1,227 research outputs found
Роль генетического компонента предрасположенности к раку молочной железы у женщин различных этнических групп населения Крыма
Результаты клинико-генеалогического и генетико-математического методов исследования 57 здоровых и 214 больных раком молочной железы (РМЖ) женщин показали, что частота заболевания злокачественными новообразованиями родственников I степени родства пациентов с РМЖ как крымско-татарской, так и славянских этнических групп более высокая (10,44%), чем в крымской популяции в целом (7,36%). Возникновение РМЖ у женщин крымско-татарской этнической группы в большей мере обусловлено генетической предрасположенностью к злокачественному росту по сравнению со славянской группой, о чем свидетельствуют появления РМЖ в более молодом возрасте как у пробандов-татарок, так и их родственниц (53,4 ± 3,6 и 46,5 ± 11,2 года соответственно в сравнении с 59,8 ± 1,9 и 54,9 ± 8,3 года у славянок), более частое развитие РМЖ у родственниц татарок (48,3 ± 11,1 против 25,6 ± 6,6%), более высокая соотносительная доля наследственных факторов в возникновении рака (генетический компонент 58,5 против 44,5%, р 0,05). Ключевые слова: этнические особенности, злокачественные новообразования, рак молочной железы, наследственность.A clinical/genealogical and genetic mathematic study of 57 healthy subjects and 214 breast cancer (BC) patients showed that malignant neoplasm is more frequent in immediate (degree 1) relatives of BC patients in both Crimean Tartar and Slavic populations compared to the general population (10.44% versus 7.36% respectively). In the Crimean Tartar population, genetic burden plays a more considerable role in BC frequency compared to the Slavic population. This conclusion is based on a number of findings, including: younger age of BC manifestation in both probands and their relatives (53.4 ± 3.6 and 46.5 ± 11.2 in Tartars versus 59.8 ± 1.9 and 54.9 ± 8.3 in Slavs), higher frequency of BC in relatives (48.3 ± 11.1 versus 25.6 ± 6.6% respectively), higher correlative share of genetic factors in the development of malignancy (genetic component: 58.5 against 44.5%, р 0.05). Key Words: ethnic specifics, malignancy, breast cancer, hereditation
The changing paradigm of intron retention: regulation, ramifications and recipes
Intron retention (IR) is a form of alternative splicing that has long been neglected in mammalian systems although it has been studied for decades in non-mammalian species such as plants, fungi, insects and viruses. It was generally assumed that mis-splicing, leading to the retention of introns, would have no physiological consequence other than reducing gene expression by nonsense-mediated decay. Relatively recent landmark discoveries have highlighted the pivotal role that IR serves in normal and disease-related human biology. Significant technical hurdles have been overcome, thereby enabling the robust detection and quantification of IR. Still, relatively little is known about the cis- and trans-acting modulators controlling this phenomenon. The fate of an intron to be, or not to be, retained in the mature transcript is the direct result of the influence exerted by numerous intrinsic and extrinsic factors at multiple levels of regulation. These factors have altered current biological paradigms and provided unexpected insights into the transcriptional landscape. In this review, we discuss the regulators of IR and methods to identify them. Our focus is primarily on mammals, however, we broaden the scope to non-mammalian organisms in which IR has been shown to be biologically relevant
The detection of single electrons by means of a Micromegas-covered MediPix2 pixel CMOS readout circuit
A small drift chamber was read out by means of a MediPix2 readout chip as
direct anode. A Micromegas foil was placed 50 m above the chip, and
electron multiplication occurred in the gap. With a He/Isobutane 80/20 mixture,
gas multiplication factors up to tens of thousands were achieved, resulting in
an efficiency for detecting single electrons of better than 90% . We recorded
many frames containing 2D images with tracks from cosmic muons. Along these
tracks, electron clusters were observed, as well as delta-rays.Comment: 15 pages, 9 included postscript figures, 5 separate jpeg figures,
submitted to Nucl. Instr. and Meth. A. A complete postscript version with
high resolution figures 1, 3, 11, 12 and 14 can be found at
http://www.nikhef.nl/~i06/RandD/final/letter4.p
Ctcf haploinsufficiency mediates intron retention in a tissue-specific manner
CTCF is a master regulator of gene transcription and chromatin organisation with occupancy at thousands of DNA target sites genome-wide. While CTCF is essential for cell survival, CTCF haploinsufficiency is associated with tumour development and hypermethylation. Increasing evidence demonstrates CTCF as a key player in several mechanisms regulating alternative splicing (AS), however, the genome-wide impact of Ctcf dosage on AS has not been investigated.
We examined the effect of Ctcf haploinsufficiency on gene expression and AS in five tissues from Ctcf hemizygous (Ctcf+/-) mice. Reduced Ctcf levels caused distinct tissue-specific differences in gene expression and AS in all tissues. An increase in intron retention (IR) was observed in Ctcf+/- liver and kidney. In liver, this specifically impacted genes associated with cytoskeletal organisation, splicing and metabolism. Strikingly, most differentially retained introns were short, with a high GC content and enriched in Ctcf binding sites in their proximal upstream genomic region. This study provides new insights into the effects of CTCF haploinsufficiency on organ transcriptomes and the role of CTCF in AS regulation
Із зали засідань Президії НАН України (11 липня 2012 року)
На черговому засіданні Президії НАН України 11 липня 2012 року члени Президії НАН України та запрошені заслухали такі питання: наукові повідомлення молодих учених НАН України (доповідачі — кандидат економічних наук І.С. Марченко, кандидат фізико-математичних наук Н.А. Курган, кандидат технічних наук Є.Л. Данильчук); високотемпературні надпровідники на основі заліза: дослідження та перспективи (доповідач — член-ко респондент НАН України О.А. Кордюк); про нагородження відзнаками НАН України та Почесними грамотами НАН України і Центрального комітету профспілки працівників НАН України (доповідач — академік НАН України В.Ф. Мачулін); кадрові та поточні питання
Geochemical Study of Natural CO2 Emissions in the French Massif Central: How to Predict Origin, Processes and Evolution of CO2 Leakage
International audienceThis study presents an overview of some results obtained within the French ANR (National Agency of Research) supported Géocarbone-Monitoring research program. The measurements were performed in Sainte-Marguerite, located in the French Massif Central. This site represents a natural laboratory for CO2/fluid/rock interactions studies, as well as CO2 migration mechanisms towards the surface. The CO2 leaking character of the studied area also allows to test and validate measurements methods and verifications for the future CO2 geological storage sites. During these surveys, we analyzed soil CO2 fluxes and concentrations. We sampled and analyzed soil gases, and gas from carbo-gaseous bubbling springs. A one-month continuous monitoring was also tested, to record the concentration of CO2 both in atmosphere and in the soil at a single point. We also developed a new methodology to collect soil gas samples for noble gas abundances and isotopic analyses, as well as carbon isotopic ratios. Our geochemical results, combined with structural geology, show that the leaking CO2 has a very deep origin, partially mantle derived. The gas rises rapidly along normal and strike-slip active faults. CO2 soil concentrations (also showing a mantle derived component) and CO2 fluxes are spatially variable, and reach high values. The recorded atmospheric CO2 is not very high, despite the important CO2 degassing throughout the whole area
First Observation of Coherent Production in Neutrino Nucleus Interactions with 2 GeV
The MiniBooNE experiment at Fermilab has amassed the largest sample to date
of s produced in neutral current (NC) neutrino-nucleus interactions at
low energy. This paper reports a measurement of the momentum distribution of
s produced in mineral oil (CH) and the first observation of coherent
production below 2 GeV. In the forward direction, the yield of events
observed above the expectation for resonant production is attributed primarily
to coherent production off carbon, but may also include a small contribution
from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino
flux, the sum of the NC coherent and diffractive modes is found to be (19.5
1.1 (stat) 2.5 (sys))% of all exclusive NC production at
MiniBooNE. These measurements are of immediate utility because they quantify an
important background to MiniBooNE's search for
oscillations.Comment: Submitted to Phys. Lett.
Single Spin Asymmetry in Polarized Proton-Proton Elastic Scattering at GeV
We report a high precision measurement of the transverse single spin
asymmetry at the center of mass energy GeV in elastic
proton-proton scattering by the STAR experiment at RHIC. The was measured
in the four-momentum transfer squared range \GeVcSq, the region of a significant interference between the
electromagnetic and hadronic scattering amplitudes. The measured values of
and its -dependence are consistent with a vanishing hadronic spin-flip
amplitude, thus providing strong constraints on the ratio of the single
spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated
by the Pomeron amplitude at this , we conclude that this measurement
addresses the question about the presence of a hadronic spin flip due to the
Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure
Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV
We report a measurement of the longitudinal double-spin asymmetry A_LL and
the differential cross section for inclusive Pi0 production at midrapidity in
polarized proton collisions at sqrt(s) = 200 GeV. The cross section was
measured over a transverse momentum range of 1 < p_T < 17 GeV/c and found to be
in good agreement with a next-to-leading order perturbative QCD calculation.
The longitudinal double-spin asymmetry was measured in the range of 3.7 < p_T <
11 GeV/c and excludes a maximal positive gluon polarization in the proton. The
mean transverse momentum fraction of Pi0's in their parent jets was found to be
around 0.7 for electromagnetically triggered events.Comment: 6 pages, 3 figures, submitted to Phys. Rev. D (RC
- …