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PubMed1994

[Pathogenicity of avian adenoviruses in chickens].

In the last years avian adenoviruses have caused diseases with similar symptoms and high losses in four countries. The causative viruses could be grouped by cross-neutralization tests and restriction enzyme analysis into four serotypes. Within the serotypes there exist strains with pathogenic properties as well as strains without pathogenicity. Epidemiologic investigations demonstrated that not only immunosuppression or co-infections produce diseases after adenovirus infections. Vertical transmission of the virus from parent stocks and deficiency of specific maternal antibodies in the chickens contribute to the development of diseases. Parent stocks, which were infected with different serotypes of adenovirus during their rearing period, produce chickens with maternal antibodies. These chickens are protected against early infections with avian adenoviruses.

Adenoviridae Infections↗
PubMed2004

Antiproliferative and differentiating effects of polysaccharide fraction from fu-ling (Poria cocos) on human leukemic U937 and HL-60 cells.

Poria cocos (PC), Fu-Ling, is an oriental fungus and has been widely used as a Chinese traditional herbal medicine for centuries. In the present study, a neutral polysaccharide fraction from PC (PC-PS) was isolated by a series of chromatographies and its effects on antiproliferation and differentiation of human leukemic cells, U937 and HL-60, were investigated in vitro. Results showed that the molecular weight of isolated PC-PS was approximately 160 kDa, as estimated by gel permeation chromatography. The conditioned medium prepared with PC-PS (15 microg/ml)-stimulated human blood mononuclear cells for 5 days (PC-PS-MNC-CM5) exhibited a potent activity in suppressing the proliferation of U937 and HL-60 cells by 87.3 and 74.7%, respectively. Furthermore, PC-PS-MNC-CM5 induced about 66.6% of the U937 cells and 49.4% of the HL-60 cells to differentiate into mature monocytes/macrophages, which also markedly expressed surface antigens of CD11b, CD14, and CD 68. The differentiated U937 and HL-60 cells displayed physiological functions such as respiratory burst and phagocytosis, while PC-PS group and control group showed insignificant effects. Interestingly, the levels of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha in PC-PS-MNC-CM were about 41 and 10 times, respectively, higher than that of control group. Antibody neutralization tests of the PC-PS-MNC-CM5 revealed that the growth-inhibitory and differentiation-inducing activities were mainly due to the elevated cytokines of IFN-gamma and TNF-alpha. It suggests that PC-PS is a biological response modifier (BRM), instead of a cytotoxic reagent, and may be a potential alternative in leukemia therapy.

Antigens, CD↗
PubMed1987

Properties of strains of Escherichia coli belonging to serogroup O157 with special reference to production of Vero cytotoxins VT1 and VT2.

Fifty-four strains of Escherichia coli belonging to serogroup O157 were examined for the production of Vero cytotoxins VT1 and VT2, and for other properties such as plasmid content, resistance to antimicrobial agents and colicin production. Twenty-six strains from cases of diarrhoea, haemorrhagic colitis and haemolytic uraemic syndrome in humans produced VT. By serum neutralization tests and hybridization with DNA probes for VT1 or VT2, three classes were recognized which produced either VT1 alone or VT2 alone or both VT1 and VT2. These strains were of H type 7 or non-motile. The strains producing VT were sensitive to all the antimicrobial agents tested, and all carried at least one plasmid which had a molecular weight of c. 60 X 10(6). Seven strains of porcine origin and 21 strains of human origin did not produce VT or hybridize with either DNA probe. None of these strains was of H type 7. Of the 21 human VT- strains, 17 were of extra-intestinal origin and 18 were of H type 45. Twenty-three of the 28 VT-strains were resistant to at least one antimicrobial agent.

Cytotoxins↗
PubMed1984

Douglas and Tinaroo viruses: two Simbu group arboviruses infecting Culicoides brevitarsis and livestock in Australia.

Two Australian members of the Simbu group, Douglas and Tinaroo viruses, were found to be distinct, by virus-neutralization tests, from three previously known Simbu group viruses isolated in Australia, namely Akabane, Aino and Peaton viruses. A low-titre, two-way, cross-reaction was noted between Akabane and Tinaroo viruses. Antibody to Tinaroo and Douglas viruses was detected in serum from cattle, buffalo, sheep, goats and deer but not in humans, pigs, kangaroos and wallabies. The results for horses were inconclusive. The distribution of antibodies to each virus falls mainly within the geographical distribution of the biting midge Culicoides brevitarsis, an insect from which each virus has been isolated.

Animals↗
PubMed1980

Prevention of varicella in urgent cases by passive transfer of vaccine-induced immunity.

For the purpose of preventing spread of infection to high risk children whose immunities were severely impaired by intensive chemotherapy or for some other reason, when cases of varicella occurred in a children's ward or in a family, healthy adults (mothers and a doctor) were immediately given live varicella vaccine, blood was collected from these adults 5 to 7 days after vaccination and the whole blood or plasma including the buffy coat was transferred in the high risk children. Subsequently the children showed little or no clinical reaction, and follow-up studies by the neutralizing test and skin test with varicella antigen indicated that their inapparent or subclinical varicella infection occurred in them and that their immunity to varicella was lasting. Skin tests with varicella antigen showed that booster reaction occurred in adults with a previous history of varicella as early as 5 to 7 days after vaccination. The cellular immunity thus induced in the donors may have played a role in preventing a clinical reaction in the high risk children. Thus passive transfer of vaccine-induced immunity seems a convenient and effective method for preventing infection in subjects whose immune capacities are severely impaired.

Adult↗
PubMed2004

Molecular epidemiology of mumps virus in Japan and proposal of two new genotypes.

We isolated 872 strains of mumps virus from naso-pharyngeal secretions in seven different districts of Japan from January 2000 to July 2001. Among them, 57 strains were geno-typed by nucleotide sequencing in part of the hemagglutinin-neuraminidase (HN) and small hydrophobic (SH) protein regions. Four different genotypes (B, G, K, and L) of mumps virus were co-circulating in Japan and the distribution of genotypes varied in geographically different districts. Two new clusters designated as genotypes K and L had more than 7% nucleotide variation in the SH gene. Among the 57 strains, 11 were classified as B, 35 as G, three as K, and eight as L, which was mainly isolated in Tokyo. We also examined 104 stains isolated in a clinic in Mie prefecture from 1993 to 2003. Genotype B was the indigenous strain and genotype K was introduced in 1994. Genotypes B and K co-circulated in the 1990s and were replaced by genotype G in 2000. There was no significant change in neutralizing test antibody titers against genotypes B, G, K, and L using seven post-vaccination sera with Hoshino strain (genotype B) and these four genotypes had a different antigenicity from genotype A. We should continue to watch on mumps virus molecular epidemiology.

Amino Acid Sequence↗
PubMed1979

Cross-neutralization study of seven California group (Bunyaviridae) strains in homoiothermous (PS) and poikilothermous (XTC-2) vertebrate cells.

Antigenic relationships among seven California group strains were studied by a plaque-reduction neutralization test (PRNT). Cross-reactions occurred in most cases but three subgroups were noted: (1) the major serogroup contained the viruses of California encephalitis, LaCrosse, Snowshoe Hare and Trahyna (including the Lumbo strain) whereas (2) Jamestown Canyon and (3) Trivittatus viruses were distinct. There was no significant difference between the PRNT results in mammalian (PS) cells incubated at 37 degrees C and amphibian (XTC-2) cells incubated at 28 degrees C. Trivittatus virus failed to produce plaques in XTC-2 cells.

Animals↗
PubMed1980

Identification of Bulgarian strain 258 of enterovirus 71.

In 1975 in Bulgaria a severe epidemic of central nervous system (CNS) disease occurred. Clinically, histopathologically, and epidemiologically the cases resembled poliomyelitis, aseptic meningitis, meningoencephalitis, and, in some cases, encephalomyocarditis. About 21% of the 700 reported cases developed paralysis, 44 with fatal outcome [ref. 1]. In 65 cases, 92 strains of enterovirus of the same serologic type were isolated: 38 strains from the CNS, 10 from mesenteric lymph nodes and tonsils, and 44 from feces [ref. 1,2]. A typical representative strain, No. 258, isolated from the spinal cord of a 3-month-old baby who died on the 5th day of disease with signs of focal polioencephalitis, was selected for intensive study. Cross-neutralization tests established the antigenic identity of the Bulgarian 258 strain (Stanchev) with American strains of enterovirus type 71 (BrCr and JaFr strains) and Swedish strains of the same type (Nos. 52343, 52500, and 6041). From its biological [ref. 1,2], physicochemical [ref. 3], and antigenic properties, the etiological agent of this large epidemic can be classified as a member of enterovirus type 71, one of the most highly pathogenic of the recently recognized enteroviruses.

Animals↗
PubMedDate not supplied

[Comparison of a few methods for detecting antibodies to the bovine leukemia virus].

A comparative analysis of the results of bovine sera examinations by three methods for the detection of antibody to bovine leukemia virus (BLV): VSV BLV pseudotype neutralization test (PTNT), gel immunodiffusion using BLV glycoprotein antigen (GIDgp) and BLV 125I-p24 radioimmunoprecipitation (RIPp24), was performed. The results of all the three methods were in good correlation. The PTNT sensitivity was shown to exceed essentially all the other methods of BLV antibody detection. There was a definite correlation between the serum titer in PTNT and the possibility of antibody detection in RIPp24 and GIDgp. The potentials of these methods for diagnosis of BLV infection in animals are discussed.

Antibodies, Viral↗
PubMed1990

Isolation of Tete serogroup bunyaviruses from Ceratopogonidae collected in Colorado.

Two viruses were isolated from ceratopogonid midges collected in northern Colorado. Electron microscopy indicated that both isolates were bunyavirus-like. Indirect fluorescent antibody and serum dilution-plaque reduction neutralization tests showed that these isolates were members of the Tete serogroup, most closely related antigenically to Tete and Batama viruses but distinguishable from both and from each other. We suggest the name Weldona virus for these isolates. Antibody in both waterfowl and passerine birds in northern Colorado indicates the enzootic presence of these viruses in northern Colorado and raises unanswered questions about the introduction and establishment of Tete serogroup viruses in the Americas.

Animals↗
PubMed1998

Adverse impact of infections on antibody responses to measles vaccination.

Antibody titres were determined in 102 Thai infants who were vaccinated at 9-months of age during the respiratory disease season. The symptom densities of illnesses at or following vaccination, including rhinorrhea and diarrhea, were significantly lower among seroconverters, although the simple presence or absence of specific symptoms was not significantly related to seroconversions. Logistic regression indicated that neutralization test antibody titres below the median titre of 1:80 following vaccination were significantly more frequent among those with rhinorrhea when vaccinated and among those with diarrhea after vaccination. Compared with a referent group without these symptoms, titres were lower in those who had rhinorrhea when vaccinated, rhinorrhea during the first week post vaccination, and diarrhea in either of the two follow-up weeks. Illnesses concurrent or subsequent to measles vaccination adversely affected antibody responses in these study objects.

Antibodies, Viral↗
PubMed1967

Negro variant of glucose-6-phosphate dehydrogenase deficiency (A-) in man.

Glucose-6-phosphate dehydrogenase in erythrocytes of the Negro type associated with enzyme deficiency (A(-)) was separated by chromatography on a carboxymethyl-Sephadex column from the electrophoretically indistinguishable Negro variant with normal enzyme activity (A(+)). Quantitative immunologic neutralization tests indicated that the A(-) enzyme had about the same enzymatic and serological activity as the A(+) and the normal (B(+)) enzymes. The enzyme activity of the A(-) variant in young erythrocytes was similar to that in young cells from normal individuals, although the activity of the A(-) variant in unfractionated red cells was 10 to 15 percent of normal. These data indicate that the basic defect in the variant enzyme (A(-)) is a structural mutation which causes more rapid degradation of the enzyme during erythrocyte aging.

Black or African American↗
PubMed1983

Effect of immune serum on infectivity of Rickettsia tsutsugamushi.

Hyperimmune antirickettsial serum was shown to prevent the attachment/penetration stage of Rickettsia tsutsugamushi infection of suspended chicken cells. The extent of the inhibition depended on the serum concentration but not on the presence of complement. The neutralizing activity was reduced by prior adsorption of immune serum with staphylococcal protein A or with intact rickettsiae but was not affected by adsorption with target cells. In the neutralization tests, there was no cross-reactivity between the Karp and Gilliam strains of R. tsutsugamushi. Incubation of rickettsiae with immune serum did not alter their capacity to metabolize glutamate nor grossly damage the permeability barrier function of their cytoplasmic membranes. Although the assay method had the capacity to detect some aggregated infectious organisms, none were found in immune serum-treated suspensions. It was concluded that immune serum may inhibit rickettsial infection by blocking a surface component(s) whose function is necessary for attachment to and/or penetration of target cells.

Animals↗
PubMed1985

Neutralizing antibodies to pertussis toxin in whooping cough.

The development and duration of neutralizing antibodies (antitoxin) to pertussis toxin were studied in 38 patients with culture-verified infections due to Bordetella pertussis and one patient with infection due to Bordetella parapertussis. An in vitro neutralization test in microplate culture of Chinese hamster ovary cells was used. An antitoxin response was recorded in 36 patients, the exceptions being two patients treated early with erythromycin (one of whom developed clinical pertussis two years later) and the patient with infection due to B. parapertussis. A long-term follow-up for several months to several years after disease showed maintenance of high antitoxin levels. These results are in accordance with the hypothesis that antibodies to pertussis toxin mediate long-term immunity to whooping cough.

Adult↗
PubMed2005

Protective immune response against foot-and-mouth disease virus challenge in guinea pigs vaccinated with recombinant P1 polyprotein expressed in Pichia pastoris.

Vaccination of the susceptible livestock with potent, safe and cost effective vaccine is the primary requirement to control foot-and-mouth disease (FMD) in an endemic country. In this study, an alternative approach was used in which structural protein genes of all the four serotypes of FMDV (O, Asia 1, A22 and C) were expressed separately in methylotrophic yeast Pichia pastoris. The recombinant polyproteins (P1) were characterized by SDS-PAGE and in Western Blot analysis. Partially purified protein was used for immunization in guinea pigs with different adjuvant formulations and immune response studied. Ninety micrograms of the recombinant protein per monovalent dose was used for immunization. A single injection of a monovalent or polyvalent vaccine was given to guinea pigs with various adjuvant combinations viz., Monovalent recombinant protein either adjuvanted with Montanide-ISA50V or Indigenous oil, Monovalent recombinant protein mixed with 1/10th dose of inactivated oil-adjuvanted virus vaccine and Polyvalent recombinant protein with Montanide ISA50V. FMDV specific humoral immune response was observed at about 28th day post vaccination. The immune response as assessed by indirect ELISA and Serum neutralization test titres was found to be 320-640 and 16-32, respectively. When challenged with virulent homologous type 'O' virus, the guinea pigs showed protective C index of 2.01,1.81, 2.56 and 2.48, respectively, with above said adjuvant combinations. The study has shown that yeast-expressed FMDV P1 polyprotein in a single dose could elicit a protective immune response in guinea pigs, and this could be a possible future vaccine candidate in homologous host.

Animals↗
PubMedDate not supplied

Comparative study of adenoviruses with monoclonal antibodies.

The obtainment of monoclonal antibodies for adenovirus species 4(Ad4) is described. The specificities of selected monoclonal antibodies were determined by means of viral neutralization test in cell culture, immunofluorescence and Enzyme-Linked Immunosorbent Assay (ELISA), in the presence of the following species of human adenovirus: 1, 2, 5 (subgenus C), 4 (subgenus E), 7 and 16 (subgenus B) and 9 (subgenus D). Two monoclonal antibodies species specific to adenovirus 4 (1CIII and 3DIII) and one monoclonal antibody that cross reacted with adenovirus species 4 and 7 (2HIII) were obtained.

Adenoviruses, Human↗
PubMed1977

[Results of studying a live mumps vaccine from strain L-3 manufactured by the Moscow Research Institute of Viral Preparations. The reactogenic and antigenic properties of the vaccine].

The reactogenic and antigenic properties of live mumps vaccine from the L-3 strain were studied in 1507 children of 1 to 12 years of age. A single injection was given, one immunizing dose containing 10(4)HAdU50 of mumps virus. The live mumps vaccine from the L-3 strain irrespective of the lot of preparation, kind (live or lyophilized), method of application (jet-injector or needle/syringe), age of the vaccinees and the amount of virus in the immunizing dose received by a vaccinee, was demonstrated to be practically areactogenic and markedly antigenic. Serological examinations by neutralization tests of 346 paired serum specimens established variation in seroconversion between individual lots to be within 62.5--82.3% (average 69.9%) of cases. Comparative studies on the postvaccination and postinfection immunitiy in mumps showed the level of antibody in the vaccinees to vary within 4.2--5.1 log2 in different years, and in convalescents within 5.1--5.9 log2 in the same years. The results indicate a sufficiently high and intensive immunity for 5 years (the observation period).

Antigens, Viral↗
PubMed1985

Preparation and characterization of neutralizing monoclonal antibodies with different reactivity patterns to human rotaviruses.

By employing three strains of cultivable human rotaviruses with different serotype specificity as immunizing antigens, we prepared 11 hybridomas which secreted neutralizing monoclonal antibodies against human rotaviruses. In neutralization tests with four strains of serotype 1, and three each of serotypes 2 and 3, the monoclonal antibodies showed different reactivity patterns: seven monoclonal antibodies reacted specifically with all strains of either serotype 1, 2 or 3 human rotavirus, but two showed strain-specific reactions; the remaining two were commonly reactive to various human rotavirus strains from each serotype but not to two non-human rotaviruses. By immunoprecipitation analysis, it was found that four serotype 2-specific and two commonly reactive antibodies were directed to VP3 (82000 mol. wt. protein) on the outer shell of the virus particles.

Antibodies, Monoclonal↗