Protective effect of L-arginine preconditioning on ischemia and reperfusion injury associated with rat small bowel transplantation

AIM: To investigate the protective effect and possible mechanism of L-arginine preconditioning on ischemia and reperfusion injury associated with small bowel transplantation (SBT). METHODS: Male inbred Wistar rats weighting between 180 and 250 g were used as donors and recipients in the study. Heterotopic rat SBT was performed according to the techniques of Li and Wu. During the experiment, intestinal grafts were preserved in 4℃ Ringer's solution for 8 h before being transplanted. Animals were divided into three groups. In group 1, donors received intravenous L-arginine (50 mg/kg, 1 mL) injection 90 min before graft harvesting. However, donors in control group were given normal saline (NS) instead. In group 3, six rats were used as sham-operated control. Specimens were taken from intestinal grafts 15 min after reperfusion. Histological grading, tissue malondialdehyde (MDA) and myeloperoxidase (MPO) levels were assessed. The graft survival of each group was monitored daily until 14 d after transplantation. RESULTS: Levels of MDA and MPO in intestine of sham-operated rats were 2.0±0.22 mmol/g and 0.66±0.105 U/g. Eight hours of cold preservation followed by 15 min of reperfusion resulted in significant increases in tissue MDA and MPO levels. Pretreatment with L-arginine before graft harvesting resulted in lower enhancement of tissue levels of MDA and MPO and the differences were significant (4.71±1.02 mmol/g vs 8.02±3.49 mmol/g, 1.03±0.095 U/g vs 1.53±0.068 U/g, P<0.05). Besides, animals in L-arginine pretreated group had better histological structures and higher 2-wk graft survival rates comparing with that in NS treated group (3.3±0.52 vs 6±0.1, 0/6 vs 6/6, P<0.05 or 0.01). CONCLUSION: L-arginine preconditioning attenuates ischemia and reperfusion injury in the rat SBT model, which was due to antioxidant activities partially.     

亲体小肠移植术后并发症的内镜与病理监测

目的探讨亲体小肠移植术后并发症的发生情况与防治。方法实施1例母亲为供体的小肠移植。通过内镜与病理检查对移植小肠并发症进行监测。结果移植手术过程顺利，受体生命体征稳定。术后第37天内镜和活检病理发现急性排斥反应，术后第65天活检病理发现巨细胞病毒感染。经激素冲击、OKT3抗排斥治疗，结合抗病毒治疗，病情得到控制，至发稿时已存活18个月。结论小肠移植患者容易发生急性排斥反应和感染等并发症，加强监护和采用内镜活检及病理检查可以及时发现隐匿的病情，控制病情，提高存活率。     

小鼠小肠移植血管吻合技术的改进

目的　改进血管吻合技术,提高小鼠小肠移植血管吻合的成功率。方法　BAL B/ c小鼠小肠移植模型6 0例,每组2 0例,分别采用改良连续缝合方法(A组)、间断缝合方法(B组)及每针均收紧的连续缝合方法(C组) ,将小鼠供体腹主动脉和门静脉分别与受体腹主动脉和下腔静脉行端侧吻合。结果　三组总手术时间:A组(15 2±4 6 )分钟,B组(190±5 1)分钟,C组(183±38)分钟,A组与B、C两组相比,P <0 .0 5 ,差异有显著性。血管并发症:A组5例(2 5 % ) ,B组13例(6 5 % ) ,C组12例(6 0 % ) ,A组与B、C两组相比,P <0 .0 5 ,差异有显著性。总手术成功2 6例(43.3% ) ,其中A组13例(6 5 % ) ,B组6例(30 % ) ,C组7例(35 % ) ,A组与B、C两组相比,P<0 .0 5 ,差异有显著性。结论　改良连续血管吻合方法手术时间短,血管并发症少,手术成功率高。     

Capsule enteroscopy in small bowel transplantation

BACKGROUND: Enteroscopy plays a key role in the post-operative monitoring of patients with small bowel transplantation for the early detection of post-transplant complications and for the assessment of the graft's integrity. Routine surveillance enteroscopies (trans-stomal terminal ileoscopy or jejunoscopy) are invasive, may be unsafe in frail patients, and only allow incomplete exploration of the transplanted graft, which may be unsatisfactory. since the distribution of the lesions is often patchy or segmental. AIMS. To evaluate the potential of capsule enteroscopy, a new, minimally invasive technique which allows complete exploration of the small bowel. in small bowel transplant recipients. METHODS: Five small bowel transplanted patients underwent capsule enteroscopy with the GIVEN endoscopy system. The results of capsule enteroscopy were compared with those of trans-stomal ileoscopy. RESULTS: Capsule enteroscopy was better tolerated than ileoscopy and good quality images of the small bowel were obtained in four patients. The terminal ileum was normal both on ileoscopy and capsule enteroscopy. Mucosal changes in segments not reached by ileoscopy were detected by capsule enteroscopy in three of four patients. CONCLUSIONS: Capsule enteroscopy is better tolerated than ileoscopy, allows complete exploration of the transplanted graft and can detect mucosal changes in segments not reached by ileoscopy.     

Formation of microchimerism in rat small bowel transplantation by splenocyte infusion

AIM: To investigate the effect of donor splenocyte infusion combined with cyclosporine A (CsA) on rejection of rat small bowel transplantation (SBT). METHODS: Male Sprague-Dawley (SD) rats and female Wistar rats weighing 230-270 g were used as donors and recipients respectively in the study. Heterotopic small bowel transplantation was performed. The rats were divided into three groups: group one receiving allotransplantation (SD rarr Wistar), group two receiving allotransplantation (SD rarr Wistar) + donor splenocyte infusion, group three receiving allotransplantation (SD rarr Wistar) + donor splenocyte infusion + CsA followed by CsA 10 mg/kg per day after transplantation, in which recipient Wistar rats were injected with 2 x 10(8) SD splenocytes 28 d before transplantation, and treated with CsA after transplantation. Finally, the specific DNA fragment of donor Y chromosome was detected in recipient peripheral blood and skin by PCR. The survival time after small bowel transplantation was observed. Gross and histopathological examinations were performed. RESULTS: The survival time after small bowel trans-plantation was 7.1 +/- 1.2 d in group 1, 18.4 +/- 3.6 d in group 2 and 31.5 +/- 3.1 d in group 3. The survival time was significant longer (P < 0.01) in group 3 than in groups 1 and 2. The gross and histopathological examination showed that the rejection degree in group 3 was lower than that in groups 1 and 2. CONCLUSION: Donor splenocyte infusion combined with CsA decreases remarkably the rejection and prolongs the survival time after rat small bowel transplantation.     

Formation of microchimerism in rat small bowel transplantation by spienocyte infusion

AIM: To investigate the effect of donor splenocyte infusion combined with cyclosporine A (CsA) on rejection of rat small bowel transplantation (SBT). METHODS: Male Sprague-Dawley (SD) rats and female Wistar rats weighing 230-270 g were used as donors and recipients respectively in the study. Heterotopic small bowel transplantation was performed. The rats were divided into three groups: group one receiving allotransplantation (SD→Wistar), group two receiving allotransplantation (SD→Wistar) donor splenocyte infusion, group three receiving allotransplantation (SD→Wistar) donor splenocyte infusion CsA followed by CsA 10 mg/kg per day after transplantation, in which recipient Wistar rats were injected with 2×108 SD splenocytes 28 d before transplantation, and treated with CsA after transplantation. Finally, the specific DNA fragment of donor Y chromosome was detected in recipient peripheral blood and skin by PCR. The survival time after small bowel transplantation was observed. Gross and histopathological examinations were performed. RESULTS: The survival time after small bowel transplantation was 7.1±1.2 d in group 1, 18.4±3.6 d in group 2 and 31.5±3.1 d in group 3. The survival time was significant longer (P < 0.01) in group 3 than in groups 1 and 2. The gross and histopathological examination showed that the rejection degree in group 3 was lower than that in groups 1 and 2. CONCLUSION: Donor splenocyte infusion combined with CsA decreases remarkably the rejection and prolongs the survival time after rat small bowel transplantation.     

Neurophysiological study of the effect of combined kidney and pancreas transplantation on diabetic neuropathy: a 2-year follow-up evaluation

Previous study have reported a significant improvement of peripheral neuropathy following combined pancreas and kidney transplantation attributed to improvement of blood glucose control by some authors and to elimination of uraemia by others. To asses the specific role of uraemia and hyperglycaemia in neuropathy, 16 diabetic uraemic patients with combined pancreas and kidney transplantation were compared to 9 diabetic patients with a renal graft only. Neurophysiological studies of peripheral neuropathy included ulnar and deep peroneal nerve motor conduction velocity, median and sural nerve sensory conduction velocity were performed at baseline and 1 and 2 years after transplantation. One year after transplantation mean nerve conduction velocity significantly improved in both groups. However, changes were statistically significant in the kidney-pancreas group only. At the 2 year follow-up nerve conduction velocity had increased further in the pancreas-kidney group only. These data suggest that improvement of nerve conduction velocity following pancreas and kidney transplantation is predominantly due to the long-term euglycaemic state.     

胰腺移植的研究进展

胰腺移植是治疗终末期糖尿病的可行性选择.40来,外科手术技术及免疫抑制的进步,显著促进了胰腺移植适应证的增加和移植物存活率的提高.胰腺移植能替代患者每天的胰岛素注射,提高生活质量,同时也需要复杂的手术操作和终生的免疫抑制治疗.因此发展创伤更小的内分泌替代治疗方法(胰岛移植)的研究一直在进行.本文概括地介绍了胰腺移植的适...     

Diagnosis and treatment of acute rejection in the first case of human living-related small bowel transplantation with a long-term survival in China

AIM: To report the comprehensive diagnosis and treatment of acute rejection in the first case of living-related small bowel transplantation with a long-term survival in China. METHODS: A 18-year-old boy with short gut syndrome underwent living-related small bowel transplantation, with the graft taken from his father (44-year old). A segment of 150-cm distal small bowel was resected from the donor. The ileo-colic artery and vein from the donor were anastomosed to the infrarenal aorta and vena cava of the recipient respectively. The intestinal continuity was restored with an end-to-end anastomosis between the recipient jejunum and donor ileum, and the distal end was fistulized. FK506, MMF and prednisone were initially used for post-transplant immunosuppression. Endoscopic observation and mucosal biopsies of the graft were carried out through the terminal ileum enterostomy; serum was collected to detect the levels of IL-2R, IL-4, IL-6 and IL-8. The change of the graft secretion and absorption was observed. RESULTS: Acute rejection was diagnosed promptly and cured. The patient was in good health, 5 years after livingrelated small bowel transplantation. CONCLUSION: The correct diagnosis and treatment of acute rejection are the key to the long-term survival after living-related small bowel transplantation.     

Fatal cytomegalovirus necrotising enteritis in a small bowel transplantation adult recipient with low pp65 antigenaemia levels

Although advances in immunosuppressive therapy have led to increased survival of solid organ transplantation recipients, it is well established that current protocols have been associated with an increased risk of developing tissue-invasive infections. In particular, cytomegalovirus still represents an important cause of morbidity. We report a case of cytomegalovirus infection involving the graft ileum with documented necrotising enteritis that developed after small bowel transplantation. The patient, a 56-year-old Caucasian female with a postsurgery short bowel syndrome, underwent a small bowel transplantation. Immunosuppression was maintained by combination of tacrolimus, steroids and daclizumab. Both the donor and the recipient were serologically negative for cytomegalovirus IgG. Nevertheless, ganciclovir prophylaxis was given for 21 days after surgery, as standard procedure. On hospital day 174, routine pp65 antigenaemia resulted positive (14/200,000 peripheral blood leukocytes). The patient was asymptomatic and preemptive ganciclovir therapy was instituted. In the following 3 days, due to a cytomegalovirus antigenaemia increase, ganciclovir was changed to foscarnet with subsequent virological response (7/200,000 peripheral blood leukocytes, on day 181). Two days later, the patient complained of acute abdominal pain and she underwent surgery for the diagnosis. Since the intraoperative findings consisted of a diffuse acute purulent peritonitis, the intestinal graft, together with native rectum, was removed. Biopsy specimens showed evidence of tissue-invasive cytomegalovirus infection. Postsurgery, the patient developed septic shock and died on day 198 as a consequence of multiple organ failure.     

甘露醇对大鼠小肠移植缺血再灌注损伤的保护作用

目的:探讨甘露醇对大鼠小肠移植缺血再灌注(ischemia and reperfusion,I/R)损伤的保护作用及其作用机制.方法:建立大鼠小肠移植I/R损伤模型.雄性SD大鼠随机分为假手术组、I/R组和甘露醇处理组.对I/R损伤后不同时间(0.5,1,1.5 h)的小肠标本进行组织病理学观察并检测小肠组织中超氧化物歧化酶(SOD,U/mgprot)和丙二醛(MDA,nmol/mgprot)的含量.结果:不同时间点I/R组小肠绒毛高度和黏膜厚度低于假手术组(P<0.01)和甘露醇处理组(P<0.05).不同时间点I/R组(16.24±4.56,18.50±2.89.19.42±2.21)MDA水平高于假手术组(10.26±1.72,P<0.01)和甘露醇处理组(11.24±1.51,14.03±3.12,16.06±3.62;P<0.05);而SOD水平低于假手术组和甘露醇处理组(398.36±18.81,363.16±16.29,325.66±14.58 vs 447.97±16.94;422.30±17.41,385.09±19.11,346.15±14.10;P<0.01或P<0.05).结论:甘露醇可通过清除氧自由基的方式对移植小肠缺血再灌注损伤起到保护作用.     

Mesenchymal stem cell therapy in patients with small bowel transplantation: Single center experience

AIM: To study the effects of mesenchymal stem cell (MSC) therapy on the prevention of acute rejection and graft vs host disease following small bowel transplantation.METHODS: In our transplantation center, 6 isolated intestinal transplants have been performed with MSC therapy since 2009. The primary reasons for transplants were short gut syndrome caused by surgical intestine resection for superior mesenteric artery thrombosis (n = 4), Crohn’s disease (n = 1) and intestinal aganglionosis (n = 1). Two of the patients were children. At the time of reperfusion, the first dose of MSCs cultured from the patient’s bone marrow was passed into the transplanted intestinal artery at a dose of 1000000 cells/kg. The second and third doses of MSCs were given directly into the mesenteric artery through the arterial anastomosis using an angiography catheter on day 15 and 30 post-transplant.RESULTS: The median follow-up for these patients was 10.6 mo (min: 2 mo-max: 30 mo). Three of the patients developed severe acute rejection. One of these patients did not respond to bolus steroid therapy. Although the other two patients did respond to anti-rejection treatment, they developed severe fungal and bacterial infections. All of these patients died in the 2^nd and 3^rd months post-transplant due to sepsis. The remaining patients who did not have acute rejection had good quality of life with no complications observed during the follow-up period. In addition, their intestinal grafts were functioning properly in the 13^th, 25^th and 30^th month post-transplant. The patients who survived did not encounter any problems related to MSC transplantation.CONCLUSION: Although this is a small case series and not a randomized study, it is our opinion that small bowel transplantation is an effective treatment for intestinal failure, and MSC therapy may help to prevent acute rejection and graft vs host disease following intestinal transplantation.     

Effect of pancreas transplantation on life expectancy, kidney function and quality of life in uraemic Type 1 (insulin-dependent) diabetic patients

The aim of our study was to evaluate the effects of haemodialysis, kidney transplantation and simultaneous kidney and pancreas transplantation on survival of diabetic subjects and on kidney function. 40 Type 1 (insulin-dependent) diabetic patients received a kidney transplantation: in 31 cases the kidney was transplanted simultaneously to a pancreas graft from the same donor (KP group), while in 9 cases the pancreas was not available (K group). 44 uraemic Type 1(insulin-dependent) diabetic patients on dialysis and in waiting list for kidney transplantation, constituted the control group (HD group). Patient survival rate 1, 3 and 5 years following transplantation was better in KP group (93%, 89%, 89%, respectively) than in K group (88%, 88%, 73%, respectively) and in HD group (88%, 62%, 51%, respectively). Kidney graft survival at 1, 3 and 5 years post-transplant was better in KP group (93%, 72%, 72%, respectively) than in K group (76%, 61%, 31%, respectively). 1 year after transplantation, patients of the KP group who had lost the pancreas for technical reasons (thrombosis) were included in the K group so as to evaluate the effect of the transplanted pancreas on long-term patient and kidney survival. Patient survival rate in the KP group (17 patients) at 2 and 4 years was 100%, while at the same intervals it was 78% in the K group (13 patients). Kidney graft function rate at 2 and 4 years was 93% in the KP group (17 grafts) and 54% and 27% respectively in the K group (14 grafts). Evaluation of quality of life in patients receiving a kidney and pancreas transplantation showed an improvement in psychological well-being, when compared to patients receiving a kidney transplantation alone. Physical well-being was similar in patients transplanted with kidney and pancreas or with kidney alone.     

High incidence of carpal tunnel syndrome in diabetic patients after combined pancreas and kidney transplantation

Fifty-eight patients with long-standing type 1 (insulin-dependent) diabetes were studied prospectively after combined pancreas and kidney transplantation for a mean observation period of 47.9 months (range 17–116 months). Thirty-three per cent of these patients (19/58) developed carpal tunnel syndrome after a mean interval of 1.7 years (range 3 months–5 years). This rate is about twice that in type 1 diabetic patients. The manifestation of carpal tunnel syndrome was not significantly associated with worsening of diabetic polyneuropathy or with deterioration of kidney or pancreas function. In all but one patient symptoms improved without surgical intervention. This study suggests that patients after combined pancreas and kidney transplantation have an increased risk of carpal tunnel syndrome for which the etiology and pathophysiology are unknown. In most patients no surgical intervention is necessary.     

Liver transplantation: Current status and challenges

Great progress has been made in the field of liver transplantation over the past two decades. This progress, however, also brings up the next set of challenges: First, organ shortage remains a major limitation, and accounts for a large proportion of wait list mortality. While living donation has successfully increased the total number of liver transplants done in Asian countries, the total number of such transplants has been stagnant in the western hemisphere. As such, there has been a significant effort over the past decade to increase the existing deceased donor pool. This effort has resulted in a greater use of liver allografts following donation after cardiac death(DCD) along with marginal and extended criteria donors. Improved understanding of the pathophysiology of liver allografts procured after circulatory arrest has not only resulted in better selection and management of DCD donors, but has also helped in the development of mechanical perfusion strategies. Early outcomes demonstrating the clinical applicability of both hypothermic and normothermic perfusion and its potential to impact patient survival and allograft function have generated much interest. Second, long-term outcomes of liver transplant recipients have not improved significantly, as recipients continue to succumb to complications of long-term immunosuppression, such as infection, malignancy and renal failure. Furthermore, recent evidence suggests that chronic immune-mediated injury to the liver may also impact graft function.     

小肠移植中急性抗体介导排斥反应的病理学

目的:观察重度急性抗体介导排斥反应(antibody-mediated rejection,AMR)的病理形态学改变,回顾分析相关文献,为小肠移植急性AMR的诊断总结经验.方法:切除的失功能移植肠经10%中性福尔马林固定,石蜡包埋,4?m切片并行HE染色.详细观察移植物中肠壁各层及肠系膜内组织中主要的病理形态学改变,分级评价急性排斥反应及血管病变,并进行C4d免疫组织化学染色.结果:移植物内各级血管广泛受累,包括肠壁及肠系膜内各级血管.受累血管的改变以肠壁浆膜下层内的小血管及动静脉的滋养血管最为显著,主要表现为小血管壁的纤维素性坏死和/或血管内血栓形成,受累血管周围组织中性粒细胞浸润,红细胞漏出,组织水肿,部分病变血管周围伴有纤维素性坏死.免疫组织化学染色可见病变血管内膜C4d沉积.小肠黏膜固有层内血管显著扩张伴淤血,偶见血栓形成,肠黏膜隐窝上皮细胞正常,未见急性排斥反应.结论:血管壁的纤维素性坏死及血管内血栓形成是重度急性AMR的主要病理学改变.病变可以广泛累及移植物内各级血管;小肠黏膜内血管的病变可能不代表最严重的病变;临床早期确诊AMR的发生不能单纯依赖小肠黏膜活检.     

小肠间质瘤的临床特征、诊断与治疗措施

近年来,随着对小肠疾病检出方法的不断完善,对小肠疾病的诊断有了进一步的认识;本文通过比较各种用于小肠肿瘤检出的方法(包括消化道造影、腹部CT、DSA、内窥镜检查、腹部核素扫描、PET等),基本确立小肠间质瘤的诊断流程。再结合临床特征、病理学、以及免疫组化检查,最终确诊小肠间质瘤。手术切除是目前最有效的治疗方法,对于高度怀疑小肠间质瘤的患者,应尽早手术探查;此外,对于不可切除的、复发的、已有转移的间质瘤患者可用伊马替尼治疗。     

大鼠肝肠联合移植后肝对小肠的免疫保护作用

目的：建立大鼠肝肠联合整体移植模型,研究移植肝是否对移植小肠具有免疫保护作用．方法：选用封闭群SD大鼠和近交系Wistar大鼠．实验分5组：同基因小肠移植组、同基因肝移植组、异基因小肠移植组、异基因肝移植组、肝肠联合移植组．同基因移植供受体均为Wistar大鼠,异基因小肠移植、肝移植和肝肠联合移植供受体分别选用SD和Wistar大鼠．肝肠联合移植在切取移植物后,利用供体胸段下腔静脉在门静脉侧壁建立一袖套,并安置套管．受体手术时,将此门静脉侧壁袖套与受体门静脉残端套管法吻合．供体肠系膜上动脉与受体右肾动脉吻合．免疫保护作用通过术后5,7,14 d从各组随机取出4只大鼠的移植物普通病理检查及细胞凋亡检测评估．结果：肝肠联合移植模型建立手术成功率73．3%(22/30)．同基因移植组术后仅表现为缺血-再灌注损伤所致的轻度组织损伤及炎症反应,移植物细胞凋亡数逐渐减少．异基因移植术后均出现急性排斥、移植物细胞凋亡数递增,并且较同基因移植多,差别有显著性．小肠移植术后5,7,14 d分别表现为轻度、中度和重度排斥．而肝肠联合移植的小肠移植物术后5,7,14 d分别表现为轻度、轻度和中度排斥,且14 d时小肠细胞凋亡数较异基因小肠移植组少,差别具有显著性(16．9±4．3 vs 20．5±6．3,P＜0．05)．术后各时间点异基因肝移植和肝肠联合移植的移植肝排斥反应严重程度相同,细胞凋亡数比较无显著差异．结论：此法建立大鼠肝肠联合移植模型可行．肝肠联合移植时肝对小肠具有免役保护作用．     

Donor-derived bone marrow transfusion produces mixed chimerism and promotes a Th2 shift in Th1/Th2 balance in rat heterotopic small bowel transplantation

Background and aim

In this study, we investigated immunomodulatory effects of donor-derived bone marrow transfusion in rat heterotopic small bowel transplantation.

Methods

Rat heterotopic segmental small bowel transplantation models (male Brown Norway to female Lewis) were established. The recipients were randomly divided into control group (pute small bowel transplantation), tacrolimus group (small bowel transplantation plus oral tacrolimus) and small bowel transplantation plus oral tacrolimus and intraportal infusion of donor-derived bone marrow cells group. We investigated the survival time, graft pathologic injuries and rejection grade by haematoxylin–eosin staining, serum IL-2 and IL-10 detection by enzyme labelled immunosorbent assay after small bowel transplantation. The recipients mixed chimerism were observed by detecting sex-determining region of Y chromosome gene in blood, liver, spleen and intestine by using real-time polymerase chain reaction and fluorescence in situ hybridization.

Results

Bone marrow cells group showed a superior survival than the other groups, accompanied by milder pathologic injuries and lower rejection grade, decreasing serum IL-2 and increasing serum IL-10. The recipient chimerism rate in blood, liver, spleen and intestine in bone marrow cells group was significantly higher than the other groups.

Conclusion

Transfusion of donor-derived bone marrow cells via portal vein induces mixed chimerism in rats after small bowel transplantation, which may promote a Th2 shift in Th1/Th2 balance and facilitate the induction of immune tolerance.