Primary olfactory mucosal cells promote axonal outgrowth in a three-dimensional assay.

Among the possible sources of autologous cells and tissues for use in spinal cord injury grafts, one promising source is the olfactory mucosa containing olfactory ensheathing cells and neural progenitor cells. Olfactory mucosa transplantation for spinal cord injury has been effective in animal models and in pilot clinical trials. However, the contributions of olfactory ensheathing cells and neurons in olfactory mucosa are unclear. For the present study, we prepared primary olfactory mucosal cells and used a cortex-Matrigel coculture assay system to examine the axonal outgrowth of olfactory mucosa. Axonal outgrowth from cortical slices was significantly enhanced in olfactory mucosal cells compared with noncell controls and respiratory mucosal cells, which have few olfactory ensheathing cells and neurons. Axonal outgrowth was severely reduced after treatment with an antineurotrophin cocktail. A conditioned medium in the olfactory mucosa-derived cell group contained neurotrophin-3. Some olfactory ensheathing cells and almost all neurons were immunopositive for neurotrophin-3. Axons originating from cortical slices targeted mainly the astrocyte-like olfactory ensheathing cells. Our findings demonstrate that the axonal outgrowth effect of olfactory mucosa is supported by both olfactory ensheathing cells and neurons in olfactory mucosa.

Neuroradiological, genetic and clinical characteristics of histone H3 K27-mutant diffuse midline gliomas in the Kansai Molecular Diagnosis Network for CNS Tumors (Kansai Network): multicenter retrospective cohort.

This study aims to elucidate the clinical and molecular characteristics, treatment outcomes and prognostic factors of patients with histone H3 K27-mutant diffuse midline glioma. We retrospectively analyzed 93 patients with diffuse midline glioma (47 thalamus, 24 brainstem, 12 spinal cord and 10 other midline locations) treated at 24 affiliated hospitals in the Kansai Molecular Diagnosis Network for CNS Tumors. Considering the term "midline" areas, which had been confused in previous reports, we classified four midline locations based on previous reports and anatomical findings. Clinical and molecular characteristics of the study cohort included: age 4-78 years, female sex (41%), lower-grade histology (56%), preoperative Karnofsky performance status (KPS) scores ≥ 80 (49%), resection (36%), adjuvant radiation plus chemotherapy (83%), temozolomide therapy (76%), bevacizumab therapy (42%), HIST1H3B p.K27M mutation (2%), TERT promoter mutation (3%), MGMT promoter methylation (9%), BRAF p.V600E mutation (1%), FGFR1 mutation (14%) and EGFR mutation (3%). Median progression-free and overall survival time was 9.9 ± 1.0 (7.9-11.9, 95% CI) and 16.6 ± 1.4 (13.9-19.3, 95% CI) months, respectively. Female sex, preoperative KPS score ≥ 80, adjuvant radiation + temozolomide and radiation ≥ 50 Gy were associated with favorable prognosis. Female sex and preoperative KPS score ≥ 80 were identified as independent good prognostic factors. This study demonstrated the current state of clinical practice for patients with diffuse midline glioma and molecular analyses of diffuse midline glioma in real-world settings. Further investigation in a larger population would contribute to better understanding of the pathology of diffuse midline glioma.

Coexisting filum terminale arteriovenous fistula and filum terminale lipoma treated with single-stage surgery: illustrative case.

BACKGROUND: Both filum terminale arteriovenous fistulas (FTAVFs) and filum terminale lipomas (FTLs) are rare. Because of this rarity, there is a paucity of data regarding concomitant FTAVF and FTL, and the optimal treatment remains to be defined. The authors describe a patient with coexisting FTAVF and FTL treated with single-stage surgery. OBSERVATIONS: A man in his 70s was referred to the authors' department because of a suspected spinal vascular malformation seen on magnetic resonance imaging that was performed to investigate lower limb weakness, intermittent claudication, and urinary incontinence. Previous imaging had shown a terminal lipoma with an internal flow void. Computed tomography angiography and digital subtraction angiography revealed an FTAVF, the feeder being a lateral sacral artery. The patient was treated surgically with curative intent. The FTL and tethered cord that had been identified by imaging were treated in the same procedure. Postoperative digital subtraction angiography showed absence of the abnormal vessels. The patient was discharged home on the 19th postoperative day. LESSONS: When considering treatment, it is important to determine whether symptoms are attributable mainly to FTL, tethered cord, or FTAVF. One-stage treatment is useful because it eliminates both the FTAVF and the factors that led to its development.

Design and rationale of low-dose erythropoietin in patients with ST-segment elevation myocardial infarction (EPO-AMI-II study): a randomized controlled clinical trial.

PURPOSE: The development of novel pharmaceutical interventions to improve the clinical outcomes of patients with acute ST-segment elevation myocardial infarction (STEMI) is an unmet medical need worldwide. In animal models, a single intravenous administration of erythropoietin (EPO) during reperfusion improves left ventricular (LV) function in the chronic stage. However, the results of recent proof-of-concept trials using high-dose EPO in patients with STEMI are inconsistent. In our pilot study, low-dose EPO after successful percutaneous coronary intervention (PCI) improved the LV ejection fraction (EF) and did not trigger severe adverse clinical events in patients with STEMI. One possible reason for this discrepancy is the dose of EPO used. METHODS AND RESULTS: We have started a double-blind, placebo-controlled, randomized, multicenter clinical trial (EPO-AMI-II) to clarify the safety and efficacy of low-dose EPO in patients with STEMI. STEMI patients who have a low LVEF (<50 %) will be randomly assigned to intravenous administration of placebo or EPO (6,000 or 12,000 IU) within 6 h after successful PCI. The primary endpoint is the difference in LVEF between the acute and chronic phases (6 months), as measured by single-photon emission computed tomography. The patient number needed for EPO-AMI-II is 600. The study will stop when superior efficacy or futility is detected by an interim analysis. This study has been approved by the Evaluation System of Investigational Medical Care. CONCLUSIONS: EPO-AMI-II study will clarify the safety and efficacy of low-dose EPO in STEMI patients with LV dysfunction in a double-blind, placebo-controlled, multicenter study. (247 words).

Case of Syringomyelia Associated with Ossified Yellow Ligament and Arachnoid Web.

Syringomyelia is often associated with Chiari malformation, trauma, infection, and spinal cord tumor. Although they are relatively rare diseases, arachnoid cysts and its related pathology, "arachnoid web" can sometimes lead to syrinx formation at the thoracic vertebral level. However, syrinx formation caused by degenerative spinal disorders, particularly at the thoracic vertebral levels, has rarely been reported. Herein, we present a case of syringomyelia with thoracic ossified yellow ligament (OYL) in a 79-year-old man, who underwent initial posterior decompression followed by arachnoid web removal. Posterior decompression via laminectomy of thoracic vertebra 2 and removal of the OYL improved the syrinx partially, but dorsal indentation of the spinal cord and a remnant syrinx were observed in post-operative magnetic resonance images, subsequent to the second surgery's successful removal of the arachnoid web, which had dorsally compressed the spinal cord. After the second operation, the syrinx shrunk further, and the patient could walk independently at 5 months after the operations. In our case, both the OYL and arachnoid web were responsible for syrinx formation. Therefore, the coincidence of degenerative vertebral diseases with a syrinx might indicate the coexistence of an underlying lesion. Furthermore, the arachnoid web in this case might have formed due to the denaturation of the arachnoid cyst triggered by the OYL.

Diffuse Idiopathic Skeletal Hyperostosis with Severely Displaced Spine Fracture Managed with Posterior Approach Alone: Case Reports and Literature Review.

Diffuse idiopathic skeletal hyperostosis (DISH) is a condition in which minor trauma can cause extremely unstable vertebral fractures. Spinal fractures associated with DISH are prone to instability due to the large moment of lever arm and secondary neurological deterioration; hence, surgical internal fixation is considered necessary. On the other hand, some reports suggest that patients with DISH have a high osteogenic potential. In this report, we describe three patients with DISH. These patients had spinal injuries that resulted in a large gap, for which anterior fixation with bone graft would generally be considered due to comminuted fractures. However, we achieved good bony fusion with posterior fixation alone, without forcible correction.

Lateral Lumbar Interbody Fusion Using Bone Graft Substitute for Lumbar Vertebral Fracture Associated Radiculopathy.

This study aims to present our surgical technique of lateral lumbar interbody fusion (LLIF) without corpectomy for lumbar vertebral fracture (LVF) associated radiculopathy. This study includes three patients treated with LLIF (mean age of 77.3 years, Group L) and three patients treated with PLIF (mean age of 75.7 years, Group P) to compare the surgical outcomes. The cartilage on the fractured vertebrae was aggressively resected with attention to avoid injury to the ring apophysis. The central cavity of the fractured endplate was filled with a bone graft substitute made of hydroxyapatite and collagen composite, followed by interbody fusion achieved by utilizing of a cage with sufficient length spanning the bilateral edges of the fractured vertebra. PLIF was performed with a standard technique using two interbody cages, and vertebroplasty was combined in one patient. Comparing to PLIF, LLIF could be performed with less estimated blood loss in shorter surgical time. Local kyphotic angle improved in all cases of Group L immediately after the surgery, but correction loss was observed at the final examination. The lordotic angle was lost in Group P postoperatively. Arthrodesis was achieved in all the cases. The mean VAS score for leg pain was 85.3 mm in Group L and 82.0 mm in Group P at preoperation and decreased to 8.7 mm and 11.3 mm, respectively, at postoperation. LLIF is an effective surgical option that enables stabilization of the fractured vertebra and reduces radicular pain by indirect neural decompression.

Bow hunter's stroke due to instability at the uncovertebral C3/4 joint.

Bow hunter's stroke is typically due to mechanical compression or stretching of the dominant vertebral artery (VA) during contralateral head rotation against the bony elements of the atlas and axis. We report a case of vertebrobasilar insufficiency due to bilateral vertebral artery occlusion at the left C3-4 and the right C1-2 junction on rightward head rotation. A 64-year-old man experienced ischemic symptoms during 90° head rotation to the right with complete resolution of symptoms after returning his head to the neutral position. Dynamic cervical angiography with rightward head rotation showed severe compression of the right VA at the transverse foramen of C3-4 and mechanical stenosis of the left VA at the C1-2 level. During head rotation, the flow of the right VA was decreased more than the left side. Cervical 3-D computed tomography (CT) on rightward head rotation demonstrated displacement of the uncovertebral C3-4 joint, with excessive rotation of the C3 vertebral body. Based on these findings, instability at C3-4 was suspected to be the main cause of the vertebrobasilar insufficiency. Anterior discectomy and fusion at the C3/4 level were performed. Postoperatively, the patient experienced complete resolution of symptoms, and dynamic cervical angiography showed disappearance of the compression of the right VA. To our knowledge, this is the first reported case of bow hunter's stroke diagnosed by dynamic cerebral angiography and cervical 3-D CT without angiography, and treated by anterior decompression and fusion without decompression of the VA.

Vertebral Endplate Cyst Formation in Relation to Properties of Interbody Cages.

OBJECTIVE: This retrospective study aimed to compare vertebral endplate cyst formation (VECF), an early predictor for pseudoarthrosis, in different types of interbody cages. METHODS: We reviewed 84 cases treated with single-level posterior/transforaminal lumbar interbody fusion. We utilized a polyetheretherketone cage in 20 cases (group P), a titanium cage in 16 cases (group Ti), a titanium-coating polyetheretherketone cage in 13 cases (group TiP) and a porous tantalum cage in 35 cases (group Tn). VECF was evaluated comparing the computed tomography scans taken at day 0 and 6-month postoperation. We defined VECF (+) as enlargement of a pre-existing cyst or de novo formation of a cyst with the diameter over 2 mm. We calculated the adjusted odds ratio (OR) and 95% confidence intervals (CIs) as an indicator of association between different types of cages and VECF using a logistic regression model. RESULTS: VECF was observed in 13 (65%), 7 (44%), 9 (69%), and 8 (23%) cases in groups P, Ti, TiP and Tn, respectively. VECF correlated with the type of cage (p = 0.04). In comparison with group P, the proportion of VECF (+) cases was lower in group Tn (OR, 0.16; 95% CI, 0.04-0.60) but not different in group Ti (OR, 0.47; 95% CI, 0.10-2.20) and group TiP (OR, 1.06; 95% CI, 0.21-5.28). No patient underwent additional surgery for the fused spinal level during the follow-up periods (average, 37.9 months; range, 6-76 months). CONCLUSION: VECF was the least in the porous Tn cage, suggesting its potential superiority for initial stability.

Early Development of Syringomyelia after Spinal Cord Injury: Case Report and Review of the Literature.

We report a case of post-traumatic syringomyelia (PTS), which developed 2 months after spinal cord injury (SCI). A 20-year-old man who was involved in a motorcycle accident sustained a complete SCI resulting from a burst fracture of the T5 vertebral body. He underwent posterior fixation with decompression at another hospital 2 days after the injury. Postoperative imaging suggested that spinal stenosis endured at the T4 level and swelling of the spinal cord above that level. Two months later, he felt dysesthetic pain in his forearms and hands, but the cause of the pain was not examined in detail. Four months after the injury, he presented with motor weakness in the upper extremities. Magnetic resonance imaging (MRI) showed syringomyelia ascending from the T3 level to the C1 level, and he was referred to our hospital immediately. The imaging studies suggested that PTS was caused by congestion of the cerebrospinal fluid (CSF) at the T3 level. The patient was treated with syringosubarachnoid (SS) shunt at the T1-T2 level, whereby neurological symptoms of the upper extremities were immediately relieved. Postoperative MRI showed shrinkage of the syrinx. At the latest follow-up 2 years postoperatively, there was no sign of recurrence. It is noteworthy that PTS potentially occurs in the early phase after severe SCI. We discuss relevant pathology and surgical treatment through a review of previous literature.

Cervical osteogenic degeneration in Japanese professional wrestlers and its relationship to cervical spine injury.

OBJECTIVEThis study aimed to investigate the characteristics of cervical degeneration in Japanese professional wrestlers and its relationship with the risk of cervical spine injury (CSI).METHODSSince 2012, 27 Japanese male wrestlers belonging to a professional wrestling association have undergone periodical medical examinations of the cervical spine. If neurological symptoms were observed in the wrestlers, the resident trainers urged them to undergo a brief examination at the authors' institutions. In addition to this prospective research study, the mechanisms of the CSIs that occurred in 5 wrestlers, including 2 with CSI before 2012 and 3 who were independent from the professional wrestling association, were retrospectively investigated by reviewing the circumstances of the injury and the wrestlers' imaging studies.RESULTSThe mean age of the wrestlers was 36.9 years (range 23-56 years) at the initial examination. An anterior giant ossifying lesion (AGOL) was observed in the anterior aspect of the cervical spine of 11 wrestlers (41%). The AGOLs tended to grow and spread to multiple spinal levels as the wrestlers aged. Of the 12 wrestlers with osteogenic lesions, 10 older than 40 years of age (83%) had an AGOL, which is frequently accompanied by osseous spinal canal stenosis. Two wrestlers presented with spinal cord compression with intramedullary intensity change on MRI. However, during the follow-up period, no spinal cord injury (SCI) occurred in the wrestlers, although thoracolumbar injury occurred in 2 wrestlers during a match. In examining the 5 wrestlers with CSI, the injury occurred at the spinal levels without an AGOL. The most frequent pathology of CSI (60%) was SCI at the spinal level adjacent to the multilevel AGOL.CONCLUSIONSAGOL is a peculiar cervical degeneration of Japanese professional wrestlers, especially in aged wrestlers. The AGOL appears to be a biological reaction to reinforce the anterior aspect of the cervical spine of professional wrestlers, who routinely defend themselves in a flexed neck posture against their opponent. The present results suggest that the risk of CSI is not increased by spinal canal stenosis accompanied by AGOL. Further studies are needed to investigate the relationship between the wrestlers' cervical degeneration and the risk of CSI in more detail.

Adult Case of Atlantoaxial Rotatory Fixation Treated with In Situ Fixation Using an Unusual Posterior Instrumentation Construct.

Atlantoaxial rotatory fixation (AARF) occurs commonly in children who have undergone trauma. It is usually corrected with conservative therapy. In this report, however, the patient was an adult with AARF who was treated surgically. A 64-year-old woman presented with a 1-year history of spastic gait and hand clumsiness. Imaging studies revealed the presence of AARF, os odontoideum, and severe spinal cord compression at that spinal level. As the AARF had not been responded to head traction with a halo device, we decided to treat the patient with in situ posterior fixation. Because the rigid dislocation was present between the atlas and the axis, we were forced to make an unusual instrumentation construct. Neurological symptoms other than hand numbness diminished after the surgery, and arthrodesis was obtained between the occiput and the axis. It should be noted that surgical planning for posterior instrumentation construct is required when rigid AARF is treated surgically.

Report of a familial case of proatlas segmentation abnormality with late clinical onset.

Although proatlas segmentation abnormalities as developmental remnants around the foramen magnum have been reported in postmortem studies, they are rarely documented in a clinical setting. This report details the clinical and radiological characteristics of a rare case of proatlas segmentation abnormalities with clinical onset during the seventh decade of life. This case was suspected to have a familial factor. We also review the literature regarding this condition.

Peri-infarct depolarizations reveal penumbra-like conditions in striatum.

Spreading depression-like peri-infarct depolarizations not only characterize but also worsen penumbra conditions in cortical border zones of experimental focal ischemia. We intended to investigate the relevance of ischemic depolarization in subcortical regions of ischemic territories. Calomel electrodes measured DC potentials simultaneously in the lateral and medial portions of the caudate nucleus (CN) of 11 anesthetized cats after permanent occlusion of the middle cerebral artery. Additionally, platinum electrodes measured cerebral blood flow (CBF) in the CN, and laser Doppler probes CBF in the cortex. Depolarizations (negative DC shifts >10 mV) were obtained in 10 of 11 cats. Further differentiation revealed that short-lasting spreading depression-like depolarizations (SDs; 5 of 10 cats: 5.24 +/- 1.22 min total duration; 23.3 +/- 4.2 mV amplitude) were predominantly found in medial and longer depolarizations (LDs; 4 of 10 cats: 64.7 +/- 47.5 min; 25.0 +/- 11.3 mV) in the lateral CN. Terminal depolarizations (TDs; 6 of 10 cats; without repolarization) occurred immediately after occlusion or at later stages, being then accompanied by elevations of intracranial pressure presumably inducing secondary CBF reduction. CBF tended to be lower in regions with TDs (33.3 +/- 29.9% of control) and LDs (37.3 +/- 22.8%) than in regions with SDs (51.5 +/- 48.0%). We conclude that in focal ischemia, transient peri-infarct depolarizations emerge not only in cortical but also in striatal gray matter, thereby demonstrating the existence of subcortical zones of ischemic penumbra. The generation of these ischemic depolarizations is a multifocal process possibly linked to brain swelling and intracranial pressure rise in the later course of focal ischemia, and therefore a relevant correlate of progressively worsening conditions.

Isolation of human adult olfactory sphere cells as a cell source of neural progenitors.

Olfactory stem cells are generated from olfactory mucosa. Various culture conditions generate olfactory stem cells that differ according to species and developmental stage and have different progenitor or stem cell characteristics. Olfactory spheres (OSs) are clusters of progenitor or stem cells generated from olfactory mucosa in suspension culture. In this study, adult human OSs were generated and their characteristics analyzed. Human OSs were adequately produced from olfactory mucosa with area over 40 mm(2). Immunocytochemistry (ICC) and fluorescence-activated cell sorting showed that human OSs were AN2 and A2B5-positive. Immunofluorescence analysis of cell type-specific ICC indicated that the number of Tuj1-positive OS cells was significantly elevated. Tuj1-positive cells displayed typical neuronal soma and dendritic morphology. Human OS cells were also immunopositive for MAP2. By contrast, few RIP-, O4-, and GFAP-positive cells were present. These RIP, O4, and GFAP-positive cells did not resemble bona fide oligodendrocytes and astrocytes morphologically. In culture to induce differentiation of oligodendrocytes, human OS cells also expressed neuronal markers, but neither oligodendrocyte or astrocyte markers. These findings suggest that human OS cells autonomously differentiate into neurons in our culture condition and have potential to be used as a cell source of neural progenitors for their own regenerative grafts, avoiding the need for immunosuppression and ethical controversies.

Presence of trans-synaptic neurons derived from olfactory mucosa transplanted after spinal cord injury.

STUDY DESIGN: Using biotinylated dextran amine (BDA) and wheat germ agglutinin (WGA) tracers, we measured the effectiveness of olfactory mucosa (OM) transplantation as a scaffold in a rat model of chronic spinal cord injury (SCI). OBJECTIVE: We examined whether OM transplantation for chronic SCI in rats results in reconstruction of neuronal pathways by both regeneration of the remaining axons and supply of OM-derived trans-synaptic neurons. SUMMARY OF BACKGROUND DATA: OM is one of the ideal scaffolds for axonal regeneration after chronic SCI. METHODS: Rats received a mild contusion at vertebral level T6-T7. Two weeks after SCI, enhanced green fluorescent protein rat-derived OM, respiratory mucosa, and phosphate-buffered saline were transplanted into each group of SCI rats. Ten weeks after SCI, BDA was injected into the right sensorimotor cortex. Eleven weeks after SCI, WGA was injected into the L1-L2 posterior column to label the corticospinal tract retrogradely and trans-synaptically. Twelve weeks after SCI, rats were killed and their spinal cords were divided into cervical (area a), thoracic-injured (area b), and lower thoracic portions (area c). Immunohistochemically, sections of area (b) were evaluated by counting cells positive for enhanced green fluorescent protein, 4',6-diamidino-2-phenylindole, WGA, and BDA (OM and respiratory mucosa groups). Axonal regenerations were estimated by counting WGA- and BDA-positive dots in transverse sections of area (a) and area (c). RESULTS: Compared with respiratory mucosa and phosphate-buffered saline transplantation, OM transplantation increased the number of WGA-positive dots in area (a), and the number of BDA-positive dots in area (c) was more after OM transplantation than after phosphate-buffered saline transplantation. Furthermore, the number of quadruple-positive cells in area (b) was much higher after OM transplantation. CONCLUSION: Our results provide both indirect and direct evidence for the presence of trans-synaptic neurons. OM transplantation in rats with chronic SCI resulted in reconstruction of neural pathways by both providing trans-synaptic neurons and supporting regeneration of remaining axons. The olfactory mucosa is thought to be an efficacious scaffold to produce the relay neuron in chronic spinal cord injury.

Intradural extramedullary spinal ependymoma: a case report of malignant transformation occurring.

Intradural extramedullary spinal ependymomas are extremely rare. Herein, we describe a lesion-type spinal ependymoma that followed a malignant course, and discuss its clinical presentation, etiopathogenesis, and treatment. We present a patient who was diagnosed with an intradural extramedullary spinal tumor at T4-T6. The patient underwent gross total resection of the tumor without damage to the spinal cord. Histological examination, classified the lesion as a World Health Organization (WHO)-grade 2 ependymoma. One and a half years later, magnetic resonance imaging detected a recurring tumor at T4-T5. The tumor was removed and classified as a WHO-grade 3 anaplastic ependymoma. The patient was started on a course of regional spinal cord radiotherapy. The patient achieved tumoral control and clinical stabilization after the recurrence. We must consider the differential diagnosis of intradural extramedullary spinal tumors. The best treatment for this lesion is gross total resection and adjunctive radiotherapy is necessary in cases of malignant-change.

Training to acquire psychomotor skills for endoscopic endonasal surgery using a personal webcam trainer.

OBJECT: Existing training methods for neuroendoscopic surgery have mainly emphasized the acquisition of anatomical knowledge and procedures for operating an endoscope and instruments. For laparoscopic surgery, various training systems have been developed to teach handling of an endoscope as well as the manipulation of instruments for speedy and precise endoscopic performance using both hands. In endoscopic endonasal surgery (EES), especially using a binostril approach to the skull base and intradural lesions, the learning of more meticulous manipulation of instruments is mandatory, and it may be necessary to develop another type of training method for acquiring psychomotor skills for EES. Authors of the present study developed an inexpensive, portable personal trainer using a webcam and objectively evaluated its utility. METHODS: Twenty-five neurosurgeons volunteered for this study and were divided into 2 groups, a novice group (19 neurosurgeons) and an experienced group (6 neurosurgeons). Before and after the exercises of set tasks with a webcam box trainer, the basic endoscopic skills of each participant were objectively assessed using the virtual reality simulator (LapSim) while executing 2 virtual tasks: grasping and instrument navigation. Scores for the following 11 performance variables were recorded: instrument time, instrument misses, instrument path length, and instrument angular path (all of which were measured in both hands), as well as tissue damage, max damage, and finally overall score. Instrument time was indicated as movement speed; instrument path length and instrument angular path as movement efficiency; and instrument misses, tissue damage, and max damage as movement precision. RESULTS: In the novice group, movement speed and efficiency were significantly improved after the training. In the experienced group, significant improvement was not shown in the majority of virtual tasks. Before the training, significantly greater movement speed and efficiency were demonstrated in the experienced group, but no difference in movement precision was shown between the 2 groups. After the training, no significant differences were shown between the 2 groups in the majority of the virtual tasks. Analysis revealed that the webcam trainer improved the basic skills of the novices, increasing movement speed and efficiency without sacrificing movement precision. CONCLUSIONS: Novices using this unique webcam trainer showed improvement in psychomotor skills for EES. The authors believe that training in terms of basic endoscopic skills is meaningful and that the webcam training system can play a role in daily off-the-job training for EES.

Adult olfactory sphere cells are a source of oligodendrocyte and Schwann cell progenitors.

The olfactory epithelial layer contains multipotent horizontal basal cells (HBCs) that differentiate into olfactory sensory neurons. Here, we show that rat HBCs express oligodendrocyte progenitor cell (OPC) and astrocyte markers. We generated olfactory sphere (OS) cells in cultures that were derived from adult rat olfactory mucosa. Fluorescence-activated cell sorting and immunofluorescence analyses showed that OS cells also express OPC and astrocyte markers. Interestingly, OS cells underwent oligodendrocyte differentiation in vitro. To study oligodendrocyte differentiation in vivo, OS cells were transplanted into injured rat spinal cords. The transplanted cells integrated into host tissue and differentiated into oligodendrocytes. When transected saphenous nerve ends were encased in collagen-containing silicone tubes with or without OS cells, the transplanted OS cells differentiated into Schwann cells. Our data provide new insights into of the stemness of OS cells.

Histopathological study of spinal meningioma originating from the arachnoid villi.

Although the histogenesis of meningiomas remains unclear, it is believed that arachnoid cells are the most likely origin of this type of neoplasm. Further, little attention has been paid to the histopathology of spinal meningiomas arising from the arachnoid villi. We came across a case of spinal meningioma that was locally attached to the arachnoid membrane. The associated arachnoid villi were investigated by light microscopy and immunohistochemical analysis. We confirmed the presence of tumor cells under the fibrous capsule that forms the outer component of the arachnoid villi. Tumor cells grew out from the apical portion of the arachnoid villi. Furthermore, immunohistochemical study suggested that arachnoid cells made the transition to tumor cells on the arachnoid cell layer.