Search PubMed⌕ Search

Biomedical subjects

J David

Publications and source records attributed to J David.

At least 145 records · Page 8Linked to original sources
PubMed1979

Drosophila alcohol dehydrogenase activity in vitro and in vivo: effects of acetone feeding.

When adult Drosophila are placed on medium containing 0.5% acetone, their level of alcohol dehydrogenase activity drops rapidly. At the same time, the proportion of activity in the various electrophoretic forms of the enzyme shifts; most of the activity becomes localized in what is ordinarily a minor form of the enzyme. Moreover, the loss of enzyme activity occurs in vivo as well, as shown by sensitivity to ethanol poisoning, insensitivity to pentenol treatment, and inability to utilize ethanol as an energy source. These observations are discussed in light of a model advanced for the origin of the multiple forms of alcohol dehydrogenase in Drosophila.

Acetone↗
PubMed1979

Long-term treatment of Parkinson's disease with bromocriptine.

BRomocriptine (15-75 mg per day) alone or with L-dopa was studied during five to 29 months on 44 patients with Parkinson's disease. Used as sole therapeutic agent, it was found excellent in 12 patients who had never received regular L-dopa treatment either because it was never attempted or because of intolerance from the outset. Its anti-Parkinsonism activity was comparable with L-dopa. The gain was stable in the long term until this report. The side effects of L-dopa were not seen after bromocriptine. In cases where L-dopa had ceased to be active, bromocriptine produced a further improvement if mental deterioration was not associated. In very advanced forms of Parkinson's disease with associated dementia, bromocriptine did not produce durable results. Bromocriptine did not improve the "on-off" effects but reduced a number of the side effects of L-dopa, in particular cardiac, painful contractions, and dyskinesia without "on-off" effects.

Adult↗
PubMed1979

[Plasma cell beta-glucuronidase and monoclonal gammapathies (author's transl)].

beta-glucuronidase activity, estimated cytochemically, is, in more than half cases of myeloma, very increased or decreased, compared to that found in benign dysglobulinemias, where this activity is normal. A very high or very low score makes sure the diagnostic of myeloma. The relations between the beta-glucuronidase activity and the myeloma clinical stade according to Durie and Salmon and the bone lysis are discussed.

Clinical Enzyme Tests↗
PubMed1978

Alcohol metabolism in Drosophila melanogaster: uselessness of the most active aldehyde oxidase produced by the aldox locus.

Alcohol dehydrogenase is necessary for ethanol detoxification and metabolic utilization. It has been generally assumed that aldehyde oxidase (AO) produced by the Aldox locus (3-56.7) is necessary for a further transformation of acetaldehyde into acetate. We find that various mutant strains (ma-l or Aldoxn) which do not produce an active enzyme show about the same tolerance to alcohol as do wild strains. This physiological paradox is probably to be explained by the discovery of another locus (not localized) which produced a small amount of AO in all tested strains. The adaptive significance of the genetically polymorphic Aldox locus is probably to be looked for in physiological pathways other than ethanol metabolism.

Acetaldehyde↗
PubMed1978

Transsphenoidal encephalocele associated with agenesis of corpus callosum: value of metrizamide computed cisternography.

Transsphenoidal encephaloceles are rare congenital malformations that are classified among the medial dysraphias and that are therefore associated with an agenesis of the corpus callosum. Clinically, the diagnosis is difficult, but hypertelorism and weakening eyesight should be of suggestive value. Diagnosis is basically radiological. In the past, it was founded on roentgenography, tomography of the base of the skull, pneumoencephalography, and angiography when necessary. Today, metrizamide computed cisternography using axial transverse and coronal sections, supplemented by sagittal reconstructions, allows for a complete examination of bony, meningeal, and cerebral abnormalities.

Agenesis of Corpus Callosum↗
PubMed1977

[Genetic tolerance to alcohol in Drosophila: comparison of the effects of selection in D. melanogaster and D. simulans].

A strain of D. simulans and 3 strains of D. melanogaster having different initial levels of alcohol tolerance were submitted to increasing selection for at least 30 generations. In melanogaster, the relative efficiency of selection was inversely related to the initial level. In simulans, whose natural tolerance is particularly low, only a small increase was obtained. In all cases, tolerance increased progressively and could be considered as a quantitative character. These results are probably due to modifier genes of the alcohol dehydrogenase locus.

Alcohol Oxidoreductases↗
PubMed1977

Adaptive response due to changes in gene regulation: a study with Drosophila.

In spite of the critical role of the process of adaptation in evolution, there are few detailed studies of the genotypic and molecular basis of the process. Drosophila melanogaster flies selected for increased tolerance to ethanol exhibited higher levels of alcohol dehydrogenase (alcohol:NAD+ oxidoreductase; EC 1.1.1.1) activity than unselected controls. A series of tests (electrophoresis, product inhibition, temperature stability, pH optima, substrate specificity, and Michaelis constants) gave no evidence of structural differences in the enzyme of the selected and the control flies. However, quantitative immunological assays showed that the selected flies contained significantly higher amounts of alcohol dehydrogenase. Adaptation of the selected flies to higher alcohol tolerance has most likely taken place by changes not in the structural gene locus coding for the enzyme, but by regulatory changes affecting the amount of gene product.

Adaptation, Biological↗
PubMed1977

Photic and pentylenetetrazol-induced seizure susceptibility in Macaca mulatta.

Ninety-five out of 100 male Macaca mulatta of varying ages from a restricted habitat in N. India showed no abnormal seizure susceptibility or EEG response to photic stimulation and no electro-clinical features of epilepsy after pentylenetetrazol, 40 mg/kg sc.c. Autopsy studies on the remaining five monkeys with increased seizure proneness revealed depressed skull fractures with cortical trauma in four and a neoplasm in one. Presumably, these factors were responsible for the lowered seizure susceptibility to photic stimulation and pentylenetetrazol activation.

Animals↗