457 research outputs found
Efficacy of beta-blocker therapy in symptomatic athletes with exercise-induced intra-ventricular gradients
<p>Abstract</p> <p>Background</p> <p>Upright exercise stress echocardiography (SE) induces significant intraventricular gradient (IVG) and systolic anterior motion (SAM) in a large proportion of symptomatic athletes, who may therefore benefit from a negative inotropic therapy.</p> <p>The purpose of the present study was to assess the effect of chronic oral β blocker therapy on the occurrence of exercise-induced IVG and mitral valve SAM, in symptomatic athletes.</p> <p>Methods</p> <p>We enrolled 35 symptomatic athletes (age = 23 ± 11 years) with IVG (>30 mmHg) during SE off therapy. All repeated SE on chronic oral beta-blocker therapy (atenolol up to 50 mg, bisoprolol up to 10 mg, or metoprolol up to 100 mg daily according to physician-driven choice).</p> <p>Results</p> <p>On therapy, there was during SE a reduction in IVG (35 off vs 17 on beta blocker, p < 0.01), decrease of IVG (102 ± 34 mmHg off vs 69 ± 24 mmHg on beta blocker, p < 0.01), peak heart rate (178 ± 15 bpm off vs 157 ± 9 bpm on beta blocker), SAM (24 off vs 9 on beta blocker, p < 0.001), symptoms during SE (17 off vs 2 on beta blocker p < 0.001), ST segment depression (13 off vs 2 on beta blocker, p < 0.001).</p> <p>Conclusions</p> <p>In athletes with positive screening on medical evaluation for sports practice and IVG on exertion, treatment with oral beta blockers improved symptoms in the large majority of patients. Symptomatic benefit was mirrored by objective evidence of improvement of echocardiographic signs of obstruction (IVG and SAM) and reduction of ischemia-like electrocardiographic changes.</p
Clinical significance of intraventricular gradient during effort in an adolescent karate player
The authors report the case of a 16-year-old boy who practices karate, who underwent medical evaluation because of atypical chest discomfort, related to strenuous effort. The ECG and echocardiogram findings were normal. The young boy did a treadmill stress test which was positive for myocardial ischemia. Late during the investigation, he underwent treadmill stress echocardiography, during which he developed intraventricular gradient of over 130 mmHg with end-systolic peak and systolic anterior movement (SAM) of the mitral valve. These echocardiographic findings were not present at rest and disappeared shortly after termination of exercise. The authors discuss the significance of this event. This leads us to advise withdrawal from participation in competitive sport according to the recomendations of the European Society of Cardiology. A possible role of exercise stress echo for intraventricular pressure gradient assessment in symptomatic athletes with structurally normal hearts is suggested
Exercise-induced intra-ventricular gradients as a frequent potential cause of myocardial ischemia in cardiac syndrome X patients
<p>Abstract</p> <p>Background</p> <p>The development of intra-ventricular gradients (IVG) during dobutamine or exercise stress is not infrequent, and can be associated to symptoms during stress.</p> <p>The purpose of this study was to assess the occurrence of IVG during exercise stress echocardiography in cardiac syndrome X patients.</p> <p>Methods</p> <p>We prospectively evaluated 91 patients (pts) mean aged 51 ± 12 years (age ranged 20 to 75 years old), 44 of whom were women. All pts had angina, positive exercise ECG treadmill testing, normal rest echocardiogram and no coronary artery disease on coronary angiogram (cardiac X syndrome). After complete Doppler echocardiographic evaluation with determination of left ventricular outflow tract index (LVOTi), relative left ventricular wall thickness (RLVWT) and left ventricular end-diastolic volume index (LVDVi), all patients underwent stress echocardiography with two-dimensional and Doppler echographic evaluation during and after treadmill exercise.</p> <p>Results</p> <p>For analysis purpose patients were divided in 2 groups, according to the development of IVG. Doppler evidence of IVG was found in 33 (36%) of the patients (Group A), with mean age 47 ± 14 years old (age ranged 20 to 72 years) and with a mean end-systolic peak gradient of 86 ± 34 mmHg (ranging from 30 to 165 mmHg). The IVG development was accompanied by SAM of the mitral valve in 23 pts. Three of these pts experienced symptomatic hypotension. Ten were women (30% pts). 58 pts in group B, 34 of whom were women (59%) (p = 0,01 vs group A), mean aged 53,5 ± 10,9 years old (age ranged 34 to 75 years) (p = 0,03 vs group A), did not develop IVG. LVOTi was 10,29 ± 0,9 mm/m<sup>2 </sup>in group A and 11,4 ± 1 mm/m<sup>2 </sup>in group B (p < 0,000); RLVWT was 0,36 ± 0,068 in group A and 0,33 ± 0,046 in group B (p < 0,01); LVDVi was 44,8 ± 10 ml/m<sup>2 </sup>in group A and 56 ± 11,6 ml/m<sup>2 </sup>in group B (p = 0,000).</p> <p>Conclusion</p> <p>1. A significant number of patients with cardiac X syndrome developed IVG during upright exercise in treadmill. These pts (group A) are mainly males and younger than those who did not develop IVG.</p> <p>2. The development of IVG and mitral valve SAM on exertion seems to be associated with ST segment downsloping during stress testing in patients without epicardial coronary disease.</p> <p>3. The development of IVG and mitral valve SAM seems to be associated with lower LVOTi, lower LVDVi and higher RLVWT.</p
Exercise-Induced Intraventricular Obstruction in a Child with Near Syncope and Chest Pain During Exercise
We report the case of a 10-year-old girl with two episodes of light-headedness and chest pain during exercise. She had an unremarkable clinical record, physical examination, ECG, and echocardiogram. Noninvasive ischemia tests were positive, but coronary angiography was normal. Exercise stress echocardiogram revealed an exercise-induced intra-left-ventricular obstruction with a peak gradient of 78 mmHg and replicated her symptoms. After starting beta-blocker therapy her clinical status improved and no residual obstruction was detected. The authors review this unsuspected clinical condition, seldom reported in the adult population and, to our knowledge, never before in a child
Mapping of a Leishmania major gene/locus that confers pentamidine resistance by deletion and insertion of transposable element
Pentamidine (PEN) is an alternative compound to treat antimony-resistant leishmaniasis patients, which cellular target remains unclear. One approach to the identification of prospective targets is to identify genes able to mediate PEN resistance following overexpression. Starting from a genomic library of transfected parasites bearing a multicopy episomal cosmid vector containing wild-type Leishmania major DNA, we isolated one locus capable to render PEN resistance to wild type cells after DNA transfection. In order to map this Leishmania locus, cosmid insert was deleted by two successive sets of partial digestion with restriction enzymes, followed by transfection into wild type cells, overexpression, induction and functional tests in the presence of PEN. To determine the Leishmania gene related to PEN resistance, nucleotide sequencing experiments were done through insertion of the transposon Mariner element of Drosophila melanogaster (mosK) into the deleted insert to work as primer island. Using general molecular techniques, we described here this method that permits a quickly identification of a functional gene facilitating nucleotide sequence experiments from large DNA fragments. Followed experiments revealed the presence of a P-Glycoprotein gene in this locus which role in Leishmania metabolism has now been analyzed.A Pentamidina (PEN) é um composto alternativo para o tratamento de pacientes com leishmaniose que apresentam resistência ao antimônio, cujo alvo celular continua incerto. Uma abordagem para se identificar prováveis alvos seria a identificação e super-expressão de genes capazes de mediar resistência a PEN. A partir de uma genoteca construÃda com o DNA de Leishmania major em um vetor - cosmÃdio que se desenvolve tanto em bactérias como nas células do parasita, isolamos um locus que após transfecção é capaz de produzir resistência a PEN à s células do parasita. Almejando o mapeamento desse locus de leishmania, o inserto clonado nesse cosmÃdio foi deletado através de duas digestões parciais sucessivas com enzimas de restrição, seguida de transfecção em células selvagens, super-expressão gênica, indução e testes funcionais na presença de PEN. Para determinar o gene de Leishmania relacionado com a resistência a PEN, o seqüenciamento de nucleotÃdeos foi executado após inserção de elementos transposicionais de Drosophila melanogaster no interior do inserto deletado para atuar como 'ilhas de iniciadores'. Descrevemos aqui o mapeamento desse locus, após a inserção transposicional, que além de facilitar o seqüenciamento de nucleotÃdeos de grandes fragmentos de DNA, permite uma rápida identificação do gene relacionado com esse fenótipo. Experimentos posteriores revelaram neste locus a presença do gene de uma GlicoproteÃna-P de membrana, cujo papel no metabolismo na Leishmania está sendo analisado
Injecção intralesional de betametasona nas estenoses benignas do esófago
Intralesional steroid injection has been used in benign oesophageal strictures to improve the results of dilatation. Most studies use triamcinolone, only a few have reported using betamethasone.
Objectives: To evaluate the efficacy and safety of the combination of dilatation and intralesional betamethasone injection in benign oesophageal strictures.
Methods: Cases of benign oesophageal strictures treated with dilatation and betamethasone injection between January 1st 1998 and December 31st 2004 were retrospectively analysed. Thirty-one patients (21 males, 10 females) were identified, with a mean age of 58.8 years. The most frequent aetiologies of the stenosis were post-surgical (16 patients), peptic (11 cases) and caustic (5 cases).
Results: The periodic dilatation index significantly decreased (p=0.002), although there was no statistically significant variation between medium luminal diameter pre and post-treatment. There were no adverse events.
Conclusion: Intralesional betamethasone injection is a safe technique which increases efficacy of endoscopic dilatation. However, no conclusions can be drawn from our study due to the small population studied
Avaliação e Promoção da Saúde Psicossocial no Trabalho: Sistemas Integrados de Gestão/ Assessement and promotion of psychosocial health at work: Integrated management systems
A exposição a fatores de risco psicossocial em ambientes laborais é cada vez mais
experienciada pelos trabalhadores, face à pressão em responder à s exigências laborais, aos recursos pessoais disponÃveis e ao contexto global vivenciado e em constante mutação. Tornando urgente o diagnóstico e intervenção psicossocial, de forma sistémica, sistemática e fundamentada, por forma à promoção de ambientes de trabalho saudáveis, inclusivos e sustentáveis. A utilização de metodologias de gestão de riscos psicossociais que possam ser integradas nas práticas torna-se uma mais-valia quer para as organizações quer para os trabalhadores, potenciando as intervenções e o seu impacto. A utilização de referenciais normativos internacionais permite a fundamentação e o desenho de sistemas de gestão de riscos psicossociais de forma integrada e alinhada com os sistemas de gestão. Permitindo o recurso a um léxico conhecido, aliado a uma abordagem já testada e implementadas noutras áreas, como sejam a gestão da qualidade (ISO 9001; ISO 17025) ou a gestão de sistemas integrados de saúde e segurança (ISO 45001, ISO 45003). O presente trabalho tem como principal objetivo a apresentação, sistematização e discussão de uma metodologia de gestão, avaliação e promoção da saúde no trabalho baseado na gestão de riscos psicossociais alicerçado na prática e em modelos de gestão baseados em referenciais normativos
Sistema radicular de bananeira irrigada por aspersão convencional em duas fases fenológicas.
A informação da distância e profundidade das zonas de atuação do sistema radicular permite definir a área na superfÃcie do solo onde deve ser feita a adubação de modo que o fertilizante aplicado seja eficientemente utilizado pela cultura. De acordo com Santos et al. (2005), o conhecimento da área onde ocorre a maior atividade do sistema radicular das culturas é importante para estudos de fornecimento de nutrientes via solo, uma vez que a absorção de água e de nutrientes ocorre simultaneamente. As raÃzes finas têm curto perÃodo de vida (menos que um ano) e são as principais responsáveis pela absorção de água e nutrientes pelas plantas (RYLTER, 1997). No atual estado da arte, nota-se que há poucos estudos referentes ao sistema radicular correlacionado com as fases fenológicas da cultura. O presente estudo teve como objetivo avaliar a distribuição do sistema radicular da bananeira cv. Prata Anã irrigada por aspersão convencional em duas fases fenológicas.pdf 207
Melatonin bioengineered: A New Possible Strategy for Treatment of Breast Cancer
Breast cancer is an important public health problem, with an estimated 3.2 million new cases by the year 2050. Diet plays a key role in the etiology of breast cancer and breastfeeding is associated with a lower incidence of breast cancer. On the other hand, the improvement of the therapeutic properties of bioactive compounds through their incorporation into microcarriers is an important strategy in obtaining new therapies, since cyclical changes in concentration are eliminated; there is biological availability of the compound as well as the reduction in toxicity, number dose and suppression of adverse reactions. Studies using hormones such as melatonin extracted from human milk adsorbed onto polyethylene glycol (PEG) microspheres showed that the controlled release of this compound was able to reduce viability and induce apoptosis in MCF-7 cell lines. Colostrum differs from most of the secretions because it contains viable leukocytes during the first days of lactation with a quantity and activity comparable to blood leukocytes, and has several defense components such as antibodies and hormones, such as melatonin (MLT). This review details the influence of the soluble and cellular components present in human colostrum, such as the MLT hormone, as the modified release systems influence the action of MLT and the possible mechanisms involved that contribute to the hypothesis of reduction of breast cancer in women who breastfed
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