5-HT receptor blockade in the posterior amygdala elicits feeding in female rats.

Previous work suggests that feeding following intraventricular (i.v.t.) injections of the serotonin (5-HT)(1/2/7) antagonist metergoline (MET) is not localized to the hypothalamus. Since lesions of the posterior basolateral amygdala (pBLA) block feeding following systemic 5-HT1A agonist 8-hydroxy-2(di-n-propylamino)tetralin, the ability of intra-pBLA MET to elicit feeding was investigated. In two separate experiments, feeding of female rats was measured over 2 h following 0, 3, 10 and 30 nmol and 0, 0.03, 0.3 and 3 nmol MET (mol. wt. 403.5) injected bilaterally into each pBLA. All three doses used in Experiment 1 increased feeding over 2 h. In Experiment 2, feeding over the first hour was enhanced after the two highest doses. Since intra-pBLA MET elicits feeding comparable to that seen using much higher doses administered i.v.t. these data implicate the pBLA as an extra-hypothalamic site mediating the effects of 5-HT in feeding control.

In vitro synthesis of IgE by human peripheral blood leucocytes: V. Functional heterogeneity within the IgE-B-cell pool.

Fractionation of human peripheral blood leucocytes (PBL) B cells by differential sedimentation on a discontinuous Percoll gradient separates B cell subpopulations which vary markedly in rates of spontaneous IgE synthesis, often revealing the presence of active IgE secreting cells which are totally suppressed within unfractionated PBL B cell preparations. The production in vitro of IgE by separated B cell populations from the same individual may respond disparately to an identical population of autologous T cells and to pokeweed mitogen. Kinetic studies revealed major differences in both the rates of release of cell-associated IgE between these B cell populations, and their rates of de novo IgE synthesis. From a methodological viewpoint, the use of this B cell fractionation technique is demonstrated to improve greatly the efficiency of detection of T cell-responsive IgE producing B cells in peripheral blood from atopics, and from a mechanistic standpoint raises the possibility that B cell heterogeneity may modulate the functional expression of IgE-regulatory T cells signals.

Congenital renal salt-losing syndrome and failure to thrive in infancy.

An infant with congenital renal salt-losing syndrome is reported. The importance of recognizing this rare disorder is emphasized because early detection, and treatment with sodium supplementation, results in marked growth improvement and may prevent volume depletion, electrolyte disturbance, and cardiovascular collapse. The clinical features and biochemical abnormalities seen in the congenital renal salt-losing syndrome are described. In this condition, natriuresis occurs in the face of normal renal and adrenal function and, as the child gets older, spontaneous resolution occurs. Other causes of hyponatraemia in infancy are discussed.

In vitro synthesis of IgE by human peripheral blood leucocytes. IV. Longitudinal study of regulatory T-cell activity in atopics.

The assessment of IgE production in cultures of T- and B-cells from peripheral blood is proving a useful tool to probe IgE immunoregulation in human atopics. The present study contrasts secretion and synthesis as indices of IgE production, and demonstrates that these measures yield comparable data upon the magnitude and direction of regulatory T-cell effects (help vs. suppression) in severe atopics. The majority of peripheral blood B-cell samples from the atopics in this study exhibited spontaneous IgE synthesis and secretion, and in vitro T-cell help and suppression were observed with equal frequency within the sample population. Repeated testing of individual atopics indicated that the direction of T-cell effects remained stable in some (but not all) atopics over periods as long as 3 years.

Treatment of asthma in children.

Children present a special problem, as the morbidity from asthma is high. Deaths occasionally occur. Evaluation of frequency and severity is mandatory in designing therapy. Adequate theophylline dosage is an effective bronchodilator. Nebulized salbutamol is a great advantage in moderate and moderately severe asthma because of its speed, ease of administration and effectiveness. Intravenous salbutamol is a considerable advance in the treatment of severe asthma. The use of nebulized Intal makes this drug available to the younger child for prophylaxis. Effective prophylactic long term management must include an environmental evaluation including detection of allergens and, if possible their removal, and the evaluation of physical pulmonary trigger factors and attention to emotional physical health.

Effect of beta-adrenergic blockade, pertussis vaccine and Freund's adjuvant on reaginic antibody response in mice.

IgE synthesis has been reported to be inhibited by theophylline and dibutyryl cyclic adenosine monophosphate and increased by pertussis vaccine. This study was done to determine if chronic beta-adrenergic blockade affects IgE antibody production. 72 C57BL/10J mice were sensitized with egg albumin (EA, 125 microng). Groups included: (1) EA alone; (2) EA + complete Freund's adjuvant (FA); (3) EA + B. pertussis (8 X 10(9) organisms); (4) EA + propranolol (0.5 mg/kg) 3 times/day; (5) EA + FA + propranolol; (6) saline alone. Booster was given on day 49. Group 1, given EA alone, failed to develop any passive cutaneous anaphylaxis (PCA) antibodies even after booster, whereas the 72-hour PCA titers ranged from 1/64 to 1/256 for groups treated with propranolol and propranolol + FA, respectively. The results suggest that chronic beta-adrenergic blockade enhances IgE antibody formation.