188 research outputs found

    Glyco-engineered MDCK cells display preferred receptors of H3N2 influenza absent in eggs used for vaccines

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    Evolution of human H3N2 influenza viruses driven by immune selection has narrowed the receptor specificity of the hemagglutinin (HA) to a restricted subset of human-type (Neu5Acα2-6 Gal) glycan receptors that have extended poly-LacNAc (Galβ1-4GlcNAc) repeats. This altered specificity has presented challenges for hemagglutination assays, growth in laboratory hosts, and vaccine production in eggs. To assess the impact of extended glycan receptors on virus binding, infection, and growth, we have engineered N-glycan extended (NExt) cell lines by overexpressing β3-Ν-acetylglucosaminyltransferase 2 in MDCK, SIAT, and hCK cell lines. Of these, SIAT-NExt cells exhibit markedly increased binding of H3 HAs and susceptibility to infection by recent H3N2 virus strains, but without impacting final virus titers. Glycome analysis of these cell lines and allantoic and amniotic egg membranes provide insights into the importance of extended glycan receptors for growth of recent H3N2 viruses and relevance to their production for cell- and egg-based vaccines

    Acute effects of an instructional movie on drop jump performance and lower limb kinematic and kinetic variables

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    Objectives: Drop jump (DJ) is a typical exercise of plyometric training in which the state before takeoff (pre-set phase) influences the force exertion of the lower limbs during takeoff, as well as performance variables. This study aimed to examine the effects of watching an instructional movie during the pre-set phase on the performance and lower limb kinematic and kinetic variables during plyometric training.Methods: Fourteen participants (age, 21.9 ± 2.1 years; height, 175.6 ± 2.6 cm; weight, 70.7 ± 4.9 kg) were enrolled in this study. Seven participants with a high rebound jump (RJ) index under normal conditions were classified into the high RJ-index group. Seven participants with a low RJ-index were classified into the low RJ-index group. DJs were performed under normal conditions and under the movie condition (DJ immediately after watching the instructional movie during the pre-set phase). Performance and kinematic and kinetic variables of the lower limb joints were measured.Results: Compared with the normal condition, the movie condition was associated with a significantly high RJ-index, lesser degree of knee flexion (p < 0.011), and significantly larger concentric torque (p < 0.018) of the ankle. An interaction effect was observed for the eccentric torque (p < 0.025) and positive power (p < 0.004) of the ankle, which were significantly greater in the high RJ-index group under the movie condition.Conclusion: Watching an instructional movie during the pre-set phase improves the movement and force production of the ankle and knee joint, which, in turn, improves the DJ performance. However, the effects may be more pronounced in participants with a high RJ-index

    Native T1 high region and left ventricular ejection fraction recovery in patients with dilated cardiomyopathy

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    Native T1 mapping is used to assess myocardial tissue characteristics without gadolinium contrast agents. The focal T1 high-intensity region can indicate myocardial alterations. This study aimed to identify the association between the native T1 mapping including the native T1 high region and left ventricular ejection fraction (LVEF) recovery in patients with dilated cardiomyopathy (DCM). Patients with newly diagnosed DCM (LVEF of 5 SD in the remote myocardium. Recovered EF was defined as a follow-up LVEF of >= 45% and an LVEF increase of >= 10% after 2 years from baseline. Seventy-one patients met the inclusion criteria for this study. Forty-four patients (61.9%) achieved recovered EF. Logistic regression analysis showed that the native T1 value (OR: 0.98; 95% CI: 0.96-0.99; P = 0.014) and the native T1 high region (OR: 0.17; 95% CI: 0.05-0.55; P = 0.002), but not late gadolinium enhancement, were independent predictors of recovered EF. Compared with native T1 value alone, combined native T1 high region and native T1 value improved the area under the curve from 0.703 to 0.788 for predicting recovered EF. Myocardial damage, which was quantified using native T1 mapping and the native T1 high region were independently associated with recovered EF in patients with newly diagnosed DCM.Cardiolog

    Multivalent S2-based vaccines provide broad protection against SARS-CoV-2 variants of concern and pangolin coronaviruses

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    Background: The COVID-19 pandemic continues to cause morbidity and mortality worldwide. Most approved COVID-19 vaccines generate a neutralizing antibody response that primarily targets the highly variable receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein. SARS-CoV-2 “variants of concern” have acquired mutations in this domain allowing them to evade vaccine-induced humoral immunity. Recent approaches to improve the breadth of protection beyond SARS-CoV-2 have required the use of mixtures of RBD antigens from different sarbecoviruses. It may therefore be beneficial to develop a vaccine in which the protective immune response targets a more conserved region of the S protein. Methods: Here we have developed a vaccine based on the conserved S2 subunit of the S protein and optimized the adjuvant and immunization regimen in Syrian hamsters and BALB/c mice. We have characterized the efficacy of the vaccine against SARS-CoV-2 variants and other coronaviruses. Findings: Immunization with S2-based constructs elicited a broadly cross-reactive IgG antibody response that recognized the spike proteins of not only SARS-CoV-2 variants, but also SARS-CoV-1, and the four endemic human coronaviruses. Importantly, immunization reduced virus titers in respiratory tissues in vaccinated animals challenged with SARS-CoV-2 variants B.1.351 (beta), B.1.617.2 (delta), and BA.1 (omicron) as well as a pangolin coronavirus. Interpretation: These results suggest that S2-based constructs can elicit a broadly cross-reactive antibody response resulting in limited virus replication, thus providing a framework for designing vaccines that elicit broad protection against coronaviruses. Funding: NIH, Japan Agency for Medical Research and Development, Garry Betty/ V Foundation Chair Fund, and NSF

    Measurement of the spin and magnetic moment of 23Al

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    For the first time, we obtained the g factor for the ground state of 23Al by use of a -NMR measurement. 23Al has a small proton separation energy and is a potential proton-halo candidate. The obtained g factor, |g|=1.557±0.088, clearly shows the spin and parity, J=5/2+, for 23Al, which is the same as that of its mirror partner, 23Ne. The possible nuclear structure of 23Al is also discussed

    Co-administration of Favipiravir and the Remdesivir Metabolite GS-441524 Effectively Reduces SARS-CoV-2 Replication in the Lungs of the Syrian Hamster Model

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide since December 2019, causing coronavirus disease 2019 (COVID-19). Although vaccines for this virus have been developed rapidly, repurposing drugs approved to treat other diseases remains an invaluable treatment strategy. Here, we evaluated the inhibitory effects of drugs on SARS-CoV-2 replication in a hamster infection model and in in vitro assays. Favipiravir significantly suppressed virus replication in hamster lungs. Remdesivir inhibited virus replication in vitro, but was not effective in the hamster model. However, GS-441524, a metabolite of remdesivir, effectively suppressed virus replication in hamsters. Co-administration of favipiravir and GS-441524 more efficiently reduced virus load in hamster lungs than did single administration of either drug for both the prophylactic and therapeutic regimens; prophylactic co-administration also efficiently inhibited lung inflammation in the infected animals. Furthermore, pretreatment of hamsters with favipiravir and GS-441524 effectively protected them from virus transmission via respiratory droplets upon exposure to infected hamsters. Repurposing and co-administration of antiviral drugs may help combat COVID-19. IMPORTANCE During a pandemic, repurposing drugs that are approved for other diseases is a quick and realistic treatment option. In this study, we found that co-administration of favipiravir and the remdesivir metabolite GS-441524 more effectively blocked SARS-CoV-2 replication in the lungs of Syrian hamsters than either favipiravir or GS-441524 alone as part of a prophylactic or therapeutic regimen. Prophylactic co-administration also reduced the severity of lung inflammation. Moreover, co-administration of these drugs to naive hamsters efficiently protected them from airborne transmission of the virus from infected animals. Since both drugs are nucleotide analogs that interfere with the RNA-dependent RNA polymerases of many RNA viruses, these findings may also help encourage co-administration of antivirals to combat future pandemics

    HIF2α reduces growth rate but promotes angiogenesis in a mouse model of neuroblastoma

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    <p>Abstract</p> <p>Background</p> <p>HIF2α/EPAS1 is a hypoxia-inducible transcription factor involved in catecholamine homeostasis, vascular remodelling, physiological angiogenesis and adipogenesis. It is overexpressed in many cancerous tissues, but its exact role in tumour progression remains to be clarified.</p> <p>Methods</p> <p>In order to better establish its function in tumourigenesis and tumour angiogenesis, we have stably transfected mouse neuroblastoma N1E-115 cells with the native form of HIF2α or with its dominant negative mutant, HIF2α (1–485) and studied their phenotype <it>in vitro </it>and <it>in vivo</it>.</p> <p>Results</p> <p><it>In vitro </it>studies reveal that HIF2α induces neuroblastoma cells hypertrophy and decreases their proliferation rate, while its inactivation by the HIF2α (1–485) mutant leads to a reduced cell size, associated with an accelerated proliferation. However, our <it>in vivo </it>experiments show that subcutaneous injection of cells overexpressing HIF2α into syngenic mice, leads to the formation of tumour nodules that grow slower than controls, but that are well structured and highly vascularized. In contrast, HIF2α (1–485)-expressing neuroblastomas grow fast, but are poorly vascularized and quickly tend to extended necrosis.</p> <p>Conclusion</p> <p>Together, our data reveal an unexpected combination between an antiproliferative and a pro-angiogenic function of HIF2α that actually seems to be favourable to the establishment of neuroblastomas <it>in vivo</it>.</p

    Culprit segments identified by optical coherence tomography in patients with acute myocardial infarction: Two case reports

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    The high resolution of optical coherence tomography (OCT) provides detailed information about coronary plaque morphology, which enables the mechanism of acute myocardial infarction to be evaluated. We describe two patients with acute myocardial infarction in whom culprit segments were identified by OCT, but not by either coronary angiography or intravascular ultrasound

    Phase-I trial of oral fluoropyrimidine anticancer agent (S-1) with concurrent radiotherapy in patients with unresectable pancreatic cancer

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    In this phase-I trial, we evaluated the safety of S-1, a novel oral fluoropyrimidine anticancer agent, combined with external-beam radiotherapy (EBRT) to determine the maximum-tolerated dose and dose-limiting toxicity (DLT) in unresectable pancreatic cancer patients. Patients had histologically proven unresectable locally advanced or metastatic pancreatic cancer. S-1 was administered orally twice daily. External-beam radiotherapy was delivered in fractions of 1.25 Gy × 2 per day, totalling 50 Gy per 40 fractions for 4 weeks. S-1 was given at five dose levels: 60 mg m–2 day–1 on days 1–7 and 15–21 (level 1), 1–14 (level 2), and 1–21 (level 3a) and 80 mg m–2 day–1 on days 1–21 (level 3b) and 1–28 (level 4). We studied 17 patients: dose levels 1 (four patients), 2 (four patients), 3a (three patients), 3b (three patients), and 4 (three patients). One patient in level 1 (grade 3 vomiting) and two patients in level 4 (grade 4 neutropenia and grade 3 anorexia) showed DLT. No DLT was seen for levels 2, 3a, and 3b. Clinical effects by computed tomography included 5 partial responses (35%), 11 cases of stable disease, and one case of progressive disease. CA19–9 levels of less than half the starting values were observed in 8 of 16 (50%) patients. S-1 at a dose of 80 mg m–2 day–1 given on days 1–21 is safe and recommended for phase-II study in patients with locally advanced and unresectable pancreatic cancer when given with EBRT
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