Clinical significances and features of prompt brain CT scan after intracranial artery stenting: analysis of 501 cases.

Cerebral hemorrhage is a serious complication of intracranial artery stenting that could be fatal without timely identification and treatment. Prompt brain CT scan would help to evaluate whether cerebral hemorrhage occurs, however, the diverse features of the CT scan immediately after stenting could influence the judgement sometimes. Therefore, we analyzed and summarized these features to help to determine the clinical significance of these CT features. The prompt CT features after stenting were classified into three types. Type I indicates that no high-density shadows. Type II indicates that high-density shadows scattered in the infarct areas and/or subarachnoid spaces without mass effect. Type III indicates high-density shadows scattered in and/or out of the infarct areas and/or subarachnoid space with obvious mass effects. Based on this classification, the patients in both Type I and II would continue the double anti-platelet treatment (DAPT) and anti-coagulation treatment, while the later need closer monitoring. However, patients in Type III must immediately withdraw the DAPT and anti-coagulation treatment with close monitoring and surgical intervention was needed when necessary. Nineteen (3.79%) patients were classified into Type III, and 5 (1.00%) of the 19 were accepted surgical intervention. Two of these patients died (0.40%). The prompt CT scan timely distinguishing the cerebral hemorrhage was necessary after intracranial artery stent angioplasty. Additionally, based on the different prompt CT features to take different therapeutic strategies after stenting would achieve better outcomes for ischemic stroke or transient ischemic stroke (TIA) patients underwent intracranial artery endovascular therapy.

Safety and Efficacy of Wingspan Stenting for Severe Symptomatic Atherosclerotic Stenosis of the Middle Cerebral Artery: Analysis of 278 Continuous Cases.

OBJECTIVE: Our objective is to investigate the safety and long-term efficacy of the Wingspan stent (Boston Scientific, Natick, MA, USA) for treating severe atherosclerotic stenosis of the middle cerebral artery (MCA). METHODS: A total of 278 consecutive patients from our stroke database with clinical symptoms within the prior 90 days and intracranial atherosclerotic stenosis of 70% or above of the MCA were enrolled in this study between September 2012 and November 2014, and these patients were followed until the end of June 2015. The endpoint events included any stroke or death within 30 days after stenting and any subsequent ipsilateral ischemic stroke. RESULTS: Among the 278 enrolled patients, 277 patients (99.6%) successfully underwent stenting. The mean rate of stenosis decreased from 82.5 ± 7.9% to 9.0 ± 3.2% following treatment. Within 30 days after stenting, 12 patients (4.3%) experienced endpoint events, including 8 cases (2.9%) of hemorrhagic stroke and 4 cases (1.4%) of ischemic stroke; 2 perioperative deaths occurred. During 8-33 months of follow-up, 19 patients developed endpoint events. The 1- and 2-year endpoint event rates were 5.8% (95% confidence interval [CI], 5.0%-15.7%) and 7.2% (95% CI, 4.3%-10.1%), respectively. CONCLUSIONS: From this study, we can conclude that the treatment of severe symptomatic atherosclerotic stenosis of the MCA using the Wingspan stent was safe and effective and that the long-term stroke recurrence rate after stenting was low.

Association of CYP2C19 Polymorphisms with the Clinical Efficacy of Clopidogrel Therapy in Patients Undergoing Carotid Artery Stenting in Asia.

The CYP2C19 gene plays a detrimental role in the metabolism of clopidogrel. This study aimed to investigate the association between CYP2C19 polymorphisms and the clinical efficacy of clopidogrel therapy in patients who have undergone carotid artery stenting (CAS). CYP2C19 genotype screening was performed on 959 ischemic stroke patients. Of these patients, 241 who had undergone CAS were enrolled in the study. They were all followed up for 1 year after stent surgery, and the primary clinical end-points were ischemic events. The frequencies of the CYP2C19*2 and *3 alleles among the 959 patients were 31.80% and 5.06%, respectively. Regarding the 241 participants who had undergone CAS, multivariate Cox regression analysis showed that the CYP2C19 loss-of-function (LOF) alleles (*2 and *3) were risk factors for post-CAS prognosis. Within 1 year of follow-up, the patients carrying the CYP2C19 LOF alleles were more likely to experience ischemic events than those carrying none. The occurrence of ischemic events did not significantly differ between the *2 and *3 allele carriers. Our results suggest that CYP2C19 LOF alleles (*2 and *3) significantly impact the prognosis of patients on clopidogrel therapy after CAS and that the CYP2C19*2 and CYP2C19*3 alleles have the same effects on prognosis.

A polymorphism (-455G>A) in the ß-fibrinogen gene is associated with an increased risk of cerebral infarction in the Chinese population: A meta-analysis.

BACKGROUND: Previous studies have investigated the association between a polymorphism (-455 G>A) in the ß-fibrinogen gene and the risk of cerebral infarction. However, these results are controversial. To shed light on these inconclusive findings, we performed a meta-analysis of studies relating the ß-fibrinogen genetic polymorphism (-455 G>A) to the risk of cerebral infarction. METHODS: We identified literature published before July 2013 by searching PubMed, EMBASE, ISI Web of Science, the Chinese National Knowledge Infrastructure database (CNKI) and the Wanfang database in China and by reviewing the references of retrieved articles. We included studies that reported odds ratio (OR) with 95% confidence interval (CI) for the association between the ß-fibrinogen genetic polymorphism and cerebral infarction risk. Publication bias was tested by a funnel plot, and the OR of all studies were combined dependent on the results of the heterogeneity tests among the individual studies. The software Review Manager (Version 5.2) was used for meta-analysis. RESULTS: Twenty independent case-control studies containing 9477 subjects were included. Our results showed that the -455 G>A polymorphism in the ß-fibrinogen gene was associated with the increased risk of cerebral infarction [(AA+GA) vs. GG, OR=1.17, 95%CI: 1.04-1.31, p=0.008; A vs. G, OR=1.12, 95%CI: 1.01-1.23, p=0.03] in the Chinese population by a meta-analysis. However, we did not find this association in the Caucasian population [(AA+GA) vs. GG, OR=0.99, 95%CI: 0.87-1.11, p=0.84; A vs. G, OR=0.97, 95%CI: 0.84-1.13, p=0.73, respectively]. CONCLUSION: The results of our meta-analysis indicate that the -455 G>A polymorphism in the ß-fibrinogen gene is a susceptibility marker of ischemic cerebral infarction in the Chinese population.

Serum Brain-derived neurotrophic factor levels in post-stroke depression.

BACKGROUND: Depression is a frequent mood disorder that affects around a third of stroke patients and has been associated with poorer outcome. Our aim was to determine whether there is a relationship between serum Brain-derived neurotrophic factor (BDNF) levels and post-stroke depression (PSD). METHODS: Two hundred and sixteen ischemic stroke patients admitted to the hospital within the first 24h after stroke onset were consecutively recruited and followed up for 3 months. Based on the symptoms, diagnoses of depression were made in accordance with DSM-IV criteria for post-stroke depression at day 90. Enzyme-linked immunosorbent assay (ELISA) was used to measure serum levels of BDNF at admission. Multivariate analyses were performed using logistic regression models. RESULTS: In our study, 59 patients (27.3%) were diagnosed as having major depression at 3 months. Patients with major depression showed lower levels of serum BDNF [8.1 (5.6-9.4) vs. 13.7 (10.4-16.5)ng/ml, P<0.0001] at admission. In multivariate analyses, serum BDNF was an independent predictor of PSD at 3 months [odds ratio (OR): 0.79(0.72-0.87), P=0.003]. Serum levels of BDNF≤10.2ng/ml were independently associated with post-stroke (OR, 11.5; 95% CI, 5.6-23.4, P<0.0001), after adjustment for possible variables. CONCLUSION: The present study demonstrates a strong relationship between serum BDNF levels at admission and the development of PSD within 3 months. Further studies are necessary to confirm this association, which may open the way to the proposal of new therapeutic options.

Plasma levels of glutamate during stroke is associated with development of post-stroke depression.

BACKGROUND: Depression is a frequent mood disorder that affects around 33% of stroke patient. Our aim was to test the possible association between plasma glutamate and the development of post-stroke depression (PSD) in Chinese patients. METHODS: The subjects were first-ever acute ischemic stroke (AIS) patients who were hospitalized during the period from November 2011 to September 2013. Clinical information and stroke severity was collected at admission. Neurological and neuropsychological evaluations were conducted at the 3-month follow-up. Plasma glutamate levels were analyzed at baseline using liquid chromatography followed by tandem mass spectrometry. Glutamate oxaloacetate transaminase (GOT), glutamate-pyruvate transaminase (GPT) and blood markers were also tested. Multivariate analyses were performed using logistic regression models. RESULTS: During the study period, 209 patients were included in the analysis. Seventy patients (33.5%) were diagnosed as having major depression at 3 month. Patients with major depression showed higher levels of plasma glutamate [299 (235-353) vs. 157 (108-206) µM, P<0.0001] and lower GOT [14 (11-20) vs. 21 (15-32)U/L, P<0.0001] at admission. In multivariate analyses, plasma glutamate and GOT were independent predictors of PSD at 3 months [odds ratio (OR): 1.03 (1.02-1.04), P<0.0001; 0.84 (0.75-0.97), P=0.003]. Plasma levels of glutamate >205 µM were independently associated with PSD (OR, 21.3; 95% CI, 8.28-67.36, P<0.0001), after adjustment for possible variables. CONCLUSION: The present study demonstrates a strong relationship between plasma glutamate and GOT levels at admission and the development of PSD within 3 months. Further studies are necessary to confirm this association, which may open the way to the proposal of new therapeutic options.

Cloning, expression, and functional characterization of the rat Pax6 5a orthologous splicing variant.

Pax6 functions as a pleiotropic regulator in eye development and neurogenesis. Its splice variant Pax6 5a has been cloned in many vertebrate species including human and mouse, but never in rat. This study focused on the cloning and characterization of the Pax6 5a orthologous splicing variant in rat. It was cloned from Sprague-Dawley rats 10 days post coitum (E10) by RT-PCR and was sequenced for comparison with Pax6 sequences in the GenBank by BLAST. The rat Pax6 5a was revealed to contain an additional 42 bp insertion at the paired domain. At the nucleotide level, the rat Pax6 5a coding sequence (1,311 bp) had a higher degree of homology to the mouse (96% identical) than to the human (93% identical) sequence. At the amino acid (aa) level, rat PAX6 5a shares 99.8% identity with the mouse sequence and 99.5% with the human sequence. The splice variant is preferentially expressed in the rat E10 embryonic headfolds and not in the trunk of neurula. Its effects on the proliferation of rat mesenchymal stem cells (rMSCs) were preliminarily evaluated by the MTT assay. Both pLEGFP-Pax6 5a-transfected cells and pLEGFP-Pax6-transfected cells exhibited a similar growth curve (P>0.05), suggesting that the Pax6 5a has a similar effect on the proliferation of rMSCs as Pax6.

Association of endothelial lipase genetic polymorphism with lacunar infarction in a Chinese population.

INTRODUCTION: This study sought to investigate the correlation between the single nucleotide polymorphism (SNP) rs9958947C>T in the endothelial lipase (LIPG) gene promoter and lacunar infarction in the Han population in China. MATERIALS AND METHODS: A case-control method was applied in this study, which included 378 patients with lacunar infarction in the patient group and 404 healthy individuals who received a routine physical examination in the control group. The polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods were used to detect the SNP (rs9958947) in the LIPG promoter for the two groups. RESULTS: The T allele frequency (51.32%) and CT+TT genotype frequency (77.78%) in the patient group were significantly higher than those in the control group (43.32% and 66.34%, respectively). Comparison of the T allele frequency and CT+TT genotype frequency between the two groups showed statistically significant differences. Logistic regression analysis showed that the T allele, male, smoking, hypertension, hyperlipidemia and diabetes were independent risk factors for lacunar infarction in the Han population in China. CONCLUSION: Therefore, we concluded that SNP rs9958947 in the LIPG gene promoter is associated with the incidence of lacunar infarction.

Dendritic development of hippocampal CA1 pyramidal cells in a neonatal hypoxia-ischemia injury model.

It is believed that neonatal hypoxia-ischemia (HI) brain injury causes neuron loss and brain functional defects. However, the effect of HI brain injury on dendritic development of the remaining pyramidal cells of the hippocampus and the reaction of contralateral hippocampal neurons require further studies. The Morris water maze and Golgi-Cox staining were used to evaluate the learning and memory and dendritic morphology of pyramidal cells. The results of Golgi-Cox staining showed CA1 pyramidal neurons of HI injury models with fewer bifurcations and shorter dendrite length than the naive control group. The density of dendritic spines of hippocampal CA1 pyramidal neurons was significantly lower in the HI brain injury group than in controls. With respect to hippocampal function, the HI brain injury group presented cognitive deficits in the reference memory task and probe trail. In the HI group, the pyramidal cells of left hippocampus that did not experienced ischemia but did experience hypoxia had more complex dendrites and higher density of spine than the HI injury side and control. The functional implementation of injured hippocampus might depend mainly on the hypertrophy of contralateral hippocampus after HI brain injury. Corticosterone can partially prevent the hippocampal pyramidal cells from HI injury and reduce the difference of the bilateral hippocampus pyramidal cells, but there was no improvement in learning and memory.

Expression of P2X5 receptors in the rat, cat, mouse and guinea pig dorsal root ganglion.

P2X receptors are ATP-gated cationic channels composed of seven cloned subunits (P2X(1 -7)). P2X(3) homomultimer and P2X(2/3) heteromultimer receptors expressed by primary afferent dorsal root ganglion (DRG) neurons are involved in pain processing. The aim of the study was to investigate the expression of the P2X(5) receptor subunit in DRG in different species including mouse, rat, cat and guinea pig. Immunohistochemistry showed that P2X(5) receptors exhibited low levels of immunostaining in rat DRG, but high levels in mouse and guinea pig. Only a few neurons were immunoreactive for P2X(5) receptors in cat. In mouse DRG, the P2X(5) receptor was expressed largely by medium-diameter neurons (42.9 %), less in small (29.3 %) and large (27.8 %) neurons. In contrast, in the guinea pig DRG, P2X(5) receptor expression was greatest in small-diameter (42.6 %), less in medium- (36.3 %) and large-diameter (21.1 %) neurons. Colocalization experiments revealed that, in mouse DRG, 65.5, 10.9 and 27.1 % of P2X(5) receptors were immunoreactive for NF-200, CGRP and calbindin, while only a few P2X(5)-immunoreactive (IR) neurons were coexpressed with IB4 or with NOS. In guinea pig DRG, a total of 60.5 and 40.5 % of P2X(5)-IR neurons were coexpressed with IB4 or with CGRP, while 20.3 and 24.5 % of P2X(5) receptors were coexpressed with NF-200 or with NOS. Only a few P2X(5)-IR neurons were coexpressed with calbindin in guinea pig DRG. It will be of great interest to clarify the relative physiological and pathophysiological roles of P2X(5) receptors.

Functional response of hippocampal CA1 pyramidal cells to neonatal hypoxic-ischemic brain damage.

Perinatal hypoxic-ischemic (H-I) is a major cause of brain injury in the newborn. The hippocampus is more sensitive to H-I injury than the other brain regions. It is believed that H-I brain damage causes a loss of neurons in the central nervous system. The patterns of neuronal death include apoptosis and necrosis. With regard to the responses of neurons, the neural functional changes should be earlier than the morphologic changes. The aim of the present study is to evaluate the electrophysiological characteristics and the synaptic transmission functions. Seven-day-old Sprague-Dawley rat pups were randomly divided into sham operation and H-I groups. The patch clamp, immunohistochemistry and Western blotting techniques were used to achieve this objective. The results of the study showed a decrease in neuronal excitability and a significant increase in the frequency of spontaneous excitatory postsynaptic currents and the duration of EPSCs in the CA1 pyramidal cells of H-I brain damage rats. The glutamate transporter subtype 1 (GLT-1) expression level of the hippocampal CA1 area in the H-I group was decreased compared with the control. There was no difference in the amplitude of excitatory postsynaptic currents and should be no difference in the expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR), N-methyl-D-aspartate receptor (NMDAR) and synaptophysin between the control and H-I brain injury group. These results revealed that changes of electrophysiological characteristics and synaptic functions occur instantly after H-I brain damage in the hippocampal pyramidal cells of neonatal rats. The failure to eliminate glutamate should be one of the important factors of excitotoxicity injury on hippocampal CA1 pyramidal cells, while neuronal excitation was not increased in the H-I brain injury model.

Effect of hypobaric hypoxia on the P2X receptors of pyramidal cells in the immature rat hippocampus CA1 sub-field.

PRIMARY OBJECTIVE: This study was designed to evaluate the effect of hypobaric hypoxia (HH) on the function and expression of P2X receptors in rat hippocampus CA1 pyramidal cells. RESEARCH DESIGN: The functional changes of P2X receptors were investigated through the cell HH model and the expressional alterations of P2X receptors were observed through the animal HH model. METHODS AND PROCEDURE: P2X receptors mediated currents were recorded from the freshly dissociated CA1 pyramidal cells of 7-day-old SD rats by whole cell patch clamp recording. The expression and distribution of P2X receptors were observed through immunohistochemistry and western blot at HH 3-day and 7-day. MAIN OUTCOMES AND RESULTS: In acute HH conditions, the amplitudes of ATP evoked peak currents were decreased compared to control. The immunohistochemistry and western blot results reflected there was no change in P2X receptors expression after 3 days HH injury, while P2X receptors expression was up-regulated in response to 7 days HH injury. CONCLUSIONS: These findings supported the possibility that the function of P2X receptors was sensitive to HH damage and long-term function decrease should result in the expression increase of P2X receptors.

[Change of Rho kinase activity in brain tissue in high altitude condition and its relationship with high altitude cerebral edema: experiment with rats].

OBJECTIVE: To observe the change of Rho kinase activity in brain tissue in the high altitude condition and its relationship with blood brain barrier permeability and high altitude cerebral edema (HACE), and to explore the pathological mechanism of HACE. METHODS: 30 Wistar rats were divided randomly into 3 equal groups, high altitude (HA) group put in low pressure cabin mimicking high altitude of 7000 m for 24 hr and then gradually exposed to higher pressure until the normal pressure, fasudil group undergoing intraperitoneal injection of fasudil hydrochloride 30 mg/kg, a Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor, and then treated as the HA group, and normal control group (HC group). Five rats from each were decapitated with their brains taken out. The ratio of dry brain weight and wet brain weight was calculated. Western blotting was used to detect the expression of ROCK. Another 5 rats from each groups underwent injection of sodium fluorescein into the caudal vein and then the rats were decapitated to examine the natrium (sodium) fluorescence index (NaFI) of the central brain slice so as to observe the blood brain barrier permeability. RESULTS: The ROCK activity in brain tissue, ratio of dry and wet brain weight and NaFI of the HA group were significantly higher than those of the HC group (all P<0.001), and ROCK activity in brain tissue, ratio of dry and wet brain weight and NaFI of the fasudil group were all significantly lower than those of the HA group (all P<0.001) and not significantly different from those of the HC group (all P>0.05). CONCLUSIONS: ROCK in brain tissue is activated in high altitude condition, which may play a key role in the development of HACE.

[Small interfering RNA (siRNA) targeting vascular endothelial growth factor inhibits vascular leakage in brain of rats exposed to high altitude].

OBJECTIVE: To observe the change of expression of vascular endothelial growth factor (VEGF) and vascular leakage in the brain of rats exposed to high altitude with siRNA targeting vascular endothelial growth factor and explore the pathological mechanism and preventive approach of high altitude cerebral edema (HACE). METHODS: Fifty male Wistar rats were divided randomly into normal control group (Ncon), high altitude control group (Hcon), intraventricular normal saline control group (Scon), intraventricular siRNA group (CVI) and intravenous siRNA group (IVI). Rats in Ncon were raised normally. Rats in Hcon, Scon, CVI and IVI pretreated with intravenous injection of normal saline, intraventricular injection of normal saline, intraventricular injection of siRNA and intravenous injection of siRNA respectively were exposed to a low-pressure cabin mimicking a high altitude of 7000 m for 24 h. The ratio of dry and wet brain weight was calculated and the sodium fluorescein leakage calculated to evaluate the cerebral edema and the blood brain barrier permeability. Also the real-time quantitative RT-PCR was employed to detect the expression of VEGF mRNA and the Western blot the expression of VEGF. RESULTS: Compared with rats in NC, high altitude exposure led to a significant increase in the levels of VEGF mRNA (from 21.6 + or - 3.5 K copies/microg to 36.3 + or - 3.9 K copies/microg, P < 0.01) and protein (from 48 + or - 0.09 to 0.77 + or - 0.12, P < 0.01) in rat brain and fluorescence intensity of sodium fluorescein increased significantly (from 548 + or - 48 rfu/mg to 674 + or - 32 rfu/mg, P < 0.01). Intravenous injection of siRNA targeting to VEGF caused no significant change of expression VEGF mRNA and protein and fluorescence intensity of sodium fluorescein in rat brain (P > 0.05, respectively). While compared with rats in HC, intraventricular injection of siRNA targeting to VEGF caused the significant reduction of expression of VEGF mRNA (from 36.3 + or - 3.9 to 19.9 + or - 4.3, P < 0.01) and protein (from 0.77 + or - 0.12 to 0.44 + or - 0.13, P < 0.01) and fluorescence intensity of sodium fluorescein (from 674 + or - 32 rfu/mg to 542 + or - 77 rfu/mg, P < 0.05) in rat brain. There were no significant change in the ratio of dry and wet brain weight among five groups. CONCLUSION: VEGF may play a key role in the pathologic process of HACE. Intraventricular injection of siRNA targeting to VEGF inhibits the expression of VEGF and prevent the high altitude-induced vascular leakage. These findings might provide a basis for new preventive approaches of cerebral edema.

Mechanisms of orexin A-evoked changes of intracellular calcium in primary cultured cortical neurons.

We have investigated the effect of orexin A on the intracellular free calcium concentration ([Ca2+]i) in primary cultured cortical neurons and explored the exact mechanisms of orexin A-evoked changes of [Ca2+]i. In the present study, changes of [Ca2+]i induced by orexin A in primary cultured cortical neurons were first detected by confocal laser scanning microscopy using Ca2+-sensitive dye fluo-4 as a novel calcium fluorescent probe. Our results showed that 1-0.1 microM orexin A induced the increase in [Ca2+]i in cortical neurons. The increase in [Ca2+]i by acute application of orexin A occurred in a dose-dependent manner. Orexin A-induced increase in [Ca2+]i was not observed under the condition of Ca2+-free Dulbecco's modified Eagle's medium. Pretreatment on the cells with 1 microM thapsigargin did not block orexin A-evoked response. These findings first illuminated the fact that orexin A-induced increase in [Ca2+]i may be mainly from extracellular calcium influx in cortical neurons.

[Olfactory ensheathing cells enhance functional recovery of injured sciatic nerve].

OBJECTIVE: To investigate the effect of olfactory ensheathing cells (OECs) on functional recovery after sciatic nerve injury. METHODS: Upon silicone-tubulization of transected sciatic nerve in 30 adult rats. Thirty rats were divided into two groups(SAL group and OECs group); saline and OECs were injected into the silicone chamber in SAL group and in OECs group respectively. The status of functional recovery of injured sciatic nerve was observed by electrophysiological analysis, axon morphometry analysis. RESULTS: In OECs group on the 30th and the 90th days after sciatic nerve transection: 1. The latent period of CMAP shortened by 0.60 ms and 0.56 ms; the nerve conduction velocity promoted by 6.42 m/s and 5.36 m/s; the amplitude enhanced by 3.92 mv and 5.84 mv, respectively; 2. The HRP positive cells in lateral nucleus of spinal anterior horn increased by 11.63% and 25.01%; 3. The number of nerve fibers increased by 1,047/mm2 and 1,422/mm2 and the thickness of myelim sheath increased by 0.43 micron and 0.63 micron, respectively. CONCLUSION: The olfactory ensheathing cells are capable of promoting the functional recovery after peripheral nerve injury.