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Biomedical subjects

R Lindsay

Publications and source records attributed to R Lindsay.

At least 235 records · Page 13Linked to original sources
PubMed1977

The effect of endogenous oestrogen on plasma and urinary calcium and phosphate in oophorectomized women.

Using a specific radioimmunoassay, significant levels of plasma oestradiol can be detected in the blood of oophorectomized women. In these women the plasma concentration of oestradiol correlates positively with body fat content. Low circulating concentrations of oestradiol are associated with increased values for serum phosphate and alkaline phosphatase, but no significant change in serum calcium. The fasting urinary calcium creatinine ratio is inversely related to circulating plasma oestradiol concentration which also correlates, in a more complex way, with the renal threshold for phosphate (TmPO4/GFR). It is suggested that oestrogen production may be an important factor in determining bone loss in postmenopausal women.

Alkaline Phosphatase↗
PubMed1977

Vascular complications of long-term oestrogen therapy.

Long-term low dose oestrogen therapy has a protective effect on bone mineral content in the post-menopausal or castrated female. As yet the only obvious clinical side effect of such therapy has been transient leg muscle cramps. Several biochemical side effects could be observed. Low dose mestranol caused a persistent elevation of factor VII and a dose-dependent increase in both factors VII and X was observed using oestriol hemisuccinate. Such effects are more likely to be dose-related than related to the type of oestrogen prescribed. Effects of oestrogens on lipids, and cholesterol in particular, may be dose-related also. Changes in blood pressure in post-menopausal women are more likely to be related to obesity than to oestrogen treatment which would seem to have a protective effect against weight increase. No marked changes in the mean risk score for ischaemic heart disease could be detected during oestrogen treatment.

Blood Coagulation Disorders↗
PubMed1977

Hemobilia associated with a traumatic arteriovenous fistula.

Although there have been many reports of hemobilia, its association with an arteriovenous fistula within the liver is extremely rare, only two cases having been reported in the world literature. The authors describe a third case in which a gunshot injury to the liver of a 19-year-old man resulted in the development of hemobilia demonstrated radiologically to be associated with an arteriovenous fistula. The condition was successfully managed by ligation of the proximal hepatic artery.

Adult↗
PubMed1976

Long-term prevention of postmenopausal osteoporosis by oestrogen. Evidence for an increased bone mass after delayed onset of oestrogen treatment.

Treatment of 63 oophorectomised women with oestrogen for five years prevented the reduction in bone mineral content observed in 57 women treated with a placebo preparation. When onset of therapy was delayed for three to six years there was a highly significant increase in bone mineral content mainly during the first three years of treatment. During the next two years there was no further increase in bone mineral, while the placebo-treated groups continued to lose bone at about 1% per annum. In association with the changes in bone mass, the expected biochemical effects of oestrogen therapy also persisted for at least three years, and were compatible with a prolonged increase in parathyroid activity but a reduction in bone turnover.

Adult↗
PubMed1976

Rat hepatic sodium plus potassium ion-dependent adenosine triphosphatase after treatment with digoxin and thyroxine.

1. The effect of treating rats with digoxin and thyroxine for 45 days has been studied. 2. Animals fed with digoxin gained significantly more weight than the control animals. 3. Treatment with digoxin, thyroxine or both produced a similar significant increase in the amount of Na+ + K+ -dependent adenosine triphosphatase in liver without an additive effect. 4. It is suggested that digoxin resistance in thyrotoxicosis may be related to this similarity in action.

Adenosine Triphosphatases↗
PubMed1976

A study of changes in whole-body calcium, phosphorus, sodium and nitrogen by neutron activation analysis in vivo in rats on a calcium-deficient diet.

1. A method of measuring changes in the total body content of calcium, phosphorus, nitrogen and sodium in rats by activation analysis in vivo is described. 2. The change in the body content of the elements has been measured in rats on a calcium-deficient diet and in control animals, the body nitrogen being used to represent lean body mass for normalization. 3. There were siginificant differences in Ca/N and P/N but not in Ca/P ratios between the animals on a deficient diet and control animals at the end of the dietary period.

Animals↗
PubMed1976

Properties of the calcium-activated adenosine tri-phosphatase from L-cell membranes.

Preparation of surface membranes from mouse L-cells using a technique previously described in the literature [Perdue & Sneider, 1970] allowed characterization of a Ca-activated ATPase apparently separate from the mitochondrial ATPase also dependent on calcium. This enzyme is associated with the Na-K-ATPase, a marker for surface membranes, and not wilth alkaline phosphatase, a mitochondrial enzyme. In temperature sensitivity, pH dependence and inhibition by ethacrynic acid, the partially purified enzyme has properties similar to those previously described for active calcium efflux from these cells. For maximal activity of the enzyme system magnesium and sodium are required, although the calcium transport from whole cells was apparently independent of both. Adenosine triphosphate only was metabolized by the enzyme system, whereas CTP could be utilized for calcium transport from 'ghost' cells, probably as a result of intracellular conversion to ATP. It is suggested that the active calcium transport from cultured L-cells is closely linked to the calcium dependent ATPase, and that the method of calcium extrusion is similar to that described for red blood cells.

Adenosine Triphosphatases↗
PubMed1976

Changes in plasma and urine magnesium following subcutaneous insulin.

In 7 of 13 patients given subcutaneous insulin as part of the assessment of their endocrinological status, serum magnesium levels fell below the lower limit of the normal range for the laboratory 1 to 2 hours after insulin administration. This relative hypomagnesaemia was not accompanied by any change in the red cell magnesium concentration, and did not bear a close relationship to the degree of hypoglycaemia developed. During the 2 1/2 hour period following insulin therapy there was renal conservation of magnesium ion.

Humans↗
PubMed1976

Prevention of bone loss following oophorectomy in premenopausal women: a retrospective assessment of the effects of oophorectomy and a prospective controlled trial of the effects of mestranol therapy.

Prospective studies of bone mass in women following oophorectomy for benign conditions were done by the double-blind technique. Skeletal response to treatment was measured by photon absorption densitometry. Untreated patients were found to lose bone mass rapidly during the first two years after oophorectomy. When estrogen replacement was started within two months of oophorectomy, it was found to be effective in preventing subsequent bone tissue loss. Three years following oophorectomy, untreated women who had already lost bone tissue, and who were then started on estrogen replacement, showed a highly significant increase in their bone mass. The women in whom this treatment was delayed for six years did not respond. No untoward effects were noted in these women, perhaps, in part, because they had undergone hysterectomy. Long-term effects of this treatment are now being evaluated.

Adult↗