Increased glutathione in cultured hepatocytes associated with induction of cytochrome P-450. Lack of effect of glutathione depletion on induction of cytochrome P-450 and delta-aminolevulinate synthase

Cellular glutathione concentrations in primary cultures of chick embryo hepatocytes were 15.3 +/- 5.3 nmoles/mg protein (mean +/- S.D.) and remained stable for up to 3 days in culture. The presence of insulin was not essential for the maintenance of glutathione concentrations. Induction of cytochrome P-450 by phenobarbital-like inducers (2-propyl-2-isopropylacetamide, 2-allyl-2-isopropylacetamide, and 2,4,5,2',4',5'-hexabromobiphenyl) was accompanied by 2- to 3-fold increases in glutathione concentrations and by increased glucuronidation of phenol red. The 3-methylcholanthrene-like inducers of cytochrome P-450 (beta-naphthoflavone and 3,4,3',4'-tetrachlorobiphenyl) did not have these effects. Glutathione was rapidly depleted to 15-30% of control levels in hepatocytes treated with buthionine sulfoximine, an inhibitor of gamma-glutamylcysteine synthase. No toxicity was observed with glutathione depletion. Glutathione depletion did not affect the ability of 2-propyl-2-isopropylacetamide to induce cytochrome P-450, glucuronidation of phenol red, or delta-aminolevulinate synthase.     

Effects of a single dose of oral iron on hepcidin concentrations in human urine and serum analyzed by a robust LC-MS/MS method

BackgroundThe measurement of serum hepcidin, a peptide hormone that regulates iron metabolism, is clinically important to the understanding of iron homeostasis in health and disease. To date, the quantification of serum hepcidin levels by conventional immunological detection methods has proven problematic due to challenges in obtaining high quality antibodies which demonstrate good reproducibility. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) has been employed recently for more sensitive quantification of hepcidin; however, this method has high background levels and therefore less than optimal specificity.MethodsIn order to increase the specificity of the mass spectrometry based assay, we developed a robust, ultra-performance liquid-chromatography-tandem mass spectrometry (UPLC-MS/MS) protocol using multiple selected reaction monitoring (mSRM) for quantification of hepcidin levels in urine and serum of human subjects. With this assay, we assessed levels of hepcidin before and for up to 8 h after oral ingestion of ferrous sulfate in ten adult human subjects without known disease.ResultsThe linear response of hepcidin quantitation on each instrument was measured, and the correlation coefficients of these calibrations were r² = 0.9512 ± 0.0202 (n = 5) for urine and r² = 0.9709 ± 0.0291 (n = 5) for serum [r² = mean ± SD]. Compared to baseline, the levels of urinary hepcidin between 2–4 h and 4–8 h of both women and men showed significant increases with p < 0.05 and p < 0.001, respectively. The levels of serum hepcidin between 4 h and 8 h in both women and men showed significant increases, compared with baseline values, with both p < 0.01. Interestingly, we also observed some degree of oscillation of levels, occurring at later time points.ConclusionsWe have developed and validated a new method for measuring hepcidin concentrations in human serum and urine and used it to demonstrate early increases with iron supplement in both urinary and serum levels of hepcidin, which return to baseline levels, except in urine samples from men.     

Excess mortality in patients with advanced chronic hepatitis C treated with long-term peginterferon

Chronic hepatitis C virus infection can cause chronic liver disease, cirrhosis and liver cancer. The Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial was a prospective, randomized controlled study of long-term, low-dose peginterferon therapy in patients with advanced chronic hepatitis C who failed to respond to a previous course of optimal antiviral therapy. The aim of this follow-up analysis is to describe the frequency and causes of death among this cohort of patients. Deaths occurring during and after the HALT-C Trial were reviewed by a committee of investigators to determine the cause of death and to categorize each death as liver- or nonliver-related and as related or not to complications of peginterferon. Rates of liver transplantation were also assessed. Over a median of 5.7 years, 122 deaths occurred among 1,050 randomized patients (12%), of which 76 were considered liver-related (62%) and 46 nonliver-related (38%); 74 patients (7%) underwent liver transplantation. At 7 years the cumulative mortality rate was higher in the treatment compared to the control group (20% versus 15%, P = 0.049); the primary difference in mortality was in patients in the fibrosis compared to the cirrhosis stratum (14% versus 7%, P = 0.01); comparable differences were observed when liver transplantation was included. Excess mortality, emerging after 3 years of treatment, was related largely to nonliver-related death; liver-related mortality was similar in the treatment and control groups. No specific cause of death accounted for the excess mortality and only one death was suspected to be a direct complication of peginterferon. CONCLUSION: Long-term maintenance peginterferon in patients with advanced chronic hepatitis C is associated with an excess overall mortality, which was primarily due to nonliver-related causes among patients with bridging fibrosis.     

Chinese medicine for treatment of chronic hepatitis B

<正>Contemporary Western medicines approved by the U.S.Food and Drug Administration(FDA) for the treatment of chronic hepatitis B(CHB),although available in China,have high costs,or major side effects and limited effectiveness. Research efforts have focused on looking for natural products as alternative medicines with low cost and good safety for CHB treatment.Chinese medicine(CM) has ancient,time-honored theories about methods of diagnosis and treatment for liver diseases.In recent decades,a large number of clinical trials and pre-clinical studies,which were performed in China and other countries,indicated that CM has potential benefit in several aspects of the treatment of CHB,e.g.,anti-inflammatory, anticancer,antioxidant,immunomodulating,antifibrosis,and antiviral.However,there are many concerns regarding the study design and the quality of clinical trials.Further larger,stringently designed,double-blind,placebo control,randomized clinical trials and long-term follow-up are needed to provide conclusive evidence of their efficacy and safety.Components of CM deserve further study in pre-clinical models of HBV infection and in clinical trials world-wide.