Trimethylamine N-oxide predicts stroke severity in diabetic patients with acute ischaemic stroke and is related to glycemic variability.

BACKGROUND AND PURPOSE: The present study analyzed the relationship between circulating trimethylamine N-oxide (TMAO) levels and stroke severity in diabetic patients with acute ischaemic stroke. A further aim was to investigate whether higher TMAO levels were associated with platelet aggregation and glycemic variability. METHODS: This was a cross-sectional analysis of 108 patients with type 2 diabetes mellitus (DM) undergoing acute ischaemic stroke and 60 healthy controls. Fasting plasma TMAO was measured using high-performance liquid chromatography with online electrospray ionization tandem mass spectrometry. RESULTS: Plasma TMAO levels of patients with acute ischaemic stroke were significantly higher than those of healthy controls. Amongst stroke patients, 50 were defined as undergoing mild stroke, and their plasma TMAO levels were lower compared to those with moderate to severe stroke. Platelet aggregation and mean amplitude of glycemic excursions were both correlated with plasma TMAO levels and these relationships remained significant in multiple linear regression analyses. Moreover, in streptozotocin-induced diabetic rats fed a diet enriched with choline to increase TMAO synthesis, platelet aggregation was significantly increased in the DM + choline and fluctuating DM (FDM) + choline groups compared to the control group. This increase was abolished in rats receiving oral antibiotics, which markedly reduced plasma TMAO levels. Importantly, compared with the DM + choline group, the FDM + choline group displayed significantly elevated TMAO levels and higher platelet aggregation. CONCLUSIONS: Our results demonstrated that higher plasma TMAO levels were associated with stroke severity and suggested a novel link between plasma TMAO levels and glycemic variability in diabetic patients with acute ischaemic stroke.

Modulation of GSK-3ß/ß-Catenin Signaling Contributes to Learning and Memory Impairment in a Rat Model of Depression.

Background: It is widely accepted that cognitive processes, such as learning and memory, are affected in depression, but the molecular mechanisms underlying the interactions of these 2 disorders are not clearly understood. Recently, glycogen synthase kinase-3 beta (GSK-3ß)/ß-catenin signaling was shown to play an important role in the regulation of learning and memory. Methods: The present study used a rat model of depression, chronic unpredictable stress, to determine whether hippocampal GSK-3ß/ß-catenin signaling was involved in learning and memory alterations. Results: Our results demonstrated that chronic unpredictable stress had a dramatic influence on spatial cognitive performance in the Morris water maze task and reduced the phosphorylation of Ser9 of GSK-3ß as well as the total and nuclear levels of ß-catenin in the hippocampus. Inhibition of GSK3ß by SB216763 significantly ameliorated the cognitive deficits induced by chronic unpredictable stress, while overexpression of GSK3ß by AAV-mediated gene transfer significantly decreased cognitive performance in adult rats. In addition, chronic unpredictable stress exposure increased the expression of the canonical Wnt antagonist Dkk-1. Furthermore, chronic administration of corticosterone significantly increased Dkk-1 expression, decreased the phosphorylation of Ser9 of GSK-3ß, and resulted in the impairment of hippocampal learning and memory. Conclusions: Our results indicate that impairment of learning and memory in response to chronic unpredictable stress may be attributed to the dysfunction of GSK-3ß/ß-catenin signaling mediated by increased glucocorticoid signaling via Dkk-1.

The initial glycemic variability is associated with early neurological deterioration in diabetic patients with acute ischemic stroke.

The association between glycemic variability and early neurological deterioration (END) in acute ischemic stroke remains unclear. This study attempted to explore whether initial glycemic variability increases END in diabetic patients with acute ischemic stroke. We enrolled type 2 diabetic patients undergoing acute ischemic stroke from November 2015 to November 2016. A total of 336 patients within 72 h from stroke onset were included. The serum glucose levels were checked four times per day during the initial 3 hospital days. The standard deviation of blood glucose (SDBG) values and the mean amplitude of glycemic excursions (MAGE) were calculated for glycemic variability. END was defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) ≥ 2 points between hospital days 0 and 5. The frequencies of END and HbA1c were significantly different in subjects grouped according to tertiles of MAGE (9.09, 12.07 and 50.00%, p < 0.001 for END; 7.36 ± 1.91, 7.83 ± 1.93 and 8.56 ± 1.79, p < 0.001 for HbA1c). Compared to patients without END, patients with END had significantly higher HbA1c levels (8.30 ± 1.92 vs 7.80 ± 1.93, p = 0.043), increased SDBG (3.42 ± 1.14 vs 2.60 ± 0.96, p < 0.001), and increased MAGE (6.46 ± 2.09 vs 4.59 ± 1.91, p < 0.001). In a multivariable logistic regression, stroke etiology (OR 0.675; 95% CI 0.485-0.940, p = 0.020), baseline NIHSS (OR 1.086; 95% CI 1.004-1.175, p = 0.040), and MAGE (OR 1.479; 95% CI 1.162-1.882, p = 0.001) were significantly associated with END. Initial glycemic variability is associated with END in diabetic patients with acute ischemic stroke.

Epidermal growth factor receptor inhibitor ameliorates excessive astrogliosis and improves the regeneration microenvironment and functional recovery in adult rats following spinal cord injury.

BACKGROUND: Astrogliosis is a common phenomenon after spinal cord injury (SCI). Although this process exerts positive effects on axonal regeneration, excessive astrogliosis imparts negative effects on neuronal repair and recovery. Epidermal growth factor receptor (EGFR) pathway is critical to the regulation of reactive astrogliosis, and therefore is a potential target of therapeutics to better control the response. In this report, we aim to investigate whether blocking EGFR signaling using an EGFR tyrosine kinase specific inhibitor can attenuate reactive astrogliosis and promote functional recovery after a traumatic SCI. METHOD: The astrocyte scratch injury model in vitro and the weight-drop SCI model in vivo were used as model systems. PD168393 was used to inhibit EGFR signaling activation. Astrocytic activation and phosphorylated EGFR (pEGFR) were observed after immunofluorescence staining and Western blot analysis. The rate of proliferation was determined by immunofluorescence detection of BrdU-incorporating cells located next to the wound. The levels of TNF-α, iNOS, COX-2 and IL-1ß in the culture medium under different conditions were assayed by ELISA. Western blot was performed to semi-quantify the expression of EGFR/pEGFR, glial fibrillary acid protein (GFAP) and chondroitin sulfate proteoglycans (CSPGs). Myelin was stained by Luxol Fast Blue Staining. Cresyl violet eosin staining was performed to analyze the lesion cavity volume and neuronal survival following injury. Finally, functional scoring and residual urine recording were performed to show the rats' recovery. RESULTS: EGFR phosphorylation was found to parallel astrocyte activation, and EGFR inhibitor PD168393 potently inhibited scratch-induced reactive astrogliosis and proinflammatory cytokine/mediator secretion of reactive astrocytes in vitro. Moreover, local administration of PD168393 in the injured area suppressed CSPGs production and glial scar formation, and resulted in reduced demyelination and neuronal loss, which correlated with remarkable hindlimb motor function and bladder improvement in SCI rats. CONCLUSIONS: The specific EGFR inhibitor PD168393 can ameliorate excessive reactive astrogliosis and facilitate a more favorable environment for axonal regeneration after SCI. As such, EGFR inhibitor may be a promising therapeutic intervention in CNS injury.

Fluoxetine regulates neurogenesis in vitro through modulation of GSK-3ß/ß-catenin signaling.

BACKGROUND: It is generally accepted that chronic treatment with antidepressants increases hippocampal neurogenesis, but the molecular mechanisms underlying their effects are unknown. Recently, glycogen synthase kinase-3 beta (GSK-3ß)/ß-catenin signaling was shown to be involved in the mechanism of how antidepressants might influence hippocampal neurogenesis. METHODS: The aim of this study was to determine whether GSK-3ß/ß-catenin signaling is involved in the alteration of neurogenesis as a result of treatment with fluoxetine, a selective serotonin reuptake inhibitor. The mechanisms involved in fluoxetine's regulation of GSK-3ß/ß-catenin signaling pathway were also examined. RESULTS: Our results demonstrated that fluoxetine increased the proliferation of embryonic neural precursor cells (NPCs) by up-regulating the phosphorylation of Ser9 on GSK-3ß and increasing the level of nuclear ß-catenin. The overexpression of a stabilized ß-catenin protein (ΔN89 ß-catenin) significantly increased NPC proliferation, while inhibition of ß-catenin expression in NPCs led to a significant decrease in the proliferation and reduced the proliferative effects induced by fluoxetine. The effects of fluoxetine-induced up-regulation of both phosphorylation of Ser9 on GSK-3ß and nuclear ß-catenin were significantly prevented by the 5-hydroxytryptamine-1A (5-HT1A) receptor antagonist WAY-100635. CONCLUSIONS: The results demonstrate that fluoxetine may increase neurogenesis via the GSK-3ß/ß-catenin signaling pathway that links postsynaptic 5-HT1A receptor activation.

Combination of platelet-to-lymphocyte ratio and D-dimer for the identification of cardiogenic cerebral embolism in non-valvular atrial fibrillation.

Background: Non-valvular atrial fibrillation (NVAF) is the most common cause of cardiogenic cerebral embolism (CCE). However, the underlying mechanism between cerebral embolism and NVAF is indefinite, and there is no effective and convenient biomarker to identify potential risk of CCE in patients with NVAF in clinic. The present study aims to identify risk factors for interpreting the potential association of CCE with NVAF and providing valuable biomarkers to predict the risk of CCE for NVAF patients. Methods: 641 NVAF patients diagnosed with CCE and 284 NVAF patients without any history of stroke were recruited in the present study. Clinical data including demographic characteristics, medical history, and clinical assessments, were recorded. Meanwhile, Blood cell counts, lipid profiles, high-sensitivity C-reactive protein, and coagulation function-related indicators were measured. Least absolute shrinkage and selection operator (LASSO) regression analysis was utilized to build a composite indicator model based on the blood risk factors. Results: (1) CCE patients had significantly increased neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio (PLR), and D-dimer levels as compared with patients in the NVAF group, and these three indicators can distinguish CCE patients from ones in the NVAF group with an area under the curve (AUC) value of over 0.750, respectively. (2) Using the LASSO model, a composite indicator, i.e., the risk score, was determined based on PLR and D-dimer and displayed differential power for distinguishing CCE patients from NVAF patients with an AUC value of over 0.934. (3) The risk score was positively correlated with the National Institutes of Health Stroke Scale and CHADS2 scores in CCE patients. (4) There was a significant association between the change value of the risk score and the recurrence time of stroke in initial CCE patients. Conclusions: The PLR and D-dimer represent an aggravated process of inflammation and thrombosis in the occurrence of CCE after NVAF. The combination of these two risk factors can contribute to identifying the risk of CCE for patients with NVAF with an accuracy of 93.4%, and the greater in change of composite indicator, the shorter in the recurrence of CCE for NVAF patients.

Potential Association of Neutrophil Extracellular Traps With Cognitive Impairment in Cerebral Small Vessel Disease.

No acceptable biomarker can facilitate the early identification of cognitive impairment associated with cerebral small vessel disease (CSVD) in the older persons. The neutrophil extracellular traps (NETs) in the inflammation response of circulatory and central systems are essential in destroying the blood-brain barrier. The present study aims to explore the potential associations of plasma NETs with cognitive performance in CSVD. We recruited 146 CSVD patients and 66 healthy controls (HCs), and comprehensive neuropsychological assessments and multimodal magnetic resonance imaging were conducted. Three NETs markers, namely citrullination of histone H3, neutrophil elastase-DNA, and myeloperoxidase (MPO)-DNA, and 4 oxidative stress-related indexes in plasma samples, were measured. The plasma levels of 3 NETs markers were more significantly elevated in CSVD patients than in HCs. Significant correlations of the 3 NETs markers were observed with multiple cognitive domain scores. Furthermore, higher plasma malondialdehyde and NETs levels were significantly associated with the worse Montreal Cognitive Assessment scores among CSVD patients. Moreover, plasma MPO-DNA levels significantly mediated the effect of the amplitude of low-frequency fluctuation value within the bilateral caudate and the scores of global cognitive function, executive function, and information processing speed. Additionally, a panel of 3 NETs markers had the highest area under the curve value to distinguish the cognitively impaired CSVD patients from HCs and nonimpaired ones. Therefore, plasma NETs may be potential biomarkers for early diagnosis of CSVD-related cognitive impairment. Activated lipid peroxidation in circulation and impaired caudate function support potential associations of plasma NETs in cognitively impaired CSVD patients.

Potential of brain age in identifying early cognitive impairment in subcortical small-vessel disease patients.

Background: Reliable and individualized biomarkers are crucial for identifying early cognitive impairment in subcortical small-vessel disease (SSVD) patients. Personalized brain age prediction can effectively reflect cognitive impairment. Thus, the present study aimed to investigate the association of brain age with cognitive function in SSVD patients and assess the potential value of brain age in clinical assessment of SSVD. Materials and methods: A prediction model for brain age using the relevance vector regression algorithm was developed using 35 healthy controls. Subsequently, the prediction model was tested using 51 SSVD patients [24 subjective cognitive impairment (SCI) patients and 27 mild cognitive impairment (MCI) patients] to identify brain age-related imaging features. A support vector machine (SVM)-based classification model was constructed to differentiate MCI from SCI patients. The neurobiological basis of brain age-related imaging features was also investigated based on cognitive assessments and oxidative stress biomarkers. Results: The gray matter volume (GMV) imaging features accurately predicted brain age in individual patients with SSVD (R 2 = 0.535, p < 0.001). The GMV features were primarily distributed across the subcortical system (e.g., thalamus) and dorsal attention network. SSVD patients with age acceleration showed significantly poorer Mini-Mental State Examination and Montreal Cognitive Assessment (MoCA) scores. The classification model based on GMV features could accurately distinguish MCI patients from SCI patients (area under the curve = 0.883). The classification outputs of the classification model exhibited significant associations with MoCA scores, Trail Making Tests A and B scores, Stroop Color and Word Test C scores, information processing speed total scores, and plasma levels of total antioxidant capacity in SSVD patients. Conclusion: Brain age can be accurately quantified using GMV imaging data and shows potential clinical value for identifying early cognitive impairment in SSVD patients.

Fluid-Attenuated Inversion Recovery Vascular Hyperintensity as a Potential Predictor for the Prognosis of Acute Stroke Patients After Intravenous Thrombolysis.

BACKGROUND: Fluid-attenuated inversion recovery vascular hyperintensity (FVH) can reflect the collateral status, which may be a valuable indicator to predict the functional outcome of acute stroke (AS) patients. METHODS: A total of 190 AS patients with large vessel occlusion (LVO) were retrospectively investigated. All patients completed a 6-month follow-up and their modified Rankin Scale (mRS) scores were recorded at 1, 3, and 6 months after intravenous thrombolysis (IVT). Based on their mRS at 3 months, patients were divided into two groups: poor prognosis (131 patients; 68.9% of all subjects) and favorable prognosis (59 patients; 31.1% of all subjects). The death records of 28 patients were also analyzed in the poor prognosis group. RESULTS: (1) Univariate and multivariate analyses showed that the higher National Institutes of Health Stroke Scale (NIHSS) score at admission, higher fasting blood glucose, and lower FVH score were independent risk factors to predict the poor prognosis of IVT. (2) Survival analysis indicated that FVH score was the only baseline factor to predict the 6-month survival after IVT. (3) Baseline FVH score had great prediction performance for the prognosis of IVT (area under the curve = 0.853). (4) Baseline FVH score were negatively correlated with the NIHSS score at discharge and mRS score at 1, 3, and 6 months. CONCLUSION: Among various baseline clinical factors, only the FVH score might have implications for 3-month outcome and 6-month survival of AS patients after IVT. Baseline FVH score showed great potential to predict the prognosis of the AS patients.

Effects of Ultrasonic Bending Vibration Introduced by an L-Shaped Ultrasonic Rod on the Microstructure and Properties of a 1060 Aluminum Alloy Strip Formed by Twin-Roll Casting.

In order to achieve the industrial application of ultrasonic energy in the continuous casting and rolling production of aluminum alloy, a new type of L-shaped ultrasonic rod was used to introduce an ultrasonic bending vibration into the aluminum melt in the launder during the horizontal twin-roll continuous casting and rolling process of a 1060 aluminum alloy. The effects of the ultrasonic bending vibration on the microstructure and properties of the 1060 aluminum alloy cast rolling strip and its subsequent cold rolling strip were studied experimentally, and the effect of the ultrasonic-assisted refining with different amounts of Al-Ti-B refiner was explored. The results show that under the same addition amount of Al-Ti-B refiner, the ultrasonic bending vibration can refine the grains of the cast rolling strip, make the distribution of precipitates more uniform, reduce the slag inclusion defects, and improve the mechanical properties to a certain extent. The microstructure and properties of the ultrasonic cast rolling strip with 0.18 wt% Al-Ti-B refiner or 0.12 wt% Al-Ti-B refiner are better than those of the conventional cast rolling strip, but the microstructure and properties of the ultrasonic cast rolling strip with 0.09 wt% Al-Ti-B refiner are slightly worse than those of the conventional cast rolling strip. Moreover, after cold rolling, the effect of the ultrasonic bending vibration on the improvement of the microstructure and properties of the aluminum alloy strip is inherited. A comprehensive analysis shows that the use of ultrasonic energy in this paper cannot completely replace the effect of the Al-Ti-B refiner, but it can reduce the addition amount of the Al-Ti-B refiner by 1/3.

Clinical and imaging features of vertebrobasilar dolichoectasia combined with posterior circulation infarction: A retrospective case series study.

This study aims to analyze the clinical and imaging features of vertebrobasilar dolichoectasia (VBD) combined with posterior circulation infarction, and to explore risk factors for the occurrence of posterior circulation infarction in VBD patients.VBD patients were divided into 2 groups, according to the results of the imaging examination: posterior circulation infarction group and nonposterior circulation infarction group. The demographics, vascular risk factors, imaging, and other clinical data of the VBD patients were collected and retrospectively compared, and the risk factors for the occurrence of posterior circulation infarction in VBD patients were analyzed. The relationship between imaging features of the VBD blood supply artery and the infarct site was also analyzed.A total of 56 VBD patients were included into the analysis. Among these patients, 26 patients had posterior circulation infarction. Infarction occurred in the blood supply area of the posterior cerebral artery in 14 patients. The difference in the height of the basilar artery bifurcation between patients with vertebrobasilar artery blood supply area infarction and patients with posterior cerebral artery supply area infarction was statistically significant. Hypertension and posterior circulation intracranial atherosclerosis were the risk factors for posterior circulation infarction in VBD patients.Elevated basilar artery bifurcation is a risk factor for infarction in the posterior cerebral artery supply area in VBD patients. Posterior circulation infarction in VBD may be the comprehensive result of multiple factors, such as congenital defects of the basilar artery wall, hypertension, and atherosclerotic lesions.