Neutrophil to lymphocyte ratio predicts bowel ischemia in non-strangulated adhesive small bowel occlusions: a retrospective analysis from an acute care surgical service.

BACKGROUND: Adhesive small bowel obstruction (ASBO) is a leading cause of hospitalization in emergency surgery. The occurrence of bowel ischemia significantly increases the morbidity and mortality rates associated with this condition. Current clinical, biochemical and radiological parameters have poor predictive value for bowel ischemia. This study is designed to ascertain predictive elements for the progression to bowel ischemia in patients diagnosed with non-strangulated ASBO who are initially managed through conservative therapeutic approaches. METHODS: The study was based on the previously collected medical records of 128 patients admitted to the Department of Acute Care Surgery of Padua General Hospital, from August 2020 to April 2023, with a diagnosis of non-strangulated adhesive small bowel obstruction, who were then operated for failure of conservative treatment. The presence or absence of bowel ischemia was used to distinguish the two populations. Clinical, biochemical and radiological data were used to verify whether there is a correlation with the detection of bowel ischemia. RESULTS: We found that a Neutrophil-Lymphocyte ratio (NLR) > 6.8 (OR 2.9; 95% CI 1.41-6.21), the presence of mesenteric haziness (OR 2.56; 95% CI 1.11-5.88), decreased wall enhancement (OR 4.3; 95% CI 3.34-10.9) and free abdominal fluid (OR 2.64; 95% CI 1.08-6.16) were significantly associated with bowel ischemia at univariate analysis. At the multivariate logistic regression analysis, only NLR > 6.8 (OR 5.9; 95% CI 2.2-18.6) remained independent predictive factor for small bowel ischemia in non-strangulated adhesive small bowel obstruction, with 78% sensitivity and 65% specificity. CONCLUSIONS: NLR is a straightforward and reproducible parameter to predict bowel ischemia in cases of non-strangulated adhesive small bowel obstruction. Employing NLR during reevaluation of patients with this condition, who were initially treated conservatively, can help the acute care surgeons in the early prediction of bowel ischemia onset.

Mesenteric sparing approach for advanced nodal extent in small intestinal neuroendocrine tumors. Is there a limit to the vascular resection in order to avoid creating a short small bowel syndrome? An anatomic research study.

PURPOSE: By selectively perfusing the first three jejunal arteries (JA), we aim to assess the individual perfusion length of small bowel (SB) and its impact on nodal resection in stage III-up small-intestinal neuroendocrine tumors (SI-NET). METHODS: Our anatomical research protocol implies a midline laparotomy and three measures of the SB length. We then perform a classical anterior approach of the superior mesenteric vessels. We carry on with the complete dissection and checking of the superior mesenteric artery (SMA) in order to identify the first three JA. Then we selectively perfuse each artery with colored latex solutions and measure the length of small bowel perfused respectively. RESULTS: We conducted our protocol on six cadaveric subjects. Mean(SD) SB length was 413(5.7), 535(13.2), 485(15), 353(25.1), 730(17.3) and 525(16° cm respectively from subject one to six. Most JA originated from the left side of the SMA. The first JA originated from its posterior wall in two subjects. Mean(SD) distance of origin of the first three JA was 4.6(1.3)cm, 6(1.1)cm and 7.1(0.9)cm respectively. Mean(SD) diameter of SMA was 10.8(3.3)mm. Mean diameter of the three first JA was 4(1.4)mm, 4(1.5)mm and 5(1.2)mm respectively. Mean(SD) SB length perfused by first and second JA was 224(14.9)cm, 175(8.6)cm, 238.3(7.6)cm, 84.3(5.1)cm, 233.3(5.8)cm and 218.3(10.4)cm respectively from subject one to six. CONCLUSION: We observed a trend suggesting that the first and second JA may sustain a SB length beyond the viable 1.5 m limit, implying the feasibility of stage III-up SI-NET resection with just two JA.

Hyperspectral imaging combined with blood oxygen saturation for in vivo analysis of small intestinal necrosis tissue.

Acute mesenteric ischemia (AMI) is a clinically significant vascular and gastrointestinal condition, which is closely related to the blood supply of the small intestine. Unfortunately, it is still challenging to properly discriminate small intestinal tissues with different degrees of ischemia. In this study, hyperspectral imaging (HSI) was used to construct pseudo-color images of oxygen saturation about small intestinal tissues and to discriminate different degrees of ischemia. First, several small intestine tissue models of New Zealand white rabbits were prepared and collected their hyperspectral data. Then, a set of isosbestic points were used to linearly transform the measurement data twice to match the reference spectra of oxyhemoglobin and deoxyhemoglobin, respectively. The oxygen saturation was measured at the characteristic peak band of oxyhemoglobin (560 nm). Ultimately, using the oxygenated hemoglobin reflectance spectrum as the benchmark, we obtained the relative amount of median oxygen saturation in normal tissues was 70.0 %, the IQR was 10.1 %, the relative amount of median oxygen saturation in ischemic tissues was 49.6 %, and the IQR was 14.6 %. The results demonstrate that HSI combined with the oxygen saturation computation method can efficiently differentiate between normal and ischemic regions of the small intestinal tissues. This technique provides a powerful support for internist to discriminate small bowel tissues with different degrees of ischemia, and also provides a new way of thinking for the diagnosis of AMI.

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.

Small Intestinal Arteriovenous Malformation Treated by Double-balloon Endoscopy.

A 42-year-old man was referred to our hospital because of anemia. The patient underwent gastroscopy and colonoscopy, but no bleeding site was detected. Abdominal contrast-enhanced computed tomography (CT) showed vascular dilatation along the wall of the small intestine. Small bowel capsule endoscopy and antegrade double-balloon endoscopy (DBE) were performed, and the patient was diagnosed with a small intestinal arteriovenous malformation (AVM). The AVM was clipped using DBE. After clipping, abdominal contrast-enhanced CT and small bowel angiography revealed the disappearance of the AVM. DBE may be a viable therapeutic option, helping avoid surgery and its associated risks.

Characterization of the intestinal graft in a swine hypotensive after brain death model

Abstract Purpose: To establish a hypotensive brain death pig model and observe the effects of hypotension on small bowel donors. Methods: The hypotensive brain death model was produced using the modified intracranial water sac inflation method in ten domestic crossbred pigs. Effects of hypotensive brain death on small bowel tissue morphology were evaluated through changes in intestinal tissue pathology, tight junction protein of the intestinal mucosa and plasma intestinal fatty acid-binding protein (i-FABP) levels. The pathophysiological mechanism was examined based on changes in superior mesenteric artery (SMA) blood flow and systemic hemodynamics. Results: After model establishment, SMA blood flow, and the mean arterial pressure (MAP) significantly decreased, while heart rate increased rapidly and fluctuated significantly. Small bowel tissue morphology and levels of tight junction protein of the intestinal mucosa showed that after model establishment, small bowel tissue injury was gradually aggravated over time (P<0.05). Plasma i-FABP levels significantly increased after brain death (P<0.05). Conclusions: A hypotensive brain death pig model was successfully established using an improved intracranial water sac inflation method. This method offers a possibility of describing the injury mechanisms more clearly during and after brain death.

The role of ischemic preconditioning in gene expression related to inflammation in a rat model of intestinal ischemia-reperfusion injury

Abstract Purpose: To investigate the gene expression related to inflammation on mice subjected to intestinal ischemia and reperfusion (I/R) and treated with ischemic preconditioning (IPC). Methods: Thirty rats (EPM-Wistar), distributed in five groups of six animals each, were underwent anesthesia and laparotomy. The ischemia time was standardized in 60 minutes and the reperfusion time 120 minutes. IPC was standardized in 5 minutes of ischemia followed by 10 minutes of reperfusion accomplished before I/R. The control group was submitted only to anesthesia and laparotomy. The other groups were submitted to ischemia, I/R, ischemia + IPC and I/R + IPC. It was collected a small intestine sample to analyses by Quantitative Polymerase Chain Reaction in real Time (RT-qPCR) and histological analyses. It was studied 27 genes. Results: The groups that received IPC presented downregulation of genes, observed in of genes in IPC+ischemia group and IPC+I/R group. Data analysis by clusters showed upregulation in I/R group, however in IPC groups occurred downregulation of genes related to inflammation. Conclusion: The ischemia/reperfusion promoted upregulation of genes related to inflammation, while ischemic preconditioning promoted downregulation of these genes.

The role of atenolol in the modulation of the expression of genes encoding pro- (caspase-1) and anti- (Bcl2L1) apoptotic proteins in endothelial cells exposed to intestinal ischemia and reperfusion in rats

Abstract Purpose: To investigate the role of atenolol in the gene expression of caspase 1 (Casp1) and Bcl2L1 on vascular endothelium of rat intestine after ischemia and reperfusion (IR). Methods: Eighteen adult male Wistar rats were randomly divided into 3 groups (n=6): SG (Sham group): no clamping of the superior mesenteric artery; IRG: IR plus saline group: IRG+At: IR plus Atenolol group. Rats from IRG and IRG+At were subjected to 60 min of intestinal ischemia and 120 min of reperfusion. Atenolol (2mg/kg) or saline were injected in the femoral vein 5 min before ischemia, 5 min and 55 min after reperfusion. Thereafter, intestinal segments were appropriately removed and processed for Endothelial Cell Biology Rat RT2 Profiler PCR Array. Results: the anti-apoptotic Bcl2L1 gene expression was significantly down-regulated (-1.10) in the IRG and significantly up-regulated in the IRG+At (+14.15). Meanwhile, despite Casp1 gene expression was upregulated in both groups, it was significantly higher in the IRG (+35.06) than the IRG+At (+6.68). Conclusions: Atenolol presents antiapoptotic effects on rat intestine subjected to IR partly by the up-regulation of the anti-apoptotic Bcl2L1 gene expression. Moreover, atenolol can mitigate the pro-apoptotic and pro-inflammatory effects of Casp1 gene on rat intestine after IR.

Remote ischemic preconditioning and tacrolimus in the fetal small bowel transplant in mice

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.

The influence of nicotine in healing of small bowel anastomoses in rats: angiogenesis and miofibroblasts / A influência da nicotina na cicatrização de anastomoses do intestino delgado em ratos: angiogênese e miofibroblastos

ABSTRACT Objective: to know the effect of nicotine on angiogenesis and myofibroblast formation in anastomoses of the small bowel of rats. Methods: we randomly divided 60 Wistar rats into the groups Nicotine (N) and control (C), according to the proposed treatment. Each group was subdivided into three subgroups according to the time interval used for the evaluation (7, 14 or 28 days). The N group with 30 animals received nicotine subcutaneously at a dose of 2mg/kg body weight, diluted in 0.3ml of 0.9% saline, twice daily for 28 days prior to the operation, and for more 7, 14 or 28 days, depending on the subgroup. The C group (also 30 animals) received only saline on the same conditions and time intervals. After 28 days we carried out an end-to-end anastomosis 10cm distal to the duodenojejunal flexure in each rat. After 7, 14 or 28 days after surgery, we euthanized ten animals of each group, sent specimens of the anastomosis areas, 1cm proximal to 1cm distal, to counting of blood vessels and myofibroblasts through immunohistochemical staining by the application of monoclonal anti-factor VIII antibodies and anti-smooth muscle alpha-actin. Results: the administration of nicotine led to the decrease in the number of blood vessels measured on the 28th postoperative day and the number of myofibroblasts measured on the seventh day following completion of the anastomoses. Conclusion: administration of nicotine was deleterious on angiogenesis and myofibroblast formation in rats' small intestine anastomoses.

RESUMO Objetivo: conhecer o efeito da nicotina sobre a angiogênese e formação de miofibroblastos em anastomoses do intestino delgado de ratos. Métodos: sessenta ratos Wistar foram divididos de maneira aleatória em grupos Nicotina(N) e Controle (C), conforme o tratamento proposto. Cada grupo foi subdividido em três subgrupos, de acordo com o intervalo de tempo utilizado para a avaliação (7, 14 ou 28 dias). O grupo N, com 30 animais, recebeu nicotina por via subcutânea, na dose de 2mg/Kg de peso, diluída em 0,3ml de solução salina a 0,9%, em duas aplicações diárias, durante 28 dias prévios à operação e por mais 7, 14 ou 28 dias, conforme o subgrupo. O grupo C (igualmente com 30 animais) recebeu somente a solução salina nas mesmas condições e intervalos de tempo. Após 28 dias efetuou-se, em cada rato, anastomose término-terminal a 10cm da flexura duodenojejunal. Após 7, 14 ou 28 dias da cirurgia, os dez animais de cada subgrupo foram eutanasiados, sendo que as áreas anastomosadas, 1cm proximal a 1cm distal, foram encaminhadas para contagem de vasos sanguíneos e miofibroblastos, através de coloração imuno-histoquímica por aplicação dos anticorpos monoclonais antifator VIII e anti-alfa-actina muscular lisa. Resultados: a administração de nicotina levou à diminuição do número de vasos sanguíneos aferidos no 28o dia pós-operatório e do número de miofibroblastos aferidos no sétimo dia após a realização das anastomoses. Conclusão: a administração de nicotina foi deletéria sobre a angiogênese e formação de miofibroblastos em anastomoses do intestino delgado de ratos.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia

Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC). This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group): 1) preterm control (PTC), 2) preterm ventilated (PTV), 3) preterm asphyxiated (PTA), 4) preterm asphyxiated and ventilated (PTAV), 5) term control (TC), 6) term ventilated (TV), 7) term asphyxiated (TA), and 8) term asphyxiated and ventilated (TAV). We measured body, brain, and intestine weights and respective ratios [(BW), (BrW), (IW), (BrW/BW) and (IW/BW)]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus) and intestine (jejunum/ileum) tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP). IW was lower in the TA than in the other terms (P<0.05), and the IW/BW ratio was lower in the TA than in the TAV (P<0.005). PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex) and TA (cortex/hippocampus) (P<0.005). I-FABP was higher in PTAV (P<0.005) and TA (ileum) (P<0.05). I-FABP expression was increased in PTAV subgroup (P<0.0001). Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers.

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. .

Expressao genica associada ao estresse oxidativo no coracao de camundongo apos isquemia intestinal / Gene expression related to oxidative stress in the heart of mice after intestinal ischemia

FUNDAMENTO: O fenômeno da isquemia e reperfusão intestinal é um evento frequente na clínica e está associado a repercussões deletérias em órgãos a distância, em especial ao coração. OBJETIVO: Investigar a expressão gênica do estresse oxidativo e defesa antioxidante no coração de camundongos isogênicos, submetidos a isquemia e reperfusão intestinal (IR). MÉTODOS: Doze camundongos (C57BL/6) foram distribuídos em dois grupos: Grupo IR (GIR) com 60 min de oclusão da artéria mesentérica superior, seguidos de 60 min de reperfusão. Grupo Controle (GC) submetidos a anestesia e a laparotomia sem o procedimento de IR observados por 120 min. As amostras de intestino e coração foram processadas pelo método (RT-qPCR / Reverse transcriptase - quantitative Polymerase Chain Reaction) para determinar a expressão gênica de 84 genes relacionados ao estresse oxidativo ("t" de Student, p < 0,05). RESULTADOS: Observou-se no tecido intestinal (GIR) uma expressão significantemente aumentada em 65 (74,71%) genes em relação ao tecido normal (GC), e 37 (44,04%) genes estiveram hiperexpressos (maior que três vezes o limiar permitido pelo algoritmo). No tocante aos efeitos da I/R intestinal a distância no tecido cardíaco verificou-se a expressão significantemente aumentada de 28 genes (33,33%), mas somente oito genes (9,52%) se hiperexpressaram três vezes acima do limiar. Quatro (7,14%) desses oito genes se expressaram simultaneamente nos tecidos intestinal e cardíaco. No GIR notaram-se cardiomiócitos com núcleos de menor tamanho, picnóticos, ricos em heterocromatina e raros nucléolos, indicando sofrimento cardíaco. CONCLUSÃO: A I/R intestinal promoveu a hiperexpressão estatisticamente significante de oito genes associados ao ...

BACKGROUND: Intestinal ischemia-reperfusion is a frequent clinical event associated to injury in distant organs, especially the heart. OBJECTIVE: To investigate the gene expression of oxidative stress and antioxidant defense in the heart of inbred mice subjected to intestinal ischemia and reperfusion (IR). METHODS: Twelve mice (C57BL / 6) were assigned to: IR Group (GIR) with 60 minutes of superior mesenteric artery occlusion followed by 60 minutes of reperfusion; Control Group (CG) which underwent anesthesia and laparotomy without IR procedure and was observed for 120 minutes. Intestine and heart samples were processed using the RT-qPCR / Reverse transcriptase-quantitative Polymerase Chain Reaction method for the gene expression of 84 genes related to oxidative stress and oxidative defense (Student's "t" test, p < 0.05). RESULTS: The intestinal tissue (GIR) was noted to have an up-regulation of 65 genes (74.71%) in comparison to normal tissue (CG), and 37 genes (44.04%) were hyper-expressed (greater than three times the threshold allowed by the algorithm). Regarding the remote effects of intestinal I/R in cardiac tissue an up-regulation of 28 genes (33.33%) was seen, but only eight genes (9.52%) were hyper-expressed three times above threshold. Four (7.14%) of these eight genes were expressed in both intestinal and cardiac tissues. Cardiomyocytes with smaller and pyknotic nuclei, rich in heterochromatin with rare nucleoli, indicating cardiac distress, were observed in the GIR. CONCLUSION: Intestinal I/R caused a statistically significant over expression of 8 genes associated with oxidative stress in remote myocardial tissue. .

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. .

Oxidative stress gene expression profile in inbred mouse after ischemia/reperfusion small bowel injury / Perfil da expressão gênica do estresse oxidativo em camundongos isogênicos após lesão de isquemia e reperfusão intestinal

PURPOSE: To determine the profile of gene expressions associated with oxidative stress and thereby contribute to establish parameters about the role of enzyme clusters related to the ischemia/reperfusion intestinal injury. METHODS: Twelve male inbred mice (C57BL/6) were randomly assigned: Control Group (CG) submitted to anesthesia, laparotomy and observed by 120min; Ischemia/reperfusion Group (IRG) submitted to anesthesia, laparotomy, 60min of small bowel ischemia and 60min of reperfusion. A pool of six samples was submitted to the qPCR-RT protocol (six clusters) for mouse oxidative stress and antioxidant defense pathways. RESULTS: On the 84 genes investigated, 64 (76.2%) had statistic significant expression and 20 (23.8%) showed no statistical difference to the control group. From these 64 significantly expressed genes, 60 (93.7%) were up-regulated and 04 (6.3%) were down-regulated. From the group with no statistical significantly expression, 12 genes were up-regulated and 8 genes were down-regulated. Surprisingly, 37 (44.04%) showed a higher than threefold up-regulation and then arbitrarily the values was considered as a very significant. Thus, 37 genes (44.04%) were expressed very significantly up-regulated. The remained 47 (55.9%) genes were up-regulated less than three folds (35 genes - 41.6%) or down-regulated less than three folds (12 genes - 14.3%). CONCLUSION: The intestinal ischemia and reperfusion promote a global hyper-expression profile of six different clusters genes related to antioxidant defense and oxidative stress.

OBJETIVO: Determinar o perfil de expressão dos genes associados com estresse oxidativo e contribuir para estabelecer parâmetros sobre o papel das familias de enzimas relacionadas com a lesão de isquemia / reperfusão intestinal. MÉTODOS: Doze camundongos machos isogênicos (C57BL/6) foram distribuídos aleatoriamente: Grupo Controle (CG) submetido à laparotomia anestesia, e observado por 120min; Grupo isquemia/reperfusão (IRG) submetido à anestesia, laparotomia, 60min de isquemia do intestino delgado e 60min de reperfusão. Um pool dos seis camundongos de cada grupo foi submetido ao protocolo de qPCR-RT (seis famílias) para o estresse oxidativo e defesa antioxidante. RESULTADOS: Dos 84 genes investigados, 64 (76,2%) tiveram expressão estatística significante e 20 (23,8%) não apresentaram diferença estatística com o grupo controle. Dos 64 genes expressos de forma significante, 60 (93,7%) foram hiper-expressos e 04 (6,3%) foram hipo-expressos. Do grupo sem expressão estatisticamente significante, 12 genes foram hiper e 8 genes foram hipo-expressos. Surpreendentemente, 37 (44,04%) apresentaram expressão três maior que o limiar de normalidade e arbitrariamente os valores foram considerados como altamente significantes. Assim, 37 genes (44,04%) foram hiper-expressos de modo muito significante. Nos demais, 47 (55,9%) dos genes foram hiper-expressos menos de três vezes (35 genes - 41,6%) ou hipo-expressos menos de três vezes(12 genes - 14,3%). CONCLUSÃO: A isquemia e reperfusão intestinal promoveu um perfil de hiper-expressão global das seis familias de genes relacionados com estresse oxidativo antioxidante e defesa antioxidante.

Experiencia en el uso de la cápsula endoscópica de intestino delgado en pacientes con sangrado gastrointestinal oscuro / Experience in use of capsule endoscopica of thin intestine in patients with bled dark gastrointestinal

La cápsula endoscópica es un método diagnóstico que evalúa el tracto gastrointestinal de forma no invasiva. La principal indicación del estudio es la determinación del origen del sangrado gastrointestinal oscuro. Dicha entidad clínica se define, como la hemorragia digestiva de causa desconocida, persistente y recurrente, después de una prueba negativa en el estudio endoscópico convencional. (Colonoscopia – endoscopia digestiva superior). Objetivo: Describir hallazgos de la cápsula endoscópica en pacientes con hemorragias digestivas de origen oscuro. Pacientes y Métodos: Estudio descriptivo de corte trasversal. Se evaluaron 19 pacientes con hemorragia digestiva de origen oscuro que acudieron al Servicio de Gastroenterología del centro de cuarto nivel durante el periodo de marzo 2009 – marzo 2010, excluyéndose a pacientes en estado crítico o terminal, y aquellos con clínica de obstrucción intestinal o fistulas. Utilizando plataforma Given Imaging® SB2. Resultados: Se estudiaron 19 pacientes, 14 (73,68%) sexo masculino, 5 (26,31%) sexo femenino, grupo etáreo comprendido entre 29-60 años edad promedio 39.5 años. Indicación: sangrado digestivo oculto: 6 casos (31.57%). Sangrado digestivo oscuro: 13 caso (68.42 %). Hallazgos en 16 pacientes (84.21%): sangrado activo profuso localizado de causa indeterminada (6.25%), úlceras y erosiones (37.5%), lesión de aspecto tumoral sangrante activo (12,5%), angiodisplasia (37.5%), pólipos (6.25%). Tres casos (15,78%) con evaluación limitada por mala preparación. Conclusión: La cápsula endoscópica se considera en la actualidad una herramienta útil para la detección de lesiones en intestino delgado, siendo la principal indicación en la hemorragia gastrointestinal de origen oscuro. Con un rendimiento diagnóstico de 84% en la evaluación de la Hemorragias Digestiva oscura oculta.

The endoscópica capsule is a method diagnosis that evaluates tracto gastrointestinal of noninvasive form. The main indication of the study is the determination of the origin of bled gastrointestinal dark. This clinical organization is defined, like the digestive hemorrhage of cause unknown, persistent and recurrent, after one proves refusal in the conventional endoscópico study. (Colonoscopia - superior digestive endoscopia). Objective: To describe findings of the endoscópica capsule in patients with digestive hemorrhages of dark origin. Patients and Methods: Descriptive study of trasversal cut. 19 patients with digestive hemorrhage of dark origin evaluated themselves that they went to the Service of Gastroenterology of the center of fourth level during the period of March 2009 - March 2010, excluding itself patients in critical or terminal state, and those with intestinal clinic of obstruction or fistulas. Using platform Given Imaging® SB2. Results: 19 patients studied, 14 (73.68%) masculine sex, 5 (26.31%) feminine sex, etáreo group included/understood between 29-60 years age average 39,5 years. Indication: bled digestive hidden: 6 cases (31,57%). Bled digestive dark: 13 case (68,42%). Findings in 16 patients (84,21%): bled active profuse located of indetermine cause (6,25%), ulcers and erosions (37,5%), injury of tumorlike aspect bleeding assets (12.5%), angiodisplasia (37,5%), polyps (6,25%). Three cases (15.78%) with evaluation limited by bad preparation. Conclusion: The endoscópica capsule considers at the present time a useful tool for the detection of injuries in thin intestine, being the main indication in the gastrointestinal he-morrhage of dark origin. With a yield diagnosis of 84% in the evaluation of the Hemorrhages Digestive dark hidden.

Effect of glutamine on the mRNA level of key enzymes of malate-aspartate shuttle in the rat intestine subjected to ischemia reperfusion / Efeito da glutamina sobre o nível de RNA Mensageiro das enzimas-chave do ciclo malato-aspartato no intestino de ratos submetidos à isquemia e reperfusão

PURPOSE: To determine the effects of oral L-glutamine (L-Gln) and the dipeptide l-alanyl-glutamine (L-Ala-Gln) upon the activity of the malate-aspartate shuttle in the rat distal small intestine following ischemia and reperfusion. METHODS: Seventy-two Wistar rats (350-400g), were randomized in 2 groups (n = 36): group S (Sham) and Group T (Treatment) and divided into 12 subgroups (n = 6): A-A6, and B1-B6. The subgroups A1-A3 were subjected to sham procedures at 30 and 60 minutes. Thirty minutes before the study, rats were treated with calcium caseinate, 0.5g/Kg (subgroups A1, A4, B1, B4), L-Gln, 0.5g / kg (subgroups A2, A5, B2 and B5) or L-Ala-Gln, 0.75g/Kg (subgroups A3, A6, B3, B6), administered by gavage. Ischemia was achieved by clamping the mesenteric vessels, delimiting a segment of bowel 5 cm long and 5 cm apart from the ileocecal valve. Samples were collected 30 and 60 minutes after start of the study for real-time PCR assay of malate dehydrogenases (MDH1-2) and aspartate-aminotransferases (GOT1-2) enzymes. RESULTS: Tissue MDH and GOT mRNA expression in intestinal samples from rats preconditioned with either L-Gln or L-Ala-Gln showed no significant differences both during ischemia and early reperfusion. CONCLUSION: Activation of the malate-aspartate shuttle system appears not to be the mechanism of glutamine-mediated elevation of glucose oxidation in rat intestine during ischemia/reperfusion injury.

OBJETIVO: Determinar os efeitos da administração oral de L-glutamina (L-Gln) e do dipeptídeo L-alanil-glutamina (L-Ala-Gln) sobre a atividade do ciclo malato-aspartato no intestino delgado distal de ratos após isquemia/reperfusão. MÉTODOS: Setenta e dois ratos Wistar (350-400g) foram randomizados em 2 grupos (n = 36): T grupo S (Sham) e grupo (Tratamento) e distribuídos em 12 subgrupos (n = 6): A-A6, e B1-B6. Os subgrupos A1-A3 foram submetidos a procedimentos "sham" aos 30 e 60 minutos. Trinta minutos antes do estudo, os ratos foram tratados com caseinato de cálcio, 0,5 g/kg (subgrupos A1, A4, B1 e B4), L-Gln, 0,5 g/kg (subgrupos A2, A5, B2 e B5) ou L-Ala -Gln, 0,75g/kg (subgrupos A3, A6, B3, B6), administrado por gavagem. A isquemia foi obtida por pinçamento dos vasos mesentéricos, delimitando um segmento do intestino cinco centímetros de comprimento e 5 cm da válvula ileocecal. Amostras foram coletadas aos 30-60 minutos para ensaio de PCR em tempo real das enzimas malato desidrogenases (MDH1-2), aspartato-aminotransferase (GOT1-2). RESULTADOS: A expressão de MDH e GOT mRNA nas amostras provenientes do intestino delgado de ratos pré-condicionados com L-Gln ou L-Ala-Gln não apresentou diferenças significativas, tanto durante a isquemia como na fase inicial de reperfusão. CONCLUSÃO: Ativação do ciclo malato-aspartato não parece ser o mecanismo de elevação glutamina-mediada da oxidação da glicose no intestino de ratos durante a isquemia / reperfusão.

Effects of ischemic preconditioning associated to different preservation solutions in protecting the intestinal graft / Efeitos do precondicionamento isquêmico associado a diferentes soluções de preservação na proteção do enxerto intestinal

PURPOSE: To evaluate the effects of ischemic preconditioning (IPC) associate with different preservation solutions, in the protecting of gut. METHODS: Four groups of 14 rats underwent laparotomy and collecting 20 cm of ileum, for preservation, at 4ºC, in Belzer (Belz), Ringer (RL), Celsior (Cs) and Custodiol (Cust) solutions, for 24 hours. Prior to collection, half of the animals in each group were subjected to IPC. During preservation, in the periods of zero, 12, 18 and 24 hours, were conducted evaluating the degree of mucosal injury and dosage of malondialdehyde acid (MDA). RESULTS: In all periods the RL group, with and without IPC, presented MDA values higher than the Belz and Cs. The degree of mucosal injury in the non-ipc RLgroup with 12h preservation was higher than the others; with 18 and 24h, the RL and Cust had higher degrees of damage than Cs and Belz. With IPC, in all periods, the group Cs and Belz had lower degrees of injury. CONCLUSION: The Celsior and Belzer solutions had better protective effects on the gut and these effects were enhanced by IPC.

OBJETIVO: Avaliar os efeitos do precondicionamento isquêmico (PCI) associado a diferentes soluções de preservação, na proteção do intestino delgado. MÉTODOS: Quatro grupos de 14 ratos Wistar, foram submetidos à laparotomia e coleta de 20 cm de íleo, para preservação, a 4ºC, nas soluções de Belzer (Belz), Ringer (RL), Celsior (Cs) e Custodiol (Cust) por 24 horas. Previamente à coleta, em metade dos animais de cada grupo, o intestino foi submetido ao PCI. Durante a preservação, nos períodos de Zero, 12, 18 e 24 horas, foram realizados avaliação do grau de lesão da mucosa e dosagem do ácido malondialdeído (MDA). RESULTADOS: Em todos os períodos o grupo RL, sem e com pci, apresentou valores maiores de MDA do que o Belz e Cs. O grau de lesão da mucosa nos grupos sem pci com preservação de 12h, no grupo RL, foi maior que nos demais; com 18h e 24h o grupo RL e Cust apresentaram maiores graus de lesão do que Cs e Belz. Com o pci, em todos os períodos, os grupos Belz e Cs apresentaram menores graus de lesão CONCLUSÃO: As Soluções Celsior e Belzer tiveram melhores efeitos na proteção do intestino e estes efeitos foram incrementados pelo precondicionamento isquêmico.

Effect of short-term ornithine alpha-ketoglutarate pretreatment on intestinal ischemia-reperfusion in rats / Efeitos do pré-tratamento em curto prazo com ornitina alfa-cetoglutarato na isquemia-reperfusão intestinal em ratos

PURPOSE: To investigate the effects of preventive enteral administration of ornithine alpha-ketoglutarate (OKG) in an ischemia-reperfusion rat model. METHODS: Sixty rats were randomized into five groups (G1-G5, n = 12). Each group was divided into two subgroups (n = 6) and treated with calcium carbonate (CaCa) or OKG by gavage. Thirty minutes later, the animals were anesthetized with xylazine 15mg + ketamine 1mg ip and subjected to laparotomy. G1-G3 rats served as controls. Rats in groups G4 and G5 were subjected to ischemia for 30 minutes. Ischemia was achieved by clamping the small intestine and its mesentery, delimiting a segment of bowel 5 cm long and 5 cm apart from the ileocecal valve. In addition, G5 rats underwent reperfusion for 30 minutes. Blood samples were collected at the end of the laparotomy (G1), after 30 minutes (G2, G4) and 60 minutes (G3, G5) to determine concentrations of metabolites (pyruvate, lactate), creatine phosphokinase (CPK), thiobarbituric acid reactive substances (TBARS) and glutathione (GSH). RESULTS: There was a significant decrease in tissue pyruvate and lactate and plasma CPK levels in OKG-treated rats at the end of reperfusion period. GSH levels did not change significantly in ischemia and reperfusion groups. However, TBARS levels increased significantly (p<0.05) in tissue samples in OKG-treated rats subjected to ischemia for 30 minutes. CONCLUSION: Short-term pretreatment with OKG before induction of I/R decreases tissue damage, increases pyruvate utilization for energy production in the Krebs cycle and does not attenuate the oxidative stress in this animal model.

OBJETIVO: Investigar os efeitos da administração enteral preventiva de ornitina alfa-cetoglutarato (OKG) em modelo de isquemia-reperfusão no rato. MÉTODOS: Sessenta ratos foram randomizados em cinco grupos (G1-G5, n=12). Cada grupo foi redistribuído em dois subgrupos (n=6) e tratado com carbonato de cálcio (CaCa) ou OKG por gavagem. Trinta minutos mais tarde, os animais foram anestesiados com xilazina 1mg+cetamina 15mg i.p. e submetidos à laparotomia. Os ratos dos grupos G4-G5 foram submetidos à isquemia por 30 minutos. A isquemia foi obtida por pinçamento do intestino delgado, delimitando um segmento com 5 cm de comprimento e distando 5 cm da válvula ileocecal. O grupo G5 foi submetido à reperfusão por 30 minutos. Amostras de sangue foram coletadas no final da laparotomia (G1), após 30 minutos (G2, G4) e 60 minutos (G3, G5) para determinação das concentrações de metabolitos (piruvato, lactato), creatinofosfoquinase (CPK), substâncias reativas ao ácido tiobarbitúrico (TBARS) e glutationa (GSH). RESULTADOS: Observou-se redução significante (p<0,05) das concentrações de piruvato e lactato, teciduais e CPK plasmático em ratos tratados com OKG, no final do período de reperfusão. Não houve alteração significante nos níveis plasmáticos e teciduais de GSH. Entretanto os níveis de TBARS aumentaram significativamente (p<0,05) em amostras de tecido de ratos tratados com OKG submetido à isquemia por 30 minutos. CONCLUSÃO: o pré-tratamento em curto prazo com OKG antes da indução da I/R diminui a lesão tecidual, aumenta a utilização de piruvato para produção de energia no ciclo de Krebs, mas não atenua o estresse oxidativo neste modelo animal.