Scielo RSS <![CDATA[Acta Cirurgica Brasileira]]> vol. 30 num. 2 lang. en <![CDATA[SciELO Logo]]> <![CDATA[Hemodynamic changes with two lipid emulsions for treatment of bupivacaine toxicity in swines]]> PURPOSE: To compare the hemodynamic changes following two different lipid emulsion therapies after bupivacaine intoxication in swines. METHODS: Large White pigs were anesthetized with thiopental, tracheal intubation performed and mechanical ventilation instituted. Hemodynamic variables were recorded with invasive pressure monitoring and pulmonary artery catheterization (Swan-Ganz catheter). After a 30-minute resting period, 5 of bupivacaine by intravenous injection was administered and new hemodynamic measures were performed 1 minute later; the animals were than randomly divided into three groups and received 4 of one of the two different lipid emulsion with standard long-chaim triglyceride, or mixture of long and medium-chain triglyceride, or saline solution. Hemodynamic changes were then re-evaluated at 5, 10, 15, 20 and 30 minutes. RESULTS: Bupivacaine intoxication caused fall in arterial blood pressure, cardiac index, ventricular systolic work index mainly and no important changes in vascular resistances. Both emulsion improved arterial blood pressure mainly increasing vascular resistance since the cardiac index had no significant improvement. On the systemic circulation the hemodynamic results were similar with both lipid emulsions. CONCLUSION: Both lipid emulsions were efficient and similar options to reverse hypotension in cases of bupivacaine toxicity. <![CDATA[Low-level laser therapy modulates musculoskeletal loss in a skin burn model in rats]]> PURPOSE: To investigate the effectiveness of low-level laser therapy (LLLT) on gastrocnemius muscle morphology and Myod imunoexpression in a model of dorsal burn in rats. METHODS: Sixteen male Wistar rats were distributed into two groups: control group (CG): rats submitted to scald burn injury without treatment and laser treated group (LG): rats submitted to scald burn injury and treated with laser therapy. Fourteen days post-surgery, gastrocnemius muscle was evaluated being the specimens stained with HE and morphometric data was evaluated. MyoD expression was assessed by immunohistochemistry. RESULTS: The results showed that laser treated animals presented more organized tissue morphology compared to the non-treated animals, with a higher number of nucleus in the fibers. Also, the cross sectional area of the fibers and the MyoD immunoexpression in the laser treated groups was higher. CONCLUSION: Low-level laser therapy had positive effects on gastrocnemius muscle, improving tissue muscle morphology, increasing cross sectional area and MyoD immunoexpression. <![CDATA[Which is the best route of administration for cell therapy in experimental model of small-for size syndrome in rats?]]> PURPOSE: To evaluate which is the best route of administration for cell therapy in experimental rat model of small-for size syndrome. METHODS: A total of 40 rats underwent partial hepatectomy (70%) that induces the small-for-size syndrome and were divided into four groups of route administration: intravenous, intraperitoneal, enteral and tracheal. The small-for-size syndrome model was designed with extended partial hepatectomy (70%). The animals were divided into four groups of routes administration: intravenous (n=10) - intravenously through the dorsal vein of the penis; intraperitoneal (n=10) - intraperitoneally in the abdominal cavity; enteral (n=10) - oroenteral with the placement of a number 4 urethral probe and maintained at third duodenal portion; tracheal (n=10) - after tracheal intubation. We track the animals and monitor them for 21 days; during this follow-up we evaluated the result of cell therapy application tracking animals using ultrasound, radiography and PET-scan. Statistical analysis was performed using GraphPad Prism Software(r). Differences were considered significant with the p&lt;0.05. Data are presented as the median and variation for continuous variables. Comparisons between groups were made using analysis of the imaging test by the researchers. RESULTS: All four groups underwent partial hepatectomy of 70% liver tissue targeting the same weight of resected liver. Initially the PET-scan tests showed similarity in administered cells by different routes. However, in few days the route of intravenous administration showed to be the most appropriated to lead cells to the liver followed by enteral. The tracheal and peritoneal routes were not as much successful for this goal. CONCLUSION: The intravenous route is the best one to cell therapy in experimental rat model of small-for size-syndrome. <![CDATA[Preconditioning with mono and polyunsaturated fatty acids and low-intensity electrical stimulation. Effects on skin repair in rats]]> PURPOSE: To evaluate the effects of preconditioning with oils mixes containing ω3/ω6/ω9 associated with micro-currents on skin repair in rats. METHODS: One-hundred and eight Wistar rats randomized into G-1, G-2 and G-3 groups were treated with saline (0.9%), mix 1 (corn+soybean oils) and mix 2 (olive+canola+flaxseed oils), respectively, in a single dose (0.01ml/g) by gavage. Next, each group was subdivided into sham and stimulated subgroups. Pulsed-wave microcurrents (0.5 µA, 0.5 Hz) were applied to stimulated subgroups for 20 min. One hour later anesthetized rats were subjected to surgery. A dorsal incision (6 cm long) was carried out and closed with interrupted nylon sutures. Samples (1cm2) were harvested from the mid-portion of the incision on the 7, 14, 21 post-operative (P.O.) days. Variables were analyzed using Mann-Whitney/Dunn tests Significance level was set to 5 % (p&lt;0.05). RESULTS: Micro-currents promoted increase of exudate and reduction of epithelialization on day 7 in G1 rats. Mixes 1/2 reduced vascularization on 7/14th days P.O. Both 1/2 mixes reduced fibrosis on day 14. Preconditioning with mix 1 led to increased expression of NF-kB on the 7th day. CONCLUSION: Preconditioning with microcurrents has pro-inflammatory effects while oil mixes 1 and 2 decrease fibrosis and vascularization in the proliferative phase of cicatrization. <![CDATA[Pentoxifylline and prostaglandin E1 action on ischemia and reperfusion of small intestine tissue in rats. An immunohistochemical study]]> PURPOSE: To investigate the action of pentoxifylline (PTX) and prostaglandin E1 (PGE1) on ischemia and reperfusion of small intestine tissue in rats, using immunohistochemical analysis. METHODS: Thirty-five Wistar rats were distributed as follows: group A (n=10): subjected to intestinal ischemia and reperfusion for 60 min, with no drugs; group B (n=10): PTX given during tissue ischemia and reperfusion; group C (n=10): PGE1 given during tissue ischemia and reperfusion; group D (n=5): sham. A segment of the small intestine was excised from each euthanized animal and subjected to immunohistochemical examination. RESULTS: Mean number of cells expressing anti-FAS ligand in the crypts was highest in Group A (78.9 ± 17.3), followed by groups B (16.7 ± 2.8), C (11.3 ± 1.8), and D (2.5 ± 0.9), with very significant differences between groups (p&lt;0.0001). CONCLUSIONS: The use of pentoxifylline or prostaglandin E1 proved beneficial during tissue reperfusion. The immunohistochemical results demonstrated a decrease in apoptotic cells, while protecting other intestinal epithelium cells against death after reperfusion, allowing these cells to renew the epithelial tissue. <![CDATA[Copaiba oil effect on experimental jaw defect in Wistar rats]]> PURPOSE: To evaluate the effects of copaiba oil on jaw defects repair in Wistar rats treated with bioglass or adipose tissue. METHODS: A jaw defect was randomly created in forty-two rats and filled with bioglass or adipose tissue. The two groups (Gbio and Gcell) were subdivided in three subgroups with seven animals each according to gavage administration: control (distillated water), oil (copaiba oil) and melox (meloxicam). Euthanasia was performed after forty post-operative days. The bone formation was analyzed regarding the histological aspects. RESULTS: The osteoclasts activity was observed only in four subgroups (p=0.78). Regarding the osteoblasts presence, it was very similar between the subgroups, the difference was due to Gcell-melox (p=0.009) that presented less osteoblastic activity. The inflammatory cells were more evident in Gcell-melox subgroup, however, there was no difference in comparison with the other subgroups (p=0.52). Bone formation was observed in all subgroups, just two animals showed no bone formation even after 40 days. More than 50% of bone matrix mineralization was observed in 56% (23 animals) of the analyzed areas. The bone matrix mineralization was not different between subgroups (p=0.60). CONCLUSIONS: The subgroups that received copaiba oil showed bone repair, although not statistically significant in comparison to subgroups treated whit meloxicam or controls. Copaiba oil administered by gavage had no effect on bone repair in this experimental model. <![CDATA[Effects of immunosuppression with tacrolimus and mycophenolate mofetil on renal histology and function in single kidney rats submitted to ischemia and reperfusion]]> PURPOSE: To evaluate renal histological changes and renal function in single kidney rats submitted to renal ischemia-reperfusion and to immunosuppression with tacrolimus and mycophenolate-mofetil. METHODS: Experimental study with 80 Wistar rats distributed into control, Sham and six other groups treated with immunosuppressive drugs. Animals undergoing surgery, right nephrectomy and left renal clamping, killed on the 14th day and analyzed for renal histology, urea and creatinine. RESULTS: The group receiving tacrolimus at higher doses (T3) showed renal histological lesions indicative of early nephrotoxicity, and significant increase in urea and creatinine. The group M (mycophenolate-mofetil alone) and the group M2 (mycophenolate-mofetil combined with half the usual dose of tacrolimus) presented a slight rise in serum urea. The groups using mycophenolate-mofetil alone or combined with tacrolimus showed creatinine levels similar to that of the group T3. CONCLUSIONS: Histologically, the association of injury by ischemia-reperfusion with the use of tacrolimus or mycophenolate-mofetil alone demonstrated a higher rate of renal changes typical of early nephrotoxicity. In laboratory, the combination of injury by ischemia-reperfusion with tacrolimus at higher doses proved to be nephrotoxic. <![CDATA[Effects of blocking α<sub>v</sub>β<sub>3</sub> integrin by a recombinant RGD disintegrin on remodeling of wound healing after induction of incisional hernia in rats]]> PURPOSE: To investigate the changes induced by DisBa-01 on repair of wound healing after induced incisional hernia (IH) in rats. METHODS: Thirty two male albino rats were submitted to IH and divided into four experimental groups: G1, placebo control; G2, DisBa-01-treated; G3, anti-αvβ3 antibodies-treated and G4, anti-α2 antibodies-treated. Histological, biochemical and extracellular matrix remodeling analysis of abdominal wall were evaluated. RESULTS: After 14 days, 100% of the G2 did not present hernia, and the hernia ring was closed by a thin membrane. In contrast, all groups maintained incisional hernia. DisBa-01 also increased the number macrophages and fibroblasts and induced the formation of new vessels. Additionally, MMP-2 was strongly activated only in G2 (p&lt;0.05). Anti- αvβ3-integrin antibodies produced similar results than DisBa-01 but not anti-α2 integrin blocking antibodies. CONCLUSION: DisBa-01 has an important role in the control of wound healing and the blocking of this integrin may be an interesting therapeutically strategy in incisional hernia. <![CDATA[Outcome of pigs with short gut syndrome submitted to orthotopic intestinal transplantation]]> PURPOSE: To evaluate the current model of small bowel resection and intestinal transplantation in pigs. METHODS: Forty two Large White pigs were distributed in five groups: G1(n=6), G2(n=6) and G3(n=6) were submitted to 80%,100% and 100% plus right colon resection respectively and G4(n=7) and G5(n=5) to 100% SBR plus IT without and with immunosuppression based on Tacrolimus and Mycophenolic acid. Evaluation included weight control, clinical status, biochemical analysis and endoscopies for graft biopsies. Follow-up in G1 and 2 was 84 days, while in G3, four and five was ± three weeks. RESULTS: G1 increased weight suggesting adaptation while G2 and 3 loused weight and inadequate adaptation. G4 and 5 died of acute cellular rejection (ACR) and sepses respectively. Overall survival in G1, 2, 3, 4 and 5 at 30 days was 100, 100, 0 and 20 %, respectively. Medium survival in G4 and 5 was 14 and 16 days. CONCLUSIONS: The resection of 80% of small intestine in pigs is not suitable for short bowel syndrome induction. Intestinal transplantation with the proposed immunosuppression protocol was effective in prevent the occurrence of severe acute rejection, but inappropriate to increase recipients survival. <![CDATA[Study of the clinical and histopathological repercussions of the "omental band" in dogs' stomach]]> PURPOSE: To evaluate the efficacy of the "omental band" as a bariatric surgical technique. METHODS: A sample of 35 dogs was studied. The Test Group was composed by 20 dogs. Of these, six were observed by 10 days, six were observed by 20 days and eight were observed by 30 days of post-operatory. The Control Group was composed by 15 dogs. Of these, five were observed by 10 days, five were observed by 20 days and five were observed by 30 days of post-operatory. The weight loose was the variable utilized to the evaluation of the efficacy of the surgical technique described in this study, once all of the dogs were weighted in precision balance before the surgical act and at the end of the post-operatory observation period. RESULTS: At the end of the study it was observed that the weight loose of the dogs submitted to the "omental band's" surgical technique was meaningfully higher in comparison with the dogs of the Control Group at the end of the post-operatory observation period. CONCLUSION: The surgical technique of the "omental band" showed effective in dogs, once has proposed a meaningfully weight loose. <![CDATA[Portland cement <em>versus</em> MTA as a root-end filling material. A pilot study]]> PURPOSE: To assess periradicular lesions clinically and by computed tomography (CT) after endodontic surgery using either Portland cement or mineral trioxide aggregate (MTA) as a root-end filling material. METHODS: Three patients diagnosed with periradicular lesions by cone-beam CT underwent endodontic surgery with root-end filling. Patient A was treated with MTA as the root-end filling material, patient B was treated with Portland cement and patient C had two teeth treated, one with MTA and the other with Portland cement. Six months after surgery, the patients were assessed clinically and by CT scan and the obtained results were compared. RESULTS: Periradicular tissue regeneration was observed in all cases, with no significant differences in bone formation when comparing the use of MTA and Portland cement as root-end filling materials. CONCLUSION: Both mineral trioxide aggregate and Portland cement were successful in the treatment of periradicular lesions.