Gastroenterology and Hepatology from Bed to Bench

without abstract

Gastric cancer (GC) is the fifth most common cancer in the world and has the third highest mortality rates, for both sexes. In 2012, just fewer than 1,000,000 new cases of GC were diagnosed, and 723,000 deaths were attributable to it. Helicobacter pylori (H. pylori) plays a predominant role in the aetiology of GC and was characterised as a class I carcinogen by the World Health Organisation in 1994 . H. pylori is a microaerophilic gram-negative bacterium that colonises the gastric mucosa of 50% of the world’s population. The majority of infections are asymptomatic, hence screening and treatment programmes cannot be justified except for high-risk patients .

Gastric adenocarcinoma is a common malignancy with high rate among other cancers in the world and many ethological causes have been introduced for which helicobacter pylori, as a gram-negative bacterium has been considered as an important pathological facilitating factor. This agent is also associated with more different digestive diseases, such as gastritis, peptic ulcer, mucosa-associated lymphoid tissue lymphoma. Recently some molecular aspects have been described by scientists which show role of some apoptotic genes and proteins for example:P53, Bcl2 ,C-Myc and Rb-suppressor systems in H pylori pathogenesis .Also the relationship between nitric oxide( NOSi genotype) with H pylori genes has been demonstrated in some studies, This mini-review has been aimed to explain better these  genetically aspects of Pylori pathogenesis.

Aim: the objective of this study was to evaluate the time trend of Helicobacter pylori (H. pylori) prevalence and presence of intestinal Metaplasia over the period of 7 years in gastritis Iranian patients.

Background: H. pylori are the major causal factor in chronic gastritis. Its acquisition leads to a chronic, usually lifelong, inflammation of the gastric mucosa, which may gradually progress to atrophy with intestinal metaplasia in a significant proportion of infected individuals.

Patients and methods: H. pylori and intestinal Metaplasia data among 14,860 consecutive gastritis patients, who referred to the gastrointestinal department of Tehran’s Taleghani Hospital in Iran, was examined across the sex and age group. The patients were divided into 6 age groups (16-30, 30-40, 40-50, 50-60 and >70).

Results: The overall prevalence rate among patient with H. pylori infection was 83.5% (12406/14860) and 11,394 (84.1%) of them were related to the gastritis. The prevalence rate of H. pylori among patient with severe gastritis significantly higher (P<0.05) compared to mild and moderate gastritis. In addition, the prevalence decreased with age and also has declined in recent years. Presence of intestinal metaplasia increased with age (P<0.05).

Conclusion: The results of this study showed that the prevalence of H. pylori infection in Iranian population has declined in recent years; nevertheless it seems to be highly prevalent in Iran. We also find a significant positive relationship between H. pylori infection and gastritis. There is no association between sex and infection but in contrast with the most studies its prevalence decreased with age.

Aim: The current investigation aimed to evaluate ruminant raw milk as a reservoir source of this bacterium and analyze the diversity of cagA and vacA genotypes as H. pylori virulence factors to find any relationship between these genotypes in human and animal H. pylori strains.

Background: The way of transmission of Helicobacter pylori as one of the most controversial bacteria in the world which colonizes the human gastric tissue and is responsible for several gastric diseases is still unknown. The possibility of zoonotic transmission of H. pylori is feasible, but is not proven in ruminant reservoirs.

Materials and methods: Overall 210 cow, sheep, goat, camel and buffalo raw milk samples and 100 human gastric biopsy played role in this survey. We applied PCR assays to identify H. pylori, vacA and cagA genes. Statistical tests were applied for data analysis.

Results: Totally 12(16%) cow, 8(13.79%) sheep, 2 (4.76%) goat, 2(13.33%), buffalo 4(20%) and 82 (82%) of human specimens were confirmed to be H. pylori positive. Among which s1a/m2 genotype was more frequent in isolated H. pylori strains and was statistically meaningful between strains. Based on statistical analyses the s1b allele of sheep had meaningful relationship with human strains.

Conclusions: The current survey was prompted by our previous report, According to both results we can conclude that may be sheep act as a reservoir for H. pylori and transmit this bacterium to human via its milk. Extended assessments in other geographical regions and other animals is recommended.

AbstractBackground: Pathogenicity ofthe Helicobacter pylori-cagA positive was associated with EPIYAmotifs and higher number of EPIYA-C segments is a risk for gastric cancer,while duodenal ulcer-promoting gene (dupA) is determinedas a protective factor against gastric cancer. Our aim was to determine the EPIYA-cagAPhosphorylation sites and dupA gene in H. pylori isolates amongpatients with upper gastrointestinal diseases. Materials and methodsA total of 128 non repeated gastric biopsies obtained from patientsundergoing endoscopy were included in the study from January 2013 till July2013. Samples were cultured on selective horse blood agar. Isolated organismswere identified as H. pylori by Gram staining and positive oxidase,catalase, and urease tests. Variousmotif types of cagA and prevalence of dupA were determined by PCR method.  ResultsOf 120 H. pylori isolates,35.9% were dupA positive and 56.26% werecagA positive, while cagAwithABC and ABCC motifswere 55.5% and 44.5%, respectively. Fifty six percent of isolates with the ABCC motif have had dupAgenesand we also found a significant relationship betweenstrains with genotypes of dupA-ABCand DU disease (p = 0.007). ConclusionTheresults of this study showed that theprevalence of cagA-positive H. pylori in Shiraz are as high as inwestern countries and Higher numbers of EPIYA-C segments were seen in GCpatients. Wealso can use dupA as a prognosticand pathogenic marker for duodenal ulcer disease and cagA with the segment C forgastric cancer and gastric ulcer in thisregion.

Aim: The purpose of this investigation was to determine the oipA and dupA genes of Helicobacter pylori isolates from west of Iran; Chaharmahalo Bakhtiyari region and find their relationship with the severity of the gastroduodenal diseases.

Background: Helicobacter pylori is an organism responsible for many gastroduodenal diseases. Studies suggest that genetic diversity in H. pylori virulence factors such as oipA and dupA genes is high among isolates of different geographic regions and may cause more severe diseases.

Methods: In this cross-sectional study, gastric biopsy specimens were taken from 150 patients with gastroduodenal diseases. The specimens were processed for DNA extraction. The presence of ureC, dupA and oipA genes was tested by polymerase chain reaction (PCR). Statistical analyses were performed to investigate the relationships between genotypes and gastric disorders. Results: Overall, 123 (82%) H. pylori strains were isolated from 150 specimens. dupA gene was detected in 41 (33.33%) of H.pylori-positive specimens. There was a reverse correlation between this gene and gastric cancer. The oipA gene was found in 88 (71.54%) of samples and statistically there was no association between this gene and gastric disorders. As statistical analyses revealed, presence of the dupA were more common in isolates with the oipA negative. Conclusions: Based on our findings, it seems that the presence of dupA gene can be considered as a marker for the onset of severe diseases. However, extended molecular epidemiology research in other populations is recommended.

Aim: The aim of this study was to evaluate the Helicobacter pylori eradication in the group receiving standard -dose twice a day for two weeks and continue taking amoxicillin for 4 weeks.

Background: Helicobacter pylori is the major etiological cause of chronic gastritis, gastric and duodenal ulcers, gastric cancer and lymphoma and therefore, patient should be treated after diagnosis of H. pylori infection.

Patients and Method: A total of 66 consecutive patients with rapid urease test during endoscopy or biopsy positive for H. pylori were enrolled in this clinical trial study during 2013-2014. Patients were divided randomly into two groups. Group A (standard dose) received omeprazole (20 mg), amoxicillin (1 g), and clarithromycin (500 mg), all twice daily for two weeks. Group B received standard dose like group A and in patients with H.pylori infection but amoxicillin were continued for 4 weeks. After completion of treatment, patients did not receive any treatment for a month and then stool antigen was performed to evaluate the H.pylori.

Results: The rate of successful HP eradication was significantly higher in group A (90.9% V.s 63.6%; p=0.017). Inflation and bitter mouth were found in 8 and 13 patients in group A and 7 and 9 patients in group B, respectively. The incidence of adverse effects was the same (p=0.437).