Non-microbial approach for Helicobacter pylori as faster track to prevent gastric cancer than simple eradication

Although the International Agency for Research on Cancer declared Helicobacter pylori(H.pylori)as a definite human carcinogen in 1994,the Japanese Society for Helicobacter Research only recently(February 2013)adopted the position that H.pylori infection should be considered as an indication for either amelioration of chronic gastritis or for decreasing gastric cancer mortality.Japanese researchers have found that H.pylori eradication halts progressive mucosal damage and that successful eradication in patients with non-atrophic gastritis most likely prevents subsequent development of gastric cancer.However,those who have already developed atrophic gastritis/gastric atrophy retain potential risk factors for gastric cancer.Because chronic perpetuated progression of H.pylori-associated gastric inflammation is associated with increased morbidity culminating in gastric carcinogenesis,a non-microbial approach to treatment that provides long-term control of gastric inflammation through nutrients and other interventions may be an effective way to decrease this morbidity.This non-microbial approach might represent a new form of prerequisite"rescue"therapy that provides a quicker path to the prevention of gastric cancer as compared to simple eradication.     

Curcumin as a potential therapeutic candidate for Helicobacter pylori associated diseases

Curcumin, a yellow pigment and principal polyphenolic Curcuminoid obtained from the turmeric rhizome Curcuma longa, is commonly used as a food-coloring agent. Studies suggest that curcumin has a wide range of beneficial properties e.g., anti-inflammatory, anti-oxidant, anti-cancer, anti-proliferative, anti-fungal and anti-microbial. These pleiotropic activities prompted several research groups to elucidate the role of curcumin in Helicobacter pylori (H. pylori) infection. This is the first review with this heading where we discussed regarding the role of curcumin as an anti-H. pylori agent along with its potential in other gastrointestinal diseases. Based on several in vitro, early cell culture, animal research and few pre-clinical trials, curcumin projected as a potential therapeutic candidate against H. pylori mediated gastric pathogenesis. This review sheds light on the anti-H. pylori effects of curcumin in different models with meticulous emphasis on its anti-oxidant, anti-inflammatory and anti-carcinogenic effects as well as some critical signaling and effecter molecules. Remarkably, non-toxic molecule curcumin fulfills the characteristics for an ideal chemopreventive agent against H. pylori mediated gastric carcinogenesis but the foremost challenge is to obtain the optimum therapeutic levels of curcumin, due to its low solubility and poor bioavailability. Further, we have discussed about the possibilities for improving its efficacy and bioavailability. Lastly, we concluded with the anticipation that in near future curcumin may be used to develop a therapeutic drug against H. pylori mediated gastric ailments through improved formulation or delivery systems, facilitating its enhanced absorption and cellular uptake.     

阿米替林对动力障碍型非溃疡性消化不良运动功能影响的临床研究

目前有人提出用新的超声检查法观察胃的排空功能，并取得成功。本文介绍46例动力障碍型非溃疡性消化不良患者，用阿米替林治疗并用超声检查法观察胃排空变化，结果发现阿米替林能使患者胃排空加速，临床症状缓解，46例中有效者为39例，有效率达85％。作者机理可能为阿米替林作用于胃肠道5－羟色胺受体，使胃排空恢复正常。     

Current status in remnant gastric cancer after distal gastrectomy

Remnant gastric cancer(RGC) and gastric stump cancer after distal gastrectomy(DG) are recognized as the same clinical entity. In this review, the current knowledges as well as the non-settled issues of RGC are presented. Duodenogastric reflux and denervation of the gastric mucosa are considered as the two main factors responsible for the development of RGC after benign disease. On the other hand, some precancerous circumstances which already have existed at the time of initial surgery, such as atrophic gastritis and intestinal metaplasia, are the main factors associated with RGC after gastric cancer. Although eradication of Helicobacter pylori(H. pylori) in remnant stomach is promising, it is still uncertain whether it can reduce the risk of carcinogenesis. Periodic endoscopic surveillance after DG was reported useful in detecting RGC at an early stage, which offers a chance to undergo minimally invasive endoscopic treatment or laparoscopic surgery and leads to an improved prognosis in RGC patients. Future challenges may be expected to elucidate the benefit of eradication of H. pylori in the remnant stomach if it could reduce the risk for RGC, to build an optimal endoscopic surveillance strategy after DG by stratifying the risk for development of RGC, and to develop a specific staging system for RGC for the standardization of the treatment by prospecting the prognosis.     

Polymorphism in the interleukin-17A promoter contributes to gastric cancer

AIM:To evaluate the contribution of the G-197A polymorphism in the interleukin-17(IL-17)promoter region to gastric cancer risk in an Iranian population.METHODS:We performed a case control study using samples from 161 individuals with gastric cancer and171 healthy controls.For each individual,the G-197A genotype was determined by restriction fragment length polymorphism analysis of polymerase chain reaction-amplified fragments.Statistical analyses were performed to determine whether any demographic or behavioral factors,infection with Helicobacter pylori(H.pylori),or a particular G-197A genotype was associated with gastric cancer risk.RESULTS:We found that the G-197A genotype wassignificantly associated with increased gastric cancer risk(P=0.001).Patients who were homozygous(AA)at position-197 were 2.9 times more likely to develop disease(95%CI:1.56-5.4;P=0.001).Furthermore,logistic regression analysis revealed that the presence of a single A allele increased the risk of gastric cancer up to 1.7-fold(95%CI:1.26-2.369;P=0.001).This association was observed for early stage gastric adenocarcinomas only,and was not linked to H.pylori infection.CONCLUSION:These results suggest that carrying one or more G-197A polymorphisms at position-197 in the IL-17 promoter region significantly increases gastric cancer risk in this patient population.     

Helicobacter pylori vaccination: Is there a path to protection?

Helicobacter pylori (H. pylori) is a pathogenic, extracellular bacterium that colonizes the stomach in approximately 50% of the world population. It strongly interacts with the gastric epithelium and mostly causes asymptomatic gastritis. The colonization of H. pylori leads to ulcer development in around 20% of infected patients and may progress to gastric cancer or mucosa-associated lymphoid tissue lymphoma in 1%. Thus, H. pylori is the major cause of gastric cancer worldwide. It has been classified as a class I carcinogen by the World Health Organization. Since its discovery in the early eighties by Warren and Marshall, research has been focused on the investigation of H. pylori biology, host-pathogen interaction, prevention and treatment. Although H. pylori induces a strong humoral and local cellular immune response, the pathogen is not cleared and establishes a chronic infection after encounters in childhood. The ability to colonize the stomach is mediated by several virulence factors that change the host environment, promote adhesion to the epithelium, influence the gastric inflammation and induce immune evasion. H. pylori can be eradicated by antibiotic treatment in combination with a proton-pump inhibitor, but efficacy is decreasing. Current therapies are expensive, have side effects and contribute to increasing antibiotic resistance, underlining the need for novel therapeutics.     

Exploring alternative treatments for Helicobacter pylori infection

Helicobacter pylori(H. pylori) is a successful pathogen that can persist in the stomach of an infected person for their entire life. It provokes chronic gastric inflammation that leads to the development of serious gastric diseases such as peptic ulcers, gastric cancer and Mucosa associated lymphoid tissue lymphoma. It is known that these ailments can be avoided if the infection by the bacteria can be prevented or eradicated. Currently, numerous antibiotic-based therapies are available. However, these therapies have several inherent problems, including the appearance of resistance to the antibiotics used and associated adverse effects, the risk of re-infection and the high cost of antibiotic therapy. The delay in developing a vaccine to prevent or eradicate the infection has furthered research into new therapeutic approaches. This review summarises the most relevant recent studies on vaccine development and new treatments using natural resources such as plants, probiotics and nutraceuticals. In addition, novel alternatives based on microorganisms, peptides, polysaccharides, and intragastric violet light irradiation are presented. Alternative therapies have not been effective in eradicating the bacteria but have been shown to maintain low bacterial levels. Nevertheless, some of them are useful in preventing the adverse effects of antibiotics, modulating the immune response, gastroprotection, and the general promotion of health. Therefore, those agents can be used as adjuvants of allopathic anti-H. pylori eradication therapy.     

Helicobacter pylori-induced inflammation and epigenetic changes during gastric carcinogenesis

The sequence of events associated with the development of gastric cancer has been described as “the gastric precancerous cascade”. This cascade is a dynamic process that includes lesions, such as atrophic gastritis, intestinal metaplasia and dysplasia. According to this model, Helicobacter pylori (H. pylori) infection targets the normal gastric mucosa causing non-atrophic gastritis, an initiating lesion that can be cured by clearing H. pylori with antibiotics or that may then linger in the case of chronic infection and progress to atrophic gastritis. The presence of virulence factors in the infecting H. pylori drives the carcinogenesis process. Independent epidemiological and animal studies have confirmed the sequential progression of these precancerous lesions. Particularly long-term follow-up studies estimated a risk of 0.1% for atrophic gastritis/intestinal metaplasia and 6% in case of dysplasia for the long-term development of gastric cancer. With this in mind, a better understanding of the genetic and epigenetic changes associated with progression of the cascade is critical in determining the risk of gastric cancer associated with H. pylori infection. In this review, we will summarize some of the most relevant mechanisms and focus predominantly but not exclusively on the discussion of gene promoter methylation and miRNAs in this context.     

Factors Influencing the Healing Rate of Gastric Ulcer under Treatment with Cimetidine

Factors influencing the healing rate were evaluated by multivariate analysis on 148 patients with gastric ulcer who were under treatment with cimetidine at a daily dose of 800 mg. Factors used were age, sex, therapeutic environment, duration of present ulcer pain, past history of gastric ulcer, the amount of tobacco, alcohol, and coffee consumed before and during the treatment, the period until symptoms disappeared after the commencement of the treatment, and the characteristics of the ulcers themselves. Of these factors, the five factors that had a significant delaying effect on the healing of gastric ulcers were: 1) having a past history of gastric ulcers, 2) symptoms not disappearing within 1 wk after the commencement of the treatment, 3) size over 20 mm, 4) ulcer located in an angle, and 5) round or oval shape of the ulcer. The patients with less than one of the unfavorable factors (n = 36) had the best healing rate (97.2%), compared with those with two (n = 61), three (n = 39), or four or more (n = 12) unfavorable factors. The healing rate of the latter three groups was 75.4%, 53.8%, and 33.3%, respectively (p less than 0.01). Thus, a prognostic score based on these five factors represents the severity of gastric ulcers with regard to the healing in patients prescribed cimetidine.     

Tight junction disruption: Helicobacter pylori and dysregulation of the gastric mucosal barrier

Long-term chronic infection with Helicobacter pylori (H. pylori) is a risk factor for gastric cancer development. In the multi-step process that leads to gastric cancer, tight junction dysfunction is thought to occur and serve as a risk factor by permitting the permeation of luminal contents across an otherwise tight mucosa. Mechanisms that regulate tight junction function and structure in the normal stomach, or dysfunction in the infected stomach, however, are largely unknown. Although conventional tight junction components are expressed in gastric epithelial cells, claudins regulate paracellular permeability and are likely the target of inflammation or H. pylori itself. There are 27 different claudin molecules, each with unique properties that render the mucosa an intact barrier that is permselective in a way that is consistent with cell physiology. Understanding the architecture of tight junctions in the normal stomach and then changes that occur during infection is important but challenging, because most of the reports that catalog claudin expression in gastric cancer pathogenesis are contradictory. Furthermore, the role of H. pylori virulence factors, such as cytotoxin-associated gene A and vacoulating cytotoxin, in regulating tight junction dysfunction during infection is inconsistent in different gastric cell lines and in vivo, likely because non-gastric epithelial cell cultures were initially used to unravel the details of their effects on the stomach. Hampering further study, as well, is the relative lack of cultured cell models that have tight junction claudins that are consistent with native tissues. This summary will review the current state of knowledge about gastric tight junctions, normally and in H. pylori infection, and make predictions about the consequences of claudin reorganization during H. pylori infection.     

Treatment of Helicobacter pylori infection:Current status and future concepts

Helicobacter pylori(H.pylori)infection is highly associated with the occurrence of gastrointestinal diseases,including gastric inflammation,peptic ulcer,gastric cancer,and gastric mucosa-associated lymphoid-tissue lymphoma.Although alternative therapies,including phytomedicines and probiotics,have been used to improve eradication,current treatment still relies on a combination of antimicrobial agents,such as amoxicillin,clarithromycin,metronidazole,and levofloxacin,and antisecretory agents,such as proton pump inhibitors(PPIs).A standard triple therapy consisting of a PPI and two antibiotics(clarithromycin and amoxicillin/metronidazole)is widely used as the first-line regimen for treatment of infection,but the increased resistance of H.pylori to clarithromycin and metronidazole has significantly reduced the eradication rate using this therapy and bismuth-containing therapy or 10-d sequential therapy has therefore been proposed to replace standard triple therapy.Alternatively,levofloxacin-based triple therapy can be used as rescue therapy for H.pylori infection after failure of first-line therapy.The increase in resistance to antibiotics,including levofloxacin,may limit the applicability of such regimens.However,since resistance of H.pylori to amoxicillin is generally low,an optimized high dose dual therapy consisting of a PPI and amoxicillin can be an effective first-line or rescue therapy.In addition,the concomitant use of alternative medicine has the potential to provide additive or synergistic effects against H.pylori infection,though its efficacy needs to be verified in clinical studies.     

Proteinase activated-receptors-associated signaling in the control of gastric cancer

Gastric cancer (GC) is the fourth most common cancer in the world and the second cause of cancer-related death. Gastric carcinogenesis is a multifactorial process, in which environmental and genetic factors interact to activate multiple intracellular signals thus leading to uncontrolled growth and survival of GC cells. One such a pathway is regulated by proteinase activated-receptors (PARs), seven transmembrane-spanning domain G protein-coupled receptors, which comprise four receptors (i.e., PAR-1, PAR-2, PAR-3, and PAR-4) activated by various proteases. Both PAR-1 and PAR-2 are over-expressed on GC cells and their activation triggers and/or amplifies intracellular pathways, which sustain gastric carcinogenesis. There is also evidence that expression of either PAR-1 or PAR-2 correlates with depth of wall invasion and metastatic dissemination and inversely with the overall survival of patients. Consistently, data emerging from experimental models of GC suggest that both these receptors can be important targets for therapeutic interventions in GC patients. In contrast, PAR-4 levels are down-regulated in GC and correlate inversely with the aggressiveness of GC, thus suggesting a negative role of this receptor in the control of GC. In this article we review the available data on the expression and role of PARs in GC and discuss whether manipulation of PAR-driven signals may be useful for interfering with GC cell behavior.     

A review of Helicobacter pylori diagnosis,treatment, and methods to detect eradication

Helicobacter pylori(H. pylori) affects nearly half of the world’s population and, thus, is one of the most frequent and persistent bacterial infections worldwide. H. pylori is associated with peptic ulcer disease, gastric ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Various diagnostic methods exist to detect infection, and the choice of one method or another depends on several factors, such as accessibility, advantages and disadvantages of each method, cost, and the age of patients. Once H. pylori infection is diagnosed, the clinician decides whether treatment is necessity, according to the patient’s clinical condition. Typically, eradication of H. pylori is recommended for treatment and prevention of the infection. Cure rates with the standard triple therapy are acceptable, and effective quadruple therapies, sequential therapies, and concomitant therapies have been introduced as key alternatives to treat H. pylori infection. In this work, we review the main diagnostic methods used to identify H. pylori infection and to confirm eradication of infection. In addition, key factors related to treatment are reviewed.     

Gastroretentive drug delivery systems for the treatment of Helicobacter pylori

Helicobacter pylori (H. pylori) is one of the most common pathogenic bacterial infections and is found in the stomachs of approximately half of the world’s population. It is the primary known cause of gastritis, gastroduodenal ulcer disease and gastric cancer. However, combined drug therapy as the general treatment in the clinic, the rise of antibiotic-resistant bacteria, adverse reactions and poor patient compliance are major obstacles to the eradication of H. pylori. Oral site-specific drug delivery systems that could increase the longevity of the treatment agent at the target site might improve the therapeutic effect and avoid side effects. Gastroretentive drug delivery systems potentially prolong the gastric retention time and controlled/sustained release of a drug, thereby increasing the concentration of the drug at the application site, potentially improving its bioavailability and reducing the necessary dosage. Recommended gastroretentive drug delivery systems for enhancing local drug delivery include floating systems, bioadhesive systems and expandable systems. In this review, we summarize the important physiological parameters of the gastrointestinal tract that affect the gastric residence time. We then focus on various aspects useful in the development of gastroretentive drug delivery systems, including current trends and the progress of novel forms, especially with respect to their application for the treatment of H. pylori infections.     

Efficacy of Helicobacter pylori eradication for the prevention of metachronous gastric cancer after endoscopic resection for early gastric cancer

Helicobacter pylori(H.pylori)plays an important role in gastric carcinogenesis,as the majority of gastric cancers develop from H.pylori-infected gastric mucosa.The rate of early gastric cancer diagnosis has increased in Japan and Korea,where H.pylori infection and gastric cancer are highly prevalent.Early intestinal-type gastric cancer without concomitant lymph node metastasis is usually treated by endoscopic resection.Secondary metachronous gastric cancers often develop because atrophic mucosa left untreated after endoscopic treatment confers a high risk of gastric cancer.The efficacy of H.pylori eradication for the prevention of metachronous gastric cancer remains controversial.However,in patients who undergo endoscopic resection of early gastric cancer,H.pylori eradication is recommended to suppress or delay metachronous gastric cancer.Careful and regularly scheduled endoscopy should be performed to detect minute metachronous gastric cancer after endoscopic resection.     

De-escalating therapy in gastric aggressive lymphoma

The treatment of primary gastric diffuse large B-cell lymphoma (DLBCL) has changed radically over the last 10–15 years, with the abandonment of routine gastrectomy in favor of more conservative therapies. Low-level evidence suggests that consolidation radiotherapy could be avoided in patients with limited-stage DLBCL of the stomach who achieve complete remission after rituximab-CHOP combination. Small, recent prospective trials suggest that selected patients with limited-stage Helicobacter pylori (H. pylori)-positive DLBCL of the stomach and favorable prognostic factors can be managed with antibiotics alone, with excellent disease control and cure rates, keeping chemo-radiotherapy for unresponsive patients. This recommendation should equally regard patients with mucosa-associated lymphoid tissue-related or de novo DLBCL. Future studies should be focused on the establishment of reliable variables able to distinguish the best candidates for exclusive treatment with H. pylori eradication from those who need for conventional chemo-immunotherapy.     

Gastric accommodation in non-ulcer dyspepsia and the roles of Helicobacter pylori infection and vagal function

Background—Thepathophysiological mechanisms in non-ulcer dyspepsia are incompletely understood.
Aims—To compare gastric motor andsensory functions in Helicobacter pyloripositive or negative patients with non-ulcer dyspepsia.
Patients—Seventeen patients withnon-ulcer dyspepsia and 16 asymptomatic controls.
Methods—The following wereevaluated: gastrointestinal symptoms; gastric emptying and orocaecaltransit of solids; abdominal vagal function; gastric compliance;fasting and postprandial gastric tone and phasic contractions; symptomsduring ingestion of cold water and during the distension of anintragastric bag; and somatic sensitivity and personality profile(Minnesota Multiphasic Personality Inventory, MMPI).
Results—Gastric accommodation wasreduced in H pylori negative dyspepticsrelative to controls; the degree of accommodation was unrelated toH pylori status in dyspeptics. Increasedpostprandial gastric sensation was more frequent amongH pylori positive patients (4/5H pylori positive versus 4/12H pylori negative patients). Intragastricmeal distribution and orocaecal transit were normal; gastric emptyingat four hours was abnormal in 4/17 patients. Vagal dysfunction wasrare. Eight of 17 patients had somatisation or depression on MMPI.
Conclusion—Impaired gastricaccommodation is frequent in non-ulcer dyspepsia and seems to beunrelated to vagal efferent dysfunction. Hpylori infection does not seem to influence gastric accommodation, but is associated with heightened sensitivity in dyspeptics. Therapeutic approaches that restore normal postprandial accommodation and gastric sensitivity should be tested in non-ulcer dyspepsia.

Keywords:non-ulcer dyspepsia; Helicobacter pylori; vagal function

     

Laryngopharyngeal reflux and Helicobacter pylori

Laryngopharyngeal reflux (LPR) occurs when gastric contents pass the upper esophageal sphincter, causing symptoms such as hoarseness, sore throat, coughing, excess throat mucus, and globus. The pattern of reflux is different in LPR and gastroesophageal reflux. LPR usually occurs during the daytime in the upright position whereas gastroesophageal reflux disease more often occurs in the supine position at night-time or during sleep. Ambulatory 24-h double pH-probe monitoring is the gold standard diagnostic tool for LPR. Acid suppression with proton pump inhibitor on a long-term basis is the mainstay of treatment. Helicobacter pylori (H. pylori) is found in many sites including laryngeal mucosa and interarytenoid region. In this paper, we aim to present the relationship between LPR and H. pylori and review the current literature.