PubMed HealthSearch

Biomedical subjects

W Gerlich

Publications and source records attributed to W Gerlich.

26 records · Page 2Linked to original sources

[Separation of morphological types of hepatitis B-antigen (author's transl)].

Hepatitis B Antigen from plasma of a healthy chronic carrier was separated by gel chromatography using 6% agarose gel into fractions with different size (Fig. 1). Single fractions were further purified by isopycnic centrifugation in CsCl (Fig. 2) and characterized by electron microscopy (Fig. 3). The amount of the different particle groups was determined comparing the extinction peaks in the centrifugates (Table 1). 88% of antigen protein was located in the 18 to 25 nm spheres (Fig. 3a), 10% in tubules with a length between 30 and 100 nm and about 2% form tubules 100-200 nm long (Fig. 3b and 3c). Together with the tubules were found 40 nm spheres representing about 0,1% of the HBAg-substance (Dane paticles, Fig. 3d). The proportion of the larger antigen particle seems to be absent or very low in acute Hepatitis B patients, but is frequently found in chronic carriers.

Carrier State

Standardized detection of hepatitis B surface antigen: determination of its serum concentration in weight units per volume.

The concentration of HBsAg in serum was determined in arbitrary units by quantitative immunoelectrophoresis and in units of optical density by UV-photometry of purified antigen. The HBsAg was purified from serum by gelchromatography and subsequently by isopycnic centrifugation in cesium chloride. The ratio of the immunoelectrophoretically measured concentration to the units of optical density was found to be constant in six different samples with both subtypes - ad and ay - and varying concentration. The concentration of protein in three purified HBsAg samples was determined after acid hydrolysis by automatic aminoacid analysis. The specific extinction was E1 280 mg/ml = 4,5 +/- 0,3. Thus the arbitrary units of immunoelectrophoresis were converted to concentration of HBsAg specific protein, expressed as mug/ml. In 540 Ausria positive serum samples, mainly from the beginning of an acute hepatitis, 10-40 mug/ml was the most frequent range of concentration. About 4% of the sera contained more than 100 mug/ml, about 20% contained between 0,005 and 0,5 mug/ml and were positive only in RIA. 10 mug/ml correlated with titers in complement fixation of 1:32/64, in counterimmunoelectrophoresis of 1:8 and immuno-diffusion of 1:2. The use of standards with a defined concentration of HBsAg would allow a better control of the sensitivity in qualitative tests and of reproducibility in quantitation.

Animals

The effect of recombinant alpha-interferon treatment on serum levels of hepatitis B virus-encoded proteins in man.

The effect of alpha-interferon treatment on serum levels of hepatitis B virus-encoded proteins was analyzed in eight patients with chronic type B hepatitis who participated in a pilot study of interferon therapy. Three individuals became HBsAg-negative, 4 lost HBeAg but remained HBsAg-positive and 1 remained positive for both HBsAg and HBeAg. Initiation of interferon treatment was rapidly followed by reduction or loss of hepatitis B virus DNA in the serum but by little immediate change in hepatitis B virus antigen levels. Changes in hepatitis B virus antigens were usually delayed. Loss of HBsAg from the serum was preceded by the sequential disappearance of pre-S-encoded proteins (pre-S1 and polymerized human serum albumin) and HBeAg. In patients who lost HBeAg but remained HBsAg-positive, serum levels of pre-S1 and polymerized human serum albumin usually, but did not always, decrease. The individual who remained HBsAg- and HBeAg-positive had unchanged serum levels of pre-S1, polymerized human serum albumin and HBsAg. These results suggest that alpha-interferon inhibits hepatitis B virus DNA replication but has little direct effect on synthesis of hepatitis B virus gene products.

Adult