Effect of Tooth Loss on Cognitive Function among Older Adults in Singapore.

Evidence suggests a longitudinal association between tooth loss and cognitive function. However, the temporality of this association is not well understood. We investigated the effect of several emulated tooth loss prevention scenarios on cognitive function. We used data from 3 waves (baseline: 2009, second wave: 2011-2012, and third wave: 2015) of the Panel on Health and Ageing of Singaporean Elderly (PHASE). PHASE targeted older adults, aged ≥60 y, in Singapore. Number of teeth was used as a time-varying exposure (baseline, second wave). Cognitive function (Short Portable Mental Status Questionnaire score) in the third wave was assessed as the outcome. Multiple time-invariant (baseline) and time-varying (baseline and second wave) covariates were included. The "longitudinal modified treatment policy approach" combined with targeted minimum loss-based estimation was used to define and estimate additive effects of emulated tooth loss prevention scenarios. Emulated scenarios were the following: what if edentate people retained 1 to 4 teeth (scenario 1), what if those with <5 teeth retained 5 to 9 teeth (scenario 2), what if those with <10 teeth retained 10 to 19 teeth (scenario 3), and what if everyone retained ≥20 teeth (scenario 4)? A total of 1,516 participants, excluding those with severe cognitive impairment, were included (male: 41.6%). The mean age at baseline was 70.6 y (SD = 7.1). The mean SPMSQ score at baseline was 2.06 (SD = 0.02) for edentulous, 1.55 (SD = 0.04) for 1 to 4 teeth, 1.61 (SD = 0.03) for 5 to 9 teeth, 1.73 (SD = 0.02) for 10 to 19 teeth, and 1.71 (SD = 0.02) for ≥20 teeth. Additive effect of hypothetical intervention gradually increased with intensity of prevention from scenario 1 to scenario 4 (scenario 1: -0.02 [95% CI, -0.08 to 0.04], scenario 2: -0.05 [95% CI, -0.11 to -0.00], scenario 3: -0.07 [95% CI, -0.14 to -0.00], scenario 4: -0.15 [95% CI, -0.23 to -0.06]). Emulated tooth loss prevention interventions were associated with better cognitive function score. Therefore, preventing tooth loss could potentially benefit maintenance of cognitive function among older adults.

Change in Geographic Accessibility to Dental Clinics Affects Access to Care.

Access to dental clinics is a feature of the neighborhood service environment that may influence oral health care utilization. However, residential selection poses a challenge to causal inference. By studying the involuntary relocation of survivors of the 2011 Great East Japan Earthquake and Tsunami (GEJE), we examined the association between changes in geographic distance to dental clinics and dental visits. Longitudinal data from a cohort of older residents in Iwanuma City directly impacted by the GEJE were analyzed in this study. The baseline survey was conducted in 2010, 7 mo before the occurrence of GEJE, and a follow-up was conducted in 2016. Using Poisson regression models, we estimated the incidence rate ratios (IRR) and 95% confidence intervals (CIs) for the uptake of denture use (as a proxy for dental visits) according to changes in distance from the nearest dental clinic to their house. Age at baseline, housing damage by the disaster, deteriorating economic conditions, and worsened physical activity were used as confounders. Among the 1,098 participants who had not worn dentures before the GEJE, 495 were men (45.1%), with a mean ± SD age at baseline of 74.0 ± 6.9 y. During the 6-year follow-up, 372 (33.9%) participants initiated denture use. Compared to those who experienced a large increase in distance to dental clinics (>370.0-6,299.1 m), a large decrease in distance to dental clinics (>429.0-5,382.6 m) was associated with a marginally significantly higher initiation of denture use among disaster survivors (IRR = 1.28; 95% CI, 0.99-1.66). The experience of major housing damage was independently associated with higher initiation of denture use (IRR = 1.77; 95% CI, 1.47-2.14). Improved geographic access to dental clinics may increase dental visits of disaster survivors. Further studies in non-disaster-affected areas are needed to generalize these findings.

Impact of Teeth on Social Participation: Modified Treatment Policy Approach.

Social participation prevents social isolation and loneliness among older adults while having numerous positive effects on their health and well-being in rapidly aging societies. We aimed to estimate the effect of retaining more natural teeth on social participation among older adults in Japan. The analysis used longitudinal data from 24,872 participants in the Japan Gerontological Evaluation Study (2010, 2013, and 2016). We employed a longitudinal modified treatment policy approach to determine the effect of several hypothetical scenarios (preventive scenarios and tooth loss scenarios) on frequent social participation (1 = at least once a week/0 = less than once a week) after a 6-y follow-up. The corresponding statistical parameters were estimated using targeted minimum loss-based estimation (TMLE) method. Number of teeth category (edentate/1-9/10-19/≥20) was treated as a time-varying exposure, and the outcome estimates were adjusted for time-varying (income, self-rated health, marital status, instrumental activities of daily living, vision loss, hearing loss, major comorbidities, and number of household members) and time-invariant covariates (age, sex, education, baseline social participation). Less frequent social participation was associated with older age, male sex, lower income, low educational attainment, and poor self-rated health at the baseline. Social participation improved when tooth loss prevention scenarios were emulated. The best preventive scenario (i.e., maintaining ≥20 teeth among each participant) improved social participation by 8% (risk ratio [RR] = 1.08; 95% confidence interval [CI], 1.05-1.11). Emulated tooth loss scenarios gradually decreased social participation. A hypothetical scenario in which all the participants were edentate throughout the follow-up period resulted in a 11% (RR = 0.89; 95% CI, 0.84-0.94) reduction in social participation. Subsequent tooth loss scenarios showed 8% (RR = 0.92; 95% CI, 0.88-0.95), 6% (RR = 0.94; 95% CI, 0.91-0.97), and 4% (RR = 0.96; 95% CI, 0.93-0.98) reductions, respectively. Thus, among Japanese older adults, retaining a higher number of teeth positively affects their social participation, whereas being edentate or having a relatively lower number of teeth negatively affects their social participation.

Weight Loss Mediated the Relationship between Tooth Loss and Mortality Risk.

Tooth loss is a risk factor for increased mortality; however, the underlying mechanism remains unclear. This study aimed to evaluate the mediating effect of weight change on the relationship between tooth loss and mortality risk. This was a 10-y follow-up prospective cohort study using the data from the Japan Gerontological Evaluation Study (JAGES). The participants were independent older adults aged ≥65 y at baseline and were followed up from 2010 to 2020. The incidence of death in 2013 and 2020, incidence of >5% weight loss/gain in 2010 and 2013, and the number of remaining teeth in 2010 were used as the outcome, mediator, and explanatory variables, respectively. We conducted causal mediation analysis by fitting the Cox proportional hazard model, including possible confounders. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) of the total effect (TE), natural indirect effect (NIE), and proportion mediated (PM) were estimated. Among the 34,510 participants, the mean age was 72.6 (SD = 5.4) y, and 47.6% were men. From 2013 to 2020, 14.0% of the participants (n = 4,825) died, 60.5% (n = 20,871) had 0 to 19 remaining teeth, and 17.2% (n = 5,927) and 8.4% (n = 2,907) experienced >5% weight loss and gain, respectively. The mortality rate was 0.016 per person-year among those with ≥20 remaining teeth and 0.027 per person-year among those with 0 to 19 remaining teeth. Weight loss of >5% significantly mediated the association between tooth loss and higher mortality risk (TE: HR, 1.28 [95% CI, 1.16 to 1.40]; NIE: HR, 1.03 [95% CI, 1.02 to 1.04]; PM, 13.1%); however, we observed a slight mediating effect for >5% weight gain (NIE: HR, 1.003 [95%CI, 1.0001 to 1.01]; PM, 1.3%). The present study suggests that a clinically meaningful level of weight loss mediated the association between tooth loss and increased risk of mortality among independent older adults.

Oral Status and Dementia Onset: Mediation of Nutritional and Social Factors.

Some modifiable risk factors for dementia are closely related to oral health. Although eating and speaking abilities are fundamental oral functions, limited studies have focused on the effect of malnutrition and lack of social interaction between oral health and dementia. We investigated the mediating effects of nutritional and social factors on the association between the number of teeth and the incidence of dementia. This 6-y cohort study used data from the Japan Gerontological Evaluation Study targeting older adults aged 65 y and above. The number of teeth (exposure) and covariates in 2010 (baseline survey), mediators (weight loss, vegetable and fruit intake, homeboundness, social network) in 2013, and the onset of dementia (outcome) between 2013 and 2016 were obtained. The Karlson-Holm-Breen mediation method was applied. A total of 35,744 participants were included (54.0% women). The mean age at baseline was 73.1 ± 5.5 y for men and 73.2 ± 5.5 y for women. A total of 1,776 participants (5.0%) had dementia during the follow-up period. There was a significant total effect of the number of teeth on the onset of dementia (hazard ratio, 1.14; 95% CI, 1.01-1.28). Controlling for nutritional and social mediators, the effect of the number of teeth was reduced to 1.10 (95% CI, 0.98-1.25), leaving an indirect effect of 1.03 (95% CI, 1.02-1.04). In the sex-stratified analysis, the proportion mediated by weight loss was 6.35% for men and 4.07% for women. The proportions mediated by vegetable and fruit intake and homeboundness were 4.44% and 4.83% for men and 8.45% and 0.93% for women, respectively. Furthermore, the proportion mediated by social networks was 13.79% for men and 4.00% for women. Tooth loss was associated with the onset of dementia. Nutritional and social factors partially mediated this association.

Primary solitary fibrous tumour of the prostate: A case report and literature review.

INTRODUCTION: Solitary fibrous tumour (SFT) is a rare mesenchymal tumour with intermediate malignant potential. Although this tumour arises in several sites, prostatic SFT is an extremely rare neoplasm and may prove confusing owing to the lack of clinical experience because of tumour rarity. The diagnosis may be further difficult because SFTs can manifest positive immunoreactivity for CD34 and progesterone receptor, which are known markers of prostatic stromal tumours. Herein, we describe a case of prostatic SFT that was difficult to differentiate from a prostatic stromal tumour of uncertain malignant potential because of positive immunoreactivity to CD34 and progesterone receptor. CASE REPORT: A 40-year-old Japanese man presented with lower abdominal pain. Computed tomography revealed a prostatic mass; furthermore, prostate core needle biopsy revealed proliferating bland spindle cells, without necrosis or prominent mitoses. Tumour cells were positive for CD34 and progesterone receptor on immunohistochemical analysis; thus, a prostatic stromal tumour of uncertain malignant potential was initially suspected. However, as the tumour cells showed positive immunoreactivity for STAT6, the final diagnosis was an SFT of the prostate. The patient underwent tumour resection, and at the 6-month postoperative follow-up, neither local recurrence nor distant metastasis occurred. CONCLUSION: For an accurate diagnosis of an SFT of the prostate, STAT6 immunohistochemistry should be conducted for all mesenchymal tumours of the prostate. When STAT6 immunohistochemical analysis is unfeasible, pathologists should be aware that the morphological and immunohistochemical characteristics of SFT variable from case to case and diagnose with combined analysis of several immunohistochemical markers.

Effect of Copayment on Dental Visits: A Regression Discontinuity Analysis.

Despite their prevalence and burdens, oral diseases are neglected in universal health coverage. In Japan, a 30% copayment (out of pocket) by the user and a 70% contribution by Japan's universal health insurance (JUHI) are required for dental and medical services. From the age of 70 y, an additional 10% is offered by JUHI (copayment, 20%; JUHI, 80%). This study aimed to investigate the effect of cost on dental service use among older adults under the current JUHI system. A regression discontinuity quasi-experimental method was used to investigate the causal effect of the JUHI discount policy on dental visits based on cross-sectional data. Data were derived from the 2016 Japan Gerontological Evaluation Study. This analysis contained 7,161 participants who used JUHI, were aged 68 to 73 y, and responded to questions regarding past dental visits. Analyses were controlled for age, sex, number of teeth, and equalized household income. Mean ± SD age was 72.1 ± 0.79 y for the discount-eligible group and 68.9 ± 0.78 y for the noneligible group. During the past 12 mo, significantly more discount-eligible participants had visited dental services than noneligible participants (66.0% vs. 62.1% for treatment visits, 57.7% vs. 53.1% for checkups). After controlling for covariates, the effect of discount eligibility was significant on dental treatment visits (odds ratio [OR], 1.36; 95% CI, 1.32 to 1.40) and dental checkups (OR, 1.49; 95% CI, 1.44 to 1.54) in the regression discontinuity analysis. Similar findings were observed in triangular kernel-weighted models (OR, 1.38 [95% CI, 1.34 to 1.44]; OR, 1.52 [95% CI, 1.47 to 1.56], respectively). JUHI copayment discount policy increases oral health service utilization among older Japanese. The price elasticity for dental checkup visits appears to be higher than for dental treatment visits. Hence, reforming the universal health coverage system to improve the affordability of relatively inexpensive preventive care could increase dental service utilization in Japan.

High-throughput powder diffraction measurement system consisting of multiple MYTHEN detectors at beamline BL02B2 of SPring-8.

In this study, we developed a user-friendly automatic powder diffraction measurement system for Debye-Scherrer geometry using a capillary sample at beamline BL02B2 of SPring-8. The measurement system consists of six one-dimensional solid-state (MYTHEN) detectors, a compact auto-sampler, wide-range temperature control systems, and a gas handling system. This system enables to do the automatic measurement of temperature dependence of the diffraction patterns for multiple samples. We introduced two measurement modes in the MYTHEN system and developed new attachments for the sample environment such as a gas handling system. The measurement modes and the attachments can offer in situ and/or time-resolved measurements in an extended temperature range between 25 K and 1473 K and various gas atmospheres and pressures. The results of the commissioning and performance measurements using reference materials (NIST CeO2 674b and Si 640c), V2O3 and Ti2O3, and a nanoporous coordination polymer are presented.

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.

Nutritional status and dysphagia risk among community-dwelling frail older adults.

OBJECTIVES: Although the presence of dysphagia is a key determinant of nutritional status among older adults, few studies have focused on the association between malnutrition and dysphagia risk in community-dwelling frail older adults. This study estimated the prevalence of malnutrition and quantified the association between malnutrition and dysphagia risk among community-dwelling older Japanese adults requiring long-term care. DESIGN: Cross-sectional study. SETTING: This study was conducted with the cooperation of the Japan Dental Association and local dental associations in all 47 prefectures from January to February 2012. PARTICIPANTS: Individuals aged ≥65 years capable of oral nutrient intake who were living at home and receiving home dental care and treatment. MEASUREMENTS: Individual demographic characteristics and factors associated with health loss-related functional decline were obtained through interviews by home-visit dentists and self-administered questionnaires. Nutritional status and dysphagia risk were evaluated using the Mini Nutritional Assessment Short Form and the Dysphagia Risk Assessment for the Community-dwelling Elderly. RESULTS: Among 874 respondents (345 men and 529 women), 24.6% were malnourished, 67.4% were at risk of malnutrition, and 8.0% were well nourished. Dysphagia risk was related to an increased likelihood of malnutrition at an old age, even after adjusting for covariates (PR = 1.30, 95% CI = 1.01-1.67). CONCLUSION: Malnutrition is highly prevalent among community-dwelling frail older adults, and dysphagia risk is independently associated with malnutrition. Dysphagia may be an important predictor of malnutrition progression in aged populations.

Structural, magnetic and electronic state characterization of L1 0-type ordered FeNi alloy extracted from a natural meteorite.

To understand the hard magnetism of L10-type ordered FeNi alloy, we extracted the L10-FeNi phase from a natural meteorite, and evaluated its fundamental solid-state properties: sample composition, magnetic hysteresis, crystal structure and electronic structure. We executed multidirectional analyses using scanning electron microscopy with an electron probe micro-analyzer (SEM-EPMA), a superconducting quantum interference device (SQUID), x-ray diffraction (XRD) and magnetic circular dichroism (MCD). As a result, we found that the composition was Fe: 50.47 ± 1.98 at.%, Ni: 49.60 ± 1.49 at.%, and an obvious superlattice peak is confirmed. The estimated degree of order was 0.608, with lattice constants a = b = 3.582 Å and c = 3.607 Å. The obtained coercivity was more than 500 Oe. MCD analysis using the K absorption edge suggests that the magnetic anisotropy could originate from the orbital magnetic moment of 3d electrons in Fe; this result is consistent with that in a previous report obtained with synthetic L10-FeNi.

Prevalence and growth kinetics of Shiga toxin-producing Escherichia coli (STEC) in bovine offal products in Japan.

Recent epidemiological data suggest a link between the consumption of bovine offal products and Shiga toxin-producing Escherichia coli (STEC) infection in Japan. This study thus examined the prevalence of STEC in various types of these foods. PCR screened 229 bovine offal products for the presence of Shiga toxin (stx) gene. Thirty-eight (16·6%) samples were stx positive, of which eight were positive for rfbE(O157) and three were positive for wzy(O26). Four O157 and one O26 STEC isolates were finally obtained from small-intestine and omasum products. Notably, homogenates of bovine intestinal products significantly reduced the extent of growth of O157 in the enrichment process compared to homogenates of beef carcass. As co-incubation of O157 with background microbiota complex from bovine intestinal products in buffered peptone water, in the absence of meat samples, tended to reduce the extent of growth of O157, we reasoned that certain microbiota present in offal products played a role. In support of this, inoculation of generic E. coli from bovine intestinal products into the homogenates significantly reduced the extent of growth of O157 in the homogenates of bovine intestinal and loin-beef products, and this effect was markedly increased when these homogenates were heat-treated prior to inoculation. Together, this report provides first evidence of the prevalence of STEC in a variety of bovine offal products in Japan. The prevalence data herein may be useful for risk assessment of those products as a potential source of human STEC infection beyond the epidemiological background. The growth characteristic of STEC O157 in offal products also indicates the importance of being aware when to test these food products.

Oral health and cancer, cardiovascular, and respiratory mortality of Japanese.

Cardiovascular diseases, cancer, and respiratory disease are major causes of death in developed countries. No study has simultaneously compared the contribution of oral health with these major causes of death. This study examined the association between oral health and cardiovascular diseases, cancer, and respiratory mortality among older Japanese. Self-administered questionnaires were mailed to participants in the Aichi Gerontological Evaluation Study (AGES) Project in 2003. Mortality data were analyzed for 4425 respondents. Three categories of oral health were used: 20 or more teeth, 19 or fewer teeth and eat everything, 19 or fewer teeth and eating difficulty. Sex, age, body mass index (BMI), self-rated health, present illness, exercise, smoking, alcohol, education, and income were used as covariates. During 4.28 years' follow-up, 410 people died, 159 from cancer, 108 of cardiovascular diseases, and 58 of respiratory disease. Multivariate adjusted Cox proportional hazard models showed that, compared with the respondents with 20 or more teeth, respondents with 19 or fewer teeth and with eating difficulty had a 1.83 and 1.85 times higher hazard ratio for cardiovascular disease mortality and respiratory disease mortality, respectively. There was no significant association with cancer mortality. Oral health predicted cardiovascular and respiratory disease mortality but not cancer mortality in older Japanese.

Association between caregiver behaviours to prevent vertical transmission and dental caries in their 3-year-old children.

BACKGROUND: It has been suggested that oral organisms in children are mainly those transmitted from their mothers. That may account for the relationship between caries levels in children and their parents. However, few studies have investigated the effect of trying to prevent vertical transmission of oral organisms on dental caries levels in children, and the findings in the studies are controversial. The aim of this study was to investigate the association between measures to prevent vertical transmission of oral organisms and the caries experience in 3-year-old children. METHODS: Data were collected from dental examinations for 3-year-old children and a self-administered questionnaire for their caregivers. Absence of maternal sharing of utensils and mouth-to-mouth feeding between caregivers and children was used as the variable about behaviour to prevent vertical transmission of oral organisms. Sex, age in months, dietary behaviour, oral health behaviour and sociodemographic factors were used as covariates. RESULTS AND CONCLUSION: Data for 3,035 children (73.5% of the subjects) were analysed. Caregivers who practised vertical transmission prevention tended to have better oral health behaviours. Multivariate logistic regression analysis did not show any significant association between behaviour to prevent vertical transmission and caries experience (OR = 1.10, 95% CI = 0.86-1.41). This study suggests that caregiver behaviour to prevent vertical transmission was not effective in reducing levels of childhood caries.

The association between neighborhood social capital and self-reported dentate status in elderly Japanese--the Ohsaki Cohort 2006 Study.

OBJECTIVES: Little is known about the influence of social capital on dental health. The aim of the present cross-sectional study was to determine the association between neighborhood social capital, individual social networks and social support and the number of remaining teeth in elderly Japanese. METHODS: In December 2006, self-administered questionnaires were sent to 31,237 eligible community-dwelling individuals (response rate: 73.9%). Included in the analysis were 21,736 participants. Five neighborhood social capital variables were calculated from individual civic networks, sports and hobby networks, volunteer networks, friendship networks and social support variables. We used multilevel logistic regression models to estimate the odds ratio (OR) of having 20 or more teeth according to neighborhood social capital variables with adjustment for sex, age, individual social networks and social support, educational attainment, neighborhood educational level, dental health behavior, smoking status, history of diabetes and self-rated health. RESULTS: The average age of the participants was 74.9 (standard deviation; 6.6) years, and 28.5% of them had 20 or more teeth. In the univariate multilevel model, there were statistically significant associations between neighborhood sports and hobby networks, friendship networks and self-reported dentate status. In the multivariable multilevel model, compared with participants living in lowest friendship network neighborhoods, those living in highest friendship network neighborhoods had an OR 1.17 (95% confidence interval, 1.04-1.30) times higher for having 20 or more teeth. CONCLUSIONS: There is a significant association between one network aspect of neighborhood social capital and individual dentate status regardless of individual social networks and social support.

Duration of norovirus excretion and the longitudinal course of viral load in norovirus-infected elderly patients.

To prevent dissemination of norovirus in semiclosed environments such as aged-care facilities, it is important to know the period of infectivity in norovirus-infected individuals. We recruited 13 elderly patients aged 60-98 years with norovirus gastroenteritis (11 residents in aged-care facilities and two healthy adults) for this study, and measured the viral loads for norovirus in a total of 63 follow-up faecal samples using a real-time quantitative polymerase chain reaction assay. The average period of norovirus excretion was 14.3 days (range: 9-32 days; median: 13 days). All of the follow-up samples collected between 7 and 10 days after the onset of symptoms tested positive. Viral loads in samples collected between 14 and 18 days after the onset of symptoms were divided into three groups: those testing negative, those with <10(4) copies/g stool, and those with >10(4) copies/g stool. Stools from the group with <10(4) copies/g stool were found to be negative for norovirus up to 21-24 days after the onset of symptoms; however, the group with >10(4) copies/g stool showed prolonged norovirus excretion (up to 32 days) in stools. Although the period of infectivity of excreted viruses has not yet been clarified, these results suggest that careful attention should be taken for at least 14 days after the onset of symptoms and that the measurement of viral load in stools around 16 days after onset might be a useful method for following the course of viral shedding for each patient infected with norovirus.

Evaluation of nutrient loads from a mountain forest including storm runoff loads.

Water quality and flow rates at a weir installed on the end of Aburahi-S Experimental Watershed (3.34 ha) were measured once a week from 2001 to 2003 and in appropriate intervals from 30 min to 6 h during five storm runoff events caused by each rainfall from 8 mm to 417 mm. The average annual loads of total nitrogen (TN) and total phosphorus (TP) were calculated to be 19.0 and 0.339 kg ha(-1) y(-1) from the periodical data by using the integration interval-loads method (ILM), which did not properly account for storm runoff loads. Three types of L(Q) equations (L = aQ(b)) were derived from correlations between loading rates L and flow rates Q obtained from the periodic observation and from storm runoff observation. L(Q) equation method (LQM), which was derived from the storm runoff observation and allowed for the hysteresis of discharge of materials, gave 9.68 and 0.159 kg ha(-1) y(-1), respectively, by substitution of the sequential hourly data of flow rates. L(R) equation (L = c(R - r)d) was derived from the correlations between the loads and the effective rainfall depth (R - r) measured during the storm runoff events, and L(R) equation method (LRM) calculated 9.83 +/- 1.68 and 0.175 +/- 0.0761 kg ha(-1) y(-1), respectively, by using the rainfall data for the past 16 years. The atmospheric input-fluxes of TN and TP were 16.5 and 0.791 kg ha(-1) y(-1).

Magnetic-field switching of crystal structure in an orbital-spin-coupled system: MnV2O4.

We studied the magnetic and structural properties of spinel MnV2O4, which has S=5/2 spin with no orbital degrees of freedom on the Mn2+ site and S=1 spin and three orbital degrees of freedom on the V3+ site. We found that the ferrimagnetic ordering at TN=56.5K and the structural phase transition at Ts=53.5K are closely correlated in this compound and found a switching of crystal structure between cubic and tetragonal phases by the magnetic field. This phenomenon can be explained by the coupling between orbital and spin degrees of freedom in the t2g states of the V site.

Vibrio vulnificus septicaemia in Japan: an estimated number of infections and physicians' knowledge of the syndrome.

Questionnaire surveys were implemented to study the incidence and physicians' knowledge of Vibrio vulnificus infections in Japan. Registered emergency physicians were selected by stratified random sampling for a questionnaire survey. A total of 235 out of 386 physicians (61%) responded to the questionnaire and 12 V. vulnificus septicaemia cases were reported from 10 respondents. The annual estimated number of V. vulnificus septicaemia was calculated as 425 (95 % CI 238-752). The study also revealed that only 15.7 % (95 % CI 11.3-21.0) of responding physicians had a basic knowledge of V. vulnificus infection. Education for both physicians and people in the high-risk group for developing the infection (e.g. immunocompromised, chronic liver disease) will be necessary for the prevention, early diagnosis and appropriate treatment of the disease.