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Felix Stickel

Publications and source records attributed to Felix Stickel.

17 recordsLinked to original sources
PubMed2006

Alcohol dehydrogenase 1C*1 allele is a genetic marker for alcohol-associated cancer in heavy drinkers.

Chronic alcohol consumption is associated with an increased risk for upper aerodigestive tract cancer and hepatocellular carcinoma. Increased acetaldehyde production via alcohol dehydrogenase (ADH) has been implicated in the pathogenesis. The allele ADH1C*1 of ADH1C encodes for an enzyme with a high capacity to generate acetaldehyde. So far, the association between the ADH1C*1 allele and alcohol-related cancers among heavy drinkers is controversial. ADH1C genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism in a total of 818 patients with alcohol-associated esophageal (n=123), head and neck (n=84) and hepatocellular cancer (n=86) as well as in patients with alcoholic pancreatitis (n=117), alcoholic liver cirrhosis (n=217), combined liver cirrhosis and pancreatitis (n=17) and in alcoholics without gastrointestinal organ damage (n=174). The ADH1C*1 allele and genotype ADH1C*1/1 were significantly more frequent in patients with alcohol-related cancers than that in individuals with nonmalignant alcohol-related organ damage. Using multivariate analysis, ADH1C*1 allele frequency and rate of homozygosity were significantly associated with an increased risk for alcohol-related cancers (p<0.001 in all instances). The odds ratio for genotype ADH1C*1/1 regarding the development of esophageal, hepatocellular and head and neck cancer were 2.93 (CI, 1.84-4.67), 3.56 (CI, 1.33-9.53) and 2.2 (CI, 1.11-4.36), respectively. The data identify genotype ADH1C*1/1 as an independent risk factor for the development of alcohol-associated tumors among heavy drinkers, indicating a genetic predisposition of individuals carrying this genotype.

Adult↗
PubMed2006

The role of genetic polymorphisms in alcoholic liver disease.

Chronic alcohol consumption is a major cause of liver cirrhosis which, however, develops in only a minority of heavy drinkers. Evidence from twin studies indicates that genetic factors account for at least 50% of individual susceptibility. The contribution of genetic factors to the development of diseases may be investigated either by means of animal experiments, through linkage studies in families of affected patients, or population based case-control studies. With regard to the latter, single nucleotide polymorphisms of genes involved in the degradation of alcohol, antioxidant defense, necroinflammation, and formation and degradation of extracellular matrix are attractive candidates for studying genotype-phenotype associations. However, many associations in early studies were found to be spurious and could not be confirmed in stringently designed investigations. Therefore, future genotype-phenotype studies in alcoholic liver disease should meet certain requirements in order to avoid pure chance observations due to a lack of power, false functional interpretation, and insufficient statistical evaluation.

Animals↗
PubMed2006

Keratin variants associate with progression of fibrosis during chronic hepatitis C infection.

Keratins 8 and 18 (K8/K18) protect the liver from various forms of injury. Studies of liver explants from a large cohort of U.S. patients showed that K8/K18 mutations confer a risk to developing end-stage liver diseases, though which diseases are preferentially involved is unknown. We tested the hypothesis that K8/K18 variants are associated with chronic hepatitis C (CHC) and that their presence correlates with progression of fibrosis. Genomic DNA was isolated from peripheral blood of a well-characterized German cohort of 329 patients with CHC infection. Exonic regions were PCR-amplified and analyzed using denaturing high-performance liquid chromatography and DNA sequencing. Our findings showed: (1) amino acid altering keratin heterozygous variants in 24 of 329 CHC patients (7.3%) and non-coding heterozygous variants in 26 patients (7.8%), and (2) 3 new exonic K8 variants (T26R/G55A/A359T); 6 novel non-coding variants and one K18 coding variant (K18 S230T; 2 patients). The most common variants were K8 R341H (10 patients), K8 G62C (6 patients) and K8 I63V (4 patients). A novel and exclusive association of an intronic KRT8 IVS7+10delC deletion in all 10 patients with K8 R341H was observed. Notably, there was a significant association of exonic, but not of intronic K8 variants with increased fibrosis. In conclusion, previously described and novel K8 variants are present in a German population and collectively associate with progression of fibrosis in CHC infection. The unique 100% segregation of the most common K8 variant, R341H, with an intronic deletion suggests that one of these two genetic changes might lead to the other.

Adult↗
PubMed2006

Risk factors and mechanisms of hepatocarcinogenesis with special emphasis on alcohol and oxidative stress.

Hepatocellular cancer is the fifth most frequent cancer in men and the eighth in women worldwide. Established risk factors are chronic hepatitis B and C infection, chronic heavy alcohol consumption, obesity and type 2 diabetes, tobacco use, use of oral contraceptives, and aflatoxin-contaminated food. Almost 90% of all hepatocellular carcinomas develop in cirrhotic livers. In Western countries, attributable risks are highest for cirrhosis due to chronic alcohol abuse and viral hepatitis B and C infection. Among those with alcoholic cirrhosis, the annual incidence of hepatocellular cancer is 1-2%. An important mechanism implicated in alcohol-related hepatocarcinogenesis is oxidative stress from alcohol metabolism, inflammation, and increased iron storage. Ethanol-induced cytochrome P-450 2E1 produces various reactive oxygen species, leading to the formation of lipid peroxides such as 4-hydroxy-nonenal. Furthermore, alcohol impairs the antioxidant defense system, resulting in mitochondrial damage and apoptosis. Chronic alcohol exposure elicits hepatocyte hyperregeneration due to the activation of survival factors and interference with retinoid metabolism. Direct DNA damage results from acetaldehyde, which can bind to DNA, inhibit DNA repair systems, and lead to the formation of carcinogenic exocyclic DNA etheno adducts. Finally, chronic alcohol abuse interferes with methyl group transfer and may thereby alter gene expression.

Alcohol Drinking↗
PubMed2005

Prediction of progression to cirrhosis by a glutathione S-transferase P1 polymorphism in subjects with hereditary hemochromatosis.

BACKGROUND: Oxidative stress plays an important pathogenic role in hereditary hemochromatosis (HHC) and chronic hepatitis C virus infection (CHC). Several enzymes involved in the degradation of reactive oxidants and xenobiotics, such as glutathione S-transferase P1 (GSTP1) and manganese superoxide dismutase (MnSOD), reveal polymorphisms that affect their antioxidant capacity and may therefore modulate the progression to cirrhosis. Our objective was to establish the role of the functional polymorphisms of GSTP1 (codon 105 Ile-->Val) and MnSOD (codon 16 of precursor protein Ala-->Val) on the evolution of cirrhosis in patients with HHC and CHC. METHODS: One hundred seventy-two patients with HHC who were homozygous for the C282Y mutation and 285 patients with CHC underwent liver biopsy and genotyping for the GSTP1 and MnSOD polymorphisms. RESULTS: In HHC, the GSTP1 Val/Val genotype was more common in patients with than in those without cirrhosis (14.8% vs 2.1%, P = .009), whereas the distribution of MnSOD variants was not different. Logistic regression analysis identified GSTP1 Val/Val genotype, serum ferritin level, male sex, and age as independent predictors for the presence of cirrhosis. The odds ratio for the GSTP1 Val/Val genotype for the development of cirrhosis was 3.85 (95% confidence interval, 1.18-12.62; P = .03). However, in patients with CHC, the GSTP1 and MnSOD genotypes were not associated with cirrhosis. CONCLUSIONS: Cirrhosis is more likely to develop in C282Y homozygotes with the GSTP1 Val/Val genotype than in those with non-Val/Val genotypes, which in part explains the variable phenotypic expression of HHC and highlights the central role of oxidative stress in its pathogenesis.

Adult↗
PubMed2005

Herbal hepatotoxicity.

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Chemical and Drug Induced Liver Injury↗
PubMed2005

TGF-beta1 codon 25 gene polymorphism is associated with cirrhosis in patients with hereditary hemochromatosis.

Hereditary hemochromatosis (HHC) is an autosomal recessive disorder of iron metabolism with variable penetrance. Only a minority of C282Y homozygotes develop clinical overt disease and cirrhosis. The phenotypic heterogeneity of HHC may be due to host genetic factors influencing fibrogenesis such as cytokine gene polymorphisms. In this respect, we investigated the impact of functional genetic polymorphisms of TGF-beta1 (codon 10 Leu/Pro, codon 25 Arg/Pro), TNF-alpha (-308 G/A, -238 G/A) and angiotensinogen (-6 G/A) on the development of cirrhosis in HHC. One hundred and forty-nine (111 male, mean age: 51.0+/-12.9) C282Y homozygotes who underwent liver biopsy were studied. Genotyping was performed by RFLP analysis. TGF-beta1 codon 25 genotypes Arg/Pro and Pro/Pro were more common in patients with cirrhosis than in those without (23.6% vs. 7.4%, p = 0.005). In contrast, the distribution of TGF-beta1 codon 10, TNF-alpha and angiotensinogen genotypes was not different. Logistic regression analysis identified male sex, age, serum ferritin and TGF-beta1 codon 25 Arg/Pro and Pro/Pro as independent predictors for the presence of cirrhosis. The adjusted odds ratio for TGF-beta1 codon 25 Arg/Pro and Pro/Pro was 2.8 (95% CI 1.4-5.7, p = 0.004). In conclusion, C282Y homozygotes carrying TGF-beta1 genotypes Arg/Pro and Pro/Pro are more likely to develop cirrhosis than those with genotype Arg/Arg.

Adult↗
PubMed2005

Association of myeloperoxidase promotor polymorphism with cirrhosis in patients with hereditary hemochromatosis.

BACKGROUND/AIMS: Hereditary hemochromatosis (HHC) is a disorder of iron metabolism with variable penetrance. Oxidative stress plays a central role in the progression to cirrhosis. Several enzymes involved in the production or degradation of reactive oxidants, like myeloperoxidase (MPO) and heme oxygenase (HO)-1 are influenced by promotor polymorphisms. This study assessed the impact of polymorphisms of the MPO (-463G/A) and the HO-1 promotors of Vienna (GT)n on the evolution of cirrhosis in patients with HHC. METHODS: One-hundred and fifty-eight C282Y homozygotes without cofactors for fibrosis progression (119 males; mean age: 51.0+/-13.3) were studied. All patients underwent liver biopsy. Hepatic iron content was measured by atom absorption spectrophotometry. MPO polymorphism was assessed by RFLP analysis; HO-1 microsatellite polymorphism by a laser-based semi-automated DNA sequencer. RESULTS: The MPO genotypes GG, GA, and AA were found in 102 (64.6%), 45 and 11 patients, respectively. The GG-genotype was more common in patients with cirrhosis than in those without (78.7 vs. 55.7%, P=0.003). The distribution of HO-1 genotypes was not different. Logistic regression analysis revealed MPO genotype-GG, serum ferritin, age and male sex as independent predictors for cirrhosis. CONCLUSIONS: MPO genotype GG is associated with cirrhosis in patients with hereditary hemochromatosis.

Adult↗
PubMed2005

Hepatotoxicity of alcohol-induced polar retinol metabolites involves apoptosis via loss of mitochondrial membrane potential.

Chronic alcohol consumption depletes hepatic vitamin A stores. However, vitamin A supplementation is hepatotoxic, which is further potentiated by concomitant alcohol consumption. It was suggested that polar retinol metabolites generated by alcohol-inducible cytochrome P4502E1 aggravate liver damage. However, experimental evidence supporting this hypothesis is lacking. To elucidate the effects of polar retinol metabolites on cultured HepG2 cells and primary rat hepatocytes, polar retinol metabolites were extracted from liver tissues of rats fed either an alcoholic or isocaloric control Lieber-DeCarli diet. Cell toxicity assays included morphology assessment, trypan blue exclusion test, and LDH/AST leakage. Staining for DAPI and acridine orange, FACS analysis, and Western blot for cleaved caspase-9 and -3 were used to detect apoptosis. Polar retinol metabolites caused marked cytotoxicity in a concentration- and time-dependent manner in both cell types reflected by morphological changes, a dramatic increase in trypan blue positive cells, and LDH/AST leakage. Toxicity was due to apoptosis, as demonstrated by a time-dependent increase of sub-G1 cellular events, a rapid loss of mitochondrial membrane potential, and a time-dependent activation of caspase-9 and -3. No toxicity was found with equivalent doses of the control extract from nonalcoholic rats. We demonstrate that polar retinol metabolites cause marked hepatocyte death through the induction of apoptosis.

Animals↗
PubMed2005

Alcohol consumption and cancer of the gastrointestinal tract.

Epidemiological data have identified chronic alcohol consumption as a significant risk factor for upper gastrointestinal cancer (oropharynx, hypopharynx, esophagus) and colorectal cancer. Pathophysiological mechanisms include generation of acetaldehyde (AA) and reactive oxygen species (ROS), induction of cytochrome P 4502E1 (CYP2E1), and local and nutritional factors. Genetic polymorphisms of alcohol-metabolizing enzymes may individually influence the risk of carcinogenesis. AA, the first and major metabolite of ethanol, has proven to be the most carcinogenic and mutagenic agent in alcohol-associated cancer. Gastrointestinal bacteria as well as various isozymes of alcohol dehydrogenase (ADH) are capable of metabolizing ethanol to AA thus leading to an increased cell turnover of the gastrointestinal mucosa after chronic alcohol consumption. In Caucasians, ADH1C polymorphism is most important, for the ADH1C*1 transcription results in an ADH isoenzyme 2.5 times more active than that from ADH1C*2, which is associated with an increase in AA production. Additionally, oxidative stress due to an induction of CYP2E1 in the gastrointestinal mucosa of alcoholics should be considered as another key factor in alcohol-induced carcinogenesis. Nutritional deficiencies, i.e. lack of folic and retinoic acid, as well as malnutrition itself may also contribute to the development of gastrointestinal cancer.

Alcohol Drinking↗
PubMed2004

Alcohol and cancer: genetic and nutritional aspects.

Chronic alcohol consumption is a major risk factor for cancer of upper aero-digestive tract (oro-pharynx, hypopharynx, larynx and oesophagus), the liver, the colo-rectum and the breast. Evidence has accumulated that acetaldehyde is predominantly responsible for alcohol-associated carcinogenesis. Acetaldehyde is carcinogenic and mutagenic, binds to DNA and protein, destroys the folate molecule and results in secondary cellular hyper-regeneration. Acetaldehyde is produced by mucosal and cellular alcohol dehydrogenase, cytochrome P450 2E1 and through bacterial oxidation. Its generation and/or its metabolism is modulated as a result of polymorphisms or mutations of the genes responsible for these enzymes. Acetaldehyde can also be produced by oral bacteria. Smoking, which changes the oral bacterial flora, also increases salivary acetaldehyde. Cigarette smoke and some alcoholic beverages, such as Calvados, contain acetaldehyde. In addition, chronic alcohol consumption induces cytochrome P450 2E1 enxyme activity in mucosal cells, resulting in an increased generation of reactive oxygen species and in an increased activation of various dietary and environmental carcinogens. Deficiencies of riboflavin, Zn, folate and possibly retinoic acid may further enhance alcohol-associated carcinogenesis. Finally, methyl deficiency as a result of multiple alcohol-induced changes leads to DNA hypomethylation. A depletion of lipotropes, including methionine, choline, betaine and S-adenosylmethionine, as well as folate, results in the hypomethylation of oncogenes and may lead to DNA strand breaks, all of which are associated with increased carcinogenesis.

Acetaldehyde↗
PubMed2003

Hepatitis induced by Kava (Piper methysticum rhizoma).

BACKGROUND/AIMS: Botanical drugs are widely used and often contain highly active compounds. Kava root (Piper methysticum rhizoma), used frequently in Europe as a remedy against anxiety, contains kavapyrones with sedative effects. Seven case reports suggested the development of hepatitis after the intake of Kava. METHODS: We analyzed 29 novel cases of hepatitis along with Kava ingestion which occurred between 1990 and 2002 in addition to the seven already published case reports using a clinical diagnostic scale established for adverse hepatic drug reactions. RESULTS: Hepatic necrosis or cholestatic hepatitis were noticed with both alcoholic and acetonic Kava extracts. The majority of the 29 patients and the additional seven published reports were women (27 females, nine males). Both the cumulative dose and the latency to when the hepatotoxic reaction emerged were highly variable. Nine patients developed fulminant liver failure, of which eight patients underwent liver transplantation. Three patients died, two following unsuccessful liver transplantation and one without. In all other patients, a complete recovery was noticed after the withdrawal of Kava. Pathophysiologically, both immunoallergic and idiosyncratic factors may be responsible. CONCLUSIONS: The present report emphasizes the potentially severe hepatotoxicity of Kava which has recently led to the retraction of Kava-containing drugs by the pharmacovigilance authorities in Germany.

Acute Disease↗
PubMed2003

Weekly high-dose 5-fluorouracil as 24-h infusion and folinic acid (AIO) plus irinotecan as second- and third-line treatment in patients with colorectal cancer pre-treated with AIO plus oxaliplatin.

Our objective was to evaluate the efficacy and safety of high-dose 5-fluorouracil (5-FU) as a 24-h infusion and folinic acid (FA) (AIO regimen) plus irinotecan (CPT-11) after pre-treatment with AIO plus oxaliplatin (L-OHP) in colorectal carcinoma (CRC). Twenty-six patients with non-resectable distant CRC metastases were analyzed for second- or third-line treatment with AIO plus CPT-11 after pre-treatment with AIO plus L-OHP. On an outpatient basis, the patients received a treatment regimen comprising weekly 80 mg/m2 CPT-11 in the form of a 1-h i.v. infusion and 500 mg/m2 FA as a 1- to 2-h i.v. infusion, followed by 2000 mg/m2 5-FU i.v. administered as a 24-h infusion once weekly. A single treatment cycle comprised six weekly infusions followed by 2 weeks of rest. A total of 26 patients received 344 chemotherapy applications with AIO plus CPT-11. The main symptom of toxicity was diarrhea (NCI-CTC toxicity grade 3+4) occurring in five patients (19%; 95% CI 7-39%). Nausea and vomiting presented in two patients (8%; 95% CI 1-25%). The response rate of 26 patients can be summarized as follows: partial remission: n=7 (27%; 95% CI 12-48%); stable disease: n=9 (35%; 95% CI 17-56%) and progressive disease: n=10 (38%; 95% CI 20-59%). The median progression-free survival (n=26) was 5.8 months (range 3-13), the median survival time counted from the treatment start with the AIO plus CPT-11 regimen was 10 months (range 2-24) and counted from the start of first-line treatment (n=26) was 23 months (range 10-66). We conclude that the AIO regimen plus CPT-11 is practicable in an outpatient setting and well tolerated by the patients. Tumor control was achieved in 62% of the patients. The median survival time was 10 months and the median survival time from the start of first-line treatment (n=26) was 23 months.

Adult↗
PubMed2003

Serum hyaluronate correlates with histological progression in alcoholic liver disease.

OBJECTIVES: Chronic alcohol consumption may lead to the development of liver cirrhosis. Serum concentrations of hyaluronate were suggested as a predictor in chronic liver disease, but its power to distinguish between severity of fibrosis and inflammation had not been assessed. In order to evaluate hyaluronate as a marker to detect early stages of alcoholic liver disease and to establish a possible correlation with hepatic histology, serum concentrations were measured by radioimmunoassay in 87 patients with biopsy-proven fatty liver, fatty liver and mild fibrosis, fatty liver and inflammation, severe fibrosis and inflammation, and cirrhosis, and in 12 non-alcoholic control subjects. In addition, serum hyaluronate was determined in 40 non-cirrhotic alcoholic patients with either a normal serum aspartate aminotransferase (AST) or an AST elevated at least two-fold. RESULTS: Serum hyaluronate increased significantly with advanced stages of alcoholic liver disease, while levels in patients with fatty liver were elevated only slightly without reaching significance. Hyaluronate correlated well with histological stage and was highly sensitive for detecting fibrosis in general and perivenular fibrosis as an indicator of progression to cirrhosis. Hyaluronate levels were not influenced by AST levels. CONCLUSION: Serum hyaluronate is a good predictor of the presence of even moderate hepatic fibrosis in alcoholic liver disease, justifying its clinical use to assess morphological alterations of the liver in alcoholics.

Biomarkers↗