Predicting short-term major postoperative complications in intestinal resection for Crohn's disease: A machine learning-based study.

BACKGROUND: Due to the complexity and numerous comorbidities associated with Crohn's disease (CD), the incidence of postoperative complications is high, significantly impacting the recovery and prognosis of patients. Consequently, additional studies are required to precisely predict short-term major complications following intestinal resection (IR), aiding surgical decision-making and optimizing patient care. AIM: To construct novel models based on machine learning (ML) to predict short-term major postoperative complications in patients with CD following IR. METHODS: A retrospective analysis was performed on clinical data derived from a patient cohort that underwent IR for CD from January 2017 to December 2022. The study participants were randomly allocated to either a training cohort or a validation cohort. The logistic regression and random forest (RF) were applied to construct models in the training cohort, with model discrimination evaluated using the area under the curves (AUC). The validation cohort assessed the performance of the constructed models. RESULTS: Out of the 259 patients encompassed in the study, 5.0% encountered major postoperative complications (Clavien-Dindo ≥ III) within 30 d following IR for CD. The AUC for the logistic model was 0.916, significantly lower than the AUC of 0.965 for the RF model. The logistic model incorporated a preoperative CD activity index (CDAI) of ≥ 220, a diminished preoperative serum albumin level, conversion to laparotomy surgery, and an extended operation time. A nomogram for the logistic model was plotted. Except for the surgical approach, the other three variables ranked among the top four important variables in the novel ML model. CONCLUSION: Both the nomogram and RF exhibited good performance in predicting short-term major postoperative complications in patients with CD, with the RF model showing more superiority. A preoperative CDAI of ≥ 220, a diminished preoperative serum albumin level, and an extended operation time might be the most crucial variables. The findings of this study can assist clinicians in identifying patients at a higher risk for complications and offering personalized perioperative management to enhance patient outcomes.

The role of the CXCR6/CXCL16 axis in the pathogenesis of fibrotic disease.

CXC chemokine receptor 6 (CXCR6), a seven-transmembrane domain G-protein-coupled receptor, plays a pivotal regulatory role in inflammation and tissue damage through its interaction with CXC chemokine ligand 16 (CXCL16). This axis is implicated in the pathogenesis of various fibrotic diseases and correlates with clinical parameters that indicate disease severity, activity, and prognosis in organ fibrosis, including afflictions of the liver, kidney, lung, cardiovascular system, skin, and intestines. Soluble CXCL16 (sCXCL16) serves as a chemokine, facilitating the migration and recruitment of CXCR6-expressing cells, while membrane-bound CXCL16 (mCXCL16) functions as a transmembrane protein with adhesion properties, facilitating intercellular interactions by binding to CXCR6. The CXCR6/CXCL16 axis is established to regulate the cycle of damage and repair during chronic inflammation, either through modulating immune cell-mediated intercellular communication or by independently influencing fibroblast homing, proliferation, and activation, with each pathway potentially culminating in the onset and progression of fibrotic diseases. However, clinically exploiting the targeting of the CXCR6/CXCL16 axis requires further elucidation of the intricate chemokine interactions within fibrosis pathogenesis. This review explores the biology of CXCR6/CXCL16, its multifaceted effects contributing to fibrosis in various organs, and the prospective clinical implications of these insights.

Timing of individualized surgical intervention in Crohn's disease.

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract with an increasing incidence worldwide. Comprehensive therapy for CD focuses on symptom control and healing the intestinal mucosa to improve the quality of life and prevent complications. Surgical intervention plays a vital role in comprehensive therapy. However, deciding the optimal timing for surgical intervention has long been a focus of controversy. This review provides insights into the timing of surgery for CD and guides clinicians in daily treatment.

Laparoscopic vs open surgery in ileostomy reversal in Crohn's disease: A retrospective study.

BACKGROUND: Although minimally invasive surgery is becoming more commonly applied for ileostomy reversal (IR), there have been relatively few studies of IR for patients with Crohn's disease (CD). It is therefore important to evaluate the potential benefits and risks of laparoscopy for patients with CD. AIM: To compare the safety, feasibility, and short-term and long-term outcomes of laparoscopic IR (LIR) vs open IR (OIR) for the treatment of CD. METHODS: The baseline characteristics, operative data, and short-term (30-d) and long-term outcomes of patients with CD who underwent LIR and OIR at our institution between January 2017 and January 2020 were retrieved from an electronic database and retrospectively reviewed. RESULTS: Of the 60 patients enrolled in this study, LIR was performed for 48 and OIR for 12. There were no statistically significant differences in baseline characteristics, operation time, intraoperative blood loss, days to flatus and soft diet, postoperative complications, hospitalization time, readmission rate within 30 d, length of hospitalization, hospitalization costs, or reoperation rate after IR between the two groups. However, patients in the LIR group more frequently required lysis of adhesions as compared to those in the OIR group (87.5% vs 41.7%, respectively, P < 0.05). Notably, following exclusion of patients who underwent enterectomy plus IR, OIR was more advantageous in terms of postoperative recovery of gastrointestinal function and hospitalization costs. CONCLUSION: The safety and feasibility of LIR for the treatment of CD are comparable to those of OIR with no increase in intraoperative or postoperative complications.

Laparoscopy for Crohn's disease: A comprehensive exploration of minimally invasive surgical techniques.

BACKGROUND: Along with the unceasing progress of medicine, Crohn's disease (CD), especially complex CD, is no longer a taboo for minimally invasive surgery. However, considering its special disease characteristics, more clinical trials are needed to confirm the safety and feasibility of laparoscopic surgery for CD. AIM: To investigate the safety and feasibility of laparoscopic enterectomy for CD, assess the advantages of laparoscopy over laparotomy in patients with CD, and discuss comprehensive minimally invasive surgical techniques in complex CD. METHODS: This study prospectively collected clinical data from patients with CD who underwent enterectomy from January 2017 to January 2020. It was registered in the Chinese clinical trial database with the registration number ChiCTR-INR-16009321. Patients were divided into a laparoscopy group and a traditional laparotomy group according to the surgical method. The baseline characteristics, operation time, intraoperative blood loss, temporary stoma, levels of abdominal adhesion, pathological characteristics, days to flatus and soft diet, postoperative complications, hospitalization time, readmission rate within 30 d, and hospitalization cost were compared between the two groups. RESULTS: A total of 120 eligible patients were enrolled into the pre-standardized groups, including 100 in the laparoscopy group and 20 in the laparotomy group. Compared with the laparotomy group, the postoperative hospitalization time in the laparoscopy group was shorter (9.1 ± 3.9 d vs 11.0 ± 1.6 d, P < 0.05), the days to flatus were fewer (2.8 ± 0.8 d vs 3.5 ± 0.7 d, P < 0.05), the days to soft diet were fewer (4.2 ± 2.4 d vs 6.2 ± 2.0 d, P < 0.05) and the intraoperative blood loss was less (103.3 ± 80.42 mL vs 169.5 ± 100.42 mL, P < 0.05). There were no statistically significant differences between the two groups in preoperative clinical data, operation time (149.0 ± 43.8 min vs 159.2 ± 40.0 min), stoma rate, levels of abdominal adhesion, total cost of hospitalization, incidence of postoperative complications [8.0% (8/100) vs 15.0% (3/20)], or readmission rate within 30 days [1.0% (1/100) vs 0.00 (0/20)]. CONCLUSION: Compared with laparotomy, laparoscopic enterectomy promotes the recovery of gastrointestinal function, shortens the postoperative hospitalization time, and does not increase the incidence of postoperative complications. Laparoscopic enterectomy combined with varieties of minimally invasive surgical techniques is a safe and acceptable therapeutic method for CD patients with enteric fistulas.

Minimally invasive surgery for glycogen storage disease combined with inflammatory bowel disease: A case report.

BACKGROUND: Inflammatory bowel disease (IBD) is rare in patients with glycogen storage disease (GSD). In GSD patients, a decrease in the number of neutrophils leads to prolonged intestinal infection, leading to the formation of chronic inflammation and eventually the development of IBD. Minimally invasive surgery for patients with IBD has been proven to reduce inflammatory responses and postoperative risks and ultimately promote rapid recovery. Herein we discuss minimally invasive surgery and the perioperative management in a patient with GSD and IBD. CASE SUMMARY: A 23-year-old male had GSD Ib associated with IBD-like disease for 10 years. Despite standard treatments, such as mesalazine, prednisone and adalimumab, the patient eventually developed colonic stenosis with incomplete ileus. After adequate assessment, the patient was treated with minimally invasive surgery and discharged in stable condition. CONCLUSION: Minimally invasive surgery for patients with IBD and GSD is safe, feasible and effective.

Mast Cell Tryptase Promotes Inflammatory Bowel Disease-Induced Intestinal Fibrosis.

BACKGROUND: Intestinal fibrosis is the final pathological outcome of chronic intestinal inflammation without specific therapeutic drugs, which leads to ileus and surgical intervention. Intestinal fibrosis is characterized by excessive deposition of extracellular matrix (ECM). The role of mast cells (MCs), which are members of the sentinel immune cell population, is unknown in intestinal fibrosis. METHODS: In this study, we analyzed changes in MCs, tryptase proteins, and ECM components in human fibrotic and control patient intestines. We constructed dextran sodium sulfate-induced intestinal fibrosis models using wild-type mice, MC-reconstituted mice, and MC-deficient mice to explore the role of MCs and tryptase in intestinal fibrosis. The roles and mechanisms of MCs and tryptase on fibroblasts were evaluated using human MCs (HMC-1 and LAD-2), commercial tryptase proteins, human colon fibroblasts (CCD-18Co fibroblasts), the tryptase inhibitor APC366, and the protease-activated receptor-2 (PAR-2) antagonist ENMD-1068. RESULTS: Regardless of whether the colon was a human colon or a mouse colon, the fibrotic intestinal tissue had increased MC infiltration and a higher expression of ECM proteins or genes than that of the control group. The dextran sodium sulfate-induced intestinal fibrosis in MC-deficient mice was alleviated compared with that in wild-type mice. After MC reconstruction in MC-deficient mice, the alleviating effect disappeared. Tryptase, as a content stored in MC granules, was released into fibrotic intestinal tissues in the form of degranulation, resulting in an increased expression of tryptase. Compared with the control group, the tryptase inhibition group (the APC366 group) had reduced intestinal fibrosis. The CCD-18Co fibroblasts, when cocultured with MCs or treated with tryptase proteins, were activated to differentiate into myofibroblasts and secrete more ECM proteins (such as collagen and fibronectin). The underlying mechanism of fibroblast activation by tryptase was the activation of the PAR-2/Akt/mTOR pathway. CONCLUSIONS: We found that MC tryptase promotes inflammatory bowel disease-induced intestinal fibrosis. The underlying mechanism is that tryptase promotes the differentiation of fibroblasts into fibrotic-phenotype myofibroblasts by activating the PAR-2/Akt/ mTOR pathway of fibroblasts.

Protective effect of sodium nitroprusside on the rat small intestine transplanted mucosa.

The intestinal mucosal epithelium is extremely susceptible to even brief periods of ischemia. Mucosal barrier damage, which is associated with ischemia/reperfusion (I/R) injury and consequently bacterial translocation, remains a major obstacle for clinically successful small bowel transplantation (SBT). Previous studies have demonstrated a protective effect of nitric oxide (NO) on other transplanted organs and NO mediated intestinal protection has also been reported in vitro. The aim of this study was to evaluate the effect of sodium nitroprusside (SNP), NO donor, on graft mucosal histology and molecular markers of function after SBT in rats. We used SNP in different period of heterotopic SBT rats. The groups consisted of SBT, pre-SNP group, and post-SNP group. Interestingly, the pre-SNP graft samples exhibited less damage compared to the SBT and post-SNP samples. In addition, mucosal samples from the pre-SNP group showed higher Na(+)-K(+)-ATPase activity and higher levels of laminin expression compared to the SBT and post-SNP samples. The findings of the present study reveal that SNP given before graft ischemia/reperfusion injury has a protective effect on mucosal histology and molecular markers of function in the transplanted small intestine.

p38 MAPK inhibition alleviates experimental acute pancreatitis in mice.

BACKGROUND: The mitogen-activated protein kinases (MAPKs) signaling pathway is involved in inflammatory process. However, the mechanism is not clear. The present study was to investigate the role of p38 MAPK in acute pancreatitis in mice. METHODS: Mice were divided into 4 groups: saline control; acute pancreatitis induced with repeated injections of cerulein; control plus p38 MAPK inhibitor SB203580; and acute pancreatitis plus SB203580. The pancreatic histology, pancreatic enzymes, cytokines, myeloperoxidase activity, p38 MAPK and heat shock protein (HSP) 60 and 70 were evaluated. RESULTS: Repeated injections of cerulein resulted in acute pancreatitis in mice, accompanying with the activation of p38 MAPK and overexpression of HSP60 and HSP70 in the pancreatic tissues. Treatment with SB203580 significantly inhibited the activation of p38 MAPK, and furthermore, inhibited the expression of HSP60 and HSP70 in the pancreas, the inflammatory cytokines in the serum, and myeloperoxidase activity in the lung. CONCLUSION: The p38 MAPK signaling pathway is involved in the regulation of inflammatory response and the expression of HSP60 and HSP70 in acute pancreatitis.

The dual effect of cannabinoid receptor-1 deficiency on the murine postoperative ileus.

INTRODUCTION: Intestinal inflammatory responses play a critical role in the pathogenesis of postoperative ileus (POI). As cannabinoid receptor-1 (CB1) is involved in inhibiting gastrointestinal (GI) motility and anti-inflammation, we aimed to explore its contribution to POI. METHODS: Experimental POI was induced in adult female CB1-deficient (CB1-/-) mice and wild-type littermates (C57BL/6N) by standardized small bowel manipulation. Twenty-four hours after surgery, GI transit was assessed by charcoal transport. FITC avidin, F4/80, and myeloperoxidase immunohistochemistry techniques were used to evaluate the inflammatory response in the muscularis of ileum and colon. Expressions of p38MAPK and its phosphorylated form (pp38) in the intestine were determined. Plasma levels of proinflammatory cytokines and chemokines were measured by ELISA as well. RESULTS: POI was characterized by decreased GI transit (p<0.01) and accompanied by a marked intestinal and systematic inflammatory response in wild-type and CB1-/- mice. Increased numbers of inflammatory cells, including macrophages, neutrophils, and mast cells were observed in the muscularis of ileum and colon (p<0.01, or p<0.05). Plasma levels of interleukin-6 (IL-6), cytokine-induced neutrophil chemoattractant-1 (CINC-1/KC), and monocyte chemoattractant protein-1 (MCP-1) were elevated (p<0.01, or p<0.05). Expression of p38 and pp38 increased in the intestine (p<0.01, or p<0.05). CB1-/- mice showed an increased inflammatory response during POI, especially the systemic inflammatory markers, such as IL-6, KC, CINC1, and pp38 expression were increased as compared to those in WT mice (p<0.05). CONCLUSIONS: Intestinal motility was inhibited during POI. In this condition, inhibition of motility did not seem to be altered by the absence of CB1 receptors, however, an increased inflammatory response was observed in CB1-/- mice. Hence, CB1 receptor activation rather than inhibition may reduce the inflammatory response in POI, which has a remote potential to relate into reduced inhibition of intestinal motility during POI.

Prognosis of patients with gastric cancer and solitary lymph node metastasis.

AIM: To investigate the relationship of solitary lymph node metastasis (SLNM) and age with patient survival in gastric cancer (GC). METHODS: The medical records databases of China's Beijing Cancer Hospital at the Peking University School of Oncology and Shanghai Tenth People's Hospital affiliated to Tongji University were searched retrospectively to identify patients with histologically proven GC and SLNM who underwent surgical resection between October 2003 and December 2012. Patients with distant metastasis or gastric stump carcinoma following resection for benign disease were excluded from the analysis. In total, 936 patients with GC + SLNM were selected for analysis and the recorded parameters of clinicopathological disease and follow-up (range: 13-2925 d) were collected. The Kaplan-Meier method was used to stratify patients by age (≤ 50 years-old, n = 198; 50-64 years-old, n = 321; ≥ 65 years-old, n = 446) and by metastatic lymph node ratio [MLR < 0.04 (1/25), n = 180; 0.04-0.06 (1/25-1/15), n = 687; ≥ 0.06 (1/15), n = 98] for 5-year survival analysis. The significance of intergroup differences between the survival curves was assessed by a log-rank test. RESULTS: The 5-year survival rate of the entire GC + SLNM patient population was 49.9%. Stratification analysis showed significant differences in survival time (post-operative days) according to age: ≤ 50 years-old: 950.7 ± 79.0 vs 50-64 years-old: 1697.8 ± 65.9 vs ≥ 65 years-old: 1996.2 ± 57.6, all P < 0.05. In addition, younger age (≤ 50 years-old) correlated significantly with mean survival time (r = 0.367, P < 0.001). Stratification analysis also indicated an inverse relationship between increasing MLR and shorter survival time: < 0.04: 52.8% and 0.04-0.06: 51.1% vs ≥ 0.06: 40.5%, P < 0.05. The patients with the shortest survival times and rates were younger and had a high MLR (≥ 0.06): ≤ 50 years-old: 496.4 ± 133.0 and 0.0% vs 50-65 years-old: 1180.9 ± 201.8 and 21.4% vs ≥ 65 years-old: 1538.4 ± 72.4 and 37.3%, all P < 0.05. The same significant trend in shorter survival times and rates for younger patients was seen with the mid-range MLR group (0.04-0.06), but the difference between the two older groups was not significant. No significant differences were found between the age groups of patients with MLR < 0.04. Assessment of clinicopathological parameters identified age group, Borrmann type, histological type and tumor depth as the most important predictors of the survival rates and times observed for this study population. CONCLUSION: GC patients below 51 years of age with MLR of SLNM above 0.06 have shorter life expectancy than their older counterparts.

Norcantharidin: a potential antiangiogenic agent for gallbladder cancers in vitro and in vivo.

Our objective was to explore the antiangiogenic activity of norcantharidin (NCTD) as an angiogenic inhibitor for gallbladder cancers. In vitro and in vivo experiments to determine the effects of NCTD on HUVECs, chicken CAM capillaries and gallbladder cancer xenograft angiogenesis in nude mice were respectively done. The MTT method was used to assay the cytotoxicity of NCTD on HUVECs. Immunofluorescence was used to evaluate HUVEC apoptosis. The scraping line method, matrigel invasion assay and tube formation assay were used to detect the migration, invasion and tube formation of HUVECs. A digital camera was used to observe chicken CAM capillaries. Experiments with NCTD in a xenograft model were used to observe the effect of NCTD on xenograft growth and survival of mice with xenografts. CD34 immunohistochemistry, flow cytometry and micro-MRA were used, respectively, to determine MVD, cell apoptosis and hemodynamic analysis of the xenografts. Immunohistochemistry and RT-PCR were used, respectively, to detect the expression of VEGF, Ang-2, TSP, TIMP-2 proteins/mRNAs of the xenografts. The xenograft MVD associated with tumor volume, the PCNA/apoptosis ratio and related-protein expression was evaluated simultaneously. We found that NCTD effectively inhibited the proliferation, migration, invasion and capillary-like tube formation of HUVECs in vitro; it reduced angiogenesis and directly destroyed the formed CAM capillaries in vivo. In the experiments in mice, NCTD not only inhibited significantly xenograft proliferation and growth, prolonged survival time of mice with xenografts, decreased the xenograft MVD and vascular perfusion, but also, similarly to ES, decreased significantly the expression of VEGF or Ang-2 protein/mRNA, increased the expression of TSP or TIMP-2 protein/mRNA. Moreover, the xenograft MVD was positively related with tumor volume, PCNA/apoptosis ratio, and VEGF or Ang-2 expression, respectively (all P<0.05), but negatively correlated with TSP or TIMP-2 expression (both P<0.05). These data showed that NCTD could serve as a potential antiangiogenic agent for gallbladder cancers.

Cytokines and irritable bowel syndrome: where do we stand?

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder, which presents with one or more gastrointestinal symptoms without any structural or organic abnormality. The etiology and pathophysiological mechanisms of IBS remain uncertain. Residual or reactivated inflammation at the molecular level is considered the underlying mechanism of post-infectious IBS. On the other hand, genetic variations in the immunological components of the body, including cytokine gene polymorphisms, are proposed as a potential mechanism of IBS even in patients without previous gastrointestinal infection. Several studies have suggested imbalanced cytokine signaling as an etiology for IBS. In this review, recent findings on cytokine profiles and cytokine gene polymorphisms in patients with IBS are described and the role of cytokines in animal models of IBS is discussed.

Distribution, function and physiological role of melatonin in the lower gut.

Melatonin is a hormone with endocrine, paracrine and autocrine actions. It is involved in the regulation of multiple functions, including the control of the gastrointestinal (GI) system under physiological and pathophysiological conditions. Since the gut contains at least 400 times more melatonin than the pineal gland, a review of the functional importance of melatonin in the gut seems useful, especially in the context of recent clinical trials. Melatonin exerts its physiological effects through specific membrane receptors, named melatonin-1 receptor (MT1), MT2 and MT3. These receptors can be found in the gut and their involvement in the regulation of GI motility, inflammation and pain has been reported in numerous basic and clinical studies. Stable levels of melatonin in the lower gut that are unchanged following a pinealectomy suggest local synthesis and, furthermore, implicate physiological importance of endogenous melatonin in the GI tract. Presently, only a small number of human studies report possible beneficial and also possible harmful effects of melatonin in case reports and clinical trials. These human studies include patients with lower GI diseases, especially patients with irritable bowel syndrome, inflammatory bowel disease and colorectal cancer. In this review, we summarize the presently available information on melatonin effects in the lower gut and discuss available in vitro and in vivo data. We furthermore aim to evaluate whether melatonin may be useful in future treatment of symptoms or diseases involving the lower gut.

Norcantharidin inhibits growth of human gallbladder carcinoma xenografted tumors in nude mice by inducing apoptosis and blocking the cell cycle in vivo.

BACKGROUND: Gallbladder carcinoma, a lethal malignant neoplasm with poor prognosis, has dismal results of surgical resection and chemoradiotherapy. We previously reported that norcantharidin (NCTD) is useful against growth, proliferation, and invasion of human gallbladder carcinoma GBC-SD cells in vitro. In this study, we further studied the inhibitory effect of NCTD on the growth of xenografted tumors of human gallbladder carcinoma in nude mice in vivo and the underlying mechanisms. METHODS: The tumor xenograft model of human gallbladder carcinoma in nude mice in vivo was established with subcutaneous GBC-SD cells. The experimental mice were randomly divided into control, 5-FU, NCTD, and NCTD+5-FU groups which were given different treatments. Tumor growth in terms of size, growth curve, and inhibitory rate was evaluated. Cell cycle, apoptosis, and morphological changes of the xenografted tumors were assessed by flow cytometry and light/electron microscopy. The expression of the cell cycle-related proteins cyclin-D1 and p27 as well as the apoptosis-related proteins Bcl-2, Bax, and survivin were determined by the streptavidin-biotin complex (SABC) method and RT-PCR. RESULTS: NCTD inhibited the growth of the xenografted tumors in a dose- and time-dependent manner. Tumor volume decreased (5.61+/-0.39 vs. 9.78+/-0.61 cm3, P=0.000) with an increased tumor inhibitory rate (42.63% vs. 0%, P=0.012) in the NTCD group compared with the control group. The apoptosis rate increased (15.08+/-1.49% vs. 5.49+/-0.59%, P=0.0001) along with a decreased percentage of cells in S phase (43.47+/-2.83% vs. 69.85+/-1.96%, P=0.0001) in the NTCD group compared with the control group. The morphological changes of apoptosis such as nuclear shrinkage, chromatin aggregation, chromosome condensation, and typical apoptosis bodies in the xenografted tumor cells induced by NCTD were observed by light and electron microscopy. The expression of cyclin-D1, Bcl-2 and survivin proteins/mRNAs decreased significantly, with increased expression of p27 and Bax proteins/mRNAs in the NCTD group compared with the control group. CONCLUSION: NCTD inhibits the growth of xenografted tumors of human gallbladder carcinoma in nude mice by inducing apoptosis and blocking the cell cycle in vivo.

[Effect of CD8(+)CD28(-) suppressor T cells induced by dendritic cell with major histocompatibility complex 1 expression RNA interference on immune tolerance in rat intestinal transplantation].

OBJECTIVE: To investigate the effect of CD8(+)CD28(-) suppressor T cells(Ts) induced by dendritic cell(DC) with major histocompatibility complex 1(MHC-1) expression RNA interference on immune tolerance in rat intestinal transplantation. METHODS: The expression level of CD8(+)CD28(-)Ts were successfully induced by DC with MHC-1 expression interfered by RNA interference technique under the stimulator of allograft antigen. Orthotopic intestinal transplantation was performed in 36 rats by modified three cuffs method. The recipients were randomly divided into three groups(12 rats in each group):group A was experimental group with CD8(+)CD28(-) Ts being administrated, mixed T cells were injected in group B, while in group C, NS were administrated. On the first day and the seventh day posttransplant, the 36 rats of the 3 groups were administrated through vena dorsalis penis respectively. Six rats were selected randomly from each group and the animals were sacrificed on the 14 th day postoperatively, serum levels of TGF-beta, IFN-gamma and the values of Na(+)-K(+)-ATPase activity of the intestinal graft were assayed and the intestinal pathologic morphology, intestinal allograft survival were observed concerning the remainders. RESULTS: On the 14 th day after operation, the expression levels of TGF-beta and IFN-gamma in group A were significantly up-regulated as compared with those in group B and group C(P<0.05). Na(+)-K(+)-ATPase activity in group A was(6.3+/-1.0) kU/g, much higher than the levels of group B(3.6+/-0.9)kU/g and group C(2.9+/-1.3) kU/g and the differences were significant(P<0.05). The data suggested preliminarily that pathological scores of intestinal graft in group A were lower than those in group B and group C. The survival time of the recipients in group A was 32.0 days, much longer than that in group B (17.5 days, P<0.05) and group C(21.0 days, P<0.05). CONCLUSION: CD8(+)CD28(-) Ts induced by DC with MHC-1 expression RNA interference can alleviate acute rejection and lead to immune tolerance in rat intestinal transplantation.

[Research of rat small intestinal mesentery lymphoid tissue stimulating allograft mixed lymphocyte reaction].

OBJECTIVE: To evaluate the effect of the small intestinal mesenteric lymphoid tissues stimulating mixed lymphocyte reaction with dendritic cells (DC) and peripheral blood monocyte cells (PBMC), and observe the changes of the MHC molecular expression on DC. METHODS: DC, PBMC and mixed lymphocyte were separated to culture from SD rats. Lymphoid tissue suspension was adopted from small intestinal mesentery of Wistar rats. In the mixed lymphocyte reaction (MLR), the cellular proliferation of small intestinal mesenteric lymphoid tissue antigen act on DC and PBMC was detected with cell counting of CCK-8 assay, the same assay used in small intestinal mesenteric lymphoid tissue antigen and ovalbumin (OVA) acting on DC. FACS analysis was performed after lymphoid tissue suspension stimulating DC to observe the MHC molecular expression. RESULTS: In the lymphoid tissue suspension, 91% of the cells was lymphocyte, others including granulocyte, plasmocyte, epithelium. The effect of stimulating mixed lymphocyte proliferation were higher in DC groups than in PBMC groups with the small intestinal mesenteric lymphoid tissue (P < 0.05). In the proportion of DC and mixed lymphocyte >or= 1:100 groups, the mixed lymphocyte proliferation were higher in the small intestinal mesenteric lymphoid tissues groups than in the OVA groups (P < 0.05). After stimulated by the small intestinal mesenteric lymphoid tissue, DC expressed higher MHC-I and -II molecules than control groups. CONCLUSIONS: The small intestinal mesenteric lymphoid tissue has high antigenicity; the antigen presenting ability of DC was much stronger than granulocytes; DC expresses high MHC-I and MHC-II molecules after stimulated by mixed lymphoid tissue suspension.