Total adult cardiovascular risk in Central America / Riesgo cardiovascular total en adultos en América Central

OBJECTIVE:To evaluate prevalence of cardiovascular risk among adults 40 years and older using population-based samples from six Central American countries. METHODS: Risk factors were derived from a multi-national cross-sectional survey implemented in 2003-2006, which included a sample of 4 202 participants aged 40 years and older. Charts produced by the World Health Organization and the International Society of Hypertension for the Region of the Americas sub-region B were used to predict risk on the basis of factors including age, sex, blood pressure, total serum cholesterol, smoking status, and diabetes status. RESULTS: Overall, 85.9% of the population was classified as having < 10% risk for cardiovascular events during the following ten years. The likelihood of being in this risk group decreased with age in both males and females. Four percent of respondents were identified as having > 20% risk. More than 75% of those with a 30-40% risk had previously been identified by health services, and an additional 23% were identified during the study, suggesting they could be diagnosed by opportunistic screening for diabetes, hypertension and hypercholesterolemia. Results of bivariate analysis showed that respondents who were male, older, obese and/or less educated had higher risk for cardiovascular events, but a multivariate analysis including education indicated highest risks for older, obese, and less educated females. CONCLUSIONS: Measuring cardiovascular disease risk identifies most cases of (or at risk for) diabetes, hypertension and hypercholesterolemia among adults 40 years and older. This strategy can facilitate implementation of control programs and decrease disabilities and premature mortality.

RESUMEN OBJETIVO:Evaluar la prevalencia del riesgo de padecer enfermedades cardiovasculares en adultos de 40 años de edad o mayores mediante el uso de muestras poblacionales obtenidas de seis países de América Central. MÉTODOS: Se tomaron los factores de riesgo de una encuesta transversal multinacional realizada entre 2003 y 2006, que incluyó una muestra de 4 202 participantes de 40 años de edad o mayores. Se usaron gráficos producidos por la Organización Mundial de la Salud y la Sociedad Internacional para la Hipertensión de la Región de las Américas, subregión B, para predecir el riesgo sobre la base de factores como la edad, el sexo, la presión arterial, las concentraciones totales de colesterol sérico, y la situación con respecto al tabaquismo y la diabetes. RESULTADOS: En términos generales, 85,9% de la población quedó clasificada en el grupo con un riesgo menor de 10% de sufrir episodios cardiovasculares en el transcurso de los 10 años siguientes. La probabilidad de pertenecer a este grupo de riesgo disminuyó con la edad, tanto en los hombres como en las mujeres. Se determinó que 4% de los encues-tados tenían un riesgo mayor de 20%. Más de 75% de los que tenían un riesgo de 30% a 40% ya habían sido identificados por los servicios de salud y otro 23% fue identificado durante el estudio, lo cual indica que los diagnósticos pueden hacerse mediante un tami-zaje oportunista para la detección de diabetes, hipertensión e hipercolesterolemia. Según los resultados del análisis bivariado, los entrevistados de sexo masculino, de edad más avanzada, obesos o con poca escolaridad tenían un mayor riesgo de sufrir episodios cardiovasculares, pero un análisis multivariado que abarcó el nivel educativo reveló que los riesgos más altos los tienen las mujeres mayores, obesas y con poca instrucción. CONCLUSIONES: El cálculo del riesgo cardiovascular permite identificar la mayoría de los casos (o personas con riesgo de presentar) diabetes, hipertensión e hipercolesterolemia en adultos de 40 años de edad o mayores. Esta estrategia puede facilitar la puesta en práctica de los programas de control, así como reducir la discapacidad y la mortalidad prematura.

Erythropoietin assay in mice made polycythemic by transfusion of heterologous red cells

A simple in vivo bioassay suitable testing of quality control of recombinant human erythropoietin (rHu-EPO) analogues was developed. Mice made polycythemic by intraperitoneal injection of 1.2 ml of a 80 per cent suspension of heterologous (rat) red cells were used as assay animals and splenic 59 Fe uptke as expression of the response to rHu-EPO. The assay took three days and the following schedule is propose: 1)intraperitoneal injection of 1.2 ml of washed packed red cells obtained from donor rats, 2) subcutaneous injection of test material 4-5 h after transfusion, 3) intravenous administration of 59 Fe tracer 48 h later, and 4) determination of splenic isotope uptake 6 h after injection. This method for the in vivo biossay of rHu-EPO analogues is an economical and reliable alternative to the existing bioassays of the hormone

Unmodified erythropoietic response to a beta adrenergic agonist in hypothyroid mice

Los agonistas beta-adrenérgicos poseen la propriedad de estimular la eritropoyesis en el modelo del ratón policitémico mediante inducción de la secreción de eritropoyetina. Considerando la existencia de un cúmulo de evidencias que indica que las hormonas tiroideas y las catecolaminas están íntimamente relacionadas, el objetivo del presente trabajo fue estimar la potencia eritropoyética del isoproterenol, un agonista beta-adrenérgico bien conocido, en ratones hipotiroideos. Animales adultos de la cepa CF-1 fueron alimentados con dieta estandard para roedores y agua (eutiroideos) o solución al 0.1 por ciento de propiltiouracilo durante 37 dÝas. La concentración de T4 en plasma, medida por RIA, fue 1.75 mug/ml y < 1.0 mug/ml en ratones eutiroideos e hipotiroideos, respectivamente. Los animales fueron transfundidos con 1.0 ml de eritrocitos homólogos y el efecto eritropoyético de 50, 500 o 5000 pg/kg de isoproterenol estimado mediante el método de incorporación de (59)Fe al eritrón. No se observaron diferencias estadísticamente significativas (P<0.05, test de t no apareado) entre animales eutiroideos e hipotiroideos. El hipotiroidismo, por lo tanto, no afecta la secreción de eritropoyetina inducida por isoproterenol en las presentes condiciones experimentales.

Immunoreactive erythropoietin in rodent submaxillary gland. Autonomic control of exocrine secretion and factors influencing its concentration

The SMG of mice and rats contain a heterologous group of biologically active factors. Some are well known, can be obtained at high purity and are well-characterized. There is strong evidence for the presence of others although they have not been purified. Finally, some of them are questionable and/or have not yet been characterized. EPO would be one of the factors whose presence in the SMG is strongly suspected, although its biological activity has not been demonstrated yet. Its presence in the gland, therefore, is only supported by radioimmunoassay data and immunocytochemical methods. Immunoreactive EPO is undetectable in the mouse SMG until the 30th day of postnatal life, increasing thereafter at a uniform rate and reaching adult levels by 50-60 days of age. The parallelism between its concentration in extracts of the gland, the size and relative proportion of GCT cells, could be accepted as indirect evidence for its localization in these cells. The rise in iEPO concentration in SMGs after androgen treatment, its fall following orchiectomy, and its reduction after duct ligation in proportion to the degree of degranulation of GCT cells lend support to the above hypothesis. Salivary secretions induced by either NE or ISO contain high levels of iEPO. A significant depletion of gland content is also observed. These two sets of data indicate that SMG exocrine iEPO secretion occurs and that this secretion is mediated by adrenergic receptors. The question whether the SMG also functions as an endocrine organ in relation to EPO can not be answered at present.