Perceptions and attitudes of Canadian orthodontists regarding digital and electronic technology.

INTRODUCTION: To plan for future acceptance and implementation of computer-related technology, it is necessary to understand orthodontists' current perceptions and attitudes toward emerging technologies. METHODS: An anonymous, self-administered, mail-out survey of Canadian orthodontists was conducted. The response rate was 45.6% (304/667). RESULTS: Most orthodontists indicated that computer technology could improve current practice efficiency and quality of patient care. Only 15% reported that digital models are quite or very useful; 73.6%, 69.1%, 55%, and 37.4% agreed or strongly agreed with using digital and electronic technology to consult with other dental specialists, other orthodontists, general dentists, and the public, respectively. Cost of the technology was reported as a significant or insurmountable obstacle by 54% of the respondents. Interprovincial legislation, unclear consultation remuneration guidelines, and lack of comfort with the technology were not perceived as significant obstacles. Only 36% reported security or privacy issues as a significant or insurmountable obstacle. CONCLUSIONS: Canadian orthodontists seem to view digital and electronic technology as useful and capable of improving their offices' efficiency and production. Although they are sensitive to some potential obstacles, they are willing to overcome these and incorporate the technology into their practices.     

Use of the risk-rescue rating scale with adolescent suicide attempters: A cautionary note

The assessment of the medical lethality and intent of suicide attempts has been considered an important area of research for those interested in suicide. The current study examined the usefulness of the Risk-Rescue Rating Scale with 109 adolescent suicide attempters and found a restricted range of variability, which, in turn, resulted in poor interrater reliability on a number of items. Results suggest that the Risk-Rescue Rating Scale is of limited usefulness with adolescents, and alternative approaches to assessing lethality and suicidal intent with this age group are discussed.     

Classification tree analysis of second neoplasms in survivors of childhood cancer

Background  

Reports on childhood cancer survivors estimated cumulative probability of developing secondary neoplasms vary from 3,3% to 25% at 25 years from diagnosis, and the risk of developing another cancer to several times greater than in the general population.     

Co-operative mineralization and protein self-assembly in amelogenesis: silica mineralization and assembly of recombinant amelogenins in vitro

An amorphous silica mineralization technique was used to produce inorganic/protein composites to elucidate the structure and mechanism of formation of amelogenin assemblies, which may play an important role in regulating enamel structure during the initial stages of amelogenesis. Full-length recombinant amelogenins from mouse (rM179) and pig (rP172) were investigated along with key degradation products (rM166 and native P148) lacking the hydrophilic C terminus found in parent molecules. The resulting products were examined using transmission electron microscopy and/or small-angle X-ray scattering. Using protein concentrations of 0.1–3 mg ml⁻¹, large monodisperse spheres of remarkably similar mean diameters were observed using rM179 (124 ± 4 nm) and rP172 (126 ± 7 nm). These spheres also exhibited 'internal structure', comprising nearly spherical monodisperse particles of ≈ 20 nm in diameter. In the presence of rM166, P148, and bovine serum albumin (control), large unstructured and randomly shaped particles (250–1000 nm) were observed. Without added protein, large dense spherical particles of silica (mean ≈ 500 nm) lacking internal structure were produced. These findings demonstrate that full-length amelogenins have the ability to form higher-order structures, whereas amelogenins that lack the hydrophilic C terminus do not. The results also suggest that full-length amelogenin can guide the formation of organized mineralized structures through co-operative interactions between assembling protein and forming mineral.     

Phase I and pharmacokinetic study of gefitinib in children with refractory solid tumors: a Children's Oncology Group Study.

PURPOSE: Epidermal growth factor receptor is expressed in pediatric malignant solid tumors. We conducted a phase I trial of gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, in children with refractory solid tumors. PATIENTS AND METHODS: Gefitinib (150, 300, 400, or 500 mg/m2) was administered orally to cohorts of three to six patients once daily continuously until disease progression or significant toxicity. Pharmacokinetic studies were performed during course one (day 1 through 28). RESULTS: Of the 25 enrolled patients, 19 (median age, 15 years) were fully evaluable for toxicity and received 54 courses. Dose-limiting toxicity was rash in two patients treated with 500 mg/m2 and elevated ALT and AST in one patient treated with 400 mg/m2. The maximum-tolerated dose was 400 mg/m2/d. The most frequent non-dose-limiting toxicities were grade 1 or 2 dry skin, anemia, diarrhea, nausea, and vomiting. One patient with Ewing's sarcoma had a partial response. Disease stabilized for 8 to > or = 60 weeks in two patients with Wilms' tumor and two with brainstem glioma (one exophytic). At 400 mg/m2, the median peak gefitinib plasma concentration was 2.2 microg/mL (range, 1.2 to 3.6 microg/mL) and occurred at a median of 2.3 hours (range, 2.0 to 8.3 hours) after drug administration. The median apparent clearance and median half-life were 14.8 L/h/m2 (range, 3.8 to 24.8 L/h/m2) and 11.7 hours (range, 5.6 to 22.8 hours), respectively. Gefitinib systemic exposures were comparable with those associated with antitumor activity in adults. CONCLUSION: Oral gefitinib is well tolerated in children. Development of the drug in combination with cytotoxic chemotherapy will be pursued.