Multifaceted well-being experienced by community dwelling older adults engaged in volunteering activities of frailty prevention in Japan

AIM

This study aims to elucidate what volunteering activities mean for older adults in Japan by analyzing their emotions and evaluations from hedonic (e.g., happiness), eudaimonic (e.g., self-growth), and social (e.g., social coherence) well-being.

METHODS

The qualitative research was conducted to describe the subjective experience of older adults' volunteering activities (frailty checkups) in the community-setting. Eight older adults were interviewed about their experiences during these activities. The interview data were analyzed from two assumption frameworks: first, three aspects of well-being, and second, timeframes of well-being, during the activity, medium-term, and long-term. Previous studies have not focused on the polysemy or the timeframe of well-being.

RESULTS

Our results showed that hedonic, eudaimonic, and social well-being are not independent, but overlap. Furthermore, even if older adults experience certain emotions at a point of time, they may change in the long term. This implies that it is important to analyze older adults' feelings and experiences from not only one aspect but from different perspectives and measure their feelings not just at a particular moment but in the long term. This is the first empirical study to examine qualitatively the holistic experiences of well-being among older adults who volunteer.

CONCLUSIONS

We conclude that this study is unique in that it attempted to associate empirically the experiences of older adults during volunteering with their general psychological status of well-being. These findings could help make volunteering activities more meaningful for older adults and create or promote an active community. Geriatr Gerontol Int 2024; 24: 273-278.

Association between participation in social network service groups and offline social networks

AIM

Although some previous studies have suggested using a social networking service (SNS) to create and maintain offline social networks among younger generations, whether similar outcomes would apply to middle-aged and older individuals is uncertain. This study aimed to examine the association between participation in groups via SNS and greater offline social networks among middle-aged and older individuals.

METHODS

We conducted a web-based questionnaire survey on 3106 respondents from September to October 2021 among members of "the Shumi-to Club," an SNS in Japan. They indicated the number of SNS groups they belonged to and were classified into two categories, namely, those with and without participation in SNS groups. The current study assessed offline social networks using the total frequency of face-to-face interactions with distant family members and friends. Ordinal logistic regression analyses were performed, and the frequency of offline interactions was set as the outcome with adjustment for sociodemographic variables and self-rated health.

RESULTS

Approximately 70.8% (n = 2200) of the participants belonged to SNS groups. Participation in SNS groups was associated with higher frequencies of face-to-face interaction with friends (odds ratio [95% confidential intervals]: 1.78 [1.53-2.07]). However, the current study found no association between belonging to a group and face-to-face interaction with distant family members (1.09 [0.93-1.26]).

CONCLUSIONS

The participation in SNS groups potentially promotes offline social networks, particularly with friends. Geriatr Gerontol Int 2024; 24: 279-284.

Research Participant Selection Bias in the Workshop Using Socially Assistive Robots for Older Adults and Its Effect on Population Representativeness

Every research participant has their own personality characteristics. For example, older adults assisted by socially assistive robots (SAR) may have their own unique characteristics and may not be representative of the general population of older adults. In this research, we compared the average personality characteristics of participants in a workshop on robotics recruited directly through posting with those of older Japanese adults to examine participant selection bias and group representativeness for future study of SARs. After a one-week recruitment period, the workshop was attended by 20 older participants (nine males and 11 females) aged between 62 and 86 years. Extroversion among workshop participants was 4.38, 0.40 higher than the average for older adults in Japan. The workshop participants' openness was 4.55, 1.09 higher than the average for the Japanese elderly. Thus, the results indicate a slight selection bias in the personal characteristics of the participants depending on the recruitment method when compared to the Japan national average for older adults. In addition, only one of 20 participants was below the cutoff on the LSNS-6 score and considered to have a tendency toward social isolation. The development and introduction of socially assistive robots is often being considered to support people in social isolation in their daily lives; however, the results of this study showed that it is difficult to recruit people who tend to be socially isolated when gathering research participants by methods such as posting. Therefore, the effectiveness of the method of recruiting participants should be carefully verified in research regarding socially assistive robots.

WITHIN- AND BETWEEN-PERSON EFFECTS OF HEALTH AND SOCIAL RELATIONSHIPS WITH FAMILY AND NEIGHBORS ON WELL-BEING

Good health and positive social relationships are significant resources in well-being. However, little is known about how intrapersonal changes and interpersonal differences in health and social relationships are associated with well-being in later life. This study aimed to examine within- and between-person effects of physical health and social relationships with family, friends, and neighbors (social support and companionship) on well-being. We analyzed longitudinal data from a representative sample of older Japanese adults aged 74 to 86 years (N=1388). The results from multilevel models showed that decline in health (intrapersonal changes) was associated with lower well-being. Nevertheless, there was the interaction effect of social relationships with family and neighbors (between-person differences) in the relationship between health and well-being change. Among participants with lower social support from family and neighbors, the negative association between decline of health and well-being was stronger. Conversely, participants with higher social support reported higher well-being regardless of physical health change. Contrastingly, among participants with higher companionship with family and neighbors, participants reported higher well-being at the time of maintaining or increasing physical health. For participants with lower companionship, health change was not associated with well-being. These findings suggest social support has a preventive effect on well-being in the face of declining health, while companionship has a facilitative impact on well-being in good health. The results also suggest relationships with neighbors as well as family play an important role in well-being in very late life.

THE PROTECTIVE EFFECT OF RESILIENCE ON SHRINKAGE OF FRIENDSHIP IN LATER LIFE

The purpose of this study was to examine the protective effect of trait resilience, a positive personality characteristic that enhances individual adaptation to life events and adversity, in the face of declining social relationships in later life. Social relations have a significant effect on our development and well-being throughout life. However, it is known that a decline in physical, cognitive, and mental functioning makes it difficult to maintain active participation in society and leads to shrinking social networks in later life. Therefore, it is important to identify protective factors that enable people to maintain positive social relations when functioning in daily life declines in old age. We analyzed longitudinal survey data from a representative sample of older Japanese adults aged 74 to 86 years (N=1064). The interaction effect of resilience in the relationship between functions (physical, cognitive, and mental) and relationships with friends (social support exchange and companionship) was examined using multi-group Structured Equation Modeling (SEM). Respondents were divided into upper quartile and lower quartile groups according to their Resilience Scale (RS-14) scores. The results showed significant group differences for the effect of cognitive function on friendship. The positive correlation between cognitive functioning and friendship was stronger among respondents with low resilience. For high resilience participants, cognitive functioning was not associated with friendship. The results suggest that resilient older adults cope well with poor cognitive health and maintain positive social relationships in very late life.

DECREASED FREQUENCY OF SMALL TALK DURING COVID-19 PANDEMIC AND MENTAL HEALTH: LONGITUDINAL SURVEYS IN JAPAN

The coronavirus disease 2019 (COVID-19) has drastically reduced opportunities for small talk. As small talk involves socializing, such deprivation can be stressful. This study examined the association between the change in frequency of small talk before and during the pandemic and the mental health of middle-aged and older people. We conducted web-based longitudinal questionnaire surveys from March to May 2020 and from September to October 2021 among members of a Japanese social networking service. We analyzed 867 responses of people who participated in both surveys (mean age, 68.0 ± 8.0 years; men, 68.1%). This study was approved by the Research Ethics Committee of University of Tokyo. Change in small talk frequency before and during the pandemic was assessed using a single item, “Have the opportunities for small talk (including face-to-face, phone, video call, etc.) with someone other than cohabiting family members changed?” We divided the responses into “increase,” “no change,” and “decrease.” Mental health outcomes included psychological well-being and loneliness. A total of 57.0%, 34.4%, and 8.7% reported “decrease,” “no change,” and “increase,” respectively, from before to during the pandemic. After adjusting for potential covariates, multiple regression analyses showed that people who felt their small talk frequency decreased during the pandemic compared to pre-pandemic period had lower psychological well-being and greater loneliness than those who did not. We observed no interaction between change in small talk frequency and age/sex. Our study quantitatively revealed the importance of small talk during the pandemic in maintaining mental health.

Eliciting a User's Preferences by the Self-Disclosure of Socially Assistive Robots in Local Households of Older Adults to Facilitate Verbal Human-Robot Interaction

To realize a society in which older adults can live independently in their homes and familiar environments for as long as possible, their lives can be supported by providing appropriate technology. In this case, a new intervention for older people using socially assistive robots (SARs) is proposed; however, previous research has demonstrated that individual differences exist in the use and response to SAR interventions, and it has also been reported that SARs are not used by users in some cases. Therefore, in this study, we developed a self-disclosure function to promote continuous interaction with robots, using a Japanese corpus and self-disclosure items. In this study, we defined the specific requirements and functions of self-disclosure in SARs and developed ten non-arbitrary speech scripts from the field of social psychology using a Japanese corpus and self-disclosure items. To evaluate the effect of self-disclosure in SARs, an SAR was introduced to each household for 20 days, with the consent of seven community-dwelling older adults. Based on the recorded voice interaction data, we analyzed how the number, total time, and quality of verbal interactions changed with the SAR's self-disclosure. Furthermore, we conducted group interviews with the participants and received positive comments regarding the robot's self-disclosure. Some participants considered the specific personality of the SAR by accumulating its behavioral characteristics. As a consequence, these results indicate that the robot's self-disclosure feature is effective in significantly increasing the quantity and quality of verbal interactions with older adults.

Decreased Frequency of Small Talk Due to the COVID-19 Pandemic Has Deteriorated Mental Health: Findings From Longitudinal Surveys of Middle-Aged and Older People in Japan

The coronavirus disease 2019 (COVID-19) has reduced opportunities for small talk. As small talk involves socializing, such deprivation can be stressful. This study examined the association between the change in the frequency of small talk from before to during the pandemic and the mental health of middle-aged and older people. We obtained data from web-based longitudinal surveys for members of a Japanese social networking service. People who felt their small talk frequency decreased during the pandemic compared with the prepandemic period had lower psychological well-being and greater loneliness than those who did not. Our study quantitatively revealed the importance of small talk during the pandemic in maintaining people's mental health.

Neighborhood Relationship Matters for Whom?: Interaction With Family Structure and Functional Conditions

Living environment is considered to have unignorable effect on our health and well-being, especially when we face shrinkage of mobility as we age. Social interaction with neighbors constitutes our social environment, and it may affect our well-being by interacting with other social resources such as support from family and professional care providers. In this study we examined the effect of social environment in neighborhood on older people’s well-being, and how its effect is moderated by their family structure, functional conditions, and LTC service usage. Data was obtained from the survey conducted in 2012 with nationally representative sample of Japanese adults aged 60 years and older. The results showed that for people with functional limitation but were not certified as needing LTC, neighborhood social network was positively associated with well-being. These results suggest the unique function of neighbors for frail people to keep everyday life in the community.

Transition to Widowhood: Trajectories of Depressive Symptomatology Among Japanese Older Adults

Spousal loss is one of the most consequential negative life events for the surviving partners. While there is abundant research on mental health and well-being of widows, most of these studies rely on the post-bereavement data. In this study, we use the data from the National Survey of Japanese Elderly (NSJE), which is a publicly available longitudinal data set collected from Japanese adults aged 60 years and older. The current study uses the first seven waves of data from 1987 to 2006, where participants were followed every three to four years. Using the NSJE advances our understanding of the bereavement process as it allows us to observe the levels and trajectories of depressive symptom before, during, and after the loss of their spouses. In our analyses, we selected 522 participants (average age at bereavement: 75.0 years; 27% male) who experienced spousal loss at some point during the seven waves. We examined the trajectories of depressive symptoms assessed using CES-D as these participants transition to widowhood. The results showed a small significant increase in depressive symptoms leading up to the time of the loss. There was also a significant increase in symptoms at the time of the loss, but we did not observe any decline in symptoms after the loss. In addition, we found that their age at bereavement significantly moderated the pattern, such that the increase in depressive symptoms at the time of the loss was attenuated for older participants. The implications of these findings will be discussed.

Retirement and Social Activities in Japan: Does Age Moderate the Association?

Although retirement age is increasing in aging societies, its impact on individuals and communities is unclear. This study examined how age moderates the linkage between transition into retirement and participation in productive and non-productive social activities after retirement, using a nationwide longitudinal survey with a probability sample of Japanese aged 60 and over (n = 3,493). Multinomial logistic regression analyses were performed to predict changes in volunteering and hobbies/learning during 3-5 years of follow-up and their participation level at the follow-up. The significant interactions between change in work status (remained working as reference, full/partial retirement, remained not-working) and age at baseline showed that fully retired persons were more likely to increase these activities than remained workers only when they retired by their early seventies. Thus it is important to encourage engagement in social activities before retirement and remove psychological and environmental barriers that hinder starting new activities at old age.

Societal Need for Interdisciplinary Ageing Research: An International Alliance of Research Universities "Ageing, Longevity and Health" Stream (IARU-ALH) Position Statement

Ageing is a global concern with major social, health, and economic implications. While individual countries seek to develop responses to immediate, pressing needs, international attention and collaboration is required to most effectively address the multifaceted challenges and opportunities an ageing global population presents in the longer term. The Ageing, Longevity and Health stream of the International Alliance of Research Universities (IARU-ALH) was built on a solid foundation of first-class interdisciplinary research and on innovative outreach and communication centres. This interdisciplinary network conducts projects that span biology, medicine, social sciences, epidemiology, public health, policy, and demography, and actively engages with the public and other societal stakeholders. Here we posit that such international interdisciplinary networks are needed and uniquely placed to address major challenges related to health and ageing and ultimately will produce new understanding and knowledge to promote the awareness of healthy ageing and encourage societal change via novel, science-informed interventions. Global interdisciplinary research presents great potential and opportunities to accelerate our understanding of human ageing and to produce new, more effective solutions to a pressing, complex problem. However, more focused, strategic efforts and investments are required in order to deliver on these potentials and reap maximum benefits for individuals and societies. IARU-ALH members are determined to contribute, in collaboration with others, to delivering on this vision.

Physical and Social Neighborhood Environments and Well-Being

Existing research has found effects of neighborhood environment on well-being. However, it is still not clear what features of neighborhood environments affect well-being for older adults and whether the impact of the environment varies depending on the health and economic conditions. In this study, we examined the relations between 4 physical and social neighborhood-context factors, that is, the availability of neighborhood physical resources (e.g. community centers and libraries), the walkability and accessibility, the availability of social resources (e.g. culture and recreation programs, and social care services), and the social inclusion (e.g. participation in decision making, and positive social attitude toward older adults), and individual-level well-being. Moreover, we examined the health and economic disparities of effect of neighborhood environments on well-being. We used data from locally representative longitudinal study of older Japanese aged 74 to 86 (N = 1388). Results from multi-level linear regression showed that after controlling individual variables having inhibitory/facilitatory effects of well-being, the availability of physical resources was associated with higher well-being score. Especially among older adults who had financial strains, the availability of physical environment had a positive effect on well-being more strongly. For older adults who had better physical functions, accessibility and walkability were associated with higher well-being score. The social inclusiveness was associated with higher well-being score among those who had no financial strain. These important findings demonstrate the need for more research exploring the underlying mechanisms. The potential benefits of this approach provide a basis for developing models of maintaining well-being for older adults.

Companionship With Family, Friends, and Neighbors in Later Life

Companionship with close others are known to have a significant positive effect on our well-being in later years of life. At the same time, it is known that the frequency of meeting and chatting with others, an indicator of companionship, declines as we age. In this study we explore the situation of companionship among older-old and oldest-old people. The focus of this study on understanding how the aging process affects the experience of companionship and how people adapt to the loss of companionship. Semi-structured, in-depth interviews with 43 people aged 75 and older living in urban communities in Kawasaki, Japan. Participants were asked about everyday interactions with close others and feelings they experienced at the time. Interviews were transcribed and analyzed qualitatively. Chatting, going out for lunch or dinner, and going shopping were examples of activities older Japanese enjoyed with close others. Almost all respondents mentioned the loss of their old friends and siblings. They also mentioned that the decline in their physical and cognitive health, as well as that of their companions hindered shared activities they used to enjoy. They cherished positive interactions with others, although the frequency declined. Some respondents intentionally made new companions in the physical proximity, but it was hard to compensate for the loss of old companions with new one. These findings suggest that the value of companionship remains or even increase as we age. It would be important to identify environmental or social factors that may prevent the loss of companionship among older adults.

PHYSICAL AND SOCIAL ACTIVITIES AND COGNITIVE CHANGES AMONG OLD-OLD ADULTS: RESULTS FROM 3-YEAR FOLLOW-UP PERIOD

The association between activity engagement and late-life cognitive function is considered to depend on the characteristics of the activity, the cognitive processes it involves, and the life stage of participants. A better understanding of this association is required to comprehend cognitive function in old age. The present study examined the association between baseline activity engagement and cognitive changes across a 3-year period among old-old adults. We extracted data for 873 Japanese community-dwelling participants from data of the Keio-Kawasaki Aging Study. We assessed cognitive performance thrice (at baseline, 1.5-year follow-up, and 3-year follow-up) using a short version of the Mini-Mental Status Examination. For the subsequent analyses, we used three measures of cognitive function: total score, orientation, and concentration, which showed diverse individual differences. We measured the frequency of physical activity and social group participation at baseline. Using conditional latent growth curve models, we examined which baseline activity was associated with the three measures of cognitive function over 3 years. Greater physical activity was significantly related to higher rate of orientation, after adjusting for age and education (β = −.261, p < .001). Social activity was significantly related to rates of higher total cognitive score (β = −.276, p < .001) and higher orientation (β = −.207, p < .001). These findings suggest that the association between activity engagement and late-life cognitive function among old-old adults varies by activity type and cognitive domain.

THE PHYSICAL AND SOCIAL ENVIRONMENTS, SOCIAL ACTIVITIES, AND SUBJECTIVE WELL-BEING: FINDINGS FROM THE K2 STUDY

It has been pointed that the environments effect subjective well-being(SWB). However, it is still not clear what aspects of environments effect SWB among older adults and if degree on physical condition of older adults cause the difference on relations between and environments and SWB. In this study, firstly, we examined the relationship between the physical and social environments, social activities, and SWB in a sample of older Japanese. Secondly, we examined the differences on the effects of environments on SWB between older adults with lower physical functions and those with higher physical functions. We used data from locally representative longitudinal study of older adults 75±1, 80±1, and 85±1 years of age (at baseline) , which was conducted in Japan (The Keio-Kawasaki Aging Study(K2 study) ; N = 1388). Concerning the environments, we assessed the physical environments (public spaces and buildings, and accessibility) and the social environments (culture and recreation programs, and inclusive social environment). Results from covariance structure analyses showed that the accessible physical environment and the social environments were significant predictors of SWB, and showed that accessibility and the social environments influenced SWB via participation of social activities, too. Moreover, results from multiple group structural equation modeling showed that accessibility was a stronger predictor of SWB among older adults with lower physical functions, while accessibility was not a predictor among older adults with higher physical functions. The potential benefits of this approach provide a basic developing compensation model of SWB for this population of older adults.

Associations between social networks and life satisfaction among older Japanese: Does birth cohort make a difference?

Japanese older people experienced drastic changes in family structure and values after World War II at different life stages by birth cohorts. We examined how linkages between different types of social ties and life satisfaction (LS) vary across cohorts, in conjunction with age and survey year differences. Data from face-to-face interviews conducted in 1987, 1999, and 2012 with a nationally representative sample of older Japanese (N = 4,917) were analyzed. The participants were members of 4 birth cohorts (C1: 1901-1912, C2: 1913-1924, C3: 1925-1936, C4: 1937-1949), categorized into 6 groups based on cohort and age at time of measurement (young-old [YO]: 63-74; old-old [OO]: 75-86): C1OO, C2YO, C2OO, C3YO, C3OO, and C4YO. Effects of social networks on LS among the 6 groups were compared simultaneously and separately by gender using the Amos software. There were significant cohort variations in the linkages between family network and LS. The positive association between being married and LS was stronger for later cohorts (C3, C4) among men, whereas that of co-residence with a child and LS was stronger for the earlier cohorts (C1, C2) among women. Moreover, the positive association between meeting with nonfamily members and LS increased from 1987 to 2012 among women, indicating a period effect over a cohort effect. The effects of being married and participation in community groups on LS also changed with age. Our results suggest that linkages between social relations and LS should be interpreted within the context of individual and social changes over time.

Significant increase in natural-killer T cells in patients with tuberculosis complicated by type 2 diabetes mellitus

This study examined the frequency of Vα24(+)/Vβ11(+) natural-killer T (NKT) cells from peripheral blood and bronchoalveolar lavage fluid in pulmonary tuberculosis (TB) patients with or without diabetes mellitus (DM). The clinical grade of TB was significantly higher among diabetic patients. NKT cells from both peripheral blood and bronchoalveolar lavage were significantly increased in diabetic TB patients compared with non-diabetic TB patients. This may be due to the generally higher bacillary burden in diabetic TB patients. NKT cells from peripheral blood mononuclear cells in TB patients with or without DM were significantly increased, compared with levels in non-TB diabetic patients and healthy controls. The measurement of NKT cells from peripheral blood has the potential to be a reliable, non-invasive, practical diagnostic marker for active TB.

Contextual effect of neighborhood environment on homebound elderly in a Japanese community

Homebound status is associated with poorer health and disability; however, the impact of community factors on the decision to remain homebound is unclear. We applied multilevel analyses to examine the association between neighborhood environment and homebound status among Japanese community-dwelling elderly. A cross-sectional survey was conducted in February 2009 using a mailed questionnaire. A total of 4123 participants aged 20 years and over living in 72 small districts of Kashiwa, Japan, were randomly selected for the survey. Of the 1735 returned questionnaires, the 588 that were completed by individuals aged 65 years and over were used for analysis. Frequency of going outdoors was assessed and respondents going outdoors once a week or less were defined as homebound. Neighborhood environment was assessed using three subscales of the Neighborhood Environment Walkability Scale (NEWS-A) (land use mix-access, aesthetics and crime safety). Multilevel logistic regression analysis indicated that the lower score of land use mix-access at the district level was associated with the elderly being homebound after adjustment for individual demographic data, physical, psychological and social factors and district prevalence of population aged 65 years or more. This finding could contribute to devising a successful community-based strategy for homebound prevention of community-dwelling elderly individuals.

[Re-exploring attitude toward community scale and its relationship to health status among the general population]

OBJECTIVES

In order for community-based health promotion and prevention activities to be effective and efficient, it is important to assess the community consciousness among local residents. The purpose of this study was to review the reliability and validity of the Attitude toward Community Scale (ACS) and examine its association with health status among the general population.

METHODS

A cross-sectional survey was conducted in February 2009 using a mail-in self-administered questionnaire. The target population comprised 4,123 randomly-selected local residents aged 20 years and over living in Kashiwa city, Chiba prefecture, Japan. The questionnaire encompassed the ACS (the wording of some items was modified), an also included data to allow assessment of demographics and health status.

RESULTS

Of 4,123 questionnaires, 1,735 could be analyzed (valid response rate: 42.1%). Confirmatory factor analysis supported the two-factor model of the original scale. The reliability of the scale was verified using the Cronbach's alpha coefficient. All item-total correlations were moderately or strongly positive. Logistic regression showed that a better attitude toward the community was associated with higher self-rated health, less anxiety about the future and less loneliness.

CONCLUSION

Although the original scale was developed in 1978, the ACS still appears applicable for modern research following some wording modifications of the items. In future studies, it will be necessary to clearly establish relationships between health status and community consciousness and to develop methodology for enhancing the latter.

Beijing family Mycobacterium tuberculosis isolated from throughout Japan: phylogeny and genetic features

To estimate the current population genetic structure of Mycobacterium tuberculosis in Japan, phylogenetic traits were analysed for 237 Beijing family strains isolated from tuberculosis patients throughout the country. Unlike previous reports from other countries, the ancient Beijing sublineage was predominant throughout Japan. Clustering analysis based on JATA-VNTR (Japan Anti-Tuberculosis Association variable numbers of tandem repeats), a specialised set of VNTR for the discrimination of Japanese M. tuberculosis strains, revealed high similarity of the modern Beijing sublineage strains, irrespective of their geographic origin. JATA-VNTR might be useful for the phylogenetic classification in populations where ancient Beijing strains are frequently isolated.

Significant reduction of granulomas in Nrf2-deficient mice infected with Mycobacterium tuberculosis

OBJECTIVE

We have reported previously that mice deficient in nuclear erythroid 2 p45-related factor 2 (Nrf2), which regulates the expression of antioxidant and detoxification genes, showed significant susceptibility to airway inflammatory responses when exposed to diesel exhaust particles for eight weeks. As disruption of Nrf2 promotes immune cells that stimulate Th2-like immunoresponsiveness, Nrf2-deficient mice may be resistant to M. tuberculosis infection.

SETTING

Nrf2-deficient mice were infected with M. tuberculosis aerially, and the size of their granulomas and cytokine mRNA expression were compared with those of wild-type mice.

RESULTS

Significant reduction of granuloma formation and tubercle bacilli in granulomas was noted in the deficient mice 27 weeks after infection, concurrently with higher expression of IL-2 and IL-13 mRNA.

CONCLUSION

It is concluded that Nrf2 inversely regulates M. tuberculosis-induced granuloma development at the late stage.

Cross-resistance of Mycobacterium tuberculosis isolates among streptomycin, kanamycin and amikacin

Seventy-four streptomycin (SM)-resistant M. tuberculosis clinical isolates were subjected to cross-resistance drug testing against two major aminoglycosides, kanamycin (KM) and amikacin (AMK). Among them, 15 clinical isolates (20.3%) were resistant to both KM and AMK. Fifteen (80%) of 19 KM-resistant isolates were AMK-resistant. Fifteen SM, KM, and AMK resistant isolates harbored rrs mutation, but only two had rrs and rpsL double mutations. Low-level SM resistance was associated with rpsL mutation, whereas high-level SM resistance was linked to rrs mutation.

Protective efficacy of recombinant BCG Tokyo (Ag85A) in rhesus monkeys (Macaca mulatta) infected intratracheally with H37Rv Mycobacterium tuberculosis

We have reported previously that recombinant BCG Tokyo (Ag85A) (rBCG-Ag85A[Tokyo]) shows promise as a tuberculosis vaccine, demonstrating protective efficacy in cynomolgus monkeys. As a next step, rhesus monkeys were utilized because they are also susceptible to Mycobacterium tuberculosis and show a continuous course of infection resembling human tuberculosis. The recombinant BCG vaccine (5x10(5) CFU per monkey) was administered once intradermally into the back skin to three groups of rhesus monkeys, and its protective efficacy was compared for 4months with that of its parental BCG Tokyo strain. Eight week vaccination of the monkeys with rBCG-Ag85A[Tokyo] resulted in a reduction of tubercle bacilli CFU (p<0.01) and lung pathology in animals infected intratracheally with 3000 CFU H37Rv M. tuberculosis. Vaccination prevented an increase in the old tuberculin test after challenge with M. tuberculosis and reaction of M. tuberculosis-derived antigen. Thus, it was shown that even in rhesus monkeys rBCG-Ag85A[Tokyo] induced higher protective efficacy than BCG Tokyo.

Recombinant BCG Tokyo (Ag85A) protects cynomolgus monkeys (Macaca fascicularis) infected with H37Rv Mycobacterium tuberculosis

One tuberculosis vaccine candidate that has shown a promising degree of protective efficacy in guinea pigs is recombinant BCG Tokyo (Ag85A)(rBCG-Ag85A[Tokyo]). As a next step, cynomolgus monkeys were utilized because they are susceptible to Mycobacterium tuberculosis and develop a continuous course of infection that resembles that in humans both clinically and pathologically. The recombinant BCG vaccine was administered once intradermally in the back skin to three groups of cynomolgus monkeys, and its protective efficacy was compared for 4 months with that of its parental BCG Tokyo strain. Vaccination of the monkeys with the rBCG-Ag85A[Tokyo] resulted in a reduction of tubercle bacilli CFU (p<0.01) and lung pathology in animals challenged intratracheally with 3000 CFU H37Rv M. tuberculosis. Vaccination prevented an increase in the old tuberculin test after challenge with M. tuberculosis and reaction of M. tuberculosis-derived antigen. Thus, it was shown in monkeys that rBCG-Ag85A[Tokyo] induced higher protective efficacy than BCG Tokyo. This warrants further clinical evaluation.

Protective efficacy of recombinant (Ag85A) BCG Tokyo with Ag85A peptide boosting against Mycobacterium tuberculosis-infected guinea pigs in comparison with that of DNA vaccine encoding Ag85A

A recombinant form of BCG Tokyo with an Ag85A gene insert was administered once subcutaneously to guinea pigs and its protective efficacy was compared with that of a DNA vaccine encoding Ag85A from Mycobacterium tuberculosis administered twice to guinea pigs by epidermal gene gun bombardment. Vaccination with either the recombinant BCG Tokyo or Ag85A DNA significantly reduced the severity of pulmonary pathology and the number of pulmonary and splenic colony-forming units (cfu) (p<0.001). The recombinant BCG Tokyo was better than Ag85A DNA in terms of protective efficacy against M. tuberculosis. When immunogenic synthetic Ag85A peptide was further used as a booster together with recombinant BCG Tokyo (Ag85A) or Ag85A DNA, lung pathology was improved significantly and the number of pulmonary CFU was reduced significantly. Neither recombinant BCG Tokyo, Ag85A DNA, nor the parental BCG Tokyo protected the guinea pigs from hematogenous spread of tubercle bacilli to the spleen because splenic granulomas without central necrosis were recognized. The spleen tissues from guinea pigs vaccinated with recombinant BCG Tokyo or Ag85A DNA expressed IFN-gamma and IL-2 mRNA at significantly high levels (p<0.001) as evaluated by reverse transcription polymerase chain reaction. It is concluded that peptide boosting is important for the induction of higher protective efficacy by recombinant BCG Tokyo or a tuberculosis DNA vaccine and both recombinant BCG Tokyo (Ag85A) and Ag85A DNA vaccine induce Th2 cytokine mRNA expression significantly.

Mycobacterial infection in natural killer T cell knockout mice

To gain a better understanding of the pathological role of natural killer (NK) T cells in murine tuberculosis, NKT knockout (KO) mice (J(alpha)281(-/-)mice) were utilized. Eight-week-old NKT KO mice of BALB/c origin and wild-type (WT) mice were infected with Mycobacterium tuberculosis Kurono strain by the airborne route using an airborne infection apparatus, and their capacity to control mycobacterial growth, granuloma formation, and cytokine production were examined. The NKT KO mice developed granulomatous lesions in the lungs; there was no statistically significant difference in pulmonary granuloma size between NKT KO and WT mice (p<0.01). The average CFU values increased 3 weeks post-infection, but decreased 9 and 11 weeks post-infection, in the lungs of NKT KO mice. When stimulated with Kurono strain in vitro, splenic cells from NKT KO mice produced less IFN-gamma than did those from WT mice. Expression of mRNA for IL-2, IL-4, IL-6, IL-10 and IL-12 p40 was slightly lower in NKT KO mice compared with WT mice. Our data indicate that NKT cells play a detrimental role in late-phase mycobacterial infection, although Th1 cells are essential in early-phase mycobacterial infection.

Relative importance of STAT4 in murine tuberculosis

This study was designed to determine the roles of STAT proteins in defence against mycobacterial infection. Airborne infection of STAT4 knockout (KO) mice with a Mycobacterium tuberculosis strain induced large granulomas with massive neutrophil infiltration over time, while that in STAT6 KO mice did not. The STAT4 KO mice succumbed to mycobacterial infection by the 80th day after infection. Compared with the levels in wild-type (WT) and STAT6 KO mice, pulmonary inducible nitric oxide synthase, interferon-alpha, -beta and -gamma mRNA levels were significantly lower in STAT4 KO mice, but expression of interleukin-2, -6, -12 and -18 mRNAs was slightly higher up to the fifth week after aerial infection. Therefore, STAT4, but not STAT6, appears to be a critical transcription factor in mycobacterial regulation.

Vaccination of guinea pigs with DNA encoding Ag85A by gene gun bombardment

A DNA vaccine encoding Ag85A from Mycobacterium tuberculosis was administered to guinea pigs by epidermal gene gun bombardment and its protective efficacy was determined. Vaccination with Ag85A DNA twice significantly reduced the severity of pulmonary pathology and number of pulmonary colony-forming units (CFU) (p<0.01). When immunogenic synthetic Ag85A peptide was used as a booster, lung pathology was improved significantly and pulmonary CFU were reduced dramatically. Neither Ag85A DNA nor BCG Tokyo protected the guinea pigs from hematogenous spread of tubercle bacilli to the spleen because splenic granulomas without central necrosis were recognized. When the vaccinated guinea pigs were followed up for 7 months, the pulmonary lesions became fibrotic in guinea pigs vaccinated with Ag85A DNA plus Ag85A peptide, or BCG Tokyo, and no tubercle bacilli were detected. The protective efficacy of the tuberculosis Ag85A DNA vaccine was improved significantly by peptide boosting. It is concluded that dosage and peptide boosting are important in the induction of higher protective efficacy by a tuberculosis DNA vaccine.

Role of interleukin (IL)-1 type 1 receptor in mycobacterial infection

It is important to gain a better understanding of IL-1-mediated signaling events in mycobacterial infection. In order to clarify the role of IL-1 receptor type 1 (IL-1 R1) in IL-1 R1, knockout (KO) mice were infected with either Mycobacterium tuberculosis H37Rv or Kurono strain by the respiratory route, and their ability to control mycobacterial growth, pulmonary granuloma formation, and cytokine mRNA expression was investigated. IL-1 R1 KO mice developed significantly larger (P< 0.01) granulomatous lesions with neutrophil infiltration in their lungs than wild-type mice did after infection with the M. tuberculosis Kurono strain. The number of mycobacterial colonies in lungs and spleen increased from five weeks post-infection. Interferon-y production by spleen cells was low in IL-1 R1 KO mice. It is concluded that the IL-1 R1 is essential for IL-1-mediated signaling events in mycobacterial infection.

Pulmonary granulomas of guinea pigs induced by inhalation exposure of heat-treated BCG Pasteur, purified trehalose dimycolate and methyl ketomycolate

This study was designed to determine the identity of granulomatogenic substances in Mycobacterium bovis BCG Pasteur. When heat-treated BCG Pasteur bacilli were introduced into the lungs of guinea-pigs by an inhalation exposure apparatus, pulmonary granulomas without necrosis developed. Furthermore, when four kinds of mycolates derived from M. tuberculosis Aoyama B strain were introduced into the lungs by the same method, only trehalose 6,6'-dimycolate (TDM) and methyl ketomycolate induced pulmonary granulomas without central necrosis. The pulmonary granulomas consisted of epithelioid macrophages and lymphocytes. When a mixture of TDM and anti-TDM antibody was introduced into the lungs, development of granulomatous lesions was reduced. These data indicate that TDM and methyl ketomycolate are potent granulomatogenic reagents.

Relative importance of NF-kappaB p50 in mycobacterial infection

To understand the role of NF-kappaB in the development of murine tuberculosis in vivo, NF-kappaB p50 knockout mice were infected with Mycobacterium tuberculosis by placing them in the exposure chamber of an airborne-infection apparatus. These mice developed multifocal necrotic pulmonary lesions or lobar pneumonia. Compared with the levels in wild-type mice, pulmonary inducible nitric oxide synthase, interleukin-2 (IL-2), gamma interferon, and tumor necrosis factor alpha mRNA levels were significantly low but expression of IL-10 and transforming growth factor beta mRNAs were within the normal ranges. The pulmonary IL-6 mRNA expression level was higher. Therefore, NF-kappaB and its interaction with host cells play an important role in the pathogenesis of tuberculosis.

Biological characteristics and chemosensitivity profile of four human anaplastic thyroid carcinoma cell lines

Anaplastic thyroid carcinoma is a rapidly growing, aggressive neoplasm affecting the elderly which does not respond to most of the therapies. We established cultured cell lines from four untreated tumors. The cultures grew in a monolayer of spindle-shaped cells in three cell lines and of small polygonal cells in one line, having relatively long doubling times and chromosomal abnormalities. The xenotransplantation of the lines in athymic nude mice produced tumors with a histology similar to the original tumors. The immunocytochemical staining showed the expression of PCNA, HLA-class 1, cytokeratin, vimentin and FAS (fatty acid synthase) but not CEA, desmin or P-glycoprotein. The lines secreted TPA, IL-6, IL-8 and few or no thyroid-related hormones in the culture supernatant. One cell line produced G-CSF. The chemosensitivity assay revealed intrinsic drug resistance to nine out of 11 antineoplastic agents. The reverse transcriptase-polymerase chain reaction (RT-PCR) detected MRP (multidrug resistance-associated protein) mRNA but not mdr (multidrug resistance protein)-1 and mdr-3 mRNAs. This finding indicates that the multidrug resistance of these lines is mediated by a P-glycoprotein-unrelated mechanism. The RT-PCR also presented FAS mRNA in all the lines, and IL-6 and IL-8 mRNAs in some of the lines.

IL-4 is required for defense against mycobacterial infection

Although the involvement of T helper (Th1) cells is central to protection against intracellular bacteria, including Mycobacterium tuberculosis, the involvement of Th2 cells, characterized by potent interleukin (IL)-4 secretion in mycobacterial infection is still unclear. In order to clarify the role of IL-4 in murine tuberculosis, IL-4-deficient mutant mice, IL-4 knockout (IL-4 KO) mice, were utilized. The mice were infected with H37Rv, Kurono or BCG Pasteur via an airborne infection route by placing them in the exposure chamber of a Middlebrook airborne infection apparatus. Their capacity to control mycobacterial growth, granuloma formation, cytokine secretion, and nitric oxide (NO) production were examined. These mice developed large granulomas, but not necrotic lesions in the lungs, liver or spleen (P<0.05). This was consistent with a significant increase in lung colony-forming units (CFU). Compared with levels in wild-type mice, upon stimulation with mycobacteria, splenic IL-10 levels were low and IL-6 levels were intermediate, but interferon (IFN)-gamma and IL-12 levels were significantly higher. IL-18 levels were within the normal range. The level of NO production by alveolar macrophages of the IL-4 KO mice was similar to that of the wild-type mice. Granulomatous lesion development by IL-4 KO mice was inhibited significantly by treatment with exogenous recombinant IL-4. These findings were not specific to the IL-4 KO mice used. Our data show that IL-4 may play a protective role in defense against mycobacteria, although IFN-gamma and TNF-alpha play major roles in it. Our data do not rule out an IFN-gamma-independent function of IL-4 in controlling tuberculosis.

Disruption of nuclear factor-interleukin-6, a transcription factor, results in severe mycobacterial infection

Nuclear factor-interleukin-6 (NF-IL-6) is one of several nuclear transcription factors (NF-IL-6, NF-kappaB, PU.1, interferon-regulatory factor 1, Egr-1, and Stat-1). NF-IL-6 and NF-kappaB are expressed in macrophages and is induced by bacterial lipopolysaccharides. To evaluate whether NF-IL-6 is required for the inflammatory immune response to mycobacterial infection, in which epithelioid macrophages comprise the leading cell population, we generated NF-IL-6 knockout (KO) mutant mice. Airborne infection of these mice with Mycobacterium tuberculosis strains induced disseminated tuberculosis lacking granuloma formation, although interferon-gamma, tumor necrosis factor-alpha, and interleukin-12 mRNA expression levels were within the normal range compared with those of wild-type mice. Generation of O2- and mycobacterial killing by neutrophils from these mice were impaired severely compared with wild-type mice. We conclude that NF-IL-6 is a critical transcription factor in mycobacterial control as well as in granulocyte-colony stimulating factor induction resulting in neutrophil activation.

Early oxidative DNA damages and late development of lung cancer in diesel exhaust-exposed rats

To demonstrate DNA damages in the early stage of diesel exhaust exposure, an inhalation study of 1 through 12 months was conducted. The lung burden of diesel soot increased with increase in exposure duration. Histologically, hyperplastic foci of alveolar epithelia were found at 6-month exposure and became prominent at the 12th month, with slight nuclear atypia and positive p53 staining. The level of 8-OH-hydroxyguanosine (8-OH-dG) in the exposed rat lungs showed an increase from 1 month of exposure, followed by a gradual increase, reaching almost a plateau level at the 9th month. An in vitro experiment demonstrated significant 8-OH-dG formation when diesel particles and H(2)O(2) were added to the DNA solution. The level of bulky aromatic DNA adducts peaked at the 1st month of exposure, followed by a decrease. By the end of the observation period of 30 months, lung tumors developed even in the 6-month exposure group, and the earliest lung tumors were found only in rats that survived longer than 18 months. In conclusion, persisting oxidative stress on DNA induced in the early phase of diesel exhaust exposure, together with inflammation, seems to play an important role in carcinogenesis at advance ages after a long latent period.

Secondary infections of AIDS autopsy cases in Japan with special emphasis on Mycobacterium avium-intracellulare complex infection

In order to study the frequency of secondary infections of AIDS autopsy cases in Japan, especially the frequency of Mycobacterium aviumintracellulare complex (MAC) infection, retrospective autopsy study was conducted between 1986 and 1997 at the affiliated hospital of Institute of Medical Sciences, University of Tokyo. Secondary infections of various organs from 43 AIDS autopsy cases were examined using histopathology, genetic diagnosis of tuberculosis, Ziehl-Neelsen stain for acid-fast bacilli and immunohistochemistry. Nontuberculous mycobacterial infection (Mycobacterium avium) was observed in 17 cases (40%) out of 43 using polymerase chain reaction (PCR), but M. tuberculosis infection was not observed. Ziehl-Neelsen staining showed a positive reaction in lung and spleen tissues of 7 AIDS autopsy cases. Immunohistochemistry using anti-BCG antibody revealed positivity in 7 AIDS autopsy cases. CD4 counts of 17 AIDS patients with mycobacterial infection were less than 18.7/microl. Other opportunistic infections were also examined by histopathology. Secondary infections were present in every case, and these included cytomegalovirus infection (32 cases), Pneumocystis carinii (15 cases), Candida (16 cases), Aspergillus (12 cases), Cryptococcus (6 cases), Toxoplasma (6 cases), methicillin-resistant Staphylococcus aureus (3 cases), herpes virus (1 case) and Entamoeba histolytica (1 case). Malignant lymphoma was recognized in 14 cases and Kaposi's sarcoma in 6. This is the systemic report on secondary infections of AIDS autopsy cases in Japan. In diagnosis of mycobacterial infections, PCR was more useful than staining for acid-fast bacilli and immunohistochemistry. Secondary infections (especially mycobacterial infection) were closely associated with the low CD4 count.

Expression of thioredoxin in granulomas of sarcoidosis: possible role in the development of T lymphocyte activation

BACKGROUND

Activated T lymphocytes are one of the characteristic features of sarcoidosis. The mechanism of T cell activation, expressing various activation markers including interleukin 2 receptor (IL-2R), has been extensively investigated but the precise mechanism remains unknown. Although thioredoxin (TRX) displays a number of biological activities including IL-2R inducing activity, its role in the induction of IL-2R expression on T cells in sarcoidosis has not been determined. The expression of TRX and IL-2R in granulomas of patients with sarcoidosis has been studied to clarify a possible role for TRX in the induction of IL-2R expression.

METHODS

Granulomas in specimens of lung tissue and lymph nodes from five patients with sarcoidosis were immunohistochemically stained with anti-TRX antibody and anti-IL-2Ralpha chain antibody and the concentration of TRX in the bronchoalveolar lavage (BAL) fluid from 20 patients with pulmonary sarcoidosis was measured.

RESULTS

Granulomas in lung and lymph node tissue from patients with sarcoidosis showed strong reactivity with anti-TRX antibody. Positive staining was present in the macrophages, epithelioid cells, and Langhans' type giant cells but not in lymphocytes. IL-2R was expressed on lymphocytes in the same granulomas. By contrast, positive immunoreactivity was not found in lung tissue specimens from 12 control subjects. Concentrations of TRX in BAL fluid were higher in patients with pulmonary sarcoidosis (median (range) 122.6 (20.9-303.3) ng/ml) than in control subjects (32.9 (16.8-52.8) ng/ml, p<0.05).

CONCLUSIONS

TRX is highly expressed and is locally produced by granulomas in patients with sarcoidosis. The coexistence of immunoreactive TRX and IL-2R in the same granulomas suggests that TRX might act as a local inducing factor for IL-2R expression on T cells.