13 research outputs found
Endovascular treatment of late complications after peripheral vascular bypass grafting - false aneurysm at the distal anastomosis
W artykule opisano przypadek chorego z tętniakiem rzekomym zespolenia dalszego pomostu udowo-podkolanowego, u którego implantowano stent-graft obwodowy w miejscu ubytku naczyniowego.
W pracy zaprezentowano aktualny stan wiedzy na temat etiologii, patomechanizmu powstawania i leczenia
tego powikłania. Przedstawiono również możliwości wykorzystania małoinwazyjnych technik wewnątrznaczyniowych
w leczeniu późnych powikłań chirurgii naczyniowej.A case is presented of a patient with a false aneurysm at the distal anastomosis of the femoropopliteal
bypass who received a peripheral stent-graft to repair vascular defects. Current knowledge on the etiology,
pathomechanisms of development, and treatment of such complications is also presented. Finally,
the potential use of minimally invasive procedures in the treatment of late complications following reconstructive
surgery is discussed
Implementation of selected molecular properties based on the derivatives of the potential energy
Kluczowym osiągnięciem niniejszej pracy jest wyprowadzenie iimplementacja analitycznych gradientów energii w metodach Dressed TDA-TDDFT i Dressed CIS. Konieczną do osiągnięcia głównego celu, a przy tym wartościową samą w sobie składową pracy jest implementacja analitycznych gradientów energii w metodach Kohna-Shama, TDA-TDDFT i CIS. Uzyskany kod został wykorzystany do zaprogramowania optymalizacji geometrii w tych metodach.Ponadto w ramach pracy zaimplementowano obliczenia hesjanu energii w metodzie Hartree-Focka wykorzystując automatyczną generację kodu do uzyskania niezbędnych wyrażeń na drugie pochodne całek jedno- i dwuelektronowych. Wygenerowany kod stanowi podstawę do zaprogramowania hesjanu energii w innych metodach.The crucial result of the thesis is derivation and implementation of the analytic energy gradients in Dressed TDA-TDDFT and Dressed CIS methods. Necessary for the main goal and valuable in itself part of the work is implementation of analytic energy gradients in Kohn-Sham, TDA-TDDFT and CIS methods. The resulting code was used to implement geometry optimization in all the methods.Additionally, energy Hessian in the Hartree-Fock method was implemented, using automatic code generation to render second derivatives of the one- and two-electron integrals. The generated code constitutes a basis for implementing energy Hessian in other methods
Determination of one-electron integrals derivatives on the GPGPU architectures for geometry optimization in the Hartree-Fock method
Korzystając z własności hermitowskich funkcji gaussowskich wyprowadzono równania na pochodne całek jednoelektronowych z wykorzystaniem tych funkcji. Dokonano implementacji otrzymanych wyrażeń w języku Yacas, a następnie wygenerowano odpowiednie funkcje w języku C++. Porównując otrzymane wyniki z wynikami pochodzącymi z implementacji algorytmu Obara-Saiki stwierdzono całkowitą zgodność - co świadczy o poprawności automatycznie wygenerowanych funkcji. Zaplanowano również przeniesienie kodu na procesor GPU.The equations for derivatives of overlap integrals were obtained using properties of Hermite Gaussian functions. The scheme was implemented in Yacas language, then the code in C++ generated. Comparing the results with those from Obara-Saika's algorithm it was found that they are identical, which proves correctness of the newly implemented scheme. Porting to GPU architecture is also planned
„Percutaneous electrode removal in massive lead-related infective endocarditis using the Angiovac system”
Jest to opis przypadku, u którego zastosowano system AngioVAC do usunięcia dużych wegetacji z elektrod ICD, a następnie wykonano przezskórną ekstrakcję systemu. Było to pierwsze zastosowanie systemu angioVAC w Polsce. To urządzenie pozwoliło uniknąć operacji na otwartym sercu. Jest to punkt do rozpoczęcia dyskusji na temat rutynowego stosowania tego sprzętu u pacjentów z infekcyjnym zapaleniem wsierdzia związanym z elektrodami. Odległe wyniki u pacjentów leczonych tym urządzeniem są znacznie lepsze.This is a case report of a patient in whom AngioVAC was used for the removal of large vegetations from the endocardial lead. It was the first application of angioVAC system in Poland. This device allowed to avoid open heart surgery. This is a point to start a discussion on the use of this equipment routinely in patients with lead-related infective endocarditis. Long-term results in patients treated with this device are significantly better
1,2-Hydrogenation and Transhydrogenation Catalyzed by 3-Ketosteroid Δ1-Dehydrogenase from Sterolibacterium denitrificans—Kinetics, Isotope Labelling and QM:MM Modelling Studies
Bacteria and fungi that are able to metabolize steroids express 3-ketosteroid-Δ1-dehydrogenases (KstDs). KstDs such as AcmB form Sterolibacterium denitrificans Chol-1 catalyze the enantioselective 1α,2β-dehydrogenation of steroids to their desaturated analogues, e.g., the formation of 1,4-androstadiene-3,17-dione (ADD) from 4-androsten-3,17-dione (AD). The reaction catalyzed by KstD can be reversed if the appropriate electron donor, such as benzyl viologen radical cation, is present. Furthermore, KstDs can also catalyze transhydrogenation, which is the transfer of H atoms between 3-ketosteroids and 1-dehydrosteroids. In this paper, we showed that AcmB exhibits lower pH optima for hydrogenation and dehydrogenation by 3.5–4 pH units than those observed for KstD from Nocardia corallina. We confirmed the enantiospecificity of 1α,2β-hydrogenation and 1α,2β-transhydrogenation catalyzed by AcmB and showed that, under acidic pH conditions, deuterons are introduced not only at 2β but also at the 1α position. We observed a higher degree of H/D exchange at Y363, which activates the C2-H bond, compared to that at FAD, which is responsible for redox at the C1 position. Furthermore, for the first time, we observed the introduction of the third deuteron into the steroid core. This effect was explained through a combination of LC-MS experiments and QM:MM modelling, and we attribute it to a decrease in the enantioselectivity of C2-H activation upon the deuteration of the 2β position. The increase in the activation barrier resulting from isotopic substitution increases the chance of the formation of d3-substituted 3-ketosteroids. Finally, we demonstrate a method for the synthesis of 3-ketosteroids chirally deuterated at 1α,2β positions, obtaining 1α,2β-d2-4-androsten-3,17-dione with a 51% yield (8.61 mg)
Mining anion–aromatic interactions in the Protein Data Bank
Mutual positioning and non-covalent interactions in anion–aromatic motifs are crucial for functional performance of biological systems. In this context, regular, comprehensive Protein Data Bank (PDB) screening that involves various scientific points of view and individual critical analysis is of utmost importance. Analysis of anions in spheres with radii of 5 Å around all 5- and 6-membered aromatic rings allowed us to distinguish 555 259 unique anion–aromatic motifs, including 92 660 structures out of the 171 588 structural files in the PDB. The use of a scarcely exploited (x, h) coordinate system led to (i) identification of three separate areas of motif accumulation: A – over the ring, B – over the ring-substituent bonds, and C – roughly in the plane of the aromatic ring, and (ii) unprecedented simultaneous comparative description of various anion–aromatic motifs located in these areas. Of the various residues considered, i.e. aminoacids, nucleotides, and ligands, the latter two exhibited a considerable tendency to locate in region Avia archetypal anion–π contacts. The applied model not only enabled statistical quantitative analysis of space around the ring, but also enabled discussion of local intermolecular arrangements, as well as detailed sequence and secondary structure analysis, e.g. anion–π interactions in the GNRA tetraloop in RNA and protein helical structures. As a purely practical issue of this work, the new code source for the PDB research was produced, tested and made freely available at https://github.com/chemiczny/PDB_supramolecular_search
Universal capability of 3-ketosteroid Δ1-dehydrogenases to catalyze Δ1-dehydrogenation of C17-substituted steroids
Background: 3-Ketosteroid Δ1-dehydrogenases (KSTDs) are the enzymes involved in microbial cholesterol degradation and modification of steroids. They catalyze dehydrogenation between C1 and C2 atoms in ring A of the polycyclic structure of 3-ketosteroids. KSTDs substrate spectrum is broad, even though most of them prefer steroids with small substituents at the C17 atom. The investigation of the KSTD’s substrate specificity is hindered by the poor solubility of the hydrophobic steroids in aqueous solutions. In this paper, we used 2-hydroxpropyl-β-cyclodextrin (HBC) as a solubilizing agent in a study of the KSTDs steady-state kinetics and demonstrated that substrate bioavailability has a pivotal impact on enzyme specificity. Results: Molecular dynamics simulations on KSTD1 from Rhodococcus erythropolis indicated no difference in ΔGbind between the native substrate, androst-4-en-3,17-dione (AD; − 8.02 kcal/mol), and more complex steroids such as cholest-4-en-3-one (− 8.40 kcal/mol) or diosgenone (− 6.17 kcal/mol). No structural obstacle for binding of the extended substrates was also observed. Following this observation, our kinetic studies conducted in the presence of HBC confirmed KSTD1 activity towards both types of steroids. We have compared the substrate specificity of KSTD1 to the other enzyme known for its activity with cholest-4-en-3-one, KSTD from Sterolibacterium denitrificans (AcmB). The addition of solubilizing agent caused AcmB to exhibit a higher affinity to cholest-4-en-3-one (Ping-Pong bi bi KmA = 23.7 μM) than to AD (KmA = 529.2 μM), a supposedly native substrate of the enzyme. Moreover, we have isolated AcmB isoenzyme (AcmB2) and showed that conversion of AD and cholest-4-en-3-one proceeds at a similar rate. We demonstrated also that the apparent specificity constant of AcmB for cholest-4-en-3-one (kcat/KmA = 9.25∙106 M−1 s−1) is almost 20 times higher than measured for KSTD1 (kcat/KmA = 4.71∙105 M−1 s−1). Conclusions: We confirmed the existence of AcmB preference for a substrate with an undegraded isooctyl chain. However, we showed that KSTD1 which was reported to be inactive with such substrates can catalyze the reaction if the solubility problem is addressed
Quinolinesulfonamides of aryloxy-/arylthio-ethyl piperidines : influence of an arylether fragment on 5-HT1A/5-HT7 receptor selectivity
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Radial artery spasms - angiographic morphology, risk factors and management.
INTRODUCTION: Radial artery is the preferred access for coronary interventions. However, the procedure is sometimes interrupted by a spasm which causes pain, prolongs the procedure, and can force the access crossover. AIM: To observe factors contributing to a symptomatic radial artery spasm. MATERIAL AND METHODS: In this prospective study, we present results of 103 consecutive patients regarding radial artery spasm and angiographic image of the punctured artery. Angiography of the radial artery was performed in 70 (68.0%) patients. Potential risk factors for radial artery spasm were evaluated. RESULTS: The overall incidence of the radial artery spasm was high - 25 (24.3%). Signs of spasm were present in 37.1% of radial artery angiographies before the procedure and 60.1% after, however, it did not always indicate a symptomatic spasm. Risk factors related to radial artery spasm included female sex (OR = 2.94, p = 0.02), failure of the first puncture attempt (OR = 3.12, p = 0.014) and use of non-hydrophilic sheath (OR = 9.56, p = 0.036). Radial artery narrowing at the tip of the sheath was also a risk factor for spasm (p = 0.022). No spasms were observed after hydrophilic sheath application (n = 13). The administration of a radial cocktail was not observed to significantly decrease the spasm odds. CONCLUSIONS: Risk factors for radial artery spasm include female sex and multiple puncture attempts. Hydrophilic sheath coating protects against radial artery spasm. Overall signs of a spasm in the angiography are common and do not imply a symptomatic spasm, which can be predicted by a tight narrowing at the tip of the sheath