Measurement of semileptonic B decays into orbitally excited charmed mesons

We present a study of B decays into semileptonic final states containing charged and neutral D1(2420) and D_{2};{*}(2460). The analysis is based on a data sample of 208 fb;{-1} collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. With a simultaneous fit to four different decay chains, the semileptonic branching fractions are extracted from measurements of the mass difference Deltam=m(D;{**})-m(D) distributions. Product branching fractions are determined to be B(B;{+}-->D_{1};{0}l;{+}nu_{l})xB(D_{1};{0}-->D;{*+}pi;{-})=(2.97+/-0.17+/-0.17)x10;{-3}, B(B;{+}-->D_{2};{*0}l;{+}nu_{l})xB(D_{2};{*0}-->D;{(*)+}pi;{-})=(2.29+/-0.23+/-0.21)x10;{-3}, B(B;{0}-->D_{1};{-}l;{+}nu_{l})xB(D_{1};{-}-->D;{*0}pi;{-})=(2.78+/-0.24+/-0.25)x10;{-3} and B(B;{0}-->D_{2};{*-}l;{+}nu_{l})xB(D_{2};{*-}-->D;{(*)0}pi;{-})=(1.77+/-0.26+/-0.11)x10;{-3}. In addition we measure the branching ratio Gamma(D_{2};{*}-->Dpi;{-})/Gamma(D_{2};{*}-->D;{(*)}pi;{-})=0.62+/-0.03+/-0.02.

Search for second-class currents in tau;{-} --> omegapi;{-}nu_{tau}

We report an analysis of tau;{-} decaying into omegapi;{-}nu_{tau} with omega --> pi;{+}pi;{-}pi;{0} using a data sample containing nearly 320 x 10;{6}tau pairs collected with the BABAR detector at the PEP-II B-Factory. We find no evidence for second-class currents, and we set an upper limit of 0.69% at 90% confidence level for the fraction of second-class currents in this decay mode.

Improved limits on lepton-flavor-violating tau decays to lphi, lrho, lK, and lK

We search for the neutrinoless, lepton-flavor-violating tau decays tau- -->l-}V0, where l is an electron or muon and V0 is a vector meson reconstructed as phi-->K+K-, rho-->pi+pi-, K-->K+pi-, K[over ]-->K-pi+. The analysis has been performed using 451 fb-1 of data collected at an e+e- center-of-mass energy near 10.58 GeV with the BABAR detector at the PEP-II storage rings. The number of events found in the data is compatible with the background expectation, and upper limits on the branching fractions are set in the range (2.6-19)x10-8 at the 90% confidence level.

A prospective, open-label, randomized phase II trial to evaluate the changes of bone resorption marker after administration of zoledronic acid (ZOL) in nasopharyngeal cancer (NPC) patients with bone metastases (BM)

6063

Background: ZOL is the only bisphosphonate that has demonstrated efficacy for the prevention of skeletal-related events (SREs) in patients with BM in a wide range of tumor types. Recent retrospective analyses also showed that normalization of N-telopeptide of type I collagen (NTX) over 3 months by the treatment of ZOL provided a continuum of SRE risk reduction and survival benefit in patients with BM (Lipton et al. ASCO 2007). Therefore, we conducted the prospective open-label randomized phase II trial to evaluate the changes of NTX after administration of ZOL in NPC patients with BM. Methods: Newly diagnosed NPC patients with BM were randomized to receive chemotherapy of cisplatin (20mg/m2 IV, D1–5) plus FU (500mg/m2 IV, D1–5) (CF regimen, q3wks) and intravenous ZOL (4mg, q4wks, for 3months, CF+ZOL Group) or the same chemotherapy alone (CF Group). Urinary NTX was measured by ELISA method (Coleman et al. JCO 2005) at baseline and 1, 2, 3 months after administration of ZOL in all patients. Results: Sixty patients were enrolled into the study, 30 patients in each group. The median chemotherapy cycles was the same (4 and 4, respectively) in two groups. The median baseline NTX level had no difference between the two groups (75.4 vs. 95.6 nM BCE/mM creatinine, respectively p>0.05). The NTX decreased 65.9% within 1 month in CF+ZOL group, whereas NTX increased 2.61 % in CF group (p<0.01). The median NTX decrease percentage in 2,3 months after treatment were 70.8%, 86.5% in CF+ZOL Group and 15.9%, 34.5% in CF Group respectively (p<0.01, p<0.01). Conclusions: ZOL administered with chemotherapy (CF) consistently reduced NTX levels in NPC patients with BM, indicating potential benefit of ZOL may exist in this group of patients. The value of NTX reduction in NPC patients with BM need to be further studied in larger prospective randomized trials.

[Table: see text]

[Table: see text]

Postlumpectomy loco-regional breast cancer therapy with liposomal therapeutic agents: Retention and distribution in nude rats

e11562

Background: Post-lumpectomy loco-regional radiation therapy, such as brachytherapy, has been shown to decrease breast cancer recurrence and increase patient survival. Limitations of current brachytherapy are the relatively high radiation absorbed dose delivered to normal breast and the inability to treat potentially involved lymph nodes. Locally administered liposomes are being investigated for delivery of drugs and therapeutic radionuclides. We propose a new post-lumpectomy loco-regional therapy with liposome-carried therapeutic agents. To investigate, radiolabeled liposomes were injected into the surgical cavity of a nude rat model one day following surgical removal of the breast tumor, and in vivo retention and distribution were monitored with nuclear imaging and post- mortem dissection. Methods: Six liposome formulations containing 0.2% molar ratio Rhodamine B-lipid and cationic, neutral, or anionic surface charges were manufactured at diameters of 400 or 100 nm and characterized. Breast cancer xenograft model in female nude rats was set up by inoculating MDA-MB-231 cells into the fat pad of the left breast of each rat. When tumor volumes reached 1.9 cm3 on average, the majority of each tumor was surgically removed, leaving ∼0.05 cm3 tumor tissue in the cavity. Then, each rat (3–4 rats/group) was intracavitarily injected with 0.5 ml of 99mTc-liposomes (4 mCi., 30 mg total lipids/kg body weight). In vivo distribution of 99mTc-activity was measured with planar gamma camera and SPECT imaging at various times. Post-mortem stereo fluorescent images of surgical cavity and the surrounding lymph nodes at 44 h were acquired. Results: All 99mTc-liposome formulations had approximately ≥ 50% retention in the surgical cavity at 44 h after injection. 99mTc-anionic liposomes of 100 nm diameter had an optimal lymph node targeting with ∼6%/g tissue in the surrounding lymph nodes at 44 h. Fluorescence imaging of the liposomes clearly showed their clearance through surrounding lymphatics and retention in lymph nodes. Conclusions: Anionic liposomes of 100 nm diameter are promising carriers for the simultaneous treatment of the surgical cavity and its draining lymph nodes.

No significant financial relationships to disclose.

Substantial stabilization of ferromagnetism in ZnO:Mn induced by N codoping

Electronic structures and magnetic properties of ZnO:Mn and ZnO:Mn+N systems are investigated using first-principles density functional calculations with generalized gradient approximation. The results provide a fundamental theoretical understanding in the substantial ferromagnetic stability induced by N codoping in the ZnO:Mn system observed experimentally. They demonstrate that the ferromagnetic interaction is due to the hybridization between N 2p and Mn 3d states and is very sensitive to the geometrical configurations of dopants in the ZnO host lattice. The most stable ferromagnetic configuration corresponds to the Mn-N-Mn cluster, energetically strong enough to lead to hole-mediated ferromagnetism at room temperature.

Isolation and aggregation of substituent Co in ZnO:Co diluted magnetic semiconductors

Distribution of magnetic ions in a semiconducting host is critical for the functionality of diluted magnetic semiconductors. By investigating the temperature- and field-dependent magnetization of single-phase polycrystalline ZnO:Co oxides, the substitution of Co at the Zn site is found not to occur randomly but Co ions appear to have a tendency for aggregation via oxygen with an antiferromagnetic coupling, in contrast to paramagnetic isolated free Co. The experimental findings are justified through first-principles density functional calculations based on the generalized gradient approximation. It suggests that Co dopants in ZnO:Co have a tendency towards staying close to each other along the ab plane.

Measurement of B-->Xgamma decays and determination of |Vtd/Vts|

Using a sample of 383 x 10;{6} BB[over ] events collected by the BABAR experiment, we measure sums of seven exclusive final states B-->X_{d(s)}gamma, where X_{d}(X_{s}) is a nonstrange (strange) charmless hadronic system in the mass range 0.6-1.8 GeV/c;{2}. After correcting for unmeasured decay modes in this mass range, we obtain a branching fraction for b-->dgamma of (7.2+/-2.7(stat)+/-2.3(syst))x10;{-6}. Taking the ratio of X_{d} to X_{s} we find Gamma(b-->dgamma)/Gamma(b-->sgamma)=0.033+/-0.013(stat)+/-0.009(syst), from which we determine |V_{td}/V_{ts}|=0.177+/-0.043.

Effects of core binding factor alpha1 or bone morphogenic protein-2 overexpression on osteoblast/cementoblast-related gene expressions in NIH3T3 mouse cells and dental follicle cells

OBJECTIVES

Bone morphogenic protein-2 (BMP-2) has long been used to promote bone and periodontal regeneration, while core binding factor alpha1 (CBFA1) plays important roles in both osteogenic differentiation and tooth morphogenesis. The aim of this study was to evaluate the effects of CBFA1 or BMP-2 overexpression on osteoblast/cementoblast-related gene expressions in NIH3T3 cells and dental follicle cells (DFCs).

MATERIALS AND METHODS

CBFA1 or BMP-2 overexpression in NIH3T3 and DFCs was achieved by infection with retroviral vectors containing CBFA1 or BMP-2 cDNA. Cells stably integrated with CBFA1 or BMP-2 cDNA were selected with G418 for 14 days. Western blotting, real-time reverse transcriptase-polymerase chain reaction, and in vitro mineralization assay were performed to evaluate effects of CBFA1 or BMP-2 overexpression in cells undergoing osteoblast/cementoblast differentiation.

RESULTS

Our results demonstrated that osteoblast/cementoblast-related gene expression levels in CBFA1-overexpressing NIH3T3 cells were higher than those in BMP-2-overexpressing cells. More mineral nodules were observed in CBFA1-overexpressing NIH3T3 cells than in BMP-2-overexpressing cells. CBFA1 overexpression in DFCs also increased osteoblast/cementoblast-related gene expression and promoted mineral nodule formation. However, no significant changes in gene expression levels nor mineral nodule formation were found in BMP-2-overexpressing DFCs when compared with empty vector transduced DFCs.

CONCLUSIONS

CBFA1 overexpression up-regulated expression levels of osteoblast/cementoblast-related genes and enhanced in vitro osteogenic differentiation more efficiently than BMP-2 in both NIH3T3 cells and DFCs.

Cocaine withdrawal enhances long-term potentiation in rat hippocampus via changing the activity of corticotropin-releasing factor receptor subtype 2

The neural plasticity mechanisms that underlie learning and memory may also be engaged when drug addiction occurs. It was reported that long-lasting neuroadaptations induced by cocaine use and withdrawal require the participation of hippocampus. However, the role of corticotrophin-releasing factor receptors in this process remains unclear. In the present study, the effects of chronic cocaine treatment (a 14-day cocaine administration, 20 mg/kg i.p., daily) and short-term cocaine withdrawal (a 3-day cocaine extinction following a 14-day cocaine administration) on long-term potentiation (LTP), one prominent cellular mechanism for learning and memory, were assessed in the CA1 region of the rat hippocampal slices. We found that cocaine withdrawal, but not the chronic cocaine administration itself, significantly enhanced the magnitude of LTP in hippocampal slices, as compared with that in saline controls. Selective blockade of corticotrophin-releasing factor receptor subtype 1 (CRF(1)) with the specific antagonist NBI 27914 (100 nM in vitro) attenuated the magnitude of LTP in hippocampal slices from cocaine withdrawal rats, and intriguingly, also from saline control rats, while specific blockade of corticotrophin-releasing factor receptor subtype 2 (CRF(2)) with astressin2-B (100 nM in vitro) selectively attenuated the magnitude of LTP in hippocampal slices from cocaine withdrawal rats. Our data suggest that short-term cocaine withdrawal treatment may cause synaptic plasticity in hippocampus partially via changing the activity of CRF(2) in the hippocampus.

Improved measurement of B+ --> rho+ rho0 and determination of the quark-mixing phase angle alpha

We present improved measurements of the branching fraction B, the longitudinal polarization fraction f{L}, and the direct CP asymmetry A{CP} in the B meson decay channel B;{+}-->rho;{+}rho;{0}. The data sample was collected with the BABAR detector at SLAC. The results are B(B;{+}-->rho;{+}rho;{0})=(23.7+/-1.4+/-1.4) x 10;{-6}, f{L}=0.950+/-0.015+/-0.006, and A{CP}=-0.054+/-0.055+/-0.010, where the uncertainties are statistical and systematic, respectively. Based on these results, we perform an isospin analysis and determine the Cabibbo-Kobayashi-Maskawa phase angle alpha=arg(-V{td}V{tb};/V{ud}V{ub}) to be (92.4{-6.5};{+6.0}) degrees.