124 research outputs found
Topological Disorder Operators in Three-Dimensional Conformal Field Theory
Many abelian gauge theories in three dimensions flow to interacting conformal
field theories in the infrared. We define a new class of local operators in
these conformal field theories which are not polynomial in the fundamental
fields and create topological disorder. They can be regarded as
higher-dimensional analogues of twist and winding-state operators in free 2d
CFTs. We call them monopole operators for reasons explained in the text. The
importance of monopole operators is that in the Higgs phase, they create
Abrikosov-Nielsen-Olesen vortices. We study properties of these operators in
three-dimensional QED using large N_f expansion. In particular, we show that
monopole operators belong to representations of the conformal group whose
primaries have dimension of order N_f. We also show that monopole operators
transform non-trivially under the flavor symmetry group, with the precise
representation depending on the value of the Chern-Simons coupling.Comment: 24 pages, latex. v2: a reference to prior work has been adde
Basic helix-loop-helix proteins E2A and HEB induce immature T-cell receptor rearrangements in nonlymphoid cells
T-cell receptor (TCR) gene rearrangements are mediated via V(D)J
recombination, which is strictly regulated during lymphoid
differentiation, most probably through the action of specific
transcription factors. Investigated was whether cotransfection of RAG1 and
RAG2 genes in combination with lymphoid transcription factors can induce
TCR gene rearrangements in nonlymphoid human cells. Transfection
experiments showed that basic helix-loop-helix transcription factors E2A
and HEB induce rearrangements in the TCRD locus (Ddelta2-Ddelta3 and
Vdelta2-Ddelta3) and TCRG locus (psi Vgamma7-Jgamma2.3 and
Vgamma8-Jgamma2.3). Analysis of these rearrangements and their circular
excision products revealed some peculiar characteristics. The
Vdelta2-Ddelta3 rearrangements were formed by direct coupling without
intermediate Ddelta2 gene segment usage, and most Ddelta2-Ddelta3
recombinations occurred via direct coupling of the respective upstream and
downstream recombination signal sequences (RSSs) with deletion of the
Ddelta2 and Ddelta3 coding sequences. Subsequently, the E2A/HEB-induced
TCR gene recombination patterns were compared with those in early
thymocytes and acute lymphoblastic leukemias of T- and B-lineage origin,
and it was found that the TCR rearrangements in the transfectants were
early (immature) and not necessarily T-lineage specific. Apparently, some
parts
Progestogenic effects of tibolone on human endometrial cancer cells
Tibolone, a synthetic steroid acting in a tissue-specific manner and used
in hormone replacement therapy, is converted into three active
metabolites: a Delta(4) isomer (exerting progestogenic and androgenic
effects) and two hydroxy metabolites, 3 alpha-hydroxytibolone (3
alpha-OH-tibolone) and 3beta-OH-tibolone (exerting estrogenic effects). In
the present study an endometrial carcinoma cell line (Ishikawa PRAB-36)
was used to investigate the progestogenic properties of tibolone and its
metabolites. This cell line contains progesterone receptors A and B, but
lacks estrogen and androgen receptors. When tibolone was added to the
cells, complete conversion into the progestogenic/androgenic Delta(4)
isomer was observed within 6 d. Furthermore, when cells were cultured with
tibolone or when the Delta(4) isomer or the established progestagen
medroxyprogesterone acetate was added to the medium, marked inhibition of
growth was observed. Interestingly, 3 beta-OH-tibolone also induces some
inhibition of growth. These growth inhibitions were not observed in
progesterone receptor-negative parental Ishikawa cells, and
progestagen-induced growth inhibition of PRAB-36 cells could readily be
reversed using the antiprogestagen Org-31489. Upon measuring the
expression of two progesterone-regulated genes (fibronectin and
IGF-binding protein-3), tibolone, the Delta(4) isomer and
medroxyprogesterone acetate showed similar gene expression regulation.
These results indicate that tibolone, the Delta(4) metabolite, and to some
extent 3 beta-OH-tibolone exert progestogenic effects. Tibolone and most
likely 3 beta-OH-tibolone are converted into the Delta(4) metabolite
Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating'
The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use. In particular, it cannot be used with confidence for 'blind dating'. The compilation of isotopic data on carbonate rocks reveals a high level of inconsistency between various carbon isotope age curves constructed for Neoproteozoic seawater, caused by a relatively high frequency of both global and local delta C-13(carb) fluctuations combined with few reliable age determinations. Further complication is caused by the unresolved problem as to whether two or four glaciations, and associated negative delta C-13(carb) excursions, can be reliably documented. Carbon isotope stratigraphy cannot be used alone for geological correlation and 'blind dating'. Strontium isotope stratigraphy is a more reliable and precise tool for stratigraphic correlations and indirect age determinations. Combining strontium and carbon isotope stratigraphy, several discrete ages within the 590-544 Myr interval, and two age-groups at 660-610 and 740-690 Myr can be resolved
Examining the construct and known-group validity of a composite endpoint for the Older Persons and Informal Caregivers Survey Minimum Data Set (TOPICS-MDS); A largescale data sharing initiative
Background Preference-weighted multi-faceted endpoints have the potential to facilitate comparative effectiveness research that incorporates patient preferences. The Older Persons and Informal Caregivers Survey Composite endpoint (TOPICS-CEP) is potentially a valuable outcome measure for evaluating interventions in geriatric care as it combines multiple outcomes relevant to older persons in a single metric. The objective of this study was to validate TOPICS-CEP across different study settings (general population, primary care and hospital). Methods Data were extracted from TOPICS Minimum Dataset (MDS), a pooled public-access national database with information on older persons throughout the Netherlands. Data of
Subcutaneous abatacept in patients with polyarticular-course juvenile idiopathic arthritis : results from a phase III open-label study
OBJECTIVE : To investigate the pharmacokinetics, effectiveness, and safety of subcutaneous (SC) abatacept treatment over 24 months in patients with polyarticularâcourse juvenile idiopathic arthritis (JIA).
METHODS: In this phase III, openâlabel, international, multicenter, singleâarm study, patients with polyarticular JIA (cohort 1, ages 6â17 years and cohort 2, ages 2â5 years) in whom treatment with â„1 diseaseâmodifying antirheumatic drug was unsuccessful received weightâtiered SC abatacept weekly: 10 to <25 kg (50 mg), 25 to <50 kg (87.5 mg), â„50 kg (125 mg). Patients who had met the JIAâAmerican College of Rheumatology 30% improvement criteria (achieved a JIAâACR 30 response) at month 4 were given the option to continue SC abatacept to month 24. The primary end point was the abatacept steadyâstate serum trough concentration (Cminss) in cohort 1 at month 4. Other outcome measures included JIAâACR 30, 50, 70, 90, 100, and inactive disease status, the median Juvenile Arthritis Disease Activity Score in 71 joints using the Câreactive protein level (JADASâ71âCRP) over time, safety, and immunogenicity.
RESULTS : The median abatacept Cminss at month 4 (primary end point) and at month 24 was above the target therapeutic exposure (10 ÎŒg/ml) in both cohorts. The percentage of patients who had achieved JIAâACR 30, 50, 70, 90, or 100 responses or had inactive disease responses at month 4 (intentâtoâtreat population) was 83.2%, 72.8%, 52.6%, 28.3%, 14.5%, and 30.1%, respectively, in cohort 1 (n = 173) and 89.1%, 84.8%, 73.9%, 58.7%, 41.3%, and 50.0%, respectively, in cohort 2 (n = 46); the responses were maintained to month 24. The median (interquartile range) JADASâ71âCRP improved from baseline to month 4: cohort 1, from 21.0 (13.5, 30.3) to 4.6 (2.1, 9.4); cohort 2, from 18.1 (14.0, 23.1) to 2.1 (0.3, 4.4). Improvements were sustained to month 24, at which time 27 of 173 patients (cohort 1) and 11 of 22 patients (cohort 2) had achieved JADASâ71âCRP remission. No unexpected adverse events were reported; 4 of 172 patients (2.3%) in cohort 1 and 4 of 46 (8.7%) in cohort 2 developed antiâabatacept antibodies, with no clinical effects.
CONCLUSION : Weightâstratified SC abatacept yielded target therapeutic exposures across age and weight groups, was well tolerated, and improved polyarticular JIA symptoms over 24 months.Results From a Phase III OpenâLabel StudyWriting assistance was funded by BristolâMyers Squibb.https://onlinelibrary.wiley.com/journal/23265205am2018Internal Medicin
PHIP - a novel candidate breast cancer susceptibility locus on 6q14.1
Most non-BRCA1/2 breast cancer families have no identified genetic cause. We used linkage and haplotype analyses in familial and sporadic breast cancer cases to identify a susceptibility locus on chromosome 6q. Two independent genome-wide linkage analysis studies suggested a 3 Mb locus on chromosome 6q and two unrelated Swedish families with a LOD > 2 together seemed to share a haplotype in 6q14.1. We hypothesized that this region harbored a rare high-risk founder allele contributing to breast cancer in these two families. Sequencing of DNA and RNA from the two families did not detect any pathogenic mutations. Finally, 29 SNPs in the region were analyzed in 44,214 cases and 43,532 controls from BCAC, and the original haplotypes in the two families were suggested as low-risk alleles for European and Swedish women specifically. There was also some support for one additional independent moderate-risk allele in Swedish familial samples. The results were consistent with our previous findings in familial breast cancer and supported a breast cancer susceptibility locus at 6q14.1 around the PHIP gene.Peer reviewe
National laboratory-based surveillance system for antimicrobial resistance: a successful tool to support the control of antimicrobial resistance in the Netherlands
An important cornerstone in the control of antimicrobial resistance (AMR) is a well-designed quantitative system for the surveillance of spread and temporal trends in AMR. Since 2008, the Dutch national AMR surveillance system, based on routine data from medical microbiological laboratories (MMLs), has developed into a successful tool to support the control of AMR in the Netherlands. It provides background information for policy making in public health and healthcare services, supports development of empirical antibiotic therapy guidelines and facilitates in-depth research. In addition, participation of the MMLs in the national AMR surveillance network has contributed to sharing of knowledge and quality improvement. A future improvement will be the implementation of a new semantic standard together with standardised data transfer, which will reduce errors in data handling and enable a more real-time surveillance. Furthermore, the
Molecular characteristics of carbapenemase-producing Enterobacterales in the Netherlands; results of the 2014â2018 national laboratory surveillance
Objectives: Carbapenem resistance mediated by mobile genetic elements has emerged worldwide and has become a major public health threat. To gain insight into the molecular epidemiology of carbapenem resistance in The Netherlands, Dutch medical microbiology laboratories are requested to submit suspected carbapenemase-producing Enterobacterales (CPE) to the National Institute for Public Health and the Environment as part of a national surveillance system. Methods: Meropenem MICs and species identification were confirmed by E-test and MALDI-TOF and carbapenemase production was assessed by the Carbapenem Inactivation Method. Of all submitted CPE, one species/carbapenemase gene combination per person per year was subjected to next-generation sequencing (NGS). Results: In total, 1838 unique isolates were received between 2014 and 2018, of which 892 were unique CPE isolates with NGS data available. The predominant CPE species were Klebsiella pneumoniae (n = 388, 43%), Escherichia coli (n = 264, 30%) and Enterobacter cloacae complex (n = 116, 13%). Various carbapenemase alleles of the same carbapenemase gene resulted in different susceptibilities to meropenem and this effect varied between species. Analyses of NGS data showed variation of prevalence of carbapenemase alleles over time with blaOXA-48 being predominant (38%, 336/892), followed by blaNDM-1 (16%, 145/892). For the first time in the Netherlands, blaOXA-181, blaOXA-232 and blaVIM-4 were detected. The genetic background of K. pneumoniae and E. coli isolates was highly diverse. Conclusions: The CPE population in the Netherlands is diverse, suggesting multiple introductions. The predominant carbapenemase alleles are blaOXA-48 and blaNDM-1. There was a clear association between species, carbapenemase allele and susceptibility to meropenem
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