The relationship between PNP, GSTO-1, AS3MT and ADRB3 gene polymorphisms and urinary arsenic concentration among copper smelter and refinery employers.

INTRODUCTION: The aim of this study was to assess the relationship between polymorphisms of genes encoding enzymes involved in arsenic metabolism and urinary arsenic concentration in people occupationally exposed to arsenic. MATERIALS AND METHODS: The data from 113 employers directly exposed to lead, cadmium, and arsenic in copper smelter in Legnica and Glogow were collected. Urinary arsenic concentration was measured. In addition, blood level of cadmium, lead, and zinc protoporphyrins was assayed. Genetic analyses included polymorphism of PNP (rs 1130650), GSTO-1 (rs 4925), AS3MT (rs 11191439), and ADRB3 (rs4994) genes. RESULTS: Individuals occupationally exposed to arsenic compounds, who have allele T in homozygous constellation in locus rs 1130650 of PNP gene, are predisposed to lower urinary arsenic concentration, while AA homozygosity in locus rs 4925 of GSTO-1 gene may result in statistically significant higher urinary arsenic concentration. Polymorphisms of AS3MT and ADRB3 genes showed no statistically significant correlation with urinary arsenic, however, there was a tendency to higher arsenic concentration in allele A carriers in locus rs4994 of ADRB3 gene and in allele T carriers in rs 11191439 of AS3MT gene. CONCLUSION: This study indicates that arsenic absorption and metabolism depend on polymorphisms of genes encoding PNP and GSTO-1. Individuals with disadvantageous constellation of polymorphisms are more susceptible to harmful effects of arsenic exposure.

Spectroscopic Properties and Conformational Analysis of Methyl Ester of Sinapic Acid in Various Environments.

A methyl ester of sinapic acid (MESA) has recently attracted attention due to its antioxidant action. This article presents results of a study on the spectral and physicochemical properties of MESA, using quantum chemistry (QC), steady-state (absorption and fluorescence), and time-resolved fluorescence techniques (TCSPC). The pKa of the phenol group in the ground state was determined (8.6). The pKa* values in the excited state calculated from the Förster cycle (1.9) and from fluorescence spectra (8.5) differed significantly but the experimental data suggested that the first was the more probable one. Quantum yields (QYs) for both forms have been determined. The QYs were very low (0.0017 and 0.0007) for nondissociated and dissociated forms, respectively and lifetimes were very short ≤10 ps for both forms. The differences in the probability of H-bond formation in the ground and the excited states were estimated by the application of the SdP polarity scale. Dipole moments in the ground state were calculated using QC. The ratio between dipole moments in the ground and the excited state for free molecule was obtained from Bilot-Kawski (B-K) method. Analysis of all collected results suggests that radical route (through hydrogen atom abstraction) of antioxidant activity of MESA is the more probable one in a water environment at pH below 6.

Influence of UV radiation and nitrosamines on the induction of mycotoxins synthesis by nontoxigenic moulds isolated from feed samples.

The effects of UV radiation and nitrosamines on the induction of mycotoxin biosynthesis by some nontoxigenic moulds isolated from feed samples collected from Egypt and Poland was investigated. Nontoxigenic strains of Aspergillus flavus P-63, A. niger EN-200 and A. ochraceus P-157 synthesized mycotoxins (aflatoxins and ochratoxin, A) after exposure to near UV radiation for 120-210 min. Nitrosamines (DMNA and DENA) at 30 up to 1000 ppm induced the synthesis of aflatoxins by nontoxigenic species of A. flavus ES-255 and P-63 and A. niger EN 200. Near-UV radiation and nitrosamines had no influence on the induction of mycotoxin synthesis by Penicillium and Fusarium isolates. All nontoxigenic strains of Aspergilli which synthesized aflatoxins in the presence of 1000 ppm nitrosamines, also synthesized continuously aflatoxins during the next fifteen generations. Near-UV radiation and nitrosamines had a mutagenic effect on the induction of mycotoxins synthesis by nontoxigenic moulds.

Spectroscopic manifestations of flavomononucleotide dimers in polyvinyl alcohol films.

Absorption and fluorescence spectra of flavomononucleotide (FMN) in polyvinyl alcohol films (PVA) over a very wide concentration range are investigated. The dimerization constant as well as the pure monomer and dimer spectra are calculated and the structural parameters of FMN dimer are established. Excitation wavelength and temperature dependencies of FMN/PVA fluorescence spectra for different FMN concentrations were carried out. These measurements together with those of absorption reveal that dimers are imperfect traps for excitation energy and that the energy transfer can occur both in forward and in reverse direction. Moreover, it was shown that the observed temperature changes in fluorescence spectra may be qualitatively explained by the effect of inhomogeneous broadening of FMN energy levels and by the presence of fluorescent dimers.

Environmental risk factors of cancer and their primary prevention.

The evaluation of the influence of different environmental carcinogenic factors requires interdisciplinary cooperation. Related studies include epidemiological surveys and air, water and soil, chemical, toxicological, and microbiological analyses, supplemented by experimental verification of suspected ecological pathogens and cofactors. A balance of carcinogens and protective agents in the external environment and in the human body is recommended for an ecologically oriented prevention. Toxicological control of the food chain using modern technology (Proton-induced X-ray emission (PIXE), nuclear activation analysis, and induced coupled plasma) should be integrated with microanalyses at the cellular level (by X-ray scanning electron microscopy, nuclear magnetic response, PIXE, and spontaneous and delayed chemiluminescence for balance of free-radicals and their scavengers). A pilot cross-disciplinary study conducted in the area of a "cluster" of human neoplasms and cattle leukemia, in comparison with control villages in Poland, showed an excess in Pb, Hg, Ni, Rb, K, Mn, Cr, and Zn, accompanied by a nutritional deficiency in Mg, Ca, Fe, Co, and Se in the food chain of the "cluster." The living and breeding houses in this area were significantly more contaminated with the toxicogenic molds Aspergillus flavus and Penicillium meleagrinum and by nitrate and nitrite in the drinking water. Our experiments showed that selenium deficiency stimulated the growth of fungi and some bacteria and increased the immunosuppressive and teratogenic effects of aflatoxin B1. New methods of protection of the indoor environment against microbiological contamination and laser-related biotechnology for nutritional prevention of selenium deficiency and associated risk of neoplasms have been introduced. Primary prevention requires a large scale application of highly sensitive methods for early detection of risk factors in the environment, food, water, and at the personal level, as well as education of the society and an integrated common corrective action.

Effect of dicumarol on the growth of some soil microorganisms.

The effect of dicumarol on growth of selected soil bacteria: Azotobacter chroococcum, Arthrobacter globiformis, A. citreus and Bacillus megaterium was studied. The following minimum concentrations were inhibitory in vitro: Arthrobacter citreus--20 mug/ml., Bacillus megaterium--40 mug/ml., Azotobacter chroococcum--40 mug/ml. Arthrobacter globiformis--70 mug/ml. Cells of all microorganisms studied grown in the presence of dicumarol developed aberrant morphological forms.

Selenium effect on the growth of carcinogenic fungi and cytotoxic action of aflatoxin B1 on lymphocyte culture and on embryonal development of Xenopus laevis.

The authors report the results of investigations on the protective effect of selenium against teratogenic and cytotoxic action of aflatoxin B1 and the inhibitory action of this element on the growth of fungi producing carcinogenic aflatoxins. Sodium selenate inhibited the growth of cultures of such fungi belonging to the class Fungi imperfecti as Aspergillus flavus, Aspergillus fumigatus, Penicillium meleagrinum and Penicillium rougolosum. Added to cell cultures of lymphocytes sodium selenate inhibited the cytotoxic action of aflatoxin B1 evidenced by inhibition of PHA-stimulated blastic transformation of these cells and reduction in the number of mitoses. Sodium selenate added to the medium in the culture of Xenopus laevis larvae poisoned with aflatoxin B1 reduced significantly the early mortality of embryos and counteracted the teratogenic action of aflatoxin B1. This action was observed, however, only in early phase of morulation. The authors discuss the importance of their observations for the studies on the role of bioelements deficiency in the environment for induction of malignant transformation.