263 research outputs found
Development of electrochemical sensor based on aptamer specific to lung cancer tumor marker
Electrochemical aptasensor is a sensor based on an indicator electrode covered with a layer of an aptamer that is able to bind target molecules with high specificity. In this work, DNA-aptamer LC-2108 specific to lung cancer tumor marker was immobilized onto the surface of golden screen-printed and disc electrodes. The electrodes were studied by conventional electrochemical methodsβcyclic voltammetry and electrochemical impedance spectroscopy. The current increase and electron transfer resistance decrease were registered. It seems as if the aptamer presence facilitated the electron transfer through the electrode-solution boundary. As the possible reasons of such an unusual electrochemical behavior we proposed the unordinary or irregular structure of the aptamer layer on the Au surface or the specific electrochemical properties of the aptamer itself
The Inhibition of CDK8/19 Mediator Kinases Prevents the Development of Resistance to EGFR-Targeting Drugs
Drug resistance is the main obstacle to achieving cures with both conventional and targeted anticancer drugs. The emergence of acquired drug resistance is initially mediated by non-genetic transcriptional changes, which occur at a much higher frequency than mutations and may involve population-scale transcriptomic adaptation. CDK8/19 kinases, through association with transcriptional Mediator complex, regulate transcriptional reprogramming by co-operating with different signal-responsive transcription factors. Here we tested if CDK8/19 inhibition could prevent adaptation to drugs acting on epidermal growth factor receptor (EGFR/ERBB1/HER1). The development of resistance was analyzed following long-term exposure of BT474 and SKBR3 breast cancer cells to EGFR-targeting small molecules (gefitinib, erlotinib) and of SW48 colon cancer cells to an anti-EGFR monoclonal antibody cetuximab. In all cases, treatment of small cell populations (~10 cells) with a single dose of the drug initially led to growth inhibition that was followed by the resumption of proliferation and development of drug resistance in the adapted populations. However, this adaptation was always prevented by the addition of selective CDK8/19 inhibitors, even though such inhibitors alone had only moderate or no effect on cell growth. These results indicate that combining EGFR-targeting drugs with CDK8/19 inhibitors may delay or prevent the development of tumor resistance to therapy
ΠΠΌΠΌΡΠ½ΠΎΡΠ΅ΡΠΌΠ΅Π½ΡΠ½ΡΠΉ Π°Π½Π°Π»ΠΈΠ· ΠΌΠ΅ΡΠ°Π±ΠΎΠ»ΠΈΡΠΎΠ² Π²ΠΈΡΠ°ΠΌΠΈΠ½Π° D3
We report herein improved version of the synthesis of hapten based on cholecalciferol and its active metabolite 25-hydroxycholecalcalferol. The methodology of obtaining high-molecular immunogenic conjugates of vitamin D3 derivatives with bovine serum albumin and horseradish peroxidase conjugates for direct ELISA was optimized. Immunisation of rabbits was carried out and polyclonal antibodies to 25-hydroxycholecalceferol were obtained and tested in an enzyme-linked immunosorbent assay. To improve the accuracy of the method, the sample preparation procedure was optimized, including the release of vitamin D3 and its active metabolites from complexes with vitamin D-binding protein.ΠΠΏΠΈΡΠ°Π½ ΡΠ»ΡΡΡΠ΅Π½Π½ΡΠΉ Π²Π°ΡΠΈΠ°Π½Ρ ΡΠΈΠ½ΡΠ΅Π·Π° Π³Π°ΠΏΡΠ΅Π½Π° Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ Ρ
ΠΎΠ»Π΅ΠΊΠ°Π»ΡΡΠΈΡΠ΅ΡΠΎΠ»Π° ΠΈ Π΅Π³ΠΎ Π°ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΠΌΠ΅ΡΠ°Π±ΠΎΠ»ΠΈΡΠ° 25-Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΡ
ΠΎΠ»Π΅ΠΊΠ°Π»ΡΡΠ΅ΡΠ΅ΡΠΎΠ»Π°. ΠΠΏΡΠΈΠΌΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΡ Π²ΡΡΠΎΠΊΠΎΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΡΡ
ΠΈΠΌΠΌΡΠ½ΠΎΠ³Π΅Π½Π½ΡΡ
ΠΊΠΎΠ½ΡΡΠ³Π°ΡΠΎΠ² ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄Π½ΡΡ
Π²ΠΈΡΠ°ΠΌΠΈΠ½Π° D3 Ρ Π±ΡΡΡΠΈΠΌ ΡΡΠ²ΠΎΡΠΎΡΠΎΡΠ½ΡΠΌ Π°Π»ΡΠ±ΡΠΌΠΈΠ½ΠΎΠΌ, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΊΠΎΠ½ΡΡΠ³Π°ΡΠΎΠ² Ρ ΠΏΠ΅ΡΠΎΠΊΡΠΈΠ΄Π°Π·ΠΎΠΉ Ρ
ΡΠ΅Π½Π° Π΄Π»Ρ ΠΏΡΡΠΌΠΎΠ³ΠΎ ΠΠ€Π. ΠΡΠΎΠ²Π΅Π΄Π΅Π½Π° ΠΈΠΌΠΌΡΠ½ΠΈΠ·Π°ΡΠΈΡ ΠΊΡΠΎΠ»ΠΈΠΊΠΎΠ², Π²ΡΠ΄Π΅Π»Π΅Π½Ρ ΠΏΠΎΠ»ΠΈΠΊΠ»ΠΎΠ½Π°Π»ΡΠ½ΡΠ΅ Π°Π½ΡΠΈΡΠ΅Π»Π° ΠΊ 25-Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΡ
ΠΎΠ»Π΅ΠΊΠ°Π»ΡΡΠ΅ΡΠ΅ΡΠΎΠ»Ρ, ΠΊΠΎΡΠΎΡΡΠ΅ ΠΈΡΠΏΡΡΠ°Π½Ρ Π² ΠΈΠΌΠΌΡΠ½ΠΎΡΠ΅ΡΠΌΠ΅Π½ΡΠ½ΠΎΠΌ Π°Π½Π°Π»ΠΈΠ·Π΅. ΠΠ»Ρ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΡ ΡΠΎΡΠ½ΠΎΡΡΠΈ ΠΌΠ΅ΡΠΎΠ΄Π° ΠΎΠΏΡΠΈΠΌΠΈΠ·ΠΈΡΠΎΠ²Π°Π½ ΠΏΡΠΎΡΠ΅ΡΡ ΠΏΡΠΎΠ±ΠΎΠΏΠΎΠ΄Π³ΠΎΡΠΎΠ²ΠΊΠΈ, Π²ΠΊΠ»ΡΡΠ°ΡΡΠΈΠΉ Π²ΡΡΠ²ΠΎΠ±ΠΎΠΆΠ΄Π΅Π½ΠΈΠ΅ Π²ΠΈΡΠ°ΠΌΠΈΠ½Π° D3 ΠΈ Π΅Π³ΠΎ Π°ΠΊΡΠΈΠ²Π½ΡΡ
ΠΌΠ΅ΡΠ°Π±ΠΎΠ»ΠΈΡΠΎΠ² ΠΈΠ· ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΠ² Ρ Π²ΠΈΡΠ°ΠΌΠΈΠ½ D-ΡΠ²ΡΠ·ΡΠ²Π°ΡΡΠΈΠΌ Π±Π΅Π»ΠΊΠΎΠΌ
Topology of the spaces of Morse functions on surfaces
Let be a smooth closed orientable surface, and let be the space of
Morse functions on such that at least critical points of each
function of are labeled by different labels (enumerated). Endow the space
with -topology. We prove the homotopy equivalence where is one of the manifolds , and the point in dependence on the sign of ,
and is the universal moduli space of framed Morse
functions, which is a smooth stratified manifold. Morse inequalities for the
Betti numbers of the space are obtained.Comment: 15 pages, in Russia
Methamphetamine withdrawal induces activation of CRF neurons in the brain stress system in parallel with an increased activity of cardiac sympathetic pathways.
Methamphetamine (METH) addiction is a major public health problem in some countries. There is evidence to suggest that METH use is associated with increased risk of developing cardiovascular problems. Here, we investigated the effects of chronic METH administration and withdrawal on the activation of the brain stress system and cardiac sympathetic pathways. Mice were treated with METH (2Β mg/kg, i.p.) for 10Β days and left to spontaneous withdraw for 7Β days. The number of corticotrophin-releasing factor (CRF), c-Fos, and CRF/c-Fos neurons was measured by immunohistochemistry in the paraventricular nucleus of the hypothalamus (PVN) and the oval region of the bed nucleus of stria terminalis (ovBNST), two regions associated with cardiac sympathetic control. In parallel, levels of catechol-o-methyl-transferase (COMT), tyrosine hydroxylase (TH), and heat shock protein 27 (Hsp27) were measured in the heart. In the brain, chronic-METH treatment enhanced the number of c-Fos neurons and the CRF neurons with c-Fos signal (CRF+/c-Fos+) in PVN and ovBNST. METH withdrawal increased the number of CRF+neurons. In the heart, METH administration induced an increase in soluble (S)-COMT and membrane-bound (MB)-COMT without changes in phospho (p)-TH, Hsp27, or pHsp27. Similarly, METH withdrawal increased the expression of S- and MB-COMT. In contrast to chronic treatment, METH withdrawal enhanced levels of (p)TH and (p)Hsp27 in the heart. Overall, our results demonstrate that chronic METH administration and withdrawal activate the brain CRF systems associated with the heart sympathetic control and point towards a METH withdrawal induced activation of sympathetic pathways in the heart. Our findings provide further insight in the mechanism underlining the cardiovascular risk associated with METH use and proposes targets for its treatment
Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of mesons
The production of vector mesons in deep inelastic scattering is an
interesting yet scarsely explored channel to study the transverse spin
structure of the nucleon and the related phenomena. The COMPASS collaboration
has performed the first measurement of the Collins and Sivers asymmetries for
inclusively produced mesons. The analysis is based on the data set
collected in deep inelastic scattering in using a
beam impinging on a transversely polarized target. The
mesons are selected from oppositely charged hadron pairs, and the
asymmetries are extracted as a function of the Bjorken- variable, the
transverse momentum of the pair and the fraction of the energy carried by
the pair. Indications for positive Collins and Sivers asymmetries are observed
High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons
New results are presented on a high-statistics measurement of Collins and
Sivers asymmetries of charged hadrons produced in deep inelastic scattering of
muons on a transversely polarised LiD target. The data were taken in 2022
with the COMPASS spectrometer using the 160 \gevv\ muon beam at CERN, balancing
the existing data on transversely polarised proton targets. The first results
from about two-thirds of the new data have total uncertainties smaller by up to
a factor of three compared to the previous deuteron measurements. Using all the
COMPASS proton and deuteron results, both the transversity and the Sivers
distribution functions of the and quark, as well as the tensor charge
in the measured -range are extracted. In particular, the accuracy of the
quark results is significantly improved
Spin Density Matrix Elements in Exclusive Meson Muoproduction
We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard
exclusive meson muoproduction at COMPASS using 160~GeV/ polarised
and beams impinging on a liquid hydrogen target. The
measurement covers the kinematic range 5.0~GeV/ 17.0~GeV/,
1.0 (GeV/) 10.0 (GeV/) and 0.01 (GeV/) 0.5 (GeV/). Here, denotes the mass of the final
hadronic system, the virtuality of the exchanged photon, and
the transverse momentum of the meson with respect to the
virtual-photon direction. The measured non-zero SDMEs for the transitions of
transversely polarised virtual photons to longitudinally polarised vector
mesons () indicate a violation of -channel helicity
conservation. Additionally, we observe a dominant contribution of
natural-parity-exchange transitions and a very small contribution of
unnatural-parity-exchange transitions, which is compatible with zero within
experimental uncertainties. The results provide important input for modelling
Generalised Parton Distributions (GPDs). In particular, they may allow one to
evaluate in a model-dependent way the role of parton helicity-flip GPDs in
exclusive production
Metagenomic profiling of viral and microbial communities from the pox lesions of lumpy skin disease virus and sheeppox virus-infected hosts
IntroductionIt has been recognized that capripoxvirus infections have a strong cutaneous tropism with the manifestation of skin lesions in the form of nodules and scabs in the respective hosts, followed by necrosis and sloughing off. Considering that the skin microbiota is a complex community of commensal bacteria, fungi and viruses that are influenced by infections leading to pathological states, there is no evidence on how the skin microbiome is affected during capripoxvirus pathogenesis.MethodsIn this study, shotgun metagenomic sequencing was used to investigate the microbiome in pox lesions from hosts infected with lumpy skin disease virus and sheep pox virus.ResultsThe analysis revealed a high degree of variability in bacterial community structures across affected skin samples, indicating the importance of specific commensal microorganisms colonizing individual hosts. The most common and abundant bacteria found in scab samples were Fusobacterium necrophorum, Streptococcus dysgalactiae, Helcococcus ovis and Trueperella pyogenes, irrespective of host. Bacterial reads belonging to the genera Moraxella, Mannheimia, Corynebacterium, Staphylococcus and Micrococcus were identified.DiscussionThis study is the first to investigate capripox virus-associated changes in the skin microbiome using whole-genome metagenomic profiling. The findings will provide a basis for further investigation into capripoxvirus pathogenesis. In addition, this study highlights the challenge of selecting an optimal bioinformatics approach for the analysis of metagenomic data in clinical and veterinary practice. For example, direct classification of reads using a kmer-based algorithm resulted in a significant number of systematic false positives, which may be attributed to the peculiarities of the algorithm and database selection. On the contrary, the process of de novo assembly requires a large number of target reads from the symbiotic microbial community. In this work, the obtained sequencing data were processed by three different approaches, including direct classification of reads based on k-mers, mapping of reads to a marker gene database, and de novo assembly and binning of metagenomic contigs. The advantages and disadvantages of these techniques and their practicality in veterinary settings are discussed in relation to the results obtained
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