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The in vitro microbicidal activity of benzoyl peroxide against Cutibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Malassezia furfur, Malassezia restricta, and Malassezia globosa was investigated. These strains were incubated for 1 h in the presence of 0.25, 0.5, 1, or 2 mmol/L benzoyl peroxide in phosphate buffered saline supplemented with 0.1% glycerol and 2% Tween 80. After exposure to benzoyl peroxide, counts of viable Gram‐positive bacteria and fungi were markedly decreased, whereas counts of Gram‐negative bacteria were unchanged. Transmission electron microscopy images showed a decrease in electron density and the destruction of C. acnes and M. restricta cell walls after exposure to 2 mmol/L benzoyl peroxide. In conclusion, this study showed that benzoyl peroxide has a potent and rapid microbicidal activity against Gram‐positive bacteria and fungi that are associated with various cutaneous diseases. This suggests that the direct destruction of bacterial cell walls by benzoyl peroxide is an essential mechanism of its rapid and potent microbicidal activity against microorganisms. [ABSTRACT FROM AUTHOR]

To evaluate how magnetic properties of magnetic materials are influenced by power semiconductor properties in an inverter circuit, we propose and test a new numerical calculation method. This method combines an electrical circuit analysis for current–voltage properties of power semiconductors with a magnetic analysis based on a magnetic hysteresis model. Previous measurements on an inverter show that magnetic properties, such as B–H curves (B is the magnetic flux density and H is the magnetic field intensity) and iron losses, are affected by ON-voltages of power semiconductors. Those measurements motivate this paper. The magnetic hysteresis model used here is a novel approach that is based on physical thermodynamics theory and can capture the essence of physical magnetic phenomena. Calculations with the proposed method show that measured minor loops in B–H curves are well represented and calculated voltage waveforms properly capture ON-voltage effects. [ABSTRACT FROM AUTHOR]

The in vitro antifungal activities of micafungin in comparison to caspofungin, fluconazole, itraconazole, voriconazole, and amphotericin B were evaluated against 93 Candida and 23 Aspergillus isolates recovered from pediatric patients with fungal infections. MICs were determined by the CLSI M27-A2 and M38-A for Candida and Aspergillus species, respectively. Micafungin showed potent activity against Candida albicans, Candida tropicalis, and Candida glabrata with a MIC range of = 0.002 to 0.015µg/ml. In contrast, micafungin demonstrated higher MIC levels against Candida parapsilosis with a MIC range of 0.12 to 2 µg/ml. Micafungin showed potent antifungal activity against Aspergillus species tested with a MIC range of 0.004 to 0.015 µg/ml. Overall, micafungin had excellent in vitro antifungal activities against Candida and Aspergillus species recovered from pediatric patients with fungal infections. [ABSTRACT FROM AUTHOR]

Background: Metallo-β-lactamase is one of the feared resistance mechanisms inPseudomonas aeruginosa. Methods: β-Lactamase activity was determined using crude enzymes. Cloned plasmids were transformed in P. aeruginosa KG2505, PAO1 derivative without an AmpC β-lactamase and a MexAB-OprM efflux pump. Results:P. aeruginosa No. 20232 was highly resistant to imipenem (minimum inhibitory concentration >512 μg/ml). It possessed IMP-10 and the activity was 1.89 ± 0.42 μmol/min/mg of protein, which was 5–8 times higher than other tested isolates. The blaIMP-10 promoter was strong (–35 region, TTGACA; –10 region, TAAACT); on the other hand, blaIMP of other isolates had a hybrid promoter. Transformants with plasmid encoding blaIMP-10 with a strong promoter had higher enzymatic activity and were less susceptible to imipenem than those encoding blaIMP-10 with a hybrid promoter. Conclusions: The high metallo-β-lactamase activity caused by a strong promoter was a major determinant for high-level imipenem resistance of P. aeruginosa No. 20232. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We performed a scanning and transmission electron microscopic study on the efficacy of micafungin (MCFG) to understand what kind of damage MCFG causes to Aspergillus and to confirm its previously reported in vitro killing activity against Aspergillus in a mouse model of pulmonary aspergillosis. Aspergillus hyphae in MCFG-treated mice displayed hyphal burst, evidenced as either flattened or atrophied appearance and leakage of cellular contents after collapse of the cell wall. Thus, MCFG can induce the destruction of Aspergillus hyphae at the focus of infection. The results of the present study indicate that MCFG improves pulmonary aspergillosis due to lethal damage to Aspergillus hyphae. This action can effectively reduce the invasive ability of Aspergillus even though MCFG does not sterilize the fungal burden. [ABSTRACT FROM AUTHOR]

Proposes a benchmark problem for evaluating the applicability of computer codes to three-dimensional (3D) nonlinear eddy current analysis of thin film magnetic recording write head. Definition of benchmark problem; Methods of analysis and measurement; Results and discussion; Conclusion.

A weakly acidic polysaccharide was purified from the extracellular zoogloeal matrix produced by Zoogloeal ramigera 115. The purified polysaccharide was homogeneous as judged by sedimentation analysis, and the average molecular weight was estimated to be about 105 by gel permeation chromatography of the fully methylated preparation. The polysaccharide was composed of D-glucose, D-galactose and pyruvic acid in an approximate molar ratio of 11:3:1.5. On the basis of methylation, periodate oxidation. Smith degradation and partial hydrolysis, the following highly branched structure was deduced for the polysaccharide; a long chain mainly consisting of β1→4-linked glucose residues branching at the C-3 or C-6 position of galactose residues which are present in β1→4 or β1→3 linkages as the minor component of the long chain; pyruvic acid residues, the sole acidic component, are linked to the non reducing end and/or 1,3-linked glucose residues through 4,6-ketal linkages. The purified polysaccharide was not readily soluble in water and had a high affinity for several metallic ions (e.g. 0.25 μmol Fe3+/mg, and 0.17 μmol Fe2+ mg). Upon addition of metallic ions (1 mM) to a gelatinous aqueous solution of the polysaccharide (K+ form, 0.125%), more than 80% of it immediately coprecipitated out with them. [ABSTRACT FROM AUTHOR]

Brief exposure to 6-azauridine stimulates the production of carbamoyl phosphate for de novo pyrimidine biosynthesis in vitro in slices of haematopoietic spleen from anaemic mice (preceding paper). In studies of the underlying mechanism for this response we turned our attention to changes in the level of substrates and effectors for carbamoyl-phosphate synthetase II. Intermediates of the orotic acid pathway and 6-azauridine had little effect on the synthetase activity in vivo. 6-Azauridine 5′-monophosphate (6-AzaUMP) stimulated synthetase II, possibly in an allosteric manner. However, in view of the potency as an activator and the tissue levels, 6-azaUMP may be only partially responsible for the stimulation. Adenine nucleotide levels in the tissue showed only minor changes after brief exposure (15 min) to 6-azauridine. The level of UTP and UDP, potent inhibitors for synthetase II, showed no significant change. The level of 5-phosphoribosyl l-pyrophosphate (PPRibP), a potent positive effector for the synthetase II, showed a more than 1.5-fold increase after 15 min. The relative importance of these factors was evaluated by assay of the synthetase, partially purified from mouse spleen, under simulated conditions in vitro. The results indicated that the enhanced level of PPRibP played a major rote in increasing the production of carbamoyl phosphate. In Ehrlich ascites cells in vitro, where 6-azauridine did not increase carbamoyl phosphate production. the basal PPRibP level was high (range over 0.1 mM) and the changes in the level, brought about by the analogue, were relatively small. [ABSTRACT FROM AUTHOR]

The Centers for Disease Control and Prevention (CDC) now recommend combination therapy with ceftriaxone 250 mg plus azithromycin (AZM) 1 g as a first-line regimen for gonorrhea because the increase of Neisseria gonorrhoeae resistant to multiple antimicrobial agents. However, reports on the in vitro activity of antimicrobial combinations against clinical isolates of N. gonorrhoeae are very rare. In the present study, a checkerboard method was utilized to examine the in vitro activity of ceftriaxone (CTRX), cefodizime (CDZM), spectinomycin (SPCM), or gentamicin (GM) in combination with AZM against 25 clinical isolates of N. gonorrhoeae. The SPCM + AZM combination demonstrated the lowest mean fractional inhibitory concentration index (FICI) of 0.69, followed by the CDZM + AZM combination (mean FICI, 0.75), the CTRX + AZM combination (mean FICI, 0.81), and the GM + AZM combination (mean FICI, 0.83). Additivity/indifference effect was detected for the SPCM + AZM combination, the CDZM + AZM combination, the CTRX + AZM combination, and the GM + AZM combination, against 96 %, 72 %, 92 %, and 100 % of the isolates, respectively. There was no antagonism for any of the antimicrobial combinations against the 25 N. gonorrhoeae isolates. These results suggest that the antimicrobial combinations may be worthy of clinical evaluation as an alternative regimen for gonococcal infections caused by antimicrobial-resistant strains. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In order to detect and track the small magnet embedded in the vicinity of a target tumor during surgical operation, a magnetic navigation system based on the three-dimensional measurement with micro-fluxgate magnetic sensors was developed. In this paper, we present an image overlay method for superimposing the magnet marker, which is localized by the magnetic navigation system, on the 2D endoscopic view. To evaluate the performance of the proposed system and its applicability in clinical use, we set up an in vivo experiment, in which the surgeons used the system to perform a thoracoscopic surgery on a pig. As a result, the surgeons could operate the partial resection of the target area, which corresponded to the tumor lesions, of the pig lung easily and safely under the guidance of the magnetic navigation system. [Copyright &y& Elsevier]

There is accumulating evidence that most β-lactam antibiotics (i.e., cephalosporins and penicillins) have some degree of convulsive activity, both in laboratory animals as well as in clinical settings. The proposed mechanism is suppression of inhibitory postsynaptic responses, mainly mediated by γ-amino butyric acid (GABA)A-receptors (GABAA-R). However, comprehensive studies on the convulsive activities of various β-lactam antibiotics in vivo and in vitro have not been performed. We have therefore examined the convulsive activities of seven different cephalosporins using both in vivo and in vitro models: intracerebroventricular (ICV) administration in mouse; [3H]muscimol binding assay (BA) in mouse brain synaptosome; and inhibition of recombinant mouse α1β2γ2s GABAA-Rs in Xenopus oocyte (GR). The rank orders of convulsive activities in mouse (cefazolin>cefoselis>cefotiam>cefpirome>cefepime>ceftazidime>cefozopran) correlated with those of inhibitory potencies on [3H]muscimol binding and GABA-induced currents of GABAA-R in vitro, with correlation coefficients of ICV:GR, ICV:BA and BA:GR of 0.882, 0.821 and 0.832, respectively. In contrast, none of the antibiotics had affinities for N-methyl-d-aspartate (NMDA) receptors nor facilitatory actions on NMDA receptor-mediated current in oocytes. These results clearly demonstrate that the mechanism of cephalosporin-induced convulsions is mediated predominantly through the inhibition of GABAA-R function and not through NMDA receptor modulation. [Copyright &y& Elsevier]

In order to detect and track the small magnet embedded in the vicinity of a target during surgical operation, a magnetic navigation system based on the three-dimensional measurement with micro-fluxgate magnetic sensors was developed. The aim of this study was to evaluate the target registration error in the magnetic navigation system. First of all, 196 grid points around the magnetic sensors were selected as the sample measurement points for accuracy evaluation and the 2×2×10 mm-sized small magnet was placed precisely at each sample point, then the three-dimensional position of the target was measured using the magnetic navigation system. As a result, the measurement accuracy of the current prototype system was found to be about 10 mm or less. [Copyright &y& Elsevier]

The Centers for Disease Control and Prevention (CDC) now recommend combination therapy with ceftriaxone 250 mg plus azithromycin (AZM) 1 g as a first-line regimen for gonorrhea because the increase of Neisseria gonorrhoeae resistant to multiple antimicrobial agents. However, reports on the in vitro activity of antimicrobial combinations against clinical isolates of N. gonorrhoeae are very rare. In the present study, a checkerboard method was utilized to examine the in vitro activity of ceftriaxone (CTRX), cefodizime (CDZM), spectinomycin (SPCM), or gentamicin (GM) in combination with AZM against 25 clinical isolates of N. gonorrhoeae. The SPCM + AZM combination demonstrated the lowest mean fractional inhibitory concentration index (FICI) of 0.69, followed by the CDZM + AZM combination (mean FICI, 0.75), the CTRX + AZM combination (mean FICI, 0.81), and the GM + AZM combination (mean FICI, 0.83). Additivity/indifference effect was detected for the SPCM + AZM combination, the CDZM + AZM combination, the CTRX + AZM combination, and the GM + AZM combination, against 96 %, 72 %, 92 %, and 100 % of the isolates, respectively. There was no antagonism for any of the antimicrobial combinations against the 25 N. gonorrhoeae isolates. These results suggest that the antimicrobial combinations may be worthy of clinical evaluation as an alternative regimen for gonococcal infections caused by antimicrobial-resistant strains. [ABSTRACT FROM AUTHOR]

Ozenoxacin, a novel non-fluorinated topical quinolone, was assessed for in vitro antimicrobial activity against clinical isolates of propionibacteria and staphylococci according to the broth microdilution method recommended by the Clinical and Laboratory Standards Institute. The isolates used in this study were collected from Japanese patients with acne vulgaris during a period from 2012 to 2013. The MIC90s of ozenoxacin against Propionibacterium acnes (n=266), Propionibacterium granulosum (n=10), Staphylococcus aureus (n=23), Staphylococcus epidermidis (n=229) and other coagulase-negative staphylococci (n=82) were ≤0.06, ≤0.06, ≤0.06, 0.125 and ≤0.06 µg ml-1, respectively. The antimicrobial activity of ozenoxacin against the clinical isolates of propionibacteria and staphylococci was greater than that of five reference antimicrobial agents which have been used for the treatment of acne vulgaris. The MICs of ozenoxacin were correlated with those of nadifloxacin in P. acnes and S. epidermidis isolates. However, the MICs of ozenoxacin were 0.25-0.5 µg ml-1 and 0.5-8 µg ml-1 against nadifloxacin-resistant P. acnes (MIC: ≥8 µg ml-1; n=8) and S. epidermidis (MIC: ≥64 µg ml-1; n=10), respectively. These results indicated the potent antimicrobial activity against P. acnes and S. epidermidis isolates resistant to nadifloxacin. Topical ozenoxacin could represent an alternative therapeutic drug for acne vulgaris based on its potent antimicrobial activity against the isolates of propionibacteria and staphylococci from acne patients.

The effects of bovine lactoferrin (bLF) on the growth of Candida species and on inflammatory cytokine production in gingival keratinocytes, NDUSD-1 co-cultured with Candida strains were investigated. The results showed that bLF at 10 and 100 μg/mL significantly inhibits the growth of two C. albicans strains and two C. glabrata strains isolated from the saliva of elderly people requiring nursing care, respectively. The levels of inflammatory cytokines, interleukin (IL)-6, and IL-8 in NDUSD-1 co-cultured with each of these four Candida strains were measured. C. albicans tend to have a more potent capacity than C. glabrata to induce the production of the inflammatory cytokines in NDUSD-1. The levels of IL-6 and IL-8 in NDUSD-1 co-cultured with each of Candida species were measured after addition of bLF. bLF at concentrations from 1 to 100 μg/mL significantly inhibited the production of these cytokines in NDUSD-1 co-cultured with Candida species. These findings suggest that bLF may be useful in reducing the risk of aspiration pneumonia among elderly people requiring care for whom oral care is difficult.

A high rate of resistance (49.5 to 72.7%) to amoxicillin (AMX) was observed in Helicobacter pylori after two or three unsuccessful eradication attempts. Unsuccessful eradication regimens significantly increase resistance to not only clarithromycin (CLR) and metronidazole (MNZ) but also AMX.

We report the appearance of Candida glabrata strains with reduced sensitivity during treatment with the echinocandin drug micafungin (MCF). Four C. glabrata strains were isolated from sputum, gastric juice, and blood taken from a patient during hospitalization. Two of these strains, one of which was obtained after treatment with MCF for suspected Candida pneumonia and the other of which was obtained during MCF treatment for candidemia, were isolated from blood and found to have a reduced susceptibility to MCF. These two clinical isolates showed a high minimum inhibitory concentration (MIC) for MCF, with this change in MIC being unique for MCF among established antifungal drugs. To further investigate the mechanism underlying this reduced sensitivity, an in vivo mouse infection model and in vitro enzymatic analysis were performed. MCF had little effect in the mouse disseminated infection model and enzymatic analysis showed the low affinity of MCF to the 1,3-Beta-D-glucan synthase of the clinical isolates, although the enzymes of both clinical isolates and control strain were noncompetitively inhibited by MCF. Taken together, this low affinity of MCF for the enzymes is likely to cause the reduced sensitivities. These data further indicate that MCF could induce acquired MCF-resistant strains during clinical use.

Sitafloxacin showed MICs of less than or equal to 0.5 microg/ml against 105 isolates of Helicobacter pylori, including 44 isolates with mutations in the gyrA gene. The highest MICs for garenoxacin and levofloxacin were 8 and 64 times, respectively, higher than the highest MICs observed for sitafloxacin.

Background: Metallo-beta-lactamase is one of the feared resistance mechanisms in Pseudomonas aeruginosa., Methods: beta-Lactamase activity was determined using crude enzymes. Cloned plasmids were transformed in P. aeruginosa KG2505, PAO1 derivative without an AmpC beta-lactamase and a MexAB-OprM efflux pump., Results: P. aeruginosa No. 20232 was highly resistant to imipenem (minimum inhibitory concentration >512 microg/ml). It possessed IMP-10 and the activity was 1.89 +/- 0.42 micromol/min/mg of protein, which was 5-8 times higher than other tested isolates. The bla(IMP-10) promoter was strong (-35 region, TTGACA; -10 region, TAAACT); on the other hand, bla(IMP) of other isolates had a hybrid promoter. Transformants with plasmid encoding bla(IMP-10) with a strong promoter had higher enzymatic activity and were less susceptible to imipenem than those encoding bla(IMP-10) with a hybrid promoter., Conclusions: The high metallo-beta-lactamase activity caused by a strong promoter was a major determinant for high-level imipenem resistance of P. aeruginosa No. 20232., ((c) 2008 S. Karger AG, Basel.)