GluN2B-BDNF pathway in the cerebrospinal fluid-contacting nucleus mediates nerve injury-induced neuropathic pain in rats.

The present study was aimed to investigate the role of GluN2B-BDNF pathway in the cerebrospinal fluid-contacting nucleus (CSF-CN) in neuropathic pain. Intra-lateral ventricle injection of cholera toxin subunit B conjugated with horseradish peroxidase (CBHRP) was used to label the CSF-CN. Double-labeled immunofluorescent staining and Western blot were used to observe the expression of GluN2B and BDNF in the CSF-CN. Chronic constriction injury of sciatic nerve (CCI) rat model was used to duplicate the neuropathic pain. Pain behavior was scored to determine the analgesic effects of GluN2B antagonist Ro 25-6981 and BDNF neutralizing antibody on CCI rats. GluN2B and BDNF were expressed in the CSF-CN and their expression was up-regulated in CCI rats. Intra-lateral ventricle injection of GluN2B antagonist Ro 25-6981 or BDNF neutralizing antibody notably alleviated thermal hyperalgesia and mechanical allodynia in CCI rats. Moreover, the increased expression of BDNF protein in CCI rats was reversed by intra-lateral ventricle injection of Ro 25-6981. These results suggest that GluN2B and BDNF are expressed in the CSF-CN and alteration of GluN2B-BDNF pathway in the CSF-CN is involved in the modulation of the peripheral neuropathic pain.

Effectiveness, Safety and Risk Factors of Woven EndoBridge Device in the Treatment of Wide-Neck Intracranial Aneurysms: Systematic Review and Meta-Analysis.

OBJECTIVE: To assess the current efficacy, safety, and risk factors of the Woven EndoBridge (WEB) in treating wide-neck intracranial aneurysms. METHODS: We searched the PubMed, Ovid MEDLINE, and Embase databases between December 1, 2012 and June 30, 2018. Studies were included if they featured ≥5 patients undergoing WEB for wide-neck intracranial aneurysms, reported an angiographic or clinical outcome and risk factors, and were published after December 1, 2012. Major outcomes included initial or short-term complete and adequate occlusion. Secondary outcomes included treatment failure, recanalization, mortality, morbidity, and complication rates. A random-effect model was used to pool the data. To assess risk factors for short-term angiographic outcomes and the most common complications, we conducted subgroup analyses. RESULTS: We included 36 studies (1759 patients with 1749 aneurysms). The initial complete and adequate occlusion rates were 35% and 77%, respectively. The short-term (mean follow-up, 9.34 months) complete and adequate occlusion rates were 53% and 80%, respectively. Thromboembolism and recanalization had the highest occurrence (both 9%), followed by mortality (7%), morbidity (6%), failure (5%) and intraoperative rupture (3%). The following factors were related to higher short-term obliteration rates: unruptured status, in the anterior circulation, a medium neck (4-9.9 mm), newer-generation WEB, and treatment without additional devices. Ruptured status, anterior circulation, preoperative antiplatelet therapy, and newer-generation WEB were not significantly related to thromboembolism. CONCLUSIONS: WEB is safe and shows promising efficacy in treating wide-neck intracranial aneurysms. We preliminarily identified several risk factors for short-term angiographic outcomes.

Effects of continuous positive airway pressure therapy on plasma aldosterone levels in patients with obstructive sleep apnea: A meta-analysis.

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular diseases. Aldosterone was reported to be increased in patients with OSA and correlated with OSA severity. Many studies investigated the effect of continuous positive airway pressure (CPAP) therapy on plasma aldosterone concentrations (PAC) in OSA patients. The results, however, were inconsistent. In the present study, we aimed to evaluate the effects of CPAP therapy on PAC by performing a meta-analysis. Literature search was carried out in electronic databases including PubMed/Medline, Cochrane Library, Embase and Web of Science. Eligible full-text articles were identified, and important data were extracted. Pooled analysis was performed using the STATA12.0 and RevMan 5.2. Standardized mean difference (SMD) was calculated to estimate the treatment effects. A total of eight studies involving 219 patients were included for our final analysis. PAC was found unchanged after CPAP treatment in OSA patients (SMD=-0.36, 95% CI:-0.91 to 0.18, Z=1.32, P=0.19). Meanwhile, CPAP therapy showed no impact on PAC (SMD=-0.21, 95% CI:-0.85 to 0.42, Z=0.66, P=0.51) in a separate meta-analysis including 3 randomized controlled trials. In conclusion, the evidence for the use of CPAP therapy to decrease PAC in OSA patients is low, and further studies are still warranted.

A new method for evaluating regional cerebral blood flow changes: Laser speckle contrast imaging in a C57BL/6J mouse model of photothrombotic ischemia.

The present study aimed to improve the processing of data acquired from laser speckle contrast imaging (LSCI) to provide a standardization method to explore changes in regional cerebral blood flow (rCBF) and to determine the correlations among rCBF, cerebral ischemic lesion volume and microvascular density over time in a focal ischemic region. C57BL/6J mice were subjected to focal photothrombotic (PT) ischemia. rCBF was measured using LSCI at different time points before and after PT ischemia through an intact skull. Standardized rCBF (SrCBF), defined as the ratio of rCBF measured in the ipsilateral region of interest (ROI) to that in the corresponding contralateral region, was calculated to evaluate potential changes. In addition, the volume of the ischemic lesion and the microvascular density were determined using Nissl staining and immunofluorescence, respectively. The relationships among the ischemic lesion volume, microvascular density and SrCBF were analyzed over time. The results showed that the cortical rCBF measured using LSCI following PT ischemia in the C57BL/6J mice gradually increased. Changes in the cerebral ischemic lesion volume were negatively correlated with SrCBF in the ischemic region. Changes in the microvascular density were similar to those observed in SrCBF. Our findings indicate that LSCI is a practical technique for observing changes in murine cortical rCBF without skull opening and for analyzing the relationships among the ischemic lesion volume, microvascular density and SrCBF following focal cerebral ischemia. Preliminary results also suggest that the use of LSCI to observe the formation of collateral circulation is feasible.

The effects of morphine treatment on the NCAM and its signaling in the MLDS of rats.

Prolonged exposure to opiates induces a constellation of neuroadaptations, especially in the mesolimbic dopamine system (MLDS), which leads to alteration in the function of motivational circuitry. The neural cell adhesion molecule (NCAM) mediates cell-cell interactions and plays an important role in processes associated with neural plasticity. Moreover, it has been shown that NCAM were related to risk of alcoholism in human populations. Here, coimmunoprecipitation and western blotting were used to investigate whether morphine treatment induced alteration of the expression of NCAM or its signaling level in MLDS. The rats receiving escalating dose of morphine treatment were divided into three groups: morphine 1d, 3d and 5d group, which were injected subcutaneously with morphine hydrochloride for 1 day, 3 days and 5 days, respectively. Twelve hours after the last injection, animals were sacrificed and the tissues of ventral tegmental area (VTA), prefrontal cortex (PFC) and nucleus accumbens (NAc) were punched out to examine the expression of NCAM or its signaling level. The results showed that morphine treatment had no significant effect on the expression of NCAM, but downregulated the phosphorylation of NCAM-associated focal adhesion kinase (FAK) in the VTA and PFC of rats. In the NAc of rats, however, the expression of NCAM and its signaling were not altered significantly by morphine treatment. These results indicated that the downregulation of NCAM signaling in the VTA and PFC might be involved in the formation of morphine addiction.

Transient folate deprivation in combination with small-molecule compounds facilitates the generation of somatic cell-derived pluripotent stem cells in mice.

Induced pluripotent stem cells (iPSCs) can be propagated indefinitely, while maintaining the capacity to differentiate into all cell types in the body except for the extra-embryonic tissues. This iPSC technology not only represents a new way to use individual-specific stem cells for regenerative medicine but also constitutes a novel method to obtain large numbers of disease-specific cells for biomedical research. However, the low efficiency of reprogramming and genomic integration of oncogenes and viral vectors limit the potential application of iPSCs. Chemical-induced reprogramming offers a novel approach to generating iPSCs. In this study, a new combination of small-molecule compounds (SMs) (sodium butyrate, A-83-01, CHIR99021, Y-27632) under conditions of transient folate deprivation was used to generate iPSC. It was found that transient folate deprivation combined with SMs was sufficient to permit reprogramming from mouse embryonic fibroblasts (MEFs) in the presence of transcription factors, Oct4 and Klf4, within 25 days, replacing Sox2 and c-Myc, and accelerated the generation of mouse iPSCs. The resulting cell lines resembled mouse embryonic stem (ES) cells with respect to proliferation rate, morphology, pluripotency-associated markers and gene expressions. Deprivation of folic acid, combined with treating MEFs with SMs, can improve the inducing efficiency of iPSCs and reduce their carcinogenicity and the use of exogenous reprogramming factors.

Risk factors of ventilator-associated pneumonia in pediatric intensive care unit: a systematic review and meta-analysis.

OBJECTIVE: To identify risk factors of ventilator-associated pneumonia (VAP) in pediatric intensive care unit (PICU). METHODS: PubMed, Ovid, Web of Science, the Cochrane Library and references of retrieved articles were searched without language limitation. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by using both the Mantel-Haenszel fixed-effect and the DerSimonian-Laird random-effects models. RESULTS: Out of the 205 initially retrieved articles, 9 papers were included. All 4,564 patients were enrolled, including 213 patients with VAP and 4,351 patients without VAP. Among fourteen risk factors, six factors had statistical significances. Risk factors of VAP and its value of OR were as follows: genetic syndrome (OR =2.04; 95% CI: 1.08-3.86), steroids (OR =1.87; 95% CI: 1.07-3.27), reintubation or self-extubation (OR =3.16; 95% CI: 2.10-4.74), bloodstream infection (OR =4.42; 95% CI: 2.12-9.22), prior antibiotic therapy (OR =2.89; 95% CI: 1.41-5.94), bronchoscopy (OR =4.48; 95% CI: 2.31-8.71). CONCLUSIONS: Special methods of preventions should be taken in the light of risk factors of VAP in PICU so as to decrease the rate.

Proliferation and differentiation of neural stem cells co-cultured with cerebral microvascular endothelial cells after oxygen-glucose deprivation.

Various stem cells, including neural stem cells (NSCs), have been extensively studied in stroke models, but how to increase neuronal differentiation rate of NSCs remains unresolved, particularly in a damaged environment. The purpose of this study was to investigate the effects of cerebral microvascular endothelial cells (CMECs) on the neurogenesis of NSCs with or without oxygen-glucose deprivation (OGD). The NSCs acquired from primary culture were immunostained to prove cell purity. Survival and proliferation of NSCs were determined after the co-culture with CMECs for 7 days. After removing the CMECs, NSCs were randomly divided into two groups as follows: OGD and non-OGD groups. Both groups were maintained in differentiation culture for 4 days to evaluate the differentiation rate. Mouse embryo fibroblast (MEF) cells co-cultured with NSCs served as control group. NSCs co-cultured with CMECs had an increase in size (on the 7th day: 89.80±26.12 µm vs. 73.08±15.01 µm, P<0.001) (n=12) and number [on the 7th day: 6.33±5.61/high power objective (HP) vs. 2.23±1.61/HP, P<0.001] (n=12) as compared with those co-cultured with MEF cells. After further differentiation culture for 4 days, NSCs co-cultured with CMECs had an increase in neuronal differentiation rate in OGD and non-OGD groups, but not in the control group (15.16% and 16.07% vs. 8.81%; both P<0.001) (n=6). This study provided evidence that OGD could not alter the effects of CMECs in promoting the neuronal differentiation potential of NSCs. These findings may have important implications for the development of new cell therapies for cerebral vascular diseases.

Dramatic decrease of aortic longitudinal elastic strength in a rat model of aortic dissection.

BACKGROUND: This study aimed to evaluate thoracic aortic longitudinal elastic strength in a rat model of aortic dissection (AD). METHODS: Young Sprague Dawley rats were fed 0.25% ß-aminopropionitrile (BAPN). Biomechanical and biochemistry properties of the aorta were analyzed. Elasticity modulus, maximum stretching length, draw ratio, maximum load, maximum strength, and maximum extensibility were measured. RESULTS: More than one-half of BAPN-treated rats (52.9%) died of aortic rupture secondary to AD during the experiment. The diameter of the aneurysms was 6.33 ± 1.17 mm and the length was 9.33 ± 4.95 mm. The maximum diameter was significantly increased in BAPN-treated rats with AD (group B2) compared with rats without AD (group B1) and control group (group A) (P = 0.001 and P < 0.001, respectively), but was not different between group B1 and group A (P = 0.108). Thickness of media and initial area in aorta of BAPN-treated rats were significantly increased compared with control group (P = 0.001 and P < 0.001, respectively), but no difference in initial area was observed between group B1 and group B2 (P = 0.54). Maximum stretching length, draw ratio, maximum load, maximum strength, maximum extensibility, and elasticity modulus were dramatically decreased in group B2 compared with group B1 and group A (group B2 vs. group B1: P < 0.001; group B1 vs. group A: P < 0.001). CONCLUSIONS: We successfully established a rat model of AD with a high incidence of rupture and mortality. Examinations of strain and stress parameters as well as elasticity modulus of the dissected and the nondissected aorta help understand pathogenesis of AD.

Modifying the details of aspiration operation may contribute to the improvement of prognosis of patients with ICH.

AIM: The aim of the retrospective study was to compare the clinical efficacy of the traditional way of aspiration and the modified way of aspiration. MATERIAL and METHODS: Clinical data of total 159 patients with spontaneous intracerebral hemorrhage treated by traditional (group A, n=66) or modified (group B, n=93) way of aspiration (both combined with thrombolysis) were retrospectively analyzed. Reduction of clot volume in the first operation, rate of mortality and re-bleeding, complications, and long-term clinical outcomes of the two groups were compared. RESULTS: Twenty-five out of 159 patients (15.7%) died during in-hospital stay. The mortality and post-operation re-bleeding rate in group B (10.8% and 1.1%) were significantly lower than that in group A (22.7% and 9.1%), (P < 0.05). The BI scores of patients in group B (79.5±23.2) were significantly higher than that in group A (69.2±23.9), (P < 0.05). CONCLUSION: Our data suggested that modifying details of aspiration operation may contribute to the improved prognosis of ICH patients.

[Experimental study of implantation of neurotropin-3 modified olfactory ensheathing cells in experimental allergic encephalomyelitis].

OBJECTIVE: To investigate the therapeutic effect of neurotrophin-3 (NT-3) modified olfactory ensheathing cell (OEC) upon experimental allergic encephalomyelitis (EAE). METHODS: OEC-NT-3 gene engineering cell, constructed by neurotrophin-3 transinfecting GEC inducted by retrovirus, was transplanted into lateral ventricle. The migration and distribution were observed and compared with control group and OEC transplantation group. Then myelin repairing and axon regeneration were evaluated from conical somatosensory evoked potential (CSEP), function score and ultrastructural morphology. RESULTS: (1) OEC-NT-3 could survive, migrate within axons and spread diffusely away from the focus at Day 28 post-transplantation; (2) as compared with other two groups, more nerve fibers, better myelin repair and more distinct myelin structure were observed in the transgene group; (3) as compared with other two groups, the latent time was obviously shortened and the amplitude higher in the transplantation group (P < 0.05); (4) the transcription level of NT-3mRNA in the transgene group was significantly higher than the GEC group and the contrast group (212.32 +/- 16.14) x 10(-2) vs. (1.98 +/- 0.19) x 10(-2), (1.23 +/- 0.13) x 10(-2) (P < 0.01). CONCLUSION: OEC-NT-3 cell expresses NT-3 stably and effectively in EAE. It may contribute to the repairing of myelin and the regeneration of axon.

Extract of Ginkgo biloba promotes the expression of VEGF following subarachnoid hemorrhage in rats.

The study aimed to investigate the effect of extract of Ginkgo biloba (EGb) on the expression of vascular endothelial growth factor (VEGF) after subarachnoid hemorrhage (SAH). Wistar rats were divided into non-SAH, SAH, vehicle, EGb1 (low-dose), and EGb2 (high-dose) groups. VEGF mRNA and VEGF protein were measured from brain tissues. The expressions of VEGF mRNA in SAH and vehicle groups were enhanced 24 and 72 hr after the establishment of SAH. Increased VEGF positive cells were found in the brain tissues in SAH and vehicle groups. The expressions of VEGF mRNA and VEGF protein were further increased by the pretreatment of EGb. We concluded that EGb exerts protective effects on secondary cerebral ischemic injury after SAH via the promotion of the expression of VEGF.

Dynamic alterations of cerebral pial microcirculation during experimental subarachnoid hemorrhage.

The study aimed to investigate the involvement of cerebral microcirculation turbulence after subarachnoid hemorrhage (SAH). Wistar rats were divided into non-SAH and SAH groups. Autologous arterial hemolysate was injected into rat's cisterna magna to induce SAH. Changes of pial microcirculation within 2 h were observed. It was found that there were no obvious changes of the diameters, flow velocity, and fluid state of microvessels in non-SAH group. With the exception of rare linear-granular flow in A4 arteriole, linear flow was observed in most of the arterioles. There was no blood agglutination in any of the arterioles. After SAH, abnormal cerebral pial microcirculation was found. Spasm of microvessels, decreased blood flow, and agglutination of red blood cells occurred. Five minutes following the induction of SAH, the diameters of the arterioles and venules significantly decreased. The decreased diameters persisted for 2 h after cisternal injection. Decreased flow velocity of venules was found from 5 to 90 min after induction of SAH. Spasm of the basilar artery and increased brain malondialdehyde were also found after SAH. We concluded that cerebral microcirculation turbulence plays an important role in the development of secondary cerebral ischemia following SAH.

[Establishment of two human embryonic stem cell lines from cleavage arrested embryos].

OBJECTIVE: To determine whether cleavage developmentally retarded embryos have not cleaved during a 24 hour period could develop into blastocysts and produce hESC cell lines. METHODS: A total of 120 such embryos were cultured to blastocyst stage by sequential culture. Blastocysts formation rate and quality of blastocyst were detected under microscope. The relation between blastocyst formation rate and blastomere number, the fragment of blastomere and blastomere symmetry were analyzed by stepwise Logistical regression analysis. Inner cell masses (ICMs) were isolated by immunosurgery. Colonies derived from the ICMs were passed every 4 - 7 days and the derivatives were passaged and identified. RESULTS: A total of 22 blastocysts were obtained from 120 embryos. The blastulation rate was 18.7%. Early blatocyst, blastocyst, full blastocyst, expanded blastocyst, hatching blastocyst and hatched blastocyst accounted for 5.9%, 23.5%, 35.3%, 23.5%, 5.9%, and 5.9% respectively. The grade of ICM and trophoblast was mostly scored C or B. Blastocyst formation rate was related to cell number and blastomere symmetry but not fragment. Immunosurgery resulted in the formation of 7 ICMs and 3 primary colonies, which produced 2 cell lines. The cell lines satisfied the criteria that characterize pluripotent hESC cells. Undifferentiated cells were positive for AKP, SSEA-4, TRA-1-60, and TRA-1-81. It could continue to proliferate in vitro and form embryoid bodies when cultured in suspension. It had capability to form teratoma in SCID mice. Both cell lines had normal karyotypes after 45 and 34 passages respectively. CONCLUSIONS: Our results suggest that a subset of developmentally retarded embryos can form blastocysts and give rise to hESC cell lines.

[Study on distribution of neural stem cells in the brain of Alzheimer disease transgenic mice through caudal vein transplantation].

OBJECTIVE: To observe whether neural stem cells (NSCs) can successfully permeate into the brain through the blood-brain barrier (BBB) of Alzheimer disease (AD) transgenic mice and explore the methods of distribution and migration. METHODS: NSCs were isolated from 12-day-old fetal mice, cultured, labeled with enhanced green fluorescent protein (eGFP) and then transplanted into 10 AD transgenic mice and normal mice as controls through caudal vein. The mice were killed 48 h, 1 w, 2 w, and 4 w after transplantation respectively. The brains of the mice were made into continual frozen sections, the distribution and migration of the eGFP-labeled NSCs were studied under fluorescence microscope. RESULTS: At different time points after transplantation the eGFP-labeled NSCs were diffusely distributed in the brain: distributed around the blood vessels in the first 48 h, and then migrated gradually towards the hippocampus and cortex until 4 weeks later. There were no obvious abnormal complications occurring after transplantation. CONCLUSION: NSCs can successfully permeate into the brain through the BBB of AD transgenic mice, and migrate into the brain parenchyma gradually.

Observation of amyloid precursor protein cleavage and A beta generation in living cells by using multiphoton laser scanning microscopy.

OBJECTIVE: To investigate the proteolytic mechanism of amyloid precursor protein (APP) and to explore amyloid-beta (A beta) generation in living neurons. METHODS: DNA fragments were amplified by PCR or synthesized. The four fragments, CFP, 54bp, YFP and C99 were ligated into pcDNA3.0 vector to construct the recombinant plasmids pcDNA3.0-CFP-54bp-YFP and pcDNA3.0-CFP-54bp-YFP-C99. The SH-SY5Y cells were transiently transfected with pcDNA3.0-CFP-54bp-YFP or pcDNA3.0-CFP-54bp-YFP-C99. The expression of fusion gene was examined under a multiphoton laser scanning microscope. Fluorescence resonance energy transfer (FRET) was used to measure the beta cleavage and gamma cleavage of APP. A beta generation was confirmed by immunocytochemistry and multiphoton laser scanning microscopy. Cell viability was tested by MTT assay at different time points. RESULTS: (1) The double restriction endonuclease digestion and sequencing analysis confirmed the authenticity of the recombinant plasmids pcDNA3.0-CFP-54bp-YFP and pcDNA3.0-CFP-54bp-YFP-C99. (2) Blue and yellow fluorescences were detected in the transfected cells. (3) FRET occurred in pcDNA3.0-CFP-54bp-YFP-transfected cells but not in pcDNA3.0-CFP-54bp-YFP-C99-transfected cells. (4) A beta was produced in the pcDNA3.0-CFP-54bp-YFP-C99 transfected cells. (5) A beta-deposition was widespread in the cell. (6) Cell viability decreased along with the intracellular A beta deposition. CONCLUSION: C99 is important for the APP beta cleavage. A beta may be generated and deposited in cells at the early stage of Alzheimeros disease. Intracellular A beta accumulation brings deleterious effects on cells.

Effects of extract of ginkgo biloba on intracranial pressure, cerebral perfusion pressure, and cerebral blood flow in a rat model of subarachnoid haemorrhage.

The purpose of this study was to investigate in effect of extract of Ginkgo biloba (EGb) on cerebral blood perfusion in a subarachnoid haemorrhage (SAH) rat model. SAH lead to an increase in intracranial pressure and decrease in cranial perfusion pressure and regional cerebral blood flow in all groups. However, the intracranial pressure increases in EGb groups were less than that of the vehicle group (p < .01), whereas the reduction in cranial perfusion pressure and regional cerebral blood flow in the EGb group was less than that of the vehicle and SAH groups (p < .01). It was concluded that EGb attenuates the increase in intracranial pressure and reduction in cerebral blood perfusion after SAH.

Regionspecific survival and differentiation of mouse embryonic stem cell-derived implants in the adult rat brain.

Totipotent and regionally non-specified embryonic stem (ES) cells provide a powerful tool to understand mechanisms controlling stem cell differentiation in different regions of the adult brain. As the development capacity of ES cells in the adult brain is still largely unknown, we grafted small amounts of mouse ES (mES) cells into adult rat brains to explore the survival and differentiation of implanted mES cells in different rat brain regions. We transplanted the green fluorescent protein (GFP)-positive mES cells into the hippocampus, septal area, cortex and caudate nucleus in rat brains. Then the rats were sacrificed 5, 14 and 28 d later. Of all the brain regions, the survival rate of the transplanted cells and their progeny were the highest in the hippocampus and the lowest in the septal area (P<0.01). The grafted ES cells could differentiate into nestin-positive neural stem cells. Nestin-positive/GFP-positive cells were observed in all brain regions with the highest frequency of nestin-positive cells in the hippocampus and the lowest in the medial septal area (P<0.01). mES cells differentiated into end cells such as neurons and glial cells in all transplantation sites in recipient brains. In the hippocampus, the ES cells differentiated into neurons in large amounts. These results demonstrate that only some brain regions permit survival of mES cells and their progeny, and form instructive environments for neuronal differentiation of mES cells. Thus, because of region specific presence of microenvironmental cues and their environmental fields, the characteristics of the recipient tissue were considerably important in formulating cell replacement strategies for neural disorders.