Associations between gastric histopathology and the occurrence of colonic polyps

AIM

Compromise of the gastric acid barrier may facilitate bacterial invasion of the lower intestinal tract and promote the development of colonic neoplasia. Our study aimed to test the associations between histopathological abnormalities of the upper and lower gastrointestinal tract in patients undergoing bidirectional endoscopy.

METHOD

The Inform Diagnostics database is a national electronic repository of histopathological records of patients distributed throughout the USA. A case-control study of 302 061 patients, 163 168 of whom had colonic polyps, evaluated whether the occurrence of colonic polyps was influenced by the presence of the following gastro-oesophageal diagnoses: gastric Helicobacter pylori infection, gastric intestinal metaplasia, fundic gland polyps and gastric hyperplastic polyps. The influence of individual diagnoses on the occurrence of colonic polyps was expressed as odds ratios with their 95% confidence intervals.

RESULTS

The odds ratio for tubular adenomas being associated with gastric H. pylori was 1.53 (1.49-1.58), with intestinal metaplasia 1.65 (1.59-1.71), with fundic gland polyps 1.49 (1.45-1.54) and with gastric hyperplastic polyps 1.85 (1.75-1.96). The odds ratio for sessile serrated polyps being associated with gastric H. pylori was 1.03 (0.96-1.10), with intestinal metaplasia 1.21 (1.13-1.30), with fundic gland polyps 1.79 (1.69-1.89) and with gastric hyperplastic polyps 1.52 (1.35-1.71.

CONCLUSION

A diminished gastric acid barrier function, which occurs in various upper gastrointestinal diseases associated with lowered gastric acid output, may promote the development of colonic neoplasia.

Decreased risk for microscopic colitis and inflammatory bowel disease among patients with reflux disease

AIM

Previous studies have found an increased risk for microscopic colitis (MC) associated with proton pump inhibitors. In patients with ulcerative colitis (UC) or Crohn's disease (CD), proton pump inhibitors have been associated with an increased risk for IBD flares and impaired outcomes. The aim of this study was to test the epidemiological associations between gastro-oesophageal reflux disease (GERD) and MC, UC or CD in a large database.

METHOD

The Miraca Life Sciences Database is a national electronic repository of histopathological records of patients distributed throughout the entire USA. A case-control study evaluated whether the presence of Barrett's metaplasia, erosive oesophagitis on endoscopy or histological signs of reflux oesophagitis, clinical diagnosis of GERD or any GERD type affected the occurrence of MC, UC or CD among 228 506 subjects undergoing bidirectional endoscopy. Multivariate logistic regression analyses were used to calculate ORs and their 95% CI for the risk of MC, UC or CD associated with various types of GERD and were adjusted for age, sex and presence of Helicobacter pylori.

RESULTS

The analysis revealed an inverse relationship between GERD and different types of inflammatory bowel disease. The inverse relationships applied similarly to MC (mean = 0.62, 95% CI: 0.58-0.66), UC (mean = 0.89, 95% CI: 0.81-0.97) and CD (mean = 0.76, 95% CI: 0.69-0.85). It also applied to different forms of GERD, with a trend towards more pronounced inverse relationships associated with Barrett's metaplasia or erosive oesophagitis than clinical diagnosis of GERD.

CONCLUSION

Gastro-oesophageal reflux disease is inversely associated with all forms of inflammatory bowel disease, such as MC, UC, or CD.

Quantification of the duodenal eosinophil content in adults: a necessary step for an evidence-based diagnosis of duodenal eosinophilia

BACKGROUND

The normal content of eosinophils in the adult duodenum remains undefined. Therefore, there is no foundation for evidence-based criteria to diagnose eosinophilic duodenitis.

AIM

This study aimed at: (1) establishing the range of the eosinophil density in the mucosa of the duodenum of normal adults, and (2) determining the biopsy-based prevalence of isolated eosinophilic duodenitis in a large population of adults.

METHODS

We counted intact eosinophils in three separate high-power fields (hpf area = 0.237 mm² each) with the highest densities of eosinophils from the duodenal biopsy specimens of 370 consecutive adults (60% women) with no history of small intestinal disease and a normal duodenal histology. From a large database we also extracted patients with a diagnosis of elevated duodenal eosinophilia and reviewed their biopsies and clinical history.

RESULTS

The mean eosinophil count for the 370 patients was 8.2 eos/hpf with a standard deviation of ± 6.3. Twenty-seven of the 370 had eosinophil counts outside the 95% range, which was calculated as: mean + 1.96 × SD = 20.4 eos/hpf. In a database of 458 668 adult subjects, 31 patients (6.8/100 000) had elevated duodenal eosinophilia; 21 of these had other gastrointestinal organs involved by eosinophilia, suggesting eosinophilic gastroenteritis. No significant association between duodenal eosinophilia and any specific symptom was observed.

CONCLUSIONS

This study suggests that in this diverse US population, a cut-off count of 20 eos/hpf would be useful to separate patients with normal from those with elevated duodenal eosinophilic infiltrations. The clinical implications of duodenal eosinophilia, particularly when it is not an expression of eosinophilic gastroenteritis, remain to be established.

The ethnic distribution of sessile serrated polyps in the United States is inversely associated with Helicobacter pylori prevalence

AIM

Little is known about the epidemiology of sessile serrated polyps (SSP). Our study aimed to investigate the influence of Helicobacter pylori gastritis and patient demographic characteristics (age, gender, ethnicity) on the prevalence of SSP using a large national database of patients undergoing bi-directional endoscopy.

METHOD

De-identified patient data were extracted from the Miraca Life Sciences electronic database of histopathological reports. Using multivariate logistic regression analysis, the influence of H. pylori gastritis and demographic characteristics on the occurrence of SSP were expressed as odds ratios (OR) with their 95% confidence intervals (CI).

RESULTS

The total study population comprised 228 506 subjects, of whom 28 890 carried a diagnosis of H. pylori gastritis and 11 285 SSP. Age (OR 4.35, 95% CI: 3.82-4.96), female gender (0.92, 0.88-0.95) and H. pylori gastritis (0.94, 0.88-0.99) exerted the strongest influence on the occurrence of SSP. In comparison with the population comprising Caucasians and African Americans, SSP were less common among subjects of Hispanic (0.67, 0.62-0.73), East Asian (0.59, 0.50-0.69), Indian (0.43, 0.27-0.64) or Middle Eastern descent (0.61, 0.41-0.87). All these ethnic subgroups were also characterized by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of SSP (R²  = 0.82, P < 0.001).

CONCLUSION

The prevalence of SSP within the United States is characterized by a marked ethnic variation. The inverse correlation between the prevalence of H. pylori and SSP suggests that gastric infection with H. pylori may be partly responsible for the observed ethnic distribution of SSP.

Demographic and socioeconomic influences on Helicobacter pylori gastritis and its pre-neoplastic lesions amongst US residents

BACKGROUND

Gastric infection with Helicobacter pylori (Hp) can lead to chronic inactive gastritis, atrophy and intestinal metaplasia.

AIMS

To investigate in a cross-sectional study these changes among different socioeconomic and ethnic groups within the USA.

METHODS

We used the Miraca Life Sciences database, an electronic depository of clinicopathological records from patients distributed throughout the USA, to extract data from 487 587 patients who underwent oesophago-gastro-duodenoscopy with biopsy between 1/2008 and 12/2014. We then classified patients into ethnic and socioeconomic categories using previously validated algorithms, as well as ZIP code-based information derived from the 2011-2012 US Census.

RESULTS

The prevalence of Hp increased significantly until the age-group 40-49, before it leveled off and started a gradual decrease. The prevalence of chronic inactive gastritis, atrophy, and intestinal metaplasia increased significantly with age. The prevalence of Hp, chronic inactive gastritis, intestinal metaplasia, and atrophy decreased significantly with the percentage of Whites per ZIP code. The prevalence of all four diagnoses also decreased significantly with rising levels of income or college education. Hp, chronic inactive gastritis, atrophy and intestinal metaplasia were more common among Hispanics and the influence of income or college education less pronounced than in the entire population. Hp, chronic inactive gastritis, atrophy, and intestinal metaplasia were also more common among East-Asians, Hp and atrophy decreasing with rising income but remaining unaffected by levels of college education.

CONCLUSION

Ethnicity and socioeconomic factors influence the occurrence of Hp gastritis, and its progression to chronic inactive gastritis, atrophy or intestinal metaplasia.

The influence of Helicobacter pylori on the ethnic distribution of Barrett's metaplasia

BACKGROUND

Environmental risk factors associated with ethnicity may contribute to the occurrence of Barrett's metaplasia.

AIM

To investigate the interaction between ethnicity and Helicobacter pylori infection in the occurrence of Barrett's metaplasia among patients undergoing oesophago-gastro-duodenoscopy.

METHODS

The Miraca Life Sciences Database is an electronic repository of histopathological patient records. A case-control study evaluated the influence of age, gender, ethnicity and histological diagnosis of H. pylori on the occurrence of Barrett's metaplasia.

RESULTS

The total study population comprised 596 479 subjects, of whom 76 475 harboured a diagnosis of Barrett's metaplasia. Male sex, age and H. pylori infection in declining order exerted the strongest influence on the occurrence of BM. In comparison with the population comprising Caucasians and African Americans, Barrett's metaplasia was less common among subjects of African (OR = 0.09, 95% CI = 0.01-0.43), Middle Eastern (0.26, 0.20-0.34), East Asian (0.35, 0.31-0.40), Indian (0.39, 0.32-0.47), Hispanic (0.62, 0.59-0.64) or Jewish descent (0.50, 0.45-0.54), but more common among subjects of Northern European descent (1.14, 1.03-1.26). With the exception of Jews and Northern Europeans, all other ethnic subgroups were characterised by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of Barrett's metaplasia (R² = 0.82, P < 0.001), as well as dysplasia or oesophageal adenocarcinoma (R² = 0.81, P < 0.001).

CONCLUSION

Our analysis reveals an inverse relationship between the prevalence of Barrett's metaplasia and H. pylori gastritis among different ethnic groups within the United States.

Differences in the socio-economic distribution of inflammatory bowel disease and microscopic colitis

AIM

Inflammatory bowel disease (IBD) and microscopic colitis are characterized by different geographical distributions across the USA. In this cross-sectional study we utilized demographic and socio-economic information associated with individual ZIP codes to further delineate the epidemiological characteristics of the two diseases.

METHOD

A total of 813 057 patients who underwent colonoscopy between 2008 and 2014 were extracted from an electronic database of histopathology reports. The prevalence of patients with IBD or microscopic colitis was expressed as percentage of the population associated with specific demographic (age, sex, ethnicity) and socio-economic characteristics (population size, housing value, annual income, tertiary education).

RESULTS

Both diseases were more common among subjects from ZIP codes with predominantly White residents and less common among subjects from ZIP codes with predominantly non-White residents such as Black, Hispanic and Asian. These ethnic variations were more pronounced in microscopic colitis than IBD. Markers of affluence, such as average residential house value and annual income, were positively associated with IBD and negatively with microscopic colitis. The prevalence of both diseases was positively correlated with tertiary education.

CONCLUSION

The occurrence of both IBD and microscopic colitis is influenced by environmental risk factors. The differences in the demographic, ethnic and socio-economic distributions of the two diseases suggest that different sets of risk factors affect the two diseases and that their aetiology is unrelated.

Oesophageal signet ring cell carcinoma as complication of gastro-oesophageal reflux disease

BACKGROUND

Signet ring cell carcinoma occurs as a histological variant of oesophageal adenocarcinoma.

AIM

In a cross-sectional study, to pursue the hypothesis that oesophageal signet ring cell cancers constitute a complication of gastro-oesophageal reflux disease.

METHODS

In a large national database of histopathology records, we accumulated 91 802 patients with Barrett's oesophagus (BE), 2817 with oesophageal nonsignet ring adenocarcinoma (EAC) and 278 with oesophageal signet ring cell carcinoma (SRC). The three groups were compared with respect to their clinical and demographic characteristics, as well as socio-economic risk factors (associated with patients' place of residence).

RESULTS

About 9% of all oesophageal adenocarcinomas harboured features of signet ring cell carcinoma. Patients with oesophageal adenocarcinoma and signet ring cell carcinoma were characterised by almost identical epidemiological patterns. Patients with either cancer type were slightly older than those with Barrett's oesophagus (EAC 68.0, SRC 66.7 vs. BE 63.7 years), and both showed a striking male predominance (EAC and SRC 85% vs. BE 67%). Both cancer types were associated with a similar set of alarm symptoms, such as dysphagia, pain and weight loss. The distribution by race (Whites vs. Blacks) and socio-economic parameters, such as levels of college education and family income, were similar among the three groups of patients.

CONCLUSIONS

Signet ring cell carcinoma is a rare variant of oesophageal adenocarcinoma with similar epidemiological characteristics. The reasons why a minority of reflux patients progress to develop signet ring cell carcinoma, rather than the usual type of oesophageal adenocarcinoma, remain unknown.

The stomach in health and disease

The stomach is traditionally regarded as a hollow muscular sac that initiates the second phase of digestion. Yet this simple view ignores the fact that it is the most sophisticated endocrine organ with unique physiology, biochemistry, immunology and microbiology. All ingested materials, including our nutrition, have to negotiate this organ first, and as such, the stomach is arguably the most important segment within the GI tract. The unique biological function of gastric acid secretion not only initiates the digestive process but also acts as a first line of defence against food-borne microbes. Normal gastric physiology and morphology may be disrupted by Helicobacter pylori infection, the most common chronic bacterial infection in the world and the aetiological agent for most peptic ulcers and gastric cancer. In this state-of-the-art review, the most relevant new aspects of the stomach in health and disease are addressed. Topics include gastric physiology and the role of gastric dysmotility in dyspepsia and gastroparesis; the stomach in appetite control and obesity; there is an update on the immunology of the stomach and the emerging field of the gastric microbiome. H. pylori-induced gastritis and its associated diseases including peptic ulcers and gastric cancer are addressed together with advances in diagnosis. The conclusions provide a future approach to gastric diseases underpinned by the concept that a healthy stomach is the gateway to a healthy and balanced host. This philosophy should reinforce any public health efforts designed to eradicate major gastric diseases, including stomach cancer.

Helicobacter-negative gastritis: a distinct entity unrelated to Helicobacter pylori infection

BACKGROUND

Helicobacter-negative gastritis is diagnosed when no organisms are detected in a gastric mucosa with typical features of Helicobacter gastritis (Hp-gastritis). If Helicobacter-negative gastritis consisted mostly of 'missed' Helicobacter infections, its prevalence should represent a constant percentage of these infections in a population, and their clinico-epidemiological features would overlap.

AIM

To compare the epidemiologic patterns of Hp-positive and Hp-negative gastritis.

METHODS

From a pathology database, we extracted demographic, clinical and histopathological data from patients with gastric biopsies (1.2008-12.2013). We allocated patients to high (≥12%) and low (≤6%) H. pylori prevalence regions defined by ZIP code-based data. The prevalence of H. pylori-positive and -negative gastritis by sex, age and state were expressed as a per cent of the total study population stratified accordingly.

RESULTS

Of 895 323 patients, 10.6% had Hp-gastritis and 1.5% Helicobacter-negative gastritis. Hp-gastritis, but not Helicobacter-negative gastritis, was more common in males than females (OR 1.17, 95% CI: 1.16-1.19). While Hp-gastritis was more prevalent in high than in low-prevalence areas (OR 3.65, 95% CI: 3.57-3.74), Helicobacter-negative gastritis was only minimally affected by the underlying H. pylori prevalence (1.7% vs. 1.5%). The age-specific prevalence of Hp-gastritis peaked in the 4th to 5th decades; Helicobacter-negative gastritis exhibited a low and relatively flat pattern. The geographic distribution of H. pylori-positive and -negative gastritis showed no significant correlation. Intestinal metaplasia was found in 13.0% of patients with Hp-gastritis and in 6.1% of those with Helicobacter-negative gastritis (OR 0.43, 95% CI: 0.40-0.47).

CONCLUSION

These data suggest that Helicobacter-negative gastritis is, in the vast majority of cases, a nosologically and epidemiologically distinct entity that deserves further investigation.

Dual roles of hemidesmosomal proteins in the pancreatic epithelium: the phosphoinositide 3-kinase decides

Given the failure of chemo- and biotherapies to fight advanced pancreatic cancer, one major challenge is to identify critical events that initiate invasion. One priming step in epithelia carcinogenesis is the disruption of epithelial cell anchorage to the basement membrane which can be provided by hemidesmosomes (HDs). However, the existence of HDs in pancreatic ductal epithelium and their role in carcinogenesis remain unexplored. HDs have been explored in normal and cancer pancreatic cells, and patient samples. Unique cancer cell models where HD assembly can be pharmacologically manipulated by somatostatin/sst2 signaling have been then used to investigate the role and molecular mechanisms of dynamic HD during pancreatic carcinogenesis. We surprisingly report the presence of mature type-1 HDs comprising the integrin α6β4 and bullous pemphigoid antigen BP180 in the human pancreatic ductal epithelium. Importantly, HDs are shown to disassemble during pancreatic carcinogenesis. HD breakdown requires phosphoinositide 3-kinase (PI3K)-dependent induction of the matrix-metalloprotease MMP-9, which cleaves BP180. Consequently, integrin α6β4 delocalizes to the cell-leading edges where it paradoxically promotes cell migration and invasion through S100A4 activation. As S100A4 in turn stimulates MMP-9 expression, a vicious cycle maintains BP180 cleavage. Inactivation of this PI3K-MMP-9-S100A4 signaling loop conversely blocks BP180 cleavage, induces HD reassembly and inhibits cell invasion. We conclude that mature type-1 HDs are critical anchoring structures for the pancreatic ductal epithelium whose disruption, upon PI3K activation during carcinogenesis, provokes pancreatic cancer cell migration and invasion.

Signaling events mediated by α3β1 integrin are essential for mammary tumorigenesis

The constitutive activation of β-catenin signaling in the mammary basal epithelial cell layer in transgenic K5ΔNβcat mice leads to basal-type tumor development. Integrins of the β1 family and integrin-mediated signaling events have an important role in breast tumor growth and progression. We show here that the deletion of α3β1 integrin, a major laminin receptor, from the basal layer of the mammary epithelium of K5ΔNβcat mice completely prevented the tumorigenesis induced by β-catenin signaling. Moreover, the depletion of α3β1 integrin from a spontaneously transformed mouse mammary basal epithelial cell line (MEC) prevented the cells from forming colonies in soft agar and greatly reduced tumor development in orthotopic grafts. Inhibition of the integrin signaling intermediates Rac1 or PAK1 (P21-activated Kinase 1) in MEC affected tumor cell growth in soft agar, whereas the expression of activated forms of these effectors in α3-depleted cells rescued the capacity of these cells to grow in non-adherent conditions. Similarly, the tumorigenic potential of α3-depleted cells was restored by the expression of activated PAK1, as assessed by orthotopic transplantation assay. In three-dimensional Matrigel culture, MEC survival and proliferation were affected by the depletion of α3β1 integrin, which also significantly decreased the activation of focal adhesion kinase (FAK), mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK). Our data suggest that the activation of signaling cascades downstream from α3β1 and involving the Rac1/PAK1 pathway, MAPK and JNK, promotes prosurvival and proproliferative signals required for the malignant growth of basal mammary epithelial cells, providing further insight into the molecular mechanisms underlying breast cancer initiation and progression.

Review article: historic changes of Helicobacter pylori-associated diseases

BACKGROUND

The long-term time trends of multiple gastrointestinal diseases are characterised by a striking rise and fall. These temporal changes provide important clues about disease aetiology.

AIM

To highlight the importance of Helicobacter pylori infection in shaping the temporal trends of many common gastrointestinal diseases.

METHODS

Literature review of the time trends associated with common digestive diseases.

RESULTS

The general trends of gastric ulcer, duodenal ulcer, gastric cancer, colon cancer, rectum cancer have all been shaped by a similar underlying birth-cohort phenomenon. Mortality associated with these diagnoses increased in all generations born during the nineteenth century. It peaked among generations born shortly before the turn of the century and then decreased in all subsequent generations born throughout the twentieth century. These patterns can be observed in the incidence, hospitalisation and mortality data from many different countries. They reflect similar rising and falling trends of H. pylori infection in the general population. Diseases that are inversely associated with H. pylori, such as reflux disease, erosive oesophagitis, Barrett's oesophagus, and oesophageal adenocarcinoma, have seen a striking rise during the recent decline of H. pylori infection.

CONCLUSION

The temporal variations of H. pylori infection have affected the occurrence of gastroenterology's most common disorders.

Reactive gastropathy is associated with inflammatory conditions throughout the gastrointestinal tract

BACKGROUND

The epidemiology of reactive gastropathy and its relationship with other conditions of the gastrointestinal tract associated with NSAID use have not been evaluated.

AIMS

To test the hypothesis that if reactive gastropathy shares common aetiological factors with these conditions, the analysis of a large cohort would unveil associations.

METHODS

We queried a national pathology database for subjects with a diagnosis of reactive gastropathy; controls were patients with normal gastric biopsies. We also extracted diagnoses of H. pylori infection, intestinal metaplasia, duodenal lymphocytosis, duodenitis, ileitis, microscopic colitis and focal colitis.

RESULTS

Of 504 011 patients with gastric biopsies, 69 101 had oesophageal, 166 134 duodenal, 13 010 ileal and 83 334 colonic biopsies. Reactive gastropathy was diagnosed in 15.6% of patients, H. pylori infection in 10.3% and normal gastric mucosa in 16.3%. Reactive gastropathy was evenly distributed across the US and increased from 2.0% in the first decade of life to >20% in octogenarians. Compared with controls, reactive gastropathy was significantly associated with Barrett's mucosa (OR 1.21 95% CI 1.16-129); duodenitis (OR 1.36; 95% CI 1.28-1.44); duodenal intraepithelial lymphocytosis (OR 1.25; 95% CI 1.13-1.39); active ileitis (OR 1.88; 95% CI 1.47-2.40); focal active colitis (OR 1.57; 95% CI 1.33-1.86); and collagenous colitis (OR 1.50; 95% CI 1.12-2.03).

CONCLUSIONS

Reactive gastropathy, a common histopathological feature of the stomach, shows an age-dependent rise and is associated with changes of the digestive tract believed to be caused by NSAID use or duodenogastric reflux. However, a large fraction of reactive gastropathy remains unexplained; its frequent occurrence merits further efforts at elucidating its aetiology.

Non-Helicobacter pylori gastritis is common among paediatric patients with inflammatory bowel disease

BACKGROUND

Helicobacter-negative gastritis and duodenitis occur more often in patients with inflammatory bowel disease (IBD) than in non-IBD controls. Preliminary evidence suggests that they are particularly common among children.

AIM

To study the age-specific occurrence of gastritis and duodenitis among paediatric IBD patients.

METHODS

From a computerised database of surgical pathology reports, we selected 344 IBD patients and 4241 non-IBD controls between the age 0 and 21 years, who underwent colonoscopy and oesophago-gastro-duodenoscopy with biopsy results from both procedures.

RESULTS

Helicobacter-negative chronic active gastritis was found in 2% of controls and 20% of IBD patients (Crohn's disease (CD) 26%, ulcerative colitis (UC) 13%). Duodenitis was found in 2% of controls and 17% of IBD patients (Crohn's disease 28%, UC 8%). Similar prevalence rates were observed in male and female patients. The most striking age-specific patterns were seen in Crohn's disease, with chronic active gastritis being highest in the 5-9 years age-group and declining in all subsequent age-groups. The age-specific rise and fall of duodenitis appeared more protracted, reaching a peak at age 10-14 years and then gradually declining.

CONCLUSIONS

Helicobacter-negative gastritis and duodenitis occur significantly more often in paediatric IBD patients than in non-IBD controls, as well as in adult IBD patients. Such upper gastrointestinal inflammation appears to be particularly common in patients with Crohn's disease.

[DNA marking of some quantitative trait loci in the cultivated edible mushroom Pleurotus ostratus (Fr.) Kumm]

Fungi of the genus Pleurotus, in particular, species Pleurotus ostreatus (common oyster mushroom) are among most cultivated fungi in the world. Due to intense rates of development of studies in this field, efficient breeding programs are highly required in the search for new P. ostreatus strains. The principal traits used worldwide for selecting strains are intensity of fruitbearing, fruit body cap color (for some consumptive markets), and mycelium growth rate. In this connection, the objective of this work was to study these quantitative traits and to find molecular markers, which could be employed to accomplish breeding programs. In general, we found 12 genomic loci (quantitative trait loci, QTLs) controlling mycelium growth rate of oyster and six QTLs responsible for the fruit body cap color. The genetic map of P. ostreatus was constructed, and all markers of quantitative traits found by us were located on this genetic map. The obtained linkage map can be a useful tool for the accomplishment of breeding programs to improve economically important traits of oyster mushroom.

Low prevalence of Helicobacter pylori infection among patients with inflammatory bowel disease

BACKGROUND

There is some preliminary evidence to suggest that patients with inflammatory bowel disease (IBD) are less frequently infected with Helicobacter pylori than the general population.

AIM

To examine whether the prevalence of Helicobacter pylori (H. pylori) is lower among IBD patients compared with non-IBD individuals based on results from surgical pathology.

METHODS

From a database of surgical pathology reports, we recruited a sample of unique patients who underwent a same-day bidirectional gastrointestinal endoscopy with biopsies. Of the total 65,515 patients, 1061 served as cases with IBD and 64,451 as controls without IBD. The histological presence of H. pylori was correlated with the patients' demographic characteristics and histological presence of any oesophageal disease, Crohn's disease (CD), ulcerative colitis (UC) and indeterminate colitis (IND). Results were expressed as odds ratios (OR), using multivariate logistic regression to adjust for the cofounding influence of comorbidities and demographic characteristics.

RESULTS

The presence of H. pylori was inversely associated with IBD, the adjusted OR and their 95% confidence intervals being 0.48 (0.27-0.79) for CD, 0.59 (0.39-0.84) for UC and 0.43 (0.15-0.95) for IND. In contradistinction, H. pylori-negative gastritis was positively associated with IBD, the adjusted OR being 11.06 (7.98-15.02) for CD, 2.25 (1.31-3.60) for UC and 6.91 (3.50-12.30) for IND.

CONCLUSIONS

Our study confirms an inverse association between H. pylori and IBD and a positive association between the H. pylori-negative gastritis and IBD. These relationships may open new avenues to study the pathogenesis of IBD.

Test sequence in the management of gastrointestinal bleeding

BACKGROUND AND STUDY AIM

A large variety of test procedures is available to diagnose and treat patients with suspected gastrointestinal bleeding. The aim of the study was to investigate which test sequence should be utilized in managing gastrointestinal bleeding.

METHODS

For each endoscopic, radiologic, or laboratory test procedure, professional fees and facility costs were estimated based on payments allowed by the US Centers for Medicare and Medicaid Services during the fiscal year 2010. A threshold analysis was used to compare the costs associated with different test sequences of varying clinical scenarios.

RESULTS

A threshold represents the lowest expected probability of success, for which a test would still be indicated. In a work-up including all possible management options, the threshold associated with laboratory tests and gastric lavage was 1 %, esophagogastroduodenoscopy (EGD) 8 %, colonoscopy 9 %, nuclear scan 9 %, enteroscopy 11 %, computed tomography (CT) angiography 14 %, capsule endoscopy 23 %, and angiography with transcatheter embolization 25 %. Varying sets of thresholds were calculated for different clinical scenarios. The thresholds of EGD and colonoscopy remained low in most scenarios. In sensitivity analysis, rising risk of complications or costs of a procedure also lead to rising threshold values for it, potentially rendering the particular procedure untenable.

CONCLUSIONS

A low threshold indicated a preferred management option that should be used early rather than late in a sequence of multiple possible test procedures to work up instances of gastrointestinal bleeding.

Epidemiology and practice patterns of achalasia in a large multi-centre database

BACKGROUND

Due to its rarity, achalasia remains a difficult disease to study.

AIMS

To describe the epidemiology of achalasia and practice patterns in its endoscopic management, utilising patient records from a large national database of endoscopic procedures.

METHODS

The Clinical Outcomes Research Initiative maintains a database of endoscopic procedures in diverse clinical practices. The data from 89 endoscopy practices distributed throughout the US during 2000-2008 were used to analyse the characteristics and therapy of patients with achalasia.

RESULTS

Among 521,497 upper endoscopies during the study period, we identified 896 patients with achalasia. Compared with the entirety of all other endoscopic diagnoses, achalasia was more common in men than in women (OR=1.39, CI 1.22-1.59), but similar among nonwhites and whites (OR=0.87, CI 0.74-1.03). Relatively, more achalasia patients were treated at university than at community practices (OR=1.52, CI 1.30-1.78). Botox injection was most frequently used as first choice of endoscopic therapy in 41%, followed by balloon dilation in 21%, Savary dilation in 20%, Maloney dilation in 10%, Rigiflex in 4% and other modalities in 4% of patients. One quarter of achalasia patients treated endoscopically underwent a repeat therapy about every 14 months.

CONCLUSIONS

Botox has become the primary choice of initial endoscopic therapy in achalasia. Despite their partial deviation from guidelines and recommendations, these endoscopic patterns reflect the current clinical practice in the United States.