Comparision of Mechanical Thrombectomy With Contact Aspiration or Stent Retriever in Patients With Large-vessel Occlusion in Acute Ischemic Stroke.

OBJECTIVES: Whether the direct aspiration approach of thrombectomy for recanalization in patients with acute ischemic stroke has a similar efficacy and safety compared to the stent-retriever still remains uncertain. METHODS: A retrospective data analysis was performed to identify patients with large cerebral artery acute ischemic stroke treated with endovascular thrombectomy. The study was conducted between January 2018 and December 2019 in a single stroke center. RESULTS: Twenty patients met inclusion criteria for this study with a mean age 66.64 ±â€Š17.92 years' old. The symptom occurred on the left side were in 13, and the right side in 7. The location of occlusion was 8 in M1 of the middle cerebral artery of M2, and 6 in internal carotid artery. Nine patients were randomized to first-line treatment with contact aspiration and eleven to first-line treatment with a stent retriever. The mean time from admission time to groin puncture was 55.51 ±â€Š31.03 minutes. The average time from groin puncture to maximal revascularizion after mechanical thrombectomy was 50.9 ±â€Š22.5 minutes in contact aspiration group, but this time was 71.37 ±â€Š25.45 minutes in the group of stent retriever. The overall successful revascularization rate (TICI 2b-3) was 88.9% in contact aspiration (TICI2a = 1, TICI 2b = 4 patients, TICI 3 = 4 patients), and 90.1% in stent retriever (TICI2a = 1, TICI 2b = 6 patients, TICI 3 = 4 patients). DISCUSSION: First-line thrombectomy with contact aspiration did not result in a higher successful revascularization rate at the end of the procedure but had a short time from groin puncture to maximal revascularizion.

Calcium sensing receptor contribute to early brain injury through the CaMKII/NLRP3 pathway after subarachnoid hemorrhage in mice.

The subversive role of Calcium sensing receptor (CaSR) in cerebral ischemia and traumatic brain injury has been recently reported. Nevertheless, the role of CaSR in early brain injury (EBI) after subarachnoid hemorrhage (SAH) remains unexplored. Using the endovascular perforation model in mice, this study was aimed at investigating the role and potential mechanism of CaSR in EBI after SAH. Gadolinium trichloride (GdCI3), an agonist of CaSR, and NPS-2143, an inhibitor of CaSR, were administered intraperitoneally. The CaMKII inhibitor KN-93 was injected to intracerebroventricular. We found that CaSR expression was increased and widely expressed in neurons, astrocytes, and microglia after SAH. GdCI3 further deteriorated neurological function, brain edema, neurodegeneration, which were alleviated by NPS-2143. Also, GdCI3 increased the level of CaMKII phosphorylation, and upregulated expression of NLRP3, cleaved caspase-1, and IL-1ß, which were attenuated by NPS-2143. Besides, CaMKII inhibitor KN-93 down-regulated the upregulated expression of NLRP3, cleaved caspase-1, and IL-1ß induced by GdCI3. In conclusion, CaSR activation promotes early brain injury, which may be related to the CaMKII/NLRP3 signaling pathway.

Enhancement of Hematoma Clearance With CD47 Blocking Antibody in Experimental Intracerebral Hemorrhage.

Background and Purpose- Our previous studies found that erythrocyte CD47 has a role in regulating hematoma resolution following experimental intracerebral hemorrhage (ICH). The current study examined whether or not a CD47 blocking antibody enhances hematoma clearance in a mouse ICH. Methods- ICH was induced by intracaudate injection of autologous blood in adult C57BL/6 mice. Mice had an ICH or ICH with CD47 blocking antibody or IgG coinjection. In subgroups of CD47 blocking antibody-treated mice, clodronate (to deplete microglia/macrophages) or control liposomes were coinjected. The effects of CD47 blocking antibody on ICH-induced brain injury were also tested in both males and females. Mice had magnetic resonance imaging to examine clot volume, iron deposition, brain swelling, and brain tissue loss. Behavioral tests were performed in all mice, and brains were harvested for brain immunohistochemistry. Results- In male mice, CD47 blocking antibody speeded up hematoma/iron clearance by macrophages/microglia and reduced ICH-induced brain swelling, neuronal loss, and neurological deficits. In contrast, clodronate liposome-induced microglia/macrophage depletion caused more severe brain swelling, neuronal loss, and functional deficits. In addition, similar injury severity in males and females was found in IgG control group and CD47 blocking antibody was also effective in females. Conclusions- Blocking CD47 in the hematoma speeded hematoma clearance and reduced brain injury after ICH suggesting it could be a treatment for ICH patients with surgical clot removal.

TIMP1 protects against blood-brain barrier disruption after subarachnoid haemorrhage by inhibiting ubiquitination of astrocytic ß1-integrin.

BACKGROUND: Astrocytes regulate blood-brain barrier (BBB) integrity, whereas subarachnoid haemorrhage (SAH) results in astrocyte dysregulation and BBB disruption. Here, we explored the involvement of tissue inhibitor of matrix metalloprotease-1 (TIMP1) in astrocyte-mediated BBB protection during SAH, along with its underlying mechanisms. METHODS: C57BL/6J mice were used to establish a model of SAH. The effects of TIMP1 on SAH outcomes were analysed by intraperitoneal injection of recombinant mouse TIMP1 protein (rm-TIMP1; 250 µg/kg). The roles of TIMP1 and its effector ß1-integrin on astrocytes were observed by in vivo transduction with astrocyte-targeted adeno-associated virus carrying TIMP1 overexpression plasmid or ß1-integrin RNAi. The molecular mechanisms underlying TIMP1 and ß1-integrin interactions were explored in primary cultured astrocytes stimulated with red blood cells (RBCs). RESULTS: TIMP1 was upregulated after SAH. Administration of rm-TIMP1 mitigated SAH-induced early brain injury (EBI) in male and female mice. TIMP1 was primarily expressed in astrocytes; its overexpression in astrocytes led to increased ß1-integrin expression in astrocytes, along with the preservation of astrocytic endfoot attachment to the endothelium and subsequent recovery of endothelial tight junctions. All of these effects were reversed by the knockdown of ß1-integrin in astrocytes. Molecular analysis showed that TIMP1 overexpression decreased the RBC-induced ubiquitination of ß1-integrin; this effect was partially achieved by inhibiting the interaction between ß1-integrin and the E3 ubiquitin ligase Trim21. CONCLUSION: TIMP1 inhibits the interaction between ß1-integrin and Trim21 in astrocytes, thereby rescuing the ubiquitination of astrocytic ß1-integrin. It subsequently restores interactions between astrocytic endfeet and the endothelium, as well as BBB integrity, eventually mitigating SAH-induced EBI.

Outcome of salvage intra-arterial chemotherapy for recurrent retinoblastoma.

PURPOSE: To examine the outcome of salvage intra-arterial chemotherapy (IAC) for patients with recurrent retinoblastoma after the initial course of IAC and determine the factors influencing clinical outcome. METHODS: A total of 73 eyes of 71 patients with recurrent retinoblastoma undergoing salvage IAC after initial successfully IAC between May 2014 and May 2019 were retrospectively reviewed for clinical outcomes. Ocular survival and progression-free survival were used to examine the efficacy of salvage IAC. The factors influencing clinical outcomes were determined using univariate and multivariate analyses. RESULTS: The salvage IAC was delivered at mean 9.4 months (median 7, range 2.1-38.3 months) following the last cycle of initial IAC. 86.5% (64/73) eyes relapsed 16 months after the initial IAC. After the salvage IAC, 57 eyes (78.1%) were salvaged, and no further-line therapies were required for 36 eyes (49.3%). The 2-year Kaplan-Meier ocular survival and progression-free survival estimates after salvage IAC were 66.4% (95% CI, 31.5-42.1%) and 38.2% (95% CI, 17.8-28.8%), respectively. Univariate and multivariate analyses showed that the ocular survival and progression-free survival after salvage IAC were significantly associated with the history of vitreous seeds (p = 0.02 and p = 0.03, respectively). CONCLUSION: Salvage IAC is effective for the management of recurrent retinoblastoma after the initial successful IAC. Eyes with a history of vitreous seeds in the course of the disease are more likely to relapse and with worse ocular survival. A close follow-up strategy is imperative to treat the recurrent tumour after salvage IAC.

CD47 Blockade Accelerates Blood Clearance and Alleviates Early Brain Injury After Experimental Subarachnoid Hemorrhage.

Aims: Subarachnoid hemorrhage (SAH) is a devastating stroke subtype. Following SAH, erythrocyte lysis contributes to cell death and brain injuries. Blockage of the anti-phagocytic receptor Cluster of Differentiation 47 (CD47) enhances phagocyte clearance of erythrocytes, though it has not been well-studied post-SAH. The current study aims to determine whether anti-CD47 treatment can enhance blood clearance after experimental SAH. Methods: The prechiasmatic blood injection model of SAH was used in mice. Mice were either treated with the CD47-blocking antibody or IgG as control. The effect of the anti-CD47 antibody on blood clearance and neurological function following SAH was determined. Neuroinflammation and neuronal injury were compared between the treatment and control samples on day 1 and day 7 after SAH using flow cytometry, immunofluorescence, Fluoro-Jade C, and Nissl staining, RT-PCR, and Western blot analysis. Results: CD47-blocking antibody sped-up blood clearance after SAH, and resulted in less neuronal injury and neurological deficits than control samples. Microglia played a role in the anti-CD47 blockade. Following SAH Following SAH, CD47 antibody-treated mice had less neuroinflammation and lower levels of apoptosis compared to controls and both one and 7 days. Conclusions: CD47 antibody treatment has a neuroprotective effect following SAH, by increasing blood clearance rate and reducing brain injury. These findings suggest CD47 antibody treatment may improve SAH patient outcomes.

Relationship between chronic hyperglycemia and contrast extravasation in revascularization of symptomatic intracranial atherosclerotic stenosis: A retrospective single-center study.

BACKGROUND AND PURPOSE: Contrast extravasation is one of the most common perioperative complications in symptomatic intracranial atherosclerotic stenosis (ICAS) patients after percutaneous transluminal angioplasty and/or stenting (PTAS). This study aimed to investigate the correlations between the relevant serum biochemical indicators of carbohydrate metabolism and the occurrence of contrast extravasation. METHODS: Patients' demographic characteristics, vascular risk factors and laboratory examination data were collected. Blood routine test, blood biochemical examination and hormone level test within 1 week before surgery were measured in all enrolled subjects. Patients underwent non-contrast CT scans immediately after the endovascular procedure. Follow-up non-contrast CT scans were performed in the next 24 h and repeated as per clinical condition. RESULTS: 104 patients who have undergone effective PTAS were involved in this study. 18 patients have identified as contrast extravasation and there was no obvious abnormality in another 86 cases. There were significant differences in the pre-operative HbA1c, fasting blood sugar and cortisol levels in the subjects regardless of gender between two groups (p < 0.001, p < 0.001 and p = 0.001, respectively). Furthermore, there were statistical differences in E2 and testosterone levels between two groups in both male population (p = 0.035 and p = 0.028, respectively) and female population (p = 0.036 and p = 0.003, respectively). Besides, the AUC value of HbA1c, fasting blood sugar and cortisol levels were all over 0.7 (0.858, 0.780 and 0.752, respectively). The highest AUC value of various combinations was obtained from the combination of HbA1c and cortisol level, which was 0.898. CONCLUSIONS: Patient with chronic hyperglycemia is closely related to contrast extravasation after PTAS. Specific mechanisms might be explored and regarded as promising candidates to prevent contrast extravasation.

[Acute insular infarct increases risk of electrocardiogram changes and sudden cardiac death].

OBJECTIVE: To investigate the influence of location and size of acute insular infarct on stroke-related electrocardiogram (ECG) changes and cardiovascular events. METHODS: Ninety-nine cases admitted to hospital from October 2007 to June 2009, who were diagnosed as acute middle cerebral artery territory infarct within 48 h after onset and without the history of cardiac diseases, were included in the study. The patients were further divided into three groups: major insular infarct, minor insular infarct and control group, according to the infarct size on MRI diffusion-weighted image. The clinical data, ECG changes and cardiovascular events were compared between left and right insular infarct. Logistic regression was applied to determine the independent risk factors of ECG changes and cardiovascular events. RESULT: Large artery atherosclerosis was the main cause of acute insular infarct (71.8 %), which was associated with higher NIHSS score compared to the control group (P < 0.01). Comparing the left and right insular infarct, the frequencies of sinus bradycardia and sudden cardiac death were significantly higher in left insular infarct (P < 0.01 and P < 0.05), while there was a trend that the frequency of atrial fibrillation was higher in right insular infarct (P = 0.079). With the larger size of insular infarct, the frequency of sinus bradycardia, new atrial fibrillation and sudden cardiac death (P<0.01, P<0.05 and P<0.05, respectively) became much higher. Logistic regression analysis showed that major insular infarct was related to the higher frequency of sinus bradycardia (OR = 4.660, 95% CI: 1.646 ~ 13.195; P = 0.004). CONCLUSION: Acute insular infarct is associated with the stroke-related ECG changes and sudden cardiac death. Left insular infarct is related to sinus bradycardia, possibly due to the enhanced parasympathetic tone. It deserves clinical attention that the incidence of cardiac autonomic disturbance becomes higher with the enlarged insular infarct size.

Multinucleated Giant Cells in Experimental Intracerebral Hemorrhage.

Macrophage phagocytosis plays an important role in hematoma clearance after intracerebral hemorrhage (ICH). This study examined the characteristics of multinucleated giant cells (MGCs), a group of macrophages with multiple nuclei, in a mouse ICH model. Whether MGCs could be increased by treatment with a CD47 blocking antibody and decreased by treatment with clodronate liposomes were also examined. ICH was induced via autologous blood injection. Male adult C57BL/6 mice in different groups had (1) ICH alone; (2) ICH with anti-CD47 blocking antibody or control IgG; and (3) ICH with anti-CD47 antibody combined with clodronate liposomes or control liposomes. The effect of anti-CD47 antibody on MGC formation was also tested in females. Brains were harvested at days 3 or 7 for brain histology. Many MGCs were found at day 3 post-ICH, but were reduced at day 7. MGCs phagocytosed many red blood cells and were heme oxygenase-1, ferritin, YM-1, and iNOS positive. CD47 blocking antibody injection increased MGC numbers in the peri-hematomal zone and in the hematoma in both sexes. Co-injection of clodronate liposomes depleted MGCs in both the hematoma core and the peri-hematomal area. In conclusion, MGCs represent a macrophage/microglia subtype with strong phagocytosis capacity. MGCs exhibited not only an M2 but also an M1 phenotype and appeared involved in hemoglobin degradation. Anti-CD47 antibody boosted the number of MGCs, which may contribute to enhance hematoma clearance. Understanding the exact roles of MGCs in ICH may reveal novel targets for ICH treatment.

Delayed substantia nigra damage and leukoencephalopathy after hypoxic-ischemic injury.

Delayed post-anoxic encephalopathy has rarely been reported, and has most commonly been associated with carbon monoxide poisoning. The underlying pathophysiological mechanism is unknown. We describe a patient with a delayed neurologic decline after a good initial recovery from a hypoxic-ischemic event precipitated by acute blood loss. MRI revealed early globus pallidus necrosis followed by delayed substantia nigra damage and leukoencephalopathy. We suggest that anemia might play a role in this pattern of hypoxic-ischemic brain injury.

Overexpression of immunoproteasome low-molecular-mass polypeptide 7 and inhibiting role of next-generation proteasome inhibitor ONX 0912 on cell growth in glioma.

OBJECTIVES: The aim of this study was to determine the expression level of immunoproteasome and its clinical significance in glioma preliminarily. Furthermore, we studied the function and molecular mechanism of proteasome inhibitor ONX 0912 on glioma cell. MATERIALS AND METHODS: The expression of immunoproteasome in glioma and tumor-adjacent brain tissues was detected by western blot. Immunohistochemical technique was used to detect the expression of low-molecular-mass polypeptide 7 in 55 cases of glioma tissues and 6 cases of tumor-adjacent brain tissues. Chi-square test was used to analyze the relationship between the expression level of low-molecular-mass polypeptide 7 and clinical characteristics. Kaplan-Meier method and Cox regression analysis were applied to analyze the correlation between low-molecular-mass polypeptide 7 expression and prognosis of patients. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2Htetrazolium) (MTS) proliferation assay was introduced to detect the impact of ONX 0912 on proliferation of glioma cells. Western blot was used to detect the apoptosis- and autophagy-related protein in glioma cell treated with ONX 0912. RESULTS: Our results showed that only low-molecular-mass polypeptide 7 expression was notably upregulated in gliomas in comparison with tumor-adjacent brain tissues and further increased in malignant gliomas compared with benign gliomas (P < 0.01). In the multivariate Cox proportional regression analyses, it was evident that low-molecular-mass polypeptide 7 was an independent unfavorable prognostic factor (P < 0.05). The results of MTS assay showed that ONX 0912 could inhibit the proliferation of glioma cell. Besides, we found that ONX 0912 could prompt apoptosis and autophagosome accumulation, which may be responsible for inhibiting glioma cell proliferation. CONCLUSION: In conclusion, our results indicated that low-molecular-mass polypeptide 7 might be a candidate prognostic biomarker, and proteasome inhibitor ONX 0912 might act as a potential treatment agent for glioma.

Association of Brain CD163 Expression and Brain Injury/Hydrocephalus Development in a Rat Model of Subarachnoid Hemorrhage.

Hemoglobin contributes to brain cell damage and death following subarachnoid hemorrhage (SAH). While CD163, a hemoglobin scavenger receptor, can mediate the clearance of extracellular hemoglobin it has not been well-studied in SAH. In the current study, a filament perforation SAH model was performed in male rats. T2-weighted and T2*-weighted scans were carried out using a 7.0-Tesla MR scanner 24 h after perforation. T2 lesions and hydrocephalus were determined on T2-weighted images. A grading system based on MRI was used to assess SAH severity. The effects of SAH on CD163 were determined by immunohistochemistry staining and Western blots. SAH led to a marked increase in CD163 levels in cortex, white matter and periventricular regions from days 1 to 7. CD163 stained cells were co-localized with neurons, microglia/macrophages, oligodendrocytes and cleaved caspase-3-positive cells, but not astrocytes. Furthermore, CD163 protein levels were increased in rats with higher SAH grades, the presence of T2 lesions on MRI, or hydrocephalus. In conclusion, CD163 expression is markedly upregulated after SAH. It is associated with more severe hemorrhage, as well as MRI T2 lesion and hydrocephalus development.

Endovascular thrombectomy can be beneficial to acute ischemic stroke patients with large infarcts.

OBJECTIVE: This study aimed to assess whether patients with acute ischemic stroke (AIS) and large infarct lesions benefit from reperfusion management. To determine the efficacy of different recanalization managements on AIS patients with Alberta Stroke Program Early CT Score (ASPECTS) < 6, the authors retrospectively analyzed hospitalized patients with AIS. METHODS: Eighty-nine patients with AIS and ASPECTS < 6 were screened from 13,285 hospitalized patients treated by thrombolysis, thrombectomy, or conventional care in two stroke medical centers. Logistic regression or Fisher's exact test was performed for comparison of the outcome and risk events between patients treated by thrombectomy (or thrombolysis) and conventional care. The modified Rankin Scale (mRS) score was used to assess the major clinical outcome of patients 3 months after disease onset. Disease outcome was also examined by analyzing symptom improvement at discharge. In particular, mortality and symptomatic intracranial hemorrhage (sICH) were evaluated as risk factors. RESULTS: This study included 21 patients who received thrombolysis, 36 patients receiving thrombectomy, and 32 patients receiving conventional treatment. Among these 3 treatments, only the thrombectomy group clearly showed the most encouraging clinical outcome (mRS score 0-2; p < 0.05, Fisher's exact test) and marked improvement (OR 25.84, 95% CI 2.44-273.59) compared with conventional treatment. It is noteworthy that the mortality rate of the thrombectomy and thrombolysis group was similar to that of the conventional group, and thrombectomy and thrombolysis increased the risk of sICH in comparison with conventional care (p < 0.05, Fisher's exact test). CONCLUSIONS: Patients with AIS and ASPECTS < 6 definitely benefited from thrombectomy with higher sICH risk, whereas thrombolysis management showed similar efficacy to the control group.

Neuroprotective Effects of Valproic Acid on Blood-Brain Barrier Disruption and Apoptosis-Related Early Brain Injury in Rats Subjected to Subarachnoid Hemorrhage Are Modulated by Heat Shock Protein 70/Matrix Metalloproteinases and Heat Shock Protein 70/AKT Pathways.

BACKGROUND: Blood-brain barrier (BBB) disruption and neural apoptosis are thought to promote early brain injury (EBI) after subarachnoid hemorrhage (SAH). Previous studies have demonstrated that valproic acid (VPA) decreased brain injury in a prechiasmatic injection model of SAH in mice. It should be noted that the beneficial effects of VPA and the underlying mechanisms have not been fully elucidated. OBJECTIVE: To characterize the effects of VPA on BBB disruption and neural apoptosis and to determine mechanisms involved in EBI after SAH. METHODS: An endovascular perforation model was used to induce SAH in rats. VPA (300 mg/kg) was promptly administered after SAH induction, and the same dose was given 12 hours later. Quercetin (100 mg/kg), an inhibitor of heat shock protein 70 (HSP70), was injected into the peritoneum 2 hours before SAH induction. Mortality, SAH grades, neurological function, Evans Blue extravasation, brain edema, transmission electron microscopy, Western blot, double fluorescence labeling, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling staining also were used. RESULTS: VPA treatment decreased BBB disruption and brain edema, attenuated neural apoptosis, and improved neurobehavioral functions in EBI after SAH. Double fluorescence labeling indicated that matrix metallopeptidase 9 (MMP-9) was located predominately in neurons and endothelial cells. VPA upregulated the expression of HSP70, effectively decreased the expression and activity of MMP-9, and reduced claudin-5 and occludin degradation. Meanwhile, VPA also upregulated the expression of phosphorylated Akt and bcl-2. Both the anti-BBB disruption and antiapoptotic effects of VPA were abolished by quercetin. CONCLUSION: VPA prevented BBB disruption and alleviated neural apoptosis after SAH. The action of VPA appeared to be mediated though the HSP70/MMPs and HSP70/Akt pathways. ABBREVIATIONS: BBB, blood-brain barrierEBI, early brain injuryHSP, heat shock proteinMMP, matrix metalloproteinasePBS, phosphate-buffered salineSAH, subarachnoid hemorrhageTUNEL, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelingVPA, valproic acid.

Induction of autophagic cell death in the rat brain caused by iron.

BACKGROUND: The accumulation of iron in the brain is a hallmark of hemorrhagic stroke and several neurodegenerative diseases. Iron overload has been reported to induce brain injury through necrotic and apoptotic mechanisms. This study was taken to examine whether iron in the brain contributes to autophagic cell death. METHODS: Sprague-Dawley rats received an intracerebral ventricular injection of either ferrous chloride or saline. The expression levels of autophagic markers were measured by Western blot analysis. Immunofluorescent double labeling was used to identify the cell types expressing Beclin 1. Transmission electron microscopy was performed to examine the ultrastructural changes in neural cells 1 day after ferrous iron injection. RESULTS: Western blot analysis showed that the ratios of LC3-II to LC3-I and ATG5 levels were significantly upregulated at 6 hours and 1 day after ferrous iron injection. Beclin 1 expression was markedly elevated as early as 6 hours, reaching a peak at 24 hours and remaining elevated at 3 days after the injection. Beclin 1 immunoreactivity was located in both neurons and astrocytes under confocal microscopy. Induction of autophagic cell death was manifested by accumulation of autophagic vacuoles in the contralateral parietal cortex under transmission electron microscopy. CONCLUSIONS: Our data showed that increased ferrous iron levels in the brain induced autophagic cell death. These results also suggest that autophagy form of programmed cell death may be a mechanism of brain injury in iron overload disorders.