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BACKGROUND: Tellurium is a rare metalloid that exerts high toxicity on cells, especially on bacteria, partly due to reactive oxygen species (ROS) generation. Moreover, it has also been observed that tellurite can target free cell thiols groups (RSH) (i.e. reduced glutathione (GSH)), enhancing the cellular redox imbalance. Additionally, in vitro experiments have suggested that several enzymes can reduce tellurite (IV) to its elemental form (0); where RSH present on their active sites may be responsible for the process. Nevertheless, the mechanisms implemented by bacteria for tellurite reduction and its role in resistance have not been evaluated in vivo. RESULTS: This work shows that tellurite reduction to elemental tellurium is increased under anaerobic conditions in E. coli cells. The in vivo tellurite reduction is related to the intracellular concentration of total RSH, in the presence and absence of oxygen. This metabolization of tellurite directly contributes to the resistance of the bacteria to the oxyanion. CONCLUSIONS: We demonstrated that in vivo tellurite reduction is related to the intracellular thiol concentration, i.e. large availability of cellular RSH groups, results in a more significant reduction of tellurite. Furthermore, we observed that, when the bacterium exhibits less resistance to the oxyanion, a decreased tellurite reduction was seen, affecting the growth fitness. Together, these results let us propose that tellurite reduction and the intracellular RSH content are related to the oxyanion bacterial resistance, this tripartite mechanism in an oxygen-independent anaerobic process.

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BACKGROUND: Tellurium is a rare metalloid that exerts high toxicity on cells, especially on bacteria, partly due to reactive oxygen species (ROS) generation. Moreover, it has also been observed that tellurite can target free cell thiols groups (RSH) (i.e. reduced glutathione (GSH)), enhancing the cellular redox imbalance. Additionally, in vitro experiments have suggested that several enzymes can reduce tellurite (IV) to its elemental form (0); where RSH present on their active sites may be responsible for the process. Nevertheless, the mechanisms implemented by bacteria for tellurite reduction and its role in resistance have not been evaluated in vivo. RESULTS: This work shows that tellurite reduction to elemental tellurium is increased under anaerobic conditions in E. coli cells. The in vivo tellurite reduction is related to the intracellular concentration of total RSH, in the presence and absence of oxygen. This metabolization of tellurite directly contributes to the resistance of the bacteria to the oxyanion. CONCLUSIONS: We demonstrated that in vivo tellurite reduction is related to the intracellular thiol concentration, i.e. large availability of cellular RSH groups, results in a more significant reduction of tellurite. Furthermore, we observed that, when the bacterium exhibits less resistance to the oxyanion, a decreased tellurite reduction was seen, affecting the growth fitness. Together, these results let us propose that tellurite reduction and the intracellular RSH content are related to the oxyanion bacterial resistance, this tripartite mechanism in an oxygen independent anaerobic process.

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Exposure to the tellurium oxyanion tellurite (TeO3(2-)) results in the establishment of an oxidative stress status in most microorganisms. Usually, bacteria growing in the presence of the toxicant turn black because of the reduction of tellurite (Te(4+)) to the less-toxic elemental tellurium (Te(0)). In vitro, at least part of tellurite reduction occurs enzymatically in a nicotinamide dinucleotide-dependent reaction. In this work, we show that TeO3(2-) reduction by crude extracts of Escherichia coli overexpressing the zwf gene (encoding glucose-6-phosphate dehydrogenase) takes place preferentially in the presence of NADPH instead of NADH. The enzyme responsible for toxicant reduction was identified as 6-phosphogluconate dehydrogenase (Gnd). The gnd gene showed a subtle induction at short times after toxicant exposure while strains lacking gnd were more susceptible to the toxicant. These results suggest that both NADPH-generating enzymes from the pentose phosphate shunt may be involved in tellurite detoxification and resistance in E. coli.

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OBJECTIVE: To establish an abdominal surgical infection prognostic index with all risk factors. SUMMARY BACKGROUND DATA: Individuals, requiring abdominal surgery have an established surgical infection risk of 1% and this risk increases with several factors, such as age over 50 years, (4%), diabetes mellitus (12%), obesity (8%), hospitalization up to 10 days (4%), bad nutrition (2%), surgical time up to 3 h (6%) summer (4%) shock (6%) immunosuppression (6%), contaminated surgery (from 1%-40%), or emergency surgery (4%). METHOD: We reviewed 199 patients and investigated previous disease, total white blood cells, oxygen saturation, albumin, body weight, type of surgery performed in regard to contamination, surgical time, hospitalization time, preoperative hair removal previous to surgery, presence of emergency surgery, and prevalence of remote site infections at time of surgery. All these parameters were reviewed for 48 h before and after the surgical procedure and every risk factor acquired a number with respect to the established risk in the world literature. An index called Prognostic index of surgical infections (PISI) was performed, made up of the addition of risk factors. Every patient was observed 10 days after the surgical procedure searching for abdominal or wound infection and correlating the index with the presence of surgical infection. RESULTS: Patients with a prognostic index of 12 or less did not show infections in any case; those with an index of 13 to 15 points had 30% of risk infection, 16 to 18 obtained 70%, 19 to 21 acquired 90%, and 22 or more obtained 100% of surgical risk infection. Sensitivity was 100% and specificity, nearby 75%. CONCLUSIONS: PISI is a reliable indicator of surgical infection risk because it takes into account all factors that cause troubles in the patients, and has high sensitivity and very good specificity.

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BACKGROUND: Since it's description in 1923, Hartmann's procedure is widely used for the surgical treatment of acute left colonic complications when preoperative bowel lavage is not feasible and/or there is high risk of anastomotic dehiscence. OBJECTIVE: Analyze the results of Hartmann's operation in the surgical treatment of consecutive patients at a single institution during a 30-month interval. TYPE OF STUDY: Prospective, non-randomized and longitudinal study. MATERIAL AND METHODS: Patients treated with the Hartmann procedure between March 1995 and September 1998. Surgical indication, intraoperative findings, morbidity and mortality were analyzed as well as the rate of reestablishment of bowel continuity and it's morbimortality. RESULTS: Ninety-two patients underwent a Hartmann procedure. The mean patient's age was 60 +/- 25 years (range of 21 to 88 years) and 60% were older than 65 years. An emergency operation was carried out in 91% of the cases. Most of the patients had intra-abdominal sepsis (56%) and benign colonic process (83%). The morbidity rate was 34% and mortality rate 19. During follow-up the bowel continuity was reestablished in 32% of the cases without fatalities. CONCLUSIONS: Hartmann's procedure is a good option for non-elective surgical treatment complicated rectosigmoid pathology. The morbidity and mortality of the operation are highly dependent on the degree of preoperative sepsis and the patient's preexisting condition. The rate of reestablishment of bowel continuity was low probably because of short follow-up.

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BACKGROUND: The reinstitution of oral intake in patients who have undergone intraabdominal surgery has traditionally progressed in a stepwise fashion beginning with clear liquids, liquid diet and after an adequate tolerance regular diet. OBJECTIVE: To determine if the reinstitution of oral intake after major abdominal surgery with regular diet offers benefits into which it's not harmful for patients and reduce the in-hospital stay. TYPE OF STUDY: Prospective, randomized, open study conducted between October 1996 to May 1997. MATERIAL AND METHODS: Patients aged 18 and older submitted to elective or urgent surgery of the abdomen and pelvis were included with the exception of: bariatric surgery, esophageal resection, pyloroplasty, pancreato-duodenal resection, laparoscopic surgery and patients under ventilatory support or with enteral or parenteral nutrition. As soon as postoperative ileus disappeared patients were randomly assigned to receive regular diet (group 1) or clear liquids (group 2) as the first oral intake. Oral diet tolerance was evaluated as well as the caloric and protein intake, the in-hospital stay and the cost. RESULTS AND MEASUREMENTS: Group 1 was conformed by 63 patients, and group 2 for 69 patients. There was no difference between, sex, age, kind of surgery (elective or emergency) and the type of pathology. 96.6% of patients in group 1 tolerated regular diet and 96.9% of patients in group 2 tolerated clear liquids. Only two patients of each group required oral intake suspension. The in-hospital stay was 2.6 +/- 2.0 days in group 1 against 3.4 +/- 2.6 in group 2 (P = < 0.005), the cost of the in-hospital stay period after the beginning of oral intake was 2726 +/- 2107 pesos in group 1 against 3547 +/- 2690 in group 2 (P = < 0.005), the caloric and protein intake were 1307 +/- 523 Kcals with 55.9 +/- 23.2 grams of proteins in group 1 and 651 +/- 204 Kcals and 0 grams of proteins in group 2 (P = < 0.00001). CONCLUSIONS: No difference was found in adverse reactions with the use of regular diet as the first meal. The in-hospital stay and the cost were reduced significantly and the calories and grams of proteins are higher in group 1. These results suggest that the routine use of clear liquids as the initial postoperative diet may be unnecessary and nutritionally suboptimal when compared with regular diet.

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La endometriosis apendicular tiene una frecuencia menor de 1 por ciento de las endometriosis pelvicas. Su diagnostico en la mayor parte de las ocasiones es incidental. Se informa un caso de endometriosis apendicular en una mujer en la cuarta decada de la vida, con antecedentes de esterilidad primaria, que ingreso con cuadro doloroso abdominal en cuadrante inferior derecho sin otros datos clinicos, radiologicos e do laboratorio que sugirieran el diagnostico. Se intervino con diagnostico preoperatorio de apendicitis aguda y se el realizo apendicectomia. El estudio histopatologico demostro focos endometrioides en la serosa apendicular sin datos de apendicitis aguda. La endometriosis debe considerarse entre las posibilidades diagnosticas en mujeres con cuadros "apendiculares" en los dias premenstruales y menstruales

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