Measurement of the WW production cross section with dilepton final states in pp collisions at square root(s) = 1.96 TeV and limits on anomalous trilinear gauge couplings

We provide the most precise measurement of the WW production cross section in pp collisions to date at a center of mass energy of 1.96 TeV, and set limits on the associated trilinear gauge couplings. The WW-->lnul'nu (l, l' = e, mu) decay channels are analyzed in 1 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. The measured cross section is sigma(pp --> WW) = 11.5+/-2.1(stat+syst)+/-0.7(lumi) pb. One- and two-dimensional 95% C.L. limits on trilinear gauge couplings are provided.

Induction of MMP-1 (collagenase-1) by relaxin in fibrocartilaginous cells requires both the AP-1 and PEA-3 promoter sites

OBJECTIVES - Relaxin induces the matrix metalloproteinase MMP-1 (collagenase-1) in TMJ fibrocartilaginous cells, and this response is potentiated by beta-estradiol. We identified the MMP-1 promoter sites and transcription factors that are induced by relaxin with or without beta-estradiol in fibrocartilaginous cells. MATERIAL AND METHODS - Early passage cells were transiently transfected with the pBLCAT2 plasmid containing specific segments of the human MMP-1 promoter regulating the chloramphenicol acyl transferase (CAT) gene and co-transfected with a plasmid containing the beta-galactosidase gene. The cells were cultured in serum-free medium alone or medium containing 0.1 ng/ml relaxin, or 20 ng/ml beta-estradiol or both hormones, and lysates assayed for CAT and beta-galactosidase activity. RESULTS - Cells transfected with the -1200/-42 or -139/-42 bp MMP-1 promoter-reporter constructs showed 1.5-fold and 3-fold induction of CAT by relaxin in the absence or presence of beta-estradiol, respectively. Relaxin failed to induce CAT in the absence of the -137/-69 region of the MMP-1 promoter, which contains the AP-1-and PEA3-binding sites. Using wild type or mutated minimal AP-1 and PEA-3 promoters we found that both these promoter sites are essential for the induction of MMP-1 by relaxin. The mRNAs for transcription factors c-fos and c-jun, which together form the AP-1 heterodimer, and Ets-1 that modulates the PEA-3 site, were upregulated by relaxin or beta-estradiol plus relaxin. CONCLUSION - These studies show that both the AP-1 and PEA-3 promoter sites are necessary for the induction of MMP-1 by relaxin in fibrocartilaginous cells.

Measurement of the W boson mass

We present a measurement of the W boson mass in W-->e(nu) decays using 1 fb-1 of data collected with the D0 detector during Run II of the Fermilab Tevatron collider. With a sample of 499830 W-->e(nu) candidate events, we measure M(W)=80.401+/-0.043 GeV. This is the most precise measurement from a single experiment.

Direct measurement of the mass difference between top and antitop quarks

We present a measurement of the mass difference between t and t[over] quarks in lepton + jets final states of tt[over] events in 1 fb;{-1} of data collected with the D0 detector from Fermilab Tevatron Collider pp[over] collisions at sqrt[s] = 1.96 TeV. The measured mass difference of 3.8 +/- 3.7 GeV is consistent with the equality of t and t[over ] masses. This is the first direct measurement of a mass difference between a quark and its antiquark partner.

Observation of single top-quark production

We report observation of the electroweak production of single top quarks in pp[over ] collisions at sqrt[s]=1.96 TeV based on 2.3 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of sigma(pp[over ]--> tb + X, tqb + X) = 3.94 + or - 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5 x 10(-7), corresponding to a 5.0 standard deviation significance for the observation.

Global microsatellite content distinguishes humans, primates, animals, and plants

Microsatellites are highly mutable, repetitive sequences commonly used as genetic markers, but they have never been studied en masse. Using a custom microarray to measure hybridization intensities of every possible repetitive nucleotide motif from 1-mers to 6-mers, we examined 25 genomes. Here, we show that global microsatellite content varies predictably by species, as measured by array hybridization signal intensities, correlating with established taxonomic relationships, and particular motifs are characteristic of one species versus another. For instance, hominid-specific microsatellite motifs were identified despite alignment of the human reference, Celera, and Venter genomic sequences indicating substantial variation (30-50%) among individuals. Differential microsatellite motifs were mainly associated with genes involved in developmental processes, whereas those found in intergenic regions exhibited no discernible pattern. This is the first description of a method for evaluating microsatellite content to classify individual genomes.

Search for dark photons from supersymmetric hidden valleys

We search for a new light gauge boson, a dark photon, with the D0 experiment. In the model we consider, supersymmetric partners are pair produced and cascade to the lightest neutralinos that can decay into the hidden sector state plus either a photon or a dark photon. The dark photon decays through its mixing with a photon into fermion pairs. We therefore investigate a previously unexplored final state that contains a photon, two spatially close leptons, and large missing transverse energy. We do not observe any evidence for dark photons and set a limit on their production.

Search for resonant pair production of neutral long-lived particles decaying to bb in pp collisions at square root(S)=1.96 TeV

We report on a first search for resonant pair production of neutral long-lived particles (NLLP) which each decay to a bb pair, using 3.6 fb(-1) of data recorded with the D0 detector at the Fermilab Tevatron collider. We search for pairs of displaced vertices in the tracking detector at radii in the range 1.6-20 cm from the beam axis. No significant excess is observed above background, and upper limits are set on the production rate in a hidden-valley benchmark model for a range of Higgs boson masses and NLLP masses and lifetimes.

Search for next-to-minimal supersymmetric Higgs bosons in the h --> aa --> micromicromicromicro, micromicrotautau channels using pp[over] collisions at sqrt[s] = 1.96 TeV

We report on a first search for production of the lightest neutral CP-even Higgs boson (h) in the next-to-minimal supersymmetric standard model, where h decays to a pair of neutral pseudoscalar Higgs bosons (a), using 4.2 fb;{-1} of data recorded with the D0 detector at Fermilab. The a bosons are required to either both decay to micro;{+}micro;{-} or one to micro;{+}micro;{-} and the other to tau;{+}tau;{-}. No significant signal is observed, and we set limits on its production as functions of M_{a} and M_{h}.

Alterations of immune functions induced by 12C6+ ion irradiation in mice

PURPOSE

To estimate the biological risks to the immune system of the type of space radiation, 12C6+, encountered by cosmonauts during long-term travel in space.

MATERIALS AND METHODS

The Kun-Ming strain mice were whole-body irradiated by 12C6+ ion with 0, 0.01, 0.05, 0.075, 0.2, 0.3, 0.5, 0.75, 1 or 2 Gy, at a dose rate of 1 Gy/min. At 35 days after irradiation, the thymus and spleen weights were measured, the natural killer (NK) cells activity of spleen was determined by 3-(4, 5-dimethylthiazol-2-yl)- 2, 5-diphenyl tetrazolium bromide (MTT), and the interferon-gamma (IFN-gamma) levels in serum and thymus were detected with enzyme-linked immunosorbent assays (ELISA).

RESULTS

The results showed that the thymus weight, IFN-gamma levels in serum and the activity of splenic NK-cells had significantly increased at a dose of 0.05 Gy. With further dose increase, the weight of spleen continued to increase but the weight of thymus, IFN-gamma level and NK-cells activity declined.

CONCLUSIONS

These results suggest that the dose of 0.05 Gy irradiation has a stimulatory effect on mouse immunity; this effect declined with increasing dose.

Search for the standard model Higgs boson in tau final states

We present a search for the standard model Higgs boson using hadronically decaying tau leptons, in 1 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp collider. We select two final states: tau+/- plus missing transverse energy and b jets, and tau+ tau- plus jets. These final states are sensitive to a combination of associated W/Z boson plus Higgs boson, vector boson fusion, and gluon-gluon fusion production processes. The observed ratio of the combined limit on the Higgs production cross section at the 95% C.L. to the standard model expectation is 29 for a Higgs boson mass of 115 GeV.

Inhibition of Akt sensitises neuroblastoma cells to gold(III) porphyrin 1a, a novel antitumour drug induced apoptosis and growth inhibition

BACKGROUND

Gold(III) porphyrin 1a is a new class of anticancer drug, which inhibits cell proliferation of wide range of human cancer cell lines and induces apoptosis in human nasopharyngeal carcinoma cells. However, the underlying signalling mechanism by which gold(III) porphyrin 1a modifies the intracellular apoptosis pathways in tumour cells has not been explained in detail in neuroblastoma cells.

METHODS

Cell proliferation and apoptosis were determined by measuring 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Annexin V binding, respectively. Western blot assay was used to detect proteins involved in apoptotic and Akt pathways. In vivo tumour growth was assessed by inoculating tumour cells to nude mice subcutaneously, and gold(III) porphyrin 1a was administrated intravenously.

RESULTS

This study assessed the antitumour effect and mechanism of gold(III) porphyrin 1a on neuroblastoma in vitro and in vivo. Gold(III) porphyrin 1a displayed a growth inhibition and induction of apoptosis in neuroblastoma cells effectively in vitro, which was accompanied with release of cytochrome c and Smac/DIABLO and caspases activation. Further studies indicated that gold(III) porphyrin 1a inhibited X-linked inhibitor of apoptosis (XIAP). However, we found that gold(III) porphyrin 1a can induce a survival signal, Akt activation within minutes and could last for at least 24 h. To further confirm association between activation of Akt and the effectiveness of gold(III) porphyrin 1a, neuroblastoma cells were treated with API-2, an Akt-specific inhibitor. API-2 sensitised cells to gold(III) porphyrin 1a-induced apoptosis and growth inhibition.

CONCLUSION

These results suggested that Akt may be considered as a molecular 'brake' that neuroblastoma cells rely on to slow down gold(III) porphyrin 1a-induced apoptosis and antiproliferation. Gold(III) porphyrin 1a is a mitochondrial apoptotic stimulus but also activates Akt, suggesting an involvement of Akt in mediating the effectiveness to growth inhibition and apoptosis by gold(III) porphyrin 1a and that inhibition of Akt can enhance the anticancer activity of gold(III) porphyrin 1a in neuroblastoma.

Search for resonant diphoton production with the D0 detector

We present a search for a narrow resonance in the inclusive diphoton final state using approximately 2.7 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp Collider. We observe good agreement between the data and the background prediction, and set the first 95% C.L. upper limits on the production cross section times the branching ratio for decay into a pair of photons for resonance masses between 100 and 150 GeV. This search is also interpreted in the context of several models of electroweak symmetry breaking with a Higgs boson decaying into two photons.

Measurement of the Zgamma --> nunu[over ]gamma production cross section and limits on anomalous ZZgamma and Zgammagamma couplings in pp[over] collisions at sqrt[s] = 1.96 TeV

We present the first observation of the Zgamma --> nunu[over ]gamma process at the Fermilab Tevatron at 5.1 standard deviations significance, based on 3.6 fb;{-1} of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp[over ] Collider at sqrt[s] = 1.96 TeV. The measured Zgamma production cross section multiplied by the branching fraction of Z --> nunu[over] is 32 +/- 9(stat + syst) +/-2 (lumi) fb for the photon E_{T} > 90 GeV. It is in agreement with the standard model prediction of 39 +/- 4 fb. We set limits on anomalous trilinear Zgammagamma and ZZgamma gauge boson couplings, most of which are the most restrictive to date.

ERCC-1 (E) expression and its effect on survival in patients (pts) receiving concurrent cisplatin (C) and radiation (R) for locally advanced head and neck cancer (HNC)

e17033

Background: E is a DNA repair gene involved in the nucleotide excision repair pathway. Overexpression of E has been associated with resistance to C in patients with ovarian, gastric, and lung cancer. We retrospectively analyzed tissue from HNC pts who received concurrent C and R to determine if E expression was a significant independent predictor of survival. Methods: Eligible HNC pts had squamous cell histology and received definitive concurrent C and R at the Dallas VAMC. Tissue was immunostained for E using ERCC-1,clone 8F, 1:100 dilution (Abcam, Cat#ab2356, Cambridge, MA) diluted in ChemMate buffer (Ventana Medical Systems, Tucson, AZ) on a BenchMarkXT automated immunostainer using the UltraVIEW system with horseradish peroxidase and diaminobenzidine (DAB) chromogen (Ventana Medical Systems, Tucson, AZ) per the standard protocol of the UT Southwestern Pathology Immunohistochemistry Laboratory. E scoring was determined by 2 pathologists blinded to clinical outcomes. Scoring was as follows: 0 = 0% of tumor nuclei were positive, 1+ = less than 50%, 2+ = 50–75% and 3+ = 75–100%. Results: 73 consecutively treated patients were analyzed. Median age 59 (range 41 - 80); 99% male; 7% stage II, 19% stage III, 73% stage IV; primary site - 4% oral cavity, 56% oropharynx, 14% hypopharynx, 23% larynx, 3% nasopharynx; Tumor grade - 60% moderately differentiated, 4% well differentiated, 15% poorly differentiated, 21% not specified; Performance status 0–25%, 1–45%, 2–8%, unknown-22%; E scoring was 0 in 0%, 1+ (14%), 2+ (42%), 3+ (44%). In univariate analysis, E staining 3+ was not predictive of survival with a hazard ratio (HR) of .796 (95% CI .44–1.43; p = 0.44). In multivariate analysis, the only significant predictor was hypopharynx with a HR of 3.18 (95% CI 1.02–9.88; p = 0.046). HR for age > 60 was 2.16 (95% CI .96–4.86; p = 0.06). E staining 3+ was not predictive of survival with a HR of .69 (95% CI .3–1.56; p = 0.37). Median survival (MS) for the whole group was 2.8 years (y); 5y survival - 41%. MS for the E 3+ pts - 2.1y; 5y survival 38%. MS for the E < 3+ pts - 2.9y; 5y survival 44% (p = not significant). Conclusions: In our retrospective review of HNC patients receiving concurrent C and R, E staining was not a significant predictor of survival.

No significant financial relationships to disclose.

Towards adaptive radiation therapy: Image-based tumor shrinkage modeling in head and neck cancer

e17050

Background: Understanding the kinetics of tumor growth/shrinkage represents a critical step in quantitative assessment of therapeutics and realization of adaptive radiation therapy. We established a novel framework for image-based modeling of tumor change and demonstrate its performance with a number of synthetic images and clinical cases. Methods: Due to the nonconservation of tissue, similarity-based deformable models are not suitable for describing the tumor growth/shrinkage process. Under the hypothesis that the tissue features in the tumor volume or the boundary region are partially preserved, we model the tumor kinetics by a two-step procedure: (1) auto-detection of homologous tissue features shared by the planning CT and subsequent on-treatment CBCT images using the Scale Invariance Feature Transformation (SIFT) method; (2) establishment of voxel-to-voxel correspondence between two input images for the remaining spatial points by a basis spline interpolation. The correctness of the tissue feature correspondence is doubly assured by a bi-directional association procedure, in which the SIFT features are mapped from planning CT to CBCT and reversely. Only the associations common to both mappings are used in Thin Plate Spline (TPS) interpolation. A synthetic digital phantom experiment and five clinical head and neck cases are used to assess the performance of the proposed technique. Results: Image contents of the digital phantoms are modified in various ways. It is found the proposed technique can identify any of the changes faithfully. The subsequent feature-guided TPS interpolation reproduces the “ground truth” with an accuracy better than 1.3mm. For the clinical cases, the new algorithm works reliably for a volume change less than 30%, suggesting the time span between two consequent imaging sessions should not be unreasonably far away in order for the model to function properly. Conclusions: An image-based tumor kinetic model has been developed to better understand the tumor response to radiation therapy. The technique provides a solid foundation for future head-and-neck adaptive radiation therapy.

No significant financial relationships to disclose.

A multicenter phase II study of pemetrexed (P), cisplatin (C), and bevacizumab (B) in patients (pts) with advanced malignant mesothelioma (MM)

7578

Background: Vascular endothelial growth factor (VEGF) is a key growth factor for MM. In pre-clinical models, anti-VEGF antibodies inhibit MM proliferation. Standard chemotherapy for MM, pemetrexed + cisplatin, yields a response rate of 41%, progression-free survival (PFS) of 5.7 months (mo) and median overall survival (OS) of 12.1 mo. We added the anti-VEGF antibody B to PC in an ongoing phase II multi-center study in MM pts. Methods: Eligible pts have unresectable, histologically-confirmed MM, no prior chemotherapy, and PS 0–1. Pts receive C 75 mg/m2, P 500 mg/m2 and B 15 mg/kg Q21 days for 6 cycles, then B Q21 days until progression. CT scans are obtained Q 2 cycles. Primary endpoint: Progression-fere survival (PFS). Correlative studies include IHC for the VEGF/KDR complex and PCR for simian virus 40 (sv40) T antigen. Results: 43 pts enrolled at 4 centers from 3/06 to 12/08; currently, 34 are evaluable for PFS and 36 for toxicity. Pt characteristics: male 88%; median age 66 (range 24–81); histology: epithelial 62%, sarcomatoid 15%, biphasic 20%, unknown 3%; site of origin: pleural 85%, peritoneal 12%, tunica vaginalis 3%; PS 0 32%, PS 1 68%; thrombocytosis (>400) 32%. Cycles administered 229 (median 4, range 1–18). Grade 3/4 toxicity (%pts): neutropenia 8%; anemia 0%; thrombocytopenia 3%; thrombosis 11%; hypertension 8%; vomiting 8%; mucositis 6%; CVA 3%; proteinuria 0%; perforation 0%. Partial response: 41%, stable disease: 35%. Median PFS: 5.6 mo (95% CI: 4.1, 7.2). Median OS 11.5 mo (95% CI: 9.4, 24). Conclusions: These data suggest that the addition of B to PC does not improve PFS when compared with historical controls of PC in advanced MM pts. Correlative studies evaluating the VEGF/KDR complex and sv40 T antigen are pending.

[Table: see text]

The association between clinical characteristics, treatment modality, and outcomes of non-small cell lung cancer

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Background: Non-small cell lung cancer (NSCLC) remains the leading cause of cancer death in the United States. NSCLC outcomes vary widely among patients. The degree to which these disparate outcomes reflect differences in treatment modality remains unclear. We therefore examined these associations at a medical center providing care to a diverse patient population. Methods: We performed a retrospective analysis of consecutive patients diagnosed with NSCLC stages I-III from 2000 to 2005 at the University of Texas Southwestern Medical Center. We recorded patient, disease, and treatment characteristics. The association between these characteristics and outcome was assessed using univariate analysis, multivariate logistic regression, and survival analysis. Results: A total of 482 patients met criteria for analysis. Mean age was 64 y, and 52 percent were men. For stage I/II disease, median survival was 6.7 y for patients aged < 65 y vs 4.4 y for age ≥ 65 y (P=0.01); 3.1 y for men vs >5.8 y for women (P=0.0002); 5.6 y for patients with household income below the national median ($41,995) vs 5.6 y for above-median income (P not significant). For stage III, median survival was 1.1 y for age < 65 y vs 0.7 y for age ≥ 65 y (P=0.02); 0.8 y for men vs 1.2 y for women (P=0.02); 0.7 y for below-median income vs 1.2 y for above-median income (P=0.02). Race and hospital setting (public versus private) were not associated with survival. For stage I/II, patients treated with surgery had a median survival of 5.8 y, vs 1.7 y for non-surgical treatment (P<0.0001). For stage III, patients who received surgery and/or radiation had a median survival of 1.2 y vs 0.5 y for other patients (P<0.0001). For stage I/II, treatment modality was associated with hospital setting, race, and income. For stage III, treatment modality was associated with age, gender, hospital setting, race, and income. In multivariate analysis, age (for stage I/II), gender (for stage I/II), and treatment modality (for all stages) were associated with survival. Conclusions: For stages I-III NSCLC, a number of clinical characteristics are associated with outcomes. Differences in treatment modality may account in part for these disparities. These findings warrant further study.

No significant financial relationships to disclose.