Nefrectomía radical con trombectomía de vena cava: 20 años de cirugías por tumor renal / Vena cava thrombectomy in kidney cancer. Report of 32 nephrectomies

BACKGROUND: Vena cava (VC) involvement in kidney tumors occurs in 4 to 10% of cases, and is associated with a higher mortality. Nephrectomy with thrombectomy of the VC, performed by a multidisciplinary team, improves survival. Aim: To report a series of consecutive nephrectomies with caval thrombectomy performed in an academic center. PATIENTS AND METHODS: We report 32 patients with cT3b and 3c renal tumors, who underwent radical nephrectomy with VC thrombectomy between 2001 and 2021. A descriptive analysis of clinical, surgical and pathological variables was performed. Overall survival (OS) and cancer-specific survival (CSS) was calculated using Kaplan-Meier curves. Results: The mean tumor size was 9.7 cm. According to Mayo classification 3/32 (9%) patients had a type I thrombus, 10/32 (31%) had a type II thrombus, 8/32 (25%) had a type III thrombus, and 5/32 (16%) had a type IV thrombus. The mean bleeding was 2000 cc. There was one intraoperative death. Nineteen percent of patients had complications >= 3 according to Clavien-Dindo classification. Reoperations occurred in 9%. Pre and postoperative creatinine levels were 1.17 and 1.91 mg/dl respectively (p < 0.01). Pre and postoperative Hematocrit levels were 47.9 and 31% respectively (p = 0.02). Sixty six percent of tumors were clear cell renal cancer, 9% were papillary and 3% were chromophobic. Mean OS was 10 months. Two-year SCE was 40%. CONCLUSIONS: Our results are similar to those reported elsewhere. Despite being an unusual pathology, the surgical technique has been improving, thanks to the multidisciplinary work of urologists and surgeons.

Tabaquismo y tumores mayores de 2 centímetros son predictores de mortalidad en pacientes sometidos a nefro-ureterectomías por carcinoma de urotelio alto / Prognostic factors in patients with upper urinary tract urothelial carcinoma undergoing nephro-ureterectomy

BACKGROUND: Upper urinary tract urothelial carcinoma (UTUC) represents 5-10% of urothelial carcinomas. It is managed with nephroureterectomy (NUR); however, kidney-sparing techniques are growingly used. AIM: To report the results of a 20-year series of NUR conducted in an academic center. Patients and Methods: Review of clinical and pathological characteristics of patients undergoing NUR between 1999 and 2020. Patients were followed for 63 months. Global survival curves (OS) and mortality predictors were established through Cox regression. RESULTS: We included 90 patients with a median age of 68 years undergoing NUR, of whom 68 (75%) had a pelvic tumor and 22 (25%) had a proximal ureteral tumor. A laparoscopic NUR was performed in 60 patients (66%). Thirty-three patients (37%) had tumors confined to the urothelium (pTa), penetrating the lamina propria (pT1) or carcinoma in situ (CIS), 10 patients (11%) had a tumor spreading to the muscle layer (pT2) and 47 (52%) had a tumor spreading to nearby organs (pT3 / T4). Average tumor size was 3.69 cm, nodal disease (pN) was present 12 patients (13%). Twelve patients (13%) received adjuvant chemotherapy. A higher mortality was observed among smokers (Hazard ratio (HR) 8.79, 95% confidence intervals (CI) 1.5-49.0, p = 0.01), patients with tumors classfied as pT≥ 2 (HR 1.09, 95% CI 0.01-1.0, p = 0.04) and those with tumors larger than 2 cm (HR 14.79, CI 95% 1.5-272, p = 0.01). CONCLUSIONS: Smoking patients, those with invasive tumors (T2-T4) and greater than 2 cm have higher mortality. Therefore, they should not be candidates for conservative management.

Caso clínico. Ultrasonografía pulmonar en paciente Covid-19 en hospital de baja complejidad / Lung ultrasound in covid-19 patient in a low complexity hospital: Case report

In the current SARS-CoV-2 pandemic, it has become imperative to develop instruments for lung evaluation that are fast and efficient; in this sense, lung ultrasonography is presented as an effective instrument that can be extrapolated to low complexity centers that allow to guide management of Covid-19 patients.

En la pandemia por SARS-CoV-2 que vivimos actualmente se ha hecho imperante desarrollar instrumentos para la evaluación pulmonar que sean rápidos y eficientes, en este sentido la ultrasonografía pulmonar se presenta como un instrumento eficaz extrapolable a centros de baja complejidad que permitan guiar manejo de pacientes Covid-19.

Masas renales pequeñas: predictores de malignidad en una serie de 10 años / Small renal masses: analysis of 152 cases

Background: Small renal masses (SRM) are defined as complex organ-confined solid or cystic lesions < 4 cm. Up to 20% of these can be benign. A conservative management with active surveillance can be done in some patients. However, it is difficult to identify patients with a higher risk of malignancy. Aim: To characterize the clinical, radiological and histopathological aspects of patients with SRM, analyzing predictive factors for tumor aggressiveness. Material and Methods: Retrospective analysis of a cohort of patients undergoing partial or total nephrectomy for renal tumors between 2006 and 2016. All tumors of 4 cm or less were included. Four histological groups were defined: benign, favorable, intermediate and unfavorable. Two categories of risk were also defined: low and high. Preoperative clinical and radiological variables of these patients were analyzed. Results: Data of 152 patients were analyzed. Six percent had a benign histology, and the majority was of intermediate risk (74%). According to histological type, clear cell carcinoma was the most common type (74%). Three percent were benign angiomyolipomas. No malignancy predictive variable was identified. Conclusions: In these patients, the percentage of benign SRM was low. No variable that could predict the presence of a benign or malignant lesion in the definitive biopsy was identified.

Tratamiento quirúrgico de macroglosia grave en el síndrome de Beckwith-Wiedemann: reporte de un caso / Surgical treatment of macroglossia in Beckwith-Wiedemann syndrome: case report

El síndrome de Beckwith-Wiedemann es una enfermedad congénita, poco frecuente, caracterizada por presentar macroglosia, defectos de la pared abdominal, hemihipertrofia, onfalocele, hipoglucemia neonatal, hernia umbilical, hepatomegalia, anomalías cardíacas, entre otros. La macroglosia se presenta en el 90% de los casos y genera problemas en la masticación, deglución, fonación y respiración, que ocasionan un cierre de la vía aérea superior. La opción terapéutica de elección es la glosectomía parcial. Se presenta a un paciente pediátrico de dos meses de nacido, con síndrome de Beckwith-Wiedemann y obstrucción de la vía aérea por macroglosia grave. En los antecedentes médicos, se reportaron cardiopatías congénitas, comunicación interauricular, conducto arterioso persistente, epilepsia sintomática, falla renal, hipoglicemia, traqueotomía y gastrostomía por el colapso de la vía aérea y disfagia. Se realizó la técnica quirúrgica de glosectomía de reducción anterior, con resultados favorables.

Beckwith-Wiedemann syndrome is a rare congenital condition, characterized by presenting macroglossia, defects of the abdominal wall, hemihypertrophy, omphalocele, neonatal hypoglycemia, umbilical hernia, hepatomegaly, cardiac abnormalities, among others. Macroglossia occurs in 90% of cases, causing a problem in chewing, swallowing, phonation and breathing, resulting in a closure of the upper airway. The therapeutic option of choice is partial glossectomy. We present a 2-month-old pediatric patient with Beckwith-Wiedemann syndrome and area blockage due to severe macroglossia; in the medical history, congenital heart disease, interatrial communication, persistent ductus arteriosus, symptomatic epilepsy, renal failure, hypoglycemia, tracheotomy and gastrostomy, due to airway collapse and dysphagia. It was performed an anterior tongue reduction surgery as a surgical treatment with favorable results.

Score genético predice agresividad del cáncer de próstata / Genetic score predicts aggressiveness of prostate cancer

Establecer un score genético utilizando los polimorfismos de nucleótido único (SNPs) del gen que codifica para Ribonucleasa L (RNASEL)y regiones cromosómicas 8q24 y 17q12-24 en combinación con el antígeno específico de la próstata (PSA) para predecir la agresividad del cáncer de próstata (CaP). Pacientes y métodos: hombres con CaP tratados con prostatectomía radical. Se analizaron variables clínicas y patológicas: edad al diagnóstico, PSA al diagnóstico, el volumen tumoral (TV) y extensión extracapsular (ECE) según el TNM (tumour, node and metastasis) (ECE ≥T3) y score de Gleason. Desarrollamos un modelo de puntaje genético usando regresión logística multivariable. Resultados: se incluyeron 86 pacientes sometidos a prostatectomía radical. Edad promedio fue de 62 ± 7,5 años. El promedio de PSA fue de 11,3 ± 10,6 ng/mL. Treinta y un pacientes (36 por ciento) tuvieron ECE. La mediana del TV fue de 3,8 cc. Un PSA ≥ 10 ng/mL se asoció con una mayor tasa de ECE (p <0,05) y TV más alto (p = 0,032). En el análisis univariable, los pacientes con > 1 SNP tienen mayor riesgo de ECE que los pacientes con ≤ 1 SNP (42 por ciento vs. 10,5 por ciento, p = 0,01), y los pacientes con ≥ 3 SNP tienen más TV que los pacientes con <3 SNP (60 por ciento vs. 32 por ciento, p = 0,015). Se crearon dos modelos de riesgo usando el número de SNP y PSA ≥ o <10 ng/mL para predecir ECE (sensibilidad 67 por ciento y especificidad 84 por ciento) y TV (sensibilidad 59 por ciento y especificidad 70 por ciento). Conclusiones: El score genético presentado en este estudio es una herramienta novedosa para predecir indicadores de agresividad del CaP, como ECE y TV.(AU)

To establish a genetic score using SNPs (from RNAsel and chromosomal regions 8q24 and 17q12-24) in combination with Prostate Specific Antigen (PSA) at diagnosis to predict aggressiveness of PCa (tumor volume (TV) and extracapsular extension (ECE)). Patients and methods: Men with PCa diagnosed by needle biopsy and treated with radical prostatectomy (RP). Clinical and pathological variables such as age at diagnosis, PSA at diagnosis, TV, extension of tumor according TNM (ECE ≥T3) and Gleason score where analyzed. We developed a genetic score model using Multivariate Logistic Regression. Results: We included 86 patients who underwent RP. Mean age 62 ± 7.5 years. Mean PSA was 11.3 ± 10.6 ng/mL. Thirty-one patients (36 percent) had ECE. Median TV was 3.8 cc. PSA ≥ 10 ng/mL was associated with increased rate of ECE (p <0.05) and higher TV (p = 0.032). In univariate analysis, patients with more than 1 SNP had a greater risk of ECE than patients with ≤ 1 SNP (42 percent vs. 10.5 percent, p = 0.01), and patients with ≥ 3 risk SNPs had more TV than patients with <3 SNPs risk (60 percent vs. 32 percent, p = 0.015). Two models of risk using the number of SNPs and PSA ≥ or <10 ng/mL to predict ECE (sensitivity 67 percent and specificity 84 percent) and TV (sensitivity 59 percent and specificity 70 percent) were created. Conclusions: Genetic score usingdescribed SNPs and preoperative PSA can predict aggressiveness of PCa, which would be useful to define a management with more information at diagnosis especially in localized cancers.(AU)

Estilo de vida y agresividad del cáncer de próstata / Lifestyle and aggressiveness of prostate cancer

El objetivo de este estudio fue establecer una asociación entre diversas variables demográficas y epidemiológicas con la agresividad del cáncer de próstata (CaP). Métodos: pacientes diagnosticados con CaP respondieron una encuesta que incluye el nivel de educación, los factores de riesgo cardiovascular (FRCV), los antecedentes familiares (HF) de CaP, consumo de alcohol, tabaquismo y otros. Se utilizó análisis univariado y multivariado (AMV) para establecer si los factores mencionados anteriormente afectan las variables asociadas con la agresividad del CaP, como la edad al momento del diagnóstico, el índice de Gleason, los márgenes positivos (MP) y las metástasis óseas (MO), entre otras. Resultados: se incluyeron ciento setenta y dos hombres en el análisis. Los pacientes con HF fueron diagnosticados a edades más tempranas que los pacientes sin HF (55,73 vs 66,45 años, p = 0,0001). Los pacientes que beben tienen un mayor número de MP que los pacientes que no (15 vs 4 pacientes, p = 0,04). El AMV mostró que los pacientes que consumen alcohol y los que fuman (activos o suspendidos) tuvieron un mayor riesgo de MP (OR = 4,45 y 4,1, IC 95 por ciento 1,16-17,07 y 1,14-14,72, respectivamente, ambos p <0,05). Los pacientes con mayor nivel de educación presentaron un mayor riesgo de CaP confinado (OR = 3,42, IC 95 por ciento 1,392-8,434, p = 0,007). Conclusiones: los pacientes que consumen alcohol, fuman y tienen un menor nivel de educación presentaron un mayor riesgo de desarrollar CaP agresivo. (AU)

The aim of this study was to establish an association between various demographic and epidemiological variables with aggressiveness of prostate cancer (PCa). Methods: Patients diagnosed with PCa, answered a survey that include level of education, cardiovascular risk factors (CVRF), family history (FH) of PCa, alcohol intake, smoke and others. Univariate and multivariate analysis (MVA) were used to establish whether the factors mentioned above affect variables associated with aggressiveness of PCa such as: age at diagnosis, Gleason score, positive margins (PM), and bone metastasis (BM). Results: One hundred and seventy two men were included in the analysis. Patients with FH had cancer diagnosed at younger ages (55.73 years to FH vs 66.45 years to no FH, p = 0.0001). Patients who drink had higher number of PM than patients who did not (15 vs 4 patients, p= 0.04). MVA showed that patients who consumed alcohol and patients who smoked (active or suspended) had an increased risk of PM (OR= 4.45 and 4.1, 95 percent CI 1.16-17.07 and 1.14-14.72, respectively, both p<0.05). Patients with higher level of education presented an increased risk of confined PCa (OR= 3.42, 95 percent CI 1.392-8.434, p= 0.007). Conclusions: Patients who consume alcohol, smoke and have lower level of education presented a higher risk of developing aggressive PCa. (AU)

Biometría del cráneo y sistema ventricular cerebral fetal: tablas de normalidad a través de pruebas no paramétricas

Objetivos: Realizar tablas de referencia a través de estadística no paramétrica para definir en percentiles los rangos de normalidad del diámetro biparietal, la circunferencia cefálica, el atrio ventricular cerebral, la cisterna magna, el cavum septum pellucidum y los ventrículos laterales, según recomendaciones de la International Society of Ultrasound in Obstetrics and Gynecology de evaluación y medida. Métodos: Estudio transversal realizado desde enero 2014 a enero 2016. Se evaluaron 1004 embarazadas normales, en diferentes edades gestacionales, y de manera previamente estandarizada se midieron las estructuras mencionadas. El análisis estadístico se realizó con el software libre PAST 3.04 para la organización de los datos de cada edad gestacional en percentiles. Se presentaron en gráficos tipo nomogramas y en modelo de regresión polinómica de primer orden. Cada gráfico fue evaluado con significancia estadística con P<0,05. Resultados: Las estructuras intracraneales pudieron medirse en su totalidad en 864 casos (86 % de los exámenes). Los diámetros biparietal y las circunferencias cefálica pudieron obtenerse en todos los casos, se observó un crecimiento directamente proporcional a la edad gestacional (P< 0,05). La medida del atrio ventricular resultó estable lo largo del embarazo. Se presentan las medidas de la cisterna magna, del cavum septum pellucidum y de los ventrículos laterales. Conclusiones: Los rangos de normalidad se representaron en tablas para correcto uso clínico y de investigación, no difieren de investigaciones previas realizadas en otros países. Se presentan valores de referencia utilizables en la consulta prenatal, a través de estadística no gaussiana.

Objectives: To carry out reference tables through non-parametric statistics to define in percentile ranges of normality of the biparietal diameter, head circumference, the cerebral ventricular atrium, the cisterna magna, cavum septum pellucidum, and the lateral ventricles, according to the recommendations of the International Society of Ultrasound in Obstetrics and Gynecology of evaluation and measurement. Methods: A cross-sectional study was carried out from January 2014 to January 2016; 1004 normal pregnant women, in different gestational ages, were evaluated, and the mentioned structures, previously standardized, were measured. The statistical analysis was performed with the FOSS PAST 3.04 for the organization of the data at each gestational age, in percentiles. They arose in graphic type nomograms and first-order polynomial regression model. Each graphic was evaluated with statistics significance with P < 0.05. Results: The intracranial structures could be measured entirely in 864 cases (86% of the tests). Biparietal diameter and head circumferences were obtained in all cases; it was observed a directly proportional growth to gestational age (P < 0.05). The measurement of the ventricular Atrium was stable throughout the pregnancy. Measures of the cisterna magna, cavum septum pellucidum and of the lateral ventricles are represented. Conclusions: Normal ranges are represented in tables for correct clinical use and research, the results are not different from previous research conducted in other countries. Usable reference values, in the prenatal consultation, through non-Gaussian statistics are presented.

Infección por Virus Zika en el embarazo / Virus Zika infection in pregnancy

La infección viral por Zika se ha diseminado desde fechas recientes en las Américas. Venezuela no ha escapado a la emergente enfermedad, y al ser una población rica en población de mosquitos Aedes Aepypti y sin memoria inmunológica al virus nos hace muy susceptibles a tener una amplia distribución de la infección en muy corto tiempo, similar a lo ocurrido con otras enfermedades transmitidas por mosquitos como el Dengue y el Chikungunya. Las mujeres embarazadas tienen un potencial de infección y de transmisión materno fetal mucho mayor por los cambios fisiológicos en sus sistemas inmunológicos, y la transmisión vertical del virus implica un riesgo para que el feto tenga compromiso en su anatomía en diferentes regiones, principalmente afectando el SNC. En este trabajo se describe la problemática, métodos de diagnóstico materno y fetal de las complicaciones y resumen de protocolos sugeridos por instituciones de salud mundiales, orientadas a médicos, obstetras y otros prestadores de salud, actualizados hasta marzo del 2016. Al ser una enfermedad de aparición nueva, las publicaciones existentes a la fecha son también muy recientes, sin estudios científicos concluyentes en cuanto al verdadero riesgo que implica la infección para la embarazada, su progenie y para la población en general.

Zika virus infection has spread in the Americas in the recent years. Venezuela has not escaped this emerging disease, and as we own a rich population of Aedes mosquitoes and also people without immunological memory to the virus makes us very susceptible to a wide distribution of the infection in a very short time, similar to what happened with other diseases spread by mosquitoes such as Dengue and Chikungunya. Pregnant women have an increased potential for infection and its transmission to their offspring due to their physiological changes in the immune system, and the vertical transmission of the virus poses a risk to the fetus, who has a higher chance to be affected mainly in the CNS, as recent publications claim. In this paper we summarize the problem, diagnosis data according to Venezuela and we resume guidelines to physicians in different fields, updated until March 2016. As Zika infection is a new emerging disease, published papers are few and non-conclusive about the true risk it implies to the pregnant women, her offspring and for the general population.

Análisis de los fenotipos y genotipos de resistencia a eritromicina y clindamicina en cepas de Streptococcus pyogenes aisladas en Chile en un período de 10 años / Resistance phenotypes and genotypes of Streptococcus pyogenes clinical isolates in Chile over a 10-year period

Background: Macrolide and lincosamide resistance in Streptococcus pyogenes is due to the acquisition of mef, ermB and ermA genes, which confer different resistance phenotypes, namely M, MLSBconstitutive and MLSBinducible respectively. The last report of resistance in Chile was done in the period 1990-1998, in which resistance to macrolides was 5.4 percent, with M phenotype as the predominant one. Aim: To characterize the evolution of erythromycin and clindamycin resistance and their associated genes in S. pyogenes strains isolated from patients with invasive and non-invasive infections in the period 1996 to 2005. Material and Methods: Resistance to erythromycin and clindamycin was determined in 1,282 clinical isolates using the disk diffusion test. Resistant isolates were analyzed by polymerase chain reaction (PCR) for the presence of the above mentioned resistance genes. Results: Global resistance to erythromycin and clindamycin was 3.5 and 0.7 percent respectively. Eighty percent of the resistant strains possessed the M. phenotype. Conclusions: Resistance levels of S. pyogenes have decreased in Chile in the last years. Most resistant strains have M phenotype in contrast to many countries in which the MLSB constitutive phenotype is the predominant one.

Arteritis de la temporal con VHS y PCR normales / Temporal arteritis with normal VHS and PCR

Se presenta un caso de arteritis de células gigantes con escasos criterios clínicos, VHS y PCR normal con neuropatía óptica isquémica posterior. Se hace una pequeña revisión del tema discutiéndose la importancia de la sospecha diagnóstica a pesar de los criterios clínicos y de laboratorios clásicamente descritos, destacando la importancia de la biopsia para el diagnóstico definitivo para el comienzo de la terapia específica, pilar fundamental para el pronóstico ocular y sistémico.

A case of giant cell arteritis with low clinical criteria, VHS and normal PCR with posterior ischemic optic neuropathy. A small review of the topic discussed the importance of the suspected diagnosis despite the clinical and laboratory criteria traditionally described, highlighting the importance of biopsy for definitive diagnosis for the commencement of specific therapy, a fundamental pillar for the ocular prognosis and systemic.

Robustez de cinco estadísticos univariados para analizar diseños Split-Plot en condiciones adversas / Robustness of five univariate statistics in analyzing Split-Plot desings under adverse conditions

En esta investigación examinamos el comportamiento de cinco estadísticos univariados para analizar datos en un diseño Split-Plot. Cuatro de ellos asumen que la matriz de desviación subyacente es no esférica. Sin embargo, existe una clara distinción entre dos alternativas, dos procedimientos presuponen que la correlación entre los datos no sigue un patrón determinado y otros dos asumen que existe autocorrelación serial de primer orden. Todos ellos fueron comparados con respecto a su robustez para poner a prueba las fuentes de variación intra-sujeto (tratamiento e interacción) bajo distribución no normal en ausencia de esfericidad y en ambas situaciones, bajo correlación serial de primer orden y bajo correlación arbitraria. Los resultados muestran que cuando la distribución es no normal simétrica todos los procedimientos muestran una tasa de error de Tipo I similar a la obtenida bajo distribución normal. Conforme el grado de sesgo y curtosis incrementa, todos los procedimientos experimentan una alteración en su estimación de la tasa de error de Tipo I y que depende de la estructura de la matriz de covarianza que subyace a los datos. En el conjunto de condiciones sometidas a estudio los procedimientos más robustos fueron HCH, JN y LEC.

In this research we examine the behaviour of five univariate statistics for analyzing the data of a Split-Plot design. Four of them assume that the dispersion matrix underlying is not spherical. However, they do so with a clear distinction between two alternatives, insofar as two of them presuppose that the correlation between the data does not have a certain structure and other two assume that there exists first-order serial autocorrelation. All of them were compared with regard to their robustness to test the sources of variation within-subject (treatment and interaction) under non-normality in the absence of sphericity, both when there was first-order serial autocorrelation and when the underlying correlation was arbitrary. The results show that when the distribution is non-normal symmetric all the procedures show a Type I error rate similar to the obtained one under normal distribution. As the degree of skewness and kurtosis increases, all the procedures experience an alteration in their estimation of the Type I error rate and that it depends on the structure of covariance matrix underlying in the data. In the set of conditions submitted to study the most robust procedures were HCH, JN and LEC.

Procedimientos estadísticos alternativos para evaluar la robustez mediante diseños de medidas repetidas / Alternative satatistical procedures to assess the robustness using repeated measures designs

The purpose of this investigation was assessing the robustness of a series of new procedures under the traditional ANOVA approach to analyze some data corresponding to repeated measures by means of Monte Carlo simulation. In order to study the efficacy of these procedures for the control of Type I rate of errors, four variables were handled: sample size; structure of dispersion matrixes; relationship between the group sizes and the dispersion matrices, and population distribution pattern. Results suggest that the Improved General Approach, Proc Mixed program with the Kenward-Roger solution, Brown-Forsythe and Welch James procedures offer a very good behavior to control the Type I rate of errors both for the main effect of the measurement opportunities as well as the effect of interaction, under all the assessed conditions.

El propósito de la presente investigación radica en evaluar la robustez de una serie de nuevos procedimientos alternativos al tradicional enfoque ANOVA para analizar datos de medidas repetidas mediante el método de simulación Monte Carlo. Para estudiar la eficacia de estos procedimientos en el control de las tasas de error de Tipo I se manipularon cuatro variables: tamaño de la muestra, estructura de las matrices de dispersión, relación entre el tamaño de los grupos y el de las matrices de dispersión y forma de distribución de la población. Los resultados obtenidos sugieren que los procedimientos Aproximación General Mejorada, Proc Mixed con la solución Kenward-Roger, Brown-Forsythe y Welch James ofrecen un muy buen comportamiento para controlar las tasas de error de Tipo I, tanto para el efecto principal de las ocasiones de medida como para el efecto de la interacción, bajo todas las condiciones evaluadas.

Diferencias individuales en dietantes crónicos: Influencia de los sistemas motivacionales en la alimentación / Differences among chronic restrained eaters: the influence of motivational systems

Background: Restrained eaters (RE) are individuals who restrain their food intake on a regular basis as they are frightened to gain weight. However, they tend to overeat under conditions of anxiety. It has been shown that RE possess a behavioral inhibition system that is more active in tonic terms, which would partially explain their affective vulnerability. Even so, the influence of variations in the activation levels of the emotional systems on the eating behavior of a RE is still unknown. Our hypothesis is that variations of such systems will give place to two types of RE: a successful or a non-successful one. Aim: To assess the influence of variations on the activation of motivational systems in food intake of RE. Materials and methods: As part of a factorial experimental design, 105 undergraduate university students were part of an experimental test for inducting food intake. Then they reported their levels of dietary restraint and their emotional behavioral preferences. Results: Differences in the activation of motivational systems were significantly related to differences in food intake (F= 7.210; p= 0.001). Additionally, food intake for those RE with a predominant inhibition system tended to be higher than for those with a more active approach system, though the latter did not reach a significant difference (F=0.718; p=0.399). Conclusions: Although more investigations are required, our data suggest that the success of retaining the diet among the RE would depend on their profile of affective reactivity (affective style). There are putative implications for research on anorexia and obesity.

Simulación en trabajadores que solicitan pensión por invalidez laboral / Malingering among workers seeking disability insurance

Objetivo: Describir la frecuencia y características de los trabajadores afiliados a la Seguridad Social con trastornos de simulación que solicitan pensión por invalidez. Material y métodos: Encuesta comparativa realizada en 136 trabajadores atendidos durante 2001, en quienes se identificaron tres grupos: trabajadores simuladores (TS), trabajadores sin invalidez (TSI), y trabajadores con invalidez (TCI). Para identificar las diferencias entre grupos, se aplicó la prueba z para variables escalares, y prueba de χ2 para variables nominales. Resultados: La incidencia de simuladores fue de 2.2/100,000 trabajadores. La edad media de los trabajadores fue: 41.9 ± 10.1 años, 440 fue el promedio de días de incapacidad laboral; 51(37%) trabajadores presentaron simulación. 35(26%) trabajadores fueron invalidados para el trabajo y 50(37%) sin invalidez. Los trabajadores simuladores tienen mayor nivel de escolaridad que TSI y TCI (p < 0.02); laboran mayoritariamente en la seguridad social (p < 0.05), con menor número de empleos previos (p < 0.05), presentan incapacidad laboral de mayor duración, (p<0.05), los síntomas depresivos son infrecuentes (p < 0.025) con electroencefalograma y tomografía normales. Conclusiones: Los trabajadores simuladores que demandan pensión por invalidez para el trabajo presentan características particulares diferentes a otros trabajadores que solicitan un estado de invalidez.

OBJECTIVE: Describe the frequency and characteristics of Mexican Social Security workers with malingering disorder that request disability pension. MATERIAL AND METHODS: Comparative survey made among 136 workers seen during 2001, which were divided into three groups: malingering workers (MW), workers without disability (WOD), and workers with disability (WWD). We administered the Z Test for scaled variables and Z2 Test for nominal variables to identify group differences RESULTS: The incidence ofmalingering was of 2.2/100,000 workers. Mean age was 41.9 +/- 10.1 years, 440 was the average number of days of labor disability; 51 (37%) workers were malingerers. 35 (26%) workers were work disabled and 50 (37%) without disability. Malingerers had higher level of schooling compared with WOD and WWD (p < 0.02); most worked at the Social Security (p < 0.05), with lower number of previous jobs (p < 0.05), presented longer work disability (p < 0.05). Depressive symptoms were not frequently noted (p < 0.025) and all had normal electroencephalogram and brain computed tomography studies. CONCLUSIONS: Malingering workers who request work disability pensions follow a particular pattern that differs from other workers that request disability assessment at the Social Security Institute of Mexico.

Evaluación del efecto de una intervención cognitivo-conductual sobre los niveles de presión arterial en adultos mayores hipertensos bajo tratamiento médico / Effects of a cognitive-behavioral intervention on blood pressure of hypertensive elderly subjects

Background: Cognitive and behavior therapy can be used as an adjunct to medications to reduce blood pressure in hypertensive patients. Aim: To design a brief psychological intervention for hypertensive patients and assess its effects on blood pressure. Material and methods: Thirty eight hypertensive subjects (35 women, age range 63-77 years) were studied. They were randomly divided in a control and experimental group. The latter group attended eight sessions of a cognitive-behavioral intervention, lasting two hours each, during one month. In each session, subjects were trained in relaxation techniques, cognitive modeling and psycho education. The main outcome assessed was a change in blood pressure levels. Results: In the experimental group, there was a significant reduction from baseline to the second post test assessment, in systolic and diastolic blood pressure levels from 134±9 to 123±8 mmHg and from 87±5 to 73±6 mmHg, respectively. Conclusions: The psychological intervention used in the present study achieved significant reductions in blood pressure levels in this group of hypertensive subjects.

Factores de riesgo asociados a los accidentes de trabajo en la industria de la construcción del Valle de México / Risk Factors Associated with Work-Related Accidents in the Construction Industry in the Valley of Mexico

Objetivo: describir la prevalencia de accidentabilidad en la industria de la construcción, factores asociados e impacto potencial en trabajadores afiliados al Instituto Mexicano del Seguro Social (IMSS) en el Valle de México. Material y métodos: casos y controles retrospectivo de casos prevalentes. Casos: 385 trabajadores de la industria de la construcción que sufrieron y les fue dictaminado accidente de trabajo en el año de 2001. Controles: 385 trabajadores activos de la industria de la construcción sin antecedente de accidente de trabajo, pareados por sexo, puesto de trabajo, y centro de trabajo. En uno y otro grupos se exploraron características demográficas y laborales que incluyó la capacitación en el trabajo. Resultados: la prevalencia de accidentabilidad en trabajadores de la construcción: 5.5%; factores de riesgo más importantes y fracción etio lógica (FeE): grupo de edad de 16 a 20 años, OR =1.58 [IC 95%: 1.40-10.7], (p=0.001), FeE:0.36, aseguramiento eventual, OR= 3.7[IC95%: 2.16-26.45], (p= 0.001), FeE: 0.72, y falta de capacitación para el trabajo, OR=5.3[IC95%: 4.9-69.2], (p= 0.01), FeE: 0.81. Variables que no mostraron significancia fueron: salario, antigüedad en el puesto, turno y jornada de trabajo. En su conjunto, la capacitación laboral estuvo ausente en 87% de todos los trabajadores sujetos a estudio. Conclusiones: la prevalencia de accidentabilidad mantiene preponderancia en la industria de la construcción del Valle de México; los factores de riesgo identificados son potencialmente modificables donde la capacitación laboral adquiere indiscutible relevancia.

Objective: Our aim was to describe construction-industry work-related accident prevalence in, associated factors in, and potential impact on affiliated workers of the Mexican Institute of Social Security (Instituto Mexicano del Seguro Social, IMSS) in the Valley of Mexico. Materials and Methods: Prevalent cases in a retrospective case-control design. Cases: These include 385 construction-industry workers who were found to have construction work-related accidents in 2001. Controls: comprised 385 active construction-industry workers without work-related accident background paired by gender, workplace, and worksite. Results. Work-related accident prevalence in construction workers was 5.5%; most important risk factors and etiology fraction (Ef) included the following: age 16-20 years odds ratio, OR = 1.58, 95% confidence interval (95% CI) 1.40-10.7, p=0.001, Efi 0.36; eventual insurance, OR = 3.7, 95% CI, 2.16-26.45, p = 0.001), Efi 0.72, and no training for job, OR =5.3, 95% CI, 4.9-69.2, p = 0.01), Ef: 0.81. Variables not showing significance were included salary, work shift, and workday. Conclusions. Work-related accident prevalence maintains its preponderance in the Valley of Mexico construction industry; identified risk factorsare potentially modifiable, among which job training acquires unquestionable relevance.

El subregistro potencial de accidentes de trabajo en el Instituto Mexicano del Seguro Social / Potential under-registration of occupational accidents in the Mexican Institute of Social Security

OBJETIVO: Evaluar el potencial subregistro de casos de accidentes de trabajo atendidos en el Instituto Mexicano del Seguro Social. MATERIAL Y MÉTODOS: Estudio transversal llevado a cabo en México con información a escala nacional proveniente de 27 Delegaciones del Instituto Mexicano del Seguro Social (IMSS) sobre trabajadores atendidos por probable accidente de trabajo, según declaración del trabajador en su primera atención en los servicios de urgencia de hospitales del IMSS durante el mes de noviembre de 2001, que posteriormente se comparó con los registros de casos reclamados o reconocidos oficialmente como accidentes de trabajo, lo que permitió identificar la proporción de los mismos que no terminaron el proceso de calificación. El análisis de la información se hizo a través de estadística descriptiva para cada variable; la estimación anual de las proporciones encontradas se realizó mediante la multiplicación por 12 meses y los intervalos de confianza se estimaron en 95% con el método exacto de Poisson para una proporción. RESULTADOS: La información de 27 de 37 Delegaciones del IMSS reveló que 7 211 casos no fueron reconocidos como accidentes de trabajo en el periodo de estudio; lo que equivaldría a un subregistro de accidentes de trabajo nacional de 26.3%, con variaciones en las Delegaciones de 0 a 68%. Los diagnósticos más frecuentes fueron contusiones y heridas leves. CONCLUSIONES: El subregistro encontrado puede afectar las prestaciones a trabajadores y el equilibrio financiero del seguro de riesgos de trabajo. Sin embargo, todavía es necesario investigar sus causas y los factores para abatirlo, debiendo participar empresarios, instituciones de trabajo y de salud.

Intervenciones psicológicas basadas en la evidencia para la prevención de la delincuencia juvenil: un programa de habilidades sociales en ambientes educativos / Psychological interventions based on juvenile delinquency prevention evidence: a social skills program in educational settings

Seis menores en conflicto con la justicia recibieron un programa de habilidades sociales para ampliar repertorios conductuales socialmente deseables y con ello facilitar su ajuste social y personal a diferentes ambientes. El diseño utilizado para evaluar la implementación de un tratamiento eficaz es el de línea base múltiple. El análisis realizado se hace en términos de significación clínica y estadística. Los resultados permiten concluir que los cambios observados se deben al tratamiento clínico implementado y que las políticas sociales para abordar el problema debieran considerarse para su aplicación en el largo plazo. Estas precauciones se han tomado por el hecho de ser un estudio de series temporales cortas y con ello evitar conclusiones apresuradas a partir de los efectos del ôtrauma ocularõ (Kazdin, 1984).

Effect of the quality of health care on permanent inability secondary to femoral fractures due to occupational accidents

Objective. To construct and validate an indicator for evaluating the quality of care for femoral fractures, and to assess the contribution of the quality of health care as a determinant of partial permanent inability secondary to femoral fractures due to occupational accidents. Materials and methods. The study was conducted from January to December 1995 at Mexican Institute of Social Security. The instrument was designed with experts' contribution along different stages and validated using implicit criteria and factorial analysis. A case-control study was then conducted to evaluate the contribution of the quality of care to inability secondary to femoral fractures. Cases were 108 active workers with permanent inability secondary to femoral fracture; controls were 94 active workers with fractu-re of femur but no permanent inability. Logistic regression modeling was used to establish the association between quality of care and partial permanent inability, adjusting by relevant variables. Results. The ultimate indicator of quality of care consisted of the following: Timely care, pre-surgical management, surgical management, and fracture complications. A final score over 229 points meant that the worker had received good quality of care. Workers getting 229 or less points had received poor quality of care. Forty-eight (44 por ciento) cases and 66 (70 por ciento) controls received good quality of medical care. The likelihood of partial permanent inability was almost three times higher among workers given poor quality of care (OR 2.95; 95 por ciento CI 1.5 - 5.5). According to the multivariate model, predictors of partial permanent inability were: Having exposed or epiphysiary fractures, being re-submitted to surgery, having less than 90 days of rehabilitation care, and receiving deficient medical care. Conclusions. The constructed instrument was validated. The level of the quality of care received by workers is a determining factor for the generation of partial permanent inability. In workers having femoral fractures, it is important to consider timely medical care and early rehabilitation, to reduce the high incidence and prevalence of this medical problem in Mexico. The English version of this paper is available too at: http://www.insp.mx/salud/index.html