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1.
Mol Psychiatry ; 23(10): 2007-2017, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29203848

RESUMEN

Conventional antidepressant medications, which act on monoaminergic systems, display significant limitations, including a time lag of weeks to months and low rates of therapeutic efficacy. GLYX-13 is a novel glutamatergic compound that acts as an N-methyl-D-aspartate (NMDA) modulator with glycine-like partial agonist properties; like the NMDA receptor antagonist ketamine GLYX-13 produces rapid antidepressant actions in depressed patients and in preclinical rodent models. However, the mechanisms underlying the antidepressant actions of GLYX-13 have not been characterized. Here we use a combination of neutralizing antibody (nAb), mutant mouse and pharmacological approaches to test the role of brain-derived neurotrophic factor-tropomyosin-related kinase B (BDNF-TrkB) signaling in the actions of GLYX-13. The results demonstrate that the antidepressant effects of GLYX-13 are blocked by intra-medial prefrontal cortex (intra-mPFC) infusion of an anti-BDNF nAb or in mice with a knock-in of the BDNF Val66Met allele, which blocks the processing and activity-dependent release of BDNF. We also demonstrate that pharmacological inhibitors of BDNF-TrkB signaling or of L-type voltage-dependent Ca2+ channels (VDCCs) block the antidepressant behavioral actions of GLYX-13. Finally, we examined the role of the Rho GTPase proteins by injecting a selective inhibitor into the mPFC and found that activation of Rac1 but not RhoA is involved in the antidepressant effects of GLYX-13. Together, these findings indicate that enhanced release of BDNF through exocytosis caused by activation of VDCCs and subsequent TrkB-Rac1 signaling is required for the rapid and sustained antidepressant effects of GLYX-13.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/efectos de los fármacos , Oligopéptidos/metabolismo , Oligopéptidos/farmacología , Animales , Antidepresivos/metabolismo , Antidepresivos/farmacología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/fisiología , Depresión/tratamiento farmacológico , Ketamina/farmacología , Masculino , Glicoproteínas de Membrana/efectos de los fármacos , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , N-Metilaspartato/antagonistas & inhibidores , Corteza Prefrontal/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor trkB/efectos de los fármacos , Receptores de N-Metil-D-Aspartato/metabolismo , Transducción de Señal/efectos de los fármacos
4.
Ann Oncol ; 24(11): 2870-5, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24013511

RESUMEN

BACKGROUND: Cigarette smoking is the major cause of lung cancer (LC). Although the time to first cigarette (TTFC) of the day is a distinct indicator of nicotine dependence, little information is available on its possible relation to LC. PATIENTS AND METHODS: This case-control study includes a total of 1572 incident LC cases and 1572 non-cancer controls visiting for the first time the Aichi Cancer Center Hospital between 2001 and 2005. We estimated the odds ratio (OR) and 95% confidence interval (CI) for TTFC using a logistic regression model after adjustment for several potential confounders. RESULTS: TTFC was inversely associated with the risk of LC. This association was consistent across histological subtypes of LC. For all LCs considered among ever smokers and after accurate allowance for smoking quantity and duration, besides other relevant covariates, compared with TTFC >60 min, the adjusted ORs were 1.08 (95% CI, 0.73-1.61) for TTFC of 31-60 min, 1.40 (0.98-2.01) for 6-30 min and 1.86 (1.28-2.71) for within 5 min (Ptrend, < 0.001). Statistically marginally significant heterogeneity by histological subtype was observed (Pheterogeneity, 0.002). CONCLUSIONS: Nicotine dependence, as indicated by the TTFC, is associated with increased risk of LC and is therefore an independent marker of exposure to tobacco smoking.


Asunto(s)
Neoplasias Pulmonares/epidemiología , Fumar , Tabaquismo/patología , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Japón/epidemiología , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Factores de Tiempo , Tabaquismo/complicaciones
5.
Anal Chem ; 84(5): 2224-31, 2012 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-22283593

RESUMEN

A crucial safety measure to be strictly observed in the operation of heavy-water nuclear power plants is the mandatory regular inspection of the concentration of deuterium penetrated into the zircaloy fuel vessels. The existing standard method requires a tedious, destructive, and costly sample preparation process involving the removal of the remaining fuel in the vessel and melting away part of the zircaloy pipe. An alternative method of orthogonal dual-pulse laser-induced breakdown spectrometry (LIBS) is proposed by employing flowing atmospheric helium gas without the use of a sample chamber. The special setup of ps and ns laser systems, operated for the separate ablation of the sample target and the generation of helium gas plasma, respectively, with properly controlled relative timing, has succeeded in producing the desired sharp D I 656.10 nm emission line with effective suppression of the interfering H I 656.28 nm emission by operating the ps ablation laser at very low output energy of 26 mJ and 1 µs ahead of the helium plasma generation. Under this optimal experimental condition, a linear calibration line is attained with practically zero intercept and a 20 µg/g detection limit for D analysis of zircaloy sample while creating a crater only 10 µm in diameter. Therefore, this method promises its potential application for the practical, in situ, and virtually nondestructive quantitative microarea analysis of D, thereby supporting the more-efficient operation and maintenance of heavy-water nuclear power plants. Furthermore, it will also meet the anticipated needs of future nuclear fusion power plants, as well as other important fields of application in the foreseeable future.

6.
Herz ; 37(2): 217-8, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21748385

RESUMEN

A 58-year-old male was referred for catheter ablation for atrial fibrillation. He was incidentally diagnosed with cor triatriatum sinister by preoperative transesophageal echocardiography and cardiovascular computed tomography. The patient has since been free from atrial fibrillation for over 24 months following successful electrical pulmonary vein isolation. The rapidly soaring number of cases undergoing catheter ablation for atrial fibrillation and imaging investigation prior to the procedure may increase the incidental detection of asymptomatic congenital heart diseases.


Asunto(s)
Fibrilación Atrial/cirugía , Corazón Triatrial/diagnóstico , Corazón Triatrial/cirugía , Fibrilación Atrial/complicaciones , Corazón Triatrial/complicaciones , Humanos , Hallazgos Incidentales , Masculino , Persona de Mediana Edad
7.
Mol Psychiatry ; 14(12): 1119-31, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19564873

RESUMEN

Glucocorticoids, the most downstream effectors of the hypothalamus-pituitary-adrenal axis, are one of main mediators of the stress reaction. Indeed, exposure to high levels of stress-triggered glucocorticoids is detrimental to brain development associated with abnormal behaviors in experimental animals and the risk of psychiatric disorders in humans. Despite the wealth of this knowledge, the cellular and molecular mechanisms underlying the detrimental effects of glucocorticoids on brain development remain unclear. Here, we show that excess glucocorticoids retard the radial migration of post-mitotic neurons during the development of the cerebral cortex, and identify an actin regulatory protein, caldesmon, as the glucocorticoids' main target. The upregulation of caldesmon expression is mediated by glucocorticoid receptor-dependent transcription of the CALD1 gene encoding caldesmon. This upregulated caldesmon negatively controls the function of myosin II, leading to changes in cell shape and migration. The depletion of caldesmon in vivo impairs radial migration. The overexpression of caldesmon also causes delayed radial migration during cortical development, mimicking the excessive glucocorticoid-induced retardation of radial migration. We conclude that an appropriate range of caldesmon expression is critical for radial migration, and that its overexpression induced by excess glucocorticoid retards radial migration during cortical development. Thus, this study provides a novel insight into the underlying mechanism of glucocorticoid-related neurodevelopmental disorders.


Asunto(s)
Movimiento Celular/efectos de los fármacos , Dexametasona/farmacología , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Glucocorticoides/farmacología , Neuronas/efectos de los fármacos , Factores de Edad , Animales , Animales Recién Nacidos , Bromodesoxiuridina/metabolismo , Proteínas de Unión a Calmodulina/genética , Proteínas de Unión a Calmodulina/metabolismo , Tamaño de la Célula/efectos de los fármacos , Células Cultivadas , Corteza Cerebral/citología , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/crecimiento & desarrollo , Corteza Cerebral/patología , Proteínas de Dominio Doblecortina , Embrión de Mamíferos , Células Madre Embrionarias/efectos de los fármacos , Femenino , Perfilación de la Expresión Génica/métodos , Proteínas Fluorescentes Verdes/genética , Humanos , Proteínas Asociadas a Microtúbulos/metabolismo , Miosina Tipo II/genética , Miosina Tipo II/metabolismo , Neuropéptidos/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Efectos Tardíos de la Exposición Prenatal/patología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Ratas , Factores de Tiempo , Transfección/métodos , Tubulina (Proteína)/metabolismo
8.
Diabetes Obes Metab ; 12(9): 790-7, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20649631

RESUMEN

AIM: The aim of this study was to evaluate the efficacy of two group-based lifestyle interventions in ameliorating the risk factors of metabolic syndrome (MS) and insulin resistance. METHODS: Ninety-eight subjects who had at least one component of MS were randomized into standard intervention (SI) (4-month intervention; n = 50) and extended intervention (EI) (10-month intervention; n = 48) groups, and 39 subjects were followed up for a control group. The effects of intervention were evaluated after 10, 22 and 34 months. RESULTS: At month 10, the standard and EI groups showed improved body mass index (BMI) (SI, -0.28; EI, -0.47; control, -0.09), high-density lipoprotein (HDL) cholesterol, fasting plasma glucose and A1c and a decreased mean number of components of MS (SI, -0.37; EI, -0.51; control, 0.08). At month 34, the effects on BMI (SI, -0.66; EI, -0.60; control, -0.05) and HDL-cholesterol were sustained for both the intervention groups. In controls, the increases in fasting plasma glucose and the mean number of components of MS from the baseline to month 34 were greater than those in the standard and EI groups. Whole body insulin sensitivity index and hepatic insulin resistance index were also improved at month 10. CONCLUSIONS: Group-based lifestyle intervention could be an efficient way to prevent MS. Its effects were sustainable, at least in part, for 2 years. These effects may be mediated by an improvement in insulin sensitivity.


Asunto(s)
Resistencia a la Insulina/fisiología , Metabolismo de los Lípidos/fisiología , Síndrome Metabólico/prevención & control , Conducta de Reducción del Riesgo , Adulto , Anciano , Femenino , Humanos , Japón/epidemiología , Masculino , Síndrome Metabólico/epidemiología , Síndrome Metabólico/etiología , Persona de Mediana Edad , Factores de Riesgo
11.
Clin Oncol (R Coll Radiol) ; 30(1): e1-e8, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29153625

RESUMEN

AIMS: The role of PD-1 (programmed cell death 1) expression on the clinical outcome of upper tract urothelial carcinoma has not yet been elucidated in detail. MATERIALS AND METHODS: PD-1 expression was immunohistochemically examined in 181 upper tract urothelial carcinoma patients who underwent radical nephroureterectomy. A part of PD-1 protein expression in the tumour periphery and tumour nest was evaluated separately. The PD-1-positive cells were counted in the area showing the highest density of PD-1 expression at a magnification of 400×. RESULTS: PD-1 staining in the tumour nest was low in 137 (75.7%) and high in 44 (24.3%) patients. PD-1 staining in the tumour periphery was low in 78 (43.1%) and high in 103 (56.9%) patients. The 5 year progression-free survival rates in patients with the high PD-1 expression in the tumour nest and in the tumour periphery were 54.6% and 67.7%, respectively, which were significantly lower than those in their counterparts (79.4%, P < 0.001; 80.0%, P = 0.04). The 5 year cancer-specific survival rates in patients with the high PD-1 expression in the tumour nest and the tumour periphery were 69.1% and 75.7%, respectively, which were significantly lower than those in their counterparts (84.7%, P = 0.007; 87.8%, P = 0.01). A multivariate Cox regression analysis identified the high PD-1 expression in the tumour nest (hazard ratio 3.07, P < 0.001; hazard ratio 2.44, P = 0.011) and positive lymphovascular invasion (hazard ratio 4.86, P < 0.001; hazard ratio 4.03, P < 0.001) as independent predictors of disease progression and of cancer death, respectively. CONCLUSIONS: PD-1 positivity in the tumour nest could be a strong predictor for a worse clinical outcome and may be a useful indicator for selecting appropriate candidates for adjuvant therapy such as chemotherapy in upper tract urothelial carcinoma patients treated with radical nephroureterectomy.


Asunto(s)
Inmunohistoquímica/métodos , Nefroureterectomía/métodos , Receptor de Muerte Celular Programada 1/metabolismo , Neoplasias Ureterales/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tasa de Supervivencia , Neoplasias Ureterales/genética , Neoplasias Ureterales/mortalidad , Neoplasias Ureterales/patología
12.
Leukemia ; 32(3): 694-702, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28832024

RESUMEN

Somatic G17V RHOA mutations were found in 50-70% of angioimmunoblastic T-cell lymphoma (AITL). The mutant RHOA lacks GTP binding capacity, suggesting defects in the classical RHOA signaling. Here, we discovered the novel function of the G17V RHOA: VAV1 was identified as a G17V RHOA-specific binding partner via high-throughput screening. We found that binding of G17V RHOA to VAV1 augmented its adaptor function through phosphorylation of 174Tyr, resulting in acceleration of T-cell receptor (TCR) signaling. Enrichment of cytokine and chemokine-related pathways was also evident by the expression of G17V RHOA. We further identified VAV1 mutations and a new translocation, VAV1-STAP2, in seven of the 85 RHOA mutation-negative samples (8.2%), whereas none of the 41 RHOA mutation-positive samples exhibited VAV1 mutations. Augmentation of 174Tyr phosphorylation was also demonstrated in VAV1-STAP2. Dasatinib, a multikinase inhibitor, efficiently blocked the accelerated VAV1 phosphorylation and the associating TCR signaling by both G17V RHOA and VAV1-STAP2 expression. Phospho-VAV1 staining was demonstrated in the clinical specimens harboring G17V RHOA and VAV1 mutations at a higher frequency than those without. Our findings indicate that the G17V RHOA-VAV1 axis may provide a new therapeutic target in AITL.


Asunto(s)
Linfadenopatía Inmunoblástica/metabolismo , Linfoma de Células T/metabolismo , Proteínas Proto-Oncogénicas c-vav/metabolismo , Transducción de Señal , Proteína de Unión al GTP rhoA/metabolismo , Biomarcadores de Tumor , Línea Celular Tumoral , Citocinas/metabolismo , Análisis Mutacional de ADN , Humanos , Linfadenopatía Inmunoblástica/genética , Linfoma de Células T/genética , Mutación , Factores de Transcripción NFATC/metabolismo , Fosforilación , Unión Proteica , Proteínas Proto-Oncogénicas c-vav/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Proteína de Unión al GTP rhoA/genética
13.
J Int Med Res ; 33(6): 668-76, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16372585

RESUMEN

The efficacy of sparfloxacin (SPFX) for the control of bronchial asthma was evaluated in 26 patients with suspected Chlamydia pneumoniae infection. Patients were randomly allocated to receive SPFX 200 mg/day (n = 14) or control treatment (n = 12) for 21 days. Significant improvements in serum C-reactive protein levels, and significant decreases in peripheral eosinophil counts, serum eosinophil cationic protein (ECP) and sputum ECP were observed in the SPFX-treated group at day 21. SPFX-treated patients also had a significantly reduced frequency of asthma symptoms, reduced inhalant beta2-stimulant use, and significant increases in morning peak expiratory flow. At the end of the study, C. pneumoniae was undetectable in two SPFX-treated patients who underwent polymerase chain reaction testing, but one control patient who was tested still had detectable levels of C. pneumoniae. These results suggest that SPFX could be used to control bronchial asthma in patients with suspected persistent C. pneumoniae infection.


Asunto(s)
Asma/tratamiento farmacológico , Infecciones por Chlamydophila/tratamiento farmacológico , Chlamydophila pneumoniae/patogenicidad , Fluoroquinolonas/uso terapéutico , Administración por Inhalación , Anciano , Antiasmáticos/administración & dosificación , Antiasmáticos/uso terapéutico , Anticuerpos Antibacterianos/sangre , Asma/complicaciones , Proteína C-Reactiva/efectos de los fármacos , Proteína C-Reactiva/metabolismo , Infecciones por Chlamydophila/etiología , Infecciones por Chlamydophila/microbiología , Chlamydophila pneumoniae/inmunología , Chlamydophila pneumoniae/aislamiento & purificación , Proteína Catiónica del Eosinófilo/sangre , Proteína Catiónica del Eosinófilo/efectos de los fármacos , Femenino , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Ápice del Flujo Espiratorio
14.
Cardiovasc Res ; 24(3): 169-75, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2161286

RESUMEN

STUDY OBJECTIVE: The aim of the study was to assess the effects of hypothermia on sarcoplasmic reticulum in myocardium subjected to prolonged ischaemia. DESIGN: Calcium regulatory activity of myocardial sarcoplasmic reticulum was measured in hearts subjected to various periods of hypothermic ischaemia in comparison with hearts subjected to normothermic ischaemia. SUBJECTS: Hearts (n = 5-9 per experiment) were obtained from male New Zealand white rabbits, 2.0-2.8 kg weight. MEASUREMENTS AND RESULTS: Calcium uptake and calcium dependent ATPase activity were measured in isolated sarcoplasmic reticulum vesicles after hypothermic ischaemia was produced by immersing hearts in saline at 4 degrees C for 3, 6, or 12 h. Normothermic hearts were immersed for 3 h at 37 degrees C. Calcium uptake and calcium dependent ATPase (Ca-ATPase) activity were markedly inhibited by normothermic ischaemia. In hypothermic ischaemia, calcium uptake was only slightly depressed after 3 h, though longer periods of ischaemia resulted in significant depression of uptake. Ca-ATPase activity was unaffected after 6 h of hypothermic ischaemia. The ratio of calcium uptake to Ca-ATPase activity decreased after 3 h of hypothermic ischaemia. The phosphoenzyme concentration in sarcoplasmic reticulum was unaffected up to 6 h. The ratio of Ca-ATPase activity to phosphoenzyme concentration was not significantly altered until 12 h. Protein composition, examined by SDS-polyacrylamide gel electrophoresis, showed a decrease in 100,000 dalton polypeptide in normothermic ischaemia and after 12 h of hypothermic ischaemia. CONCLUSIONS: These results suggest that the depression of calcium uptake activity after 6 h of hypothermic ischaemia is likely to be due to uncoupling of calcium transport from ATP hydrolysis. Depressed Ca-ATPase activity at 12 h can be attributed to a reduction in the number of active calcium pump units. Hypothermia preserves function of myocardial sarcoplasmic reticulum during ischaemia for up to 3 h.


Asunto(s)
Calcio/metabolismo , Circulación Coronaria/fisiología , Hipotermia Inducida , Miocardio/metabolismo , Animales , ATPasas Transportadoras de Calcio/metabolismo , Electroforesis en Gel de Poliacrilamida , Técnicas In Vitro , Isquemia/metabolismo , Masculino , Fosfotransferasas/metabolismo , Conejos , Retículo Sarcoplasmático/metabolismo , Factores de Tiempo
15.
Blood Cancer J ; 5: e329, 2015 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-26230953

RESUMEN

Clinical significance of medullary abnormalities in the appendicular skeleton (AS) detected by low-dose whole-body multidetector computed tomography (MDCT) in patients with multiple myeloma (MM) was investigated. A total of 172 patients with monoclonal gammopathy of undetermined significance (MGUS) (n=17), smoldering MM (n=47) and symptomatic MM (n=108) underwent low-dose MDCT. CT values (CTv) of medullary density of AS⩾0 Hounsfield unit (HU) was considered as abnormal. Percentage of medullary abnormalities and the mean CTv of AS in patients with MGUS, smoldering MM and symptomatic MM were 18, 55 and 62% and -44.5 , -20.3 and 11.2 HU, respectively (P<0.001 and P<0.001). Disease progression of MM was independently associated with high CTv on multivariate analysis. In symptomatic MM, the presence of abnormal medullary lesions was associated with increased incidence of high-risk cytogenetic abnormalities (34.4% vs 7.7%; P=0.002) and extramedullary disease (10.4% vs 0%; P=0.032). It was also an independent poor prognostic predictor (hazard ratio 3.546, P=0.04). This study showed that CTv of AS by MDCT is correlated with disease progression of MM, and the presence of abnormal medullary lesions is a predictor for poor survival.


Asunto(s)
Neoplasias de la Médula Ósea/diagnóstico por imagen , Médula Ósea/diagnóstico por imagen , Mieloma Múltiple/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Médula Ósea/patología , Neoplasias de la Médula Ósea/mortalidad , Neoplasias de la Médula Ósea/secundario , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Tomografía Computarizada Multidetector , Mieloma Múltiple/mortalidad , Mieloma Múltiple/patología , Análisis Multivariante , Pronóstico , Modelos de Riesgos Proporcionales
16.
Biomaterials ; 13(3): 145-9, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1567938

RESUMEN

A methacrylate with a phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine (MPC), was grafted on cellulose membrane for haemodialysis in an aqueous medium using cerium ion (Ce4+) as an initiator. The effects of the concentrations of MPC and Ce4+, and degassing of feed solution on the grafting of MPC on the surface and the membrane properties such as permeability and mechanical strength were examined. The grafted MPC composition depended on the concentrations of both the monomer and initiator in the feed solution. When the grafted MPC distribution was controlled by the monomer concentration, the permeability of the membrane decreased with an increase in grafted MPC distribution. On the other hand, the permeability was not changed from the original membrane's value when the MPC distribution was regulated by Ce4+ concentration. The tensile strength of the membrane did not change during the grafting of MPC and this indicated that the grafting had taken place in the amorphous region of the cellulose. These results suggested that this method is a promising way to improve the blood compatibility of a cellulose membrane without having an adverse effect on the haemodialysis membrane.


Asunto(s)
Materiales Biocompatibles , Sangre , Riñones Artificiales , Membranas Artificiales , Materiales Biocompatibles/síntesis química , Fenómenos Biomecánicos , Secuencia de Carbohidratos , Celulosa/química , Humanos , Ensayo de Materiales , Metacrilatos , Datos de Secuencia Molecular , Permeabilidad , Fosforilcolina/análogos & derivados
17.
Biomaterials ; 20(17): 1545-51, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10482408

RESUMEN

To improve the surface blood compatibility of polysulfone (PSf) membranes, we prepared novel polymeric additives which have suitable blood compatibility. They were polymers with a phosphorylcholine group, a 2-methacryloyloxyethyl phosphorylcholine (MPC) unit. The MPC polymer could be blended with polysulfone by a solvent evaporation method during membrane processing, and a transparent membrane could be obtained. The mechanical properties of the blend membrane were similar to that of the original PSf membrane. Surface analysis of the blend membrane by X-ray photoelectron spectroscopy and dynamic contact angle measurement revealed that the MPC unit in the polymeric additive was concentrated on the surface of the membrane. The blend membrane significantly reduced plasma protein adsorption compared with that of the PSf membrane.


Asunto(s)
Materiales Biocompatibles/síntesis química , Sangre/efectos de los fármacos , Fosfolípidos/química , Ácidos Polimetacrílicos/síntesis química , Ácidos Polimetacrílicos/farmacología , Sulfonas/química , Adsorción , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Membranas Artificiales , Ácidos Polimetacrílicos/química , Propiedades de Superficie
18.
Biomaterials ; 20(17): 1553-9, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10482409

RESUMEN

Protein adsorption and platelet adhesion from human plasma on polysulfone (PSf) membranes modified with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer were studied. The modification was carried out by blending of the MPC polymer in the PSf. The amount of protein adsorbed on the PSf/MPC polymer blend membrane was significantly decreased with an increase in the composition of the blended MPC polymer. The distribution of the specific proteins adsorbed on the membrane surface was also determined by a gold-colloid immunoassay. Albumin, gamma-globulin and fibrinogen were observed on every membrane surface after contact with plasma. However, in the case of the blended membrane, the density of the adsorbed proteins decreased compared with that of original PSf membrane. That is, the MPC polymer blended in the membrane could function as a protein-adsorption-resistant additive. The number of platelets adhered on the PSf membrane was reduced, and change in the morphology of adherent platelets was also suppressed by the modification with the MPC polymer. Therefore, the PSf/MPC polymer blend membrane had improved blood compatibility compared with the PSf membrane.


Asunto(s)
Proteínas Sanguíneas/farmacocinética , Membranas Artificiales , Fosfolípidos/farmacología , Adhesividad Plaquetaria/efectos de los fármacos , Sulfonas/farmacología , Adsorción , Humanos , Ácidos Polimetacrílicos , Propiedades de Superficie
19.
Biomaterials ; 13(4): 235-9, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1520829

RESUMEN

The blood compatibility of a cellulose haemodialysis membrane whose surface was grafted with a methacrylate having a phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine, was evaluated with attention to platelet adhesion to the membrane surface and complement activation induced by the membrane. When the original cellulose membrane came in contact with platelet-rich plasma for 30 min, numerous platelets adhered to the surface and aggregated. On the other hand, the membrane grafted with 2-methacryloyloxyethyl phosphorylcholine effectively suppressed platelet adhesion and activation. This effect became more pronounced with increasing surface distribution. Especially, the 2-methacryloyloxyethyl phosphorylcholine grafted membranes, whose distribution exceeded 0.27, completely inhibited platelet adhesion, even when the contact time was 180 min. Moreover, the complement activation was also reduced with increased 2-methacryloyloxyethyl phosphorylcholine distribution on the surface of the membrane.


Asunto(s)
Celulosa/farmacología , Membranas Artificiales , Metacrilatos/farmacología , Fosforilcolina/análogos & derivados , Diálisis Renal/instrumentación , Animales , Materiales Biocompatibles , Proteínas Sanguíneas/efectos de los fármacos , Proteínas Sanguíneas/metabolismo , Celulosa/química , Activación de Complemento/efectos de los fármacos , Metacrilatos/química , Fosforilcolina/química , Fosforilcolina/farmacología , Adhesividad Plaquetaria/efectos de los fármacos , Conejos
20.
Clin Biochem ; 22(4): 309-12, 1989 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2789111

RESUMEN

A total of 1020 hospital employees were divided into an exposure group (n = 725) and a non-exposure group (n = 295), based on whether they had been exposed to blood from patients. The HBsAg-positive rates for the exposure and the non-exposure groups were 2.48% and 1.02%, respectively. In the exposure group, the minimal exposure rate increased with age from the twenties. The odds ratios were 7.39 in the technicians, 4.38 in physicians and 1.32 in nurses. Using age-sex matched pairs from the exposure and non-exposure groups, comparison of aspartate aminotransferase, alanine amino-transferase and guanase activities showed that there were significantly higher values in HBsAg-positive subjects (n = 18) from the exposure group than in HBsAg- and HBsAb-negative subjects from the non-exposure group (p less than 0.05-0.01). However, no significant differences were found in the enzyme activities in the matched pairs (n = 89) of HBsAb-positive subjects from the exposure and non-exposure groups.


Asunto(s)
Hepatitis B/epidemiología , Adulto , Factores de Edad , Alanina Transaminasa/sangre , Aspartato Aminotransferasas/sangre , Estudios Transversales , Exposición a Riesgos Ambientales , Femenino , Guanina Desaminasa/sangre , Hepatitis B/inmunología , Anticuerpos contra la Hepatitis B/análisis , Antígenos de la Hepatitis B/análisis , Humanos , Japón , Pruebas de Función Hepática , Masculino , Persona de Mediana Edad , Servicios de Salud del Trabajador , Radioinmunoensayo , Factores de Tiempo
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