Oral melanoma: a multicenter study of 69 patients from Japan.

OBJECTIVES: The purpose of this multicenter retrospective study was to investigate the demographic characteristics and treatment outcomes of patients with mucosal malignant melanoma (MM) of the oral cavity. MATERIALS AND METHODS: This was a multicenter study involving 8 Japanese universities. The medical records of 69 patients who were diagnosed with primary oral MM between January 2000 and December 2020 were retrospectively analyzed. Overall survival (OS) and prognostic factors for OS were analyzed statistically. RESULTS: There were 40 (58.0%) males and 29 (42.0%) females, and their mean (range) age was 69.8 ± 14.6 (22-96) years old. The most common primary site was the palate (30 patients, 43.5%). Stage IVA was the most common disease stage (36 patients, 52.2%). Radical therapy was performed in 55 patients (79.7%). The 2-year and 5-year OS rates of the 69 patients were 64.6% and 42.5%, respectively. The 2-year and 5-year OS rates of the stage III patients were 85.9% and 72.5%, respectively, and those of the stage IVA patients were 56.3% and 26.0%, respectively. The 1-year OS rate of the stage IVB/IVC patients was 26.7%. The 2-year and 5-year OS rates of the radical therapy group were 74.1% and 50.5%, respectively, whereas the 2-year OS rate of the non-radical therapy group was 26.0%. An advanced T classification was the only identified prognostic factor for OS (hazard ratio: 6.312, 95% confidence interval: 1.133-38.522, p < 0.05). CONCLUSIONS: Early detection and radical treatment are essential for improving the prognosis of oral MM patients. CLINICAL RELEVANCE: Early detection and adequate radical therapy leads to the better prognosis of oral MM patients.

Relationship between dry mouth and hypertension.

OBJECTIVES: Salivary dysfunction, such as reduced salivary flow and an altered salivary composition, is caused by several diseases, medical conditions, and medications. The purpose of the present study was to clarify the relationship between hypertension and morphological changes in the submandibular glands. MATERIALS AND METHODS: An epidemiological study was conducted to elucidate the relationship between hypertension and dry mouth. The effects of hypertension on morphological changes and the intima thickness of arteries in the submandibular glands were histopathologically investigated. RESULTS: Among 1933 subjects in the epidemiological study, 155 (8.0%) had dry mouth. A multivariate analysis revealed that dry mouth correlated with age (p < 0.001), sex (p < 0.001), and hypertension (p < 0.05). No significant differences were observed in the size of the submandibular glands between patients with or without hypertension. The average area of acinar cells was smaller in patients with than in those without hypertension (0.366 ± 0.153 vs. 0.465 ± 0.178, p < 0.05). The arteriosclerotic index was significantly higher in patients with than in those without hypertension (0.304 ± 0.034 vs 0.475 ± 0.053, p < 0.05). CONCLUSIONS: Hypertension may contribute to the degeneration of the submandibular glands by decreasing the number of acinar cells and promoting fatty infiltration and stenosis of the arteries. CLINICAL RELEVANCE: There may be a correlation between hypertension and the degeneration of the submandibular glands by decreasing the number of acinar cells and promoting fatty infiltration and stenosis of the arteries.

Interspecific Difference in Seed Dispersal Characteristics between Japanese Macaques (Macaca fuscata) and Sympatric Japanese Martens (Martes melampus).

We compared the characteristics of seeds within faeces between semi-terrestrial Japanese macaques (Macaca fuscata) and sympatric arboreal Japanese martens (Martes melampus) in Shiga Heights, central Japan. We collected faecal samples of the two mammalian species for 1 year (n = 229 for macaques and n = 22 for martens). We then compared the proportion of seed occurrence, life-form composition, number of seeds and species richness within single faecal samples, and the seed intact ratio between the two mammalian species. We detected seeds from 20 and 7 species from macaque and marten faeces, respectively. Macaque faeces contained seeds of multiple strata, while marten faeces contained no herbaceous plant seeds. Seed sizes within faeces showed no interspecific difference. For macaques, seeds were found within faecal samples collected in late spring to late fall, while for martens, seeds were found between summer and winter. The proportion of seed occurrence was greater in summer (both species) and fall (macaques), which implied that the seed dispersal roles of macaques and martens was greater in these seasons. The mean seed number (across species), intact ratio of seeds (high for both species) and seed species richness within single faecal samples of macaques and martens showed no significant differences, but for several species, martens defecated more seeds than macaques and showed higher intact ratio. Our study indicates that sympatric mammals in the temperate regions of Japan contribute differently to seed dispersal in forest ecosystems.

Human mobility and infection from Covid-19 in the Osaka metropolitan area.

Controlling human mobility is thought to be an effective measure to prevent the spread of the COVID-19 pandemic. This study aims to clarify the human mobility types that impacted the number of COVID-19 cases during the medium-term COVID-19 pandemic in the Osaka metropolitan area. The method used in this study was analysis of the statistical relationship between human mobility changes and the total number of COVID-19 cases after two weeks. In conclusion, the results indicate that it is essential to control the human mobility of groceries/pharmacies to between -5 and 5% and that of parks to more than -20%. The most significant finding for urban sustainability is that urban transit was not found to be a source of infection. Hence governments in cities around the world may be able to encourage communities to return to transit mobility, if they are able to follow the kind of hygiene processes conducted in Osaka.

Time series cross-correlation between home range and number of infected people during the COVID-19 pandemic in a suburban city.

Control of human mobility is one of the most effective measures to prevent the spread of coronavirus disease 2019 (COVID-19). However, the imposition of emergency restrictions had significant negative impacts on citizens' daily lives. As vaccination progresses, we need to consider more effective measures to control the spread of the infection. The research question of this study is as follows: Does the control of home range correlate with a reduction in the number of infected people during the COVID-19 pandemic? This study aims to clarify the correlation between home range and the number of people infected with SARS-CoV-2 during the COVID-19 pandemic in Ibaraki City. Home ranges are analyzed by the Minimum Convex Polygon method using mobile phone GPS location history data. We analyzed the time series cross-correlation between home range lengths and the number of infected people. Results reveal a slight positive correlation between home range and the number of infected people after one week during the COVID-19 pandemic. Regarding home range length, the cross-correlation coefficient is 0.4030 even at a lag level of six weeks, which has the most significant coefficient. Thus, a decrease in the home range is a weak factor correlated with a reduction in the number of infected people. This study makes a significant contribution to the literature by evaluating key public health challenges from the perspective of controliing the spread of the COVID-19 infectuion. Its findings has implications for policy makers, practitioners, and urban scientists seeking to promote urban sustainability.

Prevalence of and risk factors for postoperative complications after lower third molar extraction: A multicenter prospective observational study in Japan.

Lower third molar extraction is the most common surgical treatment among routine dental and oral surgical procedures. while the surgical procedures for lower third molar extraction are well established, the difficulty of tooth extraction and the frequency of postoperative complications differ depending on the patient's background. To establish a management protocol for the lower third molars, the prevalence of and risk factors for postoperative complications after lower third molar extraction were investigated in a large number of Japanese patients in a multicenter prospective study. During 6 consecutive months in 2020, 1826 lower third molar extractions were performed at the 20 participating institutions. The medical records of the patients were reviewed, and relevant data were extracted. The prevalence of and risk factors for postoperative complications were analyzed. The prevalence of postoperative complications after lower third molar extraction was 10.0%. Multivariate analysis indicated that age (≤32 vs >32, odds ratio [OR]: 1.428, 95% confidence interval [95% CI]: 1.040-1.962, P < .05), the radiographic anatomical relationship between the tooth roots and mandibular canal (overlapping of the roots and canal vs no close anatomical relationship between the roots and the superior border of the canal, OR: 2.078, 95% CI: 1.333-3.238, P < .01; overlapping of the roots and canal vs roots impinging on the superior border of the canal, OR: 1.599, 95% CI: 1.050-2.435, P < .05), and impaction depth according to the Pell and Gregory classification (position C vs position A, OR: 3.7622, 95% CI: 2.079-6.310, P < .001; position C vs position B, OR: 2.574, 95% CI: 1.574-4.210, P < .001) are significant independent risk factors for postoperative complications after lower third molar extraction. These results suggested that higher age and a deeply impacted tooth might be significant independent risk factors for postoperative complications after lower third molar extraction.