Development of a method of evaluating PuO2 particle diameters using an alpha-particle imaging detector.

It is very important to evaluate the diameters (activity median aerodynamic diameter) of plutonium dioxide (PuO2) particles for internal exposure dose evaluation. In this study, a method of evaluating PuO2 particle diameters using an alpha-particle imaging detector was developed. PuO2 particles with different diameters were modeled by Monte Carlo simulation, and the change in the shape of the energy spectrum for each particle diameter was evaluated. Two different patterns were modeled, namely, the case of 239PuO2 and the case of PuO2 (including isotopic composition of Pu). Multiple regression analysis was performed to determine the PuO2 particle diameter from the obtained parameters. The simulated diameters and the diameters obtained with the regression model were in good agreement. The advantage of using the alpha-particle imaging detector is to measure the alpha energy spectrum for individual particle, and this allows accurate measurement of particle diameter distribution.

Glutathione-triggered activation of the model of pro-oligonucleotide with benzyl protecting groups at the internucleotide linkage.

We have examined substituted benzyl protecting groups for the phosphodiester in oligodeoxyribonucleotides. Stability of the protecting groups in buffer and rates of deprotection by glutathione (GSH) were strongly influenced by benzyl ring substituents.

Enhancement of the 1-Octanol/Water Partition Coefficient of the Anti-Inflammatory Indomethacin in the Presence of Lidocaine and Other Local Anesthetics.

Side effects and excessive potentiation of drug efficacy caused by polypharmacy are becoming important social issues. The apparent partition coefficient of indomethacin (log P'IND) increases in the presence of lidocaine, and this is used as a physicochemical model for investigating polypharmacy. We examined the changes in log P'IND caused by clinically used local anesthetics-lidocaine, tetracaine, mepivacaine, bupivacaine, and dibucaine-and by structurally similar basic drugs-procainamide, imipramine, and diltiazem. The quantitative structure-activity relationship study of log P'IND showed that the partition coefficient values (log PLA) and the structural entropic terms (ΔSobs, log f) of the additives affect log P'IND. These results indicate that the local anesthetics and structurally similar drugs function as phase-transfer catalysts, increasing the membrane permeability of indomethacin via heterogeneous intermolecular association. Therefore, we expect that the potency of indomethacin, an acidic nonsteroidal anti-inflammatory drug, will be increased by concurrent administration of the other drugs.

Development of a photolabile protecting group for phosphodiesters in oligonucleotides.

A photolabile protecting group, consisting of an o-nitrobenzyl group and a 3-(2'-hydroxy-3',6'-dimethylphenyl)-2,2-dimethylpropyl moiety, was developed for phosphodiesters in oligodeoxyribonucleotides. Deprotection was triggered by photoirradiation and subsequent spontaneous cyclization to release the naked oligonucleotide.

Simultaneous right and left coronary occlusion caused by an extensive dissection to the coronary sinus of Valsalva during percutaneous intervention in right coronary artery.

We report a case of simultaneous right and left coronary occlusion during percutaneous coronary intervention in the right coronary artery. An aortocoronary dissection induced by the forceful manipulation extended from the right to left sinus of Valsalva and occluded the ostia of both coronary arteries. The patient suffered cardiogenic shock and ventricular fibrillation. However, after successful rapid stenting to right and left coronary arteries, safe discharge was possible.

Increased serum thymidine kinase activity in acute sarcoidosis.

This is the first case report of acute sarcoidosis with increased serum thymidine kinase (TK) activity. A 43-year-old male presented fever, swelling of parotid glands, lymphadenopathy, and peripheral neuropathy. Sarcoidosis was pathologically diagnosed by lung and parotid gland biopsy. His serum TK, which was increased to 11.2 U/l at diagnosis (normal <5 U/l), normalized after glucocorticoid therapy. Serum TK has been considered as a good marker of the proliferative activity of various types of neoplasms. Its rise in sarcoidosis has, however, not been described. Because acute sarcoidosis sometimes resembles malignant lymphoma, the possible rise of serum TK in sarcoidosis may be worthy of note.