Прогнозирование развития послеоперационной боли у пациентов с поздней стадией остеоартрита коленного сустава по экспрессии генов деградации внеклеточного матрикса, воспаления и апоптоза в крови

About 10–40% of patients with osteoarthritis (OA) are not satisfied with the results of total arthroplasty (TA) of large joints. At the same time, the most common complication associated with the ineffectiveness of TA is postoperative pain (PP).Objective: to identify genes whose expression in the peripheral blood before TA is associated with an increased risk of PP developing. Patients and methods. Before TA, the blood of 50 patients with late-stage knee OA was examined; the control group consisted of 26 healthy individuals. The level of pain was assessed using the visual analog scale (VAS), the BPI short questionnaire, and the WOMAC index; the presence of neuropathic pain was assessed using the DN4 and PainDETECT questionnaires. The development of PP was determined 3 and 6 months after TA. The levels of matrix metalloproteinase protein (MMP) 9 and tissue inhibitor of metalloproteinase (TIMP) 1 were quantified by ELISA. Total RNA isolated from blood was used to determine the expression of caspase 3, MMP9, TIMP1, cathepsins K and S, tumor necrosis factor (TNF) α, interleukin (IL) 1β, and cyclooxygenase 2 genes using a quantitative real-time reverse transcriptase polymerase chain reaction.Results and discussion. PP according to VAS ≥30 mm was noted in 17 patients. Before TA, these patients had significantly increased expression of cathepsins K and S, caspase 3, TIMP1, IL1β, and TNFα genes compared to other patients with OA. ROC analysis revealed a statistically significant relationship between the expression of these genes and the likelihood of developing pain after TA.Conclusion. High expression of genes associated with degradation of the extracellular matrix (catepsins S and K, TIMP1), inflammation (IL1β, TNFα), and apoptosis (caspase 3) can serve as an important biomarker for the development of PP in patients with knee OA. To confirm the value of preoperative gene expression testing in predicting the onset of PP, further studies involving large cohorts of patients are needed.Около 10–40% пациентов с остеоартритом (ОА) не удовлетворены исходом тотального эндопротезирования (ТЭ) крупных суставов. При этом наиболее частым осложнением, ассоциирующимся с неэффективностью ТЭ, является послеоперационная боль (ПБ).Цель исследования – выделить гены, экспрессия которых в периферической крови до ТЭ связана с увеличением риска развития ПБ.Пациенты и методы. Перед ТЭ исследована кровь 50 пациентов с поздней стадией ОА коленных суставов (КС), группу контроля составили 26 здоровых лиц. Уровень боли оценивали по визуальной аналоговой шкале (ВАШ), краткому опроснику BPI и индексу WOMAC, наличие невропатической боли – по опросникам DN4 и PainDETECT. Развитие ПБ определяли через 3 и 6 мес после ТЭ. Проводили количественную оценку уровней белка матриксной металлопротеиназы (MMП) 9 и тканевого ингибитора металлопротеиназы (ТИМП) 1 методом ELISA. Суммарную РНК, выделенную из крови, использовали для определения экспрессии генов каспазы 3, ММП9, TИМП1, катепсинов K и S, фактора некроза опухолей (ФНО)α , интерлейкина (ИЛ) 1β и циклооксигеназы 2 с помощью количественной обратно-транскриптазной полимеразной цепной реакции в реальном времени.Результаты и обсуждение. ПБ по ВАШ ≥30 мм отмечена у 17 больных. Перед ТЭ у этих пациентов была значимо повышена экспрессия генов катепсинов K и S, каспазы 3, TИМП1, ИЛ1β и ФНОα по сравнению с остальными больными ОА. ROC-анализ выявил статистически значимую связь между экспрессией этих генов и вероятностью развития боли после ТЭ.Заключение. Высокая экспрессия генов, связанных с деградацией внеклеточного матрикса (катепсины S и K, TИМП1), воспалением (ИЛ1β , ФНОα ) и апоптозом (каспаза 3), может служить важным биомаркером развития ПБ у пациентов с ОА КС. Для подтверждения ценности предоперационного исследования экспрессии генов для прогноза возникновения ПБ необходимы дальнейшие исследования с участием больших когорт пациентов

Transverse-target-spin asymmetry in exclusive ω\omega-meson electroproduction

Hard exclusive electroproduction of $\omega$ mesons is studied with the HERMES spectrometer at the DESY laboratory by scattering 27.6 GeV positron and electron beams off a transversely polarized hydrogen target. The amplitudes of five azimuthal modulations of the single-spin asymmetry of the cross section with respect to the transverse proton polarization are measured. They are determined in the entire kinematic region as well as for two bins in photon virtuality and momentum transfer to the nucleon. Also, a separation of asymmetry amplitudes into longitudinal and transverse components is done. These results are compared to a phenomenological model that includes the pion pole contribution. Within this model, the data favor a positive $\pi\omega$ transition form factor.Comment: DESY Report 15-14

Bose-Einstein correlations in hadron-pairs from lepto-production on nuclei ranging from hydrogen to xenon

Bose-Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of $^1$H, $^2$H, $^3$He, $^4$He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation function is compared to two different empirical distributions that do not include the Bose-Einstein correlations. One distribution is derived from unlike-sign hadron pairs, and the second is derived from mixing like-sign pairs from different events. The extraction procedure used simulations incorporating the experimental setup in order to correct the results for spectrometer acceptance effects, and was tested using the distribution of unlike-sign hadron pairs. Clear signals of Bose-Einstein correlations for all target nuclei without a significant variation with the nuclear target mass are found. Also, no evidence for a dependence on the invariant mass W of the photon-nucleon system is found when the results are compared to those of previous experiments

Longitudinal double-spin asymmetries in semi-inclusive deep-inelastic scattering of electrons and positrons by protons and deuterons

A comprehensive collection of results on longitudinal double-spin asymmetries is presented for charged pions and kaons produced in semi-inclusive deep-inelastic scattering of electrons and positrons on the proton and deuteron, based on the full HERMES data set. The dependence of the asymmetries on hadron transverse momentum and azimuthal angle extends the sensitivity to the flavor structure of the nucleon beyond the distribution functions accessible in the collinear framework. No strong dependence on those variables is observed. In addition, the hadron charge-difference asymmetry is presented, which under certain model assumptions provides access to the helicity distributions of valence quarks

Flavor decomposition of the sea quark helicity distributions in the nucleon from semi-inclusive deep-inelastic scattering

Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with re-analyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.Comment: 5 pages, 3 figure

Nuclear Polarization of Molecular Hydrogen Recombined on a Non-metallic Surface

The nuclear polarization of $\mathrm{H}_2$ molecules formed by recombination of nuclear polarized H atoms on the surface of a storage cell initially coated with a silicon-based polymer has been measured by using the longitudinal double-spin asymmetry in deep-inelastic positron-proton scattering. The molecules are found to have a substantial nuclear polarization, which is evidence that initially polarized atoms retain their nuclear polarization when absorbed on this type of surfac

Measurement of Angular Distributions and R= sigma_L/sigma_T in Diffractive Electroproduction of rho^0 Mesons

Production and decay angular distributions were extracted from measurements of exclusive electroproduction of the rho^0(770) meson over a range in the virtual photon negative four-momentum squared 0.5< Q^2 <4 GeV^2 and the photon-nucleon invariant mass range 3.8< W <6.5 GeV. The experiment was performed with the HERMES spectrometer, using a longitudinally polarized positron beam and a ^3He gas target internal to the HERA e^{+-} storage ring. The event sample combines rho^0 mesons produced incoherently off individual nucleons and coherently off the nucleus as a whole. The distributions in one production angle and two angles describing the rho^0 -> pi+ pi- decay yielded measurements of eight elements of the spin-density matrix, including one that had not been measured before. The results are consistent with the dominance of helicity-conserving amplitudes and natural parity exchange. The improved precision achieved at 47 GeV, reveals evidence for an energy dependence in the ratio R of the longitudinal to transverse cross sections at constant Q^2.Comment: 15 pages, 15 embedded figures, LaTeX for SVJour(epj) document class Revision: Fig. 15 corrected, recent data added to Figs. 10,12,14,15; minor changes to tex