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131.
R Zeledón R Bola?os M R Espejo Navarro M Rojas 《Memórias do Instituto Oswaldo Cruz》1988,83(3):361-365
Comparison by scanning electron microscopy (SEM) of Trypanosoma cruzi flagellates attached to the cuticle of the rectal gland of infected Dipetalogaster maxima nymphs, showed marked differences before and after feeding. Before feeding numerous metacyclic trypomastigotes were observed among the abundant epimastigotes that formed the carpet of flagellates. On the other hand, in insects that were allowed to urinate for 24 hours after a meal, the metacyclics were scarce, indicating that they had been detached by the urine flow. An asymmetric type of cell division, probably originating both an epi- and a trypomastigote, was occasionally observed. The occurrence of swellings at different levels of the flagella of epimastigotes suggests that secondary sites of attachment may be common. 相似文献
132.
The two alkaloids, α- and β-erythroidine have been identified in 0.034 and 0.11 % yield in flowers of Erythrina americana and could be responsible for the hypnotic activity of flower extracts. 相似文献
133.
S. Snchez Villasclaras MaE. Martínez Sancho MaT. Espejo Caballero A. Delgado Prez 《International biodeterioration & biodegradation》1996,38(3-4)
With olive mill wastewater (alpechin) used as a nutrient medium, the influence of the aeration level and the composition of the culture medium were analysed in relation to the concentration of alpechin and KNO3 added in a batch culture of the microalgae Chlorella pyrenoidosa and Scenedesmus obliquus. The pH and temperature of the culture were previously fixed at 6.5 and 30°C. As kinetic parameters, the maximum specific growth rate (μm) and the biomass productivity (Pmax) were determined. The biomass composition obtained was evaluated for chlorophyll and crude protein content as well as fatty-acid composition corresponding to the lipid fraction. To achieve a balanced biomass composition in terms of proteins and lipids, the most suitable conditions included an alpechin concentration of 10%, without the addition of nitrates and with an aeration level of 1 v/v min. Under these conditions, the μm values reached with both microalgae were around 0.03h−1. 相似文献
134.
Guillermo Moscatelli Ada Berenstein Ana Tarlovsky Susana Siniawski Miguel Biancardi Griselda Ballering Samanta Moroni Marta Schwarcz Susana Hernández Facundo García-Bournissen Andrés Espejo Cozzi Héctor Freilij Jaime Altcheh 《Memórias do Instituto Oswaldo Cruz》2015,110(5):644-648
The primary objective of this study was to estimate the prevalence of this disease in
women of childbearing age and children treated at health centres in underserviced
areas of the city of Buenos Aires. Demographic and Chagas disease status data were
collected. Samples for Chagas disease serology were obtained on filter paper and the
reactive results were confirmed with conventional samples. A total of 1,786 subjects
were screened and 73 positive screening results were obtained: 17 were from children
and 56 were from women. The Trypanosoma cruzi infection risk was
greater in those individuals who had relatives with Chagas disease, who remember
seeing kissing bugs, who were of Bolivian nationality or were born in the Argentine
province of Santiago del Estero. The overall prevalence of Chagas disease was 4.08%.
Due to migration, Chagas disease is currently predominantly urban. The observed
prevalence requires health programme activities that are aimed at urban children and
their mothers. Most children were infected congenitally, which reinforces the need
for Chagas disease screening of all pregnant women and their babies in Argentina. The
active search for new cases is important because the appropriate treatment in
children has a high cure rate. 相似文献
135.
136.
Two chromosome races found in Ameles abjecta (Cyrillo) are reported: Type A (2n=29 in males) and Type B (2n=15 in males). The NF in both is 30 in males. 相似文献
137.
Angela Mosquera Alexander Rodríguez Carlos Soto Felice Leonardi Angela Espejo Oscar F. Sánchez Carlos J. Alméciga-Díaz Luis A. Barrera 《Process Biochemistry》2012,47(12):2097-2102
Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disease caused by the deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS) enzyme. Currently, specific therapies are not available for MPS IVA patients. In this study, a biologically active recombinant GALNS enzyme (rGALNS) produced in Escherichia coli was purified through a two-step chromatography process. The effect of temperature and pH on purified rGALNS stability was evaluated, as well as the stability in human serum. Finally, the uptake of rGALNS by HEK 293 cells and MPS IVA fibroblasts was evaluated. The use of a semi-continuous process allowed the production of an active extracellular rGALNS, which was used for protein purification. The purified rGALNS showed a specific activity of 0.29 U mg?1 and a production yield of 0.78 mg L?1. The rGALNS presented an optimal pH of 5.5 and was stable for 8 days at 4 °C. In human serum it was stable for up to 6 h. rGALNS was not taken up by the cultured cells, suggesting that N-linked oligosaccharides are not necessary for the production of an active enzyme or enzyme stability but for the cell uptake of protein. This study shows the first characterization of rGALNS produced by E. coli, and provides important information about purification, stability, and glycosylations effect for this type of enzymes. 相似文献