Resumo em Inglês:

ABSTRACT PURPOSE: To compare bone healing in mandibular vertical body osteotomies (MVBO) after fixation with a resorbable 2.0mm-profile fixation system in the first and third postoperative months in rabbits. METHODS: Twenty hemimandibles of ten rabbits were divided into two groups according to duration of resorbable fixation-one or three months. The MVBOs were performed and one four-hole, resorbable, 2.0mm mini-plate fixation system was used on each side. The computed tomography (CT) scans, scanning electron microscopy (SEM), and histomorphometric outcomes of groups I and II were compared. RESULTS: Significant differences were found between the one- and three- month assessments in terms of newly formed bone ratio values (p<0.05). There was more new bone formation at the third month on both the CT and histomorphometric examinations. A better adaptation of the bone tissues to the resorbable mini-plate and screws was observed on SEM at three months. CONCLUSION: The resorbable mini-plates provided a fixation stable enough to allow immediate oral alimentation and callus formation in both groups.

Resumo em Inglês:

ABSTRACT PURPOSE: To develop an experimental model for incisional hernias and to compare morphological and functional aspects of hernia repairs by suture, polypropylene mesh and collagen mesh. METHODS: A defect measuring 7cm x 2cm was created in the anterior abdominal of 28 New Zealand male rabbits, divided into four groups (n = 7): (1) control, (2) suture of the anterior sheath of the rectus abdominal muscle, (3) setting of polypropylene mesh, and (4) setting of collagen mesh. On the 90th postoperative day, the animals were examined to verify the presence of incisional hernia. Samples of abdominal wall and scar were collected for histological study. RESULTS: Incisional hernia was identified in 85.7% of the control group, 57.1% of the suture group, 42.9% of the collagen mesh group, and none in the polypropylene mesh group (p = 0.015). Mesh exposure could be identified in 71.4% of the animals in group 3 and in no animal in group 4 (p = 0.021). The polypropylene mesh is effective in the treatment of abdominal wall defects, causing an intense inflammatory reaction. CONCLUSION: The collagen mesh is biocompatible, producing a minimal inflammatory reaction, but fails in the treatment of abdominal wall defects.

Resumo em Inglês:

ABSTRACT PURPOSE: To evaluate the efficacy of ethyl-cyanoacrylate in the treatment of fístula-in-ano in rats with and without prior seton placement. METHODS: Thirty rats Wistar with fístula-in-ano produced surgically, distributed in three groups: group A (ethyl-cyanoacrylate) - treated by application of ethyl-cyanoacrylate into fístula tract; group B (seton + ethyl-cyanoacrylate) - seton placement followed by application of ethyl-cyanoacrylate into fístula tract, 30 days later; group C (control) - no treatment. After 60 days the animals were submited to euthanasia and the specimens were analyzed by pathologist. The results were analyzed by Chi-square test with significant value of p<0.05. RESULTS: One animal of group B died. Were found tracts fully healed: 7, 5 and 2, in groups A, B and C, respectivelly. There was a statistically significant difference between groups A and C (p=0.02). When joined all animals treated with glue (A + B) compared to group C there was also statistically significant difference (p=0.02). CONCLUSIONS: The use of ethyl-cyanoacrylate glue was effective in closing anal fistulae in rats. There was no advantage in the prior application of seton.

Resumo em Inglês:

ABSTRACT PURPOSE: To investigate the regulatory roles of neutrophil elastase (NE) and matrix metalloproteinase-9 (MMP-9) in lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. METHODS: To construct LPS-induced ALI mouse models, wild-type C57BL/6 mice were administered 5.0 mg/kg of LPS through endotracheal, and/or 1.0 mg/kg of ONO-5046, and/or 20.0 mg/kg of chemically modified tetracycline-3 (CMT-3) by gavage. The levels of MMP-9, tissue inhibitor of metalloprotease-1, interleukin (IL)-6 were detected by real time RT-PCR at 6 h, 24 h and 48 h, and tumor necrosis factor (TNF), lung wet-dry weight ratio, white blood cell (WBC) count and polymorphonuclear (PMN) count in bronchoalveolar lavage fluid (BALF) were tested at 48 h after administration. The 5-day survival analysis of the ALI mice was also performed. RESULTS: Both ONO-5046 and CMT-3, regardless of being used individually or combined, significantly reduced the levels of MMP-9, IL-6, and TNF in lung tissue as well as in BALF, and the WBC and PMN count in BALF. Combined treatment with ONO-5046 and CMT-3 remarkably improved the survival rate of ALI mice. CONCLUSION: Neutrophil elastase synergizes with matrix metalloproteinase-9 to promote and regulate the release of inflammatory mediators and the infiltration of inflammatory cells, consequently affecting the survival of lipopolysaccharide-induced acute lung injury mice.

Resumo em Inglês:

ABSTRACT PURPOSE: To investigate the potential efficacy of beractant (Survanta(r)) and Seprafilm(r) on the prevention of postoperative adhesions. METHODS: Forty Wistar-albino female rats were used. The rats were randomly allocated into four groups of 10 rats each as control group (CG), beractant group (BG), Seprafilm(r) group (SG), and combined group (COG). All rats underwent cecal abrasion via midline laparotomy. Before abdominal closure, isotonic saline, beractant, Seprafilm, and combined agents were intraperitoneally administered. Adhesions were classified macroscopically with Canbaz Scoring System on postoperative day 10. Ceacum was resected for histopathological assessment. RESULTS: Macroscopic adhesion scores were significantly lower in BG, SG, and COG than CG (p<0.05); (45%, 15%, 25%, and 15%; respectively). Histopathological assessment revealed a reduced inflammation and fibrosis score in the study groups than CG (p<0.05). In BG, adhesion development, inflammation and fibrosis scores were lower than SG; however, it was not statistically significant. CONCLUSIONS: Intra-abdominal application of beractant is significantly effective for the prevention of adhesion formation with no adverse effect by covering the whole peritoneal mesothelium with excellent gliding properties in a rat model. The combination of both agents is also effective in reducing adhesion formation, however, not superior to single beractant application.

Resumo em Inglês:

ABSTRACT PURPOSE: To investigate the therapeutic effects of ellagic acid on L-arginin ınduced acute pancreatitis in rats. METHODS: Thirty-two were split into four groups. Group 1 (control) rats were performed only laparotomy, no drugs were administered. Group 2 (control+EA) rats were administered 85mg/kg EA orally. Rats were sacrificed by cardiac puncture 24 hours after the administration. Group3 (AP) 24 hours after intraperitoneal L-arginine administration, rats were sacrificed by cardiac puncture. Group 4 (EA)-(AP): 85mg/kg EA was administered orally after the L-arginine administration. 24 hours later, rats were sacrificed by cardiac puncture. Serum TNF-α, IL-1β, IL-6, total oxidative status (TOS), total antioxidant capacity (TAC), amylase levels were determined in all groups. RESULTS: Group 3 (AP) rats showed significantly raised TOS level as compared to Group1 (control) rats (p<0.001). Following the EA therapy, a decrease in TOS was observed in Group 4 (AP+EA). TAC levels were significantly raised in the Group 4 (AP+EA) compared to the Group 3 (AP) (p=0.003). Group 3 (AP) showed significantly increased TNF-α, IL-1β and IL-6 serum levels as compared to Group 4 (AP+EA). Histopathological changes were supported our result. CONCLUSION: The healing effects of ellagic acid on inflammatory and oxidative stress were confirmed by histopathological and biochemical evaluations of the pancreatic tissue.

Resumo em Inglês:

ABSTRACT PURPOSE: To evaluate the effect of Schinus terebinthifolius Raddi (aroeira) and Orbignya phalerata Mart. (babassu) in the healing process of cecorrhaphy in rats. METHODS : Fifty four rats were used, distributed into three groups randomly: aroeira, babassu and control, which were divided into three subgroups (six animals) according to the time of the deaths (7, 14, 21 days). All underwent the same surgical procedure, cecotomy and cecorrhaphy. The animals in group aroeira and babassu received daily dose of 100 mg/kg of hydroalcoholic extract and 50 mg/kg of aquous extract respectively, by gavage. The control group received only saline solution. The parameters evaluated were: macroscopic changes, ,resistance test to air insufflations and histological changes. RESULTS : All animals showed good healing without infection. All groups presented adhesions between cecum and neighboring organs. The resistance test insufflating of atmospheric air showed progressive increase of pressure according to the days in the aroeira group, and decrease in babassu group, without significant difference. Microscopy showed significant difference in the polymorphonuclear, hyperemia, angiogenesis, fibroblast proliferation and collagen histological variables in the 14th day. CONCLUSION : Hydroalcoholic extract of aroeira and the aqueous extract of babassu favored the healing process in cecorrhaphy in rats.

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ABSTRACT PURPOSE: To investigate the protective effect of metformin on testicular ischemia/reperfusion (I/R) injury in rats. METHODS: Eighteen adult male Wistar rats were randomly divided into three experimental groups (n=6), as follows: Sham, I/R, and Metformin. 1-hour ischemia was induced by the left testicular artery and vein clipping followed by 7 days of reperfusion. Metformin (100 mg/kg) was administrated orally for 7 days via oral gavage after ischemic period. At the end of trial, the left testis was removed for histological analysis and oxidative stress measurement. RESULTS: I/R reduced superoxide dismutase (SOD) activities and testicular Johnsen's scores accompanied by an elevation in malondialdehyde (MDA) and myeloperoxidase (MPO) levels in comparison with the sham group (P < 0.05). Compared to I/R group, metformin restored testicular Johnsen's scores, SOD activity, MDA and MPO levels (P < 0.05). CONCLUSION: Metformin has a protective effect against I/R injury on the testis.

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ABSTRACT PURPOSE: To evaluate the effect of Otostegia persica (O. persica) extract on renal damage induced by ischemia/reperfusion (I/R) in diabetic rats. METHODS: Forty-eight rats were subjected to right nephrectomy; then, they were allocated into six groups: Sham; Diabetic sham; I/R; Diabetic I/R; I/R+O. persica; Diabetic I/R+O. persica. Diabetes was induced by streptozotocin (200 mg/kg, i.p.). O. persica (300 mg/kg/day, p.o) was administered for 2 weeks. On the 15th day, ischemia was induced in left kidney for 60 min, followed by reperfusion for 24h. Renal functional and biochemical markers were estimated. RESULTS: I/R in both normal and diabetic rats, induced a significant elevation in serum levels of urea and creatinine (p<0.05). Renal I/R induced a significant increase of malondialdehyde, myeloperoxidase and nitric oxide concentrations associated with significant reduction in superoxide dismutase and catalase activities in comparison with the sham group (p<0.05). Diabetic rats that underwent renal I/R exhibited a significant increase in all the studied parameters with a reduction in the antioxidant enzymes as compared to nondiabetic rats (p<0.05). These deleterious effects associated with renal I/R were improved by the treatment with O. persica (p<0.05). CONCLUSION: Otostegia persica pretreatment protected the renal injury from ischemia-reperfusion in diabetic rats.

Resumo em Inglês:

ABSTRACT PURPOSE: To evaluate the clinical applicability of Pozzolana Biologic Silva cement (PBS(r)) in endodontic surgery. METHODS: Persistent apical periodontitis was diagnosed in 30 teeth of 12 patients by cone-beam computed tomography (CT). All patients had 2 or 4 affected teeth and underwent endodontic surgery with root-end filling. Patients with 2 affected teeth had one tooth (control) treated with mineral trioxide aggregate (MTA-Angelus(r)) as a root-end filling material, and the other tooth treated with PBS (experiment). When the patient had four affected teeth, two of them were treated with MTA and two with PBS. Six months after surgery, all patients were assessed by CT scan. Between-group comparisons of measurements were performed using the Wilcoxon test. RESULTS: Periradicular tissue regeneration was observed in all cases. Significant within-group differences in long axes of the lesion were found in the bucco-palatal direction (PBS group, p=0.0012; MTA group, p=0.024) and coronal-apical direction (PBS group, p=0.0007; MTA group, p=0.0015) between pre- and postoperative measurements. CONCLUSIONS: Pozzolana Biologic Silva cement can be used in the treatment of persistent periradicular lesions. The clinical use of PBS as a root-end filling material may be an alternative to MTA. PBS has additives, which provide enhanced strength.