The diurnal profile of gastric pepsin activity is reduced with Helicobacter pylori infection

Patients with gastroesophageal reflux disease (both reflux oesophagitis and non-erosive reflux disease): Prevalence and severity of erosive tooth wear and saliva properties

BACKGROUND

The prevalence between erosive tooth wear (ETW) in association with reflux oesophagitis (RO) has been reported. However, the severity of both diseases and the relationship between ETW and non-erosive reflux disease (NERD) is unclear.

OBJECTIVES

The prevalence and severity of ETW were investigated in RO, NERD and healthy controls.

METHODS

135 patients with RO, 65 with NERD and 40 healthy controls were recruited for this case-control study. A modified tooth wear index was used to evaluate the prevalence and severity of ETW. Salivary secretion and buffer capacity were assessed prior to endoscopy. The prevalence and severity of ETW, saliva properties among each group were analysed using Pearson's chi-squared test.

RESULTS

A total of 135 cases (56.3%) were categorised as the patient with ETW (55 with mild RO, 49 with severe RO and 31 with NERD). There was a significant relationship between the prevalence of RO and ETW, while there was no significant correlation between the prevalence of NERD and ETW. There was a significant difference related to the severity between RO and ETW. For salivary secretion, there was a significant difference between with and without ETW in patients with mild RO, severe RO and NERD. There was a significant difference between with and without ETW for salivary buffer capacity in patients with mild and severe RO.

CONCLUSION

There was a significant association of the prevalence and severity between RO and ETW. Clinical signs such as ETW and salivary buffer capacity depended on the severity of RO.

Influence of the digestive enzymes trypsin and pepsin in vitro on the progression of erosion in dentine

OBJECTIVES

In patients with eating disorders, gastric and pancreatic enzymes could possibly reach the oral cavity during vomiting and could perhaps degrade the organic matrix of eroded dentine. This in vitro study sought to investigate whether pepsin, trypsin or the combination of both, have an influence on erosive mineral loss in dentine and whether they are able to degrade the organic matrix.

METHODS

Sixty-four human dentine specimens were prepared and randomly divided into four groups. Specimens were cyclically de- and remineralised for six days. Demineralisation was performed with an HCl-solution (6x 5min daily, pH 1.6) in groups 1 and 3; in groups 2 and 4 the demineralisation solution additionally contained pepsin (750 microg/ml). After demineralisation, specimens of groups 3 and 4 were treated with a trypsin solution (6x 10min daily, 2000 BAEE/ml). After each day, mineral content (mum) was determined microradiographically, and the matrix degradation was determined by hydroxyproline analysis.

RESULTS

After six days, treatment with pepsin (group 2) or trypsin (group 3) had no significant influence on mineral loss. The combined impact of pepsin and trypsin led to significantly higher mineral loss (group 4: 202.5+/-37.4) compared to all other groups (group 1: 139.1+/-29.5, p<or=0.001; group 2: 108.8+/-34.7, p<or=0.001; group 3: 157.8+/-37.2, p<or=0.05). Hydroxyproline was found in all pepsin-solutions but in no trypsin- or HCl-solutions.

CONCLUSION

The combined impact of pepsin and trypsin intensified dentine erosion progression in vitro. This could be one reason for the fast proceeding of dental erosion in patients with chronic vomiting.

Effect of pepsin on erosive tissue loss and the efficacy of fluoridation measures in dentine in vitro

OBJECTIVES

In dentine, erosive lesion progression and efficacy of fluoridation measures for symptomatic therapy of dental erosion are both dependent on the presence of the organic matrix. In patients with eating disorders in combination with chronic vomiting, the demineralized organic matrix can be degraded by gastric enzymes. The aim of this study was to investigate the effect of pepsin on erosion progression and the efficacy of fluoride in dentine.

MATERIAL AND METHODS

Human dentine specimens were prepared and randomly divided into 4 groups of 20 specimens each. They were subjected to a cyclic de- and remineralization procedure for 9 days. For demineralization (6 x 2 min per day), an HCl solution (pH 1.6) was used in all groups. In two groups, pepsin (1.5 mg mL(-1)) was added to the demineralization solution. Fluoridation was performed in two groups 6 x 1 min per day with a mouth rinse (Olaflur/SnF(2); 250 ppm F(-)) after demineralization with both the HCl solution and the pepsin containing solution. Degradation of collagen was quantified by analyzing hydroxyproline and tissue loss was determined microradiographically. SEM images were taken in addition.

RESULTS

In the pepsin group, 1.72 (0.26) microg mL(-1) (mean (SD)) hydroxyproline per day was detected, and in the pepsin-fluoride group 1.95 (0.50) microg mL(-1). Tissue loss after 9 days in the control group was similar to that in the pepsin group (122.2 (53.4) microm and 122.2 (38.0) microm, n.s., respectively). Fluoridation reduced tissue loss after demineralization (98.8 (30.2) microm) but not after pepsin treatment (125.2 (34.2) microm; p< or =0.05).

CONCLUSION

Under the conditions used, pepsin had no influence on tissue loss, but altered the efficacy of fluoridation measures.

Gastric secretion

PURPOSE OF REVIEW

The purpose of this review is to summarize the pertinent literature published in the past year regarding the regulation of gastric exocrine and endocrine secretion.

RECENT FINDINGS

Gastric acid aids protein digestion; facilitates the absorption of iron, calcium, and vitamin B12; thwarts enteric infection; and prevents bacterial overgrowth. When levels of acid and proteolytic enzymes overwhelm the mucosal defense mechanisms, ulcers occur. To avoid damage under these harsh conditions, gastric acid must be finely regulated by overlapping neural (e.g. orexin, pituitary adenylate cyclase-activating polypeptide, nitric oxide, and galanin), hormonal (e.g. gastrin, cholecystokinin, and ghrelin), paracrine (e.g. histamine and somatostatin), and autocrine (e.g. transforming growth factor-alpha) pathways. The precise mechanisms whereby Helicobacter pylori induces perturbations in acid secretion are not known, but they seem to involve changes in somatostatin and perhaps ghrelin secretion. Acid secretion by parietal cells involves intracellular elevation of calcium and/or cyclic AMP, followed by a cascade that triggers translocation of the proton pump, HK-adenosine triphosphatase, from cytoplasmic tubulovesicles to the secretory canaliculi.

SUMMARY

An improved understanding of the pathways and mechanisms regulating gastric acid secretion may lead to the development of new strategies to prevent and treat acid peptic disorders as well as circumvent the adverse effects of currently prescribed antisecretory medications.