Interplay of potassium channel, gastric parietal cell and proton pump in gastrointestinal physiology, pathology and pharmacology

Gastric acid secretion plays a pivotal role in the physiology of gastrointestinal tract. The functioning of the system encompasses a P2 ATPase pump (which shuttles electroneutral function at low pH) along with different voltage sensitive/neutral ion channels, cytosolic proteins, acid sensor receptors as well hormonal regulators. The increased acid secretion is a pathological marker of several diseases like peptic ulcer, gastroesophageal reflux disease (GERD), chronic gastritis, and the bug Helicobacter pylori (H. pylori) has also a critical role, which altogether affects the patient's quality of life. This review comprehensively describes about the nature of potassium ion channel and its mediators, the different clinical strategy to control acid rebound, and some basic experimental observations performed to study the interplay of ion channels, pumps, as well as mediators during acid secretion. Different aspects of regulation of gastric acid secretion have been focused either in terms of physiology of secretion or molecular interactions. The importance of H pylori infection and its treatment have also been discussed. Furthermore, the relevance of calcium signaling during acid secretion has been reviewed. The entire theme will make anyone to understand in details about the gastric secretion machinery in general.

[Helicobacter pylori eradication with a clarithromycin-based triple therapy in elderly patients: a case-control study]

BACKGROUND

Helicobacter pylori (H. pylori), main agents of several gastroduodenal diseases, represents a therapeutic challenge. Since the influence of age on the success of bacterial treatment remains uncertain, in this case-control study we assessed the efficacy of a standard H. pylori eradication therapy among elderly patients.

METHODS

In this retrospective study, a total of 361 naïve patients (194 males, mean age 79.8± 3.4 years) aged more than 65 years and treated with a triple therapy regimen comprising a standard dose of omeprazole twice daily, amoxicillin 1g twice daily and clarithromycin 500 mg twice daily, for 7, 10 or 14 days, were included. They were compared with naïve patients, younger than 65 years (mean age 43± 2.7 years). Since in the year 2017, we began to use the three-in-one single capsule bismuth-containing quadruple therapy, the search was ended at 31 December 2016.

RESULTS

Overall, H. pylori eradication rate in the intention-to-treat (ITT) analysis, was 70.9% (256/361) among elderly patients versus 70.9% (256/361) among young patients. Dividing by treatment duration, among elderly patients, eradication was obtained in 78.1% (50/64), 69.1% (139/201) and 69.7% (67/96) elderly patients within 7-day, 10-day and 14-day regimens, respectively, without statistical difference. Out of 361 elderly patients, 11 were excluded from the per protocol (PP) analysis because of discontinuations (7 for adverse events). One subject discontinued treatment among young patients. Also the PP analysis showed no statistical difference, with an eradication rate of 73.1% (256/350) among elderly patients versus 71.1% (256/360) among young patients.

CONCLUSIONS

Elderly does not affect efficacy or safety of a clarithromycin-based triple therapy for H. pylori eradication.

Management of Dyspepsia and Gastroparesis in Patients with Diabetes. A Clinical Point of View in the Year 2021

Diabetes mellitus is a widespread disease, and represents an important public health burden worldwide. Together with cardiovascular, renal and neurological complications, many patients with diabetes present with gastrointestinal symptoms, which configure the so-called diabetic enteropathy. In this review, we will focus on upper gastrointestinal symptoms in patients with diabetes, with particular attention to dyspepsia and diabetic gastroparesis (DG). These two clinical entities share similar pathogenetic mechanisms, which include autonomic neuropathy, alterations in enteric nervous system and histological abnormalities, such as interstitial cells of Cajal depletion. Moreover, the differential diagnosis may be challenging because of overlapping clinical features. Delayed gastric emptying should be documented to differentiate between DG and dyspepsia and it can be assessed through radioactive or non-radioactive methods. The clinical management of dyspepsia includes a wide range of different approaches, above all Helicobacter pylori test and treat. As regards DG treatment, a central role is played by dietary modification and glucose control and the first-line pharmacological therapy is represented by the use of prokinetics. A minority of patients with DG refractory to medical treatment may require more invasive therapeutic approaches, including supplemental nutrition, gastric electric stimulation, pyloromyotomy and gastrectomy.

Management of functional dyspepsia in 2020: a clinical point of view

Dyspepsia is a disorder that refers mainly to central upper abdominal pain or discomfort. When a cause of this symptom is not identified the condition is termed functional dyspepsia (FD), that affects a large part of the general population. The relevance of FD is due to its high prevalence, but also to its chronic or intermittent course. This induces a significant burden for each national healthcare system. The pathogenesis of FD is complex and multifactorial, depending on cultural, environmental, and biological factors. Although considered of main importance in the pathophysiology of several gastroduodenal diseases, in the context of FD Helicobacter pylori (H. pylori) infection plays a limited role. The diagnosis of FD requires the exclusion of organic gastroduodenal diseases as well as H. pylori infection. Thus, the diagnostic workup includes a complete anamnesis, biochemical tests, and endoscopy with biopsy (when requested), and the satisfaction of clinic criteria recommended by the Rome IV consensus. The treatment of FD is also challenging, in fact more and more studies focused on a wide range of different therapies, with a multitude of results. The aim of this literature review is to provide an update of the new evidences useful for diagnosis and management of FD.