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Biomedical subjects

G Roberts

Publications and source records attributed to G Roberts.

At least 217 records · Page 12Linked to original sources

Starch and talc emboli in drug addicts' lungs.

The lungs of eight drug addicts dying as a consequence of their habit have been examined. All showed the presence of small amounts of talc emboli and five the presence of starch emboli. Talc was invariably associated with a marked foreign body reaction which was insignificant in association with starch. Animal experiments showed very rapid (90% in 24 hours) removal of maize starch emboli; such rapid removal in man would explain the lack of a foreign body response. Quantitation of the amount of starch present in lungs from two of the cases gave values of 1.5 and 5.2 g. The higher amount could have been a contributory factor in the sudden death of the addict. The amounts of talc seen were not sufficient to be of clinical significance.

Acetaminophen↗

Uterine hypertonus during labour induced by prostaglandins.

Labour was induced successfully at or near term in 34 out of 35 cases by combined amniotomy and intravenous infusion of either prostaglandins F(2)alpha, E(2), or E(1). Of particular importance is the finding of hypertonus in 4 of the 18 cases induced with prostaglandin E(2).

Adolescent↗

The effect of healing on bile reflux in gastric ulcer.

Bile reflux has been studied by serial estimations of bile acid concentrations in the stomach before and after a liquid meal. Thirteen normal subjects and 38 patients with gastric ulcer were examined. Thirty-one in the ulcer group had the test repeated once or twice within two months of the initial test to observe any change in reflux associated with healing. Patients with gastric ulcer had significantly higher concentrations of bile acids than normal subjects, both before and after the meal, although there was an overlap between the groups. In patients with an ulcer which healed or showed some healing over two months, no consistent change in reflux was found.

Bile↗

Absence of antidiuresis during administration of prostaglandin F2 alpha.

Water diuresis was induced in six patients in mid-pregnancy. Three were then given oxytocin and the remainder prostaglandin F(2)alpha (PGF(2)alpha), both drugs being infused intravenously in doses used to induce labour at term. Pronounced antidiuresis occurred with oxytocin, whereas PGF(2)alpha showed no such effect. The probable absence of any risk of water intoxication when using PGF(2)alpha in inducing labour may be of particular value when maternal pre-eclampsia or renal disease is present.

Abortion, Legal↗

Improved methods for reducing calcium and magnesium concentrations in tissue culture medium: application to studies of lymphoblast proliferation in vitro.

We have compared several methods for reducing calcium and magnesium concentrations in tissue culture medium, with the objective of producing selective deficiency effects on the growth of mouse (L5178Y) and human (P1R) lymphoblasts. In experiments in which calcium- and magnesium- "free" McCoy's medium was supplemented with 15% horse or fetal calf serum, enough calcium and magnesium was provided by serum to support normal lymphoblast growth rate. Either dialysis or chelating-resin treatment of horse or fetal calf serum reduced calcium and magnesium contents approximately 100-fold. Use of dialyzed sera resulted in reduced growth rate, although in most cases the reduction in growth could be attributed to other effects of dialysis on serum, inasmuch as growth in those experiments was not restored to normal by the addition of calcium and magnesium to the medium. In contrast, the reduction of lymphoblast growth rate that occurred when resin-treated serum was used was always attributable to removal of calcium and magnesium, as normal growth always occurred in cultures to which calcium and magnesium were added. To demostrate a growth-inhibiting effect on either mouse or human lymphoblasts by severe reduction of either calcium or magnesium in the presence of normal amounts of the alternative cation, it was necessary to (a) expose McCoy's Ca-Mg-"free" medium to chelating-resin to reduce further the residual cation concentrations; (b) wash cells from stock cultures in a medium devoid of calcium and magnesium prior to inoculation into experimental cultures; (c) reduce the proportion of serum in the final medium from 15 to 5%; and (d) add 100 muM EGTA to cultures. Under these conditions, growth of both cell types was completely abolished in the presence of normal magnesium but in the absence of added calcium, and markedly reduced in the presence of normal calcium but in the absence of magnesium. These modifications did not compromise growth in cultures containing normal concentrations of both ions.

Animals↗