Biomedical subjects

D M Large

Publications and source records attributed to D M Large.

21 records · Page 2Linked to original sources

PubMed1981

Familial hypocalciuric hypercalcaemia and acute pancreatitis.

Four families with familial hypocalciuric hypercalcaemia were studied. The probands presented with abdominal pain, which in three was due to acute pancreatitis; in two the condition was life threatening. Serum concentrations of calcium, magnesium, phosphate, and immunoassayable parathyroid hormone, urinary calcium excretion, and the rate of renal tubular reabsorption of phosphate were measured; the findings were compared with results in 10 patients with primary hyperparathyroidism matched for serum calcium concentration to establish differences between the diseases. Familial hypocalciuric hypercalcaemia should be suspected in patients with hypercalcaemia in whom daily urinary calcium excretion is below 5 mmol (200 mg) provided renal insufficiency, vitamin D deficiency, and ingestion of drugs that reduce calcium excretion have been excluded. Most cases appear to run a benign course, but some may suffer considerable morbidity. Surgical treatment should be reserved for patients with severe complications, when all parathyroid tissue should be removed.

Acute Disease↗

PubMed1980

Twenty-four hour profiles of serum prolactin during male puberty with and without gynaecomastia.

Twenty-four hour profiles of circulating prolactin have been documented in eight boys with simple delayed puberty, eleven with gynaecomastia, three of whom were retested following its spontaneous resolution, and two normal adult men. Mean 24 h prolactin levels in four boys with delayed puberty and ten with gynaecomastia exceeded the mean levels for the two adult men. A sleep-associated rise in prolactin levels occurred at all stages of puberty irrespective of the presence or absence of gynaecomastia, and in some subjects peaks also occurred during the daytime. Boys with gynaecomastia had higher 24 h means levels of prolactin (P less than 0.05), higher daytime levels (P less than 0.05) and higher sleep-associated levels (P less than 0.05) than did control subjects. These were not related to the degree or duration of the gynaecomastia, but 24 h mean levels of prolactin and oestradiol were positively correlated. In one subject who had had transient galactorrhoea, high levels of circulating prolactin, oestrone and oestradiol fell following spontaneous resolution of the gynaecomastia. We believe that oestrogen: androgen imbalance during the daytime is the major cause of pubertal gynaecomastia, with hyperprolacinaemia (which may cause galactorrhoea) sometimes occurring as a response to relative hyperoestrogenaemia.

Adolescent↗

PubMed1979

Twenty-four hour profiles of circulating androgens and oestrogens in male puberty with and without gynaecomastia.

The possible mechanisms involved in the development of transient gynaecomastia during male puberty have been investigated by studying 24 h profiles of circulating androstenedione (Ao) and testosterone (T) and their oestrogen pairs oestrone (E1) and oestradiol(E2), in eight boys with simple delayed puberty, eleven boys with pubertal gynaecomastia (three of whom were re-tested after its spontaneous resolution), and two normal adult men. No differences were observed between the 24h T and Ao profiles of pubertal boys with or without gynaecomastia; we confirmed that the initial T rise was nocturnal, associated with sleep. Late in puberty daytime T levels also rise. A small rise in 24 h Ao was seen, but this was not closely related to the stage of puberty. The major new finding was that E2 and to a lesser extent E1 levels are high relative to T for prolonged periods of the afternoon and evening (when T levels are lowest) in male puberty. A frequent finding, seen only in boys with gynaecomastia and one who later developed it, was of elevated and markedly fluctuating levels of plasma E2, and an absolute increase in the area under the 24 h E2 profile and between the E2 and T profiles. These fell towards normal in three boys who were re-tested after resolution of gynaecomastia. In a minority of subjects T and E2 were quite closely correlated, suggesting that in them rapid aromatization of T was occurring within or outside the testis. We conclude that normal male puberty is associated with relative oestrogen dominance particulary in the daytime. In boys with gynaecomastia there is in addition often an absolute elevation of E2 with or without E1, while 24 h T levels are submaximal. Normal men probably require sustained adult circulating T levels to prevent their oestrogens from stimulating breast development.

Adolescent↗