Development of a magnetic sensing device for tooth displacement under orthodontic forces.

We have developed a system for measuring tooth displacement from orthodontic force. Eight small magnetic sensors and a magnet are combined to measure three-dimensional displacement. Sensors, arranged cubically in the three planes of space, are placed in the mouth and fixed to the posterior teeth by a splint. A magnet is placed in the center of the eight sensors and attached to a front tooth that is subjected to orthodontic force. Sensors detect the magnet's movement as target tooth displacement. The system was designed to achieve displacement resolution of 1 microm. The mean percentage of measurement errors was determined to be less than 1% in a 600-cubic-microm volume from calibration. The system was tested clinically on human teeth. Although the oral environment, with high temperature and humidity, was not agreeable with the sensors, this system was stable and accurate enough for quantitative measurement of tooth displacement. The advantage of this system is the ability to detect tooth trajectories by decomposing displacement into translation and rotation and to determine the position of the center of rotation from these parameters.

Structural considerations of NK109, an antitumor benzo[c]phenanthridine alkaloid.

The antitumor activities of a synthetic benzo[c]phenanthridine, NK109 (7-hydroxy-2, 3-methylenedioxy-5-methyl-8-methoxybenzo[c]phenanthridinium hydrogensulfate dihydrate), and of natural benzo[c]phenanthridines were tested in vitro and in vivo. NK109 (3) had the highest activity among them. NK109 is similar in structure to fagaronine and fagaridine; however, it has a phenolic-OH at C-7. NK109 exists as a resonance hybrid, the keto-amine and zwitterionic forms in neutral media. The resonance hybrid is cationic and has molecular planarity; these have been considered to be essential for the antitumor activity of the benzo[c]phenanthridinium salts. On the other hand, the structurally similar benzo[c]phenthridine alkaloids, chelerythrine and sanguinarine, exist as pseudobases under the same conditions. The latter do not exhibit antitumor activity in vivo, probably because they lose both the immonium region and molecular planarity. Thus, 3 may be considered to be novel category of benzo[c]phenanthridinium salt from the viewpoint of its structure under biological conditions.

Prostate-specific membrane antigen-derived primers in a nested reverse transcription polymerase chain reaction for detecting prostatic cancer cells.

The detection of prostate-specific membrane antigen (PSM) mRNA in the peripheral blood of prostate cancer patients by a nested reverse transcriptase-polymerase chain reaction (RT-PCR) assay is a useful and sensitive method for the identification of small foci of metastatic lesions. In this study, a nested RT-PCR assay was performed using the two different PSM-derived oligonucleotide primer sets reported by Israeli et al. and Loric et al. (termed PSM primers-1 and primers-2, respectively, in this report), and the differences in the specificity and sensitivity of these primer sets for detecting prostate cancer cells in the blood are discussed. The PCR assay using PSM primers-1 showed DNA bands for 4 of 7 cases of metastatic prostate cancer and amplified the untreated genomic DNA, while that using PSM primers-2 showed 6 bands without the amplification of the genomic DNA. In conclusion, PSM primers-2 is superior to PSM primers-1 for the detection of PSM mRNA in the peripheral blood of prostate cancer patients.

Physical mapping and identification of interspersed homologous sequences in the Trichoplusia ni granulosis virus genome.

A restriction fragment library representing 89.3% of the genome of Trichoplusia ni granulosis virus (TnGV) was constructed. The library consisted of 13 of the 16 BamHI fragments, 18 of the 22 EcoRI fragments, and 6 of the 27 PstI fragments. By restriction endonuclease and Southern blot analysis of cloned or genomic viral DNA fragments, a complete physical map of TnGV was constructed for BamHI, EcoRI, PstI and XhoI. Three interspersed homologous regions (ihs1-ihs3) were identified from hybridization experiments and sequenced. Each TnGV ihs has an approximate size of 400 bp and shows homology to the other two. The orientation of ihs2 is inverted relative to ihs1 and ihs3. TnGV ihs regions do not have repetitive motifs or palindromic sequences, in contrast to homologous regions (hrs) of nuclear polyhedrosis viruses (NPVs). The genomic locations of TnGV ihs1-ihs3, represented in percentage map units, were very similar to those of ihs sequences previously reported in Bombyx mori NPV, suggesting that the ihs may be a novel type of cis-acting element common among baculoviruses. Additionally, an inverted repeat sequence, having overlapping, multiple inverted repeats of 400 bp, was identified to the left of ihs3 on the linearized genome map of TnGV.