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5.
Scand J Rheumatol ; 47(5): 392-399, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29916287

RESUMEN

OBJECTIVE: Despite aggressive therapeutic regimens, diffuse alveolar haemorrhage (DAH) is still associated with a high mortality rate in systemic lupus erythematosus (SLE). This study was carried out in patients with SLE-associated DAH with a focus on their therapeutic modality. METHOD: A retrospective review was performed in 839 Han Chinese lupus patients hospitalized for their DAH manifestation from May 2006 to December 2016. RESULTS: There were 24 episodes in 17 cases (2.0% incidence), 15 females and two males aged 19-67 years (mean ± sd 38.2 ± 15.1 years). High disease activity [Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) 12-31, 19.8 ± 5.6] was found at the onset of DAH. All patients were treated with high-dose corticosteroid, followed by pulse methylprednisolone (70.6%), plasmapheresis (41.2%), pulse cyclophosphamide (35.3%), and rituximab (23.5%). Six patients (35.3%), including three with extracorporeal membrane oxygenation, died owing to acute respiratory failure. All patients receiving rituximab treatment survived with a follow-up period of 12-58 months (40.8 ± 21.1 months), and no further relapse was noted in three cases with a history of recurrent DAH episodes. In addition, there was a significant decrease in their lupus activity (SLEDAI-2K 21.5 ± 6.0 to 6.3 ± 1.7, p = 0.0286). CONCLUSION: In this single-centre series with SLE-associated DAH in Han Chinese patients, a beneficial effect of rituximab therapy was observed.


Asunto(s)
Hemorragia/etiología , Enfermedades Pulmonares/etiología , Lupus Eritematoso Sistémico/complicaciones , Adulto , Anciano , Pueblo Asiatico , Oxigenación por Membrana Extracorpórea/métodos , Femenino , Glucocorticoides/uso terapéutico , Hemorragia/mortalidad , Hemorragia/terapia , Humanos , Factores Inmunológicos/uso terapéutico , Enfermedades Pulmonares/mortalidad , Enfermedades Pulmonares/terapia , Lupus Eritematoso Sistémico/mortalidad , Lupus Eritematoso Sistémico/terapia , Masculino , Persona de Mediana Edad , Plasmaféresis/métodos , Alveolos Pulmonares/patología , Recurrencia , Estudios Retrospectivos , Rituximab/uso terapéutico , Análisis de Supervivencia , Taiwán , Adulto Joven
6.
Eur Rev Med Pharmacol Sci ; 22(9): 2588-2597, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29771442

RESUMEN

OBJECTIVE: The aim of this study was to investigate the role of microRNA-222 (miR-222) in osteosarcoma (OS), and to further explore the potential molecular mechanism. PATIENTS AND METHODS: We measured the level of miR-222 in OS tissues and cell lines using quantitative Real-time polymerase chain reaction. Synthesized miR-222 mimics or inhibitors were obtained to up-regulate or down-regulate the expression of miR-222 in U2OS or Saos2 cells. Cell counting kit-8 (CCK8) and colony formation assay were employed to detect the ability of cell proliferation, and transwell assay was used to confirm the ability of cell invasion. Furthermore, luciferase assay and Western blot were applied to verify the target of miR-222 in OS. RESULTS: The level of miR-222 in OS tumor tissue samples was significantly lower than that in normal group. Over-expression of miR-222 decreased cell proliferation and invasion in U2OS cells while knockdown of miR-222 promoted cell growth and metastasis in Saos2 cells. Furthermore, YWHAG was found to be a candidate target of miR-222 using several databases. Elevated level of miR-222 inhibited YWHAG expression while reduced miR-222 promoted YWHAG expression. Also, up-regulation of YWHAG restored the inhibiting effect of miR-222 mimics. CONCLUSIONS: We identified for the first time that the expression level of miR-222 was reduced in OS tissues as well as in OS cell lines. miR-222 could inhibit cell proliferation and invasion via down-regulating YWHAG. These data could provide a potential target for the biological treatment of OS.


Asunto(s)
Proteínas 14-3-3/metabolismo , Neoplasias Óseas/metabolismo , Movimiento Celular , Proliferación Celular , MicroARNs/metabolismo , Osteosarcoma/metabolismo , Proteínas 14-3-3/genética , Regiones no Traducidas 3' , Sitios de Unión , Neoplasias Óseas/genética , Neoplasias Óseas/patología , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Humanos , MicroARNs/genética , Invasividad Neoplásica , Osteosarcoma/genética , Osteosarcoma/secundario , Transducción de Señal
8.
Clin Exp Rheumatol ; 33(6): 839-43, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26315300

RESUMEN

OBJECTIVES: Selectively targeting signalling pathways represents a promising pharmacological approach in rheumatoid arthritis (RA). Abundant levels of epidermal growth factor receptor (EGFR) are expressed in the synovial lining layers, and the anti-arthritis effect of erlotinib and lapatinib, small-molecule EGFR tyrosine kinase inhibitors (TKIs), has been demonstrated through the systemic administration on experimental arthritis models. Nevertheless, their therapeutic responses by the intra-articular (i.a.) route remain to be explored in rheumatoid joint. METHODS: The administration of an EGFR TKI (a gefitinib analogue) was explored in two in vivo models of collagen-induced arthritis (CIA) and in vitro experiments by using synovial fibroblasts (SF) from RA patients and CIA rats. RESULTS: There was a significant reduction of arthritis scores in CIA mice receiving the daily intraperitoneal injection. After the onset of arthritis in CIA rats, ankle joints receiving a single i.a. injection had significant lower articular indexes with reduced synovial inflammation, pannus formation and erosion on cartilage and bone as well as total histological scores by histopathological analyses. In CIASF or RASF, upon in vitro human EGF stimulation, there was a dose-dependent increase in cell proliferation and Akt activation with suppressed responses under the EGFR TKI treatment. CONCLUSIONS: These findings demonstrate the effect of i.a. injection of an EGFR TKI on amelioration of rheumatoid joint through the suppression of synovial inflammation, pannus formation and erosion on cartilage and bone in experimental arthritis, implicating targeting the i.a. EGFR signalling transduction as a pharmacological strategy.


Asunto(s)
Artritis Reumatoide , Receptores ErbB/antagonistas & inhibidores , Quinazolinas/farmacología , Membrana Sinovial , Animales , Artritis Experimental/tratamiento farmacológico , Artritis Experimental/metabolismo , Artritis Experimental/patología , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/metabolismo , Artritis Reumatoide/patología , Técnicas de Cultivo de Célula , Relación Dosis-Respuesta a Droga , Monitoreo de Drogas , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Gefitinib , Humanos , Inyecciones Intraarticulares , Ratones , Inhibidores de Proteínas Quinasas/farmacología , Ratas , Membrana Sinovial/efectos de los fármacos , Membrana Sinovial/metabolismo , Membrana Sinovial/patología , Resultado del Tratamiento
9.
Pathol Biol (Paris) ; 63(1): 11-6, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25468491

RESUMEN

BACKGROUND: Lipopolysaccharide (LPS) has pro-inflammatory properties. This study was conducted to determine whether the LPS induced pro-inflammatory response in a model of mastitis and in mouse mammary epithelial cells (MEC). METHODS: To investigate the effects of LPS in vivo, 50 µL of a solution of LPS (20 ng/µL) were infused into the mammary glands of mice. To study the effects of LPS in vitro, MEC were exposed to LPS (20 µg/mL) for 24h. Activation of nuclear factor kB (NF-κB) and myeloperoxidase (MPO) were studied. Production of pro-inflammatory cytokines (interleukin-6 [IL-6], tumor necrosis factor-alpha [TNF-alpha], interleukin-1 beta [IL-1 beta]) and expression of osteopontin (OPN) were also evaluated. RESULTS: After LPS administration, route of NF-κB signaling is activated and the activity of MPO is increased. Furthermore, LPS increases the expression of OPN and production of TNF-alpha, IL-6 and IL-1 beta. CONCLUSIONS: Present results demonstrate that LPS induces a pro-inflammatory response in a murine model of mastitis and suggest the involvement of the NF-κB pathway and OPN.


Asunto(s)
Células Epiteliales/efectos de los fármacos , Inflamación/inducido químicamente , Lipopolisacáridos/farmacología , Glándulas Mamarias Animales/efectos de los fármacos , Mastitis/inmunología , FN-kappa B/fisiología , Osteopontina/fisiología , Animales , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Células Epiteliales/patología , Femenino , Inflamación/metabolismo , Inflamación/patología , Mediadores de Inflamación/metabolismo , Glándulas Mamarias Animales/inmunología , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología , Mastitis/metabolismo , Mastitis/patología , Ratones , Ratones Endogámicos C57BL , FN-kappa B/metabolismo , Osteopontina/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología
10.
Gene Ther ; 19(7): 752-60, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22089492

RESUMEN

Knockdown of Toll-like receptors (TLRs) is a novel therapeutic strategy in treating patients with rheumatoid arthritis (RA). We examined the effects of lentiviral vector-mediated delivery of TLR7 short hairpin RNA gene (Lt.shTLR7) on collagen-induced arthritis (CIA). After being immunized on days 0 and 7, Sprague-Dawley rats received intra-articular (i.a.) injection of Lt.shTLR7 or scramble control vector on days 7 and 10. The therapeutic effects were evaluated by measuring ankle circumferences, articular index, and radiographic and histological scores on killing on day 16. Microvessel densities, vascular endothelial growth factor (VEGF) levels, pro-inflammatory cytokine concentrations and T-cell numbers within the synovial tissues were measured. Moreover, VEGF and pro-inflammatory cytokine concentrations in culture supernatants from TLR7-transfected synovial fibroblasts (SFs) stimulated with imiquimod or endogenous ligands were examined. There were significant reduction in ankle circumferences, articular indexes, and radiographic and histological scores. Microvessel densities, VEGF concentrations, interleukin (IL)-1ß and IL-6 levels and T-cell densities within synovial tissues were significantly lower. Induction of VEGF, IL-1ß and IL-6 production from stimulated SFs was significantly suppressed. Taken together, these data demonstrate the effects of i.a. lentiviral vector-mediated delivery of shTLR7 RNA gene on inhibition of CIA, and implicate the manipulation of TLR7 as a potential therapeutic strategy in RA patients.


Asunto(s)
Artritis Experimental/terapia , ARN Interferente Pequeño/farmacología , Receptor Toll-Like 7/genética , Animales , Articulación del Tobillo/efectos de los fármacos , Artritis Experimental/patología , Citocinas/biosíntesis , Vectores Genéticos , Inyecciones Intraarticulares , Lentivirus/genética , Masculino , Microcirculación/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Membrana Sinovial/metabolismo , Factor A de Crecimiento Endotelial Vascular/análisis
11.
Am J Transplant ; 10(7): 1524-33, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20642679

RESUMEN

Infections and TLR signals at the time of transplantation have been shown to prevent the induction of tolerance, but their effect on allografts after tolerance has been established is unclear. We here report that infection with Listeria monocytogenes precipitated the loss of tolerance and the MyD88- and T cell-dependent rejection of accepted cardiac allografts in mice. This loss of tolerance was associated with increases in the numbers of graft-infiltrating macrophages and dendritic cells, as well as CD4(+)FoxP3(-) and CD8(+) T cells. Rejection was also associated with increased numbers of graft-infiltrating alloreactive as well as Listeria-reactive IFNgamma-producing T cells. Rejection of the established grafts required both IL-6 and IFNss, cytokines produced during acute Listeria infection. However, IL-6 and IFNss alone, even when present at higher concentrations than during Listeria infection, were insufficient to break tolerance, while the combination of IL-6 and IFNss was sufficient to break tolerance. These and in vitro observations that IL-6 but not IFNss enhanced T cell proliferation while IFNss but not IL-6 enhanced IFNgamma production support a hypothesis that these cytokines play nonredundant roles. In conclusion, these studies demonstrate that the proinflammatory effects of infections can induce the loss of tolerance and acute rejection of accepted allografts.


Asunto(s)
Trasplante de Corazón/efectos adversos , Trasplante de Corazón/inmunología , Listeria monocytogenes , Listeriosis/complicaciones , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Cruzamientos Genéticos , Femenino , Rechazo de Injerto/inmunología , Rechazo de Injerto/microbiología , Interferón beta/sangre , Interferón beta/fisiología , Interleucina-6/sangre , Interleucina-6/deficiencia , Depleción Linfocítica , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Tolerancia al Trasplante , Trasplante Heterotópico/métodos , Trasplante Homólogo/efectos adversos , Trasplante Homólogo/inmunología
12.
Lupus ; 19(10): 1204-9, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20515999

RESUMEN

As very few large scale publications of invasive fungal infection (IFI) have been reported in lupus patients from individual medical centers, a retrospective study was performed from 1988 to 2009 in southern Taiwan. Demographic characteristics, clinical and laboratory data, and mycological examinations were analyzed. Twenty cases with IFI were identified in 2397 patients (0.83% incidence). There were 19 females and one male with an average age of 31.8 +/- 12.6. Involved sites included eight disseminated cases, six central nervous system, four lungs, one abdomen and one soft tissue. IFI contributed to a high mortality with 10 deaths (50%), and there were no survivors for the disseminated cases and Candida-infected patients. High activity (Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) > 8) was noted in 50% of IFI episodes. The survival from IFI diagnosis to death was only 7.7 +/- 4.2 days, all in a rapid course. No statistical difference was found between survivors and non-survivors when comparing their SLEDAI. Eighty-five percent of IFI episodes under high dosages of corticosteroids therapy and 95% of patients had lupus nephritis. There was an increased risk of IFI in the lupus patients receiving high daily dosage of prednisolone therapy. Critical information from analyses of the present large series could be applied into clinical practices to reduce the morbidity and mortality in such patients.


Asunto(s)
Lupus Eritematoso Sistémico/complicaciones , Nefritis Lúpica/complicaciones , Micosis/fisiopatología , Adolescente , Adulto , Relación Dosis-Respuesta a Droga , Femenino , Glucocorticoides/administración & dosificación , Glucocorticoides/efectos adversos , Glucocorticoides/uso terapéutico , Humanos , Lupus Eritematoso Sistémico/tratamiento farmacológico , Nefritis Lúpica/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Micosis/etiología , Micosis/mortalidad , Prednisolona/administración & dosificación , Prednisolona/efectos adversos , Prednisolona/uso terapéutico , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Sobrevida , Taiwán/epidemiología , Factores de Tiempo , Adulto Joven
13.
Gene Ther ; 17(10): 1225-33, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20520649

RESUMEN

Different members of the galectin family may have inhibitory or stimulatory roles in controlling immune responses and regulating inflammatory reactions in autoimmune diseases such as rheumatoid arthritis (RA). A hypothetical model of a cross talk between galectin-1 and galectin-3 has been established in the circumstance of rheumatoid joints. As galectin-3 is a positive regulator and galectin-1 is a negative regulator of inflammation and autoimmune responses, in this study we evaluated the effects of local knockdown of galectin-3 or overexpression of galectin-1 on ameliorating collagen-induced arthritis (CIA) in rats. Lentiviral vectors encoding galectin-3 small hairpin RNA (shRNA) and galectin-1, as well as two control vectors expressing luciferase shRNA and green fluorescent protein, were individually injected intra-articularly into the ankle joints of rats with CIA, and their treatment responses were monitored by measuring the clinical, radiological and histological changes. Our results show that both knockdown of galectin-3 and overexpression of galectin-1 induced higher percentages of antigen-induced T-cell death in the lymph node cells from arthritic rats. Furthermore, these treatments significantly reduced articular index scores, radiographic scores and histological scores, accompanied with decreased T-cell infiltrates and reduced microvessel density in the ankle joints. Our findings implicate galectin-3 and galectin-1 as potential therapeutic targets for the treatment of RA.


Asunto(s)
Artritis Experimental/terapia , Galectina 1/genética , Galectina 3/genética , Vectores Genéticos/administración & dosificación , Lentivirus/genética , ARN Interferente Pequeño/genética , Animales , Artritis Experimental/patología , Artritis Reumatoide/patología , Artritis Reumatoide/terapia , Células Cultivadas , Terapia Genética/métodos , Vectores Genéticos/genética , Humanos , Inyecciones Intraarticulares , Ratas , Transfección
14.
Clin Exp Rheumatol ; 27(6): 902-6, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20149303

RESUMEN

OBJECTIVES: To analyse the characteristic features of patients with coexistence of gouty arthritis and pyarthrosis at our university hospital in southern Taiwan, an area with high prevalence of hyperuricemia and gout. METHODS: A retrospective chart review was performed for patients who had concomitant gouty and septic arthritis from July 1998 to June 2008. Clinical and laboratory data of these patients were analysed. Furthermore, a comparison was made with published cases in English literature. RESULTS: Fourteen cases with coexistence of gouty arthritis and pyarthrosis have been identified during the past 10 years. There were 13 male and 1 female, all of Han Chinese in ethnicity, with ages ranging from 45 to 85 and an average of 63.7 years. At disease presentation, there were 11 oligoarticular cases (78.6%), 2 monoarticular cases (14.3%) and 1 polyarticular case (7.1%). Ankle and knee joints were most commonly involved. Bacteriological analyses demonstrated gram-positive cocci in 12 cases, of these 10 were oxacillin-sensitive Staphylococcus aureus (71.4%). Multiple tophi deposition was noted in 13 patients (92.9%) and among them 11 patients (84.6%) had associated chronic kidney disease. CONCLUSION: Different clinical presentations and bacteriological characteristics have been identified in the present series. While the mechanisms responsible for such a coexistence remain to be elucidated, these cases underline the importance of thorough evaluation of the aspirated synovial fluid. Our report adds a novel insight into the understanding of the clinical and microbiological manifestations of such a rare concurrence of gouty and septic arthritis.


Asunto(s)
Artritis Gotosa/complicaciones , Artritis Infecciosa/complicaciones , Anciano , Anciano de 80 o más Años , Artritis Gotosa/microbiología , Artritis Gotosa/cirugía , Artritis Infecciosa/microbiología , Artritis Infecciosa/cirugía , Desbridamiento , Femenino , Humanos , Articulaciones/microbiología , Masculino , Registros Médicos , Persona de Mediana Edad , Estudios Retrospectivos , Infecciones Estafilocócicas/complicaciones , Staphylococcus aureus
15.
J Chem Phys ; 128(4): 041102, 2008 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-18247921

RESUMEN

We report a pump-probe femtosecond transient absorption spectroscopic study on the electron transfer reaction of CCl(4) in liquid ethanol. By direct observations of the presolvated electron and of the reaction transition state CCl(4) (*-), this study provides direct evidence of the resonant dissociative electron transfer (RDET) of the presolvated electron to CCl(4). Moreover, the lifetime of CCl(4) (*-) in ethanol is directly obtained from the decay kinetics and its measured value is found to be nearly identical to its gas-phase value. Hence, these results also imply that RDET can be an efficient process in an aqueous environment.


Asunto(s)
Tetracloruro de Carbono/química , Solventes/química , Espectrofotometría Ultravioleta/métodos , Transporte de Electrón , Electrones , Etanol/química , Gases , Cinética
16.
Mol Pharm ; 4(4): 624-8, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17559229

RESUMEN

The cytotoxicity of cisplatin as a very effective chemotherapeutic anticancer drug is known to arise from its capacity to damage DNA. However, the mechanism of action of cisplatin at the molecular level, in particular, the reaction dynamics of cisplatin with DNA, remains elusive, and the reason why cisplatin binds to the guanine bases rather than to S-donor ligands available in cells remains a mystery. Using time-resolved femtosecond laser spectroscopy, for the first time, we reveal the high reactivity of cisplatin with electrons and its preferential electron-transfer reaction with the DNA guanine base. The results not only provide a molecular mechanistic understanding of cisplatin in cancer therapy but may have far-reaching significance for understanding the role of polar molecules such as NH3 and NH2 in biological reactions.


Asunto(s)
Antineoplásicos/química , Cisplatino/química , ADN/química , Transporte de Electrón , Estructura Molecular , Espectrofotometría Ultravioleta , Análisis Espectral/métodos , Factores de Tiempo
17.
Br J Dermatol ; 155(6): 1201-8, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17107390

RESUMEN

BACKGROUND: Primary cutaneous amyloidosis (PCA) is a relatively common skin disorder in South America and Southeast Asia. Most cases of PCA are sporadic but familial aggregation has been reported from South America and Taiwan. The different susceptibility among ethnic groups suggests that genetic factors may play an important role in its pathogenesis. OBJECTIVES: We aimed to perform a genome-wide scan by linkage analysis across 15 families with familial primary cutaneous amyloidosis (FPCA) to map the disease gene(s) for FPCA. PATIENTS AND METHODS: A total of 15 FPCA families including 50 individuals affected with PCA were recruited. Throughout the 22 autosomes, 369 polymorphic microsatellite markers were used initially. Regions showing a LOD score > 1 identified in the initial scan were further analysed with additional markers. Two-point and multipoint linkage analysis were performed by using the LINKAGE program. Nonparametric linkage (NPL) analysis and reconstruction of haplotypes were performed with the GENEHUNTER program. RESULTS: A maximum two-point LOD score of 4.76 for the marker D5S1490 (theta = 0.10, alpha = 0.60) and a multipoint LOD score of 4.50 between D5S822 and D5S623 (alpha = 0.60) were obtained under the assumption of heterogeneity. A peak NPL score of 5.23 (P value = 0.000007) was found from D5S1490 to D5S2076. Further analysis focusing on two major families identifies a common haplotype shared by all affected individuals between D5S1490 and D5S623. To our knowledge, this is the first report of genome-wide analysis of a large number of FPCA pedigrees. CONCLUSIONS: Our study provides evidence for significant linkage to chromosome 5p13.1-q11.2 in a subset of FPCA families.


Asunto(s)
Amiloidosis/genética , Cromosomas Humanos Par 5/genética , Predisposición Genética a la Enfermedad , Enfermedades de la Piel/genética , Adolescente , Adulto , Pueblo Asiatico/genética , Niño , Familia , Femenino , Ligamiento Genético , Marcadores Genéticos , Genotipo , Humanos , Escala de Lod , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Linaje
18.
Parasite Immunol ; 28(12): 643-7, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17096643

RESUMEN

BALB/c mice are highly susceptible to African trypanosomiasis, whereas C57BL/6 mice are relatively resistant. Other investigators have reported that the synthesis of IgG antibodies to purified membrane form of variant surface glycoprotein (mfVSG) of Trypanosoma brucei is CD1 restricted. In this study, we examine the role of the CD1d/NKT cell pathway in susceptibility and resistance of mice to infection by African trypanosomes. Administration of anti-CD1d antibodies to Trypanosoma congolense-infected BALB/c mice neither affects the parasitemia nor the survival time. Correspondingly, CD1d(-/-) and CD1d(+/+) BALB/c mice infected with T. congolense or T. brucei show no differences in either parasitaemia or survival time. The course of disease in relative resistant C57BL/6 mice infected with T. congolense is also not affected by the absence of CD1d. Parasitaemia, survival time, and plasma levels of IgG2a and IgG3 parasite-specific antibodies in infected CD1d(-/-) C57BL/6 are not different from those of infected CD1d(+/+) C57BL/6 mice. We conclude that CD1d-restricted immune responses do not play an important role in susceptibility/resistance of mice infected with virulent African trypanosomes. We speculate that virulent trypanosomes have an evasion mechanism that prevents the induction of a parasite-specific, CD1d-restricted immune response by the host.


Asunto(s)
Presentación de Antígeno , Antígenos CD1/inmunología , Trypanosoma brucei brucei/inmunología , Trypanosoma congolense/inmunología , Tripanosomiasis Africana/inmunología , Animales , Antígenos CD1d , Susceptibilidad a Enfermedades , Humanos , Células Asesinas Naturales/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Parasitemia/inmunología , Parasitemia/mortalidad , Parasitemia/parasitología , Trypanosoma brucei brucei/patogenicidad , Trypanosoma congolense/patogenicidad , Tripanosomiasis Africana/mortalidad , Tripanosomiasis Africana/parasitología
19.
Am J Transplant ; 6(10): 2282-91, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16970798

RESUMEN

In many experimental models, heart, pancreas and kidney allografts are accepted long-term following costimulation-targeting therapies, whereas skin, lung and intestine resist the induction of tolerance under the same regimens. We noted that a common feature of the resistant organs is their constant exposure to commensal microbes and hypothesized that these microorganisms may stimulate Toll-like receptors (TLRs), promote alloresponses and prevent tolerance induction. This hypothesis prompts the predictions that TLR engagement at the time of transplantation should avert tolerance to heart allografts in animals treated with costimulation-targeting therapies, whereas inhibition of TLR signaling should promote tolerance to skin allografts under the same conditions. Indeed, engagement of a single TLR was sufficient to prevent anti-CD154-mediated long-term cardiac allograft acceptance and correlated with abolished intragraft recruitment of CD4+/FoxP3+ regulatory T cells and the development of linked-suppression. Conversely, a lack of donor and recipient MyD88-dependent signaling led to successful skin allograft acceptance in anti-CD154-treated animals. Thus, the status of TLR signaling contributes to the resistance versus susceptibility of organs to transplantation tolerance.


Asunto(s)
Rechazo de Injerto/inmunología , Trasplante de Corazón/inmunología , Tolerancia Inmunológica/fisiología , Trasplante de Piel/inmunología , Receptores Toll-Like/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Autoanticuerpos/inmunología , Linfocitos T CD4-Positivos/inmunología , Ligando de CD40/inmunología , Linfocitos T CD8-positivos/inmunología , Citocinas/genética , Modelos Animales de Enfermedad , Estudios de Seguimiento , Rechazo de Injerto/prevención & control , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , ARN Mensajero/genética , Factores de Tiempo , Receptores Toll-Like/antagonistas & inhibidores , Trasplante Heterotópico , Trasplante Homólogo
20.
J Chem Phys ; 124(24): 241102, 2006 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-16821962

RESUMEN

Replacement of thymidine in DNA by bromodeoxyuridine (BrdU) has long been known to enhance DNA damage and cell death induced by ionizing/UV radiation, but the mechanism of action of BrdU at the molecular level is poor understood. Using time-resolved femtosecond laser spectroscopy, we obtain the real-time observation of the transition state of the ultrafast electron transfer (ET) reaction of BrdU with the precursor to the hydrated electron, which is a general product in ionizing/UV radiation. The results show that the ET reaction is completed within 0.2 picosecond (ps) after the electronic excitation, leading to the formation of a transition state BrdU*- with a lifetime of approximately 1.5 ps that then dissociates into Br- and a high reactive radical dU*. The present results can greatly enhance our understanding not only of the mechanism of BrdU as a radio-/photosensitizer but of the role of prehydrated electrons in electron-initiated processes in biological and environmental systems.


Asunto(s)
Bromodesoxiuridina/química , Bromodesoxiuridina/farmacología , Química Física/métodos , ADN/química , Fármacos Sensibilizantes a Radiaciones/química , Fármacos Sensibilizantes a Radiaciones/farmacología , Muerte Celular , Daño del ADN , Electrones , Modelos Químicos , Espectrofotometría , Timidina/química , Factores de Tiempo , Rayos Ultravioleta
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