Search

We experimentally evaluate the electrical properties of carbon nanotube (CNT)-network transistors before and after 60 Co gamma-ray irradiation up to 50 kGy in an air environment. When the total dose is increased, the degree of the threshold voltage ( V th ) shift towards positive gate voltages in the drain current–gate voltage ( I D – V GS ) characteristics decreases for total irradiation doses above 30 kGy, although it is constant below 30 kGy. From our analysis of the I D – V GS characteristics along with micro-Raman spectroscopy, the gamma-ray irradiation does not change the structure of the CNT network channel for total doses up to 50 kGy; it instead generates charge traps near the CNT/SiO 2 gate insulator interfaces. These traps are located within the SiO 2 layer and/or the adsorbate on the device surface. The positively charged traps near the CNT/SiO 2 interface contribute less to the V th shift than the interface dipoles at the CNT/metal electrode interfaces and the segment of the CNT network channel below doses of 30 kGy, while the contribution of the charge traps increases for total doses above 30 kGy. Our findings indicate the possibility of the application of CNT-network transistors as radiation detectors suitable for use in air for radiation doses above 30 kGy.

Our study investigated the relationship between gastric cancer development and activity of Helicobacter pylori-associated chronic gastritis or the resulting chronic atrophic gastritis (CAG). A cohort of 4,655 healthy asymptomatic subjects, in whom serum pepsinogen (PG) and H. pylori antibody titer had been measured to assess the activity and stage of H. pylori-associated chronic gastritis, was followed for up to 16 years, and cancer development was investigated. In subjects with a serologically diagnosed healthy stomach (H. pylori-negative/CAG-negative), cancer incidence rate was low, at 16/100,000 person-years. With the establishment of H. pylori infection and progression of chronic gastritis, significant stepwise cancer risk elevations were seen from CAG-free subjects (H. pylori-positive/CAG-negative) [hazard ratio (HR) = 8.9, 95% confidence interval (CI) = 2.7-54.7] to subjects with CAG (H. pylori-positive/CAG-positive) (HR = 17.7, 95% CI = 5.4-108.6) and finally to subjects with metaplastic gastritis (H. pylori-negative/CAG-positive) (HR = 69.7, 95% CI = 13.6-502.9). In H. pylori-infected CAG-free subjects, significantly elevated cancer risk was observed in the subgroup with active inflammation-based high PG II level or potent immune response-based high H. pylori antibody titer; the former was associated with a particularly high risk of diffuse-type cancer, and both subgroups showed high cancer incidence rates of around 250/100,000 person-years, comparable to that in subjects with CAG. No such risk elevation was observed in H. pylori-infected subjects with CAG. These results clearly indicate that gastric cancer develops mainly from the gastritis-atrophy-metaplasia-cancer sequence and partly from active inflammation-based direct carcinogenesis, and that serum levels of PG and H. pylori antibody titer provide indices of cancer development in H. pylori-infected subjects.

Hepatocellular carcinoma (HCC) frequently develops in cirrhotic liver and is one of the most common malignancies worldwide. The tumor volume doubling time (TVDT) reflects the natural tumor growth rate and is an indicator of the biological malignant potential of a tumor. The present study aimed to elucidate the association between the serological and histological indices of HCC and TVDT. TVDT was analyzed for 53 HCCs by measuring the enlargement of the tumor diameter on dynamic computed tomography. Differences in TVDT were compared among histological grades of HCC differentiation. The α-fetoprotein (AFP) doubling time (T2AFP) for 44 HCCs with AFP levels >200 ng/ml was calculated and the differences in T2AFP were compared according to the histological grade of HCC differentiation and positivity for Lens culinaris agglutinin-reactive fraction of α-fetoprotein (AFP-L3). Among these 44 HCCs, the correlation between T2AFP and TVDT was analyzed for the 27 tumors for which TVDT could be calculated. The mean ± standard deviation (SD) TVDT in Edmondson grade 1 (Ed1), Ed2 and Ed3 HCC was 138.3±110.3, 94.9±91.5 and 32.2±20.8 days, respectively (P

Background No mouthpiece has been designed to control salivary flow during endoscopic procedures. A new continuous suction mouthpiece (CSM) was developed, and its usefulness for percutaneous endoscopic gastrostomy (PEG) was evaluated. Patients and Methods Seventy-two patients who were scheduled to undergo PEG or the exchange of a gastrostomy button or tube were assigned to one of two groups: the group using the CSM and the group using the conventional mouthpiece. Aspiration pneumonia, procedure duration, extent of salivary flow, frequency of saliva suction, and number of choking episodes during the procedures were evaluated and compared between the two groups. Results The same number of patients was randomly allocated to each group. There were no significant differences between the two groups in sex, age, procedure type, duration of procedure,depth of sedation, and indication for the procedure. The grade of salivary flow was significantly lower in patients with the CSM than in patients with the conventional mouthpiece (P

In a previous population-based case-control study, we demonstrated an elevated risk of colorectal neoplasia with Helicobacter pylori (H. pylori) infection. The present study investigated the effects of H. pylori-associated chronic gastritis on the development of colorectal neoplasia by analyzing the recurrence of colorectal neoplasia subsequent to endoscopic resection. Ninety-nine patients who had undergone endoscopic resection of colorectal neoplasia were monitored under colonoscopy, and the recurrence of colorectal neoplasia was prospectively investigated. The stage of H. pylori-associated chronic gastritis in each subject was evaluated using a combination of two serum tests: H. pylori antibody and pepsinogen. In the present cohort, colorectal neoplasia recurred at a rate of 15,296/100,000 person-years during the study period. After adjusting for the confounding factors, chronic atrophic gastritis (CAG) was identified as an independent risk factor [adjusted hazard ratio (HR), 2.72; 95% confidence interval, 1.33-5.57], while H. pylori-infected non-atrophic gastritis was not identified as an independent risk factor for recurrent colorectal neoplasia. Colorectal neoplasia recurred earlier and was significantly more frequent in patients with CAG (22,573/100,000 person-years) compared to patients without CAG (11,089/100,000 person-years; P=0.029, log-rank test). Patients with more extensive CAG showed a higher risk of recurrence. These results demonstrated a significant elevation of the risk of recurrent colorectal neoplasia with the establishment and progression of CAG, indicating the involvement of H. pylori infection in the development of colorectal neoplasia. The two serum tests were useful clinical markers for noninvasively evaluating the risk of each individual for recurrent colorectal neoplasia subsequent to endoscopic resection.

Aim: Although frequent vomiting reflexes during esophagogastroduodenoscopy (EGD) causes suffering in patients, very few studies have investigated the characteristics of subjects who frequently develop vomiting reflexes. This study examined the incidence of the vomiting reflex and related factors, especially upper gastrointestinal symptoms, among individuals undergoing transoral EGD. Methods: Subjects included 488 consecutive adults (mean age, 56.1 ± 8.9 years) who underwent transoral EGD for gastric cancer screening between February 2010 and March 2011. All procedures were performed by an endoscopist with 15 years of experience. Based on a questionnaire survey using the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), symptoms (dyspepsia and acid reflux symptoms) and the number of vomiting reflexes during EGD were recorded. Results: Of the 488 subjects, 271 (56%) developed vomiting reflexes (mean, 4.2 times). This reflex-positive group was younger (54.3 ± 9.5 years) than the reflex-negative group (58.3 ± 7.7 years, P

Aim: Continuation of pegylated interferon (PEG-IFN) plus ribavirin at the recommended dose is difficult in elderly patients and/or patients with cytopenia or complications. Whether the therapeutic efficacy of low-dose PEG-IFN plus ribavirin therapy could be predicted based on virological response within 2 weeks of therapy initiation was evaluated. Methods: A total of 106 patients with a high viral load of genotype-1b hepatitis C virus (HCV) underwent low-dose PEG-IFN plus ribavirin therapy. PEG-IFN alpha 2b (0.75 µg/kg per week) and ribavirin (600–800 mg/day) were administered for 48 weeks. Results: Sustained virological response (SVR) was achieved in 37%, and treatment was discontinued in 9%. On univariate analysis of SVR-contributing factors, significant differences were noted in the white blood cell count, platelet count, fibrosis markers, and viral reduction within 2 weeks from therapy initiation. On multivariate analysis, the platelet count and the reduction in the HCV core antigen level at week 2 were independent factors. The positive predictive value (PPV) and the negative predictive value (NPV) for SVR based on a 1-log or greater HCV-RNA level reduction at week 2 were 65% and 90%, respectively, and those based on HCV core antigen level at week 2 were 64% and 97%, respectively. PPV and NPV based on a 2-log or greater reduction of the RNA level were 86% and 67%, respectively, and those based on the core antigen level were 93% and 69%, respectively. Conclusion: Evaluation of viral reduction at week 2 after therapy initiation is useful for predicting SVR to low-dose PEG-IFN plus ribavirin therapy.

Aim: To clarify the clinical features of and risk factors for extrahepatic seeding, a major complication following radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). Methods: Our prospective database of 351 nodules in 257 patients with HCC who had undergone RFA between April 2001 and April 2008 was reviewed. The following variables were assessed to identify the risk factors for extrahepatic seeding: age, sex, viral markers, Child–Pugh class, tumor size, number of tumors, RFA indication (tumor size ≤3 cm, number of tumors ≤3), tumor biopsy prior to RFA, degree of histological differentiation, tumor markers, tumor location, number of sessions, and combined transcatheter arterial chemoembolization. Results: The median follow-up period was 36.5 months, during which the rate of seeding after was 5.1% and the 5-year cumulative seeding rate was 8.4%. The survival rate after neoplastic seeding was 21% at 5 years. Univariate analysis of the risk factors for neoplastic seeding showed significant differences in tumor size, RFA indication, subcapsular lesion, number of sessions, tumor biopsy prior to RFA, and des-gamma-carboxy prothrombin value. However, multivariate analysis showed that the only independent risk factor was RFA indication. Conclusions: The prognosis of patients with neoplastic seeding was poor. In particular, RFA performed for HCC not satisfying the RFA indication showed a high risk of seeding, and careful consideration should be given to the optimal treatment method and avoiding direct puncture of subcapsular tumors.

AIM Evaluation of malignant potential is important to determine the treatment strategy for small hepatocellular carcinoma (HCC). The aim of the present study was to establish a method of assessing the malignant potential of small hypervascular HCC using B-mode ultrasonography. METHODS One hundred and thirteen arterial hypervascular HCC nodules under 3 cm diagnosed by biopsy or surgical resection (20.5 ± 6.3 mm) were classified into two groups ultrasonographically: type 1 with (n = 27) and type 2 without (n = 86) a halo. Type 2 was categorized into three subgroups: type 2a, homogenous hyperechoic (n = 9); type 2b, hypoechoic with a smooth margin (n = 35); and type 2c, hypoechoic with an irregular or unclear margin (n = 42). RESULTS The mean diameter of type 2a nodules was significantly smaller than that of other HCC types (P

To establish a method of assessing the malignant potential of hepatocellular carcinoma (HCC) using magnetic resonance imaging (MRI).For 69 nodules [12 Edmondson (Ed)-I, 48 Ed-II, 9 Ed-III] in 54 HCC patients, signal intensity patterns and enhancement patterns of gadopentate dimeglumine (Gd-DTPA) dynamic studies were correlated with histological differentiation and serum lens culinaris agglutinin-reactive alpha-fetoprotein (AFP-L3) level, which is an indicator of poor prognosis.Hypointensity on T1-weighted imaging was seen in 17, 72, and 89% of Ed-I, Ed-II, and Ed-III HCCs, respectively (P 0.001). Meanwhile, hyperintensity on T2-weighted imaging was seen in 42, 88, and 89% (P 0.005). Tumor stain during the arterial phase of Gd dynamic MRI was seen in 75, 86, and 89%. Tumor stain washout during the portal phase was seen in 43% of Ed-II and 100% of Ed-III HCCs (P 0.005). In the Ed-II and Ed-III HCCs, hypointensity on T1-weighted imaging was seen in 65% of AFP-L3-negative HCCs and 90% of AFP-L3-positive HCCs (P = 0.071). Washout of tumor stain during the portal phase was seen in 39% of AFP-L3-negative HCCs and 75% of AFP-L3-positive HCCs (P 0.05).Although hyperintensity of tumor on T2-weighted imaging and arterial hypervascularity of tumor are considered to be useful for differential diagnosis between well differentiated HCCs and moderately/poorly differentiated HCCs, hypointensity of tumor on T1-weighted imaging and tumor stain washout during the portal phase of Gd-DTPA dynamic MRI reflected poorer histological differentiation of HCCs and correlated with AFP-L3 levels.

Two patients developed segmental, diffuse intrahepatic recurrence after percutaneous radiofrequency ablation (RFA) to treat a primary, solitary, and small (2.5 cm) hepatocellular carcinoma (HCC). Despite the size of the HCC, levels of the tumor markers (α-fetoprotein, α-fetoprotein-L3%, and des-γ-carboxyprothrombin) were all elevated before RFA, and tumors in both patients were contiguous with a major branch of the portal vein. Tumor biopsies of both patients revealed moderately differentiated HCC but diagnostic imaging showed an area of reduced tumor blood flow, suggesting a poorly differentiated component. Since early detection of post-RFA malignancies by standard ultrasonography and contrast-enhanced computed tomography was difficult, the most sensitive indicator of recurrence in these two patients was the elevated tumor markers. The diffuse intrahepatic recurrence was thought to be caused by increased intratumoral pressure during RFA, resulting in the dissemination of cancer cells through the contiguous portal vein. The clinical course of these tumors indicate that the choice of RFA should be carefully considered when treating specific subtype of HCC that is adjacent to main portal vein branch and involves a possible poorly differentiated component and that surgical resection or combinations of RFA with other treatment modalities such as transcatheter arterial chemoembolization should be considered as alternative treatment strategies.

To clarify the alterations in lower intestinal microflora induced by gastric acid reduction, the dynamics of 12 major genera or groups of bacteria comprising the microflora in feces and colonic contents were examined by quantitative real-time PCR in proton pump inhibitor-treated rats and in asymptomatic human subjects with hypochlorhydria. In both rat and human experiments, most genera or groups of intestinal microflora (facultative and obligate anaerobes) proliferated by gastric acid reduction, and marked and significant increases in the Lactobacilli group and Veillonella, oropharyngeal bacteria, were observed. In rats, potent gastric acid inhibition led to a marked and significant increase of intestinal bacteria, including the Bacteroidesfragilis group, while Bifidobacterium, a beneficial bacterial species, remained at a constant level. These results strongly indicate that the gastric acid barrier not only controls the colonization and growth of oropharyngeal bacteria, but also regulates the population and composition of lower intestinal microflora.

A total of 5,209 asymptomatic, middle-aged subjects, whose serum pepsinogen (PG) and Helicobacter pylori antibody levels had been assessed, were followed for 10 years. Subjects with positive serum H. pylori antibodies (>50 U/mL) had an increased cancer risk (HR = 3.48, 95% CI = 1.26–9.64). Risk of gastric cancer increased as the antibody level increased; the H. pylori-positive group with antibody levels >500 U/mL had the highest incidence rate (325/100,000 person-years). Cancer development also increased with a reduced serum PG I level or a reduced PG I/II ratio; the risk was significantly elevated with serum PG I level ≤30 ng/mL (HR = 3.54, 95% CI = 1.95–6.40) or PG I/II ratio ≤3.0 (HR = 4.25, 95% CI = 2.47–7.32). Furthermore, the risk of diffuse-type cancer increased as PG II level increased; it was significantly elevated with PG II level ≥30 ng/mL (HR = 3.81, 95% CI = 1.10–13.21). Using H. pylori antibody and PG levels, subgroups with an especially high or low cancer incidence rate could be identified. H. pylori-negative or indeterminate subjects with low PG level (PG I ≤30 ng/mL or PG I/II ratio ≤2.0) or H. pylori-positive subjects with antibody levels >500 U/mL and a low PG level were among the subgroups with a high cancer incidence rate (over 400/100,000 person-years). In contrast, H. pylori-negative subjects with a PG I level >70 ng/mL or a PG I/II ratio >3.0 had the lowest risk; none of these subjects developed cancer. Thus, serum PG levels and/or H. pylori antibody levels can be used to predict the risk of cancer in individuals with H. pylori-related gastritis from the general population. © 2008 Wiley-Liss, Inc.

Background: Gastric cancer screening using the pepsinogen filter test is receiving wide recognition in Japan owing to convenience, freedom from discomfort or risk, efficiency, and economy. Because the long-term outcomes of cancer development in extensive atrophic gastritis detected by pepsinogen test are unclear, test-positive and test-negative subjects were investigated in a longitudinal cohort study. Methods: Subjects comprised 5,209 middle-aged men with measured serum pepsinogen levels who were followed for 10 years. Cancer development based on “atrophy-positive” and “atrophy-negative” criteria used for cancer screening was investigated. Results: During the study, 63 cases of cancer developed in the cohort, representing an incidence rate of 125 per 100,000 person-years. Pepsinogen test screening using the most widely used atrophy-positive criterion (pepsinogen I, ≤70 ng/mL; pepsinogen I/II ratio, ≤3.0) displayed 58.7% sensitivity, 73.4% specificity, and 2.6% positive predictive value. Cancer incidence rate was 276 per 100,000 person-years for the atrophy-positive group and 70 per 100,000 person-years for the atrophy-negative group. Incidence rate was higher in groups fulfilling stricter positive criteria detecting more extensive atrophy, reaching 424 per 100,000 person-years. In addition, 9.2% of atrophy-negative subjects with pepsinogen I of >70 ng/mL and pepsinogen I/II ratio of ≤3.0 (reflecting putative inflammation-based high pepsinogen II level) are at high risk for cancer, particularly diffuse-type cancer, with a cancer incidence rate comparable with atrophy-positive subjects (216 per 100,000 person-years). Conclusion: Atrophy-positive subjects by pepsinogen filter test, particularly those fulfilling stricter criteria, and atrophy-negative subjects with low pepsinogen I/II ratio reflecting putative extensive active inflammation constitute populations at high risk for gastric cancer, requiring thorough endoscopic examination. (Cancer Epidemiol Biomarkers Prev 2008;17(4):838–45)

Cancers arise as a consequence of multiple genetic and epigenetic alterations. Many genes aberrantly methylated in cancers have been identified in recent years, and their use in cancer diagnosis and therapy is currently under investigation. During our genome-wide screening for a novel tumor-suppressor gene in gastric cancers, we found that only a small amount of aberrant methylation was present, even in non-cancerous gastric mucosae. A subsequent large-scale analysis of the gastric mucosae of healthy individuals and gastric cancer patients using quantitative methylation-specific PCR (qMSP) revealed that Helicobacter pylori infection potently induced aberrant DNA methylation in non-cancerous gastric mucosae and that these high methylation levels can decrease following cessation of the H. pylori infection. Helicobacter pylori infection induced the methylation of specific genes among 48 genes that can be methylated in gastric cancer cell lines. Most importantly, the methylation levels in the gastric mucosae of individuals without H. pylori infection correlated with their risk of gastric cancer. These findings show that a field for cancerization is formed by H. pylori infection and that this field can be measured using DNA methylation as a marker. The concept of an "epigenetic field for cancerization" has been also demonstrated for colon and breast cancers, and it is possibly present for other cancers and other diseases. Applied knowledge of epigenetic changes in human diseases has now started to make an impact on the prevention, diagnostics, and therapeutics of these diseases.

Total ionizing dose (TID) effects on carbon nanotube network transistors were experimentally evaluated using 60Co gamma-ray irradiation up to 50 kGy(Si). The electrical characteristics of the devices after irradiation are reported for future space applications., Conference on Radiation Effects on Components and Systems in Moscow

To investigate the effects of Japanese apricot (JA) consumption on gastroesophageal reflux disease (GERD)-related symptoms.Participants included individuals living in Minabe-cho, a well-known JA-growing region, who received specific medical check-ups by the local community health service in 2010. GERD-related symptoms were examined in 1303 Japanese individuals using a validated questionnaire, the Frequency Scale for Symptoms of GERD (FSSG), which consists of 7 questions associated with acid reflux symptoms and 5 questions asking about gastrointestinal dysmotility symptoms. Each question was answered using a 4-point scale, with higher scores indicating more severe GERD-related symptoms. Subjects were divided into two groups according to their intake of dried and pickled JA: daily intake (≥ 1 JA daily) (392 subjects) and none or occasional intake (1 JA daily) (911 subjects). FSSG scores were compared between subjects who consumed JA daily and those who did not. Next, subjects were stratified by age, gender and Helicobacter pylori (H. pylori) status for subanalyses.Those who ate JA daily were significantly older than those who did not (60.6 ± 10.5 years vs 56.0 ± 11.0 years, P0.001). Total FSSG scores were significantly lower in subjects with daily JA intake than in those with none or only occasional intake (2.13 ± 3.14 vs 2.70 ± 3.82, P = 0.005). In particular, subjects who consumed JA daily showed significantly improved FSSG dysmotility scores compared with subjects who did not (1.05 ± 1.58 vs 1.46 ± 2.11, P0.001). In contrast, the FSSG reflux score did not differ between subjects with and without daily intake of JA (1.08 ± 1.90 vs 1.24 ± 2.11, P = 0.177). Subanalysis indicated that improvement in dysmotility by JA intake was specifically observed in non-elderly (1.24 ± 1.68 vs 1.62 ± 2.22, P = 0.005) and H. pylori-negative subjects (0.99 ± 1.58 vs 1.57 ± 2.06, P0.001). GERD patients (total FSSG score ≥ 8) were less frequently observed among subjects with daily intake of JA as compared to those without daily intake of JA (6.1% vs 9.7%, P = 0.040).Daily JA intake may improve digestive dysmotility symptoms, resulting in relief of GERD symptoms. The effect is more obvious in non-elderly and H. pylori-negative subjects.

A 77-year-old man hospitalized for epigastric pain showed jaundice of the skin and conjunctivae. Laboratory tests revealed elevated hepatobiliary enzymes and inflammatory markers, and imaging studies demonstrated a 12 cm hepatic cyst compressing the common bile duct. The diagnosis was a giant hepatic cyst causing obstructive jaundice. Cyst drainage and sclerotherapy with 5% monoethanolamine oleate was performed twice, resulting in almost complete disappearance of the cyst. Obstructive jaundice due to a hepatic cyst, as seen in this case, is relatively rare and this report includes a review of other similar cases in Japan.

Received January 19, 2005, from the Second Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan (H.T., M.O., H.M., N.S., T.K., S.E., T.S., M.I., K.N., K.A., K.Y., Y.S., H.N., M.I.); and Department of Gastroenterology, University of Tokyo, Tokyo, Japan (M.F., N.Y., S.S.). Revision requested February 7, 2005. Revised manuscript accepted for publication March 1, 2005. Address correspondence to Hideyuki Tamai, MD, Second Department of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama 640-0012, Japan. Abbreviations CT, computed tomography; HCC, hepatocellular carcinoma; PEIT, percutaneous ethanol injection therapy; RFA, radio frequency ablation; S, segment; TAE, transcatheter arterial embolization ntraperitoneal bleeding due to a ruptured tumor is a serious complication in patients with hepatocellular carcinoma (HCC). According to data compiled by the Liver Cancer Study Group of Japan,1 ruptured HCC accounts for around 10% of deaths in these patients. Clinical features include the sudden onset of abdominal pain and distension and, if bleeding is massive, the presence of shock. Other causes of an acute abdominal emergency must be ruled out. Diagnostic imaging generally includes sonography, contrast computed tomography (CT), and angiography. In patients with ruptured HCC, prompt diagnosis and treatment is essential to avoid hepatocyte necrosis and secondary hepatic failure associated with shock and decreased hepatic perfusion due to bleeding. The underlying liver disease varies in such patients with ruptured HCC. Chronic hepatitis, cirrhosis, or both may be present, and the severity of hepatic dysfunction as well as the size, number, and progression of the neoplastic lesions present varies from case to case. A common feature is the presence of a responsible lesion on or protruding from the surface of the liver. If hemostasis can be achieved early after HCC rupture, then overall prognosis depends on the patient’s liver function and degree of tumor progression. Although there is a risk of intraperitoneal seeding, long-term survival is possible if the tumor can be completely resected by hepatectomy. One study has already reported a good 5-year survival rate after resection of ruptured and nonruptured HCC.2 In another study, rather than performing emergency surgery, Marini et al3 used transcatheter arterial embolization (TAE) to control bleeding; in those patients who could then undergo surgery, elective hepatectomy was associated with long-term survival. Treatment of ruptured HCC involves more than just hemostasis. Subsequent therapy is important, and, whenever possible, complete resection should be performed after bleeding has been controlled.

Background and study aims Sodium hyaluronate (SH) is a promising submucosal injection solution during endoscopic mucosal resection, but its high cost is an obstacle to more widespread use. The aim of this study was to identify an appropriate low-cost SH solution by varying the molecular weight of SH and mixing various solutions with it. Materials and methods The viscoelasticity of various SH solutions was first measured. The concentrations of two 1 % SH preparations with different molecular weights (800 kDa and 1900 kDa) were adjusted to 0.5 %, 0.25 %, and 0.125 %, using 0.9 %/3.75 % normal saline (NS), 5 %/20 % dextrose water (DW), and a glycerin solution (Glyceol): 10 % glycerin with 0.9 % normal saline plus 5 % fructose. The ability of these SH solutions to create submucosal fluid cushions (SFCs) was then investigated in the stomachs of two live minipigs. Results The 0.25 % 1900 kDa SH/NS solution and the 0.125 % 1900 kDa SH/20 % DW solution created a similar viscoelasticity to that of the 0.5 % 800 kDa SH/NS solution. The ability of these solutions to create SFCs was also similar. In addition, the 0.125 % 1900 kDa SH/Glyceol solution created similar SFCs, with a synergistic effect of increased viscoelasticity and the hypertonic nature of glycerin. Conclusions A mixture of higher molecular weight sodium hyaluronate with a sugar solution (particularly 20 % dextrose), with or without glycerin, should be regarded as a cost-effective option for creating SFCs instead of the conventional SH solution made with the same amount of a 1 % 800 kDa SH preparation and normal saline.

Background: Although the strip biopsy method and aspiration method are popular endoscopic mucosal resection techniques for its convenience and reliability, they have limitations in resectable tumor size and location. Endoscopic submucosal dissection techniques using the diathermic needle knife or the insulated-tip diathermic knife have been introduced to overcome this disadvantage, but they have high risks for bleeding and perforation. Therefore, we have developed a new endoscopic submucosal dissection technique using the tip of an electrosurgical snare (thin type) and assessed its efficacy. Methods: Fifty-nine lesions with differentiated-type gastric cancer without ulceration were treated with our technique at the University Hospital. The tip of an electrosurgical snare (thin type) was used for mucosal incision and submucosal dissection as a flexible diathermic knife. Results: The size of tumor was 5–85 mm in diameter (mean size: 29 mm) and the location varied from cardia to antrum. Among 59 lesions, 56 lesions (56/59, 95%) were resected completely in an en-bloc fashion with much less perforation (2/59, 3.4%) and bleeding (1/59, 1.7%) regardless of their size and location. Conclusion: New endoscopic submucosal dissection technique using the tip of an electrosurgical snare (thin type) is safe and reliable. We were able to resect early gastric cancer with a much higher en-bloc resection rate and fewer complications using this technique.

Our study investigated the relationship between gastric cancer development and activity of Helicobacter pylori-associated chronic gastritis or the resulting chronic atrophic gastritis (CAG). A cohort of 4,655 healthy asymptomatic subjects, in whom serum pepsinogen (PG) and H. pylori antibody titer had been measured to assess the activity and stage of H. pylori-associated chronic gastritis, was followed for up to 16 years, and cancer development was investigated. In subjects with a serologically diagnosed healthy stomach (H. pylori-negative/CAG-negative), cancer incidence rate was low, at 16/100,000 person-years. With the establishment of H. pylori infection and progression of chronic gastritis, significant stepwise cancer risk elevations were seen from CAG-free subjects (H. pylori-positive/CAG-negative) [hazard ratio (HR) = 8.9, 95% confidence interval (CI) = 2.7-54.7] to subjects with CAG (H. pylori-positive/CAG-positive) (HR = 17.7, 95% CI = 5.4-108.6) and finally to subjects with metaplastic gastritis (H. pylori-negative/CAG-positive) (HR = 69.7, 95% CI = 13.6-502.9). In H. pylori-infected CAG-free subjects, significantly elevated cancer risk was observed in the subgroup with active inflammation-based high PG II level or potent immune response-based high H. pylori antibody titer; the former was associated with a particularly high risk of diffuse-type cancer, and both subgroups showed high cancer incidence rates of around 250/100,000 person-years, comparable to that in subjects with CAG. No such risk elevation was observed in H. pylori-infected subjects with CAG. These results clearly indicate that gastric cancer develops mainly from the gastritis-atrophy-metaplasia-cancer sequence and partly from active inflammation-based direct carcinogenesis, and that serum levels of PG and H. pylori antibody titer provide indices of cancer development in H. pylori-infected subjects.

AIM: To develop a new continuous suction mouthpiece (CSM) and evaluate its usefulness for screening esophagogastroduodenoscopy (EGD). METHODS: A total of 196 patients who were scheduled to undergo screening EGD were assigned to one of two groups: a group using the CSM and a group using a conventional mouthpiece. Extent of salivary flow, frequency of saliva suction, number of choking episodes during the examination, and incidence of aspiration pneumonia after the examination were evaluated and compared between the two groups. Adverse events during and after EGD were also examined. In addition, the oral cavity was meticulously examined after the EGD. RESULTS: The same number of patients was randomly allocated to each group. There were no significant differences between the two groups in sex, age, biopsy procedure, duration of procedure and depth of sedation. Aspiration pneumonia and other significant adverse events were not observed in either group. The grade of extent of salivary flow was significantly lower in patients with the CSM than in patients with the conventional mouthpiece (P < 0.001). Although there was no significant difference, less frequent suctioning and fewer choking episodes were observed in patients with the CSM than in patients with the conventional mouthpiece (P = 0.082 and P = 0.084, respectively). In addition, there were no patients in the CSM group who required saliva suctioning during the procedure. CONCLUSION: Use of the CSM during screening EGD can reduce the extent of salivary flow. The device is expected to reduce complications and contamination with saliva.

Chronic inflammation triggered by Helicobacter pylori causes altered DNA methylation in stomach mucosae, which is deeply involved in gastric carcinogenesis. This study aimed to elucidate the correlation between altered mucosal DNA methylation levels and activity of H. pylori-related gastritis, because inflammatory activity shows particular correlations with the development of diffuse-type cancer.Methylation levels in stomach mucosae of 78 healthy volunteers were determined by real-time methylation-specific PCR or bisulfite pyrosequencing. Examined loci were the promoter CpG islands of six genes (FLNc, HAND1, THBD, p41ARC, HRASLS, and LOX) and the CpG sites of non-coding repetitive elements (Alu and Satα) that are reportedly altered by H. pylori infection. Activity of H. pylori-related gastritis was evaluated using two serum markers: H. pylori antibody titer and pepsinogen II.Methylation levels of the six CpG islands were consistently increased, and those of the two repetitive elements were consistently decreased in a stepwise manner with the activity of gastric inflammation as represented by serum marker levels. Each serum marker level was well correlated with the overall DNA methylation status of stomach mucosa, and these two serologic markers were additive in the detection of the mucosa with severely altered DNA methylation.Alteration in mucosal DNA methylation level was closely correlated with activity of H. pylori-related gastritis as evaluated by serum markers. The observed correlation between altered DNA methylation levels and activity of H. pylori-related gastritis appears to be one of the relevant molecular mechanisms underlying the development of diffuse-type cancer.

Although frequent vomiting reflexes during esophagogastroduodenoscopy (EGD) causes suffering in patients, very few studies have investigated the characteristics of subjects who frequently develop vomiting reflexes. This study examined the incidence of the vomiting reflex and related factors, especially upper gastrointestinal symptoms, among individuals undergoing transoral EGD.Subjects included 488 consecutive adults (mean age, 56.1 ± 8.9 years) who underwent transoral EGD for gastric cancer screening between February 2010 and March 2011. All procedures were performed by an endoscopist with 15 years of experience. Based on a questionnaire survey using the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), symptoms (dyspepsia and acid reflux symptoms) and the number of vomiting reflexes during EGD were recorded.Of the 488 subjects, 271 (56%) developed vomiting reflexes (mean, 4.2 times). This reflex-positive group was younger (54.3 ± 9.5 years) than the reflex-negative group (58.3 ± 7.7 years, P0.001). The number of subjects in the reflex-positive group with a high FSSG dyspepsia score (2.27 ± 2.57 vs 1.23 ± 1.84; P0.001), acid reflux symptom score (1.96 ± 2.22 vs 1.34 ± 2.14; P0.01) or an esophageal hiatal hernia (14.8% vs 4.6%; P0.001) was significantly higher than in the reflex-negative group. Multivariate analysis also showed a significant correlation between these four factors and the occurrence of vomiting reflexes. Using an FSSG dyspepsia score of 1 as the cut-off offered 68% sensitivity and 57% specificity for predicting the occurrence of vomiting reflexes.Based on FSSG questionnaire responses on upper gastrointestinal symptoms, dyspepsia symptoms, in particular, are related to presence of vomiting reflexes during EGD.

In a previous population-based case-control study, we demonstrated an elevated risk of colorectal neoplasia with Helicobacter pylori (H. pylori) infection. The present study investigated the effects of H. pylori-associated chronic gastritis on the development of colorectal neoplasia by analyzing the recurrence of colorectal neoplasia subsequent to endoscopic resection. Ninety-nine patients who had undergone endoscopic resection of colorectal neoplasia were monitored under colonoscopy, and the recurrence of colorectal neoplasia was prospectively investigated. The stage of H. pylori-associated chronic gastritis in each subject was evaluated using a combination of two serum tests: H. pylori antibody and pepsinogen. In the present cohort, colorectal neoplasia recurred at a rate of 15,296/100,000 person-years during the study period. After adjusting for the confounding factors, chronic atrophic gastritis (CAG) was identified as an independent risk factor [adjusted hazard ratio (HR), 2.72; 95% confidence interval, 1.33–5.57], while H. pylori-infected non-atrophic gastritis was not identified as an independent risk factor for recurrent colorectal neoplasia. Colorectal neoplasia recurred earlier and was significantly more frequent in patients with CAG (22,573/100,000 person-years) compared to patients without CAG (11,089/100,000 person-years; P=0.029, log-rank test). Patients with more extensive CAG showed a higher risk of recurrence. These results demonstrated a significant elevation of the risk of recurrent colorectal neoplasia with the establishment and progression of CAG, indicating the involvement of H. pylori infection in the development of colorectal neoplasia. The two serum tests were useful clinical markers for noninvasively evaluating the risk of each individual for recurrent colorectal neoplasia subsequent to endoscopic resection.

Tumor-suppressor genes on chromosome X can be inactivated by a single hit, any of the point mutations, chromosomal loss and aberrant DNA methylation. As aberrant DNA methylation can be induced frequently, we here aimed to identify a tumor-suppressor gene on chromosome X inactivated by promoter DNA methylation. Of 69 genes on chromosome X upregulated by treatment of a gastric cancer cell line with a DNA-demethylating agent, 5-aza-2'-deoxycytidine, 11 genes had low or no expression in the cell line and abundant expression in normal gastric mucosae. Among them, FHL1 was frequently methylation-silenced in gastric and colon cancer cell lines, and methylated in primary gastric (21/80) and colon (5/50) cancers. Knockdown of the endogenous FHL1 in two cell lines by two kinds of shRNAs significantly increased cell growth in vitro and sizes of xenografts in nude mice. Expression of exogenous FHL1 in a non-expressing cell line significantly reduced its migration, invasion and growth. Notably, a somatic mutation (G642T; Lys214Asn) was identified in one of 144 colon cancer specimens, and the mutant FHL1 was shown to lack its inhibitory effects on migration, invasion and growth. FHL1 methylation was associated with Helicobacter pylori infection and accumulated in normal-appearing gastric mucosae of gastric cancer patients. These data showed that FHL1 is a methylation-silenced tumor-suppressor gene on chromosome X in gastrointestinal cancers, and that its silencing contributes to the formation of an epigenetic field for cancerization.

This study aimed to elucidate groups at high risk of developing cancer among patients with serologically identified Helicobacter pylori infection and nonatrophic stomach. Annual endoscopy was performed for a mean of 5.4 years in 496 asymptomatic middle-aged men who were H. pylori antibody-positive and pepsinogen (PG) test-negative. Subjects were stratified according to the activity of H. pylori-associated gastritis measured by serum levels of PG and H. pylori antibody, and/or by endoscopic findings of rugal hyperplastic gastritis (RHG), and cancer development was investigated. During the study period, seven cases of cancer developed in the cohort (incidence rate, 261/100,000 person-years), with 85.7% developing in the group showing a PGI/II ratio ≤ 3.0, reflecting active inflammation-based high PGII levels. Cancer incidence was significantly higher in this group (750/100,000 person-years) than in groups with less active gastritis. Furthermore, cancer incidence for this group was significantly higher in the subgroup with high H. pylori antibody titers than in the low-titer subgroup. Meanwhile, endoscopic findings revealed that 11.7% of subjects showed RHG reflecting localized highly active inflammation, and cancer risk was significantly higher in patients with RHG than in patients without. Combining the two serum tests and endoscopic examination for RHG allowed identification of subjects with more active gastritis and higher cancer risk. No cancer development was observed in these high-risk subjects after H. pylori eradication. Subjects with highly active gastritis identified by the two serological tests and endoscopic RHG constitute a group at high risk of cancer development with H. pylori-infected nonatrophic stomach.

Endoscopic ultrasonography (EUS) was performed on a patient being treated for chronic pancreatitis because a submucosal tumor was observed in the stomach during gastrointestinal endoscopy. As internal pulsatile blood flow on Doppler was present, the diagnosis of an aneurysm was made. The pseudoaneurysm of the left gastric artery was embolized with histoacryl and lipiodol and the splenic artery was embolized with coils at the location of the pseudoaneurysm to prevent hemorrhage. Follow up EUS confirmed the cessation of blood flow from the pseudoaneurysm. Clinicians encountering a gastric submucosal tumor-like protrusion in a patient with chronic pancreatitis should use EUS to investigate the possibility of a pseudoaneurysm, which must be treated as quickly as possible once identified.

Continuation of pegylated interferon (PEG-IFN) plus ribavirin at the recommended dose is difficult in elderly patients and/or patients with cytopenia or complications. Whether the therapeutic efficacy of low-dose PEG-IFN plus ribavirin therapy could be predicted based on virological response within 2 weeks of therapy initiation was evaluated. A total of 106 patients with a high viral load of genotype-1b hepatitis C virus (HCV) underwent low-dose PEG-IFN plus ribavirin therapy. PEG-IFN alpha 2b (0.75 µg/kg per week) and ribavirin (600-800 mg/day) were administered for 48 weeks. Sustained virological response (SVR) was achieved in 37%, and treatment was discontinued in 9%. On univariate analysis of SVR-contributing factors, significant differences were noted in the white blood cell count, platelet count, fibrosis markers, and viral reduction within 2 weeks from therapy initiation. On multivariate analysis, the platelet count and the reduction in the HCV core antigen level at week 2 were independent factors. The positive predictive value (PPV) and the negative predictive value (NPV) for SVR based on a 1-log or greater HCV-RNA level reduction at week 2 were 65% and 90%, respectively, and those based on HCV core antigen level at week 2 were 64% and 97%, respectively. PPV and NPV based on a 2-log or greater reduction of the RNA level were 86% and 67%, respectively, and those based on the core antigen level were 93% and 69%, respectively. Evaluation of viral reduction at week 2 after therapy initiation is useful for predicting SVR to low-dose PEG-IFN plus ribavirin therapy.

Helicobacter pylori (HP) is recognized as a major pathogenic factor for persistent inflammation in the human stomach (Dooley et al., 1989; Marshall & Warren, 1984). In 1994, the International Agency for Research on Cancer (IARC) classified HP infection as a definite class I carcinogen (International Agency for Research on Cancer (IARC), 1994). HP triggers chronic inflammation of the infected stomach mucosa and is considered a major risk factor for gastric cancer (GC) and associated precursor lesions. Long-lasting inflammation in the stomach mucosa leads to a cascade of molecular and morphological changes, representing the gastritis-atrophymetaplasia-dysplasia-cancer sequence (Correa, 1992). The HP infection rate is higher in Japan than in Western countries, with nearly all cases of GC occurring in subjects with underlying HP-related chronic gastritis. HP infection is widely accepted as a major risk factor for the development of GC and its precursor lesions, based on extensive evidence derived from many studies (Blaser et al., 1995; EUROGAST Study Group, 1993; Forman et al., 1991; Hirayama et al., 1999; Honda et al., 1998; Huang et al., 1998; Nomura et al., 1991; Parsonnet et al., 1991; Shimizu et al., 1999; Sipponen et al., 1992; Sugiyama et al., 1998; Talley et al., 1991; Tokieda et al., 1999; Uemura et al., 2001; Watanabe et al., 1998; Zheng et al., 2004). However, in countries such as Japan, where the HP infection rate is high, prediction of GC risk based solely on the presence or absence of HP infection does not offer sufficient specificity. Elucidation of groups at high risk based on the natural history of GC is clearly necessary. The identification of useful markers of GC risk is thus hoped for. Evaluating HPrelated chronic gastritis and determining which subjects are at high risk for developing GC is very important, and would likely increase the efficacy of GC screening by endoscopic or other examinations (Enomoto et al., 2010a; Mukoubayashi et al., 2007; Ohata et al., 2005), and strategic approaches to metachronous multiple GC after endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) performed as minimally invasive treatment for early GC (Gotoda, 2007; Kakushima & Fujishiro, 2008; Nakajima et al., 2006). In addition, in terms of GC prevention, it has become clear that HP-related chronic gastritis cannot be ignored as an origin of carcinogenesis.

To clarify the clinical features of and risk factors for extrahepatic seeding, a major complication following radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). Our prospective database of 351 nodules in 257 patients with HCC who had undergone RFA between April 2001 and April 2008 was reviewed. The following variables were assessed to identify the risk factors for extrahepatic seeding: age, sex, viral markers, Child-Pugh class, tumor size, number of tumors, RFA indication (tumor size ≤3 cm, number of tumors ≤3), tumor biopsy prior to RFA, degree of histological differentiation, tumor markers, tumor location, number of sessions, and combined transcatheter arterial chemoembolization. The median follow-up period was 36.5 months, during which the rate of seeding after was 5.1% and the 5-year cumulative seeding rate was 8.4%. The survival rate after neoplastic seeding was 21% at 5 years. Univariate analysis of the risk factors for neoplastic seeding showed significant differences in tumor size, RFA indication, subcapsular lesion, number of sessions, tumor biopsy prior to RFA, and des-gamma-carboxy prothrombin value. However, multivariate analysis showed that the only independent risk factor was RFA indication. The prognosis of patients with neoplastic seeding was poor. In particular, RFA performed for HCC not satisfying the RFA indication showed a high risk of seeding, and careful consideration should be given to the optimal treatment method and avoiding direct puncture of subcapsular tumors.

Evaluation of malignant potential is important to determine the treatment strategy for small hepatocellular carcinoma (HCC). The aim of the present study was to establish a method of assessing the malignant potential of small hypervascular HCC using B-mode ultrasonography. One hundred and thirteen arterial hypervascular HCC nodules under 3 cm diagnosed by biopsy or surgical resection (20.5 ± 6.3 mm) were classified into two groups ultrasonographically: type 1 with (n = 27) and type 2 without (n = 86) a halo. Type 2 was categorized into three subgroups: type 2a, homogenous hyperechoic (n = 9); type 2b, hypoechoic with a smooth margin (n = 35); and type 2c, hypoechoic with an irregular or unclear margin (n = 42). The mean diameter of type 2a nodules was significantly smaller than that of other HCC types (P 0.05). Overall, moderately differentiated HCC was the predominant histological type, except for type 2a, all of which were well-differentiated HCC. The percentage of poorly differentiated HCC was significantly higher in type 2c nodules (19%) than in other HCC types (P 0.01). The percentage of Lens culinaris agglutinin-reactive α-fetoprotein (AFP-L3) positivity was significantly higher in type 2c nodules (55%) than in other HCC types (P 0.01). Classification on B-mode ultrasonography was correlated with the histological differentiation and serum level, an indicator of a poor prognosis. The malignant potential of type 2a is the lowest and that of type 2c is the highest, both histologically and serologically. Assessment of the malignant potential of small, hypervascular HCC is possible by B-mode ultrasonography.

Although CD57+ lymphocytes are closely correlated with prognosis in various cancers, the role of subsets of CD57+ cells in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) is unclear. In the present study, peripheral blood (PB) from HCV-related HCC patients was analyzed. Plasma cytokine levels and in vitro cytokine-producing capabilities were analyzed with enzyme-linked immunosorbent assays, and CD57+ cell subsets were studied using a multi-color FACS system. Interferon (IFN)-γ was undetectable in the plasma of patients with tumors at any stage, whereas the plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-10 and IL-18, but not that of IL-12, were significantly higher in stage IV patients compared to patients with earlier-stage tumors. In contrast, the IFN-γ-producing capability of PB was highest in stage I patients and gradually decreased with tumor progression. The IL-10-, IL-18- and IL-12-producing capabilities of PB increased from stage I to III. However, PB-TNF-α, IL-10- and IL-18-producing capabilities were reduced in stage IV patients, probably due to repeated anti-cancer treatments. The percentage of CD4+CD57+αβTCR+ cells (CD4+CD57+ T cells) in peripheral blood lymphocytes (PBLs) increased with tumor progression. Moreover, the percentage of CD4+CD57+ T cells in PBLs and the ratio of CD4+CD57+ T cells to CD4+αβTCR+ cells (CD4+ T cells), but not that of CD4+CD57+ T cells to CD57+αβTCR+ cells (CD57+ T cells), showed a significant inverse correlation with PB-IFN-γ-producing capability. The present results suggest that an increase in CD4+CD57+ T cells controls the capability of PB to produce the anti-tumor cytokine IFN-γ and that PB-IFN-γ production is impaired with HCC tumor progression.

AIM: To evaluate the association of Helicobacter pylori (H.pylori)-related chronic gastritis stage with upper gastrointestinal symptoms and gastroesophageal reflux disease (GERD). METHODS: Subjects underwent upper gastrointestinal endoscopy, a questionnaire using a frequency scale for symptoms of GERD (FSSG), and measurements of serum H.pylori-antibody and pepsinogen (PG) levels. They were classified into the following 4 groups in terms of H.pylori-related chronic gastritis stage: Group A (n = 219), H.pylori(-)PG(-); Group B (n = 310), H.pylori(+)PG(-); Group C (n = 279), H.pylori(+)PG(+); and Group D (n = 17), H.pylori(-)PG(+). RESULTS: Reflux esophagitis occurred in 30.6% of Group A, 14.5% of Group B, 6.8% of Group C, and 0% of Group D (P < 0.001). Scores for acid reflux symptoms decreased significantly with chronic gastritis stage (from Group A to D) (P < 0.05), while scores for dysmotility symptoms did not differ significantly. The prevalence of non-erosive reflux disease (NERD) did not differ among groups. However, in subjects with GERD, the prevalence of NERD tended to increase with chronic gastritis stage (P = 0.081). CONCLUSION: Acid reflux symptoms and the prevalence of reflux esophagitis can be assessed by measuring both serum H.pylori-antibody and PG levels.

In recent years, the prevalence of peptic ulcer has been increasing among the elderly. The characteristics of gastric ulcers in elderly patients include an increased rate of complications such as bleeding and perforation and a tendency to increase in severity. In conjunction with increases in the elderly population, current challenges include therapeutic measures against bleeding ulcers. In hemorrhagic stomach ulcers, some cases present with critical complications such as shock, and a prompt response is thus required. After the stabilization of circulatory and respiratory conditions is attained, endoscopic hemostatic procedures should be extended. When performing endoscopy for an elderly patient, existing functional impairments may lead to unforeseeable events, and it is therefore necessary to pay close attention to ensure the safety of such patients.

This study investigated correlations between Helicobacter pylori infection or chronic atrophic gastritis (CAG) and risk of colorectal adenoma in a population-based case-control study. Subjects comprised asymptomatic, middle-aged, male Japanese factory workers who participated in an annual health check-up program, including cancer screening with colonoscopy. We selected 239 colorectal adenoma cases based on histological evaluation and 239 age-matched adenoma-free controls, and evaluated colorectal adenoma risk according to stage of H. pylori-related chronic gastritis as determined by serum tests for H. pylori antibody titer and pepsinogen. Subjects with colorectal adenoma were more likely to be smokers and have hypercholesterolemia. H. pylori infection was a risk factor for adenoma as a whole (crude odds ratio [OR]: 2.26, 95% confidence interval [CI]: 1.44-3.55). Analysis of distal adenoma cases showed that adenoma risk was significantly increased in the presence of H. pylori infection, but there was no further increase in risk with CAG. In contrast, proximal adenoma risk increased stepwise with the presence and progression of H. pylori-related chronic gastritis and showed a maximal and significant increase with CAG (crude OR: 4.51, 95% CI: 1.43-14.2). Subjects with more extensive and severe gastritis showed still higher risk not only for proximal but also for distal adenoma. H. pylori-related chronic gastritis is likely to be involved in the development of colorectal neoplasms, and its progression appears to increase the risk, particularly for proximal adenomas. Knowing the H. pylori-related chronic gastritis stage will probably be useful for evaluation of risk for colorectal neoplasia.

Global hypomethylation and regional hypermethylation are supposed to be hallmarks of cancer cells. During gastric carcinogenesis, in which Helicobacter pylori infection is causally involved, aberrant hypermethylation is already present in H. pylori-infected gastric mucosae. In contrast, little is known about global hypomethylation, which can be caused by hypomethylation of individual repetitive elements and other sequences. We, therefore, investigated hypomethylation of individual repetitive elements and the global 5-methylcytosine content in four groups of gastric mucosal samples that represented the time course of H. pylori infection and gastric carcinogenesis [gastric mucosae of H. pylori-negative healthy volunteers (G1, n = 34), H. pylori-positive healthy volunteers (G2, n = 42), H. pylori-positive gastric cancer patients (G3, n = 34) and H. pylori-negative gastric cancer patients (G4, n = 20)] and 52 primary gastric cancers. Major variants of Alu, LINE1 and Satα were identified, and their methylation levels were quantified by bisulfite pyrosequencing. Compared with G1, the Alu methylation level was decreased in G2, G3, G4 and cancers (89.2-97.1% of that in G1, p < 0.05). The Satα methylation level was decreased in G2 (91.6%, p < 0.05) and G3 (94.3%, p = 0.08) but not in G4 and cancers. The LINE1 methylation level was decreased only in cancers. The 5-methylcytosine content was at similar levels in G2, G3 and G4 and highly variable in cancers. These results showed that Alu and Satα hypomethylation is induced in gastric mucosae by H. pylori infection during gastric carcinogenesis, possibly in different target cells, and that global hypomethylation is not always present in human gastric cancers.

We investigated the correlation between Japanese apricot (JA) intake and Helicobacter pylori-related chronic atrophic gastritis (CAG).A questionnaire was administered and serum anti-H. pylori IgG antibodies measured in 1358 asymptomatic adults. The subjects were divided into high-intake and low-intake groups. Histological and serological evaluation of H. pylori-related CAG was performed in 68 non-elderly volunteers.The H. pylori-negative rate did not differ significantly between the high-intake and low-intake groups. Mean antibody titers were lower in the high-intake group, but the difference was not significant. There was no significant difference in the rate of H. pylori infection on the basis of JA intake when subjects were stratified by age. Among H. pylori-positive non-elderly subjects, antibody titers were significantly lower in the high-intake group (P=0.041). Endoscopic tissue biopsy from the 68 volunteers showed less H. pylori bacterial load and mononuclear infiltration irrespective of gastric site in the high-intake group. In the high-intake group, antral neutrophil infiltration was significantly less pronounced and corporal atrophy was less extensive. Serological evaluation using serum PG levels also confirmed these histopathological data.Our findings strongly indicate a preventive effect of JA intake on CAG by inhibiting H. pylori infection and reducing active mucosal inflammation.

The present study investigated the preventive effects of etodolac, a selective cyclo-oxygenase (COX)-2 inhibitor, on metachronous cancer development after endoscopic resection of early gastric cancer. Among 267 early gastric cancer patients who underwent endoscopic resection, 47 patients with extensive metaplastic gastritis were selected based on endoscopic findings and our previously described criteria of serum pepsinogen (PG) test-positive and Helicobacter pylori antibody-negative conditions. Nonrandomized etodolac treatment (300 mg/day) was administered to 26 patients (Group A), while the remaining 21 patients were untreated (Group B). No significant differences in age, sex distribution, lifestyle factors or extent of metaplastic gastritis at baseline were identified between groups. Patients were followed for metachronous cancer development with endoscopy every 6-12 months for up to 5 years. Mean (standard deviation) follow-up period was 4.2 (0.9) years. In Group B, 5 cancers developed (incidence rate = 6,266/100,000 person-years), significantly more than the 1 cancer in Group A (incidence rate = 898/100,000 person-years; p < 0.05). Long-term etodolac treatment did not influence the extent of metaplastic gastritis as revealed by endoscopic findings or by serum PG levels, but effectively reduced metachronous cancer development in patients with extensive metaplastic gastritis. These results strongly suggest that chemoprevention of cancer in the metaplastic stomach is possible by controlling COX-2 expression.

A longitudinal cohort study was conducted in Helicobactor pylori-infected middle-aged Japanese males to evaluate the preventive effects of H. pylori eradication on the development of gastric cancer according to the extent of chronic atrophic gastritis (CAG). The extent of CAG was monitored by baseline serum pepsinogen (PG) levels. We followed 3,656 subjects with persistent H. pylori infection and 473 subjects with successful H. pylori eradication for cancer development for a mean (SD) of 9.3 (0.7) years. Groups with and without extensive CAG were categorized based on PG test-positive criteria to detect extensive CAG of PG I ≤ 70 ng/ml and PG I/II ratio ≤ 3.0. During the study period, 5 and 55 gastric cancers developed in H. pylori-eradicated and the noneradicated subjects, respectively, indicating no significant reduction in cancer incidence after H. pylori eradication. Among the noneradicated subjects, 1,329 were PG test-positive and 2,327 were PG test-negative. Gastric cancer was confirmed in 30 and 25 subjects, respectively. Among subjects whose infection was eradicated, 155 were PG test-positive and 318 were PG test-negative. Of these subjects, gastric cancer was confirmed in 3 and 2 subjects, respectively. Significant reduction in cancer incidence after eradication was observed only in PG test-negative subjects (p < 0.05; log-rank test). The results of this study strongly indicate that cancer development after eradication depends on the presence of extensive CAG before eradication and that H. pylori eradication is beneficial to most PG test-negative subjects with mild CAG as defined by the aforementioned criteria. © 2009 UICC

Helicobacter pylori (HP) infection potently induces aberrant DNA methylation in gastric mucosae, and its accumulation is associated with gastric cancer risk. Cross-sectional analysis of methylation levels (fraction of methylated DNA molecules) and temporal analysis of methylation incidence suggested that methylation levels decrease after HP infection discontinues. We aimed to demonstrate the decrease in methylation levels. Thirty-five patients with HP infection who had undergone curative endoscopic resection and 11 healthy volunteers were recruited. Methylation levels were quantified by real-time methylation-specific PCR. Histology was evaluated according to the updated Sydney System. In the 20 patients with successful eradication, the FLNc methylation level, along with infiltration of inflammatory cells, decreased from 0.6 to 0.4% at 6 weeks (P = 0.049) and remained low at 1 year. The THBD methylation level (30.1%) remained high at 6 weeks, but decreased to 19.0% at 1 year (P = 0.0032). Nine healthy volunteers with successful eradication tended to show a decrease of both FLNc and THBD at 6 weeks. However, the methylation levels after the decrease were still higher than those of healthy individuals without HP infection. In the 15 patients with persistent infection, the methylation levels remained the same. Before eradication, the THBD methylation level correlated with the degree of inflammatory cell infiltration (P

Accumulation of aberrant DNA methylation in normal-appearing gastric mucosae, mostly induced by H. pylori infection, is now known to be deeply involved in predisposition to gastric cancers (epigenetic field defect), and silencing of protein-coding genes has been analyzed so far. In this study, we aimed to clarify the involvement of microRNA (miRNA) gene silencing in the field defect. First, we selected three miRNA genes as methylation-silenced after analysis of six candidate "methylation-silenced" tumor-suppressor miRNA genes. Methylation levels of the three genes (miR-124a-1, miR-124a-2 and miR-124a-3) were quantified in 56 normal gastric mucosae of healthy volunteers (28 volunteers with H. pylori and 28 without), 45 noncancerous gastric mucosae of gastric cancer patients (29 patients with H. pylori and 16 without), and 28 gastric cancer tissues (13 intestinal and 15 diffuse types). Among the healthy volunteers, individuals with H. pylori had 7.8-13.1-fold higher methylation levels than those without (p < 0.001). Among individuals without H. pylori, noncancerous gastric mucosae of gastric cancer patients had 7.2-15.5-fold higher methylation levels than gastric mucosae of healthy volunteers (p < 0.005). Different from protein-coding genes, individuals with past H. pylori infection retained similar methylation levels to those with current infection. In cancer tissues, methylation levels were highly variable, and no difference was observed between intestinal and diffuse histological types. This strongly indicated that methylation-silencing of miRNA genes, in addition to that of protein-coding genes, contributed to the formation of a field defect for gastric cancers.

A total of 5,209 asymptomatic, middle-aged subjects, whose serum pepsinogen (PG) and Helicobacter pylori antibody levels had been assessed, were followed for 10 years. Subjects with positive serum H. pylori antibodies (50 U/mL) had an increased cancer risk (HR = 3.48, 95% CI = 1.26-9.64). Risk of gastric cancer increased as the antibody level increased; the H. pylori-positive group with antibody levels500 U/mL had the highest incidence rate (325/100,000 person-years). Cancer development also increased with a reduced serum PG I level or a reduced PG I/II ratio; the risk was significantly elevated with serum PG I levelor=30 ng/mL (HR = 3.54, 95% CI = 1.95-6.40) or PG I/II ratioor=3.0 (HR = 4.25, 95% CI = 2.47-7.32). Furthermore, the risk of diffuse-type cancer increased as PG II level increased; it was significantly elevated with PG II levelor=30 ng/mL (HR = 3.81, 95% CI = 1.10-13.21). Using H. pylori antibody and PG levels, subgroups with an especially high or low cancer incidence rate could be identified. H. pylori-negative or indeterminate subjects with low PG level (PG Ior=30 ng/mL or PG I/II ratioor=2.0) or H. pylori-positive subjects with antibody levels500 U/mL and a low PG level were among the subgroups with a high cancer incidence rate (over 400/100,000 person-years). In contrast, H. pylori-negative subjects with a PG I level70 ng/mL or a PG I/II ratio3.0 had the lowest risk; none of these subjects developed cancer. Thus, serum PG levels and/or H. pylori antibody levels can be used to predict the risk of cancer in individuals with H. pylori-related gastritis from the general population.

Aims: To compare twice-daily interferon (IFN)-β administration and once-daily IFN-α-2b administration as induction therapy in ribavirin combination therapy in chronic hepatitis C with a high viral load of genotype-1b hepatitis C virus (HCV). Methods: Sixty-one chronic hepatitis patients with a high viral load of genotype-1b HCV were randomly divided into three groups: group A was given IFN-β 6 MU induction therapy twice daily for 2 weeks; group B was given IFN-α-2b 6 MU induction therapy once daily for 2 weeks; and group C was given no induction therapy. All three groups were then given IFN-α-2b 6 MU 3 days/week for the rest of the 24-week study period. Ribavirin was given for the entire 24-week study period. Results: Although the cumulative HCV-RNA negative rates tended to be higher in group A than in group B, the differencewas not significant. The HCV-RNA negative rate at week 2 was significantly higher in groups A and B than in group C (P

Objective The purpose of this study was to evaluate the usefulness of contrast-enhanced ultrasonography (CEUS) in the diagnosis of solid renal tumors. Methods Twenty-nine patients with solid tumors detected on gray scale ultrasonography underwent resection for suspected renal malignancy. Findings of arterial phase contrast computed tomography (CT) and CEUS were compared for each diagnosis. Results Histopathologic examination of resected lesions showed malignancy in 26 patients (clear cell carcinoma, n = 18; papillary renal cell carcinoma, n = 6; collecting duct carcinoma, n = 1; and infiltrative urothelial carcinoma, n = 1) and benign tumors in 3 patients (oncocytoma, n = 2; and angiomyolipoma, n = 1). Contrast CT failed to show tumor blood flow in 5 of 29 patients, whereas CEUS showed this in all patients. Positive predictive values of CEUS and contrast CT in the diagnosis of renal malignancy were 100% and 82.8%, respectively. Among clear cell carcinomas, hypervascularity was observed on contrast CT in 16 of 18 patients and on CEUS in 17 of 18 patients. On the basis of hypervascularity, diagnostic sensitivity values for clear cell carcinoma were 94.4% for CEUS and 88.9% for contrast CT, whereas specificity values were 45.5% for CEUS and 72.7% for contrast CT. Among papillary cell carcinomas, contrast CT showed avascular lesions in 4 of 6 patients. However, CEUS showed blood flow in these lesions, leading to diagnosis of hypovascular renal tumors. Conclusions Contrast-enhanced ultrasonography was more sensitive for detecting slight tumor blood flow than contrast CT and was useful in preoperatively diagnosing malignant hypovascular renal tumors but was less so for hypervascular renal tumors.