RESUMO
KEY MESSAGE: Here, we provide an updated set of guidelines for naming genes in wheat that has been endorsed by the wheat research community. The last decade has seen a proliferation in genomic resources for wheat, including reference- and pan-genome assemblies with gene annotations, which provide new opportunities to detect, characterise, and describe genes that influence traits of interest. The expansion of genetic information has supported growth of the wheat research community and catalysed strong interest in the genes that control agronomically important traits, such as yield, pathogen resistance, grain quality, and abiotic stress tolerance. To accommodate these developments, we present an updated set of guidelines for gene nomenclature in wheat. These guidelines can be used to describe loci identified based on morphological or phenotypic features or to name genes based on sequence information, such as similarity to genes characterised in other species or the biochemical properties of the encoded protein. The updated guidelines provide a flexible system that is not overly prescriptive but provides structure and a common framework for naming genes in wheat, which may be extended to related cereal species. We propose these guidelines be used henceforth by the wheat research community to facilitate integration of data from independent studies and allow broader and more efficient use of text and data mining approaches, which will ultimately help further accelerate wheat research and breeding.
Assuntos
Melhoramento Vegetal , Triticum , Triticum/genética , Fenótipo , Genes de Plantas , Grão Comestível/genéticaRESUMO
The lower flammability limit (LFL) of a fuel is the minimum composition in air over which a flame can propagate. Calculated adiabatic flame temperatures (CAFT) are a powerful tool to estimate the LFL of gas mixtures. Different CAFT values are used for the estimation of LFL. SuperChems is used by industry to perform flammability calculations under different initial conditions which depends on the selection of a threshold temperature. In this work, the CAFT at the LFL is suggested for mixtures of fuel-air and fuel-air-diluents. These CAFT can be used as the threshold values in SuperChems to calculate the LFL. This paper discusses an approach to evaluate the LFL in the presence of diluents such as N2 and CO2 by an algebraic method and by the application of SuperChems using CAFT as the basis of the calculations. The CAFT for different paraffinic and unsaturated hydrocarbons are presented as well as an average value per family of chemicals.
Assuntos
Ar , Misturas Complexas/química , Incêndios , Combustíveis Fósseis , Modelos Estatísticos , Software , TemperaturaRESUMO
Thermal stability evaluation of exothermic chemical reactions is of great importance to the safer design and operation of chemical processes. Dominant reaction stoichiometries and their thermochemistry parameters are key elements in the evaluation process. Identification of significant reaction pathways under possible process conditions will lead to an understanding of the overall thermodynamic and kinetic behavior. The kinetics of 1,3-butadiene (BD) is an excellent example of conjugated dienes that undergo addition reactions. At elevated temperatures, 1,3-butadiene monomers can dimerize exothermally, and as temperature increases, secondary exothermic reactions will take place. The very high temperature and pressure rates that these reactions can attain may lead to a reaction runaway or even a thermal explosion. BD is a vapor at ambient conditions, usually stored as a pressurized liquid, and is a carcinogen, so the experimental evaluation is potentially difficult and hazardous. In this paper, the thermal stability of BD is evaluated. Dimerization and other secondary reactions are investigated by experimental thermal analysis using an automatic pressure adiabatic calorimeter (APTAC), by theoretical computational quantum chemistry methods, and empirical thermodynamic-energy correlations. A theoretical approach is conducted to predict some of the BD reaction behavior. Results are compared to other literature data obtained using different experimental methods.
Assuntos
Butadienos/química , Oxigênio/química , Calorimetria/métodos , Dimerização , Modelos Químicos , TemperaturaRESUMO
BACKGROUND: to date, only three groups have reported data from large scale genetic association studies of coronary heart disease using a case control design. METHODS AND RESULTS: to extend our initial report of 62 genes, we present data for 210 polymorphisms in 111 candidate genes genotyped in 352 white subjects with familial, premature coronary heart disease (onset age for men, 45; for women, 50) and a random sample of 418 population based whites. Multivariate logistic regression analysis was used to compare the distributions of genotypes between cases and the comparison group while controlling for age, sex, body mass, diabetes, and hypertension. Significant associations were found with polymorphisms in thrombospondin-4 (THBS4), thrombospondin-2 (THBS2) and plasminogen activator inhibitor-2 (PAI2), the strongest being with the A387P variant in THBS4 (p = 0.002). The THBS2 and THBS4 associations have since been replicated. We evaluated polymorphisms in 40 genes previously associated with coronary heart disease and found significant (p<0.05) associations with 10: ACE, APOE, F7, FGB, GP1BA, IL1RN, LRP1, MTHFR, SELP, and THPO. For five of these genes, the polymorphism associated in our study was different from that previously reported, suggesting linkage disequilibrium as an explanation for failure to replicate associations consistently across studies. We found strong linkage disequilibrium between polymorphisms within and between genes, especially on chromosome 1q22-q25, a region containing several candidate genes. CONCLUSIONS: despite known caveats of genetic association studies, they can be an effective means of hypothesis generation and complement classic linkage studies for understanding the genetic basis of coronary heart disease.
Assuntos
Doença das Coronárias/genética , Predisposição Genética para Doença , Polimorfismo Genético , Adulto , Idoso , Doença das Coronárias/diagnóstico , Feminino , Genótipo , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Análise de Sequência de DNARESUMO
Employing equipment reliability databases can generate a process of continual improvement. This paper suggests a methodology that uses equipment reliability databases, and a process of benchmarking to establish a continual improvement procedure by learning "how others are doing it". A simple decision-making procedure is suggested too, to assist in prioritizing the processes/equipment that are considered to be improved as well as a methodology to measure the improvement.
Assuntos
Bases de Dados Factuais , Substâncias Perigosas , Segurança , Previsões , Reprodutibilidade dos Testes , Medição de RiscoRESUMO
Evaluation of thermal stability and runaway behavior of any exothermic chemical system is of great importance for the design and operation of a chemical process. The evaluation process should be based on a thorough investigation of the reaction chemistry including reaction pathways, thermodynamic, and kinetic parameters. When addressing the reactivity hazards of any reacting system, the dominant pathway(s) should be identified. Identifying the main reaction pathway under specific conditions will lead to a better thermodynamic and kinetic characterization of the reacting system. In this article, the thermal stability and runaway behavior of styrene-acrylonitrile copolymerization reaction system in bulk is evaluated. Traditional thermal analysis techniques (calorimetric analysis) are combined with computational quantum chemistry methods and empirical thermodynamic-energy correlations. Reaction pathways are identified from the theoretical approach and verified by experimental measurements. The results of this analysis are compared to literature data for this system.
Assuntos
Acrilonitrila/química , Modelos Químicos , Estireno/química , Calorimetria , Explosões , Substâncias Perigosas , Cinética , Polímeros , Medição de Risco , TemperaturaAssuntos
Proteínas de Transporte , Doença da Artéria Coronariana/genética , Variação Genética/genética , Lipídeos/genética , Lipoproteínas HDL , Proteínas de Membrana , Proteínas de Ligação a RNA , Receptores Imunológicos/genética , Receptores de Lipoproteínas/genética , Caracteres Sexuais , Adulto , Idoso , Alelos , Doença da Artéria Coronariana/etiologia , Feminino , Predisposição Genética para Doença/genética , Humanos , Masculino , Pessoa de Meia-Idade , Receptores Depuradores , Receptores Depuradores Classe BRESUMO
There is considerable interest in prediction of reactive hazards based on chemical structure. Calorimetric measurements to determine reactivity can be resource consuming, so computational methods to predict reactivity hazards present an attractive option. This paper reviews some of the commonly employed theoretical hazard evaluation techniques, including the oxygen-balance method, ASTM CHETAH, and calculated adiabatic reaction temperature (CART). It also discusses the development of a study table to correlate and predict calorimetric properties of pure compounds. Quantitative structure-property relationships (QSPR) based on quantum mechanical calculations can be employed to correlate calorimetrically measured onset temperatures, T(o), and energies of reaction, -deltaH, with molecular properties. To test the feasibility of this approach, the QSPR technique is used to correlate differential scanning calorimeter (DSC) data, T(o) and -deltaH, with molecular properties for 19 nitro compounds.
Assuntos
Calorimetria , Matemática , Modelos Químicos , TemperaturaRESUMO
OBJECTIVES: We sought to evaluate the ability of psychiatric anxiety-disorder history to discriminate between women with and without angiographic coronary artery disease (CAD) in a population with chest pain. BACKGROUND: A total of 435 women with chest pain underwent a diagnostic battery including coronary angiography in order to improve testing guidelines for women with suspected CAD. METHODS: Women referred for coronary angiography completed questionnaires assessing prior treatment history for anxiety disorder and current anxiety-related symptoms. Analyses controlled for standard CAD risk factors. RESULTS: Forty-four women (10%) reported receiving prior treatment for an anxiety disorder. This group acknowledged significantly higher levels of autonomic symptoms (e.g., headaches, muscle tension [F = 25.0, p < 0.0011 and higher behavioral avoidance scores (e.g., avoidance of open places or traveling alone by bus [F = 4.2, p < 0.05]) at baseline testing compared with women without prior anxiety problems. Women with an anxiety-disorder history did not differ from those without such a history with respect to the presence of inducible ischemia or use of nitroglycerin, although they were younger and more likely to describe both "tight" and "sharp" chest pain symptoms and to experience back pain and episodes of nocturnal chest pain. Logistic regression results indicated that the positive-anxiety-history group was more likely to be free of underlying significant angiographic CAD (odds ratio = 2.74, 95% confidence interval 1.15 to 6.5, p = 0.03). CONCLUSIONS: Among women with chest pain symptoms, a history of anxiety disorders is associated with a lower probability of significant angiographic CAD. Knowledge of anxiety disorder history may assist in the clinical evaluation of women with chest pain.
Assuntos
Transtornos de Ansiedade/epidemiologia , Dor no Peito/epidemiologia , Doença das Coronárias/epidemiologia , Adulto , Comorbidade , Angiografia Coronária , Doença das Coronárias/diagnóstico por imagem , Feminino , Indicadores Básicos de Saúde , Humanos , Modelos Logísticos , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Recent advances in high-throughput genomics technology have expanded our ability to catalogue allelic variants in large sets of candidate genes related to premature coronary artery disease. METHODS AND RESULTS: A total of 398 families were identified in 15 participating medical centers; they fulfilled the criteria of myocardial infarction, revascularization, or a significant coronary artery lesion diagnosed before 45 years in men or 50 years in women. A total of 62 vascular biology genes and 72 single-nucleotide polymorphisms were assessed. Previously undescribed variants in 3 related members of the thrombospondin protein family were prominent among a small set of single-nucleotide polymorphisms that showed a statistical association with premature coronary artery disease. A missense variant of thrombospondin 4 (A387P) showed the strongest association, with an adjusted odds ratio for myocardial infarction of 1.89 (P=0.002 adjusted for covariates) for individuals carrying the P allele. A variant in the 3' untranslated region of thrombospondin-2 (change of thymidine to guanine) seemed to have a protective effect against myocardial in individuals homozygous for the variant (adjusted odds ratio of 0.31; P=0.0018). A missense variant in thrombospondin-1 (N700S) was associated with an adjusted odds ratio for coronary artery disease of 11.90 (P=0.041) in homozygous individuals, who also had the lowest level of thrombospondin-1 by plasma assay (P=0.0019). CONCLUSIONS: This large-scale genetic study has identified the potential of multiple novel variants in the thrombospondin gene family to be associated with familial premature myocardial infarction. Notwithstanding multiple caveats, thrombospondins specifically and high-throughput genomic technology in general deserve further study in familial ischemic heart disease.
Assuntos
Doença da Artéria Coronariana/genética , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/genética , Polimorfismo de Nucleotídeo Único/genética , Trombospondinas/genética , Adulto , Idade de Início , Alelos , Estudos de Casos e Controles , Angiografia Coronária , Doença da Artéria Coronariana/epidemiologia , Estenose Coronária/diagnóstico , Estenose Coronária/genética , Demografia , Feminino , Predisposição Genética para Doença , Testes Genéticos , Genótipo , Homozigoto , Humanos , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2) , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Razão de Chances , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Valor Preditivo dos Testes , Trombospondina 1/genética , Estados UnidosRESUMO
BACKGROUND: Immediate reperfusion therapy to restore coronary blood flow is recommended for all eligible patients with acute myocardial infarction. However, reperfusion therapy is reportedly underutilized among African Americans, even when they are eligible. Reasons for the lack of use have not been fully explored. METHODS: We examined the demographic, clinical, and treatment data of 10,469 African Americans with acute myocardial infarction who were eligible for reperfusion therapy, enrolled in the National Registry of Myocardial Infarction-2 from June 1994 through March 1998. RESULTS: The mean age was 62.58 (+/-14.4) years, and 44.7% were female. Although eligible, 47% of the African Americans in this study did not receive reperfusion therapy. In a multivariate analysis, the absence of chest pain at presentation (odds ratio [OR] 0.31, 95% CI 0.26-0.37) and initial admission diagnoses other than definite myocardial infarction (OR for receipt of reperfusion <0.12) were the strongest predictors of lack of early reperfusion therapy. Progressive delays in hospital arrival and hospital evaluation predicted a lower likelihood of early reperfusion. Prior stroke (OR 0.63, 95% CI 0.50-0.78), myocardial infarction (OR 0.75, 95% CI 0.65-0.86), and congestive heart failure (OR 0.49, 95% CI 0.40-0.60) were all associated with lack of reperfusion therapy. CONCLUSION: Almost half of eligible African American patients with myocardial infarction did not receive reperfusion therapy. Potential reasons may include atypical presentation, patient and institutional delay, and underappreciation of myocardial infarction by care providers. Strategies to address these factors may improve the rate of use of reperfusion therapy.
Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Infarto do Miocárdio/cirurgia , Reperfusão Miocárdica/estatística & dados numéricos , Doença Aguda , Angioplastia/estatística & dados numéricos , Comorbidade , Ponte de Artéria Coronária/estatística & dados numéricos , Feminino , Insuficiência Cardíaca/epidemiologia , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Reperfusão Miocárdica/tendências , Seleção de Pacientes , Estudos Prospectivos , Sistema de Registros/estatística & dados numéricos , Acidente Vascular Cerebral/epidemiologia , Terapia Trombolítica/estatística & dados numéricos , Fatores de Tempo , Resultado do TratamentoRESUMO
Women with obstructive coronary disease appear to be more challenging diagnostically and suffer a more adverse prognosis than men. More than one half of women with symptoms of ischemic heart disease have no obstructive coronary artery disease at coronary angiography, yet these women frequently have persistent symptom-related disability and consume large amounts of healthcare resources. Prior evidence has been limited regarding effective diagnostic strategies for the assessment of symptomatic women. The current report synthesizes existing evidence on diagnostic testing in women, including research from the ongoing National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) study. In addition to recent published evidence (drawn from much larger cohorts of women) that stress echocardiography and nuclear imaging are similar in their ability to risk-stratify women, the WISE study is exploring new pathophysiological mechanisms of microvascular dysfunction in women. An unfolding body of evidence suggests that as tests become more diagnostically and prognostically accurate, the process will become more cost efficient. The results from a growing number of large observational series and National Institutes of Health-sponsored studies are expected to be the foundation for cost-effective diagnostic and prognostic strategies for the approximately 5 million women who undergo evaluation for coronary disease annually.
Assuntos
Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/economia , Efeitos Psicossociais da Doença , Saúde da Mulher , Dor no Peito/diagnóstico , Dor no Peito/economia , Doença da Artéria Coronariana/fisiopatologia , Doença da Artéria Coronariana/terapia , Gerenciamento Clínico , Feminino , Humanos , Prognóstico , Estados UnidosRESUMO
The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that mediates many of the biological and toxicological actions of a diverse range of chemicals, including the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin). Although no endogenous physiological ligand for the AhR has yet been described, numerous studies support the existence of such a ligand(s). Here we have examined the ability of prostaglandins and related chemicals to activate the AhR signaling system. Using two AhR-based bioassay systems we report that relatively high concentrations of several prostaglandins (namely, PGB3, PGD3, PGF3alpha, PGG2, PGH1, and PGH2) can not only stimulate AhR transformation and DNA binding in vitro, but also induce AhR-dependent reporter gene expression in mouse hepatoma cells in culture. PGG2 also induced AhR-dependent reporter gene expression to a level three-to four fold greater than that observed with a maximal inducing dose of TCDD. Sucrose gradient ligand binding analysis revealed that PGG2 could competitively displace [3H]TCDD from the AhR. Overall, our results demonstrate that selected prostaglandins are weak agonists for the AhR and they represent a structurally distinct and novel class of activator of the AhR signal transduction pathway.
Assuntos
Prostaglandinas/farmacologia , Receptores de Hidrocarboneto Arílico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Células Cultivadas , Centrifugação com Gradiente de Concentração , Cromatografia em Gel , Citosol/metabolismo , DNA/biossíntese , DNA/genética , Dinoprostona/farmacologia , Relação Dose-Resposta a Droga , Cobaias , Fígado/efeitos dos fármacos , Fígado/metabolismo , Luciferases/metabolismo , Masculino , Camundongos , Dibenzodioxinas Policloradas/farmacologia , Receptores de Hidrocarboneto Arílico/genética , Transdução de Sinais/genética , SacaroseRESUMO
OBJECTIVES: This study was designed to determine noninvasively the age-associated changes in regional mechanical properties in normals using phase-contrast magnetic resonance imaging (PCMRI). BACKGROUND: It has been well documented that there is a progressive increase in aortic pulse wave velocity (PWV) with age. Previously, PWV has been measured at a single aortic location, or has compared arterial waves between carotid and femoral points to determine PWV. METHODS: Applanation tonometry (TONO) and in-plane PCMR was performed in 24 volunteers (12 men) ranging in age from 21 to 72 years old. The PCMRI PWV was measured in three aortic segments. As validation, TONO was performed to determine PWV between the carotid and femoral artery. RESULTS: When PCMRI PWV was averaged over the three locations, it was not different from TONO (7.9 +/- 2.3 vs. 7.6 +/- 2.4 m/s, respectively). When the volunteers were divided into groups of < 55 and > or =55 years old, the younger group showed similar PWV at each aortic location. However, the older group displayed significantly increased PWV in the region spanning the ascending and proximal descending aorta compared with the mid-thoracic or abdominal segments (10.6 +/- 2.5 m/s, 9.2 +/- 2.8 m/s, and 7.1 +/- 1.7 m/s, respectively, p < 0.001, analysis of variance). CONCLUSIONS: In-plane PCMRI permits determination of PWV in multiple aortic locations in a single acquisition. Progressive fragmentation of elastic fibers and alterations in the regulation of vascular tone may result in an age-related, regional increase in PWV primarily affecting the proximal aorta.
Assuntos
Envelhecimento/fisiologia , Aorta/fisiologia , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Pessoa de Meia-Idade , TransdutoresRESUMO
The activity of endo-beta-mannanase ([1-->4]-beta-mannan endohydrolase EC 3.2.1.78) is likely to be central to the metabolism of cell wall mannans during the germination of grains of coffee (Coffea spp.). In the present paper, we report the cloning and sequencing of two endo-beta-mannanase cDNAs (manA and manB) by different strategies from Coffea arabica L.. The manA cDNA was obtained by the use of oligonucleotides homologous to published sequences of other endo-beta-mannanases and manB by the use of oligonucleotides deduced from a purified enzyme from coffee. ManA and B proteins share about 56% sequence homology and include highly conserved regions found in other mannan endohydrolases. Purification of the activity by chromatography followed by separation by two-dimensional electrophoresis and amino acid sequencing demonstrated the existence of at least seven isomers of the ManB form. The existence of multiple manB genes was also indicated by Southern analysis, whereas only one or two gene copies were detected for manA. Northern hybridizations with manA- and manB-specific probes showed that mRNA transcripts for both cDNAs were present at the same periods of bean germination with transcript peaks at 20 days after imbibition of water (DAI). Transcripts were not detected during grain maturation or in the other tissues such as roots, stems, flowers and leaves. The peak endo-beta-mannanase activity occurred at approximately 28 DAI and was not detected in grains prior to imbibition. Activity and mRNA levels appeared to be tightly co-ordinated. Tests of substrate specificity with the purified ManB enzyme showed that activity required a minimum of five mannose units to function efficiently.
Assuntos
Café/enzimologia , Manosidases/genética , Sementes/enzimologia , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Café/química , Eletroforese em Gel Bidimensional , Germinação , Ponto Isoelétrico , Manosidases/química , Manosidases/metabolismo , Dados de Sequência Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/química , Alinhamento de Sequência , Análise de Sequência de ProteínaRESUMO
BACKGROUND: ACE inhibition (ACEI) attenuates post-myocardial infarction (MI) LV remodeling, but the effects of angiotensin II type 1 receptor (AT(1)) antagonism alone or in combination with ACEI are unclear. Accordingly, we investigated the effects of AT(1) antagonism, ACEI, and their combination in a well-characterized ovine postinfarction model. METHODS AND RESULTS: Beginning 2 days after transmural anteroapical MI, 62 sheep were treated with 1 of 5 treatment regimens: no therapy (control, n=12), standard-dose ACEI (sACEI; ramipril 10 mg/d, n=14), high-dose ACEI (hACEI; ramipril 20 mg/d, n=8), AT(1) blockade (losartan 50 mg/d, n=13), and combination therapy with sACEI+AT(1) blockade (CT; ramipril 10 mg/d+losartan 50 mg/d, n=15). MRI was performed before and 8 weeks after MI to quantify changes in LV end-diastolic and end-systolic volume indices (DeltaEDVI, DeltaESVI) and ejection fraction (DeltaEF). Change in regional percent intramyocardial circumferential shortening in noninfarcted segments adjacent to the infarct (Adj Delta%S) was measured by tagged MRI. CT resulted in the most marked blunting of LV remodeling: DeltaESVI (+1.0+/-0.4, +0.7+/-0.4, +0.6+/-0.3, +0.9+/-0.5, and +0.4+/-0.2* mL/kg); DeltaEDVI (+0.9+/-0.4, +0.7+/-0.5, +0.6+/-0.5, +0.9+/-0.5, and +0.4+/-0.3 mL/kg); DeltaEF (-24+/-7, -18+/-6, -14+/-7, -18+/-10, and -11+/-9* %); and Adj Delta%S (-8+/-4, -7+/-3, -5+/-3, -5+/-3, and -2+/-3* %) for Control, sACEI, hACEI, AT(1) blockade, and CT, respectively (*P<0.04 versus sACEI, AT(1) blockade, and control; P<0.05 versus control; P<0.002 versus AT(1) blockade and control). EDVI and ESVI at 8 weeks after MI were smallest with CT (P<0.02 versus all). CONCLUSIONS: Combination therapy with sACEI+AT(1) blockade shows promise in attenuating postinfarction LV remodeling but was not clearly superior to hACEI in the present study.
Assuntos
Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/fisiopatologia , Remodelação Ventricular/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Quimioterapia Combinada , Eletrocardiografia , Feminino , Processamento de Imagem Assistida por Computador , Losartan/farmacologia , Imagem Cinética por Ressonância Magnética , Infarto do Miocárdio/diagnóstico , Miocárdio/metabolismo , Miocárdio/patologia , Ramipril/farmacologia , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Ovinos , Volume Sistólico/efeitos dos fármacos , Sístole , Função Ventricular Esquerda/efeitos dos fármacos , Remodelação Ventricular/fisiologiaRESUMO
OBJECTIVE: We investigated associations between atherosclerosis risk factors (smoking behavior, serum cholesterol, hypertension, body mass index, and functional capacity) and psychological characteristics with suspected linkages to coronary disease (depression, hostility, and anger expression) in an exclusively female cohort. METHODS: Six hundred eighty-eight middle-aged women with chest pain warranting clinical investigation completed a comprehensive diagnostic protocol that included quantitative coronary angiography to assess coronary artery disease (CAD). Primary analyses controlled for menopausal status, age, and socioeconomic status variables (income and education). RESULTS: High depression scores were associated with a nearly three-fold risk of smoking (odds ratio (OR) = 2.8, 95% confidence interval (CI) = 1.4-5.7) after covariate adjustment, and women reporting higher depression symptoms were approximately four times more likely to describe themselves in the lowest category of functional capacity (OR = 3.7, 95% CI = 1.7-7.8). High anger-out scores were associated with a four-fold or greater risk of low high-density lipoprotein cholesterol concentration (<50 mg/dl; OR = 4.0, 95% CI = 1.4-11.1) and high low-density lipoprotein cholesterol concentration (>160 mg/dl; OR = 4.8, 95% CI = 1.5-15.7) and a larger body mass index (OR = 3.5, 95% CI = 1.1-10.8) after covariate adjustment. CONCLUSIONS: These results demonstrate consistent and clinically relevant relationships between psychosocial factors and atherosclerosis risk factors among women and may aid our understanding of the increased mortality risk among women reporting high levels of psychological distress.
Assuntos
Ira , Arteriosclerose/psicologia , Depressão , Emoções Manifestas , Hostilidade , Idoso , Análise de Variância , Arteriosclerose/sangue , Arteriosclerose/etiologia , Arteriosclerose/fisiopatologia , Dor no Peito/psicologia , Colesterol/sangue , Fatores de Confusão Epidemiológicos , Feminino , Humanos , Hipertensão/complicações , Modelos Logísticos , Pulmão/fisiopatologia , Pessoa de Meia-Idade , Isquemia Miocárdica/complicações , Razão de Chances , Fatores de Risco , Fumar/efeitos adversosRESUMO
BACKGROUND: Chest pain in the absence of obstructive coronary artery disease (CAD) is common in women; it is frequently associated with debilitating symptoms and repeated evaluations and may be caused by coronary microvascular dysfunction. However, the prevalence and determinants of microvascular dysfunction in these women are uncertain. METHODS: We measured coronary flow velocity reserve (coronary velocity response to intracoronary adenosine) to evaluate the coronary microvasculature and risk factors for atherosclerosis in 159 women (mean age, 52.9 years) with chest pain and no obstructive CAD. All women were referred for coronary angiography to evaluate their chest pain as part of the Women's Ischemia Syndrome Evaluation (WISE) study. RESULTS: Seventy-four (47%) women had subnormal (<2.5) coronary flow velocity reserve suggestive of microvascular dysfunction (mean, 2.02 +/- 0.38); 85 (53%) had normal reserve (mean, 3.13 +/- 0.64). Demographic characteristics, blood pressure, ventricular function, lipid levels, and reproductive hormone levels were not significantly different between women with normal and those with abnormal microvascular function. Postmenopausal hormone use within 3 months was significantly less prevalent among those with microvascular dysfunction (40% vs 60%, P =.032). Age and number of years past menopause correlated with flow velocity reserve (r = -0.18, P =.02, and r = -0.30, P <.001, respectively). No significant associations were identified between flow velocity reserve and lipid and hormone levels, blood pressure, and left ventricular ejection fraction. CONCLUSIONS: Coronary microvascular dysfunction is present in approximately one half of women with chest pain in the absence of obstructive CAD and cannot be predicted by risk factors for atherosclerosis and hormone levels. Therefore, the diagnosis of coronary microvascular dysfunction should be considered in women with chest pain not attributable to obstructive CAD.
Assuntos
Dor no Peito/fisiopatologia , Circulação Coronária , Vasos Coronários/fisiopatologia , Velocidade do Fluxo Sanguíneo , Cateterismo Cardíaco , Cardiotônicos , Dor no Peito/sangue , Dor no Peito/diagnóstico , Dor no Peito/epidemiologia , Colesterol/sangue , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/etiologia , Diagnóstico Diferencial , Dobutamina , Ecocardiografia , Feminino , Hormônios Esteroides Gonadais/sangue , Terapia de Reposição Hormonal/efeitos adversos , Humanos , Microcirculação/fisiopatologia , Pós-Menopausa/sangue , Prevalência , Fatores de RiscoRESUMO
The purpose of this study is to provide a contemporary qualitative and quantitative analysis of coronary angiograms from a large series of women enrolled in the Women's Ischemia Syndrome Evaluation (WISE) study who had suspected ischemic chest pain. Previous studies have suggested that women with chest pain have a lower prevalence of significant coronary artery disease (CAD) compared with men. Detailed analyses of angiographic findings relative to risk factors and outcomes are not available. All coronary angiograms were reviewed in a central core laboratory. Quantitative measurement of percent stenosis was used to assess the presence and severity of disease. Of the 323 women enrolled in the pilot phase, 34% had no detectable, 23% had measurable but minimal, and 43% had significant ( > 50% diameter stenosis) CAD. Of those with significant CAD, most had multivessel disease. Features suggesting complex plaque were identified in < 10%. Age, hypertension, diabetes mellitus, prior myocardial infarction (MI), current hormone replacement therapy, and unstable angina were all significant, independent predictors of presence of significant disease (p < 0.05). Subsequent hospitalization for a cardiac cause occurred more frequently in those women with minimal and significant disease compared with no disease (p = 0.001). The common findings of no and extensive CAD among symptomatic women at coronary angiography highlight the need for better clinical noninvasive evaluations for ischemia. Women with minimal CAD have intermediate rates of rehospitalization and cardiovascular events, and thus should not be considered low risk.
Assuntos
Angiografia Coronária , Isquemia Miocárdica/diagnóstico , Adulto , Dor no Peito/diagnóstico , Colesterol/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Isquemia Miocárdica/classificação , Isquemia Miocárdica/etiologia , Projetos Piloto , Valor Preditivo dos Testes , Prevalência , Índice de Gravidade de Doença , Fumar/efeitos adversosRESUMO
Calorimetric data can provide a basis for determining potential hazards in reactions, storage, and transportation of process chemicals. This work provides calorimetric data for the thermal decomposition behavior in air of 50wt.% hydroxylamine/water (HA), both with and without added stabilizers, which was measured in closed cells with an automatic pressure tracking adiabatic calorimeter (APTAC). Among the data provided are onset temperatures, reaction order, activation energies, pressures of noncondensable products, thermal stability at 100 degrees C, and the effect of HA storage time. Discussed also are the catalytic effects of carbon steel, stainless steel, stainless steel with silica coating, inconel, titanium, and titanium with silica coating on the reaction self-heat rates and onset temperatures. In borosilicate glass cells, HA was relatively stable at temperatures up to 133 degrees C, where the HA decomposition self-heat rate reached 0.05 degrees C/min. The added stabilizers appeared to reduce HA decomposition rates in glass cells and at ambient temperatures. The tested metals and metal surfaces coated with silica acted as catalysts to lower the onset temperatures and increase the self-heat rates.