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RATIONALE: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors enable an additional 54-75% reduction in low-density lipoprotein cholesterol (LDL-C) in statin-treated patients, demonstrating plaque regression in coronary artery disease. However, the impact of achieving an extremely low level of LDL-C with PCSK9 inhibitors (e.g. Evolocumab) on symptomatic intracranial atherosclerosis remains unexplored. AIM AND HYPOTHESIS: To determine whether combining Evolocumab and statins achieves a more significant symptomatic intracranial plaque regression than statin therapy alone. SAMPLE SIZE ESTIMATES: With a sample size of 1000 subjects, a two-sided α of 0.05, and 20% lost to follow-up, the study will have 83.3% power to detect the difference in intracranial plaque burden. METHODS AND DESIGN: This is an investigator-initiated multicenter, randomized, open-label, outcome assessor-blinded trial, evaluating the impact of combining Evolocumab and statins on intracranial plaque burden assessed by high-resolution magnetic resonance imaging at baseline in patients undergoing a clinically indicated acute stroke or transient ischemic attack due to intracranial artery stenosis, and after 24 weeks of treatment. Subjects (n = 1000) were randomized 1:1 into two groups to receive either Evolocumab 140 mg every 2 weeks with statin therapy or statin therapy alone. STUDY OUTCOMES: The primary endpoint is the change in intracranial plaque burden assessed by high-resolution magnetic resonance imaging, performed at baseline and at the end of the 24-week treatment period. DISCUSSION: This trial will explore whether more significant intracranial plaque regression is achievable with the treatment of combining Evolocumab and statins, providing information about efficacy and safety data. TRIAL REGISTRATION NUMBER: ChiCTR2300068868; https://www.chictr.org.cn/.
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Background: Chronic Obstructive Pulmonary Disease (COPD), the most prevalent chronic respiratory condition, significantly impairs patients' quality of life. The pivotal element in disease management lies in prevention, underscoring the paramount importance of employing a scientific approach to investigate early prevention strategies for COPD. Methods: This study delved into the causal link between 28 dietary intakes and COPD employing two-sample Mendelian randomization. We primarily utilized the Inverse Variance Weighted (IVW) method as the main outcome, complemented by Weighted Median (WM), MR-Egger method, along with several sensitivity analysis techniques, all accompanied by visual representations. Results: We identified higher odds of COPD following exposure to green beans (OR=1.381, 95% CI=1.119-1.704, P=0.003) and pork intake (OR=2.657, 95% CI=1.203-5.868, P=0.016). In contrast, the odds of developing COPD were lower following exposure to dried fruit (OR=0.481, 95% CI=0.283-0.819, P=0.007), cereal (OR=0.560, 95% CI=0.356-0.880, P=0.012), and whole egg consumption (OR=0.700, 95% CI=0.504-0.972, P=0.033). Conclusion: In light of our study's findings, we anticipate that strategically modifying dietary choices may offer an avenue for early COPD prevention in the future.
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Doença Pulmonar Obstrutiva Crônica , Humanos , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/etiologia , Análise da Randomização Mendeliana , Qualidade de Vida , Gerenciamento Clínico , Ingestão de Alimentos , Estudo de Associação Genômica AmplaRESUMO
INTRODUCTION: The Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED) showed that a low-dose alteplase was safe but not clearly non-inferior to standard-dose alteplase in acute ischemic stroke (AIS). Given the significant cost of this medicine, we undertook a cost-effectiveness analysis to determine the probability that low-dose is cost-effective relative to standard-dose alteplase in China. METHODS: For ENCHANTED participants in China with available health cost data, cost-effectiveness and cost-utility analyses were undertaken in which death or disability (modified Rankin scale scores 2-6) at 90 days and quality-adjusted life-years (QALYs) were used as outcome measures, respectively. There was adherence to standard guidelines for health economic evaluations alongside non-inferiority trials and according to a health-care payer's perspective. The equivalence margin for cost and effectiveness was set at USD 691 and -0.025 QALYs, respectively, for the base-case analysis. Probabilistic sensitivity analyses were used to evaluate the probability of low-dose alteplase being non-inferior. RESULTS: While the mean cost of alteplase was lower in the low-dose group (USD 1,569 vs. USD 2,154 in the standard-dose group), the total cost was USD 56 (95% confidence interval [CI]: -1,000-1,113) higher compared to the standard-dose group due to higher hospitalization costs in the low-dose group. There were 462 (95% CI: 415-509) and 410 (95% CI: 363-457) patients with death or disability per 1,000 patients in the low-dose and standard-dose groups, respectively. The low-dose group had marginally lower (0.008, 95% CI: -0.016-0.001) QALYs compared to their standard-dose counterparts. The low-dose group was found to have an 88% probability of being non-inferior based on cost-effectiveness versus the standard-dose group. CONCLUSIONS: This health economic evaluation alongside the ENCHANTED indicates that the use of low-dose alteplase does not save overall healthcare costs nor lead to a gain in QALYs in the management of Chinese patients with AIS compared to the use of standard dose. There is little justification on economic grounds to shift from standard-of-care thrombolysis in AIS.
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Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Ativador de Plasminogênio Tecidual/efeitos adversos , Análise Custo-Benefício , Fibrinolíticos/efeitos adversos , AVC Isquêmico/tratamento farmacológico , China , Resultado do TratamentoRESUMO
OBJECTIVE: This study aimed to investigate the correlation between the circulating miR-126 regulation pathway and the cerebral collateral circulation (CCC), and to test whether miR-126 could serve as a potential biomarker for CCC formation in patients with intracranial arterial stenosis or occlusion. MATERIAL AND METHODS: This single-centre cross-sectional study enrolled patients who underwent cerebral angiography with severe stenosis (≥70%) or occlusion in at least one major intracranial artery. Collateral degree was graded according to the ASITN/SIR classification. The patients were divided into a good CCC group (grade 3-4) or a poor CCC group (grade 0-2). We investigated the plasma levels of miR-126, VEGF, Spred-1 and PIK3R2 by using qRT-PCR, ELISA and Western blot methods, respectively. In addition, we assessed the correlations of plasma miR-126 with VEGF, Spred-1, PIK3R2 and ASITN/SIR grade using the Spearman correlation test and investigated its predictive power for CCC status by using the receiver operating characteristic curve. RESULTS: A total of 68 patients were enrolled (44 with good CCC and 24 with poor CCC). Data showed that plasma miR-126 and VEGF were significantly higher in the good CCC group than in the poor CCC group. Plasma Spred-1 and PIK3R2 level were lower in the good CCC group than in the poor CCC group. In addition, miR-126 and VEGF were positively correlated with ASITN/SIR (miR-126: R = 0.595, P < 0.01; VEGF: R = 0.595, P < 0.01), whereas Spred-1 and PIK3R2 were negatively correlated with ASITN/SIR (Spred-1: R = -0.817, P < 0.01; PIK3R2: R = -0.513, P=0.01). However, the area under the curve of miR-126 level for CCC status was only 0.328 (95% CI: 0.158-0.498; p = 0.067). CONCLUSIONS: Plasma miR-126 level may be related to better CCC formation, one of the mechanisms that may be explained by upregulation of VEGF and reduction of Spred-1 and PIK3R2 protein expression. However, miR-126 might not be an independent predictor for CCC, given its low predictive value.
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Circulação Colateral , MicroRNAs , Constrição Patológica , Estudos Transversais , Humanos , Curva ROCRESUMO
AIM: To expand our current understanding of the genetic basis of subarachnoid hemorrhage (SAH), and reveal the susceptibility genes in SAH risk. METHODS: We conducted whole-exome sequencing (WES) in a cohort of 196 individuals, including 94 SAH patients and 94 controls, as well as 8 samples that belong to two pedigrees. Systematically examination for rare variations (through direct genotyping) and common variations (through genotyping and imputation) for SAHs were performed in this study. RESULTS: A total of 16,029 single-nucleotide polymorphisms (SNPs) and 108,999 short indels were detected in all samples, and among them, 30 SNPs distributed on 17 genes presented a strong association signal with SAH. Two novel pathogenic gene variants were identified as associated risk loci, including mutation in TPO and PALD1. The statistical analysis for rare, damaging variations in SAHs identified several susceptibility genes which were involved in degradation of the extracellular matrix and transcription factor signal pathways. And 25 putative pathogenic genes for SAH were also identified basic on functional interaction network analysis with the published SAH-associated genes. Additionally, pedigree analysis revealed autosomal dominant inheritance of pathogenic genes. CONCLUSION: Systematical analysis revealed a key role for rare variations in SAH risk and discovered SNPs in new complex loci. Our study expanded the list of candidate genes associated with SAH risk, and will facilitate the investigation of disease-related mechanisms and potential clinical therapies.
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Sequenciamento do Exoma , Loci Gênicos , Predisposição Genética para Doença , Hemorragia Subaracnóidea/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Padrões de Herança/genética , Masculino , Mutação/genética , Linhagem , Polimorfismo de Nucleotídeo Único/genética , Fatores de RiscoRESUMO
OBJECTIVE: To identify a new genetic cause in patients segregating distal hereditary motor neuropathy (dHMN) with an autosomal recessive pattern. METHODS: Whole-exome sequencing was conducted in two siblings and was combined with segregation analysis. Additionally, 83 unrelated dHMN patients with unknown genetic cause were screened. RNA analysis was performed using blood lymphocytes and HEK293 cells transfected with mutant plasmids. Immunohistochemistry and Western blot analysis was applied to the nerve tissue. The enzymatic activities of mutant proteins were measured in the cultured cells to verify the pathogenicity of variants. RESULTS: The clinical features of the patients showed late-onset phenotype of distal motor neuropathy without sensory involvement. We identified that compound heterozygous variants of c.1342C>T and c.2071_2072delGCinsTT in the membrane metalloendopeptidase (MME) gene co-segregated with the phenotype in a dHMN family. In an additional group of 83 patients with dHMN, compound heterozygous variants of c.1416+2T>C and c.2027C>T in MME were identified in one patient. The splice site variant c.1416+2T>C results in skipping of exon 13. The stop variant c.1342C>T induces mRNA degradation via nonsense-mediated mRNA decay. Transcript levels of MME in the lymphocytes showed no significant differences between the patients and controls. We also identified that MME variants were associated with mild decrease in protein expression in the sural nerve and significant impairments of enzymatic activity. INTERPRETATION: Variants in the MME gene were associated with not only a Charcot-Marie-Tooth neuropathy phenotype but also with an autosomal-recessive dHMN phenotype. Loss of function may play a role in the pathogenesis of dHMN.
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Genes Recessivos , Neuropatia Hereditária Motora e Sensorial/genética , Mutação , Neprilisina/genética , Adolescente , Feminino , Células HEK293 , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Adulto JovemRESUMO
The aim of this multicenter study was to demonstrate the distribution pattern of atherosclerotic stenosis and its trend with aging between extracranial and intracranial arteries and its distribution between the anterior and posterior circulations in Chinese patients hospitalized with ischemic stroke. In addition, the risk factors for the distribution pattern were illustrated. From June 2015 to May 2016, 9,346 patients with ischemic stroke from 20 hospitals were enrolled. Carotid artery ultrasonography and transcranial color-coded sonography/transcranial Doppler were used to evaluate the extracranial and intracranial arteries. The distribution pattern of atherosclerotic stenosis and its trend with aging were analyzed. Logistic regression was used to analyze the risk factors for the distribution pattern. Among the 9,346 patients, 2,882 patients (30.8%) had at least one artery with a degree of stenosis ≥50%. Among patients with arterial stenosis, the proportion of patients with intracranial artery stenosis was higher than those with extracranial artery stenosis (52.6% vs. 27.6%), and the proportion of anterior circulation artery stenosis was higher than that in the posterior circulation (52.2% vs.26.2%). With aging, the proportion of intracranial artery stenosis alone decreased; at the same time, the proportion of extracranial artery stenosis and extracranial plus intracranial artery stenosis increased (trend χ2=6.698, P=0.001). Hypertension (OR 1.416, P=0.008) and family history of stroke (OR 1.479, P=0.014) were risk factors for intracranial artery stenosis. Male, aging, and smoking were factors more related to extracranial artery stenosis. Aging (OR 1.022, P<0.001) and hypertension (OR 1.392, P=0.019) were related to posterior circulation artery stenosis. Intracranial arteries and anterior circulation arteries were susceptible to stenosis in Chinese patients with ischemic stroke. However, the distribution pattern of atherosclerotic stenosis was dynamic and varied with aging. Aging and different risk factors contribute to this distribution pattern.
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With the fast development of various techniques, more and more data have been accumulated with the unique properties of large size (tall) and high dimension (wide). The era of big data is coming. How to understand and discover new knowledge from these data has attracted more and more scholars' attention and has become the most important task in data mining. As one of the most important techniques in data mining, clustering analysis, a kind of unsupervised learning, could group a set data into objectives(clusters) that are meaningful, useful, or both. Thus, the technique has played very important role in knowledge discovery in big data. However, when facing the large-sized and high-dimensional data, most of the current clustering methods exhibited poor computational efficiency and high requirement of computational source, which will prevent us from clarifying the intrinsic properties and discovering the new knowledge behind the data. Based on this consideration, we developed a powerful clustering method, called MUFOLD-CL. The principle of the method is to project the data points to the centroid, and then to measure the similarity between any two points by calculating their projections on the centroid. The proposed method could achieve linear time complexity with respect to the sample size. Comparison with K-Means method on very large data showed that our method could produce better accuracy and require less computational time, demonstrating that the MUFOLD-CL can serve as a valuable tool, at least may play a complementary role to other existing methods, for big data clustering. Further comparisons with state-of-the-art clustering methods on smaller datasets showed that our method was fastest and achieved comparable accuracy. For the convenience of most scholars, a free soft package was constructed.
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Big Data , Análise por Conglomerados , Mineração de Dados/métodos , Proteínas/química , Algoritmos , Animais , Biologia Computacional , Computadores , Bases de Dados de Proteínas , Lógica Fuzzy , Humanos , Reprodutibilidade dos Testes , SoftwareRESUMO
INTRODUCTION: The use of multimodal computed tomography imaging (MMCT) in routine clinical assessment of stroke patients improves the identification of patients with large regions of salvageable brain tissue, lower risk for haemorrhagic transformation, or a large vessel occlusion requiring endovascular therapy. AIM: To evaluate the cost-effectiveness of using MMCT compared to usual practice for determining eligibility for reperfusion therapy with alteplase using real world data from the International Stroke Perfusion Imaging Registry (INSPIRE). METHODS: We performed a cost-utility analysis. Mean costs and quality-adjusted life years (QALYs) per patient for two alternative screening protocols were calculated. Protocol 1 represented usual practice, while Protocol 2 reflected treatment targeting using multimodal imaging. Cost-effectiveness was assessed using the net-benefit framework. RESULTS: Protocol 1 had a total mean per patient cost of $2,013 USD and 0.148 QALYs. Protocol 2 had a total mean per patient cost of $1,519 USD and 0.153 QALYs. For a range of willingness-to-pay values, representing implicit thresholds of cost-effectiveness, the lower bound of the incremental net monetary benefit statistic was consistently greater than zero, indicating that MMCT is cost- effective compared to usual practice. The results were most sensitive to variation in the mean number of alteplase vials administered. CONCLUSION: In a healthcare setting where multimodal imaging technologies are available and reimbursed, their use in screening patients presenting with acute stroke to determine eligibility for alteplase treatment is cost-effective given a range of willingness-to-pay thresholds and warrants consideration as an alternative to routine practice.
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Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tecidual/uso terapêutico , Tomografia Computadorizada por Raios X/métodos , Idoso , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Análise Custo-Benefício , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão/métodos , Estudos Prospectivos , Anos de Vida Ajustados por Qualidade de Vida , Sistema de Registros/estatística & dados numéricos , Terapia Trombolítica/economia , Tomografia Computadorizada por Raios X/economiaRESUMO
Background and Purpose: The benefit of thrombolysis in ischemic stroke patients without a visible vessel occlusion still requires investigation. This study tested the hypothesis that non-lacunar stroke patients with no visible vessel occlusion on baseline imaging would have a favorable outcome regardless of treatment with alteplase. Methods: We utilized a prospectively collected registry of ischemic stroke patients [the International Stroke Perfusion Imaging Registry (INSPIRE)] who had baseline computed tomographic perfusion and computed tomographic angiography. The rates of patients achieving modified Rankin Scale (mRS) 0-1 were compared between alteplase treated and untreated patients using logistic regression to generate odds ratios. Results: Of 1569 patients in the INSPIRE registry, 1,277 were eligible for inclusion. Of these, 306 (24%) had no identifiable occlusion and were eligible for alteplase, with 141 (46%) of these patients receiving thrombolysis. The treated and untreated groups had significantly different median baseline National Institutes of Health Stroke Scale (NIHSS) [alteplase 8, interquartile range (IQR) 5-10, untreated 6, IQR 4-8, P < 0.001] and median volume of baseline perfusion lesion [alteplase 5.6 mL, IQR 1.3-17.7 mL, untreated 2.6 mL, IQR 0-6.7 mL, P < 0.001]. After propensity analysis, alteplase treated patients without a vessel occlusion were less likely to have an excellent outcome (mRS 0-1; 56%) than untreated (78.8%, OR, 0.42, 95% confidence interval, 0.24-0.75, P = 0.003). Conclusions: In this non-randomized comparison, alteplase treatment in patients without an identifiable vessel occlusion did not result in higher rates of favorable outcome compared to untreated. However, treated patients displayed less favorable baseline prognostic factors than the untreated group. Further studies may be required to confirm this data.
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See Saver (doi:10.1093/awx020) for a scientific commentary on this article.Stroke shortens an individual's disability-free life. We aimed to assess the relative prognostic influence of pre- and post-treatment perfusion computed tomography imaging variables (e.g. ischaemic core and penumbral volumes) compared to standard clinical predictors (such as onset-to-treatment time) on long-term stroke disability in patients undergoing thrombolysis. We used data from a prospectively collected international, multicentre, observational registry of acute ischaemic stroke patients who had perfusion computed tomography and computed tomography angiography before treatment with intravenous alteplase. Baseline perfusion computed tomography and follow-up magnetic resonance imaging were analysed to derive the baseline penumbra volume, baseline ischaemic core volume, and penumbra salvaged from infarction. The primary outcome measure was the effect of imaging and clinical variables on Disability-Adjusted Life Year. Clinical variables were age, sex, National Institutes of Health Stroke Scale score, and onset-to-treatment time. Age, sex, country, and 3-month modified Rankin Scale were extracted from the registry to calculate disability-adjusted life-year due to stroke, such that 1 year of disability-adjusted life-year equates to 1 year of healthy life lost due to stroke. There were 772 patients receiving alteplase therapy. The number of disability-adjusted life-year days lost per 1 ml of baseline ischaemic core volume was 17.5 (95% confidence interval, 13.2-21.9 days, P < 0.001). For every millilitre of penumbra salvaged, 7.2 days of disability-adjusted life-year days were saved (ß = -7.2, 95% confidence interval, -10.4 to -4.1 days, P < 0.001). Each minute of earlier onset-to-treatment time resulted in a saving of 4.4 disability-free days after stroke (1.3-7.5 days, P = 0.006). However, after adjustment for imaging variables, onset-to-treatment time was not significantly associated with savings in disability-adjusted life-year days. Pretreatment perfusion computed tomography can (independently of clinical variables) predict significant gains, or loss, of disability-free life in patients undergoing reperfusion therapy for stroke. The effect of earlier treatment on disability-free life appears explained by salvage of penumbra, particularly when the ischaemic core is not too large.
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Imagem de Perfusão , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia , Terapia Trombolítica/métodos , Resultado do Tratamento , Idoso , Idoso de 80 Anos ou mais , Circulação Cerebrovascular , Pessoas com Deficiência , Feminino , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Estudos Retrospectivos , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND AND PURPOSE: Advanced imaging to identify tissue pathophysiology may provide more accurate prognostication than the clinical measures used currently in stroke. This study aimed to derive and validate a predictive model for functional outcome based on acute clinical and advanced imaging measures. METHODS: A database of prospectively collected sub-4.5 hour patients with ischemic stroke being assessed for thrombolysis from 5 centers who had computed tomographic perfusion and computed tomographic angiography before a treatment decision was assessed. Individual variable cut points were derived from a classification and regression tree analysis. The optimal cut points for each assessment variable were then used in a backward logic regression to predict modified Rankin scale (mRS) score of 0 to 1 and 5 to 6. The variables remaining in the models were then assessed using a receiver operating characteristic curve analysis. RESULTS: Overall, 1519 patients were included in the study, 635 in the derivation cohort and 884 in the validation cohort. The model was highly accurate at predicting mRS score of 0 to 1 in all patients considered for thrombolysis therapy (area under the curve [AUC] 0.91), those who were treated (AUC 0.88) and those with recanalization (AUC 0.89). Next, the model was highly accurate at predicting mRS score of 5 to 6 in all patients considered for thrombolysis therapy (AUC 0.91), those who were treated (0.89) and those with recanalization (AUC 0.91). The odds ratio of thrombolysed patients who met the model criteria achieving mRS score of 0 to 1 was 17.89 (4.59-36.35, P<0.001) and for mRS score of 5 to 6 was 8.23 (2.57-26.97, P<0.001). CONCLUSIONS: This study has derived and validated a highly accurate model at predicting patient outcome after ischemic stroke.
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Isquemia Encefálica/diagnóstico por imagem , Modelos Neurológicos , Avaliação de Resultados em Cuidados de Saúde/normas , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Estudos de Coortes , Angiografia por Tomografia Computadorizada/métodos , Angiografia por Tomografia Computadorizada/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde/métodos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodosRESUMO
OBJECTIVE: The study aimed to analyze the influencing factors of thrombolysis therapy in acute ischemic stroke patients with onset time less than 4.5 hours. METHODS: We consecutively prospectively screened acute ischemic stroke patients with onset time less than 4.5 hours from emergency department, outpatients and inpatients of neurology department, and image center in our hospital over a 31-month time period (April 2012-November 2014). The rate of thrombolysis and the reasons for not receiving thrombolysis were analyzed. RESULTS: A total of 538 patients who met the inclusion criteria were included (68.2% males, mean age 67±13 years old). Only 104 (19.3%) patients received thrombolysis. The main reasons for the patients not receiving thrombolysis included minor symptoms (172 cases, 39.6%), rapidly improving symptoms and high possibility of transient ischemic attack (TIA) (59 cases, 13.6%), patients or families refusing thrombolysis (44, 10.1%), in-hospital delay (38, 8.8%), elderly people with age over than 80 years old (38, 8.8%). CONCLUSIONS: The thrombolysis rate within time window of acute ischemic stroke is remarkably higher than that of several years ago in China. The main reasons for not receiving thrombolysis are minor and rapidly improving symptoms, patients or families' refusal, in-hospital delay, elderly people with age over than 80 years old.
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Isquemia Encefálica/tratamento farmacológico , Fibrinolíticos/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , China , Serviço Hospitalar de Emergência , Feminino , Humanos , Ataque Isquêmico Transitório , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
INTRODUCTION: Presence of white matter hyperintensity (WMH) on MRI is a marker of cerebral small vessel disease and is associated with increased small vessel stroke and increased risk of hemorrhagic transformation (HT) after thrombolysis. AIM: We sought to determine whether white matter hypoperfusion (WMHP) on perfusion CT (CTP) was related to WMH, and if WMHP predisposed to acute lacunar stroke subtype and HT after thrombolysis. METHODS: Acute ischemic stroke patients within 12 h of symptom onset at 2 centers were prospectively recruited between 2011 and 2013 for the International Stroke Perfusion Imaging Registry. Participants routinely underwent baseline CT imaging, including CTP, and follow-up imaging with MRI at 24 h. RESULTS: Of 229 ischemic stroke patients, 108 were Caucasians and 121 Chinese. In the contralateral white matter, patients with acute lacunar stroke had lower cerebral blood flow (CBF) and cerebral blood volume (CBV), compared to those with other stroke subtypes (P = 0.041). There were 46 patients with HT, and WMHP was associated with increased risk of HT (R(2) = 0.417, P = 0.002). Compared to previously reported predictors of HT, WMHP performed better than infarct core volume (R(2) = 0.341, P = 0.034), very low CBV volume (R(2) = 0.249, P = 0.026), and severely delayed perfusion (Tmax>14 second R(2) = 0.372, P = 0.011). Patients with WMHP also had larger acute infarcts and increased infarct growth compared to those without WMHP (mean 28 mL vs. 13 mL P < 0.001). CONCLUSION: White matter hypoperfusion remote to the acutely ischemic region on CTP is a marker of small vessel disease and was associated with increased HT, larger acute infarct cores, and greater infarct growth.
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Infarto Encefálico/etiologia , Isquemia Encefálica/complicações , Isquemia Encefálica/patologia , Hemorragias Intracranianas/etiologia , Imagem de Perfusão , Substância Branca/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Prospectivos , Estudos Retrospectivos , Acidente Vascular Cerebral/etiologiaRESUMO
Protein structure Quality Assessment (QA) is an essential component in protein structure prediction and analysis. The relationship between protein sequence and structure often serves as a basis for protein structure QA. In this work, we developed a new Hidden Markov Model (HMM) to assess the compatibility of protein sequence and structure for capturing their complex relationship. More specifically, the emission of the HMM consists of protein local structures in angular space, secondary structures, and sequence profiles. This model has two capabilities: (1) encoding local structure of each position by jointly considering sequence and structure information, and (2) assigning a global score to estimate the overall quality of a predicted structure, as well as local scores to assess the quality of specific regions of a structure, which provides useful guidance for targeted structure refinement. We compared the HMM model to state-of-art single structure quality assessment methods OPUSCA, DFIRE, GOAP, and RW in protein structure selection. Computational results showed our new score HMM.Z can achieve better overall selection performance on the benchmark datasets.
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In recent years in silico protein structure prediction reached a level where fully automated servers can generate large pools of near-native structures. However, the identification and further refinement of the best structures from the pool of models remain problematic. To address these issues, we have developed (i) a target-specific selective refinement (SR) protocol; and (ii) molecular dynamics (MD) simulation based ranking (SMDR) method. In SR the all-atom refinement of structures is accomplished via the Rosetta Relax protocol, subject to specific constraints determined by the size and complexity of the target. The best-refined models are selected with SMDR by testing their relative stability against gradual heating through all-atom MD simulations. Through extensive testing we have found that Mufold-MD, our fully automated protein structure prediction server updated with the SR and SMDR modules consistently outperformed its previous versions.
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Conformação Proteica , Proteínas/química , Software , Algoritmos , Biologia Computacional , Simulação de Dinâmica MolecularRESUMO
AIM: To evaluate the early expression of mannose-binding lectin 2 (MBL2) in human corneal epithelial cells (HCECs) infected by Aspergillus fumigatus (AF). METHODS: HCECs cultured in vitro with AF antigens and sampled at 0, 0.5, 1, 2, 4, 6 and 8h. The expression of MBL2 mRNA was evaluated by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). The expression of MBL2 protein in supernatant fluid was shown by enzyme linked immunosorbent assay (ELISA). MBL2 protein in HCECs was detected by immunocytochemistry at 0 and 24h. RESULTS: MBL2 mRNA and protein are expressed in normal HCECs. The expression of MBL2 mRNA and protein in supernatant fluid begin to increase after being stimulated with AF antigens. The most significantly peak of MBL2 mRNA is in 2h. The protein of MBL2 in supernatant fluid decrease gradually after 0.5h. The protein in HCECs expression increase after stimulation of 24h. CONCLUSION: MBL2 receptor expressed in normal HCECs in vitro. The stimulation by AF antigens can increase the early expression of it.
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OBJECTIVE: The prognostic importance of the speed of early hematoma growth in acute intracerebral hemorrhage (ICH) has not been well established. We aimed to determine the association between the rate of increase in hematoma volume and major clinical outcomes in the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT) studies. The effects of early intensive blood pressure (BP) lowering according to the speed of hematoma growth were also investigated. METHODS: Pooled analyses of the INTERACT1 (n = 404) and INTERACT2 (n = 2,839) studies-randomized controlled trials of patients with spontaneous ICH with elevated systolic BP, randomly assigned to intensive (target systolic BP <140 mm Hg) or guideline-based (<180 mm Hg) BP management. The speed of ultraearly hematoma growth (UHG) was defined as hematoma volume (mL)/onset-to-CT time (hours). Primary outcome was death or major disability (modified Rankin Scale score of 3-6) at 90 days. RESULTS: Among a total of 2,909 patients (90%) with information on UHG and outcome, median speed of UHG was 6.2 mL/h. There was a linear association between UHG and outcome: multivariable-adjusted odd ratios 1.90 (95% confidence interval 1.50-2.39) for 5-10 mL/h and 2.96 (2.36-3.71) for >10 mL/h vs the <5 mL/h group. There were no clear differences in the effects of intensive BP lowering according to 3 speeds of UHG on outcome (p = 0.75 for homogeneity). CONCLUSIONS: The speed of UHG in patients with ICH was continuously associated with increased risks of death or major disability, and from lower levels than previously reported (≥5 mL/h). The benefits of intensive BP lowering appear to be independent of the speed of bleeding.
Assuntos
Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/fisiopatologia , Hematoma/diagnóstico , Hematoma/fisiopatologia , Doença Aguda , Idoso , Pressão Sanguínea/fisiologia , Hemorragia Cerebral/patologia , Hemorragia Cerebral/terapia , Feminino , Hematoma/patologia , Hematoma/terapia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Prognóstico , Fatores de Tempo , Resultado do TratamentoRESUMO
X-ray crystallography remains the most dominant method for solving atomic structures. However, for relatively large systems, the availability of only medium-to-low-resolution diffraction data often limits the determination of all-atom details. A new molecular dynamics flexible fitting (MDFF)-based approach, xMDFF, for determining structures from such low-resolution crystallographic data is reported. xMDFF employs a real-space refinement scheme that flexibly fits atomic models into an iteratively updating electron-density map. It addresses significant large-scale deformations of the initial model to fit the low-resolution density, as tested with synthetic low-resolution maps of D-ribose-binding protein. xMDFF has been successfully applied to re-refine six low-resolution protein structures of varying sizes that had already been submitted to the Protein Data Bank. Finally, via systematic refinement of a series of data from 3.6 to 7â Å resolution, xMDFF refinements together with electrophysiology experiments were used to validate the first all-atom structure of the voltage-sensing protein Ci-VSP.
Assuntos
Cristalografia por Raios X/métodos , Simulação de Dinâmica Molecular , Bases de Dados de Proteínas , Proteínas de Escherichia coli/química , Proteínas Periplásmicas de Ligação/químicaRESUMO
BACKGROUND: Protein structure data in Protein Data Bank (PDB) are widely used in studies of protein function and evolution and in protein structure prediction. However, there are two main barriers in large-scale usage of PDB data: 1) PDB data are highly redundant in terms of sequence and structure similarity; and 2) many PDB files have issues due to inconsistency of data and standards as well as missing residues, so that automated retrieval and analysis are often difficult. DESCRIPTION: To address these issues, we have created MUFOLD-DB http://mufold.org/mufolddb.php, a web-based database, to collect and process the weekly PDB files thereby providing users with non-redundant, cleaned and partially-predicted structure data. For each of the non-redundant sequences, we annotate the SCOP domain classification and predict structures of missing regions by loop modelling. In addition, evolutional information, secondary structure, disorder region, and processed three-dimensional structure are computed and visualized to help users better understand the protein. CONCLUSIONS: MUFOLD-DB integrates processed PDB sequence and structure data and multiple computational results, provides a friendly interface for users to retrieve, browse and download these data, and offers several useful functionalities to facilitate users' data operation.