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J W Naskalski

Publications and source records attributed to J W Naskalski.

At least 19 recordsLinked to original sources
PubMed1998

[Chemical tests during a real time physician-patient interaction--the concept and practical problems resulting from its realization].

Laboratory tests performed at the patient's bed-side in a real time of patient-physician interaction, consist a part of a program focussed on maximal shortening of the treatment time and increase the efficiency of the applied medical procedures. A whole generation of a modern chemical analysers are presently available for use in a near patients testing. However, performing a "real time" bed-side testing by persons who are not prepared for work in medical analytics effects in a numerous mistakes both of preanalytical and analytical nature, decreasing the reliability of the obtained results. Thus, implementation of near patient testing should be based on the already elaborated procedures of quality assurance and quality control. The management of the bed side testing system, and supervision of its conformity with quality procedures should be a task of a hospital central laboratory, which on the other hand is also responsible for good compliance of bed-side results with the results provided from the laboratory. Nevertheless the prones of the bed-side tests on quality impairment, the properly organized near patient's test systems are of a great value for ICU wards, admission rooms, and general practitioners working in locations distant from the professional laboratories.

Critical Care↗
PubMed1996

Apolipoprotein E is highly susceptible to oxidation by myeloperoxidase, an enzyme present in the brain.

Apolipoprotein E, the most common apolipoprotein found in the brain, is linked to several pathologies like Alzheimer's disease. Apolipoprotein E directly binds to beta-amyloid with a strong affinity. Myeloperoxidase, a protein secreted by neutrophils and involved in the inflammatory process, is also present in the brain. In vitro myeloperoxidase oxidation of recombinant human apolipoprotein E leads to fragmentation of the protein with low concentrations of hydrogen peroxide and polymerization with higher concentrations. Comparison with bovine serum albumin shows a higher susceptibility of apolipoprotein E to myeloperoxidase oxidation, which may have importance in the Alzheimer's disease process.

Alzheimer Disease↗
PubMed1995

Immunoglobulin cleavage by hypochlorous acid treatment.

IgA, IgG and IgM were cleaved by hypochlorous acid treatment. The apparent calculated molecular masses of three polypeptides obtained from IgA were 81.1. 25.8 and 13.9 kDa. The amounts of released IgA fragments were proportional to the amount of HOCl employed. At a HOCl:IgA molar ratio above 320:1, a profound degradation of IgA polypeptide chains occurred, resulting in a yellow-coloured product. The HOCl treatment of IgG resulted in similar effects, the liberation of three fragments, one of them being of a size slightly larger than that of the light chain (30.4 kDa). The treatment of IgM with HOCl also produced three fragments: one corresponding to the monomeric IgM molecule, the second to the light chain (26.4 kDa) and the third of a size smaller than the heavy chain. The optimal protein/HOCl ratios for the degradation of IgG and IgM were 375:1 and 808:1, respectively.

Dithiothreitol↗
PubMed1994

Teaching clinical chemistry in central European countries--past and present.

Central Europe is traditionally referred to as the area occupied by the former Eastern Germany, Poland, Slovakia, Czech Republic and Hungary. In all of these countries great emphasis is placed on teaching clinical chemistry and biochemical pathology, both at undergraduate and postgraduate levels. In Czech Republic and in Poland analysis of blood, urine, body fluids, exudates and secretions as well as the fundamentals of interpretation of morbid states in biochemical terms are taught as an independent subject taking from 60 to 90 h of lectures, seminars and practical training. In Hungary, the fundamentals of clinical chemistry and biochemical pathology are included in courses of biochemistry, pathology and in clinical subjects, such as internal medicine and pediatrics. The postgraduate study of clinical biochemistry, which yields in all mid-European countries a certificate of specialisation in laboratory diagnostics (Poland), or clinical pathology (Czech Republic, Hungary), is based on at least 5 years experience in laboratory medicine and then extended studies including clinical biochemistry, haematology, cytology, microbiology, as well as the fundamentals of toxicology and immunology. A basic background in clinical practice is also required. In all countries in the area there also exists a well developed postgraduate education for laboratory workers without a medical background. These people can apply for a certificate in medical analytics (Poland), but they cannot work as clinical pathologists or laboratory diagnostic consultants.

Chemistry, Clinical↗
PubMed1994

Computer modelling of polymer decomposition by active interactions with enzyme molecules. A simulation of RNA digestion by ribonuclease.

A model of 200 polymer molecules each 70 units of length with randomly located susceptible and resistant links was elaborated. The production of mono-, di-, tri-unit and other fragments in repeating random interactions of polymer (P) with the polymer--cleaving enzyme (E) was calculated. Analysis of the calculations performed that the polymer molecules with an initial count of 70-units disappeared, imitating the first order kinetics with a half-life of about 0.37 x 10(3) P/E interactions. The production of fragments 30-69 units long was small and the life of those molecules was limited to a range from 0.5 x 10(3) to 5 x 10(3) P/E interactions. The mean polymer length decreases to one third at 10(3) P/E interactions. The production of single-unit fragments followed a sigmoidal relationship. The first reaction period, with increasing number of single-unit fragments per 10(3) P/E interactions, corresponded to a decrease in the mean polymer length to about 10 units. Then the production of one-unit fragments decreased and stopped at about 10(5) P/E interactions. This model could be used for analysis of RNA fragmentation processes by any number of RNA-ribonuclease interactions. Further development of this model would be of help in understanding the effect of various nucleotide sequences on the RNA digestion process.

Animals↗
PubMed1994

Oxidative modification of protein structures under the action of myeloperoxidase and the hydrogen peroxide and chloride system.

Myeloperoxidase of neutrophilic leukocytes (MPO) at pH 4.0 to 6.5 mediated oxidation of Cl- ions, yielding hypochloride (OCl-) which then reacted with amino acids and polypeptides. Thiol and thioether groups may be oxidized to disulfide or to sulphoxides and sulphonic acids respectively. Tryptophanyl residues yielded 2-oxoindole. Epsilon amino groups of lysine produced chloramine which, however, decomposed, yielding aldehyde residues. Bovine serum albumin treated with MPO-Cl-H2O2 system yielded derivatives with a decreased affinity to antialbumin antibodies and increased electrophoretic mobility. Albumin aldehyde derivatives were also obtained. At H2O2 molar ratio with albumin 20:1, a precipitation of albumin occurred, due to the formation of new polymeric albumin derivatives. The lysozyme (LZM) lost its enzyme activity when 1.4 to 1.8 mol of H2O2 per 1 mol of LZM was used. Addition of H2O2 above molar ratio 5:1 produced LZM polymerization to di-, tri-, tetra and pentameric derivatives. IgA exposed to the MPO-Cl-H2O2-Cl- system split into light chains (molecular weight: 25.8 kDa), heavy chains (molecular weight: 81.8 kDa) and a third polypeptide which size was half the light chain size (molecular weight: 13.9 kDa). The IgA exceeding the HOCl ratio 1:350 (mg/mumol) produced both precipitation and degradation of the IgA polypeptide structure. The treatment of IgG with HOCl released a fragment corresponding to half the light chain size, the light chain, and the heavy chain, whereas HOCl treatment of IgM released only a fragment which size was smaller than the heavy chain and another fragment which size was the same as the light chain. The MPO-Cl-H2O2 system produced many specific changes in protein structures.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Ribonuclease in human serum and urine expressed in arbitrary standard units of activity.

A definition of the arbitrary unit expressing the catalytic activity of ribonuclease (RNase) in serum and urine has been proposed. The unit defines the RNase activity solely in terms of a rate of RNase mediated decomposition of RNA-substrate. The proposed unit can be also used for expressing the results of RNase determining in former studies, if their analytical procedures have been enough precisely described. This makes possible the comparison of the recent experimental data with results obtained in other studies carried out with the use employment the nonstandardized RNase determining procedures. In this paper the comparison between the values expressing RNase activity in human serum and urine, published in various studies in years 1965-1992 and recalculated in the proposed arbitrary units, is presented.

Adolescent↗
PubMed1993

Inactivation and denaturation of some proteins by enzyme system: myeloperoxidase, chloride and hydrogen peroxide.

Changes in biological properties of serum albumin, egg white lysozyme, human serum alpha-1 antiproteinase and human leukocyte ribonuclease in effect of interaction with the enzyme system composed of myeloperoxidase from human neutrophilic polymorphonuclear leukocytes, Cl- and H2O2 were investigated. All the studied proteins lost their biological functions and were denaturated, but the amounts of hydrogen peroxide necessary to produce these effects differed remarkably for each individual protein. The alpha-1 antiproteinase ability of binding to trypsin was abolished upon employing 1.2 mols of H2O2 per mol of alpha-1 antiproteinase. The lysozyme enzymatic activity was abolished when 1.4 mols of H2O2 per mol of lysozyme were employed. Albumin decreased its binding to specific antialbumin antibodies and entirely lost the binding properties when 2 mols and about 10 mols of H2O2 per mol of albumin were employed, respectively. On the other hand 18 mols of H2O2 per mol of human leukocyte ribonuclease were necessary to inactivate this enzyme. All the mentioned proteins were protected from losing their biological functions by excess of specific amino acids with affinity to hypochlorite: Alpha-1 antiproteinase by excess of N-acetylmethionine, lysozyme by N-acetylmethionine and N-acetyl glycyltryptophane, albumin by N-acetyl derivatives of methionine, cysteine, tryptophane and lysine, whereas ribonuclease was protected from denaturation by all above mentioned amino acid derivatives. None of the studied proteins was protected from denaturation by N-acetyl tyrosine, or phenylalanine.

Chlorides↗
PubMed1990

[Proteinuria].

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Diagnosis, Differential↗
PubMed1989

Determination of ribonuclease activity in serum of patients with pancreatic necrosis. An attempt of extending the enzyme diagnosis of acute pancreatitis.

Though the substantial part of serum ribonuclease (EC 3.1.27.5) is of pancreatic origin, there are no consistent data on changes in activity of serum alkaline ribonuclease in acute pancreatitis. The recent findings suggest that the increase in ribonuclease activity refers only to patients with necrotic outcome of acute pancreatitis. The aim of this study was to reevaluate the suggestion that elevated ribonuclease activity is specifically related to pancreatic necrosis. Our studies included 57 patients with verified acute pancreatitis, and 11 patients evolving haemorrhagic or necrotic lesions of the pancreas. It was found, that the enzyme increasing in some percentage of patients with acute pancreatitis is the Poly-C avid "pancreatic" ribonuclease. This enzyme begins to increase in the 2nd or third day after onset of the disease, always after decrease in serum amylase activity down to levels close to normal range. Ribonuclease activity increased up to days 5 or 6 of the disease, and then decreased along with diminution of disease symptoms upon treatment. Correlation studies showed that increased ribonuclease activity in acute pancreatitis is related to a higher than the 2nd degree of severity of the clinical course of the disease, to pancreatic necrosis, death, diminished glomerular filtration rate, and age. Thus, pancreatic necrosis is not the exclusive factor directing the increased ribonuclease activity in acute pancreatitis, but the increased ribonuclease activity seems to be a late marker of acute pancreatitis of a severe clinical course.

Acute Disease↗
PubMed1988

Oxidation of amino acids and peptides in reaction with myeloperoxidase, chloride and hydrogen peroxide.

Oxidation was studied of N-acetyl derivatives of cystine, cysteine, methionine and glycyltryptophan employing the myeloperoxidase-Cl--H2O2 system at pH 4.5, 6.0 and 7.0. Moreover, oxidation of pentapeptide composed of Leu-Trp-Met-Arg-Phe-COOH with myeloperoxidase (donor:hydrogen-peroxide oxidoreductase, EC 1.11.1.7) and hypochlorite was also studied. It was found that amino-acid derivatives having an amino group bound to an acetyl residue react with functional groups of the side-chain. The -SH groups of N-acetylcysteine and the -SS- group of cystine oxidize to cysteic acid. Methionine residues oxidize to methionine sulphoxide, and tryptophan residues to a derivative of 2-oxoindolone. The same reaction products were obtained when respective amounts of hypochlorous acid were used instead of myeloperoxidase, Cl- and H2O2. Differences in the stoichiometry of reactions of myeloperoxidase-mediated oxidation and hypochlorite oxidation suggest differences in the reaction mechanisms of both studied systems. Interaction of the studied pentapeptide with myeloperoxidase-Cl(-)-H2O2 system as well as with hypochlorite showed that in the peptide molecule individual amino acids oxidize consecutively according to their susceptibility to oxidation. No splitting of peptide bonds was observed. Therefore, a modified peptide with methionine sulphoxide and and oxidized tryptophan incorporated into the molecule was obtained.

Amino Acids↗
PubMed1988

Lysozyme oligomers as a molecular mass standard for sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Egg white lysozyme treated with hypochlorous acid links together producing di-, tri-, tetra-, and pentameric derivatives with molecular masses ranging from 14,300 to 90,500. Similar oligomeric products may be obtained by treating lysozyme color derivatives produced by labeling lysozyme with fluorescein, trinitrobenzenesulfonic acid and 2,4-dinitrofluorobenzene, with hypochlorous acid. The oligomeric lysozyme derivatives thus obtained consist of a mixture of proteins with molecular masses equal to multiples of 14,300 (lysozyme molecular mass). This mixture can be applied as a set of molecular mass standards suitable for determination of protein molecular masses on sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Electrophoresis, Polyacrylamide Gel↗
PubMed1988

Action of myeloperoxidase-hydrogen peroxide-chloride system on the egg white lysozyme.

The enzyme system composed of human neutrophilic myeloperoxidase (H2O2-oxidoreductase, EC 1.11.1.7), H2O2 and Cl-, at pH 4.5 interacts with egg white lysozyme (EC 3.2.1.17) in several stages. In the first stage, occurring at lysozyme to H2O2 molar ratio of 1:1.4-1.8, the lysozyme loses its enzyme activity but does not yield any derivative distinguishable from the native protein on polyacrylamide gel electrophoresis (PAGE). The second stage of oxidation begins at lysozyme to H2O2 molar ratio above 1:5, producing a change in the lysozyme spectrum at 260-290 nm, and yielding protein derivatives with molecular masses equal to multiples of 14.3 kDa, i.e. the lysozyme molecular mass. This implies that an excessive oxidation of lysozyme by the myeloperoxidase-H2O2-Cl- system produces cross-linking of lysozyme molecules to di-, tri-, tetra-, and pentameric structures. At lysozyme to H2O2 molar ratio exceeding 1:12 a water insoluble white product, which consists of a set of lysozyme cross-linked derivatives, is obtained.

Acetylcysteine↗
PubMed1987

Proteinuria and excretion of ribonuclease in patients with chronic granulocytic leukaemia.

Elevated RNase activity which occurs in serum and urine of CGL patients parallels the urinary protein excretion. Acid RNase and alkaline RNase activities in urine of CGL patients, as well as acid and alkaline RNase clearance values correlated with the urinary protein concentration. Mean urinary protein level in CGL patients was approximately twice as high as that in controls. The molecular mass of CGL urinary proteins ranged from 12,000 to 80,000 proving the LMWP type of proteinuria. No particular protein contributed to the elevation of LMWPs in CGL urine. Among numerous protein fractions, albumin, acid alpha 1 glycoprotein, prealbumin RNase and in a few cases LZM were observed. The results of this study suggest that the increase of RNase activity in serum and urine reflects a more general phenomenon of increase in excretion of the entire set of LMWPs.

Adult↗