RESUMEN

Es difícil generar con bombas convencionales las condiciones de flujo del sistema cardiovascular, con las cuales se emulen condiciones hemodinámicas para evaluar diferentes dispositivos interpuestos a la corriente sanguínea. Para resolver este inconveniente, se desarrolló un sistema automatizado de bombeo de flujo pulsátil, conformado por un controlador difuso que captura datos de los instrumentos de monitoreo de variables hidrodinámicas a través de una interfaz de adquisición, y aplica señales de control a una bomba de flujo pulsátil. Este sistema permite hacer pruebas hidromecánicas que brindan elementos para interpretar la influencia de las variables que intervienen en el flujo pulsante y simular condiciones hemodinámicas en un ambiente de circulación extracorpórea. Mediante técnicas de diseño asistido por computador, se construyó una bomba de diafragma accionada neumáticamente. El controlador se desarrolló mediante la técnica de Fuzzi Control (marca registrada), el cual regula el pulso y el flujo de acuerdo con parámetros y datos capturados con...

With conventional pumps, it is difficult to generate the cardiovascular system conditions that may emulate hemodynamic conditions for evaluating different devices interposed to the blood flow. In order to resolve this inconvenient, an automated pulsatile flow system formed by a diffuse controller that captures data from the monitoring instruments of hydrodynamic variables through an acquisition interface and applies control signals to a pulsatile flow pump, was developed. This system allows making hydromechanical tests that give elements for interpreting the influence of the variables that take part in the pulsatile flow and emulate hemodynamic conditions in an extracorporeal setting. Through computed assisted design techniques, a pneumatically operated diaphragmatic pump was constructed. The controller was developed by the Fuzzi Control® technique, which regulates pulse and flow according to the data captured by the acquisition interface. The prototype tests were realized in a fluids laboratory by varying frequency, hydraulic resistance, viscosity and pulse pressure, emulating hemodynamic adult conditions, and using as work fluid an aqueous solution with 5 cPo at 37°C for mimicking blood viscosity at corporal temperature. The reproduction of a pump that serves for analyzing the effect of variables in the pulsatile flow may be used in the study of different intravascular devices and help to refine technical and functional aspects in the preliminary study of extracorporeal circulation machines.

Asunto(s)

RESUMEN

INTRODUCTION: Myotonic dystrophy type 1 is a neuromuscular, degenerative and progressive disease, with an autosomal dominant pattern of inheritance, variable expressivity and incomplete penetrance. The genetic defect is an unstable mutation due to the expansion of the triplet CTG in the 3 unstranslated region at the DMPK gene on chromosome 19q13.3. OBJECTIVE: The main objective was to study the intergenerational behavior of the DM1 mutation in order to evaluate the importance of this disease as a neurological problem that could be manageable by genetic counseling. PATIENTS AND METHODS: The study involved 84 patients with clinical diagnosis of DM1 and their relatives, which were confirmed through molecular diagnosis using Southern blot and PCR. RESULTS: Data analysis reveals the size of the mutation presents a positive correlation with the severity of the symptoms and a negative correlation with the age of onset. Transmission of the DM1 mutation is sex and size dependent among the Costa Rican patients. There is an important increment in the size of the mutation between generations and there are no differences in mutation size respect to the transmitting sex. CONCLUSION: The worldwide intergenerational behavior of the DM1 mutation is similar in Costa Rica

Asunto(s)

RESUMEN

In Antioquia and Chocó, traditional healers attend 60% of snakebites. With the aim to produce an inventory of the plants used by the healers to treat snakebites and to document the methods of preparation, administration, the dosage, number of patients treated throughout their years of practice with treatment results, 20 healers with experience in Bothrops, Porthidium and Bothriechis envenomations were interviewed between August, 1996 and November, 1998. They belong to nine black and three indigenous rural communities located near the towns of Bojayá, Vigía del Fuerte, Unguía (Atrato river valley), Nuquí and Bahía Solano (Pacific coast). Based on field interviews, 101 species of plants were identified as used to treat snakebites. The part used of each plant varies according to the species. Sixty plants are used in the form of drinks prepared by infusion, decoction or maceration; 78 as external baths on the affected extremity; 11 for steam application and 39 for poultices; the latter is used mainly when the bite is complicated by local necrosis. In mild and moderate envenomations, they generally use a mixture of three plants, while in severe cases they mix from five to 12, a handful of each one. Treatment is generally performed for 1-3 days, when the patient reacts positively. They reported to have treated 454 patients during their years of experience, 20 of them (4.4%) died. With the guidance of the healers, 77 species of plants were collected and photographed. These plants belong to 41 families, of which Piperaceae (13 species), Araceae (six species), Asteraceae (five species) and Gesneriaceae (three species) have the highest number of species.

Asunto(s)

Asunto(s)

RESUMEN

An open comparative and multicentric trial was carried out to assess the activity of sulbactam ampicillin combination against no treatment, as a prophylactic agent of post-surgical infection in ob-gyn practice. 100 patients were included in the trial and distributed in two groups. sulbactam/ampicillin 0.5/1.0 g, i.v. was administrated during the surgery and the dose was repeated 6 h. later. No cases of post-surgical infection was detected in the group of sulbactam/ampicillin, while 4 cases were observed in the no treatment group. Sulbactam/ampicillin is an effective and well tolerated antimicrobial agent in the prophylaxis of post-surgical infections.

Asunto(s)

RESUMEN

BACKGROUND: Nosocomial bloodstream infection is an important cause of morbidity and mortality among neonates. From September 1 through December 5, 1990 (epidemic period), gram-negative bacteremia developed in 26 neonates after their admission to the neonatal intensive care unit (NICU) of Hospital General, a 1000-bed public teaching hospital in Guatemala with a 16-bed NICU. Twenty-three of the 26 patients (88%) died. METHODS: To determine risk factors for and modes of transmission of gram-negative bacteremia in the NICU, we conducted a cohort study of NICU patients who had at least one blood culture drawn at least 24 hours after admission to the NICU and performed a microbiologic investigation in the NICU. RESULTS: The rate of gram-negative bacteremia was significantly higher among patients born at Hospital General, delivered by cesarian section, and exposed to selected intravenous medications and invasive procedures in the NICU during the 3 days before the referent blood culture was obtained. During the epidemic period, the hospital's chlorinated well-water system malfunctioned; chlorine levels were undetectable and tap water samples contained elevated microbial levels, including total and fecal coliform bacteria. Serratia marcescens was identified in 81% of case-patient blood cultures (13/16) available for testing and from 57% of NICU personnel handwashings (4/7). Most S. marcescens blood isolates were serotype O3:H12 (46%) or O14:H12 (31%) and were resistant to ampicillin (100%) and gentamicin (77%), the antimicrobials used routinely in the NICU. CONCLUSIONS: We hypothesize that gram-negative bacteremia occurred after invasive procedures were performed on neonates whose skin became colonized through bathing or from hands of NICU personnel.

Asunto(s)

Asunto(s)

Asunto(s)