RESUMO
BACKGROUND AND PURPOSE: Surgical clipping and endovascular treatment are commonly used in patients with unruptured intracranial aneurysms. We compared the safety and efficacy of the 2 treatments in a randomized trial. MATERIALS AND METHODS: Clipping or endovascular treatments were randomly allocated to patients with one or more 3- to 25-mm unruptured intracranial aneurysms judged treatable both ways by participating physicians. The study hypothesized that clipping would decrease the incidence of treatment failure from 13% to 4%, a composite primary outcome defined as failure of aneurysm occlusion, intracranial hemorrhage during follow-up, or residual aneurysms at 1 year, as adjudicated by a core lab. Safety outcomes included new neurologic deficits following treatment, hospitalization of >5 days, and overall morbidity and mortality (mRS > 2) at 1 year. There was no blinding. RESULTS: Two hundred ninety-one patients were enrolled from 2010 to 2020 in 7 centers. The 1-year primary outcome, ascertainable in 290/291 (99%) patients, was reached in 13/142 (9%; 95% CI, 5%-15%) patients allocated to surgery and in 28/148 (19%; 95% CI, 13%-26%) patients allocated to endovascular treatments (relative risk: 2.07; 95% CI, 1.12-3.83; P = .021). Morbidity and mortality (mRS >2) at 1 year occurred in 3/143 and 3/148 (2%; 95% CI, 1%-6%) patients allocated to surgery and endovascular treatments, respectively. Neurologic deficits (32/143, 22%; 95% CI, 16%-30% versus 19/148, 12%; 95% CI, 8%-19%; relative risk: 1.74; 95% CI, 1.04-2.92; P = .04) and hospitalizations beyond 5 days (69/143, 48%; 95% CI, 40%-56% versus 12/148, 8%; 95% CI, 5%-14%; relative risk: 0.18; 95% CI, 0.11-0.31; P < .001) were more frequent after surgery. CONCLUSIONS: Surgical clipping is more effective than endovascular treatment of unruptured intracranial aneurysms in terms of the frequency of the primary outcome of treatment failure. Results were mainly driven by angiographic results at 1 year.
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Embolização Terapêutica , Procedimentos Endovasculares , Aneurisma Intracraniano , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Resultado do Tratamento , Falha de Tratamento , Procedimentos Endovasculares/métodos , Embolização Terapêutica/métodosRESUMO
Mitochondrial dysfunction caused by aberrant Complex I assembly and reduced activity of the electron transport chain is pathogenic in many genetic and age-related diseases. Mice missing the Complex I subunit NADH dehydrogenase [ubiquinone] iron-sulfur protein 4 (NDUFS4) are a leading mammalian model of severe mitochondrial disease that exhibit many characteristic symptoms of Leigh Syndrome including oxidative stress, neuroinflammation, brain lesions, and premature death. NDUFS4 knockout mice have decreased expression of nearly every Complex I subunit. As Complex I normally contains at least 8 iron-sulfur clusters and more than 25 iron atoms, we asked whether a deficiency of Complex I may lead to iron perturbations, thereby accelerating disease progression. Consistent with this, iron supplementation accelerates symptoms of brain degeneration in these mice, while iron restriction delays the onset of these symptoms, reduces neuroinflammation, and increases survival. NDUFS4 knockout mice display signs of iron overload in the liver including increased expression of hepcidin and show changes in iron-responsive element-regulated proteins consistent with increased cellular iron that were prevented by iron restriction. These results suggest that perturbed iron homeostasis may contribute to pathology in Leigh Syndrome and possibly other mitochondrial disorders.
Iron is a mineral that contributes to many vital body functions. But as people age, it accumulates in many organs, including the liver and the brain. Excess iron accumulation is linked to age-related diseases like Parkinson's disease. Too much iron may contribute to harmful chemical reactions in the body. Usually, the body has systems in place to mitigate this harm, but these mechanisms may fail as people age. Uncontrolled iron accumulation may damage essential proteins, DNA and fats in the brain. These changes may kill brain cells causing neurodegenerative diseases like Parkinson's disease. Mitochondria, the cell's energy-producing factories, use and collect iron inside cells. As people age, mitochondria fail, which is also linked with age-related diseases. It has been unclear if mitochondrial failure may also contribute to iron accumulation and associated diseases like Parkinson's. Kelly et al. show that mitochondrial dysfunction causes iron accumulation and contributes to neurodegeneration in mice. In the experiments, Kelly et al. used mice with a mutation in a key-iron processing protein in mitochondria. These mice develop neurodegenerative symptoms and die early in life. Feeding the mice a high-iron diet accelerated the animals' symptoms. But providing them with an iron-restricted diet slowed their symptoms and extended their lives. Low-iron diets also slowed iron accumulation in the animal's liver and reduced brain inflammation. The experiments suggest that mitochondrial dysfunction contributes to both iron overload and brain degeneration. The next step for scientists is understanding the processes leading to mitochondrial dysfunction and iron accumulation. Then, scientists can determine if they can develop treatments targeting these processes. This research might lead to new treatments for Parkinson's disease or other age-related conditions caused by iron overload.
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Doença de Leigh , Doenças Mitocondriais , Camundongos , Animais , Doença de Leigh/genética , Doença de Leigh/patologia , Ferro/metabolismo , Doenças Neuroinflamatórias , Doenças Mitocondriais/patologia , Mitocôndrias/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Camundongos Knockout , Mamíferos/metabolismoRESUMO
BACKGROUND AND PURPOSE: A uniform description of brain MR imaging findings in infants with severe congenital heart disease to assess risk factors, predict outcome, and compare centers is lacking. Our objective was to uniformly describe the spectrum of perioperative brain MR imaging findings in infants with congenital heart disease. MATERIALS AND METHODS: Prospective observational studies were performed at 3 European centers between 2009 and 2019. Brain MR imaging was performed preoperatively and/or postoperatively in infants with transposition of the great arteries, single-ventricle physiology, or left ventricular outflow tract obstruction undergoing cardiac surgery within the first 6 weeks of life. Brain injury was assessed on T1, T2, DWI, SWI, and MRV. A subsample of images was assessed jointly to reach a consensus. RESULTS: A total of 348 MR imaging scans (180 preoperatively, 168 postoperatively, 146 pre- and postoperatively) were obtained in 202 infants. Preoperative, new postoperative, and cumulative postoperative white matter injury was identified in 25%, 30%, and 36%; arterial ischemic stroke, in 6%, 10%, and 14%; hypoxic-ischemic watershed injury in 2%, 1%, and 1%; intraparenchymal cerebral hemorrhage, in 0%, 4%, and 5%; cerebellar hemorrhage, in 6%, 2%, and 6%; intraventricular hemorrhage, in 14%, 6%, and 13%; subdural hemorrhage, in 29%, 17%, and 29%; and cerebral sinovenous thrombosis, in 0%, 10%, and 10%, respectively. CONCLUSIONS: A broad spectrum of perioperative brain MR imaging findings was found in infants with severe congenital heart disease. We propose an MR imaging protocol including T1-, T2-, diffusion-, and susceptibility-weighted imaging, and MRV to identify ischemic, hemorrhagic, and thrombotic lesions observed in this patient group.
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Cardiopatias Congênitas , Transposição dos Grandes Vasos , Encéfalo/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Cardiopatias Congênitas/cirurgia , Humanos , Lactente , Imageamento por Ressonância Magnética , Neuroimagem , Transposição dos Grandes Vasos/diagnóstico por imagem , Transposição dos Grandes Vasos/cirurgiaRESUMO
OBJECTIVES: Conventional routine PCR testing for gastrointestinal infections is generally based on pathogen related panels specifically requested by clinicians and can be erroneous and time consuming. The BioFire FilmArray gastrointestinal (GI) panel combines 22 pathogens into a single cartridge-based test on a random-access system, thereby reducing the turnaround time to less than 2 hours. We described the clinical impact of implementing the BioFire FilmArray on patients with gastroenteritis in our hospital. METHODS: Patients attending a Dutch tertiary care center (Radboud University Medical Center), from whom stool samples were obtained, were eligible for inclusion. The clinicians selected one or a combination of different routinely performed PCR panels (bacterial panel, viral panel, clostridium testing, and three parasitic panels) based on clinical history and symptoms. All samples were in parallel tested with the FilmArray. We retrospectively collected patient data regarding infection control and patient management to assess the potential impact of implementing the FilmArray. RESULTS: In total 182 patients were included. Routine PCR detected one or more pathogens in 52 (28.6%) patients compared to 72 (39.6%) using the FilmArray. Turnaround time (including transport) decreased from median 53 hours for the routine PCR to 16 hours for the FilmArray. Twenty-six patients could have been removed from isolation 29 hours sooner, 3.6 antibiotic days could have been saved and in five patients additional imaging testing (including colonoscopies) could have been prevented. CONCLUSION: The theoretical implementation of the BioFire FilmArray GI panel in patients with clinical suspicion of gastroenteritis resulted in a significant better patient management.
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Gastroenterite/diagnóstico , Controle de Infecções/métodos , Técnicas de Diagnóstico Molecular/métodos , Assistência ao Paciente/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Fezes/microbiologia , Gastroenterite/microbiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular/instrumentação , Países Baixos , Reação em Cadeia da Polimerase/métodos , Centros de Atenção Terciária , Fatores de Tempo , Adulto JovemRESUMO
PURPOSE: Corrected T1 (cT1) value is a novel MRI-based quantitative metric for assessing a composite of liver inflammation and fibrosis. It has been shown to distinguish between non-alcoholic fatty liver disease (NAFL) and non-alcoholic steatohepatitis. However, these studies were conducted in patients at high risk for liver disease. This study establishes the normal reference range of cT1 values for a large UK population, and assesses interactions of age and gender. METHODS: MR data were acquired on a 1.5 T system as part of the UK Biobank Imaging Enhancement study. Measures for Proton Density Fat Fraction and cT1 were calculated from the MRI data using a multiparametric MRI software application. Data that did not meet quality criteria were excluded from further analysis. Inter and intra-reader variability was estimated in a set of data. A cohort at low risk for NAFL was identified by excluding individuals with BMI ≥ 25 kg/m2 and PDFF ≥ 5%. Of the 2816 participants with data of suitable quality, 1037 (37%) were classified as at low risk. RESULTS: The cT1 values in the low-risk population ranged from 573 to 852 ms with a median of 666 ms and interquartile range from 643 to 694 ms. Iron correction of T1 was necessary in 36.5% of this reference population. Age and gender had minimal effect on cT1 values. CONCLUSION: The majority of cT1 values are tightly clustered in a population at low risk for NAFL, suggesting it has the potential to serve as a new quantitative imaging biomarker for studies of liver health and disease.
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Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Adulto , Idoso , Bancos de Espécimes Biológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Estudos Retrospectivos , Fatores de Risco , Reino UnidoRESUMO
BACKGROUND: Validated diagnostic tools that are accurate, cost effective and acceptable to patients are required for disease stratification and monitoring in NAFLD. AIMS: To investigate the performance and cost of multiparametric MRI alongside existing biomarkers in the assessment of NAFLD. METHODS: Adult patients undergoing standard of care liver biopsy for NAFLD were prospectively recruited at two UK liver centres and underwent multiparametric MRI, blood sampling and transient elastography withing 2 weeks of liver biopsy. Non-invasive markers were compared to histology as the gold standard. RESULTS: Data were obtained in 50 patients and 6 healthy volunteers. Corrected T1 (cT1) correlated with NAFLD activity score (ρ = 0.514, P < .001). cT1, enhanced liver fibrosis (ELF) test and liver stiffness differentiated patients with simple steatosis and NASH with AUROC (95% CI) of 0.69 (0.50-0.88), 0.87 (0.77-0.79) and 0.82 (0.70-0.94) respectively and healthy volunteers from patients with AUROC (95% CI) of 0.93 (0.86-1.00), 0.81 (0.69-0.92) and 0.89 (0.77-1.00) respectively. For the risk stratification of NAFLD, multiparametric MRI could save £150,218 per 1000 patients compared to biopsy. Multiparametric MRI did not discriminate between individual histological fibrosis stages in this population (P = .068). CONCLUSIONS: Multiparametric MRI accurately identified patients with steatosis, stratifies those with NASH or simple steatosis and reliably excludes clinically significant liver disease with superior negative predictive value (83.3%) to liver stiffness (42.9%) and ELF (57.1%). For the risk stratification of NAFLD, multiparametric MRI was cost effective and, combined with transient elastography, had the lowest cost per correct diagnosis.
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Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Adolescente , Adulto , Idoso , Biópsia , Análise Custo-Benefício , Técnicas de Imagem por Elasticidade/economia , Técnicas de Imagem por Elasticidade/métodos , Feminino , Voluntários Saudáveis , Humanos , Fígado/patologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/economia , Imageamento por Ressonância Magnética/economia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/economia , Hepatopatia Gordurosa não Alcoólica/patologia , Valor Preditivo dos Testes , Adulto JovemRESUMO
BACKGROUND AND PURPOSE: Novel angiographic grading scales for the assessment of intracranial aneurysms treated with flow-diverting stents have been recently developed because previous angiographic grading scales cannot be applied to these aneurysms. The purpose of this study was to evaluate the inter- and intraobserver variability of the novel O'Kelly Marotta grading scale, which was developed specifically for the angiographic assessment of aneurysms treated with flow-diverting stents. MATERIALS AND METHODS: Multiple raters (n = 31) from the disciplines of neuroradiology and neurosurgery were presented with pre- and posttreatment angiographic images of 14 aneurysms treated with intraluminal flow diverters. Raters were asked to classify pre- and posttreatment angiograms by using the OKM grading scale. Statistical analyses were subsequently performed with calculation of a generalized multirater κ statistic for assessment of inter- and intraobserver variability and by performing a Wilcoxon signed rank sum test for assessment of group differences. RESULTS: Variability analysis of the OKM grading scale yielded substantial (κ = 0.74) and almost perfect (κ = 0.99) inter- and intraobserver agreement, respectively, with no statistically significant differences between raters with a background of neuroradiology versus neurosurgery or attending physician versus trainee. CONCLUSIONS: The OKM grading scale for the assessment of intracranial aneurysms treated with flow-diverting stents is a reliable grading scale that can be used equally well by users of varying backgrounds and levels of training. Comparison with interobserver variability of pre-existing angiographic grading scales shows equal or better performance.
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Prótese Vascular , Angiografia Cerebral/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Índice de Gravidade de Doença , Stents , Humanos , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
Antimicrobial peptides are secreted by the intestinal epithelium to defend from microbial threats. The role of human ß defensin-1 (hBD-1) is notable because its gene (beta-defensin 1 (DEFB1)) is constitutively expressed and its antimicrobial activity is potentiated in the low-oxygen environment that characterizes the intestinal mucosa. Hypoxia-inducible factor (HIF) is stabilized even in healthy intestinal mucosa, and we identified that epithelial HIF-1α maintains expression of murine defensins. Extension to a human model revealed that basal HIF-1α is critical for the constitutive expression of hBD-1. Chromatin immunoprecipitation identified HIF-1α binding to a hypoxia response element in the DEFB1 promoter whose importance was confirmed by site-directed mutagenesis. We used 94 human intestinal samples to identify a strong expression correlation between DEFB1 and the canonical HIF-1α target GLUT1. These findings indicate that basal HIF-1α is critical for constitutive expression of enteric DEFB1 and support targeting epithelial HIF for restoration and maintenance of intestinal integrity.
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Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/imunologia , Mucosa Intestinal/imunologia , beta-Defensinas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Células CACO-2 , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Animais , Regiões Promotoras Genéticas/genética , Ligação Proteica , Ativação Transcricional , beta-Defensinas/genéticaRESUMO
BACKGROUND AND PURPOSE: Flow-diverting stents, such as the PED, have emerged as a novel means of treating complex intracranial aneurysms. This retrospective analysis of the initial Canadian experience provides insight into technical challenges, clinical and radiographic outcomes, and complication rates after the use of flow-diverting stents for unruptured aneurysms. MATERIALS AND METHODS: Cases were compiled from 7 Canadian centers between July 2008 and December 2010. Each center prospectively tracked their initial experience; these data were retrospectively updated and pooled for analysis. RESULTS: During the defined study period, 97 cases of unruptured aneurysm were treated with the PED, with successful stent deployment in 94 cases. The overall complete or near-complete occlusion rate was 83%, with a median follow-up at 1.25 years (range 0.25-2.5 years). Progressive occlusion was witnessed over time, with complete or near-complete occlusion in 65% of aneurysms followed through 6 months, and 90% of aneurysms followed through 1 year. Multivariate analysis found previous aneurysm treatment and female sex predictive of persistent aneurysm filling. Most patients were stable or improved (88%), with the most favorable outcomes observed in patients with cavernous carotid aneurysms. The overall mortality rate was 6%. Postprocedural aneurysm hemorrhage occurred in 3 patients (3%), while ipsilateral distal territory hemorrhage was observed in 4 patients (3.4%). CONCLUSIONS: Flow-diverting stents represent an important tool in the treatment of complex intracranial aneurysms. The relative efficacy and morbidity of this treatment must be considered in the context of available alternate interventions.
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Embolização Terapêutica/instrumentação , Embolização Terapêutica/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Stents , Idoso , Canadá/epidemiologia , Angiografia Cerebral , Hemorragia Cerebral/mortalidade , Embolização Terapêutica/mortalidade , Feminino , Seguimentos , Humanos , Aneurisma Intracraniano/mortalidade , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Morbidade , Análise Multivariada , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The indications for endovascular coiling of intracranial aneurysms continue to expand. This is due, in part, to the development of intracranial specific stents which permit remodelling of complex aneurysm necks. While this approach has several advantages in the setting of unruptured aneurysms, certain challenges, in particular the requirement of concomitant antiplatelet medication, may limit its use in treatment of ruptured intracranial aneurysms. These devices can be used safely and effectively in the treatment of selected ruptured aneurysms. One must weigh the potential hemorrhagic complications against the benefits of stent assisted coiling and the disadvantages of alternative approaches.
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Aneurisma Roto/terapia , Angioplastia/métodos , Aneurisma Intracraniano/terapia , Stents , Hemorragia Subaracnóidea/terapia , Aneurisma Roto/diagnóstico por imagem , Angioplastia/efeitos adversos , Angioplastia/instrumentação , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Procedimentos Neurocirúrgicos/métodos , Radiografia , Stents/efeitos adversos , Hemorragia Subaracnóidea/diagnóstico por imagemRESUMO
BACKGROUND: Despite extensive research, the pathogenesis of polycystic ovary syndrome (PCOS) remains unclear. Putatively, an elevated circulating concentration of insulin inhibits the production of insulin-like growth factor binding protein-1 (IGFBP-1), thus increasing the level of free IGF-I in serum and stimulating ovarian androgen production. Decreased IGFBP-1 has been reported in PCOS and in obesity; however, there are inconsistencies in the evidence. This systematic review and meta-analysis aimed to determine whether IGFBP-1 is decreased in PCOS when controlling for the influence of BMI. METHODS: Articles published between 1988 and 2008 were searched using MEDLINE, PubMed, SCOPUS and Web of Knowledge. Unpublished literature, trials in progress, and recent reviews were also searched. Original articles were selected by two investigators. To be included, the study must have compared serum IGFBP-1 in two populations: either PCOS versus controls, or an overweight subgroup versus the normal weight subgroup in either population. From 617 identified articles, 12 were included in the meta-analysis. Data were abstracted by two reviewers independently and standardized for errors. RESULTS: The population difference is presented as the Weighted Mean Difference (95% CI). PCOS subjects had a significantly lower serum concentrations of IGFBP-1 compared with controls [P< 0.00001; -36.6 (-52.0, -21.2) µg/l]. Overweight PCOS subjects also had lower IGFBP-1 levels compared with normal weight PCOS subjects [P < 0.006; -30.6 (-52.3, -8.8) µg/l]. No significant difference was found between overweight PCOS patients and overweight controls [P = 0.23; -5.1 (-13.5, 3.2) µg/l] or between normal weight PCOS patients and normal weight controls [P = 0.50; -3.8 (-14.9, 7.3) µg/l]. Overweight controls had significantly lower IGFBP-1 concentrations than normal weight controls [P = 0.03; -18.0 (-34.4, - 1.5) µg/l]. CONCLUSION: These data indicate that a decreased serum level of IGFBP-1 is unlikely to be a mechanism for ovarian hyperandrogenism in PCOS. BMI may be the major determinant of serum IGFBP-1.
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Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Síndrome do Ovário Policístico/sangue , Feminino , Humanos , Obesidade/complicações , Obesidade/metabolismo , Síndrome do Ovário Policístico/complicaçõesRESUMO
Flow diverting stents are emerging as a treatment option for difficult intracranial aneurysms. Current grading scales for assessment of angiographic outcomes following aneurysm treatment do not apply to aneurysms treated by flow diversion. We propose a novel grading scale based on the degree of angiographic filling and contrast stasis. This scale will facilitate communication and standardize reporting of outcomes following flow diversion treatments.
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Angiografia Cerebral/métodos , Circulação Cerebrovascular , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Índice de Gravidade de Doença , Stents , Humanos , Valor Preditivo dos Testes , Hemorragia Subaracnóidea/prevenção & controleRESUMO
OBJECTIVES: There is lack of consensus regarding concurrent vs. staged approaches, and the prioritisation of staged procedures in cases presenting with colorectal carcinoma (CRC) and abdominal aortic aneurysm (AAA) synchronously. We aim to present our experience, review the literature on this therapeutic dilemma and examine the role of endovascular aortic repair (EVAR). DESIGN, MATERIALS AND METHODS: An observational study of the experience of two centres and a systematic review of the published literature. RESULTS: Twenty-four patients were identified from the prospective databases of two tertiary referral centres between 2001 and 2006. Intervention for both malignancy and aneurysm was performed in 13 patients. In 10 patients, cancer resection was performed initially and was followed by open aneurysm repair (n=3) or EVAR (n=7). Two patients (AAA diameters: 7.0 and 8.0cm) underwent EVAR prior to colonic resection. One patient was selected for synchronous surgery. There were no interval AAA ruptures, graft infection or postoperative mortalities. Literature review identified 269 such cases; of these 101 were treated by combined surgery. In staged surgery, there were nine interval aneurysmal ruptures and one aortic graft infection. CONCLUSIONS: In our experience, staged management can be undertaken, without interval aneurysmal rupture. EVAR has an evolving role in preventing delay in CRC management, in high-risk patients, and during combined intervention.
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Aneurisma da Aorta Abdominal/complicações , Neoplasias Colorretais/complicações , Complicações Intraoperatórias/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/diagnóstico , Aneurisma da Aorta Abdominal/cirurgia , Ruptura Aórtica/epidemiologia , Colectomia/métodos , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/cirurgia , Feminino , Seguimentos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Morbidade/tendências , Estadiamento de Neoplasias/métodos , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida/tendências , Tomografia Computadorizada por Raios X , Reino Unido/epidemiologia , Procedimentos Cirúrgicos Vasculares/métodosRESUMO
Absorption spectroscopy results on a range of type II diamonds are presented which enable the electronic states associated with them to be mapped out. High pressure, high temperature treatment of brown type IIa diamonds has enabled an activation energy for the removal of the brown colour of 8.0 ± 0.3 eV to be determined and this is consistent with expectations associated with the currently accepted vacancy cluster model for the defect. Theoretical calculations suggest that this defect will generate partially filled gap states about 1 eV above the valence band. Data on the photochromic behaviour of bands producing pink colour and their relation to brown colour are presented; these suggest that the pink bands are produced from two independent transitions with ground states close to each other just below the middle of the band gap. Compensation of neutral boron by charge transfer from states associated with brown colour is demonstrated via the correlated increase in neutral boron and decrease in brown colour on high pressure, high temperature treatment to remove the defects causing the brown colour.
RESUMO
In this paper we report on the positron lifetime results obtained for brown and colourless natural diamond. Optical effects of the observed vacancy defects in brown, high pressure, high temperature (HPHT) treated colourless and naturally colourless type IIa diamond samples were studied by combining the positron measurement with monochromatic illumination. Brown diamond was found to contain optically active vacancy clusters (40-60 missing atoms) strongly correlated with the optical absorption spectra. The optical activity of these vacancy clusters is manifested by a photo-excitation induced change of charge from neutral to negative. The clusters gradually disappear during the HPHT treatments, and the samples treated at 2500 °C resemble colourless samples optically and show similar positron lifetimes. The results show that the brown colour originates from the vacancy clusters and that their removal by the HPHT treatment causes the loss of coloration.
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INTRODUCTION: AAA screening programmes have proven to be beneficial and cost effective worldwide for males greater than 65 years of age, with 4.9% males of 65-75 years of age having an un-diagnosed AAA at screening, resulting in a 42% reduction in the risk of rupture in an English population. This study assessed the incidence of AAA and risk factors for atherosclerosis in Irish males of 55-75 years. METHODS: From April 2006 to December 2007, males between the ages of 55 and 75 years, living within the catchment area of Blanchardstown Hospital were invited for AAA screening using duplex ultrasound and cardiovascular risk factor screening. RESULTS: 1.9% (17/904) of the study population had previously un-diagnosed aneurysms detected, with sizes ranging from 3.0 cm to 5.8 cm (0.6% in 55-65 years old (yo) and 4.2% in 65-75 yo, p<0.01). 33% (302/904) of patients had hyperlipidaemia, while 16% of those with a previous diagnosis of hyperlipidaemia, were inadequately controlled on the test date. 31% of patients had a single elevated blood pressure reading, meriting further investigation for possible hypertension. 3% (28/904) of all patients had a raised glucose levels which had not previously been identified and of those who had a previous history of DM, 46% had abnormal glucose levels. 16% of patients (93/573) were morbidly obese (BMI>30) and 64% (292/573) were overweight. CONCLUSION: The incidence of AAAs in 65-75-year-old men is similar to international figures. This study confirms that screening for hyperlipidaemia, hypercholesterolaemia, obesity and hypertension may be worthwhile in all males over 55 years, while AAA screening should be reserved for 65-75-year-old Irish males.
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Aneurisma da Aorta Abdominal/diagnóstico , Aneurisma da Aorta Abdominal/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Programas de Rastreamento , Idoso , Glicemia/análise , Pressão Sanguínea , Índice de Massa Corporal , Área Programática de Saúde , Diabetes Mellitus/epidemiologia , Humanos , Hipercolesterolemia/epidemiologia , Incidência , Irlanda/epidemiologia , Masculino , Pessoa de Meia-Idade , Sobrepeso/epidemiologia , Fatores de Risco , Fumar/epidemiologia , Ultrassonografia Doppler DuplaRESUMO
BACKGROUND: Shortened trainingtimes duetothe European Working Time Directive (EWTD) and increased public scrutiny of surgical competency have led to a move away from the traditional apprenticeship model of training. Virtual reality (VR) simulation is a fascinating innovation allowing surgeons to develop without the need to practice on real patients and it may be a solution to achieve competency within a shortened training period. METHOD: A Medline search was performed to identify studies and commentaries on the use of VR simulators in endovascular training. FINDINGS: Three studies on carotid stenting and four on peripheral vascular angioplasty demonstrate that simulator training is a valid, feasible and acceptable training tool. One randomised study reports that these skills learned on simulators are transferable to the operating room. CONCLUSION: VR simulators have a role in competency based, structured training of vascular interventionalists and should improve patient safety.
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Simulação por Computador , Educação Médica Continuada/métodos , Endoscopia/educação , Interface Usuário-Computador , Doenças Vasculares/cirurgia , Procedimentos Cirúrgicos Vasculares/educação , Competência Clínica , HumanosRESUMO
BACKGROUND: We present the case of a 36-year-old female with a three-week history of a pulsatile, tender mass in the anterior triangle of the neck. METHODS: Radiology demonstrated that this was a vascular tumour deep to the sternocleidomastoid muscle. RESULTS: Pre-operative embolisation and complete surgical resection was performed. Histology revealed Castleman's disease. CONCLUSION: Unicentric hyaline vascular Castleman's disease is an unusual cause of neck mass. Surgical resection remains the best chance for cure in unicentric disease. Long term follow-up is necessary as the risk of subsequent malignancy exists.
Assuntos
Hiperplasia do Linfonodo Gigante/patologia , Pescoço/patologia , Adulto , Hiperplasia do Linfonodo Gigante/diagnóstico por imagem , Hiperplasia do Linfonodo Gigante/cirurgia , Feminino , Humanos , Pescoço/diagnóstico por imagem , Pescoço/cirurgia , RadiografiaRESUMO
BACKGROUND: The aim of this study was to investigate whether inhibition of hydroxymethylglutaryl co-enzyme A reductase attenuates leucocyte-endothelial cell interactions and alters expression of endothelial constitutive nitric oxide synthase (ecNOS) and inducible nitric oxide synthase (iNOS) following exposure to endotoxin. METHODS: Male Sprague-Dawley rats were randomized into control, lipopolysaccharide (LPS) and pravastatin + LPS groups (seven per group). Pravastatin sodium was gavaged at 0.4 mg per kg per day for 5 days, after which LPS 15 mg/kg was administered via the jugular vein. Intravital microscopy was used to determine leucocyte-endothelial cell interactions. RESULTS: Following the administration of LPS there was a significant reduction in leucocyte rolling velocity at 10 min (mean(s.e.m.) 69(3) versus 102(6) per cent of baseline value; P = 0.041), an increase in the number of adherent leucocytes at 10 min (4.5(0.5) versus 2.8(0.3) per 100 microm; P = 0.044) and an increase in the number of leucocytes undergoing transendothelial migration at 30 min (4.2(0.4) versus 1.7(0.4) per field; P = 0.008) compared with controls. Pretreatment with pravastatin significantly attenuated LPS-induced leucocyte-endothelial cell interactions (rolling velocity 89(6) per cent at 10 min, P = 0.038; adherent leucocytes 3.0(0.5) per 100 microm at 10 min, P = 0.038; migrating leucocytes 1.9(0.5) per field at 30 min, P = 0.001). This endothelial protection was associated with maintenance of ecNOS and reduced iNOS expression within mesenteric tissues. CONCLUSION: These data show that pravastatin produces anti-inflammatory effects in response to injurious stimuli by attenuation of leucocyte-endothelial cell interactions.