Potential of modern circulating cell-free DNA diagnostic tools for detection of specific tumour cells in clinical practice

Personalized medicine is a developing field of medicine that has gained in importance in recent decades. New diagnostic tests based on the analysis of circulating cell-free DNA (cfDNA) were developed as a tool of diagnosing different cancer types. By detecting the subpopulation of mutated DNA from cancer cells, it is possible to detect the presence of a specific tumour in early stages of the disease. Mutation analysis is performed by quantitative polymerase chain reaction (qPCR) or the next generation sequencing (NGS), however, cfDNA protocols need to be modified carefully in preanalytical, analytical, and postanalytical stages. To further improve treatment of cancer the Food and Drug Administration approved more than 20 companion diagnostic tests that combine cancer drugs with highly efficient genetic diagnostic tools. Tools detect mutations in the DNA originating from cancer cells directly through the subpopulation of cfDNA, the circular tumour DNA (ctDNA) analysis or with visualization of cells through intracellular DNA probes. A large number of ctDNA tests in clinical studies demonstrate the importance of new findings in the field of cancer diagnosis. We describe the innovations in personalized medicine: techniques for detecting ctDNA and genomic DNA (gDNA) mutations approved Food and Drug Administration companion genetic diagnostics, candidate genes for assembling the cancer NGS panels, and a brief mention of the multitude of cfDNA currently in clinical trials. Additionally, an overview of the development steps of the diagnostic tools will refresh and expand the knowledge of clinics and geneticists for research opportunities beyond the development phases

Predicting and modelling the performance and ageing of proton exchange membrane fuel cells during startups and shutdowns

Nizkotemperaturne gorivne celice s protonsko izmenjevalno membrano (PEMFC) so ena od obetavnih tehnologij za doseganje ničelnih strupenih emisij pri težjih cestnih vozilih za transporte na daljših razdaljah. Čeprav je napredek na področju življenjske dobe, zmogljivosti in učinkovitosti PEMFC nesporen, pa pojavi degradacije individualnih komponent, ki so neločljivo povezani z neizogibnimi režimi delovanja, kot sta zagon in zaustavitev, ko gorivna celica deluje lokalno v elektrolizatorskem načinu, še vedno predstavljajo velik izziv, ki ga je potrebno nasloviti. V zaključni nalogi se osredotočamo na analiziranje elektrokemijskega dogajanja ob zagonu gorivne celice, ki direktno vpliva tako na zmogljivost kot tudi na dolgoživost gorivnoceličnih komponent. Na podlagi eksperimentalnih podatkov, v katerih je gorivna celica razdeljena na dvajset individualnih segmentov, smo parametrizirali elektrokemični model in simulirali zagon. Model na validacijskih podatkih izkazuje dobro napovednost, saj dosega visoko stopnjo ujemanja z eksperimentalnimi podatki z R2 vrednostmi za individualne segmente med 0,8883 in 0,9995, s povprečno vrednostjo 0,9780.Low-temperature fuel cells with a proton exchange membrane (PEMFC) are one of the more promising technologies for achieving zero poisonous emissions of heavier road vehicles on long distance travel. Even though the progress in the field of life expectancy, performance and efficiency of PEMFC is undisputible, the inevitable degradation of individual components, that are unequivocally connected with unavoidable operational regimes, like startups and shutdowns, when the fuel cells works locally in an electrolysis regime, still present a great challenge that needs to be addressed. In this paper, we focused on analysing the situation at fuel cell startup, that directly affect performance and longevity characteristics of fuel cell components. Based on experimental data in which the fuel cell is separated into twenty segments, we parametrised our electrochemical model and simulated a startup. The model exhibits great predictability, confirmed with a high level of correlation with experimental data with R2 values for individual segments raging between 0,8883 and 0,9995 with an average value of 0,9780

Viral and host genetic and epigenetic biomarkers related to SARS-CoV-2 cell entry, infection rate, and disease severity

The rapid spread of COVID-19 outbreak lead to a global pandemic declared in March 2020. The common features of corona virus family helped to resolve structural characteristics and entry mechanism of SARS-CoV-2. However, rapid mutagenesis leads to the emergence of new strains that may have different reproduction rates or infectivity and may impact the course and severity of the disease. Host related factors may also play a role in the susceptibility for infection as well as the severity and outcomes of the COVID-19. We have performed a literature and database search to summarize potential viral and host-related genomic and epigenomic biomarkers, such as genetic variability, miRNA, and DNA methylation in the molecular pathway of SARS-CoV-2 entry into the host cell, that may be related to COVID-19 susceptibility and severity. Bioinformatics tools may help to predict the effect of mutations in the spike protein on the binding to the ACE2 receptor and the infectivity of the strain. SARS-CoV-2 may also target several transcription factors and tumour suppressor genes, thus influencing the expression of different host genes and affecting cell signalling. In addition, the virus may interfere with RNA expression in host cells by exploiting endogenous miRNA and its viral RNA. Our analysis showed that numerous human miRNA may form duplexes with different coding and non-coding regions of viral RNA. Polymorphisms in human genes responsible for viral entry and replication, as well as in molecular damage response and inflammatory pathways may also contribute to disease prognosis and outcome. Gene ontology analysis shows that proteins encoded by such polymorphic genes are highly interconnected in regulation of defense response. Thus, virus and host related genetic and epigenetic biomarkers may help to predict the course of the disease and the response to treatment

Depletion of human serum albumin in embryo culture media for in vitro fertilization using monolithic columns with immobilized antibodies

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Globular Domain of the Prion Protein Needs to Be Unlocked by Domain Swapping to Support Prion Protein Conversion*

Prion diseases are fatal transmissible neurodegenerative diseases affecting many mammalian species. The normal prion protein (PrP) converts into a pathological aggregated form, PrPSc, which is enriched in the β-sheet structure. Although the high resolution structure of the normal PrP was determined, the structure of the converted form of PrP remains inaccessible to high resolution techniques. To map the PrP conversion process we introduced disulfide bridges into different positions within the globular domain of PrP, tethering selected secondary structure elements. The majority of tethered PrP mutants exhibited increased thermodynamic stability, nevertheless, they converted efficiently. Only the disulfides that tether subdomain B1-H1-B2 to subdomain H2-H3 prevented PrP conversion in vitro and in prion-infected cell cultures. Reduction of disulfides recovered the ability of these mutants to convert, demonstrating that the separation of subdomains is an essential step in conversion. Formation of disulfide-linked proteinase K-resistant dimers in fibrils composed of a pair of single cysteine mutants supports the model based on domain-swapped dimers as the building blocks of prion fibrils. In contrast to previously proposed structural models of PrPSc suggesting conversion of large secondary structural segments, we provide evidence for the conservation of secondary structural elements of the globular domain upon PrP conversion. Previous studies already showed that dimerization is the rate-limiting step in PrP conversion. We show that separation and swapping of subdomains of the globular domain is necessary for conversion. Therefore, we propose that the domain-swapped dimer of PrP precedes amyloid formation and represents a potential target for therapeutic intervention