431 research outputs found
Differential loss of chromosome 11q in familial and sporadic parasympathetic paragangliomas detected by comparative genomic hybridization
Parasympathetic paragangliomas (PGLs) represent neuroendocrine tumors
arising from chief cells in branchiomeric and intravagal paraganglia,
which share several histological features with their sympathetic
counterpart sympathoadrenal paragangliomas. In recent years, genetic
analyses of the familial form of PGL have attracted considerable interest.
However, the majority of paragangliomas occurs sporadically and it remains
to be determined whether the pathogenesis of sporadic paraganglioma
resembles that of the familial form. Furthermore, data on comparative
genetic aberrations are scarce. To provide fundamental cytogenetic data on
sporadic and hereditary PGLs, we performed comparative genomic
hybridization using directly fluorochrome-conjugated DNA extracted from 12
frozen and 4 paraffin-embedded tumors. The comparative genomic
hybridization data were extended by loss of heterozygosity analysis of
chromosome 11q. DNA copy number changes were found in 10 (63%) of 16
tumors. The most frequent chromosomal imbalance involved loss of
chromosome 11. Six of seven familial tumors and two of nine sporadic
tumors showed loss of 11q (86% versus 22%, P = 0.012). Deletions of 11p
and 5p were found in two of nine sporadic tumors. We conclude that overall
DNA copy number changes are infrequent in PGLs compared to sympathetic
paragangliomas and that loss of chromosome 11 may be an important event in
their tumorigenesis, particularly in familial paragangliomas
Losses of chromosomes 1p and 3q are early genetic events in the development of sporadic pheochromocytomas
Despite several loss of heterozygosity studies, a comprehensive genomic
survey of pheochromocytomas is still lacking. To identify DNA copy number
changes which might be important in tumor development and progression and
which may have diagnostic utility, we evaluated genetic aberrations in 29
sporadic adrenal and extra-adrenal pheochromocytomas (19 clinically benign
tumors and 10 malignant lesions). Comparative genomic hybridization was
performed using directly fluorochrome-conjugated DNA extracted from frozen
(16) and paraffin-embedded (13) tumor tissues. The most frequently
observed changes were losses of chromosomes 1p11-p32 (86%), 3q (52%), 6q
(34%), 3p, 17p (31% each), 11q (28%), and gains of chromosomes 9q (38%)
and 17q (31%). No amplification was identified and no difference between
adrenal and extra-adrenal tumors was detected. Progression to malignant
tumors was strongly associated with deletions of chromosome 6q (60% versus
21% in clinically benign lesions, P = 0.0368) and 17p (50% versus 21%).
Fluorescence in situ hybridization confirmed the comparative genomic
hybridization data of chromosomes 1p, 3q, and 6q, and revealed aneuploidy
in some tumors. Our results suggest that the development of
pheochromocytomas is associated with specific genomic aberrations, such as
losses of 1p, 3q, and 6q and gains of 9q and 17q. In particular, tumor
suppressor genes on chromosomes 1p and 3q may be involved in early
tumorigenesis, and deletions of chromosomes 6q and 17p in progression to
malignancy
Choosing how to choose : Institutional pressures affecting the adoption of personnel selection procedures
The gap between science and practice in personnel selection is an ongoing concern of human resource management. This paper takes OliverÂŽs framework of organizationsÂŽ strategic responses to institutional pressures as a basis for outlining the diverse economic and social demands that facilitate or inhibit the application of scientifically recommended selection procedures. Faced with a complex network of multiple requirements, practitioners make more diverse choices in response to any of these pressures than has previously been acknowledged in the scientific literature. Implications for the science-practitioner gap are discussed
Efficacy and safety of alirocumab in insulin-treated patients with type 1 or type 2 diabetes and high cardiovascular risk:Rationale and design of the ODYSSEY DM-INSULIN trial
Aims: The coadministration of alirocumab, a PCSK9 inhibitor for treatment of hypercholesterolaemia, and insulin in diabetes mellitus (DM) requires further study. Described here is the rationale behind a phase-IIIb study designed to characterize the efficacy and safety of alirocumab in insulin-treated patients with type 1 (T1) or type 2 (T2) DM with hypercholesterolaemia and high cardiovascular (CV) risk. Methods: ODYSSEY DM-INSULIN (NCT02585778) is a randomized, double-blind, placebo-controlled, multicentre study that planned to enrol around 400 T2 and up to 100 T1 insulin-treated DM patients. Participants had low-density lipoprotein cholesterol (LDL-C) levels at screening. â„. 70. mg/dL (1.81. mmol/L) with stable maximum tolerated statin therapy or were statin-intolerant, and taking (or not) other lipid-lowering therapy; they also had established CV disease or at least one additional CV risk factor. Eligible patients were randomized 2:1 to 24. weeks of alirocumab 75. mg every 2. weeks (Q2W) or a placebo. Alirocumab-treated patients with LDL-C. â„. 70. mg/dL at week 8 underwent a blinded dose increase to 150. mg Q2W at week 12. Primary endpoints were the difference between treatment arms in percentage change of calculated LDL-C from baseline to week 24, and alirocumab safety. Results: This is an ongoing clinical trial, with 76 T1 and 441 T2 DM patients enrolled; results are expected in mid-2017. Conclusion: The ODYSSEY DM-INSULIN study will provide information on the efficacy and safety of alirocumab in insulin-treated individuals with T1 or T2 DM who are at high CV risk and have hypercholesterolaemia not adequately controlled by the maximum tolerated statin therapy
Measurement of W Polarisation at LEP
The three different helicity states of W bosons produced in the reaction e+
e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W
decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to
measure the polarisation of W bosons, and its dependence on the W boson
production angle. The fraction of longitudinally polarised W bosons is measured
to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and
the second systematic, in agreement with the Standard Model expectation
Search for Anomalous Couplings in the Higgs Sector at LEP
Anomalous couplings of the Higgs boson are searched for through the processes
e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70
GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity
collected with the L3 detector at LEP at centre-of-mass energies
sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gamma gamma, H
-> Z\gamma and H -> WW^(*) are considered and no evidence is found for
anomalous Higgs production or decay. Limits on the anomalous couplings d, db,
Delta(g1z), Delta(kappa_gamma) and xi^2 are derived as well as limits on the H
-> gamma gamma and H -> Z gamma decay rates
Measurement of W Polarisation at LEP
The three different helicity states of W bosons produced in the reaction e+
e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W
decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to
measure the polarisation of W bosons, and its dependence on the W boson
production angle. The fraction of longitudinally polarised W bosons is measured
to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and
the second systematic, in agreement with the Standard Model expectation
Bose-Einstein Correlations of Neutral and Charged Pions in Hadronic Z Decays
Bose-Einstein correlations of both neutral and like-sign charged pion pairs
are measured in a sample of 2 million hadronic Z decays collected with the L3
detector at LEP. The analysis is performed in the four-momentum difference
range 300 MeV < Q < 2 GeV. The radius of the neutral pion source is found to be
smaller than that of charged pions. This result is in qualitative agreement
with the string fragmentation model
Z Boson Pair-Production at LEP
Events stemming from the pair-production of Z bosons in e^+e^- collisions are
studied using 217.4 pb^-1 of data collected with the L3 detector at
centre-of-mass energies from 200 GeV up to 209 GeV. The special case of events
with b quarks is also investigated.
Combining these events with those collected at lower centre-of-mass energies,
the Standard Model predictions for the production mechanism are verified. In
addition, limits are set on anomalous couplings of neutral gauge bosons and on
effects of extra space dimensions
Neutral-Current Four-Fermion Production in e+e- Interactions at LEP
Neutral-current four-fermion production, e+e- -> ffff is studied in 0.7/fb of
data collected with the L3 detector at LEP at centre-of-mass energies
root(s)=183-209GeV. Four final states are considered: qqvv, qqll, llll and
llvv, where l denotes either an electron or a muon. Their cross sections are
measured and found to agree with the Standard Model predictions. In addition,
the e+e- -> Zgamma* -> ffff process is studied and its total cross section at
the average centre-of-mass energy 196.6GeV is found to be 0.29 +/- 0.05 +/-
0.03 pb, where the first uncertainty is statistical and the second systematic,
in agreement with the Standard Model prediction of 0.22 pb. Finally, the mass
spectra of the qqll final states are analysed to search for the possible
production of a new neutral heavy particle, for which no evidence is found
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