79 research outputs found
Recent integral cross section validation measurements at the ASP facility
This work presents new integral data measured at the ASP 14 MeV neutron
irradiation facility at Aldermaston in the UK, which has recently become
available for fusion-related work through the CCFE materials programme.
Measurements of reaction products from activation experiments using elemental
foils were carried out using gamma spectrometry in a high efficiency,
high-purity germanium (HPGe) detector and associated digital signal processing
hardware. Following irradiation and rapid extraction to the measurement cell,
gamma emissions were acquired with both energy and time bins. Integral cross
section and half-life data have been derived from these measurements. Selected
integral cross section values are presented from the measurement campaigns.Comment: 4 pages, 5 figure
A predominant involvement of the triple seropositive patients and others with rheumatoid factor in the association of smoking with rheumatoid arthritis
The major environmental risk factor for rheumatoid arthritis (RA) is smoking, which according to a widely accepted model induces protein citrullination in the lungs, triggering the production of anticitrullinated protein antibodies (ACPA) and RA development. Nevertheless, some research findings do not fit this model. Therefore, we obtained six independent cohorts with 2253 RA patients for a detailed analysis of the association between smoking and RA autoantibodies. Our results showed a predominant association of smoking with the concurrent presence of the three antibodies: rheumatoid factor (RF), ACPA and anti-carbamylated protein antibodies (ACarPA) (3 Ab vs. 0 Ab: OR = 1.99, p = 2.5 × 10?8). Meta-analysis with previous data (4491 patients) confirmed the predominant association with the concurrent presence of the three antibodies (3 Ab vs. 0 Ab: OR = 2.00, p = 4.4 ×10?16) and revealed that smoking was exclusively associated with the presence of RF in patients with one or two antibodies (RF+ 1+2 vs. RF? 0+1+2: OR = 1.32, p = 0.0002). In contrast, no specific association with ACPA or ACarPA was found. Therefore, these results showed the need to understand how smoking favors the concordance of RA specific antibodies and RF triggering, perhaps involving smoking-induced epitope spreading and other hypothesized mechanisms
HLA-B*08 identified as the most associated MHC locus for anti-carbamylated protein antibody-positive/anti-CCP-negative rheumatoid arthritis
Objective: Previously, only the HLA-DRB1 alleles have been assessed in rheumatoid arthritis (RA). The aim of the present study was to identify the key major histocompatibility complex (MHC) susceptibility factors showing a significant association with anti-carbamylated protein antibody-positive (anti-CarP+) RA.
Methods: Analyses were restricted to RA patients who were anti-cyclic citrullinated peptide antibody negative (anti-CCP-), because the anti-CCP status dominated the results otherwise. Therefore, we studied samples from 1,821 anti-CCP- RA patients and 6,821 population controls from Spain, Sweden, and the Netherlands. The genotypes for ~8,000 MHC biallelic variants were assessed by dense genotyping and imputation. Their association with the anti-CarP status in RA patients was tested with logistic regression and combined with inverse-variance meta-analysis. Significance of the associations was assessed according to a study-specific threshold of P < 2.0 × 10-5 .
Results: The HLA-B*08 allele and its correlated amino acid variant Asp-9 showed a significant association with anti-CarP+/anti-CCP- RA (P < 3.78 × 10-7 ; I2 = 0). This association was specific when assessed relative to 3 comparator groups: population controls, anti-CarP-/anti-CCP- RA patients, and anti-CCP- RA patients who were positive for other anti-citrullinated protein antibodies. Based on these findings, anti-CarP+/anti-CCP- RA patients could be separated from other antibody-defined subsets of RA patients in whom an association with the HLA-B*08 allele has been previously demonstrated. No other MHC variant remained associated with anti-CarP+/anti-CCP- RA after accounting for the presence of the HLA-B*08 allele. Specifically, the reported association of HLA-DRB1*03 was observed at a level comparable to that reported previously, but it was attributable to linkage disequilibrium.
Conclusion: These results identify HLA-B*08 carrying Asp-9 as the MHC locus showing the strongest association with anti-CarP+/anti-CCP- RA. This knowledge may help clarify the role of the HLA in susceptibility to specific subsets of RA, by shaping the spectrum of RA autoantibodies.
© 2020, American College of Rheumatology
Steroid hormone-related polymorphisms associate with the development of bone erosions in rheumatoid arthritis and help to predict disease progression: Results from the REPAIR consortium
Here, we assessed whether 41 SNPs within steroid hormone genes associated with erosive disease.
The most relevant finding was the rheumatoid factor (RF)-specific effect of the CYP1B1, CYP2C9, ESR2,
FcγR3A, and SHBG SNPs to modulate the risk of bone erosions (P = 0.004, 0.0007, 0.0002, 0.013 and
0.015) that was confirmed through meta-analysis of our data with those from the DREAM registry
(P = 0.000081, 0.0022, 0.00074, 0.0067 and 0.0087, respectively). Mechanistically, we also found a
gender-specific correlation of the CYP2C9rs1799853T/T genotype with serum vitamin D3 levels (P = 0.00085)
and a modest effect on IL1β levels after stimulation of PBMCs or blood with LPS and PHA (P = 0.0057
and P = 0.0058). An overall haplotype analysis also showed an association of 3 ESR1 haplotypes with
a reduced risk of erosive arthritis (P = 0.009, P = 0.002, and P = 0.002). Furthermore, we observed
that the ESR2, ESR1 and FcγR3A SNPs influenced the immune response after stimulation of PBMCs or
macrophages with LPS or Pam3Cys (P = 0.002, 0.0008, 0.0011 and 1.97•10−7). Finally, we found that a model built with steroid hormone-related SNPs significantly improved the prediction of erosive disease
in seropositive patients (PRF+ = 2.46•10−8) whereas no prediction was detected in seronegative patients
(PRF− = 0.36). Although the predictive ability of the model was substantially lower in the replication
population (PRF+ = 0.014), we could confirm that CYP1B1 and CYP2C9 SNPs help to predict erosive
disease in seropositive patients. These results are the first to suggest a RF-specific association of steroid
hormone-related polymorphisms with erosive disease
Respiratory Syncytial Virus Matrix Protein Induces Lung Epithelial Cell Cycle Arrest through a p53 Dependent Pathway
Respiratory syncytial virus (RSV) is the major cause of viral respiratory infections in children. Our previous study showed that the RSV infection induced lung epithelial cell cycle arrest, which enhanced virus replication. To address the mechanism of RSV-induced cell cycle arrest, we examined the contribution of RSV-matrix (RSV-M) protein. In this report, we show that in both the A549 cell line and primary human bronchial epithelial (PHBE) cells, transfection with RSV-M protein caused the cells to proliferate at a slower rate than in control cells. The cell cycle analysis showed that RSV-M protein induced G1 phase arrest in A549 cells, and G1 and G2/M phase arrest in PHBE cells. Interestingly, RSV-M expression induced p53 and p21 accumulation and decreased phosphorylation of retinoblastoma protein (Rb). Further, induction of cell cycle arrest by RSV-M was not observed in a p53-deficient epithelial cell line (H1299). However, cell cycle arrest was restored after transfection of p53 cDNA into H1299 cells. Taken together, these results indicate that RSV-M protein regulates lung epithelial cell cycle through a p53-dependent pathway, which enhances RSV replication
Assessment of global DNA methylation in peripheral blood cell subpopulations of early rheumatoid arthritis before and after methotrexate
Rheumatoid arthritis response to treatment across IgG1 allotype - anti-TNF incompatibility: a case-only study.
INTRODUCTION: We have hypothesized that incompatibility between the G1m genotype of the patient and the G1m1 and G1m17 allotypes carried by infliximab (INX) and adalimumab (ADM) could decrease the efficacy of these anti-tumor necrosis factor (anti-TNF) antibodies in the treatment of rheumatoid arthritis (RA).
METHODS: The G1m genotypes were analyzed in three collections of patients with RA totaling 1037 subjects. The first, used for discovery, comprised 215 Spanish patients. The second and third were successively used for replication. They included 429 British and Greek patients and 393 Spanish and British patients, respectively. Two outcomes were considered: change in the Disease Activity Score in 28 joint (ΔDAS28) and the European League Against Rheumatism (EULAR) response criteria.
RESULTS: An association between less response to INX and incompatibility of the G1m1,17 allotype was found in the discovery collection at 6 months of treatment (P = 0.03). This association was confirmed in the replications (P = 0.02 and 0.08, respectively) leading to a global association (P = 0.001) that involved a mean difference in ΔDAS28 of 0.4 units between compatible and incompatible patients (2.3 ± 1.5 in compatible patients vs. 1.9 ± 1.5 in incompatible patients) and an increase in responders and decrease in non-responders according to the EULAR criteria (P = 0.03). A similar association was suggested for patients treated with ADM in the discovery collection, but it was not supported by replication.
CONCLUSIONS: Our results suggest that G1m1,17 allotypes are associated with response to INX and could aid improved therapeutic targeting in RA
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