190 resultados para segment QT
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OBJECTIVES: To compare the use of guideline-recommended medical and interventional therapies in older and younger patients with acute coronary syndromes (ACSs). DESIGN: Prospective cohort study. SETTING: Fifty-five hospitals in Switzerland. PARTICIPANTS: Eleven thousand nine hundred thirty-two patients with ACS enrolled between March 1, 2001, and June 30, 2006. ACS definition included ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI), and unstable angina pectoris (UA). MEASUREMENTS: Use of medical and interventional therapies was determined after exclusion of patients with contraindications and after adjustment for comorbidities. Multivariate logistic regression models were used to calculate odds ratios (ORs) per year increase in age. RESULTS: Elderly patients were less likely to receive acetylsalicylic acid (OR=0.976, 95% confidence interval (CI)=0.969-0.980) or beta-blockers (OR=0.985, 95% CI=0.981-0.989). No age-dependent difference was found for heparin use. Elderly patients with STEMI were less likely to receive percutaneous coronary intervention (PCI) or thrombolysis (OR=0.955, 95% CI=0.949-0.961). Elderly patients with NSTEMI or UA less often underwent PCI (OR=0.943, 95% CI=0.937-0.949). CONCLUSION: Elderly patients across the whole spectrum of ACS were less likely to receive guideline-recommended therapies, even after adequate adjustment for comorbidities. Prognosis of elderly patients with ACS may be improved by increasing adherence to guideline-recommended medical and interventional therapies.
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Average life expectancy reached 78.8 years in Europe in 2002 (WHO 2003); most Europeans can, therefore, now anticipate living well past 75 years of age. Projections in industrialized nations suggest a continuing mortality decline in the next decades 1 while birth rates will probably continue to decline, resulting in further ageing of these nations. As those aged 80 years and over are the fastest expanding segment of the older population, concerns are growing about a potential dramatic increase in the number of disabled persons. The ageing of the population and the related increase in chronic disease burden have already had major impacts on most Western health-care systems, and will probably further affect these systems in the future as the baby-boom generation becomes older. For instance, in Switzerland, it is estimated that costs due to long-term care could more than double by 2030, from 6.5 to 15.3 billion SFr.2 Similar trends are expected in most European countries. As a consequence, postponement of the onset of disability, with a compression of functional dependency into a shorter period towards the end of life, is becoming a major goal. To successfully achieve this goal and improve the control of growing health and social care expenditures, various strategies of health promotion and disease prevention are developed and tested. Although several of these experiences had some effects on functional decline and institutional placement, they have not been shown to be cost-effective. Additional strategies are, therefore, needed to prevent or delay the onset of disability in older persons, reduce functional impairment, and face the challenge of an increasing disabled elderly population.
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BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disease for which electrophysiological studies (EPS) have shown to be of limited value.OBJECTIVE This study presents a CPVT family in which marked postpacing repolarization abnormalities during EPS were the only consistent phenotypic manifestation of ryanodine receptor (RyR2) mutation carriers.METHODS The study was prompted by the observation of transient marked QT prolongation preceding initiation of ventricular fibrillation during atrial fibrillation in a boy with a family history of sudden cardiac death (SCD). Family members underwent exercise and pharmacologic electrocardiographic testing with epinephrine, adenosine, and flecainide. Noninvasive clinical test results were normal in 10 patients evaluated, except for both epinephrine- and exercise-induced ventricular arrhythmias in 1. EPS included bursts of ventricular pacing and programmed ventricular extrastimulation reproducing short-long sequences. Genetic screening involved direct sequencing of genes involved in long QT syndrome as well as RyR2.RESULTS Six patients demonstrated a marked increase in QT interval only in the first beat after cessation of ventricular pacing and/or extrastimulation. All 6 patients were found to have a heterozygous missense mutation (M4109R) in RyR2. Two of them, presenting with aborted SCD, also had a second missense mutation (I406T- RyR2). Four family members without RyR2 mutations did not display prominent postpacing QT changes.CONCLUSION M4109R- RyR2 is associated with a high incidence of SCD. The contribution of I406T to the clinical phenotype is unclear. In contrast to exercise testing, marked postpacing repolarization changes in a single beat accurately predicted carriers of M4109R- RyR2 in this family.
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Homologous desensitization and internalization of the GLP-1 receptor correlate with phosphorylation of the receptor in a 33-amino acid segment of the cytoplasmic tail. Here, we identify the sites of phosphorylation as being three serine doublets located at positions 441/442, 444/445, and 451/452. The role of phosphorylation on homologous desensitization was assessed after stable expression in fibroblasts of the wild type or of mutant receptors in which phosphorylation sites were changed in various combinations to alanines. We showed that desensitization, as measured by a decrease in the maximal production of cAMP after a first exposure of the cells to GLP-1, was strictly dependent on phosphorylation. Furthermore, the number of phosphorylation sites correlated with the extent of desensitization with no, intermediate, or maximal desensitization observed in the presence of one, two, or three phosphorylation sites, respectively. Internalization of the receptor-ligand complex was assessed by measuring the rate of internalization of bound [125I]GLP-1 or the redistribution of the receptor to an endosomal compartment after agonist binding. Our data demonstrate that internalization was prevented in the absence of receptor phosphorylation and that intermediate rates of endocytosis were obtained with receptors containing one or two phosphorylation sites. Thus, homologous desensitization and internalization require phosphorylation of the receptor at the same three sites. However, the differential quantitative impairment of these two processes in the single and double mutants suggests different molecular mechanisms controlling desensitization and internalization.
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Retinitis pigmentosa (RP) is a degenerative disease of the retina leading to progressive loss of vision and, in many instances, to legal blindness at the end stage. The RP28 locus was assigned in 1999 to the short arm of chromosome 2 by homozygosity mapping in a large Indian family segregating autosomal-recessive RP (arRP). Following a combined approach of chromatin immunoprecipitation and parallel sequencing of genomic DNA, we identified a gene, FAM161A, which was shown to carry a homozygous nonsense mutation (p.Arg229X) in patients from the original RP28 pedigree. Another homozygous FAM161A stop mutation (p.Arg437X) was detected in three subjects from a cohort of 118 apparently unrelated German RP patients. Age at disease onset in these patients was in the second to third decade, with severe visual handicap in the fifth decade and legal blindness in the sixth to seventh decades. FAM161A is a phylogenetically conserved gene, expressed in the retina at relatively high levels and encoding a putative 76 kDa protein of unknown function. In the mouse retina, Fam161a mRNA is developmentally regulated and controlled by the transcription factor Crx, as demonstrated by chromatin immunoprecipitation and organotypic reporter assays on explanted retinas. Fam161a protein localizes to photoreceptor cells during development, and in adult animals it is present in the inner segment as well as the outer plexiform layer of the retina, the synaptic interface between photoreceptors and their efferent neurons. Taken together, our data indicate that null mutations in FAM161A are responsible for the RP28-associated arRP.
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A new method of measuring joint angle using a combination of accelerometers and gyroscopes is presented. The method proposes a minimal sensor configuration with one sensor module mounted on each segment. The model is based on estimating the acceleration of the joint center of rotation by placing a pair of virtual sensors on the adjacent segments at the center of rotation. In the proposed technique, joint angles are found without the need for integration, so absolute angles can be obtained which are free from any source of drift. The model considers anatomical aspects and is personalized for each subject prior to each measurement. The method was validated by measuring knee flexion-extension angles of eight subjects, walking at three different speeds, and comparing the results with a reference motion measurement system. The results are very close to those of the reference system presenting very small errors (rms = 1.3, mean = 0.2, SD = 1.1 deg) and excellent correlation coefficients (0.997). The algorithm is able to provide joint angles in real-time, and ready for use in gait analysis. Technically, the system is portable, easily mountable, and can be used for long term monitoring without hindrance to natural activities.
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INTRODUCTION: The presence of a pre-existing narrow spinal canal may have an important place in the ethiopathogenesis of lumbar spinal stenosis. By consequence the study of the development of the spinal canal is crucial. The first goal of this work is to do a comprehensive literature search and to give an essential view on the development of spinal canal and its depending factors studied until now. The second goal is to give some considerations and hypothesize new leads for clinically useful researches. MATERIALS AND METHODS: A bibliographical research was executed using different search engines: PubMed, Google Schoolar ©, Ovid ® and Web Of Science ©. Free sources and avaible from the University of Lausanne (UNIL) and Centre Hospitalier Universitaire Vaudois (CHUV) were used. At the end of the bibliographic researches 114 references were found, 85 were free access and just 41 were cited in this work. Most of the found references are in English or in French. RESULTS AND DISCUSSION: The spinal canal is principally limited by the vertebrae which have a mesodermal origin. The nervous (ectodermal) tissue significantly influences the growth of the canal. The most important structure participating in the spinal canal growth is the neurocentral synchondrosis in almost the entire vertebral column. The fusion of the half posterior arches seems to have less importance for the canal size. The growth is not homogeneous but, depends on the vertebral level. Timing, rate and growth potentials differ by regions. Especially in the case of the lumbar segment, there is a craniocaudal tendency which entails a greater post-natal catch-up growth for distal vertebrae. Trefoil-shape of the L5 canal is the consequence of a sagittal growth deficiency. The spinal canal shares some developmental characteristics with different structures and systems, especially with the central nervous system. It may be the consequence of the embryological origin. It is supposed that not all the related structures would be affected by a growth impairment because of the different catch-up potentials. Studies found that narrower spinal canals might be related with cardiovascular and gastrointestinal symptoms, lower thymic function, bone mineral content, dental hypoplasia and Harris' lines. Anthropometric correlations found at birth disappear during the pediatric age. All factors which can affect bone and nervous growth might be relevant. Genetic predispositions are the only factors that can never be changed but the real impact is to ascertain. During the antenatal period, all the elements determining a good supply of blood and oxygen may influence the vertebral canal development, for example smoking during pregnancy. Diet is a crucial factor having an impact on both antenatal and postnatal growth. Proteins intake is the only proved dietetic relationship found in the bibliographic research of this work. The mechanical effects due to locomotion changes are unknown. Socioeconomic situation has an impact on several influencing factors and it is difficult to study it owing to numerous bias. CONCLUSIONS: A correct growth of spinal canal is evidently relevant to prevent not-degenerative stenotic conditions. But a "congenital" narrower canal may aggravate degenerative stenosis. This concerns specific groups of patient. If the size of the canal is highly involved in the pathogenesis of common back pains, a hypothetical measure to prevent developmental impairments could have a not- negligible impact on the society. It would be interesting to study more about dietetic necessities for a good spinal canal development. Understanding the relationship between nervous tissues and vertebra it might be useful in identifying what is needed for the ideal development. Genetic importance and the post-natal influences of upright standing on the canal growth remain unsolved questions. All these tracks may have a double purpose: knowing if it is possible to decrease the incidence of narrower spinal canal and consequently finding possible preventive measures. The development of vertebral canal is a complex subject which ranges over a wide variety of fields. The knowledge of this subject is an indispensable tool to understand and hypothesize the influencing factors that might lead to stenotic conditions. Unfortunately, a lack of information makes difficult to have a complete and satisfactory interdisciplinary vision.
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We have identified new malaria vaccine candidates through the combination of bioinformatics prediction of stable protein domains in the Plasmodium falciparum genome, chemical synthesis of polypeptides, in vitro biological functional assays, and association of an antigen-specific antibody response with protection against clinical malaria. Within the predicted open reading frame of P. falciparum hypothetical protein PFF0165c, several segments with low hydrophobic amino acid content, which are likely to be intrinsically unstructured, were identified. The synthetic peptide corresponding to one such segment (P27A) was well recognized by sera and peripheral blood mononuclear cells of adults living in different regions where malaria is endemic. High antibody titers were induced in different strains of mice and in rabbits immunized with the polypeptide formulated with different adjuvants. These antibodies recognized native epitopes in P. falciparum-infected erythrocytes, formed distinct bands in Western blots, and were inhibitory in an in vitro antibody-dependent cellular inhibition parasite-growth assay. The immunological properties of P27A, together with its low polymorphism and association with clinical protection from malaria in humans, warrant its further development as a malaria vaccine candidate.
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The terminal segment of the intermediate hair in the semi-aquatic Chirmarrogale hantu and Bectigale elegans is investigated with a view to a taxonomic interpretation. Nectogale is characterized by especially fine hairs which strongly contrast with the distally thickened hairs of Chimarrogale. In spite of these differences, the hairs of both genera are characterized by a H-shaped profile. According to Vogel & Köpchen (1977), this criterion confirms the discussed membership to the Soricinae.
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Cocaine is a well known trigger of acute coronary syndromes. Over the last 10 years levamisole, a veterinary anthelminthic drug has been increasingly used as an adulterant of cocaine. Levamisole was used to treat pediatric nephritic syndrome and rheumatoid arthritis before being withdrawn from the market due to its significant toxicity, i.e. hematological complications and vasculitis. The major complications of levamisole-adultered cocaine reported up to now are hematological and dermatological. The case reported here is of a 25 year old man with a history of cocaine abuse who died at home after complaining of retrosternal pain. Postmortem CT-angiography, autopsy, and chemical and toxicological analyses were performed. An eroded coronary artery plaque was found at the proximal segment of the left anterior descending coronary artery. Two myocardial infarct scars were present in the left ventricle. Microscopic examination of the coronary artery revealed infiltration of eosinophils into the adventitia and intima. Toxicological examination confirmed the presence of cocaine and its metabolites in the peripheral blood, and of levamisole in the urine and pericardial fluid. Eosinophilic inflammatory coronary artery pathologies have been clinically linked to coronary dissection, hypersensitivity coronary syndrome and vasospastic allergic angina. The coronary pathology in the presented case could be a complication of levamisole-adultered cocaine use, in which an allergic or immune-mediated mechanism might play a role. The rise in cocaine addiction worldwide and the increase of levamisole adulterated cocaine highlights the importance of updating our knowledge of the effects of adultered cocaine abuse.