Effect of High Pressure Processing on a Wide Variety of Human Noroviruses Naturally Present in Aqua-Cultured Japanese Oysters.

The contamination of oysters with human norovirus (HuNoV) poses a human health risk, as oysters are often consumed raw. In this study, the effect of high pressure processing (HPP) on a wide variety of HuNoVs naturally present in aqua-cultured Japanese oysters was determined through a polymerase chain reaction-based method with enzymatic pretreatment, to distinguish between infectious HuNoV. Among five batches, genogroup I. genotype 1 (GI.1), GI.2, GI.3, and GI.8 HuNoV were detected from only one oyster not treated with HPP in the fifth batch, while genogroup II. genotype 1 to 4 (GII.1 to 4), GII.6, GII.8., GII.9, GII.13, GII.16, GII.17, and GII.22 HuNoV were detected from oysters not treated with HPP in all tested batches as determined by next-generation sequencing analysis. Neither GI nor GII HuNoV was detected in the oysters of any of the batches after HPP treatment. To our knowledge, this is the first study to investigate the effect of HPP on a wide variety of HuNoVs naturally present in aqua-cultured oysters.

Effect of High-Pressure Processing on Human Noroviruses in Laboratory-Contaminated Oysters by Bio-Accumulation.

The contamination of oysters with human noroviruses poses a human health risk, since oysters are often consumed raw. In this study, human norovirus genogroup II was allowed to bio-accumulate in oysters, and then the effect of high-pressure processing (HPP) on human noroviruses in oysters was determined through a polymerase chain reaction (PCR)-based method with enzymatic pretreatment to distinguish infectious noroviruses. As a result, oysters could be artificially contaminated to a detectable level of norovirus genome by the reverse transcription-PCR. Concentrations of norovirus genome in laboratory-contaminated oysters were log normally distributed, as determined by the real-time PCR, suggesting that artificial contamination by bio-accumulation was successful. In two independent HPP trials, a 1.87 log10 and 1.99 log10 reduction of norovirus GII.17 genome concentration was observed after HPP at 400 MPa for 5 min at 25°C. These data suggest that HPP is a promising process of inactivation of infectious human noroviruses in oysters. To our knowledge, this is the first report to investigate the effect of HPP on laboratory-contaminated noroviruses in oysters.

Next-Generation Sequencing Analysis of the Diversity of Human Noroviruses in Japanese Oysters.

To obtain detailed information on the diversity of infectious norovirus in oysters (Crossostrea gigas), oysters obtained from fish producers at six different sites (sites A, B, C, D, E, and F) in Japan were analyzed once a month during the period spanning October 2015-February 2016. To avoid false-positive polymerase chain reaction (PCR) results derived from noninfectious virus particles, samples were pretreated with RNase before reverse transcription-PCR (RT-PCR). RT-PCR products were subjected to next-generation sequencing to identify norovirus genotypes in oysters. As a result, all GI genotypes were detected in the investigational period. The detection rate and proportion of norovirus GI genotypes differed depending on the sampling site and month. GII.3, GII.4, GII.13, GII.16, and GII.17 were detected in this study. Both the detection rate and proportion of norovirus GII genotypes differed depending on the sampling site and month. In total, the detection rate and proportion of GII.3 were highest from October to December among all detected genotypes. In January, the detection rates of GII.4 and GII.17 reached the same level as that of GII.3. The proportion of GII.17 was relatively lower from October to December, whereas it was the highest in January. To our knowledge, this is the first investigation on noroviruses in oysters in Japan, based on a method that can distinguish their infectivity.

Application of Next-Generation Sequencing to Evaluate the Profile of Noroviruses in Pre- and Post-Depurated Oysters.

The development of procedures for the efficient removal or inactivation of noroviruses from contaminated oysters is of great interest in oyster production. However, there is a critical limitation for evaluating the depuration efficacy of presently available procedures, as no suitable cell culture system currently exists to cultivate noroviruses. Thus, we applied a next-generation sequencing (NGS) technique to characterize norovirus genotypes in pre- and post-depurated oysters. As a result, we revealed the diversity of noroviruses in pre- and post-depurated oysters. Although the applied depuration procedure could reduce the number of bacterial agents to the level recommended by the Japanese Ministry of Health, Labour and Welfare, no significant changes were observed in the detection rate and the proportion of norovirus group (G) I and GII genotypes. To our knowledge, this is the first report to evaluate the profile of noroviruses in pre- and post-depurated oysters, specifically with respect to norovirus removal, using NGS; the findings imply that the removal of noroviruses from oysters through depuration is not presently sufficient. Further studies are needed to develop a more suitable depuration procedure for removing and/or inactivating noroviruses from contaminated oysters.

Application of next-generation sequencing to investigation of norovirus diversity in shellfish collected from two coastal sites in Japan from 2013 to 2014.

A better understanding of the role played by shellfish regarding the manner of pathogen contamination, persistence, and selection may help considering epidemiology of noroviruses. Thus, norovirus genotype profiles in shellfish (Crassostrea gigas and Mitilus galloprovincialis) were investigated by using Next-generation sequencing (NGS) technology. In genogroup I (GI), 7 genotypes (abbreviated as GI.2 to GI.7, and GI.9) were detected from C. gigas, whereas 9 genotypes (GI.1 to GI.9) were detected from M. galloprovincialis. The genotype with the highest proportion found in both C. gigas and M. galloprovincialis was GI.4, and the second highest was GI.3. In genogroup II (GII), 17 genotypes (GII.1 to GII.9, GII.11 to GII.17, GII.21 and GI.22) were detected from C. gigas, whereas 16 genotypes (GII.1 to GII.8, GII.11 to GII.17, GII.21 and GI.22) were detected from M. galloprovincialis. The genotype with the highest proportion in both C. gigas and M. galloprovincialis was GII.4, the next highest differed between C. gigas and M. galloprovincialis. To our knowledge, this study may be the first trial to utilize the latest technology in this field, and reveal the diversity of norovirus genotypes present in shellfish.

Protective effect of lactoferrin on acute acid reflux-induced esophageal mucosal damage.

BACKGROUND/AIMS: The natural immunomodulator lactoferrin is known to possess anti-inflammatory effects. However, there have been no studies examining the mode of action of lactoferrin in protecting the esophageal mucosa against damage. We investigated the effect of lactoferrin on gastric acid secretion and in protecting against acute acid reflux-induced esophagitis in rats. METHODOLOGY: Male Wistar rats aged 8 weeks, weighing 210-240 g, were used for all the experiments. A gastric perfusion system was installed using the method of Ghosh et al. Lactoferrin was administered once via the caudate vein, starting 24 hours before an acute acid reflux (treatment mode), or saline (control). Statistical comparison of the parameters between the two test conditions was performed. RESULTS: No significant differences in basal or stimulated gastric acid secretion, or in the serum gastrin level were observed between the two test conditions. Esophageal damage was attenuated by lactoferrin in a dose-dependent manner, as reflected by the improvement in the esophageal tissue weight and macroscopic scores. Significant reductions in the histological scores, myeloperoxidase activity and the levels of proinflammatory cytokines, tumor necrosis factor-α and interleukin-1ß were also observed following lactoferrin administration. CONCLUSIONS: We concluded that lactoferrin exerts a protective effect against acute acid reflux-induced esophageal damage in rats.

Correlation between gastric transit time measured by video capsule endoscopy and gastric emptying determined by the continuous real-time 13C breath test (BreathID system).

BACKGROUND/AIMS: The aim of this study was to determine the possible existence of a correlation between the gastric transit time (GTT) measured by video capsule endoscopy (VCE) and the parameters of gastric emptying determined using 13C breath test (BreathID system). METHODS: Eight healthy male volunteers participated in this randomized, two-way crossover study. The subjects were randomly assigned to undergo VCE using the PillCam SB capsule endoscopy system or the 13C breath test for 4 hours after a test meal (400 kcal per 400 mL) containing 100 mg of 13C acetic acid administered after overnight fasting. The VCE images were analyzed and the GTT was determined using the proprietary RAPID software. The parameters, namely T lag, T 1/2 and GEC were calculated using the Oridion Research Software (ß version). The GTT measured by VCE and the parameters of gastric emptying were compared statistically. RESULTS: No significant correlation was observed between the GTT and T lag (p = 0.5263), T 1/2 (p = 0.4100) or GEC (p = 0.2410), as determined by calculation of the Spearman's rank correlation coefficient. CONCLUSIONS: GTT measured by VCE cannot serve as asubstitute for the gastric emptying time measured bythe 13C breath test.

Umbilical cord blood-derived mesenchymal stem cells inhibit, but adipose tissue-derived mesenchymal stem cells promote, glioblastoma multiforme proliferation.

Mesenchymal stem cells (MSCs) possess self-renewal and multipotential differentiation abilities, and they are thought to be one of the most reliable stem cell sources for a variety of cell therapies. Recently, cell therapy using MSCs has been studied as a novel therapeutic approach for cancers that show refractory progress and poor prognosis. MSCs from different tissues have different properties. However, the effect of different MSC properties on their application in anticancer therapies has not been thoroughly investigated. In this study, to characterize the anticancer therapeutic application of MSCs from different sources, we established two different kinds of human MSCs: umbilical cord blood-derived MSCs (UCB-MSCs) and adipose-tissue-derived MSCs (AT-MSCs). We used these MSCs in a coculture assay with primary glioblastoma multiforme (GBM) cells to analyze how MSCs from different sources can inhibit GBM growth. We found that UCB-MSCs inhibited GBM growth and caused apoptosis, but AT-MSCs promoted GBM growth. Terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end labeling assay clearly demonstrated that UCB-MSCs promoted apoptosis of GBM via tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TRAIL was expressed more highly by UCB-MSCs than by AT-MSCs. Higher mRNA expression levels of angiogenic factors (vascular endothelial growth factor, angiopoietin 1, platelet-derived growth factor, and insulin-like growth factor) and stromal-derived factor-1 (SDF-1/CXCL12) were observed in AT-MSCs, and highly vascularized tumors were developed when AT-MSCs and GBM were cotransplanted. Importantly, CXCL12 inhibited TRAIL activation of the apoptotic pathway in GBM, suggesting that AT-MSCs may support GBM development in vivo by at least two distinct mechanisms-promoting angiogenesis and inhibiting apoptosis. The opposite effects of AT-MSCs and UCB-MSCs on GBM clearly demonstrate that differences must be considered when choosing a stem cell source for safety in clinical application.

Risk factors for mortality in patients with Mallory-Weiss syndrome.

BACKGROUND/AIMS: Although the majority of patients with Mallory-Weiss syndrome (MWS) have a benign course, in some patients MWS results in a fatal outcome. Therefore, this study was carried out to analyze the risk factors for mortality in patients with MWS. METHODOLOGY: The medical records of patients with MWS seen between March 1994 and July 2007 were reviewed retrospectively. The demographic characteristics, clinical and laboratory parameters, and endoscopic findings of the patients were analyzed and the risk factors for mortality were evaluated. RESULTS: A total of ninety-three patients (13 female and 80 male patients; median age, 53 years) were treated. The mortality rate was 9.7% (9/93). The patients with a fatal outcome were of advanced age and had a higher frequency of shock on arrival, lower hemoglobin level, more prolonged prothrombin time, higher AST and ALT levels, higher frequency of detection of exposed vessels on endoscopy, higher frequency of rebleeding, longer hospital stay, and required a larger volume of blood transfusion than those who did not have a fatal outcome. According to the results of a multivariate analysis, the significant risk factors for mortality in the MWS patients were advanced age (OR 1.222, 95% CI 1.015-1.028), very low hemoglobin level (OR 2.137, 95% CI 1.063-4.295), elevated AST level (OR 1.007, 95% CI 1.001-1.013), and presence of the clinical symptom of tarry stool (OR 45.45, 95% CI 1.080-1000). CONCLUSIONS: Intensive care with close monitoring is required for patients of advanced age with a low hemoglobin level, an elevated AST level, and the clinical symptom of tarry stool, since these are of prognostic importance in terms of the mortality in MWS patients.

Solitary Peutz-Jeghers type hamartomatous polyps in the duodenum are not always associated with a low risk of cancer: two case reports.

INTRODUCTION: A hamartomatous polyp without associated mucocutaneous pigmentation or a family history of Peutz-Jeghers Syndrome is diagnosed as a solitary Peutz-Jeghers type hamartomatous polyp. As compared with Peutz-Jeghers Syndrome, Peutz-Jeghers type hamartomatous polyps are diagnosed with a lower risk of cancer and are regarded as a different disorder. CASE PRESENTATION: In case one, we describe an 84-year-old Japanese man with a 14 mm duodenal polyp. Endoscopic mucosal resection was performed and histological examination showed findings suggestive of a hamartomatous polyp with a focus of well-differentiated adenocarcinoma. In case two, we describe a 76-year-old Japanese man who had been treated for prostate, rectal and lung cancer. Upper gastrointestinal endoscopy revealed a duodenal polyp measuring 15 mm in diameter. Endoscopic mucosal resection was performed, and histological examination showed findings suggestive of a hamartomatous polyp. Liver and thyroid cancers were found after the endoscopic treatment. CONCLUSION: Although duodenal solitary hamartomatous polyps are associated with a lower risk of cancer, four patients, including our cases, have been diagnosed with cancerous polyps. Patients with duodenal solitary hamartomatous polyps should be treated by endoscopic or surgical resection and need whole-body screening.

Incidence of and risk factors for upper gastrointestinal complications in patients taking low-dose aspirin in Japan.

BACKGROUND/AIMS: Low-dose aspirin is widely used for the prevention of cardiovascular and cerebrovascular diseases. However, administration of low-dose aspirin is associated with an increased risk of upper gastrointestinal complications, such as upper gastrointestinal erosions, ulcers and bleeding. The aim of this study was to clarify the prevalence and various clinical factors of upper gastrointestinal complications associated with low-dose aspirin treatment. METHODOLOGY: A total of 1213 patients taking low-dose aspirin were evaluated with upper endoscopic examinations. We studied retrospectively the incidence of and risk factors for upper gastrointestinal complications associated with low-dose aspirin use. RESULTS: Of the 1213 patients taking low-dose aspirin, 598 patients and 72 patients were found to have gastroduodenal erosions (57.3%) and peptic ulcers (5.9%), respectively. Of these 72 peptic ulcers, 27 were diagnosed as hemorrhagic ulcers. Previous ulcer history was identified as a risk factor for peptic ulcer and upper gastrointestinal bleeding during low-dose aspirin therapy. Upper gastrointestinal symptoms and no use of gastroprotective agents were also identified as risk factors for peptic ulcers. In this study, the use of a histamine-2 receptor antagonist was indicated as a protective factor for peptic ulcers. CONCLUSIONS: Low-dose aspirin therapy is associated with an increased risk of developing upper gastrointestinal complications. Administration of a histamine-2 receptor antagonist was effective for the prevention of low-dose aspirin induced peptic ulcers.

Factors associated with motivation and hesitation to work among health professionals during a public crisis: a cross sectional study of hospital workers in Japan during the pandemic (H1N1) 2009.

BACKGROUND: The professionalism of hospital workers in Japan was challenged by the pandemic (H1N1) 2009. To maintain hospital function under critical situations such as a pandemic, it is important to understand the factors that increase and decrease the willingness to work. Previous hospital-based studies have examined this question using hypothetical events, but so far it has not been examined in an actual pandemic. Here, we surveyed the factors that influenced the motivation and hesitation of hospital workers to work in Japan soon after the pandemic (H1N1) 2009. METHODS: Self-administered anonymous questionnaires about demographic character and stress factors were distributed to all 3635 employees at three core hospitals in Kobe city, Japan and were collected from June to July, 2009, about one month after the pandemic (H1N1) in Japan. RESULTS: Of a total of 3635 questionnaires distributed, 1693 (46.7%) valid questionnaires were received. 28.4% (N = 481) of workers had strong motivation and 14.7% (N = 249) had strong hesitation to work. Demographic characters and stress-related questions were categorised into four types according to the odds ratios (OR) of motivation and hesitation to work: some factors increased motivation and lowered hesitation; others increased motivation only; others increased hesitation only and others increased both motivation and hesitation. The strong feeling of being supported by the national and local governments (Multivariate OR: motivation; 3.5; CI 2.2-5.4, hesitation; 0.2; CI 0.1-0.6) and being protected by hospital (Multivariate OR: motivation; 2.8; CI 2.2-3.7, hesitation; 0.5; CI 0.3-0.7) were related to higher motivation and lower hesitation. Here, protection included taking precautions to prevent illness among workers and their families, providing for the care of those who do become ill, reducing malpractice threats, and financial support for families of workers who die on duty. But 94.1% of the respondents answered protection by the national and local government was weak and 79.7% answered protection by the hospital was weak. CONCLUSIONS: Some factors have conflicting effects because they increase both motivation and hesitation. Giving workers the feeling that they are being protected by the national and local government and hospital is especially valuable because it increases their motivation and lowers their hesitation to work.

Prevention of mothers' mental illness deterioration: can their attitudes toward self-care and childcare prevent mental deterioration?

BACKGROUND: Women with severe mental illness experience many kinds of problems during childcare and have a high risk of relapse. Previous studies have not revealed methods for preventing deterioration of mothers' illness. In this study, we retrospectively investigated mothers with severe mental illness, and we attempted to identify characteristics of mothers whose condition did not deteriorate and who did not require hospitalization during childcare. METHODS: Data were collected from a self-administered questionnaire filled out by female outpatients who had experienced childcare and were diagnosed with schizophrenia, schizoaffective disorder, bipolar affective disorder or depression with psychotic symptoms. The questionnaire asked about attitudes toward childcare during the first three years following the first childbirth. It was composed of six sections on A) living situation, B) psychiatric medication, C) sleep, D) subjective symptoms of deterioration, E) resting time, and F) advice for other mothers with mental illness. The subjects were split into two groups: those that were admitted to a hospital within three years following the first childbirth (hospital group, n=16) and those that were not hospitalized (non-hospital group, n=19). RESULTS: The two groups showed no significant differences in their responses to the questions in sections A-E of the questionnaire. In section F, the non-hospital group wrote significantly more comments than the hospital group. The non-hospital group described concrete ways for taking care of their mental health, while the hospital group did not. DISCUSSION: Our results suggest that whether or not mothers need admission during childcare depends on their assertiveness and ability to communicate.

Gastric surgery is not a risk factor for erosive esophagitis or Barrett's esophagus.

OBJECTIVE: The role of gastric acid reflux is difficult to separate from that of pancreatic-biliary reflux in the pathogenesis of erosive esophagitis (EE) and Barrett's esophagus (BE). Gastric surgery patients provide a good model for both significant pancreatic-biliary reflux and marked gastric acid inhibition. We assessed the risk of EE and BE after distal gastrectomy in a case-controlled study. MATERIAL AND METHODS: One hundred and sixty patients (121 men, 39 women; median age 68 years; range 32-86 years) with distal gastrectomies (Billroth-I) and 160 sex- and age-matched controls with intact stomachs were enrolled. The presence of EE and BE were diagnosed based on the Los Angeles Classification and the Prague C & M Criteria, respectively. A conditional logistic regression model with adjustments for potential confounding factors was used to assess the associations. RESULTS: According to the multivariate analyses, patients with distal gastrectomies tended to have inverse associations with the risks of EE and BE, and the inverse association with the risk of BE reached a significant level. CONCLUSIONS: Distal gastrectomy is not a risk factor for the development of EE and BE. This lack of a positive association between distal gastrectomy and EE and BE may suggest that pancreatic-biliary reflux with a limited amount of acid is not sufficient to damage the esophageal mucosa.

Management of acute lower intestinal bleeding: what bowel preparation should be required for urgent colonoscopy?

BACKGROUND/AIMS: The management of acute intestinal bleeding is not standardized. The aim of this study was to determine the most suitable method of bowel preparation for urgent colonoscopy. METHODOLOGY: One hundred and forty patients admitted with acute lower intestinal bleeding (ALIB) to our Hospital (April 1998 to March 2004) were studied. The preparation for colonoscopy consisted, usually, of oral administration of polyethylene glycol (PEG)-salt solution. For elderly patients or for those suspected of bleeding from a sigmoid colon lesion, colonoscopy was performed following glycerin enemas or water enemas. For patients with a suspected rectal lesion or soon after undergoing a polypectomy, colonoscopy was performed without any of the above procedures. RESULTS: Ischemic colitis was the most common cause of bleeding. The overall cecal completion ratio was 41%, compared with 74% in the PEG group. The percentage of those in whom colonoscopy was impossible (poor preparation) was 16% overall, compared with 5% in the PEG group. Endoscopic hematemesis were performed successfully for 26 patients who were mainly postpolypectomy cases or had rectal ulcers. CONCLUSIONS: In urgent colonoscopy, the preparation with PEG-salt solution may improve the patient's outcome. In postpolypectomy patients and those with rectal ulcers preparation was not always needed.

National monitoring for antimicrobial resistance among indicator bacteria isolated from food-producing animals in Japan.

The antimicrobial susceptibilities of 2,205 isolates of Escherichia coli and 1,181 isolates of Enterococcus faecalis (n=610) and E. faecium (n=571) from apparently healthy cattle, pigs and broiler and layer chickens collected from 2000 to 2003 were examined using an agar dilution method. Overall, the isolates from cattle and layer chickens showed a lower incidence of resistance to almost all antimicrobials studied compared with those from pigs and broiler chickens. Fluoroquinolone resistance was found at a low level in isolates of E. coli from four animal species and in E. faecalis from pigs and broiler and layer chickens. Resistance to cephalosporin was identified in isolates of E. coli from broiler chickens in 2000-2002 and from four animal species in 2003. Incidence of antimicrobial resistance in the bacteria did not vary from year to year during the investigation period.

Does postprandial coffee intake enhance gastric emptying?: a crossover study using continuous real time 13C breath test (BreathID system).

BACKGROUND/AIMS: Coffee is one of the most popular beverages worldwide, however, few studies have examined the effects of coffee on the gastrointestinal system. The aim of this study was to determine whether there was a correlation between coffee intake and gastric emptying using a novel non-invasive technique for measuring gastric emptying with a continuous real time 13C breath test (BreathID system: Oridion, Israel). METHODOLOGY: Six healthy male volunteers participated in this randomized, two-way crossover study. The subjects were randomly assigned to receive a test meal (200 kcal per 200 mL) plus postprandial 190 mL black coffee or the test meal alone after fasting overnight. A 13C-acetic acid breath test was continuously performed using the BreathID system, which monitors gastric emptying, for 4 hours after the administration of the test meal. Using Oridion Research Software (beta version), the time for emptying of 50% of the labeled meals (T 1/2) and the analog to the scintigraphy lag time for 10% emptying of the labeled meal (T lag) were calculated. The parameters between two occasions were compared using the Wilcoxon signed-rank test. RESULTS: After coffee intake the T 1/2 and T lag constant were significantly decreased. CONCLUSIONS: The decrease in the T 1/2 and T lag suggests the acceleration of gastric emptying. This study showed that postprandial coffee intake enhances gastric emptying, suggesting the potential use of coffee in clinical settings for patients with functional gastrointestinal disorders.

Early effects of intravenous administrations of lansoprazole and famotidine on intragastric pH.

BACKGROUND/AIMS: The ideal medication for treatment of acid related diseases should have a rapid onset of action to promote hemostasis. The aim of our study was to investigate the inhibitory effects on gastric acid secretion after single intravenous administrations of lansoprazole 30 mg and famotidine 20 mg. METHODOLOGY: Twelve Helicobacter pylori-negative male subjects participated in this randomized, two-way crossover study. Intragastric pH was monitored continuously for 4 hours after single intravenous administration of lansoprazole 30 mg or famotidine 20 mg. RESULTS: The average pH during the 4-hour period after administration of famotidine was higher than after lansoprazole (median: 5.15 versus 3.55, respectively; p = 0.0376). During the 4-hour study period, famotidine 20 mg provided a longer duration of pH > 3, 3.5, 4, 5, 6 and 7, compared to lansoprazole 30 mg (median: 73.6% versus 57.0%; p = 0.0414, 66.8% versus 47.8%; p = 0.0281, 60.8% versus 38.8%; p = 0.0150, 55.7% versus 29.7%; p = 0.0281, 45.0% versus 23.1%; p = 0.0414 and 23.9% versus 3.65%; p = 0.0076). CONCLUSIONS: In Helicobacter pylori-negative healthy male subjects, an intravenous dose of famotidine 20 mg more rapidly increases intragastric pH than lansoprazole 30 mg.