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Biomedical subjects

M Davies

Publications and source records attributed to M Davies.

At least 541 records · Page 30Linked to original sources
PubMed1976

Metabolic fate of administered 1,25-dihydroxycholecalciferol in controls and in patients with hypoparathyroidism.

In four healthy controls and three patients with hypoparathyroidism serum-1,25-dihydroxycholecalciferol (1,25-D.H.C.C.) concentrations, after oral or intravenous administration, declined biphasically with a rapid-phase half-time of about 14 hours. Repeated oral doses of 1 mug 1,25-D.H.C.C. (2-4 nmol) produced serum concentrations well below the assayed normal range but were nevertheless effective in raising serum-calcium. It is suggested that orally administered 1,25-D.H.C.C. acts directly on the intestinal mucosal-cell nucleus to promote calcium absorption. 1,25-D.H.C.C. is more rapidly eliminated from the body than vitamin D, and it is predicted that any hypercalcaemia caused by 1,25-D.H.C.C. therapy should be of relatively short duration.

Administration, Oral↗
PubMed1976

Behavioral and social effects of heroin self-administration and withdrawal.

Behavioral and social reactions to intravenously administered heroin were studied during a 33-day experimental addiction cycle. Three groups of four subject volunteers were allowed to self-administer heroin for a ten-day period as part of a longer study of oplate antagonists. Data relevant to sleep patterns, energy expenditure, social interaction, and other observable behaviors were collected during hourly observations. Comparison of behavioral differences before and after drug administration indicated few significant acute reactions. Reactions to long-term heroin self-administration were most pronounced in the areas of sleep behavior and social interaction. Subjects tended to sleep less, especially during the initial period of acquisition, and to withdraw more from social contact. No changes were noted in energy expenditure during waking hours. The results were interpreted in terms of physiological tolerance, central nervous system arousal, and sleep deprivation.

Adult↗
PubMed1976

How many tastes are there for low concentration "sweet" and "sour" stimuli? - Threshold implications.

Ascending series of solutions of sucrose, glucose, and citric acid were tasted and detection and recognition thresholds were noted; subjects were also required to determine the number of taste sensations that occurred and their sequence of occurrence. It was found that subjects varied in their reports of the number of taste changes and hence potential criteria for detection and recognition. Even among those subjects who reported the same number of criteria there was little consistency as to which were actually chosen for detection and recognition. Some subjects even used an intensity change rather than a quality change to signal a threshold. They criterion can thus be seen to be a potential variable in threshold measurement, and criterion-free measures of sensitivity are recommended. Taste quality descriptions were also studied and a high proportion of novel descriptions was noted; it was hypothesised that this was due to the fact that subjects were not primed with traditional descriptive terms during the instructions.

Adolescent↗
PubMed1976

Studies on the effect of salicylic acid on normal skin.

This investigation was prompted by our ignorance of the way in which salicyclic acid aids desquamation. Salicyclic acid in aqueous cream or white soft paraffin and in concentrations of 2-12% was applied to normal skin of twenty-three subjects while the vehicle alone was applied to the contralateral sites. Biopsies and skin surface biopsies were taken from the test and control sites after 1 week. Histological examination showed that there was less horny layer on the test specimens but that there were no qualitative or quantitative differences in the structure of the viable epidermis. Portions of the biopsies were incubated in the presence of tritiated precursor compounds and subsequent autoradiographic examination showed no difference in the incorporation of thymidine, cytidine or histidine between test and control preparations. Scanning electron microscopy of skin surface biopsies showed some changes in all specimens--presumably due to hydration--but also showed striking differences between test and control sites and were especially marked with higher concentrations of salicylic acid. It is suggested that salicylic acid causes desquamation by dissolution of intercellular cement material.

Autoradiography↗
PubMed1976

Treatment of hypoparathyroidism with 1,25-dihydroxycholecalciferol.

Five patients with hypoparathyroidism (three post thyroidectomy and two idiopathic) were treated with synthetic 1,25-dihydroxycholecalciferol (1,25-(OH)2-D3) for up to 6 months. In each case daily oral administration of 1 microgram 1,25-(OH)2-D3, either alone or with additional calcium, raised ther serum calcium into the normal range. The serum phosphorus and the renal tubular reabsorption of phosphorus fell during treatment. None of these patients developed hypercalcaemia and no other complications of treatment have been recorded. 1,25-(OH)2D3 seems to represent a significant improvement over conventional methods for treating hypoparathyroidism.

Adult↗
PubMed1975

"That wummin".

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England↗
PubMed1975

Interactions of carbenicillin and ticarcillin with gentamicin.

The in vitro inactivation of gentamicin by carbenicillin and a new semisynthetic penicillin, ticarcillin (BRL 2288), has been demonstrated. Gentamicin half-lives have been studied in eight patients with end-stage renal failure, and a 25 to 74% reduction in half-life has resulted from the concomitant administration of therapeutic doses of carbenicillin and ticarcillin.

Carbenicillin↗
PubMed1975

Influence of the length of Heineke-Mikulicz pyloroplasty on the area of gastric outlet.

Using agar casts of human post-mortem stomachs we have shown that (1) A 4-cm Heineke-Mikulicz (H-M) pyloroplasty increases the diameter of the narrowest area of the pylorus in every case. (2) Further increase to an 8-cm pyloroplasty leads to a further comparable increase in the size of the outlet. (3) The distortion caused by H-M pyloroplasty does not reduce the mean cross-sectioned area of the pyloric canal. (4) The narrowest area of the outlet appears to remain at the pylorus. These findings and their significance in gastric emptying are briefly discussed.

Digestion↗