18S-rDNA Sequencing, enzyme patterns and morphological characterization of trichophyton isolates

Dermatophytes, capable to use keratin of the host for nutrition, belong to one of the major groups of pathogenic fungi. Since dermatophytes are a closely related group they share various common features, and the morphology of isolates of a given species can be atypical, making species identification and differentiation even more difficult. Many methods have been explored in attempts to distinguish dermatophytes, but the combined use of different approaches for the investigation of the intraspecific and interspecific variability of Trichophyton continues to be scarce. Some studies have shown that amplified fragments of the small ribosomal DNA subunit 18S contains variable regions which can be used to discriminate between medically relevant yeast species, indicating that these regions could also be used for differentiation between dermatophytes. In our study, sequence analysis of the 18S-rDNA gene was combined with morphological and biochemical criteria in order to detect genetic differences between seven Trichophyton isolates and estimate their phylogenetic relationships. The results show that the isolates investigated belong to the Trichophyton group, which potentially contains the Trichophyton rubrum cluster.

Characterization of alkaline xylanases from "Bacillus pumilus"

Alkaline xylanases produced by four different strains of "Bacillus pumilus" were characterized. The optimal pH and temperature were pH 9.0 and 60ºC for strain 13(a), and pH 8.0 and 55ºC for strains 5(2), 5(14), and 4(a). Under these conditions the following activities were found after 10 min in the presence of 1(per cent) xylan (birchwood): 328 U.ml(-1), 131 U.ml(-1), 90 U.ml(-1), and 167 U.ml(-1), respectively, for the four strains. The enzymes were stable at 40ºC, with 40(per cent) of the xylanase activity remaining after 2 hours for the enzymes of strain 5(2) and 60(per cent) for the other three strains. Stability at 50ºC was improved by addition of glycerol. Taking into account the conditions under which kraft pulps are bleached during the manufacture of paper xylanases from "B. pumilus" exhibit favorable potential for application to bleaching in the paper making process.

Método simplificado para medir 17-OH progesterona plasmática por radioinmunoanálisis / SImplified method to measure 17-OH plasmatic progesterone by radioimmunoanálysis

La 17-hidroxiprogesterona (17-OHP4) es una hormona esteroide que se sintetiza en glándulos suprarrenales, ovarios y testículos. En la mujer normal durante la fase luteínica, los niveles periféricos reflejan la actividad secretora de ovarió, sin embargo, esta ciclicidad puede verse afectada por patologías como la hiperplasia adrenal congénita o la poliquistosis ovárica, por lo que el poder medir esta hormona es de gran utilidad en las clínicas de endocrinología ginecológica, endocrinología y andrología. En el presente trabajo se describe un método práctico para medir 17-OHP4 en sangre periférica por radioinmunoanálisis al utilizar un antisuero altamente específico. La utilidad del método, descrita con estudios de confiabilidad apropiados presentan una sensibilidad de la curva patrón de 10 picogramos, la precisión muestra un coeficiente de variación intra-análisis < ó = 11.9 por ciento e inter-análisis < ó = 10.0 por ciento, la exactitud fue > ó = 95 por ciento y la especificidad es demostrada por la caracterización del antisuero frente a otros esteroides. Al medir la 17-OHP4 en ng/ml en plasma de mujeres bajo diferentes condiciones fisiológicas, encontramos que los niveles de esta hormona en el día -5 de la fase proliferativa fueron de 0.31 ñ 0.24 nanogramos (ng)/ml y en el dia +7 de la fase secretora de 1.47 ñ 0.65 ng/ml. En las pacientes sometidas a estimulación con ACTH muestran, con respecto a la muestra basal, un incremento del doble de los niveles a los 30 minutos y que continúa en aumento hasta los 90 min. con cierta tendencia a la baja a los 120 minutos. Los resultados de este estudio permiten medir 17-OHP4 en plasma humano con buen grado de seguridad y facíl manejo, logrando además reducir el costo operativo

Efeito da temperatura e de ativadores no processo de extracao da bromelina / Effect of temperature and of activators on the extraction process of bromelain

No processo de extracao de bromelina de caules de abacaxi Zeiro ananas comosus cultivar Cayenne, a acetona mostrou menor eficiencia que sulfato e amonio, em relacao ao balanco material. O estudo da estabilidade em diferentes temperaturas, durante 90 dias, das amostras obtidas indicou resultados mais favoraveis na amostra preparada a partir de extrato filtrado a 40 graus centigrados e preciptado por sulfato de amonio