Risk factors associated with surgical infections are related to many events that modulate the immune system and affect the surgical procedure. The aim of this study was to determine the influence of low CD4+ lymphocyte counts in 24 patients with human immunodeficiency virus (HIV) undergoing abdominal surgery. Blood samples were obtained, and the lymphocyte population was evaluated perioperatively, as was the nutritional status of the patient. All the patients received selective antibiotic prophylaxis depending on the surgical procedure performed: (1) clean surgery: splenectomies (n = 8); (2) clean-contaminated: cholecystectomy and biliary tract surgery (n = 8); and (3) contaminated: appendectomy (n = 8). Depending on their CD4 count, two groups were formed: one with 200 to 500 cells/ml (n = 11) and the other with < 200 cells/ml (n = 13). When surgical infection was suspected, surgical drainage and microbiologic cultures were undertaken. For statistical evaluation of the groups ANOVA and the chi-square test were used; p < 0.05 was considered significant. Altogether 14 patients (58.3%) had a wound infection, and the mean (+/- SD) CD4 count in those patients was decreased (221.7 +/- 75.1) compared with that of the 10 patients in the uneventful group (386 +/- 81.2). Surgical infection rates were 50% for clean procedures, 62.5% for clean-contaminated procedures, and 62.5% for contaminated surgery. The group of patients with CD4 counts of < 200 cell/ml had an increased incidence of surgical infection, regardless of the type of surgery (p = 0.002). Thus the surgical infection rates with HIV patients undergoing abdominal surgery are dramatically increased. The CD4 and subsequently depressed neutrophil populations increase the risk of surgical infection during major procedures regardless of the type of surgery performed.

Objective: all-trans-retinoic acid (ATRA) promotes cell differentiation. We have studied its effect on the local recurrence and metastatic spreading of an experimental rhabdomyosarcoma in rats.Design: syngenic rhabdomyosarcoma cells (S4MH) were inoculated s.c. in male WAG/RijCrl rats. After 25 days tumors were excised and a 40% hepatectomy was performed for all animals. Ten days later the rats were sacrificed and a thorough necropsy was performed. The animals were randomly allocated to receive daily doses of ATRA (5 mg/kg, i.p.) or its solvent (Clinoleic ® /ethanol 90/10), starting three days before surgery until the end of the experiment.Results: ATRA reduced the incidence of local recurrence from 70 to 33% (p < 0.05), but the tumor size was not altered (1.8 vs. 2.0 cc). Regarding inguinal metastasis, there was a sixfold decrease (0.2 vs. 1.2 cc; p < 0.05) in mean tumor volume, although the rate of this proliferation increased sharply (86 vs. 29%; p < 0.05) for treated animals. The volume of the retroperitoneal tumor masses also decreased with ATRA (0.7 vs. 5.1 cc; p < 0.05), but the difference in rate was not significant (71 vs. 67%). Lung metastases, which were present in 100% of control animals, were found in only 33% of treated rats, while the mean number of metastatic foci dropped from 26.7 to 5.7 (p < 0.05).Conclusion: protocols including retinoid administration prior to and following primary tumor excision could help in controlling both recurrence and metastatic progression in surgically treated rhabdomyosarcoma.Key words: Rat. Rhabdomyosarcoma. Recurrence. Metastasis. All-trans-retinoic acid. García-Alonso I, Palomares T, Alonso INTRODUCTIONOver the past decade, remarkable progress has been made in antineoplastic therapy, with surgery still in the forefront as the main curative approach. However, recurrence of disease following tumor resection remains a major problem, not only because of failed local control but also because of the effect of surgery on the distant proliferation of disease, thus reducing patient quality of life and survival (1).While tumor recurrence depends to a great extent on the radicality of surgery, it can also be induced by biological responses initiated following tissue aggression as implied by the operation itself. Indeed, in an experimental carcinogenesis model, researchers observed that the rate of colon tumor development following a carcinogen was much higher within healing anastomoses in the colon (2).Surgery, it must be remembered, triggers local release of multiple growth factors (GF) that are responsible for wound healing, but which may also act as paracrine factors giving tumor cells the signal they require to divide and proliferate (3). Such factors include beta fibroblast proliferation-stimulating GF (FGFb), platelet-derived growth factor (PDGF), hepatocyte growth factor (HGF), and others (4-6). It is important therefore to design combined treatments that will inhibit residual tumor cell proliferation following surgery, without impairment of the healing process.Today ...

Liver regeneration plays a key role in restoring the liver/body ratio after partial liver transplantation. However, hepatic ischemia hinders the proliferative response of the hepatocytes. In this study, different ways of improving the regenerating capacity of ischemic hepatocytes are tested. Following 70% hepatectomy and 15 min of normothermic liver ischemia, the percentage of regenerating hepatocytes and the regenerative gradient are assessed. Cyclosporine A (hepatotrophic agent), superoxide dismutase and folinic acid (antioxidants), administered during the ischemic period, have significantly increased these indices. The later drug has restored the regenerative response to the levels of normoperfused livers.

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