Loss of hnRNPA1 in ALS spinal cord motor neurons with TDP-43-positive inclusions

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by loss of motor neurons and appearance of skein-like inclusions. The inclusions are composed of trans-activation response (TAR) DNA-binding protein 43 (TDP-43), a member of the heterogeneous nuclear ribonucleoprotein (hnRNP) family. hnRNPA1 and hnRNPA2/B1 are hnRNPs that interact with the C-terminus of TDP-43. Using immunohistochemistry, we investigated the association between TDP-43 and hnRNPA1 in ALS spinal motor neurons. We examined spinal cords of seven ALS cases and six muscular dystrophy cases (used as controls) for the presence of TDP-43 and hnRNPA1 protein. In the control cases, hnRNPA1 immunoreactivity in motor neurons was intense in the nucleus and weak in the cytoplasm where it showed a fine granular appearance. In the ALS cases, hnRNPA1 immunoreactivity in motor neurons was reduced in the nuclei of neurons with skein-like inclusions but was not detected in the skein-like inclusions. The marked loss of hnRNPA1 in motor neurons with concomitant cytoplasmic aggregation of TDP-43 may represent a severe disturbance of mRNA processing, suggesting a key role in progressive neuronal death in ALS.

Elevated expression of fatty acid synthase and nuclear localization of carnitine palmitoyltransferase 1C are common among human gliomas

Fatty acid synthase (FASN) and carnitine palmitoyltransferase 1C (CPT1C), a brain-specific isoform of the CPT1 family, are upregulated in certain types of cancers, including gliomas. Acetyl-CoA carboxylase (ACC) catalyzes the carboxylation of acetyl-CoA to malonyl-CoA, the rate-limiting step in fatty acid synthesis, and its phosphorylated form inhibits lipid synthesis. We examined the expression and subcellular localization of these fatty acid metabolism-related molecules in human gliomas. We performed immunostaining of two glioma cell lines (U373MG and U87MG) and 41 surgical specimens of diffuse gliomas with various histological grades (21 with the isocitrate dehydrogenase 1(IDH1) R132H mutation and 20 without the mutation). In the cultured glioma cells, CPT1C and phosphorylated ACC (p-ACC) were mainly localized to the nuclei, whereas FASN localized to the cytoplasm. In the surgical specimens, most glioma tissues showed nuclear staining for CPT1C and p-ACC, and cytoplasmic staining for FASN, regardless of the genetic status of IDH1 and the histological grade. Therefore, elevated cytoplasmic expression of FASN and nuclear localization of CPT1C are common among human diffuse gliomas, which may be regulated by the differential phosphorylation status of ACC in the cellular compartment.

Multiphasic acute disseminated encephalomyelitis associated with atypical rubella virus infection

We report the first case of an occurrence of multiphasic acute disseminated encephalomyelitis (ADEM) associated with atypical rubella virus infection with no rash and long-term increased titers of serum anti-rubella IgM in a 17-year-old male who had no history of rubella vaccination. He suffered from at least six clinical exacerbations with disseminated hyperintense lesions on FLAIR MR images during the course of 18 months. Repeated methylprednisolone pulse therapy and intravenous immunoglobulin therapy resolved the exacerbations. In patients with multiphasic ADEM of unknown etiology, clinicians should also consider the possibility of preceding infection with rubella virus.

Extensive dysregulations of oligodendrocytic and astrocytic connexins are associated with disease progression in an amyotrophic lateral sclerosis mouse model

Background

Non-cell-autonomous motor neuronal death is suggested in a mutant Cu/Zn superoxide dismutase 1 (mSOD1)-mediated amyotrophic lateral sclerosis (ALS) model, in which glial cells play significant roles in disease progression. Connexins (Cxs) form homotypic or heterotypic gap junctions (GJs) and allow direct intercellular communications among nervous tissue cells. The role of Cxs in motor neuron disease has never been investigated; therefore, we aimed to evaluate alterations of Cxs in mSOD1-transgenic (mSOD1-Tg) mice in comparison with their non-transgenic (non-Tg) littermates at the same ages.

Methods

We pathologically evaluated temporal changes to astrocytic Cx43/Cx30 and oligodendrocytic Cx47/Cx32 immunoreactivities at presymptomatic, disease-progressive, and end stages, relative to aquaporin-4 (AQP4), glial fibrillary acidic protein (GFAP), excitatory amino acid transporter-2 (EAAT2), myelin-oligodendrocyte glycoprotein (MOG), and Nogo-A immunoreactivities, and observed neuronal loss by NeuN and neurofilament immunostaining, and microglial response by Iba-1 immunostaining. We also performed quantitative immunoblotting and real-time PCR analyses for Cxs.

Results

The mSOD1-Tg mice showed neuronal and axonal loss in the anterior horns of the lumbar spinal cord accompanied by increased activation of microglia compared with non-Tg mice at the disease-progressive and end stages. Expression patterns of Cxs were not different between mSOD1-Tg and non-Tg mice at the presymptomatic stage, but immunoreactivities for GFAP, Cx43, Cx30 and AQP4 were increased in the anterior horns of mSOD1-Tg mice at the disease-progressive and end stages. By contrast, Cx47 and Cx32 immunoreactivities were markedly diminished in Nogo-A-positive oligodendrocytes in the anterior horns of mSOD1-Tg mice at the disease-progressive and end stages, especially in oligodendrocytes showing SOD1 accumulation. EAAT2 immunoreactivity was also diminished in the anterior horns of mSOD1-Tg mice at the disease-progressive and end stages. Quantitative immunoblotting revealed a significant reduction in Cx47 and Cx32 protein levels in mSOD1-Tg mice at the disease-progressive and end stages. The levels of Cx47 and Cx32 mRNAs were also decreased at these stages.

Conclusions

Our findings indicate that oligodendrocytic and astrocytic GJ proteins in the anterior horns of spinal cord in mSOD1-Tg mice are profoundly affected at the disease-progressive and end stages, where disruption of GJs among glial cells may exacerbate motor neuronal death.

Amide proton transfer imaging of adult diffuse gliomas: correlation with histopathological grades

BACKGROUND

Amide proton transfer (APT) imaging is a novel molecular MRI technique to detect endogenous mobile proteins and peptides through chemical exchange saturation transfer. We prospectively assessed the usefulness of APT imaging in predicting the histological grade of adult diffuse gliomas.

METHODS

Thirty-six consecutive patients with histopathologically proven diffuse glioma (48.1 ± 14.7 y old, 16 males and 20 females) were included in the study. APT MRI was conducted on a 3T clinical scanner and was obtained with 2 s saturation at 25 saturation frequency offsets ω = -6 to +6 ppm (step 0.5 ppm). δB0 maps were acquired separately for a point-by-point δB0 correction. APT signal intensity (SI) was defined as magnetization transfer asymmetry at 3.5 ppm: magnetization transfer ratio (MTR)asym = (S[-3.5 ppm] - S[+3.5 ppm])/S0. Regions of interest were carefully placed by 2 neuroradiologists in solid parts within brain tumors. The APT SI was compared with World Health Organization grade, Ki-67 labeling index (LI), and cell density.

RESULTS

The mean APT SI values were 2.1 ± 0.4% in grade II gliomas (n = 8), 3.2 ± 0.9% in grade III gliomas (n = 10), and 4.1 ± 1.0% in grade IV gliomas (n = 18). Significant differences in APT intensity were observed between grades II and III (P < .05) and grades III and IV (P < .05), as well as between grades II and IV (P < .001). There were positive correlations between APT SI and Ki-67 LI (P = .01, R = 0.43) and between APT SI and cell density (P < .05, R = 0.38). The gliomas with microscopic necrosis showed higher APT SI than those without necrosis (P < .001).

CONCLUSIONS

APT imaging can predict the histopathological grades of adult diffuse gliomas.

Usefulness of three-dimensional T1-weighted spoiled gradient-recalled echo and three-dimensional heavily T2-weighted images in preoperative evaluation of spinal dysraphism

PURPOSE

The aim of this study was to evaluate the usefulness of three-dimensional T1-weighted spoiled gradient-recalled echo (3D T1-GRE) images for the preoperative anatomical evaluation of lumbosacral lipoma, thick filum terminale, and myelomeningocele as a means of compensating for the drawbacks of 3D heavily T2-weighted (3D hT2-W) images.

METHODS

Nine patients with lumbosacral lipomas, one patient with tight filum terminale, and five patients with myelomeningoceles were included in this study. 3D T1-GRE images were compared with 3D hT2-W images or conventional magnetic resonance images in terms of delineation of lipomas and other structures in the patients with lipomas and tight filum terminale. For patients with myelomeningoceles, 3D T1-GRE images were compared with 3D hT2-W images in terms of artifacts in the cerebrospinal fluid (CSF) space.

RESULTS

The 3D T1-GRE images demonstrated lipomas with good contrast to the spinal cord and CSF space and more clearly delineated the anatomical relationship between lipomas and these structures than did the 3D hT2-W images. The 3D T1-GRE images delineated dural defects through which extradural lipomas penetrated into the intradural space. The 3D T1-GRE images also demonstrated the presence or absence of lipomas in the filum terminale and the absence of artifact in the myelomeningoceles. Furthermore, they were useful for differentiating artifacts observed on the 3D hT2-W images from nerve elements.

CONCLUSIONS

The complementary use of 3D T1-GRE and 3D hT2-W images may compensate for the drawbacks of 3D hT2-W images and may eventually improve lesion visualization and surgical decision making.

Connexin 43 astrocytopathy linked to rapidly progressive multiple sclerosis and neuromyelitis optica

BACKGROUND

Multiple sclerosis (MS) and neuromyelitis optica (NMO) occasionally have an extremely aggressive and debilitating disease course; however, its molecular basis is unknown. This study aimed to determine a relationship between connexin (Cx) pathology and disease aggressiveness in Asian patients with MS and NMO.

METHODS/PRINCIPAL FINDINGS

Samples included 11 autopsied cases with NMO and NMO spectrum disorder (NMOSD), six with MS, and 20 with other neurological diseases (OND). Methods of analysis included immunohistochemical expression of astrocytic Cx43/Cx30, oligodendrocytic Cx47/Cx32 relative to AQP4 and other astrocytic and oligodendrocytic proteins, extent of demyelination, the vasculocentric deposition of complement and immunoglobulin, and lesion staging by CD68 staining for macrophages. Lesions were classified as actively demyelinating (n=59), chronic active (n=58) and chronic inactive (n=23). Sera from 120 subjects including 30 MS, 30 NMO, 40 OND and 20 healthy controls were examined for anti-Cx43 antibody by cell-based assay. Six NMO/NMOSD and three MS cases showed preferential loss of astrocytic Cx43 beyond the demyelinated areas in actively demyelinating and chronic active lesions, where heterotypic Cx43/Cx47 astrocyte oligodendrocyte gap junctions were extensively lost. Cx43 loss was significantly associated with a rapidly progressive disease course as six of nine cases with Cx43 loss, but none of eight cases without Cx43 loss regardless of disease phenotype, died within two years after disease onset (66.7% vs. 0%, P=0.0090). Overall, five of nine cases with Cx43 loss and none of eight cases without Cx43 loss had distal oligodendrogliopathy characterized by selective myelin associated glycoprotein loss (55.6% vs. 0.0%, P=0.0296). Loss of oligodendrocytic Cx32 and Cx47 expression was observed in most active and chronic lesions from all MS and NMO/NMOSD cases. Cx43-specific antibodies were absent in NMO/NMOSD and MS patients.

CONCLUSIONS

These findings suggest that autoantibody-independent astrocytic Cx43 loss may relate to disease aggressiveness and distal oligodendrogliopathy in both MS and NMO.

Pediatric glioblastoma with oligodendroglioma component: aggressive clinical phenotype with distinct molecular characteristics

The 2007 World Health Organization classification defined a new variant of glioblastoma (GBM) containing oligodendroglioma foci as GBM with an oligodendroglioma component (GBMO), which shows a favorable clinical outcome compared with "classic" GBM. However, all of the reported cases of GBMO have been adult cases, with no previous reports of pediatric cases. In this report, we demonstrated molecular characteristics of a pediatric GBMO case, showing aggressive clinical behavior with 8-month overall survival. The case showed neither isocitrate dehydrogenase 1/2 genes (IDH1/2) mutation nor 1p/19q co-deletion, a hallmark of oligodendroglioal tumors. In addition, microsatellite instability, leading to the putative mechanism of temozolomide (TMZ) resistance, was frequently detected. Molecular genetic analysis may provide critical prognostic and therapeutic insights, especially for the pediatric glioma containing oligodendroglioma components.

Radiation-induced spinal cord glioblastoma with cerebrospinal fluid dissemination subsequent to treatment of lymphoblastic lymphoma

Background:

Radiation-induced glioma arising in the spinal cord is extremely rare. We report a case of radiation-induced spinal cord glioblastoma with cerebrospinal fluid (CSF) dissemination 10 years after radiotherapy for T-cell lymphoblastic lymphoma.

Case Description:

A 32-year-old male with a history of T-cell lymphoblastic lymphoma presented with progressive gait disturbance and sensory disturbance below the T4 dermatome 10 years after mediastinal irradiation. Gadolinium-enhanced magnetic resonance (MR) imaging revealed an intramedullary tumor extending from the C6 to the T6 level, corresponding to the previous radiation site, and periventricular enhanced lesions. In this case, the spinal lesion was not directly diagnosed because the patient refused any kind of spinal surgery to avoid worsening of neurological deficits. However, based on a biopsy of an intracranial disseminated lesion and repeated immmunocytochemical examination of CSF cytology, we diagnosed the spinal tumor as a radiation-induced glioblastoma. The patient was treated with radiotherapy plus concomitant and adjuvant temozolomide. Then, the spinal tumor was markedly reduced in size, and the dissemination disappeared.

Conclusion:

We describe our detailed diagnostic process and emphasize the diagnostic importance of immunocytochemical analysis of CSF cytology.

An autopsy case of the Marburg variant of multiple sclerosis (acute multiple sclerosis)

We herein report an autopsy case of the Marburg variant of multiple sclerosis (MS). A 29-year-old woman developed acute and progressive neurological symptoms. A diagnosis of MS was suspected based on the patient's clinical background and brain MRI findings and the lack of evidence of malignancy on a brain biopsy. Despite the administration of typical treatment for MS, a fatal outcome occurred three months after disease onset. The autopsy revealed multiple inflammatory demyelinating lesions in the central nervous system. In addition, two noteworthy histopathological features were observed compared with prototypical MS. We evaluate the pathogenic differences between the Marburg type and prototypical MS by discussing the neuropathology and cerebrospinal fluid (CSF) findings of our case.

Cancer susceptibility and embryonic lethality in Mob1a/1b double-mutant mice

Mps one binder 1a (MOB1A) and MOB1B are key components of the Hippo signaling pathway and are mutated or inactivated in many human cancers. Here we show that intact Mob1a or Mob1b is essential for murine embryogenesis and that loss of the remaining WT Mob1 allele in Mob1a(Δ/Δ)1b(tr/+) or Mob1a(Δ/+)1b(tr/tr) mice results in tumor development. Because most of these cancers resembled trichilemmal carcinomas, we generated double-mutant mice bearing tamoxifen-inducible, keratinocyte-specific homozygous-null mutations of Mob1a and Mob1b (kDKO mice). kDKO mice showed hyperplastic keratinocyte progenitors and defective keratinocyte terminal differentiation and soon died of malnutrition. kDKO keratinocytes exhibited hyperproliferation, apoptotic resistance, impaired contact inhibition, enhanced progenitor self renewal, and increased centrosomes. Examination of Hippo pathway signaling in kDKO keratinocytes revealed that loss of Mob1a/b altered the activities of the downstream Hippo mediators LATS and YAP1. Similarly, YAP1 was activated in some human trichilemmal carcinomas, and some of these also exhibited MOB1A/1B inactivation. Our results clearly demonstrate that MOB1A and MOB1B have overlapping functions in skin homeostasis, and exert their roles as tumor suppressors by regulating downstream elements of the Hippo pathway.

Focal cortical dysplasia type IIa underlying epileptogenesis in patients with epilepsy associated with Sturge-Weber syndrome

In patients with epilepsy associated with Sturge-Weber syndrome (SWS), epileptogenesis has been suggested to be caused by chronic ischemia in cortical areas affected by leptomeningeal angiomatosis or by ischemia-related cortical malformations. However, this has not been fully verified electrophysiologically. We herein present two cases of SWS with medically intractable epilepsy in which the epileptogenic area involved focal cortical dysplasia (FCD) type IIa near the region of leptomeningeal angiomatosis. In both cases, the ictal-onset zones were identified by chronic subdural electrodes, and the presence of FCD type IIa was shown histopathologically. In SWS, especially in association with focal leptomeningeal angiomatosis, FCD may thus play a major role in epileptogenesis. FCD should therefore be demonstrated by the collective findings of perioperative neurophysiologic examination, anatomic and functional neuroimaging, and histopathologic examination.

Spinal endodermal cyst resembling an arachnoid cyst in appearance: Pitfalls in intraoperative diagnosis of cystic lesions

BACKGROUND

Surgical treatment of endodermal cysts requires total removal of the cyst wall during the first operation to prevent recurrence. Therefore, intraoperative pathological diagnosis plays an important role in determining the optimal surgical strategy. We present a rare case of a spinal endodermal cyst and discuss its diagnostic difficulty during the intraoperative pathological examination.

CASE DESCRIPTION

An 18-year-old male presented with progressive paraparesis and precordial oppression. Magnetic resonance (MR) imaging revealed an intradural extramedullary cystic mass having the same signal intensity as cerebrospinal fluid (CSF) without gadolinium enhancement at the T1-T2 level. The preoperative diagnosis was an endodermal or arachnoid cyst. The patient underwent surgery. An intraoperative frozen section showed a cyst wall consisting of loose, thin, fibrous tissue intermittently covered by flattened epithelium. The diagnosis was an arachnoid cyst. Accordingly, partial resection of the cyst wall was performed to create CSF communication between the cyst and subarachnoid space. However, the postoperative pathological diagnosis from permanent sections was an endodermal cyst, which was lined with ciliated columnar epithelium that was immunopositive for cytokeratin and epithelial membrane antigen. Subsequent paraffin embedding and immunostaining of the intraoperative frozen sample also confirmed patchy cytokeratin expression by all flattened epithelial cells. The patient's cyst had refilled 10 months after surgery, and he subsequently underwent fenestration of the cyst wall and placement of a cyst-subarachnoid shunt.

CONCLUSION

Examination of multiple samples from multiple sites or intraoperative immunostaining of frozen sections is recommended for accurate intraoperative diagnosis of endodermal cysts.

Molecular characteristics of glioblastoma with 1p/19q co-deletion

Recent developments in molecular analysis have revealed genetic alterations in human gliomas. Loss of heterozygosity (LOH) is a critical molecular marker for classification of human glioma, and is useful for predicting outcome. Our previous LOH study identified a small subgroup of glioblastoma (GBM), with 1p/19q co-deletion, with a favorable clinical outcome. In this study, we investigated molecular pathological features of eight GBM with 1p/19q co-deletion compared with "classic" GBM and anaplastic oligodendroglioma (AO). We estimated EGFR gene amplification, EGFRvIII expression, CDKN2A (p16) homozygous deletion, and isocitrate dehydrogenase 1/2 (IDH1/2) gene mutations. We also conducted an analysis of the expression of proneural genes (DLL3, OLIG2, SOX2). On histopathological review, only one GBM was diagnosed as glioblastoma with oligodendroglioma component (GBMO). Loss of chromosomes 10 and 17p is common, and neither IDH1/2 mutations nor EGFRvIII expression were detected in GBM with 1p/19q co-deletion. The expression profile revealed high expression of the OLIG2 gene in this subgroup. High expression of proneural gene OLIG2 without EGFRvIII expression may be associated with a favorable clinical outcome; however, IDH1/2 gene status and the extent of LOH regions may indicate that this small subgroup of GBM is a distinct genetic subgroup from oligodendroglial tumors.

Extensive loss of connexins in Baló's disease: evidence for an auto-antibody-independent astrocytopathy via impaired astrocyte-oligodendrocyte/myelin interaction

Extensive aquaporin-4 (AQP4) loss without perivascular deposition of either activated complement or immunoglobulins is a characteristic of Baló's disease. Our aim in this study was to investigate the relationship between astrocytopathy and demyelination in Baló's disease, focusing on connexins (Cx), which form gap junctions among glial cells and myelin. Autopsied specimens from four cases that provided seven actively demyelinating concentric lesions infiltrated with numerous CD68(+) macrophages were immunohistochemically examined for the astrocyte markers glial fibrillary acidic protein (GFAP), AQP4, Cx43, Cx30 and megalencephalic leukoencephalopathy with subcortical cyst 1 (MLC1). Specimens were also stained for oligodendrocyte/myelin markers, namely Cx32, Cx47, myelin-associated glycoprotein (MAG), myelin oligodendrocyte glycoprotein (MOG), oligodendrocyte-specific protein (OSP) and Nogo-A. Serum samples from six patients that had undergone magnetic resonance imaging, confirming a diagnosis of Baló's disease, were assayed for the presence of anti-Cx43, -Cx32 and -AQP4 antibodies. Despite the presence of numerous GFAP- and MLC1-positive astrocytes, there was a marked decrease in the levels of Cx43, Cx32 and Cx47. At the leading edges, Cx43 and AQP4 were mostly absent despite positive GFAP, MLC1, Cx32, Cx47, MOG, MAG, and OSP immunoreactivity. Of the six Baló's disease patients, none were positive for anti-Cxs or -AQP4 antibodies. Baló's disease is characterized by extensive loss of Cxs and AQP4, and a lack of auto-antibodies to Cxs and AQP4. Loss of Cx43 and AQP4 in the presence of other oligodendrocyte/myelin proteins at the leading edges suggests the possibility that auto-antibody-independent astrocytopathy may contribute to disease pathology via the disruption of astrocyte-oligodendrocyte/myelin interactions.

Differential activation of proapoptotic molecules between mouse and rat models of distal motor trigeminal denervation

BACKGROUND

We previously developed a rat trigeminal motor neuron axotomy model involving masseter and temporal muscle resection to study pathological changes of the central nucleus after peripheral nerve injury caused by oral surgery. Because motor neurons are reported to be more vulnerable to axotomy in mice than rats, we compared the degeneration process of the trigeminal motor nucleus in the rat model with a similar mouse model.

METHODS

We removed masseter and temporal muscles of adult mice or rats. Animals were sacrificed at 3, 7, 14, 28, 42, and 56 days post-operation, and the trigeminal motor nuclei were histologically analyzed.

RESULTS

Size reduction, but no neuronal loss, was seen in the trigeminal motor nuclei in both mice and rats. Time-dependent Noxa expression, starting at 1 week post-operation (wpo), was seen in the mouse model. By 8 wpo, mice expressed a higher level of Noxa than rats. Additionally, we noted persistent expression of cleaved caspase-3 in mice but not in rats. Conversely, apoptosis-inducing factor (AIF), which executes DNA fragmentation in the nucleus, was not translocated to the nucleus in either model.

CONCLUSIONS

Our findings indicate differential activation of motor neuron apoptosis pathways after axotomy in mice and rats. Lack of activation of caspase-independent pathways and distal end denervation in our model might be related to the survival of motor neurons after axonal injury. These findings could be relevant to future neuroprotective strategies for peripheral nerve injury caused by oral surgeries.

Different responses of benign and atypical meningiomas to gamma-knife radiosurgery: report of two cases with immunohistochemical analysis

Recent reports have shown that gamma-knife radiosurgery provides a safe and effective strategy for the management of brain tumors. To evaluate the role of stereotactic radiosurgery in the management of meningiomas, we investigated the histopathology of two patients. The patients, a 37-year-old man and a 54-year-old woman, presented with visual field disturbance or headache. Imaging studies demonstrated intracranial meningiomas--tentorial and sphenoid ridge, respectively. Each patient undewent subtotal surgical resection (more than 90% in both patients), followed by gamma-knife radiosurgery of the remnant tumor marginal doses of 15 Gy. Pathological examination of the original tumors revealed a meningothelial meningioma and an atypical meningioma, respectively. Enlargement of the remnant tumors 4 months after radiosurgery resulted in total surgical resection in both patients. Thirteen months later, the patient with the atypical meningioma underwent a third operation for early recurrence of the tumor. Histopathology was investigated, and MIB-1, p53, and bcl-2 labeling indexes (LI) were analyzed immunohistochemically. Histopathologically, the specimens showed necrosis and intratumoral vessel obliteration after radiosurgery in both cases. However, more remnant tumor cells survived in the atypical meningioma. Immunohistochemically, increased wild-type p53, decreased bcl-2 expression, and decreased MIB-1 LI were observed in the benign meningioma. In the atypical meningioma, on the contrary, MIB-1 LI was decreased and mutant-type p53 and bcl-2 expression were unchanged. The specimen from the third operation revealed an anaplastic meningioma, and MIB-1 LI was markedly increased. These findings suggest that the efficacy of radiosurgery may differ between benign and atypical meningiomas.

Stress-regulated transcription factor ATF4 promotes neoplastic transformation by suppressing expression of the INK4a/ARF cell senescence factors

Many cancers overexpress ATF4, a stress-induced transcription factor that promotes cell survival under hypoxic conditions and other stresses of the tumor microenvironment, but the potential contributions of ATF4 to oncogenesis itself have been little explored. Here, we report that ATF4 promotes oncogene-induced neoplastic transformation by suppressing the expression of cellular senescence-associated genes. Strikingly, primary embryo fibroblasts from ATF4-deficient mice were resistant to transformation by coexpression of H-ras(V12) and SV40 large T antigen. In wild-type cells these oncogenes induced expression of the murine Atf4 gene along with the cyclin-dependent kinase inhibitor Cdkn2a, which encodes the cell senescence-associated proteins p16INK4 and p19ARF. Elevated levels of ATF4 were sufficient to suppress expression of these proteins and drive oncogenic transformation. Conversely, genetic ablation of ATF4 led to constitutive expression of p16INK4a and p19ARF, triggering cellular senescence. Our findings define a central function for ATF4 in promoting oncogenic transformation by suppressing a central pathway of cellular senescence.

Association of Alzheimer disease pathology with abnormal lipid metabolism: the Hisayama Study

OBJECTIVE

The relationship between lipid profiles and Alzheimer disease (AD) pathology at the population level is unclear. We searched for evidence of AD-related pathologic risk of abnormal lipid metabolism.

METHODS

This study included brain specimens from a series of 147 autopsies performed between 1998 and 2003 of residents in Hisayama town, Japan (76 men and 71 women), who underwent clinical examinations in 1988. Lipid profiles, such as total cholesterol (TC), triglycerides, and high-density lipoprotein cholesterol (HDLC), were measured in 1988. Low-density lipoprotein cholesterol (LDLC) was calculated using the Friedewald formula. Neuritic plaques (NPs) were assessed according to the Consortium to Establish a Registry for Alzheimer's Disease guidelines (CERAD) and neurofibrillary tangles (NFTs) were assessed according to Braak stage. Associations between each lipid profile and AD pathology were examined by analysis of covariance and logistic regression analyses.

RESULTS

Adjusted means of TC, LDLC, TC/HDLC, LDLC/HDLC, and non-HDLC (defined as TC-HDLC) were significantly higher in subjects with NPs, even in sparse to moderate stages (CERAD = 1 or 2), compared to subjects without NPs in multivariate models including APOE ε4 carrier and other confounding factors. The subjects in the highest quartiles of these lipid profiles had significantly higher risks of NPs compared to subjects in the lower respective quartiles, which may suggest a threshold effect. Conversely, there was no relationship between any lipid profile and NFTs.

CONCLUSION

The results of this study suggest that dyslipidemia increases the risk of plaque-type pathology.

Concurrent spinal nerve root schwannoma and meningioma mimicking single-component schwannoma

We present a first case of concurrent tumors consisting of schwannoma and meningioma arising at the same spinal level in a patient without neurofibromatosis. A 49-year-old man without clinical evidence of neurofibromatosis presented with a 5-month history of right neck pain. MRI demonstrated an extradural tumor involving the right-sided C2 nerve root with a small intradural component. T1- and T2-weighted and contrast-enhanced MRI could not differentiate the intradural tumor as different from the extradural tumor. Total removal of the tumors was performed. No contiguity of the extradural tumor with the intradural tumor was seen. The intradural tumor attached strongly to the dura mater around the C2 nerve root exits. Intraoperative pathological diagnosis confirmed the extradural tumor as schwannoma and the intradural tumor as meningioma. We therefore thoroughly coagulated the dura mater adjacent to the intradural tumor and resected the dura mater around the nerve root exits together with the tumor. Pathological examination revealed that the resection edge of the extradural component consisted of a spinal nerve with thickened epineurium and was free of neoplastic cells. No schwannoma component was evident in the intradural tumor. No obvious transition thus existed between the extra- and intradural tumors. Distinguishing these tumors prior to surgery is critical for determining an optimal surgical plan, as schwannoma and meningioma require different surgical procedures. We therefore recommend a careful review of preoperative imaging with the possibility of concurrent tumors in mind.

An autopsied case of sporadic adult-onset amyotrophic lateral sclerosis with FUS-positive basophilic inclusions

Basophilic inclusions (BIs), which are characterized by their staining properties of being weakly argyrophilic, reactive with Nissl staining, and immunohistochemically negative for tau and transactive response (TAR) DNA-binding protein 43 (TDP-43), have been identified in patients with juvenile-onset amyotrophic lateral sclerosis (ALS) and adult-onset atypical ALS with ophthalmoplegia, autonomic dysfunction, cerebellar ataxia, or a frontal lobe syndrome. Mutations in the fused in sarcoma gene (FUS) have been reported in cases of familial and sporadic ALS, and FUS immunoreactivity has been demonstrated in basophilic inclusion body disease (BIBD), neuronal intermediate filament inclusion disease (NIFID), and atypical frontotemporal lobar degeneration with ubiquitin-positive and tau-negative inclusions (aFTLD-U). In the present study, we immunohistochemically and ultrastructurally studied an autopsy case of sporadic adult-onset ALS with numerous BIs. The patient presented with the classical clinical course of ALS since 75 years of age and died at age 79. Postmortem examination revealed that both Betz cells in the motor cortex and motor neurons in the spinal cord were affected. The substantia nigra was spared. Notably, BIs were frequently observed in the motor neurons of the anterior horns, the inferior olivary nuclei, and the basal nuclei of Meynert. BIs were immunopositive for p62, LC3, and FUS, but immunonegative for tau, TDP-43, and neurofilament. Ultrastructurally, BIs consisted of filamentous or granular structures associated with degenerated organelles with no limiting membrane. There were no Bunina bodies, skein-like inclusions, or Lewy-like inclusions. All exons and exon/intron boundaries of the FUS gene were sequenced but no mutations were identified.

Reappraisal of aquaporin-4 astrocytopathy in Asian neuromyelitis optica and multiple sclerosis patients

Selective aquaporin-4 (AQP4) loss and vasculocentric complement and immunoglobulin deposition are characteristic of neuromyelitis optica (NMO). We recently reported extensive AQP4 loss in demyelinated and myelinated layers of Baló's lesions without perivascular immunoglobulin and complement deposition. We aimed to reappraise AQP4 expression patterns in NMO and multiple sclerosis (MS). We evaluated AQP4 expression relative to glial fibrillary acidic protein, extent of demyelination, lesion staging (CD68 staining for macrophages), and perivascular deposition of complement and immunoglobulin in 11 cases with NMO and NMO spectrum disorders (NMOSD), five with MS and 30 with other neurological diseases. The lesions were classified as actively demyelinating (n = 66), chronic active (n = 86), chronic inactive (n = 48) and unclassified (n = 12). Six NMO/NMOSD and two MS cases showed preferential AQP4 loss beyond the demyelinated areas, irrespective of lesion staging. Five NMO and three MS cases showed AQP4 preservation even in actively demyelinating lesions, despite grave tissue destruction. Vasculocentric deposition of complement and immunoglobulin was detected only in NMO/NMOSD patients, with less than 30% of actively demyelinating lesions showing AQP4 loss. Our present and previous findings suggest that antibody-independent AQP4 loss can occur in heterogeneous demyelinating conditions, including NMO, Baló's disease and MS.

Persistent roles of signal transduction of platelet-derived growth factor B in genesis, growth, and anaplastic transformation of gliomas in an in-vivo serial transplantation model

We previously reported that retrovirally transduced platelet-derived growth factor-B (PDGFB) in glial progenitors of the rat cerebral white matter, subventricular zone, or brain stem induced malignant brain tumors closely resembling human glioblastoma (GBM). While human GBMs may progress over the period of several months to a few years, prospective, long-term in-vivo observation of histological changes of the tumor tissues is not feasible in these models, because the animals undergo rapid tumor progression and mortality within approximately 1 month. We thus performed successive, long-term in-vivo transplantation of the PDGFB-induced tumor cells into the rat cerebrum. Primary retroviral transduction of PDGFB in the glial progenitors of the rat basal ganglia induced malignant glioma resembling human GBM or anaplastic oligodendroglioma (AOL) consisting of relatively monomorphous tumor cells expressing markers for the oligodendrocyte lineage. In the course of long-term successive transplantation, tumor cells presented pleomorphism as well as focal GFAP expression. This suggests that secondary chromosomal aberration and dysregulation of gene expression following accelerated cell cycle by PDGFB stimulation would induce morphological and immunophenotypic changes in tumor cells. Furthermore, while the primary tumors contained only a minor fraction of proviral GFP-expressing or hemagglutinin-expressing cells, most tumor cells came to express these proviral genes in the course of serial transplantation suggesting a persistent role of PDGFB-expressing cells in maintenance and growth of the tumors. This model would be useful for investigation of the long-term effects of PDGFB stimulation in glioma tissues on anaplastic evolution.

A patient with a dysembryoplastic neuroepithelial tumor who underwent epilepsy surgery after initial seizure

BACKGROUND

Since dysembryoplastic neuroepithelial tumors (DNTs) are benign tumors that are frequently associated with long-standing medically intractable epilepsy, it is well known that the surgical strategy is resection of the associated epileptogenic zone as well as the tumor. However, the surgical strategy for DNT with a single seizure has not been fully discussed.

METHODS

We report an 8-year-old boy with DNT in the nondominant frontal lobe who underwent epilepsy surgery at 3 months after his initial seizure.

RESULTS

An intraoperative electrocorticogram revealed frequent paroxysmal cortical activity lateral to the tumor. Since resection of the tumor resulted in persistent paroxysmal activity in this cortex, additional resection was performed. The histological findings in the cortex revealed the presence of cortical dysplasia (CD) (Palmini type IIA). Lesionectomy alone might have left the epileptogenic CD.

CONCLUSION

It is thought that epilepsy surgery should be recommended in patients with typical neuroimaging findings of DNT, even if the patients had only one episode of seizure.

[Exacerbation of radiation induced meningioma due to hemorrhage after cerebral angiography: a case report]

We report the case of a 34-year-old woman who exhibited acute deterioration in her condition after cerebral angiography for evaluation of a large meningioma. She had undergone surgery and irradiation for a glioma in the right occipital lobe 23 years before this episode. She experienced incapacity at work. On CT and MRI, a large meningioma was detected on the left frontal convexity; this tumor was thought to be radiation-induced. Cerebral angiography was performed to assess the vascularization of the tumor. Her condition began to deteriorate 2.5 h after the cerebral angiography. CT revealed an increase in the mass of the tumor, and a high density area in the tumor. We immediately removed the tumor. Histopathological examination revealed the tumor to be a meningothelial meningioma. New hemorrhagic foci were identified in the tumor. In addition, macrophages containing hemosiderin were detected, and some of the tumor vessels exhibited hyaline degeneration. We suspected that angiography triggered bleeding in the meningioma, which was already predisposed to hemorrhage.

A simple and high-yield method for preparation of rat microglial cultures utilizing Aclar plastic film

Microglia are implicated in both neuroprotection and neurodegeneration, and are a key area of interest with respect to various CNS diseases. Until now, primary microglia prepared by various isolation methods have been widely used to investigate their role in CNS diseases. However, there are some problems with the current isolation methods, such as the numbers of animals required in order to obtain sufficient numbers of microglial cells due to low yields, and also the long periods of culture required. We herein describe a simple, high-yield method for isolating not only primary microglia, but also immortalized microglial cells. Our method allows for the isolation of an almost pure population of microglia with only two steps. First, a primary mixed neural culture was prepared from the brains of 3-day-old postnatal rats. Next, primary microglia were collected for 2 h by adhesion to Aclar plastic film. The average yield by this method was approximately 50 times higher than that of the conventional shaking method. Immortalized microglial cells could also be prepared based on this procedure. A plasmid vector encoding the SV40 large T antigen was transfected into the mixed neural culture using a calcium phosphate precipitation method. Then, proliferating immortalized microglia were collected after several weeks in a similar fashion. Several clones were obtained by limited dilution and one of the immortalized cell lines was designated SMK. The SMK cells exhibited markers specific for the microglia lineage, including Iba-1, CD11b, CD45, CD68, major histocompatibility complex (MHC) class I and MHC class II, but not for the astrocyte-specific markers, GFAP and glutamate aspartate transporter. SMK also showed phagocytic activity. In conclusion, this method resulted in a high-yield preparation of microglial cultures with ease and reproducibility.

Glial progenitors in the brainstem give rise to malignant gliomas by platelet-derived growth factor stimulation

Glial progenitors in the white matter and the subventricular zone are the major population of cycling cells in the postnatal central nervous system, and thought to be candidates for glioma-initiating cells. However, less is known about the dividing cell populations in the brainstem than those in the cerebrum, leading to the lag of basic understanding of brainstem gliomas. We herein demonstrate much fewer cycling glial progenitors exist in the brainstem than in the cerebrum. We also show that infecting brainstem glial progenitors with PDGFB-green fluorescent protein (GFP)-expressing retrovirus induced tumors that closely resembled human malignant gliomas. Of note, brainstem tumors grew more slowly than cerebral tumors induced by the same retrovirus, and >80% tumor cells in the brainstem consisted of GFP-positive, infected progenitors while GFP-positive cells in the cerebral tumors were <20%. These indicate that cerebral tumors progressed rapidly by recruiting resident progenitors via paracrine mechanism whereas brainstem tumors grew more slowly by clonal expansion of the infected population. The cerebral and brainstem glial progenitors similarly showed reversible dedifferentiation upon PDGF stimulation in vitro and did not show the intrinsic difference in terms of the responsiveness to PDGF. We therefore suggest that slower, monoclonal progression pattern of the brainstem tumors is at least partly due to the environmental factors including the cell density of the glial progenitors. Together, these findings are the first implications regarding the cell-of-origin and the gliomagenesis in the brainstem.

Insulin resistance is associated with the pathology of Alzheimer disease: the Hisayama study

OBJECTIVE

We examined the association between diabetes-related factors and pathology of Alzheimer disease (AD) to evaluate how diabetes affects the pathogenic process of AD.

METHODS

This study included specimens from a series of 135 autopsies of residents of the town of Hisayama in Fukuoka prefecture (74 men and 61 women) performed between 1998 and 2003, who underwent a 75-g oral glucose tolerance test in clinical examinations in 1988. We measured diabetes-related factors including fasting glucose, 2-hour post-load plasma glucose, fasting insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) in 1988. Neuritic plaques (NPs) were assessed according to the Consortium to Establish a Registry for Alzheimer's Disease guidelines and neurofibrillary tangles (NFTs) were assessed according to Braak stage. The associations between each factor and AD pathology were examined by analysis of covariance and logistic regression analyses.

RESULTS

Higher levels of 2-hour post-load plasma glucose, fasting insulin, and HOMA-IR were associated with increased risk for NPs after adjustment for age, sex, systolic blood pressure, total cholesterol, body mass index, habitual smoking, regular exercise, and cerebrovascular disease. However, there were no relationships between diabetes-related factors and NFTs. Regarding the effects of APOE genotype on the risk of AD pathology, the coexistence of hyperglycemia and APOE epsilon4 increased the risk for NP formation. A similar enhancement was observed for hyperinsulinemia and high HOMA-IR.

CONCLUSION

The results of this study suggest that hyperinsulinemia and hyperglycemia caused by insulin resistance accelerate NP formation in combination with the effects of APOE epsilon4.

MiRNA-196 is upregulated in glioblastoma but not in anaplastic astrocytoma and has prognostic significance

PURPOSE

MicroRNAs (miRNA) are short noncoding RNAs that can play critical roles in diverse biological processes. They are implicated in tumorigenesis and function both as tumor suppressors and as oncogenes. The clinical significance of miRNA expression profiles in malignant gliomas remains unclear.

EXPERIMENTAL DESIGN

In this study, we examined the expression levels of 365 mature human miRNAs in 12 malignant gliomas, including 8 glioblastomas and 4 anaplastic astrocytomas, using TaqMan real-time quantitative PCR arrays. A validation study was done to corroborate a subset of the results, including expression levels of miR-196a, -196b, -21, and -15b, by analyzing 92 malignant gliomas by conventional real-time PCR. We modeled the relationship between the expression levels of these miRNAs and the survival rate of 39 glioblastoma patients by Kaplan-Meier method and multivariate analysis.

RESULTS

Expression profiles in glioblastomas and anaplastic astrocytomas suggested that 16 miRNAs were candidate markers associated with the malignant progression of gliomas. Among them, miR-196a showed the most significant difference (P = 0.0038), with miR-196b also having a high significance (P = 0.0371). Both miRNAs showed increased expression levels in glioblastomas relative to both anaplastic astrocytomas and normal brains in the validation study. Furthermore, patients with high miR-196 expression levels showed significantly poorer survival by the Kaplan-Meier method (P = 0.0073). Multivariate analysis showed that miR-196 expression levels were an independent predictor of overall survival in all 39 glioblastoma patients (P = 0.021; hazard ratio, 2.81).

CONCLUSIONS

Our results suggest that miR-196 may play a role in the malignant progression of gliomas and may be a prognostic predictor in glioblastomas.

Utility of 3-T FLAIR and 3D short tau inversion recovery MR imaging in the preoperative diagnosis of hippocampal sclerosis: direct comparison with 1.5-T FLAIR MR imaging

PURPOSE

To examine the utility of fluid-attenuated inversion recovery (FLAIR) imaging and three-dimensional short tau inversion recovery (3DSTIR) imaging using a 3-Tesla (3-T) magnetic resonance (MR) imager in the preoperative evaluation of hippocampal sclerosis (HS).

METHODS

Thirteen patients with intractable medial temporal lobe epilepsy who underwent anterior temporal lobectomy with amygdalohippocampectomy were studied. MR images were obtained twice, once with a 1.5-T imager and once with a 3-T imager. The extent of hippocampal resection was determined according to the findings on intraoperative hippocampal electroencephalography. We compared the diagnostic utility of FLAIR for HS between 1.5-T and 3-T MR imaging. In addition, the relationship between the existence of hypointense areas in the hippocampus (HIAs) on 3DSTIR and the severity of HS pathology (as evaluated using Watson's grading) was examined. The relationship between postoperative seizure outcome and postoperatively remaining HIAs was also evaluated.

RESULTS

There was no difference between FLAIR images from 1.5-T and 3-T imaging in the detection of HS. With 3DSTIR, an HIA in unilateral hippocampus was observed in all of the nine cases exhibiting severe pathologic HS (Watson's grade III-V). In seven cases with HIA, the extent of hippocampal resection was smaller than the HIAs. Every case showed good seizure outcome (Engel's class I and II).

DISCUSSION

In the diagnosis of HS, no substantial difference was noted between 1.5-T and 3-T MR imaging. However, 3DSTIR using 3-T MR imaging is useful for evaluating the extent of HS, although postoperative HS remnants are not correlated with surgical outcomes.

Differential expression of CD44 variants among meningioma subtypes

Aims/background-CD44 is a widely distributed cell surface molecule which has numerous isoforms generated by alternative splicing. The diverse functions related to the CD44 variants (CD44v) have been reported in various physiological and pathological conditions. The pattern of expression of CD44v among meningioma subtypes was investigated to ascertain whether CD44 variants play a role in a variety of biological processes, such as epithelial differentiation and extracranial metastasis.Methods-Twenty three meningiomas were studied immunohistochemically using novel antibodies directed against CD44 isoforms. Six of the 23 samples were analysed by reverse transcription polymerase chain reaction (RT-PCR), followed by Southern blotting with CD44v specific probes.Results-In meningothelial, fibrous and anaplastic meningiomas, a standard form of CD44 was detected by RT-PCR and was homogeneously expressed in tumour cells when studied immunohistochemically. CD44v was not detected in these subtypes. In secretory meningiomas, however, CD44v isoforms were strongly expressed in the cell clusters that produce secretory granules and also accumulated in the granules. The population of tumour cells immunopositive for CD44v was similar to that which stained with antibodies directed against carcinoembryonic antigen, epithelial membrane antigen and ezrin. On RT-PCR with Southern blotting, only the secretory type showed high level expression of CD44v.Conclusions-CD44v in meningiomas is expressed in relation to tumour cell differentiation towards the epithelial type.

A 6-year-old girl with an extra-axial mass in the middle cranial fossa

A 6-year-old Japanese girl presented with psychomotor seizures. Magnetic resonance (MR) images disclosed a mass lesion in the left middle cranial fossa with an internal irregular-shaped area, which was hyperintense on T1-weighted images and hypointense on T2-weighted images. Gross total resection of the tumor was performed through left occipital craniotomy. The tumor was white-to-grayish hard tissue, focally showing blackish pigmentation. Histological, immunohistochemical and electron-microscopical analyses revealed that white-to-grayish hard tissue corresponded to an atypical meningioma, and the blackish pigmentation of the tumor was composed of non-neoplastic, reactive hyperplasia and colonization of meningeal melanocytes in the meningioma tissue. A meningioma with reactive hyperplasia and colonization of meningeal melanocytes is unusual, but it is clinically important to differentiate this entity from other melanocytic tumors.

Resveratrol-induced autophagy in human U373 glioma cells

Autophagy is an intracellular protein transport process leading to the degradation of organelles and long-lived proteins in eukaryotes. The down-regulation of autophagy observed in cancer cells has been associated with tumor progression. This study investigated autophagy induced by resveratrol, a natural compound, in human glioma cells. Glioma cells were exposed to resveratrol, and the cell growth and autophagic level were evaluated. Resveratrol inhibited growth and induced cell death in U373 glioma cells. When treated with resveratrol, glioma cells stably expressing GFP fused to LC3, recruited more GFP-LC3-labeled autophagosomes, and the percentage of cells with GFP-LC3-labeled autophagosomes increased. Furthermore, in resveratrol-treated glioma cells, pretreatment with P38 or ERK1/2 inhibitors reduced the autophagic level, suggesting that resveratrol-induced autophagy was positively regulated by P38 and the ERK1/2 pathway. The Akt/mTOR pathway was not involved in resveratrol-induced autophagy. Our results suggest that resveratrol has an anticancer effect on glioma cells by inducing autophagy.

The effects of dynein inhibition on the autophagic pathway in glioma cells

Autophagy has multiple physiological functions, including protein degradation, organelle turnover and the response of cancer cells to chemotherapy. Because autophagy is implicated in a number of diseases, a better understanding of the molecular mechanisms of autophagy is needed for therapeutic purposes, including rational design of drugs. Autophagy is a process that occurs in several steps as follows: formation of phagophores, formation of mature autophagosomes, targeting and trafficking of autophagosomes to lysosomes, formation of autolysosomes by fusion between autophagosomes and lysosomes, and finally, degradation of the autophagic bodies within the lysosomes. It has been suggested that autophagosome formation is driven by molecular motor machineries, and, once formed, autophagosomes need to reach lysosomes, enriched perinuclearly around the microtubule-organizing centre. While it is recognized that all these steps require the cytoskeletal network, little is known about the mechanisms involved. Here we assessed the role of cytoplasmic dynein in the autophagic process of human glioma cells to determine the part played by dynein in autophagy. We observed that chemical interference with dynein function led to an accumulation of autophagosomes, suggesting impaired autophagosome-lysosome fusion. In contrast, we found that overexpression of dynamitin, which disrupts the dynein complex, reduced the number of autophagosomes, suggesting the requirement of the dynein-dynactin interaction in the early membrane trafficking step in autophagosome formation. These results suggest that dynein plays a variety of crucial roles during the autophagic process in glioma cells.

Histological considerations of the cleavage plane for preservation of facial and cochlear nerve functions in vestibular schwannoma surgery

Object

The authors analyzed the tumor capsule and the tumor–nerve interface in vestibular schwannomas (VSs) to define the ideal cleavage plane for maximal tumor removal with preservation of facial and cochlear nerve functions.

Methods

Surgical specimens from 21 unilateral VSs were studied using classical H & E, Masson trichrome, and immunohistochemical staining against myelin basic protein.

Results

The authors observed a continuous thin connective tissue layer enveloping the surfaces of the tumors. Some nerve fibers, which were immunopositive to myelin basic protein and considered to be remnants of vestibular nerve fibers, were also identified widely beneath the connective tissue layer. These findings indicated that the socalled “tumor capsule” in VSs is the residual vestibular nerve tissue itself, consisting of the perineurium and underlying nerve fibers. There was no structure bordering the tumor parenchyma and the vestibular nerve fibers. In specimens of tumors removed en bloc with the cochlear nerves, the authors found that the connective tissue layer, corresponding to the perineurium of the cochlear nerve, clearly bordered the nerve fibers and tumor tissue.

Conclusions

Based on these histological observations, complete tumor resection can be achieved by removal of both tumor parenchyma and tumor capsule when a clear border between the tumor capsule and facial or cochlear nerve fibers can be identified intraoperatively. Conversely, when a severe adhesion between the tumor and facial or cochlear nerve fibers is observed, dissection of the vestibular nerve–tumor interface (the subcapsular or subperineurial dissection) is recommended for preservation of the functions of these cranial nerves.

Degenerative and protective reactions of the rat trigeminal motor nucleus after removal of the masseter and temporal muscles

BACKGROUND

Microsurgical reconstruction techniques have allowed treatment of advanced head and neck carcinomas; however, it remains difficult to achieve long-term, functional reconstruction of the faciocervical muscles. To address this issue, in this we developed a rat trigeminal nerve denervation model that closely simulates the effects of oral surgery.

METHODS

The rat trigeminal nerve denervation model was developed by removing the masseter and temporal muscles, and degeneration process of the trigeminal motor nucleus was investigated by immunohistochemistry with particular focus on microglial/astrocytic reactions and motoneuron degeneration.

RESULTS

Atrophy of the trigeminal motor nucleus was observed at 8 weeks after denervation. A microglial reaction peaked at 3 days post-operation, while an astrocytic reaction was evident within 2 weeks, and peaked around 4 weeks post-operation. Expression of the stress protein HSP27 and an autophagy marker Rab24 was also upregulated in the injured trigeminal motor nucleus.

CONCLUSIONS

The results from this study suggest that this model is a practical and useful tool help to develop a further understanding of the pathology of the trigeminal motor nucleus after surgical denervation.

Detailed anatomy of intracranial venous anomalies associated with atretic parietal cephaloceles revealed by high-resolution 3D-CISS and high-field T2-weighted reversed MR images

PURPOSE

The advancement of magnetic resonance (MR) imaging technology has revealed that intracranial venous anomalies, such as vertical embryonic positioning of the straight sinus (VEP of SS), are associated with atretic parietal cephaloceles. However, the precise anatomical relationships among the venous anomalies, superior sagittal sinus (SSS), cistern, and cephalocele have not been demonstrated. We compared the imaging features of conventional MR images and high-resolution 3-dimensional (3-D) MR images, such as Fourier-transformation-constructive interference in steady-state (CISS) images and T2-weighted reversed (T2R) images obtained on a 3-T MR machine.

METHODS

Three patients ranging in age from 1 to 18 years, with midline subscalp lesions, participated in this study. In two cases, the lesions were surgically excised and subjected to pathological examination.

RESULTS

In two children, 3-D MR images more clearly demonstrated anomalous veins, including bilateral internal cerebral veins, the great vein of Galen and the vertical position of the straight sinus in the falx, extending superiorly within the CSF tract in the posterior interhemispheric fissure. While the vertical straight sinus drained into the SSS, the CSF tract maintained a position posterior to the anomalous veins, ran through the SSS and extended to the skull defect. In one patient, ascending positioning of the anomalous vein from the inferior sagittal sinus to the SSS in the CSF space was observed; this could not be depicted on conventional MR images.

CONCLUSION

Detailed findings of the venous anomalies on 3-D MR images provide clues to the diagnosis of atretic cephalocele.

Prenatal diagnosis of trisomy 16 mosaicism manifested as pulmonary artery stenosis

Trisomy 16 mosaicism detected at midtrimester amniocentesis is rare and indicative of true fetal mosaicism. We report a case of mosaic trisomy 16 diagnosed by amniocentesis in which the sonographic findings included fetal pulmonary artery stenosis, a single umbilical artery, and early onset fetal growth restriction. The pregnancy was legally terminated. A review of previous reports suggests that abnormalities of outlet tracts are rarely encountered in fetuses with trisomy 16 mosaicism revealed via amniocentesis.

Prevalence of copy-number neutral LOH in glioblastomas revealed by genomewide analysis of laser-microdissected tissues

We have employed a laser-capture microdissection technique and single-nucleotide polymorphism arrays to characterize genomic alterations associated with the development of glioblastoma multiforme (GBM). Combined analysis of loss of heterozygosity (LOH) and copy number revealed that more than half (56.3%) of the 254 identified LOH loci showed no copy-number alteration, indicating the presence of copy-number neutral LOH (cnLOH). Furthermore, we found a GBM case that showed cnLOH in 18 of the 22 autosomes. These results were confirmed by quantitative real-time PCR, microsatellite analysis, and fluorescence in situ hybridization. The high rate of cnLOH suggests that epigenetic abnormalities of many genes are involved in the development and progression of GBMs.

Enhanced expression of NADPH oxidase Nox4 in human gliomas and its roles in cell proliferation and survival

Reactive oxygen species (ROS) have been attracting attention as mediators of various cell-signaling pathways. Nox-family NADPH oxidases have proven to be a major source of ROS production in various cell types and have crucial roles in various physiological and pathological processes. In this study, we show that Nox4, a member of Nox family, is prominently expressed in various neuroepithelial tumors by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical studies. We quantified Nox4 mRNA expression by real-time PCR in tumor specimens from 58 patients with astrocytomas and found that the expression levels of Nox4 mRNA in glioblastomas (WHO grade IV) were significantly higher than those in other astrocytomas (WHO grade II and III). In addition, we show that specific knockdown of Nox4 expression by RNA interference results in cell-growth inhibition and enhances induction of apoptosis by chemotherapeutic agents, such as cisplatin, in cultured glioma cell lines. Based on these observations, enhanced expression of Nox4 appears to be involved in cell proliferation and survival in glioma cells.