Analysis of the linear oscillation dynamics of Fluidyne engines

A Fluidyne engine is a liquid piston Stirling engine that uses thermally induced self-sustained oscillations of water and air that are filled in a looped tube and tuning column. It presents high potential for use as a low-temperature-difference Stirling engine with a simple structure. This study analyzes the linear oscillation dynamics of the Fluidyne from a thermoacoustic point of view, with particular emphasis on the local specific acoustic impedance of the working gas, which is given by the ratio of the complex amplitudes of the pressure and velocity oscillations in the regenerator of the Fluidyne. The frequency dependence of the specific acoustic impedance indicates that the gas in the regenerator region undergoes a thermodynamic cycle equivalent to the Stirling cycle when the oscillation frequency is equal to the natural oscillation frequency of the U-shaped liquid column in the Fluidyne. The analysis of the natural oscillation modes determined two key parameters for the desired specific acoustic impedance: the tuning column length and the connecting position to the loop. Experimental verification was achieved via measurements of the onset temperature ratio and acoustic field of a prototype Fluidyne engine.

SAT0083 PREVALENCE OF DYSPHAGIA AND ASSOCIATED RISK FACTORS IN ELDERLY PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Dysphagia (swallowing disorder) is an important health concern among the elderly that is associated with a poor prognosis [1]. Rheumatic diseases such as dermatomyositis are thought to represent an important risk factor for dysphagia, but few studies have described the association between dysphagia and rheumatoid arthritis (RA), and details on the prevalence of dysphagia in RA patients is not known [2] [3].

Objectives:

The present study aimed to determine the prevalence of dysphagia and associated risk factors among elderly patients with rheumatoid arthritis.

Methods:

We conducted a cross-sectional study including 93 patients with RA and osteoarthritis (OA) over 65 years of age. OA patients were included in the study as healthy controls. Patients with a history of stroke, neuromuscular disease, or head and neck tumors were excluded from the study. From July to November 2019, the water swallowing test (WST) and repetitive saliva swallowing test (RSST) were performed to evaluate the presence or absence of dysphagia in the patients. We also checked oral conditions, hoarseness, temporomandibular joint symptoms, cervical range of motion limitations, and grip strength. In addition, interviews were conducted to investigate swallowing ability and aspiration history. We compared the prevalence of dysphagia between RA and OA patients and explored potential risk factors for dysphagia in RA patients using logistic regression models.

Results:

Our study subjects comprised 63 RA patients (mean age, 73.8 years; 86.5% female) and 30 OA patients (mean age, 75.8 years; 82.3% female). The WST and RSST revealed that RA patients had a significantly higher prevalence of dysphagia than OA patients (23.8% vs 6.7%, p<0.05). While RA patients with dysphagia (n=15) were significantly older and had a longer disease duration than the OA patients, we observed no difference in disease activity or administrated drugs. Of the RA patients with dysphagia, 60% reported no previous episodes of aspiration. Increasing age (odds ratio (OR) 3.21, 95% confidence interval (CI) 1.06-4.56), cervical range of motion limitations (OR 3.14, 95% CI 1.02-7.24), opening disorder of the jaw (OR 2.26, 95% CI 1.12-4.86), and decreased grip strength (OR 1.96, 95% CI 1.01-4.15) were identified as factors related to the presence of dysphagia. Coexistence of Sjogren’s syndrome did not significantly affect the prevalence of dysphagia.

Conclusion:

Dysphagia was more prevalent among RA patients than in OA patients, suggesting an association with temporomandibular involvement, cervical disorder, and muscle weakness. Subclinical dysphagia should be assessed and monitored carefully in the clinical course of elderly patients with RA.

References:

[1] KW Altman et al. Consequence of dysphagia in the hospitalized patient: impact on prognosis and hospital resources. Arch Otolaryngol Head Neck Surg. 2010 Aug; 136 (8):784-9.

[2] Gilheaney Ó et al. The Prevalence of Oropharyngeal Dysphagia in Adults Presenting with Temporomandibular Disorders Associated with Rheumatoid Arthritis: A Systematic Review and Meta-analysis. Dysphagia. 2017 Oct; 32 (5):587-600.

[3] Mugii N et al. Oropharyngeal Dysphagia in Dermatomyositis: Associations with Clinical and Laboratory Features Including Autoantibodies. PLoS One. 2016 May 11;11 (5):e0154746.

Disclosure of Interests:

None declared

AB0106 THE SERUM N-ACETYLGLUCOSAMINE CONCENTRATIONS IN RHEUMATOID ARTHRITIS PATIENTS ARE ASSOCIATED WITH JOINT DESTRUCTION AND RELATED METABOLISM MORE THAN INFLAMMATORY CONDITION

Background:

In rheumatoid arthritis (RA) patients, synovitis causes severe articular cartilage damage. N-acetylglucosamine (NAc-Glc) is a component of gluglucosaminoglycans (GAG) such as hyaluronic acid (HA) and keratan sulfate (KS), heparan sulfate (HS). NAc-Glc concentration in plasma is thought to reflect the balance between biosynthesis and destruction of articular cartilage, however, few studies had examined the relationship between plasma NAc-Glc conncentration and RA activity.

Objectives:

NAc-Glc concentrations in RA patients were measured, and association with clinical indicators was assessed.

Methods:

A cross-sectional study was carried out including 60 RA cases. Using N-acetylglucosamine-d3 as standard, the serum of subjects were deproteinized by protein precipitation method with acetonitrile, then concentration of NAc-Glc was measured with high-speed liquid chromatography mass spectrometer (LC-MS / MS). Clinical evaluation items: basic metabolism, presence or absence of exercise habit, Larsen score of knee and wrist joint, therapeutic agents (csDMARDs, biologics and PSL), DAS28, CRP, MMP-3, modified HAQ score (mHAQ). Statically analyzed by Spearman non parametric test.

Results:

The age of 60 RA cases was 59.7±16.4 years, and the duration of the disease was 10.4±8.7 years. Biologics were used in 29 cases (TNF inhibitors in 16 cases, IL-6 inhibitors in 4 cases, Abatacept in 9 cases), MTX in 32 cases, and prednisolone in 15 cases.

Plasma NAc-Glc concentration was 113±41 (ng/dl), DAS28CRP was 3.04±1.2, and mHAQ was 0.863±891. Plasma NAc-Glc concentration showed positive correlation with age (correlation coefficient 0.644), knee joint destruction (0.425), HAQ score (0.340), BUN (0.412), and RF (0.287). Plasma NAc-Glc concentrations also negatively correlated with eGFR (-0.597), MTX use (-0.389), basal metabolism (-0.313), and sex difference (-0.272). There was no correlation between plasma NAc-Glc concentration and body weight, BMI, DAS28, CRP, MMP-3, NTX, serum creatinine, hand joint disease, and transaminase.In this study, plasma NAc-Glc concentration had increased with age, and had have a negative correlation with basal metabolism. Considering these results, it is unlikely that NAc-Glc is released into plasma as a metabolite of synthesis promotion. Further, since NAc-Glc had a negative correlation (-0.389) with MTX as a folic acid inhibitor, it was supposed to be affected by protein synthesis reduction. Because no correlation between NAc-Glc and inflammation or bone metabolism markers was observed, NAc-Glc may represent removal of GAG from the cell membrane (shedding).

In previous GAGs studies, in RA patients, HA, KS, CRP, DAS28, was very associated with arthritis, such as MMP-3.The concentration of NAc-Glc in plasma was more relevant to dysfunctions such as destruction and HAQ due to arthritis such as HAQ than inflammatory indicators such as DAS28, MMP-3 and CRP. It is appearing in the plasma by destruction by shedding, as an index to see the joint destruction, it was presumed to be a better indicator than the GAGs. It was also thought that there is a possibility that MTX affects cartilage substrate metabolism.

Conclusion:

Serum NAc-Glc concentration in rheumatoid arthritis patients may represent cartilage metabolism and joint destruction.

References:

[1]Y.Matsuura. et al.Ann.Rheum.Dis. 2018;77: 1219-1225

[2]T D Spector.et al. Ann.Rheum.Dis. 1992;51: 1134-1137

Disclosure of Interests:

None declared

P1745Clinical characteristics and long-term outcome in patients with helicopter-transported acute coronary syndrome after primary percutaneous coronary intervention

Background

Reducing delay to percutaneous coronary intervention improves functional outcome and reduces long-term mortality. Transportation by helicopter is often quicker than ground transport and thus may improve overall prognosis through reduced ischemic injury and infarction size. Our hospital is located on the medically-depopulated peninsula surrounded by mountain. The journey from the southern tip of the peninsula to the critical care medical center of our hospital take 1.5 hour by a ground ambulance but only 15 minutes by helicopter.

We compared the clinical characteristics and long-term mortality between air and ground transport of ACS patients for primary PCI.

Methods

We conducted an observational cohort study evaluating 2324 patients (mean age 68.5±12.0, male 75.2%) with ACS underwent primary PCI between April 2004 and December 2017 at our hospital.

We divided into three groups according to transportation system type (air, ground, walk-in).

The primary outcome was defined as all-cause death during the long-term follow-up.

Results

Among the entire cohort, 577 patients (24.8%) were transported by air. 1326 (57.1%) patients by ambulance, 421 (18.1%) patients by walk. Baseline characteristics were comparable, but patients by air had a higher prevalence of ST-elevation myocardial infarction.

The rate of long-term mortality was comparable during the median follow up of 6 years (air, 21.1% vs. ground, 21.4% vs. walk-in, 21.1%, respectively, log-rank p=0.72). Multivariate Cox regression analysis showed no significant association between air transportation and long-term mortality (Adjusted HR [vs ground] 1.05, 95% CI 0.60–1.78, p=0.85 and [vs walk-in] 0.94, 95% CI 0.62–1.43, respectively, p=0.77).

Kaplan-Meier curve

Conclusions

The rate of long-term mortality in patients with ACS transported by air was comparable with those transported by ground.

Long-term clinical impact of serum albumin in coronary artery disease patients with preserved renal function

BACKGROUND AND AIMS

Low serum albumin level is reportedly associated with worse clinical outcomes in patients with chronic kidney disease (CKD). However, associations between decreased serum albumin level and outcomes in non-CKD patients with coronary artery disease (CAD) remain unclear. Therefore, we aimed to evaluate the prognostic value of serum albumin concentrations in stable CAD patients with preserved renal function.

METHODS AND RESULTS

We studied 1316 patients with CAD and preserved renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m²) who underwent their first PCI between 2000 and 2011 and had data available for pre-procedural serum albumin. Patients were assigned to quartiles based on pre-procedural albumin concentrations. The incidence of major adverse cardiac events (MACE), including all-cause death and non-fatal myocardial infarction, was evaluated. Mean albumin concentration was 4.1 ± 0.4 g/dL. During the median follow-up of 7.5 years, 181 events occurred (13.8%). Kaplan-Meier curves revealed that patients with decreased serum albumin concentrations showed a higher event rate for MACE (log-rank, p < 0.0001). Using the highest tertiles (>4.3 g/dL) as reference, adjusted hazard ratios were 1.97 (95% CI, 1.12-3.55), 1.77 (95% CI, 0.99-3.25), and 1.19 (95% CI, 0.68-2.15) for serum albumin concentrations of <3.9, 3.9-4.0, and 4.1-4.3 g/dL, respectively. Decreased serum albumin concentration was associated with MACE even after adjusting for other independent variables (HR, 2.21 per 1-g/dL decrease; 95% CI, 1.37-3.56, p = 0.001).

CONCLUSION

Decreased serum albumin concentration independently predicted worse long-term prognosis in non-CKD patients after PCI. Pre-procedural serum albumin concentration could offer a useful predictor for patients with CAD and preserved renal function.

Der f 34, a Novel Major House Dust Mite Allergen Belonging to a Highly Conserved Rid/YjgF/YER057c/UK114 Family of Imine Deaminases

The high prevalence of house dust mite (HDM) allergy is a growing health problem worldwide, and the characterization of clinically important HDM allergens is a prerequisite for the development of diagnostic and therapeutic strategies. Here, we report a novel HDM allergen that belongs structurally to the highly conserved Rid/YjgF/YER057c/UK114 family (Rid family) with imine deaminase activity. Isolated HDM cDNA, named der f 34, encodes 128 amino acids homologous to Rid-like proteins. This new protein belongs to the Rid family and has seven conserved residues involved in enamine/imine deaminase activity. Indeed, we demonstrated that purified Der f 34 had imine deaminase activity that preferentially acted on leucine and methionine. Native Der f 34 showed a high IgE binding frequency as revealed by two-dimensional immunoblotting (62.5%) or ELISA (68%), which was comparable with those of a major HDM allergen Der f 2 (77.5 and 79%, respectively). We also found that Der f 34 showed cross-reactivity with another prominent indoor allergen source, Aspergillus fumigatus This is the first report showing that the Rid family imine deaminase represents an additional important pan-allergen that is conserved across organisms.

Remineralization of primary tooth enamel from individuals with Down syndrome

PURPOSE

The purpose of this study was to clarify the characteristics of primary tooth enamel of Down syndrome patients (DSPs). We examined 9 primary teeth of Down syndrome children and 11 primary teeth of normally developed children to investigate the remineralization processes of enamel by transverse microradiography and X ray micro analyzer (XMA).

METHODS

Mineral loss, lesion depth, maximum mineral value, minimum mineral value, depth of maximum mineral value, and depth of minimum mineral value were used to analyze transverse microradiography (TMR). In addition, we calculated the percentage of enamel remineralization.

RESULTS

All the parameters in the 2 groups showed marked recovery. The results indicated that the Down syndrome group was significantly remineralized the same way as the control group. According to the comparison of mineral content distribution by XMA, the content distribution of magnesium was different between the 2 groups.

CONCLUSION

While recovery through remineralization of primary teeth was similar between Down syndrome children and normally developed children, the mechanism of remineralization process may be different between the 2 groups; consequently, magnesium may be considered as one of the factors affecting recovery.

[An intervention comparison of dental hygienist visits and leaflet mailing for improvement of oral health scores in village residents]

PURPOSE

This study was undertaken to clarify to what extentintervention by dental hygienist visits and leaflet mailing, once or three times a year, increased the dental health scores of Tobishima Village residents in a 3 year period.

METHODS

The oral health status and oral health score (the Oral Salutogenic Score) of 786 residents were examined in May, 2004. Of the total, 446 people had oral health scores equal to or less than 15. They were divided into three groups at random, receiving: dental hygienist visits (visit group); leaflet mailing three times a year (three times mail group); and leaflet mailing only once a year (single mail group). Oral health status and scores were examined a second time by dentists in May, 2007 and average increases of scores over 3 years were calculated for each of the three groups. The Mann-Whitney test and cost-effectiveness analysis were employed for comparisons.

RESULTS

The average increase in oral health score was 46.2 +/- 8.1% for the visit group, 31.2 +/- 4.4% for the three times mail group and 25.0+/-5.2% single mail group over 3 years. The visit group value was significantly higher than the single mail group (P<0.05). Of the resi-dents who had an oral health score equal to or less than 15 points, increase of their oral health score those who received a dental hygienist visit had a higher than the groups who were sent leaflets. With the latter, the greater frequency of leaflet distribution was more effective for increasing the oral health score.

CONCLUSION

It was concluded that visits by dental hygienists are more effective than mailing of leaflets. In addition, mailing 2 or 3 times a year is more effective than once a year.

Genetic polymorphisms in folate pathway enzymes as a possible marker for predicting the outcome of methotrexate therapy in Japanese patients with rheumatoid arthritis

BACKGROUND

Low-dose methotrexate (MTX) therapy is widely used in the treatment of rheumatoid arthritis (RA). Though the difference in response to MTX between patients with RA is large, the factors that contribute to this variability remain unclear.

OBJECTIVE

We aimed to identify those factors with a particular emphasis on the pharmacogenetics of MTX.

METHOD

We evaluated the association of possible factors, including genetic polymorphisms of folate metabolic pathway enzymes, with the cumulative value of C-reactive protein, an index of MTX anti-inflammatory efficacy, in 87 Japanese patients with RA.

RESULTS

Polymorphisms of the reduced folate carrier gene (RFC) G80A and of the gamma-glutamylhydrolase gene (GGH) C-401T were more closely associated (beta = 2.1194, P = 0.0017) than other polymorphisms, with the anti-inflammatory response to MTX.

CONCLUSION

Patients with RA having RFC 80A and GGH-401T alleles were less responsive to MTX than those with RFC 80A and without GGH-401T alleles. Thus, this data may be useful for guiding treatment of RA patients with MTX.

Temporal association of elevated C-reactive protein and periodontal disease in men

BACKGROUND

Most studies on the relationship between serum C-reactive protein (CRP) and periodontal disease have been cross-sectional. In this study, we investigated the temporal association between CRP and periodontal disease by following a large number of subjects for 1 year.

METHODS

We studied 11,162 men in Nagoya, Japan, who had an initial dental examination as part of a complete physical examination and then underwent the same examination 1 year later. For the 4,997 men without periodontal disease at baseline, logistic regression analysis was performed to examine the relationship between baseline CRP and periodontal disease 1 year later, adjusting for age, body mass index, glycosylated hemoglobin A1c level, and smoking status. Similarly, logistic regression analysis was performed to examine the relationship between periodontal disease at baseline and CRP 1 year later for the 10,376 men with normal baseline CRP, adjusting for the same confounding factors.

RESULTS

Among men without high CRP at baseline, periodontal disease at baseline correlated to CRP 1 year later. The odds ratio was 1.336 (95% confidence interval [CI]: 1.115 to 1.674). However, in the men without periodontal disease, no significant correlations were seen with baseline CRP or periodontal disease 1 year later. The odds ratio was 1.163 (95% CI: 0.894 to 1.513).

CONCLUSION

Periodontal disease increased the risk for high serum CRP levels in men after 1 year of follow-up.

Relationships between mandibular cortical bone measures and biochemical markers of bone turnover in elderly Japanese men and women

OBJECTIVE

The aim was to clarify the association between dental panoramic radiography measures of mandibular inferior cortical shape and biochemical markers of bone turnover in elderly men and women.

STUDY DESIGN

Subjects were 80-year-old men (n = 85) and women (n = 153). Mandibular cortical shape and width were evaluated on dental panoramic radiographs. Bone formation and resorption, respectively, were estimated by serum levels of carboxy-terminal propeptide of type I collagen (PICP) and serum type I collagen carboxy-terminal telopeptide (ICTP).

RESULTS

Eroded cortices of the mandible were significantly associated with increased serum PICP levels (P = .005) in women. Lower mandibular cortical width quartiles were also significantly associated with increased serum PICP levels in men (P = .020) and women (P = .006).

CONCLUSIONS

Mandibular inferior cortical measures detected on dental panoramic radiographs may be associated with bone formation rates and be useful in predicting osteoporosis in elderly Japanese men and women.

Is there a gradient by job classification in dental status in Japanese men?

The objective of this study was to assess whether there is a gradient in dental health status by job classification in male Japanese workers. The study subjects were 16,261 male Japanese workers aged 20-69 yr. Jobs were classified into seven job groups. Oral examination was conducted using World Health Organization criteria for decayed, missing or filled teeth (DMFT). Professionals, managers, and office workers had a better oral status than those in service occupations and drivers. Professionals had significantly more natural and sound teeth than those in other job classes. The DMFT of professionals was significantly lower than in workers of other job classes. Professionals had a significantly higher restorative index than did workers of other job classes. The restorative index of office workers was significantly higher than that in managers, skilled workers, salespersons, those in service occupations, and drivers. Drivers were 1.8 times, and those in service occupations 1.3 times, more likely to have one or more carious teeth compared with professionals. Skilled workers, salespersons, those in service occupations, and drivers were 1.3, 1.3, 1.4, and 2.1 times, respectively, more likely to have a missing tooth compared with professionals. Skilled workers, those in service occupations, and drivers were 1.7, 1.9, and 3.1 times, respectively, more likely not to have 20 or more teeth compared with professionals aged 50-69 yr.

Gradients in periodontal status in Japanese employed males

AIM

The objective was to assess whether there was a social gradient in periodontal status by job classification in Japanese male workers.

MATERIAL AND METHODS

Study participants were 15,803 Japanese male workers aged 20-69 years. There were seven groups classified by jobs. Oral examinations were conducted using community periodontal index (CPI).

RESULTS

The percentages of sextants with a CPI score of 3 or 4 of professionals were significantly lower than for other job classes. The gradient also existed for the percentage of sextants with CPI score 4. After adjusting for age, a history of diabetes mellitus and smoking status, those lower on the gradient, namely, drivers, service occupations, salespersons and managers were 2.0, 1.5, 1.4 and 1.4, times, respectively more likely to have one or more sextants with CPI score 3 or 4 compared with professionals. Odds ratios of having more than one or more sextants with CPI score 4 after adjusting for age, clinical history of diabetes mellitus and smoking status for drivers, service occupations, salespersons and managers were 2.1, 1.5, 1.5 and 1.2, respectively, compared with professionals.

CONCLUSIONS

There was a gradient in periodontal status by job classification. Professional and office workers had better periodontal status than salespersons, service occupations and drivers.

Relationship between number of natural teeth in older Japanese people and health related functioning

The objective was to assess the relationship between number of functional occluding natural pairs of teeth and health related functioning in older free living Japanese people using the SF-20. The participants were 107 elderly people aged 80 years. Health related functioning was measured with the SF-20. The numbers of functional occluding natural pairs of teeth (OPs) were calculated and scored as follows: 1, for each pair of anterior teeth and premolars in occlusion. Molar functional natural occluding pairs were scored 2 for each occluding pair. The number of functional occluding pairs was assessed separately as anterior natural occluding pairs (AOPs) and posterior occluding pairs (POPs). There were significant differences in the role functioning subscale of SF-20 between those who were edentulous and those with one to nine natural teeth and 10 or more natural teeth (P = 0.030). Those with one to six AOPs had significantly higher role functioning than the zero AOPs group (P = 0.042). Those with 1-12 POPs also had significantly higher role functioning scores than the zero natural POPs group (P = 0.007). However, there were no significant relationships between number of natural teeth, OPs or AOPs, and POPs on the one hand, and all other subscales of SF-20 on the other hand. The community-dwelling 80-year-old Japanese people in this study had overall good health related functioning. The number of functional occluding pairs of natural teeth, especially POPs, was related with the role functioning subscale of SF-20 but had no significant relationships to the other dimensions of SF-20.

Salutogenic factors that may enhance lifelong oral health in an elderly Japanese population

OBJECTIVES

The objective of this study was to assess which factors affected the maintenance of more than 20 teeth in Japanese patients aged 80 years and older, using a life-course perspective.

SUBJECTS AND METHODS

The oral examination was carried out by dentists. The questionnaire asked about family background, background during various stages of growing up, tooth brushing, snacking, job history, health examination, war experience, number of children, oral health condition and dietary preferences. Some of the questions asked about conditions when they were a primary school student, 20 years old, 40 years old and 60 years old. Multivariable logistic-regression analysis was used to adjust for sex at significant life stages.

RESULTS

The group with mothers who did not prefer sweet food had an approximately four times greater chance of having >or=20 teeth compared with the group with mothers who preferred sweet food. Those participants who did not prefer sweet food themselves were approximately three to five times more likely to be in the >or=20 tooth group compared with those who preferred sweet food at all stages of their life course. Non-smokers and those who quit smoking were three times more likely to be in the >or=20 tooth group than those who smoked throughout the years from 20 to 60 years of age.

CONCLUSIONS

Factors associated with the maintenance of a sufficient number of functioning teeth were: not having a mother with a preference for sweet food, not having a preference for sweet food themselves and not smoking over a long period.

Effects of smoking and drinking habits on the incidence of periodontal disease and tooth loss among Japanese males: a 4-yr longitudinal study

OBJECTIVE

We investigated the risk of periodontal disease and tooth loss, associated with habits of smoking and alcohol consumption, in a longitudinal study.

SUBJECTS AND METHODS

The subjects were 1332 Japanese males, 30-59 yr of age, who were free from periodontal disease at the baseline check-up, and who underwent a second check-up 4 yr later. Periodontal disease was diagnosed using the community periodontal index score, based on the clinical probing of pocket depth (> or = 4 mm). Smoking and alcohol consumption patterns were evaluated using a self-administered questionnaire.

RESULTS

A dose-response relationship was observed between the amount of smoking and the incidence of periodontal disease in each age group. The overall odds ratios (95% confidence intervals), adjusted for age and alcohol, were 1.51 (0.95-2.22), 1.58 (1.13-2.22) and 2.81 (1.96-4.03), among smokers consuming 1-19, 20 or 21 or more cigarettes per day, respectively, with a significant linear trend (p < 0.0001). A similar association was found between smoking and tooth loss, except for the 50-59-yr-old age group. The adjusted odds ratios were 1.26 (0.60-2.64), 2.01 (1.21-2.32) and 2.06 (1.23-3.48), respectively. A significant linear trend between smoking and tooth loss was also observed (p = 0.01). Ex-smokers showed no significant difference compared with nonsmokers. We also found a significant linear trend between alcohol consumption and tooth loss among 30-39-yr-old subjects, while no relationship was observed between alcohol consumption and periodontal disease.

CONCLUSION

Cigarette smoking was found to be an independent risk factor for periodontal disease and tooth loss. Alcohol consumption was a limited risk factor for tooth loss in the younger age group, but was unrelated to periodontal disease. To prevent periodontal disease and tooth loss, health practitioners need to encourage people to stop smoking or not to start.

Relationship between survival rates and numbers of natural teeth in an elderly Japanese population

OBJECTIVES

The objective of this study was to assess whether elderly people with 20 or more natural teeth were more likely to live longer than a cohort with less than 20 teeth.

MATERIALS AND METHODS

Groups of elderly people over 80 years of age (24 males and 35 females) with 20 or more teeth (>or=20 group) were compared with elderly people (24 males and 35 females) with less than 20 teeth (<20 group). Follow-up studies were conducted at regular intervals for 10 years from July 1992 to July 2002. The cumulative survival rate of the >or=20 group (average +/- SE tooth number of teeth - males, 23.9 +/- 0.6; females, 23.8 +/- 0.4) was compared with the <20 group (average number of teeth - males, 3.8 +/- 1.1; females, 2.6 +/- 0.8). The multivariate Cox proportional hazard models with the number of teeth in a group (>or=20 group or <20 group). Smoking status and alcohol intake as covariates were used to adjust the cumulative survival rate.

RESULTS

The male participants in the >or=20 group had a significantly higher cumulative survival rates (p < 0.05) than the <20 group at 18 and 21 months from baseline. There were no significant differences in survival rates between the female groups. Adjusted cumulative survival rate was significantly different at 72, 75 and 78 months between the >or=20 group and <20 group for males but not for females.

CONCLUSION

Having 20 or more natural teeth was associated with increased survival rate in elderly males, but not among the elderly females.

Growth stimulation and inhibition effects of 4-hydroxybenzoic acid and some related compounds on the freshwater green alga Pseudokirchneriella subcapitata

4-hydroxybenzoic acid (4-HBA) exhibited low algal toxicity with the 72-h median inhibition concentration (IC50) of 9.9 mmol/L in the standard growth inhibition test using the freshwater green alga Pseudokirchneriella subcapitata. In contrast, it stimulated the algal growth at lower concentrations ranging from 0.1 to 1.0 mmol/L. Comparative studies with benzoic acid and 2- and 3-hydroxybenzoic acids (2-HBA and 3-HBA) indicated that 2-HBA was the most toxic, giving a 72-h IC50 of 0.172 mmol/L, and 4-HBA was the least toxic and that only 4-HBA had the pronounced growth stimulation activity. In a semicontinuous exposure to 4-HBA (0.15 and 0.3 mmol/L), algae maintained increased cell growth compared with controls during up to 10 times consecutive batch cultures, without any indication of adaptive responses to the growth enhancing effect of 4-HBA. Return to the clean standard medium of the exposed cells resulted in the quick recovery from the stimulant effect. Furthermore, 4-HBA (0.3 mmol/L) was found to diminish the toxicity of 2-HBA (<1.0 mmol/L). The presence of such compounds in the complex mixture might interact with other toxicants to alter the whole toxicity when assessed by the algal growth inhibition test. The effects of 4-HBA on P. subcapitata growth observed in the present study are not expected for planktonic algae in the aquatic environments, because known environmental concentrations are far below the effective concentration range.

Toward elucidating the full spectrum of mite allergens--state of the art

Our research has focused on the molecular design of immunotherapeutic vaccines and the advancement of mite-allergy diagnosis. Here, we describe the research history of the major group 1 and group 2 allergens, immunoelectrophoretic analyses covering the complete spectrum of mite allergens, our results on allergens with distinctive characteristics (a conjunctival congestion-eliciting antigen [LM2], an immunotherapeutic antigen [HM2] with high efficacy and without definite adverse reactions, and a potent T-cell stimulatory antigen [HM1] with secretion of IFN-gamma), the full spectrum and immunochemical properties of the major and other important mite allergens (including our newly described allergens: a pan-allergen [tropomyosin, group 10], a potent T-cell stimulatory allergen [M-177, apolipophorin, group 14] and its peptide fragments Mag1 and Mag3, a moderate IgE-binding allergen [gelsolin/villin, group 16], an EF-hand Ca2+-binding allergen [group 17], and a less IgE-binding allergen [heat shock protein 70]), and prospects for the development of immunotherapeutic and diagnostic agents.

The effect of fluoridation and its discontinuation on fluoride profiles in the alveolar bone of rat

We investigated the effect of fluoridation and its discontinuation on fluoride content in the alveolar portion of the mandible in rats. Drinking water with three different fluoride contents (0, 50, 100 ppmF) was given to rats for three different periods (4, 13 and 25 weeks). Fluoride concentrations were measured in the crest, the middle, and the apical parts of the alveolar bone and in the body of the mandible. Furthermore, after fluoridated drinking water was given to rats for 4 or 13 weeks, distilled water was given to them for 21 or 12 weeks respectively; and the effect of the discontinuation on fluoride profiles was investigated. Layer samples were analyzed by abrasive microsampling. Fluoride and phosphorus concentrations were determined by ion-specific electrode and colorimetric procedures, respectively. There was an increase in fluoride concentrations in the mandible in proportion to the fluoride content in the drinking water and the duration of fluoridation. After fluoridation was discontinued, fluoride concentrations in the surface layers of the mandible presented a decrease. Among the four different parts of the mandible, the upper part of the alveolar bone and the alveolar crest part presented the highest rates of reduction. The relative reduction rate of fluoride concentration was closely related to the duration of discontinuation. The alveolar crest was affected most by the discontinuation of fluoridation, presenting the greatest reduction.

Intestinal obstruction in the terminal ileum caused by an anomalous congenital vascular band between the mesoappendix and the mesentery: report of a case

We report a case of intestinal obstruction caused by a congenital abnormal vascular band in a 17-year-old boy. The patient was admitted with acute colicky abdominal pain, and an emergency laparotomy revealed that the ileum was strangulated by a fibrous band with vessels about 2 mm in diameter and 7 cm in length, extending from the antemesenterium of the terminal ileum to the mesoappendix. The affected intestine was resected with the band and the appendix. Histologically, the fibrous band was composed of loose connective tissue containing arteries, veins, and nerve fibers, suggesting that it was congenital and originated from a remnant of the ventral mesentery in the embryonic period. There have been few reports of intestinal obstruction being caused by a congenital vascular band, especially in patients beyond the pediatric age group.

Intra-oral fluoride retention 3 minutes after fluoride mouthrinsing in 4- to 5-year-old children: effects of fluoride concentration and rinsing time

This study was undertaken to explore the site-specific retention rate and the possibility of shortening fluoride (F) mouthrinsing time of kindergarten children. Fluoride retention after 10-, 20- and 30-second mouthrinsing was determined in 43 kindergarten children aged 4-5 years. Tooth surfaces were sampled by a paper point method. Fluoride concentrations in the salivary film on tooth surfaces increased from primary molars to primary incisors in the maxilla and decreased from primary molars to primary incisors in the mandible. The fluoride solution reached the primary molars even after a 10-second rinse, but F concentrations were higher after 20 s than after 10 s and significantly higher after 30 s than after 10 s. No significant difference was observed between 20 and 30 s. The average total F retained in the mouth was 0.13 mg after 20 s and 0.17 mg after 30 s. It was concluded that 30-second mouthrinsing, which is used extensively in Japanese kindergartens, can be shortened to 20 s.

[Effect of professional oral prophylaxis on the general health perceptions and lifestyles in workers of a worksite]

The present study was undertaken to look at the effect of professional oral prophylaxis on the general health perceptions and lifestyle in workers at a worksite in Aichi-ken. Dental check-ups and three kinds of questionnaires (SAS: The Social Adjustment Scale, MOS: The Medical Outcomes Study and the nutrition) were used in this investigation for three years from 1998. By means of the stratified sampling method, the participants were 265 workers separated into a case and a control group, who work for a pharmaceutical company (201 males, 64 females, average age 35.6 +/- 0.7 yr old). All participants gave their consent to the study. As in the case group, dental hygienists scaled their teeth and gave each of them appropriate advice about their oral health twice in a year. MOS, SAS, nutrition and oral health in the case and control groups were compared with the baseline, third and the final year. The results were as follows; 1) There was significant difference in energy, protein, fat, fish and meats sufficiency rates (p < 0.05) and a higher tendency towards consuming sugar, potassium (K), calcium (Ca), iron (Fe) and Fiber (p < 0.10) in the control group, but there were no significant differences in the other nutrients in the case and control groups. 2) There were significant differences in the number of decayed teeth in the case group, and in the number of filled teeth and decayed teeth in the control group. The gingival condition (CPI = 0) in the case group tended to be higher healthier than the control group, 3) In the MOS questionnaire, the case group was better or not worse in health perceptions scales, pain scales and mental health scales than the control group. 4) In the SAS questionnaire, the case group was better or not worse in the work and the social scales than the control group. It was concluded that oral health, social health and consciousness of health tended to improve by dental intervention.

Blood Test Values and Community Periodontal Index Scores in Medical Checkup Recipients

BACKGROUND

We examined the blood test values of people who received general medical checkups and their Community Periodontal Index (CPI) score.

METHODS

A total of 7,452 persons (5,742 males and 1,710 females), who had general medical and dental checkups, were the subjects of the study. Many were people who worked for companies in and around Nagoya and their family members, ranging in age from 16 to 80 years. The blood test in our study consisted of 37 items used in general blood tests. Partial-mouth recordings were used to measure CPI scores. The highest CPI score for each subject was used for analysis. Odds ratios and confidence interval values were obtained using the Mantel-Haenszel method to analyze the results.

RESULTS

CPI scores of 3 and 4 were related to the test values of high-density-lipoprotein cholesterol, serum iron, white blood cell count, fasting blood sugar, glycosylated hemoglobin A1, glycosylated hemoglobin A1c, and C-reactive protein.

CONCLUSION

Blood test values tended to show correlations with CPI scores, more clearly seen in males than in females.

Oral pre-cancer and the associated risk factors among industrial workers in Japan's overseas enterprises in the UK

BACKGROUND

Screening at industries has been advocated as a method of early detection for cancer. This study describes the prevalence of oral pre-cancerous lesions and other mucosal diseases following oral mucosal screening, and associated risk factors among Japanese industrial workers in the UK.

METHODS

Oral mucosal screening was by invitation at 51 industrial locations in the UK. A self-administered questionnaire was used to record socio-behavioural factors and frequency of daily intake of fruits and vegetables.

RESULTS

Four hundred and eighty-four subjects attended for oral mucosal screening (mean age 39.9 +/- 8.3 years) and their mean period of residence in UK was 5.3 +/- 4.5 years. 63.4% examined were male. 31.3% of males and 26.6% of females smoked daily. The gender differences were striking compared with Japan's national rates. A higher proportion of managerial staff was regular heavy (20+ per day) smokers. The intake of more than five portions per day of vegetables and/or fruits during the weekend was significantly higher in females than in males (P = 0.022). One hundred and six subjects (22%) were detected with oral mucosal lesions, including 16 leukoplakia lesions (3.3%) and three with oral lichen planus (1%). The rate of positive detections was higher in managers (7.5%). Odds ratios were estimated by socio-behavioural variables. Among subjects positive for oral leukoplakia, managers accounted for 68.8% (OR 5.26; 95% CI, 1.24-22.29). 87.5% of subjects detected with oral leukoplakia smoked daily and had done so for the past 10 years (OR 28.40; 95% CI, 5.63-143.28). Though regular alcohol drinking was a common feature among male leukoplakia cases, heavy alcohol misuse was not encountered. None reported an intake of five or more portions of fruits or vegetables.

CONCLUSIONS

The Japanese nationals working in managerial positions in the UK and daily regular smokers in the industries visited were found to be at a high risk of oral pre-cancer. Regular dental/oral check up and tobacco education programmes are encouraged for oral cancer/pre-cancer control in industrial settings.

Effects of carbon dioxide pneumoperitoneum on hemodynamics in cirrhotic rats

BACKGROUND

The aim of our study was to investigate the effect of carbon dioxide pneumoperitoneum on systemic and splanchnic hemodynamics in cirrhotic rats.

METHODS

Sprague-Dawley rats (n = 80) were used in this study. Liver cirrhosis was induced by thioacetamide administration intraperitoneally (200 mg/kg body weight, twice a week for 16 weeks). The radioactive microsphere method was used to measure systemic and regional hemodynamic parameters before, 1 h after the start, and 1 h after the release of pneumoperitoneum.

RESULTS

Splanchnic blood flow and cardiac index were significantly depressed during pneumoperitoneum in liver cirrhosis and control groups, but no significant differences were seen between the two groups. In both groups, portal venous inflow decreased and hepatic arterial blood flow increased significantly during pneumoperitoneum. However, during pneumoperitoneum, total hepatic blood flow as a percentage of its value before pneumoperitoneum was lower in cirrhotic rats (71.0%) than in control rats (91.9%) (p <0.05, Mann-Whitney U-test).

CONCLUSIONS

Carbon dioxide pneumoperitoneum markedly decreases total hepatic blood flow in cirrhotic rats due to the impaired hepatic arterial buffer response. Liver function should be carefully controlled in cirrhotic patients after laparoscopic surgery with pneumoperitoneum.

Der f 16: a novel gelsolin-related molecule identified as an allergen from the house dust mite, Dermatophagoides farinae

Allergen from the house dust mite (Dermatophagoides sp.) is a major trigger factor of allergic disorders, and its characterization is crucial for the development of specific diagnosis or immunotherapy. Here we report the identification of a novel dust mite (Dermatophagoides farinae) antigen whose primary structure belongs to the gelsolin family, a group of actin cytoskeleton-regulatory proteins. Isolated mite cDNA, termed Der f 16, encodes 480 amino acids comprising a four-repeated gelsolin-like segmental structure, which is not seen in conventional gelsolin family members. Enzyme immunoassay indicated that recombinant Der f 16 protein, prepared using an Escherichia coli expression system, bound IgE from mite-allergic patients at 47% (8/17) frequency. This is the first evidence that the gelsolin family represents a new class of allergen recognizable by atopic patient IgE.

Mechanism of protection by S-(1,2-dicarboxyethyl)glutathione triester against acetaminophen-induced hepatotoxicity in rat hepatocytes

Treatment with the triester of S-(1,2-dicarboxyethyl)glutathione (DCE-GS) prevented the hepatotoxicity induced by acetaminophen via elevation of the glutathione (GSH) level in rat hepatocytes. This elevation of the GSH level in rat hepatocytes by DCE-GS triester was dose- and time-dependent (2.1-fold in 24 h with 0.5 mm). DCE-GS triester increased the GSH level much more effectively than GSH, DCE-GS, and DCE-GS monoester and diester. Furthermore, the activity of y-glutamylcysteine synthetase (gamma-GCS), the rate-limiting enzyme in GSH biosynthesis, was also increased by DCE-GS triester treatment (1.4-fold in 24 h with 1.0 mm). In contrast, with a rat liver homogenate, DCE-GS increased the y-GCS activity, whereas DCE-GS triester had no effect on this activity. These results suggested that DCE-GS triester, which is transported into hepatocytes much more effectively than DCE-GS and other DCE-GS esters due to its greater lipophilicity, was hydrolyzed to DCE-GS, and then the DCE-GS produced increased the GSH level via activation of gamma-GCS in rat hepatocytes.