Successful emergency aortic valve replacement following percutaneous cardiopulmonary support for the patient with aortic stenosis and cardiac arrest

We present a 57-year-old woman with severe aortic stenosis. She was diagnosed with acute myocardial infarction by electrocardiography and the detection of elevated creatine phosphokinase in another hospital. Soon after transfer to our hospital, this patient developed cardiac arrest. Percutaneous cardiopulmonary support (PCPS) was established, and subsequently performed coronary angiography revealed normal coronary arteries. However echocardiography revealed severe aortic stenosis. Emergency aortic valve replacement (AVR) was performed, and the patient was discharged from hospital 30 days after surgery in good health. Prompt establishment of PCPS maintained her systemic circulation, and allowed us to conduct investigations for diagnosis. In patients with critical aortic stenosis, emergency AVR should be performed as early as possible following diagnosis.     

Clustering of several cardiovascular risk factors affects tissue characteristics of the carotid artery

Integrated backscatter (IBS) signal obtained by extracranial ultrasound examination of the carotid artery can be used to evaluate the tissue characteristics of arterial plaque. To examine whether clustering of several cardiovascular risk factors, metabolic syndrome (MetS), affects the tissue characteristics of the carotid artery, we measured Calibrated-IBS values of the intima–media complex in the carotid artery for 142 patients (61.6 ± 9.5 years old) with at least one component of MetS.

Calibrated-IBS values were inversely correlated with the number of MetS components (r = −0.224, p = 0.0073). Furthermore, the number of MetS components was an independent risk factor for a low Calibrated-IBS. The subjects with coronary heart disease (CHD) (n = 20) showed significantly lower Calibrated-IBS than those without it (n = 122) (−17.8 ± 5.1 vs. −21.7 ± 5.5 dB, p = 0.0020), and the logistic regression analysis showed that the presence of CHD was associated with Calibrated-IBS (RR = 0.898, 95%CI: 0.811–0.994, p = 0.0374).

These results suggest that clustering of the cardiovascular risk factors affects the Calibrated-IBS, an acoustic parameter of tissue characteristics of the intima–media complex in the carotid artery.     

Age-dependent difference in factors affecting choice of system for self-monitoring of blood glucose

To clarify factors determining the preference for a self-monitoring blood glucose (SMBG) system in patients with diabetes mellitus. A total of 52 Japanese inpatients with diabetes mellitus were recruited into a single-center trial. After the patients got used to one SMBG system, the SMBG system was substituted with another one of the three, and the subjects were given questionnaires. The following parameters were identified as independent factors associated with the preference of SMBG: display (P<0.0001), operation for inserting strips (P=0.0004), and lancing-device operation (P<0.05). When the subjects were divided according to age, the independent variables associated with overall preference in the older group (>or=60 years) were display (P=0.001) and procedure for detaching a used needle (P=0.01), whereas those in the younger group (age<60 years) were operation of the lancing device (P<0.0001), operation to apply blood to strip (P=0.001), and amount of blood (P=0.04). These data suggest that in elderly patients with diabetes, display and detachment of the needle are important factors affecting the choice of SMBG system, whereas younger subjects give weight to skin puncture-related issues in choosing an SMBG system.     

Comparative analysis of cytolethal distending toxin (cdt) genes among Campylobacter jejuni, C. coli and C. fetus strains

The cytolethal distending toxin (cdt) gene clusters of Campylobacter coli strain Co1-243 and C. fetus strain Col-187 were cloned and sequenced to understand the importance of Cdt as a virulence factor. The cdt genes of C. coli and C. fetus consist of three closely linked genes termed cdtA, cdtB, cdtC whose sizes are 774, 801, and 570 bp, and 702, 798, and 546 bp, respectively. The homologies of each subunit of cdt genes between C. jejuni and C. coli, C. jejuni and C. fetus, or C. coli and C. fetus are 59.6%, 40.3%, or 46.5% for cdtA, 70.2%, 62.4%, or 61.3% for cdtB, 61.3%, 52.3%, or 50.1% for cdtC, respectively. Colony hybridization assay revealed that the genes homologous to the cdtABC gene were distributed in all 27, 19, 20 strains of C. jejuni, C. coli, and C. fetus, respectively, isolated from patients and animals in species-specific manner. Furthermore, nucleotide sequence of the cdt operon, including flanking region, of 10 strains of each species indicated that though the size of the cdtB gene was conserved in each species, those of cdtA and cdtC genes varied particularly among C. coli strains. Amino acid residues demonstrated to be important for toxin activity in CdtB, corresponding to H152, D185, D222, D258, H259 in Cj-CdtB, were also conserved in Cc-CdtB and Cf-CdtB. The cdt gene cluster was located in different sites among different species but in the same site of genomes of the same species. Cdt activity produced by C. jejuni and C. fetus varied among strains, however, any C. coli strains exhibited Cdt activity on HeLa cells. These data indicate that the cdt gene may have a potential for virulence factor at least in C. jejuni and C. fetus.     

An epidemiological study of the susceptibility and frequency of multiple-drug-resistant strains of Pseudomonas aeruginosa isolated at medical institutes nationwide in Japan

The susceptibility of 3233 strains of Pseudomonas aeruginosa, isolated primarily in 2001, as agents of infection at 37 medical institutes with various specialties in seven regions of Japan (ranging from Hokkaido to Kyushu/Okinawa), to 18 antipseudomonal agents known to be active against P. aeruginosa was evaluated, in accordance with the National Committee for Clinical Laboratory Standards (NCCLS) guidelines. Of the 18 antipseudomonal agents, including some combinations of -lactamase inhibitors and antibacterial agents, ciprofloxacin had the lowest minimum inhibitory concentration (MIC)₅₀ (0.25µg/ml) against P. aeruginosa, followed by meropenem, with an MIC₅₀ of 0.5µg/ml. The MIC₅₀ of 7 of the examined antibacterial agents (ceftazidime, cefozopran, imipenem, biapenem, gentamicin, tobramycin, and levofloxacin) was between 1 and 2µg/ml. Among the antipseudomonal agents tested, tobramycin showed the lowest MIC₉₀ (2µg/ml), which was not significantly different from its MIC₅₀ (1µg/ml). The MIC₉₀ of the other antibacterial agents examined ranged from 8 to 64µg/ml and more. The susceptibility of the 3233 strains to the 12 antibacterial agents covered by the NCCLS guidelines was determined according to the standard method of the NCCLS guidelines. The frequency of strains resistant to meropenem, gentamicin, or tobramycin was relatively low (7.5%–8.3%). The frequency of strains showing intermediate to severe resistance to tobramycin was particularly low (8.0%). The frequency of strains resistant to aztreonam, imipenem, or levofloxacin was 16.7%–19.0%, about twice as high as the frequency of strains resistant to tobramycin. The susceptibility pattern of the 3233 strains (isolated from seven regions of Japan) to five antibacterial agents (ceftazidime, piperacillin, imipenem, gentamicin, and ciprofloxacin) was evaluated in relation to the regions from which they were isolated. The MIC₅₀ values of these antibacterial agents did not differ significantly among the regions. However, the MIC₉₀ values of ceftazidime and gentamicin were higher for strains isolated from the Kansai region than for strains isolated from other regions. The MIC₉₀ of ciprofloxacin was higher for strains isolated from the Tohoku, Kansai, and Kyushu/Okinawa regions than for strains isolated from other regions. Of the 3233 strains, 89 were classified as multiple-drug-resistant (imipenem, gentamicin, and ciprofloxacin) strains. Of these 89 strains, 42 were isolated from urine, 17 from sputum or pharyngeal mucus, 13 from pus, 8 from blood, 1 from cerebrospinal fluid, and 8 from other specimens. The frequency of multiple-drug-resistant strains was higher among strains isolated from the Tohoku and Kansai regions than in strains isolated from other regions.     

Resistance to gram-negative organisms due to high-level expression of plasmid-encoded ampC β-lactamase blaCMY-4 promoted by insertion sequence ISEcp1

A Klebsiella pneumoniae strain, KU6500, which showed resistance to extended-spectrum β-lactams and produced the plasmid-encoded AmpC β-lactamase CMY-4, was identified from clinical isolates in Japan. The aim of this study was to identify the mechanism of the high-level expression of bla _CMY-4. Sequence analysis indicated that the promoter element of Citrobacter freundii was conserved, but the insertion sequence ISEcp1 coding with the putative promoter element, was inserted into the AmpR binding site. We determined the influence of the promoter on bla _CMY-4 expression and β-lactam resistance. Two recombinant plasmids containing the entire bla _CMY-4 gene, with or without the ISEcp1-mediated promoter sequences, were constructed and named pMWampC and pMWISEcp1, respectively. Escherichia coli DH5α (pMWISEcp1) was resistant to almost all β-lactams tested and E. coli DH5α (pMWampC) was susceptible to all, except for cephalothin. In addition, the activity of each promoter was measured by subcloning the element into a promoterless luciferase plasmid pGL3-Basic vector. The expression of the putative promoter of ISEcp1 was 18.9-fold higher than that of C. freundii. These results suggest that the putative promoter element of ISEcp1 is necessary for the high-level expression of bla _CMY-4 to confer resistance to extended-spectrum cephalosporins.