Observational Constraints on Potassium Synthesis during the Formation of Stars of the Galactic Disk

The non-LTE potassium abundances in the atmospheres of 33 Galactic-disk stars are derived and the parameters of the atmospheres of 23 of the stars are determined. Neglecting departures from LTE results in a systematic overestimation of the potassium abundances and an increase in their dispersion, even for differential analyses relative to the Sun. The non-LTE corrections are significant ((-0.2)-(-0.6) dex) and depend on the surface gravities and effective temperatures of the stars. The mean potassium abundance for a sample of ten stars with [Fe/H] ∼ 0.0 is in agreement with the solar and meteoritic abundances (log ε ⊙ (K) = 5.12). As the stellar metallicity increases from [Fe/H] = (-1.0) to (0.2) dex, the [K/Fe] ratio decreases systematically from 0.3 dex to -0.1 dex. The derived dependence [K/Fe]-[Fe/H] is in agreement with the results of published model calculations of the chemical evolution of the Galaxy. This indicates the dominance of explosive oxygen burning in massive type II supernovae during the synthesis of potassium in the Galactic disk. © 2003 MAIK "Nauka/Interperiodica"

A Compiled Catalogue of Spectroscopically Determined Elemental Abundances for Stars with Accurate Parallaxes. I.Magnesium

We present a compiled catalogue of effective temperatures, surface gravities, iron and magnesium abundances, distances, velocity components, and orbital elements for stars in the solar neighborhood. The atmospheric parameters and iron abundances are averages of published values derived from model synthetic spectra for a total of about 2000 values in 80 publications. Our relative magnesium abundances were found from 1412 values in 31 publications for 876 dwarfs and subgiants using a three-step iteration averaging procedure, with weights assigned to each source of data as well as to each individual determination and taking into account systematic deviations of each scale relative to the reduced mean scale. The estimated assumed completeness for data sources containing more than five stars, up to late December 2003, exceeds 90%. For the vast majority of stars in the catalogue, the spatial velocity components were derived from modern high-precision astrometric observations, and their Galactic orbit elements were computed using a three-component model of the Galaxy, consisting of a disk, a bulge, and a massive extended halo.Comment: Accepted for Astron. Rep. 2005, v.49, No.5, p.405-416, 12 pages, 10 figure

Ising Universality in Three Dimensions: A Monte Carlo Study

We investigate three Ising models on the simple cubic lattice by means of Monte Carlo methods and finite-size scaling. These models are the spin-1/2 Ising model with nearest-neighbor interactions, a spin-1/2 model with nearest-neighbor and third-neighbor interactions, and a spin-1 model with nearest-neighbor interactions. The results are in accurate agreement with the hypothesis of universality. Analysis of the finite-size scaling behavior reveals corrections beyond those caused by the leading irrelevant scaling field. We find that the correction-to-scaling amplitudes are strongly dependent on the introduction of further-neighbor interactions or a third spin state. In a spin-1 Ising model, these corrections appear to be very small. This is very helpful for the determination of the universal constants of the Ising model. The renormalization exponents of the Ising model are determined as y_t = 1.587 (2), y_h = 2.4815 (15) and y_i = -0.82 (6). The universal ratio Q = ^2/ is equal to 0.6233 (4) for periodic systems with cubic symmetry. The critical point of the nearest-neighbor spin-1/2 model is K_c=0.2216546 (10).Comment: 25 pages, uuencoded compressed PostScript file (to appear in Journal of Physics A

PDCD4 and CDX-2 as immunohistochemical markers of gastric mucosa atrophy in chronic gastritis

The aim of the work is to evaluate the possibility of using immunohistochemical markers PDCD4 and CDX-2 to diagnose atrophy of the gastric mucosa in chronic gastritis and increase the informative value of biopsy examination.Цель работы – оценка возможности использования иммуногистохимических маркеров PDCD4 и CDX-2 для диагностики атрофии слизистой оболочки желудка при хроническом гастрите, повышения информативности биопсийного исследования

Evaluation of the CDX2 protein distribution in the gastric mucosa in chronic gastritis by a semi-quantitative index and its reproducibility

The purpose of the study was to assess the reproducibility of the semi-quantitative CDX2 index calculation in chronic atrophic gastritis stages I-IV.Цель исследования – оценка воспроизводимости методики расчета полуколичественного индекса CDX2 при I-IV стадиях хронического атрофического гастрита

Formation of Galactic Systems in Light of the Magnesium Abundance in Field Stars: The Thick Disk

The space velocities and Galactic orbital elements of stars calculated from the currently available high-accuracy observations in our summary catalog of spectroscopic magnesium abundances in dwarfs and subgiants in the solar neighborhood are used to identify thick-disk objects. The relative magnesium abundances in thick-disk stars are shown to lie within the range 0.0<[Mg/Fe]<0.5 and to decrease with increasing metallicity starting from [Fe/H]=-1.0. This is interpreted as evidence for a longer duration of the star formation process in the thick disk. We have found vertical gradients in metallicity (grad_Z[Fe/H]=-0.13\pm 0.04 kpc^{-1}) and relative magnesium abundance (grad_Z [Mg/Fe]=0.06\pm 0.02 kpc^{-1}), which can be present in the subsystem only in the case of its formation in a slowly collapsing protogalaxy. The large spread in relative magnesium abundance (-0.3<[Mg/Fe]<0.5) in the stars of the metal-poor "tail" of the thick disk which constitute 8% of the subsystem, can be explained in terms of their formation inside isolated interstellar clouds that interacted weakly with the matter of a single protogalactic cloud. We have found a statistically significant negative radial gradient in relative magnesium abundance in the thick disk (grad_R [Mg/Fe]=-0.03\pm 0.01 kpc^{-1}) instead of the expected positive gradient. The smaller perigalactic orbital radii and the higher eccentricities for magnesium-richer stars, which among other stars, are currently located in a small volume of the Galactic space near the Sun are assumed to be responsible for the gradient inversion. A similar but statistically less significant inversion is also observed in the subsystem for the radial metallicity gradient.Comment: Accepted for 2005, Astronomy Letters, Vol. 31, No. 8, P.515-527; 14 pages, 6 figure

Consensus as a method for evaluating the reproducibility of gastric intraepithelial neoplasia/dysplasia: possibility of using in the process of continuing professional education of pathologists

The reproducibility of the Modified Vienna classification of gastrointestinal neoplasia on the gastric mucosal biopsies was evaluated by using the kappa statistic. The work of a group of pathologists-experts was organized in the remote access mode with a demonstration of 26 cases (98 microphotographs) and an evaluation of the diagnostic category of gastric intraepithelial neoplasia/dysplasia. Different levels of agreement between the opinions of the participating experts have been established in depending on the diagnostic difficulty level. The kappa level ranged from 0.2 (poor agreement) to 0.66 (good agreement) and was depending from the chosen method of correction of the result. , This circumstance contributed to the formation of opinion that the diagnoses indefinite neoplasia/dysplasia-low and high grade neoplasia/dysplasia were the most difficult decisions. Possible reasons which reduce the level of consistency of pathologists are discussed.Методами каппа-статистики проведена оценка воспроизводимости Модифицированной Венской классификации неоплазий пищеварительного тракта на материале биопсий слизистой оболочки желудка. В дистанционном режиме организована работа группы патологоанатомов-экспертов с демонстрацией 26 наблюдений (98 фотографий) с оценкой диагностической категории интраэпителиальной неоплазии/дисплазии слизистой оболочки желудка. Установлены различные уровни совпадения мнения участвовавших экспертов в зависимости от сложности диагностической задачи. Уровень каппа колебался от 0,2 (плохое согласие) до 0,66 (хорошее согласие) в зависимости от выбранного метода коррекции результата, что способствовало формированию мнения о наиболее сложных с точки зрения согласованного мнения диагностических категориях, находящихся в ряду неопределенная неоплазия/ дисплазия – неоплазия/дисплазия низкой и высокой степени. обсуждаются возможные причины, снижающие уровень согласованности патологоанатомов-экспертов

Molecular and cellular basis in prediction of gastric cancer: a multidisciplinary research experience

A self-review of the results of multidisciplinary studies on the development of a predictive system for intestinal type gastric cancer (adenocarcinoma) is present. The authors' studies carried out in 2007-2017 in light of recent concepts of prediction and prevention of gastric cancer are discussed. The predictive model for gastric cancer is proposed. This includes an evaluation of inflammatory cytokine genes nucleotide polymorphisms, aberrant expression of microRNA, detection of tissue patterns of gastric atrophy and intestinal metaplasia (metaplastic atrophy), principles and possibilities of pathomorphological monitoring.Представлен самообзор результатов мультидисциплинарных исследований по разработке предиктивной системы в отношении рака желудка кишечного типа (аденокарциномы). Обсуждаются исследования авторов, выполненные в 2007-2017 годах в аспекте современных концепций предикции и превенции рака желудка. Предложена модель предикции рака желудка, включающая оценку нуклеотидных замен в генах воспалительных цитокинов, аберрантную экспрессию микроРНК, детекцию тканевых паттернов атрофии и метапластической атрофии слизистой оболочки желудка, принципы и возможности патоморфологического мониторинга

COMPLEX ANALYSIS OF CLINICAL-MORPHOLOGICAL AND MOLECULAR GENETIC MARKERS IN PATIENTS WITH CHRONIC DERMATOSIS ASSOCIATED WITH FACIAL SKIN ATROPHY

Background. The ralationship between skin structural alterations and activity variations of genes controlling collagen and elastin synthesis in patients with chronic dermatosis associated with facial skin atrophy is not well known. Objective. To clarify associations between clinical-morphological and molecular genetic markers in skin biopsy samples by using complex analysis. Material and methods. Skin punch-biopsies with the diameter from 1 to 4 mm were used as research material. Histological analysis was carried out for morphological features estimation; real-time PCR with reverse transcription was performed for evaluation of the gene expression level. Results. Morphological alterations in the skin of patients with chronic dermatosis are associated with the level of normalized expression of genes: gene СOL1A1 less than 100% and/or gene COL1A2 less than 200% and/or gene LOX less than 50%. Conclusions. Real-time PCR with reverse transcription can be used for objective estimation of the degree of skin alterations in patients with chronic dermatosis

Neuroendocrine Tumour as a Diagnostic and Prognostic Criterion for Autoimmune Gastritis

Aim. To describe modern approaches to the diagnosis and treatment of neuroendocrine gastric tumours associated with chronic autoimmune gastritis on the example of a clinical case.General provisions. Patient H., born in 1948, suffered from a dyspepsia syndrome, the presence of chronic exhelicobacter gastritis and neuroendocrine tumour of unclear histogenesis in the upper third of the stomach body. The patient also suffered from systemic lupus erythematosus with skin lesions (discoid rash, palmar and plantar capillaries) and joint lesions (migrating polyarthritis). A general clinical examination revealed mild chronic iron deficiency anemia and increased neuron-specific enolase (NSE). An EGDS examination using expert-class equipment with the NBI function of close focus identified subepithelial formations of the stomach body. The histological results showed a morphological pattern consistent with a highly differentiated neuroendocrine tumour (G1), type 1, associated with chronic autoimmune gastritis.Conclusion. The autoimmune genesis of the chronic inflammation of the gastric mucosa may serve as a background for the development of neuroendocrine tumours of the stomach, which determines the management tactics in such conditions