Magnetic resonance vessel wall imaging predicts morphological deterioration in unruptured intracranial artery dissection.

OBJECTIVE: The mechanism involved in progression of unruptured intracranial artery dissection (IAD) is poorly understood. We investigated the relationship between contrast enhancement of dissecting lesions on magnetic resonance vessel wall imaging (MR-VWI) and unruptured IAD progression on the hypothesis that this finding might predict its instability. METHODS: A total of 49 unruptured IADs were investigated retrospectively. Three-dimensional T1-weighted fast spin-echo sequences were obtained before and after injection of contrast medium, and the dissecting lesion/pituitary stalk contrast enhancement ratio (CRstalk) was calculated. Unruptured IAD progression was defined as morphological deterioration; progressive dilatation or stenosis. The relations between unruptured IAD progression and potential risk factors were statistically investigated. RESULTS: Morphological deterioration was demonstrated in eleven of 49 unruptured IADs (22 %). The CRstalk value and male predominance was significantly higher in progressed IADs than stable ones (1.0 vs. 0.65; p = 0.0035, 82% vs 37%; p= 0.015, respectively). On stepwise multivariable logistic regression analysis, the CRstalk value was independently associated with unruptured IAD progression with odds ratio of 102.5 (95% CI, 2.59-4059, P=0.0013). The optimal cutoff value of CRstalk to estimate IADs with progression was 0.87 (sensitivity, 0.82; specificity, 0.74). Multimodalic images showed contrast enhancement on VWI corresponded to residual stagnant flow in dissecting lesions. CONCLUSIONS: Quantitative analysis of contrast enhancement on VWI could predict instability of unruptured IADs. Contrast enhancement in dissecting lesions would be a clue to understand the mechanism of unruptured IAD progression.

Imaging evaluation of the cartilage in rheumatoid arthritis patients with an x-ray phase imaging apparatus based on Talbot-Lau interferometry.

X-ray Talbot-Lau interferometry is one of the x-ray phase imaging methods that has high sensitivity in depicting soft tissues. Unlike earlier x-ray phase imaging methods that required particular types of x-ray sources, such as a synchrotron or a micro-focus x-ray tube, x-ray Talbot-Lau interferometry enables to perform clinical x-ray phase imaging using a conventional x-ray source with a relatively compact configuration. We developed an apparatus to depict cartilage in the metacarpophalangeal joints of the hands. In addition, we examined the apparatus performance by applying it to healthy volunteers and patients with rheumatoid arthritis (RA). Cartilage deformation, which is thought to be a precursor of destruction of the joints, was successfully depicted by the apparatus, suggesting a potential early diagnosis of RA.

MRI findings in patients with central neurocytomas with special reference to differential diagnosis from other ventricular tumours near the foramen of Monro.

We retrospectively evaluated 12 patients with histologically verified central neurocytoma (CN) to identify the MRI characteristics associated with this tumour. All tumours had heterogeneous signal intensity in their solid components and seven had a "soap bubble" or spongy appearance. Spicules were identified at the tumour periphery interfacing with the lateral ventricular walls. These spicules were formed by walls of multiple cysts of medium size. Undulation of the lateral ventricular wall attached to the tumour capsule was seen in nine patients. These spicules and undulations resulted in a "scalloping" appearance. In a diagnostic experiment to test the differential diagnosis of CN from other neoplasms near the foramen of Monro, the identification of scalloping made a greater contribution to the specificity and accuracy of the diagnosis than the soap bubble appearance. Thus, recognition of multiple cystic interfaces between the solid part of the tumour and the lateral ventricular wall on MRI may contribute to a correct preoperative diagnosis of CN.

Simple form of multimode laser diode rate equations incorporating the band filling effect.

To derive a simple form of the multimode laser diode rate equations incorporating the band filling effect, the laser diode gain in the direct bandgap model is introduced into the conventional multimode laser diode rate equations. By numerically examining each modal gain under the gain-switching condition, it is found that both the differential gain coefficient and the carrier density at transparency show an approximately linear dependency on the oscillation frequency. As a result, it is possible to derive a simple form of the multimode laser diode rate equations with linearized gain, which can be used to simulate the behaviors of a gain-switched laser diode characterized by the band filling effect, in both the multimode and single-mode oscillation cases.

Primary diffuse leptomeningeal gliosarcomatosis.

We report a 48-year-old woman with primary diffuse leptomeningeal gliomatosis (PDLG) histologically diagnosed as gliosarcoma. She was admitted complaining of headache, numbness of the right arm, double vision, and visual field defects. Computerized tomography (CT) scans showed ventricular dilatation consistent with communicating hydrocephalus. Magnetic resonance imaging (MRI) revealed diffuse meningeal thickening and gadolinium enhancement without a definite intraparenchymal lesion. Whole-spine MRI demonstrated across-the-board dural thickening and gadolinium enhancement. Cytological examination showed atypical anaplastic cells. As no diagnosis could be made she underwent biopsy of the leptomeninges. Histological examination of the specimen returned a diagnosis of gliosarcoma. Despite chemotherapy and radiotherapy she died 11 months after admission. Autopsy findings included gliosarcoma in the leptomeninges and spinal cord without an underlying parenchymal tumor. To our knowledge, this is the first report of primary diffuse leptomeningeal gliosarcomatosis.

Retinoblastoma protein prevents staurosporine-induced cell death in a retinoblastoma-defective human glioma cell line.

OBJECTIVE: To investigate the mechanism of staurosporine-induced glioma cell death and cell cycle arrest using adenovirus-mediated gene transfection, as well as the function of retinoblastoma (Rb) and genetic instability induced by staurosporine. METHODS: Cell cycle regulation, cell death and nuclear abnormalities induced by staurosporine were examined using an adenovirus vector expressing Rb, p16 or p21 genes in human glioma cell lines. RESULTS: The Rb-defective SF-539 cell line was resistant to staurosporine compared with cell lines expressing intact Rb. SF-539 glioma cells exposed to staurosporine became multinucleated and then died. Multinucleation was prevented in SF-539 cells transfected with the Rb gene, thus decreasing the death rate of these cells. CONCLUSIONS: These results imply that enforced Rb expression protects cells from genomic instability induced by staurosporine regardless of its upstream molecular effects.

Detection and differentiation of lactate and lipids by single-voxel proton MR spectroscopy.

The signals of lactate and lipids partially overlap in single-voxel proton MR spectroscopy (1HMRS), sometimes making them difficult to differentiate in clinical settings. Our aim in this study was to identify lactate and lipids by varying the echo time (TE). We expect that the accurate detection of lactate and lipids will have high diagnostic value in the diagnosis of brain tumors. Following our protocol, we obtained meaningful 1HMRS spectra from 213 patients, including 163 patients with brain tumors, between August 1999 and February 2004. 1HMRS was performed with a TE of 144 ms followed by a TE of 30 ms and/or a TE of 288 ms, if necessary. For the 213 patients, lactate level was "negative" in 47 patients, "positive" in 131 patients, and "strongly positive" in 35 patients. The lipid level was "negative" in 90 patients, "positive" in 56 patients, and "strongly positive" in 67 patients. Based on logistic discriminant analyses of neuro-epithelial tumor WHO grade and lactate and lipid levels, lactate and lipid levels were significant between WHO grades 2 and 3 (P=0.0239) and between grades 3 and 4 (P=0.0347). Lipids are a more significant factor for the discrimination between WHO grades 2 and 3 (P=0.0073) and between grades 3 and 4 (P=0.0048). With our method of varying the TE, it is possible accurately and efficiently to detect lactate and lipids in the brain. We found a significant correlation between lactate and lipid expression and WHO grade of neuro-epithelial tumors.

Apparent diffusion coefficient of human brain tumors at MR imaging.

PURPOSE: To determine if apparent diffusion coefficient (ADC) can be used to differentiate brain tumors at magnetic resonance (MR) imaging. MATERIALS AND METHODS: Institutional review board approval or informed patient consent was not required. MR images were reviewed retrospectively in 275 patients with brain tumors: 147 males and 128 females 1-81 years old, treated between September 1997 and July 2003. Regions of interest were placed manually in tumor regions on MR images, and ADC was calculated with a five-point regression method at b values of 0, 250, 500, 750, and 1000 sec/mm2. ADC values were average values in tumor. All brain tumor subgroups were analyzed. Logistic discriminant analysis was performed by using ADC, age, and patient sex as independent variables to discriminate among tumor groups. RESULTS: A significant negative correlation existed between ADC and astrocytic tumors of World Health Organization grades 2-4 (grade 2 vs grades 3 and 4, accuracy of 91.3% [P < .01]; grade 3 vs 4, accuracy of 82.4% [P < .01]). ADC of dysembryoplastic neuroepithelial tumors (DNTs) was higher than that of astrocytic grade 2 tumors (accuracy, 100%) and other glioneuronal tumors. ADC of malignant lymphomas was lower than that of glioblastomas and metastatic tumors (accuracy, 83.6%; P < .01). ADC of primitive neuroectodermal tumors (PNETs) was lower than that of ependymomas (accuracy, 100%). ADC of meningiomas was lower than that of schwannomas (accuracy, 92.4%; P < .01). ADC of craniopharyngiomas was higher than that of pituitary adenomas (accuracy, 85.2%; P < .05). ADC of epidermoid tumors was lower than that of chordomas (accuracy, 100%). In meningiomas, ADC was not indicative of malignancy grade or histologic subtype. CONCLUSION: ADC is useful for differentiation of some human brain tumors, particularly DNT, malignant lymphomas versus glioblastomas and metastatic tumors, and ependymomas versus PNETs.

Relationship between intratumoral hemorrhage and overexpression of vascular endothelial growth factor (VEGF) in pituitary adenoma.

The authors investigated the relationship between hemorrhage and the expression of vascular endothelial growth factor (VEGF) in pituitary adenomas. The subjects were 39 patients with pituitary adenomas. Surgically obtained tumor tissue was immunohistochemically stained using antibodies against VEGF, CD-34, Ki-67, and anterior pituitary hormones. The expression of VEGF was graded as 0, 1+, and 2+. The relationship between intratumoral hemorrhage and factors such as tumor size, Ki-67 labeling indices, number of CD-34 positive vessels, and VEGF expression was examined by multivariate analysis. High-grade VEGF expression was the sole independent factor correlated with intratumoral hemorrhage. The number of CD-34 positive vessels had no effect on the incidence of hemorrhage in patients with pituitary adenomas. In conclusion, a positive relationship between VEGF expression and hemorrhage in pituitary adenoma was observed. The patho-mechanical significance of this correlation is under investigation.

Expression and epitope analysis of the major allergenic protein Fag e 1 from buckwheat.

Seeds of common buckwheat (Fagopyrum esculentum) contain valuable nutritive substances but also allergenic proteins that cause hypersensitive reactions. Thus, the development of hypoallergenic buckwheat would make this important pseudo-cereal available to allergic people. A major allergenic protein of buckwheat is Fag e 1. We isolated the respective cDNA, coding for a 22 kDa protein, from a recently developed autogamous strain of common buckwheat and confirmed its immunoglobulin E (IgE)-binding activity using recombinant Fag e 1 and sera of allergic patients. The derived amino acid sequence from Fag e 1 cDNA was used to synthesize an overlapping peptide library on nitrocellulose membranes for the determination of the Fag e 1 epitopes. We identified eight epitopes and the critical amino acids for IgE-binding within the epitopes. This epitope analysis of a major allergenic protein of buckwheat should help therapeutic efforts and aid in the development of hypoallergenic buckwheat.

De novo distal posterior cerebral artery aneurysm.

BACKGROUND: De novo aneurysms in the posterior circulation are very rare. The authors describe a first case of ruptured de novo posterior cerebral artery (PCA) aneurysm in the P3 portion. CASE DESCRIPTION: A 52-year-old woman with ruptured de novo P3 aneurysm was treated by early endovascular obliteration using Guglielmi Detachable Coils (GDC). To prevent vasospasm, she received postoperative treatment with a hypertensive hypervolemia dilution and a calcium antagonist. She was discharged without neurologic deficits. CONCLUSIONS: Aneuryms arising from peripheral segment of PCA are rare, and delayed surgical clipping has been recommended for these lesions. This is the first report of a de novo P3 ruptured aneurysm treated by endovascular embolization using GDC in the acute stage of subarachnoid hemorrhage. The characteristics of de novo posterior circulation aneurysms and the strategy for the distal PCA aneurysms are discussed.

Staurosporine-induced apoptosis is independent of p16 and p21 and achieved via arrest at G2/M and at G1 in U251MG human glioma cell line.

OBJECTIVE: The mechanisms involved in the cell cycle and cell death remain unresolved despite much investigation. Staurosporine induces cell death and G1 or G2/M arrest in a dose-dependent manner, but the mechanisms remain unknown. METHODS: In the present study an adenovirus vector expressing p16 or p21 genes in human glioma cell lines was used to examine cell cycle regulation and cell death induced by staurosporine. RESULTS: A low concentration (/=30 n M) induced G2/M arrest and finally induced apoptosis via a caspase-3-activated pathway from both the G2/M and G1 phases. However, pRb was dephosphorylated and cdc2 was inhibited at both the low and the high concentrations of staurosporine, indicating that the mechanisms of cell cycle regulation are not simply p53-Rb- or cdc2-dependent pathways. CONCLUSIONS: Forced G1 arrest by transfection with p16 or p21 genes did not alter the rate of staurosporine-induced cell death. This implies that an unknown pathway of apoptosis occurs from the G1 phase.

Interhemispheric arachnoid cyst in the elderly: case report and review of the literature.

BACKGROUND: Preoperative differential diagnosis of interhemispheric cysts is sometimes difficult. CASE DESCRIPTION: We recently experienced a case of symptomatic interhemispheric arachnoid cyst in a 62-year-old woman. We reviewed interhemispheric arachnoid cysts in the elderly and the management of symptomatic interhemispheric arachnoid cysts in elderly patients. Symptomatic interhemispheric arachnoid cysts in the elderly are predominantly located on the right side, have a long history of progressive symptomology, occur predominantly in females, and have no communication with the subarachnoid space. Interhemispheric arachnoid cysts are usually not associated with agenesis of the corpus callosum in elderly patients, whereas interhemispheric nonarachnoid cysts are usually associated with agenesis of the corpus callosum, which will be clearly demonstrated on magnetic resonance imaging. CONCLUSIONS: It is highly possible that an interhemispheric cyst without agenesis of the corpus callosum in an adult is an arachnoid cyst.

Expression of survivin in astrocytic tumors: correlation with malignant grade and prognosis.

BACKGROUND: Astrocytic tumors are the most common tumors of the central nervous system. The mechanisms of genetic change of astrocytic tumors have not been understood completely. Recently, survivin has been identified as a member of the inhibitor-of-apoptosis family. Survivin expression is considered an important prognostic factor of many tumors. METHODS: The authors investigated 43 astrocytic tumors (8 diffuse astrocytomas; 15 anaplastic astrocytomas; 20 glioblastomas). The authors examined survivin mRNA expression in tumor specimens by reverse transcriptase-polymerase chain reaction amplification. The authors analyzed the relationship between survivin expression and other molecular changes commonly found in astrocytic tumors [p53 alteration, overexpression of epidermal growth factor receptor (EGFR), and bcl-2 expression]. RESULTS: Thirty-four of 43 (79.1%) astrocytic tumors expressed survivin. The distributions included 3 of 8 (37.5%) diffuse astrocytomas, 13 of 15 (86.7%) anaplastic astrocytomas, and 18 of 20 (90.0%) glioblastomas. Expression of survivin (P = 0.0057) and EGFR (P = 0.0112) was significantly associated with malignant grade of astrocytic tumors, but expression of p53 (P = 0.1893) and bcl-2 (P = 0.2552) was not. Furthermore, patients with survivin-positive astrocytic tumors had significantly shorter overall survival times compared with patients who had survivin-negative tumors (P = 0.0271). CONCLUSIONS: Survivin expression in astrocytic tumors varies with histologic malignancy and may play an important role in the oncogenesis and progression of astrocytic tumors. These data suggest that survivin has great potential as a therapeutic target in astrocytic tumors.

Changes in the epithelium of Rathke cleft cyst associated with inflammation.

OBJECT: Rathke cleft cysts (RCCs) are composed of tall, well-differentiated, ciliated columnar epithelia. Their structures are altered by hyperplasia or squamous metaplasia, but their cause remains unknown. METHODS: The authors studied pathological findings and anterior pituitary function in 20 patients harboring RCCs. They classified RCC epithelium as either single (a single ciliated columnar cell lining or a flattened cuboidal cell lining) or stratified (a stratified ciliated columnar cell lining, basal cell hyperplasia, columnar cell hyperplasia, or squamous metaplasia). Inflammation was classified as acute, subacute, chronic, or end stage. The epithelial cell lining was observed in 13 specimens obtained during surgery (six specimens contained single and seven contained stratified epithelia). Inflammation had penetrated the cyst epithelium or subjacent stroma in 10 patients, and the stage of inflammation correlated well with the type of epithelia group: early stages of inflammation in the single epithelium group and chronic or end-stage inflammation in the stratified epithelia (p = 0.0027). The adenohypophysis was identified in 21 surgical specimens. Postoperatively, growth hormone (p = 0.019), cortisol (p = 0.027), and thyroid-stimulating hormone (p = 0.039) responses significantly worsened as the inflammation progressed. The presence of diabetes insipidus correlated well with advanced stages of neurohypophysitis (p = 0.025). CONCLUSIONS: Epithelial stratification in the RCC is caused by inflammation that may extend into the adjacent adenohypophysis or neurohypophysis and overwhelm the hypophysis, resulting in panhypopituitarism. Transsphenoidal excision may represent the best choice for treatment, at least for cases of RCC in which there is partial impairment of hypophysial function.