131 research outputs found
Сучасні концепції і стратегії підвищення популярності українських періодичних видань: боротьба за ринок
У статті розглядаються особливості розвитку сучасного українського ринку друкованих засобів масової інформації. Увага акцентована на специфіці просування українського інформаційного “продукту", успішному веденню газетної справи як бізнесової сфери діяльності.В статье рассматриваются особенности развития рынка печатных средств массовой информации Украины. Внимание акцентировано на специфике продвижения украинского информационного "продукта", особенностях организации печатного издания как бизнес-проекта.This article searches features of market development of printing mass medias of Ukraine are examined in the article. Attention is accented on the specific of advancement of the Ukrainian informative "product", to the features of organization of printing edition as business of project
On-chip interrogator based on Fourier Transform spectroscopy
In this paper, the design and the characterization of a novel interrogator
based on integrated Fourier transform (FT) spectroscopy is presented. To the
best of our knowledge, this is the first integrated FT spectrometer used for
the interrogation of photonic sensors. It consists of a planar spatial
heterodyne spectrometer, which is implemented using an array of Mach-Zehnder
interferometers (MZIs) with different optical path differences. Each MZI
employs a 33 multi-mode interferometer, allowing the retrieval of the
complex Fourier coefficients. We derive a system of non-linear equations whose
solution, which is obtained numerically from Newton's method, gives the
modulation of the sensor's resonances as a function of time. By taking one of
the sensors as a reference, to which no external excitation is applied and its
temperature is kept constant, about 92 of the thermal induced phase drift
of the integrated MZIs has been compensated. The minimum modulation amplitude
that is obtained experimentally is 400 fm, which is more than two orders of
magnitude smaller than the FT spectrometer resolution.Comment: 15 pages, 6 figure
Diagnosis of Fanconi Anemia: Mutation Analysis by Next-Generation Sequencing
Fanconi anemia (FA) is a rare genetic instability syndrome characterized by developmental defects, bone marrow failure, and a high cancer risk. Fifteen genetic subtypes have been distinguished. The majority of patients (≈85%) belong to the subtypes A (≈60%), C (≈15%) or G (≈10%), while a minority (≈15%) is distributed over the remaining 12 subtypes. All subtypes seem to fit within the “classical” FA phenotype, except for D1 and N patients, who have more severe clinical symptoms. Since FA patients need special clinical management, the diagnosis should be firmly established, to exclude conditions with overlapping phenotypes. A valid FA diagnosis requires the detection of pathogenic mutations in a FA gene and/or a positive result from a chromosomal breakage test. Identification of the pathogenic mutations is also important for adequate genetic counselling and to facilitate prenatal or preimplantation genetic diagnosis. Here we describe and validate a comprehensive protocol for the molecular diagnosis of FA, based on massively parallel sequencing. We used this approach to identify BRCA2, FANCD2, FANCI and FANCL mutations in novel unclassified FA patients
Correlation of gene expression with magnetic resonance imaging features of retinoblastoma: a multi-center radiogenomics validation study
OBJECTIVES
To validate associations between MRI features and gene expression profiles in retinoblastoma, thereby evaluating the repeatability of radiogenomics in retinoblastoma.
METHODS
In this retrospective multicenter cohort study, retinoblastoma patients with gene expression data and MRI were included. MRI features (scored blinded for clinical data) and matched genome-wide gene expression data were used to perform radiogenomic analysis. Expression data from each center were first separately processed and analyzed. The end product normalized expression values from different sites were subsequently merged by their Z-score to permit cross-sites validation analysis. The MRI features were non-parametrically correlated with expression of photoreceptorness (radiogenomic analysis), a gene expression signature informing on disease progression. Outcomes were compared to outcomes in a previous described cohort.
RESULTS
Thirty-six retinoblastoma patients were included, 15 were female (42%), and mean age was 24 (SD 18) months. Similar to the prior evaluation, this validation study showed that low photoreceptorness gene expression was associated with advanced stage imaging features. Validated imaging features associated with low photoreceptorness were multifocality, a tumor encompassing the entire retina or entire globe, and a diffuse growth pattern (all p < 0.05). There were a number of radiogenomic associations that were also not validated.
CONCLUSIONS
A part of the radiogenomic associations could not be validated, underlining the importance of validation studies. Nevertheless, cross-center validation of imaging features associated with photoreceptorness gene expression highlighted the capability radiogenomics to non-invasively inform on molecular subtypes in retinoblastoma.
CLINICAL RELEVANCE STATEMENT
Radiogenomics may serve as a surrogate for molecular subtyping based on histopathology material in an era of eye-sparing retinoblastoma treatment strategies.
KEY POINTS
- Since retinoblastoma is increasingly treated using eye-sparing methods, MRI features informing on molecular subtypes that do not rely on histopathology material are important.
- A part of the associations between retinoblastoma MRI features and gene expression profiles (radiogenomics) were validated.
- Radiogenomics could be a non-invasive technique providing information on the molecular make-up of retinoblastoma
Somatic genomic alterations in retinoblastoma beyond RB1 are rare and limited to copy number changes
Retinoblastoma is a rare childhood cancer initiated by RB1 mutation or MYCN amplification, while additional alterations may be required for tumor development. However, the view on single nucleotide variants is very limited. To better understand oncogenesis, we determined the genomic landscape of retinoblastoma. We performed exome sequencing of 71 retinoblastomas and matched blood DNA. Next, we determined the presence of single nucleotide variants, copy number alterations and viruses. Aside from RB1, recurrent gene mutations were very rare. Only a limited fraction of tumors showed BCOR (7/71, 10%) or CREBBP alterations (3/71, 4%). No evidence was found for the presence of viruses. Instead, specific somatic copy number alterations were more common, particularly in patients diagnosed at later age. Recurrent alterations of chromosomal arms often involved less than one copy, also in highly pure tumor samples, suggesting within-tumor heterogeneity. Our results show that retinoblastoma is among the least mutated cancers and signify the extreme sensitivity of the childhood retina for RB1 loss. We hypothesize that retinoblastomas arising later in retinal development benefit more from subclonal secondary alterations and therefore, these alterations are more selected for in these tumors. Targeted therapy based on these subclonal events might be insufficient for complete tumor control
Treatment of hip/knee osteoarthritis in Dutch general practice and physical therapy practice: an observational study
Cigarette smoke induces genetic instability in airway epithelial cells by suppressing FANCD2 expression
Chromosomal abnormalities are commonly found in bronchogenic carcinoma cells, but the molecular causes of chromosomal instability (CIN) and their relationship to cigarette smoke has not been defined. Because the Fanconi anaemia (FA)/BRCA pathway is essential for maintenance of chromosomal stability, we tested the hypothesis that cigarette smoke suppresses that activity of this pathway. Here, we show that cigarette smoke condensate (CSC) inhibited translation of FANCD2 mRNA (but not FANCC or FANCG) in normal airway epithelial cells and that this suppression of FANCD2 expression was sufficient to induce both genetic instability and programmed cell death in the exposed cell population. Cigarette smoke condensate also suppressed FANCD2 function and induced CIN in bronchogenic carcinoma cells, but these cells were resistant to CSC-induced apoptosis relative to normal airway epithelial cells. We, therefore, suggest that CSC exerts pressure on airway epithelial cells that results in selection and emergence of genetically unstable somatic mutant clones that may have lost the capacity to effectively execute an apoptotic programme. Carcinogen-mediated suppression of FANCD2 gene expression provides a plausible molecular mechanism for CIN in bronchogenic carcinogenesis
Centromere promoter factors (CPF1) of the yeasts Saccharomyces cerevisiae and Kluyveromyces lactis are functionally exchangeable, despite low overall homology
Rescue of replication failure by Fanconi anaemia proteins
Chromosomal aberrations are often associated with incomplete genome duplication, for instance at common fragile sites, or as a consequence of chemical alterations in the DNA template that block replication forks. Studies of the cancer-prone disease Fanconi anaemia (FA) have provided important insights into the resolution of replication problems. The repair of interstrand DNA crosslinks induced by chemotherapy drugs is coupled with DNA replication and controlled by FA proteins. We discuss here the recent discovery of new FA-associated proteins and the development of new tractable repair systems that have dramatically improved our understanding of crosslink repair. We focus also on how FA proteins protect against replication failure in the context of fragile sites and on the identification of reactive metabolites that account for the development of Fanconi anaemia symptoms
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