Histopathology, pathogenesis and molecular genetics in primary central nervous system lymphomas

Recent increases in the incidence of primary central nervous system lymphoma (PCNSL), a rare non-Hodgkin's lymphoma arising in the brain, have been noted in both immunodeficient and immunocompetent patients. Compared with lymphomas originating outside the central nervous system, the biology of PCNSL at the molecular or cytogenetic level has not been well characterized, yet it is important to thoroughly understand the etiology of this rare malignant lymphoma if effective therapies are to be developed. This review will focus on the epidemiology, clinical aspects, histopathology, pathogenesis, and molecular genetics of this aggressive, extranodal lymphoma in immunocompetent patients.     

Highly potent PDE4 inhibitors with therapeutic potential

Based on the hypothesis that the dose-limiting side effects of PDE4 inhibitors could be mediated via the central nervous system (CNS), design and synthesis of a hydrophilic analogue is considered to be one approach to improving the side-effect profile of Ariflo 1. Water-soluble piperidine derivatives were found to possess therapeutic potential.     

MexAB-OprM specific efflux pump inhibitors in Pseudomonas aeruginosa. Part 3: Optimization of potency in the pyridopyrimidine series through the application of a pharmacophore model

The addition of substituents to the pyridopyrimidine scaffold of MexAB-OprM specific efflux pump inhibitors was explored. As predicted by a pharmacophore model, the incorporation substituents at the 2-position improved potency. Piperidines were found to be optimal, and further introduction of polar groups without compromising the activity was shown to be feasible. Careful positioning of the essential acidic moiety of the pharmacophore relative to the scaffold led to the discovery of vinyl tetrazoles with still greater potency.     

Gender difference in QTc prolongation of people with mental disorders

BACKGROUND: We examined gender difference in QTc interval distribution and its related factors in people with mental disorders. METHODS: We retrospectively reviewed medical charts of patients discharged from a university psychiatric unit between November 1997 and December 2000. Subjects were 328 patients (145 males and 183 females) taking psychotropics at their admission. We examined patient characteristics, medical history, diagnosis, and medication before admission. RESULTS: Mean QTc interval was 0.408 (SD = 0.036). QTc intervals in females were significantly longer than those in males. QTc of females without comorbidity was significantly longer than that of males. CONCLUSION: The influence of gender difference on QTc prolongation in people with mental disorders merits further research.     

Highly potent PDE4 inhibitors with therapeutic potential

The hypothesis that the dose-limiting side effects of PDE4 inhibitors could be mediated via the central nervous system prompted us to design and synthesize a hydrophilic piperidine analog to improve the side effect profile of Ariflo 1, which is an orally active second-generation PDE4 inhibitor. During evaluation of various water-soluble piperidine analogs, 2a-b, 11b-14b, and 17a showed therapeutic potential in cross-species comparison studies. The following three findings were obtained: (1) The hydroxamic acid group, a well known metal chelator, caused a marked increase of inhibitory activity. (2) Water-soluble piperidine analogs lacked the configurational isomerism of Ariflo 1 without loss of inhibitory activity. (3) Replacement of the 4-methoxy residue with a difluoromethoxy residue led to an increase of in vivo potency. Structure-activity relationships are presented. Single-dose rat pharmacokinetic data for 11b, 12b, and 17a are also presented.     

Effect of centrifuge-induced artificial gravity and ergometric exercise on cardiovascular deconditioning, myatrophy, and osteoporosis induced by a -6 degrees head-down bedrest

We have reported that centrifuge-induced artificial gravity with ergometric exercise could reduce developing cardiovascular deconditioning in humans. In the present study, we examined this load could prevent the myatrophy and osteoporosis induced by head-down bedrest for 20 days. Subjects were ten healthy male volunteers with informed consent. They were requested to lie down at -6 degrees for 20 days, and evaluation for cardiovascular deconditioning, myatrophy, and osteoporosis. As the result, high G-load with low intensity exercise suppressed the orthostatic intolerance and increase in serum osteoporotic marker, whereas low G-load with high intensity ergometric exercise maintained the maximal oxygen intake, heart dimension, and prevented myatrophy. The combination of high/low G-load with low/high intensity exercise will determine the optimal protocol for prevention of cardiovascular deconditioning, myatrophy, and osteoporosis.     

A rapid biosensor chip assay for measuring of telomerase activity using surface plasmon resonance

Considerable interest has been focused on telomerase because of its potential use in assays for cancer diagnosis, and for anti-telomerase drugs as a strategy for cancer chemotherapy. A number of assays based on the polymerase chain reaction (PCR) have been developed for evaluation of telomerase activity. To overcome the disadvantages of the conventional telomerase assay [telomeric repeat amplification protocol (TRAP)] related to PCR artifacts and troublesome post-PCR procedures, we have developed a telomeric repeat elongation (TRE) assay which directly measures telomerase activity as the telomeric elongation rate by biosensor technology using surface plasmon resonance (SPR). 5′-Biotinylated oligomers containing telomeric repeats were immobilized on streptavidin-pretreated dextran sensor surfaces in situ using the BIACORE apparatus. Subsequently, the oligomers associated with the telomerase extracts were elongated in the BIACORE apparatus. The rate of TRE was calculated by measuring the SPR signals. We examined elongation rates by the TRE assay in 18 cancer and three normal human fibroblast cell lines, and 12 human primary carcinomas and matching normal tissues. The elongation rates increased in a concentration- and time-dependent manner. Those of cancer cells were two to 10 times higher than fibroblast cell lines and normal tissues. Telomerase activities and its inhibitory effects of anti-telomerase agents as measured by both the TRE and TRAP assays showed a good correlation. Our assay allows precise quantitative comparison of a wide range of human cells from somatic cells to carcinoma cells. TRE assay is suitable for practical use in the assessment of telomerase activity in preclinical and clinical trials of telomerase-based therapies, because of its reproducibility, rapidity and simplicity.