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Background: Progesterone has long been known to have central effects, by reduced anaesthetic requirements as measured by minimum alveolar concentration (MAC) in various settings. However, other studies have contradicted these findings. Therefore, we compared the effect of progesterone on anaesthetic requirements in a mouse model.Methods: Male C57BL/6 mice were treated with either progesterone (37.5 or 75 mg kg(-1)) or the olive oil vehicle, 1 h before each experiment. Animals were placed in a revolving cylinder (4 rev min(-1)) and supplied with oxygen and stepwise increasing concentrations of sevoflurane. The number of complete rollovers during revolution of the chamber was counted as a measure of anaesthetic requirement.Results: S.C. administration of progesterone 75 mg kg(-1) significantly reduced sevoflurane requirement (P<0.0001). Progesterone 37.5 mg kg(-1) did not change sevoflurane requirement.Conclusions: We conclude that administration of exogenous progesterone injection at higher concentrations decreases anaesthetic requirement as defined by rolling response. [ABSTRACT FROM AUTHOR]

Abstract: Various alloys are interconnected with W using a Ni intermediate layer by the diffusion bonding (DB) technique. During solid-state heating in the DB technique, however, reactive diffusion occurs at the interconnection between Ni and W. In order to examine the kinetics of the reactive diffusion, sandwich Ni/W/Ni diffusion couples were isothermally annealed at temperatures of T =1023–1173K for various times up to t =366h. Owing to annealing, Ni4W is produced as a layer at the Ni/W interface in the diffusion couple and grows predominantly towards Ni. The thickness of the Ni4W layer increases in proportion to a power function of the annealing time. The exponent of the power function is close to 0.5 at T =1173K and gradually decreases with decreasing annealing temperature. Furthermore, grain growth takes place in Ni4W due to annealing. Therefore, volume diffusion is the rate-controlling process for the growth of Ni4W at T =1173K. At T <1173K, however, boundary diffusion contributes to the rate-controlling process, and the contribution of boundary diffusion increases with decreasing annealing temperature. On the other hand, a region alloyed with W is formed in Ni from the Ni4W/Ni interface by diffusion-induced recrystallization (DIR). The growth rate of the DIR region is much greater than the penetration rate of W into Ni by volume diffusion, and the concentration of W in the DIR region at the Ni4W/Ni interface is equal to the solubility of W in Ni. Such growth behavior of the DIR region was numerically analyzed using a mathematical model. The analysis indicates that the growth of the DIR region is controlled by the interface reaction at the moving boundary of the DIR region as well as the boundary diffusion along the grain boundaries across the DIR region under the present annealing conditions. [Copyright &y& Elsevier]

Background. Sevoflurane can be used as a sole agent for intubation in children, but studies have suggested that it is associated with emergence agitation. Fentanyl infusions can be used both to facilitate intubation and decrease emergence agitation. We investigated the effects of fentanyl on conditions at intubation and on emergence from sevoflurane anaesthesia without confounding nitrous oxide or premedication. Methods. IRB approval and informed consent were obtained. Subjects comprised 150 ASA physical status I or II (age, 2-6 yr). Anaesthesia was induced with sevoflurane in oxygen and maintained using a predetermined concentration of sevoflurane. Subjects were randomly allocated to receive one of three doses of fentanyl: vehicle only (control group), a bolus dose of 1 µg kg-1 followed by a continuous infusion of 0.5 µg kg-1 h-1 (F1 group), or a bolus dose of 2 mg kg-1 followed by a continuous infusion of 1 µg kg-1 h-1 (F2 group). Sevoflurane minimum alveolar concentration for tracheal intubation (MACTI) and emergence agitation score were assessed. Results. MACTI values were 2.49%, 1.61%, and 1.16% in control, F1, and F2 groups, respectively (P<0.05). Agitation scores were 11.5, 7.0, and 2.6 in control, F1, and F2 groups, respectively (P<0.05). Conclusions. Fentanyl infusion consisting of a bolus dose of 2 mg kg-1 followed by a continuous infusion of 1 mg kg-1 h-1 facilitates tracheal intubation and smooth emergence in children anaesthetized using sevoflurane. Clinical trial registration: this study was started in 2000 and was finished in 2008. We had no registration number. IRB approval was obtained. [ABSTRACT FROM AUTHOR]

Virgin females of Thysanoplusia intermixta (Lepidoptera; Noctuidae; Plusiinae) produce (5E,7Z)-5,7-dodecadienyl acetate as a main sex pheromone component. GC–MS analysis of the pheromone glands, which were treated with deuterated hexadecanoic, (Z)-11-hexadecenoic, and (Z)-7-dodecenoic acids, showed incorporation of the label into the dienyl component. Their incorporation rates confirmed that its biosynthesis proceeds in the following order: Δ11-desaturation of a C16 acyl intermediate, chain shortening to a C12 compound by β-oxidation, Δ5-desaturation to produce a 5,7-dienyl system, reduction of the acyl group, and acetylation. These deuterated precursors also converted into a minor pheromone component, (Z)-7-docecenyl acetate, which might be prepared by the same pathway except for the step of Δ5-desaturation. While deuterium incorporation into the dienyl acetate was not observed in the extracts treated with other labeled dodecenoic acids with (E)-5-, (Z)-6-, and (E)-7-double bonds, the corresponding dodecenyl acetates were produced. This result showed low substrate specificity of the enzymes for reduction and acetylation. Labeled (Z)-10-hexadecenoic acid was not converted into a dodecenyl acetate, indicating the high substrate specificity of the enzyme for β-oxidation. [Copyright &y& Elsevier]

Stenotrophomonas maltophilia is an important pathogen in healthcare-associated infections. S. maltophilia may contain Smqnr, a quinolone resistance gene encoding the pentapeptide repeat protein, which confers low-level quinolone resistance upon expression in a heterologous host. We investigated the prevalence of Smqnr and plasmid-mediated quinolone resistance (PMQR) determinants in S. maltophilia isolates from Japan. A total of 181 consecutive and nonduplicate clinical isolates of S. maltophilia were collected from four areas of Japan. The antimicrobial susceptibility profiles for these strains were determined. PCR was conducted for Smqnr and PMQR genes, including qnrA, qnrB, qnrC, qnrS, aac(60)-Ib and qepA. PCR products for Smqnr and aac(60)-Ib were sequenced. For the S. maltophilia isolates containing Smqnr, pulsed-field gel electrophoresis (PFGE) was performed using XbaI. Resistance rates to ceftazidime, levofloxacin, trimethoprim-sulfamethoxazole, chloramphenicol and minocycline were 67.4%, 6.1%, 17.7%, 8.8% and 0%, respectively. The minimum inhibitory concentration required to inhibit the growth of 50% and 90% of organisms were 0.5 and 2 mg/L for moxifloxacin but 1 and 4 mg/L for levofloxacin, respectively. Smqnr was detected in 104 of the 181 S. maltophilia isolates (57.5%), and the most frequent was Smqnr6, followed by Smqnr8 and Smqnr11. Eleven novel variants from Smqnr48 to Smqnr58 were detected. The 24 Smqnr-containing S. maltophilia isolates were typed by PFGE and divided into 21 unique types. Nine S. maltophilia isolates (5.0%) carried aac(60)-Ib-cr. No qnr or qepA genes were detected. This study describes a high prevalence of Smqnr and novel variants of Smqnr among S. maltophilia from Japan. Continuous antimicrobial surveillance and further molecular epidemiological studies on quinolone resistance in S. maltophilia are needed. [ABSTRACT FROM AUTHOR]

Over-expression of alpha-phenol-soluble modulins ( PSMs) results in high virulence of community-associated methicillin-resistant Staphylococcus aureus ( MRSA). The psm-mec gene, located in the mobile genetic element SCC mec- II, suppresses PSMαs production. Fifty-two patients with MRSA bacteraemia were enrolled. MRSA isolates were evaluated with regard to the psm-mec gene sequence, bacterial virulence, and the minimum inhibitory concentration ( MIC) of vancomycin and teicoplanin. Fifty-one MRSA isolates were classified as SCC mec- II, and 10 had one point mutation in the psm-mec promoter. We compared clinical characteristics and outcomes between mutant MRSA and wild-type MRSA. Production of PSM α3 in mutant MRSA was significantly increased, but biofilm formation was suppressed. Wild-type MRSA caused more catheter-related bloodstream infections (30/41 vs. 3/10, p 0.0028), whereas mutant MRSA formed more deep abscesses (4/10 vs. 3/41, p 0.035). Bacteraemia caused by mutant MRSA was associated with reduced 30-day mortality (1/10 vs. 13/41, p 0.25), although this difference was not significant. The MIC90 of teicoplanin was higher for wild-type MRSA (1.5 mg/L vs. 1 mg/L), but the MIC of vancomycin was not different between the two groups. The 30-day mortality of MRSA with a high MIC of teicoplanin (≥1.5 mg/L) was higher than that of strains with a lower MIC (≤0.75 mg/L) (6/10 vs. 6/33, p 0.017). Mutation of the psm-mec promoter contributes to virulence of SCC mec- II MRSA, and the product of psm-mec may determine the clinical characteristics of bacteraemia caused by SCC mec- II MRSA, but it does not affect mortality. [ABSTRACT FROM AUTHOR]