991 resultados para Long-qt Syndrome


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Osler-Weber-Rendu syndrome (OWRS) is a rare hereditary, autosomal dominant disease characterized by a local angiodysplasia. Its clinical characteristics are vascular hamartomas of the skin and oral mucosa, arteriovenous malformations in the lungs, liver, kidney and brain, and episodes of epistaxis. The oral lesions, which become apparent through hemorrhagic telangiectasia, may be the first sign of the disease. This is a case report of a 74-year-old woman whose diagnosis of OWRS was established by her dentist based on the presence of telangiectasia in the skin and oral mucosa, reports of frequent nosebleeds of unknown etiology and a family history of telangiectasia. Amputation of a lower limb and comorbidities, such as cardiopathy, nephropathy and rheumatic disorders, completed the profile. OWRS causes major vascular changes that can be diagnosed initially by a dentist. In this article, we describe the skills and knowledge that dentists need to monitor patients with OWRS properly.

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Background and Objective: Stevens-Johnson syndrome (SJS) is a life-threatening dermatosis characterized by epidermal sloughing and stomatitis. We report the case of a 7-year-old boy in whom laser phototherapy (LPT) was highly effective in reversing the effects of an initial episode of SJS that had apparently developed in association with treatment with phenobarbital for a seizure disorder. The patient was first seen in the intensive care unit (ICU) of our institution with fever, cutaneous lesions on his extremities, trunk, face, and neck; mucosal involvement of his genitalia and eyes (conjunctivitis); ulcerative intraoral lesions; and swollen, crusted, and bleeding lips. He reported severe pain at the sites of his intraoral and skin lesions and was unable to eat, speak, swallow, or open his mouth. Materials and Methods: Trying to prevent and minimize secondary infections, gastric problems, pain, and other complications, the patient was given clindamycin, ranitidine, dipyrone, diphenhydramine (Benadryl) drops, and morphine. In addition, he was instructed to use bicarbonate solution and Ketoconazole (Xylogel) in the oral cavity. Because of the lack of progress of the patient, the LPT was selected. Results: At 5 days after the initial session of LPT, the patient was able to eat gelatin, and on the following day, the number and severity of his intraoral lesions and his labial crusting and swelling had diminished. By 6 days after his initial session of LPT, most of the patient's intraoral lesions had disappeared, and the few that remained were painless; the patient was able to eat solid food by himself and was removed from the ICU. Ten sessions of LPT were conducted in the hospital. The patient underwent three further and consecutive sessions at the School of Dentistry, when complete healing of his oral lesions was observed. Conclusion: The outcome in this case suggests that LPT may be a new adjuvant modality for SJS complications.

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Background: The American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI), revising the National Cholesterol Evaluation Program for Adult Treatment Panel III (NCEP ATP III), and the International Diabetes Federation (IDF) have proposed definitions of metabolic syndrome that take into account waist circumference thresholds according to ethnicity. In this study we estimated the prevalence of metabolic syndrome in a Japanese-Brazilian population using NCEP definitions for Westerners (NCEPwe) and Asians (NCEPas), and IDF for Japanese (IDF). Methods: A total of 650 Japanese-Brazilians living in a developed Brazilian city and aged 30-88 years were included. Results: Metabolic syndrome prevalence according to NCEPwe, NCEPas, and IDF was, respectively, 46.5%, 56.5%, and 48.3%. Only 43.5% of subjects did not have metabolic syndrome by any of the 3 definitions, and 38.3% fulfilled metabolic syndrome criteria for all 3 definitions. Ten percent of subjects were positive for metabolic syndrome based on NCEPas and IDF, but not for NCEPwe. Because IDF requires abdominal obesity as a criterion, the frequency of subjects without metabolic syndrome according to IDF, but with metabolic syndrome by NCEPwe and NCEPas was 8.2%. Conclusions: Independent of the metabolic syndrome definition, Japanese-Brazilians present an elevated metabolic syndrome prevalence, which was higher when using NCEP criteria for Asians, followed by the IDF definition for Japanese.

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The most relevant clinical trials, assessing the role of glycemic control in reducing cardiovascular risk, are examined. The UKPDS was the first to address this issue. More recent trials (ACCORD, ADVANCE and VADT) are controversial and evidences did not support that strict glycemic control (reflected by normal glycated hemoglobin) exclusively is sufficient to reduce cardiovascular risk in complicated individuals with long-term type 2 diabetes mellitus. Some possible reasons for controversies are included.

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Context. Emission lines formed in decretion disks of Be stars often undergo long-term cyclic variations, especially in the violet-to-red (V/R) ratio of their primary components. The underlying structural and dynamical variations of the disks are only partly understood. From observations of the bright Be-shell star. Tau, the possibly broadest and longest data set illustrating the prototype of this behaviour was compiled from our own and archival observations. It comprises optical and infrared spectra, broad-band polarimetry, and interferometric observations. Aims. The dense, long-time monitoring permits a better separation of repetitive and ephemeral variations. The broad wavelength coverage includes lines formed under different physical conditions, i.e. different locations in the disk, so that the dynamics can be probed throughout much of the disk. Polarimetry and interferometry constrain the spatial structure. All together, the objective is a better understand the dynamics and life cycle of decretion disks. Methods. Standard methods of data acquisition, reduction, and analysis were applied. Results. From 3 V/R cycles between 1997 and 2008, a mean cycle length in Ha of 1400-1430 days was derived. After each minimum in V/R, the shell absorption weakens and splits into two components, leading to 3 emission peaks. This phase may make the strongest contribution to the variability in cycle length. There is no obvious connection between the V/R cycle and the 133-day orbital period of the not otherwise detected companion. V/R curves of different lines are shifted in phase. Lines formed on average closer to the central star are ahead of the others. The shell absorption lines fall into 2 categories differing in line width, ionization/excitation potential, and variability of the equivalent width. They seem to form in separate regions of the disk, probably crossing the line of sight at different times. The interferometry has resolved the continuum and the line emission in Br gamma and HeI 2.06. The phasing of the Br gamma emission shows that the photocenter of the line-emitting region lies within the plane of the disk but is offset from the continuum source. The plane of the disk is constant throughout the observed V/R cycles. The observations lay the foundation for the fully self-consistent, one-armed, disk-oscillation model developed in Paper II.

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Background: Endothelial cells are of great interest for cell therapy and tissue engineering. Understanding the heterogeneity among cell lines originating from different sources and culture protocols may allow more standardized material to be obtained. In a recent paper, we showed that adrenalectomy interferes with the expression of membrane adhesion molecules on endothelial cells maintained in culture for 16 to 18 days. In addition, the pineal hormone, melatonin, reduces the adhesion of neutrophils to post-capillary veins in rats. Here, we evaluated whether the reactivity of cultured endothelial cells maintained for more than two weeks in culture is inversely correlated to plasma melatonin concentration. Methodology/Principal Findings: The nocturnal levels of melatonin were manipulated by treating rats with LPS. Nocturnal plasma melatonin, significantly reduced two hours after LPS treatment, returned to control levels after six hours. Endothelial cells obtained from animals that had lower nocturnal melatonin levels significantly express enhanced adhesion molecules and iNOS, and have more leukocytes adhered than cells from animals that had normal nocturnal levels of melatonin (naive or injected with vehicle). Endothelial cells from animals sacrificed two hours after a simultaneous injection of LPS and melatonin present similar phenotype and function than those obtained fromcontrol animals. Analyzing together all the data, taking into account the plasma melatonin concentration versus the expression of adhesion molecules or iNOS we detected a significant inverse correlation. Conclusions/Significance: Our data strongly suggest that the plasma melatonin level primes endothelial cells ""in vivo,"" indicating that the state of the donor animal is translated to cells in culture and therefore, should be considered for establishing cell banks in ideal conditions.

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Objective: To evaluate the potential of 980-nm gallium aluminum arsenide (GaAlAs) and 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers to reduce bacteria after irradiation of implant surfaces contaminated with Enterococcus faecalis and Porphyromonas gingivalis and on irradiated implant surface morphology. Background: Despite the frequency of implant success, some implant loss is related to peri-implantitis because of difficulty in eliminating the biofilm. Methods: Implants (3.75 x 13 mm) with machined surfaces, surfaces sand blasted with titanium oxide (TiO(2)), and sand-blasted and acid-etched surfaces were exposed to P. gingivalis and E. faecalis cultures and irradiated with 980-nm GaAlAs or 1064-nm Nd: YAG lasers. After laser treatments, the number of remaining colony-forming units and implant surface morphology were analyzed using scanning electron microscopy (SEM). Results: The Nd: YAG laser was able to promote a total contamination reduction on all implants irradiated. The results with the GaAlAs laser showed 100% bacteria reduction on the implants irradiated with 3 W. Irradiation with 2.5 W and 3 W achieved 100% of bacteria reduction on P. gingivalis-contaminated implants. Decontamination was not complete for the sand-blasted TiO(2) (78.6%) and acid-etched surfaces (49.4%) contaminated with E. faecalis and irradiated with 2.5 W. SEM showed no implant surface changes. Conclusion: The wavelengths used in this research provided bacteria reduction without damaging implant surfaces. New clinical research should be encouraged for the use of this technology in the treatment of peri-implantitis.

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A search for depletion of the combined flux of active neutrino species over a 735 km baseline is reported using neutral-current interaction data recorded by the MINOS detectors in the NuMI neutrino beam. Such a depletion is not expected according to conventional interpretations of neutrino oscillation data involving the three known neutrino flavors. A depletion would be a signature of oscillations or decay to postulated noninteracting sterile neutrinos, scenarios not ruled out by existing data. From an exposure of 3.18 x 10(20) protons on target in which neutrinos of energies between similar to 500 MeV and 120 GeV are produced predominantly as nu(mu), the visible energy spectrum of candidate neutral-current reactions in the MINOS far detector is reconstructed. Comparison of this spectrum to that inferred from a similarly selected near-detector sample shows that of the portion of the nu(mu) flux observed to disappear in charged-current interaction data, the fraction that could be converting to a sterile state is less than 52% at 90% confidence level (C. L.). The hypothesis that active neutrinos mix with a single sterile neutrino via oscillations is tested by fitting the data to various models. In the particular four-neutrino models considered, the mixing angles theta(24) and theta(34) are constrained to be less than 11 degrees and 56 degrees at 90% C. L., respectively. The possibility that active neutrinos may decay to sterile neutrinos is also investigated. Pure neutrino decay without oscillations is ruled out at 5.4 standard deviations. For the scenario in which active neutrinos decay into sterile states concurrently with neutrino oscillations, a lower limit is established for the neutrino decay lifetime tau(3)/m(3) > 2.1 x 10(-12) s/eV at 90% C.L.

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We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.

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We report the first three-particle coincidence measurement in pseudorapidity (Delta eta) between a high transverse momentum (p(perpendicular to)) trigger particle and two lower p(perpendicular to) associated particles within azimuth |Delta phi| < 0.7 in root s(NN) = 200 GeV d + Au and Au + Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Delta eta correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Delta eta. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

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The STAR Collaboration at the Relativistic Heavy Ion Collider presents a systematic study of high-transverse-momentum charged-di-hadron correlations at small azimuthal pair separation Delta phi in d+Au and central Au+Au collisions at s(NN)=200 GeV. Significant correlated yield for pairs with large longitudinal separation Delta eta is observed in central Au+Au collisions, in contrast to d+Au collisions. The associated yield distribution in Delta eta x Delta phi can be decomposed into a narrow jet-like peak at small angular separation which has a similar shape to that found in d+Au collisions, and a component that is narrow in Delta phi and depends only weakly on Delta eta, the ""ridge."" Using two systematically independent determinations of the background normalization and shape, finite ridge yield is found to persist for trigger p(t)>6 GeV/c, indicating that it is correlated with jet production. The transverse-momentum spectrum of hadrons comprising the ridge is found to be similar to that of bulk particle production in the measured range (2 < p(t)< 4 GeV/c).

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Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at root s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

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Dictated by the string theory and various higher dimensional scenarios, black holes in D > 4-dimensional space-times must have higher curvature corrections. The first and dominant term is quadratic in curvature, and called the Gauss-Bonnet (GB) term. We shall show that although the Gauss-Bonnet correction changes black hole's geometry only softly, the emission of gravitons is suppressed by many orders even at quite small values of the GB coupling. The huge suppression of the graviton emission is due to the multiplication of the two effects: the quick cooling of the black hole when one turns on the GB coupling and the exponential decreasing of the gray-body factor of the tensor type of gravitons at small and moderate energies. At higher D the tensor gravitons emission is dominant, so that the overall lifetime of black holes with Gauss-Bonnet corrections is many orders larger than was expected. This effect should be relevant for the future experiments at the Large Hadron Collider (LHC).

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In this work, we investigated the temperature dependence of short and long-range ferroelectric ordering in Pb(0.55)La(0.30)TiO(3) relaxor composition. High-resolution x-ray powder diffraction measurements revealed a clear spontaneous macroscopic cubic-to-tetragonal phase transition in the PLT relaxor sample at similar to 60 K below the maximum of the dielectric constant peak (T(m)). Indeed, the x-ray diffraction (XRD) data showed that at 300 K (above T(m) but below the Burns temperature, T(B)) the long-range order structure corresponds to a macroscopic cubic symmetry, space group number 221 (Pm-3m), whereas the data collected at 20 K revealed a macroscopic tetragonal symmetry, space group number 99 (P4mm) with c/a=1.0078, that is comparable to that of a normal ferroelectric. These results show that for samples with tetragonal composition, the long-range ferroelectric order may be recovered spontaneously at cryogenics temperatures, in contrast to ferroelectric samples with rhombohedral symmetry. On the other hand, x-ray absorption spectroscopy investigations intriguingly revealed the existence of local tetragonal disorder around Ti atoms for temperatures far below T(m) and above T(B), for which the sample presents macroscopic tetragonal and cubic symmetries, respectively. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3431024]

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Using path-integral Monte Carlo calculations, we have calculated ring exchange frequencies in the bcc phase of solid (3)He for densities from melting to the highest stable density. We evaluate 42 different exchange frequencies from two atoms up to eight atoms and find their Gruneisen exponents. Using a fit to these frequencies, we calculate the contribution to the Curie-Weiss temperature, Theta(CW), and upper critical magnetic field, B(c2), for even longer exchanges using a lattice Monte Carlo procedure. We find that contributions from seven-and eight-particle exchanges make a significant contribution to Theta(CW) and B(c2) at melting density. Comparison with experimental data is given.