Fluorescent N-methylanthranilyl (Mantyl) tag for peptides: its application in subpicomole determination of kinins.

Highly fluorescent N-methylanthranilyl (Mantyl) peptide derivatives were prepared by a one-step reaction with N-methylisatoic anhydride (MIA) for quantitative detection in HPLC. Reactions were carried out in an organic medium of acetonitrile-triethylamine, in aqueous alkaline sodium carbonate and sodium phosphate buffers. 4-Dimethylaminopyridine (DMAP) catalyzed specific mantylation of -NH2 groups of peptides in the organic reaction medium. The DMAP had no effect in the aqueous buffered reaction systems. Proline amino-terminal peptides reacted equally well with MIA. Mantyl-bradykinin had excitation and fluorescence maxima at 350 nm and 426 nm in water and water/acetonitrile (ACN)/trifluoroacetic acid (TFA) solvent mixtures, respectively. Fluorescence intensity increased with an increase in ACN concentration and decreased with an increase in acid content. Mantyl kinins were completely resolved on a C18 reversed phase HPLC column using an ACN-0.1% TFA gradient and their behavior on the column was similar to having an extra amino acid. Di-Mantyl derivatives obtained with Lys-BK and Met-Lys-BK did not exhibit fluorescence appreciably higher than Mantyl-BK. Fluorescence detection of Mantyl kinins was about 50-100 times more sensitive (lower limits of 0.1 to 0.5 picomole) than UV detection of the phenylisothiocyanate-derivatized kinins under typical HPLC conditions.

[Temperature measurements in the pulp chamber during onlay and inlay preparation]. / Temperaturmessungen im Pulpakavum während der Onlay- und Inlaypräparation.

The effect of fast turning burrs and diamond points upon teeth during cavity preparation was tested in a model experiment under laboratory conditions, in order to establish possible damaging effects upon the pulp through an increase in temperature. The most effective protection comes from water cooling. Also successful was the technique of intermittent instead of continuous preparation. Only methods currently used in practice were tested thus making the test particularly valuable to daily practice. Thus it could be proved that the use of super-torque airotors as well as of the micromotor cannot cause thermic damage to the pulp if used circumspectively.

Bond strengths of three resin systems used with brackets and embedded wire attachments.

Orthodontic wire bonded directly to teeth with a resin adhesive system has been used to establish anchor units for procedures in orthodontics as well as for splinting teeth in other disciplines. This procedure can save the cost and time of placing a bracket. In addition, several different resin systems have been used for this procedure as well as for placing brackets. The purpose of this study was to determine the strength of three adhesive systems used to bond orthodontic wires directly to teeth and to compare these values with those found for directly bonded orthodontic brackets. Equal sample sizes of brackets or wires were attached to 240 human teeth with either Concise, Miradept, or Endur in a standardized area of etched enamel. Shear and tensile strengths were measured at 30 minutes and at 48 hours. At 30 minutes brackets were significantly stronger than embedded wires, and Concise was significantly stronger than either of the other resins. However, all significant differences between any of the three resin systems using either bonded brackets or wires disappeared at 48 hours. Whether or not this initial strength difference is clinically significant remains speculative.