Resumo em Inglês:

Abstract Purpose: To evaluate the effects of duodenal-jejunal bypass (DJB) on the diaphragm muscle of obese rats fed on a western diet (WD) . Methods: Eighteen male Wistar rats were fed a standard rodent chow diet (CTL group) or WD ad libitum. After 10 weeks, WD rats were submitted to sham (WD SHAM) or duodenal-jejunal bypass (WD DJB). The structure, ultrastructure, collagen content and the morphometry of the neuromuscular junctions (NMJs) were analyzed two months after surgery. Results: WD SHAM rats displayed an increase in body weight, the Lee index and retroperitoneal and peri-epididymal fat pads compared to the CTL group. DJB did not alter these parameters. The muscle fiber structure and NMJs were similar in the WD SHAM and CTL groups. However, the WD SHAM group showed alterations in the fiber ultrastructure, such as loosely arranged myofibrils and Z line disorganization. In addition, WD SHAM animals presented a considerable amount of lipid droplets and a reduction in the percentage of collagen compared to the CTL group. DJB did not affect the structure or ultrastructure of the muscle fibers or the NMJs in the diaphragm of the WD DJB animals. Conclusion: Duodenal-jejunal bypass did not improve the alterations observed in the diaphragm of western diet obese-rats.

Resumo em Inglês:

Abstract Purpose: To evaluate a model for studying the toxicity in nervous tissue and meninges using ultrasound to guide needle insertion into the subarachnoid space of rabbits, with the objective of avoiding injuries triggered by the puncture and by intraneural injection of solutions. Methods: Forty-five adult female rabbits were divided into 3 groups (G): G1 underwent subarachnoid puncture, G2 underwent subarachnoid injection of saline solution and G3 underwent subarachnoid injection of 0.5% hyperbaric bupivacaine. A needle was inserted into the S1-S2 subarachnoid space guided by ultrasound. The sensitivity and motility of the animals were evaluated for 3 days, after which the animals were sacrificed for removal of lumbar and sacral portions of the spinal cord for histological examination by light microscopy and immunohistochemistry. Results: All animals had motor function and pain sensitivity on the evaluation period. No animal had complication during or after the procedures. Conclusion: Ultrasound is a useful and safe method for the correct identification of the subarachnoid space of rabbits.

Resumo em Inglês:

Abstract Purpose: To assess the effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative adhesion in animal models. Methods: Sixty males Albino Wistar rats aged 5 to 6 weeks were classified into five groups receiving none, heparin, PRP, silver nanoparticles, PRP plus silver nanoparticles intraperitoneally. After 2 weeks, the animals underwent laparotomy and the damaged site was assessed for peritoneal adhesions severity. Results: The mean severity scores were 2.5 ± 0.9, 2.16 ± 0.7, 1.5 ± 0.5, 2.66 ± 0.88, and 2.25 ± 0.62 in the control, heparin, PRP, silver and PRP plus silver groups, respectively with significant intergroup difference (p = 0.004). The highest effective material for preventing adhesion formation was PRP followed by heparin and PRP plus silver. Moreover, compared to the controls, only use of PRP was significantly effective, in terms of adhesion severity (p = 0.01) . Conclusion: Platelet-rich plasma alone may have the highest efficacy for preventing postoperative peritoneal adhesions in comparison with heparin, silver nanoparticles and PRP plus silver nanoparticles.

Resumo em Inglês:

Abstract Purpose: To investigate whether modulating NRG1 could attenuate diabetic neuropathic pain and analyze the underlying mechanism. Methods: Male SD rats were randomly divided into control group, diabetic group, NRG1 intervention group. After STZ-induced 2 weeks, NRG1 intervention daily for consecutive 7 days. 4 weeks after NRG1 intervention, both the mechanical withdrawal threshold and the morphological changes of the dorsal root ganglion and sural nerve were observed. Meanwhile, the expression of NGF, IL-1β, TNF-α in spinal cord were determined. Results: Compared with the diabetic group, NRG1 treatment improved the mechanical withdrawal threshold in diabetic rats, pathological changes of dorsal root ganglion and sural nerve were alleviated by NRG1 treatment with electron microscopy imagine. Moreover, compared with the control group, the expression of NGF was significantly decreased and the production of IL-1β, TNF-α were markedly induced in diabetic group. Furthermore, NRG1 treatment could normalized the above effect as compared to diabetic group. Conclusion: NRG1 exerted positive effects on the behavioral and pathological changes of rats with STZ-induced diabetic neuropathic pain, the underlying mechanism might be related to the promotion of NGF excretion and the inhibition of inflammatory cytokines excretion.

Resumo em Inglês:

Abstract Purpose: To evaluate the expression of endothelial and inducible NOS in addition to the miRNA-27b in the corpus cavernosum and peripheral blood of healthy rats, diabetic rats, alcoholic rats and rats with both pathologies. Methods: Forty eight Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D) and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study protein expressions of eNOS and iNOS by immunohistochemistry and expression of miRNA-27b in the corpus cavernosum and peripheral blood. Results: Immunohistochemistry for eNOS and iNOS showed an increase in cavernosal smooth muscle cells in the alcoholic, diabetic and alcoholic-diabetic groups when compared with the control group. Similarly, the mRNA levels for eNOS were increased in cavernosal smooth muscle (CSM) in the alcoholic, diabetic and alcoholic-diabetic groups and miRNA-27b were decreased in CSM in the alcoholic, diabetic and alcoholic-diabetic groups. Conclusion: The major new finding of our study was an impairment of relaxation of cavernosal smooth muscle in alcoholic, diabetic, and alcoholic-diabetic rats that involved a decrease in the nitric oxide pathway by endothelium-dependent mechanisms accompanied by a change in the corpus cavernosum contractile sensitivity.

Resumo em Inglês:

Abstract Purpose: To evaluate the effect of oxacillin bonded to magnetic nanoparticles in local infection model in rat. Methods: Twelve Wistar rats weighing 290±18g were randomly divided into four groups (n=6, each) and all rats had a magnet ring sutured on their right thighs. In the biodistribution group rats 0.1mL of 99mTc-magnetite (0.66 MBq) was injected i.v and after 30 minutes, biodistribution of 99mTc-magnetite was evaluated in right and left thighs. The other groups were inoculated with MRSA in each thigh muscles. Group 1 rats were injected i.v. with magnetite, group 2 with Magnetite + Oxacillin, group 3 with saline twice a day. After 24 hours samples of muscle secretion were harvested for microbiological analysis; muscle, lungs and kidneys for histology. Results: 99mTc-magnetite uptake was three-fold higher in right thigh muscles (with external magnet) than in the left. In magnetite and oxacillin-magnetite groups, bacterial/CFU was significantly lower in thigh muscles than in saline-controls. The inflammatory reaction in muscles and lungs was significantly lower in oxacillin-magnetite group-rats than in other groups (p<0.001) . Conclusion: This study confirms the potential antimicrobial activity of magnetic nanoparticles for Methicillin-Resistant S. aureus strains, which in addition to concentrate the antibiotic at the infection site, positively influenced the treatment.

Resumo em Inglês:

Abstract Purpose: To compare the use of a new cyanoacrylate-based surgical glue and suture with sepa-rate points in skin wounds closure. Methods: Thirty-six rats were subjected to a 4cm dorsal longitudinal incision. Twelve were sub-jected to simple suture with polyamide 6-0, 12 rats underwent wall synthesis using Dermabond(r) and 12 was performed cutaneous synthesis with N-2-Butyl-Cyanoacrylate. Twelve of each group was euthanized on the seventh postoperative day, their blood was taken to biochemical tests and a layer of skin and subcutaneous tissue surrounding the surgical scar was randomly divided in two segments, to the submission of tension tests and to histological study. Results: There were no significant difference between groups (p>0.05). In the soft dermis there was more type I collagen production in group I (p<0.05), group II and III was similar re-sults (p>0.05). In the compact dermis, all 3 groups showed similar results (p>0.05). The biomechanical study was similarity between the glue groups (p>0.05) but the group III proved to be different from the others having a higher resistance (p>0.05) . Conclusion: This glue does not cause any inflammation or kidney and hepatic toxicity. Polyamide sutures are more resistant and the glue should be used alone only in less tension are-as.

Resumo em Inglês:

Abstract Purpose: To evaluate the inflammatory intensity and measure the tissue content of the proteins claudin-3 and occludin in the colonic mucosa without fecal stream submit to intervention with curcumin. Methods: Thirty-six rats were submitted to a proximal colostomy and a distal mucous fistula and divided into two groups according to sacrifice to be performed two or four weeks. Each group was divided into three subgroups according daily application of enemas containing saline, curcumin at 50 mg/kg/day or 200 mg/kg/day. Colitis was diagnosed by histological analysis. Claudin-3 and occludin were determined by immunohistochemistry. The tissue content of claudin-3 and occludin were quantified by computer-assisted image analysis. Mann-Whitney, Student t and ANOVA tests were used to analyze the results establishing the level of significance of 5% for both (p<0.05). Results: Curcumin at both concentrations reduces the inflammation and preserves the tissue content of the proteins claudin-3 and occludin, which was related to the concentration used and to the time of the intervention. Conclusion: The application of enemas with curcumin reduces inflammation and preserves the tissue content of the proteins claudin-3 and occludin in the colonic mucosa devoid from the fecal stream.

Resumo em Inglês:

Abstract Purpose: To evaluate whether undergraduate students feel motivated to develop surgical skills and know their impression about the importance of having a surgical technique discipline in the curriculum of a medical school. Methods: A prospective study including three classes in a row, from the 8th period (n = 265) evaluated the knowledge acquired at the Center of Experimental Surgery, Department of Surgery, School of Medicine of Federal University of Rio de Janeiro (UFRJ). The importance of the discipline for medical training as a way of encouragement to arouse and deepen the interest in surgical technique was emphasized. The questions were scored from 1 to 5 (worst to best grade) . Results: Concerning the importance of the discipline for medical training, 78% and 18% of the students assigned a score 5 and 4, respectively. Regarding the stimulus to improve their surgical technical skills, 40% and 32% attributed the score 5 and 4, respectively. Conclusion: Undergraduate students from the Medical School of UFRJ effectively shared the understanding that the operative technique bases improve the formative process with significant impact, not only in the development of skills, but also to arouse vocations and stimulate new attitudes aimed to knowledge acquirement in the field of Surgery.

Resumo em Inglês:

Abstract Purpose: To develop a model of gastroenterostomy and to analyze the acquisition of skills after training by simulation. Methods: Experimental longitudinal study and of a quantitative character. The sample consisted of twelve general surgery residents from four hospitals. The training consisted of making ten anastomoses divided equally into five sessions and it took place over a period of six weeks. The evaluation of the anastomoses considered the time and the analysis of the operative technique through the global evaluation scale Objective Structured Assessment of Technical Skills (OSATS). Results: Residents showed a reduction in operative time and evolution in the surgical technique statistically significant (p<0.01). The correlation index of 0.545 and 0.497 showed a high linear correlation between time variables and OSATS. Conclusion: The preparation of ten gastroenterostomies is an exercise capable of transferring basic and advanced skills in laparoscopy through a standardized training using synthetic organs and a simulator.