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Trypsin inhibitors (TI), tannins, and lectins appear to have a role in preventing chronic diseases in humans. The genetic variability of these traits in common bean needs to be ascertained in order to increase levels through breeding. The variability of TI, tannin, and lectins was determined in five bean cultivars grown at five locations in Mexico. TI and tannins contents in colored beans that belong to the Jalisco race were higher (11.1-11.9 trypsin units inhibited (TUI)/mg and 29.0-38.1 mg catechin equivalent (CE)/g, respectively) than cultivars of the Durango race (7.9-8.3 TUI/mg and 16.8-19.9 CE/mg, respectively). Bayo Victoria, a Durango race cultivar, had three times more lectins than levels reported for soybean. Cultivar influenced TI and tannins contents (p < 0.001), whereas site affected lectins (p < 0.001). An increase in levels of TI and tannins could be enhanced through breeding.

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Neurons that accompany the stria terminalis as it loops over the internal capsule have been termed collectively the supracapsular bed nucleus of the stria terminalis (BSTS). They form two cell columns, a lateral column and a considerably smaller medial column. The lateral column merges rostrally with the lateral bed nucleus of the stria terminalis and caudally with the central amygdaloid nucleus (central extended amygdala components). The medial column is continuous with the medial bed nucleus of the stria terminalis and the medial amygdaloid nucleus (medial extended amygdala districts). The connections of the BSTS were investigated in the rat by placing injections of Phaseolus vulgaris-leucoagglutinin (PHA-L) or retrograde tracers in different parts of the extended amygdala or in structures related to the extended amygdala. BSTS inputs and outputs were identified, respectively, by the presence of varicose fibers and retrogradely labeled neurons within the stria terminalis. The results suggest that the medial-to-lateral compartmentalization of BSTS neurons reflects their close alliance with the medial and central divisions of the extended amygdala. The medial BSTS contains primarily elements that correspond to the posterodorsal part of the medial amygdaloid nucleus and the medial column of the posterior division of the medial bed nucleus of the stria terminalis, and the lateral BSTS contains elements that correspond to the medial and lateral parts of the central amygdaloid nucleus and lateral bed nucleus of the stria terminalis. These results add strong support to the concept of the extended amygdala as a ring-like macrostructure around the internal capsule, and they are of theoretical interest for the understanding of the organization of the basal forebrain.

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The main objective of this work was to perform a comparative study of the antinutritional and/or toxic properties of phytohemagglutinin and trypsin-chymotrypsin inhibitor extracted from the seed of a commercial cultivar of edible bean used in Brazil. Bean proteins were extracted in acidic salt solution and fractionated by dialysis and centrifugation, then freeze-dried. The total freeze-dried bean extract and the globulin or albumin protein fraction were resuspended in distilled water and heated (100 degrees C, 30 min) for inactivation of hemagglutinin. Diets were prepared with unheated bean protein fractions and heated ones (100% trypsin inhibitor activity, but 0% phytohemagglutinin activity). As a result, the inhibition of growth and poor dietary protein utilization were observed in rats fed diets containing unheated bean protein fractions, but not in rats fed diets containing heated fractions. It was thus assumed that phytohemagglutinin is the main antinutritional and toxic factor that in dry bean (Phaseolus) protein and that trypsin inhibitor (Bowman-Birk type) did not interfere with rat growth.

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BACKGROUND: There is a relationship between stressful situations and the susceptibility towards certain diseases, probably mediated by immune system modifications. AIM: To study T lymphocyte proliferation in medical students during periods of differing academic stress. SUBJECTS AND METHODS: Blood samples were obtained from 42 medical students during a period of moderate academic stress, immediately before a final examination and after their summer vacations. T lymphocyte proliferation in response to 5, 10 and 20 mg/ml phytohemagglutinin was measured by the incorporation of 3H-thymidine, and plasma cortisol was measured by RIA. RESULTS: T lymphocyte stimulation index in response to all phytohemagglutinin concentrations was significatively lower in the period before examination than in the other two periods. There were no differences in the index between the period of moderate stress and after summer vacations. Plasma cortisol levels were 15.6 +/- 4.3, 18.6 +/- 5.8 and 16.7 +/- 5.1 mg/dl during the periods of moderate stress, before the examination and after vacations, respectively (p < 0.05 for the difference between examination and the other two periods). CONCLUSIONS: There is a decrease in lymphocyte proliferation and an increase in cortisol levels during a period of acute academic stress in medical students, suggesting that, the exposure of the healthy subjects to common stressful stimuli, may affect their immunocompetance.

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Se describe un método económico, sencillo y reproducible para obtener un extracto salubre de semillas de tres variedades de frijol común (Phaseolus vulgaris), con actividad mitogénica para linfócitos humanos, cuya potencia es dependiente de la dosis empleada y comparable a la de un producto comercial de importación y alto costo. Se realizaron 193 análisis citogenéticos durante un período de tres años. Con ello se confirmó la utilidad y confiabilidad del producto para uso clínico. La actividad mitogénica de los extractos de frijol, obtenidos mediante el método aqui descrito, es estable durante un año por lo menos, almacenado a -20-C, y cuando menos por cinco meses a 4-C

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The chemical composition, content of antinutritional factors, and the in vitro protein digestibility of grains of the pseudo-cereal Amaranthus were analyzed. The plants were grown in Brazil (without fertilizer), Puerto Rico (100 kg N/ha), and California (200 kg N/ha). The seed analysis gave the following values (%DM): 14.4 - 16.9 protein (N X 6.25), 4.8 - 6.8 fat, 2.5 - 3.9 ash, and 2.3 - 2.9 crude fiber. The trypsin inhibitors, phenolics and saponine contents were low, and the phytohemagglutinin activity, fairly low. The in vitro protein digestibility was 61 - 76%. Digestibility was not correlated to the analyzed proximal composition nor to the antinutritional factors. The grain composition indicates a food value equivalent to that of conventional food grains.

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