Volumetry of simulated bone grafts in the edentulous maxilla by computed tomography: an experimental study.

OBJECTIVE: To determine the precision of CT for calculating the volume of bone grafts to the maxilla. METHODS: Plaster of Paris was used to simulate bone as onlay and inlay grafts to the maxillary alveolus and sinus in a dry skull. Two mm thick axial CT scans were obtained. The area of the graft on each slice was measured and volumes calculated according to the formula V(graft)=Sigma of areas x the thickness of each section. Scans were repeated with the skull at approximately +5 degrees and -5 degrees to the horizontal plane and the calculations repeated. The real volume was calculated by the displaced water technique. Precision was estimated as reliability coefficient. RESULTS: The reliability coefficients for the right and left inlay and the onlay grafts were 0.97, 0.6 and 0.96 respectively. CONCLUSION: Calculations of the volume of both inlay and onlay grafts to the maxilla from axial CT is precise.

Pharmacokinetic and toxicity profile of a phosphorothioate oligonucleotide following inhalation delivery to lung in mice.

Antisense oligonucleotides are currently being investigated for the treatment of a variety of diseases. Antisense drugs are being administered primarily by parenteral injection. To explore more convenient patient delivery methods, we have characterized the tissue kinetics and tolerability of an inhaled aerosol formulation of a phosphorothioate oligonucleotide in mice. Concentrations of oligonucleotide in bronchioalveolar lavage fluid, plasma, and tissue and immunohistochemical localization were used to assess deposition and pharmacokinetic parameters. Significant concentrations of oligonucleotide in lung, as well as systemic tissues, were measured following a pulmonary dose of 12 mg/kg. Doses as low as 1-3 mg/kg also produced significant concentrations of oligonucleotide (>50 microg oligonucleotide per gram of tissue), and these were maintained in the lung with a halflife of 20 hours or greater. Oligonucleotide was localized to bronchiolar epithelium and alveolar epithelium and endothelium. Toxicity was mild at the 12 mg/kg level and minimal to absent at doses of 3 mg/kg or below. Based on a favorable pharmacokinetic profile and a relative lack of toxicity, inhalation delivery appears to be a therapeutic option for antisense oligonucleotides.

Facile preparation of 1,6-anhydrohexoses using solvent effects and a catalytic amount of a Lewis acid.

Refluxing solutions of monosaccharides, unprotected at the 6-position and carrying O-methyl, S-ethyl, O-acetyl and OH-groups at the anomeric center, in acetonitrile containing a catalytic amount of a Lewis acid (O.1-0.4 equiv.) yielded 1,6-anhydrohexopyranoses in good to high yields. Best results were obtained with methyl 2,3,4-tri-O-dideuteriobenzyl-alpha-D-glycosides (87-91%). Dideuteriobenzyl protective groups were used to facilitate NMR spectral interpretations.