194 research outputs found

    Identification of Ornithine-lactam Converted from Arginine in Streptomyces incarnatus NRRL8089

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    Sinefungin is a nucleoside antibiotic, in which a molecule of L-ornithine is linked to the 5' end of adenosine through a C-C bond. The antibiotic was isolated from the culture broth of Streptomyces incarnatus. For the purpose of detecting intermediate of sinefungin biosynthesis, resting cell suspensions were incubated with supplemental L-arginine, and L-ornithine. 50mM Arginine was converted to a compound X that has low polarity. 50mM ornithine was not converted and remained in reaction solution. Compound X was purified using HPLC, and analyzed using (1)H-NMR and FAB-MS. These analyses showed that a compound X is "ornithine-lactam" (Mw=114), which has a structure of circularized ornithine. These results indicated that S. incarnatus has an enzyme that converts arginine to ornithine-lactam. Such an enzyme has never been reported, and suggested that it may be relevant to sinefungin biosynthesis.シネフンギンは抗真菌,抗マラリア活性を有する核酸系抗生物質であり,放線菌 S. incarnatus により生合成される.シネフンギンはアデノシンとオルニチンがCンC結合した構造であり,無細胞抽出液での取り込み実験からLンアルギニンと ATP から生合成されると推測される.Lンアルギニン,Lンオルニチンを S. incarnatus の休止菌体反応系への投与を行いシネフンギン中間体の探索を行った.その結果50ヒアルギニンは24時間以内に低極性化合物へと変換された.一方50ヒオルニチンは変換されず反応液中に残存した.HPLC で化合物を精製し,1HンNMR,FABンMS での分析の結果オルニチン環状モノペプチド,「オルニチンラクタム」(分子量114)であることを明らかにした.この結果は S. incarnatus がアルギニンからオルニチンラクタムへの変換酵素を有する事を示唆する.このような酵素の報告例はこれまでになく,ニ次代謝酵素であることが示唆され,シネフンギン生合成との関連性に興味が持たれる

    On the Mechanical Disintegration of Metal by a Stamp Mill

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    A disintegration experiment was made on some metals of different property by using a stamp mill, which was especially designed by one of the authors for the present work. The relationships between the work and the time, the mechanical property and the size of the material, and between the particle size distribution of the disintegrated product and the disintegrating time, were studied. The microscopic observation was also carried out on the all of the products during disintegration. On the basis of the experimental results the disintegration process and mechanism were considered

    On the Mechanical Pulverizing for Metals by a Specially Designed Eddy Mill

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    A special eddy mill, in which metals are crushed chiefly by shearing due to mutual friction was designed and the crushing experiment for various metals and alloys was performed, and many important results on following subjects were obtained ; 1. Relation between work amount for pulverizing and pulverizing time. 2. Relation between work amount for crushing and particle size of material. 3. Variation in the particle size distribution of mill product for the treating time. 4. Microphotographs of pulverized powders. 5. Oxidation of pulverized powder and temperature rise in pulverizing

    Initiating SGLT2 inhibitor therapy to improve renal outcomes for persons with diabetes eligible for an intensified glucose-lowering regimen: hypothetical intervention using parametric g-formula modeling

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    [Introduction] Sodium–glucose cotransporter 2 (SGLT2) inhibitors are now recommended in guidelines for persons with type 2 diabetes mellitus (T2DM) and at risk of advanced kidney disease as part of the glucose-lowering regimen. [Research design and methods] To explore the optimal threshold at which to initiate SGLT2 inhibitor therapy, we conducted an observational study analyzed under a counterfactual framework. This study used the electronic healthcare database in Japan, comprising data from approximately 20 million patients at approximately 160 medical institutions. Persons with T2DM with an estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m2 in April 2014 were eligible. The primary end point was the composite of renal deterioration (>40% decline in eGFR) and the development of eGFR<30 mL/min/1.73 m2. We estimated the risk of the composite end point occurring over 77 months in different scenarios, such as early or delayed intervention with SGLT2 inhibitors for uncontrolled diabetes at different hemoglobin A1c (HbA1c) thresholds. The parametric g-formula was used to estimate the risk of the composite end point, adjusting for time-fixed and time-varying confounders. [Results] We analyzed data from 36 237 persons (149 346 person-years observation), of whom 4679 started SGLT2 inhibitor therapy (9470 person-years observation). Overall, initiating SGLT2 inhibitor therapy was associated with a 77-month risk reduction in the end point by 1.3–3.7%. The largest risk reduction was observed within 3 months of initiation once the HbA1c level exceeded 6.5% (risk reduction of 3.7% (95% CI 1.6% to 6.7%)) compared with a threshold of 7.0% or higher. [Conclusions] Our analyses favored early intervention with SGLT2 inhibitors to reduce the renal end point, even for persons with moderately controlled HbA1c levels. Our findings also suggest caution against clinical inertia in the care of diabetes

    Comparative Effectiveness of Sodium-Glucose Cotransporter-2 Inhibitors Versus Other Classes of Glucose-Lowering Medications on Renal Outcome in Type 2 Diabetes

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    Objective: To assess whether sodium-glucose cotransporter-2 inhibitor (SGLT2i) therapy is associated with a favorable renal prognosis for patients with type 2 diabetes melllitus (T2DM) outside the clinical trials setting. Participants and Methods: This retrospective study analyzed routinely collected health care records of ∼160 medical institutions in Japan from April 1, 2014, to December 31, 2017/2018 (varying at the institutional level). Adults with T2DM but without end-stage renal disease who initiated either SGLT2i or other classes of glucose-lowering medications (o-GLM) were matched using propensity score. The primary outcome was the time course of estimated glomerular filtration rate (eGFR) displayed in spline curve. The composite of renal worsening (>40% decline in eGFR) and the development of eGFR<30 mL/1.73 m2 per minute was evaluated as a secondary outcome. Two sensitivity analyses were conducted to determine the robustness of results. Results: We compared a matched cohort of 1433 SGLT2i users and 2739 o-GLM users (mean age: 61 years). The eGFR declined over time in both groups during the observation period (median: 17 months; maximum: 54 months), with a slower eGFR slope observed in SGLT2i users. This slower decline was consistently observed across different SGLT2i agents and different baseline eGFR groups. The cumulative incidence of composite renal endpoints was lower in the SGLT2i group with a hazard ratio of 0.70 (95% CI, 0.50-0.98; P=.039). Those findings were consistent in sensitivity analyses limited to the period adherent to the initial drug regimen and with a different approach for propensity score calculation. Conclusion: In a matched cohort of T2DM patients, SGLT2i use was associated with preserved renal function relative to o-GLM use over 2 to 4 years

    Lachmanテスト時に発生する膝関節音 : 健常膝と前十字靭帯損傷膝での比較検討

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    BACKGROUND: The Lachman test is clinically considered to be a reliable physical examination for anterior cruciate ligament (ACL) deficiency. However, the test involves subjective judgement of differences in tibial translation and endpoint quality. An auscultation system has been developed to allow assessment of the Lachman test. The knee joint sound during the Lachman test was analyzed using fast Fourier transformation. The purpose of the present study was to quantitatively evaluate knee joint sounds in healthy and ACL-deficient human knees. METHODS: Sixty healthy volunteers and 24 patients with ACL injury were examined. The Lachman test with joint auscultation was evaluated using a microphone. Knee joint sound during the Lachman test (Lachman sound) was analyzed by fast Fourier transformation. As quantitative indices of the Lachman sound, the peak sound (Lachman peak sound) as the maximum relative amplitude (acoustic pressure) and its frequency were used. RESULTS: In healthy volunteers, the mean Lachman peak sound of intact knees was 100.6 Hz in frequency and -45 dB in acoustic pressure. Moreover, a sex difference was found in the frequency of the Lachman peak sound. In patients with ACL injury, the frequency of the Lachman peak sound of the ACL-deficient knees was widely dispersed. In the ACL-deficient knees, the mean Lachman peak sound was 306.8 Hz in frequency and -63.1 dB in acoustic pressure. If the reference range was set at the frequency of the healthy volunteer Lachman peak sound, the sensitivity, specificity, positive predictive value, and negative predictive value were 83.3%, 95.6%, 95.2%, and 85.2%, respectively. CONCLUSION: Knee joint auscultation during the Lachman test was capable of judging ACL deficiency on the basis of objective data. In particular, the frequency of the Lachman peak sound was able to assess ACL condition.博士(医学)・甲第673号・平成29年6月28日Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved

    Draft Genome Sequence of Streptomyces incarnatus NRRL8089, which Produces the Nucleoside Antibiotic Sinefungin

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    A draft genome sequence of Streptomyces incarnatus NRRL8089, which produces the nucleoside antibiotic sinefungin, is described here. The genome contains 8,897,465 bp in 76 contigs and 8,266 predicted genes. Interestingly, the genome encodes an open reading frame for selenocysteine-containing formate dehydrogenase-O and the selenoprotein biosynthetic gene cluster selABCD

    ショウガオールはヒト歯肉線維芽細胞において酸化ストレス反応の調節を介してAGEs誘導性のIL-6およびICAM-1産生を抑制する

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    Advanced glycation end-products (AGEs) cause diabetes mellitus (DM) complications and accumulate more highly in periodontal tissues of patients with periodontitis and DM. AGEs aggravate periodontitis with DM by increasing the expression of inflammation-related factors in periodontal tissues. 6-Shogaol, a major compound in ginger, has anti-inflammatory and anti-oxidative activities. However, the influence of shogaol on DM-associated periodontitis is not well known. In this study, the effects of 6-shogaol on AGEs-induced oxidative and anti-oxidative responses, and IL-6 and ICAM-1 expression in human gingival fibroblasts (HGFs) were investigated. When HGFs were cultured with 6-shogaol and AGEs, the activities of reactive oxygen species (ROS) and antioxidant enzymes (heme oxygenase-1 [HO-1] and NAD(P)H quinone dehydrogenase 1 [NQO1]), and IL-6 and ICAM-1 expressions were investigated. RAGE expression and phosphorylation of MAPKs and NF-κB were examined by western blotting. 6-Shogaol significantly inhibited AGEs-induced ROS activity, and increased HO-1 and NQO1 levels compared with the AGEs-treated cells. The AGEs-stimulated expression levels of receptor of AGE (RAGE), IL-6 and ICAM-1 and the phosphorylation of p38, ERK and p65 were attenuated by 6-shogaol. These results suggested that 6-shogaol inhibits AGEs-induced inflammatory responses by regulating oxidative and anti-oxidative activities and may have protective effects on periodontitis with DM

    S100A9は、骨細胞様細胞においてMAPKsおよびSTAT3シグナル伝達経路を介してIL-6およびRANKLの発現を増加させる

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    Objective: Calprotectin is hetero-complex of S100A8 and S100A9 and mainly secreted from neutrophils, monocytes and chondrocytes in inflammatory condition. Calprotectin binds to RAGE and TLR4, and induces the expression of pro-inflammatory chemokines and cytokines in various cells. Periodontitis is chronic inflammatory disease to lead gingival inflammation and alveolar bone resorption. Calprotectin levels in gingival crevicular fluid of periodontitis patients are higher than healthy patients. In the present study, the effects of S100A8 and S100A9 on the expressions of pro-inflammatory cytokines and bone metabolism related factor in mouse osteocyte like cells (MLO-Y4-A2) were investigated. Design: MLO-Y4-A2 cells were treated with S100A8 and S100A9, and the expressions of RAGE, TLR4, RANKL and several inflammatory cytokines were analyzed by PCR and Western blotting or ELISA methods. To investigate the intracellular signaling pathways, phosphorylation of MAPK and STAT3 was determined by Western blotting, and chemical specific inhibitors and siRNAs were used. Results: Expressions of IL-6 and RANKL were increased by treatment with S100A9 but not S100A8. However, both S100A8 and S100A9 did not changed expression of IL-1β, IL-8 and TNF-α. Although RAGE and TLR4 expressions were not up-regulated by S100A9 treatment, transfection of siRNA for RAGE and TLR4 significantly decreased IL-6 and RANKL expressions. In addition, S100A9 activated p38, ERK and STAT3 signaling pathways, and inhibitors for these factors significantly decreased S100A9 induced IL-6 and RANKL expressions. Conclusions: These results indicated that S100A9 induces IL-6 and RANKL production via engagement with RAGE and TLR4 signalings in osteocytes and suggested that S100A9 may play important roles in the periodontal alveolar bone destruction
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