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Sootome H, Muraoka H, Aoyagi Y, Kato M, Hirai H. Covalent FGFR inhibitor futibatinib exhibits sustained antitumor effects compared with ATP-competitive inhibitors by being less prone to ontarget resistance. Eur J Cancer 2022. [DOI: 10.1016/s0959-8049(22)01005-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Mirtl M, T Borer E, Djukic I, Forsius M, Haubold H, Hugo W, Jourdan J, Lindenmayer D, McDowell WH, Muraoka H, Orenstein DE, Pauw JC, Peterseil J, Shibata H, Wohner C, Yu X, Haase P. Genesis, goals and achievements of Long-Term Ecological Research at the global scale: A critical review of ILTER and future directions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 626:1439-1462. [PMID: 29898550 DOI: 10.1016/j.scitotenv.2017.12.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/28/2017] [Accepted: 12/01/2017] [Indexed: 06/08/2023]
Abstract
Since its founding in 1993 the International Long-term Ecological Research Network (ILTER) has gone through pronounced development phases. The current network comprises 44 active member LTER networks representing 700 LTER Sites and ~80 LTSER Platforms across all continents, active in the fields of ecosystem, critical zone and socio-ecological research. The critical challenges and most important achievements of the initial phase have now become state-of-the-art in networking for excellent science. At the same time increasing integration, accelerating technology, networking of resources and a strong pull for more socially relevant scientific information have been modifying the mission and goals of ILTER. This article provides a critical review of ILTER's mission, goals, development and impacts. Major characteristics, tools, services, partnerships and selected examples of relative strengths relevant for advancing ILTER are presented. We elaborate on the tradeoffs between the needs of the scientific community and stakeholder expectations. The embedding of ILTER in an increasingly collaborative landscape of global environmental observation and ecological research networks and infrastructures is also reflected by developments of pioneering regional and national LTER networks such as SAEON in South Africa, CERN/CEOBEX in China, TERN in Australia or eLTER RI in Europe. The primary role of ILTER is currently seen as a mechanism to investigate ecosystem structure, function, and services in response to a wide range of environmental forcings using long-term, place-based research. We suggest four main fields of activities and advancements for the next decade through development/delivery of a: (1) Global multi-disciplinary community of researchers and research institutes; (2) Strategic global framework and strong partnerships in ecosystem observation and research; (3) Global Research Infrastructure (GRI); and (4) a scientific knowledge factory for societally relevant information on sustainable use of natural resources.
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Muraoka H, Yoshimura C, Tsuji S, Hashimoto A, Mizutani T, Ohkubo S, Matsuo K, Utsugi T, Iwasawa Y. TAS4464, a novel highly potent NEDD8 activating enzyme inhibitor, demonstrates anti-tumor efficacy in rituximab-resistant double-hit lymphoma models. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)33052-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kotaki T, Nishimura N, Ozawa M, Fujimori A, Muraoka H, Ogawa S, Korenaga T, Suzuki E, Oishi Y, Shibasaki Y. Synthesis of highly refractive and highly fluorescent rigid cyanuryl polyimines with polycyclic aromatic hydrocarbon pendants. Polym Chem 2016. [DOI: 10.1039/c5py01920f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of rigid cyanuryl polyimines, polyguanamines (PGs) bearing polycyclic aromatic hydrocarbon pendants were successfully synthesized from 2-substituted 4,6-dichloro-1,3,5-triazine and aromatic diamine monomers.
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Fujino T, Hatano M, Yao A, Nitta D, Muraoka H, Minatsuki S, Imamura T, Inaba T, Maki H, Kinugawa K, Komuro I. The Reliability of 6-Minute Walk Test to Predict Exercise Capacity in Patients With Pulmonary Hypertension. J Heart Lung Transplant 2015. [DOI: 10.1016/j.healun.2015.01.965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Ohkubo S, Muraoka H, Kodama Y, Ito K, Ito S, Hashimoto A, Yoshimura C, Utsugi T. 592 TAS-116, a highly selective inhibitor of heat shock protein 90a/β, inhibits tumor growth in biliary tract cancer mouse models. Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)70718-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Hirahara N, Kaneda T, Sasaki Y, Fukuda T, Ito K, Kawashima Y, Muraoka H, Muramatsu T. Characteristic MR findings of rheumatic arthritis in the temporomandibular joints. J Oral Maxillofac Surg 2014. [DOI: 10.1016/j.joms.2014.06.393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Muraoka H, Kaneda T, Sasaki Y, Kawashima Y, Fukuda T, Muramatsu T, Ito K, Hirahara N. Relationship between joint effusion and parotid lymph nodes in temporomandibular disorders. J Oral Maxillofac Surg 2014. [DOI: 10.1016/j.joms.2014.06.398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kaneda T, Kawashima Y, Sasaki Y, Suemitsu M, Okada H, Hayakawa Y, Sakae T, Muraoka H, Hirahara N. Clinical application of parameteric X-ray in diagnostic imaging: Preliminary study. J Oral Maxillofac Surg 2014. [DOI: 10.1016/j.joms.2014.06.312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Hiroshima Y, Miyamoto H, Nakamura F, Masukawa D, Yamamoto T, Muraoka H, Kamiya M, Yamashita N, Suzuki T, Matsuzaki S, Endo I, Goshima Y. The protein Ocular albinism 1 is the orphan GPCR GPR143 and mediates depressor and bradycardic responses to DOPA in the nucleus tractus solitarii. Br J Pharmacol 2014; 171:403-14. [PMID: 24117106 DOI: 10.1111/bph.12459] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 09/12/2013] [Accepted: 09/30/2013] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND AND PURPOSE L-DOPA is generally considered to alleviate the symptoms of Parkinson's disease by its conversion to dopamine. We have proposed that DOPA is itself a neurotransmitter in the CNS. However, specific receptors for DOPA have not been identified. Recently, the gene product of ocular albinism 1 (OA1) was found to exhibit DOPA-binding activity. Here, we have investigated whether OA1 is a functional receptor of DOPA in the nucleus tractus solitarii (NTS). EXPERIMENTAL APPROACH We examined immunohistochemical expression of OA1 in the NTS, and the effects of DOPA microinjected into the depressor sites of NTS on blood pressure and heart rate in anaesthetized rats, with or without prior knock-down of OA1 in the NTS, using shRNA against OA1. KEY RESULTS Using a specific OA1 antibody, OA1-positive cells and nerve fibres were found in the depressor sites of the NTS. OA1 expression in the NTS was markedly suppressed by microinjection into the NTS of adenovirus vectors carrying the relevant shRNA sequences against OA1. In animals treated with OA1 shRNA, depressor and bradycardic responses to DOPA, but not those to glutamate, microinjected into the NTS were blocked. Bilateral injections into the NTS of DOPA cyclohexyl ester, a competitive antagonist against OA1, suppressed phenylephrine-induced bradycardic responses without affecting blood pressure responses. CONCLUSION AND IMPLICATIONS OA1 acted as a functional receptor for DOPA in the NTS, mediating depressor and bradycardic responses. Our results add to the evidence for a central neurotransmitter role for DOPA, without conversion to dopamine.
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Maki H, Hatano M, Muraoka H, Minatsuki S, Fujino T, Imamura T, Inaba T, Yao A, Kinugawa K, Komuro I. Pulmonary Vasodilators Can Reverse Out-of-Proportional Pulmonary Hypertension in Patients with Left Cardiac Disease. J Heart Lung Transplant 2014. [DOI: 10.1016/j.healun.2014.01.840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Imamura T, Kinugawa K, Hatano M, Muraoka H, Fujino T, Inaba T, Maki H, Kinoshita O, Nawata K, Kyo S, Ono M. Low Cardiac Output Stimulates Vasopressin Release in Patients with Stage D Heart Failure - Its Relevance to Poor Prognosis and Reversal by Surgical Treatment. J Heart Lung Transplant 2014. [DOI: 10.1016/j.healun.2014.01.168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Kato N, Kinugawa K, Endo M, Kagami Y, Imamura T, Muraoka H, Minatsuki S, Inaba T, Maki H, Shiga T, Hatano M, Yao A, Kyo S, Komuro I, Ono M. Differential Impacts of Implantable Ventricular Assist Device on Quality of Life and Depression in Patients with Heart Failure and Their Caregivers. J Heart Lung Transplant 2013. [DOI: 10.1016/j.healun.2013.01.277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Tsugawa H, Suzuki H, Muraoka H, Ikeda F, Hirata K, Matsuzaki J, Saito Y, Hibi T. Enhanced bacterial efflux system is the first step to the development of metronidazole resistance in Helicobacter pylori. Biochem Biophys Res Commun 2010; 404:656-60. [PMID: 21147064 DOI: 10.1016/j.bbrc.2010.12.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 12/07/2010] [Indexed: 10/18/2022]
Abstract
Although metronidazole (Mtz) is an important component of Helicobacter pylori eradication regimens, it has been pointed out that the increasing use of Mtz may result in increase in the incidence of Mtz-resistant strains. The present study was designed to examine the initial mechanism of resistance acquisition of H. pylori to Mtz. After 10 Mtz-susceptible strains were cultured on plates containing sub-inhibitory concentrations of Mtz, the MIC of Mtz for 9 of the 10 strains increased to levels of the Mtz-resistant strains. In the Mtz-resistance-induced strains, the expression of the TolC efflux pump (hefA) was significantly increased under Mtz exposure, without the reduction of the Mtz-reductive activity. Our finding suggests that overexpression of hefA may be the initial step in the acquisition of Mtz resistance in H. pylori.
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Hirata K, Suzuki H, Nishizawa T, Tsugawa H, Muraoka H, Saito Y, Matsuzaki J, Hibi T. Contribution of efflux pumps to clarithromycin resistance in Helicobacter pylori. J Gastroenterol Hepatol 2010; 25 Suppl 1:S75-9. [PMID: 20586871 DOI: 10.1111/j.1440-1746.2009.06220.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND AIMS Although clarithromycin (CLR) is one of the most commonly recommended component drugs of Helicobacter pylori eradication regimens, the prevalence of CLR-resistant H. pylori has been increasing. It is well known that CLR resistance is associated with point mutations in 23S rRNA, but an active multidrug efflux mechanism of H. pylori may also play a role in its drug resistance. At least four gene clusters have been identified as efflux pump systems in H. pylori and the present study was designed to investigate their role in the CLR resistance of clinical isolates of H. pylori. METHODS Fifteen CLR-resistant H. pylori strains (minimal inhibitory concentration [MIC]>or= 1 microg/mL) isolated from patients at Keio University Hospital were examined for expression of efflux pump mRNA by real-time polymerase chain reaction. In addition, the MIC of CLR in the presence or absence of Phe-Arg-beta-naphthylamide (PAbetaN), an efflux pump inhibitor (EPI), were determined. RESULTS In all 15 strains, efflux pump mRNA was expressed, and the MIC of CLR were decreased by using EPI, despite possessing 23s rRNA point mutations. In addition, the MIC of CLR was decreased by the EPI in a concentration-dependent fashion. CONCLUSION The efflux pump of H. pylori is associated with the development of resistance to CLR, in addition to 23S rRNA point mutations. Efflux pumps could be a novel target for reversing drug resistance in H. pylori.
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Greaves SJ, Mizuno T, Muraoka H. Transition Formation in Heat-Assisted Magnetic Recording. ACTA ACUST UNITED AC 2010. [DOI: 10.3379/msjmag.1003r002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Hongo K, Goto T, Muraoka H, Kakizawa Y, Sakai K. IN10-MO-01 Surgery for the cavernous angioma in the brainstem, selection of a safe surgical approach and surgical results. J Neurol Sci 2009. [DOI: 10.1016/s0022-510x(09)70056-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Tsunoda A, Muraoka H, Yamada M, Komatsuzaki A. Helical CT and its three-dimensional image: Application for image-guided surgery in middle cranial fossa approach. MINIM INVASIV THER 2009. [DOI: 10.3109/13645709709153082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Suzuki S, Suzuki H, Nishizawa T, Kaneko F, Ootani S, Muraoka H, Saito Y, Kobayashi I, Hibi T. Past rifampicin dosing determines rifabutin resistance of Helicobacter pylori. Digestion 2009; 79:1-4. [PMID: 19142036 DOI: 10.1159/000191204] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 11/25/2008] [Indexed: 02/04/2023]
Abstract
BACKGROUND Recently, the number of Helicobacter pylori isolates showing antibiotic resistance has been increasing. Rifabutin (RFB) is one of the possible candidates for H. pylori eradication. In the present study, the RFB minimum inhibitory concentrations (MICs) and the resistance-determining genes to RFB (rpoB) were examined to clarify the relationship between drug MICs, rpoB mutations, and past history of rifampicin (RFP) treatment. METHODS The MICs of RFB and rpoB mutations were examined for 48 strains with failure of H. pylori eradication in the University Hospital and 46 isolated from patients at a specialized hospital for chronic respiratory diseases without past H. pylori eradication. Past RFP treatment was also examined. RESULTS Eight of 94 strains showed high RFB MICs and 6 of the 8 strains showed rpoB point mutations. Although no strains showed high RFB MICs among 48 strains from the patients in the University Hospital, all 7 strains isolated from patients with past RFP treatment showed high RFB MICs (>or=0.12 mg/l). CONCLUSION Although RFB might be a potential candidate component of a new H. pylori eradication regimen following the first- or second-line failure, it should be used after examining a past history of RFP treatment.
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Ito T, Kobayashi D, Uchida K, Takemura T, Nagaoka S, Kobayashi I, Yokoyama T, Ishige I, Ishige Y, Ishida N, Furukawa A, Muraoka H, Ikeda S, Sekine M, Ando N, Suzuki Y, Yamada T, Suzuki T, Eishi Y. Helicobacter pylori invades the gastric mucosa and translocates to the gastric lymph nodes. J Transl Med 2008; 88:664-81. [PMID: 18475258 DOI: 10.1038/labinvest.2008.33] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Helicobacter pylori has been considered to be non-invasive and to rarely infiltrate the gastric mucosa, even though there is an active Th1 immune response in the lamina propria of the H. pylori-infected stomach. To elucidate whether H. pylori invades the lamina propria and translocates to the gastric lymph nodes, we examined H. pylori in formalin-fixed and paraffin-embedded tissue sections of stomach and gastric lymph nodes obtained from 51 cancer patients using real-time PCR and immunohistochemistry (IHC) with a novel anti-H. pylori monoclonal antibody that recognizes lipopolysaccharides. Fresh gastric lymph nodes were used to culture for H. pylori. In 46 patients with H. pylori in the stomach, the bacterium was found in the lymph nodes from 21 patients by culture, 37 patients by PCR, and 29 patients by IHC. H. pylori captured by macrophages was found in the lamina propria of 39 patients. In the lymph nodes, the bacterium was found in many macrophages and a few interdigitating dendritic cells at the paracortical areas. H. pylori was also found in the intracellular canaliculi of parietal cells in 21 patients, but intracytoplasmic invasion into gastric epithelial cells was not identified. When compared to the commercially available anti-H. pylori antibodies, the novel antibody showed the highest sensitivity to detect H. pylori-positive macrophages, whereas no difference was found for H. pylori in the mucous layer. The H. pylori-positive macrophages in the lamina propria correlated with chronic gastritis as well as translocation of such cells to the lymph nodes. These results suggest that H. pylori-induced gastric epithelial damage allows the bacteria to invade the lamina propria and translocate to the gastric lymph nodes, which may chronically stimulate the immune system. The bacteria captured by macrophages, whether remaining alive or not, may contribute to the induction and development of H. pylori-induced chronic gastritis.
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Nishizawa T, Suzuki H, Umezawa A, Muraoka H, Iwasaki E, Masaoka T, Kobayashi I, Hibi T. Rapid detection of point mutations conferring resistance to fluoroquinolone in gyrA of Helicobacter pylori by allele-specific PCR. J Clin Microbiol 2006; 45:303-5. [PMID: 17122023 PMCID: PMC1829027 DOI: 10.1128/jcm.01997-06] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori strains with reduced susceptibility to fluoroquinolones have a mutation at either codon 87 Asn or 91 Asp of the gyrA gene. A rapid test based on an allele-specific PCR (AS-PCR) was designed to detect the gyrA mutations. Clinical H. pylori isolates were obtained from the stomachs of 51 patients with H. pylori infections who showed treatment failure. The MICs of gatifloxacin (GAT) were determined by the agar dilution method. Identical genotyping results were obtained with AS-PCR and conventional PCR. The gyrA mutations of H. pylori causing reduced susceptibility to fluoroquinolones could be detected successfully by this method. A significant association was observed between the presence of mutations, as detected by AS-PCR, and the resistance of the strains to GAT. Moreover, genotyping by AS-PCR took less than 3 to 4 h. The AS-PCR method for the detection of gyrA mutations in H. pylori is useful for easy identification of fluoroquinolone-resistant strains of H. pylori.
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Hasegawa M, Sato Y, Kanayama A, Matsuzaki K, Muraoka H, Amano A, Saika T, Kobayashi I. Antibacterial activity of tosufloxacin against major organisms detected from patients with respiratory or otorhinological infections: comparison with the results obtained from organisms isolated about 10 years ago. J Infect Chemother 2006; 12:152-6. [PMID: 16826349 DOI: 10.1007/s10156-006-0434-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Accepted: 02/16/2006] [Indexed: 10/24/2022]
Abstract
The minimum inhibitory concentrations (MICs) of tosufloxacin and other fluoroquinolone antimicrobials for Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella (Branhamella) catarrhalis, isolated, between January 2003 and July 2004, from patients suspected of having respiratory or otorhinological infections were determined. The results were compared with those for these organisms isolated in 1994, plus some H. influenzae strains isolated in 1998. Tosufloxacin was the most potent of all the antibiotics tested for antibacterial activity against S. pneumoniae (including penicillin-intermediate S. pneumoniae and penicillin-resistant S. pneumoniae). The MIC50 and MIC90 values did not differ from those obtained for the strains isolated in 1994. Fluoroquinolones exerted the most potent antibacterial activity against M. (B.) catarrhalis; the MICs for most of the strains were < or = 0.06 microg/ml; fluoroquinolones inhibited the growth of all the strains at 0.25 microg/ml or less. Fluoroquinolones showed the most potent antibacterial activity against H. influenzae strains isolated between 2003 and 2004, and in 1994, but, for one H. influenzae strain isolated, between 2003 and 2004, the MICs of fluoroquinolones were high. Some strains of S. pneumoniae and H. influenzae were resistant to fluoroquinolones. Genetic analysis showed that all of these strains had mutations in the quinolone resistance-determining region, but there were no differences according to the years of isolation. These results indicate that tosufloxacin has potent antibacterial activity against major organisms isolated from patients with respiratory or otorhinological infections; further, the results of the present study did not differ from those obtained about 10 years ago.
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Kobayashi I, Saika T, Muraoka H, Murakami K, Fujioka T. Helicobacter pylori isolated from patients who later failed H. pylori eradication triple therapy readily develop resistance to clarithromycin. J Med Microbiol 2006; 55:737-740. [PMID: 16687592 DOI: 10.1099/jmm.0.46316-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In this study, the ease of selection of clarithromycin resistance was investigated in clarithromycin-susceptible Helicobacter pylori strains isolated from patients with H. pylori infection prior to the administration of triple-combination eradication therapy (clarithromycin plus amoxicillin plus a proton pump inhibitor). Clarithromycin-susceptible strains isolated from ten patients in whom the eradication therapy was successful and from six patients in whom the eradication therapy was unsuccessful were exposed serially to subinhibitory concentrations of clarithromycin. The number of transfers required for the MICs of the strains to increase by 8- and 32-fold were 6.6 and 7.2, respectively, in the successful eradication group, and as few as 2.4 and 1.5, respectively, in the unsuccessful eradication group. The number of transfers required for the A2142G or A2143G point mutation of the 23S rRNA gene to be detected in the strains were 5 and 8, respectively, for the strains in the successful eradication group, and 1 and 2, respectively, for the strains in the unsuccessful eradication group. These results suggest that patients in the unsuccessful eradication group were infected with strains of H. pylori that readily became resistant to clarithromycin on exposure to the drug.
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Nishizawa T, Suzuki H, Kurabayashi K, Masaoka T, Muraoka H, Mori M, Iwasaki E, Kobayashi I, Hibi T. Gatifloxacin resistance and mutations in gyra after unsuccessful Helicobacter pylori eradication in Japan. Antimicrob Agents Chemother 2006; 50:1538-40. [PMID: 16569878 PMCID: PMC1426923 DOI: 10.1128/aac.50.4.1538-1540.2006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A high resistance rate (47.9%) to gatifloxacin (GAT; 8-methoxy fluoroquinolone) in Helicobacter pylori (H. pylori) strains from 48 Japanese patients is observed after unsuccessful H. pylori eradication. A significant association between MICs for GAT equal to or above 1 microg/ml and mutations of the gyrA gene of H. pylori was demonstrated.
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Matsushima M, Suzuki T, Kurumada T, Watanabe S, Watanabe K, Kobayashi K, Deguchi R, Masui A, Takagi A, Shirai T, Muraoka H, Kobayashi I, Mine T. Tetracycline, metronidazole and amoxicillin-metronidazole combinations in proton pump inhibitor-based triple therapies are equally effective as alternative therapies against Helicobacter pylori infection. J Gastroenterol Hepatol 2006; 21:232-6. [PMID: 16460479 DOI: 10.1111/j.1440-1746.2006.04171.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND A proton pump inhibitor (PPI)-based triple therapy with clarithromycin (CAM) and amoxicillin (AMPC) is now a standard regimen for Helicobacter pylori (HP) eradication in Japan. However, the CAM-resistant rate has increased recently and alternative therapies are sorely needed. Therefore the aim of the present study was to evaluate the effectiveness and safety of the PPI-tetracycline (TC)-metronidazole (MNZ) regimen (the PTM regimen) as an alternative therapy in comparison with the PPI-AMPC-MNZ (PAM) regimen. METHODS Sixty-four HP-positive patients visiting the HP-eradication clinic in Tokai University Hospital from July 1998 to March 2003 were treated with either PTM or PAM as alternative therapies. The HP eradication was assessed by urea breath test (UBT), HP stool antigen test, or HP culture method more than 2 months after completion of the treatments. The drug resistances against CAM, AMPC, TC, and MNZ were assessed by the agar dilution method. RESULTS Fifty-six patients (26 PTM and 30 PAM) completed medication and evaluation of the eradication. The eradication rates of PTM were 82.8% (24/29) and 92.3% (24/26), while those of PAM were 74.3% (26/35) and 89.7% (26/29) by intention-to-treat and per-protocol analysis, respectively. The differences between the regimens were not statistically significant. There were no severe adverse effects observed in either of the regimens. The drug-resistance analyses showed 15 CAM- and one MNZ-resistant cases but no TC or AMPC resistance in the available 25 samples. CONCLUSION The PTM and PAM regimens were equally effective and safe as alternative HP eradication therapies. And PTM would be particularly useful in penicillin allergy cases.
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