Trypanosoma cruzi: growth requirements at different temperature in fetal bovine serum or peptide supplemented media.

An enriched synthetic medium with low molecular weight peptides allows Trypanosoma cruzi epimastigotes to grow at 26-37 C. Using this medium, the growth requirements of T. cruzi were compared at different temperatures. When supplemented with fetal bovine serum or serum peptides, nine amino acids were absolutely required from the first passage, while additional amino acids and amino acid precursors were needed to support growth during a second passage. Five amino acids (beta-alanine, glutamine, cysteine, ornithine, and threonine) were also required absolutely at temperatures ranging between 30 and 37 C. Nine vitamins were needed at all temperatures, while ascorbic acid and ergocalciferol were not necessary at any temperature. The remaining amino acids and vitamins showed a variable role as growth factors depending on the temperature increase. In peptide supplemented media, requirements for amino acids and their precursors, as well as vitamins and nucleotides, increased markedly when compared with the protein supplemented medium. A peptide composed of one glutamic acid, two alanines, and one lysine can substitute for serum for trypanosomal growth at all temperatures. Several minimum media have been prepared in which epimastigote forms of T. cruzi can grow at 26-37 C for more than 10 passages.

Hemoglobin Hofu associated with beta 0-thalassemia.

A mild anemia (hemoglobin 9 g/dl) was found in a patient from Seville (Spain) with marked morphological abnormalities in the peripheral blood smear. The red cell osmotic fragility showed a mild resistance curve with a mean cell fragility (MCF) of 0.375% NaCl (normal = 0.450). Chemical Chemical and thermal instability test and search for inclusion bodies gave positive results. Hemoglobin electrophoresis at pH 8.9 revealed absence of Hb A, a major component of fast mobility (94%), and increased Hb F and Hb A2 levels (1.5% and 4.6%, respectively). The fast fraction, isolated and purified by means of cellulose acetate electrophoresis, precipitated in acid acetone and treated with urea 8 M and mercaptoethanol, revealed an anomalous beta chain. Trypsin-digested globin peptides were separated by high-voltage electrophoresis at pH 6.4 and ascendant chromatography. With differential staining, an extra peptide was detected in an unusual site, more anodic than alpha Tp4 but in lower position. Peptide map of the fast beta chain, stained with ninhydrin, and also for Tyr, confirmed the position of the new peptide and the absence of the usual beta Tp13. The new peptide, separated by high-voltage electrophoresis at pH 3.5, revealed absence of Val and the presence of an additional Glu residue, which should appear only in position beta 126. The diagnosis of Hb Hofu (alpha 2 beta 2 126 Val----Glu; H4) was reached, thus interpreting its increase and the absence of Hb A, as an association with beta o-thalassemia, producing a mild hemolytic anemia. Evidence was obtained that Hb Hofu is a mild unstable hemoglobin variant.

Caracteristicas hematologicas de la poblacion del Estado Falcon (Venezuela). I. Variantes hemoglobinicas, antigeno Australia y niveles de immunoglobulinas. / Hematologic characteristics of the population of the Falcon State (Venezuela). I. Hemoglobin variants, Australian antigen and immunoglobulin levels

Se estudio 501 donantes voluntarios del Banco de Sangre del Hospital Alfredo van Grieken de Coro en cuanto a variantes o alteraciones hemoglobinicas, antigeno Australia y niveles de inmunoglobulinas. Los grupos sanguineos ABO y Rh mostraron una distribucion que puede considerarse caracteristica para la poblacion venezolana. Se encontro 2,40% con valores aumentados de Hb F, 2,99% con valores moderadamente aumentados de HbA2, 0,40% con valores francamente aumentados de A2, 3,79 de Hb AS, 0,80% de Hb AC y 0,20% de Hb AD Punjab, lo cual indica que en el estado Falcon de cada 11 sujetos 1 tiene alguna variante o alteracion hemoglobinica. Estos resultados representan la intensa mezcla racial que viene operandose en el estado desde la epoca del descubrimiento, habiendose encontrado variantes hemoglobinicas prevalentes en africanos y espanoles. El antigeno Australia, estudiado en 300 donantes, mostro una positividad del 2,33%, que es mayor que la encontrada en Caracas.Los niveles de inmunoglobulinas A, G y M, determinadas en 25 donantes, resultaron un poco mas altos que los obtenidos en donantes de Caracas