BACKGROUND: Surgery for Stanford type A aortic dissection (TAAD) is associated with an increased risk of late aortic reoperations due to degeneration of the dissected aorta. METHODS: The subjects of this analysis were 990 TAAD patients who survived surgery for acute TAAD and had complete data on the diameter and dissection status of all aortic segments. RESULTS: After a mean follow-up of 4.2 ± 3.6 years, 60 patients underwent 85 distal aortic reoperations. Ten-year cumulative incidence of distal aortic reoperation was 9.6%. Multivariable competing risk analysis showed that the maximum preoperative diameter of the abdominal aorta (SHR 1.041, 95%CI 1.008-1.075), abdominal aorta dissection (SHR 2.133, 95%CI 1.156-3.937) and genetic syndromes (SHR 2.840, 95%CI 1.001-8.060) were independent predictors of distal aortic reoperation. Patients with a maximum diameter of the abdominal aorta >30 mm and/or abdominal aortic dissection had a cumulative incidence of 10-year distal aortic reoperation of 12.0% compared to 5.7% in those without these risk factors (adjusted SHR 2.076, 95%CI 1.062-4.060). CONCLUSION: TAAD patients with genetic syndromes, and increased size and dissection of the abdominal aorta have an increased the risk of distal aortic reoperations. A policy of extensive surgical or hybrid primary aortic repair, completion endovascular procedures for aortic remodeling and tight surveillance may be justified in these patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04831073.
- MeSH
- aneurysma hrudní aorty * chirurgie MeSH
- aorta abdominalis diagnostické zobrazování chirurgie MeSH
- aortální aneurysma * chirurgie MeSH
- azidy * MeSH
- cévy - implantace protéz * škodlivé účinky MeSH
- deoxyglukosa analogy a deriváty MeSH
- disekce aorty * diagnostické zobrazování chirurgie MeSH
- lidé MeSH
- reoperace MeSH
- retrospektivní studie MeSH
- rizikové faktory MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
I-Motifs (iM) are non-canonical DNA structures potentially forming in the accessible, single-stranded, cytosine-rich genomic regions with regulatory roles. Chromatin, protein interactions, and intracellular properties seem to govern iM formation at sites with i-motif formation propensity (iMFPS) in human cells, yet their specific contributions remain unclear. Using in-cell NMR with oligonucleotide iMFPS models, we monitor iM-associated structural equilibria in asynchronous and cell cycle-synchronized HeLa cells at 37 °C. Our findings show that iMFPS displaying pHT < 7 under reference in vitro conditions occur predominantly in unfolded states in cells, while those with pHT > 7 appear as a mix of folded and unfolded states depending on the cell cycle phase. Comparing these results with previous data obtained using an iM-specific antibody (iMab) reveals that cell cycle-dependent iM formation has a dual origin, and iM formation concerns only a tiny fraction (possibly 1%) of genomic sites with iM formation propensity. We propose a comprehensive model aligning observations from iMab and in-cell NMR and enabling the identification of iMFPS capable of adopting iM structures under physiological conditions in living human cells. Our results suggest that many iMFPS may have biological roles linked to their unfolded states.
- MeSH
- azidy * MeSH
- benzazepiny * MeSH
- DNA MeSH
- HeLa buňky MeSH
- lidé MeSH
- magnetická rezonanční tomografie * MeSH
- protilátky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Surgery for type A aortic dissection (TAAD) is associated with a high risk of early mortality. The prognostic impact of a new classification of the urgency of the procedure was evaluated in this multicenter cohort study. Data on consecutive patients who underwent surgery for acute TAAD were retrospectively collected in the multicenter, retrospective European Registry of TAAD (ERTAAD). The rates of in-hospital mortality of 3,902 consecutive patients increased along with the ERTAAD procedure urgency grades: urgent procedure 10.0%, emergency procedure grade 1 13.3%, emergency procedure grade 2 22.1%, salvage procedure grade 1 45.6%, and salvage procedure grade 2 57.1% (p <0.0001). Preoperative arterial lactate correlated with the urgency grades. Inclusion of the ERTAAD procedure urgency classification significantly improved the area under the receiver operating characteristics curves of the regression model and the integrated discrimination indexes and the net reclassification indexes. The risk of postoperative stroke/global brain ischemia, mesenteric ischemia, lower limb ischemia, dialysis, and acute heart failure increased along with the urgency grades. In conclusion, the urgency of surgical repair of acute TAAD, which seems to have a significant impact on the risk of in-hospital mortality, may be useful to improve the stratification of the operative risk of these critically ill patients. This study showed that salvage surgery for TAAD is justified because half of the patients may survive to discharge.
- Klíčová slova
- bioortogonální chemie,
- MeSH
- alkyny chemie MeSH
- azidy chemie MeSH
- chemické jevy MeSH
- click chemie * metody MeSH
- cykloadiční reakce klasifikace metody přístrojové vybavení MeSH
- výzkum MeSH
- Publikační typ
- přehledy MeSH
Mycobacterium avium subsp. paratuberculosis (MAP) is a pathogenic bacterium causing the paratuberculosis, chronic and infectious disease common particularly in wild and domestic ruminants. Currently, culture techniques to detect viable MAP are still used most commonly, although these require a long incubation period. Consequently, a faster molecular method for assessing MAP cell viability based on cell membrane integrity was introduced consisting of sample treatment with the intercalation dye propidium monoazide (PMA) followed by quantitative PCR (qPCR). However, the PMA-qPCR assay is complicated by demanding procedures involving work in a darkroom and on ice. In this study, we therefore optimized a viability assay combining sample treatment with palladium (Pd) compounds as an alternative viability marker to PMA, which does not require such laborious procedures, with subsequent qPCR. The optimized Pd-qPCR conditions consisting of 90 min exposure to 30 μM bis(benzonitrile)dichloropalladium(II) or 30 μM palladium(II)acetate at 5 °C and using ultrapure water as a resuspension medium resulted in differences in quantification cycle (Cq) values between treated live and dead MAP cells of 8.5 and 7.9, respectively, corresponding to approximately 2.5 log units. In addition, Pd-qPCR proved to be superior to PMA-qPCR in distinguishing between live and dead MAP cells. The Pd-qPCR viability assay thus has the potential to replace time-consuming culture methods and demanding PMA-qPCR in the detection and quantification of viable MAP cells with possible application in food, feed, clinical and environmental samples.
- MeSH
- azidy farmakologie MeSH
- biotest MeSH
- kvantitativní polymerázová řetězová reakce metody MeSH
- mikrobiální viabilita MeSH
- Mycobacterium avium subsp. paratuberculosis * genetika MeSH
- palladium farmakologie MeSH
- paratuberkulóza * mikrobiologie MeSH
- propidium farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim and novelty of this paper are found in assessing the influence of inhibitors and antibiotics on intact cell MALDI-TOF mass spectra of the cyanobacterium Synechococcus sp. UPOC S4 and to check the impact on reliability of identification. Defining the limits of this method is important for its use in biology and applied science. The compounds included inhibitors of respiration, glycolysis, citrate cycle, and proteosynthesis. They were used at 1-10 μM concentrations and different periods of up to 3 weeks. Cells were also grown without inhibitors in a microgravity because of expected strong effects. Mass spectra were evaluated using controls and interpreted in terms of differential peaks and their assignment to protein sequences by mass. Antibiotics, azide, and bromopyruvate had the greatest impact. The spectral patterns were markedly altered after a prolonged incubation at higher concentrations, which precluded identification in the database of reference spectra. The incubation in microgravity showed a similar effect. These differences were evident in dendrograms constructed from the spectral data. Enzyme inhibitors affected the spectra to a smaller extent. This study shows that only a long-term presence of antibiotics and strong metabolic inhibitors in the medium at 10-5 M concentrations hinders the correct identification of cyanobacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF).
- MeSH
- antibakteriální látky toxicita MeSH
- antimycin A analogy a deriváty toxicita MeSH
- azidy toxicita MeSH
- buněčné dýchání účinky léků MeSH
- chloramfenikol toxicita MeSH
- citrátový cyklus účinky léků MeSH
- deoxyglukosa toxicita MeSH
- fluoracetáty toxicita MeSH
- glykolýza účinky léků MeSH
- malonáty toxicita MeSH
- proteosyntéza účinky léků MeSH
- pyruváty toxicita MeSH
- reprodukovatelnost výsledků MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- stav beztíže MeSH
- streptomycin toxicita MeSH
- Synechococcus chemie účinky léků izolace a purifikace metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Antifouling polymer layers containing extracellular matrix-derived peptide motifs offer promising new options for biomimetic surface engineering. In this contribution, we report the design of antifouling vascular grafts bearing biofunctional peptide motifs for tissue regeneration applications based on hierarchical polymer brushes. Hierarchical diblock poly(methyl ether oligo(ethylene glycol) methacrylate-block-glycidyl methacrylate) brushes bearing azide groups (poly(MeOEGMA-block-GMA-N3)) were grown by surface-initiated atom transfer radical polymerization (SI-ATRP) and functionalized with biomimetic RGD peptide sequences. Varying the conditions of copper-catalyzed alkyne-azide "click" reaction allowed for the immobilization of RGD peptides in a wide surface concentration range. The synthesized hierarchical polymer brushes bearing peptide motifs were characterized in detail using various surface sensitive physicochemical methods. The hierarchical brushes presenting the RGD sequences provided excellent cell adhesion properties and at the same time remained resistant to fouling from blood plasma. The synthesis of anti-fouling hierarchical brushes bearing 1.2 × 103 nmol/cm2 RGD biomimetic sequences has been adapted for the surface modification of commercially available grafts of woven polyethylene terephthalate (PET) fibers. The fiber mesh was endowed with polymerization initiator groups via aminolysis and acylation reactions optimized for the material. The obtained bioactive antifouling vascular grafts promoted the specific adhesion and growth of endothelial cells, thus providing a potential avenue for endothelialization of artificial conduits.
- MeSH
- adsorpce MeSH
- aminokyselinové motivy MeSH
- azidy chemie MeSH
- biokompatibilní potahované materiály * MeSH
- biomimetické materiály * MeSH
- buněčná adheze MeSH
- buněčné dělení MeSH
- cévní endotel fyziologie MeSH
- cévní protézy * MeSH
- click chemie MeSH
- endoteliální buňky pupečníkové žíly (lidské) MeSH
- imobilizované proteiny MeSH
- křemík MeSH
- krevní plazma MeSH
- krevní proteiny MeSH
- lidé MeSH
- oligopeptidy chemie MeSH
- polyethylentereftaláty chemie MeSH
- polymerizace * MeSH
- povrchové vlastnosti MeSH
- řízená tkáňová regenerace přístrojové vybavení MeSH
- sklo MeSH
- testování materiálů MeSH
- trombóza prevence a kontrola MeSH
- zlato MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
To tailor cell-surface interactions, precise and controlled attachment of cell-adhesive motifs is required, while any background non-specific cell and protein adhesion has to be blocked effectively. Herein, a versatile and highly reproducible antifouling surface modification based on "clickable" groups and hierarchically structured diblock copolymer brushes for the controlled attachment of cells is reported. The polymer brush architecture combines an antifouling bottom block of poly(2-hydroxyethyl methacrylate) poly(HEMA) and an ultrathin azide-bearing top block, which can participate in well-established "click" reactions including the highly selective copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction under mild conditions. This straightforward approach allows the rapid conjugation of a cell-adhesive, alkyne-bearing cyclic RGD peptide motif, enabling subsequent specific attachment of NIH 3T3 fibroblasts, their extensive proliferation and confluent cell sheet formation after 48 h of incubation. The generally applicable strategy presented in this report can be employed for surface functionalization with diverse alkyne-bearing biological moieties via CuAAC or copper-free alkyne-azide cycloaddition protocols, making it a versatile functionalization approach and a promising tool for tissue engineering, biomaterial implant design, and other applications that require surfaces supporting highly specific cell attachment.
- MeSH
- alkyny chemie farmakologie MeSH
- antiinfekční látky chemická syntéza farmakologie MeSH
- azidy chemie farmakologie MeSH
- biokompatibilní materiály chemická syntéza farmakologie MeSH
- buňky NIH 3T3 MeSH
- click chemie MeSH
- cykloadiční reakce MeSH
- katalýza MeSH
- myši MeSH
- oligopeptidy chemie MeSH
- polyhydroxyethylmethakrylát chemie MeSH
- proliferace buněk účinky léků MeSH
- tkáňové inženýrství MeSH
- tkáňové podpůrné struktury * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cyclic pentapeptides containing the amino acid sequence arginine-glycine-aspartic (RGD) have been widely applied to target αvβ3 integrin, which is upregulated in various tumors during tumor-induced angiogenesis. Multimeric cyclic RGD peptides have been reported to be advantageous over monomeric counterparts for angiogenesis imaging. Here, we prepared mono-, di-, and trimeric cyclic arginine-glycine-aspartic-D-phenylalanine-lysine (c (RGDfK)) derivatives by conjugation with the natural chelator fusarinine C (FSC) using click chemistry based on copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC). The αvβ3 binding properties of 68Ga-labeled mono-, di-, and trimeric c(RGDfK) peptides were evaluated in vitro as well as in vivo and compared with the references monomeric [68Ga]GaNODAGA-c(RGDfK) and trimeric [68Ga]GaFSC(suc-c(RGDfK))3. All 68Ga-labeled c(RGDfK) peptides displayed hydrophilicity (logD = -2.96 to -3.80), low protein binding and were stable in phosphate buffered-saline (PBS) and serum up to 2 h. In vitro internalization assays with human melanoma M21 (αvβ3-positive) and M21-L (αvβ3-negative) cell lines showed specific uptake of all derivatives and increased in the series: mono- < di- < trimeric peptide. The highest tumor uptake, tumor-to-background ratios, and image contrast were found for the dimeric [68Ga]GaMAFC(c(RGDfK)aza)2. In conclusion, we developed a novel strategy for direct, straight forward preparation of mono-, di-, and trimeric c(RGDfK) conjugates based on the FSC scaffold. Interestingly, the best αvβ3 imaging properties were found for the dimeric [68Ga]GaMAFC(c(RGDfK)aza)2.
- MeSH
- alkyny chemie MeSH
- azidy chemie MeSH
- click chemie MeSH
- cyklické peptidy chemie farmakokinetika MeSH
- izotopové značení MeSH
- měď chemie MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- PET/CT MeSH
- polymerizace MeSH
- radioizotopy galia chemie MeSH
- siderofory chemie MeSH
- tkáňová distribuce MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The increasing popularity of peptides as promising molecular scaffolds for biomedical applications and as valuable biochemical probes makes new methods allowing for their modification highly desirable. We describe herein an optimized protocol based on a sequence of CuAAC click reactions and selective deprotection steps, which leads to an efficient multi-functionalization of synthetic peptides. The methodology has been successfully applied to the construction of defined heteroglycopeptides and fluorophore-quencher-containing probes for proteases. The developed chemistry thus represents an important addition to the available toolbox of methods enabling efficient postsynthetic modification of peptides. The commercial availability of numerous azide probes further greatly extends the application potential of the described methodology.
