279 research outputs found

    Study of cultural properties of canine enteric coronavirus isolate in different cell cultures

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    The etiology of the diseases affecting gastrointestinal tractofdogs is variable. The second most important enteric viral pathogen in the world after parvovirus is coronavirus (CCoV). Vast studies by scientists from different countries evidence the ubiquitous spread of coronavirus infection in dog populations. In this regard, the prevention of this disease is still an acute problem; firstly this means the development of effective vaccines, which can provide are liable protection from the infection. The aim of this work was to study the CCoV isolate cultural properties, the selection of cell cultures most suitable for its reproduction and optimization of virus cultivation parameters in sensitive cell lines. TheCCoV isolate recovered from the pathological material of a dead puppy with enteritis symptoms was used in the study. Seven continuousandtwoprimarytrypsinizedcellculturesweretestedduringthestudyanditwasestablishedthat the most sensitive cell culture for the reproduction of this isolate was continuous Crandell-Rees Feline Kidney Cells (CRFK) in which atypical cytopathic effect was notedon Day 2 of the cultivation. Virus infectivity titer in this culture was 3.58 ± 0.14 lgTCID50/cm3 . It was established that such cell linesas fel in espleen cells (FS) and primary trypsinized kitten spleen cells (KS) are also sensitive to the CCoV isolate but less than CRFK cells. Effect of such parameters as multiplicity of infection, cultivation time, inoculation technique, adsorption period and cell lineag eon coronavirus growth rate was studiedfor some selected cell cultures. It was concluded that CRFK and FS cells can be used for the propagation of viral material to develop diagnostic tools and vaccines against canineenteric coronavirus

    Imaging interactions between the immune and cardiovascular systems in vivo by multiphoton microscopy

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    Several recent studies in immunology have used multiphoton laser-scanning microscopy to visualise the induction of an immune response in real time in vivo. These experiments are illuminating the cellular and molecular interactions involved in the induction, maintenance and regulation of immune responses. Similar approaches are being applied in cardiovascular research where there is an increasing body of evidence to support a significant role for the adaptive immune system in vascular disease. As such, we have begun to dissect the role of T lymphocytes in atherosclerosis in real time in vivo. Here, we provide step-by-step guides to the various stages involved in visualising the migration of T cells within a lymph node and their infiltration into inflamed tissues such as atherosclerotic arteries. These methods provide an insight into the mechanisms involved in the activation and function of immune cells in vivo

    Phase changes of the Be/X-ray binary X Persei

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    We present high resolution optical spectroscopy and V band photometry obtained during the period 1987-2001 for the Be star X Persei/HD 24534, the counterpart to the X-ray pulsar 4U 0352+30. We find that throughout this interval X Per is highly active, with significant photometric and spectroscopic variability. We identify one episode of complete disc loss during this period (1988 May-1989 June), characterised by significant ΔV=0.6 mag optical fading and the presence of purely photospheric Hα and He I 6678 Å lines. Two further episodes of pronounced optical fading which did not result in the complete dispersal of the circumstellar disc were also identified (1994 October-1995 October and 1999 November-present). The emission line profiles of both Hα and He I 6678 Å also show significant variability. Cyclic changes in the strength of the peaks in both emission lines are observed, with periods ranging from 0.6-2 yrs - we attribute these to the presence of a one armed density wave in the inner circumstellar disc. Additional structure at large projected velocities is also present in the He I line - suggesting the presence of a significant density enhancement in the disc near the stellar surface (the "double disc'' of Tarasov & Roche). The evolution of the outer edge of the Hα emitting region of the circumstellar disc is followed during disc formation, and is found to increase rather slowly. This observation, combined with the presence of the one armed density wave and the rate of disc formation and loss all provide strong evidence for the hypothesis that the circumstellar disc of X Per is a viscous decretion disc, with angular momentum being supplied by an as yet unknown physical mechanism near the stellar surface

    Stable topological textures in a classical 2D Heisenberg model

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    We show that stable localized topological soliton textures (skyrmions) with π2\pi_2 topological charge ν1\nu \geq 1 exist in a classical 2D Heisenberg model of a ferromagnet with uniaxial anisotropy. For this model the soliton exist only if the number of bound magnons exceeds some threshold value NcrN_{\rm cr} depending on ν\nu and the effective anisotropy constant KeffK_{\rm eff}. We define soliton phase diagram as the dependence of threshold energies and bound magnons number on anisotropy constant. The phase boundary lines are monotonous for both ν=1\nu=1 and ν>2\nu >2, while the solitons with ν=2\nu=2 reveal peculiar nonmonotonous behavior, determining the transition regime from low to high topological charges. In particular, the soliton energy per topological charge (topological energy density) achieves a minimum neither for ν=1\nu=1 nor high charges, but rather for intermediate values ν=2\nu=2 or ν=3\nu=3.Comment: 8 pages, 4 figure

    Tomographic Separation of Composite Spectra. VIII. The Physical Properties of the Massive Compact Binary in the Triple Star System HD 36486 (delta Orionis A)

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    Double-lined spectroscopic orbital elements have recently been found for the central binary in the massive triple, delta Orionis A based on radial velocities from cross-correlation techniques applied to IUE high dispersion spectra and He I 6678 spectra obtained at Kitt Peak. The primary and secondary velocity amplitudes were found to be 94.9 +/- 0.6 km/s and 186 +/- 9 km/s respectively. Tomographic reconstructions of the primary and secondary stars' spectra confirm the O9.5 II classification of the primary and indicate a B0.5 III type for the secondary. The widths of the UV cross-correlation functions are used to estimate the projected rotational velocities, Vsin i = 157 +/- 6 km/s and 138 +/- 16 km/s for the primary and secondary, respectively implying that both stars rotate faster than their orbital motion. We used the spectroscopic results to make a constrained fit of the Hipparcos light curve of this eclipsing binary, and the model fits limit the inclination to the range between 67 and 77 degrees. The i = 67 degrees solution, which corresponds to a near Roche-filling configuration, results in a primary mass of 11.2 solar masses and a secondary mass of 5.6 solar masses, both of which are substantially below the expected masses for stars of their luminosity. This binary may have experienced a mass ratio reversal caused by Case A Roche lobe overflow, or the system may have suffered extensive mass loss through a binary interaction, perhaps during a common envelope phase, in which most of the primary's mass was lost from the system rather than transferred to the secondary.Comment: 27 pages, 15 figures in press, the Astrophysical Journal, February 1, 200

    Germline-restricted chromosome (GRC) is widespread among songbirds

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    An unusual supernumerary chromosome has been reported for two related avian species, the zebra and Bengalese finches. This large, germline-restricted chromosome (GRC) is eliminated from somatic cells and spermatids and transmitted via oocytes only. Its origin, distribution among avian lineages, and function were mostly unknown so far. Using immunolocalization of key meiotic proteins, we found that GRCs of varying size and genetic content are present in all 16 songbird species investigated and absent from germline genomes of all eight examined bird species from other avian orders. Results of fluorescent in situ hybridization of microdissected GRC probes and their sequencing indicate that GRCs show little homology between songbird species and contain a variety of repetitive elements and unique sequences with paralogs in the somatic genome. Our data suggest that the GRC evolved in the common ancestor of all songbirds and underwent significant changes in the extant descendant lineages

    Depletion of B2 but Not B1a B Cells in BAFF Receptor-Deficient ApoE−/− Mice Attenuates Atherosclerosis by Potently Ameliorating Arterial Inflammation

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    We have recently identified conventional B2 cells as atherogenic and B1a cells as atheroprotective in hypercholesterolemic ApoE−/− mice. Here, we examined the development of atherosclerosis in BAFF-R deficient ApoE−/− mice because B2 cells but not B1a cells are selectively depleted in BAFF-R deficient mice. We fed BAFF-R−/− ApoE−/− (BaffR.ApoE DKO) and BAFF-R+/+ApoE−/− (ApoE KO) mice a high fat diet (HFD) for 8-weeks. B2 cells were significantly reduced by 82%, 81%, 94%, 72% in blood, peritoneal fluid, spleen and peripheral lymph nodes respectively; while B1a cells and non-B lymphocytes were unaffected. Aortic atherosclerotic lesions assessed by oil red-O stained-lipid accumulation and CD68+ macrophage accumulation were decreased by 44% and 50% respectively. B cells were absent in atherosclerotic lesions of BaffR.ApoE DKO mice as were IgG1 and IgG2a immunoglobulins produced by B2 cells, despite low but measurable numbers of B2 cells and IgG1 and IgG2a immunoglobulin concentrations in plasma. Plasma IgM and IgM deposits in atherosclerotic lesions were also reduced. BAFF-R deficiency in ApoE−/− mice was also associated with a reduced expression of VCAM-1 and fewer macrophages, dendritic cells, CD4+ and CD8+ T cell infiltrates and PCNA+ cells in lesions. The expression of proinflammatory cytokines, TNF-α, IL1-β and proinflammatory chemokine MCP-1 was also reduced. Body weight and plasma cholesterols were unaffected in BaffR.ApoE DKO mice. Our data indicate that B2 cells are important contributors to the development of atherosclerosis and that targeting the BAFF-R to specifically reduce atherogenic B2 cell numbers while preserving atheroprotective B1a cell numbers may be a potential therapeutic strategy to reduce atherosclerosis by potently reducing arterial inflammation

    Determinants of COVID-19 vaccine acceptance in a high infection-rate country: a cross-sectional study in Russia

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    Background: COVID-19 vaccine development is proceeding at an unprecedented pace. Once COVID-19 vaccines become widely available, it will be necessary to maximize public vaccine acceptance and coverage.Objective: This research aimed to analyze the predictors of COVID-19 vaccine acceptance in Russia.Methods: A cross-sectional online survey was conducted among Russian adults from September 26th to November 9th, 2020. Predictors of the intent to take up COVID-19 vaccination were explored using logistic regression.Results: Out of 876 participants, 365 (41.7%) would be willing to receive the vaccine if it became available. Acceptance increased for a vaccine with verified safety and effectiveness (63.2%). Intention to receive the COVID-19 vaccine was relatively higher among males (aOR=2.37, 95% CI 1.41-4.00), people with lower monthly income (aOR=2.94, 95%CI 1.32-6.57), and with positive trust in the healthcare system (aOR=2.73, 95% CI 1.76-4.24). The Russian people were more likely to accept the COVID-19 vaccine if they believed that the vaccine reduces the risk of virus infection (aOR=8.80, 95%CI 5.21-14.87) or relieves the complications of the disease (aOR=10.46, 95%CI 6.09-17.96). Other barriers such as being unconcerned about side-effects (aOR=1.65, 95%CI 1.03-2.65) and the effectiveness and safety of the vaccination (aOR=2.55, 95%CI 1.60-4.08), also affected acceptance.Conclusions: The study showed the usefulness of the health belief model constructs in understanding the COVID-19 vaccination acceptance rate in the Russian population. This rate was influenced by sociodemographic and health-related characteristics, and health beliefs. These findings might help guide future efforts for policymakers and stakeholders to improve vaccination rates by enhancing trust in the healthcare system

    Comparative evaluation of results of duplex ultrasound angiography in case of replacement arthroplasty of large joints in the early postoperative period

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    Research objective: to ascertain and compare frequency and nature of venous system pathology with the use of ultrasound scanning of lower limbs on 3rd-5th and 1st days after replacement arthroplasty of large joints. Material and methods. The results of ultrasound scanning, that had been conducted on 14 635 patients after replacement arthroplasty of large joints, were analyzed. All the patients were divided into 2 groups: 7 509 patients were performed the ultrasound scanning of their lower limb veins on 3rd -5th day, 7126 patients - on the 1st day of the postoperative period. Results. In the postoperative period, acute thrombosis of the lower limb veins was diagnosed in 952 patients (12.4%) who were conducted the ultrasound scanning on 3rd-5th day, in the second group - in 570 cases (7.9%), p<0.05. In the first group, proximal thrombosis was diagnosed in 89 patients (1.2%), and distal thrombosis - in 863 patients (11.4%). In the second group, there were registered 101 cases (1.4%) of acute proximal deep venous thrombosis, and 469 (6.6%) cases of distal thrombosis. Provided that the proportion of surgical interventions in the lower limb veins has significantly decreased from 0.5% to 0.1 %. Number of factors of thromboembolia of pulmonary artery has decreased by 3 times. Change of examination date in the postoperative period for an earlier one in the second group, and introduction of such diagnostic methods of deep vein lumen as the snowstorm pattern (patent for an invention No. 2547072 in the Russian Federation dated 2015) have enabled reference of patients to a high-risk group (2.6%), correction of the postoperative pharmaceutical treatment, and, thereby, stop of pathological process manifestation. Conclusion. Earlier detection of phlebothrombosis allowed correcting therapeutic approaches to patients to reduce the number of operations on vessels, improve results of treatment - replacement arthroplasty, reduce duration of hospital stay, reduce material and financial burden of a hospital, and increase quality of patient’s life.Цель исследования: выявить и сравнить частоту и характер патологии венозной системы при ультразвуковом исследовании нижних конечностей на 3-5 и 1-2-е сутки после эндопротезирования крупных суставов. Материалы и методы: проведен анализ ультразвукового исследования у 14 635 больных после эндопротезирования крупных суставов. Пациенты разделены на 2 группы: 7 509 пациентам ультразвуковое исследование вен нижних конечностей проводилось на 3-5 сутки, 7126 пациентов - на 1-е сутки послеоперационного периода. Результаты. В послеоперационном периоде, острый тромбоз вен нижних конечностей при ультразвуковом исследовании, проводимом на 3-5 сутки - определен у 952 пациентов (12,4%), во второй группе - в 570 случаях (7,9%), р<0.05. Проксимальный тромбоз в первой группе выявлен у 89 пациентов (1,2%), дистальный тромбоз - у 863 пациентов (11,4%). Во второй группе зарегистрирован 101 случай (1,4%) острого проксимального тромбоза глубоких вен, дистальный тромбоз - в 469 (6,6%) случаях. При этом доля оперативных вмешательств на венах нижних конечностей значительно уменьшилась, с 0,5% до 0,1%. В 3 раза снизилось количество фактов ТЭЛА. Переход на более ранние сроки исследований в послеоперационном периоде во второй группе и с внедрением способа диагностики просвета глубоких вен в виде симптома «снежной метели» (патент на изобретение в РФ № №2547072 от 2015 г.), позволило выделить пациентов в группу высокого риска (2,6%), скорректировать послеоперационное медикаментозное лечение, тем самым остановить манифестацию патологического процесса. Выводы и заключение. Ранняя диагностика позволила выявить начальные этапы формирования венозных тромбозов, скорректировать тактику лечения пациента, уменьшить количество операций на сосудах, улучшить результаты лечения - эндопротезирование, уменьшить длительность пребывания больного на койке, снизить материально-денежную нагрузку на лечебное учреждение, повысить качество жизни пациента

    A Role for the Immediate Early Gene Product c-fos in Imprinting T Cells with Short-Term Memory for Signal Summation

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    T cells often make sequential contacts with multiple DCs in the lymph nodes and are likely to be equipped with mechanisms that allow them to sum up the successive signals received. We found that a period of stimulation as short as two hours could imprint on a T cell a “biochemical memory” of that activation signal that persisted for several hours. This was evidenced by more rapid induction of activation markers and earlier commitment to proliferation upon subsequent stimulation, even when that secondary stimulation occurred hours later. Upregulation of the immediate early gene product c-fos, a component of the AP-1 transcription factor, was maximal by 1–2 hours of stimulation, and protein levels remained elevated for several hours after stimulus withdrawal. Moreover, phosphorylated forms of c-fos that are stable and transcriptionally active persisted for a least a day. Upon brief antigenic stimulation in vivo, we also observed a rapid upregulation of c-fos that could be boosted by subsequent stimulation. Accumulation of phosphorylated c-fos may therefore serve as a biochemical fingerprint of previous suboptimal stimulation, leaving the T cell poised to rapidly resume its activation program upon its next encounter with an antigen-bearing DC
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