Stress-Induced Hyperglycemia and Remote Diffusion-Weighted Imaging Lesions in Primary Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: Stress-induced hyperglycemia (SIH) is the relative transient increase in glucose during a critical illness such as intracerebral hemorrhage (ICH) and is likely to play an important role in the pathogenesis of remote diffusion-weighted imaging (DWI) lesion (R-DWIL) in primary ICH. We sought to determine the association between SIH and the occurrence of R-DWILs. METHODS: We prospectively enrolled primary ICH patients within 14 days after onset from November 2016 to May 2018. In these patients, cerebral magnetic resonance imaging was performed within 14 days after ICH onset. R-DWIL was defined as a hyperintensity signal in DWI with corresponding hypointensity in apparent diffusion coefficient, and at least 20 mm apart from the hematoma. SIH was measured by stress-induced hyperglycemia ratio (SHR). SHR was calculated by fasting blood glucose (FBG) divided by estimated average glucose derived from glycosylated hemoglobin. The included patients were dichotomized into two groups by the 50th percentile of SHR, and named as SHR (-P50) group and SHR (P50+) group, respectively. We evaluated the association between SHR and R-DWIL occurrence using multivariable logistic regression modeling adjusted for potential confounders. RESULTS: Among the 288 patients enrolled, forty-six (16.0%) of them had one or more R-DWILs. Compared with the patients in the lower 50% of SHR (SHR [-P50]), the odds ratio (OR) [95% confidence interval (CI)] for the higher 50% of SHR (SHR [P50+]) group for R-DWIL occurrence was 3.13 (1.39-7.07) in the total population and 6.33 (2.19-18.30) in population absent of background hyperglycemia after adjusting for potential covariates. Similar results were observed after further adjusted for FBG. CONCLUSIONS: Our study demonstrated that SIH was associated with the occurrence of R-DWILs in patients with primary ICH within 14 days of symptom onset.

Hyperbaric Oxygen Preconditioning Attenuates Hemorrhagic Transformation Through Reactive Oxygen Species/Thioredoxin-Interacting Protein/Nod-Like Receptor Protein 3 Pathway in Hyperglycemic Middle Cerebral Artery Occlusion Rats.

OBJECTIVES: To clarify whether hyperbaric oxygen preconditioning can attenuate hyperglycemia-enhanced hemorrhagic transformation and to establish a role for Nod-like receptor protein 3 inflammasome in the pathophysiology of hemorrhagic transformation. DESIGN: Controlled prospective animal study. SETTING: University research laboratory. SUBJECTS: Male Sprague-Dawley rats weighing 260-280 g. INTERVENTIONS: Rats received 1-hour-long hyperbaric oxygen preconditioning for five consecutive days. Hyperglycemic middle cerebral artery occlusion model was induced at 24 hours after the last hyperbaric oxygen exposure. Reactive oxygen species scavenger (N-acetyl-L-cysteine), thioredoxin-interacting protein small interfering RNA, and Nod-like receptor protein 3 small interfering RNA were given in different groups separately to verify the possible pathway. MEASUREMENTS AND MAIN RESULTS: Rats were randomly divided into sham, middle cerebral artery occlusion, middle cerebral artery occlusion + dextrose, middle cerebral artery occlusion + dextrose + normobaric oxygen preconditioning, middle cerebral artery occlusion + dextrose + hyperbaric oxygen, middle cerebral artery occlusion + dextrose + hyperbaric oxygen + N-acetyl-L-cysteine, middle cerebral artery occlusion + dextrose + hyperbaric oxygen + control small interfering RNA, middle cerebral artery occlusion + dextrose + hyperbaric oxygen + thioredoxin-interacting protein small interfering RNA, and middle cerebral artery occlusion + dextrose + hyperbaric oxygen + Nod-like receptor protein 3 small interfering RNA groups. Hyperglycemia was induced by administration of 50% dextrose (6 mL/kg) intraperitoneally 30 minutes before middle cerebral artery occlusion. Control small interfering RNA/thioredoxin-interacting protein small interfering RNA or Nod-like receptor protein 3 small interfering RNA (500 pmol/5 µL) were injected intracerebroventricularly 72 hours before middle cerebral artery occlusion for intervention. The neurologic scores, infarction and hemorrhage volumes, the expression of Nod-like receptor protein 3, and its downstream targets were analyzed. Hyperbaric oxygen preconditioning decreased both infarction and hemorrhage volumes and improved neurobehavioral function. In addition, hyperbaric oxygen preconditioning provided additional protective effects in hemorrhagic transformation, which was independent of infarction volume. The benefits of hyperbaric oxygen preconditioning on hyperglycemic middle cerebral artery occlusion rats were reversed after blocking the reactive oxygen species/thioredoxin-interacting protein/Nod-like receptor protein 3 pathway. CONCLUSIONS: Nod-like receptor protein 3 inflammasome played an important role in hyperglycemia-enhanced hemorrhagic transformation. Hyperbaric oxygen preconditioning attenuated hemorrhagic transformation through reactive oxygen species/thioredoxin-interacting protein/Nod-like receptor protein 3 pathway.

Treatment with intravenous alteplase in ischaemic stroke patients with onset time between 4.5 and 24 hours (HOPE): protocol for a randomised, controlled, multicentre study.

BACKGROUND: While intravenous thrombolysis is recommended for patients who had an acute ischaemic stroke (AIS) within 4.5 hours of symptom onset, there are few randomised trials investigating the benefits of thrombolysis beyond this therapeutic window. AIM: To determine whether patients who had an AIS selected with the presence of potentially salvageable tissue on CT perfusion at 4.5-24 hours after stroke onset (for stroke with unknown onset time, the midpoint of the time last known to be well and symptom recognition time; for wake-up stroke, the midpoint of the time last known to be well or sleep onset and wake up time) will benefit from intravenous thrombolysis. DESIGN: HOPE is a prospective, multicentre, randomised, open-label blinded endpoint trial with the stage of phase III. The treatment allocation employs 1:1 randomisation. The treatment arm under investigation is alteplase with standard therapy, the control arm is standard therapy. Eligibility imaging criteria include ischaemic core volume ≤70 mL, penumbra ≥10 mL and mismatch ≥20%. STUDY OUTCOMES: The primary outcome is non-disabled functional outcome (assessed as modified Rankin Scale score of 0-1 at 90 days). DISCUSSION: HOPE is the first trial to investigate whether intravenous thrombolysis with alteplase offers benefits in patients who had an AIS presenting within 4.5-24 hours, which has the potential to extend time window and expand eligible population for thrombolysis therapy.

Combined effect of cortical superficial siderosis and cerebral microbleed on short-term and long-term outcomes after intracerebral haemorrhage.

BACKGROUND AND PURPOSE: Cortical superficial siderosis (cSS) and cerebral microbleed (CMB) have distinct effects on intracerebral haemorrhage (ICH). We aim to investigate the combined effect of cSS and CMB on outcomes after ICH. METHODS: Based on a single-centre stroke registry database, patients with spontaneous ICH who had CT scan within 48 hours after ictus and MRI subsequently were identified. Eligible patients were divided into four groups (cSS-CMB-, cSS-CMB+, cSS+CMB-, cSS+CMB+) according to cSS and CMB on susceptibility-weighted image of MRI. Primary outcomes were haematoma volume on admission and unfavourable outcome defined as modified Rankin Scale scores ≥3 at 3 months. Secondary outcomes were all-cause death, recurrence of stroke and ICH during follow-up (median follow-up 2.0 years, IQR 1.0-3.0 years). RESULTS: A total of 673 patients were identified from 1044 patients with spontaneous ICH. 131 (19.5%) had cSS and 468 (69.5%) had CMB. Patients with cSS+CMB+ had the highest rate of poor outcome at 3 months, as well as all-cause death, recurrent stroke and ICH during follow-up. In cSS- patients, CMB was associated with smaller haematoma (ß -0.13; 95% CI -0.22 to -0.03; p=0.009), but it still increased risks of recurrent ICH (OR 4.6; 95% CI 1.3 to 15.6; p=0.015) and stroke (OR 2.0; 95% CI 1.0 to 4.0; p=0.049). These effects of CMB became unremarkable in the context of cSS+. CONCLUSIONS: Patients with different combinations of cSS and CMB have distinct patterns of short-term and long-term outcomes. Although CMB is related to restrained haematoma, it does not improve long-term outcomes. TRIAL REGISTRATION NUMBER: NCT04803292.

Cortical superficial siderosis, hematoma volume, and outcomes after intracerebral hemorrhage: a mediation analysis.

Background: Previous studies have shown that cortical superficial siderosis (cSS) can increase hematoma volume and predict poor outcomes following primary intracerebral hemorrhage (ICH). Objective: We aimed to determine whether a large hematoma volume was the essential factor contributing to worse outcomes of cSS. Methods: Patients with spontaneous ICH underwent a CT scan within 48 h after ictus. Evaluation of cSS was performed using magnetic resonance imaging (MRI) within 7 days. The 90-day outcome was assessed using the modified Rankin Scale (mRS). In addition, we investigated the correlation between cSS, hematoma volume, and 90-day outcomes using multivariate regression and mediation analyses. Results: Among the 673 patients with ICH [mean (SD) age, 61 (13) years; 237 female subjects (35.2%); median (IQR) hematoma volume, 9.0 (3.0-17.6) ml], 131 (19.5%) had cSS. There was an association between cSS and larger hematoma volume (ß = 4.449, 95% CI 1.890-7.009, p < 0.001) independent of hematoma location and was also related to worse 90-day mRS (ß = 0.333, 95% CI 0.008-0.659, p = 0.045) in multivariable regression. In addition, mediation analyses revealed that hematoma volume was an essential factor mediating the effect of cSS on unfavorable 90-day outcomes (proportion mediated:66.04%, p = 0.01). Conclusion: Large hematoma volume was the major charge of directing cSS to worse outcomes in patients with mild to moderate ICH, and cSS was related to a larger hematoma in both lobar and non-lobar areas. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT04803292, identifier: NCT04803292.

Deep learning for automatically predicting early haematoma expansion in Chinese patients.

BACKGROUND AND PURPOSE: Early haematoma expansion is determinative in predicting outcome of intracerebral haemorrhage (ICH) patients. The aims of this study are to develop a novel prediction model for haematoma expansion by applying deep learning model and validate its prediction accuracy. METHODS: Data of this study were obtained from a prospectively enrolled cohort of patients with primary supratentorial ICH from our centre. We developed a deep learning model to predict haematoma expansion and compared its performance with conventional non-contrast CT (NCCT) markers. To evaluate the predictability of this model, it was also compared with a logistic regression model based on haematoma volume or the BAT score. RESULTS: A total of 266 patients were finally included for analysis, and 74 (27.8%) of them experienced early haematoma expansion. The deep learning model exhibited highest C statistic as 0.80, compared with 0.64, 0.65, 0.51, 0.58 and 0.55 for hypodensities, black hole sign, blend sign, fluid level and irregular shape, respectively. While the C statistics for swirl sign (0.70; p=0.211) and heterogenous density (0.70; p=0.141) were not significantly higher than that of the deep learning model. Moreover, the predictive value for the deep learning model was significantly superior to that of the logistic model of haematoma volume (0.62; p=0.042) and the BAT score (0.65; p=0.042). CONCLUSIONS: Compared with the conventional NCCT markers and BAT predictive model, the deep learning algorithm showed superiority for predicting early haematoma expansion in ICH patients.

Association Between Insulin Resistance and Remote Diffusion-Weighted Imaging Lesions in Primary Intracerebral Hemorrhage.

Background: Abnormal glucose metabolism was shown to be associated with the occurrence of remote diffusion-weighted imaging lesions (R-DWILs) after primary intracerebral hemorrhage (ICH) onset. Insulin resistance is a metabolic disorder that was regarded as an indicator of chronic systemic inflammation. In this study, we aimed to determine the effect of insulin resistance on the occurrence of R-DWILs in ICH. Methods: Patients with primary ICH within 14 days after onset were prospectively enrolled from November 2017 to October 2019. R-DWILs was defined as remote focal hyperintensity from the hematoma in DWI, with corresponding hypointensity in apparent diffusion coefficient. The homeostasis model assessment of insulin resistance (HOMA-IR) was used for insulin resistance estimation and calculated as fasting insulin (µU/ml) × fasting glucose (mmol/L)/22.5. Patients in our cohort were divided into four groups according to HOMA-IR index quartiles. Logistic regression analysis and smoothing plots were used to evaluate the association of HOMA-IR with R-DWIL occurrence. Sensitivity analysis was performed in non-diabetic patients, non-obese patients, hypertensive ICH patients, and patients 60 years and older separately. The association between HOMA-IR and systemic inflammatory immune indices neutrophil to lymphocyte ratio (NLR) and monocyte to lymphocyte ratio (MLR) was examined with multiple linear regression analysis. Results: Among the 345 patients, 54 (15.7%) had R-DWILs. Both the third and fourth quartiles of HOMA-IR index were robustly associated with an increased risk of R-DWIL occurrence (adjusted OR 3.58, 95% CI 1.33-9.65; adjusted OR 3.91, 95%CI 1.47-10.41) when compared with the first quartile. The association was consistent in non-diabetic, non-obese, hypertensive ICH patients, as well as in patients 60 years and older. Furthermore, both NLR and MLR were independently associated with HOMA-IR. Conclusions: Our study suggested that insulin resistance evaluated with HOMA-IR index was independently associated with the presence of R-DWILs in patients with acute and subacute primary ICH. It may provide new insights into the metabolism-related brain injury after ICH ictus.

Early elevated neutrophil-to-lymphocyte ratio associated with remote diffusion-weighted imaging lesions in acute intracerebral hemorrhage.

AIMS: To explore the relationship between the circulating neutrophil-to-lymphocyte ratio (NLR) and the remote diffusion-weighted imaging lesions (R-DWILs) after spontaneous intracerebral hemorrhage (ICH). METHODS: Consecutive patients with spontaneous ICH were prospectively collected from November 2016 to May 2018 and retrospectively analyzed. We included subjects who presented within 24 hours after symptom onset and were free of detectable infections on admission or in hospital. Blood samples were obtained at 24-48 hours after ICH ictus, while all complete MRI scans were performed at 5-8 days. R-DWILs were defined as focal hyperintensities remote from the site of the ICH or the peri-hematoma regions. NLR was calculated by dividing the absolute neutrophil counts by the absolute lymphocyte counts. Multivariate binary logistic regression models were generated to evaluate the relationship between NLR and R-DWILs. RESULTS: One hundred sixty-three subjects met eligibility criteria (age 62.3 ± 13.6 years, 60.7% males), of whom 31(19.0%) experienced R-DWILs. Higher circulating NLR was documented in patients with R-DWILs. With the best cutoff value of 6.01, elevated NLR was independently associated with the presence of R-DWILs (OR = 3.170, 95% CI 1.306-7.697, P = .011) in the bivariate logistic regression analysis with adjustment for age, sex, atrial fibrillation, previous ischemic stroke/TIA, SBP on admission, hematoma volume, and IVH. CONCLUSIONS: This study provides significant evidence of the association between circulating NLR and R-DWILs in spontaneous ICH patients. Patients with NLR > 6.01 at 24-48 hours after ICH ictus should be paid more attention to when evaluating R-DWILs.

Thrombin disrupts vascular endothelial-cadherin and leads to hydrocephalus via protease-activated receptors-1 pathway.

AIMS: Previous studies indicated that intraventricular injection of thrombin would induce hydrocephalus. But how thrombin works in this process remains unclear. Since cadherin plays a critical role in hydrocephalus, we aimed to explore the mechanisms of how thrombin acted on choroid plexus vascular endothelium and how thrombin interacted with vascular endothelial-cadherin (VE-cadherin) during hydrocephalus. METHODS: There were two parts in this study. Firstly, rats received an injection of saline or thrombin into the right lateral ventricle. Magnetic resonance imaging was applied to measure the lateral ventricle volumes. Albumin leakage and Evans blue content were assessed to test the blood-brain barrier function. Immunofluorescence and Western blot were applied to detect the location and the expression of VE-cadherin. Secondly, we observed the roles of protease-activated receptors-1 (PAR1) inhibitor (SCH79797), Src inhibitor (PP2), p21-activated kinase-1 (PAK1) inhibitor (IPA3) in the thrombin-induced hydrocephalus, and their effects on the regulation of VE-cadherin. RESULTS: Our study demonstrated that intraventricular injection of thrombin caused significant downregulation of VE-cadherin in choroid plexus and dilation of ventricles. In addition, the inhibition of PAR1/p-Src/p-PAK1 pathway reversed the decrease of VE-cadherin and attenuated thrombin-induced hydrocephalus. CONCLUSIONS: Our results suggested that the thrombin-induced hydrocephalus was associated with the inhibition of VE-cadherin via the PAR1/p-Src/p-PAK1 pathway.

CD200Fc Improves Neurological Function by Protecting the Blood-brain Barrier after Intracerebral Hemorrhage.

CD200 is widely distributed in the central nervous system and plays an essential role in the immune response in neurological diseases. However, little is currently known about the effects of CD200 signaling on the blood-brain barrier (BBB) function after intracerebral hemorrhage (ICH). In this study, the role of CD200 during ICH in an autologous blood induced mouse ICH model was investigated. Following ICH, critical protein expression, BBB permeability, and neurological function were measured with or without CD200Fc administration. Our results showed that both the expression of CD200 and CD200R1 decreased after ICH and administration of CD200Fc attenuated BBB leakage and improved neurological functions. In conclusion, our work demonstrated that CD200Fc might be a potential treatment option for ICH by protecting the BBB and improving functional outcomes.

Cerebral venous collaterals: A new fort for fighting ischemic stroke?

Stroke therapy has entered a new era highlighted by the use of endovascular therapy in addition to intravenous thrombolysis. However, the efficacy of current therapeutic regimens might be reduced by their associated adverse events. For example, over-reperfusion and futile recanalization may lead to large infarct, brain swelling, hemorrhagic complication and neurological deterioration. The traditional pathophysiological understanding on ischemic stroke can hardly address these occurrences. Accumulating evidence suggests that a functional cerebral venous drainage, the major blood reservoir and drainage system in brain, may be as critical as arterial infusion for stroke evolution and clinical sequelae. Further exploration of the multi-faceted function of cerebral venous system may add new implications for stroke outcome prediction and future therapeutic decision-making. In this review, we emphasize the anatomical and functional characteristics of the cerebral venous system and illustrate its necessity in facilitating the arterial infusion and maintaining the cerebral perfusion in the pathological stroke content. We then summarize the recent critical clinical studies that underscore the associations between cerebral venous collateral and outcome of ischemic stroke with advanced imaging techniques. A novel three-level venous system classification is proposed to demonstrate the distinct characteristics of venous collaterals in the setting of ischemic stroke. Finally, we discuss the current directions for assessment of cerebral venous collaterals and provide future challenges and opportunities for therapeutic strategies in the light of these new concepts.

Association of Renal Dysfunction With Remote Diffusion-Weighted Imaging Lesions and Total Burden of Cerebral Small Vessel Disease in Patients With Primary Intracerebral Hemorrhage.

Objective: Remote diffusion-weighted imaging (DWI) lesions (R-DWIL) found in intracerebral hemorrhage (ICH) patients are considered as an additional marker of cerebral small vessel disease (cSVD). This study aimed to investigate the association of renal dysfunction and R-DWIL, as well as the total burden of cSVD on magnetic resonance imaging among patients with primary ICH. Methods: One hundred and twenty-six consecutive patients were prospectively enrolled. R-DWIL on DWI, as well as other imaging markers of cSVD, including lacunes, white matter lesions, cerebral microbleeds, and enlarged perivascular spaces were rated using validated scales. Renal dysfunction was evaluated either by reduced estimated glomerular filtration rate (eGFR) or the presence of proteinuria or increased cystatin C. Results: After adjustments for potential confounders by logistic regression, impaired eGFR [odds ratio (OR) 6.00, 95% confidence interval (CI) 1.73-20.78], proteinuria (OR 3.07, 95% CI 1.25-7.54) and increased cystatin C (OR 2.73, 95% CI 1.11-6.72) were correlated with presence of R-DWIL. A similar association was also found between cystatin C levels (OR 3.16, 95% CI 1.39-7.19), proteinuria (OR 2.79, 95% CI 1.34-5.83) and the comprehensive cSVD burden. Conclusions: Renal dysfunction are associated with the presence of R-DWIL, and total burden of cSVD in patients with primary ICH.

Factors Associated With Remote Diffusion-Weighted Imaging Lesions in Spontaneous Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: Remote diffusion-weighted imaging lesions (R-DWILs) have been detected in patients with spontaneous intracerebral hemorrhage (ICH) and may be correlated with clinical outcome. However, the mechanisms and characteristics of R-DWILs have not been fully elucidated. In this study, we sought to demonstrate the clinical characteristics of R-DWILs in spontaneous ICH. METHODS: We prospectively collected data with spontaneous ICH patients from November 2016 to December 2017. In these patients, cerebral magnetic resonance imaging was performed within 28 days after ICH onset. R-DWIL was defined as a hyperintensity signal in diffusion-weighted imaging with corresponding hypointensity in apparent diffusion coefficient, and at least 20 mm apart from the hematoma. We compared two groups of patients with or without R-DWIL with the demographic and clinical characteristics, laboratory parameters, and imaging characteristics, by using univariate and multivariate analysis. RESULTS: Of the 222 patients enrolled, a total of 75 R-DWILs were observed in 41 patients (18.5%). Among these lesions, the cortical and subcortical areas were the predominant locations with a proportion of 77.3%. The median diameter of R-DWILs was 7 mm (range 2-20 mm). Twelve patients were found having more than one lesion, with five among which showed R-DWILs in multiple cerebral arterial territories. In multivariate modeling, higher fasting glucose (OR 1.231; 95% CI 1.035-1.465; p = 0.019) and more severe white matter hyperintensity (WMH) (OR 6.589; 95% CI 2.975-14.592; p < 0.001) were independent factors related to the presence of R-DWILs. CONCLUSION: In our study, approximately one-fifth of ICH patients showed coexistence of R-DWIL. Higher fasting glucose and more severe WMH were associated with R-DWIL occurrence in spontaneous ICH.

Remote Diffusion-Weighted Imaging Lesions in Intracerebral Hemorrhage: Characteristics, Mechanisms, Outcomes, and Therapeutic Implications.

Spontaneous intracerebral hemorrhage (ICH) is one of the most fatal form of stroke, with high mortality and disability rate. Small diffusion-weighed imaging lesions are not rare to see in regions remote from the hematoma after ICH and have been generally considered as related with poor outcome. In this review, we described the characteristics of remote ischemic lesions, discussed the possible mechanisms and clinical outcomes of these lesions, and evaluated the potential therapeutic implications.

Congenital anomaly of the posterior arch of the atlas: a rare risk factor for posterior circulation stroke.

We report an extremely rare case involving a posterior arch anomaly of the atlas, causing a vertebral artery dissection (VAD) induced posterior circulation stroke. A 16-year-old girl was admitted to hospital because of new onset dizziness. VAD related multiple infarction in the posterior circulation was revealed. The congenital posterior arch anomaly of the atlas, along with instability of the atlantoaxial joint, were discovered accidentally during follow-up. This is the first case of ischemic stroke related to atlantal posterior arch aplasia and atlantoaxial instability. Although rare, it reminds us that investigation of the craniovertebral junction should be considered when stroke occurs in young patients.

Congenital anomaly of the posterior arch of the atlas: a rare risk factor for posterior circulation stroke.

We report an extremely rare case involving a posterior arch anomaly of the atlas, causing a vertebral artery dissection (VAD) induced posterior circulation stroke. A 16-year-old girl was admitted to hospital because of new onset dizziness. VAD related multiple infarction in the posterior circulation was revealed. The congenital posterior arch anomaly of the atlas, along with instability of the atlantoaxial joint, were discovered accidentally during follow-up. This is the first case of ischemic stroke related to atlantal posterior arch aplasia and atlantoaxial instability. Although rare, it reminds us that investigation of the craniovertebral junction should be considered when stroke occurs in young patients.

Recombinant Gas6 augments Axl and facilitates immune restoration in an intracerebral hemorrhage mouse model.

Axl, a tyrosine kinase receptor, was recently identified as an essential component regulating innate immune response. Suppressor of cytokine signaling 1 and suppressor of cytokine signaling 3 are potent Axl-inducible negative inflammatory regulators. This study investigated the role of Axl signaling pathway in immune restoration in an autologous blood-injection mouse model of intracerebral hemorrhage. Recombinant growth arrest-specific 6 (Gas6) and R428 were administrated as specific agonist and antagonist. In vivo knockdown of Axl or suppressor of cytokine signaling 1 and suppressor of cytokine signaling 3 by siRNA was applied. After intracerebral hemorrhage, the expression of endogenous Axl, soluble Axl, and Gas6 was increased, whereas the expression of suppressor of cytokine signaling 1 and suppressor of cytokine signaling 3 was inhibited. Recombinant growth arrest-specific 6 administration alleviated brain edema and improved neurobehavioral performances. Moreover, enhanced Axl phosphorylation with cleavage of soluble Axl (sAxl), and an upregulation of suppressor of cytokine signaling 1 and suppressor of cytokine signaling 3 were observed. In vivo knockdown of Axl and R428 administration both abolished the effect of recombinant growth arrest-specific 6 on brain edema and also decreased the expression suppressor of cytokine signaling 1 and suppressor of cytokine signaling 3. In vivo knockdown of suppressor of cytokine signaling 1 and suppressor of cytokine signaling 3 aggravated cytokine releasing despite of recombinant growth arrest-specific 6. In conclusion, Axl plays essential role in immune restoration after intracerebral hemorrhage. And recombinant growth arrest-specific 6 attenuated brain injury after intracerebral hemorrhage, probably by enhancing Axl phosphorylation and production of suppressor of cytokine signaling 1 and suppressor of cytokine signaling 3.

The Role of Nitric Oxide and Sympathetic Control in Cerebral Autoregulation in the Setting of Subarachnoid Hemorrhage and Traumatic Brain Injury.

Cerebral autoregulation is defined as the mechanism by which constant cerebral blood flow is maintained despite changes of arterial blood pressure, and arterial blood pressure represents the principle aspect of cerebral autoregulation. The impairment of cerebral autoregulation is reported to be involved in several diseases. However, the concept, mechanisms, and pathological dysfunction of cerebral autoregulation are beyond full comprehension. Nitric oxide control and sympathetic control are main contributors to cerebral autoregulation. Although impaired cerebral autoregulation after nitric oxide inhibition or sympathetic ganglia blockade is reported, managing the inhibition or blockade can have negative consequences and needs further exploration. Additionally, impaired cerebral autoregulation following subarachnoid hemorrhage and traumatic brain injury has been proven by several descriptive studies, although without corresponding explanations. As the most important mechanisms of cerebral autoregulation, the changes of nitric oxide and sympathetic stimulation play significant roles in these insults. Therefore, the in-depth researches of nitric oxide and sympathetic nerve in cerebral autoregulation may help to develop new therapeutic targets.

Statin withdrawal beyond acute phase affected outcome of thrombolytic stroke patients: an observational retrospective study.

Statin withdrawal is associated with deleterious outcome on stroke patients. Whether risk changes over time, depends on concomitant treatment of intravenous thrombolysis, or both remains to be clarified. We assessed the influence of statin withdrawal within 3 weeks while initiated in acute phase (72 hours) among patients receiving intravenous thrombolysis.This was a monocentered retrospective observational study enrolling intravenous thrombolytic stroke patients from June 2009 to May 2014. Consecutive patients were distinguished into 3 groups according to the initiation and withdrawal of statin: the reference group (not received statin in 72 hours after stroke onset); the continued group (initiated statin therapy in 72 hours and continued for at least 3 weeks); the withdrawal group (initiated statin in 72 hours and discontinued within 3 weeks). All reasons for cessation were recorded. The effects of statin withdrawal on short-, mid-, and long-term outcomes were evaluated as neurologic improvement (NIH Stroke Scale [NIHSS] score improvement ≥4 from baseline or later NIHSS = 0), death or poor outcome (modified Rankin Scale [mRS] ≥4), and favorable outcome (mRS ≤2). We further evaluate statin withdrawal effects in cardioembolic stroke patients for these outcomes.Among 443 IVT patients enrolled, 367 were included in the final study population. There were 88, 188, and 91 patients in the reference, continued, and withdrawal groups, respectively. Multivariable logistic regression showed that statin withdrawal compared with the reference was related to a lower possibility of long-term favorable outcome (OR = 0.45, 95% CI [0.22, 0.90], P = 0.024). Compared with the continued group, the adjusted OR of statin withdrawal was 0.40 (95% CI [0.22, 0.72], P = 0.002) and 2.52 (95% CI [1.34, 4.75], P = 0.004) for long-term favorable and poor/death outcomes, respectively. Also, results were similar for cardioembolic stroke patients (OR = 0.35, 95% CI [0.14, 0.89], P = 0.027 of favorable outcome and OR = 3.62, 95% CI [1.37, 9.62], P = 0.010 of poor/death outcome).In a real-world setting, for stroke patients receiving intravenous thrombolysis, statin withdrawal within 3 weeks initiating in 72 hours may have a harmful effect on the long-term neurologic outcome, even in cardioembolic stroke patients.

Aberrant CD200/CD200R1 expression and function in systemic lupus erythematosus contributes to abnormal T-cell responsiveness and dendritic cell activity.

INTRODUCTION: CD200 is a type I transmembrane glycoprotein that can regulate the activation threshold of inflammatory immune responses, polarize cytokine production, and maintain immune homeostasis. We therefore evaluated the functional status of CD200/CD200 receptor 1 (CD200R1) interactions in subjects with systemic lupus erythematosus (SLE). METHODS: Serum CD200 level was detected by ELISA. The expression of CD200/CD200R1 by CD4+ T cells and dendritic cells (DCs) was examined by flow cytometry, and then compared between SLE patients and healthy controls. Peripheral blood mononuclear cells were stained with carboxyfluorescein diacetate succinimidyl ester and annexin V/propidium iodide for evaluation of the effect of CD200 on cell proliferation and apoptosis. In addition, the effect of CD200 on DC function was determined by transwell migration assay as well as by measurement of binding and phagocytosis of apoptotic cells. RESULTS: In SLE patients, the number of CD200+ cells and the level of soluble CD200 were significantly higher than in healthy controls, whereas the expression of CD200R1 by CD4+ T cells and DCs was decreased. Furthermore, the increased CD200 expression by early apoptotic cells contributed to their diminished binding and phagocytosis by DCs in SLE. Importantly, the engagement of CD200 receptor on CD4+ T cells with CD200-Fc fusion protein in vitro reduced the differentiation of T-helper type 17 cells and reversed the defective induction of CD4+CD25highFoxP3+ T cells by transforming growth factor beta in SLE patients. Conversely, blockade of CD200-CD200R1 interaction with anti-CD200R1 antibody promoted CD4+ T-cell proliferation. CONCLUSION: CD200 and CD200R1 expression and function are abnormal in SLE and may contribute to the immunologic abnormalities in SLE.