The Simons Observatory: A fully remote controlled calibration system with a sparse wire grid for cosmic microwave background telescopes.

For cosmic microwave background (CMB) polarization observations, calibration of detector polarization angles is essential. We have developed a fully remote controlled calibration system with a sparse wire grid that reflects linearly polarized light along the wire direction. The new feature is a remote-controlled system for regular calibration, which has not been possible in sparse wire grid calibrators in past experiments. The remote control can be achieved by two electric linear actuators that load or unload the sparse wire grid into a position centered on the optical axis of a telescope between the calibration time and CMB observation. Furthermore, the sparse wire grid can be rotated by using a motor. A rotary encoder and a gravity sensor are installed on the sparse wire grid to monitor the wire direction. They allow us to achieve detector polarization angle calibration with an expected systematic error of 0.08°. The calibration system will be installed in small-aperture telescopes at Simons Observatory.

[Multicenter Evaluation of Cine Angiography and Digital Subtraction Angiography Dose Rate for Various Angiography Programs: Comparison with Fluoroscopic Dose Rate].

We conducted a nationwide multicenter survey of various interventional radiology (IVR) procedures. Data were collected from 385 X-ray systems in 126 institutions, including 432 cine programs and 380 digital subtraction angiography (DSA) programs for diagnostic catheterization, percutaneous coronary intervention (PCI), ablation, transcatheter aortic valve implantation (TAVI), neurologic IVR, thorax IVR, abdominal IVR, and endovascular therapy (EVT). Fluoroscopic and cine dose rates were 10.1 mGy/min and 110.7 mGy/min, respectively, whereas for DSA programs, the median fluoroscopic and DSA dose rates were 8.0 mGy/min and 224.8 mGy/min, respectively. The DSA dose rate was more than twice the cine dose rate. The largest difference between dose rates was for diagnostic catheterization, which had a cine dose rate of 142.6 mGy/min and a fluoroscopic dose rate of 12.6 mGy/min (by a factor of 12.5), followed by EVT, which had a DSA dose rate of 216.0 mGy/min and a fluoroscopic dose rate of 7.7 mGy/min (by a factor of 29.6). The smallest difference between dose rates was for TAVI, which had a cine dose rate of 96.8 mGy/min and a fluoroscopic dose rate of 12.0 mGy/min (by a factor of 8.9), followed by neurologic IVR, which had a DSA dose rate of 227.9 mGy/min and a fluoroscopic dose rate of 9.6 mGy/min (by a factor of 22.6). Compared with the fluoroscopic dose rates, the cine dose rates were 9-13 times higher and the DSA dose rates were 22-30 times higher; the DSA dose rates were more than double the cine dose rates.

[Multicenter Follow-up Survey on Radiation Dose Levels in Cardiovascular X-ray Apparatus under Percutaneous Coronary Intervention Conditions].

It is important to optimize the exposure dose when conducting interventional radiology, but optimization is difficult for medical centers to achieve independently. In 2005, we administered a questionnaire on the measurement of dose rates and awareness of exposure reduction when performing percutaneous coronary intervention. Ten years later, we conducted a follow-up survey of the same 31 centers to determine the current situation and identify trends. The results of the survey showed that the mean fluoroscopy dose rate decreased to 55% of the 2005 value, from 28.2 to 15.6 mGy/min, and the mean radiography dose rate decreased to 71% of the 2005 value, from 4.2 to 3.0 mGy/s. Dose rates for both fluoroscopy and radiography decreased by 84% of facilities. The results also indicated greater cooperation by physicians compared to 10 years ago. In particular, there was a considerable increase in the exchange of ideas with physicians regarding exposure, suggesting a stronger level of interest in exposure. The overall score for questionnaire items was 33% higher than that in the previous survey. These results show that in the past 10 years, awareness of exposure reduction has improved, and dose optimization has been a major factor in the downward trend in dose rates in radiography and fluoroscopy.

[Multicenter Survey on Radiation Dose of Cardiac Intervention].

We conducted a nationwide survey of multiple institutions and collected data of various interventional procedures in the field of cardiology. Included in the analysis were 126 institutions, 381 X-ray systems, and 805 protocols. The dose values were compared with the Japanese diagnostic reference levels (DRLs) 2015. Fluoroscopy time, air kerma at the patient entrance reference point (Ka, r), and air kerma-area product (PKA ) were analyzed for various interventional procedures in 5,734 cardiology patients. The fluoroscopic dose rate (FDR) for pulmonary vein isolation (PVI) was less than half that of the 75th percentile of the Japanese DRLs 2015. The 75th percentiles of fluoroscopy time, Ka, r, and PKA for the respective interventional procedures were as follows: 11.0 min, 735 mGy, and 64 Gyï½¥cm2 for diagnostic coronary angiography (CA); 13.2 min, 839 mGy, and 75 Gyï½¥cm2 for CA + left ventriculography; 34.4 min, 1,810 mGy, and 148 Gyï½¥cm2 for percutaneous coronary intervention (PCI) excluding chronic total occlusion; 80.1 min, 4,338 mGy, and 312 Gyï½¥cm2 for PCI for chronic total occlusion; 74.4 min, 833 mGy, and 90 Gyï½¥cm2 for PVI; and 34.0 min, 795 mGy, and 94 Gyï½¥cm2 for transcatheter aortic valve implantation, respectively. In assessing dose values in interventional radiology, the difficulty of the technique needs to be considered, and the DRL values for FDR, fluoroscopic time, Ka, r, and PKA for each interventional procedure are considered necessary when reassessing or updating DRLs.

[Multicenter Survey of the Display Air Kerma and Actual Measured Values in IVR X-ray Apparatus].

PURPOSE: We conducted a multicenter study to investigate the current status of difference between the actual values at the patient entrance reference point (PERP) and display air kerma. METHODS: We exposure dose and fluoroscopy dose were measured by 32 apparatuses at 32 member institutions of the Japanese Society of Circulation Imaging Technology (CITEC) under unified conditions, and the actual measured values and display air kerma were compared. We entrance doses during fluoroscopy and imaging were measured at the PERP, with focus detector distance (FDD) 110 cm, a copper plate of 3.5 mm in thickness adhered to the front face of flat panel detector (FPD) as absorber, field-of-view (FOV) 18 cm, and the frame rate of 15 f/s, excluding the bed. Display air kerma were recorded at the same time. JIS (Z 4751-2-43: 2012) specify "The reference air kerma rate and the cumulative reference air kerma shall not deviate from their respective display air kerma by more than ±35% over the range of 6 mGy/min and 100 mGy to the maximum value." The number of apparatuses display air kerma deviated from this condition and its percentage were obtained. RESULTS: The mean difference percentage between actual measured values and display air kerma in 32 apparatuses was approximately 15.6%, with some apparatuses showing substantially different display air kerma. CONCLUSION: In order to estimate patients' skin exposure dose from display air kerma more accurately, it is necessary to perform calibration of the apparatus by regular dose measurement or convert values.

Survey of Exposure Dose during Percutaneous Coronary Intervention for Chronic Total Occlusion.

During percutaneous coronary intervention (PCI) for chronic total occlusion (CTO), longer fluoroscopic time as compared with PCI for non-CTO lesions may cause skin injury by increased radiation. We have performed a multi-center observational study comparing the exposed dose during the PCI of CTO (CTO group) and during the PCI of non-CTO lesions (non-CTO group). Exposure doses were assessed in 313 patients with CTO and 3,310 patients with non-CTO lesions. Total fluoroscopy time (59.0 ±35.5 vs 26.8 ±18.8 min, p<0.0001) and the total air kerma (2.76±2.11 vs 1.27±0.94 Gy, p<0.0001) were significantly greater in the CTO group than in the non-CTO group. The maximum air kerma of the CTO group was 13.62 Gy. Informed consent about the risk of transient depilation and the transient erythema is required for the case with radiation dose over 3 Gy. The frequency of the patient who received radiation >3 Gy was significantly higher in the CTO group as compared with the non-CTO group (34.1% vs 4.9%). Therefore, informed consent before an operation and postoperative follow-up are indispensable for the performed PCI of CTO. Moreover, comprehensive understanding of the exposure dose during operation and to record the final exposure dose may be extremely important for the radiological technologists.

CYP1A1, GSTM1, GSTT1 and NQO1 polymorphisms and colorectal adenomas in Japanese men.

AIM: To investigate the role of functional genetic polymorphisms of metabolic enzymes of tobacco carcinogens in the development of colorectal adenomas. METHODS: The study subjects were 455 patients with colorectal adenomas and 1052 controls with no polyps who underwent total colonoscopy in a preretirement health examination at two Self Defense Forces hospitals. The genetic polymorphisms studied were CYP1A1 2A (rs 4646903), CYP1A1 2C (rs 1048943), GSTM1 (null or non-null genotype), GSTT1 (null or non-null genotype) and NQO1 C609T (rs 1800566). Genotypes were determined by the polymerase chain reaction (PCR)-restriction fragment length polymorphism or PCR method using genomic DNA extracted from the buffy coat. Cigarette smoking and other lifestyle factors were ascertained by a self-administered questionnaire. The associations of the polymorphisms with colorectal adenomas were examined by means of OR and 95%CI, which were derived from logistic regression analysis. Statistical adjustment was made for smoking, alcohol use, body mass index and other factors. The gene-gene interaction and effect modification of smoking were evaluated by the likelihood ratio test. RESULTS: None of the five polymorphisms showed a significant association with colorectal adenomas, nor was the combination of GSTM1 and GSTT1. A borderline significant interaction was observed for the combination of CYP1A1 2C and NQO1 (P = 0.051). The OR associated with CYP1A1 2C was significantly lower than unity among individuals with the NQO1 609CC genotype. The adjusted OR for the combination of the CYP1A1 2C allele and NQO1 609CC genotype was 0.61 (95%CI: 0.42-0.91). Although the interaction was not statistically significant (P = 0.24), the OR for individuals carrying the CYP1A1 2C allele and GSTT1 null genotype decreased significantly compared with those who had neither CYP1A1 2C allele nor GSTT1 null genotype (adjusted OR: 0.69, 95%CI: 0.49-0.97). Smoking did not modify the associations of the individual polymorphisms with colorectal adenomas. There was no measurable effect modification of smoking even regarding the combination of the genetic polymorphisms of the phase I and phase II enzymes. CONCLUSION: Combination of the CYP1A1 2C and NQO1 609CC genotypes was associated with a decreased risk of colorectal adenomas regardless of smoking status.

Comparative study of deoxynivalenol, 3-acetyldeoxynivalenol, and 15-acetyldeoxynivalenol on intestinal transport and IL-8 secretion in the human cell line Caco-2.

The effects of the trichothecene mycotoxin deoxynivalenol (DON) and its acetylated derivatives, 3-acetyldeoxynivalenol (3ADON) and 15-acetyldeoxynivalenol (15ADON) on human intestinal cell Caco-2 were investigated by the studies of transepithelial transport, gene expression, and cytokine secretion. Permeability across a Caco-2 cell monolayer was evaluated by transport study. Transport rates were ranked as DON, 3ADON<15ADON in apical-basolateral direction. 15ADON showed the highest permeability, induced the highest decrease in transepithelial electrical resistance (TEER), and prompted significant Lucifer Yellow permeability. These results showed that 15ADON affect paracellular barrier function extremely. In addition, gene expressions induced by toxins were screened by DNA microarray for investigating cellular effect on Caco-2 cell. The most remarkable gene induced by DON and 15ADON was inflammatory chemokine IL-8 and thus mRNA expression and secretion of IL-8 were analyzed by PCR and ELISA. Both DON and acetylated DONs could induce mRNA expression and production of IL-8. In particular, ELISA assay showed that the ability to produce IL-8 was ranked as 3ADON

A new reference point for patient dose estimation in neurovascular interventional radiology.

In interventional radiology, dose estimation using the interventional reference point (IRP) is a practical method for obtaining the real-time skin dose of a patient. However, the IRP is defined in terms of adult cardiovascular radiology and is not suitable for dosimetry of the head. In the present study, we defined a new reference point (neuro-IRP) for neuro-interventional procedures. The neuro-IRP was located on the central ray of the X-ray beam, 9 cm from the isocenter, toward the focal spot. To verify whether the neuro-IRP was accurate in dose estimation, we compared calculated doses at the neuro-IRP and actual measured doses at the surface of the head phantom for various directions of the X-ray projection. The resulting calculated doses were fairly consistent with actual measured doses, with the error in this estimation within approximately 15%. These data suggest that dose estimation using the neuro-IRP for the head is valid.

Coffee consumption, serum γ-glutamyltransferase, and glucose tolerance status in middle-aged Japanese men.

BACKGROUND: Recently, coffee consumption has been related to decreased risk of type 2 diabetes mellitus (DM) among those with high levels of serum γ-glutamyltransferase (GGT). We examined the association between coffee and glucose tolerance, determined by a 75 g oral glucose tolerance test, and the effect modification of serum GGT on the association. METHODS: The study subjects were 5320 men aged 46-60 years who received a health examination at two Self-Defense Forces hospitals from January 1997 to March 2004. Those medicated for DM were excluded. Coffee consumption was classified into <1, 1-2, 3-4, and ≥5 cups/day. Statistical adjustment was made for age, body mass index, smoking, alcohol use, leisure-time physical activity, green tea consumption, parental diabetes, hospital, and rank in the Self-Defense Forces. RESULTS: Men with normal glucose tolerance, isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT), combined IFG/IGT, and type 2 DM numbered 3384, 398, 790, 348, and 400, respectively. The prevalence odds of isolated IGT, combined IFG/IGT, and type 2 DM, but not of isolated IFG, decreased with increasing consumption of coffee. An inverse association with coffee was observed for isolated IGT in both low (≤40 IU/L) and high (>40 IU/L) GGT groups, and for combined IFG/IGT and type 2 DM in the latter group. CONCLUSIONS: Coffee drinking is protective against glucose intolerance. A possible effect modification of GGT on the coffee-DM association warrants further studies.

Methionine synthase and thymidylate synthase gene polymorphisms and colorectal adenoma risk: the self defense forces study.

Folate-mediated one-carbon metabolism has been implicated in colorectal carcinogenesis. We investigated associations of functional genetic polymorphisms of methionine synthase (MTR), MTR reductase (MTRR), and thymidylate synthase (TS) with colorectal adenomas. The study subjects were 455 cases of colorectal adenomas and 1052 controls with no polyp at colonoscopy. Genotypes were determined for MTR A2756G, MTRR A66G and two polymorphisms in the TS gene, 28-bp tandem repeat polymorphism in the promoter enhancer region (TSER) and 6-bp deletion polymorphism at position 1494 in the 3' untranslated region (TS 1494del6). We also examined the alcohol-genotype and gene-gene interactions on adenoma risk. The GG genotype of MTR A2756G was associated with an increased risk of colorectal adenomas; odds ratios for AG and GG versus AA genotype were 0.99 (95% confidence interval 0.78-1.26) and 1.72 (1.04-2.82), respectively. The increase in the risk associated with MTR 2756GG genotype was evident in men with high alcohol consumption (≥30 mL/d), but not in those with low alcohol consumption (interaction P = 0.03). Men who were homozygous for the TSER double-repeat allele had a slightly decreased risk of colorectal adenomas as compared with those homozygous for the TSER triple-repeat allele. Neither MTRR A66G nor TS 1494del6 was associated with colorectal adenomas. There was no measurable interaction either between MTR A2756G and MTRR A66G or between TSER and TS 1494del6. MTR A2756G appears to be associated with colorectal adenoma risk differently according to alcohol consumption. The MTR-catalyzed reaction may play an important role in the development of colorectal adenomas.

[Anxiolytic].

This chapter outlines the clinician' s guide for prescription of benzodiazepine anxiolytics and 5-HT1A receptor agonists. 5-HT1A receptor agonists have entirely different pharmacological mechanism of action from benzodiazepines, and the pattern of their use is quite different from benzodiazepines. In the global trend, there are strict regulations for the prescription of benzodiazepines, because of the risk of low-dose dependence. Benzodiazepines are recommended for the use only when necessary in the short term. In contrast, benzodiazepines have many clinical indications, compared with 5-HT1A receptor agonists. In Japan, there is no strict regulation to prescription of benzodiazepines. However, we now tend to follow international trends in general.

Development of a simultaneous liquid chromatography/tandem mass spectrometric method for the determination of type B trichothecenes, their derivatives, and precursors in wheat.

A method coupling liquid chromatography with tandem mass spectrometry (LC/MS/MS) was developed for the simultaneous quantitative determination of trichothecenes, nivalenol, deoxynivalenol, deoxynivalenol-3-glucoside, fusarenon-X, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, isotrichodermin, calonectrin, 3-deacetylcalonectrin, 15-deacetylcalonectrin, 3,15-diacetylnivalenol, 4,15-diacetylnivalenol, 3,15-diacetyldeoxynivalenol, and 3,4,15-triacetylnivalenol. The analytical parameters of trichothecenes and their derivatives were optimized to enable their highly sensitive detection. Evaluation of clean-up procedures using Multisep #226 and #227 indicated that Multisep #227 was more suitable for their simultaneous detection in wheat. In performance validation studies using the LC/MS/MS method with Multisep #227 cleanup, good recoveries ranging from 84% to 115% with relative standard deviations from 0.4% to 7.2% were measured. The limits of detection and quantification ranged from 0.03 to 1.4 ng·g(-1) and from 0.1 to 4.7 ng·g(-1) , respectively. The effect of matrices using matrix-matched calibration was estimated to range from 80% to 117% after Multisep #227 cleanup. Multisep #227 clean-up procedure with matrix-free standard calibration achieved accurate quantification without having a considerable effect on matrix compounds. Using the developed method, several trichothecene derivatives and precursors were detected in fungally inoculated wheat samples. The developed LC/MS/MS method is a practical technique that can be used for the quantification of trichothecenes in wheat. This study is the first report of an analytical method used for the simultaneous quantification of major trichothecenes, their derivatives and precursors.

International Pig-a gene mutation assay trial: evaluation of transferability across 14 laboratories.

A collaborative international trial was conducted to evaluate the reproducibility and transferability of an in vivo mutation assay based on the enumeration of CD59-negative rat erythrocytes, a phenotype that is indicative of Pig-a gene mutation. Fourteen laboratories participated in this study, where anti-CD59-PE, SYTO 13 dye, and flow cytometry were used to determine the frequency of CD59-negative erythrocytes (RBC(CD59-)) and CD59-negative reticulocytes (RET(CD59-)). To provide samples with a range of mutant phenotype cell frequencies, male rats were exposed to N-ethyl-N-nitrosourea (ENU) via oral gavage for three consecutive days (Days 1-3). Each laboratory studied 0, 20, and 40 mg ENU/kg/day (n = 5 per group). Three sites also evaluated 4 mg/kg/day. At a minimum, blood samples were collected three times: predosing and on Days 15 and 30. Blood samples were processed according to a standardized sample processing and data acquisition protocol, and three endpoints were measured: %reticulocytes, frequency of RET(CD59-) , and frequency of RBC(CD59-) . The methodology was found to be reproducible, as the analysis of technical replicates resulted in experimental coefficients of variation that approached theoretical values. Good transferability was evident from the similar kinetics and magnitude of the dose-related responses that were observed among different laboratories. Concordance correlation coefficients showed a high level of agreement between the reference site and the test sites (range: 0.87-0.99). Collectively, these data demonstrate that with adequate training of personnel, flow cytometric analysis is capable of reliably enumerating mutant phenotype erythrocytes, thereby providing a robust in vivo mutation assay that is readily transferable across laboratories.

Lack of influence of the ADH1B Arg47His genetic polymorphism on risk of colorectal adenoma in middle-aged Japanese men.

Alcohol consumption is one of the risk factors for colorectal cancers and adenomas. Since alcohol dehydrogenase is a key enzyme in alcohol metabolism, it may thus play a role in colorectal carcinogenesis. The present study was conducted to assess the association of a functional ADH1B Arg47His polymorphism with colorectal adenomas in a case-control study of male officials in the Self-Defense Forces who received a pre-retirement health examination at two Self-Defense Forces hospitals. The study subjects comprised 455 with colorectal adenomas and 1,052 controls without polyps, all of whom underwent total colonoscopy. Statistical adjustment was made for age, hospital, Self-Defense Forces rank, body mass index, cigarette-years, and alcohol consumption. There was no measurable association between the ADH1B Arg47His polymorphism and colorectal adenoma development. The adjusted odds ratio for individuals with the 47His/His genotype compared to those with individuals with 47Arg alleles was 1.18 (95% confidence interval 0.94-1.49). There was no influence of the level of alcohol consumption (interaction P = 0.84). In addition, there were no clear interactions of the ADH1B with ALDH2 Glu487Lys and MTHFR C677T with regard to the risk of colorectal adenoma. In conclusion, the present study suggested that the ADH1B Arg47His polymorphism does not contribute to the risk of colorectal adenoma in any subgroup of middle-aged Japanese men defined by alcohol drinking, as well as the ALDH2 Glu487Lys and MTHFR C677T genotypes.

Rapid detection of nivalenol and deoxynivalenol in wheat using surface plasmon resonance immunoassay.

A surface plasmon resonance (SPR) immunoassay using a monoclonal antibody was developed to measure nivalenol (NIV) and deoxynivalenol (DON) contamination in wheat. A highly sensitive and stable DON-immobilized sensor chip was prepared, and an SPR detection procedure was developed. The competitive inhibition assay used a monoclonal antibody that cross-reacts with NIV and DON. The half maximal inhibitory concentration (IC(50)) values of the SPR assay were 28.8 and 14.9 ng mL(-1) for NIV and DON, respectively. The combined responses of NIV and DON in wheat were obtained using a simultaneous detection assay in a one-step cleanup procedure. NIV and DON were separated using a commercial DON-specific immunoaffinity column (IAC) and their responses were obtained using an independent detection assay. Spiked tests using these toxins revealed that recoveries were in the range 91.5-107% with good relative standard deviations (RSDs) (0.40-4.1%) and that detection limits were 0.1 and 0.05 mg kg(-1) for NIV and DON, respectively. The independent detection using IAC showed detection limits of 0.2 and 0.1 mg kg(-1) for NIV and DON, respectively. SPR analysis results were correlated with those obtained using a conventional LC/MS/MS method for wheat co-contaminated with NIV and DON. These results suggested that the developed SPR assay is a practical method to rapidly screen the NIV and DON co-contamination of wheat and one of a very few immunoassays to detect NIV directly.

Measurement of the isotope ratio of acetic acid in vinegar by HS-SPME-GC-TC/C-IRMS.

Acetic acid is the main ingredient of vinegar, and the worth of vinegar often depends on the fermentation of raw materials. In this study, we have developed a simple and rapid method for discriminating the fermentation of the raw materials of vinegar by measuring the hydrogen and carbon isotope ratio of acetic acid using head space solid-phase microextraction (HS-SPME) combined with gas chromatography-high temperature conversion or combustion-isotope ratio mass spectrometry (GC-TC/C-IRMS). The measurement of acetic acid in vinegar by this method was possible with repeatabilities (1sigma) of +/-5.0 per thousand for hydrogen and +/-0.4 per thousand for carbon, which are sufficient to discriminate the origin of acetic acid. The fermentation of raw materials of several vinegars was evaluated by this method.

Circulating vitamin D and colorectal adenomas in Japanese men.

Accumulating evidence suggests that vitamin D has anticarcinogenic effects. However, it is unclear whether the nutrient is involved in the early stage of colorectal carcinogenesis. We examined the association between circulating vitamin D concentrations and colorectal adenomas in Japanese men. The study subjects comprised 656 cases of colorectal adenomas and 648 controls with normal colonoscopy among male self defense officials receiving a pre-retirement health examination between 1997 and 2004. Plasma or serum levels of 25-hydroxyvitamin D [25(OH)D] were measured using a radioimmunoassay method. Logistic regression analysis was used to obtain odds ratios (OR) and 95% confidence intervals (CI) with adjustment for potential confounding variables. Overall, there was no measurable association between circulating 25(OH)D concentrations and colorectal adenomas. When the analysis was restricted to subjects whose blood was taken during the winter season (November-April), the prevalence odds of colorectal adenomas for the highest versus lowest quartile of 25(OH)D was statistically significantly decreased (OR = 0.58; 95% CI = 0.34-0.99). The reduction was more pronounced for the rectum (OR = 0.22) and distal colon (OR = 0.47) than for proximal colon (OR = 0.70). During the summer season (May-October), higher levels of 25(OH)D were associated with an increased odds of small, but not large, adenomas. The present study adds to evidence that high levels of circulating vitamin D measured during darker season is associated with decreased prevalence of adenomas in the distal sites of the colorectum.

C-reactive protein and colorectal adenomas: Self Defense Forces Health Study.

Chronic inflammation has been implicated in colorectal carcinogenesis. Several studies have investigated the relationship between C-reactive protein (CRP), a biomarker of inflammation, and colorectal cancer and adenomas, resulting in inconsistent findings. The present study examined the relationship between circulating levels of high-sensitivity CRP and colorectal adenomas. The study subjects comprised 646 cases of colorectal adenoma and 635 controls of normal total colonoscopy among men receiving a preretirement health examination at two hospitals of the Self Defense Forces. Statistical adjustment was made for cigarette smoking, alcohol use, body mass index, physical activity, and other potential confounders. The multivariate-adjusted geometric means showed no measurable differences between adenoma cases and controls, but were higher among cases with larger adenomas (trend P = 0.03). Likewise, although the prevalence odds of colorectal adenomas did not differ according to CRP levels as categorized at the 30th, 60th, and 90th percentiles in the controls, higher levels of CRP were associated with a statistically significant increase in the prevalence odds of large adenomas (> or = 5 mm), but not of small adenomas (<5 mm). The multivariate-adjusted odds ratios of large adenomas for the lowest to highest categories of CRP were 1.00 (referent), 1.81 (95% confidence interval 1.17-2.80), 1.61 (95% confidence interval 1.03-2.52), and 2.21 (95% confidence interval 1.28-3.84), respectively (trend P = 0.01). A positive association between CRP and prevalence odds of large adenomas was not modified by either smoking or overweight. These findings suggest that inflammation is linked to the growth of colorectal adenomas.