Cocaine, pregnancy, and postpartum intracerebral hemorrhage

An increase in cocaine abuse by pregnant women has been associated with a range of maternal/fetal cardiovascular complications. Intracerebral hemorrhage has been reported as a cocaine-related complication, but has not previously been associated with pregnancy. We report a case of cocaine-associated intracerebral hemorrhage in the postpartum period which complicated the differential diagnosis and management of hypertension and seizures.

Bone density and reproductive hormones in patients with neuroleptic-induced hyperprolactinemia

To study the prevalence of osteoporosis and hyperandrogenism in neuroleptic-induced hyperprolactinemia, the authors evaluated 10 patients. Three were amenorrheic, while seven had oligomenorrhea. Nine patients had galactorrhea. The Ferriman-Gallway hirsutism score was 12 +/- 2. Vaginal smear maturation value was 53 +/- 8. Bone density, measured by dual photon absorptionometry in the spine, femoral neck, Ward's triangle, and trochanteric region, was 98 +/- 1.5, 92.7 +/- 3, 88.5 +/- 4.2, and 92.6 +/- 3.3 percentile of controls matched for age, sex, weight, and ethnicity, respectively. Serum prolactin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), dehydroepiandrosterone sulfate (DHEAS), total testosterone, and free testosterone were 82 +/- 10 ng/ml, 8.5 +/- 1.1 mIU/ml, 11.1 +/- 2.6 mIU/ml, 4695 +/- 594 ng/ml, 90 +/- 17 ng%, and 2.36% +/- 0.3%, respectively. Serum thyroid-stimulating hormone (TSH) and free thyroxine index were normal. Bone density strongly correlated with vaginal maturation value (r = 0.904, P less than 0.01). It is concluded that (1) neuroleptic-induced hyperprolactinemia is associated with hirsutism and androgen excess primarily of adrenal origin and (2) a subset of these patients is at an increased risk of developing osteoporosis. It may be possible to identify patients at risk of osteoporosis by examining vaginal smears for maturation value. Early detection and management are imperative in this group of patients.

Inhibitory effects of hypermagnesemia on the renal action of parathyroid hormone

Available evidence indicates that serum magnesium (Mg++) levels influence the secretion rate of parathyroid hormone (PTH). Whether serum Mg++ concentrations also modify the action of PTH on its target organs has not been definitively established. The present experiments were designed to study this possibility. The effect of infusing PTH on the urinary excretion of cyclic AMP (cAMP) and PO4= was examined in five normal dogs at two different levels of serum Mg++. At normal serum Mg++ concentrations (1.89 +/- 0.14 mg/100 ml), PTH infusion increased cAMP excretion from 1.76 +/- 0.27 to 4.87 +/- 1.00 nmol/min and fractional PO4= excretion (FEPO4) from 1.58 +/- 0.36% to 23.1 +/- 2.17%. When an identical amount of PTH was given to the same dogs at a serum Mg++ of 4.36 +/- 0.20 mg/100 ml, FEPO4 increased to only 6.02+/-1.89% and cAMP from 1.31 +/- 0.23 to 1.89 +/- 0.39 nmol/min. Identical results were obtained in thyroparathyroidectomized hypermagnesemic dogs. Increased serum Mg++ levels had no effect on the phosphaturia produced by the infusion of dibutyryl cAMP to thyroparathyroidectomized dogs. In vitro studies using rat renal cortical slices revealed a progressive decrease in cAMP production in response to PTH as the Mg++ concentrations were increased in the incubation medium. The overall results indicate that hypermagnesemia inhibits the phosphaturic response to PTH by decreasing the renal production of cAMP. Plasma magnesium, therefore, may participate in a double feedback mechanism, not only controlling the release of PTH, but also altering the biological activity of the hormone at the level of the target organ.

On the mechanisms responsible for the phosphaturia of bicarbonate administration

Experiments were carried out in normal dogs to characterize the mechanisms by which sodium bicarbonate administration results in increased excretion of phosphate. Infusion of sodium bicarbonate alone increased fractional phosphate excretion from 0.8 to 29.3%. During bicarbonate administration, ionized calcium fell and mean parathyroid hormone values increased from 59.6 to 230.4 muleq/ml. In the same group of dogs, administration of sodium bicarbonate plus calcium prevented the fall in ionized calcium, and parathyroid hormone levels remained unchanged. In these dogs fractional phosphate excretion increased from 2.4 to only 4.9%. Similar results were obtained in thyroparathyroidectomized dogs receiving sodium bicarbonate. In these dogs fractional excretion of phosphate increased from 0.6 to 4.5%. Under all three experimental conditions no differences were observed in sodium or bicarbonate excretion or in urinary or plasma pH. Administration of hydrochloric acid, after phosphaturia had been induced by the infusion of bicarbonate, resulted in a decrease in plasma bicarbonate and an acid urine; however, the phosphaturia persisted even in the presence of an acid urine pH. In five thyroparathyroidectomized dogs infused with parathyroid hormone throughout, administration of identical amounts of sodium as either NaCl or NaHCO3 resulted in a similar degree of phosphaturia despite significant differences in urine pH. These experiments suggest that a rise in parathyroid hormone levels, resulting from a fall in ionized calcium, is the major mechanism by which bicarbonate administration produces phosphaturia. An increased natriuresis per nephron, as a consequence of extracellular fluid volume expansion, contributes to the phosphaturia. On the other hand, alkalinization of the urine does not play a significant role in the phosphaturia seen after bicarbonate administration.