Biomedical subjects

J Potomski

Publications and source records attributed to J Potomski.

9 recordsLinked to original sources

PubMed1987

Purification of cytotoxic enterotoxin of Aeromonas sobria by use of monoclonal antibodies.

Cytotoxic enterotoxin of Aeromonas sobria was purified by affinity chromatography with monoclonal antibodies. The purified enterotoxin gave a single protein band in polyacrylamide gradient gel electrophoresis and its mol. wt estimated by this technique was 63,000; it had a pI of 6.2. The purified enterotoxin caused fluid accumulation in rat ileal loops and in infant mice, was cytotoxic to cultured cells, was haemolytic to human erythrocytes, and was lethal to mice after intravenous injection. The relative concentrations of enterotoxic, cytotoxic and haemolytic activities were approximately the same in a culture filtrate and in purified, electrophoretically homogeneous enterotoxin. The three activities were also inactivated to the same extent after incubation for 10 min at 56 degrees C. There was no immunological cross-reactivity with cholera toxin (CT) nor did antiserum to CT neutralise the biological effects of the toxin.

Aeromonas↗

PubMed1987

Aeromonas cytotonic enterotoxin cross reactive with cholera toxin.

Isolation by affinity chromatography from crude culture filtrate of Aeromonas sobria of protein that cross reacted with cholera toxin (CT) revealed a toxin that produced fluid accumulation in rat ileal loops and in infant mice and caused rounding of Y1 adrenal cells. All these activities were neutralised by antiserum to CT. There was no haemolytic or cytotoxic activity associated with this CT-cross reactive cytotonic enterotoxin. CT-cross reactive material detected in enzyme linked immunosorbent assay (ELISA) was produced by 25% of Aeromonas isolates from faeces of children with or without diarrhoea-26% of A. sobria, 20.0% of A. hydrophila and 24% of A. caviae tested gave positive ELISA results. Most strains that produced this cytotonic enterotoxin but no cytotoxic enterotoxin were isolated from children without diarrhoea. Toxin preparations from Aeromonas spp. that completely inhibited adenosine-5'-diphosphate-induced platelet aggregation, an effect related to elevation of intracellular cAMP, were, with one exception, cross reactive with CT in ELISA.

Aeromonas↗

PubMed1983

Localization of carcinoembryonic antigen in mesenteric lymph nodes of patients with gastrointestinal cancer.

Mesenteric lymph nodes obtained at surgery from 36 patients with gastrointestinal tract cancer were studied by immunofluorescence for the presence of carcinoembryonic antigen (CEA). Granular deposits of CEA in a homogenous mixture with immunoglobulins and complement were detected in the activated germinal centers in 12 lymph nodes from 8 investigated cases. Identification of CEA in germinal centers was confirmed by blocking and absorbtion procedures. Successful elution of immunoglobulins and part of CEA content with a buffer known to dissociate antigen-antibody bonds suggested that these deposits represent CEA immune complexes.

Adenocarcinoma↗

PubMed1982

High and low Fc IgG-receptor expression in human chronic granulocytic leukaemia cells.

Discontinuous density-gradient centrifugation was used to separate chronic granulocytic leukaemia (CGL) cells in the chronic phase and blast crisis (BC) into fractions containing granulocytes in individual stages of maturation. The occurrence of the Fc IgG (FcR) and complement-component receptors (CR1 and CR2) in each fraction was estimated. It was established that, with increasing yields of mature granulocytes, the proportion of cells bearing Fc and C3 receptors increased. The most important finding was that the high- and low-receptor categories of CGL cells in chronic phase depended on the percentage of FcR+ cells. In the high-receptor CGL group, in addition to FcR, the proportion of CR1+ and CR2+ cells was also greater than in the low-receptor CGL group. Some differences in clinical course of both immunological CGL groups were observed.

Adult↗

PubMed1980

Fc and C3 receptors as membrane differentiation markers of acute myelogenous leukaemia cells.

Acute myelogenous leukaemia cells (AML) and cells of chronic myelogenous leukaemia blast crisis (CGL-CB) were examined for the presence of receptors for Fc IgG fragment (FcR), receptors for the complement components (CR1 and CR2), and the surface immunoglobulins including the light kappa and lambda type chains. The leukaemia blasts were found to be the cells poor in receptors and poorly differentiated. As a rule, they contained very small amount of detectable FcR, CR2, and CR1. Analysis of AML cell populations separated on the discontinuous density gradient revealed that the appearance of FcR was followed by CR2 and CR1. The CGL-CB cells were more differentiated immunologically since, in comparison with the AML cells, in greater percentage they expressed the FcR, and the receptors for complement. Assays for surface immunoglobulins indicated that they were not an active product of the leukaemic blasts, but rather exogenous in origin.

Complement C3↗

PubMed1980

Relationship between different cell surface markers in chronic lymphocytic leukemia.

Peripheral blood lymphocytes from 15 patients with chronic lymphocytic leukemia (CLL) and 13 normal controls were examined for the presence of surface markers: CLL antigen, surface immunoglobulins, receptors for sheep erythrocytes, receptors for the IgG Fc, C3b, C3d and receptor(s) for mouse erythrocytes. Leukemic lymphocytes were characterized by the presence of CLL antigen and a significant increase in the capacity to bind mouse erythrocytes. CLL antigen was correlated with surface immunoglobulins and receptor of IgG Fc, however, the receptor for mouse red cells was not correlated with other surface markers. Neuraminidase treatment of CLL lymphocytes significantly increased proportion of mouse erythrocyte rosettes. The routine use of mouse erythrocyte rosettes in the immunodiagnostics of B lymphoproliferative disorders is postulated.

Animals↗

PubMed1979

Effect of freezing conditions in liquid nitrogen on biological properties of Treponema pallidum.

The influence of various conditions of freezing in liquid nitrogen on the motility, virulence, antigens, and immunogenicity of Treponema pallidum was studied. The suspending medium, rate of freezing, kind and concentration of cryprotector, and duration of preincubation with cryoprotector were found to be critical. On the basis of the results obtained the optimal conditions of freezing of T. pallidum in liquid nitrogen were established. These are: the Nelson-Diesendruck medium with the addition of 10% DMSO; freezing rate 1 degree per min, and thawing rate between 12.6 degrees and 120 degrees per min.

Antibodies, Bacterial↗

PubMed1979

Correlation between immunohistochemical localization of carcinoembryonic antigen (CEA) and histological estimation of carcinomas, normal mucosae and lymph nodes of the digestive tract in humans.

The localization of the carcinoembryonic antigen (CEA) in carcinomas and mucosae of the digestive tract in humans and in mesenteric lymph nodes was studied by indirect immunofluorescence. In colonic and gastric adenocarcinomas, CEA had typical centroglandular localization. Cytoplasmic localization of the CEA was seen in invasive cancer cells having lost their glandular organization. CEA was also present in colonic and gastric mucosae surrounding the tumor. In gastric mucosa obtained at autopsy from subjects with nonneoplastic diseases, CEA was found only in glands having undergone intestinal metaplasia. In lymph nodes of cancer patients CEA was always present in metastatic cells and in germinal centers. Characteristic localization of CEA in germinal centers of metastatic and nonmetastatic lymph nodes could suggest the presence of CEA-anti-CEA immune complexes.

Adenocarcinoma↗

PubMed1979

Carcinoembryonic (CEA)--like antigen in adenomas and cancers of the breast in human patients.

By using specific anti-CEA serum and indirect immunofluorescence, a substance was detected in breast cancers which reacted similarly to CEA demonstrable by the same method in cancers of gastrointestinal tract. However, the double diffusion test in agar gel and additional absorption analysis showed that it was a glycoprotein different from CEA, although possessing common or similar antigenic determinants with it. This antigen also differs from another antigen called "nonspecific cross-reacting antigen NCA" and from alpha 1-acid glycoprotein of human serum.

Adenocarcinoma↗