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Biomedical subjects

M Konieczny

Publications and source records attributed to M Konieczny.

At least 19 recordsLinked to original sources
PubMed2004

Soft effective interactions between weakly charged polyelectrolyte chains.

We apply extensive molecular dynamics simulations and analytical considerations in order to study the conformations and the effective interactions between weakly charged, flexible polyelectrolyte chains in salt-free conditions. We focus on charging fractions lying below 20%, for which case there is no Manning condensation of counterions and the latter can be thus partitioned in two states: those that are trapped within the region of the flexible chain and the ones that are free in the solution. We examine the partition of counterions in these two states, the chain sizes and the monomer distributions for various chain lengths, finding that the monomer density follows a Gaussian shape. We calculate the effective interaction between the centers of mass of two interacting chains, under the assumption that the chains can be modeled as two overlapping Gaussian charge profiles. The analytical calculations are compared with measurements from molecular dynamics simulations. Good quantitative agreement is found for charging fractions below 10%, where the chains assume coil-like configurations, whereas deviations develop for charge fraction of 20%, in which case a conformational transition of the chain towards a rodlike configuration starts to take place.

Journal Article↗
PubMed1996

[The effect of ovariectomy in women on metabolism of phenazone].

The studies were aimed to prove the effect of surgical ovariectomy in women with normal estrogen levels on the metabolism of medicaments in the hepatocyte. Phenazone, which has lost its significance as a medicament, was used as a model substance since it is often used as a preparation in the pharmacokinetic investigations. Phenazone levels in sera of women's blood were tested twice. The first test was carried out in the women before the operation which included among other things a surgical ovariectomy. Before the operation, the women manifested normal estrogen levels. The test was repeated 30 days after the operation. Phenazone levels were again tested after oral administration of phenazone in the dose of 18 mg/kg body mass. Before each test, the women were checked twice for the clinical and laboratory parameters of liver functions. Phenazone levels were determined seven times in the blood serum at 3- to 6-hour intervals within 24 hours. The determinations were performed using the Brodie (Brody) method. Average phenazone levels in blood sera were given mathematical analysis in the women before and after surgical ovarlectomy. The two curves were compared to obtain statistically significant differences in most pharmacokinetic parameters. It was shown that sudden drop in estrogen levels due to surgical ovariectomy causes a diminished constant elimination (K), prolongation of half-life (t0.5), an increase in distribution volume (Vd), its reduced derivative (Vd) and increased distribution volume calculated from the area under the curve (VdAUC). It points to the effect of estrogens on the metabolism of medicaments in the liver and indicates a careful dosage of some medicines in chronic use which have a long biological half-life in post-menopausal women and in women following surgical ovariectomy.

Adult↗
PubMed1994

In the search for new anticancer drugs. 26. A comparison of anticancer activities of several TEPA, thio-TEPA, Seleno-TEPA, and azetidine analogs, including congeners containing an aminoxyl moiety.

A series of TEPA, Thio-TEPA, Seleno-TEPA, and azetidine analogs, including congeners containing an aminoxyl moiety, were synthesized and evaluated in vivo for anticancer activity against the murine lymphocytic leukemia P388. All aziridine derivatives were found to be active with an increase in life span ranging from 42% to 272%, and all azetidine analogs were rated as inactive with one marginal exception. An attempt was made to rationalize the results on the basis of the lipophilic properties of the compounds. The most active compound (8) possessed the most balanced lipophilic properties, corresponding to a log P value near zero.

Animals↗
PubMed1991

Surgical management of major varicose veins of the lower limb using a pneumatic tourniquet.

A technique to facilitate ablation of varicose veins is described. We have tested this technique in 25 patients. A pneumatic tourniquet is place on the lower limb during operation for a maximum of 90 minutes. This technique allows the operative field to remain dry and clean, and the resulting bloodless field makes the operation easier and faster. Because the veins are empty, they are removed more easily and completely, even in cases of severe dermatitis or adhesion.

Air↗
PubMed1988

1,4-naphthoquinone-2-sulfonic acid derivatives coupled to dextran as carriers for interferon.

Three derivatives of 1,4-naphthoquinone-2-sulfonic acid possessing the fragments of Cibacron Blue (CB) were synthesized and bound to Dextran T 2000 by ether binding. Polymers IVD, VD and VID were incubated with interferon (IFN) to obtain complexes: carrier-IFN. It was found that polymer VID has weaker affinity to mouse IFN-beta/alpha and to human IFN-beta than Blue Dextran. The polymers IVD and VD had no affinity to the interferon.

Affinity Labels↗
PubMed1987

New benzoquinone derivatives of dextran as carriers for interferon.

A series of derivatives of benzoquinone-2-sulfonic acid (I-VI) containing constituents of the structure of Cibacron Blue (CB) was synthesized and bound to dextran T 2000 with ether binding (VII-XII). Two dextran polymers XI and XII showed in biological assays high affinity for interferon (IFN).

Binding Sites↗
PubMed1984

New derivatives of blue dextran binding and stabilizing human or mouse interferons.

Mouse or human interferons were found to bind strongly to Blue Dextran 2000 and its eight new derivatives (compound VII to XIV covalently bound to Dextran 2000). The congeners of BD were pale violet or grey. The affinity of Blue Dextran and its congeners to interferons were: IFN-beta greater than IFN-alpha greater than IFN-gamma. The carriers stabilized the antiviral activity of beta-type of interferon during storage at 4 degrees C.

Animals↗
PubMed1982

Metabolism and covalent binding to DNA of 7-methylbenzo(a)pyrene.

The ultimate carcinogenic form of benzo(a)pyrene (BP) is thought to result from metabolic activation at the 7 to 10 positions. Substitution by a methyl group at these positions would be expected to inhibit strongly their metabolism even though 7-methylbenzo(a)pyrene (7-MeBP) has been reported to be carcinogenic in some tumor models. The metabolism of 7-MeBP was, therefore, studied using both microsomal preparations and whole cells, the products being analyzed by high-pressure liquid chromatography, fluorescence spectrophotometry, and mass spectrometry. These studies revealed that many of the expected metabolites were formed by microsomes, but in addition 7-MeBP yielded a compound which was isolated and identified as trans-7,8-dihydro-7,8-dihydroxy-7-methylbenzo(a)pyrene. These results indicate that, despite the presence of a methyl group at the 7 position, a substituted BP can undergo the same initial metabolic activation as BP itself. However, in contrast to BP, the 7,8-dihydrodiol formed from 7-MeBP was almost racemic, and neither enantiomer was very active in the Ames bacterial mutagenesis assay when compared with trans-7,8-dihydro-7,8-dihydroxybenzo(a)pyrene. The metabolism of 7-MeBP was also studied in 10T1/2 cells. The hydrocarbon was metabolized readily and bound to DNA of the cells to about one-eighth of the level found for BP. However, no 7,8-dihydro-7,8-dihydroxy-7-methylbenzo(a)pyrene could be detected in the culture medium.

Animals↗
PubMed1982

Studies on the Ritter reaction. I. Synthesis of 3-/5-barbituryl/-propanesulfonic acids with anti-inflammatory activity.

Under the condition of the Ritter reaction the allyl group bound to C5 of the barbituric ring was observed to transform, due to addition of sulfuric acid, into beta-sulfooxy-propane-sulfonic or beta-hydroxy-propanesulfonic group. Inner anhydrides of the structure of beta-sulfone or carbyl sulfate are the intermediate products of these reactions. Well water-soluble calcium salts of the synthetized acids were pharmacologically analyzed.

Acetonitriles↗
PubMed1980

Dextran T fractions substituted with cibacron blue F3G-A as carriers for mouse interferon.

Commercial dextran T fractions covering the molecular weight (Mt) range 10,000-2,000,000 were substituted with a covalently linked chromophore: Cibacron blue F3G-A. Mouse interferon (IF) was found to bind firmly to the blue dextran (BD) fractions. Fractions of high Mt (BD 2000 and BD 500) associated with IF are precipitated from the solution by polyethylene glycol (PEG). Fractions of lower Mt (BD 70, BD 40 and BD 10) associated with IF are only partially, if at all, precipitated by PEG. However, when BD-IF complexes of various Mt were analyzed by chromatography on Sephadex G-150, IF activity migrates together with BD and not at the distance characteristic of native IF. These data suggested that IF is bound to various BD fractions. BD-IF complexes of various Mt have almost the same antiviral and anticellular activities as native IF. BD-IF complexes are neutralized to a greater extent by antibody than native IF. Clearance of BD 70-IF complex from the mouse peritoneal cavity is slightly slower than native IF. However, the i.v. clearance of both forms of IF is almost the same.

Animals↗
PubMed1978

Synthesis of new sulfuric derivatives of allobarbital (5,5-diallylbarbituric acid) with anti-inflammatory activity.

It was found that allyl group of alkenes Ia-Ig is transformed into 3'-sulfo-2'-sulfatopropyl or beta-methyl-beta-sulton groups in reaction of addition under action of concentrated sulfuric acid in the presence of methyl cyanide. It was stated that this reaction is competitive to the Ritter reaction. Soluble in water calcium salts IV obtained from compounds Ia and Ib exhibited strong antiinflammatory activity.

Anti-Inflammatory Agents↗