Dental trainees reflect more critically on negative experiences: portfolio analysis using a pragmatic approach and a rubric in Japan.

BACKGROUND: Dental trainees have various clinical experiences during their internships and they grow by experiencing success and failure. When looking back on an event, it is not apparent which experiences result in more critical reflection. Therefore, we qualitatively analyzed the portfolios of dental trainees using Significant Event Analysis to investigate their depth of reflection. METHODS: We asked all Hiroshima University Hospital dental trainees who completed a 1-year training program between 2010 and 2016 to describe their most memorable event from the past year. We coded the text using a qualitative analysis method. Then, we classified the responses as positive or negative events. We evaluated the depth of reflection following a pragmatic approach to categorizing reflective material (Sandars method) and a reflective ability rubric and user guide (O'Sullivan method) and compared these results. The evaluation was performed separately by two researchers and a good rate of agreement was confirmed by the weighted kappa statistic. Comparison of the depth of reflection was performed by the Mann-Whitney U test. RESULTS: The assessments of the positive event group and negative event group were compared with the respective evaluation criteria of the Sandars and O'Sullivan methods, and reflection was found to be deeper in the negative event group. The Mann-Whitney U test revealed a significant difference (p < 0.05) in the median values of the two groups for both methods. CONCLUSIONS: Both positive and negative experiences are important for dental practitioners to grow, but negative experiences are associated with critical reflections. In promoting the growth of training dentists, it is considered important to encourage deep reflections on positive experiences that are likely to be shallow.

Dental hygienists' perceptions of professionalism are multidimensional and context-dependent: a qualitative study in Japan.

BACKGROUND: Due to the declining birth rate and aging of Japanese society, the roles and responsibilities of dental hygienists are continuously expanding. Medical professionalism needs to be pursued continuously throughout one's career in order to improve dental care and treatment. Although conceptualising professionalism is essential to the education of health professionals, professionalism in the field of dental hygiene has not been defined or adequately examined in Japan. The purposes of this study are to investigate dental hygienists' perceptions of the constituent elements of professionalism and the factors affecting their perceptions. METHODS: Semi-structured interviews were conducted with 18 dental hygienists in Japan. Drawing on the conceptualisation of professionalism in medicine described by Van de Camp et al., the transcribed data were thematically analysed. RESULTS: The dental hygienists in this study perceived 70 constituent elements that were categorised into eight core competencies related to professionalism. These competencies were further classified into three main themes: intrapersonal, interpersonal, and public professionalism. There were three sociohistorical factors that affected their perceptions of the constituent elements, namely academic background (university or technical school), the contexts of any previously provided dental care (university hospital or dental clinic), and their social interactions with their colleagues during their engagement in dental practice (dental team or interprofessional team). Moreover, according to their sociohistorical backgrounds, the dental hygienists saw themselves variously as scholars (university graduates), facilitators (university hospital), skillful artisans (dental clinic), or collaborators (interprofessional team). CONCLUSIONS: Dental hygienists' perceptions of professionalism are multidimensional and context-dependent, so culture- and professional-specific elements need to be included in educational curricula and continuing professional development programmes. In particular, the conceptualisation of professionalism in the field of dental hygiene as described in this study can be a springboard for enhancing undergraduate education and clinical training.

Prevalence of drug-resistant opportunistic microorganisms in oral cavity after treatment for oral cancer.

Drug-resistant opportunistic infections may cause health problems in immunocompromised hosts. Representative microorganisms in opportunistic infections of the oral cavity are Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. We investigated the prevalence of drug-resistant opportunistic microorganisms in elderly adults receiving follow-up examinations after primary treatment of oral cancer. Oral microorganisms were collected from patients satisfactorily treated for oral cancer (defined as good outcomes to date) and a group of healthy adults (controls). After identification of microorganisms, the prevalence of drug-resistant microorganisms was studied. Pulsed-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome mec (SCCmec) typing were also performed for methicillin-resistant S aureus (MRSA). Statistical analysis revealed no significant differences in the prevalences of the three microorganisms between the groups. Surprisingly, 69.2% of S aureus isolates showed oxacillin resistance, suggesting that MRSA colonization is increasing among older Japanese. These MRSA isolates possessed SCCmec types II and IV but no representative toxin genes. Our results indicate that a basic infection control strategy, including standard precautions against MRSA, is important for elderly adults, particularly after treatment for oral cancer.

The green tea polyphenol (-)-epigallocatechin gallate precipitates salivary proteins including alpha-amylase: biochemical implications for oral health.

Green tea is a popular drink throughout the world, and it contains various components, including the green tea polyphenol (-)-epigallocatechin gallate (EGCG). Tea interacts with saliva upon entering the mouth, so the interaction between saliva and EGCG interested us, especially with respect to EGCG-protein binding. SDS-PAGE revealed that several salivary proteins were precipitated after adding EGCG to saliva. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) peptide mass fingerprinting indicated that the major proteins precipitated by EGCG were alpha-amylase, S100, and cystatins. Surface plasmon resonance revealed that EGCG bound to alpha-amylase at dissociation constant (K(d)) = 2.74 × 10(-6) M, suggesting that EGCG interacts with salivary proteins with a relatively strong affinity. In addition, EGCG inhibited the activity of alpha-amylase by non-competitive inhibition, indicating that EGCG is effective at inhibiting the formation of fermentable carbohydrates involved in caries formation. Interestingly, alpha-amylase reduced the antimicrobial activity of EGCG against the periodontal bacterium Aggregatibacter actinomycetemcomitans. Therefore, we considered that EGCG-salivary protein interactions might have both protective and detrimental effects with respect to oral health.

PRECEDE-PROCEED model modification in community-based oral health promotion by using the linear structural relations programme.

PURPOSE: The PRECEDE-PROCEED (P-P) model is a framework for designing health education/promotion programmes. While the P-P model has been used to design community-based oral health programmes, outcome assessments of the model are seldom reported. The aim of the present study was to explore whether pathways in the P-P model accurately reflect the current status of environmental/behavioural assessment in a Japanese community and to examine whether using the linear structural relations (LISREL) programme would improve the model. MATERIALS AND METHODS: In a community health centre in Japan, a questionnaire with 29 items regarding oral health was distributed to 824 mothers with 3-year-old children. The items were compiled into eight variables that were tested using the LISREL programme. Goodness-of-fit index (GFI), adjusted goodness-of-fit index (AGFI) and root mean square error of approximation (RMSEA) were statistically analysed before and after P-P model modification. RESULTS: The GFI, AGFI and RMSEA were 0.913, 0.776 and 0.161 before, and 0.975, 0.939 and 0.075 after P-P model modification, respectively. Indirect effects on the quality of life from the predisposing, reinforcing and enabling factors became stronger than those in the initial P-P model. The overall fit of the modified P-P model was significantly better than that of the P-P model without modification, which did not accurately reflect the status of environmental/behavioural assessment in the community. CONCLUSIONS: The modified P-P model reflected the current status of environmental/behavioural assessment in the community. Health education models should be tested rigorously to ensure that they fit the reality of people's behaviour.

Japanese dental trainees' perceptions of educational environment in postgraduate training.

BACKGROUND: Compulsory postgraduate dental training was introduced in April 2006 to meet social requirements in Japan. AIM: The aim of the present study was to identify the difference in trainees' perception of the educational environment in two different training settings in the Hiroshima University Hospital postgraduate training program: (1) main hospitals, in Hiroshima's case, the University Hospital: (2) community dental hospitals or offices (cooperating hospitals). METHODS: In order to determine how trainees perceive their educational environment, the Postgraduate Hospital Educational Environment Measure (PHEEM) Inventory was administered to 50 vocational dental trainees for two different training settings, both of which all trainees had experienced. RESULT: The mean total PHEEM score in the main hospital was 102.4, and that in cooperating hospitals was 108.5. The scores for each of the three subscales were as follows: 'Perception of role autonomy': 33.9/56 (main hospital), 36.8/56 (cooperating hospitals); 'Perception of teaching': 38.1/60 (main hospital), 41,9/60 (cooperating hospitals), and 'Perception of social support': 30.4/44 (main hospital), 29.8/44 (cooperating hospitals) respectively. CONCLUSIONS: PHEEM provided meaningful diagnostic information on the educational environment, and showed that cooperating hospitals met trainees' needs more than main hospitals.

Genetic structure of a population of Potato virus Y inducing potato tuber necrotic ringspot disease in Japan; comparison with North American and European populations.

The structure of Potato virus Y (PVY) populations causing potato tuber necrotic ringspot disease (PTNRD) was analysed. The full-length sequences of the genomic RNAs of five geographically distinct isolates from Japan were determined. Recombination and phylogenetic analyses of European, North American and Japanese isolates of PVY showed that the world PVY population has three major lineages and two sublineages. Most recombinants were interlineage, and one isolate from Europe was identified as an intralineage recombinant. No recombinants were found among Japanese PTNRD isolates, which were most closely related to PTNRD isolates previously found in North America. Comparison of the within- and between population nucleotide diversities in the N lineage sequences from Japan, Europe and North America showed that Japanese population was distinct from the European and North American populations. The nucleotide sequences of the protein 1 and coat protein genes of a further 18 isolates were determined. One Japanese clade had radiated in a star burst as shown by its deviation from the neutral equilibrium model and its small nucleotide diversity. Our results suggest that PVY PTNRD was recently introduced into Japan more than once, and has expanded throughout Japan from founder populations.

Differential gene expression of bone-related proteins in epithelial and fibroblastic cells derived from human periodontal ligament.

Hertwig's epithelial root sheath (HERS) is involved in the differentiation of cementoblasts. The cells of epithelial rests of Malassez (ERM) may contribute to that process. However, little is known about the role of these epithelial cells in cementum repair. In the present study, we investigated the expression of alkaline phosphatase (ALPase), osteopontin (OPN), bone morphogenetic protein (BMP)-2 and BMP-4 in epithelial cells (E cells) and fibroblastic cells (F cells) derived from the same human periodontal ligament. E cells were identified by immunoblotting with anti-cytokeratin 5 and 8 antibody. Reverse transcription-polymerase chain reaction analysis showed that E cells have lower ALPase and BMP-4 mRNA levels than F cells. On the other hand, the expression of OPN mRNA in E cells was stronger than in F cells. No significant difference was observed in BMP-2 expression between E and F cells. Thus, they have different expression patterns of ALPase, BMP-4 and OPN, suggesting that ERM and mesenchymal cells in periodontal ligament may be cooperatively involved in cementum repair. Furthermore, E cell cultures will be useful in elucidating the role of ERM.

Assessing communication skills for medical interviews in a postgraduate clinical training course at Hiroshima University Dental Hospital.

The study was conducted to investigate and clarify the effectiveness of our method of teaching communication and interview skills for medical interviews. Subjects were 18 first-year residents, enrolled in a postgraduate clinical training course at Hiroshima University Dental Hospital. Subjects underwent two objective structured clinical examinations (OSCEs), and the results of instructor and resident assessments of various elements dealing with necessary communication skills for conducting medical interviews were analysed. A statistically significant correlation between assessments of instructors and residents was observed in one element: confirming patient identity and introducing self (r = 0.812, p < 0.001) in the first interview. However, a statistically significant correlation between assessments of instructors and residents was observed in four elements in the second interview: greeting the patient (r = 0.548, p < 0.05), maintaining physical distance (r = 0.582, p < 0.05), showing empathy (r = 0.601, p < 0.05), summarizing and reconfirming patient complaints (r = 0.628, p < 0.01). Total scores given by instructors in the second OSCE were higher than those in the first OSCE (p < 0.001). The correlation coefficients of the total score in the first and second interviews were r = 0.020 and 0.679 (p < 0.01), respectively. These results may suggest the educational effectiveness of OSCE on the acquisition of communication skills for medical interviews. However, the results of resident self-assessments reveal that OSCE should be performed at least twice in order for residents to acquire the necessary communication skills for medical interviews.

Expression of endothelins and their receptors in cells from human periodontal tissues.

OBJECTIVE: The present study investigated the presence of ET-1 in gingival crevicular fluid (GCF) from patients with periodontitis, and the expression of endothelins (ETs) and their receptors mRNA in cultured cells from human periodontal tissues. BACKGROUND: ET was originally discovered as a potent vasoconstrictive peptide from endothelial cells. It has been reported that ETs are produced by various cells besides endothelial cells. ETs are related to inflammatory and sclerotic lesions, such as arteriolosclerosis and hepatic cirrhosis. Therefore, ETs may be involved in periodontal disease. However, the roles of ETs in development and progression of periodontal disease are not clear. METHODS: ET-1 released from the cultured cells was measured by enzyme-linked immunosorbent assay. mRNA expressions for ETs and their receptors were examined by reverse transcription-polymerase chain reaction and Northern blotting analysis. RESULTS: ET-1 levels in GCF from patients with periodontitis were higher than those from healthy subjects. Human gingival keratinocytes (HGK) expressed mRNA for ETs and their receptors, ET-Ar and ET-Br. ET-1 mRNA expression and ET-1 peptide production from HGK were enhanced by interleukin-1beta and tumor necrosis factor-alpha. CONCLUSIONS: These results suggest that ET-1 plays a significant role in periodontal disease.

The effect of extracellular calcium ion on gene expression of bone-related proteins in human pulp cells.

Calcium hydroxide is often used for induction of reparative dentin formation in endodontic treatment. However, little is known about the mechanism by which calcium hydroxide works. The calcium ion (Ca2+) is an important regulator of cell functions. In this study, we examined the effect of extracellular Ca2+ on gene expression of bone-related proteins in human cultured pulp cells in serum-free conditions. A Ca2+ level elevated by 0.7 mM induced an increase in mRNA expression of osteopontin and bone morphogenetic protein (BMP)-2. However, mRNA levels of BMP-4 and alkaline phosphatase decreased under the elevated Ca2+ culture condition. The same concentration of additional magnesium ions had little effect on expressions of the examined bone-related protein mRNAs. These findings suggest that Ca2+ in Ca(OH)2 specifically modulates osteopontin and BMP-2 levels during calcification in pulp.

Immunohistochemical characteristics of epithelial cell rests of Malassez during cementum repair.

To clarify the roles of epithelial cell rests of Malassez (ECRM) during periodontal repair, experimental root resorption was induced in rats and then the ECRM that existed in periodontal ligament during cementum repair was investigated using morphological and immunohistochemical approaches. At day 7, after mechanical injury, root resorption was observed and ECRM were present adjacent to the site of resorption lacunae. They were observed in periodontal ligament adjacent to site of the resorption lacunae. These ECRM were immunoreactive for bone morphogenetic protein-2. During the stage of early cementum repair, the ECRM were immunoreactive for osteopontin and ameloblastin. They strongly reacted to proliferating cell nuclear antigen. In uninjured control sections, ECRM located in the periodontal ligament adjacent to cementum were not immunoreactive for any antibodies. These findings suggested that ECRM may be related to cementum repair by activating their potential to secrete matrix proteins which have been expressed in tooth development.

Proliferative ability and alkaline phosphatase activity with in vivo cellular aging in human pulp cells.

Little is known about the effect of aging on characteristic functions of pulp cells. When damaged pulp is recovered and mineralized tissue is formed to protect remaining pulp tissue, the general responses of pulp tissue after adequate stimuli (pulp cell proliferation and activation of alkaline phosphatase [ALPase]) are thought to be essential. In this study, we compared proliferative ability and ALPase activity between cultures of human pulp (HP) cells obtained from young and aged donors. The in vitro proliferative lifespan of HP cells from young donors was longer than HP cells from aged donors. Growth rates and ALPase activity of HP cells decreased with increasing donor age. These findings suggest that impaired repair of pulp and dentin in aged patients is partly due to a decrease in the proliferative ability and ALPase activity in aged pulp cells.

Effects of transforming growth factor-beta 1 and fibronectin on SPARC expression in cultures of human periodontal ligament cells.

Transforming growth factor-beta(1) (TGF-beta(1)) increases synthesis of secreted protein, acidic and rich in cysteine (SPARC), as well as fibronectin (FN) and type I collagen. However, little is known about the regulatory mechanism of SPARC expression. We examined the effect of FN on SPARC expression by TGF-beta(1) in cultures of human periodontal ligament cells (HPL cells). TGF-beta(1) increased the SPARC and SPARC mRNA levels in HPL cells. Extracellular matrix (ECM) produced by HPL cells in the presence of TGF-beta(1) also increased the SPARC levels. Contents of FN and type I collagen in the ECM were increased by TGF-beta(1). HPL cells cultured on FN-coated plates secreted more SPARC than those on non-coated plates. However, type I collagen had little effect on SPARC levels. The addition of anti-alpha5 antibody to the cultures abolished the increase in SPARC mRNA expression by TGF-beta(1). This study demonstrated that FN may be partly involved in the increase in SPARC expression by TGF-beta(1) in HPL cells.

Osteoprotegerin levels increased by interleukin-1beta in human periodontal ligament cells are suppressed through prostaglandin E(2) synthesized de novo.

Osteoprotegerin (OPG) is a novel tumor necrosis factor receptor superfamily that inhibits osteoclast differentiation, activity, and survival. Interleukin-1beta (IL-1beta) increases OPG expression. IL-1beta also increases prostaglandin E(2) (PGE(2)) production and stimulates bone resorption. In the present study, we examined the involvement of PGE(2) in IL-1beta-induced increases in OPG levels in human periodontal ligament cells (HPL cells) in an effort to clarify apparently conflicting IL-1beta actions on bone resorption and understand IL-1beta-induced increases in secretion of OPG and PGE(2) in HPL cells. 5,6-dichloro-1-beta-D-ribofuranosyl-benzimidazole, a mRNA synthesis inhibitor, partly inhibited the increase in OPG mRNA levels induced by IL-1beta. Cycloheximide, a protein synthesis inhibitor, enhanced the stimulatory effect of IL-1beta. Etodolac, a selective cyclooxygenase-2 inhibitor, suppressed the increase in PGE(2) levels. Furthermore, etodolac reinforced the promotion of OPG expression by IL-1beta at the mRNA and protein levels. PGE(2) added to cultures of HPL cells decreased OPG mRNA levels in a dose- and time- dependent manner. These findings suggest that the increase in OPG levels induced by IL-1beta in HPL cells is suppressed through PGE(2) synthesized de novo.

Potato Tuber Necrotic Ringspot Disease Occurring in Japan: Its Association with Potato virus Y Necrotic Strain.

Unfamiliar necrotic symptoms on or within potato tubers of cultivars Nishiyutaka and Dejima were observed in Nagasaki prefecture, Japan, in 1992. Symptoms were typically on the surface of the tuber, which either protruded at first and then became sunken, or showed necrotic spots, with necrosis within the tubers. Symptoms sometimes appeared at harvesting but more often appeared after storage for several months. Investigations revealed that the causal agents of the disease were isolates of Potato virus Y necrotic strain (PVYNTN) and the disease was potato tuber necrotic ringspot disease (PTNRD), previously reported in Europe and Lebanon. Five potato cultivars were inoculated with an isolate from necrotic tubers. The highest percentage of progeny tubers showing PTNRD was found in cv. Nishiyutaka (23.3%). In contrast, cvs. Shima-bara, Mayqueen, and Danshaku showed a low percentage of PTNRD. Additional potato tubers with PTNRD were also observed after storage of the tubers. To investigate the relatedness between isolates of PVYNTN and of necrotic strain PVYN, previously isolated in Japan, Nishiyu-taka was inoculated with an isolate of PVYN, which also induced PTNRD. Nucleotide sequences of coat protein (CP) genes of six PVYNTN isolates were determined. The CPs were 267 amino acids in length, with a substitution of one or no amino acid among each of the six isolates. The phylogenetic relationship based on nucleotide sequences of CP genes showed that these six PVYNTN isolates clustered together with PVYN isolates. This is the first report of PTNRD caused by PVYNTN isolates in Asia.