Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
1.
Sci Rep ; 14(1): 13798, 2024 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877041

RESUMO

We assessed the short-term effects of switching from intravitreal aflibercept (IVA) to intravitreal faricimab (IVF) on ocular blood flow in patients with treatment-resistant diabetic macular edema (DME). The medical records of 15 patients with DME who had received IVA injection ≥ 3 months before were retrospectively reviewed. The best-corrected visual acuity, central macular thickness (CMT) on optical coherence tomography, and mean blur rate (MBR) of all disc areas on laser speckle flowgraphy were measured before, 1 week after, and 4 weeks after IVA and IVF, respectively. The changes in visual acuity showed no significant difference after switching from IVA to IVF (P = 0.732). The mean CMT decreased significantly during the follow-up period (both P < 0.001). MBR showed no significant difference during the follow-up period (P = 0.26). However, it decreased significantly 4 weeks after IVF (P = 0.01) compared with the baseline value, but not 4 weeks after IVA (P = 0.074). A significant association was observed between decreased MBR and decreased CMT in patients who received IVF (correlation coefficient: 0.501, P = 0.005) but not in those who received IVA (P = 0.735). Thus, IVF maintained ocular blood flow reduction, although no significant differences in visual acuity and CMT changes were observed compared to IVA.


Assuntos
Retinopatia Diabética , Injeções Intravítreas , Edema Macular , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes de Fusão , Humanos , Edema Macular/tratamento farmacológico , Edema Macular/etiologia , Masculino , Feminino , Proteínas Recombinantes de Fusão/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/uso terapêutico , Pessoa de Meia-Idade , Retinopatia Diabética/tratamento farmacológico , Idoso , Estudos Retrospectivos , Acuidade Visual/efeitos dos fármacos , Tomografia de Coerência Óptica , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/uso terapêutico , Fluxo Sanguíneo Regional/efeitos dos fármacos , Olho/irrigação sanguínea , Olho/efeitos dos fármacos
2.
Jpn J Ophthalmol ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874665

RESUMO

PURPOSE: To evaluate retinal blood flow (RBF) regulation in response to RBF stress in maturity-onset diabetes of the young type 3 (MODY3) pigs. STUDY DESIGN: Case-control study. METHODS: MODY3 pigs (diabetes mellitus [DM] group, n = 8) transfected with the human mutant hepatocyte nuclear factor-1⍺ and normal pigs of the same age (normal group, n = 8) were used as subjects. After confirming DM onset, the experiment was performed under inhalation anesthesia with isoflurane at 2 months of age before the cataract progressed. Ocular blood flow was assessed by calculating the optic papillary mean blur rate using laser speckle flowgraphy, modified for pig eye measurements. After baseline ocular blood flow measurements, flicker stimulation (12 Hz, 3 min) was applied, and ocular blood flow was measured over time. RESULTS: Blood glucose was 81.8 ± 5.1 mg/dL in the normal group and 311.4 ± 23.1 mg/dL in the DM group (mean ± standard error). The percent change in ocular blood flow at 3 min after flicker stimulation was +31.0 ± 10.9% in the normal group and -6.6 ± 6.5% in the DM group compared to the preload value, and the difference was statistically significant (Mann-Whitney test, P = 0.015). CONCLUSION: RBF response to flicker stimulation is reduced at 2 months of age in MODY3 pigs, suggesting that retinal neurovascular coupling is impaired from the early onset of DM.

3.
Curr Microbiol ; 81(2): 61, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38206417

RESUMO

In this study, population analysis (PA) of methicillin-resistant Staphylococcus aureus (MRSA), before and after long-duration daptomycin (DAP) treatment, was used to detect subpopulations with different susceptibilities to DAP and to verify the changes in the number of resistant cells. Furthermore, we aimed to characterize the bacteriology of the variants present in the non-susceptible cell subpopulation. A DAP non-susceptible (NS) MRSA phenotype (D2) that emerged from a DAP- susceptible MRSA phenotype (D1) during treatment of an open wound, was used for testing. We performed bacteriological and genetic analyses of cryptic DAP-NS MRSA variants detected by PA to study the variants present in the resistant cell subpopulation. PA results suggest that MRSA adapted to survival in the presence of DAP are selected leading to reduced susceptibility. Within the cell population growing in media containing 2.0 mg/L of DAP, three variants with different pigment production and colony size were detected. Variant 3 was an orange colony due to enhanced production of staphyloxanthin. Our results revealed that the DAP minimum inhibitory concentration (MIC) value increased two-fold (4 mg/L) in variant 3, in which pigment production was most enhanced, compared to the parental strain D2. In conclusion, our results indicate that long-duration DAP treatment can lead to the emergence and increased proportion of DAP-NS subpopulations. Furthermore, slow-growing variants that can be detected only under antimicrobial selective pressure are present among DAP-NS cells, suggesting that these variants may also contribute to the development of DAP resistance.


Assuntos
Daptomicina , Staphylococcus aureus Resistente à Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Daptomicina/farmacologia , Testes de Sensibilidade Microbiana , Fenótipo
4.
J Antimicrob Chemother ; 78(11): 2683-2690, 2023 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-37769185

RESUMO

OBJECTIVES: The aim of this study was to explore the origin of the PenA mosaic amino acid sequence in the ceftriaxone-resistant Neisseria gonorrhoeae FC428 clone. METHODS: The penA sequences of 27 Neisseria subflava pharyngeal isolates were determined by the Sanger method and penA sequences of 52 isolates from nine Neisseria species were obtained from the NCBI database. Comparative analysis of each PenA sequence was performed by multiple sequence alignment using ClustalW. In vitro resistance acquisition experiments were conducted to investigate the possibility of selection pressure by cefixime-induced amino acid substitution mutations in PenA. RESULTS: All N. subflava strains, including two with low susceptibility to expanded-spectrum cephalosporins (ESCs), possessed the majority of the PenA FC428 sequence. Furthermore, a number of strains, but not all, of closely related species of N. subflava showed similar results. PenA FC428 sequences were also found in some strains of distantly related species. No new mutations in the penA sequence were observed in colonies with increased MIC in in vitro resistance acquisition experiments. CONCLUSIONS: This study provides strong evidence that the FC428 PenA mosaic sequence originated from N. subflava and related species among oral commensal Neisseria species. The results of in vitro resistance acquisition experiments also suggested that one of the PenA FC428-like sequence gene polymorphisms resulted in the expression of ESC resistance. Furthermore, many of the PenA FC428 mosaic sequences were thought to be involved in the so-called epistasis effect that regulates the expression of resistance, without directly contributing to the resistance level itself.


Assuntos
Ceftriaxona , Gonorreia , Humanos , Ceftriaxona/farmacologia , Neisseria gonorrhoeae , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Testes de Sensibilidade Microbiana , Epigênese Genética
5.
Exp Eye Res ; 233: 109548, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37348671

RESUMO

We examined the effects of nobiletin, a polymethoxyflavonoid, on the retinal microvascular diameter to determine if they depend on the endothelium and/or smooth muscle to reveal the signaling mechanisms involved in this vasomotor activity. Porcine retinal arterioles were isolated, cannulated, and pressurized without flow in vitro. Video microscopic techniques recorded diametric responses to nobiletin. The retinal arterioles dilated in a nobiletin concentration-dependent (100 pM-10 µM) manner and decreased by 50% after endothelial removal. The nitric oxide (NO) synthase inhibitor, Nω-nitro-L-arginine methyl ester (L-NAME), reduced nobiletin-induced vasodilation comparable to denudation. Blockade of soluble guanylyl cyclase by 1H-[1,2,4] oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ) produced a similar inhibitory effect as that by L-NAME. Nobiletin-induced vasodilation was also inhibited by the nonselective potassium channel inhibitor, tetraethylammonium (TEA), and the voltage-gated K (Kv) inhibitor, 4-aminopyridine. Co-administration of L-NAME and TEA almost eliminated nobiletin-induced vasodilation. Nobiletin elicits both endothelium-dependent and -independent dilation of retinal arterioles mediated by NO release and Kv channel activation, respectively.


Assuntos
Óxido Nítrico , Canais de Potássio , Suínos , Animais , Óxido Nítrico/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Arteríolas/fisiologia , Canais de Potássio/farmacologia , Canais de Potássio/fisiologia , Dilatação , Vasodilatação/fisiologia , Inibidores Enzimáticos/farmacologia , Endotélio Vascular/metabolismo
6.
Chem Asian J ; 18(8): e202300029, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-36808824

RESUMO

We have proposed a new method for the exploration of organic functional molecules, using an exhaustive molecular generator combined without combinatorial explosion and electronic state predicted by machine learning and adapted for developing n-type organic semiconductor molecules for field-effect transistors. Our method first enumerates skeletal structures as much as possible and next generates fused ring structures using substitution operations for atomic nodes and bond edges. We have succeeded in generating more than 4.8 million molecules. We calculated the electron affinity (EA) of about 51 thousand molecules with DFT calculation and trained the graph neural networks to estimate EA values of generated molecules. Finally, we obtained the 727 thousand molecules as candidates that satisfy EA values over 3 eV. The number of these possible candidate molecules is far beyond what we have been able to propose based on our knowledge and experience in synthetic chemistry, indicating a wide diversity of organic molecules.

7.
Exp Eye Res ; 227: 109379, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36608813

RESUMO

Diabetic retinopathy (DR) is a leading cause of blindness in the working population. Because novel therapeutic intervention require testing, there is an urgent need for reliable animal models that faithfully replicate DR. Pig eyes have many similarities to human eyes anatomically and physiologically. Thus, attempts have been made to establish porcine models of DR by surgical, pharmaceutical or genetical induction of insulin deficiency, and dietary intervention. A previous study reported a transgenic pig model of maturity onset diabetes of the young type 3 (MODY3) developed signs of severe DR such as hemorrhage and proliferative tissue at the surface of the retina. However, the course of development of DR has not been studied in detail in this model. The purpose of this study was to investigate the early phase of DR in a MODY3. MODY3 and wild-type (WT) pigs underwent fundus photography and fluorescein angiogram (FA) before they developed cataracts. Animals were euthanized at age 1, 4, 7, and 10 months. Whole-mount retina and 10-µm thick paraffinized sections were stained with isolectin B4, and vessel density was determined by MATLAB software. At 4 and 7 months, retinal arterioles were immediately cannulated, and vasomotor action was measured by incubation with bradykinin and sodium nitroprusside. In the MODY3 pigs, fasting blood sugar levels gradually increased up to 500 mg/dL. Vascular tortuosity and yellowish spindle-shaped lesions were confirmed in MODY3 pigs at the age of 7 months; however, no microaneurysms were detected on FA. Compared with age-matched WT pigs, MODY3 pigs showed a significant decrease in blood vessel density in the intermediate and deep vascular plexus at 4 and 7 months of age and a slight decrease in capillary density in the superficial vascular plexus at 7 months of age. In MODY3 pigs, electron microscopy revealed thickening of the capillary basement membrane and leukostasis in the major blood vessels at 10 months of age. Bradykinin-induced dilation of retinal arterioles was diminished in MODY3 pigs as early as 7 months of age. Within 1 year after birth, MODY3 pigs show all typical early vascular lesions of diabetes except for microaneurysm formation. This pilot study suggests that the MODY3 pigs may serve as a suitable DR model to test effects of newly developed compounds on DR.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Humanos , Suínos , Animais , Lactente , Retinopatia Diabética/patologia , Projetos Piloto , Bradicinina/farmacologia , Retina/patologia , Vasos Retinianos/patologia , Angiofluoresceinografia , Tomografia de Coerência Óptica , Diabetes Mellitus/patologia
8.
J Antimicrob Chemother ; 77(2): 364-373, 2022 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-34747462

RESUMO

BACKGROUND: The ceftriaxone-resistant Neisseria gonorrhoeae FC428 clone was first discovered in Japan in 2015. OBJECTIVES: We investigated the possibility of horizontal gene transfer from Neisseria subflava harbouring the mosaic-like PBP-2 in the emergence of the FC428 clone. We also analysed whether there were fitness costs associated with the sustained international dissemination of the clone. METHODS: Sequencing of the penA gene in ceftriaxone-resistant N. subflava strains was performed. For transformation experiments between donor N. subflava and ciprofloxacin-resistant wild-type penA N. gonorrhoeae recipient, the full-length PCR amplification product of the penA gene, including DUS regions, was used as the donor DNA. Biological fitness of the transformants was measured by growth competition assays. The impact of QRDR and mtrR mutations, which have been reported as compensatory mutations, on fitness was also assessed. RESULTS: The penA mosaic allele of the FC428 clone showed 100%, 91.8%, and 89.8% homology, respectively, with penA genes of three ceftriaxone-resistant N. subflava strains, No. 30, No. 9 and No. 14. Results were consistent with homologous recombination with the donated penA mosaic allele. In co-cultures with the parent strain, transformants showed comparable growth indicating that a gyrA mutation compensates for the fitness cost of mosaic penA alleles. CONCLUSIONS: Our findings support the hypothesis that the FC428 clone was generated by transformation of the mosaic penA allele from oropharyngeal N. subflava to N. gonorrhoeae. Furthermore, it suggests that mutations in the gyrA QRDR region compensate for fitness costs and contribute to the continued transmission of the FC428 clone.


Assuntos
Farmacorresistência Bacteriana/genética , Transferência Genética Horizontal , Neisseria gonorrhoeae , Neisseria/genética , Antibacterianos/farmacologia , Ceftriaxona/farmacologia , Células Clonais , Gonorreia/tratamento farmacológico , Gonorreia/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/genética
9.
J Glob Antimicrob Resist ; 26: 45-51, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34029771

RESUMO

OBJECTIVES: The objective of this study was to investigate the molecular characteristics and antimicrobial susceptibility of penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates collected in Fukuoka, Japan, from 1996-2018. METHODS: Antimicrobial susceptibility to seven antibiotics was determined by the agar dilution method. Molecular characteristics were determined by Sanger sequencing of the blaTEM allele, plasmid typing and N. gonorrhoeae multiantigen sequence typing (NG-MAST). Furthermore, full sequences of the penA gene, encoding penicillin-binding protein 2 (PBP2), of PPNG isolates with reduced susceptibility to cefixime were analysed. RESULTS: Among 50 PPNG isolates, 17 and 33 were collected during 1996-2006 and 2007-2018, respectively. In 1996-2006, blaTEM-1 in African plasmid was most frequent (64.7%), followed by blaTEM-1 in Asian plasmid (29.4%) and blaTEM-135 in Toronto/Rio plasmid (5.9%). In 2007-2018, blaTEM-135 in Toronto/Rio plasmid was predominant (54.5%), followed by blaTEM-1 in African plasmid (36.4%) and blaTEM-135 in Asian plasmid (6.1%). Among isolates with the blaTEM-135-carrying Toronto/Rio plasmid in 2007-2018, a novel genogroup G15576 was predominant (66.7%). Isolates with the TEM-135 ß-lactamase were more resistant to ciprofloxacin but were more susceptible to ceftriaxone and tetracycline than isolates with TEM-1. Seven PPNG isolates less susceptible to cefixime possessed the plasmidic blaTEM-1 allele and had mosaic or non-mosaic alterations within PBP2. CONCLUSION: The proportion of PPNG with the blaTEM135-carrying Toronto/Rio plasmid increased during the last 12 years. The increase in PPNG carrying the blaTEM-135 allele is of particular concern as it is considered a possible direct precursor of an extended-spectrum ß-lactamase (ESBL).


Assuntos
Gonorreia , Neisseria gonorrhoeae , Antibacterianos/farmacologia , Humanos , Japão , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae/genética , Penicilinase/genética
10.
J Infect Chemother ; 25(8): 594-604, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30954447

RESUMO

The susceptibilities of clinical isolates to fluoroquinolones and other antimicrobial agents were surveyed to obtain an accurate understanding of trends in incidence and antimicrobial resistance. The samples were collected from across Japan, biennially or triennially, between 1994 and 2016 and a defined level of resistance to fluoroquinolone was determined. Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae exhibited stable and high rates of susceptibility to fluoroquinolones over the period examined. For methicillin-resistant Staphylococcus aureus the rate of resistance to levofloxacin and ciprofloxacin was 81.3-93.5% and 83.2-94.2%, respectively, which was markedly higher than that of methicillin-susceptible S. aureus, while sitafloxacin-resistant methicillin-susceptible and methicillin-resistant S. aureus were isolated at 0.3-0.7% and 16.9-36.5%, respectively. The rate of levofloxacin or ciprofloxacin-resistant Escherichia coli increased from around 2-3% between 1994 and 1998 to around 35% in 2016, but the rate of fluoroquinolone-susceptible Klebsiella pneumoniae stayed high at over 94.6% during the study period. Although no fluoroquinolone-resistance in clinical isolates of Salmonella spp. was detected from 1994 to 2002, the resistance rate increased slightly after 2004 and reached to 1.9%-4.7% in 2016. The rate of fluoroquinolone-susceptible Pseudomonas aeruginosa isolated from urinary tract and respiratory tract infections improved during the period examined from 41.8-67.0% to 91.2-94.2%, and from 78.9-88.5% to 90.1-94.6%, respectively. Against Acinetobacter spp., the susceptibility rate of fluoroquinolones was almost constant at around 90%, but one multidrug-resistant isolate was detected in 2013. Overall, the susceptibility to fluoroquinolones was maintained over 20 years against tested bacteria except for MRSA and E. coli.


Assuntos
Anti-Infecciosos/uso terapêutico , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Fluoroquinolonas/uso terapêutico , Humanos , Japão , Estudos Longitudinais , Testes de Sensibilidade Microbiana/métodos
11.
J Glob Antimicrob Resist ; 17: 3-7, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30448519

RESUMO

OBJECTIVES: Antimicrobial resistance and molecular characteristics of Neisseria gonorrhoeae isolates obtained from 1996-2005 (n=200) and 2008-2016 (n=200) in Fukuoka, Japan, were examined. METHODS: MICs were determined by agar dilution. Sequence types (STs) were examined using N. gonorrhoeae multiantigen sequence typing (NG-MAST). Sequencing of major extended-spectrum cephalosporin (ESC) resistance determinants (penA, mtrR and ponA) was performed. RESULTS: Increases in the proportion of gonococci with decreased susceptibility or resistance to cefixime (from 18.0% in 1996-2005 to 46.0% in 2008-2016) and ceftriaxone (from 2.5% to 4.0%) were observed. Gonococcal isolates also showed increased resistance to ciprofloxacin and azithromycin. The four most prevalent NG-MAST STs with a multidrug-resistant phenotype were ST2958 (n=18), ST1407 (n=14), ST6798 (n=12) and ST4015 (n=10). The number of isolates belonging to these four STs rose between the first and second period. Among the 54 isolates belonging to the four major STs, 42 (77.8%) contained a penA mosaic allele and 12 (22.2%) contained a penA non-mosaic allele. The sequence pattern types in the 42 isolates with a penA mosaic allele included type X (64.3%), type XXXIV (33.3%) and a novel pattern type (2.4%). In contrast, all 12 isolates with the penA non-mosaic allele included the sequence pattern type V. CONCLUSION: Neisseria gonorrhoeae isolates with decreased susceptibility or resistance to ESC have increased over the years. Four major STs with a multidrug-resistant phenotype were identified. These isolates contained a penA mosaic allele or a non-mosaic allele.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Gonorreia/microbiologia , Neisseria gonorrhoeae/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cefixima/farmacologia , Ceftriaxona/farmacologia , Humanos , Japão , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/isolamento & purificação
12.
Beilstein J Org Chem ; 13: 1816-1822, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28904625

RESUMO

Thiazolium carbene-catalyzed reactions of 1,2-diketones and 1,2,3-triketones with enones and ynones have been investigated. The diketones gave α,ß-double acylation products via unique Breslow intermediates isolable as acid salts, whereas the triketones formed stable adducts with the NHC instead of the coupling products.

13.
Jpn J Antibiot ; 69(1): 1-25, 2016 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-27290827

RESUMO

Antimicrobial susceptibility testing has been conducted continuously as postmarketing surveillance of levofloxacin (LVFX) since 1994. The present survey was undertaken to investigate in vitro susceptibilities of bacteria to 33 selected antibacterial agents, focusing on fluoroquinolones (FQs), using 11,762 clinical isolates for 19 species collected from 69 centers during 2013 in Japan. The common respiratory pathogens Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae continue to show a high susceptibility to FQs, while the percentage of macrolide-resistant S. pneumoniae was markedly increased to around 80%. With H. influenzae, the percentage of ß-lactamase-negative ampicillin-resistant isolates had been increasing continuously from 2002, but no increase was observed from 2010 to 2013 (25.8% in 2002, 40.0% in 2004, 50.1% in 2007, 57.9% in 2010, and 57.1% in 2013). Most strains of Enterobacteriaceae showed a high susceptibility to FQs, but the isolation frequency of levofloxacin-resistant Escherichia coli including intermediate resistance was 34.4%, showing a continuous increase. Another Enterobacteriaceae member, Klebsiella pneumoniae, showed low resistance to FQs in contrast with E. coli. Regarding methicillin-resistant Staphylococcus aureus (MRSA), the percentage of FQ-susceptible isolates was low at 15.8-18.0%, with the exception of 55.3% susceptibility to sitafloxacin. On the other hand, methicillin-susceptible S. aureus (MSSA) isolates showed high susceptibility to FQs, at 87.0-99.3%. With Enterococcusfaecium, the percentage of FQ-susceptible isolates was 6.8-24.7%. The percentage of FQ-susceptible Pseudomonas aeruginosa was 83.4-89.3% among isolates derived from urinary tract infections (UTIs), while that from respiratory tract infections (RTIs) was 88.1-93.7%. This was summarized as susceptibility to FQs over 80% in both infections. A continuous decrease in FQ-resistant P. aeruginosa was noted, especially among isolates from UTIs. Regarding multidrug-resistant P aeruginosa, the percentage has been decreasing continuously since 2007 and was 1.6% from UTIs and 0% from RTI in this survey. Acinetobacter spp. showed high susceptibility to FQs. The percentage of imipenem-resistant Acinetobacter spp. was 2.7% (14 isolates) and that of multidrug-resistant was 0.2% (1 isolate). In Neisseria gonorrhoeae, ceftriaxone (CTRX) had been showing 100% susceptibility until 2007, but CTRX-resistant strains have been detected in both 2010 and this survey. In conclusion, the resistance of methicillin-resistant staphylococci, E. faecium, N. gonorrhoeae, and E. coli to the FQs, which have been used clinically for over 20 years, was shown to be 30% or more (31.7-87.1%) in the present surveillance regarding susceptibility. These results were similar to those from previous surveillance, and no species that started to show significant resistance to FQs were identified in the present surveillance. Regarding other bacterial species, susceptibility to ciprofloxacin less than 80% was observed in some, while susceptibility to other FQs was maintained at a high level, at 80% or more.


Assuntos
Antibacterianos/farmacologia , Levofloxacino/farmacologia , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana
14.
Chem Commun (Camb) ; 50(82): 12285-8, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25178473

RESUMO

Thiazolium carbene-catalyzed reaction of aromatic 1,2-diketones with enones in aprotic solvents gave double acylation products in good yields, whereas hydroacylation products formed by Stetter reaction were not detected at all. These results suggested the generation of aroyloxyenamine species from the 1,2-diketones instead of hydroxyenamines (Breslow intermediates).

16.
Microbes Environ ; 28(1): 81-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23138151

RESUMO

Antimicrobial growth promoters (AGPs) have been banned and phased out because their use has been linked to the emergence and spread of antibiotic-resistant pathogens; however, the ban has had a marked impact on livestock production, and feed additive alternatives to AGPs are required. We focused on green tea leaves as potential alternatives to AGPs because they contain significant amounts of polyphenol catechins, which have antivirus and antimicrobial effects. We examined cross-resistance between epigallocatechin gallate (EGCG), which is the most abundant catechin of green tea leaves, and commercially available antimicrobials in clinically problematic antimicrobial-resistant bacteria, and whether bacteria have the ability to acquire resistance by consecutive passage in sub-inhibitory concentrations of EGCG. EGCG did not display any cross-resistance with reference antimicrobials and the bacteria did not acquire EGCG resistance. Further, we examined the growth-promoting effects of dried green tea leaves on the breeding of a new Japanese breed, Tokyo-X pigs. While the mortality rates of the green tea leaf (GTL) and AGP groups were both 11.1% (one in nine piglets), the mortality rate was 50% for the control group with an additive-free diet (four in eight piglets). The rate of body weight increase in both the GTL and AGP groups was approximately the same. The growth-promoting effects of green tea leaves and AGPs were similar, and there was no possibility that the antimicrobial properties of catechins caused the same problem as AGPs. Thus, it can be concluded that green tea leaves are a safe feed additive alternative to AGPs.


Assuntos
Antibacterianos/farmacologia , Camellia sinensis/química , Catequina/farmacologia , Farmacorresistência Bacteriana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/química , Catequina/análogos & derivados , Catequina/química , Aditivos Alimentares/química , Humanos , Testes de Sensibilidade Microbiana , Folhas de Planta/química , Suínos
17.
Jpn J Antibiot ; 65(3): 181-206, 2012 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-23173294

RESUMO

Postmarketing surveillance of levofloxacin (LVFX) has been conducted continuously since 1992. The present survey was performed to investigate in vitro susceptibility of recent clinical isolates in Japan to 30 selected antibacterial agents, focusing on fluoroquinolones (FQs). The common respiratory pathogens Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae continue to show a high susceptibility to FQs. In contrast, widely-prevailing resistance to macrolides was markedly noted among S pneumoniae and S. pyogenes. Regarding H. influenzae, the prevalence of beta-lactamase-negative ampicillin-resistant isolates has been increasing year by year (25.8% in 2002, 40.0% in 2004, 50.1% in 2007, and 57.9% in 2010). Enterobacteriaceae showed high susceptibility to FQs, however, prevalence of LVFX-resistant Escherichia coli, including intermediate resistance, was 29.3%, showing an increase over time. Nevertheless, the increase in the prevalence of LVFX-resistant E. coli isolates has slowed since 2007 (8.2% in 2000, 11.8% in 2002, 18.8% in 2004, 26.2% in 2007, and 29.3% in 2010), suggesting the influence of LVFX 500 mg tablets since its approval in 2009. Another Enterobacteriaceae member, Klebsiella pneumoniae, showed low resistance to FQs, in contrast with E. coli. In methicillin-resistant Staphylococcus aureus (MRSA), the percentage of FQ-susceptible isolates was low, at 51.6% for susceptibility to sitafloxacin, and at only around 10% for susceptibility to other FQs. However, methicillin-susceptible S. aureus (MSSA) isolates were highly susceptible to FQs, with the percentage ranging from 88.5% to 99.1%. The prevalence of FQs-resistant isolates in methicillin-resistant coagulase-negative staphylococci was higher than that in methicillin-susceptible coagulase-negative staphylococci, although it was lower than the prevalence of FQ-resistance in MRSA. The prevalence of FQs-resistant Pseudomonas aeruginosa isolates derived from urinary tract infections (UTIs) was 15.4-21.3%, higher than the prevalence of 6.1-12.3% in P. aeruginosa isolates from respiratory tract infections (RTIs). While this trend was consistent with the results of previous surveillance, gradual decreases were noted in the prevalence of FQ-resistant P. aeruginosa isolates derived from UTIs. The prevalence of multidrug-resistant P. aeruginosa was 2.3% among isolates derived from UTIs and 0.3% among isolates from RTIs, a decrease from the results of 2007. Acinetobacter spp. showed high susceptibility to FQs. Imipenem-resistant Acinetobacter baumannii, which is currently an emerging issue, was detected at a prevalence of 2.4% (13 isolates). Neisseria gonorrhoeae showed a high resistance of 81.3-82.5%, to FQs. Ceftriaxone (CTRX) continued to show 100% susceptibility until 2007, but the present survey revealed the advent of resistance to CTRX in some clinical isolates. The result of the present survey indicated that although methicillin-resistant staphylococci, Enterococcus faecium, P. aeruginosa from UTIs, N. gonorrhoeae, and E. coli showed resistance of about 20% or more (19.5-89.2%) against the FQs which have been used clinically for over 17 years, the trends observed were similar to the results of previous surveillance. While FQ resistance has been prevailing in E. coli, E. coli still shows more than 70% susceptibility to FQs. The other bacterial species maintained high susceptibility rates of greater than 80%, against FQs.


Assuntos
Antibacterianos/farmacologia , Levofloxacino , Ofloxacino/farmacologia , Farmacorresistência Bacteriana , Enterobacteriaceae/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana
18.
Med Mycol ; 50(4): 353-60, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21954955

RESUMO

Candidemia remains a major cause of morbidity and mortality, especially in immunocompromised patients. A strategy of reducing virulence and virulence factors of Candida spp. is an attractive approach for the treatment of serious infections caused by these yeasts. Recently, farnesol has been reported to be a quorum-sensing autoinducer, as well as a virulence factor of C. albicans. In the present study, we examined the effects of pravastatin, a 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor on the in vitro production of farnesol. In addition, the synergistic effects of pravastatin with fluconazole (FLC) were examined in a mouse model of systemic infections. In vitro experiments demonstrated that pravastatin had synergistic activity with FLC as judged by fractional inhibitory concentration index (FICI) and suppression of farnesol production at sub-minimum inhibitory concentrations. Furthermore, significant improvement of survival in systemic infection models was shown with pravastatin supplementation. The survival benefits of pravastatin were correlated with reductions of fungal burden. These data suggest the potential of pravastatin as a supportive therapy against C. albicans infections. Synergistic antifungal activity and suppression of HMG-CoA reductase-associated Candida virulence factors, including farnesol, may explain, at least in part, the in vivo efficacy of pravastatin.


Assuntos
Antifúngicos/administração & dosagem , Candida albicans/efeitos dos fármacos , Candida albicans/metabolismo , Candidíase/mortalidade , Farneseno Álcool/antagonistas & inibidores , Farneseno Álcool/metabolismo , Pravastatina/administração & dosagem , Animais , Antifúngicos/farmacologia , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos C3H , Pravastatina/farmacologia , Análise de Sobrevida , Fatores de Virulência/antagonistas & inibidores , Fatores de Virulência/metabolismo
20.
J Org Chem ; 76(12): 5018-25, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-21568347

RESUMO

5,12-Bis(methylthio)tetracene (2) and 5,11-bis(methylthio)tetracene (3) were synthesized. DFT calculations indicate that the HOMO and LUMO energy levels of 2 and 3 are lowered by 0.13-0.24 eV and their HOMO-LUMO energy gaps are reduced by 0.1 eV relative to those of tetracene. X-ray crystallographic data revealed that 2 is arranged as a result of a 1-D slipped-cofacial π-stacking with S-S and S-π interactions, similar to the packing arrangement of 6,13-bis(methylthio)pentacene (1), whereas 3 exhibits a herringbone packing arrangement without S-S interactions. The OFET devices fabricated using spin-coated films of soluble 1 and 2, with a bottom-contact device configuration, exhibited hole mobilities as high as 1.3 × 10(-2) and 4.0 × 10(-2) cm(2) V(-1) s(-1) with current on/off ratios of over 10(5) and 10(4), respectively.


Assuntos
Naftacenos/síntese química , Compostos de Sulfidrila/química , Cristalografia por Raios X , Metilação , Microscopia de Força Atômica , Modelos Moleculares , Conformação Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA