Rapid repair of human disease-specific single-nucleotide variants by One-SHOT genome editing.

Many human diseases ranging from cancer to hereditary disorders are caused by single-nucleotide mutations in critical genes. Repairing these mutations would significantly improve the quality of life for patients with hereditary diseases. However, current procedures for repairing deleterious single-nucleotide mutations are not straightforward, requiring multiple steps and taking several months to complete. In the current study, we aimed to repair pathogenic allele-specific single-nucleotide mutations using a single round of genome editing. Using high-fidelity, site-specific nuclease AsCas12a/Cpf1, we attempted to repair pathogenic single-nucleotide variants (SNVs) in disease-specific induced pluripotent stem cells. As a result, we achieved repair of the Met918Thr SNV in human oncogene RET with the inclusion of a single-nucleotide marker, followed by absolute markerless, scarless repair of the RET SNV with no detected off-target effects. The markerless method was then confirmed in human type VII collagen-encoding gene COL7A1. Thus, using this One-SHOT method, we successfully reduced the number of genetic manipulations required for genome repair from two consecutive events to one, resulting in allele-specific repair that can be completed within 3 weeks, with or without a single-nucleotide marker. Our findings suggest that One-SHOT can be used to repair other types of mutations, with potential beyond human medicine.

Five-year follow-up study of the association between periodontal disease and myocardial infarction among Japanese male workers: MY Health Up Study.

BACKGROUND: An association between chronic oral infections and coronary heart disease has been suggested. METHODS: The study participants were male employees aged 36-59 years. Data were extracted from the MY Health Up Study, comprising a baseline questionnaire survey and succeeding annual health examinations for financial firm workers in Japan. Using a self-administered questionnaire at baseline, participants' oral status was classified into three types of periodontal indicators: (i) periodontal score, (ii) periodontitis and (iii) tooth loss (<5 and ≥5 teeth). An incidence of myocardial infarction (MI) was determined by annual health examination records. RESULTS: Of the 4037 candidates for follow-up in the baseline year of 2004, 3081 males were eligible for the analysis, 17 of whom experienced MI in the subsequent 5 years. The periodontal score model was associated with an increase in developing MI [odds ratio (OR) = 2.11, 95% confidence interval (CI) = 1.29-3.44], after adjusting for other confounding variables. The periodontitis (OR = 2.26, 95% CI = 0.84-6.02) and tooth loss (OR = 1.97, 95% CI = 0.71-5.45) models showed similar trends, although the difference was not significant. CONCLUSIONS: Periodontal disease may be a mild but independent risk factor for MI among Japanese male workers.

Geographical distributions of physicians in Japan and US: Impact of healthcare system on physician dispersal pattern.

OBJECTIVES: This study examined the effect of increased physician numbers overall on the geographic distribution of the physicians in Japan and the US. METHODS: Equity of physician distribution with reference to community population and community income was evaluated in all municipalities in Japan, and all counties in the US. RESULTS: Between 1980 and 2005, Japan and the US experienced a 55% and 47% increase in the number of physicians per unit population, respectively. The Gini coefficients against population were at similar values between Japan and the US, and have been almost unchanged in the past 25 years in both countries. The Gini coefficient against income in the US was lower than the coefficient in Japan, and the US value has decreased since 1980. Correlation between physician-to-population ratio and per capita income among the communities was stronger in the US than in Japan and has increasingly been strengthened during the period examined. CONCLUSIONS: In spite of constant growth of physician numbers, physicians do not diffuse according to population distribution in both countries. Rather, US physicians seem to diffuse according to income distribution. In order to reverse the continuing maldistribution of physicians, political intervention is required in both countries.

Physician scarcity is a predictor of further scarcity in US, and a predictor of concentration in Japan.

OBJECTIVES: To assess the effects of geographic diffusion of physicians from medically oversupplied toward undersupplied areas driven by economic competition among physicians and political interventions in Japan and US. METHODS: A quantitative evaluation of physician workforce changes at the community level between 1980 and 2005, using municipality-based (Japan) and county-based (US) census data. RESULTS: The overall number of physicians per 100,000 population (physician-to-population ratio: PPR) increased from 130 to 203 in Japan and 158 to 234 in US. In this context, a higher proportion (30.1%) of the quintile communities with lowest PPRs in 1980 has further decreased their PPRs in US than in Japan (21.6% in 2005). In multivariate analysis low PPR was a positive predictor of PPR decrease in the US communities (odds ratio 1.26; 95% confidence interval 1.01-1.58), while it was a negative predictor in Japanese communities (0.69; 0.57-0.83). CONCLUSIONS: Physician scarcity is associated with further scarcity in US communities, while scarcity is associated with recovery from scarcity in Japanese communities. Competition-based physician diffusion strategies and various interventions to address the maldistribution of physicians apparently have not worked effectively in US compared with Japan.

Community characteristics that attract physicians in Japan: a cross-sectional analysis of community demographic and economic factors.

BACKGROUND: In many countries, there is a surplus of physicians in some communities and a shortage in others. Population size is known to be correlated with the number of physicians in a community, and is conventionally considered to represent the power of communities to attract physicians. However, associations between other demographic/economic variables and the number of physicians in a community have not been fully evaluated. This study seeks other parameters that correlate with the physician population and show which characteristics of a community determine its "attractiveness" to physicians. METHODS: Associations between the number of physicians and selected demographic/economic/life-related variables of all of Japan's 3132 municipalities were examined. In order to exclude the confounding effect of community size, correlations between the physician-to-population ratio and other variable-to-population ratios or variable-to-area ratios were evaluated with simple correlation and multiple regression analyses. The equity of physician distribution against each variable was evaluated by the orenz curve and Gini index. RESULTS: Among the 21 variables selected, the service industry workers-to-population ratio (0.543), commercial land price (0.527), sales of goods per person (0.472), and daytime population density (0.451) were better correlated with the physician-to-population ratio than was population density (0.409). Multiple regression analysis showed that the service industry worker-to-population ratio, the daytime population density, and the elderly rate were each independently correlated with the physician-to-population ratio (standardized regression coefficient 0.393, 0.355, 0.089 respectively; each p<0.001). Equity of physician distribution was higher against service industry population (Gini index=0.26) and daytime population (0.28) than against population (0.33). CONCLUSION: Daytime population and service industry population in a municipality are better parameters of community attractiveness to physicians than population. Because attractiveness is supposed to consist of medical demand and the amenities of urban life, the two parameters may represent the amount of medical demand and/or the extent of urban amenities of the community more precisely than population does. The conventional demand-supply analysis based solely on population as the demand parameter may overestimate the inequity of the physician distribution among communities.