RESUMEN

Different factors have been reported to influence islet isolation outcome, but their importance varies between studies and are hampered by the small sample sizes in most studies. The purpose of this study was to perform a systematic review to assess the impact of donor-, pancreas-, and isolation-related variables on successful human islet isolation outcome. PubMed, Embase, and Web of Science were searched electronically in April 2009. All studies reporting on donor-, pancreas-, and isolation-related factors relating to prepurification and postpurification islet isolation yield and proportion of successful islet isolations were selected. Seventy-four retrospective studies had sufficient data and were included in the analyses. Higher pre- and postpurification islet yields and a higher proportion of successful islet isolations were obtained when pancreata were preserved with the two-layer method rather than University of Wisconsin solution in donors with shorter cold ischemia times (CITs) [1 h longer CIT resulted in an average decline of prepurification and postpurification yields and proportion of successful isolations of 59 islet equivalents (IEQs)/g, 54 IEQs/g, and 21%, respectively]. Higher prepurification yields and higher percentage of successful islet isolations were found in younger donors with higher body mass index. Lower yields were found in donation after brain death donors compared to donation after cardiac death donors. Higher postpurification yields were found for isolation with Serva collagenase. This review identified donor-, pancreas-, and isolation-related factors that influence islet isolation yield. Standardized reports of these factors in all future studies may improve the power and identify additional factors and thereby contribute to improving islet isolation yield.

Asunto(s)

Islotes Pancreáticos/citología , Páncreas/citología , Donantes de Tejidos , Anciano , Humanos , Trasplante de Islotes Pancreáticos/métodos , Persona de Mediana Edad

RESUMEN

BACKGROUND: Many donor and recipient factors are known to affect pancreas graft survival. However, their relative importance in explaining differences in graft survival is unknown. Purpose of this study was to retrospectively evaluate the impact of donor and recipient factors on pancreas graft survival, and compare their contribution in explaining graft survival differences. MATERIAL/METHODS: Patient records of all 170 pancreas transplantations (158 Simultaneous Pancreas-Kidney; 12 Pancreas-after-kidney) in the period 1997-2008 were reviewed retrospectively to assess recipient factors before/during transplantation, and to assess graft survival. Eurotransplant reports were reviewed to assess donor factors. RESULTS: Death-censored 1-year graft survival was 88.4% and 82.3% at 3 years. Several factors significantly influenced graft survival: female recipient gender (Hazard Ratio (HR) 2.81[1.10-7.14]), enteric graft drainage (HR 2.85[1.15-7.05]), and donor-recipient match on BMI (HR 2.46[1.01-6.02]). None of the donor factors significantly affected survival. Similar results were found for 1-year survival, except for enteric graft drainage and donor-recipient BMI matching. In total, donor factors explained 3.6% and recipient factors 10.0% of the variance in graft survival. Donor factors were more important for 1-year survival (3.1%), but still less important than recipient factors which explained 6.4%. CONCLUSIONS: Recipient factors are more important in explaining differences in pancreas graft survival than donor factors.

Asunto(s)

Diabetes Mellitus Tipo 1/cirugía , Supervivencia de Injerto , Trasplante de Páncreas , Donantes de Tejidos , Adulto , Índice de Masa Corporal , Selección de Donante , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Trasplante de Riñón , Masculino , Persona de Mediana Edad , Países Bajos , Atención Perioperativa , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores Sexuales , Donantes de Tejidos/estadística & datos numéricos , Resultado del Tratamiento

RESUMEN

Variable islet yields in porcine islet isolation may be caused by the collagen substrate within the pancreas. The aim of the present study was to determine the total amount and distribution of collagen within porcine pancreata and their relationship to islet isolation outcome. A total of 64 juvenile and 76 adult porcine pancreata of eight purebred breeds were histologically examined. The amount of collagen was quantitatively assessed in tissue samples stained with Sirius Red. Collagen distribution was semi-quantitatively determined by assessing the presence of collagen in the endocrine-exocrine interface and within the islet, in tissue samples stained with Sirius Red and anti-insulin. Islet isolation was performed in 58 pancreata of the adult group. Total collagen content and islet encapsulation ranged widely in both adult and juvenile pigs. However, the majority of islets in adult and juvenile pigs had no or only a limited collagen capsule. The difference in collagen content between adult and juvenile pigs could not be explained by age. Furthermore, no differences between adult and juvenile pigs were found in islet encapsulation or the amount of intra-islet collagen. In adult pigs, no significant relationships were found between obtained islet yield and total collagen content, islet encapsulation or amount of collagen within the islet. Considering the limitations in experimental design (staining method) and study material, isolation outcome does not seem to be affected by the total collagen content or collagen distribution. The influence of other matrix elements and collagen subtypes should be investigated.

Asunto(s)

Separación Celular/métodos , Colágeno/análisis , Islotes Pancreáticos/citología , Páncreas/química , Páncreas/citología , Animales , Composición de Medicamentos , Humanos , Trasplante de Islotes Pancreáticos , Porcinos

RESUMEN

To evaluate whether further improvement in porcine islet xenotransplantation is feasible, a number of questions were addressed. Earlier we showed significant improvement in the nude mouse of the porcine islets by selection through long-term culture. Now these islets were tested in the stringent pig-to-rat model. Islets were isolated from adult pigs, cultured for 1.5-3 weeks and transplanted to rats. Possible rejection mechanisms were assessed by interference of the cellular response with cyclosporine A (CsA), blocking macrophages with gadolinium chloride (GdCl), and suppressing the humoral response with cyclophosphamide. Modifications in graft size and condition were analyzed. Untreated control recipients showed primary nonfunction (PNF). CsA treatment could fully overcome PNF and resulted in graft survival from 10 to over 134 days. Rejection was the main cause of function loss. Although rejection could not be prevented by intensifying the induction therapy, increased maintenance immunosuppression effectively blocked rejection, albeit at the expense of toxicity. Blocking the humoral response was ineffective; all grafts showed PNF. In contrast, depletion of macrophages fully prevented PNF. Combination of GdCl and CsA gave no additional effect, and grafts were rejected between 57 and 162 days. Generally, graft survivals were similar to those reported in the literature; however, long-term cultured islets required much less maintenance immunosuppression. Cessation of graft function was not always due to rejection; in some cases "islet exhaustion" was found, possibly caused by discrepancy between the graft size and the rapidly growing recipient. Neither the presence of damaged islet tissue in the graft nor the size of the graft exerted any influence on graft survival. On rejection, no real infiltration of the graft was seen; destruction gradually processed from the outside. The good functional capability of the cultured islets was illustrated by disappearance of the clinical symptoms and increase in body weight, which almost doubled in the long-term survivors.

Asunto(s)

Supervivencia de Injerto , Terapia de Inmunosupresión , Trasplante de Islotes Pancreáticos , Animales , Antiinflamatorios/uso terapéutico , Ciclofosfamida/farmacología , Ciclofosfamida/uso terapéutico , Ciclosporina/uso terapéutico , Diabetes Mellitus Experimental/terapia , Quimioterapia Combinada , Gadolinio/uso terapéutico , Rechazo de Injerto/prevención & control , Supervivencia de Injerto/efectos de los fármacos , Inmunosupresores/uso terapéutico , Masculino , Modelos Animales , Ratas , Ratas Endogámicas Lew , Porcinos , Trasplante Heterólogo

RESUMEN

BACKGROUND: A remarkable change in porcine islet morphology was observed after infusion of the pancreas with collagenase. The aim of the present study was to quantify these morphological changes and to assess whether these changes were due to the volume expansion caused by the collagenase entering the islet or the result of its digestive effects. METHODS: This study was performed in pancreata of 28 crossbred pigs. First, eight pancreata were intraductally injected with collagenase by a continuous controlled pressure of 180 mmHg. Pancreas samples before collagenase infusion were used as controls. All tissue samples, both before and after infusion, were stained with anti-insulin. To quantify the morphological change of the islets, the mean beta cell/endocrine content ratio of the infused and not-infused tissue samples was compared. In a second experiment, 20 pancreata were similarly assessed after intraductal injection with Hank's balanced salt solution (HBSS). RESULTS: In both the collagenase- and HBSS-infused groups, mean beta cell/endocrine content ratio was lower than in the control samples. The observed decline in the beta cell/endocrine content ratio was not significantly different between collagenase- and HBSS-infused pancreata. This suggests that the lower beta cell/endocrine content ratio and thus the morphological change in the infused tissue samples is caused by volume expansion of the fluid entering the islet and that the digestive effect of collagenase plays no or only a minor role. CONCLUSION: Morphological changes of islets are observed after infusion of pancreata with collagenase and HBSS, most likely caused by volume expansion due to fluid entering the islets.

Asunto(s)

Colagenasas/metabolismo , Islotes Pancreáticos , Soluciones Isotónicas/farmacología , Páncreas , Animales , Humanos , Islotes Pancreáticos/citología , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Páncreas/anatomía & histología , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Porcinos

Asunto(s)

Cuerpo Médico de Hospitales/organización & administración , Admisión y Programación de Personal , Unión Europea , Humanos , Países Bajos , Factores de Tiempo

RESUMEN

This case report describes a young female patient presenting with acute intra-abdominal hemorrhage originating from a large tumor in the liver, most likely a hepatocellular adenoma. The bleeding was stopped by selective embolization of right hepatic artery branches. Subsequently, partial hepatectomy was performed after 6 mo. Macro- and microscopic examination showed complete necrosis and absence of tumorous tissue. The patient was discharged without complications, and subsequent follow-up until 22 mo after resection did not reveal any new lesions in the liver. This case emphasizes the significance of selective arterial embolization in the management of bleeding liver tumors and questions the need for (partial) hepatectomy after this procedure in selective cases.

Asunto(s)

Adenoma de Células Hepáticas/complicaciones , Embolización Terapéutica/métodos , Hemorragia/terapia , Neoplasias Hepáticas/complicaciones , Adenoma de Células Hepáticas/irrigación sanguínea , Adulto , Femenino , Hemorragia/etiología , Arteria Hepática/patología , Humanos , Neoplasias Hepáticas/irrigación sanguínea , Necrosis/patología

Asunto(s)

Adenoma de Células Hepáticas/complicaciones , Hemorragia/etiología , Neoplasias Hepáticas/complicaciones , Complicaciones Neoplásicas del Embarazo , Adenoma de Células Hepáticas/diagnóstico por imagen , Diagnóstico Diferencial , Embolización Terapéutica , Femenino , Hemorragia/diagnóstico por imagen , Hemorragia/terapia , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Embarazo , Rotura Espontánea/complicaciones , Rotura Espontánea/diagnóstico por imagen , Tomografía Computarizada por Rayos X

RESUMEN

This case report describes a patient diagnosed with ongoing portal venous gas, initiated by a rather common Campylobacter enterocolitis and maintained by septic thrombophlebitis and possibly by chronic cholecystitis. Cholecystectomy attenuated the patient's septic condition. The etiology of portal venous gas determines both the patient's prognosis and the choice for either conservative or surgical treatment. This report describes persistence of portal venous gas for a long period and a possible role for chronic cholecystitis as a cause.

Asunto(s)

Infecciones por Campylobacter/complicaciones , Campylobacter/aislamiento & purificación , Embolia Aérea/microbiología , Enterocolitis/complicaciones , Infecciones por Campylobacter/microbiología , Enterocolitis/microbiología , Humanos , Masculino , Persona de Mediana Edad , Vena Porta , Tromboflebitis/complicaciones , Tromboflebitis/microbiología

RESUMEN

OBJECTIVES: The pig is generally considered a suitable alternative donor for clinical islet transplantation. However, adult pig islets are difficult to isolate and culture, often behave variably in in vitro assays, and do not consistently cure diabetic nude mice. In this study, we compared the in vivo function of freshly isolated and cultured adult porcine islets by transplantation in diabetic nude mice. METHODS: Freshly isolated and cultured islets were transplanted in different doses to diabetic nude mice (N = 48). RESULTS: Average islet yield was 1924 islet-equivalents per gram of pancreas, purity 96%, and the viability that was measured by acridine orange and propidium iodide was greater than 80% in all freshly isolated islet preparations. Grafts of freshly isolated islets failed to reduce hyperglycemia in 17 of 18 recipients. Although after 1 day of culture islet recovery was only 21%, grafts of these islets cured 12 of 17 mice. After 7 to 14 days of culture, the recovery had decreased to 11%; however, these islets reversed hyperglycemia in all mice (13/13) and showed shorter time-to-normoglycemia and more tightly regulated blood glucose. CONCLUSIONS: Although freshly isolated adult porcine islets survive culture and transplantation poorly, islets selected by prolonged culture are of high potential.

Asunto(s)

Trasplante de Islotes Pancreáticos , Islotes Pancreáticos/citología , Animales , Glucemia/análisis , Células Cultivadas , Diabetes Mellitus Experimental/cirugía , Masculino , Ratones , Ratones Desnudos , Porcinos , Trasplante Heterólogo

RESUMEN

BACKGROUND: The prognosis for patients with liver metastases from colorectal carcinoma is limited because of the low number of patients who are eligible for curative hepatic resection. In this phase I study, 31 liver metastases in 24 patients with nonresectable metastases from colorectal carcinoma were treated with photodynamic therapy (PDT). METHODS: The photosensitizer 5,10,15,20-tetrakis(m-hydroxyphenyl)bacteriochlorin (mTHPBC) was intravenously administered in a dose of .6 mg/kg (n = 12) or .3 mg/kg (n = 12). After 120 hours (n = 18) or 48 hours (n = 6), tumors were illuminated for 300 to 600 seconds through percutaneously inserted optical fibers with a light dose of 60 J/cm of diffuser (740 nm). RESULTS: Tumor necrosis at 1 month after PDT was achieved in all treated lesions. Laser treatment was associated with mild pain (n = 8) and transient subclinical hepatotoxicity (n = 21). In one patient, PDT damage to the pancreas was inflicted, and in another patient, PDT damage of the skin occurred, but no serious clinical complications from PDT were reported. Administration of .6 mg/kg of mTHPBC led to transient phlebitis in 10 patients, and 3 patients experienced mild skin phototoxicity after excess light exposure. CONCLUSIONS: Colorectal liver metastases that are ineligible for resection can be safely and effectively treated with interstitial mTHPBC-based PDT.

Asunto(s)

Neoplasias Colorrectales/secundario , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/secundario , Fotoquimioterapia/métodos , Porfirinas/uso terapéutico , Adulto , Anciano , Femenino , Humanos , Infusiones Intravenosas , Terapia por Láser , Masculino , Persona de Mediana Edad , Fotoquimioterapia/efectos adversos , Piel/patología

RESUMEN

Mannose-binding lectin (MBL) is a recognition molecule of the lectin pathway of complement and a key component of innate immunity. MBL polymorphisms have been described that are associated with MBL serum concentration, impaired function, and diabetic complications. We investigated 86 new-onset juvenile type 1 diabetic patients and compared these with their nondiabetic siblings and healthy unrelated control subjects. Polymorphisms of MBL exon 1 and promoter were determined, and serum concentration and MBL-complex activity were measured. Although the genetic polymorphisms of MBL were not different between patients and control subjects, MBL serum concentration as well as MBL complex activity was significantly higher in new-onset diabetic patients compared with their siblings matched for high-producing MBL genotypes (P = 0.0018 and P = 0.0005, respectively). The increase in MBL complex activity in high-MBL-producing patients could only partially be explained by high MBL production, as demonstrated by an increased MBL complex activity-to-MBL concentration ratio (P = 0.004). We conclude that MBL serum concentration and complex activity are increased in early-onset diabetic patients upon manifestation independently of genetic predisposition to high MBL production, indicating a possible role in the immunopathogenesis of type 1 diabetes, in addition to the adaptive islet autoimmunity.

Asunto(s)

Diabetes Mellitus Tipo 1/sangre , Lectina de Unión a Manosa/sangre , Adolescente , Autoanticuerpos/sangre , Proteína C-Reactiva/análisis , Niño , Preescolar , Diabetes Mellitus Tipo 1/genética , Femenino , Fructosamina/sangre , Predisposición Genética a la Enfermedad , Genotipo , Antígenos HLA/análisis , Humanos , Masculino , Lectina de Unión a Manosa/genética , Polimorfismo Genético , Regiones Promotoras Genéticas/genética

RESUMEN

BACKGROUND & AIMS: Infection is the primary cause of death after liver transplantation. Mannose binding lectin (MBL) is a recognition molecule of the lectin pathway of complement and a key component of innate immunity. MBL variant alleles have been described in the coding region of the MBL gene, which are associated with low MBL serum concentration and impaired MBL structure and function. The aims of our study were to establish the role of the liver in production of serum MBL and to evaluate the effect of MBL variant alleles on the susceptibility to infection after liver transplantation. METHODS: We investigated 49 patients undergoing orthotopic liver transplantation. MBL exon 1 and promoter polymorphisms were determined in patients and in liver donors. MBL serum concentration was determined before and during 1 year after transplantation. The incidence of clinically significant infections during this period was assessed. RESULTS: Transplantation of MBL wildtype recipients with donor livers carrying MBL variant alleles resulted in a rapid and pronounced decrease of serum MBL levels. This serum conversion was associated with the disappearance of high molecular weight MBL. No indication for extrahepatic production of serum MBL could be obtained. The presence of MBL variant alleles in the MBL gene of the donor liver, but not in the recipient, was associated with a strongly increased incidence of clinically significant infections after transplantation. CONCLUSIONS: Serum MBL is produced by the liver under strong genetic control. After liver transplantation, the MBL genotype of the donor liver is a major risk determinant for life-threatening infections.

Asunto(s)

Infecciones Bacterianas/genética , Trasplante de Hígado/efectos adversos , Lectina de Unión a Manosa/metabolismo , Polimorfismo Genético , Complicaciones Posoperatorias/diagnóstico , Adulto , Infecciones Bacterianas/epidemiología , Secuencia de Bases , Western Blotting , Estudios de Cohortes , Femenino , Regulación de la Expresión Génica , Marcadores Genéticos , Supervivencia de Injerto , Humanos , Incidencia , Fallo Hepático/diagnóstico , Fallo Hepático/mortalidad , Fallo Hepático/cirugía , Trasplante de Hígado/métodos , Masculino , Lectina de Unión a Manosa/genética , Persona de Mediana Edad , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Complicaciones Posoperatorias/mortalidad , Probabilidad , Pronóstico , Medición de Riesgo , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas , Tasa de Supervivencia

RESUMEN

Between 1986 and 1990 we performed heterotopic liver transplantation (HLT) in 17 patients with chronic liver disease. In spite of theoretical advantages and favorable short-term results, we abandoned HLT because of doubts about the long-term outcome and the improved results of standard orthotopic liver transplantation (OLT). There are, however, no studies comparing the long-term survival after HLT and OLT for chronic liver disease. We performed a case-control study of HLT vs. OLT, with long-term patient and graft survival as the main outcome measures. Known confounders and differences in baseline characteristics between HLT and OLT patients were corrected for. At 1 year, 5 of the 17 HLT patients had died, compared with 9 of the 34 OLT patients (relative risk [RR], 1.15; 95% confidence interval [CI], 0.33-4.02; P = 0.83). After correction for confounders, the long-term risk of graft failure (RR, 18.0; 95% CI, 1.5-223.5; P = 0.02) and of death (RR, 5.2; 95% CI, 0.8-34.8; P = 0.09) was higher after HLT than after OLT. The main causes of graft loss and death at more than 1 year after HLT were de novo malignancies and a variety of biliary complications. In conclusion, our data, from 1 of the largest single-center series of HLTs available, showed no significant difference between HLT and OLT in 1-year survival. However, the long-term outcome of HLT was inferior. HLT cannot be recommended as an alternative to OLT for any of the indications we studied, even though only 1 of the late deaths was definitely related to the heterotopic technique.

Asunto(s)

Hepatopatías/cirugía , Trasplante de Hígado/métodos , Adulto , Estudios de Casos y Controles , Causas de Muerte , Enfermedad Crónica , Femenino , Humanos , Hepatopatías/mortalidad , Trasplante de Hígado/mortalidad , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Análisis de Supervivencia , Trasplante Heterólogo , Resultado del Tratamiento

RESUMEN

OBJECTIVE: A prospective randomized multicenter study was performed to assess whether the results of pylorus-preserving pancreaticoduodenectomy (PPPD) equal those of the standard Whipple (SW) operation, especially with respect to duration of surgery, blood loss, hospital stay, delayed gastric emptying (DGE), and survival. SUMMARY BACKGROUND DATA: PPPD has been associated with a higher incidence of delayed gastric emptying, resulting in a prolonged period of postoperative nasogastric suctioning. Another criticism of the pylorus-preserving pancreaticoduodenectomy for patients with a malignancy is the radicalness of the resection. On the other hand, PPPD might be associated with a shorter operation time and less blood loss. METHODS: A prospective randomized multicenter study was performed in a nonselected series of 170 consecutive patients. All patients with suspicion of pancreatic or periampullary tumor were included and randomized for a SW or a PPPD resection. Data concerning patients' demographics, intraoperative and histologic findings, as well as postoperative mortality, morbidity, and follow-up up to 115 months after discharge, were analyzed. RESULTS: There were no significant differences noted in age, sex distribution, tumor localization, and staging. There were no differences in median blood loss and duration of operation between the 2 techniques. DGE was observed equally in the 2 groups. There was only a marginal difference in postoperative weight loss in favor of the standard Whipple procedure. Overall operative mortality was 5.3%. Tumor positive resection margins were found for 12 patients of the SW group and 19 patients of the PPPD group (P < 0.23). Long-term follow-up showed no significant statistical differences in survival between the 2 groups (P < 0.90). CONCLUSIONS: The SW and PPPD operations were associated with comparable operation time, blood loss, hospital stay, mortality, morbidity, and incidence of DGE. The overall long-term and disease-free survival was comparable in both groups. Both surgical procedures are equally effective for the treatment of pancreatic and periampullary carcinoma.

Asunto(s)

Adenocarcinoma/cirugía , Ampolla Hepatopancreática , Neoplasias del Conducto Colédoco/cirugía , Neoplasias Pancreáticas/cirugía , Pancreaticoduodenectomía/métodos , Píloro/cirugía , Adenocarcinoma/mortalidad , Adulto , Anciano , Pérdida de Sangre Quirúrgica , Neoplasias del Conducto Colédoco/mortalidad , Supervivencia sin Enfermedad , Femenino , Vaciamiento Gástrico , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/mortalidad , Pancreaticoduodenectomía/efectos adversos , Complicaciones Posoperatorias , Reoperación , Tasa de Supervivencia

RESUMEN

BACKGROUND: Donor leucocytes (DL) play an important role in rat liver transplant tolerance and their postoperative administration can convert rejection to tolerance. They appear to induce early activation, altered patterns of infiltration and death of recipient alloreactive T cells. The ability of immunosuppressive drugs to combine with DL administration was examined in a rat heart transplant model. METHODS: Immediately after PVG to DA heterotopic heart transplantation, 6 x 10(7) spleen DL were injected. Cyclosporine A (CsA), 1.5 mg/kg/day, or methotrexate (MTX), 0.1 or 0.2 mg/kg/day, were given from day (d) 0 to d4 (early) or from d3 to d7 (delayed). Castanospermine (CAST) was administered from d0 to d7 at 100 or 300 mg/kg/day. In a separate experiment, transplanted hearts and recipient spleens were collected from treatment groups for analysis of infiltrate and cytokine mRNA expression. RESULTS: Delayed treatment with CsA or early treatment with MTX but not CAST combined with DL to result in prolonged graft survival. Recipients treated with DL and delayed CsA had a reduced level of intra-graft interleukin (IL)-2, interferon (IFN)-gamma, IL-4, and IL-4R mRNA expression and reduced infiltrate compared to DL alone. Early MTX plus DL led to almost complete inhibition of all markers of inflammation during treatment followed by a rapid increase after cessation. In combination with DL, CsA was more effective than MTX for induction of donor-specific tolerance at the dose and administration regimens tested. CONCLUSIONS: Delayed CsA or early MTX combine with DL to prolong heart allograft survival. Early and extensive inhibition of rejection by MTX was less effective than delayed and partial inhibition of the response by CsA for induction of transplant tolerance.

Asunto(s)

Ciclosporina/farmacología , Supervivencia de Injerto/efectos de los fármacos , Trasplante de Corazón/inmunología , Inmunosupresores/farmacología , Indolizinas/farmacología , Transfusión de Leucocitos , Metotrexato/farmacología , Traslado Adoptivo , Animales , Terapia Combinada , Citocinas/genética , Citocinas/inmunología , Expresión Génica , Masculino , Cuidados Posoperatorios , ARN Mensajero/biosíntesis , Ratas , Ratas Endogámicas , Trasplante de Piel/inmunología , Donantes de Tejidos , Trasplante Homólogo

RESUMEN

BACKGROUND: A major drawback of allogeneic hepatocyte transplantation is the lack of sustained survival of the transplanted cells in the recipient liver parenchyma. The purpose of this study was to determine the effect of the presence or absence of hepatic extracellular matrix (ECM) molecules on hepatocyte survival and function following hepatocyte isolation for transplantation purposes, and the role of beta1-integrin molecules therein. METHODS: Hepatocytes, either untreated or treated with anti-beta1 integrin antibodies or RGD peptides, were seeded on wells precoated with collagen type I, type IV, laminin, fibronectin or polyhydroxyethylmehacrylate. The extent of attachment and apoptosis was evaluated. RESULTS: When hepatocytes were added into wells precoated with either fibronectin, or collagen type IV, rapid spreading and prolonged survival occurred, in contrast to hepatocytes that were seeded in wells precoated with collagen type I or polyhydroxyethylmehacrylate. Pretreatment of the cells with anti-beta1-integrin antibodies resulted in reduction of cell attachment to laminin, fibronectin, collagen I, and collagen IV. Synthetic RGD (arginine-glycine-aspartate)-peptides and anti-beta1 antibodies inhibited apoptosis of cultured hepatocytes. CONCLUSIONS: Our findings indicate that embedding of hepatocytes within their normal liver ECM surroundings maintains their survival. When detached from their natural surrounding hepatocytes enter into apoptosis, unless treated with anti-beta1-integrin antibodies or RGD peptides. This knowledge will allow improvement of hepatocyte transplantation efficiency.

Asunto(s)

Matriz Extracelular/fisiología , Hepatocitos/fisiología , Integrina beta1/fisiología , Hígado/metabolismo , Animales , Anoicis , Anticuerpos Monoclonales/farmacología , Apoptosis/efectos de los fármacos , Caspasa 3 , Caspasas/metabolismo , Adhesión Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Colágeno Tipo IV/farmacología , Fragmentación del ADN , Electroforesis , Femenino , Fibronectinas/farmacología , Inmunohistoquímica , Integrina beta1/inmunología , Oligopéptidos/farmacología , Ratas , Ratas Endogámicas BN

RESUMEN

Although a systemic antitumor immune response by antibodies or T cells is often detected in cancer patients, this response mostly does not result in tumor rejection. The beneficial effect of tumor vaccination on survival rates is limited as tumor response is low. In contrast to solid tumors, circulating tumor cells may be more easily accessible and therefore destroyed by the immune system and thus prevent metastases. This discrepancy is further clarified in our study, by assessing the effect of a systemic immune response on established liver tumors and circulating tumor cells. Male Wag/Rij rats were inoculated with CC531 colorectal tumor cells subcapsulary in the liver, with or without immune suppression (60 mg/kg cyclophosphamide). To study the effect of a systemic immune response, rats received CC531 tumor cells intravenously and three weeks later the number of lung tumors was assessed. Presence of specific anti-CC531 antibodies in serum was determined by flow cytometric analysis at times of inoculation, i.v. tumor cell administration and sacrifice. Rats with liver tumors and subsequent rechallenge produced anti-CC531 IgG antibodies and did not develop lung tumors, whereas without existing liver tumors, rats developed lung tumors upon i.v. administration of CC531 tumor cells. Liver tumors in rats with and without i.v. CC531 tumor cell administration were equal in size. These results showed that a systemic immune response, induced upon liver tumor induction and rechallenge, prevented formation of lung tumors but did not affect tumor growth in the liver. Possibly the immune response lacked the ability to penetrate the protective extracellular matrix surrounding the established liver tumors, which prevented the tumor cells from recognition by and contact with cells of the immune system.

Asunto(s)

Neoplasias Hepáticas Experimentales/inmunología , Neoplasias Hepáticas Experimentales/patología , Animales , Anticuerpos Antineoplásicos/sangre , Masculino , Ratas , Linfocitos T/inmunología