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.

Chitosan nanoparticles-loaded Citrus aurantium essential oil: a novel delivery system for preserving the postharvest quality of Agaricus bisporus

BACKGROUND

One of the main problems in the button mushroom industry is the rapid deterioration of fruit bodies after harvest. Today, nanotechnology has become a more reliable technique to improve the quality of products in food packaging. In the present study, the effectiveness of chitosan nanoparticles containing Citrus aurantium essential oil on postharvest quality of white button mushroom was examined and compared to essential oil fumigation and control treatments.

RESULTS

Based on high-resolution transmission electron microscopy and dynamic light scattering, nanoparticles exhibited a spherical shape of 20-60 nm diameter. The results revealed that the application of chitosan nanoparticles loaded with C. aurantium oil significantly decelerated the rate of color change, weight loss and firmness compared to fumigation with essential oil and control treatments. Treatment of fruit bodies with chitosan nanoparticles loaded with C. aurantium oil promoted the accumulation of phenolic compounds and ascorbic acid, and resulted in increases in catalase and superoxide dismutase and a decrease in polyphenol oxidase activities, as the highest antioxidant capacity was observed after 15 days of cold storage.

CONCLUSION

This present research demonstrates that gradual release of C. aurantium essential oil from chitosan nanoparticles could be an effective and practical method for extending the shelf life of white button mushroom up to 15 days without significant decrease in antioxidant capacity. © 2018 Society of Chemical Industry.

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.

A genetic linkage map of Pleurotus tuoliensis integrated with physical mapping of the de novo sequenced genome and the mating type loci

Background

Pleurotus tuoliensis (Bailinggu) is a commercially cultivated mushroom species with an increasing popularity in China and other Asian countries. Commercial profits are now low, mainly due to a low yield, long cultivation period and sensitivity to diseases. Breeding efforts are thus required to improve agronomical important traits. Developing saturated genetic linkage and physical maps is a start for applying genetic and molecular approaches to accelerate the precise breeding programs.

Results

Here we present a genetic linkage map for P. tuoliensis constructed by using 115 haploid monokaryons derived from a hybrid strain H6. One thousand one hundred and eighty-two SNP markers developed by 2b–RAD (type IIB restriction-site associated DNA) approach were mapped to 12 linkage groups. The map covers 1073 cM with an average marker spacing of 1.0 cM. The genome of P. tuoliensis was de novo sequenced as 40.8 Mb and consisted of 500 scaffolds (>500 bp), which showed a high level of colinearity to the genome of P. eryngii var. eryngii. A total of 97.4% SNP markers (1151) were physically localized on 78 scaffolds, and the physical length of these anchored scaffolds were 33.9 Mb representing 83.1% of the whole genome. Mating type loci A and B were mapped on separate linkage groups and identified physically on the assembled genomes. Five putative pheromone receptors and two putative pheromone precursors were identified for the mating type B locus.

Conclusions

This study reported a first genetic linkage map integrated with physical mapping of the de novo sequenced genome and the mating type loci of an important cultivated mushroom in China, P. tuoliensis. The de novo sequenced and annotated genome, assembled using a 2b–RAD generated linkage map, provides a basis for marker-assisted breeding of this economic important mushroom species.

Electronic supplementary material

The online version of this article (10.1186/s12864-017-4421-z) contains supplementary material, which is available to authorized users.

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.

When to stop the search for an elusive source of gastrointestinal bleeding

BACKGROUND AND STUDY AIMS

This analysis investigates the clinical parameters that should drive decisions about when to continue or stop the search for an elusive source of gastrointestinal bleeding.

PATIENTS AND METHODS

The number of endoscopies necessary to find a source of bleeding was estimated using the geometric distribution. A threshold analysis was used to develop a stop rule for the search for a site of bleeding. Bayes' formula served to estimate changes in the probability of achieving a diagnosis associated with a series of consecutive endoscopic tests.

RESULTS

With decreasing probability of diagnostic success associated with an individual endoscopic procedure, such as P = 50%, 33%, or 25%, the mean (standard deviation [SD]) number of procedures needed to find the source of bleeding increases to 2 (1.41), 3 (2.45), or 4 (3.46), respectively. The threshold analysis suggests that work-up should be discontinued if the expected rise in diagnostic probability does not exceed the ratio of work-up cost to bleeding cost, that is, Δ P < work-up cost/bleeding cost. For instance, a 10-fold higher cost of bleeding than endoscopy would justify continued work-up if it can improve diagnostic probability by 10%. Bayesian analysis shows that after three negative tests the diagnostic probability drops below such a threshold.

CONCLUSIONS

The analysis suggests the following basic rules. The search for a site of gastrointestinal bleeding will take on average 2 procedures with a range of 1 - 4. The search should be continued as long as the diagnostic probability is expected to rise by more than 10 %, which is unlikely after three consecutive negative tests.

Rising trends of gastric cancer and peptic ulcer in the 19th century

BACKGROUND

The risk of dying from gastric cancer appears to have increased among consecutive generations born during the 19th century.

AIM

To follow the time trends of hospitalization for gastric cancer and test whether they confirm such increase.

METHODS

Inpatient records of the last two centuries from four hospitals in Scotland and three US hospitals were analysed. Proportional rates of hospitalization for gastric cancer, gastric ulcer and duodenal ulcer were calculated during consecutive 5-year periods.

RESULTS

The data from all seven cities revealed strikingly similar patterns. No hospital admissions for gastric cancer or peptic ulcer were recorded prior to 1800. Hospital admissions for gastric cancer increased in an exponential fashion throughout the 19th and the beginning of the 20th century. In a majority of cities, the rise in hospitalization for gastric cancer preceded a similar rise in hospitalization for gastric ulcer. Hospitalization for these two latter diagnoses clearly preceded hospitalization for duodenal ulcer by 20-40 years.

CONCLUSIONS

The occurrence of gastric cancer, gastric ulcer and duodenal ulcer markedly increased during the 19th century. Improvements in hygiene may have resulted in the decline of infections by other gastrointestinal organisms that had previously kept concomitant infection by Helicobacter pylori suppressed.

Mitochondrial Haplotype Influences Mycelial Growth of Agaricus bisporus Heterokaryons

We evaluated the influence of mitochondrial haplotype on growth of the common button mushroom Agaricus bisporus. Ten pairs of heterokaryon strains, each pair having the same nuclear genome but different mitochondrial genomes, were produced by controlled crosses among a group of homokaryons of both wild and commercial origins. Seven genetically distinct mitochondrial DNA (mtDNA) haplotypes were evaluated in different nuclear backgrounds. The growth of heterokaryon pairs differing only in their mtDNA haplotypes was compared by measuring mycelial radial growth rate on solid complete yeast medium (CYM) and compost extract medium and by measuring mycelial dry weight accumulation in liquid CYM. All A. bisporus strains were incubated at temperatures similar to those utilized in commercial production facilities (18, 22, and 26(deg)C). Statistically significant differences were detected in 8 of the 10 heterokaryon pairs evaluated for one or two of the three growth parameters measured. Some heterokaryon pairs showed differences in a single growth parameter at all three temperatures of incubation, suggesting a temperature-independent difference. Others showed differences at only a single temperature, suggesting a temperature-dependent difference. The influence of some mtDNA haplotypes on growth was dependent on the nuclear genetic background. Our results show that mtDNA haplotype can influence growth of A. bisporus heterokaryons in some nuclear backgrounds. These observations demonstrate the importance of including a number of mitochondrial genotypes and evaluating different nuclear-mitochondrial combinations of A. bisporus in strain improvement programs.

The influence of environmental risk factors in hospitalization for gastro-oesophageal reflux disease-related diagnoses in the United States

BACKGROUND

The impact of gastro-oesophageal reflux disease on hospitalization is unknown.

AIM

To describe the characteristics of patients hospitalized for diagnoses related to gastro-oesophageal reflux disease (GERD) and find potential environmental influences that affect their hospitalization.

METHODS

Data from the Healthcare Cost and Utilization Project were used to study the demographic characteristics of hospitalizations associated with GERD during 2003-2006. Data from the Centers for Disease Control were used for information about the US prevalence of obesity.

RESULTS

During 2003-2006, 0.5 million patients with a primary and 14.5 million patients with a secondary GERD-related diagnosis became hospitalized in the US. Oesophageal reflux and hiatal hernia were more common in female than in male inpatients, whereas Barrett's oesophagus and oesophageal adenocarcinoma were more common in male than in female inpatients. All GERD-related diagnoses were more common in white people than non-white people. Hospitalizations associated with oesophageal reflux, reflux oesophagitis and Barrett's oesophagus showed resembling geographical distributions among different US states. The prevalence of obesity and the hospitalization for hiatal hernia or reflux oesophagitis were also characterized by similar geographical distributions.

CONCLUSION

The large numbers of inpatients with a discharge diagnosis of GERD-related conditions attest to the frequent occurrence and relevance of GERD in contributing to hospitalization in the US.

Extracellular matrix formation after transplantation of human embryonic stem cell-derived cardiomyocytes

Transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) for cardiac regeneration is hampered by the formation of fibrotic tissue around the grafts, preventing electrophysiological coupling. Investigating this process, we found that: (1) beating hESC-CM in vitro are embedded in collagens, laminin and fibronectin, which they bind via appropriate integrins; (2) after transplantation into the mouse heart, hESC-CM continue to secrete collagen IV, XVIII and fibronectin; (3) integrin expression on hESC-CM largely matches the matrix type they encounter or secrete in vivo; (4) co-transplantation of hESC-derived endothelial cells and/or cardiac progenitors with hESC-CM results in the formation of functional capillaries; and (5) transplanted hESC-CM survive and mature in vivo for at least 24 weeks. These results form the basis of future developments aiming to reduce the adverse fibrotic reaction that currently complicates cell-based therapies for cardiac disease, and to provide an additional clue towards successful engraftment of cardiomyocytes by co-transplanting endothelial cells.

Antiplectin autoantibodies in subepidermal blistering diseases

BACKGROUND

Hemidesmosomal proteins may become targets of autoimmunity in subepidermal blistering diseases. Well-known recognized autoantigens are the intracellular plaque protein BP230, the transmembrane BP180 and its shed ectodomain LAD-1.

OBJECTIVES

To establish the prevalence of autoimmunity against plectin, another intracellular plaque protein, and to investigate its antigenic sites.

METHODS

Two hundred and eighty-two patients with subepidermal blistering diseases, investigated by routine immunoblot analysis for possible antiplectin antibodies, were included in the study. Epitope mapping was performed using recombinantly produced overlapping plectin domains from the actin-binding domain to the rod domain. The COOH-terminal region of plectin was not included in the study.

RESULTS

In 11 of 282 (3.9%) patients an immunoblot staining pattern identical to that of antiplectin monoclonal antibody HD121 was found. Affinity-purified antibodies bound back to normal human skin in a pattern typical for plectin, i.e. to the epidermal basement membrane zone as well as to keratinocytes in the epidermis, and to myocytes. No binding was seen to plectin-deficient skin of a patient with epidermolysis bullosa simplex with muscular dystrophy. Epitope mapping of the plectin molecule showed that the central coiled-coil rod domain is an immunodominant hotspot as 92% of the sera with antiplectin antibodies reacted with it. Most patients with antiplectin antibodies also had antibodies to other pemphigoid antigens.

CONCLUSIONS

Plectin is a minor pemphigoid antigen with an immunodominant epitope located on the central rod domain.

History of dyspepsia in Scotland. Admissions to the Edinburgh Royal Infirmary 1729-1830, doctoral theses 1726-1823, and contemporary British publications

INTRODUCTION

The aim of the study was to assess whether the rise in the occurrence of dyspepsia in Scotland during the eighteenth century was a true epidemiologic phenomenon or just an increase in medical awareness.

METHODS

Admissions for dyspepsia to the Edinburgh Royal Infirmary from 1729 until 1830 were analysed by consecutive five-year time periods. The titles of MD theses on dyspepsia from 1726 to 1823 were extracted from the Edinburgh University index. Monographs and articles on dyspepsia from Britain during the same time period were sought in the Catalogues of the US Surgeon-General's Library.

RESULTS

During the eighteenth century, the annual number of dyspepsia patients admitted to the Edinburgh Royal Infirmary showed an extraordinary increase from none in 1730 to 900 per million population in 1760. About 4000 MD theses were presented to the Edinburgh University between 1726 and 1823. There were none on dyspepsia or gastritis between 1726 and 1749, after when it gradually started to rise. British publications on dyspepsia similarly appeared only in the 1790s and then rapidly increased.

DISCUSSION

We suggest that the rise in MD theses and publications on dyspepsia were responses to a real increase in dyspepsia during the mid eighteenth century.

The lessons learned from randomized clinical trials of GERD

Despite the huge number of randomized controlled clinical trials published on gastro-oesophageal reflux disease, the translation of the information gathered into clinical practice is rather limited. The aim of this article is to summarize the results of pivotal randomized controlled clinical trials and review articles on reflux disease and evaluate to what extent their results can be applied to current clinical practice. We reviewed the most relevant randomized controlled clinical trials and reviews since the publication of the first randomized controlled clinical trial on reflux oesophagitis (1978) to date. Six areas were explored, namely: (1) diagnostic "entry" criteria, (2) efficacy parameters, (3) duration of therapy, (4) degree of antisecretory effect, (5) placebo effect, (6) follow-up data. Gastro-oesophageal reflux disease is now the most frequent upper GI disorder treated by gastroenterologists in Europe and North America. There is still a dearth of information regarding the natural history of the disease. The types of information generated through randomized controlled clinical trials have had only limited applicability to routine clinical practice. In the future, large cooperative databases accumulating the clinical histories of a great variety of gastro-oesophageal reflux disease patients may help to provide us with the much needed insights into the natural history of this common disorder.

Ostreolysin enhances fruiting initiation in the oyster mushroom (Pleurotus ostreatus)

Fruiting initiation in mushrooms can be triggered by a variety of environmental and biochemical stimuli, including substances of natural or synthetic origin. In this work ostreolysin, a cytolytic protein specifically expressed during the formation of primordia and fruit bodies of Pleurotus ostreatus, was applied to nutrient media inoculated with mycelium of P. ostreatus, and its effects on mycelial growth and fructification of the mushroom studied. The addition of ostreolysin slightly inhibited the growth of mycelium, but strongly induced the formation of primordia, which appeared 10 d earlier than in control plates supplemented with bovine serum albumin or with the dissolving buffer alone. Moreover, ostreolysin stimulated the subsequent development of primordia into fruit bodies. However, direct involvement of this protein in the sporulation of the mushroom is unlikely, as it was also detected in large amounts in the non-sporulating strain of P. ostreatus.

Three centuries of stomach symptoms in Scotland

BACKGROUND

Stomach pain and discomfort have been reported since antiquity.

AIM

To follow the time trends since the 18th century of dyspepsia, gastric ulcer, duodenal ulcer, and benign oesophageal disease to test when dyspepsia started to become a major clinical problem.

METHODS

The annual in- and out-patient records of the last three centuries from the Scottish Royal Infirmaries of Edinburgh, Aberdeen, Glasgow and Dundee were analysed. In addition, dispensary attendances, clinicians' casebooks, students' notebooks and medical texts have been scrutinized for historic statistics of upper gastrointestinal disease.

RESULTS

Dyspepsia was first recorded in the 1750s and increased markedly subsequently. Such dyspepsia persisted after gastric and duodenal ulcers appeared in the late 19th century and then declined again in the late 20th century. Non-ulcer dyspepsia has remained the commonest diagnosis made after endoscopy for stomach pain in the beginning of the 21st century.

CONCLUSION

The current commonest diagnosis of stomach pain, dyspepsia dates from the mid-18th century. Any explanations of its causation need to consider this timing.

Personal view: the paradox of runaway competitions in gastroenterology

Occasionally, gastroenterologists harbour reservations about the appropriateness of various procedures and management options, yet find themselves drawn into a competition and forced by outside exigencies to provide such services. The aim of the present analysis was to describe patterns of runaway competitions and factors that influence their occurrence in gastroenterology. The interactions between two physicians or physician and patient are modelled as non-zero-sum games of two players. The outcomes associated with two behavioural strategies of two players are arranged in a two-by-two game matrix. Many scenarios of clinical gastroenterology and social interactions among gastroenterologists are characterized by the underlying game of prisoner's dilemma, where two players can choose to co-operate or compete with each other. Although from their joint perspective co-operation results in a higher joint utility, the perspective of each individual favours competition. Following the inescapable logic of their individual perspective, the players end up with a worse outcome than through co-operation. A runaway competition ensues if the game is played repeatedly with players successively increasing their stakes. Ultimately, each player tries to outdo the opponent while heading in the wrong direction. Recognizing the hallmarks of the game of prisoner's dilemma may help gastroenterologists to avoid such competitions.

Personal view: Why is my GI clinic filled with surgical mishaps? Post-operative syndromes as an externality problem

The aim of the present analysis was to review why gastroenterology clinics appear filled with patients suffering from postsurgical syndromes. The long-term sequelae of gastrointestinal surgery can be modelled as a negative production externality of surgical operations. When seeking to maximize their profits, surgeons are primarily concerned with the price and cost of surgery alone. They tend to ignore parts of the ensuing long-term costs they impose through postsurgical syndromes on other medical specialties. The complication-related rise in the cost of gastroenterology practice reflects parts of the societal costs of surgery that are not included on the surgical balance sheet. To the surgeon, surgery appears cheaper than to the rest of the medical community, because cost shifting from surgery to other medical specialties leads to a favourable surgical outcome with more surgical operations performed than medically needed or economically feasible. The amount of surgical sequelae could drop, if surgeons were forced to care for all their own postsurgical syndromes or if surgery entered a joint enterprise with gastroenterology caring for the same patient pool.

Helicobacter pylori-associated ulcer bleeding: should we test for eradication after treatment?

BACKGROUND

Eradication of Helicobacter pylori after peptic ulcer haemorrhage reduces the risk of recurrence. Because H. pylori treatment is very effective, it is unclear whether testing to confirm eradication is worthwhile.

AIMS

To examine whether patients with H. pylori-associated peptic ulcer haemorrhage should be tested for successful eradication after completion of antibiotic therapy.

METHODS

A Markov cost-effectiveness model was developed to compare testing vs. non-testing of H. pylori eradication in peptic ulcer haemorrhage. Probability estimates and average costs were derived from published information.

RESULTS

Testing for H. pylori eradication resulted in a benefit of 0.07 quality-adjusted life-years and cost 836 US dollars less than the strategy of not confirming eradication. Testing remained the superior strategy when varying the model regarding age, the initial success of eradication, various test and retreatment strategies, and the rate and costs of recurrent bleeding. Assuming a high eradication rate (95%), the test strategy becomes more expensive only if the cost of H. pylori testing reaches 265 US dollars; however, even under these conditions it remains cost-effective.

CONCLUSIONS

Patients with H. pylori-associated peptic ulcer bleeding should be tested to confirm eradiation of H. pylori after completion of antibiotic treatment.

Personal view: passing the buck and taking a free ride -- a game-theoretical approach to evasive management strategies in gastroenterology

BACKGROUND

'Free-riding' physicians enjoy the status, prestige and income of their profession without fully contributing to its overall mission. By shifting the costs of potential medical complications and difficult patient encounters to other physicians, they reap the benefits of their profession without carrying its full weight.

AIM

To describe this phenomenon in terms of decision analysis and characterize the parameters affecting its occurrence.

METHODS

The interaction between two physicians is modeled as a non-zero-sum game. Two strategies of either contributing to patient management or taking a free ride are available to both physicians. The four possible outcomes are arranged in a two-by-two game matrix.

RESULTS

Physicians practice medicine because their personal benefit exceeds their cost. High cost to the physician results in a high probability of taking a free ride and copping out from potentially risky management. Increasing the benefit decreases the probability of free riding. As the number of possible encounters with other physicians increases, the probability of free riding increases and the probability for effective management by each individual physician decreases.

CONCLUSION

If individual gastroenterologists felt less threatened by administrative repercussions and medico-legal consequences of untoward events, each one of them would contribute more to effective patient management.

Personal view: victim blaming as management strategy for the gastroenterologist--a game theoretical approach

BACKGROUND

A multitude of digestive diseases elude simple management strategies. Rather than admit failure of disease management, a gastroenterologist could resort to blaming patients for their own medical conditions. Blaming the patient constitutes an easy exit strategy for otherwise unsolvable disease conditions.

AIM

To shed light on the problem of patient blaming in gastroenterology and provide means for its resolution.

METHODS

The interaction between physician and patient can be formulated in terms of a non-zero-sum game between two adversaries. The outcomes associated with two behavioural strategies available to both adversaries are arranged in a two-by-two game matrix.

RESULTS

Blaming the patient is characterized by the general game pattern of the 'prisoner's dilemma'. If the physician-patient interaction is restricted to one single event, patient blaming represents the management strategy of choice with the highest expected payoff under all foreseeable circumstances. If there is a high probability for repeated physician-patient interactions, however, a physician admitting and a patient accepting the limits of medical performance yield a dominant strategy.

CONCLUSION

Only for single physician-patient encounters does a non-cooperative strategy of blaming one's adversary for a poor medical outcome yield the highest expected outcome. In the long run, the strategy of shifting blame becomes unproductive for both sides alike.

Why do complications of gastrointestinal disease and procedures come as serial rather than singular events?

BACKGROUND

It often appears as if complications arising from gastrointestinal disease and interventional procedures come in 'series' and 'cluster' in individual patients.

AIM

The aim of this study was to analyse the clustering of complications in terms of stochastic modelling and Markov chains.

METHODS

A patient with gastrointestinal disease is simulated to move along either a 'bad track' associated with multiple consecutive complications or a 'good track' free of complications, the transitions within each track and between the two tracks being governed by probability values.

RESULTS

Because the occurrence of a single complication increases the risk of further complications, subjects who encounter their first complication are more likely to experience a second, third or even more complications, before they leave the 'bad track' and their personal chain of cascading complications becomes discontinued. The model of a Markov chain explains why the overall number of complications in the total population of patients with digestive disease remains low even if individual patients are expected to encounter more than a single complication.

CONCLUSIONS

Published complication rates for gastrointestinal procedures underestimate the true risk to the patient, because they do not consider the added vulnerability to cascading complications after the first event.

Personal view: cost and benefit of medical rituals in gastroenterology

BACKGROUND

Unable to resolve a medical problem, gastroenterologists occasionally choose an ineffectual intervention instead. The elusive path to effectual management becomes substituted with an ineffectual but readily available medical ritual. The term 'ritual' refers to the utilization of an ineffectual intervention with little chances of achieving a medically relevant goal.

AIM

The aim of the article is to analyse the cost-benefit relationship of rituals in gastroenterology and the reasons why gastroenterologists utilize them.

METHODS

Ritualistic disease management is described in terms of medical decision and threshold analysis.

RESULTS

If the perceived benefit of a ritual exceeds its cost, the ineffectual path becomes more attractive than expectant management or doing nothing. To engage in an ineffectual intervention, the threshold probability for success needs to exceed its cost-benefit difference divided by the benefit associated with success. In choosing an ineffectual intervention, doctors tend to underestimate the true costs of a ritual and overestimate its probability of success. The availability of an effectual path leads to more stringent conditions for the benefit associated with an ineffectual path.

CONCLUSIONS

A better understanding of their economical underpinnings should lead to more restricted utilization of rituals in gastroenterology, especially, in situations where they drain scarce resources disproportionately to their perceived benefit.

Review article: anti-reflux surgery and endoluminal therapies

In the short term, fundoplication and antisecretory medication are equally effective in the management of gastro-oesophageal reflux disease. However, over the long term, the fundoplication wrap tends to become loose, and many surgical patients continue to take antisecretory medication after surgery. The operation is technically complex and takes a long time to learn. Inexperience of the individual surgeon is a major factor contributing to the occurrence of postsurgical complications. Fundoplication does not prevent the occurrence of Barrett's oesophagus nor its progression to oesophageal adenocarcinoma. There is no evidence to suggest that the procedure is less costly or more cost-effective than long-term maintenance therapy with antisecretory medications, especially if surgical failures and postsurgical complications are taken into account. Fundoplication represents an alternative to medical therapy in patients with gastro-oesophageal reflux disease who cannot or do not want to be on long-term maintenance therapy with antisecretory medication. Endoluminal procedures, such as radiofrequency ablation, endoscopic suturing and injection at the gastro-oesophageal junction, work only in mild forms of reflux disease. They fail to provide complete relief of reflux symptoms and do not heal erosive oesophagitis. All endoluminal procedures would have to undergo major technological improvements before they could become comparable with fundoplication or antisecretory therapy.

Review article: trials on reflux disease -- the role of acid secretion and inhibition

The importance of gastric acid in the pathophysiology of gastro-oesophageal reflux disease is substantiated by the extraordinary therapeutic success of acid inhibition in the management of the disease. The influence of many risk factors for gastro-oesophageal reflux disease is also mediated through their effect on gastric acid secretion and acid reflux. Helicobacter pylori reduces the risk of gastro-oesophageal reflux disease by causing corpus gastritis and reducing gastric acid output. The geographical and temporal trends of H. pylori infection in human populations and its influence on gastric acid secretion are responsible for much of the apparent epidemiology of gastro-oesophageal reflux disease. On average, intra-oesophageal exposure to acid is higher in patients who respond poorly to antisecretory medication. It also tends to increase with increasing severity of reflux disease. However, gastric acid secretion and intra-oesophageal acid exposure vary markedly in reflux patients. The degrees of gastric or intra-oesophageal acidity do not allow the prediction of the presence or severity of gastro-oesophageal reflux disease in the individual subject. The many clinical trials on gastro-oesophageal reflux disease indicate that the reflux of gastric acid constitutes an essential mechanism in the development of this disease, but that additional and partly unknown risk factors must contribute to its aetiology and promote its occurrence in the individual patient.

Ultrastructural localization of integrin subunits alpha3 and alpha6 in capillarized sinusoids of the human cirrhotic liver

Normal liver sinusoids are not lined by a basement membrane (BM). In contrast, in the course of development of liver cirrhosis, a structured BM is formed de novo in the space of Disse. This BM contributes to the inhibition of the metabolic function of the liver but the pathogenic background of the formation of this perisinusoidal BM is still unclear. Integrins of the beta1-class are generally essential for BM stability and some of them (such as alpha2beta1, alpha3beta1 and alpha6beta1) appear de novo in the perisinusoidal space of the cirrhotic liver. Their cellular distribution in capillarized sinusoids as well as the correlation between their cellular distribution and the formation of the microvascular BM in the cirrhotic liver has not been shown at the ultrastructural level. In the present work we aimed to clarify this issue. We focused on integrins alpha3beta1 and alpha6beta1 and localised them ultrastructurally in human cirrhotic liver microvessels using postembedding immunogold which allows the ultrastructural localization of antigens with high resolution in the tissue. The newly formed basement membrane of capillarized sinusoids was visualized by means of fixation with addition of tannic acid, which enables the visualization of structures of the extracellular matrix with the highest resolution. Also, we carried out laminin detection using postembedding immunogold. Our results show that both alpha3beta1 and alpha6beta1 are expressed on the surface of both hepatocytes and endothelial cells, i.e. on both sides of the newly formed basement membrane. This latter shows zones of higher density both in close proximity to the endothelial and to the hepatocytic surfaces which resemble laminae densae. We propose that hepatocytes and endothelial cells may, therefore, by expressing such integrins, contribute to the formation of this pathological BM in the microvessels of the human cirrhotic liver. On stellate cells, which are major producers of BM components, both integrins alpha3beta1 and alpha6beta1 were also localized.