Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 106
Filtrar
1.
J Viral Hepat ; 22(3): 254-62, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25081140

RESUMO

Triple therapy with telaprevir, pegylated interferon and ribavirin has been reported to improve antiviral efficacy but have potentially severe adverse effects in patients with chronic hepatitis C. To avoid the severe effects of telaprevir, lowering the dose has been suggested. However, impact of dosage changes on antiviral and adverse effects remains unclear. One hundred and sixty-six Japanese patients with HCV genotype 1 were treated with triple therapy. The drug exposure of each medication was calculated by averaging the dose actually taken. The overall SVR rate was 82%. The telaprevir discontinuation rate was 26%. The factors associated with discontinuation were an older age (≥65 y.o.) and a higher average dose during treatment. The telaprevir discontinuation rates were 42%, 25% and 14% in patients at ≥35, 25-35 and <25 mg/kg/day of telaprevir and 58% in older patients at ≥35 mg/kg/day of TVR. The factors associated with SVR were treatment-naïve, relapse to previous treatment, higher average telaprevir dose during treatment and completion of treatment. The SVR rate was higher, at 91%, in patients at 25-35 mg/kg/day of telaprevir than the 71% and 78% observed in those at <25 and ≥35 mg/kg/day of drug. In Japanese patients, a mean telaprevir dose of 25-35 mg/kg/day during treatment can augment its efficacy in triple therapy for patients with HCV genotype 1.


Assuntos
Genótipo , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Interferon-alfa/uso terapêutico , Oligopeptídeos/administração & dosagem , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Idoso , Antivirais/efeitos adversos , Antivirais/uso terapêutico , Biópsia , Feminino , Hepatite C Crônica/patologia , Humanos , Interferon alfa-2 , Interferon-alfa/efeitos adversos , Fígado/patologia , Fígado/virologia , Masculino , Pessoa de Meia-Idade , Oligopeptídeos/efeitos adversos , Polietilenoglicóis/efeitos adversos , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Estudos Retrospectivos , Ribavirina/efeitos adversos , Fatores de Risco , Resultado do Tratamento , Carga Viral
2.
J Viral Hepat ; 21(5): 357-65, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24716638

RESUMO

Pegylated interferon (Peg-IFN) plus ribavirin combination therapy is effective in patients with hepatitis C virus (HCV) infection and normal alanine aminotransferase levels (NALT). However, it remains unclear whether the risk of hepatocellular carcinoma (HCC) incidence is actually reduced in virological responders. In this study, HCC incidence was examined for 809 patients with NALT (ALT ≤ 40 IU/mL) treated with Peg-IFN alpha-2b and ribavirin for a mean observation period of 36.2 ± 16.5 months. The risk factors for HCC incidence were analysed by Kaplan-Meier method and Cox proportional hazards model. On multivariate analysis among NALT patients, the risk of HCC incidence was significantly reduced in patients with sustained virological response (SVR) or relapse compared with those showing nonresponse (NR) (SVR vs NR, hazard ratio (HR): 0.16, P = 0.009, relapse vs NR, HR: 0.11, P = 0.037). Other risk factors were older age (≥65 years vs <60 years, HR: 6.0, P = 0.032, 60-64 vs <60 years, HR: 3.2, P = 0.212) and male gender (HR: 3.9, P = 0.031). Among 176 patients with PNALT (ALT ≤ 30 IU/mL), only one patient developed HCC and no significant risk factors associated with HCC development were found. In conclusion, antiviral therapy for NALT patients with HCV infection can lower the HCC incidence in responders, particularly for aged and male patients. The indication of antiviral therapy for PNALT (ALT ≤ 30 IU/mL) patients should be carefully determined.


Assuntos
Alanina Transaminase/sangue , Antivirais/uso terapêutico , Carcinoma Hepatocelular/epidemiologia , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Adulto , Idoso , Feminino , Hepatite C Crônica/patologia , Humanos , Incidência , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/uso terapêutico , Estudos Retrospectivos , Fatores de Risco
3.
J Viral Hepat ; 16(8): 586-94, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19552664

RESUMO

The impact of ribavirin exposure on virologic relapse remains controversial in combination therapy with pegylated interferon (Peg-IFN) and ribavirin for patients with chronic hepatitis C (CH-C) genotype 1. The present study was conducted to investigate this. Nine hundred and eighty-four patients with CH-C genotype 1 were enrolled. The drug exposure of each medication was calculated by averaging the dose actually taken. For the 472 patients who were HCV RNA negative at week 24 and week 48, multivariate logistic regression analysis showed that the degree of fibrosis (P = 0.002), the timing of HCV RNA negativiation (P < 0.001) and the mean doses of ribavirin (P < 0.001) were significantly associated with relapse, but those of Peg-IFN were not. Stepwise reduction of the ribavirin dose was associated with a stepwise increase in relapse rate from 11% to 60%. For patients with complete early virologic response (c-EVR) defined as HCV RNA negativity at week 12, only 4% relapse was found in patients given > or = 12 mg/kg/day of ribavirin and ribavirin exposure affected the relapse even after treatment week 12, while Peg-IFN could be reduced to 0.6 microg/kg/week after week 12 without the increase of relapse rate. Ribavirin showed dose-dependent correlation with the relapse. Maintaining as high a ribavirin dose as possible (> or = 12 mg/kg/day) during the full treatment period can lead to suppression of the relapse in HCV genotype 1 patients responding to Peg-IFN alpha-2b plus ribavirin, especially in c-EVR patients.


Assuntos
Antivirais/uso terapêutico , Hepacivirus/isolamento & purificação , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Idoso , Relação Dose-Resposta a Droga , Feminino , Genótipo , Hepacivirus/genética , Humanos , Interferon alfa-2 , Interferon-alfa/administração & dosagem , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/administração & dosagem , RNA Viral/sangue , Proteínas Recombinantes , Recidiva , Ribavirina/administração & dosagem , Resultado do Tratamento
4.
J Viral Hepat ; 16(8): 578-85, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19552663

RESUMO

Chronic hepatitis C (CH-C) genotype 1 patients who achieved early virologic response have a high probability of sustained virologic response (SVR) following pegylated interferon (Peg-IFN) plus ribavirin therapy. This study was conducted to evaluate how reducing drug doses affects complete early virologic response (c-EVR) defined as hepatitis C virus (HCV) RNA negativity at week 12. Nine hundred eighty-four patients with CH-C genotype 1 were enrolled. Drug doses were evaluated independently on a body weight base from doses actually taken. From multivariate analysis, the mean dose of Peg-IFN alpha-2b during the first 12 weeks was the independent factor for c-EVR (P = 0.02), not ribavirin. The c-EVR rate was 55% in patients receiving > or = 1.2 microg/kg/week of Peg-IFN, and declined to 38% at 0.9-1.2 microg/kg/week, and 22% in patients given <0.9 microg/kg/week (P < 0.0001). Even with stratified analysis according to ribavirin dose, the dose-dependent effect of Peg-IFN on c-EVR was observed, and similar c-EVR rates were obtained if the dose categories of Peg-IFN were the same. Furthermore, the mean dose of Peg-IFN during the first 12 weeks affected HCV RNA negativity at week 24 (P < 0.0001) and SVR (P < 0.0001) in a dose-dependent manner. Our results suggest that Peg-IFN was dose-dependently correlated with c-EVR, independently of ribavirin dose. Thus, maintaining the Peg-IFN dose as high as possible during the first 12 weeks can yield HCV RNA negativity and higher c-EVR rates, leading to better SVR rates in patients with CH-C genotype 1.


Assuntos
Antivirais/uso terapêutico , Hepacivirus/isolamento & purificação , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Idoso , Relação Dose-Resposta a Droga , Feminino , Genótipo , Hepacivirus/genética , Humanos , Interferon alfa-2 , Interferon-alfa/administração & dosagem , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/administração & dosagem , RNA Viral/sangue , Proteínas Recombinantes , Resultado do Tratamento
5.
J Clin Invest ; 95(1): 404-11, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7814641

RESUMO

Heparin-binding EGF-like growth factor (HB-EGF) is a potent chemoattractant and mitogen for smooth muscle cells (SMC) in culture. To elucidate whether HB-EGF is implicated in the pathogenesis of human atherosclerosis, we examined immunohistochemical localization of HB-EGF in human aortic walls and atherosclerotic plaques. The medial SMC of the aorta in babies and children synthesized HB-EGF protein, while the number of SMC producing HB-EGF was dramatically decreased in young and middle-aged adults. In atherosclerotic plaques, however, marked production of HB-EGF protein was detected in SMC and macrophages of the plaques. Furthermore, EGF receptors, to which HB-EGF is known to bind, were detected in plaque SMC. These data suggest that HB-EGF may be implicated in the migration and proliferation of SMC that occurs in the normal development of arterial walls, and in the formation of atherosclerotic plaques.


Assuntos
Aorta/patologia , Arteriosclerose/patologia , Fator de Crescimento Epidérmico/isolamento & purificação , Macrófagos/química , Músculo Liso Vascular/química , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Arteriosclerose/etiologia , Criança , Receptores ErbB/isolamento & purificação , Feminino , Heparina/metabolismo , Fator de Crescimento Semelhante a EGF de Ligação à Heparina , Humanos , Imuno-Histoquímica , Lactente , Peptídeos e Proteínas de Sinalização Intercelular , Masculino , Pessoa de Meia-Idade
6.
J Clin Invest ; 108(5): 717-24, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11544277

RESUMO

Although L-arginine is the only substrate for nitric oxide (NO) production, no studies have yet been reported on the effect of an L-arginine deficiency on vascular function in humans. Lysinuric protein intolerance (LPI) is a rare autosomal recessive defect of dibasic amino acid transport caused by mutations in the SLC7A7 gene, resulting in an L-arginine deficiency. Vascular endothelial function was examined in an LPI patient who was shown to be a compound heterozygote for two mutations in the gene (5.3-kbp Alu-mediated deletion, IVS3+1G-->A). The lumen diameter of the brachial artery was measured in this patient and in healthy controls at rest, during reactive hyperemia (endothelium-dependent vasodilation [EDV]), and after sublingual nitroglycerin administration (endothelium-independent vasodilation [EIV]) using ultrasonography. Both EDV and NO(x) concentrations were markedly reduced in the patient compared with those for the controls. They became normal after an L-arginine infusion. EIV was not significantly different between the patient and controls. Positron emission tomography of the heart and a treadmill test revealed ischemic changes in the patient, which were improved by the L-arginine infusion. Thus, in the LPI patient, L-arginine deficiency caused vascular endothelial dysfunction via a decrease in NO production.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/fisiopatologia , Arginina/deficiência , Endotélio Vascular/fisiopatologia , Adulto , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/genética , Sistemas de Transporte de Aminoácidos Básicos , Arginina/sangue , Arginina/farmacologia , Proteínas de Transporte/genética , Angiografia Coronária , Teste de Esforço , Coração/diagnóstico por imagem , Hemodinâmica , Humanos , Masculino , Proteínas de Membrana/genética , Mutação , Óxido Nítrico/sangue , Tomografia Computadorizada de Emissão , Vasodilatação/efeitos dos fármacos
7.
Clin Nephrol ; 67(6): 358-65, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17598371

RESUMO

AIMS: Human serum paraoxonase (PON1) is associated with high-density lipoprotein, and inhibits oxidative modification of low-density lipoprotein. Therefore, PON1 is supposed to contribute to the prevention of atherosclerosis. We and other investigators have shown that the enzymatic activities and concentrations of PON1 were decreased in maintenance hemodialysis (HD) patients. However, the effect of PON1 status on the long-term outcome of HD patients has not been reported. In this study, we examined the association between baseline PON 1 status and cardiovascular mortality in an observation study of an outpatient HD population. PATIENTS AND METHODS: The relation between baseline cardiovascular risk factors and clinical events was investigated, during 6 years of follow-up, in 81 HD patients (50 males and 31 females) whose enzymatic activities, concentrations and genetic polymorphisms of PON1 had been determined in a previous study. RESULTS: During follow-up for 6 years, we recorded 42 deaths, including 24 fatal cardiovascular events. In univariate analyses, baseline PON1 concentration was associated with not only cardiovascular mortality (p < 0.005), but also all-cause mortality (p < 0.001) during the period of follow-up, as were age, preexisting cardiovascular disease (CVD) and hemoglobin concentration. In a multivariate Cox regression analysis, PON1 concentration retained significant associations with cardiovascular mortality (p < 0.05) and all-cause mortality (p < 0.005) even after correction of known risk factors for CVD or mortality in HD patients. Using Kaplan-Meier survival curves, we assessed the association between low and high concentrations of PON1 divided according to the median value (7.52 U/ml). Significantly increased cardiovascular mortality (log rank 6.125, p = 0.01) and all-cause mortality (log rank 7.113, p < 0.01) were detected in the patients with low PON1 concentrations. CONCLUSIONS: These data suggest that low PON 1 concentration may be an independent predictor of cardiovascular mortality in maintenance HD patients.


Assuntos
Arildialquilfosfatase/sangue , Doenças Cardiovasculares/mortalidade , Diálise Renal , Insuficiência Renal/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Análise de Sobrevida
8.
Nat Biotechnol ; 19(8): 746-50, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11479567

RESUMO

Specific cell ablation is a useful method for analyzing the in vivo function of cells. We have developed a simple and sensitive method for conditional cell ablation in transgenic mice, called "toxin receptor-mediated cell knockout." We expressed the diphtheria toxin (DT) receptor in transgenic mice using a hepatocyte-specific promoter and found that injection of DT caused fulminant hepatitis. Three independently established transgenic lines demonstrated a good correlation between the sensitivity of hepatocytes to DT and the expression level of the DT receptors. Moreover, the degree of hepatocyte damage was easily controlled over a wide range of doses of injected DT without any obvious abnormalities in other cells or tissues. This system is useful for generating mouse models of disease and for studying the recovery or regeneration of tissues from cell damage or loss. As DT is a potent inhibitor of protein synthesis in both growing and non-growing cells, the method is applicable to a wide range of cells and tissues in mice or in other DT-insensitive animals.


Assuntos
Camundongos Transgênicos , Receptores de Superfície Celular/metabolismo , Albuminas/genética , Animais , Northern Blotting , Relação Dose-Resposta a Droga , Elementos Facilitadores Genéticos , Fator de Crescimento Semelhante a EGF de Ligação à Heparina , Hepatócitos/metabolismo , Humanos , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intercelular , Fígado/citologia , Fígado/metabolismo , Camundongos , Camundongos Knockout , Modelos Biológicos , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , Regeneração , Fatores de Tempo , Distribuição Tecidual , Transaminases/sangue , Transfecção
9.
Oncogene ; 16(26): 3349-56, 1998 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-9692542

RESUMO

Transforming growth factors-beta (TGF-betas) play pivotal roles in the regulation of cell growth and differentiation, although little is known regarding the regulation of cytoplasmic components by TGF-betas. Src tyrosine kinase is required for signal transduction of various cytokine receptors, including epidermal growth factor (EGF), platelet-derived growth factor (PDGF), and G-protein coupled receptors. Moreover, Src tyrosine kinase is important in signal cross-talk between these receptors. To determine whether Src kinase is also involved in TGF-beta signaling, we examined the effects of TGF-beta1 on Src in the rat fibroblast cell line 3Y1 and in v-Src-transformed 3Y0 (SR-3Y1). TGF-beta1 inhibited mitogen-activated protein kinase activity and inhibited growth in SR-3Y1 cells, while it did not affect the growth of 3Y1 cells. TGF-beta1 significantly decreased v-Src kinase activity and protein abundance in SR-3Y1 cells, mainly by accelerating the degradation of v-Src. In contrast, in 3Y1 cells, TGF-beta1 did not affect c-Src abundance or kinase activity. However, upon activation of c-Src in 3Y1 cells by PDGF, TGF-beta1 decreased Src abundance. Additionally, in 3Y1 cells transfected with an activated c-Src mutant which lacks the SH3 domain, its level was decreased by TGF-beta1 treatment. These findings suggest that TGF-beta1 specifically induces degradation of activated Src kinase. This may be a novel mechanism for cross-talk between growth factors and TGF-beta1.


Assuntos
Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Relação Dose-Resposta a Droga , Ativação Enzimática , Fibroblastos/citologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Inibidores de Proteases/farmacologia , Ratos , Transdução de Sinais
10.
Biochim Biophys Acta ; 1220(2): 107-17, 1994 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-8312355

RESUMO

Among lysates from various organs and tissues of adult hamsters only lysates from liver demonstrated an inhibitory effect on the cell growth of SV40-transformed hamster fibroblasts in culture. Lysates from the liver of fetal hamsters and those from 7-day-old hamsters did not demonstrate any inhibitory effect on the cell growth. Lysates from the remnant liver 3 days after partial hepatectomy did not show any inhibitory effect on the cell growth but lysates from the remnant liver 14 days after the operation came to show an appreciable inhibitory effect on the cell growth. An inhibitor of the cell growth was purified from adult hamster liver by ammonium sulfate precipitation, DEAE-, hydroxyl apatite-, phenyl Sepharose- and Sephadex G75 column chromatography. The cell growth inhibitor thus prepared was shown to be pure by an ion-exchange chromatography, SDS-PAGE and analytical isoelectric focusing. The inhibitor was found to have a molecular mass of 37 kDa and an isoelectric point of approx. 7.5 and to cause reversible arrest of the transformed fibroblasts predominantly in the G0/G1 phase of the cell cycle at the concentration of approx. 0.9 microgram per ml.


Assuntos
Inibidores do Crescimento/isolamento & purificação , Fígado/química , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular/efeitos dos fármacos , Linhagem Celular Transformada/efeitos dos fármacos , Cromatografia/métodos , Cricetinae , Eletroforese em Gel de Poliacrilamida , Inibidores do Crescimento/química , Inibidores do Crescimento/farmacologia , Hepatectomia , Focalização Isoelétrica , Desnaturação Proteica , Fatores de Tempo , Tripsina
11.
Biochim Biophys Acta ; 1310(3): 309-16, 1996 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-8599609

RESUMO

The subcellular, intralobular distributions and intracellular partner(s) of a factor which inhibits the proliferation of cell growth (Hashimoto C. et al. (1994) Biochim. Biophys. Acta 1221, 107-117) were determined in hamster livers, using a combination of immunological and biochemical techniques. The IgG fraction from an antiserum raised against the growth inhibitory factor with 37 kDa was shown to be highly specific for the antigen. The nuclear and cytosolic fractions demonstrated inhibitory effects on cell growth and Western blot analysis revealed that both fractions contained the immunoreactive 37 kDa protein with the anti-inhibitory factor IgG but microsomal and mitochondrial fractions did not. The nuclear and cytoplasmic localization of the inhibitory factor were further confirmed by immunochemical staining mediated through the immune IgG and an avidin-biotinylated horseradish peroxidase complex, the parenchymal liver cells were clearly stained, but endothelial and connective tissue cells were not. Although some staining was evident throughout the liver parenchyma, the hepatocytes with most intensively stained nuclei were located in the periportal region. In the liver from hamsters 6 days old or the regenerating hamster livers 3 days after partial hepatectomy, the staining intensity was low and the number of hepatocytes with the inhibitory factor positive nuclei was very few compared with the adult hamster livers. In primary cultures of the isolated hepatocytes from adult hamster the inhibitory factor disappeared from nuclei after incubation for 24-48 h. The extracts of hepatic nuclei from adult hamsters were immunoprecipitated with either the anti-growth inhibitory factor IgG or a monoclonal antibody to the RM protein. The growth inhibitory factor and the RB protein coprecipitated in each case, implying that the proteins were complexed with each other in the nuclei. The RB protein family is composed of two sets of species, an un- or underphosphorylated species and a hyperphosphorylated one. It was suggested that the factor bound preferentially to the un- or underphosphorylated member of the family.


Assuntos
Inibidores do Crescimento/análise , Fígado/fisiologia , Animais , Especificidade de Anticorpos , Western Blotting , Núcleo Celular/fisiologia , Células Cultivadas , Cromatina/fisiologia , Cromatina/ultraestrutura , Cricetinae , Citosol/fisiologia , Eletroforese em Gel de Poliacrilamida , Inibidores do Crescimento/isolamento & purificação , Hepatectomia , Técnicas Imunoenzimáticas , Imunoglobulina G , Fígado/ultraestrutura , Peso Molecular , Fosforilação , Frações Subcelulares/fisiologia , Frações Subcelulares/ultraestrutura
12.
Biochim Biophys Acta ; 1355(3): 205-8, 1997 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-9060991

RESUMO

A cDNA clone encoding the mouse counterpart to adult hamster liver purified growth inhibitory factor (PGIF) was isolated from a mouse liver cDNA library by using antibodies raised against PGIF and sequenced. It contained a single open reading frame with a coding capacity for a 323 amino acid protein. Sequence analysis showed that it shared high homology with rat- and human liver arginases: the cDNA clone was 92% identical for rat arginase at the nucleotide level and was 93% identical to it at the deduced amino acid level. These results suggest that PGIF derived from adult hamster liver was identical or closely related to an isoform of hamster liver arginases.


Assuntos
Arginase/química , Inibidores do Crescimento/química , Fígado/química , Sequência de Aminoácidos , Animais , Arginase/genética , Arginase/farmacologia , Sequência de Bases , Divisão Celular/fisiologia , Clonagem Molecular , Cricetinae , DNA Complementar/química , Eletroforese em Gel de Poliacrilamida , Inibidores do Crescimento/genética , Inibidores do Crescimento/farmacologia , Humanos , Camundongos , Dados de Sequência Molecular , Ratos , Análise de Sequência , Homologia de Sequência de Aminoácidos
13.
J Gen Physiol ; 50(1): 203-24, 1966 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-5971029

RESUMO

Uptake of methionine, alpha-aminoisobutyric acid, and alpha-(methyl-amino)-isobutyric acid has been shown to occur by at least two transport systems, one sensitive and the other insensitive to the Na(+) concentration. For alpha-aminoisobutyric acid and its N-methyl derivative, the Na(+)-insensitive uptake is not concentrative and its rate increases almost linearly with concentration within the range examined. In contrast, the Na(+)-insensitive uptake of methionine is concentrative and subject to inhibition by such amino acids as phenylalanine, leucine, and valine, although not in a manner to indicate that the uptake is mediated by a single agency. This component is not produced by a residual operation of the Na(+)-requiring transport system, handicapped by the absence of Na(+) or by its having combined with alpha-aminoisobutyric acid. The increase in the rate of methionine uptake is linear with concentration only above about 16 mM methionine. The Na(+)-sensitive uptakes of methionine, alpha-aminoisobutyric, and alpha-(methylamino)-isobutyric acid appear to occur by the same population of transport-mediating sites. Both K(m) and V(max) of the Na(+)-sensitive uptake of these three amino acids change with changes in the concentration of Na(+), an effect which is shown to have a theoretical basis. A similarity in the values of Vmax for ten amino acids entering principally by the Na(+)-sensitive agency indicates that differences in their K(m) values probably measure differences in their affinities for that transport-mediating system.


Assuntos
Ácidos Aminoisobutíricos/metabolismo , Transporte Biológico , Carcinoma de Ehrlich/metabolismo , Metionina/metabolismo , Sódio/metabolismo , Animais , Concentração de Íons de Hidrogênio , Leucina/metabolismo , Camundongos , Fenilalanina/farmacologia , Valina/metabolismo
14.
Immunol Lett ; 69(3): 321-7, 1999 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-10528796

RESUMO

Some of the immunological effects of a variety of new quinolones on adhesion, phagocytosis, and production of reactive oxygen intermediators in neutrophils were studied. Ofloxacin, lomefloxacin, fleroxacin, and levofloxacin potentiated the phagocytosis of Escherichia coli in neutrophils. Moreover, lomefloxacin, and sparfloxacin significantly potentiated adhesion of neutrophils. In contrast, tosufloxacin was effective in significantly and persistently potentiating the production of superoxide anion, whereas the other agents markedly inhibited such production. Furthermore, tosufloxacin was effective in significantly potentiating the production of hydrogen peroxide, whereas sparfloxacin markedly inhibited such production. These results suggest that the new quinolones at a therapeutic concentration may affect functions such as phagocytosis, and production of superoxide anion in neutrophils.


Assuntos
Anti-Infecciosos/farmacologia , Neutrófilos/efeitos dos fármacos , 4-Quinolonas , Animais , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Peróxido de Hidrogênio/metabolismo , Neutrófilos/citologia , Neutrófilos/imunologia , Neutrófilos/fisiologia , Peritônio/citologia , Fagocitose/efeitos dos fármacos , Ratos , Superóxidos/metabolismo
15.
J Atheroscler Thromb ; 1(2): 108-12, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-9222878

RESUMO

To evaluate platelet activity in patients with non-insulin-dependent diabetes mellitus (NIDDM), we measured the mean platelet volume (MPV) and 24-hour urinary excretion of 11-dehydro-thromboxane B2 (11-dTXB2) and 6-keto-prostaglandin F1 alpha (6-kPGF1 alpha), stable metabolites of thromboxane A2 and prostacyclin, respectively. The MPV of the 103 subjects in the NIDDM group were 10.72 +/- 0.82 fl for males and 10.52 +/- 1.01 fl for females (mean +/- SD), significantly higher than those of normal controls (9.95 +/- 0.75 fl for males and 9.84 +/- 0.72 fl for females). The MPV of patients with NIDDM showed positive correlations with fasting plasma glucose level and HbA1c (r = 0.234, P < 0.05; r = 0.267, P < 0.01, respectively). The urinary excretion of 11-dTXB2 was greater in the NIDDM group (7.58 +/- 4.42 micrograms/day for males and 5.65 +/- 2.38 micrograms/day for females) than in the normal controls (4.61 +/- 2.31 and 3.83 +/- 1.60, respectively), suggesting that the synthesis of thromboxane A2 by platelets may be accelerated in vivo in patients with NIDDM. The urinary 6-kPGF1 alpha was not different between the NIDDM group and normal controls among the males, but was greater in the NIDDM group among the females. As MPV showed a positive correlation (r = 0.364, P < 0.05) with urinary excretion of 11-dTXB2, MPV may be related to platelet activity. These findings suggest that the platelets of patients with NIDDM may be in a hyperactive state.


Assuntos
6-Cetoprostaglandina F1 alfa/urina , Plaquetas/citologia , Diabetes Mellitus Tipo 2/metabolismo , Tromboxano B2/análogos & derivados , Idoso , Estudos de Casos e Controles , Tamanho Celular , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Tromboxano B2/urina
16.
Prog Neuropsychopharmacol Biol Psychiatry ; 20(7): 1197-211, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8938820

RESUMO

1. Physical dependence and cross-physical dependence on barbital of the benzodiazepine receptor partial agonist S-(+)-DN-2327 and the benzodiazepine receptor full agonist diazepam were compared in male Fischer 344 rats. 2. In the physical dependence study, rats were treated with S-(+)-DN-2327 (30, 100, 300 and 1000 mg/kg/day) or diazepam (30, 100 and 300 mg/kg/day) for 4 weeks by the drug admixed with food method. After stopping the treatment, the body weight and food consumption in the diazepam 100 and 300 mg/kg groups tended to decrease or decreased to values lower than those in the control group, whereas these parameters in the S-(+)-DN-2327 30, 100 and 300 mg/kg groups were comparable to the control group values. 3. In the cross-dependence study, rats were treated with increasing doses of barbital by admixing the drug with food for 4 weeks, after which the diet admixed with barbital was replaced by basal diet alone or admixed with S-(+)-DN-2327 or diazepam (target doses: 100 and 300 mg/kg/day for each compound). During the substitution period, the decreases in body weight and food consumption in both S-(+)-DN-2327 and both diazepam groups were suppressed compared with those in the basal diet group. 4. These results suggest that S-(+)-DN-2327 possesses minimal physical dependence-producing liability, but shows cross-dependence on barbital, as do benzodiazepine receptor full agonists.


Assuntos
Ansiolíticos/farmacologia , Barbital , Agonistas de Receptores de GABA-A , Hipnóticos e Sedativos , Naftiridinas/farmacologia , Compostos de Espiro/farmacologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Animais , Ansiolíticos/administração & dosagem , Área Sob a Curva , Barbital/efeitos adversos , Comportamento Animal/efeitos dos fármacos , Ligação Competitiva/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Diazepam/efeitos adversos , Diazepam/farmacologia , Ingestão de Alimentos/efeitos dos fármacos , Hipnóticos e Sedativos/efeitos adversos , Isoindóis , Masculino , Naftiridinas/administração & dosagem , Ratos , Ratos Endogâmicos F344 , Compostos de Espiro/administração & dosagem , Síndrome de Abstinência a Substâncias/psicologia
17.
J Gastroenterol ; 31(1): 75-80, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8808432

RESUMO

We administered ursodeoxycholic acid (UDCA) orally, at a daily dose of 600 mg, for 4 months to 36 patients with chronic viral hepatitis C. Another 36 patients with chronic viral hepatitis C, treated with placebo for 4 months, served as controls. None of the patients were alcoholics and none suffering from autoimmune hepatitis. Of the 36 patients in the UDCA-treated group, 13 had high levels of serum gamma-glutamyltranspeptidase (GGT), i.e., exceeding 150 U/l (normal < 50 U/l). Histological examination of liver biopsy specimens obtained from 10 patients in this group before treatment suggested that damage of the interlobular bile ducts was prominent in patients with higher levels of serum GGT. After 1 month of UDCA treatment, significant decreases in the levels of serum GGT, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were observed (P < 0.05 for GGT and AST), and the decreases continued for the 4-month treatment period. The reduction of GGT levels was the most prominent change in the liver function indices; the percent change in the GGT level was -25.2 +/- 4.4 (mean percent change +/- SE) at 1 month and -38.0 +/- 5.0 at 4 months. A significant correlation was observed between the serum delta GGT level (GGT value before treatment minus value after 3 months of treatment) and the total score for morphological injury of the bile ducts (P < 0.05). These results suggested that UDCA has the potential to reverse hepatocellular damage in patients with chronic viral hepatitis C, in whom high GGT levels may be due, in part, to a damaged interlobular bile duct. UDCA may be useful for the treatment of chronic viral hepatitis C, especially in patients exhibiting a high level of GGT.


Assuntos
Colagogos e Coleréticos/uso terapêutico , Hepatite C/tratamento farmacológico , Fígado/patologia , Ácido Ursodesoxicólico/uso terapêutico , Administração Oral , Adulto , Idoso , Colagogos e Coleréticos/administração & dosagem , Doença Crônica , Feminino , Hepatite C/enzimologia , Hepatite C/fisiopatologia , Humanos , Modelos Lineares , Fígado/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Ácido Ursodesoxicólico/administração & dosagem , gama-Glutamiltransferase/sangue
18.
J Gastroenterol ; 29(1): 31-4, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8199693

RESUMO

Glucagon, a potent inducer of urea cycle enzymes, was administered subcutaneously, at a dose of 0.5 mg once a day, for 7 days to two citrullinemic patients. During this period, plasma NH3 levels in case 1 decreased significantly (P < 0.05 compared to levels before administration) and daily urinary excretion of urea N increased significantly (P < 0.05). For 1 week after the cessation of administration, the daily urinary excretion of urea N was significantly higher than the level before administration (P < 0.05), the plasma citrulline level during glucagon administration was lower than that before administration. In case 2, glucagon administration also decreased the plasma NH3 level (although the decrease was not statistically significant), and significantly increased daily urinary excretion of urea N (P < 0.05 compared to levels before administration). For 1 week after the cessation of glucagon administration the plasma citrulline level was significantly lower than that before administration (P < 0.05). These results indicate that glucagon significantly increases the urinary excretion of urea in the late onset form of argininosuccinate synthetase deficiency and that it may also decrease plasma NH3 levels in some patients with the deficiency.


Assuntos
Amônia/sangue , Argininossuccinato Sintase/deficiência , Glucagon/uso terapêutico , Ureia/urina , Adulto , Erros Inatos do Metabolismo dos Aminoácidos/tratamento farmacológico , Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Citrulina/sangue , Feminino , Humanos , Masculino
19.
J Gastroenterol ; 32(1): 56-62, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9058296

RESUMO

The efficacy of interferon-alpha therapy in the treatment of chronic hepatitis C is still limited. A combination therapy of interferon-alpha with ursodeoxycholic acid (UDCA) was tested for its efficacy in the treatment of chronic hepatitis C by a randomized controlled study. Eighty consecutive Japanese patients with chronic hepatitis C were randomly divided into two groups: one group was treated with interferon-alpha (group A, n = 40) and the other with a combination of interferon-alpha and UDCA (group B, n = 40). In both groups, human interferon-alpha (6 million units per day) was intramuscularly injected daily for 2 weeks and then three times a week for 22 weeks: this 24-week period was followed by 24 weeks of observation. In group B, UDCA was also administered, daily at a dose of 600 mg orally, from the beginning of the interferon therapy and administration was continued for 48 weeks. The rates for ALT normalization and clearance of hepatitis C virus (HCV) viremia at the end of the 24-week interferon therapy were similar for groups A and B (58% vs 60% and 55% vs 48%, respectively). At the end of the 24-week follow-up, the sustained normalization rates for ALT levels for the two groups were not different (35% vs 43%), while the rate of clearance was higher in group B (40%) than in group A (23%), but the difference was not significant (P = 0.14). The sustained complete response, i.e., HCV RNA negativity at the end of the follow-up, as well as the maintenance of ALT normalization during the follow-up period, was more frequent in group B (38%) than in group A (18%) although the difference was not significant (P = 0.08). The rate of HCV reactivation after interferon was discontinued was significantly lower in group B (16%) than in group A (59%) (P < 0.01). Although this combination therapy did not lead to a sufficiently sustained complete response, it could serve as adjuvant antiviral therapy when a suitable dosage and administration period are determined.


Assuntos
Hepatite C/terapia , Interferon-alfa/administração & dosagem , Ácido Ursodesoxicólico/administração & dosagem , Administração Oral , Alanina Transaminase/sangue , Quimioterapia Combinada , Feminino , Hepacivirus/genética , Hepatite C/virologia , Hepatite Crônica/terapia , Humanos , Injeções Intramusculares , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , RNA Mensageiro/sangue
20.
Clin Chim Acta ; 197(3): 201-8, 1991 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-2049862

RESUMO

Nonspecific lipid transfer protein (nsLTP) partially purified from human liver stimulated human microsomal cholesterol 7 alpha-hydroxylase activity. Addition of the nsLTP preparation to the reaction mixture enhanced the activity two-fold. Treatment of the nsLTP preparation with anti-rat nsLTP antiserum, which cross-reacts with human nsLTP, reduced the 7 alpha-hydroxylase-stimulating ability. These observations suggested that nsLTP plays a role in regulating the 7 alpha-hydroxylase activity in the human liver. 7 alpha-Hydroxylase activity in eight patients with cholesterol gallstones (4.7 +/- 1.6 pmol/min per mg microsomal protein) was significantly lower than that in five controls (7.9 +/- 3.4) (P less than 0.05). The amount of nsLTP in the cytosolic fraction (105,000 X g supernatant) of human liver was determined by dot-blotting immunoquantitation with the antiserum. The cytosolic level of nsLTP in the liver of the patients (716 +/- 239 cpm/3 micrograms protein) was higher than that in the controls (438 +/- 184) although the difference between the two groups was not statistically significant. This suggested that control of the cytosolic level may be affected in patients with cholesterol gallstones.


Assuntos
Proteínas de Transporte/metabolismo , Colelitíase/enzimologia , Colesterol 7-alfa-Hidroxilase/metabolismo , Fígado/enzimologia , Adulto , Ácidos e Sais Biliares/biossíntese , Western Blotting , Colecistectomia , Citosol/metabolismo , Feminino , Humanos , Immunoblotting , Masculino , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA