Hemorrhagic transformation in patients with large-artery atherosclerotic stroke is associated with the gut microbiota and lipopolysaccharide

Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases mortality.Disruption of the gut microbiota is an important feature of stroke,and some specific bacteria and bacterial metabolites may contribute to hemorrhagic transformation pathogenesis.We aimed to investigate the relationship between the gut microbiota and hemorrhagic transformation in largearte ry atheroscle rotic stro ke.An observational retrospective study was conducted.From May 2020 to September 2021,blood and fecal samples were obtained upon admission from 32 patients with first-ever acute ischemic stroke and not undergoing intravenous thrombolysis or endovascular thrombectomy,as well as 16 healthy controls.Patients with stro ke who developed hemorrhagic transfo rmation(n=15)were compared to those who did not develop hemorrhagic transformation(n=17)and with healthy controls.The gut microbiota was assessed through 16S ribosomal ribonucleic acid sequencing.We also examined key components of the lipopolysaccharide pathway:lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.We observed that bacterial diversity was decreased in both the hemorrhagic transformation and non-hemorrhagic transfo rmation group compared with the healthy controls.The patients with ischemic stro ke who developed hemorrhagic transfo rmation exhibited altered gut micro biota composition,in particular an increase in the relative abundance and dive rsity of members belonging to the Enterobacteriaceae family.Plasma lipopolysaccharide and lipopolysaccharide-binding protein levels were higher in the hemorrhagic transformation group compared with the non-hemorrhagic transfo rmation group.lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14 concentrations were associated with increased abundance of Enterobacte riaceae.Next,the role of the gut microbiota in hemorrhagic transformation was evaluated using an experimental stroke rat model.In this model,transplantation of the gut microbiota from hemorrhagic transformation rats into the recipient rats triggered higher plasma levels of lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.Ta ken togethe r,our findings demonstrate a noticeable change in the gut microbiota and lipopolysaccharide-related inflammatory response in stroke patients with hemorrhagic transformation.This suggests that maintaining a balanced gut microbiota may be an important factor in preventing hemorrhagic transfo rmation after stro ke.

Platelet-to-neutrophil ratio predicts hemorrhagic transformation and unfavorable outcomes in acute ischemic stroke with intravenous thrombolysis

BACKGROUND Acute ischemic stroke(AIS)retains a notable stance in global disease burden,with thrombolysis via recombinant tissue plasminogen activator(rtPA)serving as a viable management approach,albeit with variable outcomes and the potential for complications like hemorrhagic transformation(HT).The platelet-to-neutrophil ratio(P/NR)has been considered for its potential prognostic value in AIS,yet its capacity to predict outcomes following rtPA administration demands further exploration.AIM To elucidate the prognostic utility of P/NR in predicting HT and clinical outcomes following intravenous rtPA administration in AIS patients.METHODS Data from 418 AIS patients treated with intravenous rtPA at Thammasat University Hospital from January 2018 to June 2021 were retrospectively analyzed.The relationship between P/NR and clinical outcomes[early neurological deterioration(E-ND),HT,delayed ND(D-ND),and 3-mo outcomes]was scrutinized.RESULTS Notable variables,such as age,diabetes,and stroke history,exhibited statistical disparities when comparing patients with and without E-ND,HT,D-ND,and 3-mo outcomes.P/NR prognostication revealed an optimal cutoff of 43.4 with a 60.3%sensitivity and a 52.5%specificity for 90-d outcomes.P/NR prognostic accuracy was statistically significant for 90-d outcomes[area under the curve(AUC)=0.562],D-ND(AUC=0.584),and HT(AUC=0.607).CONCLUSION P/NR demonstrated an association with adverse 3-mo clinical outcomes,HT,and D-ND in AIS patients post-rtPA administration,indicating its potential as a predictive tool for complications and prognoses.This infers that a diminished P/NR may serve as a novel prognostic indicator,assisting clinicians in identifying AIS patients at elevated risk for unfavorable outcomes following rtPA therapy.

Advances in the Mechanisms of Hemorrhagic Transformation and Therapeutic Agents after Intravenous Thrombolysis in Ischemic Stroke

Ischemic stroke is an important disease leading to death and disability for all human beings, and the key to its treatment lies in the early opening of obstructed vessels and restoration of perfusion to the local infarcted area. Intravenous thrombolysis with tissue plasminogen activator (tPA) is one of the effective therapies to achieve revascularization, but it faces strict indications with a narrow therapeutic time window, and significantly increases the incidence of hemorrhagic transformation, HT, after reperfusion of the infarcted foci, which greatly reduces the incidence of patients with ischemic stroke. which significantly increases the incidence of hemorrhagic transformation (HT) after reperfusion of the infarcted focus, greatly reducing patient utilization and clinical benefit. Since the mechanism of HT has not been fully elucidated, and the related molecular mechanisms are complex and interactive, there is no specific and effective therapy to avoid the occurrence of HT. In this article, we focus on the research progress on the mechanism of HT after tPA intravenous thrombolysis in ischemic stroke patients from the aspects of vascular integrity disruption, oxidative stress, and neuroinflammatory response and the corresponding therapeutic strategies, in order to improve the safety and prognosis of tPA intravenous thrombolysis in the clinic.

Influences of blood lipids on the occurrence and prognosis of hemorrhagic transformation after acute cerebral infarction: a case-control study of 732 patients

Background: To study the influence of blood lipid levels on hemorrhagic transformation(HT) and prognosis after acute cerebral infarction(ACI).Methods: Patients with ACI within 72 h of symptoms onset between January 1 st, 2015, and December 31 st, 2016, were retrospectively analyzed. Patients were divided into group A(without HT) and group B(HT). The outcomes were assessed after 3 months of disease onset using the modified Rankin Scale(m RS). An m RS score of 0–2 points indicated excellent prognosis, and an m RS score of 3–6 points indicated poor prognosis.Results: A total of 732 patients conformed to the inclusion criteria, including 628 in group A and 104 in group B. The incidence of HT was 14.2%, and the median onset time was 2 d(interquartile range, 1–7 d). The percentages of patients with large infarct size and cortex involvement in group B were 80.8% and 79.8%, respectively, which were both significantly higher than those in group A(28.7 and 33.4%, respectively). The incidence rate of atrial fibrillation(AF) in group B was significantly higher than that in group A(39.4% vs. 13.9%, P<0.001). The adjusted multivariate analysis results showed that large infarct size, cortex involvement and AF were independent risk factors of HT, while total cholesterol(TC) was a protective factor of HT(OR=0.359, 95% CI 0.136–0.944, P=0.038). With every 1 mmol/L reduction in normal TC levels, the risk of HT increased by 64.1%. The mortality and morbidity at 3 months in group B(21.2% and 76.7%, respectively) were both significantly higher than those in group A(8.0% and 42.8%, respectively). The adjusted multivariate analysis results showed that large infarct size(OR=12.178, 95% CI 5.390–27.516, P<0.001) was an independent risk factor of long-term unfavorable outcomes, whereas low-density lipoprotein cholesterol(LDL-C) was a protective factor(OR=0.538, 95% CI 0.300–0.964, P=0.037). With every 1 mmol/L reduction in normal LDL-C levels, the risk of an unfavorable outcome increased by 46.2%. Major therapies, including intravenous recombinant human tissue plasminogen activator(r TPA), intensive lipid-lowering statins and anti-platelets, were not significantly related to either HT or long-term, post-ACI poor prognosis.Conclusions: For patients with large infarct sizes, especially those with cortex involvement, AF, or lower levels of TC, the risk of HT might increase after ACI. The risk of a long-term unfavorable outcome in these patients might increase with a reduction in LDL-C.

Hemorrhagic transformation of ischemic cerebral proliferative angiopathy: A case report

BACKGROUND Cerebral proliferative angiopathy(CPA)is a rare vascular disease characterized by the presence of diffuse vascular proliferation,progressive vascular hyperflow and vasodilation of multiple vessels in the normal brain parenchyma.Unlike cerebral arteriovenous malformations,CPA has a mixed appearance between that of lesions with cell proliferation and endothelial proliferation.To date,the pathogenesis of CPA is unclear,in which changes induced by cortical ischemia in the elastic layer of the blood supply artery and smooth muscle cells may be involved.CASE SUMMARY In this article,we retrospectively analyzed a case of hemorrhagic transformation of ischemic CPA diagnosed by digital subtraction angiography and reviewed the related literature for further exploration of its pathogenesis,diagnosis and treatment.CONCLUSION The information in the present case report may facilitate further clinical research on this cerebrovascular disease.

Hemorrhagic transformation after acute ischemic stroke caused by polycythemia vera:Report of two case

BACKGROUNDPolycythemia vera (PV) is a chronic myeloproliferative disorder characterized byan increase in red blood cells in the peripheral blood. Previous work has reportedthe occurrence of thrombosis or hemorrhage arising in the cerebral vasculaturesecondary to PV. However, hemorrhagic transformation after PV-associated acuteischemic stroke has not been previously described.CASE SUMMARYWe herein present two cases of PV where hemorrhagic transformation occurredafter an acute ischemic stroke. Case 1 was a 57-year-old woman with a history ofhypertension who was admitted for left-sided weakness. Case 2 was a 68-year-oldman who was admitted for a 10-d sudden left arm weakness. Imaging examinationsfor the two patients revealed hemorrhagic transformation after acuteischemic stroke. Both patients had JAK-2-V617F mutation and receivedantiplatelet therapy. Both of them had a good prognosis during the follow-up.CONCLUSIONThis report suggested that hemorrhagic transformation may occur in acuteischemic stroke caused by PV. Antiplatelet drugs do not seem to influence thelong-term outcomes in such patients. Future research should focus on establishinga standard antiplatelet treatment strategy for this condition.

Study on risk factors of hemorrhagic transformation in patients with acute cerebral infarction after non thrombolysis

Objective:To study the risk factors of hemorrhagic transformation in patients with acute cerebral infarction and to analyze the risk factors.Methods: A total of 96 patients with acute cerebral infarction after the thrombolysis in our hospital from June 2016 to December 2017 were selected as the research object. And they were divided into bleeding group 48 cases and hemorrhage transformation group 48 cases according to whether with hemorrhage occurs transformation. Then the lipid metabolism, atrial fibrillation, history of smoking and drinking, history of hypertension and diabetes, blood pressure, treatment time after onset and infarction area of two groups were compared, and the relationship between those factors and the disease were analyzed by the multi-factor Logistic regression analysis.Results: The atrial fibrillation, history of smoking and drinking of two groups had significant differences;The hospital fasting plasma glucose and LDL-C level of two groups had significant differences;the treatment time after onset and infarction area of two groups had significant differences;The multi-factor Logistic regression analysis showed that atrial fibrillation, blood glucose on admission, LDL-C and large area of infarction are the factors affecting the risk of bleeding in patients with acute cerebral infarction transformation.Conclusion:Atrial fibrillation, blood glucose on admission, LDL-C, treatment time after onset and large area of infarction belongs to the patients with acute cerebral infarction after the thrombolysis transformation of bleeding risk factors.

血清ESM-1、E-cad对ACI-LAA溶栓后HT的预测价值

目的 探讨血清内皮细胞特异性分子-1 (ESM-1)、E-钙黏连蛋白(E-cad)对大动脉粥样硬化型脑梗死(ACI-LAA)溶栓后出血转化(HT)的预测价值。方法 选取2020年1月至2022年12月新疆医科大学第一附属医院收治的110例ACI-LAA患者,根据是否发生HT分为HT组和non-HT组。对比两组基础资料及血清ESM-1、E-cad水平。采用ROC曲线分析ESM-1、E-cad预测ACI-LAA患者发生HT的价值。结果 HT组患者NIHSS评分高于non-HT组,梗死面积大于non-HT组(P <0.05),HT组患者血清ESM-1、E-cad水平也高于non-HT组(P<0.05)。Logistic回归分析显示,梗死面积大、NIHSS评分高、血清ESM-1和E-cad水平升高是ACI-LAA患者发生HT的危险因素(P<0.05)。ESM-1联合E-cad预测ACI-LAA患者发生HT的曲线下面积为0.859,预测灵敏度为84.6%,特异度为72.6%。结论 血清ESM-1和E-cad水平与ACI-LAA患者HT密切相关,可作为早期预测发生HT的参考指标。

Effect of Hypertonic Versus Isotonic Saline Resuscitation on Heme Oxygenase-1 Expression in Visceral Organs Following Hemorrhagic Shock in Rats

To compare the early effects of hypertonic and isotonic saline resuscitation on heme oxygenase-1 （HO-1） expression in organs of rats with hemorrhagic shock. Rats were randomly divided into hypertonic saline resuscitation （HTS）, normal saline resuscitation （NS） and sham groups. HO-1 mRNA, protein expression and apoptosis were evaluated in organs. In the HTS group, significant difference was noted in HO-1 protein in small intestinal mucosa and liver compared with the NS and sham groups, and in HO-1 mRNA in liver and kidney compared with the sham group. The apoptosis of small intestinal mucosa, liver, heart, and lung was significantly lower in the HTS group than that in the NS group. In this study, small volume resuscitation with HTS can efficiently up-regulate the expression level of HO-1 in small intestinal mucosa and liver, which may be one of the mechanisms alleviating organ damage.

基于CEEMDAN-HT的永磁同步电机匝间短路振动信号故障特征提取研究

由于长时间处于高负荷运行状态,永磁同步电机(permanent magnet synchronous motor, PMSM)定子绕组线圈匝与匝之间的绝缘性能容易降低,导致出现匝间短路,此时电机的振动强度会发生改变。针对此现象,提出将自适应噪声完备经验模态分解(complete ensemble empirical mode decomposition with adaptive noise, CEEMDAN)与希尔伯特变换(Hilbert transform, HT)结合,构成一种CEEMDAN-HT非线性信号分析方法,并将其应用于提取振动信号故障特征。首先,利用CEEMDAN算法分解振动信号,得到一系列本征模态函数(intrinsic mode function, IMF),并将主元分析中的方差贡献率用于识别包含故障特征信息的IMF。其次,使用HT对方差贡献率较高的IMF进行分析,并以三维联合时频图呈现时间、瞬时频率与幅值,得到了主要故障特征。最后,使用ANSYS有限元软件建立了电机短路故障模型,并搭建了短路故障试验平台,通过对比有限元仿真结果与试验结果,对提出的方法进行了有效性和准确性验证。

Determination of Instantaneous Frequencies of Low Plasma Waves in the Magnetosheath Using Empirical Mode Decomposition (EMD) and Hilbert Transform (HT)

The observations of in-situ spacecraft mission in the magnetosheath and a region of thermalized subsonic plasma behind the bow shock reveal a non-linear behaviour of plasma waves. The study of waves and optics in Physics has given the understanding of the effect of many waves coming together to form a wave field or wave packet. The common aspect of such study shows that two or more waves can superimpose constructively or destructively. The sudden high magnetic field data in the magnetosheath displays such possibility of superposition of waves. In this paper, we use the empirical mode decomposition (EMD) and Hilbert transform (HT) techniques to determine the instantaneous frequencies of low frequency plasma waves in the magnetosheath. Our analysis has shown that the turbulent behavior of magnetic field in the magnetosheath within the selected period is due to superposition of waves.

Development of HTS Transformers and a 10 kVA HTS Transformer Prototype Design

With the improvement of high temperature superconductor （HTS） practical performance, research and development concerning the applications of HTS transformers have been progressed actively worldwide. This paper provides a comprehensive summary on various HTS transformers, and studies the design of a single-phase 10 kVA （220V/24V） HTS transformer prototype to verify HTS for practical transformer applications.

基于EMD和HT的旋转机械振动信号时频分析

把一列时间序列数据通过经验模态分解 (Em pirical Mode Decomposition,简称 EMD)成本征模函数组(Intrinsic Mode Function,简称 IMF) ,然后经希尔伯特变换 (Hilbert Transform ation,简称 HT)获得频谱的信号时频分析新方法引入到旋转机械振动信号处理领域。介绍了该方法的理论和算法。首先 ,采用调频调幅仿真信号对该方法进行仿真验证 ;其次 ,把一实测的旋转机械油膜涡动故障振动信号进行了基于 EMD和 HT的时频分析。仿真和实测信号的分析结果说明 ,用基于 EMD和

旋转机械振动信号基于EMD的HT和STFT时频分析比较

基于经验模态分解(EmpiricalModeDecomposition,EMD)的希尔伯特变换(HilbertTransformation,HT),是先把一列时间序列数据通过经验模态分解,然后经过希尔伯特变换获得频谱的信号处理新方法。介绍了该方法的理论和算法。对仿真和旋转机械油膜涡动故障振动信号分别用基于EMD的HT和基于STFT(Short-TimeFourierTransforma tion,STFT)的时频分析进行了比较研究,研究结果说明,用基于EMD的HT方法对旋转机械的振动信号进行时频分析比STFT有效。

基于EMD和HT时频分析方法的滚动轴承故障诊断

针对滚动轴承故障信号的非线性非平稳特征,提出一种基于EMD和HT的时频分析方法。首先对滚动轴承振动信号进行经验模态分解,然后对分解后的固有模态函数分量作希尔波特变换,得到各分量的时频图,清晰直观地显示出信号的时频分布,从而比较方便地从混有背景信号和噪声的振动信号中提取轴承故障信息。通过现场应用,证明了该方法的有效性。

尖吻蝮蛇蛇毒出血毒素DaHT-3的纯化与性质

被尖吻蝮蛇咬伤会引起严重的出血,对蛇毒出血毒素的研究有利于治疗蛇伤出血药物的筛选.通过SephadexG-75,DEAE-SephadexA-50,SephadexG-200和两次PBE聚焦层析,从尖吻蝮蛇(Dienagkistrodonacutus)蛇毒中纯化到一个分子量为56000的出血毒素(DaHT-3),经氨基酸组成测定计算,由487个氨基酸残基组成.此成分在SDS-PAGE上显示出一条均一的蛋白染色带,用等电聚焦电泳测定,其pI为5.50.该出血成分的最小出血剂量是2.6μg,具有蛋白水解酶活力,其活力为3.68,但没有精氨酸酯酶和磷脂酶A2活力.用红外光谱仪研究DaHT-3在溶液中酰胺I带的吸收谱,该毒素含有31.8%的α螺旋、56.1%的β折叠和12.1%的转角;当加入EDTA螯合剂去除金属离子后,它们的α螺旋、β折叠、转角和无规卷曲分别变为11%、26.4%、46.2%和16.5%,而出血活力和蛋白水解酶活力均丧失。

旋转机械振动信号基于EMD的HT和Winger分布时频分析比较

基于经验模态分解(EmpiricalModeDecomposition,EMD)的希尔伯特变换(HilbertTransformation,HT),是先把一列时间序列数据通过经验模态分解,然后经过希尔伯特变换获得频谱的信号处理新方法。介绍了该方法的理论和算法。对仿真和旋转机械油膜涡动故障振动信号分别用基于EMD的HT和Winger分布的时频分析进行了比较研究,研究结果说明,用基于EMD的HT方法对旋转机械的振动信号进行时频分析比Winger分布分析有效。

基于HT的多条直线检测的特点及其算法改进

依据霍夫(Hough)变换原理,给出了多条直线检测的算法,分析了基于霍夫变换(HT)检测多条直线的特点,即直线—峰值对应性,检测直线不确定性(针对斜率大于0的情况),累加器A的值与待测直线段长度的关系,带噪声多条准直线的参数空间峰值特征,倾角为90°的直线段参数空间峰值特征,并有针对性的提出了改进方法。提出了依据峰值自动搜索填充范围的算法,实现了峰值的搜索,并通过马铃薯作物的行检测验证了该方法的有效性。

基于分形与改进的SPIHT算法的图像压缩方法

为了避免分形编码所固有的方块效应,进一步提高图像编码的工作效率和重构图像的质量,对分形编码和小波零树编码进行优化组合,提出一种分形与改进的SPIHT算法相结合的图像压缩方法。基本方法是,对小波分解后的低频子带进行基于信息熵的快速分形编码,以减少编码时间;对包含图像细节边缘信息的高频子带进行改进的SPIHT编码,以舍去算法中对显著系数的排序扫描过程,减少算法的复杂度,同时提高重构图像的峰值信噪比。实验表明,相对于经典分形编码和小波域内的分形编码,该方法在相同压缩比下,提高了编码效率和重构图像的质量,是一种高效快速的编码方法。

一种基于HT系数预测的遥感图像多分辨融合方法

信息融合的概念自 70年代形成后 ,由于其强调应用对象结果的信息优化 ,在许多方面比传统的信息处理方法有更大的优势 ,在遥感领域得到了广泛的应用。本文在分析前人算法的基础上 ,揭示了高斯拉普拉斯金字塔 ( GLP)结构融合方法与传统的哈达玛变换 ( HT)之间的内在联系 ,提出了一种基于 HT系数预测的多分辨融合方法。通过实验表明 ,这一算法对于光谱差异较大的遥感图像的融合 ,在几何分辨率改善的同时可获得较好的光谱保真度。