Relapse rate of healed duodenal, prepyloric, and gastric ulcers treated either with sucralfate or cimetidine

Chemotherapy-induced gastrointestinal toxicity: Pathogenesis and current management

Chemotherapy is the most common treatment for malignant tumors. However, chemotherapy-induced gastrointestinal toxicity (CIGT) has been a major concern for cancer patients, which reduces their quality of life and leads to treatment intolerance and even cessation. Nevertheless, prevention and treatment for CIGT are challenging, due to the prevalence and complexity of the condition. Chemotherapeutic drugs directly damage gastrointestinal mucosa to induce CIGT, including nausea, vomiting, anorexia, gastrointestinal mucositis, and diarrhea, etc. The pathogenesis of CIGT involves multiple factors, such as gut microbiota disorders, inflammatory responses and abnormal neurotransmitter levels, that synergistically contribute to its occurrence and development. In particular, the dysbiosis of gut microbiota is usually linked to abnormal immune responses that increases inflammatory cytokines' expression, which is a common characteristic of many types of CIGT. Chemotherapy-induced intestinal neurotoxicity is also a vital concern in CIGT. Currently, modern medicine is the dominant treatment of CIGT, however, traditional Chinese medicine (TCM) has attracted interest as a complementary and alternative therapy that can greatly alleviate CIGT. Accordingly, this review aimed to comprehensively summarize the pathogenesis and current management of CIGT using PubMed and Google Scholar databases, and proposed that future research for CIGT should focus on the gut microbiota, intestinal neurotoxicity, and promising TCM therapies, which may help to develop more effective interventions and optimize managements of CIGT.

Smoking and the pathogenesis of gastroduodenal ulcer--recent mechanistic update

Peptic ulcer is a common disorder of gastrointestinal system and its pathogenesis is multifactorial, where smoking and nicotine have significant adverse effects. Smoking and chronic nicotine treatment stimulate basal acid output which is more pronounced in the smokers having duodenal ulcer. This increased gastric acid secretion is mediated through the stimulation of H2-receptor by histamine released after mast cell degranulation and due to the increase of the functional parietal cell volume or secretory capacity in smokers. Smoking and nicotine stimulate pepsinogen secretion also by increasing chief cell number or with an enhancement of their secretory capacity. Long-term nicotine treatment in rats also significantly decreases total mucus neck cell population and neck-cell mucus volume. Smoking also increases bile salt reflux rate and gastric bile salt concentration thereby increasing duodenogastric reflux that raises the risk of gastric ulcer in smokers. Smoking and nicotine not only induce ulceration, but they also potentiate ulceration caused by H. pylori, alcohol, nonsteroidal anti-inflammatory drugs or cold restrain stress. Polymorphonuclear neutrophils (PMN) play an important role in ulcerogenesis through oxidative damage of the mucosa by increasing the generation of reactive oxygen intermediates (ROI), which is potentiated by nicotine and smoking. Nicotine by a cAMP-protein kinase A signaling system elevates the endogenous vasopressin level, which plays an aggressive role in the development of gastroduodenal lesions. Smoking increases production of platelet activating factor (PAF) and endothelin, which are potent gastric ulcerogens. Cigarette smoking and nicotine reduce the level of circulating epidermal growth factor (EGF) and decrease the secretion of EGF from the salivary gland, which are necessary for gastric mucosal cell renewal. Nicotine also decreases prostaglandin generation in the gastric mucosa of smokers, thereby making the mucosa susceptible to ulceration. ROI generation and ROI-mediated gastric mucosal cell apoptosis are also considered to be important mechanism for aggravation of ulcer by cigarette smoke or nicotine. Both smoking and nicotine reduce angiogenesis in the gastric mucosa through inhibition of nitric oxide synthesis thereby arresting cell renewal process. Smoking or smoke extract impairs both spontaneous and drug-induced healing of ulcer. Smoke extract also inhibits gastric mucosal cell proliferation by reducing ornithine decarboxylase activity, which synthesises growth-promoting polyamines. It is concluded that gastric mucosal integrity is maintained by an interplay of some aggressive and defensive factors controlling apoptotic cell death and cell proliferation and smoking potentiates ulcer by disturbing this balance.

Is upper gastrointestinal radiography a cost-effective alternative to a Helicobacter pylori "test and treat" strategy for patients with suspected peptic ulcer disease?

OBJECTIVE

Current clinical consensus supports an initial Helicobacter pylori (HP) "test and treat" approach when compared to immediate endoscopy for patients with suspected peptic ulcer disease. Alternative diagnostic approaches that incorporate upper GI radiography (UGI) have not been previously evaluated. We sought to determine the cost effectiveness of UGI compared to a HP test and treat strategy, incorporating recent data addressing the reduced prevalence of HP, lower cost of diagnostic interventions, and reduced attribution of PUD to HP.

METHODS

Using decision analysis, three diagnostic and treatment strategies were evaluated: 1) Test and Treat--initial HP serology, treat patients who test positive with HP eradication and antiulcer therapy; 2) Initial UGI series--treat all patients with documented ulcer disease with HP eradication and antiulcer therapy; and 3) Initial UGI series, HP serology if ulcer present--treat ulcer and HP based on diagnostic test results.

RESULTS

The estimated cost per ulcer cured for each strategy were as follows: test and treat, $3,025; initial UGI, $3,690; and UGI with serology, $3,790. The estimated cost per patient treatment were: test and treat, $498; initial UGI, $610; and UGI with serology, $620. When UGI reimbursement was decreased to less than $50, the UGI strategies yielded a lower cost per patient treated than the test and treat strategy.

CONCLUSION

At the current level of reimbursement, UGI should not be considered a cost-effective alternative to the HP test and treat strategy for the initial evaluation of patients with suspected peptic ulcer disease.

Clinical efficacy of sucralfate in the treatment of gastric ulcer

We performed a randomized, single-blind study in Japan to investigate the efficacy and safety of two dosage regimens of sucralfate granules, 2 g, twice daily (b.i.d. group, n = 30) and 1 g, 4 times daily (q.i.d. group, n = 27), on ulcer healing in 57 patients with endoscopically proven gastric ulcer. Endoscopy was performed after 4 weeks and, if complete healing was not achieved, again after an additional 4 weeks. Of 57 patients, 11 were excluded from the statistical analysis because of protocol violation (six in b.i.d. group, five in q.i.d. group). Of 46 patients eligible for the analysis of healing rates, four patients in the b.i.d. group (all at 8 weeks) and five patients in the q.i.d. group (two at 4 weeks and three at 8 weeks) were withdrawn due to patients' inconvenience. As the possibility that the withdrawals were due to the treatment failures could not be denied, we used the Kaplan-Meier method and generalized Wilcoxon test/logrank test for the calculation and evaluation of healing rates in this study, respectively. Healing rates at 4 and 8 weeks were 50% and 94% in the b.i.d. group and 35% and 68% in the q.i.d. group. There was no significant difference in healing rates between the groups. No serious adverse effect was observed in either group. These results suggest that the 2 g b.i.d. dose of sucralfate in granule form is at least as effective as the conventional dose of 1 g q.i.d. in the treatment of active gastric ulcers and could lead to better patient compliance.