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Biomedical subjects

R G Gray

Publications and source records attributed to R G Gray.

At least 73 records · Page 4Linked to original sources
PubMed1985

Glutaric aciduria type I misdiagnosed as Leigh's encephalopathy and cerebral palsy.

Two cases are reported of boys who suffer epileptic seizures only after playing video games. It is suggested that the amount of time the patient spends in front of the screen before the seizure is important, and also that video games trigger electrocortical activity far more efficiently than either television or intermittent photic stimulation.

Amino Acid Metabolism, Inborn Errors↗
PubMed1985

Mitochondrial malic enzyme in Friedreich's ataxia: failure to demonstrate reduced activity in cultured fibroblasts.

Mitochondrial and cytosolic malic enzymes were assayed radiochemically in fibroblasts from six patients suffering from Friedreich's ataxia in order to verify earlier reports of abnormalities in these enzymes. No abnormalities could be detected in the activities of either enzyme. On cellulose acetate electrophoresis a band of enzyme activity corresponding to the mitochondrial isoenzyme was detectable contrary to earlier reports. Possible explanations for the disparity of results between different laboratories are discussed.

Adolescent↗
PubMed1985

Genetic linkage analysis of the carpal tunnel syndrome.

Two generations of a family with autosomal dominant carpal tunnel syndrome were studied for genetic linkage to 20 informative polymorphic blood markers. No linkage was demonstrated between the syndrome and the markers tested; exclusion of close linkage (lod score less than -2.0) was found for MNSs, ACP, GALT, GPT, GLO, Hp, Gc, and Pi.

Carpal Tunnel Syndrome↗
PubMed1985

There is no such thing as ageing, and cancer is not related to it.

Several separate cellular processes have to accumulate in a normal cell to alter it into the seed of a growing carcinoma. Even though cancer is much commoner in the old than in the young, there is no good evidence whatever that these separate processes have any systematic tendency to take place more readily among old than among young adults. (Indeed, there are some instances in which carcinogenic treatments actually elicit cancer less rapidly among the old!) There are obvious evolutionary reasons why substantial cancer risks should be delayed until the end of the usual lifespan, and it appears that this is achieved chiefly not by having the component processes of neoplastic transformation themselves particularly dependent on age, but simply by requiring not one, but several, of them en route from full normality to full malignancy, and by giving at least some of them an extraordinarily low daily probability. The daily probabilities of these separate events are, of course, under evolutionary influence, and some of them appear to have changed by orders of magnitude over the tens of millions of years of evolution that separate humanity from various short-lived animals.

Adult↗
PubMed1984

Biochemical investigations on a patient with a defect in cytosolic acetoacetyl-CoA thiolase, associated with mental retardation.

A severely mentally retarded boy with two normal siblings was persistently found to excrete elevated amounts of 3-hydroxybutyrate and acetoacetate. Enzyme analysis in cultured fibroblasts revealed a probable deficiency in cytosolic acetoacetyl-CoA thiolase which was about half the control activity with normal mitochondrial thiolase activities. Treatment with reduced dietary fat was initiated and a rapid reduction of the ketosis to biochemical normality was demonstrated. Shortly after initiating dietary treatment he presented with severe gastrointestinal problems and the histological features of colitis cystica superficialis. This appeared to respond to intravenous hydrocortisone therapy with an apparent complete recovery.

Acetyl-CoA C-Acetyltransferase↗
PubMed1984

Glutaric aciduria type II: biochemical investigation and treatment of a child diagnosed prenatally.

Two sibs with the acute neonatal form of glutaric aciduria type II (deficient in vivo activity of multiple acyl-CoA dehydrogenases) are described. In the second case diagnosis was made prenatally on the basis of reduced oxidation of palmitate by cultured amniotic fluid cells. With prompt intervention in the neonatal period and a carefully controlled diet later, this second progressed well up to 4 months of age but died suddenly of cardiac failure, probably attributable to accumulation of fat. Neither patient showed any congenital morphological abnormality. Cultured fibroblasts from the second case showed a marked defect in the oxidation of a range of substrates requiring acyl-CoA dehydrogenases for their catabolism, but residual activity for some substrates was quite high. Large quantities of sarcosine were excreted in urine, again suggesting that the mutation leaves some residual dehydrogenation activity. Butyryl-, octanoyl- and palmitoyl-CoA dehydrogenases were present in essentially normal quantities in postmortem liver.

Adipates↗
PubMed1983

Studies on the pathway from ornithine to proline in cultured skin fibroblasts with reference to the defect in hyperornithinaemia with hyperammonaemia and homocitrullinuria.

The reduction in the conversion of ornithine to proline by fibroblasts from a patient with hyperornithinaemia with hyperammonaemia and homocitrullinuria cannot be explained by a reduced uptake of exogenous ornithine, an altered total intracellular ornithine content, or reduced conversion of gamma-glutamate semialdehyde to proline. However, neither could the postulated defect in mitochondrial ornithine uptake be demonstrated using the digitonin method. Increasing the ornithine concentration in the medium increased the incorporation of 14C label from ornithine into protein in both the patient's and control cells. In the patient's cells the apparent Km for ornithine was ten times that of the controls, although the Vmax values were comparable. This result parallels the clinical response to ornithine supplementation.

Amino Acid Metabolism, Inborn Errors↗
PubMed1983

The relationship between physical activity and serum lipids and lipoproteins in black children and adolescents.

This study assesses the association between the serum lipid and lipoprotein levels of 62 black children and 37 black adolescents and their reported levels of habitual physical activity, 24-hour dietary intake, and physical measurements. In the children physical activity was not correlated with serum lipid and lipoprotein levels. Indicators of physical activity had a positive correlation (P less than 0.02) with high-density-lipoprotein cholesterol and negative correlations (P less than 0.05) with the total serum cholesterol/high-density-lipoprotein cholesterol and low-density-lipoprotein cholesterol/high-density-lipoprotein cholesterol ratios in the adolescents. Subjects were stratified into "low activity" and "high activity" groups. High-activity subjects had lower (P less than 0.05) total serum cholesterol/high-density-lipoprotein cholesterol and low-density-lipoprotein cholesterol/high-density-lipoprotein cholesterol ratios than less active subjects. Subjects that ran track had lower (P less than 0.02) total serum cholesterol and low-density-lipoprotein cholesterol than non-track participants. The results suggest that increased habitual physical activity may have a favorable effect on serum lipid and lipoprotein levels in black adolescents.

Adolescent↗
PubMed1983

The relevance in adults of air-flow obstruction, but not of mucus hypersecretion, to mortality from chronic lung disease. Results from 20 years of prospective observation.

From 1954 to 1961, pulmonary function was assessed in 2,718 British men by forced expiratory maneuvers, and mucus hypersecretion and smoking habits were assessed by questionnaires. In 20 to 25 yr of follow-up, 104 men (all of whom had smoked) died of chronic obstructive pulmonary disease (COPD). The risk of death from COPD was strongly correlated with the initial degree of air-flow obstruction. Among men with similar initial air-flow obstruction, however, age-specific COPD death rates were not significantly related to initial mucus hypersecretion, supporting the concept that air-flow obstruction and mucus hypersecretion are largely independent disease processes. A moderate relationship existed between initial mucus hypersecretion and subsequent lung cancer mortality, but it is not known whether this was due solely to a common correlation of both conditions with the effective degree of exposure of the large bronchi to causative factors such as tobacco smoke.

Adult↗
PubMed1983

Necrotizing vasculitis as the initial manifestation of rheumatoid arthritis.

A 64-year-old Black woman presented with high titer serum rheumatoid factor (RF), pelvic girdle weakness, sensory mononeuropathy, pulmonary fibrosis, and muscle histologic evidence of small artery necrotizing vasculitis. High dose corticosteroid therapy was followed by clinical improvement and reduction in serum RF titer. Four years later, and 9 months after discontinuance of corticosteroids, she developed an inflammatory polyarthritis, recurrent muscle weakness, and left foot drop, concomitantly with circulating immune complexes and extremely high titer serum RF. Necrotizing vasculitis is a distinctly rare presenting manifestation of rheumatoid disease.

Arthritis, Rheumatoid↗