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PubMed1975

Concanavalin A agglutination of cells from primary hepatocellular carcinomas and hepatic nodules induced by N-2-fluorenylacetamide.

A previous study demonstrated that cells of transplantable hepatocellular carcinomas were agglutinated by the plant lectin concanavalin A, while normal hepatocytes were not. In the present experiments, 95% or more of cells obtained from primary hepatocellular carcinomas which resulted from exposure of rats to N-2-fluorenylacetamide were agglutinated by this lectin. Exposure to this carcinogen also produces grossly visible foci of morphologically and biochemically altered hepatocytes which have been termed hepatic (hyperplastic; premalignant, neoplastic) nodules. Although these hepatocyte aggregates are generally accepted as precursors of the hepatocellular carcinomas, no agglutination was detected when their cells were exposed to concanavalin A. These results indicate that concanavalin A agglutinability is not acquired as a result of tumor transplantation. Furthermore, they suggest that significant alterations must occur in the cells of hepatic nodules prior to the manifestation of malignant behavior.

2-Acetylaminofluorene↗
PubMedDate not supplied

Serotyping of Haemophilus paragallinarum by the Page scheme: comparison of the use of agglutination and hemagglutination-inhibition tests.

Seventy-two isolates of Haemophilus paragallinarum were serotyped according to the Page scheme, using a new hemagglutination-inhibition (HI) test. The results were compared with the plate agglutination method conventionally used in the Page scheme. The HI test used washed cells of H. paragallinarum, glutaraldehyde-fixed chicken erythrocytes, and rabbit antisera originally produced for the agglutination method. For 49 of the isolates, there was complete correlation between the results of the HI serotyping test and the previously performed agglutination test--23 were serovar A, two were serovar B, and 24 were serovar C. The other 23 isolates were nontypable by the agglutination test, but 21 of them could be serotyped by the HI method--six as serovar A, two as serovar B, and 13 as serovar C. Nine isolates required treatment of the bacterial cells with hyaluronidase for the expression of hemagglutination (HA) activity. Two isolates did not have HA activity despite hyaluronidase treatment and so could not be serotyped by the HI test.

Agglutination Tests↗
PubMedDate not supplied

Sensitivity and specificity of Mycoplasma gallisepticum agglutination antigens prepared from medium with artificial liposomes substituting for serum.

Three batches of strain A5969 Mycoplasma gallisepticum (MG) serum-plate-agglutination (SPA) antigen grown in regular Frey's medium with 12% swine serum, three batches grown in Frey's medium containing artificial liposomes instead of serum, and one commercial SPA antigen were evaluated for sensitivity and specificity. Sensitivity was measured using chickens exposed to MG by intraocular and intranasal inoculation. Specificity was measured in uninoculated controls and in groups inoculated with the oil-emulsion vaccines Haemophilus paragallinarum, infectious bursal disease inactivated virus vaccine, or Staphylococcus aureus. Sera were tested 1 to 8 weeks postinoculation. All SPA antigens had a perfect sensitivity score, except one liposome-grown antigen batch (LC). The two other liposome-grown antigen batches (LA and LB) maintained significantly higher specificity by yielding significantly (P less than 0.01) fewer false positive (FP) agglutination reactions than did the other antigens. The three antigen batches produced in medium with serum had intermediate levels of FP agglutination reactions. When known MG-negative sera were tested, MG SPA antigens LC and commercial SPA antigen yielded significantly (P less than 0.01) higher numbers of FP agglutination reactions than the other SPA antigens.

Agglutination Tests↗
PubMed1989

A rapid method for detection of flavivirus antigens: staphylococcal co-agglutination test using monoclonal antibodies to Japanese encephalitis virus.

Staphylococcus aureus rich in protein A when coated with monoclonal antibodies (MoAb) to Japanese encephalitis virus (JEV) gave a highly specific reaction with flavivirus antigens. The bacteria coated with JEV species-specific MoAb gave a strong co-agglutination with fifty-six JEV isolates from various parts of China, but no co-agglutination with Murray Valley encephalitis (MVE) and Kunjin (Kun) virus antigens. The flavivirus- and subgroup-specific MoAbs were reactive with MVE and Kun, as well as with the majority of the JEV strains. Blocking test with homologous MoAbs abolished co-agglutination further confirming its specificity. Numerous virus particles were observed on the surface of MoAb-coated staphylococci under the electron microscope after co-agglutination. The test appeared rapid, specific, simple to perform, and useful for rapid detection and identification of flaviviruses.

Agglutination Tests↗
PubMed1985

Identification by cross-agglutination absorption and restriction endonuclease analysis of leptospires of the Pomona serogroup isolated in the United Kingdom.

Five strains of Leptospira interrogans isolated in the United Kingdom and belonging to the Pomona serogroup were subjected to cross-agglutination absorption and bacterial restriction endonuclease DNA analysis (BRENDA) for their identification. British isolates were compared with reference strains representing the known serovars in the Pomona serogroup and also with isolates of the Pomona serogroup obtained from other countries. Three strains isolated from wildlife in England produced equivocal results when the cross-agglutination absorption and BRENDA results were compared. According to the World Health Organisation definition of a serovar the three English strains represented two new serovars, whereas by BRENDA all three had DNA electrophoresis patterns indistinguishable from serovar mozdok. Serovar pomona has not as yet been isolated in Great Britain and the epidemiology of the Pomona serogroup infections that have been detected by serology suggests that a serovar such as mozdok, maintained by wildlife, may be the causal agent. Two strains isolated in Northern Ireland were identified as pomona by the cross-agglutination absorption test. Further studies are needed to investigate the homogeneity of field and reference strains that are designated as pomona using the cross-agglutination absorption test.

Agglutination Tests↗
PubMed1986

Von Willebrand factor-dependent agglutination of washed fixed human platelets by insoluble collagen isolated from bovine aorta.

Adult bovine aortic tissue was homogenized in a neutral phosphate buffer containing proteinase inhibitors. The insoluble residue was rehomogenized in Tris-buffered 6 mol/L guanidinium chloride (pH 7.4). An insoluble fibrillar protein, floating above the main pellet after recentrifugation, was harvested. This material agglutinated washed fixed human platelets in the presence of either normal human plasma or purified von Willebrand factor (vWF). No such reaction was seen when either buffer or plasma from patients with severe von Willebrand's disease was added instead. The extent of platelet agglutination was measured photometrically, similarly to the ristocetin cofactor assay. The agglutination reaction was strongest at neutral pH and was impaired after either addition of EDTA or previous digestion of the fibrillar material by collagenase or pepsin. By light microscopy platelets were seen to adhere onto isolated fibers. Amino acid composition, subunit polypeptides, substrate properties, and interaction with fibronectin of this fibrillar protein were comparable to those of collagen. Therefore, we tentatively denote the induction of platelet agglutination by vWF protein in the described test system as "vWF-collagen cofactor" activity. Comparison of this activity in 65 plasma samples, containing various concentrations of vWF, with ristocetin cofactor activity showed good correlation between results obtained in both tests (r = 0.91).

Agglutination Tests↗
PubMed1986

[Polish standard for anti-Brucella abortus serum for agglutination as the basis for the standardization of the antigen for the rose bengal plate test].

The aim of the study was to test out the usability of Polish Standard of anti-Brucella abortus serum in agglutination for standardization and control of antigen commercial manufacturing. Polish Standard of anti-Brucella abortus serum in agglutination tube test (PSaBaS-SAT) was separated on Sefadeks G-200 gel to determine the content of anti-Brucella antibodies of IgM class, characteristic of the first stage of infection, and IgG antibodies typical for chronic disease. Serological examinations of the fractions obtained, revealed significant domination of specific IgG antibodies over IgM. Visible activity of IgG in RBPT (Rose Bengal Plate Test) and in other serological test used in Poland to recognize brucellosis, was observed. It enables us to use PSaBaS-SAT in the determination of agglutinability of acid antigen as the antibodies of this class are commonly recognized to be a specific indicator of active brucellosis on the contrary to IgM which may be of non specific character. It is suggested that additional testing of agglutinability of acidic antigen, compared to IgM antibodies is not necessary and increases the cost of studies. Moreover, the examination of animals twice a year, using RBPT gives slight probability to find animals in their first stage of infection (high level of IgM in serum) as the only ones in the population studied.

Agglutination Tests↗
PubMed1971

Proposed standardization of the agglutination-adsorption test for Leptospira.

The systematics of the Leptospira is based on the agglutination test and on the cross-agglutination-adsorption test. To obtain reproducible and comparable results these tests must be carried out by standard techniques, but the accuracy of the tests is in any case limited since immune sera prepared from animals do not always react uniformly. Moreover, the micro-organisms used in the tests have specific requirements and do not always develop properly in synthetic media. The various factors that influence the results of agglutination-adsorption tests were investigated and evaluated. Taking the results of these studies into account, a standardized method for agglutination-adsorption tests is proposed and described.

Adsorption↗
PubMed1978

Specific inhibition of platelet agglutination and aggregation by aromatic amidino compounds.

A series of aromatic amidino compounds were investigated for their inhibitory effect on platelet agglutination and platelet aggregation. Agglutination of fresh or fixed platelets was produced by bovine plasma or by human plasma in combination with ristocetin, while aggregation of fresh platelets was induced by ADP, thrombin or collagen. Highly effective inhibitors were found for both types of platelet clumping, but there was no parralelism between the inhibitory activities in the two test system. 5-(5-amidino-2-benzimidazolyl)-2-(4-hydroxybenzene)benzimidazole suppressed agglutination exclusively. Pentamidine, on the other hand, strongly blocked the aggregation reaction, but did not interfere with agglutination, even at high concentrations. Compounds which inhibited aggregation also prevented the liberation of serotonin from the platelets.

Adenosine Diphosphate↗
PubMed1982

Incidence of serum agglutinating and immobilizing sperm antibodies in infertile couples.

Blood specimens from 285 consecutive infertile couples were treated for sperm agglutination and for sperm immobilization by the tray slide agglutination test and a microimmobilization test. The immobilization test was positive only when the agglutination test was also positive. Sperm immobilizing activity in association with agglutinating activity was detected in the serum of 7.5% of the husbands and 1.4% of the wives. These sperm immobilizing activity figures may represent the actual incidence of antibodies in patients attending the author's service.

Agglutination↗
PubMed1984

Measurement of serum antibody in swine vaccinated with Bordetella bronchiseptica: comparison of agglutination and enzyme-linked immunosorbent assay methods.

The immune responses of 514 pigs from 5 swine breeds (Chester White, Duroc, Hampshire, Landrace, Yorkshire) to vaccination with Bordetella bronchiseptica were measured by agglutination and enzyme-linked immunosorbent assay (ELISA) methods. Both assays showed higher antibody levels in sera of pigs after vaccination than in sera of the pigs before vaccination. The variability of the responses among breeds was greater for the agglutination method than for the ELISA method. The ELISA proved to be more sensitive than the agglutination method and could detect antibody in serum samples diluted at least 100-fold more than those used in the agglutination procedure. The correlation of antibody titers obtained by the 2 methods was small, but statistically (P less than 0.01) significant. The ELISA should be useful for determinations of antibody responses of swine to B bronchiseptica.

Agglutination Tests↗
PubMed1983

Serological diagnosis of brucellosis in water buffaloes (Bubalus bubalis): comparison among complement fixation, serum agglutination and rose bengal plate test.

The results of a comparative study among complement fixation (CFT), plate agglutination (PAT), tube agglutination (TAT) and Rose Bengal plate tests ( RBPT ) to the serodiagnosis of brucellosis in Indian buffaloes are reported. Sera from 212 buffaloes unvaccinated against brucellosis were examined and the CFT was able to reveal significant titres in sera with low agglutinating titres. From 109 sera which did not show agglutination titres in the PAT, four showed complement fixing titre greater than 1 in 200. All the positive sera to the RBPT gave complement fixing titre equal to or greater than 1 in 20. In sera that showed negative result to the RBPT the CFT was able to reveal relatively high titres. From 131 sera negative to the RBPT five showed complement fixing titres greater than 1 in 60.

Agglutination Tests↗
PubMedDate not supplied

[Detection of hybrid cells secreting monoclonal immunoglobulins using Staphylococcus aureus agglutination].

A quantitative assay for mouse monoclonal immunoglobulins (Ig) was made possible by a very simple and sensitive co-agglutination test. Staphylococci which were rich in protein A were used in the presence of sheep anti-mouse IgG (H + L) antibodies. The assay was conducted in a single step using micro-haemagglutination plates. Plates were scored after over-night incubation. This method could detect as little as 0.006 microgram of IgG/ml. One set of hybrids was screened both by this method and by an immunoenzymatic assay (ELISA): with one exception, all clones which were found to produce Ig by ELISA were also positive by co-agglutination. Moreover, the co-agglutination method detected 7 additional Ig-secreting cultures. The level of secretion of each positive hybridoma ranged from 0.2 to 2 micrograms/ml. Thus, when compared to ELISA, the co-agglutination test was not only just as sensitive, but was also much simpler and faster.

Agglutination Tests↗
PubMed1983

Comparative study among complement fixation, serum agglutination and Rose Bengal Plate tests in the serodiagnosis of bovine brucellosis.

The complement fixation test (CFT) based on the 50 per cent hemolytic end point technique was applied to the diagnosis of bovine brucellosis in a comparative study involving the plate agglutination test (PAT), the tube agglutination test (TAT) and the Rose Bengal plate test (RBPT). Among 180 bovine sera that were examined the CFT was able to reveal significant titres in sera that gave low agglutinating titres. Some sera with agglutinating titres between 1 in 50 and 1 in 100 did not given a titre in the CFT. The results show that the CFT is useful for bovine brucellosis diagnosis and may be used after sera screening with PAT and RBPT.

Agglutination Tests↗
PubMed1983

Agglutination and phagocytosis of pneumococci by immunoglobulin G antibodies of restricted heterogeneity.

Sera from rabbits that were hyperimmune to type 3 or type 8 pneumococcal capsular polysaccharide were fractionated by starch block electrophoresis, and fractions containing large quantities of anticapsular IgG of restricted molecular heterogeneity were evaluated for their ability to agglutinate and opsonize encapsulated pneumococci. Specific anticapsular IgG was readily absorbed by the organisms. Each CFU of type 3 organisms was capable of absorbing 5 X 10(7) molecules of IgG, and the type 8 organisms absorbed 5 X 10(6) molecules/CFU. Only small amounts of nonimmune IgG were absorbed. Agglutination occurred only after 10(6) molecules/CFU IgG had been absorbed by type 3 organisms, and 10(4) to 10(5) molecules/CFU had been absorbed by type 8 organisms. After larger quantities of IgG had been absorbed, a prozone phenomenon was apparent. Anticapsular IgG in the absence of complement did not promote phagocytosis by human or rabbit PMNs below levels that caused agglutination. In the presence of complement, only about one tenth as much IgG was necessary to promote phagocytosis. Thus these encapsulated pneumococci can absorb large quantities of specific rabbit IgG antibody of restricted heterogeneity. In the presence of complement, approximately 1% of the antibody that can be absorbed by the organisms will promote phagocytosis. In the absence of complement, approximately 10% of the antibody that can be absorbed is required for agglutination or phagocytosis.

Agglutination Tests↗
PubMed1980

[Diphtheria toxin: ability to agglutinate human leukemia cells].

Human leukaemic cells were agglutinized by diphtheria toxin during an incubation of two hours. the agglutination behaved as a phenomenon of prozone. The cells grouped only in the zone with fitting proportion between toxin and cells, while no aggregation took place where lower or higher doses of toxin were used. The toxin didn't induce the agglutination of granulocytes taken from patients with acute infections diseases or taken from healthy donors. Normal lymphocytes too were not glutinated by toxin. The leucocytic agglutinability caused by toxin may be correlated to changes on the membrane induced by malagnity.

Agglutination↗
PubMed1982

Serology of Campylobacter fetus ss. jejuni. 2 Serotyping of live bacteria by slide, latex and co-agglutination tests.

Antisera against 12 campylobacter strains (8 C. fetus ss. jejuni, 2 ss fetus and 2 ss. intestinalis) were obtained from rabbits immunized with formalin treated bacteria. Cross testing of live boiled and autoclaved organisms of these strains were performed with direct slide and tube agglutinations, and with agglutinations of latex particles and protein A-containing staphylococci coated with antibodies. Confirmed by absorption experiments both heat labile and heat stable antigens were demonstrated. The highest specificity for serological differentiation was obtained with slide and latex agglutination with live bacteria, which were subsequently used for differentiation of C. fetus ss. jejuni strains. For this purpose we applied 22 C. fetus ss. jejuni antisera absorbed with boiled homologous bacteria. Clearcut homologous reactions, with few and weak crossreactions, indicated the presence of a variety of heat labile antigens, which could form a basis for serotyping. Preliminary typing of 170 clinical isolates with slide agglutination using 17 unabsorbed C. fetus ss. jejuni antisera demonstrated the applicability of this approach for epidemiological studies. We found antigenically similar strains in family outbreaks, antigenic differences in strains of different origin, new combinations of cross reactions not seen in strains used in immunization, antigenically "new" strains not reacting with these antisera, and the dominance of a few antigenic types among the isolates.

Agglutination Tests↗
PubMed1982

Comparative study among complement fixation, serum agglutination and Rose Bengal plate tests in the serodiagnosis of bovine brucellosis.

The complement fixation test (CFT) based on the 50 per cent hemolytic end point technique was applied to the diagnosis of bovine brucellosis in a comparative study involving the plate agglutination test (PAT), the tube agglutination test (TAT) and the Rose Bengal plate test (RBPT). Among 180 bovine sera that were examined the CFT was able to reveal significant titres in sera that gave low agglutinating titres. Some sera with agglutinating titres between 1 in 50 and 1 in 100 did not give a titre in the CFT. The results show that the CFT is useful for bovine brucellosis diagnosis and may be used after sera screening with PAT and RBPT.

Agglutination Tests↗