Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Immunohistochemical Detection of MYC-driven Diffuse Large B-Cell Lymphomas

Diffuse large B cell lymphoma (DLBCL) is a clinically and genetically heterogeneous disease. A small subset of DLBCLs has translocations involving the MYC locus and an additional group has a molecular signature resembling Burkitt lymphoma (mBL). Presently, identification of such cases by morphology is unreliable and relies on cytogenetic or complex molecular methods such as gene transcriptional profiling. Herein, we describe an immunohistochemical (IHC) method for identifying DLBCLs with increased MYC protein expression. We tested 77 cases of DLBCL and identified 15 cases with high MYC protein expression (nuclear staining in >50% of tumor cells). All MYC translocation positive cases had increased MYC protein expression by this IHC assay. In addition, gene set enrichment analysis (GSEA) of the DLBCL transcriptional profiles revealed that tumors with increased MYC protein expression (regardless of underlying MYC translocation status) had coordinate upregulation of MYC target genes, providing molecular confirmation of the IHC results. We then generated a molecular classifier derived from the MYC IHC results in our cases and employed it to successfully classify mBLs from two previously reported independent case series, providing additional confirmation that the MYC IHC results identify clinically important subsets of DLBCLs. Lastly, we found that DLBCLs with high MYC protein expression had inferior overall survival when treated with R-CHOP. In conclusion, the IHC method described herein can be used to readily identify the biologically and clinically distinct cases of MYC-driven DLBCL, which represent a clinically significant subset of DLBCL cases due to their inferior overall survival

Quantifying the effect of population mixing on childhood leukaemia risk: the Seascale cluster

A statistical model was developed based on Poisson regression of incidence of childhood leukaemia and non-Hodgkin’s lymphoma (NHL) in relation to population mixing among all 119 539 children born 1969–1989 to mothers living in Cumbria, north-west England, (excluding Seascale). This model was used to predict the number of cases in Seascale (the village adjacent to the Sellafield nuclear installation) children, born 1950–1989 and diagnosed before 1993. After allowing for age, the incidence of acute lymphoblastic leukaemia (ALL) and NHL was significantly higher among children born in areas with the highest levels of population mixing, relative risk (RR) = 11.7 (95% confidence interval (CI) 3.2–43) and was highest among children of incomers. The model predicted up to 3.0 (95% CI 1.3–6.0) cases of ALL/NHL in children born in Seascale compared to six observed and 2.0 (95% CI 1.0–3.4) cases in children resident, but not born, in Seascale compared to two observed. Population mixing is a significant risk factor for ALL/NHL, especially in young children, accounting for over 50% of cases in Cumbria and most cases in Seascale. © 1999 Cancer Research Campaig

Bone involvement in young patients with non-Hodgkin's lymphoma: efficacy of chemotherapy without local radiotherapy

Of 95 young non-Hodgkin's lymphoma patients entered consecutively on the National Cancer Institute (NCI) Protocol 7704, 26 (27.4%) had involvement of one or more bones. The mean age of these 26 patients was 16.6 years, and the male to female ratio was 3.3:1. Tumor histology included undifferentiated Burkitt's lymphoma in 12, undifferentiated non-Burkitt's lymphoma in two, undifferentiated, unspecified lymphoma in one, diffuse large cell lymphoma in three, and lymphoblastic lymphoma in eight patients. Most had extensive disease; two patients had isolated bone lesions, one had lesions of two bones without involvement of other tissues, and 23 had either multiple bone lesions or single bone lesions with involvement of other tissues. Eight of the 26 patients had bone marrow involvement. Of a subgroup of 12 patients with jaw disease, 11 had undifferentiated lymphoma and one had diffuse large cell lymphoma. Only one had primary a jaw tumor, with two quadrants of the jaw involved. All 26 patients were treated with chemotherapy; only two received radiotherapy initially for bone lesions. Predicted survival of the 26 patients at 5 years is 53.2%. The 12 patients who remain disease free have a mean survival of 62.1 months (range, 22 to 100 months). Our results call into question the role of radiotherapy in the treatment of bone lesions in non-Hodgkin's lymphoma.</jats:p

Bone involvement in young patients with non-Hodgkin's lymphoma: efficacy of chemotherapy without local radiotherapy

Abstract Of 95 young non-Hodgkin's lymphoma patients entered consecutively on the National Cancer Institute (NCI) Protocol 7704, 26 (27.4%) had involvement of one or more bones. The mean age of these 26 patients was 16.6 years, and the male to female ratio was 3.3:1. Tumor histology included undifferentiated Burkitt's lymphoma in 12, undifferentiated non-Burkitt's lymphoma in two, undifferentiated, unspecified lymphoma in one, diffuse large cell lymphoma in three, and lymphoblastic lymphoma in eight patients. Most had extensive disease; two patients had isolated bone lesions, one had lesions of two bones without involvement of other tissues, and 23 had either multiple bone lesions or single bone lesions with involvement of other tissues. Eight of the 26 patients had bone marrow involvement. Of a subgroup of 12 patients with jaw disease, 11 had undifferentiated lymphoma and one had diffuse large cell lymphoma. Only one had primary a jaw tumor, with two quadrants of the jaw involved. All 26 patients were treated with chemotherapy; only two received radiotherapy initially for bone lesions. Predicted survival of the 26 patients at 5 years is 53.2%. The 12 patients who remain disease free have a mean survival of 62.1 months (range, 22 to 100 months). Our results call into question the role of radiotherapy in the treatment of bone lesions in non-Hodgkin's lymphoma.</jats:p

HL-A and Burkitt's tumour--a study in Uganda.

Thirty-one Burkitt's patients and forty-eight matched controls from Uganda were HL-A typed to investigate possible antigen frequency differences which could suggest association of an HL-A antigen with disease susceptibility. Cells were shipped in tissue culture medium from Uganda to Oxford where they were HL-A typed using sera from the Fifth International Histocompatibility Workshop in the cytotoxic fluorochromatic assay. No significant frequency differences between patients and control were found

HL-A and Burkitt's tumour--a study in Uganda.

Thirty-one Burkitt's patients and forty-eight matched controls from Uganda were HL-A typed to investigate possible antigen frequency differences which could suggest association of an HL-A antigen with disease susceptibility. Cells were shipped in tissue culture medium from Uganda to Oxford where they were HL-A typed using sera from the Fifth International Histocompatibility Workshop in the cytotoxic fluorochromatic assay. No significant frequency differences between patients and control were found