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AIM: The optimal diagnostic test in the work-up of suspected acute coronary syndrome (ACS) may differ between men and women. The aim of this study was to compare sex-associated differences between using a diagnostic strategy including early coronary computed tomography angiography (CCTA) and standard of care (SOC). METHODS: In total, 500 patients who presented with symptoms suggestive of ACS at the emergency department were randomised between a diagnostic strategy supplemented with early CCTA and SOC. RESULTS: Women were generally older than men (mean⯱ standard deviation 56⯱ 10 vs 53⯱ 10 years, pâ¯< 0.01) and were less often admitted to hospital (33% vs 44%, pâ¯= 0.02). Obstructive coronary artery disease on CCTA (>â¯50% luminal narrowing) was less frequently seen in women (14% vs 26%, pâ¯= 0.02), and ACS was diagnosed less often in women (5% vs 10%, pâ¯= 0.03). Women underwent less outpatient testing when early CCTA was used in the emergency department evaluation of suspected ACS (pâ¯= 0.008). CONCLUSION: Women had a lower incidence of obstructive CAD on CCTA and were less often admitted to hospital than men. They were subjected to less outpatient testing when early CCTA was used in the emergency department evaluation of suspected ACS.
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OBJECTIVES: We aimed to update data on the prevalence and incidence of systemic lupus erythematosus (SLE) in the Medicare population and describe associated outcomes. METHODS: This observational study used Medicare 20% random sample data 2007-2016 to estimate SLE prevalence and incidence 2009-2016. The study population included patients aged ≥18 years (stratified by <65 and ≥65 years) with Medicare fee-for-service coverage. The SLE definition was based on a published and validated algorithm. All-cause death, hospitalizations, and kidney disease incidence were defined for a prevalent SLE cohort 2011-2015. Unadjusted event rates during 5-year follow-up were reported per 100 patient-years. RESULTS: The study included > 5 million eligible patients for each year 2009-2016. There were 19,518 (10,898, aged ≥65; 8620, aged <65) in 2016, extrapolated to 97,590 (54,490 aged ≥65; 43,100 aged <65) in the overall 2016 Medicare population. Age- and sex-adjusted prevalence rates (per 100,000 Medicare population) ranged from 301.1 in 2009 to 366.6 in 2016, all ages, and 184.0-239.9, ≥65 years. There were 2614 (1844 aged ≥65; 770 aged <65) incident patients in 2016; age-/sex-adjusted incidence rates (per 100,000 Medicare population) ranged from 46.9 in 2009 to 49.0 in 2016, all ages, and 37.5-40.8, ≥65. Five-year unadjusted mortality, elderly vs. younger, was 8.8 vs. 3.8, morbidity 34.5 vs. 32.4, and kidney disease incidence 19.8 vs. 18.0 per 100 patient-years. CONCLUSIONS: Prevalence rates steadily increased while incidence was relatively stable 2009-2016. Our data should be interpreted with caution due to our elderly study population.
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Lúpus Eritematoso Sistêmico/epidemiologia , Medicare/estatística & dados numéricos , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Comorbidade , Estudos Transversais , Feminino , Humanos , Incidência , Masculino , Prevalência , Distribuição por Sexo , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: Endothelial dysfunction precedes coronary artery disease (CAD) and can be measured by peripheral arterial tonometry (PAT). We examined the applicability of PAT to detect a low risk of CAD in a chest pain clinic. METHODS: In 93 patients, PAT was performed resulting in reactive hyperaemia (RHI) and augmentation (AIx) indices. Patients were risk classified according to HeartScore, Diamond and Forrester pretest probability (DF), exercise testing (X-ECG), and computed tomography calcium scoring (CCS) and angiography (CTA). Correlations, risk group differences and prediction of revascularisation within 1 year were calculated. RESULTS: RHI correlated with HeartScore (r = - 0.21, p = 0.05), AIx with DF (r = 0.26, p = 0.01). However, both were not significantly different between normal and ischaemic X-ECG groups. In addition RHI and AIx were similar between low risk as compared with intermediate-to-high risk, based on risk algorithms (RHI: 1.98 (0.67) vs 1.94 (0.78); AIx: 0.0 (21) vs 5.0 (25); p = NS), or CCS and CTA (RHI: 1.99 (0.58) vs 1.89 (0.82); AIx: - 2.0 (24) vs 4.0 (25); p = NS). Finally, RHI and AIx failed to predict revascularisation (RHI: OR 1.42, CI 0.65-3.1; AIx: OR 1.02, CI 0.98-1.05). CONCLUSIONS: PAT cannot detect a low risk of CAD, possibly because RHI and AIx versus X-ECG, CCS and CTA represent independent processes.
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A 25-year-old man with a ventricular septal defect resulting from a stab wound to his chest was admitted to our hospital. Because of extensive comorbidity and favourable location, transcatheter closure with an Amplatzer device was preferred over surgical repair. Ventricular septal defects are an uncommon complication of cardiac trauma, but when they do occur from this cause, they often have more dramatic consequences. Transcatheter closure is an attractive, less-invasive alternative in patients with increased surgical risk, multiple previous surgical interventions, or poorly accessible defects.
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Septo Interventricular/lesões , Ferimentos Perfurantes/cirurgia , Adulto , Cateterismo Cardíaco , Humanos , Masculino , Dispositivo para Oclusão Septal , Resultado do Tratamento , Septo Interventricular/cirurgiaRESUMO
BACKGROUND: Gastrointestinal mucositis is defined as inflammation and/or ulcers of the gastrointestinal tract occurring as a complication of chemotherapy and radiation therapy, and affects about 50% of all cancer patients. AIM: To assess the role of gut microbiota in the pathogenesis of gastrointestinal mucositis and the potential for manipulations of the microbiota to prevent and to treat mucositis. METHODS: Search of the literature published in English using Medline, Scopus and the Cochrane Library, with main search terms 'intestinal microbiota', 'bacteremia', 'mucositis', 'chemotherapy-induced diarrhoea', 'chemotherapy-induced mucositis', 'radiotherapy-induced mucositis'. RESULTS: The gut microbiota plays a major role in the maintenance of intestinal homoeostasis and integrity. Patients receiving cytotoxic and radiation therapy exhibit marked changes in intestinal microbiota, with most frequently, decrease in Bifidobacterium, Clostridium cluster XIVa, Faecalibacterium prausnitzii, and increase in Enterobacteriaceae and Bacteroides. These modifications may contribute to the development of mucositis, particularly diarrhoea and bacteraemia. The prevention of cancer therapy-induced mucositis by probiotics has been investigated in randomised clinical trials with some promising results. Three of six trials reported a significantly decreased incidence of diarrhoea. One trial reported a decrease in infectious complications. CONCLUSIONS: The gut microbiota may play a major role in the pathogenesis of mucositis through the modification of intestinal barrier function, innate immunity and intestinal repair mechanisms. Better knowledge of these effects may lead to new therapeutic approaches and to the identification of predictive markers of mucositis.
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Antineoplásicos/efeitos adversos , Enteropatias/microbiologia , Intestinos/microbiologia , Mucosite/microbiologia , Lesões por Radiação/microbiologia , Animais , Diarreia/tratamento farmacológico , Diarreia/etiologia , Diarreia/microbiologia , Humanos , Enteropatias/tratamento farmacológico , Enteropatias/etiologia , Microbiota , Mucosite/tratamento farmacológico , Mucosite/etiologia , Neoplasias/tratamento farmacológico , Neoplasias/microbiologia , Neoplasias/radioterapia , Probióticos/uso terapêutico , Lesões por Radiação/tratamento farmacológicoRESUMO
Cardiogenic shock continues to be a life-threatening condition carrying a high mortality and morbidity, where the prognosis remains poor despite intensive modern treatment modalities. In recent years, mainly technical improvements have led to a more widespread use of short- and long-term mechanical circulatory support, such as veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and left ventricular assist devices (LVADs). Currently, LVADs are indispensable as 'bridge' to cardiac recovery, heart transplantation (HTX), and/or as destination therapy Importantly, both LVADs and HTX put a vast burden on financial resources, besides significant short- and long-term risks of morbidity and mortality. These considerations underscore the importance of optimal timing and appropriate patient selection for LVAD therapy, avoiding as much as possible an unfortunate and costly clinical path. In this report, we present a series of three cases with acute refractory cardiogenic shock ('crash and burn', INTERMACS profile 1) successfully treated by ECMO and early optimal medical therapy preventing a certain path towards LVAD and/or HTX, for which they were initially referred. This conservative approach in INTERMACS profile one patients warrants very early introduction of adequate medical heart failure therapy under the umbrella of a combination of short-term mechanical circulatory and inotropic support by phosphodiesterase inhibitors. Therefore, this novel combined medical-mechanical approach could have important clinical implications for this extremely challenging patient category, as it may avoid an unnecessary and costly clinical path towards LVAD and/or heart transplantation.
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Though conventional coronary angiography (CCA) has been the standard of reference for diagnosing coronary artery disease in the past decades, computed tomography angiography (CTA) has rapidly emerged, and is nowadays widely used in clinical practice. Here, we introduce a standardized evaluation framework to reliably evaluate and compare the performance of the algorithms devised to detect and quantify the coronary artery stenoses, and to segment the coronary artery lumen in CTA data. The objective of this evaluation framework is to demonstrate the feasibility of dedicated algorithms to: (1) (semi-)automatically detect and quantify stenosis on CTA, in comparison with quantitative coronary angiography (QCA) and CTA consensus reading, and (2) (semi-)automatically segment the coronary lumen on CTA, in comparison with expert's manual annotation. A database consisting of 48 multicenter multivendor cardiac CTA datasets with corresponding reference standards are described and made available. The algorithms from 11 research groups were quantitatively evaluated and compared. The results show that (1) some of the current stenosis detection/quantification algorithms may be used for triage or as a second-reader in clinical practice, and that (2) automatic lumen segmentation is possible with a precision similar to that obtained by experts. The framework is open for new submissions through the website, at http://coronary.bigr.nl/stenoses/.
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Algoritmos , Angiografia Coronária/normas , Estenose Coronária/diagnóstico por imagem , Reconhecimento Automatizado de Padrão/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/normas , Tomografia Computadorizada por Raios X/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Países Baixos , Intensificação de Imagem Radiográfica/métodos , Intensificação de Imagem Radiográfica/normas , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Although conventional (CAG) and computed tomography angiography (CTA) are reliable diagnostic modalities for exclusion of obstructive coronary artery disease (CAD), they are costly and with considerable exposure to radiation and contrast media. We compared the accuracy of coronary calcium scanning (CCS) and exercise electrocardiography (X-ECG) as less expensive and non-invasive means to rule out obstructive CAD. METHODS: In a rapid-access chest pain clinic, 791 consecutive patients with stable chest pain were planned to undergo X-ECG and dual-source CTA with CCS. According to the Duke pre-test probability of CAD patients were classified as low (<30%), intermediate (30-70%) or high risk (>70%). Angiographic obstructive CAD (>50% stenosis by CAG or CTA) was found in 210/791 (27%) patients, CAG overruling any CTA results. RESULTS: Obstructive CAD was found in 12/281 (4%) patients with no coronary calcium and in 73/319 (23%) with a normal X-ECG (p<0.001). No coronary calcium was associated with a substantially lower likelihood ratio compared to X-ECG; 0.11, 0.13 and 0.13 vs. 0.93, 0.55 and 0.46 in the low, intermediate and high risk group. In low risk patients a negative calcium score reduced the likelihood of obstructive CAD to less than 5%, removing the need for further diagnostic work-up. CCS could be performed in 754/756 (100%) patients, while X-ECG was diagnostic in 448/756 (59%) patients (p<0.001). CONCLUSIONS: In real-world patients with stable chest pain CCS is a reliable initial test to rule out obstructive CAD and can be performed in virtually all patients.
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Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Eletrocardiografia , Teste de Esforço , Calcificação Vascular/diagnóstico , Doença da Artéria Coronariana/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Calcificação Vascular/complicaçõesRESUMO
To conduct a comparison of the diagnostic performance of exercise bicycle testing and single-photon emission computed tomography (SPECT) with computed tomography coronary angiography (CTCA) for the detection of obstructive coronary artery disease (CAD) in patients with stable angina. 376 symptomatic patients (254 men, 122 women, mean age 60.4 ± 10.0 years) referred for noninvasive stress testing (exercise bicycle test and/or SPECT) and invasive coronary angiography were included. All patients underwent additional 64-slice CTCA. The diagnostic performance of exercise bicycle testing (ST segment depression), SPECT (reversible perfusion defect) and CTCA (≥50% lumen diameter reduction) was presented as sensitivity, specificity, positive and negative predictive value (PPV and NPV) to detect or rule out obstructive CAD with quantitative coronary angiography as reference standard. Comparisons of exercise bicycle testing versus CTCA (n = 334), and SPECT versus CTCA (n = 61) were performed. The diagnostic performance of exercise bicycle testing was significantly (P value < 0.001) lower compared to CTCA: sensitivity of 76% (95% CI, 71-82) vs. 100% (95% CI, 97-100); specificity of 47% (95% CI, 36-58) vs. 74% (95% CI, 63-82). We observed a PPV of 70% (95% CI, 65-75) vs. 91% (95% CI, 87-94); and NPV of 30% (95%, 25-35) vs. 99% (95%, 90-100). There was a statistically significant difference in sensitivity (P value < 0.05) between SPECT and CTCA: 89% (95% CI, 75-96) vs. 98% (95% CI, 87-100); but not in specificity (P value > 0.05): 77% (95% CI, 50-92) vs. 82% (95% CI, 56-95). We observed a PPV of 91% (95% CI, 77-97) vs. 93% (95% CI, 81-98); and NPV of 72% (95%, 46-89) vs. 93% (95%, 66-100). SPECT and CTCA yielded higher diagnostic performance compared to traditional exercise bicycle testing for the detection and rule out of obstructive CAD in patients with stable angina.
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Angina Pectoris/diagnóstico , Ciclismo , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Teste de Esforço , Tomografia Computadorizada Multidetectores , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Angina Pectoris/diagnóstico por imagem , Angina Pectoris/etiologia , Angina Pectoris/fisiopatologia , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/fisiopatologia , Circulação Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos , Valor Preditivo dos Testes , Sensibilidade e EspecificidadeRESUMO
PURPOSE: The authors assessed the effect of vascular attenuation and density thresholds on the classification of noncalcified plaque by computed tomography coronary angiography (CTCA). MATERIALS AND METHODS: Thirty patients (men 25; age 59 ± 8 years) with stable angina underwent arterial and delayed CTCA. At sites of atherosclerotic plaque, attenuation values (HU) were measured within the coronary lumen, noncalcified and calcified plaque material and the surrounding epicardial fat. Based on the measured CT attenuation values, coronary plaques were classified as lipid rich (attenuation value below the threshold) or fibrous (attenuation value above the threshold) using 30-HU, 50-HU and 70-HU density thresholds. RESULTS: One hundred and sixty-seven plaques (117 mixed and 50 noncalcified) were detected and assessed. The attenuation values of mixed plaques were higher than those of exclusively noncalcified plaques in both the arterial (148.3 ± 73.1 HU vs. 106.2 ± 57.9 HU) and delayed (111.4 ± 50.5 HU vs. 64.4 ± 43.4 HU) phases (p<0.01). Using a 50-HU threshold, 12 (7.2%) plaques would be classified as lipid rich on arterial scan compared with 28 (17%) on the delayed-phase scan. Reclassification of these 16 (9.6%) plaques from fibrous to lipid rich involved 4/30 (13%) patients. CONCLUSIONS: Classification of coronary plaques as lipid rich or fibrous based on absolute CT attenuation values is significantly affected by vascular attenuation and density thresholds used for the definition.
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Angiografia Coronária/métodos , Doença da Artéria Coronariana/classificação , Doença da Artéria Coronariana/diagnóstico por imagem , Placa Aterosclerótica/classificação , Placa Aterosclerótica/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Análise de Variância , Angina Estável , Técnicas de Imagem de Sincronização Cardíaca , Distribuição de Qui-Quadrado , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE: The authors investigated the prognostic value of computed tomography coronary angiography (CTCA) for major adverse cardiac events (MACE) in patients with suspected or known coronary artery disease (CAD), with particular focus on left main (LM) disease and obstructive vs. nonobstructive disease. MATERIALS AND METHODS: A total of 727 consecutive patients (485 men, age 62 ± 11 years) with suspected (514; 70.1%) or known (213; 29.9%) CAD underwent CTCA. Patients were followed up for the occurrence of MACE (i.e. cardiac death, nonfatal myocardial infarction, unstable angina, percutaneous/surgical revascularisation). RESULTS: A total of 117 MACE [five cardiac deaths, 11 acute myocardial infarctions (AMI), five unstable angina, 86 percutaneous coronary interventions, ten coronary artery bypass grafts] occurred during a mean follow-up of 20 months. Severity and extension of CAD was associated with a progressively worse prognosis. The event rate was 0% among patients with normal coronary arteries at CTCA. The presence of LM disease was not associated with a worse prognosis either in patients with no history of CAD or in those with a history of CAD. At multivariate analysis, presence of obstructive CAD and diabetes were the only independent predictors of MACE. CONCLUSIONS: Evaluation of atherosclerotic burden by CTCA provides an independent prognostic value for prediction of MACE. Patients with normal CTCA findings have an excellent prognosis at follow-up.
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Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Meios de Contraste , Doença da Artéria Coronariana/complicações , Feminino , Seguimentos , Humanos , Iopamidol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de SobrevidaRESUMO
OBJECTIVE: To compare the diagnostic performance of CT angiography (CTA) and exercise electrocardiography (XECG) in a symptomatic population with a low-intermediate prevalence of coronary artery disease (CAD). DESIGN: Prospective registry. SETTING: Tertiary university hospital. PATIENTS: 471 consecutive ambulatory patients with stable chest pain complaints, mean (SD) age 56 (10), female 227 (48%), pre-test probability for significant CAD >5%. INTERVENTION: All patients were intended to undergo both 64-slice, dual-source CTA and an XECG. Clinically driven quantitative catheter angiography was performed in 98 patients. MAIN OUTCOME MEASURES: Feasibility and interpretability of, and association between, CTA and XECG, and their diagnostic performance with invasive coronary angiography as reference. RESULTS: CTA and XECG could not be performed in 16 (3.4%) vs 48 (10.2%, p<0.001), and produced non-diagnostic results in 3 (0.7%) vs 140 (33%, p<0.001). CTA showed > or =1 coronary stenosis (> or =50%) in 140 patients (30%), XECG was abnormal in 93 patients (33%). Results by CTA and XECG matched for 185 patients (68%, p = 0.63). Catheter angiography showed obstructive CAD in 57/98 patients (58%). Sensitivity, specificity, positive and negative predictive value of CTA to identify patients with > or =50% stenosis was 96%, 37%, 67% and 88%, respectively; compared with XECG: 71%, 76%, 80% and 66%, respectively. Quantitative CTA slightly overestimated diameter stenosis: 6 (21)% (R = 0.71), compared with QCA. Of the 312 patients (66%) with a negative CTA, 44 (14%) had a positive XECG, but only 2/17 who underwent catheter angiography had significant CAD. CONCLUSION: CTA is feasible and diagnostic in more patients than XECG. For interpretable studies, CTA has a higher sensitivity, but lower specificity for detection of CAD.
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Dor no Peito/etiologia , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Doença da Artéria Coronariana/complicações , Eletrocardiografia/métodos , Teste de Esforço/métodos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Clínicas de Dor , Estudos Prospectivos , Medição de RiscoRESUMO
Multislice computed tomography coronary angiography (MSCT-CA) has emerged as a powerful noninvasive diagnostic modality to visualize the coronary arteries and to detect significant coronary stenoses. The latest generation 64-slice computed tomography (CT) scanners is a robust technique which allows high-resolution, isotropic, nearly motion-free coronary imaging. Coronary stenoses are detected with high sensitivity and a normal scan accurately rules out the presence of a coronary stenosis. With the introduction of further novel concepts in CT-technology one may expect that MSCT-CA will become a clinically used diagnostic tool.
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Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada Espiral/métodos , Humanos , Valor Preditivo dos TestesRESUMO
PURPOSE: To evaluate the diagnostic accuracy of multislice computed tomography coronary angiography (MSCT-CA) in the detection of in-stent restenosis. MATERIALS AND METHODS: Forty-two patients (33 male, 9 female, mean age 58+/-8 years) previously subjected to percutaneous implantation of coronary stent with suspected in-stent restenosis, underwent a 16-row MSCT (Sensation 16, Siemens) examination. The average time between stent implantation and MSCT-CA was 7.4+/-5.3 months. The following scan parameters were used: collimation 16x0.75 mm, rotation time 0.42 s, feed 3.0 mm/rot., kV 120, mAs 500. After administration of iodinated contrast material (Iomeprol 400 mgI/ml, 100 ml at 4 ml/s) and bolus chaser (40 ml of saline at 4 ml/s) the scan was completed in <20 s. All segments with a stent were assessed by two observers in consensus and were graded according to the following scheme: patent stent, in-stent intimal hyperplasia (IIH) (lumen reduction <50%), in-stent restenosis (ISR) (=/>50%), in-stent occlusion (ISO) (100%). Consensus reading was compared with coronary angiography. RESULTS: Forty-seven stents were assessed (16 in the right coronary artery; 4 in the left main; 22 in the left anterior descending; 5 in the circumflex). In 7 (17%) stents there was ISR (3) or ISO (4), and in 4 (10%) stents there was IIH. The sensitivity and negative predictive values for the detection of ISO were 80% and 98%, respectively, while for the detection of ISR+ISO they were 50% and 89%, respectively. CONCLUSIONS: Although the results are encouraging, the follow-up of stent patency with MSCT-CA does not show a diagnostic accuracy suitable for clinical implementation.
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Angiografia Coronária , Ponte de Artéria Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia , Tomografia Computadorizada por Raios X , Angiografia Coronária/métodos , Doença da Artéria Coronariana/fisiopatologia , Reestenose Coronária/diagnóstico por imagem , Reestenose Coronária/etiologia , Reestenose Coronária/fisiopatologia , Frequência Cardíaca/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/fisiopatologia , Interpretação de Imagem Radiográfica Assistida por Computador , Sensibilidade e Especificidade , Grau de Desobstrução Vascular/fisiologiaRESUMO
Bioremediation of soils contaminated with wood preservatives containing polycyclic aromatic hydrocarbons (PAHs) is desired because of their toxic, mutagenic, and carcinogenic properties. Creosote wood preservative-contaminated soils at the Champion International Superfund Site in Libby, Montana currently undergo bioremediation in a prepared-bed land treatment unit (LTU) process. Microbes isolated from these LTU soils rapidly mineralized the (14)C-labeled PAH pyrene in the LTU soil. Gram staining, electron microscopy, and 16S rDNA-sequencing revealed that three of these bacteria, JLS, KMS, and MCS, were Mycobacterium strains. The phylogeny of the 16S rDNA showed that they were distinct from other Mycobacterium isolates with PAH-degrading activities. Catalase and superoxide dismutase (SOD) isozyme profiles confirmed that each isolate was distinct from each other and from the PAH-degrading mycobacterium, Mycobacterium vanbaalenii sp. nov, isolated from a petroleum-contaminated soil. We find that dioxygenase genes nidA and nidB are present in each of the Libby Mycobacterium isolates and are adjacent to each other in the sequence nidB-nidA, an order that is unique to the PAH-degrading mycobacteria.
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Mycobacterium/metabolismo , Filogenia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Microbiologia do Solo , Sequência de Bases , Biodegradação Ambiental , Radioisótopos de Carbono , Catalase/metabolismo , Análise por Conglomerados , Primers do DNA , DNA Ribossômico/genética , Isoenzimas , Microscopia Eletrônica , Dados de Sequência Molecular , Montana , Mycobacterium/genética , Mycobacterium/ultraestrutura , Análise de Sequência de DNA , Especificidade da Espécie , Superóxido Dismutase/metabolismoRESUMO
Until now conventional angiography has represented the only technique for assessing the coronary arteries. During the last decade, attempts have been made to validate a non-invasive technique for the study of coronary arteries. In particular, Electron-beam Tomography and Magnetic Resonance Imaging have been used for this purpose, even though they have not become clinical tools. More recently, spiral computed tomography (CT) technology, improved by the use of multiple slices and 500ms gantry rotation times, has shown a good potential without entering routine clinical practice. The introduction of multislice technology with 16 rows and rotation times below 500ms has yielded such good results in detecting significant (>50%) coronary artery stenosis that it has been proposed as a clinical tool. This paper describes the examination technique and the results achieved in CT angiography of the coronary arteries.