Hypokalemia alters sex hormone and gonadotropin levels: evidence that FSH may be required for luteinization.

Hypokalemia produced different effects on steroid sex hormone concentrations in plasma and ovary in the mouse. Estradiol levels were slightly increased, whereas circulating progesterone was markedly decreased in all estrous periods. The preovulatory surge of gonadotropins and the secondary surge of follicle-stimulating hormone (FSH) at estrus were also decreased, but basal levels of both gonadotropins were unaffected. Supplementation with luteinizing hormone (LH), FSH, or gonadotropin-releasing hormone (GnRH) at proestrus rapidly normalized plasma and ovarian progesterone levels at this stage of the estrous cycle. Plasma progesterone levels at diestrus were restored only by combined treatment, at the periovulatory stage, with LH and FSH or GnRH but not by LH or FSH alone. The results demonstrate a lack of steroidogenic activity in the corpus luteum of the potassium-deficient mice and, furthermore, that FSH plays an important role in luteinization in the hypokalemic mice. We conclude that alteration of the transcellular potassium gradient may affect the regulation of the periovulatory surge of gonadotropins and progesterone secretion, probably by altering the release of GnRH from the hypothalamus. In addition, the results suggest that FSH may play a certain role as a luteotropic hormone in mice.

Neurological manifestation of arterial gas embolism following standard altitude chamber flight: a case report.

In the course of a decompression at flight level 280 (28,000 ft) in an altitude chamber flight, a 45-yr-old cabin air traffic controller developed sudden numbness in his left upper and lower extremities and, soon after, complete paralysis in the left side, dysarthria and left facial palsy. A presumptive diagnosis of arterial gas embolism (AGE) was made and hyperbaric oxygen therapy (HBO) was given after airevac of the patient to the closest compression facility. Complete resolution of the symptoms was obtained after treatment Table VI-A (extended), plus 3 consecutive HBO treatments (90 min of Oxygen at 2.0 ATA). AGE is a rare event in the course of regular altitude chamber flight and diagnosis should be done in the context of the barometric pressure changes and an acute cerebral vascular injury. Risk factors and follow-up diagnostic procedures are discussed.

Vincristine effect on methotrexate cerebrospinal fluid concentration.

A 67-year-old man with malignant lymphoma, nodular, poorly differentiated lymphocytic type, developed meningeal lymphomatosis. Repeated high-dose methotrexate-citrovorum factor treatment (1 g/m2 in 24 hours) rendered the patient free of disease. The administration of vincristine at 23 hours consistently increased the concentration of methotrexate in the cerebrospinal fluid 2.5-fold above baseline values.