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At least 793 records · Page 44Linked to original sources
PubMed1984

[Use of monoclonal antibodies in immunoenzyme analysis for demonstrating antigenic monovalency].

To prove the monovalence of the antigen a method has been developed consisting of ELISA with the use of monoclonal antibodies in combination with the antibody neutralization test. Yersinia pestis capsular antigen was disintegrated by heating at 100 degrees C for a short time and subsequently passed through a column packed with Sephadex G-50. The portions of the eluate, showing high activity in the antibody neutralization test and low activity in ELISA (the double antibody sandwich scheme), contained mainly the monovalent antigen. This antigen was replaced by the polyvalent antigen from the antibody complex, but if such complex had been previously fixed by treatment with glutaraldehyde, no replacement of the monovalent antigen by the polyvalent one occurred.

Animals↗
PubMed2004

Antigenicity of two turkey astrovirus isolates.

Astroviruses are positive-sense single-stranded RNA viruses. These viruses cause gastroenteritis in humans and in a variety of animal species, including turkey poults. Only human astroviruses are well characterized antigenically. In the current study, two turkey astrovirus isolates, TAstV1987 and TAstV2001, were antigenically compared using cross-neutralization tests in turkey embryos, as well as cross-reactivity of the two isolates by an enzyme-linked immunosorbent assay (ELISA). The antigenic relatedness values (R) were calculated using the Archetti and Horsfall formula. The R value based on the cross-neutralization tests was 0.56%, which indicates that TAstV1987 and TAstV2001 belong to different serotypes; the R value of the two viruses based on ELISA was 70.7%, which suggests these two viruses share common antigen(s).

Animals↗
PubMedDate not supplied

[Detection of rabies virus antibodies in human blood serum by an immunoenzyme method].

In a coded experiment on rabies virus antibody detection in the blood sera of humans immunized with rabies vaccines, coincidence of the results of indirect ELISA, neutralization test and radial hemolysis test (RHT) was observed in 83% and 90% of the cases. The correlation coefficient of antibody titres in ELISA and NT was r = +0.75, ELISA and RHT r = +0.81. Instances of discrepancy of the results were observed with sera of low titres, no more than 1:50 by neutralization test.

Animals↗
PubMed1971

Comparison of microtiter procedures with the plaque technique for assay of vesicular stomatitis virus.

This paper describes a microprocedure for the tissue culture assay of vesicular stomatitis virus (VSV) and compares the sensitivity of the method with the conventional plaque assay of viral concentration. Microtiter and plaque assay methods were used in titrations, neutralization tests, and thermoinactivation studies with this virus in chick embryo fibroblasts (CEF) and L, HeLa, and PK cell lines. Titration experiments with VSV by the microtiter procedure on preformed monolayers were significantly more sensitive than the plaque assay (P = 0.05). The results of the neutralization tests and thermoinactivation studies also showed greater ability to detect residual virus by the microtiter procedure (P = 0.10). In addition, the microtiter procedure was simpler, less costly, and more rapid than the plaque assay.

Analysis of Variance↗
PubMed1978

Serotyping herpes simplex virus isolated by enzyme-linked immunosorbent assays.

An enzyme-linked immunosorbent assay (ELISA) using a double-antibody sandwich tecnhique has been developed to serotype isolates of herpes simplex virus from clinical sources. The results obtained using this procedure were in agreement with those obtained with a standard neutralization test in typing stock cultures and 32 clinical isolates of herpes simplex virus. Clear differentiation between the two viral serotypes was obtained using rabbit immunoglobulin cross-absorbed with heterologous virus antigen. The ELISA procedure described appears to be a convenient and accurate substitute for the neutralization test in typing herpes simplex viruses. ELISA techniques require relatively small amounts of antigen and antibody and can be performed with very simple equipment.

Enzyme-Linked Immunosorbent Assay↗
PubMed2003

Serologic survey of domestic animals for zoonotic arbovirus infections in the Lacandón Forest region of Chiapas, Mexico.

A serologic survey in domestic animals (birds and mammals) was conducted in four communities located in the Lacandón Forest region of northeastern Chiapas, Mexico, during June 29 to July 1, 2001, with the objective to identify zoonotic arboviruses circulating in this area. We collected 202 serum samples from healthy domestic chickens, geese, ducks, turkeys, horses and cattle. The samples were tested by plaque-reduction neutralization test for antibodies to selected mosquito-borne flaviviruses (family Flaviviridae), including St. Louis encephalitis (SLE), Rocio (ROC), Ilheus (ILH), Bussuquara (BSQ), and West Nile (WN) viruses, and selected alphaviruses (family Togaviridae), including Western equine encephalitis (WEE), Eastern equine encephalomyelitis (EEE), and Venezuelan equine encephalitis (VEE) viruses. Neutralizing antibodies to SLE virus were detected in two (8%) of 26 turkeys, 15 (23%) of 66 cattle, and three (60%) of five horses. Antibodies to VEE virus were detected in 29 (45%) of 65 cattle. Because some of these animals were as young as 2 months old, we demonstrated recent activity of these two viruses. Sub-typing of the VEE antibody responses indicated that the etiologic agents of these infections belonged to the IE variety of VEE, which has been reported from other regions of Chiapas. WN virus-neutralizing antibodies were detected in a single cattle specimen (PRNT(90) = 1:80) that also circulated SLE virus-neutralizing antibodies (PRNT(90) = 1:20), suggesting that WN virus may have been introduced into the region. We also detected weak neutralizing activity to BSQ virus in four cattle and a chicken specimen, suggesting the presence of this or a closely related virus in Mexico. There was no evidence for transmission of the other viruses (ROC, ILH, EEE, WEE) in the study area.

Animals↗
PubMed1995

Boosting immune response with a candidate varicella-zoster virus glycoprotein subunit vaccine.

A varicella-zoster virus (VZV) seropositive individual was immunized with 100 micrograms of purified VZV TgpI-511 glycoprotein subunit antigen formulated with monophosphoryl lipid A. Serum samples were obtained during a 40-day period post-immunization (PI) and analysed by immunoprecipitation and virus neutralization tests. The results from immunoprecipitation studies revealed an increase in VZV anti-gpI antibody titer as early as 6 days PI which continued to rise during 40 days PI. In addition, virus neutralization tests showed a 21.0% VZV neutralization 6 days PI with an increase to a 96.7% VZV neutralization 40 days PI. These results suggested that the candidate VZV glycoprotein subunit vaccine (TgpI-511) was capable of boosting the production of neutralizing antibodies in the immunized VZV seropositive human subject.

Antibodies, Viral↗
PubMed1996

Differences between original strains and their mouse-adapted variants of human (H1) and avian (H2) influenza A viruses in the reaction with cross-neutralizing monoclonal antibody recognizing conformational epitope.

Human (H1) and avian (H2) influenza A viruses and their mouse-adapted (MA) variants were studied in radioimmunoprecipitation assay (RIPA) and infectivity neutralization test using a monoclonal antibody (MoAb) directed against a conserved antigenic epitope in the stem region of the haemagglutinin (HA) and reacting both with H1 and H2 subtypes of HA. Whereas the MA variant of avian influenza A virus differed from the original strain in RIPA and neutralization tests, no differences were observed between the original human strain and its MA variant, as well as between the original H1 and H2 strains.

Adaptation, Physiological↗
PubMed1984

The effect of antiserum quality on strain specificity assessment of foot and mouth disease virus by the neutralization reaction.

The factors affecting the virus strain specificity of antibody to foot an mouth disease virus prepared by a variety of protocols in several species were evaluated by neutralization tests. The time at which the serum was taken, the antigen dose given, whether or not revaccination had occurred and the animal species in which the sera were prepared, did not appear to affect the strain specificity of serum prepared to inactivated antigens when measured in neutralization tests, probably because of the restricted nature of the antigenic site involved. However, variation was observed with convalescent animal sera or sera from animals which had received trypsin cleaved virus were used. For these reasons banks of reference antisera are prepared as pooled sera using one or two inoculations of inactivated antigen.

Animals↗
PubMed2001

Cytotoxicity of dental glass ionomers evaluated using dimethylthiazol diphenyltetrazolium and neutral red tests.

The purpose of this study was to assess the cytotoxicity of some commonly used glass ionomers. Three chemically cured glass ionomers (Fuji II, Lining cement, and Ketac Silver) and one light-cured (Fuji II LC) were tested. Extracts of mixed non-polymerized materials and polymerized specimens were prepared in accordance with ISO standard 10993-12. The polymerized specimens were cured and placed either directly in the medium (freshly cured), left for 24 h (aged), or aged plus ground before being placed in the medium. The cytotoxicity of extracts was evaluated on mouse fibroblasts (L, 929), using dimethylthiazol diphenyltetrazolium (MTT) and neutral red (NR) assays. Further, the concentrations of aluminum, arsenic and lead were analyzed in aqueous extracts from freshly cured and aged samples, and the fluoride levels analyzed in aqueous extracts from freshly cured samples. All extracts except that of non-polymerized Ketac Silver were rated as severely cytotoxic in both assays. Extracts of polymerized material were significantly more cytotoxic than extracts of non-polymerized material. All freshly cured glass ionomers released aluminum and fluoride concentrations far above what is considered cytotoxic (aluminum >0.2 ppm and fluoride >20 ppm). Extracts from freshly cured Lining Cement contained the highest concentrations of aluminum and fluoride (215 ppm and 112 ppm). Extracts from freshly cured Ketac Silver had the lowest concentrations of aluminum and fluoride but the highest of lead (100 ppm). It can be concluded that all extracts from non-cured, freshly cured, and aged glass ionomers contained cytotoxic levels of substances. Curing did not reduce the toxicity significantly.

Aluminum↗
PubMed1977

Occurrence of cross reactions to foot-and-mouth disease virus in normal swine sera.

Sera from 101 swine never exposed to foot-and-mouth disease virus were tested by the plaque-reduction neutralization (PRN) and radial immunodiffusion techniques for cross-reactions to 5 types of foot-and-mouth disease viruses. Depending on the group of sera and the virus used, the percentage of sera cross-reacting at low levels varied from 0 to 50% with the PRN technique and 0 to 20% with the radial immunodiffusion technique. 5erum-neutralization tests in mice support the finding of neutralizing antibody by the PRN technique. Ultracentrifugation and 2-mercaptoethanol studies indicate that the cross-reactions are the result of immunoglobulin M or similar macroglobulins.

Animals↗
PubMed1994

[Antigenic determination of human anti-rabies vaccine against viral street strains common in the wild animal population in Poland].

The aim of the study was to compare the antigen properties of a vaccine strain with street strains isolated from various animal hosts throughout the country. Investigation was carried out using monoclonal antibodies against NC protein. Also, two tests were carried out: the modified NIH test for potency and the neutralization test using the sera of people vaccinated against rabies (PM vaccine strain). The investigated street strains were used in both tests as the challenge viruses. A suspension of these strains diluted five times made it possible to avoid extreme values of animal survival (0% or 100%) what, consequently, made calculation of the LD50 value easier. A different rabies virus serotype (EBLI virus) in the population of insectivore bats Eptesicus serotinus and antigen variants within the first serotype, having common epitopes with strains of the vaccine virus SAD B19 and the polar rabies virus, were found to be present throughout the country. The concentrated and purified vaccine containing the PM virus did not protect mice against infection with strains of viruses isolated from bats (protection index 10 and lower). For the remaining strains, depending on the animal source of their isolation, the protection index ranged from 10 to 1000 and higher. The properties neutralizing a dose of 5 i.u./ml of serum from the subject inoculated with the vaccine containing the PM strain were similar for all the investigated strains; 0,5 i.u./ml did not neutralize the strain isolated from a racoon dog.

Animals↗
PubMed2003

Cytotoxicity of liquids and powders of chemically different dental materials evaluated using dimethylthiazol diphenyltetrazolium and neutral red tests.

The purpose of this study was to assess and compare the cytotoxicity of liquid and powder components of chemically different dental materials using 2 basic unspecific cell culture methods. Three chemically cured glass ionomers (Fuji II, Lining cement, and Ketac Silver), 1 light-cured glass ionomer (Fuji II LC), and 2 chemically cured acrylates (Swedon and Super Bond) were tested. The liquids were diluted 1:10 in cell culture medium. The liquids from chemically cured acrylates were further diluted 1:100, 1:1000, and 1:10000. Extracts were made by incubating the powders in cell culture medium for 24 h at 37 degrees C according to the ISO standard 10993-12. The cytotoxicity was assessed in transformed mouse fibroblasts (L-929) using two viability assays, dimethylthiazol diphenyltetrazolium (MTT) and neutral red (NR). Severe cytotoxicity was observed when testing powder extracts of Swedon, Fuji II, and Lining cement, whereas powder extracts of Ketac Silver, Fuji LC, and Super Bond induced slight to non-cytotoxicity. All of the 1:10 liquid dilutions were severely cytotoxic in the MTT assay. In the NR assay, however, four 10% dilutions were severely cytotoxic and 4 moderately cytotoxic. Further dilution of the liquids of the chemically cured acrylates reduced the toxicity, while the Super Bond catalyst was severely cytotoxic even as the 1:100 dilutions.

Animals↗
PubMed1990

Incidence of sand fly fever among Swedish United Nations soldiers on Cyprus during 1985.

Members of a Swedish United Nations (UN) battalion of 362 soldiers were bled just before and immediately after their 6 month tour of duty in Cyprus during 1985. Sera were tested for presence of specific antibodies to sand fly fever (SF) Sicilian, SF Naples, and Toscana viruses by both indirect immunofluorescence antibody test (IFT) and plaque reduction neutralization test (PRNT). Of 298 serum pairs available, seroconversion was noted in 11 soldiers: 7 cases for SF Sicilian, 3 for SF Naples, and 1 for Toscana virus. IFT and PRNT revealed identical results. Seroconversion was associated with clinical disease in 7 out of 7, 2 out of 3, and 0 out of 1 for SF Sicilian, SF Naples, and Toscana infections, respectively. Virus isolation was attempted on acute-phase sera collected from febrile patients. Of 5 such acute-phase sera from patients with serologically verified SF, virus was recovered from 2: 1 strain of SF Sicilian virus and 1 strain of SF Naples virus.

Adult↗
PubMed1979

[Rabies specific IgM- and IgG-antibody response in persons immunized with HDCS vaccine according to the Essen postexposure vaccination schedule (author's transl)].

A solid phase enzyme immunoassay (ELISA) was applied for the determination of rabies virus antibodies of the immunoglobulin classes G and M in sera of 10 young adults. Vaccinations were carried out with the Essen post-exposure vaccination schedule, which is recommended by the W.H.O., with the rabies HDCS vaccine with an antigen value of 1.9. From these results the rabies virus IgM/IgG-conversion was derived. Furthermore a comparison was carried out of results obtained with the ELISA, the mouse neutralization test, the complement fixation test and the hemagglutination inhibition test. Rabies virus-IgM-antibodies were detected already three days after the first vaccination. The IgM-antibody concentration increased to a maximum at the 22nd day p.v. In sera of seven of eight vaccinees rabies virus IgM-antibody was still detectable until the 90th day p.v. Rabies virus antibodies of the IgG-class were found in the serum of 1/7 vaccinees at the 7th day p.v. A steep increase of the rabies virus IgG-antibodies was observed from day 10 p.v. to a maximum between the 30th and 40th day p.v.. The titer values varied between 1:10-1:1600. The rabies virus IgM/IgG-conversion was observed after the 10th day p.v.. More than 75% of the total antirabies virus globulin fraction belonged to the IgG-class in sera of 6 of 9 vaccinees between the 22nd and 30th day of p.v.. A preponderance of the rabies virus IgM-antibodies was seen in 3 of 9 vaccinees until the 90th day p.v.. Most sensitive for the early detection of rabies virus antibodies was the IgM-ELISA followed by the IgG-ELISA, mouse-neutralization test, hemagglutination inhibition test and complement fixation test.

Adult↗
PubMed1995

Hemorrhagic fever with renal syndrome caused by the Seoul virus.

The Seoul virus is an important etiologic agent in hemorrhagic fever with renal syndrome (HFRS), and infections with the Seoul virus are less severe than those with the Hantaan virus. However, the information on HFRS caused by the Seoul virus is limited in Korea. Retrospective clinical analysis was done on 30 patients with Seoul virus infection who had been diagnosed as having HFRS by clinical features and serologic testing by the plaque reduction neutralization test from 1986 to 1991 at the Seoul National University Hospital. They were compared with 69 patients with Hantaan virus infection. The Seoul virus was the etiologic agent in 25% of Korean HFRS and the major cause of HFRS during the summer season although infections occurred throughout the year. The Seoul virus infection had a milder degree of bleeding and renal derangement but had severer liver dysfunction than the Hantaan virus infection. Renal histopathologic findings revealed a milder degree of hemorrhage and vascular changes than cases involving Hantaan virus infection. The precise mechanisms of vascular dysfunction and organ involvement in Seoul virus infection, however, still remain to be explored.

Adult↗
PubMed1984

Strain differentiation of polioviruses with monoclonal antibodies.

Panels of monoclonal antibodies raised against different poliovirus type 1, 2 and 3 strains, were tested in a micro-neutralization test and in a micro-enzyme linked immunosorbent assay against a large number of poliovirus strains. The results were compared with those obtained with the classical system of serodifferentiation using strain specific cross-absorbed antisera. For this purpose a theoretical pattern fitting computer program was developed, in which each strain could be compared with all the other strains of which the serological data had been stored in the memory of the computer. The results obtained with the panels of monoclonal antibodies coincided well with those obtained with the cross-absorbed antisera. Especially for the identification of virus isolates related to the Sabin vaccine strains, these panels of monoclonal antibodies proved to be valuable tools.

Animals↗
PubMed1976

Studies on group A (phage tail) bacteriocins of Serratia marcescens. V. Serological characterization of subgroup I and II bacteriocins.

Neutralization tests with rabbit hyperimmune sera revealed a close, if not identical, serological relationship among 7 group A (phage tail) bacteriocins of Serratia marcescens of subgroup I, and among 3 phage tail bacteriocins of subgroup II, respectively. On the other hand, subgroup I and II phage tail bacteriocins were found to be serologically unrelated, as determined with neutralization tests and Ouchterlony immunodiffusion experiments. Immunoelectrophoretic tests, employing a representive phage tail bacteriocin of each of the two subgroups, disclosed the electrophoretic mobility of bacteriocin no. 5 (subgroup I), whereas bacteriocin no. 16 (subgroup II) remained stationary. Thus, two additional differential criteria, i.e., differences in antigenicity and electrophoretic mobility, were obtained for the characterization of subgroup I and II group A (phage tail) bacteriocins of S. marcescens.

Animals↗