[Detection of Cryptosporidium parvum (Apicomplexan: Cryptosporidiidae) oocyst in Aulacomya ater specimen, extracted from to the coast Bio Bio Region, Chile]. / Detección de ooquistes de Cryptosporidium parvum (Apicomplexa: Cryptosporidiidae) en ejemplares de cholga Aulacomya ater, extraídas desde la costa de la Región del Bío Bío, Chile.

BACKGROUND: The bivalve Aulacomya ater (cholga), is one of the most consumed mollusks by the population. However, there is evidence of fecal water contamination caused by causes that affect the sea, increasing the probability of contamination by the Cryptosporidium parvum, which generates cryptosporidiosis in people. AIM: To determine the presence of C. parvum in cholga extracted from the Bio Bio Region (Chile). METHODS: Fifty-five cholgas were selected from a cultivation center and a natural extraction bank. These samples were processed in the laboratory and the presence of acid-alcohol resistant elements was evaluated. Positive samples were analyzed by direct immunofluorescence with anti-C. parvum antibody. RESULTS: 16.4% of the total samples were affected by the oocysts of C.parvum. CONCLUSIONS: For the first time we described C. parvum in A. ater from the Chilean coast, being this mollusk a possible vehicle for transmission of cryptosporidiosis to the population and their predatory animals. Furthermore, the presence of C. parvum reflects fecal water contamination on the evaluated coasts. We are currently monitoring other extraction areas for this mollusk.

Detección de ooquistes de Cryptosporidium parvum (Apicomplexa: Cryptosporidiidae) en ejemplares de cholga Aulacomya ater, extraídas desde la costa de la Región del Bío Bío, Chile / Detection of Cryptosporidium parvum (Apicomplexan: Cryptosporidiidae) oocyst in Aulacomya ater specimen, extracted from to the coast Bio Bio Region, Chile

Resumen Introducción: El bivalvo Aulacomya ater (cholga), es uno de los moluscos de mayor consumo en la población chilena. Sin embargo, existe evidencia de contaminación fecal hídrica provocada por los cauces que llegan al mar, aumentando la probabilidad de contaminación por Cryptosporidium parvum, el que genera criptosporidiosis en el ser humano. Objetivo: Determinar la presencia de C. parvum en cholgas extraídas desde la Región del Bío Bío (Chile). Material y Métodos: Se seleccionaron 55 cholgas provenientes de un centro de cultivo y de un banco natural de extracción. Estas muestras, fueron procesadas en el laboratorio y se evaluó la presencia de elementos ácido-alcohol resistentes. Las muestras positivas, se analizaron por inmunofluorescencia directa, con anticuerpo específicos contra C. parvum. Resultados: 16,4% del total de las muestras tenían ooquistes de C. parvum. Conclusiones: Por primera vez se describe C. parvum en A. ater provenientes de las costas chilenas, siendo este molusco un posible vehículo de transmisión de criptosporidiosis a la población y a sus animales depredadores. Además, la presencia de C. parvum refleja la contaminación fecal hídrica en las costas evaluadas. Actualmente estamos monitoreando otras zonas de extracción de este molusco.

Abstract Background: The bivalve Aulacomya ater (cholga), is one of the most consumed mollusks by the population. However, there is evidence of fecal water contamination caused by causes that affect the sea, increasing the probability of contamination by the Cryptosporidium parvum, which generates cryptosporidiosis in people. Aim: To determine the presence of C. parvum in cholga extracted from the Bio Bio Region (Chile). Methods: Fifty-five cholgas were selected from a cultivation center and a natural extraction bank. These samples were processed in the laboratory and the presence of acid-alcohol resistant elements was evaluated. Positive samples were analyzed by direct immunofluorescence with anti-C. parvum antibody. Results: 16.4% of the total samples were affected by the oocysts of C.parvum. Conclusions: For the first time we described C. parvum in A. ater from the Chilean coast, being this mollusk a possible vehicle for transmission of cryptosporidiosis to the population and their predatory animals. Furthermore, the presence of C. parvum reflects fecal water contamination on the evaluated coasts. We are currently monitoring other extraction areas for this mollusk.

Elemental sulfur-based autotrophic denitrification in stoichiometric S0/N ratio: Calibration and validation of a kinetic model.

The inclusion of S0 hydrolysis in a kinetic model of autotrophic denitrification has been recently proposed; however the model has not been calibrated or validated yet. Thus, a new methodology was developed and applied to calibrate and validate this kinetic model for the first time. An inoculum adapted from a poultry wastewater treatment plant at stoichiometric S0/NO3- ratio was used. The model was calibrated with batch data (initial nitrate concentrations of 50 and 6.25 mg NO3--N/L) at an S0/N ratio = 2.29 mg S/mg N and validated with seven different batch data. The sensitivity analysis showed that the most sensitive parameters are related to S0 hydrolysis. The kinetic model was successfully calibrated with the new methodology and validated, with Theil inequality coefficient values lower than 0.21. Thus, the proposed model and methodology were proved to be well suited for the simulation of elemental sulfur-based autotrophic denitrification in batch systems.

Riesgo de apnea obstructiva del sueño y nivel de actividad física y su asociación con riesgo cardiovascular elevado en adultos chilenos / Risk of obstructive sleep apnea and levels of physical activity and its association with elevated cardiovascular risk in chilean adults

Introducción: La apnea obstructiva del sueño (AOS) está asociada a alta morbi-mortalidad cardiovascular. Sujetos y métodos: Se seleccionaron 3.657 sujetos entre 30 y 74 años (x: 50,1 ±12,1 DS) de la Encuesta Nacional de Salud 2010. Se estimó el riesgo de AOS mediante una regla de predicción clínica (RPC) basada en las variables del Cuestionario STOP-Bang. Según puntaje se clasificaron en Riesgo BAJO (< 3), MEDIO (3-4) y ALTO (≥ 5) de AOS. El nivel de actividad física (NAF) fue clasificado en 3 niveles: Bajo, Moderado y Alto, según los resultados autorreportados con el cuestionario GPAQ. Para estudiar la asociación entre el riesgo de AOS y NAF con el RCV Alto/Muy Alto (≥ 10%, Framingham) construimos un modelo de regresión logística ajustado por sexo, edad, IMC, diabetes tipo 2, hipertensión arterial, colesterol total elevado, colesterol HDL bajo, triglicéridos elevados, nivel educacional, tabaquismo y horas de sueño autorreportadas. Resultados: 3.098 sujetos se clasificaron como riesgo de AOS: BAJO 1.683 (54,3%), MEDIO 1.116 (36%) y ALTO 299 (9,7%). El NAF fue evaluado en 3.570 sujetos, y clasificado como: Nivel Bajo 1.093 (30,6%), Moderado 705 (19,7%), y Alto 1.772 (49,6%). El RCV fue determinado en 3.613 sujetos, y 711 (19,7%) clasificaron como riesgo Alto /Muy Alto. El modelo de regresión muestra: riesgo MEDIO un OR = 1,75 (1,05-2,90; p = 0,03), riesgo ALTO un OR = 3,86 (1,85-8,06; p < 0,001). Para el NAF Bajo un OR = 1,14 (0,75-1,74; p = 0,525), NAF Moderado un OR = 1,18 (0,73-1,92; p = 0,501). Conclusión: El riesgo MEDIO y ALTO de AOS, pero no el NAF autorreportado, constituyen un factor de riesgo independiente para riesgo cardiovascular elevado.

Introduction: Obstructive sleep apnea (OSA) is associated with high cardiovascular morbidity and mortality. Subjects and methods: 3,657 subjects between 30 and 74 years-old ( x ¯: 50.1 ± 12.1 SD) from 2010 Chilean National Health Survey were selected. Risk of OSA was estimated using a clinical prediction rule (CPR) based on the variables of the STOP-Bang Questionnaire. According to their score they were classified as LOW (< 3), MEDIUM (3-4) and HIGH (≥ 5) risk of OSA. Their physical activity level (PAL) was classified into 3 levels: Low, Moderate and High, according to the self-reported results with the GPAQ questionnaire. To study the association between the risk of OSA and PAL with High / Very High CVR (≥ 10%, Framingham) we constructed a logistic regression model adjusted for sex, age, BMI, type 2 diabetes, high blood pressure, high total cholesterol, low HDL cholesterol, high triglycerides, educational level, smoking and self-reported sleep hours. Results: 3,098 subjects were classified as OSA risk: LOW 1.683 (54.3%), MEDIUM 1.116 (36%) and HIGH 299 (9.7%). The PAL was evaluated in 3,570 subjects and classified as: Low 1,093 (30.6%), Moderate 705 (19.7%), and High 1,772 (49.6%). The CVR was determined in 3,613 subjects, and 711 (19.7%) classified as High/Very High risk. The regression model shows: MEDIUM risk an OR = 1.75 (1.05 - 2.90, p = 0.03), HIGH risk an OR = 3.86 (1.85-8.06, p < 0.001). For the PAL Low an OR = 1.14 (0.75-1.74, p = 0.525), PAL Moderate an OR = 1.18 (0.73-1.92, p = 0.501). Conclusion: The MEDIUM and HIGH risk of OSA, but not the self-reported PAL, constitute an independent risk factor for high cardiovascular risk.

Niño quemado gran secuelado: perfil clínico y calidad de vida / Severe burns in children: clinical profile and quality of life

Las secuelas de quemaduras extendidas son causa de grandes complicaciones tanto a nivel físico como psicosocial en niños y adolescentes. Objetivo: Caracterización de la población con más de 2e por ciento de piel con secuelas por quemadura en Corporación de Ayuda al Niño Quemado, midiendo y comparando su calidad de vida según bienestar físico, bienestar psicológico, relación con los padres y autonomía, apoyo social y pares, ambiente escolar. Método: Se evalúa a través de cuestionario KIDSCREEN-27 a 29 niños de entre 8 a 18 años de edad, habiendo recibido rehabilitación integral, los que son comparados con resultados de niños sanos. Resultados. Dentro del grupo estudiado no hubo diferencias significativas entre género, edad, residencia, aunque si las hubo en cuanto a visibilidad de cicatrices. En el caso de comparación con muestra de población general sana, se evidenciaron diferencias de calidad de vida a favor de niños con quemaduras extendidas.

Introduction: The aftermath of extensive burns cause great complications both physical and psychosocial in children and adolescents. Objective: Characterization of the population over 25 percent of skin with aftermath burn in Assistance Corporation Burned Children, by measuring and comparing their quality of life by physical well, psychological, relationship with parents and autonomy, social support and peers, school environment. Methods: We evaluated through KIDSCREEN-27-29 children aged 8-18 years old having received comprehensive rehabilitation, the results being compared with healthy children. Results. Within the study group no significant differences between gender, age, residence, even if any in terms of visibility of scars. In the case of comparison with general population sample of healthy, were differences in quality of life for children with extensive burns.

Niño quemado gran secuelado. Perfil clínico y calidad de vida / Child burned great aftermath. Clinical profile and quality of life

Burns are an important cause of morbidity in children. The medical advances in acute trauma care have led to an increase in the number of children with extense area of burned skin, whose sequelaes are cause of complications along their growth. Objective. To characterize population with over 25% of sequelae burn skin at the COANIQUEM Rehabilitation Center, Santiago. Additionally to measure their quality of life and suggest interventions to improve medical attention. Methods. Quantitative, non experimental, descriptive, comparative study. Results. A sample of 59 children were identified as having post-traumatic burned on more than 25% of total body surface. 47% of them were men and 53% female. Most them (64%) were patients who lived outside the capital city, Santiago. 54% was burned during the ages between to 2 to 6 years old. 42% was burned with fire and 56% by scalding. Half the patients were admitted to rehabilitation before 2 month after injury. 64% has good adherence to treatment and a regular follow-up. A group of 29 KIDSCREEN-27 survey was analyzed. There were no significant differences between gender, age, residence or visibility scars. Conclusions. Epidemiology found in children with severe burn sequelae is consistent with findings from literature. Quality of life outcomes are similar to general population. The concept of pediatric major burn sequela is established for future research in this area. (AU)

Evaluación médica previa a la práctica deportiva para deportistas aficionados y de nivel competitivo / Pre - participation screening in sports for leisure and competitive athletes

La actividad física y el deporte reducen la mortalidad general y cardiovascular, pero durante la práctica de ejercicio aumenta el riesgo de muerte súbita que puede ser la primera manifestación de una enfermedad cardiovascular no diagnosticada en deportistas previamente asintomáticos. Las causas de muerte súbita difieren según la edad, en los menores de 35 años se debe a patologías congénitas o hereditarias y en los mayores de esta edad a enfermedad coronaria. En el presente artículo se analizan las causas más frecuentes de muerte súbita, así como los protocolos de evaluación médica previa a la práctica de actividad física o deporte propuestos en la literatura para su prevención en deportistas de diferentes edades y nivel de actividad, desde el competitivo de alto rendimiento hasta el recreativo por salud, y utilización del tiempo libre.

The physical activity and sports decrease cardiovascular and all cause mortality, but during exercise increase risk of sudden death is often the first manifestation of underlying cardiovascular disease in previously asymptomatic athletes. The cause of sudden death is different depending on age, in young people (< 35 years) are genetic or congenital cardiovascular abnormalities and in adult people (> 35 years) is coronary arteries disease. This article is a review of sudden death more habitual causes and the protocol of pre-participation in physical activity and sports medical evaluation that exists in the medical literature in sudden death prevention for athletes of all ages and that participate in leisure and competitive sports.

Procedimientos intervencionales guiados por ultrasonido en radiología musculoesquelética / Ultrasound guided interventional procedures in musculoskeletal radiology

Ultrasound is a useful diagnostic modality to study many structures such as subcutaneous tissue, tendons, muscles, joints, and nerves. It has low cost, wide availability and high resolution. These advantages make ultrasound a good modality in interventional procedures like soft tissue tumors biopsy, aspiration of cysts and other collections, and also in treating symptomatic calcifications like deposition of hidroxiapatite crystals in the rotator cuff, among other indications. Our objetive is to present the experience of the authors in performing musculoskeletal interventional procedures by ultrasound.

El ultrasonido es una modalidad imaginológica útil para el estudio de múltiples estructuras, tales como tejidos subcutáneos, tendones, músculos, articulaciones y nervios. Tiene un bajo costo, amplia disponibilidad y alta resolución. Estas ventajas hacen del ultrasonido una excelente modalidad en procedimientos intervencionales tales como biopsias de tejidos de partes blandas, aspiración de quistes y otras colecciones y también en el tratamiento de calcificaciones sintomáticas, tales como depósitos de cristales de hidroxiapatita de calcio en el manguito rotador. Este artículo desea mostrar la experiencia de los autores en la realización de procedimientos intervencionales musculoesqueléticos guiados por ultrasonido.

Sonoelectrochemical treatment of water polluted with trichloroacetic acid: from sonovoltammetry to pre-pilot plant scale.

The sonoelectrochemical treatment of aqueous solutions of trichloroacetic acid (TCAA) has been scaled-up from the voltammetric analysis to pre-pilot stage. The degradation in absence of ultrasound field has yield to a poor performance which has been improved in presence of ultrasound. The sonovoltametry study has provided the range of potentials and/or current densities to be used with the lowest current efficiency penalty. Sonoelectrolyses at batch scale (carried out with a horn-transducer 24 kHz positioned at about 3 cm from the surface of the electrode) achieved little improvement in the degradation. However, when a specifically designed sonoelectrochemical reactor (not optimized) was used during the scale-up, the presence of ultrasound field provided better results (fractional conversion 97%, degradation efficiency 26%, selectivity 0.92 and current efficiency 8%) at lower ultrasonic intensities and volumetric flow.

Uso de concentrado autologo rico en factores de crecimiento en la reconstruccion del ligamento cruzado anterior / Using AutoLogo concentrate rich in growth factors in the reconstruction of the anterior cruciate ligament

Hipotesis: La aplicación de factores de crecimiento obtenidos de concentrado plaquetario autólogo al injerto al efectuar la reeconstrucción de ligamento. cruzado anterior en deportistas, afecta positivamente el proceso de remodelación del injerto utilizado. Objetivo: Determinar el efecto que tiene en el proceso de remodelación del injerto, la aplicación de factores de crecimiento obtenidos de concentrado plaquetario autólogo al efectuar la reconstrucción de ligamento cruzado anterior en deportistas. Diseño del estudio: Prospectivo, clínico randomizado, con grupo control y ciego simple. Método: Se realiza en forma prospectiva el análisis de 50 reconstrucciones de LCA en 50 pacientes, todas ellas realizadas por el mismo equipo quirúrgico. Al grupo A , además de efectuar la reconstrucción de LCA, se adiciona Concentrado Plaquetario Autólogo, desarrollando una técnica de aplicación que permite estandarizar la dosis de concentrado empleada y evitar la pérdida de este en el paso del injerto a través de los túneles óseos. Los pacientes del grupo A se sometieron a estudio de resonancia magnética en forma seriada a los 3,4, 5, 6, 7, 8 Y 9 meses postoperatorio. El grupo control el estudio se realizó a los 3, 4, 6, 7,9,10 ,11 ,12 meses. La evaluación de las placas obtenidas fue realizada por un solo radiólogo en forma ciega, ya que desconocía: tiempo de evolución, técnica quirúrgica empleada o si se aplicó AGE analisis estadístico: Comparación de Grupos: T-Student (p-value <5%) Y Prueba F (p-value <5%). Modelo cuadrático predictivo de tiempo de maduración (homogeneidad) para determinar el tiempo de remodelación y maduración en cada grupo. Resultados: El puntaje promedio de maduración al momento de la resonancia magnética, entregado por el radiólogo en el grupo A fue de 1,14 y en el grupo B (control) fue de 3,25. Ambos grupos son comparables según sexo y edad (p-value <5%). El tiempo de maduración del segmento intraarticular, en el grupo A (co...

Sexual dysfunction and related risk factors in a cohort of middle-aged Ecuadorian women.

Sexuality is a complex phenomena that can be affected by psychological and physiological influences, among them the climacteric. The present study aimed to assess the incidence of sexual dysfunction and related risk factors in a cohort of low socioeconomic middle-aged Ecuadorian women. For this, 385 healthy sexually active women between 40 and 65 years old accompanying patients being attended at the Enrique C. Sotomayor Obstetrics and Gynecology Hospital of Guayaquil, Ecuador were asked to take part in the study. Subjects were surveyed using DSM IV criteria to assess sexual dysfunctions and record coital frequency over the past 12 months. Mean age of the sample was 47 +/- 5.6 years (median: 46), 43.1% were postmenopausal and a 17.9% of them were on hormone therapy (HT). A total of 53.5% maintained at least four sexual intercourses per month. Masculine erectile dysfunction and premature ejaculation was present in 21.3% and 59.2%, respectively. Female sexual dysfunction was present in a 78.4% of women included in the study. Desire dysfunction was the most frequent disorder (62.6%). The incidence of sexual dysfunction increased from 71.6% in the 40 - 44 year group, to 92.3% in the 60 - 64 year group (p < 0.05). The risk of sexual dysfunction was increased 7.6-fold when male erectile dysfunction was present (CI: 1.7 - 33.8), 5.8 in cases of premature ejaculation (CI: 2.9 - 11.3), 2.9 by marital status (married) (CI: 1.5 - 5.7) and 4.1 by antidepressant therapies (CI: 1 - 15.7), whereas schooling > or =12 years, having only one sexual partner and > or =4 intercourses per month were factors that decreased sexual dysfunction risk. In conclusion, the incidence of sexual dysfunction in this low socioeconomic Ecuadorian women cohort was higher than expected. Male sexual dysfunctions, marital status and antidepressant use were the most important predicting risk factors.

Ciruguía reparadora de la válvula aórtica bicúspide insuficiente / Valve repair surgery for incompetent bicuspid aortic valves

Background: Surgical valve repair is a good alternative for correction of incompetent bicuspid aortic valve. Aim: To report the early and late surgical, clinical and ecochardiographic results of surgical repair of incompetent bicuspid aortic valves. Patients and methods: Retrospective review of medical records of 18 patients aged 19 to 61 years, with incompetent bicuspid aortic valve in whom a valve repair was performed. Four patients had infectious endocarditis and 17 were in functional class I or II. Follow up ranged from 3 to 113 months after surgery. Results: A triangular resection of the prolapsing larger cusp, which included the middle raphe, was performed in 17 cases; in 13 of these, a complementary subcommisural annuloplasty was performed. In the remaining case, with a perforation of the non-coronary cusp, a pericardial patch was implanted; this procedure was also performed in 2 other cases. In 3 cases large vegetations were removed. Postoperative transesophageal echocardiography showed no regurgitation in 11 patients (62percent) and mild regurgitation in 7 (38percent). There was no operative morbidity or mortality. There were no deaths during the follow-up period. In 3 patients (17percent) the aortic valve was replaced with a mechanical prosthesis, 8 to 108 months after the first operation. Reoperation was not needed in 93percent±6,4percent at 1 year and 85percent±9,5percentat 5 years, these patients were all in functional class I at the end of the follow-up period. 60percen had no aortic regurgitation, 20percent had mild and 20percent moderate aortic regurgitation on echocardiographic examination. A significant reduction of the diastolic diameter of the left ventricle was observed, but there were no significant changes in systolic diameter or shortening fraction. Conclusions: Surgical repair of incompetent bicuspid aortic valves has low operative morbidity and mortality and has a low risk of reoperation.

Cirugía valvular reparadora en endocarditis infecciosa / Valve repair surgery in infectious endocarditis

Background: Valve replacement has been the treatment of choice for patients with valvular complications of infectious endocarditis (IE). However, excellent results with valve repair allowed it to become a new therapeutic alternative for these patients. Aim: To evaluate the results of valve repair in patients with valvular complications of IE. Patients and Methods: From January 1991 to December 2000, 14 patients with valvular complications of IE underwent valve repair. Mean age was 37.9 ± 14.9. Results: New York Heart Association (NYHA) class was 2.8 ± 0.9. IE was located in the aortic in 6 (42 percent), in the mitral valve in 4 (29 percent) and in both valves in 4 cases (29 percent). Surgical indication was hemodynamic in 50 percent of the cases, echocardiographic in 29 percent and septic in 21 percent. Five aortic valves were bicuspid, 3 mitral valves were myxomatous and the rest were normal. The most common septic lesions were vegetations and leaflet perforations. A total of 23 aortic and 21 mitral valve repair procedures were performed. There were no deaths. Only 1 patient had a surgical complication (renal failure and prolonged mechanical ventilation). Follow-up was 100 percent complete. There was not late mortality. One patient with bone marrow aplasia required reoperation for a new episode of IE 19 months later. At the end of the follow-up NYHA class was 1.3 ± 0.6 and echocardiography showed a mild or absence of valve regurgitation in most patients. Conclusions: Valve repair surgery in IE has good results, with advantages over valve replacement (Rev MÚd Chile 2004; 132: 307-15).

Resultados alejados de la cirugía reparadora de la insuficiencia mitral degenerativa / Long-term results of repair surgery of degenerative mitral insufficiency

Background: Mitral valve repair is probably the procedure of choice for the surgical treatment of degenerative mitral insufficiency. Aim: To evaluate the late results of mitral valve repair in degenerative mitral insufficiency. Patients and method: The records of 88 patients who underwent mitral valve repair for degenerative mitral insufficiency from December 1991 through June 2002 were reviewed. Mean age was 59.9 years (range 22 to 82). At least moderate mitral insufficiency was present in every patient. Mean left atrial diameter was 55 mm and mean end diastolic and end systolic left ventricular diameters were 61 and 37 mm respectively. Results: The most common underlying lesion was ruptured chordae tendineae (66%) and posterior leaflet prolapse (68%). The surgical procedure most frecuently performed was quadrilateral resection of the posterior leaflet (68%). A Carpentier-Edwards ring was placed in 97% of patients. An associated procedure was performed in 34%. Operative mortality was 2.3%. A complete follow up was obtained in 93% of cases with a mean of 54±36 months. Overall survival rate was 98% at one year, 88% at 5 and 82% at 10 years. Free of cardiac death rates were 94% at 5 and 89% at 10 years. Only 2 patients were reoperated during follow up, resulting in a 98% reoperation free rate follow up. Functional class improved in all patients at the end of follow up. Late echocardiographic evaluation showed absent or minimal mitral regurgitation in 83% and mild mitral regurgitation in 17%. Conclusion: Good late results have been obtained with mitral valve repair, avoiding the inconveniencies of prosthetic replacement. Therefore, mitral valve repair should be the procedure of choice to treat degenerative mitral insufficiency (Rev Méd Chile 2003; 131: 1355-64).

Weight change in old age and its association with mortality.

OBJECTIVES: Previous studies of weight change and mortality in older adults have relied on self-reported weight loss, have not evaluated weight gain, or have had limited information on health status. Our objective was to determine whether 5% weight gain or loss in 3 years was predictive of mortality in a large sample of older adults. DESIGN: Longitudinal observational cohort study. SETTING: Four U.S. communities. PARTICIPANTS: Four thousand seven hundred fourteen community-dwelling older adults, age 65 and older. MEASUREMENTS: Weight gain or loss of 5% in a 3-year period was examined in relationship to baseline health status and interim health events. Risk for subsequent mortality was estimated in those with weight loss or weight gain compared with the group whose weight was stable. RESULTS: Weight changes occurred in 34.6% of women and 27.3% of men, with weight loss being more frequent than gain. Weight loss was associated with older age, black race, higher weight, lower waist circumference, current smoking, stroke, any hospitalization, death of a spouse, activities of daily living disability, lower grip strength, and slower gait speed. Weight loss but not weight gain of 5% or more was associated with an increased risk of mortality that persisted after multivariate adjustment (Hazard ratio (HR) = 1.67, 95% CI = 1.29-2.15) and was similar in those with no serious illness in the period of weight change. Those with weight loss and low baseline weight had the highest crude mortality rate, although the HR for weight loss was similar for all tertiles of baseline weight and for those with or without a special diet, compared with those whose weight was stable. CONCLUSIONS: This study confirms that even modest decline in body weight is an important and independent marker of risk of mortality in older adults.

Methods for analyzing health care utilization and costs.

Important questions about health care are often addressed by studying health care utilization. Utilization data have several characteristics that make them a challenge to analyze. In this paper we discuss sources of information, the statistical properties of utilization data, common analytic methods including the two-part model, and some newly available statistical methods including the generalized linear model. We also address issues of study design and new methods for dealing with censored data. Examples are presented.

Gamma delta T-cell function in pathogenesis of cerebral malaria in mice infected with Plasmodium berghei ANKA.

Mice depleted of gammadelta T cells by monoclonal antibody treatment and infected with Plasmodium berghei ANKA did not develop cerebral malaria (CM). In striking contrast, delta0/0 mice infected with P. berghei developed CM despite their gammadelta T-cell deficiency. gammadelta T cells appear to be essential for the pathogenesis of CM in mice having experienced normal ontogeny but not in mice genetically deprived of gammadelta T cells from the beginning of life.

Factors Associated With Hospital Utilization in the Elderly: From the Cardiovascular Health Study.

OBJECTIVE: Analyze clinical, accepted biochemical, physiologic, and socioeconomic risk factors and correlate them with hospital utilization in an elderly population. DESIGN: Prospective, observational study in a defined, randomly recruited population. PARTICIPANTS: 5201 Medicare participants enrolled in the Cardiovascular Health Study (CHS). METHODS: Medicare recipients were randomly assigned to participate in an observational study. Baseline data were compared to hospital admissions and days of hospitalization over four years. DATA ANALYSIS: Data were grouped by type of risk factor and analyzed by Tobit analysis and logistic regression. RESULTS: Baseline variables associated with hospital use (p is less than 0.0001) were history of CHF, stroke, angina, hypertension, ln (timed walk), ln (blocks walked/week), age, gender, and clinic site. Factors not entering the model (p is greater than 0.05) were income, education, smoking, diabetes, weight, dietary fat, marital status, depression, and measures of mental function. CONCLUSIONS: In the elderly, existing health status is the major determinant of hospitalization and overwhelms many classic "risk factors" for morbidity.

Vaccination against persistent viral infection exacerbates CD4+ T-cell-mediated immunopathological disease.

Lymphocytic choriomeningitis virus (LCMV) infection of normal mice results in a fatal immunopathologic meningitis mediated by CD8+ cytotoxic T lymphocytes (CTL). We have previously shown that female beta2-microglobulin-deficient (beta2m-/-) mice, which are also deficient in CD8+ T cells, are susceptible to LCMV-induced immune-mediated meningitis, characterized by significant weight loss and mortality. This LCMV disease in beta2m-/- mice is mediated by CD4+ T lymphocytes. Our previous studies have also demonstrated that male beta2m-/- mice are less susceptible than female beta2m-/- mice to LCMV-induced, immune-mediated mortality and weight loss. In this report, we show that vaccination of male beta2m-/- mice enhances immunopathology following intracranial infection with LCMV. We observed increased production of gamma interferon (IFN-gamma), an increase in CD4+ CTL precursor frequency, and an increased frequency of IFN-gamma-producing cells from spleen cells of vaccinated male beta2m-/- mice. Vaccinated male beta2m-/- mice also had significantly increased inflammation in the cerebrospinal fluid (CSF), characterized by a large CD4+ T-cell infiltrate. CSF cells from vaccinated mice showed increased production of IFN-gamma on day 7 postchallenge. Neither vaccinated nor control beta2m-/- mice were able to clear virus, and the two groups had similarly high levels of virus early after infection. These results suggest that the magnitude of the early immune response is more important than the level of virus in the brain in determining the outcome of immunopathology in beta2m-/- mice. We show here that vaccination can increase CD4+ T-cell-dependent immunopathology to a persistent viral infection.