119 research outputs found
Presence of Cell Wall Lytic Enzyme in Stable Staphylococcal L-Form
The stable L-form cells derived from Staphylococcus aureus 209P were examined for the presence of cell wall lytic enzymes. The enzyme preparations from cells and culture fluid of the parent strain lysed both Micrococcus lysodeikticus cells and S. aureus cells, whereas the enzyme preparations from the L-form lysed M. lysodeikticus cells but not S. aureus cells. Lipoteichoic acid, which has been reported to be a regulator of the lytic enzyme, inhibited both enzyme preparations from the parent strain and the L-form. However, the susceptibility of the enzyme preparation from the L-form to lipoteichoic acid was lower than that from the parent strain
Penicillin Resistance of Pseudomonas aeruginosa Clinical Isolates from Urinary Tract Infections
One hundred and thirteen clinical isolates of Pseudomonas aeruginosa from urinary tract infections were tested for their mechanisms of resistance to penicillins. Ninety-eight percent and 100.0% of the strains were resistant (MIC≧100 μg/ml) to ampicillin and penicillin G, respectively, while only 5.3% were resistant to piperacillin. Low permeability of the outer membrane, and penicillinase production were involved in their resistance mechanisms. Peptidoglycan synthesis in ether-treated cells of two representative strains was inhibited by ampicillin and piperacillin at the concentrations markedly lower than that for penicillin G
東濃地区における環境水中トリチウム濃度の長期観測
A deuterium plasma experiment is being planned at the Large Helical Device (LHD) at the National Institute for Fusion Sciences (NIFS). To delineate the regional background tritium concentration level before initiation of the experiment, we evaluated tritium concentrations in environmental water samples (river water, pond water, well water, tap water, and rainwater) collected at Tono area, Japan since 1982. Tritium concentrations in environmental water samples ranged widely from N.D. (below the instrumental detection limit of 0.27 Bq L−1) to a maximum of 4.39 Bq L−1. Tritium concentrations at 9 continuous monitoring locations over the 15 years ranged from N.D. to 1.36 Bq L−1. This regional background concentration range will be used to evaluate environmental assessments after the initiation of the deuterium plasma experiment in LHD
Immunohistochemical Features of Primary Pure Squamous Cell Carcinoma in the Thyroid: An Autopsy Case
Primary squamous cell carcinoma (SCC) in the thyroid is extremely rare and has been reported in < 1% of all thyroid cancer cases. Primary SCC in the thyroid was thought to be a transitional form derived from adenocarcinomas; therefore, the majority of reported cases have focused on the conjunction with other histological adenocarcinomas. A 73-year-old male presented to our hospital with bilateral vocal fold palsy and an anterior neck mass. Ultrasound sonography revealed a bulky tumor in the thyroid and bilateral cervical lymphadenopathy. We performed fine-needle aspiration cytology from the thyroid tumor, which revealed SCC. Positron emission tomography/computed tomography showed distant metastases in the lungs, mediastinal lymph nodes, and vertebra. We diagnosed the patient as having stage IVC SCC in the thyroid and administered weekly paclitaxel. Four and a half months after treatment initiation, the tumor progression resulted in aspiration pneumonia, which proved fatal. We performed an autopsy in accordance with the patient’s wishes. Pathological findings revealed that all carcinomas in the thyroid, cervical lymph nodes, and lungs were pure SCCs. Immunohistochemical examinations for PAX8, thyroglobulin, and TTF-1 were all negative. Differentiated thyroid carcinomas have 3 major positive markers – PAX8, thyroglobulin, and TTF-1 –, and PAX8 is also sometimes positive for SCC in the thyroid. PAX8 positivity of SCC in the thyroid might, however, be associated with conjunction with other histological adenocarcinomas such as papillary or follicular thyroid carcinoma; therefore, pure SCC in the thyroid might be negative for PAX8
Dok-1 and Dok-2 are negative regulators of lipopolysaccharide-induced signaling
Endotoxin, a bacterial lipopolysaccharide (LPS), causes fatal septic shock via Toll-like receptor (TLR)4 on effector cells of innate immunity like macrophages, where it activates nuclear factor κB (NF-κB) and mitogen-activated protein (MAP) kinases to induce proinflammatory cytokines such as tumor necrosis factor (TNF)-α. Dok-1 and Dok-2 are adaptor proteins that negatively regulate Ras–Erk signaling downstream of protein tyrosine kinases (PTKs). Here, we demonstrate that LPS rapidly induced the tyrosine phosphorylation and adaptor function of these proteins. The stimulation with LPS of macrophages from mice lacking Dok-1 or Dok-2 induced elevated Erk activation, but not the other MAP kinases or NF-κB, resulting in hyperproduction of TNF-α and nitric oxide. Furthermore, the mutant mice showed hyperproduction of TNF-α and hypersensitivity to LPS. However, macrophages from these mutant mice reacted normally to other pathogenic molecules, CpG oligodeoxynucleotides, poly(I:C) ribonucleotides, or Pam3CSK4 lipopeptide, which activated cognate TLRs but induced no tyrosine phosphorylation of Dok-1 or Dok-2. Forced expression of either adaptor, but not a mutant having a Tyr/Phe substitution, in macrophages inhibited LPS-induced Erk activation and TNF-α production. Thus, Dok-1 and Dok-2 are essential negative regulators downstream of TLR4, implying a novel PTK-dependent pathway in innate immunity
2-Methacryloyloxyethyl phosphorylcholine (MPC)-polymer suppresses an increase of oral bacteria: a single-blind, crossover clinical trial
Objectives The biocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC)-polymers, which mimic a biomembrane, reduce protein adsorption and bacterial adhesion and inhibit cell attachment. The aim of this study is to clarify whether MPC-polymer can suppress the bacterial adherence in oral cavity by a crossover design. We also investigated the number of Fusobacterium nucleatum, which is the key bacterium forming dental plaque, in clinical samples.
Materials and methods This study was a randomized, placebo-controlled, single-blind, crossover study, with two treatment periods separated by a 2-week washout period. We conducted clinical trial with 20 healthy subjects to evaluate the effect of 5% MPC-polymer mouthwash after 5 h on oral microflora. PBS was used as a control. The bacterial number in the gargling sample before and after intervention was counted by an electronic bacterial counter and a culture method. DNA amounts of total bacteria and F. nucleatum were examined by q-PCR.
Results The numbers of total bacteria and oral streptcocci after 5 h of 5% MPC-polymer treatment significantly decreased, compared to the control group. Moreover, the DNA amounts of total bacteria and F. nucleatum significantly decreased by 5% MPC-polymer mouthwash.
Conclusions We suggest that MPC-polymer coating in the oral cavity may suppress the oral bacterial adherence.
Clinical relevance MPC-polymer can be a potent compound for the control of oral microflora to prevent oral infection
Enhancement activity of QS autoinducer analog
In this study, we have investigated the effects of the newly synthesized analog of Pseudomonas aeruginosa quorum-sensing autoinducer named AIA-1 (autoinducer analog) against antibiotic-resistant bacteria. In vitro susceptibility and killing assays for P. aeruginosa PAO1ΔoprD mutant and clinical isolates were performed by using antibiotics and AIA-1. In an in vivo assay, a luminescent carbapenem-resistant strain derived from PAO1ΔoprD was injected into neutropenic ICR mice and bioluminescence images were acquired after the treatment with antibiotics and AIA-1. Additionally, we investigated the effects of the combination use against carbapenem- resistant Enterobacteriaceae (CRE). Using killing assays in P. aeruginosa, the survival rates in the presence of antibiotics and AIA-1 significantly decreased in comparison with those with antibiotics alone. Furthermore, dual treatment of biapenem and AIA-1 was more effective than biapenem alone in a mouse infection model. AIA-1 did not change the MICs in P. aeruginosa, suggesting that AIA-1 acts on the mechanism of antibiotic tolerance. Conversely, the MICs of antibiotics decreased in the presence of AIA-1 in some CRE strains, indicating that AIA-1 may require additional mechanism to act on CRE. In conclusion, AIA-1 may be a potent drug for clinical treatment of infections caused by antibiotic-resistant bacteria
Effect on Blood Pressure of Daily Lemon Ingestion and Walking
Background. Recent studies suggest that the daily intake of lemon (Citrus limon) has a good effect on health, but this has not been confirmed in humans. In our previous studies, it was observed that people who are conscious of their health performed more lemon intake and exercise. An analysis that took this into account was required. Methodology. For 101 middle-aged women in an island area in Hiroshima, Japan, a record of lemon ingestion efforts and the number of steps walked was carried out for five months. The change rates (Δ%) of the physical measurements, blood test, blood pressure, and pulse wave measured value during the observation period were calculated, and correlations with lemon intake and the number of steps walked were considered. As a result, it was suggested that daily lemon intake and walking are effective for high blood pressure because both showed significant negative correlation to systolic blood pressure Δ%. Conclusions. As a result of multiple linear regression analysis, it was possible that lemon ingestion is involved more greatly with the blood citric acid concentration Δ% and the number of steps with blood pressure Δ%, and it was surmised that the number of steps and lemon ingestion are related to blood pressure improvement by different action mechanisms
Public transportation and the disabled person
機能訓練事業として実施している「生活リハビリ教室」の教室生208名を対象に,公共交通機関を利用して外出するために障害になっている要因を明らかにする目的で,郵送法による自記式アンケート調査を行った。回答は125名(60.1%)からあった。外出経験がある者は67名(53.6%)で外出経験がない者が58名であった。外出時に付添いが必要と思っている者は,外出経験のない者に多かった。公共交通機関を利用しての外出を阻害している要因には,乗り物の昇降口に段差があることや早く発車して危険である,また周囲の人に介助を依頼しにくいことなどが挙げられている。身体機能障害者が外出できない理由は個人によって異なってはいるが,地域社会に身体機能障害者を受け入れる環境を整えていく必要がある。A survey was distributed by mail to disabled people who received functional training in 1997. Of 208 questionnaires sent, 125 (60.1%) were returned. Sixty-seven (53.6%) of the respondents had experience traveled outside. People who participate in functional trainning for disability hope to have an attendant to accompany them when traveling. One primary factor that hinders traveling outside and using public transportation is that they cannot ask for help because of shyness. Another factor is the construction of entrances (e.g.,bumps) for vehicles which cannot be traversed easily. Reasons differed among those who had traveled outside and those who had not. It is necessary to prepare an environment (e.g., public transportationto) for ease of use for disabled persons in regional communities
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