Purpose: Quantify the levels of oxidative DNA damage of epithelial colon cells comparing segments with and without fecal stream. Methods: Sixty Wistar rats were subjected to deviation of fecal stream by proximal colostomy and a distal mucosal fistula. Animals were divided into three experimental groups that were sacrificed 6, 12 and 24 weeks after surgery. In each experimental group, five animals underwent laparotomy without intestinal deviation (sham subgroup). The diagnosis of colitis was made by histopathological analysis and the inflammatory activity index by graduated scale. The neutrophil infiltration was determined by myeloperoxidase tissue levels and the intensity of oxidative DNA damage by comet assay. The Mann-Withney and Student t test were used to compare the results among experimental subgroups and the Kruskal-Wallis test for variance analysis, adopting a significance level of 5% (p<0.05). Results: Colon segments without fecal stream was shown higher histological inflammatory score of the colon wall after 12 and 24 weeks (p=0.001) that increased with the time of diversion (p=0.01). The activity of myeloperoxidase in segments without fecal stream decreased with the time (p=0.001). Oxidative DNA damage levels were significantly higher in the segments without fecal stream, (p=0.0001), independent of time of colon diversion, and increase with the time (p=0.0007). Conclusions: Colon segments without fecal stream showed high levels of oxidative DNA damage related to histological alterations observed in diversion colitis. The levels of oxidative DNA damage in segments devoid of the fecal stream increase with the time of intestinal exclusion. Key words: Colitis. Colostomy. DNA Damage. Oxidative Stress. Comet Assay. Fatty Acids, Volatile. Rats. RESUMOObjetivo: Quantificar os níveis de dano oxidativo ao DNA em células epiteliais da mucosa cólica comparando segmentos com e sem trânsito fecal. Métodos: Sessenta ratos Wistar foram submetidos à derivação do trânsito intestinal por colostomia proximal e fístula mucosa distal. Os animais foram divididos em três grupos experimentais segundo terem sido sacrificados 6, 12 e 24 semanas após a cirurgia. Em cada grupo experimental, cinco animais foram submetidos à laparotomia isolada sem derivação fecal (grupo sham). O diagnóstico de colite foi estabelecido por análise histopatológica e o índice de atividade inflamatória por escala graduada. A infiltração neutrofílica foi determinada pelos níveis teciduais da mieloperoxidase e a intensidade do dano oxidativo ao DNA pelo ensaio em cometa. Utilizaram-se os testes de Mann-Withney e o teste t de Student para comparar os resultados encontrados entre os subgrupos experimentais e o teste de Kruskal-Wallis para análise de variância, adotando-se nível de significância de 5% (p<0,05). Resultados: Os segmentos cólicos, sem trânsito fecal apresentaram maior escore histológico de inflamação após 12 e 24 semanas (p=0,001), que aumentou com o tempo de derivação (p=0,01). A atividade da mieloperoxidase nos segmentos sem trânsito...

Purpose:To quantify the intensity of the expression of neutral and acids mucins in mucosa of the colon with and without fecal stream and to correlate this with the duration of fecal transit diversion. Methods: Thirty male Wistar rats were subjected to fecal transit deviation in the left colon by a proximal colostomy and a distal mucous fistula. The animals were divided into three experimental groups, according to whether sacrificing would be performed six, 12 or 18 weeks after surgery. The expression of neutral and acid mucins was evaluated using the histochemical techniques of Periodic Acid Schiff and Alcian Blue, respectively. The tissue mucins expression was quantified by computer-assisted image analysis software (NIS-Elements) in the segments with and without fecal stream. Student's paired t test was used to compare the quantities of mucins in colon with or without fecal stream and variance between the experimental groups by ANOVA and Newman-Keuls post-test, establishing level of signification of 5% (p<0.05). Results: There were significant decreased quantities of acid and neutral mucins in the colon without transit, compared with the colon with fecal stream, independent of the duration of exclusion. There was increased expression of neutral mucins in the colon with fecal stream after 12 and 18 weeks of exclusion. There was no increase in the expression of acid mucins in the colon with transit as the duration of fecal transit exclusion progressed. There was increased production of acid mucins in the animals submitted to diversion of the fecal stream for 18 weeks, compared with those subjected to diversion for 6 and 12 weeks. In the colon without fecal stream, there was increased expression of neutral mucins after 12 and 18 weeks of exclusion. Conclusions: Deviation of the fecal stream decreased the expression of acid and neutral mucins in the segments without fecal transit, compared with segments with transit. Regardless of the reduced expression of acid and neutral mucins in the segments without fecal stream, their tissue expression increased with increasing duration of intestinal deviation. Key words: Colitis. Colostomy. Mucins. Sialomucins. Image Processing, Computer-Assisted. RESUMOObjetivo: Quantificar a intensidade de expressão de mucinas neutras e ácidas na mucosa cólica provida e desprovida de trânsito intestinal relacionando-a ao tempo de exclusão fecal. Métodos: Trinta ratos Wistar machos foram submetidos à derivação do trânsito no cólon esquerdo por colostomia proximal e fístula mucosa distal. Os animais foram divididos em três grupos experimentais segundo o sacrifício ter sido realizado seis, 12 e 18 semanas após a cirurgia. A avaliação da expressão de mucinas neutras e ácidas na mucosa cólica foi realizada com as técnicas histoquímicas do Periódico Ácido de Schiff e Azul de Alcian, respectivamente. A quantificação da expressão tecidual das mucinas foi com auxílio de programa de análise de imagem assistida por computador (NIS-Elements) nos segmentos providos e desprovidos de trânsito fec...

PURPOSE: To quantify the intensity of sulfomucin and sialomucin expression in the colon mucosa, by means of computer-assisted image processing, comparing segments with and without fecal stream and correlating with the duration of fecal transit exclusion. METHODS: Forty-five Wistar rats were subjected to diversion of the fecal stream in the left colon by means of constructing a proximal colostomy and distal mucosal fistula. They were distributed randomly into three experimental groups of 15 animals, of which 10 were subjected to colon diversion (experimental subgroup) and five were only subjected to laparotomy, without colon diversion (control subgroup). The three experimental groups were formed according to the sacrifice date, which was to be performed six weeks after the surgical procedure (Group A), 12 weeks (Group B) and 18 weeks (Group C). The sulfomucin and sialomucin expression in the colon mucosa was evaluated using the histochemical technique of high iron diamine-alcian blue (HID-AB). The tissue expression was quantified for each animal, in the segments with and without fecal stream, at a location where there were four complete contiguous crypts in two random fields, with the aid of the computer-assisted image analysis software. The final value was taken to be the mean reading from the two fields selected, in the segments with and without fecal stream. To compare the expressions of the two mucin subtypes in the segments with and without fecal stream, the paired Student t test was used. To analyze variance according to duration of exclusion, ANOVA with the Newman-Keuls post-test was used, setting the significance level at 5% (p<0.05). RESULTS: There were significant reductions in tissue sulfomucin and sialomucin content in the colon without fecal stream, independent of the duration of exclusion considered. There was increased tissue sulfomucin content and decreased tissue sialomucin in the segments without fecal stream, with increasing duration of exclusion. CONCLUSIONS: Diversion of the fecal transit decreased the tissue sulfomucin and sialomucin content in the segments without fecal stream. Notwithstanding the reduction in the levels of both subtypes of acid mucin in the segments without fecal stream, there was increased tissue sulfomucin content and decreased tissue sialomucin with increasing duration of intestinal diversion.

Purpose:To evaluate histopathological alterations of the colon wall in segments with and without intestinal transit, by computer-assisted imaging, and to correlate these with the length of time diversion. Methods: Thirty male Wistar rats were subjected to intestinal transit diversion by a proximal colostomy and distal mucosa fistula. The animals were divided into three experimental groups according to how long after the initial surgical procedure they were sacrificed: six, twelve and eighteen weeks. Colon segments with and without transit were subjected to histopathological study. The variables colon crypt length, mucosal ulceration, muscle layer thickness of the muscularis mucosa, submucosa and muscularis propria, vascular congestion, number of caliciform cells, inflammatory grade and degree of inflammation, comparing the two colon segments in the different experimental groups were studied. Intestinal crypt length, muscle layer thickness of the mucosa, submucosa and muscularis propria and caliciform cells were measured by computer-assisted imaging method. Mean equality, variance analysis and correlation tests were used in the statistical analysis, and the significance level was set at 5%. Results:Comparison between segments with and without transit showed that the latter presented reduced length of colon crypts and increased muscle layer thickness of the muscularis mucosa, submucosa and muscularis propria. There were greater quantities of ulceration of the mucosal and greater degree of inflammation with increasing time without transit. Mucosal ulceration, submucosal vascular congestion, increased thickness of the submucosal and muscularis propria layers, presence of caliciform cells, inflammatory infiltrate and inflammatory grade correlated significantly with the length of time without transit. Conclusions: Histological alterations occurred in all layers of the colon wall, in the segments without intestinal transit. Ulcerations in the intestinal mucosa, increased number of caliciform cells, greater vascular congestion of the submucosal layer and inflammatory reaction were related to increasing length of time without transit. Key words: Colon. Colitis. Colostomy. Image Processing, Computer-Assisted. Rats. RESUMOObjetivo: Avaliar por método de imagem assistida por computador as alterações histopatológicas da parede cólica em segmentos providos e desprovidos de trânsito intestinal e relacioná-las ao tempo de exclusão. Métodos: Trinta ratos Wistar machos foram submetidos à derivação do trânsito no cólon esquerdo por meio de colostomia proximal e fístula mucosa distal. Os animais foram divididos em três grupos experimentais segundo o sacrifício ter sido realizado seis, doze e dezoito semanas após o procedimento cirúrgico inicial. Segmentos dos cólons providos e desprovidos de trânsito foram submetidos a estudo histopatológico. Foram analisadas as variáveis: comprimento das criptas cólicas, ulceração na mucosa, espessura das camadas muscular da mucosa, submucosa e muscular própria, congestão vascular, número...

PURPOSE:To measure the content of acidic mucin, sialomucin, and sulfomucins in the colonic mucosa without fecal stream submit to intervention with sucralfate (SCF). METHODS:Thirty-six rats were submitted to a right 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, SCF at 1.0 g/kg/day or 2.0 g/kg/day. Colitis was diagnosed by histological analysis. Acid mucins were determined with the Alcian-Blue and sulfomucin and sialomucin by high iron diamine-alcian blue (HID-AB) techniques. The mucins were quantified by computer-assisted image analysis. Mann-Whitney and ANOVA tests were used to analyze the results establishing the level of significance of 5% for both (p<0.05).RESULTS: SCF enemas decreased the inflammation score and was related to the concentration used and time of the intervention. SCF at both concentrations increased the content of acid mucin, which was related to the concentration used and to the improvement in the inflammatory score. There was an increase in the content of sulfomucins and sialomucins in SCF groups. SCF increased sulfomucins from 2 weeks of intervention, which was not related to the dose or time of application. The increase in sialomucin content was related to the time and dose used in the intervention. CONCLUSION:Sucralfate increased the content of acidic mucins, primarily at the expense of sialomucin, which was affected by the dose and time of intervention.

Diversion colitis (DC) is an inflammatory disease that develops in segments with fecal diversion. Sucralfate (SCF) complex, which consists of sucrose octasulfate and polyaluminum hydroxide, has been demonstrated to be effective in the treatment of different forms of colitis. However, until now, the effects of SCF have not been evaluated in DC. Objective to evaluate whether the use of enemas containing SFC improves histological findings in experimental DC. Methods Thirty-six rats underwent right colon bypass procedure through the creation of a proximal colostomy and a distal mucous fistula. The animals were divided into two groups according to the euthanization procedure to be performed two to four weeks after surgery. Each experimental group was divided into three subgroups of six animals, which were submitted to daily application of enemas containing saline solution 0.9% or SCF at concentrations of 1.0 g/kg/day or 2.0 g/kg/day, respectively. The diagnosis of DC in segments with fecal diversion was established by histopathological study considering the following variables epithelial loss, formation of crypt abscesses, the population of goblet cells, inflammatory infiltrate and presence of fibrosis. For statistical analysis, the nonparametric Mann-Whitney and Kruskal-Wallis tests were used, with a significance level of 5% (p <0.05). Results It was observed that the daily application of SCF enemas decreased epithelial loss, formation of colon crypt abscesses, inflammatory infiltrate and tissue fibrosis (p <0.05), unrelated to time of intervention. The intervention with SCF preserves the goblet cell population. The effects of the substance on the preservation of colonic epithelium; the decrease in the inflammatory process and subsequent abscess formation in the colon crypts are associated with the concentration used, whereas tissue fibrosis decrease is associated with the concentration and time of intervention. Conclusion Preventive application of SCF enemas reduces the inflammatory process in the colon with fecal diversion

Diversion of the fecal stream decreases the expression of E-cadherin of the colon epithelium.

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