Resumo em Inglês:

PURPOSE: To evaluate the benefit of using carriers such as the biopolymer gel (hidrogel of polysaccharide of sugarcane molasses) associated with the bone morphogenetic proteins (BMP's) in the repair of critical bone defects in calvaria of Wistar rats. METHODS: Forty-two rats were submitted to a surgical calvaria bone defects. These animals were divided into two experimental groups, positive control group and negative control group. The Group I the calvaria defect was filled up with biopolymer gel, biological membrane, BMP and lyophilized graft. The Group II was treated with biopolymer gel, BMP and lyophilized graft. And the group III (positive control group) was treated with BMP, lyophilized graft and biological membrane. In the negative control group (Group IV) a defect was made in the rat calvaria and the animals were sacrificed immediately after the surgery. The animals of experimental groups and positive control group were slaughtered after subsequent periods of 90 and 180 days. In these periods, the histological analysis and image assessment by cone bean tomographic imaging were obtained. RESULTS: There was highest bone tissue formation with statistically significant results in the groups that associated biopolymer gel and membrane (Group I), followed by the group III (BMP, lyophilized graft and biological membrane). The lower bone formation occurred in the group not using the sugarcane biopolymer gel (Group II). The radiolucent areas of the analyzes of 180 days among the groups studied were respectively, 14.98 mm², 26.65 mm² and 35.81 mm². CONCLUSION: The biopolymer gel showed to be an excellent bone morphogenetic protein carrier, probably by facilitating the controlled release of these proteins in the process of bone repair.

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PURPOSE: To evaluate the feasibility and safety of a new technique for laparoscopic segmental colectomy and primary anastomosis in the left colon of rats. METHODS: Thirty rats were randomly assigned to three groups of ten animals each. All animals underwent segmental resection of the left colon and end-to-end anastomosis. In Group I, the animals underwent laparoscopic surgery with carbon dioxide pneumoperitoneum at a pressure of 5 mmHg. In Group II, the animals underwent pneumoperitoneum with carbon dioxide at a pressure of 12 mmHg. In Group III, the control group, the animals underwent open surgery. All animals were reopened on the 7th postoperative day and were evaluated for peritonitis, abscesses, anastomotic dehiscence and bowel obstruction, and the anastomosis bursting pressure was measured. RESULTS: No obstructions, peritonitis or abscesses were found in any of the animals. An animal in Group I exhibited a blocked anastomosis leakage. The average anastomosis bursting pressure in the 30 animals was 187.02 ± 68.35 mmHg. There was no significant difference in the anastomosis bursting pressure among the groups (p = 0.503) CONCLUSION: The laparoscopic experimental model was feasible and safe for segmental colectomy and anastomosis of the left colon in rats.

Resumo em Inglês:

PURPOSE: To investigate the anti-inflammatory effects of simvastatin in rats undergoing one-lung ventilation (OLV) followed by lung re-expansion. METHODS: Male Wistar rats (n=30) were submitted to 1-h OLV followed by 1-h lung re-expansion. Treated group received simvastatin (40 mg/kg for 21 days) previous to OLV protocol. Control group received no treatment or surgical/ventilation interventions. Measurements of pulmonary myeloperoxidase (MPO) activity, pulmonary protein extravasation, and serum levels of cytokines and C-reactive protein (CRP) were performed. RESULTS: OLV significantly increased the MPO activity in the collapsed and continuously ventilated lungs (31% and 52% increase, respectively) compared with control (p<0.05). Treatment with simvastatin significantly reduced the MPO activity in the continuously ventilated lung but had no effect on lung edema after OLV. The serum IL-6 and CRP levels were markedly higher in OLV group, but simvastatin treatment failed to affect the production of these inflammatory markers. Serum levels of IL-1β, TNF-α and IL-10 remained below the detection limit in all groups. CONCLUSIONS: In an experimental one-lung ventilation model pre-operative treatment with simvastatin reduces remote neutrophil infiltration in the continuously ventilated lung. Our findings suggest that simvastatin may be of therapeutic value in OLV-induced pulmonary inflammation deserving clinical investigations.

Resumo em Inglês:

PURPOSE: To describe an animal model of rapid intravenous infusion with different volumes of crystalloid and discuss the clinical findings. METHODS: Fifty six male Wistar rats were used, divided randomly in seven groups (n = 8). The rats of groups 1 to 6 received lactated Ringer´s solution intravenously, in the rate of 25 ml/min, with different volumes proportional to blood volume (BV). The rats of group 0 were submitted to the same procedure, but did not receive the fluid (control group). The data included respiratory rate, heart rate, saturation of peripheral oxygen (SpO2) in two times (before and after the infusion), and upshots (respiratory arrest and death). Dunnett´s test and ANOVA were used. RESULTS: The clinical signs significantly changed in the 2, 2.5 and 3 fold BV groups. The respiratory arrest was observed in the 1.5, 2, 2.5 and 3 fold BV groups, but death was present only in 2.5 and 3 fold BV groups. CONCLUSIONS: The infusion of crystalloid in the same volume of blood volume did not cause significant variation in respiratory and heart rate, saturation of peripheral oxygen and did not induce respiratory arrest. The infusion of a volume of 3 fold blood volume was lethal to all animals.

Resumo em Inglês:

PURPOSE: To evaluate in a long term the morphometric and ultrastructural changes in seminiferous tubules (ST) of normal and diabetic rats, and to correlate any changes with animal age and diabetes duration. METHODS: Sixty male Wistar rats, three months-old, were randomly divided into two groups: 30 non-diabetic controls (N) and 30 alloxan untreated diabetic (D). After one, six and 12 months of follow-up or diabetes induction rats were sacrificed and the testes examined. Morphometric measures of the ST were performed by digital imaging analysis. ST ultrastructure was analyzed by transmission electron microscopy. RESULTS: Sustained hyperglycemic state was observed in all diabetic rats throughout the study. Serum testosterone was also significantly decreased in these animals. The diameter, total area, epithelium area and epithelium thickness of ST were lower and tubular density was higher in diabetic animals. Diabetic rats also showed ultrastructural changes compromising the whole testis including germ-, Sertoli-, and Leydig cells, and also the mithocondria and cellular nuclei. Most frequent of these consisted of vacuolization and/or accumulation of lipid droplets and electron dense dark material in cell cytoplasm and/or in membranes, cellular degeneration, and apoptosis. Non-diabetic control rats also showed testicular lesions that resemble to the diabetic lesions, although much less severe and with later onset in life of these animals. CONCLUSION: Histopathological changes observed in testes of normal and diabetic rats are closely related to the animal age and/or duration of the hyperglycemic state, being progressively more severe in animals sacrificed belatedly. These changes may play an important role in male infertility observed in diabetic subjects.

Resumo em Inglês:

PURPOSE: To evaluate the efficacy of surgical treatment for esophageal perforation. METHODS: A systematic review of the literature was performed. We conducted a search strategy in the main electronic databases such as PubMed, Embase and Lilacs to identify all case series. RESULTS: Thirty three case series met the inclusion criteria with a total of 1417 participants. The predominant etiology was iatrogenic (54.2%) followed by spontaneous cause (20.4%) and in 66.1% the localization was thoracic. In 65.4% and 33.4% surgical and conservative therapy, respectively, was considered the first choice. There was a statistically significance different with regards mortality rate favoring the surgical group (16.3%) versus conservative treatment (21.2%) (p<0.05). CONCLUSION: Surgical treatment was more effective and safe than conservative treatment concerning mortality rates, although the possibility of bias due to clinical and methodological heterogeneity among the included studies and the level of evidence that cannot be ruled out.

Resumo em Inglês:

PURPOSE: To investigate immunohistochemical aspects of the myenteric plexus of valves constructed in the colon of rats to verify whether any denervation occurs both at the operative site and in those areas adjacent to the third valve. METHODS: Thirty six male Wistar rats divided into the following three groups were used: Control Group (CG); Amputated Group (AG); Amputated Group with Valves (AGWV). In AG was held in the rectum amputation and the colon was sutured to the skin elaborating the perineal colostomy. In AGWV was held in the rectum amputation. A laparotomy was performed for the manufacture of valves (seromyotomy) in the colon. After this step, the colon was sutured to the skin elaborating the perineal colostomy. The density of the neural elements in the muscular wall as marked specifically using Protein Gene Product (PGP) 9.5 and utilising the proper tools of the KS300 software for measuring the area. From these measurements, a relation and three proportions were drawn and analysed according to the mean of the averages obtained from the measured images. RESULTS: Immunoexpression of PGP 9.5 demonstrated a total absence of neural elements and myenteric plexus at the valve site. The density of the neural elements in the circular muscular layer at sites adjacent to the 3rd valve was lesser, however, was not significantly different. CONCLUSION: The immunohistochemical study of valves constructed in the colon of rats submitted to abdominoperineal amputation and perineal colostomy revealed denervation at the seromyotomy site.

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PURPOSE: To investigate the effect of sildenafil citrate (SC) on skeletal muscle ischemia-reperfusion (IR) injury in rats. METHODS: Adult male Wistar rats were randomized into three groups: vehicle-treated control (CTG), sildenafil citrate-treated (SCG), and sham group (SG). CTG and SCG had femoral artery occluded for 6 hours. Saline or 1 mg/kg of SC was given 5.5 hours after occlusion. SG had a similar procedure without artery occlusion. Soleus muscle samples were acquired 4 or 24h after the reperfusion. Immunohistochemistry caspase-3 analysis was used to estimate apoptosis using the apoptotic ratio (computed as positive/negative cells). Wilcoxon rank-sum or Kruskal-Wallis tests were used to assess differences among groups. RESULTS: Eighteen animals were included in the 4h reperfusion groups and 21 animals in the 24h reperfusion groups. The mean apoptotic ratio was 0.18±0.1 for the total cohort; 0.14±0.06 for the 4h reperfusion groups and 0.19±0.08 for the 24h groups (p<0.05). The SCG had lower caspase-3 ratio compared to the control groups at the 24h reperfusion time point (p<0.05). CONCLUSION: Sildenafil citrate administration after the onset of the ischemic injury reduces IR-induced cellular damage in skeletal muscle in this rat hindlimb ischemia model.

Resumo em Inglês:

PURPOSE: To investigate the changes in the intestinal epithelium of rats, when submitted to the ischemia of varied time and scheduled reperfusion. METHODS: For this purpose, the following groups were established six groups: control, 10, 20, 30, 40, 60 minutes of ischemia and reperfusion time (24 hours). Their intestines being resected for histopathological analysis: the length and width of the villus, and mitotic index. The nonparametric test Kruskal-Wallis and multiple comparisons test were applied. RESULTS: The qualitatively the intestinal epithelium is regenerated when submitted to different ischemia, and 24 hours reperfusion time. It was observed that morphometry analyzing taking villus length and width and mitotic index as parameter, meaningful alterations were detected. CONCLUSION: The epithelium is regenerated, when subjected to different time planned of ischemia and reperfusion. It was observed: decrease the length and increase the width of the villi, when compared Group VI with I and II, and Group VI with I; increased mitotic index when compared Groups III with I. Every analysis was statistically significant.

Resumo em Inglês:

PURPOSE: To investigate morbidity, mortality and microbiological response to fecal peritonitis induced in Wistar rats with permanent bilateral carotid ligation (PBCL). METHODS: Fecal peritonitis was induced in 30 rats, with 10 animals in each group: Group1 - normal young animals; Group2 - normal mature animals; and Group3 - rats with PBCL after four months postoperative follow-up. Peritonitis was induced with 10% stool suspension. Morbidity and mortality were evaluated. The survival animals after seven days were euthanized for tests. For microbiological studies blood were collected from the carotids and right ventricle; and fragments of lung and peritoneum. RESULTS: The morbidity and mortality of young animals were significantly lower than in mature animals with and without PBCL. There was no difference in morbidity and mortality among mature rats with and without PBCL. The diversity of microorganisms producing septicemia was similar to native micro biota of the large bowel. CONCLUSIONS: The immune response was more efficient in young animals, represented by significant less morbidity and no natural mortality. PBLC did not affect morbidity and mortality in mature rats. The immune response to fecal peritonitis has age as an independent predictor.

Resumo em Inglês:

PURPOSE: To investigate abdominal wound healing using specific biomaterials in incisional hernias. METHODS: Incisional hernias were produced in 40 rabbits, after that they were reoperated with or without the use of meshes: PREMILENE® (PPL), ULTRAPRO® (UP), PROCEED® (PCD) or repairing without mesh (TRANSPALB). After 30 days a macroscopic and microscopic study of the part withdrawn from the abdominal wall was performed. RESULTS: Macroscopic: adhesion Area: PPL> UP and PCD (p = 0.031). Vascularization: PPL> UP and PCD (p = 0.001). PPL groups (p = 0.032) and PCD (p <0.001) showed greater meshes shrinkages when compared to UP. Microscopic: neutrophils: PCD> PPL, UP and TRANSPALB (p = 0.010); eosinophils: PPL> UP, and TRANSPALB PCD (p = 0.010); granulation tissue: PPL and PCD> UP and TRANSPALB (p <0.001); macrophages : PPL, UP and PCD> TRANSPALB (p <0.001); lymphocytes: PPL and PCD> UP (p = 0.009) and TRANSPALB (p <0.001); giant cells: PPL, UP and PCD> TRANSPALB (p <0.001); viscera adhered: PPL and UP> PCD and TRANSPALB (p <0.001). CONCLUSION: All types of meshes caused the formation of adhesions. The UP and PCD groups showed lower area and vascularization of the adhesions. The PPL and PCD groups showed higher meshes shrinkage and there was a predominance of acute inflammatory process in the PCD group.

Resumo em Inglês:

PURPOSE: To evaluate the frequency of obstructive sleep apnea (OSA) in obese patients scheduled for bariatric surgery and their identification for risk of OSA by Berlin Questionnaire (BQ) and excessive daytime sleepiness by Epworth Sleepiness Scale (ESS). METHODS: Fifty nine patients were evaluated by BQ and ESS. Out of these individuals, 35 performed a full-night sleep study using a type 3 portable monitoring (PM). The questionnaire results were compared for gender and BMI. The presence and severity of OSA was correlated with gender and both questionnaires. RESULTS: 94.75% of the respondents presented high risk for OSA by BQ and 59.65% presented positivity by ESS. Taking into account the AHI> 5 per hour for OSA diagnosis, all of them presented OSA, average AHI of 45.31±26.3 per hour and 68.6% have severe OSA (AHI>30). The male patients had a higher AHI (p<0.05). There was a positive correlation between the positivity in both questionnaires as well as the severity of OSA measured by AHI (p<0.05). CONCLUSION: The frequency and severe obstructive sleep apnea in the studied group is high. The Berlin Questionnaire and Epworth Sleepiness Scale had a positive correlation with the diagnosis of OSA in the group studied.