhood experiences. One can speculate that the syndrome relates to sensory deprivation.
The myelopathy and neuropathy associated with chronic misuse of nitrous oxide are potentially reversible if the habit is discontinued. This occurred in each of the reported cases, including our case, when it was transiently discontinued. Although a causal relationship between nitrous oxide and this myelopathy-neuropathy has not been proved, the circumstantial evidence is convincing. Both physicians and dentists should be aware of this potentially serious complication of chronic self-administration of nitrous oxide, especially in persons inclined to misuse drugs. Dentists, with their access to nitrous oxide, may be particularly at risk.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.