RESUMEN
Laparoscopic cholecystectomy has changed the treatment of symptomatic gallstones. We present an initial experience with this technique. From March 1990 to March 1991, there were 250 patients who were studied. There were 182 females and 68 males, with most classified as American Society of Anesthesiology Index Class I or II. All procedures were done using electrocautery. There was a definite learning curve for the procedure as evidenced by the duration of the operation. The mean time to perform the procedure was 112 minutes for the first 50 patients and 79 minutes for the last 50 patients. We converted 12 percent of the procedures to an open cholecystectomy for a variety of reasons, the most common being inflammation and adhesions in the triangle of Calot. However, we only had a 4 percent conversion rate in the last 50 patients. There were nine serious complications, with no deaths. The most frequent was a bile leak from the cystic duct stump. Other complications included a pneumothorax, requiring chest tube drainage and an unobserved carcinoma of the stomach. There were no injuries to the common bile duct. The results of our current experience confirm the safety and efficacy of laparoscopic cholecystectomy for the treatment of symptomatic gallstones. The use of electrocautery is safe during laparoscopy and the need for a laser is optional. Laparoscopic cholecystectomy will continue to evolve as more experience is gained and new instruments are introduced.
Asunto(s)
Colecistectomía/métodos , Colelitiasis/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Laparoscopía , Masculino , Persona de Mediana EdadRESUMEN
The widely scattered cardiovascular chromaffin cells of Petromyzon marinus appear to form an intrinsic control system of circulatory function. In response to blood-borne stimuli, a checkpoint-like accumulation of epinephrine cells in the heart releases its hormone; epinephrine, in turn, stimulates the release of norepinephrine, and probably also of dopamine, from other cardiovascular chromaffin cells. The myocardium seems to be a major target of norepinephrine. On the other hand, high disappearance rates of epinephrine and dopamine in the gills point to these organs as possible major targets of the latter two secretions. Carbon dioxide and hypovolemia are strong stimuli of catecholamine release.
Asunto(s)
Catecolaminas/sangre , Peces/sangre , Lampreas/sangre , Animales , Glucemia/metabolismo , Volumen Sanguíneo , Dióxido de Carbono/sangre , Fenómenos Fisiológicos Cardiovasculares , Sistema Cromafín/fisiología , Lampreas/fisiología , Oxígeno/sangreRESUMEN
Radioimmunoassays revealed the presence of the following steroids (or immunoreactive steroid fractions) in the plasma of larval sea lampreys: progesterone, corticosterone, cortisol, androstenedione, testosterone, dihydrotestosterone, estrone, and estradiol. Several types of stress served to provoke the release of these substances. A statistically significant effect of the treatment was noted under only one condition: squeezing of the body of decapitated ammocoetes during blood collection caused an increase in plasma dihydrotestosterone and a decrease in plasma estradiol. The discovery of all eight steroids (or immunoreactivities) assayed for suggests that the plasma of the ammocoete may contain a considerable number of additional steroids yet to be identified.