Prevalence of Smqnr and plasmid-mediated quinolone resistance determinants in clinical isolates of Stenotrophomonas maltophilia from Japan: novel variants of Smqnr.

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(6')-Ib and qepA. PCR products for Smqnr and aac(6')-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(6')-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.

The relationship between age and minimum alveolar concentration of sevoflurane for maintaining bispectral index below 50 in children.

We evaluated the minimum alveolar concentration of sevoflurane required to maintain the bispectral index below 50 in children. We studied 55 children, divided into 1-year-old, 2- to 4-year-old and 5- to 9-year-old groups and used Dixon's up-and-down method and probit analysis. In the 1-year-old group, the bispectral index values remained above 50, with the end-tidal sevoflurane concentration reaching 4.0% or higher. The minimum alveolar concentration of sevoflurane for maintaining the bispectral index below 50 was significantly higher in the 2- to 4-year-old group (2.33%, 95% CI 2.25-2.57) than in the 5- to 9-year-old group (2.10%, 95% CI 1.94-2.25; p = 0.005). We conclude that assessing the depth of anaesthesia using bispectral index is unreliable in children aged < 2 years anaesthetised with sevoflurane.

Impact of psm-mec in the mobile genetic element on the clinical characteristics and outcome of SCCmec-II methicillin-resistant Staphylococcus aureus bacteraemia in Japan.

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 SCCmec-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 SCCmec-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 PSMα3 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 SCCmec-II MRSA, and the product of psm-mec may determine the clinical characteristics of bacteraemia caused by SCCmec-II MRSA, but it does not affect mortality.

Effects of fentanyl infusion on tracheal intubation and emergence agitation in preschool children anaesthetized with sevoflurane.

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 microg kg(-1) followed by a continuous infusion of 0.5 microg kg(-1) h(-1) (F1 group), or a bolus dose of 2 microg kg(-1) followed by a continuous infusion of 1 microg kg(-1) h(-1) (F2 group). Sevoflurane minimum alveolar concentration for tracheal intubation (MAC(TI)) and emergence agitation score were assessed. RESULTS: MAC(TI) 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 microg kg(-1) followed by a continuous infusion of 1 microg 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.

Progesterone decreases sevoflurane requirement in male mice: a dose-response study.

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.

Long-term effect of modification of dietary protein intake on the progression of diabetic nephropathy: a randomised controlled trial.

AIMS/HYPOTHESIS: There is currently insufficient evidence to recommend a low-protein diet for type 2 diabetic patients with diabetic nephropathy. We assessed whether a low-protein diet could prevent the progression of diabetic nephropathy. METHODS: This was a multi-site parallel randomised controlled trial for prevention of diabetic nephropathy progression among 112 Japanese type 2 diabetic patients with overt nephropathy. It was conducted in Japan from 1 December 1997 to 30 April 2006. The participants were randomly assigned using a central computer-generated schedule to either low-protein diet (0.8 g kg(-1) day(-1)) and normal-protein diet (1.2 g kg(-1) day(-1)), and were followed for 5 years. The participants and investigators were not blinded to the assignment. The primary outcomes were the annual change in estimated GFR and creatinine clearance, the incidence of doubling of serum creatinine and the time to doubling of baseline serum creatinine. RESULTS: The study was completed by 47 (84%) of 56 participants in the low-protein diet group and 41 (73%) of 56 participants in the normal-diet group. During the study period, the difference in mean annual change in estimated GFR between the low-protein diet and the normal-protein diet groups was -0.3 ml min(-1) 1.73 m(-2) (95% CI -3.9, 4.4; p = 0.93). The difference in mean annual change in creatinine clearance between the low-protein diet and the normal-protein diet groups was -0.006 ml s(-1) 1.73 m(-2) (95% CI -0.089, 0.112; p = 0.80). A doubling of serum creatinine was reached in 16 patients of the low-protein group (34.0%), compared with 15 in the normal-protein group (36.6%), the difference between groups being -2.6% (95% CI -22.6, 17.5; p = 0.80). The time to doubling of serum creatinine was similar in both groups (p = 0.66). CONCLUSIONS/INTERPRETATION: It is extremely difficult to get patients to follow a long-term low-protein diet. Although in the low-protein group overall protein intake was slightly (but not significantly) lower, it did not confer renoprotection. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT00448526. FUNDING: Research grant from the Ministry of Health, Labour and Welfare of Japan.

Function of oleic acid on epidermal barrier and calcium influx into keratinocytes is associated with N-methyl D-aspartate-type glutamate receptors.

BACKGROUND: Unsaturated fatty acids from sebum affect calcium dynamics in epidermal keratinocytes, disrupt the barrier function and induce abnormal keratinization. However, the mechanisms of these effects have not been clarified. OBJECTIVES: To investigate the function of unsaturated fatty acids in epidermis. METHODS: Antagonists of calcium channel receptors were applied to mouse skin together with oleic acid. Measurements were made of transepidermal water loss (TEWL), and hyperproliferation was assessed. The effects of the antagonists on calcium influx into cultured normal human keratinocytes and on cytokine production were also evaluated. RESULTS: N-methyl-d-aspartate (NMDA) receptor antagonists such as MK801 and D-AP5 specifically inhibited the increase in TEWL caused by oleic acid, and suppressed keratinocyte hyperproliferation. These compounds also inhibited the increase in the intracellular concentration of calcium ions induced by oleic acid. MK801 suppressed the production of interleukin-1alpha by keratinocytes induced by oleic acid. CONCLUSIONS: Unsaturated fatty acids such as oleic acid might function via NMDA receptors.

Convulsions after ropivacaine 300 mg for brachial plexus block.

A healthy 18-yr-old male (weight 60 kg, height 167 cm), with a history of febrile convulsions in childhood, developed a grand mal convulsion 10 min after the second of two injections of ropivacaine 150 mg, both given incrementally 15 min apart (total 300 mg), for combined axillary/interscalene brachial plexus block. Treatment was with oxygen, lung ventilation, and i.v. midazolam, and the patient made a complete recovery. Arterial plasma ropivacaine concentration 2 min after the onset of convulsions was only 2.13 mg litre(-1), suggesting that this patient was particularly susceptible to local anaesthetic toxicity. Whether sub-clinical EEG changes identified after operation were related to this sensitivity cannot be determined, but review illustrates wide variation in both the dose and the plasma concentration of local anaesthetics associated with systemic toxicity. The UK recommended dose of ropivacaine for brachial plexus block is 225-300 mg according to stature.

A study of the in vitro interaction between lidocaine and premedications using human liver microsomes.

OBJECTIVE: To investigate potential interactions between lidocaine (lignocaine) metabolism and premedication drugs, i.e. psychotropic and antianxiety agents (diazepam, midazolam), hypnotics (pentobarbital, thiamylal), depolarizing neuromuscular blocking agents (vecuronium, pancuronium and suxamethonium), an antihypertensive agent (clonidine) and an H2-receptor blocking agent (cimetidine) using human liver microsomes in vitro. METHODS: The interaction effects between lidocaine and premedication were examined using human liver microsomal preparations and monitored for enzyme activity. The lidocaine and its main metabolite (monoethylglycinexylide) were measured by HPLC/UV. RESULTS: Lidocaine metabolism was non-competitively inhibited by midazolam (Ki = 77.6 microM). Thiamylal was a competitive inhibitor of lidocaine metabolism (Ki = 885 microM). Cimethidine, pancuronium and vecuronium weakly inhibited lidocaine metabolism in a concentration-depend manner over the therapeutic range in human liver microsomes. On the contrary, suxamethonium, pentobarbital and clonidine did not inhibit lidocaine metabolism over the therapeutic range in human liver microsomes. CONCLUSION: These results show that the interactions between lidocaine and midazolam and thiamylal are of potential toxicological and clinical significance.

Inhibition of matrix metalloproteinase-2 activity by siderophores of Pseudomonas species.

To obtain a novel matrix metalloproteinase (MMP) inhibitor produced by bacteria, we have focused on the chelating activity of siderophores. Several siderophore-producing bacteria were isolated from soil using chrome azurol S agar plates and then the effect of siderophores on MMP-2 activity was assayed by gelatin zymography. The results showed that partially purified siderophores from ten isolated strains inhibited MMP-2 activity. Among these strains, two were non-fluorescent and eight were fluorescent Pseudomonas species. From these eight strains, pyoverdine-type siderophores were detected. The Zn(2+)-chelating activity of these siderophores correlated with the inhibition of MMP-2 activity. Therefore, it is considered that siderophores such as pyoverdines inhibit MMP-2 activity by chelating Zn(2+) on the active site of MMP-2.

Evaluation of autologous cultured epithelium as replacement skin after tattoo excision: correlation between skin texture and histological features.

BACKGROUND: Cultured epidermal autographs (CEAs) are currently used as a coverage treatment for burn wounds, for disfiguring burn scars involving depigmentation and in restoring the elasticity of the skin. The advantage of CEAs is that epidermal sheets prepared from small skin pieces can be enlarged sufficiently to cover large burn areas. OBJECTIVES: We examined the correlation between recovery of skin texture, and elastic fibre formation and keratinocyte differentiation (assessed by immunohistochemistry) in CEAs used as replacement skin after tattoo excision in a Japanese patient. METHODS: The tattooed skin was excised down to the deep dermal layer and then CEA was transplanted onto the patient. The skin textures were evaluated by taking replicas of the skin surface, and histological changes of filaggrin, transglutaminase, involucrin, fibrillin and elastin in the autograft skin were examined by immunohistochemistry. RESULTS: The skin texture improved with time after grafting the CEA, and appeared similar to that of normal skin at 39 months. Among keratinocyte differentiation markers, filaggrin recovered to a normal pattern at around 6 months, and transglutaminase did so at 39 months, whereas involucrin expression remained abnormal at 39 months. Fibrillin expression appeared similar to that of normal skin by 39 months, except for sparse candelabra-like structures of short fibres. Elastin expression remained at a low level throughout. CONCLUSIONS: Our results show that the recovery of skin texture after application of CEAs following tattoo excision is associated with the normalization of epidermal differentiation markers, except involucrin, and with the regeneration of elastic fibres in the dermis.

A study of the in vitro clinical interaction between lidocaine and premedications using rat liver microsomes.

In this study, we have investigated the relationship between lidocaine metabolism and premedication, i.e., psychotropic and anti-anxiety agents (diazepam, midazolam), hypnotics (pentobarbital, thiamylal), depolarizing muscular relaxants (vecuronium, pancuronium and suxamethonium), an active anti-hypertensive (clonidine) and an H2 receptor antagonist (cimetidine) using rat hepatic microsomes in vitro. Lidocaine metabolism was noncompetitively inhibited by midazolam (Ki=29.0 microM). Thilamylal was a moderate competitive inhibitor of lidocaine metabolism (Ki=77.8 microM). Pentobarbital, diazepam and cimetidine weakly inhibited lidocaine metabolism formation in a concentration-dependent manner at high substrate concentrations. On the other hand, vecuronium, pancuronium, suxamethonium and clonidine did not inhibit lidocaine metabolism over the therapeutic range. These results show that the interaction between lidocaine and midazolam and thiamylal, catalyzed by a similar cytochrome P450, is of potential importance in toxicological and clinical studies.

Biosynthetic pathway for production of a conjugated dienyl sex pheromone of a Plusiinae moth, Thysanoplusia intermixta.

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: Delta11-desaturation of a C(16) acyl intermediate, chain shortening to a C(12) compound by beta-oxidation, Delta5-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 Delta5-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 beta-oxidation.

Plasma lidocaine concentrations during continuous thoracic epidural anesthesia after clonidine premedication in children.

UNLABELLED: There is no report concerning oral clonidine's effects on epidural lidocaine in children. Therefore, we performed a study to assess the concentrations of plasma lidocaine and its major metabolite (monoethylglycinexylidide [MEGX]) in children receiving continuous thoracic epidural anesthesia after oral clonidine premedication. Ten pediatric patients, aged 1-9 yr, were randomly allocated to the Control or Clonidine 4 microg/kg group (n = 5 each). Anesthesia was induced and maintained with sevoflurane in oxygen and air (FIO2 40%). Epidural puncture and tubing were carefully performed at the Th11-12 intervertebral space. An initial dose of 1% lidocaine (5 mg/kg) was injected through a catheter into the epidural space, followed by 2.5 mg x kg(-1) x h(-1). Plasma concentrations of lidocaine and MEGX were measured at 15 min, 30 min, and every 60 min for 4 h after the initiation of continuous epidural injection. The concentrations of lidocaine and MEGX were measured using high-pressure liquid chromatography with ultraviolet detection. Hemodynamic variables were similar between members of the Control and Clonidine groups during anesthesia. The Clonidine group showed significantly smaller lidocaine concentrations (p < 0.05) and the concentration of MEGX tended to be smaller in the plasma of the Clonidine group for the initial 4 h after the initiation of epidural infusion. In conclusion, oral clonidine preanesthetic medication at a dose of 4 microg/kg decreases plasma lidocaine concentration in children. IMPLICATIONS: Oral clonidine decreases the plasma lidocaine concentration in children. Our finding may have clinical implications in patients receiving continuous epidural anesthesia. Additionally, perhaps an additional margin of safety regarding lidocaine toxicity is gained through the use of oral clonidine in children who will receive epidural lidocaine.

[Anesthetic management for left ventricular assist device implantation in patients waiting for heart transplantation].

We report the anesthetic management of patients with dilated cardiomyopathy who underwent left ventricular assist device implantation (LVAD). Anesthesia was induced and maintained with midazolam and fentanyl. Transesophageal echocardiography (TEE) and a PA catheter were useful for hemodynamic monitoring and management of the patients. Furthermore, TEE is useful for the early detection of inflow of the air which is absorbed by negative pressure derived from high LVAD support pressure. On starting LVAD support, evaluation of right ventricular function and treatment for right ventricular failure were important and necessary for the patients. Added to conventional therapy using catecholamines, inhaled nitric oxide may provide a favorable effect for right ventricular failure.

The clinical importance of conventional and quantitative liver function tests in liver transplantation.

The advantages and disadvantages of using monoethylglycinexylidide (MEGX), the major metabolite of lidocaine, as a probe of hepatic function in liver transplantation are reviewed. A 'real time' test of liver function should give a measure of current hepatocellular capacity rather than reflect past damage. The hepatic metabolism of lidocaine to MEGX is the basis of a flow-dependent dynamic test of liver function. In pre-transplantation patients, data from this MEGX test support its role in assessing the risk of morbidity and mortality. In assessing the liver transplant donor, there are differences concerning its apparent usefulness and these must be resolved. In the liver transplant recipient, this MEGX test is also useful for measuring real-time hepatic metabolizing activity, and low MEGX values reflect the clinical condition of the patient. At present, however, this test has several limitations. Therefore, a comprehensive evaluation, not only by the MEGX test but also by a combination of other conventional liver function tests (biochemical parameters, etc.), or with histological evaluation, is thought to be desirable for deciding whether a liver transplantation should be carried out or not.

Regulation of sex pheromone biosynthesis in three plusiinae moths: Macdunnoughia confusa, Anadevidia peponis, and Chrysodeixis eriosoma.

Virgin females of M. confusa, A. peponis, and C. eriosoma secrete (Z)-7-dodecenyl acetate as a common main pheromone component. Their pheromone titers decreased after decapitation, and increased in the decapitated females after injection of a synthetic hormone, pheromone biosynthetic activating neuropeptide (PBAN) of Bombyx mori. In addition, an extract of brain-subesophageal ganglion complexes of each Plusiinae species activated pheromone biosynthesis in decapitated females of not only the corresponding species, but also that of Mamestra brassicae. These results indicate that pheromone biosynthesis of the three Plusiinae species is also controlled by a PBAN-like substance. However, the Plusiinae females exceptionally contained remarkable amounts of the pheromone even 1 day after decapitation. Since it has been reported that pheromones completely disappear at least 1 day after decapitation in females of many other lepdidoptran species including B. mori and M. brassicae, a different mechanism is likely regarding the regulation of the studied Plusiinae pheromone biosynthesis. Furthermore, an incorporation experiment with a labeled pheromone precursor, D9-(Z)-7-dodecenoic acid, showed that moderate biosynthesis still proceeded in the pheromone glands of M. confusa females 1 day after decapitation, providing an evidence why complete disappearance of the pheromone was not observed in the females which otherwise lacked a source of the pheromonotropic neuropeptide.

Reduction in standard MAC and MAC for intubation after clonidine premedication in children.

We examined the relative effects of different doses of oral clonidine on the MAC for endotracheal intubation (MACEI) and the MAC for skin incision (MAC) in children. We studied 90 children (15 in each group) (age range 2-8 yr, weight 10-27 kg, height 89-124 cm) who received one of three preanaesthetic medications: placebo (control), oral clonidine 2 micrograms kg-1, or oral clonidine 4 micrograms kg-1 100 min before anaesthesia. Anaesthesia was induced and maintained with sevoflurane in oxygen and air without i.v. anesthetics and neuromuscular relaxants. The end-tidal sevoflurane concentration was kept constant for > or = 15 min before tracheal intubation or skin incision. MACs were determined using Dixon's 'up-and-down method'. Mean (SD) MACEIs of sevoflurane were 2.9 (0.1)%, 2.5 (0.1)% and 1.9 (0.1)% (P < 0.05), and MACs were 2.3 (0.1)%, 1.8 (0.1)% and 1.3 (0.1)% (P < 0.05), respectively, in control, clonidine 2 micrograms kg-1 and clonidine 4 micrograms kg-1 groups. The MACEIs and MACs decreased dose-dependently. The MACEI/MAC ratio (1.4) was not affected by clonidine.