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The movement of transition-metal ions was observed in an inhomogeneous magnetic field. The solution containing Cr(super 3+), Mn(super 2+), Co(super 2+), Ni(super 2+), and Cu(super 2+) ions was spotted on a silica gel support and exposed to a magnetic field of 410 kOe(super 2) cm(super -1) intensity x gradient.

This study investigated the efficacy of heated scallop shell powder (HSSP) treatment in preserving chicken thigh meat. Chicken thigh meat was treated with HSSP slurry (1% and 5%) for 60 min, and the variation in aerobic bacteria and coliform populations was assessed during refrigerated storage (10 °C). There was a substantial increase in aerobic bacteria, reaching nearly 7 log 10 colony forming unit (CFU)/g following 7 days of refrigeration, in the untreated chicken meat. Conversely, the aerobic bacterial population of the HSSP-treated chicken was <5 log 10 CFU/g. Coliform growth in the untreated chicken reached over 5 log 10 CFU/g following 7 days. In contrast, the coliform population of the HSSP-treated chicken did not reach 5 log 10 CFU/g at 1% HSSP concentration; it was suppressed to <4 log 10 CFU/g at 5% concentration. Listeria monocytogenes , which can grow at low temperatures, was inoculated into the chicken meat (5 log 10 CFU/g) treated with alcohol, which was followed by HSSP. In the untreated chicken, L. monocytogenes increased to 9 log 10 CFU/g even when refrigerated for 7 days. However, in the chicken treated with 5% HSSP, L. monocytogenes was suppressed to approximately 3 log 10 CFU/g. These findings reveal that HSSP treatment is an effective method for disinfecting meat, inhibiting bacterial growth, and enhancing preservation.

Silicone (polydimethylsiloxane) materials are widely used in various applications. Due to microbe adherence and biofilm formation at the surface of silicone materials, silicone materials must possess antibacterial properties. To achieve this, we prepared copper (Cu)−silicone composite membranes using a simple two-step process of immersion in iodine and copper sulfate solutions. Subsequent scanning electron microscopy revealed Cu nanoparticles (CuNPs) of 10 to 200 nanometers in diameter on the silicone membrane surface, which were identified as copper iodide using energy-dispersive X-ray spectroscopy. The mechanical strength of the material did not change significantly as a result of the two-step immersion treatment and the Cu/silicone membrane showed excellent antibacterial efficacy against Escherichia coli and Staphylococcus aureus, maintaining R > 2 even after a physical impact such as stomacher treatment. Additionally, the Cu ions eluted from the Cu/silicone membrane remained at very low concentrations, suggesting firm immobilization of CuNPs on the silicone membrane. This proposed antimicrobial treatment method does not require special equipment, can be performed at room temperature, and has the potential for use on silicone materials other than membranes.

Methods to reuse large numbers of scallop shells from the harvesting regions of Japan are being explored. The major component of scallop shells is calcium carbonate (CaCO 3 ), which forms the powerful bactericidal agent, calcium oxide (CaO), when heated. Heated scallop shell powder (HSSP) exhibits strong and broad-spectrum antimicrobial activity against bacteria, fungi, and viruses. This study investigated the antibiofilm activity of HSSP against the biofilms of Campylobacter jejuni , which is the predominant species in campylobacteriosis. Biofilm samples of C. jejuni were prepared on 0.45 µm filter paper under microaerobic conditions. The HSSP treatment inactivated and eradicated C. jejuni biofilms. The resistance of C. jejuni biofilms to HSSP was significantly higher than that of the floating cells. Moreover, the antibiofilm activity of the HSSP treatment against C. jejuni biofilms was higher than that of NaOH treatment at the same pH. These results indicated that HSSP treatment is an effective method for controlling C. jejuni biofilms.

Liquid marble (LM), a non-stick drop coated with micro- or nano-scale particles, has great potential in a wide range of applications. LMs have an advantageous feature in which gas or vapor can freely transport through their particle shell; therefore, it makes them an ideal candidate to be utilized as microbioreactor containing aerobic microorganisms. In this study, safer and more biocompatible LMs were successfully prepared using a food-grade calcium stearate microparticle as a stabilizer. As the volume of core liquid increased, the height of LM increased and reached a constant value, as a similar trend has been reported in conventional LMs. The drying rate curve of the LMs confirmed that the LMs have a similar pattern with the drying of typical wet powders. The drying rate depended on the salt species in the core solution and the environmental humidity. For instance, in the case of MgCl 2 , by changing humidity from 40 to 80% RH, the lifetime of LMs (time in which the LM dried completely) was increased to about 900 min. This is nearly three times longer than those have no salt and at 40% RH. Model aerobic bacteria Bacillus subtilis has actively proliferated inside the LM during 24-h incubation. Comparing with the test tube cultivations under O 2 -rich stationary or O 2 rich-shaken conditions, the cultivation in the LM system showed a higher proliferation than the test tube systems. As a conclusion, we demonstrated that the calcium stearate LM system would be an ideal candidate for safer and easily available microbioreactor containing aerobic bacteria.

The effect of food preservatives and sanitizers at low concentrations on the induction of Escherichia coli into a viable but nonculturable (VBNC) state was investigated. When E. coli was incubated in physiological saline at 37℃, the viable cell count measured by plate counting was approximately 3-logs lower than that measured by flow cytometry after 30 days. This difference, and morphological changes in cells, confirmed the transition of E. coli into a VBNC state. Adding 10 μg/l of sorbic acid significantly promoted the induction of E. coli into a VBNC state. This effect was not seen with benzoic acid or sodium hypochlorite at the same concentration. Resuscitation of E. coli VBNC cells was successful when they were grown in nutrient broth containing sodium pyruvate. These results suggest that the presence of low concentrations of food additives in a food manufacturing environment may act as potential triggers for bacterial VBNC induction.

Silicone is widely used in packing materials, medical equipment, and separation membranes. Since microbial cells easily adhere to the surface of silicone materials and form biofilms, techniques for incorporating antimicrobial activity into silicone materials are in high demand. This study describes the preparation of silver (Ag)/silicone composite membranes through a simple two-step immersion process, utilizing an iodine solution followed by a silver nitrate solution at room temperature. Scanning electron microscopy (SEM) observations revealed that particles with sizes of several nanometers to several tens of nanometers were present on the silicone membrane surface; these particles were identified as silver iodide using energy-dispersive X-ray spectroscopy (EDS) . The Ag/silicone membrane possessed excellent antibacterial efficacy against Escherichia coli and Staphylococcus aureus, and the antibacterial efficacy (R) against both types of bacteria was R > 4, even after stomacher treatment or acidic treatment of pH 2-6 for 24 h. The mechanical strength of the silicone membrane was also maintained after antibacterial treatment, with Young's modulus values of 7.9±1.2 MPa and 8.3±1.5 MPa for the untreated membrane and Ag/silicone membrane, respectively (p > 0.05) . In addition, the reduction in permeation performance of the Ag/silicone membrane was only 20%, despite the antibacterial treatment on the membrane surface. This antibacterial treatment method of silicone membranes can be conducted at room temperature (25℃) without special equipment, and may be applied to other types of silicone materials.

We assessed the properties of biofilms (BFs) formed by mono- and co-cultures of Listeria monocytogenes and Pseudomonas aeruginosa (L+P-BF) at low temperatures and examined their sensitivity to several antibacterial substances. L. monocytogenes viable counts comprised only 1-10% of total L+P-BF viable counts at 10℃ and 15℃, indicating the significant prevalence of P. aeruginosa in co-cultures. L+P-BF formed at 10℃ and 15℃ showed very high resistance to antibiotics and NaClO. Examination of the effects of nattokinase and nisin, natural food additives with antibacterial properties, showed that their application alone failed to inhibit L+P-BF development at 10℃ and 15℃. However, a combined treatment with nisin and ethylenediaminetetraacetic acid, a food additive that can be used as a permeabilizing agent, suppressed the formation of L+P-BF at 10℃ and 15℃. Microscopy observations of L+P-BF did not reveal pronounced morphological changes in bacterial cell morphology. We also noted that P. aeruginosa resistance to the action of nisin during BF formation was higher when it was maintained in co-culture with L. monocytogenes. The results of the present study are an important step toward developing a safe formulation of acceptable food additives that could be used for suppression of BFs formed by pathogenic bacteria during food storage.

Scallop shells subjected to heat treatment exhibit antimicrobial activity, and heated scallop-shell powder (HSSP) has recently been reported to be effective for disinfecting food. However, because the main component of these shells is calcium oxide, there is a problem that scales of calcium carbonate (CaCO 3 ) become established on the surface of equipment used for food processing. In this study, we thus investigated whether the addition of sugar to HSSP slurry suppressed CaCO 3 scale generation and whether the sugar-supplemented HSSP could be applied to the disinfection and preservation of fresh lettuce. The results showed that glucose, sucrose, and sorbitol could suppress the scale generation in HSSP slurry. However, glucose and sucrose decreased the antibacterial activity of HSSP. Since the addition of sorbitol did not affect the antibacterial activity of HSSP slurry, it was used for subsequent experiments because of its low bioavailability. Sorbitol effectively suppressed scale formation by dissolving it before the addition of HSSP. The disinfection and preservative effects of sorbitol-supplemented HSSP ( S-HSSP) treatment on lettuce did not decrease compared with those upon HSSP treatment and were almost equal to or higher than those of sodium hypochlorite treatment at 200 mg/l. The addition of sorbitol solved the major problem of scale generation by HSSP containing CaO, which contributes to expansion of usage of heated shell powder, such as HSSP, in food processing.

Potassium dichromate (K 2 Cr 2 O 7 ) is used as a general reference toxicant in aquatic toxicity testing, but relatively little is known regarding the effects of water quality parameters on K 2 Cr 2 O 7 toxicity to Daphnia magna. The acute toxicity of K 2 Cr 2 O 7 to D. magna was comparatively examined in one very hard (M4 medium for D. magna assay), four hard, one moderately hard and one soft dilution water samples. The 48-h EC 50 (50% effective concentration) of K 2 Cr 2 O 7 to D. magna was reproducible (coefficient of variation [CV]: 13%) in tests using the same dilution water sample, but reproducibility was poor (CV: 62%) in tests using seven different dilution water samples. The observed 48-h EC 50 value increased with increasing water hardness (28-250 mg CaCO 3 /L) and Na + concentration (4.3-19.7 mg Na/L). The effect of Ca 2+ and Mg 2+ on K 2 Cr 2 O 7 toxicity was equivalent in terms of molar concentration. The 48-h EC 50 for K 2 Cr 2 O 7 was determined according to OECD TG 202 by six contract laboratories using M4 medium and were shown to be reproducible (CV: 15%), indicating that the toxicity level can be determined with high accuracy if holding and dilution water samples are standardized. Multiple regression analysis revealed that the 48-h EC 50 was strongly correlated (r 2  = 0.927) with the Ca 2+ , Mg 2+ , Na + concentration, and alkalinity of the dilution water samples. Detailed monitoring of water quality characteristics thus facilitates intra- and inter-laboratory comparisons of toxicity data and enables predictions of changes in the susceptibility of test animals., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The inhibition of microbial attachment to food is important for the prevention of cross-contamination during food processing. The effect of several chemicals that were added in an Escherichia coli growth medium on the attachment of the bacterium to lettuce was investigated. E. coli ATCC 25922, which is reportedly a useful surrogate for E. coli O157:H7 in surface attachment studies, was preincubated in a nutrient broth (NB) containing sodium chloride, potassium chloride, sodium deoxycholate, sodium linear alkylbenzene sulfonate, or sorbic acid. The bacterial cells were placed in contact with cut lettuce in a saline solution at 5℃ for 24 hours. Only the addition of NaCl in the NB influenced the attachment of E. coli, Salmonella enterica subsp. Enteritidis, and Klebsiella pneumoniae to the lettuce. The attachment of E. coli showed the largest significant increase at 2% NaCl. Changes in the attachment levels were not due to surface hydrohobicity or the motility of E. coli cells. Similar results were observed for S. enterica although the variation in the degree of attachment of the latter was quite small. These results suggested that the attachment of E. coli O157:H7 to food surfaces is influenced by the bacterial growth conditions prior to food exposure and prior to the development of the biofilm; furthermore, the environmental NaCl concentration should be controlled during food processing to prevent the cross-contamination of foods with E. coli.

The influence of two vehicles (N,N-dimethylformamide [DMF] as solvent and polyoxyethylene hydrogenated castor oil [HCO-40] as a dispersant) on the acute toxicity of eight hydrophobic chemicals with a non-specific mode of action to Daphnia magna was investigated according to the OECD Guidelines for the Testing of Chemicals, No. 202. An increased 48-h EC50 value for D. magna or reduced toxicity resulting from the addition of HCO-40 to the test medium was observed for five of the eight chemicals examined. Each of eight chemicals was dissolved in water at a concentration of either 10 mg/L or 1.0 mg/L, with or without DMF or HCO-40. Silicone film as a model of a biological membrane was then immersed in each solution, and the concentration of each chemical in the water was monitored until equilibrium was reached for each test substance, after which the adsorbed amount of each chemical was determined. The amounts of p-pentylphenol and four other substances with log Pow (1-octanol/water partition coefficient) values greater than 3.4 adsorbed onto the silicone film decreased with increasing concentrations of HCO-40. However, 3-chloro-4-fluoronitrobenzene and two other substances with log Pow values less than 2.6 demonstrated no changes in adsorption with either increasing HCO-40 concentration or the addition of DMF. The reduced adsorption in the presence of a vehicle on the silicone film correlated closely with changes in toxicity. These results indicate that the methodology developed in this study enables the prediction of changes in toxicity resulting from the addition of vehicles to a test system., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The ability of heated scallop-shell powder (HSSP) to work against Listeria sp. biofilm formed at a low temperature was investigated. A biofilm of L. innocua ATCC 33090 was grown on a glass plate at 15˚C for 15 days, then immersed in HSSP slurry. Following treatment, the disinfection ability of the HSSP against the biofilm was non-destructively quantified by conductimetric assay. The biofilm grown at 15˚C was less sensitive than that grown at 37˚C to HSSP treatment and alkaline treatment. The biofilm grown at 15˚C was completely deactivated by 30 min of HSSP treatment (10 mg/mL, pH 12.5). In contrast, after 30 min treatment with alkaline solution at pH 12.5 or sodium hypochlorite (100 ppm), the activity was reduced by only one order of magnitude. The disinfection efficacy of HSSP (10 mg/mL) against L. innocua is similar to or higher than that of sodium hypochlorite (200 ppm). Fluorescence microscopy validated the results of the conductimetric assay. Therefore, HSSP treatment is a potentially powerful alternative control agent against Listeria sp. biofilms that present hazards in the food industry.

Eggshells have high bioavailability and can be used as a source of calcium. The main component is CaCO3, which, when heated, is converted to CaO. Seashells are also mainly composed of CaCO3 and were previously found to exhibit antimicrobial activity after being heated. In this study, heated eggshell powder (HESP) was found to have antimicrobial activity against bacterial vegetative cells, fungi and bacterial spores. Parameters, such as the minimum inhibitory concentration, were determined with kinetic analysis using an indirect conductimetric assay. Moreover, HESP was able to kill the Bacillus subtilis spores. There were no significant differences in the activity between HESP, heated scallop-shell powder and pure CaO. The MIC values for HESP against bacteria and fungi were 0.29-0.43 and 1.3-1.5 mg/mL, respectively. Against B. subtilis spores, a reduction of two orders of magnitude of viability was confirmed following 20 min of treatment at 10 mg/mL at 60 ℃. The active oxygen generated from the HESP slurry was examined with chemiluminescence. The intensity of this increased with increasing concentrations of the HESP slurry. This suggests that HESP could be used as a natural antimicrobial agent. Although a high pH is the main contributor to this antimicrobial activity, active oxygen species generated from HESP are likely to be the main antimicrobial agents..

Background: Effective lung collapse of the nonventilated lung can facilitate thoracic surgery. Previous studies showed that using a bronchial blocker could delay the time of lung collapse compared with using a double-lumen endotracheal tube. We hypothesized that the use of nitrous oxide (N2O) in the inspired gas mixture during 2-lung ventilation would lead to clinically relevant improvement of lung collapse during subsequent 1-lung ventilation with a bronchial blocker., Methods: Fifty patients were randomized into 2 groups: N2O (n =26) or O2 (n = 24). The N2O group received a gas mixture of oxygen and N2O (FIO2 = 0.5), and the O2 group received 100% oxygen until the start of 1-lung ventilation. Lung isolation was achieved with an Arndt® wire-guided bronchial blocker (Cook® Critical Care, Bloomington, IN. After turning patients to the lateral decubitus position, the cuff of the bronchial blocker was inflated under fiberoptic bronchoscopy surveillance, and thereafter, the dependent lung was ventilated with 100% oxygen during 1-lung ventilation in both groups. Surgeons blinded to the randomization evaluated the degree of lung collapse by using a verbal rating scale (lung collapse scale, 0 = no collapse to 10 = complete collapse) at 5 minutes after opening the pleura. Also, as secondary outcomes, lung collapse at 1 and 10 minutes were evaluated., Results: The score on the lung collapse scale in the N2O group was significantly higher compared with the O2 group at 5 minutes after opening the pleura (7 vs 5, P < 0.001, WMWodds = 7.3, 95% confidence interval (CI), 6.0 to 9.0). It was also higher in the N2O group at 10 minutes (10 vs 7, P < 0.001, WMWodds = 10.1, 95% CI, 1.9-13.3). The lung collapse scale between groups was not significant at 1 minute after opening the pleura (2 vs 2, P = 0.76, WMWodds = 1.1, 95% CI, 0.96-1.2). None of the patients developed hypoxia (SpO2 <92%) during 1-lung ventilation., Conclusions: Filling the lung with 50% N2O before 1-lung ventilation facilitated lung collapse 5 minutes after opening the chest compared with 100% oxygen when a bronchial blocker was used. The N2O/O2 mixture (FIO2 = 0.5) did not have a harmful effect on subsequent arterial oxygenation during 1-lung ventilation.

Dolomite is a double salt composed of calcium carbonate (CaCO3) and magnesium carbonate (MgCO3). The heat treatment of CaCO3 and MgCO3 respectively generates calcium oxide (CaO) and magnesium oxide (MgO), which have antimicrobial activity. In this study, heated dolomite powder (HDP) slurry was investigated for its sporicidal activity against Bacillus subtilis ATCC 6633 spores. The B. subtilis spores used in this study were not affected by acidic (pH 1) or alkaline (pH 13) conditions, indicating that they were highly resistant. However, dolomite powder heated to 1000℃ for 1 h could kill B. subtilis spores, even at pH 12.7. Sporicidal activity was only apparent when the dolomite powder was heated to 800℃ or higher, and sporicidal activity increased with increases in the heating temperature. This temperature corresponded to that of the generation of CaO. We determined that MgO did not contribute to the sporicidal activity of HDP. To elucidate the sporicidal mechanism of the HDP against B. subtilis spores, the generation of active oxygen from HDP slurry was examined by chemiluminescence analysis. The generation of active oxygen increased when the HDP slurry concentration rose. The results suggested that, in addition to its alkalinity, the active oxygen species generated from HDP were associated with sporicidal activity.

Heated scallop-shell (HSS) nano-particles, prepared using a wet grinding mill, and microparticles were examined for their antibacterial activity against vegetative bacterial cells and spores. The median diameters of the nano-particles and micro-particles were approximately 20 nm and 30 µm, respectively. The antibacterial activity of HSS against Escherichia coli increased with an increase in concentration, regardless of particle size; however, the antibacterial activity of the nano-particles was much higher than that of micro-particles. The sporicidal activity of the nano-particles was also much higher than that of micro-particles, with HSS nano-particles able to kill Bacillus subtilis spores. A reduction of more than three orders of magnitude for B. subtilis spores was confirmed following a 30 min treatment at 5 mg/ml and 60℃, showing that the combination of HSS nano-particle treatment with mild heating was particularly effective for controlling bacterial spores.

Respiratory syncytial virus (RSV) infection in children can be associated with acute encephalopathy. However, the roles of cytokines in the cerebrospinal fluid (CSF) of such patients remain unevaluated. In this study, a profile of 17 cytokines was determined for eight RSV-infected children with neurological complications. In one patient with high levels of 13 cytokines, a cytokine storm was considered to have occurred. Interleukin (IL)-6, IL-8, monocyte chemoattractant protein (MCP)-1, and macrophage inflammatory protein (MIP)-1β levels were also high in other patients. These data suggest that chemokines in CSF play roles in neurological complications in RSV-infected children.

Bacteria capable of degrading 4-nonylphenol (NP) were isolated and identified, and their ability to degrade NP was determined. The screening of microorganisms in river water and soil led to a collection of 23 strains of bacteria and five strains of fungi. Two strains of bacteria, identified as Pseudomonas sp. and Acidovorax sp., possessed great ability for degrading NP. The NP degradation rate of Pseudomonas sp. did not change with the NP concentration (50-100mg/L) . In contrast, the NP degradation rate of Acidovorax sp. increased with increasing NP concentration. Acidovorax sp. possessed the greatest NP degradation activity at 35°C. No NP degradation activity was observed for Pseudomonas sp. at temperatures higher than 30°C. Even when non-NP carbon sources such as glucose or sucrose were added, the NP degradation rates for both bacteria did not decrease. In addition, the estrogenic activity of NP decreased depending on the amount of NP residues determined by the yeast two-hybrid system.

Bronchoscopy with an yttrium-aluminium-garnet (YAG) laser is often used to resect benign and malignant airway tumors and for relief of associated airway stenosis. Complications of this procedure include airway obstruction and hemorrhage. Partial extracorporeal circulation for YAG laser resection in the airway may be helpful in minimizing these complications. Extracorporeal lung assist (ECLA) should be available for such bronchoscopic surgery, although it is not always required. We managed the general anesthesia for bronchoscopic YAG laser resection of airway tumors in two patients. The first case was a 60-year-old man with a right bronchial tumor that had invaded into the trachea across the carina. The narrowest inner diameter of the part of the trachea affected by the lesion was 3 mm. ECLA was initiated for a bronchoscopic YAG laser resection. The second case was a 74-year-old woman with a metastastic lung tumor from osteosarcoma. The narrowest inner diameter of the lesion in the right truncus intermedius was 4 mm. ECLA was kept on standby for possible complications in the bronchoscopic YAG laser resection. These treatments were completed successfully in both patients without any adverse events. ECLA is a useful supporting technique for performing bronchoscopic YAG laser treatment safely ECLA is recommended where a bronchial lesion invades the trachea and crosses the carina, and where a tracheal lesion will not allow passage of a tracheal tube under the bronchoscope. However, ECLA may be kept on standby for a airway tumor limited to one main bronchus, and for a peripheral bronchial lesion, and even for an invasive tracheal lesion through which the tracheal tube under the bronchoscope can pass. Whether it is used or kept on standby depends on the location and severity of airway compromise caused by the airway lesions.

Scallop shells are used to make food additives and plastering and paving materials. However, most of the shell is considered commercial waste. In scallop-harvesting districts, large numbers of shells are heaped near the seaside, which creates problems such as offensive odors and soil pollution from heavy metals that leach out of the viscera. Therefore, new applications for scallop shells need to be developed. The main component of scallop shells is calcium carbonate (CaCO(3)), which is converted to calcium oxide (CaO) when heated. Heated scallop shell powder (HSSP) possesses broad antimicrobial action against the vegetative cells of bacteria, spores, and fungi. HSSP applied to fresh vegetables and processed foods reduces the number of viable bacterial cells. The use of HSSP in food processing provides a source of minerals and prolongs the shelf life of foodstuffs. Moreover, reducing the amount of scallop shell waste would reduce the related pollution problem. This report is a review of the antibacterial activity of HSSP and its application for the control of microbes.

The NADase (Nga) of group A streptococci (GAS) has been implicated in the pathogenesis of diseases such as streptococcal toxic shock-like syndrome (STSS) and necrotizing fasciitis. In this study we found that the proportion of NADase-positive strains among clinical isolates in Japan has increased over time. The GAS strains studied could be divided into three groups: strains lacking NADase activity, strains with low NADase activity, and strains with high NADase activity. The older strains, isolated before 1989, belonged to the 'no activity' group. Analysis using GST-Nga recombinants revealed that nga alleles of representative older strains encode inactive Nga. Mutational analysis of the GST-Nga recombinants suggested that residue 330 could be associated with reduced activity, based upon deduced amino acid sequences. We also investigated NADase activity of streptococcal strains other than GAS. All group G streptococcal isolates from STSS patients possessed nga genes encoding active enzymes.

Particles of ZnO coated with carbon (ZnOCC) were prepared and evaluated for their antibacterial activity. ZnO powder and poly(vinyl alcohol) (PVA) (polymerization degree: 2,000-95,000) were mixed at a mass ratio (ZnO/PVA) of 1, and then heated at 500-650 degree C for 3 h under argon gas with a flow rate of 50ml/min. Carbon deposited on the ZnOCC surface was amorphous as revealed by X-ray diffraction studies. The ZnOCC particles maintained their shape in water, even under agitation. The antibacterial activity of ZnOCC powder against Staphylococcus aureus was evaluated quantitatively by measuring the change in the electrical conductivity of the growth medium caused by bacterial metabolism (conductimetric assay). The conductivity curves obtained were analyzed using the growth inhibition kinetic model proposed by Takahashi for calorimetric evaluation, allowing the estimation of the antibacterial efficacy and kinetic parameters of ZnOCC. In a previous study, when ZnO was immobilized on materials, such as activated carbon, the amount of ZnO immobilized was approximately 10-50%, and the antibacterial activity markedly decreased compared to that of the original ZnO. On the other hand, the ZnOCC particles prepared in this study contained approximately 95% ZnO and possessed antibacterial activity similar to that of pure ZnO. The carbon-coating treatment could maintain the antibacterial efficacy of the ZnO and may be useful in the develop-ment of multifunctional antimicrobial materials.

The administration of high-dose clindamycin plus benzylpenicillin has been recommended for the treatment of streptococcal toxic shock-like syndrome caused by Streptococcus pyogenes, and clindamycin has been found to be more effective than beta-lactams in retrospective analyses of human cases. Although therapeutic doses of clindamycin have also been shown to be effective against experimental infections and clindamycin has great efficacy against the production of bacterial exoproteins, we recently reported that the level of production of some exoproteins was unchanged or even increased by a subinhibitory dose of clindamycin when it is added upon the initiation of bacterial culture and the treated cultures were analyzed by two-dimensional gel electrophoresis. In this study we further examined the effect of clindamycin on the production of exoproteins by adding it to Streptococcus pyogenes cultures during various growth phases. We found that the levels of production of some proteins, NAD+ glycohydrolase, streptolysin O, and streptococcal inhibitor of complement, were increased when clindamycin was added at early-log-phase growth, which was the result that was seen when clindamycin was added at the beginning of culture. However, clindamycin inhibited the production of most types of proteins when it was administered to Streptococcus pyogenes cultures at mid-log-phase growth. In csrS- or mga-knockout bacterial strains, the increase in exoproteins seen in parental strains was considerably inhibited. Our study indicates that the in vitro effect of clindamycin on the production of exoproteins greatly depends on the growth phase of bacteria and some regulatory factors of Streptococcus pyogenes that are involved in this phenomenon.

The antifungal activity of scallop-shell powder heated at 1000 degrees C for 1 h against Trichophyton was kinetically investigated and the possibility of applying the powder to the treatment of dermatophytosis was examined. The death rate of T. mentagrophytes NBRC5466 in the heated shell powder slurry increased with powder concentration, following first-order reaction kinetics. Elevated slurry temperatures increased both the apparent first-order death rate constant (k) and the dilution coefficient (n) representing the dependence of k on reagent concentration. The activation energy for the death of NBRC5466 was almost equal to that for bacteria, whereas the n value was much smaller than that for bacteria. In addition, the trial using heated shell powder treatment on feet showed the possibility of its application to treat dermatophytosis.

The inactivation of Escherichia coil by infrared (IR) irradiation was quantitatively evaluated and compared to that by thermal conductive heating. After the bulk temperature of the sterile saline irradiated by IR reached a steady given temperature, the E. coil culture was inoculated and IR heating was conducted. A mullite cylinder FIR heater, of which main wavelength is 4-7 microm, was used for IR heating. The killing of the E. coil by IR heating and thermal conductive heating both followed first-order reaction kinetics, and the apparent death rate constants (k) under different conditions were obtained. At the same temperatures, pasteurization by IR heating was more effective than that by thermal conductive heating, and its effectiveness increased with a decrease in liquid layer thickness. The values of k due to IR heating were approximately 2-3 times and one order larger than those due to thermal conductive heating at the liquid layer thickness of 10 mm and 1.5 mm, respectively. The activation energy (Ea) for the killing of E. coli by IR irradiation was slightly lower than that by thermal conductive heating, indicating that there are some differences in the action mechanisms.

Purpose: Floppy eyelid syndrome (FES) presents nonspecific ocular surface irritation. The hypothesis for the current study was that one contributing factor is the abnormality in tear film dynamics., Methods: Sixteen patients with FES were consecutively examined. Tear film dynamics were evaluated by kinetic tear interference images, infrared thermometry, water evaporation rate, tear break-up time, and fluorescein clearance test. Data showing evaporation rate and thermometry were compared with those of 10 normal subjects., Results: There was a high correlation between the eye with the worse symptoms and the eyes with the more severe floppy lids (P < 0.01) and with ocular surface evaporation rate (P = 0.02). Except for one patient, all others showed abnormal tear film, with an average tear break-up time of 2.9 +/- 3.7 seconds. Kinetic analysis of tear interference images revealed that lipid spread in a vertical or mixed pattern in 18 eyes (75%) with a delayed spread time (P = 0.0007), indicating that most of the patients had lipid tear deficiency. The ocular skin temperature and water evaporation rate were higher in the FES group (P = 0.0003 and 0.026, respectively). Nearly all patients with FES showed eyelid hyperpigmentation. The ocular surface evaporation rate in the FES group was also higher than that of the normal subjects (P < 0.0001). Multiple regression analysis showed that a vertical pattern of lipid spread had a significant influence on ocular surface evaporation rate (P = 0.003)., Conclusions: Tear film abnormality is prevalent in patients with FES and is characterized by lipid tear deficiency, leading to rapid tear evaporation. The FES lid skin is also characterized by high temperature, high water evaporation rate, and hyperpigmentation. Studies directed to investigating the linkage of lid changes and meibomian gland dysfunction may shed new lights on the pathogenesis of FES.

Zinc oxide powders were heated in different atmospheres at 800 and 1400 degrees C, of which the characterization and the antibacterial activity were studied by X-ray diffractometry and the measurement of the change in electrical conductivity with bacterial growth. The diffraction peaks corresponding to zinc oxide with hexagonal type structure were detected in all samples, which shifted in low-angle side with the increase in the oxidizability of atmosphere during heat-treatment. From the results of calculating lattice constants, a0 and c0, it was found that the value of c0 in hexagonal structure increased with the increase in the oxidizability of atmosphere. On the samples heated at 1400 degrees C, the changes of the c0 value were less than those at 800 degrees C. However, no change of the a0 value showed, irrespective of atmosphere and temperature. Hydrogen peroxide that contributes to the occurrence of antibacterial activity was found to generate from all samples, and the generation amount increased with the increase of c0 value; incidently the amount in the samples heated at 1400 degrees C was less than that at 800 degrees C. The antibacterial activity of zinc oxide increased with the increase of c0 value; that is, it was found that the value of c0 in crystal structure affected the antibacterial activity of zinc oxide.