Синтез та аналгетичні властивості N-(бензил)-2-гідрокси-9-метил-4-оксо-4Н-піридо[1,2-a]піримідин-3-карбоксамідів

Continuing the search for new analgesics among derivatives of azahetarylcaboxylic acids by the reaction of ethyl 2-hydroxy-9-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylate and benzylamines in boiling ethanol the corresponding group of N-(benzyl)-2-hydroxy-9-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxamides has been synthesized. The structure of the compounds obtained has been confirmed by the data of elemental analysis and NMR 1H spectroscopy. It is noted that the signals of aromatic protons of pyrido-pyrimidine nuclei are shifted downfield and generally for a typical AMX spin system. At the same time, the signals of aromatic protons of benzilamide fragments on the contrary are shifted upfield in all cases and focused on very narrow segments of the spectra, thereby undergoing strong distortion. According to the results of the primary pharmacological screening it has been found that using the standard model of “acetic acid writhings” all N-(benzyl)-2-hydroxy-9-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxamides without exception have analgesic properties to a greater or lesser  degree. Practically the same regularities of the benzylamide fragment structure –biological effect relationship as in the case of 4-hydroxyquinolin-2-ones analogues have been found. Based on it the conclusion about bioisosterism of 4-hydroxyquinolin-2-one and 2-hydroxy-9-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine nuclei has been made.Продолжая поиск новых анальгетиков среди производных азагетарилкарбоновых кислот, реакцией этил 2-гидрокси-9-метил-4-оксо-4Н-пиридо[1,2-a]пиримидин-3-карбоксилата с бензиламинами в кипящем этаноле мы осуществили синтез группы соответствующих N-(бензил)-2-гидрокси-9-метил-4-оксо-4Н-пиридо[1,2-a] пиримидин-3-карбоксамидов. Для подтверждения строения полученных веществ использованы элементный анализ и спектроскопия 1Н ЯМР. Отмечено, что сигналы ароматических протонов пиридо-пиримидинового ядра сдвинуты в слабое поле и в целом образуют типичную АМХ спиновую систему. В то же время сигналы ароматических протонов бензиламидных фрагментов наоборот во всех случаях смещены в относительно сильное поле и сосредоточены на очень узких отрезках спектров, за счет чего претерпевают сильное искажение. По результатам первичного фармакологического скрининга установлено, что на стандартной модели уксуснокислых «корчей» все без исключения N-(бензил)-2-гидрокси-9-метил-4-оксо-4Н-пиридо[1,2-a]пиримидин-3-карбоксамиды в той или иной степени обладают анальгетическими свойствами. При этом обнаружены практически те же закономерности влияния строения бензиламидного фрагмента на биологический эффект, что и в случае 4-гидроксихинолин-2-оновых аналогов. На этом основании сделан вывод о биоизостерности 4-гидроксихинолин-2-онового и 2-гидрокси-9-метил-4-оксо-4Н-пиридо[1,2-a]пиримидинового ядер. Продовжуючи пошук нових аналгетиків серед похідних азагетарилкарбонових кислот, реакцією етил 2-гідрокси-9-метил-4-оксо-4Н-піридо[1,2-a]піримідин-3-карбоксилату з бензиламінами у киплячому етанолі ми здійснили синтез групи відповідних N-(бензил)-2-гідрокси-9-метил-4-оксо-4Н-піридо[1,2-a]піримідин-3-карбоксамідів. Для під твердження будови одержаних речовин використані елементний аналіз та спектроскопія 1Н ЯМР. Помічено, що сигнали ароматичних протонів піридо-піримідинового ядра зсунуті у слабке поле і в цілому утворюють типову АМХ спінову систему. В той же час сигнали ароматичних протонів бензиламідних фрагментів навпаки в усіх випадках зміщені у відносно сильне поле та зосереджені на дуже вузьких відрізках спектрів, за рахунок чого піддаються досить сильному спотворенню. За результатами первинного фармакологічного скринінгу встановлено, що на стандартній моделі оцтовокислих «корчів» всі без виключення N-(бензил)-2-гідрокси-9-метил-4-оксо-4Н-піридо[1,2-a]піримідин-3-карбоксаміди в тій чи іншій мірі виявляють аналгетичні властивості. При цьому знайдені практично ті ж закономірності впливу будови бензиламідного фрагмента на біологічний ефект, що й у випадку 4-гідроксихінолін-2-онових аналогів. На підставі цього зроблено висновок щодо біоізостерності 4-гідроксихінолін-2-онового та 2-гідрокси-9-метил-4-оксо-4Н-піридо[1,2-a]піримідинового ядер

Citicoline affects serum angiostatin and neurospecific protein levels in patients with atrial fibrillation and ischemic stroke

Ischemic stroke is considered as one of the most frequent and severe complications of atrial fibrillation. The present study was undertaken to examine whether post-insult treatment with cytidine diphosphate-choline (CDP-choline, or citicoline) affects serum levels of the angiogenesis inhibitor angiostatin and neurospecific proteins as markers of brain damage in patients with cerebral ischemia associated with atrial fibrillation. Thirty-three patients with a diagnosis of acute ischemic stroke received citicoline sodium by intravenous infusions (1,000 mg daily for 14 days) in addition to the standard treatment (basic group). Twenty-five patients with the same pathologies, who received only standard therapy, were enrolled in the study as a control group. Serum content of angiostatin and neurospecific proteins, namely neurofilament heavy subunit (NF-H) and glial fibrillary acidic protein (GFAP), was measured by immunoblotting at the basal level and after the treatment. Citicoline treatment caused significant decreases in serum levels of angiostatin (by 40% vs. basal level, P < 0.05), GFAP (by 61%, P < 0.01), and the NF-H subunit (by 19%, P < 0.05) and had no effect on the serum albumin content. In contrast, there were no statistically significant differences between baseline levels of the studied protein markers and their content after the treatment period in the control group. These findings indicate for the first time that CDP-choline protects both astrocytes and neurons and improves angiogenic capacity through down-regulation of angiostatin in post-ischemic patients with atrial fibrillation after acute ischemic stroke. Further studies are needed to test associations between serum levels of these biomarkers, clinical outcomes, and treatment efficacy of stroke

Identification of the binding site for plasminogen kringle 5 in the α-chain of fibrin(ogen) D-fragment

The interaction of the fifth kringle of Glu-plasminogen with fibrin triggers activation and initiation of fibrinolysis, yet the site on fibrin that binds kringle 5 remains unknown. The aim of our work was to determine an amino acid sequence in the D-fragment of fibrin(ogen) molecule, which is complementary to the lysine-binding site (LBS) in kringle 5. We studied the interaction between kringle 5 of plasminogen with polypeptide chains of the D-fragments of fibrin and cyanogen bromide fragments FCB-2 and t-NDSK and showed that kringle 5 bound specifically to α- and γ-chains of the D-fragment and the α-chain of FCB-2. Tryptic peptides of D-fragment α-chain were obtained, separated by their ability to bind with the immobilized kringle 5, and then all studied peptides were characterized by MALDI-TOF analysis. The critical amino acid residues of the α-chain of D-fragment, which provide its interaction with kringle 5, turned out to be α171Arg and/or α176Lys. The binding site of Glu-plasminogen complementary to the LBS of kringle 5 is located within Аα168Ala−183Lys, a sequence in a weakly structured loop between two supercoils in the α-chain of the D-fragment of the fibrin(ogen) molecule

Haemostasis modulation by calix[4]arene methylenebisphosphonic acid C-145 and its sulfur-containing analogue

C-145 (octasodium salt of calix[4]arene-tetra-methylenebisphosphonic acid) was previously considered as specific anti-сoagulant agent that affects fibrin polymerization and does not notably influence other parameters of coagulation system. C-145S (octasodium salt of thiacalix[4]arene-tetra-methylenebisphosphonic acid) possessing wider hydrophobic hole was expected to be more effective antithrombotic agent than C-145. The aim of present work was to compare the action of both organic compounds on fibrin polymerization, fibrinolysis, platelets and endothelial cells. The change of turbidity during fibrin clot formation induced by APTT-reagent and digestion induced by tPA was estimated. Turbidity study was used for the estimation of polymeric fibrin hydrolysis by plasmin in the presence of thiacalix[4]arene C-145S and calix[4]arene C-145. Effects of thiacalix[4]arene C-145S and calix[4]arene C-145 on the activation of Glu-plasminogen by streptokinase were studied using chromogenic substrate S2251. Platelet aggregation study was performed using aggregometry. Stimulated Ca2+ efflux from endoplasmic reticulum and cytoplasm were determined using specific Ca2+-sensitive probes targeted to endoplasmic reticulum (Mag-Fluo-4) and cytoplasm (FURA-2) by spectrofluorimetry. Both C-145 and C-145S decreased the final turbidity of clot and prolonged clot lysis time in blood plasma in comparison to control value. C-145 was shown to be the more effective fibrinolysis inhibitor when studied in model system of polymerized fibrin desAB. C-145S but not C-145 induced concentration changes of Ca2+ in cytoplasm of resting platelets and significantly inhibited (up to 30%) Ca2+ efflux from endoplasmic reticulum of platelets activated by ADP. Both C-145 and C-145S stimulated the proliferation of endothelial cells of PAE cell line. The effect of C-145S was more prominent. In conclusion, calix[4]arene C 145S proved to be the more potent inhibitor of fibrin polymerization in comparison to C-145, which suggested earlier as anticoagulant agent. C-145S proved to have much more outlined inhibitory action on Ca2+-signaling in platelets and stimulatory effect on endothelial cells proliferation. Thus C-145 remained the most prospective molecular platform for the development of antithrombotic agent

Evidence of d-wave Superconductivity in K_(1-x)Na_xFe_2As_2 (x = 0, 0.1) Single Crystals from Low-Temperature Specific Heat Measurements

From the measurement and analysis of the specific heat of high-quality K_(1-x)Na_xFe_2As_2 single crystals we establish the presence of large T^2 contributions with coefficients alpha_sc ~ 30 mJ/mol K^3 at low-T for both x=0 and 0.1. Together with the observed square root field behavior of the specific heat in the superconducting state both findings evidence d-wave superconductivity on almost all Fermi surface sheets with an average gap amplitude of Delta_0 in the range of 0.4 - 0.8 meV. The derived Delta_0 and the observed T_c agree well with the values calculated within the Eliashberg theory, adopting a spin-fluctuation mediated pairing in the intermediate coupling regime.Comment: 8 pages, 5 figures, field dependence of the specific heat added, slightly changed title, changed sequence of authors, one author added, accepted by Phys. Rev. B Rapid Communication

ОПЫТ РАБОТЫ ГОРОДСКОЙ БОЛЬНИЦЫ СВЯТОГО ВЕЛИКОМУЧЕНИКА ГЕОРГИЯ В УСЛОВИЯХ ЭПИДЕМИИ ГРИППА H1N1 2009 ГОДА

The article presents the experience of conversion multi-disciplinary somatic hospitals in the infectious hospital. In November-December 2009, the hospital carried out 602 care to patients with acute respiratory infections and influenza, 61 had confirmed influenza caused by virus H1N1, of which 43 patients were hospitalized in serious and critical condition and needed resuscitative benefits. Arising from the conversion to ensure that the complexity of medical-diagnostic process and the observance of sanitary-epidemiological rules for patients suffering from the flu, demanded the mobilization of all forces and resources of the hospital, additional equipment, purchases of non-core drugs. We obtained the experience can be a great help in such situations with re-profiling of general somatic hospitals in infection.В связи с превышением эпидемического порога по гриппу и острым респираторным заболеваниям в ноябре 2009 г. в Санкт-Петербурге было осуществлено перепрофилирование многопрофильного стационара СПб ГУЗ «Городская больница Святого Великомученика Георгия» в инфекционный. В ноябре – декабре 2009 г. стационаром осуществлена помощь 602 пациентам с острыми респираторными заболеваниями и гриппом, у 61 был подтвержден грипп, вызванный вирусом H1N1, из них 43 пациента были госпитализированы в тяжелом и крайне тяжелом состоянии и нуждались в проведении реанимационного пособия. Возникшие в связи с перепрофилированием сложности по обеспечению лечебно-диагностического процесса, соблюдению санитарно-эпидемиологических правил в отношении пациентов, больных гриппом, потребовали мобилизации всех сил и ресурсов больницы, дополнительного оснащения, закупки непрофильных лекарственных средств. Полученный опыт может стать хорошим подспорьем в подобных ситуациях при перепрофилировании общесоматических стационаров в инфекционные

Designing the stripe-ordered cuprate phase diagram through uniaxial-stress

The ability to efficiently control charge and spin in the cuprate high-temperature superconductors is crucial for fundamental research and underpins technological development. Here, we explore the tunability of magnetism, superconductivity, and crystal structure in the stripe phase of the cuprate La[Formula: see text]Ba[Formula: see text]CuO[Formula: see text], with [Formula: see text] = 0.115 and 0.135, by employing temperature-dependent (down to 400 mK) muon-spin rotation and AC susceptibility, as well as X-ray scattering experiments under compressive uniaxial stress in the CuO[Formula: see text] plane. A sixfold increase of the three-dimensional (3D) superconducting critical temperature [Formula: see text] and a full recovery of the 3D phase coherence is observed in both samples with the application of extremely low uniaxial stress of [Formula: see text]0.1 GPa. This finding demonstrates the removal of the well-known 1/8-anomaly of cuprates by uniaxial stress. On the other hand, the spin-stripe order temperature as well as the magnetic fraction at 400 mK show only a modest decrease under stress. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. However, strain produces an inhomogeneous suppression of the spin-stripe order at elevated temperatures. Namely, a substantial decrease of the magnetic volume fraction and a full suppression of the low-temperature tetragonal structure is found under stress, which is a necessary condition for the development of the 3D superconducting phase with optimal [Formula: see text]. Our results evidence a remarkable cooperation between the long-range static spin-stripe order and the underlying crystalline order with the three-dimensional fully coherent superconductivity. Overall, these results suggest that the stripe- and the SC order may have a common physical mechanism

Designing the stripe-ordered cuprate phase diagram through uniaxial-stress

The ability to efficiently control charge and spin in the cuprate high-temperature superconductors is crucial for fundamental research and underpins technological development. Here, we explore the tunability of magnetism, superconductivity and crystal structure in the stripe phase of the cuprate La_2-xBa_xCuO_4, with x = 0.115 and 0.135, by employing temperature-dependent (down to 400 mK) muon-spin rotation and AC susceptibility, as well as X-ray scattering experiments under compressive uniaxial stress in the CuO_2 plane. A sixfold increase of the 3-dimensional (3D) superconducting critical temperature T_c and a full recovery of the 3D phase coherence is observed in both samples with the application of extremely low uniaxial stress of 0.1 GPa. This finding demonstrates the removal of the well-known 1/8-anomaly of cuprates by uniaxial stress. On the other hand, the spin-stripe order temperature as well as the magnetic fraction at 400 mK show only a modest decrease under stress. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. However, a substantial decrease of the magnetic volume fraction and a full suppression of the low-temperature tetragonal structure is found at elevated temperatures, which is a necessary condition for the development of the 3D superconducting phase with optimal T_c. Our results evidence a remarkable cooperation between the long-range static spin-stripe order and the underlying crystalline order with the three-dimensional fully coherent superconductivity. Overall, these results suggest that the stripe- and the SC order may have a common physical mechanism.Comment: 11 pages, 5 figures. This work builds on our earlier findings on LBCO, arXiv:2008.01159, and substantially expands i