Predictors of restenosis following unprotected left main coronary stenting.
Explore the source record for details and available documents.
Coronary Angiography↗
Biomedical subjects
A Medina
Publications and source records attributed to A Medina.
Clinical implications for affected parents and siblings of probands with long-QT syndrome.
BACKGROUND: Whenever a proband is identified with long-QT syndrome (LQTS), his or her parents and siblings should be evaluated regarding the possibility of carrying the disorder. In the majority of cases, one of the proband's parents and one or more siblings are affected. The aim of this study was (1) to determine whether the clinical severity of LQTS in the proband is useful in identifying first-degree family members at high risk for cardiac events, and (2) to evaluate the clinical course of affected parents and siblings of LQTS probands. METHODS AND RESULTS: The clinical and ECG characteristics of 211 LQTS probands and 791 first-degree relatives (422 parents and 369 siblings) were studied to determine if the clinical profile of the proband is useful in determining the clinical severity of LQTS in affected parents and siblings. Affected female parents of an LQTS proband had a greater cumulative risk for a first cardiac event than affected male parents. The probability of a parent or sibling having a first cardiac event was not significantly influenced by the severity of the proband's clinical symptoms. Female sex and QT(c) duration were risk factors for cardiac events among affected parents, and QT(c) was the only risk factor for cardiac events in affected siblings. CONCLUSIONS: The severity profile of LQTS in a proband was not found to be useful in identifying the clinical severity of LQTS in affected first-degree relatives of the proband.
Adolescent↗
Unified optimization criterion for energy converters.
We propose a unified optimization criterion for energy converters. It represents the best compromise between energy benefits and losses for a specific job and neither an explicit evaluation of entropies nor the consideration of environmental parameters are required. For all considered systems the criterion predicts a performance regime laying between those of maximum efficiency and maximum useful energy. Such regime has been invoked as optimum not only in macroscopic heat engines but also in some molecular motors.
Journal Article↗
Comparison of procalcitonin with C-reactive protein and serum amyloid for the early diagnosis of bacterial sepsis in critically ill neonates and children.
OBJECTIVES: To evaluate procalcitonin (PCT) as a diagnostic marker of bacterial sepsis in critically ill neonates and children and to compare the results of PCT with those of C-reactive protein (CRP) and serum amyloid (SAA). DESIGN AND SETTING: Prospective, observational study in neonatal and pediatric intensive care units. PATIENTS: A total of 116 divided into four groups according to age and diagnosis: neonates (aged 3-30 days) with sepsis (n = 20), neonates without sepsis (n = 26), children (aged 2-12 years) with sepsis (n = 32), and children without sepsis (n = 38). INTERVENTIONS: Serum PCT, CRP, and SAA were measured on admission or when a bacterial sepsis was suspected. Area under the receiver operating characteristic (ROC) curve, optimum predictive values, and optimum diagnostic cut off values were evaluated. RESULTS: Admission PCT was significantly higher in neonates and children with sepsis than in the other groups. In the neonates the area under the ROC curve was 0.99 for PCT, 0.95 for CRP, and 0.98 for SAA; in the children it was 1 for PCT, 0.93 for CRP, and 0.96 for SAA. Cutoff concentrations for optimum prediction of sepsis in the neonates were PCT > 6.1 ng/ml (diagnostic efficiency: 93.8%), CRP > 23.0 mg/l (89.7%), and SAA > 41.3 mg/l (95.3%); in the children they were PCT > 8.1 ng/ml (100%), CRP > 22.1 mg/l (89.8%), and SAA > 67.2 mg/l (94.4%). CONCLUSION: In critically ill children PCT concentration is a better diagnostic marker of sepsis than CRP and SAA. In critically ill neonates, however, PCT, CRP, and SAA are similar diagnostic markers of sepsis. A PCT concentration higher than 8.1 ng/ml identified all children with bacterial sepsis.
Amyloid↗
Quality assurance of point-of-care testing in the Costa del Sol Healthcare Area (Marbella, Spain).
Traditionally, point-of-care testing (POCT) has been used throughout the healthcare system without the involvement of the central laboratory. After an exhaustive study of the situation of these laboratories in the Costa del Sol Healthcare Area, we designed a quality control program for the POCT. This program targeted the tests done at the points of care throughout the hospital and the Primary Healthcare Area (PHA), using the Joint Commission on Accreditation of Healthcare Organisations (JCAHO) standards for waived testing. We developed two programs: hospital-based tests and ambulatory POCT for outpatients in PHA. The hospital-based POCT apparatus was used for gases, glucose, qualitative urinalysis, Helicobacter pylori detection in gastrointestinal biopsies and coagulation tests. Ambulatory POCT was used to detect glucose, qualitative urinalysis and pregnancy tests. The personnel responsible are nursing staff with no continuing training program. There was no explicit quality control program and most of the results were used as screening except for glucose in the neonatal department. Criteria for selection of kits and devices were basically based on ergonomic and economic evaluation. Therefore, we performed an evaluation of precision and accuracy of two glucose meter devices. We implemented the internal and external quality programs (IQC and EQC) for glucose testing. We elaborated a guide of standard proceedings for quantitative and qualitative POCT and created an annual course for nursing staff. The annual evaluation of the indicators showed 96% for degree of compliance with IQC; 54% of nursing staff participated in the training program; 98% of the glucometers were operating; and 88% agreement between central laboratory and POCT. As there is no previous experience in our healthcare system, this represents a promising new area of working with nurses, who show great interest in participating in these new programs.
Clinical Chemistry Tests↗
[Non-small cell bronchogenic carcinoma in advanced stages: prognostic value of weight loss and clinical implications].
UNLABELLED: This study of advanced-stage non-small cell bronchogenic carcinoma aimed 1) to identify prognostic factors collected at the moment of diagnosis, 2) to determine whether weight loss is a useful parameter to screen for subjects who will receive greater benefit from anticancer therapy.Patients and methods. Eighty-one patients were enrolled after diagnosis of stage III-B and IV non-small cell bronchogenic carcinoma and levels of activity < 2 according to Eastern Co-operative Oncology Group classification. The variables studied were age, sex, smoking history, associated disease, clinical data (weight loss, dyspnea, superior vena cava syndrome), laboratory parameters [hemoglobin, serum albumin, total lymphocytes, serum lactate dehydrogenase (LDH), calcium and liver enzymes], tumor-node-metastasis (TNM) staging, histologic type, activity, treatment received and survival in weeks. The results were analyzed in two groups: 1) the general group consisting of results for all patients, and 2) the no-weight-loss group consisting of results for those whose weight had been stable. Student t, chi-squared, Kaplan Meier, log-rank and Cox's regression model were used to analyze data and survival. RESULTS: Mean survival was 29 weeks (21-37). Survival was significantly related to weight loss, total lymphocytes, serum LDH, TNM and activity level in the general group. Only two factors continued to have prognostic value in the multivariate study: weight loss (OR: 1.48 (1.14-1.92), p = 0.002) and TNM (OR: 0.72 (0.54-0.96), p = 0.02). Among the patients with no weight loss, treatment received and TNM were significantly related to survival in univariable analysis and in Cox's regression model. CONCLUSIONS: In our experience with advanced lung cancer subjected to anticancer therapy, the presence of weight loss is the variable with the greatest prognostic value, such that it may be useful to consider it routinely, along with activity level, to try to identify patients who will receive the most benefit from cytostatic treatment.
Adult↗
[Cor triatriatum associated with Wolff-Parkinson-White syndrome].
Several anatomic anomalies have been associated with the Wolff-Parkinson-White syndrome. However, its association with cor triatriatum has never been previously established. We present a case report on a 34-year-old woman patient with paroxysmic palpitations and data of ventricular preexcitation seen on electrocardiogram. The presence of non-obstructive cor triatriatum was observed during echocardiographic valoration prior to radiofrequency catheter ablation.
Adult↗
Association of angiotensinogen M235T and A(-6)G gene polymorphisms with coronary heart disease with independence of essential hypertension: the PROCAGENE study. Prospective Cardiac Gene.
OBJECTIVES: We examined the relationship between the angiotensinogen (AGT) gene M235T polymorphism, the variant promoter of the AGT gene A(-6)G and the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and coronary heart disease (CHD) in native Gran Canaria Island habitants, who have the highest rates of CHD in Spain. BACKGROUND: Some studies subject that the ACE (I/D) polymorphism could be associated with CHD, while AGT (M235T) has been related to essential hypertension. METHODS: We studied 304 subjects with angiographic evidence of coronary artery disease and a clinical diagnosis of myocardial infarction or unstable angina and 315 age- and gender-matched controls. Blood was drawn and DNA extracted. Angiotensin-converting enzyme (I/D) gene polymorphism was analyzed by polymerase chain reaction (PCR) and AGT gene polymorphisms by restriction fragment length polymorphism-PCR and mutagenically-separated PCR. RESULTS: The ACE (I/D) polymorphism showed no association with CHD, whereas the frequency distribution of AGT (M235T) genotypes among patients and controls (235T: 29.1% and 19.0%; M235T: 48.5% and 50.2%; M235: 22.4% and 30.8%, respectively) was statistically different (p = 0.005) and not related to the presence of essential hypertension. Similar results were observed with the AGT A(-6)G polymorphism. In multiple logistic regression analysis, CHD odds ratio associated with 235T and M235 homozygotes were 1.7 (1.1 to 2.6) and 0.54 (0.36 to 0.82), respectively. CONCLUSIONS: This study shows that genetic variation of the AGT (M235T), but not the ACE (I/D), genotypes contributes to the presence of CHD independently of blood pressure profile in a subset of the Spanish population with a high prevalence of cardiovascular disease.
Adult↗
Nitrogen budget in Scenedesmus obliquus cultures with artificial wastewater.
Semicontinuous cultures of Scenedesmus obliquus in artificial wastewater, recycled into proteins about 33% and 25% of the dissolved nitrogen missing from the medium 24 h after harvesting 50% and 70% of the culture, and replacing the volume harvested with fresh medium. The residual dissolved nitrogen concentrations were 25% and 43% of the initial, respectively, with an imbalance in the mass budget close to 17 and 20 mg N l(-1) d-1. Most or all the nitrogen missing was found in an ammonia trap located at the air vent of the closed cultures, showing that an important role of microalgae in wastewater treatment is that of favouring NH3 stripping due to the photosynthesis-induced pH increases.
Ammonia↗
Varicella complicated by group A streptococcal facial cellulitis.
An increase has been recently noted in the incidence of life-threatening group A beta-hemolytic streptococcal (GABHS) infections in children recovering from varicella. We report our experience with a patient who required pediatric intensive care unit admission because of a serious GABHS infection 1 week after the onset of varicella. Emergency physicians must look for this complication in patients with varicella remaining abnormally febrile and presenting unusual manifestations.
Amoxicillin↗
Simplified method for the detection of apo(a) isoforms.
Apolipoprotein a, is a high molecular weight glycoproteic component of Lp(a), a molecule associated with coronary arterial disease. Apo(a) exhibits considerable size heterogeneity due to variable repetitions of the carbohydrate-containing structural unit, termed kringle. There are five different kringle forms and 10 different kringle 4 types. Apo(a) polymorphism and molecular weight depend on the number of copies of kringle 4 type 2. In this paper we describe a modified 3.75% and 6% discontinuous polyacrylamide gel system and Western-blot technique that shortness the assay time and improves the identification of apo(a) isoforms with a theoretical error of less than 1 kringle. The assay uses a standard curve prepared with five different recombinant apo(a) molecules, detected up to 50 ng of protein in Lp(a), showed a maximal resolution of 2 kringles and, with the use of third degree polynominal regression analysis, had an error of 0.01275. The inter-assay coefficient of variation was 1.7, 2, and 1.4 for the 14 K, 18 K, and 22 K phenotypes, whereas the intra-assay coefficient of variation was 0.32%, 0.18%, and 0.17%, respectively. It is possible that this modified method will diminish the number of putative null alleles so far detected in various studies, but most of all, we are certain that it can be of use in epidemiological studies due to its ease of use, speed, low cost, and enhanced number of samples that can be tested.
Alleles↗
Functional analysis of the Xenopus frizzled 7 protein domains using chimeric receptors.
Seven-transmembrane receptors of the frizzled family can interact with secreted Wnt ligands and transmit Wnt signals into the cell. Dependent on the ligand receptor combination, distinct Wnt pathways are activated. Xenopus frizzled 7 (Xfz7) and Xwnt-8b as well as Human frizzled 5 (Hfz5) and Xwnt-5a can act synergistically in the activation of Wnt/beta-catenin target genes siamois (Xsia) and nodal related 3 (Xnr3) and in the induction of ectopic axes in Xenopus embryos. In order to characterize the role of different protein domains of Xfz7 in Wnt/beta-catenin signaling, chimeric Xfz7/Hfz5 receptors were generated in which the extracellular (N5-TC7) or the intracellular domains (NT7-C5) between Xfz7 and Hfz5 were exchanged. We present evidence that the extracellular domain of Xfz7 can interact with Xwnt-5a and that the intracellular C-terminus can transmit a Wnt/beta-catenin signal. Despite these abilities, Xfz7 and Xwnt-5a do not act synergistically in the activation of Wnt/beta-catenin targets. This implies that the interaction of a frizzled receptor with different ligands can result in distinct cellular responses.
Animals↗
Spectrum of ST-T-wave patterns and repolarization parameters in congenital long-QT syndrome: ECG findings identify genotypes.
BACKGROUND: Congenital long-QT syndrome (LQTS) is caused by mutations of genes encoding the slow component of the delayed rectifier current (LQT1, LQT5), the rapid component of the delayed rectifier current (LQT2, LQT6), or the Na(+) current (LQT3), resulting in ST-T-wave abnormalities on the ECG. This study evaluated the spectrum of ST-T-wave patterns and repolarization parameters by genotype and determined whether genotype could be identified by ECG. METHODS AND RESULTS: ECGs of 284 gene carriers were studied to determine ST-T-wave patterns, and repolarization parameters were quantified. Genotypes were identified by individual ECG versus family-grouped ECG analysis in separate studies using ECGs of 146 gene carriers from 29 families and 233 members of 127 families undergoing molecular genotyping, respectively. Ten typical ST-T patterns (4 LQT1, 4 LQT2, and 2 LQT3) were present in 88% of LQT1 and LQT2 carriers and in 65% of LQT3 carriers. Repolarization parameters also differed by genotype. A combination of quantified repolarization parameters identified genotype with sensitivity/specificity of 85%/70% for LQT1, 83%/94% for LQT2, and 47%/63% for LQT3. Typical patterns in family-grouped ECGs best identified the genotype, being correct in 56 of 56 (21 LQT1, 33 LQT2, and 2 LQT3) families with mutation results. CONCLUSIONS: Typical ST-T-wave patterns are present in the majority of genotyped LQTS patients and can be used to identify LQT1, LQT2, and possibly LQT3 genotypes. Family-grouped ECG analysis improves genotype identification accuracy. This approach can simplify genetic screening by targeting the gene for initial study. The multiple ST-T patterns in each genotype raise questions regarding the pathophysiology and regulation of repolarization in LQTS.
Adolescent↗
Effects of flecainide in patients with new SCN5A mutation: mutation-specific therapy for long-QT syndrome?
BACKGROUND: Mutations in the cardiac sodium channel gene (SCN5A) can cause one variant of the congenital long-QT syndrome. The effects of some of these mutations on the alpha-subunit channel properties can be blocked by type Ib antiarrhythmic drugs. Recently, we have described a new SCN5A mutation (D1790G) that affects the channel properties in a manner suggesting that sodium blockers of the Ib type will be ineffective in carriers of this mutation. Hence, the ECG effects of flecainide-acetate, a type Ic sodium blocker, were evaluated in carriers of this mutation. METHODS AND RESULTS: Eight asymptomatic mutation carriers and 5 control subjects were studied. Intravenous lidocaine was tested first in only 2 mutation carriers and had no significant effect on any ECG parameter. Flecainide significantly shortened all heart rate-corrected repolarization duration parameters only in carriers and not in control subjects: QT(c) shortened by 9.5% (from 517+/-45 to 468+/-36 ms, P=0.011), and the S-offset to T-onset interval shortened by 64.7% (from 187+/-88 to 66+/-50 ms, P=0.0092). Flecainide also normalized the marked baseline repolarization dispersion in most mutation carriers. These effects among carriers were maintained during long-term (9 to 17 months) outpatient flecainide therapy with no adverse effects. CONCLUSIONS: This report is the first to describe SCN5A mutation carriers who significantly responded to flecainide therapy yet did not respond to lidocaine. These results have important implications for long-QT allele-specific therapeutic strategies.
Anti-Arrhythmia Agents↗
Clinical and genetic variables associated with acute arousal and nonarousal-related cardiac events among subjects with long QT syndrome.
In patients with the long QT syndrome (LQTS), the occurrence of cardiac events (syncope or cardiac arrest) is frequently associated with acute arousal caused by exercise, swimming, emotion, or noise. However, cardiac events may also occur during sleep or with ordinary daily activities. The purpose of this study was to determine whether there are differential clinical, electrocardiographic, and genetic features among LQTS patients who experienced cardiac events with and without acute arousal. We identified 1,325 patients with cardiac events from the International LQTS Registry. Based on the precipitating conditions of the first event, 427 patients were classified as arousal, 345 as nonarousal, and the remaining 553 were unknown (not classifiable). Gene linkage was known in 78 of the 772 patients with classifiable first events. The age at first cardiac event was significantly younger in the arousal than the nonarousal group (11.7 vs. 15.5 years, respectively; p<0.001). The arousal-type patients had a higher rate of subsequent cardiac events during follow-up after the index event than the nonarousal-type patients (p = 0.02). Arousal-related cardiac events occurred in 85% of LQT1, 67% of LQT2, and 33% of LQT3 patients (p = 0.008). This study provides evidence that the genotype is an important determinant of the LQTS phenotype in terms of arousal and nonarousal-related cardiac events.
Acute Disease↗
Effectiveness and limitations of beta-blocker therapy in congenital long-QT syndrome.
BACKGROUND: beta-blockers are routinely prescribed in congenital long-QT syndrome (LQTS), but the effectiveness and limitations of beta-blockers in this disorder have not been evaluated. METHODS AND RESULTS: The study population comprised 869 LQTS patients treated with beta-blockers. Effectiveness of beta-blockers was analyzed during matched periods before and after starting beta-blocker therapy, and by survivorship methods to determine factors associated with cardiac events while on prescribed beta-blockers. After initiation of beta-blockers, there was a significant (P<0.001) reduction in the rate of cardiac events in probands (0.97+/-1.42 to 0.31+/-0.86 events per year) and in affected family members (0. 26+/-0.84 to 0.15+/-0.69 events per year) during 5-year matched periods. On-therapy survivorship analyses revealed that patients with cardiac symptoms before beta-blockers (n=598) had a hazard ratio of 5.8 (95% CI, 3.7 to 9.1) for recurrent cardiac events (syncope, aborted cardiac arrest, or death) during beta-blocker therapy compared with asymptomatic patients; 32% of these symptomatic patients will have another cardiac event within 5 years while on prescribed beta-blockers. Patients with a history of aborted cardiac arrest before starting beta-blockers (n=113) had a hazard ratio of 12.9 (95% CI, 4.7 to 35.5) for aborted cardiac arrest or death while on prescribed beta-blockers compared with asymptomatic patients; 14% of these patients will have another arrest (aborted or fatal) within 5 years on beta-blockers. CONCLUSIONS: beta-blockers are associated with a significant reduction in cardiac events in LQTS patients. However, syncope, aborted cardiac arrest, and LQTS-related death continue to occur while patients are on prescribed beta-blockers, particularly in those who were symptomatic before starting this therapy.
Adolescent↗
Quantification of the age-pigment lipofuscin in brains of known-age, pond-reared prawns Penaeus japonicus (Crustacea, decapoda).
A quantitative study of the lipofuscin content was carried out by image analysis in brains of known-age, pond-reared Penaeus japonicus (Crustacea, Decapoda) with the aim of assessing the applicability of the lipofuscin technique as an estimator of the physiological age in penaeids. With this purpose, three distinct measurements of lipofuscin levels (% area fraction, granule density and mean granule size) were recorded in ten sections of the olfactory lobe cell mass (OLCM) per animal. The image analysis was based on the autofluorescence emitted by the pigment, which accentuates the contrast between the lipofuscin granules and the background tissue. The concentration of lipofuscin increased significantly with age and was independent of sex. The relationship between age and lipofuscin concentration (area fraction and granule density) was best described by a seasonalized von Bertalanffy function, since the accumulation rate of the pigment dramatically slowed down in fall-winter, probably as a result of reduced seasonal metabolism. The present results confirm the potential of the lipofuscin method in the estimation of physiological age in penaeids and suggest that the application of this methodology can be useful in studies of age structure in wild populations and in the assessment of natural resources. J. Exp. Zool. 286:120-130, 2000.
Animals↗
Interaction of Frizzled 7 and Dishevelled in Xenopus.
Frizzled proteins act as putative Wnt receptors and depending on Wnt/Frizzled interactions distinct intracellular pathways can be activated. The canonical Wnt pathway, triggered by Wnt-1-type ligands, is the best characterized and involves the activation of the cytoplasmic protein Dishevelled (Dsh). The Xenopus frizzled 7 receptor (Xfz7) can act in the canonical (Wnt-1-type) as well as in a non-canonical Wnt pathway which involves the activation of protein kinase C (PKC). In order to analyze the interaction between Xfz7 and Xdsh protein, we tested the effect of overexpression of Xfz7 on the subcellular distribution of Xdsh-myc protein. We demonstrate that Xfz7 can recruit Xdsh-myc to the plasma membrane and target genes of the Wnt-1-type pathway such as siamois and nodal related 3 (Xnr-3) are only activated in the presence of exogenous Xdsh-myc. Xfz7 in combination with Xwnt-8b, however, is able to induce siamois even in the absence of Xdsh-myc. Similar results were obtained after expression of Human frizzled 5 (Hfz5) together with Xwnt-5a but this receptor-ligand combination recruits Xdsh-myc only very poorly to the membrane. These results suggests that the endogenous Xdsh pool and exogenous Xdsh-myc differ in their ability to be recruited by Frizzled receptors.
Adaptor Proteins, Signal Transducing↗