Search

This study analyzed the association of functionally significant SNPs of matrix metalloproteinase (MMP) genes in the development of peptic ulcer disease (PUD) in Caucasians from Central Russia. Ten SNPs of the MMP-1, MMP-2, MMP-3, MMP-8, and MMP-9 genes were analyzed for association with PUD in a cohort of 798 patients with PUD (including 404 H. pylori-positive and 394 H. pylori-negative) and 347 H. pylori-negative controls using logistic regression and assuming the additive, recessive, and dominant genetic models. The variants of MMP-1, MMP-2, MMP-3, and MMP-8 did not manifest any significant associations with the diseases. Five SNPs of the MMP-9 gene demonstrated such association. Allele G of the rs17576 MMP-9 locus conferred a higher risk for PUD (OR adj  = 1.31, p perm  = 0.016), haplotype AACG of loci rs17576-rs3787268-rs2250889-rs17577 of the MMP-9 gene decreased risk for PUD (OR adj  = 0.17, p perm  = 0.003). Also, allele C of rs3918249, allele G of rs17576 and haplotype CG of rs3918249-rs17576 of the MMP-9 gene increased risk for H. pylori-positive PUD (OR adj  = 1.82, p perm  = 0.002; OR adj  = 1.53-1.95 p perm  = 0.001-0.013 and OR adj  = 1.49 p perm  = 0.009 respectively). The above loci and 50 linked to them possess significant regulatory effects and may affect the alternative splicing of four genes and the expression of 17 genes in various organs and tissues related to the PUD pathogenesis.

Helicobacter pylori infect millions of people around the world. It occupies a niche in the human gastrointestinal tract characterized by high expression of a repertoire of carbohydrates. ABO and Lewis histo-blood group systems are controlled by genes coding for functional glycosyltransferases which synthesize great diversity of related fucosylated carbohydrate in different tissues, including gastrointestinal mucosa, and exocrine secretions. The structural diversity of histo-blood group carbohydrates is highly complex and depends on epistatic interactions among gene-encoding glycosyltransferases. The histo-blood group glycosyltransferases act in the glycosylation of proteins and lipids in the human gastrointestinal tract allowing the expression of a variety of potential receptors in which H. pylori can adhere. These oligosaccharide molecules are part of the gastrointestinal repertoire of carbohydrates which act as potential receptors for microorganisms, including H. pylori. This Gram-negative bacillus is one of the main causes of the gastrointestinal diseases such as chronic active gastritis, peptic ulcer, and cancer of stomach. Previous reports showed that some H. pylori strains use carbohydrates as receptors to adhere to the gastric and duodenal mucosa. Since some histo-blood group carbohydrates are highly expressed in one but not in others histo-blood group phenotypes it has pointed out that quantitative differences among them influence the susceptibility to diseases caused by H. pylori. Additionally, some experiments using animal model are helping us to understand how this bacillus explore histo-blood group carbohydrates as potential receptors, offering possibility to explore new strategies of management of infection, disease treatment, and prevention. This text highlights the importance of structural diversity of ABO and Lewis histo-blood group carbohydrates as facilitators for H. pylori infection., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: The circadian rhythm, as part of a broad time structure (chronome) of lipid peroxides and antioxidant defense mechanisms may relate to prevention, efficacy and management of preventive and curative chronotherapy., Methods: Fifty newly diagnosed patients with peptic ulcers, 30-45 years of age, and 60 age-matched clinically healthy volunteers were synchronized for one week with diurnal activity from about 06:00 to about 22:00 and nocturnal rest. Breakfast was served around 08:30, lunch around 13:30 and dinner around 20:30. Drugs known to affect the free-radical systems were not taken. Blood samples were collected at 6-hour intervals for 24h under standardized, presumably 24-hour synchronized conditions. Plasma lipid peroxides, in the form of malondialdehyde (MDA), blood superoxide dismutase (SOD), glutathione peroxide (GPx), glutathione reductase (GR), catalase (CAT) activities, and serum total protein, albumin, ascorbic acid, total serum cholesterol, and HDL-cholesterol concentrations were determined., Results: By population-mean cosinor analysis, a marked circadian variation was demonstrated for all variables in healthy subjects and in ulcer patients (p<0.001). As compared to controls, patients had a lower MESOR of MDA, SOD, GPx, GR, ascorbic acid, and HDL-C. They also had smaller circadian amplitude of SOD, CAT, GPx, GR, ascorbic acid, T-C, and HDL-C, but larger circadian amplitude of MDA and albumin. As compared to healthy subjects, the circadian acrophase of ulcer patients occurred later for MDA and GR and earlier for GPx., Conclusion: Mapping circadian rhythms, important chronome components that include trends with age and extra-circadian components characterizing antioxidants and pro-oxidants, is needed for exploring their putative role as markers in the treatment and management of peptic ulcers., (Copyright © 2015. Published by Elsevier B.V.)

Introduction: The main enzyme responsible for metabolism of proton pump inhibitors (PPI) is cytochrome P-4502C19 (CYP2C19). Among all CYP2C19 polymorphisms ulrarapid CYP2C19*17 allele plays an important role in clinical practice as in CYP2C19*17 allele carriers acid suppression achieved with PPI including eradication regimens may be insufficient., The Aim of the Study: To find the frequency of CYP2C19 ultrarapid metabolizers in Russian patients with peptic ulcer, Methods: We retrospectively reviewed the results of pharmacogenetic tests of 971 Russian patients with endoscopically and histologically proven ulcers, 428 male (44%) and 543 female (56%). The mean age was 44.6 ± 11.9 years (range 15-88 years). DNA was extracted from EDTA whole blood samples (10 mL). The polymorphisms CYP2C19 *2, *3 *17 were evaluated using real-time polymerase chain reaction (RT-PCR)., Results: We found that among 971 peptic ulcer patients ultrarapid metabolizers (CYP2C19*1/*17, CYP2C19*17/*17) were the most frequent genotype--39.75%. Extensive metabolizers with CYP2C19*1/*1 genotype were less frequent--32.65%. Frequency of poor and intermediate metabolizers was found to be 1.5% and 25.85% respectively. We were the first to investigate CYP2C19*17 allele frequency in Russian patients with peptic ulcer which was found to be 27.4%., Conclusion: High frequency of CYP2C19 ultrarapid metabolizers in Russian patients with peptic ulcer may be associated with insufficient response to proton pump inhibitors.

One of the most likely causes of the lack of effectiveness of eradication therapy of peptic ulcer associated with Helicobacter pylori, is a feature of omeprazole metabolism by cytochrome CYP2C19. The paper work presents evidence that the rate of reduction of the clinical picture and the likelihood of scarring ulcers and eradication rates higher in patients slow metabolizers of omeprazole.

Background: Antioxidant supplements with existing drugs may confer better therapeutic efficacy in oxidative stress related diseases. The purpose of the present work was to characterize the interaction and investigate the protective effect of H2 blocker famotidine and gallic acid in combination against experimentally induced peptic ulcer., Methods: Preventive effect of gallic acid and famotidine in different combinations was investigated against aspirin plus pyloric ligation induced ulcer in rat. Ulcer index, gastric juice volume, pH, other biochemical parameters of gastric juice and antioxidant activity using stomach tissue were estimated., Results: Pretreatment with gallic acid and famotidine in combinations for 7 days, protected the gastric mucosa significantly (p<0.05, 0.01), which was evidenced by decrease in ulcer index, gastric juice volume, free and total acidity, total protein, pepsin and DNA content, and increase in pH, carbohydrates concentration in gastric juice. Combination treatment increases levels of superoxide dismutase, catalase, reduced glutathione, glutathione reductase and glucose-6-phosphate dehydrogenase, and decreases lipid peroxidation, myloperoxidase in stomach tissue. Along with higher dose combination, lower dose combinations like gallic acid (50mg/kg) plus famotidine (10mg/kg) also offered better antiulcer activity than their individual effect. Histopathological studies confirmed their antiulcer activity., Conclusion: Combination treatments confer synergistic protective effect against peptic ulcer in rats, which was related to the gastroprotective, antisecratory and antioxidant activity of combination treatment. Results proved that use of gallic acid with existing antiulcer drug will be more useful in the prevention/management of peptic ulcer., (Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.)

Objective: Cryptogenic multifocal ulcerating stenosing enteritis (CMUSE) is an extremely rare, but devastating, disease of unknown aetiology. We investigated the genetic basis of this autosomal recessive condition in a pair of affected siblings who have 40-year histories of catastrophic gastrointestinal and extraintestinal disease., Design: Genome-wide single-nucleotide polymorphism homozygosity mapping in the two affected family members combined with whole-exome sequencing of one affected sibling. This was followed by confirmatory Sanger sequencing of the likely disease-causing sequence variant and functional studies in affected and unaffected family members., Results: Insertion/deletion variation analysis revealed the presence of a homozygous 4 bp deletion (g.155574&#95;77delGTAA) in the PLA2G4A gene, located in the splice donor site directly after exon 17 (the penultimate exon) of the gene in both affected siblings. This introduces a frameshift of 10 amino acids before a premature stop codon (p.V707fsX10), which is predicted to result in the loss of 43 amino acids (residues 707-749) at the C-terminus of cytosolic phospholipase A2-α (cPLA(2)α). cPLA(2)α protein expression was undetectable in the gut of both siblings, with platelet aggregation and thromboxane A(2) production, as functional assays for cPLA(2)α activity, grossly impaired., Conclusions: We have identified mutations in PLA2G4A as a cause of CMUSE in two affected siblings. Further studies are needed to determine if mutations in this gene are also responsible for disease of a similar phenotype in other cases.

Aims: Morus alba is a plant that is well known for its medicinal properties. In Asian countries, it is traditionally used for anti-inflammatory, hypoglycemic, hypolipidemic and antioxidant applications. The aim of this study was to evaluate the antiulcer and antioxidant activity of a new steroid from M. alba., Main Methods: Column chromatography was employed to isolate different compounds from M. alba. The molecular structures of the compounds were characterized via IR, UV, (1)H NMR, (13)C NMR and mass spectroscopic methods. A newly isolated compound was tested for antiulcer activity in pylorus-ligation- and ethanol-induced ulcer models and biochemically estimated for SOD, CAT, GR, GPx, GSH and LPO levels., Key Findings: Five new compounds were isolated; one of these was a new steroid named albosteroid. This new compound exhibits significant (P<0.05, P<0.01 and P<0.001) antiulcer activity in pylorus-ligation- and ethanol-induced ulcer models. Furthermore, this compound showed significant dose-dependent reversal of ethanol-diminished activity in antioxidant enzymes, such as SOD, CAT, GPx and GSH, and reduced the ethanol-elevated levels of GR and LPO., Significance: The present study clearly demonstrates the anti-ulcer and antioxidant potential of compound 1, which was supported by macroscopic and histopathological studies of stomach wall tissues of differently treated groups of rats., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Aim: Helicobacter pylori infection, though common, leads to gastric cancer (GC) in less than 1% individuals, suggesting the role of host factors. We previously reported the role of glutathione-S-transferase (GST) polymorphisms, the gene encoding a carcinogen-detoxifying enzyme, in GC. This study was aimed to evaluate GST enzyme activity, GST polymorphism, glutathione (GSH) levels and H. pylori in patients with GC., Methods: GST and GSH levels were estimated in gastric biopsies of 52 patients with GC, 37 functional dyspepsia (FD) and 39 peptic ulcer (PU), and correlated with H. pylori (ELISA) infection and GST polymorphisms. GST polymorphisms were separately analyzed in relationship to H. pylori in 82 GC, 72 FD, 53 PU and 89 healthy controls (HC)., Results: GST activity was lower in patients with GC in comparison to PU (p = 0.03), but GSH levels were comparable. GSTT1 null genotype (GSTT1*0) and simultaneous deletion of both GSTT1 and GSTM1 genes was associated with lower enzyme activity (p = 0.02 and 0.01, respectively). GST and GSH levels in H. pylori positive and negative patients with GC, FD and PU were comparable. Presence of H. pylori infection along with GSTT1*0 (p = 0.006) and GSTM1*0 (p = 0.05) was associated with lower enzyme activity. GSTT1*0 was associated with higher odds ratio (OR) of GC in presence of H. pylori (GC vs. HC: p = 0.02, OR 2.6 [95% CI = 1-6] vs. p = 0.7, 1.3 [0.4-5.0]; GC vs. PU: p = 0.04, OR 3 [95% CI = 1-9] vs. not applicable (OR could not be computed as frequency of GSTT1*0 in H. pylori negative patients with PU was zero)]., Conclusions: GC is associated with reduced GST activity. Odds ratio of GC associated with GSTT1*0 is enhanced in presence of H. pylori probably due to combined effect of both on enzyme activity.

Wound healing of the gastrointestinal mucosa is essential for the maintenance of gut homeostasis and integrity. Enteric glial cells play a major role in regulating intestinal barrier function, but their role in mucosal barrier repair remains unknown. The impact of conditional ablation of enteric glia on dextran sodium sulfate (DSS)-induced mucosal damage and on healing of diclofenac-induced mucosal ulcerations was evaluated in vivo in GFAP-HSVtk transgenic mice. A mechanically induced model of intestinal wound healing was developed to study glial-induced epithelial restitution. Glial-epithelial signaling mechanisms were analyzed by using pharmacological inhibitors, neutralizing antibodies, and genetically engineered intestinal epithelial cells. Enteric glial cells were shown to be abundant in the gut mucosa, where they associate closely with intestinal epithelial cells as a distinct cell population from myofibroblasts. Conditional ablation of enteric glia worsened mucosal damage after DSS treatment and significantly delayed mucosal wound healing following diclofenac-induced small intestinal enteropathy in transgenic mice. Enteric glial cells enhanced epithelial restitution and cell spreading in vitro. These enhanced repair processes were reproduced by use of glial-conditioned media, and soluble proEGF was identified as a secreted glial mediator leading to consecutive activation of epidermal growth factor receptor and focal adhesion kinase signaling pathways in intestinal epithelial cells. Our study shows that enteric glia represent a functionally important cellular component of the intestinal epithelial barrier microenvironment and that the disruption of this cellular network attenuates the mucosal healing process.

We studied the effect of NSAIDs on the stomach lining and intestines. Animals received the selective and nonselective NSAIDs. Revision of the abdominal cavity was performed after 24 hours and 14 days. In the mucosa was determined by the levels of prostaglandins and measured the index of damage. Lowering the synthesis of PG in the mucosa of the gastrointestinal tract contributes to the formation damage. After 24 hours when receiving non-selective COX inhibitors and selective inhibitors of COX-2 revealed the presence of mucous membrane lesions that are smaller than in groups of animals treated with selective NSAIDs. After 14 days of reception remains a low level of GHGs in the group of animals treated with nonselective NSAIDs. Visually mucosal damage are insignificant, but in the submucosal layer preserved microcirculatory blood flow disturbances.

The Purpose of the Study: To study role of E2 and F2alpha prostaglandins in development of erosive-ulcerative lesions of gastrointestinal tract., Materials and Methods: were examined patients with mucosal erosive-ulcerative and inflammatory lesions of gastrointestinal tract, as well as patients with osteoarthritis who received selective and non selective NSAIDs. Determination of E2 and F2alpha endogenous PG group was investigated with help of immunefuoration method with help of R&D Systems, Inc. Control group was 15 healthy patients., Results: in presented work you can find that there is relationship between degree of reduction of PG level and severity of gastrointestinal mucosal lesion area. The lowest values of PGE2 and PG F2alpha observed in patients with gastric ulcer disease, especially during exacerbation. Patients with low PG synthesis in body increases likelihood of gastropathy as to reception of non-selective COX inhibitors, and at receiving selective COX-2 inhibitors.

A comparative kinetic study of the inhibition of urea hydrolysis by 9 substituted 1,5,6,7-tetrahydro-4H-benzimidazol-4-ones (BI I-IX) has been carried out. The inhibition had reversibl competitive character; the inhibition constants K(i), varied from 29 up to 754 microM in dependence of the structure of BI I-IX. Three BI I-III, having the K(i) values from 29 to 82 microM, may be used as the potential therapeutic agents for gastroenterology for treatment of stomach and duodenal ulcers.

Inhibition of gastric acid secretion is the mainstay of the treatment of gastroesophageal reflux disease and peptic ulceration; therapies to inhibit acid are among the best-selling drugs worldwide. Highly effective agents targeting the histamine H2 receptor were first identified in the 1970s. These were followed by the development of irreversible inhibitors of the parietal cell hydrogen-potassium ATPase (the proton pump inhibitors) that inhibit acid secretion much more effectively. Reviewed here are the chemistry, biological targets and pharmacology of these drugs, with reference to their current and evolving clinical utilities. Future directions in the development of acid inhibitory drugs include modifications of current agents and the emergence of a novel class of agents, the acid pump antagonists.

Background: Polymorphisms in the immune related genes are important in the clinical outcome of Helicobacter pylori infection. Myeloperoxidase -463 G/A polymorphism has been shown to reduce enzyme expression and activity., Objective: the aim of the present study is to investigate the association of myeloperoxidase G-463A polymorphism with clinical outcome of Helicobacter pylori infection., Methods: two hundred and eighty five patients with positive culture of Helicobacter pylori from their gastric biopsies are included in this study. Human leukocyte DNA was extracted using salting out method and myeloperoxidase G-463A polymorphism was investigated by PCR-RFLP. All clinicopathological data were collected from individual records., Results: When the patients were categorized according to the high (GG) and low + intermediate (AG+AA) genotypes of myeloperoxidase producers, there was a significant association between myeloperoxidase G-463A genotypes and clinical outcome of Helicobacter pylori infection (p=0.006). In search for combined effect of cagA status and myeloperoxidase genotypes on clinical presentations, only in cagA- Helicobacter pylori infected patients a significant association between myeloperoxidase genotypes and clinical outcome was found (p=0.0001). Also this association was found only in patients infected with vacA s1m1 genotype (p=0.008)., Conclusions: Our findings suggest that the myeloperoxidase G-463A polymorphism is a host genetic factor which determines the clinical outcome of Helicobacter pylori infection. Moreover, the combination of host and bacterial genetics could provide a better understanding of clinical outcome after infection with Helicobacter pylori.

Cyclooxygenase-1 (COX-1) has been regarded as a constitutively expressed enzyme that generates prostaglandins for gastrointestinal integrity. We attempted to clarify the association between potentially functional polymorphisms (T-1676C and A-842G/C50T) in the COX-1 gene promoter and gastroduodenal disorders in a Japanese population. The study was performed with 480 stocked DNAs from subjects (gastric ulcers in 93 subjects and duodenal ulcers in 44) with no evidence of gastric malignancy. We employed the PCR-SSCP method to detect gene polymorphisms. The severity of histological chronic gastritis in antral biopsy specimens was classified according to the updated Sydney system. The T-1676C polymorphism was not associated with either gastric mucosal atrophy or infiltration of inflammatory cells into gastric mucosa. In non-NSAID (non-steroidal anti-inflammatory drug) users, male gender and Helicobacter pylori (HP) infection were significantly associated with both gastric and duodenal ulcers, whereas the -1676T allele carrier was significantly associated with only gastric ulcers (OR, 2.86; 95% CI, 1.29-6.34). In NSAID users, the number of -1676T alleles was significantly associated with developing gastroduodenal ulcers (OR, 5.80; 95% CI, 1.59-21.1), whereas male gender and HP infection were not. The -842T/ C50T polymorphism was not detected in any of the 480 Japanese subjects. In conclusion, a carrier of the -1676T allele in the COX-1 gene promoter, as well as HP infection and male gender, seem to be significant risk factors for developing gastric ulcers, and the number of -1676T alleles was also a significant risk factor for the NSAID-induced ulcer, whereas the frequency of the A-842G polymorphism was thought to be very rare in the Japanese population.

Background and Aims: Several nonsteroidal anti-inflammatory drugs (NSAIDs) are metabolized by the cytochrome P450 2C9 (CYP2C9). Two common variants of the CYP2C9 gene (CYP2C9*2 and *3) were reported to significantly affect the activity of the CYP2C9 enzyme. The aim of this study was to evaluate the impact of CYP2C9 polymorphisms on the risk of gastroduodenal bleeding in acute NSAID users., Methods: This case-control study included 26 patients with endoscopically documented NSAID-related gastroduodenal bleeding lesions and 52 age-, sex- and NSAID use-matched controls with no lesions at endoscopy. Both cases and controls were Helicobacter pylori negative and acute users of an NSAID or cycloxygenase-2 inhibitor that undergoes CYP2C9 metabolism (ie, celecoxib, diclofenac, ibuprofen, naproxen, or piroxicam). Two marker single nucleotide polymorphisms in the CYP2C9 gene, identifying the CYP2C9 *2 and *3 allele, were evaluated in all subjects., Results: Setting the CYP2C9*1/*1 wild type as reference, significantly higher frequencies of CYP2C9*1/*3 (34.6% vs 5.8%; P < .001; odds ratio [OR], 12.9; 95% confidence interval [CI], 2.917-57.922) and CYP2C9*1/*2 (26.9% vs 15.4%; P = .036; OR, 3.8; 95% CI, 1.090-13.190) were identified in bleeding versus control patients, whereas no differences between bleeding and controls were observed in the distribution of CYP2C9*2/*3 heterozygotes. Considering allele carriers, the presence of CYP2C9*3 allele was associated with a significant high risk of bleeding (adjusted OR, 7.3; 95% CI, 2.058-26.004)., Conclusions: CYP2C9 genotyping may identify subgroups of persons who potentially are at increased risk of gastroduodenal bleeding when treated with NSAIDs metabolized by CYP2C9. Further studies that evaluate the effectiveness of a strategy using CYP2C9 genotyping in NSAID users are needed before genotyping is introduced into clinical practice.

Aim: To evaluate the efficacy of telomerase activity assay and peritoneal lavage cytology (PLC) examination in peritoneal lavage fluid for the prediction of peritoneal metastasis in gastric cancer patients, and to explore the relationship between telomerase activity and proliferating cell nuclear antigen expression., Methods: Telomeric repeated amplification protocol (TRAP)-enzyme-linked immunosorbent assay (ELISA) was performed to measure the telomerase activity in 60 patients with gastric cancer and 50 with peptic ulcer. PLC analysis of the 60 patients with gastric cancer was used for comparison. The proliferating cell nuclear antigen (PCNA) in gastric carcinoma was immunohistochemically examined., Results: The telomerase activity and PLC positive rate in peritoneal lavage fluid from patients with gastric cancer was 41.7% (25/60), and 25.0% (15/60), respectively. The positive rate of telomerase activity was significantly higher than that of PLC in the group of pT(4) (15/16 vs 9/16, P < 0.05), P(1-3) (13/13 vs 9/13, P < 0.05) and diffuse type (22/42 vs 13/42, P < 0.05). The patients with positive telomerase activity, peritoneal metastasis, and serosal invasion had significantly higher levels of average PCNA proliferation index (PI), (55.00 +/- 6.59 vs 27.43 +/- 7.72, 57.26 +/- 10.18 vs 29.15 +/- 8.31, and 49.82 +/- 6.74 vs 24.65 +/- 7.33, respectively, P < 0.05)., Conclusion: The TRAP assay for telomerase activity is a useful adjunct for cytologic method in the diagnosis of peritoneal micrometastasis and well related to higher proliferating activity of gastric cancer. The results of this study also suggest a promising future therapeutic strategy for treating peritoneal dissemination based on telomerase inhibition.

Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis Bb12 (Bb12) were assessed for their potential to prevent indomethacin-induced ulceration in the small intestine of Sprague-Dawley rats. Rats were gavaged skim milk, LGG, or Bb12 twice daily for 14 days. Between days 7-14, rats were gavaged indomethacin (Indo; 6 mg/kg). At sacrifice, small intestine was scored for ulceration and sampled for histologic, immunohistochemical, and myeloperoxidase (MPO) analyses. Indo+LGG-treated rats exhibited a 2.3-fold increase in MPO activity and a 9.8-fold increase in ulceration area compared to Indo-treated controls; these parameters did not differ significantly between Indo+Bb12 and Indo-treated controls. Crypt cell apoptosis decreased by 82% in Indo+Bb12-treated and 55% in Indo+LGG-treated rats compared to Indo-treated controls. Proliferation increased by 209% in Indo+LGG-treated animals compared to Indo-treated controls. Bb12 did not reduce indomethacin-induced intestinal ulceration, whereas LGG actually increased some indicators of injury. LGG and Bb12, at the doses tested, cannot alleviate indomethacin-induced intestinal injury.

Background: Telomerase is a ribonucleoprotein polymerase that is essential for cell immortality. Recent studies have demonstrated that a high percentage of gastric cancer tissue expressed telomerase. This study describes the presence of telomerase activity in gastric lavage fluid in patients with gastric cancer., Methods: Gastric lavage fluid was collected during esophageogastroduodenoscopy in 70 patients: 25 with gastric cancer, 25 with peptic ulcer disease, and 20 with normal stomach. The fluid and biopsy samples were analyzed for telomerase activity by a polymerase chain reaction-based telomerase repeat amplification protocol. The findings were related to the histological results., Results: Telomerase activity was present in 24 of the 25 (96%) gastric cancer tissue and in 7 of the 25 tissue specimens from peptic ulcer or gastritis. In the gastric lavage fluid, telomerase was detected in 20 patients (80%) with gastric cancer, 7 patients (28%) with peptic ulcer, and none in normal subjects (P < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of gastric fluid telomerase expression in gastric cancer patients was 80%, 84%, 74%, and 88%, respectively., Conclusions: The presence of telomerase activity is present in gastric lavage fluid of patients with gastric cancer as compared to those without, may represent a novel method for diagnosis of gastric cancer.

We studied the activity of whole ATPase, Mg2+ -ATPase and Na+, K+ -ATPase of peripheral blood erythrocytes in 68 patients with colorectal cancer before surgery and immediately after it and found such activity to be reduced. The low activity of Na+, K+ -ATPase of peripheral blood erythrocyte was shown as possible for use in prognosticating acute postoperative erosive-ulcerous lesions of the gastric tunic. Ozone therapy, if undertaken preoperatively, restores the ATPase activity.

Background/aims: In this study, we analysed the changes of matrix metalloproteinase-9 (MMP-9) expression in the gastric antral epithelium in respect to H. pylori eradication., Methods: Twenty patients with H. pylori-positive chronic gastritis or peptic ulcer were studied. The expression of MMP-9 in the gastric antral biopsy specimens were compared before and after H. pylori eradication using immunohistochemical study. The positive rates and intensity of MMP-9 staining were evaluated at surface mucous cells and pyloric gland cells., Results: The positive rate of MMP-9 staining in antral mucosal epithelial cells of H. pylori chronic gastritis is 63.8%. The positive rates of MMP-9 staining in the surface mucous cells and pyloric gland cells were 75.5% and 52.0% before H. pylori eradication, respectively. On the contrary, the rates were 85.5% and 82.0% after eradication. The MMP-9 overexpression in the pyloric gland cells were noticeably increased after H. pylori eradication. Strong positive staining of MMP-9 was increased significantly after H. pylori eradication in the pyloric gland cells., Conclusions: These results suggest that MMP-9 over-expression is associated with H. pylori infection as a host inflammatory response. The increased expression after H. pylori eradication indicates that MMP-9 may have a important role in remodeling or early tissue repairing process of gastric mucosa.

Objective: The aim of this pharmacogenomics study was to investigate the influence of different cytochrome P450 (CYP) genotypes in Helicobacter pylori eradication therapy., Method: The study involved 143 consecutive Italian Caucasian patients with H. pylori infection diagnosed and treated with 1-wk triple therapy according to European Helicobacter Pylori Study Group guidelines. Using human genomic DNA, CYP2C19 (*2 and *3) and CYP3A4 alleles (*1B, *2, and *3) were evaluated by polymerase chain reaction-restriction fragment length polymorphism assays and confirmed by sequencing the amplicons., Result: According to the endoscopy-based gold standard, 93 patients achieved H. pylori eradication. Regarding CYP2C19 genotype, the 50 patients who remained infected were all homozygous or heterozygous extensive metabolizers (homEM or hetEM). Carriers of homEM fared significantly less well than those of hetEM; homEM genotype was also predictive of failure at univariate/multivariate analysis. Carriers of CYP3A4 polymorphisms achieved favorable eradication rates similar to patients bearing CYP2C19. All four patients with single CYP3A4*2 polymorphism achieved eradication, and only 29% (5/17) of all CYP3A4*1B carriers did not achieve eradication. All nine patients carrying CYP3A4 polymorphisms in the CYP2C19 hetEM subgroup were cured, suggesting the possibility of a positive synergism between CYP3A4 and CYP2C19., Conclusions: This first pharmacogenomics study on the influence of different CYP genotypes on H. pylori therapy suggests that, as in Asian populations, CYP2C19 genotype patterns are probably also relevant in Caucasians receiving H. pylori eradication regimens that include omeprazole. The possibility of a favorable drug interaction mediated by CYP2C19 and CYP3A4 requires investigation.

Highly selective inhibitors of cyclooxygenase-2 (COX-2i) were introduced to minimize peptic ulcers and their complications caused by dual COX inhibitors (COXi). Co-prescribing a (generally cheap) dual COXi with a gastroprotectant is an alternative strategy, proven to reduce the incidence of NSAID-associated endoscopic ulcers. This review compares the efficacies of these two strategies and makes some estimates of their relative cost-effectiveness. In standard risk patients, endoscopic ulcers are reduced to about the same extent (around 70-80%) by either co-prescribing omeprazole or lansoprazole with a dual COXi or preferring a COX-2i alone. COX-2i reduced ulcer complications by a weighted mean of around 60% in comparative studies with dual COXi. There is little information about the influence of PPI on this endpoint, although one study using H. pylori treatment as a possible surrogate for placebo intervention found 77% protection against recurrent upper gastrointestinal bleeding by co-administered omeprazole. One direct comparison of the two strategies in high-risk patients (recent ulcer bleed) found quite high rates of re-presentation with bleeding ulcer using either strategy, and the differences between them were not significant. Drug costs in four Western countries were compared for each strategy. In one, the costs were similar, but in the others the combination of a cheap dual COXi with omeprazole was usually more expensive than using a COX-2i. The safest strategy in highest risk patients may be to co-prescribe a gastroprotectant with a COX-2i, with resulting higher drug costs but possibly offset by savings in other health costs. The efficacy and cost-benefit of this alternative approach warrants investigation.

The antisecretory and antiulcer effects of aqueous extract of Neem (Azadirachta indica) bark have been studied along with its mechanism of action, standardisation and safety evaluation. The extract can dose dependently inhibit pylorus-ligation and drug (mercaptomethylimidazole)-induced acid secretion with ED(50) value of 2.7 and 2 mg Kg(-1) b.w. respectively. It is highly potent in dose-dependently blocking gastric ulcer induced by restraint-cold stress and indomethacin with ED(50) value of 1.5 and 1.25 mg Kg(-1) b.w. respectively. When compared, bark extract is equipotent to ranitidine but more potent than omeprazole in inhibiting pylorus-ligation induced acid secretion. In a stress ulcer model, it is more effective than ranitidine but almost equipotent to omeprazole. Bark extract inhibits H(+)-K(+)-ATPase activity in vitro in a concentration dependent manner similar to omeprazole. It offers gastroprotection against stress ulcer by significantly preventing adhered mucus and endogenous glutathione depletion. It prevents oxidative damage of the gastric mucosa by significantly blocking lipid peroxidation and by scavenging the endogenous hydroxyl radical ((z.rad;)OH)-the major causative factor for ulcer. The (z.rad;)OH-mediated oxidative damage of human gastric mucosal DNA is also protected by the extract in vitro. Bark extract is more effective than melatonin, vitamin E, desferrioxamine and alpha-phenyl N-tert butylnitrone, the known antioxidants having antiulcer effect. Standardisation of the bioactive extract by high pressure liquid chromatography indicates that peak 1 of the chromatogram coincides with the major bioactive compound, a phenolic glycoside, isolated from the extract. The pharmacological effects of the bark extract are attributed to a phenolic glycoside which is apparently homogeneous by HPLC and which represents 10% of the raw bark extract. A single dose of 1g of raw extract per kg b.w. (mice) given in one day and application of 0.6g raw extract per kg b.w. per day by oral route over 15 days to a cumulative dose of 9g per kg was well tolerated and was below the LD(50). It is also well tolerated by rats with no significant adverse effect. It is concluded that Neem bark extract has therapeutic potential for the control of gastric hyperacidity and ulcer.

The development of mice deficient in either cyclooxygenase-1 (COX-1) or COX-2, as well as mice deficient in both COX isoforms, has provided models to elucidate the physiological and pathophysiological roles of these enzymes. The findings obtained with the COX-deficient mice suggest that COX-2 may be more important than COX-1 for supplying prostaglandins (PGs) to maintain tissue homeostasis. Furthermore, both isoforms may be involved in the development of diseases, such as inflammation and cancer. Therefore, the contribution of each isoform to the prevention or development of disease is more complex than originally described. Studies with the COX-deficient mice suggest that in addition to COX-2-selective inhibition, therapeutic advances may also be achieved with COX-1-selective inhibitors which lack gastrointestinal side effects.

Traditional assays of alcohol dehydrogenase (ADH) activity in gastric mucosa use spectrophotometry of tissue homogenates, which are based on the reduction of nicotinamide adenine dinucleotide (NAD). We describe a colorimetric method using the coupled reduction of N,N-dimethyl-4-nitrosoaniline. This method has increased sensitivity, allowing activity to readily be determined in standard endoscopic biopsies. Tissue homogenisation has been replaced by an incubation stage, and the method has been optimised for a 96-well plate reader, allowing rapid processing of large numbers of samples. We found that Helicobacter pylori infection and age have a significant effect on gastric ADH activity., (Copyright 2002 Elsevier Science B.V.)

Background and Aims: Genetic polymorphism of cytochrome P450 (CYP) 2C19 influences the efficacy of Helicobacter pylori eradication therapy with a proton pump inhibitor (PPI) and amoxicillin. However, in triple therapy (PPI plus amoxicillin and clarithromycin), little is known about the impact of CYP2C19 polymorphism, or the use of rabeprazole, which is not well metabolized by CYP2C19. The efficacy of three PPI (omeprazole, lansoprazole, and rabeprazole) in a 1-week triple regimen were compared in relation to CYP2C19 polymorphism., Method: One hundred and eighty-three patients were randomized to receive one of the following regimens: amoxicillin 500 mg t.i.d., clarithromycin 200 mg t.i.d., and PPI (omeprazole 20 mg, lansoprazole 30 mg, or rabeprazole 10 mg) b.i.d. CYP2C19 polymorphism was analyzed by PCR restriction fragment length polymorphism., Results: Intention-to-treat-based overall cure rates for omeprazole, lansoprazole or rabeprazole regimens were 83.1% (95% confidence interval (CI): 69-89%), 86.7% (CI: 75-93%), and 76.6% (CI: 64-85%), respectively, without significant difference. The cure rate of the rabeprazole regimen (but not the lansoprazole or omeprazole regimens) tended to be correlated with CYP2C19 genotypes (P = 0.076). In patients with a homozygous extensive metabolizer genotype, the per protocol-based cure rate with rabeprazole (62.5%) was significantly lower than that with lansoprazole (90.0%; P = 0.038)., Conclusion: The overall cure rate of 1-week triple therapy for H. pylori eradication was not significantly different between regimens with omeprazole, lansoprazole or rabeprazole, but the impact of CYP2C19 genetic polymorphism on the cure rate appeared to differ between these PPI., (Copyright 2002 Blackwell Publishing Asia Pty Ltd)

Background: Our previous study showed that histological scores of gastric mucosal inflammation and Helicobacter pylori density decreased even in patients who failed to eradicate Helicobacter pylori after antimicrobial therapy including clarithromycin. This may reflect indirect suppressive effects of lower concentrations of clarithromycin on Helicobacter pylori, as suggested in other Gram-negative rod infections., Aims: To investigate whether clarithromycin suppresses virulence factors of Helicobacter pylori at sub-minimal inhibitory concentration., Methods: Six clarithromycin-susceptible Helicobacter pylori isolates and 7 clarithromycin-resistant isolates were obtained from patients with peptic ulcer disease. These isolates were analysed for urease activity, motility, and ability to bind to gastric epithelial cells after they were incubated with or without clarithromycin at sub-minimal inhibitory concentrations., Results: Incubation of Helicobacter pylori isolates with clarithromycin at sub-minimal inhibitory concentrations reduced urease activity motility, and binding to gastric epithelial cells in a dose-dependent manner. These findings were observed both in clarithromycin-susceptible and resistant strains., Conclusions: Suppressive effects of clerithromycin on virulence factors of Helicobacter pylori at sub-minimal inhibitory concentrations may be associated with observed attenuation of gastric inflammation and Helicobacter pylori density in patients who failed in bacterial eradication after triple therapy including clarithromycin.

The study was conducted to examine the role of free radicals in Indomethacin induced gastric mucosal injury and to evaluate the gastroprotective effects of melatonin and beta-carotene. Gastric mucosal injury was produced in rats by administering indomethacin 30 mg/kg subcutaneously. Melatonin was administered in three different doses of 5, 10 and 20 mg/kg, 30 minutes prior to the administration of indomethacin. Beta-carotene was administered as a single dose of 100 mg/kg. Following parameters were calculated: ulcer index, lipid peroxidation and antioxidant defense enzymes i.e. superoxide dismutase, glutathione peroxidase and catalase. Indomethacin caused gastric mucosal injury in the form of haemorrhages, increased the lipid peroxidation and decreased the levels of the antioxidant defense enzymes. Melatonin (20 mg/kg) and beta-carotene decreased the ulcer index and lipid peroxidation, and reduced the decrease in antioxidant enzyme levels. These findings suggest the melatonin and beta-carotene show protective effect against indomethacin induced gastric injury and this effect is mediated by scavenging of oxygen derived free radicals.

We investigated the role of xanthine oxidase-derived oxygen radicals in the development of endothelin-1-induced gastric ulcer. Mucosal lipid peroxidation showed a peak 24 h after injection, while gastric mucosal haemodynamics were fully restored 26 h after endothelin-1 injection. Allopurinol and oxypurinol, but not superoxide dismutase or catalase, protected the gastric mucosa 24 h after endothelin-1 injection. Oxypurinol antagonized both the vasoconstrictor effect of endothelin-1 and the decrease in gastric ATP. All treatments on the second day after endothelin-1 injection significantly reduced gastric mucosal damage. Xanthine oxidase-derived oxygen radicals contributed largely to the exacerbation but they did not mediate the onset of endothelin-1-induced gastric ulcer. Pretreatment with probucol (500 mg/kg, p.o.) also protected the gastric mucosa from endothelin-1-induced mucosal injury by its antioxidant activity. Oxypurinol was gastroprotective through its vasoactive and energy saving actions. The haemodynamic background of endothelin-1-induced gastric ulcer consists of long lasting ischaemia and subsequent "reperfusion" which may be responsible for the late burst of oxygen radicals.

Teprenone, an anti-ulcer drug, has been reported to promote the healing of acetic acid-induced chronic gastric ulcers in rats by stimulating gastric mucus synthesis and secretion. Recently, it has been implicated that neutrophil infiltration and lipid peroxidation in ulcerated gastric tissues have an inhibitory effect on the healing of acetic acid-induced chronic gastric ulcers in rats. Therefore, we attempted to clarify whether teprenone exerts a healing-promoting effect on acetic acid-induced chronic gastric ulcers through its inhibitory effect on neutrophil infiltration and lipid peroxidation in ulcerated gastric tissues. In rats with chronic gastric ulcers made by applying acetic acid to the stomach, gastric ulcer healing started later than 3 days after the acetic acid application. Gastric mucosal myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration, and lipid peroxide content were higher in the ulcerated region than in the intact region on the 8th, 15th, and 22nd day after the acetic acid application. Gastric mucosal non-protein SH content was lower in the ulcerated region than in the intact region on the 8th, 15th, and 22nd day after the acetic acid application, and gastric mucosal adherent mucus content was lower in the ulcerated region than in the intact region on the 8th and 15th day. Daily oral administration of teprenone (100 mg kg(-1)x 2) for 7 or 14 days, starting on the 8th day after the application of acetic acid to the stomach, enhanced the reduction of the ulcer area with attenuation of all these biochemical changes found in the ulcerated region. The teprenone administration caused a decrease in MPO activity and an increase in adherent mucus content in the gastric mucosa of the intact region. These results suggest that the healing-promoting effect of teprenone on acetic acid-induced chronic gastric ulcers in rats could be due not only to stimulation of gastric mucus secretion but also to inhibition of neutrophil infiltration and enhanced lipid peroxidation in the ulcerated gastric tissue., (Copyright 2001 Academic Press.)

Inhibition of prostaglandin biosynthesis via inhibition of the fatty acid cyclooxygenase (COX) is the mechanism of action of non-steroidal anti-inflammatory drugs (NSAIDs). This results in an inhibition of the inflammatory and pain-producing activities of prostaglandins at a site of tissue injury but also in inhibition of prostaglandin production in the gastrointestinal tract (GI) and platelets, i.e. sites where endogenous prostaglandins are possibly involved in control of physiological functions. The discovery of two COX isoenzymes, COX-1 and COX-2, and the detection of their separate function and regulation, has initiated the search for new and putatively more selective inhibitors of prostaglandin biosynthesis. Specifically, selective inhibitors of COX-2 were developed in order to improve the anti-inflammatory and analgetic specificity and potency of the compounds and to reduce side-effects in the GI tract. Available experimental and clinical data of selective COX-2 inhibitors, including flosulide, celecoxib or rofecoxib, suggest improved gastric tolerance as compared to conventional, non-selective NSAIDs. However, experimental evidence suggests that both, the analgetic and anti-inflammatory action of COX-inhibitors, might also require inhibition of COX-1. COX-2-selective compounds at anti-inflammatory doses might have other side-effects, and for example reduce vascular prostacyclin production. Evidence is accumulating that COX-2 might not only be considered as a putatively detrimental enzyme but rather a highly regulated enzyme that also contributes to tissue protection and is even constitutively expressed in healthy human stomach mucosa. This paper reviews some of these newer aspects of COX-2-selective inhibitors in clinical use and discusses their possible benefits and risks.

Human gastric mucosa contains aspartic proteinases that can be separated electrophoretically on the basis of their physical properties into two major groups: Pepsinogen I (PGA, PGI); and Pepsinogen II (PGC, PGII). Pepsinogens consist of a single polypeptide chain with molecular weight of approximately 42,000 Da. Pepsinogens are mainly synthesized and secreted by the gastric chief cells of the human stomach before being converted into the proteolytic enzyme pepsin, which is crucial for the digestive processes in the stomach. Pepsinogen synthesis and secretion are regulated by positive and negative feed-back mechanisms. In the resting state pepsinogens are stored in granules, which inhibit further synthesis. After appropriate physiological or external chemical stimuli, pepsinogens are secreted in the stomach lumen where hydrochloric acid, secreted by the parietal cells, converts them into the corresponding active enzyme pepsins. The stimulus-secreting coupling mechanisms of pepsinogens appear to include at least two major pathways: one involving cAMP as a mediator, the other involving modification of intracellular Ca(2+)concentration. Physiological or external chemical stimuli acting through the intracellular metabolic adenyl cyclase are more effective in inducing ' de novo ' pepsinogen synthesis than those acting through intracellular Ca(2+). The activation of protein kinase C (PK-C) would appear to be involved in regulatory processes. The measurement of pepsinogens A and C in the serum is considered to be one of the non-invasive biochemical markers for monitoring peptic secretion and obtaining information on the gastric mucosa status of healthy subjects. Recently, pepsinogen measurements have been used as an effective biochemical method for evaluating and monitoring patients with gastrointestinal diseases and for checking the effects of drug treatment. The level of PGA in the serum is always high in normal gastritis, while in atrophic gastritis it is always low. In both cases the PGC level in the serum is high. In most gastrointestinal pathologies the ratio between the PGA/PGC decreases. Various reports concerning hormone and/or enzyme modification as well as gastrointestinal distress in the case of long distance exercise have been reported. It has been suggested that the origin of the gastrointestinal distress experienced by long distance runners is a transient ischaemia of the gastric mucosa; it is also suggested that a hypobaric-hypoxic environment could contribute to induce gastric mucosa necrosis. Interrelation between gastrointestinal distress, hypobaric-hypoxic environment and modifications of PGA and PGC, gastrin and cortisol was evaluated in 13 athletes after a marathon performed at 4300 m. Gastrointestinal symptoms occurred in approximately 40% of the athletes. After the race the athletes showed a significant increase of gastrin and cortisol, while the ratio between PGA/PGC decreased. No relationship was observed between gastrointestinal symptoms and hormonal changes after the race. A control group of five subjects, who had been exposed to the same environmental conditions, showed no gastrointestinal or hormonal alteration. Conversely, control subjects presented a significant decrease of cortisol related to the circadian rhythm. The same incidence of gastrointestinal symptoms at high altitude and at sea level and the absence of pathological alteration of PGA and PGC in the serum of the athletes indicates that running a marathon and living for 6 days at 4300 m does not induce gastric mucosa necrosis. Cortisol and gastrin alteration observed in the athletes at this altitude would seem to be related to an activation of the mesopontine and forebrain structures involved in the behavioural and metabolic integration of the autonomic control and arousal and psychophysical-exercise stress. 2000 Academic Press@p$hr, (Copyright 2000 Academic Press.)

Peptidase systems of all the layers of the jejunum and ileum proved to be most sensitive to stress in young rats, whereas in mature and old rats the peptidases' activity was enhanced, particularly in subepithelial layers of the ileum and jejunum. This may be regarded as an adaptive-compensatory response to probable existence of unsplit low-molecular peptides in the subepithelial space due to an augmentation of proteins catabolism and their inflow via stress-damaged membranes of enterocytes.

Pain management long has been an important consideration in dental care. Nonopioid analgesics such as aspirin, acetaminophen, and many of the nonsteroidal anti-inflammatory drugs (NSAIDs) generally provide predictable outcomes for control of dental pain because of their analgesic and anti-inflammatory properties. The anti-inflammatory action of NSAIDs also is being investigated in treatment of periodontal disease when used as an adjunct to non-surgical management. Since NSAID use by dental patients is high, gastrointestinal complications may arise, affecting long-term use of these agents. Systemic considerations of NSAID use are reviewed, as are complications frequently resulting in ulceration of the gastric mucosa.

The role of nitric oxide in ulcer formation remains unknown. Accordingly, we assessed local expression of inducible nitric oxide synthase (NOS) and nitration of tyrosine as an indicator of peroxynitrite formation in patients with Helicobacter pylori (HP)-associated gastric ulcers compared with HP-negative ulcers. Biopsy specimens were taken from the ulcer margin and from an area remote from the ulcer portion. Inducible NOS, nitrotyrosine, and macrophage immunoreactivity were assessed immunohistochemically using a labeled streptavidin-biotin method. In HP-positive gastric ulcers, inducible NOS and nitrotyrosine immunoreactivity was frequently observed at active ulcer margins, sometimes in surface epithelial cells as well as in the lamina propria. Occasionally, inducible NOS and nitrotyrosine reactivity were found in areas remote from the lesion in cases of HP-positive ulcer and HP-related gastritis. Macrophages accumulated significantly in the margin of HP-positive ulcers. In HP-negative gastric ulcers, inducible NOS and nitrotyrosine immunoreactivity also were frequent at the ulcer margin, but no significant immunoreactivity was observed at a distance. HP eradication caused significant attenuation in inducible NOS and macrophage immunoreactivity. In conclusion, nitric oxide and peroxynitrite formation is increased in HP-infected gastric mucosa, suggesting that HP promotes nitric oxide stress.

Background: Overproduction of nitric oxide (NO) has been implicated in the pathogenesis of experimental and clinical inflammatory bowel disease (IBD)., Methods: We observed the expression and localization of inducible NO synthase (NOS-II) in small intestinal ulceration induced by indomethacin in rats. The role of NO was investigated by using NO synthase inhibitors., Results: The small intestine was affected by longitudinal ulcers after indomethacin administration and ulceration was associated with distinctive expression of NOS-II protein and mRNA. The amount of its expression was found to correlate with the extent of inflammation. Histologically, both immunohistochemistry and in situ hybridization revealed a similar localization of NOS-II to inflammatory and epithelial cells. The possible amelioration of the inflammation was modulated by aminoguanidine (AG) and NG-nitro-L-arginine methyl ester (L-NAME) treatment for 10 days. Both AG and L-NAME attenuated intestinal myeloperoxidase activity and gross inflammation, only AG was found to decrease intestinal permeability with a significant amelioration of body weight loss., Conclusion: These findings indicate that NO derived mainly from inflammatory cells may play an important role in the pathophysiology of intestinal ulceration and offer the potential for future treatment directed at blocking neutrophils recruitment and NO overproduction in IBD.

Background: The S-mephenytoin hydroxylase is a polymorphic cytochrome P450 (CYP) enzyme, identified as CYP2C19, which catalyses the metabolism of omeprazole and some other drugs., Aim: To determine whether long-term treatment with omeprazole affects serum vitamin B12 levels, and if so to what extent it depends on CYP2C19 activity., Methods: Serum vitamin B12 levels (pmol/L) were assessed in 179 patients. Genotyping for wild-type (wt) and mutated (mut) CYP2C19 alleles was performed by allele-specific PCR amplification., Results: One-hundred and eleven of the patients received one dose of 20 mg omeprazole. No difference in B12 levels were found between heterozygous (wt/mut) (n = 23) and homozygous (wt/wt) (n = 85) patients (mean +/- s.d., 350 +/- 82 vs. 315 +/- 87 pmol/L, respectively). Three patients were mut/mut, with serum vitamin B12 levels of 303 +/- 50 pmol/L. In the 68 patients on long-term (>1 year) therapy with 20 mg omeprazole daily, serum vitamin B12 levels were lower in the heterozygous (wt/mut) (n = 19) compared to homozygous wt/wt (n = 49) (246 +/- 71 vs. 305 +/- 98 pmol/L, P = 0. 01, respectively). In one patient (mut/mut) who was studied both after a single dose and after long-term (15 months) treatment with omeprazole, serum vitamin B12 decreased from 360 to 178 pmol/L. In the wt/mut, but not in the wt/wt group, serum vitamin B12 levels were significantly lower in patients on long-term therapy compared with those receiving one dose (246 +/- 71 vs. 350 +/- 82 pmol/L, P < 0.0001, respectively)., Conclusions: CYP2C19 polymorphism significantly affected serum vitamin B12 levels in patients on long-term therapy with omeprazole. In the future, genotyping of CYP2C19 may be useful for patients in need of long-term treatment with omeprazole or other proton pump inhibitors.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used in the treatment of arthritis and pain. These drugs tend to cause significant side effects, however, including gastric and intestinal toxicity. The mechanism of action of NSAIDs is through their inhibition of the key enzyme of prostaglandin biosynthesis, the cyclooxygenase. Recently, two forms of cyclooxygenase have been found to exist: COX-1 and COX-2, the constitutive and inducible forms, respectively. COX-1 exists in the stomach, intestine, kidneys and platelets, while COX-2, the inducible form, is expressed during inflammation. The therapeutic effects of NSAIDs are largely the result of inhibition of the enzyme cyclooxygenase-2 (COX-2), whereas the toxic effects (e.g., gastrointestinal, renal and platelet effects) are primarily due to the inhibition of COX-1. Individual NSAIDs show different potencies against COX-1 compared with COX-2 and this explains the variations in the side effects of NSAIDs at their anti-inflammatory doses. Drugs with high potency against COX-2 and a better COX-2-/COX-1 activity ratio will have anti-inflammatory activity with fewer gastrointestinal side effects. In contrast piroxicam and indomethacin, which drugs have a much higher potency against COX-1 than against COX-2, are amongst those with the highest gastrointestinal toxicity. Based on these findings, COX-2 seems to be an ideal target for the development of new anti-inflammatory drugs. Several compounds with preferential or specific COX-2 inhibiting properties have been synthesized and evaluated in pre-clinical and clinical studies i.e. Meloxicam, Celecoxib, MK-966, Flusolid and L-745, 337. The COX-2 selectivity of these novel NSAIDs relate well to their favorable gastrointestinal tolerability profile. Clinical trials have shown meloxicam and celecoxib to be as effective as currently available NSAIDs, but with an improved gastrointestinal tolerability profile. Further clinical trials and large-scale postmarketing surveillance programs are needed, however, to confirm the potential therapeutic benefits of these novel preferential or specific COX-2 inhibitors.

Activated neutrophils play an important role in tissue injury by releasing various inflammatory mediators capable of damaging endothelial cells. To investigate whether neutrophil elastase (NE) is involved in stress-induced gastric mucosal injury, we examined the effects of 2 NE inhibitors (ONO-5046 and L-658 758) as well as nitrogen mustard-induced leukocytopenia on the formation of gastric mucosal lesions, gastric mucosal blood flow, gastric mucosal microvascular permeability, and gastric neutrophil accumulation in rats subjected to water immersion-restraint stress (WIR). Gastric mucosal injury peaked 8 hours after WIR. Gastric mucosal blood flow, as measured by laser-Doppler flow cytometry, decreased to 45% of its initial level 8 hours after WIR. Gastric mucosal microvascular permeability, evaluated by Evans blue dye leakage to the gastric mucosa, showed an increase, peaking 8 hours after WIR. Gastric accumulation of neutrophils, determined by measuring gastric myeloperoxidase activity and by histologic examination, was also significantly increased 8 hours after WIR. Both of the NE inhibitors markedly prevented the formation of gastric mucosal lesions. They also decreased the reduction in gastric mucosal blood flow seen in animals subjected to WIR while preventing increases in gastric mucosal microvascular permeability. Gastric neutrophil accumulation was significantly reduced in animals given either inhibitor 8 hours after WIR. Leukocytopenia produced effects similar to those produced by the inhibitors. Taken together, these observations strongly suggest that NE promotes stress-induced gastric mucosal injury in rats by reducing gastric mucosal blood flow and increasing neutrophil accumulation.

Background: Omeprazole is to a major extent metabolized by cytochrome P450 isozyme CYP2C19. The aims of this study were to compare the phenotype of CYP2C19 determined by omeprazole with the genotype and to determine the effect of Helicobacter pylori infection on the metabolism of omeprazole., Methods: One-hundred and forty-three Caucasian patients with acid-related disorders assessed with a combination of gastrointestinal symptoms and upper endoscopic findings were given 20 mg omeprazole orally. Three hours after intake, omeprazole and 5-hydroxyomeprazole plasma concentrations were determined with high-performance liquid chromatography, and the phenotype for metabolic capacity was expressed as metabolic ratio (MR). Genotyping of defect alleles (CYP2C19*2 and *3) was performed by polymerase chain reaction amplification. One hundred eleven patients were tested after the first dose of omeprazole and 32 patients after repetitive administration (median time, 30 days). H. pylori serology was determined with enzyme-linked immunosorbent assay at the time of phenotyping., Results: Genotypically, 2.8% had two mutated alleles and were poor metabolizers (PM), and 22.4% were heterozygous extensive metabolizers (EM). Among the 111 patients who received the first omeprazole dose, 4 patients had MR >5--that is, belonged to the PM phenotype. Two of these had PM genotype (both CYP2C19*2/*2), and two had an EM genotype (CYP2C19*11*1 and *1/*3), indicating that they have still unidentified mutations. In the heterozygous EM group the mean MR was higher in patients who had been on continued omeprazole treatment than in those given the first dose (5.7 versus 2.5, P = 0.02). There were no significant differences in MR and omeprazole concentrations between H. pylori-negative (43%) and -positive (57%) patients., Conclusion: In all but two patients with probable unidentified mutations there was agreement between the CYP2C19 phenotype determined by omeprazole and the genotype. The metabolism of omeprazole in patients with acid-related disorders is genetically determined and without relation to H. pylori infection.

The gastric juice of Helicobacter pylori-infected individuals contains substantially higher levels of phospholipase A2 (PLA2) than that of individuals who are not infected. We present a new theory for how this H. pylori-induced PLA2 activity in gastric juice may play a major role in the development of peptic ulcer disease. When activated at neutral pH (pH 6.5-7.0), PLA2 may damage the surfactant-like, phospholipid-rich layer which constitutes an important part of the mucus barrier. Pepsin and other proteases, activated at low pH (pH 1.0-3.5), may then denature and cleave PLA2-exposed proteins. Peptic ulcers therefore tend to develop in regions exposed to changing luminal pH, such as the duodenal bulb when acid production is high or normal, or in the stomach when acid secretion is low.

To investigate the changes in serum anti-Helicobacter pylori IgG antibody (HP Ab), pepsinogen I (PG I), pepsinogen II (PG II), and pepsinogen I/II ratio (PG I/II) after eradication therapy of Helicobacter pylori (HP), we studied 78 patients with HP-positive peptic diseases. They received combination therapy (proton pump inhibitor + amoxicillin: n = 17, proton pump inhibitor + amoxicillin + clarithromycin: n = 61). In the 68 patients in whom HP was eradicated, HP Ab, PG I, and PG II decreased and PG I/II increased significantly after eradication. Especially, the decrease in PG II and the increase in PG I/II were rapid and remarkable, found 2 months after the beginning of eradication therapy, and then continued. On the other hand, in the patients in whom HP was not eradicated, HP Ab and PG I/II did not change significantly, while PG I and PG II temporarily increased at the end of administration of proton pump inhibitor. In conclusion, it seems that the measurement of PG II and PG I/II is useful for the early detection of HP eradication.

Saliva contains several factors that protect the alimentary canal mucosa against acidity. We measured the secretory carbonic anhydrase (CA VI) levels in the saliva of patients with gastrointestinal disorders using a time-resolved immunofluorometric assay. The mean enzyme concentrations were found to be lower in patients with verified esophagitis, gastric ulcer, or duodenal ulcer than in control patients with nonacid peptic diseases. The biochemical data from the enzyme activity assays and western blots of the human gastric mucosa and gastric juice samples indicated that the swallowed CA VI probably retains its activity in the harsh environment of the gastric lumen. In the upper alimentary canal, CA VI may neutralize the acid by catalyzing the formation of carbon dioxide and water. The present findings suggest that drugs supplemented with CA VI may prove beneficial in treating acid-peptic diseases.

The role of sialic acid for the adhesion of Helicobacter pylori to gastric mucosa cells and/or to the mucin layer is still under debate. Several but not all H. pylori strains express a sialic acid-binding adhesin, specific for terminal alpha-2,3-sialic acid residues. Recently, the production of sialidase by H. pylori was reported [Dwarakanath, A.D. et al. (1995) FEMS Immunol. Med. Microbiol. 12,213 216]. We analysed several strains isolated from gastric biopsies cultivated both in liquid media and on agar plates for sialidase. Activity of this enzyme was first assayed using the fluorigenic substrate 4-methylumbelliferyl-alpha-D-N-acetylneuraminic acid. Since the fluorimetric assay can give false-positive results caused by non-specific interactions with umbelliferyl-tagged substances, we used also the more sensitive and specific assay with sialyl-[3H]lactitol as a substrate. No evidence for sialidase activity of H. pylori strains, cultivated under both inducible and non-inducible conditions, was obtained.