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PubMed1983

Sterilization by vas occlusion without transection does not reduce postvasectomy sperm-agglutinating antibodies in serum. A randomized trial of vas occlusion versus vasectomy.

The influence of transection of the vasa on the increase in sperm-agglutinating activity in serum after vasectomy was investigated in a prospective randomized study. Sixty-eight males requesting vasectomy were allocated to either of two groups: vas occlusion by tantalum clips without transection of the vasa, or conventional vasectomy by transection and ligation. Sperm-agglutinating antibodies were determined by a micro-agglutination test before and 6 months after vasectomy or vas occlusion. A significant increase in sperm-agglutinating activity in serum after sterilization was found in both groups, but there was no intergroup difference.

Adult↗
PubMed1975

Lack of correlation between growth characteristics, agglutinability by plant lectins and the malignant phenotype.

Wheat germ agglutinin and Concanavalin A were found to agglutinate a variety of normal hamster cells as well as a number of lines of transformed or tumor cells. The normal cells included preparations from embryos and neonatal organs, and the spontaneous line, BHK-21 C13. In order to explore more fully the situation in regard to the BHK cells, three sublines were isolated and studied. A "flat revertant" selected by FUdR treatment grew to diminished saturation density and failed to produce colonies in soft agar in contrast to the parent line, which did. Yet, it was only minimally less tumorigenic and less agglutinable than the parent line. Lines derived from one and four consecutive in vivo tumor passages showed increased tumorigenicity and growth in soft agar when compared to the parent line. Although the first passage line showed increased saturation density, the saturation density of the fourth passage line was similar to or less than that of the parent cells. Agglutinability of these lines was not significantly increased. These results indicate that, in contrast to widely accepted beliefs, tumorigenicity may correlate poorly with growth characteristics and agglutination by plant lectins.

Agglutination↗
PubMed1986

Secreted agglutinability-masking factors in Issatchenkia scutulata var. scutulata.

The agglutinability-masking factors (AMFs) of a and alpha mating types of Issatchenkia scutulata var. scutulata were prepared from culture fluids. AMFs masked the agglutinability of opposite mating-type cells sex-specifically, just like agglutination substances responsible for sexual cell agglutination. a AMF adsorbed to alpha cells was eluted by incubating the cells at 60 degrees C for 10 min. alpha AMF was prepared directly from culture fluids of alpha cells by DEAE-cellulose ion exchange chromatography. The active part of the AMFs is thought to be a peptidyl moiety because of the sensitivity to subtilisin. The pretreatment of cells with AMF of the opposite mating-type was shown to promote zygote formation. alpha AMF slightly inhibited growth in a cells but not in alpha cells, while a AMF did not show any growth-inhibitory effect on either a or x cells.

Agglutination↗
PubMed1984

Selective inhibition of transition from sexual agglutination to zygote formation by ethyl N-phenylcarbamate in Saccharomyces cerevisiae.

Effects of ethyl N-phenylcarbamate (EPC) on the mating reaction of Saccharomyces cerevisiae were studied, with special attention on the effect on the alpha pheromone action. EPC inhibited zygote formation at a concentration which promoted induction of sexual agglutinability. EPC enhanced agglutinability induction by alpha pheromone, but inhibited alpha-pheromone-induced formation of large pearshaped cells in a mating type. The enhancement of agglutinability induction was accompanied with increased production of a agglutination substance and inhibition of alpha pheromone inactivation. EPC arrested the cell cycle of a cells probably in the step controlled by CDC19, CDC35, cAMP etc., just before the step controlled by CDC28, alpha pheromone etc.

Agglutination↗
PubMed1980

Agglutination kinetics of normal and diabetic adult rat hepatocytes.

This paper describes Concanavalin A-induced agglutination of viable rat hepatocytes obtained by collagenase perfusion from normal and streptozocin-treated diabetic rats. An irreversible cell-to-cell agglutination model is proposed to explain hepatocyte flocculation. The rate of agglutination is concentration dependent with respect to Concanavalin A, and is twice as fast in normal as compared to diabetic hepatocytes. Sticking probability constants ranging from 18.48 x 10(7) to 4.6 x 10(7) cm-1 . hepatocyte-1 and 8.32 x 10(7) to 2.31 x 10(7) cm-1 . hepatocyte-1 are calculated as a measure of agglutination for normal and diabetic cells respectively. These findings suggest that the cytoplasmic membranes of normal cells possess agglutinin receptors which are more numerous and/or differently arranged than those existing in diabetic cells.

Agglutination↗
PubMed1984

Lectin-induced agglutination of trophozoites of different species and strains of Entamoeba.

In vitro agglutinability of trophozoites of three Entamoeba histolytica strains, cultivated under axenic conditions in the presence of concanavalin A (Con A), was shown to be related to the degree of their pathogenicity for experimental animals and of the concentration of Con A. Seven strains of E. invadens tested also agglutinated in the presence of Con A, and the degree of agglutination was proportional to the concentration of the lectin. Three strains of E. histolytica-like "Laredo-type" amebae, a strain of E. terrapinae, and a strain of E. moshkovskii agglutinated very slightly, only in the presence of the highest concentration of Con A tested.

Agglutination↗
PubMed1985

Cell fusion and cell agglutination: enhancing effect by a combined use of lectin and polycation.

The technique efficient for hybridization of mammalian cells was improved by combining a procedure of cell agglutination of cells pretreated with a combination of lectin and polycation and the procedure of conventional polyethylene glycol (PEG) -induced cell fusion. The agglutinability of cells treated with lectin, polycation, and both of them was tested. The effects of these agglutinogens on the hybridization frequencies of cells were also compared. The appearance rate of hybrid colonies was found to be correlated to the extent of cell agglutination. The pretreatment with a combination of lectin and polycation induced the highest degree of cell agglutination and the highest frequency of resulting hybridization. The enhancing effect by the pretreatment with a combination of these agglutinogens on the hybridization frequency was confirmed through experiments on the crosses of several cell types including nuclear fraction (karyoplast).

Agglutination↗
PubMed1994

Re-evaluation of the Widal agglutination test in response to the changing pattern of typhoid fever in the highlands of Papua New Guinea.

In 1992 it was decided to re-evaluate the Widal slide agglutination test as a rapid diagnostic test for typhoid fever in Papua New Guinea. This was in response to an apparent increase in the number of false positive Widal slide agglutinations occurring using an O cut-off titre greater than or equal to 40 which was previously shown to be appropriate in 1987. The results of the re-evaluation indicated that the Widal test using a diagnostic cut-off titre of > or = 40 lacked specificity and was no longer appropriate for this population. A new O antibody titre of > or = 160 was recommended as a diagnostic titre for typhoid fever in PNG. The fall in the specificity of the Widal slide agglutination test over the five-year period between the initial assessment and the re-evaluation is due to an increase in general population antibody levels caused by the changing pattern of typhoid in the community. Before 1987 typhoid fever occurred as sporadic, isolated outbreaks and most people living in the highlands of PNG were immunologically naive. By 1992 typhoid fever had become a well-established endemic disease and many more people had been exposed to Salmonella typhi and as a result developed antibodies. We have been able to demonstrate clearly a remarkable change in the immune status of the community, in which the proportion of healthy individuals with a Widal tube O agglutination titre of 40 or more rose from 0 to 56% in the short span of five years.(ABSTRACT TRUNCATED AT 250 WORDS)

Agglutination Tests↗
PubMed1981

Postcoital tests and sperm-agglutinating antibodies in men.

Postcoital tests (PCTs) were examined from couples where the husbands had circulating head-to-head (H-H) or tail-to-tail (T-T) sperm-agglutinating antibodies. The results were compared with findings in couples without antibodies. The presence of H-H sperm-agglutinating antibodies did not interfere with the outcome of the PCT. High serum titers of T-T sperm-agglutinating antibodies, the presence of such antibodies in the seminal fluid, and/or a strong or complete autoagglutination in the husband's ejaculate markedly reduced the number of invading spermatozoa as well as their survival in the PCT. A moderate titer of T-T sperm-agglutinating antibodies was also reflected in the PCT but low titers did not have any influence on the results.

Autoantibodies↗
PubMed1982

Lectin-mediated agglutination of liposomes containing glycophorin. Effect of acyl chain length.

Glycophorin from human erythrocytes has been incorporated into liposomes of dimyristoylphosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC) and distearoylphosphatidylcholine (DSPC). The thermal properties of unsonicated liposomes with glycophorin/lipid molar ratios up to 4.10(-3) have been studied by differential scanning calorimetry and the numbers of lipids withdrawn from participation in the gel-to-lamellar phase transition were found to be 42 +/- 22 (DMPC), 197 +/- 28 (DPPC) and 240 +/- 64 (DSPC). The initial rates of agglutination of sonicated liposomes with glycophorin/lipid molar ratios up to 4.10(-3) by wheat germ agglutinin in the concentration range 0-7 microM have been measured over a range of temperature. Below the gel-to-lamellar phase transition (Tc) the rates of agglutination increase with acyl chain length in the sequence DMPC less than DPPC less than DSPC. Agglutination is found to be second order in liposome concentration and is completely reversed on saturation of the wheat germ agglutinin-binding sites by N-acetylglucosamine. Agglutination rates decrease with increasing temperature below Tc and are largely independent of temperature above Tc. The results are discussed in relation to the clustering of glycophorin in the phospholipid bilayers and its effect on binding and subsequent interliposomal bridge formation by wheat germ agglutinin.

Agglutination↗
PubMed1984

Schistosoma mansoni: agglutination of sporocysts, and formation of gels on miracidia transforming in plasma of Biomphalaria glabrata.

The resistance or susceptibility of Biomphalaria glabrata strains to strains of Schistosoma mansoni, the human blood fluke, are evidenced by the responses of snail hemocytes to sporocysts of the schistosome, both in vivo and in vitro. It is now reported that living sporocysts of the PR1 strain of S. mansoni agglutinate in the plasma of all tested strains of B. glabrata, in contrast to fixed sporocysts which agglutinate only in plasma from resistant snail strains. The agglutinating activity in resistant plasmas is not divalent cation dependent, and was not inhibited by the 26 carbohydrates and four amino acids tested. In addition, the observation that gelatinous deposits develop on transforming miracidia-sporocysts in B. glabrata plasmas is also reported. Both the agglutination and gel-formation phenomena may facilitate recognition of, and attacks on, sporocysts, thereby contributing to susceptibility and resistance in this host-parasite system.

Agglutination↗
PubMed1989

Agglutination of Legionella pneumophila by antiserum is accelerated in an ultrasonic standing wave.

The agglutination of Legionella pneumophila (LP) by diluted anti-LP whole rabbit serum has been compared in conventional microwell plates and in capillary containers where the suspension was exposed to a 1 MHz ultrasonic standing wave field. A positive reaction in the standing wave field was detected as a series of cell agglutinates, separated by half an acoustic wavelength (0.75 mm), distributed along the length of the capillary. Agglutination occurred in 60 s or less with ultrasound, while the incubation period for a positive microwell test was often of the order of hours. At a given antiserum concentration, ultrasound-induced agglutination occurred at LP concentrations two-fold lower than those giving a positive result in the microwell plate assays. At cell concentrations near the lower limit for detection of a positive result in the microwell plates a positive reaction was detected in the standing wave field at antiserum concentrations up to 500-fold lower than those forming visible precipitates in the conventional assay.

Agglutination↗
PubMed1985

Measurement of concanavalin A induced agglutination of follicular, luteal and atretic rat granulosa cells.

To determine changes in the surface membrane of granulosa cells related to follicular atresia and luteinization, their agglutination behavior with Concanavalin A has been studied by quantitative spectrophotometry. As compared to the granulosa cells of normal Graafian follicles, the agglutination rate (delta A546/5 min) and final level of agglutination significantly increased in atretic and decreased in luteinized cells indicating the increase of Con A binding sites with atresia and decrease with luteinization. Treatments of granulosa cells with EDTA and trypsin enhanced agglutination of follicular and luteal cells but had no effect on atretic granulosa cells.

Agglutination↗
PubMed1977

Differences in agglutinability of adult and fetal human fibroblasts using phytohemagglutinin.

Whereas Concanavalin A (Con A) and Wheat Germ Agglutinin (WGA) detect differences in the agglutinability of transformed, established and secondary cultures, Phytohemagglutinin (PHA) detects differences between cultured adult and fetal human fibroblasts. Adult cells agglutinate with PHA to the same extent as transformed cells, whereas fetal cells show significant agglutination only after trypsinization. Differences in cell size, growth rate, surface architecture or binding of fluorescent PHA could not be demonstrated between adult and fetal cells. Although the basis for this apparent difference in agglutinability remains unknown, it is the first demonstration that fetal cells (even after prolonged in vitro culture) retain at least some surface properties not shared by adult or transformed cells.

Adult↗
PubMed1988

Jacalin: isolation, characterization, and influence of various factors on its interaction with human IgA1, as assessed by precipitation and latex agglutination.

An IgA1-specific lectin, Jacalin, was isolated from dried seeds of the jackfruit, Artocarpus integrifolia, by affinity binding to IgA1-Sepharose and elution with D-galactose. Jacalin is a glycoprotein with two non-covalently bound subunits (15 and 18 K). Interactions between Jacalin and human Igs were studied by precipitation in gel and in solution, and by agglutination of IgA1-coated latex by Jacalin. Jacalin precipitated only with IgA1-containing samples, including monomers, polymers, monoclonal, polyclonal and secretory IgA1, but not IgA2 of both A2m(1) and A2m(2) allotypes, nor with IgG1, 2, 3 and 4, IgM, IgD, and IgE; after neuraminidase treatment, only IgA1 and IgD were precipitated. Jacalin had a relatively broad pH range of activity in both precipitation and agglutination of IgA1-latex. Bivalent metal cations (Ca, Mg, Mn, Cu, Zn, Co, Cd), EDTA, Triton X-100, Tween-20, Na deoxycholate and ionic strength did not influence these reactions. Na dodecylsulphate, guanidine and urea inhibited the reactions whereas NP-40 rather enhanced them. Among 39 types of sugar tested, 10 displayed inhibitory activity, decreasing in the following order: p-nitrophenyl-alpha-D-galactopyranoside, 1-O-methyl-alpha-D-galactopyranoside, D-melibiose, p-nitrophenyl-beta-D-galactopyranoside, GalNAc, stachyose, 1-O-methyl-alpha-D-mannopyranoside, D-galactose, D-galactosamine and 1-O-methyl-alpha-D-glucopyranoside. IgA1, treated with neuraminidase or not, but not the other human Igs, was also an excellent inhibitor of agglutination, being more powerful than the best sugars studied. Only neuraminidase-treated IgD was also inhibitory, but less so than IgA1. Jacalin preferentially bound to alpha-linked non-reducing D-galactose. The configuration of OH-groups at C-2, C-4 and C-6 of D-galactose was important for the reaction. Jacalin recognizes terminal Gal beta 1-3GalNac-, as in the IgA1-hinge, and/or GalNAc-, but not Gal beta 1-4GlcNAc-, nor Gal beta 1-6GlcNAc-, nor their sialylayted extensions. Latex agglutination and its inhibition assay are particularly well suited for the study of these lectin-glycoprotein interactions.

Agglutination↗
PubMed1987

Establishment and characterization of a human hybridoma secreting monoclonal antibody with high titers of sperm immobilizing and agglutinating activities against human seminal plasma.

Peripheral blood lymphocytes isolated from an infertile woman possessing strong sperm immobilizing and agglutinating antibodies were stimulated by culturing with poke-weed mitogen (PWM) and spermatozoa from a healthy donor for 5 days. The stimulated lymphocytes were fused with mouse myeloma NS-1 by PEG-1000. Fused growing hybrid cells were observed in 58 of 96 wells, and 22 of these showed the production of human immunoglobulin. Among the 22, one hybridoma clone (H6-3C4) was found to produce human IgM (lambda) with strong sperm immobilizing and agglutinating activities. The supernatant from the culture medium contained approximately 1.5 microgram IgM/ml and the antibody titers were 5000 SI50 units on sperm immobilization and 1:1600 dilutions on sperm agglutination. The hybridoma H6-3C4 has continuously produced high titers of antibody exhibiting sperm immobilizing and agglutinating activities over 8 months and contains chromosomes of acrocentric type from mouse and metacentric type from human. The monoclonal antibody (Mab) H6-3C4 reacted specifically to human seminal plasma, ejaculated spermatozoa and male accessory gland but not to testis, any other somatic tissues, or secreted fluids tested. Immunofluorescence staining indicated that the antigen corresponding to Mab H6-3C4 was present over the surface of ejaculated spermatozoa. The binding of Mab H6-3C4 to human spermatozoa was blocked by the serum of the patient from whom the lymphocytes were obtained for cell fusion.

Adult↗
PubMed1987

Brain lectin-mediated agglutinability of dissociated cells from embryonic and postnatal mouse brain.

Brain extracts contain a soluble lectin which enables the agglutination of dissociated mouse brain cells via saccharidic receptors. The ability of the brain cells to be agglutinated depends on their stage of development in vivo. Furthermore, after birth, the mechanism of the lectin-promoted agglutination is complicated by the appearance of a self-aggregation of the dissociated cells. Lactose and galactosides are inhibitors of lectin-mediated agglutination as well as of the dissociated cells' self-aggregation.

Agglutination↗
PubMed1991

Comparison of staphylococcal co-agglutination with other assays for rapid diagnosis of rotavirus infection in humans, calves and piglets.

Co-agglutination was used for rapid diagnosis of rotavirus infection. Staphylococcus aureus Cowan I sensitized with rabbit antiserum to rotavirus demonstrated the presence of this virus in stools of children, calves and piglets with clinical signs of diarrhea. A total of 415 fecal samples were examined by the co-agglutination test and the results were compared with those of ELISA, electrophoresis in polyacrylamide gel and latex agglutination. The co-agglutination test, when compared to these three methods, presented a correlation which varied between 87.2 and 94.2%.

Adenoviridae↗