BACKGROUND: The burden of dementia is growing rapidly and has become a medical and social problem in Japan. Prospective cohort studies have been considered an effective methodology to clarify the risk factors and the etiology of dementia. We aimed to perform a large-scale dementia cohort study to elucidate environmental and genetic risk factors for dementia, as well as their interaction. METHODS: The Japan Prospective Studies Collaboration for Aging and Dementia (JPSC-AD) is a multisite, population-based prospective cohort study of dementia, which was designed to enroll approximately 10,000 community-dwelling residents aged 65 years or older from 8 sites in Japan and to follow them up prospectively for at least 5 years. Baseline exposure data, including lifestyles, medical information, diets, physical activities, blood pressure, cognitive function, blood test, brain magnetic resonance imaging (MRI), and DNA samples, were collected with a pre-specified protocol and standardized measurement methods. The primary outcome was the development of dementia and its subtypes. The diagnosis of dementia was adjudicated by an endpoint adjudication committee using standard criteria and clinical information according to the Diagnostic and Statistical Manual of Mental Disorders, 3rd Revised Edition. For brain MRI, three-dimensional acquisition of T1-weighted images was performed. Individual participant data were pooled for data analyses. RESULTS: The baseline survey was conducted from 2016 to 2018. The follow-up surveys are ongoing. A total of 11,410 individuals aged 65 years or older participated in the study. The mean age was 74.4 years, and 41.9% were male. The prevalence of dementia at baseline was 8.5% in overall participants. However, it was 16.4% among three sites where additional home visit and/or nursing home visit surveys were performed. Approximately two-thirds of dementia cases at baseline were Alzheimer's disease. CONCLUSIONS The prospective cohort data from the JPSC-AD will provide valuable insights regarding the risk factors and etiology of dementia as well as for the development of predictive models and diagnostic markers for the future onset of dementia. The findings of this study will improve our understanding of dementia and provide helpful information to establish effective preventive strategies for dementia in Japan.
Aged ; Alzheimer Disease/genetics* ; Dementia/genetics* ; Environment ; Female ; Humans ; Incidence ; Japan/epidemiology* ; Male ; Middle Aged ; Prevalence ; Prospective Studies ; Risk Factors

Objective：To elucidate factors associated with physical function and clarify the actual condition of functional deterioration in patients with knee osteoarthritis (OA) prior to total knee arthroplasty (TKA)．

Methods：We enrolled 467 patients with severe knee OA and preoperatively assessed the following parameters：background factors (sex, age, BMI, K-L grade, and pain) and physical function (muscle strength of knee extensors and flexors, and knee joint angles). A multiple regression analysis was performed to determine the relationship between the independent background factors and dependent physical functions. The median of preoperative function based on selected factors of physical function was calculated.

Results：Based on the multiple regression analysis, sex, BMI, K-L grade, and pain statistically significantly correlated with muscle strength of knee extensors and flexors. Sex and BMI statistically significantly correlated with knee joint flexion angle. K-L grade statistically significantly correlated with knee joint extension angle. The median of muscle strength for knee extension was 0.98/0.92 Nm/kg (Grade 3/Grade 4) for males and 0.70/0.59 Nm/kg for females. The median of muscle strength for knee flexion was 0.53/0.45 Nm/kg for males, 0.36/0.30 Nm/kg for females. The median for knee joint flexion angle was 130° for males and 120° for females. The median for knee joint extension angle was -5°/-10° (Grade 3/Grade 4)．

Conclusion：We clarified the degree of muscle strength and range of motion before TKA in patients with knee OA. We believe that the findings obtained in this study will contribute to explaining the functional deterioration of patients with knee OA.

Objective：The aim of this study was to examine the relationships between the timing of gait acquisition and the length of hospitalization, and to clarify the differences in background factors and functional recovery during the early postoperative period and their effect on the variability in gait acquisition.
Methods：We recruited 148 patients who underwent total knee arthroplasty (TKA) at three hospitals. The participants were divided into two groups on the basis of the number of days needed to achieve independent gait at ≤14 days after surgery (group A) and ＞14 days after surgery (group B). We compared the background factors between the two groups. Additionally, we compared the preoperative and postoperative function in each group.
Results：We observed a significant positive correlation between the number of days needed to achieve independent gait and the length of hospitalization. In group A, the significant background factors were younger age and higher preoperative activity level. In group A, compared with the level of preoperative function, the postoperative maximum knee extension angle on the operated side and pain had significantly improved. In both groups, the postoperative knee extensor strength on the operated side, knee extensor strength on the nonoperated side, knee flexion strength on the operated side, maximum knee flexion angle on the operated side, and walking speed were significantly reduced.
Conclusion：During early rehabilitation, it is necessary to consider the age and previous activities of patients. In addition, we suggest that early rehabilitation with a focus on reducing pain by alleviating inflammation and improving maximum knee extension angle on the operated side may be effective for fast acquisition of gait.

Although long-lasting insecticide-treated bednets (LLINs) have been widely used for malaria control, little is known about how the condition of LLINs affects the risk of malaria infection. The objective of this cross-sectional study was to examine the association between the use of LLINs with holes and caregiver-reported malaria diagnosed in children under five years of age (U5). Data were collected in Boboye health district, Niger, in 2010. Surveyors conducted interviews and bednet inspections in 1,034 households. If a household had a U5 child, the surveyor asked the caregiver whether the child had experienced a fever episode in the past two weeks that entailed standard treatment for uncomplicated malaria at a healthcare facility. The authors analyzed the association between the use of LLINs with holes and caregiver-reported malaria episodes in U5 children using logistic regression, adjusted for possible confounders. Of the 1,165 children included in the analysis, approximately half (53.3%) used an intact LLIN while far fewer (10.6%) used a LLIN with holes. Compared to children using an intact LLIN, children using a LLIN with holes were significantly more likely to have a caregiver-reported malaria episode (8.7% vs. 17.1%; odds ratio: 2.23; 95% confidence interval: 1.24–4.01). In this study site, LLINs with holes were less protective than intact LLINs.

Although long-lasting insecticide-treated bednets (LLINs) have been widely used for malaria control, little is known about how the condition of LLINs affects the risk of malaria infection. The objective of this cross-sectional study was to examine the association between the use of LLINs with holes and caregiver-reported malaria diagnosed in children under five years of age (U5). Data were collected in Boboye health district, Niger, in 2010. Surveyors conducted interviews and bednet inspections in 1,034 households. If a household had a U5 child, the surveyor asked the caregiver whether the child had experienced a fever episode in the past two weeks that entailed standard treatment for uncomplicated malaria at a healthcare facility. The authors analyzed the association between the use of LLINs with holes and caregiver-reported malaria episodes in U5 children using logistic regression, adjusted for possible confounders. Of the 1,165 children included in the analysis, approximately half (53.3%) used an intact LLIN while far fewer (10.6%) used a LLIN with holes. Compared to children using an intact LLIN, children using a LLIN with holes were significantly more likely to have a caregiver-reported malaria episode (8.7% vs. 17.1%; odds ratio: 2.23; 95% confidence interval: 1.24–4.01). In this study site, LLINs with holes were less protective than intact LLINs.

BACKGROUND/AIMS: Left-sided diverticulitis is increasing in Japan, and many studies report that left-sided diverticulitis is more likely to be severe. Therefore, it is important to identify the features and risk factors for left-sided diverticulitis. We hypothesized that left-sided diverticulitis in Japan is related to obesity and conducted a study of the features and risk factors for this disorder in Japan. METHODS: Right-sided diverticulitis and left-sided diverticulitis patients (total of 215) were compared with respect to background, particularly obesity-related factors to identify risk factors for diverticulitis. RESULTS: There were 166 (77.2%) right-sided diverticulitis patients and 49 (22.8%) left-sided diverticulitis patients. The proportions of obese patients (body mass index > or =25 kg/m2, p=0.0349), viscerally obese patients (visceral fat area > or =100 cm2, p=0.0019), patients of mean age (p=0.0003), and elderly patients (age > or =65 years, p=0.0177) were significantly higher in the left-sided-diverticulitis group than in the right-sided-diverticulitis group. The proportion of viscerally obese patients was significantly higher in the left-sided-diverticulitis group than in the left-sided-diverticulosis group (p=0.0390). CONCLUSIONS: This study showed that obesity, particularly visceral obesity, was a risk factor for left-sided diverticulitis in Japan.
Aged ; Diverticulitis ; Humans ; Japan ; Obesity ; Obesity, Abdominal ; Retrospective Studies ; Risk Factors

In Niger, insecticide-treated bed nets (ITNs) have been distributed to the target group of households with young children and/or pregnant women at healthcare facilities in the course of antenatal/immunization clinics. With the aim of universal coverage, ITNs were additionally distributed to households through strengthened community health committees in 2009. This study assessed the impact of the community-based net distribution strategy involving community health committees in the ITN coverage in Boboye Health District, Niger. A cross-sectional survey was carried out on 1,034 households drawn from the intervention area (the co-existence of the community-based system together with the facility-based system) and the control area (the facility-based system alone). In the intervention area, 55.8% of households owned ITNs delivered through the community-based system, and 29.6% of households exclusively owned ITNs obtained through the community-based system. The community-based system not only reached households within the target group (54.6% ownership) but also those without (59.1% ownership). Overall, household ITN ownership was significantly higher in the intervention area than in the control area (82.5% vs. 60.7%). In combination, the community-based system and the facility-based system achieved a high ITN coverage. The community-based system contributed to reducing leakage in the facility-based system.

OBJECTIVESMucosal immunity plays a pivotal role for body defense against infection and allergy. The aim of this study was to clarify the effects of 2,3,7,8-tetraclorodibenzo-p-dioxin (TCDD) on mucosal immunity in the gut.

METHODSFecal IgA level and oral tolerance induction were examined in TCDD-treated mice. Flow cytometric and histological analyses were also performed.

RESULTSSingle oral administration of low dose 2,3,7,8-TCDD resulted in a marked decrease in IgA secretion in the gut without any effects on the cellular components of gut-associated lymphoid tissues (GALT) including Peyer's patches (PPs) and mesenteric lymph nodes (LNs). Decressed IgA secretion by TCDD was not observed in aryl hydrocarbon receptor (AhR)-deficient mice. Flow cytometric analysis revealed that IgA B cells in PPs and the mesenteric LNs remained unchanged in the TCDD-treated mice. An immunofluorescence study also demonstrated that a significant number of cytoplasmic IgA cells were present in the lamina propria of the gut in the TCDD-treated mice. Furthermore, oral tolerance induction by ovalbumin (OVA) was impaired in the TCDD-treated mice and OVA-specific T cell proliferation occurred in the peripheral lymphoid tissues including the spleen and LNs.

CONCLUSIONSThese results suggest that a relatively low dose of TCDD impairs mucosal immunity in the gut and induces systemic sensitization by oral antigens.