Molecular analysis for bacterial contamination

Bacterial contamination in dental unit waterlines (DUWLs) was evaluated by molecular techniques in addition to the conventional culture method. Water samples (n=8) from DUWLs were investigated for heterotrophic bacteria by culture method using R2A agar. The selected bacterial antibiotic-resistance genes and Legionella species-specific 16SrDNA were identified by PCR. The profiles of bacterial contamination in DUWLs were further identified by PCR-DGGE. In this study, no antibiotic-resistant or Legionella genes were detected. Polycyclic aromatic hydrocarbon-degrading bacterium, Novosphingobium sp. was the most prevalent in DUWLs. Conventional PCR and PCR-DGGE were shown to be potentially useful for monitoring of bacterial contamination in DUWLs

Bacterial-contamination Monitoring

Bacterial contamination of dental unit waterlines (DUWLs) was evaluated by using ATP-bioluminescence analysis and conventional culture method. Water samples (n=44) from DUWLs were investigated for heterotrophic bacteria by culture on R2A agar, which ranged from 1.4×103 to 2.7×105 CFU/mL. The ATP-bioluminescence results for DUWL samples were ranged from 6 to 1189 RLU and obtained within one minutes. These results were well correlated with the culture results (r=0.727-0.855). We conclude that differences in the bacterial contamination of each water supply were confirmed by the ATP-bioluminescence assay. This method would be potentially useful for rapid and simple monitoring of DUWL bacterial contamination

Use of ATP bioluminescence to survey the spread of aerosol and splatter during dental treatment

Aerosol and splatter produced during dental treatment (ultrasonic scaling and professional mechanical tooth cleaning) are potential sources of infection. Contamination patterns on the operators’ masks, goggles, chests and gowned right arms, and on the patients’ goggles, before and after dental treatment were investigated by using ATP bioluminescence analysis. Contamination on every surface tested increased significantly after dental treatment. Maximum contamination was found on patients’ goggles. Aerosol and splatter produced during dental treatment thus have the potential to spread infection to operators and patients. ATP bioluminescence is a useful tool for monitoring surface contamination

The Comparative Study of Dysphagia Screening Tests

【目的】本研究では，嚥下スクリーニングテストの包括的な評価方法の有用性を検討した． 【方法】嚥下障害者3例に対して，嚥下スクリーニングとして単一の項目で標準化されたテストであるRSST とMWST，および包括的評価を行うStandardized Swallowing Assessment（以下，SSA）とThe Toronto Bedside Swallowing Screening Test（以下，TOR-BSST）の4つのテストを用いた評価場面をビデオ撮影し，独自に教則ビデオを作成した．その後，言語聴覚士65名（平均臨床経験年数5.2±3.6年）を対象に，作成した教則ビデオを視聴させた後，アンケート調査を実施した．アンケートの質問は10項目で，嚥下障害のスクリーニングテストにおける ① 簡便性，② 嚥下障害における問題の所在の確認と推測，③安全性，④ 重症度の判定，⑤ 食事形態の決定への活用，⑥ 嚥下訓練につながるアセスメントの可否，⑦嚥下訓練の効果判定，⑧ 嚥下機能の経時的変化，⑨ 嚥下障害の検出力，⑩ 総合的な使い勝手，についての ① から ⑩ 項目で構成され，各質問を「思わない」から「そう思う」までの5 件法で尋ねた．解析方法はKruskal―Wallis 検定を用いて，有意水準5%未満として検討した． 【結果】単一項目で行う評価方法と包括的に行う評価方法との比較では，今回使用したアンケート調査の10項目中7項目（ ②，④，⑤，⑥，⑦，⑧，⑨）において，包括的評価方法の有用性が支持された． 【結論】術者の主観的な評価として，今回調査した4つすべての嚥下スクリーニングテストは総合的に使い勝手がよいと判断され，さらにSSAやTOR-BSSTで用いられる包括的な評価方法は，嚥下障害の問題の所在の確認および推測，嚥下障害の重症度の判定，食事形態の決定への活用，嚥下訓練につながるアセスメントの可否，嚥下訓練の効果判定，嚥下機能の経時的変化を捉えていくことへの活用，嚥下障害の検出力において，RSST やMWST を単一項目で評価する場合よりも有用であることが示唆された．Objective:　In this research, two types (comprehensive evaluation methods and single evaluation methods) of dysphagia screening test were compared effectiveness to confirm more appropriate as the screening test. Methods:　Video recordings were made of 3 patients with dysphagia who underwent single evaluation methods (RSST and MWST) or comprehensive evaluation methods (SSA and TOR-BSST) in dysphagia screening tests. These recordings were then used to create a teaching video movie, which was shown to 65 speech therapists with clinical experience (mean years of experience, 5.2±3.6 years); these therapists were then administered a questionnaire. This questionnaire consisted of 10 items, which covered the following aspects of the dysphagia screening tests: simplicity of the tests, confirmation or inference of the site of dysphagia, their safety, severity evaluation, determination of the food types, determination of their usefulness for assessment of swallowing training, evaluation of the effect of swallowing training, evaluation of the changes in swallowing functions over a period of time, ability to diagnose dysphagia, and usefulness of the tests. A 5-point scale was used to answer each question, and the subjective evaluations of the practitioners who used the 4 tests were analyzed. The Kruskal─Wallis test was used for analysis of the results and a value less than 5% was considered to be significant. Results:　As a result of questionnaire survey, it has become apparent that comprehensive evaluation methods were more appropriate than single evaluation methods as dysphagia screening tests. Conclusion:　The result of this study suggested that effectiveness of comprehensive evaluation methods in dysphagia screening test. It might be contribute for the dysphasic patients to introduce the comprehensive evaluation methods in Japan

Relationship between Oral Function and Food Preferences among Elderly Japanese

【目的】　わが国の高齢化率は上昇を続けており，高齢者の健康寿命への関心も高い．特に食事は楽しみの一つであり，QOL の向上につながる重要因子とされている．咀嚼や嚥下機能が低下すると摂取する食品が制限され，食品嗜好へ影響を与えることが懸念される．しかし，咀嚼機能や嚥下機能など口腔機能と，食品嗜好との関係に着目した研究はみられない．そこで，本研究は，高齢者の咀嚼および嚥下機能と食品嗜好との関連性を明らかにすることを目的とした． 【対象】　徳島大学病院歯科衛生室の65 歳以上の外来受診患者40 名（高齢者群）と，徳島大学歯学部口腔保健学科学生25 名（若年者群）を対象とした． 【方法】　対象者の口腔内状況を確認し，平井らの摂取可能食品質問票の食品35 品目を用いて，食品嗜好スコア（好き/ 嫌い），咀嚼スコア（噛める/ 噛めない），嚥下スコア（飲み込める/ 飲み込めない）に関するアンケートを行い，口腔機能として咀嚼機能はガム咀嚼，前述の咀嚼スコア，嚥下機能は30 秒間の唾液嚥下回数，最大舌圧，水飲みテスト，前述の嚥下スコアを測定し評価した．高齢者群と若年者群の各パラメータにおける2 群間比較を行い，各群における口腔機能と食品嗜好との相関関係を求めて比較した．さらに，食品嗜好スコアと年齢および口腔機能との間における交絡要因の影響を排除するために，ステップワイズ重回帰分散分析を行った． 【結果・考察】　高齢者群のみに30 秒間の唾液嚥下回数と食品嗜好スコアとの間に正の相関が認められた．さらに，多変量解析により，高齢者群のみに嚥下スコアと食品嗜好に，30 秒間の唾液嚥下回数と食品嗜好スコアに正の相関が認められた．高齢者の食品嗜好には，年齢ではなく嚥下機能が影響する可能性が考えられた． 【結論】　高齢者の口腔機能，特に嚥下機能と食品嗜好には関連性があることが示唆された．Objective: Aging affects the sense of taste, and consequently food preferences change in the elderly. However, preferences might be influenced not only by oral sensory function but also by chewing and swallowing function. This study aimed to clarify the relationship between oral function and food preferences among elderly Japanese. Materials and Methods: Forty patients (mean age, 74.2 years) of the dental hygiene clinic in Tokushima University Hospital were enrolled in the elderly group. Twenty-five university students (mean age, 21.4 years) were enrolled in the young group. Food preferences were assessed using a questionnaire on favorite foods among 35 items, based on mastication score (MS). Chewing function was assessed using a xylitol gum-chewing test (Lotte Co., Ltd.) and MS. Swallowing function was assessed using number of saliva swallows in 30 seconds, water swallow test, maximum voluntary tongue pressure (MVTP) and subjective swallowing evaluation (SSE). The Mann-Whitney U test, X2 test, Spearman’s rank correlation coefficient, and stepwise regression analysis were performed for statistical analyses using SPSS ver.21. This study was conducted with the approval of the Ethics Committee of Tokushima University Hospital (Approval number: 1378). Results and Discussion: The scores of the gum-chewing test, MS, number of saliva swallows in 30 seconds, MVTP and SSE of the elderly group were significantly lower than those of the young group. There was a significant correlation between RSST and food preference scores in the elderly group, but not in the young group. Moreover, there were significant correlations between SSE and food preference score, and also between the number of saliva swallows in 30 s and food preference scores in the elderly group with stepwise regression analysis in order to exclude confounding factors between age and oral function. It is considered that the changes of swallowing function with aging affect food preferences among elderly Japanese. Conclusion: Our results indicate that swallowing function influences food preferences among elderly Japanese

Antibacterial Effects of Disulfiram in Helicobacter pylori

Background: Helicobacter pylori infection poses a risk of the occurrence of gastrointestinal diseases, such as gastric cancer. Its incidence rate is significantly reduced by eradication, and thereby, eradication therapy is generally performed. Disulfiram is an oral prescription drug mainly used for the treatment of alcohol dependence. In recent years, reports have been made on its anticancer and antibacterial effects, and thus, it has recently become an interesting subject. This study aimed to examine the antibacterial activity of disulfiram, investigate the presence or absence of its antibacterial activity on H. pylori, and determine whether it could be a new bactericidal drug against drug-resistant H. pylori. Materials and Methods: Drug-sensitive strains of H. pylori and amoxicillin-resistant, clarithromycin-resistant, and metronidazole-resistant strains were used, and a growth inhibition test of H. pylori using disulfiram was performed. Furthermore, the expression of urease, vacuolating cytotoxin A (VacA), and CagA, the virulence proteins of H. pylori, was quantitatively analyzed using the Western blotting method. In addition, for H. pylori used in this study, the 16SrDNA sequence, a ribosomal gene involved in protein production, was analyzed to examine the presence or absence of gene mutation. Results: Disulfiram suppressed the growth of 7 out of 12 H. pylori strains at 1 mu g/mL, and no correlation was observed between their susceptibility/resistance to current eradication antimicrobial drugs and disulfiram resistance. Disulfiram reduced the expression levels of urease, VacA, and CagA proteins. H. pylori, which showed resistance to disulfiram, tended to have fewer gene deletions/insertions in the 16S rDNA sequence; however, no specific mutation was detected. Conclusion: Disulfiram has a bactericidal effect on H. pylori at low concentrations, suggesting that it can be used as a supplement for current H. pylori eradication drugs

Serodiagnosis and Bacterial Genome of Helicobacter pylori Infection

The infection caused by Helicobacter pylori is associated with several diseases, including gastric cancer. Several methods for the diagnosis of H. pylori infection exist, including endoscopy, the urea breath test, and the fecal antigen test, which is the serum antibody titer test that is often used since it is a simple and highly sensitive test. In this context, this study aims to find the association between different antibody reactivities and the organization of bacterial genomes. Next-generation sequences were performed to determine the genome sequences of four strains of antigens with different reactivity. The search was performed on the common genes, with the homology analysis conducted using a genome ring and dot plot analysis. The two antigens of the highly reactive strains showed a high gene homology, and Western blots for CagA and VacA also showed high expression levels of proteins. In the poorly responsive antigen strains, it was found that the inversion occurred around the vacA gene in the genome. The structure of bacterial genomes might contribute to the poor reactivity exhibited by the antibodies of patients. In the future, an accurate serodiagnosis could be performed by using a strain with few gene mutations of the antigen used for the antibody titer test of H. pylori

Relationships between Skeletal Muscle Mass and Strength, and Jaw-Opening Force in Japanese Community-Dwelling Elderly

【目的】要介護高齢者の一要因である骨格筋量の低下や筋力低下は，嚥下関連筋にも影響を及ぼし，摂食嚥下機能を低下させることが疑われる．本研究では，地域在宅高齢者の骨格筋量・骨格筋力と，口腔機能・摂食嚥下機能との関連性を明らかにすることを目的として，調査を実施した． 【対象と方法】対象は，65歳以上の地域在宅高齢者24名（男性3名，女性21名，平均年齢77.0±5.0 歳）とした．骨格筋量は骨格筋指数（以下，SMI）を，骨格筋力は握力を評価項目として用いた．口腔機能・摂食嚥下機能は開口力・オーラルディアドコキネシス（以下，OD）/ タ/ と/ カ/・RSST・MWST を測定し，骨格筋量と骨格筋力との関連性を検討した．各項目の相関関係をスピアマンの順位相関係数にて解析した．その後，有意な関連のあった項目に年齢，性別を加え，重回帰分析（ステップワイズ法）を行った．さらに，握力の値から，筋力健常群と筋力低下群（男性＜ 26 kg，女性＜ 18 kg）の2群に分類し，口腔機能・摂食嚥下機能の各項目について比較した．2群間比較には，マン・ホイットニーのU 検定を用いて統計解析した． 【結果と考察】SMI と開口力，握力と開口力・OD / タ/ に有意な相関関係が認められた（r＝0.578，p＝0.003；r＝0.640，p＝0.001；r＝0.447，p＝0.029）．重回帰分析の結果，開口力に影響を与える因子としてSMI が挙げられた．また，筋力低下群の開口力は，筋力健常群よりも有意に低い値を示した（p＝0.011）．全身の骨格筋量，骨格筋力の低下は，開口力やOD / タ/ の低下に関連する可能性が考えられた． 【結論】地域在宅高齢者の骨格筋量と骨格筋力は，開口力や舌運動機能に関連する可能性が示唆された．Skeletal muscle mass decreasing and muscle weakness can cause long-term care needs for elderly people. The relationship between skeletal muscle status and muscles relevant to oral function has been little reported. Therefore, the aim of the present study was to survey skeletal muscle status, oral function, and the relationship between the two in community-dwelling elderly people. Twenty-four community-dwelling elderly from two elderly associations in N city, T prefecture enrolled in the present survey (3 males, 21 females; mean age, 77.0±5.0 years). Skeletal muscle index (SMI) was used to assess skeletal muscle mass, grasping power to assess skeletal muscle strength. Oral function was evaluated in terms of jaw-opening force, diadochokinesis, the repetitive saliva swallowing test (RSST), and the modified water swallowing test (MWST). Correlations between parameters were analyzed using Spearman’s correlation coefficient. Consequently stepwise regression analysis was performed with jaw-opening force as objective variable and SMI, grasping force, age and sex as explanatory variables. The subjects were divided into two groups according to standards for grasping force: healthy and muscle weakness (male: ＜26 kgw; female: ＜18 kgw). Parameters were statistically compared between the two groups using the Mann-Whitney U test. There were statistical relationships between SMI and jaw-opening force (r＝0.578, p＝0.003), grasping force and jaw-opening force (r＝0.640, p＝0.001), grasping force and the number of diadochokinetic movement of /ta/ (r＝0.447, p＝0.029). As a result of stepwise regression analysis, SMI was a factor that affects jaw-opening force. In the muscle weakness group, jaw-opening force was less than the value in the healthy group ( p＝ 0.011). It is reasonable that an overall decrease in muscle mass would evoke decreases in muscle strength in both the extremities and the jaw-opening muscles. We confirmed significant relationships between skeletal muscle mass, skeletal muscle strength, and oral function (i.e., jaw-opening force and tongue skilled movement) in Japanese community-dwelling elderly

Protective roles of ascorbic acid in oxidative stress induced by depletion of superoxide dismutase in vertebrate cells.

Superoxide dismutases (SODs) are antioxidant proteins that convert superoxide to hydrogen peroxide. In vertebrate cells, SOD1 is mainly present in the cytoplasm, with small levels also found in the nucleus and mitochondrial intermembrane space, and SOD2 is present in the mitochondrial matrix. Previously, the authors conditionally disrupted the SOD1 or SOD2 gene in DT40 cells and found that depletion of SOD1 caused lethality, while depletion of SOD2 led to growth retardation. The observations from previous work showed that the lethality observed in SOD1-depleted cells was completely rescued by ascorbic acid. Ascorbic acid is a water-soluble antioxidant present in biological fluids; however, the exact target for its antioxidant effects is not known. In this study, the authors demonstrated that ascorbic acid offset growth defects observed in SOD2-depleted cells and also lowered mitochondrial superoxide to physiological levels in both SOD1- or SOD2-depleted cells. Moreover, depletion of SOD1 or SOD2 resulted in the accumulation of intracellular oxidative stress, and this increased oxidative stress was reduced by ascorbic acid. Taken together, this study suggests that ascorbic acid can be applied as a nontoxic antioxidant that mimics the functions of cytoplasmic and mitochondrial SODs