Structural insights into i-motif DNA structures in sequences from the insulin-linked polymorphic region.

The insulin-linked polymorphic region is a variable number of tandem repeats region of DNA in the promoter of the insulin gene that regulates transcription of insulin. This region is known to form the alternative DNA structures, i-motifs and G-quadruplexes. Individuals have different sequence variants of tandem repeats and although previous work investigated the effects of some variants on G-quadruplex formation, there is not a clear picture of the relationship between the sequence diversity, the DNA structures formed, and the functional effects on insulin gene expression.

Localization and classification of scattered nonlinear ultrasonic signatures in bio-mechanical media using time reversal approach.

This paper deals with the time reversal approach along with signal classification using ϕ-divergences in biomedical applications for localization and statistical classification of ultrasonic nonlinearities. The time reversal (TR) approach in combination with nonlinear elastic wave spectroscopy (NEWS) is used to obtain the nonlinear signature of air bubbles with different sizes and ultrasound contrast agents in a liquid. An optimized chirp-coded signal in the range of 0.

Guanine quadruplexes in the RNA genome of the tick-borne encephalitis virus: their role as a new antiviral target and in virus biology.

We have identified seven putative guanine quadruplexes (G4) in the RNA genome of tick-borne encephalitis virus (TBEV), a flavivirus causing thousands of human infections and numerous deaths every year. The formation of G4s was confirmed by biophysical methods on synthetic oligonucleotides derived from the predicted TBEV sequences. TBEV-5, located at the NS4b/NS5 boundary and conserved among all known flaviviruses, was tested along with its mutated variants for interactions with a panel of known G4 ligands, for the ability to affect RNA synthesis by the flaviviral RNA-dependent RNA polymerase (RdRp) and for effects on TBEV replication fitness in cells.

Systematic investigation of sequence requirements for DNA i-motif formation.

The formation of intercalated motifs (iMs) - secondary DNA structures based on hemiprotonated C.C+ pairs in suitable cytosine-rich DNA sequences, is reflected by typical changes in CD and UV absorption spectra. By means of spectroscopic methods, electrophoresis, chemical modifications and other procedures, we characterized iM formation and stability in sequences with different cytosine block lengths interrupted by various numbers and types of nucleotides.

Socioeconomic and gender inequalities in smoking. Findings from the Czech National Tobacco Surveys 2012-2015.

Objective: Smoking significantly affects morbidity and mortality of the population. The incidence of smoking is determined by gender and socioeconomic status (SES) of an individual. The aim of this study is to analyse the relationship between gender and SES indicators and smoking.

Spectroscopic insights into quadruplexes of five-repeat telomere DNA sequences upon G-block damage.

Background: The DNA lesions, resulting from oxidative damage, were shown to destabilize human telomere four-repeat quadruplex and to alter its structure. Long telomere DNA, as a repetitive sequence, offers, however, other mechanisms of dealing with the lesion: extrusion of the damaged repeat into loop or shifting the quadruplex position by one repeat.

Methods: Using circular dichroism and UV absorption spectroscopy and polyacrylamide electrophoresis, we studied consequences of lesions at different positions of the model five-repeat human telomere DNA sequences on the structure and stability of their quadruplexes in sodium and in potassium.

Clustered abasic lesions profoundly change the structure and stability of human telomeric G-quadruplexes.

Ionizing radiation produces clustered damage to DNA which is difficult to repair and thus more harmful than single lesions. Clustered lesions have only been investigated in dsDNA models. Introducing the term 'clustered damage to G-quadruplexes' we report here on the structural effects of multiple tetrahydrofuranyl abasic sites replacing loop adenines (A/AP) and tetrad guanines (G/AP) in quadruplexes formed by the human telomere d[AG3(TTAG3)3] (htel-22) and d[TAG3(TTAG3)3TT] (htel-25) in K+ solutions.

Wild-type p53 binds to MYC promoter G-quadruplex.

G-quadruplexes are four-stranded nucleic acid structures that are implicated in the regulation of transcription, translation and replication. Genome regions enriched in putative G-quadruplex motifs include telomeres and gene promoters. Tumour suppressor p53 plays a critical role in regulatory pathways leading to cell cycle arrest, DNA repair and apoptosis.

Time reversal transfer: Exploring the robustness of time reversed acoustics in media with geometry perturbations.

In this letter, fundamentals of transferring a time reversal experiment between similar objects are discussed. The time reversal experiment consists of two steps: forward propagation, when a source excites the medium and a complex wave field is created, and back propagation, resulting in time reversal focusing. Here the procedure of performing the first step on one specimen and the second step on another is investigated.

Diverse effects of naturally occurring base lesions on the structure and stability of the human telomere DNA quadruplex.

Various base lesions continuously form in cellular nucleic acids and the unrepaired lesions are promutagenic and procarcinogenic. Though natural base lesions have been extensively studied in double-stranded DNA models, these studies are only less than a decade old for non-canonical DNA models, such as quadruplexes. Here we present a report on the effects of three frequently occurring natural lesions that can form in the TTA loops on the structure of the human telomere quadruplex d[AG3(TTAG3)3].

Observation of the 3n evaporation channel in the complete hot-fusion reaction 26Mg + 248Cm leading to the new superheavy nuclide 271Hs.

The analysis of a large body of heavy ion fusion reaction data with medium-heavy projectiles (6 < or = Z < or = 18) and actinide targets suggests a disappearance of the 3n exit channel with increasing atomic number of the projectile. Here, we report a measurement of the excitation function of the reaction (248)Cm ((26)Mg,xn)(274-x)Hs and the observation of the new nuclide (271)Hs produced in the 3n evaporation channel at a beam energy well below the Bass fusion barrier with a cross section comparable to the maxima of the 4n and 5n channels. This indicates the possible discovery of new neutron-rich transactinide nuclei using relatively light heavy ion beams of the most neutron-rich stable isotopes and actinide targets.

Target burn-up corrected specific activity of 177Lu produced via 176Lu(n, gamma) 177Lu nuclear reactions.

Nuclear transformation of the target material is considered as an essential parameter for the specific activity of (177)Lu produced via (176)Lu(n, gamma)(177)Lu nuclear reactions. It is shown that (176)Lu burn-up has to be taken into account to estimate the (177)Lu specific activity related to the total mass or amount of lutetium in the system.

Production of 177Lu at the new research reactor FRM-II: Irradiation yield of 176Lu(n,gamma)177Lu.

Due to its physical and chemical characteristics, 177Lu is a very attractive radionuclide for use in nuclear medicine. This paper introduces a method for a precise calculation of the irradiation yield of 177Lu produced by neutron activation of 176Lu in a nuclear reactor. The calculation is based on the Westcott convention which requires the knowledge of the neutron flux parameters.

[The detection of p16 protein in uterine cervix lesions].

Objective: The detection of p16 in oncocytology and in the surgical pathology of the uterine cervix.

Setting: Department of Pathology and Department of Gynaecology and Obstetrics, University Hospital Brno.

Methods: An imunocytochemical and immunohistochemical analysis of formalin-fixed, paraffin embedded samples of the uterine cervix (included knips biopsies) and liquid based smears was performed.

[The cytology laboratory of the 2d Institute of Pathology and Anatomy in Brno (present status, perspectives, problems)].

The laboratory was engaged in exfoliative cytology, mainly of sputa and investigated 1450 hospitalized patients and 1410 smokers in a screening campaign during the last year. Another programme included cytology of bronchoscopical materials (2480 patients a year), fine needle aspiration cytology (550 patients), and peroperation cytology, mostly pulmonary and mammary (125 patients). A limited number of exfoliative and bronchoscopical materials could have been examined in correlation with the number of medical technologists for screening and preliminary evaluation.