Influence of smoking on basal and on vagally and maximally stimulated gastric acid and pepsin secretion

The impact of secondhand smoke on failure of Helicobacter pylori therapy is not inferior to that of smoking

BACKGROUND

Previous studies have shown the associations between smoking and failure to eradicate Helicobacter pylori (H. pylori), but less is known about the impact of secondhand tobacco smoke (SHS) on H. pylori eradication.

METHODS

Between July 2022 to July 2023, 646 patients who received proton pump inhibitor (PPIs) as first-line H. pylori eradication therapy were recruited for the study. Information was obtained via the hospital database and a telephone questionnaire. Univariate and multivariate regression analysis were used to examine risk factors of H. pylori eradication failure.

RESULTS

This was a single-center retrospective study consisting of 646 patients who received PPIs as first-line H. pylori eradication therapy. This included 122 smokers, 165 never-smokers with SHS, and 359 never-smokers with no SHS exposure. Compared with subjects in the "eradication success" group, those in the "eradication failure" group tended to have higher prevalence of smoke consumption and have higher prevalence of SHS exposure. In binary logistic regression analysis, smoking (OR 3.409, 95 % CI: 1.782- 6.522, P < 0.001) and SHS (OR 3.188, 95 % CI: 1.726-5.886, P < 0.001) were independent predictors of eradication failure. In addition, never-smokers with SHS exposure and smoking had similar effects on H. pylori eradication (OR, 0.893; 95 % CI, 0.464 to 1.717, P value = 0.734).

CONCLUSION

Both smoking and SHS are independent risk factors for H. pylori eradication failure. Furthermore, the impact of SHS is not inferior to smoking.

Floating Drug Delivery Systems: An Emerging Trend for the Treatment of Peptic Ulcer

Floating drug delivery system (FDDS) is the main approach to prolonging the gastric residence time in the stomach in which the bilayer floating tablet has the main role. It is more suitable for the treatment of local infections such as peptic ulcer, gastritis, Zollinger-Ellision syndrome, indigestion, and other local infections related to the gastrointestinal tract and also used for systemic applications. FDDS provides protection for those drugs which are acid labile and have a short half-life. It also improves bioavailability, reduces drug waste, and enhances the residence time of drugs. Nowadays, various technologies are being used for the development of FDDS. Novel drug delivery systems incorporation into bilayer floating tablets have also broadened the role of FDDS. Polymers have the main role in the development of FDDS, which serve as carriers for the drug and determine the gastric retention time and drug protection. FDDS is also an easy, cheap, and more convenient method for dual drug delivery of drugs.

Efficacy of modified esomeprazole-amoxicillin dual therapies for Helicobacter pylori infection: an open-label, randomized trial

OBJECTIVE

The prevalence of Helicobacter pylori resistance to amoxicillin was less than 5% in most countries. Proton pump inhibitor (PPI)-amoxicillin dual therapy dosing four times daily (q.i.d.) for 14 days could achieve an eradication rate of more than 85%. It is unclear whether dual therapy with shorter treatment duration or lower dosing frequency could also attain a satisfactory cure rate. We conducted a randomized controlled trial to assess the efficacy and safety of two modified esomeprazole-amoxicillin dual therapies, 10-day q.i.d. and 14-day three times daily (t.i.d.) dual therapy, and investigate the factors that might affect the eradication rates.

PARTICIPANTS AND METHODS

A total of 253 patients were screened for eligibility and 208 patients were randomly assigned to 10-day dual therapy (esomeprazole 20 mg and amoxicillin 750 mg, all given four times daily) or 14-day dual therapy (esomeprazole 20 mg and amoxicillin 1000 mg, all given three times daily).

RESULTS

In the intention-to-treat analysis, the eradication rates for 10-day and 14-day groups were 79.8% [95% confidence interval (CI): 70.2-87.4%] and 83.5% (95% CI: 74.3-90.5%) as first-line therapies; and 80% (95% CI: 44.4-97.5%) and 76.9% (95% CI: 46.2-95.0%) as rescue therapies. The adverse event rates were 5.9% and 5.0% for 10-day and 14-day groups, respectively. Smoking and compliance significantly affected the efficacy of PPI-amoxicillin dual therapies.

CONCLUSION

The eradication rate of 10-day q.i.d. dual therapy was unacceptable, while that of the 14-day t.i.d. dual therapy was borderline acceptable for first-line therapy. The two dual therapies were well tolerated with few adverse effects.

High-dose PPI-amoxicillin dual therapy with or without bismuth for first-line Helicobacter pylori therapy: A randomized trial

BACKGROUND

A reliably highly effective high-dose proton-pump inhibitor plus amoxicillin (dual Helicobacter pylori therapy) has remained elusive. We compared whether the addition of bismuth to high-dose dual therapy would improve the efficacy of high-dose dual therapy as first-line treatment.

METHODS

This was an open-label, randomized single-center study of 160 treatment-naive patients with H. pylori infection who were randomly assigned to 14-day therapy with esomeprazole 40 mg twice a day plus amoxicillin 1 g three times a day with or without bismuth potassium citrate 600 mg (elemental bismuth 220 mg) twice a day. Antibiotic resistance was determined by agar dilution method and eradication by ¹³ C-urea breath test.

RESULTS

The per-protocol eradication rates were 96.1%; 95% CI = 88.9%-99.2% (73/76) without bismuth vs 93.3%; 95% CI = 85.1%-97.8% (70/75) with bismuth (P = 0.494). The intention-to-treat eradication rates were 92.5%; 95% CI = 84.4%-97.2% (74/80) without bismuth and 88.8%; 95% CI = 79.7%-94.7% (71/80) with bismuth (P = 0.416). Resistance to amoxicillin, clarithromycin, metronidazole, and levofloxacin was 0%, 31.7%, 81.4%, and 40.7%, respectively. Smoking reduced treatment effectiveness limited to those not receiving bismuth. The per-protocol eradication rates were 70% (7/10) vs 100% (66/66) in smokers vs non-smokers without bismuth (P = 0.002), and 100% (10/10) in smokers vs 92.3% (60/65) in non-smokers with bismuth (P = 1.0). The adverse event rates were 7.5% (6/80) without bismuth vs 11.3% (9/80) with bismuth (P = 0.416).

CONCLUSIONS

Fourteen-day high-dose dual therapy was both effective and safe for first-line treatment in a region of high prevalence antibiotic resistance. Adding bismuth only improved treatment effectiveness among smokers.

Comparative study: Vonoprazan and proton pump inhibitors in Helicobacter pylori eradication therapy

AIM

To compare the effectiveness and safety of vonoprazan-based therapy with proton pump inhibitor (PPI)-based therapies to treat Helicobacter pylori (H. pylori).

METHODS

We retrospectively analysed data from first-line (vonoprazan or PPI with 200 mg clarithromycin and 750 mg amoxicillin twice daily for 7 d) (n = 1353) and second-line (vonoprazan or PPI with 250 mg metronidazole and 750 mg amoxicillin twice daily for 7 d) (n = 261) eradication treatments for H. pylori -positive patients with associated gastrointestinal diseases from April 2014 to December 2015 at Hattori Clinic, Japan. The primary endpoint was the eradication rate, which was assessed with a full analysis set. The secondary endpoints were adverse events and related factors.

RESULTS

After the first-line treatments, the eradication rates for vonoprazan, esomeprazol, rabeprazole, and lansoprazole were 87.9% (95%CI: 84.9%-90.5%), 71.6% (95%CI: 67.5%-75.5%), 62.9% (95%CI: 52.0%-72.9%), and 57.3% (95%CI: 50.4%-64.1%), respectively. The vonoprazan eradication rate was significantly higher than that of the PPIs (P < 0.01). Interestingly, smoking did not affect the H. pylori eradication rate in the vonoprazan group (P = 0.34), whereas it decreased the rates in the PPI groups (P = 0.013). The incidence of adverse events in the vonoprazan group was not different from the PPI group (P = 0.054), although the vonoprazan group exhibited a wider range of adverse events. Vonoprazan-based triple therapy was highly effective as a second-line treatment, with an eradication rate similar to that of PPI-based therapy.

CONCLUSION

Vonoprazan might be superior to PPIs in first-line H. pylori therapy, particularly for smokers. However, caution is required due to possible adverse events.

Gastric Mixing During Food Digestion: Mechanisms and Applications

Gastric mixing is a complex process that is governed by meal properties, such as food buffering capacity, physical properties, and the rate of breakdown as well as physiological factors, such as the rate of gastric secretions, gastric emptying, and gastric motility. Gastric mixing processes have been studied through the use of experimental and computational methods. Gastric mixing impacts the intragastric pH distribution and residence time in the stomach for ingested materials. Development of a fundamental understanding of the advective and diffusion processes and their roles in gastric mixing will be important in furthering our understanding of food breakdown, microbial survival, and drug dissolution during gastric digestion.

A prospective study of Helicobacter pylori in relation to the risk for pancreatic cancer

BACKGROUND

The relationship between Helicobacter pylori infection and pancreatic cancer has been investigated in three previous studies with contradictory results. The aim of the present study was to investigate the association between H. pylori seropositivity and the risk for pancreatic cancer in a nested case-control study within a population based cohort.

METHODS

Selected birth-year cohorts (born 1921-1949) of residents in Malmö, Sweden, were invited to a health screening investigation. A total of 33 346 subjects participated. Cases with pancreatic cancer (n = 87) were matched to controls (n = 263) using age, sex and time for baseline investigation as matching variables. H. pylori serology was analysed in stored serum samples using an enzyme-linked immunosorbent assay. Odds ratios (OR) for pancreatic cancer were calculated with 95% confidence intervals (CI) using logistic regression.

RESULTS

H. pylori seropositivity was not associated with pancreatic cancer in the total cohort (adjusted OR 1.25 (0.75-2.09)). However, a statistically significant association was found in never smokers (OR 3.81 (1.06-13.63) adjusted for alcohol consumption) and a borderline statistically significant association was found in subjects with low alcohol consumption (OR 2.13 (0.97-4.69) adjusted for smoking).

CONCLUSION

We conclude that no association between H. pylori infection and the risk for pancreatic cancer was found in the total cohort. However, in never smokers and in subjects with low risk alcohol consumption, a positive H. pylori serology was associated with an increased risk for pancreatic cancer. These findings should be interpreted cautiously due to the limited number of cases in these subgroups.

Gastric histology, serological markers and age as predictors of gastric acid secretion in patients infected with Helicobacter pylori

BACKGROUND

Acid secretion is intimately associated with most upper gastrointestinal diseases. Helicobacter pylori infection is a major environmental factor modifying acid secretion.

AIM

To study the association between the pattern of H pylori gastritis and gastric secretory function in a large number of subjects without specific upper gastrointestinal disease.

METHODS AND MATERIALS

Maximal acid output (MAO) was measured in 255 patients with dyspepsia showing normal endoscopy. Activity and severity of gastritis, atrophy and H pylori infection were assessed in body and antral biopsies. The correlations of histological parameters as well as age, sex, height, weight, smoking, serum gastrin, pepsinogen I and II, and their ratio with MAO were determined. Multiple linear regression was used to show the best possible predictors of MAO.

RESULTS

Negative relationships: Body atrophy and body-combined (active and chronic) inflammatory scores showed a potent inverse correlation with MAO (correlation coefficients (CC) 0.59 and 0.50, respectively). Body:antral chronic gastritis ratio and body:antral combined inflammation ratio (both with CC = 0.49) and age (CC = 0.44) were also inversely correlated with MAO. Intestinal metaplasia at both antral and body sites had negative relationships with acid output with CC = 0.23 and 0.20, respectively. Positive relationships: Serum pepsinogen I, body H pylori density:combined inflammation ratio and pepsinogen I:II ratio with CC of 0.38, 0.38 and 0.30, respectively, correlated with MAO. The H pylori density: combined inflammation of both antrum and body positively correlated with MAO (CC = 0.29 and 0.38, respectively). Male sex and patient height also positively correlated with acid output. Modelling showed that body combined inflammatory score, body atrophy, age and serum pepsinogen I are independent predictors of acid output (R(2) = 0.62).

CONCLUSION

Combination of body gastritis, body atrophy, age and serum pepsinogen I can be used as predictors of acid-secretory state in populations infected with H pylori.

Effect of exogenous administration of transforming growth factor-beta and famotidine on the healing of duodenal ulcer under the impact of indomethacin

BACKGROUND

Non-steroidal anti-inflammatory drugs delay ulcer healing and cause refractory peptic ulcers in humans.

OBJECTIVE

To study the effects of growth factors on experimental duodenal ulcer healing in indomethacin-treated rats.

METHODS

Duodenal ulcers were induced in male Wistar rats by the serosal application of 75% acetic acid for 10 s. Rats were then treated with indomethacin (2 mg/kg/day; s.c.), transforming growth factor beta (15 ng locally injected subserosally at the ulcer site) or famotidine (5 mg/kg/day; p.o.), vehicle or combinations of treatments. On day 5, 8 or 12, rats were sacrificed and the ulcer area planimetrically measured under a dissecting microscope. Macroscopic area, microscopic diameter, collagen content and mucosal regeneration were assessed in histological preparations. Gastric secretion was assessed also in the pylorus-ligated rat-model. Data expressed as median and ranges were analyzed by non-parametric test.

RESULTS

Indomethacin delayed ulcer healing but transforming growth factor-beta and famotidine improved ulcer healing and reversed the effects of indomethacin. Maximal differences were observed on day 8. Transforming growth factor-beta was associated with an increase in epithelial and granulation tissue cell proliferation. Famotidine induced a profound inhibition of gastric secretion and increased collagen secretion but it did not affect cell proliferation.

CONCLUSIONS

Transforming growth factor-beta and famotidine accelerate ulcer healing delayed by indomethacin.

Cigarette smoking, use of other tobacco products and stomach cancer mortality in US adults: The Cancer Prevention Study II

Cigarette smoking is associated with increased risk of stomach cancer in many studies but there are limited data on this relationship in women and on risk associated with use of tobacco products other than cigarettes. We examined stomach cancer death rates in relation to cigarette smoking in women and use of cigarette, cigar, pipe, or smokeless tobacco in men in a nationwide prospective mortality study in the United States (US). Cohort follow-up from 1982-96 identified 996 and 509 stomach cancer deaths among 467,788 men and 588,053 women, respectively. Cox proportional hazards models were fitted to estimate rate ratios (RR) and 95% confidence intervals (CI) using non-users of tobacco as the referent group. Multivariate-adjusted RRs were the highest for men who currently smoked cigars (RR = 2.29, 95% CI = 1.49-3.51) or cigarettes (RR = 2.16, 95% CI = 1.75-2.67) and both increased with smoking duration. Women who currently (RR = 1.49, 95% CI = 1.18-1.88) or formerly (RR = 1.36, 95% CI = 1.08-1.71) smoked cigarettes were at significantly increased risk, as were men who formerly smoked cigarettes (RR = 1.55, 95% CI = 1.28-1.88), or currently (RR = 1.81, 95% CI = 1.40-2.35) or formerly (RR: 1.57, 95% CI = 1.22-2.03) used more than one type of tobacco. Men who reported a history of chronic indigestion or gastroduodenal ulcer had substantially higher mortality rates associated with current cigarette (RR = 3.45, 95% CI = 2.05-5.80) or cigar (RR = 8.93, 95% CI = 4.02-19.90) smoking, as did men who were current aspirin users. If causal, the estimated proportion of stomach cancer deaths attributable to tobacco use would be 28% in US men and 14% in women. We conclude that prolonged use of tobacco products is associated with increased stomach cancer mortality in men and women. The accumulated evidence from this and other studies support reconsidering stomach cancer as a tobacco-related cancer.

[Effect of exogenous administration of platelet-derived growth factor and epidermal growth factor on duodenal ulcer healing in rats treated with indomethacin]

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) delay peptic ulcer healing through mechanisms that are still not entirely understood. Growth factors play a significant role in healing.

AIM

To evaluate whether exogenous administration of platelet-derived growth factor (PDGF) reverses the effect of indomethacin in experimental duodenal ulcers in rats and to define the potential mechanisms involved in this process.

METHOD

Duodenal ulcer was induced in male Wistar rats with acetic acid. The rats were then administered indomethacin (2 mg/kg/day), PDGF-BB (30 ng/100 g/day), epidermal growth factor (EGF) (50 /kg/day) or famotidine (positive control) or the possible combinations of these. Macroscopic area, reduction in microscopic diameter, epithelial and granulation tissue proliferation, collagen secretion by granulation tissue, and gastric acid secretion were analyzed.

RESULTS

Indomethacin delayed duodenal ulcer healing by decreasing cellular proliferation and inhibiting collagen secretion. PDGF and EGF accelerated healing and reversed the effects of indomethacin. The mechanisms involved were associated with an increase in collagen proliferation and secretion without affecting gastric acid secretion. Famotidine also accelerated healing and reversed the effect of indomethacin, and these effects were associated with a marked inhibition of gastric acid secretion and increase in collagen secretion by granulation tissue.

CONCLUSIONS

Exogenous administration of PDGF and EGF accelerated healing and reversed the harmful effects of indomethacin in an experimental model of duodenal ulcer.

Cetraxate, a mucosal protective agent, combined with omeprazole, amoxycillin, and clarithromycin increases the eradication rate of helicobacter pylori in smokers

BACKGROUND

Our previous study demonstrated that Helicobacter pylori eradication was less effective in smokers than in non-smokers. Cetraxate is an anti-ulcer drug that increases gastric mucosal blood flow.

AIM

To evaluate the effect of cetraxate combined with new triple therapy for the eradication of H. pylori in smokers.

METHODS

This study had a single-centre, double-blind, randomized non-placebo design. A total of 106 consecutive H. pylori-positive smoking patients were randomly allocated to one of two regimens: one group received omeprazole (20 mg), amoxycillin (1500 mg), and clarithromycin (600 mg) for 7 days (OAC, n=55). The other group recieved OAC plus cetraxate (600 mg) for 7 days (OAC + CET, n=51). The success of H. pylori eradication was evaluated by histology and the 13C-urea breath test at 4 weeks after completion of treatment.

RESULTS

By intention-to-treat analysis, the H. pylori eradication rate was 55% in the OAC group and 92% in the OAC + CET group (P<0.01). By per protocol analysis, the H. pylori eradication rate was 58% in the OAC group and 94% in the OAC + CET group (P<0.01).

CONCLUSION

Cetraxate combined with new triple therapy increases the eradication of H. pylori in smokers.

Relationship between Helicobacter pylori infection and smoking and drinking habits

BACKGROUND

Helicobacter pylori is a major cause of various gastroduodenal diseases. Some risk factors related to H. pylori infection have been reported; however, studies on the relationship between H. pylori infection and smoking or drinking habits have given conflicting results. In the present study, these relationships were investigated by collecting sera and information from 8837 subjects.

METHODS

Serum H. pylori immunoglobulin G antibody was measured by an enzyme-linked immunoassay. In addition to sex and age, information on smoking and drinking habits was collected by questionnaire. Age- and sex-adjusted odds ratios (95% confidence interval) of smoking and alcohol consumption were calculated for H. pylori seropositivity using logistic regression models.

RESULTS

Current smokers had a 0.82 (0.74-0.91)-fold greater risk of H. pylori seropositivity than those who had never smoked. Current cigarette consumption showed a dose-dependently negative association with H. pylori seropositivity, and the association between smoking and H. pylori infection was strong in younger subjects. Current drinkers had a 0.88 (0.79-0.98)-fold greater risk of H. pylori seropositivity than those who had never drunk alcohol. The volume of alcohol consumed showed a negative association with H. pylori seropositivity.

CONCLUSIONS

In the current study, smoking was negatively associated with H. pylori infection. The risk of H. pylori seropositivity decreased linearly with cigarette consumption per day. Increased gastric acidity in the stomach through smoking may be a cause of the dose-dependently negative association between H. pylori and smoking. Drinking was negatively and dose-dependently associated with H. pylori positivity, although the effect of drinking was weaker than that of smoking.

Comparison of meal-stimulated serum gastrin response in Helicobacter pylori-positive duodenal ulcer and asymptomatic volunteers with and without H. pylori infection

BACKGROUND

Duodenal ulcer (DU) patients exhibit raised postprandial gastrin release as compared to that in healthy controls. It is believed that serum pepsinogen I (PG I) concentration reflects the chief cell mass and that hyperpepsinogenemia I plays an important role in the pathogenesis of DU. Currently, strong evidence suggests that Helicobacter pylori (H. pylori) infection plays an important role in the pathogenesis of DU.

MATERIALS AND METHODS

Subjects consisted of 15 patients with H. pylori-positive DU, 10 H. pylori-positive volunteers, and 35 H. pylori-negative volunteers. Blood samples were taken before and at 15, 30, and 60 minutes after eating the test meal, which consisted of 100 gm rice, 130 gm chicken, and 1 egg. The 1-hour integrated gastrin response (IGR) was taken as the area under the serum gastrin time curve, calculated by the trapezoid method. Serum gastrin (SG) and fasting serum PG I concentrations were measured by radioimmunoassay.

RESULTS

Meal-stimulated SG response and fasting PG I concentration were significantly higher in DU patients than in H. pylori-positive and -negative volunteers. The DU patients were divided into two groups in accordance with their IGR levels as follows: hyper-IGR and normo-IGR. Serum PG I concentration was significantly higher in the hyper-IGR than in the normo-IGR group.

CONCLUSIONS

The DU patients differed in some way (other than H. pylori infection) from the H. pylori-positive healthy volunteers. The fact that hyper-IGR DU patients had higher serum PG I concentrations suggests that patients in this group may be acid hypersecretors.

Effect of smoking and histological gastritis severity on the rate of H. pylori eradication with omeprazole, amoxicillin, and clarithromycin

BACKGROUND

The combination of omeprazole, amoxicillin, and clarithromycin is a common regimen against Helicobacter pylori. Several recent studies have shown that smoking, high intragastric acidity, and the degree of histological gastritis are associated with H. pylori eradication failure.

MATERIALS AND METHODS

One hundred and thirty-seven H. pylori-positive patients were treated with a 1-week regimen composed of omeprazole, 20 mg once daily; amoxicillin, 500 mg; and clarithromycin, 200 mg thrice daily. Success of the treatment was evaluated by histology and the 13C-urea breath test at least 4 weeks after completion of therapy. Data about age, gender, alcohol intake, smoking habits, and previous proton pump inhibitor intake were collected in patient interviews. We evaluated fasting gastric pH and the degree of histological gastritis before eradication of H. pylori.

RESULTS

The overall eradication of H. pylori at 4 weeks was successful in 98 of 137 patients (72%). On the multivariate analysis, a low grade of inflammation in the antrum (p

CONCLUSIONS

These findings indicate that H. pylori eradication therapy with omeprazole, amoxicillin, and clarithromycin is less effective in patients who smoke and more effective in patients with high scores of antral inflammation and fundal activity at baseline biopsy.

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MESH Headings

• Adult
• Amoxicillin/therapeutic use
• Anti-Bacterial Agents/therapeutic use
• Anti-Ulcer Agents/therapeutic use
• Clarithromycin/therapeutic use
• Drug Therapy, Combination
• Female
• Gastritis/drug therapy
• Gastritis/microbiology
• Gastritis/pathology
• Helicobacter Infections/drug therapy
• Helicobacter Infections/microbiology
• Helicobacter Infections/pathology
• Helicobacter pylori
• Humans
• Male
• Middle Aged
• Omeprazole/therapeutic use
• Penicillins/therapeutic use
• Smoking

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Grants Collapse

Affiliation(s)

T Kamada Gastrointestinal Unit, First Department of Internal Medicine, Hiroshima University School of Medicine, Japan
K Haruma
K Komoto
M Mihara
X Chen
M Yoshihara
K Sumii
G Kajiyama
K Tahara
Y Kawamura

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Is smoking still important in the pathogenesis of peptic ulcer disease?

The pathogenesis of peptic ulcer disease is multifactorial, including the effects of Helicobacter pylori, gastric acid, pepsin, gastroduodenal motility, smoking and nicotine, and the complex interaction of an array of other so-called aggressive and protective factors. Since the discovery and acceptance of H. pylori as a major etiologic agent in peptic ulcer disease, the role of smoking has received less attention. Smokers are more likely to develop ulcers, ulcers in smokers are more difficult to heal, and ulcer relapse is more likely in smokers. These clinical observations may be explained by the adverse effects that smoking has on mucosal aggressive and protective factors. Of the aggressive factors, smoking appears to have no consistent effect on acid secretion. However, smoking impairs the therapeutic effects of histamine-2 antagonists, may stimulate pepsin secretion, promotes reflux of duodenal contents into the stomach, increases the risk for and harmful effects of H. pylori, and increases production of free radicals, vasopressin, secretion by the pituitary, secretion of endothelin by the gastric mucosa, and production of platelet activating factor. Smoking also affects the mucosal protective mechanisms. It decreases gastric mucosal blood flow and inhibits gastric mucous secretion, gastric prostaglandin generation, salivary epidermal growth factor secretion, duodenal mucosal bicarbonate secretion, and pancreatic bicarbonate secretion. These adverse effects of smoking on aggressive and protective factors quality it as an important contributor to the pathogenesis of peptic ulcer disease and indicate that smoking plays a significant facilitative role in the development and maintenance of peptic ulcer disease.

Gastric acid secretion and enteric infection in Bangladesh

In developing countries many enteric infections are caused by acid-sensitive pathogens. Failure of the gastric acid barrier to infection has been reported in cholera but gastric acid secretion has been little studied in other enteric infections. We therefore studied basal and stimulated gastric acid in 185 Bangladeshi men admitted to hospital for the treatment of enteric infection. Patients with dysentery (amoebiasis, n = 24 and shigellosis, n = 19) and culture-negative diarrhoea (n = 69) had similar mean gastric acid levels (basal, 3-5 mmol/h; stimulated, 11-17 mmol/h), which remained stable in those patients studied throughout 12 weeks of convalescence. In contrast, patients with secretory diarrhoea caused by cholera or enterotoxigenic Escherichia coli (ETEC) had low gastric acid levels (P < 0.05 compared with other groups) (cholera, n = 34: basal mean 1.8 mmol/h [SD = 2.2], stimulated mean 7.9 mmol/h [SD = 6.4]; ETEC, n = 39: basal mean 2.7 mmol/h [SD = 2.8], stimulated mean 9.4 mmol/h [SD = 7.5]). Cholera patients' gastric acid level rose during convalescence to similar levels to the dysentery patients'. Low gastric acid level was associated with severe disease in patients with cholera (P < 0.02) or ETEC (P < 0.05). Gastric acid level fell with increasing age (P < 0.007) but this did not account for the differences between groups. Gastric acid levels were not associated with Giardia duodenalis or Strongyloides stercoralis co-infection, fever, use of tobacco, or chewing betel nut. Cholera and secretory diarrhoea caused by ETEC may, therefore, partly result from a reduction in gastric acid level which does not occur during dysentery. Factors which impair gastric acid secretion may predispose to diarrhoeal disease in developing countries.

Risk factors associated with refractory peptic ulcers

BACKGROUND & AIMS

The risk factors associated with refractory peptic ulcers are still undefined. The purpose of this study was to identify these factors in a multivariate context.

METHODS

Clinical and endoscopic findings as well as Helicobacter pylori status, gastric secretion analysis, serum gastrin levels, nonsteroidal anti-inflammatory drug (NSAID) use, and objective testing of aspirin use by platelet cyclooxygenase activity were studied in 60 consecutive refractory patients with peptic ulcer and 54 matched nonrefractory controls.

RESULTS

Refractory patients had a longer history of symptomatic ulcer, had an earlier onset, had more frequent relapses, and smoked more during the episode of refractoriness. H. pylori status was similar in both groups, but H. pylori eradication in a subset of refractory patients (23 of 26) was highly effective in healing these ulcers (14 of 23). Globally, NSAID-analgesic abuse (including > 1500 mg/day paracetamol) was present in 40% of refractory patients (P < 0.006). Objective testing showed that 43.7% of NSAID use was surreptitious. Multivariate logistic regression analysis identified only NSAID and analgesic abuse and the number of relapses as individually affecting refractoriness.

CONCLUSIONS

NSAID and analgesic abuse is the single most important exogenous factor associated with refractoriness. H. pylori infection emerges as an important intrinsic factor, but almost a quarter of refractory patients cannot be linked to either NSAID use or H. pylori infection.

Behaviour of acid secretion, gastrin release, serum pepsinogen I, and gastric emptying of liquids over six months from eradication of helicobacter pylori in duodenal ulcer patients. A controlled study

The behaviour of basal and stimulated acid secretion, gastrin release, serum pepsinogen I, and gastric emptying of liquids was studied in 19 consecutive patients with Helicobacter pylori positive duodenal ulcer, over a follow up period of six months. Eleven patients were studied before and at three and six months after eradication with lansoprazole plus amoxicillin and tinidazole (case group), whereas the remainder, with persistent H pylori infection, were studied before and after three and six months from ulcer healing, thus constituting the control group. In the case group, three months after eradication, fasting serum pepsinogen I fell from (mean (SEM)) 91.9 (6.9) (pretreatment) to 72.2 (5.1) ng/l and the integrated gastrin response to a meal reduced from 11,470 (1174) (pretreatment) to 8130 (608) pg/ml/h (p < 0.05). Fasting serum gastrin concentrations and maximal acid output reduced significantly only six months after eradication. In contrast, no significant change of any of these measurements was seen in the control group either at three or six months from healing compared with the pretreatment values. Gastric emptying of liquids did not change over the entire period of follow up in both study groups. In conclusion, eradication of H pylori in duodenal ulcer patients is accompanied by a rapid fall in serum pepsinogen I and plasma gastrin concentrations, whereas a slight but significant reduction of maximal acid secretion takes place later on. In contrast, gastric emptying of liquids does not seem to be influenced by H pylori status.

Systemic diseases associated with nonarteritic anterior ischemic optic neuropathy

PURPOSE

We investigated, in nonarteritic anterior ischemic optic neuropathy, the prevalence of various systemic diseases before or at its onset and the incidence of subsequent morbidity and mortality.

METHODS

We investigated prospectively the presence of systemic diseases before or at the onset of nonarteritic anterior ischemic optic neuropathy in 406 patients. The information was obtained by complete medical history and physical examination. The prevalence rates of systemic diseases in young, middle-aged, and elderly groups were compared with those in the general population. We also analyzed the influence of systemic diseases on subsequent morbidity and mortality.

RESULTS

Compared with the prevalences reported in the general population, our patients in each of the three age groups showed a significantly higher prevalence of arterial hypertension (P < or = .02), diabetes mellitus (P < .01), and gastrointestinal ulcer (P < or = .02). Also, middle-aged and elderly patients showed a significantly higher prevalence of ischemic heart disease (P < .01) and thyroid disease (P < .01). Middle-aged patients had significantly higher rates of chronic obstructive pulmonary disease and cerebrovascular disease (P < or = .01). After onset of anterior ischemic optic neuropathy, patients with both arterial hypertension and diabetes mellitus had a significantly higher incidence of cerebrovascular disease (P < .01).

CONCLUSIONS

Nonarteritic anterior ischemic optic neuropathy is a multifactorial disease in which some systemic diseases may act as predisposing factors and others as precipitating factors. Patients with anterior ischemic optic neuropathy show no significant increase in mortality, but those with both arterial hypertension and diabetes mellitus have significantly (P < .01) increased incidence of cerebrovascular disease.

Effects of smoking and nicotine on the gastric mucosa: a review of clinical and experimental evidence

Epidemiological and experimental evidence have shown that nicotine has harmful effects on the gastric mucosa. The mechanisms by which cigarette smoking or nicotine adversely affect the gastric mucosa have not been fully elucidated. In this report, clinical and experimental data are reviewed. The effects of nicotine from smoking on gastric aggressive or defensive factors are discussed. Nicotine potentiates gastric aggressive factors and attenuates defensive factors; it also increases acid and pepsin secretions, gastric motility, duodenogastric reflux of bile salts, the risk of Helicobacter pylori infection, levels of free radicals, and platelet-activating factor, endothelin generation, and vasopressin secretion. Additionally, nicotine impairs the therapeutic effect of H2-receptor antagonists and decreases prostaglandin synthesis, gastric mucosal blood flow, mucus secretion, and epidermal growth factor secretion. Although many of the studies provide conflicting results, the bulk of the evidence supports the hypothesis that nicotine is harmful to the gastric mucosa.

Effect of nicotine on the enterochromaffin like cells of the oxyntic mucosa of the rat

Smoking has an unfavourable effect on peptic ulcer disease. The pathophysiological mechanisms underlying this effect are not known. The enterochromaffin like (ECL) cell is the cellular source of histamine participating in the regulation of acid secretion. The ECL cell is under functional and trophic control of gastrin and the vagus nerves. Nicotine may affect acid secretion through vagal pathways. Furthermore, nicotine may also stimulate neuroendocrine cells. The present study examined if chronic nicotine administration could stimulate the function and growth of the ECL cell. Rats inhaled nicotine vapour at a concentration of approximately 6.2 mumol/m3, 20 hours/day, 5 days/week for 11 weeks. Steady state plasma nicotine concentration was 461.8 (137.5 (SD)) nmol/l. The ECL cell density, histamine content and histidine decarboxylase activity of the oxynitic mucosa were similar to the controls. We also examined the effect of acute nicotine stimulation on the acid output and histamine release from the totally isolated vascularly perfused rat stomach. Nicotine did not stimulate acid secretion or histamine release. Thus no evidence could be provided to support the hypothesis that nicotine exerts its negative effects on peptic ulcer disease by stimulating the ECL cell.