58 research outputs found
Effect of surgical treatment on the cellular immune response of gastric cancer patients
Patients with gastric cancer have a variety of immunological abnormalities. In the present study the lymphocytes and their subsets were determined in the peripheral blood of patients with gastric cancer (N = 41) both before and after surgical treatment. The percent of helper/inducer CD4 T cells (43.6 ± 8.9) was not different after tumor resection (43.6 ± 8.2). The percent of the cytotoxic CD8+ T cell population decreased significantly, whether patients were treated surgically (27.2 ± 5.8%, N = 20) or not (27.3 ± 7.3%, N = 20) compared to individuals with inflammatory disease (30.9 ± 7.5%) or to healthy individuals (33.2 ± 7.6%). The CD4/CD8 ratio consequently increased in the group of cancer patients. The peripheral blood lymphocytes of gastric cancer patients showed reduced responsiveness to mitogens. The defective blastogenic response of the lymphocytes was not associated with the production of transforming growth factor beta (TGF-ß) since the patients with cancer had reduced production of TGF-ß1 (269 ± 239 pg/ml, N = 20) in comparison to the normal individuals (884 ± 175 pg/ml, N = 20). These results indicate that the immune response of gastric cancer patients was not significantly modified by surgical treatment when evaluated four weeks after surgery and that the immunosuppression observed was not due to an increase in TGF-ß1 production by peripheral leukocytes.33934
Electroweak Radiative Corrections to Neutral-Current Drell-Yan Processes at Hadron Colliders
We calculate the complete electroweak O(alpha) corrections to pp, pbar p ->
l+l- X (l=e, mu) in the Standard Model of electroweak interactions. They
comprise weak and photonic virtual one-loop corrections as well as real photon
radiation to the parton-level processes q bar q -> gamma,Z -> l+l-. We study in
detail the effect of the radiative corrections on the l+l- invariant mass
distribution, the cross section in the Z boson resonance region, and on the
forward-backward asymmetry, A_FB, at the Fermilab Tevatron and the CERN Large
Hadron Collider. The weak corrections are found to increase the Z boson cross
section by about 1%, but have little effect on the forward-backward asymmetry
in the Z peak region. Threshold effects of the W box diagrams lead to
pronounced effects in A_FB at m(l+l-) approx 160 GeV which, however, will be
difficult to observe experimentally. At high di-lepton invariant masses, the
non-factorizable weak corrections are found to become large.Comment: Revtex3 file, 39 pages, 2 tables, 12 figure
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Two-loop corrections to the fermionic decay rates of the Higgs boson
We calculate the dominant two-loop
electroweak corrections to the fermi\-onic decay widths of a heavy Higgs boson
in the Standard Model. Use of the Goldstone-boson equivalence theorem reduces
the problem to one involving only the physical Higgs boson and the
Goldstone bosons and of the unbroken theory. The two-loop
corrections are opposite in sign to the one-loop electroweak corrections,
exceed the one-loop corrections in magnitude for , and
increase in relative magnitude as for larger values of . We
conclude that the perturbation expansion in powers of breaks down
for . We discuss briefly the QCD and the complete
one-loop electroweak corrections to , and
comment on the validity of the equivalence theorem. Finally we note how a very
heavy Higgs boson could be described in a phenomenological manner.Comment: 24 pages, RevTeX file, 4 figures in a separate compressed uuencoded
Postscript file or available by mail on request. Fig. 1 not included see
Figs. 1, 2 in Phys. Rev. D 48, 1061 (1993
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