Hematologic reconstitution following high-dose and supralethal chemoradiotherapy using stored, noncryopreserved autologous hematopoietic stem cells.

Although cryopreservation is the standard for autotransplantation, it has logistic and financial disadvantages in undeveloped countries such as Colombia. In 47 patients, peripheral blood was refrigerated at 4 degrees C up to 144 h before autotransplantation. For mobilization, 27 men and 20 women of median age 37 years affected with hematologic malignancies received G-CSF. The 17 patients in Group 1 showed pre-refrigeration CFU-GM of 2.62 x 10(5)/kg (range 0.36 to 16.6 x 10(5)/kg) and at re-infusion, 1.36 x 10(5)/kg (range 0 to 6.32 x 10(5)/kg) of 83% viability (range, 78% to 96%). These patients showed >0.5 x 10(9)/L granulocytes on day +11 (range, 9 to 15) and >20 x 10(9)/L platelets on day +16 (range, 11 to 44). The 25 patients in Group 2 showed CD34 of 3.9 x 10(6)/kg (range, 0.16 to 9 x 10(6)/kg) and mononuclear cell count (MNC) of 8.7 x 10(8)/kg, reaching >0.5 x 10(9)/L granulocytes at day +13 (range, 10 to 17) and >20 x 10(9)/L on day +15 (range, 14 to 20). Among the 5 patients in Group 3, the average of MNC of 12.7 x 10(8)/kg was reached and >0.5 x 10(9)/L granulocytes on day 11 (range, 10 to 16) and >20 x 10(9)/L on day 14 (range, 10 to 18). No differences were observed between the groups. Refrigeration of stem cells appears to be a simple, effective, and inexpensive method that should be considered for autotransplants within a few days of harvesting when resources are limited for long-term storage.

Autosomal, mtDNA, and Y-chromosome diversity in Amerinds: pre- and post-Columbian patterns of gene flow in South America.

To evaluate sex-specific differences in gene flow between Native American populations from South America and between those populations and recent immigrants to the New World, we examined the genetic diversity at uni- and biparental genetic markers of five Native American populations from Colombia and in published surveys from native South Americans. The Colombian populations were typed for five polymorphisms in mtDNA, five restriction sites in the beta-globin gene cluster, the DQA1 gene, and nine autosomal microsatellites. Elsewhere, we published results for seven Y-chromosome microsatellites in the same populations. Autosomal polymorphisms showed a mean G(ST) of 6.8%, in agreement with extensive classical marker studies of South American populations. MtDNA and Y-chromosome markers resulted in G(ST) values of 0.18 and 0.165, respectively. When only Y chromosomes of confirmed Amerind origin were used in the calculations (as defined by the presence of allele T at locus DYS199), G(ST) increased to 0.22. G(ST) values calculated from published data for other South American natives were 0.3 and 0.29 for mtDNA and Amerind Y chromosomes, respectively. The concordance of these estimates does not support an important difference in migration rates between the sexes throughout the history of South Amerinds. Admixture analysis of the Colombian populations suggests an asymmetric pattern of mating involving mostly immigrant men and native women.

Sickle cell anemia and beta-globin gene cluster haplotypes in Colombia.

We studied 46 unrelated sickle cell anemia patients from the western region of Colombia which has the largest Black population of the country. Twenty-three children and 23 adults were studied. The distribution of haplotypes in the children was 58% Bantu, 38% Benin, and 4% Senegal, and in the adults it was 59.4% Bantu, 35.1% Benin, and 5.5% Senegal (p = 0.920). All 92 chromosomes had typical African haplotypes, Bantu 55.5%, Benin 34.8%, Senegal, 4.3%, and Cameroon, 5.4%. Our results suggest a lack of differential survival among patients with sickle cell anemia and typical beta-globin gene cluster haplotypes. They also agree closely with historical data that indicate that most African slaves brought to Colombia originated from Angola (Bantu population) and the Sao Thomó Island in the Bight of Benin (Central West Africa).

[Colorimetric determination of tryptophan in foods]. / Determinación colorimétrica de triptófano en alimentos.

A modification of the method of Spies and Chambers for the determination of tryptophan in food products is described. The results were compared with those obtained with the microbiological method and gave identical results. The results on tryptophan content of bean broth were consistently higher than expected. Apparently, bean broth contains certain factors, which interfere with both procedures. In summary, the modified method is simple and easy to perform in large numbers of samples.

Determinacion colorimetrica de triptofano en alimentos. / Colorimetric determination of tryptophan in foods

Se describe una modificacion del metodo colorimetrico de Spies y Chambers para la determinacion de triptofano en alimentos, el cual se basa en la condensacion del aminoacido con el p-dimetilamino benzaldehido en medio de acido sulfurico. Ese producto es luego tratado con solucion de nitrito sodico, produciendose una coloracion azul proporcional a la cantidad de triptofano presente. Se variaron las concentraciones de acido sulfurico y de nitrito de sodio hasta obtener un maximo desarrollo del color (acido sulfurico 16 N y solucion de nitrito de sodio al 0.35%). Se aplico el metodo a una diversidad de alimentos, coincidiendo los resultados con aquellos obtenidos por el metodo microbiologico, con excepcion de los caldos de frijol, los que aparentemente contienen factores que interfieren con ambos metodos. En resumen, el procedimiento es sencillo, sensitivo, y da resultados reproducibles

[Consumption of selenium in the city of Caracas in comparison with other cities of the world]. / Consumo de selenio en la ciudad de Caracas en comparación con el de otras ciudades del mundo

Ingestion of selenium in Caracas, compared with some other cities. Fourty-two different food products acquired in Caracas were analized for their selenium content and the results compared with those reporte in food from Beltsville, Md. When the selenium level of a normal diet of 2200 cal is calculated, a selenium ingestion of about 220 mcg/d is found for Caracas, compared with several diets from Canada shows that the they contain from 1/3 to 2/3 of the amount of selenium as similar as similar diets in Caracas.

[Composition of bean broth]. / Composicion de caldos de frijoles

Bean broth is used as weaning food. Six samples were studied as well as the respective residues and the raw beans from which they were obtained. The proportion of components found in the broths expressed as percentage of that in the raw beans was 11.9% for proteins, 9.4% for triptophane, 4.7% for lysine, 5.6% for methionine, 3.2% for cystine, 13.1% for thiamin, 26.5% for riboflavin and 24.1% for niacin. Cooking losses were greatest in cystine, thiamin and niacin. According to these results, the broths proteins have a lower nutritive values than the cooked beans.