Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 193
Filtrar
1.
Am J Transplant ; 15(11): 2814-24, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26147452

RESUMEN

Epstein-Barr virus (EBV) is a γ-herpesvirus that is linked to the development of posttransplant lymphoproliferative disorder (PTLD) in solid organ recipients. We previously demonstrated that EBV(+) B cell lymphoma cell lines isolated from patients with PTLD produce human IL-10 as an autocrine growth factor. However, little is known regarding IL-10 regulation in B cells. Here we show that EBV infection markedly alters the expression of host B cell microRNA, a class of small noncoding RNA that is an important regulator of transcriptional and posttranscriptional gene expression. Gene arrays reveal unique microRNA profiles in EBV(+) B cell lymphoma lines from patients with PTLD, compared to normal B cells or in vitro generated EBV(+) lymphoblastoid cell lines. We show that microRNA-194 expression is uniquely suppressed in EBV(+) B cell lines from PTLD patients and that the 3'untranslated region of IL-10 is targeted by microRNA-194. Overexpression of microRNA-194 attenuates IL-10 production and increases apoptosis of EBV(+) B cell lymphoma lines. Together, these data indicate that EBV co-opts the host B cell microRNA network and specifically suppresses microRNA-194 to override control of IL-10 expression. Thus, modulation of microRNA-194 may constitute a novel approach to inhibiting proliferation of EBV(+) B cell lymphomas in PTLD.


Asunto(s)
Infecciones por Virus de Epstein-Barr/virología , Herpesvirus Humano 4/genética , Interleucina-10/metabolismo , Linfoma de Células B/patología , Trastornos Linfoproliferativos/virología , Linfocitos B/patología , Supervivencia Celular , Infecciones por Virus de Epstein-Barr/patología , Regulación Neoplásica de la Expresión Génica , Humanos , Linfoma de Células B/genética , Trastornos Linfoproliferativos/patología , MicroARNs/metabolismo , Trasplante de Órganos/efectos adversos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Valores de Referencia , Células Tumorales Cultivadas
2.
Transplant Proc ; 47(2): 233-9, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25769555

RESUMEN

BACKGROUND: Return to productive employment is often an important milestone in the recovery and rehabilitation process after liver transplantation (OLT). This literature review identifies factors associated with employment in patients who underwent OLT. METHODS: We searched PubMed for articles that addressed the various factors affecting employment after OLT. RESULTS: The studies demonstrated improvement in the quality of life and examined factors that predicted whether patients would return to work after OLT. Demographic variable associated with posttransplant employment included young age, male sex, college degree, Caucasian race, and pretransplant employment. Patients with alcohol-related liver disease had a significantly lower rate of employment than did those with other etiologies of liver disease. Recipients who were employed after transplantation had a significantly better posttransplant functional status than did those who were not employed. CONCLUSION: Economic pressures are increasing the expectation that patients who undergo successful OLT will return to work. Thus, transplant teams need to have a better understanding of posttransplant work outcomes for this vulnerable population, and greater attention must be paid to the full social rehabilitation of transplant recipients. Specific interventions for OLT recipients should be designed to evaluate and change their health perceptions and encourage their return to work.


Asunto(s)
Empleo , Trasplante de Hígado/rehabilitación , Reinserción al Trabajo , Adulto , Factores de Edad , Femenino , Humanos , Hepatopatías/etiología , Hepatopatías/cirugía , Trasplante de Hígado/métodos , Masculino , Persona de Mediana Edad , Calidad de Vida , Factores Sexuales , Factores Socioeconómicos
3.
Am J Transplant ; 13(8): 2035-43, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23841834

RESUMEN

Posttransplant lymphoproliferative disorder (PTLD) continues to be a devastating and potentially life-threatening complication in organ transplant recipients. PTLD is associated with EBV infection and can result in malignant B cell lymphomas. Here we demonstrate that the PI3K/Akt/mTOR pathway is highly activated in EBV+ B cell lymphoma lines derived from patients with PTLD. Treatment with the mTORC1 inhibitor Rapamycin (RAPA) partially inhibited the proliferation of EBV+ B cell lines. Resistance to RAPA treatment correlated with high levels of Akt phosphorylation. An mTORC1/2 inhibitor and a PI3K/mTOR dual inhibitor suppressed Akt phosphorylation and showed a greater anti-proliferative effect on EBV+ B lymphoma lines compared to RAPA. EBV+ B cell lymphoma lines expressed high levels of PI3Kδ. We demonstrate that PI3Kδ is responsible for Akt activation in EBV+ B cell lymphomas, and that selective inhibition of PI3Kδ by either siRNA, or a small molecule inhibitor, augmented the anti-proliferative effect of RAPA on EBV+ B cell lymphomas. These results suggest that PI3Kδ is a novel, potential therapeutic target for the treatment of EBV-associated PTLD and that combined blockade of PI3Kδ and mTOR provides increased efficacy in inhibiting proliferation of EBV+ B cell lymphomas.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Infecciones por Virus de Epstein-Barr/tratamiento farmacológico , Imidazoles/farmacología , Linfoma de Células B/tratamiento farmacológico , Trastornos Linfoproliferativos/complicaciones , Inhibidores de las Quinasa Fosfoinosítidos-3 , Quinolinas/farmacología , Sirolimus/farmacología , Western Blotting , Línea Celular Tumoral , Sinergismo Farmacológico , Infecciones por Virus de Epstein-Barr/etiología , Infecciones por Virus de Epstein-Barr/patología , Herpesvirus Humano 4/efectos de los fármacos , Humanos , Linfoma de Células B/etiología , Linfoma de Células B/patología , Trastornos Linfoproliferativos/patología , Diana Mecanicista del Complejo 1 de la Rapamicina , Diana Mecanicista del Complejo 2 de la Rapamicina , Complejos Multiproteicos/antagonistas & inhibidores , Complejos Multiproteicos/metabolismo , Trasplante de Órganos/efectos adversos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación/efectos de los fármacos , Complicaciones Posoperatorias , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/metabolismo
4.
Am J Transplant ; 13(4): 883-890, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23398911

RESUMEN

Posttransplant lymphoproliferative disorder (PTLD)-associated Epstein-Barr virus (EBV)+ B cell lymphomas are serious complications of solid organ and bone marrow transplantation. The EBV protein LMP2a, a B cell receptor (BCR) mimic, provides survival signals to virally infected cells through Syk tyrosine kinase. Therefore, we explored whether Syk inhibition is a viable therapeutic strategy for EBV-associated PTLD. We have shown that R406, the active metabolite of the Syk inhibitor fostamatinib, induces apoptosis and cell cycle arrest while decreasing downstream phosphatidylinositol-3'-kinase (PI3K)/Akt signaling in EBV+ B cell lymphoma PTLD lines in vitro. However, Syk inhibition did not inhibit or delay the in vivo growth of solid tumors established from EBV-infected B cell lines. Instead, we observed tumor growth in adjacent inguinal lymph nodes exclusively in fostamatinib-treated animals. In contrast, direct inhibition of PI3K/Akt significantly reduced tumor burden in a xenogeneic mouse model of PTLD without evidence of tumor growth in adjacent inguinal lymph nodes. Taken together, our data indicate that Syk activates PI3K/Akt signaling which is required for survival of EBV+ B cell lymphomas. PI3K/Akt signaling may be a promising therapeutic target for PTLD, and other EBV-associated malignancies.


Asunto(s)
Infecciones por Virus de Epstein-Barr/enzimología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Trastornos Linfoproliferativos/enzimología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Aminopiridinas , Animales , Apoptosis , Linfocitos B/metabolismo , Ciclo Celular , Línea Celular Tumoral , Activación Enzimática , Herpesvirus Humano 4 , Humanos , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Ganglios Linfáticos/patología , Linfoma de Células B/enzimología , Linfoma de Células B/virología , Trastornos Linfoproliferativos/virología , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Morfolinas , Oxazinas/farmacología , Complicaciones Posoperatorias , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Piridinas/farmacología , Pirimidinas , Transducción de Señal , Quinasa Syk , Trasplante Heterólogo
5.
Transplant Proc ; 42(7): 2676-8, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20832568

RESUMEN

Although outcomes after intestinal transplantation have steadily improved owing to advances in immunosuppressive therapy, operative techniques, and postoperative medical management, rejection of the intestinal allograft continues to be a major clinical problem and constitutes the primary reason for graft loss. Although the adaptive immune system has been the major focus of investigation regarding regulation of rejection of the intestinal allograft, the role of the innate immune system has recently become of increased interest. We hypothesized that microbial products of the microflora associated with the intestinal allograft may engage the Toll-like receptor pathway of the innate immune system to potentiate alloimmune responses and rejection of the allograft. To investigate this, we established a murine model for orthotopic intestinal transplantation and allograft rejection. Using this model, we show that the expression of Toll-like receptor 2 is increased 50-fold and the expression of Toll-like receptor 4 is increased 200-fold during rejection of the allograft. We then performed survival studies that showed increased survival of mice, which had the Toll-like receptor knocked out. These preliminary studies suggest an important role for in innate immune system in acute rejection of the small intestinal allografts, and as such represents an emerging and promising area of investigation.


Asunto(s)
Intestino Delgado/trasplante , Receptores Toll-Like/genética , Trasplante Homólogo/inmunología , Enfermedad Aguda , Animales , Regulación de la Expresión Génica , Rechazo de Injerto/genética , Rechazo de Injerto/patología , Intestino Delgado/patología , Ratones , Ratones Endogámicos C57BL , Modelos Animales , ARN Mensajero/genética , Receptor Toll-Like 2/genética , Receptor Toll-Like 4/genética , Trasplante Homólogo/patología
6.
Transplant Proc ; 42(2): 610-2, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20304205

RESUMEN

Outcomes after liver transplantation are outstanding; however, the limiting factor is the shortage of organs. Recently, the utilization of donors after cardiac death has been encouraged; however, such transplants are associated with a high complication rate, mainly a high incidence of biliary complications, particularly ischemic cholangiopahty, a serious complication that often leads to retransplantation. The second problem is the morbidity associated with the use of immunosuppressive drugs. In this manuscript, the current status of clinical protocols for induction of tolerance is briefly discussed. Furthermore, the future of research in transplantation will involve basic scientists and clinical scholars working in concert as has been developed at Stanford School of Medicine with the creation of the Institute for Immunity, Transplantation and Infection.


Asunto(s)
Trasplante de Hígado/métodos , Muerte , Tolerancia a Medicamentos , Humanos , Tolerancia Inmunológica , /tendencias , Inmunosupresores/uso terapéutico , Trasplante de Riñón/inmunología , Trasplante de Hígado/inmunología , Trasplante de Hígado/tendencias , Selección de Paciente , Periodo Posoperatorio , Investigación/tendencias , Donantes de Tejidos/provisión & distribución
7.
Transplant Proc ; 38(6): 1716-7, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16908259

RESUMEN

We report a 4-year experience of a new program in pediatric intestinal transplantation. Among 50 children referred for evaluation, 27 were listed for transplantation. Two children originally listed for combined liver/small bowel transplant were changed to isolated intestinal transplant as rehabilitation efforts resulted in full recovery of hepatic function. Eighteen children received 18 grafts: 12 liver/intestine, 5 isolated intestine, and 1 multivisceral. Mean age at transplant was 3.6 year with 75% of patients aged 0 to 2 years. Five listed children died while waiting and four were still on the list. Immunotherapy included antithymocyte globulin induction and tacrolimus, sirolimus, and prednisone maintenance. At 1 year, patient and graft survivals were 75% and 67%, respectively. For isolated intestine, 1 year survivals were 100% and 75%, while for combined liver/intestine, they were 71% for both. Enteral autonomy is 100% with total parenteral nutrition stopping by 35.8 days (mean). We had two patients develop posttransplant lymphoproliferative disorder and three, exfoliative rejection, one of whom recovered completely. In conclusion, our program in pediatric intestinal transplantation has become well established with a high proportion of smaller/younger children receiving grafts. Outcomes achieved levels expected based on The Intestinal Transplant Registry and UNOS criteria, which were better than expected for isolated intestinal transplants and achievement of enteral autonomy.


Asunto(s)
Intestinos/trasplante , Trasplante Homólogo/métodos , Sistema del Grupo Sanguíneo ABO , Incompatibilidad de Grupos Sanguíneos , California , Niño , Estudios de Seguimiento , Supervivencia de Injerto , Humanos , Estudios Retrospectivos , Análisis de Supervivencia , Factores de Tiempo , Trasplante Homólogo/inmunología , Trasplante Homólogo/mortalidad
8.
Pediatr Transplant ; 10(3): 304-10, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16677353

RESUMEN

Few studies have examined the prevalence, demographic variables and adverse consequences associated with non-adherence to immunosuppressive therapy in the adolescent liver transplant population. Our hypothesis is that a significant proportion of adolescent liver transplant recipients exhibit non-adherence to medical regimens and that certain demographic and medical condition-related characteristics can be identified as potential predictors of non-adherent behavior. Furthermore, non-adherence leads to a greater incidence of morbidity and mortality in this population as compared with the adherent subset of adolescent patients. We reviewed the charts of 97 patients from 1987 to 2002 who by December of 2002 had survived at least 1 yr post-transplant and were followed by the Pediatric Liver Transplant Service at any point during their adolescent period (ages of 12-21). Non-adherence was defined as documentation of a report of non-adherence by a patient, parent or healthcare provider that was recorded in the patient's legal medical record. Descriptive statistics were used to determine the prevalence, demographic variables and adverse outcomes associated with non-adherence to immunosuppressive therapy. Categorical variables were analyzed using the chi-square test or the Fisher exact probability test. The unpaired Student's t-test was used to analyze the continuous variable of age at transplant. Using the inclusion criteria, a total of 97 patients represented the study sample of whom 37 subjects (38.1%) were defined as non-adherent and 60 (61.8%) were adherent. Non-adherent subjects were more likely to be female, older (>18 yr) and from a single-parent household. There was no significant difference in immunosuppressive regimen between non-adherent and adherent patients. Non-adherence was significantly (p<0.025) associated with lower socioeconomic status (SES), older age at transplant (p<0.005, 95% CI: -5.5 to -.99, Student's t-test) and episodes of late acute rejection (p<.001). Non-adherence was also significantly associated with re-transplantation and death secondary to chronic rejection by the Fisher exact test (p<0.006 and p<0.05, respectively). Non-adherence to immunosuppressive therapy is a prevalent problem that is correlated with certain demographic and medical condition-related risk factors and more frequent adverse consequences in the adolescent liver transplant population. The greater incidence of late acute rejection, death and re-transplantation owing to chronic rejection in non-adherent patients suggests that non-adherence is significantly associated with an increased risk of morbidity and mortality. Further investigation to identify patients at greatest risk for non-adherence is necessary to design the most effective intervention to increase patient survival and well being.


Asunto(s)
Inmunosupresores/administración & dosificación , Hepatopatías/mortalidad , Hepatopatías/terapia , Trasplante de Hígado/métodos , Adolescente , Femenino , Humanos , Inmunosupresores/farmacología , Cooperación del Paciente , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
9.
Transplantation ; 73(3): 465-9, 2002 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-11884946

RESUMEN

INTRODUCTION: In liver transplant recipients with Epstein-Barr virus (EBV) disease, we reported a low rate of acute rejection after stopping or markedly lowering immunosuppression. This observation led to the hypothesis that EBV, as a means of viral persistence, induces expression of antiapoptotic factors and these factors, in turn, confer protection to the transplanted organ. Bcl-2, an antiapoptotic factor induced by EBV in various host cells, is not normally expressed in the liver. We questioned whether bcl-2 is expressed in the transplanted liver and whether its expression is modified by EBV. MATERIALS AND METHODS: Retrospective liver biopsy specimen from liver transplant patients diagnosed with EBV (n=12) were examined for the presence of bcl-2 by immunohistochemistry and compared with EBV (-) transplant (n=15), and nontransplant (n=13) livers. RESULTS: The most significant finding was the presence of endothelial bcl-2 expression in the majority of EBV (+) transplant samples examined (67%) and its relative absence in the other two groups (P<0.005). There was also bcl-2 expression in the hepatocytes and lymphocytes of the majority of transplant liver samples, irrespective of EBV status. DISCUSSION: We have identified a strong association between EBV infection and endothelial bcl-2 expression in transplant livers. We also found that transplantation, in itself, was associated with bcl-2 expression in the hepatocytes and lymphocytes of liver allografts.


Asunto(s)
Endotelio Vascular/química , Infecciones por Virus de Epstein-Barr/etiología , Trasplante de Hígado/efectos adversos , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Rechazo de Injerto , Hepatocitos/química , Humanos , Linfocitos/química , Estudios Retrospectivos , Trasplante Homólogo
10.
J Immunol ; 167(9): 5404-11, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11673559

RESUMEN

Post-transplant lymphoproliferative disorder is characterized by the outgrowth of EBV-infected B cell lymphomas in immunosuppressed transplant recipients. Using a panel of EBV-infected spontaneous lymphoblastoid cell lines (SLCL) derived from post-transplant lymphoproliferative disorder patients, we assessed the sensitivity of such lymphomas to Fas-mediated cell death. Treatment with either an agonist anti-Fas mAb or Fas ligand-expressing cells identifies two subsets of SLCL based on their sensitivity or resistance to Fas-driven apoptosis. Fas resistance in these cells cannot be attributed to reduced Fas expression or to mutations in the Fas molecule itself. In addition, all SLCL are sensitive to staurosporine-induced cell death, indicating that there is no global defect in apoptosis. Although all SLCL express comparable levels of Fas signaling molecules including Fas-associated death domain protein, caspase 8, and caspase 3, Fas-resistant SLCL exhibit a block in Fas-signaling before caspase 3 activation. In two SLCL, this block results in impaired assembly of the death-inducing signaling complex, resulting in reduced caspase 8 activation. In a third Fas-resistant SLCL, caspase 3 activation is hindered despite intact death-inducing signaling complex formation and caspase 8 activation. Whereas multiple mechanisms exist by which tumor cells can evade Fas-mediated apoptosis, these studies suggest that the proximal Fas-signaling pathway is impeded in Fas-resistant post-transplant lymphoproliferative disorder-associated EBV(+) B cell lymphomas.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Apoptosis , Herpesvirus Humano 4 , Péptidos y Proteínas de Señalización Intracelular , Linfoma de Células B/patología , Receptor fas/fisiología , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD , Proteínas Portadoras/análisis , Proteínas Portadoras/fisiología , Caspasa 3 , Caspasa 8 , Caspasa 9 , Caspasas/metabolismo , Línea Celular , Proteína de Dominio de Muerte Asociada a Fas , Humanos , Linfoma de Células B/virología , Trasplante de Órganos/efectos adversos , Estaurosporina/farmacología , Receptor fas/análisis
11.
Transplantation ; 71(12): 1827-34, 2001 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-11455265

RESUMEN

BACKGROUND: The requirement for cytotoxic T lymphocytes during allograft rejection is controversial. We previously demonstrated that CD8+ T cells are not necessary for allograft rejection or for the induction of apoptosis in rat small intestinal transplantation. In this study, we examined the mechanisms of apoptosis and rejection after liver transplantation in the absence of CD8+ T cells. METHODS: Either Lewis or dark agouti rat liver grafts were transplanted into Lewis recipients to create syngeneic and allogeneic combinations. CD8+ T cells were depleted in an additional allogeneic group by treatment with OX-8 mAb on day -1 and day 1 after liver transplant. RESULTS: Apoptosis and rejection were observed in both the CD8+ T cell-depleted allogeneic and allogeneic grafts by hematoxylin and eosin staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining, and radiolabeled-annexin V in vivo imaging. Granzyme B and FasL were expressed in all allogeneic transplants, including those depleted of CD8+ T cells, indicating that a mononuclear cell other than a CD8+ T cell can be the source of these molecules during allograft rejection. Activation of the caspase cascade was detected in all rejecting allografts. Caspases 3, 8, and 9 were activated at similar significantly elevated levels in both allogeneic and CD8+ T cell-depleted liver grafts. CONCLUSION: These data indicate that in the absence of CD8+ T cells an alternative pathway, associated with granzyme B and FasL expression and activation of the caspase cascade, can mediate apoptosis and graft rejection.


Asunto(s)
Apoptosis , Linfocitos T CD8-positivos/fisiología , Rechazo de Injerto/fisiopatología , Trasplante de Hígado , Animales , Apoptosis/fisiología , Linfocitos T CD8-positivos/patología , Caspasas/fisiología , Proteína Ligando Fas , Granzimas , Hígado/patología , Masculino , Glicoproteínas de Membrana/genética , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas Lew , Ratas Endogámicas , Serina Endopeptidasas/genética , Trasplante Homólogo
13.
Can J Anaesth ; 47(4): 334-7, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10764178

RESUMEN

PURPOSE: To report the anesthetic management of a patient with carcinoid tumour metastatic to the liver who presented for orthotopic liver transplantation. Anesthetic implications of metastatic carcinoid tumour on liver transplantation and the use of octreotide are discussed. CLINICAL FEATURES: A 51-yr-old woman with intestinal carcinoid tumour metastatic to the liver presented for orthotopic liver transplantation, a recent treatment option for patients with extensive hepatic carcinoid metastases and disabling symptoms unresponsive to conventional therapy. Despite continuous administration of the somatostatin analogue octreotide via a hepatic artery infusate pump, the patient suffered from daily break through symptoms, which included flushing, palpitations, paroxysmal hypertension, and dyspnea. The patient presented to the operating room with sinus tachycardia and severe arterial hypertension. Octreotide and phentolamine were used to prevent further mediator release and to control the paroxysmal hypertension. Midazolam, fentanyl, thiopental, succinylcholine, vecuronium, and isoflurane were used to induce and maintain anesthesia safely. An intravenous octreotide infusion was initiated after induction and continued throughout the case. Infrequent and non-threatening peaks in arterial blood pressure were readily treated with small intravenous doses of vasoactive drugs and octreotide. No other manifestations of the carcinoid syndrome occurred. The patient had an uneventful recovery and was discharged on postoperative day #6. CONCLUSION: The patient safely underwent orthotopic liver transplantation for treatment of symptomatic carcinoid tumour metastatic to the liver. The anesthetic management followed recent recommendations favouring the use of octreotide to prevent patients from becoming symptomatic. Outlined dosing regimen for octreotide provided satisfactory hemodynamic stability.


Asunto(s)
Anestesia por Inhalación , Tumor Carcinoide/cirugía , Neoplasias Hepáticas/cirugía , Trasplante de Hígado , Presión Sanguínea , Tumor Carcinoide/secundario , Femenino , Humanos , Hipertensión/prevención & control , Neoplasias Intestinales/patología , Complicaciones Intraoperatorias/prevención & control , Neoplasias Hepáticas/secundario , Persona de Mediana Edad , Octreótido/uso terapéutico
14.
Radiology ; 214(3): 795-800, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10715048

RESUMEN

PURPOSE: To assess the value of imaging rejection-induced apoptosis with technetium 99m and annexin V, a human protein-based radiopharmaceutical used in the diagnosis of acute rejection of a liver transplant, in a well-characterized rodent model of orthotopic liver transplantation. MATERIALS AND METHODS: 99mTc-radiolabeled annexin V was intravenously administered to six allografted (immunologically mismatched) and five isografted (immunologically matched) recipient rats on days 2, 4, and 7 after orthotopic liver transplantation. Animals were imaged 1 hour after injection of 0.2-2.0 mCi (8.0-74.0 MBq) of radiolabeled annexin V by use of clinical nuclear scintigraphic equipment. RESULTS: All animals in the allografted group demonstrated marked increases of 55% and 97% above the activity in the isografted group in hepatic uptake of annexin V on days 4 and 7, respectively. Severe acute rejection was histologically detected in all allografted livers on day 7. There was no histologic evidence of acute rejection in isografted animals. Dynamic hepatobiliary imaging with 99mTc and mebrofenin, an iminodiacetic acid derivative, demonstrated no correlation with the presence or absence of acute rejection or with annexin V uptake. CONCLUSION: Noninvasive imaging with radiolabeled annexin V is more sensitive and specific than imaging with 99mTc-mebrofenin in the diagnosis of acute rejection of a liver transplant.


Asunto(s)
Anexina A5 , Rechazo de Injerto/diagnóstico por imagen , Iminoácidos , Trasplante de Hígado , Compuestos de Organotecnecio , Radiofármacos , Agregado de Albúmina Marcado con Tecnecio Tc 99m , Enfermedad Aguda , Compuestos de Anilina , Animales , Glicina , Rechazo de Injerto/inmunología , Hígado/diagnóstico por imagen , Trasplante de Hígado/inmunología , Masculino , Cintigrafía , Ratas , Ratas Endogámicas Lew , Ratas Endogámicas , Sensibilidad y Especificidad
15.
Liver Transpl ; 6(1): 62-6, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10648579

RESUMEN

Pediatric allograft recipients are at increased risk for Epstein-Barr virus (EBV)-associated illnesses. The early identification and diagnosis of EBV-associated disorders is critical because disease progression can often be curtailed by modification of immunosuppression. We have previously shown that detection of EBV-specific sequences in the circulation by polymerase chain reaction (PCR) correlated well with the clinical symptoms of EBV infection. The purpose of the current study is to determine the significance of detecting EBV-specific sequences by PCR in asymptomatic pediatric liver transplant recipients. Peripheral-blood DNA was analyzed for the EBV genes, coding from the nuclear antigen 1 (EBNA-1) and the viral capsid antigen (gp220) by PCR. Samples from asymptomatic pediatric liver transplant recipients were analyzed from the immediate postoperative period and at 2- to 4-month intervals thereafter. We followed up 13 of these asymptomatic recipients who tested positive for EBV compared with 7 asymptomatic recipients who tested negative for EBV during the early posttransplantation period. Follow-up ranged from 1.5 to 4 years posttransplantation. Nine patients (69%) initially positive for EBV and asymptomatic ultimately developed symptoms of EBV infection, including fever, lymphadenopathy, rash, respiratory and gastrointestinal symptoms, and/or hepatitis. Five of these patients (56%) went on to develop posttransplant lymphoproliferative disorder based on histological examination of biopsied tissue and immunohistochemical identification of the EBV antigen/DNA in tissue. This is the first report suggesting that detection of EBV-specific sequences in the absence of symptoms may herald impending EBV-associated disorders. Thus, routine monitoring for circulating EBV sequences in asymptomatic recipients may be useful in the early identification of those at risk for developing EBV-associated disease and its ultimate prevention.


Asunto(s)
Infecciones por Virus de Epstein-Barr/diagnóstico , Herpesvirus Humano 4/aislamiento & purificación , Trasplante de Hígado , Complicaciones Posoperatorias/diagnóstico , Preescolar , ADN Viral/sangre , Infecciones por Virus de Epstein-Barr/epidemiología , Infecciones por Virus de Epstein-Barr/prevención & control , Femenino , Herpesvirus Humano 4/genética , Humanos , Trastornos Linfoproliferativos/diagnóstico , Trastornos Linfoproliferativos/epidemiología , Masculino , Reacción en Cadena de la Polimerasa , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Factores de Riesgo
16.
Pediatr Transplant ; 3(1): 22-6, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10359027

RESUMEN

In recent years, tacrolimus (FK506, TAC) has been increasingly utilized in liver transplantation. However, long-term risks and benefits as compared with conventional cyclosporin A (CsA) have not been fully elucidated. This retrospective study examined the potential outcome differences between TAC- and CsA-based immunosuppressive therapy in pediatric liver transplant recipients. From March 1988 to December 1996, 218 children (aged 0.1-17 yr) underwent 238 orthotopic liver transplantations; 58.7% (128/218) were under 2 yr of age at time of transplant. Initially, the maintenance immunosuppressive regimen consisted of CsA and prednisone, with antilymphocytic preparations (MALG, ATGAM, and OKT3) as induction therapy. Subsequently, TAC was used first as rescue therapy for steroid refractory rejection in CsA patients and then as maintenance immunosuppression. Fifty-seven out of the 147 CsA patients were converted to TAC for various reasons while 71 patients were placed on TAC as primary maintenance immunosuppression. 62.6 per cent (92/147) of liver recipients on CsA experienced at least one biopsy-proven acute rejection episode as compared to 50.7% (36/71) for TAC patients (p = 0.09); likewise, 34% (50/147) of CsA patients had more than one episode of rejection vs. 18.3% (13/71) for patients on TAC (p < 0.02). Rejection was the reason for conversion from CsA to TAC in 29 of 57 patients. Conversely, 19.0% (28/147) of CsA patients had to be switched to TAC for reasons not related to rejection (i.e. side-effects). The overall incidence of histologically proven chronic rejection was 7.8% (17/218). 10.9 per cent (16/147) of the children who were on CsA initially developed chronic rejection, which was significantly higher compared with one of 71 TAC recipients (p < 0.02). Of these 16 CsA patients with chronic rejection, 50.0% (8/16) underwent retransplantation for graft failure (mean interval from time of diagnosis of chronic rejection to re-transplant, 4.0 months; range 1-8 months), whereas the TAC patient has remained clinically stable with normal liver function tests after 23 months of follow-up. One year after liver transplantation, 72.8% (107/147) of CsA patients were still on steroids (mean dosage 0.20 mg/kg/d), as compared to 42.3% (30/71) of the TAC patients (mean dosage 0.14 mg/kg/d). The incidence of post-transplant lymphoproliferative disorder (PTLD) in Epstein-Barr virus (EBV)-infected patients was 2.2% (2/90), 7.0% (5/71) and 12.3% (7/57) for CsA, primary and TAC-converted groups, respectively. The overall incidence of PTLD was 6.9% (15/218). In summary, pediatric liver transplant recipients treated with TAC as primary maintenance immunosuppressive medication experienced significantly fewer episodes of rejection; especially chronic rejection, which lead to graft loss. However, the trade-off is a potential increased incidence of EBV-related PTLD in these patients.


Asunto(s)
Ciclosporina/uso terapéutico , Inmunosupresores/uso terapéutico , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/inmunología , Tacrolimus/uso terapéutico , Enfermedad Aguda , Adolescente , Niño , Preescolar , Enfermedad Crónica , Ciclosporina/inmunología , Rechazo de Injerto/etiología , Rechazo de Injerto/patología , Infecciones por Herpesviridae/etiología , Herpesvirus Humano 4 , Humanos , Inmunosupresores/inmunología , Lactante , Pruebas de Función Hepática , Estudios Retrospectivos , Tacrolimus/inmunología , Resultado del Tratamiento , Infecciones Tumorales por Virus/etiología
17.
J Gastroenterol Hepatol ; 14 Suppl: S28-31, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10382635

RESUMEN

Thirty consecutive, major liver resections performed with total vascular exclusion in both non-cirrhotic and cirrhotic patients were analysed retrospectively. The patients' ages ranged from 6 months to 80 years. Ten were Asians and five had cirrhosis associated with chronic hepatitis B or C. There was no perioperative death and the mean hospital stay was 6 days for adults and 9.2 days for children. The average vascular exclusion or warm ischaemia time was 25 min (range 10-55 min) and the average intraoperative blood volume given was 275 mL (range 0-3000 mL) packed red blood cells. Sixty per cent required no intraoperative blood transfusion. The mean total bilirubin and aspartate aminotransferase were 1.0 mg/dL (range 0.3-2.3 mg/dL) and 84 IU/L (range 14-306 IU/L) when measured prior to discharge at postoperative day 4-7. In our experience, total vascular exclusion is invaluable in major or difficult liver resections, especially lesions adjacent to the hepatic veins and vena cava. It is associated with a low blood transfusion requirement and a low incidence of complications. It further obviates the need for dissection of the porta hepatis and its associated risks. Total vascular exclusion time of 30 min appears to be well tolerated, even in patients with compensated cirrhosis.


Asunto(s)
Hepatectomía/métodos , Adulto , Anciano , Anciano de 80 o más Años , Preescolar , Hepatitis B Crónica/complicaciones , Hepatitis C Crónica/complicaciones , Humanos , Lactante , Cirrosis Hepática/cirugía , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios Retrospectivos
18.
J Gastroenterol Hepatol ; 14 Suppl: S37-41, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10382637

RESUMEN

Hepatocellular carcinoma is responsible for more than 1 million deaths per year worldwide and thus remains a challenging medical problem. It causes few or no symptoms and the tumour frequently reaches an enormous size by the time of diagnosis in countries where screening is seldom used. It is generally resistant to commercially available anti-neoplastic agents and radiation therapy. The principal treatment continues to be resection, either partial or complete, with liver transplantation. However, less than one-third of patients are surgical candidates for either resection or transplantation at the time of clinical presentation. This review will address the results observed following resection or transplantation for hepatocellular carcinoma.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Hepatectomía , Neoplasias Hepáticas/cirugía , Trasplante de Hígado , Humanos
19.
J Gastroenterol Hepatol ; 14 Suppl: S48-52, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10382639

RESUMEN

To assess whether Asian race is an independent variable affecting survival and hepatitis B virus (HBV) recurrence after liver transplantation, the results of 27 consecutive liver transplants performed between June 1994 and April 1997 for HBV cirrhosis were analysed. In the group of 13 Asians, 38% had associated hepatocellular carcinoma and 62% had positive hepatitis B virus early antigen (HBeAg) or elevated HBV-DNA before transplant. Prophylactic hepatitis B immunoglobulin (HBIG) was administered perioperatively and long term at 4-6 weekly interval. Four patients with elevated HBV-DNA received lamivudine before transplantation. The 3 year actuarial patient survival rate was 100% in both Asian and non-Asian patients. Twenty-six patients remained seronegative for hepatitis B virus surface antigen after transplantation. The incidence of post-transplant HBV recurrence was similar: 0% in Asians compared with 7% in non-Asians. There was no recurrence in the group of 12 patients who were HBV-DNA or HBeAg negative pretransplant.


Asunto(s)
Asiáticos , Hepatitis B/complicaciones , Cirrosis Hepática/cirugía , Trasplante de Hígado/mortalidad , Adolescente , Adulto , Carcinoma Hepatocelular/complicaciones , Antígenos e de la Hepatitis B/análisis , Humanos , Inmunización Pasiva , Inmunoglobulinas/inmunología , Terapia de Inmunosupresión , Lamivudine/uso terapéutico , Cirrosis Hepática/etiología , Neoplasias Hepáticas/complicaciones , Metilprednisolona/uso terapéutico , Persona de Mediana Edad , Recurrencia , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Tasa de Supervivencia
20.
Arch Surg ; 134(1): 25-9, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9927126

RESUMEN

OBJECTIVE: To evaluate the effect of intraoperative transfusion of red blood cells (RBCs) on patient and graft survival. DESIGN: A retrospective study. SETTING: A tertiary care referral center. PATIENTS: Between January 1, 1992, and December 31, 1994, medical records from 225 adult patients who underwent primary liver transplantations were analyzed. RESULTS: Overall patient survival was 90% at 1 year and 86% at 3 years, while graft survival was 89% at 1 year and 85% at 3 years. The following factors were associated with patient and graft survival: age, sex, medical condition at the time of transplantation, and intraoperative transfusion of RBCs. When these factors were subjected to a multivariate analysis, all were independently associated with survival. Fifty-four recipients (24%) underwent transplantation without intraoperative transfusion of RBCs, while 171 recipients (76%) received at least 1 U of RBCs intraoperatively. Recipients who did not receive transfusion of RBCs had higher patient and graft survival rates than patients who did receive RBCs. By multivariate analysis, transplantation without intraoperative transfusion of RBCs no longer remained statistically significant, and only sex and the patient's medical condition were independently associated with patient and graft survival. Patient and graft survival decreased if 5 or more U were transfused, but transfusion of 5 or more U was not independently associated with survival by multivariate analysis. CONCLUSIONS: Increased transfusion requirement for RBCs was independently associated with patient and graft survival. While transplantation without transfusion of intraoperative RBCs was associated with superior patient and graft survival, these effects were overridden by patient sex and medical condition at the time of transplantation.


Asunto(s)
Transfusión de Eritrocitos , Cuidados Intraoperatorios , Trasplante de Hígado , Femenino , Supervivencia de Injerto , Humanos , Trasplante de Hígado/mortalidad , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...