Role of coronary artery spasm in symptomatic and silent myocardial ischemia

The revival of the concept of coronary spasm has stimulated research into coronary artery disease. Observations in patients with variant angina have substantially contributed to the appreciation of painless myocardial ischemia. However, the presence or absence of pain during ischemic episodes is not related to the cause of ischemia, because painless ischemia can be observed in variant angina (caused by spasm), in effort-induced angina (caused by increased myocardial demand) and in myocardial infarction (caused by thrombosis).Continuous monitoring initially of patients with variant angina and subsequently of patients with unstable and stable angina proved that often painful and painless ischemic episodes are caused by a transient impairment of regional coronary blood flow rather than by an excessive increase of myocardial demand. The transient impairment of coronary flow appears to be caused by dynamic stenosis of epicardial coronary arteries. This most often occurs at the site of atherosclerotic plaques encroaching on the lumen to a variable extent.Dynamic stenosis can be caused by 1) “physiologic” increase of coronary tone, as in stable angina, 2) spasm, as in variant angina, and 3) thrombosis, usually in combination with “physiologic” changes in tone or with spasm, or both, as in unstable angina. The mechanisms of spasm, as typically observed in variant angina, are different from those of “physiologic” increase of tone; they appear to be related to a local alteration that makes a segment of coronary artery hyperreactive to a variety of constrictor stimuli causing only minor degrees of constriction in other coronary arteries. The nature of this abnormality, which may remain stable for months and years, is yet unknown

Clinical and experimental evidences on the prothrombotic properties of neutrophils

Epidemiologic studies have shown that the neutrophil count correlates with the risk of myocardial infarction and stroke and identify patients more susceptible to reinfarction and in-hospital death. In particular, neutrophils action was initially associated to blood rheological changes, or to the effect of neutrophil-derived eicosanoids or proteases. Animal models indicate that platelet-leukocyte P-selectin dependent cross-talk contributes to fibrin deposition during in vivo thrombus formation. In fact, platelet P-selectin, through its leukocyte counter-receptor PSGL-1, determines the activation of leukocyte ?2 integrins, the binding of fibrinogen and the expression of tissue factor on leukocyte surface. Monocytes stimulated in vitro with LPS, PMA and P-selectin synthesize and express tissue factor. fMLP, P-selectin, TNFalpha and C5a are effective stimuli that trigger the synthesis and expression of biologically active tissue factor in neutrophils. The experimental evidence well agrees with clinical observations: patients with acute coronary syndromes, acute respiratory distress syndrome, antiphospholipid syndromes, giant cell arteritis and myeloproliferative syndromes have increased the expression of tissue factor on leukocyte surface. Moreover circulating neutrophils express mRNA codifying for fulllength and/or alternatively spliced tissue factor, suggesting a new important link between thrombosis and inflammation. All together, clinical and experimental evidence suggest that the leukocyte thrombogenic profile is a relevant player in patients with a high risk of thromboembolic events and possibly represents a suitable target for molecular intervention

Kajian Mengenai Kesatuan Idea Dalam Dialog Pengajaran Dan Pembelajaran Bidang Estetik Dalam Mata Pelajaran Bahasa Melayu Tingkatan Empat Di Beberapa Buah Sekolah Di Sabah [LB1577.M2 S245 2005 f rb] [) Microfiche 8574].

Pengajaran dan pembelajaran Bahasa Melayu telah begitu lama menggunakan bahan sastera untuk mencapai matlamat dan objektif estetik dalam pendidikan Bahasa Melayu. It has been ages that literature is used in the teaching and learning of Bahasa Melayu to achieve the aesthetic goal and objective of the Bahasa Melayu education

Immune system activation follows inflammation in unstable angina: pathogenetic implications

AbstractObjectives. The aim of this study was to assess the relations between inflammation, specific immune response and clinical course in unstable angina (UA).Background. Several studies suggest that either inflammation and/or T-cell activation might have a pathogenetic role in UA, but neither their potential reciprocal connection nor their relation to the clinical course is known.Methods. Serum levels of C-reactive protein (CRP) (inflammation), IgG, IgA, IgM, C3, C4 (humoral immunity), IL-2 and the percentage of CD4+, CD8+ and CD3+/DR+ T-cells (cell-mediated immunity) were measured in 35 patients with UA and 35 patients with chronic stable angina (CSA) during a period of 6 months.Results. The CRP levels and the main specific immune markers (CD4+ and CD3+/DR+ cells, IL-2 and IgM) were higher in unstable than in stable angina. In UA, the serum levels of IgM and IL-2 and the percentage of double positive CD3+/DR+ significantly increased at 7 to 15 days, and returned to baseline at 6 months. The increment of circulating activated T cells (CD3+/DR+) in UA was inversely related to the admission levels of CRP (r = −0.63, p = 0.003) and associated with a better outcome.Conclusions. Our data suggest that the inflammatory component systemically detectable in UA may be antigen-related and that the magnitude of the immune response correlates with the clinical outcome of instability

Impairment of myocardial perfusion and function during painless myocardial ischemia

Left ventricular (or pulmonary and systemic arterial) hemodynamics were measured for a mean of 13.6 hours during continuous electrocardiographic monitoring in 14 patients admitted to the coronary care unit because of angina at rest. Of 293 episodes of transient ST segment and T wave changes identified, 247 (84%) were completely asymptomatic. Sixty-three percent of asymptomatic episodes were associated with an elevation of the left ventricular end-diastolic or pulmonary artery diastolic pressure of 5 mm Hg or more; in 15% there were smaller elevations (2 to 4 mm Hg) and in 22% there were no changes or less than a 2 mm Hg elevation of pressure. The peak contraction and relaxation dP/dt (first deriviative of left ventricular pressure) were reduced to 100 mm Hg/s or more in 84 and 81 % of asymptomatic episodes, respectively. Great cardiac vein oxygen saturation measured in three patients showed an increased myocardial oxygen extraction similar to that seen in painful episodes, which preceded and accompanied asymptomatic electrocardiographic changes. These results indicate that asymptomatic electrocardiographic changes represent transient myocardial ischemia.Comparison of asymptomatic and symptomatic episodes revealed that asymptomatic episodes were generally shorter (253 ± 159 versus 674 ± 396 seconds, probability [p] < 0.001) and produced less impairment of left ventricular function: there were smaller elevations of left ventricular end-diastolic or pulmonary artery diastolic pressure (5.9 ± 5.0 versus 16.5 ± 6.9 mm Hg, p < 0.001), and smaller reductions of peak left ventricular contraction dP/dt (252 ± 156 versus 395 ± 199 mm Hg/s, p < 0.001) and relaxation dP/dt (259 ± 191 versus 413 ± 209 mm Hg/s, p < 0.001). In individual patients, however, asymptomatic and symptomatic episodes of similar duration and severity were observed. The duration and severity of ischemia appear important for the genesis of anginal pain, but additional factors must be involved

Predefined Object Reduction

Reduction techniques is still an open area to be explored in knowledge management. This paper defines algorithm known as Predefined Hybrid Reduction which generate its conditions for object co occurrences of original data then execute Hybrid Reduction data for their data to perform extractions. Predefined Hybrid Reduction give a proper solution for expansion the data set , it select significant object with high quality of informations, it delete every object not satisfies their conditions. It show appropriate relevant result. It provide better reduction without inconsistency problem unlike data comparisons. It manage the inferior object which store only significant data based on predefined confidence and predefined support for maintain the inferior object then Hybrid reduction which are dual reduction. As part of this proposal, a comparison test with Hybrid reduction. The conclusion part which shows better alternative result through our mode

Malay Language Speech Recognition for Preschool Children using Hidden Markov Model (HMM) System Training

This paper aims to discuss the implementation of Malay Language Speech Recognition (SR) using Hidden Markov Model (HMM) system training for Malay preschool children. The system is developed by implementing the architecture of HMM-based Recognizer with different feature extraction algorithm. The system is trained for 16 Malay words by collecting 704 speech samples (640 for training samples and 64 for testing samples). Data is collected from 20 preschool children aged between five to six years old in real time environments. The paper also describes the process flow to develop the architecture of the system. The experimental results show that the highest overall system performance is 94.86% - Train and 76.04% - Testing which is using MFCC (Mel-Frequency Cepstral Coefficient) with 39 extracted feature vectors (MFCC39)

Vacunación en niños con enfermedades crónicas.

La vacunación es una de las medidas de salud más útiles que existe; permitiendo erradicar enfermedades infecciosas que afectan a la población infantil y provocan gran morbilidad, mortalidad y secuelas. Por otro lado, en las últimas décadas, estamos asistiendo a un aumento de los pacientes con enfermedades crónicas; precisando, la mayoría de ellos, una adaptación específica del calendario de vacunación. Por lo tanto, puede ocurrir que el paciente pediátrico afecto de una enfermedad crónica, pueda encontrarse en un estado de infravacunación; por lo que la optimización del calendario de vacunación en estos niños, se convierte en un aspecto prioritario para cualquier pediatra. OBJETIVOS: Analizar la situación de vacunación en el paciente pediátrico con una enfermedad crónica; tanto de las vacunas sistemáticas oficiales, como aquellas vacunas recomendadas y también las indicadas sólo para determinados grupos de riesgo. Además, como objetivo secundario, se pretende establecer la caracterización del paciente pediátrico afecto de una enfermedad crónica; así como definir los factores de riesgo que conllevan a una situación de infravacunación en el paciente pediátrico con una enfermedad crónica. MATERIAL Y MÉTODO: Estudio retrospectivo longitudinal observacional descriptivo y analítico; en una muestra de pacientes pediátricos afectos con una enfermedad crónica de las de mayor prevalencia, del Hospital Materno Infantil; durante el año 2011. Criterios de inclusión: niños ≥ 1 día y ≤ 14 años, con una enfermedad considerada como crónica, en seguimiento en alguna de las consultas externas más frecuentadas por estos pacientes. Criterios de exclusión: pacientes de origen no español; enfermedad oncológica maligna; una inmunodeficiencia innata o pacientes con pronóstico vital estimado < 6 meses. Variables principales: estado de vacunación sistemática, estado de vacunación frente a neumococo, estado de vacunación frente a varicela, estado de vacunación frente a gripe, estado de vacunación frente a hepatitis A y estado global de vacunación del paciente. Variables secundarias: variables demográficas propias del paciente y de su enfermedad de base. Análisis estadístico: En un primer momento se llevó a cabo el análisis descriptivo. Para las variables cualitativas se determinaron las distribuciones de frecuencia; y para las variables cuantitativas, una medida de tendencia central y una de dispersión. En el análisis univariante se realizaron contrastes de hipótesis con tablas de contingencia y test ji cuadrado para estudiar las variables cualitativas. Para las variables cuantitativas se utilizaron técnicas paramétricas T Student o análisis de la varianza de una vía (ANOVA), o técnicas no paramétricas, Test de Mann Withney o Kruskal Wallis. Como técnica multivariante se realizó un análisis, utilizando las técnicas de árboles de decisión procedimiento CHAID (CHi-squared Automatic Interaction Detection – Detector Automático de Interacción Chi-cuadrado) para los árboles de clasificación. RESULTADOS: desde el uno de enero hasta el 31 de diciembre de 2011, se reclutaron un total de 140 pacientes afectos de una enfermedad crónica; elegidos al azar, cumpliendo todos los criterios de inclusión y ninguno de exclusión. La edad media fue de 6,7 años, con un ligero predomino de sexo femenino (54,3%). El 86,4% de los pacientes no tenía antecedentes de prematuridad; sólo el 5,7% había presentado desnutrición; y el 14,3% de los pacientes se encontraba en tratamiento con corticoides y/o fármacos inmunosupresores. El 24,3% había sido sometido a alguna intervención quirúrgica; y el 67,9% de los casos había precisado ingreso hospitalario, debido a su enfermedad de base. En cuanto al análisis del estado de vacunación global del paciente, el 20% de los casos poseía un estado correcto de vacunación; el 17,9% de los pacientes se encontraba vacunado, pero de manera incompleta debido a ausencia o retraso de alguna dosis; y finalmente, el 62,1% de los casos se encontraban incorrectamente vacunados debido a la ausencia de la vacunación recomendada; a la vacunación propia de los grupos de riesgo; o ausencia de ambas. CONCLUSIONES: nuestros datos sugieren que el 80% de los pacientes presenta alguna deficiencia en su estado de vacunación; por lo que asegurar un correcto estado de inmunización en estos pacientes, se convierte en un objetivo prioritario. La edad del paciente, la prematuridad y el tratamiento con corticoides y/o inmunosupresores, suponen un factor de riesgo para el estado de vacunación. El nivel económico y educativo de los progenitores, parece ser un factor determinante en la vacunación recomendada (neumococo y varicela). El principal motivo de una vacunación incorrecta en el paciente pediátrico afecto de una enfermedad crónica es; su propia enfermedad de base, y, en segundo lugar, el desconocimiento por parte de los progenitores