Dental Status and Compression of Life Expectancy with Disability

This study examined whether the number of teeth contributes to the compression of morbidity, measured as a shortening of life expectancy with disability, an extension of healthy life expectancy, and overall life expectancy. A prospective cohort study was conducted. A self-reported baseline survey was given to 126,438 community-dwelling older people aged ≥65 y in Japan in 2010, and 85,161 (67.4%) responded. The onset of functional disability and all-cause mortality were followed up for 1,374 d (follow-up rate = 96.1%). A sex-stratified illness-death model was applied to estimate the adjusted hazard ratios (HRs) for 3 health transitions (healthy to dead, healthy to disabled, and disabled to dead). Absolute differences in life expectancy, healthy life expectancy, and life expectancy with disability according to the number of teeth were also estimated. Age, denture use, socioeconomic status, health status, and health behavior were adjusted. Compared with the edentulous participants, participants with ≥20 teeth had lower risks of transitioning from healthy to dead (adjusted HR, 0.58 [95% confidence interval (CI), 0.50-0.68] for men and 0.70 [95% CI, 0.57-0.85] for women) and from healthy to disabled (adjusted HR, 0.52 [95% CI, 0.44-0.61] for men and 0.58 [95% CI, 0.49-0.68] for women). They also transitioned from disabled to dead earlier (adjusted HR, 1.26 [95% CI, 0.99-1.60] for men and 2.42 [95% CI, 1.72-3.38] for women). Among the participants aged ≥85 y, those with ≥20 teeth had a longer life expectancy (men: +57 d; women: +15 d) and healthy life expectancy (men: +92 d; women: +70 d) and a shorter life expectancy with disability (men: -35 d; women: -55 d) compared with the edentulous participants. Similar associations were observed among the younger participants and those with 1 to 9 or 10 to 19 teeth. The presence of remaining teeth was associated with a significant compression of morbidity: older Japanese adults' life expectancy with disability was compressed by 35 to 55 d within the follow-up of 1,374 d

Income or education, which has a stronger association with dental implant use in elderly people in Japan?

OBJECTIVES Although inequalities in dental implant use based on educational level have been reported, no study has used income as a proxy for the socioeconomic status. We examined: (i) income inequalities in implant use; and (ii) whether income or education has a stronger association with implant use in elder Japanese. METHODS In 2016, a self‐reported questionnaire was mailed to participants aged 65 years or older living across Japan as part of the ongoing Japan Gerontological Evaluation Study. We used data from 84,718 respondents having 19 or fewer teeth. After multiple imputation, multi‐level logistic regression estimated the association of dental implant use with equivalised income level and years of formal education. Confounders were age, sex, and density of dental clinics in the residential area. RESULTS 3.1% of respondents had dental implants. Percentages of dental implant use among the lowest (≤ 9 years) and highest (≥ 13 years) educational groups were 1.8 and 5.1, respectively, and among the lowest (0 < 12.2 ‘1,000 USD/year’) and highest (≥ 59.4 ‘1,000 USD/year’) income groups were 1.7 and 10.4, respectively. A fully adjusted model revealed that both income and education were independently associated with dental implant use. Odds ratios for implant use in the highest education and income groups were 2.13 [95% CI = 1.94–2.35] and 4.85 [95% CI = 3.78–6.22] compared with the lowest education and income groups, respectively. From a model with standardised variables, income showed slightly stronger association than education. CONCLUSION This study reveals a public health problem that even those with the highest education but low income might have limited accessibility to dental implant services

Examining the associations between oral health and social isolation: A cross-national comparative study between Japan and England.

In Western countries, the most important part of the face in communication is the mouth, whereas it is the eyes in Asian countries; thus oral health could be more important in social interactions in Western countries. Our aim was to examine differences in the association between oral health status and social isolation among older people by comparing Japan and England. We used cross-sectional information obtained from adults aged 65+ in two ongoing prospective cohort studies: The Japan Gerontological Evaluation Study (JAGES, N = 120,195) and the English Longitudinal Study of Ageing (ELSA, N = 3,958). The dependent variable, social isolation score (SIS) was calculated from five factors (marital status, social support from children, social support from family, social support from friends, and social participation). The independent variables were self-reported number of remaining teeth (0, 1–9, 10–19, ≥20) and denture use (≥20 teeth, 10–19 teeth with denture, 10–19 teeth without denture, 0–9 teeth with denture, 0–9 teeth without denture), while the covariates in the model were: sex, age, educational attainment, self-rated health, number of comorbidities, household annual equivalized income, mental health status, daily living activities, and smoking status. We examined associations between oral health status and SIS by applying an ordered logit model by country. Compared to England, more Japanese participants were socially isolated (1.4% vs. 5.8%), but fewer were edentulous (13.1% vs. 7.7%). In both countries, poorer oral health further increased the odds of being socially isolated. Pooled analysis of the ordered logit model with an interaction term showed that the association of number of remaining teeth with SIS was stronger in edentulous participants and in England (odds ratio = 1.50, 95% Confidence interval:1.26–1.80). In both countries, oral health was associated with social isolation; this association could be stronger in England than in Japan

Tooth Loss and Decline in Functional Capacity: A Prospective Cohort Study from the Japan Gerontological Evaluation Study

OBJECTIVES: To describe associations between tooth loss and changes in higher-level functional capacity. DESIGN: Prospective cohort study. SETTING: Twenty-four Japanese municipalities between 2010 and 2013. PARTICIPANTS: Functionally independent community-dwelling persons aged 65 and older (N = 62,333). MEASUREMENTS: Self-reported number of teeth was used as an exposure variable. The outcome was changes in higher-level functional capacity measured using the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC), which consists of three domains: instrumental activities of daily living, intellectual activity, and social roles. The TMIG-IC score ranges from 0 (lowest function) to 13 (highest function). All covariates were chosen from baseline demographic, socioeconomic, health behavior, and health variables based upon evidence from previous studies. Inverse-probability weighting (IPW) with propensity score and multiple linear regression, estimating nonstandardized coefficients (β) and 95% confidence intervals (CIs), were used. RESULTS: The baseline response rate was 65.2%, and the follow-up rate was 70.1%. During the follow-up period, participants' TMIG-IC score declined by an average of 0.247 points (standard deviation: 1.446). The results showed a significant dose-response association between tooth loss and decline in higher-level functional capacity in multiple linear regression models. IPW models estimated the increment in TMIG-IC score (β = 0.170, 95% CI = 0.114-0.227) if edentulous participants gained 20 or more natural teeth. CONCLUSION: Tooth loss is associated with future decline in higher-level functional capacity. IPW models suggest that treatment for tooth loss attenuates decline in higher-level functional capacity

The XMM cluster survey: Testing chameleon gravity using the profiles of clusters

The chameleon gravity model postulates the existence of a scalar field that couples with matter to mediate a fifth force. If it exists, this fifth force would influence the hot X-ray emitting gas filling the potential wells of galaxy clusters. However, it would not influence the clusters weak lensing signal. Therefore, by comparing X-ray and weak lensing profiles, one can place upper limits on the strength of a fifth force. This technique has been attempted before using a single, nearby cluster (Coma, z = 0.02). Here we apply the technique to the stacked profiles of 58 clusters at higher redshifts (0.1 R0| R0| on cosmological scales. We hope to improve this constraint in future by extending the study to hundreds of clusters using data from the Dark Energy Survey

Galactic and Extragalactic Samples of Supernova Remnants: How They Are Identified and What They Tell Us

Supernova remnants (SNRs) arise from the interaction between the ejecta of a supernova (SN) explosion and the surrounding circumstellar and interstellar medium. Some SNRs, mostly nearby SNRs, can be studied in great detail. However, to understand SNRs as a whole, large samples of SNRs must be assembled and studied. Here, we describe the radio, optical, and X-ray techniques which have been used to identify and characterize almost 300 Galactic SNRs and more than 1200 extragalactic SNRs. We then discuss which types of SNRs are being found and which are not. We examine the degree to which the luminosity functions, surface-brightness distributions and multi-wavelength comparisons of the samples can be interpreted to determine the class properties of SNRs and describe efforts to establish the type of SN explosion associated with a SNR. We conclude that in order to better understand the class properties of SNRs, it is more important to study (and obtain additional data on) the SNRs in galaxies with extant samples at multiple wavelength bands than it is to obtain samples of SNRs in other galaxiesComment: Final 2016 draft of a chapter in "Handbook of Supernovae" edited by Athem W. Alsabti and Paul Murdin. Final version available at https://doi.org/10.1007/978-3-319-20794-0_90-

Matrix Metalloprotease 9 Mediates Neutrophil Migration into the Airways in Response to Influenza Virus-Induced Toll-Like Receptor Signaling

The early inflammatory response to influenza virus infection contributes to severe lung disease and continues to pose a serious threat to human health. The mechanisms by which neutrophils gain entry to the respiratory tract and their role during pathogenesis remain unclear. Here, we report that neutrophils significantly contributed to morbidity in a pathological mouse model of influenza virus infection. Using extensive immunohistochemistry, bone marrow transfers, and depletion studies, we identified neutrophils as the predominant pulmonary cellular source of the gelatinase matrix metalloprotease (MMP) 9, which is capable of digesting the extracellular matrix. Furthermore, infection of MMP9-deficient mice showed that MMP9 was functionally required for neutrophil migration and control of viral replication in the respiratory tract. Although MMP9 release was toll-like receptor (TLR) signaling-dependent, MyD88-mediated signals in non-hematopoietic cells, rather than neutrophil TLRs themselves, were important for neutrophil migration. These results were extended using multiplex analyses of inflammatory mediators to show that neutrophil chemotactic factor, CCL3, and TNFα were reduced in the Myd88−/− airways. Furthermore, TNFα induced MMP9 secretion by neutrophils and blocking TNFα in vivo reduced neutrophil recruitment after infection. Innate recognition of influenza virus therefore provides the mechanisms to induce recruitment of neutrophils through chemokines and to enable their motility within the tissue via MMP9-mediated cleavage of the basement membrane. Our results demonstrate a previously unknown contribution of MMP9 to influenza virus pathogenesis by mediating excessive neutrophil migration into the respiratory tract in response to viral replication that could be exploited for therapeutic purposes