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81.
Kopecky KJ Stepanenko V Rivkind N Voillequé P Onstad L Shakhtarin V Parshkov E Kulikov S Lushnikov E Abrosimov A Troshin V Romanova G Doroschenko V Proshin A Tsyb A Davis S 《Radiation research》2006,166(2):367-374
A population-based case-control study was conducted to estimate the radiation-related risk of thyroid cancer in persons who were exposed in childhood to (131)I from the Chernobyl accident of April 26, 1986 and to investigate the impact of uncertainties in individual dose estimates. Included were all 66 confirmed cases of primary thyroid cancer diagnosed from April 26, 1986 through September 1998 in residents of Bryansk Oblast, Russia, who were 0-19 years old at the time of the accident, along with two individually matched controls for each case. Thyroid radiation doses, estimated using a semi-empirical model based on environmental contamination data and individual characteristics, ranged from 0.00014 Gy to 2.73 Gy and had large uncertainties (median geometric standard deviation 2.2). The estimated excess relative risk (ERR) associated with radiation exposure, 48.7/Gy, was significantly greater than 0 (P = 0.00013) but had an extremely wide 95% confidence interval (4.8 to 1151/Gy). Adjusting for dose uncertainty nearly tripled the ERR to 138/Gy, although this was likely an overestimate due to limitations in the modeling of dose uncertainties. The radiation-related excess risk observed in this study is quite large, especially if the uncertainty of dose estimation is taken into account, but is not inconsistent with estimates previously reported for risk after (131)I exposure or acute irradiation from external sources. 相似文献
82.
Marina A. Katkova Georgy K. Fukin Anatoly S. Averyushkin Mikhail N. Bochkarev 《Inorganica chimica acta》2006,359(13):4289-4296
The thiolate complexes of rare earth metals Ln(SR)3 (La, HSR = 2-mercaptothiazoline (1); La, HSR = 2-mercaptobenzoxazole (2); Y, La, Sm, Eu, Tb, Gd, Er, Tm, HSR = 2-mercaptobenzothiazole (3)) were synthesized in 84-97% yield by the reactions of silylamides Ln[N(SiMe3)2]3 with respective thiols. The products were characterized by elemental analysis, IR and UV/Vis spectroscopy. The structures of 3(Eu) and 3(Er) were determined by single-crystal X-ray diffraction. All obtained compounds revealed efficient luminescence in the region 400-550 nm at 293 K assigned to the ligands emission. Besides, the luminescent spectra of thiolates 3 at 77 K displayed the phosphorescent band of the ligand at 550 nm and in the cases of 3(Eu) and 3(Tb) the sets of emissions bands characteristic for Eu3+ and Tb3+ ions. 相似文献
83.
Sorokin AA Osypov AA Dzhelyadin TR Beskaravainy PM Kamzolova SG 《Journal of bioinformatics and computational biology》2006,4(2):455-467
A comparative analysis of electrostatic patterns for 359 sigma70-specific promoters and 359 nonpromoter regions on electrostatic map of Escherichia coli genome was carried out. It was found that DNA is not a uniformly charged molecule. There are some local inhomogeneities in its electrostatic profile which correlate with promoter sequences. Electrostatic patterns of promoter DNAs can be specified due to the presence of some distinctive motifs which differ for different promoter groups and may be involved as signal elements in differential recognition of various promoters by the enzyme. Some specific electrostatic elements which are responsible for modulating promoter activities due to ADP-ribosylation of RNA polymerase alpha-subunit were found in far upstream regions of T4 phage early promoters and E. coli ribosomal promoters. 相似文献
84.
Anatoly Peretyatko Samuel Teissier Sylvia De Backer Ludwig Triest 《Hydrobiologia》2012,689(1):131-146
Nutrient enrichment of aquatic ecosystems caused dramatic increase in the frequency, magnitude and duration of cyanobacterial
blooms. Such blooms may cause fish kills, have adverse health effects on humans and contribute to the loss of biodiversity
in aquatic ecosystems. Some 50 eutrophic to hypereutrophic ponds from the Brussels Capital Region (Belgium) were studied between
2003 and 2009. A number of the ponds studied are prone to persistent cyanobacterial blooms. Because of the related health
concerns and adverse effects on ecological quality of the affected ponds, a tool for assessment of the risk of cyanobacterial
bloom occurrence was needed. The data acquired showed that cyanobacteria have threshold relationships with most of the environmental
factors that control them. This is negatively reflected on the predictive capacity of conventional statistical methods based
on linear relationships. Therefore, classification trees designed for the treatment of complex data and non-linear relationships
were used to assess the risk of cyanobacterial bloom occurrence. The main factors determining cyanobacterial bloom development
appeared to be phytoplankton biomass, pH and, to a lesser degree, nitrogen availability. These results suggest that to outcompete
eukaryotic phytoplankters cyanobacteria need the presence of environmental constraints: carbon limitation, light limitation
and nitrogen limitation, for which they developed a number of adaptations. In the absence of constraints, eukaryotic phytoplankters
appear to be more competitive. Therefore, prior build up of phytoplankton biomass seems to be essential for cyanobacterial
dominance. Classification trees proved to be an efficient tool for the bloom risk assessment and allowed the main factors
controlling bloom development to be identified as well as the risk of bloom occurrence corresponding to the conditions determined
by these factors to be quantified. The results produced by the classification trees are consistent with those obtained earlier
by probabilistic approach to bloom risk assessment. They can facilitate planning management interventions and setting restoration
priorities. 相似文献
85.
Akushevich I Veremeyeva G Kravchenko J Ukraintseva S Arbeev K Akleyev AV Yashin AI 《Mathematical biosciences》2012,236(1):16-30
In this paper we present a new multiple-pathway stochastic model of carcinogenesis with potential of predicting individual incidence risks on the basis of biomedical measurements. The model incorporates the concept of intracellular barrier mechanisms in which cell malignization occurs due to an inefficient operation of barrier cell mechanisms, such as antioxidant defense, repair systems, and apoptosis. Mathematical formalism combines methodological innovations of mechanistic carcinogenesis models and stochastic process models widely used in studying biodemography of aging and longevity. An advantage of the modeling approach is in the natural combining of two types of measures expressed in terms of model parameters: age-specific hazard rate and means of barrier states. Results of simulation studies allow us to conclude that the model parameters can be estimated in joint analyses of epidemiological data and newly collected data on individual biomolecular measurements of barrier states. Respective experimental designs for such measurements are suggested and discussed. An analytical solution is obtained for the simplest design when only age-specific incidence rates are observed. Detailed comparison with TSCE model reveals advantages of the approach such as the possibility to describe decline in risk at advanced ages, possibilities to describe heterogeneous system of intermediate cells, and perspectives for individual prognoses of cancer risks. Application of the results to fit the SEER data on cancer risks demonstrates a strong predictive power of the model. Further generalizations of the model, opportunities to measure barrier systems, biomedical and mathematical aspects of the new model are discussed. 相似文献
86.
Timothy Andrew Kelf Martin Gosnell Bjornar Sandnes Anna E. Guller Anatoly B. Shekhter Andrei V. Zvyagin 《Journal of biophotonics》2012,5(2):159-167
This paper addresses the scar tissue maturation process that occurs stepwise, and calls for reliable classification. The structure of collagen imaged by nonlinear optical microscopy (NLOM) in post‐burn hypertrophic and mature scar, as well as in normal skin, appeared to distinguish these maturation steps. However, it was a discrimination analysis, demonstrated here, that automated and quantified the scar tissue maturation process. The achieved scar classification accuracy was as high as 96%. The combination of NLOM and discrimination analysis is believed to be instrumental in gaining insight into the scar formation, for express diagnosis of scar and surgery planning. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
87.
Bruskov VI Karp OE Garmash SA Shtarkman IN Chernikov AV Gudkov SV 《Free radical research》2012,46(10):1280-1290
Abstract The formation of long-lived reactive protein species of bovine serum albumin (BSA), ovalbumin, casein and casein hydrolyzate with a half-life of 3-5 hours was shown using chemiluminescence induced by X-ray radiation. It was found that long-lived reactive protein species are capable of generating reactive oxygen species (ROS) (H(2)O(2), OH(?), HO(2)(?, 1)O(2)) in the aquatic environment over a long period of time in vitro. The interaction of X-ray-irradiated BSA with DNA in vitro led to the formation of 8-oxoguanine (8-oxo-7,8-dihydroguanine), a biomarker of oxidative damage to DNA. Some natural antioxidants are effective scavengers of ROS (inosine, tryptophan, methionine and ascorbate). They protect DNA from the action of long-lived reactive protein species leading to ROS generation and the formation of 8-oxoguanine. The intravenous injection of X-ray radiation-induced, long-lived reactive protein species to rats, as well as the peroral and intraperitoneal administration of these products to mice, gave rise to cytogenetic injuries in the cells of their red bone marrow through the formation of micronuclei in polychromatophilic erythrocytes. The administration of the same natural antioxidants used for in vitro experiments soon after irradiation made it possible to effectively eliminate the genotoxic action of oxidative stress caused by radiation-induced, long-lived reactive protein species. Our data represent clear evidence that the oxidative damage to proteins induced by X-rays is directly involved in the induction of a response to DNA damage in rodents. 相似文献
88.
Demirkan A van Duijn CM Ugocsai P Isaacs A Pramstaller PP Liebisch G Wilson JF Johansson Å Rudan I Aulchenko YS Kirichenko AV Janssens AC Jansen RC Gnewuch C Domingues FS Pattaro C Wild SH Jonasson I Polasek O Zorkoltseva IV Hofman A Karssen LC Struchalin M Floyd J Igl W Biloglav Z Broer L Pfeufer A Pichler I Campbell S Zaboli G Kolcic I Rivadeneira F Huffman J Hastie ND Uitterlinden A Franke L Franklin CS Vitart V;DIAGRAM Consortium Nelson CP Preuss M;CARDIoGRAM Consortium Bis JC O'Donnell CJ 《PLoS genetics》2012,8(2):e1002490
Phospho- and sphingolipids are crucial cellular and intracellular compounds. These lipids are required for active transport, a number of enzymatic processes, membrane formation, and cell signalling. Disruption of their metabolism leads to several diseases, with diverse neurological, psychiatric, and metabolic consequences. A large number of phospholipid and sphingolipid species can be detected and measured in human plasma. We conducted a meta-analysis of five European family-based genome-wide association studies (N = 4034) on plasma levels of 24 sphingomyelins (SPM), 9 ceramides (CER), 57 phosphatidylcholines (PC), 20 lysophosphatidylcholines (LPC), 27 phosphatidylethanolamines (PE), and 16 PE-based plasmalogens (PLPE), as well as their proportions in each major class. This effort yielded 25 genome-wide significant loci for phospholipids (smallest P-value = 9.88×10−204) and 10 loci for sphingolipids (smallest P-value = 3.10×10−57). After a correction for multiple comparisons (P-value<2.2×10−9), we observed four novel loci significantly associated with phospholipids (PAQR9, AGPAT1, PKD2L1, PDXDC1) and two with sphingolipids (PLD2 and APOE) explaining up to 3.1% of the variance. Further analysis of the top findings with respect to within class molar proportions uncovered three additional loci for phospholipids (PNLIPRP2, PCDH20, and ABDH3) suggesting their involvement in either fatty acid elongation/saturation processes or fatty acid specific turnover mechanisms. Among those, 14 loci (KCNH7, AGPAT1, PNLIPRP2, SYT9, FADS1-2-3, DLG2, APOA1, ELOVL2, CDK17, LIPC, PDXDC1, PLD2, LASS4, and APOE) mapped into the glycerophospholipid and 12 loci (ILKAP, ITGA9, AGPAT1, FADS1-2-3, APOA1, PCDH20, LIPC, PDXDC1, SGPP1, APOE, LASS4, and PLD2) to the sphingolipid pathways. In large meta-analyses, associations between FADS1-2-3 and carotid intima media thickness, AGPAT1 and type 2 diabetes, and APOA1 and coronary artery disease were observed. In conclusion, our study identified nine novel phospho- and sphingolipid loci, substantially increasing our knowledge of the genetic basis for these traits. 相似文献
89.
Anatoly S. Karavaev Anatoly S. Borovik Ekaterina I. Borovkova Eugeniya A. Orlova Margarita A. Simonyan Vladimir I. Ponomarenko Viktoriia V. Skazkina Vladimir I. Gridnev Boris P. Bezruchko Mikhail D. Prokhorov Anton R. Kiselev 《Biophysical journal》2021,120(13):2657-2664
The question of how much information the photoplethysmogram (PPG) signal contains on the autonomic regulation of blood pressure (BP) remains unsolved. This study aims to compare the low-frequency (LF) and high-frequency components of PPG and BP and assess their correlation with oscillations in interbeat (RR) intervals at similar frequencies. The PPG signal from the distal phalanx of the right index finger recorded using a reflective PPG sensor at green light, the BP signal from the left hand recorded using a Finometer, and RR intervals were analyzed. These signals were simultaneously recorded within 15 min in a supine resting condition in 17 healthy subjects (12 males and 5 females) aged 33 ± 9 years (mean ± SD). The study revealed the high coherence of LF components of PPG and BP with the LF component of RR intervals. The high-frequency components of these signals had low coherence. The analysis of the signal instantaneous phases revealed the presence of high-phase coherence between the LF components of PPG and BP. It is shown that the LF component of PPG is determined not only by local myogenic activity but also reflects the processes of autonomic control of BP. 相似文献
90.
Selective ‘stencil’-aided pre-PCR cleavage of wild-type sequences as a novel approach to detection of mutant K-RAS 下载免费PDF全文
Anatoly V. Lichtenstein Olga I. Serdjuk Tatjana I. Sukhova Hovsep S. Melkonyan Samuil R. Umansky 《Nucleic acids research》2001,29(17):e90
The enriched PCR widely used for detection of mutant K-RAS in either tumor tissues or circulating DNA was modified so that abundant wild-type K-RAS alleles are cleaved prior to PCR. We took advantage of an AluI recognition site located immediately upstream of the K-RAS codon 12. The site was reconstituted upon DNA denaturation followed by annealing with a ‘stencil’, a 16-bp synthetic oligonucleotide complementary to the wild-type sequence. As opposed to normal K-RAS, the mutant allele forms, upon annealing with the stencil, a mismatch at the codon 12 which lies within the AluI enzyme binding site and partially inhibits its activity. The mismatch also lowers the melting temperature of the stencil-mutant K-RAS double helix as compared to stencil–wild-type duplex, so that only the latter is double stranded and selectively digested by AluI at elevated temperatures. The proposed method of stencil-aided mutation analysis (SAMA) based on selective pre-PCR elimination of wild-type sequences can be highly advantageous for detection of mutant K-RAS due to: (i) an enhanced sensitivity because of reduced competition with a great excess of normal K-RAS, and (ii) a decrease in a number of false-positive results from Taq polymerase errors. Application of SAMA for generalized detection of DNA mutations is discussed. 相似文献