58 results on '"Tatsuya Akiyama"'
Search Results
2. A case of Marfan syndrome with massive haemoptysis from collaterals of the lateral thoracic artery
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Yuki Yabuuchi, Hitomi Goto, Mizu Nonaka, Hiroaki Tachi, Tatsuya Akiyama, Naoki Arai, Hiroaki Ishikawa, Kentaro Hyodo, Kenji Nemoto, Yukiko Miura, Isano Hase, Shingo Usui, Shuji Oh-ishi, Kenji Hayashihara, Takefumi Saito, and Tatsuya Chonan
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Giant pulmonary cysts ,Chronic intrathoracic inflammation ,Non-bronchial systemic arteries ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background Marfan Syndrome (MFS) is a heritable connective tissue disorder with a high degree of clinical variability including respiratory diseases; a rare case of MFS with massive intrathoracic bleeding has been reported recently. Case presentation A 32-year-old man who had been diagnosed with MFS underwent a Bentall operation with artificial valve replacement for aortic dissection and regurgitation of an aortic valve in 2012. Warfarin was started postoperatively, and the dosage was gradually increased until 2017, when the patient was transported to our hospital due to sudden massive haemoptysis. Computed tomography (CT) with a maximum intensity projection (MIP) revealed several giant pulmonary cysts with fluid levels in the apex of the right lung with an abnormal vessel from the right subclavian artery. Transcatheter arterial embolization was performed with angiography and haemostasis was achieved, which suggested that the bleeding vessel was the lateral thoracic artery (LTA) branch. CT taken before the incident indicated thickening of the cystic wall adjacent to the thorax; therefore, it was postulated that the bleeding originated from fragile anastomoses between the LTA and pulmonary or bronchial arteries. It appears that the vessels exhibited inflammation that began postoperatively, which extended to the cysts. Conclusion We experienced a case of MFS with massive haemoptysis from the right LTA. We have to be aware of the possibility that massive haemoptysis could be induced in MFS with inflamed pulmonary cysts.
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- 2020
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3. Borderline pulmonary hypertension is associated with exercise intolerance and increased risk for acute exacerbation in patients with interstitial lung disease
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Kenji Nemoto, Shuji Oh-ishi, Tatsuya Akiyama, Yuki Yabuuchi, Hitomi Goto, Mizu Nonaka, Yuika Sasatani, Hiroaki Tachi, Naoki Arai, Hiroaki Ishikawa, Kentaro Hyodo, Isano Hase, Yukiko Miura, Takio Takaku, Kenji Hayashihara, and Takefumi Saito
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Acute exacerbation ,Borderline pulmonary hypertension ,Interstitial lung disease ,Pulmonary hypertension ,6-min walk test ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background Pulmonary hypertension (PH) is traditionally defined as a resting mean pulmonary artery pressure (mPAP) of ≥25 mmHg, while mPAP in the range of 21 to 24 mmHg is recognized as “borderline PH.” Interstitial lung disease (ILD) is complicated by the development of PH, which is known to be linked with exercise intolerance and a poor prognosis. Even though it has recently been recommended that PH is redefined as a mPAP of > 20 mmHg, little is known about the clinical significance of borderline PH in ILD. We evaluated whether borderline PH has an impact on the exercise capacity, risk of acute exacerbation (AE), and mortality in patients with ILD. Methods A total of 80 patients with ILD who underwent right heart catheterization (RHC) between November 2013 and October 2016 were included. The patients were divided into 3 groups according to the mPAP values: mPAP ≤20 mmHg (No-PH group; n = 56), 20
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- 2019
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4. A case of airway aluminosis with likely secondary pleuroparenchymal fibroelastosis
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Yuki Yabuuchi, Hitomi Goto, Mizu Nonaka, Hiroaki Tachi, Tatsuya Akiyama, Naoki Arai, Hiroaki Ishikawa, Kentaro Hyodo, Kenji Nemoto, Yukiko Miura, Isano Hase, Shuji Oh-ishi, Kenji Hayashihara, Takefumi Saito, and Tatsuya Chonan
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Interstitial pneumonia ,Occupational lung disease ,Trans-bronchial lung biopsy ,Elemental analysis ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background Excessive inhalation of aluminium powder occasionally results in upper lobe predominant lung fibrosis, which is similar to idiopathic pleuroparenchymal fibroelastosis (IPPFE) and has been suggested to be secondary PPFE. Case presentation A 67-year-old man who had worked in an aluminum-processing factory for 50 years visited our hospital complaining of exertional dyspnea. Chest computed tomography (CT) showed bilateral dense sub-pleural consolidation in the upper and middle lung fields, which was consistent with IPPFE; however, the possibility of secondary PPFE associated with aluminosis was not ruled out. Considering the patient’s critical condition, trans-bronchial lung biopsy (TBLB) rather than surgical lung biopsy was performed, with elemental analysis of the biopsied specimen. Unfortunately, the specimen obtained by TBLB did not contain alveolar tissue; therefore, pathological diagnosis of PPFE was not possible. However, radiographic findings were highly suggestive of PPFE. On elemental analysis, excessive amounts of aluminum were detected in the bronchiolar walls, establishing a diagnosis of airway aluminosis with likely secondary PPFE resulting from aluminium exposure. Conclusions TBLB with elemental analysis might be useful in differentiating idiopathic PPFE from secondary causes in dust inhalation related disease, such as aluminosis. This case indicated that inhalation of aluminium might cause secondary PPFE, with attention needing to be paid to avoid further exposure.
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- 2019
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5. DropSOAC: Stabilizing Microfluidic Drops for Time-Lapse Quantification of Single-Cell Bacterial Physiology
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Shawna L. Pratt, Geoffrey K. Zath, Tatsuya Akiyama, Kerry S. Williamson, Michael J. Franklin, and Connie B. Chang
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drop-based microfluidics ,single cell ,growth rate ,lag time ,time-lapse imaging ,biofilm ,Microbiology ,QR1-502 - Abstract
The physiological heterogeneity of cells within a microbial population imparts resilience to stresses such as antimicrobial treatments and nutrient limitation. This resilience is partially due to a subpopulation of cells that can survive such stresses and regenerate the community. Microfluidic approaches now provide a means to study microbial physiology and bacterial heterogeneity at the single cell level, improving our ability to isolate and examine these subpopulations. Drop-based microfluidics provides a high-throughput approach to study individual cell physiology within bacterial populations. Using this approach, single cells are isolated from the population and encapsulated in growth medium dispersed in oil using a 15 μm diameter drop making microfluidic device. The drops are arranged as a packed monolayer inside a polydimethylsiloxane (PDMS) microfluidic device. Growth of thousands of individual cells in identical microenvironments can then be imaged using confocal laser scanning microscopy (CLSM). A challenge for this approach has been the maintenance of drop stability during extended time-lapse imaging. In particular, the drops do not maintain their volume over time during incubation in PDMS devices, due to fluid transport into the porous PDMS surroundings. Here, we present a strategy for PDMS device preparation that stabilizes drop position and volume within a drop array on a microfluidic chip for over 20 h. The stability of water-in-oil drops is maintained by soaking the device in a reservoir containing both water and oil in thermodynamic equilibrium. This ensures that phase equilibrium of the drop emulsion fluids within the porous PDMS material is maintained during drop incubation and imaging. We demonstrate the utility of this approach, which we label DropSOAC (DropStabilization On AChip), for time-lapse studies of bacterial growth. We characterize growth of Pseudomonas aeruginosa and its Δhpf mutant derivative during resuscitation and growth following starvation. We demonstrate that growth rate and lag time heterogeneity of hundreds of individual bacterial cells can be determined starting from single isolated cells. The results show that the DropSOAC capsule provides a high-throughput approach toward studies of microbial physiology at the single cell level, and can be used to characterize physiological differences of cells from within a larger population.
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- 2019
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6. Direct Reprogramming Improves Cardiac Function and Reverses Fibrosis in Chronic Myocardial Infarction
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Hidenori Tani, Taketaro Sadahiro, Yu Yamada, Mari Isomi, Hiroyuki Yamakawa, Ryo Fujita, Yuto Abe, Tatsuya Akiyama, Koji Nakano, Yuta Kuze, Masahide Seki, Yutaka Suzuki, Manabu Fujisawa, Mamiko Sakata-Yanagimoto, Shigeru Chiba, Keiichi Fukuda, and Masaki Ieda
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Physiology (medical) ,Cardiology and Cardiovascular Medicine - Abstract
Background: Because adult cardiomyocytes have little regenerative capacity, resident cardiac fibroblasts (CFs) synthesize extracellular matrix after myocardial infarction (MI) to form fibrosis, leading to cardiac dysfunction and heart failure. Therapies that can regenerate the myocardium and reverse fibrosis in chronic MI are lacking. The overexpression of cardiac transcription factors, including Mef2c/Gata4/Tbx5/Hand2 (MGTH), can directly reprogram CFs into induced cardiomyocytes (iCMs) and improve cardiac function under acute MI. However, the ability of in vivo cardiac reprogramming to repair chronic MI with established scars is undetermined. Methods: We generated a novel Tcf21 iCre /reporter/MGTH2A transgenic mouse system in which tamoxifen treatment could induce both MGTH and reporter expression in the resident CFs for cardiac reprogramming and fibroblast lineage tracing. We first tested the efficacy of this transgenic system in vitro and in vivo for acute MI. Next, we analyzed in vivo cardiac reprogramming and fusion events under chronic MI using Tcf21 iCre /Tomato/MGTH2A and Tcf21 iCre /mTmG/MGTH2A mice, respectively. Microarray and single-cell RNA sequencing were performed to determine the mechanism of cardiac repair by in vivo reprogramming. Results: We confirmed the efficacy of transgenic in vitro and in vivo cardiac reprogramming for acute MI. In chronic MI, in vivo cardiac reprogramming converted ≈2% of resident CFs into iCMs, in which a majority of iCMs were generated by means of bona fide cardiac reprogramming rather than by fusion with cardiomyocytes. Cardiac reprogramming significantly improved myocardial contraction and reduced fibrosis in chronic MI. Microarray analyses revealed that the overexpression of MGTH activated cardiac program and concomitantly suppressed fibroblast and inflammatory signatures in chronic MI. Single-cell RNA sequencing demonstrated that resident CFs consisted of 7 subclusters, in which the profibrotic CF population increased under chronic MI. Cardiac reprogramming suppressed fibroblastic gene expression in chronic MI by means of conversion of profibrotic CFs to a quiescent antifibrotic state. MGTH overexpression induced antifibrotic effects partly by suppression of Meox1, a central regulator of fibroblast activation. Conclusions: These results demonstrate that cardiac reprogramming could repair chronic MI by means of myocardial regeneration and reduction of fibrosis. These findings present opportunities for the development of new therapies for chronic MI and heart failure.
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- 2023
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7. One-step and room-temperature fabrication of carbon nanocomposites including Ni nanoparticles for supercapacitor electrodes
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Tatsuya Akiyama, Shuhei Nakanishi, Yazid Yaakob, Bhagyashri Todankar, Vikaskumar Pradeepkumar Gupta, Toru Asaka, Yosuke Ishii, Shinji Kawasaki, and Masaki Tanemura
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General Chemical Engineering ,General Chemistry - Abstract
With the increasing importance of power storage devices, demand for the development of supercapacitors possessing both rapid reversible chargeability and high energy density is accelerating. Here we propose a simple process for the room temperature fabrication of pseudocapacitor electrodes consisting of a faradaic redox reaction layer on a metallic electrode with an enhanced surface area. As a model metallic electrode, an Au foil was irradiated with Ar
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- 2022
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8. Stochastic response of bacterial cells to antibiotics: its mechanisms and implications for population and evolutionary dynamics
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Minsu Kim and Tatsuya Akiyama
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Microbiology (medical) ,Genetics ,education.field_of_study ,Bacteria ,biology ,Resistance (ecology) ,medicine.drug_class ,Population size ,Population ,Antibiotics ,Bacterial Infections ,biology.organism_classification ,Biological Evolution ,Microbiology ,Anti-Bacterial Agents ,Infectious Diseases ,Antibiotic resistance ,Drug Resistance, Bacterial ,Genotypic resistance ,medicine ,Humans ,Evolutionary dynamics ,education ,Cell Division - Abstract
The effectiveness of antibiotics against bacterial infections has been declining due to the emergence of resistance. Precisely understanding the response of bacteria to antibiotics is critical to maximizing antibiotic-induced bacterial eradication while minimizing the emergence of antibiotic resistance. Cell-to-cell heterogeneity in antibiotic susceptibility is observed across various bacterial species for a wide range of antibiotics. Heterogeneity in antibiotic susceptibility is not always due to the genetic differences. Rather, it can be caused by non-genetic mechanisms such as stochastic gene expression and biased partitioning upon cell division. Heterogeneous susceptibility leads to the stochastic growth and death of individual cells and stochastic fluctuations in population size. These fluctuations have important implications for the eradication of bacterial populations and the emergence of genotypic resistance.
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- 2021
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9. Flk1 Deficiency and Hypoxia Synergistically Promote Endothelial Dysfunction, Vascular Remodeling, and Pulmonary Hypertension.
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Tatsuya Akiyama, Taketaro Sadahiro, Yu Yamada, Ryo Fujita, Yuto Abe, Koji Nakano, Seiichiro Honda, Masatsugu Ema, Yoshiaki Kubota, Satoshi Sakai, Nobuyuki Hizawa, and Masaki Ieda
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- 2023
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10. Soft Matrix Promotes Cardiac Reprogramming via Inhibition of YAP/TAZ and Suppression of Fibroblast Signatures
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Fumiya Tamura, Shota Kurotsu, Yuto Abe, Masaki Ieda, Keiichi Fukuda, Takeshi Suzuki, Ichiro Harada, Hiroyuki Yamakawa, Taketaro Sadahiro, Ryo Fujita, Hidenori Kojima, Yu Yamada, Yoshiko Murakata, Naoto Muraoka, Tatsuya Akiyama, Hidenori Tani, and Mari Isomi
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0301 basic medicine ,rho GTP-Binding Proteins ,Integrins ,Integrin ,Genetic Vectors ,Mice, Transgenic ,Matrix (biology) ,Biology ,cardiac reprogramming ,Biochemistry ,Regenerative medicine ,Sendai virus ,Article ,03 medical and health sciences ,0302 clinical medicine ,Genetics ,medicine ,YAP/TAZ ,Animals ,Myocytes, Cardiac ,Mechanotransduction ,Fibroblast ,mechanotransduction ,Adaptor Proteins, Signal Transducing ,Myosin Type II ,Matrigel ,rho-Associated Kinases ,soft matrix ,Myocardium ,YAP-Signaling Proteins ,Cell Biology ,Actomyosin ,Fibroblasts ,biology.organism_classification ,Cellular Reprogramming ,Cell biology ,Extracellular Matrix ,030104 developmental biology ,medicine.anatomical_structure ,biology.protein ,cardiovascular system ,Reprogramming ,030217 neurology & neurosurgery ,Developmental Biology ,Signal Transduction - Abstract
Summary Direct cardiac reprogramming holds great potential for regenerative medicine. However, it remains inefficient, and induced cardiomyocytes (iCMs) generated in vitro are less mature than those in vivo, suggesting that undefined extrinsic factors may regulate cardiac reprogramming. Previous in vitro studies mainly used hard polystyrene dishes, yet the effect of substrate rigidity on cardiac reprogramming remains unclear. Thus, we developed a Matrigel-based hydrogel culture system to determine the roles of matrix stiffness and mechanotransduction in cardiac reprogramming. We found that soft matrix comparable with native myocardium promoted the efficiency and quality of cardiac reprogramming. Mechanistically, soft matrix enhanced cardiac reprogramming via inhibition of integrin, Rho/ROCK, actomyosin, and YAP/TAZ signaling and suppression of fibroblast programs, which were activated on rigid substrates. Soft substrate further enhanced cardiac reprogramming with Sendai virus vectors via YAP/TAZ suppression, increasing the reprogramming efficiency up to ∼15%. Thus, mechanotransduction could provide new targets for improving cardiac reprogramming., Graphical Abstract, Highlights • Hydrogel culture reveals the role of mechanotransduction in cardiac reprogramming • Soft ECM comparable with native myocardium promotes cardiac reprogramming • Soft ECM promotes cardiac reprogramming via YAP/TAZ/fibroblast signaling inhibition • Soft ECM promotes Sendai virus vector-mediated cardiac reprogramming, In this article, Ieda and colleagues showed that a soft matrix, which is comparable with native myocardium, efficiently promoted cardiac reprogramming. This soft matrix enhanced cardiac reprogramming via inhibition of integrin, Rho/ROCK, actomyosin, and YAP/TAZ signaling and subsequent suppression of fibroblast programs, which were activated on conventional rigid substrates, thus demonstrating that mechanotransduction plays a critical role in cardiac reprogramming.
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- 2020
11. Controllable fabrication of Au-nanoprotrusion arrays as a platform for the materials design and characterization
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Wei Ming Lin, Takumi Yoshida, Giri Suresh, Vikaskumar Pradeepkumar Gupta, Shinsuke Ozeki, Kento Oyama, Tatsuya Akiyama, Yazid Yaakob, Toru Asaka, Yang Yong, Hidetoshi Miyazaki, Noriyuki Sonoyama, and Masaki Tanemura
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General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2023
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12. Controllable Fabrication of Au-Nanoprotrusion Arrays as a Platform for the Materials Design and Characterization
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Wei Ming Lin, Takumi Yoshida, Giri Suresh, Vikaskumar Pradeepkumar Gupta, Shinsuke Ozeki, Kento Oyama, Tatsuya Akiyama, Yazid Bin Yakoob, Toru Asaka, Yong Yang, Noriyuki Sonoyama, and Masaki Tanemura
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- 2022
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13. The Pseudomonas aeruginosa RpoH (σ32) Regulon and Its Role in Essential Cellular Functions, Starvation Survival, and Antibiotic Tolerance
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Kerry S. Williamson, Mensur Dlakić, Tatsuya Akiyama, and Michael J. Franklin
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Inorganic Chemistry ,sigma factor ,antibiotic resistance ,heat shock response ,dormancy ,molecular chaperones ,proteases ,Organic Chemistry ,General Medicine ,Physical and Theoretical Chemistry ,Molecular Biology ,Spectroscopy ,Catalysis ,Computer Science Applications - Abstract
The bacterial heat-shock response is regulated by the alternative sigma factor, σ32 (RpoH), which responds to misfolded protein stress and directs the RNA polymerase to the promoters for genes required for protein refolding or degradation. In P. aeruginosa, RpoH is essential for viability under laboratory growth conditions. Here, we used a transcriptomics approach to identify the genes of the RpoH regulon, including RpoH-regulated genes that are essential for P. aeruginosa. We placed the rpoH gene under control of the arabinose-inducible PBAD promoter, then deleted the chromosomal rpoH allele. This allowed transcriptomic analysis of the RpoH (σ32) regulon following a short up-shift in the cellular concentration of RpoH by arabinose addition, in the absence of a sudden change in temperature. The P. aeruginosa ∆rpoH (PBAD-rpoH) strain grew in the absence of arabinose, indicating that some rpoH expression occurred without arabinose induction. When arabinose was added, the rpoH mRNA abundance of P. aeruginosa ∆rpoH (PBAD-rpoH) measured by RT-qPCR increased five-fold within 15 min of arabinose addition. Transcriptome results showed that P. aeruginosa genes required for protein repair or degradation are induced by increased RpoH levels, and that many genes essential for P. aeruginosa growth are induced by RpoH. Other stress response genes induced by RpoH are involved in damaged nucleic acid repair and in amino acid metabolism. Annotation of the hypothetical proteins under RpoH control included proteins that may play a role in antibiotic resistances and in non-ribosomal peptide synthesis. Phenotypic analysis of P. aeruginosa ∆rpoH (PBAD-rpoH) showed that it is impaired in its ability to survive during starvation compared to the wild-type strain. P. aeruginosa ∆rpoH (PBAD-rpoH) also had increased sensitivity to aminoglycoside antibiotics, but not to other classes of antibiotics, whether cultured planktonically or in biofilms. The enhanced aminoglycoside sensitivity of the mutant strain may be due to indirect effects, such as the build-up of toxic misfolded proteins, or to the direct effect of genes, such as aminoglycoside acetyl transferases, that are regulated by RpoH. Overall, the results demonstrate that RpoH regulates genes that are essential for viability of P. aeruginosa, that it protects P. aeruginosa from damage from aminoglycoside antibiotics, and that it is required for survival during nutrient-limiting conditions.
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- 2023
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14. Long-term Progression-free Survival With Pemetrexed Plus Bevacizumab in NSCLC Patients.
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SHIGEN HAYASHI, KUNIHIKO MIYAZAKI, TOSHIHIRO SHIOZAWA, SHINICHIRO OKAUCHI, HIROFUMI SAKURAI, TATSUYA AKIYAMA, AKIHIRO NOMURA, HIROAKI SATOH, and NOBUYUKI HIZAWA
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PROGRESSION-free survival ,PEMETREXED ,NON-small-cell lung carcinoma ,BEVACIZUMAB - Abstract
Background/Aim: Pemetrexed (PEM) and bevacizumab (BEV) are commonly used in combination as second or subsequent line regimens and maintenance therapy after platinum + PEM + BEV therapy for advanced non-small cell lung cancer (NSCLC). Median progression-free survival (PFS) for PEM + BEV has been reported to be less than six months in both clinical trials and clinical practice, but in clinical practice, we found that some patients demonstrate long-term PFS. Furthermore, there is a paucity of clinical practice data on whether long-term administration of PEM + BEV causes renal dysfunction. This study aimed to clarify these aspects in clinical practice. Patients and Methods: A retrospective review of patients with advanced NSCLC treated with PEM + BEV between September 2011 and June 2022 at four hospitals was conducted. Long-term PFS in PEM + BEV therapy was defined as =12 months. Results: During the study period, 109 patients received PEM + BEV treatment. Of them, 42 (38.5%) achieved long-term PFS =12 months. No significant differences in patient characteristics were found between patients with PFS =12 months and <12 months, except for 'relapse after resection'. Univariate and multivariate analysis showed that the favorable factor for PFS was 'relapse after resection'. With regard to influence on renal function of PEM + BEV therapy, no significant difference was found before and after PEM+BEV therapy between these two groups. Conclusion: NSCLC patients commonly achieved long-term PFS with PEM + BEV therapy with no observed effects on renal function. [ABSTRACT FROM AUTHOR]
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- 2023
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15. Overexpression of Gata4, Mef2c, and Tbx5 Generates Induced Cardiomyocytes Via Direct Reprogramming and Rare Fusion in the Heart
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Hiroaki Mizukami, Tatsuya Akiyama, Tsugumine Shu, Keiichi Fukuda, Yoshiko Murakata, Masaki Ieda, Taketaro Sadahiro, Ryo Fujita, Yu Yamada, Yuto Abe, Hiroyuki Yamakawa, and Mari Isomi
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Male ,Fusion ,GATA4 ,business.industry ,MEF2 Transcription Factors ,Regeneration (biology) ,Myocardial Infarction ,Cellular Reprogramming ,Cell biology ,GATA4 Transcription Factor ,Cell Fusion ,Mice ,Physiology (medical) ,Medicine ,Animals ,MEF2C ,Female ,Myocytes, Cardiac ,Cardiology and Cardiovascular Medicine ,business ,T-Box Domain Proteins ,Reprogramming - Published
- 2021
16. A NUMERICAL SIMULATION OF DISASTER WASTE DISPOSAL IN WAKAYAMA CITY BY USING DHT MODEL
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Nobuyuki Egusa, Hiroto Tanouchi, Tatsuya Akiyama, and Soichiro Asai
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Temporary storage ,Environmental Engineering ,Nankai trough ,Waste management ,Computer simulation ,Disaster waste ,Soil Science ,Environmental science ,Christian ministry ,Building and Construction ,Geotechnical Engineering and Engineering Geology - Abstract
We conducted a numerical simulation of disaster waste disposal by using a Dynamic Hauling/Transportation model (DHT model) in order to extract the factors to hinder the execution of a disposal management plan of Wakayama city government. The DHT model was developed for estimating number of days required for disaster waste disposal, following parameters are mandisopdatory as the model inputs; (1) disaster waste characteristics (distributions, volume and contents) in damaged area, (2) hauling/transportation route, (3) number/capacities of transportation vehicles, (4) maximum capacities at temporary storage / final disposal sites and (5) abilities of crushing/classification equipment. Almost all parameters were set by referring to a planning document of disaster waste disposal provided by Wakayama city and disposal guidelines published by Ministry of the Environment of Japan. Several parameters without description in these document/guideline, e.g. maximum capacities at temporary storage and distance of hauling/transportation route were estimated by using GIS. Severe shock and tsunami caused by Nankai Trough huge earthquake were adopted as external forces generating disaster waste. By assumption that parameters included in (3) and (5) could be critical parameters for a result of simulation, we performed sensitivity analysis of each parameter in them. As a result, abilities of several crushing / classification at temporary storages were the most sensitive parameters of all evaluated parameters. Therefore, augments of crushing/classification functions at temporary storage might be effective to shorten processing days for disaster waste disposal
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- 2021
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17. Direct reprogramming with Sendai virus vectors repaired infarct hearts at the chronic stage
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Taketaro Sadahiro, Ryo Fujita, Hiroaki Mizukami, Mari Isomi, Masaki Ieda, Keiichi Fukuda, Tatsuya Akiyama, Tsugumine Shu, Yu Yamada, and Yuto Abe
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0301 basic medicine ,Cardiac function curve ,Male ,Genetic Vectors ,Biophysics ,Myocardial Infarction ,Biochemistry ,Sendai virus ,Collagen Type I ,03 medical and health sciences ,0302 clinical medicine ,Fibrosis ,medicine ,Animals ,MEF2C ,Myocytes, Cardiac ,Myocardial infarction ,Ventricular remodeling ,Molecular Biology ,biology ,business.industry ,Myocardium ,Cell Biology ,Fibroblasts ,medicine.disease ,biology.organism_classification ,Cellular Reprogramming ,Mice, Inbred C57BL ,030104 developmental biology ,030220 oncology & carcinogenesis ,Heart failure ,Chronic Disease ,cardiovascular system ,Cancer research ,business ,Reprogramming ,Transcription Factors - Abstract
Adult hearts have limited regenerative capacity. Hence, after acute myocardial infarction (MI), dead myocardial tissues are digested by immune cells and replaced by fibrosis, leading to ventricular remodeling and heart failure at the chronic stage. Direct reprogramming of the cardiac fibroblasts (CFs) into induced cardiomyocytes (iCMs) with cardiac transcription factors, including Gata4, Mef2c, and Tbx5 (GMT), may have significant potential for cardiac repair. Sendai virus (SeV) vectors expressing GMT have been reported to reprogram the mouse cardiac fibroblasts into iCMs without any risk of insertional mutagenesis. In vivo reprogramming improved the cardiac function after acute MI in immunodeficient mice. However, it is unknown whether the newly generated iCMs could exist in infarct hearts for a prolonged period and SeV-GMT can improve cardiac function after MI at the chronic stage in immunocompetent mice. Here, we show that SeV vectors efficiently infect CFs in vivo and reprogram them into iCMs, which existed for at least four weeks after MI, in fibroblast-linage tracing mice. Moreover, SeV-GMT improved cardiac function and reduced fibrosis and collagen I expression at 12 weeks after MI in immunocompetent mice. Thus, direct cardiac reprogramming with SeV vectors could be a promising therapy for MI.
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- 2021
18. Ein Fall von Aluminose der Atemwege mit wahrscheinlich sekundärer pleuroparenchymaler Fibroelastose
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Kenji Hayashihara, Yukiko Miura, Tatsuya Chonan, Mizu Nonaka, Takefumi Saito, Tatsuya Akiyama, Isano Hase, Hiroaki Tachi, Kentaro Hyodo, Hitomi Goto, Shuji Oh-ishi, Hiroaki Ishikawa, Yuki Yabuuchi, Kenji Nemoto, and Naoki Arai
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business.industry ,Medicine ,business - Abstract
Hintergrund: Die exzessive Inhalation von Aluminiumstaub führt gelegentlich zu einer überwiegend die Oberlappen betreffenden Lungenfibrose, die einer idiopathischen pleuroparenchymalen Fibroelastose (IPPFE) ähnelt und bei der es sich den Annahmen zufolge um eine sekundäre PPFE handelt. Fallbericht: Ein 67-jähriger Mann, der 50 Jahre lang in einem aluminiumverarbeitenden Unternehmen gearbeitet hatte, stellte sich mit Belastungsdyspnoe in unserer Klinik vor. Die Computertomographie (CT) des Thorax zeigte eine bilaterale dichte subpleurale Konsolidierung in den oberen und mittleren Lungenfeldern entsprechend einer IPPFE; eine etwaige sekundäre PPFE im Zusammenhang mit einer Aluminose wurde jedoch nicht ausgeschlossen. Aufgrund des kritischen Zustands des Patienten erfolgten eine transbronchiale Lungenbiopsie (TBLB) anstatt einer chirurgischen Lungenbiopsie sowie eine Elementaranalyse der entnommenen Gewebeprobe. Da die mittels TBLB gewonnene Probe bedauerlicherweise kein Alveolargewebe enthielt, konnte die Diagnose PPFE nicht pathologisch gesichert werden. Die radiologischen Befunde sprachen jedoch stark für eine PPFE. In der Elementaranalyse wurden hohe Mengen an Aluminium in den Bronchiolarwänden nachgewiesen, so dass die Diagnose einer Aluminose der Atemwege mit wahrscheinlich sekundärer PPFE infolge Aluminiumexposition gestellt wurde. Schlussfolgerungen: Eine TBLB mit Elementaranalyse kann zur Abgrenzung der idiopathischen PPFE von sekundären Ursachen bei staubbedingten Erkrankungen wie Aluminose hilfreich sein. Der vorliegende Fall zeigt, dass die Inhalation von Aluminium eine sekundäre PPFE verursachen kann; ein besonderes Augenmerk sollte auf die Vermeidung einer weiteren Exposition gelegt werden.
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- 2019
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19. Resuscitation of Pseudomonas aeruginosa from dormancy requires hibernation promoting factor (PA4463) for ribosome preservation
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Connie B. Chang, Robert Schaefer, Michael J. Franklin, Shawna L. Pratt, Kerry S. Williamson, and Tatsuya Akiyama
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Ribosomal Proteins ,0301 basic medicine ,Stringent response ,030106 microbiology ,medicine.disease_cause ,Ribosome ,Microbiology ,03 medical and health sciences ,Hibernation ,Protein biosynthesis ,medicine ,Multidisciplinary ,biology ,Pseudomonas aeruginosa ,fungi ,Biofilm ,Gene Expression Regulation, Bacterial ,Biological Sciences ,Ribosomal RNA ,biology.organism_classification ,030104 developmental biology ,RNA, Ribosomal ,Dormancy ,Energy Metabolism ,Ribosomes ,Bacteria - Abstract
Pseudomonas aeruginosa biofilm infections are difficult to treat with antibiotic therapy in part because the biofilms contain subpopulations of dormant antibiotic-tolerant cells. The dormant cells can repopulate the biofilms following alleviation of antibiotic treatments. While dormant, the bacteria must maintain cellular integrity, including ribosome abundance, to reinitiate the de novo protein synthesis required for resuscitation. Here, we demonstrate that the P. aeruginosa gene PA4463 [hibernation promoting factor (HPF)], but not the ribosome modulation factor (PA3049), is required for ribosomal RNA preservation during prolonged nutrient starvation conditions. Single-cell–level studies using fluorescence in situ hybridization (FISH) and growth in microfluidic drops demonstrate that, in the absence of hpf, the rRNA abundances of starved cells decrease to levels that cause them to lose their ability to resuscitate from starvation, leaving intact nondividing cells. P. aeruginosa defective in the stringent response also had reduced ability to resuscitate from dormancy. However, FISH analysis of the starved stringent response mutant showed a bimodal response where the individual cells contained either abundant or low ribosome content, compared with the wild-type strain. The results indicate that ribosome maintenance is key for maintaining the ability of P. aeruginosa to resuscitate from starvation-induced dormancy and that HPF is the major factor associated with P. aeruginosa ribosome preservation.
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- 2017
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20. A case of Marfan syndrome with massive haemoptysis from collaterals of the lateral thoracic artery
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Yukiko Miura, Isano Hase, Tatsuya Akiyama, Hiroaki Ishikawa, Shingo Usui, Hiroaki Tachi, Naoki Arai, Hitomi Goto, Kenji Hayashihara, Mizu Nonaka, Tatsuya Chonan, Kenji Nemoto, Shuji Oh-ishi, Kentaro Hyodo, Yuki Yabuuchi, and Takefumi Saito
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Pulmonary and Respiratory Medicine ,Marfan syndrome ,Aortic valve ,Thorax ,Adult ,Male ,medicine.medical_specialty ,Hemoptysis ,Chronic intrathoracic inflammation ,Case Report ,Marfan Syndrome ,03 medical and health sciences ,0302 clinical medicine ,Thoracic Arteries ,medicine.artery ,medicine ,Humans ,030212 general & internal medicine ,Lung ,lcsh:RC705-779 ,Aortic dissection ,medicine.diagnostic_test ,Lateral thoracic artery ,business.industry ,Angiography ,lcsh:Diseases of the respiratory system ,Giant pulmonary cysts ,medicine.disease ,Embolization, Therapeutic ,medicine.anatomical_structure ,Treatment Outcome ,030228 respiratory system ,Non-bronchial systemic arteries ,Radiology ,Bronchial artery ,business ,Tomography, X-Ray Computed - Abstract
Background Marfan Syndrome (MFS) is a heritable connective tissue disorder with a high degree of clinical variability including respiratory diseases; a rare case of MFS with massive intrathoracic bleeding has been reported recently. Case presentation A 32-year-old man who had been diagnosed with MFS underwent a Bentall operation with artificial valve replacement for aortic dissection and regurgitation of an aortic valve in 2012. Warfarin was started postoperatively, and the dosage was gradually increased until 2017, when the patient was transported to our hospital due to sudden massive haemoptysis. Computed tomography (CT) with a maximum intensity projection (MIP) revealed several giant pulmonary cysts with fluid levels in the apex of the right lung with an abnormal vessel from the right subclavian artery. Transcatheter arterial embolization was performed with angiography and haemostasis was achieved, which suggested that the bleeding vessel was the lateral thoracic artery (LTA) branch. CT taken before the incident indicated thickening of the cystic wall adjacent to the thorax; therefore, it was postulated that the bleeding originated from fragile anastomoses between the LTA and pulmonary or bronchial arteries. It appears that the vessels exhibited inflammation that began postoperatively, which extended to the cysts. Conclusion We experienced a case of MFS with massive haemoptysis from the right LTA. We have to be aware of the possibility that massive haemoptysis could be induced in MFS with inflamed pulmonary cysts.
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- 2019
21. Association between 4-metre gait speed and isometric knee extension muscle strength in patients with interstitial lung disease
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Hiroaki Tachi, Kenji Nemoto, Kentaro Hyodo, Takefumi Saito, Hiroaki Ishikawa, Yukiko Miura, Tatsuya Akiyama, Kenji Hayashihara, Mizu Nonaka, Isano Hase, Hitomi Goto, Naoki Arai, Shimao Fukai, Shuji Oh-ishi, Yuika Sasatani, and Yuki Yabuuchi
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medicine.medical_specialty ,Physical medicine and rehabilitation ,business.industry ,medicine ,Muscle strength ,Interstitial lung disease ,Metre ,In patient ,Isometric exercise ,Knee extension ,business ,medicine.disease ,Gait speed - Published
- 2018
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22. Borderline pulmonary hypertension is associated with exercise intolerance and increased risk for acute exacerbation in patients with interstitial lung disease
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Tatsuya Akiyama, Takeshi Yamamoto, Takefumi Saito, Yuya Koshiishi, Tetsuro Shiraishi, Shuji Oh-ishi, Akira Ito, Shinji Inamura, Kenji Nemoto, Shimao Fukai, Joichi Yamazaki, and Mitsunobu Ito
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medicine.medical_specialty ,Exacerbation ,business.industry ,Incidence (epidemiology) ,Interstitial lung disease ,Hemodynamics ,Exercise intolerance ,medicine.disease ,Pulmonary hypertension ,Pulmonary function testing ,medicine.artery ,Internal medicine ,Pulmonary artery ,Cardiology ,Medicine ,medicine.symptom ,business - Abstract
Background: Pulmonary hypertension (PH) is defined by a resting mean pulmonary artery pressure (mPAP) ≥ 25 mmHg, on the other hand, the term of mPAP ranging from 21 to 24 mmHg is recognized as “borderline PH”. However, little is known about the clinical importance of borderline PH in interstitial lung disease (ILD). Aims: To evaluate whether borderline PH has an impact on the exercise capacity and the risk of acute exacerbation (AE) in patients with ILD. Methods: Between November 2013 and October 2016, 80 patients with ILD (23 IPF) that underwent right heart catheterization were included. The patients were divided into 3 groups: mPAP ≤ 20mmHg (No-PH group; n = 56), 21 ≤ mPAP ≤ 24mmHg (Bo-PH group; n = 18) and mPAP ≥ 25mmHg (PH group; n = 6). Patients’ characteristics, hemodynamics, 6MWT data, and 1-year incidence of AE were collected. Results: There were no significant differences among 3 groups in patients’ characteristics including pulmonary function. However, both Bo-PH and PH groups had significantly lower 6-min walk distance (p Conclusions: The current study shows that borderline PH is associated with exercise intolerance and increased risk for acute exacerbation in patients with ILD. These results suggest that the presence of borderline PH should be considered the pulmonary vascular disorder in patients with ILD.
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- 2018
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23. Expression and regulation of the Pseudomonas aeruginosa hibernation promoting factor
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Michael J. Franklin, Kerry S. Williamson, and Tatsuya Akiyama
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0301 basic medicine ,DNA, Bacterial ,Ribosomal Proteins ,endocrine system ,animal structures ,Operon ,030106 microbiology ,Mutant ,Microbiology ,Article ,03 medical and health sciences ,Gene Knockout Techniques ,Bacterial Proteins ,RNA, Messenger ,Promoter Regions, Genetic ,Molecular Biology ,Gene ,Fluorescent Dyes ,Reporter gene ,Messenger RNA ,biology ,fungi ,Biofilm ,Gene Expression Regulation, Bacterial ,biology.organism_classification ,digestive system diseases ,Cell biology ,Biofilms ,embryonic structures ,Mutation ,Pseudomonas aeruginosa ,rpoN ,Ribosomes ,Bacteria - Abstract
Bacterial biofilms contain subpopulations of cells that are dormant and highly tolerant to antibiotics. While dormant, the bacteria must maintain the integrity of macromolecules required for resuscitation. Previously, we showed that hibernation promoting factor (HPF) is essential for protecting Pseudomonas aeruginosa from ribosomal loss during dormancy. In this study, we mapped the genetic components required for hpf expression. Using 5ʹ-RACE and fluorescent protein reporter fusions, we show that hpf is expressed as part of the rpoN operon, but that hpf also has a second promoter (P(hpf)) within the rpoN gene. P(hpf) is active when the cells enter stationary phase, and expression from P(hpf) is modulated, but not eliminated, in mutant strains impaired in stationary phase transition (ΔdksA2, ΔrpoS and ΔrelA/ΔspoT mutants). The results of reporter gene studies and mRNA folding predictions indicated that the 5ʹ end of the hpf mRNA may also influence hpf expression. Mutations that opened or that stabilized the mRNA hairpin loop structures strongly influenced the amount of HPF produced. The results demonstrate that hpf is expressed independently of rpoN, and that hpf regulation includes both transcriptional and post-transcriptional processes, allowing the cells to produce sufficient HPF during stationary phase to maintain viability while dormant.
- Published
- 2018
24. A NUMERICAL SIMULATION OF DISASTER WASTE DISPOSAL IN WAKAYAMA CITY BY USING DHT MODEL.
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Soichiro ASAI, Tatsuya AKIYAMA, Hiroto TANOUCHI, and Nobuyuki EGUSA
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WASTE management ,EMERGENCY management ,COMPUTER simulation ,DISASTERS ,MUNICIPAL government ,SENSITIVITY analysis - Abstract
We conducted a numerical simulation of disaster waste disposal by using a Dynamic Hauling/Transportation model (DHT model) in order to extract the factors to hinder the execution of a disposal management plan of Wakayama city government. The DHT model was developed for estimating number of days required for disaster waste disposal, following parameters are mandisopdatory as the model inputs; (1) disaster waste characteristics (distributions, volume and contents) in damaged area, (2) hauling/transportation route, (3) number/capacities of transportation vehicles, (4) maximum capacities at temporary storage / final disposal sites and (5) abilities of crushing/classification equipment. Almost all parameters were set by referring to a planning document of disaster waste disposal provided by Wakayama city and disposal guidelines published by Ministry of the Environment of Japan. Several parameters without description in these document/guideline, e.g. maximum capacities at temporary storage and distance of hauling/transportation route were estimated by using GIS. Severe shock and tsunami caused by Nankai Trough huge earthquake were adopted as external forces generating disaster waste. By assumption that parameters included in (3) and (5) could be critical parameters for a result of simulation, we performed sensitivity analysis of each parameter in them. As a result, abilities of several crushing / classification at temporary storages were the most sensitive parameters of all evaluated parameters. Therefore, augments of crushing/classification functions at temporary storage might be effective to shorten processing days for disaster waste disposal. [ABSTRACT FROM AUTHOR]
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- 2021
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25. Cytotoxic Mechanism ofCytolethal Distending Toxinin NontyphoidalSalmonellaSerovar (SalmonellaJaviana) During Macrophage Infection
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Kuppan Gokulan, Katherine Williams, Sangeeta Khare, Ashraf A. Khan, Diamond Shelman, and Tatsuya Akiyama
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Salmonella ,Cytolethal distending toxin ,Cell Survival ,Bacterial Toxins ,Gene Expression ,Apoptosis ,Biology ,medicine.disease_cause ,Virulence factor ,Cell Line ,Microbiology ,Mice ,Necrosis ,Phosphatidylinositol 3-Kinases ,Autophagy ,Genetics ,medicine ,Animals ,Cytotoxic T cell ,Cell Shape ,Molecular Biology ,bcl-2-Associated X Protein ,Reverse Transcriptase Polymerase Chain Reaction ,Toxin ,Macrophages ,Estrogen Receptor alpha ,Wild type ,Cell Biology ,General Medicine ,Deubiquitinating Enzyme CYLD ,Cysteine Endopeptidases ,Microscopy, Fluorescence ,Host-Pathogen Interactions ,Mutation ,Microtubule-Associated Proteins - Abstract
Cytolethal distending toxin B (cdtB) is a conserved virulence factor in Salmonella enterica serovar Typhi. Here we report the presence and functionality of cdtB in some nontyphoidal Salmonella (NTS) serovars, including Salmonella Javiana (cdtB+wt S. Javiana), isolated from imported food. To understand the role of cdtB in NTS serovars, a deletion mutant (cdtB(-)ΔS. Javiana) was constructed. Macrophages were infected with cdtB+wt S. Javiana (wild type), cdtB(-)Δ S. Javiana (mutant), and cdtB-negative NTS serovar (S. Typhimurium). Cytotoxic activity and transcription level of genes involved in cell death (apoptosis, autophagy, and necrosis) were assessed in infected macrophages. The cdtB+wt S. Javiana caused cellular distension as well as high degree of vacuolization and presence of the autophagosome marker LC3 in infected macrophages as compared with cdtB(-)ΔS. Javiana. The mRNA expression of genes involved in the induction of autophagy in response to toxin (Esr1 and Pik3C3) and coregulators of autophagy and apoptosis (Bax and Cyld) were significantly upregulated in cdtB(+)wt S. Javiana-infected macrophages. As autophagy destroys internalized pathogens in addition to the infected cell, it may reduce the spread of infection.
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- 2015
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26. TIME TO DETECTION OF MYCOBACTERIUM AVIUM COMPLEX USING LIQUID MEDIA CORRELATES WITH MYCOBACTERIUM AVIUM COMPLEX LUNG DISEASE ACTIVITY
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Yukiko Miura, Shuji Oh-ishi, Mizu Nonaka, Hiroaki Ishikawa, Kenji Nemoto, Takefumi Saito, Yuki Yabuuchi, Kentaro Hyodo, Tatsuya Akiyama, Hiroaki Tachi, Kenji Hayashihara, Naoki Arai, Isano Hase, Yuika Sasatani, and Hitomi Goto
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Pulmonary and Respiratory Medicine ,Time to detection ,biology ,Lung disease ,business.industry ,Medicine ,Mycobacterium avium complex ,Cardiology and Cardiovascular Medicine ,Critical Care and Intensive Care Medicine ,biology.organism_classification ,business ,Microbiology - Published
- 2018
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27. Isolation and characterization of smallqnrS1-carrying plasmids from imported seafood isolates ofSalmonella entericathat are highly similar to plasmids of clinical isolates
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Ashraf A. Khan and Tatsuya Akiyama
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DNA Topoisomerase IV ,Salmonella typhimurium ,Microbiology (medical) ,Serotype ,Salmonella ,Nalidixic acid ,medicine.drug_class ,Immunology ,Taiwan ,Microbial Sensitivity Tests ,Quinolones ,medicine.disease_cause ,Microbiology ,Nalidixic Acid ,Plasmid ,Drug Resistance, Multiple, Bacterial ,medicine ,Immunology and Allergy ,Norfloxacin ,biology ,Salmonella enterica ,General Medicine ,Thailand ,Quinolone ,biology.organism_classification ,Virology ,United Kingdom ,Anti-Bacterial Agents ,Ciprofloxacin ,Infectious Diseases ,Seafood ,Vietnam ,DNA Gyrase ,Salmonella Infections ,Public Health ,Plasmids ,medicine.drug - Abstract
Dissemination of plasmid-mediated quinolone resistance among pathogenic bacteria is a concern for public health because of decreased sensitivity to fluoroquinolones and increased potentials to develop high fluoroquinolone resistance. Two qnrS1 -positive isolates of Salmonella enterica Corvallis (468) and Typhimurium (484) from imported seafood (Thailand and Vietnam) were tested for quinolone sensitivity using disk agar diffusion and the Sensititre® system. The presence of qnr genes, qnr carrying plasmids, and mutations in the quinolone resistance determining regions were also determined. Minimal inhibitory concentrations of nalidixic acid for isolates 468 and 484 were 8 and 16 µg mL−1, respectively, and those of ciprofloxacin were 1 and 2 µg mL−1, respectively. Disk agar diffusion indicated that isolate 468 was moderately resistant to moxifloxacin, and isolate 484 was resistant to moxifloxacin and moderately resistant to norfloxacin. Isolates 468 and 484 carried a mutation on parC , but not on gyrA , gyrB , or parE . Sequences of qnrS1 -carrying plasmids from isolates 468 and 484, sized 10 039 and 10 047 bp, were nearly identical (> 99% similarity) to each other and to published sequences of plasmids from clinical isolates of Salmonella Typhimurium isolated in the United Kingdom and Taiwan, indicating a dissemination of qnrS1 -carrying plasmids among different serovars of Salmonella from geographically separated sources. This is the first complete sequence of a qnrS1 -carrying plasmid from imported seafood isolate of S. enterica .
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- 2012
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28. A case of development of heparin-induced thrombocytopenia at the time of initiation of hemodialysis, with subsequent successful re-administration to heparin
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Takeshi Inoue, Takashi Kawakami, Tatsuya Akiyama, and Motoyoshi Yoshikawa
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medicine.medical_specialty ,business.industry ,Heparin-induced thrombocytopenia ,medicine.medical_treatment ,medicine ,Urology ,Hemodialysis ,Heparin ,medicine.disease ,business ,medicine.drug - Abstract
血液透析導入時にヘパリン起因性血小板減少症(HIT)を発症し,その後ヘパリンの再投与に成功した症例を経験したので報告する.症例は68歳女性.以前より慢性腎不全を指摘されており,近医に通院していた.末期腎不全にて当院紹介受診し,血液透析導入目的で入院した.入院後,内シャント造設術を施行した.シャント血流は良好であった.透析の抗凝固剤として未分画ヘパリンを使用した.第1回透析から第3回透析までは著変なく施行できた.第4回,第5回透析では若干の静脈圧の上昇を認めたが,明らかな回路内凝固は認めなかった.第6回透析では静脈圧の上昇とチャンバー・ダイアライザーの凝血を認めた.ヘパリン量の不足が原因と考え,ヘパリンの増量を行ったが改善を認めなかった.透析前後で血小板数の減少があり,HITを疑い,抗血小板第4因子/ヘパリン複合体抗体(HIT抗体)を測定した.抗凝固剤をメシル酸ナファモスタットに変更後,回路内凝固と血小板減少は改善した.HIT抗体が陽性であったため,HITと診断し,抗凝固剤をアルガトロバンに変更し,開始時10mg,持続25mg/時で血液透析を行った.以降は回路内凝固を認めず,また,血小板減少も認めなかった.その間,血栓症の合併はなかった.経時的にHIT抗体価を測定し,HIT抗体価が陰性化したことを確認した.ヘパリンの再投与を試みたところ,回路内凝固や血小板減少を認めることなく,血液透析を施行することができた.HIT抗体価の再上昇もなく,現在に至っている.
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- 2009
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29. The Pseudomonas aeruginosa PAO1 Two-Component Regulator CarSR Regulates Calcium Homeostasis and Calcium-Induced Virulence Factor Production through Its Regulatory Targets CarO and CarP
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Manita Guragain, Michelle King, Michael J. Franklin, Sharmily Khanam, Marianna A. Patrauchan, Kerry S. Williamson, Ailyn C. Pérez-Osorio, and Tatsuya Akiyama
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0301 basic medicine ,Operon ,Virulence Factors ,030106 microbiology ,Virulence ,Swarming motility ,Biology ,medicine.disease_cause ,Microbiology ,Virulence factor ,03 medical and health sciences ,chemistry.chemical_compound ,Pyocyanin ,Bacterial Proteins ,medicine ,Homeostasis ,Gene Regulatory Networks ,Molecular Biology ,Regulation of gene expression ,Pseudomonas aeruginosa ,Gene Expression Profiling ,Articles ,Gene Expression Regulation, Bacterial ,chemistry ,Biofilms ,Calcium ,Gene Deletion - Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen that causes severe, life-threatening infections in patients with cystic fibrosis (CF), endocarditis, wounds, or artificial implants. During CF pulmonary infections, P. aeruginosa often encounters environments where the levels of calcium (Ca 2+ ) are elevated. Previously, we showed that P. aeruginosa responds to externally added Ca 2+ through enhanced biofilm formation, increased production of several secreted virulence factors, and by developing a transient increase in the intracellular Ca 2+ level, followed by its removal to the basal submicromolar level. However, the molecular mechanisms responsible for regulating Ca 2+ -induced virulence factor production and Ca 2+ homeostasis are not known. Here, we characterized the genome-wide transcriptional response of P. aeruginosa to elevated [Ca 2+ ] in both planktonic cultures and biofilms. Among the genes induced by CaCl 2 in strain PAO1 was an operon containing the two-component regulator PA2656-PA2657 (here called carS and carR ), while the closely related two-component regulators phoPQ and pmrAB were repressed by CaCl 2 addition. To identify the regulatory targets of CarSR, we constructed a deletion mutant of carR and performed transcriptome analysis of the mutant strain at low and high [Ca 2+ ]. Among the genes regulated by CarSR in response to CaCl 2 are the predicted periplasmic OB-fold protein, PA0320 (here called carO ), and the inner membrane-anchored five-bladed β-propeller protein, PA0327 (here called carP ). Mutations in both carO and carP affected Ca 2+ homeostasis, reducing the ability of P. aeruginosa to export excess Ca 2+ . In addition, a mutation in carP had a pleotropic effect in a Ca 2+ -dependent manner, altering swarming motility, pyocyanin production, and tobramycin sensitivity. Overall, the results indicate that the two-component system CarSR is responsible for sensing high levels of external Ca 2+ and responding through its regulatory targets that modulate Ca 2+ homeostasis, surface-associated motility, and the production of the virulence factor pyocyanin. IMPORTANCE During infectious disease, Pseudomonas aeruginosa encounters environments with high calcium (Ca 2+ ) concentrations, yet the cells maintain intracellular Ca 2+ at levels that are orders of magnitude less than that of the external environment. In addition, Ca 2+ signals P. aeruginosa to induce the production of several virulence factors. Compared to eukaryotes, little is known about how bacteria maintain Ca 2+ homeostasis or how Ca 2+ acts as a signal. In this study, we identified a two-component regulatory system in P. aeruginosa PAO1, termed CarRS, that is induced at elevated Ca 2+ levels. CarRS modulates Ca 2+ signaling and Ca 2+ homeostasis through its regulatory targets, CarO and CarP. The results demonstrate that P. aeruginosa uses a two-component regulatory system to sense external Ca 2+ and relays that information for Ca 2+ -dependent cellular processes.
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- 2016
30. Genome Sequence of Janthinobacterium sp. CG23_2, a Violacein-Producing Isolate from an Antarctic Supraglacial Stream
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Nicolas P. Devitt, Thiruvarangan Ramaraj, Christine M. Foreman, Tatsuya Akiyama, Heidi J. Smith, and Michael J. Franklin
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0301 basic medicine ,Genetics ,Whole genome sequencing ,030106 microbiology ,Janthinobacterium sp ,Biology ,C content ,Genome ,03 medical and health sciences ,030104 developmental biology ,UV tolerance ,Prokaryotes ,Molecular Biology ,Gene ,Violacein ,Janthinobacterium sp. CG23_2 - Abstract
Here, we present the draft genome sequence for the violacein-producing Janthinobacterium sp. CG23_2 isolated from an Antarctic supraglacial stream. The genome is ~7.85 Mb, with a G+C content of 63.5%. The genome includes 7,247 candidate protein coding genes, which may provide insight into UV tolerance mechanisms.
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- 2016
31. Cutoff Value of Urinary Arginine Vasopressin for Nocturnal Polyuria in Elderly Men
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Kastunori Yoshida, Akihide Hirayama, Tatsuya Akiyama, Kazumasa Torimoto, Yoshihiko Hirao, and Kiyohide Fujimoto
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Male ,medicine.medical_specialty ,Vasopressin ,Urology ,Urinary system ,Urine ,chemistry.chemical_compound ,Risk Factors ,Internal medicine ,Humans ,Medicine ,Cutoff ,Nocturia ,Risk factor ,Aged ,Creatinine ,Polyuria ,business.industry ,Arginine Vasopressin ,Endocrinology ,chemistry ,Urine osmolality ,medicine.symptom ,business - Abstract
Objectives To determine the cutoff value of early-morning urinary arginine vasopressin (uAVP)/urinary creatinine (uCr) for patients with nocturnal polyuria (NP), and to investigate whether abnormal secretion of AVP at nighttime is a risk factor of NP in elderly men. Methods A total of 189 men older than 50 years of age with nocturia were enrolled. The frequency volume chart was recorded. The uAVP, urinary sodium, uCr, and osmolarity of a single urine sample voided at 6:00 am were measured in all cases. Two definitions of NP—nocturnal urine volume/24-hr production greater than 0.35 (NP index [NPI] definition) and a nocturnal urine volume of 0.9 mL/min × the sleeping duration or greater (NUV definition)—were used for analysis. Results uAVP/uCr was an independent predictor for NP according to the NPI and NUV definitions. The cutoff value of uAVP/uCr for NP was 23.4 pg/mL/Cr according to the NPI definition and 28.3 pg/mL/Cr according to the NUV definition. The sensitivity of the cutoff value according to the NPI and NUV definitions was 69% and 77%, respectively, and the specificity was 61% and 66%, respectively. In both NP definitions, 31% and 38% of the patients with a uAVP/uCr greater than the cutoff value showed NP. Significant differences in NUV and urine osmolarity, but not in uAVP/uCr and uNa/uCr, between the NP group and the non-NP group were found using both NP definitions. Conclusions We demonstrated that age and uAVP/uCr were independent predictive factors for nocturia in patients with NP. The cutoff value of uAVP/uCr is a useful screening marker for NP in elderly men with nocturia.
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- 2007
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32. New Technologies for Studying Biofilms
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Michael J. Franklin, Tatsuya Akiyama, Brian Bothner, and Connie B. Chang
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Microbiological Techniques ,Microbiology (medical) ,Physiology ,Aerobic bacteria ,Microorganism ,Cellular level ,Bacterial Physiological Phenomena ,Article ,Microbiology ,Laboratory flask ,Bacterial Proteins ,Genetics ,Enzyme level ,Bacteria ,General Immunology and Microbiology ,Ecology ,biology ,Biofilm ,Cell Biology ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Infectious Diseases ,Biofilms ,Biochemical engineering - Abstract
Bacteria have traditionally been studied as single-cell organisms. In laboratory settings, aerobic bacteria are usually cultured in aerated flasks, where the cells are considered essentially homogenous. However, in many natural environments, bacteria and other microorganisms grow in mixed communities, often associated with surfaces. Biofilms are comprised of surface-associated microorganisms, their extracellular matrix material, and environmental chemicals that have adsorbed to the bacteria or their matrix material. While this definition of a biofilm is fairly simple, biofilms are complex and dynamic. Our understanding of the activities of individual biofilm cells and whole biofilm systems has developed rapidly, due in part to advances in molecular, analytical, and imaging tools and the miniaturization of tools designed to characterize biofilms at the enzyme level, cellular level, and systems level.
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- 2015
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33. Decrease in nocturnal urinary levels of arginine vasopressin in patients with nocturnal polyuria
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Akihide Hirayama, Tatsuya Akiyama, Kiyohide Fujimoto, and Yoshihiko Hirao
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Male ,endocrine system ,medicine.medical_specialty ,Vasopressin ,Urology ,Urinary system ,Diuresis ,Urine ,urologic and male genital diseases ,Atrial natriuretic peptide ,Internal medicine ,Humans ,Medicine ,Nocturia ,Natriuretic Peptides ,Aged ,Polyuria ,urogenital system ,business.industry ,Osmolar Concentration ,Middle Aged ,Urination Disorders ,Brain natriuretic peptide ,Circadian Rhythm ,Arginine Vasopressin ,Endocrinology ,Creatinine ,Urine osmolality ,Female ,medicine.symptom ,business ,hormones, hormone substitutes, and hormone antagonists - Abstract
Objectives To elucidate whether heart function and endocrine levels of arginine vasopressin (AVP) or solute diuresis is associated with the nocturnal voided volume, and whether the urinary AVP could be a parameter for screening for nocturnal polyuria caused by AVP insufficiency. Methods A total of 50 patients were enrolled in this study. The blood and urine samples were obtained every 6 hours at 6 pm , 12 am , 6 am , and 12 pm . Atrial natriuretic peptide and brain natriuretic peptide were measured at admission. All voided urine samples were collected every 6 hours for examination. The evaluation items were AVP, osmolarity, sodium, potassium, chloride, and creatinine in blood and urine. Results The patients were classified into a group with nocturnal polyuria (n = 21) and a group without nocturnal polyuria (n = 25). There was no significant difference in atrial natriuretic peptide, brain natriuretic peptide, electrolytes in blood and urine, and plasma AVP of each sample between the two groups, but urinary AVP/urinary creatinine and urine osmolarity at 12 am and 6 am in the group with nocturnal polyuria were significantly lower than those in the group without nocturnal polyuria. The nocturnal voided volume correlated with urinary AVP/urinary creatinine level in the urine samples obtained at 12 am and 6 am . Conclusions The present data have demonstrated that the significant decrease in urinary AVP/urinary creatinine level at 6 am may contribute to the increased nocturnal voided volume followed by nocturia and that the circadian rhythm disorder of AVP can be predicted by a noninvasive test measuring urinary AVP/urinary creatinine in the urine voided early in the morning.
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- 2006
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34. Comparison of parameters to determine the cause of urinary disturbance in men with prostate volume less than 20 milliliters
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Shoji Samma, Ken Fujimoto, Yoshihisa Fukui, Akihide Hirayama, Akira Yamaguchi, and Tatsuya Akiyama
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Male ,medicine.medical_specialty ,Urology ,Urinary system ,urologic and male genital diseases ,Bladder outlet obstruction ,Predictive Value of Tests ,Prostate ,Lower urinary tract symptoms ,medicine ,Humans ,Body Weights and Measures ,Aged ,Ultrasonography ,Aged, 80 and over ,Gynecology ,medicine.diagnostic_test ,business.industry ,Diagnostic Techniques, Urological ,Middle Aged ,Urination Disorders ,medicine.disease ,Urodynamics ,Prostate-specific antigen ,medicine.anatomical_structure ,Transrectal ultrasonography ,International Prostate Symptom Score ,Outflow ,business - Abstract
Background : A pressure-flow study, although a slightly invasive procedure, can evaluate bladder outlet obstruction and detrusor contractility. This study was conducted in men with a non-enlarged prostate to determine the cause of urinary disturbance by less invasive examinations that might even- tually replace pressure-flow study. Methods : Thirty-six men with lower urinary tract symptoms were enrolled. Their prostate volume, estimated by transrectal ultrasonography, was less than 20 mL. All patients were examined using pressure-flow study, free-flowmetry, transrectal ultrasonography, prostate specific antigen and an interview using the International Prostate Symptom Score and Quality of Life Index. With determi- nation of the cause for urinary disturbance, parameters that correlated with outflow obstruction or impaired detrusor contractility were sought. Results : Twenty-one (60%) of the 36 men were judged as having outflow obstruction, and 16 of these 21 men had normal detrusor function. Impaired detrusor contractility was observed in 17 men. Only three of these 17 men had no outflow obstruction. Four patients had an unstable bladder. All these four had normal detrusor contractility, but had outflow obstruction. Among the parameters examined, only the maximum flow rate in a flow metrogram (Q max ) correlated significantly with the degree of outflow obstruction ( P = 0.04). The positive predictive value of Q max for outflow obstruction was 65% at a flow rate of less than 10 mL/s, and 100% at that of less than 5 mL/s. No parameter correlated with detrusor contractility. Conclusion : The only parameter that was a clear indicator of outflow obstruction was Q max . Other indicators of detrusor contractility should be sought.
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- 2002
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35. PCR Assay Specific for Chicken Feces
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Cindy R, Cisar, Tatsuya, Akiyama, Jonathan, Hatley, Lori, Arney, Nebojsa, Kezunovic, and Daniel, Owen
- Subjects
animal structures ,Article - Abstract
Bacteroidales are fecal anaerobic bacteria that are common in the digestive systems and feces of warm-blooded animals. Some strains of Bacteroidales have been reported to be host-specific. In this study, Bacteroidales strains from chicken feces were examined for their potential use as indicators of chicken fecal contamination. Bacteroidales 16S rRNA gene sequences from chicken feces were amplified, cloned and sequenced. Phylogenetic analysis was performed using these sequences and published Bacteroidales 16S rRNA gene sequences from human and bovine feces. Primers were designed based on putative chicken feces-specific 16S rRNA gene sequences and the primer pairs were tested for specificity in PCR assays. One set of primers, chBact F1 and chBact R16, specifically amplified DNA from chicken feces in a PCR assay, but did not amplify wild turkey, cat, bovine, or deer fecal DNAs. In addition, DNA from feces contaminated straw-based chicken litter produced a product in the PCR assay. However, DNA from feces contaminated wood shavings-based chicken litter was not amplified. The PCR assay described here may prove a useful tool for the detection of chicken feces and for source tracking in watersheds with fecal contamination.
- Published
- 2014
36. Renal arteriovenous fistula developing after tumor enucleation using a microwave tissue coagulator
- Author
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Shoji Samma, Yoshihisa Fukui, Tatsuya Akiyama, Ken Fujimoto, and Akihide Hirayama
- Subjects
Male ,Right flank ,medicine.medical_specialty ,Urology ,Fistula ,Arteriovenous fistula ,urologic and male genital diseases ,Renal Veins ,Gross hematuria ,Postoperative Complications ,Renal Artery ,Renal cell carcinoma ,Occlusion ,Electrocoagulation ,Humans ,Medicine ,Microwaves ,Carcinoma, Renal Cell ,Ultrasonography ,business.industry ,Middle Aged ,medicine.disease ,Kidney Neoplasms ,Surgery ,Feeding artery ,Arteriovenous Fistula ,Radiology ,Tomography, X-Ray Computed ,business ,Tumor enucleation - Abstract
With the increase in detection of incidental renal cell carcinoma, nephron-sparing surgery for small renal cell carcinomas is now recognized as one of the surgical options. We report a case of renal arteriovenous fistula developing after non-ischemic tumor enucleation of a small renal cell carcinoma using a microwave tissue coagulator. A 50-year-old Japanese man presented with right flank pain and gross hematuria. The patient had undergone non-ischemic tumor enucleation for right renal cell carcinoma, 2 cm in diameter, 1 month previously. Doppler ultrasound revealed the formation of an arteriovenous fistula at the enucleated portion. Transcatheter super-selective occlusion of the feeding artery was successfully performed with two metallic coils. The patient has been followed up with no sign of recanalization of the fistula. In this case, the tumor was located close to the renal hilus with thick arterial branches around the tumor. Additional microwave coagulations against arterial bleeding from the cutting surface might have been the cause of the fistula formation of this case. Non-ischemic tumor enucleation using a microwave tissue coagulator is a relatively easy and secure nephron-sparing surgical procedure. Excessive coagulation, however, should be avoided, since it might be the cause of unexpected postoperative vascular complications.
- Published
- 2001
- Full Text
- View/download PDF
37. The relationship between hyperhomocysteinemia and folic acid in hemodialysis patients
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Mari Masuda, Tatsuya Akiyama, Kiyotaka Sugihara, Tadayoshi Minami, Noboru Morita, Yoshihiro Motomiya, and Takuya Higashi
- Subjects
medicine.medical_specialty ,Hyperhomocysteinemia ,Folic acid ,business.industry ,Internal medicine ,medicine.medical_treatment ,medicine ,Hemodialysis ,medicine.disease ,business ,Gastroenterology - Abstract
維持血液透析患者66例について, 新たな動脈硬化性物質として注目されているhomocysteineおよびメチオニン代謝系基質である葉酸の血中濃度を測定した. 血漿homocysteine濃度は12.6-182.0μmol/l (平均45.6±31.9μmol/l) と全例で高値を示すと同時に著しい個体差を認めた. 一方, 血清葉酸濃度は2.7-26.8ng/ml (平均7.5±4.1ng/ml) とほとんどの症例で基準値の範囲内にあった. また, 血清葉酸濃度と血漿homocysteine濃度には負の相関 (r=-0.245; P=0.0445) が認められた. さらに, 血清葉酸濃度15ng/ml以上では40μmol/l以上の高度のhomocysteine高値例は認められなかった. しかし, 通常の食生活で血清葉酸濃度が15ng/ml以上に維持できている症例は3例 (4.5%) に過ぎず, 残りの63例 (95.5%) は血清葉酸濃度15ng/ml以下であった. 今回の結果からacquired hyperhomocysteinemiaの状態にある維持血液透析患者においては通常の食生活のみでは血漿homocysteine濃度を正常に保つに十分な葉酸濃度を得ることはできず, 動脈硬化予防のためには積極的な葉酸投与の必要性が示唆された.
- Published
- 2001
- Full Text
- View/download PDF
38. Diagnostic usefulness of endorectal magnetic resonance imaging with dynamic contrast‐enhancement in patients with localized prostate cancer: Mapping studies with biopsy specimens
- Author
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Satoru Kitano, Nobumichi Tanaka, Megumi Takewa, Shoji Samma, Tatsuya Akiyama, Eigoro Okajima, and Masanori Joko
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Male ,medicine.medical_specialty ,Urology ,Dynamic imaging ,Prostate cancer ,Biopsy ,Humans ,Medicine ,In patient ,Aged ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Biopsy, Needle ,Rectum ,Prostatic Neoplasms ,Magnetic resonance imaging ,Middle Aged ,Image Enhancement ,medicine.disease ,Magnetic Resonance Imaging ,Dynamic contrast ,Evaluation Studies as Topic ,Histopathology ,Radiology ,business ,Endorectal coil - Abstract
Background New diagnostic criteria for dynamic magnetic resonance (MR) imaging in prostate cancer are presented. The diagnostic usefulness of endorectal MR imaging with dynamic contrast-enhancement in localized prostate cancer and the validity of these criteria were evaluated. Methods Eighteen untreated patients who were suspected of localized prostate cancer were included in the study. They received endorectal dynamic MR imaging before systematic sextant needle biopsy. First. a mapping study with the findings of MR images and histopathology of biopsy specimens was performed in eight patients out of 18 to compare the difference in T2-weighted images with the endorectal coil and the body coil in the same individuals. Second, another mapping study was performed in all 18 patients by analyzing the findings of endorectal dynamic MR images. For the diagnosis of prostate cancer in MR imaging, we offered diagnostic criteria from our experience in addition to those in plain T2-weighted images from the literature. Results The overall diagnostic rates of endorectal dynamic MR imaging were 88.9% in accuracy, 100% in sensitivity, and 81.8% in specificity. In the comparison of the endorectal and body coils in T2-weighted images in eight patients, there was no difference in the diagnostic rates except for one more histopathologic false positive portion in endorectal MR imaging. In the second mapping study in 18 patients, the diagnostic rates were 92.6% in accuracy, 88.9% in sensitivity and 93.3% in specificity. Endorectal dynamic imaging raised the diagnostic sensitivity from 77.8 to 88.9%. Conclusion The data demonstrated the validity of this diagnostic criteria and the diagnostic usefulness of endorectal dynamic MR imaging in localized prostate cancer.
- Published
- 1999
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39. Comparison of serum levels of pyridinoline and pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen as markers of bone resorption in patients receiving maintenance hemodialysis
- Author
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Tatsuya Akiyama, Kagebayashi Y, Katsunori Yoshida, Eigoro Okajima, Shoji Samma, Nobumichi Tanaka, Masaaki Arima, and Masanori Joko
- Subjects
medicine.medical_specialty ,Pyridinoline ,Physiology ,business.industry ,medicine.medical_treatment ,Radioimmunoassay ,Maintenance hemodialysis ,Bone resorption ,chemistry.chemical_compound ,Endocrinology ,N-terminal telopeptide ,chemistry ,Nephrology ,Physiology (medical) ,Internal medicine ,medicine ,In patient ,Hemodialysis ,business ,Type I collagen - Abstract
Background Serum levels of pyridinoline, measured by high-performance liquid chromatography, and pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), measured by a newly developed radioimmunoassay kit, were compared and analyzed to determine whether ICTP can replace pyridinoline as a marker of bone resorption in hemodialysis patients.
- Published
- 1998
- Full Text
- View/download PDF
40. Draft Genome Sequence and Description of Janthinobacterium sp. Strain CG3, a Psychrotolerant Antarctic Supraglacial Stream Bacterium
- Author
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Michael J. Franklin, Karen W. Davenport, Tracy Erkkila, Yan Xu, Lynne Goodwin, Tanja Woyke, Christine M. Foreman, Heidi J. Smith, Hajnalka E. Daligault, Tatsuya Akiyama, Patrick S. G. Chain, Hazuki Teshima, and Wei Gu
- Subjects
Whole genome sequencing ,0303 health sciences ,biology ,030306 microbiology ,Strain (biology) ,Janthinobacterium sp ,biology.organism_classification ,Microbiology ,03 medical and health sciences ,Genetics ,Prokaryotes ,Molecular Biology ,Bacteria ,Organism ,030304 developmental biology - Abstract
Here we present the draft genome sequence of Janthinobacterium sp. strain CG3, a psychrotolerant non-violacein-producing bacterium that was isolated from the Cotton Glacier supraglacial stream. The genome sequence of this organism will provide insight as to the mechanisms necessary for bacteria to survive in UV-stressed icy environments.
- Published
- 2013
- Full Text
- View/download PDF
41. The tetA gene decreases tigecycline sensitivity of Salmonella enterica isolates
- Author
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Tatsuya Akiyama, Ashraf A. Khan, and Jacqueline Presedo
- Subjects
Microbiology (medical) ,Salmonella ,Tetracycline ,Minocycline ,Tigecycline ,Microbial Sensitivity Tests ,medicine.disease_cause ,Antiporters ,Microbiology ,Frameshift mutation ,Minimum inhibitory concentration ,Bacterial Proteins ,Drug Resistance, Bacterial ,polycyclic compounds ,medicine ,Humans ,Pharmacology (medical) ,Gene ,biology ,Salmonella enterica ,General Medicine ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Anti-Bacterial Agents ,Infectious Diseases ,Salmonella Infections ,Food Microbiology ,medicine.drug - Abstract
To determine the association of tetracycline resistance determinants with tigecycline sensitivity, tetracycline-resistant Salmonella spp. isolated from clinical and food samples were tested for the presence of tetracycline resistance determinants, tigecycline sensitivity, and the impact of tetA on tigecycline resistance. In addition, the impacts of multiple resistance mechanisms on tigecycline resistance were determined using an isolate with ramR mutation. Of the 49 tetracycline-resistant Salmonella isolates screened, 32 were positive for tetA , 13 were positive for tetB , 2 were positive for tetC and 1 isolate was positive for both tetA and tetB . The minimum inhibitory concentration (MIC) of tigecycline for tetA -carrying isolates ranged from 0.19mg/L to 3mg/L (mode 0.75mg/L), whereas the MIC of tigecycline for tetB -carrying isolates ranged from 0.064mg/L to 0.5mg/L (modes 0.25mg/L and 0.38mg/L, excluding the isolate with both tetA and tetB ). Double frameshift mutations in codons 201, 202 and 203 were observed in partial sequences of the tetA genes in these strains and the majority of published tetA gene sequences. Curing of the tetA genes from three isolates reduced the tigecycline MICs, whilst deletion of ramR increased tigecycline MICs. This study indicates that the tetA gene decreases sensitivity to tigecycline in Salmonella spp. at a low level. With additional resistance mechanisms, tetA -carrying strains can reach the breakpoint for tigecycline resistance.
- Published
- 2013
42. Molecular characterization of strains of fluoroquinolone-resistant Salmonella enterica serovar Schwarzengrund carrying multidrug resistance isolated from imported foods
- Author
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Tatsuya Akiyama and Ashraf A. Khan
- Subjects
Microbiology (medical) ,DNA, Bacterial ,Salmonella ,Molecular Sequence Data ,Mutation, Missense ,Drug resistance ,Microbial Sensitivity Tests ,medicine.disease_cause ,Microbiology ,Antibiotic resistance ,Bacterial Proteins ,Drug Resistance, Multiple, Bacterial ,medicine ,Humans ,Pharmacology (medical) ,Etest ,Pharmacology ,biology ,Salmonella enterica ,Sequence Analysis, DNA ,biochemical phenomena, metabolism, and nutrition ,bacterial infections and mycoses ,biology.organism_classification ,Virology ,Anti-Bacterial Agents ,Multiple drug resistance ,Ciprofloxacin ,Infectious Diseases ,Food Microbiology ,Efflux ,medicine.drug ,Fluoroquinolones - Abstract
To determine the fluoroquinolone resistance determinants in Salmonella enterica serovar Schwarzengrund from imported foods.Antibiotic susceptibility of Salmonella Schwarzengrund to 16 antibiotics was examined using disc agar diffusion and Etest. Quinolone resistance determinants were examined by sequence analysis of gyrA, gyrB, parC and parE, PCR amplification of qnrA, qnrB and qnrS, and expression of acrB, ramA, marA, soxS and rob using quantitative RT-PCR. The contribution of efflux pump activities to antibiotic resistance was determined by the addition of carbonyl cyanide m-chlorophenylhydrazone (CCCP). The effect of ramR deletion on ciprofloxacin resistance was determined by complementing with wild-type ramR.Salmonella strains 30 and 487 were susceptible to ciprofloxacin and had a single mutation in gyrA as compared with strain 75, which was highly resistant to ciprofloxacin and had a double mutation in gyrA. Increased expression of ramA was associated with high resistance to ciprofloxacin. Strain 75 had a deletion of 315 bp in the ramR gene, which regulates ramA expression. Overexpression of ramA was possibly related to a loss of ramR. Introduction of ramR decreased the MIC of ciprofloxacin from 48 to 24 mg/L. The addition of CCCP did not reduce antibiotic resistance. To our knowledge, this study reports for the first time the natural deletion of ramR in Salmonella Schwarzengrund.This study indicates that fluoroquinolone-resistant Salmonella are prevalent in imported food. Double mutations in gyrA and a loss of ramR were associated with high-level quinolone resistance in multidrug-resistant Salmonella Schwarzengrund strain 75.
- Published
- 2011
43. Molecular characterisation of high-level ciprofloxacin-resistant Salmonella enterica with multiple antibiotic resistance and class 1 integrons isolated from imported foods
- Author
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Ashraf A. Khan, Tatsuya Akiyama, Christine S. West, and Mohamed S. Nawaz
- Subjects
Microbiology (medical) ,Salmonella enterica ,General Medicine ,Microbial Sensitivity Tests ,Biology ,biology.organism_classification ,Microbiology ,Bacterial Typing Techniques ,Integrons ,Ciprofloxacin ,Infectious Diseases ,Antibiotic resistance ,Seafood ,Genes, Bacterial ,Drug Resistance, Multiple, Bacterial ,medicine ,Food Microbiology ,Humans ,Pharmacology (medical) ,Spices ,medicine.drug - Published
- 2011
44. Broad-host-range plasmids in treated wastewater effluent and receiving streams
- Author
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Kyle L. Asfahl, Tatsuya Akiyama, and Mary C. Savin
- Subjects
Transposable element ,Environmental Engineering ,Indicator bacteria ,Management, Monitoring, Policy and Law ,Biology ,medicine.disease_cause ,Waste Disposal, Fluid ,law.invention ,Microbiology ,Plasmid ,Rivers ,law ,Drug Resistance, Bacterial ,medicine ,Waste Management and Disposal ,Effluent ,Gene ,Escherichia coli ,Polymerase chain reaction ,Water Science and Technology ,Bacteria ,Pollution ,Anti-Bacterial Agents ,Horizontal gene transfer ,Water Microbiology ,Water Pollutants, Chemical ,Environmental Monitoring ,Plasmids - Abstract
The occurrence of broad-host-range (BHR) plasmid amplicons belonging to incompatibility (Inc) groups IncA/C, IncN, IncP, and IncW in two wastewater treatment plant (WWTP) effluents and effluent-receiving streams in Northwest Arkansas, Mud Creek and Spring Creek, was determined. Community DNA captured on filter membranes and plasmid DNA extracted from antibiotic-resistant Escherichia coli isolated from Mud Creek was used for polymerase chain reaction at amplification of partial gene sequences specific to BHR plasmids. IncP plasmid amplicons were detected in effluent and downstream sites in both streams, while IncN and IncW plasmid amplicons were detected in Spring Creek in effluent and downstream but not upstream. IncA/C plasmid amplicons, in contrast, were detected at all sites, including upstream in most samples in Spring Creek and in one sample from Mud Creek. One IncP and two IncN were the only BHR plasmid amplicons found in 85 screened antibiotic-resistant E. coli isolates, and were detected only in isolates from effluent and downstream samples. Broad-host-range plasmids frequently carry antibiotic-resistance genes and can facilitate horizontal transfer of those genes. While BHR plasmids have been detected in WWTPs, WWTPs do not target these genetic elements for destruction. This study indicates that BHR plasmids are in WWTP effluent and are introducing BHR plasmids into streams. Additionally, species other than E. coli may be better targets as indicator bacteria for future studies of the impact of treated effluent on environmental dissemination of BHR plasmids.
- Published
- 2011
45. Molecular characterization of Salmonella enterica serovar Saintpaul isolated from imported seafood, pepper, environmental and clinical samples
- Author
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Ashraf A. Khan, Rossina Stefanova, Tatsuya Akiyama, and Chorng-Ming Cheng
- Subjects
Serotype ,Salmonella ,Molecular Sequence Data ,Virulence ,Food Contamination ,medicine.disease_cause ,Microbiology ,Plasmid ,Bacterial Proteins ,Pulsed-field gel electrophoresis ,medicine ,Environmental Microbiology ,Animals ,Humans ,Replicon ,Phylogeny ,biology ,Salmonella enterica ,Kanamycin ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Anti-Bacterial Agents ,Seafood ,Salmonella Infections ,Capsicum ,Food Science ,medicine.drug - Abstract
A total of 39 Salmonella enterica serovar Saintpaul strains from imported seafood, pepper and from environmental and clinical samples were analyzed for the presence of virulence genes, antibiotic resistance, plasmid and plasmid replicon types. Pulsed-field gel electrophoresis (PFGE) fingerprinting using the XbaI restriction enzyme and plasmid profiling were performed to assess genetic diversity. None of the isolates showed resistance to ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin, sulfisoxazole, and tetracycline. Seventeen virulence genes were screened for by PCR. All strains were positive for 14 genes (spiA, sifA, invA, spaN, sopE, sipB, iroN, msgA, pagC, orgA, prgH, lpfC, sitC, and tolC) and negative for three genes (spvB, pefA, and cdtB). Twelve strains, including six from clinical samples and six from seafood, carried one or more plasmids. Large plasmids, sized greater than 50 kb were detected in one clinical and three food isolates. One plasmid was able to be typed as IncI1 by PCR-based replicon typing. There were 25 distinct PFGE-XbaI patterns, clustered to two groups. Cluster A, with 68.5% similarity mainly consists of clinical isolates, while Cluster C, with 67.6% similarity, mainly consisted of shrimp isolates from India. Our findings indicated the genetic diversity of S. Saintpaul in clinical samples, imported seafood, and the environment and that this serotype possesses several virulent genes and plasmids which can cause salmonellosis.
- Published
- 2010
46. Populations of antibiotic-resistant coliform bacteria change rapidly in a wastewater effluent dominated stream
- Author
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Tatsuya Akiyama and Mary C. Savin
- Subjects
Veterinary medicine ,Ofloxacin ,Environmental Engineering ,Sulfamethoxazole ,Waste Disposal, Fluid ,Trimethoprim ,Microbiology ,Rivers ,Drug Resistance, Bacterial ,medicine ,Escherichia coli ,Environmental Chemistry ,Waste Management and Disposal ,Effluent ,biology ,Tetracycline ,biology.organism_classification ,Pollution ,Coliform bacteria ,Anti-Bacterial Agents ,Wastewater ,Sewage treatment ,Water Microbiology ,Bacteria ,Water Pollutants, Chemical ,medicine.drug ,Waste disposal ,Environmental Monitoring - Abstract
Incomplete elimination of bacteria and pharmaceutical drugs during wastewater treatment results in the entry of antibiotics and antibiotic-resistant bacteria into receiving streams with effluent inputs. In Mud Creek in Fayetteville, AR, ofloxacin, trimethoprim, and sulfamethoxazole have been detected in water and sediment, and tetracycline has been detected in sediment downstream of treated effluent input. These antibiotics have been measured repeatedly, but at low concentrations (
- Published
- 2010
47. [Prostate cancer and left ectopic ureter opening to seminal vesicle with left renal agenesis: a case report]
- Author
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Yasushi, Nakai, Masahiro, Tanaka, Motokiyo, Yoshikawa, Nobumichi, Tanaka, Akihide, Hirayama, Kiyohide, Fujimoto, Yoshihiko, Hirao, Tsuyoshi, Inoue, and Tatsuya, Akiyama
- Subjects
Male ,Prostatectomy ,Treatment Outcome ,Humans ,Prostatic Neoplasms ,Seminal Vesicles ,Adenocarcinoma ,Middle Aged ,Ureter ,Kidney - Abstract
We report a case of prostate cancer and left ectopic ureter opening to seminal vesicle with left renal agenesis. A 62-year-old man was admitted to our hospital for treatment of prostate cancer with cyst formation. On the rectal examination, a cystic tumor was palpable on the left side of prostate. The left kidney was not detected by intravenous pyelography and ultrasonography. Magnetic resonance imaging revealed a retrovesical cystic lesion in the left side. Total prostatectomy and left ureterectomy were performed under the diagnosis of clinical T1cN0M0 prostate cancer and left ectopic ureter opening to seminal vesicle with left renal agenesis. The pathological findings showed well differentiated adenocarcinoma, Gleason score 3 + 3, and left ectopic ureter entering into the seminal vesicle and left renal agenesis. The patient was well 39 months after the total prostatectomy and left ureterectomy without evidence of recurrence. There have been no cases of the association of this urogenital anomaly, such as ectopic ureter opening to seminal vesicle with renal agenesis and prostate cancer and the combined management of both. Our case seems to be first case in the Japanese literature.
- Published
- 2009
48. Increase in 24-hour urine production/weight causes nocturnal polyuria due to impaired function of antidiuretic hormone in elderly men
- Author
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Mitsuru, Tani, Akihide, Hirayama, Kiyohide, Fujimoto, Kazumasa, Torimoto, Tatsuya, Akiyama, and Yoshihiko, Hirao
- Subjects
Arginine Vasopressin ,Male ,Polyuria ,Creatinine ,Health Status ,Drinking ,Humans ,Nocturia ,Middle Aged ,Urine ,Life Style ,Aged - Abstract
The goals of the present study were to evaluate whether the different function of endogenous antidiuretic hormone (arginine vasopressin; AVP) results in the difference in 24-h production/weight and to make indexes of lifestyle advice for patients with nocturia due to nocturnal polyuria (NP).A total of 205 male patients over 50 years of age were enrolled in the study. Frequency volume chart and fluid intake (time and volume) were recorded under unconditioned status. All patients submitted single voided urine sample at 06.00 hours. Urinary AVP (uAVP), sodium (uNa), creatinine (uCr), and osmolarity were measured. Patients were divided into four groups according to 24-h urine production/weight as follows: 24-h production/weight40, 24-h production/weight: more than 30 to 40, 24-h production/weight: more than 20 to 30, 24-h production/weight: 20 or less.The data of 174 eligible patients were finally evaluated. Although there were no differences in uAVP/uCr and uNa/uCr among the groups, the nocturnal voided volume (NUV) increased with the increase in 24-h production/weight. Age, uAVP/uCr, 24-hr production/weight of more than 20 to 30, and 24-h production/weight of 20 or less were independent factors for NP. NUV did not correlate with 24-h drinking volume in any group.Our data suggested that the increased 24-h urine production/weight was apparently a risk factor for NP. We attributed this phenomenon to deterioration of the function of AVP.
- Published
- 2008
49. Resuscitation of Pseudomonas aeruginosa from dormancy requires hibernation promoting factor (PA4463) for ribosome preservation.
- Author
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Tatsuya Akiyama, Williamson, Kerry S., Schaefer, Robert, Pratt, Shawna, Chang, Connie B., and Franklin, Michael J.
- Subjects
PSEUDOMONAS aeruginosa ,RIBOSOMES ,ANTIBIOTICS ,PROTEIN synthesis ,HIBERNATION - Abstract
Pseudomonas aeruginosa biofilm infections are difficult to treat with antibiotic therapy in part because the biofilms contain subpopulations of dormant antibiotic-tolerant cells. The dormant cells can repopulate the biofilms following alleviation of antibiotic treatments. While dormant, the bacteria must maintain cellular integrity, including ribosome abundance, to reinitiate the de novo protein synthesis required for resuscitation. Here, we demonstrate that the P. aeruginosa gene PA4463 [hibernation promoting factor (HPF)], but not the ribosome modulation factor (PA3049), is required for ribosomal RNA preservation during prolonged nutrient starvation conditions. Single-cell-level studies using fluorescence in situ hybridization (FISH) and growth in microfluidic drops demonstrate that, in the absence of hpf, the rRNA abundances of starved cells decrease to levels that cause them to lose their ability to resuscitate from starvation, leaving intact nondividing cells. P. aeruginosa defective in the stringent response also had reduced ability to resuscitate from dormancy. However, FISH analysis of the starved stringent response mutant showed a bimodal response where the individual cells contained either abundant or low ribosome content, compared with the wild-type strain. The results indicate that ribosome maintenance is key for maintaining the ability of P. aeruginosa to resuscitate from starvation-induced dormancy and that HPF is themajor factor associatedwith P. aeruginosa ribosome preservation. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
50. 21211 System design and functional evaluation of power assist apparatus for an upper limb
- Author
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Daisuke Tsunoda, Hiroo Ichikawa, Jun Setoguchi, Tadaaki Ikehara, Eiichirou Tanaka, Kazuhisa Ito, Tatsuya Akiyama, and Shozo Saegusa
- Subjects
Functional evaluation ,medicine.anatomical_structure ,Computer science ,medicine ,Upper limb ,Systems design ,Simulation ,Power (physics) - Published
- 2010
- Full Text
- View/download PDF
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