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Biomedical subjects

W Gerlich

Publications and source records attributed to W Gerlich.

At least 37 records · Page 2Linked to original sources
PubMed1979

Detection of antibodies to Sendai virus by enzyme-linked immunosorbent assay (ELISA).

An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Sendai virus, a paramyxovirus, is described. The assay was found to be about 20-fold more sensitive than the hemagglutination inhibition assay. Differentiation between virus specific IgG and IgM is possible. The test appears to be especially useful in the study of early events in antibody formation in vivo as well as in vitro.

Animals↗
PubMed1979

Antibody-dependent cell-mediated cytotoxicity (ADCC) and cell-mediated cytotoxicity (CMC) to HBsAg-coated target cells in patients with hepatitis B and chronic hepatitis (CAH).

A new technique using HBsAg-coated Chang cells as target cells was developed in order to measure cell-mediated immune reactions to HBsAg. The specificity of cytotoxic reactions was tested in experiments using Chang cells conjugated with human serum albumin. Antibody-dependent cell-mediated cytotoxicity (ADCC) specific for the HBsAg-coated target cells was demonstrated up to dilutions of anti-HBsAg serum of 10,000 : 1, when lymphocytes from the peripheral blood of normal individuals were added to the target cells. Spontaneous cell-mediated cytotoxicity (CMC) to HBsAg-coated target cells was demonstrated for lymphocytes from patients with hepatitis B and from patients with chronic active hepatitis (CAH), but not for lymphocytes from healthy controls. The CMC of hepatitis B lymphocytes to HBsAg-coated target cells was inhibited in the presence of antiserum to HBsAg. In experiments using purified lymphocyte populations evidence is presented that the CMC is T-cell dependent. HLA-restriction of the CMC was not observed. The described cytotoxicity test system has the advantage that target cells conjugated with defined antigens are used and that relevant control target cells are available.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1979

[Studies on the serological manifestation of the hepatitis B-virus-infections in the Republic of Liberia (author's transl)].

The prevalence of hepatitis B virus infections was examined in four groups from Liberia using radioimmunoassays for HBsAg, anti-HBs and anti-HBc. At the age of 15-19 years 90% have been infected, at the age of 40 years 100%. In a rubber plantation 30% had HBsAg, in the remaining 3 groups only 13% were HBsAg-positive. In the first group onchocerciasis was also a more frequent finding. However the parasitic infection was not the cause of the HBs-antigenemia. The HBsAg-concentration is mostly lower in the positive Liberians than in German HBsAg-carriers. Apparently the HBV caused frequently latent infections with low production of viral antigens in Liberia.

Adolescent↗
PubMed1978

[Asymptomatic chronic-persisting hepatitis B in a young child as source of infection of hepatitis B within a family (author's transl)].

Five members of an eight-member family fell ill with an acute icteric hepatitis B of the same subtype within eleven months. In all probability the source of the infection was a just over one-year-old fostered child with asymptomatic chronic persisting hepatitis B and signs of massive viraemia (usually high HBs antigen concentration, high virus-specific DNA-polymerase activity and positive HBe antigen test). No relation could be demonstrated between HLA constellation and illness in the family members. Since no specific treatment is available, the only possible prophylactic measure is to isolate the child in the present environment, to avoid further cases of the disease.

Acute Disease↗
PubMed1978

The seroepidemiological pattern of acute viral hepatitis. An epidemiological study on viral hepatitis in the Hannover region.

The natural incidence of the etiologically distinct types of viral hepatitis was determined by investigating acute phase sera of symptomatic hepatitis cases occuring in the Hannover area in 1975 for the presence of hepatitis B surface antigen, antibodies to hepatitis A, hepatitis B core and surface antigens, and by measuring the IgM serum levels. Fourteen different seroepidemiologic patterns were recognized. Although there was a high prevalence of hepatitis A antibody in the population, the frequency of hepatitis A was low (n = 56) suggesting that the hepatitis A virus does not play a major role in symptomatic hepatitis in the Hannover area at present. Spread of the hepatitis A virus was mostly associated with person-to-person contact or tourist travel in southern Europe. Hepatitis B was the predominant type of hepatitis (n = 211). Hepatitis non-A, non-B was observed infrequently (n = 62). A high percentage of patients with hepatitis B and hepatitis non-A, non-B reported parenteral exposure to potentially contaminated materials. No other findings, however, suggested an infectious etiology of hepatitis non-A, non-B.

Antibodies, Viral↗
PubMed1978

[Differing results of direct and indirect solid phase radioimmunoassay for HBsAg in acute hepatitis (author's transl)].

In 54 patients suffering from acute viral hepatitis the indirect solid phase radioimmunoassay (ind-SPRIA) for HBsAg was positive in 9 cases the direct solid phase radioimmunoassay (d-SPRIA) being negative. In 2 further cases ind-SPRIA was positive during several weeks but d-SPRIA only once. AntiHBc could be detected in 9 of these patients. In 7 patients the usual decrease of the transaminase activity was followed by a second elevation with prolongation of disease. The unknown factor detected by ind-SPRIA suggests a special form of acute hepatitis.

Adult↗
PubMed1977

Radioimmunoassay for LCM virus antigens and anti-LCM virus antibodies and its application in an epidemiologic survey of people exposed to syrian hamsters.

A specific and sensitive solid-phase radioimmunoassay has been developed for the detection of LCM virus antigens and anti-LCM virus antibodies. The test was performed in a microtiter system using polyvinylcholoride wells coated with anti-LCM virus rabbit hyperimmune serum. LCM virus antigens were allowed to bind to this antibody and afterwards detected by 125J-labeled anti-LCM virus-gamma-globulin. Anti-LCM virus antibodies were assayed by specific inhibition of these bound antigens. Since this technique is rapid and easy to perform the solid-phase radioimmunoassay is a valuable test for detecting LCM virus infections. Selected at random, 208 girls with, and 208 girls without, contact to Syrian hamsters were investigated for anti-LCM virus antibodies. Five (2.4%) of the hamster-exposed girls had anti-LCM virus antibodies (RIA-titer 1:8-1:32) in contrast to none of the control group (P=0.03).

Animals↗
PubMed1975

[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↗
PubMed1975

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↗