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1.
J Viral Hepat ; 24(1): 22-27, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27730717

RESUMEN

Early data regarding the "real-world" experience with novel therapies for hepatitis C (HCV) are encouraging. Data are still limited, however, regarding real-world rates of sustained virologic response (SVR) for ledipasvir-sofosbuvir (LDV-SOF), particularly for patients with prior treatment failure. We performed a retrospective cohort study of 1597 patients with chronic genotype 1 HCV who were treated using 12 weeks of the following regimens LDV-SOF±ribavirin (RBV) (n=1521 without RBV, n=76 with RBV). The primary outcome was SVR-determined at 12 weeks in an intention-to-treat design. Prescription according to Food and Drug Administration (FDA) approved labelling (adding RBV for patients with cirrhosis and treatment failure) was assessed in multivariate models. The study population was aged 60 years on average (range 19-89), 60% male, 50% Caucasian, 43% cared for at an academic centre and 30% cirrhotic. Overall, LDV-SOF resulted in a 94% SVR rate. Only 44 (2.9%) patients relapsed. LDV-SOF+RBV yielded SVR in 97% with 0 viral relapses. While cirrhosis and thrombocytopenia were associated with lower odds of SVR, in a multivariable regression model, only treatment at an academic centre and prescriptions contrary to FDA labelling were significantly associated with lower SVR-odds ratios, 0.56 95% CI (0.35-0.87) and 0.29 95% CI(0.12-0.68), respectively. The real-world experience with LDV-SOF mirrors the SVR rates observed in clinical trials. Efforts to promote prescription within FDA recommendations are warranted.


Asunto(s)
Antivirales/uso terapéutico , Bencimidazoles/uso terapéutico , Fluorenos/uso terapéutico , Genotipo , Hepacivirus/clasificación , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Uridina Monofosfato/análogos & derivados , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Hepacivirus/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Ribavirina/uso terapéutico , Sofosbuvir , Respuesta Virológica Sostenida , Resultado del Tratamiento , Uridina Monofosfato/uso terapéutico , Adulto Joven
2.
J Viral Hepat ; 23(6): 447-54, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26840452

RESUMEN

Despite the clinical success in the real-world of all oral hepatitis C virus (HCV) therapy with response rates approaching that seen in the clinical trials, access has been limited by many payers with discussion of prioritization of treatment based upon AASLD guidelines. We evaluated patients in the TRIO network who were prescribed sofosbuvir (SOF)-based regimens to determine reasons for not starting treatment. Trio Health is a disease management company that works in partnership with academic medical centres, community physicians and specialty pharmacies in the United States to optimize care for HCV. Data for 3841 patients prescribed a sofosbuvir-containing regimen between December 2013 and September 2014 were obtained through this programme. Of the entire group, 315 (8%) patients did not start the prescribed sofosbuvir-containing therapy. A total of 141 (45%) of the nonstart patients had a commercial plan as their primary insurance, 137 (44%) were primarily covered by Medicaid, 17 (5%) were primarily covered by Medicare, and 20 (6%) were either without coverage or coverage was not specified. Reasons for nonstarts were varied and overlapping. Only 15 patients (5% of nonstarts) did not start because they were unreachable or failed to complete required testing. Another 39 patients who did not start (12%) were following their physicians' direction to either wait for new treatment options or to hold treatment for an unspecified reason. Insurance-related processes and financial reasons accounted for 254 (81%) of the 315 nonstarts. The remaining 7 (2%) patients did not have a specified reason for not starting treatment. Nonstart rates were highest in the Medicaid-covered population at 35%. Medicare and Commercial nonstart rates were 2% and 6%, respectively. In a matched comparison, patients with commercial coverage were 6.5 times as likely to start SOF-based therapy compared to patients with Medicaid. Despite high SVR rates of SOF-based regimens in clinical practice, there are still barriers to access to care. In fact, almost half of the nonstart patients had advanced fibrosis scores (F3 or F4) and should have been prioritized to start treatment. As better treatment for HCV with high efficacy and low side effect rates become available, the disparity in access to treatment, as evidenced by the high nonstart rate in the Medicaid-covered group, must be resolved.


Asunto(s)
Antivirales/administración & dosificación , Accesibilidad a los Servicios de Salud , Hepatitis C Crónica/tratamiento farmacológico , Sofosbuvir/administración & dosificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Estados Unidos , Adulto Joven
3.
Nat Genet ; 13(4): 399-408, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8696333

RESUMEN

Hereditary haemochromatosis (HH), which affects some 1 in 400 and has an estimated carrier frequency of 1 in 10 individuals of Northern European descent, results in multi-organ dysfunction caused by increased iron deposition, and is treatable if detected early. Using linkage-disequilibrium and full haplotype analysis, we have identified a 250-kilobase region more than 3 megabases telomeric of the major histocompatibility complex (MHC) that is identical-by-descent in 85% of patient chromosomes. Within this region, we have identified a gene related to the MHC class I family, termed HLA-H, containing two missense alterations. One of these is predicted to inactivate this class of proteins and was found homozygous in 83% of 178 patients. A role of this gene in haemochromatosis is supported by the frequency and nature of the major mutation and prior studies implicating MHC class I-like proteins in iron metabolism.


Asunto(s)
Antígenos HLA/genética , Hemocromatosis/genética , Antígenos de Histocompatibilidad Clase I/genética , Proteínas de la Membrana , Alelos , Secuencia de Aminoácidos , Secuencia de Bases , Evolución Biológica , Cromosomas Artificiales de Levadura , Cromosomas Humanos Par 6 , Clonación Molecular/métodos , Cisteína , Cartilla de ADN/química , Expresión Génica , Genes MHC Clase I , Marcadores Genéticos , Haplotipos , Proteína de la Hemocromatosis , Humanos , Desequilibrio de Ligamiento , Complejo Mayor de Histocompatibilidad , Datos de Secuencia Molecular , ARN Mensajero/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido
4.
J Clin Invest ; 94(1): 9-15, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8040296

RESUMEN

Hepatic iron overload causes lipocyte activation with resultant fibrogenesis. This study examines whether rat lipocytes express ferritin receptors, which could be involved in paracellular iron movement and in cellular regulation. Lipocytes from normal rat liver were cultured on plastic and incubated with 125I-labeled rat liver ferritin (RLF) +/- a 100-fold excess of either unlabeled RLF or human heart ferritin, human liver ferritin, human recombinant H-ferritin, a mutant human recombinant L-ferritin, or a variety of nonspecific proteins. Specific binding sites for ferritin were demonstrated by displacement of 125I-RLF by RLF (64.5 +/- 4.3%) and by other ferritins (55-60%), but not by recombinant L-ferritin. Scatchard analysis demonstrated a single class of binding sites with a Kd of 5.1 +/- 2.9 x 10(-10) M, maximum binding capacity of 4.7 +/- 1.3 x 10(-12) M, and 5,000-10,000 receptor sites/cell. Ferritin receptor expression was observed only in activated lipocytes. Internalization of RLF was observed within 15 min using FITC-RLF and confocal microscopy. This study demonstrates that (a) activated lipocytes express a specific high affinity ferritin receptor; (b) the binding appears to be dependent on the H-ferritin subunit; and (c) lipocytes internalize ferritin. Expression of ferritin receptors in activated lipocytes suggests that the receptor may either be involved in the activation cascade or may be a marker of activation.


Asunto(s)
Adipocitos/química , Ferritinas/metabolismo , Proteínas de Unión a Hierro , Hígado/química , Receptores de Superficie Celular/análisis , Actinas/análisis , Animales , Unión Competitiva , Hígado/citología , Masculino , Ratas , Ratas Sprague-Dawley
5.
J Clin Invest ; 71(3): 429-39, 1983 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-6826715

RESUMEN

Peroxidative decomposition of cellular membrane lipids is a postulated mechanism of hepatocellular injury in parenchymal iron overload. In the present study, we looked for direct evidence of lipid peroxidation in vivo (as measured by lipid-conjugated diene formation in hepatic organelle membranes) from rats with experimental chronic iron overload. Both parenteral ferric nitrilotriacetate (FeNTA) administration and dietary supplementation with carbonyl iron were used to produce chronic iron overload. Biochemical and histologic evaluation of liver tissue confirmed moderate increases in hepatic storage iron. FeNTA administration produced excessive iron deposition throughout the hepatic lobule in both hepatocytes and Kupffer cells, whereas dietary carbonyl iron supplementation produced greater hepatic iron overload in a periportal distribution with iron deposition predominantly in hepatocytes. Evidence for mitochondrial lipid peroxidation in vivo was demonstrated at all three mean hepatic iron concentrations studied (1,197, 3,231, and 4,216 micrograms Fe/g) in both models of experimental chronic iron overload. In contrast, increased conjugated diene formation was detected in microsomal lipids only at the higher liver iron concentration (4,161 micrograms Fe/g) achieved by dietary carbonyl iron supplementation. When iron as either FeNTA or ferritin was added in vitro to normal liver homogenates before lipid extraction, no conjugated diene formation was observed. We conclude that the presence of conjugated dienes in the subcellular fractions of rat liver provide direct evidence of iron-induced hepatic mitochondrial and microsomal lipid peroxidation in vivo in two models of experimental chronic iron overload.


Asunto(s)
Hierro/envenenamiento , Peróxidos Lipídicos/metabolismo , Hígado/metabolismo , Lípidos de la Membrana/metabolismo , Animales , Dieta , Técnicas In Vitro , Hierro/metabolismo , Hígado/ultraestructura , Masculino , Microscopía Electrónica , Microsomas Hepáticos/metabolismo , Mitocondrias Hepáticas/metabolismo , Oxidación-Reducción/efectos de los fármacos , Ratas , Ratas Endogámicas
6.
Arch Intern Med ; 141(2): 223-6, 1981 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7458518

RESUMEN

Two patients became severely pancytopenic while receiving azathioprine in low dosages for treatment of connective-tissue diseases. While mild hematologic complications are common with this drug, we believe that the degree of bone marrow suppression exhibited in these two patients is unusual, especially at the dosages (0.75 and 1.25 mg/kg/day) of azathioprine being used.


Asunto(s)
Azatioprina/efectos adversos , Enfermedades del Tejido Conjuntivo/tratamiento farmacológico , Pancitopenia/inducido químicamente , Adulto , Artritis Juvenil/tratamiento farmacológico , Azatioprina/uso terapéutico , Recuento de Células Sanguíneas , Médula Ósea/diagnóstico por imagen , Esquema de Medicación , Femenino , Humanos , Lupus Eritematoso Sistémico/tratamiento farmacológico , Persona de Mediana Edad , Pancitopenia/patología , Prednisona/uso terapéutico , Radiografía
7.
Arch Intern Med ; 140(9): 1206-11, 1980 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6996630

RESUMEN

We present here results of studies on four patients (three men, one woman) who had had cadaver renal transplants and in whom renal artery stenosis and hypertension developed. Erythropoietin-dependent erythrocytosis developed in association with these changes in the three men. All patients had stable renal function and the hypertension was well controlled. Absolute erythrocytosis thought to be secondary to local renal hypoxia due to decreased renal blood flow developed in two of the men. Erythrocytosis developed in the other man but his RBC mass was at the upper limit of normal. In these patients, we suspect that the erythropoietin-dependent erythrocytosis is secondary to intrarenal hypoxia due to renal artery stenosis. Erythrocytosis or elevated erythropoietin levels failed to develop in the woman despite severe renal artery stenosis. Possible reasons for this discrepancy are discussed.


Asunto(s)
Trasplante de Riñón , Policitemia/sangre , Complicaciones Posoperatorias/sangre , Obstrucción de la Arteria Renal/sangre , Adulto , Cadáver , Creatinina/sangre , Eritropoyetina/sangre , Femenino , Hematócrito , Humanos , Masculino , Renina/sangre , Trasplante Homólogo
8.
Am J Med ; 107(6B): 67S-70S, 1999 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-10653461

RESUMEN

In the great majority of patients, hepatitis C virus (HCV) infection is not self-limiting. Approximately 70% to 85% of patients exposed to HCV will go on to develop chronic hepatitis. Among those who undergo treatment with interferon alpha, only 15% to 20% can be expected to respond to a 12- to 18-month course of therapy. With the addition of ribavirin to interferon monotherapy, the likelihood of sustained response (defined as normal alanine aminotransferase levels and negative HCV RNA persisting 6 months after the end of therapy) increases to approximately 40%. The fact remains, however, that there is still a substantial proportion of patients who will fail to respond to treatment. Without viral eradication, cirrhosis and hepatocellular carcinoma persist as long-term risks. Several options are available for the treatment of patients who fail to respond to interferon monotherapy. These include interferon dose escalation, whether by administering higher doses or administering them more frequently; changing to a different form of interferon; retreatment with a combination of interferon and ribavirin; adjunctive therapies, of which the best studied is phlebotomy to decrease hepatic iron stores; use of long-term, low-dose "maintenance"-type therapy; and watchful waiting with frequent follow-up. In the absence of long-term, large-scale clinical trials to support these modalities, physicians must exercise their best clinical judgment and individualize treatment to suit the patient's condition, needs, and preferences.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C Crónica/terapia , Interferón-alfa/uso terapéutico , Antivirales/administración & dosificación , Terapia Combinada , Quimioterapia Combinada , Hepatitis C Crónica/tratamiento farmacológico , Humanos , Interferón-alfa/administración & dosificación , Flebotomía , Ribavirina/administración & dosificación , Insuficiencia del Tratamiento
9.
Transplantation ; 69(10): 2214-8, 2000 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-10852630

RESUMEN

Spontaneous rupture of the liver has been described in association with many benign and malignant conditions. We report, to our knowledge, the first case of spontaneous rupture of the liver upon revascularization, requiring total hepatectomy and portocaval shunt, followed by successful retransplantation. Routine pathological examination of the explanted liver failed to reveal the etiology of the rupture. However, electron microscopy demonstrated abnormal collagen in the hepatic arterial wall compatible with a collagen disorder such as Ehlers-Danlos type IV disease. We conclude that the donor liver had a previously undiagnosed collagen disorder. Review of the literature does not preclude the use of livers from donors with a history of connective tissue disorders. Based on our experience one should exercise caution when using livers from such donors. With a history of connective tissue disorder in an immediate family member, further tests should be performed in the donor to rule out a subclinical connective tissue disorder. In addition, a review of all patients reported thus far to have undergone total hepatectomy and portocaval shunt, followed by liver transplantation as a two-stage procedure is presented.


Asunto(s)
Enfermedades del Colágeno/patología , Hepatectomía , Complicaciones Intraoperatorias , Hepatopatías/patología , Trasplante de Hígado/métodos , Derivación Portocava Quirúrgica , Adulto , Anastomosis Quirúrgica , Femenino , Hepatitis C/complicaciones , Humanos , Hígado/patología , Hígado/ultraestructura , Cirrosis Hepática/etiología , Cirrosis Hepática/cirugía , Masculino , Persona de Mediana Edad , Vena Porta/cirugía , Reoperación , Rotura Espontánea , Donantes de Tejidos , Vena Cava Inferior/cirugía
10.
Clin Liver Dis ; 2(1): 63-75, vi, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15560046

RESUMEN

Hereditary hemochromatosis is a common disorder of iron metabolism that increasingly is diagnosed and treated prior to the development of cirrhosis or diabetes. The discovery of a candidate gene for hereditary hemochromatosis undoubtedly will result in improved diagnosis of hereditary hemochromatosis and to a better understanding of certain aspects of iron absorption, hepatic iron uptake and release, and whole body iron metabolism. In turn, this enhanced understanding of iron biology can be applied to the observations seen in patients with other hepatic diseases such as chronic viral hepatitis.


Asunto(s)
Hemocromatosis/diagnóstico , Hemocromatosis/genética , Hemocromatosis/terapia , Humanos , Trasplante de Hígado
11.
Chest ; 99(5): 1252-7, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-2019188

RESUMEN

The most common pulmonary complication of EVS is pleural effusion. The most clinically significant pulmonary complication of EVS is delayed perforation with formation of esophagopleural or esophagobronchial fistula. Pneumonia, empyema, pulmonary infarction, and atelectasis can also occur. Endoscopic variceal sclerotherapy probably does not cause ARDS, but that issue remains unsettled. Transient relative pulmonary hypertension during EVS is probably of no clinical significance, but caution is urged when sclerosing varices in a patient with borderline right heart function.


Asunto(s)
Várices Esofágicas y Gástricas/terapia , Hemorragia Gastrointestinal/terapia , Enfermedades Pulmonares/etiología , Derrame Pleural/etiología , Soluciones Esclerosantes/efectos adversos , Escleroterapia/efectos adversos , Extravasación de Materiales Terapéuticos y Diagnósticos , Gastroscopios , Humanos , Mediastinitis/etiología
12.
Arch Ophthalmol ; 101(7): 1049-52, 1983 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6870627

RESUMEN

The incidence of clinically apparent retinal changes in 35 anemic patients and 35 age- and sex-matched control subjects was studied. Retinal photographs of all subjects were obtained. From these, all vascular and extravascular retinal lesions were noted. No retinal abnormalities were observed in the control subjects. Seven (20%) of the anemic patients exhibited extravascular lesions. There was no relationship detected between the occurrence of these changes and the severity or the cause of the anemia. Employing the assumption that true venous length for a given net distance traveled correlates with the degree of venous tortuosity, venous length over a standard radial distance from the optic disc was assessed with a curvometer. A significant negative correlation was determined between venous length and the level of hematocrit, thereby implying that retinal venous tortuosity is directly related to severity of anemia.


Asunto(s)
Anemia/complicaciones , Enfermedades de la Retina/etiología , Adolescente , Adulto , Anciano , Anemia/sangre , Enfermedad Crónica , Femenino , Hematócrito , Humanos , Masculino , Persona de Mediana Edad , Oftalmología , Enfermedades de la Retina/patología , Hemorragia Retiniana/etiología , Vena Retiniana/patología
13.
Med Clin North Am ; 84(5): 1085-105, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11026919

RESUMEN

The 1990s have been an exciting time for the field of hepatology. There has been a rapid expansion of knowledge, and new discoveries have revolutionized the field. It is now possible to characterize and treat many more liver diseases. Newer medications in the form of interferon alfa and nucleoside analogues have been added to the armamentarium for treatment of chronic viral hepatitis. Liver transplantation has been established as an effective therapy for patients with end-stage liver disease.


Asunto(s)
Hepatitis Viral Humana/fisiopatología , Hepatopatías/fisiopatología , Trasplante de Hígado , Predicción , Gastroenterología/tendencias , Hepatitis Crónica/terapia , Hepatitis Viral Humana/diagnóstico , Hepatitis Viral Humana/terapia , Humanos , Interferón-alfa/uso terapéutico , Hepatopatías/diagnóstico , Hepatopatías/terapia , Fallo Hepático/cirugía , Trasplante de Hígado/tendencias , Nucleósidos/uso terapéutico
14.
Med Clin North Am ; 80(5): 1147-66, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8804378

RESUMEN

NASH is a form of chronic liver disease that is defined by biopsy findings and has the appearance of alcoholic hepatitis. Although this disease was once thought to be a problem of women, diabetics, and the obese, more recent studies have identified a significant proportion of patients who do not fit these risk factors. In a fraction of patients, the disease can progress to various stages of fibrosis leading ultimately to cirrhosis and death from end-stage liver disease. For this reason, recognition of NASH is important and provides a further impetus for performing a liver biopsy as part of the evaluation of unexplained liver biochemical abnormalities. The mainstay of treatment is weight reduction in the obese. For those individuals who are not obese, continued observation is the only available option at this point. With increasing knowledge about the pathophysiology of hepatic steatosis, perhaps more specific diagnostic tests for the cause of the disease in specific patients will be available and will guide appropriate therapy.


Asunto(s)
Hígado Graso/diagnóstico , Hepatitis/diagnóstico , Biopsia , Diagnóstico Diferencial , Progresión de la Enfermedad , Hígado Graso/etiología , Hígado Graso/fisiopatología , Hígado Graso/terapia , Hepatitis/etiología , Hepatitis/fisiopatología , Hepatitis/terapia , Humanos , Hígado/patología , Factores de Riesgo
15.
Chem Phys Lipids ; 45(2-4): 207-39, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3319227

RESUMEN

Iron overload can have serious health consequences. Since humans lack an effective means to excrete excess iron, overload can result from an increased absorption of dietary iron or from parenteral administration of iron. When the iron burden exceeds the body's capacity for safe storage, the result is widespread damage to the liver, heart and joints, and the pancreas and other endocrine organs. Clear evidence is now available that iron overload leads to lipid peroxidation in experimental animals, if sufficiently high levels of iron are achieved. In contrast, there is a paucity of data regarding lipid peroxidation in patients with iron overload. Data from experiments using an animal model of dietary iron overload support the concept that iron overload results in an increase in an hepatic cytosolic pool of low molecular weight iron which is catalytically active in stimulating lipid peroxidation. Lipid peroxidation is associated with hepatic mitochondrial and microsomal dysfunction in experimental iron overload, and lipid peroxidation may underlie the increased lysosomal fragility that has been detected in homogenates of liver samples from both iron-loaded human subjects and experimental animals. Some current hypotheses focus on the possibility that the demonstrated functional abnormalities in organelles of the iron-loaded liver may play a pathogenic role in hepatocellular injury and eventual fibrosis. The recent demonstration that hepatic fibrosis is produced in animals with long-term dietary iron overload will allow this model to be used to further investigate the relationship between lipid peroxidation and hepatic injury in iron overload.


Asunto(s)
Hierro/metabolismo , Peróxidos Lipídicos/metabolismo , Hepatopatías/etiología , Hígado/metabolismo , Animales , Hemocromatosis/etiología , Hemocromatosis/metabolismo , Humanos , Hierro/efectos adversos , Hígado/ultraestructura , Hepatopatías/metabolismo , Organoides/metabolismo
16.
Chem Biol Interact ; 70(3-4): 183-226, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2663196

RESUMEN

In both hereditary hemochromatosis and in the various forms of secondary hemochromatosis, there is a pathologic expansion of body iron stores due mainly to an increase in absorption of dietary iron. Excess deposition of iron in the parenchymal tissues of several organs (e.g. liver, heart, pancreas, joints, endocrine glands) results in cell injury and functional insufficiency. In the liver, the major pathological manifestations of chronic iron overload are fibrosis and ultimately cirrhosis. Evidence for hepatotoxicity due to iron has been provided by several clinical studies, however the specific pathophysiologic mechanisms for hepatocellular injury and hepatic fibrosis in chronic iron overload are poorly understood. The postulated mechanisms of liver injury in chronic iron overload include (a) increased lysosomal membrane fragility, perhaps mediated by iron-induced lipid peroxidation, (b) peroxidative damage to mitochondria and microsomes resulting in organelle dysfunction, (c) a direct effect of iron on collagen biosynthesis and (d) a combination of all of the above.


Asunto(s)
Hemocromatosis , Hierro/envenenamiento , Peroxidación de Lípido , Hígado/metabolismo , Animales , Cardiomiopatías/etiología , Hemocromatosis/etiología , Hemocromatosis/metabolismo , Hemocromatosis/patología , Humanos , Hierro/metabolismo , Hígado/patología , Cirrosis Hepática/etiología , Talasemia/metabolismo
17.
Adv Exp Med Biol ; 356: 239-53, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7887229

RESUMEN

There are several inherited and acquired disorders that can result in chronic iron overload in humans, and the major clinical consequences are hepatic fibrosis, cirrhosis, hepatocellular cancer, cardiac disease, and diabetes. It is clear that lipid peroxidation occurs in experimental iron overload if sufficiently high levels of iron within hepatocytes are achieved. Lipid peroxidation is associated with hepatic mitochondrial and microsomal dysfunction in experimental iron overload, and lipid peroxidation may underlie the increased lysosomal fragility that has been detected in liver samples from both iron-loaded human subjects and experimental animals. Reduced cellular ATP levels, impaired cellular calcium homeostasis, and damage to DNA may all contribute to hepatocellular injury in iron overload. Long-term dietary iron overload in rats can lead to increased collagen gene expression and hepatic fibrosis, perhaps due to activation of hepatic lipocytes. The mechanisms whereby lipocytes are activated in iron overload remain to be elucidated; possible mediators include aldehydic products of iron-induced lipid peroxidation produced in hepatocytes, tissue ferritin, and/or cytokines released by activated Kupffer cells.


Asunto(s)
Hemocromatosis/fisiopatología , Hierro/toxicidad , Animales , Citocinas/biosíntesis , Hemocromatosis/metabolismo , Hemocromatosis/patología , Humanos , Macrófagos del Hígado/efectos de los fármacos , Macrófagos del Hígado/inmunología , Macrófagos del Hígado/patología , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/patología , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Lisosomas/patología , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/patología
18.
Hepatogastroenterology ; 41(4): 343-8, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7959569

RESUMEN

An increased production of free radicals in the liver has been implicated in a variety of liver diseases. Free radicals can damage cellular macromolecules and, therefore, may participate in hepatocellular injury when produced in excess. Strong evidence exists for hepatic free radical production in animal models of iron and copper overload, ethanol consumption, and ischemia-reperfusion. Although less is known about the situation in humans with liver diseases, the available evidence is consistent with the findings in animal experiments. Treatments that reduce free radical production and/or levels have protective effects in hepatic ischemia-reperfusion. Free radical-initiated lipid peroxidation may play a role in hepatic fibrogenesis, perhaps through an effect of aldehydic peroxidation products on Kupffer cells and lipocytes. This hypothesis is supported by the observation that dietary supplementation with vitamin E has a protective effect on carbon tetrachloride-induced hepatic fibrosis. While cellular damage in human liver diseases is probably multifactorial, free radicals may play important roles in initiating and/or perpetuating this damage.


Asunto(s)
Cirrosis Hepática/metabolismo , Hepatopatías/metabolismo , Hígado/metabolismo , Intoxicación Alcohólica/metabolismo , Animales , Cobre/toxicidad , Radicales Libres , Humanos , Hierro/toxicidad , Peroxidación de Lípido
19.
Hepatogastroenterology ; 48(37): 212-5, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11268968

RESUMEN

BACKGROUND/AIMS: The mechanism of hepatic fibrogenesis with chronic viral hepatitis is not well understood. Persistent activation of hepatic stellate cells is felt to play a role in the development of fibrogenesis and progression to cirrhosis. METHODOLOGY: We determined the expression of hepatic alpha-smooth muscle actin, a marker of hepatic stellate cell activation, in 29 patients with chronic hepatitis C and varying degrees of liver injury and fibrosis. In addition to a baseline evaluation, we assessed the effect of interferon therapy on alpha-smooth muscle actin expression in 11 patients, including 6 with a sustained response to therapy. Specimens were evaluated by light microscopy for grade of inflammation and stage of fibrosis. Expression of alpha-smooth muscle actin was assessed semiquantitatively by immunohistochemical staining. RESULTS: At baseline, all patients had alpha-smooth muscle actin expressed within the liver without an obvious correlation with the severity of liver injury. However, among sustained responders, a reduction in hepatic necroinflammatory activity was associated with a trend towards a decrease in alpha-smooth muscle actin expression. This however did not reach statistical significance. CONCLUSIONS: Hepatic alpha-smooth muscle actin expression, as a marker of hepatic stellate cell activation appears reversible and tends to correlate with necroinflammatory activity.


Asunto(s)
Actinas/análisis , Antivirales/uso terapéutico , Hepatitis C Crónica/metabolismo , Interferón-alfa/uso terapéutico , Hígado/química , Músculo Liso/metabolismo , Biomarcadores/análisis , Femenino , Fibrosis , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/patología , Hepatocitos/química , Humanos , Inmunohistoquímica , Inflamación , Hígado/patología , Cirrosis Hepática/complicaciones , Masculino , Persona de Mediana Edad
20.
Cleve Clin J Med ; 63(5): 264-8, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8870336

RESUMEN

Although progress has been made toward developing a cheap and accurate method to diagnose hepatitis C virus (HCV) infection, current screening tests have an unacceptably high false-positive rate. Newer tests are more accurate, but also more costly. This paper outlines an approach for interpreting and using these different tests. The second-generation enzyme-linked immunosorbent assay (ELISA) for HCV antibodies, the current screening test for HCV infection, has a sensitivity of approximately 90% but a low specificity. Persons with risk factors for HCV infection, elevated aminotransferase levels, and a positive ELISA result most likely have HCV infection. Confirmatory testing with a recombinant immunoblot assay adds considerably to the cost of diagnosis and should only be used to confirm HCV infection in ELISA-positive patients at low risk or with conditions such as hyperglobulinemia that promote false-positive reactivity. Polymerase chain reaction (PCR) testing is the most sensitive and accurate method of diagnosing HCV infection, but its cost limits its use. PCR testing should be reserved for cases of diagnostic uncertainty, evaluation of possible acute hepatitis C, patients with normal serum aminotransferase levels and anti-HCV antibodies, and patients about to undergo interferon therapy.


Asunto(s)
Hepatitis C/diagnóstico , Pruebas Serológicas/economía , Adulto , Diagnóstico Diferencial , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Masculino , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad
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