吉田 優

AIM: This study aimed to explore novel metabolite biomarker candidates for screening oral squamous cell carcinoma (OSCC). PATIENTS & METHODS: We collected plasma samples from 48 patients with OSCC and 29 with an oral disease and conducted a plasma metabolomics analysis of patients with OSCC using gas chromatography mass spectrometry. Then, we used the cross-validation procedure to ensure the accuracy of biomarker candidates. RESULTS: We selected four biomarker candidates against OSCC. Their sensitivity was more than 90%, and the AUC was over 0.9 according to the receiver operating characteristic curve analysis. CONCLUSIONS: The findings of this study suggest four potential metabolites as biomarkers for OSCC screening.

AIM: To identify the serum metabolomics signature that is correlated with the chemoradiosensitivity of esophageal squamous cell carcinoma (ESCC). MATERIALS & METHODS: Untargeted and targeted metabolomics analysis of serum samples from 26 ESCC patients, which were collected before the neoadjuvant chemoradiotherapy, was performed. RESULTS: On receiving the results of untargeted metabolomics analysis, we performed the targeted metabolomics analysis of the six metabolites (arabitol, betaine, glycine, L-serine, L-arginine and L-aspartate). The serum levels of the four metabolites (arabitol, glycine, L-serine and L-arginine) were significantly lower in the patients who achieved pathological complete response with neoadjuvant chemoradiotherapy compared with the patients who did not achieve pathological complete response (p = 0.0086, 0.0345, 0.0106 and 0.0373, respectively). CONCLUSION: The serum levels of metabolites might be useful for predicting the chemoradiosensitivity of ESCC patients.

Recently, the omics analysis, which comprehensively analyzed the biological molecules such as DNA, RNA, protein and low molecular weight metabolites, has been developed. The metabolome analysis that comprehensively analyzes low molecular weight metabolites is one of the most recent omics analysis, and attracts rising attention. Evaluating the metabolite alterations and clarifying the metabolite profiles in the body will lead to understandings of biological information, and the metabolome analysis has the potential of elucidation of novel pathological conditions and discovery of metabolite biomarkers. In this article, we explain the characteristics of the omics analysis. Regarding the metabolome analysis, its detailed explanations are carried out, and we also introduce our metabolite biomarker research about pancreatic cancer using the metabolome analysis.

OBJECTIVES: The present study was conducted in order to elucidate the relationship between the number of cyst-existing regions and incidence of pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN), which currently remains unclear. METHODS: Subjects comprised 141 patients undergoing resection for IPMN (Non-invasive IPMN (IPMN with low-to high-grade dysplasia): N = 94, invasive IPMN: N = 31, and PDAC concomitant with IPMN: N = 16) between November 2000 and February 2017. A logistic regression analysis was performed to assess the relationship between the number of cyst-existing regions (one region/two or more regions) and incidence of PDAC concomitant with IPMN, adjusted by clinical characteristics. Cyst-existing regions were defined by the number of anatomical parts of the pancreas: the head/body/tail of the pancreas. RESULTS: Multiple cyst-existing regions (two or more regions) correlated with the incidence of PDAC concomitant with IPMN (PDAC concomitant with IPMN in one region vs. two or more regions: 3/66 vs. 13/75, multivariable odds ratio [OR] = 4.11, 95% confidence interval [CI] = 1.22 to 18.8, P = 0.02). In contrast, multiple cyst-existing regions did not correlate with the incidence of IPMN (invasive IPMN in one region vs. two or more regions: 13/66 vs. 18/75, OR = 1.19, 95% CI = 0.52 to 2.76, P = 0.67). CONCLUSIONS: Multifocal cysts correlated with the incidence of PDAC concomitant with IPMN, and may be a high-risk factor for PDAC concomitant with IPMN.

BACKGROUND: Inflammatory bowel disease (IBD) is an intestinal disorder, involving chronic and relapsing inflammation of the digestive tract. Dysregulation of the immune system based on genetic, environmental, and other factors seems to be involved in the onset of IBD, but its exact pathogenesis remains unclear. Therefore, radical treatments for ulcerative colitis and Crohn's disease remain to be found, and IBD is considered to be a refractory disease. AIMS: The aim of this study is to obtain novel insights into IBD via metabolite profiling of interleukin (IL)-10 knockout mice (an IBD animal model that exhibits a dysregulated immune system). METHODS: In this study, the metabolites in the large intestine and plasma of IL-10 knockout mice were analyzed. In our analytical system, two kinds of analysis (gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry) were used to detect a broader range of metabolites, including both hydrophilic and hydrophobic metabolites. In addition, an analysis of lipid mediators in the large intestine and ascites of IL-10 knockout mice was carried out. RESULTS: The levels of a variety of metabolites, including lipid mediators, were altered in IL-10 knockout mice. For example, high large intestinal and plasma levels of docosahexaenoic acid (DHA) were observed. In addition, arachidonic acid- and DHA-related lipid cascades were upregulated in the ascites of the IL-10 knockout mice. CONCLUSIONS: Our findings based on metabolite profiles including lipid mediators must contribute to development of researches about IBD.

Recently, the use of metabolomic analysis of human serum and plasma for biomarker discovery and disease diagnosis in clinical studies has been increasing. The feasibility of using a metabolite biomarker for disease diagnosis is strongly dependent on the metabolite's stability during pre-analytical blood processing procedures, such as serum or plasma sampling and sample storage prior to centrifugation. However, the influence of blood processing procedures on the stability of metabolites has not been fully characterized. In the present study, we compared the levels of metabolites in matched human serum and plasma samples using gas chromatography coupled with mass spectrometry and liquid chromatography coupled with mass spectrometry. In addition, we evaluated the changes in plasma metabolite levels induced by storage at room temperature or at a cold temperature prior to centrifugation. As a result, it was found that 76 metabolites exhibited significant differences between their serum and plasma levels. Furthermore, the pre-centrifugation storage conditions significantly affected the plasma levels of 45 metabolites. These results highlight the importance of blood processing procedures during metabolome analysis, which should be considered during biomarker discovery and the subsequent use of biomarkers for disease diagnosis.

Discovery of a high-risk group for pancreatic cancer is important for prevention of pancreatic cancer. The present study was conducted as a nested case-control study including 170 pancreatic cancer cases and 340 matched controls of our population-based cohort study involving 30 239 subjects who answered a baseline questionnaire and supplied blood samples. Twelve targeted metabolites were quantitatively analyzed by gas chromatography/tandem mass spectrometry. Odds ratios (OR) and their corresponding 95% confidence intervals (CI) were calculated using conditional logistic regression models. Statistically significant P-value was defined as P < .05. Increasing 1,5-anhydro-d-glucitol (1,5-AG) levels were associated with a decreasing trend in pancreatic cancer risk (OR of quartile 4 [Q4], 0.50; 95% CI, 0.27-0.93; P = .02). Increasing methionine levels were also associated with an increasing trend of pancreatic cancer risk (OR of Q4, 1.79; 95% CI, 0.94-3.40: P = .03). Additional adjustment for potential confounders attenuated the observed associations of 1,5-AG and methionine (P for trend = .06 and .07, respectively). Comparing subjects diagnosed in the first 0-6 years, higher levels of 1,5-AG, asparagine, tyrosine and uric acid showed a decreasing trend for pancreatic cancer risk (P for trend = .04, .04, .04 and .02, respectively), even after adjustment for potential confounders. We found that the 12 target metabolites were not associated with pancreatic cancer risk. However, metabolic changes in the subjects diagnosed in the first 0-6 years showed a similar tendency to our previous reports. These results might suggest that these metabolites are useful for early detection but not for prediction of pancreatic cancer.

BACKGROUND AND AIMS: Proton pump inhibitors (PPIs) are among the most frequently prescribed medications. Side effects including an increased risk of intestinal infections have been reported. It is assumed that PPIs can increase susceptibility to enteropathogens; however, the underlying mechanisms are unknown. Here in this study, we explored whether Lansoprazole (Laz), one of the PPIs, increases the susceptibility to enteropathogens, and further investigated the mechanism of it. METHODS: Mice were administered Laz intraperitoneally once daily and orally infected with Citrobacter rodentium (C. rodentium). The establishment of intestinal infection was assessed by histology and inflammatory cytokine expression levels measured by quantitative PCR. To test whether Laz changes the intestinal environment to influence the susceptibility, intestinal pH, microbiota, metabolites and immune cell distributions were evaluated via pH measurement, 16S rRNA gene sequencing, metabolome, and flow cytometry analyses after Laz administration. RESULTS: Colitis was induced with less C. rodentium in Laz-treated mice as compared with the controls. We found that increased numbers of C. rodentium could reach the cecum following Laz administration. Laz increased pH in the stomach but not in the intestines. It induced dysbiosis and changed the metabolite content of the small intestine. However, these changes did not lead to alterations of immune cell distribution. CONCLUSIONS: Laz raised susceptibility to C. rodentium as increased numbers of the pathogen reach the site of infection. Our results suggest that it was due to increased stomach pH which allowed more peroral enteropathogens to pass the stomach, but not because of changes of intestinal environment.

Recently, apolipoprotein A2 (apoA2) isoforms have been reported as candidate serum/plasma biomarkers of pancreatic cancer. However, the distribution of apoA2 isoforms in patients with autoimmune pancreatitis (AIP) has not been investigated yet. In this study, we evaluated the distribution of serum apoA2 isoforms; i.e., homodimer apoA2-ATQ/ATQ, heterodimer apoA2-ATQ/AT, and homodimer apoA2-AT/AT, in AIP patients and healthy volunteers (HV) using enzyme-linked immunosorbent assays, and the clinical characteristics and serum levels of each apoA2 isoform in 32 AIP patients and 38 HV were investigated. The calculated apoA2-ATQ/AT levels of the AIP patients were significantly lower than those of the HV, which agreed with results obtained for patients with pancreatic cancer. Interestingly, most of the AIP patients exhibited high levels of apoA2-ATQ along with low levels of apoA2-AT, indicating that the processing of the C-terminal regions of apoA2 dimer was inhibited in the AIP patients. This specific distribution of serum apoA2 isoforms might provide important information about the disease states of AIP patients and aid the differential diagnosis of AIP versus pancreatic cancer.

BACKGROUND: Aluminum (Al) is considered to be a neurotoxic metal, and excessive exposure to Al has been reported to be a potential risk factor for neurodegenerative diseases. Al ammonium sulfate is one of the Al compounds that is widely used as a food additive. However, the effects of the oral administration of Al ammonium sulfate on physical development and behavior remain to be examined. METHODS: In this study, we investigated the effects of the administration of Al ammonium sulfate 12-water dissolved in drinking water (0.075 mg/mL) beginning in adolescence on various types of behavior in adult female C57BL/6J mice through a battery of behavioral tests (low-dose experiment; Experiment 1). We further examined the behavioral effects of the oral administration of a higher dose of the Al compound in drinking water (1 mg/mL) beginning in the prenatal period on behavior in adult male and female mice (high-dose experiment; Experiment 2). RESULTS: In the low-dose experiment, in which females' oral intake of Al was estimated to be 0.97 mg Al/kg/d as adults, Al-treated females exhibited an increase in total arm entries in the elevated plus maze test, an initial decrease and subsequent increase in immobility in the forced swim test, and reduced freezing in the fear conditioning test approximately 1 month after the conditioning session compared with vehicle-treated females (uncorrected P < .05). However, the behavioral differences did not reach a statistically significant level after correction for multiple testing. In the high-dose experiment, in which animals' oral intakes were estimated to be about ten times higher than those in the low-dose experiment, behavioral differences found in the low-dose experiment were not observed in high-dose Al-treated mice, suggesting that the results of the low-dose experiment might be false positives. Additionally, although high-dose Al-treated females exhibited increased social contacts with unfamiliar conspecifics and impaired reference memory performance, and high-dose Al-treated mice exhibited decreases in prepulse inhibition and in correct responses in the working memory task (uncorrected P < .05), the differences in any of the behavioral measures did not reach the significance level after correction for multiple testing. CONCLUSION: Our results show that long-term oral exposure to Al ammonium sulfate at the doses used in this study may have the potential to induce some behavioral changes in C57BL/6J mice. However, the behavioral effects of Al were small and statistically weak, as indicated by the fact that the results failed to reach the study-wide significance level. Thus, further study will be needed to replicate the results and reevaluate the behavioral outcomes of oral intake of Al ammonium sulfate.

Background: Hepatocellular carcinoma (HCC) can develop in patients who are negative for the hepatitis B surface antigen (HBsAg) in serum but positive for hepatitis B virus (HBV) DNA in the liver, referred to as occult HBV infection (OBI). Previous reports showed that HBV variants in OBI-related HCC are different from those in HBsAg-positive HCC. In the present study, HBV quasispecies based on the pre-S/S gene in OBI-related HCC patients were examined by high throughput sequencing and compared with those in HBsAg-positive HCC. Methods: Nineteen tissue samples (9 OBI-related and 10 HBsAg-positive non-cancerous tissues) were collected at the time of surgery at Kobe University Hospital. The quasispecies with more than 1% variation in the pre-S/S region were isolated and analysed by ultra-deep sequencing. Results: There were no significant differences in the major HBV populations, which exhibit more than 20% variation within the entire pre-S/S region, between OBI-related HCC and HBsAg-positive HCC. However, the prevalences of major populations with pre-S2 region mutations and of minor populations with polymerized human serum albumin-binding domain mutations were significantly higher in OBI-related HCC than in HBsAg-positive HCC. Moreover, the major variant populations associated with the B-cell epitope, located within the pre-S1 region, and the a determinant domain, located in the S region, were detected frequently in HBsAg-positive HCC. The minor populations of variants harbouring the W4R, L30S, Q118R/Stop, N123D and S124F/P mutations in the pre-S region and the L21F/S and L42F/S mutations in the S region were detected more frequently in OBI-related HCC than in HBsAg-positive HCC. Conclusions: Ultra-deep sequencing revealed that the B-cell epitope domain in the pre-S1 region and alpha determinant domain in the S region were variable in HBsAg-positive HCC, although the quasispecies associated with the pre-S2 region were highly prevalent in OBI-related HCC. Trial registration: Ref: R000034382/UMIN000030113; Retrospectively registered 25 November 2017.

BACKGROUND: We aimed to clarify the factors associated with the presentation of erosive esophagitis (EE) symptoms in subjects undergoing health checkups. METHODS: We utilized baseline data from 7,552 subjects who underwent upper endoscopy for health screening in a prospective, multicenter cohort study. The subjects were asked to complete a questionnaire detailing their upper abdominal symptoms and lifestyle. Based on the heartburn and/or acid regurgitation frequency, the EE subjects were stratified into the following three groups: (1) at least one day a week (symptomatic EE [sEE]), (2) less than one day a week (mild symptomatic EE [msEE]), and (3) never (asymptomatic EE [aEE]). Postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) were defined according to the Rome III criteria. RESULTS: Of the 1,262 (16.7%) subjects (male 83.8%, mean age 52.6 years) with EE, the proportions of sEE, msEE and aEE were 15.0%, 37.2% and 47.9%, respectively. The sEE group showed significant associations with overlapping EPS (OR: 58.4, 95% CI: 25.2-160.0), overlapping PDS (OR: 9.96, 95% CI: 3.91-26.8), severe hiatal hernia (OR: 2.43, 95% CI: 1.43-4.05), experiencing high levels of stress (OR: 2.20, 95% CI: 1.43-3.40), atrophic gastritis (OR: 1.57, 95% CI: 1.03-2.36) and Los Angeles (LA) grade B or worse (OR: 1.72, 95% CI: 1.12-2.60) in the multivariate analysis. CONCLUSIONS: Approximately one-sixth of EE subjects were symptomatic. A multifactorial etiology, including factors unrelated to gastric acid secretion, was associated with the symptom presentation of EE subjects.

BACKGROUND: Inflammation-induced carcinogenesis in pancreatic ductal adenocarcinoma (PDAC) has been reported; however, its involvement in PDAC with intraductal papillary mucinous neoplasm (IPMN) remains unclear. We herein investigated the relationship between pancreatic atrophy and inflammation and the incidence of PDAC concomitant with IPMN. METHODS: This study included 178 consecutive patients who underwent surgical resection for PDAC with IPMN (N = 21) and IPMN (N = 157) between April 2001 and October 2016. A multivariable logistic regression analysis was conducted to assess the relationship between pancreatic inflammation and atrophy and the incidence of PDAC concomitant with IPMN, with adjustments for clinical characteristics and imaging features. Pathological pancreatic inflammation and atrophy were evaluated in resected specimens. RESULTS: High degrees of pancreatic inflammation and atrophy were not associated with the incidence of PDAC with IPMN (multivariable odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.07 to 3.33, P = .52, adjusted by clinical characteristics, OR = 0.9, 95% CI = 0.10 to 5.86, P = .91, adjusted by imaging studies; OR = 0.2, 95% CI = 0.009 to 1.31, P = .10, adjusted by clinical characteristics, OR = 0.2, 95% CI = 0.01 to 1.43, P = .12, adjusted by imaging studies, respectively). CONCLUSIONS: Pancreatic inflammation and atrophy were not associated with pancreatic cancer concomitant with IPMN.

Helicobacter pylori, which is involved in the pathogenesis of gastroduodenal disease, produces CagA and VacA as major virulence factors. CagA is classified into East Asian and Western types based on the number and sequences of its Glu-Pro-Ile-Tyr-Ala motifs. The vacA gene has three polymorphic regions: the signal (s), intermediate (i), and middle (m) regions. The lowest gastric cancer mortality rate is seen in Okinawa. On the Japanese mainland (Honshu), most H. pylori produce s1/m1-VacA, which exhibits strong toxicity, and East Asian-type CagA. However, the H. pylori detected in Okinawa produces s1/m2-VacA, which exhibits weak toxicity, or s2/m2-VacA, which is non-toxic, and Western-type CagA. Studies about the i-region of vacA have been performed around the world, but there have been few such studies in Japan. Therefore, the aim of this study was to assess the relationships between the clinical outcomes of H. pylori infections in Okinawa, vacA (especially the i-region genotype), and cagA. H. pylori strains that were collected from patients with gastric cancer or gastric ulcers in Okinawa only produced the i1-type VacA virulence factor. The vacuolating cytotoxin activity of i1-type VacA was stronger than that of i2-type VacA, suggesting that the i-region genotype of vacA is closely associated with vacuolating cytotoxin activity. These results indicate that the i-region genotype of vacA is a useful marker of both H. pylori virulence and the clinical outcomes of H. pylori infections in Okinawa, Japan.

Cisplatin, which is an inorganic molecule containing a platinum ion, is an antineoplastic agent that has been used to treat various solid tumors. However, its side effects include nephrotoxicity, neurotoxicity, bone marrow toxicity, gastrointestinal toxicity, and ototoxicity, which can limit its use. In this study, nephrotoxicity was caused by the intraperitoneal injection of cisplatin into rats, and then metabolome analysis was performed using gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) to find plasma metabolite biomarker candidates that would facilitate the early detection of cisplatin-induced nephrotoxicity. As a result, chronological changes were detected in the plasma levels of cysteine-cystine and 3-hydroxy-butyrate in the GC/MS-based metabolomics study. In the LC/MS-based metabolomics study, 3 acylcarnitines and a phosphatidylethanolamine with C18:2-C18:2 were identified as potential plasma biomarkers of cisplatin-induced nephrotoxicity. The plasma levels of these 6 metabolites altered significantly after the administration of cisplatin, and these alterations occurred quicker than the equivalent changes in the plasma levels of creatinine and blood urea nitrogen, which are usually used as indicators of renal dysfunction. These results indicate that the abovementioned metabolites might be reliable biomarkers that would allow the earlier detection of cisplatin-induced nephrotoxicity and that metabolomics is a useful tool for discovering biomarkers that could be used to predict the side effects of cancer therapy.

Herbal medicines and natural products used for maintenance of health or treatment of diseases have many biological effects, including altering the pharmacokinetics and metabolism of other medications. Daikenchuto (TU-100), an aqueous extract of ginger, ginseng, and Japanese green pepper fruit, is a commonly prescribed Kampo (Japanese herbal medicine) for postoperative ileus or bloating. The effects of TU-100 on drug metabolism have not been investigated. In this study, we analyzed the effect of TU-100 on expression of key drug-metabolizing enzymes (DMEs) and drug transporters (DTs) in murine liver and gastrointestinal tract using a dietary model. Liver, jejunum, and proximal colon were analyzed for phase I and II DMEs and DT mRNA expression by reverse transcription (RT) first by nonquantitative and followed by quantitative polymerase chain reaction (PCR) and protein expression. Liver, jejunum, and proximal colon expressed some identical but also unique DMEs and DTs. TU-100 increased the greatest changes in cytochrome (Cyp) 2b10 and Cyp3a11 and Mdr1a. Basal and TU-100 stimulated levels of DME and DT expression were gender-dependent, dose-dependent and reversible after cessation of TU-100 supplementation, except for some changes in the intestine. Quantitative Western blot analysis of protein extracts confirmed the quantitative PCR results.

RATIONALE: The analytical stability and throughput of biomarker assays based on dried serum spots (DSS) are strongly dependent on the extraction process and determination method. In the present study, an on-line system based on supercritical fluid extraction-supercritical fluid chromatography coupled with tandem mass spectrometry (SFE-SFC/MS/MS) was established for analyzing the levels of disease biomarkers in DSS. METHODS: The chromatographic conditions were investigated using the ODS-EP, diol, and SIL-100A columns. Then, we optimized the SFE-SFC/MS/MS method using the diol column, focusing on candidate biomarkers of oral, colorectal, and pancreatic cancer that were identified using liquid chromatography (LC)/MS/MS. RESULTS: By using this system, four hydrophilic metabolites and 17 hydrophobic metabolites were simultaneously detected within 15 min. In an experiment involving clinical samples, PC 16:0-18:2/16:1-18:1 exhibited 93.8% sensitivity and 64.3% specificity, whereas PC 17:1-18:1/17:0-18:2 showed 81.3% sensitivity and 92.9% specificity for detecting oral cancer. In addition, assessments of the creatine levels demonstrated 92.3% sensitivity and 78.6% specificity for detecting colorectal cancer. CONCLUSIONS: The results of this study indicate that our method has great potential for clinical diagnosis and would be suitable for large-scale screening. Copyright © 2017 John Wiley & Sons, Ltd.

BACKGROUND: To improve prognosis of pancreatic cancer (PC) patients, the discovery of more reliable biomarkers for the early detection is desired. METHODS: Blood samples were collected by 2 independent groups. The 1st set was included 55 early PC and 58 healthy volunteers (HV), and the 2nd set was included 16 PC and 16HV. The 16 targeted metabolites were quantitatively analyzed by gas chromatography/tandem mass spectrometry together with their corresponding stable isotopes. In the 1st set, the levels of these metabolites were evaluated, and diagnostic models were constructed via multivariate logistic regression analysis, leading to validation using the 2nd set. RESULTS: In the 1st set, model X consisting of 4 candidates based on our previous report possessed higher sensitivity (74.1%) than carbohydrate antigen 19-9 (CA19-9). Model Y, consisting of 2 metabolites newly selected from 16 metabolites via stepwise method possessed higher sensitivity (70.4%) than CA19-9. Furthermore, combining model Y with CA19-9 increased its sensitivity (90.7%) and specificity (89.5%). In the 2nd set, combining model Y with CA19-9 displayed high sensitivity (81.3%) and specificity (93.8%). In particular, it displayed very high sensitivity (100%) for resectable PC. CONCLUSIONS: Quantitative analysis confirmed that metabolomics-based diagnostic methods are useful for detecting PC early.

OBJECTIVES: The effect of smoking status on the incidence of pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN) has not been clarified. This study investigated the association of smoking status with PDAC concomitant with IPMN. METHODS: The subjects were 124 consecutive patients undergoing resection of IPMNs (intraductal papillary mucinous adenoma (IPMA): N = 77, invasive IPMN: N = 31, and PDAC with IPMN: N = 16) between April 2008 and October 2015. The associations between smoking status (never/former/current smoker) or cumulative pack-years (0-19/20-39/≥40) and the incidence of PDAC concomitant with IPMN or invasive IPMN were evaluated. RESULTS: Current smoking, not former smoking, was associated with the incidence of PDAC concomitant with IPMN (PDAC with IPMN vs IPMN alone; P = 0.004, PDAC with IPMN vs IPMA; P = 0.004, PDAC with IPMN vs invasive IPMN; P = 0.04, respectively), but not that of invasive IPMN (invasive IPMN vs IPMA; P = 0.85). Cumulative pack-years were higher in patients who had PDAC concomitant with IPMN than in patients with invasive IPMN (P = 0.04). Cumulative pack-years were not associated with smoking status (current vs former). CONCLUSIONS: Current smoking, not former smoking, was associated with the incidence of PDAC concomitant with IPMN. Cessation of smoking may be recommended for patients with IPMN.

AIM: To elucidate the factors associated with residual gastroesophageal reflux disease (GERD) symptoms in patients receiving proton pump inhibitor (PPI) maintenance therapy in clinical practice. METHODS: The study included 39 GERD patients receiving maintenance PPI therapy. Residual symptoms were assessed using the Frequency Scale for Symptoms of GERD (FSSG) questionnaire and the Gastrointestinal Symptom Rating Scale (GSRS). The relationships between the FSSG score and patient background factors, including the CYP2C19 genotype, were analyzed. RESULTS: The FSSG scores ranged from 1 to 28 points (median score: 7.5 points), and 19 patients (48.7%) had a score of 8 points or more. The patients' GSRS scores were significantly correlated with their FSSG scores (correlation coefficient = 0.47, P < 0.005). In erosive esophagitis patients, the FSSG scores of the CYP2C19 rapid metabolizers (RMs) were significantly higher than the scores of the poor metabolizers and intermediate metabolizers (total scores: 16.7 ± 8.6 vs 7.8 ± 5.4, P < 0.05; acid reflux-related symptom scores: 12 ± 1.9 vs 2.5 ± 0.8, P < 0.005). In contrast, the FSSG scores of the CYP2C19 RMs in the non-erosive reflux disease patients were significantly lower than those of the other patients (total scores: 5.5 ± 1.0 vs 11.8 ± 6.3, P < 0.05; dysmotility symptom-related scores: 1.0 ± 0.4 vs 6.0 ± 0.8, P < 0.01). CONCLUSION: Approximately half of the GERD patients receiving maintenance PPI therapy had residual symptoms associated with a lower quality of life, and the CYP2C19 genotype appeared to be associated with these residual symptoms.

In developed countries, the number of patients with colorectal cancer has been increasing, and colorectal cancer is one of the most common causes of cancer death. To improve the quality of life of colorectal cancer patients, it is necessary to establish novel screening methods that would allow early detection of colorectal cancer. We performed metabolome analysis of a plasma sample set from 282 stage 0/I/II colorectal cancer patients and 291 healthy volunteers using gas chromatography/triple-quadrupole mass spectrometry in an attempt to identify metabolite biomarkers of stage 0/I/II colorectal cancer. The colorectal cancer patients included patients with stage 0 (N=79), I (N=80), and II (N=123) in whom invasion and metastasis were absent. Our analytical system detected 64 metabolites in the plasma samples, and the levels of 29 metabolites differed significantly (Bonferroni-corrected p=0.000781) between the patients and healthy volunteers. Based on these results, a multiple logistic regression analysis of various metabolite biomarkers was carried out, and a stage 0/I/II colorectal cancer prediction model was established. The area under the curve, sensitivity, and specificity values of this model for detecting stage 0/I/II colorectal cancer were 0.996, 99.3%, and 93.8%, respectively. The model's sensitivity and specificity values for each disease stage were >90%, and surprisingly, its sensitivity for stage 0, specificity for stage 0, and sensitivity for stage II disease were all 100%. Our predictive model can aid early detection of colorectal cancer and has potential as a novel screening test for cases of colorectal cancer that do not involve lymph node or distant metastasis.

Decoding of closely related genomes is now revealing the process of population evolution. In bacteria, population divergence appears associated with a unique set of sequence-specific epigenetic DNA methylation systems, often within restriction-modification (RM) systems. They might define a unique gene expression pattern and limit genetic flux between lineages in population divergence. We addressed the contribution of methylation systems to population diversification in panmictic bacterial species, Helicobacter pylori, which shows an interconnected population structure through frequent mutual recombination. We analyzed complete genome sequences of 28 strains collected in Fukui, Japan. Their nucleotide sequences are closely related although fine-scale analyses revealed two subgroups likely reflecting human subpopulations. Their sequences are tightly connected by homologous recombination. Our extensive analysis of RM systems revealed an extreme variability in DNA methyltransferases, especially in their target recognition domains. Their diversity was, however, not immediately related to the genome sequence diversity, except for very closely related strains. An interesting exception is a hybrid strain, which likely has conserved the methylation gene repertoire from one parent but diversified in sequence by massive acquisition of fragmentary DNA sequences from the other parent. Our results demonstrate how a bacterial population can be extremely divergent in epigenetics and yet homogenized in sequence.

We describe the application of photodetachable and recyclable dispersants for single-walled carbon nanotubes (SWNTs) in the fabrication of photopatterned SWNT thin films. Because adsorption and desorption of the dispersants on the SWNT surfaces affect not only their dispersibility in water but also their solubility, SWNT photopatterns were obtained on glass substrates in only three steps, i.e., casting the SWNT/dispersant solution, UV-light exposure of the casted SWNT/dispersant films through a photomask, and subsequent rinsing with neutral water. This patterning procedure is simple and scalable and will enable us to prepare microfabricated SWNT thin films.