Dietary habits and risk of lung cancer death in a large-scale cohort study (JACC Study) in Japan by sex and smoking habit

Lung cancer has increased and is the leading cause of cancer death among Japanese males. The associations of dietary habits with the risk of lung cancer death were evaluated by sex and smoking habits in this study. In the Japan Collaborative Cohort (JACC) Study, a cohort established in 1988 - 90 and consisting of 42 940 males and 55 308 females was observed for lung cancer deaths up to the end of 1997. During the observation period, 446 males and 126 females died of lung cancer. A self-administered food frequency questionnaire was used as the baseline survey. Hazard ratios for dietary factors were calculated by Cox's proportional hazards model. Among males, a high intake of ham and sausages, cheese, green-leafy vegetables, oranges, and other fruits significantly and dose-dependently decreased the risk of lung cancer death. Among females, a high intake of miso-soup, ham and sausages, and liver significantly and almost dose-dependently increased the risk. Vegetables and fruits rich in antioxidative and carcinogenic agents reduced the risk of lung cancer deaths among male smokers more than among female nonsmokers. The results among female nonsmokers were partially consistent with the hypothesis that high fat consumption increases the risk of lung cancer, especially that of adenocarcinoma.

Passive smoking at home and cancer risk: a population-based prospective study in Japanese nonsmoking women

OBJECTIVES

To investigate the relationship between passive smoking at home and the incidence of various cancers in a population-based prospective study.

METHODS

The subjects were 9675 Japanese lifelong nonsmoking women aged over 40 years who lived in three municipalities of Miyagi Prefecture, and completed a self-administration questionnaire in 1984. During 9 years of follow-up, 426 cancers were identified by record linkage to the population-based cancer registry. The data were analyzed using the Cox proportional hazards model.

RESULTS

The age-adjusted relative risks (RR) and 95% confidence intervals (CI) of smoking-related cancers and lung cancer for women who had smoking husbands, compared with women whose husbands did not smoke, were 1.7 (0.94 2.9, p = 0.079) and 1.9 (0.81-4.4, p = 0.14), respectively. In contrast, a significant inverse association was observed for breast cancer, the RR (95% CI) was 0.58 (0.34-0.99, p = 0.047). After multivariate adjustment for confounding factors, the risks of smoking-related cancers and breast cancer were materially unchanged.

CONCLUSIONS

These results show that passive smoking may affect the risk of cancers other than lung cancer.

Contribution of both the sarcolemmal K(ATP) and mitochondrial K(ATP) channels to infarct size limitation by K(ATP) channel openers: differences from preconditioning in the role of sarcolemmal K(ATP) channels

The roles of sarcolemmal ATP-sensitive K+ (sarcK(ATP)) and mitochondrial ATP-sensitive K+ (mitoK(ATP)) channels in the cardioprotection induced by K(ATP) channel openers remain unclear, though the mitoK(ATP) channel has been proposed to be involved as a subcellular mediator in cardioprotection afforded by ischemic preconditioning (PC). In the present study, selective inhibitors of the sarcK(ATP) and mitoK(ATP) channels were used to examine the role of each channel subtype in infarct size limitation by KATP channel openers. Isolated rabbit hearts were perfused in the Langendorff mode with monitoring of the activation recovery interval (ARI) and subjected to 30-min global ischemia/2-h reperfusion to induce infarction. Before ischemia, hearts received 10 microM pinacidil, 100 microM diazoxide, or PC with or without preceding infusion of a sarcK(ATP) channel-selective blocker (5 microM HMR1098) or a mitoK(ATP) channel-selective blocker (100 microM 5-hydroxydecanoate, 5-HD). ARI, an index of action potential duration, was shortened from 118+/-3 ms to 77+/-5 ms after 10 min of ischemia in untreated control hearts. Pinacidil shortened ARI before ischemia from 113+/-2 ms to 78+/-5 ms and enhanced the ARI shortening during ischemia. Diazoxide did not affect ARI before ischemia but accelerated ischemia-induced shortening of ARI. Infarct size as a percentage of the left ventricle (%IS/LV) was reduced by pinacidil and diazoxide from the control value of 47.2+/-4.0% to 4.5+/-1.5% and 5.2+/-1.2%, respectively. HMR1098 significantly inhibited the shortening of ARI by ischemia, pinacidil and diazoxide and partially blocked infarct size limitation by these K(ATP) channel openers (%IS/LV=32.6+/-4.2% and 23.4+/-5.3%, respectively). Infusion of 5-HD did not modify the change in ARI caused by the K(ATP) channel openers but completely abolished cardioprotection (%IS/LV=46.0+/-6.2% with pinacidil and 57.2+/-7.0% with diazoxide). PC with two episodes of 5-min ischemia limited %IS/LV to 21.6+/-4.0%, and this protection was not inhibited by HMR1098. Neither HMR1098 nor 5-HD alone modified infarct size. In conclusion, both sarcK(ATP) and mitoK(ATP) channels may contribute to the anti-infarct tolerance afforded by pinacidil and diazoxide.

Successful treatment of patients with rheumatic disorders and acquired factor VIII inhibitors with cyclophosphamide and prednisolone combination therapy: two case reports

Acquired haemophilia associated with autoimmune disorders can be fatal and has been reported to be refractory to steroid therapy alone. We report two cases of female patients, aged 24 years and 54 years, with acquired haemophilia caused by factor VIII inhibitors. Underlying diseases were systemic lupus erythematosus in the 24-year-old patient and rheumatoid arthritis in the 54-year-old patient. Both conditions were nearly quiescent when the patients manifested haemorrhagic diathesis. In response to combination therapy with prednisolone and cyclophosphamide, coagulation abnormalities were resolved together with complete elimination of factor VIII inhibitors in both patients. Thus, combination therapy with alkylating agents may be recommended as initial therapy for the management of autoimmune patients with factor VIII inhibitors.

Validity and reliability of single-item questions about physical activity

The Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study) included in its self-administered questionnaires some single-item questions concerning physical activity. We examined the validity of the questions among 1,730 Japanese adults and the reliability of the questions among 1,075 Japanese adults. The validity of the sports and physical exercise questions was estimated by comparing the self-administered questionnaire responses with the time spent on the activity and the energy expenditure index for the previous 12-month period, elicited by the interviewing method used in the Japan Lifestyle Monitoring Study with a minor modification. The Spearman's rank correlation coefficients ranged from 0.43 to 0.60, showing moderate correlations. On the other hand, test-retest reliability was estimated by comparing the responses from two separate surveys conducted roughly one year apart. Weighted kappa coefficients of sports and physical exercise questions, classified according to sex and age, ranged from 0.39 to 0.56, showing moderate reliability; and those of a question about walking ranged from 0.25 to 0.39, showing fair reliability. We suggest that measuring physical activity level with these single-item questions may be appropriate for establishing baseline data that reflects long-term physical activity in a large-scale cohort study targeting lifestyle-related diseases.

Decrease in risk of lung cancer death in males after smoking cessation by age at quitting: findings from the JACC study

To evaluate the impact of smoking cessation in individuals and populations, we examined the decrease in risk of lung cancer death in male ex-smokers by age at quitting in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study), which was initiated from 1988 to 1990 in Japan. For simplicity, subjects were limited to male non-smokers, and former / current smokers who started smoking at ages 18 - 22, and 33654 men aged 40 - 79 years were included. We modeled the mortality rates in non-smokers and current smokers, and compared the rates in ex-smokers with those expected from the model if they had continued smoking. During the mean follow-up of 8.0 years, 341 men died from lung cancer. The mortality rate ratio for current smokers, compared to non-smokers, was 5.16, and those for ex-smokers who had quit smoking 0 - 4, 5 - 9, 10 - 14, 15 - 19 and > or = 20 years before were 4.84, 3.19, 2.03, 1.29 and 0.99, respectively. The functions of 3.20 x 10(-7) x (age)(4.5) and 1.96 x 10(-5) x (age - 29.6)(4.5) fitted the observed mortality rates (per 100000 person-years) in non-smokers and continuing smokers, respectively. A greater decrease in lung cancer mortality was estimated among those who quit smoking at younger ages. Stopping smoking earlier in life appears preferable to keep the individual risk low. The absolute rate, however, substantially decreased after smoking cessation even in those who quit at ages 60 - 69, reflecting the high mortality rate among continuing smokers in the elderly.

Borna disease: virus-induced neurobehavioral disease pathogenesis

Studies of the pathogenesis of neurobehavioral diseases following Borna disease virus infections have been increasing rapidly over the past ten years. Recent major advances have included a report of vertical transmission of the virus in its natural host, the horse, and a report of isolation of a novel variant, No/98, in that same species. In rats infected neonatally with the Borna disease virus that lack blood-borne inflammation in the brain, evidence of an "endogenous" brain inflammatory response is abundant, with elevated expression of cytokine and chemokine mRNA. Infection in these rats is also associated with abnormal levels of neurotransmitters, including serotonin and norepinephrine. Data and debate continue to be forthcoming about the role of Borna disease virus in human infection and psychiatric disease.

Impact of smoking habit on medical care use and its costs: a prospective observation of National Health Insurance beneficiaries in Japan

BACKGROUND

To quantify excess medical use associated with smoking, a large prospective cohort study is needed. The authors examined the impact of smoking on medical care use in a large population-based cohort with an accurate data collecting system in Japan.

METHOD

The data were derived from a 30-month prospective cohort study of 43,408 National Health Insurance beneficiaries aged 40--79 years living in a rural Japanese community. The smoking habit of beneficiaries was assessed in a baseline survey at the end of 1994. Medical care use and its costs were monitored by linkage with the National Health Insurance claim history files since January 1995.

RESULTS

Male smokers incurred 11% more medical costs (after adjustment for age, physical functioning status, alcohol consumption, body mass index and average time spent walking) than 'never smokers' but for female smokers and never smokers the costs were almost the same. This difference was mainly attributable to increased use of inpatient medical care among smokers, especially in males, where per month cost of inpatient care was 33% higher in smokers. Age-group specific analysis in men showed that excess mortality and excess medical cost ratio for smokers peaked in those aged 60--69 years.

CONCLUSIONS

Smokers consume excess medical care. Among the population aged 45 years and over, about 4% of total medical costs were attributable to smoking. To pursue both better health and lower medical costs for the nation, a comprehensive programme to reduce tobacco use is needed.

Evaluating the accuracy of uterine cancer screening with the regional cancer registration system

OBJECTIVE

To evaluate the effectiveness of uterine cancer screening by analyzing the accuracy of cervical and endometrial cytodiagnoses as screening methods.

STUDY DESIGN

During the year of April 1, 1991-March 31, 1992, 186,161 and 5,697 women underwent cervical and endometrial cytodiagnoses, respectively, and their cytodiagnostic results were computer registered at the Miyagi Cancer Society. By comparison of these examinees with 753 cancer patients who were registered at the regional cancer registry between 1991 and 1993, 133 individuals who were assumed to be identical between the two systems were selected, and of these cases, 83 patients, including test-positive cases, were found within one year. The sensitivity and specificity of each screening method were investigated.

RESULTS

Regarding examinees diagnosed as having cancer by the same month in the following year after diagnosis on screening as false negative, the sensitivity, specificity and false negative rates of cervical cytodiagnosis were 94.7%, 98.9% and 5.3%, respectively, and those of endometrial cytodiagnosis were 83.3%, 96.7% and 16.7%, respectively.

CONCLUSION

In comparison with the accuracy of cancer examinations for other organs performed by the health care administration, the accuracy of cervical and endometrial cytodiagnoses was sufficient to designate them screening methods.

Green tea and the risk of gastric cancer in Japan

BACKGROUND

Although laboratory experiments and case-control studies have suggested that the consumption of green tea provides protection against gastric cancer, few prospective studies have been performed.

METHODS

In January 1984, a total of 26,311 residents in three municipalities of Miyagi Prefecture, in northern Japan (11,902 men and 14,409 women 40 years of age or older), completed a self-administered questionnaire that included questions about the frequency of consumption of green tea. During 199,748 person-years of follow-up, through December 1992, we identified 419 cases of gastric cancer (in 296 men and 123 women). We used Cox regression to estimate the relative risk of gastric cancer according to the consumption of green tea.

RESULTS

Green-tea consumption was not associated with the risk of gastric cancer. After adjustment for sex, age, presence or absence of a history of peptic ulcer smoking status, alcohol consumption, other dietary elements, and type of health insurance, the relative risks associated with drinking one or two, three or four, and five or more cups of green tea per day, as compared with less than one cup per day, were 1.1 (95 percent confidence interval, 0.8 to 1.6), 1.0 (95 percent confidence interval, 0.7 to 1.4), and 1.2 (95 percent confidence interval, 0.9 to 1.6), respectively (P for trend=0.13). The results were similar after the 117 cases of gastric cancer that were diagnosed in the first three years of follow-up had been excluded, with respective relative risks of 1.2 (95 percent confidence interval, 0.8 to 1.8) 1.0 (95 percent confidence interval, 0.7 to 1.5), and 1.4 (95 percent confidence interval, 1.0 to 1.9) (P for trend=0.07).

CONCLUSIONS

In a population-based, prospective cohort study in Japan, we found no association between green-tea consumption and the risk of gastric cancer.

Theory of photon interference X-ray absorption fine structure

The theory of photon interference x-ray absorption fine structure (piXAFS) is described. Due to coherent x-ray scattering from atoms, a spatial variation of the x-ray intensity is produced inside the sample. The intensity at the x-ray absorbing atom changes according to the incident energy. Thus piXAFS in extended absorption spectra is produced. It extends in a wide energy range over absorption edges. For powders the piXAFS formula has equivalent form as the EXAFS formula, and the Fourier transform provides distances of neighboring atoms from the absorbing atom. Due to a long mean free path of the photon, piXAFS for powders contains sharp structures. They are explained as a crystal grain orientation averaging of the x-ray standing wave effect.

Mitochondrial ATP-sensitive K+ channels play a role in cardioprotection by Na+-H+ exchange inhibition against ischemia/reperfusion injury

OBJECTIVES

The possible role of the ATP-sensitive potassium (KATP) channel in cardioprotection by Na+-H+ exchange (NHE) inhibition was examined.

BACKGROUND

The KATP channel is suggested to be involved not only in ischemic preconditioning but also in some pharmacological cardioprotection.

METHODS

Infarction was induced by 30-min coronary occlusion in rabbit hearts in situ or by 30-min global ischemia in isolated hearts. Myocardial stunning was induced by five episodes of 5-min ischemia/5-min reperfusion in situ. In these models, the effects of NHE inhibitors (cariporide and ethylisopropyl-amiloride [EIPA]) and the changes caused by KATP channel blockers were assessed. In another series of experiments, the effects of EIPA on mitochondrial KATP (mito-KATP) and sarcolemmal KATP (sarc-KATP) channels were examined in isolated cardiomyocvtes.

RESULTS

Cariporide (0.6 mg/kg) reduced infarct size in situ by 40%, and this effect was abolished by glibenclamide (0.3 mg/kg), a nonselective KATP channel blocker. In vitro, 1 microM cariporide limited infarct size by 90%, and this effect was blocked by 5-hydroxydecanoate (5-HD), a mito-KATP channel blocker but not by HMR1098, a sarc-KATP channel blocker. Infarct size limitation by 1 microM EIPA was also prevented by 5-HD. Cariporide attenuated regional contractile dysfunction by stunning, and this protection was abolished by glibenclamide and 5-HD. Ethylisopropyl amiloride neither activated the mito-KATP channel nor enhanced activation of this channel by diazoxide, a KATP channel opener.

CONCLUSIONS

Opening of the mito-KATP channel contributes to cardioprotection by NHE inhibition, though the interaction between NHE and this KATP channel remains unclear.

Measurements of photon interference X-ray absorption fine structure (piXAFS)

Experimental data are presented which demonstrate the existence of a fine structure in extended X-ray absorption spectra due to interference effects in the initial photon state (piXAFS). Interference occurs between the incident electromagnetic wave and its coherently scattered waves from neighboring atoms. Using fine platinum and tungsten powders as well as polycrystalline platinum foil, piXAFS was measured in high-precision absorption experiments at beamline X1 at HASYLAB/DESY over a wide energy range. piXAFS is observed below and above absorption-edge positions in both transmission and total-electron-yield detection. Based on experimental data it is shown that piXAFS is sensitive to geometric atomic structure. Fourier-transformed piXAFS data carry information, comparable with that of EXAFS, about the short-range-order structure of the sample. Sharp structures occur in piXAFS when a Bragg backscattering condition of the incident X-rays is fulfilled. They allow precise measurement of long-range-order structural information. Measured data are compared with simulations based on piXAFS theory. Although piXAFS structures are similarly observed in two detection techniques, the importance of scattering off the sample for the measurements needs to be investigated further. Disentangling piXAFS, multielectron photoexcitations and atomic XAFS in high-precision measurements close to absorption edges poses a challenge for future studies.

Magnetic circular dichroism at transition metal L2,3 edges in D03-type (Fe(1-x)Vx)3Al alloys

Magnetic circular dichroism (MCD) spectra have been measured at the Fe and V L2,3 edges of DO3-type (Fe(1-x)Vx)3Al in order to investigate their local magnetic moments and electronic structures. Large MCD is observed at the Fe L2,3 edges, while the V L2,3 MCD shows relatively small intensity with complicated features. Signs of these MCD spectra indicate an antiferromagnetic coupling between the magnetic moments on Fe and V. According to the analysis based on the magneto-optical sum rules, the magnetic moment decreases with x, but remains fairly large for Fe2VAl, which might arise from its marginally magnetic nature.

Magnetic circular dichroism at transition metal L2,3 edges in D03-type (Fe(1-x)Mn(x))3Al alloys

We have measured magnetic circular dichroism (MCD) spectra at the transition-metal L2,3 edges in D03-type (Fe(1-x)Mn(x))3Al in order to investigate their local magnetic moments. The analysis of the spectra shows that Fe has moments much larger than Mn, whose moment is ferromagnetically coupled with the Fe one. This does not lend support to the antiferromagnetic mechanism proposed for the reduction in magnetization as well as a large Mn moment predicted for x = 1/3. The evolution of satellites found in the Mn spectrum with x increased suggests that the change in the electronic state may result in the magnetization reduction.

[Testicular pure teratoma: a case report]

A 46-year-old man visited our hospital, complaining of fever and painful swelling of the right scrotum contents. The symptoms and signs suggested epididymitis, but testicular tumor could not be excluded. Therefore, high inguinal orchiectomy was performed. Macroscopic findings were compatible with the testicular teratoma, containing hair, and epididymitis. Histological findings revealed that the tumor was composed of mature epidermis with skin appendages, cartilage, hair, bone and adipose tissue, and that many leucocytes infiltrated in the epididymis, resulting in the diagnosis of pure mature teratoma with epididymitis. For 6 months after the operation, no evidence of recurrence has been observed. Despite its histologically benign appearance, primary pure teratoma of the testis has a metastatic and recurrent potential. Therefore, primary pure teratoma should be man aged in the same way as other nonseminomatous germ cell tumors.

A novel experimental technique for atomic X-ray holography

A new experimental technique for reciprocal X-ray holography has been developed. The experimental set-up makes it possible to measure a reciprocal hologram without unwanted mixture of the X-ray fluorescence holography signal. The data are recorded during continuous rotation of the sample, and are accumulated over many revolutions. Thus the sensitivity to fluctuations of the source characteristics is reduced. A very high resolution over a large angular range is also achieved, which allows recording of X-ray standing-wave shapes near Bragg angles. The reconstruction of the measured hologram of a Cu(3)Au crystal gives positions of the nearest and next-nearest neighbours of a fluorescing Cu atom.

Effect of DNA/liposome mixing ratio on the physicochemical characteristics, cellular uptake and intracellular trafficking of plasmid DNA/cationic liposome complexes and subsequent gene expression

In order to identify the important factors involved in cationic liposome-mediated gene transfer, in vitro transfection efficiencies by plasmid DNA complexed with DOTMA/DOPE liposomes at different DNA/liposome mixing ratios were evaluated using four types of cultured cells with respect to their physicochemical properties. Significant changes were observed in the particle size and zeta potential of the complexes as well as in their structures, assessed by atomic force microscopy, which depended on the mixing ratio. In transfection experiments, except for RAW 264.7 cells (mouse macrophages), efficient gene expression was obtained in MBT-2 cells (mouse bladder tumor), NLH3T3 cells (mouse fibroblasts) and HUVEC (human umbilical vein endothelial cells) at an optimal ratio of 1:5, 1:7.5 or 1:5, respectively. On the other hand, cellular uptake of the [32P]DNA/liposome complexes increased in all cell types with an increase in the mixing ratio, which was not reflected by the transfection efficiency. The cellular damage determined by MTT assay was minimal even at the highest DNA/liposome ratio (1:10), indicating that the lower gene expression level at the higher ratio was not due to cytotoxicity induced by the complex. An ethidium bromide intercalation assay showed that the release of plasmid DNA from the complex, following the addition of negatively charged liposomes, was restricted as the mixing ratio increased. Furthermore, confocal microscopic studies using HUVEC showed that the 1:5 complexes exhibited a dispersed distribution in the cytoplasm whereas a punctuate intracellular distribution was observed for the 1:10 complexes. This suggests that there was a significant difference in intracellular trafficking, probably release from the endosomes or lysosomes, of the plasmid DNA/cationic liposome complexes between these mixing ratios. Taken together, these findings suggest that the DNA/liposome mixing ratio significantly affects the intracellular trafficking of plasmid DNA complexed with the cationic liposomes, which is an important determinant of the optimal mixing ratio in cationic liposome-mediated transfection.

Bacillus Calmette-Guérin instillation treatment for carcinoma in situ of the upper urinary tract

OBJECTIVE

To analyse the efficacy and safety of bacillus Calmette-Guérin (BCG) perfusion treatment forcarcinoma in situ (CIS) of the upper urinary tract.

PATIENTS AND METHODS

Six patients with cytologically diagnosed CIS of the upper urinary tract were treated by BCG instillation via retrograde catheterization using a 6 F ureteric catheter or an 8 F indwelling JJ ureteric stent between the ureter and bladder. BCG (Tokyo 172 strain, 80 mg in 100 mL normal saline) was instilled weekly for 4 or 8 weeks. The efficacy and safety of the treatment was assessed.

RESULTS

The mean (range) follow-up was 22 (9-38) months; none of the patients died, and all were negative for cytology in urine collected from the upper urinary tracts. However, one patient had recurrent CIS in the prostatic urethra; the patient was treated by intravesical BCG instillation. In all patients, positive cytology became negative after one or two instillations of BCG. The ureter became stenotic in two patients. Although irritative symptoms occurred in all patients, such side-effects disappeared in a few months and were not clinically significant.

CONCLUSION

In these six patients retrograde BCG instillation for CIS of the upper urinary tract was effective and safe. Based on the cytology results after only two BCG treatments, the dose or number of BCG instillations could possibly be reduced, but further study is needed.

Relationship between health practices and education level in the rural Japanese population

Past studies in Europe and the USA have found that people with higher education levels have better health practices. The aim of this study was to examine the association between health practices and education level among people in a rural Japanese community. Data were derived from the Ohsaki National Health Insurance Cohort Study, which has been following 52,029 NHI beneficiaries, aged 40 to 79 years, in Miyagi Prefecture, Japan. The relationship between education level and seven health indices (smoking, drinking, body mass index, sleeping, exercise, breakfast, and snacks) was analyzed. Higher education was associated with shorter sleeping hours for both men and women, and lower BMI for women. In age groups younger than 70 years, people with higher education tended to exercise more. Smoking for women, alcohol consumption, and a Health Practices Index were not related to education levels. These results are different from those from Europe and the USA. This study suggest that the relationship between health practices and education level is weaker in Japan than in Europe and the USA.

Pseudogap formation in the intermetallic compounds (Fe1-xVx)3Al

Optical conductivity data of the intermetallic compounds (Fe1-xVx)3Al ( 0</=x</=0.33) reveal that their density of states around the Fermi energy ( E(F)) is strongly reduced as x is increased. In particular, Fe2VAl ( x = 0.33) has a deep, well-developed pseudogap of 0.1-0.2 eV at E(F) and a small density ( approximately 5x10(20) cm(-3)) of carriers, which is highly unusual for intermetallic compounds. It is shown that the pseudogap results from the band structure of Fe2VAl, rather than from temperature-dependent correlation effects. Based on the present results, we propose a simple model that consistently explains both the semiconductorlike transport and the metallic photoemission results previously observed for Fe2VAl.

Development of a rapid assay for screening point mutations associated with quinolone resistance in the Pseudomonas aeruginosa parC gene

To detect quinolone resistance-associated mutations within the Ser-80 and Glu-84 codons of the Pseudomonas aeruginosa parC gene, we developed a rapid and simple assay based on polymerase chain reaction (PCR) amplification of the region of the parC gene containing the mutation sites and digestion of the PCR products with a restriction enzyme. The mutations generating alterations at Ser-80 and Glu-84 were detected as restriction fragment length polymorphisms of the PCR products digested with HinfI. Among 22 clinical isolates tested by this assay, mutations at the Ser-80 and Glu-84 codons were detected in all 10 isolates in which the presence of the mutations had been confirmed previously by DNA sequencing. This rapid and simple assay could be a useful screening device for genetic alterations associated with resistance to quinolones in the P. aeruginosa parC gene.