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| 2. |
- Berg, Anna, 1975-, et al.
(författare)
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Effect of nitric oxide on histamine-induced cytological transformations in parietal cells in isolated human gastric glands
- 2007
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Ingår i: Digestive Diseases and Sciences. - : Springer Science and Business Media LLC. - 0163-2116 .- 1573-2568. ; 52:1, s. 126-136
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have shown that nitric oxide (NO) inhibits histamine-induced gastric acid secretion in isolated human gastric glands. NO synthase has been found to be present in the human oxyntic mucosa and has been suggested to serve as a paracrine regulator of gastric acid secretion. Histamine stimulation of parietal cells induces cytoskeletal rearrangements, recruitment of H +/K +-ATPase-rich tubulovesicles to the apical membrane and expansion of intracellular canaliculi. The aim of the present study was thus to investigate (i) the effect of an NO donor on histamine-induced cytological transformations and (ii) the influence of increased [Ca 2+] i on NO-induced morphological changes in human parietal cells. Human gastric glands were isolated and subjected to the NO donor SNAP prior to histamine administration. [Ca 2+] i was increased by photolysis of the caged Ca 2+ compound NP-EGTA. The distribution of F-actin, ezrin, and H +/K +-ATPase was assessed by confocal microscopy. Ultrastructural analysis was performed using transmission electron microscopy. SNAP did not influence the histamine-induced translocation of F-actin, ezrin, and H +/K +-ATPase but prevented an increase in the canalicular size. Elevation of [Ca 2+] i in resting cells was found to mimic histamine-induced intraparietal cell transformations; however, NO-induced parietal cell morphology was unaffected by a rise in [Ca 2+] i. These results indicate that NO inhibits secretion of fluid into the canalicular lumen without affecting membrane recruitment and that this effect is Ca 2+-insensitive. © 2006 Springer Science+Business Media, Inc.
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| 3. |
- Berg, Anna, 1975-, et al.
(författare)
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Nitric oxide-an endogenous inhibitor of gastric acid secretion in isolated human gastric glands
- 2004
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Ingår i: BMC Gastroenterology. - 1471-230X. ; 4:16
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundEndothelial nitric oxide synthase (eNOS) has previously been detected in the glandular part of the human gastric mucosa. Furthermore, nitric oxide (NO) has been shown to influence gastric secretion in various animal models. The present study was conducted to investigate the influence of exogenously and endogenously derived NO on histamine- and cAMP-stimulated gastric acid secretion in isolated human oxyntic glands.MethodsOxyntic glands were isolated from human gastric biopsies and were subsequently pre-treated with NO donors and nitric oxide synthase inhibitors and then exposed to histamine or dibutyryl-cAMP (db-cAMP). The secretory response of the glands was determined as accumulation of [14C]aminopyrine.ResultsThe histamine- or db-cAMP-induced acid secretion was attenuated by L-arginine, a known source of endogenous NO, and also by the NO-donors sodium nitroprusside (SNP) and S-nitroso-N-acetyl-penicillamine (SNAP). Pre-treatment with either of the NOS inhibitors NG-nitro-L-arginine methyl ester (L-NAME) or NG-nitro-L-arginine (L-NNA) enhanced the secretory response.ConclusionOur results show that NO inhibits gastric acid secretion in isolated human gastric glands, and that there is endogenous formation of NO within the glandular epithelium in the vicinity of the parietal cells.
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| 4. |
- Berg, Anna, 1975-, et al.
(författare)
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Nitric oxide inhibits gastric acid secretion by increasing intraparietal cell levels of cGMP in isolated human gastric glands
- 2005
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Ingår i: American Journal of Physiology - Gastrointestinal and Liver Physiology. - : American Physiological Society. - 0193-1857 .- 1522-1547. ; 289:6, s. G1061-G1066
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Tidskriftsartikel (refereegranskat)abstract
- We have previously identified cells containing the enzyme nitric oxide (NO) synthase (NOS) in the human gastric mucosa. Moreover, we have demonstrated that endogenous and exogenous NO has been shown to decrease histamine-stimulated acid secretion in isolated human gastric glands. The present investigation aimed to further determine whether this action of NO was mediated by the activation of guanylyl cyclase (GC) and subsequent production of cGMP. Isolated gastric glands were obtained after enzymatic digestion of biopsies taken from the oxyntic mucosa of healthy volunteers. Acid secretion was assessed by measuring [14C]aminopyrine accumulation, and the concentration of cGMP was determined by radioimmunoassay. In addition, immunohistochemistry was used to examine the localization of cGMP in mucosal preparations after stimulation with the NO donor S-nitroso-N-acetylpenicillamine (SNAP). SNAP (0.1 mM) was shown to decrease acid secretion stimulated by histamine (50 μM); this effect was accompanied by an increase in cGMP production, which was histologically localized to parietal cells. The membrane-permeable cGMP analog dibuturyl-cGMP (db-cGMP; 0.1–1 mM) dose dependently inhibited acid secretion. Additionally, the effect of SNAP was prevented by preincubating the glands with the GC inhibitor 4H-8-bromo-1,2,4-oxadiazolo[3,4-d]benz[b][1,4]oxazin-1-one (10 μM). We therefore suggest that NO in the human gastric mucosa is of physiological importance in regulating acid secretion. Furthermore, the results show that NO-induced inhibition of gastric acid secretion is a cGMP-dependent mechanism in the parietal cell involving the activation of GC.
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| 5. |
- Borch, Kurt, 1944-, et al.
(författare)
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Prevalence of gastroduodenitis and Helicobacter priori infection in a general population sample : relations to symptomatology and life-style
- 2000
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Ingår i: Digestive Diseases and Sciences. - 0163-2116 .- 1573-2568. ; 45:7, s. 1322-1329
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Tidskriftsartikel (refereegranskat)abstract
- Some benign and malignant diseases develop on the background of chronic gastritis or duodenitis. The present study was performed in order to determine the magnitude of these background changes with relations to symptomatology and life style in the general population. Examinations were performed in 501 volunteers (age 35–85 years). Fifty percent had gastritis; this was associated with H. pylori in 87%. H. pylori-negative gastritis was associated with regular use of NSAIDs [odds ratio 3.8 (1.6–9.9)]. Duodenitis, observed in 32%, was associated with H. pylori infection [odds ratio 2.3 (1.3–4.6)], previous cholecystectomy [odds ratio 3.6 (1.1–16.1)], and regular use of NSAIDs [odds ratio 3.0 (1.4–7.1)]. Neither gastritis nor duodenitis was associated with smoking or alcohol consumption. The rate of digestive symptoms did not differ between subjects with and without uncomplicated gastritis or duodenitis. In conclusion, half of this adult population had gastritis strongly associated with H. pylori infection. Gastritis without H. pylori infection was frequently associated with regular NSAID intake. One third had duodenitis, which was associated with H. pylori infection as well as with regular use of NSAIDs and previous cholecystectomy. Digestive symptoms were not overrepresented in uncomplicated gastritis or duodenitis.
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| 6. |
- Redéen, Stefan, 1961-
(författare)
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Chronic Gastritis : Diagnosis, natural history and consequences
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background & alms: The main cause of chronic gastritis is Helicobacter pylori (H. pylori). Clinical manifestations of chronic gastritis are ulcer disease, gastric cancer and mucosa-associated lymphoma tissue (MALT) lymphoma in the stomach. It is uncertain whether gastritis can be diagnosed macroscopically at endoscopy. H. pylori infection may be diagnosed by several different methods, the accuracy of which needs to be explored. Some individuals with H. pylori related chronic gastritis will develop atrophy of the gastric mucosa. This condition is the main risk factor for cancer development and may also be associated with vitamin B12 deficiency leading to hyperhomocysteinaemia. The natural history of chronic gastritis in terms of development of atrophy and ulcer disease in the adult general population is largely unknown.Material & methods: A sample of 50 I volunteers from the general population in the municipality of Linköping was examined with esophago-gastro-duodenoscopy (EGD) with biopsy. Blood samples were collected in the fasting state and the subjects answered a questionnaire about lifestyle factors, medications and disease history. In-hospital diagnoses and causes of death during follow-up of the population were extracted from local and national patient files. Re-examination was done in 314 subjects after a median follow-up interval of 8.4 years. Five diagnostic tests (serology UBT, RUT, culture and microscopic examination) for H. pylori infection were used at re-examination.Results: The best values of sensitivity and specificity were for visible vessels in relation to microscopic presence of severe atrophy in the gastric corpus mucosa (80% and 87%, respectively). There was a positive relation of S-homocysteine to male gender, age, S-cystatin C (renal function), methylenetetrahydrofolate reductase 677TT genotype and atrophic gastritis. Logistic regression analysis showed an association of S-homocysteine higher than 14.5 Ilmol/L to cardiovascular diseases (OR 2.05), but not to dementia overall.The incidence ofulcer was 0.45 per 100 person years and was associated with weekly NSAID use, weekly alcohol consumption (OR 19.4) and smoking (OR 31.0), but not with H. pylori status. Among subjects with chronic gastritis, the incidence of atrophy of the corpus mucosa was 1.4 per 100 person years. Considering diagnostic test for H. pylori infection the accuracy was 0.86 for serology, 0.94 for UBT, 0.94 for RUT, 0.93 for culture, and 0.93 for histological examination. There was a strong correlation between the results of UBT and the histological scores of H. pylori colonisation as well as between the results of UBT and scores of RUT.Conclusions: The occurrence of chronic gastritis or H. pylori infection is not evaluable macroscopically at gastroscopy, except for the absence of rugae or visible vessels in the gastric corpus mucosa. Serum Hcy concentrations are dependent on gender, age, the levels of vitamin B12 and folate, renal function, the occurrence of atrophic gastritis and the MTHFR 677 TT genotype. Elevated S-Hcy is a risk factor for cardiovascular disease. The incidence of atrophy of the corpus mucosa is 1.4 per 100 person years for chronic gastritis overall. Chronic gastritis with or without H. pylori infection is a variable process in which milder degrees of atrophy of the corpus mucosa may appear or disappear. In contrast, moderate-to-severe atrophy of the corpus mucosa rarely regresses. Age and the degree of chronic inflammation in the gastric corpus mucosa are major risk factors for the development of atrophy. The incidence of ulcer was 0.45 per 100 person years. There are only minor differences in accuracy between the three invasive tests for H. pylori infection. The UBT is recommended for situations where endoscopy is not required. RUT may be recommended as the first non-invasive method of choice in the diagnosis of H. pylori infection.
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| 7. |
- Redéen, Stefan, 1961-, et al.
(författare)
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Relationship of gastroscopic features to histological findings in gastritis and Helicobacter pylori infection in a general population sample
- 2003
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Ingår i: Endoscopy. - : Georg Thieme Verlag KG. - 0013-726X .- 1438-8812. ; 35:11, s. 946-950
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Tidskriftsartikel (refereegranskat)abstract
- Background and study aim: Various gastroscopic features may be interpreted as signs of gastritis, but the significance of such features in relation to histomorphology is uncertain. The aim of this study was to determine how macroscopic findings were related to histomorphological changes and the presence of Helicobacter pylori in the gastric mucosa, in a sample of the general population. Subjects and methods: 488 adult individuals, randomly selected from a general population, were screened with gastroscopy and biopsy. The macroscopic features recorded were erythema (diffuse, spotty, linear), erosions, absence of rugae in the gastric corpus, and presence of visible vessels. Gastritis was classified microscopically according to the Sydney system. The presence of H. pylori was determined histologically and using the urease test on fresh biopsy specimens. Results: The sensitivity and specificity of absence of rugae for moderate to severe atrophic gastritis in the gastric corpus were 67% and 85%, respectively. Corresponding valuers for severe atrophy were 90% and 84%. The sensitivity and specificity of the presence of visible vessels for moderate to severe atrophy in the corpus were 48% and 87%, and for severe atrophy the values were 80% and 87%, respectively. Considering the antrum, the sensitivity and specificity of the presence of visible vessels for moderate to severe atrophy was 14% and 91%, respectively. With regard to chronic inflammation (moderate to severe in the corpus or antrum), none of the features, alone or in combination, showed a sensitivity of more than 56%. No endoscopic features (alone or in combination) showed a sensitivity of more than 57 % for H. pylori infection. Conclusions: Except for the absence of rugae and visible vessels in the gastric corpus, macroscopic features as observed during gastroscopy are of very limited value in the evaluation of whether or not gastritis or H. pylori infection are present. This is in accordance with most previous studies in patient populations, and it must be emphasized that the diagnosis of gastritis should be based on histological examination of the gastric mucosa.
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| 8. |
- Redéen, Stefan, 1961-, et al.
(författare)
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Reliability of diagnostic tests for Helicobacter pylori infection
- 2011
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Ingår i: Gastroenterology Research and Practice. - : Hindawi. - 1687-6121 .- 1687-630X. ; 2011:940650
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Helicobacter pylori (H.pylori) infection is very common worldwide. A reliable diagnosis is crucial for patients with H.pylori related diseases. At follow-up it is important to confirm that eradication therapy has been successful. There is no established gold standard for the diagnosis of H.pylori infection. Material and Methods: A sample of 304 volunteers from the general population was screened for H.pylori infection with serology, 13C-urea breath test (UBT), rapid urease test (RUT) on fresh biopsy, culture from biopsy and histological examination. Each method was tested against the other methods (except serology) taken together as gold standard. Result: The sensitivity was 0.99 for serology 0.92 for UBT, 0.96 for RUT, 0.99 for culture and 0.95 for histological examination. Corresponding specificities were 0.82, 0.94, 0.93, 0.90 and 0.92, respectively. The accuracy was 0.86 for serology, 0.94 for UBT, 0.94 for RUT, 0.93 for culture and 0.93 for histology. There was a strong correlation between the results of UBT and histological scores for H.pylori colonization as well as between the results of UBT and the scores of RUT. Conclusion: There were only minor differences in accuracy between three invasive tests for H.pylori infection in this population. RUT may be recommended as first choice since a result is obtained within hours. The accuracy of UBT was comparable to the invasive tests and it is recommended for situations when endoscopy is not needed.
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| 9. |
- Redéen, Stefan, 1961-
(författare)
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The Trend of Tranexamic Use in Upper Gastrointestinal Bleeding Ulcers
- 2017
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Ingår i: Gastroenterology Research. - Montreal, Canada : Elmer Press Inc.. - 1918-2805 .- 1918-2813. ; 10:3, s. 159-165
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Tidskriftsartikel (refereegranskat)abstract
- Background: Bleeding ulcer is a common condition, especially among the elderly population. Tranexamic acid (TXA) has been successfully used for many bleeding conditions. Its use in patients with bleeding ulcer is inclusive yet. The aim of this study was to provide an overview of the prescription of TXA.Methods: This retrospective cohort study was performed as a review of medical records at the Surgery Department, University Hospital in Linkoping. Patients with complete esophagogastroduodenoscopy and ulcer disease were included and divided on the basis of treatment with TXA or not. Differences between the groups were statistically analyzed.Results: The main part of the prescription of TXA, 65%, occurred during 2010 and 2011, and 35% between 2012 and 2013 (P < 0.05). In the group treated with TXA, 84% needed blood transfusion, compared to 64% in the control group (P = 0.039). Of the patients treated with TXA, 18% were re-bleeding compared to 14% of the controls (P = 0.594). Median value for days at hospital was 5 in the tranexamic group and 3 in the control group (P = 0.005).Conclusion: The prescription of TXA has declined between 2010 and 2013. TXA was more often prescribed to patients with more severe gastrointestinal (GI) bleeding ulcer disease. Further investigation is needed to conclude the significance of tranexamic acid in patients with GI bleeding ulcer disease.
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