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Biomedical subjects

M Woźniak

Publications and source records attributed to M Woźniak.

At least 55 records · Page 3Linked to original sources
PubMed1980

Purification and regulatory properties of pig kidney AMP deaminase.

AMP deaminase (EC 3.5.4.6) from pig kidney was purified about 1200-fold by chromatography on cellulose phosphate. The enzyme showed a sigmoid-shaped substrate saturation curve which was converted to hyperbolic by addition of ATP. The ATP-activated enzyme was sensitive to phosphatidylcholine-containing liposomes which caused a further increase of activity by lowering the S0.5 value and increasing V max. In the absence of ATP, the enzyme was not sensitive to phosphatidylcholine-containing liposomes. Phosphatidate-containing liposomes exerted an inhibitory effect both in the presence and absence of ATP. In the presence of ATP phosphatidate was a non-competitive inhibitor. Orthophosphate was found to be a competitive inhibitor of AMP deaminase from pig kidney. When the phosphatidylcholine/phosphatidic acid ratio in liposomes was 2.7, AMP deaminase was activated, whereas when this ratio dropped below 2.1, liposomes exerted a non-competitive inhibitory effect.

AMP Deaminase↗
PubMed1979

[Post-traumatic cerebral artery thrombosis].

In the years 1965--1978 thrombosis of the intracranial vessels of different aetiology was diagnosed in 204 patients treated at the Department of Neurosurgery, Medical Academy in Warsaw. The authors selected from this group 8 cases described in greater detail in which there was an evident temporal relationship between trauma and the development of the disease. The severity of the sustained trauma was without a significant influence on the development of post-traumatic thrombosis. Clinical Manifestations increased in intensity usually within the first 48 hours and in only one case they appeared 2 weeks after trauma. In the clinical status of the patients of considerable interest was usually absence of disturbances of consciousness with presence of serious signs of focal central nervous system damage. Of decisive diagnostic significance was cerebral angiography which localized the site of thrombosis and excluded presence of post-traumatic intracerebral haematoma. In 7 cases thrombosis affected the main trunk or branches of the middle cerebral artery. The prognosis as to survival of such patients is generally good but in most cases disability of different degree developed following thrombosis.

Adult↗
PubMed1978

Modification by liposomes of the adenosine triphosphate-activating effect on adenylate deaminase from pig heart.

Adenylate deaminase (AMP deaminase, EC 3.5.4.6) of a high substrate specificity was purified from pig heart by chromatography on cellulose phosphate. The enzyme shows a co-operative binding of AMP [h (Hill coefficient) 2.35, with SO.5 (half-saturating substrate concentration) 5mM]. ATP and ADP act as positive effectors, lowering h to 1.55 and SO.5 to 1 mM. The addition of liposomes (phospholipid bilayers) to ATP-activated or ADP-activated enzyme causes a further shift of the h value to 1.04 and SO.5 to 0.5 mM. For ATP-activated enzyme the addition of liposomes increases Vmax. by about 100%, and for ADP-activated enzyme by 50%. Liposomes have no effect on the kinetics of AMP deaminase in the absence of ATP and ADP, and neither do they influence the inhibitory effect of orthophosphate on heart muscle AMP deaminase. Metabolic implications of these findings are discussed.

AMP Deaminase↗
PubMed1977

Activities of some peptidases and glycolytic enzymes in cells of the amniotic fluid. II. Pregnancies complicated by threatening intrauterine fetal asphyxia.

Activities of leucylaminopeptidase, aspartyl aminopeptidase, gamma-glutamyl transpeptidase, oxytocinase, phosphohexoisomerase, phosphofructokinase and aldolase were studied in amniotic cells from cases of pregnancy complicated by threatening intrauterine fetal asphyxia. Leucylaminopeptidase and oxytocinase activities were much higher in the group of pregnancies complicated by threatening fetal asphyxia than in the control group. It was concluded that elevated activity of the aforementioned enzymes in cells of the amniotic fluid from pregnancies complicated by threatening intrauterine asphyxia is due to acute hypoxia of the fetus.

Adult↗
PubMed1976

Evaluation of the influence of epoxide resins and their hardeners on the female body. II. Biochemical studies.

In women employed in an industrial plant in direct contact with epoxide resins and their hardeners, the following biochemical parameters were determined in blood: total protein, seromucoid, haptoglobin, hemoglobin variants, methemoglobin, alpha1-inhibitor of trypsin, lactate dehydrogenase, aspartate and alanine aminotransferases, alkaline and acid phosphatase, gamma-glutamyl transpeptidase, leucylaminopeptidase, and alanine aminopeptidase. Depending on duration of work, Hb A2 fraction and lactate dehydrogenase increased significantly, and aspartate aminotransferase, acid and alkaline phosphatase activities decreased. In pregnant women, leucylaminopeptidase activity and isozyme of placental alkaline phosphatase were decreased.

Acid Phosphatase↗
PubMed1976

Preparation and properties of tRNA from human placenta.

1. The tRNA preparation obtained from human placenta by phenol extraction and DEAE-cellulose chromatography was homogeneous on ultracentrifugation and showed high amino acid acceptor activity. 2. The analysis of the isoaccepting tRNA by reversed-phase chromatography (RPC-5 system) showed the presence of 5 fractions for glycine and leucine, 3 for tyrosine, alanine and valine, 2 for arginine and 1 for phenylalanine.

Amino Acids↗