Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
Dig Dis Sci ; 68(12): 4381-4388, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37864739

RESUMO

BACKGROUND: The Coronavirus disease 2019 (COVID-19) pandemic disrupted patient care and worsened the morbidity and mortality of some chronic diseases. The impact of the COVID-19 pandemic on hospitalizations and outcomes in patients with cirrhosis both before and during different time periods of the pandemic has not been evaluated. AIMS: Describe characteristics of hospitalized patients with cirrhosis and evaluate inpatient mortality and 30-day readmission before and after the start of the COVID-19 pandemic. METHODS: Retrospective single-center cohort study of all hospitalized patients with cirrhosis from 2018 to 2022. Time periods within the COVID-19 pandemic were defined using reference data from the World Health Organization and Centers for Disease Control. Adjusted odds ratios from logistic regression were used to assess differences between periods. RESULTS: 33,926 unique hospitalizations were identified. Most patients were over age 60 years across all time periods of the pandemic. More Hispanic patients were hospitalized during COVID-19 than before COVID-19. Medicare and Medicaid are utilized less frequently during COVID-19 than before COVID-19. After controlling for age and gender, inpatient mortality was significantly higher during all COVID-19 periods except Omicron compared to before COVID-19. The odds of experiencing a 30-day readmission were 1.2 times higher in the pre-vaccination period compared to the pre-COVID-19 period. CONCLUSION: Inpatient mortality among patients with cirrhosis has increased during the COVID-19 pandemic compared to before COVID-19. Although COVID-19 infection may have had a small direct pathologic effect on the natural history of cirrhotic liver disease, it is more likely that other factors are impacting this population.


Assuntos
COVID-19 , Pandemias , Humanos , Idoso , Estados Unidos/epidemiologia , Pessoa de Meia-Idade , COVID-19/epidemiologia , Estudos Retrospectivos , Estudos de Coortes , Medicare , Cirrose Hepática/epidemiologia , Hospitalização
2.
JAMA Netw Open ; 3(9): e2015756, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32880650

RESUMO

Importance: Between 2 and 3.5 million people live with chronic hepatitis C virus (HCV) infection in the US, most of whom (approximately 75%) are not aware of their disease. Despite the availability of effective HCV treatment in the early stages of infection, HCV will result in thousands of deaths in the next decade in the US. Objective: To investigate the cost-effectiveness of universal screening for all US adults aged 18 years or older for HCV in the US and of targeted screening of people who inject drugs. Design, Setting, and Participants: This simulated economic evaluation used cohort analyses in a Markov model to perform a 10 000-participant Monte Carlo microsimulation trail to evaluate the cost-effectiveness of HCV screening programs, and compared screening programs targeting people who inject drugs with universal screening of US adults age 18 years or older. Data were analyzed in December 2019. Exposures: Cost per quality-adjusted life-year (QALY). Main Outcomes and Measures: Cost per QALY gained. Results: In a 10 000 Monte Carlo microsimulation trail that compared a baseline of individuals aged 40 years (men and women) and people who inject drugs in the US, screening and treatment for HCV were estimated to increase total costs by $10 457 per person and increase QALYs by 0.23 (approximately 3 months), providing an incremental cost-effectiveness ratio of $45 465 per QALY. Also, universal screening and treatment for HCV are estimated to increase total costs by $2845 per person and increase QALYs by 0.01, providing an incremental cost-effectiveness ratio of $291 277 per QALY. Conclusions and Relevance: The findings of this study suggest that HCV screening for people who inject drugs may be a cost-effective intervention to combat HCV infection in the US, which could potentially decrease the risk of untreated HCV infection and liver-related mortality.


Assuntos
Custos de Cuidados de Saúde/estatística & dados numéricos , Hepatite C Crônica , Programas de Rastreamento , Abuso de Substâncias por Via Intravenosa , Adulto , Estudos de Coortes , Análise Custo-Benefício , Feminino , Hepacivirus/isolamento & purificação , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/economia , Hepatite C Crônica/epidemiologia , Humanos , Masculino , Cadeias de Markov , Programas de Rastreamento/economia , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Método de Monte Carlo , Serviços Preventivos de Saúde , Anos de Vida Ajustados por Qualidade de Vida , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia , Estados Unidos/epidemiologia
3.
Clin Infect Dis ; 63(6): 776-783, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27325691

RESUMO

BACKGROUND: Sofosbuvir (SOF) is active against all hepatitis C virus (HCV) genotypes, and SOF-based therapies lead to high rates of sustained virologic response (SVR). However, genotype 3 (GT3) HCV remains a challenge with lower SVR rates reported, particularly in patients with cirrhosis. This study reports the effectiveness and safety of SOF-based therapy in patients with GT3 HCV treated in clinical practice. METHODS: Hepatitis C Virus Therapeutic Registry and Research Network is an international, prospective observational study evaluating patients treated in usual clinical practice. Patients with GT3 HCV were analyzed to assess predictors of treatment response and adverse events using descriptive statistics and multivariable logistic regression. RESULTS: Treatment outcomes were available for 197 patients treated with SOF and ribavirin (RBV), with or without peginterferon, including 54% with cirrhosis and 49% who failed prior therapy. Of 178 patients treated with SOF/RBV, 60% achieved SVR at 12 weeks (SVR12), compared with 84% of 19 patients treated with SOF/peginterferon/RBV. For patients treated with SOF/RBV, the SVR12 rate was 58% in treatment-naive patients with cirrhosis, and 42% in those with cirrhosis who failed prior therapy. In noncirrhotic patients, SVR12 rates were 89% in treatment-naive and 88% in treatment-experienced patients. After controlling for age and sex, absence of cirrhosis (odds ratio [OR], 6.4; 95% confidence interval [CI], 2.78-14.74), albumin levels ≥3.2 g/dL (OR, 12.48; 95% CI, 3.86-40.33), and platelet count >10(5) cells/µL (OR, 7.44; 95% CI, 3.51-15.78) were associated with greater odds of SVR12 CONCLUSIONS: SVR rates were acceptable in patients with GT3 HCV without cirrhosis; however, in those with cirrhosis, treatment with SOF/RBV was suboptimal, highlighting the need for new therapies for this population.


Assuntos
Antivirais , Hepatite C Crônica/tratamento farmacológico , Ribavirina , Sofosbuvir , Adolescente , Adulto , Idoso , Antivirais/efeitos adversos , Antivirais/uso terapêutico , Feminino , Genótipo , Hepacivirus , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Ribavirina/efeitos adversos , Ribavirina/uso terapêutico , Sofosbuvir/efeitos adversos , Sofosbuvir/uso terapêutico , Resposta Viral Sustentada , Adulto Jovem
4.
World J Gastroenterol ; 19(41): 7205-8, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24222967

RESUMO

Intramural duodenal hematoma is a rare cause of a proximal gastrointestinal tract obstruction. Presentation of intramural duodenal hematoma most often occurs following blunt abdominal trauma in children, but spontaneous non-traumatic cases have been linked to anticoagulant therapy, pancreatitis, malignancy, vasculitis and endoscopy. We report an unusual case of spontaneous intramural duodenal hematoma presenting as an intestinal obstruction associated with acute pancreatitis in a patient with established von Willebrand disease, type 2B. The patient presented with abrupt onset of abdominal pain, nausea, and vomiting. Computed tomography imaging identified an intramural duodenal mass consistent with blood measuring 4.7 cm × 8.7 cm in the second portion of the duodenum abutting on the head of the pancreas. Serum lipase was 3828 units/L. Patient was managed conservatively with bowel rest, continuous nasogastric decompression, total parenteral nutrition, recombinant factor VIII (humateP) and transfusion. Symptoms resolved over the course of the hospitalization. This case highlights an important complication of an inherited coagulopathy.


Assuntos
Duodenopatias/etiologia , Hematoma/etiologia , Doença de von Willebrand Tipo 2/complicações , Dor Abdominal/etiologia , Doença Aguda , Transfusão de Sangue , Coagulantes/uso terapêutico , Terapia Combinada , Descompressão , Duodenopatias/diagnóstico , Duodenopatias/terapia , Obstrução Duodenal/etiologia , Endoscopia do Sistema Digestório , Endossonografia , Fator VIII/uso terapêutico , Hematoma/diagnóstico , Hematoma/terapia , Humanos , Masculino , Náusea/etiologia , Pancreatite/etiologia , Nutrição Parenteral Total , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Vômito/etiologia , Adulto Jovem , Doença de von Willebrand Tipo 2/diagnóstico , Doença de von Willebrand Tipo 2/terapia
5.
Hepatology ; 50(2): 361-8, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19585621

RESUMO

UNLABELLED: Between March 2000 and July 2001, at least 99 persons acquired a hepatitis C virus genotype 3a (HCV-3a) infection in an oncology clinic. This nosocomial HCV outbreak provided an opportunity to examine the subsequent clinical course in a well-defined cohort. This was a retrospective/prospective observational study of the short-term significant health outcomes of a large, single-source, patient-to-patient HCV-3a outbreak. Outbreak patients or their legal representatives consenting to study were enrolled between September 2002 and December 2007. We measured history and physical examinations, medical records, HCV serology, HCV RNA and genotype, liver enzymes, histology, response to antiviral therapy, and liver-related morbidity and mortality. Sixty-four of the 99 known HCV-3a outbreak patients participated. During a 6-year period, six patients developed life-threatening complications from liver disease, three died, one received a liver transplant, and two were stable after esophageal variceal banding or diuretic therapy of ascites. Thirty-three patients underwent antiviral therapy, with 28 achieving a sustained viral remission. One patient acquired HCV-3a infection sexually from an outbreak patient and was successfully treated. Eleven study patients died of malignancy, including two that had achieved a sustained viral remission after antiviral therapy. CONCLUSION: Our patient cohort had a nosocomial source and an oncologic or hematologic comorbidity. Compared with previous HCV outcome studies, a patient-to-patient HCV outbreak in an oncology clinic exhibited significant morbidity and mortality. Attention is needed to the public health risk of nosocomial HCV transmission, emphasizing infection control, early diagnosis, and therapy.


Assuntos
Infecção Hospitalar/complicações , Surtos de Doenças , Hepatite C/complicações , Fígado/patologia , Neoplasias/complicações , RNA Viral/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Alanina Transaminase/sangue , Antivirais/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/mortalidade , Infecção Hospitalar/virologia , Feminino , Genótipo , Hepatite C/tratamento farmacológico , Hepatite C/genética , Hepatite C/mortalidade , Anticorpos Anti-Hepatite C/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Nebraska/epidemiologia , Estudos Prospectivos , Estudos Retrospectivos , Adulto Jovem
6.
J Natl Med Assoc ; 99(4): 389-92, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17444428

RESUMO

BACKGROUND: Native-American populations are disproportionately burdened by chronic liver disease, and the prevalence of hepatitis C (HCV) in native Americans is unknown. PURPOSE: To determine the prevalence of hepatitis C in a local native-American population via a prospective screening study. PROCEDURES: Two-hundred-forty-three native Americans (161 females/82 males) using an urban clinic and representing > 30 tribes from across the United States were screened. Mean age was 41 +/- 1 years. Hepatitis-C screening was by anti-HCV with confirmation by HCV RNA. A questionnaire assessed potential risk factors for HCV. FINDINGS: Anti-HCV antibodies were found in 11.5% (95% CI: 7.5-15.5%). HCV RNA was present by polymerase chain reaction (PCR) in 8.6% (95% CI: 5.1-12.1%) and was more common in males [13.4% (95% CI: 6.0-20.8%)] than females [6.2% (95% CI: 2.5-9.9%)]. The most common potential risk factors for chronic HCV infection were intravenous (IV) drug or cocaine use (p < 0.0001), tattoos > 5 years old (p < 0.0001) and having a sexual partner with HCV (p = 0.0063). CONCLUSION: HCV prevalence is higher in an urban native-American clinic population than reported in the general U.S. population. Use of IV drugs is the most prevalent risk factor, but tattoos and sexual transmission may also be important.


Assuntos
Hepatite C Crônica/etnologia , Hospitais Urbanos/estatística & dados numéricos , Indígenas Norte-Americanos/estatística & dados numéricos , Programas de Rastreamento , Saúde da População Urbana/estatística & dados numéricos , Adulto , Feminino , Anticorpos Anti-Hepatite C , Hepatite C Crônica/etiologia , Hepatite C Crônica/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Nebraska/epidemiologia , Prevalência , Estudos Prospectivos , Fatores de Risco , Abuso de Substâncias por Via Intravenosa/complicações , Tatuagem , Estados Unidos/epidemiologia , United States Indian Health Service
7.
J Hepatol ; 46(6): 1119-25, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17336420

RESUMO

BACKGROUND/AIMS: Protein-L-isoaspartyl methyltransferase (PIMT) is a methyltransferase that plays a crucial role in the repair of damaged proteins. In this study, we investigated whether ethanol exposure causes an accumulation of modified proteins bearing atypical isoaspartyl residues that may be related to impaired PIMT activity. We further sought to determine whether betaine administration could prevent the accumulation of these types of damaged proteins. METHODS: Livers of male Wistar rats, fed the Lieber DeCarli control, ethanol or 1% betaine-supplemented diets for 4 weeks, were processed for PIMT-related analyses. RESULTS: We observed a significant increase in the accumulation of modified proteins bearing isoaspartyl residues, i.e. the substrates for PIMT, in homogenate samples and various subcellular fractions of livers from ethanol-fed rats. Betaine supplementation prevented this accumulation of damaged proteins. In contrast, ethanol exposure induced no changes in the PIMT enzyme activity levels as compared to controls. The accumulation of damaged proteins negatively correlated with hepatic S-adenosylmethionine (SAM) to S-adenosylhomocysteine (SAH) ratios. CONCLUSIONS: Ethanol consumption results in the accumulation of modified proteins bearing atypical isoaspartyl residues via impaired in vivo PIMT activity. Betaine administration prevents the ethanol-induced accumulation of isoaspartyl-containing proteins by restoring the PIMT-catalyzed protein repair reaction through normalizing the hepatocellular SAM:SAH ratios.


Assuntos
Álcoois/toxicidade , Betaína/farmacologia , Fígado/efeitos dos fármacos , Proteína D-Aspartato-L-Isoaspartato Metiltransferase/fisiologia , Animais , Catálise , Dieta , Etanol/toxicidade , Masculino , Microssomos/metabolismo , Proteína D-Aspartato-L-Isoaspartato Metiltransferase/metabolismo , Ratos , Ratos Wistar , S-Adenosil-Homocisteína/química , S-Adenosilmetionina/química , Frações Subcelulares
8.
J Hepatol ; 46(2): 314-21, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17156888

RESUMO

BACKGROUND/AIMS: Previous studies in our laboratory implicated ethanol-induced decreases in hepatocellular S-adenosylmethionine to S-adenosylhomocysteine (SAM:SAH) ratios in lowering the activity of phosphatidylethanolamine methyltransferase (PEMT), which is associated with the generation of steatosis. Further in vitro studies showed that betaine supplementation could correct these alterations in the ratio as well as attenuate alcoholic steatosis. Therefore, we sought to determine whether the protective effect of betaine is via its effect on PEMT activity. METHODS: Male Wistar rats were fed the Lieber DeCarli control or ethanol diet with or without 1% betaine supplementation for 4 weeks. RESULTS: We observed that ethanol feeding resulted in decreased phosphatidylcholine (PC) production by a PEMT-catalyzed reaction. Betaine supplementation corrected the ethanol-induced decrease in hepatic SAM:SAH ratios and by normalizing PC production via the PEMT-mediated pathway, significantly reduced fatty infiltration associated with ethanol consumption. This restoration of hepatocellular SAM:SAH ratio by betaine supplementation was associated with increases in the activity, enzyme mass and gene expression of the enzyme, betaine homocysteine methyltransferase (BHMT), that remethylates homocysteine. CONCLUSIONS: Betaine, by virtue of promoting an alternate remethylation pathway, restores SAM:SAH ratios that, in turn, correct the defective cellular methylation reaction catalyzed by PEMT resulting in protection against the generation of alcoholic steatosis.


Assuntos
Betaína/administração & dosagem , Fígado Gorduroso Alcoólico/prevenção & controle , Lipotrópicos/administração & dosagem , Fosfatidilcolinas/metabolismo , Fosfatidiletanolamina N-Metiltransferase/metabolismo , Animais , Dieta , Etanol/toxicidade , Fígado Gorduroso Alcoólico/enzimologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Masculino , Fosfatidiletanolamina N-Metiltransferase/análise , Ratos , Ratos Wistar , S-Adenosil-Homocisteína/análise , S-Adenosilmetionina/análise , Triglicerídeos/análise
9.
Annu Rev Med ; 57: 155-66, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16409142

RESUMO

Hepatitis B is a global health problem. Patients with chronic hepatitis B (CHB) carry a significant risk to eventually develop cirrhotic liver disease. Recent therapeutic advances against CHB offer excellent potential for long-term suppression of hepatitis B virus (HBV) replication during antiviral therapy, and occasionally a durable remission off medication. Selection of appropriate patients for antiviral therapy depends on identification of HBV replication and an elevated alanine aminotransferase level or histologic liver injury. Pegylated interferon alpha offers potent immunomodulatory and antiviral activity with the potential for durability, but also with adverse effects and significant cost. The nucleoside or nucleotide analogs, lamivudine, adefovir, and entecavir, suppress HBV replication and are extremely well-tolerated, but long-term or even lifelong therapy is required. Most experience has been gained with lamivudine, but viral resistance occurs frequently. Newer analogs appear to be relatively free of this problem. Approaches using a combination of agents have promise, but have yet to be proven superior to individual drugs alone.


Assuntos
Antivirais/uso terapêutico , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Nucleosídeos/uso terapêutico , Hepatite B Crônica/diagnóstico , Humanos
10.
Biochem Pharmacol ; 70(12): 1883-90, 2005 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-16253211

RESUMO

Previous studies from our laboratory have shown that ethanol consumption results in an increase in hepatocellular S-adenosylhomocysteine levels. Because S-adenosylhomocysteine is a potent inhibitor of methylation reactions, we propose that increased intracellular S-adenosylhomocysteine levels could be a major contributor to ethanol-induced pathologies. To test this hypothesis, hepatocytes isolated from rat livers were grown on collagen-coated plates in Williams' medium E containing 5% FCS and exposed to varying concentrations of adenosine in order to increase intracellular S-adenosylhomocysteine levels. We observed increases in caspase-3 activity following exposure to adenosine. This increase in caspase activity correlated with increases in intracellular S-adenosylhomocysteine levels and DNA hypoploidy. The adenosine-induced changes could be significantly attenuated by betaine administration. The mechanism of betaine action appeared to be via the methylation reaction catalyzed by betaine-homocysteine-methyltransferase. To conclude, our results indicate that the elevation of S-adenosylhomocysteine levels in the liver by ethanol is a major factor in altering methylation reactions and in increasing apoptosis in the liver. We conclude that ethanol-induced alteration in methionine metabolic pathways may play a crucial role in the pathologies associated with alcoholic liver injury and that betaine administration may have beneficial therapeutic effects.


Assuntos
Apoptose/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , S-Adenosil-Homocisteína/metabolismo , Adenosina/farmacologia , Animais , Betaína/farmacologia , Caspase 3 , Caspases/metabolismo , Células Cultivadas , Citoproteção , Fragmentação do DNA , Etanol/toxicidade , Hepatócitos/metabolismo , Hepatócitos/patologia , Masculino , Metilação , Ratos , Ratos Wistar
11.
J Nutr ; 135(3): 519-24, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15735087

RESUMO

Previous studies showed that chronic ethanol administration alters methionine metabolism in the liver, resulting in increased intracellular S-adenosylhomocysteine (SAH) levels and increased homocysteine release into the plasma. We showed further that these changes appear to be reversed by betaine administration. This study compared the effects of betaine and S-adenosylmethionine (SAM), another methylating agent, on ethanol-induced changes of methionine metabolism and hepatic steatosis. Wistar rats were fed ethanol or control Lieber-Decarli liquid diet for 4 wk and metabolites of the methionine cycle were measured in isolated hepatocytes. Hepatocytes from ethanol-fed rats had a 50% lower intracellular SAM:SAH ratio and almost 2-fold greater homocysteine release into the media compared with controls. Supplementation of betaine or SAM in the incubation media increased this ratio in hepatocytes from both control and ethanol-fed rats and attenuated the ethanol-induced increased hepatocellular triglyceride levels by approximately 20%. On the other hand, only betaine prevented the increase in generation of homocysteine in the incubation media under basal and methionine-loaded conditions. SAM can correct only the ratio and the methylation defects and may in fact be detrimental after prolonged use because of its propensity to increase homocysteine release. Both SAM and betaine are effective in increasing the SAM:SAH ratio in hepatocytes and in attenuating hepatic steatosis; however, only betaine can effectively methylate homocysteine and prevent increased homocysteine release by the liver.


Assuntos
Betaína/farmacologia , Etanol/farmacologia , Fígado Gorduroso/metabolismo , Hepatócitos/metabolismo , Metionina/metabolismo , S-Adenosilmetionina/farmacologia , Animais , Modelos Animais de Doenças , Hepatócitos/efeitos dos fármacos , Masculino , Metiltransferases/metabolismo , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Fosfatidiletanolamina N-Metiltransferase , Ratos , Ratos Wistar
12.
Semin Liver Dis ; 24(3): 233-47, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15349802

RESUMO

Alcoholic liver disease (ALD) presents considerable challenges to clinicians. Screening for alcohol abuse and alcoholism should be routine and repeated annually with close attention to signs and symptoms of liver disease. In patients with evidence of liver dysfunction or injury, consideration should be given to performance of liver biopsy for diagnosis and prognosis and prior to initiation of medication with the potential for significant side effects. Therapy depends on the spectrum of pathological liver injury: alcoholic fatty liver, alcoholic hepatitis, and cirrhosis. Abstention is the foundation of therapy for an alcohol problem. Alcoholic fatty liver should improve with abstention, but the similarity to the pathogenesis of nonalcoholic fatty liver and potential for progressive injury merits consideration of lipotropic agents. The continuing mortality, poor acceptance of corticosteroids, and identification of tumor necrosis factor-alpha (TNF-alpha) as an integral component has led to studies of pentoxifylline and, recently, anti-TNF antibody to neutralize cytokines in the therapy of severe alcoholic hepatitis. Antioxidant therapy of alcoholic cirrhosis has significant promise but will require large clinical trials.


Assuntos
Hepatopatias Alcoólicas/diagnóstico , Hepatopatias Alcoólicas/terapia , Corticosteroides/uso terapêutico , Consumo de Bebidas Alcoólicas , Anticorpos Monoclonais/uso terapêutico , Antioxidantes/uso terapêutico , Biópsia , Diagnóstico Diferencial , Humanos , Fígado/patologia , Prognóstico , Fator de Necrose Tumoral alfa/antagonistas & inibidores
14.
J Nutr ; 133(9): 2845-8, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12949375

RESUMO

Previous studies showed that chronic ethanol administration inhibits methionine synthase activity, resulting in impaired homocysteine remethylation to form methionine. This defect in homocysteine remethylation was shown to increase plasma homocysteine and to interfere with the production of hepatic S-adenosylmethionine (SAM) in ethanol-fed rats. These changes were shown to be reversed by the administration of betaine, an alternative methylating agent. This study was undertaken to determine additional effects of ethanol on methionine metabolism and their functional consequences. The influences of methionine loading and betaine supplementation were also evaluated. Adult Wistar rats were fed ethanol or a control Lieber-DeCarli liquid diet for 4 wk, and metabolites of the methionine cycle were measured in vitro in isolated hepatocytes under basal and methionine-supplemented conditions. S-Adenosylhomocysteine (SAH) concentrations were elevated in hepatocytes isolated from ethanol-fed rats compared with controls and in hepatocytes from both groups when supplemented with methionine. The addition of betaine to the methionine-supplemented incubation media reduced the elevated SAH levels. The decrease in the intracellular SAH:SAM ratio due to ethanol consumption inhibited the activity of the liver-specific SAM-dependent methyltransferase, phosphatidylethanolamine methyltransferase. Our data indicate that betaine, by remethylating homocysteine and removing SAH, overcomes the detrimental effects of ethanol consumption on methionine metabolism and may be effective in correcting methylation defects and treating liver diseases.


Assuntos
Betaína/farmacologia , Etanol/administração & dosagem , Hepatócitos/metabolismo , S-Adenosil-Homocisteína/antagonistas & inibidores , Administração Oral , Animais , Masculino , Metionina/farmacologia , Metiltransferases/metabolismo , Fosfatidiletanolamina N-Metiltransferase , Ratos , Ratos Wistar , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo
15.
Best Pract Res Clin Gastroenterol ; 17(3): 357-67, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12763501

RESUMO

Cholestasis of sepsis is a form of hepatocellular cholestasis that occurs as a result of sepsis. Usually, prior to the development of cholestasis, the manifestations of sepsis dominate the clinical picture. The occurrence of cholestasis is without direct bacterial involvement of the biliary system and appears to be mediated systemically by pro-inflammatory cytokines. These cytokines are released in response to the vigorous inflammatory reaction mediated by endotoxinaemia and bacterial wall lipopolysaccharides. The principal cytokines involved are the pro-inflammatory tumour necrosis factor-alpha (TNF-alpha), interleukin (IL) 1-beta and IL-6. Interplay between these cytokines and a series of hepatocyte membrane transporters appears to result in the cholestasis. Management principles focus upon the control of sepsis.


Assuntos
Colestase Intra-Hepática/etiologia , Colestase Intra-Hepática/fisiopatologia , Estado Terminal , Sepse/complicações , Sepse/fisiopatologia , Colestase Intra-Hepática/terapia , Humanos , Padrões de Prática Médica , Sepse/terapia
16.
Best Pract Res Clin Gastroenterol ; 17(2): 307-22, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12676121

RESUMO

This chapter describes the gene mutations, phenotypes, diagnosis and therapy of the common metabolic liver diseases in young adulthood: haemochromatosis, Wilson disease, alpha(1)-anti-trypsin deficiency and cystic fibrosis. The remarkable variability of the phenotypical expression of the mutated genotypes makes screening recommendations and the establishment of prognosis for these liver disorders in young adults problematical. The diagnosis and therapy of the young adult with metabolic liver disease is discussed, with an emphasis on maintaining quality-of-life and balancing the importance of early intervention with the stigmatization of the diagnosis of potentially life-threatening liver disease. There is a critical need for the development of biochemical markers that would predict the risk of expression of clinical phenotypes and prognosis.


Assuntos
Fibrose Cística/diagnóstico , Fibrose Cística/genética , Hemocromatose/diagnóstico , Hemocromatose/genética , Degeneração Hepatolenticular/diagnóstico , Degeneração Hepatolenticular/genética , Mutação/genética , Deficiência de alfa 1-Antitripsina/diagnóstico , Deficiência de alfa 1-Antitripsina/genética , Adulto , Fatores Etários , Fibrose Cística/terapia , Hemocromatose/terapia , Degeneração Hepatolenticular/terapia , Humanos , Fenótipo , Deficiência de alfa 1-Antitripsina/terapia
18.
Arch Biochem Biophys ; 400(2): 215-22, 2002 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-12054432

RESUMO

System A, the Na(+)-dependent amino acid transport activity, is encoded by the ATA2 gene and up-regulated following partial hepatectomy (PH), and its competitive inhibition interferes with liver regeneration. Rabbit polyclonal antibody was raised against a portion of the ATA2 gene product followed by immunodetection of ATA2 in isolated liver plasma membrane and lysate. The level of ATA2 increased in the plasma membrane following PH, while the relatively high quantity of ATA2 found in liver lysate remained constant. We also have shown that Northern analysis of steady-state ATA2 mRNA revealed no significant change following PH. These data show that ATA2-mediated transport is not regulated by the steady-state level of ATA2 mRNA but is regulated by the amount of ATA2 and redistribution to the plasma membrane. We hypothesize that ATA2 activity is regulated by recruitment of ATA2 protein from an intracellular compartment. In addition, the pattern of expression of System A activity in oocytes, transport kinetics, and sensitivity to chemical modification indicate the presence of a second System A isoform in liver that differs substantially from ATA2.


Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Aminoácidos/metabolismo , Membrana Celular/metabolismo , Regeneração Hepática/fisiologia , beta-Alanina/análogos & derivados , Sistema A de Transporte de Aminoácidos/genética , Aminoácidos/farmacocinética , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Compartimento Celular/fisiologia , Membrana Celular/química , Etilmaleimida/farmacologia , Hepatectomia , Líquido Intracelular/metabolismo , Masculino , Oócitos/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Transporte Proteico/fisiologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Sódio/metabolismo , Reagentes de Sulfidrila/farmacologia , Xenopus laevis , beta-Alanina/metabolismo
19.
Biochem Pharmacol ; 63(4): 697-706, 2002 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11992638

RESUMO

The increased deposition of extracellular matrix by hepatic stellate cells following liver injury, in a process known as activation, is considered a key mechanism for increased collagen content of liver during the development of liver fibrosis. We report that N-(methylamino)isobutyric acid (MeAIB), a specific inhibitor of System A-mediated amino acid uptake, reduces the accumulation of collagen in CFSC-2G hepatic stellate cell cultures and in a rat model of liver injury and fibrosis. Rat CFSC-2G cells were cultured in 0-5mM MeAIB, and the accumulation and synthesis of collagen were measured by binding to Sirius red F3B and pulse-labeling with [3H]-proline, respectively. The effect of MeAIB on collagen accumulation in vivo was evaluated utilizing a rat model of hepatic fibrosis. MeAIB inhibited collagen accumulation in CFSC-2G cultures in a concentration-dependent manner with 5mM MeAIB reducing collagen 44.6+/-1.2% compared with the control. In CFSC-2G cultures, MeAIB selectively inhibited the incorporation of proline into cellular macromolecules by 43+/-4%, while the synthesis of proteins containing leucine was not affected. In vivo, oral administration of 160mg MeAIB/kg body weight per day to rats significantly reduced the hepatic collagen accumulation in response to 1 week of CCl(4)-induced liver injury. MeAIB reduces the accumulation of collagen in CFSC-2G hepatic stellate cell cultures and in a CCl(4)-induced rat model of liver injury and fibrosis.


Assuntos
Ácidos Aminoisobutíricos/farmacologia , Colágeno Tipo I/metabolismo , Hepatócitos/efeitos dos fármacos , Actinas/metabolismo , Aminoácidos/farmacologia , Animais , Células Cultivadas , Colágeno Tipo I/genética , Expressão Gênica/efeitos dos fármacos , Hepatócitos/metabolismo , Leucina/metabolismo , Cirrose Hepática/metabolismo , Prolina/metabolismo , Ratos , Síndrome do Desconforto Respiratório/enzimologia , Síndrome do Desconforto Respiratório/metabolismo
20.
Biochem Biophys Res Commun ; 290(5): 1513-20, 2002 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-11820793

RESUMO

Phosphoenolpyruvate carboxykinase (PEPCK) mRNA is elevated in H4IIEC3 rat hepatoma cells cultured at high density, suggesting that PEPCK expression and growth arrest may be coordinately regulated. Induction of growth arrest either by contact inhibition (high culture density) or by serum deprivation correlated with significant increases in PEPCK protein and its mRNA. The observation that PEPCK mRNA was induced by contact inhibition in the presence of serum indicates that the effect of high density is independent of insulin or any other serum component. The magnitudes of the changes in PEPCK expression during growth arrest were greatly enhanced in KRC-7 cells, an H4IIEC3 subclone that is much more sensitive to growth arrest than its parental cell line. Restimulation of proliferation in growth-arrested KRC-7 cells, either by addition of serum or insulin to serum-deprived cells or by replating contact-inhibited cells at low density, caused a rapid decrease in PEPCK expression. However, PEPCK mRNA is not always reduced in proliferating cells since treatment of serum-starved cells with epidermal growth factor stimulated entry into the cell cycle but did not affect PEPCK mRNA levels. Finally, dexamethasone induction of PEPCK mRNA was blunted in cells cultured at high density but was unaffected by the presence or absence of serum. Collectively, these data suggest the possibility of cross-talk between the control of PEPCK expression and growth arrest in KRC-7 cells.


Assuntos
Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/patologia , Fosfoenolpiruvato Carboxiquinase (GTP)/biossíntese , Animais , Carcinoma Hepatocelular/genética , Adesão Celular/genética , Comunicação Celular/genética , Contagem de Células , Divisão Celular/genética , Meios de Cultura Livres de Soro , Indução Enzimática/genética , Regulação Neoplásica da Expressão Gênica , Interfase/genética , Neoplasias Hepáticas/genética , Fosfoenolpiruvato Carboxiquinase (GTP)/genética , RNA Mensageiro/biossíntese , Ratos , Fase S/genética , Células Tumorais Cultivadas , Regulação para Cima/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA