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Biomedical subjects

D H Marshall

Publications and source records attributed to D H Marshall.

At least 73 records · Page 4Linked to original sources
PubMed1977

Seasonal variations in the composition of urine from normal subjects: a longitudinal study.

The volume, pH and composition of 24-h urine samples, collected by 13 healthy male adults, were followed over a period of one year. Significant and systematic variations in urine pH, calcium, phosphate, oxalate, uric acid, potassium and magnesium were observed. A significant but non-sinusoidal variation in sodium excretion was found but there were no significant changes in urinary volume, creatinine or hydroxyproline. Many of the observed changes could be attributed to variations in the pattern of food consumption throughout the year but calcium, phosphate and oxalate were exceptions in that seasonal variations in these parameters appeared to be due to the effects of sunlight (or vitamin D) rather than to the diet.

Adult↗
PubMed1977

The effect of 1alpha-hydroxyvitamin D3 with and without oestrogens on calcium balance in post-menopausal women.

Balance studies were performed in thirty-three post-menopausal women (all but five having vertebral crush fractures or femoral neck fractures) in the basal state and on treatment with 1alpha-hydroxyvitamin D3 and/or oestrogenic hormones. The results suggest that the effectiveness of oestrogen therapy is limited by calcium malabsorption and the effectiveness of 1alpha-hydroxyvitamin D3 is limited by oestrogen deficiency. The best results were obtained with combined therapy to remedy what appears to be two distinct deficiencies. To minimize the risks of hypercalcaemia and the possible risks of hormone therapy, we suggest that the treatment of choice in post-menopausal osteoporosis may be 1alpha-hydroxyvitamin D3 1microgram daily and ethinyloestrodiol 25 microgram daily for 3 weeks in every 4. Patients on a low dietary intake of calcium should probably be given calcium supplements. With this regimen, it should not be necessary to screen patients initially for calcium malabsorption or oestrogen deficiency because the majority of patients present with a combination of the two factors.

Calcium↗
PubMed1977

The prevention and management of post-menopausal osteoporosis.

In 6 groups of peri- and post-menopausal women, there was an inverse relation between the urinary sediment smear maturation value and the fasting urinary hydroxyproline/creatinine ratio. Administration of ethinyloestradiol and Progynova both reduced urinary hydroxyproline into the pre-menopausal range, the fall being proportional to the starting value. Oestrogen therapy also produced a significant fall in plasma ionised calcium. In a prospective trial, oestrogen therapy prevented post-menopausal bone loss but calcium therapy was less effective. It is suggested that a high fasting urinary hydroxyproline/creatinine ratio might be taken as an indication for oestrogen therapy in post-menopausal women. In established post-menopausal osteoporosis, pre-disposing risk factors appear to be low calcium intake, malabsorption of calcium and low oestrogen status. These patients appear to represent the fast bone-losers in the post-menopausal population. The accelerated bone loss can be wholly or partially corrected by hormone replacement therapy and by calcium supplements given to those with normal absorption only. These therapies also prevent loss of height due to further crush fractures. The malabsorption of calcium is very resistant to vitamin D therapy but responds to 1alpha-OHD3. Balance data suggest that the most effective therapy may be a combination of 1alpha-OHD3 with oestrogen.

Aged↗
PubMed1976

Saturation-inhibition index as a measure of the risk of calcium oxalate stone formation in the urinary tract.

Studies were carried out on multiple urine samples from eight patients with recurrent idiopathic calcium oxalate stone formation and eight normal persons to define an index of the risk of forming calcium oxalate stones. Under the same conditions of dietary and fluid intake the urine samples of the patients with stone formation were more supersaturated with calcium oxalate (P less than 0.001) and had lower concentrations of protective inhibitors of crystallization (P less than 0.001) than those of the controls. However, the best separation between the groups was defined by a discriminant line relating inhibitory activity and urine saturation. A measure of the risk of forming large crystals, the saturation-inhibition index, was defined as the distance of each urine from the discriminant line. The patients with stone formation had a significantly higher mean saturation-inhibition index than the controls (P less than 0.001). Both the percentage of large calcium oxalate crystals excreted (P less than 0.001) and the stone episode rate (P less than 0.005) were significantly correlated with the saturation-inhibition index.

Calcium↗
PubMed1974

Seasonal variations in urinary excretion of calcium.

A retrospective study over a three-year period has shown a noticeable seasonal variation in the daily urinary excretion of calcium in healthy men, healthy women, and men prone to form stones. This reached a maximum in July or August and a minimum in December or January in all three groups. For any given month the stone formers had higher urinary calcium values than healthy men, who, in turn, had higher values than healthy women.

Adult↗