Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Little is known about treatment of hepatitis C virus (HCV) infection in "other groups" than the general population, namely patients with hematologic or renal disorders and patients with human immune deficiency (HIV) co-infection. The aim was to better define HCV therapies in these groups. We analyzed the medical literature focusing on treatment of HCV infection in other populations to suggest conclusions about indications based on tolerance and efficacy. As in the general population, the decision to treat should be based mainly on liver pathology, and to a lesser extent on virologic profiles (genotype, quantitative viremia). Hemophilia does not modify therapeutic strategies which combine interferon-alpha and ribavirin. Similar combinations should be discussed in patients with inherited hemoglobin disorders but iron overload (secondary hemochromatosis) associated with multiple transfusions may decrease the potential efficacy of interferon-alpha and chronic anemia may limit the use of ribavirin. In hemodialyzed patients, therapy by interferon-alpha is feasible with 3 MU subcutaneously after each hemodialysis three times weekly for 6-12 months. Virologic results are at least similar to those obtained in the general population with frequent pathological improvement. Combinations are not possible because ribavirin is contraindicated for pharmacokinetic reasons. In kidney recipients, interferon-alpha is deleterious and inefficient; ribavirin monotherapy has a potential interest which remains to be evaluated. In HIV co-infected patients, treatment is mandatory given the high rate of cirrhosis and the improved survival related to multiple anti-HIV therapies (which have no clear efficacy for quantitative HCV viremia). Due to the limited efficacy of interferon-alpha monotherapy, the combination of interferon-alpha and ribavirin appears to be the logical treatment. An important point is the in vitro inhibition of phosphorylation by ribavirin of HIV reverse transcriptase inhibitors which has to be analyzed in vivo before the combination can be recommended. On the basis of the results of liver biopsy, antiviral treatments may be proposed for HCV-infected patients with hematologic or renal disorders as well as for HIV co-infected patients. The choice of therapy (monotherapy or combined therapies) should be based on the clinical situation (contraindicated with chronic anemia or renal failure, for example) and its duration on the virologic factors of response as in the general population.
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PMID:Treatment of chronic hepatitis C in special groups. 1062 89

Experimental data suggest the antimicrobial peptide hepcidin as a central regulator in iron homeostasis. In this study, we characterized the expression of human hepcidin in experimental and clinical iron overload conditions, including hereditary hemochromatosis. Using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we determined expression of hepcidin and the most relevant iron-related genes in liver biopsies from patients with hemochromatosis and iron-stain-negative control subjects. Regulation of hepcidin mRNA expression in response to transferrin-bound iron, non-transferrin-bound iron, and deferoxamine was analyzed in HepG2 cells. Hepcidin expression correlated significantly with serum ferritin levels in controls, whereas no significant up-regulation was observed in patients with hemochromatosis despite iron-overload conditions and high serum ferritin levels. However, patients with hemochromatosis showed an inverse correlation between hepcidin transcript levels and the serum transferrin saturation. Moreover, we found a significant correlation between hepatic transcript levels of hepcidin and transferrin receptor-2 irrespective of the iron status. In vitro data indicated that hepcidin expression is down-regulated in response to non-transferrin-bound iron. In conclusion, the presented data suggest a close relationship between the transferrin saturation and hepatic hepcidin expression in hereditary hemochromatosis. Although the causality is not yet clear, this interaction might result from a down-regulation of hepcidin expression in response to significant levels of non-transferrin-bound iron.
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PMID:Expression of hepcidin in hereditary hemochromatosis: evidence for a regulation in response to the serum transferrin saturation and to non-transferrin-bound iron. 1263 25

Hemochromatosis (iron storage disease) has been reported in diverse mammals including bottlenose dolphins (Tursiops truncatus). The primary cause of excessive iron storage in humans is hereditary hemochromatosis. Most human hereditary hemochromatosis cases (up to 90%) are caused by a point mutation in the hfe gene, resulting in a C282Y substitution leading to iron accumulation. To evaluate the possibility of a hereditary hemochromatosis-like genetic predisposition in dolphins, we sequenced the bottlenose dolphin hfe gene, using reverse transcriptase-PCR and hfe primers designed from the dolphin genome, from liver of affected and healthy control dolphins. Sample size included two case animals and five control animals. Although isotype diversity was evident, no coding differences were identified in the hfe gene between any of the animals examined. Because our sample size was small, we cannot exclude the possibility that hemochromatosis in dolphins is due to a coding mutation in the hfe gene. Other potential causes of hemochromatosis, including mutations in different genes, diet, primary liver disease, and insulin resistance, should be evaluated.
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PMID:Preliminary investigation of bottlenose dolphins (Tursiops truncatus) for hfe gene-related hemochromatosis. 2507 39