Distribution of insertion sequence-like element IS1272 and its position relative to methicillin resistance genes in clinically important Staphylococci

The distribution of insertion sequence-like element IS1272 was analyzed for clinical isolates of Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus. In each of the staphylococcal species, IS1272 was detected in both methicillin-resistant (MR) and methicillin-susceptible strains of different genetic types. In MR isolates, IS1272 was generally located downstream of the truncated mecR1 gene (DeltamecR1), with an identical junction sequence occurring between DeltamecR1 and IS1272, although insertion of an additional gene sequence in the junction sequence was detected in one S. epidermidis isolate. These findings suggest that the mec element with the rearranged form of mecR1 (DeltamecR1-IS1272) has been transmitted to multiple clones of staphylococci.

Heterocyclic amine mixture carcinogenesis and its enhancement by caffeine in F344 rats

In order to elucidate whether mixed exposure to environmental carcinogens and caffeine increases the risk of cancer induction, we investigated the relationship between preneoplastic lesion development in the liver and colon and drug metabolizing enzyme induction and DNA adduct formation, in rats treated with a mixture of heterocyclic amines (HCAs) and caffeine. In Experiment 1, male F344 rats were administered 3 different HCAs, the food carcinogens, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), alone or in combinations of 2 or 3 at 50 ppm in the diet for 16 weeks. The numbers of hepatic glutathione-S-transferase P form positive (GST-P+) foci and colonic aberrant crypt foci (ACF) were greater in the IQ + MeIQx group than expected from simple summation and increased levels of HCA-DNA adducts were noted. However, no summation was obtained when combined with PhIP, which rather caused inhibition. In Experiment 2, the effects of concurrent caffeine administration on the PhIP carcinogenicity were assessed. Caffeine at 1000 and 500 ppm in the drinking water for 2 weeks significantly increased levels of CYP1A2. Ten weeks concurrent administration of caffeine (1000 ppm) and PhIP (400 ppm) resulted in significant increase of colon ACFs and CYP1A2 expression. Thus, concurrent administration of IQ and MeIQx caused elevation of their carcinogenicity but other mixtures with PhIP did not enhance carcinogenicity. However, a non-carcinogen, caffeine, enhanced PhIP colon carcinogenesis, possibly due to induction of CYP1A2.

[A case of post-infectious wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) syndrome]

The patient is a 72-year-old man who had tonsillitis and underwent incision on March 6, 1998. He complained headache and nausea from March 10 and double vision from March 12. He was admitted to our hospital on March 14. Neurological examination on March 18 revealed bilateral internuclear ophthalmoplegia with exotropia (WEBINO), bilateral ptosis and disturbance of convergence. Lumbar puncture revealed moderately elevated protein (46 mg/dl) with normal pressure and cells. The T2-weighted images of head MRI showed multiple high intensity lesions in anterior commissure and right pons. After he was treated with methylprednisolone, his headache and ptosis disappeared. The lesion in anterior commissure on MRI disappeared also. But WEBINO remained at the time of discharge. WEBINO syndrome is caused by lesion of pons and midbrain. The most common cause of bilateral internuclear ophthalmoplegia is multiple sclerosis in the European and American countries, but the frequency of vascular origin is higher in Japan than in the European and American countries. All the cases of WEBINO syndrome reported in Japan are vascular origin. This is the first case of WEBINO syndrome not of vascular origin.

Heterozygous p53-deficient mice are not susceptible to 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) carcinogenicity

2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) is a very potent mutagen which induces tumors in the liver, lung and hematopoietic system of CDF1 mice and the liver, Zymbal gland and skin in F344 rats. The recent development of transgenic knockout mice allows their introduction for sensitive screening of environmental carcinogens due to the rapid development of tumors. P53 gene deficient mice (p53-/-) were found to spontaneously develop malignant lymphoma and hemangiosarcoma, whereas heterozygotes (p53+/-) mice display a high incidence of tumors of the urinary bladder when treated with N-butyl-N-(4-hydroxybutyl)nitrosamine. In the present study, to determine whether p53 gene knockout mice can be utilized in a short-term assay model for the screening of heterocyclic amines (HCAs), the effects of MeIQx, as a representative compound, at low doses were examined. Male and female p53+/- mice and wild type littermates (p53+/+) were continuously given diets containing 0, 0.1, 1, 10 and 100 ppm MeIQx for 1 year. No significant difference in tumor induction was observed other than an increase in liver adenomas in males receiving 10 ppm MeIQx treatment. The results indicate that p53+/- mice have no practical advantages for use in short-term carcinogenicity tests of HCAs.

Three point mutations of human butyrylcholinesterase in a Japanese family and the alterations of three-dimensional structure

Three different mutations at codons 330 (TTA to ATA), 365 (GGA to AGA) and 515 (CGT to TGT) of human butyrylcholinesterase (hBChE) were identified in a Japanese family. We correlated alterations in in the patient's hBChE activity with possible structural alterations in the three-dimensional structure of hBChE caused by the point mutations. This study was performed using the published computer-generated three-dimensional structure of hBChE based on the structure of acetylcholinesterase. The amino acid substitution at L330I was adjacent to hydrophobic residues that form the channel domain of the active center. This side chain faced the side opposite the active center. The amino acid substitution at G365R was located at the position most remote from the active center, and this substitution site was exposed to the surface of the BChE protein. Alpha-helical structure was present to the active center, and the guanidyl residue of native Arg 515 was hydrogen-bonded to the carboxyl group of Asp 395 in the alpha-helix. These point mutations may cause steric effects on the present patient's hBChE activity. This is the first report of three-dimensional structural analysis performed on the L330I, G365R, and R515C mutations of hBChE.

Analysis of genomic diversity within the Xr-region of the protein A gene in clinical isolates of Staphylococcus aureus

Protein A of Staphylococcus aureus contains a polymorphic Xr-region characterized by a tandem repeat of eight amino acid units. In this study, the diversity of genes encoding the repeat regions and their relatedness among S. aureus strains was analyzed. Ten different protein-A types characterized by repeat numbers 4-13 were identified in a total of 293 clinical isolates. The protein-A type with 10 repeat units (10 repeats) in the Xr-region was most frequently detected in methicillin-resistant S. aureus, whereas the majority of methicillin-susceptible strains were distributed almost evenly into protein-A types with 7-11 repeats. Strains that belonged to a single coagulase type were classified into multiple protein-A types, e.g. strains with the common coagulase types II and VII were differentiated into 7 and 8 protein-A types, respectively. Nucleotide sequence analysis of the Xr-region of 42 representative strains revealed the presence of 37 different genotypes (spa types), which were constituted by a combination of several of 24 different repeat unit genotypes. Based on the similarity in arrangement of repeat unit genotypes, 34 strains with different repeat numbers were classified into 5 genetic clusters (C1-C5). The clusters C1, C2 and C3 consisted exclusively of strains with identical coagulase types II, III, and IV, respectively. These findings suggested that the protein-A gene of S. aureus has evolved from a common ancestral clone in individual clusters independently.

[Survey of the sensitivities of clinical isolates to antibacterial agents (annual report)]

Research groups were formed in 21 institutions nationwide to investigate carbapenem resistance. The activities of various antibacterial agents, principally carbapenems, were tested against clinical isolates collected from these institutions. The broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of 17 antibacterial agents for 1,241 strains of 11 bacterial species isolated at all institutions between October and December 1996. The results were as follows: Carbapenems exhibited strong antibacterial activities against MSSA and Streptococcus pneumoniae and showed low activities against MRSA. Their activities against Enterococcus faecalis were comparable to that of ampicillin and piperacillin. The carbapenems showed high activities against Haemophilis influenzae, Escherichia coli, Klebsiella pneumoniae. Enterobacter cloacae. Serratia marcescens and Bacteroides fragilis group. Their activities were greater than that exhibited by other beta-lactam antibacterial agents, but some resistant strains of Serratia marcescens were detected. The antibacterial activity of carbapenems against Pseudomonas aeruginosa was comparable to that of CAZ, and there were some resistant strains.

Simultaneous amplification of Bordetella repeated insertion sequences and toxin promoter region gene by polymerase chain reaction

A polymerase chain reaction was devised to simultaneously detect repeated insertion sequences and the pertussis toxin promoter gene for the diagnostic identification of Bordetella pertussis, B. parapertussis, and B. bronchiseptica. The sensitivity of this method was sufficient to detect one B. pertussis organism using the following cycles and temperatures: 95 degrees C for 15 min, followed by 32 amplification cycles (1 min at 95 degrees C, 1 min at 66 degrees C, 1 min at 72 degrees C), and finally 5 min at 72 degrees C. Using the primers as a combined set did not affect sensitivity, but required an increased temperature for optimal annealing compared with a single-sequence assay. As nasopharyngeal aspirate and swab materials sometimes contain hemoglobin, we also tested the inhibitory effect of hemoglobin on this assay, which was inhibited completely when using DNA extracts from samples containing hemoglobin at a final concentration >0.015 g/L: this inhibition was reversed by addition of bovine serum albumin to the buffer. Our assay shows promising sensitivity and specificity for clinical use.

Study of a patient referral system in the Republic of Honduras

The first nationwide study on a patient referral system was conducted in Honduras. It covered all 25 public hospitals (six National, five Regional and 14 Area Hospitals) and 24 major health centres. Based on 46,739 reviews of patient records, 226 'received referral' and 1072 'sent referral' cases were analyzed by age and sex of the patient, diagnosis on referral, institution from or to which the case was referred, use of proper referral form, and reception of reply for referrals. At the same time, the study team supervised the function of the registry and management of patient records at each institution. The average referral rate by the level of health facility was 15.8% at National, 4.0% at Regional, 2.8% at Area Hospitals, and 0.8% at health centres. The referral rate was observed to be higher when institutional managers emphasized the importance of the referral system. Only 1.4% of referrals received a reply from upper level institutions. The most common cases for referral were neurological at National, obstetric at Regional and respiratory cases at Area Hospitals. The use rate of the standard referral form was 70 to 80% at hospitals and 60% at health centres. There was no norm to duplicate referral letters for record keeping. The patient referral system has not developed satisfactorily in Honduras. The main problems were: 1) low referral rate at all levels of institution, 2) evident by-pass phenomenon at intermediate hospitals, 3) inadequate health information system for patient referral, and 4) misunderstanding of the terminology of referral by health personnel. The following recommendations were made: guarantee of essential health services at peripheral institutions, development of an effective information system for patient referral, facilitation of frequent reply for referrals, elaboration of referral case discussion between institutions, patient education on proper use of health facilities, and restructuring the health service network in the two major cities.

Spatial and temporal filtering of a 10-W Nd:YAG laser with a Fabry--Perot ring-cavity premode cleaner

We report on the use of a fixed-spacer Fabry-Perot ring cavity to filter spatially and temporally a 10-W laser-diode-pumped Nd:YAG master-oscillator power amplifier. The spatial filtering leads to a 7.6-W TEM (00) beam with 0.1% higher-order transverse mode content. The temporal filtering reduces the relative power fluctuations at 10 MHz to 2.8x10(-9)/ radicalHz, which is 1 dB above the shot-noise limit for 50 mA of detected photocurrent.

Molecular discrimination of enterotoxin C subtype in clinical isolates of Staphylococcus aureus

The subtype of staphylococcal enterotoxin C (SEC) of 33 S. aureus clinical isolates was determined by polymerase chain reaction and direct DNA sequencing of a portion of the SEC gene encoding the SEC subtype-specific region. With the exception of a single strain with the SEC2 gene, all other strains showing different biologic and genetic properties were proved to possess the SEC3 gene.

[Survey of the sensitivities of clinical isolates to antibacterial agents (annual report)]

Research groups were formed in 21 institutions nationwide to investigate carbapenem resistance. The activities of various antibacterial agents, principally carbapenems were tested against clinical isolates collected from these institutions. The broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of 17 antibacterial agents for 1,282 strains of 11 bacterial species isolated at all institutions between October and December 1995. The results were as follows: 1. Carbapenems exhibited strong antibacterial activities against MSSA and Streptococcus pneumoniae. Their activities against Enterococcus faecalis were comparable to that of ABPC. Carbapenems showed low activities against MRSA. 2. OFLX exhibited the greatest antibacterial activity against Haemophilus influenzae, followed by MEPM. The antibacterial activities of the other carbapenems were comparable to those of FMOX and CTM. 3. The carbapenems showed high activities against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Bacteroides fragilis group. Their activities were greater than that exhibited by other beta-lactam antibacterial agents. The carbapenems also exhibited greater antibacterial activities against Serratia marcescens than the other beta-lactam antibacterial agents, but some resistant strains were detected. 4. The antibacterial activities of carbapenems against Pseudomonas aeruginosa were comparable to those of CAZ, AZT, AMK.

Nonradioisotopic telomeric repeat amplification protocol (TRAP) using digoxigenin labeled probe

We have attempted to detect telomerase activity by Southern blot analysis using a digoxigenin labeled probe (5'-(CCCTTA)6CCCTAA-3') Telomerase activity was detected in all cancer cell lines that were tested, and:the lower limit for detection was 10(3) cells. Although telomerase activity was detected in colon cancer tissues, it was not found in adenoma or normal tissues. Telomerase activity was completely abrogated by heat and RNase treatment of the CHAPS extract. Our results demonstrate that this nonradioisotopic assay is safe and reliable for detecting telomerase activity in cancer cell lines and biopsy samples.

[Doping test for racehorses in Japan]

The doping test method used in a horse race requires the accurate detection of a wide variety of drugs and metabolites as well as the rapidity in order to examine a large number of samples within a limited time. For this purpose, the routine method consists of a preliminary screening and a confirmatory test. In this paper, a historical review for the development of the doping test method in Japan is described. The metabolism and pharmacology of drugs in horses are also discussed.

On the validity of the Ego-Grasping Orientation Scale

The validity of the Ego-Grasping Orientation Scale (EGO) was tested. Theoretically, the EGO is a measure of mental health based on Taoistic (i.e., Ancient Chinese) philosophy. A total of 68 research participants completed the EGO along with measures of Eastern/Western orientation, self-esteem, assertiveness, desire for control, social interest, anxiety, and depression. Results indicated that the EGO may be a better measure of Taoistic mental health when combined with scales of Eastern/Western orientation, depression, self-esteem, and social interest.

Bidirectional regulation of telomerase activity in a subline derived from human lung adenocarcinoma

Telomerase is active in germline cells and tumor cells, but is either not expressed or is repressed in a majority of somatic cells. The regulation mechanism of telomerase activity has lately drawn considerable attention for the possible use of telomerase inhibitors for anti-cancer therapy. We analyzed the regulation mechanism of telomerase activity in the human lung adenocarcinoma cell line A549 and its subline A5DC7 which shows impaired tumor phenotypes. Although A549 and A5DC7 cells have similar growth potentials, when cultured in medium supplemented with 5% fetal bovine serum A5DC7 cells demonstrated a remarkable negative regulation of telomerase activity and telomere shortening. After the long-term culture, A5DC7 cells showed a large senescent cell-like morphology, arrested growth at the 106 population doubling level and entered senescence which was demonstrated by expression of the beta-galactosidase senescence marker. When the serum concentration was raised from 5% to 10% for the senescent A5DC7 cells, telomerase reactivation and telomere lengthening occurred as well as resumption of proliferation. These results demonstrate that the growth arrest seen in senescent A5DC7 cells is reversible and that telomerase activity is also bi-directionally regulated in A5DC7 cells, an event which could not be observed in normal senescent cells. This indicates that stringent telomerase repression and complete growth arrest concomitant with cellular senescence is collapsed in senescent A5DC7 cells in response to exogenous signals. Our study suggests that cellular senescence progresses and/or is regulated at multiple levels.

[Survey of sensitivities of clinical isolates to antibacterial agents (annual report)]

Research groups were formed in 20 institutions nationwide to investigate carbapenem resistance of clinical isolates. Activities of various antibacterial agents, principally carbapenems, were tested against clinical isolates collected from these institutions. The broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of 17 antibacterial agents for 1,326 strains of 11 bacterial species isolated at the institutions between October and December 1994. The results are as follows: 1. Carbapenems exhibited strong antibacterial activities against MSSA and Streptococcus pneumoniae. Their activities against Enterococcus faecalis were comparable to that of ABPC. Carbapenems showed low activities against MRSA. 2. OFLX exhibited the greatest antibacterial activity against Haemophilus influenzae, followed by MEPM. Antibacterial activities of the other carbapenems were comparable to those of FMOX, CTM, and ABPC. 3. The carbapenems showed high activities against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Bacteroides fragilis group. Their activities were greater than those exhibited by other beta-lactam antibacterial agents. The carbapenems also exhibited stronger antibacterial activities against Serratia marcescens than the other beta-lactam antibacterial agents, but some resistant strains were detected. 4. The antibacterial activities of carbapenems against Pseudomonas aeruginosa were comparable to those of CAZ, AZT, AMK.

Decreased connexin32 and a characteristic enzyme phenotype in clofibrate-induced preneoplastic lesions not shared with spontaneously occurring lesions in the rat liver

Two different types of focal preneoplastic lesions, tentatively named Type I and II lesions, were recognized in the liver of rats chronically treated with clofibrate for 104 weeks. Type I lesions were characterized by mostly negative glucose-6-phosphate dehydrogenase (G6PD) activity (6 out of 10, 60%) and positive expression of succinate dehydrogenase (10 out of 10, 100%), in addition to the previously documented complete lack of expression of glutathione S-transferase, placental form (GST-P) and gamma-glutamyl transpeptidase (GGT). Furthermore, most importantly, Type I lesions exhibited a clear decrease in immunohistochemically demonstrated connexin32 (Cx32) spot counts on their hepatocyte membranes, similarly to nitrosamine-induced lesions. In contrast, Type II lesions, mostly small in size and positively expressing GST-P and/or GGT and G6PD, similarly to their previously reported nitrosamine-induced counterparts, did not exhibit a significant decrease in Cx32 count. In addition, spontaneously occurring lesions, again sharing the same enzyme phenotype, did not show a decrease in Cx32. The results indicate that: (i) a clear distinction between the two lesions, with Type I being involved in clofibrate-induced tumors and Type II being more likely to be spontaneous in nature; (ii) a decrease in Cx32 is closely linked to lesion development and possibly stage of progression, irrespective of the enzyme phenotype and the applied carcinogen; (iii) the unaltered condition of Cx32 may suggest a slow growing or non-progressive nature.

Genomic diversity of mec regulator genes in methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis

Low-affinity penicillin-binding protein PBP-2a encoded by mecA is closely related to methicillin resistance in staphylococci, and expression of PBP-2a is controlled by regulator elements encoded by mecR1 and mecI which are located adjacent to mecA on the chromosome. Deletion or mutation which occurred in mec regulator gene is considered to be associated with constitutive production of PBP-2a. The distribution of the mec regulator genes in 176 strains of Staphylococcus aureus and 33 strains of S. epidermidis isolated from a single hospital was studied by polymerase chain reaction amplification. Most clinical isolates of methicillin-resistant S. aureus (MRSA) (94.3%) and S. epidermidis (MRSE) (83.9%) possessed both mecI and mecR1 genes (type I), whereas no mec regulator genes were detected in mecA-negative isolates. In contrast, 7 MRSA and 5 MRSE isolates were found to have incomplete regulator genes, and they were classified into three groups; strains which lacked only mecI gene (type II), strains which lacked mecI and 3'-end of mecR1 gene (type III), and strains which lacked both regulator genes (type IV). Analysis of mecI gene from all the strains having mecI by restriction fragment length polymorphism after Mse I digestion indicated that three MRSA strains possessed one of the known point mutations identified previously. These findings indicated the predominance of a single type of MRSA possessing both mecI and mecR1 in the study period and also suggested a high genomic diversity in mec regulator region of staphylococci.

[Evaluation of differential media in Helicobacter pylori culture]

Culture is one of the important methods for detecting Helicobacter pylori(Hp). Culture method is generally lower sensitive in comparison with other Hp detection methods. However, culture is necessary for determination of MIC and analysis of bacteriological characteristics. Several culture media are now commercially available for Hp. In this study, we compared commercial media with our original medium. Original medium for Hp culture was most sensitive and showed no false-positive results compared with other commercial media.

Evaluation of nitric oxide formation from nitrates in pig coronary arteries

To clarify the hypothesis that organic nitrates are converted to nitric oxide (NO) via nitrite ion (NO2-) by glutathione S-transferase, the metabolic conversion of four nitrates was examined in pig coronary arteries and compared with that in rat liver. Nitrates caused the relaxation of the artery muscles with the order of nitroglycerin > isosorbide dinitrate > nicorandil > or = nipradilol, whereas the order of NO formation in the arteries was nitroglycerin > isosorbide dinitrate > nipradilol > nicorandil. The same order of NO formation from the nitrates was also observed in liver cytosol. Nicorandil may cause more relaxation than nipradilol by both NO releasing and other (unknown) actions. Although the order of the potency in NO2- formation from the nitrates in liver cytosol was the same as that seen in NO formation, NO2- was not detected in pig coronary arteries. Thus NO2- formation from the nitrates correlated with NO formation in liver cytosol but not in pig arteries. When nonenzymatic and enzymatic NO formations from nitroglycerin were examined in the arteries, the enzymatic NO formation, which was not inhibited by glutathione S-transferase inhibitors, was 13% of the total NO. These results indicate that in pig coronary arteries, nitrates release NO mostly through a nonenzymatic manner, although there is a slight amount of enzymatically produced NO, and glutathione S-transferase may not contribute to the enzymatic NO formation.

Decreased levels of 2-amino-3-methylimidazo[4,5-f]quinoline-DNA adducts in rats treated with beta-carotene, alpha-tocopherol and freeze-dried aloe

To assess mechanisms of chemoprevention of hepatocarcinogenesis by trans-beta-carotene (beta-C), DL-alpha-tocopherol (alpha-T), and freeze-dried whole leaves of Kidachi aloe (Aloe), formation of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-DNA adducts was measured by 32P-post-labeling analysis, and CYP1A1 and CYP1A2 protein levels were analyzed by ELISA. Group 1 rats were fed diet containing 0.02% beta-C, 1.5% alpha-T or 30% Aloe over an 8-day period, while group 2 was given basal diet alone. On day 7, all animals were subjected to two-thirds partial hepatectomy (PH). Twelve hours after PH, they received a single dose of the carcinogenic food pyrolysate IQ (100 mg/kg) intragastrically, to initiate hepatocarcinogenesis. Rats were killed 6, 12, 24 and 48 h after IQ administration. The levels of adducts, expressed as relative adduct labeling values in rats treated with beta-C, alpha-T and Aloe, were decreased as compared with the control group at hour 24 (36 h after PH), with a significant difference in the case of the beta-C group (46.4% of the control value). Similarly, all showed a tendency for decrease at hour 48. Furthermore, the levels of CYP1A2, known to be responsible for activation of IQ, showed a significant reduction at hour 24. It is concluded that beta-C, and possibly also alpha-T and Aloe, have the potential to reduce IQ-DNA adduct formation, presumably as a result of decreased formation of active metabolites. The results may explain, at least in part, the previously observed inhibitory effects of these compounds on induction of preneoplastic hepatocellular lesions.

Hemolytic uremic syndrome following hemorrhagic colitis caused by verotoxin-producing Escherichia coli O157:H7: early signs of hemolytic uremic syndrome

Ten cases of hemolytic uremic syndrome (HUS) following hemorrhagic colitis caused by verotoxin T2-producing Escherichia coli O157:H7 (VTEC) occurred in a Kindergarten. Slight changes in results of peripheral blood and blood chemistry studies an average of 4 days after onset suggested HUS, and within the following 12 hours platelet counts and levels of haptoglobin and lactic dehydrogenase decreased. Treatment was mainly directed toward the management of renal failure and included supportive therapy and anticoagulant and antiplatelet treatment. Although neurological complications occurred in some cases, all patients eventually recovered completely.

Analysis of methicillin-resistant and methicillin-susceptible Staphylococcus aureus by a molecular typing method based on coagulase gene polymorphisms

A molecular typing method for Staphylococcus aureus based on coagulase gene polymorphisms (coagulase gene typing) was evaluated by examining a total of 240 isolates which comprised 210 methicillin-resistant S. aureus (MRSA) and 30 methicillin-susceptible S. aureus (MSSA) collected from a single hospital. By AluI restriction enzyme digestion of the PCR-amplified 3'-end region of the coagulase gene including 81-bp repeated units, the MRSA and MSSA isolates examined were divided into 6 and 12 restriction fragment length polymorphism (RFLP) patterns, respectively, whereas five patterns were commonly detected in MRSA and MSSA. MRSA isolates that showed a particular RFLP pattern were considered to be predominant in the hospital. Coagulase typing with type-specific antisera was also performed for all S. aureus isolates for comparison. Coagulase types II and VII were most frequently detected and included isolates with four and five different AluI RFLP patterns, respectively, whereas each of the other coagulase types corresponded to a single RFLP pattern. These results indicated that RFLP typing was more discriminatory than serological typing, for typing S. aureus and demonstrated its utility in epidemiologic investigation of S. aureus infection in hospitals.

Accurate measurement of the radius of curvature of a concave mirror and the power dependence in a high-finesse Fabry-Perot interferometer

We describe the accurate measurement of the radius of curvature of a concave mirror in a Fabry-Perot interferometer with a finesse of 78,100. The radius of curvature of the concave mirror is determined by measuring the free spectral range and the transverse-mode range with the frequency response functions. The radii of curvature at two orthogonal (x and y) axes on the mirror surface resulting from the polishing nonisotropy were accurately measured to be r(x) = 1008.46 mm and r(y) = 1006.94 mm, respectively, with an accuracy of 8 × 10(-5). This accuracy is the best to our knowledge. The power dependence of the radii of curvature to the cavity internal intensity at a steady state was measured to be dr(x)/dI(c) = +60 µm/(MW/cm(2)) at the x axis and dr(y)/dI(c) = +47 µm/(MW/cm/(2)) at the y axis to an intensity of 2.1 MW/cm(2).