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At least 19 recordsLinked to original sources
PubMed1975

Dynamics of the immune response in rabbits immunized with spreptococcal extracellular antigens: comparison of the Streptozyme agglutination test with three specific neutralization tests.

The dynamics of the immune response to streptococcal extracellular antigens as measured by the streptozyme agglutination test have been defined in experimental animals andcompared with the dynamics of the immune response as determined by three established neutralization tests for streptococcal antibodies (ASO, anti-DNase B,and anti-NADase). In rabbits immunized with streptococcal extracellular Streptozyme-measured antibodies rose more quickly and peaked earlier than did antibodies to streptolysin O, streptococcal DNase-B, and streptococcal NADase. Additional studiesrevealed that the early peak was primarily due to 2-mercaptoethanol-sensitive (19S) antibody and that the later rise in Streptozyme-measured antibodies was due to 2-mercaptoethanol-resistant (7S) antibody. Preliminary observations using sucrose gradient ultracentrifugation tended to confirm this interpretation. These data provide a possible explanation for the early detection of a streptococcal antibody response by the Streptozyme test which has also been described in humans. The data suggest a theoretical advantage for the Streptozyme agglutination test in patients with streptococcal infections and their sequealae. However, the complexity of the Streptozyme reagent suggests that more extensive studies are needed to assure the consistent reproductivity of results with different lots of the test reagent.

Agglutination Tests↗
PubMed1978

Vero microcultures for adenovirus neutralization tests.

A microculture neutralization test is described for measuring specific antibody levels to the 35 human adenovirus serotypes in Vero cells. The test is read at 5 days by macroscopic observation after staining the uninfected cells with crystal violet. The test is performed with a minimum of manipulations and gives serum titers comparable with those obtained in tube macrocultures of monkey kidney, human embryonic kidney, and Vero cells. The Vero microculture neutralization test measures inhibition of adenovirus toxicity, although selected human adenoviruses serially subpassaged in Vero cells were shown to successfully adapt and replicate in the absence of detectable helper viruses.

Adenoviruses, Human↗
PubMed1979

Sensitive neutralization test for rubella antibody.

A modified rubella virus plaque neutralization test for measuring rubella antibody was developed based on the potentiation of the virus-antibody complex by heterologous anti-immunoglobulin. The test is highly sensitive, yielding titers on the average 50 to 100 times higher than the haemagglutination inhibition test or the conventional plaque neutralization test. The sensitivity of this enhanced neutralization test is somewhat limited by the existence of a prozone phenomenon which precludes testing of low-titered sera below a dilution of 1:16. No prozone effect was observed with cerebrospinal fluids. The specificity of the enhanced neutralization test was determined by seroconversion of individuals receiving rubella vaccine. Although the rubella hemagglutination inhibition test remains the test of choice in routine diagnostic and surveillance work, the enhanced rubella neutralization test is particularly useful in monitoring low-level antibody in the cerebrospinal fluid in patients with neurological disorders and in certain instances of vaccine failure.

Adolescent↗
PubMed1976

Transmissible gastroenteritis virus: plaques and a plaque neutralization test.

A plaquing system and plaque neutralization test in porcine thyroid cells were used to study different transmissible gastroenteritis isolates and hemagglutinating encephalomyelitis virus. Among transmissible gastroenteritis virus isolates, plaque size varied considerably and mixed size ranges sometimes occurred. The most recently isolated viruses produced smaller plaques than the laboratory viruses or hemagglutinating encephalomyelitis virus. All transmissible gastroenteritis virus isolates reacted in the plaque neutralization test with a transmissible gastroenteritis virus antiserum which showed no activity against hemagglutinating encephalomyelitis virus. Plaque neutralization results both from experimentally infected pigs and following a field outbreak demonstrated the reliability of this test and its greater sensitivity than the conventional tube test.

Animals↗
PubMed1976

Plaque reduction neutralization test for human cytomegalovirus based upon enhanced uptake of neutral red by virus-infected cells.

Foci of cells infected with human cytomegalovirus were noted to stain more intensely than uninfected cells with neutral red, and this provided the basis for development of a plaque assay and plaque reduction neutralization test for cytomegalovirus. Plaques demonstrable by neutral red staining could be counted at 8 days after infection; thus, results could be obtained earlier than for plaque assay systems based upon the viral cytopathic effect, a fewer manipulations were required for staining cell monolayers to demonstrate plaques. Certain variables affecting plaque size and numbers and antibody titers were defined. Addition of fresh guinea pig complement to the reaction mixtures markedly enhanced cytomegalovirus-neutralizing antibody titers of hyperimmune animal sera, but titers of human sera were enhanced only two-or fourfold.

Animals↗
PubMed1976

Serum dilution neutralization test for California group virus identification and serology.

The serum dilution neutralization test was evaluated for serological diagnosis of California group arbovirus infections and identification of virus isolates. The technical advantages and the degree of subtype specificity of the serum dilution neutralization test over the hemagglutination inhibition test and the complement fixation test were demonstrated with paired specimens from human cases, single human survey sera, and sentinel rabbit sera. Twenty-one virus isolates from various geographical areas of the United States were also used to evaluate the efficacy of the serum dilution neutralization test for specific virus identification.

Adolescent↗
PubMed1978

Sensitive neutralization test for virus antibody. 1. Mumps antibody.

A sensitive mumps virus plaque neutralization test has been developed based on the potentiation of virus-antibody complexes by heterologous anti-immunoglobulins (AIG). The enhanced neutralization test was approximately 100 times more sensitive than the conventional neutralization test or the hemagglutination-inhibition test. Using AIG against human immunoglobulin G (IgG) or human IgM permitted determination of the relative titers of the two classes of mumps antibody. The test does not require special equipment or expertise and can be readily introduced in virological laboratories.

Antibodies, Anti-Idiotypic↗
PubMed1979

A vesicular stomatitis virus (cytomegalovirus) pseudotype and its use in neutralization tests.

Infection with vesicular stomatitis virus (VSV) of human diploid cells preinfected with the AD-169 strain of human cytomegalovirus (CMV) resulted in the formation of a VSV (CMV) pseudotype. Its formation was favored by increasing the bicarbonate content in doubly-infected cultures. The pseudotype was capable of infecting not only human but also rabbit cells. Pseudotype particles formed after infection with the tl 17 mutant of VSV, which carries a thermolabile lesion in its neutralization antigen, were more stable at 45 degrees than the original tl 17 virus. The pseudotype was used in the neutralization test with human sera. All sera positive for CMV antibody in the complement-fixation (CF) test were also reactive in the neutralization test. In addition, numerous sera negative for CMV antibody in the CF test neutralized the pseudotype.

Adult↗
PubMed1991

Comparative evaluation of an enzyme-linked immunosorbent assay (ELISA) to detect antibodies directed against glycoprotein I of pseudorabies virus and a conventional ELISA and neutralization tests.

To determine whether a newly developed enzyme-linked immunosorbent assay (ELISA), which detects antibodies directed against glycoprotein I (gI) of pseudorabies virus, is suitable for serodiagnosis, it was compared with a conventional ELISA and two neutralization tests. The gI ELISA was 99.2% as sensitive and 100% as specific as the conventional ELISA. Antibody titers measured by the gI ELISA were lower than those measured by the conventional ELISA, comparable to those measured by the 24-h neutralization test, and higher than those measured by the 1-h neutralization test. After experimental infections in pigs, antibodies were first detected by the gI ELISA on postinoculation day (PID) 14, by both neutralization tests on PID 7, and by the ELISA on PID 10. All four tests showed the same rate of decline of maternal antibodies in pigs born to sows that had been vaccinated with inactivated vaccine. Thus, not only is the gI ELISA unique in being able to differentiate infected pigs from those vaccinated with gI-negative vaccines, but it is also as useful as a conventional ELISA and as neutralization tests for serodiagnosis.

Animals↗
PubMed1991

Comparison of European isolates of viruses causing hemorrhagic fever with renal syndrome by a neutralization test.

Different virus isolates causing hemorrhagic fever with renal syndrome (HFRS) were compared using a neutralization test. Patient convalescent sera and antisera prepared in rabbits were used to compare Puumala-related Hantavirus isolates from Finland, Sweden, Belgium, and the USSR. The majority of European isolates were indistinguishable from each other using both homologous rabbit antisera and patient convalescent sera. The European isolates of HFRS were also compared with prototype Hantaan (the etiologic agent of Korean hemorrhagic fever). The one-way cross-reaction between the Hantaan and Puumala viruses, previously described using human convalescent sera tested by indirect immunofluorescence and immunoprecipitation, was also seen by the neutralization test.

Europe↗
PubMed1978

[Detection of antibodies to Rickketsia prowazekii by using the antigen neutralization test].

The authors studied a possibility of using the antigen neutralization test with dry immunoglobulin typhus erythrocytic diagnostic agent for the purpose of detection of Rickettsia prowazeki antibodies. Blood sera of 315 healthy persons, 24 patients with sporadic typhus, and 18 laboratory animals immunized with R. sibirica and R. burneti, as well as with Proteus OX19 were examined. The results obtained pointed to the high specificity and sensitivity of the given serological test. A possibility of its use for antibody detection both in the typhus patients and in persons who sustained this infection in the past was demonstrated. In difference from the complement fixation test it permits to study anticomplementary sera.

Antibodies, Bacterial↗
PubMed1979

A rapid plaque neutralization test for bluetongue virus.

A bluetongue virus plaque neutralization test, done in small tissue culture wells (2.0 cm2) using minimal antibody-virus contact time, was found to be of comparable sensitivity to more classical methods involving preincubation. By using the cell culture plates as serum dilution wells and adding cells directly to the virus-antibody mixture, a considerable saving in time is realized. Because of the small size of the wells, reagent cost and incubator space requirements are reduced making the test much more attractive for wide scale use, either as a screening test or one that yields dose-response lines.

Animals↗
PubMed1979

Immunity to a 3-methylcholanthrene-induced fibrosarcoma in the C57BL/6 mouse: in vivo analysis by the adoptive tumor neutralization test.

Analyses of the adoptive tumor neutralization test (modified Winn test) in C57BL/6 mice made immune to a 3-methylcholantheene-induced fibrosarcoma showed that the reaction was mediated by a thymus-derived lymphocyte, it was tumor-specific, and the resistance of the immunized donor mouse to the challenge was strongly correlated with the protection of the recipient mouse. Proliferation of immune cells and close contact between tumor cells and immune T-cells were required. The hypothesis of a participation of the recipient in the reaction was considered because of the lack of adoptive protection of pangenic nude mice.

Animals↗
PubMed1976

Hemolysis-in-gel and neutralization tests for determination of antibodies to mumps virus.

A hemolysis-in-gel test for the demonstration of antibodies to mumps virus is described. The results were compared with those of neutralization tests using a modified microtechnique. In the neutralization test viral replication was demonstrated by the hemadsorption of guinea pig erythrocytes, the visibility of which could be further enhanced by the use of o-tolidine. Good correlation was found between the results of the two techniques. The hemolysis-in-gel test was simple to perform, rapid, sensitive, and shown to be a useful test for the demonstration of mumps antibodies.

Antibodies, Viral↗
PubMed1976

[Use of the neutralization test for mass population studies].

The authors applied the antibody neutralization test (ANT) for detection of causative agent of intestinal infections in feces of healthy population in Turkmenia. Some part of the material was studied in parallel with the aid of the ANT and by the bacteriological method. As a result of comparison it appeared that in using the ANT causative agents of intestinal infections were revealed much more frequently than by the bacteriological method; in this connection this serological method can be recommended as an auxiliary one for the diagnosis of intestinal infections.

Diagnosis, Differential↗
PubMedDate not supplied

[Study of the correlation between neutralization tests and hemagglutination inhibition tests in determinations of mumps virus antibodies].

In order to find out possibilities of wide application of the hemagglutination-inhibition (HI) test for determination of antibody to mumps virus, correlations between neutralization test (NT) and HI test was studied. Antibody to mumps virus was detected by parallel titrations of sera and gamma globulins in HI and NT tests in two experimental series each of which used various modifications of these tests. Statistically significant strong correlation was established between these tests.

Antibodies, Viral↗