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Naturally occurring agglutinins against trypanosomatid flagellates in the haemolymph of insects.

In vitro studies of the behaviour of the trypanosomatid flagellates Trypanosoma brucei and Leishmania hertigi in the presence of cell-free haemolymph of locusts, Schistocerca gregaria and cockroaches, Periplaneta americana revealed the presence of parasite agglutinins. The range of normal values of agglutination titres was 2(-4) to 2(-13). Physico-chemical treatment of haemolymph indicated that these agglutinins are protein or glycoprotein in nature and are only partially affected by heat treatment below 65 degrees C, at which temperature incubation of haemolymph for 30 min abrogated all agglutination. Agglutination was not dependent on the presence of Ca2+ or Mg2+. Prior injection of locusts and cockroaches with T. brucei and L. hertigi significantly increased agglutinin titres between Days 4 and 6 in cockroaches (P less than 0.05) and from Days 2 to 4 when L. hertigi was inoculated into locusts. The induced differences in titres observed in locusts infected with T. brucei were not significant. Lysozyme levels were significantly increased after inoculation of T. brucei into cockroaches compared with placebo-inoculated and uninoculated controls. L. hertigi inoculation produced significant increases in lysozyme levels compared with controls between Days 1 and 7 in locusts and 3 to 6 in cockroaches. These studies indicate that, at least in easily manipulated model systems, induced responses to intrahaemocoelic inoculation to trypanosomes and Leishmania can occur. As far as we are aware this is the first report of an induced response of an insect to such important parasites. The possibility that induced responses in natural vector to this parasites occurs requires investigation.

Adsorption↗

The relation of agglutinins to antigenic variation of Trypanosoma lewisi.

During the course of infection in the rat, Trypanosoma lewisi produces 2 antigenic variants: the 1st represents the initial, reproducing population of cells; and the 2nd the nonreproducing, ablastin-inhibited adult population. The specificities of the agglutinins elicited by the variants were studied by adsorption and agglutination methods and the newer immunoelectroadsorption technic. It was found that the reproducing variant has a surface antigen that reacts with the agglutinin specific for the adult variant, but this antigen does not become immunogenic until transformation to the adult variant occurs. It was also found, with fractions of immune sera obtained by gel filtration, that the agglutinin specific for the reproducing variant is IgG and that specific for the adult variant, IgM. The antigenic variants of pathogenic and nonpathogenic trypanosomes are compared, and the roles of trypanocidal and ablastic antibodies in the induction of antigenic variation are discussed.

Adsorption↗

Human lymphocyte agglutinins in Tursiops truncatus (bottlenose dolphin).

A naturally occurring heterophile agglutinin directed against human erythrocytes and lymphocytes is present in the serum of the marine mammal, Tursiops truncatus (Bottlenose dolphin). Differential specificity was demonstrated with the use of absorption techniques that showed at least 3 separate specificities directed against erythrocytes, T cells, and B cells, of which the B cell agglutinin was in the highest titer. Isolation techniques employing ion exchange and affinity chromatography have shown these agglutinins to be of the IgM class. Agglutinin activity is lost when lymphocytes are treated with pronase, suggesting that the surface receptor is protein or protein associated.

Agglutination Tests↗

Interpretation of the Widal test in the diagnosis of typhoid fever in Bangladeshi children.

The value of a Widal test in diagnosing typhoid fever was assessed in children aged between 1 and 10 years in Bangladesh. The test was done on sera specimens from 300 healthy school children, 100 patients with non-typhoidal febrile illness and 150 bacteriologically proven cases of typhoid fever. Salmonella typhi O and H agglutinin titres > 1:80 and > 1:160 were considered to be significant with 88% sensitivity and 98% specificity, respectively. Among the bacteriologically proven cases, 11.3% showed no response to either agglutinin, and in another 17.3% of cases there was no response for TO agglutinin. This study suggests that in children in an endemic area a positive Widal test is of considerable importance in diagnosing typhoid fever. Furthermore, negative results should be interpreted with caution and both the agglutinins must be considered equally important. Reliance on somatic (TO) antigen only will result in missed diagnosis.

Agglutination Tests↗

Different agglutinability of fibroblasts underlying various precursor lesions of human uterine cervical carcinoma.

Fibroblasts underlying human uterine cervical dysplasia, carcinoma in situ, and invasive carcinoma are agglutinable by concanavalin A (Con A) but not by wheat germ agglutinin, except at very high concentration. Studies with low levels of Con A show that maximal agglutination is obtained with fibroblasts from invasive carcinoma, while the fibroblasts underlying dysplasia give minimal agglutination reactions. Fibroblasts underlying carcinoma in situ give agglutination reactions halfway between those obtained with fibroblasts underlying dysplasia and invasive carcinoma. An epithelial-like cell line obtained from a case of dysplasia shows agglutinability by Con A very similar to that obtained with fibroblasts underlying dysplasia. These epithelial-like cells are also not agglutinable by wheat germ agglutinin. Treatment of the cervical cells, both epithelial and fibroblasts, with neuraminidase leads to slight increase in agglutination by both Con A and wheat germ agglutinin. Marked increase in agglutination is not obtained even after treatment with high concentration of neuraminidase (10 units/10(6) cells). Marked agglutinability, however, is observed after trypsin treatment. The results suggest that, while the fibroblasts obtained from normal cervix are not agglutinable by Con A, surface alterations necessary for Con A-specific agglutination exist in fibroblasts during the early stage of development of uterine cervical epithelial neoplasia (dysplasia) and increase with the progression through carcinoma in situ to invasive carcinoma. Loss of cell surface sialic acids may result in a slight increase in agglutinability, but some other mechanism(s) is likely to be involved in alteration of surface properties that lead to marked agglutinability of the human uterine cervical cells obtained from cancer precursor lesions.

Agglutination↗

Significance and value of the Widal test in the diagnosis of typhoid fever in an endemic area.

The diagnostic value of the Widal test was assessed in an endemic area. The test was done on 300 normal individuals, 297 non-typhoidal fevers and 275 bacteriologically proven cases of typhoid. Of 300 normal individuals, 2% had an H agglutinin titre of 1/160 and 5% had an O agglutinin titre of 1/160. On the basis of these criteria a significant H and/or O agglutinin titre of 1/320 or more was observed in 93-97% of typhoid cases and in only 3% of patients with non-typhoidal fever. Of the sera from typhoid cases which gave a significant Widal reaction, the majority (79.9%) showed increases in both H and O agglutinins and 51 of 234 (21.8%) of these sera were collected in the first week of illness. The significance and implications of these findings are discussed.

Agglutination Tests↗

Heating unsaturated fatty acids in air produces hemagglutinins.

When mono-unsaturated fatty acids are heated in air, they form hemagglutinins. When the double bond is delta-6,7 or delta-9,10, the titer is higher than for delta-11,12. Stearic acid does not become a hemagglutinin on heating. Hydroxy-monounsaturated fatty acids, ricinoleic (cis-12-OH-delta-9) and ricinelaidic (trans-12-OH-delta-9) are not hemagglutinins unless they are heated. Oleic acid (delta-9-octadecenoic acid, OA) has a very low agglutination titer but lyses red cells at higher concentrations. Rabbit and rat erythrocytes (RBC) give the highest titers but RBCs of other species are also agglutinated. OA was chosen for further study. Its specific titer against rat RBCs increases with time of heating in air. Thin-layer chromatography (TLC) and mass spectroscopy (MS) show that higher molecular weight compounds are formed and that activity is associated with these materials. Synthetic (oxidation of oleic acid with tert-butyl peroxide) and commercial preparations of oleic acid dimers (Emery and Unichema) and a commercial preparation of oleic trimer mixed with polymer (Emery) have high hemagglutination titers against rat erythrocytes. A cyclic, long-chain dicarboxylic acid, 5(6)-carboxy-4-hexyl-2-cyclohexene-1-octanoic acid (Westvaco) gives a very low titer unless heated and no lysis. Sialidase treatment of the red cells increases the titer. Removal of cations does not alter the titer but addition of Ca2+ or Mg2+ lowers the titer. Light microscopy was used to characterize and visualize the agglutination process with rat RBCs. Agglutination without lysis or fusion is observed for low concentrations of heated oleic acid and C-18 dimers and trimer-polymer preparations, and no large vesicles are seen. We conclude that the oligomeric fatty acids with two or more hydrophobic chains of seven or more carbons are agglutinins at physiological pH. Agglutination by dimer may be the result of the its two hydrophobic side chains inserting into adjacent RBC membranes or the result of dimer inserting completely into RBC membranes and altering their properties. The carboxyl groups may also play a role in the process by interacting with polar headgroups in the RBC membrane.

Animals↗

The Widal test in the diagnosis of typhoid fever in the transvaal.

We analysed the results of the Widal test in the northern and eastern Transvaal in relation to bacteriologically confirmed cases of typhoid fever, patients suspected of having the disease, febrile patients without typhoid fever and healthy individuals. Titres of 1:200 or greater for either H or O agglutinins were recorded for 75,2% of patients with bacteriologically proven typhoid fever, 4,6% of healthy subjects residing in an endemic area and 7,5% of patients presenting with non-thyroid fevers. Age, sex and region were found to affect the percentage of positive tests recorded. Despite these failings, the Widal test was found to be of value in the diagnosis of typhoid fever. The concept of a diagnostic titre was considered unreliable, but considered in conjunction with the clinical picture, O or H agglutinin titres of 1:200 or more may be regarded as strong presumptive evidence of typhoid fever.

Adolescent↗

A serum haemagglutinating property dependent upon polycarboxyl groups.

A serum agglutinin reactive with red cells in the presence of polycarboxyl groups is reported. It is likely that this represents an additional example of the type of agglutinin previously described as agglutinating red cells in the absence of ionized calcium. Experimental evidence is presented indicating that it is free polycarboxyl groups that potentiate agglutination and that any metal ion, such as calcium, capable of chelating with these groups will prove to be inhibitory.

ABO Blood-Group System↗

[Serological studies of human Yersinia enterocolitica infections].

Sera of 1283 patients from hospitals and medical centers of Wrocław were examined for Y. enterocolitica antibodies. In 29% examined sera anti-Y.enterocolitica antibodies of titer 1:40 and greater were noted. The agglutinins against serotype IA(3) were in 82.5%, against V(9) in 8.6% and against both serotypes mentioned above in 8.8%. In the group of sera positive for serotype IA 70.2% of sera gave positive reaction using antigen made from the humans strains and 9.1% using antigen prepared from swine Y.enterocolitica isolate. Patients with the positive titer of agglutinins against Y.enterocolitica in their sera mainly shoved the symptoms of gastroenterocolitis (54.8%) and arthritis (14.5%). The highest percentage reactions was in children aged 7-14 years (47.3%) whereas in adults it was lover (28.8%).

Adolescent↗

A rapid cold agglutinin test in Mycoplasma pneumoniae infection.

A definite diagnosis of Mycoplasma pneumoniae infection is currently based on cultural method or complement fixation test which is usually retrospective. A rapid cold agglutinin test was developed to determine its value on the early diagnosis of M. Pneumoniae infection. One hundred and thirty patients with pneumonia aged between 5 and 14 years were studied. Blood specimens from all the patients were collected for rapid cold agglutinin test, cold hemagglutination test, and complement fixation test. Thirty patients showed positive, rapid cold agglutinin test. All the patients with positive rapid cold agglutinin test had higher (greater than or equal to 1:32) cold agglutinin titers which were simultaneously performed. The rapid cold agglutinin test had 100% sensitivity and 97% specificity when a cut-off criterion was set at cold agglutinin titer greater than or equal to 1:64. Twenty-five of the 130 cases were serologically proven to have M. pneumoniae infection using complement fixation test or/and cold agglutinin titer. M. pneumoniae was a major cause (21/28) in cold agglutinin-positive pneumonic patients. The positive predictive value of the rapid cold agglutinin test is 70% (21/30). Only 28% (7/25) of the patients with M. pneumoniae infection were diagnosed at acute stage with serological method. We conclude that the rapid cold agglutinin test is of much value in the early detection of M. pneumoniae infection in office or hospital practice in children with pneumonia.

Adolescent↗

Goat sperm membrane: lectin-binding sites of sperm surface and lectin affinity chromatography of the mature sperm membrane antigens.

The cell surface glycoproteins of goat epididymal maturing spermatozoa have been investigated using lectins as surface probes that interact with specific sugars with high affinity. Concanavalin A (ConA) and wheat-germ agglutinin (WGA) showed high affinity for mature cauda epididymal sperm agglutination, whereas RCA2, kidney beans lectin and peanut agglutinin caused much lower or little agglutination of the cells. The mature sperm exhibited markedly higher efficacy than the immature caput epididymal sperm for binding both ConA and WGA, as evidenced by sperm agglutination and the binding of the fluorescence isothiocyanate (FITC)-labelled lectins. FITC-ConA binds uniformly to the entire mature sperm surface whereas FITC-WGA binds to the acrosomal cap region of the head. The FITC-RCA2 mainly labelled the posterior head of mature cauda sperm. However, no WGA-specific glycoprotein receptors could be detected in sperm plasma membrane (PM) by WGA-Sepharose affinity chromatography. The data implied that the epididymal sperm maturation is associated with a marked increase in the ConA/WGA receptors and that WGA receptors may be glycolipids rather than glycoproteins. Analysis of the ConA receptors of cauda sperm PM identified by ConA-Sepharose affinity chromatography and subsequent resolution in SDS-PAGE demonstrated the presence of five glycopolypeptides of different concentrations (98, 96, 43, 27 and 17 kDa) of goat sperm membrane. The immunoblot of these ConA-specific glycopeptides with anti-sperm membrane antiserum showed that 98- and 96-kDa receptors are immunoresponsive.

Agglutination↗

The occurrence of leptospiral antibodies in rural inhabitants of Argentina.

Sera collected during surveys of presumably healthy rural inhabitants of the Provinces of Corrientes and Neuquén, Argentina, were examined for serological evidence of leptospirosis. Significant antibody levels (1:100 or greater) were found in 8.7 per cent of 1,029 sera from residents of Corrientes Province. The most frequent reactions occurred against the serotypes australis, hebdomadis group, pomona, and icterohaemorrhagiae. The predominance of antibodies to the Australis group in the country is new and suggests the emergence of leptospirosis in an unrecognized animal reservoir host. Out of 706 sera collected from rural school students and sera from 71 adults in the Province of Neuquén, only 4 (0.5%) showed leptospiral agglutinin in the microscopic agglutination test and these were only at a 1:100 serum dilution. The higher percentage of reactors in the Corrientes population appears to reflect a more favorable environment and a greater risk of infection.

Adolescent↗

Establishment of a simple system to analyse the molecular interaction in the agglutination of Saccharomyces cerevisiae.

Saccharomyces cerevisiae a-agglutinin, which is involved in mating and covalently anchoring to the cell wall, consists of two components, Aga1p and Aga2p, whose syntheses are individually regulated. To facilitate the analysis of the protein-protein interaction on agglutination between a- and alpha-agglutinins, the construction of a yeast strain (MATa) with the functional protein prepared by genetic fusion of Aga1p- and Aga2p-encoding genes and by the expression system using the UPR-ICL promoter derived from the n-alkane-assimilating yeast, Candida tropicalis, which is functional under the condition of lower glucose concentration was tried and the agglutination ability of the constructed strain was evaluated with a yeast strain (MATa) which expressed AGalpha1 encoding alpha-agglutinin under the control of the same promoter. The genes were integrated into the yeast chromosomes. Cell agglutination between both (MATa) strains was observed microscopically when these two strains were mix-cultured to a glucose-decreased concentration. The agglutination was further confirmed by the sedimentation test and by the quantification using a filter. These results proved that the constructed Aga1p-Aga2p fusion protein was enoughly functional for the interaction with the Agalpha1 protein, and that this phenomenon occurred dependent on glucose concentration, but independent of the peptide pheromones secreted by the cells of the opposite mating types. Using this system, the role of two disulphide linkages between Aga1p and Aga2p on the binding activity between Aga2p and Aga1p was first evaluated. Under the treatment by the SH-compound (dithiothreitol), in which Agalpha2p is easily released into the medium from the intact cell surface, the Aga1p and Aga2p fusion protein was a good tool to make clear the role of the disulphide linkages. As a result, the linkages had a significant effect on not only the assembly but also the binding activity. The novel and simple system described here may further facilitate the study of molecular interaction in agglutination.

Alkanes↗

Changes in surface properties of normal and transformed cells caused by tunicamycin, an inhibitor of protein glycosylation.

Normal and virally transformed mouse (3T3) and human (WI-38) cells were treated with tunicamycin, an inhibitor of lipid-carrier-dependent glycosylation of proteins. Incubation of cells with tunicamycin (1 microgram/ml) caused detachment and death of simian virus 40- and polyoma-transformed cells within 24 hr; these effects were not seen with nontransformed cell lines. However, the proliferation of 3T3 cells was inhibited by tunicamycin and, after a few days, a distinct change from an epithelioid to an abnormally elongated shape was observed. Both inhibition of growth and the morphological changes were reversible. A marked decrease in concanavalin A agglutinability was observed in virally transformed cells treated with tunicamycin (0.5 microgram/ml), but agglutination by wheat germ agglutinin or soybean agglutinin was unaffected. Analysis of biosynthetically labeled proteins showed that a high-molecular-weight protein, presumed to be related to fibronectin, is markedly reduced in the medium of cells cultured in the presence of tunicamycin. These results suggest that tunicamycin interferes with the insertion or function of one or more cell-surface glycoproteins. Such cell-surface changes could affect a number of cellular properties, including attachment, cell shape, and agglutinability by some lectins.

Agglutination Tests↗

[Comparative studies of agglutinin formation in poultry experimentally infected by various routes with Salm. gallinarum-pullorum].

It has been established that the immunologic response in birds is directly associated with the way of infection. Parenteral treatment has proved to be the most effective route in establishing the highest degree of titers as early as the 6th day following injection -- 1:754. Using the intravenous route of infection the titers are found on the eighth day -- 1:580; at the intramuscular infection as well as the accomplished via subcutaneous injection the titers are observed on the tenth day --1:364. At oral infection the peak in the agglutination titer curve is noted on the twentieth day -- 1:383 (comparatively later); it has been found that the titers in this case remain at one and the same level for a much longer period of time.

Administration, Oral↗

Serosurvey on the presence of leptospiral agglutinins in humans in Northern Italy.

The article reports data concerning a serosurvey carried out in the province of Gorizia as a part of a research project sponsored by the National Research Council (CNR) on the epidemiological status of leptospirosis in Northern Italy. Microagglutination tests have been carried out on sera taken from randomly chosen healthy people and from humans exposed to occupational hazards, at a representing sample size for each category. The results have shown 8.29% agglutinin prevalence in healthy people, serovars bratislava, sejroe and canicola being predominant. Prevalence agglutinin rates were higher in meat workers (11.76%), sweepers (16.66%) and breeders (40%); in the latter category antibodies to Leptospira hardjo have been found out; this is the first reported instance of human contamination by L. hardjo in Italy.

Agglutination Tests↗