Novel Histopathological Findings of Micro Bone Fragments and Epithelial Response in the Oral Mucosa in Bisphosphonate-Related Osteonecrosis of the Jaw.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) occurs in the jawbone and interfacing oral mucosa of patients treated with bisphosphonates. Herein, we report novel histopathological findings in the oral mucosa of a surgical specimen obtained from a 61-year-old man with BRONJ. The resected jawbone and adjacent oral mucosa were separated for histological examination. The mucosal tissue was examined using Von Kossa staining and immunohistochemical (CK5/6, p63) staining of non-decalcified paraffin sections. Pseudoepitheliomatous hyperplasia (PEH), a microscopic feature of the mucosal epithelium in BRONJ, was observed in soft tissue specimens, concomitant with inflammatory cell infiltration. Von Kossa staining revealed small fragments of necrotic bone, tens to hundreds of micrometers in size, scattered within the connective tissues; the PEH forefront contacted some of the bone fragments. Immunohistochemical staining demonstrated that occasionally, the PEH not only contacted but also encompassed the bone fragments. To our knowledge, this is the first report of presence of micro bone fragments and their association with PEH in the oral mucosa in BRONJ.

Improvement of reporter gene assay for highly sensitive dioxin detection using protoplastic yeast with inactivation of CWP and PDR genes.

A yeast reporter gene assay system with improved performance for dioxin detection was established. Since yeast reporter gene assays are relatively simple, easy to handle, and inexpensive, they have been used for various assessments of environmental contaminants. We previously constructed a yeast assay strain expressing the aryl hydrocarbon receptor (AhR) and AhR nuclear translocator (Arnt) carrying the lacZ reporter gene, for detection of dioxins. In the present study, genes encoding cell wall mannoproteins and ATP-binding cassette transporters in the yeast assay strains were deleted in order to increase the substance influx and prevent its efflux. We also established an assay procedure for protoplasts of these yeasts. These modifications improved the detection limit 40-fold and reduced the duration of the assay by 40%. By combining the yeast protoplast and a rapid sample preparation technique using disposal multilayer solid-phase extraction columns to remove unintended aryl hydrocarbons, this yeast reporter gene assay system detected the ligand activities of dioxins and related compounds in 1 g of forest soil containing dioxins at a concentration 10 times lower than the Japanese environmental standard for dioxins in soil.

Relationships between behavioral risk factors and dental care costs in a Japanese worksite.

PURPOSE: To identify the magnitude of dental care costs and examine the relationship between behavioral risk factors and dental care costs in a Japanese corporation. DESIGN: A one-time cross-sectional design was used with each employee as a unit of analysis. SETTING: The setting was a large Japanese corporation where Japan's standard health care insurance, including dental care coverage, was provided for all employees. SUBJECTS: A full-time employee population of 6543 was included. Seventy-six percent were men, and the majority were white-collar workers. MEASURES: Data were available on dental care costs and self-reported behavioral dental care risk, including smoking and oral self-care, obtained from the company's annual physical checkups in the 2000 fiscal year Dichotomous variables of expenditures for employees having no dental claims and those having high claims defined as 90th percentile or above were created. RESULTS: The dental care costs made up approximately 24.3% of the health care costs. Thirty-five percent of the employees were smokers. Employees who were at least 40 years old and employees who were women were associated with the likelihood of using dental care services (odds ratio [OR] = 1.622 and 0.783, respectively), and no behavioral risk was associated. The likelihood of incurring high dental care costs was associated with smoking when including all employees in addition to those who used any dental care services (OR = 1.315 and 1.386, respectively). CONCLUSIONS: This study suggests the relationships of smoking as well as age and sex to dental care costs in an employer setting. To provide a strong case for health promotion in Japan, future research should address critical issues such as reliable and valid risk measurement and the use of longitudinal designs and intervention studies.

[Patients' survey on regular check-up system in dental clinics].

This survey classified the issues involved in promoting the regular check-up system in dental clinics. The survey was conducted in two parts: interviews with 39 dental clinics and a questionnaire survey of 5,129 patients (response rate: 56.8%). The results are summarized as follows: 1. Among the dental clinics that participated in this survey, the proportion of regular patients, the number of dental hygienists working at clinics, and the number of patients per day were higher than those of the national average. 2. The demographic patterns of regularly attending patients were "female, aged under 14 years and students or public servants". 3. Satisfaction with the technical competence of hygienists has the strongest correlation with regularity of visiting. The degree of correlation was about twice that of the correlation with technical competence of the dentist. 4. Patients' priorities for improving dental services to enhance satisfaction were treatment charges, appointment system, and attitude of staff and doctors toward welcoming the patients.

[Comparison of ERCP and MRCP: invasiveness and cost].

The purpose of this study was to compare ERCP and MRCP in terms of invasiveness and cost. A questionnaire regarding patient satisfaction was distributed to 23 ERCP patients and 63 MRCP patients. The practical cost of each examination and total yearly cost for 2002, including medication costs for post-ERCP pancreatitis, were calculated. On a trial basis, the total yearly cost for 2002 was also calculated as a percentage of the cost in 1996. Results of the questionnaire showed that patients tended to favor MRCP over ERCP. In our hospital, the practical costs of MRCP and ERCP were 2063 points and 3964 points, respectively. Medication costs for pancreatitis corresponded to about 3% of the total yearly cost for ERCP. The total yearly costs for both examinations and the medication costs for pancreatitis were about 1,360,000 points. The result of trial calculation with the examination percentage of 1996 was about 1,950,000 points. The results of our study demonstrated that MRCP is a noninvasive examination for patients and that its popularization contributed to a reduction in medical costs. For further popularization of equipment and advanced imaging methods, careful assessment of examination costs is important.