Resumo em Inglês:

PURPOSE: To evaluate the effects of sucralfate on tissue content of neutral and acids mucins in rats with diversion colitis. METHODS: Thirty-six rats were submitted to a proximal right colostomy and a distal mucous fistula. They were divided into two groups according to sacrifice to be performed two or four weeks after intervention. Each group was divided into three subgroups according daily application of enemas containing saline, sucralfate at 1.0 g/kg/day or 2.0 g/kg/day. Colitis was diagnosed by histological analysis and neutral and acid mucins by Periodic Acid Schiff and Alcian Blue techniques, respectively. The contents of mucins were quantified by computer-assisted image analysis. Student's t paired and ANOVA test were used to compare the contents of both types of mucins among groups, and to verify the variance with time, establishing level of signification of 5% for both (p<0.05). RESULTS: Enemas containing sucralfate improves the inflammation and increases the tissue contents of neutral and acid mucins. The content of neutral mucins does not change with the time or concentration of sucralfate used, while acid mucins increases with concentration and time of intervention. CONCLUSIONS: Sucralfate enemas improve the inflammatory process and increase the tissue content of neutral and acid mucins in colon without fecal stream.

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PURPOSE: To evaluate the effect of exercise (swimming) on pregnancy in spontaneously hypertensive rats (SHR). METHODS: Thirty three pregnant female SHR were distributed into three groups (n=11 animals/group): SHR Control=non-exercised (sedentary); SHR Ex0 = exercised from day zero to day 20 of pregnancy; and SHR Ex7 = exercised from day 7 to 20 of pregnancy. Body weight and systolic blood pressure were indirectly measured during pregnancy. On gestational day 21, the rats were anaesthetized and uterine content was withdrawn for analysis of maternal reproductive outcome parameters and fetal development. RESULTS: The reduced blood pressure percentage was higher in SHR Ex0 and SHR Ex7 compared to SHR Control group. Weight gain was present in all pregnancy periods, but it was lower in SHR Ex7 than in SHR Control dams. The exercise increased the pre-implantation loss rate. The post-implantation loss rate was lower in SHR Ex0 group. SHR Ex7 group showed a significantly higher percentage of fetuses classified as small for gestational age as compared to others groups. CONCLUSION: The exercise contributed to lowering gestational blood pressure in SHR rats, but had a negative impact on the developing embryo.

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PURPOSE: The use of the collared peccary as an experimental model for ischemic nephropathy. METHODS: A total of 12 collared peccary (Tayassu tajacu) was used and ischemic nephropathy was induced in six of these animals that constituted the experimental group (G1) while the other six formed the control group (G2). Ischemic nephropathy was induced surgically by partial occlusion of the left renal artery. The disease course was assessed by hematological tests, serum chemistry, urinalysis, ultrasound (US) and doppler ultrasound function of the renal artery before induction, and at five, 10, 15 and 20 days after surgery. Twenty days after the occlusion, unilateral nephrectomy and histopathological examination were performed to assess renal morphology. RESULTS: Statistical analysis by Fischer's test showed a significant difference (p<0.05) between the control group and the experimental group. The histopathological examination showed glomerular, tubular and interstitial lesions. In the experimental group, 83.3% (5 /6) showed moderate renal lesions and only 16.7% (1/6) were classified with no lesions. The ultrasound examination of the right kidney presented statistical difference between day 5 and day 10 post occlusion. CONCLUSION: The collared peccary as a good experimental model for ischemic renal disease, because it could be manipulated during the research time without death, with health conditions that permit any subsequent procedure for disease therapy.

Resumo em Inglês:

PURPOSE: To evaluate surfactant protein A levels in an hepatopulmonary syndrome rat model. To date, there have been no studies aimed at evaluating surfactant levels in the setting of cirrhosis or hepatopulmonary syndrome. METHODS: A total of 35 rats were divided into control, sham, and experimental HPS groups. We evaluated surfactant protein A levels in rats and the experimental model designed to induce hepatopulmonary syndrome was common bile duct ligation. Statistical analysis was performed using GraphPad Prism Software(r). Differences were considered statistically significant when p<0.05. RESULTS: Lung homogenate of surfactant protein A levels were lower in the experimental hepatopulmonary syndrome and sham groups in comparison to the control group (p<0.05). Serum SP-A levels were the same in experimental hepatopulmonary syndrome and control groups but decreased in the sham group compared with the experimental groups (p<0.05). Myeloperoxidase activity was higher in the experimental hepatopulmonary syndrome group than the other two groups (p<0.05). CONCLUSION: Surfactant protein A is present in experimental hepatopulmonary syndrome and leads to an imbalance between serum and pulmonary levels due to systemic inflammatory response.

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PURPOSE: To investigate the osseointegration properties of prototyped implants with tridimensionally interconnected pores made of the Ti6Al4V alloy and the influence of a thin calcium phosphate coating. METHODS: Bilateral critical size calvarial defects were created in thirty Wistar rats and filled with coated and uncoated implants in a randomized fashion. The animals were kept for 15, 45 and 90 days. Implant mechanical integration was evaluated with a push-out test. Bone-implant interface was analyzed using scanning electron microscopy. RESULTS: The maximum force to produce initial displacement of the implants increased during the study period, reaching values around 100N for both types of implants. Intimate contact between bone and implant was present, with progressive bone growth into the pores. No significant differences were seen between coated and uncoated implants. CONCLUSION: Adequate osseointegration can be achieved in calvarial reconstructions using prototyped Ti6Al4V Implants with the described characteristics of surface and porosity.

Resumo em Inglês:

PURPOSE: To compare the biomodulatory effects of LED and ultrasound combined with semipermeable dressing in the repair of cutaneous lesions. METHODS: Eighty-four Wistar rats were submitted to surgical injury (2.5 cm) and divided into four groups (n=21): Group I (control), Group II (LED therapy, LED), Group III (LED therapy + dressing, LED+D) and Group IV (ultrasound + dressing, US+D). At seven, 14 and 21 days, the animals were euthanized, and the specimens of interest removed for histological analysis. RESULTS: Histological and histomorphometric analysis revealed a greater percent wound regression in animals receiving the dressing (group III: 55.97; group IV: 53.06), as well as a greater reduction in the inflammatory infiltrate (group III: 29.14; group IV: 31.71) since day 7. A later effect, with progression of the tissue repair process only after 14 and 21 days, was observed in the LED group intense fibroblast proliferation and greater collagen fiber production and organization were seen in the LED+D and US+D groups compared to the other groups. CONCLUSION: LED combined with a dressing was more effective at accelerating in the repair of cutaneous lesions.

Resumo em Inglês:

PURPOSE: To assess the evolution profile of the immunohistochemical expression of stromal constituents over the time-course of wound healing in a murine model. METHODS: Surgical wounds were performed in the back of 24 Wistar rats. After three, seven, 14 and 21 days, six rats were euthanized and the wounded histologically processed to assess the immunohistochemical expression of CD3, CD20, CD31, α-SMA and type-I collagen. Non-injured skin samples (NSS) were used as control. Data were subjected to statistical analysis using ANOVA and Tukey test. RESULTS: The mean of CD3 and CD20 positive cells in the wounds was significantly higher than in NSS at seven and 14 days (p<0.001). The blood vessels content was significantly lower than in NSS (p<0.05) at three days, but increased at seven and 14 days (p<0.01). The mean of α-SMA positive cells at seven, 14 and 21 days was higher than in NSS (p<0.05). The relative content of type I collagen increased from three to 21 days, but remained lower than in NSS (p<0.05). CONCLUSIONS: Lymphoid cells, myofibroblasts and microvessels contents varied over the time-course of wound healing, with peak at seven days and progressive reduction until 21 days. The type I collagen content increased over time.

Resumo em Inglês:

PURPOSE: To compare controlled liver regeneration in rats submitted to 60% hepatic resection having L-arginine supplemented diet, based on weight changes of the regenerated liver, laboratory parameters of liver function and pathological findings. METHODS: Thirty-six rats were divided into two groups, control and L- arginine. The first received standard chow and saline solution by gavage. The second had supplementation with L- arginine. Animals were killed on postoperative period at 24h, 72h and seven days. For analysis of liver regeneration was used Kwon formula for weight, laboratory tests and mitosis. RESULTS: Weight, showed no benefit with L- arginine supplementation; however, intergroup comparison in the first 24h observed positive effect on supplementation (p=0.008). Alkaline phosphatase was increased in arginine group (p<0.04). The number of mitoses showed no difference between the two groups; however, in the first 24 hours, the supplemented group had higher number of mitoses within the groups (p=0.03). CONCLUSION: Supplementation with L-arginine did not show benefits in liver regeneration; however, supplemented group in the first 24 hours showed benefits over 72 hours and seven days of the evaluation by weight gain and number of mitosis.

Resumo em Inglês:

PURPOSE: To evaluate the effects of duodenal-jejunal bypass (DJB) on serum and hepatic profiles of obese rats fed on a western diet (WD). METHODS: Twenty eight 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). Body weight, fat pad depots, glycemia, insulinemia, HOMA-IR, TyG, lipids profile and hepatic analyses were evaluated two months after surgery. RESULTS: The WD SHAM group presented greater obesity, hyperglycemia, hyperinsulinemia, insulin resistance, hypertriglyceridemia and hepatic steatosis than the CTL group. WD DJB rats presented decreased serum glucose and insulin resistance, when compared to WD SHAM animals, without changes in insulinemia. In addition, DJB surgery normalized serum TG and attenuated TG accumulation and steatosis in the liver of the WD DJB group. Hepatic ACC and FAS protein expressions were similar in all groups. CONCLUSION: Duodenal-jejunal bypass attenuates hepatic parameters of non-alcoholic fatty liver disease in obese rats fed on a western diet.

Resumo em Inglês:

PURPOSE: To evaluate the treatment outcome of severe peritonitis in rats with increasing age. METHODS: Thirty Wistar rats stratified in three groups: group I - six month-old; group II - 12 month-old; and group III - 18 month-old, underwent autogenously fecal peritonitis (6 ml/kg rat), and were treated with intravenous meropenem. The survival animals were followed-up for 45 days. The variables were expressed by their mean and standard error of the mean (SEM). p<0.05 was used for rejecting the null hypothesis. The study was approved by the Ethics Committee. RESULTS: There was a significant increase in the mortality and morbidity in elderly rats. Of interest, even among young survival rats presenting with severe residual abscesses both in the abdomen and thorax cavities, they present an almost normal life. CONCLUSIONS: The treatment of severe autogenously fecal peritonitis with intravenous meropenem reached reasonable results in rats with six and twelve months of age, even considering residual abscesses on abdomen and thorax cavities. However, the great majority (80%) of elderly rats could not overcome the initial severe infectious challenge, proving that ageing is a very important risk factor for impairing immune response. Thus, sepsis remains a challenging situation, especially in elderly.