Yuichi Ito

Disposition of TF-PEG-Liposome-BSH in tumor-bearing mice

BNCT requires high concentration and selective delivery of (10)B to the tumor cell. To improve the drug delivery in BNCT, we conducted a study by devising TPLB. We administrated three types of boron delivery systems: BSH, PLB and TPLB, to Oral SCC bearing mice. Results confirmed that (10)B concentration is higher in the TPLB group than in the BSH group and that TPLB is significantly effective as boron delivery system.

Rapid and Easy Histological Evaluation of Alveolar Human Bone Quality at Dental Implant Sites Using a Nondecalcified Frozen Cryofilm Section Technique: A Technical Report.

Introduction:The evaluation of bone quality at the site of the alveolar bone for a dental implant is very important. This study presents an easy technique for direct evaluation of alveolar bone quality using nondecalcified cryofilm frozen sections on human alveolar bone core samples. Materials and Methods:Core samples harvested from alveolar bone were immediately frozen in cooled hexanen and slowly cut using a disposable tungsten carbide blade; the sliced sections were collected with adhesive cryofilms. Staining was performed using von toluidine blue and von Kossa for microscopic observations. Results:All core samples clearly showed bone structure components of cortical bone, trabecular bone, bone marrow, blood vessels, and bone-related cells. Conclusion:These results suggest the efficacy of a nondecalcified cryofilm frozen section technique for histological observation of surgical implant sites.

Comparison of the Biological Impacts of the Fluoride Compounds by Graphical Risk Visualization Map Technique

Various fluoride compounds are widely used in industry. The present risk assessment study was conducted using a series of inorganic binary fluorides of the type XFn, where Xn = Na+, K+, Li+, Mg2+, Ca2+, Sr2+, Ba2+, Al3+, Nd3+, La3+, Ce3+, Sm3+, Gd3+, Y3+, Yb2+, and Zn2+. The aqueous solutions of these salts were orally administrated to 16 experimental groups (one for each of the salts tested). The levels of fluoride, N-acetyl-β-d-glucosaminidase in cumulative 24-h urine samples and creatinine clearance were measured to assess possible acute renal damages. The levels of fluoride, alanine aminotransferase, and aspartate aminotransferase were also determined in serum samples to assess possible acute hepatic damages. The results reveal that sodium fluoride (NaF), potassium fluoride (KF), and zinc fluoride tetrahydrate (ZnF2.4H2O) can carry the fluoride ion into the bloodstream and that it is excreted via urine more readily than the other compounds tested. These fluorides were assigned the highest risk impact factor. Most of the rare earth fluorides are insoluble in water while those groups 2 and 13 of the periodic table are slightly soluble, so that they do not have a significant negative risk. These findings suggest that the biological impact of fluoride depends on the accompanying counter ion and its solubility. The risk map obtained in the present study shows that the graphical visualization map technique employed is a valuable new tool to assess the toxicological risk of chemical compounds.