Immunohistological profiling by B-cell differentiation status of primary central nervous system lymphoma treated by high-dose methotrexate chemotherapy.

Primary central nervous system lymphoma (PCNSL) remains a devastating disease with poor prognosis, despite the improvement offered by methotrexate (MTX)-based chemotherapy. Several studies have attempted to identify biomarkers predictive of prognosis, which are expected to be both clinically useful and biologically important for understanding PCNSL. The present study attempts to classify human immunodeficiency virus (HIV)-unrelated PCNSL patients treated with radiation combined with rapid high-dose MTX chemotherapy according to B-cell differentiation status, and retrospectively examines the prognostic impact. Initial response to MTX was a strong predictor of favorable prognosis in terms of both progression-free survival (PFS) and overall survival (OS). Thirteen out of 29 cases were CD10(-)/BCL-6(+)/MUM-1(+), being more frequent compared with systemic peripheral nodal lymphoma. Although post-germinal-center B-cell-originating PCNSLs (CD10(-)/BCL-6(-)/MUM-1(+)) showed a trend towards better response to MTX and progression-free survival than did germinal-center-related B-cell-originating PCNSLs (CD10(+) OR CD10(-)/BCL-6(+)/MUM-1(+)), the difference was only marginal (P = 0.04 Gehan-Breslow-Wilcoxon, P = 0.17 log-rank). Our results imply that different B-cell stages in PCNSL have significant relevance in terms of biological behavior. However, clinical use as a prognostic marker requires further investigation.

Diffusion tensor fiber tracking in patients with central post-stroke pain; correlation with efficacy of repetitive transcranial magnetic stimulation.

Central post-stroke pain (CPSP) is one of the most common types of intractable pain. We reported that repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex relieves pain for patients who were refractory to medical treatment. But the mechanism is unclear. In the present study, we investigated relations between the characteristics of CPSP and the results of fiber tracking, which is the only noninvasive method of evaluating the anatomical connectivity of white matter pathways. Fiber tracking of the corticospinal tract (CST) and thalamocortical tract (TCT) was investigated in 17 patients with CPSP. The stroke lesion was located in a supratentorial region in all cases (corona radiata, one case; thalamus, seven cases; putamen, nine cases). Relations between the delineation ratio (defined as the ratio of the cross section of the affected side to that of the unaffected side) of the CST and of the TCT, manual muscle test score, pain score, region of pain, and efficacy of rTMS were evaluated. Fiber tracking was successful in 13 patients with the stroke lesion involving the TCT. The rTMS-effective group had higher delineation ratio of the CST (p=0.02) and the TCT (p=0.005) than the rTMS-ineffective group. Previous studies suggested that an intact CST allows pain control but did not discuss the TCT. Our results suggest that the TCT also plays a role in pain reduction by rTMS of the primary motor cortex and that the efficacy of rTMS for patients with CPSP is predictable by fiber tracking.

Screening of ACE-inhibitory peptides from a random peptide-displayed phage library using ACE-coupled liposomes.

Angiotensin I converting enzyme (ACE)-inhibitory peptides were screened from a random peptide-displayed phage library using ACE-coupled liposomes. Among four kinds of inhibitory peptides selected by biopanning with two different elution strategies, a peptide (LSTLRSFCA) showed the highest inhibitory activity with an IC(50) value of 3microM. By measuring inhibitory activities of fragments of the peptide, it was found that the RSFCA region was a functional site to inhibit strongly the ACE catalytic activity, and particularly both Arg and Cys residues were essential for the strong inhibitory activity. The inhibitory activity of RRFCA was slightly increased, while that of the RSFRA, in which the Cys residue was replaced by Arg, was decreased to greater extent in comparison with the inhibitory activity of RSFCA. Taking into account the results obtained from the SPOT analysis, it was suggested that the Arg and Phe residues in RSFCA were important for a specific interaction with ACE, and the Cys residue inhibited the ACE activity. The cystein-based ACE-inhibitory peptides have not been isolated from processed food materials. These findings suggested that the biopanning method utilizing protein-coupled liposomes and random peptide libraries might have a possibility to screen new functional peptides that are not found in processed food materials.

Ganglioside GM3 inhibits proliferation and invasion of glioma.

GM3, the simplest ganglioside, modulates cell adhesion, proliferation and differentiation in the central nervous system and exogenously added GM3 regulates cell-cell and cell-extracellular matrix adhesion and induces apoptosis. To assess the anti-tumor action of exogenous GM3, we examined its effect on the proliferation and invasion of glioma cells. Its inhibitory effect on cell proliferation was demonstrated in vitro by 3-(4,5-dimethyl-2-thiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay and in vitro in rats with meningeal gliomatosis whose survival was significantly prolonged by the intrathecal injection of GM3. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay revealed that GM3 induced glioma cell apoptosis in vitro and in vitro. In rat brain slice cultures, GM3 suppressed the invasion of glioma cells; this effect manifested earlier than the inhibition of cell proliferation and before apoptosis induction. Our results suggest exogenous GM3 as a potential therapeutic agent in patients with glioma requiring adjuvant therapy.