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Biomedical subjects

R Wierzbicki

Publications and source records attributed to R Wierzbicki.

53 records · Page 3Linked to original sources
PubMed1980

Immunospecificity of nuclear antigens in chicken erythroid cells.

Specific antisera were produced against chicken reticulocyte dehistonized chromatin. The antisera reacts strongly with chicken reticulocyte chromatin, but only marginally with chicken erythrocyte chromatin. There is no reticulocyte antigen detected in chicken liver. Reticulocyte maturation is accompanied by a gradual decrease in the chromatin immunological activity and template capacity. The reduction of immunological activity is due to the change of chromatin conformation during erythrocyte maturation. Dehistonization and sonication of erythrocyte chromatin raises the erythrocyte chromatin immunological activity to levels similar to those of reticulocyte chromatin. The erythrocyte nuclear antigens are class specific, not being found in frog erythroid cell or murine Friend leukemia cell chromatins.

Animals↗
PubMed1980

Chicken reticulocyte nuclear antigen: its identification and relation to transcriptive activity in erythropoietic cells.

Antibodies to chicken reticulocyte dehistonized chromatin were produced. These antibodies can distinguish between chromatin from reticulocytes and erythrocytes and have no activity with chicken liver chromatin. The antibodies will also differentiate between reticulocytes and erythrocytes by the the horseradish peroxidase bridge localization technique. The nonhistone protein components of the antigenic complex are very tightly bound to the DNA, removable by extraction with sodium dodecyl sulfate but not 2.5 M NaCl-5 M urea. Our data indicate that the antigen complexes could actually be present in both reticulocytes and erythrocytes but that chromatin condensation causes a structural masking of the complexes which coincides with the known decline in transcriptive activity of the erythrocyte.

Animals↗
PubMed1976

Studies on histones and nuclear phosphoproteins of rat liver and Morris hepatoma.

1. The chemical composition of chromatins obtained from Buffalo rat liver and Morris hepatoma strain 5123 was investigated. 2. The presence of an additional subfraction within the very lysine-rich histone (fl) was states in both kinds of tissues. It amounted to about 8% and 5% of fl in rat liver and Morris hepatoma, respectively. 3. Nuclear phosphoproteins (phenol-soluble) from normal and tumour tissues in polyacrylamide gel in SDS showed some qualitative differences in the range of molecular weights of about 40 000 - 70 000 and over 100 000 daltons.

Animals↗
PubMed1976

Non-histone chromatin proteins during maturation of avian erythroid cells.

1. In chicken erythroid cells (erythroblast, reticulocyte and erythrocyte) maturation was accompanied by a decrease in the content of non-histone chromatin proteins. 2. Phenol-soluble non-histone chromatin proteins (phosphoproteins) from the three cell populations studied, showed differences in the behavior on sodium dodecyl sulphate polyacrylamide-gel electrophoresis, and isoelectric focusing. Phosphoprotein of immature cells had a higher content of fractions of about 86 000 and 23 000 daltons than the phosphoproteins of erythrocytes.

Anemia, Hemolytic↗
PubMedDate not supplied

Effect of methylmercuric chloride (MMC) on fibrin polymerization.

Methylmercuric chloride (MMC) in concentrations 0.1-10 microM reduces the amount of fibrinopeptides released from thrombin-activated human fibrinogen. However, the fibrin clot formation is not discriminated and the turbidity of the fibrin gel is even augmented. MMC does not cause such changes in the process of repolymerization of fibrin monomers. The addition of fibrinopeptides to the fibrin monomers results in a similar increase of turbidity of the repolymerizing sample in the presence of MMC as in the case of fibrinogen clotting. These experiments indicate that MMC modifies the structure of fibrin in the presence of fibrinopeptides.

Blood Platelets↗
PubMedDate not supplied

Blood coagulation changes in rats poisoned with methylmercuric chloride (MeHg).

The effects of methylmercuric chloride on the coagulability of blood were studied in rats. The administration of a single dose (17.9 mg Hg/kg) and a repeated dose (5 X 8 mg Hg/kg/day) of this compound resulted in hypercoagulation. The reduction of the clotting time, the increase of fibrinogen level in plasma and changes characteristic of hypercoagulation in the thromboelastographic parameters were observed. Simultaneously, signs of impaired activity of blood platelets: decreased aggregation velocity and clot retraction as well as prolongation of the bleeding time were noticed.

Adenosine Diphosphate↗
PubMedDate not supplied

Coagulation and fibrinolysis in rats poisoned with mercuric chloride.

The effect of mercuric chloride on blood coagulation and fibrinolysis in rats was studied. The mercurial was administered to the animals intragastrically in a single dose of 17.9 mg Hg/kg and the effects were tested on the 1st, 3rd and 7th day. The symptoms of hypercoagulability accompanied by decreased fibrinolytic activity of the plasma were observed in the poisoned rats. The main reason of the lowered fibrinolytic activity seemed to be the inhibition of plasma plasminogen activator or the inhibition of plasminogen activation reaction catalyzed by this enzyme.

Animals↗
PubMedDate not supplied

Plasma and platelet fibrin-stabilizing factor activity in rats intoxicated with phenylmercuric acetate.

Effect of phenylmercuric acetate on the activity of rat plasma and platelet fibrin-stabilizing factor (FSF) was studied. The mercurial was administered to the animals intragastrically in a single dose of 17.9 mg Hg/kg or in repeated doses of 1.79 mg Hg/kg, twice a week for 152 days. The activities of the investigated fibrin-stabilizing factors were significantly increased in the case of intoxicated rats. Such an effect was observed in both types of the exposure.

Animals↗