[Results of the participation of resident physicians in the surgical treatment of gallbladder lithiasis]. / Resultados de la participación de médicos residentes en el tratamiento quirúrgico de la litiasis vesicular.

The aim of this retrospective study was to evaluate the impact of resident participation in the results of surgical treatment in 1149 consecutive patients operated for biliary disease between January, 1980 and December, 1987 at the Instituto Nacional de la Nutrición "Salvador Zubirán". Patients were divided in three groups: GROUP I. 640 cases treated by surgical residents under a senior surgeon supervision. GROUP II. 168 patients operated by the chief surgical resident. GROUP III. 341 patients treated by senior staff surgeons. Age, sex and risk factors were similar between groups. Residents performed more operative cholangiograms (p less than 0.05). In general, senior surgeons performed more transduodenal sphincteroplasties (p less than 0.05) and other additional procedures like appendectomies and gastrostomies during the same surgery. Wound infection was more frequent in group III patients (p less than 0.005) but there was no significant clinical difference in other postoperative complications like intraabdominal abscess, bile fistula, wound dehiscence, intraabdominal bleeding, iatrogenic injury of the biliary tract, and residual common duct stone. The duration of the in-hospital convalescence period was similar in all three groups. The mortality rate for the total series was 2.2%. In group II there were more patients affected for acute cholecystitis, and more patients died postoperatively (p = less than 0.01). We may consider this difference attributable to the more complex patients handled by the chief resident. Mortality rate among patients with chronic biliary tract disease was less than 1%. We were not able to demonstrate any significant difference in mortality and complication rates between those patients operated by residents, chief residents and senior surgeons.(ABSTRACT TRUNCATED AT 250 WORDS)

Testosterone biotransformation by the isolated perfused canine pancreas.

There is strong evidence indicating that the pancreas is under the influence of sex steroid hormones, and that it may even participate in their biosynthesis and metabolism. In the present study, [3H]testosterone was perfused into the isolated canine pancreas, and measured in the effluent with several of its metabolites (5 alpha-dihydrotestosterone, androstenedione, and estradiol). Results show that testosterone is readily transformed by the canine pancreas. The main product found in the effluent is androstenedione. The testis and spleen were also perfused with [3H]testosterone and used as controls. In both cases, this hormone appeared mostly unchanged in the effluent as compared to the pancreatic perfusion (p less than 0.0001). From our data, we conclude that the canine pancreas has the capacity to transform sex steroid hormones, and could be considered an extragonadal site of sex steroid biosynthesis.

[Splenectomy in idiopathic thrombocytopenic purpura]. / Esplenectomía en púrpura trombocitopénica idiopática.

Between January 1976 and December 1987, 44 patients with idiopathic thrombocytopenic purpura were submitted to splenectomy. This study analyzes the results of treatment and the usefulness of several prognostic markers. There were 38 female patients and six males with a median age of 28.5 years (range 11 to 66 years). Forty two out of 44 patients received preoperative steroids. Seventy five percent achieved a satisfactory response to this treatment but 31 relapsed (in eight recurrence was observed when the steroid dose was tapered). Eleven patients persisted symptomatic notwithstanding medical treatment. In two cases splenectomy was performed as an emergency procedure, and in one patient who was already in remission with previous steroid treatment, splenectomy was performed for other medical reasons. Operative mortality rate was 4 percent, and five patients developed postoperative complications (three had pneumonia, one pulmonary thromboembolism and one would infection). Eighty four percent of the patients were free of disease at one year followup survival at 10 year period was 80 percent. No correlation was found between age, duration of symptoms, previous response to steroids or time-period of medical treatment with the results obtained with splenectomy.

[Immunoreactive urinary thromboxane B2 in experimental mesenteric thrombosis in dogs]. / Tromboxano B2 urinario inmunorreactivo en trombosis mesentérica experimental en perros.

Thromboxane B2 (TxB2) the stable metabolite of thromboxane A2 may be released as a response to ischemia. With the aim of investigating its role as an early diagnostic test in mesenteric thrombosis, immunoreactive TxB2 was measured in urine aliquotes in six sham operated dogs, nine dogs subjected to superior mesenteric artery ligation, and twelve dogs with superior mesenteric vein ligation. One hour urine volumes were collected before surgery and during the eight hours after the experimental procedures, and urinary osmolarities were also determined in each sample. Basal TxB2 levels were comparable in all groups. Although all groups showed a significant and rapid (one hour) increase in TxB2 as a response to surgery, in the controls it returned to normal after six hours, whereas in the rest a continuously increased production persisted throughout the study period. There was no difference in t-test comparisons depending on the sort of thrombosis. In spite of the urinary dilution induced during the study, a persistent increase in TxB2 excretion was found. We conclude that urinary TxB2 levels could prove useful in the early diagnosis of mesenteric ischemia.

Urinary thromboxane B2 as an indicator of acute rejection in lung allotransplantation.

The behavior of urinary thromboxane B2 (TXB2) during acute rejection of lung allotransplants was evaluated. Unmatched mongrel dogs were submitted to a left lung orthotopic allotransplantation (groups I and II), or a sham operation (group III). All animals had an initial significant elevation of TXB2 excretion due to surgical trauma; however, in sham-operated animals (group III) this elevation returned to basal levels after 3 days. All transplanted animals (groups I and II) had persistent TXB2 elevation with 2 important peaks on postop days 5 and 9. The elevated TXB2 excretion persisted in spite of immunosuppressive treatment with azathioprine and prednisone (group II). Rejection was followed by means of an objective grading system applied to chest roentgenograms taken on all animals. It was found that TXB2 levels correlated directly with the grade of radiographic changes seen, thus indicating degree of rejection. TXB2 can be useful as a noninvasive indicator for surveillance of lung allograft rejection.