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Biomedical subjects

M Woźniak

Publications and source records attributed to M Woźniak.

At least 19 recordsLinked to original sources
PubMed1995

Protective effect of 4-hydroxy-TEMPO, a low molecular weight superoxide dismutase mimic, on free radical toxicity in experimental pancreatitis.

Rats develop acute pancreatitis when infused iv for 3 h with cerulein (10 micrograms/kg/h). Autopsies of the pancreas seen by light microscope show interstitial edema, acinar cells vacuolization, and leukocyte margination in pancreatic capillaries; under electron microscope, severe damage concerning mitochondrial and zymogen granules structures are apparent. Particularly, swelling of the mitochondria and disruption of mitochondrial cristae was observed as well as formation of large vacuoles arising from zymogen granules and liposome fusion. A significant increase of lipid hydroperoxide level in the pancreatic tissue was observed. The purpose of this study was to evaluate the effect of 4-hydroxy-TEMPO--a low-mol-wt superoxide dismutase mimic--in a rat cerulein model of acute pancreatitis, with the expectation that free radical mediated hydroperoxide formation and tissue damage may be reduced significantly. Twenty-one male Wistar rats were divided into three groups: Group 1 (n = 5) served as a control and was infused iv for 3 h with physiologic saline; Group 2 (n = 8) was infused i.v. for 3 h with cerulein 10 micrograms/kg/h; and Group 3 (n = 8) infused i.v. both with cerulein and 4-hydroxy-TEMPO 22.6 mg/kg/h. Pancreatic tissue damage was quantified by measuring lipid hydroperoxide (LOOH) level, the weight of the organ, and by light and electron microscopic examination. 4-hydroxy-TEMPO penetration across cellular membrane barriers was quantified by ESR spectrometric measurements of 4-hydroxy-TEMPO concentration in pancreatic tissue samples and pancreatic juice as well. Administering 4-hydroxy-TEMPO to rats resulted in preventing both lipid hydroperoxide formation and severe morphological damage. 4-hydroxy-TEMPO crossed cellular membrane barriers and was excreted to pancreatic juice. Infusion of 4-hydroxy-TEMPO appears to prevent pancreatic injury caused by free radicals in experimental cerulein pancreatitis.

Acute Disease↗
PubMed1994

[Can TNF-alpha and IL-6 be helpful in assessment of chronic hepatitis in children?].

The purpose of the work was an assessment of TNF-alpha and Il-6 concentrations in 34 children with diagnosed chronic hepatitis. In all studied patients the values of TNF-alpha and Il-6 concentration were slightly increased. The correlations calculated between TNF-alpha and Il-6 concentrations calculated between TNF-alpha and Il-6 concentrations and laboratory parameters (laboratory indicators of hepatitis activity--AlAT; liver function indicators--prothrombin index, bilirubin concentration, bile acid concentration, alkaline phosphatase activity, anti-pyrin half-life) were non-significant in Spearman non-parametric test (p > 0.005) except for the correlation between albumin and TNF-alpha concentrations. No statistically significant differences of TNF-alpha and Il-6 concentrations were found between groups of patients with active and persistent hepatitis; groups with and without cirrhosis as well as between groups with and without portal hypertension. Normal or slightly increased TNF-alpha and Il-6 concentrations, observed in chronic hepatitis in children should be explained by compensated liver function in such patients.

Child↗
PubMed1994

Synthesis and pharmacological properties of some new 3-(2-N,N-dialkylaminoethyl)-pyrido [2,3-d]-pyrymidin-4-ones.

The following new derivatives of pyrido [2,3-d]-pyrimidin-4(3H)-one were synthesized: 3-(2-N,N-dimethylaminoethyl), 3-(2-N-pyrolidynylethyl), 3-(2-piperidinylethyl) and 3-(2-N-morpholidinylethyl). Their chemical structures were confirmed by MS, IR and 1H NMR spectroscopic data. Newly synthesized compounds were investigated pharmacologically for their central properties in mice and rats. It was shown that compound [III] showed anxiolytic action in the four-plate test and two compounds produced analgesic effects in mice.

Analgesics↗
PubMed1991

Robust trend analysis in predicting histamine provocation concentration.

Trend analysis is used to predict the histamine provocation concentration PC20 during the so-called challenge test, where increasing doses of the bronchoconstricting agent are given to a patient and the spirometric examination is subsequently performed. Classical least-squares analysis of trends as well as least absolute deviations analysis are compared. The results are interesting and promising from a statistical as well as medical point of view. The methods presented can be applied to many practical problems in medicine.

Algorithms↗
PubMed1988

The influence of phosphatidate bilayers on pig heart AMP deaminase. Crucial role of pH-dependent lipid-phase transition.

Phosphatidate bilayers composed of dilauroylphosphatidate, dimyristoylphosphatidate, dipalmitoylphosphatidate and dioleoylphosphatidate were prepared. Their interaction with AMP deaminase isolated from pig heart was investigated. Dioleoylphosphatidate bilayers were found to exert non-competitive inhibition on the AMP deaminase with a Ki of 15 x 10(-6) M. This inhibition is three orders of magnitude stronger than that exerted by orthophosphate. The phosphatidate species containing saturated fatty acids were either non-inhibitory or inhibited enzyme activity rather poorly. However, alkalinization of the medium from pH 6.5 to pH 7.9 led to the inhibition of pig heart AMP deaminase by dilauroylphosphatidate bilayers. This was accompanied by the fluidization of the saturated phosphatidate species, i.e. the lowering of their phase transition temperature in alkaline pH, as measured by light-scattering and fluorescence scans. The possible significance of these findings for the regulation of AMP deaminase activity in vivo by natural membranes is discussed.

AMP Deaminase↗
PubMed1988

Azimexone and cysteine hydrazide in the treatment of allergic encephalomyelitis.

In the course of allergic encephalomyelitis (EAE) in chickens, azimexone suppressed the production of the specific IgM immunoglobulins. Moreover, it decreased the level of haptoglobin and sialic acid but stimulated the activity of antitrypsin. It was also observed to reduce the production of the plasmatic cells in the spleen. L-cysteine hydrazide hydrochloride decreased the level of sialic acid in EAE; intensified the activity of trypsin inhibitor and exerted no effect upon the level of antimyelin antibodies.

Animals↗
PubMed1987

Diversity of the effect of phosphatidylcholine and sphingomyelin on adenylate deaminase from pig brain.

Liposomes made of sphingomyelin were found to inhibit both ATP-activated and non-activated AMP deaminase from pig brain, in contrast to liposomes made of egg yolk phosphatidylcholine which exhibited an activating effect on the ATP-activated enzyme, being without effect on AMP deaminase in the absence of ATP. Dioleoylphosphatidylcholine exerted a similar effect as egg yolk phosphatidylcholine but dipalmitoylphosphatidylcholine was without effect.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1986

Effect of inhibition of carbohydrate-mediated endocytosis on catabolism of equine haptoglobin and its complex with haemoglobin in hen.

Equine haptoglobin (Hp) and haptoglobin-haemoglobin complex (Hp-Hb) are metabolised in the hen parenchymal cells of the liver in which endocytosis was inhibited by agalacto-orosomucoid (AGOR) or native orosomucoid (OR). The intravenous administration of AGOR or OR together with [125I]Hp slightly decreased clearance of Hp from circulation. This suggested that heterologous Hp could be catabolised by the alternative pathway following the uptake by the liver RES cells. Administration of the [125I]Hp-Hb complex and AGOR was of no effect on the clearance of the Hp-Hb complex.

Animals↗
PubMed1985

Behavior of haptoglobin in experimental allergic encephalomyelitis in chickens.

Concentration of haptoglobin (Hpc) in serum of chickens with inflammation and allergic encephalomyelitis (EAE) was determined. Chickens with aseptic inflammatory state revealed 2.5 times higher concentration of Hpc while in the course of EAE only small increase was observed. Administration of immunomodulator--isoprinosine, resulted in elevation of Hpc level as compared to nontreated chickens.

Animals↗
PubMed1984

Catabolism of avian and mammalian haptoglobins and their complexes with haemoglobin in chicken.

The following 125I-labelled preparations of human and chicken haptoglobins (Hph, Hpc) and their complexes with human and chicken haemoglobins (Hph-Hbh, Hpc-Hbc, Hph-Hbc) were injected intravenously to chickens. Hpc exhibited long half-life time (t1/2 = 12.9 hr), whereas the homologous Hpc-Hbc complex disappeared from circulation faster (t1/2 = 3.1 hr). This suggested that the Hpc-Hbc complex was internalized by the receptor-mediated process in the avian liver. Mammalian Hph-Hbh complex was eliminated from chicken circulation rather fast (t1/2 = 0.5 hr) in contrast to "mixed" Hph-Hbc complex which was characterized by the relatively long half-life time (t1/2 = 4.4 hr). Hph-Hbc complex displayed 1-2 sites for binding an anti-Hph antibody i.e. less than Hph-Hbh or Hph-Hbc complexes. The Hph binding with Hbc seems to be weaker than with mammalian haemoglobins.

Animals↗
PubMed1983

Effect of inhibited endocytosis in sinusoidal liver cells on catabolism of equine haptoglobin and haemoglobin in the hen.

Catabolism of equine haptoglobin (Hp), haptoglobin-haemoglobin complex (Hp-Hb) and haemoglobin (Hb) in the hen was studied in the liver reticuloendothelial system (RES) in which endocytosis of protein was inhibited by aggregated denatured albumin (Agr-Alb). Intravenous injection of Agr-Alb together with equine [125I]Hp, [125I]Hp-Hb or [125I]Hb partially inhibited elimination of these proteins from hen circulation. The decrease of clearance was less pronounced when the labelled proteins were introduced 30 min after Agr-Alb injection due to stimulation of phagocytosis in RES by Agr-Alb. Elimination of equine proteins (Hp, Hp-Hb and Hb) from hen circulation by RES is only one of the possible metabolic fates of these proteins.

Albumins↗