Community-level group sports participation and all-cause, cardiovascular disease, and cancer mortality: a 7-year longitudinal study

BACKGROUND

Community-level group sports participation is a structural aspect of social capital that can potentially impact individual health in a contextual manner. This study aimed to investigate contextual relationship between the community-level prevalence of group sports participation and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality in older adults.

METHODS

In this 7-year longitudinal cohort study, data from the Japan Gerontological Evaluation Study, a nationwide survey encompassing 43,088 functionally independent older adults residing in 311 communities, were used. Cause of death data were derived from the Japanese governmental agency, The Ministry of Health, Labour and Welfare, for secondary use. "Participation" was defined as engaging in group sports for one or more days per month. To analyze the data, a two-level survival analysis was employed, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Among the participants, 5,711 (13.3%) deaths were identified, with 1,311 related to CVD and 2,349 to cancer. The average group sports participation rate was 28.3% (range, 10.0-52.7%). After adjusting for individual-level group sports participation and potential confounders, a higher community-level group sports participation rate was found to be significantly associated with a lower risk of both all-cause mortality (HR: 0.89, 95% CI: 0.83-0.95) and cancer mortality (HR: 0.89, 95% CI: 0.81-0.98) for every 10% point increase in the participation rate. For CVD mortality, the association became less significant in the model adjusted for all covariates (HR: 0.94, 95% CI: 0.82-1.09).

CONCLUSIONS

Our findings support the existence of a preventive relationship between community-level group sports participation and the occurrence of all-cause and cancer mortality among older individuals. Promoting group sports within communities holds promise as an effective population-based strategy for extending life expectancy, regardless of individual participation in these groups.

Do changes in the frailty score differ by the type of group sports and exercises participated in? A 3-year longitudinal study

BACKGROUND

Older adults who engage in group sports and exercises achieve greater health benefits than those who exercise by themselves. The benefits of group participation may vary depending on the type of sports/exercise they engage in. The present study aimed to identify the association between specific sports and exercise types performed in groups and evaluate the longitudinal changes in multidimensional frailty scores among community-dwelling older adults in Japan.

METHODS

We used 3-year follow-up data from the Japan Gerontological Evaluation Study and analyzed 33,746 men and 36,799 women aged ≥ 65 years. To elucidate the relationship between participation in 20 types of group sports/exercises in 2016 (baseline) and the change in frailty score (using the Kihon Checklist, KCL) from 2016 to 2019, we performed linear regression analyses through multivariate adjustments for age group, self-rated health, marital status, living alone, occupational status, years of education, alcohol drinking status, smoking status, equivalent income, and disease status using an inverse probability weighting method. P < 0.05 was considered statistically significant.

RESULTS

The mean change in KCL scores over 3 years was + 0.62 and + 0.61 points in men and women, respectively, implying the degree of frailty worsened. The sports/exercise types that significantly prevented increments in KCL scores for both sexes compared to non-participants were hiking (men: B, - 0.36; women: B, - 0.29), walking (men: B, - 0.26; women: B, - 0.24), tennis (men: B, - 0.23; women: B, - 0.24), ground golf (men: B, - 0.21; women: B, - 0.19), and weight exercises (men: B, - 0.19; women: B, - 0.16).

CONCLUSION

Participation in specific sports and exercise groups offer significant physical and psychological benefits for frailty prevention among older adults in Japan. The results of this study may offer substantive evidence to encourage older adults to participate in group activities for the prevention of multidimensional frailty. It will also help public health stakeholders to decide which type of sports and exercise groups to promote in a community.

Association between the telecommuting environment and somatic symptoms among teleworkers in Japan

OBJECTIVES

This study aimed to clarify the association between telecommuting environments and somatic symptoms among teleworkers in Japan.

METHODS

This cross-sectional study, conducted from September 27 to October 29, 2021, used data from the Japan COVID-19 and Society Internet Survey (JACSIS study) in Japan. Of the 31 000 male and female respondents, who were Japanese residents aged 15-79 years and were randomly selected from the panel members of an internet survey company, 4569 home-based teleworkers were finally included in the analysis; 26 431 respondents who met the exclusion criteria were excluded. The analysis included 4 cut-offs (≥4, 8, 12, and 16 points) for somatic symptoms on the Somatic Symptom Scale-8 as objective variables, and the telecommuting environment, such as having adequate desk light and a quiet environment, as explanatory variables. Adjusted Poisson regression analysis was conducted using demographic variables as covariates.

RESULTS

The prevalence ratio (PR) for somatic symptoms increased significantly as the number of poor telecommuting conditions increased, regardless of the cut-off value for somatic symptoms or the frequency of teleworking. In the telecommuting environment, the PR for somatic symptoms was significantly higher for the following 6 items: poor teleworking space to concentrate, inadequate foot space, poor communication environment, poor space for relaxation, noise, and inappropriate temperature and humidity.

CONCLUSIONS

These results suggest that for home-based teleworkers, the more inadequate the telecommuting environment, especially in the aforementioned 6 areas, the higher the likelihood of somatic symptoms. Improving these environments may be useful in preventing various somatic symptoms.

What digital health technology types are used in mental health prevention and intervention? Review of systematic reviews for systematization of technologies

Digital health technology has been widely applied to mental health interventions worldwide. Using digital phenotyping to identify an individual's mental health status has become particularly important. However, many technologies other than digital phenotyping are expected to become more prevalent in the future. The systematization of these technologies is necessary to accurately identify trends in mental health interventions. However, no consensus on the technical classification of digital health technologies for mental health interventions has emerged. Thus, we conducted a review of systematic review articles on the application of digital health technologies in mental health while attempting to systematize the technology using the Delphi method. To identify technologies used in digital phenotyping and other digital technologies, we included 4 systematic review articles that met the inclusion criteria, and an additional 8 review articles, using a snowballing approach, were incorporated into the comprehensive review. Based on the review results, experts from various disciplines participated in the Delphi process and agreed on the following 11 technical categories for mental health interventions: heart rate estimation, exercise or physical activity, sleep estimation, contactless heart rate/pulse wave estimation, voice and emotion analysis, self-care/cognitive behavioral therapy/mindfulness, dietary management, psychological safety, communication robots, avatar/metaverse devices, and brain wave devices. The categories we defined intentionally included technologies that are expected to become widely used in the future. Therefore, we believe these 11 categories are socially implementable and useful for mental health interventions.

[Current issues related to education in the five core disciplines of public health at the school of public health in a private university]

Objectives　In Japan, schools of public health (SPH) have engaged in professional education focusing on five core disciplines: epidemiology, biostatistics, social and behavioral science, health policy and management, and occupational and environmental health. However, empirical information is lacking regarding the current state of this education and its associated challenges in Japan. In this article, we showcase this issue, using the master of public health (MPH) course at Teikyo University Graduate School of Public Health (Teikyo SPH) as an example.Methods　We summarized the current objectives and classes required to complete the MPH course at Teikyo SPH, using the course guideline published in 2022. Current issues and possible future directions in the course were summarized based on the opinions of Teikyo SPH faculty members.Results　For epidemiology, lectures and exercises were designed to focus on how to formulating public health issues, collecting and evaluating data, and causal inference. Issues related to the design included ensuring that students had the necessary skills to apply epidemiology to emerging issues, and catching the course up with evolving techniques. For biostatistics, lectures and exercise classes focused on understanding data and statistics, as well as performing analyses. Issues included the understanding of theories, setting the course level, and a lack of appropriate education materials for emerging analytical methods. For social and behavioral science, lectures and exercise classes focused on understanding human behaviors and actions for problem solving. Issues included learning various behavioral theories in a limited timeframe, the gap between the lectures and various needs, and nurturing professionals who had the skills to perform in practical settings. For health policy and management, lectures, exercise classes, and practical training classes focused on identifying and solving problems in the community and around the world, and on integrating the disparate viewpoints of health economics and policy. Issues included few alumni who actually found work globally, a lack of students working in local or central administrations, and insufficient perspectives on rational/economic thinking and macro-economic transitions. For occupational and environmental health, lectures, exercise classes, and practical training classes focused on learning the occupational and environmental impacts of public health issues, and their countermeasures. Challenges included enriching the topics with regard to advanced technologies, environmental health, and socially vulnerable populations.Conclusion　Through these reflections on MPH education at Teikyo SPH, the following recommendations are considered essential in order to prepare improvements to the program: reorganizing the curriculum to meet the needs of the day, accepting students with various backgrounds, addressing the increasing knowledge and skills that need to be acquired by the students, and enhancing the powers of professors to implement changes.

[A cross-sectional study of physical activity promotion projects and organizational factors in the workplace]

OBJECTIVE

The benefits of physical activity are well-recognized but physical activity promotion projects (PAPP) are not well implemented in workplaces, resulting in an evidence-practice gap. This study identified the organizational factors associated with PAPP in the workplace in Japan.

METHODS

A self-administered questionnaire survey was postal mailed to 3,266 listed companies (with ≥ 50 employees) in Japan. The items surveyed included the presence or absence of PAPP and 29 organizational factors. Organizational factors were also extracted from interviews with corporate health managers. The Consolidated Framework for Implementation Research (CFIR) was applied. Multiple logistic regression analysis was conducted with the presence or absence of PAPP as the objective variable, each quartile group (Q1-Q4) of the total number of relevant organizational factors as the explanatory variable, and the basic workplace attributes as the covariate.

RESULTS

The analysis covered 301 workplaces. Of these, 98 (32.6%) had implemented PAPP. The adjusted odds ratio for PAPP for each group based on Q1 was 1.88 (0.62-5.70) for Q2, 3.38 (1.21-9.43) for Q3, and 29.69 (9.95-88.59) for Q4. The association between each organizational factor and PAPP was high for the constructs in the 'inner setting' of the CFIR. The observed adjusted odds ratios for these items were: 'there is a precedent for PAPP' 12.50 (6.42-24.34), 'there is a budget for the health department' 10.36 (5.24-20.47), 'understanding of the health department manager' 8.41 (4.43-15.99), 'understanding of workplace management' 7.63 (4.16-14.02), 'employee 7.31 (3.42-15.64), and 'requests from employees' 7.31 (3.42-15.64).

CONCLUSION

There was a quantity-response relationship between the number of applicable organizational factors and PAPP. It has been suggested that the expansion of organizational factors may lead to PAPP. In particular, the creation of an internal atmosphere and the promotion of understanding among the people concerned may be useful.

Frequency of social participation by types and functional decline: A six-year longitudinal study

Social participation is effective for preventing functional decline in older people. However, researchers have not fully explored how different frequencies of social participation by type. We aimed to clarify the relationship between the frequency of social participation by type and functional decline. We used data from the Japan Gerontological Evaluation Study, which consists of individuals aged 65 years and older who were not eligible to receive public long-term-care insurance benefits. From 13 municipalities, 51,968 respondents who met the criteria were included in the analysis. We used a sex-stratified Cox proportional hazards model. The outcome was the new incidence of functional decline during a six-year follow-up, and the exposure was the frequency of social participation of one of the following six types: sports, hobbies, volunteering, neighborhood, senior clubs, and industry groups. The frequency was categorized as "never," "a few times a year," "once or twice a month," and "once a week or more." We set non-participation in each activity as the reference, and we adjusted for 12 potential confounders (i.e., sociodemographic and health-related factors). After we adjusted for confounders, participation in sports and hobbies once or twice a month, once a week or more was protectively associated with functional decline. We found a similar association for participation in neighborhood a few times a year. Our findings demonstrate the importance of considering the effects of different types and frequencies of activities when promoting social participation among older people as part of public health policies.

[Report: Symposium "Fostering the Power to Open Up the Future and Collaboration among Academic Societies in the Field of Social Medicine: How to Promote and Support the Activities of Young Scientists"]

The recruitment and training of early-career researchers are important for the development of science, especially in countries with low birth rates, such as Japan. In several academic societies for social medicine, early-career researchers have formed associations for the purposes of networking and career development. However, to date, little information about the activities of these associations has been shared. Therefore, we organized a symposium at the 93rd Annual Meeting of the Japanese Society for Hygiene (March 4, 2023) to introduce the early-career researcher associations that have been formed within five academic societies namely the Japanese Society for Hygiene, Japan Epidemiological Association, Japan Society for Occupational Health, Japan Society for Medical Education, and Japan Society for Healthcare Administration. In this paper, we summarize the activities, challenges, and future prospects of each association and their strategies for future development and collaboration on the basis of presentations and discussions at the symposium.

Association of social participation (including inconsistent participation) with the progression of frailty among older adults: Community-based cohort study in Japan

AIM

This study examined the relationship between continuity of social participation and progression of frailty among community-dwelling older adults, by baseline frailty level.

METHODS

This study was part of a 3-year community-based cohort study among adults aged ≥65 years, living independently in a rural municipality in Japan. Mail surveys were carried out in 2016, 2018 and 2019. This study involved 2799 participants who responded to the question about social participation in every survey. Frailty was evaluated by Kihon Checklist total scores. Social participation was categorized into consistent non-participation, interrupted recent non-participation, interrupted recent participation and consistent participation. We assessed the relationship between social participation and change in frailty scores using general linear regression analysis, stratifying the participants into groups by their frailty level at baseline.

RESULTS

There was a smaller frailty score increase in the robust (β -0.61, 95% CI -0.99 to -0.22) and prefrail groups (β -0.73, 95% CI -1.18 to -0.27) for consistent participation than consistent non-participation. Interrupted recent participation showed significant suppression in the prefrail group (β -0.96, 95% CI -1.60 to -0.32). Social participation had no clear effect on progression in the frail group.

CONCLUSIONS

Consistent social participation might reduce the progression of frailty in robust and prefrail people. Inconsistent participation might also help to reduce progression in prefrail older adults. It is important for prefrail older adults to return to their social activities and continue to engage as long as possible, even if their participation was intermittent in the past. Geriatr Gerontol Int 2023; 23: 25-31.

[Correlates of walking time by exercise stage of change in older adults in Japan: The 2019 JAGES cross-sectional study]

Objectives　Some older adults less interested in exercise may still meet the walking time of 30 minutes or more per day that is required to maintain and improve their health. This study aimed to clarify the characteristics of those who walk for 30 minutes or more per day stratified by the exercise stage of change.Methods　This cross-sectional study used a self-administered mail survey conducted by the Japan Gerontological Evaluation Study (JAGES) in 2019. There were 45,939 participants, aged 65 years or above, who were not certified as requiring long-term care and who resided in 62 municipalities in 24 prefectures. The measures included daily walking time, stage of change for exercise (20 minutes or more once a week), and factors related to physical activities (eight demographic and biological; three psychological, cognitive, and emotional; eight behavioral; 40 social and cultural; and three environmental factors). The analysis was stratified into three groups according to the transformation stages: 1) pre-contemplation, 2) contemplation/preparation, and 3) action/maintenance. Poisson regression analysis was conducted with the dependent variable as walking time, the independent variables as physical activity factors, and the covariates as all eight demographic and biological factors.Results　Of the 24,146 survey respondents (52.6% response rate), 18,464 were included in the analysis. Surveys with missing items that were important for the analysis and patients who needed care and assistance were excluded. The factors that were significantly associated with walking 30 minutes or more per day only in the pre-contemplation stage, or only in the precontemplation and the contemplation/preparation stages, were three demographic and biological (married; age 80 years or above and non-independence of instrumental activities of daily living were negatively associated), two behavioral (going out at least once a week and watching sports on TV or the Internet), and six social and cultural factors (provision of instrumental support, frequency of meeting with friends more than once a week, participation in the neighborhood association, high reciprocity, reading habits; playing Go was negatively associated).Conclusions　Among the demographic and biological factors, and the behavioral, social, and cultural factors, 11 items were found to be associated with walking 30 minutes or more per day only in the pre-contemplation stage, or only in the precontemplation and contemplation/preparation stages. To promote walking even in the lower stages of change, it may be useful to promote exchanges with others, rather than focusing predominantly on physical activities.

Types of Sports and Exercise Group Participation and Sociopsychological Health in Older Adults: A 3-Yr Longitudinal Study

PURPOSE

This study aimed to identify the association between a specific sports type and exercise group participation and longitudinal changes in sociopsychological health among community-dwelling older adults.

METHODS

Three years of data from the Japan Gerontological Evaluation Study were used, comprising a total of 33,746 men and 36,799 women age ≥65 yr. To determine the relationship between 20 types of sports and exercise group participation in 2016 (baseline) and changes in depressive symptoms (Geriatric Depression Scale (GDS-15)), self-rated health (4-point scale), subjective well-being (11-point scale), and frequency of laughter (days per month) from 2016 to 2019, we performed linear regression analyses with conducting a multivariate adjustment for potential confounders using an inverse probability weighting method.

RESULTS

The mean changes over 3 yr were +0.32 and +0.28 in GDS-15, -0.06 and -0.05 in self-rated health, -0.08 and -0.06 in subjective well-being, and -1.21 and -1.19 in frequency of laughter, in men and women, respectively. Men playing golf in a group were more likely to suppress an increase in the GDS-15 ( B = -0.11, 95% confidence interval, -0.18 to -0.05) and decreases in self-rated health (0.04, 0.02 to 0.06), subjective well-being (0.07, 0.02 to 0.12), and frequency of laughter (0.45, 0.11 to 0.80). Women participating in walking, weight exercises, and hiking groups were more likely to prevent an increase in the GDS-15 (-0.12, -0.19 to -0.04; -0.09, -0.18 to -0.01; and -0.16, -0.30 to -0.03, respectively) and decreases in self-rated health (0.03, 0.01 to 0.05; 0.03, 0.01 to 0.06; and 0.08, 0.04 to 0.12, respectively).

CONCLUSIONS

Golf in older men and walking, weight exercises, and hiking in older women could be recommended as an effective program for promoting sociopsychological health among older adults in Japan.

Social participation and change in walking time among older adults: a 3-year longitudinal study from the JAGES

BACKGROUND

Among all physical activities, walking is one of the easiest and most economical activities for older adults' mental and physical health. Although promoting social participation may extend the walking time of older adults, the longitudinal relationship is not well understood. Thus, this study elucidates the relationship between nine types of social participation and change in walking time during a 3-year follow-up of older adults.

METHODS

We conducted a 3-year community-based longitudinal study of independent older adults in Japan. From the 2016 and 2019 surveys, we extracted 57,042 individuals. We performed multiple regression analyses, estimating associations between change in walking time after three years and nine types of social participation in 2016: volunteer, sports, hobby, senior, neighborhood, learning, health, skills, and paid work. We conducted subgroup analysis stratified by walking time in 2016 (i.e., < 60 or ≥ 60 min/day).

RESULTS

The mean (standard deviation) change in walking time for 3 years was - 4.04 (29.4) min/day. After adjusting potential confounders, the significant predictors of increasing or maintaining walking time (min/day) were participation in paid work (+ 3.02) in the < 60 min/day subgroup; and volunteer (+ 2.15), sports (+ 2.89), hobby (+ 1.71), senior (+ 1.27), neighborhood (+ 1.70), learning (+ 1.65), health (+ 1.74), and skills (+ 1.95) in the ≥ 60 min/day subgroup compared with non-participants.

CONCLUSIONS

Paid work and community activities may be effective for maintaining or increasing walking time among older adults with less (< 60 min/day) and sufficient (≥ 60 min/day) walking time, respectively.

Correlates of engaging in sports and exercise volunteering among older adults in Japan

This study aimed to identify factors associated with engaging in sports and exercise volunteering among older adults. We used cross-sectional data from the Japan Gerontological Evaluation Study (JAGES), a nationwide mail survey of 20,877 older adults from 60 municipalities. Multilevel mixed-effects logistic regression analysis was used to investigate the correlation between engaging in sports and exercise volunteering and 39 variables classified into five factors: (1) demographic and biological, (2) behavioral, (3) psychological, cognitive, and emotional, (4) social and cultural, and (5) environmental factors. Among the analyzed samples, 1580 (7.6%) participants volunteered a few times/year or more often. Factors that showed positive association with the volunteering were older age, a current drinking habit, excellent self-rated health, high proportion of sports group participants in a living area, low municipal population density, and rich social and cultural features (i.e., social cohesion, support, network, and participation). Meanwhile, those that had a negative association were women, low level of education, deteriorated instrumental activities of daily living, having a past or current smoking habit, poor self-rated health, and depressive symptoms. We clarified the characteristics of the population that is more likely to participate in sports and exercise volunteering as well as those of the population that is less likely to participate and requires support.

Estimating the Impact of Sustained Social Participation on Depressive Symptoms in Older Adults

BACKGROUND

Social participation has been suggested as a means to prevent depressive symptoms. However, it remains unclear whether a one-time boost suffices or whether participation needs to be sustained over time for long-term prevention. We estimated the impacts of alternative hypothetical interventions in social participation on subsequent depressive symptoms among older adults.

METHODS

Data were from a nationwide prospective cohort study of Japanese older adults ≥65 years of age (n = 32,748). We analyzed social participation (1) as a baseline exposure from 2010 (approximating a one-time boost intervention) and (2) as a time-varying exposure from 2010 and 2013 (approximating a sustained intervention). We defined binary depressive symptoms in 2016 using the Geriatric Depression Scale. We used the doubly robust targeted maximum likelihood estimation to address time-dependent confounding.

RESULTS

The magnitude of the association between sustained participation and the lower prevalence of depressive symptoms was larger than the association observed for baseline participation only (e.g., prevalence ratio [PR] for participation in any activity = 0.83 [95% confidence interval = 0.79, 0.88] vs. 0.90 [0.87, 0.94]). For activities with a lower proportion of consistent participation over time (e.g., senior clubs), there was little evidence of an association between baseline participation and subsequent depressive symptoms, while an association for sustained participation was evident (e.g., PR for senior clubs = 0.96 [0.90, 1.02] vs. 0.88 [0.79, 0.97]). Participation at baseline but withholding participation in 2013 was not associated with subsequent depressive symptoms.

CONCLUSIONS

Sustained social participation may be more strongly associated with fewer depressive symptoms among older adults.

Impact of various intensities and frequencies of non-occupational physical activity on the risk of dementia among physically independent older adults: the Japan Gerontological Evaluation Study

OBJECTIVES

The aim of this study was to investigate the association between different intensities and frequencies of non-occupational physical activity (PA) and the risk of dementia among Japanese older adults.

STUDY DESIGN

This was a prospective cohort study.

METHODS

A total of 2194 participants aged ≥65 years from the Japan Gerontological Evaluation Study were followed up between 2010 and 2016. The standardised dementia scale of the long-term care insurance system was used to identify incident dementia, whereas non-occupational PA (<2 or ≥2 times/week on each intensity: light, moderate and vigorous) was assessed using a questionnaire. Cox regression was used to compute the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia.

RESULTS

After adjustment for sociodemographic and medical characteristics, the following frequencies and intensities of non-occupational PA, compared with no non-occupational PA at all, were associated with a reduced risk of dementia: light PA ≥2 times/week (HR = 0.61, 95% CI: 0.38-0.97), moderate PA <2 times/week (HR = 0.46, 95% CI: 0.28-0.76), moderate PA ≥2 times/week (HR = 0.57, 95% CI: 0.36-0.91), vigorous PA <2 times/week (HR = 0.40, 95% CI: 0.21-0.74) and vigorous PA ≥2 times/week (HR = 0.29, 95% CI: 0.15-0.57). In the sex-specific analysis, moderate PA <2 times/week and vigorous PA ≥2 times/week were associated with a reduced risk of dementia in men, whereas light and moderate PA ≥2 times/week and all frequencies of vigorous PA were associated with a reduced risk of dementia in women.

CONCLUSIONS

Practicing non-occupational PA was associated with a reduced risk of dementia among Japanese older adults.

Watching sports and depressive symptoms among older adults: a cross-sectional study from the JAGES 2019 survey

The current study investigated the relationship between the frequency of watching sports and depressive symptoms among older adults. This study used cross-sectional data from the Japan Gerontological Evaluation Study, a nationwide mail survey of 21,317 older adults. Depressive symptoms were defined as a Geriatric Depression Scale score of ≥ 5. Participants were queried regarding the average frequency at which they watched sports on-site and via TV/Internet over the past year. Among the 21,317 participants, 4559 (21.4%) had depressive symptoms, while 4808 (22.6%) and 16,576 (77.8%) watched sports on-site and via TV/Internet at least once a year, respectively. Older adults who watched sports on-site a few times/year (prevalence ratio, 0.70; 95% confidence interval, 0.65-0.74) or 1-3 times/month (0.66, 0.53-0.82) were less likely to have depressive symptoms compared to non-spectators after adjusting for frequency of playing sports, exercise activities, and other potential confounders. Meanwhile, a dose-response relationship was confirmed for watching via TV/Internet (prevalence ratio of 0.86, 0.79, and 0.71 for a few times/year, 1-3 times/month, and ≥ 1 time/week, respectively). This study suggested that watching sports on-site or via TV/Internet, regardless of whether they regularly engage in sports, may reduce the risk of depressive symptoms among older adults.

Community-Level Sports Group Participation and Health Behaviors Among Older Non-Participants in a Sports Group: A Multilevel Cross-Sectional Study

This study validates the relationship between community-level sports group participation and the frequency of leaving the house and transtheoretical model stages of behavior change for exercise among older individuals who did not participate in a sports group. We used cross-sectional data from the 2016 Japan Gerontological Evaluation Study. The proportion of sports group participants at the community level was calculated using the data from 157,233 older individuals living in 1000 communities. We conducted a multilevel regression analysis to examine the relationship between the proportion of sports group participants and the frequency of leaving the house (1 day/week or less) and the transtheoretical model stages of behavior change for exercise. A statistically significant relationship was observed between a high prevalence of sports group participation and lower risk of homeboundness (odds ratio: 0.94) and high transtheoretical model stages (partial regression coefficient: 0.06) as estimated by 10 percentage points of participation proportion. Older individuals, even those not participating in a sports group, living in a community with a high prevalence of sports group participation are less likely to be homebound; they are highly interested and have numerous opportunities to engage in exercise.

Social participation and mortality according to company size of the longest-held job among older men in Japan: A 6-year follow-up study from the JAGES

OBJECTIVES

The purpose of this study was to examine the relationship between social participation (type/pattern) and mortality according to company size of the longest-held job among older men in Japan who have worked in the company.

METHODS

Longitudinal data from the Japan Gerontological Evaluation Study were used in this study. Functionally independent individuals aged 65 years and older in Japan were surveyed. Work and community organizations (local community, hobbies, and sports) were used as social participation. A Cox proportional hazards model was used to calculate mortality hazard ratios.

RESULTS

Analysis was carried out on 19 260 participants. A total of 2870 deaths occurred during the 6-year follow-up period. Those in companies with 49 or fewer employees had the highest prevalence of work participation and the lowest participation in any community organization. Regardless of company size, the mortality risk was significantly lower for participants in any social participation (eg, the hazard ratio for participation in a hobby organization among those with a company size of 49 employees or fewer was 0.74, 95% CI: 0.65-0.85) compared to nonparticipants whose company size was 49 or fewer employees.

CONCLUSIONS

In Japan, although older men who have worked for small companies may have fewer benefits, their social participation may reduce their mortality risks. To avoid increasing health inequalities, it is necessary to create an environment in which they are more likely to participate in social activities.

Community-Level Sports Group Participation and the Risk of Cognitive Impairment

PURPOSE

Community-level group participation is a structural aspect of social capital that may have a contextual influence on individual health. We investigated the contextual effect of community-level prevalence of sports group participation on the risk of cognitive impairment among older individuals.

METHODS

We analyzed prospective cohort data from the Japan Gerontological Evaluation Study, a nationwide survey of 40,308 functionally independent older individuals from 346 communities. Cognitive impairment was assessed by the nationally standardized dementia scale proposed by the Ministry of Health, Labour and Welfare of Japan. Participation in a sports group 1 d per month or more frequently was defined as "participation." We applied a two-level multilevel survival analysis to calculate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

The cumulative incidence of cognitive impairment during the 6-yr follow-up period was 9.8%. The mean proportion of sports group participation was 25.2% (range, 0.0%-56.5%). Higher prevalence of community-level sports group participation was associated with a lower risk of cognitive impairment (HR, 0.92; 95% CI, 0.86-0.99, estimated by 10 percentage points of participation proportion) after adjusting for individual-level sports group participation, sex, age, disease, obesity, social isolation, alcohol, smoking, education, income, depression, daily walking time, population density, and sunlight hours. We found cross-level interaction between individual- and community-level sports group participation (HR, 0.87; 95% CI, 0.76-0.99).

CONCLUSIONS

We found a contextual preventive effect of community-level sports group participation on developing cognitive impairment among older individuals. Furthermore, the benefit may favor sports group participants. Therefore, promoting sports groups in a community setting may be effective as a population-based strategy for the prevention of dementia.

Size of company of the longest-held job and mortality in older Japanese adults: A 6-year follow-up study from the Japan Gerontological Evaluation Study

OBJECTIVES

Very few longitudinal studies have investigated the question of whether differences in company size may give rise to health inequalities. The aim of this study was to examine the relationship between company size of the longest-held job and mortality in older Japanese adults.

METHODS

This study used longitudinal data from the Japan Gerontological Evaluation Study. Surveys were sent to functionally independent individuals aged 65 or older who were randomly sampled from 13 municipalities in Japan. Respondents were followed for a maximum of 6.6 years. The Cox proportional hazards model was used to calculate mortality hazard ratios (HRs) for men and for women. Analysis was carried out on 35 418 participants (197 514 person-years).

RESULTS

A total of 3935 deaths occurred during the 6-year follow-up period. Among men, in Model 1 that adjusted for age, educational attainment, type of longest-held job, and municipalities, mortality HRs decreased significantly with increasing size of company (P for trend = .002). Compared to companies with 1-9 employees, the mortality HR (0.78, 95% confidence interval: 0.68-0.90) was significantly lower for companies with 10 000 or more employees. However, there were no significant differences among women (P for trend = .41).

CONCLUSIONS

In men, mortality in old age may decrease with increasing size of company of the longest-held job. To reduce health inequalities in old age due to differences in size of company, studies should be conducted to determine the underlying mechanisms and moderating factors and those findings should be reflected in labor policies and occupational health systems.

Specific types of sports and exercise group participation and socio-psychological health in older people

Older people who engage in sports and exercise in a group render greater benefits for socio-psychological aspects compared to exercising alone. The aim of this study was to identify the prevalence of specific types of sports and exercise groups and the association with self-rated health, depressive symptoms, and frequency of laughter among community-dwelling older people. We used cross-sectional data from the 2016 Japan Gerontological Evaluation Study and analysed 63,465 males and 68,497 females aged ≥65 years. The top three most popular types among males were golf (11.3%), walking (8.4%), and ground golf (6.3%). Among females, the top three were fitness exercises (13.8%), walking (8.3%), and weight exercises (6.2%). After adjusting for potential confounders, engaging in golf with a group was significantly related with excellent self-rated health (prevalence ratio, PR, 1.31 in male and 1.78 in female), low depressive symptoms (PR, 0.70 and 0.71), and a high frequency of laughter (PR, 1.12 and 1.13). Among females, walking displayed a significant relationship with all three characteristics (PR, 1.23, 0.79, and 1.06, respectively). Golf in older males and walking in older females might be the first choice for an effective programme to spread sports and exercise groups within the older Japanese community.

Community-level Sports Group Participation and Older Individuals' Depressive Symptoms

Purpose

Community-level group participation is a structural aspect of social capital that may have a contextual influence on an individual’s health. Herein, we sought to investigate a contextual relationship between community-level prevalence of sports group participation and depressive symptoms in older individuals.

Methods

We used data from the 2010 Japan Gerontological Evaluation Study, a population-based, cross-sectional study of individuals 65 yr or older without long-term care needs in Japan. Overall, 74,681 participants in 516 communities were analyzed. Depressive symptoms were diagnosed as a 15-item Geriatric Depression Scale score of ≥5. Participation in a sports group 1 d·month⁻¹ or more often was defined as “participation.” For this study, we applied two-level multilevel Poisson regression analysis stratified by sex, calculated prevalence ratios (PR), and 95% confidence intervals (CI).

Results

Overall, 17,420 individuals (23.3%) had depressive symptoms, and 16,915 (22.6%) participated in a sports group. Higher prevalence of community-level sports group participation had a statistically significant relationship with a lower likelihood of depressive symptoms (male: PR, 0.89 (95% CI, 0.85–0.92); female: PR, 0.96 (95% CI, 0.92–0.99), estimated by 10% of participation proportion) after adjusting for individual-level sports group participation, age, diseases, family form, alcohol, smoking, education, equivalent income, and population density. We found statistically significant cross-level interaction terms in male participants only (PR, 0.86; 95% CI, 0.77–0.95).

Conclusions

We found a contextual preventive relationship between community-level sports group participation and depressive symptoms in older individuals. Therefore, promoting sports groups in a community may be effective as a population-based strategy for the prevention of depression in older individuals. Furthermore, the benefit may favor male sports group participants.

An additive effect of leading role in the organization between social participation and dementia onset among Japanese older adults: the AGES cohort study

Background

Several previous studies reported social participation may reduce the incident of dementia; therefore, the type of positions held in the organization may relate to dementia onset. However, this hypothesis remains largely unknown. The purpose of the present study was to examine the additive effect of a leadership position in the organization on dementia onset and social participation among elderly people in a local community, according to data from a Japanese older adults cohort study.

Methods

Of 29,374 community-dwelling elderly, a total of 15,313 subjects responded to the baseline survey and were followed-up from November 2003 to March 2013. To evaluate the association between dementia onset and social participation as well as the role in the organization, we conducted Cox proportional hazard regression analysis with multiple imputation by age group (aged 75 years older or younger). The dependent variable was dementia onset, which was obtained from long-term care insurance data in Japan; independent variables were social participation and the role in the organization to which they belonged (head, manager, or treasurer). Covariates were sex, age, educational level, marriage status, job status, residence status, alcohol consumption, smoking status, and walking time, instrumental activities of daily living, depression, and medical history.

Results

During the follow-up period, 708 young-old elderly people (7.7%) and 1289 old-old elderly people (27.9%) developed dementia. In young-old elderly, relative to social non-participants, adjusted Hazard Ratio (HR) for dementia onset for participants (regular members + leadership positions) was 0.75 (95% confidence interval (CI), 0.64–0.88). Relative to regular members, adjusted HR for dementia onset for non-participants was 1.22 (95% CI, 1.02–1.46), for leadership positions 0.81 (95% CI, 0.65–0.99). The results for old-old elderly participants did not show that any significantly adjusted HR between dementia onset and social participation, the role in the organization.

Conclusions

In young-old elderly people, social participation might have a positive effect on dementia onset, and holding leadership positions in organization could lead to a decrease in risk of dementia onset by almost 20% than regular members.

Electronic supplementary material

The online version of this article (10.1186/s12877-017-0688-9) contains supplementary material, which is available to authorized users.

Correlates of Regular Participation in Sports Groups among Japanese Older Adults: JAGES Cross-Sectional Study

Background

Participation in a sports group is key for the prevention of incident functional disability. Little is known about the correlates of older adults’ participation in sports groups, although this could assist with the development of effective health strategies. The purpose of this study was to identify the demographic and biological, psychosocial, behavioral, social and cultural, and environmental correlates of sports group participation among Japanese older adults.

Methods

Data were obtained from the Japan Gerontological Evaluation study, which was a population–based cohort of people aged ≥65 years without disability enrolled from 31 municipalities across Japan (n = 78,002). Poisson regression analysis was used to determine the associations between the factors and participation in sports groups.

Results

Non-regular participation in sports groups was associated with lower educational level, being employed, and working the longest in the agricultural/forestry/fishery industry among the demographic and biological factors and poor self-rated health and depression among the psychosocial factors. Of the behavioral factors, current smoking was negatively associated and current drinking was positively associated with regular participation in sports groups. Among the social and cultural factors, having emotional social support and participating in hobby clubs, senior citizen clubs, or volunteer groups were associated with a high prevalence of participation in sports groups. Perceptions of the presence of parks or sidewalks, good access to shops, and good accessibility to facilities were positively associated with participation in sports groups among the environmental factors.

Conclusions

Our study suggests that the promotion of activities that could increase older adults’ participation in sports groups should consider a broad range of demographic and biological, psychosocial, behavioral, social and cultural, and environmental factors. Although future longitudinal studies to elucidate the causal associations are needed, encouraging participation in community groups through social networks might be effective for participation in sports groups.

[The association between the presence of occupational health nurses at Japanese worksites and health promotion activities]

OBJECTIVES

The purpose of this study was to determine the association between the presence of occupational health nurses and health promotion activities, relative to the number of employees, and the health promotion policies of the companies.

METHODS

We investigated 3,266 companies with at least 50 employees listed on the Tokyo Stock Exchange. Questionnaires were sent by mail, and employees in charge of health management or promotion were asked about health promotion activities at their own worksites. Logistic regression analysis was performed with each type of health promotion activity (nutrition, exercise, sleep, mental health, smoking cessation, alcohol consumption reduction, and oral health) as dependent variables, and the presence of an occupational health nurse as the independent variable. The results were adjusted for the type of industry, total number of company employees, presence of company health promotion policies, and the presence of an occupational health physician.

RESULTS

Responses were received from 415 companies (response rate: 12.7%). Occupational health nurses were present at 172 companies (41.4%). Health promotion activities such as (in order of frequency) mental health (295 companies, 71.1%), smoking cessation (133, 32.0%), exercise (99, 23.9%), nutrition (75, 18.1%), oral health (49, 11.8%), sleep (39, 9.4%), and alcohol consumption reduction (26, 6.3%) were being conducted. Setting worksites with no occupational health nurse as a reference, the odds ratios of each health promotion activity of a worksite with one or more occupational health nurses were calculated. The odds ratios of mental health (2.43, 95% confidence interval: 1.32-4.48), smoking cessation (3.70, 2.14-6.38), exercise (4.98, 2.65-9.35), nutrition (8.34, 3.86-18.03), oral health (4.25, 1.87-9.62), and alcohol consumption reduction (8.96, 2.24-35.92) were significant. Stratified analysis using the number of worksite employees, 499 or fewer and 500 or more, also showed significantly higher odds ratios of smoking cessation, exercise, and nutrition activities at worksites of both groups. However, the odds ratios were significant for mental health and oral health activities only at worksites with 499 or fewer employees.

CONCLUSIONS

At worksites of listed companies around Japan, those with an occupational health nurse carried out more health promotion activities such as nutrition, exercise, mental health, smoking cessation, alcohol consumption reduction, and oral health than those without, even after adjusting for scale of the company and presence of health promotion policies. This result suggests that the posting of an occupational health nurse to a worksite is associated with the conduct of health promotion activities.

Social participation and the prevention of functional disability in older Japanese: the JAGES cohort study

BACKGROUND

We examined the relationship between incident functional disability and social participation from the perspective of number of types of organizations participated in and type of social participation in a prospective cohort study.

METHOD

The study was based on the Aichi Gerontological Evaluation Study (AGES) Cohort Study data. We followed 13,310 individuals aged 65 years or older for 4 years. Analysis was carried out on 12,951 subjects, excluding 359 people whose information on age or sex was missing. Social participation was categorized into 8 types.

RESULTS

Compared to those that did not participate in any organizations, the hazard ratio (HR) was 0.83 (95% CI: 0.73-0.95) for participation in one, 0.72 (0.61-0.85) for participation in two, and 0.57 (0.46-0.70) for participation in three or more different types of organizations. In multivariable adjusted models, participation in the following types of organization was protective for incident disability: local community organizations (HR = 0.85, 95% CI: 0.76-0.96), hobby organizations (HR = 0.75, 95% CI: 0.64-0.87), and sports organizations (HR = 0.64, 95% CI: 0.54-0.81).

CONCLUSION

Social participation may decrease the risk of incident functional disability in older people in Japan. This effect may be strengthened by participation in a variety of different types of organizations. Participating in a local community, hobby, or sports group or organization may be especially effective for decreasing the risk of disability.

Participation in sports organizations and the prevention of functional disability in older Japanese: the AGES Cohort Study

BACKGROUND

We sought to examine prospectively the difference in the association between incident functional disability and exercise with or without sports organization participation.

METHODS

The study was based on the Aichi Gerontological Evaluation Study (AGES) Cohort Study data. In October 2003, self-reported questionnaires were mailed to 29,374 non-disabled Japanese individuals aged 65 years or older. Of these, 13,310 individuals were introduced to the Study, and they were followed for 4 years. Analysis was carried out on 11,581 subjects who provided all necessary information for the analysis.

RESULTS

Analysis was carried out on incident functional disability by 4 groups of different combinations of performance of exercise and participation in a sports organization Active Participant (AP), Exercise Alone (EA), Passive Participant (PP) and Sedentary (S). Compared to the AP group, the EA group had a hazard ratio (HR) of 1.29 (1.02-1.64) for incident functional disability. No significant difference was seen with the PP group, with an HR of 1.16 (0.76-1.77). When a measure of social networks was added to the covariates, the HR of the EA group dropped to 1.27 (1.00-1.61), and significant differences disappeared. In contrast, it showed hardly any change when social support was added.

CONCLUSION

The results suggested that, even with a regular exercise habit, incident functional disability may be better prevented when a person participates in a sports organization than when he/she does not. In addition, participation in a sports organization correlates positively with social networks, which may lead to a small decrease in incident functional disability.

Gastrin and Helicobacter pylori in low-grade MALT lymphoma patients

BACKGROUND

This study of patients with Helicobacter pylori infection and low-grade MALT lymphoma aimed to investigate: 1) the effect of H. pylori eradication therapy on the serum gastrin level, 2) whether changes of the serum gastrin level after therapy could predict the prognosis of patients with this tumour, and 3) the relationship between the gastric H. pylori load, the serum gastrin level and the status of MALT lymphoma.

METHODS

Thirteen patients with documented low-grade MALT lymphoma and H. pylori infection were enrolled and received H. pylori eradication therapy as the sole initial treatment. The presence of H. pylori, the serum gastrin level, the endoscopic findings, the pathologic features of the biopsies and resected specimens, and the endoscopic ultrasonography findings were evaluated before and after therapy. Follow-up was carried out every 3-6 months.

RESULTS

H. pylori eradication was eventually achieved in all 13 patients. The pretreatment fasting serum gastrin level decreased from 177.1 +/- 107.4 pg/ml to 129.2 +/- 78.1, 96.4 +/- 66.6 and 80.1 +/- 42.7 pg/ml after 0-3, 3-6 and 6-9 months, respectively (all P < 0.05). Successful eradication of H. pylori was followed by a decrease of the fasting serum gastrin level and complete regression of initial low-grade MALT lymphoma was observed in all patients. However, two patients subsequently developed recurrent high-grade MALT lymphoma or high-grade lymphoma. In one of them, the serum gastrin level rose again above the pretreatment value. In the other, however, the fasting gastrin level fell throughout the study period. The median fasting serum gastrin level before H. pylori eradication therapy was higher in the patients with tumours of the gastric body (203.4 +/- 108.9 pg/ml) than in those with tumours of the antrum and angulus (89.3 +/- 28.0 pg/ml) (P = 0.06).

CONCLUSIONS

Hypergastrinaemia may be associated with an increased risk of gastric MALT lymphoma.

Different distribution patterns of the two mannose 6-phosphate receptors in rat liver

Two mannose 6-phosphate receptors, cation-dependent and -independent receptors (CDMPR and CIMPR), play an important role in the intracellular transport of lysosomal enzymes. To investigate functional differences between the two in vivo, their distribution was examined in the rat liver using immunohistochemical techniques. Positive signals corresponding to CIMPR were detected intensely in hepatocytes and weakly in sinusoidal Kupffer cells and interstitial cells in Glisson's capsule. In the liver acinus, hepatocytes in the perivenous region showed a more intense immunoreactivity than those in the periportal region. On the other hand, positive staining of CDMPR was detected at a high level in Kupffer cells, epithelial cells of interlobular bile ducts, and fibroblast-like cells, but the corresponding signal was rather weak in hepatocytes. In situ hybridization analysis also revealed a high level of expression of CIMPR mRNAs in hepatocytes and of CDMPR mRNA in Kupffer cells. By double immunostaining, OX6-positive antigen-presenting cells in Glisson's capsule were co-labeled with the CDMPR signal but were only faintly stained with anti-CIMPR. These different distribution patterns of the two MPRs suggest distinct functional properties of each receptor in liver tissue.

[Clinical and bacteriological features of 12 cases of liver abscess caused by Streptococcus milleri group]

We described the clinical and bacteriological features of 12 cases of liver abscess caused by Streptococcus milleri group (SMG) during a 6-year period from 1993 to 1998. The gender was 11 males and 1 female with their ages ranging from 39 to 76 years old (mean: 53.4). The common symptoms were fever (100%), abdominal pain (67%), and appetite loss (58%). Nine cases had underlying diseases such as carcinomas and diabetes mellitus. Predominant causes of the liver abscess were cryptogenic (42%) and biliary tract disease (33%). Three patients died of an exacerbation of the carcinoma. Eight cases (67%) was single infection of SMG and no mixed infection with anaerobes. No strains isolated in this series showed resistance against penicillin G and ampicillin. SMG was highly isolated from the blood culture in eight of the 11 cases (73%). Liver abscess should be taken into consideration as one of the causes of SMG septicemia.

[Reproductive and developmental toxicity studies of S-1090, cefmatilen hydrochloride hydrate (2)--A study on oral administration during the period of organogenesis in rats]

Cefmatilen hydrochloride hydrate (S-1090) was administered daily by gavage to female rats at doses of 100, 300 or 1000 mg potency/kg/day from Days 7 to 17 of pregnancy to assess its effects on dams and on development of the embryo-fetuses and offspring. Loose or reddish-brown feces were observed in dams of all the S-1090 dosing groups. Body weight gain was increased from the early stage of administration to the end of pregnancy, food consumption was transiently decreased at the early stage of administration, and water consumption was increased from the middle to the end of pregnancy in all the S-1090 dosing groups. However, no effects on pregnancy, parturition and lactation were observed. Necrospy revealed an increased cecum weight in pregnant and lactating dams of all the S-1090 dosing groups. No effects of S-1090 were observed in viability, growth, incidences of external, skeletal and visceral anomalies, and degree of ossification in F1 fetuses. No effects of S-1090 were observed in such parameters as viability, incidence of external and skeletal anomalies, physical development, sensory functions/reflexes, behavior and reproductive function in F1 offspring. No adverse effects were observed in F2 offspring. On the basis of these results, the no observed adverse effect levels of S-1090 are estimated to be less than 100 mg potency/kg/day for maternal general toxicity, 1000 mg potency/kg/day for maternal reproductive toxicity and the developmental toxicity in the embryo-fetuses and offspring under the conditions of the present study.

[Reproductive and developmental toxicity studies of S-1090, cefmatilen hydrochloride hydrate (1)--A study on oral administration prior to and in the early stages of pregnancy in rats]

Cefmatilen hydrochloride hydrate (S-1090) was administered daily by gavage to rats at doses of 100, 300 or 1000 mg potency/kg/day prior to and in the early stage of pregnancy to assess its adverse effects on parental reproductive ability and embryo-fetal development. Loose and/or reddish brown feces were observed in both males and females of all the S-1090 dosing groups, and abdominal distention was also observed in males throughout the dosing period. No drug-related deaths occurred in either males or females. In males, body weight and food consumption were increased at a dose of 1000 mg potency/kg/day throughout the dosing period. In females, body weight gain was restrained during late pregnancy, and food consumption was decreased transiently following the initiation of dosing, and then remained high on the day before parturition in all the S-1090 dosing groups. Necropsy of male and female rats revealed an increase in the cecum weight. The reproductive ability of males and females was normal in all the S-1090 dosing groups. No effects of S-1090 were observed in the implantation ratio, embryo-fetal viability, fetal body weight, and incidence of external, skeletal and visceral anomalies. Based on these results, the no observed adverse effect levels of S-1090 are estimated to be less than 100 mg potency/kg/day for parental general toxicity, 1000 mg potency/kg/day for reproductive toxicity, and 1000 mg potency/kg/day for developmental toxicity in embryo-fetuses under the conditions of the present study.

[Reproductive and developmental toxicity studies of S-1090, cefmatilen hydrochloride hydrate (4)--A study on oral administration during the perinatal and lactation periods in rats]

Cefmatilen hydrochloride hydrate (S-1090) was administered daily by gavage to female rats at doses of 100, 300 or 1000 mg potency/kg/day from Day 17 of pregnancy to Day 20 of lactation to assess its effects on pregnant/lactating females and on development of the offspring. In dams, loose feces/reddish brown feces, increased cecum weight, decreased weights of the heart, spleen and submaxillary gland in all the S-1090 dosing groups and a decreased weight of the thymus in the 1000 mg potency/kg dosing group were observed. However, no effects on parturition and lactation were observed in any of the dosing groups. In F1 offspring, although increased cecum weight was found at weaning in all the S-1090 dosing groups, no abnormalities in viability, physical development, sensory functions/reflexes, behavior and reproductive function were observed. No adverse effects were observed in F2 fetuses and offspring. On the basis of these results, the no observed adverse effect levels of S-1090 are estimated to be less than 100 mg potency/kg/day for maternal general toxicity, and 1000 mg potency/kg/day for maternal reproductive toxicity and for developmental and reproductive toxicity in offspring under the conditions of the present study.

Prevention of apoptosis of mammalian cells by the CED-3-cleaved form of CED-9

CED-9 prevents apoptosis in embryonic cells of Caenorhabditis elegans but not in mammalian cells. We show here that the prevention of apoptosis in mammalian cells requires a CED-3-cleaved form (68-280) of CED-9 which is localized in the inner mitochondrial membrane. The viability of PC12 and HeLa cells was significantly increased after death stimuli when truncated CED-9 was expressed in these cells but full-length CED-9 did not. The truncated CED-9 expressed in these cells was largely localized to the inner mitochondrial and the endoplasmic reticulum membranes, while full-length CED-9 was detected mainly in endoplasmic reticulum fractions. Moreover, truncated CED-9 in purified mitochondria was resistant to trypsin digestion, but full-length CED-9 was not. These results suggest that the CED-3-cleaved form of CED-9 prevents apoptosis in mammalian cells by localizing to the inner mitochondrial membrane.

Impact of neoadjuvant chemotherapy on Ki-67 and PCNA labeling indices for esophageal squamous cell carcinomas

PURPOSE

The effects of neoadjuvant chemotherapy (CT) on Ki-67 and proliferating cell nuclear antigen (PCNA) labeling index (LI) were analyzed, using biopsy and surgical specimens of esophageal cancer.

METHOD AND MATERIALS

Immunohistochemical staining for Ki-67 and PCNA was performed for biopsy and surgical specimens of 35 patients with esophageal squamous cell carcinoma. Seventeen patients were treated with neoadjuvant CT (CT group), while no preoperative treatment was performed for the remaining 18 patients (control group). As neoadjuvant CT, cisplatin of 50 mg/body/week was administered 2-5 times (100-250 mg in total) until 7-10 days before subtotal esophagectomy.

RESULT

Significant correlation between the LIs of biopsy and surgical specimens was observed for the control group (p = 0.006 for Ki-67 and p = 0.005 for PCNA), although both LIs of surgical specimens were significantly higher than those of biopsy specimens (p < 0.05). However, no significant correlation between LIs of biopsy specimens and those of surgical specimens was observed for the CT group. In addition, the LIs of the surgical specimens of the CT group were significantly lower than the LIs of the control group (p < 0.005 for Ki-67 and p < 0.05 for PCNA). Significant decrease in Ki-67 LI after neoadjuvant CT was noted especially for well or moderately differentiated squamous cell carcinomas and/or tumors treated with high-dose cisplatin (150-250 mg).

CONCLUSION

Significant correlation of Ki-67 and PCNA LIs between biopsy and surgical specimens was demonstrated for the control group. Neoadjuvant CT decreased the percentage of cycling and proliferative tumor cells of esophageal cancer.