1,204 research outputs found

    A factor IX variant that functions independently of factor VIII mitigates the hemophilia A phenotype in patient plasma

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    BackgroundRecombinant factor (F)IX-FIAV has previously been shown to function independently of activated FVIII (FVIIIa) and ameliorate the hemophilia A (HA) phenotype in vitro and in vivo.ObjectivesThe aim of this study was to assess the efficacy of FIX-FIAV in plasma from HA patients using thrombin generation (TG) and intrinsic clotting activity (activated partial thromboplastin time [APTT]) analyses.MethodsPlasma obtained from 21 patients with HA (>18 years; 7 mild, 7 moderate, and 7 severe patients) was spiked with FIX-FIAV. The FXIa-triggered TG lag time and APTT were quantified in terms of FVIII-equivalent activity using FVIII calibration for each patient plasma.ResultsThe linear, dose-dependent improvement in the TG lag time and APTT reached its maximum with approximately 400% to 600% FIX-FIAV in severe HA plasma and with approximately 200% to 250% FIX-FIAV in nonsevere HA plasma. The cofactor-independent contribution of FIX-FIAV was therefore suggested and confirmed by the addition of inhibitory anti-FVIII antibodies to nonsevere HA plasma, resulting in a FIX-FIAV response similar to severe HA plasma. Addition of 100% (5 Οg/mL) FIX-FIAV mitigated the HA phenotype from severe to moderate (from ConclusionFIX-FIAV is capable of increasing the FVIII-equivalent activity and coagulation activity in plasma from HA patients, thereby mitigating the HA phenotype. Hence, FIX-FIAV could serve as a potential treatment for HA patients with or without inhibitors.Thrombosis and Hemostasi

    Effects of physical activity on functional health of older adults: a systematic review

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    Reviews on the relationships between functional health and physical activity of general older adults have been well documented in literature. However, specific age range of older adults, in particular, older adults of 75 years or above, is currently under-examined. A systematic review was conducted to investigate the effects of physical activity on functional health older adults aged 75 years or above. The reviewed articles cover a variety range of functional health outcomes, including balance, muscle conditioning, joint range of motion, quadriceps strength, reaction time, gait speed, health-related quality of life, back and knee pain, muscle mass, and walking ability. In general, interventions of the reviewed articles had favourable effects on function health of older adults. While physical activity has been identified as an important determinant of functional health, the ways to engage in and accumulate sufficient daily physical activity warrant investigation. It is also important to explore interventions which enhance daily, self-driven physical activity of elderly, as normally supervised physical activity bears higher costs

    Comparing hybrid and regular COVID-19 vaccine-induced immunity against the Omicron epidemic

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    Evidence on the effectiveness of COVID-19 vaccines among people who recovered from a previous SARS-CoV-2 infection is warranted to inform vaccination recommendations. Using the territory-wide public healthcare and vaccination records of over 2.5 million individuals in Hong Kong, we examined the potentially differential risk of SARS-CoV-2 infection, hospitalization, and mortality between those receiving two homologous doses of BNT162b2 or CoronaVac versus those with a previous infection receiving only one dose amid the Omicron epidemic. Results show a single dose after a SARS-CoV-2 infection is associated with a lower risk of infection (BNT162b2: adjusted incidence rate ratio [IRR] = 0.475, 95% CI: 0.410–0.550; CoronaVac: adjusted IRR = 0.397, 95% CI: 0.309–0.511) and no significant difference was detected in the risk of COVID-19-related hospitalization or mortality compared with a two-dose vaccination regimen. Findings support clinical recommendations that those with a previous infection could receive a single dose to gain at least similar protection as those who received two doses without a previous infection

    Distinct Roles of Brd2 and Brd4 in Potentiating the Transcriptional Program for Th17 Cell Differentiation

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    The BET proteins are major transcriptional regulators and have emerged as new drug targets, but their functional distinction has remained elusive. In this study, we report that the BET family members Brd2 and Brd4 exert distinct genomic functions at genes whose transcription they co-regulate during mouse T-helper 17 (Th17) cell differentiation. Brd2 is associated with the chromatin insulator CTCF and the cohesin complex to support cis-regulatory enhancer assembly for gene transcriptional activation. In this context, Brd2 binds the transcription factor Stat3 in an acetylation-sensitive manner and facilitates Stat3 recruitment to active enhancers occupied with transcription factors Irf4 and Batf. In parallel, Brd4 temporally controls RNA polymerase II (Pol II) processivity during transcription elongation through cyclinT1/Cdk9 recruitment and Pol II Ser2 phosphorylation. Collectively, our study uncovers both separate and interdependent Brd2 and Brd4 functions in potentiating the genetic program required for Th17 cell development and adaptive immunity., , Cheung et al. uncover both separate and interdependent Brd2 and Brd4 genomic functions in potentiating the genetic program required for Th17 cell development and adaptive immunity. Brd2 interacts with transcription factor Stat3 and chromatin insulator CTCF/cohesin complex to support enhancer assembly, whereas Brd4 temporally controls RNA PolII for transcription elongation

    Modulation of Mouse Coagulation Gene Transcription following Acute In Vivo Delivery of Synthetic Small Interfering RNAs Targeting HNF4Îą and C/EBPÎą

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    Hepatocyte nuclear factor 4Îą (HNF4Îą) and CCAAT/enhancer-binding protein Îą (C/EBPÎą) are important for the transcriptional control of coagulation factors. To determine in vivo the direct role of HNF4Îą and C/EBPÎą in control of genes encoding coagulation factors, a synthetic small interfering (si)RNA approach was used that enabled strong reduction of mouse hepatic HNF4Îą and C/EBPÎą under conditions that minimized target-related secondary effects. For both HNF4Îą and C/EBPÎą, intravenous injection of specific synthetic siRNAs (siHNF4Îą and siC/EBPÎą) resulted in more than 75% reduction in their liver transcript and protein levels 2 days post-injection. For siHNF4Îą, this coincided with marked and significantly reduced transcript levels of the coagulation genes Hrg, Proz, Serpina5, F11, F12, F13b, Serpinf2, F5, and F9 (in order of magnitude of effect) as compared to levels in control siRNA injected animals. Significant decreases in HNF4Îą target gene mRNA levels were also observed at 5 days post-siRNA injection, despite a limited level of HNF4Îą knockdown at this time point. Compared to HNF4Îą, C/EBPÎą knockdown had a modest impact on genes encoding coagulation factors. A strong reduction in C/EBPÎą transcript and protein levels resulted in significantly affected transcript levels of the control genes Pck1 and Fasn and a modest downregulation for coagulation genes Fba, Fbg and F5. F5 and F11 were the sole coagulation genes that were significantly affected upon prolonged (5 day) C/EBPÎą knockdown. We conclude that in the mouse, HNF4Îą has a direct and essential regulatory role for multiple hepatic coagulation genes, while a role for C/EBPÎą is more restricted. In addition, this study demonstrates that synthetic siRNA provides a simple and fast means for determining liver transcription factor involvement in vivo

    Mammalian Ste20-Like Kinase and SAV1 Promote 3T3-L1 Adipocyte Differentiation by Activation of PPARÎł

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    The mammalian ste20 kinase (MST) signaling pathway plays an important role in the regulation of apoptosis and cell cycle control. We sought to understand the role of MST2 kinase and Salvador homolog 1 (SAV1), a scaffolding protein that functions in the MST pathway, in adipocyte differentiation. MST2 and MST1 stimulated the binding of SAV1 to peroxisome proliferator-activated receptor Îł (PPARÎł), a transcription factor that plays a key role in adipogenesis. The interaction of endogenous SAV1 and PPARÎł was detected in differentiating 3T3-L1 adipocytes. This binding required the kinase activity of MST2 and was mediated by the WW domains of SAV1 and the PPYY motif of PPARÎł. Overexpression of MST2 and SAV1 increased PPARÎł levels by stabilizing the protein, and the knockdown of SAV1 resulted in a decrease of endogenous PPARÎł protein in 3T3-L1 adipocytes. During the differentiation of 3T3-L1 cells into adipocytes, MST2 and SAV1 expression began to increase at 2 days when PPARÎł expression also begins to increase. MST2 and SAV1 significantly increased PPARÎł transactivation, and SAV1 was shown to be required for the activation of PPARÎł by rosiglitazone. Finally, differentiation of 3T3-L1 cells was augmented by MST2 and SAV1 expression and inhibited by knockdown of MST1/2 or SAV1. These results suggest that PPARÎł activation by the MST signaling pathway may be a novel regulatory mechanism of adipogenesis

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    X-ray emission from the Sombrero galaxy: discrete sources

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    We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
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