Oxygen Vacancy-Enhanced Centrosymmetric Breaking of SrFeO3- x for Piezoelectric-Catalyzed Synthesis of H2O2.

Normally, only noncentrosymmetric structure of the materials can potentially be piezoelectric. Thus, it is limited in the field of piezoelectricity for the centrosymmetric structure of the material. In this work, the performance of piezoelectricity is successfully achieved from centrosymmetric SrFeO3- x by modulating oxygen vacancies, which have a surface piezoelectric potential up to 93 mV by using Kelvin-probe force microscopy (KPFM). Moreover, the piezoelectric effects of SrFeO3- x are also evaluated by piezoelectric catalytic effect and density functional theory calculations (DFT). The results show that the piezo-catalytic degradation of tetracycline reaches 96% after 75 min by ultrasonic mechanical vibration and the production of H2O2 by SrFeO3- x piezoelectric synthesis could reach 1821 µmol L-1. In addition, the DFT results indicate that the intrinsic effect of oxygen vacancies effectively promotes the adsorption and activation of O2 and H2O as well as intermediates and improves the piezoelectric catalytic activity. This work provides an effective basis for realizing the piezoelectricity of centrosymmetric materials and regulating the development of piezoelectric catalytic properties.

Enhanced Visible-Photocatalytic Activities in Strong Acids and Strong Alkalis of Flexible Iron-SrTiO3 Nanofibrous Membranes.

Traditional SrTiO3 (STO) materials have high brittleness and poor deformation resistance. In this work, macroscopically flexible iron-doped SrTiO3 (SFTO) nanofibrous membranes were prepared by electrospinning and calcination, which can be easily isolated and can maintain integrity to recycle as photocatalysts. Moreover, the SFTO nanofibrous membranes showed enhanced photocatalytic performance under strong acids (pH = 2) and strong alkalis (pH = 12). The SFTO nanofibrous membranes increased the catalytic rate of Congo red (CR) dye by about 10 times in visible light. The mechanism of photocatalytic activity enhancement was discussed by the combined effects of hydroxyl radicals and superoxide radicals. The successful preparation of SFTO nanofibrous membranes has offered a simple and economical approach to photocatalysis as well as environmental remediation.

MicroRNA­494 promotes the proliferation and migration of human glioma cancer cells through the protein kinase B/mechanistic target of rapamycin pathway by phosphatase and tensin homolog expression.

The aim of the present study was to analyze the possible association between microRNA­494 (miR­494) and cell proliferation in glioma cancer. Firstly, the expression of miR­494 was revealed to be upregulated in patients with glioma, compared with the normal group. Next, anti­miR­494 mimics were used to decrease the expression of miR­494 in glioma cancer cells, which subsequently induced apoptosis, and inhibited cell growth and migration. Downregulation of miR­494 expression induced phosphatase and tensin homolog (PTEN) and suppressed the protein kinase B/mechanistic target of rapamycin pathway (Akt/mTOR) pathway in glioma cancer cells. By contrast, overexpression of miR­494 by miR­494 mimics promoted cell growth and migration, and suppressed the apoptosis of glioma cancer via the Akt/mTOR pathway by PTEN expression. Furthermore, a PTEN inhibitor was used to attenuate the function of miR­494 in glioma cancer autophagy through Akt/mTOR pathway. The promotion of PTEN promoted the function of anti­miR­494 on glioma cancer cell growth through Akt/mTOR pathway. Collectively, these results demonstrate that the effect of miRNA­494 on the proliferation and migration glioma cancer cells was mediated through Akt/mTOR pathway by PTEN expression.

In situ precise electrospinning of medical glue fibers as nonsuture dural repair with high sealing capability and flexibility.

PURPOSE: In this work, we propose an in situ precise electrospinning of medical glue fibers onto dural wound for improving sealing capability, avoiding tissue adhesion, and saving time in dural repair. METHODS: N-octyl-2-cyanoacrylate, a commercial tissue adhesive (medical glue), can be electrospun into ultrathin fibrous film with precise and homogeneous deposition by a gas-assisted electrospinning device. RESULTS: The self-assembled N-octyl-2-cyanoacrylate film shows high compactness and flexibility owing to its fibrous structure. Simulation experiments on egg membranes and goat meninges demonstrated that this technology can repair small membrane defects quickly and efficiently. CONCLUSION: This method may have potential application in dural repair, for example, working as an effective supplementary technique for conventional dura suture.

[Research Progress on role of Abnormal Tryptophan Metabolism in Immune Thrombocytopenia].

Immune thrombocytopenia (ITP) is a common acquired autoimmune hematological disorders. Platelet autoantibodies lead to the decrease of platelet production and (or) increase of its destruction. The latest researches showed that the abnormal tryptophan metabolism mediated by indoleamine-2, 3-dioxygenase(IDO) is related with the pathogenesis of ITP. The patients with ITP show less expression of IDO, reduction of Treg cells and increase of autoreactive T cells and autoantibodies. CTLA-4-Ig can improve the expression of IDO in the patients with ITP, which also can inhibit the proliferation and activation of self-reactive T cells. Thus, clarifying the abnormal tryptophan metabolism mediated by IDO may provide a new idea for improving the understand of the pathogenesis and treatment of ITP. This review focuses on reasearch progress of the tryptophan metabolism mediated by IDO and ITP.

Microsurgical treatment for central gyrus region meningioma with epilepsy as primary symptom.

BACKGROUND: The objective of this article was to investigate the operation outcome, complications, and the patient's quality of life after surgical therapy for central gyrus region meningioma with epilepsy as the primary symptom. METHODS: All patients get at least 6 months of follow-up (range, 6-34 mo) after surgery. They underwent preoperative magnetic resonance imaging and video electroencephalography, and their clinical manifestations, imaging characteristics, microsurgical methods, and prognosis were retrospectively analyzed. RESULTS: The meningioma was located in the front and back of the central sulcus vein in 3 and 2 patients, respectively; in the compressed precentral gyrus and central sulcus vein in 3 patients; and in the precentral gyrus and postcentral gyrus each in 1 patient; beside the right sagittal sinus and invaded a thick draining vein on the brain surface in 1 patient and beside the right sagittal sinus and close to the precentral gyrus in 2 patients; invaded the superior sagittal sinus in 8 patients; crossed the cerebral falx and compressed cortex gyrus veins in 1 patient; invaded duramater and irritated skull hyperplasia in 3 patients; invaded duramater and its midline infiltrated into the superior sagittal sinus, was located behind the precentral gyrus, and enveloped the central sulcus vein. They were resected and classified by Simpson standards: 17 of the 26 patients had grade I, 6 patients had in grade II, and 3 patients had in grade III. CONCLUSIONS: Resection of central gyrus region meningioma by microsurgical technique avoids injury to the cerebral cortex, central sulcus vein, and other draining veins. Microsurgery improves the total resection rate, reduces recurrence rate, and lowers disability or death rate.

Primary cerebellar paraganglioma: a pediatric case report and review of the literature.

BACKGROUND: Only four cases of primary intracerebellar paragangliomas have been reported in the literature to date. Because of its rarity, primary intracerebellar paraganglioma still presents a diagnostic challenge for both radiologists and neurosurgeons, and the optimal therapeutic modality is still debatable for its hypervascularity and location. PATIENTS: We report a 16-year-old boy with pathology-proven primary intracerebellar paraganglioma who presented with dull headache, dizziness, and gait disturbance, and underwent gross total resection. Further, we review all reported cases of primary intracerebellar paraganglioma in the English literature and discuss its clinical profile, neuroradiological features, and treatment modalities. RESULTS: His symptoms improved following tumor removal without radiotherapy, and postoperative neuroimaging thirteenth months after surgery showed no recurrence. In the literature, all four patients were stable in the follow-up period including three with complete resection and one with partial resection plus adjuvant radiotherapy. CONCLUSION: Surgical resection is the treatment modality most often used for primary intracerebellar paraganglioma; radiation therapy may be used when there is residual tumor or recurrence. Angiography may help to clarify the vessel architecture for reducing intraoperative bleeding when primary intracerebellar paraganglioma is considered.

Pediatric isolated oculomotor nerve schwannoma: a new case report and literature review.

Isolated schwannoma arising from the oculomotor nerve occurs rarely, and only 12 children with oculomotor nerve schwannoma without neurofibromatosis have been sufficiently documented. This article presents a 3-year-old boy in which a large isolated parasellar oculomotor nerve schwannoma causing parent nerve dysfunction. Complete resection of the tumor was achieved via a right pterion approach, but he developed complete palsy of the third nerve postoperatively, which had an incomplete recovery in 12-month follow-up. We review the pertinent literature about pediatric oculomotor nerve schwannoma and discuss its clinical features and management.

Bilateral supratentorial epidural hematomas: a rare complication in adolescent spine surgery.

A 14-year-old girl presented with a rare case of spontaneous bilateral supratentorial epidural hematomas which developed rapidly following cervical surgery. The hematomas presumably resulted from dural dynamics changes secondary to cerebrospinal fluid loss and intracranial hypotension. Intracranial epidural hemorrhage after spinal surgery is extremely uncommon with only one previous case report. Spontaneous intracranial epidural hematoma is an extremely rare complication, but should be considered as a possible complication of spine surgery, especially in adolescents complicated by delayed consciousness and breathing restoration from anesthesia. This case report expands the presently known clinical spectrum of this uncommon complication.

Primary anaplastic solitary fibrous tumor of the tentorium cerebelli.

Meningeal solitary fibrous tumors (MSFT) have been described in about 80 patients as benign spindle-cell neoplasms, with few anaplastic variants. We report a 57-year-old male patient with a 4-month history of progressive headache caused by a primary anaplastic MSFT arising from the tentorium cerebelli. MRI revealed a tentorium-based tumor that extended into the occipital lobe superiorly and into the cerebellum inferiorly on the left. Following gross total resection of the tumor and postoperative radiotherapy, the patient experienced symptomatic improvement with no recurrence at the 12-month follow-up. The final tumor pathology was consistent with an anaplastic MSFT, with a Ki-67 proliferative index of 25%.

Unusual CT hyperattenuating dermoid cyst of cerebellum: a new case report and literature review.

Almost all intracranial dermoid cysts typically display low-density lesions on plain computerized tomography (CT) scans due to abundant lipids content. CT hyperattenuating dermoid cyst (CHADC) is very uncommon with only nine case reports in the literature update, which occurs exclusively in the posterior fossa. Moreover, CHADC with mural nodule is exceptionally rare, and only one such case was documented previously. Here, we report a new case of cerebellar CHADC with mural nodule in a 14-year-old male patient who presented with a 4-week history of dull headache and 5-day history of gait disturbance. With an average attenuation value of 89.9 Hounsfield units on CT scans, the lesion mainly displayed T1 hyperintensity, T2 hypointensity, and FLAIR hypointensity on magnetic resonance imaging. The patient underwent lesion gross total resection and symptomatic improvement, and final pathology was consistent with dermoid cyst. For further clarifying the mechanism of unusual CT hyperdensity, we sampled the cystic content and quantified its protein, calcium, and cholesterol, and our result suggested the high protein, high calcium, and low lipids in contents was the main mechanism of increased CT attenuation for CHADC.

A young and booming approach: the extreme lateral supracerebellar infratentorial approach.

Surgical accesses to lesions of the posterolateral pontomesencephalic junction (PMJ) region and the posterolateral tentorial gap remain a challenge in the field of neurosurgery. Since the first report of application of the extreme lateral supracerebellar infratentorial (ELSI) approach in resecting the PMJ lesions in 2000, a few articles concerning the ELSI approach have been published. The present review mainly provided an intimate introduction of the ELSI approach, and evaluated it in facets of patient position, skin incision, craniectomy, draining veins, retraction against the cerebellum, exposure limits, patient healing, as well as advantages and limitations compared with other approaches. The ELSI approach is proposed to be a very young and promising approach to access the lesions of posterolateral PMJ region and the posterolateral tentorial gap. Besides, it has several advantages such as having a shorter surgical pathway, causing less surgical complications, labor-saving, etc. Still, more studies are needed to improve this approach.

Primary pituitary fibrosarcoma presenting with multiple metastases: a case report and literature review.

Even though many cases of pituitary fibrosarcoma (PF) have been reported, the etiologic classification of these tumors, however, remains undefined. Moreover, owing to the paucity of available case studies, the clinical characteristics of primary pituitary fibrosarcoma (PPF) have not been fully described. We report a 26-year-old female with pathologically confirmed PPF, who presented with features of elevated intracranial pressure, oculomotor nerve palsy, field defects and panhypopituitarism. Despite the combination therapy, which included tumor removal, radiotherapy, and chemotherapy, magnetic resonance imaging demonstrated multiple intracranial and extracranial metastases at a seven-month follow-up, and the survival duration from diagnosis was only 11 months. Based on a review of the literature, we propose preliminary etiologic classification criteria for PF as well as a new therapeutic approach to reduce PPF recurrence and metastasis, including extended surgical resection and postoperative whole-brain radiotherapy.

Corpus callosum: a favorable target for rSFV-mediated gene transfer to rat brain with broad and efficient expression.

Recombinant Semliki Forest virus (rSFV), as a new kind of neurotropic vector system, has great potential of gene therapy for stroke. However, very little is known about its transduction characteristics in cerebral cortex or corpus callosum (CC) in vivo, which are common targets for gene transfer in experimental stroke therapy. Here, we investigate and compare rSFV-mediated gene expression at above two brain regions in rat; 2.0 x 10(7) IU of rSFV encoding green fluorescent protein (rSFV-GFP) was locally injected into CC or cerebral cortex in two groups. At 36 h following injection, the number of GFP-positive cells, GFP distribution volume, and GFP expression level were examined in the rat brain of each group using continuous frozen sections and enzyme-linked immunosorbent assay. rSFV vector displayed noticeably different transduction patterns in CC and cerebral cortex in vivo. CC injection of vector increased GFP-positive cell number by 802%, GFP transduction volume by 958%, and GFP expression level by 508% compared with cortical injection (all P < 0.01). We concluded that rSFV CC delivery significantly enhances transduction efficiency in rat brain with its ability to achieve transgene extensive transduction and abundant expression, and CC may be a favorable target for improving rSFV-based gene delivery efficiency to brain.

Nasal cavity-maxillary sinus-pterygopalatine fossa-Meckel's cave: a preliminary anatomic study of an endoscopy-based operative approach.

OBJECTIVE: To provide a new approach for the treatment of tumor in Meckel's cave, by dissecting adjacent structures of the nasal cavity-maxillary sinus-pterygopalatine fossa-Meckel's cave approach. METHODS: Fifteen adult cadaver heads (30 sides) were dissected and the correlated anatomic landmarks were observed, measured and analyzed in an operative route. RESULTS: The approach was divided into 3 steps: entering the maxillary sinus, the later pterygopalatine fossa and the final Meckel's cave. Safe access to Meckel's cave could be achieved by tracing the vidian neurovascular bundles and dissecting the quadrangular space (QS). The distances from the nasal columella to the apertura maxillaries, the sphenopalatine foramen, and the anterior foramen of the pterygoid canal were (44.08+/-2.61) mm, (64.83+/-2.42) mm, and (70.43+/-2.94) mm, respectively. The angles between the horizontal plate of the palatine bone and the link from nasal columella to apertura maxillaries, between the horizontal plate of the palatine bone and the link from nasal columella to sphenopalatine foramen were (38.10+/-2.46) degrees and (26.15+/-2.26) degrees , respectively. CONCLUSION: The endoscopic approach of transnasal maxillary sinus-pterygopalatine fossa-Meckel's cave (ENMPA) is a safe and direct way to access Meckel's cave, and could be employed for the treatment of tumor in Meckel's cave.

Recombinant adeno-associated virus serotype 1-vascular endothelial growth factor promotes neurogenesis and neuromigration in the subventricular zone and rescues neuronal function in ischemic rats.

OBJECTIVE: Vascular endothelial growth factor (VEGF) enhances neurogenesis in ischemic brains. However, in most circumstances, endogenous VEGF expression is limited and insufficient to prevent brain damage. We transferred the VEGF gene into brain tissue with recombinant adeno-associated virus serotype 1 (rAAV1) vectors and determined the effect of VEGF expression on neurogenesis and recovery of neurological function after brain ischemia. METHODS: Two groups (n = 32) of Sprague Dawley rats received intraventricular injection of AAV1-VEGF or AAV1-lacZ. Twenty-one days after gene transfer, rats underwent transient middle cerebral artery occlusion, and neurological severity score was measured 1, 2, 3, 7, 14, and 21 days later. Immunostaining was used to identify the quantity and distribution of VEGF expression. Double-immunofluorescence for doublecortin and bromodeoxyuridine or neuronal nuclei was performed to detect neurogenesis and the migration of neural progenitor cells. RESULTS: VEGF expression reduced the size of cerebral infarction and improved neurological function. It also enhanced the proliferation of neural progenitor cells in the subventricular zone and promoted their migration to the ischemic lesion. Neural precursors in the subgranular zone of the dentate gyrus were also increased; however, most of these cells did not move to the ischemic lesion and integrated with their region of origin. CONCLUSION: rAAV1-mediated expression of VEGF in the rat brain reduces the size of the infarcted lesion and promotes recovery of neurological function, likely by enhancing neurogenesis in the subventricular zone and promoting neural precursor migration to brain tissue around the core of the ischemic lesion.

[Recombinant AAV1 mediated vascular endothelial growth factor gene expression promotes angiogenesis and improves neural function: experiment with rats].

OBJECTIVE: To investigate the therapeutic effect of vascular endothelial growth factor (VEGF) gene expression mediated by recombinant AAV1 (rAAV1) vector in brain ischemia and the mechanism thereof. METHODS: Sixty-four SD rats were randomly divided into 2 equal groups and received intra-ventricular injection with rAAV1-VEGF or rAAV1-lacZ as controls. 21 days later the rats underwent transient middle cerebral artery occlusion (MCAO). Neurological severity score (NSS) was recorded 1, 2, 3, 7, 14, and 21 days after MCAO. 48 rats were sacrificed 21 days after MCAO and brains were taken out from 48 rats. Immune quantitative analysis was used to identify the quantity of VEGF expression. Immunohistochemistry was used to identify the site of VEGF expression. Immunofluorescence double labeling of von Willebrand factor (vWF) and 5-bromodeoxy-uridine (BrdU) was performed to detect the proliferation of endothelial cells. Fluorescein isothiocyanate (FITC)-dextran was infused into the caudal vein of 8 rats from each group and then the rats were killed with their brains taken out to evaluate the cerebral microvessel perfusion and microvessel density. RESULTS: The NSSs of the VEGF group 7, 14, and 21 days after MCAO were all significantly lower than those of the control group (all P < 0.05), and the VEGF165 protein expression quantity was 27 times as that of the control group (P < 0.05). Immunohistochemistry demonstrated that VEGF expression was distributed mainly in the caudate putamen, corpus callosum, choroid plexus, and hippocampus in the VEGF group, while no expression was detected in the control group. The microvessel density of the VEGF group was 157 +/- 13, significantly higher than that of the control group [(89 +/- 9), P < 0.05]. BrdU +/vWF + endothelial cells were detected in the area adjacent to the MCAO. The density of microvessel infused with FITC-dextran was (152,617 +/- 13,076) microm2/mm2 in the VEGF group, significantly higher than that of the control group [(91,658 +/- 6577) microm2/mm2 P < 0.05]. CONCLUSION: rAAV1 mediates the VEGF gene expression in multiple structures in the brain and attenuates the neurological deficit of MCAO. VEGF gene transfer may stimulate angiogenesis and improves blood supply in brain. Neovascularization may be a therapeutic strategy for brain ischemia.

Transplantation of neural stem cells modified by human neurotrophin-3 promotes functional recovery after transient focal cerebral ischemia in rats.

The study tested the hypothesis that transplantation of human neurotrophin-3 (hNT-3) over-expressing neural stem cells (NSCs) into rat striatum after a severe focal ischemia would promote functional recovery. Rat NSCs, transduced by Flag-tagged hNT-3 gene mediated by lentiviral vector (LV), were transplanted into the striatum ipsilateral to the injury of adult rats 7 days after 2-h occlusion of the middle cerebral artery (MCAO). From 3 days to 2 weeks after transplantation, the modified cells (NSCs-hNT3, as defined by Flag immunofluorencence staining) that survived the transplantation procedures could secrete significantly higher levels of neurotrophin-3 protein in the graft sites than controls (P<0.001). Furthermore, the rats that accepted NSCs-hNT3 exhibited enhanced functional recovery on neurological and behavioral tests, compared with controlled animals transplanted with saline or untransduced NSCs. This study suggests: (1) LV is an ideal vector to transduce foreign gene into the NSCs; (2) modified NSCs could carry therapeutic genes to disease tissues and express effectively; (3) modified cells could survive in the ischemic brains and continue to secrete neurotrophin-3 abundantly for over 2 weeks, which might have values for enhancing functional recovery after stroke.

rAAV vector-mediated gene therapy for experimental ischemic stroke.

The safest viral vector system for gene therapy is based on recombinant adeno-associated virus (rAAV) up to date in Phase I clinical trials, which has been developed rapidly and applied for ischemic stroke gene therapy in animal experiments since the past seven years. rAAV vector has made great progress in improving gene delivery by modification of the capsid and increasing transgene expression by encapsidation of double-stranded rAAV genome. And in all, nine therapeutic genes in 12 animal studies were successfully delivered using rAAV vector to ischemic brain via different approaches in rat or mice stroke models for gene therapy and the results suggested that rAAV could mediate genes' expression efficiently; most of them displayed evidently therapeutic efficacy with satisfactory biological safety. Gene therapy involving rAAV vector seems effective in attenuation of ischemic damage in stroke and has greatly promising potential use for patients in the future. In this review, we will focus on the basic biology and development of rAAV vector itself as well as the recent progress in the use of this vector for ischemic stroke gene therapy in animal experiments.

[Treatment of stroke in rats with bone marrow mesenchymal stem cells].

OBJECTIVE: To investigate the effects of treatment of stroke in rats with bone marrow mesenchymal stem cells (BMSCs) and mechanism thereof. METHODS: Bone marrow of a healthy volunteer was collected and the BMSCs were separated with density gradient centrifugation. The hBMSC were cultivated and harvested until the third passage. A number of adult male Sprague-Dawley rats received corresponding behavioral training before surgery and underwent transient middle cerebral arterial occlusion (MCAO) for 2 hours. Sixty of them showing the scores of 6 approximately 12 according to the modified neurological severity score system were randomly divided into 2 groups: treatment group (n = 48, injected into the cortex around the ischemic areas with hBMSCs 3x10(5)/15 microl) and control group (n = 12, injected with D-Hanks solution 15 microl 24 hours after the establishment of MCAO models. Morris water maze test, Rotarod test and adhesive-removal test were performed since the 4th day to the 32 day after transplantation once every 3 days. 1, 2, 3, and 4 weeks after the transplantation 12 rats from each group were killed randomly to take out their brains. Immunofluorescence was used to identify the migration, survival and differentiation of the hBMSC. RESULTS: A large number of hBMSC could be seen within 2 weeks after transplantation. The number of hBMSC decreased since the 21st day after transplantation and few cells could be found at the end of 1 month after. No definite evidence supported the differentiation of neural cells derived from the hBMSCs during the whole process. Morris water maze test showed that the mean escape time 1 week after transplantation of the treatment group was (69 +/- 10) s, significantly shorter than that of the control group [(120 +/- 0) s, P < 0.05] The significant difference persisted until the 4(th) week (P > 0.05). Rotarod test with the speed of 10 r/min showed that the mean latency period 10 days after transplantation of the treatment group was (167 +/- 18) s, significantly longer than that of the control group [(37 +/- 19) s, P < 0.05]. The significant difference persisted until the experimental terminal. The adhesive-removal test showed that the mean latency period 13 days after transplantation of the treatment group was (33 +/- 8) s, significant shorter than that of the control group [(84 +/- 13) s, P < 0.05]. The significant difference persisted until the experimental terminal. CONCLUSION: Injection of hBMSCs into brain cortex improves neurological functional recovery after stroke. The transplanted cells can migrate and survive for a certain period, but no hBMSC express proteins phenotype of neural cells.