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Biomedical subjects

D F Farrell

Publications and source records attributed to D F Farrell.

At least 37 records · Page 2Linked to original sources
PubMed1978

The effect of Mycoplasma contamination on the in vitro assay of pyruvate dehydrogenase activity in cultured fibroblasts.

Cultured fibroblasts contaminated with mycoplasma were shown to have increased in levels of apparent pyruvate dehydrogenase and pyruvate dehydrogenase complex enzyme activity. The apparent pyruvate dehydrogenase specific activity was about 1000-fold greater in cultured Mycoplasma pneumoniae than in cultured fibroblasts. Several acid hydrolytic enzyme activities were also shown to be present in M. pneumoniae though a lower apparent specific activity than in cultured fibroblasts.

Cell Line↗
PubMed1978

Antenatal diagnosis of Krabbe's leucodystrophy: enzymatic and morphological confirmation in an affected fetus.

Galactosylceramide beta-galactosidase activity was assayed in cultured amniotic fluid cells from two pregnancies at risk for Krabbe's leucodystrophy. The elective termination of one pregnancy was carried out after demonstration of a severe deficiency of galactosylceramide beta-galactosidase activity. The diagnosis of Krabbe's leucodystrophy in the affected fetus was confirmed enzymatically by a deficiency of galactosylceramide beta-galactosidase inbrain, liver, kidney, and cultured skin fibroblasts, and histologically by the ultrastructural demonstration of the typical intracellular inclusions in cells of the spinal cord.

Amniocentesis↗
PubMed1977

Skin punch biopsy in the diagnosis of juvenile neuronal ceroid-lipofuscinosis. A comparison with leukocyte peroxidase assay.

Electron microscopical examination of skin punch biopsy specimens was compared with the leukocyte peroxidase assay in establishing the diagnosis of juvenile neuronal ceroid-lipofuscinosis in three families with at least one affected child. Although the leukocyte peroxidase assay failed to distinguish between the patients, heterozygotes, and normal subjects, skin biopsy specimens containing characteristic cytosomes were found only in the children with this disease. In fact, in two families, the three affected members were identified by this method after the biopsy specimens had been randomized. Although only one to four cells containing such cytosomes were identified in each patient, not only cytosomes with curvilinear bodies but also those with rectilinear as well as "fingerprint" profiles were found. Thus, the skin punch biopsy appears to be a useful diagnostic aid the juvenile as well as the late infantile forms of neuronal ceroid-lipofuscinosis.

Adolescent↗
PubMed1976

"Giant axonal neuropathy" caused by industrial chemicals: neurofilamentous axonal masses in man.

Symmetrical polyneuropathy developed in two patients after they had been in contact with acrylamide and methyl n-butyl ketone, respectively. In sural nerve biopsy material from both patients, electron microscopy showed frequent focal axonal swellings containing masses of neurofilaments. Some axons undergoing axonal degeneration also were seen. These morphologic features are identical to those produced in experimental animals after exposure to these chemicals and are similar to those found in n-hexane neuropathy and in the three reported cases of giant axonal neuropathy. Sural nerve biopsy is an important diagnostic test in identifying cases of peripheral neuropathy caused by these chemicals.

Acrylamides↗
PubMed1976

Krabbe's leukodystrophy without globoid cells.

Krabbe's infantile cerebral sclerosis with a prolonged course was present in a boy who became increasingly hypertonic during infancy and had an increased protein level in the spinal fluid. At 4 years he showed significant growth failure, profound mental retardation, spastic quadriplegia, bilateral optic atrophy, and depressed tendon reflexes. Conduction velocity in motor fibers of the median nerve had become progressively impaired. Autopsy at 5 years 10 months showed severe leukodystrophy with demyelination and gliosis. No stored breakdown products or globoid cells were seen in the brain. Galactosyl ceramide beta-galactosidase was virtually absent, and hardly any myelin was demonstrable on chemical and electron microscopic studies. The presence of globoid cells may not be essential for the pathologic diagnosis of Krabbe's leukodystrophy in the presence of appropriate enzyme deficiency.

Brain↗
PubMed1976

Electrophysiologic observations in the classical form of Pelizaeus-Merzbacher disease.

In a 20-year-old patient with the classic form of Pelizaeus-Merzbacher disease, electroencephalograms during wakefulness were moderately diffusely abnormal, and an overnight polygraphic sleep recording showed distorted nonrapid eye movement sleep patterns without vertex sharp waves, K-complexes, spindles, or positive occipital sharp transients. Rapid eye movement sleep could be identified. Cerebral responses evoked by light flashes, clicks, and electric stimulation of the median nerves were abnormal.

Adult↗
PubMed1976

Herpes simplex neuropathy.

Atypical facial pain and permanent sensory loss in the second and third divisions of the trigeminal nerve developed in a patient who had had multiple attacks of herpes simplex neuralgia over a period of 8 years. Intravenous cytosine arabinoside failed to prevent a recurrence of the vasicular eruption, but carbamazepine produced symtomatic pain relief. This case demonstrates that herpes simplex can closely mimic herpes zoster as a cause of postherpetic neuralgia and suggests a possible etiology of atypical facial pain and/or trigeminal sensory neuropaty in some patients.

Adult↗
PubMed1975

Absence of pyruvate decarboxylase activity in man: a cause of congenital lactic acidosis.

A complete deficiency in the pyruvate dehydrogenase system activity contributed to the death of a 6-month-old infant with congenital lactic acidosis. The enzymatic block could be isolated to the first component, pyruvate decarboxylase (E1) of the pyruvate dehydrogenase complex. This enzymatic deficiency allowed a demonstration of an "intercomplex" exchange of the components of the mammalian pyruvate dehydrogenase system and indicated that the first component is normally present in an apparent excess.

Acidosis↗
PubMed1975

Congenital insensitivity to noxious stimuli.

Cerebral-evoked potentials were used to study a 25-year-old man, the older of two siblings with congenital insensitivity to all noxious stimuli, gross impairment of temperature perception, and anhidrosis. Electrical stimulation of tooth pulp consistently eliciting pain and cerebral responses in normal subjects evoked neither cerebral potentials nor painful or other sensations in our patient. However, ordinarily painful electric shocks to the skin of his face evoked cerebral responses as well as sensations lacking disagreeable qualities. Those cerebral potentials elicited by electrical stimulation of the median nerve, clicks, and light flashes were within normal limits. These findings strongly suggest that a defect in transmission of noxious impulses presumably involving first order sensory neurons exists in our patient.

Adult↗
PubMed1971

Neuronal GM1 gangliosidosis in a Siamese cat with beta-galactosidase deficiency.

A juvenile Siamese cat with severe, progressive motor disability was shown to have extensive neuronal degeneration caused by accumulation of GM(1) ganglioside. Tissues from brain and kidney were markedly deficient in beta-galactosidase activity. The disease in this cat is thought to be inherited as an autosomal recessive trait, and is strikingly similar to juvenile GM(1) gangliosidosis of children.

Animals↗