Nuclease digestion and mass spectrometric characterization of oligodeoxyribonucleotides containing 1,2-GpG, 1,2-ApG, and 1,3-GpXpG cisplatin intrastrand cross-links.

Background: The primary mode of action for cis-diamminedichloroplatinum (II), referred to as cisplatin, toward the treatment of solid malignancies is through formation of cross-links with DNA at purine sites, especially guanines.

Methods: We prepared oligodeoxyribonucleotides (ODNs) containing a 1,2-GpG, 1,2-ApG, or 1,3-GpXpG cisplatin intrastrand cross-link and the corresponding ODNs modified with (15)N2-labeled cisplatin, and characterized these ODNs with electrospray ionization mass spectrometry (ESI-MS) and tandem MS (MS/MS). We also employed LC-MS/MS to characterize the digestion products of these ODNs after treatment with a cocktail of 4 enzymes (nuclease P1, phosphodiesterases I and II, and alkaline phosphatase).

Pre-surgery psychological characteristics, pain response, and activities impairment in female patients with repeated periodontal surgery.

This study assessed relationships between pre-surgery psychological characteristics and post-surgery pain response and impairment of life activities following each of two sessions of periodontal surgery. Forty-two female periodontal patients between the ages 26 and 67 participated. None had experienced previous peridontal surgery.

Colonization of retrieved polytetrafluoroethylene membranes: morphological and microbiological observations.

Polytetrafluoroethylene membranes (ePTFE) used in guided tissue regeneration (GTR) are accessible to colonization by oral bacteria. The bacterial composition of the adherent biomass is unknown. We examined a total of 6 membranes that were retrieved after 4 to 6 weeks from human periodontitis sites, using optical and transmission electron microscopy (TEM) as well anaerobic cultivation.

Autosomal recessive rough hypoplastic amelogenesis imperfecta. A case report with clinical, light microscopic, radiographic, and electron microscopic observations.

A case is presented of a 12-year-old Japanese girl with nearly complete lack of enamel in the deciduous and the permanent dentitions, coupled with a gross abnormality in the pattern of eruption. There was no family history of a similar condition. Deciduous molars were extracted, and hyperplastic gingival tissue was resected.

The microscopic distribution of tetracycline in human teeth.

The distribution of tetracycline fluorescence was studied in a random collection of 378 teeth extracted in 1976 in Farmington, Connecticut, using ultra-violet microscopy of longitudinal ground sections. The sample consisted of 4 deciduous molars and the following numbers of permanent teeth: 72 incisors, 41 canines, 63 premolars, 26 first molars, 24 second molars, and 148 third molars. Narrow fluorescent lines reflecting short regimens of drug administration and broad bands corresponding to long term administration were identified in the dentin and tabulated in relation to their anatomical position.

Response of the periodontal tissues of the beagle dog to polytetrafluorethylene implants.

The healing response of the periodontal tissues to polytetrafluorethylene was examined in the beagle dog. At midroot level, by way of a mucosal incision and a surgically created fenestration in the facial alveolar bone, a cylinder of polytetrafluorethylene 2 mm. in diameter was fitted tightly into a cavity preparation and cut even with the root surface.

Performance appraisal: if only people were not involved.

While performance appraisal systems which emphasize work objectives and behavioral rating scales hold considerable promise for improving the evaluation process, an incomplete understanding of the human dynamics underlying the appraisal process blunts their attraction. For a technically sound appraisal system to work, four behavioral elements are necessary: trust, acceptance of the appraisal function by those who must do the evaluation, sensitivity to the inner world of performance evaluation, and training designs which recognize the human dynamics of appraisal.

The quality of restorative dental care.

This study investigated the quality of restorative care in a group of health center employees. With limitations in sample size, representativeness of the sample, and methods of measuring quality clearly recognized, the results of the study suggest that significant improvements in the quality of amalgams, synthetic restorations, crowns, fixed partial denture abutments, and pontics will probably require advances in the science and technology of dentistry and modifications in the present system for delivering dental care. The impact of a quality review system is unlikely to affect the care provided by the majority of dentists.

The microscopic pattern of tetracycline fluorescence in the cementum of human teeth.

Ultraviolet microscopy of longitudinal non-decalcified sections revealed fluorescence characteristic of in vivo tetracycline deposition in the cementum of 55 out of 378 human permanent teeth. Patterns of fluorescence could be related to various stages in root development and to pathological events, as well as to the approximate duration of drug intake. Cementum lines formed during apposition of primary root dentin were associated with dentin bands and met the latter at the cemento-dentinal junction: other lines corresponded to incremental cementum apposition after completion of the root.

Ultrastructure of Mutants of Streptococcus mutans with Reference to Agglutination, Adhesion, and Extracellular Polysaccharide.

An electron microscopic study of S. mutans 6715-13 wild type and representatives of three distinct classes of glucan synthesis-defective mutants (which fail to form adherent microbial plaques but agglutinate normally in the presence of exogenous glucans) disclosed the presence of two sucrose-dependent, glucanase-sensitive, extracellular components. In the wild type, these extracellular glucans had predominantly fibrillar (with some globular) morphologies.