| 1. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Barreto, VM, et al.
(författare)
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AID from bony fish catalyzes class switch recombination
- 2005
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Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 202:6, s. 733-738
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Tidskriftsartikel (refereegranskat)abstract
- Class switch recombination was the last of the lymphocyte-specific DNA modification reactions to appear in the evolution of the adaptive immune system. It is absent in cartilaginous and bony fish, and it is common to all tetrapods. Class switching is initiated by activation-induced cytidine deaminase (AID), an enzyme expressed in cartilaginous and bony fish that is also required for somatic hypermutation. Fish AID differs from orthologs found in tetrapods in several respects, including its catalytic domain and carboxy-terminal region, both of which are essential for the switching reaction. To determine whether evolution of class switch recombination required alterations in AID, we assayed AID from Japanese puffer and zebra fish for class-switching activity in mouse B cells. We find that fish AID catalyzes class switch recombination in mammalian B cells. Thus, AID had the potential to catalyze this reaction before the teleost and tetrapod lineages diverged, suggesting that the later appearance of a class-switching reaction was dependent on the evolution of switch regions and multiple constant regions in the IgH locus.
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| 3. |
- Bergin, Philip, 1975, et al.
(författare)
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Secretion of matrix metalloproteinase-9 by macrophages, in vitro, in response to Helicobacter pylori.
- 2005
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Ingår i: FEMS immunology and medical microbiology. - : Oxford University Press (OUP). - 0928-8244 .- 1574-695X. ; 45:2, s. 159-69
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Forskningsöversikt (refereegranskat)abstract
- We have previously shown that matrix metalloproteinase-9 (MMP-9) activity is greatly enhanced within the active chronic inflammation of Helicobacter pylori infected individuals, of which a major fraction derives from macrophages in the tissue. Here, we have investigated the ability of macrophages to secrete MMPs in response to H. pylori. Human macrophages secrete MMP-9 in response to live and inactivated H. pylori, as well as to specific bacterial products. Protein kinase C, phosphatiolylinositol 3-kinase and calcium uptake channels all play a role in MMP-9 secretion, whereas neither tumour necrosis factor alpha, interleukin-8, nor interleukin-1beta autocrine stimulation appear to contribute. We conclude that human macrophages have the ability to react directly against several H. pylori derived factors, utilising several signalling pathways.
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| 4. |
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| 5. |
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| 6. |
- Du, LK, et al.
(författare)
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Involvement of Artemis in nonhomologous end-joining during immunoglobulin class switch recombination
- 2008
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Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 205:13, s. 3031-3040
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Tidskriftsartikel (refereegranskat)abstract
- DNA double-strand breaks (DSBs) introduced in the switch (S) regions are intermediates during immunoglobulin class switch recombination (CSR). These breaks are subsequently recognized, processed, and joined, leading to recombination of the two S regions. Nonhomologous end-joining (NHEJ) is believed to be the principle mechanism involved in DSB repair during CSR. One important component in NHEJ, Artemis, has however been considered to be dispensable for efficient CSR. In this study, we have characterized the S recombinational junctions from Artemis-deficient human B cells. Sμ–Sα junctions could be amplified from all patients tested and were characterized by a complete lack of “direct” end-joining and a remarkable shift in the use of an alternative, microhomology-based end-joining pathway. Sμ–Sγ junctions could only be amplified from one patient who carries “hypomorphic” mutations. Although these Sμ–Sγ junctions appear to be normal, a significant increase of an unusual type of sequential switching from immunoglobulin (Ig)M, through one IgG subclass, to a different IgG subclass was observed, and the Sγ–Sγ junctions showed long microhomologies. Thus, when the function of Artemis is impaired, varying modes of CSR junction resolution may be used for different S regions. Our findings strongly link Artemis to the predominant NHEJ pathway during CSR.
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| 7. |
- Enarsson, Karin, 1975, et al.
(författare)
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Differential mechanisms for T lymphocyte recruitment in normal and neoplastic human gastric mucosa
- 2006
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Ingår i: Clin Immunol. - : Elsevier BV. ; 118:1, s. 24-34
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Forskningsöversikt (refereegranskat)abstract
- Worldwide, gastric adenocarcinoma (GC) is the second most common cause of death from malignant disease. The reason why immune responses are unable to clear the tumour is not fully understood, although aberrant lymphocyte recruitment to the tumour site might be one factor. Therefore, we investigated the homing phenotype of mucosal T lymphocytes in GC, compared to tumour-free mucosa. We could detect significantly decreased frequencies of mucosal homing alpha4beta7+ T cells in the tumour tissues and increased frequencies of L-selectin+ T cells. This was probably due to the correlated decrease in MAdCAM-1 positive and increase in PNAd positive blood vessels in the tumour mucosa. There were also fewer CXCR3+ T lymphocytes in the tumour tissue. These findings provide evidence that endothelial cells within tumours arising at mucosal sites do not support extravasation of typical mucosa-infiltrating T cells. This may be of major relevance for future immunotherapeutic strategies for treatment of GC.
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| 9. |
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| 10. |
- Janzi, M., et al.
(författare)
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Serum microarrays for large scale screening of protein levels
- 2005
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 4:12, s. 1942-1947
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Tidskriftsartikel (refereegranskat)abstract
- There is a great need for comprehensive proteomic analysis of large patient cohorts of plasma and serum samples to identify biomarkers of human diseases. Here we describe a new antibody-based proteomic approach involving a reverse array format where serum samples are spotted on a microarray. This enables all samples to be screened for their content of a certain serum protein in a single experiment using target-recognizing antibodies and fluorescently labeled secondary antibodies. The procedure is illustrated with the analysis of the IgA levels in 2009 spotted serum samples, and the data are compared with clinical routine measurements. The results suggest that it is possible to simultaneously screen thousands of complex clinical serum samples for their content of the relative amount of specific serum proteins of clinical relevance.
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