Changes in the "shape reaction" and "orientation reaction" of cell nuclei as a consequence of neoplastic transformation

Reactions of cell nuclei on curvature of cylindrical surfaces (curvature radii 333, 75 or 61 mcm) in 9 lines of cultured transformed human, Syrian hamster, rat and murine fibroblasts were studied quantitatively. The nuclear elongation was assessed as a ratio of long to short axes. Contact orientation was characterized by values derived from the angles, formed by long nuclear axes with the direction of cylinder axis. Due to transformation, cells lost the ability to elongate their nuclei in response to cultivation on cylindrical surfaces. The ability of cells cultured on cylindrical surfaces to increase the contact orientation values was also lost or weakened considerably.     

Plasmids of antibiotic-resistant clinical strains of E. coli]

Analysis of 53 antibiotic resistant clinical strains of E. coli isolated from patients with various purulent inflammatory diseases is presented. According to the data of the electrophoretic study 83 per cent of them carried 2 to 6 plasmids. Thirteen of them carried the conjugation R-factor. The antibiotic resistance in the other strains was due to the non-conjugation plasmids.     

Autoaggressive immunocompetent cells in the bodies of mice at remote periods following irradiation]

Lethally irradiated DBA/l mice or (C57Bl X DBA/l1 F1 hybrid mice were injected with therapeutically effective doses of isologous bone marrow cells; simultaneously syngeneic lymph node cells from either intact (control) animals or mice survived after sublethal irradiation were transplanted. In control the viability of the recipients was not affected by the presence of lymphoid cells in the mixed transplant. In contrast, the beneficial action of the bone marrow cells was abolished (killing-effect) by the lymphoid cells from mice sacrificed 6 to 12 months after the irradiation (600--700 r). The manifestation of the killing-effect depended on the number of the transplanted lymphoid cells and on the dose of the bone marrow cells in the transplant. The killing-effect was not revealed when the lymphoid cells were obtained from the donors on the 30th day after irradiation. The results suggest the autosensitization of the organism at the late postirradiation periods.     

Determination of human leukocyte interferon by a microfluorimetric immunologic method]

The possibility of quantitative determination of human leucocyte interferon using FITC-labeled antiinterferon antibodies was studied. A highly specific antiinterferon immunoglobulin was obtained as a result of longterm immunization of a donkey with human leucocyte interferon followed by fractionation and immuno-absorbtion of immune plasma. This immunoglobulin was labeled with FITC and used for human leucocyte interferon assay in direct and indirect reactions of fluorescence immunoinhibition. The titres of different human leucocyte interferon preparations in this immunoassay were comparable with the titres of the same preparations detected by interferon inhibition of viral cytopathic effect.     

Physico-chemical and biological characteristics of Pseudomonas aeruginosa elastase

Elastase isolated from P. aeruginosa clinical strain hydrolyzes elastin, casein, hemoglobin, ovalbumin, gelatin, fibrin, collagen. The optimum pH ensuring the activity of the enzyme is 7.8-8.0. Elastase shows maximum stability at pH 6.6-9.0. Heating at 80 degrees C for 10 minutes results in its practically complete inactivation. Elastase is a highly radiosensitive enzyme. Chelating agents and zinc, cobalt, mercury ions suppress its activity. Sodium and ammonium chlorides selectively inhibit the elastolytic, but not proteolytic activity of the enzyme. Elastase shows pronounced dermonecrotic and keratolytic action.