Prevalence of, and risk factors for, carriage of carbapenem-resistant Enterobacteriaceae among hospitalized patients in Japan.

BACKGROUND: The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) has been reported to be lower in Japan than in many other countries. However, extensive surveillance for CRE carriage has not been performed in Japan. AIM: To investigate the prevalence of CRE carriage in Japan among convalescent patients considered to be at high risk of being CRE carriers using an improved selective culture medium. METHODS: A cross-sectional survey was conducted in 22 acute care hospitals (ACHs) and 21 long-term care hospitals (LTCHs) in northern Osaka from December 2015 to January 2016. Patients who used incontinence aids, an enteral feeding tube or a urinary catheter were enrolled. Faecal specimens were examined using the newly developed M-ECC for imipenemase (IMP)-producing CRE, which is the most prevalent form of CRE in Japan. The positive isolates were analysed by polymerase chain reaction and sequencing. Risk factors associated with carriage were analysed by logistic regression. FINDINGS: Among 1507 patients, 184 (12.2%) carried CRE. The percentage of positive patients was significantly higher in LTCHs (14.9%) than in ACHs (3.6%) (P<0.001). Risk factors for CRE carriage were longer hospital stay [odds ratio (OR) 2.59; 95% confidence interval (CI) 1.87-3.60], enteral feeding (OR 3.03, 95% CI 2.08-4.42) and antibiotic exposure (OR 2.00, 95% CI 1.40-2.87). Among the 233 CRE isolates identified, 223 were IMP producers; the remaining isolates did not produce carbapenemase. CONCLUSIONS: This is the first Japanese report to demonstrate the significant spread of CRE in both ACHs and LTCHs using an improved selective medium. A coordinated regional approach may help to prevent further spread.

Anisotropy of the superconducting gap in the iron-based superconductor BaFe2(As(1-x)P(x))2.

We report peculiar momentum-dependent anisotropy in the superconducting gap observed by angle-resolved photoemission spectroscopy in BaFe2(As(1-x)P(x))2 (x = 0.30, Tc = 30 K). Strongly anisotropic gap has been found only in the electron Fermi surface while the gap on the entire hole Fermi surfaces are nearly isotropic. These results are inconsistent with horizontal nodes but are consistent with modified s ± gap with nodal loops. We have shown that the complicated gap modulation can be theoretically reproduced by considering both spin and orbital fluctuations.

Dependence of carrier doping on the impurity potential in transition-metal-substituted FeAs-based superconductors.

In order to examine to what extent the rigid-band-like electron doping scenario is applicable to the transition metal-substituted Fe-based superconductors, we have performed angle-resolved photoemission spectroscopy studies of Ba(Fe(1-x)Ni(x))(2)As(2) (Ni-122) and Ba(Fe(1-x)Cu(x))(2)As(2) (Cu-122), and compared the results with Ba(Fe(1-x)Co(x))(2)As(2) (Co-122). We find that Ni 3d-derived features are formed below the Fe 3d band and that Cu 3d-derived ones further below it. The electron and hole Fermi surface (FS) volumes are found to increase and decrease with substitution, respectively, qualitatively consistent with the rigid-band model. However, the total extra electron number estimated from the FS volumes (the total electron FS volume minus the total hole FS volume) is found to decrease in going from Co-, Ni-, to Cu-122 for a fixed nominal extra electron number, that is, the number of electrons that participate in the formation of FS decreases with increasing impurity potential. We find that the Néel temperature T(N) and the critical temperature T(c) maximum are determined by the FS volumes rather than the nominal extra electron concentration or the substituted atom concentration.

Evaluation of amphotericin B and micafungin combination against clinical isolates of Aspergillus species.

We aimed to evaluate the efficacy of a combination of amphotericin B (AMB) and micafungin (MCFG) against 25 clinical isolates of Aspergillus species in vitro. We examined fungal growth in the presence of these drugs using a checkerboard method with the tetrazolium salt: 2,3-bis (2- methoxy-4-nitro-5-sulphophenyl)-2H-tetrazolium-5-carboxyanilide inner salt (XTT) to determine the efficacy of an AMB/MCFG combination in inhibition of filamentous fungal growth, evaluated based on 50% reduction of metabolic activity. The fractional inhibitory concentration index showed that the drugs synergistically inhibited 36% of the isolates. Activity was judged as indifferent for 64% isolates; antagonistic interaction was not detected. The AMB/MCFG combination was more effective than AMB alone when sub-inhibitory concentrations of AMB were used. This report demonstrates the efficacy of AMB/MCFG combination for inhibiting the growth of Aspergillus species in vitro, warranting the extension of such studies to animal models.

Two-dimensional and three-dimensional Fermi surfaces of superconducting BaFe2(As(1-x)P(x))2 and their nesting properties revealed by angle-resolved photoemission spectroscopy.

We have studied the three-dimensional shapes of the Fermi surfaces (FSs) of BaFe(2)(As(1-x)P(x))(2) (x=0.38), where superconductivity is induced by isovalent P substitution and by angle-resolved photoemission spectroscopy. Moderately strong electron mass enhancement has been identified for both the electron and hole FSs. Among two observed hole FSs, the nearly two-dimensional one shows good nesting with the outer two-dimensional electron FS, but its orbital character is different from the outer electron FS. The three-dimensional hole FS shows poor nesting with the electron FSs. The present results suggest that the three dimensionality and the difference in the orbital character weaken FS nesting while partial nesting among the outer electron FSs of d(xy) character and/or that within the three-dimensional hole FS becomes dominant, which may lead to the nodal superconductivity.

In vitro combined effects of cefozopran/teicoplanin and cefozopran/vancomycin on methicillin-resistant Staphylococcus aureus.

We determined the in vitro effects of teicoplanin (TEIC) or vancomycin (VCM) added to cefozopran (CZOP) on 50 methicillin-resistant Staphylococcus aureus (MRSA) strains, using a modified checkerboard method with serial 1.25-fold dilutions, and assessed the time-kill curve. CZOP + TEIC was synergistic (fractional inhibitory concentration index < or = 0.5) against 98% and CZOP + VCM against 20% of strains. Both drug combinations were additive against the remaining strains. A comparison of the fractional bactericidal concentration indices for 32 strains showed synergistic bactericidal effects for CZOP + TEIC in 88%, and in 48% for CZOP +VCM, confirming that CZOP + TEIC is superior to CZOP + VCM. The time-kill curve confirms that the bactericidal potency of these drugs is increased through combined use with CZOP. These results suggest that treatment using TEIC or VCM with CZOP may be useful in treating MRSA infections, including polymicrobial infections and those involving Gram-negative rods.

Using isoproterenol stress echocardiography to predict the response to carvedilol in patients with dilated cardiomyopathy.

Trials have demonstrated that carvedilol can produce hemodynamic, symptomatic, and prognostic improvements in dilated cardiomyopathy (DCM), but some DCM patients have deteriorated after carvedilol, developing congestive heart failure. The present study investigated the use of isoproterenol (ISP) stress echocardiography to select those patients with DCM who would respond to carvedilol. ISP was infused intravenously in 22 patients with DCM and they were classified into 2 groups based on the left ventricular systolic response: good response to ISP [change in fractional shortening (FS) with ISP > 0.05, n=13] and poor response to ISP (change < or = 0.05, n=9). In the good response group, FS significantly increased from 0.12+/-0.04 to 0.17+/-0.08 (mean+/-SD, p<0.05) with carvedilol, and 7 patients improved symptomatically (New York Heart Association class). However, in the poor response group, no significant difference was observed between FS at baseline and that at the end of follow-up. Moreover, only 1 patient in the poor response group improved symptomatically. ISP stress echocardiography can assist in selecting patients with DCM who will respond positively to carvedilol.

[Informed consent for the use of the remaining portion of laboratory specimens for education, research, and quality control of laboratory tests].

The remaining portion of a laboratory specimen is usually used for education, research, and quality control of laboratory tests in hospitals, but informed consent has not been obtained because of the high volume of patients who undergo laboratory tests. However, patients must be informed in some manner. Therefore, we decided to inform patients that any remaining specimen would be used for various purposes by placing such a notice on walls in the central clinical laboratory and hospital lobby. We then obtained a signature on a dissent document, instead of a consent document, from any patient who dissented from such use. This indirect process for obtaining informed consent was approved by the ethics committee of Osaka University Medical School. The number of dissent documents sent in to the director was 54 of about 400,000 patients who underwent laboratory tests over the last 3 years, and there was no complaint against this "informed consent process".

Neonatal presentation of adult-onset type II citrullinemia.

Adult-onset type II citrullinemia (CTLN2) is characterized by a liver-specific argininosuccinate synthetase deficiency caused by a deficiency of the citrin protein encoded by the SLC25A13 gene. Until now, however, no SLC25A13 mutations have been reported in children with liver diseases. We described three infants who presented as neonates with intrahepatic cholestasis associated with hypermethioninemia or hypergalactosemia detected by neonatal mass screening. DNA analyses of SLC25A13 revealed that one patient was a compound heterozygote for the 851de14 and IVS11+IG-->A mutations and two patients (siblings) were homozygotes for the IVS11+lG-->A mutation. These results suggested that there may be a variety of liver diseases related to CTLN2 in children.

Impaired ability to secrete atrial natriuretic peptide in response to isoproterenol infusion in patients with dilated cardiomyopathy.

OBJECTIVES: The myocardium has 2 functions in vivo, that of pump and endocrine organ. Therefore, simultaneous examinations of cardiac systolic reserve and endocrine reserve are important in evaluating the activities of the myocardial cells. This study investigated the relationship between cardiac systolic reserve and secretion of atrial natriuretic peptide (ANP) in response to isoproterenol infusion in patients with dilated cardiomyopathy. METHODS: Isoproterenol was infused intravenously in 6 healthy individuals (control group) and 32 patients with dilated cardiomyopathy. The left ventricular systolic responses and plasma ANP concentrations were measured. RESULTS: Patients with dilated cardiomyopathy were classified into 2 groups: patients with a good response (change in fractional shortening > 7%, 17 patients) and those with a poor response (change in < or = 7%, 15 patients). There was no significant difference in end-diastolic dimension, fractional shortening, heart rate, or systolic blood pressure between the 2 groups of patients with dilated cardiomyopathy at rest. The resting plasma ANP concentration in the poor-response group (88.8 +/- 59.0 pg/ml) was significantly higher than that in the other 2 groups (good: 47.0 +/- 35.9 pg/ml, p < 0.05, control: 9.8 +/- 4.1 pg/ml, p < 0.01, respectively). The percentage change in ANP after isoproterenol infusion in the poor-response group (-7.1 +/- 16.7%) was significantly less than that in the other 2 groups (good: 12.6 +/- 27.3%, p < 0.05, control: 31.5 +/- 24.6%, p < 0.01, respectively). CONCLUSIONS: The resting plasma ANP concentration can be used to evaluate the cardiac systolic reserve in patients with dilated cardiomyopathy. Decreased myocardial systolic reserve is also associated with impaired ability to secrete ANP.

Pulmonary tissue volume measured by acetylene rebreathing under artificial ventilation.

OBJECTIVE: In order to evaluate the pulmonary congestive state of patients being mechanically ventilated, an acetylene rebreathing method was employed. Measurement of pulmonary tissue volume by the acetylene (C2H2) rebreathing method was performed in 15 patients under artificial ventilation including four congestive heart failure cases, one renal failure case, and 12 healthy controls. METHODOLOGY: The subjects rebreathed mixed gas containing 0.65% C2H2, 10% argon (Ar), and 60% oxygen (O2) from end-tidal level, and inspiratory and expiratory gas concentrations were measured by a mass spectrometer. Correction for system volume reduction during rebreathing due to gas exchange and C2H2 concentration fluctuation was performed, pulmonary tissue volume was calculated from the C2H2 and Ar concentration difference at the time zero intercept. Time zero was assumed to be the time at which C2H2 and Ar concentration started to differ. RESULTS: Pulmonary tissue volume per functional residual capacity and pulmonary tissue volume per pulmonary capillary blood flow for cases with congestive heart failure and renal failure cases were significantly higher than those for non-pulmonary congestion cases and normal controls. CONCLUSION: The measurement of pulmonary tissue volume by C2H2 rebreathing can be applied to the patients under artificial ventilation in order to quantitatively evaluate pulmonary congestion or edema.

Identification of two novel mutations in the SLC25A13 gene and detection of seven mutations in 102 patients with adult-onset type II citrullinemia.

Adult-onset type II citrullinemia (CTLN2) is characterized by a liver-specific deficiency of argininosuccinate synthetase (ASS) protein. We have recently identified the gene responsible for CTLN2, viz., SLC25A13, which encodes a calcium-binding mitochondrial carrier protein, designated citrin, and found five mutations of the SLC25A13 gene in CTLN2 patients. In the present study, we have identified two novel mutations, 1800ins1 and R605X, in SLC25A13 mRNA and the SLC25A13 gene. Diagnostic analysis for the seven mutations in 103 CTLN2 patients diagnosed by biochemical and enzymatic studies has revealed that 102 patients had one or two of the seven mutations and 93 patients were homozygotes or compound heterozygotes. These results indicate that CTLN2 is caused by an abnormality in the SLC25A13 gene, and that our criteria for CTLN2 before DNA diagnosis are correct. Five of 22 patients from consanguineous unions have been shown to be compound heterozygotes, suggesting a high frequency of the mutated genes. The frequency of homozygotes is calculated to be more than 1 in 20,000 from carrier detection (6 in 400 individuals tested) in the Japanese population. We have detected no cross-reactive immune materials in the liver of CTLN2 patients with any of the seven mutations by Western blot analysis with anti-human citrin antibody. From these findings, we hypothesize that CTLN2 is caused by a complete deletion of citrin, although the mechanism of ASS deficiency is still unknown.

Simultaneous continuous 13C, 12C analysis of expired gas in the 13C breath test.

The 13C breath test is a method of clarifying the metabolism of loaded substances by administering 13C-labelled materials and calculating the 13CO2 and 12CO2 ratio (13C/12C isotope ratio) in the expired gas. The materials are metabolized and expelled in the expired gas. Because simultaneous continuous measurement of 13CO2 and 12CO2 in expired gas has been difficult up to the present, respective expired gases, including dead space before and after administration, have been sampled to separate sampling bags and 13C/12C has been measured in the bags and changed fraction of 13C/12C after administration (delta) has been used to judge the metabolic process. This method is affected by the contamination of the dead space gas. In the present study, in order to exclude the dead space effect, simultaneous continuous analysis of 12CO2 and 13CO2 of expired gas identifying alveolar gas was applied to the 13C-urea breath test in addition to the conventional sampling bag method. Both isotope detectors were attached to a mass spectrometer. Fifty-six cases receiving stomach health check-ups for Helicobacter pylori were examined. Delta was calculated in the bag or in phase III of continuous gas measurement. Because the bag contains dead space, delta was reduced and sensitivity and specificity with reference to gastric fluoroscopy or Helicobacter pylori IgG antibody were reduced. Decreasing the dead space contamination is important in reducing the measurement error in the 13C breath test and simultaneous continuous measurement is a good tool for this purpose.

Impaired peripheral vasoconstriction in response to alpha-adrenergic stimulation in patients with idiopathic hypertrophic cardiomyopathy.

Exercise hypotension has been documented in patients with hypertrophic cardiomyopathy (HCM). Some investigators reported that this is due to an inadequate increase of systemic vascular resistance during or after exercise. The aim of this study was to investigate the pathogenesis of limb vascular response abnormalities in patients with idiopathic HCM. Thirteen patients with HCM and 9 healthy controls were administered an endothelium-dependent dilator (acetylcholine), a direct smooth muscle dilator (nitroglycerin), an alpha-adrenergic stimulator (phenylephrine), and a beta-adrenergic stimulator (isoproterenol) by intra-arterial infusion. Peripheral vascular resistance was assessed by forearm plethysmography at rest and during each infusion to obtain the percentage change in vascular resistance. Isoproterenol, acetylcholine and nitroglycerin produced dose-related vasodilatation with no significant differences between HCM patients and healthy controls. The percentage increase in vascular resistance was significantly less in HCM patients than in healthy controls after phenylephrine infusions of 0.5 microg/min (155+/-38% vs 195+/-47%, mean+/-SD, p<0.05) and 1.0 microg/min (174+/-49% vs 238+/-65%, p<0.05). Vasoconstriction mediated by alpha-adrenergic receptors appeared to be impaired in the peripheral vasculature of patients with HCM.

Improved fatigue resistance not associated with maximum oxygen consumption in creatine-depleted rats.

Effects of feeding of either creatine or its analog beta-guanidinopropionic acid (beta-GPA) on endurance work capacity and oxygen consumption were studied in rats. Resting high-energy phosphate contents in hindlimb muscles were lower in the beta-GPA group and higher in the creatine group than in controls. The glycogen contents in resting hindlimb muscles of rats fed beta-GPA were significantly higher than those in controls. The endurance run and swimming times to exhaustion were significantly greater (32-70%) in the beta-GPA group than in the control and creatine groups. However, there were no beneficial effects on the maximum oxygen consumption (VO2max) and oxygen transport capacity of blood by the feeding of beta-GPA. None of these parameters were significantly influenced by creatine supply. Both maximum exercise time and VO2max in the beta-GPA group were not changed by normalization of glycogen levels. The activities of mitochondrial enzymes in skeletal muscles were higher in the beta-GPA group than in the controls. Thus endurance capacity is improved if the respiratory capacity of muscles is increased, even when the contents of high-energy phosphates in muscles are lower. Increased endurance capacity was not directly associated with the elevated levels of muscle glycogen, oxygen transport capacity of blood, or VO2max.

[Use of acetylene rebreathing to measure pulmonary tissue volume in patients undergoing hemodialysis].

Acetylene rebreathing was used to measure pulmonary tissue volume in 10 normal subjects and in 15 patients undergoing hemodialysis. A mixture containing 0.65% acetylene and 10% argon was rebreathed from the end-tidal level, and gas concentrations were measured with a mass spectrometer. Pulmonary tissue volume was computed from the difference between the argon equilibrium concentration and the corrected acetylene concentration, under the assumption that FAr was constant. Measured tissue volumes per unit lung volume (at functional residual capacity) in the normal subjects, before hemodialysis, and after hemodialysis were 0.204 +/- 0.042, 0.334 +/- 0.100, and 0.282 +/- 0.074, respectively. Tissues volumes per unit lung volume were significantly higher in the patients than in the normal subjects, even after hemodialysis. Tissues volumes per unit of lung volume decreased significantly during hemodialysis. Pulmonary blood flows per unit of body surface area of normal subjects, before hemodialysis and after hemodialysis were 3.004 +/- 0.791, 2.790 +/- 1.007, and 2.399 +/- 0.781 (l/min/m2), respectively. These volumes did not differ significantly between normal subjects and patients, and they decreased significantly during hemodialysis. Measured tissue volumes per unit of pulmonary blood flow for normal subjects, before hemodialysis, and after hemodialysis were 0.119 +/- 0.034, 0.167 +/- 0.024, and 0.166 +/- 0.030 (1/1/min), respectively. The values in the patients did not change during hemodialysis, but they were significantly higher than the volumes in the normal subjects.

Development of photosynthesis and respiration measurement system using mass spectrometry.

A closed gas-exchange system was developed to measure gross photosynthesis and respiration discriminately and simultaneously. The system developed in this study included a high performance mass spectral analyzer for gas measurements. The gas-exchange system consisted of a 3L assimilation leaf chamber, a 1L flexible metallic bag, gas supply apparatus, and a lighting system. The lights were turned on and gas measurements were started after the initial 12CO2 concentration level was increased to 500 ppm. The 13CO2 gas was added to the chamber 10 min after the start of the light period. The lights were turned off 15 min after the addition of 13CO2. The 12CO2 and 13CO2 concentrations in the chamber during the light and dark periods were measured for pothos and maize leaves. The 13CO2 absorption rate by the leaves was larger than that for 12CO2 during the light period. It was assumed that the 13CO2 absorbed by photosynthesis was not evoluted by respiration during the first 25 min from the start of the light period. Based on this assumption, gross photosynthetic rate and respiration rate were estimated by calculating the difference in uptake rates of 12CO2 and 13CO2 during the light period.

Discriminating and continuous measurement of photosynthesis and respiration by monitoring 13CO2 and 12CO2 as tracers.

The simultaneous and discriminative measurement of the photosynthesis and the respiration of the plant was attained by simultaneous monitoring of 13CO2 and 12CO2 by artificial control of 13CO2 abundance of ambient air. The principle of the measurement is based on the following physiological processes. 6CO2 + 12H2O --> C6H12O6 + 6O2 + 6H2O, 6(13C)O2 + 12H2O --> (13C6)H12O6 + 6O2 + 6H2O, 6CO2 + 12H2(18O) --> C6H12O6 + 6(18O)18O + 6H20. Assuming that respiratory consumption of the new born carbon substrate fixed by photosynthesis is negligible during the measurement, the photosynthetic CO2 consumption VPCO2 and the respiratory CO2 production VRCO2 are measured according to the estimation (1) or (2), (1) for closed method, VPCO2 = k(V0 - V t)¿ F13CO2 + (F12CO2/F13CO2)F13CO2 ¿, VRCO2 = k(V0 - V t)¿ F12CO2 - (F12CO2/F13CO2)F13CO2 ¿, (2) for open method, VPCO2 = kVE ¿ (FI13CO2 - FE13CO2) + (F12CO2/F13CO2)(FI13CO2 - FE13CO2) ¿, VRCO2 = kVE ¿ (FI12CO2 - FE12CO2) - (F12CO2/F13CO2)(FI13CO2 - FE13CO2) ¿ where V0 is initial volume of growth chamber including attached flexible bag, FICO2 is the inlet or initial gas concentration of CO2 and FECO2 is the ambient gas concentration of CO2 in the chamber, V and VE are the sampling rate of mass spectrometer and the ventilation rate of the growth chamber respectively, k is the STPD conversion factor = ¿273(PB-PH2O)/760(273+tE)¿, tE(degrees C) is the ambient gas temperature. In the closed method, the gas container of the growth chamber is circulated, resulting FECO2 is varied according to the balance of consumption and production of CO2, while in the open method VE is controlled to keep FECO2 at a constant value. Both (1) and (2) methods were examined and evaluated on the measurements of komatsuna and maize.