In order to find out whether the sympatho-adrenal system is activated in relation to heat stroke, plasma levels of norepinephrine (NE) and epinephrine (E) were measured using high pressure liquid chromatography in seven patients with heat stroke. The mean NE +/- SD levels on admission and six hours afterwards were 1397 +/- 317 and 717 +/- 239 pg/ml, respectively. The corresponding values for E were 257 +/- 55 and 32 +/- 15 pg/ml. The levels of both NE and E on admission were considerably higher than those of the controls: 328 +/- 62 and 88 +/- 16 pg/ml (12 normal subjects). This increase in both NE and E indicates activation of the sympatho-adrenal system in patients with heat stroke. The alpha-mediated effect of catecholamines may be important in impairing heat dissipation and thus may contribute to the pathogenesis of heat stroke.

Rifampicin(R) is a potent enzyme inducer which is now widely used to treat many conditions. We have investigated its effect on adrenal function tests in 18 adults with tuberculosis on rifampicin (R) and isoniazid (INH) as in-patients. Midnight cortisol was above 250 nmol/l in 11 patients with a mean +/- (SD) of 340 +/- 193 nmol/l. The morning serum cortisol following 1 and 4 mg dexamethasone overnight was abnormal in 88.9 per cent and 83.3 per cent respectively. The respective mean values +/- (SD) were 350 +/- 179 and 336 +/- 279 nmol/l. The mean 24-hour urinary free cortisol +/- SD was 513 +/- 375 nmol and was above normal in 6 (33.3 per cent) patients. These results show that midnight cortisol, dexamethasone suppression tests and 24-hour urinary free cortisol are misleading in patients with tuberculosis on (R) and should not be employed for investigating such patients for Cushing's syndrome.

Neutropenia is a potentially serious complication of parenteral benzylpenicillin administration. It is thought to occur more frequently in patients receiving infusions of stored penicillin solutions. We report three cases of neutropenia produced after bolus injections of freshly prepared benzylpenicillin. Twenty-five other cases were reviewed from the literature and the data summarized.