Perioperative infliximab application has marginal effects on ischemia-reperfusion injury in experimental small bowel transplantation in rats.

PURPOSE: Ischemia-reperfusion injury leads to impaired smooth muscle function and inflammatory reactions after intestinal transplantation. In previous studies, infliximab has been shown to effectively protect allogenic intestinal grafts in the early phase after transplantation with resulting improved contractility. This study was designed to reveal protective effects of infliximab on ischemia-reperfusion injury in isogenic transplantation. METHODS: Isogenic, orthotopic small bowel transplantation was performed in Lewis rats (3 h cold ischemia). Five groups were defined: non-transplanted animals with no treatment (group 1), isogenic transplanted animals with vehicle treatment (groups 2/3) or with infliximab treatment (5 mg/kg body weight intravenously, directly after reperfusion; groups 4/5). The treated animals were sacrificed after 3 (group 2/4) or 24 h (group 3/5). Histological and immunohistochemical analysis, TUNEL staining, real-time RT-PCR, and contractility measurements in a standard organ bath were used for determination of ischemia-reperfusion injury. RESULTS: All transplanted animals showed reduced smooth muscle function, while no significant advantage of infliximab treatment was observed. Reduced infiltration of neutrophils was noted in the early phase in animals treated with infliximab. The structural integrity of the bowel and infiltration of ED1-positive monocytes and macrophages did not improve with infliximab treatment. At 3 h after reperfusion, mRNA expression of interleukin (IL)-6, TNF-α, IL-10, and iNOS and MCP-1 displayed increased activation in the infliximab group. CONCLUSION: The protective effects of infliximab in the early phase after experimental small bowel transplantation seem to be unrelated to ischemia-reperfusion injury. The promising effects in allogenic transplantation indicate the need for further experiments with infliximab as complementary treatment under standard immunosuppressive therapy. Further experiments should focus on additional infliximab treatment in the setting of acute rejection.

Influence of immunosuppression on alloresponse, inflammation and contractile function of graft after intestinal transplantation.

In small bowel transplantation (SBTx), graft manipulation, ischemia/reperfusion injury and acute rejection initiate a severe cellular and molecular inflammatory response in the muscularis propria leading to impaired motility of the graft. This study examined and compared the effect of tacrolimus and sirolimus on inflammation in graft muscularis. After allogeneic orthotopic SBTx, recipient rats were treated with tacrolimus or sirolimus. Tacrolimus and sirolimus attenuated neutrophilic, macrophage and T-cell infiltration in graft muscularis, which was associated with reduced apoptotic cell death. Nonspecific inflammatory mediators (IL-6, MCP-1) and T-cell activation markers (IL-2, IFN-gamma) were highly upregulated in allogeneic control graft muscularis 24 h and 7 days after SBTx, and tacrolimus and sirolimus significantly suppressed upregulation of these mediators. In vitro organ bath method demonstrated a severe decrease in graft smooth muscle contractility in allogeneic control (22% of normal control). Correlating with attenuated upregulation of iNOS, tacrolimus and sirolimus treatment significantly improved contractility (64% and 72%, respectively). Although sirolimus reduced cellular and molecular inflammatory response more efficiently after 24 h, contrary tacrolimus prevented acute rejection more efficiently. In conclusion, tacrolimus and sirolimus attenuate cellular and molecular inflammatory response in graft muscularis and subsequent dysmotility of the graft after allogeneic SBTx.

Perioperative infliximab application ameliorates acute rejection associated inflammation after intestinal transplantation.

As we have shown in the past, acute rejection-related TNF-α upregulation in resident macrophages in the tunica muscularis after small bowel transplantation (SBTx) results in local amplification of inflammation, decisively contributing to graft dysmotility. Therefore, the aim of this study is to investigate the effectiveness of the chimeric-monoclonal-anti-TNF-α antibody infliximab as perioperative single shot treatment addressing inflammatory processes during acute rejection early after transplantation. Orthotopic, isogenic and allogenic SBTx was performed in rats (BN-Lewis/BN-BN) with infliximab treatment. Vehicle and IV-immunoglobulin-treated animals served as controls. Animals were sacrificed after 24 and 168 h. Leukocyte infiltration was investigated in muscularis whole mounts by immunohistochemistry, mediator mRNA expression by Real-Time-RT-PCR, apoptosis by TUNEL and smooth muscle contractility in a standard organ bath. Both, infliximab and Sandoglobulin® revealed antiinflammatory effects. Infliximab resulted in significantly less leukocyte infiltration compared to allogenic controls and IV-immunoglobulin, which was accompanied by lower gene expression of MCP-1 (24 h), IFN-γ (168 h) and infiltration of CD8-positive cells. Smooth muscle contractility improved significantly after 24 h compared to all controls in infliximab treated animals accompanied by lower iNOS expression. Perioperative treatment with infliximab is a possible pharmaceutical approach to overcome graft dysmotility early after SBTx.

Efficiency of adenovirus-mediated gene transduction in heart grafts in rats.

AIM: We determined the characteristics of transgene expression of heart grafts following ex vivo gene transfer using an adenovirus vector. Transgene expression was assessed periodically in the same animals by a non-invasive bioimaging system. METHODS: Rat heterotopic heart transplantation was performed in a syngenic combination. We infused 1 x 10(9) plaque-forming units of adenovirus vectors containing firefly luciferase gene into the heart graft via the coronary artery, with preservation at 4 degrees C and transplanted into the cervix of the recipient. Transgene expression was periodically visualized and quantified by a noninvasive bioimaging system without sacrificing experimental animals. RESULTS: Transgene expression in the graft peaked at day 7 and then fell gradually. Transgene expression was also observed in the recipient liver. CONCLUSIONS: We have determined the time course of transgene expression in the heart graft. This constitutes important information about ex vivo gene therapy for heart grafts.

Findings of pelvic musculature and efficacy of laparoscopic muscle stimulator in laparoscopy-assisted anorectal pull-through for high imperforate anus.

BACKGROUND: Laparoscopic findings of levator muscle and the efficacy of laparoscopic muscle stimulator (LMS) in infants with high imperforate anus have not been reported. METHODS: Twelve patients underwent laparoscopically assisted anorectoplasty for high imperforate anus. Following laparoscopic dissection of the distal rectum and division of the fistula, levator muscles in the pelvic floor were stimulated with a 5-mm-diameter LMS. Dilatation was done by inserting a guidewire and balloon catheter through the center of the levator muscle sling and muscle complex. Rectal pull-through and anastomosis between the rectum and anus were successfully completed. RESULTS: LMS showed good contraction of levator muscles and enhanced accurate midline placement of pull-through rectum. LMS was particularly useful in observing weak muscles in infants with rectovesical fistula. CONCLUSIONS: Laparoscopy and LMS offer excellent visualization of the pelvic musculature and precise tract of rectal pull-through. Fecal continence will be assessed by long-term follow-up.

Comparison of noradrenergic and serotonergic antidepressants in reducing immobility time in the tail suspension test.

We examined the effects of two noradrenergic tricyclic antidepressants and two selective serotonin re-uptake inhibitors in the tail suspension test, with a suspension period of 30 min instead of the usual 10 min. Within the first 10 min, desipramine, nortriptyline and fluvoxamine significantly reduced the duration of immobility. Whereas desipramine and nortriptyline were also efficacious in the rest of the test period, fluvoxamine was not. Fluoxetine showed no significant effect throughout the study period. These results suggest that a prolonged tail suspension test results in functional changes in the noradrenergic and serotonergic systems and alters the sensitivity to antidepressants.