Hallazgos en tomografía computada multidetector en el diagnóstico del carcinoma hepatocelular en pacientes con cirrosis y su correlación con la anatomía patológica del explante hepático / Findings in multidetector computed tomography in the diagnosis of hepatocellular carcinoma in patients with cirrhosis and correlation with pathology of liver explants

Objetivos: Describir el comportamiento imagenológico del hepatocarcinoma en pacientes con cirrosis utilizando la tomografía computada multidetector (TCMD) dinámica y correlacionar los hallazgos con el grado histológico de los tumores. Materiales y métodos: Estudio retrospectivo, observacional y descriptivo, donde se evaluaron 51 nódulos de 32 pacientes trasplantados de hígado con diagnóstico de cirrosis. La anatomía patológica del explante fue utilizada como referencia y los nódulos con histología de hepatocarcinoma fueron analizados retrospectivamente en las tomografías computadas efectuadas antes del trasplante. Las tomografías se llevaron a cabo con técnica dinámica, evaluando las características más frecuentes reportadas en la literatura: realce arterial, lavado del realce, cápsula y vasos arteriales intratumorales. Resultados: Cuarenta y seis de 51 (90%) tumores mostraron realce arterial. De estos 46 tumores, 39 (85%) mostraron lavado del realce en la fase portal y/o tardía. De los 51, 5 (10%) fueron hipovasculares, 22 (43%) presentaron cápsula y 12 (24%) mostraron vasos arteriales intratumorales. La combinación de hallazgos más frecuente fue la asociación de realce arterial y lavado del realce en la fase portal-tardía (39/51 tumores: 76%), y el grado histológico más usual fue el II en 35 tumores (69%). Se hallaron asociaciones estadísticamente significativas entre el grado histológico de los tumores y los comportamientos imagenológicos realce arterial e hipovascular. Conclusión: En nuestra población, el hallazgo tomográfico de realce arterial con lavado del realce en tiempo portal y/o tardío fue observado en la mayoría de los tumores. Esto coincide con publicaciones anteriores y contribuye a fortalecer el valor de estos criterios para el diagnóstico del hepatocarcinoma...

Objectives: To describe the imagenological behavior of hepatocellular carcinoma in cirrhotic patients using a dynamic multidetector computed tomography (MDCT) technique, and correlate these fi ndings with histological tumor grades.Materials and methods: A retrospective, descriptive observational study was conducted to evaluate 51 nodules in 32 liver transplant patients diagnosed with liver cirrhosis. The pathology of liver explants was used as a reference. Nodules with hepatocellular carcinoma histopathology were retrospectively analyzed by computed tomography scans performed pre-transplant. Using a dynamic multidetector computed tomography technique, we evaluated the mos common imagenological behavior reported in the literature: arterial enhancement, washout, capsule, and intratumoral arterial vessels.Results: Forty-six of 51 (90%) tumors showed arterial enhancement. Of the 46 tumors with arterial enhancement, 39 (85%) had washout in portal-late phase. Five of 51 (10%) were hypovascular. Twenty-two of 51 (43%) had capsule and 12 of 51 (24%) showed intratumoral arterial vessels. The more frequent image combination was the combination of arterial enhancement and washout (39 of 51 tumors or 76%). The most frequent histological grade was II (35 of 51 tumors or 69%). Statistically signifi cant relationships were found between histological grade tumors and imagenological behavior: arterial enhancement and hypovascular. Conclusion: In our population, arterial enhancement with washout in portal-late phases was observed in most of the tumors. Our results are consistent with previously reported studies, demonstrating the high reliability of this imaging pattern for the diagnosis of hepatocellular carcinoma...

Effects of mercury intoxication on the response of horizontal cells of the retina of thraira fish (Hoplias malabaricus)

Methyl mercury (MeHg) is highly neurotoxic, affecting visual function in addition to other central nervous system functions. The effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish Hoplias malabaricus. Intracellular responses were recorded from horizontal cells of fish previously intoxicated with MeHg by intraperitoneal injection (IP group) or by trophic exposure (T group). Only one retina per fish was used. The doses of MeHg chloride administered to the IP group were 0.01, 0.05, 0.1, 1.0, 2.0, and 6.0 mg/kg. The amplitudes of the horizontal cell responses were lower than control in individuals exposed to 0.01 (N = 4 retinas), 0.05 (N = 2 retinas) and 0.1 mg/kg (N = 1 retina), whereas no responses were recorded in the 1.0, 2.0, and 6.0 mg/kg groups. T group individuals were fed young specimens of Astyanax sp previously injected with MeHg corresponding to 0.75 (N = 1 retina), 0.075 (N = 8 retinas) or 0.0075 (N = 4 retinas) mg/kg fish body weight. After 14 doses, one every 5 days, the amplitude of the horizontal cell response was higher than control in individuals exposed to 0.075 and 0.0075 mg/kg, and lower in individuals exposed to 0.75 mg/kg. We conclude that intoxication with MeHg affects the electrophysiological response of the horizontal cells in the retina, either reducing or increasing its amplitude compared to control, and that these effects are related to the dose and/or to the mode of administration.

Actividad inhibitoria y bactericida de ciprofloxacina, temafloxacina y tosufloxacina sobre Staphylococcus spp. Aislados en hospitales de ciudades chilenas / Inhibitory and bactericidal activity of ciprofloxacin, temafloxacin and tosufloxacin against staphylococcus isolated from chilean hospitals

Inhibitory and bactericidal activities of ciprofoxacin, temafloxacin and tosufloxacin were determined against isolates of Staphylococcus aureus and coagulase negative Staphylococci from various chilean hospitals. Time-kill experiments were performed against one selected strain of each of these bacterial isolates. Tosufloxacin showed highest activity against isolates of Staphylococci either methicillin resistant and methicillin susceptible. Ciprofloxacin was slightly less active temafloxacin