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Elevated plasma norepinephrine (NE) levels is a relatively consistent clinical effect of clozapine. Plasma NE levels reflect an interplay of release, reuptake, metabolism, and excretion. To explore the mechanism of clozapine-induced plasma NE elevation, we measured arterial plasma levels of NE and other catechols during intravenous infusion of tritium-labeled NE (3H-NE) in schizophrenic patients treated with clozapine, fluphenazine, or placebo. Clozapine-treated patients had markedly higher levels of NE than did the patients treated with fluphenazine or placebo. NE spillover averaged more than three times higher in clozapine-treated patients; whereas NE clearance did not differ among the groups. Production of 3H-dihydroxyphenylglycol (3H-DHPG), a purely intraneuronal metabolite of 3H-NE in clozapine-treated patients was normal, indicating that clozapine did not affect neuronal uptake of NE. Because plasma levels of DHPG and dihydroxyphenylacetic acid (DOPAC), deaminated metabolites of catecholamines, in clozapine-treated patients were normal, clozapine also did not seem to inhibit intraneuronal monoamine oxidase (MAO). High plasma NE levels in clozapine-treated patients, therefore, resulted from increased NE spillover rather than decreased reuptake, metabolism, or clearance.

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This study evaluated the clinical performance of a visible light-cured small particle bimodally filled hybrid condensable composite resin system that included a dentin bonding agent compared with an amalgam alloy in class II restorations of permanent teeth. A total of 108 restorations were placed in 34 patients. Fifty-three composite resin and 55 amalgam restorations were inserted. Each restoration was evaluated immediately after placement and then on an annual basis for a 3-year period using the Public Health Service (PHS) criteria. In addition, the Moffa-Lugassy scale was used to measure the loss of material on the occlusal surface of these materials. One hundred percent of the resin and amalgam restorations were evaluated, measured, and reasons for replacement were recorded over the 3-year period. There was no significant difference (p greater than 0.05) in the clinical performance of the composite resin and the amalgam when evaluated by the PHS criteria. Analyses of wear at each of the three annual recall periods did not reveal any significant difference (p greater than 0.05) between the two restorative materials when measured by the Moffa-Lugassy scale.

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Supernumerary teeth in the maxillary midline can present both esthetic and pathologic concerns that can be difficult to solve. The frequency with which supernumerary teeth occur justifies an oral radiographic survey for preschool children as early detection is most important, if such complications are to be avoided or minimized. The case presented in this report required both surgical and innovative orthodontic therapy to bring an unerupted, impacted maxillary central incisor into proper alignment. The tooth was moved into the dental arch and injury to the root structure and surrounding oral tissues was avoided by using a combination of conservative surgical and orthodontic therapy.

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We describe here and validate an in vivo technique to measure the regional proportionate removal of norepinephrine (NE) by neuronal uptake (Uptake1) in man. The measurement is based on the steady-state arterial and venous concentrations of tritiated NE and tritiated isoproterenol (ISO) during simultaneous infusion of both. The validity of this technique depends on the removal of circulating NE, but not of ISO, by sympathetic nerve endings and on there being no other factor contributing to the net difference in the plasma disappearance of these catecholamines. To test these hypotheses, we compared the removal of NE in the arm with that of ISO in 14 people and the effects of pretreatment with the specific inhibitor of Uptake1, desipramine, in 8 people. In all the subjects a greater percent of NE than of ISO was removed during passage of blood through the forearm (54 vs. 46%, P less than 0.0001). Pretreatment with desipramine decreased significantly the removal of NE to virtually exactly that of ISO. The difference in NE and ISO clearances by arm tissues was therefore completely accounted for by Uptake1. About 15% of infused NE which is removed in the arm is removed by Uptake1. The ability to measure regional Uptake1 should contribute to better understanding of the relationship between circulating levels of plasma NE and sympathetic neural activity and may allow detection of abnormalities of neuronal norepinephrine removal in clinical disease states.

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The correction of malocclusions in juvenile periodontitis (JP) patients completing periodontal therapy is a problem of increasing clinical concern to orthodontists, since many teeth with severe alveolar bone loss in these patients can now be successfully treated without extraction. In this report, fixed edgewise orthodontic therapy was carried out after the completion of periodontal therapy on four JP patients. The orthodontic therapy included extensive intrusion of teeth severely affected by JP. Phase-contrast microscopic analysis of subgingival plaque from orthodontically treated teeth was used to monitor longitudinally the effects of fixed orthodontic bands on the subgingival flora and also to monitor the efficacy of topical and systemic antimicrobial therapy aimed at suppression of suspected periodontopathic bacteria. Orthodontic movement was completed on most periodontally compromised teeth without significant evidence of additional deterioration in periodontal status. However, within the first 6 months of orthodontic band placement, all patients had significant increases in the number of spirochetes and motile rods in their subgingival flora. Three of the patients also developed high levels of crevicular polymorphonuclear leukocytes around orthodontically treated teeth, indicating significant subgingival inflammation. Intensive antimicrobial measures, including topical inorganic salt applications and systemic tetracycline, were helpful in limiting clinical inflammation and subgingival colonization by periodontopathogens during orthodontic therapy. The results demonstrate that successful orthodontic repositioning can be carried out in treated JP patients. In addition, bacteriologic monitoring and chemotherapeutic suppression of periodontal pathogens may be valuable in the prevention of further destructive periodontal disease activity in periodontitis patients undergoing orthodontic therapy.

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There have been only a few published reports on the dental-facial effects of radiation therapy and the subsequent oral management of these patients. A case involving a 13-year-old black male patient with a history of rhabdomyosarcoma is presented. The patient received 4,050 rads of radiation to the right middle ear when he was 2 years of age. His residual medical and dental difficulties are apparently complications from the initial therapy. Examination of the oral cavity revealed bimaxillary micrognathia and marked loss of vertical dimension. A Class II facial profile with Class I molar relationship was observed. The mandible was thin and hypoplastic, with a small knife-edge alveolar ridge. The remaining eighteen erupted permanent teeth were very mobile, and root development had ceased after only initial formation. All of the teeth except the first permanent molars were extracted, and immediate partial dentures were inserted at the time of surgery. A discussion of therapeutic considerations follows the case report.

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Eight ingredients of composite materials were evaluated individually for pulp irritation. None caused significant inflammation as evidenced by its average response. No abscess formations or lesions predominating in leukocytes occurred.

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Diagnostic performance based on a double-blind evaluation of test and control radiographs produced from nine different fractured cadaver skulls was compiled for six radiologists. The data resulting from two different diagnostic tasks were analyzed statistically for accuracy and confirmed interpretability including an assessment of task-related performance differences. Performance was found to be relatively independent of differences among radiologists and lesion location. Little overall correlation was found to exist between demonstrated ability to detect lesions radiographically, and visual confirmation of known lesions from the same films. These results suggest that overall performance was probably limited by a number of undefined clinical factors which influence the amount of meaningful information available from the resulting radiographs. The distribution of these degrading influences was not uniform within the population sampled so that certain radiographs proved to be particularly misleading when considered in terms of their apparent diagnostic value. As a result, even relatively large depressed fractures were in some instances considered radiographically uninterpretable.

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