Quantitative determination of epidermal G2-chalone-like factor by radial immunodiffusion

A homogeneous high-molecular-weight glycoprotein possessing tissue-specific, but not species-specific antimitotic activity relative to epithelium of dermal type (epidermal G₂-chalone) was isolated electrophoretically and immunochemically from rat skin. A method of quantitative immunodiffusion determination of this substance by means of monospecific antiserum in certain tissues is described. Clear correlation between the mitotic index and concentration of G₂-chalone in the mucous membrane at various stages of the estrous cycle was demonstrated in the vaginal epithelium.Laboratory of Experimental Tumors, Professor N. N. Petrov Research Institute of Oncology, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. I. Ioffe.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 7, pp. 114–116, July, 1979.     

Quantitative radial immunodiffusion assay for serum amyloid A protein

A radial immunodiffusion assay for serum amyloid A protein (SAA) using a commercially available antiserum is described. Serum is applied untreated to 1% agarose gels prepared in 0.02 M barbitone buffer, pH 8.6, containing 40 g/l polyethylene glycol 6000. Incubation is carried out overnight at 37 degrees C. The assay combines the advantages of simplicity, rapidity, specificity and stability, and avoids the hazards associated with the previously described radioimmunoassays. The method has sufficient sensitivity to measure SAA in the majority (99%) of normal subjects, and confirms the behaviour of SAA as a very sensitive acute phase reactant in inflammatory disease. The method is ideally suited to the rapid processing of a large number of samples.     

Evaluation of a radial immunodiffusion test with polysaccharide B antigen for diagnosis of bovine brucellosis.

A radial immunodiffusion (RID) test employing a polysaccharide antigen (poly B) was compared with tests currently used in the diagnosis of bovine brucellosis. Over 1,000 sera from vaccinated and infected cattle, all of which had been examined bacteriologically, were used to determine the sensitivity and specificity of the RID, card, Rivanol, and complement fixation tests. The RID test identified 90% of the cattle that were shedding Brucella in their milk. Although the complement fixation test was more sensitive, it was less specific than the RID test in cattle vaccinated as adults with Brucella abortus strain 19. A sensitive screening test, such as the card test, in combination with the RID test could be used in diagnostic laboratories, or even in the field, with little additional expense or technical expertise. An additional advantage is that the RID could be applied to sera from adult cattle as early as 2 months after vaccination, when postvaccinal agglutinins and complement-fixing antibodies may still be present. The indirect hemolytic test was used with some of the sera and was found to be a very sensitive test which could be useful in areas of low incidence but would not be practical for large-scale testing in adult-vaccinated herds.     

Detection of hepatitis B surface antigen by means of orcein staining of liver.

Paraffin-embedded sections of liver biopsies from 65 patients and 16 autopsies were stained by a modified orcein method as described by Shikata, to appraise the efficacy of the method in detecting hepatitis B antigen, (HGsAg). Of the liver biopsies from patients with chronic hepatitis, 55% were positively stained. Staining was observed in the cytoplasm of liver cells but was frequently irregular in distribution. The technic is simple and may be used for evaluation of fresh or stored liver. The positive stain is of value in the diagnosis of chronic hepatitis with minimal or absent histologic changes, as well as the distinction of chronic from acute hepatic disease. The method may be useful for detecting asymptomatic carriers. However, weak positive staining of hepatic parenchyma should be evaluated with caution when serologic tests for HBsAg are negative. It may warrant repeated serologic testing. Evaluation of stored autopsy material suggests that Shikata's stain may also be used in determining the etiology of cirrhosis. Inclusion bodies seen in hepatomas stain positively with orcein, suggesting that they contain, or are related to, HBsAg.     

Quantitative measurement of properdin in normal human serum by electroimmunoassay and single radial immunodiffusion.

Properdin in normal serum was measured by electroimmunoassay (EIA) and single radial immunodiffusion (SRID). Fresh sera gave much lower properdin values in SRID in gels containing Mg2+ ions. Storage of sera at 4 degrees C resulted in a gradual increase of the properdin values measured by SRID but not of those of the EIA. With 10 mM of EDTA in the gels no difference between the properdin values obtained by the different methods was found. Evidence is presented that immunodiffusion values of properdin might be affected by precipitation of a C3-properdin complex in gels containing Mg2+ ions after the activation of the properdin system by agarose.     

Quantitative detection of hepatitis B surface antigen by chemiluminescent microparticle immunoassay during lamivudine treatment of chronic hepatitis B virus carriers

The usefulness of fully automated chemiluminescent microparticle immunoassay (Architect HBsAg QT) for monitoring serum levels of hepatitis B virus (HBV) during antiviral therapy remains unclear. Using this assay, hepatitis B surface antigen (HBsAg) was measured in 20 patients with chronic hepatitis B before and during lamivudine treatment. At the start of therapy, 12 patients had detectable hepatitis B e antigen (HBeAg) and 8 did not. The median serum HBV DNA level and HBsAg concentration (25th-75th centile) were 7.2 (6.1-7.8) log genome equivalents/ml and 3,932 (1,585-12,330) IU/ml, respectively. The HBsAg concentration was significantly higher in HBeAg positive than in HBeAg negative patients (P=0.031). There was a significant correlation between the HBsAg concentration and HBV DNA level (r=0.490, P=0.027). The HBsAg concentration negatively correlated with patient age (r=-0.395, P=0.085). After the start of lamivudine therapy, HBV DNA levels fell rapidly in all patients. Serum HBsAg concentrations also fell in most patients, but to a lesser extent. When drug-resistant variants emerged, serum HBsAg usually increased before biochemical breakthrough. Although HBV DNA was elevated persistently after the emergence of drug-resistant variants, the increase in HBsAg was transient. In some patients, the increase in HBsAg preceded the increase in HBV DNA. Monitoring of serum HBsAg concentrations with the use of Architect HBsAg QT, in addition to measurement of HBV DNA levels, is helpful for evaluating the response to lamivudine treatment and for the early detection of drug-resistant strains.     

Quantitative analysis of hepatitis B surface antigen as a clinical marker

There are 1.5 million hepatitis B virus (HBV) infected patients in Japan. Anti-viral therapy is important for chronic hepatitis B patients to prevent hepatocellular carcinoma. Recently, HBs antigen (HBsAg) quantification has been reported to be useful for not only HBV screening but also for monitoring of anti-viral treatment. In this paper, we evaluated the clinical utility of quantitative assay of HBsAg by HISCL HBsAg kit. Although there can be a significant difference in age, HBeAg positive/negative and viral genotype, there is not in the disease stage. Moreover, the weak correlation was confirmed between HBsAg and HBV-DNA levels with or without anti-virus treatment. In the clinical practice, as HBV-DNA becomes undetectable immediately by anti-viral therapy such as entecavir, it may be difficult to evaluate the efficacy. The monitoring of the HBsAg concentration in addition to HBV-DNA would be useful for the evaluation. Hence, the clinical role of HBsAg concentration could spread widely in Japan.     

Determination of relative antigen-antibody avidities by radial immunodiffusion

Radial immunodiffusion can be used to determine relative antigen-antibody avidities in exactly the same way as demonstrated previously for quantitative immunoelectrophoresis (Birkmeyer et al., 1981). Antigen-antibody interactions of greater avidity result in a greater value of (delta Area/delta [Antigen]) in plots of immunoprecipitin circle area versus antigen concentration while interactions of equal avidity will yield equal values of (delta Area/delta [Antigen]). This was demonstrated using antigens of different weight ranging from 8000 to 66,000.     

Studies on single radial immunodiffusion techniques for the quantitation of antigen and antibody

A quantitative comparison has been made of various single radial immunodiffusion assays for the quantitation of antigen and antibody, using as a model system human IgG (HGG) as antigen and sheep anti-human IgG antibody.     

Diagnostic significance of quantitative determination of hepatitis B surface antigen in acute and chronic hepatitis B infection

HBsAg was determined quantitatively by radioimmunoassay and by Laurell electrophoresis in sera of 90 patients with acute hepatitis B, 57 patients with chronic hepatitis B, and 154 HBsAg positive blood donors. Of 55 patients with clearance of HBsAg from the circulation within six months, 54 (98 %) showed an at least 50 % reduction in concentration within 16 days. All 55 patients had such a decrease within 20 days. No such decrease was found in seven patients with acute hepatitis B who became HBsAg carriers. Therefore, quantitative HBsAg concentration in paired sera seems to be a reliable and early prognostic marker in acute hepatitis B. In patients with clearance of HBsAg most of the antigen is already present in the circulation at hospitalization and is eliminated with a mean half-life of 8.8 days. Patients with chronic hepatitis exhibit on average nearly the same HBsAg concentration (about 40,000 ng/ml) as patients with acute hepatitis B at hospitalization (about 39,000 ng/ml) and HBsAg positive blood donors on average a lower HBsAg concentration (about 8,000 ng/ml).     

Determination of kallidinogenase activity by radial immunodiffusion methods.

An attempt has been made to elaborate a method allowing determination of kallidinogenase obtained from the pancreas of slaughtered animals (pigs), by means of radial immunodiffusion method. As the test substance (antigen) a pharmaceutical preparation Dilminal D has been used. The immune serum against the preparation administered was obtained from rabbits. This serum was used to saturate plates of agar gel. Little pigs cut in the gel were filled with various concentrations of the preparation (antigen). A linear correlation between the selected concentrations of the preparation was obtained. This method may find application in determining preparations of kallidinogenase (from pig pancreas) with titer value given in different units.