Acute histopathological responses and long-term behavioral outcomes in mice with graded controlled cortical impact injury.

While animal models of controlled cortical impact often display short-term motor dysfunction after injury, histological examinations do not show severe cortical damage. Thus, this model requires further improvement. Mice were subjected to injury at three severities using a Pin-Point™-controlled cortical impact device to establish secondary brain injury mouse models. Twenty-four hours after injury, hematoxylin-eosin staining, Fluoro-Jade B histofluorescence, and immunohistochemistry were performed for brain slices. Compared to the uninjured side, we observed differences of histopathological findings, neuronal degeneration, and glial cell number in the CA2 and CA3 regions of the hippocampus on the injured side. The Morris water maze task and beam-walking test verified long-term (14-28 days) spatial learning/memory and motor balance. To conclude, the histopathological responses were positively correlated with the degree of damage, as were the long-term behavioral manifestations after controlled cortical impact. All animal procedures were approved by the Institutional Animal Care and Use Committee at Shanghai Jiao Tong University School of Medicine.

Endoscopic Fenestration of Twenty-Six Patients With Middle Fossa Arachnoid Cyst.

Middle fossa arachnoid cyst (MFAC) is the most common kind of arachnoid cyst. The objective of this study was to assess the efficacy of endoscopic fenestration for MFACs. The authors report 26 patients of MFAC with variety symptoms such as macrocrania, epilepsy, headache, and development delay. The authors performed surgery with a neuroendoscope to drain and fenestrate the cyst to obtain nearby cystocisternal communications under general anesthesia. All of the 26 patients had a successful fenestration, most of them had an improvement of at least 1 of their pretreatment symptoms with the substantial reduction of the cyst postoperatively. The authors conclude that endoscopic fenestration may be an acceptable and minimally invasive option for the management of symptomatic MFACs.

Glutamate carboxypeptidase II gene knockout attenuates oxidative stress and cortical apoptosis after traumatic brain injury.

BACKGROUND: Glutamate carboxypeptidase II (GCPII) inactivates the peptide co-transmitter N-acetylaspartylglutamate following synaptic release. Inhibition of GCPII elevates extracellular levels of the peptide, inhibits glutamate release and is neuroprotective in an animal model of traumatic brain injury. GCPII gene knockout mice were used to examine the cellular mechanisms underlying the neuroprotective efficacy of this transmitter system. RESULTS: Following controlled cortical impact injury, GCPII knockout (KO) mice exhibited reduced TUNEL-positive nuclei in the contusion margin of the cerebral cortex relative to wild type mice. Impact injury reduced glutathione levels and superoxide dismutase and glutathione peroxidase activities and increased malondialdehyde. Each of these effects was moderated in KO mice relative to wild type. Similarly, the injury-induced increases in cleaved caspase-3, cytosolic cytochrome c levels and Bcl-2/Bax ratio observed in wild type mice were attenuated in the knockout mice. CONCLUSIONS: These data support the hypothesis that the neuroprotective efficacy of GCPII KO in traumatic brain injury is mediated via a reduction in oxidative stress.

Improved neurite outgrowth on central nervous system myelin substrate by siRNA-mediated knockdown of Nogo receptor.

PURPOSE: To investigate the in vitro effect of short interfering RNAs (siRNAs) against Nogo receptor (NgR) on neurite outgrowth under an inhibitory substrate of central nervous system (CNS) myelin. METHODS: Three siRNA sequences against NgR were designed and transfected into cerebellar granule cells (CGCs) to screen for the most effcient sequence of NgR siRNA by using reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining. NgR siRNA sequence 1 was found the most efficient which was then transfected into the CGCs grown on CNS myelin substrate to observe its disinhibition for neurite outgrowth. RESULTS: Compared with the scrambled control sequence of siRNA, the NgR siRNA sequence 1 significantly decreased NgR mRNA level at 24 h and 48 h (p <0.05), which was recovered by 96 h after transfection. NgR immunoreactivity was also markedly reduced at 24 and 48 h after the transfection of siRNA sequence 1 compared with that before transfection (p<0.05). The NgR immunoreactivity was recovered after 72 h post-transfection. Moreover, the neurite outgrowth on the myelin substrate was greatly improved within 72 h after the transfection with siRNA sequence 1 compared with the scrambled sequence-transfected group or non-transfected group (p<0.05). CONCLUSION: siRNA-mediated knockdown of NgR expression contributes to neurite outgrowth in vitro.

Mice lacking glutamate carboxypeptidase II develop normally, but are less susceptible to traumatic brain injury.

Glutamate carboxypeptidase II (GCPII) is a transmembrane zinc metallopeptidase found mainly in the nervous system, prostate and small intestine. In the nervous system, glia-bound GCPII mediates the hydrolysis of the neurotransmitter N-acetylaspartylglutamate (NAAG) into glutamate and N-acetylaspartate. Inhibition of GCPII has been shown to attenuate excitotoxicity associated with enhanced glutamate transmission under pathological conditions. However, different strains of mice lacking the GCPII gene are reported to exhibit striking phenotypic differences. In this study, a GCPII gene knockout (KO) strategy involved removing exons 3-5 of GCPII. This generated a new GCPII KO mice line with no overt differences in standard neurological behavior compared to their wild-type (WT) littermates. However, GCPII KO mice were significantly less susceptible to moderate traumatic brain injury (TBI). GCPII gene KO significantly lessened neuronal degeneration and astrocyte damage in the CA2 and CA3 regions of the hippocampus 24 h after moderate TBI. In addition, GCPII gene KO reduced TBI-induced deficits in long-term spatial learning/memory tested in the Morris water maze and motor balance tested via beam walking. Knockout of the GCPII gene is not embryonic lethal and affords histopathological protection with improved long-term behavioral outcomes after TBI, a result that further validates GCPII as a target for drug development consistent with results from studies using GCPII peptidase inhibitors.

Endoscopic versus microscopic transsphenoidal pituitary adenoma surgery: a meta-analysis.

BACKGROUND: Endoscopic transsphenoidal surgery has gradually come to be regarded as a preferred option in the treatment of pituitary adenomas because of its advantages of improved visualization and its minimal invasiveness. The aim of this study was to compare and evaluate the outcomes and complications of endoscopic and microscopic transsphenoidal surgery in the treatment of pituitary adenomas. METHODS: We performed a systematic literature search of MEDLINE, EMBASE, the Cochrane Library and the Web of Science between January 1992 and May 2013. Studies with consecutive patients that explicitly and fully compared endoscopic and microscopic approaches in the treatment of pituitary adenomas were included. RESULTS: A total of 15 studies (n = 1,014 patients) met the inclusion criteria among 487 studies that involved endoscopic surgery and 527 studies that dealt with microscopic surgery. The rate of gross tumor removal was higher in the endoscopic group than in the microscopic group. The post-operative rates of septal perforation were less frequent in patients who underwent endoscopic surgery. There was no significant difference between the two techniques in the incidence rates of meningitis, diabetes insipidus, cerebrospinal fluid leak, epistaxis or hypopituitarism. The post-operative hospital stay was significantly shorter for the endoscopic surgery group compared with the microscopic surgery group (P < 0.05). There was no significant difference in the length of the operation (P > 0.05). CONCLUSIONS: The present study indicates that the endoscopic transsphenoidal approach is safer and more effective than microscopic surgery in the treatment of pituitary adenomas.

Blockade of N-acetylaspartylglutamate peptidases: a novel protective strategy for brain injuries and neurological disorders.

The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) is reported to suppress glutamate release mainly through selective activation of presynaptic Group II metabotropic glutamate receptor subtype 3 (mGluR3). Therefore, strategies of inhibition of NAAG peptidases and subsequent NAAG hydrolysis to elevate levels of NAAG could reduce glutamate release under pathological conditions and be neuroprotective by attenuating excitotoxic cell injury. A series of potent inhibitors of NAAG peptidases has been synthesized and demonstrated efficacy in experimental models of ischemic-hypoxic brain injury, traumatic brain injury, inflammatory pain, diabetic neuropathy, amyotrophic lateral sclerosis and phencyclidine-induced schizophrenia-like behaviors. The excessive glutamatergic transmission has been implicated in all of these neurological disorders. Thus, blockade of NAAG peptidases may augment an endogenous protective mechanism and afford neuroprotection in the brain. This review aims to summarize and provide insight into the current understanding of the novel neuroprotective strategy based on limiting glutamate excitotoxicity for a wide variety of brain injuries and neurological disorders.

Intramedullary conus medullaris metastasis from prostate carcinoma: A case report and review of the literature.

Intramedullary spinal cord metastases (ISCMs) are rare and account for 4-8.5% of central nervous system metastases. Only one case of biopsy-proven ISCM due to prostate cancer has previously been reported. The current study presents an additional unique case of a 74-year-old male who developed symptoms from an intramedullary conus medullaris metastasis as the first manifestation of prostate adenocarcinoma. To the best of our knowledge, this scenario is even more rare and has not previously been reported. The tumor was radically resected, followed by androgen blockade treatment. The patient's neurological deficit significantly improved, with no tumor recurrence during the follow-up period. In addition, the present study provides an overview of the previous literature concerning ISCMs from prostate cancer, and discusses the treatment options.

Intracranial choriocarcinoma occurrence in males: Two cases and a review of the literature.

Choriocarcinomas generally develop in females. Non-gestational choriocarcinoma in males is extremely rare. The present study describes two cases of young males who were diagnosed with intracranial choriocarcinoma. One case was of an aggressive choriocarcinoma with multiple metastases to the brain, but with an unidentified origin. The patient was admitted in the terminal stage of the cancer. Although a tumor resection was performed, the condition of the patient rapidly deteriorated and chemotherapy was not recommended. The patient succumbed nine days after the surgery. The second case was of a primary ventricular choriocarcinoma. The patient was hospitalized for acute hydrocephalus caused by a mass that was located in the ventricle. Following a tumor resection, the patient underwent a course of whole-brain and spinal radiotherapy. The patient was followed up for more than half a year and remained in a good condition. The present study describes the two cases and a comprehensive review of the literature that was performed to identify similar studies that document choriocarcinomas in males.