Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 109
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Xenotransplantation ; 30(6): e12829, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37793086

RESUMEN

A conference on progress in the development of xenotransplantation in China was held in Neijiang, Sichuan, in May 2023, and was attended by approximately 100 established researchers and trainees. Progress in xenotransplantation research was reviewed by both Chinese and foreign experts. The topics discussed ranged from genetic engineering of pigs and the results of pig-to-nonhuman primate organ transplantation to the requirements for designated pathogen-free (DPF) pig facilities and regulation of xenotransplantation. This conference served as an opportunity to collectively advance the development of xenotransplantation in China and pave the way for its clinical application.


Asunto(s)
Trasplante de Órganos , Animales , Porcinos , Trasplante Heterólogo/métodos , Ingeniería Genética , China , Animales Modificados Genéticamente
2.
Xenotransplantation ; 30(1): e12787, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36454040

RESUMEN

OBJECTIVE: Islet allotransplantation has demonstrated improved clinical outcomes using the hepatic portal vein as the standard infusion method. However, the current implantation site is not ideal due to the short-term thrombotic and long-term immune destruction. Meanwhile, the shortage of human organ donors further limits its application. To find a new strategy, we tested a new polymer combination for islet encapsulation and transplantation. Meanwhile, we explored a new site for xenogeneic islet transplantation in mice. METHOD: We synthesized a hydrogel combining alginate plus poly-ethylene-imine (Alg/PEI) for the encapsulation of rat, neonatal porcine, and human islets. Transplantation was performed into the retroperitoneal retro-colic space of diabetic mice. Control mice received free islets under the kidney capsule or encapsulated islets into the peritoneum. The biochemical indexes were measured, and the transplanted islets were harvested for immunohistochemical staining of insulin and glucagon. RESULTS: Mice receiving encapsulated rat, porcine and human islets transplanted into the retroperitoneal space maintained normoglycemia for a median of 275, 145.5, and 146 days, respectively. In contrast, encapsulated xenogeneic islets transplanted into the peritoneum, maintained function for a median of 61, 95.5, and 82 days, respectively. Meanwhile, xenogeneic islets transplanted free into the kidney capsule lost their function within 3 days after transplantation. Immunohistochemical staining of encapsulated rat, porcine and human islets, retrieved from the retroperitoneal space, allowed to distinguish morphological normal insulin expressing ß- and glucagon expressing α-cells at 70, 60, and 100 days post-transplant, respectively. CONCLUSION: Transplantation of Alg/PEI encapsulated xenogeneic islets into the retroperitoneal space provides a valuable new implantation strategy for the treatment of type 1 diabetes.


Asunto(s)
Diabetes Mellitus Experimental , Trasplante de Islotes Pancreáticos , Islotes Pancreáticos , Ratas , Ratones , Porcinos , Humanos , Animales , Islotes Pancreáticos/cirugía , Trasplante de Islotes Pancreáticos/métodos , Trasplante Heterólogo/métodos , Diabetes Mellitus Experimental/cirugía , Espacio Retroperitoneal , Glucagón , Insulina
3.
Dig Dis Sci ; 68(2): 471-477, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36125591

RESUMEN

BACKGROUND: Utilization of autologous stem cells has been proposed for the treatment of anal incontinence despite a lack of understanding of their mechanism of action and of the physiological healing process of anal sphincters after injury. AIMS: We aim to develop a technique allowing isolation and further study of local mesenchymal stem cells, directly from anal canal transition zone in pig. METHODS: Anal canal was resected "en bloc" from two young pigs and further microdissected. The anal canal transition zone was washed and digested with 0.1% type I collagenase for 45 min at 37 °C. The isolated cells were plated on dishes in mesenchymal stem cell medium and trypsinized when confluent. Cells were further used for flow cytometry analysis and differentiation assays. RESULTS: The anal canal transition zone localization was confirmed with H&E staining. Following culture, cells exhibited a typical "fibroblast-like" morphology typical of stem cells. Isolated cells were positive for CD90 and CD44 but negative for CD14, CD34, CD45, CD105, CD106, and SLA-DR. Following incubation with specific differentiation medium, isolated cells differentiated into adipocytes, osteoblasts, and chondrocytes, confirming in vitro multipotency. CONCLUSIONS: Herein, we report for the first time the presence of mesenchymal stem cells in the anal canal transition zone in pigs and the feasibility of their isolation. This preliminary study opens the path to the isolation of human anal canal transition zone mesenchymal stem cells that might be used to study sphincters healing and to treat anal incontinence.


Asunto(s)
Canal Anal , Células Madre Mesenquimatosas , Porcinos , Humanos , Animales , Separación Celular/métodos , Células Madre , Diferenciación Celular/fisiología , Células Cultivadas
4.
Xenotransplantation ; 28(3): e12681, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33759229

RESUMEN

BACKGROUND: Xenotransplantation has made tremendous progress over the last decade. METHODS: We discuss kidney and heart xenotransplantation, which are nearing initial clinical trials. RESULTS: Life sustaining genetically modified kidney xenografts can now last for approximately 500 days and orthotopic heart xenografts for 200 days in non-human primates. Anti-swine specific antibody screening, preemptive desensitization protocols, complement inhibition and targeted immunosuppression are currently being adapted to xenotransplantation with the hope to achieve better control of antibody-mediated rejection (AMR) and improve xenograft longevity. These newest advances could probably facilitate future clinical trials, a significant step for the medical community, given that dialysis remains difficult for many patients and can have prohibitive costs. Performing a successful pig-to-human clinical kidney xenograft, that could last for more than a year after transplant, seems feasible but it still has significant potential hurdles to overcome. The risk/benefit balance is progressively reaching an acceptable equilibrium for future human recipients, e.g. those with a life expectancy inferior to two years. The ultimate question at this stage would be to determine if a "proof of concept" in humans is desirable, or whether further experimental/pre-clinical advances are still needed to demonstrate longer xenograft survival in non-human primates. CONCLUSION: In this review, we discuss the most recent advances in kidney and heart xenotransplantation, with a focus on the prevention and treatment of AMR and on the recipient's selection, two aspects that will likely be the major points of discussion in the first pig organ xenotransplantation clinical trials.


Asunto(s)
Rechazo de Injerto , Trasplante de Riñón , Animales , Animales Modificados Genéticamente , Rechazo de Injerto/prevención & control , Xenoinjertos , Humanos , Terapia de Inmunosupresión , Porcinos , Trasplante Heterólogo
5.
Am J Transplant ; 20(7): 1837-1839, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32359188

RESUMEN

During the 2019 novel coronavirus (SARS-CoV-2) outbreak in China (from January 24 to March 11, 2020), our center performed 16 organ transplants (10 kidney, 4 liver, and 2 lung transplants) harvested from deceased donors. Regarding the strategies to prevent infections of SARS-CoV-2, we implemented specific measures for the donor and recipient management, as well as prevention of hospital-acquired infections. All 16 organ recipients had a favorable outcome without SARS-CoV-2 infection. Our approaches aiming to interrupt the spread of SARS-CoV-2 within the transplantation wards were successful, and allowed us to maintain the transplantation program for deceased liver, kidney, and lung organ recipients.


Asunto(s)
Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/transmisión , Trasplante de Órganos/tendencias , Pandemias/prevención & control , Neumonía Viral/prevención & control , Neumonía Viral/transmisión , Donantes de Tejidos , Betacoronavirus , COVID-19 , Prueba de COVID-19 , China/epidemiología , Técnicas de Laboratorio Clínico , Control de Enfermedades Transmisibles , Infecciones por Coronavirus/diagnóstico , Infección Hospitalaria/prevención & control , Humanos , Unidades de Cuidados Intensivos , Trasplante de Riñón , Trasplante de Hígado , Trasplante de Pulmón , Trasplante de Órganos/métodos , SARS-CoV-2 , Resultado del Tratamiento
6.
Liver Int ; 40(3): 609-621, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31872499

RESUMEN

BACKGROUND & AIMS: Our understanding of non-alcoholic fatty liver disease (NAFLD) pathogenesis is improving, but there is still limited data on the function of resident liver macrophages in this context, especially when considering their contribution in dampening liver inflammation. METHODS: Liver macrophages were studied in mouse models of prolonged diet-induced liver steatohepatitis and carbon tetrachloride-induced liver injury. We assessed liver macrophages phenotype and costimulatory/inhibitory properties upon exposure to lipopolysaccharide or interleukin 4. We did phagocytosis and antigen presentation assays to investigate liver macrophages function as scavengers and immune response initiators. Using immunofluorescence staining, we further determined, in human liver tissue of patients with simple steatosis, non-alcoholic steatohepatitis and chronic hepatitis B infection, the expression of the co-inhibitory protein CD274 (Programmed-death ligand 1) and major histocompatibility complex (MHC) class II. RESULTS: Both in humans and mice, within chronically inflamed fatty livers, liver macrophages acquired immunomodulatory properties by reducing the expression of MHC class II, and by enhancing co-inhibitory signalling. Liver macrophages circumscribed endotoxin-mediated inflammatory response by upregulating anti-inflammatory genes arginase 1 and interleukin-10. While hepatic macrophages isolated from mice with normal livers were capable of achieving endotoxin tolerance, our results indicated an impairment of this protective mechanism in the presence NASH-like parenchymal abnormalities. CONCLUSIONS: Liver macrophages can achieve endotoxin tolerance, but in the chronically inflamed fatty liver, while they acquire an immunomodulatory phenotype, liver macrophages fail to dampen immune-mediated damage. Therefore, loss of tolerogenicity induced by ongoing liver insult may be a mechanism contributing to the worsening of NAFLD.


Asunto(s)
Hepatitis , Enfermedad del Hígado Graso no Alcohólico , Animales , Humanos , Macrófagos del Hígado , Hígado , Ratones , Ratones Endogámicos C57BL
7.
Xenotransplantation ; 27(4): e12584, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-31984564

RESUMEN

BACKGROUND: Tolerogenic dendritic cells (DCs) represent a promising approach to promote transplantation tolerance. In this study, the potential of autologous bone marrow (BM)-derived murine DC to protect rat-to-mouse islets xenografts was analyzed. METHODS: Tolerogenic DCs were generated by differentiating BM cells in the presence of granulocyte-macrophage colony-stimulating factor and interleukin 10 (IL-10, IL-10 DC). The phenotype of IL-10 DC was characterized in vitro by expression of costimulatory/inhibitory molecules (flow cytometry) and cytokines (Luminex and ELISA), their function by phagocytosis and T-cell stimulation assays. To study transplant tolerance in vivo, rat islets were transplanted alone or in combination with autologous murine IL-10 DC under the kidney capsule of streptozotocin-induced diabetic C57BL/6 mice. Xenograft survival was evaluated by monitoring glycemia, cellular infiltration of xenografts by microscopy and flow cytometry 10 days post-transplantation. RESULTS: Compared with control DC, IL-10 DC exhibited lower levels of major histocompatibility complex class II, costimulatory molecules (CD40, CD86, CD205), lower production of pro-inflammatory cytokines (IL-12p70, TNF, IL-6), and higher production of IL-10. Phagocytosis of xenogeneic rat splenocytes was not impaired in IL-10 DC, whereas stimulation of T-cell proliferation was reduced in the presence of IL-10 DC. Xenograft survival of rat islets in diabetic mice co-transplanted with autologous murine IL-10 DC was significantly prolonged from 12 to 21 days, without additional immunosuppressive treatment. Overall, infiltration of xenografts by T cells and myeloid cells was not different in IL-10 DC recipient mice, but enriched for CD8+ T cells and myeloid cells with suppressor-associated phenotype. CONCLUSIONS: Autologous IL-10-differentiated DC with tolerogenic properties prolong rat-to-mouse islets xenograft survival, potentially by locally inducing immune regulatory cells, indicating their potential for regulatory immune cell therapy in xenotransplantation.


Asunto(s)
Células Dendríticas/trasplante , Diabetes Mellitus Experimental , Supervivencia de Injerto , Interleucina-10 , Trasplante Heterólogo , Animales , Células Cultivadas , Diabetes Mellitus Experimental/terapia , Xenoinjertos , Ratones , Ratones Endogámicos C57BL , Ratas
8.
Transpl Int ; 32(5): 459-469, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30903673

RESUMEN

The lack of suitable kidney donor organs has led to rising numbers of patients with end stage renal disease waiting for kidney transplantation. Despite decades of clinical experience and research, no evaluation process that can reliably predict the outcome of an organ has yet been established. This review is an overview of current methods and emerging techniques in the field of donor kidney evaluation prior to transplantation. Established techniques like histological evaluation, clinical scores, and machine perfusion systems offer relatively reliable predictions of delayed graft function but are unable to consistently predict graft survival. Emerging techniques including molecular biomarkers, new imaging technologies, and normothermic machine perfusion offer innovative approaches toward a more global evaluation of an organ with better outcome prediction and possibly even identification of targets for therapeutic interventions prior to transplantation. These techniques should be studied in randomized controlled trials to determine whether they can be safely used in routine clinical practice to ultimately reduce the discard rate and improve graft outcomes.


Asunto(s)
Fallo Renal Crónico/cirugía , Trasplante de Riñón , Obtención de Tejidos y Órganos/métodos , Animales , Biomarcadores/metabolismo , Biopsia , Funcionamiento Retardado del Injerto , Supervivencia de Injerto , Humanos , Riñón , Metabolómica , Preservación de Órganos/métodos , Perfusión , Proteómica , Porcinos , Donantes de Tejidos , Resultado del Tratamiento
9.
Transpl Int ; 32(9): 903-912, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31033036

RESUMEN

Pancreatic islet allotransplantation is a treatment for patients with severe forms of type 1 diabetes. As long-term graft function and survival are not yet optimal, additional studies are warranted in order to continue improving transplant outcomes. The mechanisms of islet graft loss and tolerance induction are often studied in murine diabetes models. Despite numerous islet transplantation studies successfully performed over recent years, translation from experimental mouse models to human clinical application remains elusive. This review aims at critically discussing the strengths and limitations of current mouse models of diabetes and experimental islet transplantation. In particular, we will analyze the causes leading to diabetes and compare the immunological mechanisms responsible for rejection between mouse and human. A better understanding of the experimental mouse models should facilitate translation to human clinical application.


Asunto(s)
Trasplante de Islotes Pancreáticos/inmunología , Animales , Diabetes Mellitus Experimental/inmunología , Diabetes Mellitus Tipo 1/inmunología , Humanos , Ratones , Trasplante Homólogo
10.
Int J Mol Sci ; 20(6)2019 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-30875826

RESUMEN

BACKGROUND: Interleukin-1 (IL-1)ß and IL-1 receptor antagonist (IL-1Ra) have been proposed as important mediators during chronic liver diseases. We aimed to determine whether the modulation of IL-1ß signaling with IL-1Ra impacts on liver fibrosis. METHODS: We assessed the effects of IL-1ß on human hepatic stellate cells (HSC) and in mouse models of liver fibrosis induced by bile duct ligation (BDL) or carbon tetrachloride treatment (CCl-4). RESULTS: Human HSCs treated with IL-1ß had increased IL-1ß, IL-1Ra, and MMP-9 expressions in vitro. HSCs treated with IL-1ß had reduced α-smooth muscle actin expression. These effects were all prevented by IL-1Ra treatment. In the BDL model, liver fibrosis and Kuppfer cell numbers were increased in IL-1Ra KO mice compared to wild type mice and wild type mice treated with IL-1Ra. In contrast, after CCl-4 treatment, fibrosis, HSC and Kupffer cell numbers were decreased in IL-1Ra KO mice compared to the other groups. IL-1Ra treatment provided a modest protective effect in the BDL model and was pro-fibrotic in the CCl-4 model. CONCLUSIONS: We demonstrated bivalent effects of IL-1Ra during liver fibrosis in mice. IL-1Ra was detrimental in the CCl-4 model, whereas it was protective in the BDL model. Altogether these data suggest that blocking IL-1-mediated inflammation may be beneficial only in selective liver fibrotic disease.


Asunto(s)
Actinas/genética , Proteína Antagonista del Receptor de Interleucina 1/genética , Interleucina-1beta/genética , Cirrosis Hepática/genética , Metaloproteinasa 9 de la Matriz/genética , Animales , Tetracloruro de Carbono/efectos adversos , Recuento de Células , Células Cultivadas , Modelos Animales de Enfermedad , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas de Inactivación de Genes , Humanos , Macrófagos del Hígado/citología , Macrófagos del Hígado/efectos de los fármacos , Macrófagos del Hígado/inmunología , Cirrosis Hepática/etiología , Cirrosis Hepática/inmunología , Masculino , Ratones , Regulación hacia Arriba
11.
Bioconjug Chem ; 29(6): 1932-1941, 2018 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-29787238

RESUMEN

The controlled release of small molecular modulators of the immune response from hydrogel microspheres (MS) used for cell immobilization is an attractive approach to reduce pericapsular fibrotic overgrowth (PFO) after transplantation. Ketoprofen is a well-known nonsteroidal anti-inflammatory drug involved in the early stage inflammation cascade. PEGylated derivatives of ketoprofen, presenting either ester or amide linkage to the drug, were synthesized and conjugated to the hydroxyl groups of sodium alginate (Na-alg). Functionalized cell-free and MIN6 cells containing MS were produced from the resulting modified alginates. In vitro quantification of ketoprofen release indicated regular and sustained drug delivery over 14 days, resulting from the hydrolytic cleavage of the ester bond. The release kinetics was enhanced over the initial 7 days by the presence of MIN6 cells, probably as a result of cell esterase activity. In the presence of amide bond, traces of ketoprofen were released over 14 days due to a much slower hydrolysis kinetics. Cell-free and MIN6 cells containing MS were transplanted in immune-competent mice, either in the peritoneal cavity or under the kidney capsule, with a follow-up period of 30 days. Comparison with nonmodified Ca-alg MS transplanted in the same conditions demonstrated a clear reduction in the severity of PFO for MS functionalized with ketoprofen. Quantification of collagen deposition on MIN6 cells containing MS transplanted under the kidney capsule revealed the significant effect of ketoprofen release to decrease fibrotic tissue formation. The impact was more pronounced when the drug was covalently conjugated by an ester linkage, allowing higher concentration of the anti-inflammatory compound to be delivered at the transplantation site. The functionality of microencapsulated MIN6 cells 30 days after transplantation was confirmed by detection of insulin positive cell content.


Asunto(s)
Alginatos/química , Antiinflamatorios no Esteroideos/administración & dosificación , Células Secretoras de Insulina/trasplante , Cetoprofeno/administración & dosificación , Animales , Antiinflamatorios no Esteroideos/farmacocinética , Antiinflamatorios no Esteroideos/farmacología , Cápsulas , Línea Celular , Células Inmovilizadas/citología , Células Inmovilizadas/trasplante , Colágeno/análisis , Preparaciones de Acción Retardada/química , Composición de Medicamentos , Fibrosis , Células Secretoras de Insulina/citología , Cetoprofeno/farmacocinética , Cetoprofeno/farmacología , Riñón/efectos de los fármacos , Riñón/patología , Ratones Endogámicos C57BL
12.
Transpl Int ; 31(5): 465-477, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29210109

RESUMEN

The field of xenotransplantation has fluctuated between great optimism and doubts over the last 50 years. The initial clinical attempts were extremely ambitious but faced technical and ethical issues that prompted the research community to go back to preclinical studies. Important players left the field due to perceived xenozoonotic risks and the lack of progress in pig-to-nonhuman-primate transplant models. Initial apparently unsurmountable issues appear now to be possible to overcome due to progress of genetic engineering, allowing the generation of multiple-xenoantigen knockout pigs that express human transgenes and the genomewide inactivation of porcine endogenous retroviruses. These important steps forward were made possible by new genome editing technologies, such as CRISPR/Cas9, allowing researchers to precisely remove or insert genes anywhere in the genome. An additional emerging perspective is the possibility of growing humanized organs in pigs using blastocyst complementation. This article summarizes the current advances in xenotransplantation research in nonhuman primates, and it describes the newly developed genome editing technology tools and interspecific organ generation.


Asunto(s)
Trasplante Heterólogo , Animales , Animales Modificados Genéticamente , Edición Génica , Rechazo de Injerto/etiología , Humanos , Primates , Porcinos , Quimera por Trasplante , Trasplante Heterólogo/efectos adversos
13.
Biomacromolecules ; 18(9): 2747-2755, 2017 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-28742341

RESUMEN

The production of hydrogel microspheres (MS) for cell immobilization, maintaining the favorable properties of alginate gels but presenting enhanced performance in terms of in vivo durability and physical properties, is desirable to extend the therapeutic potential of cell transplantation. A novel type of hydrogel MS was produced by straightforward functionalization of sodium alginate (Na-alg) with heterotelechelic poly(ethylene glycol) (PEG) derivatives equipped with either end thiol or 1,2-dithiolane moieties. Activation of the hydroxyl moieties of the alginate backbone in the form of imidazolide intermediate allowed for fast conjugation to PEG oligomers through a covalent carbamate linkage. Evaluation of the modified alginates for the preparation of MS combining fast ionic gelation ability of the alginate carboxylate groups and slow covalent cross-linking provided by the PEG-end functionalities highlighted the influence of the chemical composition of the PEG-grafting units on the physical characteristics of the MS. The mechanical properties of the MS (resistance and shape recovery) and durability of PEG-grafted alginates in physiological environment can be adjusted by varying the nature of the end functionalities and the length of the PEG chains. In vitro cell microencapsulation studies and preliminary in vivo assessment suggested the potential of these hydrogels for cell transplantation applications.


Asunto(s)
Alginatos/química , Composición de Medicamentos/métodos , Hidrogeles/química , Microesferas , Animales , Línea Celular Tumoral , Hidrogeles/efectos adversos , Hidrogeles/síntesis química , Ratones , Ratones Endogámicos C57BL , Polietilenglicoles/química
14.
Xenotransplantation ; 24(3)2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28261903

RESUMEN

BACKGROUND: There is no standard therapy for acute liver failure. Hepatocyte transplantation has been proposed for temporary liver function support, while the injured liver regenerates or while waiting for transplantation. We have previously shown such efficacy for microencapsulated porcine hepatocytes in mice with fulminant liver failure. We aimed to establish a large animal model for fulminant liver failure to assess the efficacy of microencapsulated porcine hepatocytes in temporary liver function support. METHODS: The model was developed in baboons; for testing microencapsulated hepatocytes, the best condition was 75% hepatectomy and 60 min warm ischemia time. Fulminant liver failure was characterized by steep increases in liver biochemical parameters, severe steatosis, and massive hepatocyte necrosis during the first 10 days. Hepatocytes from miniature swine were microencapsulated in alginate-poly-l-lysine microspheres, and transplanted intraperitoneally immediately after hepatectomy and warm ischemia (80-120 mL packed hepatocytes in 200-350 mL microspheres, about 30%-50% of the baboon's native liver volume). RESULTS: In the control group, three of five animals were sacrificed after 6-10 days because of fulminant liver failure, and two of five animals recovered normal liver function and survived until elective euthanasia (28 days). In the treatment group of four animals, one animal developed liver failure but survived to 21 days, and three animals recovered completely with normal liver function. CONCLUSIONS: The results indicate that microencapsulated porcine hepatocytes provide temporary liver function support in baboons with fulminant liver failure. These data support development of this cell therapy product toward clinical trials in patients with acute liver failure.


Asunto(s)
Trasplante de Células/métodos , Hepatocitos/trasplante , Fallo Hepático Agudo/terapia , Trasplante Heterólogo/métodos , Animales , Separación Celular/métodos , Modelos Animales de Enfermedad , Inmunohistoquímica , Estimación de Kaplan-Meier , Antígeno Ki-67/metabolismo , Fallo Hepático Agudo/patología , Fallo Hepático Agudo/fisiopatología , Masculino , Ratones , Microesferas , Papio hamadryas , Porcinos , Porcinos Enanos
15.
Kidney Int ; 89(4): 927-38, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26924055

RESUMEN

There are conflicting data on the role of the lectin pathway of complement activation and its recognition molecules in acute rejection and outcome after transplantation. To help resolve this we analyzed polymorphisms and serum levels of lectin pathway components in 710 consecutive kidney transplant recipients enrolled in the nationwide Swiss Transplant Cohort Study, together with all biopsy-proven rejection episodes and 1-year graft and patient survival. Functional mannose-binding lectin (MBL) levels were determined in serum samples, and previously described MBL2, ficolin 2, and MBL-associated serine protease 2 polymorphisms were genotyped. Low MBL serum levels and deficient MBL2 diplotypes were associated with a higher incidence of acute cellular rejection during the first year, in particular in recipients of deceased-donor kidneys. This association remained significant (hazard ratio 1.75, 95% confidence interval 1.18-2.60) in a Cox regression model after adjustment for relevant covariates. In contrast, there was no significant association with rates of antibody-mediated rejection, patient death, early graft dysfunction or loss. Thus, results in a prospective multicenter contemporary cohort suggest that MBL2 polymorphisms result in low MBL serum levels and are associated with acute cellular rejection after kidney transplantation. Since MBL deficiency is a relatively frequent trait in the normal population, our findings may lead to individual risk stratification and customized immunosuppression.


Asunto(s)
Rechazo de Injerto/genética , Trasplante de Riñón , Lectinas/genética , Lectina de Unión a Manosa/genética , Serina Proteasas Asociadas a la Proteína de Unión a la Manosa/genética , Estudios de Cohortes , Lectina de Unión a Manosa de la Vía del Complemento , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Rechazo de Injerto/epidemiología , Humanos , Incidencia , Masculino , Lectina de Unión a Manosa/sangre , Persona de Mediana Edad , Polimorfismo Genético , Suiza/epidemiología , Ficolinas
16.
Xenotransplantation ; 23(1): 14-24, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26940509

RESUMEN

Islet xenotransplantation represents an attractive solution to overcome the shortage of human islets for use in type 1 diabetes. The wide-scale application of clinical islet xenotransplantation, however, requires that such a procedure takes place in a specifically and tightly regulated environment. With a view to promoting the safe application of clinical islet xenotransplantation, a few years ago the International Xenotransplantation Association (IXA) published a Consensus Statement that outlined the key ethical and regulatory requirements to be satisfied before the initiation of xenotransplantation studies in diabetic patients. This earlier IXA Statement also documented a disparate regulatory landscape among different geographical areas. This situation clearly fell short of the 2004 World Health Assembly Resolution WHA57.18 that urged Member States "to cooperate in the formulation of recommendations and guidelines to harmonize global practices" to ensure the highest ethical and regulatory standards on a global scale. In this new IXA report, IXA members who are active in xenotransplantation research in their respective geographic areas herewith briefly describe changes in the regulatory frameworks that have taken place in the intervening period in the various geographic areas or countries. The key reassuring take-home message of the present report is that many countries have embraced the encouragement of the WHO to harmonize the procedures in a more global scale. Indeed, important regulatory changes have taken place or are in progress in several geographic areas that include Europe, Korea, Japan, and China. Such significant regulatory changes encompass the most diverse facets of the clinical application of xenotransplantation and comprise ethical aspects, source animals and product specifications, study supervision, sample archiving, patient follow-up and even insurance coverage in some legislations. All these measures are expected to provide a better care and protection of recipients of xenotransplants but also a higher safety profile to xenotransplantation procedures with an ultimate net gain in terms of international public health.


Asunto(s)
Diabetes Mellitus Tipo 1/cirugía , Trasplante de Islotes Pancreáticos , Selección de Paciente/ética , Trasplante Heterólogo/legislación & jurisprudencia , Animales , Ensayos Clínicos como Asunto , Humanos , Consentimiento Informado/ética , Trasplante de Islotes Pancreáticos/métodos , Porcinos , Trasplante Heterólogo/métodos
17.
Genomics ; 106(2): 107-15, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25979460

RESUMEN

The expression of plasma proteins changes dramatically as a result of cytokine induction, particularly interleukin-6, and their levels are used as clinical markers of inflammation. miRNAs are important regulators of gene expression and play significant roles in many inflammatory diseases and processes. The interactions between miRNAs and the genes that they regulate during the acute phase response have not been investigated. We examined the effects of IL-6 stimulation on the transcriptome and miRNome of human and mouse primary hepatocytes and the HepG2 cell line. Using an integrated analysis, we identified differentially expressed miRNAs whose seed sequences are significantly enriched in the 3' untranslated regions of differentially expressed genes, many of which are involved in inflammation-related pathways. Our finding that certain miRNAs may de-repress critical acute phase proteins within acute timeframes has important biological and clinical implications.


Asunto(s)
Hepatocitos/metabolismo , Interleucina-6/farmacología , MicroARNs/metabolismo , ARN Mensajero/metabolismo , Proteínas de Fase Aguda/biosíntesis , Proteínas de Fase Aguda/genética , Animales , Células Cultivadas , Células Hep G2 , Hepatocitos/efectos de los fármacos , Humanos , Ratones , Transcriptoma/efectos de los fármacos
18.
Rev Med Suisse ; 12(523): 1174-9, 2016 Jun 15.
Artículo en Francés | MEDLINE | ID: mdl-27487622

RESUMEN

The detection rate of cystic lesions of the pancreas has increased following the widespread use of high-resolution imaging technologies. CT-scan, MRI and echo-endoscopy are diagnostic modalities. Pseudocyst is the most common lesion. It is benign and can be managed with endoscopic treatment. Mucinous cystic neoplasia and Intraductal Papillary Mucinous Neoplasia (IPMN) carry a risk for malignant transformation. The surgical treatment of these lesions has to be discussed by a multidisciplinary board. Serous cystic neoplasia and pseudopapillar and solid neoplasia are two rare types of lesion. The aim of this article is to present the diagnostic pathway and the management of these lesions from the general practitioner point of view.


Asunto(s)
Quiste Pancreático/diagnóstico , Conducta Cooperativa , Diagnóstico Diferencial , Diagnóstico por Imagen , Humanos , Quiste Pancreático/cirugía , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/cirugía , Grupo de Atención al Paciente , Atención Primaria de Salud , Derivación y Consulta
19.
J Hepatol ; 62(3): 634-41, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25450712

RESUMEN

BACKGROUND & AIMS: Mesenchymal stem cell (MSC) transplantation was shown to be effective for the treatment of liver fibrosis, but the mechanisms of action are not yet fully understood. We transplanted encapsulated human MSCs in two mouse models of liver fibrosis to determine the mechanisms behind the protective effect. METHODS: Human bone marrow-derived MSCs were microencapsulated in novel alginate-polyethylene glycol microspheres. In vitro, we analyzed the effect of MSC-conditioned medium on the activation of hepatic stellate cells and the viability, proliferation, cytokine secretion, and differentiation capacity of encapsulated MSCs. The level of fibrosis induced by bile duct ligation (BDL) or carbon tetrachloride (CCl4) was assessed after intraperitoneal transplantation of encapsulated MSCs, encapsulated human fibroblasts, and empty microspheres. RESULTS: MSC-conditioned medium inhibited hepatic stellate cell activation and release of MSC secreted anti-apoptotic (IL-6, IGFBP-2) and anti-inflammatory (IL-1Ra) cytokines. Viability, proliferation, and cytokine secretion of microencapsulated MSCs were similar to those of non-encapsulated MSCs. Within the microspheres, MSCs maintained their capacity to differentiate into adipocytes, chondrocytes, and osteocytes. 23% (5/22) of the MSC clones were able to produce anti-inflammatory IL-1Ra in vitro. Microencapsulated MSCs significantly delayed the development of BDL- and CCl4-induced liver fibrosis. Fibroblasts had an intermediate effect against CCl4-induced fibrosis. Mice transplanted with encapsulated MSCs showed lower mRNA levels of collagen type I, whereas levels of matrix metalloproteinase 9 were significantly higher. Human IL-1Ra was detected in the serum of 36% (4/11) of the mice transplanted with microencapsulated MSCs. CONCLUSIONS: MSC-derived soluble molecules are responsible for an anti-fibrotic effect in experimental liver fibrosis.


Asunto(s)
Cirrosis Hepática Experimental/terapia , Trasplante de Células Madre Mesenquimatosas/métodos , Adulto , Células Madre Adultas/trasplante , Alanina Transaminasa/sangre , Alginatos , Animales , Aspartato Aminotransferasas/sangre , Conductos Biliares , Tetracloruro de Carbono/toxicidad , Proliferación Celular , Supervivencia Celular , Medios de Cultivo Condicionados , Citocinas/metabolismo , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/patología , Xenoinjertos , Humanos , Ligadura , Cirrosis Hepática Experimental/metabolismo , Cirrosis Hepática Experimental/patología , Masculino , Metaloproteinasa 9 de la Matriz/genética , Ratones , Ratones Endogámicos DBA , Microesferas , Polietilenglicoles , ARN Mensajero/genética , ARN Mensajero/metabolismo
20.
Rev Med Suisse ; 11(479): 1345-50, 2015 Jun 17.
Artículo en Francés | MEDLINE | ID: mdl-26255496

RESUMEN

Spleen gathers numerous functions and plays a critical role in immunity against encapsulated bacteria. Anatomical injuries or physiological spleen dysfunctions can lead to complete (asplenism) or partial (hyposplenism) functional deficits and expose the patient to the risk of fulminant sepsis, as well as to thromboembolic complications. The purpose of this article is to provide the primary care physician with the tools needed to identify functional disorders of the spleen and to prevent their complications. The latest recommendations for antibiotic prophylaxis and immunization are also addressed.


Asunto(s)
Esplenectomía , Antibacterianos/uso terapéutico , Humanos , Enfermedades del Bazo/etiología , Enfermedades del Bazo/cirugía , Vacunación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA