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PubMedDate not supplied

An ELISA detecting antibody to conserved pestivirus epitopes.

A monoclonal antibody based competition-ELISA is described for the detection of pestivirus antibodies directed against conserved epitopes on the p80 viral protein. The ELISA detected increases in serum antibody following experimentally induced infections of pigs, cattle and sheep with a wide range of pestiviruses, although the sensitivity of the test was not uniform for the different viruses studied. The ELISA was compared with virus neutralization tests for the assessment of porcine, bovine and ovine field sera. At a cut-off value of 50% inhibition, the ELISA showed a high specificity relative to virus neutralization tests, but appeared less sensitive for the detection of some weakly positive samples from pigs. Sera from both ruminants and pigs could be assessed without any modification of the test.

Animals↗
PubMed1982

Typing of herpes simplex virus strains by analysis of the early proteins.

In Herpes simplex virus (HSV) infected cells treated with the arginine analogue canavanine, early (alpha -) viral proteins accumulate and show a typical pattern in the acrylamide gel. This paper investigates the possibility of using this pattern for typing of HSV strains. Twenty strains were analyzed by this method and results were compared with typing by neutralization test. For 18 strains both methods agreed. Two strains regarded as intermediary strains by neutralization test could be clearly typed by the analysis of the early proteins.

Autoradiography↗
PubMed2006

Seroprevalence of tick-borne and mosquito-borne arboviruses in European brown hares in Northern and Western Germany.

Tríbec virus (Kemerovo serogroup, genus Orbivirus), Eyach virus (genus Coltivirus), and Tahyna virus (California encephalitis serogroup, genus Bunyavirus) are arthropod-borne viruses known to occur in Germany. These viruses are also suspected to cause human disease. So far, no information is available on their geographical distribution in Germany and their natural transmission cycles. A total of 166 sera from European brown hares (Lepus europaeus) collected in seven districts of the Federal State of Schleswig-Holstein and in four districts of the Federal State of North Rhine-Westphalia was tested by plaque reduction neutralization test (PRNT) for antibodies against Tríbec virus, Eyach virus, Tahyna virus, and Central European encephalitis virus. One out of 22 sera (4.5%) collected in the district Nord-Friesland in Schleswig-Holstein was found positive (PRNT(90) 1:10) against Tríbec virus. Neither did sera from other regions of Schleswig-Holstein nor from hares from North Rhine-Westphalia react against any of the arboviruses tested. For the first time, antibodies against Tríbec virus could be found in a European brown hare in Germany. The negative serological results for Central European encephalitis virus are in line with the current knowledge of its natural distribution within Germany. The negative serological results for Tahyna virus or Eyach virus argue against an autochthonous circulation of these viruses in the regions tested.

Animals↗
PubMedDate not supplied

Isokinetic evaluation of shoulder rotational strength in high school baseball pitchers.

Isokinetic, shoulder rotational strength was evaluated in 26 high school baseball pitchers before the start of spring practice. Using the Cybex II (Cybex, Division of Lumex, Inc., Ronkonkoma, NY), test data were gathered on the dominant and nondominant shoulders in the supine 90 degrees abducted test position (90 degrees AbTP) and the standing neutral test position (neutral TP). Tests were performed at 90 and 240 deg/sec. The HUMAC (Computer Sports Medicine, Inc., Flemington, NJ) computer system was used to analyze data. Means and standard deviations for peak torque, total work, peak torque to body weight ratios, and agonist/antagonist ratios are presented. Comparison of dominant to non-dominant sides and 90 degrees AbTP to neutral TP values are reported. Peak torque and total work values for the throwing side internal rotators were significantly higher than the nonthrowing side in all tests. Pitching side external rotators failed to show this dominance. External/internal rotation ratios for peak torque and total work were significantly lower on the pitching side, suggesting a relative imbalance of cuff musculature compared to the nonpitching shoulder. Significant differences existed between data gathered in the two different test positions. In the 90 degrees AbTP, external rotation peak torque and total work values and external/internal rotation peak torque and total work ratios were higher than the equivalent values gathered in the neutral TP. Internal rotation peak torque and total work values tended to be higher in the neutral TP than in the 90 degrees AbTP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

[Specificity of the antibody neutralization reaction in indicating Shigella antigens].

The specificity and sensitivity of the antibody neutralization test in the diagnosis of dysentery have been studied. This test has proved to be highly specific in experimental and clinical trials. The antibody neutralization test is more effective than the methods of the isolation of shigellae. The accuracy of this test can be increased by the elimination of different antierythrocyte agents from the secretions of persons under examination.

Antibodies, Bacterial↗
PubMed1981

Detection of antibodies to Herpesvirus simiae and Herpesvirus hominis in nonhuman primates.

Sera from nonhuman primates, predominantly Macaca species, were assayed by a serum neutralization test for antibodies to antigenically related Herpesvirus simiae (B virus) and Herpesvirus hominis type 1. The data indicate that there would have been approximately 50% error in the diagnosis of Herpesvirus simiae infection if these sera had been tested only against Herpesvirus hominis antigen. The role of active guinea pig complement in the serum neutralization test was also evaluated and found to be required by many of the sera for reproducible and enhanced virus neutralization, particularly for B virus antibody determination. A plaque reduction assay was found to be highly sensitive, especially when complement (2.5-5.0 hemolytic units) was added, but impractical for large-scale serum surveys.

Animals↗
PubMed1992

Hantaanvirus among urban rats from a slum area in Bangkok.

A total of 106 rodents sera from slum Wat Phai Ton and slum Klong Toey were examined by immunofluorescent antibody assay during May to August 1990. The positive sera were further tested by plaque reduction neutralization test with the prototype hantaanvirus and the rat-associated hantaan like virus. Isolation attempts were also performed from their tissues. Antibody-positive rats were found in both slum areas, 32.7% in slum Wat Phai Ton and 5.6% in slum Klong Toey. Rattus norvegicus was the major species found positive. Positive plaque reduction neutralization results indicated that the infecting virus was antigenically similar to the strain of rat-associated hantaanvirus. The presence of low titer antibodies (IFA titer 32 to 128) may be an obstacle to isolation of associated virus using tissue culture.

Animals↗
PubMed1997

Virus neutralizing antibody titer to feline immunodeficiency virus isolates of subtypes A, B and D in experimentally or naturally infected cats.

Six strains of feline immunodeficiency virus (FIV) classified into subtypes A, B and D were examined by cross-neutralization test using Kumi-1 cells (CD4+, CD8+, and CD9+), an interleukin-2 dependent feline T-lymphocyte cell line. Neutralizing activities against these six FIV strains were also investigated in 50 FIV-antibody-positive serum samples collected from different geographical regions in Japan. The cross-neutralization test revealed that antisera against the six strains tended to possess high neutralizing activity against the homologous strain. These antisera were also capable of neutralizing viral strains of the same subtype. However, some of the antisera were broadly crossreactive with all six FIV strains. Serum samples collected from naturally infected cats in the field showed various neutralization patterns for the six FIV strains. These observations reflect the antigenic diversity in FIV strains prevailing in the field. There were also broadly crossreactive serum samples, and 36% (18/50 samples) showed neutralization for all six FIV strains.

Animals↗
PubMed1990

An enzyme-linked immunosorbent assay (ELISA) for antibodies to bovine viral diarrhea virus.

A single dilution enzyme-linked immunosorbent assay (ELISA) was developed to detect antibodies to bovine viral diarrhea (BVD) virus in cattle sera. Viral antigen (NADL strain) was grown in a pig kidney cell line (PK15), and after removal of nuclear debris, was purified by ultracentrifugation through a potassium tartrate cushion. Antigen grown in embryonic bovine tracheal epithelial cells was also satisfactory. The test used a high salt buffer to minimize nonspecific reactivity, polyethylene glycol to enhance the reaction, and Protein G as the labelling agent. Comparative testing with the virus neutralization test (VNT) showed the ELISA results to have a high level of correlation with the VNT titers (r = 0.83). In vaccinated animals the ELISA detected antibodies earlier than the VNT. All animals sampled from a BVD-free herd were negative for BVD antibody. The single dilution test showed close agreement (r = 0.84) with ELISA values obtained using a serial dilution technique, and also proved to have a high level of reproducibility. The test procedures were relatively easy to carry out, and were economic in their use of materials.

Animals↗
PubMed2004

Sequence variability in the structural protein-encoding region of foot-and-mouth disease virus serotype Asia1 field isolates.

A total of 30 field isolates of foot-and-mouth disease virus (FMDV) serotype Asia1 belonging to two different lineages and five isolates belonging to a divergent group as delineated earlier in 1D (encodingVP1 protein) gene-based phylogeny were sequenced in the structural protein (P1) coding region. Phylogenetic comparison of these isolates along with some of the published exotic sequences revealed the presence of five different lineages around the world. Similar grouping pattern was observed for the P1 region and 1D gene-based phylogeny, where the Indian isolates were clustered in two genetic lineages. The recently identified divergent group of virus falls into a separate sub-cluster. Similar grouping was also observed in L gene-based phylogeny. Comparison of amino acid sequences identified lineage-specific signature residues in all the structural proteins. Comparison of Asia1 field isolates at the identified key residues of other FMD viruses involved in the formation of the heparan sulfate-binding ligand confirmed many of them to be conserved and the presence of VP3(56) Arg suggested their cell culture adaptation. Although a considerable genetic variation was observed among the isolates of present study, all of them tested in micro-neutralization test were serologically related to the vaccine strain.

Amino Acid Sequence↗
PubMed1995

Development of an alternative method for testing the immunogenicity of diphtheria vaccines.

The immunogenicity of the diphtheria component of 73 commercial vaccines from five different manufacturers was tested by the toxin neutralization test (TNT) and the enzyme-linked immunosorbent assay (ELISA) developed in our laboratory. A comparison of the antibody levels measured by both assays showed a very good correlation (r = 0.95, p < 0.001). The results suggest that the proposed ELISA is a reliable, simple and economical alternative to the TNT in guinea pigs. Also, the ELISA was found to measure IgG antibody levels as low as 5.5 x 10(-5) IU ml-1. To evaluate the possibility of accelerating the active immunization during the activity test of vaccines, an alternative schedule using one single human dose was assayed. A very good correlation was observed between the IgG antibody response obtained with this schedule and with the traditional programme. Therefore, the cost and the time required to perform the activity test may be considerably reduced when both the rapid immunization schedule and the ELISA are used.

Animals↗
PubMed1983

Serological comparison of canine rotavirus with various simian and human rotaviruses by plaque reduction neutralization and hemagglutination inhibition tests.

By the plaque reduction neutralization test, the CU-1 strain of canine rotavirus was similar, if not identical, to three strains (no. 14, no. 15, and P) of the tentatively designated third human rotavirus serotype. In addition, strain CU-1 demonstrated a one-way antigenic relationship with two other strains (M and B) of the third human rotavirus serotype. The CU-1 strain of canine rotavirus hemagglutinated human group O, rhesus monkey, dog, sheep, and guinea pig erythrocytes. A two-way antigenic relationship between canine (CU-1) and simian (MMU 18006 and SA11) rotaviruses demonstrated previously by the plaque reduction neutralization test was confirmed further with two additional isolates (A79-10 and LSU 79C-36) of canine rotavirus by the plaque reduction neutralization test and the hemagglutination inhibition test. The CU-1 strain of canine rotavirus, which is known to be distinct from two well-characterized human rotavirus serotypes (Wa and DS-1), was also found to be distinct from the St. Thomas no. 4 strain, which is a newly defined fourth human rotavirus serotype. Thus, this canine strain, which is related antigenically to one of four human rotavirus serotypes, is another example of an animal rotavirus which shares serotype specificity with a human rotavirus.

Animals↗
PubMed2005

Monoclonal antibody-based antigen capture enzyme-linked immunosorbent assay reveals high sensitivity of the nucleocapsid protein in acute-phase sera of severe acute respiratory syndrome patients.

Accurate and timely diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV) infection is a critical step in preventing another global outbreak. In this study, 829 serum specimens were collected from 643 patients initially reported to be infected with SARS-CoV. The sera were tested for the N protein of SARS-CoV by using an antigen capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the N protein of SARS-CoV and compared to 197 control serum samples from healthy donors and non-SARS febrile patients. The results of the N protein detection analysis were directly related to the serological analysis data. From 27 SARS patients who tested positive with the neutralization test, 100% of the 24 sera collected from 1 to 10 days after the onset of symptoms were positive for the N protein. N protein was not detected beyond day 11 in this group. The positive rates of N protein for sera collected at 1 to 5, 6 to 10, 11 to 15, and 16 to 20 days after the onset of symptoms for 414 samples from 298 serologically confirmed patients were 92.9, 69.8, 36.4, and 21.1%, respectively. For 294 sera from 248 serological test-negative patients, the rates were 25.6, 16.7, 9.3, and 0%, respectively. The N protein was not detected in 66 patients with cases of what was initially suspected to be SARS but serologically proven to be negative for SARS and in 197 serum samples from healthy donors and non-SARS febrile patients. The specificity of the assay was 100%. Furthermore, of 16 sera collected from four patients during the SARS recurrence in Guangzhou, 5 sera collected from 7 to 9 days after the onset of symptoms were positive for the N protein. N protein detection exhibited a high positive rate, 96 to 100%, between day 3 and day 5 after the onset of symptoms for 27 neutralization test-positive SARS patients and 298 serologically confirmed patients. The N protein detection rate continually decreased beginning with day 10, and N protein was not detected beyond day 19 after the onset of symptoms. In conclusion, an antigen capture ELISA reveals a high N protein detection rate in acute-phase sera of patients with SARS, which makes it useful for early diagnosis of SARS.

Antibodies, Monoclonal↗
PubMed2006

Empirical evaluation of neutral theory.

We describe a general framework for testing neutral theory. We summarize similarities and differences between ten different versions of neutral theory. Two central predictions of neutral theory are that species abundance distributions will follow a zero-sum multinomial distribution and that community composition will change over space due to dispersal limitation. We review all published empirical tests of neutral theory. With the exception of one type of test, all tests fail to support neutral theory. We identify and perform several new tests. Specifically, we develop a set of best practices for testing the fit of the zero-sum multinomial (ZSM) vs. a lognormal null hypothesis and apply this to a data set, concluding that the lognormal outperforms neutral theory on robust tests. We explore whether a priori parameterization of neutral theory is possible, and we conclude that it is not. We show that non-curve-fitting predictions readily derived from neutral theory are easily falsifiable. In toto, there is a current overwhelming weight of evidence against neutral theory. We suggest some next steps for neutral theory.

Biodiversity↗
PubMedDate not supplied

[Humoral response to the injection of acellular Pertussis vaccine].

The humoral response of mice and rabbits to the injection of whole-cell pertussis vaccine (PV) and acellular pertussis vaccine (APV), developed at the Mechnikov Research Institute for Vaccines and Sera (Russian Acad. Med. Sci.) in Moscow, was studied. In the sera of immunized animals antibodies to the antigenic complex were determined in the direct hemagglutination (DHA) test, specific antibodies to filamentous hemagglutinin (FHA) and pertussis toxin (PT)--in the enzyme immunoassay (EIA) and antibodies neutralizing PT in a cytopathogenic dose (CPD)--in neutralization test on Chinese hamster ovary (CHO) cells. In mice and rabbits immunized with APV the antibody titers determined in the DHA test were higher than those in the animals immunized with PV. Specific antibodies titers to FHA and PT in the sera of rabbits immunized with APV were also higher than those in the sera of rabbits immunized with PV. High dilutions of sera taken from the animals immunized with APC neutralized 4-16 doses of PT in the neutralization test on CHO cells. The most important result of this study was the detection of a more pronounced immune response in the animals immunized with APV in comparison with that induced by PV according to the results obtained in EIA and in the test of PT CPD neutralization on CHO cells.

Adhesins, Bacterial↗
PubMed1989

[Erythrocytic diagnostic agents for determining antibodies to Proteus O antigens].

Highly sensitive and specific erythrocyte diagnostic agents (ED) for the determination of antibodies to Proteus O-antigens have been obtained by the sensitization of formolated sheep red blood cells (SPBC) with activated lipopolysaccharides (LPS) without the use of mediators. The tannin treatment of formolated SRBC and/or the increase of temperature from 45 degrees C to 100 degrees C in the process of the preparation of ED have been found to produce no increase in effectiveness. Antibody ED permitting the detection of Proteus O- and H-antigens has been obtained by the sensitization of formolated chick red blood cells with immunoglobulin preparations to Proteus hydroxylamine antigens, carried out with the use of amidol. The experiments have shown the possibility of using this antibody ED for the determination of O-antibodies in the antigen neutralization test with nonactivated LPS used as an agglutinating agent. The passive hemagglutination test with antibody ED has proved to be a more sensitive method for the detection of O-antibodies than the antigen neutralization test with antigenic ED. The determination of Proteus etiology in the passive hemagglutination test with the use of antigenic ED has been shown to be highly effective in the examination of patients with chronic osteomyelitis at the stage of exacerbation.

Animals↗
PubMed1979

Enhanced antiglobulin-mediated neutralization of herpes simplex virus-IgG complexes by complement and heterologous anti-immunoglobulin.

The ability of IgG anti-Fc and anti-Fab to neutralize infectious herpes simplex virus-IgG (HSV-IgG) complexes was determined. When limiting amounts of antiglobulin were used, antibody directed against the Fab portion of human IgG was significantly more effective than anti-Fc antibodies in neutralizing the HSV-IgG complexes. The detection of viral bound antibody was enhanced by the incorporation of heterologous antiglobulin or complement in the antiglobulin neutralization test. Specifically, HSV-IgG which had been incubated with rabbit antihuman globulin was further neutralized by goat antirabbit IgG or guinea pig serum complement. This augmented neutralization test could prove useful in detecting small amounts of antibody bound to virus in infectious isolates from patients or experimental animals with viral diseases.

Animals↗