On the adsorption and reactivity of element 114, flerovium

Flerovium (Fl, element 114) is the heaviest element chemically studied so far. To date, its interaction with gold was investigated in two gas-solid chromatography experiments, which reported two different types of interaction, however, each based on the level of a few registered atoms only. Whereas noble-gas-like properties were suggested from the first experiment, the second one pointed at a volatile-metal-like character. Here, we present further experimental data on adsorption studies of Fl on silicon oxide and gold surfaces, accounting for the inhomogeneous nature of the surface, as it was used in the experiment and analyzed as part of the reported studies. We confirm that Fl is highly volatile and the least reactive member of group 14. Our experimental observations suggest that Fl exhibits lower reactivity towards Au than the volatile metal Hg, but higher reactivity than the noble gas Rn.

Spectroscopy along Flerovium Decay Chains: Discovery of ^{280}Ds and an Excited State in ^{282}Cn

A nuclear spectroscopy experiment was conducted to study α-decay chains stemming from isotopes of flerovium (element Z=114). An upgraded TASISpec decay station was placed behind the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. The fusion-evaporation reactions ^{48}Ca+^{242}Pu and ^{48}Ca+^{244}Pu provided a total of 32 flerovium-candidate decay chains, of which two and eleven were firmly assigned to ^{286}Fl and ^{288}Fl, respectively. A prompt coincidence between a 9.60(1)-MeV α particle event and a 0.36(1)-MeV conversion electron marked the first observation of an excited state in an even-even isotope of the heaviest man-made elements, namely ^{282}Cn. Spectroscopy of ^{288}Fl decay chains fixed Q_{α}=10.06(1)  MeV. In one case, a Q_{α}=9.46(1)-MeV decay from ^{284}Cn into ^{280}Ds was observed, with ^{280}Ds fissioning after only 518  μs. The impact of these findings, aggregated with existing data on decay chains of ^{286,288}Fl, on the size of an anticipated shell gap at proton number Z=114 is discussed in light of predictions from two beyond-mean-field calculations, which take into account triaxial deformation.

Search for Electron-Capture Delayed Fission in the New Isotope ^{244}Md

The electron-capture decay followed by a prompt fission process was searched for in the hitherto unknown most neutron-deficient Md isotope with mass number 244. Alpha decay with α-particle energies of 8.73-8.86 MeV and with a half-life of 0.30_{-0.09}^{+0.19}  s was assigned to ^{244}Md. No fission event with a similar half-life potentially originating from spontaneous fissioning of the short-lived electron-capture decay daughter ^{244}Fm was observed, which results in an upper limit of 0.14 for the electron-capture branching of ^{244}Md. Two groups of fission events with half-lives of 0.9_{-0.3}^{+0.6}  ms and 5_{-2}^{+3}  ms were observed. The 0.9_{-0.3}^{+0.6}  ms activity was assigned to originate from the decay of ^{245}Md. The origin of eight fission events resulting in a half-life of 5_{-2}^{+3}  ms could not be unambiguously identified within the present data while the possible explanation has to invoke previously unseen physics cases.

CD226 (DNAM-1) is associated with susceptibility to juvenile idiopathic arthritis

OBJECTIVES

Juvenile idiopathic arthritis (JIA) is considered a complex genetic autoimmune disease. We investigated the association of genetic variants previously implicated in JIA, autoimmunity and/or immunoregulation, with susceptibility to JIA.

METHODS

A genetic association study was performed in 639 JIA patients and 1613 healthy controls of northwest European descent. Ninety-three single nucleotide polymorphisms (SNP) were genotyped in a candidate gene approach. Results of the entire JIA patient group (all subtypes) were compared with results obtained, alternatively, with a clinically homogeneous patient group including only oligoarticular and rheumatoid factor (RF) negative polyarticular JIA patients (n=493). Meta-analyses were performed for all SNPs that have been typed in other Caucasian JIA cohorts before.

RESULTS

SNPs in or near PTPN22, VTCN1, the IL2-IL21 region, ANKRD55 and TNFA were confirmed to be associated with JIA (p<0.05), strengthening the evidence for involvement of these genes in JIA. In the majority of these replicated SNPs, effect sizes were larger when analysing a homogeneous patient cohort than when analysing all subtypes. We identified two novel associations with oligoarticular and RF-negative polyarticular JIA: CD226 rs763361 (OR 1.30, 95% CI 1.12 to 1.51, p=0.0006) and CD28 rs1980422 (OR 1.29, 95% CI 1.07 to 1.55, p=0.008). Meta-analyses including reported studies confirmed the association of both SNPs with susceptibility to JIA (OR 1.16, p=0.001 and OR 1.18, p=0.001, for rs763361 and rs1980422, respectively).

CONCLUSIONS

The CD226 gene has been identified as novel association with JIA, and a SNP near CD28 as a suggestive association. Both genes are probable candidate risk factors, since they are involved in costimulation of T cells.

Genetic variation in VTCN1 (B7-H4) is associated with course of disease in juvenile idiopathic arthritis

OBJECTIVE

The course of disease in juvenile idiopathic arthritis (JIA) is unpredictable with episodes of activity and remission. In order to identify predictive factors, 93 SNPs, JIA subtype, age at onset and ANA status were studied in relation to disease course.

METHODS

Genetic and clinical parameters were analysed in a cohort of 272 Caucasian patients with persistent oligoarthritis (n=129), extended oligoarthritis (n=57) and rheumatoid factor negative polyarthritis (n=86). Categories of disease course (remitting (n=65), intermediate (n=96) and unremitting (n=111)) were designed based on the cumulative time spent in active disease in the first 2 years.

RESULTS

Univariate analysis revealed association of the course of disease with JIA subtype (p=5.7*10(-5)) and three SNPs; VTCN1 rs10 923 223 (p=4.4*10(-5)), VTCN1 rs12 046 117 (p=0.017) and CDK6 rs42 041 (p=0.038). In a subsequent multivariate ordinal logistic regression analysis, VTCN1 rs10 923 223 (OR 0.41, 95%-CI 0.26 to 0.63) and JIA subtype (OR 3.8, 95%-CI 2.0 to 7.2; OR 2.5, 95%-CI 1.4 to 4.2, for extended oligoarthritis and RF-negative polyarthritis vs persistent oligoarthritis, respectively) were the strongest independent factors for course of disease.

CONCLUSIONS

This study provides evidence that VTCN1, encoding B7-H4, is associated with course of disease in selected subtypes of JIA. VTCN1 might be useful in predicting the course of disease.

Clinical course and prognostic value of disease activity in the first two years in different subtypes of juvenile idiopathic arthritis

OBJECTIVE

Juvenile idiopathic arthritis (JIA) is a heterogeneous disease involving chronic arthritis. The clinical course is characterized by a fluctuating pattern of active and inactive disease. We have described in detail the clinical course in different JIA subtypes during the first 2 years after diagnosis and studied its relationship to disease activity in the following years.

METHODS

Detailed clinical data on different parameters describing the disease activity in sequential time periods covering the first 2 years after diagnosis were retrieved from the charts of 311 patients with JIA and compared between subtypes. In a cohort of 146 patients, the relation of these different clinical variables to the course of disease in the following 3 years was evaluated.

RESULTS

The percentage of time with active disease in the first 2 years differed significantly between subtypes. In all subtypes, a broad spectrum of activity was observed. The time with active disease in the first 2 years was the most significant factor associated with the duration of active disease in the following years.

CONCLUSION

Different percentages of time with active disease have been observed between JIA subtypes in the first 2 years. The cumulative duration of activity varied widely within each subtype. Regarding the prognosis of the individual patient, the clinical course in the first 2 years appears to be predictive of the clinical course in the following years. Patients that have less time with active disease in the first 2 years are not likely to develop an unremitting clinical course later on.

Association of the autoimmunity locus 4q27 with juvenile idiopathic arthritis

OBJECTIVE

Juvenile idiopathic arthritis (JIA) is characterized by chronic arthritis and an autoimmune etiology. In several autoimmune diseases, including rheumatoid arthritis (RA), an association with the 4q27 locus has been reported. We undertook this study to investigate the possible role of the 4q27 locus in JIA.

METHODS

A case-control association study was conducted, with a total of 655 Caucasian JIA patients and 791 healthy controls divided into 2 independent sample sets. The rs6822844 marker in the 4q27 locus was genotyped.

RESULTS

In the first and larger sample set, a 5% decrease in T allele frequency was observed in patients compared with controls (allelic odds ratio [OR] 0.72 [95% confidence interval 0.55-0.95], P = 0.019), and in the second set, a 3% decrease was observed (allelic OR 0.81 [95% confidence interval 0.61-1.09], P = 0.169). The combined data set generated an OR of 0.76 (95% confidence interval 0.62-0.93, P = 7.08 x 10(-3)). When the different JIA subtypes were analyzed individually, significant decreases were seen in the subtypes with a polyarticular course of disease (extended oligoarthritis [P = 0.019] and rheumatoid factor-negative polyarthritis [P = 0.038]).

CONCLUSION

Our findings suggest that the 4q27 locus, previously reported to be associated with RA, type 1 diabetes mellitus, celiac disease, and psoriatic arthritis, is also associated with susceptibility to JIA.

Time to treatment as an important factor for the response to methotrexate in juvenile idiopathic arthritis

OBJECTIVE

Methotrexate (MTX) is the most commonly used disease-modifying antirheumatic drug in juvenile idiopathic arthritis (JIA). Currently, individual response to MTX cannot be reliably predicted. Identification of clinical and genetic factors that influence the response to MTX could be helpful in realizing the optimal treatment for individual patients.

METHODS

A cohort of 128 JIA patients treated with MTX were studied retrospectively. Eleven clinical parameters and genotypes of 6 single nucleotide polymorphisms in 5 genes related to the mechanism of action of MTX were compared between MTX responders and nonresponders using a multivariate regression analysis.

RESULTS

The time from diagnosis to start of MTX treatment, physician's global assessment at baseline, and the starting dose were significantly associated with the response to MTX at 6 months after initiation. Patients with a shorter time from diagnosis to start of MTX and a higher disease activity according to the physician but with a lower MTX dose showed an increased response. The effect of the starting dose on MTX response seemed to be mainly due to the influence of the systemic JIA subtype. The time from diagnosis to start of MTX treatment and physician's global assessment at baseline were highly correlated. Therefore, the precise effect size of each independent variable could not be determined.

CONCLUSION

In children with JIA, the time from diagnosis to start of MTX appears to be an important factor for MTX response. Our results suggest that an earlier start of MTX treatment will lead to an increased response.

The TRAF1/C5 region is a risk factor for polyarthritis in juvenile idiopathic arthritis

OBJECTIVE

Juvenile idiopathic arthritis (JIA) is a chronic disorder in which both genetic and environmental factors are involved. Recently, we identified the TRAF1/C5 region (located on chromosome 9q33-34) as a risk factor for rheumatoid arthritis (RA) (p(combined) = 1.4 x 10(-8)). In the present study the association of the TRAF1/C5 region with the susceptibility to JIA was investigated.

METHODS

A case-control association study was performed in 338 Caucasian patients with JIA and 511 healthy individuals. We genotyped the single nucleotide polymorphism rs10818488 as a marker for the TRAF1/C5 region.

RESULTS

The A allele was associated with the susceptibility to rheumatoid factor-negative polyarthritis with an 11% increase in allele frequency (OR 1.54, 95% CI 1.09 to 2.18; p = 0.012). This association was stronger when combining subtypes with a polyarticular phenotype (OR 1.46, 95% CI 1.12 to 1.90; p = 0.004). In addition, we observed a trend towards an increase in A allele frequency in patients with extended oligoarthritis versus persistent oligoarthritis (49%, 38% respectively); p = 0.055.

CONCLUSIONS

Apart from being a well replicated risk factor for RA, TRAF1/C5 also appears to be a risk factor for the rheumatoid factor-negative polyarthritis subtype of JIA and, more generally, seems to be associated with subtypes of JIA characterised by a polyarticular course.

[Alcohol intoxication in four adolescents]

Four teenagers, two boys aged 14 and almost 13 years and two girls aged 14.5 and 15 years, were hospitalised because acute alcohol intoxication was suspected. Three of them had only a single instance of excessive alcohol consumption, but the 13-year-old boy was admitted twice in three months due to alcohol intoxication. The blood alcohol concentration in these adolescents varied between 1.4 and 2.3 g/l. During admission the patients were treated symptomatically and there were no complications. Loss of consciousness occurs at lower blood alcohol concentrations in adolescents than in adults. There is also a greater risk of mild hypoglycaemia. In case of recurring excessive alcohol consumption, further psychosocial counselling is necessary.