An imbalance between the phases of biotransformation systems, such as activation, detoxification, and release of toxic substances, is one of the causes of multifactor pathology. Therefore, it is ...important to examine the impact of the total contribution of the polymorphic variants of xenobiotic-metabolizing enzyme genes at all three phases on predisposition to lung cancer. The purposes of the present work were to study the relationship between polymorphic variants of xenobiotic-metabolizing enzyme genes and risk of lung cancer and to identify molecular genetic markers of predisposition to the disease. It was shown that GSTT1 null-genotype plays a dominant role in the development of lung cancer predisposition in the Belarusian population, while the polymorphic variants of other genes of xenobiotic-metabolizing enzymes render a modifying effect on predisposition to this disease. Combination 734AA CYP1A2/GSTT1(−)/GSTM1(+)/“slow” acetylator has the greatest risk significance, and combination GSTT1(−)/GSTM1(+)/“slow” acetylator exerts a protective effect.
Imbalance between the phases of the biotransfotmation system (activation, detoxication and removal of toxic compounds) is one of the causes of multifactorial pathology developing. That is why study ...on the influence of the total contribution of polymorphic gene variants of xenobiotic biotransformation enzymes of all three phases on predisposition to lung cancer emergence is important. The aim of the work was to determine polymorphic variants of genes of xenobiotic biotransformation enzymes of lung cancer patients and to identify markers of predisposition to lung cancer. Association of homozygous GSTT1 gene deletion with predisposition to lung cancer was detected in residents of Belarus. Combinations of polymorphic gene loci of biotransformation enzymes exert a modifying effect on risk importance of GSTT1 genotype in lung cancer development. The combination 734AA CYP1A2/GSTT1(-)/GSTM1(+)/"slow" acetylator/3435CC MDR1 is of the highest risk importance. The combination "slow" acetylator/GSTT1(+)/ GSTM1(+) exerts a protective effect.
Black carbon (BC), emitted by fossil fuel combustion and biomass burning, is the second largest man-made contributor to global warming after carbon dioxide (Bond et al., 2013). However, limited ...information exists on its past emissions and atmospheric variability. In this study, we present the first high-resolution record of refractory BC (rBC, including mass concentration and size) reconstructed from ice cores drilled at a high-altitude eastern European site in Mt. Elbrus (ELB), Caucasus (5115 m a.s.l.). The ELB ice core record, covering the period 1825–2013, reflects the atmospheric load of rBC particles at the ELB site transported from the European continent with a larger rBC input from sources located in the eastern part of Europe. In the first half of the 20th century, European anthropogenic emissions resulted in a 1.5-fold increase in the ice core rBC mass concentrations with respect to its level in the preindustrial era (before 1850). The summer (winter) rBC mass concentrations increased 5-fold (3.3-fold) in 1960–1980, followed by a decrease until ∼ 2000. Over the last decade, the rBC signal for summertime slightly increased. We have compared the signal with the atmospheric BC load simulated using past BC emissions (ACCMIP and MACCity inventories) and taken into account the contribution of different geographical regions to rBC distribution and deposition at the ELB site. Interestingly, the observed rBC variability in the ELB ice core record since the 1960s is not in perfect agreement with the simulated atmospheric BC load. Similar features between the ice core rBC record and the best scenarios for the atmospheric BC load support anthropogenic BC increase in the 20th century being reflected in the ELB ice core record. However, the peak in BC mass concentration observed in ∼ 1970 in the ice core is estimated to occur a decade later from past inventories. BC emission inventories for the period 1960s–1970s may be underestimating European anthropogenic emissions. Furthermore, for summertime snow layers of the 2000s, the slightly increasing trend of rBC deposition likely reflects recent changes in anthropogenic and biomass burning BC emissions in the eastern part of Europe. Our study highlights that the past changes in BC emissions of eastern Europe need to be considered in assessing ongoing air quality regulation.
Kinetics of hydrogen adsorption and desorption for palladium- 7% yttrium foil was studied using volume metrics measurements in oil free vacuum cell. Preliminary H2 was purified by diffusion from ...Pd-Ru membrane. Plots of the rate and constant rate of H2 adsorption/desorption versus temperature in interval 333-573 K were obtained. It was found that H2 sorption is the thermal activated process. The values of amount of H2 adsorbed, rate Ws, constant rate Ks and activation energy of sorption Ea,s of H2 sorption differs for initial foil surface and surface with preadsorbed hydrogen, which inhibits the repeated sorption. Due to preadsorbed hydrogen Ks decreases in 1,5 times (333 K) and Ea,s for molecular form of hydrogen adsorption increases in two times. Kinetics characteristics of hydrogen desorption depend on duration of the expose PdY foil in H2 at room temperature. Long saturation leads to sharply decrease of the hydrogen desorption rate and to some increase of activation energy of desorption varying from 56-68 and 85-108 kJ/mol for first and second kinetic order respectively. Isotherms of hydrogen adsorption were of anomalous shape and can be explained by the induced adsorption model. The results of isotherms analysis agree with kinetic data.
Objective. Analysis of a clinical picture and functional dysfunctions with ADRB2 gene molymorphism in patients with PHCM. Materials and methods. 89 patients with PHCM were included in the study (69 ...males and 20 females, mean age 46,7±15,7), among which 56 had been diagnosed with the obstructive form, 33 patients had a non-obstructive form of the disease. The control set included 104 healthy donors adequate in age, and gender with PHCM. The clinical picture of the disease was assessed, echocardiographic indicators and daily ECG monitoring parameters were specified. The ADRB2 gene polymorphism analysis was made in all patients. Results. The association of the clinical picture, structural and functional LV myocardial peculiarities with ADRB2 gene polymorphism in patients with PHCM. It was revealed that the combination of Arg16rg/Gln27Gln genotypes is a risk genotype and is associated with the appearance of adverse clinical manifestations of the disease. The combination of Gly16Gly/Glu27Glu genotypes is protective and is Conclusion. The results obtained have revealed the association of the ADRB2 gene polymorphism with clinical, structural and functional dysfunctions in patients with PHCM which will allow making prognoses of adverse clinical manifestations risk and improving β-adrenoblocker treatment of PHCM patients.
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