RESUMO
Background: A respiratory function monitor (RFM) gives immediate feedback, allowing clinicians to adjust face mask ventilation to correct leak or inappropriate tidal volumes. We audited the satisfaction of clinicians with a neonatal resuscitation training package, incorporating a novel RFM. Methods: This was a mixed-methods study conducted at The Royal Women's Hospital, Melbourne, Australia. Clinicians were approached to complete a neonatal resuscitation training session. Participants watched a training video, then provided ventilation to term and preterm manikins first without, and then with, the RFM. Clinicians completed a survey after the session and undertook a follow-up session three months later. The primary outcome was participant satisfaction with the RFM. Secondary outcomes included participants' self-assessment of face mask leak and tidal volumes when using the RFM. Results: Fifty clinicians completed both the initial and follow-up session. Participants reported high levels of satisfaction with the RFM for both term and preterm manikins: on a scale from 0, meaning "not at all", and 100, meaning "yes, for all resuscitations", the median response (interquartile range, IQR) was 82 (74-94) vs 81.5 (69-94.5). Levels of satisfaction were similar for less experienced and more experienced clinicians: median (IQR) 83 (77-93) vs 81 (71.5-95) respectively. When using the monitor, clinicians accurately self-assessed that they achieved leak below 30% and tidal volumes within the target range at least 80% of the time. Conclusion: Clinicians of all experience levels had a high level of satisfaction with a training package including a novel RFM.
RESUMO
Ergonomics in relation to anaesthesia is the scientific study of the interaction between anaesthetists and their workspace environment in order to promote safety, performance and well-being. The foundation for avoiding pain or discomfort at work is to adopt and maintain a good posture, whether sitting or standing. Anaesthetists should aim to keep their posture as natural and neutral as possible. The successful practice of anaesthesia relies on optimisation of ergonomics and lack of attention to detail in this area is associated with impaired performance. The anaesthetic team should wear comfortable clothing, including appropriately-sized personal protective equipment where necessary. Temperature, humidity and light should be adequate at all times. The team should comply with infection prevention and control guidelines and monitoring as recommended by the Association of Anaesthetists. Any equipment or machinery that is mobile should be positioned where it is easy to view or reach without having to change the body or head position significantly when interacting with it. Patients who are supine should, whenever possible, be raised upwards to limit the need to lean towards them. Any item required during a procedure should be positioned on trays or trolleys that are close to the dominant hand. Pregnancy affects the requirements for standing, manually handling, applying force when operating equipment or moving machines and the period over which the individual might have to work without a break. Employers have a duty to make reasonable adjustments to accommodate disability in the workplace. Any member of staff with a physical impairment needs to be accommodated and this includes making provision for a wheelchair user who needs to enter the operating theatre and perform their work.
Assuntos
Ergonomia/métodos , Local de Trabalho , Extubação , Anestesia Geral , Ergonomia/instrumentação , Humanos , Umidade , Unidades de Terapia Intensiva , Intubação Intratraqueal , Iluminação , Segurança do Paciente , Equipamento de Proteção Individual , TemperaturaRESUMO
In 2018, a new practice-based small group learning (PBSGL) pilot initiative was launched in Wales to promote interprofessional learning among different primary care professionals. The aim of this study was to evaluate the initiative in order to identify its strengths and areas for improvement. Data were collected through focus groups with PBSGL groups in Wales and analysed thematically. Participants generally held positive views of PBSGL and were impressed with the variety and overall relevance of the learning materials, although concern was raised about the relevance of all learning materials to the Welsh context. The interprofessional component was valued for reducing feelings of isolation and all participants were able to contribute to discussions, an outcome helped by existing relationships among group members. Many participants reflected on occasions where they had made changes to their practice as a result of PBSGL activity. Time and funding were cited as potential barriers to continuing participation in PBSGL and there is scope to tailor material more to the context of the healthcare system in Wales.
Assuntos
Educação Médica Continuada , Processos Grupais , Humanos , Aprendizagem , Atenção Primária à Saúde , País de GalesRESUMO
Epidemiological data suggest that body mass index and obesity are strong risk factors for depression and anxiety. However, it is difficult to separate cause from effect, as predisposition to obesity may enhance susceptibility to anxiety, or vice versa. Here, we examined the effect of diet and obesity on anxiety-like behaviors in male and female selectively bred obesity-prone and obesity-resistant rats, and outbred Sprague-Dawley rats. We found that when obesity-prone and obesity-resistant rats do not differ in weight or fat mass, measures of anxiety-like behavior in the elevated plus maze and open field are similar between the two groups. However, once weight and fat mass diverge, group differences emerge, with greater anxiety in obesity-prone relative to obesity-resistant rats. This same pattern was observed for males and females. Interestingly, even when obesity-resistant rats were "forced" to gain fat mass comparable to obesity-prone rats (via prolonged access to 60% high-fat diet), anxiety-like behaviors did not differ from lean chow fed controls. In addition, a positive correlation between anxiety-like behaviors and adiposity were observed in male but not in female obesity-prone rats. Finally, diet-induced weight gain in and of itself was not sufficient to increase measures of anxiety in outbred male rats. Together, these data suggest that interactions between susceptibility to obesity and physiological alterations accompanying weight gain may contribute to the development of enhanced anxiety.
Assuntos
Ansiedade/fisiopatologia , Predisposição Genética para Doença/genética , Obesidade/complicações , Obesidade/genética , Caracteres Sexuais , Aumento de Peso , Animais , Dieta Hiperlipídica/efeitos adversos , Comportamento Exploratório/fisiologia , Feminino , Locomoção/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Obesidade/induzido quimicamente , Ratos , Ratos Sprague-Dawley , Estatísticas não ParamétricasAssuntos
Bioensaio/métodos , Compostos Heterocíclicos de 4 ou mais Anéis/administração & dosagem , Síndromes Neoplásicas Hereditárias/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Pele/efeitos dos fármacos , Administração Cutânea , Adulto , Biópsia , Receptor com Domínio Discoidina 2/antagonistas & inibidores , Receptor com Domínio Discoidina 2/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacocinética , Humanos , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/metabolismo , Síndromes Neoplásicas Hereditárias/genética , Síndromes Neoplásicas Hereditárias/patologia , Estudo de Prova de Conceito , Receptor trkB/antagonistas & inibidores , Receptor trkB/metabolismo , Pele/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologiaRESUMO
Vertebral fracture assessment (VFA) by DXA is an accepted tool in adults. However, its use in children has not been assessed. The aim of this study was to evaluate DXA VFA and morphometric analysis (MXA) using a GE Lunar iDXA bone densitometer against spinal radiographic assessment (RA) for the identification of vertebral fractures in children. Spine RA and VFA (T3-L5) were acquired on the same day in 80 children. Forty children considered high risk for fracture by their metabolic bone specialist were referred for spinal RA. Another 40 children were recruited as part of a prospective fracture study and were considered low risk for vertebral fracture. Agreement between RA and VFA was assessed by an expert paediatric radiologist and two paediatricians with expertise in bone pathology. Agreement between RA and MXA was assessed by an expert paediatric radiologist, two clinical scientists and an experienced paediatric radiographer. Vertebrae were ranked as normal, mild, moderate or severe if they had <10%, 11-25%, 26-50% and >50% deformity, respectively. Levels of agreement were calculated using the Cohen kappa score. Evaluating the data from all readable vertebrae, 121 mild, 44 moderate and 16 severe vertebral fractures were identified; with 26, 8, and 5 subjects having at least one mild, moderate or severe fracture, respectively. Depending on rater, 92.8-94.8% of the vertebrae were evaluable by RA. In contrast, 98.4% were evaluable by VFA and only 83.6% were evaluable by MXA. Moderate agreement was found between raters for RA [kappa 0.526-0.592], and VFA [kappa 0.601-0.658] and between RA and VFA [kappa 0.630-0.687]. In contrast, only slight agreement was noted between raters for MXA [kappa 0.361-0.406] and between VFA and MXA [kappa 0.137-0.325]. Agreement substantially improved if the deformities were dichotomised as normal or mild versus moderate or severe [kappa 0.826-0.834]. For the detection of moderate and/or severe fractures the sensitivities & specificities were 81.3% & 99.3%, and 62.5% & 99.2% for VFA and MXA, respectively. This study demonstrates that VFA is as good as RA for detecting moderate and severe vertebral fractures. Given the significant radiation dose saving of VFA compared with RA, VFA is recommended as a diagnostic tool for the assessment of moderate or severe vertebral fracture in children.
Assuntos
Absorciometria de Fóton , Fraturas da Coluna Vertebral/diagnóstico por imagem , Adolescente , Criança , Relação Dose-Resposta à Radiação , Humanos , Radiografia , Padrões de Referência , Fraturas da Coluna Vertebral/patologiaRESUMO
BACKGROUND: Psychiatric comorbidity is common among individuals with addictive disorders, with patients frequently suffering from anxiety disorders. While the genetic architecture of comorbid addictive and anxiety disorders remains unclear, elucidating the genes involved could provide important insights into the underlying etiology. METHODS: Here we examine a sample of 1284 Mexican-Americans from randomly selected extended pedigrees. Variance decomposition methods were used to examine the role of genetics in addiction phenotypes (lifetime history of alcohol dependence, drug dependence or chronic smoking) and various forms of clinically relevant anxiety. Genome-wide univariate and bivariate linkage scans were conducted to localize the chromosomal regions influencing these traits. RESULTS: Addiction phenotypes and anxiety were shown to be heritable and univariate genome-wide linkage scans revealed significant quantitative trait loci for drug dependence (14q13.2-q21.2, LOD=3.322) and a broad anxiety phenotype (12q24.32-q24.33, LOD=2.918). Significant positive genetic correlations were observed between anxiety and each of the addiction subtypes (ρg=0.550-0.655) and further investigation with bivariate linkage analyses identified significant pleiotropic signals for alcohol dependence-anxiety (9q33.1-q33.2, LOD=3.054) and drug dependence-anxiety (18p11.23-p11.22, LOD=3.425). CONCLUSIONS: This study confirms the shared genetic underpinnings of addiction and anxiety and identifies genomic loci involved in the etiology of these comorbid disorders. The linkage signal for anxiety on 12q24 spans the location of TMEM132D, an emerging gene of interest from previous GWAS of anxiety traits, whilst the bivariate linkage signal identified for anxiety-alcohol on 9q33 peak coincides with a region where rare CNVs have been associated with psychiatric disorders. Other signals identified implicate novel regions of the genome in addiction genetics.
Assuntos
Transtornos de Ansiedade/genética , Comportamento Aditivo/genética , Hispânico ou Latino/estatística & dados numéricos , Linhagem , Transtornos Relacionados ao Uso de Substâncias/genética , Adulto , Alcoolismo/genética , Transtornos de Ansiedade/etnologia , Comportamento Aditivo/etnologia , Comorbidade , Feminino , Ligação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Transtornos Relacionados ao Uso de Substâncias/etnologiaRESUMO
Changes in the blood expression levels of SAT1, PTEN, MAP3K3 and MARCKS genes have been reported as biomarkers of high versus low suicidality state (Le-Niculescu et al.). Here, we investigate these expression biomarkers in the Genome-Based Therapeutic Drugs for Depression (GENDEP) study, of patients with major depressive disorder on a 12-week antidepressant treatment. Blood gene expression levels were available at baseline and week 8 for patients who experienced suicidal ideation during the study (n=20) versus those who did not (n=37). The analysis is well powered to detect the effect sizes reported in the original paper. Within either group, there was no significant change in the expression of these four genes over the course of the study, despite increasing suicidal ideation or initiation of antidepressant treatment. Comparison of the groups showed that the gene expression did not differ between patients with or without treatment-related suicidality. This independent study does not support the validity of the proposed biomarkers.
Assuntos
Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/genética , RNA Mensageiro/sangue , RNA Mensageiro/genética , Ideação Suicida , Acetiltransferases/genética , Adulto , Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Feminino , Seguimentos , Expressão Gênica/genética , Marcadores Genéticos/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , MAP Quinase Quinase Quinase 3/genética , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Substrato Quinase C Rico em Alanina Miristoilada , PTEN Fosfo-Hidrolase/genéticaRESUMO
Raw and potable water sample sources, from the Umgeni Water catchment areas (rivers, dams, boreholes) in central KwaZulu-Natal (South Africa), were screened for Uranium concentration and alpha and beta radioactivity. Test methods used were gas flow proportional counting for alpha-beta radioactivity, and kinetic phosphorescence analysis (KPA), for Uranium. The uranium levels (median = 0.525 µg/L, range = <0.050-5.010) were well below the international World Health Organization (WHO) (2011) guideline for drinking-water quality (≤15 µg/L). The corresponding alpha and beta radioactivity was ≤0.5 Bq/L (median = 0.084, Interquartile Range (IR) = 0.038, range = 0.018-0.094), and ≤1.0 Bq/L (median = 0.114, IR = 0.096, range = 0.024-0.734), respectively, in compliance with the international WHO limits. For uranium radionuclide, the average dose level, at uranium level of ±0.525 µg/L, was 0.06 µSv/a, which complies with the WHO reference dose level for drinking water (<0.1 mSv/a). There was a distinct trend of cluster of relatively higher Uranium levels of some sources that were found to be associated with the geology/geography and groundwater sources. Overall, the radiological water quality classification, with respect to WHO, is "Blue" - ideal; additional physicochemical analyses indicated good water quality. The analytical test methods employed were found to be suitable for preliminary screening for potential radioactive "hot spots". The observed Uranium levels, and the alpha/beta radioactivity, indicate contribution largely from Naturally Occurring Radioactive Material (NORM), with no significant health risk to humans, or to the environment.
Assuntos
Água Potável/análise , Exposição Ambiental , Água Subterrânea/análise , Monitoramento de Radiação/métodos , Rios/química , Urânio/análise , Poluentes Radioativos da Água/análise , Partículas alfa , Partículas beta , Humanos , África do SulRESUMO
Evidence has emerged supporting a link between high glycaemic index (GI) diets and type 2 diabetes (T2D). The aim of this study was to determine if dietary GI influences the development of hyperglycaemia in C57BL/6 mice to more closely reflect T2D. Male C57BL/6 mice (n=30) were randomly divided into 3 dietary groups consisting of either standard rodent chow (4.8 % fat, 20 % protein), or a high fat (HF) diet (21-23 % fat, 19 % protein) with low GI (15.4 % starch; HF-LG) or high GI (50.5 % dextrose; HF-HG) ad libitum for 10 weeks. Body weight, blood glucose, glucose tolerance, and circulating cholesterol and triglyceride levels were measured for the duration of the study. We found that increasing the GI of a moderately HF diet induces severe hyperglycaemia and insulin resistance in C57BL/6 mice, reflective of criteria for diagnosis of T2D, whilst littermates consuming an equivalent low GI diet maintain glucose homeostasis. This study demonstrates the significant contribution of both dietary carbohydrate and fat composition in the aetiopathogenesis of T2D.
Assuntos
Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Experimental/fisiopatologia , Dieta Hiperlipídica/efeitos adversos , Carboidratos da Dieta/efeitos adversos , Índice Glicêmico/fisiologia , Hiperglicemia/etiologia , Hiperglicemia/fisiopatologia , Animais , Glicemia/metabolismo , Peso Corporal/fisiologia , Colesterol/sangue , Modelos Animais de Doenças , Ingestão de Alimentos/fisiologia , Resistência à Insulina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Triglicerídeos/sangue , Aumento de Peso/fisiologiaRESUMO
Open surgical repair of abdominal aortic aneurysms (AAAs) has been performed for over 40 years now with good results. However, the procedure continues to be high-risk with numerous potential complications. The AneuRx modular bifurcated endograft was one of the first to be tested to exclude AAAs via an endovascular approach. Data from multiple clinical trials show that treatment of AAAs with the AneuRx device is comparable to open repair with regards to mortality and may have improved short-term and long-term morbidities rates. The following review discusses clinical use of the AneuRx stent graft system from the initial clinical trial in 1996 to its current commercial use.
Assuntos
Aorta Abdominal/cirurgia , Aneurisma da Aorta Abdominal/cirurgia , Prótese Vascular , Stents , Prótese Vascular/efeitos adversos , Implante de Prótese Vascular , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Complicações Pós-Operatórias , Desenho de Prótese , Stents/efeitos adversosRESUMO
A study of the potential for the development of the Linac Coherent Light Source (LCLS) beyond the specifications of the baseline design is presented. These future developments include delivery of X-ray pulses in the 1 fs regime, extension of the spectral range, increase of the FEL power, exploitation of the spontaneous emission, and a more flexible time structure. As this potential is exploited, the LCLS can maintain its role as a world-leading instrument for many years beyond its commissioning in 2008 and initial operation as the world's first X-ray free-electron laser.
RESUMO
Public participation as a means of identifying sustainability indicators for Chongming County, Shanghai, China was evaluated by an international group drawing on established best practice. An initial 'long list' of 86 sustainability indicators, based on previous indicator systems developed in China, was identified. This 'long list' was reduced via consultations with local academics and local-government officers from Shanghai City and Chongming County to a 'short list' of 17 indicators. This short-list was subjected to further community consultation involving 159 local-government officers, teachers, students (aged 12-14 years), farmers and workers. Data from the consultations indicated differences in the understanding of sustainable development among the different sectors. By combining the data from the different sectors it was possible to identify a consensus around 4 core and 7 additional indicators. These are proposed as indicators which could be used to steer local activities directed towards sustainable development. The list of indicators produced by the people of Chongming Island was compared to local indicator systems in Europe. In comparison with European lists the Chongming list was found to have a greater emphasis on economic development but a similar level of concern for environmental matters. This study has special significance as it reports on the implementation of a process involving local resident participation in the process of sustainable development in China.
Assuntos
Benchmarking , Conservação dos Recursos Naturais/métodos , Planejamento Ambiental/normas , Mudança Social , Adolescente , Adulto , Criança , China , Participação da Comunidade , Consenso , Conservação dos Recursos Naturais/economia , Planejamento Ambiental/economia , Docentes , Combustíveis Fósseis , Prioridades em Saúde/classificação , Humanos , Condições Sociais , EstudantesRESUMO
OBJECTIVE: to report the outcome of patients with venous stasis ulceration (VSU) and severe arterial occlusive disease (AOD). DESIGN: retrospective study. METHODS: using the International Classification of Diseases (ICD-9), codes for VSU and AOD were cross-matched to identify patients from 1989 to 1999 at two tertiary hospitals. Entry into the study required the presence of a VSU and an ipsilateral procedure to improve AOD or major amputation during the same hospitalisation. RESULTS: fourteen patients (15 extremities) with a mean age of 80 years (range: 47-93) were identified as having VSU and AOD. Mean duration of VSU up to the time of revascularisation or amputation was 6.4 years (range: 4 months-21 years). The mean number of VSUs per extremity was 2.1 and mean wound area was 71 cm(2). Mean ankle-brachial index was 0.46 (range: 0.10-0.78). Nine extremities (60%) had a bypass procedure, 3 (20%) had an interventional procedure, 1 (0.6%) had a lumbar sympathectomy, and 2 (13%) had an amputation. Over a mean follow-up of 2.8 years, 3 extremities (23%) healed of which 2 recurred. On last review, 11 patients with 12 afflicted extremities had expired. Nine of the remaining 10 extremities were not healed at the time of death. Eight of nine bypass grafts remained patent in follow-up or at death and subsequent limb salvage was 100%. CONCLUSIONS: combined VSU and AOD represents a rare condition predominantly found in elderly patients with multiple comorbidities. Few patients had complete healing despite an arterial inflow procedure and mortality was high over the short term.
Assuntos
Arteriopatias Oclusivas/complicações , Arteriopatias Oclusivas/cirurgia , Avaliação de Resultados em Cuidados de Saúde , Úlcera Varicosa/complicações , Úlcera Varicosa/cirurgia , Idoso , Idoso de 80 Anos ou mais , Arteriopatias Oclusivas/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença , Taxa de Sobrevida , Fatores de Tempo , Úlcera Varicosa/mortalidadeRESUMO
Equilibrium titrations in N-methylformamide (NMF) of G-25 gel filtered (ox)-state FeMo cofactor [FeMoco(ox)] from Azotobacter vinelandii nitrogenase were carried out using sodium ethanethiolate and followed using UV/Vis absorption spectroscopy. For Fe-Moco(ox), a non-linear least squares (NLLSQ) fit to the data indicated a strong equilibrium thiolate-binding step with Keq = 1.3+/-0.2x10(6) M(-1). With 245 molar excess imidazole, cooperative binding of three ethanethiolates was observed. The best NLLSQ fit gave Keq=2.0+/-0.1x10(5) M(-2) and a Hill coefficient n=2.0+/-0.3. A Scatchard plot of these data was concave upward, indicating positive cooperativity. The fit to previously published data involving benzenethiol titration of the one-electron reduced (semi-reduced) cofactor, FeMoco(sr), as followed by EPR required a model that included both a sub-stoichiometric ratio of thiol to FeMoco(sr) and about five cooperative ligand binding sites. These constraints were met by modeling FeMoco(sr) as an aggregate, with fewer thiol binding sites than FeMoco(sr) units. The best fit model was that of FeMoco(sr) as a dodecamer with five cooperative benzenethiol binding sites, yielding a thiol binding constant of 3.32+/-0.09x10(4) M(-4.8) and a Hill coefficient n=4.8+/-0.6. The results of all the other published ligand titrations of FeMoco(sr) were similarly analyzed successfully in terms of equilibrium models that include both cooperative ligand binding and dimer-level aggregation. A possible structural model for FeMoco aggregation in NMF solution is proposed.
Assuntos
Molibdoferredoxina/química , Molibdoferredoxina/metabolismo , Compostos de Sulfidrila/metabolismo , Cianetos/química , Formamidas/química , Imidazóis/química , Ligantes , Modelos Químicos , Nitrogenase/química , Nitrogenase/metabolismo , Fenóis/química , Fenóis/metabolismo , Solventes/química , Espectrofotometria Ultravioleta , Compostos de Sulfidrila/química , TitulometriaRESUMO
Fits to the vanadium K-edge X-ray absorption spectra (XAS) of five whole blood cell samples from the tunicate Phallusia nigra revealed unprecedented forms of intracellular vanadium. Endogenous vanadium was divided between the V(III) ion (74.2+/-5.1% of total V) and the vanadyl ion [V(IV)=O](2+) (25.2+/-5.4% of total V). The V(III) fraction included both [V(H(2)O)(6)](3+) (36.7+/-5.5%) modeled as VCl(3) in 1 M HCl, and three previously unprecedented chelated V(III) forms (37.5+/-4.6%). Two of these could be represented by the model ligand environments V(acetylacetonate)(3) (17.9+/-3.2%) and K(3)V(catecholate)(3) (13.1+/-4.7%), implying DOPA-like complexation. The third chelated form was represented by the 7-coordinate N(2)O(5) complex Na[V(edta)(H(2)O)] (8.0+/-1.8%). This coordination array, suggestive of a novel mononuclear V(III) protein site, contributed only to fits to samples 1, 2, 3 and 5, which were prepared in the presence of DTT. Endogenous V(IV) (25.2+/-5.4%) was principally modeled as VOCl(2) in 1 M HCl. EPR spectra (averages: A(parallel)=(1.842+/-0.006)x10(-2) cm(-1); A( perpendicular)=(0.718+/-0.007)x10(-2) cm(-1); g(parallel)=1.936+/-0.002; g( perpendicular)=1.990+/-0.001) confirmed the predominance of the aquated vanadyl ion. Blood cell sample five uniquely required the XAS spectrum of VOSO(4) in 0.1 M H(2)SO(4) solution (13.0%) and of [OV(V)(pivalate)(3)] (3.1%) to successfully fit the XAS pre-edge energy region. This endogenous V(V) signal is also unprecedented. These results are compared with those of analogous fits to the blood cells of Ascidia ceratodes and may support assignment of P. nigra to a different genus.
Assuntos
Urocordados/metabolismo , Vanádio/química , Vanádio/metabolismo , Animais , Células Sanguíneas/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Análise Espectral , Urocordados/citologia , Raios XRESUMO
OBJECTIVE: To evaluate and compare the short- and long-term outcomes in female and male patients after carotid endarterectomy (CEA). SUMMARY BACKGROUND DATA: Randomized carotid trials have clearly shown the benefits of CEA in specific symptomatic and asymptomatic patients. However, the short- and long-term benefits in women appear to be less clear, and the role of CEA among women with carotid disease remains uncertain. METHODS: During a 21-year period, 1,204 CEAs were performed, 464 (39%) in women and 739 (61%) in men. Complete follow-up was available in 70% of patients. RESULTS: Women were less likely to have evidence of coronary artery disease, were more likely to be hypertensive, and had a significantly greater incidence of diabetes. The mean age at CEA was 68.5 +/- 9.5 years for women and 68.0 +/- 8.5 years for men. There were no significant differences in the use of shunts, patching, tacking sutures, or severity of carotid stenoses between men and women. Surgical death rates were nearly identical for asymptomatic and symptomatic patients. Perioperative stroke rates were similar for asymptomatic and symptomatic patients. Life-table stroke-free rates at 1, 5, and 8 years were similar for asymptomatic women and men and symptomatic women and men. Long-term survival rates at 1, 5, and 8 years were higher for asymptomatic women compared with men and for symptomatic women compared with men. As a result, stroke-free survival rates at these follow-up intervals were greater for asymptomatic women compared with men, and for symptomatic women compared to men. CONCLUSIONS: The results from this study challenge the conclusions from the Asymptomatic Carotid Endarterectomy Study and the North American Symptomatic Carotid Endarterectomy Trial regarding the benefits of CEA in women. Female gender did not adversely affect early or late survival, stroke-free, or stroke-free death rates after CEA. The authors conclude that CEA can be performed safely in women with asymptomatic and symptomatic carotid artery disease, and physicians should expect comparable benefits and outcomes in women and men undergoing CEA.
Assuntos
Estenose das Carótidas/mortalidade , Estenose das Carótidas/cirurgia , Endarterectomia das Carótidas/métodos , Complicações Pós-Operatórias/mortalidade , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Estenose das Carótidas/diagnóstico , Endarterectomia das Carótidas/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Probabilidade , Estudos Prospectivos , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Distribuição por Sexo , Análise de Sobrevida , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia DopplerRESUMO
Two compounds, [Fe2(mu-OH)(mu-Ph4DBA)(TMEDA)2(OTf)] (4) and [Fe2(mu-OH)(mu-Ph4DBA)(DPE)2(OTf)] (7), where Ph4DBA(2-) is the dinucleating bis(carboxylate) ligand dibenzofuran-4,6-bis(diphenylacetate), have been prepared as synthetic models for the dioxygen-binding non-heme diiron protein hemerythrin (Hr). X-ray crystallography reveals that, in the solid state, these compounds contain the asymmetric coordination environment found at the diiron center in the reduced form of the protein, deoxyHr. Mössbauer spectra of the models (4, delta = 1.21(2), DeltaE(Q) = 2.87(2) mm s(-1); 7, delta(av) = 1.23(1), DeltaE(Qav) = 2.79(1) mm s(-1)) and deoxyHr (delta = 1.19, DeltaE(Q) = 2.81 mm s(-1)) are also in good agreement. Oxygenation of the diiron(II) complexes dissolved in CH2Cl2 containing 3 equiv of N-MeIm (4) or neat EtCN (7) at -78 degrees C affords a red-orange solution with optical bands at 336 nm (7300 M(-1) cm(-1)) and 470 nm (2600 M(-1) cm(-1)) for 4 and at 334 nm (6400 M(-1) cm(-1)) and 484 nm (2350 M(-1) cm(-1)) for 7. These spectra are remarkably similar to that of oxyHr, 330 nm (6800 M(-1) cm(-1)) and 500 nm (2200 M(-1) cm(-1)). The electron paramagnetic resonance (EPR) spectrum of the cryoreduced, mixed-valence dioxygen adduct of 7 displays properties consistent with a (mu-oxo)diiron(II,III) core. An investigation of 7 and its dioxygen-bound adduct by extended X-ray absorption fine structure (EXAFS) spectroscopy indicates that the oxidized species contains a (mu-oxo)diiron(III) core with iron-ligand distances in agreement with those expected for oxide, carboxylate, and amine/hydroperoxide donor atoms. The analogous cobalt complex [Co2(mu-OH)(mu-Ph4DBA)(TMEDA)2(OTf)] (6) was synthesized and structurally characterized, but it was unreactive toward dioxygen.
Assuntos
Hemeritrina/química , Peróxido de Hidrogênio/química , Ferroproteínas não Heme/química , Cristalografia por Raios X , Espectroscopia de Ressonância de Spin Eletrônica , Ligantes , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Oxirredução , Espectroscopia de Mossbauer , Análise Espectral RamanRESUMO
X-ray absorption spectroscopy (XAS) at the sulfur ( approximately 2470 eV) and chlorine ( approximately 2822 eV) K-edges has been applied to a series of 4Fe-4S model complexes. These are compared to 2Fe-2S model complexes to obtain insight into the localized ground state in the mixed-valence dimer versus the delocalized ground state in the mixed-valence tetramer. The preedges of hypothetical delocalized mixed-valence dimers [Fe(2)S(2)](+) are estimated using trends from experimental data and density functional calculations, for comparison to the delocalized mixed-valence tetramer [Fe(4)S(4)](2+). The differences between these two mixed-valence sites are due to the change of the sulfide-bridging mode from micro(2) to micro(3). The terminal chloride and thiolate ligands are used as spectator ligands for the electron density of the iron center. From the intensity of the preedge, the covalency of the terminal ligands is found to increase in the tetramer as compared to the dimer. This is associated with a higher effective nuclear charge on the iron in the tetramer (derived from the energies of the preedge). The micro(3)-bridging sulfide in the tetramer has a reduced covalency per bond (39%) as compared to the micro(2)-bridging sulfide in the dimer (51%). A simple perturbation model is used to derive a quadratic dependence of the superexchange coupling constant J on the covalency of the metal ions with the bridging ligands. This relationship is used to estimate the superexchange contribution in the tetramer (J = -156 cm(-)(1)) as compared to the mixed-valence dimer (J = -360 cm(-)(1)). These results, combined with estimates for the double exchange and the vibronic coupling contributions of the dimer sub-site of the tetramer, lead to a delocalized S(t) = (9)/(2) spin ground state for the mixed-valence dimer in the tetramer. Thus, the decrease in the covalency, hence the superexchange pathway associated with changing the bridging mode of the sulfides from micro(2) to micro(3) on going from the dimer to the tetramer, significantly contributes to the delocalization of the excess electron over the dimer sub-site in the tetramer.