RESUMO
Abdominal closure is a complex surgical problem in intestinal transplant recipients with loss of abdominal domain, as graft exposure results in profound morbidity. Although intraoperative coverage techniques have been described, this is the first report of preoperative abdominal wall augmentation using tissue expanders in patients awaiting intestinal transplantation. We report on five patients who received a total of twelve tissue expanders as a means to increase abdominal surface area. Each patient had a compromised abdominal wall (multiple prior operations, enterocutaneous fistulae, subcutaneous abscesses, stomas) with loss of domain and was identified as high risk for an open abdomen post-transplant. Cross-sectional imaging and dimensional analysis were performed to quantify the effect of the expanders on total abdominal and intraperitoneal cavity volumes. The overall mean increase in total abdominal volume was 958 cm(3) with a mean expander volume of 896.5 cc. Two expanders were removed in the first patient due to infection, but after protocol modification, there were no further infections. Three patients eventually underwent small bowel transplantation with complete graft coverage. In our preliminary experience, abdominal tissue expander placement is a safe, feasible, and well-tolerated method to increase subcutaneous domain and facilitate graft coverage in patients undergoing intestinal transplantation.
Assuntos
Parede Abdominal/cirurgia , Antibioticoprofilaxia/métodos , Intestinos/transplante , Dispositivos para Expansão de Tecidos , Vancomicina/uso terapêutico , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Reovirus induces apoptosis in cultured cells and in vivo. In cell culture models, apoptosis is contingent upon a mechanism involving reovirus-induced activation of transcription factor NF-kappaB complexes containing p50 and p65/RelA subunits. To explore the in vivo role of NF-kappaB in this process, we tested the capacity of reovirus to induce apoptosis in mice lacking a functional nfkb1/p50 gene. The genetic defect had no apparent effect on reovirus replication in the intestine or dissemination to secondary sites of infection. In comparison to what was observed in wild-type controls, apoptosis was significantly diminished in the CNS of p50-null mice following reovirus infection. In sharp contrast, the loss of p50 was associated with massive reovirus-induced apoptosis and uncontrolled reovirus replication in the heart. Levels of IFN-beta mRNA were markedly increased in the hearts of wild-type animals but not p50-null animals infected with reovirus. Treatment of p50-null mice with IFN-beta substantially diminished reovirus replication and apoptosis, which suggests that IFN-beta induction by NF-kappaB protects against reovirus-induced myocarditis. These findings reveal an organ-specific role for NF-kappaB in the regulation of reovirus-induced apoptosis, which modulates encephalitis and myocarditis associated with reovirus infection.
Assuntos
Apoptose/fisiologia , Subunidade p50 de NF-kappa B/metabolismo , Infecções por Reoviridae , Reoviridae/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/citologia , Encéfalo/metabolismo , Encéfalo/virologia , Linhagem Celular , Coração/virologia , Marcação In Situ das Extremidades Cortadas , Interferon beta/genética , Interferon beta/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/citologia , Intestinos/virologia , Camundongos , Camundongos Knockout , Miocardite/patologia , Miocardite/virologia , Miocárdio/citologia , Miocárdio/metabolismo , Miocárdio/patologia , Subunidade p50 de NF-kappa B/genética , Reoviridae/genética , Infecções por Reoviridae/metabolismo , Infecções por Reoviridae/patologia , Replicação ViralRESUMO
BACKGROUND: Although renal dysfunction (RD) has been commonly associated with poor outcome after other solid organ transplants, it has not been studied in detail after intestinal transplantation (ITx). Here we provide a detailed analysis of renal function after ITx, and identify predictors of post-ITx RD. METHODS: A retrospective analysis of patients undergoing ITx from 1991 to 2006 was performed. For each patient, the estimated glomerular filtration rate (eGFR) was compared with the normal GFR for age and gender to obtain the percent of normal eGFR. Chi-square analysis and log-rank tests were used to identify categorical variables associated with RD (eGFR <75% of normal) and to determine if RD was predictive of post-ITx survival. RESULTS: Sixty-eight transplantations were performed in 62 patients. Overall patient survival at 1 and 5 years was 78% and 56%, respectively. Renal dysfunction was observed in 16% of patients post-ITx. The most frequent predictors of post-ITx RD were preoperative eGFR less than 75% of normal, pre-ITx location in the intensive care unit, and high-dose tacrolimus immunotherapy. An eGFR less than 75% of normal at days 7, 28, and 365 was predictive of poor patient survival (P<0.05). CONCLUSIONS: This study provides the first detailed analysis of renal function after ITx. We identified specific risk factors for the development of RD in the first year post-ITx and found a significant association of RD with decreased long-term survival. Given the strong correlation of RD with poor outcome, preserving renal function may be key to improving long-term outcomes in ITx recipients.
Assuntos
Intestinos/transplante , Nefropatias/etiologia , Rim/fisiopatologia , Transplante de Órgãos/efeitos adversos , Adulto , Criança , Cuidados Críticos , Feminino , Taxa de Filtração Glomerular , Humanos , Imunossupressores/efeitos adversos , Estimativa de Kaplan-Meier , Nefropatias/mortalidade , Nefropatias/fisiopatologia , Modelos Logísticos , Masculino , Transplante de Órgãos/mortalidade , Estudos Retrospectivos , Fatores de Risco , Tacrolimo/efeitos adversos , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Antithymocyte therapy, specifically antithymocyte globulin (ATG; Thymoglobulin), is increasingly being used in organ transplantation to reduce allograft rejection. The T-lymphocyte has been purported to also play a role in ischemia and reperfusion injury (IRI); however, it has not been well studied. Our aim is to determine if ATG treatment impacts murine intestinal IRI. METHODS: Under anesthesia, male C57BL6 mice underwent 100 minutes of warm intestinal IRI by clamping the superior mesenteric artery. The treatment group received rabbit anti-murine ATG (10 mg/kg) intraperitoneally 6 hours before IRI. Separate survival and analysis groups were performed. Intestinal tissue was procured at 4 and 24 hours after IRI. Tissue analysis included hematoxylin-eosin staining, CD3, CD4, and CD8 immunostaining, myeloperoxidase assay (MPO), quantitative real-time polymerase chain reaction studies, and Western blot. RESULTS: ATG treatment led to marked improvement in 7-day survival and a reduction in tissue injury by histology. MPO was also reduced, and immunostaining confirmed a significant reduction in CD3(+), CD4(+), and CD8(+) infiltrating cells in the treatment group. Quantitative real-time polymerase chain reaction analysis revealed the decreased expression of tumor necrosis factor-α, interferon-inducible protein 10, monocyte chemotactic protein-1, interferon-γ, interleukin-2, and increased production of interleukins -13 and -10 in the treatment group. Western blot analysis revealed decreased caspase-3 and increased signal transducer and activator of transcription 6 levels in the ATG-treated group. CONCLUSION: This study is the first to show that ATG treatment ameliorates intestinal IRI. Treatment with ATG leads to reduced local infiltration by T-lymphocytes, with fewer inflammatory and chemotactic programs and less apoptosis. Treatment also is associated with a T(H)2-type cytokine switch. These novel findings suggest that T-lymphocytes represent important mediators of intestinal IRI and that ATG therapies may be beneficial in the prevention of IRI.
Assuntos
Soro Antilinfocitário/uso terapêutico , Enteropatias/prevenção & controle , Intestinos/irrigação sanguínea , Traumatismo por Reperfusão/prevenção & controle , Animais , Antígenos CD/metabolismo , Western Blotting , Enteropatias/patologia , Mucosa Intestinal/metabolismo , Intestinos/patologia , Intestinos/transplante , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peroxidase/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Traumatismo por Reperfusão/patologiaRESUMO
BACKGROUND: Ischemia-reperfusion (I/R) injury is a major factor leading to intestinal dysfunction or graft loss after intestinal surgery or transplantation. This study investigated the cytoprotective effects and putative mechanisms of interleukin (IL)-13 after intestinal I/R injury in the mouse. METHODS: Mouse warm intestinal I/R injury induced by clamping the superior mesenteric artery for 100 min with tissue analysis at 4 and 24 hr after reperfusion. Treated animals received intravenous recombinant murine IL-13 (rIL-13) and anti-IL-13 antibody, whereas controls received saline. RESULTS: rIL-13 administration markedly prolonged animal survival (100% vs. 50% in saline controls) and resulted in near normal histopathological architecture. rIL-13 treatment also significantly decreased myeloperoxidase activity. Mice conditioned with rIL-13 had a markedly depressed Toll-like receptor-4 expression and increased the expression of Stat6, antioxidant hemeoxygenase-1, and antiapoptotic A20, Bcl-2/Bcl-xl, compared with that of controls. Unlike in controls, the expression of mRNA coding for IL-2/interferon-γ, and interferon-γ-inducible protein (IP)-10/monocyte chemotactic protein-1 remained depressed, whereas that of IL-13/IL-4 reciprocally increased in the mice treated with rIL-13. Administration of anti-IL13 antibody alone or in combination with rIL-13 resulted in outcomes similar to that seen in controls. CONCLUSIONS: This study demonstrates for the first time that IL-13 plays a protective role in intestinal warm I/R injury and a critical role in the regulation of Stat6 and Toll-like receptor-4 signaling. The administration of IL-13 exerts cytoprotective effects in this model by regulating innate and adaptive immunity while the removal of IL-13 using antibody therapy abrogates this effect.
Assuntos
Imunidade Adaptativa , Imunidade Inata , Interleucina-13/farmacologia , Intestinos/irrigação sanguínea , Traumatismo por Reperfusão/prevenção & controle , Animais , Citoproteção , Interleucina-13/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peroxidase/metabolismo , Proteínas Recombinantes/farmacologia , Fator de Transcrição STAT6/fisiologia , Receptor 4 Toll-Like/fisiologiaRESUMO
Reovirus infection activates NF-kappaB, which leads to programmed cell death in cultured cells and in the murine central nervous system. However, little is known about how NF-kappaB elicits this cellular response. To identify host genes activated by NF-kappaB following reovirus infection, we used HeLa cells engineered to express a degradation-resistant mutant of IkappaBalpha (mIkappaBalpha) under the control of an inducible promoter. Induction of mIkappaBalpha inhibited the activation of NF-kappaB and blocked the expression of NF-kappaB-responsive genes. RNA extracted from infected and uninfected cells was used in high-density oligonucleotide microarrays to examine the expression of constitutively activated genes and reovirus-stimulated genes in the presence and absence of an intact NF-kappaB signaling axis. Comparison of the microarray profiles revealed that the expression of 176 genes was significantly altered in the presence of mIkappaBalpha. Of these genes, 64 were constitutive and not regulated by reovirus, and 112 were induced in response to reovirus infection. NF-kappaB-regulated genes could be grouped into four distinct gene clusters that were temporally regulated. Gene ontology analysis identified biological processes that were significantly overrepresented in the reovirus-induced genes under NF-kappaB control. These processes include the antiviral innate immune response, cell proliferation, response to DNA damage, and taxis. Comparison with previously identified NF-kappaB-dependent gene networks induced by other stimuli, including respiratory syncytial virus, Epstein-Barr virus, tumor necrosis factor alpha, and heart disease, revealed a number of common components, including CCL5/RANTES, CXCL1/GRO-alpha, TNFAIP3/A20, and interleukin-6. Together, these results suggest a genetic program for reovirus-induced apoptosis involving NF-kappaB-directed expression of cellular genes that activate death signaling pathways in infected cells.
Assuntos
Regulação da Expressão Gênica , Orthoreovirus Mamífero 3/patogenicidade , NF-kappa B/metabolismo , Animais , Perfilação da Expressão Gênica , Células HeLa , Humanos , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Células L , Camundongos , Mutação , Inibidor de NF-kappaB alfa , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Infecções por Reoviridae/genética , Infecções por Reoviridae/imunologia , Infecções por Reoviridae/metabolismoRESUMO
Reovirus attachment to cells is mediated by the binding of viral attachment protein sigma 1 to junctional adhesion molecule 1 (JAM1). The crystal structure of the extracellular region of human JAM1 (hJAM1) reveals two concatenated Ig-type domains with a pronounced bend at the domain interface. Two hJAM1 molecules form a dimer that is stabilized by extensive ionic and hydrophobic contacts between the N-terminal domains. This dimeric arrangement is similar to that observed previously in the murine homolog of JAM1, indicating physiologic relevance. However, differences in the dimeric structures of hJAM1 and murine JAM1 suggest that the interface is dynamic, perhaps as a result of its ionic nature. We demonstrate that hJAM1, but not the related proteins hJAM2 and hJAM3, serves as a reovirus receptor, which provides insight into sites in hJAM1 that likely interact with sigma 1. In addition, we present evidence that the previously reported structural homology between sigma 1 and the adenovirus attachment protein, fiber, also extends to their respective receptors, which form similar dimeric structures. Because both receptors are located at regions of cell-cell contact, this similarity suggests that reovirus and adenovirus use conserved mechanisms of entry and pathways of infection.