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Biomedical subjects

W I Cranston

Publications and source records attributed to W I Cranston.

At least 37 records · Page 2Linked to original sources
PubMed1975

Is brain prostaglandin synthesis involved in responses to cold?

1. Experiments with rats have suggested that prostaglandin synthesis in the C.N.S. may mediate thermoregulatory reactions to cold. This possibility was investigated in cats using two types of experiment. 2. In one series of experiments, c.s.f. collected from the cisterna magna of conscious cats exposed to a cold and a hot environment was assayed for prostaglandin-like activity. During cold exposure there was a slight increase in activity which persisted after return to neutral ambient temperature. There was no correlation between prostaglandin-like activity and rectal temperature. During the heat exposure there was no demonstrable change in activity. 3. In the second series, conscious cats were exposed to cold conditions and given intravenous injections of salicylate, paracetamol, or indomethacin, all of which inhibit prostaglandin synthesis. Indomethacin salicylate nor paracetamol caused any significant change in rectal temperature. 4. The results do not support a role for C.N.S. prostaglandin synthesis in thermoregulatory reactions to cold in cats.

Acetaminophen↗
PubMed1975

A dissociation between fever and prostaglandin concentration in cerebrospinal fluid.

1. Sustained fever has been induced in conscious rabbits by I.V. injection and infusion of endogenous pyrogen. 2. Cerebrospinal fluid (e.s.f.) was sampled from the cisterna magna at hourly intervals. The concentration of prostaglandin increased in parallel with rectal temperature. The prostaglandin was identified as one of the E series. 3. When sodium salicylate (1-5 m-mole followed by a continuous infusion of 9 mumole/min) was started 1 hr before endogenous pyrogen, the febrile response to the pyrogen was not significantly diminished but no rise of prostaglandin concentration was detected in c.s.f. 4. This dissociation between fever and prostaglandin concentration means that changes in cisternal prostaglandin concentration cannot be accepted as evidence that prostaglandin mediates the febrile response.

Animals↗
PubMed1973

Spontaneous periodic hypothermia: diencephalic epilepsy.

The case of a patient with episodic hypothermia and profuse sweating believed to be due to diencephalic epilepsy is reported. Despite intensive investigations no other manifestations of hypothalamic dysfunction were found. Conventional antiepileptic drugs were without effect but the patient was successfully treated by total sympathectomy.

Atropa belladonna↗
PubMed1973

Ureteric stricture with analgesic nephropathy.

Three patients with analgesic nephropathy are reported who, in addition to the accepted features of this syndrome, had dilatation of one or both upper urinary tracts due to ureteric or periureteric fibrosis without intraluminal obstruction. We attribute this lesion to analgesic abuse and suggest that any patient with unexplained ureteric fibrosis should be questioned about analgesic consumption. This association also suggests a possible role for analgesic abuse in the pathogenesis of retroperitoneal fibrosis.

Adult↗
PubMed1972

Effects of intracerebral micro-injection of sodium salicylate on temperature regulation in the rabbit.

1. Symmetrical, bilateral micro-injections (10 mul.) of 6-30 mug sodium salicylate have been made into various parts of the brains of febrile and afebrile rabbits.2. In rabbits with fever induced by an intravenous infusion of endogenous pyrogen, micro-injections of sodium salicylate produced antipyresis when given into the preoptic hypothalamus and the mid-brain.3. In afebrile rabbits, micro-injections of sodium salicylate into these areas were without effect on temperature.4. The results suggest that at least part of the antipyretic effect of salicylates may be mediated by antagonizing the effects of endogenous pyrogen within these areas of the brain.

Animals↗
PubMed1972

Hypothalamic endogenous noradrenaline and thermoregulation in the cat and rabbit.

1. The imino-dibenzyl drugs, imipramine and desipramine, which inhibit the uptake by neurones of noradrenaline, were injected into the lateral cerebral ventricles of cats and rabbits: changes in body temperature resulted which were different for the two species, but nevertheless closely resembled those following intraventricular injection of relatively large quantities of exogenous noradrenaline.2. The endogenous noradrenaline content of the hypothalamus in both species was reduced by repeated injections into the lateral ventricle of the methyl ester of DL-alpha-methyl-p-tyrosine: in animals so treated the hypothalamic content of 5-hydroxytryptamine was not significantly changed.3. Noradrenaline-depleted animals showed significantly reduced responses to intraventricular imipramine and desipramine. The diminished responses were primarily due to reduction in endogenous noradrenaline.4. These observations indicate that endogenous noradrenaline, present in the hypothalamus, can influence body temperature in cats and rabbits.

Animals↗
PubMed1971

Influence of the duration of experimental fever on salicylate antipyresis in the rabbit.

1. Steady state fever has been produced in rabbits with a priming injection followed by a sustaining infusion of homologous plasma containing endogenous pyrogen (EP). This fever appears to last as long as the infusion continues.2. Intravenous salicylate given 1 h after the start of the EP infusion produced only a small antipyretic effect. The same dose of salicylate given 4 h after the start of an EP infusion resulted in rapid and progressive defervescence. Intermediate antipyretic responses were obtained when salicylate was administered intravenously 2 and 3 h after the start of an EP infusion.3. Less than 1% of the systemic dose, when injected into a lateral cerebral ventricle, produced a significantly smaller response at 1 h than at 4 h after the start of an EP infusion. At both these times the fall in temperature following the intraventricular salicylate injection was dose dependent, but the slope of the dose-response line was significantly steeper at 4 h than at 1 hour.4. It is suggested that salicylates produce their antipyretic effects by antagonizing the action of EP within the nervous system, and that the hypothalamic EP concentration falls during the course of an EP infusion.

Animals↗