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1.
Am J Transplant ; 14(10): 2275-87, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25220221

RESUMEN

The generation of pigs with genetic modifications has significantly advanced the field of xenotransplantation. New genetically engineered pigs were produced on an α1,3-galactosyltransferase gene-knockout background with ubiquitous expression of human CD46, with islet beta cell-specific expression of human tissue factor pathway inhibitor and/or human CD39 and/or porcine CTLA4-lg. Isolated islets from pigs with 3, 4 or 5 genetic modifications were transplanted intraportally into streptozotocin-diabetic, immunosuppressed cynomolgus monkeys (n = 5). Immunosuppression was based on anti-CD154 mAb costimulation blockade. Monitoring included features of early islet destruction, glycemia, exogenous insulin requirement and histopathology of the islets at necropsy. Using these modified pig islets, there was evidence of reduced islet destruction in the first hours after transplantation, compared with two series of historical controls that received identical therapy but were transplanted with islets from pigs with either no or only one genetic modification. Despite encouraging effects on early islet loss, these multi-transgenic islet grafts did not demonstrate consistency in regard to long-term success, with only two of five demonstrating function beyond 5 months.


Asunto(s)
Trasplante de Islotes Pancreáticos , Trasplante Heterólogo , Animales , Animales Modificados Genéticamente , Glucemia/análisis , Antígeno CTLA-4/inmunología , Femenino , Glucosa/administración & dosificación , Inmunosupresores/administración & dosificación , Hígado/patología , Macaca fascicularis , Proteína Cofactora de Membrana/inmunología , Páncreas/patología , Porcinos
2.
Cryo Letters ; 34(4): 388-95, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23995406

RESUMEN

Cryopreservation of nematode Caenorhabditis elegans in the adult stage is of importance as the nematode is a powerful research model organism. In this study, we applied the protocol previously established for cryopreservation of the L4 nematode to the adult one, and achieved a survival rate of 84%. When ice seeding was induced with bacteria P. syringae directly added to the nematode suspension instead of using a pre-cooled steel sticking needle, comparable survival rate was obtained after thawing. Moreover, a simple freezing device composed of a polystyrene foam box surrounded by a Dewar vessel put in a deep freezer was developed for a practical use. This simple method obtained a survival rate of 69 ± 4% for the adult nematode after thawing.


Asunto(s)
Caenorhabditis elegans/fisiología , Criopreservación/instrumentación , Hielo , Animales , Caenorhabditis elegans/crecimiento & desarrollo , Caenorhabditis elegans/ultraestructura , Criopreservación/métodos , Diseño de Equipo , Congelación , Hielo/análisis , Pseudomonas syringae/química
3.
Am J Transplant ; 13(8): 1989-2005, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23758811

RESUMEN

We examined the influence of regulatory dendritic cells (DCreg), generated from cytokine-mobilized donor blood monocytes in vitamin D3 and IL-10, on renal allograft survival in a clinically relevant rhesus macaque model. DCreg expressed low MHC class II and costimulatory molecules, but comparatively high levels of programmed death ligand-1 (B7-H1), and were resistant to pro-inflammatory cytokine-induced maturation. They were infused intravenously (3.5-10 × 10(6) /kg), together with the B7-CD28 costimulation blocking agent CTLA4Ig, 7 days before renal transplantation. CTLA4Ig was given for up to 8 weeks and rapamycin, started on Day -2, was maintained with tapering of blood levels until full withdrawal at 6 months. Median graft survival time was 39.5 days in control monkeys (no DC infusion; n = 6) and 113.5 days (p < 0.05) in DCreg-treated animals (n = 6). No adverse events were associated with DCreg infusion, and there was no evidence of induction of host sensitization based on circulating donor-specific alloantibody levels. Immunologic monitoring also revealed regulation of donor-reactive memory CD95(+) T cells and reduced memory/regulatory T cell ratios in DCreg-treated monkeys compared with controls. Termination allograft histology showed moderate combined T cell- and Ab-mediated rejection in both groups. These findings justify further preclinical evaluation of DCreg therapy and their therapeutic potential in organ transplantation.


Asunto(s)
Células Dendríticas/trasplante , Supervivencia de Injerto/inmunología , Tolerancia Inmunológica/inmunología , Memoria Inmunológica/inmunología , Enfermedades Renales/prevención & control , Trasplante de Riñón/inmunología , Linfocitos T Reguladores/inmunología , Abatacept , Animales , Terapia Combinada , Células Dendríticas/citología , Células Dendríticas/inmunología , Inmunoconjugados/inmunología , Inmunosupresores/uso terapéutico , Enfermedades Renales/inmunología , Macaca mulatta , Masculino , Sirolimus/uso terapéutico , Trasplante Homólogo
4.
Am J Transplant ; 12(11): 3047-60, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22947059

RESUMEN

Despite improvement in early outcome, rejection particularly chronic allograft enteropathy continues to be a major barrier to long-term visceral engraftment. The potential role of donor specific antibodies (DSA) was examined in 194 primary adult recipients. All underwent complement-dependent lymphocytotoxic crossmatch (CDC-XM) with pre- and posttransplant solid phase HLA-DSA assay in 156 (80%). Grafts were ABO-identical with random HLA-match. Liver was included in 71 (37%) allografts. Immunosuppression was tacrolimus-based with antilymphocyte recipient pretreatment in 150 (77%). CDC-XM was positive in 55 (28%). HLA-DSA was detectable before transplant in 49 (31%) recipients with 19 continuing to have circulating antibodies. Another 19 (18%) developed de novo DSA. Ninety percent of patients with preformed DSA harbored HLA Class-I whereas 74% of recipients with de novo antibodies had Class-II. Gender, age, ABO blood-type, cold ischemia, splenectomy and allograft type were significant DSA predictors. Preformed DSA significantly (p < 0.05) increased risk of acute rejection. Persistent and de novo HLA-DSA significantly (p < 0.001) increased risk of chronic rejection and associated graft loss. Inclusion of the liver was a significant predictor of better outcome (p = 0.004, HR = 0.347) with significant clearance of preformed antibodies (p = 0.04, OR = 56) and lower induction of de novo DSA (p = 0.07, OR = 24). Innovative multifaceted anti-DSA strategies are required to further improve long-term survival particularly of liver-free allografts.


Asunto(s)
Antígenos HLA/inmunología , Intestinos/trasplante , Trasplante de Hígado/inmunología , Adulto , Análisis de Varianza , Biopsia con Aguja , Estudios Transversales , Femenino , Estudios de Seguimiento , Rechazo de Injerto/inmunología , Supervivencia de Injerto/inmunología , Prueba de Histocompatibilidad , Humanos , Inmunohistoquímica , Isoanticuerpos/inmunología , Trasplante de Hígado/métodos , Masculino , Persona de Mediana Edad , Trasplante de Órganos/métodos , Valores de Referencia , Medición de Riesgo , Factores de Tiempo , Donantes de Tejidos , Trasplante Homólogo/inmunología , Resultado del Tratamiento
5.
Neurology ; 78(18): 1441-8, 2012 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-22517098

RESUMEN

OBJECTIVE: Compensatory reorganization of the nigrostriatal system is thought to delay the onset of symptoms in early Parkinson disease (PD). Here we sought evidence that compensation may be a part of a more widespread functional reorganization in sensorimotor networks, including primary motor cortex. METHODS: Several neurophysiologic measures known to be abnormal in the motor cortex (M1) of patients with advanced PD were tested on the more and less affected side of 16 newly diagnosed and drug-naive patients with PD and compared with 16 age-matched healthy participants. LTP-like effects were probed using a paired associative stimulation protocol. We also measured short interval intracortical inhibition, intracortical facilitation, cortical silent period, and input/output curves. RESULTS: The less affected side in patients with PD had preserved intracortical inhibition and a larger response to the plasticity protocol compared to healthy participants. On the more affected side, there was no response to the plasticity protocol and inhibition was reduced. There was no difference in input/output curves between sides or between patients with PD and healthy participants. CONCLUSIONS: Increased motor cortical plasticity on the less affected side is consistent with a functional reorganization of sensorimotor cortex and may represent a compensatory change that contributes to delaying onset of clinical symptoms. Alternatively, it may reflect a maladaptive plasticity that provokes symptom onset. Plasticity deteriorates as the symptoms progress, as seen on the more affected side. The rate of change in paired associative stimulation response over time could be developed into a surrogate marker of disease progression in PD.


Asunto(s)
Potenciación a Largo Plazo/fisiología , Corteza Motora/fisiopatología , Plasticidad Neuronal/fisiología , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/fisiopatología , Corteza Somatosensorial/fisiopatología , Adulto , Anciano , Cuerpo Estriado/fisiopatología , Dominancia Cerebral/fisiología , Potenciales Evocados Motores/fisiología , Femenino , Humanos , Contracción Isométrica/fisiología , Masculino , Persona de Mediana Edad , Red Nerviosa/fisiopatología , Inhibición Neural/fisiología , Aprendizaje por Asociación de Pares/fisiología , Tractos Piramidales/fisiopatología , Tiempo de Reacción/fisiología , Valores de Referencia , Umbral Sensorial/fisiología , Sustancia Negra/fisiopatología
6.
Acta Physiol (Oxf) ; 204(3): 344-53, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21838785

RESUMEN

AIM: To examine the blood flow (BF) response in the lower abdomen (LAB) in recovery following upright cycling exercise at three levels of relative maximum pulmonary oxygen consumption (VO(2max)) and the relationship of BF(LAB) to heart rate (HR) and target intensity. METHODS: For 11 healthy subjects, BF (Doppler ultrasound) in the upper abdominal aorta (Ao) above the coeliac trunk and in the right femoral artery (RFA) was measured repeatedly for 720 s after the end of cycling exercises at target intensities of 30%, 50% and 85% VO(2max), respectively. Blood flow in the lower abdomen (BF(LAB)) can be measured by subtracting bilateral BF(FAs) (≈twofolds of BF(RFA)) from BF(Ao). Change in BF(LAB) (or BF(LAB) volume) at any point was evaluated by difference between change in BF(Ao) and in BF(FAs). Heart rate and blood pressure were also measured. RESULTS: At 85% VO(2max), significant reduction in BF(LAB) by approx. 89% was shown at 90 s and remained until 360 s. At 50% VO(2max), reduction in BF(LAB) by approx. 33% was found at 90 s although it returned to pre-exercise value at 120 s. On the contrary at 30% VO(2max), BF(LAB) showed a light increase (<20%) below 70 bpm of HR. There was a close negative relationship (P < 0.05) between change in BF(LAB) and recovery HR, as well as between change in BF(LAB) volume and both recovery HR and % VO(2max). CONCLUSION: This study suggests that the lower abdominal BF in recovery may be influenced by sympathetic-vagus control, and dynamics of BF(LAB) may be closely related to the level of relative exercise intensities.


Asunto(s)
Abdomen/irrigación sanguínea , Aorta Abdominal/fisiología , Ciclismo , Ejercicio Físico , Arteria Femoral/fisiología , Frecuencia Cardíaca , Circulación Esplácnica , Adulto , Análisis de Varianza , Aorta Abdominal/diagnóstico por imagen , Presión Sanguínea , Arteria Femoral/diagnóstico por imagen , Humanos , Modelos Lineales , Masculino , Contracción Muscular , Consumo de Oxígeno , Ventilación Pulmonar , Recuperación de la Función , Flujo Sanguíneo Regional , Factores de Tiempo , Ultrasonografía Doppler , Adulto Joven
7.
Am J Transplant ; 11(11): 2508-16, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21668631

RESUMEN

Prostaglandins have been evaluated for their ability to reduce IRI after liver transplantation; however, poor stability, side effects and the inability to show a significant difference in primary endpoint have limited their clinical application. Treprostinil, a prostacyclin (PGI(2) ) analog, has a higher potency and longer elimination half-life than other commercially available PGI(2) analogs. We examined the efficacy of treprostinil to prevent IRI during OLT. OLT was performed in syngeneic Lewis rats after 18 h of cold preservation (4°C) in the UW solution. IRI significantly increased serum ALT and AST levels, neutrophil infiltration, hepatic necrosis and mRNA levels of proinflammatory cytokines post-OLT, while treatment with treprostinil decreased all the parameters. Cold storage of liver grafts significantly reduced ATP levels and treprostinil restored energy levels in liver grafts early postreperfusion. In addition, treprostinil preserved the sinusoidal endothelial cell lining and reduced platelet deposition early post-transplantation compared to placebo. Hepatic tissue blood flow was significantly compromised in the placebo group, whereas treprostinil maintained blood-flow similar to normal levels. Treprostinil protected the liver graft against IRI during OLT. Treprostinil has the potential to serve as a therapeutic option to protect the liver graft against I/R injury in patients undergoing OLT.


Asunto(s)
Epoprostenol/análogos & derivados , Trasplante de Hígado/fisiología , Daño por Reperfusión/prevención & control , Adenosina Trifosfato/metabolismo , Animales , Isquemia Fría , Epoprostenol/uso terapéutico , Interferón gamma/biosíntesis , Circulación Hepática/efectos de los fármacos , Trasplante de Hígado/efectos adversos , Masculino , Infiltración Neutrófila/efectos de los fármacos , Ratas , Ratas Endogámicas Lew , Factor de Necrosis Tumoral alfa/biosíntesis
8.
Am J Transplant ; 10(4): 763-772, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20199500

RESUMEN

I/R injury is a major deleterious factor of successful kidney transplantation (KTx). Carbon monoxide (CO) is an endogenous gaseous regulatory molecule, and exogenously delivered CO in low concentrations provides potent cytoprotection. This study evaluated efficacies of CO exposure to excised kidney grafts to inhibit I/R injury in the pig KTx model. Porcine kidneys were stored for 48 h in control UW or UW supplemented with CO (CO-UW) and autotransplanted in a 14-day follow-up study. In the control UW group, animal survival was 80% (4/5) with peak serum creatinine levels of 12.0 +/- 5.1 mg/dL. CO-UW showed potent protection, and peak creatinine levels were reduced to 6.9 +/- 1.4 mg/dL with 100% (5/5) survival without any noticeable adverse event or abnormal COHb value. Control grafts at 14 days showed significant tubular damages, focal fibrotic changes and numerous infiltrates. The CO-UW group showed significantly less severe histopathological changes with less TGF-beta and p-Smad3 expression. Grafts in CO-UW also showed significantly lower early mRNA levels for proinflammatory cytokines and less lipid peroxidation. CO in UW provides significant protection against renal I/R injury in the porcine KTx model. Ex vivo exposure of kidney grafts to CO during cold storage may therefore be a safe strategy to reduce I/R injury.


Asunto(s)
Monóxido de Carbono/administración & dosificación , Trasplante de Riñón , Daño por Reperfusión/prevención & control , Animales , Western Blotting , Carboxihemoglobina/metabolismo , Modelos Animales de Enfermedad , Supervivencia de Injerto , Malondialdehído/metabolismo , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Soluciones , Porcinos
9.
Am J Transplant ; 9(12): 2716-26, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19845582

RESUMEN

Xenotransplantation of porcine islets into diabetic non-human primates is characterized by (i) an initial massive graft loss possibly due to the instant blood-mediated inflammatory reaction and (ii) the requirement of intensive, clinically unfriendly immunosuppressive therapy. We investigated whether the transgenic expression of a human complement-regulatory protein (hCD46) on porcine islets would improve the outcome of islet xenotransplantation in streptozotocin-induced diabetic Cynomolgus monkeys. Immunosuppression consisted of thymoglobulin, anti-CD154 mAb for costimulation blockade, and mycophenolate mofetil. Following the transplantation of islets from wild-type pigs (n = 2) or from 1,3-galactosyltransferase gene-knockout pigs (n = 2), islets survived for a maximum of only 46 days, as evidenced by return to hyperglycemia and the need for exogenous insulin therapy. The transplantation of islets from hCD46 pigs resulted in graft survival and insulin-independent normoglycemia in four of five monkeys for the 3 months follow-up of the experiment. One normalized recipient, selected at random, was followed for >12 months. Inhibition of complement activation by the expression of hCD46 on the pig islets did not substantially reduce the initial loss of islet mass, rather was effective in limiting antibody-mediated rejection. This resulted in a reduced need for immunosuppression to preserve a sufficient islet mass to maintain normoglycemia long-term.


Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Experimental/fisiopatología , Trasplante de Islotes Pancreáticos/métodos , Proteína Cofactora de Membrana/genética , Trasplante Heterólogo , Animales , Animales Modificados Genéticamente , Diabetes Mellitus Experimental/cirugía , Femenino , Macaca fascicularis , Masculino , Porcinos
10.
Acta Physiol (Oxf) ; 197(4): 313-20, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19438844

RESUMEN

AIM: To examine the effects of low-volume muscle endurance training on muscle oxidative capacity, endurance and strength of the forearm muscle during 21-day forearm immobilization (IMM-21d). METHODS: The non-dominant arm (n = 15) was immobilized for 21 days with a cast and assigned to an immobilization-only group (Imm-group; n = 7) or an immobilization with training group (Imm+Tr-group; n = 8). Training comprised dynamic handgrip exercise at 30% of pre-intervention maximal voluntary contraction (MVC) at 1 Hz until exhaustion, twice a week during the immobilization period. The duration of each exercise session was 51.7 +/- 3.4 s (mean +/- SE). Muscle oxidative capacity was evaluated by the time constant for phosphocreatine recovery (tau(off)PCr) after a submaximal handgrip exercise using (31)phosphorus-magnetic resonance spectroscopy. An endurance test was performed at 30% of pre-intervention MVC, at 1 Hz, until exhaustion. RESULTS: tau(off)PCr was significantly prolonged in the Imm-group after 21 days (42.0 +/- 2.8 and 64.2 +/- 5.1 s, pre- and post-intervention respectively; P < 0.01) but did not change for the Imm+Tr-group (50.3 +/- 3.0 and 48.8 +/- 5.0 s, ns). Endurance decreased significantly for the Imm-group (55.1 +/- 5.1 and 44.7 +/- 4.6 s, P < 0.05) but did not change for the Imm+Tr-group (47.9 +/- 3.0 and 51.7 +/- 4.0 s, ns). MVC decreased similarly in both groups (P < 0.01). CONCLUSIONS: Twice-weekly muscle endurance training sessions, each lasting approx. 50 s, effectively prevented a decrease in muscle oxidative capacity and endurance; however, there was no effect on MVC decline with IMM-21d.


Asunto(s)
Ejercicio Físico/fisiología , Antebrazo , Inmovilización/fisiología , Contracción Muscular/fisiología , Músculo Esquelético/metabolismo , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Adulto , Prueba de Esfuerzo , Antebrazo/anatomía & histología , Antebrazo/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Fuerza Muscular/fisiología , Factores de Tiempo , Adulto Joven
12.
Am J Transplant ; 7(10): 2279-90, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17711551

RESUMEN

Carbon monoxide (CO) provides protection against oxidative stress via anti-inflammatory and cytoprotective actions. In this study, we tested the hypothesis that a low concentration of exogenous (inhaled) CO would protect transplanted lung grafts from cold ischemia-reperfusion injury via a mechanism involving the mitogen-activated protein kinase (MAPK) signaling pathway. Lewis rats underwent orthotopic syngeneic or allogeneic left lung transplantation with 6 h of cold static preservation. Exposure of donors and recipients (1 h before and then continuously post-transplant) to 250 ppm CO resulted in significant improvement in gas exchange, reduced leukocyte sequestration, preservation of parenchymal and endothelial cell ultrastructure and reduced inflammation compared to animals exposed to air. The beneficial effects of CO were associated with p38 MAPK phosphorylation and were significantly prevented by treatment with a p38 MAPK inhibitor, suggesting that CO's efficacy is at least partially mediated by activation of p38 MAPK. Furthermore, CO markedly suppressed inflammatory events in the contralateral naïve lung. This study demonstrates that perioperative exposure of donors and recipients to CO at a low concentration can impart potent anti-inflammatory and cytoprotective effects in a clinically relevant model of lung transplantation and support further evaluation for potential clinical use.


Asunto(s)
Monóxido de Carbono/uso terapéutico , Trasplante de Pulmón/fisiología , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Daño por Reperfusión/prevención & control , Animales , Antiinflamatorios/uso terapéutico , Ciclooxigenasa 2/genética , Interleucinas/genética , Pulmón/ultraestructura , Masculino , Neutrófilos/fisiología , Óxido Nítrico Sintasa de Tipo II/genética , ARN Mensajero/genética , Ratas , Ratas Endogámicas Lew , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Trasplante Homólogo , Trasplante Isogénico
13.
Am J Transplant ; 6(10): 2243-55, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16827783

RESUMEN

Carbon monoxide (CO), a byproduct of heme catalysis, was shown to have potent cytoprotective and anti-inflammatory effects. In vivo recipient CO inhalation at low concentrations prevented ischemia/reperfusion (I/R) injury associated with small intestinal transplantation (SITx). This study examined whether ex vivo delivery of CO in University of Wisconsin (UW) solution could ameliorate intestinal I/R injury. Orthotopic syngenic SITx was performed in Lewis rats after 6 h cold preservation in control UW or UW that was bubbled with CO gas (0.1-5%) (CO-UW). Recipient survival with intestinal grafts preserved in 5%, but not 0.1%, CO-UW improved to 86.7% (13/15) from 53% (9/17) with control UW. At 3 h after SITx, grafts stored in 5% CO-UW showed improved intestinal barrier function, less mucosal denudation and reduced inflammatory mediator upregulation compared to those in control UW. Preservation in CO-UW associated with reduced vascular resistance (end preservation), increased graft cyclic guanosine monophosphate levels (1 h), and improved graft blood flow (1 h). Protective effects of CO-UW were reversed by ODQ, an inhibitor of soluble guanylyl cyclase. In vitro culture experiment also showed better preservation of vascular endothelial cells with CO-UW. The study suggests that ex vivo CO delivery into UW solution would be a simple and innovative therapeutic strategy to prevent transplant-induced I/R injury.


Asunto(s)
Antimetabolitos/farmacología , Monóxido de Carbono/farmacología , Intestino Delgado/irrigación sanguínea , Intestino Delgado/trasplante , Soluciones Preservantes de Órganos/farmacología , Trasplante de Órganos/efectos adversos , Daño por Reperfusión/prevención & control , Adenosina/química , Adenosina/farmacocinética , Adenosina/farmacología , Alopurinol/química , Alopurinol/farmacocinética , Alopurinol/farmacología , Animales , Antimetabolitos/análisis , Antimetabolitos/farmacocinética , Monóxido de Carbono/análisis , Monóxido de Carbono/farmacocinética , Modelos Animales de Enfermedad , Glutatión/química , Glutatión/farmacocinética , Glutatión/farmacología , Supervivencia de Injerto/efectos de los fármacos , Insulina/química , Insulina/farmacocinética , Insulina/farmacología , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/ultraestructura , Intestino Delgado/metabolismo , Masculino , Microscopía Electrónica de Transmisión , Preservación de Órganos , Soluciones Preservantes de Órganos/química , Soluciones Preservantes de Órganos/farmacocinética , Rafinosa/química , Rafinosa/farmacocinética , Rafinosa/farmacología , Ratas , Ratas Endogámicas Lew , Daño por Reperfusión/etiología , Daño por Reperfusión/metabolismo , Resultado del Tratamiento
14.
Neurology ; 67(2): 280-7, 2006 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-16864821

RESUMEN

BACKGROUND: Multifocal motor neuropathy (MMN) is often misdiagnosed as motor neuron disease, especially when overt evidence of conduction block (CB) is lacking. Activity-dependent CB (ADCB), defined as transient CB induced by brief exercise, has been recently found in MMN but not in ALS. METHODS: To test the diagnostic utility of ADCB for differentiating MMN from ALS, the authors recorded the compound muscle action potentials (CMAPs) from small hand muscles by magnetically stimulating nerve roots before and after 1 minute of maximal voluntary contraction (magnetic fatigue test). They examined nine patients with MMN with unequivocal clinical responses to IV immunoglobulins (IVIgs), yet lacked CB according to the conventional criteria. RESULTS: Six MMN patients had postexercise CB/temporal dispersion maximum in the immediate postexercise period. ADCB in an MMN patient improved after IVIg. Further analysis revealed that prolongation of the duration from the onset to the positive peak of the CMAP was the most sensitive indicator for MMN, presumably because the phase cancellation obscures the abnormalities of the other parameters. CONCLUSION: The magnetic fatigue test is useful in detecting mild conduction block presumably located in a proximal nerve segment in patients with multifocal motor neuropathy who do not fulfill its conventional electrodiagnostic criteria.


Asunto(s)
Enfermedades Desmielinizantes/diagnóstico , Prueba de Esfuerzo/métodos , Magnetismo , Debilidad Muscular/diagnóstico , Bloqueo Nervioso/métodos , Conducción Nerviosa , Polineuropatías/diagnóstico , Adulto , Anciano , Enfermedades Desmielinizantes/complicaciones , Diagnóstico Diferencial , Estimulación Eléctrica/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de la Neurona Motora/diagnóstico , Fatiga Muscular , Debilidad Muscular/complicaciones , Polineuropatías/complicaciones , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Síndrome
15.
Neurology ; 65(7): 1132-4, 2005 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-16217076

RESUMEN

In a new family with X-linked congenital autophagic vacuolar myopathy (AVM), seven affected boys presented with congenital hypotonia, dyspnea, and dysphagia with delayed motor milestones. Muscle pathology revealed autophagic vacuoles with sarcolemmal features, multilayered basal lamina with marked sarcolemmal deposition of C5-9 membrane attack complex and calcium, histologically indistinguishable from childhood-onset X-linked myopathy with excessive autophagy (XMEA). Haplotype analysis suggests that this new AVM and XMEA may be allelic despite different clinical presentations.


Asunto(s)
Autofagia/genética , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Músculo Esquelético/patología , Enfermedades Musculares/diagnóstico , Enfermedades Musculares/genética , Antígenos de Protozoos/genética , Antígenos de Superficie/genética , Huesos/anomalías , Niño , Análisis Mutacional de ADN , Discapacidades del Desarrollo/diagnóstico , Discapacidades del Desarrollo/genética , Discapacidades del Desarrollo/fisiopatología , Enfermedades Genéticas Ligadas al Cromosoma X/fisiopatología , Ligamiento Genético , Pruebas Genéticas , Haplotipos/genética , Humanos , Lactante , Recién Nacido , Escala de Lod , Masculino , Debilidad Muscular/diagnóstico , Debilidad Muscular/genética , Debilidad Muscular/fisiopatología , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatología , Atrofia Muscular/diagnóstico , Atrofia Muscular/genética , Atrofia Muscular/fisiopatología , Enfermedades Musculares/congénito , Linaje , Fenotipo , Sarcolema/metabolismo , Sarcolema/patología , Vacuolas/genética , Vacuolas/metabolismo , Vacuolas/patología
16.
Langmuir ; 21(19): 8913-7, 2005 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-16142978

RESUMEN

A novel and facile preparation method for layer-by-layer (LbL) self-assembled films incorporating quantum dots (QDs) and having intense photoluminescence (PL) from blue to red is presented. Functional sol-gel-derived glass layers prepared by the hydrolysis of 3-aminopropyltrimethoxysilane (APS) or 3-mercaptopropyltrimethoxysilane (MPS) have been used as a linkage between QD layers. Absorption, PL spectroscopy, transmission electron microscopy, and atomic force microscopy were employed for characterization, which revealed that the QDs in the prepared films had a nearly close-packed coverage and were not aggregated. The PL efficiencies of the QDs (CdTe or ZnSe, both are thioglycolic acid-stabilized) dispersed in the films were roughly half that of the initial colloidal solutions but reached 24% before a refractive index correction. The thickness of the red-emitting film with 10 CdTe QD layers was approximately 50 nm. The concentration of QDs in the film derived from the first absorption peak was approximately 0.01 M. Because the PL starts to show a red shift, the obtained concentration is practically the ultimate one in the glass matrix. The mercapto, amino, and carboxyl groups play important roles in LbL self-assembling processes.


Asunto(s)
Compuestos de Cadmio/química , Vidrio/química , Membranas Artificiales , Puntos Cuánticos , Compuestos de Selenio/química , Telurio/química , Compuestos de Zinc/química , Hidrólisis , Luminiscencia , Compuestos de Organosilicio , Tamaño de la Partícula , Fotoquímica , Propilaminas/química , Silanos/química , Compuestos de Sulfhidrilo/química , Propiedades de Superficie
17.
Cereb Cortex ; 15(5): 588-93, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15342437

RESUMEN

Unilateral hand movements are accompanied by a transient decrease in corticospinal (CS) excitability of muscles in the opposite hand. However, the rules that govern this phenomenon are not completely understood. We measured the amplitude of motor evoked potentials (MEP) in the left first dorsal interosseus (FDI) elicited by transcranial magnetic stimulation (TMS) of the primary motor cortex in order to assess CS excitability changes that preceded eight possible combinations of unilateral and bilateral index finger movements with different right hand positions. Left FDI MEP amplitude (MEP(Left FDI)) increased when this muscle acted as an agonist and tended to decrease when it was an antagonist. Additionally, MEP(Left FDI) decreased substantially before right index finger abduction (a movement mediated by the right FDI) when both hands were lying flat (a movement mirroring left index finger abduction) but not when the right hand was turned at 90 degrees or flat with the palm up. Therefore, CS excitability of the resting FDI was differentially modulated depending on the direction of the opposite index finger movement, regardless of muscles engaged in the task. These results indicate that inhibitory interactions preceding unilateral finger movements are determined by movement kinematics possibly to counteract the default production of mirror motions.


Asunto(s)
Potenciales Evocados Motores/fisiología , Dedos/fisiología , Corteza Motora/fisiología , Movimiento/fisiología , Inhibición Neural/fisiología , Tractos Piramidales/fisiología , Volición/fisiología , Adulto , Fenómenos Biomecánicos/métodos , Femenino , Humanos , Masculino , Neuronas/fisiología , Desempeño Psicomotor/fisiología
18.
J Phys Chem B ; 109(38): 17855-60, 2005 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-16853290

RESUMEN

CdTe nanocrystals (NCs, green- and red-emitting) prepared by an aqueous method were embedded into transparent glass films (15-20 microm thick) using a sol-gel method. Photodegradation of the NCs in the films due to UV irradiation (365 nm) was investigated quantitatively by measuring the PL efficiency as a function of the irradiation time for various irradiation intensities at several temperatures. Since CdTe NCs prepared by an aqueous method incorporate sulfur atoms from the surfactant (thioglycolic acid) during prolonged reflux in an alkaline region, the surface of red-emitting NCs (3.9 nm phi) is much more sulfur rich than that of green-emitting ones (2.6 nm phi), as previously reported. Due to this composition difference, the degradation behaviors of the two types of NCs differ significantly. The photodegradation of green-emitting glass films depended linearly on the irradiation intensity, whereas that of red-emitting ones showed a quadratic dependence. The activation energies of the photodegradation for both types of films were similar, 304 +/- 9 and 288 +/- 7 meV/particle, respectively. The NCs in the film were more than 2 orders of magnitude more robust than those in colloidal solutions. Comparison of the degradation of the glass films in air and in an Ar atmosphere revealed that the main mechanism of the photodegradation of the green-emitting NCs was oxidization from the first electronically excited state. The mechanism of the red-emitting NCs was not oxidization but a surface change probably related to a surfactant reaction.


Asunto(s)
Cadmio , Vidrio , Telurio , Cadmio/efectos de la radiación , Cinética , Modelos Moleculares , Nanotecnología , Fotólisis , Telurio/efectos de la radiación , Termodinámica
19.
Am J Surg Pathol ; 28(5): 658-69, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15105656

RESUMEN

RATIONALE AND DESIGN: The accuracy of a prospective histopathologic diagnosis of rejection and recurrent hepatitis C (HCV) was determined in 48 HCV RNA-positive liver allograft recipients enrolled in an "immunosuppression minimization protocol" between July 29, 2001 and January 24, 2003. Prospective entry of all pertinent treatment, laboratory, and histopathology results into an electronic database enabled a retrospective analysis of the accuracy of histopathologic diagnoses and the pathophysiologic relationship between recurrent HCV and rejection. RESULTS: Time to first onset of acute rejection (AR) (mean, 107 days; median, 83 days; range, 7-329 days) overlapped with the time to first onset of recurrent HCV (mean, 115 days; median, 123 days; range, 22-315 days), making distinction between the two difficult. AR and chronic rejection (CR) with and without co-existent HCV showed overlapping but significantly different liver injury test profiles. One major and two minor errors occurred (positive predictive values for AR = 91%; recurrent HCV = 100%); all involved an overdiagnosis of AR in the context of recurrent HCV. Retrospective analysis of the mistakes showed that major errors can be avoided altogether and the impact of unavoidable minor errors can be minimized by strict adherence to specific histopathologic criteria, close clinicopathologic correlation including examination of HCV RNA levels, and a conservative approach to the use of additional immunosuppression. In addition, histopathologic diagnoses of moderate and severe AR and CR were associated with relatively low HCV RNA levels, whereas relatively high HCV RNA levels were associated with a histopathologic diagnosis of hepatitis alone, particularly the cholestatic variant of HCV. CONCLUSIONS: Liver allograft biopsy interpretation can rapidly and accurately distinguish between recurrent HCV and AR/CR. In addition, the histopathologic observations suggest that the immune mechanism responsible for HCV clearance overlap with those leading to significant rejection.


Asunto(s)
Rechazo de Injerto/diagnóstico , Hepacivirus/aislamiento & purificación , Hepatitis C/diagnóstico , Trasplante de Hígado , Enfermedad Aguda , Adulto , Anciano , Biopsia , Enfermedad Crónica , Femenino , Rechazo de Injerto/prevención & control , Hepacivirus/genética , Hepatitis C/etiología , Humanos , Huésped Inmunocomprometido , Inmunosupresores/uso terapéutico , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , ARN Viral/análisis , Recurrencia , Reproducibilidad de los Resultados , Estudios Retrospectivos
20.
Gut ; 52(9): 1278-85, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12912858

RESUMEN

BACKGROUND: Intestinal transplantation provokes an intense inflammatory response within the graft muscularis that causes intestinal ileus. We hypothesised that endogenously produced anti-inflammatory substances could be utilised as novel therapeutics. Therefore, we tested the protective effects of inhaled carbon monoxide (CO) and an endogenous haeme oxygenase 1 (HO-1) anti-inflammatory mediator on transplant induced inflammatory responses and intestinal ileus in the rat. METHODS: Gastrointestinal transit of non-absorbable FITC labelled dextran and in vitro jejunal circular muscle contractions were measured in controls and syngeneic orthotopic transplanted animals with and without CO inhalation (250 ppm for 25 hours). Inflammatory mRNAs for interleukin (IL)-6, IL-1beta, tumour necrosis factor alpha (TNF-alpha), intercellular adhesion molecule 1 (ICAM-1), inducible nitric oxide (iNOS), cyclooxygenase 2 (COX-2), and IL-10 were quantified by real time reverse transcriptase-polymerase chain reaction and HO-1 by northern blot. Histochemical stains characterised neutrophil infiltration and enterocyte apoptosis. RESULTS: Transplantation delayed transit and suppressed jejunal circular muscle contractility. Transplantation induced dysmotility was significantly improved by CO inhalation. Transplantation initiated a significant upregulation in IL-6, IL-1beta, TNF-alpha, ICAM-1, iNOS, COX-2, and HO-1 mRNAs with the graft muscularis. CO inhalation significantly decreased expression of IL-6, IL-1beta, iNOS, and COX-2 mRNAs. CO also significantly decreased serum nitrite levels (iNOS activity). CONCLUSIONS: CO inhalation significantly improved post-transplant motility and attenuated the inflammatory cytokine milieu in the syngeneic rat transplant model. Thus clinically providing CO, the end product of the anti-inflammatory HO-1 pathway, may prove to be an effective therapeutic adjunct for clinical small bowel transplantation.


Asunto(s)
Monóxido de Carbono/administración & dosificación , Motilidad Gastrointestinal/inmunología , Intestino Delgado/trasplante , Animales , Betanecol/farmacología , Northern Blotting , Ciclooxigenasa 2 , Citocinas/metabolismo , Motilidad Gastrointestinal/efectos de los fármacos , Motilidad Gastrointestinal/fisiología , Tránsito Gastrointestinal/inmunología , Hemo Oxigenasa (Desciclizante)/metabolismo , Hemo-Oxigenasa 1 , Inflamación/etiología , Inflamación/fisiopatología , Molécula 1 de Adhesión Intercelular/metabolismo , Interleucina-1/metabolismo , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Intestino Delgado/inmunología , Intestino Delgado/fisiología , Isoenzimas/metabolismo , Masculino , Contracción Muscular/efectos de los fármacos , Óxido Nítrico Sintasa/metabolismo , Prostaglandina-Endoperóxido Sintasas/metabolismo , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Necrosis Tumoral alfa/metabolismo
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