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1.
Phys Rev Lett ; 132(18): 182502, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38759198

RESUMO

The observation of neutrinoless double-beta (0νßß) decay would offer proof of lepton number violation, demonstrating that neutrinos are Majorana particles, while also helping us understand why there is more matter than antimatter in the Universe. If the decay is driven by the exchange of the three known light neutrinos, a discovery would, in addition, link the observed decay rate to the neutrino mass scale through a theoretical quantity known as the nuclear matrix element (NME). Accurate values of the NMEs for all nuclei considered for use in 0νßß experiments are therefore crucial for designing and interpreting those experiments. Here, we report the first comprehensive ab initio uncertainty quantification of the 0νßß-decay NME, in the key nucleus ^{76}Ge. Our method employs nuclear strong and weak interactions derived within chiral effective field theory and recently developed many-body emulators. Our result, with a conservative treatment of uncertainty, is an NME of 2.60_{-1.36}^{+1.28}, which, together with the best-existing half-life sensitivity and phase-space factor, sets an upper limit for effective neutrino mass of 187_{-62}^{+205} meV. The result is important for designing next-generation germanium detectors aiming to cover the entire inverted hierarchy region of neutrino masses.

2.
Phys Rev Lett ; 126(7): 072501, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33666458

RESUMO

We studied the proton-rich T_{z}=-1 nucleus ^{70}Kr through inelastic scattering at intermediate energies in order to extract the reduced transition probability, B(E2;0^{+}→2^{+}). Comparison with the other members of the A=70 isospin triplet, ^{70}Br and ^{70}Se, studied in the same experiment, shows a 3σ deviation from the expected linearity of the electromagnetic matrix elements as a function of T_{z}. At present, no established nuclear structure theory can describe this observed deviation quantitatively. This is the first violation of isospin symmetry at this level observed in the transition matrix elements. A heuristic approach may explain the anomaly by a shape change between the mirror nuclei ^{70}Kr and ^{70}Se contrary to the model predictions.

3.
Phys Rev Lett ; 124(23): 232501, 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32603157

RESUMO

Working with Hamiltonians from chiral effective field theory, we develop a novel framework for describing arbitrary deformed medium-mass nuclei by combining the in-medium similarity renormalization group with the generator coordinate method. The approach leverages the ability of the first method to capture dynamic correlations and the second to include collective correlations without violating symmetries. We use our scheme to compute the matrix element that governs the neutrinoless double beta decay of ^{48}Ca to ^{48}Ti, and find it to have the value 0.61, near or below the predictions of most phenomenological methods. The result opens the door to ab initio calculations of the matrix elements for the decay of heavier nuclei such as ^{76}Ge, ^{130}Te, and ^{136}Xe.

4.
Phys Rev Lett ; 124(22): 222501, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32567911

RESUMO

Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of ß∼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Z∼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se_{60} ground-state band.

5.
Phys Rev Lett ; 123(14): 142502, 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31702191

RESUMO

From detailed spectroscopy of ^{110}Cd and ^{112}Cd following the ß^{+}/electron-capture decay of ^{110,112}In and the ß^{-} decay of ^{112}Ag, very weak decay branches from nonyrast states are observed. The transition rates determined from the measured branching ratios and level lifetimes obtained with the Doppler-shift attenuation method following inelastic neutron scattering reveal collective enhancements that are suggestive of a series of rotational bands. In ^{110}Cd, a γ band built on the shape-coexisting intruder configuration is suggested. For ^{112}Cd, the 2^{+} and 3^{+} intruder γ-band members are suggested, the 0_{3}^{+} band is extended to spin 4^{+}, and the 0_{4}^{+} band is identified. The results are interpreted using beyond-mean-field calculations employing the symmetry conserving configuration mixing method with the Gogny D1S energy density functional and with the suggestion that the Cd isotopes exhibit multiple shape coexistence.

6.
Phys Rev Lett ; 118(15): 152504, 2017 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-28452498

RESUMO

Despite the more than 1 order of magnitude difference between the measured dipole moments in ^{144}Ba and ^{146}Ba, the octupole correlations in ^{146}Ba are found to be as strong as those in ^{144}Ba with a similarly large value of B(E3;3^{-}→0^{+}) determined as 48(+21-29) W.u. The new results not only establish unambiguously the presence of a region of octupole deformation centered on these neutron-rich Ba isotopes, but also manifest the dependence of the electric dipole moments on the occupancy of different neutron orbitals in nuclei with enhanced octupole strength, as revealed by fully microscopic calculations.

7.
Phys Rev Lett ; 118(3): 032501, 2017 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-28157341

RESUMO

The first measurement of the low-lying states of the neutron-rich ^{110}Zr and ^{112}Mo was performed via in-beam γ-ray spectroscopy after one proton removal on hydrogen at ∼200 MeV/nucleon. The 2_{1}^{+} excitation energies were found at 185(11) keV in ^{110}Zr, and 235(7) keV in ^{112}Mo, while the R_{42}=E(4_{1}^{+})/E(2_{1}^{+}) ratios are 3.1(2), close to the rigid rotor value, and 2.7(1), respectively. These results are compared to modern energy density functional based configuration mixing models using Gogny and Skyrme effective interactions. We conclude that first levels of ^{110}Zr exhibit a rotational behavior, in agreement with previous observations of lighter zirconium isotopes as well as with the most advanced Monte Carlo shell model predictions. The data, therefore, do not support a harmonic oscillator shell stabilization scenario at Z=40 and N=70. The present data also invalidate predictions for a tetrahedral ground state symmetry in ^{110}Zr.

8.
Phys Rev Lett ; 118(24): 242501, 2017 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-28665635

RESUMO

We report on the first γ-ray spectroscopy of low-lying states in neutron-rich ^{98,100}Kr isotopes obtained from ^{99,101}Rb(p,2p) reactions at ∼220 MeV/nucleon. A reduction of the 2_{1}^{+} state energies beyond N=60 demonstrates a significant increase of deformation, shifted in neutron number compared to the sharper transition observed in strontium and zirconium isotopes. State-of-the-art beyond-mean-field calculations using the Gogny D1S interaction predict level energies in good agreement with experimental results. The identification of a low-lying (0_{2}^{+}, 2_{2}^{+}) state in ^{98}Kr provides the first experimental evidence of a competing configuration at low energy in neutron-rich krypton isotopes consistent with the oblate-prolate shape coexistence picture suggested by theory.

9.
Phys Rev Lett ; 117(6): 062501, 2016 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-27541463

RESUMO

Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in ^{42}Ca were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 0_{2}^{+} has been obtained and the role of triaxiality in the A∼40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time.

10.
Phys Rev Lett ; 111(17): 172501, 2013 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-24206482

RESUMO

The nucleus (154)Gd is located in a region of the nuclear chart where rapid changes of nuclear deformation occur as a function of particle number. It was investigated using a combination of γ-ray scattering experiments and a γγ-coincidence study following electron capture decay of (154)Tb(m). A novel decay channel from the scissors mode to the first excited 0(+) state was observed. Its transition strength was determined to B(M1;1(sc)(+)→0(2)(+))=0.031(4)µ(N)(2). The properties of the scissors mode of (154)Gd imply a much larger matrix element than previously thought for the neutrinoless double-ß decay to the 0(2)(+) state in such a shape-transitional region. Theory indicates an even larger effect for (150)Nd.

11.
Ann Rheum Dis ; 71(6): 943-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22228484

RESUMO

OBJECTIVES: Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are relatively common inflammatory disorders. Establishing the diagnosis however may be difficult, since so far no specific biomarkers of the disorders are available. METHODS: As a screening procedure, the authors used protein arrays for the detection of new autoantigens in GCA and PMR. The results of the protein array were confirmed by different ELISAs detecting IgG antibodies against the human ferritin heavy chain, N-terminal 27 amino acids of the human ferritin heavy chain or the homologous peptide of Staphylococcus epidermidis. Sera of patients with only GCA (n=64), only PMR (n=47) and both PMR and GCA (n=31) were used. RESULTS: In the ELISA using the human ferritin peptide, the sensitivity of IgG antibodies against ferritin was 92% in 36 GCA and/or PMR patients before initiation of treatment, 22/32 (69%) in patients with disease flares and 64/117 (55%) in the total cohort including treated and inactive patients. In controls, the false positive rate was 11/38 (29%) in systemic lupus erythematosus, 1/36 (3%) in rheumatoid arthritis, 0/31 (0%) in late onset rheumatoid arthritis, 3/46 (6.5%) in B-non-Hodgkin's lymphoma and 1/100 (1%) in blood donors. In the ELISA using the ferritin peptide of S epidermidis, 89% of 27 patients with untreated GCA and PMR were positive. CONCLUSION: Antibodies against the ferritin peptide were present in up to 92% of untreated, active GCA and PMR patients. They can be useful as a diagnostic marker of PMR and GCA.


Assuntos
Apoferritinas/imunologia , Autoanticorpos/sangue , Arterite de Células Gigantes/imunologia , Polimialgia Reumática/imunologia , Adulto , Idoso , Autoantígenos/imunologia , Biomarcadores/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Reações Falso-Positivas , Feminino , Arterite de Células Gigantes/epidemiologia , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Polimialgia Reumática/epidemiologia , Análise Serial de Proteínas , Estudos Soroepidemiológicos , Staphylococcus epidermidis/imunologia
12.
Tissue Antigens ; 77(4): 291-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21388351

RESUMO

To determine the contribution of the vascular endothelial growth factor A (VEGFA) rs2010963 (-634 G>C) and rs1570360 (-1154 G>A) polymorphisms to the risk of cardiovascular (CV) disease in a series of patients with rheumatoid arthritis (RA). Six hundred sixty-one patients fulfilling the 1987 American College of Rheumatology classification criteria for RA, seen at the rheumatology outpatient clinics of the Hospital Xeral-Calde, Lugo, and the Hospital San Carlos, Madrid, Spain, were studied. Patients were genotyped for the VEGFA rs2010963 (-634 G>C) and rs1570360 (-1154 G>A) polymorphisms using predesigned TaqMan single nucleotide polymorphism (SNP) genotyping assay (Applied Biosystems, Foster City, CA). Also, human leukocyte antigen (HLA) DRB1 genotyping was performed using molecular-based methods. Clinical histories of the patients were reviewed for the presence of CV events that were considered to be present if the patient had ischemic heart disease, heart failure, cerebrovascular accident, or peripheral arteriopathy. Also, a subgroup of patients without the history of CV events was assessed for the presence of subclinical atherosclerosis manifested by the presence of endothelial dysfunction by brachial artery reactivity (n = 126) and increased carotid artery intima-media thickness (n = 105) using high resolution Doppler ultrasonography. No significant association between the VEGFA rs2010963 and the rs1570360 polymorphisms (neither isolated nor joined as allelic combinations) with clinically evident CV disease was found in this series of patients with RA. It was also the case when we examined the contribution of these polymorphisms to the development of subclinical atherosclerosis. VEGFA polymorphisms do not seem to exert a significant influence on the risk of CV disease in patients with RA.


Assuntos
Artrite Reumatoide/genética , Doenças Cardiovasculares/genética , Polimorfismo de Nucleotídeo Único , Fator A de Crescimento do Endotélio Vascular/genética , Idoso , Alelos , Artrite Reumatoide/sangue , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/etiologia , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/diagnóstico , Antígenos HLA-DR/sangue , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Espanha , Fator A de Crescimento do Endotélio Vascular/metabolismo
13.
Tissue Antigens ; 77(1): 74-8, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21073447

RESUMO

To assess the potential association between ADIPOQ rs266729 and rs1501299 gene polymorphisms, either isolated or in combination, and cardiovascular disease in patients with rheumatoid arthritis (RA), 674 patients seen at the rheumatology outpatient clinics of Hospital Xeral-Calde, Lugo, and Hospital San Carlos, Madrid, Spain, were analyzed. Genotyping was performed using predesigned TaqMan assays (Applied Biosystems, Foster City, CA). Carotid intima-media thickness, flow-mediated endothelium-dependent and endothelium-independent post-nitroglycerin vasodilatation, which are used as surrogate markers of subclinical atherosclerosis, were measured in a subsample. No significant differences in the genotype, allele or allele combination frequencies of both polymorphisms were found between RA patients with or without cardiovascular events or subclinical atherosclerosis. Therefore, ADIPOQ rs266729 and rs1501299 polymorphisms do not seem to be associated with cardiovascular disease in RA.


Assuntos
Adipocinas/genética , Artrite Reumatoide/complicações , Artrite Reumatoide/genética , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/genética , Predisposição Genética para Doença , Polimorfismo Genético , Humanos
14.
Clin Exp Rheumatol ; 29(2): 293-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21385539

RESUMO

OBJECTIVES: To assess the potential association between LEP rs2167270 (19 G>A) gene polymorphism and disease susceptibility and cardiovascular disease (CV) in patients with rheumatoid arthritis (RA). METHODS: 773 patients fulfilling the 1987 American College of Rheumatology classification criteria for RA, seen at the rheumatology outpatient clinics of Hospital Xeral-Calde, Lugo, and Hospital San Carlos, Madrid, Spain, and 957 matched controls, were studied. Patients were genotyped for the LEP rs2167270 (19G>A) polymorphism, located within the 5´UTR, using predesigned TaqMan single nucleotide polymorphism genotyping assay. Also, HLA-DRB1 genotyping was performed using molecular based methods. Subclinical atherosclerosis was assessed in a subgroup of patients with no history of CV events by brachial artery reactivity to determine flow-mediated endothelium-dependent and endothelium-independent vasodilatation (n=133) and by B-mode ultrasonography of the carotid artery intima-media thickness (n=113). RESULTS: No statistically significant differences in the genotype or allele frequencies of the LEP rs2167270 gene polymorphism between patients with RA and controls were seen. Likewise, LEP rs2167270 polymorphism did not influence the development of CV events. Also, no significant differences in LEP rs2167270 genotype or allele distribution were seen when results of surrogate markers of subclinical atherosclerosis were assessed. CONCLUSIONS: LEP rs2167270 polymorphism does not seem to be a genetic risk factor for disease susceptibility or clinically evident CV disease and subclinical atherosclerosis in patients with RA.


Assuntos
Artrite Reumatoide/epidemiologia , Artrite Reumatoide/genética , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/genética , Leptina/genética , Idoso , Feminino , Frequência do Gene , Predisposição Genética para Doença/epidemiologia , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Fatores de Risco
15.
Clin Exp Rheumatol ; 29(4): 681-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21906432

RESUMO

OBJECTIVES: Visfatin is an adipokine encoded by the NAMPT (PBEF1) gene. In this study we assessed the potential association of two NAMPT gene polymorphisms with disease susceptibility and cardiovascular (CV) risk in patients with rheumatoid arthritis (RA). METHODS: A total of 1,395 patients fulfilling the 1987 ACR classification criteria for RA and 1,230 matched controls, were genotyped for the NAMPT rs9770242 and rs59744560 gene polymorphisms, located within the proximal promoter, using predesigned TaqMan single nucleotide polymorphism genotyping assay. Also, HLA-DRB1 genotyping was performed using molecular based methods. In a second step, 1,196 patients in whom full information was available were assessed to determine the influence of NAMPT rs9770242 and rs59744560 polymorphisms in the development of CV events. Also, the potential influence of these polymorphisms in the development of subclinical atherosclerosis was assessed in a subgroup of patients with no history of CV events by brachial artery reactivity to determine flow-mediated endothelium-dependent and endothelium-independent vasodilatation (n=125) and by B-mode ultrasonography to determine the carotid artery intima-media thickness (n=105). RESULTS: No statistically significant differences in the allele or genotype frequencies for the NAMPT gene polymorphisms between RA patients and controls were found. A modest non significant lower frequency of the minor allele G of rs9770242 polymorphism was observed among patients with CV disease (20.62%) compared to those without CV disease (22.83%) (p=0.39). Also, a slight nonsignificant lower frequency of the minor allele T of rs59744560 polymorphism in patients with CV events (9.81%) compared with those RA patients who did not experience CV disease (13.07%) (p=0.11) was observed. Likewise, no significant association between the NAMPT polymorphisms with surrogate markers of subclinical atherosclerosis was found in patients with RA. CONCLUSIONS: NAMPT rs9770242 and rs59744560 polymorphisms are not markers of disease susceptibility and CV disease in RA.


Assuntos
Artrite Reumatoide/genética , Doenças Cardiovasculares/genética , Citocinas/genética , Nicotinamida Fosforribosiltransferase/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Análise de Variância , Artrite Reumatoide/complicações , Artrite Reumatoide/enzimologia , Artéria Braquial/fisiopatologia , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/enzimologia , Doenças Cardiovasculares/fisiopatologia , Artérias Carótidas/diagnóstico por imagem , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Feminino , Frequência do Gene , Predisposição Genética para Doença , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fenótipo , Regiões Promotoras Genéticas , Medição de Risco , Fatores de Risco , Espanha , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Ultrassonografia , Vasodilatação
16.
Clin Exp Rheumatol ; 28(5): 695-701, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20822712

RESUMO

OBJECTIVES: To determine whether the PTPN22, STAT4 and TRAF1/C5 gene polymorphisms may be implicated in the development of cardiovascular (CV) events and subclinical atherosclerosis manifested by the presence of endothelial dysfunction or increased carotid intima-media thickness (IMT) in a series of Spanish patients with rheumatoid arthritis (RA). METHODS: Six hundred and twelve patients fulfilling the 1987 American College of Rheumatology classification criteria for RA, seen at the rheumatology outpatient clinics of Hospital Xeral-Calde, Lugo, and Hospital San Carlos, Madrid, were studied. Patients were genotyped using predesigned TaqMan single nucleotide polymorphism genotyping assays. Moreover, between March and December 2007, a subgroup of unselected RA patients with no history of CV events was studied for the presence of subclinical atherosclerosis by the assessment of the endothelial function (n=126) and the carotid artery IMT (n=110) by ultrasonography studies. RESULTS: No significant differences in the allele or genotype frequencies for the PTPN22, STAT4 and TRAF1/C5 gene polymorphisms between RA patients with or without CV events were found. It was also the case when we analysed the potential influence of the genotypes in the presence of endothelial dysfunction or increased carotid artery IMT of patients with RA. CONCLUSIONS: Our results do not show that the PTPN22, STAT4 and TRAF1/C5 gene polymorphisms may confer a direct risk of CV disease in patients with RA.


Assuntos
Artrite Reumatoide/genética , Doenças Cardiovasculares/genética , Complemento C5/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Proteína Tirosina Fosfatase não Receptora Tipo 22/genética , Fator de Transcrição STAT4/genética , Fator 1 Associado a Receptor de TNF/genética , Artrite Reumatoide/epidemiologia , Aterosclerose/diagnóstico , Aterosclerose/epidemiologia , Aterosclerose/genética , Doenças Cardiovasculares/epidemiologia , Comorbidade , Complemento C5/metabolismo , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Proteína Tirosina Fosfatase não Receptora Tipo 22/metabolismo , Fatores de Risco , Fator de Transcrição STAT4/metabolismo , Fator 1 Associado a Receptor de TNF/metabolismo
17.
Clin Exp Rheumatol ; 28(1): 56-62, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20346239

RESUMO

BACKGROUND AND OBJECTIVE: Visfatin is an insulin-mimetic adipokine. In non-rheumatoid arthritis (RA) patients circulating levels of visfatin are correlated with the amount of visceral fat. Recent studies have disclosed an implication of visfatin in inflammation. Chronic systemic inflammation is of major importance in the development of atherosclerosis in RA. In the present study we investigated whether inflammation, obesity or metabolic syndrome are potential determinants of circulating visfatin concentrations in a group of RA patients on periodical treatment with the TNF-alpha blocker infliximab due to severe disease. We also assessed whether the infusion of infliximab may alter circulating visfatin concentrations in patients with severe RA. METHODS: We investigated 33 non-diabetic patients with RA on periodical treatment with infliximab. Serum visfatin levels were determined immediately prior to and after infliximab infusion. RESULTS: There was no correlation between body mass index of RA patients and baseline serum level of visfatin. Also, no significant correlations between baseline visfatin levels and the age at the time of the study or at the onset of the disease, disease duration, ESR and CRP levels, DAS28, lipids, insulin sensitivity, resistin or the cumulative prednisone dose at the time of the study were found. Visfatin levels did not change upon infliximab infusion. CONCLUSIONS: In RA patients on TNF-alpha blocker treatment, circulating visfatin levels are unrelated to disease activity, adiposity or metabolic syndrome. The beneficial effect of anti-TNF-alpha therapy on cardiovascular mortality in RA does not seem to be mediated by changes in serum levels of visfatin.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Artrite Reumatoide/sangue , Artrite Reumatoide/tratamento farmacológico , Citocinas/sangue , Inflamação/sangue , Síndrome Metabólica/sangue , Nicotinamida Fosforribosiltransferase/sangue , Adulto , Idoso , Antirreumáticos/uso terapêutico , Artrite Reumatoide/epidemiologia , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/epidemiologia , Doença Crônica , Citocinas/imunologia , Feminino , Humanos , Inflamação/epidemiologia , Infliximab , Masculino , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Nicotinamida Fosforribosiltransferase/imunologia , Resistina/sangue , Resistina/imunologia , Fatores de Risco , Índice de Gravidade de Doença , Fator de Necrose Tumoral alfa/antagonistas & inibidores
18.
Clin Exp Rheumatol ; 28(1): 68-72, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20346241

RESUMO

OBJECTIVES: To assess whether the polymorphism of the macrophage migration inhibitory factor (MIF) gene at the position -173 is implicated in the disease susceptibility, risk of cardiovascular (CV) events and presence of subclinical atherosclerosis in patients with rheumatoid arthritis (RA). PATIENTS AND METHODS: A series of 293 unselected patients fulfilling the 1987 American College of Rheumatology classification criteria for RA seen at the rheumatology outpatient clinic of Hospital Xeral-Calde, Lugo, Spain and 526 matched controls were studied for differences in the MIF-173 G/C gene biallelic polymorphism. A total of 182 consecutive patients that had been periodically followed between March 1996 and September 1996 until patient's death or January 1, 2008 were assessed for the presence of CV events. Moreover, between March and December 2007, a subgroup of unselected RA patients with no history of CV events was studied for the presence of subclinical atherosclerosis by the assessment of the endothelial function (n=107) and the carotid artery intima-media thickness (IMT) (n=91) by ultrasonography studies. Patients and controls were genotyped for the MIF-173 G/C gene polymorphism using a PCR system with pre-developed TaqMan allelic discrimination assay. RESULTS: No significant differences in allele or genotype frequencies for the MIF-173 gene polymorphism between RA patients and controls were found. Forty-four of the 182 patients followed between 1996 and January 2008 experienced CV events. Although the frequency of MIF-173 GG homozygous was increased in those who had CV events (88.6%) compared to those who did not suffer these complication (73.2%), the difference was not statistically significant. It was also the case when we analyzed the potential influence of MIF-173 genotypes in the presence of endothelial dysfunction or increased carotid IMT of patients with RA. CONCLUSIONS: Our results do not show that MIF-173 gene polymorphism may infer a direct risk for disease susceptibility or CV disease in patients with RA.


Assuntos
Artrite Reumatoide/epidemiologia , Artrite Reumatoide/genética , Doenças das Artérias Carótidas/epidemiologia , Doenças das Artérias Carótidas/genética , Oxirredutases Intramoleculares/genética , Fatores Inibidores da Migração de Macrófagos/genética , Adulto , Idoso , Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Suscetibilidade a Doenças/epidemiologia , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Fatores de Risco , Espanha/epidemiologia , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Ultrassonografia
19.
Clin Exp Rheumatol ; 27(6): 964-70, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20149313

RESUMO

OBJECTIVE: To determine whether the interleukin (IL)6 -174 gene polymorphism may influence the development of subclinical atherosclerosis manifested by the presence of endothelial dysfunction in RA patients. PATIENTS AND METHODS: 311 patients (228 [73.3%] women; 243 [78.1%] rheumatoid factor positive) who fulfilled the 1987 ACR classification criteria for RA seen at the Rheumatology outpatient clinic of Hospital Xeral-Calde, Lugo between March 1996 and December 2006 and 226 matched controls were included in this study. Between March and December 2007, a subgroup of 98 patients randomly selected was assessed for the presence of endothelial dysfunction. Patients and controls were genotyped for a single biallelic (G/C) nucleotide polymorphism (rs1800795) in the promoter region at the position -174 of the IL6 gene using a TaqMan 5' allele discrimination assay. RESULTS: No significant differences in the IL6 -174 allele or genotype frequency between RA patients and controls were found. However, RA patients homozygous for the IL6 -174 GG genotype had more severe endothelial dysfunction (flow-mediated endothelium-dependent vasodilatation-FMD%: 4.2 + or - 6.6) than those carrying the IL6 -174 GC (FMD%: 6.3 + or - 8.1) or IL6 -174 CC (FMD%: 6.0 + or - 3.3) genotypes. In this regard, significant differences were observed when FMD% values in RA patients carrying the IL6 -174 GG genotype were compared with that observed in those carrying the IL6 -174 GC and the IL6 -174 CC genotypes (FMD%: 6.3 + or - 4.6) (p=0.02). CONCLUSIONS: Our results support a role of IL6 -174 gene polymorphism in the development of subclinical atherosclerosis in patients with RA.


Assuntos
Artrite Reumatoide/genética , Endotélio/fisiopatologia , Interleucina-6/genética , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Adulto , Idoso , Alelos , Artrite Reumatoide/fisiopatologia , Aterosclerose/genética , Aterosclerose/fisiopatologia , Distribuição de Qui-Quadrado , Feminino , Frequência do Gene/genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Índice de Gravidade de Doença
20.
Clin Exp Rheumatol ; 27(2): 222-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19473561

RESUMO

OBJECTIVE: The adipocytokine leptin regulates weight centrally and participates in the regulation of the immune and inflammatory responses. Chronic systemic inflammation is of major importance in the development of atherosclerosis in rheumatoid arthritis (RA). In the present study we investigated whether inflammation, obesity or both of these characteristics are potential determinants of circulating leptin concentrations in a group of RA patients on periodical treatment with the TNF-alpha-blocker-infliximab due to severe disease. We also assessed whether the infusion of infliximab may alter circulating leptin concentrations in patients with severe RA. METHODS: We investigated 33 patients with RA on periodical treatment with infliximab. Serum leptin levels were determined immediately prior to and after infliximab infusion. RESULTS: There was a positive correlation between body mass index of RA patients and baseline serum level of leptin (rho=0.665, p<0.001). Apart from a significant correlation with VCAM-1 (rho=0.349, p=0.04), no significant correlations between baseline leptin levels and the age at the time of the study or at the onset of the disease, disease duration, ESR and CRP levels, DAS28, lipids, insulin sensitivity, adhesion molecules, resistin, adiponectin, ghrelin or the cumulative prednisone dose at the time of the study were found. Leptin levels did not change upon infliximab infusion (p=0.48). CONCLUSION: In RA patients on TNF-alpha blocker treatment, circulating leptin levels are unrelated to disease activity but constitute a manifestation of adiposity. The beneficial effect of anti-TNF-alpha therapy on cardiovascular mortality in RA does not seem to be mediated by reduction in serum levels of leptin.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Artrite Reumatoide/sangue , Artrite Reumatoide/tratamento farmacológico , Leptina/sangue , Obesidade/sangue , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto , Idoso , Artrite Reumatoide/imunologia , Sedimentação Sanguínea , Índice de Massa Corporal , Proteína C-Reativa/análise , Feminino , Humanos , Inflamação/sangue , Infliximab , Leptina/imunologia , Masculino , Pessoa de Meia-Idade
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