RESUMEN
BACKGROUND: Chronic Kidney Disease (CKD) is a prevalent and life-threatening situation recognized as an emerging health issue. The present study aimed to evaluate the effect of demographic and laboratory parameters on the survival of patients with End-Stage Renal Disease (ESRD) in a hemodialysis (HD) center in Iran. MATERIALS AND METHODS: This study was conducted on patients receiving chronic HD in Iran Helal Pharmaceutical and Clinical Complex between 2014 and 2018. The survival time was considered as the time interval between HD initiation and death. Receiving kidney transplantation was regarded as a competing risk, and an improper form of two-parameter Weibull distribution was utilized to simultaneously model the time to both death and renal transplantation. The Bayesian approach was conducted for parameters estimation. RESULTS: Overall, 29 (26.6%) patients expired, and 19 (17.4%) received kidney transplants. The male gender was related to poor survival, having nearly 4.6 folds higher hazard of mortality (90% HPD region: 1.36-15.49). Moreover, Serum calcium levels [Formula: see text]9.5 mg/dL (adjusted Sub-hazard ratio (S-HR)=2.33, 90% HPD region: 1.05-5.32) and intact parathyroid hormone (iPTH) [Formula: see text]150 pg/mL (adjusted S-HR = 2.56, 90% HPD region: 1.09-6.15) were associated with an elevated hazard of mortality. The cumulative incidence function (CIF) for transplantation was greater than death in the first two years of the study. Subsequently, the CIF for death exceeded transplantation in the following two years. The 4-year cumulative incidence of death and kidney transplantation was 63.7% and 36.3%, respectively. CONCLUSION: Male gender, hypercalcemia, and hypoparathyroidism were associated with worse outcomes. Correcting mentioned laboratory parameters may improve patients' survival in the HD population.
Asunto(s)
Fallo Renal Crónico , Trasplante de Riñón , Insuficiencia Renal Crónica , Humanos , Masculino , Teorema de Bayes , Fallo Renal Crónico/epidemiología , Diálisis RenalRESUMEN
Background No data currently exist comparing the contemporary iterations of balloon-expandable (BE) Edwards SAPIEN 3/Ultra and the self-expanding (SE) Medtronic Evolut PRO/R34 valves. The aim of the study was the comparison of these transcatheter heart valves with emphasis on patients with small aortic annulus. Methods and Results In this retrospective registry, periprocedural outcomes and midterm all-cause mortality were analyzed. A total of 1673 patients (917 SE versus 756 BE) were followed up for a median of 15 months. A total of 194 patients died (11.6%) during follow-up. SE and BE groups showed similar survival at 1 (92.6% versus 90.6%) and 3 (80.3% versus 85.2%) years (Plog-rank=0.136). Compared with the BE group, patients treated with the SE device had lower peak (16.3±8 mm Hg SE versus 21.9±8 mm Hg BE) and mean (8.8±5 mm Hg SE versus 11.5±5 mm Hg BE) gradients at discharge. Conversely, the BE group demonstrated lower rates of at least moderate paravalvular regurgitation postoperatively (5.6% versus 0.7% for SE and BE valves, respectively; P<0.001). In patients treated with small transcatheter heart valves (≤26 mm for SE and ≤23 mm for BE; N=284 for SE and N=260 for BE), survival was higher among patients treated with SE valves at both 1 (96.7% SE versus 92.1% BE) and 3 (91.8% SE versus 82.2% BE) years (Plog-rank=0.042). In propensity-matched patients treated with small transcatheter heart valve, there remained a trend for higher survival among the SE group at both 1 (97% SE versus 92.3% BE) and 3 years (91.8% SE versus 78.7% BE), Plog-rank=0.096). Conclusions Real-world comparison of the latest-generation SE and BE devices demonstrated similar survival up to 3 years' follow-up. In patients with small transcatheter heart valves, there may be a trend for improved survival among those treated with SE valves.
Asunto(s)
Estenosis de la Válvula Aórtica , Prótesis Valvulares Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Diseño de PrótesisRESUMEN
BACKGROUND: Renal disease confers a strong independent risk for morbidity and mortality after percutaneous coronary intervention (PCI). We evaluated the relationship between baseline pre-procedural renal function and outcomes following PCI. METHODS: We examined 45,287 patients who underwent PCI in British Columbia. We evaluated all-cause mortality and target vessel revascularisation (TVR) at 2 years. Pre-procedural renal impairment was categorised by creatinine clearance (CrCl, mL/min): CrCl≥90 (n=14,876), 90>CrCl≥60 (n=10,219), 60>CrCl≥30 (n=14,876), 30>CrCl≥0 (n=2,594) and dialysis (n=579). RESULTS: Declining CrCl values less than 60 mL/min were progressively associated with greater mortality: 60>eGFR≥30 (HR=2.01, 95% CI 1.71-2.37, p<0.001); 30>eGFR≥0 (HR=4.10, 95% CI 3.39-4.95, p<0.001); and dialysis (HR=6.22, 95% CI 5.07-7.63, p<0.001). A reduction in eGFR was not associated with TVR in non-dialysis patients. However, dialysis was a strong independent predictor for TVR (HR=1.69, 95% CI 1.37-2.08, p<0.001). This was confirmed in propensity-matched analyses where, dialysis was strongly associated with TVR (HR=1.53, 95% CI 1.24-1.89, p<0.001). This association was consistently seen in stratified analyses for diabetic versus non-diabetic patients; stent length >30 mm versus <30 mm; stent diameter >3 mm versus <3 mm; and receipt of bare metal stents versus drug-eluting stents. CONCLUSIONS: This study indicates the association with declining renal function and mortality in patients undergoing PCI. Whilst renal disease was not associated with increased TVR in non-dialysis patients, dialysis-dependence was a strong independent predictor for increased TVR.
Asunto(s)
Enfermedad de la Arteria Coronaria , Intervención Coronaria Percutánea , Insuficiencia Renal , Colombia Británica , Enfermedad de la Arteria Coronaria/complicaciones , Femenino , Humanos , Masculino , Intervención Coronaria Percutánea/efectos adversos , Sistema de Registros , Insuficiencia Renal/etiología , Factores de Riesgo , Stents , Resultado del TratamientoRESUMEN
Our experiments on the rod-climbing effect with an oil-coated rod revealed two key differences in the rod-climbing phenomena compared to a bare rod. First, an enhancement in the magnitude of climbing height for any particular value of the rod rotational speed and second, a decrease in the threshold rod rotational speed required for the appearance of the rod-climbing effect were observed. Observed phenomena are explained by considering the contact line behavior at the rod-fluid interface. Transient evolution of the meniscus at the rod-fluid interface revealed that the three-phase contact line was pinned for a bare rod and depinned for an oil-coated rod. We modeled the subject fluid as a Giesekus fluid to predict the climbing height. The differences in the contact line behavior were incorporated via the contact angle at the rod-fluid interface as a boundary condition. Agreement was found between the observed and predicted climbing height, establishing that contact line behavior may modulate the rod-climbing effect.
RESUMEN
AIMS: There is limited information on the role of screening with electrocardiography (ECG) for identifying cardiovascular diseases associated with sudden cardiac death (SCD) in a non-select group of adolescents and young adults in the general population. METHODS AND RESULTS: Between 2012 and 2014, 26 900 young individuals (aged 14-35 years) were prospectively evaluated with a health questionnaire and ECG. Individuals with abnormal results underwent secondary investigations, the costs of which were being based on the UK National Health Service tariffs. Six hundred and seventy-five (2.5%) individuals required further investigation for an abnormal health questionnaire, 2175 (8.1%) for an abnormal ECG, and 114 (0.5%) for both. Diseases associated with young SCD were identified in 88 (0.3%) individuals of which 15 (17%) were detected with the health questionnaire, 72 (81%) with ECG and 2 (2%) with both. Forty-nine (56%) of these individuals received medical intervention beyond lifestyle modification advice in the follow-up period of 24 months. The overall cost of the evaluation process was 97 per person screened, 17 834 per cardiovascular disease detected, and 29 588 per cardiovascular disease associated with SCD detected. Inclusion of ECG was associated with a 36% cost reduction per diagnosis of diseases associated with SCD compared with the health questionnaire alone. CONCLUSION: The inclusion of an ECG to a health questionnaire is associated with a five-fold increase in the ability to detect disease associated with SCD in young individuals and is more cost effective for detecting serious disease compared with screening with a health questionnaire alone.
Asunto(s)
Cardiopatías , Medicina Estatal , Adolescente , Muerte Súbita Cardíaca/epidemiología , Muerte Súbita Cardíaca/prevención & control , Electrocardiografía , Cardiopatías/diagnóstico , Humanos , Tamizaje Masivo , Adulto JovenRESUMEN
Hepatitis C virus (HCV) requires an essential host factor, human La protein, for its translation and replication activity. Earlier, it was demonstrated that a 24-mer synthetic peptide (LaR2C) encompassing residues 112 to 184 of the natural human La protein interacts with the HCV internal ribosome entry site (IRES) and inhibits translation. Interestingly, a shorter version of the same LaR2C peptide, LaR2C-N7, containing residues 174 to 180 (KYKETDL), with a unique ß-turn secondary structure, is sufficient to inhibit IRES mediated translation of HCV. Hence, it is imperative to understand the role of each amino acid of this heptapeptide towards ß-turn formation which will then help in designing potential drugs against HCV infection. Here, we use Nanoscale Molecular Dynamics (NAMD) simulation to investigate the factors modulating its ß-turn formation and stability. Using 100â¯ns simulation paradigms, we find that the peptide populated the type 1 ß-turn conformation in its free form in solution. However, simulation of the single-site mutants of the heptapeptide revealed that none of the 7 mutants retained the ß-turn conformation with sufficient stability. We observed that the ß-turn was stabilized mainly by the side chain interaction, salt-bridge and weak hydrogen bonds between K3 and D6 residues. Y2, K1 and K3 sites upon mutation heavily destabilized the ß-turn when compared to alteration at the E4 and T5 sites which would then drastically reduce its HCV RNA IRES binding capabilities. Taken together, our results provide a basis for designing peptidomimetics as potential anti-HCV drug candidates.
Asunto(s)
Fragmentos de Péptidos/química , Fosfoproteínas/química , Biosíntesis de Proteínas/efectos de los fármacos , Antivirales/química , Antivirales/farmacología , Hepacivirus/patogenicidad , Hepatitis C/tratamiento farmacológico , Humanos , Enlace de Hidrógeno , Simulación de Dinámica Molecular , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/farmacología , Estabilidad ProteicaRESUMEN
OBJECTIVES: The purpose of this study was to determine the potential value of a novel marker for the severity of structural heart disease and the risk of arrhythmia. BACKGROUND: The ventricular ectopic QRS interval (VEQSI) has been shown to identify structural heart disease and predict mortality in an unselected population. In ischemic heart disease (IHD), risk stratification for sudden death is imperfect. We hypothesized that VEQSI would identify patients with prior myocardial infarction (MI) compared with healthy subjects and distinguish IHD patients who have suffered life-threatening events from those without prior significant ventricular arrhythmia. METHODS: The 12-lead Holter recordings from 189 patients with previous MI were analyzed: 38 with prior ventricular tachycardia/ventricular fibrillation (MI-VT/VF) (66 ± 9 years; 92% male); 151 without prior significant ventricular arrhythmia (MI-no VT/VF) (64 ± 11 years; 74% male). These were compared with 60 healthy controls (62 ± 7 years; 70% male). All ventricular ectopic beats were reviewed and maximal VEQSI duration (VESQI max) was recorded as the duration of the longest ventricular ectopic beat. RESULTS: VEQSI max was longer in post-MI patients compared with normal controls (185 ± 26 ms vs. 164 ± 16 ms; p < 0.001) and in MI-VT/VF patients with prior life-threatening events compared with MI-no VT/VF patients without prior life-threatening events (214 ± 20 ms vs. 177 ± 22 ms; p < 0.001). Multivariate analysis established VEQSI max as the strongest independent marker for prior serious ventricular arrhythmia. VEQSI max >198 ms had 86% sensitivity, 85% specificity, 62% positive predictive value, and 96% negative predictive value for identifying patients with prior life-threatening events (odds ratio: 37.4; 95% confidence interval: 13.0 to 107.5). CONCLUSIONS: VEQSI max >198 ms distinguishes post-MI patients with prior life-threatening events from those without prior significant ventricular arrhythmia. This may be a useful additional index for risk stratification in IHD.
RESUMEN
OBJECTIVES: This study sought to investigate the prevalence of potentially abnormal electrocardiographic (ECG) patterns in young individuals to assess the implications for a nationwide screening program for conditions causing sudden cardiac death (SCD). BACKGROUND: The Italian experience suggests that pre-participation screening with ECG reduces the incidence of SCD in athletes. However, the majority of SCDs occur in nonathletes. In the United Kingdom, screening for cardiac disorders is confined to symptomatic individuals or those with a family history of inherited cardiac conditions or premature cardiac death. METHODS: Between 2008 and 2012, 7,764 nonathletes ages 14 to 35 years underwent ECG screening. Electrocardiograms were analyzed for group 1 (training-related) and group 2 (potentially pathological) patterns presented in the 2010 European Society of Cardiology position paper, which advocates further evaluation for individuals with group 2 ECG patterns. Results were compared with 4,081 athletes. RESULTS: Group 1 patterns occurred in 49.1% of nonathletes and 87.4% of athletes (p < 0.001). Group 2 patterns occurred in 21.8% of nonathletes and 33% of athletes (p < 0.001). In nonathletes, QTc interval abnormalities comprised the majority (52%) of group 2 changes, whereas T-wave inversions constituted 11%. Male sex and African/Afro-Caribbean ethnicity demonstrated the strongest association with group 2 ECG patterns. CONCLUSIONS: The study demonstrates that 1 in 5 young people have group 2 ECG patterns. The low incidence of SCD in young people suggests that in most instances such patterns are non-specific. These findings have significant implications on the feasibility and cost-effectiveness of nationwide screening programs for cardiovascular disease in young nonathletes and athletes alike, on the basis of current guidelines.
Asunto(s)
Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Electrocardiografía , Tamizaje Masivo , Adolescente , Adulto , Enfermedades Cardiovasculares/fisiopatología , Estudios Transversales , Muerte Súbita Cardíaca/epidemiología , Electrocardiografía/métodos , Femenino , Humanos , Masculino , Tamizaje Masivo/métodos , Prevalencia , Reino Unido/epidemiología , Adulto JovenRESUMEN
Sudden cardiac death (SCD) in an athlete is a rare yet highly visible tragedy that generates significant media attention and discussion among medical personnel, sports communities, and laypersons alike. The incidence of SCD is greater in athletes compared with their nonathletic counterparts due to the increased risk associated with strenuous exercise in the context of a quiescent cardiac abnormality. Numerous structural, electrical, and acquired cardiovascular abnormalities are capable of causing SCD, many of which can be identified during life and managed by lifestyle modifications, pharmacotherapy, and device therapy. Strategies for the prevention of SCD, including pre-participation cardiovascular screening, are endorsed by sports governing bodies, but mandatory pre-participation cardiovascular screening remains rare. Evaluation of athletes poses diagnostic difficulties, particularly differentiating between physiological adaptation to exercise, known as athlete's heart, and cardiomyopathic processes capable of causing SCD. This paper provides a detailed review regarding the etiology of SCD in young athletes and provides insight into the challenges and dilemmas faced when evaluating athletes for underlying pathological conditions.
Asunto(s)
Atletas , Muerte Súbita Cardíaca/prevención & control , Algoritmos , Población Negra , Cardiomiopatía Hipertrófica/diagnóstico , Muerte Súbita Cardíaca/epidemiología , Muerte Súbita Cardíaca/etiología , Diagnóstico Diferencial , Ecocardiografía , Electrocardiografía , Cardiopatías/complicaciones , Cardiopatías/diagnóstico , Humanos , Prevención Primaria , Prevención Secundaria , Medicina Deportiva , Función Ventricular Izquierda/fisiologíaRESUMEN
OBJECTIVE: To investigate the prevalence and significance of increased left ventricular (LV) trabeculation in highly trained athletes. DESIGN: Cross sectional echocardiographic study. SETTING: Sports cardiology institutions in the UK and France. SUBJECTS: 1146 athletes aged 14-35 years (63.3% male), participating in 27 sporting disciplines, and 415 healthy controls of similar age. The results of athletes fulfilling conventional criteria for LV non-compaction (LVNC) were compared with 75 patients with LVNC. MAIN OUTCOME MEASURE: Number of athletes with increased LV trabeculation and the number fulfilling criteria for LVNC. RESULTS: Athletes displayed a higher prevalence of increased LV trabeculation compared with controls (18.3% vs 7.0%; p ≤ 0.0001) and 8.1% athletes fulfilled conventional criteria for LVNC. Increased LV trabeculation were more common in athletes of African/Afro-Caribbean origin. A small proportion of athletes (n = 10; 0.9%) revealed reduced systolic function and marked repolarisation changes in association with echocardiographic criteria for LVNC raising the possibility of an underlying cardiomyopathy. Follow-up during the ensuing 48.6 ± 14.6 months did not reveal adverse events. CONCLUSIONS: A high proportion of young athletes exhibit conventional criteria for LVNC highlighting the non-specific nature of current diagnostic criteria if applied to elite athletic populations. Further assessment of such athletes should be confined to the small minority that demonstrate low indices of systolic function and marked repolarisation changes.
Asunto(s)
Atletas , Ecocardiografía , Electrocardiografía , Tolerancia al Ejercicio/fisiología , Disfunción Ventricular Izquierda/epidemiología , Función Ventricular Izquierda/fisiología , Adolescente , Adulto , Estudios Transversales , Femenino , Francia/epidemiología , Humanos , Masculino , Prevalencia , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Reino Unido/epidemiología , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatología , Adulto JovenRESUMEN
BACKGROUND: Early repolarization (ER) in the inferior electrocardiogram leads is associated with idiopathic ventricular fibrillation, but the majority of subjects with ER have a benign prognosis. At present, there are no risk stratifiers for asymptomatic ER. OBJECTIVE: To examine the response to ajmaline provocation and exercise in potentially high-risk subjects with ER and without a definitive cardiac diagnosis. METHODS: Electrocardiographic data were reviewed for ER at baseline and during ajmaline and exercise testing in 229 potentially high-risk patients (mean age 37.7±14.9 years; 55.9% men). ER was defined as J-point elevation in ≥2 consecutive leads and stratified by type, territory, J-point height, and ST-segment morphology. RESULTS: Baseline ER was present in 26 (11.4%; 19 men) patients. During ajmaline provocation and exercise, there were no new ER changes. ER with rapidly ascending ST-segment and lateral ER consistently diminished. There were 7 patients with persistent ER during ajmaline and/or exercise. They were all men with inferior or inferolateral ER and horizontal/descending ST segment. Those with persistent ER during exercise were more likely to have a history of unexplained syncope than those in whom ER changes diminished (P<.01). Subtle nondiagnostic structural abnormalities were demonstrated in 3 of these patients. CONCLUSIONS: ER with horizontal/descending ST-segment morphology in the inferior or inferolateral leads that persists during exercise is more common in patients with prior unexplained syncope and may identify patients at higher risk of arrhythmic events. ER that persists during ajmaline provocation and/or exercise may reflect underlying subtle structural abnormalities and should prompt further investigation.
Asunto(s)
Ajmalina , Electrocardiografía/métodos , Tolerancia al Ejercicio/fisiología , Sistema de Conducción Cardíaco/fisiopatología , Fibrilación Ventricular/diagnóstico , Adulto , Estudios de Cohortes , Prueba de Esfuerzo/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Cardiac adaptation to intense physical exercise is determined by factors including age, gender, body size, sporting discipline and ethnicity. Differentiating physiology from pathological conditions such as hypertrophic cardiomyopathy (HCM) is challenging, but relevant, as HCM remains the commonest cause of sudden death in young athletes. Marked electrocardiographic repolarisation changes and echocardiographic left ventricular hypertrophy have been demonstrated in athletes of black ethnicity. Such changes highlight the overlap between 'athlete's heart' and morphologically mild HCM with potential for false-positive diagnoses and disqualification from competitive sport. The focus of this article is to provide practical considerations in differentiating physiological adaptation to exercise from cardiac pathology in athletes of black ethnicity.
Asunto(s)
Población Negra , Cardiomegalia/diagnóstico , Cardiomegalia/etnología , Cardiomiopatía Hipertrófica/diagnóstico , Cardiomiopatía Hipertrófica/etnología , Ejercicio Físico , Miocardio/patología , Adaptación Fisiológica , Adolescente , Adulto , Factores de Edad , Cardiomegalia/mortalidad , Cardiomegalia/fisiopatología , Cardiomiopatía Hipertrófica/mortalidad , Cardiomiopatía Hipertrófica/fisiopatología , Muerte Súbita Cardíaca/etnología , Muerte Súbita Cardíaca/prevención & control , Diagnóstico Diferencial , Ecocardiografía , Electrocardiografía , Reacciones Falso Positivas , Femenino , Humanos , Masculino , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Adulto JovenRESUMEN
Regular and prolonged exercise is associated with increased left ventricular wall thickness that can overlap with hypertrophic cardiomyopathy (HCM). Differentiating physiological from pathological hypertrophy has important implications, since HCM is the commonest cause of exercise-related sudden cardiac death in young individuals. Most deaths have been reported in intermittent 'start-stop' sports such as football (soccer) and basketball. The theory is that individuals with HCM are unable to augment stroke volume sufficiently to meet the demands of endurance sports and are accordingly 'selected-out' of participation in such events. We report the case of an ultra-endurance athlete with 25 years of > 50 km competitive running experience, with genetically confirmed HCM; thereby demonstrating that these can be two compatible entities.
Asunto(s)
Cardiomiopatía Hipertrófica Familiar/fisiopatología , Resistencia Física , Carrera , Adulto , Enfermedades Asintomáticas , Cardiomiopatía Hipertrófica Familiar/diagnóstico , Cardiomiopatía Hipertrófica Familiar/genética , Proteínas Portadoras/genética , Análisis Mutacional de ADN , Ecocardiografía Doppler en Color , Electrocardiografía , Prueba de Esfuerzo , Predisposición Genética a la Enfermedad , Humanos , Imagen por Resonancia Magnética , Masculino , Mutación , FenotipoRESUMEN
Many prokaryotic transcription factors home in on one or a few target sites in the presence of a huge number of nonspecific sites. Our analysis of λ-repressor in the Escherichia coli genome based on single basepair substitution experiments shows the presence of hundreds of sites having binding energy within 3 Kcal/mole of the O(R)1 binding energy, and thousands of sites with binding energy above the nonspecific binding energy. The effect of such sites on DNA-based processes has not been fully explored. The presence of such sites dramatically lowers the occupation probability of the specific site far more than if the genome were composed of nonspecific sites only. Our Brownian dynamics studies show that the presence of quasi-specific sites results in very significant kinetic effects as well. In contrast to λ-repressor, the E. coli genome has orders of magnitude lower quasi-specific sites for GalR, an integral transcription factor, thus causing little competition for the specific site. We propose that GalR and perhaps repressors of the same family have evolved binding modes that lead to much smaller numbers of quasi-specific sites to remove the untoward effects of genomic DNA.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Genoma Bacteriano/genética , Modelos Biológicos , Sitios de Unión , Proteínas de Escherichia coli/metabolismo , Cinética , Proteínas Represoras/metabolismo , Termodinámica , Proteínas Reguladoras y Accesorias Virales/metabolismoRESUMEN
A simple and highly sensitive gas chromatographic method has been developed for the determination of low molecular weight short-chain aliphatic amines (SCAAs) after their simultaneous extraction and in-syringe derivatization with pentafluorobenzoyl chloride (PFBOC). Derivatization of the low molecular weight aliphatic amines in bicarbonate buffer of pH 10.5 with PFBOC was followed by immersed solvent microextraction. Derivatization conditions, including reagent concentration, reaction pH, ionic concentration of buffer, reaction time, stirring rate, reaction temperature and extraction solvent, have been investigated for method optimization. Linearity was studied within range of 0.15 pg ml⻹-50 ng ml⻹. The correlation coefficients were between 0.9934 and 0.9999. Detection limit of derivatized amines proved to be in the range of 0.117-1.527 pg ml⻹, and the intraday and interday relative standard deviation (RSD) values were less than 8% with respect to peak area. The method was applied for analysis of lake, river and industrial waste water. The recoveries of extraction from lake, river and industrial waste water samples, which have been spiked with different levels of aliphatic amines, were in the range of 68-99%, 63-102% and 62-105%, respectively.
Asunto(s)
Aminas/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Contaminantes Químicos del Agua/química , Benzoatos/química , Cromatografía de Gases y Espectrometría de Masas/instrumentación , Estructura MolecularRESUMEN
OBJECTIVES: The objective of this study was to determine the prevalence of conventional risk factors in sudden arrhythmic death syndrome (SADS) probands with Brugada syndrome (BrS). BACKGROUND: Patients with BrS and previous aborted sudden cardiac death (SCD) are at high risk of recurrent events. Other universally accepted clinical features associated with higher risk include unheralded syncope and the presence of a spontaneous type 1 electrocardiogram (ECG). METHODS: We analyzed reported symptoms and reviewed ECGs from SADS probands with familial diagnoses of BrS, established by cardiological evaluation, including ECG, 2-dimensional echocardiography, Holter monitoring, exercise tolerance testing, and ajmaline provocation. These cases underwent familial evaluation between 2003 and 2010. RESULTS: A total of 49 consecutive families with a confirmed SADS death and a diagnosis of BrS were evaluated, comprising assessment of 202 family members in total. One family had 2 members with SADS, resulting in a total of 50 probands included. Mean age of death of probands was 29.1 ± 10.6 years, with 41 males (82%) (p < 0.05). Antemortem ECGs were available for 5 SADS probands, 1 of which demonstrated a spontaneous type 1 pattern. In 45 probands, symptoms before death were reported reliably by family members. Of these, 9 (20%) had experienced at least 1 syncopal episode before the fatal event. Importantly, 68% of probands would not have fulfilled any current criteria for consideration of implantable cardioverter-defibrillator. CONCLUSIONS: The "low-risk" asymptomatic BrS group comprises the majority of SCD in this cohort. Current risk stratification would appear to be inadequate, and new markers of risk are vital.
Asunto(s)
Síndrome de Brugada/complicaciones , Síndrome de Brugada/epidemiología , Muerte Súbita/epidemiología , Muerte Súbita/etiología , Adulto , Electrocardiografía , Femenino , Humanos , Masculino , Prevalencia , Recurrencia , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Reino Unido/epidemiologíaRESUMEN
AIMS: Athletic training in male black athletes (BAs) is associated with marked ECG repolarization changes that overlap with hypertrophic cardiomyopathy (HCM). Differentiating between the two entities is prudent since BAs exhibit a higher prevalence of exercise-related sudden death from HCM compared with white athletes (WAs). METHODS AND RESULTS: Between 1996 and 2010, 904 BAs underwent serial cardiac evaluations including ECG and echocardiography. Athletes exhibiting T-wave inversions were investigated further for HCM. Results were compared with 1819 WAs, 119 black controls (BCs), and 52 black HCM patients. Athletes were followed up for 69.7 ± 29.6 months. T-wave inversions were present in 82.7% HCM patients, 22.8% BAs, 10.1% BCs, and 3.7% WAs. In athletes, the major determinant of T-wave inversions was black ethnicity. T-wave inversions in BAs (12.7%) were predominantly confined to contiguous anterior leads (V1-V4). Only 4.1% of BAs exhibited T-wave inversions in the lateral leads. In contrast, both BCs and HCM patients exhibited lower prevalence of T-wave inversions in leads V1-V4 (4.2 and 3.8%, respectively) with most T-wave inversions in HCM patients (76.9%) involving the lateral leads. During follow-up one BA survived cardiac arrest and two athletes (one BA, one WA) were diagnosed with HCM. All three exhibited T-wave inversions in the lateral leads. CONCLUSIONS: T-wave inversions in leads V1-V4 appear to represent an ethnic variant of 'athlete's heart'. Conversely, T-wave inversions in the lateral leads may represent the initial expression of underlying cardiomyopathy and merit further evaluation and regular surveillance.
Asunto(s)
Arritmias Cardíacas/diagnóstico , Población Negra , Cardiomegalia Inducida por el Ejercicio/fisiología , Cardiomiopatía Hipertrófica/diagnóstico , Deportes/fisiología , Adolescente , Adulto , Arritmias Cardíacas/etnología , Cardiomiopatía Hipertrófica/etnología , Diagnóstico Diferencial , Ecocardiografía , Electrocardiografía , Electrocardiografía Ambulatoria , Prueba de Esfuerzo , Francia/epidemiología , Sistema de Conducción Cardíaco/fisiología , Humanos , Masculino , Prevalencia , Reino Unido/epidemiología , Adulto JovenRESUMEN
During the hydrometallurgical extraction of zinc by electrowinning process, a hazardous solid waste called anode mud is generated. It contains large quantity of manganese oxides (55-80%) and lead dioxide (6-16%). Due to the presence of a large quantity of lead, the anode mud waste is considered hazardous and has to be disposed of in secure landfills, which is costly, wastes available manganese and valuable land resources. For recovery of manganese content of anode mud, a process comprising of carbothermal treatment using low density oil (LDO) followed by sulphuric acid leaching is developed.
Asunto(s)
Manganeso/aislamiento & purificación , Eliminación de Residuos , Conservación de los Recursos NaturalesRESUMEN
The beneficial effects of regular physical exercise on cardiovascular morbidity and mortality are well documented. In rare cases, however, athletes with cardiovascular abnormalities are at increased risk of exercise-related sudden cardiac death (SCD). Paradoxically, most SCDs can be attributed to cardiovascular abnormalities that can be identified during an athlete's life. Such abnormalities can be minimized by several therapeutic strategies, including insertion of an implantable cardioverter-defibrillator. Based on these considerations, the medical and sporting governing bodies recommend preparticipation cardiovascular screening (PPS) in young competitive athletes (aged Asunto(s)
Atletas
, Muerte Súbita Cardíaca/prevención & control
, Pruebas Diagnósticas de Rutina
, Adolescente
, Cardiomiopatías/diagnóstico
, Niño
, Electrocardiografía
, Femenino
, Humanos
, Masculino
, Adulto Joven