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Biomedical subjects

K Zakrzewski

Publications and source records attributed to K Zakrzewski.

At least 37 records · Page 2Linked to original sources
PubMed1995

Induction of macrophage procoagulant activity by murine hepatitis virus strain 3: role of tyrosine phosphorylation.

The induction of a unique macrophage procoagulant molecule by murine hepatitis virus strain 3 correlates with the severity of viral hepatitis. The role of tyrosine phosphorylation in the signalling pathway leading to procoagulant expression was studied. Murine hepatitis virus strain 3 initiated a rapid increase in phosphotyrosine accumulation. Tyrosine kinase inhibition precluded this increase and abrogated expression of the virus-induced procoagulant mouse fibrinogen-like protein (musfiblp) gene. These findings suggest that manipulation of this signalling pathway in vivo might represent a novel approach to treating this disease.

Animals↗
PubMed1994

Ultrastructure of the primitive neuroectodermal tumors (PNET).

We report a prospective series of consecutive cases of primitive neuroectodermal tumor (PNET) studied by electron microscopy. Virtually all specimens showed a differentiation along neuroblastic lines as evidenced by the presence of neurites, dense-cored vesicles, microtubules and adhesive plaque junctions. We observed also numerous intracytoplasmic cilia and autophagic vacuoles. Synaptic specializations were only rarely seen. We conclude that PNET is a tumor category which is not undifferentiated ("primitive") and clearly exhibits features of neuroblastic differentiation.

Adolescent↗
PubMed1992

[A case of heterotopic ossification in the parapharyngeal region connected with the C2 vertebra in a 9-year-old girl].

A rare case of extraskeletal ossification in the parapharyngeal region related to C2 cervical vertebra was observed in a child, without any history of trauma, inflammation or endocrinological disease. One-step surgical intervention was carried out from the side of the neck and pharynx making possible complete removal of the lesion. The girl was admitted to the hospital with dysphagia and breathing difficulties increasing in the last 6 months. During that time the child was observed in laryngological hospital departments. After the operation Horner syndrome and hypoglossal paresis developed, but presently the child is without symptoms.

Axis, Cervical Vertebra↗
PubMed1992

[Transfontanellar USG examination using a color Doppler method in the diagnosis and differentiation of vascular changes in the CNS (preliminary report)].

In the light of own experiences the diagnostic possibilities are presented of using Doppler ultrasonography with transfontanellar projection in the diagnosis and differentiation of vascular changes. Colour Doppler USG makes possible recording and measurement of blood flow in the vessels and may be specially useful in cases of central nervous lesions. The paper is supplemented with a videographic record of Galen's vein aneurysm imaged by Doppler USG.

Brain Neoplasms↗
PubMed1976

A versatile method for purification of diphtheria toxoid for immunization purposes.

Diphtheriae growth supernatant. The toxoid was quantitatively recovered from the immunosorbent in two fractions: the first in 0.005 M hydochloric acid and the second in 6' M urea containing 0.1 M HCL. Both fractions were soluble in aqueous solvents, and both had a similar specific activity: between 200 and 250 Lf/mg protein, and about 1.5 protective unit (ED50) per l Lf unit, as assayed in guinea pigs. Using the same procedure, the specific activity of a commerical toxoid preparation, purified and concentrated, was increrased two fold, from 130 Lf/mg to 260 Lf/mg protein.

Animals↗
PubMed1975

The activation by staphylokinase of human plasminogen.

The activation of human plasminogen by a highly purified staphylokinase was investigated using casein or an active site titrant (p-nitrophenyl-p-guanidinobenzoate, NPGB) as a substrate. The reaction rate was time dependent, showing a pronounced lag period with either substrate. Saturation curve estimated from the caseinolytic assay was sigmoid, but changed to quasi-hyperbolic in the presence of pre-formed human plasmin. With NPGB, the extent of plasminogen conversion into esterolytic plasmin was directly proportional to staphylokinase concentration, and the saturation point was reached when the molar concentration of staphylokinase equaled that of plasminogen. It is concluded that staphylokinase acts stoichiometrically, forms an equimolar complex with plasminogen, and thus is not an enzyme but a modifier. Staphylokinase-activated plasminogen exhibits properties of a hysteretic enzyme.

Endopeptidases↗