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Biomedical subjects

J N Cumings

Publications and source records attributed to J N Cumings.

At least 19 recordsLinked to original sources
PubMed1972

5-Hydroxytryptamine levels and platelet aggregation responses in subjects with acute migraine headache.

Blood 5-hydroxytryptamine levels were reduced during migraine attacks in patients who had not taken any drugs but the aggregation responses to 5-hydroxytryptamine of the blood platelets from these patients were similar to responses of platelets from migrainous subjects between attacks. This confirms earlier findings that a permanent difference exists in the behaviour of platelets from migrainous subjects. Blood 5-hydroxytryptamine levels were reduced during migraine attacks in patients who had taken ergotamine. The aggregation responses of platelets taken from migrainous patients on ergotamine both during and between attacks were inhibited, which is in agreement with results previously found for aggregation responses following the in vitro pre-incubation of control platelets with ergotamine. Blood 5-hydroxytryptamine levels were maintained during migraine attacks in patients who had taken analgesics and there was no reduction in the aggregation responses of their platelets.

Analgesics↗
PubMed1972

A case of G M2 gangliosidosis of late onset.

A case of G(M2)-gangliosidosis commencing by the age of 5 years is described, in which hyperacusis, dementia, and fits were prominent clinical features. In addition to the typical ganglioside pattern on thin layer chromatography and the presence of membranous bodies in electron microscopic studies and characteristic histology and histochemistry, there was biochemical evidence of a gross reduction in heat-labile hexosaminidase activity in white blood cells and brain. A younger unaffected sibling showed the same enzyme defect in white blood cells.

Age Factors↗
PubMed1971

Effects of methysergide on platelets incubated with reserpine.

1. Platelets were incubated with methysergide and related compounds (2-bromo lysergic acid (BOL), ergotamine and methyl ergotamine) together with reserpine.2. Methysergide inhibited the normal aggregation response of platelets to 5-hydroxytryptamine (5HT) but did not affect the reduction in the 5HT content caused by reserpine, or the uptake of 5HT by the platelets.3. BOL, ergotamine and methyl ergotamine behaved similarly. Methysergide had greater anti5HT potency than BOL, and methyl ergotamine had greater potency than ergotamine.4. The use of platelets as a model for synaptic preparations is discussed.5. The role of 5HT receptor sites on the platelet membrane and the significance of the results for migraine patients treated with methysergide are discussed.

Blood Platelets↗
PubMed1971

An assessment of platelet aggregation induced by 5-hydroxytryptamine.

A method of expressing platelet aggregation response after incubation relative to the response before incubation has been used in preference to using direct measurements, and some reasons are given for this choice. The effect of pre-incubating human platelets with reserpine has been compared with the effect of pre-incubation with 5-hydroxytryptamine (5HT). Reserpine inhibited 5HT-induced aggregation more slowly than 5HT and on this basis their actions could be distinguished. It was found that the aggregation response of human platelets to 5HT without pre-incubation (R) is inversely proportional to the natural 5HT content of whole blood, and an explanation has been suggested.A decrease in the aggregation response of human platelets to 5HT without pre-incubation (R) with increasing age has been noted, and is commented upon with reference to the release of amines from blood platelets. Platelets in plasma obtained from control subjects and incubated with methysergide and from migrainous patients taking methysergide both have reduced aggregation responses to 5HT. Platelets incubated with clonidine (St155) do not have reduced aggregation responses. A potentiating effect was noted after 20 minutes' incubation, but platelets from migraine patients taking St155 behaved normally. Tyramine affected the response of platelets to 5HT, giving results similar to those reported for reserpine. The differences between the aggregation responses to 5HT of platelets from migraine patients and normal control subjects are discussed.

Adult↗
PubMed1970

Biochemical studies in Nevin-Jones syndrome.

The lipid profiles of the brain in four cases of Nevin-Jones syndrome are described. A loss of phosphatidyl ethanolamine was found in both white matter and cortex in two cases as well as a more general loss of lipids in the cortex in one patient; there was a normal cerebrosidesulphatide ratio in myelin. These findings indicate a general loss of myelin over a period of time. The distribution of fatty acids in cerebrosides and sulphatides show a slight reduction in nervonic acid (24:1). The findings support the view that a secondary demyelination is present.

Brain Diseases↗