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M Stupar

Publications and source records attributed to M Stupar.

13 recordsLinked to original sources
PubMed2005

Hydrophilic gels containing chlorophyllin-loaded liposomes: development and stability evaluation.

The aim of this study was to develop and characterize hydrophilic gels containing chlorophyllin(CHL)-loaded liposomes as well as to evaluate their stability. Two different CHL-loaded liposome dispersions using non-hydrogenated and hydrogenated soybean lecithin were prepared, characterized for their particle size, polydispersity index and trapping efficiency and incorporated in Carbopol 940 NF hydrogel. The gels obtained were analyzed for flow properties, pH values and CHL content. The control liposome-free gel was obtained by incorporating the CHL solution in the hydrogel. The stability of the gels was evaluated in terms of rheological properties, pH values and CHL content during 6 months' storage at 20 +/- 2 degrees C. Suitable gel formulations for topical use were obtained revealing shear-thinning plastic flow behaviour without significant thixotropy during the whole period of examination. High yield values of the samples during the whole period indicated a long-term stability of the gel formulations. The gel formulations expressed a mild acid value acceptable for topical preparations. After 6 months' storage the CHL content was highest in the gel containing non-hydrogenated lecithin liposomes, followed by the gel containing hydrogenated lecithin liposomes and liposome-free gel, indicating that the encapsulation of CHL in liposomes led to a greater stability of CHL.

Acrylic Resins↗
PubMed1998

A gene coding for an RPS2 protein is present in the mitochondrial genome of several cereals, but not in dicotyledons.

A gene coding for a protein that shows homologies to prokaryotic ribosomal protein S2 is present in the mitochondrial (mt) genome of wheat (Triticum aestivum). The wheat gene is transcribed as a single mRNA which is edited by C-to-U conversions at seven positions, all resulting in alteration of the encoded amino acid. Homologous gene sequences are also present in the mt genomes of rice and maize, but we failed to identify the corresponding sequences in the mtDNA of all dicotyledonous species tested; in these species the mitochondrial RPS2 is probably encoded in the nucleus. The protein sequence deduced from the wheat rps2 gene sequence has a long C-terminal extension when compared to other prokaryotic RPS2 sequences. This extension presents no similarity with any known sequence and is not conserved in the maize or rice mitochondrial rps2 gene. Most probably, after translation, this peptide extension is processed by a specific peptidase to give rise to the mature wheat mitochondrial RPS2.

Amino Acid Sequence↗
PubMed1993

Reduction of 1-nitroso-2-naphthol by NADPH in the presence of liver microsomes.

1. The endogenous, NADPH-supported production of H2O2 and of O2-.-radicals in liver microsomes, was very strongly enhanced in the presence of 1-nitroso-2-naphthol. 2. A 30-fold induction by NON was the consequence of its direct reduction to NON-radicals, catalyzed by microsomal NADPH:cytochrome P450 reductase. 3. Nitroso radicals reduce molecular oxygen to superoxide anion radicals, which were readily dismutated by superoxide dismutase to hydrogen peroxide. 4. O2-.-radicals were the sole precursors of all NON-induced production of H2O2 in liver microsomes.

Animals↗
PubMed1984

Inhibition by isoproterenol of the passive potassium efflux from pigeon erythrocytes.

Pigeon erythrocytes were carefully washed in an isotonic neutral buffer, devoid of potassium, and the rate of passive unidirectional efflux of potassium from the cells into a K+-free medium was measured after 20 min, at 40 degrees C. Isoproterenol inhibits K+-efflux by 35-45%, at a cell concentration of 1%; the isoproterenol effect is mediated by beta-adrenergic receptors. Cyclic AMP mimics the effect of isoproterenol, but at 4-5 orders of magnitude higher concentrations. Cyclic AMP increases 20-fold the phosphorylation of purified cell membranes by [gamma 32P]ATP.

Adenosine Triphosphate↗
PubMedDate not supplied

Genetic variation at the apoB 3'hypervariable region in a Serbian population.

We investigated common length polymorphism caused by a variable number of tandem repeats in the hypervariable region located at the 3' end of the human apolipoprotein B gene in 696 Serbian (Belgrade area) unrelated individuals of both genders. After using the polymerase chain reaction to amplify this polymorphic region, 17 different alleles, containing 22-54 repeats, were distinguished. The bimodal distribution and the heterozygosity index (average 0.71) obtained in both genders are similar to those reported for other Caucasian populations. However, the HVE34 allele was found to be the commonest in both female and male samples. There was also a lower frequency of the HVE > 36 alleles than in other Caucasian populations studied.

Apolipoproteins B↗