1000 resultados para NUCLEAR REACTIONS


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Leprosy inflammatory episodes [type 1 (T1R) and type 2 (T2R) reactions] represent the major cause of irreversible nerve damage. Leprosy serology is known to be influenced by the patient’s bacterial index (BI) with higher positivity in multibacillary patients (MB) and specific multidrug therapy (MDT) reduces antibody production. This study evaluated by ELISA antibody responses to leprosy Infectious Disease Research Institute diagnostic-1 (LID-1) fusion protein and phenolic glycolipid I (PGL-I) in 100 paired serum samples of 50 MB patients collected in the presence/absence of reactions and in nonreactional patients before/after MDT. Patients who presented T2R had a median BI of 3+, while MB patients with T1R and nonreactional patients had median BI of 2.5+ (p > 0.05). Anti-LID-1 and anti-PGL-I antibodies declined in patients diagnosed during T1R (p < 0.05). Anti-LID-1 levels waned in MB with T2R at diagnosis and nonreactional MB patients (p < 0.05). Higher anti-LID-1 levels were seen in patients with T2R at diagnosis (vs. patients with T1R at diagnosis, p = 0.008; vs. nonreactional patients, p = 0.020) and in patients with T2R during MDT (vs. nonreactional MB, p = 0.020). In MB patients, high and persistent anti-LID-1 antibody levels might be a useful tool for clinicians to predict which patients are more susceptible to develop leprosy T2R.

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En aquest treball s’ha fet una avaluació comparativa dels resultats que es poden obtenir amb el software SpectraClassifier 1.0 (SC) desenvolupat al nostre grup de recerca, comparant‐lo amb l’SPSS, un programa estadístic informàtic estàndard, en un problema de classificació de tumors cerebrals humans amb dades d’espectroscopia de ressonància magnètica de protó (1H‐ERM). El interès d’aquesta avaluació comparativa radica en la documentació dels resultats obtinguts amb els dos sistemes quan en la correcció dels resultats obtinguts, així com ponderar la versatilitat i usabilitat dels dos paquets de software per a una aplicació concreta d’interès al treball del GABRMN. Per a aquest treball s’han utilitzat dades provinents de dos projecte europeus multicèntrics (INTERPRET i eTumour) en els quals vam participar. Les classes tumorals utilitzades (d’un total de 217 pacients) han sigut les majoritàries des del punt de vista epidemiològic: glioblastoma multiforme, metàstasi, astrocitomes de grau II, ligodendrogliomes de grau II, oligoastrocitomes de grau II i meningiomes de baix grau. Amb les dades d’aquests pacients s’han dissenyat classificadors basats en l’anàlisi discriminant lineal (LDA), s’han avaluat amb diferents mètodes matemàtics i s’han testat amb dades independents. Els resultats han estat satisfactoris, obtenint amb l’SC resultats més robusts amb dades independents respecte la classificació realitzada per l’SPSS.

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Allergy to nonsteroidal antiinflammatory drugs (NSAIDs) is a very common affliction, especially among patients with asthma and chronic urticaria. These reactions are most often of a non-immunological nature but related to pharmacologic intolerance and linked to arachidonic acid metabolism and leukotriene release. Therefore, crossed reactions implying all non-selective and semi-selective NSAIDs constitute the rule, especially during respiratory reactions to NSAIDs and for patients with chronic urticaria. In isolated acute urticaria, crossed reactions are difficult to predict so caution is necessary. Tolerance induction is possible, especially when aspirin has to be administered in small doses as antiplatelet agent. Finally, acetaminophen and selective NSAIDs as celecoxib are well tolerated by most of these patients. L'allergie aux anti-inflammatoires non stéroïdiens (AINS) est très fréquente, en particulier chez les asthmatiques ou dans l'urticaire chronique. Il s'agit en général de réactions non immunologiques, mais dues à une intolérance pharmacologique liée au métabolisme de l'acide arachidonique et à la formation de leucotriènes. Ainsi, les réactions croisées impliquant tous les AINS non sélectifs et semi-sélectifs sont la règle, surtout lors de réactions respiratoires aux AINS et dans l'urticaire chronique. Lors d'urticaire aiguë isolée, les réactions croisées sont difficiles à prédire, ainsi la prudence s'impose. Une induction de tolérance est possible, en particulier lorsque l'aspirine est nécessaire à dose faible, comme antiagrégant plaquettaire. Enfin, le paracétamol et les AINS sélectifs sont supportés par la grande majorité de ces patients.

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OBJECTIVES We aimed to investigate potential associations between human leukocyte antigen (HLA) class I and class II alleles and the development of anaphylactic/anaphylactoid reactions in patients with multiple sclerosis (MS) treated with natalizumab. METHODS HLA class I and II genotyping was performed in patients with MS who experienced anaphylactic/anaphylactoid reactions and in patients who did not develop infusion-related allergic reactions following natalizumab administration. RESULTS A total of 119 patients with MS from 3 different cohorts were included in the study: 54 with natalizumab-related anaphylactic/anaphylactoid reactions and 65 without allergic reactions. HLA-DRB1*13 and HLA-DRB1*14 alleles were significantly increased in patients who developed anaphylactic/anaphylactoid reactions (p M-H = 3 × 10(-7); odds ratio [OR]M-H = 8.96, 95% confidence interval [CI] = 3.40-23.64), with a positive predictive value (PPV) of 82%. In contrast, the HLA-DRB1*15 allele was significantly more represented in patients who did not develop anaphylactic/anaphylactoid reactions to natalizumab (p M-H = 6 × 10(-4); ORM-H = 0.2, 95% CI = 0.08-0.50), with a PPV of 81%. CONCLUSIONS HLA-DRB1 genotyping before natalizumab treatment may help neurologists to identify patients with MS at risk for developing serious systemic hypersensitivity reactions associated with natalizumab administration.

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One of the world's largest wollastonite deposits was formed at the contact of the northern Hunter Mountain Batholith (California, USA) in Paleozoic sediments. Wollastonite occurs as zones of variable thickness surrounding layers or nodules of quartzite in limestones. A minimum formation temperature of 650 degrees C is estimated from isolated periclase-bearing lenses in that area. Contact metamorphism of siliceous carbonates has produced mineral assemblages that are consistent with heterogeneous, and partly limited infiltration of water-rich fluids, compatible with O-18/O-16 and C-13/C-12 isotopic patterns recorded in carbonates. Oxygen isotope compositions of wollastonites in the study area may also not require infiltration of large quantities of externally-derived fluids that were out of equilibrium with the rocks. 8180 values of wollastonite are high (14.8 parts per thousand to 25.0 parts per thousand; median: 19.7 parts per thousand) and close to those of the host limestone (19.7 parts per thousand to 28 parts per thousand; median: 24.9 parts per thousand) and quartz (18.0 parts per thousand. to 29.1 parts per thousand; median: 22.6 parts per thousand). Isotopic disequilibrium exists at quartz/wollastonite and wollastonite/calcite boundaries. Therefore, classical batch/Rayleigh fractionation models based on reactant and product equilibrium are not applicable to the wollastonite rims. An approach that relies on local instantaneous mass balance for the reactants, based on the wollastonite-forming reaction is suggested as an alternative way to model wollastonite reaction rims. This model reproduces many of the measured delta O-18 values of wollastonite reaction rims of the current study to within +/- 1 parts per thousand, even though the wollastonite compositions vary by almost 10 parts per thousand. (C) 2011 Elsevier B.V. All rights reserved.

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The cellular response to an inflammatory stressor requires a proinflammatory cellular activation followed by a controlled resolution of the response to restore homeostasis. We hypothesized that biliverdin reductase (BVR) by binding biliverdin (BV) quells the cellular response to endotoxin-induced inflammation through phosphorylation of endothelial nitric oxide synthase (eNOS). The generated NO, in turn, nitrosylates BVR, leading to nuclear translocation where BVR binds to the Toll-like receptor-4 (TLR4) promoter at the Ap-1 sites to block transcription. We show in macrophages that BV-induced eNOS phosphorylation (Ser-1177) and NO production are mediated in part by Ca(2+)/calmodulin-dependent kinase kinase. Furthermore, we show that BVR is S-nitrosylated on one of three cysteines and that this posttranslational modification is required for BVR-mediated signaling. BV-induced nuclear translocation of BVR and inhibition of TLR4 expression is lost in macrophages derived from Enos(-/-) mice. In vivo in mice, BV provides protection from acute liver damage and is dependent on the availability of NO. Collectively, we elucidate a mechanism for BVR in regulating the inflammatory response to endotoxin that requires eNOS-derived NO and TLR4 signaling in macrophages.

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We previously reported that nuclear grade assignment of prostate carcinomas is subject to a cognitive bias induced by the tumor architecture. Here, we asked whether this bias is mediated by the non-conscious selection of nuclei that "match the expectation" induced by the inadvertent glance at the tumor architecture. 20 pathologists were asked to grade nuclei in high power fields of 20 prostate carcinomas displayed on a computer screen. Unknown to the pathologists, each carcinoma was shown twice, once before a background of a low grade, tubule-rich carcinoma and once before the background of a high grade, solid carcinoma. Eye tracking allowed to identify which nuclei the pathologists fixated during the 8 second projection period. For all 20 pathologists, nuclear grade assignment was significantly biased by tumor architecture. Pathologists tended to fixate on bigger, darker, and more irregular nuclei when those were projected before kigh grade, solid carcinomas than before low grade, tubule-rich carcinomas (and vice versa). However, the morphometric differences of the selected nuclei accounted for only 11% of the architecture-induced bias, suggesting that it can only to a small part be explained by the unconscious fixation on nuclei that "match the expectation". In conclusion, selection of « matching nuclei » represents an unconscious effort to vindicate the gravitation of nuclear grades towards the tumor architecture.

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Three novel members of the Xenopus nuclear hormone receptor superfamily have been cloned. They are related to each other and similar to the group of receptors that includes those for thyroid hormones, retinoids, and vitamin D3. Their transcriptional activity is regulated by agents causing peroxisome proliferation and carcinogenesis in rodent liver. All three Xenopus receptors activate the promoter of the acyl coenzyme A oxidase gene, which encodes the key enzyme of peroxisomal fatty acid beta-oxidation, via a cognate response element that has been identified. Therefore, peroxisome proliferators may exert their hypolipidemic effects through these receptors, which stimulate the peroxisomal degradation of fatty acids. Finally, the multiplicity of these receptors suggests the existence of hitherto unknown cellular signaling pathways for xenobiotics and putative endogenous ligands.

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An analytic method to evaluate nuclear contributions to electrical properties of polyatomic molecules is presented. Such contributions control changes induced by an electric field on equilibrium geometry (nuclear relaxation contribution) and vibrational motion (vibrational contribution) of a molecular system. Expressions to compute the nuclear contributions have been derived from a power series expansion of the potential energy. These contributions to the electrical properties are given in terms of energy derivatives with respect to normal coordinates, electric field intensity or both. Only one calculation of such derivatives at the field-free equilibrium geometry is required. To show the useful efficiency of the analytical evaluation of electrical properties (the so-called AEEP method), results for calculations on water and pyridine at the SCF/TZ2P and the MP2/TZ2P levels of theory are reported. The results obtained are compared with previous theoretical calculations and with experimental values

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The small nuclear RNA-activating protein complex SNAP(c) is required for transcription of small nuclear RNA genes and binds to a proximal sequence element in their promoters. SNAP(c) contains five types of subunits stably associated with each other. Here we show that one of these polypeptides, SNAP45, also known as PTF delta, localizes to centrosomes during parts of mitosis, as well as to the spindle midzone during anaphase and the mid-body during telophase. Consistent with localization to these mitotic structures, both down- and up-regulation of SNAP45 lead to a G(2)/M arrest with cells displaying abnormal mitotic structures. In contrast, down-regulation of SNAP190, another SNAP(c) subunit, leads to an accumulation of cells with a G(0)/G(1) DNA content. These results are consistent with the proposal that SNAP45 plays two roles in the cell, one as a subunit of the transcription factor SNAP(c) and another as a factor required for proper mitotic progression.

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Through significant developments and progresses in the last two decades, in vivo localized nuclear magnetic resonance spectroscopy (MRS) became a method of choice to probe brain metabolic pathways in a non-invasive way. Beside the measurement of the total concentration of more than 20 metabolites, (1)H MRS can be used to quantify the dynamics of substrate transport across the blood-brain barrier by varying the plasma substrate level. On the other hand, (13)C MRS with the infusion of (13)C-enriched substrates enables the characterization of brain oxidative metabolism and neurotransmission by incorporation of (13)C in the different carbon positions of amino acid neurotransmitters. The quantitative determination of the biochemical reactions involved in these processes requires the use of appropriate metabolic models, whose level of details is strongly related to the amount of data accessible with in vivo MRS. In the present work, we present the different steps involved in the elaboration of a mathematical model of a given brain metabolic process and its application to the experimental data in order to extract quantitative brain metabolic rates. We review the recent advances in the localized measurement of brain glucose transport and compartmentalized brain energy metabolism, and how these reveal mechanistic details on glial support to glutamatergic and GABAergic neurons.

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A simple extended finite field nuclear relaxation procedure for calculating vibrational contributions to degenerate four-wave mixing (also known as the intensity-dependent refractive index) is presented. As a by-product one also obtains the static vibrationally averaged linear polarizability, as well as the first and second hyperpolarizability. The methodology is validated by illustrative calculations on the water molecule. Further possible extensions are suggested

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Electrical property derivative expressions are presented for the nuclear relaxation contribution to static and dynamic (infinite frequency approximation) nonlinear optical properties. For CF4 and SF6, as opposed to HF and CH4, a term that is quadratic in the vibrational anharmonicity (and not previously evaluated for any molecule) makes an important contribution to the static second vibrational hyperpolarizability of CF4 and SF6. A comparison between calculated and experimental values for the difference between the (anisotropic) Kerr effect and electric field induced second-harmonic generation shows that, at the Hartree-Fock level, the nuclear relaxation/infinite frequency approximation gives the correct trend (in the series CH4, CF4, SF6) but is of the order of 50% too small

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The performance of the SAOP potential for the calculation of NMR chemical shifts was evaluated. SAOP results show considerable improvement with respect to previous potentials, like VWN or BP86, at least for the carbon, nitrogen, oxygen, and fluorine chemical shifts. Furthermore, a few NMR calculations carried out on third period atoms (S, P, and Cl) improved when using the SAOP potential

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An overview is given on a study which showed that not only in chemical reactions but also in the favorable case of nontotally symmetric vibrations where the chemical and external potentials keep approximately constant, the generalized maximum hardness principle (GMHP) and generalized minimum polarizability principle (GMPP) may not be obeyed. A method that allows an accurate determination of the nontotally symmetric molecular distortions with more marked GMPP or anti-GMPP character through diagonalization of the polarizability Hessian matrix is introduced