Plasma membrane electron transport in frog blood vessels.

In an attempt to see if frog blood vessels possess a plasma membrane electron transport system, the postcaval vein and aorta isolated from Rana tigrina were tested for their ability to reduce ferricyanide, methylene blue, and 2,6- dichloroindophenol. While the dyes remained unchanged, ferricyanide was reduced to ferrocyanide. This reduction was resistant to inhibition by cyanide and azide. Heptane extraction or formalin fi xation of the tissues markedly reduced the capability to reduce ferricyanide. Denuded aortas retained only 30% of the activity of intact tissue. Our results indicate that the amphibian postcaval vein and aorta exhibit plasma membrane electron transport.

Effect of intracerebroventricular methotrexate on brain amines.

Intrathecal methotrexate in children with leukemia is known to cause seizures, dementia, leukoencephalopathy and cognitive dysfunction. To investigate the role of brain amines in cognitive dysfunction, male Wistar rats were given multiple intracerebroventricular injections of methotrexate. Our earlier studies in this regard revealed disruption of brain monoamines in hippocampus with severe cytotoxic effect on CA4 hippocampal neurons. Further extending this study, the levels of brain monoamines in frontal cortex, hypothalamus and brainstem were estimated by HPLC method and histopathological study of the frontal cortex. The concentration of all three-brain amine (norepinephrine, dopamine and serotonin) levels was reduced in 2 mg/kg dose of methotrexate in frontal cortex and brain stem. Hypothalamus did not show any significant change in brain monoamine levels. No structural changes in the frontal cortex neurons were observed. Disruption of brain monoamines has been proposed as a cause of brain dysfunction from this chemotherapy. The outcome of the study may have therapeutic implications in the management of childhood lymphoblastic leukemia.

Effects of p-chlorophenylalanine-induced depletion of brain serotonin on retrieval of appetitive and aversive memories.

This study examined whether depletion of central serotonin produces an improved retrieval of aversive memories in the same way as pre-exposure to inescapable footshocks, in rats. Animals conditioned in a T-maze with appetitive (10% sucrose) and aversive (2.0 mA footshock) events were given i.c.v. 24 hr later a single dose of p-chlorophenylalanine (p-CPA). (100, 200, 400 micrograms/rat) or drug vehicle. The retention performance and activity were assessed 48 hr after treatment with this depletor. While lower doses of p-CPA selectively reduced serotonin levels in striatum and anterior cortex, higher doses reduced both serotonin and norepinephrine levels in hippocampus in a dose-dependent fashion. The depletor however, failed to produce a differential improvement of aversive memory retrieval. On the contrary, p-CPA reduced the latency to enter both, previously shocked and appetitively reinforced, goalboxes. The enhanced traversing behaviour in T-maze, together with an increased central entry in the open field that observed in depleted groups, might suggest an anxiolytic activity of p-CPA.

Aetiologic factors in male infertility: clinical, microbiological and hormonal evaluation.

Seventy two infertile men were studied. History of small pox and mumps infection was noted in 4 and 3 patients respectively. Seven patients had varicocele (9.2%), and small atrophic testes were found in 9 (12.5%). Azoospermia was reported in 41 (58.3%) and oligospermia in 17 (23.6%), and 14 patients (19.4%) had normal sperm counts. Mycoplasma were grown from urethral swabs in 25 (35%) patients. Mean LH and FSH were elevated in azoospermics (p less than 0.001), E2-17B in oligospermics (p less than 0.001) and FSH in normospermic (p less than 0.01) patients. Hypergonadotropism suggestive of primary testicular failure was recorded in 43 (59.7%) patients. Hypogonadotropism was noted in 3 (4%) and hyperprolactinemia due to pituitary microadenoma induced infertility in only one patient. No aetiology could be determined in 11 (16%) patients.

Clinical profile and treatment outcome of diabetic ketoacidosis.

Data on 143 consecutive cases with diabetic ketoacidosis (DKA) seen during the past 6 years were analysed. The group included 60 males and 83 females, aged 8-70 years (21.5 +/- 4.2). Ninety five (66.5%) were known diabetics, while 48 had DKA as the first clinical presentation. The major recognised precipitating factors were infection in 42 patients (30%) and omission of insulin in 29 patients (20%). The approximate duration of DKA prior to hospital admission ranged from 4 to 96 hours. The range of biochemical alterations on admission were: blood glucose 9.7-51.1 mmol/l, (19 +/- 4.6), potassium 3.0 to 6.9 mmol/l (5.8 +/- 1.2), sodium 132 to 148 mmol/l (138 +/- 7.5), urea 4.67 to 26.17 mmol/l (11.3 +/- 2.9) and arterial pH 6.9 to 7.34. Therapy in all patients consisted of correction of fluid and electrolyte imbalance, insulin and suitable antibiotics. Forty three patients received low dose hourly insulin while others received it in the conventional schedule. Thirty four patients (23.7%) died. The parameters which could be related to mortality included (1) duration of DKA prior to admission, (2) severity of acidosis, and (3) severity of peripheral vascular insufficiency.

Effect of drugs used in pulmonary edema (frusemide and combination of etofylline and theophylline) on surfactant system of lung.

Pulmonary surfactant activity of healthy male albino rats was estimated in terms of the maximum and minimum surface tension values of alveolar washings and the phospholipid content of the extract. The results obtained in these (control) animals were compared with those in two groups of animals treated with therapeutic doses of frusemide and a combination of etofylline and theophylline. A significant increase in surfactant activity in terms of surface tension values and phospholipid content was observed with frusemide, whereas a significant increase in phospholipid content without a change in surface tension values was observed in the case of combination of etofylline and theophylline. These findings suggest that frusemide in addition to its diuretic action, increases the surfactant activity of lung. This might be another mechanism by which it provides relief in pulmonary edema patients. The study also indicates that phospholipid concentration need not always reflect surfactant activity of lung.

Lithium carbonate therapy for induction of euthyroid state in thyrotoxicosis. A preliminary study.

Lithium carbonate was tried in 27 patients with Graves' disease to induce euthyroid state. Each patient received 1200 mg of lithium carbonate in three divided doses. The study protocol included monthly monitoring of serum lithium, total serum T3, T4 and T3/T4 ratio, and a repeat radioactive iodine uptake (RAIU) at the end of three months. Twenty three patients completed the study. Of these, only 9 (39.1%) achieved euthyroid state, with a significant reduction in serum T3 and T4 but not in T3/T4 ratio and RAIU, suggesting a major effect of lithium on thyroid hormone release. No significant correlation was observed between serum lithium and circulating T3 and T4.