Social and environmental health determinants and their relationship with parasitic diseases in asymptomatic children from a shantytown in Buenos Aires, Argentina.

Health inequities are a common problem for all countries and are the result of not only adverse social conditions but also poor public policies. Today chronic diseases represent the most relevant threats and are a current challenge. Parasitic infections, a leading cause of child morbidity affecting low-income populations, can be transmitted because of an unhealthy environment. Notwithstanding, scarce data have been published on the epidemiological profile of intestinal parasitoses in asymptomatic children living in shantytowns. Vulnerable populations settled in slums are growing in Argentina, particularly in Buenos Aires city. Consequently, this work intended to screen healthy carriers of enteric parasites and determine the epidemiologic profile in asymptomatic children residing in one of those communities, to explore risk factors associated with the transmission of parasites, and to initiate a basic health education campaign to promote healthy behavior in the community. Fecal samples (n = 138) were analyzed by conventional parasitological methods and a survey gathered data on symptoms, family composition, and environmental and hygiene-related variables. High prevalence of feco-orally-transmitted parasitoses (83·3%) and polyparasitism were remarkable findings. The main environmental health determinants were those related to excreta disposal and water provision. Health promotion actions were performed through the diffusion of a set of posters with iconic images and brief messages for health education. Results suggest the need for an environmental sanitation policy to complement health promotion actions. It is essential to spread the results of investigations that address inequities and social determinants of health in order to integrate data with local political processes and alert on acceptable actions for developing appropriate interventions.

The agreement chart as an alternative to the receiver-operating characteristic curve for diagnostic tests.

OBJECTIVE: For diagnostic tests, the most common graphical representation of the information is the receiver-operating characteristic (ROC) curve. The "agreement chart" displays the information of two observers independently classifying the same n items into the same k categories, and can be used if one considers one of the "observers" as the diagnostic test and the other as the known outcome. This study compares the two charts and their ability to visually portray the various relevant summary statistics that assess how good a diagnostic test may be, such as sensitivity, specificity, predictive values, and likelihood ratios. STUDY DESIGN AND SETTING: The geometric relationships displayed in the charts are first described. The relationship between the two graphical representations and various summary statistics is illustrated using data from three common epidemiologically relevant health issues: coronary heart disease, screening for breast cancer, and screening for tuberculosis. RESULTS: Whereas the ROC curve incorporates information on sensitivity and specificity, the agreement chart includes information on the positive and negative predictive values of the diagnostic test. CONCLUSION: The agreement chart should be considered as an alternative visual representation to the ROC for diagnostic tests.

[Role of plasma procalcitonin determination in the postoperative follow-up of cephalic pancreatoduodenectomy]. / Papel de la determinación de procalcitonina plasmática en el seguimiento postoperatorio de la duodenopancreatectomía cefálica.

BACKGROUND: Procalcitonin (PCT) is widely accepted as an early marker of the severity of sepsis and its prognosis. This study was designed to evaluate the utility of PCT in the early diagnosis of immediate postoperative complications (infectious and non-infectious) following cephalic pancreatoduodenectomy (PD). PATIENTS AND METHOD: Thirty-one patients who underwent elective PD were prospectively analyzed. The patients were divided into two groups according to the presence or absence of postoperative complications. Plasma PCT concentrations were determined by an immunochromatographic method. The correlation between PCT concentrations and the presence of complications, as well as the existence of statistically significant differences in PCT concentrations between the 2 groups of patients, were analyzed. The value of plasma PCT concentrations in predicting complications compared with that of other biochemical variables (C-reactive protein, lactic acid, base excess) and clinical parameters (systemic inflammatory response syndrome) was analyzed. RESULTS: Significant differences in PCT concentrations were found between the two groups. An inverse correlation between marker levels and patient outcome was observed. The variables that best predicted the development of complications were PCT concentrations and axillary temperature. CONCLUSIONS: Plasma PCT should be taken into account as a useful marker for postoperative clinical course in the follow-up of PD and for the early detection of non-infectious complications.

Protein restriction and progression of chronic renal failure

La insuficiencia renal crónica (RC) una vez establecida, progresa inoxeroblemente hacia el estadio terminal, determinando la supresión total de la función renal. El enlentecimiento de la velocidad de progresión de la enfermedad es por lo tanto, uno de los objetos más importantes de la nefrología actual. La restricción proteica ha sido la estrategia terapéutica más utilizada para este fin, observándose modificacions de las alteraciones hemodinámicas intraglomerulares a nivel experimental y enlentecimiento de la velocidad de progresión en la mayoría de los pacientes. Por ese motivo estudiamos el efecto de la restricción proteica sobre la velocidad de progresión en 7 pacientes con Cr plasmáticas entre 2,74-5,3 mg/dl, cuyos datos clínicos figuran en la Tabla 1. La velocidad de progresión se evaluó por el método de la 1/CR cada 1-3 meses durante 1 año de ingesta proteica adlibitum y durante 23-40 meses de restricción proteica. La ingesta proteica indicada, fue individualmente calculada considerando el requerimiento proteico basal y la capacidad renal para excretar urea (Tabla 2). La ingesta proteica observada durante el período de restricción proteica, fue significativamente menor que la ingesta ad-libitum aunque superior a la indicada (Fig. 1). El curso de la enfermedad (Fi. 2) mostró durante el año de ingesta ad-libitum, enfermedad progresiva en 4/7 pacientes (panel izquierdo), siendo relativamente estable en los 3 restantes (panel derecho). Despues de seis meses de iniciada la restricción proteica, los pacientes con enfermedad progresiva previa mostraron un enlentecimiento de su velocidad de progresión, ya que las determinaciones de 1/Cr reales de este período, se ubicaron por encima de las correspondientes a la evolución natural de la enfermedad. Los pacientes con enfermedad relativamente estable, mostraron durante el tratamiento, una aceleración de la velocidad de progresión en 2 casos y una mejoría en el restante. Durante los primeros 6 meses de restricción proteica (Fig. 3), se observó un aumento transitorio de la Cr plasmática que fue máximo a los 2,7 meses y una disminución de la ureia plasmática que a los 1,5 meses alcanzó un valor cercano al estimado al prescribir la dieta (Tabla 2). La excreción media de creatinina (1118 + 25 mg/día1,73 m**2 SC) se mantuvo estable a lo largo de todo el estudio. Las cifras de presión arterial sistólica y diastólica no mostraron cambios significativos entre el período de ingesta ad-libitum y el de restricción proteica

Estandarización de un método analítico: aplicación a la determinación de glicosaminoaglicanos urinarios / Standardization of a analytical method: aplication to the determination of urinary glycosaminoglycans

Se presenta la estandarización de un método para la determinación cuantitativa de glicosaminoglicanos (GAGs) urinarios, empleando una combinación de los métodos descriptos por Di Ferrante y Bitter y Muir, con algunas modificaciones que debieron ser introducidas para adecuarlo a nuestras condiciones experimentales. La determinación se basa en la precipitación de los GAGs por acción de bromuro de cetiltrimetilamonio, seguida de la hidrólisis del polímero y la posterior reacción colorimétrica con carbazol de los ácidos hexurónicos liberados. Se describen, detalladamente, los estudios de estandarización: determinación de la precisión de las distintas etapas del método, linealidad y carta de control de las pendientes de las curvas de calibración, ensayos de recuperación, investigación de interferencias y variaciones en las condiciones de trabajo. Esta metodología puede servir de base para establecer protocolos de control de cualquier procedimiento analítico

Dynamics of transmission of Trypanosoma cruzi in a rural area of Argentina: III. Persistence of T.cruzi parasitemia among canine reservoirs in a two-year follow-up

Foi realizada em 1984 uma nova pesquisa epidemiológica dos cäes domésticos e seguimento dos indivíduos que apresentaram parasitemia dois anos antes a fim de compreender a relaçäo entre a parasitemia e a idade dos cäes, empregando para isso técnicas sorológicas e xenodiagnóstico. A persistência da parasitemia foi independente ou pouco relacionada à idade, confirmando assim o padräo observado em 1982. Da mesma maneira, nos cäes soropositivos näo se registrou nenhuma diminuiçäo significativa com respeito a idade em: a) a probabilidade de descobrir parasitas por meio de um seguimento durante 2 anos; b) sua capacidade de infecçäo para a ninfas de 3ª e 4ª fase de T. infestans, medido pela porcentagem de barbeiros infectados que se observou em cada um dos xenodiagnósticos dos cäes. A capacidade infectante dos cäes soropositivos foi aproximadamente constante ao longo da vida, e significativamente maior que a registrada para as crianças no presente estudo, e para os agrupamentos humanos pesquisados por outros investigadores. Assim sendo e considerando as altas freqüências de alimentaçäo no cäo que säo observados nas populaçöes pelo T. infestans, espera-se que o cäo contribua para o total de barbeiros infectados existentes nas áreas rurais da Argentina. Esta característica deveria ser suficiente para incriminar definitivamente os reservatórios caninos como um fator de risco para as pessoas residentes na mesma casa. A alta intensidade da parasitemia registrada entre os cäes na presente pesquisa poderia estar relacionada com a acentuada desnutriçäo característica dos cäes nas áreas rurais pobres da Argentina, o que poderia afetar a capacidade do hospedeiro para controlar a infecçäo