Inducement of tissue regeneration of harvested hamstring tendons in a rabbit model

OBJECTIVES

The objective of this study was to determine if the use of fascia lata as a tendon regeneration guide (placed into the tendon canal following harvesting the semitendinosus tendon) would improve the incidence of tissue regeneration and prevent fatty degeneration of the semitendinosus muscle.

MATERIALS AND METHODS

Bilateral semitendinosus tendons were harvested from rabbits using a tendon stripper. On the inducing graft (IG) side, the tendon canal and semitendinosus tibial attachment site were connected by the fascia lata, which was harvested at the same width as the semitendinosus tendon. On the control side, no special procedures were performed. Two groups of six rabbits were killed at post-operative weeks 4 and 8, respectively. In addition, three healthy rabbits were killed to obtain normal tissue. We evaluated the incidence of tendon tissue regeneration, cross-sectional area of the regenerated tendon tissue and proportion of fatty tissue in the semitendinosus muscle.

RESULTS

At post-operative week 8, the distal end of the regenerated tissue reached the vicinity of the tibial insertion on the control side in two of six specimens. On the IG side, the regenerated tissue maintained continuity with the tibial insertion in all specimens. The cross-sectional area of the IG side was significantly greater than that of the control side. The proportion of fatty tissue in the semitendinosus muscle on the IG side was comparable with that of the control side, but was significantly greater than that of the normal muscle.

CONCLUSIONS

Tendon tissue regenerated with the fascia lata graft was thicker than naturally occurring regenerated tissue. However, the proportion of fatty tissue in the semitendinosus muscle was greater than that of normal muscle.Cite this article: K. Tabuchi, T. Soejima, H. Murakami, K. Noguchi, N. Shiba, K. Nagata. Inducement of tissue regeneration of harvested hamstring tendons in a rabbit model. Bone Joint Res 2016;5:247-252. DOI: 10.1302/2046-3758.56.2000585.

Second allogeneic hematopoietic stem cell transplantation in children with severe aplastic anemia

The outcome of 55 children with severe aplastic anemia (SAA) who received a second hematopoietic stem cell transplantation (HSCT) was retrospectively analyzed using the registration data of the Japanese Society for Hematopoietic Cell Transplantation. The 5-year overall survival (OS) and failure-free survival (FFS) after the second transplantation were 82.9% (95% confidence interval (CI), 69.7-90.8)) and 81.2% (95% CI, 67.8-89.4), respectively. FFS was significantly better when the interval between the first and second transplantation was >60 days (88.9%; 95% CI, 73.0-95.7) than when it was ⩽60 days (61.4%; 95% CI, 33.3-80.5; P=0.026). All 12 patients who were conditioned with regimens containing fludarabine and melphalan were alive with hematopoietic recovery. These findings justify the recommendation of a second HSCT for children with SAA who have experienced graft failure after first HSCT.

Chronological changes in the collagen-type composition at tendon-bone interface in rabbits

Objectives

The purpose of this study was to evaluate chronological changes in the collagen-type composition at tendon–bone interface during tendon–bone healing and to clarify the continuity between Sharpey-like fibres and inner fibres of the tendon.

Methods

Male white rabbits were used to create an extra-articular bone–tendon graft model by grafting the extensor digitorum longus into a bone tunnel. Three rabbits were killed at two, four, eight, 12 and 26 weeks post-operatively. Elastica van Gieson staining was used to colour 5 µm coronal sections, which were examined under optical and polarised light microscopy. Immunostaining for type I, II and III collagen was also performed.

Results

Sharpey-like fibres comprised of type III collagen in the early phase were gradually replaced by type I collagen from 12 weeks onwards, until continuity between the Sharpey-like fibres and inner fibres of the tendon was achieved by 26 weeks.

Conclusions

Even in rabbits, which heal faster than humans, an observation period of at least 12 to 26 weeks is required, because the collagen-type composition of the Sharpey-like fibre bone–tendon connection may have insufficient pullout strength during this period. These results suggest that caution is necessary when permitting post-operative activity in humans who have undergone intra-bone tunnel grafts.

Ototoxicity: mechanisms of cochlear impairment and its prevention

Aminoglycosides, cisplatin, and non-steroidal anti-inflammatory drugs (NSAIDs) are widely used pharmacological agents. There is a possibility, however, that the use of these agents may induce transient or permanent hearing loss and tinnitus as side effects. Recent animal studies have clarified mechanisms leading to the ototoxicity induced by these agents, at least in part. The permanent hearing loss caused by aminoglycosides and cisplatin is suggested to be predominantly associated with the apoptotic death of outer hair cells. Both drugs generate reactive oxygen species (ROS) in the inner ear. ROS can activate cell-death pathways such as the c-Jun Nterminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) pathways, which in turn, induce hair cell apoptosis. On the other hand, the abuse of NSAIDs may transiently cause tinnitus and mild to moderate hearing loss. NSAIDs impair the active process of the outer hair cells and affect peripheral and central auditory neurons. Conversely, recent reports clarified that NSAIDs are potential therapeutic agents against cochlear injuries. In this review, recent findings from animal studies regarding the ototoxicity induced by aminoglycosides, cisplatin, and NSAIDs are summarized. Their ototoxic mechanisms are focused on.

[A case of long-term remission of small-cell lung cancer with multiple brain metastases]

The prognosis for patients with brain metastases of small-cell lung cancer is particularly dismal. We present a case of a 47- year-old man diagnosed with multiple brain tumors which, following surgery, were revealed to be metastatic small-cell lung carcinoma through a pathological examination and a subsequent post-operative chest CT. Whole brain irradiation (50 Gy) with ten courses of systemic chemotherapy (carboplatin 200 mg/m2 day 1; etoposide 60 mg/m2 day 1-5) was applied. On the radiological examination, the lesions of the lung and brain gradually disappeared three and five years after the diagnosis, respectively. Sixteen years after diagnosis of the metastatic small cell carcinoma, the patient is disease-free and his ADL is excellent. This is an extremely rare case of small-cell lung cancer with multiple brain metastases in terms of showing a long- term remission.

Flexible a-Si Solar Cells with Plastic Film Substrate

An amorphous silicon solar cell deposited on plastic film substrate has been studied. The solar cell has a new monolithic series-connected structure called SCAF, and will be fabricated by a newly developed fabrication process based on “Stepping Roll” film deposition system.

The process was compared with the conventional glass solar cell process. Preliminary results for small and large area SCAF solar cells were presented and discussed.

[Case of an idiopathic dissecting aneurysm of the superficial temporal artery: a case report]

Aneurysms of the superficial temporal artery are usually traumatic in origin an are pseudoaneurysms. We present a rare case of an idiopathic dissecting aneurysm of the superficial temporal artery in a 40-year-old man without history of trauma. The patient had a pulsatile mass in the left temporal region. Angiography showed a fusiform dilatation at the left superficial temporal artery and both the true lumen and the false lumen were recognized. Resection of the aneurysm was performed. Postoperatively, the patients complaints disappeared completely. Histopathological examination of the specimen revealed a dissecting aneurysm. We investigated the histological findings by comparing them to angiographical findings.

A case of brain metastasis from pulmonary giant cell carcinoma

A 74-year old female was admitted to our hospital due to sudden right hemiparesis. Precontrast brain computed tomography (CT) revealed multiple high-density masses consistent with multiple hemorrhage, and chest CT scan demonstrated a mass in the left lung field without hemorrhage. Follow-up CT showed enlargement of the multiple intracerebral hemorrhages. A diagnosis was made of brain metastasis from a rare pure giant cell carcinoma (GCC) of the lung.

Cochlear protection from acoustic injury by inhibitors of p38 mitogen-activated protein kinase and sequestosome 1 stress protein

This study evaluated the protective role of p38 mitogen-activated protein kinase (p38 MAPK) inhibitors and sequestosome 1 (Sqstm1/A170/p62), a stress-induced signal modulator, in acoustic injury of the cochlea in mice. Two weeks after the exposure of mice to acoustic stress, threshold shifts of the auditory brainstem response (ABR) from the pre-exposure level and hair cell loss were evaluated. The activation of p38 MAPK was observed in cochlea by immunostaining 4 h after acoustic stress. To examine the role of p38 MAPK in tissue injury, its inhibitors were i.p. injected into male wild-type C57BL mice before the acoustic overexposure. The inhibitors SB202190 and SB203580 but not the inactive analogue SB202474 dose-dependently decreased the auditory threshold shift and outer hair cell loss induced by acoustic overexposure, suggesting the involvement of p38 MAPK in ototoxicity. We found that acoustic overexposure induced the up-regulation of Sqstm1 mRNA expression in the cochlea of wild-type mice and that SQSTM1-deficient mice exhibited an enhanced ABR threshold shift and hair cell loss, suggesting a role of SQSTM1 in the protection of tissue from acoustic stress.

Photophobia as the visual manifestation of chiasmal compression by unruptured anterior communicating artery aneurysm. Case report

A 37-year-old woman presented with photophobia without visual loss associated with chiasmal compression by an unruptured anterior communicating artery (AcomA) aneurysm. She had suffered progressive photophobia for one year. Neuroimaging indicated an AcomA aneurysm attached to the chiasm. Photophobia was resolved following clipping of the aneurysm. AcomA aneurysm should be considered in patients who experience photophobia without visual loss.

Increased anxiety-like behavior in mice lacking the inhibitory synapse cell adhesion molecule neuroligin 2

Neuroligins (NL) are postsynaptic cell adhesion molecules that are thought to specify synapse properties. Previous studies showed that mutant mice carrying an autism-associated point mutation in NL3 exhibit social interaction deficits, enhanced inhibitory synaptic function and increased staining of inhibitory synaptic puncta without changes in overall inhibitory synapse numbers. In contrast, mutant mice lacking NL2 displayed decreased inhibitory synaptic function. These studies raised two relevant questions. First, does NL2 deletion impair inhibitory synaptic function by altering the number of inhibitory synapses, or by changing their efficacy? Second, does this effect of NL2 deletion on inhibition produce behavioral changes? We now show that although NL2-deficient mice exhibit an apparent decrease in number of inhibitory synaptic puncta, the number of symmetric synapses as determined by electron microscopy is unaltered, suggesting that NL2 deletion impairs the function of inhibitory synapses without decreasing their numbers. This decrease in inhibitory synaptic function in NL2-deficient mice correlates with a discrete behavioral phenotype that includes a marked increase in anxiety-like behavior, a decrease in pain sensitivity and a slight decrease in motor co-ordination. This work confirms that NL2 modulates inhibitory synaptic function and is the first demonstration that global deletion of NL2 can lead to a selective behavioral phenotype.

Simultaneous occurrence of subarachnoid hemorrhage due to ruptured aneurysm and remote brainstem hematoma--case report

A 48-year-old woman presented with simultaneous aneurysmal subarachnoid hemorrhage (SAH) and remote intracerebral hemorrhage manifesting as sudden onset of severe headache, left hemiparesis, and diplopia. Emergent computed tomography revealed localized SAH in the interpeduncular cistern, and a remote brainstem hematoma in the right dorsolateral tegment. Neuroimaging found no signs of vascular anomaly in the brainstem. The aneurysm at the basilar artery and superior cerebellar artery bifurcation was successfully embolized using coils. Her postoperative neurological status was improved except for slight diplopia. The causes of this extremely rare case of simultaneous occurrence of aneurysmal SAH and remote brainstem hematoma in the dorsolateral tegment remain obscure.

Role of inhibitor of apoptosis protein in gentamicin-induced cochlear hair cell damage

Apoptotic cell death is considered to play a key role in gentamicin-induced cochlear hair cell loss. Inhibitor of apoptosis proteins (IAPs) are important regulators of apoptosis that can prevent activation of effector caspases. This study was designed to investigate the possible involvement of X-linked inhibitor of apoptosis protein (XIAP) in hair cell death due to gentamicin. Basal turn organ of Corti explants from postnatal day (p) p3 or p4 rats were maintained in tissue culture and were exposed to 35 muM gentamicin for up to 48 h. Effects of specific XIAP inhibitors on gentamicin-induced hair cell loss and caspase-3 activation were examined. XIAP inhibitors increased gentamicin-induced hair cell loss but an inactive analog had no effect. Caspase-3 activation was primarily observed at 36 or 48 h in gentamicin-treated hair cells, whereas caspase-3 activation peaked at 24-36 h when explants were treated with gentamicin and an XIAP inhibitor. The inhibitors alone had no effect on hair cells. Finally, a caspase-3 inhibitor decreased caspase-3 activation and hair cell loss induced by gentamicin and an XIAP inhibitor, but caspase-8 and -9 inhibitors did not. The results indicate that XIAP normally acts to decrease caspase-3 activation and hair cell loss during gentamicin ototoxicity, as part of a protective response to potentially damaging stimuli.

Locomotion ability variation among instars of the bean bug, Riptortus pedestris (Fabricius) (Heteroptera: Alydidae) nymphs

The nymphal locomotion ability (walking distance) of the stenophagous bean bug Riptortus pedestris (Fabricius) was studied in each instar. We measured the walking distance using two systems. The walking distance in photophase was measured for 6 h using a tracking system with a charge coupled device (CCD) camera and computer software. The daily activity of nymphs was measured by an actograph system counting the number of infrared beam intercepts. The actograph data were converted to distance using a linear regression against the data of the tracking system. The longevity of nymphs without food was also studied to estimate the potential walking distance. Using both the tracking and actograph systems, it was determined that first instars walked less than the other instars (only 10.7 m within 6 h). The second to fifth instars could move 20-25 m within 6 h, and this distance did not differ among instar. This indicates that first instars seldom move after hatching in the field. The walking distance for 24 h varied and was greatest for the third instars (80.8 m). The potential longevity of nymphs was found to increase with instar age. Potential locomotion ability (walking distance for 24 hxpotential longevity) was high in the third to fifth instars (approximately 340 m). The potential locomotion ability for the second instars was relatively low compared with the elder instars (approximately 180 m). From these results, nymphs of R. pedestris seem to adapt by identifying feeding site locations after hatching and elder instars may be able to find a novel feeding site after the degradation of previous habitat.

Loss of cytokeratin 13 expression in squamous cell carcinoma of the tongue is a possible sign for local recurrence

Cytokeratin (CK) 13 is an intermediate filament protein that is expressed in a cell-type-specific manner, in the tongue and occasionally in tongue squamous cell carcinoma (SCC). Correlations between the clinical features of patients with SCC and CK13 expression in the tumor are here investigated along with CK13's utility as a marker for tongue cancer status. Samples from 121 patients with SCC of the tongue were examined by immunohistochemistry with antibodies against CK13. Correlations between the expression level of CK13 in the tumor and the patients' clinical features were statistically analyzed by univariate and multivariate methods. Univariate analysis showed a more relevant number of local recurrence (P = 0.04) in CK13-negative staining patients. In addition, CK13-negative cases were associated with local recurrence by multiple logistic regression analysis (OR: 3.36; 95% CI: 1.044-10.78; P = 0.04). Our results suggest that the loss of CK13 expression indicates tumors with a high potential for recurrence, and thus CK13 could be useful for determining the best course of treatment.

[A case of hydrocephalus in follow-up of post-traumatic subdural effusion]

We report an interesting case of hydrocephalus following traumatic subdural effusion. A 50-year-old male was diagnosed as a traumatic subdural effusion. Three months later, he was transferred to our hospital again because of conscious disturbance and incontinence. Emergent CT showed characteristic hydrocephalus. The lateral ventricle and the third ventricle were remarkably enlarged. After Ventriculo-peritoneal shunt, the symptoms and radiographical findings were resolved. Both the compression of arachnoid villi around the superior saggital sinus and stenosis of the aqueduct by subdural effusion could be associated with the cause of hydrocephalus in this case.

Stereotactic radiation therapy with chemotherapy in the management of recurrent medulloblastomas

Medulloblastomas are highly lethal tumors when they recur. Very few patients survive with conventional treatment. This report documents the preliminary study results of a treatment for recurrent medulloblastomas consisting of stereotactic radiation therapy (SRT) with chemotherapy. Four patients had local recurrence without apparent metastases and 8 patients had metastases with or without local recurrence. Twelve patients with 18 lesions underwent SRT as a single session (n=8) or in a hypofractionated manner (n=10) using a gamma knife or modified linear accelerator. All patients then received systemic chemotherapy. Five patients were treated with one to two sequential courses of high-dose chemotherapy with peripheral blood stem cell transplantation. The reduction in tumor size after SRT was often remarkable. Fourteen of 18 lesions treated disappeared 1-6 months after SRT. Two of 4 patients who had local recurrences without apparent metastasis at the time of SRT are alive without evidence of disease 70 and 72 months after SRT, respectively. In contrast, all 8 patients with metastasis had new lesions either in the spinal canal or on the surface of the brain outside the target area of SRT. Median progression-free survival and overall survival from the time of SRT were 9 and 19 months, respectively. The Kaplan-Meier estimates of PFS and overall survival at 3 years were 17 and 25%, respectively. One patient had brainstem edema after SRT causing bulbar palsy and quadriparesis. One patient died of toxicity of chemotherapy. Our experience suggests that local recurrence can be controlled by SRT with chemotherapy but survival of patients with metastases can not be improved effectively by SRT in conjunction with aggressive chemotherapy.

Detection of JC virus DNA sequences in brain tumors in pediatric patients

OBJECT

The JC virus is a human neurotropic polyomavirus that causes progressive multifocal leukoencephalopathy and is closely related to simian virus 40. Several recent reports have indicated a possible association between the JC virus and the development of various human brain tumors. The authors examined the presence of JC virus DNA sequences in primary brain tumors in pediatric patients to evaluate the hypothesis that particular brain tumors can arise in the pediatric population as a consequence of infection with the JC virus.

METHODS

Genomic DNA sequences were isolated from 62 brain tumors (32 medulloblastomas, 18 ependymomas, five choroid plexus papillomas, and seven pilocytic astrocytomas) and analyzed for the presence of JC virus DNA by Southern blot hybridization and direct sequencing. The JC virus DNA sequence was detected in five ependymomas and one choroid plexus papilloma. Immunohistochemical studies revealed nuclear expression of the large T-antigen in a choroid plexus papilloma. None of the medulloblastomas or pilocytic astrocytomas contained JC virus DNA.

CONCLUSIONS

The results of this study provide molecular evidence of the association between JC virus and the development of certain ependymomas and choroid plexus papillomas.

Thrombus and encapsulated hematoma in cerebral cavernous malformations

Thrombi, encapsulated hematomas, and granulation tissue are frequently seen in cerebral cavernous malformations (CCMs). We investigated the role that these histological changes play in repeated hemorrhages in CCMs as well as lesion growth, examining specimens of CCMs surgically harvested from 20 patients. The immunohistochemical study included thrombomodulin (TM) and endothelial cell protein C receptor (EPCR), which are important regulators of blood coagulation. Thick capsules, which contained blood degradation product, were seen in cases with encapsulated hematomas. Clusters of sinusoidal vessels were found outside of these thick capsules. Granulation tissue with inflammatory infiltrates and capillaries was seen in 4 cases with non-capsulated hematomas. Organizing thrombi were seen in sinusoidal vessels in 15 out of 20 cases. Factor VIII-related antigen staining demonstrated numerous capillaries in and around organizing thrombi and within the thickened vessel walls as well as in both the inner and outer sides of the hematoma capsule. TM and EPCR were positive in the endothelial cells of these capillaries, whereas they were negative in those of capillaries in the brain surrounding the lesions. Our study suggests that thrombosed sinusoidal blood vessels could gradually expand by repeated bleeding from numerous capillaries inside the wall and become encapsulated hematomas, and capillaries outside the thickened vessel wall could become sinusoidal blood vessels. Thrombosis within cerebral venules could be one of the causal factors of CCMs.

Capillary hemangioma of the central nervous system: a comparative study with lobular capillary hemangioma of the skin

Capillary hemangiomas have rarely been reported to develop in the brain or spinal cord. Here we report the histological and immunohistochemical features of ten cases of central nervous system capillary hemangiomas (CNSCH) and compare these to those of lobular capillary hemangioma (LCH) of the skin. CNSCH showed a lobular architecture with lobules that were separated by fibrous tissue septa in six cases. The lobules were composed of numerous, tightly packed, capillary-sized vessels. A highly cellular area was seen in six cases. A blood-filled cavernous space and fibroendothelial papillae that mimicked papillary endothelial hyperplasia were seen in four cases. Stromal edema was observed in nine cases. These features were not statistically different from those of LCH of the skin, although the highly cellular area was more prominent and more frequent in cases of CNSCH. Immunohistochemical studies demonstrated no positive staining of endothelial cells within either lesion for erythrocyte-type glucose transporter protein, which is a selective marker for capillary hemangioma of infancy. Vascular endothelial growth factor immunostaining demonstrated positive cells in the solid or immature-appearing areas without vessel lumen formation in both lesions. Some of the endothelial cells and stromal cells were positive for glucocorticoid receptor immunostaining. The MIB-1 index of CNSCH was variable (mean 5.6%) and the apoptotic index of CNSCH was significantly lower than that of LCH of the skin. CNSCH are benign lesions with histological and immunohistochemical features similar to those of LCH of the skin.

Peritoneal Shunt Tube Migration Into the Stomach-Case Report-

A 47-year-old man presented with repeated headache and feverishness 3.5 years after undergoing ventriculoperitoneal shunt surgery for normal pressure hydrocephalus secondary to subarachnoid hemorrhage. Abdominal computed tomography revealed that the peritoneal catheter was encased by fibrous tissue and the distal end of the catheter had migrated into the stomach. The diagnosis was spontaneous gastric perforation by the ventriculoperitoneal shunt. The fibrous tissue was expected to seal the very small gastric perforation, so the catheter was successfully extracted through a scalp incision without abdominal surgical intervention.

Detrended fluctuation analysis of genome-wide copy number profiles of glioblastomas using array-based comparative genomic hybridization

We examined whole genomic aberrations of biopsied samples from 19 independent glioblastomas by array-based comparative genomic hybridization analysis. The highest frequencies of copy number gains were observed on RFC2 (73.3%), EGFR (63.2%), and FGR, ELN, CDKN1C , FES, TOP2A, and ARSA (57.9% each). The highest frequencies of copy number losses were detected on TBR1 (52.6%), BMI1 (52.6%), EGR2 (47.4%), DMBT1 (47.4%), MTAP (42.1%), and FGFR2 (42.1%). The copy number gains of CDKN1C and INS and the copy number losses of TBR1 were significantly correlated with longer survival of patients. High-level amplifications were identified on EGFR, SAS/CDK4, PDGFRA, MDM2, and ARSA. These genes are assumed to be involved in tumorigenesis or progression of glioblastomas. The first attempts to apply detrended fluctuation analysis to copy number profiles by considering the reading direction as the time axis demonstrated that higher long-term fractal scaling exponents (alpha2) correlated well with longer survival of glioblastoma patients. The present study indicates that array-based comparative genomic hybridization analysis has great potential for assessment of copy number changes and altered chromosomal regions of brain tumors. Furthermore, we show that nonlinear analysis methods of whole genome copy number profiles may provide prognostic information about glioblastoma patients.

Detrended fluctuation analysis of genome-wide copy number profiles of glioblastomas using array-based comparative genomic hybridization

We examined whole genomic aberrations of biopsied samples from 19 independent glioblastomas by array-based comparative genomic hybridization analysis. The highest frequencies of copy number gains were observed on RFC2 (73.3%), EGFR (63.2%), and FGR, ELN, CDKN1C , FES, TOP2A, and ARSA (57.9% each). The highest frequencies of copy number losses were detected on TBR1 (52.6%), BMI1 (52.6%), EGR2 (47.4%), DMBT1 (47.4%), MTAP (42.1%), and FGFR2 (42.1%). The copy number gains of CDKN1C and INS and the copy number losses of TBR1 were significantly correlated with longer survival of patients. High-level amplifications were identified on EGFR, SAS/CDK4, PDGFRA, MDM2, and ARSA. These genes are assumed to be involved in tumorigenesis or progression of glioblastomas. The first attempts to apply detrended fluctuation analysis to copy number profiles by considering the reading direction as the time axis demonstrated that higher long-term fractal scaling exponents (alpha2) correlated well with longer survival of glioblastoma patients. The present study indicates that array-based comparative genomic hybridization analysis has great potential for assessment of copy number changes and altered chromosomal regions of brain tumors. Furthermore, we show that nonlinear analysis methods of whole genome copy number profiles may provide prognostic information about glioblastoma patients.

Induction of the DNA repair gene O6-methylguanine—DNA methyltransferase by dexamethasone in glioblastomas

Object. The DNA repair enzyme O6-methylguanine—DNA methyltransferase (MGMT) inhibits the cytotoxic effect of alkylating agents on tumor cells. The presence of two nonconsensus glucocorticoid-responsive elements in the human MGMT promoter region indicates the potential regulation of MGMT expression by glucocorticoid agents. This study was performed to elucidate whether dexamethasone affects the expression of MGMT in glioblastoma multiforme (GBM) cells, thereby limiting the benefit of chemotherapeutic alkylating agents.

Methods. Four GBM cell lines (A172, T98G, U138MG, and U87MG) were exposed to the alkylating agent 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) with or without dexamethasone. The expression levels of MGMT were correlated with the cytotoxic effects of ACNU in GBM cells. In the presence of ACNU alone, dexamethasone alone, and the combination of both agents, messenger RNA expression of MGMT was induced to varying degrees with the highest increases seen in the later conditions. This dexamethasone-dependent induction of the MGMT gene was even observed in U87MG cells in which the promoter is methylated, although the absolute expression of MGMT mRNA was the lowest in that cell line. The induction of MGMT by dexamethasone was associated with an increased resistance of these cells to ACNU.

Conclusions. These results indicate that dexamethasone-mediated upregulation of MGMT limits the efficiency of alkylating agents in the treatment of malignant gliomas.

Expression of the Wilms' tumor gene product WT1 in glioblastomas and medulloblastomas

The Wilms' tumor gene WT1 was first identified as the gene responsible for a childhood renal tumor, Wilms' tumor. This gene encodes for a zinc finger-containing transcription factor. Although originally identified as a tumor suppressor gene, WT1 is overexpressed in a variety of hematologic malignancies and solid tumors. Recently, WT1 protein has been considered as a new molecular target of cancer immunotherapy for several solid tumors. In the present study, we investigated the expression of WT1 protein and WT1 mRNA in glioblastomas and medulloblastomas. Forty-eight of 51 glioblastoma samples (94%) showed immunohistochemically positive staining of WT1 protein, whereas all 10 medulloblastomas examined were negative. According to the immunohistochemical expression of WT1 protein, WT1 mRNA was also highly expressed in the same glioblastoma tissue. Our results suggest that the WT1 gene may play an important role in the tumorigenesis of glioblastoma, in contrast to medulloblastoma, and be integral in the development of the immunotherapy targeting WT1 protein in patients with glioblastoma.

Combined proteomic approach with SELDI-TOF-MS and peptide mass fingerprinting identified the rapid increase of monomeric transthyretin in rat cerebrospinal fluid after transient focal cerebral ischemia

Several proteins are known to be markedly expressed in the brain during cerebral ischemia, however the change in protein profiles within the cerebrospinal fluid (CSF) after an ischemic insult has not been fully elucidated. We studied the changes in the CSF proteome in rat transient middle cerebral artery occlusion model. Surface enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS) was used to detect the time-course changes in CSF protein patterns after transient focal brain ischemia. According to hierarchical cluster analysis by self-organising tree algorism (SOTA), the temporal pattern of protein peaks was divided into four groups: acute increase group, chronic increase group, gradual decrease group and unchanged group. In the acute increase group, the expression of a 13.6-kDa protein was markedly increased during the acute phase. The 13.6-kDa protein was identified as monomeric form of transthyretin using two-dimensional electrophoresis and peptide mass fingerprinting based on matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The monomeric transthyretin may represent an ischemia-specific CSF marker to indicate the sequential changes according to ischemic insults of the brain.

Increased cytotoxicity of soluble Fas ligand by fusing isoleucine zipper motif

Fas (CD95) ligand (FasL) has the ability to induce apoptosis in Fas-expressing glioma cells by binding to Fas. Several molecular species have been designed to be soluble Fas ligands for therapeutic purposes. We successfully constructed a chimeric soluble FasL by fusing an isoleucine zipper motif for self-oligomerization and a FLAG sequence to the extracellular domain of the human Fas ligand (FIZ-shFasL). The cytotoxic effect of FIZ-shFasL on Jurkat cells was equivalent to that of membrane-bound FasL and approximately 10-fold stronger than that of agonistic anti-Fas antibody (CH-11). Flow cytometric analysis demonstrated that the differential Fas expression of human brain tumor cell lines partially correlated with levels of apoptosis through FIZ-shFasL. The upper limit of FIZ-shFasL for safe systemic administration to rat is estimated as below 2 microg/ml in plasma concentration. FIZ-shFasL could be applicable as a therapeutic agent for cancer.

Identification of pleiotrophin in conditioned medium secreted from neural stem cells by SELDI-TOF and SELDI-tandem mass spectrometry

Neural stem cells (NSCs) are multipotential progenitor cells that have self-renewal activity. Since the fates of the NSCs in situ depend on their niche containing growth factors and cytokines, we performed surface enhanced laser desorption/ionization time-of flight mass spectrometry (SELDI-TOF-MS) to screen for differentially secreted proteins in conditioned medium of neural stem cells and compared with that of NIH3T3 cells. A 15.3-kDa protein detected only in the conditioned medium of neural stem cells was determined as pleiotrophin (PTN) by SELDI-TOF-MS and ProteinChip-tandem MS systems. Identification of pleiotrophin was further confirmed by one-dimensional SDS gel electrophoresis and Edman degradation analysis. The mRNA transcripts of PTN and its receptors [receptor protein tyrosine phosphatase (RPTP) beta/zeta, N-syndecan and anaplastic lymphoma kinase (ALK)] were detected in neurosphere, suggesting that pleiotrophin signaling systems are present in the neural stem cells and are involved in the modulation of fate of neural stem cells.

Capillary hemangioma of the central nervous system

Object. Capillary hemangiomas are benign tumors or tumorlike lesions that originate from blood vessels and have rarely been reported to develop in the brain or spinal cord. The authors summarize the clinical and histological features of capillary hemangiomas of the central nervous system (CNS).

Methods. The clinical features, imaging characteristics, and outcomes in 10 patients with CNS capillary hemangiomas were reviewed. Histological studies included immunostaining with CD31, α-smooth muscle actin, vascular endothelial growth factor, and Ki-67 antigen. Three patients with lesions in the brain presented with symptoms of increased intracranial pressure or seizures. Seven patients with lesions in the spinal cord presented with progressive sensorimotor disturbances of the lower limbs. Computerized tomography and magnetic resonance imaging demonstrated well-defined, enhancing lesions associated with marked perifocal edema. Angiography demonstrated hypervascular lesions, which have not recurred after resection. In two cases, multiple satellite lesions resolved after the systemic administration of steroid drugs or interferon-α. Histologically, all lesions were consistent with findings of capillary hemangioma of the skin or soft tissues. The CNS lesions differed significantly from other vascular neoplasms, such as hemangioendotheliomas, hemangiopericytomas, and hemangioblastomas.

Conclusions. Capillary hemangiomas of the CNS are benign lesions that can be surgically removed and cured without adjuvant therapy.

Molecular analysis of astrocytoma associated with Turcot syndrome type 1--case report

A 49-year-old man presented with a brain tumor and colon carcinoma. The patient had been treated under diagnoses of hereditary non-polyposis colorectal cancer syndrome and Muir-Torre syndrome. Magnetic resonance imaging revealed a mass lesion in the right frontal lobe with diffuse high intensity on T2-weighted and fluid-attenuated inversion recovery images. A few small lesions were enhanced by gadolinium on the T1-weighted images. Histological examination revealed the brain neoplasm was astrocytoma grade III according to the World Health Organization classification. Molecular genetic analysis detected microsatellite instability and p53 mutation only in the tumor tissue, indicating a failure of the deoxyribonucleic acid mismatch repair system. These results suggest that inactivation of mismatch repair system and p53 is closely associated with the tumorigenesis of this neoplasm. The final diagnosis was Turcot syndrome type 1.

Neuroendoscopic Transventricular Surgery for Suprasellar Cystic Mass Lesions Such as Cystic Craniopharyngioma and Rathke Cleft Cyst

Cystic mass lesions in the suprasellar cistern are often associated with neurological deficits, cognitive disorders, and endocrinological impairments. Many surgical approaches are available to treat these mass lesions, but are technically difficult and cannot remove the lesion completely without risking damage to neurological and endocrinological functions due to the proximity to the surrounding structures. Neuroendoscopic transventricular surgery was performed using a ventricular fiberscope for three patients with craniopharyngiomas and two patients with Rathke cleft cysts, with gamma knife radiosurgery for craniopharyngiomas. The endoscopic transventricular approach is safe and minimally invasive for congenital benign suprasellar cystic lesions, especially arachnoid cysts.

[Neuroendoscopic treatment for Rathke's cleft cyst: transventricular approach to suprasellar cystic lesion]

We report a case of a Rathke's cleft cyst, which was successfully treated by neuroendoscopy. The endoscopic procedure for the intra-suprasellar cystic lesion used the transventricular approach, similar to that of third ventriculostomy. A 66-year-old woman suffered from headache, nausea and constriction of the visual field. Magnetic resonance imaging (MRI) on admission showed an intra-suprasellar cystic lesion. Biopsy of the cyst wall and fenestration of the floor of the third ventricle was performed using an endoscopic transventricular approach. The cyst content was totally aspirated, using a suction system which was connected to the operation channel of the endoscope. The histological diagnosis was Rathke's cleft cyst. No post-operative complication was observed. The endoscopic transventricular approach is safe and most suitable in terms of minimum invasiveness for the intrasuprasellar cystic lesion. We consider that neuroendoscopic transventricular approach will become the common surgical method of choice for treating a suprasellar cystic mass lesion.

Analysis of ischemic brain damage in cases of acute subdural hematomas

BACKGROUND

Ischemic damage of the brain is one of the most important factors for the sequelae of acute subdural hematomas (ASDHs). However, ischemic damage is infrequently addressed in a systematic manner in the clinical setting.

METHODS

The analysis of ischemic brain damage was performed based on serial computed tomography (CT) scans in 80 patients with traumatic ASDHs. Single photon emission computed tomography (SPECT) for regional blood flow and/or magnetic resonance imaging (MRI) were also performed.

RESULTS

Follow-up CT scans showed ischemic brain damage in 19 patients and no significant damage in 35 patients. The remaining 26 patients progressively deteriorated to the point of brain death. The ischemic brain damage was seen most frequently in the territory of the anterior cerebral artery (13 cases), followed by the territory of the posterior cerebral artery (12 cases). The ischemic damages in the pallidum, the hypothalamus and the thalamus were demonstrated in 4, 8, and 4 cases, respectively. The ischemic damage in the underlying brain that was probably because of the direct compression of the hematoma was seen in only two cases.

CONCLUSIONS

Most of the ischemic brain damage noted in this study was because of arterial compression secondary to the brain shift and brain herniation, rather than the direct effect of the hematoma upon the underlying brain. Ischemic brain damage adversely affects outcome morbidity, and the difficulty in preventing ischemic damage in cases with marked brain shift leads to poor outcome in patients with ASDHs.

Genetic alterations of human brain tumors as molecular prognostic factors

Despite a number of basic and clinical studies, it is still very difficult to improve the prognosis of patients with high-grade astrocytoma. However, the recent success of procarbazine, N-(2-chloroethyl)-N'-cyclohexyl-N-nitrosourea and vincristine (PCV) chemotherapy for oligodendrogliomas that have lost chromosomes 1p and 19q has encouraged the authors to evaluate the biological behavior of brain tumors by means of genetic analysis. Both the disorders of the p53/MDM2/p14(ARF) and the p16(INK4a)/RB signaling pathways have been found to play an essential role in tumorigenesis of various brain tumors. Herein, the authors summarize the genetic alterations of brain tumors by mainly focusing on two pathways that appear to affect significantly the patient prognosis.

Histologically classified venous angiomas of the brain: a controversy

The term "venous angioma" (VA) usually refers to a developmental venous anomaly (DVA). However, a group of vascular malformations called VAs shows no venous abnormalities on angiography. The clinical and histological features of histologically classified VAs were studied in eight patients who presented with hemorrhage or seizures to reevaluate these venous anomalies. Angiography showed no venous abnormalities in six patients. Histological study included immunostaining for smooth muscle actin and glial fibrillary acidic protein. Surgical specimens of 10 cases of cavernous angiomas, 10 cases of arteriovenous malformations, and two cases of capillary telangiectasias were studied to compare these types of VAs. Angiographically occult VAs were surgically removed safely, whereas removal of DVAs was complicated by brain swelling and hemorrhagic infarction of the brain. Histological examination found angiographically occult VAs contained malformed and compactly arranged vessels with partly degenerated walls, whereas DVAs had dilated thin-walled vessels that were diffusely distributed in the normal white matter. This study of our cases and a review of the reported cases of VAs suggests that two different clinical and pathological entities are commonly categorized as "VA," angiographically occult VAs and DVAs. These two entities should be carefully distinguished.

Ventricular diverticula in obstructive hydrocephalus secondary to tumor growth

OBJECTIVE

The association of ventricular diverticula with intra- and paraventricular tumors causing obstructive hydrocephalus has rarely been reported.

METHODS

Records and imaging findings for 57 patients with obstructive hydrocephalus caused by tumors who were treated at our institution were reviewed for the presence of ventricular diverticula. For the anatomic study of ventricular diverticula, data were collected from five cadaveric heads.

RESULTS

Ventricular diverticula were identified on magnetic resonance imaging scans in five cases. Diverticula were similarly located in the quadrigeminal cistern but originated from the medial wall of the atrium of the lateral ventricle in three cases and from the superior portion of the fourth ventricle in two cases. Regression of diverticula occurred in all cases after either insertion of a shunt or removal of the obstructing tumor. The cadaveric study suggested that the choroidal fissure and the rostral portion of the superior medullary velum might be the origins of diverticula from the atrium and from the superior portion of the fourth ventricle, respectively.

CONCLUSION

Ventricular diverticula should be distinguished from other cystic lesions in the quadrigeminal region. Detection of an ostium of a diverticulum or communication between the cyst and the ventricular system is important for diagnosis.

Biologic characterization of a secondary glioblastoma with extracranial progression and systemic metastasis

Glioblastomas rarely metastasize outside the CNS. We biologically characterized a case of secondary glioblastoma associated with extracranial progression and distant metastasis. A 42-year-old male patient was subjected to craniotomy for a left temporal tumor (astrocytoma grade II) and subsequently underwent another 3 craniotomies due to tumor recurrences. At the third craniotomy, extracranial progression was noted, and the tumor was classified as a glioblastoma. In order to pinpoint the genes expressed differentially in the intracranial primary tumor and the metastatic tumors, we used cDNA microarray. The patterns of gene expression in these 2 samples were highly similar, suggesting that the mechanism of metastasis was direct infiltration of tumor cells into extracranial blood vessels. Insulin-like growth factor binding protein-2 was overexpressed in both primary and metastatic tumors. Immunohistochemical studies of DNA-dependent protein kinase, which participates in the repair of DNA, was strongly positive in the samples obtained at the first and second operations, but the positive rates were markedly reduced in the specimens obtained at the third and fourth operations. These results suggest that insulin-like growth factor binding protein-2 and deficiency of DNA-dependent protein kinase proteins promoted tumor progression in the present case.