La norma IEEE 802.6 (DQDB) operando en tiempo real duro

En trabajos previo se ha demostrado que la norma IEEE 802.6 (DQDB) no puede, implementar las disciplinas de Rueda Cíclica Justa o de Periodos Monotónicos Crecientes, salvo que se introduzcan modificaciones tan sustanciales que resulten no implementables con los mecanismos normalizados. El objeto del presente trabajo es analizar las condiciones de diagramabilidad de la red sin alterar sus protocolos de acceso al medio. Se encuentra una expresión para el periodo mínimo de los mensajes de cada nodo en función de la longitus del mensaje, de su distancia al extremo generador de ranuras, del número de nodos aguas arriba y de la función trabajo de los no'dos aguas abajo.Eje: Redes de computadorasRed de Universidades con Carreras en Informática (RedUNCI

Comunicaciones multimediales en entornos médicos

DICOM es una especificación desarrollada con la intención de normalizar la forma en que se adquieren, codifican, transmiten e interpretan las imágenes médicas y la información adjunta. La norma está definida al nivel de aplicación, y permite cualquier red de interconexión compatible con el modelo de referencia ISO/OSI ó TCP/IP. DICOM fue originalmente diseñada para la transmisión y almacenamiento de imágenes médicas. La norma provee los mecanismos necesarios para implementar en forma natural la transmisión y almacenamiento de imágenes comprimidas por el formato JPEG. Sin embargo, en la norma no se especifican mecanismos similares para la transmisión de video. Existe un gran número de aplicaciones de la medicina que emplean videos, debido a lo cual resulta atractiva la posibilidad de utilizar DICOM para la transmisión de videos médicos. En este trabajo se propone la adaptación de la norma para la transmision de videos médicos en tiempo real a partir de la compresión y transmisión en forma individual de cada uno de los cuadros que conforman la secuencia. Para ello se requiere la operación en tiempo real tanto de la computadora en donde se realice el procesamiento de la imágen como de la red sobre la que se transmitan. La operación en tiempo real implica no sólo el correcto comportamiento desde el punto de vista funcional sino que además debe ser realizado antes de un determinado instante que se denomina vencimiento. El análisis se realizará exclusivamente desde el punto de vista de la diagramabilidad de la red, es decir, su capacidad para transmitir todos los mensajes en término. En particular se plantea la factibilidad de la utilización de una red FDDI (Fibre Distributed Data Interface) como soporte para implementar aplicaciones DICOM. Se analizan sus ventajas y desventajas, considerando los requerimientos de DICOM y las características de FDDI desde los puntos de vista de ancho de banda, retardo máximo y variación del tiempo de inter-arribo de los mensajes. Ninguno de estos factores está contemplado por DICOM.Sistemas Distribuidos - Redes Concurrencia - Sesión de póstersRed de Universidades con Carreras en Informática (RedUNCI

La norma IEEE 802.6 (DQDB) operando en tiempo real duro

En trabajos previo se ha demostrado que la norma IEEE 802.6 (DQDB) no puede, implementar las disciplinas de Rueda Cíclica Justa o de Periodos Monotónicos Crecientes, salvo que se introduzcan modificaciones tan sustanciales que resulten no implementables con los mecanismos normalizados. El objeto del presente trabajo es analizar las condiciones de diagramabilidad de la red sin alterar sus protocolos de acceso al medio. Se encuentra una expresión para el periodo mínimo de los mensajes de cada nodo en función de la longitus del mensaje, de su distancia al extremo generador de ranuras, del número de nodos aguas arriba y de la función trabajo de los no'dos aguas abajo.Eje: Redes de computadorasRed de Universidades con Carreras en Informática (RedUNCI

Laboratory diagnosis of severe hypertriglyceridaemia. Cases from the dyslipidaemia regristy of the spanish atherosclerosis society

Background and Aims Severe hypertriglyceridaemia (sHTG) increases the risk of cardiovascular disease and acute pancreatitis episodes. Patients with sHTG fit mainly into two clinical entities: Familial or Multifactorial Chylomicronemia Syndromes (FCS and MCS, respectively). FCS and MCS exhibit clinical differences but also separate genetic and biochemical characteristics that can be assessed in the laboratory. The aim of this work has been to implement a laboratory workflow to help diagnose sHTG patients with either FCS or MCS. Methods Patients with two fasting triglycerides >1000mg/dL determinations were sequenced with a capture probe panel of 24 triglycerides-related genes using massive parallel sequencing (n=200). Two-step sequential ultracentrifugation was performed (n= 159) to diagnose Type I hyperlipoproteinemia (HLP I) and post heparin lipoprotein lipase activity was measured to discard or confirm its deficiency (n=60). Results Most patients had MCS as they: (i) did not exhibit HLPI and/or (ii) their genetic profile was not compatible with FCS and (iii) were not deficient in LPL activity. FCS cases were identified as they had: (i) HLPI, and/or (ii) biallelic pathogenic variants in LPL (n=5), GPIHBP1 (n=3), or LMF1 (n=2) genes and/or (iii) LPL activity deficiency. We identified 4 FCS patients with HLPI, biallelic pathogenic variants in APOA5 but a rescued LPL activity. An additional study of Apo-AV functionality was designed to confirm the FCS diagnosis in these cases. Conclusions Laboratory studies, in patients with severe hypertriglyceridaemia, provide with information of clinical utility to distinguish between Familial and Multifactorial Chylomicronemia Syndromes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Long-term effect of 2 intensive statin regimens on treatment and incidence of cardiovascular events in familial hypercholesterolemia : The SAFEHEART study

Funding: This study was supported by Fundación Hipercolesterolemia Familiar; Grant G03/181 Grant 08-2008 Centro Nacional de Investigaci?n Cardiovascular (CNIC).Background: Maximal doses of potent statins are the basement of treatment of familial hypercholesterolemia (FH). Little is known about the use of different statin regimens in FH. Objectives: The objectives of the study were to describe the treatment changes and low-density lipoprotein cholesterol (LDL-C) goal achievement with atorvastatin (ATV) and rosuvastatin (RV) in the SAFEHEART cohort, as well as to analyze the incidence of atherosclerotic cardiovascular events (ACVEs) and changes in the cardiovascular risk. Methods: SAFEHEART is a prospective follow-up nationwide cohort study in a molecularly defined FH population. The patients were contacted on a yearly basis to obtain relevant changes in life habits, medication, and ACVEs. Results: A total of 1939 patients were analyzed. Median follow-up was 6.6 years (5-10). The estimated 10-year risk according the SAFEHEART risk equation was 1.61 (0.67-3.39) and 1.22 (0.54-2.93) at enrollment for ATV and RV, respectively (P <.001). There were no significant differences at the follow-up: 1.29 (0.54-2.82) and 1.22 (0.54-2.76) in the ATV and RV groups, respectively (P =.51). Sixteen percent of patients in primary prevention with ATV and 18% with RV achieved an LDL-C <100 mg/dL and 4% in secondary prevention with ATV and 5% with RV achieved an LDL-C <70 mg/dL. The use of ezetimibe was marginally greater in the RV group. One hundred sixty ACVEs occurred during follow-up, being its incidence rate 1.1 events/100 patient-years in the ATV group and 1.2 in the RV group (P =.58). Conclusion: ATV and RV are 2 high-potency statins widely used in FH. Although the reduction in LDL-C levels was greater with RV than with ATV, the superiority of RV for reducing ACVEs was not demonstrated

Atorvastatin versus Bezafibrate in Mixed Hyperlipidaemia : Randomised Clinical Trial of Efficacy and Safety (the ATOMIX Study)

OBJECTIVE: Combined hyperlipidaemia is a common and highly atherogenic lipid phenotype with multiple lipoprotein abnormalities that are difficult to normalise with single-drug therapy. The ATOMIX multicentre, controlled clinical trial compared the efficacy and safety of atorvastatin and bezafibrate in patients with diet-resistant combined hyperlipidaemia. PATIENTS AND STUDY DESIGN: Following a 6-week placebo run-in period, 138 patients received atorvastatin 10mg or bezafibrate 400mg once daily in a randomised, double-blind, placebo-controlled trial. To meet predefined low-density lipoprotein-cholesterol (LDL-C) target levels, atorvastatin dosages were increased to 20mg or 40mg once daily after 8 and 16 weeks, respectively. RESULTS: After 52 weeks, atorvastatin achieved greater reductions in LDL-C than bezafibrate (percentage decrease 35 vs 5; p < 0.0001), while bezafibrate achieved greater reductions in triglyceride than atorvastatin (percentage decrease 33 vs 21; p < 0.05) and greater increases in high-density lipoprotein-cholesterol (HDL-C) [percentage increase 28 vs 17; p < 0.01 ]. Target LDL-C levels (according to global risk) were attained in 62% of atorvastatin recipients and 6% of bezafibrate recipients, and triglyceride levels <200 mg/dL were achieved in 52% and 60% of patients, respectively. In patients with normal baseline HDL-C, bezafibrate was superior to atorvastatin for raising HDL-C, while in those with baseline HDL-C <35 mg/dL, the two drugs raised HDL-C to a similar extent after adjustment for baseline values. Both drugs were well tolerated. CONCLUSION: The results show that atorvastatin has an overall better efficacy than bezafibrate in concomitantly reaching LDL-C and triglyceride target levels in combined hyperlipidaemia, thus supporting its use as monotherapy in patients with this lipid phenotype

A resilient type of familial hypercholesterolaemia: case-control follow-up of genetically characterized older patients in the SAFEHEART cohort.

Knowledge of the features of patients with familial hypercholesterolaemia (FH) who are protected from atherosclerotic cardiovascular disease (ASCVD) is important for the clinical and prognostic care of this apparently high-risk condition. Our aim was to investigate the determinant and characteristics of patients with FH who are protected from ASCVD and have normal life expectancy, so-called 'resilient' FH (R-FH). Spanish Familial Hypercholesterolaemia cohort study (SAFEHEART) is an open, multicentre, nation-wide, long-term prospective cohort study in genetically defined patients with heterozygous FH in Spain. Patients in the registry who at the time of analysis were at least 65 years or those who would have reached that age had they not died from an ASCVD event were analysed as a case-control study. Resilient FH was defined as the presence of a pathogenic mutation causative of FH in a patient aged ≥65 years without clinical ASCVD. Nine hundred and thirty registrants with FH met the study criteria. A defective low-density lipoprotein (LDL)-receptor mutation, higher plasma level of high-density lipoprotein cholesterol (HDL-C), younger age, female gender, absence of hypertension, and lower plasma lipoprotein (a) [Lp(a)] concentration were independently predictive of R-FH. In a second model, higher levels of HDL-C and lower 10-year score in SAFEHEART-RE were also independently predictive of R-FH. Resilient FH may be typified as being female and having a defective LDL-receptor mutation, higher levels of plasma HDL-C, lower levels of Lp(a), and an absence of hypertension. The implications of this type of FH for clinical practice guidelines and the value for service design and optional care of FH remains to be established. ClinicalTrials.gov number NCT02693548