Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AGGLUTINATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources
PubMed1993

Investigation of latex agglutination with different immunoglobulin classes of antibodies by a scanning electron microscopy.

The conformation of passive latex agglutinations was investigated by a scanning electron microscopy. The complexes of 2,4-dinitrophenyl group (DNP) and bovine serum albumin (BSA) coated microspheres were incubated with monoclonal antibodies to DNP belonging to different classes of immunoglobulins. Examination with a scanning electron microscope demonstrated that the connectors between microspheres, agglutinated with IgE antibody, tended to take long filamentary forms; whereas the connectors of microspheres, agglutinated with IgG or IgM antibodies, formed shorter filaments. These phenomena were confirmed by the agglutination reactions of tick suspension-coated latex and allergic patients' sera. This morphologic difference is probably attributable to the unusually high elasticity of IgE antibody and is an evidence of the high biologic activity of the IgE antibodies. We assumed the processes of latex agglutination whereby the filamentary substances would develop, expecting that the processes could be models of in vivo and in vitro agglutination of cells.

Animals↗
PubMed1994

Elevated agglutination titres in plasma of Biomphalaria glabrata exposed to Echinostoma paraensei: characterization and functional relevance of a trematode-induced response.

Production of elevated haemolymph agglutination titres by Biomphalaria glabrata following exposure to Echinostoma paraensei miracidia was investigated, to characterize this parasite-induced response and to understand its functional relevance. Both the dose of infection (1, 10 or 100 miracidia per snail) or the number of separate exposures to infection (between one and three, over a 4 or 8 day interval) were varied, and assuming a threshold dosage (10 miracidia per snail or higher) was exceeded, titres of juvenile snails peaked at 8-16 times the values for unexposed control snails, regardless of the exposure regimen. Adult snails, which are relatively refractory to infection, have slightly higher resting titres than juveniles, but exhibit only a 2- to 4-fold increase in titre following exposure. Juveniles exposed to infection but lacking demonstrable infection had lower titres than snails with confirmed infections. Exposure to infection increased heterogeneity of plasma agglutinins and provoked production of unique specificities not found in unexposed snails. However, the overall pattern of agglutination responses for snails with successfully developed parasites did not differ from those in which parasite development was unsuccessful. Agglutinating activity was inhibitable by several different monosaccharides, although plasma from infected snails was relatively unaffected by N-acetyl-glucosamine or N-acetyl-galactosamine. Wounding of snails provoked no change in plasma agglutination activity. As the highest agglutination titres were produced in snails with successfully developing parasites and agglutinin composition did not differ between snails with successful or unsuccessful parasites, the functional relevance of the response remains enigmatic. The production of unique agglutinins following exposure deserves additional study.

Agglutination↗
PubMed1997

Structure of a truncated human surfactant protein D is less effective in agglutinating bacteria than the native structure and fails to inhibit haemagglutination by influenza A virus.

Surfactant protein D (SP-D) is a lung-specific protein that is synthesized and secreted by lung epithelial cells and is believed to play an important role in lung host defence. This protein belongs to the C-type lectin family, which is characterized by an N-terminal cysteine-rich domain, a collagen-like domain, a neck domain and a carbohydrate recognition domain (CRD). To elucidate the biological actions of this animal lectin against such pathogens as micro-organisms, the biological activities of a recombinant partial SP-D lacking a collagen-like domain were examined. A recombinant human SP-D, consisting of a short collagen region (two repeats of Gly-Xaa-Yaa amino acid sequences), the neck domain and the CRD, was expressed in Escherichia coli. The recombinant SP-D was purified on a nickel column and then on a maltose-agarose column. This protein can form a trimeric structure owing to the neck domain and exhibits sugar-binding activity and specificity similar to those of native human SP-D. The recombinant SP-D caused dose-dependent and calcium-dependent agglutination of E. coli Y1088. The agglutination titre (the concentration required to achieve a 50% decrease in light transmission by agglutination) of recombinant SP-D was approx. 6-fold that of native SP-D. As for conglutination, the recombinant trimeric conglutinin required 8-16-fold higher concentrations than the native counterpart. In haemagglutination inhibition (HI) of influenza A virus, although native and recombinant conglutinin showed similar levels of HI activity, the recombinant SP-D was unable to inhibit haemagglutination, even at a concentration approx. 120-fold that of the native SP-D. The lectin precipitation and lectin blot assays showed that the truncated SP-D could bind to influenza A virus as well as native SP-D did. These results indicate that the agglutination activity of trimeric collectins can be largely retained, and furthermore that the oligomeric structure with several hands at opposite sites can enhance agglutination activity. The difference in HI activity against influenza A virus between native and recombinant SP-D suggests that SP-D uses a different mechanism from that of conglutinin to inhibit viral haemagglutination.

Agglutination↗
PubMed2000

Differentiation of Candida strains by lectin-mediated agglutination kinetics.

The lectin-mediated agglutination kinetics of Candida albicans, Candida tropicalis, Candida glabrata, Candida krusei, Candida kefyr, and Candida parapsilosis strains isolated from immunocompromised patients was investigated. The rate of the lectin-induced cell agglutination depends on the physiological state of the yeast cell population. Therefore, the Candida strains have to be cultivated and investigated under identical conditions. Lentil lectin (prepared from Lens culinaris), castor lectin, and concanavalin A were used. Different yeast species showed different agglutination behaviour. Furthermore, the lectin-mediated rate of agglutination is a strain-specific property which makes it possible to distinguish between different yeast strains of the same species. It is concluded that the lectin-mediated agglutination kinetics allows reproducible differentiation of yeast strains of the same species.

Agglutination↗
PubMed1993

The agglutination of beta-haemolytic streptococci by lectins.

The ability of 25 lectins, isolated from different plants and fungi, to agglutinate 95 clinical isolates of beta-haemolytic streptococci was examined. Cell suspensions were untreated, trypsin-treated or boiled at pH 2.0. None of the 95 untreated cell suspensions gave a visible reaction with any of the lectins. When the cells were trypsinised, 42 strains were agglutinated with one or more lectin and after boiling at pH 2, all the strains were agglutinated. After treatment with trypsin, 20 different agglutination patterns were observed, and after boiling, 19 patterns, four of which were similar. A correlation was found between Lancefield group C and some of these patterns. Some lectins reacted specifically with group C streptococci; DBA and WFA, both specific for D-GalNAc, DSA, a GlcNAc-specific lectin, and RPA, which showed a complex specificity, reacted only with group C strains. Furthermore, the lectin of Maackia amurensis reacted with 50% of group B streptococci only. Agglutination assays with lectins were reproducible, easy to perform, relatively inexpensive and, therefore, applicable to studies of cell-wall structure and epidemiology of beta-haemolytic streptococci.

Agglutination↗
PubMed1975

Changing agglutination activities of salivary immunoglobulin A preparations against oral streptococci.

Immunoglobulin A (IgA) was prepared from samples of parotid saliva collected from two individuals over a 150-day period. Standardized solutions of the IgA were tested for agglutinating antibody activity against strains of streptococcus salivarius, S. sanguis, S. mitis, and S. mutans that had been isolated from a homologous individual on day 30 and preserved in the lyophilized state. The agglutinating activity of the standardized IgA preparations against these strains was found to change over time, whereas the agglutination patterns of IgA prepared from saliva samples collected 3 days apart were generally similar. Differences in agglutination titers were also observed between IgA samples prepared from saliva collected on day 0 and day 150. The data indicate that the oral cavity may harbor streptococci of different antigenic composition representing the same species at a given time and that parotid IgA agglutinating antibody against these serotypes changes over time.

Adult↗
PubMed1994

Interactions with lectins and agglutination profiles of clinical, food, and environmental isolates of Listeria.

On the basis of preliminary trials with 14 collection strains of Listeria, five lectins (Canavalia ensiformis, concanavalin A; Griffonia simplicifolia lectin I; Helix pomatia agglutinin; Ricinus communis agglutinin; and Triticum vulgaris wheat germ agglutinin) were selected to set up a microtiter agglutination assay. The lectin agglutination profiles of 174 clinical, food, and environmental strains of Listeria monocytogenes, Listeria innocua, and Listeria seeligeri were investigated. Data on the standard determination of the antigenic structure were available for clinical strains; nonclinical isolates were assigned to serogroup 1 or 4 with commercial antisera. The listeria-lectin interaction was related to serological type rather than species; in particular, the strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, 3a, 3b, and 7 were never agglutinated by G. simplicifolia lectin I. The five-lectin set proved to be capable of detecting differences between serologically identical isolates of L. monocytogenes. Of the 150 isolates of this species, 144 were distributed over 15 different lectin agglutination profiles and 6 autoagglutinated, the overall typeability being 96%. However, the profiles encountered among L. monocytogenes isolates were not randomly distributed. With strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, and 3b, the clinical isolates fell into only two of the eight patterns recorded overall; with strains of serogroup 4 and serovar 4b, food and environmental isolates were distributed over eight of the nine patterns found in total, while clinical isolates were distributed over five patterns. In a comparative study of 15 epidemiologically relevant isolates of L. monocytogenes from five distinct outbreaks, strains with identical phage types and/or DNA fingerprints displayed identical lectin profiles. The heterogeneity of agglutination profiles may form the basis of a new approach to L. monocytogenes typing.

Agglutination↗
PubMed2000

Use of hydrolyzed whey peptide to inhibit culture agglutination.

Papain was used to hydrolyze sweet whey to prepare peptides that were harvested with ultrafiltration membranes (molecular weight cutoffs of 10,000, 3000, and 1000). Insure buffer salts were added to whey peptides (ratio 40:60% solids, respectively) to prepare media that were tested for their ability to inhibit culture agglutination. Commercial Insure medium (75.7 g/l) was used as a control. Skim milk (240 ml) in 250-ml graduated cylinders was inoculated (4%) with Lactococcus lactis spp. lactis B62 or E72. Culture agglutination was determined by measuring upper center and bottom pH values of the skim milk column during 5 h of incubation. A pH differential was calculated by subtracting the bottom pH from the upper center pH. Cultures grown in media containing whey peptides agglutinated in skim milk to a lesser degree than when grown in the control medium. Culture agglutination was inhibited to a greater degree when cultures were grown in the 1000 molecular weight cutoff peptide medium than when grown in the 10,000 or 3000 molecular weight cutoff peptide medium. When culture E72 was grown in medium containing 1000 molecular weight cutoff peptides, culture agglutination was completely inhibited.

Agglutination↗
PubMed1975

Lectin agglutinability of non-neoplastic and neoplastic human lymphoid cells in vitro.

Agglutination by two lectins, Concanavalin A (Con A) and Ricinus communis agglutinin (RCA), has been investigated in a human lymphoid cell system. The main conclusions of this study are: (1) no systematic correlation exists between the neoplastic state and sensitivity to Con A or RCA; (2) cells of neoplastic lines vary unsystematically in their surface properties as evaluated by Con A agglutination, with the possible exception that presence of Epstein-Barr virus (EBV) is associated with a high degree of agglutination and (3) cells of diploid lymphoblastoid lines and phytohemagglutinin (PHA)-stimulated lymphoctes agglutinate similarly and significantly better than unstimulated T- or B-lymphocytes. The relatively simple Con A agglutination assay can be used as an adjunct in classification of human lymphoid cell lines.

Agglutination↗
PubMed1978

Trypsinization increases lectin-induced agglutinability of uncapacitated guinea pig sperm.

Capacitated guinea pig sperm are more agglutinable by the lectin soybean agglutinin (SBA) than uncapacitated sperm (Talbot and Franklin, '78). This study demonstrates that uncapacitated guinea pig sperm become as agglutinable by SBA as capacitated sperm when treated with trypsin, but not chymotrypsin. The pattern of lectin induced sperm agglutination after trypsinization resembles that for capacitated sperm. Also, trypsinization specifically increases SBA induced agglutination and does not affect agglutination by RCA-60; similar results are obtained during in vitro capacitation. Taken together, these data may indicate that a trypsin-like enzyme modifies the sperm surface during capacitation.

Agglutination↗
PubMedDate not supplied

Differential lytic and agglutinating activity of the anti-Lewis(x) monoclonal antibody FC-2.15 on human polymorphonuclear neutrophils and MCF-7 breast tumor cells. In vitro and ex vivo studies.

The Lewis(x) (Le(x)) trisaccharide (CD15) linked to proteins and glycolipids is highly expressed on the surface of normal human polymorphonuclear neutrophils (PMN) and several human neoplasias, such as breast and gastrointestinal carcinomas and chronic myeloid leukemias. FC-2.15 is an IgM murine mAb that specifically recognizes Le(x) and has been previously shown to mediate the in vitro lysis of Le(x)(+) cells by human complement. In a phase I clinical trial of FC-2.15, a temporary neutropenia was the main toxicity, and antitumor responses were observed. In order to characterize FC-2.15 further and determine the physiological relevance of Le(x) binding, the reactivity of FC-2.15 on PMN was investigated under several conditions. Flow cytometry revealed a strong reactivity of FC-2.15 with almost 100% of PMN, and Scatchard analysis demonstrated an affinity constant of 5.14 x 10(9) M(-1) and 1.11 x 10(6) antigen sites/cell. In vitro, the binding of Le(x) epitopes by FC-2.15 induced PMN homotypic aggregation, only 28.4 +/- 4.1% remaining as single cells. When PMN and the Le(x)(+) MCF-7 breast cancer cells were co-incubated, FC-2.15 induced heterotypic aggregation. In 51Cr-release assays employing human complement, FC-2.15 lysed 93.4 +/- 7.9% of PMN and 87.8 +/- 10.7% of MCF-7 cells. However, when the effect of FC-2.15 was tested in ex vivo circulating blood, no lytic activity against PMN was detected, whereas MCF-7 cells were still lysed. Blood smears demonstrated that FC-2.15 induced PMN agglutination and heterotypic aggregates when MCF-7 cells were present. A pretreatment of PMN with colchicine impaired PMN agglutination both in vitro (single PMN = 81.15 +/- 4.35%) and in ex vivo circulating blood. In the latter condition, FC-2.15-lytic activity was restored, suggesting that PMN homotypic aggregation by FC-2.15, but not lysis, is dependent on microtubule integrity and that PMN agglutination hinders their lysis. Moreover, when 51Cr-release assays were performed following agglutination, FC-2.15 cytotoxicity was restricted to isolated PMN. It is suggested that crosslinking of Le(x) epitopes by FC-2.15 induces PMN to form homotypic aggregates. It is suggested that the neutropenia observed in FC-2.15-treated patients would be due to PMN agglutination and margination, rather than lysis. In addition, FC-2.15 appears to be able to lyse Le(x)(+) tumor cells in circulation.

Agglutination↗
PubMed1975

Sperm-agglutinating antibodies and testicular morphology in fifty-nine men with azoospermia or cryptozoospermia.

The relationship between the state of the germinal epithelium and the type and titer of circulating sperm-agglutinating antibodies has been investigated in a series of 59 azoospermic or occasionally cryptozoospermic men. The patients were grouped according to the condition of the germinal epithelium as observed from testicular biopsy specimens, as well as to type and titer of circulating sperm-agglutinating antibodies investigated by a previously described microagglutination technique. Evidence is presented to suggest that the presence of mature spermatozoa in the testicular structures may be a prerequisite for the spontaneous production of circulating sperm-agglutinating antibodies, at least of the head-to-tail (H-T) agglutinating type. Furthermore, these circulating H-T sperm-agglutinating antibodies, once they are formed, do not seem to interfere adversely with the germinal epithelium of the carrier.

Agglutination↗
PubMed1981

A rapid quantitative staphylococcal co-agglutination assay. Utilization for the assay of bovine factor VIII-related antigen.

A simple and rapid technique to measure bovine factor VIII-related antigen has been developed which utilizes protein A-bearing staphylococci and monospecific rabbit antiserum to bovine factor VIII. Staphylococci coated with a specific antibody agglutinate when they are mixed with the specific antigen. We have used an aggregometer to detect an quantitate the agglutination of the antibody-coated staphylococci. The assay has been optimized with respect to amount of antiserum needed for coating staphylococci, concentration of antibody-coated staphylococci, pH and ionic strength of the assay system, and stirring speed of the aggregometer. The staphylococcal co-agglutination assay as monitored by an aggregometer is at least 10 times more sensitive than the conventional slide agglutination method, and can detect as little as 0.1 microgram/ml of factor VIII antigen. It however, cannot be used to quantitate factor VIII-related antigen in plasma, since plasma contains some components which can non-specifically agglutinate staphylococci.

Agglutination Tests↗
PubMed1986

Cell agglutination by a novel cell surface sialoglycopeptide inhibitor and the relationship between its protease and biological activities.

A bovine sialoglycopeptide, purified to homogeneity and capable of inhibiting cellular protein synthesis and proliferation, was shown to agglutinate a wide variety of nontransformed and transformed cells. The cell agglutination activity was shown to be independent of the biological inhibitory action and most likely related to a protease activity that could not be physically separated during purification of the sialoglycopeptide. Samples that were completely biologically inactivated retained full protease activity and their ability to agglutinate target cells. Balb/c 3T3 cells were not agglutinated by the sialoglycopeptide and they elicited a protein that interfered with the agglutination reaction and even redispursed cells that already had been aggregated by the inhibitor.

Agglutination↗
PubMedDate not supplied

Evaluation of the direct agglutination test as an immunodiagnostic tool for kala-azar in India.

The direct agglutination test (DAT) has been assessed as a diagnostic procedure for visceral leishmaniasis. Fifty-six of 58 sera (96.5%) from confirmed cases of visceral leishmaniasis, whose bone marrow aspirates contained Leishmania donovani amastigotes, had agglutinating antibodies above the cut-off titre of 1:800. None of the sera from healthy control subjects from non-endemic or endemic areas had anti-leishmanial antibodies. Similarly, none of the sera obtained from cases of malaria or tuberculosis had agglutinating antibodies above the cut-off titre. A significant decline in agglutinating antibody titre in 3 cases following antileishmanial chemotherapy appeared to correlate with regression of clinical symptoms and the absence of amastigotes from bone marrow aspirates. One of 3 cases developed post-kala-azar dermal lesions and sera from this subject had an elevated agglutinating antibody titre. It is concluded that the DAT is a sensitive and specific test to confirm visceral leishmaniasis. As the formalin-fixed promastigotes, stained with Coomassie blue, which are used as antigen could be stored at 4 degrees C for 6 months without any loss of ability to detect anti-leishmanial antibodies, the DAT is recommended for use under field conditions.

Agglutination Tests↗
PubMed1976

Lack of correlation between agglutinability, the surface distribution of con A and post-confluence inhibition of cell division in ten cell lines.

Agglutinability by concanavalin A, distribution of surface-bound concanavalin A, and maximal cell density in monolayer culture were examined under similar conditions in parallel cultures of ten established cell lines. The degree of agglutinability of the cell lines did not correlate with the presence or absence of patching of concanavalin A bound to the cell surface, as determined with a hemocyanin marker. Agglutinability was also not always correlated with the loss of post-confluence inhibition of cell division. Two clones of mouse 3T3 fibroblasts that maintained post-confluence inhibition of cell division and low agglutinability differed substantially with respect to the surface distribution of concanavalin A. Patching of concanavalin A binding sites is neither necessary nor sufficient to explain differences in agglutinability between cell lines.

Agglutination↗
PubMedDate not supplied

Agglutination of isolated rat bladder cells by lectins after administration of N-butyl-N-(4-hydroxybutyl) nitrosamine.

Lectins, concanavalin A (Con A), wheat germ agglutinin (WGA), and Ricinus communis agglutinin (RCA) were used for agglutination of isolated rat bladder cells after administration of N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). The results showed that WGA and RCA, as well as Con A, agglutinated rat bladder cells during the early stage of bladder carcinogenesis. The agglutinations by the 3 kinds of lectins were different; WGA and Con a agglutinated only BBN-treated cells but RCA agglutinated both BBN-membrane alterations during the early phase of bladder carcinogenesis.

Agglutination↗
PubMed1982

Application of the mixed cell agglutination test for cell surface antigens to renal cell carcinoma.

The mixed cell agglutination test is used to demonstrate the presence or absence of the A, B and H(O) blood group antigens on the surface of superficial bladder tumors. Absence of these antigens has been shown to correlate well with invasive disease. Therefore, the test has an important prognostic value in bladder cancer. To determine its clinical value in patients with renal cell carcinoma the mixed cell agglutination test was done on unstained sections of tumor from 42 patients for whom followup was available. Red cell adherence was determined independently by each of us and without knowledge of the clinical status of the patients. Only 3 tumors were graded negative, while 14 were each 2 and 3 plus, and 11 were 4 plus. Tumor stage and patient blood type did not correlate with the degree of agglutination. Over-all survival did correlate significantly with 4 plus agglutination (p less than 0.041) as did 1 and 5-year survival (p less than 0.049 and 0.046, respectively). All 11 patients whose tumors had 4 plus reactions are alive, with a median followup of 5.0 years. Currently, there is little to offer the patient who has metastatic disease or is at high risk for its development after nephrectomy. Our preliminary report suggests some degree of accuracy in predicting the latter group by excluding those at low risk. Further studies would seem warranted so that the mixed cell agglutination test might be applied when better adjuvant therapy is discovered.

ABO Blood-Group System↗