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This study focused on dating of a sediment core from the Alvarado Lagoon System, Veracruz, Mexico, calculating the sedimentation rate by using 210Pb to determine the tendency towards pollution by polycyclic aromatic hydrocarbons, organochlorides, the metals Cd, Cr, Cu, Hg, Ni, Pb, and V, and organic matter content. The activity of total Pb and supported Pb in the samples was 83.1 and 29.5 Bq kg-1, respectively, whereas the average estimated sedimentation rate was 0.48 ± 0.09 cm per year-1. The organic matter values exhibited linear behavior throughout the historical profile, with values under 2.5%. Metal concentrations followed the order V > Cr > Ni > Cu > Pb > Hg > Cd. Variations found in Cr, Ni, Pb, and V concentrations are basically due to three meteorological phenomena that hit the region: hurricanes Gladys, Hilda, and Janet in September of 1955. V, Ni, and Hg input comes from anthropogenic and lithogenic sources. The presence of individual polycyclic aromatic hydrocarbons showed no ascending accumulation pattern over time, nor did it show any significant statistical correlation to OM. As for the organochlorine pesticides, 63.61% of the total sum of these compounds were from the ciclodienics family. Concentration of p,p'-DDT was observed only in the earliest profile, from 1929.

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Étnia, calse y región son tres elementos constantes de nuestra nación. Es imposible comprender los procesos en curso si no se comprende no sólo la multiplicidad del fenómeno nacional, sino también su laberíntica evolutiva histórica.

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Environmental changes caused by logging in a mangrove swamp were studied in Barra de Tecoanapa, Guerrero, Mexico. Original forest included Rhizophora mangle, Laguncularia racemosa, Avicennia germinans and halophytic vegetation, and produced wood (164.03 m3/ha) and organic matter (3.9 g/m2/day). A total of 3.5 tons of wood per year were harvested from this area. Later, an average of 2,555 kg of maize per planting cycle were obtained (market value of 88 USD). Succession when the area was abandoned included strictly facultative and glycophyte halophytes (16 families, Cyperaceae and Poaceae were the best represented). After logging, temperatures increased 13 degrees C in the soil and 11 degrees C in the air, whereas salinity reached 52 psu in the dry season. These modified soil color and sand content increased from 42.6 to 63.4%. Logging was deleterious to species, habitat, biogeochemical and biological cycles, organic matter production, seeds, young plants, genetic exchange conservation of soil and its fertility, coastal protection, and aesthetic value; 3,000 m2 had eroded as the river advanced towards the deforested area (the cost/benefit analysis showed a ratio of 246:1). There was long-term economic loss for the community and only 30% of the site has recovered after five years.

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The effect of oil-extracted astaxanthin from the red crab or langostilla (Pleuroncodes planipes) on the growth and pigmentation of forty five rainbow trouts (Oncorhynchus mykiss) was investigated by feeding a test diet supplemented with 75 mg/kg of astaxanthin during six weeks and compared with a control diet. The oil-extraction process of the pigment is described. Weight, flesh astaxanthin concentration, and color (L*, a*, b*) of the flesh were measured at 0, 3, and 6 weeks. No apparent effect of astaxanthin supplementation was observed on fish development. In spite of the low free astaxanthin amount in the diet (8%), an acceptable carotenoid concentration in the flesh (3.60 +/- 0.78 mg/kg, w/w), and a red hue (H(ab)o = 44.13 +/- 2.36) were obtained at the end of the study. The red hue was strongly correlated with the carotenoid concentration (r = 0.98).

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En un paciente con diatesis hemorragica como principal manifestacion clinica, se identificaron simultaneamente un anticoagulante circulante de semiologia compleja, anticuerpos antiplaquetarios, alteraciones propias de la enfermedad de von Willebrand adquirida y deficiencia del factor XII, acompanantes del lupus eritematoso generalizado y el sindrome de Sjogren. En esta comunicacion se describen los procedimientos usados para identificar las multiples anormalidades encontradas en la paciente, su reaccion al tratamiento y se discuten sus mecanismos fisiopatologicos

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Se presenta el caso de una paciente con hemoglobinuria nocturna paroxistica y embarazo, que es una asociacion rara y con gran numero de complicaciones. La paciente fue tratada con anticoagulantes y tuvo un embarazo, parto y postparto satisfactorios En este trabajo se discute la naturaleza de las complicaciones y se hacen sugerencias para el tratamiento de pacientes con esta asociacion

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Se presentan los resultados de la biometria hematica inicial de 188 pacientes con diagnostico de leucemia aguda. Los resultados mostraron que los hallazgos mas frecuentes fueron trombocitopenia, anemia y presencia de blastos en la sangre periferica. Ademas, algunos de los resultados mostraron que tenian valor pronostico

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La reticuloendoteliosis leucemica es un padecimiento de curso insidioso, que se caracteriza por la gran esplenomegalia y la presencia de celulas con prolongaciones citoplasmaticas que le dan la apariencia de vellos. La informacion sobre este padecimiento en nuestro medio es nula, por lo que se considero de interes comunicar la experiencia obtenida en el diagnostico y tratamiento de seis pacientes con este padecimiento. Tanto los datos clinicos como los de laboratorio y la respuesta a los diversos tratamientos no difieren de la obtenida en otros paises, por lo que se considera que la falta de informacion no es por la ausencia de este padecimiento, sino probablemente por las dificultades de su diagnostico. Se espera que los informes sobre reticuloendoteliosis leucemica aumenten con el fin de establecer su frecuencia real en nuestro pais

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Segun lo publicado en la literatura, la combinacion de arabinosido de citosina y un agente antraciclico (daunorrubicina o adriamicina) es la forma mas eficaz de tratamiento de la leucemia mieloblastica aguda, ya que produce remision en 60 por ciento de los pacientes. Esta reaccion sin embargo, no se ha acompanado de prolongacion de la supervivencia. En nuestra serie de 22 pacientes, 18 de ellos desnutridos, el tratamiento con arabinosido de citosina y adriamicina produjo remisiones en solo 18 por ciento de los casos, y el tiempo que duro la reaccion fue muy breve. Hasta ahora no tenemos una explicacion adecuada para este inesperadamente bajo indice de reacciones

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En un paciente con saturnismo subagudo no laboral se presentaron diversas alteraciones hematologicas como anemia hipocromica, reticulosis transitoria. Tambien exhibio hiperferremia, eritropoyesis inefectiva demostrada por estudio de la cinetica del hierro y en la medula osea, datos caracteristicos del sindrome de anemia sideroblasitca, revelados con la tincion de azul de Prusia. Igualmente se descubrio saturnismo en la madre, el que se manifesto por anemia hipocromica y reticulocitosis.Ambas personas bebian agua conservada en una jarra de arcilla vidriada, que resulto ser la fuente de intoxicacion. Se recomienda estudiar a fondo la indole de la anemia en todo paciente con plumbismo

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In 25 patients with acute leukemia that presented chantes in liver function tests, 29 liver biopsies were done by percutaneous needle or peritoneoscopy and directed needle, to determine the nature of the lesion. In one case leukemic infiltration was found; 16 patients showed nonspecific lesions, one, granulomatous hepatitis, one, viral hepatitis; one showed no changes in the biopsy. In these twenty cases the treatment was not modified, the survival time was from 15 to 57 months (median 25 months), and 14 an still in remission. Five patients (20%) showed drug-induced hepatitis; in these it was necessary to modify to chemotherapy, the survival time in four cases was 2 to 9.6 months (median 4.8 months) and one is still in remission after 36 months of treatment. It is concluded that hepatic biopsy may be very useful in evaluating the undesirable effects of treatment of acute leukemia and in making therapeutic decisions. The risks of this procedure and the contraindications are similar in patients with acute leukemia and those with other diseases.

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