Alpha B-crystallin protects retinal tissue during Staphylococcus aureus-induced endophthalmitis

Bacterial infections of the eye highlight a dilemma that is central to all immune-privileged sites. On the one hand, immune privilege limits inflammation to prevent bystander destruction of normal tissue and loss of vision. On the other hand, bacterial infections require a robust inflammatory response for rapid clearance of the pathogen. We demonstrate that the retina handles this dilemma, in part, by activation of a protective heat shock protein. During Staphylococcus aureus-induced endophthalmitis, the small heat shock protein αB-crystallin is upregulated in the retina and prevents apoptosis during immune clearance of the bacteria. In the absence of αB-crystallin, mice display increased retinal apoptosis and retinal damage. We found that S. aureus produces a protease capable of cleaving αB-crystallin to a form that coincides with increased retinal apoptosis and tissue destruction. We conclude that αB-crystallin is important in protecting sensitive retinal tissue during destructive inflammation that occurs during bacterial endophthalmitis

A Novel PAN/Apple Domain-Containing Protein from Toxoplasma gondii: Characterization and Receptor Identification

Toxoplasma gondii is an intracellular parasite that invades nucleated cells, causing toxoplasmosis in humans and animals worldwide. The extremely wide range of hosts susceptible to T. gondii is thought to be the result of interactions between T. gondii ligands and receptors on its target cells. In this study, a host cell-binding protein from T. gondii was characterized, and one of its receptors was identified. P104 (GenBank Access. No. CAJ20677) is 991 amino acids in length, containing a putative 26 amino acid signal peptide and 10 PAN/apple domains, and shows low homology to other identified PAN/apple domain-containing molecules. A 104-kDa host cell-binding protein was detected in the T. gondii lysate. Immunofluorescence assays detected P104 at the apical end of extracellular T. gondii. An Fc-fusion protein of the P104 N-terminus, which contains two PAN/apple domains, showed strong affinity for the mammalian and insect cells evaluated. This binding was not related to protein-protein or protein-lipid interactions, but to a protein-glycosaminoglycan (GAG) interaction. Chondroitin sulfate (CS), a kind of GAG, was shown to be involved in adhesion of the Fc-P104 N-terminus fusion protein to host cells. These results suggest that P104, expressed at the apical end of the extracellular parasite, may function as a ligand in the attachment of T. gondii to CS or other receptors on the host cell, facilitating invasion by the parasite

Measurement of Branching Fractions for B→ηcK(∗)B\to \eta_c K^{(*)} Decays

We report measurements of branching fractions for charged and neutral $B\to \eta_c K$ decays where the $\eta_c$ meson is reconstructed in the $K_S^0 K^{\pm}\pi^{\mp}, K^+ K^- \pi^0, K^{*0} K^-\pi^+$ and $p \bar{p}$ decay channels. The neutral $B^0$ channel is a CP eigenstate and can be used to measure the CP violation parameter $\sin 2\phi_1$. We also report the first observation of the $B^0\to \eta_c K^{*0}$ mode. The results are based on an analysis of 29.1 fb$^{-1}$ of data collected by the Belle detector at KEKB.Comment: To appear in Physical Review Letter

Search for the Electric Dipole Moment of the tau Lepton

We have searched for a CP violation signature arising from an electric dipole moment (d_tau) of the tau lepton in the e+e- -> tau+tau- reaction. Using an optimal observable method and 29.5 fb^{-1} of data collected with the Belle detector at the KEKB collider at sqrt{s} = 10.58 GeV, we find Re(d_tau) = (1.15 +- 1.70) x 10^{-17} ecm and Im(d_tau) = (-0.83 +- 0.86) x 10^{-17} ecm and set the 95% confidence level limits -2.2 < Re(d_tau) < 4.5 (10^{-17}ecm) and -2.5 < Im(d_tau) < 0.8 (10^{-17}ecm).Comment: 15 pages, LaTeX, 21 figures, submitted to Phys. Lett.

Observation of chi_c2 Production in B-meson Decay

We report the first observation of chi_c2 production in B-meson decays. We find an inclusive B -> chi_c2 X branching fraction of (1.80^{+0.23}_{-0.28}+/- 0.26) 10^-3. The data set, collected with the Belle detector at the KEKB e^+e^- collider, consists of 31.9 million B\bar B events. We also present branching fractions and momentum spectra for both chi_c1 and chi_c2 production.Comment: 5 pages with 2 figure

Measurement of the B0−Bˉ0B^0 -\bar{B}^0 mixing rate with B0(Bˉ0)→D∗∓π±B^0(\bar{B}^0) \to D^{*\mp} \pi^{\pm} partial reconstruction

We report a measurement of the $B^0-\bar{B}^0$ mixing parameter $\Delta m_d$ based on a $\rm 29.1~fb^{-1}$ sample of $\Upsilon (4S)$ resonance decays collected by the Belle detector at the KEKB asymmetric $e^+ e^-$ collider. We use events with a partially reconstructed $B^0(\bar{B}^0) \to D^{*\mp} \pi^{\pm}$ candidate and where the flavor of the accompanying $B$ meson is identified by the charge of the lepton from a $B^0(\bar{B}^0) \to X^{\mp} \ell^{\pm} \nu$ decay. The proper-time difference between the two $B$ mesons is determined from the distance between the two decay vertices. From a simultaneous fit to the proper-time distributions for the same-flavor ($B^0(\bar{B}^0)$, $\ell^{\pm}$) and opposite-flavor ($B^0(\bar{B}^0)$, $\ell^{\mp}$) event samples, we measure the mass difference between the two mass eigenstates of the neutral $B$ meson to be $\Delta m_d$= $(0.509 \pm 0.017~(\rm stat) \pm 0.020~(\rm syst))~ps^{-1}$.Comment: 16 pages, 14 figure

Study of Exclusive B decays to Charmed Baryons

Using 29.1fb-1 of data accumulated at the Upsilon(4S) with the Belle detector at KEKB, we have studied the decay modes B0bar->Lambda_c+ pbar pi+pi-, B- -> Lambda_c+ pbar pi-, and B0bar ->Lambda_c+ pbar. We report branching fractions of exclusive B decays to charmed baryons with four-, three- and two-body final states, including intermediate Sigma_c++ and Sigma_c0 states. We observed B0bar -> Sigma_c(2455)++pbar pi- for the first time with a branching fraction of (2.38+0.63-0.55+-0.41+-0.62)x10-4 and observed evidence for the two-body decay B- ->Sigma_c(2455)0 pbar with a branching fraction of (0.45+0.26-0.19+-0.07+-0.12)x10-4. We also set improved upper limits for the two-body decays B0bar -> Lambda_c+ pbar and B- -> Sigma_c(2520)0 pbar.Comment: accepted for publication in Phys. Rev.

Measurement of K^+K^- production in two-photon collisions in the resonant-mass region

K^+K^- production in two-photon collisions has been studied using a large data sample of 67 fb^{-1} accumulated with the Belle detector at the KEKB asymmetric e^+e^- collider. We have measured the cross section for the process gamma gamma -> K^+ K^- for center-of-mass energies between 1.4 and 2.4 GeV, and found three new resonant structures in the energy region between 1.6 and 2.4 GeV. The angular differential cross sections have also been measured.Comment: 24 pages, 8 figures, to appear in Euro. Phys. Jour.

Observation of Ds+ K- and evidence for Ds+ pi- final states in neutral B decays

We report the first observation of a B meson decay that is not accessible by a direct spectator process. The channel B0bar -> Ds+ K- is found in a sample of 85 timse 10^6 B Bbar events, collected with the Belle detector at KEKB, with a branching fraction Br(B0bar -> Ds+ K-)=(4.6^{+1.2}_{-1.1} +- 1.3) times 10^{-5}. We also obtain evidence for the B0 -> Ds+ pi- decay with branching fraction Br(B0 -> Ds+ pi-)=(2.4^{+1.0}_{-0.8} +- 0.7) times 10^{-5}. This value may be used to extract a model-dependent value of |Vub|.Comment: Accepted to publication in Phys. Rev. Let