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1.
BMC Infect Dis ; 20(1): 264, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32245397

RESUMO

BACKGROUND: Hepatitis C virus (HCV) infection is a leading cause of chronic liver disease and hepatocellular carcinoma. Treatment with first generation protease inhibitors (PI) + peg-interferon (pegIFN) and ribavirin (RBV) achieved sustained virologic response (SVR) rates of 65-75% but was associated with multiple side effects. The aim of this study was to evaluate safety and efficacy of Ombitasvir/Paritaprevir/Ritonavir and Dasabuvir (3D) ± RBV in HCV genotype 1 patients that failed previous treatment with first generation PIs. METHODS: An investigator-initiated, open-label, multi-centre clinical trial. HCV Genotype 1 patients who were previously null/partial responders or relapsers to telaprevir, boceprevir or simepravir+pegIFN/RBV and met eligibility criteria were included. 3D ± RBV were administrated for 12 or 24 weeks according to label. The primary outcome was antiviral response (SVR12); Secondary outcomes were patient reported outcomes, adverse events and resistance associated variants. RESULTS: Thirty-nine patients initiated treatment according to study protocol (59% men, age 54.0 ± 8.7 years, BMI 28.7 ± 4.5 kg/m2). Thirty-seven (94.9%) completed the study. Thirty-five patients had genotype 1b (9 cirrhotics) and 4 had genotype 1a (2 cirrhotics). Intention-to-treat SVR12 was 92.3% and per-protocol SVR12 was 97.3%. The rate of advanced fibrosis (FibroScan® score F3-4) declined from 46.2 to 25.7% (P = 0.045). Abnormal ALT levels declined from 84.6 to 8.6% (P < 0.001). Seven patients (17.9%) experienced serious adverse events (3 Psychiatric admissions, 1 pneumonia, 1 ankle fracture, 2 palpitations), and 12 patients (30.8%) experienced self-reported adverse events, mostly weakness. CONCLUSION: 3D ± RBV is safe and effective in achieving SVR among patients with HCV genotype 1 who failed previous first-generation PI treatment. TRIAL REGISTRATION: NCT02646111 (submitted to ClinicalTrials.gov, December 28, 2015).


Assuntos
Anilidas/uso terapêutico , Antivirais/uso terapêutico , Carbamatos/uso terapêutico , Hepatite C/tratamento farmacológico , Compostos Macrocíclicos/uso terapêutico , Inibidores de Proteases/uso terapêutico , Ribavirina/uso terapêutico , Ritonavir/uso terapêutico , Sulfonamidas/uso terapêutico , Uracila/análogos & derivados , 2-Naftilamina , Anilidas/efeitos adversos , Antivirais/efeitos adversos , Carbamatos/efeitos adversos , Ciclopropanos , Quimioterapia Combinada , Feminino , Genótipo , Hepatite C/virologia , Humanos , Lactamas Macrocíclicas , Compostos Macrocíclicos/efeitos adversos , Masculino , Pessoa de Meia-Idade , Prolina/análogos & derivados , Estudos Prospectivos , Inibidores de Proteases/efeitos adversos , Ribavirina/efeitos adversos , Ritonavir/efeitos adversos , Sulfonamidas/efeitos adversos , Resultado do Tratamento , Uracila/efeitos adversos , Uracila/uso terapêutico , Valina
2.
J Hepatol ; 71(4): 660-665, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31195062

RESUMO

BACKGROUND & AIMS: Although off-label use of sofosbuvir-containing regimens occurs regularly in patients with hepatitis C virus (HCV) infection undergoing dialysis for severe renal impairment or end-stage renal disease (ESRD), these regimens are not licensed for this indication, and there is an absence of dosing recommendations in this population. This study evaluated the safety and efficacy of sofosbuvir/velpatasvir in patients with HCV infection with ESRD undergoing dialysis. METHODS: In this phase II, single-arm study, 59 patients with genotype 1-6 HCV infection with ESRD undergoing hemodialysis or peritoneal dialysis received open-label sofosbuvir/velpatasvir (400 mg/100 mg) once daily for 12 weeks. Patients were HCV treatment naive or treatment experienced without cirrhosis or with compensated cirrhosis. Patients previously treated with any HCV NS5A inhibitor were not eligible. The primary efficacy endpoint was the proportion of patients achieving sustained virologic response (SVR) 12 weeks after discontinuation of treatment (SVR12). The primary safety endpoint was the proportion of patients who discontinued study drug due to adverse events. RESULTS: Overall, 56 of 59 patients achieved SVR12 (95%; 95% CI 86-99%). Of the 3 patients who did not achieve SVR12, 2 patients had virologic relapse determined at post-treatment Week 4 (including 1 who prematurely discontinued study treatment), and 1 patient died from suicide after achieving SVR through post-treatment Week 4. The most common adverse events were headache (17%), fatigue (14%), nausea (14%), and vomiting (14%). Serious adverse events were reported for 11 patients (19%), and all were deemed to be unrelated to sofosbuvir/velpatasvir. CONCLUSIONS: Treatment with sofosbuvir/velpatasvir for 12 weeks was safe and effective in patients with ESRD undergoing dialysis. LAY SUMMARY: Sofosbuvir/velpatasvir is a combination direct-acting antiviral that is approved for treatment of patients with hepatitis C virus (HCV) infection. Despite the lack of dosing recommendations, sofosbuvir-containing regimens (including sofosbuvir/velpatasvir) are frequently used for HCV-infected patients undergoing dialysis. This study evaluated the safety and efficacy of sofosbuvir/velpatasvir for 12 weeks in patients with HCV infection who were undergoing dialysis. Treatment with sofosbuvir/velpatasvir was safe and well tolerated, resulting in a cure rate of 95% in patients with HCV infection and end-stage renal disease. Clinical Trial Number: NCT03036852.


Assuntos
Carbamatos , Hepatite C Crônica , Compostos Heterocíclicos de 4 ou mais Anéis , Falência Renal Crônica , Diálise Renal/métodos , Sofosbuvir , Antivirais/administração & dosagem , Antivirais/efeitos adversos , Carbamatos/administração & dosagem , Carbamatos/efeitos adversos , Combinação de Medicamentos , Monitoramento de Medicamentos/métodos , Feminino , Hepacivirus/genética , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Compostos Heterocíclicos de 4 ou mais Anéis/administração & dosagem , Compostos Heterocíclicos de 4 ou mais Anéis/efeitos adversos , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Cirrose Hepática/diagnóstico , Masculino , Pessoa de Meia-Idade , Sofosbuvir/administração & dosagem , Sofosbuvir/efeitos adversos , Resposta Viral Sustentada , Resultado do Tratamento
3.
Am J Pathol ; 187(1): 122-133, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27842214

RESUMO

Sortilin, a member of the vacuolar protein sorting 10 domain receptor family, traffics newly synthesized proteins from the trans-Golgi network to secretory pathways, endosomes, and cell surface. Sortilin-trafficked molecules, including IL-6 and acid sphingomyelinase (aSMase), mediate cholangiocyte proliferation and liver inflammation, hepatic stellate cell activation, hepatocyte apoptosis, and fibrosis. Based on these sortilin-regulated functions, we investigated its role in biliary damage leading to hepatocellular injury and fibrosis. Sortilin-/- mice displayed impaired inflammation and ductular reaction 3 days after bile duct ligation (BDL), as demonstrated by reduced cholangiocyte proliferation and activation and reduced serum IL-6. Interestingly, liver fibrosis was reduced in Sortilin-/- mice after both BDL and carbon tetrachloride treatment, in line with attenuated in vitro activation of Sortilin-/- hepatic stellate cells. Sortilin-/- hepatic aSMase activity was reduced in the BDL and carbon tetrachloride models and accompanied by reduced in vivo hepatocyte apoptosis. In addition, wild type (WT), but not Sortilin-/- hepatocytes, had increased aSMase-dependent susceptibility to bile acid-induced apoptosis in vitro. Mechanistically, short-term IL-6 neutralization in bile duct-ligated WT mice decreased hepatic inflammation and reactive cholangiocyte-derived cytokines and chemokines, without affecting fibrosis, whereas pharmacological inhibition of aSMase activity was not sufficient to attenuate hepatic fibrosis. Only combined IL-6 and aSMase inhibition significantly reduced fibrosis in bile duct-ligated WT mice. We conclude that sortilin regulates cholestatic liver damage and fibrosis via effects on both aSMase activity and serum IL-6.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/deficiência , Apoptose , Ductos Biliares/patologia , Colestase/complicações , Hepatócitos/patologia , Cirrose Hepática/patologia , Fígado/lesões , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Proliferação de Células , Quimiocinas/metabolismo , Colestase/patologia , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Hepatócitos/metabolismo , Inflamação/patologia , Interleucina-6/metabolismo , Ligadura , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/complicações , Cirrose Hepática/metabolismo , Camundongos Endogâmicos C57BL , Testes de Neutralização , Fenótipo , Esfingomielina Fosfodiesterase/metabolismo
4.
World J Gastroenterol ; 22(12): 3418-31, 2016 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-27022224

RESUMO

AIM: To evaluate daclatasvir vs telaprevir, each combined with peginterferon alfa-2a/ribavirin (pegIFN/RBV), in treatment-naive hepatitis C virus (HCV) genotype (GT) 1-infected patients. METHODS: In this phase 3, randomized, open-label, noninferiority study, 602 patients were randomly assigned (2:1) to daclatasvir vs telaprevir, stratified by IL28B rs12979860 host genotype (CC vs non-CC), cirrhosis status (compensated cirrhosis vs no cirrhosis), and HCV GT1 subtype (GT1a vs GT1b). Patients were selected by study inclusion criteria from a total of 793 enrolled patients. Patients received daclatasvir 60 mg once daily or telaprevir 750 mg 3 times daily plus pegIFN/RBV. Daclatasvir recipients received 24 wk of daclatasvir plus pegIFN/RBV; those without an extended rapid virologic response (eRVR; undetectable HCV-RNA at weeks 4 and 12) received an additional 24 wk of pegIFN/RBV. Telaprevir-treated patients received 12 wk of telaprevir plus pegIFN/RBV followed by 12 (with eRVR) or 36 (no eRVR) wk of pegIFN/RBV. The primary objective was to compare for noninferiority of sustained virologic response rates at posttreatment week 12 (SVR12) in GT1b-infected patients. Key secondary objectives were to demonstrate that the rates of anemia (hemoglobin < 10 g/dL) and rash-related events, through week 12, were lower with daclatasvir + pegIFN/RBV than with telaprevir + pegIFN/RBV among GT1b-infected patients. Resistance testing was performed using population-based sequencing of the NS5A region for all patients at baseline, and for patients with virologic failure or relapse and HCV-RNA ≥ 1000 IU/mL, to investigate any link between NS5A polymorphisms associated with daclatasvir resistance and virologic outcome. RESULTS: Patient demographics and disease characteristics were generally balanced across treatment arms; however, there was a higher proportion of black/African Americans in the daclatasvir groups (6.0% and 8.2% in the GT1b and GT1a groups, respectively) than in the telaprevir groups (2.2% and 3.0%). Among GT1b-infected patients, daclatasvir plus pegIFN/RBV was noninferior to telaprevir plus pegIFN/RBV for SVR12 [85% (228/268) vs 81% (109/134); difference, 4.3% (95%CI: -3.3% to 11.9%)]. Anemia (hemoglobin < 10 g/dL) was significantly less frequent with daclatasvir than with telaprevir [difference, -29.1% (95%CI: -38.8% to -19.4%)]. Rash-related events were also less common with daclatasvir than with telaprevir, but the difference was not statistically significant. In GT1a-infected patients, SVR12 was 64.9% with daclatasvir and 69.7% with telaprevir. Among both daclatasvir and telaprevir treatment groups, across GT1b- or GT1a-infected patients, lower response rates were observed in patients with IL28B non-CC and cirrhosis - factors known to affect response to pegIFN/RBV. Consistent with these observations, a multivariate logistic regression analysis in GT1b-infected patients demonstrated that SVR12 was associated with IL28B host genotype (CC vs non-CC, P = 0.011) and cirrhosis status (absent vs present, P = 0.031). NS5A polymorphisms associated with daclatasvir resistance (at L28, R30, L31, or Y93) were observed in 17.3% of GT1b-infected patients at baseline; such variants did not appear to be absolute predictors of failure since 72.1% of these patients achieved SVR12 compared with 86.9% without these polymorphisms. Among GT1b-infected patients, treatment was completed by 85.4% (229/268) in the daclatasvir group, and by 85.1% (114/134) in the telaprevir group, and among GT1a-infected patients, by 67.2% (90/134) and 69.7% (46/66), respectively. Discontinuations (of all 3 agents) due to an AE were more frequent with telaprevir than with daclatasvir, whereas discontinuations due to lack of efficacy were more frequent with daclatasvir, due, in part, to differences in futility criteria. CONCLUSION: Daclatasvir plus pegIFN/RBV demonstrated noninferiority to telaprevir plus pegIFN/RBV for SVR12 and was well-tolerated in treatment-naive GT1b-infected patients, supporting the use of daclatasvir with other direct-acting antivirals.


Assuntos
Antivirais/uso terapêutico , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Imidazóis/uso terapêutico , Interferon-alfa/uso terapêutico , Oligopeptídeos/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Adolescente , Adulto , Idoso , Antivirais/efeitos adversos , Carbamatos , Farmacorresistência Viral/genética , Quimioterapia Combinada , Feminino , Genótipo , Hepacivirus/genética , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/genética , Hepatite C Crônica/virologia , Humanos , Imidazóis/efeitos adversos , Interferon-alfa/efeitos adversos , Interferons , Interleucinas/genética , Masculino , Pessoa de Meia-Idade , Oligopeptídeos/efeitos adversos , Polietilenoglicóis/efeitos adversos , Polimorfismo Genético , Pirrolidinas , RNA Viral/sangue , RNA Viral/genética , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Ribavirina/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Valina/análogos & derivados , Carga Viral , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/genética , Adulto Jovem
5.
PLoS One ; 8(10): e76541, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24098526

RESUMO

Peroxisome proliferator activator receptors (PPAR) ligands such as 15-Δ12,13-prostaglandin L(2) [PJ] and all trans retinoic acid (ATRA) have been shown to inhibit the development of liver fibrosis. The role of ligands of retinoic X receptor (RXR) and its ligand, 9-cis, is less clear. The purpose of this study was to investigate the effects of combined treatment of the three ligends, PJ, ATRA and 9-cis, on key events during liver fibrosis in rat primary hepatic stellate cells (HSCs). We found that the anti-proliferative effect of the combined treatment of PJ, ATRA and 9-cis on HSCs was additive. Further experiments revealed that this inhibition was due to cell cycle arrest at the G0/G1 phase as demonstrated by FACS analysis. In addition, the combined treatment reduced cyclin D1 expression and increased p21 and p27 protein levels. Furthermore, we found that the three ligands down regulated the phosphorylation of mTOR and p70(S6K). The activation of HSCs was also inhibited by the three ligands as shown by inhibition of vitamin A lipid droplets depletion from HSCs. Studies using real time PCR and western blot analysis showed marked inhibition of collagen Iα1 and αSMA by the combination of the three ligands. These findings suggest that the combined use of PJ, ATRA and 9-cis causes inhibition of cell proliferation by cell cycle arrest and down-regulation of fibrotic markers to a greater extent compared to each of the ligands alone.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Células Estreladas do Fígado/efeitos dos fármacos , Prostaglandina D2/análogos & derivados , Transdução de Sinais/efeitos dos fármacos , Tretinoína/farmacologia , Actinas/antagonistas & inibidores , Actinas/genética , Actinas/metabolismo , Alitretinoína , Animais , Proliferação de Células/efeitos dos fármacos , Colágeno Tipo I/antagonistas & inibidores , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Ciclina D1/antagonistas & inibidores , Ciclina D1/genética , Ciclina D1/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/agonistas , Inibidor de Quinase Dependente de Ciclina p27/genética , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Sinergismo Farmacológico , Fase G1/efeitos dos fármacos , Fase G1/genética , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Masculino , PPAR gama/antagonistas & inibidores , PPAR gama/genética , PPAR gama/metabolismo , Cultura Primária de Células , Prostaglandina D2/farmacologia , Ratos , Ratos Wistar , Receptores do Ácido Retinoico/antagonistas & inibidores , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/metabolismo , Receptores X de Retinoides/antagonistas & inibidores , Receptores X de Retinoides/genética , Receptores X de Retinoides/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/antagonistas & inibidores , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Proteínas rho de Ligação ao GTP/agonistas , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismo
6.
World J Gastroenterol ; 19(2): 241-8, 2013 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-23345947

RESUMO

AIM: To examine whether the administration of atorvastatin and rosuvastatin would prevent experimentally-induced hepatic cirrhosis in rats. METHODS: Liver cirrhosis was induced by injections of thioacetamide (TAA). Rats were treated concurrently with TAA alone or TAA and either atorvastatin (1,10 and 20 mg/kg) or rosuvastatin (1, 2.5, 5, 10 and 20 mg/kg) given daily by nasogastric gavage. RESULTS: Liver fibrosis and hepatic hydroxyproline content, in the TAA-treated group was significantly higher than those of the controls [11.5 ± 3.2 vs 2.6 ± 0.6 mg/g protein (P = 0.02)]. There were no differences in serum aminotransferase levels in the TAA controls compared to all the groups treated concomitantly by statins. Both statins used in our study did not prevent liver fibrosis or reduce portal hypertension, and had no effect on hepatic oxidative stress. Accordingly, the hepatic level of malondialdehyde was not lower in those groups treated by TAA + statins compared to TAA only. In vitro studies, using the BrdU method have shown that atorvastatin had no effect of hepatic stellate cells proliferation. Nevertheless, statin treatment was not associated with worsening of liver damage, portal hypertension or survival rate. CONCLUSION: Atorvastatin or rosuvastatin did not inhibit TAA-induced liver cirrhosis or oxidative stress in rats. Whether statins may have therapeutic applications in hepatic fibrosis due to other etiologies deserve further investigation.


Assuntos
Fluorbenzenos/uso terapêutico , Ácidos Heptanoicos/uso terapêutico , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/prevenção & controle , Pirimidinas/uso terapêutico , Pirróis/uso terapêutico , Sulfonamidas/uso terapêutico , Tioacetamida/efeitos adversos , Animais , Atorvastatina , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Fluorbenzenos/administração & dosagem , Fluorbenzenos/farmacologia , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/patologia , Ácidos Heptanoicos/administração & dosagem , Ácidos Heptanoicos/farmacologia , Hipertensão Portal/induzido quimicamente , Hipertensão Portal/epidemiologia , Hipertensão Portal/prevenção & controle , Técnicas In Vitro , Incidência , Injeções , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/epidemiologia , Cirrose Hepática/prevenção & controle , Masculino , Estresse Oxidativo/fisiologia , Pirimidinas/administração & dosagem , Pirimidinas/farmacologia , Pirróis/administração & dosagem , Pirróis/farmacologia , Ratos , Ratos Wistar , Rosuvastatina Cálcica , Sulfonamidas/administração & dosagem , Sulfonamidas/farmacologia
7.
Clin Nutr ; 30(1): 6-19, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20619513

RESUMO

OBJECTIVES: The pharmacologic approach to disease management has not (as of yet) demonstrated safety and efficacy in nonalcoholic fatty liver disease (NAFLD). The current article introduces the long-chain omega-3 polyunsaturated fatty acids (LC-ω3s), and reviews the evidence and mechanisms by which their increased intake or supplementation may ameliorate NAFLD. METHODS: A literature search was performed through Ovid Medline, using such terms as NAFLD, NASH, nonalcoholic, steatosis, polyunsaturated fatty acids, fish oil and omega-3. RESULTS: The LC-ω3s display pleiotropic properties that are of benefit in cardiovascular disease. Deficiency of omega-3 fatty acids results in hepatic steatosis, whereas fish oil displays powerful hypotriglyceridemic properties. Intake and/or metabolism of omega-3 fatty acids are commonly impaired in NAFLD patients. A number of pre-clinical and clinical studies have demonstrated an ameliorative effect of supplemental fish oil, seal oil and purified LC-ω3s in reducing hepatic lipid content in NAFLD. There is less evidence that hepatic inflammation and fibrosis are safely reduced by LC-ω3s. CONCLUSIONS: Supplementation of LC-ω3s appears to safely reduce nutritional hepatic steatosis in adults. Whether other histopatholgic features of NAFLD also respond to LC-ω3s is being addressed by clinical trials. Any recommendation for omega-3 supplementation in NAFLD/NASH is contingent on these results.


Assuntos
Ácidos Graxos Ômega-3/uso terapêutico , Óleos de Peixe/uso terapêutico , Fenômenos Fisiológicos da Nutrição , Ensaios Clínicos como Assunto , Suplementos Nutricionais , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/metabolismo , Humanos , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica
8.
Ciênc. rural ; 41(1): 17-24, 2011. tab
Artigo em Português | LILACS | ID: lil-571472

RESUMO

O objetivo deste trabalho foi avaliar o sistema CLEARFIELD® quanto ao controle do arroz-vermelho, influência sobre a produtividade, bem como a fitotoxicidade ocasionada pelo possível residual no solo da mistura formulada de imazethapyr e imazapic em genótipo de arroz tolerante (IRGA 422CL) e não-tolerante (IRGA 417), os quais serviram como plantas indicadoras. O delineamento experimental foi de blocos ao acaso em esquema bifatorial (4x3) com parcelas subdivididas, sendo as parcelas principais representadas pela rotação entre arroz tolerante (IRGA 422CL) e o arroz não-tolerante a imidazolinonas (IRGA 417). Nas sub-parcelas foram aplicados os tratamentos para o controle de arroz-vermelho em diferentes épocas de aplicação (pós-emergência (V4), pré+ pós emergência (no dia da semeadura + V4). A fitotoxicidade foi caracterizada com base na cor das folhas, largura, crescimento e desenvolvimento do limbo foliar. Observou-se que a fitotoxicidade foi maior quando o herbicida foi aplicado em pós-emergência permanecendo seus efeitos até 383 dias após a aplicação. O controle de arroz-vermelho não é eficiente com a utilização de apenas um ano agrícola do sistema CLEARFIELD® e o melhor nível de controle e produtividade foi obtido após dois ou três anos consecutivos desse sistema.


The objective of this study was to evaluate the CLEARFIELD ® system regarding the control of red rice, influences on productivity, as well as the possible phytotoxicity caused by carryover soil formulated mixture of imazethapyr and imazapic in tolerant rice genotype (IRGA 422CL) and non-tolerant (IRGA 417), which served as indicator plants. The experimental design was randomized blocks in a factorial scheme (4x3) with subplots, the main plots represented by rotating tolerant rice (IRGA 422CL) and rice not tolerant to imidazolinone (IRGA 417). In sub-plot treatments were applied to control red rice in different stages of the post-emergence (V4), pre + post emergence (day of seeding V4). Phytotoxicity was characterized based on the color of the leaves, width, growth and development of the leaf. It was observed that phytotoxicity was greater when the herbicide was applied post-emergence, effects remaining until 383 days after application. The control of red rice is not efficient with the use of only one agricultural year of CLEARFIELD® system and the best level of control and yield was obtained after two or three consecutive years of this system.

9.
Dig Dis Sci ; 55(2): 268-75, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19241163

RESUMO

BACKGROUND/AIMS: The aims of the present study were to elucidate whether oxidative stress has a role in Con A-induced hepatitis and to examine if antioxidants may protect against liver damage in this model. METHODS: Hepatitis was induced in Balb/c mice by administration of Con A (18 mg/kg) to the tail vein. Liver enzymes and histology were determined 24 h after Con A injection. Tumor necrosis factor alpha (TNFalpha) and interleukin-10 (IL-10) levels were assayed 2 h after Con A injection. Hepatic malondialdehyde levels were measured at 1, 3, 8, 12, 18, and 24 h after Con A injection in order to examine the timing of free-radicals formation. Nuclear factor kappa B (NF-kappabeta) activation was determined by electrophoresis mobility shift assay (EMSA) 1 and 2 h after Con A injection. In separate experiments, mice were pretreated with either dimethylsulfoxide or dimethylthiourea before Con A inoculation. The antioxidant and NF-kappabeta inhibitor pyrrolidine dithiocarbamate (PDTC) was used as positive control. RESULTS: Hepatic malondialdehyde levels increased 12, 18, and 24 h after Con A inoculation but not earlier. Serum levels of liver enzymes and TNFalpha, hepatic malondialdehyde, and protein carbonyls and the histologic necroinflammatory score were significantly reduced in the antioxidants-treated mice, while IL-10 levels were increased. Dimethylsulfoxide, dimethylthiourea, and PDTC inhibited oxidative stress, but only PDTC inhibited Con A-induced NF-kappaB activation. CONCLUSIONS: Reactive oxygen species play a role in immune-mediated Con A-induced hepatitis probably secondary to immune-mediated liver damage. Scavenging of reactive oxygen species by antioxidants prevents hepatitis independently of NF-kappaB inhibition and may be a new therapeutic target in this experimental model.


Assuntos
Antioxidantes/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Concanavalina A/toxicidade , Sequestradores de Radicais Livres/uso terapêutico , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Dimetil Sulfóxido/uso terapêutico , Modelos Animais de Doenças , Ensaio de Desvio de Mobilidade Eletroforética , Ensaio de Imunoadsorção Enzimática , Interleucina-10/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/efeitos dos fármacos , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Prolina/análogos & derivados , Prolina/uso terapêutico , Tiocarbamatos/uso terapêutico , Tioureia/análogos & derivados , Tioureia/uso terapêutico , Fator de Necrose Tumoral alfa/sangue
10.
Dig Dis Sci ; 54(2): 292-9, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18594976

RESUMO

Peroxisome proliferator activator receptor (PPAR) ligands prevent liver fibrosis, while the role of all-trans retinoic acid (ATRA) and its metabolite 9-cis retinoic acid (9-cis RA) is less clear. We have investigated the ability of the combination of PPAR gamma ligand rosiglitazone (RSG) and of ATRA to prevent liver fibrosis. In vivo treatment with RSG or ATRA reduced fibrotic nodules, spleen weight, and hydroxyproline levels in rat model of thioacetamide-induced liver fibrosis. The combination of ATRA + RSG caused the strongest inhibition, accompanied by decreased expression of collagen I, alpha-smooth muscle actin, TGF beta 1, and TNFalpha. In vitro studies showed that PPAR gamma ligand 15-deoxy-Delta 12,14-prostaglandin J(2)[PJ(2)] and RXR ligand 9-cis RA or PJ(2) and ATRA inhibited proliferation of hepatic stellate cells HSC-T6. 9-cis RA inhibited c-jun levels and also inhibited expression of its receptor RXR alpha in HSC-T6 cells. The combination of PPAR-gamma and RAR agonists demonstrated an additive effect in the inhibition of TAA-induced hepatic fibrosis, due to inhibition of HSC proliferation and reduction of profibrotic TGF beta 1 and proinflammatory TNFalpha.


Assuntos
Células Estreladas do Fígado/efeitos dos fármacos , Cirrose Hepática Experimental/prevenção & controle , PPAR gama/agonistas , Receptores X de Retinoides/agonistas , Tiazolidinedionas/farmacologia , Tretinoína/farmacologia , Alitretinoína , Animais , Proliferação de Células/efeitos dos fármacos , Colágeno Tipo I/metabolismo , Citocinas/metabolismo , Sinergismo Farmacológico , Cirrose Hepática Experimental/induzido quimicamente , Masculino , Prostaglandina D2/análogos & derivados , Prostaglandina D2/farmacologia , Prostaglandina D2/uso terapêutico , Proteínas Proto-Oncogênicas c-jun/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores X de Retinoides/metabolismo , Rosiglitazona , Tiazolidinedionas/uso terapêutico , Tioacetamida/toxicidade , Tretinoína/uso terapêutico
11.
J Gastroenterol Hepatol ; 22(12): 2189-94, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18031379

RESUMO

BACKGROUND AND AIM: It has been shown in previous studies that hypothyroidism prevents the development of liver fibrosis in bile duct ligated rats and in rats chronically treated with thioacetamide (TAA). In recent years, regression of liver fibrosis (occurring spontaneously or during treatment) has been demonstrated in rodent models such as bile duct ligation and CCl(4) administration. Therefore, in the present study, the potential therapeutic effect of hypothyroidism on liver fibrosis was investigated. METHODS: Liver fibrosis was induced in rats by administration of TAA (200 mg/kg, i.p., twice weekly) for 12 weeks. Hypothyroidism was then induced by either methimazole (0.04%) or propylthiouracil (0.05%) administered in drinking water for 8 weeks. Control euthyroid rats received normal drinking water. Hypothyroidism was confirmed by a significant elevation of serum thyroid-stimulating hormone levels. RESULTS: Eight weeks after the cessation of TAA administration, spleen weight, histological score of liver fibrosis, and hepatic hydroxyproline content were significantly lower in both groups of hypothyroid rats as compared to euthyroid controls (P < 0.001). In vitro studies using the rat hepatic stellate cell line HSC-T6 using northern blot analysis and zymography, respectively, showed that high concentrations of triiodotyronine (T(3)) enhanced transforming growth factor (TGF)-beta-induced collagen I gene expression, and reduced metalloproteinase (MMP)-2 secretion, implying that reducing the levels of T(3) may contribute to resolution of fibrosis. Additionally, low T(3) concentration inhibited HSC-T6 proliferation. CONCLUSION: Pharmacologically induced hypothyroidism accelerates the resolution of liver fibrosis in rats. This beneficial effect may in part be due to prevention of T(3)-induced stimulation of collagen synthesis and reduction of MMP-2 secretion.


Assuntos
Hipotireoidismo/complicações , Cirrose Hepática/complicações , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Hepatócitos/metabolismo , Hipotireoidismo/induzido quimicamente , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Ratos , Ratos Wistar , Fator de Crescimento Transformador beta/farmacologia , Tri-Iodotironina/farmacologia
13.
Liver Int ; 27(3): 373-83, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17355460

RESUMO

BACKGROUND AND AIM: Curcumin, the major polyphenolic compound in turmeric, has been shown to attenuate hepatic damage in several animal models of liver injury. The aim of the present study was to examine the efficacy of curcumin in preventing thioacetamide-induced cirrhosis and to unravel the mechanism of curcumin's effect on hepatic fibrosis in rats. METHODS: Liver cirrhosis was induced by thioacetamide (TAA; 200 mg/kg, i.p.) twice weekly for 12 weeks. One group of rats concomitantly received curcumin (300 mg/kg/day, by gavage for 12 weeks); the control group received the solvent at identical amounts and duration. RESULTS: TAA administration induced liver cirrhosis, which was inhibited by curcumin. Liver histopathology, hydroxyproline levels and spleen weights were significantly lower in the rats treated with TAA+curcumin compared with TAA only (P<0.001). Immunohistochemical studies and in situ hybridization demonstrated inhibition of hepatic stellate cell (alpha smooth muscle actin-positive) activation and collagen alpha1 (I) gene expression in the livers of the TAA+curcumin-treated rats. Curcumin reduced oxidative stress as shown by the decreased hepatic nitrotyrosine staining in the curcumin+TAA-treated rats. Curcumin treatment had no effect on pre existing liver cirrhosis. As determined by in vitro studies using the rat HSC-T6 cell line, curcumin had no direct inhibitory effect on collagen alpha1 (I) messenger RNA expression. Further studies in these cells using reverse transcriptase-polymerase chain reaction demonstrated that curcumin had no effect on the expression of PDGF-induced TIMP-1 and TIMP-2, TGFbeta1, TGFbeta2 and MCP-1 but significantly inhibited tumor necrosis factor alpha expression. Curcumin had no effect on hepatic stellate cells proliferation. Zymography showed that curcumin had no effect on matrix metalloproteinase-2 activity. CONCLUSIONS: Curcumin inhibited the development of TAA-induced liver cirrhosis mainly due to its anti-inflammatory activities and not by a direct anti-fibrotic effect. As curcumin ingestion is safe in humans, it may be reasonable to assess in clinical studies the beneficial effect of curcumin in slowing the development of liver cirrhosis.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Curcumina/uso terapêutico , Cirrose Hepática Experimental/prevenção & controle , Actinas/metabolismo , Animais , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Citocinas/metabolismo , Expressão Gênica/efeitos dos fármacos , Hidroxiprolina/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática Experimental/metabolismo , Cirrose Hepática Experimental/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Baço/efeitos dos fármacos , Tioacetamida , Tirosina/análogos & derivados , Tirosina/metabolismo
16.
Isr Med Assoc J ; 8(6): 400-5, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16833169

RESUMO

BACKGROUND: There is a dearth of organs for liver transplantation in Israel. Enhancing our understanding of factors affecting graft survival in this country could help optimize the results of the transplant operation. OBJECTIVES: To report 3 years national experience with orthotopic liver transplantation, and to evaluate patient and perioperative risk factors that could affect 1 year graft survival. METHODS: The study related to all 124 isolated adult liver transplantations performed in Israel between October 1997 and October 2000. Data were abstracted from the medical records. One-year graft survival was described using the Kaplan-Meier survival curve and three multivariate logistic regression models were performed: one with preoperative case-mix factors alone, and the other two with the addition of donor and operative factors respectively. RESULTS: Of the 124 liver transplantations performed, 32 failed (25.8%). The 1 year survival was lower than rates reported from both the United States and Europe but the difference was not significant. Of the preoperative risk factors, recipient age > 60 years, critical condition prior to surgery, high serum bilirubin and serum hemoglobin < or = 10 g/dl were independently associated with graft failure, adjusting for all the other factors that entered the logistic regression equation. Extending the model to include donor and operative factors raised the C-statistic from 0.79 to 0.87. Donor age > or = 40, cold ischemic time > 10 hours and a prolonged operation (> 10 hours) were the additional predictors for graft survival. A MELD score of over 18 was associated with a sixfold increased risk for graft failure (odds ratio = 6.5, P = 0.001). CONCLUSIONS: Graft survival in Israel is slightly lower than that reported from the U.S. and Europe. Adding donor and operative factors to recipient characteristics significantly increased our understanding of 1 year survival of liver grafts.


Assuntos
Sobrevivência de Enxerto , Transplante de Fígado/estatística & dados numéricos , Adulto , Idoso , Grupos Diagnósticos Relacionados , Feminino , Humanos , Israel/epidemiologia , Falência Hepática/cirurgia , Modelos Logísticos , Masculino , Prontuários Médicos , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Análise de Sobrevida
18.
J Gastroenterol Hepatol ; 21(2): 358-66, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16509859

RESUMO

BACKGROUND AND AIM: Increased production of reactive oxygen species and nitric oxide and activation of nuclear factor kappa B are implicated in the pathogenesis of various liver diseases, including fulminant hepatic failure. Curcumin is a naturally occurring anti-oxidant that reduces oxidative stress and inhibits nuclear factor kappa B and nitric oxide formation. The aim of the present study is to assess curcumin's therapeutic potential in acute thioacetamide hepatotoxicity, a rat model of fulminant hepatic failure. METHODS: Fulminant hepatic failure was induced by two intraperitoneal (i.p.) injections of 300 mg/kg thioacetamide (TAA) at 24-h intervals. The experimental groups received a low-dose (200 mg/kg per day, i.p.) or a high-dose (400 mg/kg per day) of curcumin, initiated 48 h prior to the first TAA injection. A fourth group was administered neither TAA nor curcumin and served as a control. RESULTS: The survival rate was higher in both curcumin-treated groups compared to the TAA only treated group. Biochemical parameters of liver injury, blood ammonia and hepatic necroinflammation were lower in the low-dose curcumin group compared to TAA controls, and were further reduced in the high-dose group (P < 0.05 and P < 0.01, respectively). Curcumin treatment also reduced the TAA-induced elevated hepatic levels of thiobarbituric acid-reactive substances (TBARS), and inhibited the nuclear binding of nuclear factor kappa B (NFkappaB) and inducible nitric oxide (iNOS) protein expression. CONCLUSIONS: Curcumin improved survival and minimized oxidative stress, hepatocellular injury and hepatic necroinflammation, NFkappaB binding and iNOS expression in a rat model of FHF. These findings support the role of ROS, NFkappaB and iNOS in mediating liver insult due to TAA, and that of curcumin as a hepato-protectant.


Assuntos
Curcumina/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Falência Hepática Aguda/tratamento farmacológico , Animais , Curcumina/administração & dosagem , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/enzimologia , Masculino , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Tioacetamida/toxicidade , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Resultado do Tratamento
19.
World J Gastroenterol ; 12(2): 240-5, 2006 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-16482624

RESUMO

AIM: To assess the effect of iron reduction after phlebotomy in rats with "normal" hepatic iron concentration (HIC) on the progression of hepatic fibrosis, as a result of bile duct ligation (BDL). METHODS: Rats underwent phlebotomy before or after sham operation or BDL. Animals undergone only BDL or sham operation served as controls. Two weeks after surgery, indices of hepatic damage and fibrosis were evaluated. RESULTS: Phlebotomy lowered HIC. Phlebotomy after BDL was associated with body weight increase, lower hepatic weight, less portal hypertension, less periportal necrosis, less portal inflammation, lower hepatic activity index score and higher albumin levels. On the other hand, phlebotomy before BDL was associated with body weight decrease and hepatic activity index score increase. Phlebotomy after sham operation was not associated with any hepatic or systemic adverse effects. CONCLUSION: Reduction of HIC after induction of liver damage may have beneficial effects in BDL rats. However, iron deficiency could induce impairment of liver function and may make the liver more susceptible to insults like BDL.


Assuntos
Colestase/complicações , Ferro/metabolismo , Cirrose Hepática Experimental/prevenção & controle , Fígado/metabolismo , Flebotomia , Animais , Dinoprostona/biossíntese , Fígado/patologia , Masculino , Peroxidase/metabolismo , Ratos , Ratos Sprague-Dawley
20.
Liver Int ; 25(3): 613-21, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15910499

RESUMO

BACKGROUND/AIM: Allicin, the immunologically active component of garlic, has been found to affect oxidative stress and immune response in several experimental systems. In the present study, we examined the ability of allicin to prevent immune-mediated, concanavalin A (Con A)-induced liver damage in mice. METHODS: Mice were pretreated with allicin for 7 days before their inoculation with Con A (15 mg/kg). The serum levels of liver enzymes and liver histology were examined 24 h after Con A administration. The effect of Con A and allicin on serum levels of tumor necrosis factor-alpha (TNF-alpha) and nuclear factor-kappaB (NF-kappaB) activation in the liver were examined 2 h after Con A administration, in a separate group of rats, and the effect of allicin on Con A-induced expression of inducible nitric oxide synthase (iNOS) was determined by western blot analysis 24 h after Con A injection. RESULTS: The histopathologic damage in the mouse livers, and the Con A-induced increase of aminotransferases and TNF-alpha were markedly inhibited in the mice pretreated with allicin before Con A injection (P < 0.01). NF-kappaB binding activity to the nucleus, which increased 2 h after Con A administration, was attenuated by allicin. The expression of iNOS protein which was induced following Con A administration was significantly attenuated by allicin. In vitro studies showed that allicin inhibited TNF-alpha-mediated T cell adhesion to extracellular matrix components and to endothelial cells. Allicin also inhibited TNF-alpha-mediated intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression on human vascular endothelial cells. CONCLUSIONS: This study demonstrates that immune-mediated liver damage in mice can be prevented by allicin, probably because of its immunomodulatory effects on T cells and adhesion molecules and inhibition of NF-kappaB activation.


Assuntos
Antioxidantes/farmacologia , Alho , Hepatite/imunologia , Hepatite/prevenção & controle , Ácidos Sulfínicos/farmacologia , Alanina Transaminase/metabolismo , Animais , Adesão Celular/efeitos dos fármacos , Adesão Celular/imunologia , Concanavalina A/farmacologia , Dissulfetos , Matriz Extracelular/metabolismo , Hepatite/patologia , Molécula 1 de Adesão Intercelular/metabolismo , Ligantes , Masculino , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/metabolismo , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo II , Estresse Oxidativo/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
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