Increased oxidative stress associated with the severity of the liver disease in various forms of hepatitis B virus infection

BACKGROUND: Oxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. There is limited information about the oxidative status in subjects with hepatitis B virus infection. We aimed to evaluate the oxidative status in patients with various clinical forms of chronic hepatitis B infection. METHODS: Seventy-six patients with hepatitis B virus infection, in whom 33 with chronic hepatitis, 31 inactive carriers and 12 with cirrhosis, and 16 healthy subjects were enrolled. Total antioxidant response and total peroxide level measurement, and calculation of oxidative stress index were performed in all participants. RESULTS: Total antioxidant response was significantly lower in cirrhotics than inactive HbsAg carriers and controls (p = 0.008 and p = 0.008, respectively). Total peroxide level and oxidative stress index was significantly higher in cirrhotic (p < 0.001, both) and chronic hepatitis B subjects (p < 0.001, both) than inactive HbsAg carriers and controls. Total antioxidant response was comparable in chronic hepatitis B subjects, inactive HbsAg carriers and controls (both, p > 0.05/6). Total peroxide level and oxidative stress index were also comparable in inactive HBsAg carriers and controls (both, p > 0.05/6). Serum alanine amino transferase level was positively correlated with total peroxide level and oxidative stress index only in chronic hepatitis B subjects (p = 0.002, r = 0.519 and p = 0.008, r = 0.453, respectively). CONCLUSION: Oxidative stress occurs secondarily to increased total lipid peroxidation and inadequate total antioxidant response and is related to severity of the disease and replication status of virus in hepatitis B infection

neonatal bilirubin levels

The effect of haematocrit and beta-carotene levels on the serum total bilirubin measurement in two analytical methods was studied as an example of the impact of practical analytical quality in medical decision making. The precision characteristics of the two methods were very similar. Based upon the significant difference in the correlation coefficient in a method comparison study before and after 20% trimming of the data, an interference effect study was performed. Haemoglobin (expressed as haematocrit) and beta-carotene were the substances studied to explain the observed differences. The bilirubin test results from the Wake bilirubinometer were easily affected (n =19; X(S): 13.83 +/- 2.43; t = -6.17; P = 0.000) and more elevated than in the Vitros dry chemistry systems (n = 18; X(S): 12.72 +/- 2.21; t = -2.48; P = 0.017), due to the presence of beta-carotene (>200 mu g/dl)

The use of split-sample design for performance evaluation of screening kits

European Conference on Quality in the Spotlight in Medical Laboratories -- MAR 17-18, 2003 -- Antwerp, BELGIUMWOS: 000189240600012Laboratory medicine is an important discipline in health care with its remarkable effect on risk assessment, diagnosis of health, and disease state. This accounts describes a newborn screening approach involving retest, recall, and follow-up procedures. This real life trial emphasizes the need for split-sample design evaluation of newly opened test kits. Quantitative measurements of phenylalanine and neonatal thyroid stimulating hormone (nTSH) were performed in two laboratories. After validation of the calibration in the laboratory that was using the industrially prepared screening kits for the first time, the same real newborn blood spot samples were analyzed for phenylalanine and nTSH measurements in both laboratories and the results obtained were compared non-parametrically, and examined by Deming regression and difference plots. There was no problem with the phenylalanine results: similar results were obtained for the same blood spot cards in both laboratories (P=0.496; bias estimation 0.13). However, the nTSH values were found to be significantly higher in the laboratory that used the nTSH kit for the first time. Although the validation of the calibration of the nTSH kit was valid with the manufacture's control materials, spilt-sample results showed that there was a significant difference between the two laboratories (P=0.005; bias estimation 28.6). This study implies that acceptable comparability of split-sample design analysis is needed for testing the analytical performance of industrially prepared tests kits, and this can only be achieved with certified reference materials

method used

It is particularly important, when analyzing biological material, for the measurement procedure to be specific to the analyte and not to suffer interference by the matrix effect. Tissue fraction studies also require rapid and accurate methods to estimate the concentration of protein in solutions as well as many measurement methods used in medical laboratories. The design of this study is based on a comparison of the Lowry and the bicinchoninic acid (BCA) methods for the measurement of the total protein concentrations of rat liver subcellular fractions. In our experiment, subcellular fractions enriched in peroxisomes (POs) obtained by differential centrifugation were then further separated by means of density gradient centrifugation. We performed the protein measurement assays on all fractions obtained during the purification steps. The protein contents of the fractions obtained were determined by the two methods. The method comparison statistics were performed by linear Deming regression analysis and Altman and Bland bias plot. The regression equation was unacceptable, indicating that the last three fractions separated by means of Nycodenz discontinuous density gradient centrifugation gave remarkably divergent results. For the Lowry method, the Nycodenz effect could not be eliminated with the use of interference blank. In addition to Nycodenz, the potentially interfering compound used in the isolation procedure as isolation medium was 3-(morpholino)propane sulfonic acid (MOPS). In decreased concentrations of MOPS (10 mM), interference blank should be used for correct measurement with Lowry, but in practical use 10 mM does not provide buffering potency. In the BCA method, interference blank correction seemed to eliminate the measurement error in all concentrations of Nycodenz. There was no MOPS effect on the BCA measurement assay. Referring to deviations as sample-inherent matrix effects, we concluded that not only one, but more measurement methods should be used in order to make a correct protein measurement

Erythrocyte membrane ATPase measurement can be a marker of CCL4-induced liver cirrhosis

Erythrocyte membrane and liver plasma membrane of CCl4 treated rats were isolated to measure Na+, K+ and Ca2+ ATPase activities. Membrane lipid extraction was also performed to calculate cholesterol/phospholipid ratios. Histopathological evaluation of each cirrhotic liver of 9 different rats were determined in order to give a pathological scare. The purpose of this study is to investigate if erythrocyte membrane ATPase measurement will be safe and useful marker of liver damage caused by CCl4. In order to confirm this question; we isolated the rat liver plasma membrane fractions and proved that they are pure enough and measured the plasma membrane enzyme activities. We found inhibition of Na+, K+ and Ca2+ ATP ases both in plasma and erythrocyte membrane fractions of CCl4 treated rats. CH/PL ratios of erythrocyte and plasma membrane fractions were also found significantly higher (p &lt; 0.001) than the control group. We observed significant negative correlations between the degree of cirrhosis and erythrocyte Na+, K+ and Ca2+ ATPase activities (p &lt; 0.0001). Our results suggest that measurement of erythrocyte membrane ATPase activities could be safe and useful marker of liver damage as transaminases that are currently used

The role of vitamin E in carbon tetrachloride toxicity

Recently, the relationship of nutrition/diet and pathogenesis of various diseases has been recognized. Investigators have made few studies on the nutrients that are essential for all fundamental cellular processess and their roles in modulating cellular oxidative damage and antioxidant defense. The aim of this investigation is to observe the antioxidant roles of vitamin E and selenium on CCl4-induced hepatotoxicity. Three groups of male Balbci mice were used in the experiments. The control group was fed a standard animal diet. The CCl4 group was treated with CC14 (1 mg/kg body weight) and the CCl4+ vitamin E group was given vitamin E (100 mg/kg) in addition to CCl4. After a period of 8 weeks determinations of selenium by atomic absorption spectrophotometry and vitmin E by HPLC were made in liver tissues of each three groups. A marked decrease in the values of selenium and vitamin E were noted in the group treated with CCl4. The results showed us that vitamin E had a protective effect on the hepatic cellular structure in CCl4 hepatotoxicity