Characteristics of dental materials in the oral cavities of Asian individuals between their 20s and early 40s living temporarily in Japan based on 38 case studies.

Characterization of materials used in dental restorations and fixed prostheses is useful for personal identification. This study investigated the dental treatment trends and use of metal materials among non-Japanese Asian temporary residents and Japanese individuals aged from 20 to 40 years living in a city in Japan. Analysis of 38 participants from different Asian countries showed prominent use of resin fillings, with metal element analysis revealing nickel-chromium (Ni-Cr) or cobalt-chromium (Co-Cr) alloys. Among five Japanese participants of the same age with dental metal treatment scars, resin fillings and silver-palladium-copper-gold (Ag-Pd-Cu-Au) or silver-indium (Ag-In) alloys were observed. This study suggested some regional differences in dental material choices in Asia.

Metal component of dental restorations and fixed prostheses in the oral cavity of 43 cases of adults aged 55 years or older in forensic autopsy.

Characterization of the metal component of dental restorations and fixed prostheses is useful for the treatment of dental metal allergies and personal identification. This study aimed to describe the composition of metal elements in dental restorations and fixed prostheses in the oral cavity of 43 cadavers of Japanese adults aged 55 years or older in forensic autopsies conducted at a university. In this study, Ag-Pd-Au alloys were most frequently detected, and the percentage of Ni alloys was smaller than that reported in patients with dental metal allergies. Furthermore, alloys containing other elements, such as Fe or Hg, were also detected in some cases.

A case report of allergic reaction with acute facial swelling: a rare complication of dental acrylic resin.

Resin components, such as methyl methacrylate (MMA) can cause allergic contact dermatitis (ACD). Allergic reactions to resin are usually delayed. Only a few studies have reported dental resin allergy with acute symptoms. Here, a case of ACD with acute facial swelling after dental treatment using resin material is reported. A 55-year-old woman with a history of periungual inflammation when using gel nail polish had repeated episodes of facial swelling after dental treatment with resin material. The resin temporary crown was removed, and symptoms were alleviated with antihistamines and corticosteroids. With the suspicion of resin allergy, skin tests were performed. Patch testing revealed positive reactions to self-adhesive resin cement (primer and polymerized), self-curing acrylic resin (liquid and polymerized), 2-hydroxyethyl methacrylate (2-HEMA), and ethylene glycol dimethacrylate (EGDMA), whereas the prick test was negative for all allergens. Complement C4 and C1 inhibitor activity were reference values in the tests for hereditary angioedema. Based on these findings, the patient was diagnosed with ACD to 2-HEMA and EGDMA. Since diagnosis, no similar symptoms have been observed in subsequent dental treatment with non-resin materials. The use of dental resin materials may cause ACD with an acute reaction. This report alerts dentists who routinely use resin materials.

Age estimation using post-mortem computed tomography and fetal dental radiographic findings in an early to mid-pregnancy fetus: A case report.

Parameters for body size growth are essential to evaluate the relationship between fetal growth and accurate age estimation in forensics. Size values measured postmortem are also affected by the postmortem environment. On the contrary, when using hard tissue maturation criteria, age estimation remains unaffected by the degree of fetal preservation. In Japan, a fetus dying 12 weeks after pregnancy must be reported as a stillbirth. A Japanese stillborn infant buried without reporting to the authorities underwent a forensic autopsy. The gestational age was 4-5 months, based on the mother's description. The body was not fixed, and it was macerated and flattened along the sagittal plane; therefore it was difficult to correctly measure indicators involving soft tissue. The bone size and tooth development were evaluated using postmortem computed tomography (CT) images and intraoral radiography to estimate the age. Considering all the information, including age estimation based on bone sizes referenced in a Japanese study, calcified upper central incisors, we estimated fetal gestational age for our sample as 14-17 gestational weeks finally. However, there were discrepancies between age estimations based on bone size (20-25 gestational weeks, bone radiographic imaging standards; or 4-6 gestational months, an average of the extremity-bones by a Japanese study) and tooth development (14-17 gestational weeks). Deep discussions based on multiple indices with professionals should be applied to forensic age estimation since existing methods may be based on data for different races, use other measurement tools, or apply different sample conditions even if the targets are the same.

Dental radiographic information of term newborn babies within the first month: Analyzing five radiographic cases along with physical attributes in Japan.

BACKGROUND: Although dental radiography is a valuable tool for age estimation in forensic anthropology and odontology, very limited radiological data are available regarding tooth development in healthy newborn babies during the first month of life. AIM: This study aimed to describe the radiological findings of tooth development in babies aged 0 days to 1 month. DESIGN: We analyzed the postmortem findings of five newborn babies with no known natural cause of death who had undergone autopsy, computed tomography (CT), and dental radiography. We estimated the gestational age for the babies aged 0 days and analyzed the condition of mandibular symphysis, existence of tooth germs, and presence or absence of calcification of the first permanent molars of all the babies. RESULTS: The calcified form of 20 deciduous teeth, tooth germs of the permanent upper and lower first molars, and non-calcified mandibular symphysis were observed in each case. However, calcification of the first permanent molar was observed in only two 1-month-old babies. CONCLUSION: The dental radiographic findings and anthropometric measurements of non-skeletonized, non-mummified term babies confirmed calcification of all the deciduous teeth and the first permanent molar at the age of 0 days and 1 month, respectively.

Four cases of cytokine storm after COVID-19 vaccination: Case report.

The global coronavirus disease 2019 (COVID-19) pandemic has led to the rapid development of vaccines against this disease. Despite the success of the international vaccination program, adverse events following vaccination, and the mechanisms behind them, remain poorly understood. Here we present four cases of death following receipt of a second dose of COVID-19 vaccine, with no obvious cause identified at autopsy. Using RNA sequencing, we identified genes that were differentially expressed between our post-vaccination cases and a control group that died of blood loss and strangulation. Three hundred and ninety genes were found to be upregulated and 115 genes were downregulated in post-vaccination cases compared with controls. Importantly, genes involved in neutrophil degranulation and cytokine signaling were upregulated. Our results suggest that immune dysregulation occurred following vaccination. Careful observation and care may be necessary if an abnormally high fever exceeding 40°C occurs after vaccination, even with antipyretic drugs.

Some tips on age estimation using DNA methylation in saliva samples as an index across the Japanese and Indonesian ethnicities.

Age estimation of unidentified bodies is of marked importance in forensic medicine. In previous studies, the analysis of DNA methylation in body fluids led to the identification of several age-related CpG sites in genes such as EDARADD and FHL2. However, limited information is available on whether interethnic differences may affect the age prediction results. In the present study, we examined the effect of ethnicity on the age prediction method based on methylation scores, which were determined via methylation-sensitive high-resolution melting. We found that there was a significant difference in methylation scores between Japanese and Indonesian participants of early 20 s group, and that the nationality coefficient was significant for age estimation when applying the existing method for the analysis of the methylation status of EDARADD and FHL2. This suggests that when using certain biochemical indicators as a predictor of age, the effects of ethnicity on DNA methylation should be considered to improve the accuracy of the estimation.

How school life with international students develops the intercultural competence of domestic dental students.

INTRODUCTION: Reflecting multicultural society, the diversity of the healthcare professional students' ethnicities and cultures is promoted around the world. However, most of the healthcare professional education in Japan had been targeted mainly at students who follow the Japanese language and culture. The aim of this study is to clarify what Japanese dental students have culturally experienced and how they developed intercultural competence during their school life with international dental students in Japan. MATERIALS AND METHODS: We conducted semi-structured interviews with 18 of the sixth-grade students in standard Japanese undergraduate dental programmes who shared required classes in Japan with non-Japanese-speaking international dental students in preclinical programmes. Based on the qualitative analysis of the interviews, we administered a questionnaire survey to 82 dental trainees (the seventh grade) in clinical training programmes who just graduated from various Japanese dental schools. Then, the answers of the questionnaire were statically analysed. RESULTS: The interview identified a total of 37 constituent elements regarding "students' attitudes and experiences in school days" and "perceptions and motivations." Analysis of the questionnaire showed that the group experiencing a learning environment with international students had various communication with and respect for their various classmates and had the ambition to develop themselves. Especially, the participants who had international experiences both in and out of classrooms showed more active attitude on intercultural communication. CONCLUSIONS: Overall, for Japanese dental students, daily contact with international students gave direct and indirect cross-cultural experiences and recognitions. In particular, the Japanese students were stimulated active perceptions. The findings of this study can be used for future discussion about the cross-cultural education and collaboration of healthcare professionals not only within Japan but also around the world.

Selective and easy detection of the Porphyromonas gingivalis fimA type II and IV genes by loop-mediated isothermal amplification.

Porphyromonas gingivalis fimbrillin (fimA) type II and IV, the definitive factors for periodontitis, are also found to be associated with systemic diseases. To detect the fimA type II and IV genes easily and rapidly, we used the loop-mediated isothermal amplification (LAMP) method. The LAMP method showed high specificity as DNA from the P. gingivalis HW24D1 strain could only be amplified by the type II-specific primers and that from the W83 strain could only be amplified by the type IV-specific primers. Pathogens, namely, Streptococcus sobrinus, S. mutans, and Candida species, lack the type II and IV genes, and hence, were not detected by the LAMP reaction. Both bacterial cells and purified DNA could be used in the LAMP reaction. The LAMP reaction was highly sensitive and both type II and type IV genes could be detected in 1000 DNA molecules. In the bacterial suspensions of HW24D1 and W83 strains, type II and type IV genes, respectively, could be detected in 100 bacterial cells. We examined the type II and type IV genes in the dental plaques from 22 P. gingivalis-positive patients using the LAMP method. Only one person was found to be positive for the type II gene (4.5%). For the type IV gene, 3 positive cases (13.6%) were identified. Moreover, type II and type IV genes could be detected simultaneously using a multiplex amplification primer of fimA type II and type IV, under visible light. Thus, we established a selective and easy method to detect P. gingivalis fimA type II and IV genes using LAMP.

Rapid detection of the Streptococcus mutans cnm gene by loop-mediated isothermal amplification.

This study investigated a method using loop-mediated isothermal amplification (LAMP) for the rapid detection of cnm-positive Streptococcus mutans (S. mutans) associated with cerebral microhemorrhage. LAMP amplified the cnm gene plasmid vector, but not human or microbial genomic DNA. The cnm DNA of the cnm-positive S. mutans strain was detected in saliva without DNA extraction after 1 day of culture. This method resulted in a cnm-positive rate of 26.4% in 102 samples, which was higher than that obtained with conventional PCR. In conclusion, LAMP may be used for the detection of cnm-positive S. mutans in a large number of samples.

Current status of dental metal allergy in Japan.

PURPOSE: To assess the current status of patients with dental metal allergies in Japan. METHODS: This study analyzed dental metal allergy in 1225 patients (1:3 male to female ratio; average age 53.0 ±16.5 years), including 300 who were scheduled to undergo dental implant surgery, between 2006 and 2016. For diagnosis of metal allergy, patch tests using metal allergens were performed. Additionally, when necessary, metal element analysis of dental alloys was performed in the mouths of some patients using an X-ray fluorescence analyzer for those who exhibited positive reactions. RESULTS: Among 925 patients (i.e., excluding those scheduled to undergo dental implant surgery [n=300]), nearly one-half (44.0%) exhibited a positive response to any metal element in the patch test. The positivity rates were as follows: nickel (22.5%); palladium (14.8%); and zinc (11.5%). Almost one-half (42.3%) of the patients had diseases associated with metal allergy. Among patients who exhibited a positive reaction to any metal element in the patch test, more than two-thirds (67.9%) had dental alloys containing the positive metal element(s). One-half (55.6%) of the patients who underwent treatment to remove the metal experienced improvement in symptoms. In patients who underwent patch testing as an implant preoperative examination, several (2.7%) exhibited a positive reaction to titanium. CONCLUSIONS: Dental metals, including nickel, palladium and zinc, which are indispensable to dental treatment in Japan, had high positivity rates in patch testing, and one-half of the patients improved following removal of the metal. Additionally, there were several patients with allergy to titanium.

Study of factors related to the attitudes toward studying abroad among preclinical/clinical undergraduate dental students at three dental schools in Japan.

Despite of their general interests in studying abroad, there are two types of dental student in Japan. They are those who decide to go studying abroad and those who do not. The aim of this study was to clarify the factors related to the attitudes toward studying abroad among preclinical/clinical undergraduate dental students who attended three dental schools in Japan. A questionnaire was used to assess undergraduate dental students' attitudes toward studying abroad. We analyzed the differences between junior (preclinical) students and senior (clinical) students on concerns, and relationships between personality traits based on the Big Five and experiences related to studying abroad. Four hundred and thirty-nine undergraduate students completed the questionnaire. The senior dental students were more worried, more than the junior students, about "lack of language ability in daily life," "higher quality facilities and environment," and valued "dental/medical knowledges and skills" and "advantage for getting a job" through studying abroad. Both junior and senior students with experience of/plans for studying abroad reported significantly higher levels of openness to experience than those without such experiences or plans. The less-open group was more concerned with "lack of language ability in daily life/academic fields," "higher quality facilities and environment," "life in a foreign country," "interpersonal relationships in foreign countries," and "no friends in foreign countries" than the open-group. Although the preclinical and clinical dental students at the three dental schools in Japan had different views of concern for studying abroad, "openness to experience" might be a common key factor related to their studying abroad. However, apart from any personality factor, alleviating students' concerns regarding daily life adjustments might be effective in promoting a willingness to go studying abroad.

Pirfenidone suppresses polarization to M2 phenotype macrophages and the fibrogenic activity of rat lung fibroblasts.

Pirfenidone is a representative medication to treat interstitial pulmonary fibrosis. Researchers reported pirfenidone (>100 µg/ml) significantly suppressed fibroblast growth in vitro. However, clinically, the maximum concentration of pirfenidone in the blood is approximately 10 µg/ml. We hypothesized there might be an additional mechanism of pirfenidone to fibroblasts indirectly. Macrophages are known to control the activation of fibroblasts via the regulation of inflammatory M1 and suppressive M2 polarization. The aim of this study was to investigate the effects of pirfenidone on alveolar macrophage polarization. Rat alveolar macrophages (NR8383) were stimulated in vitro with lipopolysaccharide (LPS) + interferon (IFN)-γ, or interleukin (IL)-4 + IL-13. Expression of M1 and M2 markers and supernatant's levels of TGF-ß1 were assessed after pirfenidone treatment (0-100 µg/ml). Treatment with LPS + INF-γ or IL-4 + IL-13 significantly increased the expression of M1 and M2 markers, respectively. In macrophage polarization assays, pirfenidone significantly reduced the expression of M2 markers at concentrations greater than 10 µg/ml but had no effect on the expression of M1 markers. At these concentrations, pirfenidone significantly reduced TGF-ß1 levels in NR8383 culture supernatants. In rat lung fibroblasts treated with NR8383 culture supernatants, pirfenidone significantly suppressed proliferation, and the collagen mRNA and protein levels. In conclusion, our results demonstrated that pirfenidone suppressed polarization to M2 macrophages at clinically relevant concentrations and suppressed the rat lung fibroblasts fibrogenic activity.

Carbon monoxide-releasing molecule, CORM-3, modulates alveolar macrophage M1/M2 phenotype in vitro.

Alveolar macrophages are key contributors to both the promotion and resolution of inflammation in the lung and are categorized into pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes. The change in M1/M2 balance has been reported in various pulmonary diseases and is a target for therapeutic intervention. The aim of this study was to assess the modulation of M1/M2 phenotype in alveolar macrophages by water-soluble carbon monoxide-releasing molecule-3 (CORM-3). Rat alveolar macrophages (AM) (NR8383) in culture were stimulated with LPS (5 ng/ml)/IFN-γ (10 U/ml) or IL-4 (10 ng/ml)/IL-13 (10 ng/ml) to induce M1 and M2 phenotypes, respectively. Expression of M1 phenotype markers, iNOS and TNF-α, and M2 phenotype markers, CD206 and Ym-1, was assessed by western blotting after 1, 3, 6, or 24 h in the absence or presence of CORM-3 (0.15 mM) treatment. Inactive CORM-3 (iCORM-3) was used as a control. Treatment of naïve (unstimulated) AM with CORM-3 promoted progression of the M2 phenotype as evidenced by the increased expression of CD206 (at 1 h; 1.8-fold) and Ym-1 (at 3 h; 1.9-fold), respectively. Surprisingly, CORM-3 treatment also upregulated the expression of iNOS protein as assessed 6 h following stimulation of AM with CORM-3 (2.6-fold). On the contrary, CORM-3 effectively reduced LPS/IFN-γ-induced expression of iNOS protein (0.6-fold); however, it had no effect on TNF-α expression. Finally, CORM-3 acutely (1-3 h) upregulated CD206 (1.4-fold) and Ym-1 (1.6-fold) levels in IL-4-/IL-13-treated (M2-stimulus) macrophages. These findings indicate that CORM-3 modulates macrophage M1 and M2 phenotypes in vitro with respect to continuous suppression of iNOS expression in M1-polarized macrophages and transient (early-phase) upregulation of CD206 and Ym-1 proteins in M2-polarized macrophages.

F-spondin inhibits differentiation of clastic precursors via lipoprotein receptor-related protein 8 (LRP8).

BACKGROUND: F-spondin, known to be a secreted neuronal glycoprotein, is highly expressed on the tooth root surface. The authors previously reported that F-spondin is one of the specific markers of cementoblasts in periodontal tissue. In chronic periodontitis, significant cemental resorption rarely occurs on the root side, although alveolar bone resorption by osteoclasts is one of the major pathologic changes. Thus, it was hypothesized that secretory F-spondin from cementoblasts might be involved in differentiation of clastic cells on the root surface. The authors studied effects of secretory F-spondin from F-spondin-expressing cells and its pathway on receptor activator of nuclear factor-κB ligand (RANKL)-mediated differentiation of clastic cells. METHODS: Osteoclast precursors were used in this study. With a chamber assay, the authors examined effects of secretory molecules from F-spondin-expressing cells of transgenic mice on RANKL-induced clastic cell differentiation. RESULTS: Secretory molecules from F-spondin-overexpressing cells significantly inhibited the RANKL-mediated tartrate-resistant acid phosphatase (TRAP)-positive cells from primary progenitor cells with the chamber system. F-spondin suppressed RANKL-mediated nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1); TRAP; cathepsin K; and dendritic cell-specific transmembrane protein (DC-STAMP) expression in the cells. The suppressive effect of F-spondin on RANKL-induced differentiation of clastic cells was partially blocked by knockdown of low-density lipoprotein receptor-related protein 8 (LRP8). CONCLUSIONS: These findings indicate that secretory factors from F-spondin-expressing cells, including F-spondin, downregulate differentiation of clastic precursors. Moreover, F-spondin inhibits RANKL-mediated differentiation of clastic cells partially via LRP8. It is suggested that secretory F-spondin may act protectively from cemental resorption partially via LRP8 in periodontal tissue.

A proposed core curriculum for dental English education in Japan.

BACKGROUND: Globalization of the professions has become a necessity among schools and universities across the world. It has affected the medical and dental professions in terms of curriculum design and student and patient needs. In Japan, where medicine and dentistry are taught mainly in the Japanese language, profession-based courses in English, known as Medical English and Dental English, have been integrated into the existing curriculum among its 83 medical and 29 dental schools. Unfortunately, there is neither a core curriculum nor a model syllabus for these courses. METHODS: This report is based on a survey, two discussion forums, a workshop, and finally, the drafting of a proposed core curriculum for dental English approved by consensus of the participants from each university. RESULTS: The core curriculum covers the theoretical aspects, including dental English terms and oral pathologies; and practical aspects, including blended learning and dentist-patient communication. It is divided into modules and is recommended to be offered for at least two semesters. CONCLUSIONS: The core curriculum is expected to guide curriculum developers in schools where dental English courses are yet to be offered or are still in their early development. It may also serve as a model curriculum to medical and dental schools in countries in Asia, Europe, Africa, and Central and South America, where English is not the medium of instruction.

Pulmonary sequestration presenting elevated CA19-9 and CA125 with ovarian cysts.

A 41-year-old woman was evaluated because of elevated serum levels of the tumor markers CA19-9 and CA125. Whole-body examination revealed an intralobar pulmonary sequestration in the right lower lobe and bilateral cystic ovarian tumors (right: 20 mm, left: 60 mm in diameter, respectively). The left ovarian cyst was resected and diagnosed as an endometrioma. The right ovarian cyst was preserved because of its small size. However, the tumor marker levels remained elevated postoperatively. S10 segmentectomy of the right lung was subsequently performed. Immunohistochemical examination of the sequestrated lung demonstrated positive staining for CA19-9 in the bronchial and alveolar epithelia and mucus. After the pulmonary resection, the CA19-9 and CA125 levels decreased to their normal ranges.

Hepatocellular carcinoma in Child-Pugh C cirrhosis: prognostic factors and survival benefit of nontransplant treatments.

A retrospective multicenter study was conducted to clarify the survival benefit of nontransplant treatments for patients with hepatocellular carcinoma (HCC) associated with Child-Pugh C cirrhosis. Data on 436 patients, including 203 treated patients with HCC, were collected from 20 institutions in Japan. Cox's proportional hazards model corrected for bias by propensity score analysis clearly showed the following as significant independent prognostic factors, including all four nontransplant treatments examined: transarterial chemoembolization, hepatic arterial infusion chemotherapy, percutaneous ethanol injection therapy, radiofrequency ablation, hepatitis B virus, number of tumors, log α-fetoprotein, encephalopathy, ascites and prothrombin time. The cumulative survival rate was significantly higher in the treated group than in the untreated group. The present findings suggest that prognosis can be improved by nontransplant treatments in patients with low Child-Pugh scores. Since this study was retrospective, the possibility of selection bias cannot be ruled out. Therefore, verification by a prospective controlled study is warranted.

Intraoperative mechanical and chemical pleurodesis with 50 % glucose solution for secondary spontaneous pneumothorax in patients with pulmonary emphysema.

PURPOSE: Secondary spontaneous pneumothorax is life-threatening for patients with pulmonary emphysema. To prevent recurrence, intraoperative pleurodesis is performed in addition to bullectomy. We report the therapeutic process and effectiveness of adding mechanical plus chemical pleurodesis, with a 50 % glucose solution, to bullectomy, for patients with pulmonary emphysema-related pneumothorax. METHODS: The subjects were 20 patients (19 men and 1 woman; mean age 68 years) with pulmonary emphysema-related pneumothorax. After bullectomy was completed, 500 mL of a 50 % glucose solution was injected into the pleural cavity, followed by mechanical pleurodesis performed via ablation of the parietal pleura. RESULTS: The volume of pleural effusion decreased on postoperative day (POD) 1, and the temperature decreased on POD 2. The blood sugar levels increased on the day of surgery but decreased on POD 1. The mean postoperative follow-up period was 521 days. One patient died of pneumonia on POD 24. All other patients survived without pneumothorax recurrence. CONCLUSIONS: These results demonstrated the effectiveness of our treatment process for pulmonary emphysema-related pneumothorax. The fact that no patient experienced pneumothorax recurrence suggests that mechanical and chemical pleurodesis with 50 % glucose solution might be effective prophylaxis.