Scielo RSS <![CDATA[Acta Cirurgica Brasileira]]> vol. 31 num. 1 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[Ischemic preconditioning modifies mortality and inflammatory response]]> PURPOSE: To evaluate the effect of ischemic preconditioning on mortality, inflammatory mediators and oxidative stress after intestinal ischemia and reperfusion. METHODS: Male Wistar rats were allocated according to the period of ischemia with or without ischemic preconditioning which consist on clamping the superior mesenteric artery for 10 minutes followed by reperfusion for 10 minutes before the sustained ischemia period. Mortality was assessed in Phase 1 study, and the CINC-1, CINC-2 and MDA levels in the lungs were analyzed in Phase 2. RESULTS: Mortality was lower in the ischemic preconditioning group subjected to 90 minutes of ischemia compared to the group without ischemic preconditioning (I-90: 50% and IPC-90: 15%, p=0.018), and it was lower in the ischemic preconditioning group as a whole compared to the groups without ischemic preconditioning (IPC-14% and I=30%, p=0.006). Lower levels of MDA, CINC-1, and CINC-2 were observed in the animals that were subjected to ischemic preconditioning compared to the animals that were not (MDA: I-45=1.23 nmol/mg protein, and IPC-45=0.62 nmol/mg protein, p=0.0333; CINC-1: I-45=0.82 ng/mL and IPC-45=0.67 ng/mL, p=0.041; CINC-2: I-45=0.52 ng/mL and IPC-45=0.35 ng/mL, p=0.032). CONCLUSION: Ischemic preconditioning reduces mortality, inflammatory process and oxidative stress in rats subjected to intestinal ischemia and reperfusion. <![CDATA[Dexmedetomidine preconditioning inhibits the long term inflammation induced by renal ischemia/reperfusion injury in rats]]> PURPOSE: To investigate the protective effects of dexmedetomidine (Dex) against renal ischemia/reperfusion injury (IRI). METHODS: Sprague-Dawley rats were randomly divided to sham group, IRI group and Dex group. The SD rats were subjected to 45 min of ischemia followed by eight weeks of reperfusion. Prior to ischemia, rats were either treated with Dex or not. Blood samples were collected for the detection of blood urea nitrogen (BUN) and creatinine (Cr) levels. Immunohistochemistry was performed for CD3 T-cell infiltrates. Real-time PCR and western blot were detected for the expression of TNF-α, IL-1β, ICAM-1, HMGB1 and TLR4. RESULTS: Compared with sham group, renal IRI significantly increased the serum levels of BUN and Cr. The H&amp;E staining indicated that renal IRI resulted in obvious renal injury and immunohistochemistry found that there were more CD3 T-cell infiltrates in IRI group. Also, renal IRI upregulated the expression of TNF-α, IL-1β, ICAM-1, HMGB1 and TLR4. However, all these changes were alleviated by the treatment with Dex. CONCLUSIONS: Dexmedetomidine has beneficial effects on long term inflammation induced by renal ischemia/reperfusion injury. Its mechanisms may be achieved through inhibiting the HMGB1/TLR4 pathway to exert protective effects. <![CDATA[Remote limb ischemic post-conditioning attenuates ischemia-reperfusion injury in rat skin flapby limiting oxidative stress]]> PURPOSE: To investigate the effect of remote ischemic post-conditioning (RIPoC) against ischemia-reperfusion (I/R) injury on flaps of rats. METHODS: Sprague-Dawley rats were randomized into the Sham, Control, RIPoC1 and RIPoC2 groups. All the animals were submitted to a 5×4 cm superficial inferior epigastric artery flap. Eight hours of flap ischemia was induced and two protocols of limb RIPoC were applied. Tissue MDA level and SOD activity in 24-h reperfusion were assessed. Flap survival was assessed 7 days postoperatively. RESULTS: Compared to the Control group, the RIPoC1 group showed statistically decreased MDA level at 6-, 12-, and 24-h reperfusion (P = 0.01, P &lt; 0.01 and P &lt; 0.01, respectively), and statistically increased SOD activity at 12- and 24-h reperfusion (P &lt; 0.05 and P &lt; 0.01, respectively). Flap survival rate on the 7th day was significantly higher in the RIPoC1 group than the control group (47.9 ± 6.4 vs . 29.4 ± 7.1 %, P &lt; 0.01). CONCLUSION: Three cycles of 5-min Limb remote ischemic post-conditioning rather than a single cycle of 15-min limb RIPoC has protective effect on flaps against ischemia-reperfusion injury by attenuating oxidative stress. <![CDATA[Effect of folic acid in a modified experimental model of anorectal malformations adriamycin-induced in rats]]> PURPOSE: To determine the effect of a single dose of adriamycin (ADR) to induce anorectal malformations (ARMs) and determine the effect of folic acid (FA) in this model. METHODS: Ten female Wistar rats were divided randomly in two groups. Group A - ADR; Group B - FA+ADR. Dams from group B received daily, since two weeks before the pregnancy to the end of pregnancy, FA (50mg/kg) by gavage. Dams from both groups received ADR (6mk/kg) by intraperitoneal injection on gestational day (GD) 8. Their fetuses were harvested by cesarean section on GD21 and were examined looking for ARMs. The thickness of anal stratified squamous epithelium (ASSE) and intestinal epithelium (IE) were analyzed. p≤0.05*. RESULTS: 81 fetuses were harvested. The number of fetuses; number of ARMs; mean (∆%) (± SD) were determined to be, respectively: ADR - 41[29;65%(±37%)] versus FA+ADR - 40[04;16%(±36%)] (p=0.05). AMRs were significantly lower in FA+ADR group than in ADR group (p=0.05). The thickness (µm) of ASSE (± SD) and IE (± SD) were measured, respectively: ADR - [25.98(±0.74) and 19.48(±1.68)] versus FA+ADR - [24.74(±0.91) and 24.80(±0.81)] (p&lt;0.005). The thickness of IE was significantly enlarged when FA was given (p&lt;0.005). CONCLUSIONS: Single dose of adriamycin on D8 was able to induce anorectal malformations. Folic acid reduces the number and enlarged the IE of ARMs ADR-induced. <![CDATA[Lower energy and pulse stacking. A safer alternative for skin tightening using fractional CO<sub>2</sub> laser]]> PURPOSE : To evaluate the effect of different energies and stacking in skin shrinkage. METHODS : Three decreasing settings of a fractional CO2 laser were applied to the abdomen of Twenty five Wistar rats divided into three groups. Group I (n=5) was histologically evaluated for microthermal zones dimensions. Groups II and III (n=10 each) were macroscopic evaluated with freeware ImageJ for area contraction immediately and after 30 and 60 days. RESULTS : No statistical significance was found within microthermal zone histological dimensions (Group I) in all settings studied. (Ablation depth: 76.90 to 97.18µm; Coagulation depth: 186.01 to 219.84 µm). In Group II, macroscopic evaluation showed that all settings cause significant immediate skin contraction. The highest setting cause significant more intense tightening effect initially, contracting skin area from 258.65 to 179.09 mm2. The same pattern was observed in Group III. At 30 and 60 days, the lowest setting significantly sustained contraction. CONCLUSION : Lower fractional CO2 laser energies associated to pulse stacking could cause consistent and long lasting tissue contraction in rats. <![CDATA[Effect of low-intensity therapeutic ultrasound on wound healing in rats subjected to third-degree burns]]> PURPOSE: To determine the effectiveness of low-intensity therapeutic ultrasound (LITUS) on wound healing in rats with third-degree burns. METHODS: Twenty rats were divided into the Control Group that comprised four rats without third-degree burns that did not undergo LITUS, the Burned Group (BG), comprising eight rats with third-degree burns that did not undergo LITUS, and the Burned with Treatment Group (BTG), comprising eight rats with third-degree burns that were administered LITUS. LITUS began 24 h after injury and involved daily applications for 8 min at 0.1 W/cm2 for 14 days. RESULTS: The BTG lost less weight than the BG (Q=2.75; p&lt;0.05). No visible differences were apparent among the groups' lesions on day 4. By the end of treatment, wound healing was more evident in the BTG. No statistically significant differences were found between the BG and the BTG in relation to the parameters measured using the histological changes in burn wound healing scoring system. CONCLUSION: The LITUS protocol applied to the animals with third-degree burns accelerated the formation of fibrin-leukocyte crusts and significantly reduced weight loss. However, burn wound healing was not accelerated. <![CDATA[Expression of P53, HER2 and Ki67 proteins in rats subjected to bladder augmentation with stomach, colon and ileum]]> PURPOSE: To study the expression of HER2, p53 and Ki67 proteins in cystoplasties. METHODS: Sixty rats were distributed randomly into three groups of 20 animals. Bladder augmentation was held to increase with ileum (Group I), colon (Group II) and stomach (Group III). Tissue samples of neobladder was collected from each rat to its own control. The animals were sacrificed after 12 weeks. The neobladder was withdrawn for immunohistochemitry analysis of p53, HER2 and Ki67 expression. Wilcoxon and Mann-Whitney tests were used for statistical study. RESULTS: There were no significant changes in the expression of p53 and HER2 proteins. It was observed significant increase (p&lt;0.0001) in Ki67 expression in all groups, when compared with their respective controls. When the study groups were compared with each other, there was increase of cell proliferation in the largest gastrocystoplasties in respect of ileocystoplasties (p=0.004) and colocystoplasties (p=0.003). CONCLUSION: We observed significant increase of cell proliferation characterized by Ki67 protein in the digestive tract of the ileocystoplasties, the colocystoplasties and the gastrocystoplasties and this increase was significantly greater in gastrocystoplasties. <![CDATA[The biopolymer sugarcane as filling material of critical defects in rats]]> PURPOSE: To evaluate the effects of particulate (granule-shaped) SCB on bone repair relating it to its biocompatibility and bone neoformation. METHODS: Thirty Wistar rats were submitted to a one 7-mm-diameter defect and divided equally into three experimental groups, with two different postoperative times of evaluation, 90 and 120 days. Each calvaria defect was filled up with clot (control group), particulated autogenous bone or granulated SCB. Five animals of each group were assessed at 90 and 120 days after surgery. In these two periods, histological and histometric analysis were obtained. RESULTS: The clot group showed a bone resorption trend while the autogenous bone group a bone repair trend. However in the SCB group, the critical defect filled up only with fibrous connective tissue and presented none bone neoformation. CONCLUSION : The sugarcane biopolymer when used in critical size defects was a biocompatible material and proved to be a good material to fill bone cavities, keeping them as uniform areas filled with soft tissue and avoiding the tissue shrinkage. <![CDATA[Rabbit olfactory stem cells. Isolation protocol and characterization]]> PURPOSE: To describe a new technique for isolation of a mesenchymal stem cells (MSCs) population from the olfactory mucosa in rabbits. METHODS: Olfactory stem cells (OSCs) were retrieved from under the cribriform plate of the Ethmoid bone. Several assays were accomplished to characterize the cell population and attest its viability in vitro. The cells were submitted to flow cytometry with the antibodies CD34, CD45, CD73, CD79, CD90 and CD105 and also they were induced to differentiate in three lineages. Functional evaluation involved analysis of in vitro growth behavior, colony forming unit like fibroblasts (CFU-f) and cryopreservation response. Further transduction with Green Fluorescent Protein (GFP) was also performed. RESULTS: The OSCs showed mesenchymal features, as positive response to CD34, CD73 and CD90 antibodies and plasticity. Additionally, these cells have high proliferated rate, and they could be cultured through many passages and kept the ability to proliferate and differentiate after cryopreservation. The positive response to the transduction signalizes the possibility of cellular tracking in vivo. This is a desirable feature in case those cells are used for pre-clinical trials. CONCLUSION: The cells harvested were mesenchymal stem cells and the technique described is therefore efficient for rabbit olfactory stem cells isolation. <![CDATA[Comparison of the effects of magnesium and ketamine on postoperative pain and morphine consumption. A double-blind randomized controlled clinical study]]> PURPOSE: To compare the effects of magnesium sulfate and ketamine on postoperative pain and total morphine consumption in a placebo-controlled design. METHODS: One hundred and twenty women scheduled for total abdominal hysterectomy were included in this prospective, randomized, double-blind study. Postoperatively, when the Numeric Pain Rating Scale (NPRS) was four or more, IV-PCA morphine was applied to all patients. The patients were randomized into three groups: Group K ketamine, Group M magnesium, and Group C saline received as infusion. Total morphine consumption for 48h, pain scores, adverse effects, and patients' satisfaction were evaluated. RESULTS: Total morphine consumption was significantly lower in Group K (32.6±9.2 mg) than in Group M (58.9±6.5 mg) and in Group C (65.7±8.2 mg). The satisfaction level of patients in Group K was higher than the other two groups (p&lt;0.05). Pruritus and nausea were observed more frequently in Group C. CONCLUSİON: The addition of ketamine to IV-PCA morphine reduces the total consumption of morphine without psychotic effects; however, magnesium did not influence morphine consumption.