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1.
Hepatol Res ; 50(9): 1047-1061, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32515851

RESUMO

AIM: Presently, no standardized definition or acceptable diagnostic criteria have been established for acute presentation of autoimmune hepatitis (AP-AIH), making it difficult to differentiate that condition from drug-induced liver injury (DILI). This study aimed to characterize clinical and histological features for distinguishing between AP-AIH and DILI. METHODS: Clinical, biochemical, and histological characteristics of AP-AIH and DILI in clinically well-characterized cases were compared in a standardized manner to clarify differences. RESULTS: In clinical evaluations, immunoglobulin G level and rate of anti-nuclear antibody positivity were greater in AP-AIH than DILI cases. As for diagnosis of each condition, significant (P < 0.01) differences were found for 10 features: lobular necrosis/inflammation, cobblestone appearance of hepatocytes, plasma cell infiltration in liver parenchyma, centrilobular fibrosis, hepatic rosette formation in areas with cobblestone appearance, portal inflammation, interface hepatitis, prominent plasma cells in portal areas, bile duct injury, and hepatic rosette formation in periportal areas. The area under the curve and cut-off values for the combination of these 10 features were 0.95 and 9 (sensitivity 86%, specificity 90%), respectively. CONCLUSION: Combinations of histological features were found to be helpful for differentiating AP-AIH from DILI, but we were not able to statistically identify an individual feature as definitive.

2.
J Toxicol Pathol ; 32(4): 319-327, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31719761

RESUMO

Digital pathology, including image analysis and automatic diagnosis of pathological tissue, has been developed remarkably. HALO is an image analysis platform specialized for the study of pathological tissues, which enables tissue segmentation by using artificial intelligence. In this study, we used HALO to quantify various histopathological changes and findings that were difficult to analyze using conventional image processing software. Using the tissue classifier module, the morphological features of degeneration/necrosis of the hepatocytes and muscle fibers, bile duct in the liver, basophilic tubules and hyaline casts in the kidney, cortex in the thymus, and red pulp, white pulp, and marginal zone in the spleen were learned and separated, and areas of interest were quantified. Furthermore, using the cytonuclear module and vacuole module in combination with the tissue classifier module, the number of erythroblasts in the red pulp of the spleen and each area of acinar cells in the parotid gland were quantified. The results of quantitative analysis were correlated with the histopathological grades evaluated by pathologists. By using artificial intelligence and other functions of HALO, we recognized morphological features, analyzed histopathological changes, and quantified the histopathological grades of various findings. The analysis of histopathological changes using HALO is expected to support pathology evaluations.

3.
Bioorg Med Chem ; 27(15): 3440-3450, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31235264

RESUMO

We have developed a new class of PDE10A inhibitor, a pyrazolo[1,5-a]pyrimidine derivative MT-3014 (1). A previous compound introduced was deprioritized due to concerns for E/Z-isomerization and glutathione-adduct formation at the core stilbene structure. We discovered pyrazolo [1,5-a] pyrimidine as a new lead scaffold by structure-based drug design utilizing a co-crystal structure with PDE10A. The lead compound was optimized for in vitro activity, solubility, and selectivity against human ether-á-go-go related gene cardiac channel binding. We observed that MT-3014 shows excellent efficacy in rat conditioned avoidance response test and suitable pharmacokinetic properties in rats, especially high brain penetration.


Assuntos
Descoberta de Drogas , Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases/metabolismo , Pirimidinas/farmacologia , Estilbenos/farmacologia , Animais , Bovinos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/química , Pirimidinas/síntese química , Pirimidinas/química , Estilbenos/química , Relação Estrutura-Atividade
4.
Genes Environ ; 40: 6, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29556374

RESUMO

INTRODUCTION: We examined the correlation between the results of in vitro and in vivo chromosomal damage tests by using in-house data of 18 pharmaceutical candidates that showed positive results in the in vitro chromosomal aberration or micronucleus test using CHL/IU cells, and quantitatively analyzed them especially in regard to exposure levels of the compounds. FINDINGS: Eight compounds showed that the exposure levels [maximum plasma concentration (Cmax) and AUC0-24h] were comparable with or higher than the in vitro exposure levels [the lowest effective (positive) concentration (LEC) and AUCvitro = LEC (µg/mL) × treatment time (h)]. Among them, 3 compounds were positive in the in vivo rodent micronucleus assays using bone marrow cells. For 2 compounds, cytotoxicity might produce false-positive results in the in vitro tests. One compound showed in vitro positive results only in the condition with S9 mix which indicated sufficient concentration of unidentified active metabolite(s) might not reach the bone marrow to induce micronuclei. CONCLUSION: These facts suggested that the in vivo exposure levels being equal to or higher than the in vitro exposure levels might be an important factor to detect in vivo chromosomal damage induced by test chemicals.

5.
Biosci Biotechnol Biochem ; 82(4): 689-697, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29165050

RESUMO

The genus Bifidobacterium is well known to have beneficial health effects. We discovered that quercetin and related polyphenols enhanced the secretion of anti-inflammatory substances by Bifidobacterium adolescentis. This study investigated characteristics of the anti-inflammatory substances secreted by B. adolescentis. The culture supernatant of B. adolescentis with quercetin reduced the levels of inflammatory mediators in activated macrophages. Spontaneous quercetin degradant failed to increase anti-inflammatory activity, while the enhancement of anti-inflammatory activity by quercetin was sustained after washout of quercetin. Physicochemical treatment of the culture supernatant indicated that its bioactive substances may be heat-stable, non-phenolic, and acidic biomolecules with molecular weights less than 3 kDa. Acetate and lactate have little or no effect on nitric oxide production. Taken together, the anti-inflammatory substances secreted by B. adolescentis may be small molecules but not short chain fatty acids. In agreement with these findings, stearic acid was tentatively identified as a bioactive candidate compound.


Assuntos
Anti-Inflamatórios/farmacologia , Bifidobacterium adolescentis/efeitos dos fármacos , Alimento Funcional , Quercetina/farmacologia , Acetatos/metabolismo , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Bifidobacterium adolescentis/metabolismo , Western Blotting , Linhagem Celular , Cromatografia Líquida , Meios de Cultura , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Lactatos/metabolismo , Lipopolissacarídeos/farmacologia , Espectrometria de Massas , Camundongos , Peso Molecular , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Ácidos Esteáricos/farmacologia
6.
Hepatology ; 64(4): 1189-201, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27178326

RESUMO

UNLABELLED: In most autoimmune diseases the serologic hallmarks of disease precede clinical pathology by years. Therefore, the use of animal models in defining early disease events becomes critical. We took advantage of a "designer" mouse with dysregulation of interferon gamma (IFNγ) characterized by prolonged and chronic expression of IFNγ through deletion of the IFNγ 3'-untranslated region adenylate uridylate-rich element (ARE). The ARE-Del(-/-) mice develop primary biliary cholangitis (PBC) with a female predominance that mimics human PBC that is characterized by up-regulation of total bile acids, spontaneous production of anti-mitochondrial antibodies, and portal duct inflammation. Transfer of CD4 T cells from ARE-Del(-/-) to B6/Rag1(-/-) mice induced moderate portal inflammation and parenchymal inflammation, and RNA sequencing of liver gene expression revealed that up-regulated genes potentially define early stages of cholangitis. Interestingly, up-regulated genes specifically overlap with the gene expression signature of biliary epithelial cells in PBC, implying that IFNγ may play a pathogenic role in biliary epithelial cells in the initiation stage of PBC. Moreover, differentially expressed genes in female mice have stronger type 1 and type 2 IFN signaling and lymphocyte-mediated immune responses and thus may drive the female bias of the disease. CONCLUSION: Changes in IFNγ expression are critical for the pathogenesis of PBC. (Hepatology 2016;64:1189-1201).


Assuntos
Doenças Autoimunes/etiologia , Colangite/imunologia , Interferon gama/biossíntese , Animais , Doenças Autoimunes/metabolismo , Colangite/metabolismo , Feminino , Masculino , Camundongos , Fatores Sexuais
7.
J Clin Pathol ; 69(3): 226-33, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26290259

RESUMO

BACKGROUND: Oxidative stress may play pathogenic roles in the mechanisms underlying chronic hepatitis C (CHC). The impact of excessive oxidative stress and iron dysregulation on the development of hepatocellular carcinoma (HCC) after interferon therapy has not been established. METHODS: We investigated the impact of oxidative stress and iron deposition on HCC development after therapy with pegylated interferon (PegIFN)+ribavirin in CHC patients. Systemic and intracellular iron homeostasis was evaluated in liver tissues, peripheral blood mononuclear cells and sera. RESULTS: Of 203 patients enrolled, 13 developed HCC during the 5.6-year follow-up. High hepatic 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were significantly associated with HCC development in multivariate analysis (p=0.0012) which was also significantly correlated with severity of hepatic iron deposition before therapy (p<0.0001). Systemic and intracellular iron regulators of hepcidin and F-box and leucine-rich repeat protein 5 (FBXL5) expression levels were significantly suppressed in CHC patients (p=0.0032 and p=0.016, respectively) despite their significantly higher levels of serum iron and ferritin compared with controls. However, intracellular iron regulators of FBXL5 and iron regulatory proteins were regulated in balance with hepatic iron deposition. Significant correlations were observed among IL-6, bone morphogenetic protein 6, hepcidin and ferroportin, as regards systemic iron regulation. CONCLUSIONS: Measurement of hepatic oxidative stress before antiviral therapy is useful for the prediction of HCC development after interferon therapy. Low baseline levels of the intracellular iron regulators of FBXL5 in addition to a suppressed hepcidin level might be associated with severe hepatic iron deposition in CHC patients. TRIAL REGISTRATION NUMBER: UMIN 000001031.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/virologia , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Distúrbios do Metabolismo do Ferro/metabolismo , Neoplasias Hepáticas/virologia , Fígado/efeitos dos fármacos , Estresse Oxidativo , Polietilenoglicóis/uso terapêutico , 8-Hidroxi-2'-Desoxiguanosina , Idoso , Biomarcadores/metabolismo , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Progressão da Doença , Quimioterapia Combinada , Feminino , Seguimentos , Hepatite C Crônica/complicações , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/metabolismo , Humanos , Distúrbios do Metabolismo do Ferro/complicações , Distúrbios do Metabolismo do Ferro/diagnóstico , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/virologia , Fígado/metabolismo , Fígado/virologia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/metabolismo , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Modelos de Riscos Proporcionais , Proteínas Recombinantes/uso terapêutico , Ribavirina/uso terapêutico , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
8.
Biosci Biotechnol Biochem ; 79(5): 799-807, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25721815

RESUMO

Probiotics have been shown to improve the condition of not only the human gastrointestinal tract but also the entire body. We found that quercetin enhances the anti-inflammatory activity of Bifidobacterium adolescentis, which is abundant in human intestines. Here, we assessed whether certain phytochemicals could enhance the anti-inflammatory activity of B. adolescentis. Bifidobacteria were anaerobically cultured with phytochemicals for 3 h, and the anti-inflammatory activity of the supernatants was estimated by testing their ability to inhibit nitric oxide (NO) production by lipopolysaccharide-stimulated RAW264 macrophages. Of the 55 phytochemicals tested, phloretin, (+)-taxifolin, and (-)-epigallocatechin gallate as well as quercetin-3-O-glucoside and quercetin-4'-O-glucoside were similar to quercetin in promoting NO suppression by B. adolescentis. In addition, the phytochemicals excluding quercetin increased the concentrations of lactic and acetic acids in the co-culture supernatants. These results suggest that some phytochemicals may activate the anti-inflammatory function of B. adolescentis.


Assuntos
Anti-Inflamatórios/farmacologia , Bifidobacterium , Probióticos/farmacologia , Ácido Acético/metabolismo , Animais , Bifidobacterium/efeitos dos fármacos , Bifidobacterium/fisiologia , Catequina/análogos & derivados , Catequina/farmacologia , Linhagem Celular/efeitos dos fármacos , Técnicas de Cocultura , Relação Dose-Resposta a Droga , Flavonoides , Glucosídeos , Ácido Láctico/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , Óxido Nítrico/metabolismo , Compostos Fitoquímicos/farmacologia , Quercetina/análogos & derivados , Quercetina/farmacologia
9.
Mediators Inflamm ; 2015: 913793, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26783385

RESUMO

The liver biopsy remains a valuable tool in the diagnosis of drug-induced liver injury (DILI). The Digestive Disease Week Japan 2004 (DDW-J) scale proposed as an objective tool for the diagnosis of DILI has been widely used in Japan. So far, the histological features have not been compared with DDW-J scale in detail. Herein, we examined the correlation between liver biopsy findings and clinical features, particularly DDW-J scales. A total of 80 patients with liver injuries of unknown cause were enrolled. Based on the histological findings, these cases were categorized into 3 groups: A (DILI was strongly suspected), B (DILI was suspected), and C (DILI should be considered in the differential diagnosis). Histological groups and DDW-J scale were moderately correlated (κ = 0.60). The mean total DDW-J scale scores were as follows: 4.89 for A, 3.26 for B, and 0.75 for C (p < 0.05). While hepatocellular type was coincided in a majority of cases by histological and DDW-J scale evaluation, cholestatic type was not well coincided. In conclusion, biopsy findings and DDW-J scale were well correlated, and the hepatocellular type of liver injuries was well coincided by both evaluations, though there were several discrepant cases, particularly in cholestatic type.


Assuntos
Biópsia , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Fígado/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Hepática Induzida por Substâncias e Drogas/classificação , Doença Hepática Induzida por Substâncias e Drogas/patologia , Diagnóstico Diferencial , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Acta Med Okayama ; 68(1): 17-22, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24553484

RESUMO

The impact of hepatic steatosis on interferon therapy for patients with chronic hepatitis C (CHC) has been associated with single-nucleotide polymorphisms (SNP) of IL28B, patatin-like phospholipase domain-containing protein 3 (PNPLA3), and low-density lipoprotein (LDL) receptor. Whether this holds true for Japanese patients, however, remains unresolved. The present study prospectively enrolled 226 Japanese patients with CHC, and investigated the impact of hepatic steatosis and its related SNPs, including rs8099917 of IL28B, rs738409 of PNPLA3, and rs14158 of LDL receptor, on outcomes of peg-interferon and ribavirin therapy. In multivariate logistic regression analysis, significant factors affecting the severity of hepatic steatosis were high body mass index and the minor alleles of IL28B SNP (p=0.020 and 0.039, respectively). The risk alleles of PNPLA3 SNP also showed weak association (p=0.059). Severe steatosis and the minor alleles of IL28B SNP were significantly associated with null or partial virological response in patients with HCV genotype 1, as were female gender, and low LDL cholesterol (p=0.049, and <0.001, respectively). The SNP genotype of PNPLA3 and LDL receptor did not have a significant impact on therapeutic outcomes. With respect to the SNP sites examined, the SNP of PNPLA3 has a weak association with severe hepatic steatosis, but not with the outcome of interferon therapy.


Assuntos
Fígado Gorduroso/genética , Hepatite C Crônica/tratamento farmacológico , Interleucinas/genética , Lipase/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único , Receptores de LDL/genética , Idoso , Feminino , Hepatite C Crônica/genética , Humanos , Interferons/uso terapêutico , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
11.
Springerplus ; 2(1): 251, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23772356

RESUMO

The impact of single-nucleotide polymorphisms (SNP) of patatin-like phospholipase domain-containing protein 3 (PNPLA3) on development of hepatocellular carcinoma (HCC) is not clarified for Japanese patients with chronic hepatitis C. The present study investigated the associations of rs738409 PNPLA3 with HCC development after the antiviral therapy with peg-interferon and ribavirin for Japanese patients with hepatitis C virus serotype 1 and high viral load. Of the 271 patients enrolled in the study, 20 patients developed HCC, during a median follow-up period of 4.6 years. Multivariate analysis in the proportional hazards models revealed that sex, body mass index, platelet counts, and alpha feroprotein (AFP) had significant associations with HCC development (p = 0.011, 0.029, 0.0002, and 0.046, respectively). Multivariate regression analysis revealed that PNPLA3 148 M was significantly associated with serum AFP level (p = 0.032), other than body mass index, platelet count, and alanine aminotransferase (p = 0.0006, 0.0002, and 0.037, respectively), and that serum AFP level was significantly associated with PNPLA3 148 M (p = 0.017). Serum AFP level is an important factor in predicting HCC development after the antiviral therapy for Japanese patients with chronic hepatitis C, the mechanism of which might involve its significant associations with the SNP genotype of PNPLA3.

12.
J Med Virol ; 84(10): 1562-70, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22930504

RESUMO

To clarify the factors associated with delayed reduction of HBV DNA during combination treatment with adefovir dipivoxil (ADV) and lamivudine (LAM) for patients with LAM-resistant hepatitis B virus (HBV), factors including patient characteristics, viral mutations, and drug metabolism were investigated during a 5-year observation period. Delayed reduction of HBV DNA was defined as delayed viral response of detectable HBV DNA after 3 years of combination therapy. Of 67 consecutive patients, 47 attained undetectable HBV DNA after 3 years of combination therapy, and the mean therapeutic duration was 5 years (range: 3.0-8.4 years). The patients with delayed viral response had high levels of HBV DNA and HBe antigen, while those with negative or low levels of HBe antigen were also negative for HBV DNA, even if they had high levels of HBV DNA. In the multivariate analysis with the proportional hazards model, a high baseline level of HBe antigen was negatively associated with viral decline to an undetectable level (P = 0.013). A higher baseline of HBe antigen corresponded to a lower annual decline in HBV DNA (R = -0.38, P = 0.004). No patients showed ADV-resistant mutations in the HBV reverse transcriptase region. Trough concentrations of LAM and ADV showed no clear associations with viral response. HBe antigen levels at the initiation of therapy, and reductions in these levels during therapy are predictive of the therapeutic response to combination therapy with ADV and LAM for patients with LAM-resistant HBV.


Assuntos
Adenina/análogos & derivados , Antivirais/administração & dosagem , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/tratamento farmacológico , Lamivudina/administração & dosagem , Organofosfonatos/administração & dosagem , Carga Viral , Adenina/administração & dosagem , Adulto , Idoso , Estudos de Coortes , DNA Viral/sangue , Feminino , Hepatite B Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
13.
J Gastroenterol Hepatol ; 27(8): 1320-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22414162

RESUMO

BACKGROUND AND AIMS: Recent routine testing for anti-mitochondrial antibodies has increased the number of patients with early primary biliary cirrhosis (PBC). The prevalence and clinical significance of esophageal varices in those patients remains obscure. METHODS: A systematic cohort analysis of 256 PBC patients was performed to clarify the prevalence, characteristics, and prognosis of the patients with early PBC and esophageal varices. RESULTS: Twenty-two patients had esophageal varices at the time of diagnosis: 5.5% (12/217) with early disease of histological stage 1 or 2, and 25.6% (10/39) with advanced disease of stage 3 or 4. Immediate treatments were required for two patients with early PBC: one for bleeding varices, and the other for large varices. The overall survival of the patients with early PBC and esophageal varices at diagnosis did not significantly differ from that of patients without esophageal varices (P = 0.66). High alkaline phosphatase (ALP) ratios (odds ratio = 2.3) and low platelet counts (odds ratio = 0.77) were significantly associated with the presence of esophageal varices in the patients with early PBC. Significant associations of these two factors with the development of esophageal varices during follow-up were also revealed (odds ratio = 1.4 and 0.88, respectively). The patients with early PBC and high ALP ratios ≥ 1.9 had significantly high risks of developing esophageal varices during follow-up (P = 0.022). CONCLUSIONS: High ALP ratios and low platelet counts at diagnosis and decreased platelet counts during follow-up are useful predictors of esophageal varices in patients with early PBC.


Assuntos
Varizes Esofágicas e Gástricas/epidemiologia , Cirrose Hepática Biliar/epidemiologia , Adulto , Idoso , Fosfatase Alcalina/sangue , Biomarcadores/sangue , Diagnóstico Precoce , Varizes Esofágicas e Gástricas/diagnóstico , Varizes Esofágicas e Gástricas/mortalidade , Varizes Esofágicas e Gástricas/terapia , Feminino , Hemorragia Gastrointestinal/epidemiologia , Humanos , Japão/epidemiologia , Estimativa de Kaplan-Meier , Cirrose Hepática Biliar/diagnóstico , Cirrose Hepática Biliar/mortalidade , Cirrose Hepática Biliar/terapia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Contagem de Plaquetas , Valor Preditivo dos Testes , Prevalência , Prognóstico , Modelos de Riscos Proporcionais , Medição de Risco , Fatores de Risco , Fatores de Tempo , Regulação para Cima
14.
Nihon Shokakibyo Gakkai Zasshi ; 107(10): 1676-85, 2010 Oct.
Artigo em Japonês | MEDLINE | ID: mdl-20938119

RESUMO

A 63-year-old man with Stage IVa pancreas tail cancer was admitted for a distal pancreatectomy and splenectomy; adjuvant chemotherapy with gemcitabine was also administered. The chemotherapy was terminated after 16 courses due to hemolytic anemia, thrombocytopenia and renal dysfunction. Plasma exchange was performed; however the patient's renal function was diminished, requiring chronic hemodialysis. Physicians should be cautious of hemolytic uremic syndrome as a possible adverse reaction to gemcitabine and be aware that tests are needed for its early detection.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Desoxicitidina/análogos & derivados , Síndrome Hemolítico-Urêmica/induzido quimicamente , Neoplasias Pancreáticas/tratamento farmacológico , Quimioterapia Adjuvante/efeitos adversos , Desoxicitidina/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Gencitabina
15.
J Biochem ; 147(1): 83-93, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19762342

RESUMO

The methods of homologous high-level expression and simple large-scale purification for coenzyme B(12)-dependent ethanolamine ammonia-lyase of Escherichia coli were developed. The eutB and eutC genes in the eut operon encoded the large and small subunits of the enzyme, respectively. The enzyme existed as the heterododecamer alpha(6)beta(6). Upon active-site titration with adeninylpentylcobalamin, a strong competitive inhibitor for coenzyme B(12), the binding of 1 mol of the inhibitor per mol of the alphabeta unit caused complete inhibition of enzyme, in consistent with its subunit structure. EPR spectra indicated the formation of substrate-derived radicals during catalysis and the binding of cobalamin in the base-on mode, i.e. with 5,6-dimethylbenzimidazole coordinating to the cobalt atom. The purified wild-type enzyme underwent aggregation and inactivation at high concentrations. Limited proteolysis with trypsin indicated that the N-terminal region is not essential for catalysis. His-tagged truncated enzymes were similar to the wild-type enzyme in catalytic properties, but more resistant to p-chloromercuribenzoate than the wild-type enzyme. A truncated enzyme was highly soluble even in the absence of detergent and resistant to aggregation and oxidative inactivation at high concentrations, indicating that a short N-terminal sequence is sufficient to change the solubility and stability of the enzyme.


Assuntos
Escherichia coli/enzimologia , Etanolamina Amônia-Liase/isolamento & purificação , Etanolamina Amônia-Liase/metabolismo , Catálise , Estabilidade Enzimática , Etanolamina Amônia-Liase/química , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Solubilidade
16.
Biochem Biophys Res Commun ; 391(4): 1610-5, 2010 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-20026060

RESUMO

Deregulated activation of protein tyrosine kinases, such as the epidermal growth factor receptor (EGFR) and Abl, is associated with human cancers including non-small cell lung cancer (NSCLC) and chronic myeloid leukemia (CML). Although inhibitors of such activated kinases have proved to be of therapeutic benefit in individuals with NSCLC or CML, some patients manifest intrinsic or acquired resistance to these drugs. We now show that, whereas blockade of either the extracellular signal-regulated kinase (ERK) pathway or the phosphatidylinositol 3-kinase (PI3K)-Akt pathway alone induced only a low level of cell death, it markedly sensitized NSCLC or CML cells to the induction of apoptosis by histone deacetylase (HDAC) inhibitors. Such enhanced cell death induced by the respective drug combinations was apparent even in NSCLC or CML cells exhibiting resistance to EGFR or Abl tyrosine kinase inhibitors, respectively. Co-administration of a cytostatic signaling pathway inhibitor may contribute to the development of safer anticancer strategies by lowering the required dose of cytotoxic HDAC inhibitors for a variety of cancers.


Assuntos
Analgésicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Resistencia a Medicamentos Antineoplásicos , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Inibidores de Histona Desacetilases/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Neoplasias Pulmonares/enzimologia , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Benzamidas/farmacologia , Receptores ErbB/genética , Receptores ErbB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Gefitinibe , Humanos , Mesilato de Imatinib , Fosfatidilinositol 3-Quinases/metabolismo , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirimidinas/farmacologia , Quinazolinas/farmacologia
18.
Transl Res ; 148(3): 103-13, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16938647

RESUMO

UNLABELLED: Primary biliary cirrhosis (PBC) is a chronic, cholestatic liver disease characterized by progressive destruction of interlobular bile ducts that leads to biliary cirrhosis. To elucidate the etiology of PBC, the gene expression profile in biliary epithelial cells (BECs) was analyzed. Liver specimens of 5 PBC, 3 chronic hepatitis C (CHC), and 3 normal subjects were obtained. BECs were selectively collected by laser capture microdissection (LCM), RNA were obtained by extraction and amplification with T7 RNA polymerase, and a cDNA microarray analysis was performed. The following genes exhibited increased expression in BEC of PBC, as compared with CHC or normal subjects: human leukocyte antigen DQ alpha 1 (HLA-DQA-1), carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and vascular cell adhesion molecule 1 (VCAM-1). The immunohistochemistry for HLA-DQA-1, CEACAM1, TRAIL, and VCAM-1 confirmed these results. Furthermore, two-way cluster analysis showed that the gene expression profiling in BEC of PBC were categorized into a separate cluster, distinct from CHC or normal subjects. CONCLUSIONS: The gene expression profiling in BEC of PBC differed from those of CHC and normal subjects, and the genes concerning local immune response, such as HLA-DQA-1, CEACAM1, TRAIL, and VCAM-1, exhibited increased expression, indicating that they were involved in the development of bile duct injury.


Assuntos
Ductos Biliares Intra-Hepáticos/metabolismo , Cirrose Hepática Biliar/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Adulto , Idoso , Ductos Biliares Intra-Hepáticos/patologia , DNA/análise , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Técnica Direta de Fluorescência para Anticorpo , Perfilação da Expressão Gênica , Marcadores Genéticos , Hepatite Crônica/genética , Hepatite Crônica/metabolismo , Hepatite Crônica/patologia , Humanos , Lasers , Cirrose Hepática Biliar/metabolismo , Cirrose Hepática Biliar/patologia , Testes de Função Hepática , Masculino , Microdissecção/métodos , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo
19.
Cancer Lett ; 223(1): 67-76, 2005 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15890238

RESUMO

The p53R2 gene encodes the ribonucleotide reductase (RR) small subunit 2 homologue, and is induced by several stress signals activating p53, such as DNA-damaging agents. The p53R2 gene product causes an increase in the deoxynucleotide triphosphate (dNTP) pool in the nucleus, which facilitates DNA repair and synthesis. We hypothesized that p53R2 would be a good molecular target for cancer gene therapy. In this study, three human oral cancer cell lines (SAS, HSC-4 and Ca9-22), a human breast cancer cell line MCF-7, and a normal human fibroblast cell line NHDF were tested. We silenced the expression of p53R2 with the highly specific post-transcriptional suppression of RNA interference (RNAi). We investigated p53R2 expression with the reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. The sensitivity to anticancer agents was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The expression of p53R2 showed no association with the mutational status of p53. The cancer cell lines with higher p53R2 expression were more resistant to 5-FU. RNAi-mediated p53R2 reduction selectivity inhibited growth and enhanced chemosensitivity in cancer cell lines but not in normal fibroblasts. These results suggest that basal transcription of p53R2 could be associated with the sensitivity to anticancer agents. Moreover, we assessed the possibility that p53R2 would be a good molecular target, and report that RNAi targeting of p53R2 could be useful for oral cancer gene therapy.


Assuntos
Fluoruracila/farmacologia , Inativação Gênica , Genes p53 , Terapia Genética , Neoplasias Bucais/terapia , Interferência de RNA , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias Bucais/patologia , RNA Mensageiro/análise
20.
Mod Pathol ; 16(7): 679-85, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12861064

RESUMO

RCAS1, a novel tumor-associated antigen, is expressed in advanced human neoplasias including uterine and ovarian carcinomas. RCAS1 protein was indicated to induce cell cycle arrest and apoptosis of cultured human lymphoid and myeloid cell lines and normal lymphocytes. In the present study, we investigated the expression and prognostic value of RCAS1 in 58 patients with colorectal carcinomas. RCAS1 protein was detected by immunoperoxidase staining using a mouse monoclonal anti-RCAS1 antibody (22-1-1 antibody). Immunohistochemical examination showed expression of RCAS1 in 75% of colorectal carcinomas with lymph node metastases (n = 24), whereas it was present in only 41% of tumors without metastases (n = 34, P <.05). Patients with RCAS1-positive tumors showed a significantly poorer prognosis than those negative for RCAS1 (P <.05). Multivariate analysis using the Cox regression model indicated that RCAS1 positivity was an independent negative predictor for survival (P =.0300; risk ratio, 0.496). In addition, apoptotic cells of tumor-infiltrating lymphocytes were examined using nonradioactive in situ nick translation in paraffin-embedded sections. The proportion of apoptotic tumor-infiltrating lymphocytes was significantly higher in RCAS1-positive colorectal carcinomas (11.2 +/- 1.0) than in RCAS1-negative tumors (7.9 +/- 1.0, P <.05). Our results suggest that overexpression of RCAS1 may negatively affect the prognosis of human colorectal carcinomas and that RCAS1 may play a role in tumor immune privilege in vivo.


Assuntos
Adenocarcinoma/metabolismo , Antígenos de Neoplasias/metabolismo , Apoptose , Neoplasias Colorretais/metabolismo , Linfócitos do Interstício Tumoral/metabolismo , Adenocarcinoma/mortalidade , Adenocarcinoma/secundário , Idoso , Contagem de Células , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Humanos , Técnicas Imunoenzimáticas , Marcação In Situ das Extremidades Cortadas , Linfócitos do Interstício Tumoral/patologia , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida
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