Observation of the production of a W boson in association with a single charm quark

The first observation of the production of a W boson with a single charm quark (c) jet in pp[over ¯] collisions at √s=1.96  TeV is reported. The analysis uses data corresponding to 4.3  fb(-1), recorded with the CDF II detector at the Fermilab Tevatron. Charm quark candidates are selected through the identification of an electron or muon from charm-hadron semileptonic decay within a hadronic jet, and a Wc signal is observed with a significance of 5.7 standard deviations. The production cross section σ(Wc)(p(Tc)>20  GeV/c,|η(c)|<1.5)×B(W→ℓν) is measured to be 13.6(-3.1)(+3.4)  pb and is in agreement with theoretical expectations. From this result the magnitude of the quark-mixing matrix element V(cs) is derived, |V(cs)|=1.08±0.16 along with a lower limit of |V(cs)|>0.71 at the 95% confidence level, assuming that the Wc production through c to s quark coupling is dominant.

Primary paraganglioma of the lung: a case report and literature review

Only 22 cases of primary pulmonary paraganglioma have been reported previously. This report presents a case of paraganglioma that arose in the lung of a 38-year-old woman who presented with chest pain and paroxysmal cough with little sputum. Positron emission tomography-computed tomography scan demonstrated two homogeneous masses in the left lower lobe accompanied by multiple mediastinal lymph node metastases. After resection, gross pathological examination confirmed two solid masses, which had a yellow-grey complexion and decreased blood supply and that invaded the mediastinum. Immunohistochemical analysis confirmed the presence of several biological tumour markers. This is the first known report to describe the computed tomography imaging characteristics of a paraganglioma, thereby improving understanding of its morphological features and helping in the differential diagnosis of lung tumours.

Cooperative role of RanBP9 and P73 in mitochondria-mediated apoptosis

Mitochondrial dysfunction and synaptic damage are critical early features of Alzheimer's disease (AD) associated with amyloid β (Aβ) and τ. We previously reported that the scaffolding protein RanBP9, which is overall increased in AD, simultaneously promotes Aβ generation and focal adhesion disruption by accelerating the endocytosis of APP and β1-integrin, respectively. Moreover, RanBP9 induces neurodegeneration in vitro and in vivo and mediates Aβ-induced neurotoxicity. However, little is known regarding the mechanisms underlying such neurotoxic processes. Here, we show that RanBP9 induces the loss of mitochondrial membrane potential and increase in mitochondrial superoxides associated with decrease in Bcl-2, increase in Bax protein and oligomerization, fragmentation of mitochondria, and cytochrome c release. RanBP9-induced neurotoxic changes are significantly prevented by the mitochondrial fission inhibitor Mdivi-1 and by classical inhibitors of the mitochondrial apoptosis, XIAP, Bcl-2, and Bcl-xl. RanBP9 physically interacts with the tumor suppressor p73 and increases endogenous p73α levels at both transcriptional and post-translational levels;moreover, the knockdown of endogenous p73 by siRNA effectively blocks RanBP9 and Aβ1-42-induced mitochondria-mediated cell death. Conversely, siRNA knockdown of endogenous RanBP9 also suppresses p73-induced apoptosis, suggesting that RanBP9 and p73 have cooperative roles in inducing cell death. Taken together, these finding implicate the RanBP9/p73 complex in mitochondria-mediated apoptosis in addition to its role in enhancing Aβ generation.

Rapid and sensitive detection of Curvularia lunata associated with maize leaf spot based on its Clg2p gene using semi-nested PCR

Curvularia lunata (Wakker) Boed, the causative agent of Curvularia leaf spot in maize, was determined according to conidiophore and conidium morphology in a previous study. In the current study, a sensitive polymerase chain reaction assay was developed for the detection of C. lunata. Two specific forward (ClgD1/ClgD2) and one reverse primers (ClgD3) were designed based on a Ras-related (Clg2p) gene. Eight C. lunata isolates that represent different virulent strains in maize, six other Curvularia spp., and 22 fungal plant pathogens were used to test the specificity of the primers. PCR amplification using ClgD1/ClgD3 as the first-round primers resulted in an 870-bp band from the C. lunata isolates. The detection sensitivity using ClgD1/ClgD3 was 100 pg of genomic DNA. In the second round of PCR, a 1 : 50 dilution of the first-round PCR products was used as a template with the ClgD2/ClgD3 primer pair, which increased the detection sensitivity to 1 fg. This semi-nested PCR procedure could also be used to detect C. lunata from infected maize leaves. The proposed PCR-based assay may be used for diagnosing and monitoring maize Curvularia leaf spot.

SIGNIFICANCE AND IMPACT OF THE STUDY

The semi-nested PCR assay may provide researchers and laboratory technologists a tool to rapidly detect C. lunata, which causes maize Curvularia leaf spot, compared with histological examination.

Biochemical and functional characterization of a recombinant monomeric factor VIII-Fc fusion protein

BACKGROUND

Hemophilia A results from a deficiency in factor VIII activity. Current treatment regimens require frequent dosing, owing to the short half-life of FVIII. A recombinant FVIII-Fc fusion protein (rFVIIIFc) was molecularly engineered to increase the half-life of FVIII, by 1.5-2-fold, in several preclinical animal models and humans.

OBJECTIVE

To perform a biochemical and functional in vitro characterization of rFVIIIFc, with existing FVIII products as comparators.

METHODS

 rFVIIIFc was examined by utilizing a series of structural and analytic assays, including mass spectrometry following lysyl endopeptidase or thrombin digestion. rFVIIIFc activity was determined in both one-stage clotting (activated partial thromboplastin time) and chromogenic activity assays, in the context of the FXase complex with purified components, and in both in vitro and ex vivo rotational thromboelastometry (ROTEM) assays performed in whole blood.

RESULTS

 rFVIIIFc contained the predicted primary structure and post-translational modifications, with an FVIII moiety that was similar to other recombinant FVIII products. The von Willebrand factor-binding and specific activity of rFVIIIFc were also found to be similar to those of other recombinant FVIII molecules. Both chromogenic and one-stage assays of rFVIIIFc gave similar results. Ex vivo ROTEM studies demonstrated that circulating rFVIIIFc activity was prolonged in mice with hemophilia A in comparison with B-domain-deleted or full-length FVIII. Clot parameters at early time points were similar to those for FVIII, whereas rFVIIIFc showed prolonged improvement of clot formation.

CONCLUSIONS

 rFVIIIFc maintains normal FVIII interactions with other proteins necessary for its activity, with prolonged in vivo activity, owing to fusion with the Fc region of IgG(1) .

FBXW7 regulates glucocorticoid response in T-cell acute lymphoblastic leukaemia by targeting the glucocorticoid receptor for degradation

Loss of function mutation in FBXW7, an E3 ubiquitin ligase, is associated with good prognosis and early glucocorticoid treatment response in childhood T-cell acute lymphoblastic leukemia (T-ALL) by unknown mechanisms. Here, we show that FBXW7 targets the glucocorticoid receptor α (GRα) for ubiquitylation and proteasomal degradation in a manner dependent on glycogen synthase kinase 3 β-mediated phsophorylation. FBXW7 inactivation caused elevated GRα levels, and enhanced the transcriptional response to glucocorticoids. There was significant enhancement of GR transcriptional responses in FBXW7-deficient cell lines and primary T-ALL samples, in particular, for those pro-apoptotic regulatory proteins, BIM and PUMA. Reduced FBXW7 expression or function promoted glucocorticoid sensitivity, but not sensitivity to other chemotherapeutic agents used in T-ALL. Moreover, this was a general feature of different cancer cell types. Taken together, our work defines GRα as a novel FBXW7 substrate and demonstrates that favorable patient prognosis in T-ALL is associated with FBXW7 mutations due to enhanced GRα levels and steroid sensitivity. These findings suggest that inactivation of FBXW7, a putative tumor suppressor protein, may create a synthetic lethal state in the presence of specific anticancer therapies.

Adenovirus-mediated delivery of soluble ST2 attenuates ovalbumin-induced allergic asthma in mice

Allergic asthma is associated with excessive T helper type 2 (Th2) cells activation and airway hyperreactivity (AHR), implicated in the context of significant morbidity and mortality. Soluble ST2, a member of the interleukin (IL)-1 receptor family, has been shown to play a critical role in modulation of inflammatory disorders, yet the function of soluble ST2 in allergic inflammation remains unclear. In this study, we examined the possibility of regulating ovalbumin (OVA)-challenged airway inflammation by recombinant adenovirus-mediated sST2-Fc (Ad-sST2-Fc) gene transfer. Single intranasal administration of Ad-sST2-Fc before allergen challenge in OVA-immunized mice profoundly reduced serum immunoglobulin (Ig)E secretion, eosinophil infiltration and concentrations of IL-4, IL-5 and IL-13 in bronchoalveolar lavage fluid compared with administration of a control Ad vector. Histopathological examination of the lungs revealed that sST2-Fc over-expression markedly suppressed allergen-induced peribronchial inflammation and disruption of the alveolar architecture. Moreover, the beneficial effect of sST2-Fc in allergic lung inflammation is related to blocking the IL-33/ST2L signalling. Taken together, these results suggested that administration of Ad-sST2-Fc gene transfer may have therapeutic potential for the immunomodulatory treatment of OVA-mediated allergic pulmonary diseases.

Measurements of the top-quark mass and the tt cross section in the hadronic τ+jets decay channel at sqrt[s] = 1.96 TeV

We present the first direct measurement of the top-quark mass using tt events decaying in the hadronic τ+jets decay channel. Using data corresponding to an integrated luminosity of 2.2 fb(-1) collected by the CDF II detector in pp collisions at sqrt[s] = 1.96 TeV at the Fermilab Tevatron, we measure the tt cross section, σ(tt), and the top-quark mass, M(top). We extract M(top) from a likelihood based on per-event probabilities calculated with leading-order signal and background matrix elements. We measure σ(tt) = 8.8 ± 3.3(stat) ± 2.2(syst) pb and M(top) = 172.7 ± 9.3(stat) ± 3.7(syst) GeV/c(2).

Search for the standard model Higgs Boson produced in association with top quarks using the full CDF data set

A search is presented for the standard model Higgs boson produced in association with top quarks using the full Run II proton-antiproton collision data set, corresponding to 9.45 fb(-1), collected by the Collider Detector at Fermilab. No significant excess over the expected background is observed, and 95% credibility-level upper bounds are placed on the cross section σ(ttH → lepton + missing transverse energy+jets). For a Higgs boson mass of 125 GeV/c(2), we expect to set a limit of 12.6 and observe a limit of 20.5 times the standard model rate. This represents the most sensitive search for a standard model Higgs boson in this channel to date.

Measurement of the bottom-strange meson mixing phase in the full CDF data set

We report a measurement of the bottom-strange meson mixing phase β(s) using the time evolution of B(s)(0)→J/ψ(→μ(+)μ(-))φ(→K(+)K(-)) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at √s=1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb(-1) of integrated luminosity. We report confidence regions in the two-dimensional space of β(s) and the B(s)(0) decay-width difference ΔΓ(s) and measure β(s)∈[-π/2,-1.51]∪[-0.06,0.30]∪[1.26,π/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of β(s), we also determine ΔΓ(s)=0.068±0.026(stat)±0.009(syst) ps(-1) and the mean B(s)(0) lifetime τ(s)=1.528±0.019(stat)±0.009(syst) ps, which are consistent and competitive with determinations by other experiments.

High expression of CD98 alters epithelial barrier functions to promote induction of airway allergy

BACKGROUND

Epithelial barrier dysfunction is critical in the induction of allergy; the aetiology is to be further understood. A recent report indicates that CD98 plays a role in the intestinal epithelial barrier dysfunction.

OBJECTIVES

This study aimed to investigate the role of overexpression of CD98 in the induction of nasal allergy.

METHODS

The nasal epithelium samples were collected from 30 patients with allergic rhinitis and 30 healthy subjects. The contents of CD98 and Staphylococcal enterotoxin B (SEB) in the nasal epithelium samples were evaluated by using Western blotting. The effect of SEB of inducing the expression of CD98 was evaluated with an airway epithelial cell line, the 16HBE14o cells. The epithelial barrier function was assessed with the indicators of transepithelial resistance (TER) and permeability to horseradish peroxidase (HRP). A mouse model was employed to evaluate the role of CD98 in the induction of nasal allergy.

RESULTS

High levels of CD98 and SEB were detected in the nasal epithelium of patients with allergic rhinitis. A positive correlation was identified between CD98 and SEB in nasal epithelium samples. Exposure to SEB could induce the overexpression of CD98 in RPMI 2650 and 16HBE14o cells. The overexpression of CD98 down-regulated TER and increased the permeability to HRP in 16HBE14o monolayers. Concurrent exposure to SEB and OVA induced nasal allergies in a mouse model that could be blocked by pre-treatment with anti-CD98 antibody.

CONCLUSIONS AND CLINICAL RELEVANCE

CD98 plays a critical role in compromising the airway epithelial barrier function that contributes to the induction of airway allergy.

Precision top-quark mass measurement at CDF

We present a precision measurement of the top-quark mass using the full sample of Tevatron √s = 1.96 TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb(-1). Using a sample of tt¯ candidate events decaying into the lepton+jets channel, we obtain distributions of the top-quark masses and the invariant mass of two jets from the W boson decays from data. We then compare these distributions to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with in situ calibration. The likelihood fit of the templates from signal and background events to the data yields the single most-precise measurement of the top-quark mass, M(top)=172.85±0.71(stat)±0.85(syst) GeV/c(2).

Monte Carlo N-particle simulation of neutron-based sterilisation of anthrax contamination

OBJECTIVE

To simulate the neutron-based sterilisation of anthrax contamination by Monte Carlo N-particle (MCNP) 4C code.

METHODS

Neutrons are elementary particles that have no charge. They are 20 times more effective than electrons or γ-rays in killing anthrax spores on surfaces and inside closed containers. Neutrons emitted from a (252)Cf neutron source are in the 100 keV to 2 MeV energy range. A 2.5 MeV D-D neutron generator can create neutrons at up to 10(13) n s(-1) with current technology. All these enable an effective and low-cost method of killing anthrax spores.

RESULTS

There is no effect on neutron energy deposition on the anthrax sample when using a reflector that is thicker than its saturation thickness. Among all three reflecting materials tested in the MCNP simulation, paraffin is the best because it has the thinnest saturation thickness and is easy to machine. The MCNP radiation dose and fluence simulation calculation also showed that the MCNP-simulated neutron fluence that is needed to kill the anthrax spores agrees with previous analytical estimations very well.

CONCLUSION

The MCNP simulation indicates that a 10 min neutron irradiation from a 0.5 g (252)Cf neutron source or a 1 min neutron irradiation from a 2.5 MeV D-D neutron generator may kill all anthrax spores in a sample. This is a promising result because a 2.5 MeV D-D neutron generator output >10(13) n s(-1) should be attainable in the near future. This indicates that we could use a D-D neutron generator to sterilise anthrax contamination within several seconds.

Search for the standard model Higgs boson decaying to a bb pair in events with one charged lepton and large missing transverse energy using the full CDF data set

We present a search for the standard model Higgs boson produced in association with a W boson in sqrt[s]=1.96  TeV pp collision data collected with the CDF II detector at the Tevatron corresponding to an integrated luminosity of 9.45  fb(-1). In events consistent with the decay of the Higgs boson to a bottom-quark pair and the W boson to an electron or muon and a neutrino, we set 95% credibility level upper limits on the WH production cross section times the H→bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125  GeV/c(2), we observe (expect) a limit of 4.9 (2.8) times the standard model value.

Measurement of the difference in CP-violating asymmetries in D(0)→K(+)K(-) and D(0)→π(+)π(-) decays at CDF

We report a measurement of the difference (ΔA(CP)) between time-integrated CP-violating asymmetries in D(0)→K(+)K(-) and D(0)→π(+)π(-) decays reconstructed in the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab, corresponding to 9.7  fb(-1) of integrated luminosity. The strong decay D(*+)→D(0)π(+) is used to identify the charm meson at production as D(0) or D[over ¯](0). We measure ΔA(CP)=[-0.62±0.21(stat)±0.10(syst)]%, which differs from zero by 2.7 Gaussian standard deviations. This result supports similar evidence for CP violation in charm-quark decays obtained in proton-proton collisions.