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1.
Zhonghua Gan Zang Bing Za Zhi ; 22(2): 108-12, 2014 Feb.
Artigo em Zh | MEDLINE | ID: mdl-24735592

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of the magnesium isoglycyrrhizinate plus nucleoside analogues (MGL + NA) combination therapy in patients with chronic hepatitis B using a meta-analysis approach. METHODS: The Chinese Biochemical literature on Disc (CBMDisc) and the Chinese Scientific Journal database, CNKI, were searched for randomized controlled trials (RCTs) of MGL+NA in patients with chronic hepatitis B published between 1995 and 2013. Data related to treatment type (combination therapy vs. mono-therapy) and outcome (markers of efficacy and safety, including levels of hepatitis B virus (HBV) DNA, hepatitis B e antigen (HBeAg), alanine aminotransferase (ALT) and aspartate aminotransferase (AST)). Weighted mean differences (WMD) were calculated and the Peto method was used to determine the relative risk (RR), both with 95% confidence intervals (CIs). RESULTS: Meta-analysis of the six included RCTs of MGL + NA, representing a 704 patients with chronic hepatitis B, showed WMDs for ALT of -12.98 (95% CI: -18.24 to -7.71, P less than 0.01) and for AST of -9.49 (95% CI: -14.53 to -4.45, P = 0.0002) and RRs for HBeAg of 1.79 (95% CI: 1.17 to 2.76, P = 0.008) and for HBV DNA of 1.35 (95% CI: 1.05 to 1.74, P = 0.02). The therapeutic efficacy of MGL+NA combination therapy was better than that of NA mono-therapy (P less than 0.01). CONCLUSION: For patients with chronic hepatitis B, MGL combination therapy may enhance the antiviral efficacy of NA treatment and help to improve liver function during treatment.

2.
Front Med (Lausanne) ; 8: 644376, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777984

RESUMO

Objectives: Autoimmune hepatitis (AIH) can progress into severe outcomes, i.e., decompensated cirrhosis, from remarkable and persistent inflammation in the liver. Considering the energy-expending nature of inflammation, we tried to define the metabolomics signatures of AIH to uncover the underlying mechanisms of cirrhosis development and its metabolic biomarkers. Methods: Untargeted metabolomics analysis was performed on sera samples from 79 AIH patients at the stages (phenotypes) of non-cirrhosis (n = 27), compensated cirrhosis (n = 22), and decompensated cirrhosis (n = 30). Pattern recognition was used to find unique metabolite fingerprints of cirrhosis with or without decompensation. Results: Out of the 294 annotated metabolites identified, 2 metabolic fingerprints were found associated with the development of cirrhosis (independent of the decompensated state, 42 metabolites) and the evolution of decompensated cirrhosis (out of 47 metabolites), respectively. The cirrhosis-associated fingerprints (eigenmetabolite) showed better capability to differentiate cirrhosis from non-cirrhosis patients than the aminotransferase-to-platelet ratio index. From the metabolic fingerprints, we found two pairs of metabolites (Mesobilirubinogen/6-Hydroxynicotinic acid and LysoPA(8:0/0:0)/7alpha-Hydroxycholesterol) calculated as ratio of intensities, which revealed robust abilities to identify cirrhosis or predict decompensated patients, respectively. These phenotype-related fingerprint metabolites featured fundamental energy supply disturbance along with the development of AIH cirrhosis and progression to decompensation, which was characterized as increased lipolysis, enhanced proteolysis, and increased glycolysis. Conclusions: Remodeling of metabolism to meet the liver inflammation-related energy supply is one of the key signatures of AIH in the development of cirrhosis and decompensation. Therefore, drug regulation metabolism has great potential in the treatment of AIH.

3.
Hepatol Commun ; 5(6): 961-975, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34141983

RESUMO

Alcohol-associated liver disease (ALD) is caused by alcohol metabolism's effects on the liver. The underlying mechanisms from a metabolic view in the development of alcohol-associated liver cirrhosis (ALC) are still elusive. We performed an untargeted serum metabolomic analysis in 14 controls, 16 patients with ALD without cirrhosis (NC), 27 patients with compensated cirrhosis, and 79 patients with decompensated ALC. We identified two metabolic fingerprints associated with ALC development (38 metabolites) and those associated with hepatic decompensation (64 metabolites) in ALC. The cirrhosis-associated fingerprint (eigenmetabolite) showed a better capability to differentiate ALC from NC than the aspartate aminotransferase-to-platelet ratio index score. The eigenmetabolite associated with hepatic decompensation showed an increasing trend during the disease progression and was positively correlated with the Model for End-Stage Liver Disease score. These metabolic fingerprints belong to the metabolites in lipid metabolism, amino acid pathway, and intermediary metabolites in the tricarboxylic acid cycle. Conclusion: The metabolomic fingerprints suggest the disturbance of the metabolites associated with cellular energy supply as an underlying mechanism in the development and progression of alcoholic cirrhosis.

4.
Gynecol Oncol ; 118(1): 69-75, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20417958

RESUMO

OBJECTIVE: Exposure to chemotherapy causes various adverse effects on the ovaries including premature ovarian failure and infertility. GnRH antagonist cetrorelix could reverse the ovarian damage during chemotherapy, but the mechanism remains unclear. The objectives of this study were to examine the role of the cetrorelix for prevention of mitochondria-dependent apoptosis in granulosa cells of rats during the treatment with cyclophosphamide(Cy), if the mitochondria-dependent apoptotic process was involved. METHODS: Female SD rats were injected with cetrorelix before and after administration of saline, or Cy. Main outcome measures were the apoptotic indexes, serum hormones, ultrastructure of granulosa cells, mitochondrial membrane potential, the kinetics of cytochrome c (Cyt-c) processing in cells, and apoptotic markers. RESULTS: The ovarian apoptotic indexes as shown by TUNEL assay were reduced by cetrorelix pretreatment and the rats regained normal hormonal profile. The ultrastructure and JC-1 fluorescence intensity assessments showed cetrorelix pretreatment inhibited mitochondrial dysfunction in granulosa cells induced by chemotherapy. Western blot analysis showed that cetrorelix suppressed the release of Cyt-c from mitochondria to cytoplasm. Meanwhile, cetrorelix pretreatment expressed less Bax, caspase-3 and Cyt-c in granulosa cells compared with chemotherapy alone. CONCLUSION: Cetrorelix could reduce the apoptosis in granulosa cells through inhibiting mitochondria-dependent apoptosis triggered by chemotherapy.


Assuntos
Apoptose/efeitos dos fármacos , Ciclofosfamida/farmacologia , Hormônio Liberador de Gonadotropina/análogos & derivados , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Células da Granulosa/efeitos dos fármacos , Antagonistas de Hormônios/farmacologia , Mitocôndrias/efeitos dos fármacos , Animais , Antineoplásicos Alquilantes/farmacologia , Apoptose/fisiologia , Caspase 3/biossíntese , Citocromos c/biossíntese , Citoplasma/metabolismo , Estradiol/sangue , Feminino , Hormônio Liberador de Gonadotropina/farmacologia , Células da Granulosa/citologia , Células da Granulosa/ultraestrutura , Imuno-Histoquímica , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/fisiologia , Progesterona/sangue , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Proteína X Associada a bcl-2/biossíntese
5.
Zhonghua Gan Zang Bing Za Zhi ; 16(2): 93-6, 2008 Feb.
Artigo em Zh | MEDLINE | ID: mdl-18304422

RESUMO

OBJECTIVE: To study the characteristics of the virology background of HLA-A2 restricted HBcAg(18-27) epitope mutations in HBV infected patients in China. METHOD: 30 HBV sequences with different genotypes from Genbank were analyzed by bioinformatics and the mismatched primers were designed for constructing a PCR-RFLP method to screen HBcAg(18-27)V/I in China. The distributions of HBcAg(18-27)V/I of 160 samples with HBV genotype B/C infection from 8 areas in China were screened and analyzed by PCR-RFLP and sequencing. The affinity of HBcAg(18-27)V/I to HLA-A0201 was analyzed through referencing the bioinformatics websites. RESULTS: We successfully constructed a PCR-RFLP method for screening HBcAg(18-27)V/I from genotype B/C, and only 3 samples with HBcAg(18-27)V sequence were found in the 160 samples (3/160, 1.88%). The affinity of HBcAg(18-27)I to HLA-A 0201 was lower than the one of HBcAg(18-27)V through bioinformatic analysis (HLA ligand score was 123 vs 156, and the SYFPEITHI score was 22 vs 24). CONCLUSION: The last amino acid of most HBcAg(18-27) sequences of epidemic HBV strains in China is isoleucine, and not valine. Therefore HBcAg(18-27) sequence background in different HBV genotypes should be thoroughly considered when using it as a reference or control in immunological research about HBV.


Assuntos
Epitopos de Linfócito T/imunologia , Antígenos do Núcleo do Vírus da Hepatite B/genética , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Vírus da Hepatite B , Hepatite B Crônica/imunologia , Hepatite B Crônica/virologia , Adulto , China/epidemiologia , Biologia Computacional , DNA Viral/genética , Feminino , Genótipo , Antígenos HLA-A/imunologia , Vírus da Hepatite B/classificação , Vírus da Hepatite B/imunologia , Hepatite B Crônica/epidemiologia , Humanos , Masculino , Mutação , Análise de Sequência de DNA , Linfócitos T Citotóxicos/imunologia
6.
World J Gastroenterol ; 24(3): 415-423, 2018 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-29391764

RESUMO

AIM: To optimize the hepatobiliary phase delay time (HBP-DT) of Gd-EOB-DTPA-enhanced magnetic resonance imaging (GED-MRI) for more efficient identification of hepatocellular carcinoma (HCC) occurring in different degrees of cirrhosis assessed by Child-Pugh (CP) score. METHODS: The liver parenchyma signal intensity (LPSI), the liver parenchyma (LP)/HCC signal ratios, and the visibility of HCC at HBP-DT of 5, 10, 15, 20, and 25 min (i.e., DT-5, DT-10, DT-15, DT-20, and DT-25 ) after injection of Gd-EOB-DTPA were collected and analyzed in 73 patients with cirrhosis of different degrees of severity (including 42 patients suffering from HCC) and 18 healthy adult controls. RESULTS: The LPSI increased with HBP-DT more significantly in the healthy group than in the cirrhosis group (F = 17.361, P < 0.001). The LP/HCC signal ratios had a significant difference (F = 12.453, P < 0.001) among various HBP-DT points, as well as between CP-A and CP-B/C subgroups (F = 9.761, P < 0.001). The constituent ratios of HCC foci identified as obvious hypointensity (+++), moderate hypointensity (++), and mild hypointensity or isointensity (+/-) kept stable from DT-10 to DT-25: 90.6%, 9.4%, and 0.0% in the CP-A subgroup; 50.0%, 50.0%, and 0.0% in the CP-B subgroup; and 0.0%, 0.0%, and 100.0% in the CP-C subgroup, respectively. CONCLUSION: The severity of liver cirrhosis has significant negative influence on the HCC visualization by GED-MRI. DT-10 is more efficient and practical than other HBP-DT points to identify most of HCC foci emerging in CP-A cirrhosis, as well as in CP-B cirrhosis; but an HBP-DT of 15 min or longer seems more appropriate than DT-10 for visualization of HCC in patients with CP-C cirrhosis.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Hepatite B Crônica/diagnóstico por imagem , Cirrose Hepática/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Adulto , Ductos Biliares/diagnóstico por imagem , Ductos Biliares/patologia , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Meios de Contraste/administração & dosagem , Feminino , Gadolínio DTPA/administração & dosagem , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/patologia , Hepatite B Crônica/virologia , Humanos , Aumento da Imagem/métodos , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/patologia , Cirrose Hepática/virologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Adulto Jovem
7.
Hepatol Int ; 11(3): 221-241, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28405790

RESUMO

Drug-induced liver injury (DILI) is an important clinical problem, which has received more attention in recent decades. It can be induced by small chemical molecules, biological agents, traditional Chinese medicines (TCM), natural medicines (NM), health products (HP), and dietary supplements (DS). Idiosyncratic DILI is far more common than intrinsic DILI clinically and can be classified into hepatocellular injury, cholestatic injury, hepatocellular-cholestatic mixed injury, and vascular injury based on the types of injured target cells. The CSH guidelines summarized the epidemiology, pathogenesis, pathology, and clinical manifestation and gives 16 evidence-based recommendations on diagnosis, differential diagnosis, treatment, and prevention of DILI.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Colestase/induzido quimicamente , Suplementos Nutricionais/efeitos adversos , Hepatopatias/epidemiologia , Antibacterianos/efeitos adversos , Antibacterianos/toxicidade , Anti-Infecciosos/efeitos adversos , Anti-Infecciosos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/fisiopatologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , China/epidemiologia , Colestase/complicações , Colestase/patologia , Diagnóstico Diferencial , Suplementos Nutricionais/toxicidade , Medicamentos de Ervas Chinesas/efeitos adversos , Feminino , Guias como Assunto , Humanos , Incidência , Hepatopatias/patologia , Hepatopatias/fisiopatologia , Hepatopatias/terapia , Masculino , Prognóstico , Fatores de Risco , Índice de Gravidade de Doença
9.
Zhonghua Gan Zang Bing Za Zhi ; 14(1): 23-8, 2006 Jan.
Artigo em Zh | MEDLINE | ID: mdl-16420760

RESUMO

OBJECTIVES: To understand the role cellular immunology plays in the pathogenesis of chronic hepatitis B (CHB) through analysis of T cell receptor (TCR) beta chain variable region gene (BV) family dominant usage and beta chain complementarity determining region3 (CDR3) sequences of peripheral blood mononuclear cells of the patients. METHODS: TCR BV families were amplified by inverse polymerase chain reaction (RT-PCR), and the dominant usage of BV families and CDR3 repertoire were analyzed by immunoscope technology for 8 CHB patients during their acute exacerbations and for 4 healthy blood donors who served as controls. The clonality of the T cells suspected by immunoscope was further confirmed by CDR3 sequencing. RESULTS: The TCR BV CDR3 repertoire of the 4 healthy blood donors showed a Gaussian distribution. In the 8 CHB patients, however, the clonal expansion of T cells showed different TCR BV families with each patient. The T cells of the clonal expansion shared different CDR3 sequences. CONCLUSION: The peripheral blood T cells of CHB patients during their acute exacerbation showed significantly a clonal expansion and their T cell clonal expansion may be stimulated by several HBV epitopes. These results indicate that cellular immunology is involved in the pathogenesis of the liver inflammation process of CHB.


Assuntos
Regiões Determinantes de Complementaridade/genética , Hepatite B Crônica/genética , Receptores de Antígenos de Linfócitos T/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Feminino , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T/genética , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular
10.
Zhonghua Nei Ke Za Zhi ; 44(9): 648-51, 2005 Sep.
Artigo em Zh | MEDLINE | ID: mdl-16202251

RESUMO

OBJECTIVE: To investigate the clinical characteristics of HBeAg-negative and HBeAg-positive chronic hepatitis B (CHB). METHODS: A total of 1686 hospitalized CHB cases were analyzed retrospectively. The serum ALT values, HBV DNA levels and hepatic inflammation and fibrosis were analyzed by their serum HBeAg status. RESULTS: Among the 1686 cases, 628 (37.3%) were HBeAg-negative and 1058 (62.7%) were HBeAg-positive. Compared with HBeAg-positive group, HBeAg-negative group had a lower serum ALT and HBV DNA levels. However, hepatic necroinflammation grading and fibrosis staging in HBeAg-negative group were more advanced than that of HBeAg-positive group. Irrespective to serum HBeAg status, patients with serum HBV DNA less than 10(5)copies/ml, had a lower hepatic necroinflammation activity. CONCLUSIONS: HBeAg-positive CHB is still the predominant form of CHB in Chinese patients. Compared with patients with low HBV replication, patients with active HBV replication had a higher hepatic necroinflammation activity. The liver histological grading and staging in HBeAg-negative CHB patients were more advanced than that in HBeAg-positive patients.


Assuntos
Antígenos E da Hepatite B/sangue , Hepatite B Crônica/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alanina Transaminase/sangue , Criança , Pré-Escolar , Estudos Transversais , DNA Viral/sangue , Feminino , Vírus da Hepatite B/genética , Hepatite B Crônica/imunologia , Hepatite B Crônica/patologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
11.
World J Gastroenterol ; 8(4): 694-8, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12174380

RESUMO

AIM: To explore whether HDV ribozymes have the ability to trans-cleave HCV RNA. METHODS: Three HDV genomic ribozymes were designed and named RzC1, RzC2 and RzC3. The substrate RNA contained HCV RNA 5'-noncoding region and 5'-fragment of C region (5'-NCR-C). All the ribozymes and HCV RNA 5'-NCR-C were obtained by transcription in vitro from their DNA templates, and HCV RNA 5'-NCR-C was radiolabelled at its 5'-end. Under certain pH, temperature, appropriate concentration of Mg(2+) and deionized formamide, these ribozymes were respectively or simultaneously mixed with HCV RNA 5'-NCR-C and reacted for a certain time. The trans-cleavage reaction was stopped at different time points, and the products were separated with polyacrylamide gel electrophoresis (PAGE), displayed by autoradiography. Percentage of trans-cleaved products was measured to indicate the activity of HDV ribozymes. RESULTS: RzC1 and RzC2 could trans-cleave 26 % and 21.8 % of HCV RNA 5'-NCR-C under our reaction conditions with 2.5 mol.L(-1) deionized formamide respectively. The percentage of HCV RNA 5'-NCR-C trans-cleaved by RzC1, RzC2 or combined usage of the three ribozymes increased with time, up to 24.9 %, 20.3 % and 37.3 % respectively at 90 min point. Almost no product from RzC3 was observed. CONCLUSION: HDV ribozymes are able to trans-cleave specifically HCV RNA at certain sites under appropriate conditions, and combination of several ribozymes aiming at different target sites can trans-cleave the substrate more efficiently than using only one of them.


Assuntos
Hepacivirus/genética , Vírus Delta da Hepatite/enzimologia , RNA Catalítico/metabolismo , RNA Viral/metabolismo , Sequência de Bases , Vírus Delta da Hepatite/genética , Humanos , Cinética , Conformação de Ácido Nucleico , RNA Catalítico/química , RNA Catalítico/genética , RNA Viral/química , RNA Viral/genética , Especificidade por Substrato
12.
World J Gastroenterol ; 10(7): 1010-4, 2004 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-15052684

RESUMO

AIM: To study the method of cryopreserving porcine hepatocytes and gel collagen culture measure after its cryopreservation. METHODS: Hepatocytes, isolated from Chinese experimental suckling mini-pigs by two-step perfusion with collagenase using an extra corporeal perfusion apparatus, were cryopreserved with 50 mL/L to 200 mL/L DMSO in liquid nitrogen for 4 mo, then thawed and seeded in 1 or between 2 layers of gel collagen. The expression of porcine albumin message RNA, cellular morphology and content of aspartate aminotransferase (AST) and urea nitrogen (UN) were examined during culture in gel. RESULTS: Viability of 150 mL/L DMSO group thawed hepatocytes was (83+/-4)%, but after purification, its viability was (90+/-5)%, attachment efficiency was (86+/-7)%, the viability of thawed hepatocytes was near to fresh cells. When the thawed hepatocytes were cultivated in gel collagen with culture medium adding epidermal growth factor, the hepatocytes grew in various administrative levels in mixed collagen gel, and bunchy in the sandwich configuration cultures. For up to 10 days' culture, the typical cellular morphological characteristics of cultivated hepatocytes could be observed. The leakage of AST was lower during culture in gel than that in common culture. At the same time, the UN synthesized by cells cultivated in mixed gel collagen was higher than that in other groups. CONCLUSION: Storage in liquid nitrogen can long keep hepatocytes' activities, the concentration of 150 mL/L DMSO is fit for porcine hepatocytes' cryopreservation. Thawed hepatocytes can be cultivated with collagenous matrix, which provides an environment that more closely resembles that in vivo and maintain the expression of certain liver-specific function of hepatocytes.


Assuntos
Colágeno , Criopreservação , Hepatócitos/citologia , Hepatócitos/fisiologia , Animais , Adesão Celular , Sobrevivência Celular , Células Cultivadas , Géis , Suínos , Porco Miniatura
13.
Zhonghua Gan Zang Bing Za Zhi ; 11(3): 156-8, 2003 Mar.
Artigo em Zh | MEDLINE | ID: mdl-12681063

RESUMO

OBJECTIVE: To analyze the cleavage activity of two deoxyribozymes targeting at hepatitis C virus (HCV) RNA in vitro and evaluate their prospects of antiviral therapy. METHODS: Two specific sequences containing 5' ...A / U... 3' in HCV 5'-noncoding region and 5'-fragment of C region (5'-NCR-C) were selected as the target sites, and with the active region of 5'GGCTAGCTACAACGA3', two phosphorothioate deoxyribozymes (TDRz) named as TDRz-127 and TDRz1 were synthesized. HCV RNA 5'-NCR-C was transcribed in vitro from plasmid pHCV-neo which was completely linearized with restriction endonuclease Nar I, and its 5'-end phosphoric acid was deleted by calf intestinal alkaline phosphatase (CIP), then radiolabelled with T4 polynucleotide kinase and gamma-32P-ATP. Under the conditions such as pH 7.5 and a 10 mmol/L Mg2+ concentration, TDRz-127 and TDRz1 were separately (a 5 micromol/L final concentration) or combinedly (each 2.5 micromol/L) mixed with the substrate RNA (200 nmol/L). After denaturation and then renaturation, the reaction systems were incubated in 37 degrees C, and aliquots were removed to terminate the reaction at intended time points. The cleavage products were separated with 8% denaturated polyacrylamide gel electrophoresis and displayed by autoradiography. Finally, the optical density of each product band was measured with Gel Documentation-Analyzing Systems for calculating the percentages of cleaved HCV 5'-NCR-C. RESULTS: After reaction for 15, 30, 45, 60, 75 and 90 min under the adopted conditions, about 8.3%, 16.1%, 24.3%, 26.2%, 29.4% and 31.1% of HCV 5'-NCR-C was cleaved by TDRz-127 respectively; 7.4%, 13.0%, 15.6%, 18.7%, 19.4% and 20.3% by TDRz1; and 15.1%, 29.6%, 37.8%, 39.1%, 41.5%, 42.6% by combining the two TDRzs. CONCLUSIONS: Cleavage percentage of both TDRz-127 and TDRz1 increases with the time, and the effect of combining the two TDRzs is better than that of anyone.


Assuntos
DNA Catalítico/genética , Hepacivirus/genética , RNA Viral/metabolismo , Regiões 5' não Traduzidas/metabolismo , Sequência de Bases , DNA Catalítico/metabolismo , Hepacivirus/enzimologia , Humanos , Dados de Sequência Molecular , Processamento Pós-Transcricional do RNA , RNA Catalítico/metabolismo , Fatores de Poliadenilação e Clivagem de mRNA/genética , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo
14.
World J Hepatol ; 6(6): 419-25, 2014 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-25018852

RESUMO

The prevalence of hepatitis C virus (HCV) infection in patients on maintenance hemodialysis (MHD) is relatively higher than those without MHD. Chronic HCV infection detrimentally affects the life quality and expectancy, leads to renal transplant rejection, and increases the mortality of MHD patients. With the application of erythropoietin to improve uremic anemia and avoid blood transfusion, the new HCV infections during MHD in recent years are mainly caused by the lack of stringent universal precautions. Strict implementation of universal precautions for HCV transmission has led to markedly decreased HCV infections in many hemodialysis units, but physicians still should be alert for the anti-HCV negative HCV infection and occult HCV infection in MHD patients. Standard interferon alpha and pegylated interferon alpha monotherapies at a reduced dose are currently the main treatment strategies for MHD patients with active HCV replication, but how to increase the sustained virological response and decrease the side effects is the key problem. IFNα-free treatments with two or three direct-acting antivirals without ribavirin in MHD patients are waiting for future investigations.

15.
IEEE Trans Neural Netw Learn Syst ; 23(5): 800-11, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-24806128

RESUMO

The v-support vector classification (v-SVC) proposed by Schölkopf has the advantage of using a regularization parameter v for controlling the number of support vectors and margin errors. However, compared to C-SVC, its formulation is more complicated, and to date there are no effective methods for computing its regularization path. In this paper, we propose a new regularization path algorithm, which is designed on the basis of a modified formulation of v-SVC and traces the solution path with respect to the parameter v. Through theoretical analysis and confirmatory experiments, we show that our algorithm can avoid the infeasible updating path under several assumptions (i.e., Assumptions 1 and 2), and fit the entire solution path in a finite number of steps. When the regularization path of v-SVC is available, a novel approach proposed by Yang and Ong can be applied to obtain the global optimal solution of common validation functions for v-SVC, and the computation for the whole process is minimal. Numerical experiments show that it is more efficient than various kinds of grid search methods for selecting the optimal regularization parameter v.

16.
Neural Netw ; 27: 51-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22057091

RESUMO

The ν-Support Vector Machine (ν-SVM) for classification proposed by Schölkopf et al. has the advantage of using a parameter ν on controlling the number of support vectors and margin errors. However, comparing to standard C-Support Vector Machine (C-SVM), its formulation is more complicated, up until now there are no effective methods on solving accurate on-line learning for it. In this paper, we propose a new effective accurate on-line algorithm which is designed based on a modified formulation of the original ν-SVM. The accurate on-line algorithm includes two special steps: the first one is relaxed adiabatic incremental adjustments; the second one is strict restoration adjustments. The experiments on several benchmark datasets demonstrate that using these two steps the accurate on-line algorithm can avoid the infeasible updating path as far as possible, and successfully converge to the optimal solution. It achieves the fast convergence especially on the Gaussian kernel and is faster than the batch algorithm.


Assuntos
Simulação por Computador , Armazenamento e Recuperação da Informação , Máquina de Vetores de Suporte
18.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 26(12): 1200-2, 2010 Dec.
Artigo em Zh | MEDLINE | ID: mdl-21138683

RESUMO

AIM: To construct the eukaryotic expression vector of human CXCR4 and CCR5, transfect SKOV3 cells with them. METHODS: The cDNA of CXCR4 and CCR5 was amplified by RT-PCR. After purification, the gene was cloned into a vector pEGFP. The sequence of inserted CXCR4 and CCR5 gene fragment was identified by enzyme digestion of EcoR I/Sal I and sequencing, and then the recombinant plasmid was transfected into SKOV3 cells which did not express CXCR4 and CCR5 by lipofectamine-mediated gene transfection method. The SKOV3 cells transfected with CXCR4 and CCR5 were examined by FCM. RESULTS: Vectors pEGFP-CXCR4 and pEGFP-CCR5 were obtained. Cell clones which were screened by G418 were obtained. The results of FCM indicatedthat transfected SKOV3 cells expressed CXCR4 and CCR5. CONCLUSION: SKOV3 cells that can express CXCR4 and CCR5 protein stably have been established successfully, which facilitates the researches of epithelial ovarian.


Assuntos
Vetores Genéticos/genética , Engenharia de Proteínas/métodos , Receptores CCR5/genética , Receptores CXCR4/genética , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Plasmídeos/genética , Reação em Cadeia da Polimerase , Transfecção
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