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Biomedical subjects

R B Layzer

Publications and source records attributed to R B Layzer.

16 recordsLinked to original sources
PubMed1992

Wolfram syndrome: evidence of a diffuse neurodegenerative disease by magnetic resonance imaging.

Wolfram syndrome is an autosomal recessive disorder beginning in childhood that consists of four cardinal features: optic atrophy, diabetes mellitus, diabetes insipidus, and neurosensory hearing loss. Aside from these features, the clinical picture is highly variable and may include other neurologic abnormalities such as ataxia, nystagmus, mental retardation, and seizures. We present two unrelated patients with Wolfram syndrome, both of whom had the four cardinal features and several other neurologic abnormalities. MRIs showed widespread atrophic changes throughout the brain, some of which correlated with the major neurologic features of the syndrome.

Adult↗
PubMed1979

Sporadic distal myopathy with early adult onset.

With the exception of the large series of adult-onset hereditary distal myopathy from Sweden, few cases of primary muscle disease with a definite distal predilection have been published. We report 3 sporadic cases of distal myopathy with the following features: (1) early adult onset (26 to 33 years); (2) slowly progressive weakness affecting first the distal leg muscles and later the arms; (3) marked elevation of creatine phosphokinase (more than 10 times the normal value); and (4) electromyographic and histological evidence of myopathy in distal muscles. The differential diagnosis is discussed and other reported cases are reviewed. The differences between hereditary cases reported by others and the sporadic cases reported here form the basis for a tentative subclassification of this syndrome.

Adult↗
PubMed1978

Myeloneuropathy after prolonged exposure to nitrous oxide.

A neurological disorder developed after prolonged exposure to nitrous oxide in 15 patients, all but 1 of whom were dentists. 13 patients had abused nitrous oxide to some extent for periods ranging from 3 months to several years, but 2 patients were exposed to nitrous oxide only professionally, by working in poorly ventilated surgeries. Symptoms included early sensory complaints, Lhermitte sign, loss of balance, leg weakness, gait ataxia, impotence, and sphincter disturbances. Neurological examination showed sensorimotor polyneuropathy, often combined with signs of involvement of the posterior and lateral columns of the spinal cord. Electrodiagnostic tests pointed to an axonal polyneuropathy, but other laboratory results were normal, including examination of the spinal fluid. The neurological picture is similar to that of subacute combined degeneration of the spinal cord, and it is possible that nitrous oxide interferes with the action of vitamin B12 in the nervous system.

Adult↗
PubMed1978

Neuropathy following abuse of nitrous oxide.

A disabling peripheral neuropathy, mainly sensory, developed in three health workers who habitually abused nitrous oxide. The distinctive clinical picture included patterns of numbness that were radicular rather than purely distal, and a "reverse" Lhermitte sign, in the absence of signs of spinal cord involvement. Nerve conduction studies suggested an axonal rather than demyelinative neuropathy. The neurologic disorder improved slowly when the patients abstained from further nitrous oxide abuse.

Adult↗
PubMed1977

Nonidentical subunits of human erythrocyte phosphofructokinase.

Human erythrocyte and muscle phosphofructokinase (PFK) were purified completely by improved procedures. SDS-acrylamide gel electrophoresis in a discontinuous buffer system revealed two subunits (R and M) of erythrocyte PFK, the slower one (M) corresponding to the single subunit of muscle PFK. The staining intensity ratio R:M of the two bands of erythrocyte PFK was 2:1 or less. This suggests that native erythrocyte PFK contains multiple isoenzymes with different proportions of R and M, some being lost during purification. Nevertheless, isoelectric focusing showed single peaks of erythrocyte PFK (pI 5.0) and muscle PFK (pI 6.6), perhaps because of aggregation of erythrocyte PFK isoenzymes. Erythrocyte PFK from a patient with muscle PFK deficiency had a pI of 4.6 and could not be precipitated by antiserum against muscle PFK, findings compatible with the putative structure R4.

Chromatography, DEAE-Cellulose↗
PubMed1977

The declining electrical response of muscle to repetitive nerve stimulation in myotonia.

The electrical response of muscle to repetitive nerve stimulation was studied in patients with various myotonic disorders. A decrementing response was common but not invariable finding, and was unrelated to the severity or diagnosis. The decrement either continued throughout the period of stimulation or "leveled off", sometimes being followed by an increment. If it occurred at low rates of stimulation, a greater decrement occurred at higher rates, usually after a shorter latent period. It was not related consistently to the presence of weakness, but in patients with myotonia congenita it was more conspicuous and elicited by lower rates of stimulation when transient weakness was a feature of the history.

Adolescent↗
PubMed1976

Hypothenar Dimpling. A peripheral equivalent of Hemifacial Spasm?

In two patients, the skin over both hypothenar eminences underwent intermittent, spontaneous, irregular, dimpling contractions. The dimpling was benign, and was the result of spontaneous discharge of motor units in the palmaris brevis muscle. Electrophysiological investigations localized the site of origin of the discharge to the ulnar nerve, possibly at the wrist, but there was no clinical or physiological evidence of neuropathy or of nerve compression. In many respects, the clinical and electrophysiological features of hypothenar dimpling resemble hemifacial spasm.

Aged↗
PubMed1975

Plasma albumin concentration and diphenylhydantoin binding in man.

The plasma protein binding of diphenylhydantoin sodium was determined in 26 patients who had been taking diphenylhydantoin regularly for more than two weeks. The free (unbound) diphenylhydantoin level was found to vary from 5.8% to 12.6% of the total drug concentration. This range of variation may be clinically important, if it can be established that the binding of diphenylhydantoin to plasma proteins limits entry of the drug into the brain. The binding of diphenylhydantoin was directly proportional to the plasma albumin concentration, which thus appeared to be the most important determinant of diphenylhydantoin binding. Diphenylhydantoin binding was independent of the plasma concentration of the drug in the usual therapeutic range. In vitro studies showed little effect by phenobarbital sodium or penicillin G; therapeutic levels of acetylsalicylic acid, however, increased free diphenylhydantoin by nearly 50%.

Adolescent↗
PubMed1975

Neuromuscular complications of acromegaly.

Seventeen consecutive acromegalic patients were evaluated for evidence of neuromuscular dysfunction and followed for 1 year after hypophysectomy. Before treatment, four patients had both a myopathy and the carpal tunnel syndrome, five had myopathy alone, four had carpal tunnel syndrome alone, and four had neither. The myopathy was caracterized by mild, strictly promixal weakness and flabbiness of muscles; electromyography revealed typical myopathic abnormalities, but serum enzymes and muscle biopsy usually were normal. The presence of myopathy or the carpal tunnel syndrrome could not be correlated with the magnitude of growth hormone elevation or any secondary endocrine derangement, but myopathy was associated with a longer duration of acromegaly. Carpal tunnel symptoms usually improved in the first 6 weeks after hypophysectomy, while myopathy improved more slowly and sometimes was detectable 1 year later.

Acromegaly↗
PubMed1975

Remediable neuromuscular disorders.

Generalized muscular weakness may develop from a variety of causes, and in many cases is reversible with appropriate treatment of the underlying disorder.

Adult↗