Intraluminal oxygen can keep small bowel mucosa intact in a segmental ischemia model.

Intestinal preservation for transplantation is accompanied by hypoperfusion with long periods of ischemia with total blood cessation and absolute withdrawal of oxygen leading to structural damage. The application of intraluminal oxygen has been successfully tested in small-animal series during storage and transport of the organ but have been so far clinically unrelatable. In this study, we tested whether a simple and clinically approachable method of intraluminal oxygen application could prevent ischemic damage in a large animal model, during warm ischemia time. We utilised a local no-flow ischemia model of the small intestine in pigs. A low-flow and high-pressure intraluminal oxygen deliverance system was applied in 6 pigs and 6 pigs served as a control group. Mucosal histopathology, hypoxia and barrier markers were evaluated after two hours of no-flow conditions, in both treatment and sham groups, and in healthy tissue. Macro- and microscopically, the luminal oxygen delivered treatment group showed preserved small bowel's appearance, viability, and mucosal integrity. A gradual deterioration of histopathology and barrier markers and increase in hypoxia-inducible factor 1-α expression towards the sites most distant from the oxygen application was observed. Intraluminal low-flow, high oxygen delivery can preserve the intestinal mucosa during total ischemia of the small intestine. This finding can be incorporated in methods to overcome small bowel ischemia and improve intestinal preservation for transplantation.

Clip Ovesco® como tratamiento de rescate en lesión de Dieulafoy duodenal con sangrado activo / Ovesco clip as a rescue treatment of duodenal Dieulafoy lesion with active bleeding

Las lesiones de Dieulafoy se definen como una anomalía vascular que producen un sangrado en la mucosa proveniente de una arteria submucosa anormalmente larga y tortuosa que se ubican principalmente en estómago (80%), con poca frecuencia a nivel duodenal y constituyen el 6% de los sangrados gastrointestinales no asociados a varices y del 1% al 2% de todos los sangrados gastrointestinales. Reportamos el caso de un paciente masculino de 60 años que ingresó por hematemesis, melena y signos de hipovolemia con hemoglobina de 9 g/dl, que luego de realizar su compensación hemodinámica se le realizó una endoscopía alta que evidenció una lesión de Dieulafoy con sangrado activo severo en la segunda porción duodenal realizándosele inyección con adrenalina al 1:10 000 sobre los bordes de la lesión, pero al no lograrse una hemostasia adecuada se le tuvo que realizar la colocación de un clip ovesco con hemostasia efectiva que se corroboró 24 horas después, a través de una segunda endoscopía para poder egresar al paciente sin complicaciones, ni resangrado.

Dieulafoy's lesions are vascular anomalies that produce gastrointestinal bleeding of the mucosa from an abnormally long and tortuous submucosal artery. It is found predominately in the stomach (80%) and less frequently in the duodenum. They constitute the 6% of all non-variceal bleeding and the 1 to 2% of all gastrointestinal bleeding source. We report a case of a 60-year-old man with hematemesis, melena and signs of hypovolemic shock with a hemoglobin level of 9 g/dL. After adequate fluid resuscitation, an upper endoscopy showed an actively bleeding Dieulafoy lesion in the second portion of the duodenum. After epinephrine injection over lesion borders, an adequate hemostasis was not achieved. An over-the-scope clip was placed. Follow-up endoscopy 24 hours later showed an effective hemostasis and the patient was discharged without complications or re-bleeding.

Vascular endothelial growth factor, endostatin levels and clinical features among patients with ulcerative colitis and irritable bowel syndrome and among healthy controls: a cross-sectional analytical study

ABSTRACT BACKGROUND: Increased angiogenetic activity in inflammatory bowel disease (IBD) has been shown in previous studies. The aim of this study was to evaluate the relationship of serum vascular endothelial growth factor (VEGF) and endostatin levels with clinical features and mucosal expression in patients with ulcerative colitis (UC). DESIGN AND SETTING: Cross-sectional analytical study conducted in a tertiary-level public hospital. METHODS: Serum VEGF and endostatin levels were determined in 82 individuals: 39 with UC, 28 with irritable bowel syndrome (IBS) and 15 healthy controls (HCs), using enzyme-linked immunosorbent assays (ELISA). VEGF and endostatin expressions were studied using immunohistochemistry (IHC). RESULTS: Mean serum VEGF and endostatin levels were significantly higher in patients with UC than in patients with IBS and in HCs (511.9 ± 377.5 pg/ml, 305.0 ± 121.42 pg/ml and 36.1 ± 40.6 pg/ml; P = 0.001 for VEGF; and 155.50 ± 59.8 ng/ml, 116.9 ± 23.8 ng/ml and 102.2 ± 22.4 ng/ml; P < 0.001 for endostatin, respectively). There was a positive correlation between serum VEGF and endostatin levels (r = 0.422; P < 0.01). Mean H-scores for VEGF expression were higher in the active UC group than in the inactive UC and IBS groups, in the stroma, endothelium and epithelium. Mean H-scores for endostatin expression were higher in the active UC group than in the inactive UC and IBS groups, in the stroma and endothelium. There was no endostatin expression in the epithelium. CONCLUSION: Increased endostatin appears to be a defensive reaction to increased VEGF in patients with UC.

Neonatal necrotizing enterocolitis rat model attenuated by a remote ischemic preconditioning in the pregnant

Abstract Purpose: To evaluate the effect of remote ischemic preconditioning (r-IPC) administered to pregnant rats, in the ileum of newborn rats subjected to hypoxia and reoxygenation. Methods: We used three pregnant rats and their newborn rats distributed in three groups: 1) Control (C) - Newborn rats born from a pregnant rat which did not undergo any intervention; 2) Hypoxia-Reoxygenation (H/R) - Newborn rats born from a pregnant rat which did not undergo any intervention, and were subjected to hypoxia-reoxygenation; 3) Remote Ischemic Preconditioning (r-IPC) - newborn rats born from a pregnant rat which was subjected to remote ischemic preconditioning twenty-four hours before giving birth and the newborn rats were subjected to hypoxia-reoxygenation. Segments of ileum were prepared for histological analysis by HE and immunohistochemistry by the Ki67 to evaluate cell proliferation, crypt depth and villus height and evaluation of apoptosis by cleaved caspase-3. Results: The intensity of the lesions was lower in the r-IPC than in the H/R group, showing significant difference (p<0.01). The r-IPC group showed a higher proliferative activity compared to the H/R group (p<0.01), with deeper crypts (r-IPC > H/R - p < 0.05), and higher villi, showing significant difference (r-IPC > H/R - (p <0.01). The occurrence of apoptosis in the H/R group was lower in comparison to groups C and r-IPC, with significant difference (H/R < r-IPC; p<0.05). Conclusion: The remote ischemic preconditioning applied to the pregnant rat protected the ileum of newborn rats subjected to hypoxia and reoxygenation, with decreased intensity of the lesions in the ileum mucosa and preservation of proliferative activity, keeping the villus height and crypt depth similar to group C.

Reduction of venous pressure during the resection of liver metastases compromises enteric blood flow: IGFBP-1 as a novel biomarker of intestinal barrier injury

OBJECTIVES: Disruption of the intestinal barrier and bacterial translocation commonly occur when intestinal blood flow is compromised. The aim of this study was to determine whether liver resection induces intestinal damage. METHODS: We investigated intestinal fatty-acid binding protein and insulin-like growth factor binding protein levels in the plasma of patients who underwent liver resection. RESULTS: We show that liver resection is associated with significant intestinal barrier injury, even if the Pringle maneuver is not performed. CONCLUSION: We propose the use of insulin-like growth factor binding protein-1 as a novel biomarker of intestinal damage in such situations.

Ischemic postconditioning assessment in the liver of rats undergoing mesenteric ischemia and reperfusion

Abstract Introduction: Ischemic postconditioning is a method that shows evidence of efficacy in minimizing reperfusion injury; however, its effectiveness in preventing injuries in distant organs is still unknown, especially in those who have undergone mesenteric ischemia and reperfusion. Objective: To evaluate the effect of ischemic postconditioning in preventing reperfusion injury in the liver of rats submitted to mesenteric ischemia and reperfusion, comparing two different methods of ischemic postconditioning. Methods: 30 Wistar male rats were used, distributed into three groups: Group A: Ten rats submitted to intestinal ischemia for 30 minutes followed by reperfusion for 60 minutes; Group B: Ten rats subjected to ischemia and reperfusion; after ischemia, two cycles of reperfusion (two minutes each) interleaved with two cycles of ischemia (two minutes each); and Group C: Ten rats subjected to ischemia and reperfusion; after ischemia, four cycles of reperfusion (30 seconds each) interspersed with four cycles of ischemia (30 seconds each). After the experiment, the left lobe of the liver was resected for subsequent histological analysis, using the following classification: grade 1 - centrilobular congestion; grade 2 - centrilobular congestion with some degeneration of hepatocytes in one or two central veins; and grade 3 - multifocal centrilobular congestion and degeneration of portal hepatocytes. Results: The mean degree of liver damage found was 1.8 in group A, 1.7 in group B and 1.3 in group C. There was no statistically significant difference between the groups. Conclusion: Ischemic postconditioning was unable to minimize reperfusion injury in rats undergoing mesenteric ischemia and reperfusion.

Importance of duration and number of ischemic postconditioning cycles in preventing reperfusion mesenteric injuries. Experimental study in rats

PURPOSE:To evaluate the effect of ischemic postconditioning(IPC) on intestinal mucosa of rats subjected to ischemia and reperfusion process comparing two cycles of reperfusion and ischemia lasting two minutes each and four cycles of reperfusion and ischemia lasting 30 seconds eachMETHODS: Thirty Wistar rats were distributed into three groups: group A (10 rats), ischemia (30 minutes) and reperfusion (60 minutes); group B (10 rats), ischemia and reperfusion plus IPC by two lasting two minutes each; and Group C (10 rats), ischemia and reperfusion plus IPC by four cycles lasting 30 seconds each. Finally, a segment of small intestine was resected for histological analysis. We analysed the results according to Chiu et al. classification and proceeded to the statistical treatment by Kruskal-Wallis test (p<0.05).RESULTS: The mean degree of tissue injury according to Chiu et al. classification were: Group A, 2.77; in group B, 1.4; and group C, 1.4. B X C (p<0.05).CONCLUSIONS: Ischemic postconditioning was able to minimize reperfusion injury of rats undergone mesenteric ischemia and reperfusion process. There was no difference in the effectiveness of the method comparing two cycles of two minutes with four cycles of 30 seconds by H&E histological evaluation of the ileum after 60-minute reperfusion.

Pentoxifylline and prostaglandin E1 action on ischemia and reperfusion of small intestine tissue in rats. An immunohistochemical study

PURPOSE: To investigate the action of pentoxifylline (PTX) and prostaglandin E1 (PGE1) on ischemia and reperfusion of small intestine tissue in rats, using immunohistochemical analysis. METHODS: Thirty-five Wistar rats were distributed as follows: group A (n=10): subjected to intestinal ischemia and reperfusion for 60 min, with no drugs; group B (n=10): PTX given during tissue ischemia and reperfusion; group C (n=10): PGE1 given during tissue ischemia and reperfusion; group D (n=5): sham. A segment of the small intestine was excised from each euthanized animal and subjected to immunohistochemical examination. RESULTS: Mean number of cells expressing anti-FAS ligand in the crypts was highest in Group A (78.9 ± 17.3), followed by groups B (16.7 ± 2.8), C (11.3 ± 1.8), and D (2.5 ± 0.9), with very significant differences between groups (p<0.0001). CONCLUSIONS: The use of pentoxifylline or prostaglandin E1 proved beneficial during tissue reperfusion. The immunohistochemical results demonstrated a decrease in apoptotic cells, while protecting other intestinal epithelium cells against death after reperfusion, allowing these cells to renew the epithelial tissue. .

Effects of maternal ischemic preconditioning in the colon of newborn rats submitted to hypoxia-reoxygenation insult

PURPOSE: To evaluate the effects of maternal remote ischemic preconditioning (IPCr) in the colonic mucosa of newborn rats subjected to hypoxia and reoxygenation. METHODS: Newborn Wistar rats were divided into three groups. Control Group (CG), Hypoxia and Reoxygenation Group (HRG) and Remote Ischemic Preconditioning Group (IPCrG). Hypoxia and reoxygenation was performed 2x per day, with an interval of 6 hours, on the 1st, 2nd and 3rd days of life, with 10 minutes of CO2 at 100%, followed by 10 minutes O2 at 100%(HRG/IPCrG). The maternal IPCr was performed 24 hours before delivery by applying a rubber band tourniquet to the left hind limb (IPCrG). Segments of the colon underwent histological (HE) and immunohistochemical analysis for caspase-3 and COX - 2. RESULTS: The histological findings showed no intestinal mucosal damage in the CG group and severe lesions in HRG that was attenuated in the IPCrG (p<0.05). The expression of the apoptotic cells was lower in the HRG group than in the CG and IPCrG. The COX-2 expression was intense in HRG and attenuated in the IPCrG (p<0.05). CONCLUSIONS: Maternal IPCr protected the colonic mucosa of newborn rats subjected to hypoxia and reoxygenation, reducing the morphological alterations and inflammatory response. It ameliorates the occurrence of apoptosis, keeping the physiological process of renewal and regeneration in the epithelial lining of the colonic mucosa. .

Very short cycles of postconditioning have no protective effect against reperfusion injury. Experimental study in rats / Ciclos muito curtos de pós-condicionamento não protegem contra lesão de reperfusão. Estudo experimental em ratos

Introduction: Ischemic postconditioning has been recognized as effective in the prevention of reperfusion injury in situations of ischemia and reperfusion in various organs and tissues. However, it remains unclear what would be the best way to accomplish it, since studies show great variation in the method of their application. Objective: To assess the protective effect of ischemic postconditioning on ischemia and reperfusion in rats undergoing five alternating cycles of reperfusion and ischemia of 30 seconds each one. Methods: We studied 25 Wistar rats distributed in three groups: group A (10 rats), which underwent mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B (10 rats), undergoing ischemia (30 minutes) and reperfusion (60 minutes), intercalated by postconditioning (5 alternating cycles of reperfusion and ischemia of 30 seconds each one); and group C - SHAM (5 rats), undergoing only laparotomy and manipulation of mesenteric artery. All animals underwent resection of an ileum segment for histological analysis. Results: The mean lesions degree according to Chiu et al. were: group A, 2.77, group B, 2.67 and group C, 0.12. There was no difference between groups A and B (P>0.05). Conclusion: Ischemic postconditioning was not able to minimize or prevent the intestinal tissue injury in rats undergoing ischemia and reperfusion process when used five cycles lasting 30 seconds each one. .

Introdução: O pós-condicionamento isquêmico tem sido reconhecido como eficaz na prevenção das lesões de reperfusão em situações de isquemia e reperfusão em vários órgãos e tecidos. Entretanto, não está ainda claro qual seria a melhor maneira de realizá-lo, já que as publicações mostram grande variação de método no seu emprego. Objetivo: Avaliar o efeito protetor do pós-condicionamento isquêmico na isquemia e reperfusão intestinal em ratos, através de cinco ciclos alternados de 30 segundos de isquemia e 30 segundos de reperfusão. Métodos: Foram estudados 25 ratos Wistar, distribuídos em três grupos: grupo A (10 ratos), em que se realizou isquemia (30 minutos) e reperfusão (60 minutos) mesentérica; grupo B (10 ratos), isquemia e reperfusão, seguidos de pós-condicionamento isquêmico com 5 ciclos alternados de reperfusão e reoclusão, de 30 segundos cada; e grupo C (5 ratos), controle (SHAM). Ao final, ressecou-se um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de Chiu et al. e procedeu-se ao tratamento estatístico. Resultados: As médias dos graus de lesão tecidual segundo a classificação de Chiu et al. foram: no grupo A, 2,77; no grupo B, 2,67; e no grupo C, 0,12. A diferença entre o resultado do grupo A com o resultado do grupo B não teve significância estatística (P>0,05). Conclusão: O pós-condicionamento isquêmico não foi capaz de minimizar ou prevenir a lesão tecidual intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica quando utilizados cinco ciclos com duração de 30 segundos cada. .

Idosos vítimas de trauma: doenças preexistentes, medicamentos em uso no domicílio e índices de trauma / Elderly victims of trauma: preexisting conditions, medications taken at home and indexes of trauma / Ancianos víctimas de trauma: condiciones preexistentes, medicamentos tomados en el hogar e índices de trauma

Objetivou-se identificar o perfil sociodemográfico de idosos vítimas de trauma, caracterizar doenças preexistentes e medicamentos utilizados no domicílio; calcular índices de trauma e desfecho clínico. Estudo retrospectivo e exploratório, com a análise de dados secundários de um banco de dados de um hospital geral terciário, entre 2008 e 2010. Foram estudados 131 idosos, média de idade 69,9 anos, 73,3% homens, 55,1% casados, 54,7% aposentados; 65,6% possuíam doenças preexistentes e 48,9% usavam medicamentos no domicílio. Houve representatividade de quedas (31,3%), seguidas por atropelamento (28,2%), com cabeça/pescoço sendo a região mais acometida (59,5%). Prevaleceu o trauma moderado (44,3%), com condições de sobrevida após o evento (80,2%). Houve associação entre mecanismo do trauma e doença preexistente (p=0,01) e entre mecanismo do trauma e sexo (p=0,03). O conhecimento das variáveis envolvidas com idosos vítimas de trauma possibilita aos profissionais de saúde o planejamento de medidas preventivas, visando aprimorar sua assistência.

The objective was to identify the sociodemographic profile of the elderly victims of trauma, to characterize preexisting conditions and medications taken at home, and to calculate indices of trauma and clinical outcomes. This is a retrospective and exploratory analysis from a database of a general hospital between 2008 and 2010. There were studied 131 elderly, mean age 69.9 years, 73.3% male, 55.1% married, 54.7% retired, 65.6% had preexisting conditions and 48.9% used drugs at home. There was a representative number of falls (31.3%), followed by running over (28.2%), with the head/neck region being the most affected (59.5%). Moderate trauma prevailed (44.3%), with conditions of survival after the event (80.2%). There was an association between mechanism of trauma and preexisting disease (p=0.01) and between mechanism of trauma and sex (p=0.03). The knowledge of the variables involved with the elderly victims of trauma enables healthcare professionals to plan preventive measures aimed at improving the assistance. Key words: Aged; Wounds and Injuries; Disease; Drug Utilization.

Se objetivó identificar el perfil sociodemográfico de ancianos víctimas de trauma, caracterizar condiciones preexistentes y medicamentos tomados en casa, y calcular índices de trauma y evolución clínica. Se realizó un análisis retrospectivo y exploratorio de una base de datos de un hospital general terciario entre 2008 y 2010. Se estudiaron 131 ancianos, media of 69,9 años, 73,3% hombres, 55,1% casados, 54,7% jubilados, 65,6% tienen condiciones preexistentes y 48,9% estaban tomando medicación en casa. Hubo representación de las caídas (31,3%), seguido de atropello (28,2%). La región cabeza/cuello fue el más afectado (59,5%). Prevaleció trauma moderado (44,3%), con condiciones de supervivencia después del evento (80,2%). Se observó una asociación entre mecanismo de lo trauma y enfermedad previa (p=0,01) y entre mecanismo de lo trauma y sexo (p=0,03). El conocimiento de las variables que intervienen con ancianos víctimas de trauma permite a los profesionales de la salud planificar medidas preventivas para mejorar su asistencia.

Hystopathological study of the intestinal epithelium submitted to different times of programmed ischemia and twenty four hours reperfusion

PURPOSE: To investigate the changes in the intestinal epithelium of rats, when submitted to the ischemia of varied time and scheduled reperfusion. METHODS: For this purpose, the following groups were established six groups: control, 10, 20, 30, 40, 60 minutes of ischemia and reperfusion time (24 hours). Their intestines being resected for histopathological analysis: the length and width of the villus, and mitotic index. The nonparametric test Kruskal-Wallis and multiple comparisons test were applied. RESULTS: The qualitatively the intestinal epithelium is regenerated when submitted to different ischemia, and 24 hours reperfusion time. It was observed that morphometry analyzing taking villus length and width and mitotic index as parameter, meaningful alterations were detected. CONCLUSION: The epithelium is regenerated, when subjected to different time planned of ischemia and reperfusion. It was observed: decrease the length and increase the width of the villi, when compared Group VI with I and II, and Group VI with I; increased mitotic index when compared Groups III with I. Every analysis was statistically significant.

Ischemia and reperfusion of rat small intestine using pentoxyfilline and prostaglandin E1

PURPOSE: To investigate the small intestinal tissue alterations in rats submitted to ischemia and tissue reperfusion using pentoxyfilline or prostaglandin E1. METHODS: Thirty five Wistar rats were used, distributed into group control (A) n=10 were submitted to intestinal ischemia and reperfusion during 60 minutes and no one drug have been utilized. In the group pentoxyfilline (B) n=10 have been utilized during tissue ischemia and reperfusion as well as prostaglandin E1 (C) n=10, but separately. In the group sham (D) n=5, the animals were submitted to surgical. After euthanasia of the animals, a segment of the small intestine was cut, stained by hematoxilin-eosin and histological analysis according to Chiu criteria. RESULTS: Histological results showed that using pentoxyflline or prostaglandin E1 the results during tissue reperfusion were better, since the levels of criteria from Chiu that predominated were level 2 and 3, indicating less tissue damage in comparison to the control group (group A) that showed levels 4 and 5, what means more severe histological tissue alterations. CONCLUSION: Use of pentoxyfilline or prostaglandin E1 promoted a beneficial effect during intestinal reperfusion, demonstrated by less severe histological lesions in the small intestine mucosa of rats submitted to ischemia and tissue reperfusion when helped by the drugs.

Local and remote ischemic preconditioning protect against intestinal ischemic/reperfusion injury after supraceliac aortic clamping

OBJECTIVES: This study tests the hypothesis that local or remote ischemic preconditioning may protect the intestinal mucosa against ischemia and reperfusion injuries resulting from temporary supraceliac aortic clamping. METHODS: Twenty-eight Wistar rats were divided into four groups: the sham surgery group, the supraceliac aortic occlusion group, the local ischemic preconditioning prior to supraceliac aortic occlusion group, and the remote ischemic preconditioning prior to supraceliac aortic occlusion group. Tissue samples from the small bowel were used for quantitative morphometric analysis of mucosal injury, and blood samples were collected for laboratory analyses. RESULTS: Supraceliac aortic occlusion decreased intestinal mucosal length by reducing villous height and elevated serum lactic dehydrogenase and lactate levels. Both local and remote ischemic preconditioning mitigated these histopathological and laboratory changes. CONCLUSIONS: Both local and remote ischemic preconditioning protect intestinal mucosa against ischemia and reperfusion injury following supraceliac aortic clamping. .

A morphometric study of the intestinal mucosa of rats submitted to omentoenteropexy / Estudo morfométrico da mucosa intestinal de ratos submetidos a omentoenteropexia

CONTEXT: The omentoenteropexy technique was developed as an alternative method for intestinal neovascularization, due to the angiogenic properties of factors from the omentum. OBJECTIVES: This study investigated changes in intestinal villi heights and crypts depths due to surgical techniques: seromiotomy with and without omentoenteropexy. METHOD: Thirty rats were operated on, after being divided into three groups, namely GI, GII and GIII with 10 rats each. In the GI rats were submitted to omentoenteropexy; rats in GII were submitted only to a seromiotomy, and in the GIII only laparotomy. Sixty days after the first surgery, the animals were sacrificed and a segment of intestine was removed for histology using Masson's trichrome technique and morphometric study of intestinal mucosa. RESULTS: The histological findings showed that seromiotomy with or without omentoenteropexy increased the length of intestinal villi when compared with GIII (only laparotomy) (analysis of variance: P = 0.0068; GI 38.88 ± 4.17; GII 39.41± 6.33; GIII 31.85 ± 5.56; GI = GII P>0.05; GII>GIII P<0.05; GI>GIII P<0.001). CONCLUSION: No differences were demonstrated in relation to crypt depths between the groups (P = 0.60). Ongoing studies are being set forth by our group to add more data on the role of omentopexy as a tool to promote neovascularization and intestinal mucosal growth.

CONTEXTO: a omentoenteropexia foi desenvolvida como técnica alternativa para a neovascularização intestinal, devido às propriedades angiogênicas de fatores provenientes do omento. OBJETIVO: Investigar as alterações nas alturas vilositárias e profundidades de cripta na mucosa intestinal de ratos submetidos a seromiotomia com e sem omentopexia. MÉTODOS: Trinta ratos foram operados após serem divididos em três grupos com 10 animais cada um. No grupo I (GI) os ratos foram submetidos seromiotomia seguida por omentoenteropexia; no grupo II (GII) foi realizada apenas a seromiotomia, e no grupo III (GIII) apenas a laparotomia. após 60 dias, os animais foram sacrificados e seus intestinos examinados histologicamente, corados pelo tricrômio de Masson, sendo realizado também estudo morfométrico da mucosa intestinal. RESULTADOS: O estudo mostrou que a altura vilositária é maior nos grupos submetidos a seromiotomia, com ou sem omentopexia, do que no grupo em que se realizou laparotomia apenas, porém entre os dois primeiros grupos não houve diferença significante (análise de variância: P = 0,0068; GI 38,88 ± 4,17; GII 39,41 ± 6,33; GIII 31,85 ± 5,56; GI = GII P>0,05; GII>GIII P<0,05; GI>GIII P<0,001). CONCLUSÕES: Não foram demonstradas diferenças quanto às profundidades de criptas entre os grupos (P = 0,60). Novos estudos estão sendo realizados por este grupo para acrescentar mais dados sobre o papel da omentopexia como forma de promover neovascularização e crescimento da mucosa intestinal.

Ischemia-reperfusion histopathology alterations of the rabbit intestinal wall with and without ischemic preconditioning / Alterações histopatológicas da parede intestinal de coelhos na isquemia-reperfusão com e sem precondicionamento isquêmico

PURPOSE: To evaluate the histopathology alterations of the intestinal mucosa of rabbits submitted to mesenteric artery ischemia and reperfusion with and without ischemic preconditioning. METHODS: Two groups of ten male New Zealand white rabbits body (weight 2.2-3.0, average 2.5 kg). For mesenteric ischemia induction in all animals the small bowel and mesentery were cut 30cm and 60cm far from the gastroduodenal pyloric transition before the proximal mesenteric artery occlusion. In the Group 1 animals, the proximal mesenteric artery was occluded for 45 min with an atraumatic vascular clamp, followed by reperfusion for 30 min. In the Group 2 the 45 min ischemic phase was preceded by three cycles of ischemia (2 minutes each) alternated with three cycles of reperfusion (2 minutes each). For istopathology study small bowel biopsies were obtained before ischemia (control), after 45 min of mesenteric ischemia and at 30 min. of mesenteric artery reperfusion. RESULTS: In the Group I animals, the followings histopathology grade results were observed: t1, mean 2,8; t2, mean 3,3. Using the Kruskal-Wallis non-parameter test, differences between t0 and t1 and t0 and t2 were significants (p<0.05), but not significant between t1 and t2 (p>0.05). In the Group 2 animals histopathology grade results were: t1 mean 2,6 and t2, mean 2,1. Differences between t0 and t1, t0 and t2 were significant (p<0.05). It was not observed differences (p>0.05) between results of t1 in both groups but histopathology injury observed in Group 1 t2 biopsies were higher (p<0.05) than observed in the same period (t2) of Group 2 animals. CONCLUSION: Microscopic examination of the biopsies revealed significant evidence of preconditioning protection against small bowel wall ischemia-reperfusion injury.

OBJETIVO: Avaliar as alterações histopatológicas da mucosa intestinal de coelhos submetidos a isquemia-reperfusão com e sem precondicionamento isquêmicol. MÉTODOS: Foram estudados dois grupos de dez coelhos Nova Zelândia machos com pesos variáveis entre 2,2 e 3,0 kg (média de 2,5 kg) de peso corpóreo. Para indução da isquemia, em todos os animais, o intestino delgado e o mesentério foram seccionados 30 cm e 60 cm após a transição pilórica gastroduodenal, antes da oclusão da artéria mesentérica cranial. Nos animais do Grupo 1, a artéria mesentérica proximal foi ocluida por pinçamento atraumático durante 45 min., seguido de reperfusão por 30 min. No Grupo 2, foi realizado precondicionamento por três ciclos de 2 min. de oclusão mesentérica intercalados com três ciclos de 2 min. de reperfusão, seguido de oclusão mantida por 45 min e reperfusão de 30min. como no Grupo I. Para estudo histopatológico, foram obtidas biópsias da parede intestinal antes da isquemia (t0-controle), após 45 min. de isquemia (t1) e após 30 min. de reperfusão (t2). RESULTADOS: No Grupo I foram observados os seguintes graus de lesões: t1, média de 2,8 e t2, média 3,3, Foram significantes as diferenças entre t0 e t1 e t0 e t2, mas não foram significantes as variações entre t1 e t2 (p>0,05). No Grupo 2, obteve-se em t1,média de 2,6 e t2, média 2,1. Foram significantes (p<0,05) as diferenças entre t0 e t1, t0 e t2 e entre t1 e t2. . Não ocorreu diferença significante (p>0,05) entre os resultados de t1 nos dois Grupos, mas foram significantes (p<0,05) as diferenças entre os resultados histopatológicos das biopsias de t2 dos Grupos 1 e 2. CONCLUSÃO: O precondicionamento isquêmico reduziu significantemente a degeneração histopatológica determinada pela reperfusão pós-isquêmica da parede intestinal.

Avaliação do pós-condicionamento isquêmico no tratamento da isquemia mesentérica: estudo experimental em ratos / Evaluation of ischemic postconditioning effect on mesenteric ischemia treatment: experimental study in rats

OBJETIVO: Avaliar o efeito do pré e pós-condicionamento isquêmico sobre a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica. MÉTODOS: Foram estudados 30 ratos Wistar, distribuídos em três grupos: grupo A, em que se realizou isquemia (30 minutos) e reperfusão (60 minutos) mesentérica; grupo B, isquemia e reperfusão mesentérica precedidos pelo pré-condicionamento isquêmico por três ciclos de isquemia e reperfusão com duração de dois minutos cada; grupo C, isquemia e reperfusão mesentérica e, precedendo o início da reperfusão, foi realizado o pós-condicionamento isquêmico por três ciclos de reperfusão e isquemia com duração de dois minutos cada. Ao final, ressecou-se um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de Chiu et al. e procedeu-se ao tratamento estatístico. RESULTADOS: As médias dos graus de lesão tecidual segundo a classificação de Chiu et al. foram: no grupo A, 3,5; grupo B, 1,2; grupo C, 1. A diferença entre o resultado do grupo A com os resultados dos grupos B e C foi considerada estatisticamente significativa (P < 0,05). CONCLUSÃO: O pré e pós-condicionamento isquêmico foram capazes de minimizar, com intensidade semelhante, a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica.

OBJECTIVE: To assess the preconditioning and postconditioning effect on intestinal mucosal lesions in rats undergone mesenteric ischemia and reperfusion procedure. METHODS: Thirty Wistar rats were studied and divided into three groups: Group A, 10 rats undergone mesenteric ischemia (30 minutes) and reperfusion (60 minutes); Group B, 10 rats undergone mesenteric ischemia and reperfusion preceded by ischemic preconditioning for three cycles of ischemia and reperfusion for two minutes each; Group C, 10 rats undergone mesenteric ischemia and reperfusion and, preceding the beginning of reperfusion, ischemic postconditioning was performed for three cycles of reperfusion and ischemia for two minutes each. Then, a segment of small intestine was resected for histological analysis. We assessed the results by Chiu et al. score and the statistical analysis was performed. RESULTS: According to Chiu et al. score, the means of lesion degree were: In the group A, 3.5; Group B, 1.2; Group C, 1. The difference between group A with the groups B and C was considered statistically significant (P < 0.05). CONCLUSION: Ischemic pre- and postconditioning were capable of minimizing - in a similar intensity - the tissue injury on the intestinal mucosa of rats undergone mesenteric ischemia and reperfusion process.

Bacterial translocation in an experimental intestinal obstruction model: C-reactive protein reliability? / Translocação bacteriana no modelo experimental de obstrução intestinal: A proteína C-reativa é confiável?

BACKGROUND: Bacterial translocation occurs in preseptic conditions such as intestinal obstruction through unclear mechanism. The C-reactive protein is an acute phase reactant and a marker of ischemia. METHODS: 45 albino male rats were divided into 3 groups each 15 rats. GI control, GII simple intestinal-obstruction and GIII strangulated obstruction. Outcome measures were: (1) Bacteriologic count and typing for intestinal contents, intestinal wall, liver, mesenteric lymph nodes and blood (cardiac and portal) (2) Histopathologic: mucosal injury score, inflammatory cell infiltrate in the wall, MLN, liver, (3) Biochemical: serum CRP, IL-10, mucosal stress pattern (glutathione peroxidase-malonyldialdhyde tissue levels). RESULTS: (1) Intestinal obstruction associates with BT precursors (Bact-overgrowth, mucosal-acidosis, immuno-incomptence), (2) Bacterial translocation (frequency and density) was found higher in strangulated I.O, that was mainly enteric (aerobic and anaerobic) and mostly E.coli, (3) The pathogen commonality supports the gut origin hypothesis but the systemic inflammatory response goes with the cytokine generating one. (4) The CRP median values for GI, II, III were 0.5, 6.9, 8.5 mg/L, for BT +ve 8 mg/L and 0.75 mg/L for BT -ve rats. CONCLUSION: Bacterial translocation occurs bi-directional (systemic-portal) in intestinal obstruction and the resultant inflammatory response pathogenesis is mostly 3 hit model. The CRP is a non selective marker of suspected I.O cases. However, it is a reliable marker of BT, BT density and vascular compromise during I.O.

OBJETIVO: Translocação bacteriana ocorre em condições pré-sépticas como na obstrução intestinal por mecanismo não esclarecido. A proteína C-reativa é um marcador de ischemia em fase aguda. A proposição é investigar os possíveis efeitos da obstrução intestinal no equilíbrio ecológico microbiano. MÉTODOS: 45 ratos machos albinos foram distribuídos em três grupos de 15 ratos. GI controle, GII obstrução intestinal simples e GIII obstrução estrangulada. As medidas adotadas foram: (1) Contagem bacteriológica do conteúdo intestinal, parede intestinal, fígado, linfonodos mesentéricos e sangue (coração e portal) (2) Avaliação histopatológica da lesão da mucosa, infiltrado celular inflamatório da parede, linfonodos mesentéricos, fígado, (3) Avaliação bioquímica. RESULTADOS: (1) Obstrução intestinal está associada a precursora translocação bacteriana (crescimento bacteriano, acidose da mucosa, imuno-incompetência), (2) Translocação bacteriana (freqüência e densidade) foi maior na obstrução intestinal estrangulada, principalmente entérica (aeróbios e anaeróbios), sobretudo E.coli, (3) A ocorrência comum é de origem intestinal. CONCLUSÃO: A translocação bacteriana na obstrução intestinal é bi-direcional (sistêmica e portal) A proteina C-reativa não é um marcador seletivo na suspeita de obstrução intestinal. Contudo é marcador confiável da translocação bacteriana, na densidade e comprometimento durante a obstrução intestinal.

Effect of different periods of hyperbaric oxygen on ischemia-reperfusion injury of rat small bowel

PURPOSE: To determine whether hyperbaric oxygen (HBO) could effectively protect the small intestine mucosa against an ischemic insult, according to different periods of application. METHODS: The gut of 32 male rats was subjected to 60-min ischemia (clamping the mesenteric artery and vein); After they were further reperfused upon clamp opening during 60 min. Animal groups were as follows. GII = placed on HBO during the ischemia period; GIII = placed on HBO during reperfusion; GIV = treated with HBO throughout the ischemia-reperfusion period. Some animals (GI) did not receive HBO treatment at all and served as reference of ischemia-reperfusion injury (IR). HBO was carried out in a cylindrical acrylic chamber (2.0 ATA). Samples of small bowel were prepared for H.E staining for histological evaluations. RESULTS: The histological injury of mucosa was significantly less when HBO was administered during the ischemia period (17.6 ± 0.6) as compared with the IR (21.3 ± 1.8). HBO was not effective when applied during reperfusion (23.1 ± 2.1) or during the ischemia plus reperfusion period (18.7 ± 1.9). The thickness of the mucosa was preserved by HBO in ischemia (327.50 ± 30.23 µm) in comparison with the IR (172.79 ± 5.95 µm). In the periods of reperfusion (162.50 ± 6.05 µm) and ischemia plus reperfusion (296.49 ± 20.01 µm) the mucosa revealed a structural injury. CONCLUSION: Hyperbaric oxygen affects the ischemic insult of small bowel, being the favorable effect obtained when hyperbaric oxygen was administered early in the ischemic period.

OBJETIVO: Determinar se a oxigenação hiperbárica (OHB) protege a mucosa do intestino delgado de ratos após isquemia e reperfusão. MÉTODOS: 32 ratos machos foram submetidos a clampeamento da artéria e da veia mesentéricas superiores durante 60 minutos (isquemia) seguido de 60 minutos de reperfusão. Após estes procedimentos os animais fora separados em quatro grupos, a saber: grupo I (GI) isquemia e reperfusão (IR); grupo II (GII) submetido a OHB concomitante a isquemia, Grupo III (GIII) submetido a OHB durante a reperfusão e, grupo IV (GIV) submetido a OHB durante o período de isquemia e de reperfusão. A OHB foi realizada em câmara acrílica (2.0 ATA). Após anestesia, fragmentos do intestino delgado (íleo) foram fixados e processados para inclusão em parafina sendo os cortes corados pelo HE. As lâminas foram avaliadas quanto a presença de lesões histopatológicas da mucosa e avaliado a espessura da mucosa. RESULTADOS: A lesão histopatológica da mucosa foi significativamente inferior quando a OHB foi administrada na isquemia (12.6 ± 0.6) em comparação com o IR (21.3 ± 1.8). A OHB não foi efetiva quando aplicada durante a reperfusão (23.1 ± 2.1), ou durante a isquemia e reperfusão (18.7 ± 1.9). A espessura da mucosa foi preservada pela OHB na isquemia (327,50 ± 30.23 µm) em comparação com o IR (172.79 ± 5.95 µm). Nos períodos de reperfusão (162.50 ± 6.05 µm) e a isquemia (296.49 ± 20.01 µm) a mucosa apresentou lesão estrutural. CONCLUSÃO: A oxigenação hiperbárica protege a mucosa intestinal quando realizada durante o período de isquemia.

The ischemic preconditioning and postconditioning effect on the intestinal mucosa of rats undergoing mesenteric ischemia/reperfusion procedure

PURPOSE: To evaluate the effect of the ischemic preconditioning and the ischemic postconditioning over the tissue injury in the intestinal mucosa of rats undergoing the procedure of mesenteric ischemia and reperfusion. METHODS: Thirty Wistar rats were studied, divided in three groups: group A, undergoing mesenteric ischemia (30 minutes) and reperfusion (60 minutes); group B, mesenteric ischemia and reperfusion preceded by ischemic preconditioning; group C, mesenteric ischemia and reperfusion and, before the beginning of reperfusion, the ischemic postconditioning was performed. At the end, a segment of the small intestine was dissected for histological analysis. The results were evaluated using the CHIU et al.6 classification followed by the statistic treatment. RESULTS: The mean values of the tissue injury levels were: group A, 3.5; group B, 1.2; and group C, 1. The difference between the result of group A with the results of groups B and C was considered statistically significant (p < 0,05). CONCLUSION: The ischemic preconditioning and postconditioning are able to minimize the tissue injury in the intestines of rats that underwent the procedure of mesenteric ischemia and reperfusion.

OBJETIVO: Avaliar o efeito do pré e pós-condicionamento isquêmico sobre a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica. MÉTODOS: Foram estudados 30 ratos Wistar, distribuídos em três grupos: grupo A, em que se realizou isquemia (30 minutos) e reperfusão (60 minutos) mesentérica; grupo B, isquemia e reperfusão mesentérica precedidos pelo pré-condicionamento isquêmico; grupo C, isquemia e reperfusão mesentérica e, precedendo o início da reperfusão, foi realizado o pós-condicionamento isquêmico. Ao final, ressecou-se um segmento do intestino delgado para análise histológica. Avaliaram-se os resultados pela classificação de CHIU e col.6 e procedeu-se o tratamento estatístico. RESULTADOS: As médias dos graus de lesão tecidual foram: grupo A, 3,5; grupo B, 1,2; grupo C, 1. A diferença entre o resultado do grupo A com os resultados dos grupos B e C foi considerada estatisticamente significativa (p < 0,05). CONCLUSÃO: O pré e pós-condicionamento isquêmico foram capazes de minimizar a lesão tecidual na mucosa intestinal de ratos submetidos ao processo de isquemia e reperfusão mesentérica.