Скрининг экстрактов лекарственных растений на ингибирующую активность ксантиноксидазы

Objectives. The study aimed to test the ethanol extracts of ten medicinal plants for xanthine oxidase inhibitory activity.Methods. The degree of xanthine oxidase inhibitory activity was determined by measuring the absorbance spectrophotometrically at 290 nm, which is associated with uric acid formation. The selected medicinal plants included Piper lolot C.DC. (Piperaceae), Pandanus amaryllifolius R.(Pandanaceae), Brassica juncea L. (Brassicaceae), Piper betle L. (Piperaceae), Perilla frutescens L. (Lamiaceae), Anacardium occidentale L. (Anacardiaceae), Polygonum barbatum L. (Polygonaceae), Artocarpus Altilis P. (Moraceae), Vitex negundo L. (Verbenaceae), Annona squamosal L. (Annonaceae), which were selected based on folk medicine.Results. The results showed that the Piper betle L. has a strong ability to inhibit xanthine oxidase with an IC50 value of up to 1.18 μg/mL, compared to allopurinol 1.57 μg/mL. Different parts of Piper betle L. were compared and the leaves of Piper betle L. showed the best value for xanthine oxidase inhibitory and antioxidant activity.Conclusions. Piper betle L. showed the best potential for inhibition of xanthine oxidase among ten medicinal plants. Piper betle L. leaf extract showed strong xanthine oxidase inhibitory and antioxidant activity, compared to the whole plant, and the stem extract, which promises to be applied in the treatment of gout.Цели. Исследование было направлено на проверку этанольных экстрактов десяти лекарственных растений на ингибиторную активность ксантиноксид азы.Методы. Степень ингибирующей активности ксантиноксидазы определяли путем спектрофотометрического измерения поглощения при 290 нм, вызываемого образованием мочевой кислоты. В состав отобранных лекарственных растений вошли перец-лолот (Piperaceae), пандан (Pandanaceae), горчица сарептская (Brassicaceae), бетель (Piperaceae), перилла обыкновенная (Lamiaceae), кешью (Anacardiaceae), конопля (Polygonaceae), хлебное дерево (Moraceae), прутняк китайский (Verbenaceae), сахарное яблоко (Annonaceae), отобранные на основе их применения в народ ной медицине.Результаты. Результаты показали, что бетель обладает сильной способностью ингибировать ксантиноксидазу со значением IC50 до 1.18 мкг/мл по сравнению с аллопуринолом 1.57 мкг/мл. Были проведены сравнения различных частей бетеля, и листья бетеля показали наилучшие показатели ингибирования ксантиноксидазы и антиоксидантной активности.Выводы. Бетель показал лучший потенциал ингибирования ксантиноксидазы среди десяти лекарственных растений. Экстракт листьев бетеля показал сильное подавление ксантиноксидазы и антиоксидантную активность по сравнению с целым растением и экстрактом стебля, которые применяются при лечении подагры

Оптимизация общего содержания флавоноидов в спиртовом экстракте Persicaria pulchra (Bl.) Soják для ингибирования фермента α-глюкозидазы

Objectives. There has been a rapid increase in the number of diabetic patients since the past few decades in developed and developing countries. This rapid increase is accompanied by alarming costs of treatment. α-Glucosidase inhibitors are one of the most effective drugs employed for the reduction of postprandial hyperglycemia to manage Type 2 diabetes mellitus. Additionally, flavonoids, a group of natural substances, which are widely distributed in plants and possess variable phenolic structures, exhibit outstanding hypoglycemic activity and are considered as potential α-glucosidase inhibitors. In Vietnam, Persicaria pulchra (Bl.) Soják (P. pulchra) is employed in traditional medications. It possesses high flavonoid contents and its anti-diabetes ability has been hypothesized, although it has attracted less attention for investigation. Hence, the aim of this study is to optimize the condition of the P. pulchra extract to obtain the highest total flavonoid content and measure the bioactivities of P. pulchra, such as the anti-α-glucosidase and antioxidant activities.Methods. The effects of the extracting conditions, including the temperature, extraction time, liquid-to-solid ratio (LSR), and ethanol (C2H5OH) concentration, on the total flavonoid content are investigated via experiments and analyzed by the response surface methodology (RSM). Concurrently, the optimal extraction also determines the anti-α-glucosidase and antioxidant activities.Results. The optimal extraction condition for the highest flavonoid content (530 mg quercetin/g) is determined in 60 min, at 53°C, with LSR of 9.46 g/g and C2H5OH concentration of 62%. Moreover, the optimal plant extract exhibits good α-glucosidase inhibition with a half-maximal inhibitory concentration (IC50) of 22.67 mg/mL, compared to the positive control (acarbose −7.77 g/mL). Additionally, P. pulchra is proposed to be a potential antioxidant with an IC50 of ~12.68 µg/mL.Conclusions. The study confirmed the optimal extraction condition of P. pulchra that will obtain the highest total flavonoid content and revealed the potentials of P. pulchra in α-glucosidase inhibition and antioxidation.Цели. В последние десятилетия в развитых и развивающихся странах наблюдается быстрый рост числа больных диабетом, который сопровождается ростом стоимости лечения. Ингибиторы α-глюкозидазы являются одним из наиболее эффективных препаратов, применяемых для снижения постпрандиальной гипергликемии при лечении сахарного диабета 2 типа. Кроме того, флавоноиды, группа природных веществ, широко распространенных в растениях и содержащих различные производные фенола, проявляют значительную гипогликемическую активность и могут служить потенциальными ингибиторами α-глюкозидазы. Во Вьетнаме Persicaria pulchra (Bl.) Soják (P. pulchra) используется в народной медицине. Он обладает высоким содержанием флавоноидов и, предположительно, противодиабетическими свойствами, хотя исследован мало. Таким образом, целью настоящего исследования является оптимизация экстрагирования P. pulchra для получения наиболее высокого общего содержания флавоноидов, а также определение его биологической активности – анти-α-глюкозидазной и антиоксидантной. Методы. Экспериментально исследовано влияние условий экстрагирования, а именно температуры, времени экстракции, соотношения жидкость : твердое вещество и концентрации этанола, на общее содержание флавоноидов с помощью методологии анализа поверхности отклика. Показано, что оптимальные условия экстракции определяют анти-α-глюкозидазную и антиоксидантную активность.Результаты. Найдены оптимальные условия экстракции для получения максимального содержания флавоноидов (530 мг кверцетина/г): время экстракции 60 мин, температура 53 °С, отношение жидкость : твердое вещество 9.46 г/г и концентрация этанола 62%. Растительный экстракт, полученный в оптимальных условиях, проявляет хорошее ингибирование α-глюкозидазы с концентрацией полумаксимального ингибирования (IC50) 22.67 мг/мл по сравнению с положительным контролем (акарбоза – 7.77 г/мл). Выводы. Исследование выявило оптимальные условия экстракции P. pulchra, позволяющие получить наиболее высокое общее содержание флавоноидов, и подтвердило перспективы применения P. pulchra для ингибировании α-глюкозидазы и антиоксидантного окисления

Simulated nuclear spin-lattice relaxation in Heisenberg ferrimagnets: Indirect observation of quadratic dispersion relations

In response to recent proton spin relaxation-time measurements on NiCu(pba)(H$_2$O)$_3$$\cdot$2H$_2$O with ${pba}=1,3{-propylenebis(oxamato)}$, which is an excellent one-dimensional ferrimagnetic Heisenberg model system of spin-$(1,{1/2})$, we study the Raman relaxation process in spin-$(S,s)$ quantum ferrimagnets on the assumption of predominantly dipolar hyperfine interactions between protons and magnetic ions. The relaxation time $T_1$ is formulated within the spin-wave theory and is estimated as a function of temperature and an applied field $H$ by a quantum Monte Carlo method. The low-temperature behavior of the relaxation rate $T_1^{-1}$ qualitatively varies with $(S,s)$, while $T_1^{-1}$ is almost proportional to $H^{-1/2}$ due to the characteristic dispersion relations.Comment: 5 pages, 3 figures embedded, to appear in Phys. Rev. B Rapid Commu

The CD28-Transmembrane Domain Mediates Chimeric Antigen Receptor Heterodimerization With CD28.

Anti-CD19 chimeric antigen receptor (CD19-CAR)-engineered T cells are approved therapeutics for malignancies. The impact of the hinge domain (HD) and the transmembrane domain (TMD) between the extracellular antigen-targeting CARs and the intracellular signaling modalities of CARs has not been systemically studied. In this study, a series of 19-CARs differing only by their HD (CD8, CD28, or IgG <sub>4</sub> ) and TMD (CD8 or CD28) was generated. CARs containing a CD28-TMD, but not a CD8-TMD, formed heterodimers with the endogenous CD28 in human T cells, as shown by co-immunoprecipitation and CAR-dependent proliferation of anti-CD28 stimulation. This dimerization was dependent on polar amino acids in the CD28-TMD and was more efficient with CARs containing CD28 or CD8 HD than IgG <sub>4</sub> -HD. The CD28-CAR heterodimers did not respond to CD80 and CD86 stimulation but had a significantly reduced CD28 cell-surface expression. These data unveiled a fundamental difference between CD28-TMD and CD8-TMD and indicated that CD28-TMD can modulate CAR T-cell activities by engaging endogenous partners

QED3 theory of underdoped high temperature superconductors

Low-energy theory of d-wave quasiparticles coupled to fluctuating vortex loops that describes the loss of phase coherence in a two dimensional d-wave superconductor at T=0 is derived. The theory has the form of 2+1 dimensional quantum electrodynamics (QED3), and is proposed as an effective description of the T=0 superconductor-insulator transition in underdoped cuprates. The coupling constant ("charge") in this theory is proportional to the dual order parameter of the XY model, which is assumed to be describing the quantum fluctuations of the phase of the superconducting order parameter. The principal result is that the destruction of phase coherence in d-wave superconductors typically, and immediately, leads to antiferromagnetism. The transition can be understood in terms of the spontaneous breaking of an approximate "chiral" SU(2) symmetry, which may be discerned at low enough energies in the standard d-wave superconductor. The mechanism of the symmetry breaking is analogous to the dynamical mass generation in the QED3, with the "mass" here being proportional to staggered magnetization. Other insulating phases that break chiral symmetry include the translationally invariant "d+ip" and "d+is" insulators, and various one dimensional charge-density and spin-density waves. The theory offers an explanation for the rounded d-wave-like dispersion seen in ARPES experiments on Ca2CuO2Cl2 (F. Ronning et. al., Science 282, 2067 (1998)).Comment: Revtex, 20 pages, 5 figures; this is a much extended follow-up to the Phys. Rev. Lett. vol.88, 047006 (2002) (cond-mat/0110188); improved presentation, many additional explanations, comments, and references added, sec. IV rewritten. Final version, to appear in Phys. Rev.

Grain Surface Models and Data for Astrochemistry

AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions

Cost effectiveness of a 1-hour high-sensitivity troponin-T protocol: an analysis of the RAPID-TnT trial

Background: To understand the economic impact of an accelerated 0/1-hour high-sensitivity troponin-T (hs-cTnT) protocol. Objective: To conduct a patient-level economic analysis of the RAPID-TnT randomised trial in patients presenting with suspected acute coronary syndrome (ACS). Methods: An economic evaluation was conducted with 3265 patients randomised to either the 0/1-hour hs-cTnT protocol (n = 1634) or the conventional 0/3-hour standard-of-care protocol (n = 1631) with costs reported in Australian dollars. The primary clinical outcome was all-cause mortality or new/recurrent myocardial infarction. Results: Over 12-months, mean per patient costs were numerically higher in the 0/1-hour arm compared to the conventional 0/3-hour arm (by $472.49/patient, 95$-1,380.15 to $2,325.13, P = 0.617) with no statistically significant difference in primary outcome (0/1-hour: 62/1634 [3.8$891.22/patient, 95 %CI: $-96.07 to 1,878.50, P = 0.077). Restricting the analysis to patients with hs-cTnT concentrations ≤ 29 ng/L, mean per patient cost remained numerically higher in the 0/1-hour arm (by$152.44/patient, 95 %CI:$-1,793.11 to$2,097.99, P = 0.988), whilst the reduction in ED LOS was more pronounced (by 0.70 h/patient, 95 %CI: 0.45–0.95, P < 0.001). Conclusions: There were no differences in resource utilization between the 0/1-hour hs-cTnT protocol versus the conventional 0/3-hour protocol for the assessment of suspected ACS, despite improved initial ED efficiency. Further refinements in strategies to improve clinical outcomes and subsequent management efficiency are needed.Ming-yu Anthony Chuang Emmanuel S. Gnanamanickam, Jonathan Karnon, Kristina Lambrakis, Matthew Horsfall, Andrew Blyth ... et al

Red blood cell transfusion practices for patients with cervical cancer undergoing radiotherapy

Biological, physical and clinical aspects of cancer treatment with ionising radiatio

Low Q^2 Jet Production at HERA and Virtual Photon Structure

The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure