White matter lesions in the brain with frontotemporal lobar degeneration with motor neuron disease: TDP-43-immunopositive inclusions co-localize with p62, but not ubiquitin

Recently, TDP-43 was established as a major component of the ubiquitinated inclusions found in both amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with motor neuron disease (FTLD-MND). However, differences in the underlying pathogenesis between ALS and FTLD-MND remain yet to be elucidated. Originally, TDP-43-immunopositive inclusions were found in neuronal cells and reported to be ubiquitinated. This study shows that TDP-43-positive inclusions were distributed throughout the subcortical white matter except for the occipital lobe in the FTLD-MND brain, but not in the ALS brain. TDP-43-positive inclusions were also prominent features of pathologically proven FTLD-MND cases (p-FTLD-MND) without history of apparent clinical cognitive decline. A substantial fraction of these inclusions was also p62-immunoreactive, and another noteworthy feature was that those inclusions did not stain positively for ubiquitin. Significant correlations between immunoreactivity for TDP-43 and p62 were observed, particularly in p-FTLD-MND (Pearson correlation coefficient, 0.976). Furthermore, TDP-43 extracted from white matter appeared to be uncleaved. These results indicate that pathological changes might take place within the white matter also in the brain with FTLD-MND, but in a different manner than within the gray matter.     

Gamma band synchronization and the formation of representations in visual word processing: evidence from repetition and homophone priming

The formation of an object's cortical representation seems to rely on synchronized neuronal activity within the gamma band frequency range (gamma band activity [GBA]). In this study, we investigated whether electroencephalogram (EEG) GBA, and its phase synchronization between electrodes, is necessary for the formation of nonobject higher-order cognitive representations, using both repetition and homophone priming tasks. In a repetition priming task, the formation of orthographic, phonological, and semantic representations is promoted by a prime word, whereas in the homophone priming task, the formation of only phonological representations is promoted. In the present study, the lexical processing of a target word induced GBA. In the repetition priming task, induced GBA and phase synchronization were decreased by presentation of the prime word (i.e., a repetition suppression effect) within both 200-300 msec and 400-500 msec time windows. In the homophone priming task, the repetition suppression effect was observed only within the 400-500 msec time window. The fact that repetition suppression effects were found in both priming tasks indicates that GBA and phase synchronization are necessary for the formation of phonological and semantic representations of a word. These results also suggest that formation of orthographic and higher-order cognitive representations occurred over different time courses.     

Meningioma associated with Werner syndrome--case report--

A 53-year-old man presented with a rare meningioma associated with Werner syndrome. Screening brain magnetic resonance (MR) imaging with gadolinium had detected multiple homogeneously enhanced tumors in the right convexity and in the anterior and posterior thirds of the falx cerebri after surgery for osteosarcoma in his right leg at age 52 years. Ten months later, the right convexity tumor was removed because follow-up MR imaging detected tumor growth. The histological diagnosis was transitional meningioma. The postoperative clinical course was good and the patient remains healthy. Review of the literature found meningiomas associated with Werner syndrome occur about two times more frequently in men than in women, and typically in the fourth decade. Most meningiomas associated with Werner syndrome are benign, but are sometimes complicated with extracranial tumors such as sarcoma, thyroid carcinoma, and others. Patients with meningioma associated with Werner syndrome should be carefully followed up to detect the occurrence of other extracranial tumors such as sarcoma by brain MR imaging, echography, or body computed tomography.     

Stem cells for kidney repair: useful tool for acute renal failure?

Several cell types isolated from adult tissues have been reported to differentiate into mature kidney cells that may participate in renal repair after systemic administration. Chen et al. report that local mesenchymal stem cells derived from adult mouse kidneys are another source of cells with similar properties. Although these cells have the potential to differentiate into endothelial-lineage cell types, their therapeutic benefit to the ischemic kidney is mainly via the production of renoprotective factors.     

Diesel exhaust particles disturb gene expression in mouse testis

Inhalation of diesel exhaust particles (DEP) has been found to reduce sperm production. There is a possibility that DEP exposure elicits changes in gene expression in testis. To identify the alteration of gene expression resulting from DEP exposure, we constructed subtracted cDNA libraries from mouse testis using the suppression subtractive hybridization method. We isolated 16 candidate clones whose expression levels changed after exposure. Some of these candidates were highly similar to known testis-specific genes. Some of the clones also seemed to correlate with spermatogenesis. Northern blot analysis revealed that DEP exposure changed the expression levels of several clones in a dose-dependent manner. For example, the expression of clone R8, which was very similar to human XRRA1, increased by 2.3-fold in testis after DEP exposure. On the other hand, the expressions of long-chain acyl-CoA synthetase 6 (Acsl6) and serine/threonine kinase 35 reduced by 0.3-fold. These results indicated that some constituents of DEP alter gene expression in the testis.     

Multi-detector-row CT angiography as a preoperative evaluation for spinal arteriovenous fistulae

The role of multi-detector-row computed tomographic angiography (MDCTA) in spinal vascular malformations has not yet been determined. We present a report on a short series of spinal arteriovenous fistulae (AVF) evaluated by MDCTA. With 4-row and 16-row MDCTA, three cases of spinal dural AVF and one case of perimedullary AVF were examined. Each case was also examined by magnetic resonance (MR) imaging and spinal catheter angiography. In two patients with spinal dural AVF, including one patient with angiographically occult AVF, MDCTA successfully located the site of the AVF in a multi-planar reformation image. MDCTA failed to locate the remaining case of spinal dural AVF, probably due to the small amount of shunting blood volume at the fistula. In a patient with perimedullary AVF, MDCTA visualized the broad range of the lesion, including the anterior spinal artery as a single feeder, the fistulous point, and the single perimedullary draining vein. In conclusion, although conventional spinal angiography might be still essential, MDCTA provides useful information for the surgeon in treatment of the spinal dural AVF. Further accumulation of clinical cases is required to determine the potential of MDCTA for perimedullary AVF. MDCTA should be considered as a choice of investigation in the evaluation of spinal AVFs.