Resumo em Inglês:

ABSTRACT PURPOSE: To evaluate metabolic effects in experimental model of glucocorticoid-induced insulin resistance. METHODS: Twenty Wistar male rats were randomly divided into two groups, which were treated with intraperitoneally injected dexamethasone 1mg/Kg/day for ten days consecutively (Group D; n=10) and placebo (Group C; n=10). The variables analyzed were: from the first to the 10th day - body weight (before and after treatment); food and water daily consumption; on the 10th day - glycemia, insulinemia, HOMA-beta and HOMA-IR. The blood samples for laboratory analysis were obtained by intracardiac puncture. Also on the 10th day liver fragments were taken for analyzing glycogen and fattty. RESULTS: Group D animals compared to group C had: weight reduction (g), (D=226.5±24.7 vs C=295.0±25.4; p=0.001); increased glycemia (mmol/l) (D=19.5±2.1 vs C=14.2±3.1; p=0.0001); diminished insulinemia (mU/l) (D=0.2±0.1 vs C=2.0±0.4; p=0.0001); reduced HOMA-β (D=0.2±0.1 vs C=4.2±1.7; p=0.0002); diminished HOMA-IR (D=0.2±0.1 vs C=1.3±0.4; p=0.0002). Histological examination of the liver showed that 100% of group D and none of group C had moderate fatty. (p=0.2). CONCLUSION: Animals treated with glucocorticoid, in this experimental model, expressed hyperglycemia, hypoinsulinism and decreased peripheral insulin sensitivity.

Resumo em Inglês:

ABSTRACT PURPOSE: To investigate the protective effect of L-arginine on the prostate (nonneoplasic) of rats with radiation-induced injury. METHODS: Twenty-nine Wistar rats, male adult, allocated into three groups: Control group (C) was not exposed to irradiation (n=10); Radiated group (R) had undergone pelvic irradiation (n=10); Supplemented and radiated group (R+S) had undergone pelvic irradiation plus L-arginine supplementation (n=9). The animals were observed for signs of toxicity. After euthanization, the prostate was dissected under magnification and stained by hematoxylin and eosin to study acinar structures and stained with Picrosirius red for collagen analysis. RESULTS: After radiation exposure, all animals presented diarrhea, but supplementation with L-arginine reduced this effect. The weight gain in the R+S group was significantly higher than in the C and R groups. In the R+S group the collagen density and the prostate acinar area was similar to the R and C groups. Epithelial height was significantly reduced in group R compared with group C (p<0.0001). When comparing the group R+S with R, a statistical difference was observed to be present (p<0.0001). CONCLUSIONS: Pelvic radiation promotes systemic effects and some structural modifications in the ventral prostate of rats. These modifications can be prevented by oral supplementation with L-arginine.

Resumo em Inglês:

ABSTRACT PURPOSE: To investigate the severity of pancreatitis in lipoprotein lipase (LPL)-deficient hypertriglyceridaemic (HTG) heterozygous mice and to establish an experimental animal model for HTG pancreatitis study. METHODS: LPL-deficient HTG heterozygous mice were rescued by somatic gene transfer and mated with wild-type mice. The plasma amylase, triglyceride, and pathologic changes in the pancreas of the LPL-deficient HTG heterozygous mice were compared with those of wild-type mice to assess the severity of pancreatitis. In addition, acute pancreatitis (AP) was induced by caerulein (50 µg/kg) for further assessment. RESULTS: The levels of plasma amylase and triglyceride were significantly higher in the LPL-deficient HTG heterozygous mice. According to the pancreatic histopathologic scores, the LPL-deficient HTG heterozygous mice showed more severe pathologic damage than the wild-type mice. CONCLUSIONS: Lipoprotein lipase deficient heterozygous mice developed severe caerulein-induced pancreatitis. In addition, their high triglyceride levels were stable. Therefore, LPL-deficient HTG heterozygous mice are a useful experimental model for studying HTG pancreatitis.

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ABSTRACT PURPOSE: To develop a model for studying cerebrovascular disease prevention in elderly women. METHODS: Sixty 18-month-old Sprague Dawley (SD) rats were randomly divided into an estrogen administration group (EA, n=30) and a non-administration group (NA, n=30); thirty 4-month-old SD rats were allocated to a control group. The EA group received estradiol benzoate starting on the 5th day of a 34-day breeding period, and the serum levels of estradiol (E2), estrogen receptor (ER), and malondialdehyde (MDA) were measured. The MCA of each group was then sampled for viscoelastic experiments. RESULTS: The serum levels of E2 and MDA in the EA group showed significant differences compared to those in the control group (p<0.05), while the difference in ER between the EA and control groups was not significant (p>0.05). The decrease in MCA stress at 7,200 s and the increase in strain at 7,200 s in the EA group showed no significant differences compared to the control group (p>0.05). CONCLUSION: Estradiol administration inhibited the formation of lipid peroxidation products and restored middle cerebral arterial viscoelasticity in aged female rats.

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ABSTRACT PURPOSE: To investigate if the association of fat grafts and platelet-rich plasma (PRP) improves graft viability in female rats. METHODS: This is an experimental, randomized and blinded study, which involved 47 rats. Fat was harvested from the inguinal region and grafted to the cranial region. The experimental group consisted of PRP-enriched fat grafts (n=22) whilst the control group consisted of fat graft only (n=25). After a 100-day period, the animals were euthanised and the fat grafts were analyzed using scores from 0 (absent) to 4 (abundant), in optical microscopy by two independent and blinded pathologists. RESULTS: Regarding fat graft cell viability, the PRP group scored moderate/abundant in 63% of cases and the fat graft only group scored absent/slight in 72% of cases (p=0.03). The PRP group also presented lower fat necrosis scores when compared to the fat graft only group (p=0.03). Tumors (dermoid cysts) within the fat grafts were observed in three animals in which the grafts were mixed with PRP. CONCLUSION: Platelet-rich plasma improves the viability and integration of fat grafts in rats, but more studies are needed to fully understand the exact mechanisms that lead to this improvement and assess the safety of the method for use in humans.

Resumo em Inglês:

ABSTRACT PURPOSE: To evaluate the effect of remote ischemic preconditioning (IPC-R) in the fetal small bowel transplantation model. METHODS: Two groups were constituted: The Isogenic transplant (ISO, C57BL/6 mice, n=24) and the allogenic transplant (ALO, BALB/c mice, n=24). In each group, the animals were distributed with and without IPC-R. It was obtained the following subgroups: Tx, IPC-R, Fk, IPC-Fk, in both strains. Intestinal grafts were stained with hematoxylin and eosin and immunohistochemically. RESULTS: The graft development evaluation in ISO group showed that IPC-R reduced the development compared with ISO-Tx (5.2±0.4 vs 9.0±0.8) and IPC-R-Fk increased the graft development compared with IPC-R (11.2±0.7 and 10.2±0.8). In ALO group, IPC-Fk increased the development compared with ALO-Tx and ALO with IPC-R (6.0±0.8, 9.0±1.2, 0.0±0.0, 0.5±0.3). The PCNA expression was increased in ISO group treated with Fk and IPC-R compared to other groups (12.2±0.8 vs Tx: 8.8±0.9, IPC-R: 8.0±0.4 and Fk: 9.0±0.6). The graft rejection was lower in groups treated with IPC-R (-18%), Fk (-68%) or both (-61%) compared with ALO-Tx. CONCLUSION: Remote ischemic preconditioning showed benefic effect even associate with Tacrolimus on the development and acute rejection of the fetal small bowel graft in the Isogenic and Allogenic transplants.

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ABSTRACT PURPOSE: To investigate whether there is a difference between Marlex(r) and Dynamesh PP-light Marlex(r) meshes, in the abdominal wall defect correction, on rats in contaminated surgical site. METHODS: Twenty-eight Wistar rats were divided into two groups of 14, and four subgroups of seven animals. All subgroups underwent similar surgical procedure. One group received the mesh Marlex(r) and the other Dynamesh PP-light(r) for correction of the defect. Before implanting, the meshes went through a contamination process, on which was used standard solution containing 10 UFC of Escherichia coli. Fragments of the animal's abdominal wall received macroscopic, microscopic and microbiological analysis. RESULTS: There was no statistical significance in the analysis of macroscopic variables. Accentuated inflammatory process was shown in all subgroups. The foreign body type reaction was mild in all subgroups, except Dynamesh(r)-14, which was moderate with no statistical significance. The microbiological analysis of the meshes was also similar between the subgroups. CONCLUSION: There was no difference between the meshes of Marlex(r) and Dynamesh PP-light(r) in the ventral abdominal wall defect correction on rats in contaminated surgical site.

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ABSTRACT PURPOSE: To compare the two lines suture (total and seromuscular) after partial gastrectomy in normal and overweight rats. METHODS: Forty Wistar rats were distributed in two groups. Group A received normal diet; group B, normal diet and supplementation with saccharose in the water. When group B progressed to a statistically greater weight than the animals of group A, the experiment (sleeve-like gastrectomy) was conducted with gastrorraphy in two sutures lines (total and seromuscular).The animals were distributed into two subgroups of 10. A1 and A2 subgroups were sacrificed at 7 and 14 days postoperatively as well as B1 and B2. Mortality, morbidity, complications attributed to the gastric suture, biochemical dosages, Lee index, macroscopy, weight of retroperitoneal and gonadal fat, optical microscopy with hematoxylin-eosin and picrosirius-red, were the evaluation parameters. RESULTS: The overweight group achieved statistically greater weight after 16 weeks in induced obesity; there was no mortality or complications with clinical consequences attributable to morbidity. The overweight group had statistically greater weight of gonadal and retroperitoneal fat. The difference was observed in urea, albumin, total cholesterol and indirect bilirubin. CONCLUSION: There was no outcome difference between the overweight and non-overweight group in two suture lines in gastrorrhaphy after sleeve-like gastrectomy.

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ABSTRACT PURPOSE: To verify the publication rate of the abstracts presented at the XII Brazilian Congress of Experimental Surgery. METHODS: We performed a cross-sectional study that evaluated if the abstracts accepted for presentation at the XII Brazilian Congress of Experimental Surgery were published in periodics. The information was acquired using the Scielo, Medline / Pubmed, LILACS and Google Scholar databases. RESULTS: From all the abstracts presented, only 77 (40.52%) were published in scientific journals. Of this total, 14 (18.18%) were published prior to the conference 35 (45.45%) in the same year that occurred congress, 56 (72.72%) in the period 2011-2013 and 63 (81, 81%) between the Congress and the year 2015. Regarding the geographical distribution of summaries, 42 (22%) were from the northern region, 19 (10%) from the Northeast, 8 (4%) Midwest, 116 (61%) from the Southeast and 5 (3%) from the south. CONCLUSION: The publication rate of the abstracts presented at the XII Brazilian Congress of Experimental Surgery was 40,52%, most from the state of Sao Paulo.

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ABSTRACT PURPOSE: To critically analyze and standardize the rat pancreatectomy nomenclature variants. METHODS: It was performed a review of indexed manuscripts in PUBMED from 01/01/1945 to 31/12/2015 with the combined keywords "rat pancreatectomy" and "rat pancreas resection". The following parameters was considered: A. Frequency of publications; B. Purpose of the pancreatectomy in each article; C. Bibliographic references; D. Nomenclature of techniques according to the pancreatic parenchyma resection percentage RESULTS: Among the 468, the main objectives were to surgically induce diabetes and to study the genes regulations and expressions. Five rat pancreatectomy technique references received 15 or more citations. Twenty different terminologies were identified for the pancreas resection: according to the resected parenchyma percentage (30 to 95%); to the procedure type (total, subtotal and partial); or based on the selected anatomical region (distal, longitudinal and segmental). A nomenclature systematization was gathered by cross-checking information between the main surgical techniques, the anatomic parameters descriptions and the resected parenchyma percentages. CONCLUSION: The subtotal pancreatectomy nomenclature for parenchymal resection between 80 and 95% establishes a surgical parameter that also defines the total and partial pancreatectomy limits and standardizes these surgical procedures in rats.