Biomedical subjects

Antonio Chedid

Publications and source records attributed to Antonio Chedid.

4 recordsLinked to original sources

PubMed2005

Colchicine treatment of alcoholic cirrhosis: a randomized, placebo-controlled clinical trial of patient survival.

BACKGROUND & AIMS: Colchicine improved survival and reversed cirrhosis in several small clinical trials. We compared the efficacy and safety of long-term colchicine, as compared with placebo, in patients with advanced alcoholic cirrhosis. METHODS: Five hundred forty-nine patients with advanced (Pugh B or C) alcoholic cirrhosis were randomized to receive either colchicine 0.6 mg twice per day (n = 274) or placebo (n = 275). Treatment lasted from 2 to 6 years. The primary outcome was all-cause mortality. Secondary outcomes were liver-related morbidity and mortality. Liver biopsy was requested prior to entry and after 24 months of treatment. RESULTS: Attendance at scheduled clinic visits and adherence with study medication were similar in colchicine and placebo groups. Alcohol intake was less than 1 drink per day in 69% of patients. In an intention-to-treat analysis, all-cause mortality was similar in colchicine (49%) and placebo (45%) patients (P = .371). Mortality attributed to liver disease was 32% in colchicine and 28% in placebo patients (P = .337). Fewer patients receiving colchicine developed hepatorenal syndrome. In 54 patients with repeat liver biopsies after 24 or more months of treatment, cirrhosis improved to septal fibrosis in 7 patients (3 colchicine, 4 placebo) and to portal fibrosis in 1 patient (colchicine). CONCLUSIONS: In patients with advanced alcoholic cirrhosis, colchicine does not reduce overall or liver-specific mortality. Liver histology improves to septal fibrosis in a minority of patients after 24 months of treatment, with similar rates of improvement in patients receiving placebo and colchicine. Colchicine is not recommended for patients with advanced alcoholic cirrhosis.

Colchicine↗

PubMed2004

The immunology of fibrogenesis in alcoholic liver disease.

CONTEXT: Alcoholic liver disease in humans frequently leads to cirrhosis. Experimental models of hepatic fibrogenesis are available, but extrapolation of those findings to human ethanol-induced liver injury is difficult. Hepatic ethanol-induced fibrosis in humans has often been studied in relatively small patient populations. During the past decade, several animal models and human studies have attributed fibrogenesis in the liver to the role played by hepatocytes, Kupffer cells, endothelial cells, and especially stellate cells. OBJECTIVE: To determine the contribution of the main liver cell types to ethanol-induced fibrogenesis. For that purpose, we studied the expression of the following immunologic parameters: smooth muscle-specific alpha actin (SMSA), CD68, CD34, transforming growth factor beta1, intercellular adhesion molecule 1, and collagen types 1 and 3. The Dako LSAB+ kit (peroxidase method) was used. DESIGN: We recently studied a large cohort of patients with alcoholic liver disease in France. In this cohort, we found 87 cases in which liver biopsies revealed only pericentral injury with nonpathologic portal areas. We compared cases in which the portal areas were nonpathologic with 324 patients in whom staging ranged from F0 to F3. Patients with cirrhosis (F4) were excluded from evaluation. To stage fibrosis, we used the METAVIR system. Furthermore, we selected 40 cases in which the biopsies measured at least 25 mm in length for further histochemical evaluation. Ten additional normal cases from our archives were used as controls. We divided this patient population into the following 5 groups of 10 patients each: group 1A, F0 with steatosis; group 1B, F0 without steatosis; group 2, F0 to F1, central injury; group 3, F3, fibrosis with multiple septa; and group 4, nonpathologic livers (controls). RESULTS: Smooth muscle-specific alpha actin was expressed by stellate cells, pericentrally, with increasing severity and intensity in the advanced stage of fibrosis of group 3, less intense expression was noted in group 2, and expression was practically absent in group 1 and in nonpathologic controls. CD68 was the best marker for Kupffer cells and was expressed diffusely within the lobules in all groups. Its expression correlated directly with the degree of disease severity, progressing from stage I through stage III, but was absent in nonpathologic livers. CD34 was consistently expressed by endothelial cells in the periportal areas in all groups. The expression of collagen type 1 was intense in the bands of fibrosis or bridging, while type 3 expression was poor. Transforming growth factor beta1 and intercellular adhesion molecule 1 were not expressed in any group. CONCLUSIONS: In this study, stellate cell activation (SMSA) was most intense pericentrally in the early stages and diffusely with progression to fibrosis and maximum intensity in stage III. Kupffer cell activation, as determined by CD68 expression, was intense and diffuse, while endothelial cells expressed CD34 periportally in a similar manner in all stages. Fibrogenesis in human ethanol injury is due to the activity of stellate cells, Kupffer cells, and to a lesser extent, to endothelial cells.

Adult↗

PubMed2003

A comparison of fibrosis progression in chronic liver diseases.

BACKGROUND/AIMS: No study has compared the liver fibrosis progression rates among chronic liver diseases and the risk factors in order to better organize screening strategies. METHODS: A total of 4852 patients were retrospectively studied (chronic hepatitis C (HCV) [n=2313], human immunodeficiency virus (HIV)-HCV co-infection (HIV-HCV [n=180]), hepatitis B (HBV [n=777]), alcoholic liver disease (ALD [n=701]), primary biliary cirrhosis (PBC [n=406]), genetic hemochromatosis (GH [n=383]) auto-immune hepatitis (AIH [n=57]) and delta hepatitis (n=35). The fibrosis progression rates were estimated from birth and from the date of exposure, when known, to the first biopsy. RESULTS: There were highly significant differences in the rates of fibrosis progression, the most rapid being HIV-HCV co-infection (50% cirrhosis percentile at 52 years of age) and the slowest being PBC (50% cirrhosis percentile at 81 years). There was an acceleration of fibrosis progression with aging. Fibrosis progression was slower in females compared with males for HCV, HBV, GH, and PBC. In contrast, in ALD, the fibrosis progression was more rapid in females. CONCLUSIONS: Rates of fibrosis progression differ markedly between the predominant causes of chronic liver disease, and according to age and gender. Patients with HIV-HCV co-infection are at particularly high risk of fibrosis progression.

Adult↗

PubMedDate not supplied

Aging Liver. A review.

Aging is characterized by a progressive decline of cellular functions. The aging liver appears to preserve its function relatively well. Aging is associated in human liver with morphological changes such as decrease in size attributable to decreased hepatic blood flow. Ultrastructural analysis of the human liver has revealed that the integrity of mitochondria and enzymatic activity remain mostly unchanged with aging. Reactive oxygen species (ROS) are involved in the aging process and result mainly from nonenzymatic processes in the liver. Endogenous free radicals are generated within mitochondria and suspected to cause severe injury to mitochondrial DNA. This damaged DNA accumulates with aging. In addition, polyunsaturated fatty acids, highly sensitive to ROS, decrease in liver mitochondria from human centenarians, a feature acquired during evolution as a protective mechanism to favor longevity. Diet is considered the main environmental factor having effect on lifespan. It has a major impact on aging liver, the central metabolic organ of the body. The ubiquitin proteolytic pathway in the liver serves to destroy many proteins, among them p21 which is encoded by abundant mRNA in senescent cells, can inhibit cell proliferation and favors DNA repair. Drug therapy in the elderly may be complicated by several factors such as decline in body weight, renal function, liver mass and hepatic blood flow, making adverse drug reactions more frequent. Hepatic drug metabolism is mainly mediated by the cytochrome P(450 )system and drug interactions in the elderly are likely related to the progressive decline of this system after the fifth decade of life and another decrease in individuals aged >70. Antihypertensive therapy in the elderly depends upon either hepatic or renal function and should be adjusted accordingly. Finally, telomerases are the biological clocks of replicative lifespan. Shortening of telomeric ends of chromosomes correlates with aging and decline in the replicative potential of the cell: replicative senescence. Telomere DNA of human somatic cells shortens during each cell division thus leading to a finite proliferation. Transfection of the telomerase reverse transcriptase gene results in elongation of telomeres and extension of lifespan. This also applies to humans. Replicative senescence in human cells evolved as a mechanism to protect them from continuous divisions leading to multiple mutations. Longer-lived species such as humans had to develop replicative senescence to ensure that they would have the increased protection that their longevity necessitates.

Aging↗