Co-cultures of colon cancer cells and cancer-associated fibroblasts recapitulate the aggressive features of mesenchymal-like colon cancer.

Background: Poor prognosis in colon cancer is associated with a high content of cancer-associated fibroblasts (CAFs) and an immunosuppressive tumor microenvironment. The relationship between these two features is incompletely understood. Here, we aimed to generate a model system for studying the interaction between cancer cells and CAFs and their effect on immune-related cytokines and T cell proliferation. Methods: CAFs were isolated from colon cancer liver metastases and were immortalized to prolong lifespan and improve robustness and reproducibility. Established medium and matrix compositions that support the growth of patient-derived organoids were adapted to also support CAF growth. Changes in growth pattern and cellular re-organization were assessed by confocal microscopy, live cell imaging, and immunofluorescence. Single cell RNA sequencing was used to study CAF/organoid co-culture-induced phenotypic changes in both cell types. Conditioned media were used to quantify the production of immunosuppressive factors and to assess their effect on T cell proliferation. Results: We developed a co-culture system in which colon cancer organoids and CAFs spontaneously organize into superstructures with a high capacity to contract and stiffen the extracellular matrix (ECM). CAF-produced collagen IV provided a basement membrane supporting cancer cell organization into glandular structures, reminiscent of human cancer histology. Single cell RNA sequencing analysis showed that CAFs induced a partial epithelial-to-mesenchymal-transition in a subpopulation of cancer cells, similar to what is observed in the mesenchymal-like consensus molecular subtype 4 (CMS4) colon cancer. CAFs in co-culture were characterized by high expression of ECM components, ECM-remodeling enzymes, glycolysis, hypoxia, and genes involved in immunosuppression. An expression signature derived from CAFs in co-culture identified a subpopulation of glycolytic myofibroblasts specifically residing in CMS1 and CMS4 colon cancer. Medium conditioned by co-cultures contained high levels of the immunosuppressive factors TGFß1, VEGFA and lactate, and potently inhibited T cell proliferation. Conclusion: Co-cultures of organoids and immortalized CAFs recapitulate the histological, biophysical, and immunosuppressive features of aggressive mesenchymal-like human CRC. The model can be used to study the mechanisms of immunosuppression and to test therapeutic strategies targeting the cross-talk between CAFs and cancer cells. It can be further modified to represent distinct colon cancer subtypes and (organ-specific) microenvironments.

Acutely altered mental status as the main clinical presentation of multiple strokes in critically ill patients with COVID-19.

BACKGROUND AND AIMS: Cerebral infarction in COVID-19 patients might be associated with a hypercoagulable state related to a systemic inflammatory response. Its diagnosis might be challenging. We present two critically ill patients with COVID-19 who presented acutely altered mental status as the main manifestation of multiple strokes. METHODS: Clinical presentation and diagnostic work-up of the patients. RESULTS: Two patients in their sixties were hospitalized with a bilateral pneumonia COVID-19. They developed respiratory failure and were admitted to ICU for mechanical ventilation and intense medical treatment. They were started on low-molecular-weight heparin since admission. Their laboratory results showed lymphopenia and increased levels of C-reactive protein and D-dimer. Case 1 developed hypofibrinogenemia and presented several cutaneous lesions with biopsy features of thrombotic vasculopathy. Case 2 was performed a CT pulmonary angiogram at ICU showing a bilateral pulmonary embolism. When waking up, both patients were conscious but with a remarkable global altered mental status without focal neurological deficits. A brain MRI revealed multiple acute bilateral ischemic lesions with areas of hemorrhagic transformation in both patients (case 1: affecting the left frontal and temporal lobes and both occipital lobes; case 2: affecting both frontal and left occipital lobes). Cardioembolic source and acquired antiphospholipid syndrome were ruled out. COVID-19-associated coagulopathy was suspected as the possible main etiology of the strokes. CONCLUSION: Acutely altered mental status might be the main manifestation of multiple brain infarctions in critically ill COVID-19 patients. It should be specially considered in those with suspected COVID-19-associated coagulopathy. Full-dose anticoagulation and clinical-radiological monitoring might reduce their neurological consequences.

Sex is a strong prognostic factor in stage IV non-small-cell lung cancer patients and should be considered in survival rate estimation.

BACKGROUND: Biological differences between the sexes have a major impact on disease and treatment outcome. In this paper, we evaluate the prognostic value of sex in stage IV non-small-cell lung cancer (NSCLC) in the context of routine clinical data, and compare this information with other external datasets. METHODS: Clinical data from stage IV NSCLC patients from Hospital Puerta de Hierro (HPH) were retrieved from electronic health records using big data analytics (N = 397). In addition, data from the Spanish Lung Cancer Group (GECP) Tumor Registry (N = 1382) and from a published study available from the cBioPortal (MSK) (N = 601) were analyzed. Survival curves were estimated using the Kaplan-Meier method. A Cox proportional hazards regression model was used to assess the prognostic value of sex. A meta-analysis to compare the outcome for males and females in terms of overall survival (OS) and progression free survival (PFS) was performed. RESULTS: The median OS time was 12 months for males and 19 months for females (overall HR = 0.77; 95% CI: 0.68-0.87; P < 0.001). Similarly, females with stage IV NSCLC harboring an EGFR-sensitizing mutation lived significantly longer than males (median OS: males, 19 months; females, 32 months) with a lower risk of death compared with males (overall HR = 0.75; 95% CI: 0.67-0.84). In addition, female patients benefited more from EGFR inhibitors in terms of PFS and OS (overall HR = 0.45; 95% CI: 0.32-0.64, and HR = 0.62; 95% CI: 0.48-0.80, respectively). Median PFS was 21 months in females and 12 months in males (P < 0.001). CONCLUSIONS: Using routine clinical data we confirmed the previous finding that among stage IV NSCLC patients, females had a significantly better prognosis than males. The effect size of the sex was notable, highlighting the fact that survival rates are usually estimated and patients are generally managed without considering the sexes separately, which may lead to suboptimal results.

Terapia Electroconvulsiva y Estimulación Magnética Transcraneal Repetitiva en pacientes con esquizofrenia: una revisión sistemática / Electroconvulsive Therapy and Repetitive Transcranial Magnetic Stimulation in patients with schizophrenia: a systematic review

Cuando la esquizofrenia no responde satisfactoriamente a tratamiento farmacológico, alcanzar una terapia efectiva para el paciente es una tarea bastante frustrante para el médico psiquiatra. Es en este contexto que la terapia electroconvulsiva y la estimulación magnética transcraneal repetitiva han tomado fuerza en la investigación clínica, a pesar de los grandes cuestionamientos sobre su efectividad y mala reputación. Se realizó una revisión sistemática de la literatura en las principales bases de datos disponibles. Concluyendo que ambas terapias demuestran ser herramientas útiles en el tratamiento de la esquizofrenia resistente a tratamiento farmacológico, así como también complementarias a los antipsicóticos

When schizophrenia does not respond satisfactorily to pharmacological treatment, achieving effective therapy for the patient is quite a frustrating task for the psychiatrist. It is in this context that electroconvulsive therapy and repetitive transcranial magnetic stimulation have gained strength in clinical research, despite huge questions about its success and bad reputation. A systematic review of the literature was conducted in the main available databases. Concluding that both specific therapies will be useful tools in the treatment of schizophrenia resistant to pharmacological treatment, as well as complementary to antipsychotics.

Deterioro cognitivo y factores de riesgo cardiovascular y metabólico en una muestra de adultos de Bogotá / Cardiovascular and metabolic risk factors, for cognitive impairment in adults from Bogotá

Introducción: la relación entre los factores de riesgo cardiovascular (FRCV) y los factores metabólicos con deterioro cognitivo (DC), definido como deterioro cognitivo leve (DCL) o demencia, es controversial. Objetivo: describir los FRCV y metabólicos relacionados con DC, en una muestra de adultos de Bogotá. Material y métodos: se diseñó un estudio de corte transversal y se evaluó el estado cognitivo en dos fases, en adultos mayores de 50 años, autónomos, no institucionalizados, aplicando pruebas neuropsicológicas y un protocolo de evaluación neuropsiquiátrica. Los FRCV y metabólicos fueron documentados por autoreporte, y se tomaron medidas antropométricas. Resultados: en 1.045 adultos estudiados, el promedio de edad fue de 68 años (DS 8.6), y de educación 8 años (DS 6.0), 76 % fueron mujeres, 56 % presentaba hipertensión arterial (HTA), 40 % dislipidemia, 37 % fueron fumadores, 37 % tenían sobrepeso, 28 % hipotiroidismo, 25 % obesidad, 17 % consumían alcohol y 16 % eran diabéticos. El DCL se asoció con escolaridad de primaria-incompleta OR:1.94 (95 % IC: 1.21- 3.14), primaria-completa OR:1.96 (95 % IC: 1.18- 3.25), bachillerato- incompleto OR:3.01 (95 % IC: 1.80-5.05), bachillerato-completo OR: 2.54 (95 % IC: 1.45- 4.45) y con edad entre 70 y 79 años OR:2.06 (95% IC: 1.32-3.23). La demencia se asoció con escolaridades de primaria-incompleta OR: 11.20 (95 % IC: 4.99- 25.12), primaria-completa OR: 7.91 (95 % IC: 3.44-18.16), bachillerato- incompleto OR: 2.87 (95 % IC: 1.17- 7.01) y con edades entre 70 -79 años OR: 2.82. (95 % IC: 1.37-5.80), o mayores de 80 años OR: 7.68 (95 % IC: 3.49- 16.90) y con sufrir HTA OR: 1.45 (95 % IC: 1.03-2.05). Conclusión: la baja escolaridad, una edad avanzada y sufrir HTA son en su orden los factores más importantes para el desarrollo de la demencia. Los adultos entre 70 y 79 años con bachillerato incompleto, tienen mayor riesgo de DCL.

Introduction: The relationship between some metabolic and cardiovascular risk factors (CVRF) and cognitive impairment (CI) defined as mild cognitive impairment (MCI) and dementia, is controversial. Objective: Describe the cardiovascular and metabolic risk factors that are associated with cognitive impairment in adults from Bogotá. Materials and methods: A cross-sectional study, where the state of cognitive functions (normal, MCI or dementia) was evaluated in two phases, in adults older than 50 years, autonomous, non-institutionalized, using neuropsychological tests and neuropsychiatric protocol. Its cardiovascular and metabolic risk by self-reported history and standardized anthropometric measurements were documented. Results: Of 1045 adults surveyed, the mean age of the group was 68 years(SD 8.6), and the mean education level was 8 years(SD 6.0), 76% were women, 56% had hypertension(HT), 40% dyslipidemia, 37% were smokers, 36% were overweight, 28% presented hypothyroidism, 25% were obese, 17% drank alcohol and 16% were diabetic. MCI was associated with incomplete high school education OR:3.01(95% CI 1.80-5.05) and aged between 70 and 79 years OR:2.06(95%CI 1.32-3.23). Dementia was associated with lower scholarity, incomplete-primary OR:11.20(95%CI 4.99-25.12), complete-primary OR 7.91(95% CI.3.44-18.16), incomplete-high school OR: 2.87(95% CI 1.17-7.01), age over 80 years OR:7.68(95%CI 3.49-16.90); and suffer hypertension OR:1.45(95%CI 1.03- 2.05) Conclusion: Low education, older age and hypertension are in order, the most important risk factors for the development of dementia in our population. Adults between 70 and 79 with incomplete high school have higher risk of MCI.

Sobrevivencia del recién nacido menor de 1500gr y factores que lo afectan en el Servicio de Neonatología de Hospital Nacional Arzobispo Loayza del 2010 al 2012 / Survival of newborn under 1500gr and factors affecting it in the Neonatology Service of National Hospital Arzobispo Loayza from 2010 to 2012

Objetivo: Conocer algunas características epidemiológicas y clínicas relacionadas a la supervivencia de los niños menores de 1500gr al nacer, entre el 1ro de enero del 2010 al 31 de diciembre del 2012, en el Servicio de Neonatología del Hospital Nacional Arzobispo Loayza. Método: Es un estudio Observacional, transversal, analítico de 186 recién nacidos menor a 1500gr, que fueron seguidos hasta el alta hospitalaria o al fallecimiento. Resultados: Los promedios de peso al nacer, edad gestacional y tiempo de seguimiento fueron, 1078gr, 29,6 semanas y 29,96 días respectivamente. La incidencia de depresión cardiorespiratoria severa fue 31.2 por ciento, Enterecolitis necrotizante del 12.4 por ciento, Hemorragia Intraventricular (HIV) 25,7 por ciento y sepsis tardía en 40.9 por ciento. Conclusiones: La incidencia de sobrevivencia fue del 43 por ciento. El peso al nacer fue un factor protector frente al riesgo de fallecer, mientras que el Síndrome Distrés Respiratorio, Enterocolitis Necrotizante, Hemorragia Intraventricular y asfixia fueron determinantes en la mortalidad.

Torsión del apéndice cecal asociada a invaginación intestinal / Torsion of the vermiform appendix associated with intussusception

La torsión del apéndice vermiforme es muy rara; en la literatura sólo han sido referidos 25 casos. El aquí informado es el primero asociado a invaginación intestinal. Se trató de una niña de dos meses de edad quien súbitamente dio muestras de dolor. En la exploración quirúrgica se encontró invaginación ileocecal apretada, que fue corregida. Cuatro días después fue necesario reoperar, encontrando torsión y perforación del apéndice cecal; se practicó apendicectomía. Por datos de obstrucción y peritonitis se requirió nueva exploración quirúrgica en la que se encontró dehiscencia del muñón y perforación cecal. Una vez corregidas estas complicaciones, la paciente evolucionó satisfactoriamente y fue dada de alta en buenas condiciones.

BACKGROUND: Vermiform appendix torsion is a rare condition, with only 25 cases recorded in the international literature. Our patient is the first case associated with intussusception. CASE REPORT: A 2-month-old female infant suddenly developed severe abdominal pain due to ileoceal intussusception. During surgical exploration, a tight intussusception was reduced. Three days later, a new laparotomy was required and we found torsion and perforation of the vermiform appendix. The patient underwent appendectomy, but there was dehiscence of the appendiceal stump and cecal perforation requiring a new surgical exploration. The patient had an uneventful recovery.

Colangiografía oral y la atresia duodenal / Oral cholangiography and duodenal atresia

Se presenta el caso de un recién nacido masculino con síndrome de Down, que presentó al nacimiento vómito biliar y al examen físico ictericia y hepatomegalia leve. Los estudios radiológicos simple de abdomen y la serie gastrointestinal mostraron al duodeno dilatado y cambios inflamatorios de la mucosa. Esta imagen es conocida como la imagen en “doble burbuja” y es común en la obstrucción duodenal congénita. Simultáneamente fueron visualizados la vesícula biliar y el colédoco, siendo este hallazgo poco usual. Se le efectuó corrección del defecto mediante el procedimiento de Kimura.

A newborn male patient with trisomy-21 presented with bilious hemesis. The patient was icteric with slight hepatomegaly. Simple abdominal X-ray and upper gastrointestinal series with barium showed a dilated duodenal loop and inflammatory changes involving the duodenal mucosa. This image known as [quot ]double bubble[quot ] is characteristic of congenital duodenal obstruction. Simultaneously the gallbladder and choledochus were visualized. The former X-ray finding is very unusual. An uneventful Kimura procedure was performed.

[Torsion of the vermiform appendix associated with intussusception]. / Torsión del apéndice cecal asociada a invaginación intestinal.

BACKGROUND: Vermiform appendix torsion is a rare condition, with only 25 cases recorded in the international literature. Our patient is the first case associated with intussusception. CASE REPORT: A 2-month-old female infant suddenly developed severe abdominal pain due to ileoceal intussusception. During surgical exploration, a tight intussusception was reduced. Three days later, a new laparotomy was required and we found torsion and perforation of the vermiform appendix. The patient underwent appendectomy, but there was dehiscence of the appendiceal stump and cecal perforation requiring a new surgical exploration. The patient had an uneventful recovery.

Effect of a long-term fire retardant (Fire Trol 934) on the germination of nine Mediterranean-type shrub species.

Fire Trol 934 is a long-term fire retardant commonly used in fire prevention and extinction. Our objective was to determine the effect of this chemical on seed germination of nine plant species from Mediterranean-type shrublands, where these chemicals are potentially used. Seeds were exposed to five different Fire Trol concentrations, (0 (control) to 10%, on a log scale) and monitored in a germination chamber for nine weeks. Seeds from four Cistus species were subjected to an additional heat treatment that simulated thermal scarification caused by fire. Retardant exposure caused a significant decrease in total germination in all species, and exposure to the highest Fire Trol concentration (10%) resulted in complete inhibition of germination. However, the sensitivity to Fire Trol varied across species and this differential species sensitivity may potentially lead to different impacts in the soil seed banks depending on whether sites are burned or unburned. Exposure to Fire Trol 934 may affect recruitment of shrubland species particularly during dry autumns, due to limited leaching of these chemicals from the soil surface. Consequently, its use should be avoided in sites where particularly sensitive plant species are present.

Effects of thoracic epidural meperidine on arterial oxygenation during one-lung ventilation in thoracic surgery.

OBJECTIVE: To compare the effects that the use of general intravenous anesthesia (propofol-fentanyl) (GA) or general anesthesia combined with thoracic epidural anesthesia with meperidine (TEA-M) may have on arterial oxygenation during one-lung ventilation (OLV). DESIGN: Prospective. SETTING: Tertiary care hospital. PARTICIPANTS: Seventy-two patients undergoing OLV for thoracic surgery. INTERVENTIONS: Patients were prospectively randomized into two groups: GA (n = 37) fentanyl, propofol, rocuronium anesthesia was used; and group TEA-M (n = 35) were anesthetized with propofol, rocuronium and thoracic epidural meperidine (2 mg/kg in 10-12 mL) administered before anesthetic induction. A double-lumen endotracheal tube was inserted, and mechanical ventilation with 100% oxygen was used during study. Mean arterial pressure, heart rate and arterial and venous blood gases were recorded with the patients in the lateral decubitus position in three phases: during two-lung ventilation (TLV), 15 and 30 minutes after beginning OLV (OLV + 15 and OLV + 30 respectively). The authors measured arterial and venous central oxygen tension, arterial and venous central oxygen saturation, arterial and venous central oxygen content and venous admixture percentage (Qs/Qt%). MEASUREMENTS AND MAIN RESULTS: There were no statistical differences between the two groups for PaO(2) during OLV + 15 (GA = 165 mmHg, TEA-M = 153 mmHg) and OLV + 30 (GA = 176 mmHg, TEA-M = 158 mmHg); and with values for Qs/Qt%. CONCLUSIONS: It is concluded that GA combined with TEA-M (2 mg/kg) do not affect arterial oxygenation during OLV in thoracic surgery.

Grado de conocimiento sobre SIDA en la Clínica Rural Juancho, Pedernales, período junio-julio 1998 / Level of knowledge about aids at the \"Juancho\" rural clinic, Pedernales, período June-July 1998

Con el propósito de conocer el grado de conocimiento que poseen en la comunidad Juancho, Pedernales; sobre SIDA, se realizó durante el período junio-julio 1998, un estudio descriptivo, prospectivo y analítico; se encuestó a 112 personas tomadas al azar y mayor de 15 años. El 79 (70.5//) era femenino, 72 (64.3//) conviven en unión libre, el 26 (23.2//) era analfabeto, 73 (65.2//) cree cierto la existencia del SIDA, un 22 (19.6//) no sabe si tiene tratamiento. En cuanto a fuentes de conocimiento expresaron en un 55 (49.1//) a la gente y un 43 (38.4//) en la radio. El 86 (36.1//) considera como vía principal de transmisión las relaciones sexuales y el 19 (7.9//) no sabe, el 49 (40.8//) consideró la fidelidad como la principal medida preventiva. Enflaquecimiento 47 (20.6//), diarrea 62 (27.2//), vómito 30 (13.1//) fueron los principales signos y síntomas de presentación, el 29 (12.7//) no sabe. Se considera pues que las personas encuestadas poseen un amplio porcentaje de conocimiento sobre SIDA en algunos aspectos

Incidencia de ictericia en recién nacidos del Hospital Luis Manuel Morillo King de La Vega, marzo-diciembre 1994 / Incidence of newborn icterus at the \"Luis Morillo King\" Hospital of La Vega, March-December 1994

El recién nacido ictérico, representa hoy por hoy un reto para nuestros Gineco-obstetras, médicos generales y de manera muy particular para nuestros perinatólogos. El objetivo del presente estudio fue conocer el grado de incidencia que ocupa la ictericia del recién nacido en la población perteneciente al Hospital Luis Manuel Morillo King; La Vega, República Dominicana durante el período marzo-diciembre 1994. Durante el período de nuestra investigación fueron asistidas en nuestro centro un total de 2518 recién nacidos niños de los cuales 74 casos (2.9) presentaron ictericia. (79.7//) resultaron ser a término; 15 de ellos recién nacidos prematuros. (2.7//) de las madres habían sido sometidas a transfusión sanguínea por lo menos en una ocasión. Se ha demostrado que la oxitocina usada de manera prolongada como inductor y/o conductor de la labor de parto se ha relacionado con la ictericia. En nuestro estudio se utilizó oxitocina en 8 de las madres cuyos recién nacidos presentaron ictericia 10.8// del total

Incidencia de factores asociados a prematuridad: Hospital Dr. Luis Manuel Morillo King, La Vega. - Marzo - Diciembre 1994 / Incidence of factors associated with prematurity \"Luis Manuel Morillo King\" Hospital, La Vega, March-December, 1994

Se realizó un estudio prospectivo de corte transversal durante el período marzo-diciembre de 1994 en el Hospital Dr. Luis Manuel Morillo King en pacientes asistidas por el departamento de obstetricia con fines de determinar factores asociados a prematuridad y su incidencia. De un total de 2,518 nacidos vivos, 92 de ellos correspondieron a prematuros con una incidencia de 3.7// y una mortalidad de 1.08//. El 1.50// de los prematuros -estuvieron comprendidos entre los 32-34 semamas de edad gestacional; encontramos que a menor peso de los prematuros, mayor fue su mortalidad. Los factores asociados a pre-maturidad más frecuentemente encontrado fueron sangrado del tercer trimestre en un 1.11//, antecedentes de prematuridad 0.74// y 0.55// a embarazos múltiples

Tratamientos odontológicos ambulatorios bajo anestesia general con ketamina / Ambulatory dental treatments under general anesthesia with ketamine

Se presenta la experiencia obtenida en 72 pacientes pediátricos que requerían tratamientos odontológicos ambulatorios, pero que por diversas razones no podían ser realizados en forma convencional utilizando anestesia local, por lo que se empleó clorhidrato de ketamina como agentes anestésico general a una dosis de 3.5 mg/kg por vía intramuscular, con lo cual la inducción y la anestesia fueron efectivas produciéndose durante el postoperatorio manifestaciones clínicas más atenuadas que las descritas en la literatura permitiendo así realizar los tratamientos planificados. El uso de ketamina después de haber realizado una evaluación preoperatoria adecuada y bajo control pertinente, administrada en dosis mínimas por vía intramuscular puede ser el anestésico general ideal para tratamientos odontológicos cortos en pacientes pediátricos ambulatorios con dificultad de manejo

Incidencia de intoxicaciones por organofosforados: enero 1988-enero 1990 / Organophosphates intoxication incidence : January 1988- January 1990

Presentamos 38 casos de intoxicación por órganofosforados. Encontramos que el sexo masculino estuvo más afectado (63 por ciento de los casos). La mayor incidencia ocurrió en el grupo de 2-4 años de edad, (34.2 por ciento de los casos). El 84 por ciento de los casos ocurrió de forma accidental

Defícit de Alfa 1 antitripsina: su relación con algunas enfermedades hepáticas y pulmonares / Alpha 1 antitriosin deficit: its relation with some hepatic and pulmonary diseases

Se trata de un trabajo descriptivo realizado en 60 pacientes ingresados en el Servicio de Medicina Interna del Hospital Clínicoquirúrgico Docente "General Calixto García" por diversas enfermedades hepáticas y pulmonares. A todos se les realizó en sangre Alfa 1 Antitripsina(A1-AT), se encontró que el 31,7% tuvieron niveles disminuidos de esta proteina. Se detectaron tres casos con niveles de Alfa 1 correspondientes con los de fenotipos ZZ y 16 con cifras relacionadas con fenotipos heterocigógitos. Predominó en general el sexo femenino y las edades entre entre 15 y 35 años. Se comparan los resultados obtenidos con otros trabajos y se sugiere incrementar los estudios al respecto debido a los beneficios terapéuticos que pueden recibir los pacientes con esta enfermedad

Prevalencia de antigenos de superficie de la hepatitis B en personal médico del hospital pediátrico Dr Robert Reid Cabral, Santo Domingo, Distrito Nacional

Realizamos un estudio en 78 médicos del Hospital Dr Robert Reid Cabral, determinándose la presencia del antígeno de superficie para la hepatitis B (HBSAG), obteniéndose los siguientes resultados: Dos casos resultaron positivos de los 78 estudiados para un 2.5% y lo consideramos un nivel bajo de positividad. Los dos casos correspondieron al grupo etario de 30 a 39 años y laboraban uno en el área de cirugía y otro en el de enfermedades contagiosas