Pathogenic Aβ A2V versus protective Aβ A2T mutation : early stage aggregation and membrane interaction

We investigated the effects of punctual A-to-V and A-to-T mutations in the amyloid precursor protein APP, corresponding to position 2 of A\u3b21\u201342. Those mutations had opposite effects on the onset and progression of Alzheimer disease, the former inducing early AD pathology and the latter protecting against the onset of the disease. We applied Static and Dynamic Light Scattering and Circular Dichroism, to study the different mutants in the early stages of the aggregation process, essential for the disease. Comparative results showed that the aggregation pathways differ in the kinetics and extent of the process, in the size of the aggregates and in the evolution of the secondary structure, resulting in fibrils of different morphology, as seen by AFM. Mutated peptides had comparable toxic effects on N2a cells. Moreover, as assessed by X-ray scattering, all of them displayed disordering effects on the internal structure of mixed phospholipids-gangliosides model membranes

Connective tissue anomalies in patients with spontaneous cervical artery dissection.

OBJECTIVE: To investigate the prevalence of connective tissue abnormalities in patients with spontaneous cervical artery dissections (sCeAD). METHODS: We systematically assessed clinically detectable signs of connective tissue aberration in a series of consecutive patients with sCeAD and of age- and sex-matched patients with ischemic stroke unrelated to CeAD (non-CeAD IS) by a standard examination protocol including 68 items, and performed extensive molecular investigation for hereditary connective tissue disorders in all patients with sCeAD. RESULTS: The study group included 84 patients with sCeAD (mean age, 44.5 ± 7.8 years; 66.7% men) and 84 patients with non-CeAD IS. None of the patients with sCeAD met clinical or molecular diagnostic criteria for established hereditary connective tissue disorder. Connective tissue abnormalities were detected more frequently in the group of patients with sCeAD than in the group of those with non-CeAD IS (mean number of pathologic findings, 4.5 ± 3.5 vs 1.9 ± 2.3; p < 0.001). Eighty-one patients (96.4%) in the sCeAD group had at least one detectable sign compared with 55 patients (66.7%) in the group with non-CeAD IS (p < 0.001). Skeletal, ocular, and skin abnormalities, as well as craniofacial dysmorphisms, were the clinical signs more strongly associated with sCeAD. Signs suggesting connective tissue abnormality were also more frequently represented in patients with sCeAD than in patients with traumatic CeAD (28.6%, p < 0.001; mean number of pathologic findings, 1.7 ± 3.7, p = 0.045). CONCLUSIONS: Connective tissue abnormalities are frequent in patients with sCeAD. This reinforces the hypothesis that systemic aberrations of the connective tissue might be implicated in the pathogenesis of the disease

Antithrombotic medications and the etiology of intracerebral hemorrhage: MUCH-Italy.

23noOBJECTIVE: To test the hypothesis that the effect of antithrombotic medications on the risk of intracerebral hemorrhage (ICH) varies according to the location of the hematoma. METHODS: Consecutive patients with ICH were enrolled as part of the Multicenter Study on Cerebral Hemorrhage in Italy (MUCH-Italy). Multivariable logistic regression models served to examine whether risk factors for ICH and location of the hematoma (deep vs lobar) predict treatment-specific ICH subgroups (antiplatelets-related ICH and oral anticoagulants [OACs]-related ICH). RESULTS: A total of 870 (313 lobar ICH, 557 deep ICH) subjects were included. Of these, 223 (25.6%) were taking antiplatelets and 77 (8.8%) OACs at the time of stroke. The odds of antiplatelet-related ICH increased with aging (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.03-1.07) and hypertension (OR 1.86; 95% CI 1.22-2.85) but had no relation with the anatomical location of ICH. Conversely, lobar location of the hematoma was associated with the subgroup of OAC-related ICH (OR 1.70; 95% CI 1.03-2.81) when compared to the subgroup of patients taking no antithrombotic medications. Within the subgroup of patients taking OACs, international normalized ratio (INR) values were higher in those with lobar ICH as compared to those with deep ICH (2.8 ± 1.1 vs 2.2 ± 0.8; p = 0.011). The proportion of patients with lobar hematoma increased with increasing intensity of anticoagulation, with a ∼2-fold increased odds of lobar compared to deep ICH (odds 2.17; p = 0.03) in those exposed to overanticoagulation (INR values >3.0). CONCLUSIONS: OACs, as opposed to antiplatelets, predispose to lobar location of brain hematomas according to a dose-response relationship.openopenPezzini, A; Grassi, M; Paciaroni, M; Zini, A; Silvestrelli, G; Del Zotto, E; Caso, V; Dell'Acqua, Ml; Giossi, A; Volonghi, I; Simone, Am; Lanari, A; Costa, P; Poli, L; Morotti, A; De Giuli, V; Pepe, D; Gamba, M; Ciccone, A; Ritelli, M; Colombi, M; Agnelli, G; Padovani, APezzini, Alessandro; Grassi, M; Paciaroni, M; Zini, A; Silvestrelli, G; Del Zotto, E; Caso, V; Dell'Acqua, Ml; Giossi, A; Volonghi, I; Simone, Am; Lanari, A; Costa, P; Poli, L; Morotti, A; De Giuli, V; Pepe, D; Gamba, M; Ciccone, A; Ritelli, M; Colombi, Marina; Agnelli, G; Padovani, Alessandr

Measurement of the Branching Fraction for B- --> D0 K*-

We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid Communications

Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction

We present evidence for the flavor-changing neutral current decay $B\to K^*\ell^+\ell^-$ and a measurement of the branching fraction for the related process $B\to K\ell^+\ell^-$, where $\ell^+\ell^-$ is either an $e^+e^-$ or $\mu^+\mu^-$ pair. These decays are highly suppressed in the Standard Model, and they are sensitive to contributions from new particles in the intermediate state. The data sample comprises $123\times 10^6$ $\Upsilon(4S)\to B\bar{B}$ decays collected with the Babar detector at the PEP-II $e^+e^-$ storage ring. Averaging over $K^{(*)}$ isospin and lepton flavor, we obtain the branching fractions ${\mathcal B}(B\to K\ell^+\ell^-)=(0.65^{+0.14}_{-0.13}\pm 0.04)\times 10^{-6}$ and ${\mathcal B}(B\to K^*\ell^+\ell^-)=(0.88^{+0.33}_{-0.29}\pm 0.10)\times 10^{-6}$, where the uncertainties are statistical and systematic, respectively. The significance of the $B\to K\ell^+\ell^-$ signal is over $8\sigma$, while for $B\to K^*\ell^+\ell^-$ it is $3.3\sigma$.Comment: 7 pages, 2 postscript figues, submitted to Phys. Rev. Let

A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S)

We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 ${\rm fb}^{-1}$ recorded at the $\Upsilon(4S)$ resonance and 3.9 ${\rm fb}^{-1}$ off-resonance. One of the neutral B mesons, which are produced in pairs at the $\Upsilon(4S)$, is fully reconstructed in the CP decay modes $J/\psi K^0_S$, $\psi(2S) K^0_S$, $\chi_{c1} K^0_S$, $J/\psi K^{*0}$ ($K^{*0}\to K^0_S\pi^0$) and $J/\psi K^0_L$, or in flavor-eigenstate modes involving $D^{(*)}\pi/\rho/a_1$ and $J/\psi K^{*0}$ ($K^{*0}\to K^+\pi^-$). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. A maximum-likelihood fit to this flavor eigenstate sample finds $\Delta m_d = 0.516\pm 0.016 {\rm (stat)} \pm 0.010 {\rm (syst)} {\rm ps}^{-1}$. The value of the asymmetry amplitude $\sin2\beta$ is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged $B^0$ decays in the CP-eigenstate modes. We find $\sin2\beta=0.59\pm 0.14 {\rm (stat)} \pm 0.05 {\rm (syst)}$, demonstrating that CP violation exists in the neutral B meson system. (abridged)Comment: 58 pages, 35 figures, submitted to Physical Review

Measurement of the quasi-elastic axial vector mass in neutrino-oxygen interactions

The weak nucleon axial-vector form factor for quasi-elastic interactions is determined using neutrino interaction data from the K2K Scintillating Fiber detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of which half are charged-current quasi-elastic interactions nu-mu n to mu- p occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for oxygen and assume the form factor is approximately a dipole with one parameter, the axial vector mass M_A, and fit to the shape of the distribution of the square of the momentum transfer from the nucleon to the nucleus. Our best fit result for M_A = 1.20 \pm 0.12 GeV. Furthermore, this analysis includes updated vector form factors from recent electron scattering experiments and a discussion of the effects of the nucleon momentum on the shape of the fitted distributions.Comment: 14 pages, 10 figures, 6 table

Study of e+e- --> pi+ pi- pi0 process using initial state radiation with BABAR

The process e+e- --> pi+ pi- pi0 gamma has been studied at a center-of-mass energy near the Y(4S) resonance using a 89.3 fb-1 data sample collected with the BaBar detector at the PEP-II collider. From the measured 3pi mass spectrum we have obtained the products of branching fractions for the omega and phi mesons, B(omega --> e+e-)B(omega --> 3pi)=(6.70 +/- 0.06 +/- 0.27)10-5 and B(phi --> e+e-)B(phi --> 3pi)=(4.30 +/- 0.08 +/- 0.21)10-5, and evaluated the e+e- --> pi+ pi- pi0 cross section for the e+e- center-of-mass energy range 1.05 to 3.00 GeV. About 900 e+e- --> J/psi gamma --> pi+ pi- pi0 gamma events have been selected and the branching fraction B(J/psi --> pi+ pi- pi0)=(2.18 +/- 0.19)% has been measured.Comment: 21 pages, 37 postscript figues, submitted to Phys. Rev.

Measurement of Branching Fraction and Dalitz Distribution for B0->D(*)+/- K0 pi-/+ Decays

We present measurements of the branching fractions for the three-body decays B0 -> D(*)-/+ K0 pi^+/-$and their resonant submodes$B0 -> D(*)-/+ K*+/- using a sample of approximately 88 million BBbar pairs collected by the BABAR detector at the PEP-II asymmetric energy storage ring. We measure: B(B0->D-/+ K0 pi+/-)=(4.9 +/- 0.7(stat) +/- 0.5 (syst)) 10^{-4} B(B0->D*-/+ K0 pi+/-)=(3.0 +/- 0.7(stat) +/- 0.3 (syst)) 10^{-4} B(B0->D-/+ K*+/-)=(4.6 +/- 0.6(stat) +/- 0.5 (syst)) 10^{-4} B(B0->D*-/+ K*+/-)=(3.2 +/- 0.6(stat) +/- 0.3 (syst)) 10^{-4} From these measurements we determine the fractions of resonant events to be : f(B0-> D-/+ K*+/-) = 0.63 +/- 0.08(stat) +/- 0.04(syst) f(B0-> D*-/+ K*+/-) = 0.72 +/- 0.14(stat) +/- 0.05(syst)Comment: 7 pages, 3 figures submitted to Phys. Rev. Let