Brillouin study of photopolymerization process of two-monomer systems.

The results of Brillouin scattering investigations of two-component system: 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane/polyethylene glycol methacrylate (bis-GMA/PEGMM) containing 0, 30, 50, 70, 85 and 100 mol% of PEGMM are presented. For the first time the Brillouin spectroscopy was used to monitor the progress of the polymerization process. The polymerization was initiated by ultraviolet radiation (λ=365 nm), at temperature 20°C and 40°C. Some of the physical parameters characteristic for this system such as velocity V, adiabatic compressibility ß(ad) and attenuation coefficient α of the acoustic waves have been estimated from Brillouin spectra as a functions of the polymerization time. The obtained results have been discussed in terms of changes of the elastic properties of the two-component system occurring during polymerization process and their dependence on bis-GMA/PEGMM system composition.

Brillouin spectroscopy studies of two-component polymerizable liquid system: 2,2-bis[4-(2-hydroxymethacryloxypropoxy)phenyl]propane/benzyl methacrylate.

Brillouin spectroscopy was used to investigate viscoelastic properties of a two-component system consisting of a high viscosity liquid (HVL) and a low viscosity liquid (LVL), both able to polymerize. The model liquids were: 2,2-bis[4-(2-hydroxymethacryloxypropoxy)phenyl]propane (abbreviated as bis-GMA, HVL) and benzyl methacrylate (BzMA, LVL). The viscosity of the system was regulated by changing the monomer ratio. Hypersonic velocity and attenuation coefficient were investigated in a temperature range covering viscoelastic relaxation process. The dependence of the longitudinal viscosity on the system composition was determined. Additionally, the Brillouin studies were accompanied by some supplementary experimental methods, like low frequency shear viscosity measurements and observations of phase transitions by differential scanning calorimetry (DSC). The investigated monomer mixtures were then polymerized in a light-induced process and the polymerization kinetic curves were measured to find the possible correlation between the viscoelastic properties of the monomer mixture (as observed by Brillouin spectroscopy) and the polymerization course.

Elastic properties of some selected two-monomer systems as studied by Brillouin spectroscopy.

We present results obtained by Brillouin scattering method for four two-component systems comprising of a high viscosity monomer and a low viscosity monomer. The monomers used were crosslinking (divinyl) or linear (monovinyl) ones. The investigated systems were: divinyl/divinyl-bis-GMA/TEGDM; divinyl/monovinyl-bis-GMA/PEGMM; monovinyl/divinyl-bis-MGMA/TEGDM and monovinyl/monovinyl-bis-MGMA/PEGMM; they were formulated at various molar ratios. The measurements have been performed in temperature range 293-353 K. The following physical parameters characterizing the investigated systems were estimated: hypersonic velocity V, attenuation coefficient α and adiabatic compressibility ß, all as a function of temperature and monomer molar ratio. The obtained results have been discussed in terms of the influence of the system composition and viscosity on their elastic properties. Speed of changes of the adiabatic compressibility ß as derivative have been also discussed in terms of both, the temperature as well as the component of molar ratio.

The influence of phenothiazine derivatives on doxorubicin treatment in sensitive and resistant human breast adenocarcinoma cells.

Breast cancer is commonly treated by various combinations of surgery, radiation therapy, chemotherapy and hormone therapy. Most cancers either are increasingly resistant to any initial treatment or acquire resistance to a broad spectrum of anticancer drugs over time. Combination of more than one drug or combination with multidrug resistance (MDR) modifiers will possibly support the efficiency of the applied therapy. Understanding the MDR mechanisms in malignancies is crucial for developing novel strategies for treatment. The main goal of our study was to determine the cytostatic effect of doxorubicin in combination with phenothiazine derivatives (PD; promazine and triflupromazine) in doxorubicin-sensitive (MCF-7/WT) and -resistant (MCF-7/DOX) human breast adenocarcinoma cell lines. We determined cytotoxicity of the investigated compounds (MTT assay) after 24 and 48 h. The effect of phenothiazine derivatives was evaluated and doxorubicin localization was performed using confocal microscopy. The mode of the cell death was examined by the comet assay. We also determined the expression of P-glycoprotein (P-gp), which is a membrane-associated protein responsible for the multidrug resistance.

Genetic counseling in carriers of reciprocal chromosomal translocations involving long arm of chromosome 16.

Families with balanced chromosomal changes ascertained by unbalanced progeny, miscarriages, or by chance are interested in their probability for unbalanced offspring and other unfavorable pregnancy outcomes. This is usually done based on the original data published by Stengel-Rutkowski et al. several decades ago. That data set has never been updated. It is particularly true for the subgroup with low number of observations, to which belong reciprocal chromosomal translocations (RCTs) with breakpoint in an interstitial segment of 16q. The 11 pedigrees from original data together with the new 18 pedigrees of RCT carriers at risk of single-segment imbalance detected among 100 pedigrees of RCT carriers with breakpoint position at 16q were used for re-evaluation of the probability estimation for unbalanced offspring at birth and at second trimester of prenatal diagnosis, published in 1988. The new probability rate for unbalanced offspring after 2 : 2 disjunction and adjacent-1 segregation for the total group of pedigrees was 4 +/- 3.9% (1/25). In addition, the probability estimate for unbalanced fetuses at second trimester of prenatal diagnosis was calculated as 2/11, i.e. 18.2 +/- 11.6%. The probability rates for miscarriages and stillbirths/early deaths were about 16 +/- 7.3% (4/25) and <2% (0/25), respectively. Considering different segment lengths of 16q, higher probability rate (0/8, i.e. <6.1%) for maternal RCT carriers at risk of distal 16q segment imbalance (shorter segment) was obtained in comparison with the rate (0/10, i.e. <4.8%) for RCT at risk of proximal segment imbalance (longer segment). It supports findings obtained from the original data for RCT with other chromosomes, where the probability for unbalanced offspring generally increased with decreasing length of the segments involved in RCT. Our results were applied for five new families with RCT involving 16q, namely three at risk of single-segment imbalance [t(8;16)(q24.3;q22)GTG, ish(wcp8+,wcp16+;wcp8-,wcp16+), t(11;16)(q25;q22)GTG, and t(11;16)(q25;q13)GTG] and two with RCT at risk of double-segment imbalance [t(16;19)(q13;q13.3)GTG, isht(16;19)(q13;q13.3) (D16Z3+,16QTEL013-D19S238E+,TEL19pR-; D16Z3-, D19S238E-,TEL19pR+), and t(16;20)(q11.1;q12)GTG, m ish,t(16;20)(wcp16+,wcp20+;wcp16+,wcp20+)]. They have been presented in details to illustrate how the available empiric data could be used in practice for genetic counseling.

Photofrin--factor of photodynamic therapy induces apoptosis and necrosis.

Photodynamic therapy (PDT) causes irreversible photodamage of tumor and other malignant tissues. The effect of reactive oxygen species generation in the presence of photofrin (HpD) was studied. The studies were performed on endothelial cell line from foetal aorta of calves and on normal fibroblasts cell line (3T3 -Balb) and also on malignant line (A431). The cells were grown in presence of photofrin at different time intervals. Time of interaction of photosensitiser with cells was very important. Short time of exposure of the cells to photofrin induced mostly apoptosis in normal cells and apoptotic or necrotic changes in malignant cells. Longer effect of these factors on cells provoked necrosis. The factors of PDT influence dynamic changes of SOD and CT activity. It was dependent on the intensity of factors. These results strongly suggest that HpD has an effect on generation of ROS, which are a signal for development of morphological changes (apoptosis or necrosis) in normal and malignant cells.

[The influence of vitamin A on production of oxygen free radicals and activity of granulocyte catalase in patients with chronic bronchitis]. / Wplyw witaminy A na wytwarzanie wolnych rodników tlenowych i aktywnosc katalazy granulocytów u chorych na przewlekle zapalenie oskrzeli.

The effect of vitamin A on granulocyte chemiluminescence (CT) and catalase activity was studied in 16 patients with COPD. The results obtained show a significant decrease of CL and a significant increase of granulocyte CT activity after incubation with vitamin A, particularly in nonsmoking subjects. This study showed a significant decrease of CT activity after incubation of granulocyte with hydralazine both in cigarette smokers or nonsmokers.

[The influence of n-acetylcysteine on chemiluminescence of granulocytes in peripheral blood of patients with chronic bronchitis]. / Wplyw N-acetylcysteiny na chemiluminescencje granulocytów krwi obwodowej u chorych na przewlekle zapalenie oskrzeli.

The effect of NAC on exacerbation of chronic obstructive pulmonary disease (COPD) may be due to its mucolytic properties due to the thiol group of NAC and to its reducing and antioxidant properties. It has been postulated that NAC may protect lung cells from inhaled oxidants or oxidants produced by inflammatory leukocytes by increasing intra and extra cellular GSH. The FMLP induced granulocyte chemiluminescence (CL) in 6 healthy and 12 patients with COPD was determined. Peripheral blood polymorphonuclear leukocytes were incubated with NAC. The results obtained show a significant decrease of CL after incubation with NAC in both groups. We also found higher CL in healthy subjects than patients with COPD. This study showed a significant increase of FVC, FEV1 and a significant decrease of granulocyte CL after treatment with oral NAC 200 mg three times daily for 3 weeks.

[Trial application of transfection tests in feasibility studies for transforming DNA in white blood cells of patients with chronic lymphatic leukemia]. / Próba zastosowania testów transfekcyjnych w badaniach wlasciwosci transformujacych DNA z krwinek bialych chorych na przewlekla bialaczke limfatyczna.

Transfection technique with the use of high molecular DNA was applied for the investigations of peripheral blood white cells DNA transforming properties in patients with chronic lymphatic leukemia B. Using transfection tests in liquid medium (focus assay) and colony forming in soft agar, the differences in L(tk-) cells transformation were noted following an addition of neoplastic DNA. Medium collected over transformants has shown mitogen properties in micro-mitogen tests on cells BALB/c 3T3. No correlation between clinical stage of the disease and the results of tests was observed.

The effect of temperature on catalytic function of glyceraldehyde-3-phosphate dehydrogenase from muscle of pig and carp Cyprinus carpio.

1. The temperature dependence of the kinetics of glyceraldehyde-3-phosphate dehydrogenase from white muscle of carp and skeletal muscle of pig was examined. 2. The Km values of carp muscle enzyme were stable over the temperature range 5-35 degrees C, but increased for pig muscle enzyme with increasing temperature. 3. The Arrhenius plot for pig muscle enzyme is linear but non-linear for carp muscle enzyme. 4. The differences indicate that glyceraldehyde-3-phosphate dehydrogenase from white carp muscle may contribute to the adaptive mechanism of carp to varied temperature conditions.

Purification and some properties of glyceraldehyde-3-phosphate dehydrogenase from carp muscle.

Glyceraldehyde-3-phosphate dehydrogenase was purified from carp white muscle. On CM-Sephadex chromatography two well separated active peaks were obtained. Both of them show a single protein band on gel electrophoresis and have the same molecular and kinetic properties; they differ only by the amount of bound NAD, the enzyme in the second peak being coenzyme-free. Significant differences were observed between the properties of carp and pig muscle enzymes. Glyceraldehyde-3-phosphate dehydrogenase from carp is more resistant to heat and proteolytic inactivation. Moreover NAD does not protect it against inactivation. Only one sulphydryl group per subunit is able to react with 5,5'-dithiobis(2-nitrobenzoate), irrespective of the kind of the buffer. The structure of glyceraldehyde-3-phosphate dehydrogenase from white muscle of carp seems to be more compact and therefore more inaccessible to some agents than that of the enzyme from pig muscle.

Glyceraldehyde-3-phosphate dehydrogenase. Investigation on the regions responsible for self-assembly of subunits.

1. In glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (EC 1.2.1.12) the four S-loop form the core of the tetramer. 2. Amino acid sequence of the S-loop of the regions of GAPDH from carp muscle was established through the analysis of tryptic digests of the enzyme treated alternatively with bromocyanate and o-iodosobenzoic acid. 3. Enzyme had been oxidized with performic acid. After treatment with trypsin the peptide mixture was fractionated into fragments. 4. CNBr cleavage of this enzyme was performed after S-carboxymethylation. The respective cyanogen bromide fragments have been isolated and characterized. 5. The procedure of protein fragmentation by o-iodosobenzoic acid used to split tryptophanyl peptide bonds. 6. Each peptide obtained after enzymatic or chemical fragmentation was purified to homogeneity by Bio-Gel or Sephadex chromatography, high voltage electrophoresis and descending paper chromatography and characterized by electrochromatography, N- and C-terminal sequence and amino acid composition. 7. The results are compared with those obtained from studies on GAPDH from other sources.

Localization of arginyl residues modified with butanedione in glyceraldehyde-3-phosphate dehydrogenase from pig muscle.

Glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12) from pig muscle was inactivated by incubation with butanedione in triethanolamine buffer, pH 8.3. The inactivation was reversible after short treatment with butanedione; it became irreversible after 12-15 h, with a concomitant loss of two arginyl residues per subunit. The modified enzyme was digested with TPCK-trypsin and the peptides were purified by chromatography and electrochromatography. Two new peptides were obtained as the result of modification. From their partially determined sequence the modified arginyl residues were identified as Arg-13 and Arg-231 in the primary structure of pig muscle enzyme.

The sites of chymotrypsin action on the pig muscle glyceraldehyde 3-phosphate dehydrogenase during limited proteolysis.

1. The sites of chymotrypsin action on glyceraldehyde 3-phosphate dehydrogenase (D-glyceraldehyde 3-phosphate) : DNA+ oxidoreductase (phosphorylating), EC 1.2.1.12) was established; limited proteolysis by chymotrypsin results in lowering of the phosphorolytic activity of the enzyme without affecting its oxidative activity. 2. The low-molecular fraction of the chymotrypsin digest separated by Sephadex G-100 chromatography, was fractionated on Bio-gels. Determination of the amino acid composition of the nine peptides isolated, and of their amino acid sequence, permitted to relate cleavage of Leu-64, Trp-84, Leu-109, Leu-141, Phe-165, Lys-212, Val-239, Leu-242, Leu-271 (or Phe-315) bonds in the enzyme to the decrease of the phosphorolytic activity.