Sistema de reprodução em Caesalpinia echinata Lam. implantada em arboreto experimental

O sistema de reprodução de Caesalpinia echinata Lam.foi estudado por isoenzimas em arboreto, usando os modelos de cruzamentos mistos e cruzamentos correlacionados. Desvios do modelo misto de reprodução foram evidenciados pela heterogeneidade nas freqüências alélicas do pólen que fecundou as diferentes árvores. A taxa de cruzamento multiloco foi alta (t m= 0,969), indicando que a espécie é predominantemente alógama. A alta variação na taxa de cruzamento individual (tvariando de 0,77 a 1,00) indica que a espécie não é auto-incompatível. Diferença positiva e significativamente diferente de zero foi detectada entre as taxas de cruzamento multiloco e uniloco, sugerindo que ocorreram cruzamentos endogâmicos na população (t m - t s = 0,078). A correlação de paternidade foi alta (r p = 0,822), demonstrando que as progênies são constituídas principalmente por irmãos-completos. O coeficiente de coancestria nas progênies foi alto (tetaxy = 0,269) e superior ao esperado em progênies de meios-irmãos (0,125). Os resultados são discutidos em termos de amostragens para a conservação genética e coleta de sementes para a recuperação ambiental.

Effects of tryptophan depletion on anxiety induced by simulated public speaking

Several lines of evidence point to the participation of serotonin (5HT) in anxiety. Its specific role, however, remains obscure. The objective of the present study was to evaluate the effect of reducing 5HT-neurotransmission through an acute tryptophan depletion on anxiety induced by a simulated public speaking (SPS) test. Two groups of 14-15 subjects were submitted to a 24-h diet with a low or normal content of tryptophan and received an amino acid mixture without (TRY-) or with (TRY+) tryptophan under double-blind conditions. Five hours later they were submitted to the SPS test. The state-trait anxiety inventory (STAI) and the visual analogue mood scale (VAMS) were used to measure subjective anxiety. Both scales showed that SPS induced a significant increase in anxiety. Although no overall difference between groups was found, there was a trend (P = 0.078) to an interaction of group x gender x phases of the SPS, and a separate analysis of each gender showed an increase in anxiety measured by the STAI in females of the TRY- group. The results for the female TRY- group also suggested a greater arousing effect of the SPS test. In conclusion, the tryptophan depletion procedure employed in the present study did not induce a significant general change in subjective anxiety, but tended to induce anxiety in females. This suggests a greater sensitivity of the 5HT system to the effects of the procedure in this gender.

Effect of an aqueous extract of Phaseolus vulgaris on the properties of tail tendon collagen of rats with streptozotocin-induced diabetes

Changes in the structural and functional properties of collagen caused by advanced glycation might be of importance for the etiology of late complications in diabetes. The present study was undertaken to investigate the influence of oral administration of aqueous pod extract (200 mg/kg body weight) of Phaseolus vulgaris, an indigenous plant used in Ayurvedic Medicine in India, on collagen content and characteristics in the tail tendon of streptozotocin-diabetic rats. In diabetic rats, collagen content (117.01 ± 6.84 mg/100 mg tissue) as well as its degree of cross-linking was increased, as shown by increased extent of glycation (21.70 ± 0.90 µg glucose/mg collagen), collagen-linked fluorescence (52.8 ± 3.0 AU/µmol hydroxyproline), shrinkage temperature (71.50 ± 2.50ºC) and decreased acid (1.878 ± 0.062 mg hydroxyproline/100 mg tissue) and pepsin solubility (1.77 ± 0.080 mg hydroxyproline/100 mg tissue). The alpha/ß ratio of acid- (1.69) and pepsin-soluble (2.00) collagen was significantly decreased in streptozotocin-diabetic rats. Administration of P. vulgaris for 45 days to streptozotocin-diabetic rats significantly reduced the accumulation and cross-linking of collagen. The effect of P. vulgaris was compared with that of glibenclamide, a reference drug administered to streptozotocin-diabetic rats at the dose of 600 µg/kg body weight for 45 days by gavage. The effects of P. vulgaris (collagen content, 64.18 ± 1.97; extent of glycation, 12.00 ± 0.53; collagen-linked fluorescence, 33.6 ± 1.9; shrinkage temperature, 57.0 ± 1.0; extent of cross-linking - acid-soluble collagen, 2.572 ± 0.080, and pepsin-soluble collagen, 2.28 ± 0.112) were comparable with those of glibenclamide (collagen content, 71.5 ± 2.04; extent of glycation, 13.00 ± 0.60; collagen-linked fluorescence, 38.9 ± 2.0; shrinkage temperature, 59.0 ± 1.5; extent of cross-linking - acid-soluble collagen, 2.463 ± 0.078, and pepsin-soluble collagen, 2.17 ± 0.104). In conclusion, administration of P. vulgaris pods had a positive influence on the content of collagen and its properties in streptozotocin-diabetic rats.

Composição físico-química do vinho Cabernet Franc proveniente de videiras conduzidas no sistema lira aberta

O objetivo do trabalho foi avaliar as características físico-químicas do vinho Cabernet Franc proveniente de videiras conduzidas no sistema lira aberta durante o ciclo vegetativo de 1995/1996. O experimento foi realizado em oito vinhedos localizados nos municípios de Bento Gonçalves e Monte Belo do Sul, Estado do Rio Grande do Sul. Os vinhos foram elaborados por microvinificação, com duas repetições para cada vinhedo, os quais foram analisados por processos físico-químicos, espectrofotometria de absorção atômica e cromatografia líquida e gasosa. Os parâmetros das variáveis mais significativas foram os seguintes: álcool 9,65%, acidez total 69 meq L-1, pH 3,46, extrato seco reduzido 16,0 g L-1, K nas cinzas 49,4%, ácido tartárico 33 meq L-1, glicerol 9,3 g L-1, prolina 669 mg L-1, antocianinas 330 mg L-1, taninos 1,19 g L-1, intensidade de cor 0,286, K 1.078 mg L-1, metanol 101,7 mg L-1 e soma dos álcoois superiores 450 mg L-1. Os resultados dos vinhos avaliados foram relativamente similares aos encontrados em vinhos Cabernet Franc da mesma região elaborados com uvas provenientes de videiras conduzidas em latada. Eles evidenciam que o sistema de condução da videira em lira aberta constitui-se como alternativa para a produção de vinho tinto fino na Serra Gaúcha.