Review article: Helicobacter pylori and gastric adenocarcinoma

Gastric Dystemperament (Sue-mizaj) in Iranian Traditional Medicine

Background:

The stomach plays a vital role in the human body. Its clinical problems are very prevalent.

:

Nowadays, new branches of science have emerged because of human individual differences. Many medical schools such as Iranian Traditional Medicine (ITM) established the basis for the prevention, diagnosis, and treatment based on individual differences.

Objective:

The purpose of this study is to summarize identification indices of Gastric Dystemperament to help in better diagnosis.

Methods:

This was a qualitative review study. Definitions and symptoms of Stomach Dystemperament were derived from reliable sources of ITM from 900 AD to 1900 AD (Kamil-al-sinaa al Tibbiya, Teb-e-Akbari, Exir Azam, Al-Qanun fi al tibb, Mansouri Fi-al-teb, Al-Havi, Zakhire Kharazmshahi, Hidayat al-Muta’allemin fi al-tibb, Ferdos al-Hekmat fi al-tib, Sharh Al Qurashi al-Qanun, Sharh-e asbab al-Alamat) and English and Persian indices.

Results:

The most important factors and symptoms to be considered as gastric dystemperament include digestion, thirst, appetite, belching, bloating, gastric emptying time, burning stomach, reflux, gastric pain, the effect of food quality (coldness, heat, wet, dryness), mouth moisture and taste, tongue and mouth status, quality of body waste material (urine, stool), and palpation of the stomach area.

Conclusion:

Iranian Traditional Medicine sources have mentioned the indicators of gastric dystemperament, which can be used for more effective diagnosis and treatment and even prevention of gastric diseases.

Tropism for Spasmolytic Polypeptide-Expressing Metaplasia Allows Helicobacter pylori to Expand Its Intragastric Niche

BACKGROUND & AIMS

In patients with chronic Helicobacter pylori (H pylori) infection, parietal and chief cell atrophy in the gastric corpus, a process known as spasmolytic polypeptide-expressing metaplasia (SPEM), increases the risk for progression to cancer. The relation between H pylori and these metaplastic changes is unclear. We investigated whether H pylori localizes to regions of SPEM.

METHODS

We developed an in situ adherence assay in which we incubated H pylori with free-floating tissue sections from the gastric corpora of mice; we assessed H pylori distribution along the gastric unit by immunofluorescence. We analyzed the interactions of H pylori with tissue collected from mice with acute SPEM, induced by high-dose tamoxifen. We also evaluated how adhesin-deficient H pylori strains, chemical competition assays, and epithelial glycosylation affected H pylori adhesion to SPEM glands. Mice colonized with the mouse-adapted PMSS1 strain were analyzed for H pylori colonization in vivo during tamoxifen-induced SPEM or after decrease of stomach acid with omeprazole.

RESULTS

Compared with uninjured glands, H pylori penetrated deep within SPEM glands, in situ, through interaction of its adhesin, SabA, with sialyl-Lewis X, which expanded in SPEM. H pylori markedly increased gastric corpus colonization when SPEM was induced, but this proximal spread reversed in mice allowed to recover from SPEM. Decreasing corpus acidity also promoted proximal spread. However, H pylori penetrated deep within corpus glands in vivo only when sialyl-Lewis X expanded during SPEM.

CONCLUSIONS

Helicobacter pylori differentially binds SPEM glands in situ and in mice, in large part by interacting with sialyl-Lewis X. Our findings indicate that H pylori expands its niche into the gastric corpus by promoting and exploiting epithelial metaplastic changes that can lead to tumorigenesis.

Acid and the basis for cellular plasticity and reprogramming in gastric repair and cancer

Subjected to countless daily injuries, the stomach still functions as a remarkably efficient digestive organ and microbial filter. In this Review, we follow the lead of the earliest gastroenterologists who were fascinated by the antiseptic and digestive powers of gastric secretions. We propose that it is easiest to understand how the stomach responds to injury by stressing the central role of the most important gastric secretion, acid. The stomach follows two basic patterns of adaptation. The superficial response is a pattern whereby the surface epithelial cells migrate and rapidly proliferate to repair erosions induced by acid or other irritants. The stomach can also adapt through a glandular response when the source of acid is lost or compromised (that is, the process of oxyntic atrophy). We primarily review the mechanisms governing the glandular response, which is characterized by a metaplastic change in cellular differentiation known as spasmolytic polypeptide-expressing metaplasia (SPEM). We propose that the stomach, like other organs, exhibits marked cellular plasticity: the glandular response involves reprogramming mature cells to serve as auxiliary stem cells that replace lost cells. Unfortunately, such plasticity might mean that the gastric epithelium undergoes cycles of differentiation and de-differentiation that increase the risk of accumulating cancer-predisposing mutations.

Regenerative proliferation of differentiated cells by mTORC1-dependent paligenosis

In 1900, Adami speculated that a sequence of context-independent energetic and structural changes governed the reversion of differentiated cells to a proliferative, regenerative state. Accordingly, we show here that differentiated cells in diverse organs become proliferative via a shared program. Metaplasia-inducing injury caused both gastric chief and pancreatic acinar cells to decrease mTORC1 activity and massively upregulate lysosomes/autophagosomes; then increase damage associated metaplastic genes such as Sox9; and finally reactivate mTORC1 and re-enter the cell cycle. Blocking mTORC1 permitted autophagy and metaplastic gene induction but blocked cell cycle re-entry at S-phase. In kidney and liver regeneration and in human gastric metaplasia, mTORC1 also correlated with proliferation. In lysosome-defective Gnptab-/- mice, both metaplasia-associated gene expression changes and mTORC1-mediated proliferation were deficient in pancreas and stomach. Our findings indicate differentiated cells become proliferative using a sequential program with intervening checkpoints: (i) differentiated cell structure degradation; (ii) metaplasia- or progenitor-associated gene induction; (iii) cell cycle re-entry. We propose this program, which we term "paligenosis", is a fundamental process, like apoptosis, available to differentiated cells to fuel regeneration following injury.

A novel fluorescent DNA sensor for ultrasensitive detection of Helicobacter pylori

In this work, a novel fluorescent DNA sensor for ultrasensitive detection of Helicobacter pylori (H. pylori) DNA was developed. This strategy took advantage of DNA hybridization between single-stranded DNA (ssDNA, which had been designed as an aptamer specific for H. pylori DNA) and the complementary target H. pylori DNA, and the feature that ssDNA bound to graphene oxide (GO) with significantly higher affinity than double-stranded DNA (dsDNA). ssDNA were firstly covalent conjugated with CuInS₂ quantum dots (QDs) by reaction between the carboxy group of QDs and amino group modified ssDNA, forming ssDNA-QDs genosensor. In the absence of the complementary target H. pylori DNA, GO could adsorb ssDNA-QDs DNA sensor and efficiently quench the fluorescence of ssDNA-QDs. While the complementary target H. pylori DNA was introduced, the ssDNA-QDs preferentially bound with the H. pylori DNA. The formation of dsDNA would alter the conformation of ssDNA and disturb the interaction between ssDNA and GO. Thus, the dsDNA-QDs/GO system exhibited a stronger fluorescence emission than that of the ssDNA-QDs/GO system. Under the optimized conditions, a linear correlation was established between the fluorescence intensity ratio I/I₀ and the concentration of H. pylori DNA in the range of 1.25-875pmolL^-1 with a detection limit of 0.46pmolL^-1. The proposed method was applied to the determination of H. pylori DNA sequence in milk samples with satisfactory results.

LACK OF ASSOCIATION BETWEEN HELICOBACTER PYLORI'S VIRULENCE AND INCREASED SERUM C-REACTIVE PROTEIN LEVELS IN FUNCTIONAL DYSPEPTIC PATIENTS

ABSTRACT Background Recently, a great variety of studies aimed to investigate and even suggestHelicobacter pylori as an important key factor in gastrointestinal and non-gastrointestinal events development. The well-established relationship between bacterial virulence and increased risk for peptic ulcer or gastric carcinoma is not so clear when comparing inflammation markers alterations, such C-reactive protein, with the pathogen. Objective The objective of this study was to evaluate the presence of H. pylori, bacterial virulence and C-reactive protein serum levels in individuals diagnosed with functional dyspepsia. Methods Were prospectively included in this study 489 dyspeptic individuals. They fulfill Rome III clinical criteria for the diagnosis of functional dyspepsia with no organic disease at endoscopy. The bacterial infection was established by histology and urease rapid test. The levels of serum C-reactive protein were obtained by immunonefelometry and CagA status ofH. pylori positive individuals was determined through an imunoenzimatic assay. Results Prevalence rate of H. pylori was 66.3% and virulence factor CagA was detected in nearly 43% of positive samples. In addition, it has been noticed an association between Ilex paraguariensis(yerba maté) consumption and pathogen's prevalence. An important effect of bacterial infection on inflammation was only observed in gastric epithelium. Conclusion No systemic response to the pathogen, measured through C-reactive protein levels, was observed, regardless of CagA status. Otherwise, the intake of yerba maté should be considered as a cultural factor possibly related toH. pylori's transmission.

Clinical significance of IgG antibody titer against Helicobacter pylori

BACKGROUND

We clarified the clinical significance of measurement of IgG antibody titers against Helicobacter pylori using data from a nested case-control study from a large-scale cohort study in Japan.

METHOD

Participants included 36,745 subjects from the Japan Health Center-based Prospective Study who responded to the baseline questionnaire and provided a blood sample. Subjects were aged 40-69 years and were followed over 15 years after initial sampling. Controls were matched to 511 gastric cancer patients. Plasma surface antigen (Hp)-IgG titer was measured using ELISA, and mucosal atrophy was determined by measuring pepsinogen I and II levels.

RESULTS

Seropositive subjects with low Hp-IgG titer and mucosal atrophy showed a higher risk for gastric cancer than high-titer subjects. Odds ratio (OR) referred to cases with true negative IgG titers and no mucosal atrophy. In moderately atrophic subjects, the low titer OR was 19.0, with a 95% confidence interval (CI) of 7.7-46.9, and 12.5 for high titer, with a 95% CI of 5.2-30.0. In severely atrophic subjects, the low titer OR was almost double that of high-titer subjects (OR = 30.2, 95% CI = 12.4-73.7 and OR = 15.9, 95% CI = 6.3-40.3, respectively). These associations were observed more frequently for differentiated than undifferentiated gastric cancer.

CONCLUSION

Combination assay with Hp-IgG titer and pepsinogens may help identify groups at high risk for gastric cancer. Subjects with low Hp-IgG titer and mucosal atrophy were at extremely high risk for gastric cancer, particularly differentiated cancer. Subjects with this background may require ongoing observation and periodic endoscopic examination for early cancer detection.

Infectious Agents

There is substantial evidence that infectious agents play a causal role in a variety of human malignancies. These cancers include the liver, cervix, stomach, nasopharynx, bladder, and bile duct as well as Kaposi sarcoma (KS) and several lymphomas. This chapter summarizes the biological and epidemiologic features of each of the major oncogenic infections, beginning with the viruses, followed by H. pylori, and with a brief summary of the relevant parasites.

Biomarkers in various types of atrophic gastritis and their diagnostic usefulness

Atrophic gastritis has been shown to involve either the oxyntic gland area, resulting in hypergastrinemia and hypopepsinogenemia I, the antral gland area, causing hypogastrinemia without change in serum pepsinogen I (diffuse antral gastritis; DAG), or the entire gastric mucosa (multifocal atrophic gastritis; MAG), resulting in both hypogastrinemia and hypopepsinogenemia I; and rare atrophic gastritis limited to the oxyntic gland area, with antibodies against oxyntic cells and/or intrinsic factor (autoimmune metaplastic atrophic gastritis; AMAG). This study was performed on 126 patients with various forms of gastritis and on 126 age- and gender-matched controls, who were subjected to endoscopy with biopsy, H. pylori testing (13C-UBT, serology), assays for serum gastrin and pepsinogen I, and testing for basal and pentagastrin-induced gastric acid secretion. The following groups of patients were examined: group I (N = 22), with AMAG; group II (N = 53), with DAG; group III (N = 51), with MAG; and group IV (N = 126), age- and gender-matched controls without gastritis. The following changes were found. In group I very high serum gastrin and very low pepsinogen I were observed, and all patients were achlorhydric and H. pylori negative. In group II, with low serum gastrin and normal pepsinogenemia and gastric chlorhydria, all patients were H. pylori positive. In group III, with lower serum gastrin and lower pepsinogen I levels and reduced chlorhydria, all patients were also H. pylori positive. And all group IV controls, with normal serum gastrin and pepsinogen I and normal gastric acid secretion without antral or fundic gastritis, were H. pylori negative. We conclude that measurements of serum gastrin and pepsinogen I and gastric acid secretion as well as testing for H. pylori infection may be useful in noninvasive diagnosis of various types of atrophic gastritis and in identification of patients with premalignant gastritis and a high risk of gastric cancerogenesis.

Functional characterization of Helicobacter pylori DnaB helicase

Helicobacter pylori causes gastric ulcer diseases and gastric adenocarcinoma in humans. Not much is known regarding DNA replication in H.pylori that is important for cell survival. Here we report the cloning, expression and characterization of H.pylori DnaB (HpDnaB) helicase both in vitro and in vivo. Among the DnaB homologs, only Escherichia coli DnaB has been studied extensively. HpDnaB showed strong 5' to 3' helicase and ATPase activity. Interestingly, H.pylori does not have an obvious DnaC homolog which is essential for DnaB loading on the E.coli chromosomal DNA replication origin (oriC). However, HpDnaB can functionally complement the E.coli DnaB temperature-sensitive mutant at the non-permissive temperature, confirming that HpDnaB is a true replicative helicase. Escherichia coli DnaC co-eluted in the same fraction with HpDnaB following gel filtration analysis suggesting that these proteins might physically interact with each other. It is possible that a functional DnaC homolog is present in H.pylori. The complete characterization of H.pylori DnaB helicase will also help the comparative analysis of DnaB helicases among bacteria.