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Sample records for acidic gastric environment

  1. [Gastric Acid].

    PubMed

    Ruíz Chávez, R

    1996-01-01

    Gastric acid, a product of parietal cells secretion, full fills multiple biological roles which are absolutely necessary to keep corporal homeostasis. The production of the acid depends upon an effector cellular process represented in the first step by histamine, acetilcholine and gastrin, first messengers of the process. These interact with specific receptors than in sequence activate second messengers -cAMP and the calcium-calmodulin system- which afterwards activate a kinase. An specific protein is then phosphorilated by this enzyme, being the crucial factor that starts the production of acid. Finally, a proton bomb, extrudes the acid towards the gastric lumen. The secretion process mentioned above, is progressive lyactivated in three steps, two of which are stimulators -cephalic and gastric phases- and the other one inhibitor or intestinal phase. These stages are started by mental and neurological phenomena -thought, sight, smell or memory-; by food, drugs or other ingested substances; and by products of digestion. Changes in regulation of acid secretion, in the structure of gastro-duodenal mucosal barrier by a wide spectrum of factors and agents including food, drugs and H. pylori, are the basis of acid-peptic disease, entity in which gastric acid plays a fundamental role. From the therapeutic point of view, so at the theoretical as at the practical levels, t is possible to interfere with the secretion of acid by neutralization of some of the steps of the effector cellular process. An adequate knowledge of the basics related to gastric acid, allows to create strategies for the clinical handling of associated pathology, specifically in relation to peptic acid disease in all of the known clinical forms. PMID:12165790

  2. A gastric acid secretion model.

    PubMed Central

    de Beus, A M; Fabry, T L; Lacker, H M

    1993-01-01

    A theory of gastric acid production and self-protection is formulated mathematically and examined for clinical and experimental correlations, implications, and predictions using analytic and numerical techniques. In our model, gastric acid secretion in the stomach, as represented by an archetypal gastron, consists of two chambers, circulatory and luminal, connected by two different regions of ion exchange. The capillary circulation of the gastric mucosa is arranged in arterial-venous arcades which pass from the gastric glands up to the surface epithelial lining of the lumen; therefore the upstream region of the capillary chamber communicates with oxyntic cells, while the downstream region communicates with epithelial cells. Both cell types abut the gastric lumen. Ion currents across the upstream region are calculated from a steady-state oxyntic cell model with active ion transport, while the downstream ion fluxes are (facilitated) diffusion driven or secondarily active. Water transport is considered iso-osmotic. The steady-state model is solved in closed form for low gastric lumen pH. A wide variety of previously performed static and dynamic experiments on ion and CO2 transport in the gastric lumen and gastric blood supply are for the first time correlated with each other for an (at least) semiquantitative test of current concepts of gastric acid secretion and for the purpose of model verification. Agreement with the data is reported with a few outstanding and instructive exceptions. Model predictions and implications are also discussed. Images FIGURE 1 PMID:8396457

  3. Ghrelin and gastric acid secretion

    PubMed Central

    Yakabi, Koji; Kawashima, Junichi; Kato, Shingo

    2008-01-01

    Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-induced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric acid secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion. PMID:19009648

  4. Effect of gastric acid suppressants on human gastric motility

    PubMed Central

    Parkman, H; Urbain, J; Knight, L; Brown, K; Trate, D; Miller, M; Maurer, A; Fisher, R

    1998-01-01

    Background—The effect of histamine H2 receptor antagonists on gastric emptying is controversial. 
Aims—To determine the effects of ranitidine, famotidine, and omeprazole on gastric motility and emptying. 
Patients and methods—Fifteen normal subjects underwent simultaneous antroduodenal manometry, electrogastrography (EGG), and gastric emptying with dynamic antral scintigraphy (DAS). After 30 minutes of fasting manometry and EGG recording, subjects received either intravenous saline, ranitidine, or famotidine, followed by another 30 minutes recording and then three hours of postprandial recording after ingestion of a radiolabelled meal. Images were obtained every 10-15 minutes for three hours to measure gastric emptying and assess antral contractility. Similar testing was performed after omeprazole 20 mg daily for one week. 
Results—Fasting antral phase III migrating motor complexes (MMCs) were more common after ranitidine (9/15 subjects, 60%), famotidine (12/15, 80%), and omeprazole (8/12, 67%) compared with placebo (4/14, 29%; p<0.05). Postprandially, ranitidine, famotidine, and omeprazole slowed gastric emptying, increased the amplitude of DAS contractions, increased the EGG power, and increased the antral manometric motility index. 
Conclusions—Suppression of gastric acid secretion with therapeutic doses of gastric acid suppressants is associated with delayed gastric emptying but increased antral motility. 

 Keywords: gastric motility; gastric emptying; histamine H2 receptor antagonists; proton pump inhibitors; gastric acid secretion; scintigraphy PMID:9536950

  5. Human Gastric Epithelial Cells Contribute to Gastric Immune Regulation by Providing Retinoic Acid to Dendritic Cells

    PubMed Central

    Bimczok, Diane; Kao, John Y.; Zhang, Min; Cochrun, Steven; Mannon, Peter; Peter, Shajan; Wilcox, Charles M.; Mönkemüller, Klaus E.; Harris, Paul R.; Grams, Jayleen M.; Stahl, Richard D.; Smith, Phillip D.; Smythies, Lesley E.

    2014-01-01

    Despite the high prevalence of chronic gastritis caused by H. pylori, the gastric mucosa has received little investigative attention as a unique immune environment. Here, we analyzed whether retinoic acid (RA), an important homeostatic factor in the small intestinal mucosa, also contributes to gastric immune regulation. We report that human gastric tissue contains high levels of the RA precursor molecule, retinol, and that gastric epithelial cells express both RA biosynthesis genes and RA response genes, indicative of active RA biosynthesis. Moreover, primary gastric epithelial cells cultured in the presence of retinol synthesized RA in vitro and induced RA biosynthesis in co-cultured monocytes through an RA-dependent mechanism, suggesting that gastric epithelial cells may also confer the ability to generate RA on gastric DCs. Indeed, DCs purified from gastric mucosa had similar levels of aldehyde dehydrogenase activity and RA biosynthesis gene expression as small intestinal DCs, although gastric DCs lacked CD103. In H. pylori-infected gastric mucosa, gastric RA biosynthesis gene expression was severely disrupted, which may lead to reduced RA signaling and thus contribute to disease progression. Collectively, our results support a critical role for RA in human gastric immune regulation. PMID:25249167

  6. Pharmacology of gastric acid inhibition.

    PubMed

    Shamburek, R D; Schubert, M L

    1993-03-01

    Gastric acid secretion is precisely regulated by neural (acetylcholine), hormonal (gastrin), and paracrine (histamine; somatostatin) mechanisms. The stimulatory effect of acetylcholine and gastrin is mediated via increase in cytosolic calcium, whereas that of histamine is mediated via activation of adenylate cyclase and generation of cAMP. Potentiation between histamine and either gastrin or acetylcholine may reflect postreceptor interaction between the distinct pathways and/or the ability of gastrin and acetylcholine to release histamine from mucosal ECL cells. The prime inhibitor of acid secretion is somatostatin. Its inhibitory paracrine effect is mediated predominantly by receptors coupled via guanine nucleotide binding proteins to inhibition of adenylate cyclase activity. All the pathways converge on and modulate the activity of the luminal enzyme, H+,K(+)-ATPase, the proton pump of the parietal cell. Precise information on the mechanisms involved in gastric acid secretion and the identification of specific receptor subtypes has led to the development of potent drugs capable of inhibiting acid secretion. These include competitive antagonists that interact with stimulatory receptors (e.g. muscarinic M1-receptor antagonists and histamine H2-receptor antagonists) as well as non-competitive inhibitors of H+,K(+)-ATPase (e.g. omeprazole). The histamine H2-receptor antagonists (cimetidine, ranitidine, famotidine, nizatidine and roxatidine acetate) continue as first-line therapy for peptic ulcer disease and are effective in preventing relapse. Although they are generally well tolerated, histamine H2-receptor antagonists may cause untoward CNS, cardiac and endocrine effects, as well as interfering with the absorption, metabolism and elimination of various drugs. The dominance of the histamine H2-receptor antagonists is now being challenged by omeprazole. Omeprazole reaches the parietal cell via the bloodstream, diffuses through the cytoplasm and becomes activated and

  7. Polyamines are Inhibitors of Gastric Acid Secretion

    NASA Astrophysics Data System (ADS)

    Ray, Tushar K.; Nandi, Jyotirmoy; Pidhorodeckyj, Nykolai; Meng-Ai, Zhou

    1982-03-01

    The naturally occurring organic polycations such as spermine and spermidine inhibit histamine-stimulated gastric acid secretion by bullfrog gastric mucosa in vitro; spermine is much more potent than spermidine. Unlike the H2 receptor antagonists, the polyamines are completely ineffective from the nutrient side and are effective only from the secretory side of the chambered mucosa. The polyamine effects could be reversed by increasing K+ concentration in the secretory solution. Studies with isolated gastric microsomal vesicles demonstrate that the polyamines do not inhibit the gastric H+,K+-ATPase but greatly decrease the ATPase-mediated uptake of H+ under appropriate conditions. For the latter effects the presence of polyamine within the vesicle interior was found to be essential. Our data strongly suggest an uncoupling of the gastric H+,K+-ATPase system by the polyamines. The therapeutic potential of these and similar compounds in the treatment of hyperacidity and peptic ulcer is discussed.

  8. Helicobacter pylori modulation of gastric acid.

    PubMed Central

    Calam, J.

    1999-01-01

    Helicobacter pylori plays major causative roles in peptic ulcer disease and gastric cancer. Elevated acid secretion in patients with duodenal ulcers (DUs) contributes to duodenal injury, and diminished acid secretion in patients with gastric cancer allows carcinogen-producing bacteria to colonize the stomach. Eradication of H. pylori normalizes acid secretion both in hyper-secreting DU patients and hypo-secreting relatives of gastric cancer patients. Therefore, we and others have asked how H. pylori causes these disparate changes in acid secretion. H. pylori gastritis more or less restricted to the gastric antrum in DU patients is associated with increased acid secretion. This is probably because gastritis increases release of the antral acid-stimulating hormone gastrin and diminished mucosal expression of the inhibitory peptide somatostatin. Bacterial products and inflammatory cytokines including TNFalpha may cause these changes in endocrine function. Gastritis involving the gastric corpus tends to diminish acid secretion, probably because bacterial products and cytokines including IL-1 inhibit parietal cells. Pharmacological inhibition of acid secretion increases corpus gastritis in H. pylori-infected subjects, so it is envisaged that gastric hypo-secretion of any cause might become self-perpetuating. H. pylori-associated mucosal atrophy will also contribute to acid hypo-secretion and is more likely in when the diet is high in salt or lacking in antioxidant vitamins. Data on gastric acid secretion in patients with esophagitis are limited but suggest that acid secretion is normal or slightly diminished. Nevertheless, H. pylori infection may be relevant to the management of esophagitis because: (i) H. pylori infection increases the pH-elevating effect of acid inhibiting drugs; (ii) proton pump inhibitors may increase the tendency of H. pylori to cause atrophic gastritis; and (iii) successful eradication of H. pylori is reported to increase the likelihood of

  9. Relation between gastric acid output, Helicobacter pylori, and gastric metaplasia in the duodenal bulb.

    PubMed Central

    Harris, A W; Gummett, P A; Walker, M M; Misiewicz, J J; Baron, J H

    1996-01-01

    BACKGROUND: Factors that determine gastric metaplasia in the duodenal bulb are ill defined. It is more common and extensive in the presence of high acid output and possibly in the presence of Helicobacter pylori. However, no quantitative relation between acid output and the extent of gastric metaplasia has been demonstrated and its relation to H pylori is uncertain. AIM: To determine the relation between H pylori infection and acid output and the presence and extent of gastric metaplasia in the duodenal bulb. subjects: H pylori positive and negative patients with duodenal ulcer and healthy controls were studied. METHODS: Quadrantic duodenal bulb biopsy specimens were taken and the presence and extent of gastric metaplasia determined using a computer enhanced image intensifier. Basal and stimulated acid outputs were measured. RESULTS: gastric metaplasia was significantly (p < 0.05 more common and significantly (p < 0.05) greater in extent in patients with duodenal ulcer than in controls. Neither the prevalence or extent of gastric metaplasia was affected by H pylori status. There were significant (p < 0.01) direct correlations between acid output and extent of gastric metaplasia. CONCLUSIONS: Prevalence and extent of gastric metaplasia are not related to H pylori in controls, or in patients with duodenal ulcer. Rather, high acid response to gastrin may be more important. Images Figure 1 PMID:8944558

  10. Gastric acid inhibitory and gastric protective effects of Cannabis and cannabinoids.

    PubMed

    Abdel-Salam, Omar

    2016-05-01

    Cannabis sativa has long been known for its psychotropic effect. Only recently with the discovery of the cannabinoid receptors, their endogenous legends and the enzymes responsible for their synthesis and degradation, the role of this 'endocannabinoid system' in different pathophysiologic processes is beginning to be delineated. There is evidence that CB1 receptor stimulation with synthetic cannabinoids or Cannabis sativa extracts rich in Δ(9)-tetrahydrocannabinol inhibit gastric acid secretion in humans and experimental animals. This is specially seen when gastric acid secretion is stimulated by pentagastrin, carbachol or 2-deoxy-d-glucose. Cannabis and/or cannabinoids protect the gastric mucosa against noxious challenge with non-steroidal anti-inflammatory drugs, ethanol as well as against stress-induced mucosal damage. Cannabis/cannabinoids might protect the gastric mucosa by virtue of its antisecretory, antioxidant, anti-inflammatory, and vasodilator properties. PMID:27261847

  11. Gastric emptying of organic acids in the dog.

    PubMed

    Blum, A L; Hegglin, J; Krejs, G J; Largiadèr, F; Säuberli, H; Schmid, P

    1976-10-01

    Test meals of 300 ml. of six different organic acids were instilled into the stomach of six healthy mongrel dogs. Citric, acetic, propionic, lactic, tartaric and succinic acid were given in 50, 100, 150, and 200 mN concentrations. 2. During the emptying process, the gastric contents were aspirated and immediately re-instilled at 10 min intervals, and the following parameters were recorded: volume, concentration of the organic anion, pH, hydrogen ion concentration and osmolarity. 3. By multiple stepwise regression analysis, the combination of parameters which most effectively determines gastric emptying rate was found to be: concentration of the organic anion, followed by intragastric volume and number of previous test meals given on the same day. These three parameters appear in the equation for gastric emptying rate in which the individual characteristic of each acid is expressed by a constant. 4. Among the various acids, inhibition of emptying rate increases with rising number of carboxylic groups of the acid and its molecular weight. 5. After proximal gastric vagotomy, emptying rate of organic acids is independent of volume, and emptying approaches an exponential pattern. 6. A model for gastric emptying of organic acids with at least three different receptors is proposed: one for the structure of the organic acid, one for concentration and one for intragastric volume. PMID:10436

  12. Gastric emptying of organic acids in the dog.

    PubMed Central

    Blum, A L; Hegglin, J; Krejs, G J; Largiadèr, F; Säuberli, H; Schmid, P

    1976-01-01

    Test meals of 300 ml. of six different organic acids were instilled into the stomach of six healthy mongrel dogs. Citric, acetic, propionic, lactic, tartaric and succinic acid were given in 50, 100, 150, and 200 mN concentrations. 2. During the emptying process, the gastric contents were aspirated and immediately re-instilled at 10 min intervals, and the following parameters were recorded: volume, concentration of the organic anion, pH, hydrogen ion concentration and osmolarity. 3. By multiple stepwise regression analysis, the combination of parameters which most effectively determines gastric emptying rate was found to be: concentration of the organic anion, followed by intragastric volume and number of previous test meals given on the same day. These three parameters appear in the equation for gastric emptying rate in which the individual characteristic of each acid is expressed by a constant. 4. Among the various acids, inhibition of emptying rate increases with rising number of carboxylic groups of the acid and its molecular weight. 5. After proximal gastric vagotomy, emptying rate of organic acids is independent of volume, and emptying approaches an exponential pattern. 6. A model for gastric emptying of organic acids with at least three different receptors is proposed: one for the structure of the organic acid, one for concentration and one for intragastric volume. PMID:10436

  13. Transport of Zinc Oxide Nanoparticles in a Simulated Gastric Environment

    NASA Astrophysics Data System (ADS)

    Mayfield, Ryan T.

    Recent years have seen a growing interest in the use of many types of nano sized materials in the consumer sector. Potential uses include encapsulation of nutrients, providing antimicrobial activity, altering texture, or changing bioavailability of nutrients. Engineered nanoparticles (ENP) possess properties that are different than larger particles made of the same constituents. Properties such as solubility, aggregation state, and toxicity can all be changed as a function of size. The gastric environment is an important area for study of engineered nanoparticles because of the varied physical, chemical, and enzymatic processes that are prevalent there. These all have the potential to alter those properties of ENP that make them different from their bulk counterparts. The Human Gastric Simulator (HGS) is an advanced in vitro model that can be used to study many facets of digestion. The HGS consists of a plastic lining that acts as the stomach cavity with two sets of U-shaped arms on belts that provide the physical forces needed to replicate peristalsis. Altering the position of the arms or changing the speed of the motor which powers them allows one to tightly hone and replicate varied digestive conditions. Gastric juice, consisting of salts, enzymes, and acid levels which replicate physiological conditions, is introduced to the cavity at a controllable rate. The release of digested food from the lumen of simulated stomach is controlled by a peristaltic pump. The goal of the HGS is to accurately and repeatedly simulate human digestion. This study focused on introducing foods spiked with zinc oxide ENP and bulk zinc oxide into the HGS and then monitoring how the concentration of each changed at two locations in the HGS over a two hour period. The two locations chosen were the highest point in the lumen of the stomach, which represented the fundus, and a point just beyond the equivalent of the pylorus, which represented the antrum of the stomach. These points were

  14. Regulation of peptide YY homeostasis by gastric acid and gastrin.

    PubMed

    Gomez, G; Padilla, L; Udupi, V; Tarasova, N; Sundler, F; Townsend, C M; Thompson, J C; Greeley, G H

    1996-04-01

    Peptide YY (PYY) is a gut hormone localized primarily in the distal bowel. Because circulating PYY inhibits gastric acid secretion, we investigated the effects of gastric acid secretion and gastrin on gene expression and secretion of PYY. In conscious dogs, PYY release in response to oral food was inhibited (P < 0.05) by pharmacologic inhibition of gastric acid secretion (omeprazole, famotidine). In rats, omeprazole treatment resulted in a significant elevation in serum gastrin concentrations and a simultaneous decrease in PYY messenger RNA (mRNA) and peptide levels in the colon; administration of a gastrin receptor antagonist (L365, 260) prevented the inhibitory actions of omeprazole on colonic PYY mRNA levels. In athymic-nude mice, implantation of a human gastrinoma resulted in an elevation of serum gastrin concentrations and a concomitant depression of colonic PYY mRNA levels. We conclude that endogenous gastric acid secretion up-regulates PYY release and PYY mRNA expression. Circulating gastrin acts to down-regulate PYY release and PYY mRNA expression. This study provides evidence that foregut functions (i.e., gastric acid secretion and gastrin release) exert control over an antiacid signal (e.g. PYY release) emanating from the hindgut. PMID:8625912

  15. Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

    SciTech Connect

    Becker, Jan C. . E-mail: beckeja@uni-muenster.de; Grosser, Nina; Waltke, Christian; Schulz, Stephanie; Erdmann, Kati; Domschke, Wolfram; Schroeder, Henning; Pohle, Thorsten

    2006-07-07

    Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection.

  16. Circadian gastric acidity in Helicobacter pylori positive ulcer patients with and without gastric metaplasia in the duodenum.

    PubMed Central

    Savarino, V; Mela, G S; Zentilin, P; Mele, M R; Lapertosa, L; Patetta, R; Dallorto, E; Vassallo, A; Mansi, C; Vigneri, S; Celle, G

    1996-01-01

    BACKGROUND: The presence of gastric metaplasia allows helicobacter pylori to colonise the duodenum and this condition is thought to be acquired as a response to acid hypersecretion. This functional disorder, however, is present only in a subgroup of duodenal ulcer patients and, in addition, surface gastric metaplasia has been frequently found in the proximal duodenum of normal subjects and patients with non-ulcer dyspepsia, who cannot be certainly considered as acid hypersecretors. AIMS: To clarify the role of acid in inducing gastric type epithelium in the duodenum. This study aimed at assessing whether the pattern of circadian gastric acidity differs between H pylori positive duodenal ulcer patients with and without duodenal gastric metaplasia. PATIENTS: Seventy one patients with duodenal ulcer confirmed by endoscopy and who were found to be positive for H pylori infection by histology on antrum biopsy specimens were enrolled into this study. METHODS: Gastric type epithelium in the duodenum was found in 49 of 71 ulcer patients (69%). Continuous 24 hour gastric pH metry was performed in 50 healthy subjects and in the two subgroups of duodenal ulcer patients with and without gastric metaplasia in the duodenum. Gastric acidity was calculated for 24 hours (1700-1659), night (2000-0759) and day-time (0800-1959). RESULTS: Ulcer patients without gastric metaplasia showed a significantly higher gastric acidity (p < 0.001) than controls for every time interval considered, while the ulcer subgroup with gastric metaplasia was more acid than healthy subjects (p < 0.001) during the whole 24 hour period and the daytime. There was no difference between the two subgroups of duodenal ulcer patients with and without gastric metaplasia during the various time segments analysed. CONCLUSION: The findings confirm that the circadian gastric acidity of duodenal ulcer patients is higher than that of controls. As there is no difference in gastric pH between duodenal ulcer patients with

  17. Expression of bile acid receptor TGR5 in gastric adenocarcinoma.

    PubMed

    Cao, Weibiao; Tian, Wei; Hong, Jie; Li, Dan; Tavares, Rosemarie; Noble, Lelia; Moss, Steven F; Resnick, Murray B

    2013-02-15

    Bile reflux is a risk factor in the development of intestinal metaplasia in the stomach and is believed to function as an initiator of gastric carcinogenesis. However, whether the G protein-coupled bile acid receptor TGR5 is expressed in this tumor is not known. In this study, we determined the expression of TGR5 in gastric adenocarcinoma and examined the role of TGR5 in cell proliferation. Strong TGR5 staining was present in 12% of cases of intestinal metaplasia but in no cases of normal gastric epithelium (P < 0.01). Moderate to strong TGR5 membranous and cytoplasmic staining was present in 52% of the intestinal but in only 25% of the diffuse subtype of adenocarcinomas (P < 0.001). Kaplan-Meier univariate survival analysis revealed that moderate to strong TGR5 staining was associated with decreased patient survival (P < 0.05). Treatment with taurodeoxycholic acid (TDCA, a bile acid) significantly increased thymidine incorporation in the AGS gastric adenocarcinoma cell line, suggesting that bile acids may increase cell proliferation. This increase was significantly decreased by knockdown of TGR5 with TGR5 small-interfering RNA (siRNA). In addition, overexpression of TGR5 significantly enhanced TDCA-induced increases in thymidine incorporation. TGR5 is coupled with G(q)α and Gα(i-3) proteins. TDCA-induced increase in thymidine incorporation was significantly decreased by knockdown of G(q)α and Gα(i-3) with their siRNAs. We conclude that TGR5 is overexpressed in most gastric intestinal-type adenocarcinomas, and moderate to strong TGR5 staining is associated with decreased patient survival in all gastric adenocarcinomas. Bile acids increase cell proliferation via activation of TGR5 receptors and G(q)α and Gα(i-3) proteins. PMID:23238937

  18. 21 CFR 862.1320 - Gastric acidity test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Gastric acidity test system. 862.1320 Section 862.1320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  19. 21 CFR 862.1320 - Gastric acidity test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Gastric acidity test system. 862.1320 Section 862.1320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  20. 21 CFR 862.1320 - Gastric acidity test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Gastric acidity test system. 862.1320 Section 862.1320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  1. 21 CFR 862.1320 - Gastric acidity test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Gastric acidity test system. 862.1320 Section 862.1320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  2. 21 CFR 862.1320 - Gastric acidity test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gastric acidity test system. 862.1320 Section 862.1320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  3. Genetic Evolution of a Helicobacter pylori Acid-Sensing Histidine Kinase and Gastric Disease.

    PubMed

    Krishna, Uma; Romero-Gallo, Judith; Suarez, Giovanni; Azah, Ayeetin; Krezel, Andrzej M; Varga, Matthew G; Forsyth, Mark H; Peek, Richard M

    2016-08-15

    Helicobacter pylori is the strongest risk factor for gastric adenocarcinoma, which develops within a hypochlorhydric environment. We sequentially isolated H. pylori (strain J99) from a patient who developed corpus-predominant gastritis and hypochlorhydia over a 6-year interval. Archival J99 survived significantly better under acidic conditions than recent J99 strains. H. pylori arsRS encodes a 2-component system critical for stress responses; recent J99 isolates harbored 2 nonsynonymous arsS mutations, and arsS inactivation abolished acid survival. In vivo, acid-resistant archival, but not recent J99, successfully colonized high-acid-secreting rodents. Thus, genetic evolution of arsS may influence progression to hypochlorhydia and gastric cancer. PMID:27190191

  4. The effect of Aloe vera A. Berger (Liliaceae) on gastric acid secretion and acute gastric mucosal injury in rats.

    PubMed

    Yusuf, Sadiq; Agunu, Abdulkarim; Diana, Mshelia

    2004-07-01

    The effect of varying doses of ethanol extract of Aloe vera (Liliaceae) on acute gastric mucosal lesions induced by 0.6 M HCl and acid output was studied in the pylorus ligated and lumen perfuse rats, respectively. Acid secretion was determined by titration of the collected gastric juice to pH 7.0. Intraperitoneal injection of Aloe vera, dose dependently inhibited gastric acid secretion. The plant was more active as a gastroprotective agent at lower concentration against mucosal injury induced by 0.6 M HCl. In conclusion, Aloe vera is endowed with gastric acid anti-secretory activity and could protect the gastric mucosa at low concentrations against injurious agents. PMID:15182901

  5. Concentrations of acidic antiinflammatory drugs in gastric mucosa.

    PubMed

    Frey, H H; El-Sayed, M A

    1977-12-01

    In rats, the concentrations of the acidic antiinflammatory drugs salicylic acid, acetylsalicylic acid, phenylbutazone, flufenamic acid and indomethacin in the glandular portion of the gastric mucosa were determined 30 and 60 min after oral or subcutaneous administration. In another series of experiments, solutions of the drugs were introduced into the ligated stomach and the concentrations in the mucosa and in the contents of the stomach were determined after 60 min. The ratio between the concentrations in the musoca and those in serum or gastric contents were much lower than expected according to the distribution by passive non-ionic diffusion. This apparent discrepancy may be explained as a result of a drug-induced damage to the mucosal cell allowing free diffusion of ionized drug across the cell membrane. PMID:603322

  6. Docosahexaenoic acid, an omega-3 polyunsaturated acid protects against indomethacin-induced gastric injury.

    PubMed

    Pineda-Peña, Elizabeth Arlen; Jiménez-Andrade, Juan Miguel; Castañeda-Hernández, Gilberto; Chávez-Piña, Aracely Evangelina

    2012-12-15

    Previous studies have shown gastroprotective effect of fish oil in several experimental models. However, the mechanisms and active compounds underlying this effect are not fully understood. Fish oil has several components; among them, one of the most studied is docosahexaenoic acid (DHA), which is an omega-3 long-chain polyunsaturated fatty acid. The aim of this study was to examine the gastroprotective effect of DHA as a pure compound in a rat model of indomethacin-induced gastric injury as well as elucidate some of the mechanism(s) behind DHA's gastroprotective effect. Indomethacin was orally administered to induce an acute gastric injury (3, 10 and 30mg/kg). Omeprazol (a proton pump inhibitor, 30mg/kg, p.o.) and DHA (3, 10, 30mg/kg, p.o.) were gavaged 30 and 120min, respectively, before indomethacin insult (30mg/kg p.o.). Three hours after indomethacin administration, rats were sacrificed, gastric injury was evaluated by determining the total damaged area. A sample of gastric tissue was harvested and processed to quantify prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4)) levels by enzyme-linked immunosorbent assay. Indomethacin produced gastric injury in dose-dependent manner. DHA protected against indomethacin-induced gastric damage, and this effect was comparable with omeprazol's gastroprotective effect. DHA did not reverse the indomethacin-induced reduction of PGE(2) gastric levels. In contrast, DHA partially prevented the indomethacin-induced increase in LTB(4) gastric levels. This is the first report demonstrating DHA's gastroprotective effect as a pure compound. Furthermore, the results reveal that the gastroprotective effect is mediated by a decrease in gastric LTB(4) levels in indomethacin-induced gastric damage. PMID:23063544

  7. Papain reduces gastric acid secretion induced by histamine and other secretagogues in anesthetized rats.

    PubMed

    Cho, C H; Han, P W

    1984-04-01

    We studied the effect of papain on rats' gastric acid secretion and found that: 1. Feeding of latex of unripe papaya fruit significantly reduced gastric acid secretion induced by methacholine; 2. Feeding of crystalline papain in doses of 3.2 mg/kg reduced gastric acid secretion induced by histamine, methacholine and tetragastrin; 3. The reduction of gastric acid secretion was observed as early as 2 hours after papain feeding, lasted up to 48 hours, and waned within 96 hours; 4. Intraperitoneal injection of papain had no effect on acid secretion. These results led us to believe tha the effect of papain on gastric acid secretion is a local one acting directly on the gastric mucosa, and this local effect of a single dose of papain is reversible, causing no permanent damage to the mucosa. PMID:6400589

  8. Evaluation of Acid Tolerance of Drugs Using Rats and Dogs Controlled for Gastric Acid Secretion.

    PubMed

    Kosugi, Yohei; Yamamoto, Syunsuke; Sano, Noriyasu; Furuta, Atsutoshi; Igari, Tomoko; Fujioka, Yasushi; Amano, Nobuyuki

    2015-09-01

    We attempted to establish animal models to evaluate the effects of drug degradation in the stomach on oral bioavailability. In addition, we assessed the utilization of animal studies in determining the need for enteric-coated formulations. In order to control the gastric pH in rats and dogs, appropriate dosing conditions were investigated using pentagastrin and rabeprazole, which stimulate and inhibit gastric acid secretion. Using animals controlled for gastric acid secretion, the area under curve (AUC) ratios (AUC with rabeprazole/AUC with pentagastrin) of all compounds unstable under acidic conditions were evaluated. The AUC ratios of omeprazole and erythromycin, which are administered orally to humans, as enteric-coated tablets, were greater than 1.9 in the rats and dogs controlled for gastric acid secretion. On the contrary, the AUC ratios of clarithromycin, azithromycin, and etoposide (commercially available as a standard immediate-release form) were less than 1.3 each. In conclusion, in vivo models using rats and dogs were optimized to evaluate the effects of gastric acid on the oral bioavailability of drugs, and demonstrated that in vivo models can lead to a better understanding of the oral bioavailability, with respect to the formulation development. PMID:25720462

  9. Cadmium inhibits acid secretion in stimulated frog gastric mucosa

    SciTech Connect

    Gerbino, Andrea; Debellis, Lucantonio; Caroppo, Rosa; Curci, Silvana; Colella, Matilde

    2010-06-01

    Cadmium, a toxic environmental pollutant, affects the function of different organs such as lungs, liver and kidney. Less is known about its toxic effects on the gastric mucosa. The aim of this study was to investigate the mechanisms by which cadmium impacts on the physiology of gastric mucosa. To this end, intact amphibian mucosae were mounted in Ussing chambers and the rate of acid secretion, short circuit current (I{sub sc}), transepithelial potential (V{sub t}) and resistance (R{sub t}) were recorded in the continuous presence of cadmium. Addition of cadmium (20 {mu}M to 1 mM) on the serosal but not luminal side of the mucosae resulted in inhibition of acid secretion and increase in NPPB-sensitive, chloride-dependent short circuit current. Remarkably, cadmium exerted its effects only on histamine-stimulated tissues. Experiments with TPEN, a cell-permeant chelator for heavy metals, showed that cadmium acts from the intracellular side of the acid secreting cells. Furthermore, cadmium-induced inhibition of acid secretion and increase in I{sub sc} cannot be explained by an action on: 1) H{sub 2} histamine receptor, 2) Ca{sup 2+} signalling 3) adenylyl cyclase or 4) carbonic anhydrase. Conversely, cadmium was ineffective in the presence of the H{sup +}/K{sup +}-ATPase blocker omeprazole suggesting that the two compounds likely act on the same target. Our findings suggest that cadmium affects the functionality of histamine-stimulated gastric mucosa by inhibiting the H{sup +}/K{sup +}-ATPase from the intracellular side. These data shed new light on the toxic effect of this dangerous environmental pollutant and may result in new avenues for therapeutic intervention in acute and chronic intoxication.

  10. Surviving the acid barrier: responses of pathogenic Vibrio cholerae to simulated gastric fluid.

    PubMed

    Singh, Atheesha; Barnard, Tobias G

    2016-01-01

    When bacteria are subjected to low acidic pHs of the gastric environment, they may enter the viable but nonculturable (VBNC) state of survival. In this state, bacteria cannot be cultured on solid media, still exhibit signs of metabolic activity (viability). In this study, the response of pathogenic Vibrio cholerae O1 and O139 to low pH-simulated environments of the human stomach was evaluated for their survival by culturability (plate count) and viability (flow cytometry-FC) assays. Bacteria were acid challenged with simulated gastric fluid (SGF) at pH 1.5, 2.5, 3.5 and 4.5 over a period of 180 min. Exposure to SGF up to 120 min increased acid tolerance of the Vibrios up to pH 3.5 with acid challenge occurring at pH 4.5. Bacteria were culturable from pH 2.5 to 4.5 up to 60 min SGF exposure. The stationary-phase cultures of Vibrio were able to survive SGF at all pHs in an 'injured' state with FC. This could possibly mean that the bacteria have entered the VBNC stage of survival. This is a worrying public health concern due to the fact that once favourable conditions arise (intestines), these Vibrios can change back to an infectious state and cause disease. PMID:26496916

  11. Effects of paracetamol and propacetamol on gastric mucosal damage and gastric lipid peroxidation caused by acetylsalicylic acid (ASA) in rats.

    PubMed

    Galunska, B; Marazova, K; Tankova, T; Popov, A; Frangov, P; Krushkov, I; Di Massa, A

    2002-08-01

    We have studied the effect of paracetamol and its pro-drug propacetamol on gastric mucosal damage induced by acetylsalicylic acid (ASA) and its possible relation to changes in gastric lipid peroxidation status in rats. Paracetamol or propacetamol were administered intragastrically 1h before ASA (300 mg kg(-1)) in the following equivalent doses: 62.5, 125.0 and 250.0 mg kg(-1) or 125.0, 250.0 and 500.0 mg kg(-1), respectively. The effects of the tested agents were compared to that of prostaglandin E2 (PGE2) 15, 30 and 60 mg kg(-1). Gastric ulcer formation was estimated morphometrically 4h after ASA administration. Malondialdehyde (MDA), glutathione (reduced, GSH, and oxidized, GSSG) and uric acid (UA) were determined in gastric mucosa and blood plasma and used as biochemical markers of the oxidative status. The results showed that paracetamol (250, 125, 62.5 mg kg(-1)) and propacetamol (500, 250, 125 mg kg(-1)) diminished the area of ASA-induced gastric lesions. The effect of propacetamol was more pronounced than that of paracetamol and similar to that of PGE2. Gastric MDA increased 3-fold in the ASA-group. The tested agents reduced it by a range of 30-70%. In all pretreated groups gastric glutathione and UA levels were found higher than that of control group and lower than that of ASA-group. Paracetamol and propacetamol, as well as PGE2, diminished the lipid peroxidation in plasma to a lesser extent than in gastric mucosa, but maintained elevated levels of the selective plasma antioxidant UA. These results show that the ASA-induced gastric mucosal damage is accompanied by the development of oxidative stress, evidenced by the accumulation of MDA, and concomitant initial activation of cell antioxidant defences. As paracetamol and propacetamol tend to decrease gastric lesions caused by ASA and alter gastric mucosal MDA, glutathione and UA values in a favorable manner, it could be suggested that their effects on the gastric mucosa could be related to interference with

  12. Correlation between gastric acid secretion and severity of acid reflux in children.

    PubMed

    Kalach, Nicolas; Badran, Abdul Monem; Jaffray, Patrick; Campeotto, Florence; Benhamou, Pierre Henri; Dupont, Christophe

    2003-01-01

    The purpose of our study was to systematically evaluate gastric acid output in children with long-lasting gastro-esophageal reflux (GER) in order to assess its mechanism and the need for anti-acid treatment. The investigation was carried out in 20 males and 10 females, aged 7.5 +/- 3.8 years, with prolonged (>15 months) clinical manifestations of GER. All underwent routine ambulatory 24-h esophageal pH-monitoring and measurement of gastric acid secretion including gastric basal (BAO) (micromol/kg/h), maximal (MAO) and peak acid outputs (PAO) after pentagastrin (6 microg/kg sec) stimulation. Children with heartburn or abdominal pain underwent upper fiber-endoscopy. In group A (moderate GER, n=12), patients had a normal reflux index (pH<4 below 5.2% of total recording time) despite abnormal Euler and Byrne scoring (median 57, 95% confidence interval 53.5-73.4). In group B (severe GER, n=18, among whom 5 were with grade III esophagitis), reflux index was >5.2%. When considering all children, esophageal pH (%) was significantly correlated with MAO and PAO, r=0.33, p=0.05 and r=0.37, p=0.04, respectively. Children of group B exhibited significantly higher BAO (75, 53.96-137.81), MAO (468, 394.1-671.3) and PAO (617, 518.8-782.3) than those of group A, BAO (27, 10.8-38.5), MAO (266, 243.2-348.2) and PAO (387, 322.5-452.7), p<0.05). The five children of group B with severe esophagitis exhibited significantly higher BAO, MAO and PAO than the other 13 children from the same group and those of group A, p<0.05. Children with long-lasting and severe GER hyper-secrete gastric acid. Individual variations in gastric acid secretion probably account for variations in gastric acid inhibitor requirements. Anti-secretory treatment is justified in children with long-lasting GER and high pH-metric reflux index. PMID:12718363

  13. Motilin Stimulates Gastric Acid Secretion in Coordination with Ghrelin in Suncus murinus.

    PubMed

    Goswami, Chayon; Shimada, Yoshiaki; Yoshimura, Makoto; Mondal, Anupom; Oda, Sen-ichi; Tanaka, Toru; Sakai, Takafumi; Sakata, Ichiro

    2015-01-01

    Motilin and ghrelin constitute a peptide family, and these hormones are important for the regulation of gastrointestinal motility. In this study, we examined the effect of motilin and ghrelin on gastric acid secretion in anesthetized suncus (house musk shrew, Suncus murinus), a ghrelin- and motilin-producing mammal. We first established a gastric lumen-perfusion system in the suncus and confirmed that intravenous (i.v.) administration of histamine (1 mg/kg body weight) stimulated acid secretion. Motilin (0.1, 1.0, and 10 μg/kg BW) stimulated the acid output in a dose-dependent manner in suncus, whereas ghrelin (0.1, 1.0, and 10 μg/kg BW) alone did not induce acid output. Furthermore, in comparison with the vehicle administration, the co-administration of low-dose (1 μg/kg BW) motilin and ghrelin significantly stimulated gastric acid secretion, whereas either motilin (1 μg/kg BW) or ghrelin (1 μg/kg BW) alone did not significantly induce gastric acid secretion. This indicates an additive role of ghrelin in motilin-induced gastric acid secretion. We then investigated the pathways of motilin/motilin and ghrelin-stimulated acid secretion using receptor antagonists. Treatment with YM 022 (a CCK-B receptor antagonist) and atropine (a muscarinic acetylcholine receptor antagonist) had no effect on motilin or motilin-ghrelin co-administration-induced acid output. In contrast, famotidine (a histamine H2 receptor antagonist) completely inhibited motilin-stimulated acid secretion and co-administration of motilin and ghrelin induced gastric acid output. This is the first report demonstrating that motilin stimulates gastric secretion in mammals. Our results also suggest that motilin and co-administration of motilin and ghrelin stimulate gastric acid secretion via the histamine-mediated pathway in suncus. PMID:26115342

  14. Motilin Stimulates Gastric Acid Secretion in Coordination with Ghrelin in Suncus murinus

    PubMed Central

    Goswami, Chayon; Shimada, Yoshiaki; Yoshimura, Makoto; Mondal, Anupom; Oda, Sen-ichi; Tanaka, Toru; Sakai, Takafumi; Sakata, Ichiro

    2015-01-01

    Motilin and ghrelin constitute a peptide family, and these hormones are important for the regulation of gastrointestinal motility. In this study, we examined the effect of motilin and ghrelin on gastric acid secretion in anesthetized suncus (house musk shrew, Suncus murinus), a ghrelin- and motilin-producing mammal. We first established a gastric lumen-perfusion system in the suncus and confirmed that intravenous (i.v.) administration of histamine (1 mg/kg body weight) stimulated acid secretion. Motilin (0.1, 1.0, and 10 μg/kg BW) stimulated the acid output in a dose-dependent manner in suncus, whereas ghrelin (0.1, 1.0, and 10 μg/kg BW) alone did not induce acid output. Furthermore, in comparison with the vehicle administration, the co-administration of low-dose (1 μg/kg BW) motilin and ghrelin significantly stimulated gastric acid secretion, whereas either motilin (1 μg/kg BW) or ghrelin (1 μg/kg BW) alone did not significantly induce gastric acid secretion. This indicates an additive role of ghrelin in motilin-induced gastric acid secretion. We then investigated the pathways of motilin/motilin and ghrelin-stimulated acid secretion using receptor antagonists. Treatment with YM 022 (a CCK-B receptor antagonist) and atropine (a muscarinic acetylcholine receptor antagonist) had no effect on motilin or motilin-ghrelin co-administration-induced acid output. In contrast, famotidine (a histamine H2 receptor antagonist) completely inhibited motilin-stimulated acid secretion and co-administration of motilin and ghrelin induced gastric acid output. This is the first report demonstrating that motilin stimulates gastric secretion in mammals. Our results also suggest that motilin and co-administration of motilin and ghrelin stimulate gastric acid secretion via the histamine-mediated pathway in suncus. PMID:26115342

  15. Activiation of the calcium sensing receptor stimulates serum gastrin and gastric acid secretion in healthy subjects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastric acid secretion is a complex process regulated by neuronal and hormonal pathways. Ex vivo studies in human gastric tissues indicate that the calcium sensing receptor (CaR), expressed on the surface of G and parietal cells, may be involved in this regulation. We sought to determine whether cin...

  16. Activation of the calcium sensing receptor stimulates gastrin and gastric acid secretion in healthy participants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastric acid secretion is a complex process regulated by neuronal and hormonal pathways. Ex vivo studies in human gastric tissues indicate that the calcium sensing receptor (CaR), expressed on the surface of G and parietal cells, may be involved in this regulation. We sought to determine whether cin...

  17. Activation of the calcium sensing receptor stimulates serum gastrin and gastric acid secretion in healthy subjects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastric acid secretion is a complex process regulated by neuronal and hormonal pathways. Ex vivo studies in human gastric tissues indicate that the calcium sensing receptor (CaR), expressed on the surface of G and parietal cells, may be involved in this regulation. We sought to determine whether cin...

  18. The effects of aqueous extract of Aloe vera leaves on the gastric acid secretion and brain and intestinal water content following acetic acid- induced gastric ulcer in male rats

    PubMed Central

    Keshavarzi, Zakieh; Rezapour, Taha Mohammad; Vatanchian, Mehran; Zare Hesari, Mohammad; Nabizade Haghighi, Hadi; Izanlu, Mostafa; Sabaghian, Maryam; Shahveisi, Kaveh

    2014-01-01

    Objective: Gut–brain axis (GBA) is very important in creation and modulation of gastrointestinal problems. Aloe vera gel has gastroprotective properties. The purpose of this study was to evaluate the effect of aqueous extract of Aloe vera leaves on the gastric acid secretion and brain and intestinal water content following acetic acid gastric ulcer induction. Materials and Methods: Gastric ulcer was induced by injection of 20% acetic acid into the subserosal layer in male rats. Rats were randomly assigned into three groups: intact group, gastric ulcer group and Aloe vera group (treatment with Aloe vera following gastric ulcer induction). The acid levels and brain and intestinal water content of each sample were measured eight days after the gastric ulcer induction. Results: Gastric acid levels were significantly decreased in Aloe vera group when compared with gastric ulcer group (p<0.05). However, there were no differences in acid output between gastric ulcer and Aloe vera groups with intact group. After Aloe vera administration, the amount of brain water content had no difference with intact and gastric ulcer groups (p<0.05). The duodenal water content in Aloe vera group was significantly reduced compared with intact group (p<0.05) but gastric ulcer group had no significant difference with intact and Aloe vera group. Conclusions: The administration of Aloe vera has an inhibitory effect on the gastric acid output. PMID:25050311

  19. The healing effect of TGF-alpha on gastric ulcer induced by acetylsalicylic acid in rats.

    PubMed

    Yetkin, G; Celebi, N; Ozer, C; Gönül, B; Ozoğul, C

    2004-06-11

    The present study was designed to investigate the effects of microemulsion and aqueous solution containing transforming growth factor alpha (TGF-alpha) and/or aprotinin administered intragastrically (i.g.) on healing of acute gastric ulcers induced by acetylsalicylic acid (ASA). The microemulsion was prepared by modification of the microemulsion formulation described in our previous study. Acute gastric lesions were induced by the application of ASA (150 mg/kg in 1.5 ml of 0.2N HCl i.g.). TGF-alpha in solution or microemulsion formulations were administered at a dose of 10 microg/kg per 24h i.g. for 2 days. The effects of TGF-alpha on the healing was evaluated with the measurement of ulcer score, basal gastric acid secretion, total protein content of gastric fluid, gastric mucus level and histological analysis. The results indicated that the highest decrease in ulcer area was observed in group treated with microemulsion containing TGF-alpha plus aprotinin (TA-ME). TGF-alpha in microemulsion formulation was more effective than TGF-alpha in solution formulation in the increase of gastric mucus secretion, in the decrease of gastric acid secretions and ulcer scores. Histological evaluation of the gastric mucosa samples revealed that, best recovery was obtained in the TA-ME treated group. PMID:15158979

  20. Ulcer healing activity of Mumijo aqueous extract against acetic acid induced gastric ulcer in rats

    PubMed Central

    Shahrokhi, Nader; Keshavarzi, Zakieh; Khaksari, Mohammad

    2015-01-01

    Objective: Gastric ulcer is an important clinical problem, chiefly due to extensive use of some drugs. The aim was to assess the activity of Mumijo extract (which is used in traditional medicine) against acetic acid induced gastric ulcer in rats. Materials and Methods: The aqueous extract of Mumijo was prepared. Animals were randomly (n = 10) divided into four groups: Control, sham-operated group (received 0.2 ml of acetic acid to induce gastric ulcer), Mumijo (100 mg/kg/daily) were given for 4 days postacetic acid administration, and ranitidine group (20 mg/kg). The assessed parameters were pH and pepsin levels (by Anson method) of gastric contents and gastric histopathology. Ranitidine was used as reference anti-ulcer drug. Results: The extract (100 mg/kg/daily, p.o.) inhibited acid acetic-induced gastric ulceration by elevating its pH versus sham group (P < 0.01) and decreasing the pepsin levels compared to standard drug, ranitidine (P < 0.05). The histopathology data showed that the treatment with Mumijo extract had a significant protection against all mucosal damages. Conclusion: Mumijo extract has potent antiulcer activity. Its anti-ulcer property probably acts via a reduction in gastric acid secretion and pepsin levels. The obtained results support the use of this herbal material in folk medicine. PMID:25709338

  1. Reduced gastric acid production in burn shock period and its significance in the prevention and treatment of acute gastric mucosal lesions.

    PubMed

    Zhu, Li; Yang, Zhong-Cheng; Li, Ao; Cheng, De-Chang

    2000-02-01

    AIM:To investigate the changes of gastric acid production and its mechanism in shock period of severe burn in rats.METHODS:A rat model with 30% TBSA full thickness burn injury was employed and the gastric acid production,together with gastric mucosal blood flow (GMBF) and energy charge (EC) were measured serially within 48h postburn.RESULTS:The gastric acid production in the acute shock period was markedly inhibited after severe burn injury.At the 3rd h postburn,the gastric juice volume, total acidity and acid output were already significantly decreased (P < 0.01 =, and reached the lowest point, 0.63mL/L ± 0.20mL/L, 10.81mmol/L ± 2.58mmol/L and 2.23mmol/h ± 0.73mmol/h respectively, at the 12th h postburn. Although restored to some degree 24h after thermal injury, the variables above were still statistically lower, compared with those of control animals at the 48th h postburn. The GMBF and EC were also significantly reduced after severe burns, consistent with the trend of gastric acid production changes.CONCLUSION:Gastric acid production, as well as GMBF and EC was predominantly decreased in the early postburn stage, suggesting that gastric mucosal ischemia and hypoxia with resultant disturbance in energy metabolism, but not gastric acid proper, might be the decisive factor in the pathogenesis of AGML after thermal injury, and that the preventive use of anti-acid drugs during burn shock period was unreasonable in some respects. Therefore, taking effective measures to improve gastric mucosal blood perfusion as early as possible postburn might be more preferable for the AGML prevention and treatment. PMID:11819529

  2. The role of gastric mucosal histamine in acid secretion and experimentally induced lesions in the rat.

    PubMed

    Andersson, K; Mattsson, H; Larsson, H

    1990-01-01

    The role played by histamine from enterochromaffin-like (ECL) cells and mast cells in gastric acid secretion and in the development of ethanol-induced gastric lesions was studied in the rat. This was done by examining the effects of inhibition of the histamine-producing enzyme histidine decarboxylase (HDC) with alpha-fluoromethylhistidine (alpha-FMH) and the effects of degranulation of the mucosal mast cells with dexamethasone. A single dose of alpha-FMH (50 mg/kg p.o.) inhibited the HDC activity by 94% but did not affect histamine levels in the gastric mucosa 2 h after dose. Repeated treatment resulted in an almost complete inhibition of HDC activity and in a reduction of histamine levels by 75%. Pentagastrin failed to stimulate acid secretion after 4 days treatment with alpha-FMH, whereas the acid response to histamine was unaffected in chronic gastric fistula rats. Ethanol failed to induce gastric lesions in rats pretreated for 4 days with dexamethasone whereas 4 days pretreatment with alpha-FMH did not influence ethanol-induced lesion formation. The present results show that histamine synthesis is required for pentagastrin-stimulated gastric acid secretion and that mucosal mast-cell histamine plays a role in the development of ethanol-induced gastric lesions. PMID:2210091

  3. Risk of Spontaneous Bacterial Peritonitis Associated With Gastric Acid Suppression

    PubMed Central

    Chang, Shy-Shin; Lai, Chih-Cheng; Lee, Meng-tse Gabriel; Lee, Yu-Chien; Tsai, Yi-Wen; Hsu, Wan-Ting; Lee, Chien-Chang

    2015-01-01

    Abstract The primary objective of this study was to determine the association between the use of gastric acid suppressants (GAS) and the risk of developing spontaneous bacterial peritonitis (SBP) in patients with advanced liver cirrhosis (LC). A case–control study nested within a cohort of 480,000 representatives of Taiwan National Health Insurance beneficiaries was carried out. A case was matched with 100 controls on age, gender, and index date of SBP diagnosis. GAS use was identified from the 1-year period before the index date. Conditional logistic regression analysis was used to adjust for various unbalanced covariates between users and nonusers of GAS. A total of 947 cases of SBP were identified among the 86,418 patients with advanced LC. A significant increased risk of developing SBP was found to be associated with current (within 30 days), and recent (within 30–90 day) use of 2 different classes of GAS: proton pump inhibitors (PPIs) and histamine 2 receptor antagonists (H2RAs). The confounder adjusted rate ratio (aRR) for the current use of PPIs was 2.77 (95%CI: 1.90–4.04) and H2RAs was 2.62 (95%CI: 2.00–3.42). The risk of SBP attenuated for the recent use of PPIs (aRR: 2.20, 95%CI: 1.60–3.02) or H2RAs (aRR: 1.72, 95%CI: 1.25–2.37). In addition, sensitivity analysis using hospitalized SBP as the primary outcome showed a similar risk for the current use of PPIs (aRR, 3.24; 95%CI: 2.08–5.05) and H2RAs (aRR 2.43; 95%CI 1.71–3.46). Furthermore, higher cumulative days of gastric acid suppression were associated with a higher risk of SBP (trend P < 0.0001). To conclude, exposure to GAS was associated with an increased risk of SBP in patients with advanced LC. The association was more pronounced in current PPI users compared with nonusers. PMID:26039135

  4. [*C]octanoic acid breath test to measure gastric emptying rate of solids.

    PubMed

    Maes, B D; Ghoos, Y F; Rutgeerts, P J; Hiele, M I; Geypens, B; Vantrappen, G

    1994-12-01

    We have developed a breath test to measure solid gastric emptying using a standardized scrambled egg test meal (250 kcal) labeled with [14C]octanoic acid or [13C]octanoic acid. In vitro incubation studies showed that octanoic acid is a reliable marker of the solid phase. The breath test was validated in 36 subjects by simultaneous radioscintigraphic and breath test measurements. Nine healthy volunteers were studied after intravenous administration of 200 mg erythromycin and peroral administration of 30 mg propantheline, respectively. Erythromycin significantly enhanced gastric emptying, while propantheline significantly reduced gastric emptying rates. We conclude that the [*C]octanoic breath test is a promising and reliable test for measuring the gastric emptying rate of solids. PMID:7995200

  5. Chitosan-poly(acrylic) acid polyionic complex: in vivo study to demonstrate prolonged gastric retention.

    PubMed

    Torrado, Susana; Prada, Pablo; de la Torre, Paloma M; Torrado, Santiago

    2004-02-01

    The aim of this study was to develop a chitosan-poly(acrylic) acid based controlled drug release system for gastric antibiotic delivery. Different mixtures of amoxicillin (A), chitosan (CS), and poly(acrylic) acid (PAA) were employed to obtain these polyionic complexes. A non-invasive method was employed for determining the gastric residence time of the formulations. It was studied the swelling behavior and drug release from these complexes. Gastric emptying rate study was performed by means of the [13C]octanoic acid breath test. The gastric emptying rates of two different formulations (conventional and gastric retentive system) were studied. Swelling studies indicated that the extent of swelling was greater in the polyionic complexes than in the single chitosan formulations. The amoxicillin diffusion from the hydrogels was controlled by the polymer/drug interaction. The property of these complexes to control the solute diffusion depends on the network mesh size, which is a significant factor in the overall behavior of the hydrogels. The gastric half-emptying time of the polyionic complex was significantly delayed compared to the reference formulation, showing mean values of 164.32+/-26.72 and 65.06+/-11.50min, respectively (P<0.01). The results of this study suggest that, these polyionic complexes are good systems for specific gastric drug delivery. PMID:14609680

  6. Two distinct etiologies of gastric cardia adenocarcinoma: interactions among pH, Helicobacter pylori, and bile acids

    PubMed Central

    Mukaisho, Ken-ichi; Nakayama, Takahisa; Hagiwara, Tadashi; Hattori, Takanori; Sugihara, Hiroyuki

    2015-01-01

    Gastric cancer can be classified as cardia and non-cardia subtypes according to the anatomic site. Although the gastric cancer incidence has decreased steadily in several countries over the past 50 years, the incidence of cardia cancers and esophageal adenocarcinoma (EAC) continue to increase. The etiological factors involved in the development of both cardia cancers and EACs are associated with high animal fat intake, which causes severe obesity. Central obesity plays roles in cardiac-type mucosa lengthening and partial hiatus hernia development. There are two distinct etiologies of cardia cancer subtypes: one associated with gastroesophageal reflux (GER), which predominantly occurs in patients without Helicobacter pylori (H. pylori) infection and resembles EAC, and the other associated with H. pylori atrophic gastritis, which resembles non-cardia cancer. The former can be developed in the environment of high volume duodenal content reflux, including bile acids and a higher acid production in H. pylori–negative patients. N-nitroso compounds, which are generated from the refluxate that includes a large volume of bile acids and are stabilized in the stomach (which has high levels of gastric acid), play a pivotal role in this carcinogenesis. The latter can be associated with the changing colonization of H. pylori from the distal to the proximal stomach with atrophic gastritis because a high concentration of soluble bile acids in an environment of low acid production is likely to act as a bactericide or chemorepellent for H. pylori in the distal stomach. The manuscript introduces new insights in causative factors of adenocarcinoma of the cardia about the role of bile acids in gastro-esophageal refluxate based upon robust evidences supporting interactions among pH, H. pylori, and bile acids. PMID:26029176

  7. Protective effect of ascorbic acid in experimental gastric cancer: reduction of oxidative stress

    PubMed Central

    P.M.S.Oliveira, Claudia; Kassab, Paulo; Lopasso, Fabio P.; Souza, Heraldo P.; Janiszewski, Mariano; Laurindo, Francisco R. M.; Iriya, Kioshi; Laudanna, Antonio A.

    2003-01-01

    AIM: Oxidative stress participates in the cell carcinogenesis by inducing DNA mutations. Our aim was to assess whether ascorbic acid, an antioxidant, could have a role in preventing ROS (Reactive Oxygen Species) generation in experimental gastric carcinoma in a rat model. METHODS: Experimental gastric cancer was induced in twelve Wistar male rats (weighting 250-350 g) by profound duodeno-gastric reflux throught split gastrojenunostomy. The rats were allocated to the following groups: Group I (n = 6) was the control; Group II (n = 6) which was mantained with daily intake of tape water with Vitamin C (30 mg/Kg). After 6 or 12 months, samples of gastric tumor or non tumor mucosa were taken from the anastomosis of both groups. Oxidative stress was measured by superoxide quantification through lucigenin-amplified chemiluminescence base and by staining with Nitrobluetetrazolium. The histopathologic confirmation of adenocarcinoma was made by eosin-hemathoxilin method. RESULTS: The intestinal type of gastric adenocarcinoma was microscopically identified in all animals of group I whereas only 3 rats of group II showed an adenocarcinoma without macroscopic evidence of them. The cancers were located in the anastomosis in all cases. Basal luminescence from tumor gastric tissue generated 38.4 ± 6.8 count per minute/mg/x106 (mean ± SD) and 14.9 ± 4.0 count per minute/mg/x106, respectively, in group I and II animals (P < 0.05). The Nitrobluetetrazolium method showed intense staining in tumor tissues but not in non neoplasic mucosa. CONCLUSION: Experimental gastric tumors seem to produce more reactive oxygen species than non neoplasic gastric tissue. The reduction of oxidative stress and gastric tumor incidence in rats were induced by the intake of ascorbic acid. Therefore, it may have a role in the prevention of gastric carcinoma. PMID:12632494

  8. Effect of mitragynine, derived from Thai folk medicine, on gastric acid secretion through opioid receptor in anesthetized rats.

    PubMed

    Tsuchiya, Shizuko; Miyashita, Sanae; Yamamoto, Makiko; Horie, Syunji; Sakai, Shin-Ichiro; Aimi, Norio; Takayama, Hiromitsu; Watanabe, Kazuo

    2002-05-17

    Mitragynine, an indole alkaloid from Thai folk medicine Mitragyna speciosa, exerts agonistic effects on opioid receptors. Gastric acid secretion is proposed to be regulated by opioid receptors in the central nervous system (CNS). Previously, we reported the dual roles (inhibition via micro-opioid receptors and stimulation via kappa-opioid receptors) of the opioid system in the central control of gastric acid secretion. We investigated whether mitragynine affects gastric acid secretion via opioid receptors in the CNS. Injection of mitragynine (30 microg) alone into the lateral cerebroventricle did not have a significant effect on basal gastric acid secretion in the perfused stomach of anesthetized rats. Injection of mitragynine (3-30 microg) into the fourth cerebroventricle, like morphine, inhibited 2-deoxy-D-glucose-stimulated gastric acid secretion. The inhibitory effect of mitragynine (30 microg) was reversed by naloxone (100 microg). These results suggest that mitragynine has a morphine-like action on gastric acid secretion in the CNS. PMID:12044808

  9. Tachykinin inhibition of acid-induced gastric hyperaemia in the rat.

    PubMed Central

    Heinemann, A.; Jocic, M.; Herzeg, G.; Holzer, P.

    1996-01-01

    1. Primary afferent neurones releasing the vasodilator, calcitonin gene-related peptide, mediate the gastric hyperaemic response to acid back-diffusion. The tachykinins neurokinin A (NKA) and substance P (SP) are located in the same neurones and are co-released with calcitonin gene-related peptide. In this study we investigated the effect and possible role of tachykinins in the acid-evoked gastric vasodilatation in urethane-anaesthetized rats. 2. Gastric acid back-diffusion, induced by perfusing the stomach with 15% ethanol in the presence of 0.05 M HCl, increased gastric mucosal blood flow by 60-90%, as determined by the hydrogen clearance technique. NKA and SP (0.14-3.78 nmol min-1 kg-1, infused intra-aortically) inhibited the gastric mucosal hyperaemic response to acid back-diffusion in a dose-dependent manner, an effect that was accompanied by aggravation of ethanol/acid-induced macroscopic haemorrhagic lesions. 3. The inhibitory effect of NKA (1.26 nmol min-1 kg-1) on the acid-induced gastric mucosal vasodilatation was prevented by the tachykinin NK2 receptor antagonists, MEN 10,627 (200 nmol kg-1) but left unaltered by the NK1 receptor antagonist, SR 140,333 (300 nmol kg-1) and the mast-cell stabilizer, ketotifen (4.6 mumol kg-1). 4. Under basal conditions, with 0.05 M HCl being perfused through the stomach, NKA (1.26 nmol min-1 kg-1) reduced gastric mucosal blood flow by about 25%, an effect that was abolished by SR 140,333 but not MEN 10,627 or ketotifen. 5. SR 140,333, MEN 10,627 or ketotifen had no significant effect on basal gastric mucosal blood flow nor did they modify the gastric mucosal hyperaemic reaction to acid back-diffusion. 6. The effect of NKA (1.26 nmol min-1 kg-1) in causing vasoconstriction and inhibiting the vasodilator response to acid back-diffusion was also seen when blood flow in the left gastric artery was measured with the ultrasonic transit time shift technique. 7. Arginine vasopressin (AVP, 0.1 nmol min-1 kg-1) induced gastric

  10. Expression of HSP72 in the gastric mucosa is regulated by gastric acid in rats-Correlation of HSP72 expression with mucosal protection

    SciTech Connect

    Wada, Isao; Otaka, Michiro . E-mail: otaka@med.akita-u.ac.jp; Jin, Mario; Odashima, Masaru; Komatsu, Koga; Konishi, Noriaki; Matsuhashi, Tamotsu; Horikawa, Youhei; Ohba, Reina; Itoh, Hideaki; Watanabe, Sumio

    2006-10-20

    Background and aim: The real mechanism of adaptive cytoprotection in the gastric mucosa is not well established. In the present study, we investigated the effect of acid suppressing agents on a 72-kDa heat shock protein (HSP72) expression, which is known as endogenous cytoprotective factor, in the gastric mucosa. Also, the association of gastric mucosal protective function against HCl-challenge was compared between HSP72-induced and -reduced group. Materials and methods: Expression of HSP72 was measured by Western blotting in the gastric mucosa before and after administration of famotidine or omeprazole. The gastric mucosal protective function against 0.6 N HCl was compared between control group and HSP72-reduced group. Also, the effect of increased expression of gastric HSP72 by additional administration of zinc sulfate or zinc L-carnosine, which is known as HSP72-inducer, on mucosal protective function was studied. Results: HSP72 expression in the gastric mucosa was reduced by acid suppressing agents. The lowest expression level of HSP72 was observed 12 h (famotidine, H2-receptor antagonist) or 48 h (omeprazole, proton pump inhibitor) after administration. The gastric mucosal protective ability against 0.6 N HCl was also reduced when HSP72 expression was decreased by famotidine or omeprazole. This phenomenon was reversed by HSP72 induction by additional administration of zinc derivatives. Conclusion: Our results might indicate that the expression of HSP72 in the gastric mucosa is physiologically regulated by gastric acid, and that HSP72 induction could be important in view of mucosal protection especially when HSP72 expression is reduced by administration of acid suppressing agents such as proton pump inhibitor or H2 receptor antagonist.

  11. Role of gastric acid secretion in the pathogenesis of Barrett's esophageal cancer in a Japanese population.

    PubMed

    Koike, Tomoyuki; Ohara, Shuichi; Shimosegawa, Tooru

    2009-06-01

    The acidity of the refluxate into the esophagus is an important factor not only for reflux esophagitis, but also for Barrett's esophagus and the development of Barrett's esophageal cancer. On the other hand, H. pylori infection is thought to prevent reflux esophagitis and Barrett's esophagus by causing atrophic gastritis, which in turn decreases gastric acid secretion. Moreover, the preservation of gastric acid secretion may be important for the development of gastroesophageal junction cancer, including Barrett's esophageal cancer, irrespective of the H. pylori infection status. An increase in gastric acid secretion in Japanese populations has been predicted based on a decreasing rate of H. pylori infection and the westernization of eating habits in Japan; this, in turn, may lead to an increase in the prevalence of Barrett's esophageal cancer in Japan in the future. PMID:26192284

  12. A Mechanistic Study on the Destabilization of Whole Inactivated Influenza Virus Vaccine in Gastric Environment

    PubMed Central

    Choi, Hyo-Jick; Ebersbacher, Charles F.; Kim, Min-Chul; Kang, Sang-Moo; Montemagno, Carlo D.

    2013-01-01

    Oral immunization using whole inactivated influenza virus vaccine promises an efficient vaccination strategy. While oral vaccination was hampered by harsh gastric environment, a systematic understanding about vaccine destabilization mechanisms was not performed. Here, we investigated the separate and combined effects of temperature, retention time, pH, and osmotic stress on the stability of influenza vaccine by monitoring the time-dependent morphological change using stopped-flow light scattering. When exposed to osmotic stress, clustering of vaccine particles was enhanced in an acidic medium (pH 2.0) at ≥25°C. Fluorescence spectroscopic studies showed that hyper-osmotic stress at pH 2.0 and 37°C caused a considerable increase in conformational change of antigenic proteins compared to that in acidic iso-osmotic medium. A structural integrity of membrane was destroyed upon exposure to hyper-osmotic stress, leading to irreversible morphological change, as observed by undulation in stopped-flow light scattering intensity and transmission electron microscopy. Consistent with these analyses, hemagglutination activity decreased more significantly with an increasing magnitude of hyper-osmotic stress than in the presence of the hypo- and iso-osmotic stresses. This study shows that the magnitude and direction of the osmotic gradient has a substantial impact on the stability of orally administrated influenza vaccine. PMID:23776657

  13. An evaluation of the importance of gastric acid secretion in the absorption of dietary calcium.

    PubMed Central

    Bo-Linn, G W; Davis, G R; Buddrus, D J; Morawski, S G; Santa Ana, C; Fordtran, J S

    1984-01-01

    Since calcium solubility is a prerequisite to calcium absorption, and since solubility of calcium is highly pH-dependent, it has been generally assumed that gastric acid secretion and gastric acidity play an important role in the intestinal absorption of calcium from ingested food or calcium salts such as CaCO3. To evaluate this hypothesis, we developed a method wherein net gastrointestinal absorption of calcium can be measured after ingestion of a single meal. A large dose of cimetidine, which markedly reduced gastric acid secretion, had no effect on calcium absorption in normal subjects, and an achlorhydric patient with pernicious anemia absorbed calcium normally. This was true regardless of the major source of dietary calcium (i.e., milk, insoluble calcium carbonate, or soluble calcium citrate). Moreover, calcium absorption after CaCO3 ingestion was the same when intragastric contents were maintained at pH 7.4 (by in vivo titration) as when intragastric pH was 3.0. On the basis of these results, we conclude that gastric acid secretion and gastric acidity do not normally play a role in the absorption of dietary calcium. Other possible mechanisms by which the gastrointestinal tract might solubilize ingested calcium complexes and salts are discussed. Images PMID:6707197

  14. Acupuncture inhibits vagal gastric acid secretion stimulated by sham feeding in healthy subjects.

    PubMed

    Lux, G; Hagel, J; Bäcker, P; Bäcker, G; Vogl, R; Ruppin, H; Domschke, S; Domschke, W

    1994-08-01

    In a prospective randomised study, the effect of acupuncture on sham feeding stimulated gastric acid secretion was investigated. In eight healthy volunteers (five men, three women, mean (SEM) age 26.3 (4.7) years) various methods of acupuncture were performed. Apart from the sham procedure, the acupuncture was performed at the classic acupuncture points. Electroacupuncture reduced gastric acid secretion expressed as median (range) significantly during the first 30 minute period to 1.6 (0-5.2) mmol compared with 3.8 (2.3-14.5) mmol (p < 0.05) during control period (sham feeding without acupuncture). Inhibition of gastric acid secretion by electroacupuncture was also significant during the second 30 minute period (0.2 (0-5.6) v 3.6 (0.3-9.1) mmol; p < 0.05) and for peak acid output (0.8 (0.2-5.1) v 7.6 (3.4-12.1) mmol; p < 0.05). Transcutaneous electrical nerve stimulation also resulted in significant reduction of gastric acid secretion during the first 30 minute period (1.0 (0-3.6) mmol v 3.8 (2.3-14.5) mmol; p < 0.05), and peak acid output (3.6 (1.2-12.0) v 7.6 (3.4-12.1) mmol; p < 0.05). The classic needle acupuncture, laser acupuncture, and sham acupuncture had no significant effect on gastric acid secretion. This study shows firstly that in healthy volunteers, only the versions of acupuncture using more pronounced stimulation (electroacupuncture, transcutaneous electrical nerve stimulation), but not those with only mild stimulation of the nerves (classic needle acupuncture, laser acupuncture), and secondly only acupuncture performed at defined points lead to significant reduction in gastric acid secretion. PMID:7926899

  15. Acupuncture inhibits vagal gastric acid secretion stimulated by sham feeding in healthy subjects.

    PubMed Central

    Lux, G; Hagel, J; Bäcker, P; Bäcker, G; Vogl, R; Ruppin, H; Domschke, S; Domschke, W

    1994-01-01

    In a prospective randomised study, the effect of acupuncture on sham feeding stimulated gastric acid secretion was investigated. In eight healthy volunteers (five men, three women, mean (SEM) age 26.3 (4.7) years) various methods of acupuncture were performed. Apart from the sham procedure, the acupuncture was performed at the classic acupuncture points. Electroacupuncture reduced gastric acid secretion expressed as median (range) significantly during the first 30 minute period to 1.6 (0-5.2) mmol compared with 3.8 (2.3-14.5) mmol (p < 0.05) during control period (sham feeding without acupuncture). Inhibition of gastric acid secretion by electroacupuncture was also significant during the second 30 minute period (0.2 (0-5.6) v 3.6 (0.3-9.1) mmol; p < 0.05) and for peak acid output (0.8 (0.2-5.1) v 7.6 (3.4-12.1) mmol; p < 0.05). Transcutaneous electrical nerve stimulation also resulted in significant reduction of gastric acid secretion during the first 30 minute period (1.0 (0-3.6) mmol v 3.8 (2.3-14.5) mmol; p < 0.05), and peak acid output (3.6 (1.2-12.0) v 7.6 (3.4-12.1) mmol; p < 0.05). The classic needle acupuncture, laser acupuncture, and sham acupuncture had no significant effect on gastric acid secretion. This study shows firstly that in healthy volunteers, only the versions of acupuncture using more pronounced stimulation (electroacupuncture, transcutaneous electrical nerve stimulation), but not those with only mild stimulation of the nerves (classic needle acupuncture, laser acupuncture), and secondly only acupuncture performed at defined points lead to significant reduction in gastric acid secretion. PMID:7926899

  16. The release of histamine during gastric acid secretion in conscious rats

    PubMed Central

    el Munshid, H. A.; Lake, H. J.

    1974-01-01

    1. Conscious gastric-cannulated rats were given [3H]histidine and aminoguanidine by dosage procedures intended to build up fast-turnover and slow-turnover pools of tissue [3H]histamine. Acid secretion was stimulated by I.V. infusion of pentagastrin, and the [3H]histamine content of gastric juice and excretion in urine were determined at 30 min intervals. 2. The amount of [3H]histamine in gastric juice derived from either a slow-turnover or fast-turnover pool was very low in unstimulated animals, and was not altered during pentagastrin-stimulated acid secretion. 3. From a slow-turnover pool pentagastrin caused increased urinary excretion of [3H]histamine. This was abolished by gastrectomy, so that the [3H]histamine liberated by pentagastrin from this pool appears to have been derived from the stomach. Evidence was not found for the existence of a slow-turnover histamine pool in the glandular mucosa of the stomach, and the source within the stomach of this pentagastrin-liberated histamine is thus uncertain. 4. From a fast-turnover pool pentagastrin did not cause an increased urinary excretion of [3H]histamine. The amount of [3H]histamine excreted by gastrectomized rats was not different from that produced by gastric-cannulated animals. This suggests that a high proportion of urinary histamine derived from a fast-turnover pool was non-gastric in origin. 5. Differences in the time scale of [3H]histamine release and acid secretion were not found. In some experiments the urinary output of [3H]histamine was prolonged beyond the end of pentagastrin administration and gastric acid secretion. However, the overall data do not suggest that urinary histamine output and gastric acid secretion take different time courses. PMID:4141368

  17. Flexible and transparent gastric battery: energy harvesting from gastric acid for endoscopy application.

    PubMed

    Mostafalu, Pooria; Sonkusale, Sameer

    2014-04-15

    In this paper, we present the potential to harvest energy directly from the digestive system for powering a future wireless endoscopy capsule. A microfabricated electrochemical cell on flexible parylene film is proposed as a gastric battery. This electrochemical cell uses gastric juice as a source of unlimited electrolyte. Planar fabricated zinc [Zn] and palladium [Pd] electrodes serve as anode and cathode respectively. Due to planar geometry, no separator is needed. Moreover the annular structure of the electrodes provides lower distance between cathode and anode reducing the internal resistance. Both electrodes are biocompatible and parylene provides flexibility to the system. For a surface area of 15 mm(2), 1.25 mW is generated which is sufficient for most implantable endoscopy applications. Open circuit output voltage of this battery is 0.75 V. Since this gastric battery does not require any external electrolyte, it has low intrinsic weight, and since it is flexible and is made of biocompatible materials, it offers a promising solution for power in implantable applications. PMID:24287419

  18. Transcriptomic changes induced by mycophenolic acid in gastric cancer cells

    PubMed Central

    Dun, Boying; Sharma, Ashok; Xu, Heng; Liu, Haitao; Bai, Shan; Zeng, Lingwen; She, Jin-Xiong

    2014-01-01

    Background: Inhibition of inosine monophosphate dehydrogenase (IMPDH) by mycophenolic acid (MPA) can inhibit proliferation and induce apoptosis in cancer cells. This study investigated the underlying molecular mechanisms of MPA’s anticancer activity. Methods: A gastric cancer cell line (AGS) was treated with MPA and gene expression at different time points was analyzed using Illumina whole genome microarrays and selected genes were confirmed by real-time RT-PCR. Results: Transcriptomic profiling identified 1070 genes with ≥2 fold changes and 85 genes with >4 fold alterations. The most significantly altered biological processes by MPA treatment include cell cycle, apoptosis, cell proliferation and migration. MPA treatment altered at least ten KEGG pathways, of which eight (p53 signaling, cell cycle, pathways in cancer, PPAR signaling, bladder cancer, protein processing in ER, small cell lung cancer and MAPK signaling) are cancer-related. Among the earliest cellular events induced by MPA is cell cycle arrest which may be caused by six molecular pathways: 1) up-regulation of cyclins (CCND1 and CCNE2) and down-regulation of CCNA2 and CCNB1, 2) down-regulation of cyclin-dependent kinases (CDK4 and CDK5); 3) inhibition of cell division related genes (CDC20, CDC25B and CDC25C) and other cell cycle related genes (MCM2, CENPE and PSRC1), 4) activation of p53, which activates the cyclin-dependent kinase inhibitors (CDKN1A), 5) impaired spindle checkpoint function and chromosome segregation (BUB1, BUB1B, BOP1, AURKA, AURKB, and FOXM1); and 6) reduction of availability of deoxyribonucleotides and therefore DNA synthesis through down-regulation of the RRM1 enzyme. Cell cycle arrest is followed by inhibition of cell proliferation, which is mainly attributable to the inhibition of the PI3K/AKT/mTOR pathway, and caspase-dependent apoptosis due to up-regulation of the p53 and FAS pathways. Conclusions: These results suggest that MPA has beneficial anticancer activity through

  19. Low cost of gastric acid secretion during digestion in ball pythons.

    PubMed

    Nørgaard, Simon; Andreassen, Kim; Malte, Christian Lind; Enok, Sanne; Wang, Tobias

    2016-04-01

    Due to their large metabolic responses to digestion (specific dynamic action, SDA), snakes represent an interesting animal group to identify the underlying mechanisms for the postprandial rise in metabolism. The SDA response results from the energetic costs of many different processes ranging over prey handling, secretions by the digestive system, synthesis of enzymes, plasticity of most visceral organs, as well as protein synthesis and nitrogen excretion. The contribution of the individual mechanisms, however, remains elusive. Gastric acid secretion has been proposed to account for more than half of the SDA response, while other studies report much lower contributions of the gastric processes. To investigate the energetic cost of gastric acid secretion, ball pythons (Python regius) were fed meals with added amounts of bone meal (up to 25 g bone meal kg(-1) snake) to achieve a five-fold rise in the buffer capacity of the meals. Direct measurements within the stomach lumen showed similar reduction in gastric pH when buffer capacity was increased, but we found no effects on the rise in oxygen consumption over the first three days of digestion. There was, however, a slower return of oxygen consumption to resting baseline. We conclude that gastric acid secretion only contributes modestly to the SDA response and propose that post-absorptive processes, such as increased protein synthesis, are likely to underlie the SDA response. PMID:26802791

  20. Effects of calcium channel blockers on gastric emptying and acid secretion of the rat in vivo.

    PubMed Central

    Brage, R.; Cortijo, J.; Esplugues, J.; Esplugues, J. V.; Martí-Bonmatí, E.; Rodriguez, C.

    1986-01-01

    Experiments were designed to evaluate the effects of three calcium channel blockers (verapamil, diltiazem and cinnarizine) on gastric emptying and secretion in the rat. Pretreatment with the calcium blockers delayed gastric emptying of phenol red in a dose-dependent manner. Verapamil was the most effective of the agents tested. Verapamil and diltiazem inhibited gastric acid secretion in the pylorus-ligated rat without affecting pepsin output. Cinnarizine was ineffective in this model. When the perfused lumen of the anaesthetized rat was used, verapamil was found to inhibit responses to carbachol or histamine more than those to pentagastrin. Further, we found a greater sensitivity to verapamil for basal compared with vagal-stimulated (2-deoxy-D-glucose) acid secretion. Neither diltiazem nor cinnarizine modified gastric acid secretion in this experimental model. These findings are discussed in relation to the role of extracellular calcium in gastric motility and secretion, and the existence of a regional and functional selectivity for calcium blockers is proposed. PMID:3814903

  1. Dehydroabietic Acid Derivative QC4 Induces Gastric Cancer Cell Death via Oncosis and Apoptosis

    PubMed Central

    Luo, Dongjun; Ni, Qing; Ji, Anlai; Gu, Wen; Wu, Junhua

    2016-01-01

    Aim. QC4 is the derivative of rosin's main components dehydroabietic acid (DHA). We investigated the cytotoxic effect of QC4 on gastric cancer cells and revealed the mechanisms beneath the induction of cell death. Methods. The cytotoxic effect of QC4 on gastric cancer cells was evaluated by CCK-8 assay and flow cytometry. The underlying mechanisms were tested by administration of cell death related inhibitors and detection of apoptotic and oncosis related proteins. Cytomembrane integrity and organelles damage were confirmed by lactate dehydrogenase (LDH) leakage assay, mitochondrial function test, and cytosolic free Ca2+ concentration detection. Results. QC4 inhibited cell proliferation dose- and time-dependently and destroyed cell membrane integrity, activated calpain-1 autolysis, and induced apoptotic protein cleavage in gastric cancer cells. The detection of decreased ATP and mitochondrial membrane potential, ROS accumulation, and cytosolic free Ca2+ elevation confirmed organelles damage in QC4-treated gastric cancer cells. Conclusions. DHA derivative QC4 induced the damage of cytomembrane and organelles which finally lead to oncosis and apoptosis in gastric cancer cells. Therefore, as a derivative of plant derived small molecule DHA, QC4 might become a promising agent in gastric cancer therapy. PMID:27057539

  2. The Acid-Secreting Parietal Cell as an Endocrine Source of Sonic Hedgehog During Gastric Repair

    PubMed Central

    Engevik, Amy C.; Feng, Rui; Yang, Li

    2013-01-01

    Sonic Hedgehog (Shh) has been shown to regulate wound healing in various tissues. Despite its known function in tissue regeneration, the role of Shh secreted from the gastric epithelium during tissue repair in the stomach remains unknown. Here we tested the hypothesis that Shh secreted from the acid-secreting parietal cell is a fundamental circulating factor that drives gastric repair. A mouse model expressing a parietal cell-specific deletion of Shh (PC-ShhKO) was generated using animals bearing loxP sites flanking exon 2 of the Shh gene (Shhflx/flx) and mice expressing a Cre transgene under the control of the H+,K+-ATPase β-subunit promoter. Shhflx/flx, the H+,K+-ATPase β-subunit promoter, and C57BL/6 mice served as controls. Ulcers were induced via acetic acid injury. At 1, 2, 3, 4, 5, and 7 days after the ulcer induction, gastric tissue and blood samples were collected. Parabiosis experiments were used to establish the effect of circulating Shh on ulcer repair. Control mice exhibited an increased expression of Shh in the gastric tissue and plasma that correlated with the repair of injury within 7 days after surgery. PC-ShhKO mice showed a loss of ulcer repair and reduced Shh tissue and plasma concentrations. In a parabiosis experiment whereby a control mouse was paired with a PC-ShhKO littermate and both animals subjected to gastric injury, a significant increase in the circulating Shh was measured in both parabionts. Elevated circulating Shh concentrations correlated with the repair of gastric ulcers in the PC-ShhKO parabionts. Therefore, the acid-secreting parietal cell within the stomach acts as an endocrine source of Shh during repair. PMID:24092639

  3. Effective gastric acid suppression after oral administration of enteric-coated omeprazole granules.

    PubMed

    Mohiuddin, M A; Pursnani, K G; Katzka, D A; Gideon, R M; Castell, J A; Castell, D O

    1997-04-01

    Omeprazole is inactivated by exposure to gastric acid and is formulated as a gelatin capsule containing enteric-coated granules that release the drug in alkaline medium. In clinical situations where patients are unable to take the capsule orally, the optimum means of administration is uncertain. Eleven normal volunteers were given omeprazole 20 mg every day for one week before breakfast in random order as either a 20-mg capsule with water or free enteric-coated granules with either 8 oz of orange juice, 8 oz of water with 2 Alka-Seltzer antacid tablets (aspirin free), or 1 teaspoon of apple sauce. On day 7 of each regimen, an 8-hr intragastric pH study was performed following omeprazole 20 mg and standard breakfast. The median percentage of time of gastric acid pH > 4 after an omeprazole capsule was 68.5 (25-100); after granules with orange juice 59 (43-100); after granules in Alka-Seltzer solution 63 (31-100), and after granules in apple sauce 65 (30-99), with no significant differences (ANOVA). The time for the gastric pH to reach <4' after having been above was also similar for all four regimens (ANOVA). Omeprazole granules administered orally in a variety of ways achieve gastric acid suppression as effectively as the intact capsule. PMID:9125637

  4. Alpha-lipoic acid protects against indomethacin-induced gastric oxidative toxicity by modulating antioxidant system.

    PubMed

    Kaplan, Kursat Ali; Odabasoglu, Fehmi; Halici, Zekai; Halici, Mesut; Cadirci, Elif; Atalay, Fadime; Aydin, Ozlem; Cakir, Ahmet

    2012-11-01

    Gastroprotective effects of α-lipoic acid (ALA) against oxidative gastric damage induced by indomethacin (IND) have been investigated. All doses (50, 75, 100, 150, 200, and 300 mg/kg body weight) of ALA reduced the ulcer index with 88.2% to 96.1% inhibition ratio. In biochemical analyses of stomach tissues, ALA administration decreased the level of lipid peroxidation (LPO) and activities of myeloperoxidase (MPO) and catalase (CAT) in gastric tissues, which were increased after IND application. ALA also increased the level of glutathione (GSH) and activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) that were decreased in gastric damaged stomach tissues. In conclusion, the gastroprotective effect of ALA could be attributed to its ameliorating effect on the antioxidant defense systems. PMID:23057764

  5. Inhibition by somatostatin (growth-hormone release-inhibiting hormone, GH-RIH) of gastric acid and pepsin and G-cell release of gastrin.

    PubMed Central

    Barros D'sa, A A; Bloom, S R; Baron, J H

    1978-01-01

    Somatostatin (cyclic growth-hormone release-inhibiting hormone--GH-RIH) was infused into dogs with gastric fistulae. Somatostatin inhibited gastric acid response to four gastric stimulants--insulin, food, histamine, and pentagastrin. Histamine- and pentagastrin-stimulated pepsins were inhibited similarly to inhibition of acid. Somatostatin inhibited the gastrin response to insulin and food. PMID:348581

  6. Bile acid regulates c-Jun expression through the orphan nuclear receptor SHP induction in gastric cells

    SciTech Connect

    Park, Won Il; Park, Min Jung; An, Jin Kwang; Choi, Yung Hyun; Kim, Hye Young; Cheong, JaeHun Yang, Ung Suk

    2008-05-02

    Bile reflux is considered to be one of the most important causative factors in gastric carcinogenesis, due to the attendant inflammatory changes in the gastric mucosa. In this study, we have assessed the molecular mechanisms inherent to the contribution of bile acid to the transcriptional regulation of inflammatory-related genes. In this study, we demonstrated that bile acid induced the expression of the SHP orphan nuclear receptor at the transcriptional level via c-Jun activation. Bile acid also enhanced the protein interaction of NF-{kappa}B and SHP, thereby resulting in an increase in c-Jun expression and the production of the inflammatory cytokine, TNF{alpha}. These results indicate that bile acid performs a critical function in the regulation of the induction of inflammatory-related genes in gastric cells, and that bile acid-mediated gene expression provides a pre-clue for the development of gastric cellular malformation.

  7. Elemental composition of dog foods using nitric acid and simulated gastric digestions.

    PubMed

    Kelly, David G; White, Steven D; Weir, Ron D

    2013-05-01

    Eighteen dry dog foods obtained commercially in the United States were digested using microwave assisted nitric acid digestion and a simulated gastric digestion. Digests were analysed for 23 elements using inductively coupled plasma-mass spectrometry. Data, expressed as dry matter concentrations, were compared to published nitric acid digestion results. Nitric acid data obtained in the present study were not statistically different from published data, with the exception of Mo, Sn, Sb, Tl and Th. However, significant differences in individual intra-sample results were observed between published studies and the present work. Simulated gastric digestions demonstrated lower extraction efficiencies (<50% nitric acid digestions) that were statistically significant. Much lower bioavailability was observed for Al, Ba and Pb. In general, elemental concentrations were determined to be lower than the appropriate Mineral Tolerance Limit or consistent with background concentrations in foodstuffs. Evaluation against Reference Doses (RfDs) showed concentrations for many elements obtained by nitric acid digestion to be above RfD levels. However, the respective simulated gastric digestion data were below or only moderately elevated above RfDs. Only arsenic displayed median and maximum concentrations at factors of five and ten above the relevant RfD. PMID:23402861

  8. Clinical applications of 5-aminolevulinic acid-mediated fluorescence for gastric cancer

    PubMed Central

    Namikawa, Tsutomu; Yatabe, Tomoaki; Inoue, Keiji; Shuin, Taro; Hanazaki, Kazuhiro

    2015-01-01

    5-aminolevulinic acid (ALA) is a naturally occurring amino acid that is a protoporphyrin IX (PpIX) precursor and a next-generation photosensitive substance. After exogenous administration of ALA, PpIX specifically accumulates in cancer cells owing to the impaired metabolism of ALA to PpIX in mitochondria, which results in a red fluorescence following irradiation with blue light and the formation of singlet oxygen. Fluorescence navigation by photodynamic diagnosis (PDD) using ALA provides good visualization and detection of gastric cancer lesions and is a potentially valuable diagnostic tool for gastric cancer for evaluating both the surgical resection margins and extension of the lesion. Furthermore, PDD using ALA might be used to detect peritoneal metastases during preoperative staging laparoscopy, where it could provide useful information for the selection of a therapeutic approach. Another promising application for this modality is in the evaluation of lymph node metastases. Photodynamic therapy (PDT) using ALA to cause selective damage based on the accumulation of a photosensitizer in malignant tissue is expected to be a non-invasive endoscopic treatment for superficial early gastric cancer. ALA has the potential to be used not only as a diagnostic agent but also as a therapeutic drug, resulting in a new strategy for cancer diagnosis and therapy. Here, we review the current use of PDD and PDT in gastric cancer and evaluate its future potential beyond conventional modalities combined with a light energy upconverter, a light-emitting diode and near-infrared rays as light sources. PMID:26269666

  9. Gastric mucosal blood flow during pentagastrin- and histamine-stimulated acid secretion in the rat

    PubMed Central

    Main, I. H. M.; Whittle, B. J. R.

    1973-01-01

    1. Gastric mucosal blood flow was studied in the rat by means of a [14C]-aniline clearance technique. 2. There was a significant correlation between clearance and stimulated acid secretion. 3. No significant difference was found in the relationship between clearance and acid secretion during submaximal stimulation with either pentagastrin or histamine. 4. Estimates of mucosal blood flow per unit acid secretion by [14C]-aniline clearance in the rat were similar to those reported with aminopyrine clearance in the dog and cat. PMID:4777713

  10. Effect of Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding on branched-chain amino acid metabolism.

    PubMed

    Magkos, Faidon; Bradley, David; Schweitzer, George G; Finck, Brian N; Eagon, J Christopher; Ilkayeva, Olga; Newgard, Christopher B; Klein, Samuel

    2013-08-01

    It has been hypothesized that a greater decline in circulating branched-chain amino acids (BCAAs) after weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery than after calorie restriction alone has independent effects on glucose homeostasis, possibly by decreased signaling through the mammalian target of rapamycin (mTOR). We evaluated plasma BCAAs and their C3 and C5 acylcarnitine metabolites, muscle mTOR phosphorylation, and insulin sensitivity (insulin-stimulated glucose Rd) in obese subjects before and after ~20% weight loss induced by RYGB (n = 10, BMI 45.6 ± 6.7 kg/m(2)) or laparoscopic adjustable gastric banding (LAGB) (n = 10, BMI 46.5 ± 8.8 kg/m(2)). Weight loss increased insulin-stimulated glucose Rd by ~55%, decreased total plasma BCAA and C3 and C5 acylcarnitine concentrations by 20-35%, and did not alter mTOR phosphorylation; no differences were detected between surgical groups (all P values for interaction >0.05). Insulin-stimulated glucose Rd correlated negatively with plasma BCAAs and with C3 and C5 acylcarnitine concentrations (r values -0.56 to -0.75, P < 0.05). These data demonstrate that weight loss induced by either LAGB or RYGB causes the same decline in circulating BCAAs and their C3 and C5 acylcarnitine metabolites. Plasma BCAA concentration is negatively associated with skeletal muscle insulin sensitivity, but the mechanism(s) responsible for this relationship is not known. PMID:23610059

  11. Upregulation of bile acid receptor TGR5 and nNOS in gastric myenteric plexus is responsible for delayed gastric emptying after chronic high-fat feeding in rats.

    PubMed

    Zhou, Hui; Zhou, Shiyi; Gao, Jun; Zhang, Guanpo; Lu, Yuanxu; Owyang, Chung

    2015-05-15

    Chronic high-fat feeding is associated with functional dyspepsia and delayed gastric emptying. We hypothesize that high-fat feeding upregulates gastric neuronal nitric oxide synthase (nNOS) expression, resulting in delayed gastric emptying. We propose this is mediated by increased bile acid action on bile acid receptor 1 (TGR5) located on nNOS gastric neurons. To test this hypothesis, rats were fed regular chow or a high-fat diet for 2 wk. Rats fed the high-fat diet were subjected to concurrent feeding with oral cholestyramine or terminal ileum resection. TGR5 and nNOS expression in gastric tissue was measured by immunohistochemistry, PCR, and Western blot. Gastric motility was assessed by organ bath and solid-phase gastric emptying studies. The 2-wk high-fat diet caused a significant increase in neurons coexpressing nNOS and TGR5 in the gastric myenteric plexus and an increase in nNOS and TGR5 gene expression, 67 and 111%, respectively. Enhanced nonadrenergic, noncholinergic (NANC) relaxation, deoxycholic acid (DCA)-induced inhibition in fundic tissue, and a 26% delay in gastric emptying accompanied these changes. A 24-h incubation of whole-mount gastric fundus with DCA resulted in increased nNOS and TGR5 protein expression, 41 and 37%, respectively. Oral cholestyramine and terminal ileum resection restored the enhanced gastric relaxation, as well as the elevated nNOS and TGR5 expression evoked by high-fat feeding. Cholestyramine also prevented the delay in gastric emptying. We conclude that increased levels of circulatory bile acids induced by high-fat feeding upregulate nNOS and TGR5 expression in the gastric myenteric plexus, resulting in enhanced NANC relaxation and delayed gastric emptying. PMID:25540233

  12. Effects of carnitine and its derivatives on gastric acid secretion in rats.

    PubMed

    Valoti, M; Benocci, A; Marazova, K; Mantovani, P

    1996-01-01

    Carnitine is a natural substance that acts as a carrier of fatty-acids across the inner mitochondrial membrane for subsequent beta-oxidation. Acetyl-L-carnitine is the acetyl derivative of L-carnitine that has been shown to possess a slight cholinomimetic activity. Its success in sports medicine is dependent on the fact that it is able to stimulate the central nervous system functions. This study aims to investigate the effects of L-carnitine (LC) and its derivatives-acetyl-L-carnitine (ALC) and propionyl-L-carnitine (PLC)-on gastric acid secretion in rats. A concentration-dependent relationship with both ALC or PLC was observed in experiments in vitro using a rat isolated stomach. The addition of atropine to the perfusion bath only partially antagonized the effects of the two compounds. Stimulation of gastric acid secretion in a dose-dependent manner was also found when the tested compounds were administered i.v. to anaesthetized rats. To elucidate the mechanism of the gastric secretory response, assay for acetylcholine esterase activity using acetylthiocholine as substrate, was performed. It was found that ALC and PLC inhibited acetylcholine esterase, however, the IC50 for both compounds was about four times of magnitude greater than that of eserine. As the increase of the gastric acid secretion promoted by carnitines was blocked only partially by atropine both in vitro and in vivo, whilst it was completely abolished by experimental degeneration of the sympathetic neurons or by blockade of the postsynaptic sympathetic receptors, it is suggested that the effect of carnitines is determined by cholinergic and partly by adrenergic mechanisms. PMID:9076846

  13. The potential influence of gastric acid secretion during fasting on digestion time in leopard sharks (Triakis semifasciata).

    PubMed

    Papastamatiou, Yannis P

    2007-05-01

    Vertebrates are known to differ in their response of gastric acid secretion during periods of fasting, yet the reasons for these differences remain unclear. Previously, continuous measurements of gastric pH in leopard sharks (Triakis semifasciata) had determined that acid secretion in this species is continuous. In order to determine if maintaining an empty acidic stomach may reduce digestion time of a subsequent meal, a simple descriptive model based on acid secretion rates was developed. In vivo gastric acid secretion rates were measured using an auto-titration technique. Acid secretion rates were pH dependent, with rates of 6.1+/-3.0 (+/-1 SD) mmol/h when gastric pH was >2.5, and 1.7+/-0.8 mmol/h when pH was 2.0-2.5. Analysis by Western blots suggests that pepsin secretion occurs within 1 h of feeding, and that there is a de-coupling of acid and pepsin secretion. The model estimates that digestion time can be reduced by 5.7+/-1.3 h and pepsin activity increased by 10-100% during that time if the stomach is acidic before feeding. Gastric acid secretion during fasting is hypothesized to reduce digestion time of a subsequent meal in frequently feeding sharks, which may be advantageous for exploiting resources that are spatially and temporally unpredictable. PMID:17280858

  14. Quality of healing of gastric ulcers: Natural products beyond acid suppression

    PubMed Central

    Kangwan, Napapan; Park, Jong-Min; Kim, Eun-Hee; Hahm, Ki Baik

    2014-01-01

    Gastric ulcer is a chronic disease featured with unexpected complications, including bleeding, stenosis and perforation, as well as a high incidence of recurrence. Clinical treatments for gastric ulcer have allowed the rapid development of potent anti-ulcer drugs during the last several decades. Gastric ulcer healing is successful with conventional treatments including H2-receptor antagonists, and proton pump inhibitors (PPIs) have been essential for ulcer healing and prevention of complications. Additionally, Helicobacter pylori eradication therapy is effective in reducing ulcer recurrence and leads to physiological changes in the gastric mucosa which affect the ulcer healing process. However, in spite of these advancements, some patients have suffered from recurrence or intractability in spite of continuous anti-ulcer therapy. A new concept of the quality of ulcer healing (QOUH) was initiated that considers the reconstruction of the mucosal structure and its function for preventing ulcer recurrence. Although several gastroprotection provided these achievements of the QOUH, which PPI or other acid suppressants did not accomplish, we found that gastroprotection that originated from natural products, such as a newer formulation from either Artemisia or S-allyl cysteine from garlic, were very effective in the QOUH, as well as improving clinical symptoms with fewer side effects. In this review, we will introduce the importance of the QOUH in ulcer healing and the achievements from natural products. PMID:24891974

  15. Amino acid synthesis in Europa's subsurface environment

    NASA Astrophysics Data System (ADS)

    Abbas, Sam H.; Schulze-Makuch, Dirk

    2008-10-01

    It has been suggested that Europa's subsurface environment may provide a haven for prebiotic evolution and the development of exotic biotic systems. The detection of hydrogen peroxide, sulfuric acid, water, hydrates and related species on the surface, coupled with observed mobility of icebergs, suggests the presence of a substantial subsurface liquid reservoir that actively exchanges materials with the surface environment. The atmospheric, surface and subsurface environments are described with their known chemistry. Three synthetic schemes using hydrogen peroxide, sulfuric acid and hydrocyanic acid leading to the production of larger biologically important molecules such as amino acids are described. Metabolic pathways based on properties of the subsurface ocean environment are detailed. Tidal heating, osmotic gradients, chemical cycling, as well as hydrothermal vents, provide energy and materials that may support a course of prebiotic evolution leading to the development or sustenance of simple biotic systems. Putative organisms may employ metabolic pathways based on chemical oxidation reduction cycles occurring in the putative subsurface ocean environment.

  16. Histidine decarboxylase and urinary methylimidazoleacetic acid in gastric neuroendocrine cells and tumours

    PubMed Central

    Tsolakis, Apostolos V; Grimelius, Lars; Granerus, Göran; Stridsberg, Mats; Falkmer, Sture E; Janson, Eva T

    2015-01-01

    AIM: To study histidine decarboxylase (HDC) expression in normal and neoplastic gastric neuroendocrine cells in relationship to the main histamine metabolite. METHODS: Control tissues from fundus (n = 3) and corpus (n = 3) mucosa of six patients undergoing operations for gastric adenocarcinoma, biopsy and/or gastric surgical specimens from 64 patients with primary gastric neuroendocrine tumours (GNETs), as well as metastases from 22 of these patients, were investigated using conventional immunohistochemistry and double immunofluorescence with commercial antibodies vs vesicular monoamine transporter 2 (VMAT-2), HDC and ghrelin. The urinary excretion of the main histamine metabolite methylimidazoleacetic acid (U-MeImAA) was determined using high-performance liquid chromatography in 27 of the 64 patients. RESULTS: In the gastric mucosa of the control tissues, co-localization studies identified neuroendocrine cells that showed immunoreactivity only to VMAT-2 and others with reactivity only to HDC. A third cell population co-expressed both antigens. There was no co-expression of HDC and ghrelin. Similar results were obtained in the foci of neuroendocrine cell hyperplasia associated with chronic atrophic gastritis type A and also in the tumours. The relative incidence of the three aforementioned markers varied in the tumours that were examined using conventional immunohistochemistry. All of these GNETs revealed both VMAT-2 and HDC immunoreactivity, and their metastases showed an immunohistochemical pattern and frequency similar to that of their primary tumours. In four patients, increased U-MeImAA excretion was detected, but only two of the patients exhibited related endocrine symptoms. CONCLUSION: Human enterochromaffin-like cells appear to partially co-express VMAT-2 and HDC. Co-expression of VMAT-2 and HDC might be required for increased histamine production in patients with GNETs. PMID:26715806

  17. Evaluation of the efficacy of Alka-Seltzer Effervescent in gastric acid neutralization.

    PubMed

    Chen, C T; Toung, T J; Haupt, H M; Hutchins, G M; Cameron, J L

    1984-03-01

    A commercially available antacid, a mixture of sodium and potassium bicarbonates and citric acid (Alka-Seltzer Effervescent), was evaluated experimentally and clinically for its efficacy in neutralizing 0.1 N HCl and gastric contents. In an in vitro titration study, Alka-Seltzer Effervescent buffered 5-30 times the volume of HCl with a pH between 1.0 and 2.0 to above a pH of 2.5. In an isolated canine pulmonary lobe model, aspiration of the antacid or acid-antacid mixture caused only a mild increase in lobe weight and did not increase intrapulmonary shunting. In the clinical study, when the antacid was given 5-40 min before administration of general anesthesia in a group of patients for emergency surgery, the pH of the gastric contents in each patient was increased to above 4.0. This contrasts with the control group of patients, which showed 50% (P less than 0.05) of the patients were at risk when no antacid was administered. Preoperative administration of Alka-Seltzer effectively increases the pH of the gastric contents in patients undergoing emergency surgery. PMID:6703349

  18. Recent advances in photodynamic diagnosis of gastric cancer using 5-aminolevulinic acid

    PubMed Central

    Koizumi, Noriaki; Harada, Yoshinori; Minamikawa, Takeo; Tanaka, Hideo; Otsuji, Eigo; Takamatsu, Tetsuro

    2016-01-01

    Photodynamic diagnosis based on 5-aminolevulinic acid-induced protoporphyrin IX has been clinically applied in many fields based upon its evidenced efficacy and adequate safety. In order to establish a personalized medicine approach for treating gastric cancer patients, rapid intraoperative detection of malignant lesions has become important. Feasibility of photodynamic diagnosis using 5-aminolevulinic acid for gastric cancer patients has been investigated, especially for the detection of peritoneal dissemination and lymph node metastasis. This method enables intraoperative real-time fluorescence detection of peritoneal dissemination, exhibiting higher sensitivity than white light observation without histopathological examination. The method also enables detection of metastatic foci within excised lymph nodes, exhibiting a diagnostic accuracy comparable to that of a current molecular diagnostics technique. Although several complicating issues still need to be resolved, such as the effect of tissue autofluorescence and the insufficient depth penetration of excitation light, this simple and rapid method has the potential to become a useful diagnostic tool for gastric cancer, as well as urinary bladder cancer and glioma. PMID:26811665

  19. Low dose omeprazole effects on gastric acid secretion in normal man.

    PubMed

    Hemery, P; Galmiche, J P; Roze, C; Isal, J P; Bruley des Varannes, S; Lavignolle, A; Le Bodic, L

    1987-02-01

    The pharmacological effects of low dose of omeprazole (Om) are not well known. This prompted us to investigate the effects of a 7-day treatment with a low dose of Om, 10 mg/d (Om10), on gastric acid secretion and serum gastrin levels and to compare the results with those obtained with an effective antisecretory dose of 20 mg/d (Om20). Twelve healthy volunteers received randomly and double-blind for three periods of 7 days, separated by at least 7 days, one capsule of placebo (P), Om10, Om20, given daily in the morning, in fasting condition. The last day of each period, 24 h pH was recorded using a glass electrode connected to a Digitrapper (Synectics). At the end of each pH-metry, acid secretion was measured in basal conditions (BAO), after sham-feeding (SAO) and after i.m. injection of 6 micrograms X kg-1 of pentagastrin (PAO). Whatever the threshold pH chosen, there was a statistically significant difference between P and Om10, P and Om20, and Om10 and Om20. Inhibition of acid concentrations was dose-dependent and prolonged, including nocturnal time. However, when considered on an individual basis, five subjects did not respond to Om10. More than 24 h after the last dose of Om has been administered, BAO, SAO and PAO were significantly reduced by either Om10 (respectively -52, -35 and -28 p. cent) and Om20 (respectively -60, -58 and -50 p. cent). Fasting serum gastrin concentration was significantly increased after Om20 treatment but not after Om10. We conclude that treatment with Om10 has a consistent and long lasting inhibitory action on gastric acidity without statistically significant effect on serum gastrin levels. These results suggest that 10 mg Om daily should be sufficient in some duodenal ulcer patients to effectively inhibit gastric acidity specially when long-term treatment seems to be indicated. PMID:3569737

  20. Augmentation of gastric acid secretion by chloroquine and amodiaquine in the rat stomach.

    PubMed

    Ajeigbe, K O; Emikpe, B O; Olaleye, S B

    2012-06-01

    Gastrointestinal mucosal integrity has been shown to be altered by chloroquine and amodiaquine, although the exact mechanism is not clear. Since Gastric Acid Secretion (GAS) plays significant role in the etiology of ulcer, the present study was aimed at investigating the effect of chloroquine and amodiaquine on GAS, Parietal Cell Mass (PCM) and Gastric Mucous Cell Population (GMP) in rats. Male albino wistar rats were randomly assigned into three groups viz: control, chloroquine (CQ, 3 mg/kg), amodiaquine (AQ, 10 mg/kg). Basal GAS as well as secretion in response to histamine and carbachol was measured by continuous perfusion of the stomach with normal saline (1ml/minute) under urethane anaesthesia (0.6 mg/100 g). After obtaining a steady basal output response to normal saline in all animals, the antimalaria drugs were administered intramuscularly and the peak responses to each drug obtained. Further assessment of the roles of histaminergic and muscarinic receptors were done using ranitidine (H2 antagonist) and atropine (M antagonist) in the treated animals. PCM and GMP were determined in the stomach samples by histometry. The basal acid output was 0.70 ± 0.01 mmol/10 mins. Chloroquine and amodiaquine produced increase in acid output to a peak of 1.35 ±0.03 mmol/10 mins (92.9%) and 1.40 ± 0.03 mmol/10 mins (100%) respectively. Histamine and carbachol elicited 107% and 100% increase acid secretion when compared with the basal output respectively. CQ and AQ potentiated histamine-induced secretory rate which peaked at 1.60 ± 0.02 mmol/10 mins and 1.70 ± 0.03 mmol/10 mins respectively. Similarly, the carbachol-induced acid secretory response was potentiated by CQ and AQ to a peak of 1.45 ± 0.02 mmol/10 mins and 1.50 ± 0.03 mmol/10 mins. Ranitidine and atropine attenuated histamine and carbachol induced acid secretion, but did not abolish it. CQ and AQ increased significantly the parietal cell numbers in the gastric mucosa (21±0.7 and 24±0.7 versus 15.2±0

  1. (Acidic deposition and the environment)

    SciTech Connect

    Garten, C.T.; Lindberg, S.E.; Van Miegroet, H.

    1990-10-24

    The travelers presented several papers at the Fourth International Conference on Acidic Deposition. These covered the following topics: atmospheric chemistry and deposition of airborne nitrogen compounds, soil solution chemistry in high-elevation spruce forests, and forest throughfall measurements for estimating total sulfur deposition to ecosystems. In addition, S. E. Lindberg was invited to organize and chair a conference session on Throughfall and Stemflow Experiments, and to present an invited lecture on Atmospheric Deposition and Canopy Interactions of Metals and Nitrogen in Forest Ecosystems: The Influence of Global Change'' at the 110th Anniversary Celebration of the Free University of Amsterdam.

  2. Effect of netazepide, a gastrin/CCK2 receptor antagonist, on gastric acid secretion and rabeprazoleinduced hypergastrinaemia in healthy subjects

    PubMed Central

    Boyce, Malcolm; Dowen, Sally; Turnbull, Gillian; van den Berg, Frans; Zhao, Chun-Mei; Chen, Duan; Black, James

    2015-01-01

    Aims To compare gastric acid suppression by netazepide, a gastrin/CCK2 receptor antagonist, with that by a proton pump inhibitor (PPI), and to determine if netazepide can prevent the trophic effects of PPI-induced hypergastrinaemia. Methods Thirty healthy subjects completed a double-blind, randomized, parallel group trial of oral netazepide and rabeprazole, alone and combined, once daily for 6 weeks. Primary end points were: basal and pentagastrin-stimulated gastric acid and 24 h circulating gastrin and chromogranin A (CgA) at baseline, start and end of treatment, gastric biopsies at baseline and end of treatment and basal and pentagastrin-stimulated gastric acid and dyspepsia questionnaire after treatment withdrawal. Results All treatments similarly inhibited pentagastrin-stimulated gastric acid secretion. All treatments increased serum gastrin, but the combination and rabeprazole did so more than netazepide alone. The combination also reduced basal acid secretion. Rabeprazole increased plasma CgA, whereas netazepide and the combination reduced it. None of the biopsies showed enterochromaffin-like (ECL) cell hyperplasia. Withdrawal of treatments led neither to rebound hyperacidity nor dyspepsia. Conclusions Netazepide suppressed pentagastrin-stimulated gastric acid secretion as effectively as did rabeprazole. The reduction in basal acid secretion and greater increase in serum gastrin by the combination is consistent with more effective acid suppression. Despite our failure to show rabeprazole-induced ECL cell hyperplasia and rebound hyperacidity, the increase in plasma CgA after rabeprazole is consistent with a trophic effect on ECL cells, which netazepide prevented. Thus, netazepide is a potential treatment for the trophic effects of hypergastrinaemia and, with or without a PPI, is a potential treatment for acid-related conditions. PMID:25335860

  3. Elevated dietary linoleic acid increases gastric carcinoma cell invasion and metastasis in mice

    PubMed Central

    Matsuoka, T; Adair, J E; Lih, F B; Hsi, L C; Rubino, M; Eling, T E; Tomer, K B; Yashiro, M; Hirakawa, K; Olden, K; Roberts, J D

    2010-01-01

    Background: Dietary (n-6)-polyunsaturated fatty acids influence cancer development, but the mechanisms have not been well characterised in gastric carcinoma. Methods: We used two in vivo models to investigate the effects of these common dietary components on tumour metastasis. In a model of experimental metastasis, immunocompromised mice were fed diets containing linoleic acid (LA) at 2% (LLA), 8% (HLA) or 12% (VHLA) by weight and inoculated intraperitoneally (i.p.) with human gastric carcinoma cells (OCUM-2MD3). To model spontaneous metastasis, OCUM-2MD3 tumours were grafted onto the stomach walls of mice fed with the different diets. In in vitro assays, we investigated invasion and ERK phosphorylation of OCUM-2MD3 cells in the presence or absence of LA. Finally, we tested whether a cyclooxygenase (COX) inhibitor, indomethacin, could block peritoneal metastasis in vivo. Results: Both the HLA and VHLA groups showed increased incidence of tumour nodules (LA: 53% HLA: 89% VHLA: 100% P<0.03); the VHLA group also displayed increased numbers of tumour nodules and higher total volume relative to LLA group in experimental metastasis model. Both liver invasion (78%) and metastasis to the peritoneal cavity (67%) were more frequent in VHLA group compared with the LLA group (22% and 11%, respectively; P<0.03) in spontaneous metastasis model. We also found that the invasive ability of these cells is greatly enhanced when exposed to LA in vitro. Linoleic acid also increased invasion of other scirrhous gastric carcinoma cells, OCUM-12, NUGC3 and MKN-45. Linoleic acid effect on OCUM-2MD3 cells seems to be dependent on phosphorylation of ERK. The data suggest that invasion and phosphorylation of ERK were dependent on COX. Indomethacin decreased the number of tumours and total tumour volume in both LLA and VHLA groups. Finally, COX-1, which is known to be an important enzyme in the generation of bioactive metabolites from dietary fatty acids, appears to be responsible for the

  4. Genetic Ablation of the ClC-2 Cl- Channel Disrupts Mouse Gastric Parietal Cell Acid Secretion

    PubMed Central

    Nighot, Meghali P.; Nighot, Prashant K.; Ma, Thomas Y.; Malinowska, Danuta H.; Shull, Gary E.; Cuppoletti, John; Blikslager, Anthony T.

    2015-01-01

    The present studies were designed to examine the effects of ClC-2 ablation on cellular morphology, parietal cell abundance, H/K ATPase expression, parietal cell ultrastructure and acid secretion using WT and ClC-2-/- mouse stomachs. Cellular histology, morphology and proteins were examined using imaging techniques, electron microscopy and western blot. The effect of histamine on the pH of gastric contents was measured. Acid secretion was also measured using methods and secretagogues previously established to give maximal acid secretion and morphological change. Compared to WT, ClC-2-/- gastric mucosal histological organization appeared disrupted, including dilation of gastric glands, shortening of the gastric gland region and disorganization of all cell layers. Parietal cell numbers and H/K ATPase expression were significantly reduced by 34% (P<0.05) and 53% (P<0.001) respectively and cytoplasmic tubulovesicles appeared markedly reduced on electron microscopic evaluation without evidence of canalicular expansion. In WT parietal cells, ClC-2 was apparent in a similar cellular location as the H/K ATPase by immunofluorescence and appeared associated with tubulovesicles by immunogold electron microscopy. Histamine-stimulated [H+] of the gastric contents was significantly (P<0.025) lower by 9.4 fold (89%) in the ClC-2-/- mouse compared to WT. Histamine/carbachol stimulated gastric acid secretion was significantly reduced (range 84–95%, P<0.005) in ClC-2-/- compared to WT, while pepsinogen secretion was unaffected. Genetic ablation of ClC-2 resulted in reduced gastric gland region, reduced parietal cell number, reduced H/K ATPase, reduced tubulovesicles and reduced stimulated acid secretion. PMID:26378782

  5. In vivo inhibition of gastric acid secretion by the aqueous extract of Scoparia dulcis L. in rodents.

    PubMed

    Mesía-Vela, Sonia; Bielavsky, Monica; Torres, Luce Maria Brandão; Freire, Sonia Maria; Lima-Landman, Maria Teresa R; Souccar, Caden; Lapa, Antonio José

    2007-05-01

    The freeze-dried aqueous extract (AE) from the aerial parts of Scoparia dulcis was tested for its effects on experimental gastric hypersecretion and ulcer in rodents. Administration of AE to animals with 4h pylorus ligature potently reduced the gastric secretion with ED(50)s of 195 mg/kg (rats) and 306 mg/kg (mice). The AE also inhibited the histamine- or bethanechol-stimulated gastric secretion in pylorus-ligated mice with similar potency suggesting inhibition of the proton pump. Bio-guided purification of the AE yielded a flavonoid-rich fraction (BuF), with a specific activity 4-8 times higher than the AE in the pylorus ligature model. BuF also inhibited the hydrolysis of ATP by H(+),K(+)-ATPase with an IC(50) of 500 microg/ml, indicating that the inhibition of gastric acid secretion of Scoparia dulcis is related to the inhibition of the proton pump. Furthermore, the AE inhibited the establishment of acute gastric lesions induced in rats by indomethacin (ED(50)=313 mg/kg, p.o.) and ethanol (ED(50)=490 mg/kg, p.o.). No influence of the AE on gastrointestinal transit allowed discarding a possible CNS or a cholinergic interaction in the inhibition of gastric secretion by the AE. Collectively, the present data pharmacologically validates the popular use of Scoparia dulcis in gastric disturbances. PMID:17300892

  6. Gastric tissue biopsy and culture

    MedlinePlus

    Culture - gastric tissue; Biopsy - gastric tissue ... of organisms that cause infection. A gastric tissue culture may be considered normal if it does not show certain bacteria. Stomach acids normally prevent too much bacteria from growing.

  7. Teaching the Role of Secretin in the Regulation of Gastric Acid Secretion Using a Classic Paper by Johnson and Grossman

    ERIC Educational Resources Information Center

    Walton, Kristen L. W.

    2009-01-01

    The regulation of gastric acid secretion has been the subject of investigation for over a century. Inhibition of gastrin-induced acid secretion by the intestine-derived hormone secretin provides a classic physiological example of negative feedback in the gastrointestinal tract. A classic paper by Leonard R. Johnson and Morton I. Grossman clearly…

  8. Effect of gastric acid suppressants and prokinetics on peritoneal dialysis-related peritonitis

    PubMed Central

    Kwon, Ji Eun; Koh, Seong-Joon; Chun, Jaeyoung; Kim, Ji Won; Kim, Byeong Gwan; Lee, Kook Lae; Im, Jong Pil; Kim, Joo Sung; Jung, Hyun Chae

    2014-01-01

    AIM: To investigate the effect of gastric acid suppressants and prokinetics on peritonitis development in peritoneal dialysis (PD) patients. METHODS: This was a single-center, retrospective study. The medical records of 398 PD patients were collected from January 2000 to September 2012 and analyzed to compare patients with at least one episode of peritonitis (peritonitis group, group A) to patients who never had peritonitis (no peritonitis group, group B). All peritonitis episodes were analyzed to compare peritonitis caused by enteric organisms and peritonitis caused by non-enteric organisms. RESULTS: Among the 120 patients who met the inclusion criteria, 61 patients had at least one episode of peritonitis and 59 patients never experienced peritonitis. Twenty-four of 61 patients (39.3%) in group A and 15 of 59 patients (25.4%) in group B used gastric acid suppressants. Only the use of H2-blocker (H2B) was associated with an increased risk of PD-related peritonitis; the use of proton pump inhibitors, other antacids, and prokinetics was not found to be a significant risk factor for PD-related peritonitis. A total of 81 episodes of peritonitis were divided into enteric peritonitis (EP) or non-enteric peritonitis, depending on the causative organism, and gastric acid suppressants and prokinetics did not increase the risk of EP in PD patients. CONCLUSION: The use of H2B showed a trend for an increased risk of overall PD-related peritonitis, although further studies are required to clarify the effects of drugs on PD-related peritonitis. PMID:25057226

  9. Inhibition of gastric acid secretion by the aqueous extract and purified extracts of Stachytarpheta cayennensis.

    PubMed

    Vela, S M; Souccar, C; Lima-Landman, M T; Lapa, A J

    1997-02-01

    Stachytarpheta cayennensis Schauer (Verbenaceae) is used in folk medicine to treat gastric and intestinal disturbances. The freeze-dried aqueous extract of the whole plant tested to rodents up to the dose of 2 g kg-1, p.o., did not produce signs of toxicity. The extract (0.5-2 g kg-1, p.o.) increased the intestinal motility and protected mice against ulcers induced by restraintin-cold, ethanol or indomethacin. Injected into the duodenal lumen the extract inhibited the basal acid secretion as well as that induced by histamine and bethanecol in pylorus-ligated mice. Partition of the aqueous extract in organic solvents yielded semipurified fractions whose antiacid activity guided further chemical purification. All the fractions were chromatographically characterized, the main substances in the active extract being flavonoids and amines; some substances were revealed only under UV light. The most purified active fraction obtained presented a specific activity 5-10 times higher than that detected in the original extract. Data from pharmacological studies indicate that the antiulcer activity of S. cayennensis is related to a specific inhibition of gastric acid secretion. Cholinergic and histaminergic stimulation of acid secretion were similarly reduced by the extracts suggesting inhibition of common steps in both pathways, possibly at the level of histamine release/H2 receptor interaction, or at the proton pump. Whatever the mechanisms involved, the present data confirm the plant effectiveness as antiacid/antiulcer and laxative. PMID:9063095

  10. Effects of L-glutamine on acetylsalycylic acid induced gastric lesions and acid back diffusion in dogs.

    PubMed

    Hung, C R; Takeuchi, K; Okabe, S; Murata, T; Takagi, K

    1976-12-01

    Effects of L-glutamine on acetylsalicylic acid (ASA)-induced gastric mucosal lesions were studied in mongrel dogs. It was confirmed that when oral ASA at 1.0 or 2.0 g per dog is given in two divided doses, there is severe and consistent dose-dependent mucosal damage in the glandular portion of the stomach in fasted dogs. However, when L-glutamine 2.0 or 4.0 g per dog in two divided doses is given concomitantly with ASA 2.0 g per dog orally, the gastric irritation is significantly inhibited. Instillation of 20 mM of ASA in 100 mM HCl solution into the Heidenhain pouch of Beagle dogs produced a significant loss of H+ from the pouch and a gain of Na+ in the lumen compared with ASA-free controls. When L-glutamine (100 mM) was given concomitantly with ASA (20 mM) into the pouch, changes of electrolyte fluxes in response to ASA alone were significantly suppressed. However, 50 mM of L-glutamine had no appreciable effect on acid back diffusion caused by ASA 20 mM. The amino acid itself had little effect on the ionic movement in the pouch. Gross bleeding from the pouch treated with ASA was never observed with the concomitant dosing of ASA and L-glutamine 50 or 100 mM. PMID:15154

  11. Inhibition of gastric acid secretion by stress: A protective reflex mediated by cerebral nitric oxide

    PubMed Central

    Esplugues, J. V.; Barrachina, M. D.; Beltrán, B.; Calatayud, S.; Whittle, B. J. R.; Moncada, S.

    1996-01-01

    Moderate somatic stress inhibits gastric acid secretion. We have investigated the role of endogenously released NO in this phenomenon. Elevation of body temperature by 3°C or a reduction of 35 mmHg (1 mmHg = 133 Pa) in blood pressure for 10 min produced a rapid and long-lasting reduction of distension-stimulated acid secretion in the rat perfused stomach in vivo. A similar inhibitory effect on acid secretion was produced by the intracisternal (i.c.) administration of oxytocin, a peptide known to be released during stress. Intracisternal administration of the NO-synthase inhibitor, NG-nitro-l-arginine methyl ester (l-NAME) reversed the antisecretory effect induced by all these stimuli, an action prevented by intracisternal coadministration of the NO precursor, l-arginine. Furthermore, microinjection of l-NAME into the dorsal motor nucleus of the vagus nerve reversed the acid inhibitory effects of mild hyperthermia, i.v. endotoxin, or i.c. oxytocin, an action prevented by prior microinjection of l-arginine. By contrast, microinjection of l-NAME into the nucleus tractus solitarius failed to affect the inhibitory effects of hyperthermia, i.v. endotoxin, or i.c. oxytocin. Immunohistochemical techniques demonstrated that following hyperthermia there was a significant increase in immunoreactivity to neuronal NO synthase in different areas of the brain, including the dorsal motor nucleus of the vagus. Thus, our results suggest that the inhibition of gastric acid secretion, a defense mechanism during stress, is mediated by a nervous reflex involving a neuronal pathway that includes NO synthesis in the brain, specifically in the dorsal motor nucleus of the vagus. PMID:8962142

  12. The Effect of Cochinchina momordica Seed Extract on Gastric Acid Secretion and Morphologic Change in Aged Rat Stomach

    PubMed Central

    Jo, Hyun Jin; Nam, Ryoung Hee; Chang, Hyun; Kim, Joo-Hyon; Park, Ji Hyun; Kang, Jung Mook; Lee, Dong Ho; Jung, Hyun Chae

    2013-01-01

    Background/Aims Cochinchina momordica seed extract (SK-MS10) has a gastric protective effect. We aimed to assess the effect of SK-MS10 on gastric acid secretion with morphologic changes in the aged rat. Methods Acid secretions were evaluated in the male F344 rats of four different ages (6-, 31-, 74-week, and 2-year). The 31-week-old rats were divided to three groups and continuously administered chow containing vehicle, SK-MS10 and lansoprazole, respectively. At the age of 74 weeks and 2 years, basal and stimulated acid was measured and the expression of mRNA and protein of H+-K+-ATPase were determined. The area of connective tissue of lamina propria was measured. Results Basal and stimulated gastric acid significantly decreased and connective tissue of lamina propria increased with age. The expression of mRNA and protein of H+-K+-ATPase significantly decreased with age. However, 74-week-old rats in the SK-MS10 group had higher stimulated gastric acid secretion than those in the vehicle and lansoprazole groups. In 2-year-old rats of SK-MS10 group, there was no increase of connective tissue. Conclusions As SK-MS10 kept the capacity of acid secretion as well as connective tissue area to comparable to young rats, it might valuable to perform further research regarding mechanism of SK-MS10 as an antiaging agent in the stomach. PMID:24073314

  13. Complete inhibition of food-stimulated gastric acid secretion by combined application of pirenzepine and ranitidine.

    PubMed

    Londong, W; Londong, V; Ruthe, C; Weizert, P

    1981-07-01

    In a double-blind, placebo controlled and randomised secretory study the effectiveness of pirenzepine, ranitidine, and their combination was compared intraindividually in eight healthy subjects receiving intravenous bolus injections. Pirenzepine (0.15 mg/kg) plus ranitidine (0.6 mg/kg) suppressed peptone-stimulated gastric acid secretion from 69 +/- 11 to 2 +/- 0.4 mmol H+/3 h; the mean percentage inhibition was 97%. Postprandial gastrin was unaffected. There were only minor side-effects in a few experiments (reduction of salivation, brief blurring of vision), but no prolactin stimulation after ranitidine or ranitidine plus pirenzepine. The combined application of ranitidine and pirenzepine inhibited meal-stimulated acid secretion more effectively and produced fewer side-effects than the combination of cimetidine plus pirenzepine studied previously. PMID:6114900

  14. Intracellular calcium-release and protein kinase C-activation stimulate sonic hedgehog gene expression during gastric acid secretion

    PubMed Central

    El-Zaatari, Mohamad; Zavros, Yana; Tessier, Art; Waghray, Meghna; Lentz, Steve; Gumucio, Deborah; Todisco, Andrea; Merchant, Juanita L.

    2010-01-01

    Introduction Hypochlorhydria during Helicobacter pylori infection inhibits gastric Shh expression. We investigated whether acid-secretory mechanisms regulate Shh gene expression through Ca2+i-dependent protein kinase C (PKC) or cAMP-dependent protein kinase A (PKA)-activation. Method We blocked Hedgehog signaling by transgenically overexpressing a secreted form of the Hedgehog interacting protein-1 (sHip-1), a natural inhibitor of hedgehog ligands, which induced hypochlorhydria. Gadolinium, EGTA+BAPTA, PKC-overexpressing adenoviruses, and PKC-inhibitors were used to modulate Ca2+i-release, PKC-activity and Shh gene expression in primary gastric cell, organ, and AGS cell line cultures. PKA hyperactivity was induced in the H+/K+-β-cholera-toxin overexpressing mice (Ctox). Results Mice that expressed sHip-1 had lower levels of gastric acid (hypochlorhydria), reduced production of somatostatin, and increased gastrin gene expression. Hypochlorhydria in these mice repressed Shh gene expression, similar to the levels obtained with omeprazole treatment of wild-type mice. However, Shh expression was also repressed in the hyperchlorhydric Ctox model with elevated cAMP, suggesting that the regulation of Shh was not solely acid-dependent, but pertained to specific acid-stimulatory signaling pathways. Based on previous reports that Ca2+i-release also stimulates acid secretion in parietal cells, we showed that gadolinium-, thapsigargin- and carbachol-mediated release of Ca2+i induced Shh expression. Ca2+-chelation with BAPTA+EGTA reduced Shh expression. Overexpression of PKC-α, -β and -δ (but not PKC-ε) induced Shh gene expression. In addition, phorbol esters induced a Shh-regulated reporter gene. Conclusion Secretagogues that stimulate gastric acid secretion induce Shh gene expression through increased Ca2+i-release and PKC activation. Shh might be the ligand transducing changes in gastric acidity to the regulation of G-cell secretion of gastrin. PMID:20816837

  15. Anti-Warburg effect of rosmarinic acid via miR-155 in gastric cancer cells

    PubMed Central

    Han, Shuai; Yang, Shaohua; Cai, Zhai; Pan, Dongyue; Li, Zhou; Huang, Zonghai; Zhang, Pusheng; Zhu, Huijuan; Lei, Lijun; Wang, Weiwei

    2015-01-01

    Background The Warburg effect refers to glycolytic production of adenosine triphosphate under aerobic conditions, and is a universal property of most cancer cells. Chronic inflammation is a key factor promoting the Warburg effect. This study aimed to determine whether rosmarinic acid (RA) has an anti-Warburg effect in gastric carcinoma in vitro and in vivo. The mechanism for the anti-Warburg effect was also investigated. Methods An MTT assay was used to examine MKN45 cell growth in vitro. An enzyme-linked immunosorbent assay was used to detect proinflammatory cytokines. Real-time polymerase chain reaction was used to evaluate levels of microRNA expression in cells. Protein expression was determined by Western blotting assay. Mouse xenograft models were established using MKN45 cells to assess the anti-Warburg effect in gastric carcinoma in vivo. Results RA suppressed glucose uptake and lactate production. It also inhibited expression of transcription factor hypoxia-inducible factor-1α, which affects the glycolytic pathway. Inflammation promoted the Warburg effect in cancer cells. As expected, RA inhibited proinflammatory cytokines and microRNAs related to inflammation, suggesting that RA may suppress the Warburg effect via an inflammatory pathway, such as that involving interleukin (IL)-6/signal transducer and activator of transcription-3 (STAT3). miR-155 was found to be an important mediator in the relationship between inflammation and tumorigenesis. We further showed that miR-155 was the target gene regulating the Warburg effect via inactivation of the IL-6/STAT3 pathway. Moreover, we found that RA suppressed the Warburg effect in vivo. Conclusion RA might potentially be a therapeutic agent for suppressing the Warburg effect in gastric carcinoma. PMID:26056431

  16. Colonization of an acid resistant Kingella denitrificans in the stomach may contribute to gastric dysbiosis by Helicobacter pylori.

    PubMed

    Okamoto, Takeshi; Hayashi, Yasuhiro; Mizuno, Hidekazu; Yanai, Hideo; Nishikawa, Jun; Nakazawa, Teruko; Iizasa, Hisashi; Jinushi, Masahisa; Sakaida, Isao; Yoshiyama, Hironori

    2014-03-01

    In the stomach of a gastric ulcer patient who had been administered an anti-acid, a gram-negative and urease-negative bacillus similar in size to Helicobacter pylori was infected together with H. pylori. According to biochemical test and 16S rRNA gene analysis, the urease-negative bacterium was identified as Kingella denitrificans, a human nasopharyngeal commensal. In contrast to the standard strain of K. denitrificans, the isolate showed catalase activity, did not produce acid from glucose, and exhibited acid tolerance. Acid tolerance of H. pylori was increased by cocultivation with the K. denitrificans isolate, but not with other isolates of K. denitrificans. Disruption of physiological and immunological niche by dysbiotic colonization of bacterium may provide pathological attributes to human stomach. Collectively, a careful administration of anti-acids to the elderly, especially those with atrophic gastritis, is necessary to avoid repression of the gastric barrier to bacteria. PMID:24462438

  17. Quantitative ultrastructural analysis of the human parietal cell during acid inhibition and increase of gastric potential difference by glucagon.

    PubMed Central

    Ivey, K J; Tarnawski, A; Sherman, D; Krause, W J; Ackman, K; Burks, M; Hewett, J

    1980-01-01

    Glucagon inhibits gastric acid secretion and increases the negativity of gastric mucosal potential difference (PD) in man. To test the hypothesis that the increased negativity of PD after glucagon in man could be due to decreased parietal cell canalicular membrane area, a quantitative ultrastructural analysis was carried out. Four healthy volunteers with normal gastric mucosa were submitted to biopsy before and 20 minutes after intravenous injection of 2 mg glucagon (G). This time corresponded with the maximal change in PD and a decrease in gastric acid secretion. Canalicular and tubulovesicular membrane area of 80 parietal cells (40 cells before glucagon and 40 cells after glucagon) were quantified by the Loud morphometric method. After glucagon, the oxyntic cell canalicular membrane area was reduced by one-fourth (P less than 0.05), while tubulovesicular membrane area showed an increase (P less than 0.05) at the same time. The decrease in the area of parietal cell canalicular membrane caused by glucagon may in part be responsible for increased negativity of the gastric PD caused by this hormone. Images Fig. 2 PMID:7364316

  18. Pharmacological modulation of gastric emptying rate of solids as measured by the carbon labelled octanoic acid breath test: influence of erythromycin and propantheline.

    PubMed Central

    Maes, B D; Hiele, M I; Geypens, B J; Rutgeerts, P J; Ghoos, Y F; Vantrappen, G

    1994-01-01

    The *C (13C or 14C) labelled octanoic acid breath test was recently developed to measure the gastric emptying rate of solids. This study aimed to investigate whether it is sensitive enough to detect pharmacologically induced changes in the gastric emptying rate. Nine healthy volunteers were studied in basal condition, after intravenous administration of 200 mg erythromycin, and after peroral administration of 30 mg propantheline. Erythromycin significantly enhanced gastric emptying in all subjects, with an increase of the gastric emptying coefficient (p = 0.0043) in eight of nine and a fall in both the gastric half emptying time (p = 0.0020) and the lag phase (p = 0.0044) in all nine. Propantheline significantly reduced the gastric emptying rate, with a decreased gastric emptying coefficient (p = 0.0007) and an increased gastric half emptying time (p = 0.0168) in all subjects, but no change in the lag phase (p = 0.1214). Further mathematical analysis showed that breath sampling at 15 minutes intervals over a four hour period is recommended to guarantee accuracy and the discriminative value of the breath test in various gastric emptying patterns. In conclusion the *C labelled octanoic acid breath test is sufficiently sensitive to show pharmacologically induced changes of gastric emptying rates of solids. PMID:8150342

  19. Protective Effect of Cod (Gadus macrocephalus) Skin Collagen Peptides on Acetic Acid-Induced Gastric Ulcer in Rats.

    PubMed

    Niu, Huina; Wang, Zhicong; Hou, Hu; Zhang, Zhaohui; Li, Bafang

    2016-07-01

    This research was performed to explore the protective effect of cod skin collagen peptides (CCP) on gastric ulcer induced by acetic acid. The CCP were fractionated into low molecular CCP (LMCCP, Mw < 3 kDa) and high molecular CCP (HMCCP, Mw > 3 kDa). In HMCCP and LMCCP, glycine of accounted for about one-third of the total amino acids without cysteine and tryptophan, and hydrophobic amino acids accounted for about 50%. After 21 d CCP treatment (60 or 300 mg/kg, p.o./daily), the healing effects on acetic acid-induced gastric ulcers were evaluated by macroscopic measure, microscopic measure, and immune histochemistry. Moreover, the expression levels of the growth factors, such as vascular endothelial growth factor, epidermal growth factor, transforming growth factor β1 (TGFβ1), and the heat shock protein 70 (HSP70) was detected. The results showed that both LMCCP and HMCCP could significantly decrease the ulcer areas and promote the healing of the lesions. They also could improve the levels of hexosamine, glutathione, superoxide dismutase, and glutathione peroxidase, and reduce the content of malondialdehyde and inducible nitric oxide synthase. In addition, the expression level of TGFβ1 gene and HSP70 mRNA was significantly improved by the treatment. It suggested that CCP could be able to improve symptoms of gastric ulcer and probably be used in the treatment of gastric ulcer. PMID:27219644

  20. Overexpression of fatty acid synthase predicts a poor prognosis for human gastric cancer

    PubMed Central

    DUAN, JIANGMAN; SUN, LI; HUANG, HONGXIANG; WU, ZHENZHEN; WANG, LIN; LIAO, WANGJUN

    2016-01-01

    Fatty acid synthase (FASN), a lipogenic multi-enzyme complex, is reported to be overexpressed in various types of of tumor tissues and serves an important role in tumor development and progression. However, the expression of FASN and its possible role in gastric cancer (GC) remains to be defined. In the present study, FASN expression in a group sample of 167 GC tissues was detected by immunohistochemistry and its correlation with clinicopathological features was analyzed. By clinical analysis, it was identified that FASN overexpression was positively correlated with the overall survival [P=0.008; hazard ratio (HR), 4.412; 95% confidence interval (CI), 1.463–13.305] and recurrence rate (P=0.014; HR, 1.705; 95% CI, 1.116–2.606) in patients with GC. In addition, expression of the FASN protein in GC tissues was correlated with age (P=0.032), clinical stage (P<0.001), gastric wall invasion (P=0.014), lymph node metastasis (P<0.001) and distant metastasis (P<0.001), however not with gender (P>0.05). In addition, FASN was observed to be overexpressed in GC tissues at an mRNA and protein level, compared with the adjacent non-cancerous tissues (P<0.05). Taken together, it was suggested that FASN was closely associated with GC metastasis and survival, which further provided evidence that FASN may be a promising prognostic biomarker for patients with GC. PMID:26936091

  1. Okadaic Acid Toxin at Sublethal Dose Produced Cell Proliferation in Gastric and Colon Epithelial Cell Lines

    PubMed Central

    del Campo, Miguel; Toledo, Héctor; Lagos, Néstor

    2013-01-01

    The aim of this study was to analyze the effect of Okadaic Acid (OA) on the proliferation of gastric and colon epithelial cells, the main target tissues of the toxin. We hypothesized that OA, at sublethal doses, activates multiple signaling pathways, such as Erk and Akt, through the inhibition of PP2A. To demonstrate this, we carried out curves of doses and time response against OA in AGS, MKN-45 and Caco 2 cell lines, and found an increase in the cell proliferation at sublethal doses, at 24 h or 48 h exposure. Indeed, cells can withstand high concentrations of the toxin at 4 h exposure, the time chosen considering the maximum time before total gastric emptying. We have proved that this increased proliferation is due to an overexpression of Cyclin B, a cyclin that promotes the passage from G2 to mitosis. In addition, we have demonstrated that OA induces activation of Akt and Erk in the three cells lines, showing that OA can activate pathways involved in oncogenesis. In conclusion, this study contributes to the knowledge about the possible effects of chronic OA consumption. PMID:24317467

  2. Mycophenolic Acid Inhibits Migration and Invasion of Gastric Cancer Cells via Multiple Molecular Pathways

    PubMed Central

    Dun, Boying; Sharma, Ashok; Teng, Yong; Liu, Haitao; Purohit, Sharad; Xu, Heng; Zeng, Lingwen; She, Jin-Xiong

    2013-01-01

    Mycophenolic acid (MPA) is the metabolized product and active element of mycophenolate mofetil (MMF) that has been widely used for the prevention of acute graft rejection. MPA potently inhibits inosine monophosphate dehydrogenase (IMPDH) that is up-regulated in many tumors and MPA is known to inhibit cancer cell proliferation as well as fibroblast and endothelial cell migration. In this study, we demonstrated for the first time MPA’s antimigratory and anti-invasion abilities of MPA-sensitive AGS (gastric cancer) cells. Genome-wide expression analyses using Illumina whole genome microarrays identified 50 genes with ≥2 fold changes and 15 genes with > 4 fold alterations and multiple molecular pathways implicated in cell migration. Real-time RT-PCR analyses of selected genes also confirmed the expression differences. Furthermore, targeted proteomic analyses identified several proteins altered by MPA treatment. Our results indicate that MPA modulates gastric cancer cell migration through down-regulation of a large number of genes (PRKCA, DOCK1, INF2, HSPA5, LRP8 and PDGFRA) and proteins (PRKCA, AKT, SRC, CD147 and MMP1) with promigratory functions as well as up-regulation of a number of genes with antimigratory functions (ATF3, SMAD3, CITED2 and CEAMCAM1). However, a few genes that may promote migration (CYR61 and NOS3) were up-regulated. Therefore, MPA’s overall antimigratory role on cancer cells reflects a balance between promigratory and antimigratory signals influenced by MPA treatment. PMID:24260584

  3. Ursolic Acid Inhibits the Proliferation of Gastric Cancer Cells by Targeting miR-133a.

    PubMed

    Xiang, Fenfen; Pan, Chunying; Kong, Qianqian; Wu, Rong; Jiang, Jiemin; Zhan, Yueping; Xu, Jian; Gu, Xingang; Kang, Xiangdong

    2014-01-01

    Ursolic acid (UA), a potential chemotherapeutic agent, has the properties of inhibition of the growth of many human cancer cell lines. Whether UA can inhibit the growth and metastasis of human gastric cancer cells remains unknown. In this study, it was found that UA inhibited the growth and metastasis of human gastric cancer cells in vitro. Our results showed the increase of the percent of apoptotic cells and G1 phase, the inhibition of cell migrations well as the decrease of the expression of Bax, caspase 3 and Bcl-2 in BGC-823 cells after the treatment with UA. Real-time quantitative PCR analysis showed that UA treatment upregulated the level of miR-133a in BGC-823 cells. Overexpression of miR-133a increased the G1 phase of cell cycle and decreased Akt1 expression in BGC-823 cells. These outcomes might be secondary to the increased expression of miR-133a after the treatment with UA. PMID:26629938

  4. Gastric acid induces mucosal H2S release in rats by upregulating mRNA and protein expression of cystathionine gamma lyase.

    PubMed

    Mard, Seyyed Ali; Veisi, Ali; Ahangarpour, Akram; Gharib-Naseri, Mohammad Kazem

    2015-11-01

    It is well known that hydrogen sulfide (H2S) protects the gastric mucosa against gastric acid and other noxious stimulants by several mechanisms but until now the effect of gastric acid on H2S production has not been evaluated. This study was performed to determine the effect of basal and stimulated gastric acid secretion on mRNA and protein expression of cystathionine gamma lyase (CSE) and cystathionine beta synthase (CBS), and on mucosal release of H2S in rats. Seventy-two male rats were randomly assigned into 9 groups (8 in each)-control, distention, and pentagastrin-induced gastric acid secretion groups. The effects of 15% alcohol solution, propargylglycine (PAG), L-NAME, and pantoprazole were also investigated. Under anesthesia, animals underwent tracheostomy and midline laparotomy. A catheter was inserted into the stomach through the duodenum for gastric washout. At the end of the experiments, the animals were killed and the gastric mucosa was collected to measure H2S concentration and to quantify mRNA expression of CSE and CBS by quantitative real-time PCR, and expression of their proteins by western blot. Basal and stimulated gastric acid secretion increased mucosal levels of H2S, and mRNA and protein expression of CSE. Pantoprazole and L-NAME reversed H2S release and restored protein expression of CSE to the control level. Pantoprazole, but not propargylglycine, pretreatment inhibited the elevated level of protein expression of eNOS in response to distention-induced gastric acid secretion. Our findings indicated that NO mediated the stimulatory effect of gastric acid on H2S release and protein expression of CSE. PMID:26319795

  5. PMK-S005 Alleviates Age-Related Gastric Acid Secretion, Inflammation, and Oxidative Status in the Rat Stomach

    PubMed Central

    Choi, Yoon Jeong; Kim, Nayoung; Lee, Ju Yup; Nam, Ryoung Hee; Suh, Ji Hyung; Lee, Sun Min; Ham, Min Hee; Jo, Hyun Jin; Shim, Young Kwang; Park, Yo Han; Lee, Jong-Chan; Choi, Yoon Jin; Lee, Hye Seung; Lee, Dong Ho

    2016-01-01

    Background/Aims The aim of this study was to evaluate the effect of the synthetic S-allyl-l-cysteine (SAC) PMK-S005 on gastric acid secretion, inflammation, and antioxidant enzymes in aging rats. Methods The rats were divided into four groups at 31 weeks of age and were continuously fed a diet containing a vehicle control, PMK-S005 (5 or 10 mg/kg), or lansoprazole (5 mg/kg). Gastric acid secretion and connective tissue thickness of the lamina propria were evaluated at 74 weeks and 2 years of age. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and COX-2 levels were measured by using enzyme-linked immunosorbent assays (ELISAs) or Western blot assays. Levels of antioxidant enzymes, including heme oxyganase 1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), were also measured. Results As the rats aged, gastric acid secretion significantly decreased, and the connective tissue of the lamina propria increased. However, 74-week-old rats in the PMK-S005 group exhibited greater levels of gastric acid secretion than those of the control and lansoprazole groups. The increase of TNF-α, IL-1β, and COX-2 expression in 74-week and 2-year-old control rats were inhibited by PMK-S005. In addition, the decrease in HO-1 and NQO-1 protein expression that occurred with aging was inhibited by PMK-S005 in the 74-week-old rats. Conclusions These results suggest that PMK-S005 has therapeutic potential as an antiaging agent to ameliorate age-related gastric acid secretion, inflammation, and oxidative stress in the stomach. PMID:27172930

  6. Control of gastric acid secretion. Histamine H2-receptor antagonists and H+K(+)-ATPase inhibitors.

    PubMed

    Shamburek, R D; Schubert, M L

    1992-09-01

    Gastric acid secretion is regulated by an intricate interplay of neural (acetylcholine), hormonal (gastrin), and paracrine (histamine, somatostatin) mechanisms. Receptors for each of these agents and the signal transduction pathways to which these receptors are coupled have been identified on the parietal cell. The stimulatory effect of acetylcholine and gastrin is mediated by an increase in cytosolic calcium, whereas that of histamine is mediated by activation of adenylate cyclase and generation of cAMP. Strong potentiation between histamine and either gastrin or acetylcholine reflects postreceptor interaction between the distinct pathways as well as the ability of acetylcholine and gastrin to release histamine from mucosal ECL cells. The inhibitory effects of somatostatin on acid secretion are mediated by receptors coupled by guanine nucleotide-binding proteins to inhibition of adenylate cyclase activity. All the pathways converge on and modulate the activity of the luminal enzyme, H+K(+)-ATPase, the proton pump of the parietal cell. Precise information on the mechanisms involved in gastric acid secretion has led to the development of potent drugs capable of inhibiting acid secretion. These include competitive antagonists that interact with stimulatory receptors (e.g., histamine H2-receptor antagonists) as well as noncompetitive inhibitors of H+K(+)-ATPase (e.g., omeprazole). The histamine H2-receptor antagonists (cimetidine, ranitidine, famotidine, and nizatidine) continue as first-line therapy for peptic ulcer disease and are effective in preventing relapse. Although they are generally well tolerated, histamine H2-receptor antagonists may cause untoward CNS, cardiac, and endocrine effects as well as interference with the absorption, metabolism, and elimination of various drugs. Omeprazole is a weak base that reaches the parietal cell through the bloodstream, diffuses through the cytoplasm, and becomes activated and trapped as a sulfenamide in the acidic

  7. Relationship between gastric acid secretion and the rate of recurrent ulcer after parietal cell vagotomy.

    PubMed Central

    Cohen, F; Valleur, P; Serra, J; Brisset, D; Chiche, L; Hautefeuille, P

    1993-01-01

    OBJECTIVE: This study assessed the effect of gastric secretion on the rate of recurrent ulcer after parietal cell vagotomy for duodenal ulcer. SUMMARY BACKGROUND DATA: Three hundred patients who underwent parietal cell vagotomy for duodenal ulcer between 1975 and 1986 were evaluated. The mean follow-up period for 280 patients was 5 years. METHODS: The gastric secretion tests concerned basal acid output (BAO) and peak acid output stimulated by pentagastrin or insulin. Tests were preoperative for 172 patients and postoperative for 118. RESULTS: At the end of that time, the overall incidence of symptomatic recurrent ulcer was 15%. Two criteria were shown to be important predictors of recurrent ulcer: preoperative BAO > 7 mmol/hr, for which the recurrence rate 5 years after vagotomy was 30% versus 11% for values below this threshold (p = 0.01), and postoperative BAO > 1.4 mmol/hr, for which the recurrence rate at 5 years was 72% versus 8% for lower values (p = 0.0001). All patients with recurrent ulcer had either a postoperative BAO > 7 mmol/hr and/or a postoperative reduction in BAO < 80%. CONCLUSION: Preoperative BAO > 7 mmol/hr and postoperative BAO > 1.4 mmol/hr were shown to be factors predictive of RU. All patients with RU presented either with preoperative BAO > 7 mmol/hr and/or a reduction in BAO < 80%. Consequently, in our opinion, these criteria could be used either to select patients for vagotomy or to assess the effectiveness of vagotomy of different types, especially those performed by celioscopy. PMID:8452404

  8. Protein kinase C-α attenuates cholinergically stimulated gastric acid secretion of rabbit parietal cells

    PubMed Central

    Fährmann, Michael; Kaufhold, Marc; Pfeiffer, Andreas F; Seidler, Ursula

    2003-01-01

    The phorbolester 12-O-tetradecanoyl phorbol-13-acetate (TPA), an activator of protein kinase C (PKC), inhibits cholinergic stimulation of gastric acid secretion. We observed that this effect strongly correlated with the inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity in rabbit parietal cells. The aim of this study was to specify the function of PKC-α in cholinergically stimulated H+ secretion. PKC-α represents the only calcium-dependent PKC isoenzyme that has been detected in rabbit parietal cells. Gö 6976, an inhibitor of calcium-dependent PKC, concentration-dependently antagonized the inhibitory effect of TPA, and, therefore, revealed the action of PKC-α on carbachol-induced acid secretion in rabbit parietal cells. TPA exerted no additive inhibition of carbachol-stimulated acid secretion if acid secretion was partially inhibited by the potent CaMKII inhibitor 1-[N,O-bis(5-isoquinolinsulfonyl)-N-methyl-L-tyrosyl]-4-phenyl-piperazine (KN-62). Since both kinase modulators, TPA and KN-62, affected no divergent signal transduction pathways in the parietal cell, an in vitro model has been used to study if PKC directly targets CaMKII. CaMKII purified from parietal cell-containing gastric mucosa of pig, was transphosphorylated by purified cPKC containing PKC-α up to 1.8 mol Pi per mol CaMKII in vitro. The autonomy site of CaMKII was not transphosphorylated by PKC. The phosphotransferase activity of the purified CaMKII was in vitro inhibited after transphosphorylation by PKC if calmodulin was absent during transphosphorylation. Attenuation of CaMKII activity by PKC showed strong similarity to the downregulation of CaMKII by basal autophosphorylation. Our results suggest that PKC-α and CaMKII are closely functionally linked in a cholinergically induced signalling pathway in rabbit parietal cells. We assume that in cholinergically stimulated parietal cells PKC-α transinhibits CaMKII activity, resulting in an attenuation of acid secretion

  9. AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells.

    PubMed

    Jing, Yue; Wang, Gang; Ge, Ying; Xu, Minjie; Tang, Shuainan; Gong, Zhunan

    2016-01-01

    Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy. PMID:27073325

  10. AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells

    PubMed Central

    Jing, Yue; Wang, Gang; Ge, Ying; Xu, Minjie; Tang, Shuainan; Gong, Zhunan

    2016-01-01

    Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G0/G1 phase and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy. PMID:27073325

  11. Protective effect of anacardic acids from cashew (Anacardium occidentale) on ethanol-induced gastric damage in mice.

    PubMed

    Morais, Talita C; Pinto, Natália B; Carvalho, Karine Maria M B; Rios, Jeison B; Ricardo, Nagila Maria P S; Trevisan, Maria Teresa S; Rao, Vietla S; Santos, Flávia A

    2010-01-01

    Cashew nut-shell liquid and the contained anacardic acids (AAs) have been shown to possess antioxidant, lipoxygenase inhibitory, anti-Helicobacter pylori and antitumor properties. Despite these known effects, hitherto there were no published reports on their likely gastroprotective effects. The present study was designed to verify whether AAs afford gastroprotection against the ethanol-induced gastric damage and to examine the underlying mechanism(s). Gastric damage was induced by intragastric administration of 0.2mL of ethanol (96%). Mice in groups were pretreated orally with AAs (10, 30 and 100mg/kg), misoprostol (50 microg/kg), or vehicle (2% Tween 80 in saline, 10mL/kg), 45min before ethanol administration. They were sacrificed 30min later, the stomachs excised, and the mucosal lesion area (mm(2)) measured by planimetry. Gastroprotection was assessed in relation to inhibition of gastric lesion area. To study the gastroprotective mechanism(s), its relations to capsaicin-sensitive fibers, endogenous prostaglandins, nitric oxide and ATP-sensitive potassium channels were analysed. Treatments effects on ethanol-associated oxidative stress markers GSH, MDA, catalase, SOD, and total nitrate/nitrite levels as an index of NO were measured in gastric tissue. Besides, the effects of AAs on gastric secretory volume and total acidity were analysed in 4-h pylorus-ligated rat. AAs afforded a dose-related gastroprotection against the ethanol damage and further prevented the ethanol-induced changes in the levels of GSH, MDA, catalase, SOD and nitrate/nitrite. However, they failed to modify the gastric secretion or the total acidity. It was observed that the gastroprotection by AAs was greatly reduced in animals pretreated with capsazepine, indomethacin, l-NAME or glibenclamide. These results suggest that AAs afford gastroprotection principally through an antioxidant mechanism. Other complementary mechanisms include the activation of capsaicin-sensitive gastric afferents

  12. The G-protein-coupled bile acid receptor Gpbar1 (TGR5) suppresses gastric cancer cell proliferation and migration through antagonizing STAT3 signaling pathway

    PubMed Central

    Guo, Cong; Su, Jia; Li, Zhijun; Xiao, Rui; Wen, Jianxun; Li, Yanyan; Zhang, Meng; Zhang, Xueting; Yu, Donna; Huang, Wendong

    2015-01-01

    Gpbar1 (TGR5), a membrane-bound bile acid receptor, is well known for its roles in regulation of energy homeostasis and glucose metabolism. Here we show that TGR5 is a suppressor of gastric cancer cell proliferation and migration through antagonizing STAT3 signaling pathway. We firstly show that TGR5 activation greatly inhibited proliferation and migration of human gastric cancer cells and strongly induced gastric cancer cell apoptosis. We then found that TGR5 activation antagonized STAT3 signaling pathway through suppressing the phosphorylation of STAT3 and its transcription activity induced by lipopolysaccharide (LPS) or interleukin-6. TGR5 overexpression with ligand treatment inhibited gene expression mediated by STAT3. It suggests that TGR5 antagonizes gastric cancer proliferation and migration at least in part by inhibiting STAT3 signaling. These findings identify TGR5 as a suppressor of gastric cancer cell proliferation and migration that may serve as an attractive therapeutic tool for human gastric cancer. PMID:26417930

  13. Carbonic Anhydrase Inhibitors. Part 91. Metal Complexes of Heterocyclic Sulfonamides as Potential Pharmacological Agents in the Treatment of Gastric Acid Secretion Imbalances

    PubMed Central

    Ilies, Marc A.; Scozzafava, Andrea

    2000-01-01

    Zinc, magnesium, aluminum and copper complexes of several potent, clinically used carbonic anhydrase (CA) sulfonamide inhibitors, such as acetazolamide, methazolamide, ethoxzolamide and benzolamide were tested for their possible applications as antacids, in experimental animals. Gastric acid secretion parameters 3 days after treatment with these CA inhibitors (2 × 500 mg, twice a day), in dogs with chronic gastric fistulas, led to the observation that the gastric acid parameters BAO (the basal acid output), and MAO (the maximal acid output after stimulation with histamine) were drastically reduced, as compared to the same parameters in animals that did not receive these enzyme inhibitors. These are promising results for the possible use of metal complexes of heterocyclic sulfonamides as treatment alternatives (alone or in combination with other drugs) for gastric acid secretion imbalances. PMID:18475926

  14. Relation between acid back-diffusion and luminal surface hydrophobicity in canine gastric mucosa: Effects of salicylate and prostaglandin

    SciTech Connect

    Goddard, P.J.

    1989-01-01

    The stomach is thought to be protected from luminal acid by a gastric mucosal barrier that restricts the diffusion of acid into tissue. This study tested the hypothesis that the hydrophobic luminal surface of canine gastric mucosa incubated in Ussing chambers, impedes the back-diffusion of luminal acid into the tissue. Isolated sheets of mucosa were treated with cimetidine to inhibit spontaneous acid secretion, and incubated under conditions that prevented significant secretion of luminal bicarbonate. By measuring acid loss from the luminal compartment using the pH-stat technique, acid back-diffusion was continuously monitored; potential difference (PD) was measured as an index of tissue viability. Tissue luminal surface hydrophobicity was estimated by contact angle analysis at the end of each experiment. Addition of 16,16-dimethyl prostaglandin E{sub 2} to the nutrient compartment enhanced luminal surface hydrophobicity, but did not reduce acid back-diffusion in tissues that maintained a constant PD. 10 mM salicylate at pH 4.00 in the luminal compartment reduced surface hydrophobicity, but this decrease did not occur if 1 ug/ml prostaglandin was present in the nutrient solution. Despite possessing relatively hydrophilic and relatively hydrophobic surface properties, respectively, acid back-diffusion in the absence of salicylate was not significantly different between these two groups. Neither group maintained a PD after incubation with salicylate. Lastly, radiolabeled salicylate was used to calculate the free (non-salicylate associated) acid loss in tissues incubated with salicylate and/or prostaglandin. No significant correlation was found between free acid back-diffusion and luminal surface hydrophobicity. These data do not support the hypothesis that acid back-diffusion in impeded by the hydrophobic surface presented by isolated canine gastric mucosa.

  15. Endogenous neuropeptide-Y depresses the afferent signalling of gastric acid challenge to the mouse brainstem via Y2 and Y4 receptors

    PubMed Central

    Wultsch, T.; Painsipp, E.; Thoeringer, C.K.; Herzog, H.; Sperk, G.; Holzer, P.

    2015-01-01

    Vagal afferents signal gastric acid challenge to the nucleus tractus solitarii (NTS) of the rat brainstem. This study investigated whether NTS neurons in the mouse also respond to gastric acid challenge and whether this chemonociceptive input is modified by neuropeptide-Y (NPY) acting via Y2 or Y4 receptors. The gastric mucosa of female mice was exposed to different concentrations of HCl or saline, excitation of neurons in the NTS visualized by c-Fos immunohistochemistry, gastric emptying deduced from the gastric volume recovery, and gastric lesion formation evaluated by planimetry. Relative to saline, intragastric HCl (0.15-0.35 M) increased the number of c-Fos-expressing cells in the NTS in a concentration-dependent manner, inhibited gastric emptying but failed to cause significant haemorrhagic injury in the stomach. Mice in which the NPY Y2 or Y4 receptor gene had been deleted responded to gastric acid challenge with a significantly higher expression of c-Fos in the NTS, the increases amounting to 39 and 31 %, respectively. The HCl-induced inhibition of gastric emptying was not altered by deletion of the Y2 or Y4 receptor gene. BIIE0246 (0.03 mmol/kg subcutaneously), a Y2 receptor antagonist which does not cross the blood-brain barrier, did not modify the c-Fos response to gastric acid challenge. The Y2 receptor agonist peptide YY-(3-36) (0.1 mg/kg intraperitoneally) likewise failed to alter the gastric HCl-evoked expression of c-Fos in the NTS. BIIE0246, however, prevented the effect of peptide YY-(3-36) to inhibit gastric acid secretion as deduced from measurement of intragastric pH. The current data indicate that gastric challenge with acid concentrations that do not induce overt injury but inhibit gastric emptying is signalled to the mouse NTS. Endogenous NPY acting via Y2 and Y4 receptors depresses the afferent input to the NTS by a presumably central site of action. PMID:16216428

  16. A Chronological Increase in Gastric Acid Secretion from 1995 to 2014 in Young Japanese Healthy Volunteers under the Age of 40 Years Old.

    PubMed

    Iijima, Katsunori; Koike, Tomoyuki; Abe, Yasuhiko; Ohara, Shuichi; Shimosegawa, Tooru

    2016-01-01

    Gastric acid secretion levels are an important determinant of the manifestation of acid-related upper GI diseases such as gastroesophageal reflux disease. We recently reported that gastric acid secretion levels did not change from the 1990s to 2010s in H. pylori-negative asymptomatic Japanese outpatients with a mean age of 63 years old. However, because young people have a quite different lifestyle, including dietary pattern, from elderly people in Japan, it is worth investigating any chronologic changes in gastric acid secretion in younger generations. The aim of this analysis is to investigate the potential changes in gastric acid secretion from 1995 to 2014 in young Japanese healthy volunteers. Eighty-eight young Japanese healthy volunteers under the age of 40 with a mean age of 26 were extracted from a database accumulated from 1995 to 2014 for the present analysis. Their gastrin-stimulated gastric acid level was determined with the endoscopic gastrin test. In 76 H. pylori-negative subjects, gastric acid secretion levels showed a significant positive correlation with the calendar year when the test was performed (r = 0.27, p < 0.01). A similar trend was observed in 12 H. pylori-positive subjects. A chronological 5-year time period showed a significant positive association with gastric acid secretion in univariate and multivariate analyses (p < 0.01 and p = 0.01, respectively). Gastric acid secretion levels have been increasing in young Japanese healthy volunteers during the last 20 years. We need to monitor future trends in the prevalence of acid-related diseases such as gastro-esophageal reflux disease in Japan. PMID:27440759

  17. Effect of acid secretion blockade on acute gastric mucosal lesions induced by Tityus serrulatus scorpion toxin in anaesthetized rats.

    PubMed

    Melo, Júnio Rios; de Araújo, Gnana Keith Marques; da Luz, Magda Maria Profeta; da Conceição, Sérgio Alexandre; Lisboa, Felipe Assis; Moraes-Santos, Tasso; Cunha-Melo, José Renan

    2006-10-01

    Scorpion venom (TX) promotes gastric acid and pepsin secretion leading to acute gastric mucosal lesions (AGML), when injected in animals. The goal of the present study was to observe the effects of acid gastric secretion blockers over the incidence of TX-induced AGML in vivo. To verify this model, we used male albino rats, fasted 18-20 h (n=122) and anaesthetized with urethane (1.4 g/kg, i.p.). Their trachea and left femoral vein were both cannulated; the first to avoid airway obstructions during scorpion intoxication and the second for administration of saline, TX and acid blockers. Following the surgical procedure, the animals were divided in 10 groups of at least 10 animals each. Control groups were injected with NaCl 0.9% 1 ml/kg (n=10) or TX 375 microg/kg (n=32). Test groups (n=10, each) received atropine 5 mg/kg, cimetidine 10mg/kg, ranitidine 2.5mg/kg, ranitidine 5mg/kg, omeprazol 1 mg/kg, omeprazol 4 mg/kg, octreotide 80 and octreotide 100 microg/kg 10 min before the TX was injected. After 1h of intoxication, the stomach was resected for macroscopic study and the gastric secretion was collected for volume, pH and acid output assessment. We observed that all blockers were able to completely or partially prevent the TX-induced acid secretion as well as the AGML (p<0.05). Our data suggest the TX-induced AGML can be prevented by different class of acid blockers injected before the intoxication. PMID:16926041

  18. Omega-3 Polyunsaturated Fatty Acids Intake to Regulate Helicobacter pylori-Associated Gastric Diseases as Nonantimicrobial Dietary Approach

    PubMed Central

    Park, Jong-Min; Jeong, Migyeong; Kim, Eun-Hee; Han, Young-Min; Kwon, Sung Hun; Hahm, Ki-Baik

    2015-01-01

    Omega-3 polyunsaturated fatty acids (n-3 PUFAs), commonly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been acknowledged as essential long-chain fatty acids imposing either optimal health promotion or the rescuing from chronic inflammatory diseases such as atherosclerosis, fatty liver, and various inflammatory gastrointestinal diseases. Recent studies dealing with EPA and DHA have sparked highest interests because detailed molecular mechanisms had been documented with the identification of its receptor, G protein coupled receptor, and GPR120. In this review article, we have described clear evidences showing that n-3 PUFAs could reduce various Helicobacter pylori- (H. pylori-) associated gastric diseases and extended to play even cancer preventive outcomes including H. pylori-associated gastric cancer by influencing multiple targets, including proliferation, survival, angiogenesis, inflammation, and metastasis. Since our previous studies strongly concluded that nonantimicrobial dietary approach for reducing inflammation, for instance, application of phytoceuticals, probiotics, natural products including Korean red ginseng, and walnut plentiful of n-3 PUFAs, might be prerequisite step for preventing H. pylori-associated gastric cancer as well as facilitating the rejuvenation of precancerous atrophic gastritis, these beneficial lipids can restore or modify inflammation-associated lipid distortion and correction of altered lipid rafts to send right signaling to maintain healthy stomach even after chronic H. pylori infection. PMID:26339635

  19. Omega-3 Polyunsaturated Fatty Acids Intake to Regulate Helicobacter pylori-Associated Gastric Diseases as Nonantimicrobial Dietary Approach.

    PubMed

    Park, Jong-Min; Jeong, Migyeong; Kim, Eun-Hee; Han, Young-Min; Kwon, Sung Hun; Hahm, Ki-Baik

    2015-01-01

    Omega-3 polyunsaturated fatty acids (n-3 PUFAs), commonly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been acknowledged as essential long-chain fatty acids imposing either optimal health promotion or the rescuing from chronic inflammatory diseases such as atherosclerosis, fatty liver, and various inflammatory gastrointestinal diseases. Recent studies dealing with EPA and DHA have sparked highest interests because detailed molecular mechanisms had been documented with the identification of its receptor, G protein coupled receptor, and GPR120. In this review article, we have described clear evidences showing that n-3 PUFAs could reduce various Helicobacter pylori- (H. pylori-) associated gastric diseases and extended to play even cancer preventive outcomes including H. pylori-associated gastric cancer by influencing multiple targets, including proliferation, survival, angiogenesis, inflammation, and metastasis. Since our previous studies strongly concluded that nonantimicrobial dietary approach for reducing inflammation, for instance, application of phytoceuticals, probiotics, natural products including Korean red ginseng, and walnut plentiful of n-3 PUFAs, might be prerequisite step for preventing H. pylori-associated gastric cancer as well as facilitating the rejuvenation of precancerous atrophic gastritis, these beneficial lipids can restore or modify inflammation-associated lipid distortion and correction of altered lipid rafts to send right signaling to maintain healthy stomach even after chronic H. pylori infection. PMID:26339635

  20. Do sensory neurons mediate adaptive cytoprotection of gastric mucosa against bile acid injury?

    PubMed

    Mercer, D W; Ritchie, W P; Dempsey, D T

    1992-01-01

    Pretreatment with the mild irritant 1 mmol acidified taurocholate protects the gastric mucosa from the injury induced by the subsequent application of 5 mmol acidified taurocholate, a phenomenon referred to as "adaptive cytoprotection." How this occurs remains an enigma. The purpose of this study was to investigate the role of sensory neurons and mucus secretion in this phenomenon. Prior to injury with 5 mmol acidified taurocholate (pH 1.2), the stomachs of six groups of rats were subjected to the following protocol. Two groups were topically pretreated with either saline or the mild irritant 1 mmol acidified taurocholate. Two other groups received the topical anesthetic 1% lidocaine prior to pretreatment with either saline or 1 mmol acidified taurocholate. The last two groups got the mucolytic agent 10% N-acetylcysteine (NAC) after pretreatment with either saline or 1 mmol acidified taurocholate. Injury was assessed by measuring net transmucosal ion fluxes, luminal appearance of deoxyribonucleic acid (DNA), and gross and histologic injury. Pretreatment with the mild irritant 1 mmol acidified taurocholate significantly decreased bile acid-induced luminal ion fluxes and DNA accumulation, suggesting mucosal protection (corroborated by gross and histologic injury analysis). This effect was negated by lidocaine but not by NAC. Thus, it appears that sensory neurons, and not increased mucus secretion, play a critical role in adaptive cytoprotection. PMID:1733359

  1. Parenteral control of gastric acid hypersecretion in patients with Zollinger-Ellison syndrome.

    PubMed

    Vinayek, R; Hahne, W F; Euler, A R; Norton, J A; Jensen, R T

    1993-10-01

    Parenteral control of gastric acid hypersecretion in patients with Zollinger-Ellison syndrome is increasingly required; however, existing methods of determining the required dose are cumbersome and not applicable in all centers. A previous study suggested that the required parenteral dose of histamine H2-receptor antagonists correlated with the previous oral dose. In the present study, in 31 patients with Zollinger-Ellison syndrome we evaluated the hypothesis that an effective parenteral histamine H2-receptor antagonist dose could be predicted from the previous oral dose. Twenty-three patients were taking oral ranitidine (mean 1.3 g/day), six patients famotidine (152 mg/day), and two patients cimetidine (1.8 g/day). Each patient was treated with a continuous intravenous infusion of the equivalent dose of ranitidine (mean dose 1 mg/kg/hr with 35% requiring 0.5 mg/kg/hr, 49% 1 mg/kg/hr, 3% 1.5 mg/kg/hr, 10% 2 mg/kg/hr, and 3% 2.5 mg/kg/hr. This dose of ranitidine acutely controlled acid secretion (< 10 meq/hr) in all patients. To evaluate long-term efficacy and safety, 20 patients were maintained on this dose through the peri- and postoperative periods. Mean duration was 7.1 days with 25% treated 3-5 days, 40% 6-8 days, 30% 8-10 days, and 5% > 10 days. The predicted dose continued to control acid secretion in 95% of patients with one patient requiring one dose adjustment. No biochemical, clinical, or hematological toxicity was seen, although ranitidine was stopped in one patient because of skin rash. These results demonstrate that the parenteral dose of ranitidine required to control acid secretion in patients with Zollinger-Ellison syndrome can be predicted from the oral dose.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8104773

  2. Lateral hypothalamic lesions cause gastric injury by stimulating gastric contractility.

    PubMed

    Garrick, T; Grijalva, C V; Trauner, M

    1993-07-01

    Changes in gastric contractility following lateral hypothalamic (LH) lesions with and without bilateral cervical vagotomy were measured in urethan-anesthetized rats. LH lesions were induced with direct current passed through stereotaxically placed electrodes. Gastric contractility was recorded continuously for 4 h with acutely implanted strain gauge force transducers and analyzed by computer. LH lesions consistently stimulated gastric contractility and caused more gastric mucosal injury than control conditions. Vagotomy blocked both gastric mucosal injury and high-amplitude gastric contractions. In rats with LH lesions and exogenously infused intragastric hydrochloric acid, atropine methyl nitrate inhibited high-amplitude gastric contractions and gastric erosions. These findings indicate that LH lesions stimulate vagally mediated high-amplitude gastric contractions, which, in the presence of hydrochloric acid, cause gastric mucosal erosions. PMID:8338162

  3. Managing potential drug-drug interactions between gastric acid-reducing agents and antiretroviral therapy: experience from a large HIV-positive cohort.

    PubMed

    Lewis, J M; Stott, K E; Monnery, D; Seden, K; Beeching, N J; Chaponda, M; Khoo, S; Beadsworth, M B J

    2016-02-01

    Drug-drug interactions between antiretroviral therapy and other drugs are well described. Gastric acid-reducing agents are one such class. However, few data exist regarding the frequency of and indications for prescription, nor risk assessment in the setting of an HIV cohort receiving antiretroviral therapy. To assess prevalence of prescription of gastric acid-reducing agents and drug-drug interaction within a UK HIV cohort, we reviewed patient records for the whole cohort, assessing demographic data, frequency and reason for prescription of gastric acid-reducing therapy. Furthermore, we noted potential drug-drug interaction and whether risk had been documented and mitigated. Of 701 patients on antiretroviral therapy, 67 (9.6%) were prescribed gastric acid-reducing therapy. Of these, the majority (59/67 [88.1%]) were prescribed proton pump inhibitors. We identified four potential drug-drug interactions, which were appropriately managed by temporally separating the administration of gastric acid-reducing agent and antiretroviral therapy, and all four of these patients remained virally suppressed. Gastric acid-reducing therapy, in particular proton pump inhibitor therapy, appears common in patients prescribed antiretroviral therapy. Whilst there remains a paucity of published data, our findings are comparable to those in other European cohorts. Pharmacovigilance of drug-drug interactions in HIV-positive patients is vital. Education of patients and staff, and accurate data-gathering tools, will enhance patient safety. PMID:25721922

  4. Liquid biopsy of gastric cancer patients: circulating tumor cells and cell-free nucleic acids.

    PubMed

    Tsujiura, Masahiro; Ichikawa, Daisuke; Konishi, Hirotaka; Komatsu, Shuhei; Shiozaki, Atsushi; Otsuji, Eigo

    2014-03-28

    To improve the clinical outcomes of cancer patients, early detection and accurate monitoring of diseases are necessary. Numerous genetic and epigenetic alterations contribute to oncogenesis and cancer progression, and analyses of these changes have been increasingly utilized for diagnostic, prognostic and therapeutic purposes in malignant diseases including gastric cancer (GC). Surgical and/or biopsy specimens are generally used to understand the tumor-associated alterations; however, those approaches cannot always be performed because of their invasive characteristics and may fail to reflect current tumor dynamics and drug sensitivities, which may change during the therapeutic process. Therefore, the importance of developing a non-invasive biomarker with the ability to monitor real-time tumor dynamics should be emphasized. This concept, so called "liquid biopsy", would provide an ideal therapeutic strategy for an individual cancer patient and would facilitate the development of "tailor-made" cancer management programs. In the blood of cancer patients, the presence and potent utilities of circulating tumor cells (CTCs) and cell-free nucleic acids (cfNAs) such as DNA, mRNA and microRNA have been recognized, and their clinical relevance is attracting considerable attention. In this review, we discuss recent developments in this research field as well as the relevance and future perspectives of CTCs and cfNAs in cancer patients, especially focusing on GC. PMID:24696609

  5. Cellular responses induced in vitro by pestheic acid, a fungal metabolite, in a gastric adenocarcinoma cell line (PG100).

    PubMed

    Sousa, J M C; Matos, L A; Alcântara, D F A; Ribeiro, H F; Santos, L S; Oliveira, M N; Brito-Junior, L C; Khayat, A S; Guimarães, A C; Cunha, L A; Burbano, R R; Bahia, M O

    2013-01-01

    There is a constant search for new cancer treatments that are less aggressive and economically affordable. In this context, natural products extracted from plants, fungi, and microorganisms are of great interest. Pestheic acid, or dihidromaldoxin, is a chlorinated diphenylic ether extracted from the phytopathogenic fungus Pestalotiopsis guepinii (Amphisphaeriaceae). We assessed the cytotoxic, cytostatic, and genotoxic effects of pestheic acid in a gastric adenocarcinoma cell line (PG100). A decrease in clonogenic survival was observed. Pestheic acid also induced significant increases in both micronucleus and nucleoplasmic bridge frequency. However, we did not observe changes in cell cycle kinetics or apoptosis induction. Reactive oxygen species induced by diphenylic ethers may explain the genotoxicity and mutagenicity of pestheic acid. The absence of repair checkpoints that we observed is probably due to the fact that the PG100 cell line lacks the TP53 gene, which is common in gastric cancers. Even though pestheic acid has had a clear cytotoxic effect, the minimal inhibitory concentration was high, which shows that pestheic acid is not an active anticancer compound under these conditions. PMID:24114206

  6. [Acetlysalicylic acid, protective antacid effect and lesions of the gastric mucosa. Effect of acetylsalicylic acid and an antacid drug (Gastropulgit Tabs) on the transmural electric potential in the human stomach].

    PubMed

    Caspary, W F; Kausch, H

    1979-08-16

    Antacids are able to prevent acetylsalicylic acid-induced functional and morphological changes of the gastric mucosa. In order to test whether a new antacid in chewing-tablet form (Gastropulgit Tabs) might be able to protect the gastric mucosa from acetylsalicylic acid-induced functional changes similarly to liquid antacids the effect of this antacid on acetylsalicylic acid-induced changes of transmural gastric potential difference was measured in healthy volunteers. The decrease of transmural potential differences induced by 640 mg acetylsalicylic acid could be prevented by simultaneous addition of 2 tablets of Gastropulgit Tabs. Thus the antacid in tablet form is able-like liquid antacids-to protect the gastric mucosa against acetylsalicylic acid-induced functional changes. PMID:468096

  7. Farnesoid X receptor signal is involved in deoxycholic acid-induced intestinal metaplasia of normal human gastric epithelial cells.

    PubMed

    Li, Shu; Chen, Xin; Zhou, Lu; Wang, Bang-Mao

    2015-11-01

    The farnesoid X receptor (FXR) signaling pathway is known to be involved in the metabolism of bile acid, glucose and lipid. In the present study, we demonstrated that 400 µmol/l deoxycholic acid (DCA) stimulation promotes the proliferation of normal human gastric epithelial cells (GES-1). In addition, DCA activated FXR and increased the expression of intestinal metaplasia genes, including caudal-related homeobox transcription factor 2 (Cdx2) and mucin 2 (MUC2). The treatment of FXR agonist GW4064/antagonist guggulsterone (Gug.) significantly increased/decreased the expression levels of FXR, Cdx2 and MUC2 protein in DCA-induced GES-1 cells. GW4064/Gug. also enhanced/reduced the nuclear factor-κB (NF-κB) activity and binding of the Cdx2 promoter region and NF-κB, the most common subunit p50 protein. Taken together, the results indicated that DCA is capable of modulating the expression of Cdx2 and the downstream MUC2 via the nuclear receptor FXR-NF-κB activity in normal gastric epithelial cells. FXR signaling pathway may therefore be involved in the intestinal metaplasia of human gastric mucosa. PMID:26324224

  8. Rabbit gastric ulcer models: comparison and evaluation of acetic acid-induced ulcer and mucosectomy-induced ulcer

    PubMed Central

    Maeng, Jin Hee; Lee, Eunhye

    2013-01-01

    In this study, we examined rabbit gastric ulcer models that can serve as more clinically relevant models. Two types of ulcer model were studied: acetic acid-induced ulcers (AAU) and mucosal resection-induced ulcers (MRU). For AAU, rabbit gastric mucosa was exposed by median laparotomy and treated with bottled acetic acid. MRU was examined as a model for endoscopic mucosal resection (EMR). Normal saline was injected into the submucosal layer and the swollen mucosa was resected with scissors. Endoscopic mucosal resection (EMR) is frequently performed for treatment of early gastric cancers. This procedure inevitably leads to ulcers and bleeding. Bleeding control is the major concern in endoscopic mucosectomy, and some endoscopic hemostatic agents are currently under clinical and preclinical studies. MRU was developed as a model for these induced ulcers and the evaluation of the healing process. The clinical relevancy of those models was compared with that of rat models. Progressive healing was observed for 7 days based on histology. Rabbit models demonstrate round, deep ulcers with clear margins and well-defined healing stages that were difficult to define in rat models. PMID:23825482

  9. Failure of the inhibition of rat gastric mucosal 5-lipoxygenase by novel acetohydroxamic acids to prevent ethanol-induced damage.

    PubMed

    Boughton-Smith, N K; Whittle, B J

    1988-09-01

    1. The role of leukotriene B4 (LTB4) and LTC4 as mediators of gastric mucosal damage following ethanol challenge in vivo has been investigated using two selective 5-lipoxygenase inhibitors, BW A4C and BW A137C. 2. Oral administration of ethanol to rats in vivo, induced macroscopic damage to the gastric mucosa and markedly increased the formation of the 5-lipoxygenase products, LTB4 and LTC4, from the mucosa ex vivo. 3. Pretreatment with the acetohydroxamic acids BW A4C and BW A137C (5-50 mg kg-1 p.o.) dose-dependently reduced ethanol-stimulated LTB4 and LTC4 formation by the gastric mucosa, with an ID50 of approximately 5 mg kg-1 p.o. 4. A single oral dose of BW A4C (20 mg kg-1) induced near-maximal inhibition of mucosal LTB4 formation within 30 min, which was well maintained for 5 h, whereas BW A137C (20 mg kg-1 p.o.) induced maximal inhibition between 30 and 60 min after administration, which then diminished over the subsequent 5 h. 5. The mucosal formation of the cyclo-oxygenase product, 6-keto-prostaglandin F1 alpha, which was unaltered following ethanol challenge, was not inhibited by the acetohydroxamic acids. Likewise, the small increase in mucosal thromboxane B2 formation following challenge was not inhibited by BW A4C. 6. Neither BW A4C nor BW A137C, at doses that almost completely inhibited the mucosal synthesis of LTB4 or LTC4, reduced the macroscopic gastric mucosal damage induced by ethanol. 7. Pretreatment with the lipoxygenase inhibitor BW 755C (5-50 mg kg-1 p.o.) did reduce mucosal damage, but there was a dissociation between the degree of protection and the inhibition of leukotriene biosynthesis. 8. Oral administration of high doses of either BW A4C or BW A137C (300mgkg-1) did not induce macroscopic gastric damage over a 3 h period. 9. These findings suggest that the leukotrienes, LTB4 and LTC4 are not the primary mediators of ethanol-induced acute mucosal damage, but do not exclude their role in more chronic gastric damage and inflammation. PMID

  10. Bile acid and inflammation activate gastric cardia stem cells in a mouse model of Barrett-like metaplasia.

    PubMed

    Quante, Michael; Bhagat, Govind; Abrams, Julian A; Marache, Frederic; Good, Pamela; Lee, Michele D; Lee, Yoomi; Friedman, Richard; Asfaha, Samuel; Dubeykovskaya, Zinaida; Mahmood, Umar; Figueiredo, Jose-Luiz; Kitajewski, Jan; Shawber, Carrie; Lightdale, Charles J; Rustgi, Anil K; Wang, Timothy C

    2012-01-17

    Esophageal adenocarcinoma (EAC) arises from Barrett esophagus (BE), intestinal-like columnar metaplasia linked to reflux esophagitis. In a transgenic mouse model of BE, esophageal overexpression of interleukin-1β phenocopies human pathology with evolution of esophagitis, Barrett-like metaplasia and EAC. Histopathology and gene signatures closely resembled human BE, with upregulation of TFF2, Bmp4, Cdx2, Notch1, and IL-6. The development of BE and EAC was accelerated by exposure to bile acids and/or nitrosamines, and inhibited by IL-6 deficiency. Lgr5(+) gastric cardia stem cells present in BE were able to lineage trace the early BE lesion. Our data suggest that BE and EAC arise from gastric progenitors due to a tumor-promoting IL-1β-IL-6 signaling cascade and Dll1-dependent Notch signaling. PMID:22264787

  11. Effects of acetylsalicylic acid (ASA), ASA plus L-glutamine and L-glutamine on healing of chronic gastric ulcer in the rat.

    PubMed

    Okabe, S; Takeuchi, K; Honda, K; Takagi, K

    1976-01-01

    A chronic gastric ulcer model was produced in rats by the subserosal injection of 20% acetic acid solution (0.015 ml) in order to examine whether (1) acetylsalicylic acid (ASA) irritates the chronic gastric ulcer in active or healed or diminished stage, (2) L-glutamine, given together with ASA, inhibits the adverse effect of ASA. Oral ASA 200 mg/kg/day, given in two divided doses for 10 consecutive days, apparently delayed the healing of the gastric ulcer and irritated the healed ulcer to reulcerate. L-Glutamine, 1,500 mg/kg/day, which was given together with ASA in two divided doses, markedly protected the gastric ulcer both in active and healed stages from the deleterious activity of ASA. PMID:955326

  12. Ethanolic extract of roots from Arctium lappa L. accelerates the healing of acetic acid-induced gastric ulcer in rats: Involvement of the antioxidant system.

    PubMed

    da Silva, Luisa Mota; Allemand, Alexandra; Mendes, Daniel Augusto G B; Dos Santos, Ana Cristina; André, Eunice; de Souza, Lauro Mera; Cipriani, Thales Ricardo; Dartora, Nessana; Marques, Maria Consuelo Andrade; Baggio, Cristiane Hatsuko; Werner, Maria Fernanda

    2013-01-01

    We evaluate the curative efficacy of the ethanolic extract (EET) of roots from Arctium lappa (bardana) in healing of chronic gastric ulcers induced by 80% acetic acid in rats and additionally studies the possible mechanisms underlying this action. Oral administration of EET (1, 3, 10 and 30mg/kg) reduced the gastric lesion area in 29.2%, 41.4%, 59.3% and 38.5%, respectively, and at 10mg/kg promoted significant regeneration of the gastric mucosa, which was confirmed by proliferating cell nuclear antigen immunohistochemistry. EET (10mg/kg) treatment did not increase the gastric mucus content but restored the superoxide dismutase activity, prevented the reduction of glutathione levels, reduced lipid hydroperoxides levels, inhibited the myeloperoxidase activity and reduced the microvascular permeability. In addition, EET reduced the free radical generation and increased scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals in vitro. Furthermore, intraduodenal EET (10 and 30mg/kg) decreased volume and acidity of gastric secretion. Total phenolic compounds were high in EET (Folin-Ciocalteau assay) and the analysis by liquid chromatography-mass spectrometry revealed that the main compounds present in EET were a serie of hydroxycinnamoylquinic acid isomers. In conclusion, these data reveal that EET promotes regeneration of damaged gastric mucosa, probably through its antisecretory and antioxidative mechanisms. PMID:23036453

  13. Molecular characterization of the stomach microbiota in patients with gastric cancer and controls

    SciTech Connect

    Dicksved, J.; Lindberg, M.; Rosenquist, M.; Enroth, H.; Jansson, J.K.; Engstrand, L.

    2009-01-15

    Persistent infection of the gastric mucosa by Helicobacter pylori, can initiate an inflammatory cascade that progresses into atrophic gastritis, a condition associated with reduced capacity for secretion of gastric acid and an increased risk in developing gastric cancer. The role of H. pylori as an initiator of inflammation is evident but the mechanism for development into gastric cancer has not yet been proven. A reduced capacity for gastric acid secretion allows survival and proliferation of other microbes that normally are killed by the acidic environment. It has been postulated that some of these species may be involved in the development of gastric cancer, however their identities are poorly defined. In this study, the gastric microbiota from ten patients with gastric cancer was characterized and compared with five dyspeptic controls using the molecular profiling approach, terminal-restriction fragment length polymorphism (T-RFLP), in combination with 16S rRNA gene cloning and sequencing. T-RFLP analysis revealed a complex bacterial community in the cancer patients that was not significantly different from the controls. Sequencing of 140 clones revealed 102 phylotypes, with representatives from five bacterial phyla (Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria). The data revealed a relatively low abundance of H. pylori and showed that the gastric cancer microbiota was instead dominated by different species of the genera Streptococcus, Lactobacillus, Veillonella and Prevotella. The respective role of these species in development of gastric cancer remains to be determined.

  14. Inhibition of gastric acid secretion by a standardized aqueous extract of Cecropia glaziovii Sneth and underlying mechanism.

    PubMed

    Souccar, C; Cysneiros, R M; Tanae, M M; Torres, L M B; Lima-Landman, M T R; Lapa, A J

    2008-06-01

    Cecropia glazioui Sneth (Cecropiaceae) is used in folk medicine in tropical and subtropical Latin America as cardiotonic, diuretic, hypotensive, anti-inflammatory and anti-asthmatic. The hypotensive/antihypertensive activity of the plant aqueous extract (AE) and isolated butanolic fraction (BuF) has been confirmed and putatively related to calcium channels blockade in vascular smooth musculature [Lapa, A.J., Lima-Landman, M.T.R., Cysneiros, R.M, Borges, A.C.R., Souccar, C., Barreta, I.P., Lima, T.C.M., 1999. The Brazilian folk medicine program to validate medicinal plants - a topic in new antihypertensive drug research. In: Hostettman, K., Gupta, M.P., Marston, A. (Eds.), Proceedings Volume, IOCD/CYTED Symposium, Panamá City, Panamá, 23-26 February 1997. Chemistry, Biological and Pharmacological Properties of Medicinal Plants from the Americas. Harwood Academic Publishers, Amsterdam, pp. 185-196; Lima-Landman, M.T., Borges, A.C., Cysneiros, R.M., De Lima, T.C., Souccar, C., Lapa, A.J., 2007. Antihypertensive effect of a standardized aqueous extract of Cecropia glaziovii Sneth in rats: an in vivo approach to the hypotensive mechanism. Phytomedicine 14, 314-320]. Bronchodilation and antidepressant-like activities of both AE and BuF have been also shown [Delarcina, S., Lima-Landman, M.T., Souccar, C., Cysneiros, R.M., Tanae, M.M., Lapa, A.J., 2007. Inhibition of histamine-induced bronchospasm in guinea pigs treated with Cecropia glaziovi Sneth and correlation with the in vitro activity in tracheal muscles. Phytomedicine 14, 328-332; Rocha, F.F., Lima-Landman, M.T., Souccar, C., Tanae, M.M., De Lima, T.C., Lapa, A.J., 2007. Antidepressant-like effect of Cecropia glazioui Sneth and its constituents -in vivo and in vitro characterization of the underlying mechanism. Phytomedicine 14, 396-402]. This study reports the antiulcer and antisecretory gastric acid activities of the plant AE, its BuF and isolated compounds with the possible mechanism involved. Both AE and Bu

  15. The anti-inflammatory and anti-apoptotic effects of gallic acid against mucosal inflammation- and erosions-induced by gastric ischemia-reperfusion in rats

    PubMed Central

    Mard, Seyyed Ali; Mojadami, Shahnaz; Farbood, Yaghoob; Gharib Naseri, Mohammad Kazem

    2015-01-01

    The present study aimed to evaluate the protective effect of gallic acid on gastric mucosal lesions caused by ischemia-reperfusion (I/R) injury in rat. Forty male rats were randomly divided into sham, control (I/R injury) and three gallic acid-pretreated groups. To induce I/R lesions, the celiac artery was clamped for 30 min and then the clamp was removed to allow reperfusion for 6 hr. Pretreated rats received gallic acid (15, 30 or 60 mg kg-1, intraperitoneally) 30 min prior to the induction of I/R injury. Macroscopic and microscopic evaluations of the areas of ulceration were compared. Samples of gastric mucosa were collected to evaluate the protein expression of pro-apoptotic factor, caspase-3, and pro-inflammatory enzyme, inducible nitric oxide synthase (iNOS) using western blot. Pretreatment with gallic acid decreased the total area of gastric lesions. Gallic acid at 30 mg kg-1 decreased the levels of protein expression of caspase-3 and iNOS induced by I/R injury. Our findings showed the protective effect of gallic acid on gastric mucosa against ischemia-reperfusion injury. This effect of gallic acid was mainly mediated by reducing protein expression of iNOS and caspase-3. PMID:26973766

  16. Air pollution, acid rain and the environment

    SciTech Connect

    Mellanby, K.

    1988-01-01

    This book reports on the Watt Committee's working group on acid rain, which was set up in 1981. The authors consider the relationship between natural and the man-made factors and the effects of possible remedial strategies. In the first phase of the study, the group looked at the fate of airborne pollution, vegetation and soils, freshwater and remedial strategy. In this report, which contains the results of a further phase of study, these topics are included and have been brought up to date. The scope of the report is extended to include buildings and non-living materials. Consideration is given to the problem of acid rain and air pollution worldwide. Emphasis is placed on the United Kingdom. The main conclusion is that more research is necessary on some aspects of acid rain and air pollution, but that some of the reports widespread damage caused by acid rain cannot be confirmed.

  17. Acetylsalicylic Acid Daily vs Acetylsalicylic Acid Every 3 Days in Healthy Volunteers: Effect on Platelet Aggregation, Gastric Mucosa, and Prostaglandin E2 Synthesis.

    PubMed

    Ferreira, Plinio Minghin Freitas; Gagliano-Jucá, Thiago; Zaminelli, Tiago; Sampaio, Marinalva Ferreira; Blackler, Rory Willian; Trevisan, Miriam da Silva; Novaes Magalhães, Antônio Frederico; De Nucci, Gilberto

    2016-07-01

    Substantial platelet inhibition was observed 3 days after a single administration of acetylsalicylic acid 81 mg to healthy volunteers. Here we investigate prostaglandin E2 (PGE2 ) antrum concentrations and gastrointestinal symptoms in two treatment groups: one receiving losartan and acetylsalicylic acid every day and the other receiving losartan every day and acetylsalicylic acid every 3 days. Twenty-eight healthy volunteers from both sexes received either 50 mg losartan and acetylsalicylic acid 81 mg daily or 50 mg losartan and acetylsalicylic acid 81 every 3 days with placebo on the other days. Therapy was delivered for 30 days for both groups. Gastric endoscopy was performed before and after treatment period. Biopsies were collected for PGE2 quantification. Platelet function tests were carried out before and during treatment and TXB2 release on platelet rich plasma was measured. The every 3 day low-dose acetylsalicylic acid regimen produced complete inhibition of platelet aggregation compared to the daily treatment. Thromboxane B2 release was substantially abolished for both groups during treatment. There was no significant difference on the endoscopic score of both treatment groups after the 30-day treatment (P = .215). There was over 50% suppression of antrum PGE2 content on volunteers receiving acetylsalicylic acid daily (P = .0016), while for the every 3 day dose regimen there was no significant difference between pre and post-treatment antrum PGE2 dosages (P = .4193). Since PGE2 is involved in gastric healing, we understand that this new approach could be safer and as efficient as the standard daily therapy on a long-term basis. PMID:26634419

  18. Formation of N-nitrosamine and N-nitrosamino acids from food products and nitrite under simulated gastric conditions.

    PubMed

    Groenen, P J; de Cock-Bethbeder, M W; Bouwman, J; Dhont, J H

    1980-01-01

    Average-sized portions of a variety of food products were reacted with nitrite under realistically simulated gastric conditions. The aqueous incubation medium contained sodium nitrite (10 mg/l) and potassium thiocyanate to mimic the incoming flux of saliva, as well as pepsin, sodium chloride and hydrochloric acid, reflecting the composition of gastric juice. After incubation for 2 hr at 37 degrees C, volatile N-nitrosamines and N-nitrosamino acids were determined in the reaction mixtures. Nitrosodimethylamine (NDMA) was present in the incubation mixtures of smoked mackerel (8.5 micrograms per portion), canned herring (0.66 micrograms per portion) and beer (0.70 micrograms per 'portion'). Smaller amounts per portion, sometimes of other nitrosamines as well, were observed with canned salmon and anchovy, mustard, yoghurt and coffee brew. Negative results were obtained for canned tuna, soya sauce, ketchup, white bread, 'nasi goreng', tea brew and cocoa milk. Nitrosamino acids were detected in the reaction mixtures of smoked mackerel (58 micrograms per portion), soya sauce (24 micrograms per portion) and canned salmon (6.9 micrograms per portion) and in smaller amounts in those of canned herring, anchovy and cocoa milk. In order to reduce the number of analyses to be performed, most products have been studied only after incubation, so that the nitrosamines and nitrosamino acids found may already have been present -- wholly or partly -- in the original products, before incubation. Such is the case for part of the NDMA in the reaction mixture of smoked mackerel and for all the NDMA in beer. The toxicological implications of these findings remain to be established. PMID:7228254

  19. Serum bile acids are higher in humans with prior gastric bypass: potential contribution to improved glucose and lipid metabolism.

    PubMed

    Patti, Mary-Elizabeth; Houten, Sander M; Bianco, Antonio C; Bernier, Raquel; Larsen, P Reed; Holst, Jens J; Badman, Michael K; Maratos-Flier, Eleftheria; Mun, Edward C; Pihlajamaki, Jussi; Auwerx, Johan; Goldfine, Allison B

    2009-09-01

    The multifactorial mechanisms promoting weight loss and improved metabolism following Roux-en-Y gastric bypass (GB) surgery remain incompletely understood. Recent rodent studies suggest that bile acids can mediate energy homeostasis by activating the G-protein coupled receptor TGR5 and the type 2 thyroid hormone deiodinase. Altered gastrointestinal anatomy following GB could affect enterohepatic recirculation of bile acids. We assessed whether circulating bile acid concentrations differ in patients who previously underwent GB, which might then contribute to improved metabolic homeostasis. We performed cross-sectional analysis of fasting serum bile acid composition and both fasting and post-meal metabolic variables, in three subject groups: (i) post-GB surgery (n = 9), (ii) without GB matched to preoperative BMI of the index cohort (n = 5), and (iii) without GB matched to current BMI of the index cohort (n = 10). Total serum bile acid concentrations were higher in GB (8.90 +/- 4.84 micromol/l) than in both overweight (3.59 +/- 1.95, P = 0.005, Ov) and severely obese (3.86 +/- 1.51, P = 0.045, MOb). Bile acid subfractions taurochenodeoxycholic, taurodeoxycholic, glycocholic, glycochenodeoxycholic, and glycodeoxycholic acids were all significantly higher in GB compared to Ov (P < 0.05). Total bile acids were inversely correlated with 2-h post-meal glucose (r = -0.59, P < 0.003) and fasting triglycerides (r = -0.40, P = 0.05), and positively correlated with adiponectin (r = -0.48, P < 0.02) and peak glucagon-like peptide-1 (GLP-1) (r = 0.58, P < 0.003). Total bile acids strongly correlated inversely with thyrotropic hormone (TSH) (r = -0.57, P = 0.004). Together, our data suggest that altered bile acid levels and composition may contribute to improved glucose and lipid metabolism in patients who have had GB. PMID:19360006

  20. Inhibitory effect of nordihydroguaiaretic acid, a plant lignan, on Helicobacter pylori-associated gastric carcinogenesis in Mongolian gerbils.

    PubMed

    Toyoda, Takeshi; Tsukamoto, Tetsuya; Mizoshita, Tsutomu; Nishibe, Sansei; Deyama, Takeshi; Takenaka, Yoshiharu; Hirano, Naoki; Tanaka, Harunari; Takasu, Shinji; Ban, Hisayo; Kumagai, Toshiko; Inada, Ken-Ichi; Utsunomiya, Hirotoshi; Tatematsu, Masae

    2007-11-01

    Recent epidemiological studies have demonstrated that consumption of certain natural products can lower cancer risk in humans. For example, plant-derived lignans have been shown to exert chemopreventive effects against cancer in vitro and in vivo. In the present study, the effects of three such lignans, termed arctiin, arctigenin, and nordihydroguaiaretic acid (NDGA), on the proliferation of Helicobacter pylori and the prevention of H. pylori-associated gastric cancer were investigated in Mongolian gerbils. To examine the effects of arctigenin and NDGA on stomach carcinogenesis, specific pathogen-free male, 5-week-old gerbils were infected with H. pylori, administered 10 p.p.m. N-methyl-N-nitrosourea in their drinking water and fed diets containing various concentrations of lignans until they were killed after 52 weeks. At a dietary level of 0.25%, NDGA significantly decreased the incidence of gastric adenocarcinomas. Arctigenin, in contrast, failed to attenuate neoplasia at a level of 0.1%. Both NDGA and arctigenin significantly reduced serum 8-hydroxy-2'-deoxyguanosine levels at doses of 0.25 and 0.05% (NDGA), and 0.1% (arctigenin). Administration of 0.25% NDGA significantly suppressed the formation of intestinal metaplasia both in the antrum and the corpus. Although all three lignans dose-dependently inhibited the in vitro proliferation of H. pylori, there were no differences in the titers of anti-H. pylori antibodies or the amount of the H. pylori-specific urease A gene among all H. pylori-infected groups. These results suggest that NDGA might be effective for prevention of gastric carcinogenesis. The possible mechanisms appear to be related to inhibitory effects on progression of gastritis and antioxidative activity rather than direct antimicrobial influence. PMID:17894552

  1. Hydroethanolic extract of Baccharis trimera promotes gastroprotection and healing of acute and chronic gastric ulcers induced by ethanol and acetic acid.

    PubMed

    Dos Reis Lívero, Francislaine Aparecida; da Silva, Luisa Mota; Ferreira, Daniele Maria; Galuppo, Larissa Favaretto; Borato, Debora Gasparin; Prando, Thiago Bruno Lima; Lourenço, Emerson Luiz Botelho; Strapasson, Regiane Lauriano Batista; Stefanello, Maria Élida Alves; Werner, Maria Fernanda de Paula; Acco, Alexandra

    2016-09-01

    Ethanol is a psychoactive substance highly consumed around the world whose health problems include gastric lesions. Baccharis trimera is used in folk medicine for the treatment of gastrointestinal disorders. However, few studies have evaluated its biological and toxic effects. To validate the popular use of B. trimera and elucidate its possible antiulcerogenic and cytotoxic mechanisms, a hydroethanolic extract of B. trimera (HEBT) was evaluated in models of gastric lesions. Rats and mice were used to evaluate the protective and antiulcerogenic effects of HEBT on gastric lesions induced by ethanol, acetic acid, and chronic ethanol consumption. The effects of HEBT were also evaluated in a pylorus ligature model and on gastrointestinal motility. The LD50 of HEBT in mice was additionally estimated. HEBT was analyzed by nuclear magnetic resonance, and a high-performance liquid chromatography fingerprint analysis was performed. Oral HEBT administration significantly reduced the lesion area and the oxidative stress induced by acute and chronic ethanol consumption. However, HEBT did not protect against gastric wall mucus depletion and did not alter gastric secretory volume, pH, or total acidity in the pylorus ligature model. Histologically, HEBT accelerated the healing of chronic gastric ulcers in rats, reflected by contractions of the ulcer base. Flavonoids and caffeoylquinic acids were detected in HEBT, which likely contributed to the therapeutic efficacy of HEBT, preventing or reversing ethanol- and acetic acid-induced ulcers, respectively. HEBT antiulcerogenic activity may be partially attributable to the inhibition of free radical generation and subsequent prevention of lipid peroxidation. Our results indicate that HEBT has both gastroprotective and curative activity in animal models, with no toxicity. PMID:27314669

  2. Synergistic antinociceptive effect and gastric safety of the combination of docosahexaenoic acid and indomethacin in rats.

    PubMed

    Arroyo-Lira, Arlette Guadalupe; Rodríguez-Ramos, Fernando; Chávez-Piña, Aracely Evangelina

    2014-07-01

    The use of analgesics is limited by the presence of significant adverse side effects. Thus, combinations of non-steroidal anti-inflammatory drugs (NSAIDs) with other antinociceptive agents are frequently used to decrease these adverse reactions. The aims of this work were to evaluate the antinociceptive interaction of the systemic administration of the combination of DHA and indomethacin through an isobolographic analysis of the theoretical and experimental antinociceptive effect and to demonstrate the gastric safety of the mixture compared with indomethacin alone. Female Wistar rats were orally administered indomethacin (1-10 mg/kg), DHA (100-300 mg/kg), or the DHA-indomethacin mixture at a fixed-ratio combination (1:1, 1:3, 3:1), and the antinociceptive effects of these treatments were evaluated through the formalin (1%) test. An isobolographic analysis was performed to characterize the antinociceptive interaction between DHA and indomethacin. The degree of gastric injury in all of the rats was determined 1 h after the formalin test. The theoretical ED₃₀ values (Zadd) for the 1:1, 1:3, and 3:1 combinations were 73.48 ± 8.96, 37.75 ± 4.50, and 109.2 ± 13.43 mg/kg, p.o., respectively, and the experimental ED30 values (Zexp) were 43.63 ± 5.18, 13.13 ± 1.61, and 54.20 ± 6.53, respectively. The isobolographic analysis showed that the three fixed-ratio combinations studied exhibited a synergistic interaction. Furthermore, the gastric damage induced by indomethacin was abolished when this drug was combined with DHA. These data suggest that the systemic administration of the DHA-indomethacin combination induces a synergistic and gastric safety effect. PMID:24657518

  3. Roles of alpha and beta carbonic anhydrases of Helicobacter pylori in the urease-dependent response to acidity and in colonization of the murine gastric mucosa.

    PubMed

    Bury-Moné, Stéphanie; Mendz, George L; Ball, Graham E; Thibonnier, Marie; Stingl, Kerstin; Ecobichon, Chantal; Avé, Patrick; Huerre, Michel; Labigne, Agnès; Thiberge, Jean-Michel; De Reuse, Hilde

    2008-02-01

    Carbon dioxide occupies a central position in the physiology of Helicobacter pylori owing to its capnophilic nature, the large amounts of carbon dioxide produced by urease-mediated urea hydrolysis, and the constant bicarbonate supply in the stomach. Carbonic anhydrases (CA) catalyze the interconversion of carbon dioxide and bicarbonate and are involved in functions such as CO(2) transport or trapping and pH homeostasis. H. pylori encodes a periplasmic alpha-CA (alpha-CA-HP) and a cytoplasmic beta-CA (beta-CA-HP). Single CA inactivation and double CA inactivation were obtained for five genetic backgrounds, indicating that H. pylori CA are not essential for growth in vitro. Bicarbonate-carbon dioxide exchange rates were measured by nuclear magnetic resonance spectroscopy using lysates of parental strains and CA mutants. Only the mutants defective in the alpha-CA-HP enzyme showed strongly reduced exchange rates. In H. pylori, urease activity is essential for acid resistance in the gastric environment. Urease activity measured using crude cell extracts was not modified by the absence of CA. With intact CA mutant cells incubated in acidic conditions (pH 2.2) in the presence of urea there was a delay in the increase in the pH of the incubation medium, a phenotype most pronounced in the absence of H. pylori alpha-CA. This correlated with a delay in acid activation of the urease as measured by slower ammonia production in whole cells. The role of CA in vivo was examined using the mouse model of infection with two mouse-adapted H. pylori strains, SS1 and X47-2AL. Compared to colonization by the wild-type strain, colonization by X47-2AL single and double CA mutants was strongly reduced. Colonization by SS1 CA mutants was not significantly different from colonization by wild-type strain SS1. However, when mice were infected by SS1 Delta(beta-CA-HP) or by a SS1 double CA mutant, the inflammation scores of the mouse gastric mucosa were strongly reduced. In conclusion, CA

  4. Filling and shielding for postoperative gastric perforations of endoscopic submucosal dissection using polyglycolic acid sheets and fibrin glue

    PubMed Central

    Takimoto, Kengo; Hagiwara, Akeo

    2016-01-01

    Background and study aims: Many medical institutions in Japan perform endoscopic mucosal dissection (ESD) to treat early gastric cancer. Perforations can occur during ESD, and clipping has been reported as useful for treating small pinhole perforations. However, it is often difficult to close postoperative perforations because they usually have large diameters, and the muscle layer around the perforated region is often fragile, so additional open surgery is the only currently used method to treat large perforations and delayed perforations. Another method for large perforation is needed to treat perforations endoscopically. Ono et al. reported a case in which a postoperative perforation was closed using a polyglycolic acid (PGA) sheet and fibrin glue. In addition, it has been used by the authors’ group to repair duodenal injuries that occur during ESD. We report 3 cases in which PGA sheets and fibrin glue were successfully used to repair postoperative gastric perforations endoscopically. This method is simple, safe, and effective, and is a new way to treat large perforations and delayed perforations that occur following ESD. PMID:27556075

  5. The Protective Effects of 18β-Glycyrrhetinic Acid on Helicobacter pylori-Infected Gastric Mucosa in Mongolian Gerbils

    PubMed Central

    Cao, Donghui; Jiang, Jing; You, Lili; Jia, Zhifang; Tsukamoto, Tetsuya; Cai, Hongke; Wang, Shidong; Hou, Zhen; Suo, Yue-er; Cao, Xueyuan

    2016-01-01

    18β-Glycyrrhetinic acid (GRA), a major component of Glycyrrhiza glabra, is widely used therapeutically in clinic. In this study, the effect of GRA on Helicobacter pylori- (H. pylori-) infected gastritis was investigated in Mongolian gerbils in vivo. The gerbils were randomly divided into groups: uninfected; H. pylori-infected; H. pylori + antibiotics (clarithromycin, amoxicillin, and esomeprazole); and H. pylori + GRA. The gastric intraluminal pH value, histopathological changes, and the expression levels of inflammation-related cytokines (IL-1β, TNF-α, COX-2, and iNOS) were investigated. The results showed that, in the H. pylori + GRA group, the intraluminal gastric pH value was lower (2.14 ± 0.08 versus 3.17 ± 0.23, P < 0.05), erosion and hyperplasia were alleviated, the infiltration of neutrophils and mononuclear cells was attenuated (P < 0.05), and the expression levels of TNF-α, IL-1β, COX-2, and iNOS were decreased (P < 0.05) compared with the H. pylori-infected group. There was no significant difference in results between the H. pylori + GRA group and the H. pylori + antibiotics group. This study indicated that GRA significantly attenuated H. pylori-infected gastritis in gerbils and has the potential to be developed as a new therapeutic drug. PMID:27006947

  6. Gastric acid secretion in the dog: a mechanism-based pharmacodynamic model for histamine stimulation and irreversible inhibition by omeprazole.

    PubMed

    Abelö, Angela; Holstein, Björn; Eriksson, Ulf G; Gabrielsson, Johan; Karlsson, Mats O

    2002-08-01

    A mechanism-based pharmacodynamic model was used to describe the inhibitory effect by omeprazole on gastric acid secretion measured after histamine stimulation in the dog. The model identifies parameters that are related to the physiological system, the histamine stimulation, and the irreversible effect of omeprazole on the H+, K(+)-ATPase enzyme. Four different experiments with omeprazole (Exps. 1-4) and two placebo experiments were performed in each of the four Heidenhain pouch dogs used. For placebo and experiments 1-3, saline or omeprazole 0.81 mumol/kg was infused during 3 hr with measurements of histamine-stimulated gastric acid secretion in two periods of 3.5-6.5 hr, one period starting just before the omeprazole infusion and a second later period up to 29 hr post infusion. In experiment 4, 0.18 mumol/kg of omeprazole was infused for 22.5 min and gastric juice was collected for 5 hr post infusion. The response data was well described by the model. Similar parameter estimates were obtained by three different analysis methods; naïve pooling, two-stage method and nonlinear mixed effects modeling. The elimination rate constant for the H+, K(+)-ATPase enzyme, kout, was estimated to be 0.040 hr-1, corresponding to a half-life of about 17 hr. This rate constant determines the duration of omeprazole inhibition after long-term exposure. For short-term omeprazole exposure the duration is determined by the rate constant for transfer of enzymes from active to resting state, estimated to be 1.88 hr-1. The second-order rate constant for histamine stimulation was estimated to be 0.064 hr-1 per histamine concentration unit and the maximum acid secretion was estimated to be 5.0 mmol H+/30 min. The second-order rate constant for the irreversible binding of omeprazole to H+, K(+)-ATPase, kome, was estimated to be 2.39 L/mumol.hr. By modeling the histamine-induced baseline response simultaneously with active treatment, predictions of the response are possible not only

  7. Intestinal concentrations of free and encapsulated dietary medium-chain fatty acids and effects on gastric microbial ecology and bacterial metabolic products in the digestive tract of piglets.

    PubMed

    Zentek, Jürgen; Buchheit-Renko, Susanne; Männer, Klaus; Pieper, Robert; Vahjen, Wilfried

    2012-02-01

    The influence of low dietary levels of free and encapsulated medium-chain fatty acids on their concentrations in the digesta, the gastric microbial ecology and bacterial metabolic products in the gastrointestinal tract (GIT) in weaned piglets was studied. Starting after weaning, 36 piglets were fed a diet without (Control) or with medium-chain fatty acids uncoated (MCFA) or coated with vegetable fat and lecithin (MCFAc). After 4 weeks, the animals were killed, and digesta from the stomach and different sections of the GIT were collected. The concentrations of caprylic (p < 0.001) and capric (p = 0.001) acids were higher in the stomachs of piglets fed diets MCFA and MCFAc compared to the Control group. The concentrations dropped rapidly along the GIT, regardless of encapsulation, and tended to be higher in groups MCFA and MCFAc compared to the Control. Compared to the Control group, ingestion of diet MCFAc led to an increase in the number of eubacteria (p = 0.001), enterobacteriaceae (p < 0.001), clostridial clusters I (p = 0.001) and IV (p = 0.019), Lactobacillus johnsonii (p < 0.001) and Lactobacillus amylovorus (p = 0.001) in gastric contents. A similar trend was seen with diet MCFA. Relative concentrations of short-chain fatty acids were characterised by lower propionic acid levels (p = 0.045), numerically (p < 0.1) higher acetic, lower n-butyric and i-valeric acid concentrations in the small intestine. Lactic acid concentrations were not significantly changed in the GIT, but ammonia concentrations increased (p < 0.001) in the distal small intestine in the MCFA and MCFAc groups. In conclusion, medium-chain fatty acids affected microbial ecology parameters in the gastric contents and bacterial metabolites in the small intestine. At low dietary levels, medium-chain fatty acids may be regarded as modulators of the gastric microbiota in weaned piglets. PMID:22397093

  8. The G-Protein-Coupled Bile Acid Receptor Gpbar1 (TGR5) Inhibits Gastric Inflammation Through Antagonizing NF-κB Signaling Pathway

    PubMed Central

    Guo, Cong; Qi, Hui; Yu, Yingjie; Zhang, Qiqi; Su, Jia; Yu, Donna; Huang, Wendong; Chen, Wei-Dong; Wang, Yan-Dong

    2015-01-01

    Gpbar1 (TGR5), a membrane-bound bile acid receptor, is well-known for its roles in regulation of energy homeostasis and glucose metabolism. Here, we show that mice lacking TGR5 were much more susceptible to lipopolysaccharide (LPS)-induced acute gastric inflammation than wild-type (WT) mice and TGR5 is a negative regulator of gastric inflammation through antagonizing NF-κB signaling pathway. We found that the treatment of TGR5 ligands 23(S)-mCDCA and GPBARA (3-(2-Chlorophenyl)-N-(4-chlorophenyl)-N,5-dimethylisoxazole-4-carboxamide) suppressed gene and protein expression mediated by NF-κB signaling. TGR5 overexpression with ligand treatment inhibited gene expression of interferon-inducible protein 10 (IP-10), TNF-α, and chemoattractant protein-1 (MCP-1) induced by LPS. Furthermore, we revealed that TGR5 activation antagonized NF-κB signaling pathway through suppressing its transcription activity, the phosphorylation of IκBα and p65 translocation, which suggests that TGR5 antagonizes gastric inflammation at least in part by inhibiting NF-κB signaling. These findings identify TGR5 as a negative mediator of gastric inflammation that may serve as an attractive therapeutic tool for human gastric inflammation and cancer. PMID:26696888

  9. Ranitidine treatment in newborn infants: effects on gastric acidity and serum prolactin levels.

    PubMed

    Fontana, M; Tornaghi, R; Petrillo, M; Lora, E; Bianchi Porro, G; Principi, N

    1993-05-01

    Data about the use of ranitidine in the early postnatal period are lacking. In this study, 30 term newborn infants < 2 days old with bleeding erosions in their upper gastrointestinal tracts were treated with ranitidine by continuous i.v. infusion (0.2 mg/kg/h) for 48 h and thereafter by mouth (5 mg/kg b.i.d.) for 1 month. Mean gastric pH (SD) rose from 4.27 (1.62) to 5.70 (0.95) during i.v. infusion; after oral therapy it was still 5.55 (1.25). Serum ranitidine concentrations were 642.4 (376.5) and 321.5 (368.2) ng/ml after i.v. and oral therapy, respectively, with wide interindividual variations; the correlation between serum ranitidine and gastric pH was found to be weak. No untoward effect was observed either on the cardiorespiratory rate or on creatinine and aminotransferase values. Mean serum prolactin concentration after i.v. therapy was found to be lower, although within the reference range, than in control infants; no significant correlation was observed between serum ranitidine and prolactin concentrations. From these data, a < 0.2 mg/kg/h rate seems to be advisable for continuous ranitidine infusion in neonates, whereas the 5 mg/kg b.i.d. regimen could be considered adequate for oral therapy. PMID:8315550

  10. Melatonin is more effective than ascorbic acid and β-carotene in improvement of gastric mucosal damage induced by intensive stress

    PubMed Central

    Akinci, Aysin; Cetin, Asli; Ates, Burhan

    2015-01-01

    Introduction Oxidative stress has been considered to play a primary role in the pathogenesis of stress-induced gastric damage. The aim of this study was to investigate the effects of melatonin, ascorbic acid and β-carotene on stress-induced gastric mucosal damage. Material and methods Fifty-six male Wistar albino rats were divided into control, stress, stress + standard diet, stress + saline, stress + melatonin, stress + ascorbic acid and stress + β-carotene groups. The rats from stress groups were exposed to starvation, immobilization and cold by immobilizing for 8 h at +4°C following 72-hour food restriction. Following stress application, melatonin, ascorbic acid and β-carotene were administered for 7 days. Specimens of gastric tissue were prepared for microscopic and biochemical examinations. Results Mean histopathological damage scores and mean tissue malondialdehyde levels were significantly decreased but mean tissue glutathione levels and glutathione peroxidase and superoxide dismutase activities were increased in treatment groups vs. stress groups in general. Mean histopathological damage scores of the stress + Mel group was lower than those of stress + D, stress + S, stress + β-car (p < 0.05) and stress + Asc groups (p < 0.005). Additionally, mean tissue catalase activity of the stress + Mel group was higher than that of stress + S (p < 0.005), stress + D (p < 0.05) and stress + β-car groups (p < 0.05). Conclusions Melatonin is more effective than ascorbic acid and β-carotene in improvement of gastric damage induced by intensive stress. We suggest that as well as the direct antioxidant and free radical scavenging potency of melatonin, its indirect effect via the brain-gut axis might account for its greater beneficial action against stress-induced gastric damage. PMID:26528359

  11. Influence of five neutralizing products on intra-oral pH after rinsing with simulated gastric acid.

    PubMed

    Lindquist, Birgitta; Lingström, Peter; Fändriks, Lars; Birkhed, Dowen

    2011-08-01

    The aetiology of dental erosion may be of both extrinsic and intrinsic origin. The aim of the present study was to test the ability of various neutralizing products to raise the low intra-oral pH after an erosive exposure, in this case to gastric acid, which was simulated using hydrochloric acid (HCl). Eleven adults participated. They rinsed with 10 ml of 10 mM HCl (pH 2) or 10 ml of 100 mM HCl (pH 1) for 1 min, after which the pH was measured intra-orally for up to 30 min at four sites (two approximal, one buccal, and the dorsum of the tongue). After rinsing with the two acid solutions (pH 1 and pH 2), the following products were used: (i) antacid tablet; (ii) gum arabic lozenge; (iii) mineral water; (iv) milk; and (v) tap water (positive control). The negative control was no product use. The five test products were used for 2 min after the erosive challenge. All the products produced an initially higher pH compared with the negative control. The antacid tablet resulted in the greatest and most rapid increase in pH, followed by the lozenge. In dental practice, the use of any of the neutralizing products tested, especially the antacid tablet, could be recommended in order to increase the intra-oral pH after an erosive challenge. PMID:21726291

  12. A novel retinoic acid analog, 4-amino-2-trifluoromethyl-phenyl retinate, inhibits gastric cancer cell growth.

    PubMed

    Hu, Kong-Wang; Pan, Xiao-Hua; Chen, Fei-Hu; Qin, Rong; Wu, Li-Ming; Zhu, Hua-Gang; Wu, Fan-Rong; Ge, Jin-Fang; Han, Wen-Xiu; Yin, Chun-Lin; Li, Hong-Jun

    2014-02-01

    Retinoic acid (RA) analogs have been used in the treatment of a variety of cancers; however, their application is limited due to serious therapy-related sequelae. In the present study, the effects of a novel RA analog, 4-amino-2-trifluoromethyl-phenyl retinate (ATPR), on the growth of gastric cancer cells were evaluated. Three gastric cancer cell lines, AGS, MKN-74 and SC-M1, were treated with either all‑trans retinoic acid (ATRA) or ATPR, and their growth and distribution in different cell cycle phases were assessed using an MTT assay and propidium iodide (PI) staining followed by flow cytometry. The binding affinity of ATPR to the retinoic acid receptors, retinoic acid receptor-α (RAR-α) and retinoid X receptor-α (RXR-α), was determined using ligand-binding assays. Activator protein-1 (AP-1) activity was measured using a luciferase reporter assay. Western blot analysis was used to determine cyclin E, Bcl-2 and Bax protein expression. ATPR preferentially bound RXR-α (0.04 nM) as compared with RAR-α (20.96 nM). Although both ATRA and ATPR inhibited the growth of AGS, MKN-74 and SC-M1 cells in a dose-dependent manner, a significantly greater inhibitory effect was observed with treatment with 5 and 500 µM ATPR for 3 days (P<0.05). In addition, ATPR (50 µM), but not ATRA, significantly increased the population of AGS and MKN-74 cells in the subG1 phase and decreased the Bcl-2/Bax ratio (P<0.05). Furthermore, in MNK-74 and SC-M1 cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) and 5 or 10 µM of ATPR significantly suppressed the activity of the AP-1 reporter as compared to treatment with ATRA (P<0.05). Thus, ATPR inhibits cancer cell proliferation to a greater extent compared to ATRA, possibly through the RXR-mediated inhibition of AP-1 activity. PMID:24317440

  13. The relation between gastric acid secretion and body habitus, blood groups, smoking, and the subsequent development of dyspepsia and duodenal ulcer

    PubMed Central

    Novis, B. H.; Marks, I. N.; Bank, S.; Sloan, A. W.

    1973-01-01

    One hundred and seventy-six students free of gastrointestinal disease were studied to establish normal acid secretion values for healthy male and female students by the augmented histamine test and to re-examine the relationship between gastric acid secretion and ABO blood groups, body weight, fat-free body mass, height, degree of ectomorphy and mesomorphy, the number of cigarettes smoked per day, and serum cholesterol. A prospective study was then carried out on gastric acid secretion and the subsequent development after 10 years of duodenal ulcers or dyspepsia. Young, healthy medical students have a fairly high mean basal and maximal acid output. There was very little difference in the mean acid outputs of the various ABO blood groups. A significant correlation was shown between acid output and body weight and fat-free body mass, but not with the other measurements of body build. Basal acid output was also related to the number of cigarettes smoked per day. Three students who subsequently developed duodenal ulcers all had a preexistent high level of acid secretion. The acid output was, however, similar in the groups who developed significant or minor dyspepsia or who remained asymptomatic. PMID:4696532

  14. Expression of gastric antisecretory and prostaglandin E receptor binding activity of misoprostol by misoprostol free acid.

    PubMed

    Tsai, B S; Kessler, L K; Stolzenbach, J; Schoenhard, G; Bauer, R F

    1991-05-01

    In enriched canine parietal cell preparations, misoprostol, an analog of prostaglandin E1 methyl ester, was rapidly deesterified to misoprostol free acid. Under this circumstance, misoprostol and misoprostol free acid exhibited equal antisecretory potency against histamine-stimulated acid secretion and bound equally well to prostaglandin E receptors. When the deesterification of misoprostol was inhibited by paraoxon, an esterase inhibitor, the antisecretory and receptor binding activity of misoprostol was markedly reduced, with potency much less than misoprostol free acid. These results indicate that misoprostol free acid is the active biological form of misoprostol that binds to prostaglandin E receptors and mediates the antisecretory action of misoprostol. PMID:1850690

  15. Engineering of lipid prodrug-based, hyaluronic acid-decorated nanostructured lipid carriers platform for 5-fluorouracil and cisplatin combination gastric cancer therapy

    PubMed Central

    Qu, Chun-Ying; Zhou, Min; Chen, Ying-wei; Chen, Mei-mei; Shen, Feng; Xu, Lei-Ming

    2015-01-01

    Purpose The first-line chemotherapy treatment protocol for gastric cancer is combination chemotherapy of 5-fluorouracil (5-FU) and cisplatin (CDDP). The aim of this study was to engineer prodrug-based nanostructured lipid carriers (NLC) platform for codelivery of 5-FU and CDDP to enhance therapy and decrease toxicity. Methods First, 5-FU-stearic acid lipid conjugate was synthesized by two steps. Second, 5-FU-stearic acid prodrug and CDDP were loaded in NLC. Finally, hyaluronic acid (HA) was coated onto NLC surface. Average size, zeta potential, and drug loading capacity of NLC were evaluated. Human gastric cancer cell line BGC823 (BGC823 cells) was used for the testing of in vitro cytotoxicity assays. In vivo antitumor activity of NLC was evaluated in mice bearing BGC823 cells model. Results HA-coated 5-FU-stearic acid prodrug and CDDP-loaded NLC (HA-FU/C-NLC) showed a synergistic effect in combination therapy and displayed the greatest antitumor activity than all of the free drugs or uncoated NLC in vitro and in vivo. Conclusion This work reveals that HA-coated NLC could be used as a novel carrier to code-liver 5-FU and CDDP for gastric cancer therapy. HA-FU/C-NLC could be a promising targeted and combinational therapy in nanomedicine. PMID:26089667

  16. A dark brown roast coffee blend is less effective at stimulating gastric acid secretion in healthy volunteers compared to a medium roast market blend.

    PubMed

    Rubach, Malte; Lang, Roman; Bytof, Gerhard; Stiebitz, Herbert; Lantz, Ingo; Hofmann, Thomas; Somoza, Veronika

    2014-06-01

    Coffee consumption sometimes is associated with symptoms of stomach discomfort. This work aimed to elucidate whether two coffee beverages, containing similar amounts of caffeine, but differing in their concentrations of (β) N-alkanoyl-5-hydroxytryptamides (C5HTs), chlorogenic acids (CGAs), trigonelline, and N-methylpyridinium (N-MP) have different effects on gastric acid secretion in healthy volunteers. The intragastric pH after administration of bicarbonate with/without 200 mL of a coffee beverage prepared from a market blend or dark roast blend was analyzed in nine healthy volunteers. Coffee beverages were analyzed for their contents of C5HT, N-MP, trigonelline, CGAs, and caffeine using HPLC-DAD and HPLC-MS/MS. Chemical analysis revealed higher concentrations of N-MP for the dark brown blend (87 mg/L) compared to the market blend coffee (29 mg/L), whereas concentrations of C5HT (0.012 versus 0.343 mg/L), CGAs (323 versus 1126 mg/L), and trigonelline (119 versus 343 mg/L) were lower, and caffeine concentrations were similar (607 versus 674 mg/mL). Gastric acid secretion was less effectively stimulated after administration of the dark roast blend coffee compared to the market blend. Future studies are warranted to verify whether a high ratio of N-MP to C5HT and CGAs is beneficial for reducing coffee-associated gastric acid secretion. PMID:24510512

  17. Effect of deoxycholic acid on Ca2+ movement, cell viability and apoptosis in human gastric cancer cells.

    PubMed

    Chien, Jau-Min; Chou, Chiang-Ting; Liang, Wei-Zhe; Cheng, Jin-Shiung; Chang, Hong-Tai; Tseng, Hui-Wen; Kuo, Soong-Yu; Kuo, Chun-Chi; Chen, Fu-An; Shieh, Pochuen; Ho, Chin-Man; Lin, Jia-Rong; Kuo, Daih-Huang; Jan, Chung-Ren

    2015-02-01

    Deoxycholic acid (DOA) is one of the secondary bile acids used as a mild detergent for the isolation of membrane associated proteins. This study examined whether the secondary bile acid, DOA, altered Ca(2+) movement, cell viability and apoptosis in SCM1 human gastric cancer cells. The Ca(2+)-sensitive fluorescent dye fura-2 was used to measure [Ca(2+)]i. DOA-evoked [Ca(2+)]i rises concentration dependently. The response was reduced by removing extracellular Ca(2+). DOA-evoked Ca(2+) entry was inhibited by store-operated Ca(2+) channel inhibitors (nifedipine, econazole and SKF96365), the protein kinase C (PKC) activator phorbol 12-myristate 13 acetate (PMA) and the PKC inhibitor GF109203X. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) abolished DOA-evoked [Ca(2+)]i rises. Conversely, treatment with DOA abolished TG-evoked [Ca(2+)]i rises. Inhibition of phospholipase C with U73122 abolished DOA-evoked [Ca(2+)]i rises. At 100-500 μM, DOA decreased cell viability, which was not changed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). DOA between 100 and 300 μM also induced apoptosis. Collectively, in SCM1 cells, DOA-induced [Ca(2+)]i rises by evoking phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via store-operated Ca(2+) channels. DOA also caused Ca(2+)-independent apoptosis. PMID:25406855

  18. Effect of Roux-en-Y Gastric Bypass Surgery on Bile Acid Metabolism in Normal and Obese Diabetic Rats

    PubMed Central

    Bhutta, Hina Y; Rajpal, Neetu; White, Wendy; Freudenberg, Johannes M.; Liu, Yaping; Way, James; Rajpal, Deepak; Cooper, David C.; Young, Andrew; Tavakkoli, Ali; Chen, Lihong

    2015-01-01

    In addition to classic functions of facilitating hepatobiliary secretion and intestinal absorption of lipophilic nutrients, bile acids (BA) are also endocrine factors and regulate glucose and lipid metabolism. Recent data indicate that antiobesity bariatric procedures e.g. Roux-en-Y gastric bypass surgery (RYGB), which also remit diabetes, increase plasma BAs in humans, leading to the hypothesis that BAs may play a role in diabetes resolution following surgery. To investigate the effect of RYGB on BA physiology and its relationship with glucose homeostasis, we undertook RYGB and SHAM surgery in Zucker diabetic fatty (ZDF) and normoglycemic Sprague Dawley (SD) rats and measured plasma and fecal BA levels, as well as plasma glucose, insulin, Glucagon like peptide 1 (GLP-1) and Peptide YY (PYY), 2 days before and 3, 7, 14 and 28 days after surgery. RYGB decreased body weight and increased plasma GLP-1 in both SD and ZDF rats while decreasing plasma insulin and glucose in ZDF rats starting from the first week. Compared to SHAM groups, both SD-RYGB and ZDF-RYGB groups started to have increases in plasma total BAs in the second week, which might not contribute to early post-surgery metabolic changes. While there was no significant difference in fecal BA excretion between SD-RYGB and SD-SHAM groups, the ZDF-RYGB group had a transient 4.2-fold increase (P<0.001) in 24-hour fecal BA excretion on post-operative day 3 compared to ZDF-SHAM, which paralleled a significant increase in plasma PYY. Ratios of plasma and fecal cholic acid/chenodeoxycholic acid derived BAs were decreased in RYGB groups. In addition, tissue mRNA expression analysis suggested early intestinal BA reabsorption and potentially reduced hepatic cholic acid production in RYGB groups. In summary, we present novel data on RYGB-mediated changes in BA metabolism to further understand the role of BAs in RYGB-induced metabolic effects in humans. PMID:25798945

  19. Effects of β-glucan pretreatment on acetylsalicylic acid-induced gastric damage: An experimental study in rats

    PubMed Central

    Ozkan, Orhan Veli; Ozturk, Oktay Hasan; Aydin, Mehmet; Yilmaz, Nigar; Yetim, Ibrahim; Nacar, Ahmet; Oktar, Suleyman; Sogut, Sadik

    2010-01-01

    Background: NSAIDs have been found to induce gastrointestinal tract damage. Recently, it has been suggested that this might be mediated by lipid peroxidation. Objective: The aim of this study was to assess the potential protective effects of β-glucan against acetylsalicylic acid (ASA-induced gastric damage by means of its antioxidant capacity in an experimental rat model. Methods: Thirty-two male Wistar albino rats (200–250 g) were randomized into 4 groups consisting of 8 rats each. The β-glucan group received 50 mg/kg β-glucan once a day for 10 days and 30 minutes before anesthesia. The ASA group received saline once a day for 10 days and 300 mg/kg (20 mg/mL) ASA as a single dose, 4 hours before anesthesia. The ASA+β-glucan group was administered 50 mg/kg β-glucan once a day for 10 days and 30 minutes before anesthesia. Additionally, 300 mg/kg (20 mg/mL) ASA was administered as a single dose, 4 hours before anesthesia. The control group received saline once a day for 10 days and 30 minutes before anesthesia. All medications were administered by intragastric gavage. The stomach from each rat was dissected and divided into 2 parts for histologic and biochemical analysis. Gastric tissue malondialdehyde (MDA), nitric oxide (NO) levels, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were determined for oxidative parameter analysis. Results: The gastroprotective and antioxidant effects of β-glucan appeared to attenuate the ASA-induced gastric tissue damage. Compared with the control group, MDA and NO levels and CAT and GSH-Px activities were significantly increased in the stomachs of ASA-treated rats (MDA, 4.12 [0.44] to 13.41 [1.05] μmol/L; NO, 8.04 [7.25–9.10] vs 30.35 [22.34–37.95] μmol/g protein; CAT, 0.050 [0.004] to 0.083 [0.003] k/g protein; GSH-Px, 0.57 [0.42–0.66] to 1.55 [1.19–1.76] U/L; all, P < 0.001), whereas SOD activity was significantly decreased in the same group (291 [29] to 124 [6] U/mL; P

  20. Occupation and gastric cancer.

    PubMed

    Raj, A; Mayberry, J F; Podas, T

    2003-05-01

    Gastric cancer is a cause of significant morbidity and mortality. There are several risk factors, with occupation emerging as one of these. There is considerable evidence that occupations in coal and tin mining, metal processing, particularly steel and iron, and rubber manufacturing industries lead to an increased risk of gastric cancer. Other "dusty" occupations-for example, wood processing, or work in high temperature environments have also been implicated but the evidence is not strong. The mechanism of pathogenesis of gastric cancer is unclear and the identification of causative agents can be difficult. Dust is thought to be a contributor to the pathological process, but well known carcinogens such as N-nitroso compounds have been detected in some environments. Further research on responsible agents is necessary and screening for detection of precursor gastric cancer lesions at the workplace merits consideration. PMID:12782770

  1. Occupation and gastric cancer

    PubMed Central

    Raj, A; Mayberry, J; Podas, T

    2003-01-01

    Gastric cancer is a cause of significant morbidity and mortality. There are several risk factors, with occupation emerging as one of these. There is considerable evidence that occupations in coal and tin mining, metal processing, particularly steel and iron, and rubber manufacturing industries lead to an increased risk of gastric cancer. Other "dusty" occupations—for example, wood processing, or work in high temperature environments have also been implicated but the evidence is not strong. The mechanism of pathogenesis of gastric cancer is unclear and the identification of causative agents can be difficult. Dust is thought to be a contributor to the pathological process, but well known carcinogens such as N-nitroso compounds have been detected in some environments. Further research on responsible agents is necessary and screening for detection of precursor gastric cancer lesions at the workplace merits consideration. PMID:12782770

  2. Effects of caffeic acid phenethyl ester on matrix molecules and angiogenetic and anti-angiogenetic factors in gastric cancer cells cultured on different substrates.

    PubMed

    Kosova, F; Kurt, F O; Olmez, E; Tuğlu, I; Arı, Z

    2016-01-01

    Migration, invasion, metastasis and angiogenesis associated with cancer depend on the surrounding microenvironment. Angiogenesis, the growth of new capillaries, is a regulator of cancer growth and a useful target for cancer therapy. We examined matrix protein interactions in a gastric cancer cell culture that was treated with different doses of caffeic acid (3,4-dihydroxycinnamic acid) phenethyl ester (CAPE). We also investigated the relations among the levels of vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), endostatin (ES) and trombospondin-1 (TSP-1). Cytotoxity of CAPE was measured using the 3-(4,5-dmethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. We examined the behavior of cells on laminin and collagen I coated surfaces in response to the angiogenic effect of these matrix molecules. We examined the protein alterations of these matrix molecules immunohistochemically and measured the levels of VEGF, MMP-9, ES and TSP-1 using the ELISA test. We showed that application of CAPE to the gastric cancer cell line on tissue culture plastic, laminin and collagen I significantly decreased the VEGF and MMP-9 protein levels. We found that TSP-1 levels were increased significantly in the gastric cancer cells after application of CAPE. The protein levels of gastric cancer cells also were increased significantly when tissue was cultured on laminin and collagen I. Application of CAPE to cells on laminin or collagen I coated surfaces significantly increased all of the proteins except ES. ES levels were increased on the collagen I covered surfaces, but the laminin surface decreased the levels of ES significantly. We demonstrated the beneficial effect of CAPE on a gastric cancer cell line including inhibition of proliferation and induction of some proteins that might be related to decreased angiogenesis. PMID:26523612

  3. All-trans retinoic acid decreases susceptibility of a gastric cancer cell line to lymphokine-activated killer cytotoxicity.

    PubMed Central

    Chao, T. Y.; Jiang, S. Y.; Shyu, R. Y.; Yeh, M. Y.; Chu, T. M.

    1997-01-01

    All-trans retinoic acid (RA) was previously shown to regulate the growth of gastric cancer cells derived from the cell line SC-M1. This study was designed to investigate the effect of RA on the sensitivity of SC-M1 cells to lymphokine-activated killer (LAK) activity. RA at the concentration range of 0.001-10 microM was shown to induce SC-M1 cells to exhibit resistance to LAK activity in a dose-dependent manner. A kinetics study indicated that a significantly increased resistance was detected after 2 days of co-culturing SC-M1 cells with RA and reached a maximum after 6 days of culture. Similar results were obtained from two other cancer cell lines: promyelocytic leukaemia HL-60 and hepatic cancer Hep 3B. A binding assay demonstrated that the binding efficacy between target SC-M1 cells and effector LAK cells was not altered by RA. Flow cytometric analyses revealed that RA exhibited no effect on the expression of cell surface molecules, including HLA class I and class II antigens, intercellular adhesion molecule-1 and -2, and lymphocyte function antigen-3. Cell cycle analysis revealed that culture of SC-M1 cells with RA resulted in an increase in G0/G1 phase and a decrease in S phase, accompanied by a decrease in cyclin A and cyclin B1 mRNA as determined by Northern blot analysis. Additionally, RA was shown to enhance the expression of retinoic acid receptor alpha (RAR alpha) in SC-M1 cells, and to have no effect on the expression of RARbeta or RARgamma. Taken together, these results indicate that RA can significantly increase gastric cancer cells SC-M1 to resist LAK cytotoxicity by means of a cytostatic effect through a mechanism relating to cell cycle regulation. The prevailing ideas, such as a decrease in effector to target cell binding, a reduced MHC class I antigen expression or an altered RARbeta expression, are not involved. Images Figure 4 Figure 5 PMID:9155047

  4. Effect of preduodenal lipase inhibition in suckling rats on dietary octanoic acid (C8:0) gastric absorption and plasma octanoylated ghrelin concentration.

    PubMed

    Lemarié, F; Cavalier, J-F; Garcia, C; Boissel, F; Point, V; Catheline, D; Legrand, P; Carrière, F; Rioux, V

    2016-09-01

    Part of medium chain fatty acids (MCFAs) coming from dietary triglycerides (TGs) can be directly absorbed through the gastric mucosa after the action of preduodenal lipase (lingual lipase in the rat). MCFA gastric absorption, particularly that of octanoic acid (C8:0), may have a physiological importance in the octanoylation of ghrelin, the orexigenic gastric peptide acting as an endogenous ligand of the hypothalamic growth hormone secretagogue receptor 1a (GHSR-1a). However, the amount of C8:0 absorbed in the stomach and its metabolic fate still haven't been clearly characterized. The purpose of the present study was to further characterize and quantify the importance of preduodenal lipase activity on the release and gastric absorption of dietary C8:0 and on the subsequent ghrelin octanoylation in the stomach mucosa. Fifteen days old rats received fat emulsions containing triolein or [1,1,1-(13)C]-Tri-C8:0 and a specific inhibitor of preduodenal lipase, 5-(2-(benzyloxy)ethoxy)-3-(3-phenoxyphenyl)-1,3,4-oxadiazol-2(3H)-one or BemPPOX. The fate of the (13)C-C8:0 was followed in rat tissues after 30 and 120min of digestion and octanoylated ghrelin was measured in the plasma. This work (1) demonstrates that part of C8:0 coming from Tri-C8:0 is directly absorbed at the gastric level, (2) allows the estimation of C8:0 gastric absorption level (1.3% of the (13)C-C8:0 in sn-3 position after 30min of digestion), as well as (3) the contribution of rat lingual lipase to total lipolysis and to duodenal absorption of dietary FAs (at least 30%), (4) shows no short-term effect of dietary Tri-C8:0 consumption and subsequent increase of C8:0 gastric tissue content on plasma octanoylated ghrelin concentration. PMID:27317984

  5. Gastric or rectal instillation of short-chain fatty acids stimulates epithelial cell proliferation of small and large intestine in rats.

    PubMed

    Ichikawa, Hirofumi; Shineha, Ryuzaburo; Satomi, Susumu; Sakata, Takashi

    2002-05-01

    Short-chain fatty acids stimulate gut epithelial cell proliferation in vivo, although the difference between oral and rectal routes is unknown. Accordingly, we examined the effect of oral or rectal administration of these acids. We instilled a mixture of acetic acid, propionic acid, and n-butyric acid (150, 60, and 60 mmol/liter, respectively; pH 6.5) or saline (270 mM, pH 6.5) into the stomach (2 ml) or rectum (1 ml) three times daily for five days in rats fed an elemental diet. We measured crypt cell production rate of the jejunum, ileum, and distal colon of these rats. The crypt cell production rate of these segments was higher in rats with gastric or rectal instillation of short-chain fatty acids than in saline controls. The rectal route was slightly more effective than the gastric route. The above results indicated that the instillation of short-chain fatty acids orally or rectally stimulated gut epithelial cell proliferation. PMID:12018914

  6. Efficacy of long-term therapy with low doses of omeprazole in the control of gastric acid secretion in Zollinger-Ellison syndrome patients.

    PubMed

    Corleto, V; Annibale, B; D'Ambra, G; Saggioro, A; Ferrua, B; Cassetta, M R; Delle Fave, G

    1993-04-01

    Thirteen patients with Zollinger-Ellison syndrome were investigated: 8 without, and 5 with, previous gastric surgery. After 7-34 months of treatment with famotidine, 8 out of 13 patients were resistant to this drug. Omeprazole 60 mg/day was administered to these 8 patients; after one month, the dose was reduced to 40 mg/day, and after another month to 20 mg/day. Basal acid secretion was inhibited by every dose of omeprazole. The patients were then treated with a low dose (20 mg/day) of omeprazole for a longer period. Periodic clinical and endoscopic assessments, and measurement of basal acid secretion showed the efficacy of this low dose of omeprazole in our Zollinger-Ellison syndrome patients. The drug was discontinued after 12-32 months of omeprazole treatment, and gastric acid recovery was evaluated. Four patients recovered 50% of their 'initial basal acid secretion' after 5 days, while two patients who had been treated with omeprazole for a longer time (30-32 months) recovered only 38 and 40%, respectively, of their 'initial basal acid secretion' at the tenth day. Our results indicate that the omeprazole dosage to be used in the treatment of Zollinger-Ellison syndrome must be chosen principally on the basis of basal acid secretion determination. A low daily dose of omeprazole is able to control acid secretion in Zollinger-Ellison syndrome for a long period (10-30 months). The slow recovery of gastric secretory function demonstrates the prolonged inhibitory effects of omeprazole. PMID:8485270

  7. Body Position Modulates Gastric Emptying and Affects the Post-Prandial Rise in Plasma Amino Acid Concentrations Following Protein Ingestion in Humans

    PubMed Central

    Holwerda, Andrew M.; Lenaerts, Kaatje; Bierau, Jörgen; van Loon, Luc J. C.

    2016-01-01

    Dietary protein digestion and amino acid absorption kinetics determine the post-prandial muscle protein synthetic response. Body position may affect gastrointestinal function and modulate the post-prandial rise in plasma amino acid availability. We aimed to assess the impact of body position on gastric emptying rate and the post-prandial rise in plasma amino acid concentrations following ingestion of a single, meal-like amount of protein. In a randomized, cross-over design, eight healthy males (25 ± 2 years, 23.9 ± 0.8 kg·m−2) ingested 22 g protein and 1.5 g paracetamol (acetaminophen) in an upright seated position (control) and in a −20° head-down tilted position (inversion). Blood samples were collected during a 240-min post-prandial period and analyzed for paracetamol and plasma amino acid concentrations to assess gastric emptying rate and post-prandial amino acid availability, respectively. Peak plasma leucine concentrations were lower in the inversion compared with the control treatment (177 ± 15 vs. 236 ± 15 mmol·L−1, p < 0.05), which was accompanied by a lower plasma essential amino acid (EAA) response over 240 min (31,956 ± 6441 vs. 50,351 ± 4015 AU; p < 0.05). Peak plasma paracetamol concentrations were lower in the inversion vs. control treatment (5.8 ± 1.1 vs. 10.0 ± 0.6 mg·L−1, p < 0.05). Gastric emptying rate and post-prandial plasma amino acid availability are significantly decreased after protein ingestion in a head-down tilted position. Therefore, upright body positioning should be considered when aiming to augment post-prandial muscle protein accretion in both health and disease. PMID:27089362

  8. Kir1.1 (ROMK) and Kv7.1 (KCNQ1/KvLQT1) are essential for normal gastric acid secretion: importance of functional Kir1.1.

    PubMed

    Vucic, Esad; Alfadda, Tariq; MacGregor, Gordon G; Dong, Ke; Wang, Tong; Geibel, John P

    2015-07-01

    Potassium channels comprise the apical leak pathway supplying extracellular K(+) for exchange with protons by the gastric H(+), K(+)-ATPase and provide potential therapeutic targets for inhibiting gastric acid secretion. The Kir1.1 (ROMK) potassium channel mediates the high capacity K(+) recycling necessary for NaCl reabsorption in the thick ascending limb of the kidney, and this channel exhibits functional and regulatory characteristic well suited for K(+) recycling by gastric parietal cells. We report here that Kir1.1 channels are required for gastric acid secretion and that this channel participates with Kv7.1 (KCNQ1/KvLQT1) in the potassium recycling process. We show that Kir1.1 colocalizes with the β-subunit of H(+), K(+)-ATPase in gastric parietal cells of Kir1.1 wild-type mice. In Kir1.1-deficient mice, gastric mucosal morphology, as well as parietal cell number, proliferation index, and ultrastructure were normal but secretagogue-stimulated gastric acid secretion in whole stomach and perfused gastric glands was absent. Luminal application of potassium-restored acid secretion in perfused gastric glands from Kir1.1-deficient as well as barium-blocked wild-type mice. In wild-type mice, both luminal Tertiapin-Q, an inhibitor of Kir1.1, as well as XE991, an inhibitor of Kv7.1, reduced proton secretion. We propose that Kir1.1 and Kv7.1 channels collaborate in potassium and current recycling across the apical pole of parietal cells. PMID:25127675

  9. Novel acid resistance genes from the metagenome of the Tinto River, an extremely acidic environment.

    PubMed

    Guazzaroni, María-Eugenia; Morgante, Verónica; Mirete, Salvador; González-Pastor, José E

    2013-04-01

    Microorganisms that thrive in acidic environments are endowed with specialized molecular mechanisms to survive under this extremely harsh condition. In this work, we performed functional screening of six metagenomic libraries from planktonic and rhizosphere microbial communities of the Tinto River, an extremely acidic environment, to identify genes involved in acid resistance. This approach has revealed 15 different genes conferring acid resistance to Escherichia coli, most of which encoding putative proteins of unknown function or previously described proteins not known to be related to acid resistance. Moreover, we were able to assign function to one unknown and three hypothetical proteins. Among the recovered genes were the ClpXP protease, the transcriptional repressor LexA and nucleic acid-binding proteins such as an RNA-binding protein, HU and Dps. Furthermore, nine of the retrieved genes were cloned and expressed in Pseudomonas putida and Bacillus subtilis and, remarkably, most of them were able to expand the capability of these bacteria to survive under severe acid stress. From this set of genes, four presented a broad-host range as they enhance the acid resistance of the three different organisms tested. These results expand our knowledge about the different strategies used by microorganisms to survive under extremely acid conditions. PMID:23145860

  10. Turbulent acidic jets and plumes injected into an alkaline environment

    NASA Astrophysics Data System (ADS)

    Ulpre, Hendrik

    2012-11-01

    The characteristics of a strong acidic turbulent jet or plume injected into an alkaline environment comprising of a weak/strong base are examined theoretically and experimentally. A chemistry model is developed to understand how the pH of a fluid parcel of monoprotic acid changes as it is diluted and reacts with the ambient fluid. A standard fluid model, based on a top-hat model for acid concentration and velocity is used to express how the dilution of acid varies with distance from the point of discharge. These models are applied to estimate the point of neutralisation and the travel time with distance within the jet/plume. An experimental study was undertaken to test the theoretical results. These experiments involved injecting jets or vertical plumes of dilute nitric acid into a large tank containing a variety of base salts dissolved in water. The injected fluid contained litmus indicator dye which showed a change in colour from red to blue close to the point of neutralisation. In order to obtain a range of neutralisation distances, additional basic salts were added to the water to increase its pH buffering capacity. The results are applied to discuss the environmental implications of an acidic jet/plume injected into the sea off the South East coast of Great Britain.

  11. Biosynthesis of platelet-activating factor in glandular gastric mucosa. Evidence for the involvement of the 'de novo' pathway and modulation by fatty acids.

    PubMed

    Fernandez-Gallardo, S; Gijon, M A; Garcia, M C; Cano, E; Sanchez Crespo, M

    1988-09-15

    The biosynthesis of platelet-activating factor (PAF), a phospholipid autocoid with potent ulcerogenic properties that is produced in secretory exocrine glands by physiological secretagogues, was assessed in microsomal preparations of glandular gastric mucosa. For this purpose, 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine (lyso-PAF):acetyl-CoA acetyltransferase (EC 2.3.1.67); the enzymes of the 'de novo' pathway: 1-O-alkyl-2-lyso-sn-glycero-3-phosphate (alkyl-lyso-GP):acetyl-CoA acetyltransferase and 1-O-alkyl-2-acetyl-sn-glycerol (alkylacetyl-G):CDP-choline cholinephosphotransferase (EC 2.7.8.16); and some enzymes involved in the catabolism of PAF and lyso-PAF were assayed. Only the enzymes of the 'de novo' pathway and small amounts of PAF acetylhydrolase, phospholipase A2 and a lysophospholipase D acting on either lipids could be detected in the gastric preparations, whereas lyso-PAF:acetyl-CoA acetyltransferase activity was undetectable. The specific activity of alkyl-lyso-GP:acetyl-CoA acetyltransferase in the gastric mucosa was about one-tenth of that found in spleen microsomes and its apparent Km for acetyl-CoA was 454 microM compared with 277 microM in spleen microsomes. Glandular mucosa homogenates contained preformed PAF at a concentration of 2.7 +/- 0.7 ng equivalents of PAF (hexadecyl)/mg of protein. When gastric microsomes were incubated with micromolar concentrations of fatty acids (arachidonic, palmitic and oleic) prior to the assay of dithiothreitol (DTT)-insensitive cholinephosphotransferase, a dose-dependent reduction in the formation of PAF was observed, arachidonic acid being the most potent inhibitor, followed by linoleic acid (only tested on spleen microsomes) and oleic acid. By contrast, 1,2-diolein and phosphatidylcholine (dipalmitoyl) showed no or little effect. These results indicate that glandular gastric mucosa can produce PAF through the 'de novo' pathway, and that fatty acids, especially unsaturated, can reduce that synthesis by

  12. Comparison of the response using ICR mice derived from three different sources to ethanol/hydrochloric acid-induced gastric injury.

    PubMed

    Song, Sung Hwa; Kim, Ji Eun; Go, Jun; Koh, Eun Kyoung; Sung, Ji Eun; Lee, Hyun Ah; Choi, Kyung Min; Kim, Hae Deun; Jung, Young Suk; Kim, Kil Soo; Hwang, Dae Youn

    2016-03-01

    Animal models for gastric ulcers produced by physical, pharmacological and surgical methods have been widely employed to evaluate therapeutic drugs and investigate the mechanism of action of this disease. ICR mice were selected to produce this model, even though several mice and rats have been widely used in studies of gastric ulcers. To compare the responses of ICR mice obtained from three different sources to gastric ulcer inducers, alterations in gastric injury, histopathological structure, and inflammation were measured in Korl:ICR (Korea NIFDS source), A:ICR (USA source) and B:ICR (Japan source) treated with three concentrations of ethanol (EtOH) (50, 70, and 90%) in 150 mM hydrochloric acid (HCl) solution. Firstly, the stomach lesion index gradually increased as the EtOH concentration increased in three ICR groups. Moreover, a significant increase in the level of mucosal injury, edema and the number of inflammatory cells was similarly detected in the EtOH/HCl treated group compared with the vehicle treated group in three ICR groups. Furthermore, the number of infiltrated mast cells and IL-1β expression were very similar in the ICR group derived from three different sources, although some differences in IL-1β expression were detected. Especially, the level of IL-1β mRNA in 50 and 90EtOH/HCl treated group was higher in Korl:ICR and A:ICR than B:ICR. Overall, the results of this study suggest that Korl:ICR, A:ICR and B:ICR derived from different sources have an overall similar response to gastric ulcer induced by EtOH/HCl administration, although there were some differences in the magnitude of their responses. PMID:27051443

  13. Comparison of the response using ICR mice derived from three different sources to ethanol/hydrochloric acid-induced gastric injury

    PubMed Central

    Song, Sung Hwa; Kim, Ji Eun; Go, Jun; Koh, Eun Kyoung; Sung, Ji Eun; Lee, Hyun Ah; Choi, Kyung Min; Kim, Hae Deun; Jung, Young Suk; Kim, Kil Soo

    2016-01-01

    Animal models for gastric ulcers produced by physical, pharmacological and surgical methods have been widely employed to evaluate therapeutic drugs and investigate the mechanism of action of this disease. ICR mice were selected to produce this model, even though several mice and rats have been widely used in studies of gastric ulcers. To compare the responses of ICR mice obtained from three different sources to gastric ulcer inducers, alterations in gastric injury, histopathological structure, and inflammation were measured in Korl:ICR (Korea NIFDS source), A:ICR (USA source) and B:ICR (Japan source) treated with three concentrations of ethanol (EtOH) (50, 70, and 90%) in 150 mM hydrochloric acid (HCl) solution. Firstly, the stomach lesion index gradually increased as the EtOH concentration increased in three ICR groups. Moreover, a significant increase in the level of mucosal injury, edema and the number of inflammatory cells was similarly detected in the EtOH/HCl treated group compared with the vehicle treated group in three ICR groups. Furthermore, the number of infiltrated mast cells and IL-1β expression were very similar in the ICR group derived from three different sources, although some differences in IL-1β expression were detected. Especially, the level of IL-1β mRNA in 50 and 90EtOH/HCl treated group was higher in Korl:ICR and A:ICR than B:ICR. Overall, the results of this study suggest that Korl:ICR, A:ICR and B:ICR derived from different sources have an overall similar response to gastric ulcer induced by EtOH/HCl administration, although there were some differences in the magnitude of their responses. PMID:27051443

  14. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments

    NASA Astrophysics Data System (ADS)

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.

  15. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments.

    PubMed

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids. PMID:25796392

  16. Alteration of amino acids and related compounds in space environments

    NASA Astrophysics Data System (ADS)

    Kobayashi, K.; Tsuboi, T.; Kaneko, T.; Takano, Y.; Hashimoto, H.; Haruyama, J.; Yamashita, M.

    Organic compounds have been found in carbonaceous chondrites and in comets, which were possible materials for the first life on the Earth. It is suggested that these organics were originally formed in ice mantles of interstellar dusts (ISD) in molecular cloud. A number of studies were done to simulate reactions in ISD: Formation of amino acid precursors was reported when simulated interstellar media was irradiated with protons [1] or UV [2]. Extraterrestrial amino acids or their precursors in interstellar space, comets or meteorites were exposed to cosmic rays and UV before they were delivered to planets. Here we investigated stability of amino acids and related compounds in interstellar, lunar and planetary environments. Target compounds are (i) free amino acids, (ii) human serum albumin (HSA) and (iii) "possible interstellar complex organics (PICO)", which were formed from a mixture of carbon monoxide, ammonia and water by proton irradiation. Aqueous solutions of the target compounds were irradiated with gamma rays at room temperature, and they were acid-hydrolyzed before amino acid analysis. Recovery ratio of amino acids in HSA and PICO was much more than that of free amino acids. Samples mixed with basalt powder were more stable than those without the regolith. When the targets were irradiated after freeze-dried, their decomposition was not observed up to 30 kGy dosage. The present results show that extraterrestrial amino acids are quite stable if they are present as complex precursors in mineral matrix. Organic compounds in ISD are exposed not only to cosmic rays but also UV photons. It would be of interest to test stability of organic compounds in actual space environments: The exposure facility of International Space Station would be the place where the target molecules can be irradiated with cosmic rays and solar UV (including extreme UV) at the same time. [1] Kobayashi et al., Adv. Space Res., 16, 21 (1995), Kasamatsu et al., Bull. Chem. Soc. Jpn., 70

  17. The dual induction of apoptosis and autophagy by SZC014, a synthetic oleanolic acid derivative, in gastric cancer cells via NF-κB pathway.

    PubMed

    Rui, Li Xiao; Shu, Song Yu; Jun, Wu Jing; Mo, Chen Zi; Wu, Sun Zheng; Min, Liu Shu; Yuan, Lin; Yong, Peng Jin; Cheng, Song Zhi; Sheng, Wang Shi; Yao, Tang Ze

    2016-04-01

    Oleanolic acid (OA) possesses various pharmacological activities, such as antitumor and anti-inflammation; however, its clinical applications are limited by its relatively weak activities and low bioavailability. In this study, we evaluated the cytotoxic activity of seven novel OA derivatives, one of which, SZC014 [2-(pyrrolidine-1-yl) methyl-3-oxo-olean-12-en-28-oic acid], exhibited the strongest antitumor activity; its anticancer effect on gastric cancer cells and action mechanisms were investigated. The viability of OA and seven synthesized derivatives treating gastric cancer cells was detected using tetrazolium (MTT). Among them, SZC014 exhibited the strongest cytotoxic activity against gastric cancer cells (SGC7901, MGC803, and MKN-45). The effect of SZC014 on cell cycle was identified by propidium iodide (PI) staining assay. The cellular apoptosis induced by SZC014 was tested by annexin V/PI. The cellular morphological changes and ultrastructural structures affected by SZC014 were observed and imaged through inverted phase contrast microscope and transmission electron microscopy. Western blotting was performed to explore the expression of proteins associated with apoptosis (caspase 3, caspase 9, Bax, Bcl-2, and Bcl-xL), autophagy (Beclin 1 and ATG 5), and nuclear factor-κB (NF-κB) signal pathway, respectively. The cytotoxic activities of all the seven synthesized OA derivatives were stronger than that of OA against gastric cancer cells. SZC014 exhibited stronger cytotoxic activity than other OA derivatives, inhibited the proliferation of gastric cancer cells, besides, induced G2/M phase cell cycle arrest in SGC7901 cells. Both apoptosis and autophagy were found simultaneously in SZC014-treated SGC7901 cells. Caspase-dependent apoptosis induced by SZC014 was confirmed to be associated with upregulation of Bax and downregulation of Bcl-2 and Bcl-xL, while upregulation of Beclin 1 and ATG 5 was inferred to be involved in SZC014-induced autophagy. Moreover

  18. Exposure to Salt and Organic Acids Increases the Ability of Listeria monocytogenes To Invade Caco-2 Cells but Decreases Its Ability To Survive Gastric Stress†

    PubMed Central

    Garner, Matthew R.; James, Karen E.; Callahan, Michelle C.; Wiedmann, Martin; Boor, Kathryn J.

    2006-01-01

    The effects of environmental stress exposure on Listeria monocytogenes growth and virulence-associated characteristics were investigated. Specifically, we measured the effects of temperature (7 or 37°C), pH (5.5 or 7.4), the presence of salt and organic acids (375 mM NaCl, 8.45 mM sodium diacetate [SD], 275 mM sodium lactate [SL], or a combination of NaCl, SD, and SL), and deletion of sigB, which encodes a key stress response regulator, on the ability of L. monocytogenes to grow, invade Caco-2 cells, and survive exposure to synthetic gastric fluid (pH 2.5 or 4.5). Our results indicate that (i) L. monocytogenes log-phase generation times and maximum cell numbers are not dependent on the alternative sigma factor σB in the presence of NaCl and organic acids at concentrations typically found in foods; (ii) growth inhibition of L. monocytogenes through the addition of organic acids is pH dependent; (iii) the ability of L. monocytogenes to invade Caco-2 cells is affected by growth phase, temperature, and the presence of salt and organic acids, with the highest relative invasion capabilities observed for cells grown with SL or NaCl at 37°C and pH 7.4; (iv) growth of L. monocytogenes in the presence of NaCl, SD, or SL reduces its ability to survive exposure to gastric fluid; and (v) exposure of L. monocytogenes to gastric fluid reduces the enhanced invasiveness caused by growth in the presence of NaCl or SL. These findings suggest that virulence-associated characteristics that determine the L. monocytogenes infectious dose are likely to be affected by food-specific properties (e.g., pH or the presence of salt or organic acid). PMID:16885290

  19. Exposure to salt and organic acids increases the ability of Listeria monocytogenes to invade Caco-2 cells but decreases its ability to survive gastric stress.

    PubMed

    Garner, Matthew R; James, Karen E; Callahan, Michelle C; Wiedmann, Martin; Boor, Kathryn J

    2006-08-01

    The effects of environmental stress exposure on Listeria monocytogenes growth and virulence-associated characteristics were investigated. Specifically, we measured the effects of temperature (7 or 37 degrees C), pH (5.5 or 7.4), the presence of salt and organic acids (375 mM NaCl, 8.45 mM sodium diacetate [SD], 275 mM sodium lactate [SL], or a combination of NaCl, SD, and SL), and deletion of sigB, which encodes a key stress response regulator, on the ability of L. monocytogenes to grow, invade Caco-2 cells, and survive exposure to synthetic gastric fluid (pH 2.5 or 4.5). Our results indicate that (i) L. monocytogenes log-phase generation times and maximum cell numbers are not dependent on the alternative sigma factor sigmaB in the presence of NaCl and organic acids at concentrations typically found in foods; (ii) growth inhibition of L. monocytogenes through the addition of organic acids is pH dependent; (iii) the ability of L. monocytogenes to invade Caco-2 cells is affected by growth phase, temperature, and the presence of salt and organic acids, with the highest relative invasion capabilities observed for cells grown with SL or NaCl at 37 degrees C and pH 7.4; (iv) growth of L. monocytogenes in the presence of NaCl, SD, or SL reduces its ability to survive exposure to gastric fluid; and (v) exposure of L. monocytogenes to gastric fluid reduces the enhanced invasiveness caused by growth in the presence of NaCl or SL. These findings suggest that virulence-associated characteristics that determine the L. monocytogenes infectious dose are likely to be affected by food-specific properties (e.g., pH or the presence of salt or organic acid). PMID:16885290

  20. Acidic Digestion in a Teleost: Postprandial and Circadian Pattern of Gastric pH, Pepsin Activity, and Pepsinogen and Proton Pump mRNAs Expression

    PubMed Central

    Yúfera, Manuel; Moyano, Francisco J.; Astola, Antonio; Pousão-Ferreira, Pedro; Martínez-Rodríguez, Gonzalo

    2012-01-01

    Two different modes for regulation of stomach acid secretion have been described in vertebrates. Some species exhibit a continuous acid secretion maintaining a low gastric pH during fasting. Others, as some teleosts, maintain a neutral gastric pH during fasting while the hydrochloric acid is released only after the ingestion of a meal. Those different patterns seem to be closely related to specific feeding habits. However, our recent observations suggest that this acidification pattern could be modified by changes in daily feeding frequency and time schedule. The aim of this study was to advance in understanding the regulation mechanisms of stomach digestion and pattern of acid secretion in teleost fish. We have examined the postprandial pattern of gastric pH, pepsin activity, and mRNA expression for pepsinogen and proton pump in white seabream juveniles maintained under a light/dark 12/12 hours cycle and receiving only one morning meal. The pepsin activity was analyzed according to the standard protocol buffering at pH 2 and using the actual pH measured in the stomach. The results show how the enzyme precursor is permanently available while the hydrochloric acid, which activates the zymogen fraction, is secreted just after the ingestion of food. Results also reveal that analytical protocol at pH 2 notably overestimates true pepsin activity in fish stomach. The expression of the mRNA encoding pepsinogen and proton pump exhibited almost parallel patterns, with notable increases during the darkness period and sharp decreases just before the morning meal. These results indicate that white seabream uses the resting hours for recovering the mRNA stock that will be quickly used during the feeding process. Our data clearly shows that both daily illumination pattern and feeding time are involved at different level in the regulation of the secretion of digestive juices. PMID:22448266

  1. Gastric tissue biopsy and culture

    MedlinePlus

    ... laboratory test that examines the tissue sample for bacteria and other organisms that can cause disease. ... of organisms that cause infection. A gastric tissue culture may be ... Stomach acids normally prevent too much bacteria from growing.

  2. ACID GASES IN CO2-RICH SUBSURFACE GEOLOGIC ENVIRONMENTS

    SciTech Connect

    Chialvo, Ariel A; Vlcek, Lukas; Cole, David

    2013-01-01

    The analysis of species behavior involving dilute fluid environments has been crucial for the advance of modern solvation thermodynamics through molecular-based formalisms to guide the development of macroscopic regression tools in the description of fluid behavior and correlation of experimental data (Chialvo 2013). Dilute fluid environments involving geologic formations are of great theoretical and practical relevance regardless of the thermodynamic state conditions. The most challenging systems are those involving highly compressible and reactive confined environments, i.e., where small perturbations of pressure and/or temperature can trigger considerable density changes. This in turn can alter significantly the species solvation, their preferential solvation, and consequently, their reactivity with one another and with the surrounding mineral surfaces whose outcome is the modification of the substrate porosity and permeability, and ultimately, the integrity of the mineral substrates. Considering that changes in porosity and permeability resulting from dissolution and precipitation phenomena in confined environments are at the core of the aqueous CO2-mineral interactions, and that caprock integrity (e.g., sealing capacity) depends on these key parameters, it is imperative to gain fundamental understanding of the mineral-fluid interfacial phenomena and fluid-fluid equilibria under mineral confinement at subsurface conditions. In order to undertand the potential effects of acid gases as contaminants of supercritical CO2 streams, in the next section we will discuss the thermodynamic behavior of CO2 fluid systems by addressing two crucial issues in the context of carbon capture, utilization and sequestration (CCUS) technologies: (i) Why should we consider (acid gas) CO2 impurities? and (ii) Why are CO2 fluid - mineral interactions of paramount relevance?

  3. Evaluation of gastric toxicity of indomethacin acid, salt form and complexed forms with hydroxypropyl-beta-cyclodextrin on Wistar rats: histopathologic analysis.

    PubMed

    Ribeiro-Rama, A C; Figueiredo, Isabel Vitoria; Veiga, F; Castel-Branco, M M; Cabrita, A M S; Caramona, M M

    2009-12-01

    Indomethacin (IM) is a non-steroidal anti-inflammatory drug which inhibits prostaglandin biosynthesis. It is practically insoluble in water and has the capacity to induce gastric injury. Hydroxypropyl-beta-cyclodextrin (HP-beta-CD) is an alkylated derivative of beta-CD with the capacity to form inclusion complexes with suitable molecules. IM is considered to form partial inclusion complexes with HP-beta-CD by enclosure of the p-chlorobenzoic part of the molecule in the cyclodextrin channel, reducing the adverse effects. The aim of this paper is to evaluate the gastric damage induced by the IM inclusion complex prepared by freeze-drying and spray-drying. A total of 135 Wistar rats weighing 224.4 +/- 62.5 g were put into 10 groups. They were allowed free access to water but were maintained fasted for 18 h before the first administration until the end of the experiment. IM acid-form, IM trihydrated-sodium-salt and IM-HP-beta-CD spray and freeze-dried, at normal and toxic doses, were administered through gastric cannula once/day for 3 days. Seventy-two hours after the first administration, the animals were sacrificed and the stomachs collected and prepared for morphological study by using the haematoxylin-eosin technique. Lesion indexes (rated 0/4) were developed and the type of injury was scored according to the severity of damage and the incidence of microscopic evidence of harm. Microscopic assessment demonstrated levels of injury with index one on 10-25%. The type of complexation method had different incidence but the same degree. The results show that IM inclusion complexation protects against gastric injury, reducing the incidence and the maximum degree of severity from 4 to 1, with a better performance of the spray-dried complex. PMID:19656206

  4. Phase and Size Controllable Synthesis of NaYbF4 Nanocrystals in Oleic Acid/ Ionic Liquid Two-Phase System for Targeted Fluorescent Imaging of Gastric Cancer

    PubMed Central

    Pan, Liyuan; He, Meng; Ma, Jiebing; Tang, Wei; Gao, Guo; He, Rong; Su, Haichuan; Cui, Daxiang

    2013-01-01

    Upconversion nanocrystals with small size and strong fluorescent signals own great potential in applications such as biomolecule-labeling, in vivo tracking and molecular imaging. Herein we reported that NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals with small size and strong fluorescent signals were controllably synthesized by oleic acid (OA)/ ionic liquid (IL) two-phase system for targeted fluorescent imaging of gastric cancer in vivo. The optimal synthesis condition of NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals by OA/IL two-phase system was established, adding more metal ion such as Na+ ion could facilitate the size control and crystal-phase transition, more importantly, markedly enhancing fluorescent intensity of beta-phase nanocrystals compared with traditional methods. Alpha-phase NaYbF4, 2%Tm upconversion nanocrystals with less than 10nm in diameter and beta-phase NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals with 30 nm or so in diameter and strong fluorescent signals were obtained, these synthesized nanocrystals exhibited very low cytotoxicity. Folic acid-conjugated silica-modified beta-phase NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals were prepared, could actively target gastric cancer tissues implanted into nude mice in vivo, and realized targeted fluorescent imaging. Folic acid-conjugated silica-modified NaYbF4: 25%Gd, 2%Tm upconversion nanocrystals show great potential in applications such as targeted near infared radiation fluorescent imaging, magnetic resonance imaging and targeted therapy of gastric cancer in the near future. PMID:23471455

  5. Effect of peroxisome proliferator-activated receptor-alpha agonist (bezafibrate) on gastric secretion and gastric cytoprotection in rats.

    PubMed

    Pathak, Rahul; Asad, Mohammed; Hrishikeshavan, H Jagannath; Prasad, Satya

    2007-06-01

    The effect of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) on gastric secretion and gastric cytoprotection was evaluated using five different models of gastric ulcers: acetic acid-induced chronic gastric ulcers, pylorus ligation, ethanol-induced, indomethacin-induced and ischemia-reperfusion-induced gastric ulcers. Bezafibrate, a PPAR-alpha agonist was administered at two different doses of 10 and 100 mg/kg body weight intraperitoneanally. Both doses of bezafibrate showed significant antiulcer effect in ethanol-induced, indomethacin-induced and pylorus ligation-induced gastric ulcers. Bezafibrate increased healing of ulcer in acetic acid-induced chronic gastric ulcer model. Both doses were also effective in preventing gastric lesions induced by ischemia-reperfusion. It was concluded that PPAR-alpha activation increases healing of gastric ulcers and also prevents development of gastric ulcers in rats. PMID:17521298

  6. Exploring the potential of gastro retentive dosage form in delivery of ellagic acid and aloe vera gel powder for treatment of gastric ulcers.

    PubMed

    Ranade, Arati N; Ranpise, Nisharani S; Ramesh, C

    2014-01-01

    Approach of novel drug delivery system (NDDS) overcomes the limitations of conventional dosage forms. However, this concept is still not practiced to a large extent in delivery of herbal drugs in Ayurveda. Thus, the potential of herbal drugs has not been explored to its fullest. Hence, there is a growing need to amalgamate the concept of NDDS in delivery of herbal constituents. The present investigation is designed to deliver and retain two herbal constituents in stomach for better action against Helicobacter pylori induced gastric ulcers. The objective was to develop a bilayer floating tablet of ellagic acid and Aloe vera gel powder through rational combination of excipients to give the lowest possible lag time with maximum drug release in the period of 4 h. Formulation F9 containing 100 mg of HPMC K15M, 27 mg of crospovidone, 80 mg of mannitol and effervescent agents in the ratio 1:2 gave 92% drug release and desired floating properties. In vivo studies showed that combination of ellagic acid and Aloe vera gave 75 % ulcer inhibition in comparison to 57% ulcer inhibition in the group which was administered with ellagic acid alone. This suggests the use of bilayer floating tablet in gastric ulcer treatment. PMID:24261674

  7. Activity-guided fractionation to characterize a coffee beverage that effectively down-regulates mechanisms of gastric acid secretion as compared to regular coffee.

    PubMed

    Rubach, Malte; Lang, Roman; Skupin, Carola; Hofmann, Thomas; Somoza, Veronika

    2010-04-14

    In some individuals, the consumption of coffee beverages is related to symptoms of gastric irritation. Hot water steam-treatment of raw coffee beans is hypothesized to reduce the contents of stomach irritating compounds, and products to which this technology is applied are launched as stomach-friendly coffee. However, data on the effect of steam-treated coffee on gastric acid secretion are conflicting and it has not been proven yet as to which coffee components act as pro- or antisecretory stimulants. The work presented here aimed at the characterization of a coffee beverage that effectively down-regulates mechanisms of proton secretion in human gastric cells (HGT-1). At first, a regular coffee beverage was fractionated by using solvents of different polarity: water, ethylacetate, dichloromethane, and pentane. Functional assays on the proton secretory activity (PSA) of these solvent fractions revealed the least pronounced effect for the water fraction, for which quantitative analyses demonstrated the highest distribution of chlorogenic acid (95%), (beta)N-alkanoyl-5-hydroxytryptamides (55%), and N-methylpyridinium (N-MP, >99%) among all fractions. Following experiments demonstrated that HGT-1 cells treated with regular coffee fortified with N-MP at a concentration of about 20 mg/mL N-MP showed a significantly decreased PSA as compared to cells which were exposed to coffee beverages containing higher (32-34 mg/L) or lower (5 mg/L) N-MP concentrations. Results from cellular pathway analyses of transcription (ATF-1 and Akt1) and signaling (cAMP and EGFr) factors and kinases (ERK1/2), and experiments on the gene expression of pro (histamine-HRH2 and acetylcholine-CHRM3)- and anti (somatostatin-SSTR1)-secretory receptors and H(+),K(+)-ATPase verified this antisecretory activity of N-MP in coffee beverages. PMID:20235536

  8. Acidic pH changes receptor binding specificity of Helicobacter pylori: a binary adhesion model in which surface heat shock (stress) proteins mediate sulfatide recognition in gastric colonization.

    PubMed Central

    Huesca, M; Borgia, S; Hoffman, P; Lingwood, C A

    1996-01-01

    The gastric pathogen helicobacter pylori is one of a number of bacteria which bind specifically to gangliotetraosylceramide, gangliotriaosylceramide, and phosphatidylethanolamine in vitro at neutral pH. Since this organism encounters an acid pH during initial infection of the stomach, we have monitored the effect of pH on receptor binding specificity and found induction of specific binding to sulfoglycolipids (sulfatide) following brief treatment at low pH. We have previously shown that heat shock proteins (hsps) bind to sulfatide, and the suspicion that this was a stress-induced response is supported by the fact that a similar change in H. pylori binding specificity was observed if the organisms were briefly exposed to heat shock treatment. Following the stress stimulus, the change in glycolipid binding specificity was prevented by the inclusion of inhibitors of protein synthesis or by incubation with anti-hsp antibodies. Expression of hsps in the surface extract and surface reactivity with anti-hsp antibodies correlated with the change in glycolipid binding specificity. Despite the presence of high levels of H. pylori cell surface urease activity which may neutralize the microenvironmental pH, the acid-induced change in binding specificity was enhanced in the presence of urea. These studies suggest that cell surface hsps mediate sulfatide recognition by this organism under stress conditions. A binary receptor model is proposed for gastric colonization by H. pylori. PMID:8698490

  9. Chemical weathering of granite under acid rainfall environment, Korea

    NASA Astrophysics Data System (ADS)

    Lee, Seung Yeop; Kim, Soo Jin; Baik, Min Hoon

    2008-08-01

    Chemical weathering was investigated by collecting samples from five selected weathering profiles in a high elevation granitic environment located in Seoul, Korea. The overall changes of chemistry and mineralogical textures were examined reflecting weathering degrees of the samples, using polarization microscopy, X-ray diffraction (XRD), electron probe micro analysis (EPMA), X-ray fluorescence spectroscopy (XRF), and inductively coupled plasma-mass spectroscopy (ICP-MS). The chemical distribution in the weathering profiles shows that few trace elements are slightly immobile, whereas most major (particularly Ca and Na) and trace elements are mobile from the beginning of the granite weathering. On the other hand, there were mineralogical changes initiated from a plagioclase breakdown, which shows a characteristic circular dissolved pattern caused by a preferential leaching of Ca cation along grain boundaries and zoning. The biotite in that region is also supposed to be sensitive to exterior environmental condition and may be easily dissolved by acidic percolated water. As a result, it seems that some rock-forming minerals in the granitic rock located in Seoul are significantly unstable due to the environmental condition of acidic rainfall and steep slopes, where they are susceptible to be dissolved incongruently leading some elements to be highly depleted.

  10. The effects of acute and chronic administration of n-6 and n-3 polyunsaturated fatty acids on ethanol-induced gastric haemorrhage in rats.

    PubMed

    Hunter, B; McDonald, G S; Gibney, M J

    1992-05-01

    Female weanling rats in three equal groups (n 12) were given orally by intubation 1 ml micellar solution of taurocholic acid (10 mM) and either arachidonic acid (20:4 n-6), linoleic acid (18:2 n-6) or eicosapentaenoic acid (20:5 n-3) at a concentration of 120 mM. After 1 h the rats were given intragastrically 2 ml absolute ethanol and were killed 1 h later. Rats given oral 20:4 n-6 showed a significant reduction (P less than 0.05) in the extent (%) of gastric mucosal haemorrhage compared with either the rats given 20:5 n-3 or 18:2 n-6 (8.3 (SD 7.3), 23.2 (SD 10.4) and 21.4 (SD 10.4) respectively. In a second experiment, four equal groups (n 12) of female Wistar rats were fed for 5 weeks on either a control diet of standard laboratory rat food, or the same diet enriched with either maize oil or fish oil or butterfat at a level of 100 g/kg. Following a 24 h fast the rats received an intragastric dose of 2 ml ethanol and were killed 1 h later. Examination of the extent (%) of gastric lesion showed a significant reduction (P less than 0.05) with the feeding of either maize oil or fish oil compared with the controls (12.2 (SD 8.2), 15.3 (SD 13.2) and 29.3 (SD 14.0) respectively). The butterfat diet was not significantly different from the control diet (23.8 (SD 8.1)). PMID:1622986

  11. Gastric suction

    MedlinePlus

    ... al. Position paper update: gastric lavage for gastrointestinal decontamination. Clin Toxicol (Phila) . 2013;51(3); 140-146. ... 2012:chap 49. Zeringe M, Fowler GC. Gastrointesinal decontamination. In: Pfenninger JL, Fowler GC, eds. Pfenninger & Fowler's ...

  12. Gastric Banding

    MedlinePlus

    ... gastric banding before deciding to have the procedure. Advertisements for a device or procedure may not include ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  13. Gastric culture

    MedlinePlus

    ... test or procedure preparation (3 to 6 years) School age test or procedure preparation (6 to 12 ... immune system. The final results of the gastric culture test may take several weeks. Your provider will ...

  14. Paclitaxel plus valproic acid versus paclitaxel alone as second- or third-line therapy for advanced gastric cancer: a randomized Phase II trial

    PubMed Central

    Fushida, Sachio; Kinoshita, Jun; Kaji, Masahide; Oyama, Katsunobu; Hirono, Yasuo; Tsukada, Tomoya; Fujimura, Takashi; Ohta, Tetsuo

    2016-01-01

    Background Weekly paclitaxel (wPTX) is the preferred second-line chemotherapy for gastric cancer in Japan. Histone deacetylase inhibitors have been shown to decrease proliferation through cell-cycle arrest, differentiation, and apoptosis in gastric cancer cells. One histone deacetylase inhibitor, valproic acid (VPA), also inhibits tumor growth by inducing apoptosis and enhances the efficacy of paclitaxel (PTX), shown in a murine gastric cancer model. This Phase II trial was designed to evaluate the benefits of adding VPA to wPTX in patients with gastric cancer refractory to first-line treatment with fluoropyrimidine. Patients and methods The patients were randomly assigned in a 1:1 ratio to receive PTX 80 mg/m2 intravenously on days 1, 8, and 15, every 4 weeks, or a dose of PTX plus VPA taken everyday at 7.5 mg/kg twice daily. Random assignment was carried out at the data center with a minimization method adjusted by the Eastern Cooperative Oncology Group performance status (0–1 vs 2), prior chemotherapy (first-line vs second-line), and measurable lesions (presence vs absence). The primary end point was the overall survival (OS) rate, and the secondary end points were the progression-free survival rate and safety analysis. Results Sixty-six patients were randomly assigned to receive wPTX (n=33) or wPTX plus VPA (n=33). The median OS was 9.8 months in the wPTX group and 8.7 months in the wPTX plus VPA group (hazard ratio 1.19; 95% CI 0.702–2.026; P=0.51). The median progression-free survival was 4.5 months in the wPTX group and 3.0 months in the wPTX plus VPA group (hazard ratio 1.29; 95% CI 0.753–2.211; P=0.35). Grade 3–4 adverse events were neutropenia (3.1%), pneumonia (1.6%), liver injury (1.6%), brain infarction (1.6%), and rupture of aorta (1.6%). Conclusion No statistically significant difference was observed between wPTX and wPTX plus VPA for OS. PMID:27524882

  15. Canine gastric mucosal vasodilation with prostaglandins and histamine analogs

    SciTech Connect

    Gerber, J.G.; Nies, A.S.

    1982-10-01

    The effect of direct intragastric artery infusion of prostaglandins E2 and I2, arachidonic acid, dimaprit (histamine H2 agonist), and 2',2'-pyridylethylamine (histamine H1 agonist) on gastric mucosal blood flow was examined in dogs to elucidate the relationship between gastric secretory state and mucosal blood flow in dogs. These compounds were chosen because of their diverse effect on gastric acid secretion. Gastric fundus blood flow was measured both electromagnetically with a flow probe around the left gastric artery which supplies the fundus almost exclusively, and by the radioactive microsphere technique. Intraarterial infusion of all the compounds resulted in gastric mucosal vasodilation even though PGE2, PGI2, and arachidonic acid inhibit gastric acid secretion, dimaprit stimulated gastric acid secretion, and 2',2'-pyridylethylamine does not affect gastric acid secretion. There was total agreement in the blood flow measurements by the two different techniques. Our data suggest that gastric acid secretion and gastric vasodilation are independently regulated. In addition, the validity of the studies in which the aminopyrine clearance indicates that prostaglandins are mucosal vasoconstrictors needs to be questioned because of the reliance of those measurements on the secretory state of the stomach.

  16. Gastric Aspiration Models

    PubMed Central

    Davidson, Bruce A.; Alluri, Ravi

    2016-01-01

    The procedures described below are for producing gastric aspiration pneumonitis in mice with alterations for rats and rabbits described parenthetically. We use 4 different injury vehicles delivered intratracheally to investigate the inflammatory responses to gastric aspiration: Normal saline (NS) as the injury vehicle controlNS + HCl, pH = 1.25 (acid)NS + gastric particles, pH ≈ 5.3 (part.)NS + gastric particles + HCl, pH = 1.25 (acid + part.) The volume, pH, and gastric particle concentration all affect the resulting lung injury. In mice, we generally use an injury volume of 3.6 ml/kg (rat: 1.2 ml/kg, rabbit: 2.4 ml/kg), an injury pH (for the acid-containing vehicles) of 1.25, and a gastric particulate concentration (in the particulate-containing vehicles) of 10 mg/ml (rat: 40 mg/ml). In our hands this results in a maximal, non-lethal lung injury with ≤ 10% mortality for the most injurious vehicle (i.e., acid + part.) The maximum tolerable particulate concentration needs to be determined empirically for any new strains to be used, especially in genetically-altered mice, because an altered inflammatory response may have detrimental affects on mortality. We have extensive experience utilizing these procedures in the outbred strain, CD-1, as well as many genetically-altered inbred stains on the C57BL/6 background. Choice of strain should be carefully considered, especially in terms of strain-specific immune bias, to assure proper data interpretation. The size of the mouse should be ≥ 20 g at the time of injury. Smaller mice can be attempted, if necessary, but the surgical manipulation becomes increasingly more difficult and the surgery survival rate decreases substantially. There are no size or strain constraints for rat and rabbit models, but we generally use Long-Evans rats at 250–300 g and New Zealand White rats at ≈ 2 kg at the time of initial injury.

  17. THE ECOLOGICAL EFFECTS OF TRICHLORACETIC ACID (TCAA) IN THE ENVIRONMENT

    EPA Science Inventory

    Trichloroacetic acid (TCAA) is a member of the family of compounds known as chloroacetic acids, which includes mono-, di- and trichloroacetic acid. The significant property these compounds share is that they are all phytotoxic. TCAA once was widely used as a potent herbicide. ...

  18. Application of nanoparticles for oral delivery of acid-labile lansoprazole in the treatment of gastric ulcer: in vitro and in vivo evaluations

    PubMed Central

    Alai, Milind; Lin, Wen Jen

    2015-01-01

    The aim of this study was to develop nanoparticles for oral delivery of an acid-labile drug, lansoprazole (LPZ), for gastric ulcer therapy. LPZ-loaded positively charged Eudragit® RS100 nanoparticles (ERSNPs-LPZ) and negatively charged poly(lactic-co-glycolic acid) nanoparticles (PLGANPs-LPZ) were prepared. The effect of charge on nanoparticle deposition in ulcerated and non-ulcerated regions of the stomach was investigated. The cellular uptake of nanoparticles in the intestine was evaluated in a Caco-2 cell model. The pharmacokinetic performance and ulcer healing response of LPZ-loaded nanoparticles following oral administration were evaluated in Wistar rats with induced ulcers. The prepared drug-loaded ERSNPs-LPZ and PLGANPs-LPZ possessed opposite surface charge (+38.5±0.3 mV versus −27.3±0.3 mV, respectively) and the particle size was around 200 nm with a narrow size distribution. The negatively charged PLGANPs adhered more readily to the ulcerated region (7.22%±1.21% per cm2), whereas the positively charged ERSNPs preferentially distributed in the non-ulcerated region (8.29%±0.35% per cm2). Both ERSNPs and PLGANPs were prominent uptake in Caco-2 cells, too. The nanoparticles sustained and prolonged LPZ concentrations up to 24 hours, and the half-life and mean residence time of LPZ were prolonged by 3.5-fold and 4.5-fold, respectively, as compared with LPZ solution. Oral administration of LPZ-loaded nanoparticles healed 92.6%–95.7% of gastric ulcers in Wistar rats within 7 days. PMID:26124659

  19. Inhibition of Gastric Acid Secretion by H2 Receptor Antagonists Associates a Definite Risk of Enteric Peritonitis and Infectious Mortality in Patients Treated with Peritoneal Dialysis

    PubMed Central

    Pérez-Fontan, Miguel; Machado Lopes, Daniela; García Enríquez, Alba; López-Calviño, Beatriz; López-Muñiz, Andrés; García Falcón, Teresa; Rodríguez-Carmona, Ana

    2016-01-01

    Background Evidences linking treatment with inhibitors of gastric acid secretion (IGAS) and an increased risk of serious infections are inconclusive, both in the population at large and in the particular case of patients with chronic kidney disease. We have undertaken an investigation to disclose associations between treatment with IGAS and infectious outcomes, in patients undergoing chronic Peritoneal Dialysis (PD). Method Observational, historic cohort, single center design. Six hundred and ninety-one patients incident on PD were scrutinized for an association among treatment with IGAS (H2 antagonists H2A or proton pump inhibitors PPI) (main study variable), on one side, and the risks of enteric peritoneal infection (main outcome), overall peritoneal infection, and general and infectious mortality (secondary outcomes). We applied a three-step multivariate approach, based on classic Cox models (baseline variables), time-dependent analyses and, when appropriate, competing risk analyses. Main results The clinical characteristics of patients treated with H2A, PPI or none of these were significantly different. Multivariate analyses disclosed a consistently increased risk of enteric peritonitis in patients treated with IGAS (RR 1.65, 95% CI 1.08–2.55, p = 0.018, Cox). Stratified analysis indicated that patients treated with H2A, rather than those on PPI, supported the burden of this risk. Similar findings applied for the risk of infectious mortality. On the contrary, we were not able to detect any association among the study variables, on one side, and the general risks of peritonitis or mortality, on the other. Conclusions Treatment with IGAS associates increased incidences of enteric peritonitis and infectious mortality, among patients on chronic PD. The association is clear in the case of H2A but less consistent in the case of PPI. Our results support the convenience of preferring PPI to H2A, for gastric acid inhibition in PD patients. PMID:26872254

  20. New lactic acid bacterial strains from traditional Mongolian fermented milk products have altered adhesion to porcine gastric mucin depending on the carbon source.

    PubMed

    Kimoto-Nira, Hiromi; Yamasaki, Seishi; Sasaki, Keisuke; Moriya, Naoko; Takenaka, Akio; Suzuki, Chise

    2015-03-01

    Attachment of lactic acid bacteria to the mucosal surface of the gastrointestinal tract is a major property of probiotics. Here, we examined the ability of 21 lactic acid bacterial strains isolated from traditional fermented milk products in Mongolia to adhere to porcine gastric mucin in vitro. Higher attachment was observed with Lactobacillus delbrueckii subsp. bulgaricus strains 6-8 and 8-1 than with Lactobacillus rhamnosus GG (positive control). Lactococcus lactis subsp. cremoris strain 7-1 adhered to mucin as effectively as did strain GG. Heat inactivation decreased the adhesive ability of strains 6-8 and 8-1 but did not affect strain 7-1. The adhesion of strains 6-8, 7-1 and 8-1 was significantly inhibited when the cells were pretreated with periodate and trypsin, indicating that proteinaceous and carbohydrate-like cell surface compounds are involved in the adhesion of these strains. The adhesion of strain 7-1 was affected by the type of carbohydrate present in the growth medium, being higher with fructose than with lactose, galactose or xylose as the carbon source. The sugar content of 7-1 cells grown on various carbohydrates was negatively correlated with its adhesive ability. We provide new probiotic candidate strains and new information regarding carbohydrate preference that influences lactic acid bacterial adhesion to mucin. PMID:25186082

  1. Novel lansoprazole-loaded nanoparticles for the treatment of gastric acid secretion-related ulcers: in vitro and in vivo pharmacokinetic pharmacodynamic evaluation.

    PubMed

    Alai, Milind; Lin, Wen Jen

    2014-05-01

    The objective of this study is to combine nanoparticle design and enteric coating technique to sustain the delivery of an acid-labile drug, lansoprazole (LPZ), in the treatment of acid reflux disorders. Lansoprazole-loaded Eudragit® RS100 nanoparticles (ERSNP-LPZ) as well as poly(lactic-co-glycolic acid) (PLGA) nanoparticles (PLGANP-LPZ) were prepared using a solvent evaporation/extraction method. The effects of nanoparticle charge and permeation enhancers on lansoprazole uptake was assessed in Caco-2 cells. The confocal microscopic images revealed the successful localization of nanoparticles in the cytoplasm of Caco-2 cells. The cellular uptake of positively charged Eudragit nanoparticles was significantly higher than that of negatively charged PLGA nanoparticles, which were enhanced by sodium caprate via the transcellular pathway. Both types of nanoparticles exhibited sustained drug release behavior in vitro. The oral administration of enteric-coated capsules filled with nanoparticles sustained and prolonged the LPZ concentration up to 24 h in ulcer-induced Wistar rats, and 92.4% and 89.2% of gastric ulcers healed after a 7-day treatment with either EC-ERSNP1010-Na caprate or EC-PLGANP1005-Na caprate, respectively. PMID:24519468

  2. Corrosion studies in fuel element reprocessing environments containing nitric acid

    SciTech Connect

    Beavers, J A; White, R R; Berry, W E; Griess, J C

    1982-04-01

    Nitric acid is universally used in aqueous fuel element reprocessing plants; however, in the processing scheme being developed by the Consolidated Fuel Reprocessing Program, some of the equipment will be exposed to nitric acid under conditions not previously encountered in fuel element reprocessing plants. A previous report presented corrosion data obtained in hyperazeotropic nitric acid and in concentrated magnesium nitrate solutions used in its preparation. The results presented in this report are concerned with the following: (1) corrosion of titanium in nitric acid; (2) corrosion of nickel-base alloys in a nitric acid-hydrofluoric acid solution; (3) the formation of Cr(VI), which enhances corrosion, in nitric acid solutions; and (4) corrosion of mechanical pipe connectors in nitric acid. The results show that the corrosion rate of titanium increased with the refreshment rate of boiling nitric acid, but the effect diminished rapidly as the temperature decreased. The addition of iodic acid inhibited attack. Also, up to 200 ppM of fluoride in 70% HNO/sub 3/ had no major effect on the corrosion of either titanium or tantalum. In boiling 8 M HNO/sub 3/-0.05 M HF, Inconel 671 was more resistant than Inconel 690, but both alloys experienced end-grain attack. In the case of Inconel 671, heat treatment was very important; annealed and quenched material was much more resistant than furnace-cooled material.The rate of oxidation of Cr(III) to Cr(VI) increased significantly as the nitric acid concentration increased, and certain forms of ruthenium in the solution seemed to accelerate the rate of formation. Mechanical connectors of T-304L stainless steel experienced end-grain attack on the exposed pipe ends, and seal rings of both stainless steel and a titanium alloy (6% Al-4% V) underwent heavy attack in boiling 8 M HNO/sub 3/.

  3. Effect of centrally administered prolactin on gastric and duodenal ulcers in rats.

    PubMed

    Asad, M; Shewade, D G; Koumaravelou, K; Abraham, B K; Vasu, S; Ramaswamy, S

    2001-06-01

    The effect of centrally administered prolactin on gastric acid secretion and experimentally-induced gastric and duodenal ulcers was studied. The acute gastric ulcer models used were pylorus ligation, indomethacin-induced and ethanol-induced gastric ulcers. Chronic gastric ulcers were induced using acetic acid and duodenal ulcers by cysteamine hydrochloride. In pylorus ligated rats, prolactin (1 microg/kg icv) produced 45% increase in gastric content volume, significant increase in free acidity (P < 0.001), total acidity (P < 0.001) and ulcer index (P < 0.001). It did not show any significant effect on ethanol-induced and indomethacin-induced gastric ulcers. Prolactin increased the ulcer index (P < 0.001) and ulcer score (P < 0.05) in acetic acid-induced chronic gastric ulcers. It also increased ulcer area (P < 0.05) in cysteamine-induced duodenal ulcers. Therefore, the proulcerogenic activity of prolactin was due to its gastric hypersecretory effect. PMID:11468028

  4. pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices

    PubMed Central

    Zhang, Shiyi; Bellinger, Andrew M.; Glettig, Dean L.; Barman, Ross; Lee, Young-Ah Lucy; Zhu, Jiahua; Cleveland, Cody; Montgomery, Veronica A; Gu, Li; Nash, Landon D.; Maitland, Duncan J.; Langer, Robert; Traverso, Giovanni

    2015-01-01

    Devices resident in the stomach -- which are used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric retentive dosage forms for prolonged drug delivery -- typically incorporate elastic polymers to compress the devices during delivery through the esophagus and other narrow orifices in the digestive system. However, in the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. These enteric elastomers should increase the safety profile for a wide range of gastric retentive devices. PMID:26213897

  5. Effect of acid rain on the soil environment: a review

    SciTech Connect

    Rechcigl, J.E.; Sparks, D.L.

    1985-01-01

    This paper reviews the literature on acid rain, with emphasis on soils and leaching of soil elements. Several questions still exist concerning the effects of atmospheric acid deposition on soils: (1) does acid rain enhance mobilization of harmful heavy metals in soils which could leach into the groundwater; (2) does acid rain accelerate the kinetics of weathering of primary minerals and of secondary clay minerals in soils which would release large quantities of Al, Fe, and Si into the groundwater making it unfit for human consumption; and (3) do the beneficial effects of acid deposition outweigh the negative effects or vice versa. Literature pertaining to these questions is addressed in this review. 63 references.

  6. Capsaicin consumption, Helicobacter pylori CagA status and IL1B-31C>T genotypes: a host and environment interaction in gastric cancer.

    PubMed

    López-Carrillo, Lizbeth; Camargo, M Constanza; Schneider, Barbara G; Sicinschi, Liviu A; Hernández-Ramírez, Raúl U; Correa, Pelayo; Cebrian, Mariano E

    2012-06-01

    Gastric cancer (GC) has been associated with a complex combination of genetic and environmental factors. In contrast to most countries, available information on GC mortality trends showed a gradual increase in Mexico. Our aim was to explore potential interactions among dietary (chili pepper consumption), infectious (Helicobacter pylori) and genetic factors (IL1B-31 genotypes) on GC risk. The study was performed in three areas of Mexico, with different GC mortality rates. We included 158 GC patients and 317 clinical controls. Consumption of capsaicin (Cap), the pungent active substance of chili peppers, was estimated by food frequency questionnaire. H. pylori CagA status was assessed by ELISA, and IL1B-31 genotypes were determined by TaqMan assays and Pyrosequencing in DNA samples. Multivariate unconditional logistic regression was used to estimate potential interactions. Moderate to high Cap consumption synergistically increased GC risk in genetically susceptible individuals (IL1B-31C allele carriers) infected with the more virulent H. pylori (CagA+) strains. The combined presence of these factors might explain the absence of a decreasing trend for GC in Mexico. However, further research on gene-environment interactions is required to fully understand the factors determining GC patterns in susceptible populations, with the aim of recommending preventive measures for high risk individuals. PMID:22414649

  7. Capsaicin consumption, Helicobacter pylori CagA status and IL1B-31C > T genotypes: A host and environment interaction in gastric cancer

    PubMed Central

    López-Carrillo, Lizbeth; Camargo, M. Constanza; Schneider, Barbara G.; Sicinschi, Liviu A.; Hernández-Ramírez, Raúl U.; Correa, Pelayo; Cebrian, Mariano E.

    2013-01-01

    Gastric cancer (GC) has been associated with a complex combination of genetic and environmental factors. In contrast to most countries, available information on GC mortality trends showed a gradual increase in Mexico. Our aim was to explore potential interactions among dietary (chili pepper consumption), infectious (Helicobacter pylori) and genetic factors (IL1B-31 genotypes) on GC risk. The study was performed in three areas of Mexico, with different GC mortality rates. We included 158 GC patients and 317 clinical controls. Consumption of capsaicin (Cap), the pungent active substance of chili peppers, was estimated by food frequency questionnaire. H. pylori CagA status was assessed by ELISA, and IL1B-31 genotypes were determined by TaqMan assays and Pyrosequencing in DNA samples. Multivariate unconditional logistic regression was used to estimate potential interactions. Moderate to high Cap consumption synergistically increased GC risk in genetically susceptible individuals (IL1B-31C allele carriers) infected with the more virulent H. pylori (CagA+) strains. The combined presence of these factors might explain the absence of a decreasing trend for GC in Mexico. However, further research on gene–environment interactions is required to fully understand the factors determining GC patterns in susceptible populations, with the aim of recommending preventive measures for high risk individuals. PMID:22414649

  8. Activation of Muscarinic Acetylcholine Receptor Subtype 4 Is Essential for Cholinergic Stimulation of Gastric Acid Secretion: Relation to D Cell/Somatostatin

    PubMed Central

    Takeuchi, Koji; Endoh, Takuya; Hayashi, Shusaku; Aihara, Takeshi

    2016-01-01

    Background/Aim: Muscarinic acetylcholine receptors exist in five subtypes (M1∼M5), and they are widely expressed in various tissues to mediate diverse autonomic functions, including gastric secretion. In the present study, we demonstrated, using M1∼M5 KO mice, the importance of M4 receptors in carbachol (CCh) stimulation of acid secretion and investigated how the secretion is modulated by the activation of M4 receptors. Methods: C57BL/6J mice of wild-type (WT) and M1–M5 KO were used. Under urethane anesthesia, acid secretion was measured in the stomach equipped with an acute fistula. CCh (30 μg/kg) was given subcutaneously (s.c.) to stimulate acid secretion. Atropine or octreotide (a somatostatin analog) was given s.c. 20 min before the administration of CCh. CYN154806 (a somatostatin SST2 receptor antagonist) was given i.p. 20 min before the administration of octreotide or CCh. Results: CCh caused an increase of acid secretion in WT mice, and the effect was totally inhibited by prior administration of atropine. The effect of CCh was similarly observed in the animals lacking M1, M2 or M5 receptors but significantly decreased in M3 or M4 KO mice. CYN154806, the SST2 receptor antagonist, dose-dependently and significantly reversed the decreased acid response to CCh in M4 but not M3 KO mice. Octreotide, the somatostatin analog, inhibited the secretion of acid under CCh-stimulated conditions in WT mice. The immunohistochemical study showed the localization of M4 receptors on D cells in the stomach. Serum somatostatin levels in M4 KO mice were higher than WT mice under basal conditions, while those in WT mice were significantly decreased in response to CCh. Conclusions: These results suggest that under cholinergic stimulation the acid secretion is directly mediated by M3 receptors and indirectly modified by M4 receptors. It is assumed that the activation of M4 receptors inhibits the release of somatostatin from D cells and minimizes the acid inhibitory effect of

  9. Acid in the environment: lessons learned and future prospects

    SciTech Connect

    Visgilio, Gerald R.; Whitelaw, Diana M.

    2007-07-01

    This book is the result of a conference held biannually at the Goodwin-Niering Center for Conservation Biology and Environmental Studies at Connecticut College. It uses an interdisciplinary approach to focus on important ecological impacts of acid deposition, the transboundary nature of the pollutants that cause acid rain, and domestic and international policies designed to reduce the emission of these pollutants. The book combines research findings and the policy analyses of experts from different academic disciplines with the positions advanced by representatives of various nongovernmental organizations (NGOs). The sixteen papers are arranged in four parts entitled: ecological impacts of acid deposition; acid emissions energy and policy; sulfur dioxide and the market; and lessons learned and future prospects.

  10. A phase II study of paclitaxel, weekly, 24-hour continuous infusion 5-fluorouracil, folinic acid and cisplatin in patients with advanced gastric cancer

    PubMed Central

    Kollmannsberger, C; Quietzsch, D; Haag, C; Lingenfelser, T; Schroeder, M; Hartmann, J T; Baronius, W; Hempel, V; Clemens, M; Kanz, L; Bokemeyer, C

    2000-01-01

    To evaluate the toxicity and efficacy of combination chemotherapy with paclitaxel, cisplatin and 24 h continuous infusion of 5-FU/folinic acid in patients (pts) with unresectable, locally advanced or metastatic gastric adenocarcinoma. Forty-five chemotherapy-naive pts (28 male and 17 female) with a median age of 60 years (range 35–74) were enrolled. 5-FU 2 g/m2was given weekly over 24 h i.v. preceded by folinic acid 500 mg/m2as a 2 h infusion. Paclitaxel 175 mg/m2was administered as a 3 h-infusion on days 1 and 22 and cisplatin 50 mg/m2as 1 h infusion on days 8 and 29. Six weeks of therapy (days 1, 8, 15, 22, 29, 36) followed by 2 weeks rest were considered one cycle. A median of 3 cycles (range 1–4) were administered to 45 pts assessable for response, survival and toxicity. Five pts (11%) obtained a CR and 18 pts (40%) a PR (ORR 51%; 95% Cl: 35.8–66.3%). Responses were achieved in the liver, lymph nodes, lungs and at the site of the primary tumour. Nine pts (20%) had stable disease. Thirteen pts (29%) were considered to have failed treatment, 8 pts (18%) due to progressive disease and 5 pts (11%) who did not receive one complete cycle of therapy due to acute non-haematologic toxicity. The median progression-free and overall survival times were 9 months (range 1–36+) and 14 months (range 2–36+), respectively. Neutropenia WHO III°/IV° occurred in 7 pts (15%) with only 1 pt having grade IV. Additional non-haematologic WHO III°/IV° toxicities included nausea/vomiting in 5 (11%), alopecia in 22 (49%), and diarrhoea in 1 patient each (2%). Dose reductions or treatment delays were necessary in 8 pts (17%), mainly due to neutropenia. All pts were treated on an outpatient basis. The combination of paclitaxel, cisplatin and continuously infused 5-FU/folinic acid appears to be a highly active regimen for the treatment of pts with advanced gastric cancer. While the overall acceptable toxicity allows its use in the palliative setting, it may also be an attractive

  11. Acidic environments induce differentiation of Proteus mirabilis into swarmer morphotypes.

    PubMed

    Fujihara, Masatoshi; Obara, Hisato; Watanabe, Yusaku; Ono, Hisaya K; Sasaki, Jun; Goryo, Masanobu; Harasawa, Ryô

    2011-07-01

    Although swarmer morphotypes of Proteus mirabilis have long been considered to result from surfaced-induced differentiation, the present findings show that, in broth medium containing urea, acidic conditions transform some swimmer cells into elongated swarmer cells. This study has also demonstrates that P. mirabilis cells grown in acidic broth medium containing urea enhance virulence factors such as flagella production and cytotoxicity to human bladder carcinoma cell line T24, though no significant difference in urease activity under different pH conditions was found. Since there is little published data on the behavior of P. mirabilis at various hydrogen-ion concentrations, the present study may clarify aspects of cellular differentiation of P. mirabilis in patients at risk of struvite formation due to infection with urease-producing bacteria, as well as in some animals with acidic or alkaline urine. PMID:21707738

  12. Gastric Carcinoids

    PubMed Central

    Borch, Kurt; Ahrén, Bo; Ahlman, Håkan; Falkmer, Sture; Granérus, Göran; Grimelius, Lars

    2005-01-01

    Objective: To analyze tumor biology and the outcome of differentiated treatment in relation to tumor subtype in patients with gastric carcinoid. Background: Gastric carcinoids may be subdivided into ECL cell carcinoids (type 1 associated with atrophic gastritis, type 2 associated with gastrinoma, type 3 without predisposing conditions) and miscellaneous types (type 4). The biologic behavior and prognosis vary considerably in relation to type. Methods: A total of 65 patients from 24 hospitals (51 type 1, 1 type 2, 4 type 3, and 9 type 4) were included. Management recommendations were issued for newly diagnosed cases, that is, endoscopic or surgical treatment of type 1 and 2 carcinoids (including antrectomy to abolish hypergastrinemia) and radical resection for type 3 and 4 carcinoids. Results: Infiltration beyond the submucosa occurred in 9 of 51 type 1, 4 of 4 type 3, and 7 of 9 type 4 carcinoids. Metastases occurred in 4 of 51 type 1 (3 regional lymph nodes, 1 liver), the single type 2 (regional lymph nodes), 3 of 4 type 3 (all liver), and 7 of 9 type 4 carcinoids (all liver). Of the patients with type 1 carcinoid, 3 had no specific treatment, 40 were treated with endoscopic or surgical excision (in 10 cases combined with antrectomy), 7 underwent total gastrectomy, and 1 underwent proximal gastric resection. Radical tumor removal was not possible in 2 of 4 patients with type 3 and 7 of 9 patients with type 4 carcinoid. Five- and 10-year crude survival rates were 96.1% and 73.9% for type 1 (not different from the general population), but only 33.3% and 22.2% for type 4 carcinoids. Conclusion: Subtyping of gastric carcinoids is helpful in the prediction of malignant potential and long-term survival and is a guide to management. Long-term survival did not differ from that of the general population regarding type 1 carcinoids but was poor regarding type 4 carcinoids. PMID:15973103

  13. Eukaryotic Organisms in Extreme Acidic Environments, the Río Tinto Case

    NASA Astrophysics Data System (ADS)

    Angeles Aguilera, Angeles

    2013-07-01

    A major issue in microbial ecology is to identify the limits of life for growth and survival, and to understand the molecular mechanisms that define these limits. Thus, interest in the biodiversity and ecology of extreme environments has grown in recent years for several reasons. Some are basic and revolve around the idea that extreme environments are believed to reflect early Earth conditions. Others are related to the biotechnological potential of extremophiles. In this regard, the study of extremely acidic environments has become increasingly important since environmental acidity is often caused by microbial activity. Highly acidic environments are relatively scarce worldwide and are generally associated with volcanic activity or mining operations. For most acidic environments, low pH facilitates metal solubility, and therefore acidic waters tend to have high concentrations of heavy metals. However, highly acidic environments are usually inhabited by acidophilic and acidotolerant eukaryotic microorganisms such as algae, amoebas, ciliates, heliozoan and rotifers, not to mention filamentous fungi and yeasts. Here, we review the general trends concerning the diversity and ecophysiology of eukaryotic acidophilic microorganims, as well as summarize our latest results on this topic in one of the largest extreme acidic rivers, Río Tinto (SW, Spain).

  14. Potential probiotic lactic acid bacteria Lactobacillus rhamnosus (HN001), Lactobacillus acidophilus (HN017) and Bifidobacterium lactis (HN019) do not degrade gastric mucin in vitro.

    PubMed

    Zhou, J S; Gopal, P K; Gill, H S

    2001-01-22

    The mucus layer (mucin) coating the surface of the gastrointestinal tract (GIT) plays an important role in the mucosal barrier system. Any damage or disturbance of this mucin layer will compromise the host's mucosal defence function. In the present study, the ability of three potential probiotic lactic acid bacteria (LAB) strains (Lactobacillus rhamnosus HN001, Lactobacillus acidophilus HN017, Bifidobacterium lactis HN019) to degrade mucin in vitro was evaluated, in order to assess their potential pathogenicity and local toxicity. The LAB strains were incubated in medium containing hog gastric mucin (HGM, 0.3%) at 37 degrees C for 48 h, following which any decrease in carbohydrate and protein concentration in the ethanol-precipitated portion of the culture medium was determined, using phenol-sulphuric acid and bicinchonic acid (BCA) protein assays, respectively. The change in molecular weight of mucin glycoproteins, following incubation with the test strains, was monitored by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). In order to expose any ability of the test strains to degrade mucin visually and more directly, the test strains were also cultured on agarose containing 0.3% HGM and incubated anaerobically for 72 h at 37 degrees C. No significant change in the carbohydrate or protein concentration in mucin substrates was found following incubation with the test strains. No mucin fragments were derived from the mucin suspension incubated with test strains, and no mucinolysis zone was identified on agarose. These results demonstrate that the potential probiotic LAB strains tested here were unable to degrade gastrointestinal mucin in vitro, which suggests that these novel probiotic candidates are likely to be non-invasive and non-toxic at the mucosal interface. PMID:11205957

  15. Endoscopic evaluation of the comparative effects of acetylsalicylic acid and choline magnesium trisalicylate on human gastric and duodenal mucosa.

    PubMed

    Kilander, A; Dotevall, G

    1983-02-01

    A new salicylate product, choline magnesium trisalicylate (Trilisate tablets), and acetylsalicylic acid were compared for their local effects in equipotent doses on the gastroduodenal mucosa in a randomized, double-blind, cross-over study, using 10 healthy volunteers. After five-day periods of administration, gastroduodenoscopy was performed and photographs were obtained. All subjects given acetylsalicylic acid developed multiple mucosal lesions, but in only four subjects given choline magnesium trisalicylate were slight mucosal changes noted. Mean serum salicylate levels were similar in the two groups. Our data suggest that the risk of developing mucosal lesions is much less during treatment with choline magnesium trisalicylate than with acetylsalicylic acid. PMID:6337663

  16. Gastric infarction following gastric bypass surgery

    PubMed Central

    Do, Patrick H; Kang, Young S; Cahill, Peter

    2016-01-01

    Gastric infarction is an extremely rare occurrence owing to the stomach’s extensive vascular supply. We report an unusual case of gastric infarction following gastric bypass surgery. We describe the imaging findings and discuss possible causes of this condition. PMID:27200168

  17. Genotype x environment interactions in eggplant for fruit phenolic acid content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eggplant fruit are a rich source of phenolic acids that contribute to fruit nutritive value and influence culinary quality. We evaluated the influence of production environment on eggplant fruit phenolic acid content. Ten Solanum melongena accessions including five F1 hybrid cultivars, three open-...

  18. Acidic Alteration Environments on Mars and Implications for Habitability

    NASA Astrophysics Data System (ADS)

    Bishop, J. L.; Flahaut, J.; Weitz, C. M.; Gross, C.; Parente, M.; Horgan, B. H. N.

    2014-12-01

    Unique surface materials have been discovered recently at Valles Marineris (Roach et al., 2010; Weitz et al., 2014; Flahaut et al., 2014), Noctis Labyrinthus (Weitz et al., 2011), Mawrth Vallis (Bishop et al., 2013), and elsewhere that have CRISM features distinct from those of any known minerals. Typically these unusual sites are found in light-toned outcrops or interior layered deposits associated with phyllosilicates, sulfates or both. Frequently these units are called "doublet" materials because they exhibit a doublet absorption in CRISM spectra between 2.2 and 2.3 µm. We are investigating the spectral signatures of these martian materials compared to our library of minerals and alteration materials. We are also evaluating the stratigraphy of these unique alteration phases compared with neighboring phyllosilicate and sulfate units. A similar 2.2-2.3 µm doublet has been observed in spectra taken of acid altered clays produced in the laboratory (Madejova et al., 2009; Tosca et al., 2009). The band centers and relative intensities of these martian doublet features vary greatly suggesting that a process such as acid weathering could be acting on OH-bearing minerals to produce altered phases that differ depending on the type of substrate, water/rock ratio, solution chemistry, and duration of aqueous processes. Because these unique materials occur in many regions across a range of times on Mars, acidic alteration may have been a key process at local and regional scales throughout martian geologic history. Constraining the types of acidic alteration that have taken place on Mars will assist in defining the aqueous geochemistry at these sites and whether habitable conditions were possible. References: Bishop et al. (2013) PSS, 86, 130-149. Flahaut et al. (2014) EPSC, #211. Madejová et al. (2009) Vibrational Spectroscopy, 49, 211-218. Roach et al. (2010) Icarus, 206, 253-268. Tosca & Knoll (2009) 40th LPSC, #1538. Weitz et al. (2011) Geology, 39, 899-902. Weitz et al

  19. Delivery of ursolic acid (UA) in polymeric nanoparticles effectively promotes the apoptosis of gastric cancer cells through enhanced inhibition of cyclooxygenase 2 (COX-2).

    PubMed

    Zhang, Hao; Li, Xiaolin; Ding, Jing; Xu, Huae; Dai, Xinzheng; Hou, Zhibo; Zhang, Kai; Sun, Kun; Sun, Weihao

    2013-01-30

    It has been demonstrated that ursolic acid (UA) could effectively induces apoptosis of cancer cells by inhibiting the expression of cyclooxygenase 2 (COX-2), which constitutively expresses in gastric cancer. However, the hydrophobicity of UA increases the difficulty in its potential clinical application, which raises the possibility for its application as a novel model drug in nanoparticle-based delivery system. UA-loaded nanoparticles (UA-NPs) were prepared by a nano-precipitation method using amphilic methoxy poly(ethylene glycol)-polycaprolactone (mPEG-PCL) block copolymers as drug carriers. UA was effectively transported into SGC7901 cells by nanoparticles and localized around the nuclei in the cytoplasms. The in vitro cytotoxicity and apoptosis test indicated that UA-NPs significantly elicited more cell death at almost equivalent dose and corresponding incubation time. Moreover, UA-NPs led to more cell apoptosis through stronger inhibition of COX-2 and activation of caspase 3. The most powerful evidence from this report is that the significant differences between the cytotoxicity of free UA and UA-NPs are closely related to the expression levels of COX-2 and caspase-3, which demonstrates the superiority of UA-NPs over free UA through penetrating cell membrane. Therefore, the study offer an effective way to improve the anticancer efficiency of UA through nano-drug delivery system. PMID:23194884

  20. Temporal changes in bile acid levels and 12α-hydroxylation after Roux-en-Y gastric bypass surgery in type 2 diabetes

    PubMed Central

    Dutia, R; Embrey, M; O’Brien, S; Haeusler, RA; Agénor, KK; Homel, P; McGinty, J; Vincent, RP; Alaghband-Zadeh, J; Staels, B; le Roux, CW; Yu, J; Laferrère, B

    2015-01-01

    INTRODUCTION Gastric bypass surgery (GBP) leads to sustained weight loss and significant improvement in type 2 diabetes (T2DM). Bile acids (BAs), signaling molecules which influence glucose metabolism, are a potential mediator for the improvement in T2DM after GBP. This study sought to investigate the effect of GBP on BA levels and composition in individuals with T2DM. METHODS Plasma BA levels and composition and fibroblast growth factor (FGF)-19 levels were measured during fasting and in response to an oral glucose load before and at 1 month and 2 years post GBP in 13 severely obese women with T2DM. RESULTS A striking temporal change in BA levels and composition was observed after GBP. During the fasted state, BA concentrations were generally reduced at 1 month, but increased 2 years post GBP. Postprandial BA levels were unchanged 1 month post GBP, but an exaggerated postprandial peak was observed 2 years after the surgery. A significant increase in the 12α-hydroxylated/non12α-hydroxylated BA ratio during fasting and postprandially at 2 years, but not 1 month, post GBP was observed. Significant correlations between BAs vs FGF-19, body weight, the incretin effect and peptide YY (PYY) were also found. CONCLUSIONS This study provides evidence that GBP temporally modifies the concentration and composition of circulating BAs in individuals with T2DM, and suggests that BAs may be linked to the improvement in T2DM after GBP. PMID:25599611

  1. The dissolution behavior of scorodite in acidic environments

    NASA Astrophysics Data System (ADS)

    Pande, Preeti

    2001-11-01

    The safe disposal of arsenic-containing waste has been a difficult problem for the mining and metallurgical industry. One of the solutions to the arsenic problem is the precipitation of scorodite, an arsenic-containing mineral. Scorodite is reported to be relatively stable over a wide range of pH, and therefore may be a preferred disposal option. The effect of organic complexing agents on scorodite stability, however, is largely unknown. The present study is a phenomenological investigation into the dissolution kinetics of scorodite in the presence of oxalic acid under varying conditions of pH, oxalic acid concentration and temperature. The effect of scorodite particle size was also investigated. The morphological changes accompanying the dissolution process were examined by SEM and TEM analyses. Dissolution curves were divided into a linear induction period and a post-induction period. Activation energies were determined. Complete dissolution data were fit to the Prout-Tompkins/Austin-Rickett model. Dissolution data are indicative of auto-accelerated processes. The rapid increase in dissolution rate following the induction period is believed to be associated with an increase in the effective surface area. Pitting was observed on the surface of scorodite in the early stages of dissolution. In the later stages of dissolution, these pits were observed to grow and coalesce, in many cases resulting in the formation of dissolution holes.

  2. Bacteria and Archaea in acidic environments and a key to morphological identification

    USGS Publications Warehouse

    Robbins, E.I.

    2000-01-01

    Natural and anthropogenic acidic environments are dominated by bacteria and Archaea. As many as 86 genera or species have been identified or isolated from pH <4.5 environments. This paper reviews the worldwide literature and provide tables of morphological characteristics, habitat information and a key for light microscope identification for the non-microbiologist.

  3. Involvement of membrane-type bile acid receptor M-BAR/TGR5 in bile acid-induced activation of epidermal growth factor receptor and mitogen-activated protein kinases in gastric carcinoma cells

    SciTech Connect

    Yasuda, Hiroshi . E-mail: hiroshi-yasuda@showa-university-fujigaoka.gr.jp; Hirata, Shuko; Inoue, Kazuaki; Mashima, Hirosato; Ohnishi, Hirohide; Yoshiba, Makoto

    2007-03-02

    Bile acids, which have been implicated in gastrointestinal-tract cell carcinogenesis, share properties with tumor promoters in that both affect signal transduction pathways responsible for cell proliferation and apoptosis. In the present study, we demonstrate that EGFR-ERK1/2 is activated following treatment of AGS human gastric carcinoma cells with bile acids. EGFR phosphoactivation is ligand-dependent, since treatment of cells with HB-EGF antisera or CM197 (a selective inhibitor of HB-EGF) markedly inhibits deoxycholate (DC)-promoted activation. Membrane-type bile acid receptor (M-BAR)/TGR5 is a recently identified G-protein-coupled receptor (GPCR). In AGS cells, siRNAs that target M-BAR suppress DC-induced phosphorylation of EGFR. Furthermore, introduction of siRNAs targeting ADAM17 transcripts resulted in suppression of DC-induced activation of EGFR and ERK1/2. These results suggest that in AGS cells, DC transactivates EGFR through M-BAR- and ADAM/HB-EGF-dependent mechanisms.

  4. EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.

    USGS Publications Warehouse

    Mossotti, Victor G.; Lindsay, James R.; Hochella, Michael F., Jr.

    1987-01-01

    Salem limestone samples were exposed to weathering for 1 y in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone, whereas all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were not washed by precipitation. The gas-solid reaction of SO//2 with calcite was selected for detailed consideration. It appears from the model that under arid conditions, the quantity of stain deposited on an unwashed surface is independent of atmospheric SO//2 concentration once the surface has been saturated with gypsum. Under wet conditions, surface sulfation and weight loss are probably dominated by mechanisms involving wet stone. However, if the rain events are frequent and delimited by periods of dryness, the quantity of gypsum produced by a gas-solid reaction mechanism should correlate with both the frequency of rain events and the atmospheric SO//2 level.

  5. Helicobacter pylori, Cancer, and the Gastric Microbiota.

    PubMed

    Wroblewski, Lydia E; Peek, Richard M

    2016-01-01

    Gastric adenocarcinoma is one of the leading causes of cancer-related death worldwide and Helicobacter pylori infection is the strongest known risk factor for this disease. Although the stomach was once thought to be a sterile environment, it is now known to house many bacterial species leading to a complex interplay between H. pylori and other residents of the gastric microbiota. In addition to the role of H. pylori virulence factors, host genetic polymorphisms, and diet, it is now becoming clear that components of the gastrointestinal microbiota may also influence H. pylori-induced pathogenesis. In this chapter, we discuss emerging data regarding the gastric microbiota in humans and animal models and alterations that occur to the composition of the gastric microbiota in the presence of H. pylori infection that may augment the risk of developing gastric cancer. PMID:27573782

  6. Effects of toxic work environments on sperm quality and ascorbic acid levels

    SciTech Connect

    Dawson, E.B.; Harris, W.A.; Powell, L.C. )

    1990-02-26

    Surveys have shown that toxic work environments lower sperm quality, and controlled studies indicate that ascorbic acid supplementation improves sperm viability and agglutination. The sperm quality of 50 subjects each from: (1) office workers, (2) a lead smelter, (3) petroleum refineries, and (4) a herbicide plant were compared with serum and semen ascorbic acid levels. The sperm characteristics studied were: count as million/ml and as percent; viability, motility, clumping, and abnormal morphology. The serum ascorbic acid levels were directly proportional to sperm viability and inversely correlated to clumping of all groups. Moreover, serum ascorbic acid levels were also inversely correlated to twin tail and amorphous forms of abnormal sperm morphology. The results of the study indicate that toxic environments depress sperm quality and suggest that ascorbic acid supplementation will improve sperm quality and fertility.

  7. A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices

    NASA Astrophysics Data System (ADS)

    Zhang, Shiyi; Bellinger, Andrew M.; Glettig, Dean L.; Barman, Ross; Lee, Young-Ah Lucy; Zhu, Jiahua; Cleveland, Cody; Montgomery, Veronica A.; Gu, Li; Nash, Landon D.; Maitland, Duncan J.; Langer, Robert; Traverso, Giovanni

    2015-10-01

    Devices resident in the stomach--used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric-retentive dosage forms for prolonged drug delivery--typically incorporate elastic polymers to compress the devices during delivery through the oesophagus and other narrow orifices in the digestive system. However, in the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. These enteric elastomers should increase the safety profile for a wide range of gastric-retentive devices.

  8. A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices.

    PubMed

    Zhang, Shiyi; Bellinger, Andrew M; Glettig, Dean L; Barman, Ross; Lee, Young-Ah Lucy; Zhu, Jiahua; Cleveland, Cody; Montgomery, Veronica A; Gu, Li; Nash, Landon D; Maitland, Duncan J; Langer, Robert; Traverso, Giovanni

    2015-10-01

    Devices resident in the stomach-used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric-retentive dosage forms for prolonged drug delivery-typically incorporate elastic polymers to compress the devices during delivery through the oesophagus and other narrow orifices in the digestive system. However, in the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. These enteric elastomers should increase the safety profile for a wide range of gastric-retentive devices. PMID:26213897

  9. Environment and solute-solvent interaction effects on photo-physical behaviors of Folic acid and Folinic acid drugs

    NASA Astrophysics Data System (ADS)

    Khadem Sadigh, M.; Zakerhamidi, M. S.; Seyed Ahmadian, S. M.; Johari-Ahar, M.; Zare Haghighi, L.

    2016-12-01

    In this paper, spectral properties of Folic acid and Folinic acid as widely used drugs in the treatment of some diseases have been studied in various environments with different polarity. Our results show that the absorption, emission and stokes shifts of solute molecules depend strongly on molecular surrounding characteristics, solute-solvent interactions and, different active groups in their chemical structures. In order to investigate the contribution of specific and nonspecific interactions on various properties of drug samples, the linear solvation energy relationships concept is used. Moreover, the calculated dipole moments by means of solvatochromic method show that the high values of dipole moments in excited state are due to local intramolecular charge transfer. Furthermore, the obtained results about molecular interactions can be extended to biological systems and can indicate completely the behaviors of Folic acid and Folinic acid in polar solvents such as water in body system.

  10. Anti-metastasis effects of gallic acid on gastric cancer cells involves inhibition of NF-kappaB activity and downregulation of PI3K/AKT/small GTPase signals.

    PubMed

    Ho, Hsieh-Hsun; Chang, Chi-Sen; Ho, Wei-Chi; Liao, Sheng-You; Wu, Cheng-Hsun; Wang, Chau-Jong

    2010-01-01

    Polyphenols are natural antioxidants that are thought to contribute to prevention of cardiovascular disease and malignancy. Although many studies have been carried out to investigate the chemopreventive role of flavonoids, less attention has been focused on phenolic acids. In this study, the aim was to investigate the effect of phenolic acids found abundantly in vegetables, i.e. gallic acid (GA), caffeic acid (CA) and protocatechuic acid (PCA), on the inhibition of gastric adenocarcinoma (AGS) cell metastasis. The results showed 0.01 mM GA induced the same level of cell toxicity as 4.0mM PCA. Using wound-healing assay and Boyden chamber assay, GA had potent inhibitory effects on AGS cell migration. The expression of MMP-2/9 of AGS cells was inhibited by 2.0 microM of GA. It is possible that the suppressive effect of GA on MMP-2/9 might involve the inhibition of NF-kappaB activity. Multiple proteins involved in metastasis and the cytoskeletal reorganization signal pathway, including Ras, Cdc42, Rac1, RhoA, RhoB, PI3K and p38MAPK, were also inhibited by GA. Furthermore, immunoreactivity assay of cytoskeletal F-actin demonstrated a significant inhibitory effect of GA treatment. In conclusion, GA may have the potential to be an effective agent for prevention and treatment of gastric cancer metastasis. PMID:20600540

  11. Autotrophic, sulfur-oxidizing actinobacteria in acidic environments.

    PubMed

    Norris, Paul R; Davis-Belmar, Carol S; Brown, Carly F; Calvo-Bado, Leonides A

    2011-03-01

    Some novel actinobacteria from geothermal environments were shown to grow autotrophically with sulfur as an energy source. These bacteria have not been formally named and are referred to here as "Acidithiomicrobium" species, as the first of the acidophilic actinobacteria observed to grow on sulfur. They are related to Acidimicrobium ferrooxidans with which they share a capacity for ferrous iron oxidation. Ribulose bisphosphate carboxylase/oxygenase (RuBisCO) is active in CO(2) fixation by Acidimicrobium ferrooxidans, which appears to have acquired its RuBisCO-encoding genes from the proteobacterium Acidithiobacillus ferrooxidans or its ancestor. This lateral transfer of RuBisCO genes between a proteobacterium and an actinobacterium would add to those noted previously among proteobacteria, between proteobacteria and cyanobacteria and between proteobacteria and plastids. "Acidithiomicrobium" has RuBisCO-encoding genes which are most closely related to those of Acidimicrobium ferrooxidans and Acidithiobacillus ferrooxidans, and has additional RuBisCO genes of a different lineage. 16S rRNA gene sequences from "Acidithiomicrobium" species dominated clone banks of the genes extracted from mixed cultures of moderate thermophiles growing on copper sulfide and polymetallic sulfide ores in ore leaching columns. PMID:21308384

  12. Current status of proximal gastric vagotomy.

    PubMed Central

    Schirmer, B D

    1989-01-01

    Proximal gastric vagotomy is nearing its twentieth year in clinical use as an operation for peptic ulcer disease. No other acid-reducing operation has undergone as much scrutiny or study. At this time, the evidence of such studies and long-term follow-up strongly supports the use of proximal gastric vagotomy as the treatment of choice for chronic duodenal ulcer in patients who have failed medical therapy. Its application in treating the complications of peptic ulcer disease, which recently have come to represent an increasingly greater percentage of all operations done for peptic ulcer disease, is well-tested. However, initial series suggest that it should probably occupy a prominent role in treating some of these complications, particularly in selected patients, in the future. The operation has the well-documented ability to reduce gastric acid production, not inhibit gastric bicarbonate production, and also minimally inhibit gastric motility. The combination of these physiologic results after proximal gastric vagotomy, along with preservation of the normal antropyloroduodenal mechanism of gastrointestinal control, serve to allow patients with proximal gastric vagotomy the improved benefits of significantly fewer severe gastrointestinal side effects than are seen after other operations for peptic ulcer disease. PMID:2644897

  13. Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid

    PubMed Central

    Romo Vaquero, María; Yáñez-Gascón, María-Josefa; García Villalba, Rocío; Larrosa, Mar; Fromentin, Emilie; Ibarra, Alvin; Roller, Marc; Tomás-Barberán, Francisco; Espín de Gea, Juan Carlos; García-Conesa, María-Teresa

    2012-01-01

    Background Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. Methods and Principal Findings RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. Conclusions Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption. PMID:22745826

  14. Reversible inhibitions of gastric H+,K(+)-ATPase by scopadulcic acid B and diacetyl scopadol. New biochemical tools of H+,K(+)-ATPase.

    PubMed

    Asano, S; Mizutani, M; Hayashi, T; Morita, N; Takeguchi, N

    1990-12-25

    Scopadulcic acid B (SA-B), a novel diterpenoid, is a main ingredient of the Paraguayan traditional medicinal herb "Typychá kuratú (Scoparia dulcis L.). SA-B and its debenzoyl derivative, diacetyl scopadol (DAS), specifically inhibit ATP hydrolysis of gastric H+,K(+)-ATPase. Both compounds inhibit the K(+)-dependent dephosphorylation step of the enzyme without any effect on the phosphorylation step. SA-B is a mixed-type inhibitor with respect to the activating cation, K+. SA-B lowers the affinity of H+,K(+)-ATPase to K+ and decreases the maximal velocity of ATP hydrolysis, whereas DAS is an uncompetitive inhibitor with respect to K+. Furthermore, the effects of SA-B and DAS on conformational states of the ATPase were studied by measuring the changes in the fluorescence intensity of the fluorescein isothiocyanate-labeled enzyme. The fluorescence study shows that SA-B primarily binds to the E2K form in the presence of Mg2+ and stabilizes the form and that DAS stabilizes the E2PK form. Therefore, the chemical modification of SA-B, debenzoylation, induced the changes in the pattern of inhibition of H+,K(+)-ATPase. Furthermore, the inhibition mechanisms of SA-B and DAS were different from those of omeprazole, which is an irreversible inhibitor, and SCH 28080, which is a reversible, competitive inhibitor with respect to K+. DAS also inhibited the K(+)-dependent p-nitrophenyl phosphatase activity, and the inhibition was competitive with respect to K+, indicating that the K(+)-dependent p-nitrophenylphosphatase activity does not represent the partial reaction step of H+,K(+)-ATPase. PMID:2176205

  15. Anti-gastric ulcer effect of Kaempferia parviflora.

    PubMed

    Rujjanawate, C; Kanjanapothi, D; Amornlerdpison, D; Pojanagaroon, S

    2005-10-31

    Kaempferia parviflora is a Zingiberaceous plant, which has been reputed for its beneficial medicinal effects. The present study was undertaken to evaluate the Kaempferia parviflora ethanolic extract (KPE) for its anti-gastric ulcer activity by experimental models. Oral administration of the KPE at 30, 60 and 120 mg/kg significantly inhibited gastric ulcer formation induced by indomethacin, HCl/EtOH and water immersion restraint-stress in rats. In pylorus-ligated rats, pretreatment with the KPE had no effect on gastric volume, pH and acidity output. In ethanol-induced ulcerated rats, gastric wall mucus was significantly preserved by the KPE pretreatment at doses of 60 and 120 but not at 30 mg/kg. The findings indicate that the ethanolic extract of Kaempferia parviflora possesses gastroprotective potential which is related partly to preservation of gastric mucus secretion and unrelated to the inhibition of gastric acid secretion. PMID:16023318

  16. Characterization of modified calcium-silicate cements exposed to acidic environment

    SciTech Connect

    Camilleri, Josette

    2011-01-15

    Portland cement which is used as a binder in concrete in the construction industry has been developed into a biomaterial. It is marketed as mineral trioxide aggregate and is used in dentistry. This material has been reported to be very biocompatible and thus its use has diversified. The extended use of this material has led to developments of newer versions with improved physical properties. The aim of this study was to evaluate the effect of acidic environments found in the oral cavity on fast setting calcium silicate cements with improved physical properties using a combination of techniques. Two fast setting calcium silicate cements (CSA and CFA) and two cement composites (CSAG and CFAG) were assessed by subjecting the materials to lactic acid/sodium lactate buffer gel for a period of 28 days. At weekly intervals the materials were viewed under the tandem scanning confocal microscope (TSM), and scanning electron microscope (SEM). The two prototype cements exhibited changes in their internal chemistry with no changes in surface characteristics. Since the changes observed were mostly sub-surface evaluation of surface characteristics of cement may not be sufficient in the determination of chemical changes occurring. - Research Highlights: {yields} An acidic environment affects modified fast setting calcium silicate-based cements. {yields} No surface changes are observed in acidic environment. {yields} An acidic environment causes sub-surface changes in the material chemistry which are only visible in fractured specimens. {yields} A combination of techniques is necessary in order to evaluate the chemical changes occurring.

  17. Acid environments affect biofilm formation and gene expression in isolates of Salmonella enterica Typhimurium DT104.

    PubMed

    O'Leary, Denis; McCabe, Evonne M; McCusker, Matthew P; Martins, Marta; Fanning, Séamus; Duffy, Geraldine

    2015-08-01

    The aim of this study was to examine the survival and potential virulence of biofilm-forming Salmonella Typhimurium DT104 under mild acid conditions. Salmonella Typhimurium DT104 employs an acid tolerance response (ATR) allowing it to adapt to acidic environments. The threat that these acid adapted cells pose to food safety could be enhanced if they also produce biofilms in acidic conditions. The cells were acid-adapted by culturing them in 1% glucose and their ability to form biofilms on stainless steel and on the surface of Luria Bertani (LB) broth at pH7 and pH5 was examined. Plate counts were performed to examine cell survival. RNA was isolated from cells to examine changes in the expression of genes associated with virulence, invasion, biofilm formation and global gene regulation in response to acid stress. Of the 4 isolates that were examined only one (1481) that produced a rigid biofilm in LB broth at pH7 also formed this same structure at pH5. This indicated that the lactic acid severely impeded the biofilm producing capabilities of the other isolates examined under these conditions. Isolate 1481 also had higher expression of genes associated with virulence (hilA) and invasion (invA) with a 24.34-fold and 13.68-fold increase in relative gene expression respectively at pH5 compared to pH7. Although genes associated with biofilm formation had increased expression in response to acid stress for all the isolates this only resulted in the formation of a biofilm by isolate 1481. This suggests that in addition to the range of genes associated with biofilm production at neutral pH, there are genes whose protein products specifically aid in biofilm production in acidic environments. Furthermore, it highlights the potential for the use of lactic acid for the inhibition of Salmonella biofilms. PMID:25912312

  18. α-Lipoic Acid Inhibits Expression of IL-8 by Suppressing Activation of MAPK, Jak/Stat, and NF-κB in H. pylori-Infected Gastric Epithelial AGS Cells

    PubMed Central

    Choi, Ji Hyun; Cho, Soon Ok

    2016-01-01

    The epithelial cytokine response, associated with reactive oxygen species (ROS), is important in Helicobacter pylori (H. pylori)-induced inflammation. H. pylori induces the production of ROS, which may be involved in the activation of mitogen-activated protein kinases (MAPK), janus kinase/signal transducers and activators of transcription (Jak/Stat), and oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. α-lipoic acid, a naturally occurring thiol compound, is a potential antioxidant. It shows beneficial effects in treatment of oxidant-associated diseases including diabetes. The present study is purposed to investigate whether α-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-κB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without α-lipoic acid for 2 h and infected with H. pylori in a Korean isolate (HP99) at a ratio of 300:1. IL-8 mRNA expression was analyzed by RT-PCR analysis. IL-8 levels in the medium were determined by enzyme-linked immunosorbent assay. NF-κB-DNA binding activity was determined by electrophoretic mobility shift assay. Phospho-specific and total forms of MAPK and Jak/Stat were assessed by Western blot analysis. ROS levels were determined using dichlorofluorescein fluorescence. As a result, H. pylori induced increases in ROS levels, mRNA, and protein levels of IL-8, as well as the activation of MAPK [extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase 1/2 (JNK1/2), p38], Jak/Stat (Jak1/2, Stat3), and NF-κB in AGS cells, which was inhibited by α-lipoic acid. In conclusion, α-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation. PMID:26632410

  19. α-Lipoic Acid Inhibits Expression of IL-8 by Suppressing Activation of MAPK, Jak/Stat, and NF-κB in H. pylori-Infected Gastric Epithelial AGS Cells.

    PubMed

    Choi, Ji Hyun; Cho, Soon Ok; Kim, Hyeyoung

    2016-01-01

    The epithelial cytokine response, associated with reactive oxygen species (ROS), is important in Helicobacter pylori (H. pylori)-induced inflammation. H. pylori induces the production of ROS, which may be involved in the activation of mitogen-activated protein kinases (MAPK), janus kinase/signal transducers and activators of transcription (Jak/Stat), and oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. α-lipoic acid, a naturally occurring thiol compound, is a potential antioxidant. It shows beneficial effects in treatment of oxidant-associated diseases including diabetes. The present study is purposed to investigate whether α-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-κB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without α-lipoic acid for 2 h and infected with H. pylori in a Korean isolate (HP99) at a ratio of 300:1. IL-8 mRNA expression was analyzed by RT-PCR analysis. IL-8 levels in the medium were determined by enzyme-linked immunosorbent assay. NF-κB-DNA binding activity was determined by electrophoretic mobility shift assay. Phospho-specific and total forms of MAPK and Jak/Stat were assessed by Western blot analysis. ROS levels were determined using dichlorofluorescein fluorescence. As a result, H. pylori induced increases in ROS levels, mRNA, and protein levels of IL-8, as well as the activation of MAPK [extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase 1/2 (JNK1/2), p38], Jak/Stat (Jak1/2, Stat3), and NF-κB in AGS cells, which was inhibited by α-lipoic acid. In conclusion, α-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation. PMID:26632410

  20. Survival and expression of acid resistance genes in Shiga toxin-producing Escherichia coli acid adapted in pineapple juice and exposed to synthetic gastric fluid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: The aim of this research was to examine relative transcriptional expression of acid resistance (AR) genes, rpoS, gadA and adiA, in O157:H7 and non-O157 Shiga toxin-producing Escherichia coli (STEC) serotypes after adaptation to pineapple juice (PJ) and subsequently to determine survival with e...

  1. Influence of experimental hypokinesia on gastric secretory function

    NASA Technical Reports Server (NTRS)

    Markova, O. O.; Vavryshchuk, V. I.; Rozvodovskyy, V. I.; Proshcheruk, V. A.

    1980-01-01

    The gastric secretory function of rats was studied in 4, 8, 16 and 30 day hypokinesia. Inhibition of both the gastric juice secretory and acid producing functions was found. The greatest inhibition was observed on day 8 of limited mobility. By days 16 and 30 of the experiment, a tendency of the gastric secretory activity to return to normal was observed, although it remained reduced.

  2. Stomach (Gastric) Cancer Screening

    MedlinePlus

    ... Treatment Stomach Cancer Prevention Stomach Cancer Screening Research Stomach (Gastric) Cancer Screening (PDQ®)–Patient Version What is ... These are called diagnostic tests . General Information About Stomach (Gastric) Cancer Key Points Stomach cancer is a ...

  3. The Influence of a Collaborative Learning Environment on Primary Students' Conceptions about Acid Rain.

    ERIC Educational Resources Information Center

    Marinopoulos, Dimitrios; Stavridou, Heleni

    2002-01-01

    Investigates primary students' conceptions of acid rain formation and its consequences to people and the environment before and after a 10-hour constructivist teaching intervention. Reports improvement in conceptions of physical and chemical phenomena among the experimental group participants. (Contains 23 references.) (Author/YDS)

  4. Isolation and Characterization of Methanesulfonic Acid-Degrading Bacteria from the Marine Environment

    PubMed Central

    Thompson, A. S.; Owens, N.; Murrell, J. C.

    1995-01-01

    Two methylotrophic bacterial strains, TR3 and PSCH4, capable of growth on methanesulfonic acid as the sole carbon source were isolated from the marine environment. Methanesulfonic acid metabolism in these strains was initiated by an inducible NADH-dependent monooxygenase, which cleaved methanesulfonic acid into formaldehyde and sulfite. The presence of hydroxypyruvate reductase and the absence of ribulose monophosphate-dependent hexulose monophosphate synthase indicated the presence of the serine pathway for formaldehyde assimilation. Cell suspensions of bacteria grown on methanesulfonic acid completely oxidized methanesulfonic acid to carbon dioxide and sulfite with a methanesulfonic acid/oxygen stoichiometry of 1.0:2.0. Oxygen electrode-substrate studies indicated the dissimilation of formaldehyde to formate and carbon dioxide for energy generation. Carbon dioxide was not fixed by ribulose bisphosphate carboxylase. It was shown that methanol is not an intermediate in methanesulfonic acid metabolism, although these strains grew on methanol and other one-carbon compounds, as well as a variety of heterotrophic carbon sources. These two novel marine facultative methylotrophs have the ability to mineralize methanesulfonic acid and may play a role in the cycling of global organic sulfur. PMID:16535055

  5. Do calories or osmolality determine gastric emptying

    SciTech Connect

    Shafer, R.B.; Levine, A.S.; Marlette, J.M.; Morley, J.E.

    1984-01-01

    Recent animal studies suggest that gastric emptying is dependent on the caloric and osmotic content of the ingested food. These studies have involved intubation with infusion of liquid meals into the stomach. Scintigraphic methods, which are non-invasive and do not alter normal physiology, are now available for precise quantitation of gastric emptying. To study the role of calories and osmolality on gastric emptying, the authors employed a standardized /sup 99m/Tc-scrambled egg meal washed with 50 cc tap water in 10 normal human volunteers. A variety of simple and complex sugars, non-absorbable complex carbohydrate (polycose), medium chain fatty acid (MCFA) and gluten were dissolved in water and ingested with the test meal. Each subject acted as his own control. Coefficient of variation in control tests in each subject 12 weeks apart was 9.9%. Results showed that incremental glucose (25-66 gm) produced a linear increase in gastric emptying (T/2 control 50 +- 3, 25 gm 60 +- 3, 50 gm 79 +- 3 and 66 gm 102 +- 3 minutes). 25 gm fructose (T/2 59 +- 3 minutes) and 25 gm polycose (T/2 59 +- 3 minutes) had similar effects to glucose. 25 gm sucrose and 25 gm gluten did not significantly differ from controls. MCFA had an effect similar to 50 gm glucose - suggesting that calories are important in gastric emptying. However, 25 gm xylose markedly prolonged gastric emptying to 80 +- 5 minutes. The rank order for osmolality for substances tested MCFA = gluten < polycose < polycose < fructose < sucrose = glucose < xylose defined no relationship to gastric emptying. The authors' results suggest that neither calories nor osmolality alone determine gastric emptying. A specific food does not necessarily have the same effect on gastric emptying in different individuals.

  6. Effect of Acidic Environment on Dislocation Resistance of Endosequence Root Repair Material and Mineral Trioxide Aggregate

    PubMed Central

    Shokouhinejad, Noushin; Yazdi, Kazem Ashofteh; Nekoofar, Mohammad Hossein; Matmir, Shakiba; Khoshkhounejad, Mehrfam

    2014-01-01

    Objective: The aim of this study was to compare the effect of an acidic environment on dislocation resistance (push-out bond strength) of EndoSequence Root Repair Material (ERRM putty and ERRM paste), a new bioceramic-based material, to that of mineral tri-oxide aggregate (MTA). Materials and Methods: One-hundred twenty root dentin slices with standardized canal spaces were divided into 6 groups (n = 20 each) and filled with tooth-colored ProRoot MTA (groups 1 and 2), ERRM putty (groups 3 and 4), or ERRM paste (groups 5 and 6). The specimens of groups 1, 3, and 5 were exposed to phosphate buffered saline (PBS) solution (pH=7.4) and those of groups 2, 4, and 6 were exposed to butyric acid (pH= 4.4). The specimens were then incubated for 4 days at 37°C. The push-out bond strength was then measured using a universal testing machine. Failure modes after the push-out test were examined under a light microscope at ×40 magnification. The data for dislocation resistance were analyzed using the t-test and one-way analysis of variance. Results: In PBS environment (pH=7.4), there were no significant differences among materials (P=0.30); but the mean push-out bond strength of ERRM putty was significantly higher than that of other materials in an acidic environment (P<0.001). Push-out bond strength of MTA and ERRM paste decreased after exposure to an acidic environment; whereas ERRM putty was not affected by acidic pH. The bond failure mode was predominantly cohesive for all groups except for MTA in an acidic environment; which showed mixed bond failure in most of the specimens. Conclusion: The force needed for dislocation of MTA and ERRM paste was significantly lower in samples stored in acidic pH; however, push-out bond strength of ERRM putty was not influenced by acidity. PMID:24910691

  7. Synergistic anticancer properties of docosahexaenoic acid and 5-fluorouracil through interference with energy metabolism and cell cycle arrest in human gastric cancer cell line AGS cells

    PubMed Central

    Gao, Kun; Liang, Qi; Zhao, Zhi-Hao; Li, You-Fen; Wang, Shu-Feng

    2016-01-01

    AIM: To explore the synergistic effect of docosahexaenoic acid (DHA)/5-fluorouracil (5-FU) on the human gastric cancer cell line AGS and examine the underlying mechanism. METHODS: AGS cells were cultured and treated with a series of concentrations of DHA and 5-FU alone or in combination for 24 and 48 h. To investigate the synergistic effect of DHA and 5-FU on AGS cells, the inhibition of cell proliferation was determined by MTT assay and cell morphology. Flow cytometric analysis was also used to assess cell cycle distribution, and the expression of mitochondrial electron transfer chain complexes (METCs) I, II and V in AGS cells was further determined by Western blot analysis. RESULTS: DHA and 5-FU alone or in combination could markedly suppress the proliferation of AGS cells in a significant time and dose-dependent manner. DHA markedly strengthened the antiproliferative effect of 5-FU, decreasing the IC50 by 3.56-2.15-fold in an apparent synergy. The morphological changes of the cells were characterized by shrinkage, cell membrane blebbing and decreased adherence. Cell cycle analysis showed a shift of cells into the G0/G1 phase from the S phase following treatment with DHA or 5-FU (G0/G1 phase: 30.04% ± 1.54% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P < 0.05; S phase: 56.76% ± 3.14% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P < 0.05). Combination treatment of DHA and 5-FU resulted in a significantly larger shift toward the G0/G1 phase and subsequent reduction in S phase (G0/G1 phase: 69.06% ± 2.63% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P < 0.05; S phase: 19.80% ± 4.30% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P < 0.05). This synergy was also reflected in the significant downregulation of the expression of METCs in AGS cells. CONCLUSION: Synergistic anticancer properties of DHA and 5-FU may involve interference with energy production of AGS cells via downregulation of METCs and cell cycle arrest. PMID

  8. Investigation of secondary formation of formic acid: urban environment vs. oil and gas producing region

    NASA Astrophysics Data System (ADS)

    Yuan, B.; Veres, P. R.; Warneke, C.; Roberts, J. M.; Gilman, J. B.; Koss, A.; Edwards, P. M.; Graus, M.; Kuster, W. C.; Li, S.-M.; Wild, R. J.; Brown, S. S.; Dubé, W. P.; Lerner, B. M.; Williams, E. J.; Johnson, J. E.; Quinn, P. K.; Bates, T. S.; Lefer, B.; Hayes, P. L.; Jimenez, J. L.; Weber, R. J.; Zamora, R.; Ervens, B.; Millet, D. B.; Rappenglück, B.; de Gouw, J. A.

    2015-02-01

    Formic acid (HCOOH) is one of the most abundant carboxylic acids in the atmosphere. However, current photochemical models cannot fully explain observed concentrations and in particular secondary formation of formic acid across various environments. In this work, formic acid measurements made at an urban receptor site (Pasadena) in June-July 2010 during CalNex (California Research at the Nexus of Air Quality and Climate Change) and a site in an oil and gas producing region (Uintah Basin) in January-February 2013 during UBWOS 2013 (Uintah Basin Winter Ozone Studies) will be discussed. Although the VOC (volatile organic compounds) compositions differed dramatically at the two sites, measured formic acid concentrations were comparable: 2.3 ± 1.3 in UBWOS 2013 and 2.0 ± 1.0 ppb in CalNex. We determine that concentrations of formic acid at both sites were dominated by secondary formation (> 99%). A constrained box model using the Master Chemical Mechanism (MCM v3.2) underestimates the measured formic acid concentrations drastically at both sites (by a factor of > 10). Compared to the original MCM model that includes only ozonolysis of unsaturated organic compounds and OH oxidation of acetylene, when we updated yields of ozonolysis of alkenes and included OH oxidation of isoprene, vinyl alcohol chemistry, reaction of formaldehyde with HO2, oxidation of aromatics, and reaction of CH3O2 with OH, the model predictions for formic acid were improved by a factor of 6.4 in UBWOS 2013 and 4.5 in CalNex, respectively. A comparison of measured and modeled HCOOH/acetone ratios is used to evaluate the model performance for formic acid. We conclude that the modified chemical mechanism can explain 19 and 45% of secondary formation of formic acid in UBWOS 2013 and CalNex, respectively. The contributions from aqueous reactions in aerosol and heterogeneous reactions on aerosol surface to formic acid are estimated to be 0-6 and 0-5% in UBWOS 2013 and CalNex, respectively. We observe that

  9. Effect of centrally administered losartan on gastric and duodenal ulcers in rats.

    PubMed

    Merai, Ankitkumar Harshadrai; Asad, Mohammed; Prasad, V Satya

    2009-01-01

    The effect of centrally administered losartan, an AT(1) receptor antagonist, on gastric acid secretion and gastric cytoprotection was studied using different models of gastric ulcers, such as acetic acid-induced chronic gastric ulcers, pylorus ligation, ethanol-induced and stress-induced acute gastric ulcers and cysteamine hydrochloride-induced duodenal ulcer. Losartan was administered intracerebroventrically (i.c.v.) at 2 different doses (125 and 250 microg/kg). Both doses of losartan increased the healing of acetic acid-induced chronic gastric ulcers. In pylorus-ligated rats, a significant reduction in free acidity, total acidity and ulcer index was observed with high dose (250 microg/kg, i.c.v.), while low dose (125 microg/kg, i.c.v.) produced reduction only in free acidity and ulcer index. Both doses also produced a significant antiulcer effect in ethanol-induced and stress-induced gastric ulcers. Losartan also reduced ulcer area in cysteamine-induced duodenal ulcer. We conclude that AT(1) receptor antagonism in the brain increases healing of gastric ulcers and reduces gastric acid secretion and increases gastric mucin content. PMID:19602912

  10. Gastric emptying and Helicobacter pylori infection in duodenal ulcer disease.

    PubMed

    Perri, F; Ghoos, Y F; Maes, B D; Geypens, B J; Ectors, N; Geboes, K; Hiele, M I; Rutgeerts, P J

    1996-03-01

    The pathogenetic link between Helicobacter pylori gastritis and duodenal ulcer is still unknown. Fast gastric emptying of liquids might be important in the pathogenesis of gastric metaplasia of the duodenum and duodenal ulcer through an increased exposure of the duodenum to gastric acid. In H. pylori-infected subjects, an abnormal gastric emptying could affect urea breath test results and correlate with histological gastritis. This study was performed to evaluate the gastric emptying of liquids in duodenal ulcer patients with H. pylori infection and the possible relation between the bacterial load, gastric emptying, and urea breath test results. Seventeen duodenal ulcer patients with H. pylori gastritis and 15 healthy volunteers were studied by a [14C]octanoic acid and [13C]urea breath test to evaluate gastric emptying rate and H. pylori status simultaneously. Endoscopy with antral biopsies were performed in all duodenal ulcer patients. Duodenal ulcer patients with H. pylori infection have a normal liquid gastric emptying that is unrelated with histological severity of gastritis. The urea breath test results and the gastric emptying parameters do not correlate with histology. A significant correlation between the gastric emptying and the urea hydrolysis rate is found. It is concluded that H. pylori infection and duodenal ulcer disease is not associated with abnormally fast liquid gastric emptying, and this finding should be taken into account when a casual link between H. pylori infection and duodenal ulcer disease is searched for. The correlation between gastric emptying and urea hydrolysis rate explains why no conclusions on intragastric bacterial load can be drawn from the urea breath test results. PMID:8617116

  11. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... of the cells in the stomach to release acid. The stomach contents are then removed and analyzed. ... 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour in ...

  12. Basis of decreased risk of gastric cancer in severe atrophic gastritis with eradication of Helicobacter pylori.

    PubMed

    Tari, Akira; Kitadai, Yasuhiko; Sumii, Masaharu; Sasaki, Atsunori; Tani, Hiroshi; Tanaka, Sinji; Chayama, Kazuaki

    2007-01-01

    Helicobacter pylori infection induces chronic gastritis and lowers gastric juice ascorbic acid concentrations. We investigated how H. pylori eradication affected multiple variables that could prevent or delay development of new or occult gastric cancer in patients with early gastric cancer treated by endoscopic mucosal resection. Gastric juice pH, nitrite concentrations, and total vitamin C concentrations, serum concentrations of vitamin C and specific H. pylori antibody, and intensity of neutrophil infiltration in gastric mucosa were determined before and after successful H. pylori eradication. Successful eradication increased acid output and ascorbic acid secretion into gastric juice, accompanied by disappearance of polymorphonuclear infiltration from the surface epithelium and decreased gastric juice nitrite concentrations. Our data suggest that H. pylori eradication decreases the nitrosation rate as the ratio of vitamin C to nitrite increases. This decreases reactive oxygen species and nitric oxide, eliminating their damaging effect on DNA and reducing cell turnover. PMID:17151803

  13. History of Helicobacter pylori, duodenal ulcer, gastric ulcer and gastric cancer

    PubMed Central

    Graham, David Y

    2014-01-01

    Helicobacter pylori (H. pylori) infection underlies gastric ulcer disease, gastric cancer and duodenal ulcer disease. The disease expression reflects the pattern and extent of gastritis/gastric atrophy (i.e., duodenal ulcer with non-atrophic and gastric ulcer and gastric cancer with atrophic gastritis). Gastric and duodenal ulcers and gastric cancer have been known for thousands of years. Ulcers are generally non-fatal and until the 20th century were difficult to diagnose. However, the presence and pattern of gastritis in past civilizations can be deduced based on the diseases present. It has been suggested that gastric ulcer and duodenal ulcer both arose or became more frequent in Europe in the 19th century. Here, we show that gastric cancer and gastric ulcer were present throughout the 17th to 19th centuries consistent with atrophic gastritis being the predominant pattern, as it proved to be when it could be examined directly in the late 19th century. The environment before the 20th century favored acquisition of H. pylori infection and atrophic gastritis (e.g., poor sanitation and standards of living, seasonal diets poor in fresh fruits and vegetables, especially in winter, vitamin deficiencies, and frequent febrile infections in childhood). The latter part of the 19th century saw improvements in standards of living, sanitation, and diets with a corresponding decrease in rate of development of atrophic gastritis allowing duodenal ulcers to become more prominent. In the early 20th century physician’s believed they could diagnose ulcers clinically and that the diagnosis required hospitalization for “surgical disease” or for “Sippy” diets. We show that while H. pylori remained common and virulent in Europe and the United States, environmental changes resulted in changes of the pattern of gastritis producing a change in the manifestations of H. pylori infections and subsequently to a rapid decline in transmission and a rapid decline in all H. pylori

  14. Transformation of Monoaromatic hydrocarbons to organic acids in anoxic groundwater environment

    USGS Publications Warehouse

    Cozzarelli, I.M.; Eganhouse, R.P.; Baedecker, M.J.

    1990-01-01

    The transformation of benzene and a series of alkylbenzenes was studied in anoxic groundwater of a shallow glacial-outwash aquifer near Bemidji, Minnesota, U.S.A. Monoaromatic hydrocarbons, the most water-soluble components of crude oil, were transported downgradient of an oil spill, forming a plume of contaminated groundwater. Organic acids that were not original components of the oil were identified in the anoxic groundwater. The highest concentrations of these oxidized organic compounds were found in the anoxic plume where a decrease in concentrations of structurally related alkylbenzenes was observed. These results suggest that biological transformation of benzene and alkylbenzenes to organic acid intermediates may be an important attenuation process in anoxic environments. The transformation of a complex mixture of hydrocarbons to a series of corresponding oxidation products in an anoxic subsurface environment provides new insight into in situ anaerobic degradation processes. ?? 1990 Springer-Verlag New York Inc.

  15. The Prevalence of STIV c92-Like Proteins in Acidic Thermal Environments.

    PubMed

    Snyder, Jamie C; Bolduc, Benjamin; Bateson, Mary M; Young, Mark J

    2011-01-01

    A new type of viral-induced lysis system has recently been discovered for two unrelated archaeal viruses, STIV and SIRV2. Prior to the lysis of the infected host cell, unique pyramid-like lysis structures are formed on the cell surface by the protrusion of the underlying cell membrane through the overlying external S-layer. It is through these pyramid structures that assembled virions are released during lysis. The STIV viral protein c92 is responsible for the formation of these lysis structures. We searched for c92-like proteins in viral sequences present in multiple viral and cellular metagenomic libraries from Yellowstone National Park acidic hot spring environments. Phylogenetic analysis of these proteins demonstrates that, although c92-like proteins are detected in these environments, some are quite divergent and may represent new viral families. We hypothesize that this new viral lysis system is common within diverse archaeal viral populations found within acidic hot springs. PMID:22312348

  16. The influence of mechanochemical modification on prevention of toxic ability of humic acids towards phenanthrene in aquatic environment

    NASA Astrophysics Data System (ADS)

    Shekhovtsova, N. S.; Maltseva, E. V.; Glyzina, T. S.; Ovchinnikova, I. S.

    2015-11-01

    The aim of the research work is to quantify interaction between phenanthrene with modified humic acids in aquatic environment. The changes in the structure and properties of humic acids after modifications were studied with 1H NMR spectroscopy and potentiometric titration methods. Our research demonstrates that the application of thiourea as a modified agent increases the binding capacity of humic acids towards phenanthrene.

  17. Extracellular acidity, a "reappreciated" trait of tumor environment driving malignancy: perspectives in diagnosis and therapy.

    PubMed

    Peppicelli, Silvia; Bianchini, Francesca; Calorini, Lido

    2014-09-01

    Tumors are ecosystems which develop from stem cells endowed with unlimited self-renewal capability and genetic instability, under the effects of mutagenesis and natural selection imposed by environmental changes. Abnormal vascularization, reduced lymphatic network, uncontrolled cell growth frequently associated with hypoxia, and extracellular accumulation of glucose metabolites even in the presence of an adequate oxygen level are all factors contributing to reduce pH in the extracellular space of tumors. Evidence is accumulating that acidity is associated with a poor prognosis and participates actively to tumor progression. This review addresses some of the most experimental evidences providing that acidity of tumor environment facilitates local invasiveness and metastatic dissemination, independently from hypoxia, with which acidity is often but not always associated. Clinical investigations have also shown that tumors with acidic environment are associated with resistance to chemotherapy and radiation-induced apoptosis, suppression of cytotoxic lymphocytes, and natural killer cells tumoricidal activity. Therefore, new technologies for functional and molecular imaging as well as strategies directed to target low extracellular pH and low pH-adapted tumor cells might represent important issues in oncology. PMID:24984804

  18. Direct Detection of the Biological Toxin in Acidic Environment by Electrochemical Impedimetric Immunosensor

    PubMed Central

    Chai, Changhoon; Lee, Jooyoung; Takhistov, Paul

    2010-01-01

    This study describes the direct detection of the biological toxin (Ricin) in acidic environment without pH adjustment by hydrophobically modified electrochemical impedance immunosensor (EII). The nano-porous aluminum substrate for EII was hydrophobically modified via self-assembled monolayer (SAM) of APTES. Biosensor for the detection of the Ricin was fabricated by the covalent cross-linking of antibody (Ab) with APTES-SAM. The immunoreactions between the immobilized Ab and the biological toxin in several diagnostic solutions were monitored by the electrochemical impedance spectroscopy (EIS) under the polarization of EII versus reference electrode. EII could detect the presence of the biological toxin in acidic foods in 20 mins without pH adjustment. The negatively charged ions including hydroxides would be adsorbed on the hydrophobic body of APTES-SAMs by the polarization during EIS analysis, and offset the effect of acids on the immunological activity of the immobilized Ab. It suggested that the adsorption of negatively charged ions helped to keep the immunological activities of the immobilized Ab on EII in acidic environment. Proposed mechanism of the localized pH adjustment that makes possible immunoreaction occurrence in low pH sample matrix is briefly discussed. PMID:22163535

  19. Gallic acid inhibits gastric cancer cells metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity

    SciTech Connect

    Ho, Hsieh-Hsun; Chang, Chi-Sen; Ho, Wei-Chi; Liao, Sheng-You; Lin, Wea-Lung; Wang, Chau-Jong

    2013-01-01

    Our previous study demonstrated the therapeutic potential of gallic acid (GA) for controlling tumor metastasis through its inhibitory effect on the motility of AGS cells. A noteworthy finding in our previous experiment was increased RhoB expression in GA-treated cells. The aim of this study was to evaluate the role of RhoB expression on the inhibitory effects of GA on AGS cells. By applying the transfection of RhoB siRNA into AGS cells and an animal model, we tested the effect of GA on inhibition of tumor growth and RhoB expression. The results confirmed that RhoB-siRNA transfection induced GA to inhibit AGS cells’ invasive growth involving blocking the AKT/small GTPase signals pathway and inhibition of NF-κB activity. Finally, we evaluated the effect of GA on AGS cell metastasis by colonization of tumor cells in nude mice. It showed GA inhibited tumor cells growth via the expression of RhoB. These data support the inhibitory effect of GA which was shown to inhibit gastric cancer cell metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity. Thus, GA might be a potential agent in treating gastric cancer. Highlights: ► GA could downregulate AKT signal via increased expression of RhoB. ► GA inhibits metastasis in vitro in gastric carcinoma. ► GA inhibits tumor growth in nude mice model.

  20. Update on gastric varices

    PubMed Central

    Triantafyllou, Maria; Stanley, Adrian J

    2014-01-01

    Although less common than oesophageal variceal haemorrhage, gastric variceal bleeding remains a serious complication of portal hypertension, with a high associated mortality. In this review we provide an update on the aetiology, classification and management of gastric varices, including acute bleeding, prevention of rebleeding and primary prophylaxis. We describe the optimum management strategies for gastric varices including drug, endoscopic and radiological therapies, focusing on recent published evidence. PMID:24891929

  1. Ureases as a target for the treatment of gastric and urinary infections.

    PubMed

    Follmer, C

    2010-05-01

    Urease is known to be a major contributor to pathologies induced by Helicobacter pylori and Proteus species. In H pylori, urease allows the bacteria to survive in an acidic gastric environment during colonisation, playing an important role in the pathogenesis of gastric and peptic ulcers. Ureolytic activity also results in the production of ammonia in close proximity to the gastric epithelium, causing cell damage and inflammation. In the case of Proteus species (notably Proteus mirabilis) infection, stones are formed due to the presence of ammonia and carbon dioxide released by urease action. In addition, the ammonia released is able to damage the glycosaminoglycan layer, which protects the urothelial surface against bacterial infection. In this context, the administration of urease inhibitors may be an effective therapy for urease-dependent pathogenic bacteria. This is a review of the role of ureases in H pylori and Proteus species infections, focussing on the biochemical and clinical aspects of the most promising and/or potent urease inhibitors for the treatment of gastric and urinary tract infections. PMID:20418234

  2. Selective gene expression by rat gastric corpus epithelium

    PubMed Central

    Goebel, M.; Stengel, A.; Sachs, G.

    2011-01-01

    The gastrointestinal (GI) tract is divided into several segments that have distinct functional properties, largely absorptive. The gastric corpus is the only segment thought of as largely secretory. Microarray hybridization of the gastric corpus mucosal epithelial cells was used to compare gene expression with other segments of the columnar GI tract followed by statistical data subtraction to identify genes selectively expressed by the rat gastric corpus mucosa. This provides a means of identifying less obvious specific functions of the corpus in addition to its secretion-related genes. For example, important properties found by this GI tract comparative transcriptome reflect the energy demand of acid secretion, a role in lipid metabolism, the large variety of resident neuroendocrine cells, responses to damaging agents and transcription factors defining differentiation of its epithelium. In terms of overlap of gastric corpus genes with the rest of the GI tract, the distal small bowel appears to express many of the gastric corpus genes in contrast to proximal small and large bowel. This differential map of gene expression by the gastric corpus epithelium will allow a more detailed description of major properties of the gastric corpus and may lead to the discovery of gastric corpus cell differentiation genes and those mis-regulated in gastric carcinomas. PMID:21177383

  3. Sensor capsule for diagnosis of gastric disorders

    NASA Technical Reports Server (NTRS)

    Holen, J. T.

    1972-01-01

    Motility and pH sensor capsule is developed to monitor gastric acidity, pressure, and temperature. Capsule does not interfere with digestion. Sensor is capsule which includes pH electrode, Pitran pressure transducer, and thermistor temperature sensor all potted in epoxy and enclosed in high density polyethylene sheath.

  4. Current Status on Stem Cells and Cancers of the Gastric Epithelium

    PubMed Central

    Hoffmann, Werner

    2015-01-01

    Gastric cancer is still a leading cause of cancer-related mortality worldwide in spite of declining incidence. Gastric cancers are, essentially, adenocarcinomas and one of the strongest risk factors is still infection with Helicobacter pylori. Within the last years, it became clear that gastric self-renewal and carcinogenesis are intimately linked, particularly during chronic inflammatory conditions. Generally, gastric cancer is now regarded as a disease resulting from dysregulated differentiation of stem and progenitor cells, mainly due to an inflammatory environment. However, the situation in the stomach is rather complex, consisting of two types of gastric units which show bidirectional self-renewal from an unexpectedly large variety of progenitor/stem cell populations. As in many other tumors, cancer stem cells have also been characterized for gastric cancer. This review focuses on the various gastric epithelial stem cells, how they contribute to self-renewal and which routes are known to gastric adenocarcinomas, including their stem cells. PMID:26287172

  5. Effects of the Ca2+ chelators EGTA and EDTA on ethanol- or stress-induced gastric mucosal lesions and gastric secretion.

    PubMed

    Glavin, G B; Szabo, S

    1993-03-23

    Ca2+ modulates gastric function and dysfunction as well as the release of cysteine proteases and metalloproteinases which have been implicated in the pathogenesis of gastric mucosal lesions. We thus tested the hypothesis that pretreatment with the Ca2+ chelators, ethylene diamine tetraacetic acid (EDTA) and ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) might reduce the experimental gastric mucosal damage induced by restraint cold stress or 1.0 ml of 75% ethanol. Other rats were prepared with chronic indwelling gastric cannulas and the effects of EDTA and EGTA on conscious basal gastric acid output were assessed. In addition, rats were pretreated with EGTA or EDTA prior to pylorus ligation and their effects on acid and pepsin output assessed. Both EDTA and EGTA reduced significantly the extent of ethanol-induced gastric mucosal damage as well as the degree of stress-induced gastric lesions. To further characterize the mechanism of Ca2+ chelator protection against ethanol-induced gastric lesions, some rats were vagotomized or adrenalectomized prior to treatment with EGTA or EDTA, followed by ethanol or stress. Both adrenalectomy and vagotomy abolished gastroprotection by EGTA and slightly reduced that induced by EDTA in both models of experimental gastric mucosal injury. Both EDTA and EGTA reduced significantly basal gastric acid output, an effect which persisted for at least 2 h following their administration. Both compounds also decreased significantly acid and pepsin output in pylorus-ligated rats. We conclude that Ca2+ chelators attenuate both acid-dependent and acid-independent gastric lesions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8467872

  6. Acetic Acid Bacterial Biota of the Pink Sugar Cane Mealybug, Saccharococcus sacchari, and Its Environs

    PubMed Central

    Ashbolt, Nicholas J.; Inkerman, Peter A.

    1990-01-01

    Saccharococcus sacchari is the primary colonizer of the developing “sterile” tissue between the leaf sheath and stem of sugar cane. The honeydew secreted by the mealybugs is acidic (about pH 3) and supports an atypical epiphytic microbiota dominated by acetobacter-like bacteria and acidophilic yeast species. However, Erwinia and Leuconostoc species predominate within the leaf sheath pocket region when the mealybugs die out. The unidentified acetobacters were readily isolated from S. sacchari throughout its life cycle and from other genera of mealybugs on sugar cane and various other plants, both above and below ground. No other insect present on sugar cane was a significant vector of acetic acid bacteria. The major factors restricting microbial diversity within the environs of mealybugs were considered to be yeast activity along with bacterial production of acetic acid, ketogluconic acids, and gamma-pyrones, in association with their lowering of pH. The microbial products may aid in suppressing the attack by the parasitic mold Aspergillus parasiticus on mealybugs but could act as attractants for the predatory fruit fly Cacoxenus perspicax. PMID:16348144

  7. Humic and fluvic acids and organic colloidal materials in the environment

    SciTech Connect

    Gaffney, J.S.; Marley, N.A.; Clark, S.B.

    1996-04-01

    Humic substances are ubiquitous in the environment, occurring in all soils, waters, and sediments of the ecosphere. Humic substances arise from the decomposition of plant and animal tissues yet are more stable than their precursors. Their size, molecular weight, elemental composition, structure, and the number and position of functional groups vary, depending on the origin and age of the material. Humic and fulvic substances have been studied extensively for more than 200 years; however, much remains unknown regarding their structure and properties. Humic substances are those organic compounds found in the environment that cannot be classified as any other chemical class of compounds. They are traditionally defined according to their solubilities. Fulvic acids are those organic materials that are soluble in water at all pH values. Humic acids are those materials that are insoluble at acidic pH values (pH < 2) but are soluble at higher pH values. Humin is the fraction of natural organic materials that is insoluble in water at all pH values. These definitions reflect the traditional methods for separating the different fractions from the original mixture. The humic content of soils varies from 0 to almost 10%. In surface waters, the humic content, expressed as dissolved organic carbon (DOC), varies from 0.1 to 50 ppm in dark-water swamps. In ocean waters, the DOC varies from 0.5 to 1.2 ppm at the surface, and the DOC in samples from deep groundwaters varies from 0.1 to 10 ppm. In addition, about 10% of the DOC in surface waters is found in suspended matter, either as organic or organically coated inorganic particulates. Humic materials function as surfactants, with the ability to bind both hydrophobic and hydrophyllic materials, making numic and fluvic materials effective agents in transporting both organic and inorganic contaminants in the environment.

  8. Bacillus cereus cell response upon exposure to acid environment: toward the identification of potential biomarkers

    PubMed Central

    Desriac, Noémie; Broussolle, Véronique; Postollec, Florence; Mathot, Anne-Gabrielle; Sohier, Danièle; Coroller, Louis; Leguerinel, Ivan

    2013-01-01

    Microorganisms are able to adapt to different environments and evolve rapidly, allowing them to cope with their new environments. Such adaptive response and associated protections toward other lethal stresses, is a crucial survival strategy for a wide spectrum of microorganisms, including food spoilage bacteria, pathogens, and organisms used in functional food applications. The growing demand for minimal processed food yields to an increasing use of combination of hurdles or mild preservation factors in the food industry. A commonly used hurdle is low pH which allows the decrease in bacterial growth rate but also the inactivation of pathogens or spoilage microorganisms. Bacillus cereus is a well-known food-borne pathogen leading to economical and safety issues in food industry. Because survival mechanisms implemented will allow bacteria to cope with environmental changes, it is important to provide understanding of B. cereus stress response. Thus this review deals with the adaptive traits of B. cereus cells facing to acid stress conditions. The acid stress response of B. cereus could be divided into four groups (i) general stress response (ii) pH homeostasis, (iii) metabolic modifications and alkali production and (iv) secondary oxidative stress response. This current knowledge may be useful to understand how B. cereus cells may cope to acid environment such as encountered in food products and thus to find some molecular biomarkers of the bacterial behavior. These biomarkers could be furthermore used to develop new microbial behavior prediction tools which can provide insights into underlying molecular physiological states which govern the behavior of microorganisms and thus opening the avenue toward the detection of stress adaptive behavior at an early stage and the control of stress-induced resistance throughout the food chain. PMID:24106490

  9. Bacillus cereus cell response upon exposure to acid environment: toward the identification of potential biomarkers.

    PubMed

    Desriac, Noémie; Broussolle, Véronique; Postollec, Florence; Mathot, Anne-Gabrielle; Sohier, Danièle; Coroller, Louis; Leguerinel, Ivan

    2013-01-01

    Microorganisms are able to adapt to different environments and evolve rapidly, allowing them to cope with their new environments. Such adaptive response and associated protections toward other lethal stresses, is a crucial survival strategy for a wide spectrum of microorganisms, including food spoilage bacteria, pathogens, and organisms used in functional food applications. The growing demand for minimal processed food yields to an increasing use of combination of hurdles or mild preservation factors in the food industry. A commonly used hurdle is low pH which allows the decrease in bacterial growth rate but also the inactivation of pathogens or spoilage microorganisms. Bacillus cereus is a well-known food-borne pathogen leading to economical and safety issues in food industry. Because survival mechanisms implemented will allow bacteria to cope with environmental changes, it is important to provide understanding of B. cereus stress response. Thus this review deals with the adaptive traits of B. cereus cells facing to acid stress conditions. The acid stress response of B. cereus could be divided into four groups (i) general stress response (ii) pH homeostasis, (iii) metabolic modifications and alkali production and (iv) secondary oxidative stress response. This current knowledge may be useful to understand how B. cereus cells may cope to acid environment such as encountered in food products and thus to find some molecular biomarkers of the bacterial behavior. These biomarkers could be furthermore used to develop new microbial behavior prediction tools which can provide insights into underlying molecular physiological states which govern the behavior of microorganisms and thus opening the avenue toward the detection of stress adaptive behavior at an early stage and the control of stress-induced resistance throughout the food chain. PMID:24106490

  10. Using nitrile-derivatized amino acids as infrared probes of local environment.

    PubMed

    Getahun, Zelleka; Huang, Cheng-Yen; Wang, Ting; De León, Brenda; DeGrado, William F; Gai, Feng

    2003-01-15

    It is well-known that the C=N stretching vibration in acetonitrile is sensitive to solvent. Therefore, we proposed in this contribution to use this vibrational mode to report local environment of a particular amino acid in proteins or local environmental changes upon binding or folding. We have studied the solvent-induced frequency shift of two nitrile-derivatized amino acids, which are, AlaCN and PheCN, in H(2)O and tetrahydrofuran (THF), respectively. Here, THF was used to approximate a protein's hydrophobic interior because of its low dielectric constant. As expected, the C=N stretching vibrations of both AlaCN and PheCN shift as much as approximately 10 cm(-1) toward higher frequency when THF was replaced with H2O, indicative of the sensitivity of this vibration to solvation. To further test the utility of nitrile-derivatized amino acids as probes of the environment within a peptide, we have studied the binding between calmodulin (CaM) and a peptide from the CaM binding domain of skeletal muscle myosin light chain kinase (MLCK(579-595)), which contains a single PheCN. MLCK(579-595) binds to CaM in a helical conformation. When the PheCN was substituted on the polar side of the helix, which was partially exposed to water, the C=N stretching vibration is similar to that of PheCN in water. In constrast, when PheCN is introduced at a site that becomes buried in the interior of the protein, the C=N stretch is similar to that of PheCN in THF. Together, these results suggest that the C=N stretching vibration of nitrile-derivatized amino acids can indeed be used as local internal environmental markers, especially for protein conformational studies. PMID:12517152

  11. Distribution and diversity of Verrucomicrobia methanotrophs in geothermal and acidic environments.

    PubMed

    Sharp, Christine E; Smirnova, Angela V; Graham, Jaime M; Stott, Matthew B; Khadka, Roshan; Moore, Tim R; Grasby, Stephen E; Strack, Maria; Dunfield, Peter F

    2014-06-01

    Recently, methanotrophic members of the phylum Verrucomicrobia have been described, but little is known about their distribution in nature. We surveyed methanotrophic bacteria in geothermal springs and acidic wetlands via pyrosequencing of 16S rRNA gene amplicons. Putative methanotrophic Verrucomicrobia were found in samples covering a broad temperature range (22.5-81.6°C), but only in acidic conditions (pH 1.8-5.0) and only in geothermal environments, not in acidic bogs or fens. Phylogenetically, three 16S rRNA gene sequence clusters of putative methanotrophic Verrucomicrobia were observed. Those detected in high-temperature geothermal samples (44.1-81.6°C) grouped with known thermoacidiphilic 'Methylacidiphilum' isolates. A second group dominated in moderate-temperature geothermal samples (22.5-40.1°C) and a representative mesophilic methanotroph from this group was isolated (strain LP2A). Genome sequencing verified that strain LP2A possessed particulate methane monooxygenase, but its 16S rRNA gene sequence identity to 'Methylacidiphilum infernorum' strain V4 was only 90.6%. A third group clustered distantly with known methanotrophic Verrucomicrobia. Using pmoA-gene targeted quantitative polymerase chain reaction, two geothermal soil profiles showed a dominance of LP2A-like pmoA sequences in the cooler surface layers and 'Methylacidiphilum'-like pmoA sequences in deeper, hotter layers. Based on these results, there appears to be a thermophilic group and a mesophilic group of methanotrophic Verrucomicrobia. However, both were detected only in acidic geothermal environments. PMID:24650084

  12. Antioxidant activity of olive phenols and other dietary phenols in model gastric conditions: Scavenging of the free radical DPPH and inhibition of the haem-induced peroxidation of linoleic acid.

    PubMed

    Achat, Sabiha; Rakotomanomana, Njara; Madani, Khodir; Dangles, Olivier

    2016-12-15

    The antioxidant activity of dietary phenols in humans (direct reduction of radicals and other highly oxidizing species) could be largely restricted to fighting postprandial oxidative stress in the gastric compartment. Hence, the development of chemical tests simply modelling this situation is pertinent. In this work, the antioxidant properties of the olive phenols hydroxytyrosol and oleuropein are investigated in pH 5-6 micellar solutions through the reduction of the DPPH radical and the inhibition of the metmyoglobin-induced peroxidation of linoleic acid. In the first test, hydroxytyrosol and oleuropein proved as efficient as common polyphenols and their reactivity was only moderately affected by β-cyclodextrin and bovine serum albumin, taken as models of food macromolecules. In the second test, hydroxytyrosol and oleuropein by themselves came up as relatively weak inhibitors, despite their efficiency at reducing hypervalent haem iron. However, hydroxytyrosol was able to act in synergy with the typical chain-breaking antioxidant α-tocopherol. PMID:27451164

  13. Development of a New Environment-conscious Transformer Impregnated with Palm Fatty Acid Ester (PFAE)

    NASA Astrophysics Data System (ADS)

    Hikosaka, Tomoyuki; Yamazaki, Akina; Hatta, Yasunori; Koide, Hidenobu; Kanoh, Takaaki; Suzuki, Takashi; Yamada, Junichi; Uemura, Shingo

    We have developed a new environment-conscious transformer impregnated with vegetable based insulating oil which called PFAE (Palm Fatty Acid Ester). PFAE has 0.6 times less viscosity and 1.3 times higher dielectric constant compared to mineral oil. This means that a PFAE immersed transformer has better cooling efficiency and better insulating performance in paper-and-oil composite insulation systems, resulting in size reduction in comparison to conventional mineral oil immersed transformers. In this paper, insulating performance of lead to plane electrode models, cooling performance of a PFAE immersed transformer, and the result of analytical study of dissolved gas for abnormal diagnosis are described.

  14. NMR chemical shifts in amino acids: Effects of environments, electric field, and amine group rotation

    SciTech Connect

    Yoon, Young-Gui; Pfrommer, Bernd G.; Louie, Steven G.; Canning, Andrew

    2002-03-03

    The authors present calculations of NMR chemical shifts in crystalline phases of some representative amino acids such as glycine, alanine, and alanyl-alanine. To get an insight on how different environments affect the chemical shifts, they study the transition from the crystalline phase to completely isolated molecules of glycine. In the crystalline limit, the shifts are dominated by intermolecular hydrogen-bonds. In the molecular limit, however, dipole electric field effects dominate the behavior of the chemical shifts. They show that it is necessary to average the chemical shifts in glycine over geometries. Tensor components are analyzed to get the angle dependent proton chemical shifts, which is a more refined characterization method.

  15. Treatment of gastric cancer

    PubMed Central

    Orditura, Michele; Galizia, Gennaro; Sforza, Vincenzo; Gambardella, Valentina; Fabozzi, Alessio; Laterza, Maria Maddalena; Andreozzi, Francesca; Ventriglia, Jole; Savastano, Beatrice; Mabilia, Andrea; Lieto, Eva; Ciardiello, Fortunato; De Vita, Ferdinando

    2014-01-01

    The authors focused on the current surgical treatment of resectable gastric cancer, and significance of peri- and post-operative chemo or chemoradiation. Gastric cancer is the 4th most commonly diagnosed cancer and the second leading cause of cancer death worldwide. Surgery remains the only curative therapy, while perioperative and adjuvant chemotherapy, as well as chemoradiation, can improve outcome of resectable gastric cancer with extended lymph node dissection. More than half of radically resected gastric cancer patients relapse locally or with distant metastases, or receive the diagnosis of gastric cancer when tumor is disseminated; therefore, median survival rarely exceeds 12 mo, and 5-years survival is less than 10%. Cisplatin and fluoropyrimidine-based chemotherapy, with addition of trastuzumab in human epidermal growth factor receptor 2 positive patients, is the widely used treatment in stage IV patients fit for chemotherapy. Recent evidence supports the use of second-line chemotherapy after progression in patients with good performance status PMID:24587643

  16. Not all gastric masses are gastric cancer.

    PubMed

    Del Rosario, Michael; Tsai, Henry

    2016-01-01

    Lung cancer metastasising to the gastrointestinal tract normally does not occur. However, as clinicians, we must be aware that lung adenocarcinoma, as in all cancers, can and will metastasise to any part of the body. We describe a case of a patient with a presumed primary gastric adenocarcinoma who presented with shortness of breath due to pleural effusion. Pathology from the pleural effusion was positive for primary lung adenocarcinoma. Further investigation revealed that the patient's gastric mass was misdiagnosed as gastric adenocarcinoma. We correctly diagnosed the mass as metastatic lung adenocarcinoma. This was very significant because the patient was transitioning to palliative care with possible tube feeding. After the correct diagnosis, her management drastically changed and her health improved. Clinical, pathological and medical management of lung cancer metastasis to the stomach are discussed. PMID:26976833

  17. Fatty acid-binding site environments of serum vitamin D-binding protein and albumin are different

    PubMed Central

    Swamy, Narasimha; Ray, Rahul

    2008-01-01

    Vitamin D-binding protein (DBP) and albumin (ALB) are abundant serum proteins and both possess high-affinity binding for saturated and unsaturated fatty acids. However, certain differences exist. We surmised that in cases where serum albumin level is low, DBP presumably can act as a transporter of fatty acids. To explore this possibility we synthesized several alkylating derivatives of 14C-palmitic acid to probe the fatty acid binding pockets of DBP and ALB. We observed that N-ethyl-5-phenylisooxazolium-3′-sulfonate-ester (WRK ester) of 14C-palmitic acid specifically labeled DBP; but p-nitrophenyl- and N-hydroxysuccinimidyl-esters failed to do so. However, p-nitrophenyl ester of 14C-palmitic acid specifically labeled bovine ALB, indicating that the micro-environment of the fatty acid-binding domains of DBP and ALB may be different; and DBP may not replace ALB as a transporter of fatty acids. PMID:18374965

  18. Tests of gastric neuromuscular function.

    PubMed

    Parkman, Henry P; Jones, Michael P

    2009-05-01

    Tests of gastric neuromuscular function are used to evaluate patients with symptoms referable to the upper digestive tract. These symptoms can be associated with alterations in the rates of gastric emptying, impaired accommodation, heightened gastric sensation, or alterations in gastric myoelectrical function and contractility. Management of gastric neuromuscular disorders requires an understanding of pathophysiology and treatment options as well as the appropriate use and interpretation of diagnostic tests. These tests include measures of gastric emptying; contractility; electrical activity; regional gastric motility of the fundus, antrum, and pylorus; and tests of sensation and compliance. Tests are also being developed to improve our understanding of the afferent sensory pathways from the stomach to the central nervous system that mediate gastric sensation in health and gastric disorders. This article reviews tests of gastric function and provides a basic description of the tests, the methodologies behind them, descriptions of the physiology that they assess, and their clinical utility. PMID:19293005

  19. Gastric Mucosal Protection by Aegle Marmelos Against Gastric Mucosal Damage: Role of Enterochromaffin Cell and Serotonin

    PubMed Central

    Singh, Purnima; Dutta, Shubha R.; Guha, Debjani

    2015-01-01

    Background/Aims: Serotonin (5-hydroxytryptamine; 5-HT) released from enterochromaffin (EC) cells in gastric mucosa inhibits gastric acidity by increasing the gastric mucus secretion. In the present study, we evaluated the effect of aqueous extract of Aegle marmelos (AM) ripe fruit pulp (250 mg/kg body weight) on mean ulcer index (MUI), EC cells, 5-HT content, and adherent mucosal thickness of ulcerated gastric tissue in adult albino rats. Material and Methods: Ulceration was induced by using aspirin (500 mg/kg, p.o.), cerebellar nodular lesion and applying cold-restraint stress. Results: In all cases increased MUI in gastric tissue along with decreased EC cell count was observed with concomitant decrease of 5-HT content and adherent mucosal thickness (P < 0.05). Pretreatment with AM for 14 days decreased MUI, increased EC cell count, and 5-HT content as well as adherent mucosal thickness in all ulcerated group (P < 0.05). Conclusion: AM produces gastric mucosal protection mediated by increased EC cell count and 5-HT levels. PMID:25672237

  20. Trophic relationships in an estuarine environment: A quantitative fatty acid analysis signature approach

    NASA Astrophysics Data System (ADS)

    Magnone, Larisa; Bessonart, Martin; Gadea, Juan; Salhi, María

    2015-12-01

    In order to better understand the functioning of aquatic environments, it is necessary to obtain accurate diet estimations in food webs. Their description should incorporate information about energy flow and the relative importance of trophic pathways. Fatty acids have been extensively used in qualitative studies on trophic relationships in food webs. Recently a new method to estimate quantitatively single predator diet has been developed. In this study, a model of aquatic food web through quantitative fatty acid signature analysis was generated to identify the trophic interactions among the species in the Rocha Lagoon. The biological sampling over two consecutive annual periods was comprehensive enough to identify all functional groups in the aquatic food web (except birds and mammals). Heleobia australis seemed to play a central role in this estuarine ecosystem. As both, a grazer and a prey to several other species, probably H. australis is transferring a great amount of energy to upper trophic levels. Most of the species at Rocha Lagoon have a wide range of prey items in their diet reflecting a complex food web, which is characteristic of extremely dynamic environment as estuarine ecosystems. QFASA is a model in tracing and quantitative estimate trophic pathways among species in an estuarine food web. The results obtained in the present work are a valuable contribution in the understanding of trophic relationships in Rocha Lagoon.

  1. Placement in an acidic environment increase the solubility of white mineral trioxide aggregate

    PubMed Central

    Yavari, Hamid Reza; Borna, Zahra; Rahimi, Saeed; Shahi, Shahriar; Valizadeh, Hadi; Ghojazadeh, Morteza

    2013-01-01

    Aims: The aim of the present study was to evaluate solubility of white mineral trioxide aggregate (WMTA) in an acidic environment. Materials and Methods: Twenty-four metal rings were prepared, filled with WMTA and randomly divided into two groups. The samples in groups 1 and 2 were set in synthetic tissue fluid with pH values of 7.4 and 4.4, respectively and then were transferred to beakers containing synthetic tissue fluid with pH values of 7.7 and 4.4. Solubility of WMTA samples were calculated at the 9 experimental intervals. Data was analyzed with two-factor ANOVA and Bonferroni test (P < 0.03). Results: The total solubility of WMTA in groups 1 and 2 were −9.1796 ± 1.9158% and −1.1192 ± 2.6236%, (P = 0.028) with weight changes of 9.1574 ± 2.1432% and 7.3276 ± 1.5823%, respectively (P = 0.002). Statistical analysis revealed significant differences between the two groups. Conclusions: It was concluded that solubility of WMTA increases in acidic environments and additional therapeutic precautions should be taken to decrease inflammation in endodontic treatment. PMID:23833462

  2. Spectral identification of hydrated sulfates on Mars and comparison with acidic environments on Earth

    NASA Astrophysics Data System (ADS)

    Bishop, Janice L.; Darby Dyar, M.; Lane, Melissa D.; Banfield, Jillian F.

    2004-10-01

    We interpret recent spectral data of Mars collected by the Mars Exploration Rovers to contain substantial evidence of sulfate minerals and aqueous processes. We present visible/near-infrared (VNIR), mid-IR and Mössbauer spectra of several iron sulfate minerals and two acid mine drainage (AMD) samples collected from the Iron Mountain site and compare these combined data with the recent spectra of Mars. We suggest that the sulfates on Mars are produced via aqueous oxidation of sulfides known to be present on Mars from Martian meteorites. The sulfate-rich rock outcrops observed in Meridiani Planum may have formed in an acidic environment similar to AMD environments on Earth. Because microorganisms are typically involved in the oxidation of sulfides to sulfates in terrestrial AMD sites, sulfate-rich rock outcrops on Mars may be a good location to search for evidence of life on that planet. Whether or not life evolved on Mars, following the trail of sulfate minerals is likely to lead to aqueous processes and chemical weathering. Our results imply that sulfate minerals formed in Martian soils via chemical weathering, perhaps over very long time periods, and that sulfate minerals precipitated following aqueous oxidation of sulfides to form the outcrop rocks at Meridiani Planum.

  3. A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices

    SciTech Connect

    Zhang, Shiyi; Bellinger, Andrew M.; Glettig, Dean L.; Barman, Ross; Lee, Young-Ah Lucy; Zhu, Jiahua; Cleveland, Cody; Montgomery, Veronica A.; Gu, Li; Nash, Landon D.; Maitland, Duncan J.; Langer, Robert; Traverso, Giovanni

    2015-07-27

    Devices resident in the stomach used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric-retentive dosage forms for prolonged drug delivery typically incorporate elastic polymers to compress the devices during delivery through the oesophagus and other narrow orifices in the digestive system. In the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. We determine that these enteric elastomers should increase the safety profile for a wide range of gastricretentive devices.

  4. A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices

    SciTech Connect

    Zhang, Shiyi; Bellinger, Andrew M; Glettig, Dean L; Barman, Ross; Lee, Young-Ah Lucy; Zhu, Jiahua; Cleveland, Cody; Montgomery, Veronica A; Gu, Li; Nash, Landon D; Maitland, Duncan J; Langer, Robert; Traverso, Giovanni

    2015-01-01

    Devices resident in the stomach used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric-retentive dosage forms for prolonged drug delivery typically incorporate elastic polymers to compress the devices during delivery through the oesophagus and other narrow orifices in the digestive system. However, in the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. These enteric elastomers should increase the safety profile for a wide range of gastricretentive devices.

  5. A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices

    DOE PAGESBeta

    Zhang, Shiyi; Bellinger, Andrew M.; Glettig, Dean L.; Barman, Ross; Lee, Young-Ah Lucy; Zhu, Jiahua; Cleveland, Cody; Montgomery, Veronica A.; Gu, Li; Nash, Landon D.; et al

    2015-07-27

    Devices resident in the stomach used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric-retentive dosage forms for prolonged drug delivery typically incorporate elastic polymers to compress the devices during delivery through the oesophagus and other narrow orifices in the digestive system. In the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of themore » small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. We determine that these enteric elastomers should increase the safety profile for a wide range of gastricretentive devices.« less

  6. Experimental Gastric Carcinogenesis in Cebus apella Nonhuman Primates

    PubMed Central

    Silva, Tanielly Cristina Raiol; Andrade Junior, Edilson Ferreira; Rezende, Alexandre Pingarilho; Carneiro Muniz, José Augusto Pereira; Lacreta Junior, Antonio Carlos Cunha; Assumpção, Paulo Pimentel; Calcagno, Danielle Queiroz; Demachki, Samia; Rabenhorst, Silvia Helena Barem; Smith, Marília de Arruda Cardoso; Burbano, Rommel Rodriguez

    2011-01-01

    The evolution of gastric carcinogenesis remains largely unknown. We established two gastric carcinogenesis models in New-World nonhuman primates. In the first model, ACP03 gastric cancer cell line was inoculated in 18 animals. In the second model, we treated 6 animals with N-methyl-nitrosourea (MNU). Animals with gastric cancer were also treated with Canova immunomodulator. Clinical, hematologic, and biochemical, including C-reactive protein, folic acid, and homocysteine, analyses were performed in this study. MYC expression and copy number was also evaluated. We observed that all animals inoculated with ACP03 developed gastric cancer on the 9th day though on the 14th day presented total tumor remission. In the second model, all animals developed pre-neoplastic lesions and five died of drug intoxication before the development of cancer. The last surviving MNU-treated animal developed intestinal-type gastric adenocarcinoma observed by endoscopy on the 940th day. The level of C-reactive protein level and homocysteine concentration increased while the level of folic acid decreased with the presence of tumors in ACP03-inoculated animals and MNU treatment. ACP03 inoculation also led to anemia and leukocytosis. The hematologic and biochemical results corroborate those observed in patients with gastric cancer, supporting that our in vivo models are potentially useful to study this neoplasia. In cell line inoculated animals, we detected MYC immunoreactivity, mRNA overexpression, and amplification, as previously observed in vitro. In MNU-treated animals, mRNA expression and MYC copy number increased during the sequential steps of intestinal-type gastric carcinogenesis and immunoreactivity was only observed in intestinal metaplasia and gastric cancer. Thus, MYC deregulation supports the gastric carcinogenesis process. Canova immunomodulator restored several hematologic measurements and therefore, can be applied during/after chemotherapy to increase the tolerability and

  7. Cerro Negro, Nicaragua: A key Mars Analog Environment for Acid-Sulfate Weathering

    NASA Astrophysics Data System (ADS)

    Hynek, B. M.; Rogers, K. L.; McCollom, T. M.

    2008-12-01

    Sulfate-rich bedrock has been discovered in many locations on Mars and has been studied by both orbiting spacecraft and landers. It appears that in most cases these minerals are produced by acid-sulfate weathering of igneous rocks, which may have been a widespread process for the first billion years of Mars' history. The origin of life on Earth may have occurred in iron-sulfur hydrothermal settings and it is conceivable that early Mars had similar environmental conditions. An excellent terrestrial analog for acid- sulfate weathering of Mars-like basalts exists at Cerro Negro (CN), Nicaragua, where sulfur-bearing gases interact with recently erupted basaltic ash in numerous fumaroles. To date, we have made two expeditions to CN to assess the chemical, mineralogical, and biological conditions. At the fumaroles pH ranges from <1 to 5 and temperatures range from 40 to 400° C. Basalts with a chemical composition very similar to those on Mars are being chemically altered in the solfatara setting. In a few years, freshly erupted basalt can be converted into predominately Ca-, Mg-, and Fe-sulfates, Fe-hydroxides (including jarosite), clays, and free silica. Altered rocks have up to 30 wt% SO3 equivalent, which is similar to the Meridiani Planum bedrocks and inferred in other sulfate-bearing bedrock on Mars. Moreover, heavily weathered rocks have silica contents up to 80 wt%, similar to silica-rich soils at Gusev Crater that possibly formed in hydrothermal environments. Samples were collected for biological analysis including enrichment and isolation of novel thermophiles as well as molecular characterization of thermophile diversity. The low water and nutrient levels found in solfatara environments lead to less biomass when compared to hot springs with similar geochemical conditions. Nonetheless, microbes are thriving in these hot, acidic vent environments. At Cerro Negro solfatara, we are characterizing the metabolic and phylogenetic diversity of resident microbial

  8. Screening of anaerobic activities in sediments of an acidic environment: Tinto River.

    PubMed

    Sánchez-Andrea, Irene; Rojas-Ojeda, Patricia; Amils, Ricardo; Sanz, José Luis

    2012-11-01

    The Tinto River (Huelva, Spain) is a natural acidic rock drainage environment produced by the bio-oxidation of metallic sulfides from the Iberian Pyritic Belt. A geomicrobiological model of the different microbial cycles operating in the sediments was recently developed through molecular biological methods, suggesting the presence of iron reducers, methanogens, nitrate reducers and hydrogen producers. In this study, we used a combination of molecular biological methods and targeted enrichment incubations to validate this model and prove the existence of those potential anaerobic activities in the acidic sediments of Tinto River. Methanogenic, sulfate-reducing, denitrifying and hydrogen-producing enrichments were all positive at pH between 5 and 7. Methanogenic enrichments revealed the presence of methanogenic archaea belonging to the genera Methanosarcina and Methanobrevibacter. Enrichments for sulfate-reducing microorganisms were dominated by Desulfotomaculum spp. Denitrifying enrichments showed a broad diversity of bacteria belonging to the genera Paenibacillus, Bacillus, Sedimentibacter, Lysinibacillus, Delftia, Alcaligenes, Clostridium and Desulfitobacterium. Hydrogen-producing enrichments were dominated by Clostridium spp. These enrichments confirm the presence of anaerobic activities in the acidic sediments of the Tinto River that are normally assumed to take place exclusively at neutral pH. PMID:22956355

  9. Simple, rapid method for direct isolation of nucleic acids from aquatic environments.

    PubMed Central

    Somerville, C C; Knight, I T; Straube, W L; Colwell, R R

    1989-01-01

    Direct isolation of nucleic acids from the environment may be useful in several respects, including the estimation of total biomass, detection of specific organisms and genes, estimations of species diversity, and cloning applications. We have developed a method that facilitates the concentration of microorganisms from aquatic samples and the extraction of their nucleic acids. Natural water samples of 350 to greater than 1,000 ml are concentrated on a single cylindrical filter membrane (type SVGS01015; Millipore Corp., Bedford, Mass.), and cell lysis and proteolysis are carried out within the filter housing. Crude, high-molecular-weight nucleic acid solutions are then drawn off the filter. These solutions can be immediately analyzed, concentrated, or purified, depending on the intended application. The method is simple, rapid, and economical and provides high-molecular-weight chromosomal DNA, plasmid DNA, and speciated RNAs which comigrate with 5S, 16S, and 23S rRNAs. The methods presented here should prove useful in studying both the ecology and the phylogeny of microbes that resist classical culture methods. Images PMID:2467621

  10. Antiulcerogenic effect of Securigera securidaca L. seed extract on various experimental gastric ulcer models in rats.

    PubMed

    Mard, S A; Bahari, Z; Eshaghi, N; Farbood, Y

    2008-12-01

    Securigera securidaca belongs to the family Fabaceae is used in Iranian folk medicine to treat gastric disturbances. The present study was undertaken to evaluate the Securigera securidaca seed hydroalcoholic extract (SSE) and its subfractions for their gastroprotective effect in rat. Acute gastric ulceration in rats was produced by oral administration of ethanol (100%; 1 mL/200 g of body weight) or water immersion restraint-stress (5 h, water immersion restraint stress at 20-22 degrees C). Ranitidine (100 mg kg(-1), p.o.) was used as the reference antiulcer drug. After ethanol administration, the gastric wall mucus was examined. Chronic gastric ulceration was produced by injection of acetic acid in rat gastric subserosa. The antisecretory effect of the extract and its subfractions (ethyl acetate, chloroform and aqueous fractions) were investigated in pylorus-ligated rats. Administration of SSE significantly inhibited gastric mucosa damage induced by ethanol, water immersion restraint-stress and acetic acid in a dose-dependent manner. In pylorus ligature rats, SSE and its subfractions significantly reduced the basal gastric acid secretion and total acidity; moreover, it inhibited the increase in total acidity induced by carbachol. However, the antisecretory effect of the chloroform fraction was more potent than two other fractions. Administration of SSE did not affect the gastric mucus production. The results obtained in the present study indicate that the SSE has gastroprotective and antisecretory effects on gastric mucosa in rats. PMID:19630213

  11. Enantioselective separation of amino acids as biomarkers indicating life in extraterrestrial environments.

    PubMed

    Pietrogrande, Maria Chiara

    2013-10-01

    Traces of prebiotic amino acids, i.e., the building blocks of proteins, are excellent biomarkers that could provide evidence of extinct or extant life in extra-terrestrial environments. In particular, characterization of the enantiomeric excess of amino acids gives relevant information about the biotic or abiotic origin of molecules, because it is generally assumed that life elsewhere could be based on either L or D amino acids, but not both. The analytical procedures used in in-situ space missions for chiral discrimination of amino acids must meet severe requirements imposed by flight conditions: short analysis time, low energy consumption, robustness, storage for long periods under extreme conditions, high efficiency and sensitivity, automation, and remote-control operation. Such methods are based on gas chromatography, high-pressure liquid chromatography, and capillary electrophoresis, usually coupled with mass spectrometry; of these, gas chromatography-mass spectrometry (GC-MS) is the only such combination yet used in space missions. Preliminary in-situ sample derivatization is required before GC-MS analysis to convert amino acids into volatile and thermally stable compounds. The silylation reagent most commonly used, N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide, is unsuitable for detection of homochirality, and alternative derivatization techniques have been developed that preserve the stereochemical configuration of the original compounds and are compatible with spaceflight conditions. These include the reagent N,N-dimethylformamide dimethylacetal, which has already been used in the Rosetta mission, a mixture of alkyl chloroformate, ethanol, and pyridine, a mixture of perfluorinated anhydrides and perfluoro alcohols, and hexafluoroacetone, the first gaseous derivatizing agent. In all the space instruments, solvent extraction of organic matter and chemical derivatization have been combined in a single automatic and remote-controlled procedure in a

  12. Potential role of probiotics in the management of gastric ulcer

    PubMed Central

    KHODER, GHALIA; AL-MENHALI, ASMA A.; AL-YASSIR, FARAH; KARAM, SHERIF M.

    2016-01-01

    Gastric ulcer is one of the most common chronic gastrointestinal diseases characterized by a significant defect in the mucosal barrier. Helicobacter pylori (H. pylori) infection and the frequent long-term use of non-steroidal anti-inflammatory drugs are major factors involved in gastric ulcer development. Acid inhibitors and antibiotics are commonly used to treat gastric ulcer. However, in the last few decades, the accumulating evidence for resistance to antibiotics and the side effects of antibiotics and acid inhibitors have drawn attention to the possible use of probiotics in the prevention and treatment of gastric ulcer. Probiotics are live microorganisms that when administered in adequate amounts confer health benefits on the host. Currently, the available experimental and clinical studies indicate that probiotics are promising for future applications in the management of gastric ulcers. This review aims to provide an overview of the general health benefits of probiotics on various systemic and gastrointestinal disorders with a special focus on gastric ulcer and the involved cellular and molecular mechanisms: i) Protection of gastric mucosal barrier; ii) upregulation of prostaglandins, mucus, growth factors and anti-inflammatory cytokines; iii) increased cell proliferation to apoptosis ratio; and iv) induction of angiogenesis. Finally, some of the available data on the possible use of probiotics in H. pylori eradication are discussed. PMID:27347010

  13. Environment influences on the aromatic character of nucleobases and amino acids

    PubMed Central

    Szefler, Beata

    2010-01-01

    Geometric (HOMA) and magnetic (NICS) indices of aromaticity were estimated for aromatic rings of amino acids and nucleobases. Cartesian coordinates were taken directly either from PDB files deposited in public databases at the finest resolution available (≤1.5 Å), or from structures resulting from full gradient geometry optimization in a hybrid QM/MM approach. Significant environmental effects imposing alterations of HOMA values were noted for all aromatic rings analysed. Furthermore, even extra fine resolution (≤1.0 Å) is not sufficient for direct estimation of HOMA values based on Cartesian coordinates provided by PDB files. The values of mean bond errors seem to be much higher than the 0.05 Å often reported for PDB files. The use of quantum chemistry geometry optimization is strongly advised; even a simple QM/MM model comprising only the aromatic substructure within the QM region and the rest of biomolecule treated classically within the MM framework proved to be a promising means of describing aromaticity inside native environments. According to the results presented, three consequences of the interaction with the environment can be observed that induce changes in structural and magnetic indices of aromaticity. First, broad ranges of HOMA or NICS values are usually obtained for different conformations of nearest neighborhood. Next, these values and their means can differ significantly from those characterising isolated monomers. The most significant increase in aromaticities is expected for the six-membered rings of guanine, thymine and cytosine. The same trend was also noticed for all amino acids inside proteins but this effect was much smaller, reaching the highest value for the five-membered ring of tryptophan. Explicit water solutions impose similar changes on HOMA and NICS distributions. Thus, environment effects of protein, DNA and even explicit water molecules are non-negligible sources of aromaticity changes appearing in the rings of

  14. Dissolution of PZT 52/48 in aqueous sulfuric acid environments

    NASA Astrophysics Data System (ADS)

    Calebrese, Steven

    With the recent interest for PZT use as a self-powered nanonsensor in extreme environments, such as an oil well, it is important to ensure the stability of the material under these conditions. Oil wells are known for being extremely caustic, with high temperature, low pH and high pressures. It has been shown that in the presence of sulfuric acid PZT is subject to chemical attack. This study attempts to identify the effects that pH and temperature have on the rate of the reaction. Sulfuric acid was used as a proxy for the H2S environment found in oil wells. Exposure of bulk PZT and thin film specimens to H2S was studied. PZT 52/48 thin films were fabricated via the sol gel process. PZT was exposed to both single drops of aqueous sulfuric acid and submerged in a bath of solution. During bath exposure potential on the substrate surface of thin film samples was recorded using a voltmeter vs. and Ag/AgCl reference electrode. Thin Film samples were exposed to a single drop of 0.1 N and 1 N aqueous sulfuric acid solutions at temperatures between 25° C and 92° C. It was optically observed that a white filmed appeared on the surface as a reaction product. At both concentrations, increases in temperature lead to an increase in reaction rate for droplet exposed samples. These reactions were found to follow Arrhenius behavior. The 1 N solution activation energy of film appearance was found to be 69100 J, and for 0.1 N solution was found to be 48300 J. It was expected that an increase in concentration would lead to an increase in reaction rate as well. However for single droplet exposure it was found that lower concentrations resulted in increased reaction rate. This may be due to the difference in interfacial energy between the solution and PZT surface as a result of the concentration of sulfuric acid. The potential on the substrate during bath exposure was between -0.22 V and 0.1 V. As a ferroelectric, PZT is expected to spontaneously polarize and variations in potential

  15. Comparison of the composition and gas/particle partitioning of organic acids in monoterpene and isoprene dominated environments

    NASA Astrophysics Data System (ADS)

    Thompson, S.; Yatavelli, L. R.; Stark, H.; Kimmel, J.; Krechmer, J.; Hu, W.; Palm, B. B.; Campuzano Jost, P.; Day, D. A.; Isaacman, G. A.; Goldstein, A. H.; Khan, M. H.; Holzinger, R.; Lopez-Hilfiker, F.; Mohr, C.; Thornton, J. A.; Jayne, J. T.; Worsnop, D. R.; Jimenez, J. L.

    2013-12-01

    Gas and particle-phase organic acids measurements from two different regions with different biogenic volatile organic compound emissions are used to understand gas/particle partitioning principles. A Chemical Ionization High Resolution Time-of-Flight Mass Spectrometer (HRToF-CIMS), with acetate (CH3COO-) as the reagent ion was used to selectively detect acids. Hundreds of gas and particle-phase organic acids were measured in both locations, a monoterpene and MBO-dominated environment (ponderosa pine forest in Colorado, BEACHON-RoMBAS 2011) and isoprene and terpene-dominated environment (mixed deciduous and pine forest in Alabama, SOAS 2013). Time series of gas/particle partitioning for ions consistent with tracers for isoprene oxidation such as methacrylic acid epoxide (MAE) and isoprene epoxydiol (IEPOX) and tracers for α-pinene oxidation such as pinic and pinonic acid will be presented. Gas/particle partitioning, represented as the fraction of each species in the particle-phase, Fp, was calculated for C1-C18 alkanoic acids and biogenic VOC oxidation tracers and compared to an absorptive partitioning model. These results are compared with those of two other instruments that can also quantify gas/particle partitioning with high time resolution: a Semivolatile Thermal Desorption Aerosol GC/MS (SV-TAG) and a Thermal Desorption Proton Transfer Time-of-Flight Mass Spectrometer (TD-PTRMS). Data from both environments were consistent with the values and trends predicted by the absorptive partitioning model for the tracer acids. However, for low carbon number alkanoic acids we report a higher fraction in the particle phase than predicted by the model. The Fp for the bulk-averaged acids and its relationship to the degree of oxidation and carbon number will also be presented. Temporal patterns and correlations with atmospheric conditions and composition will be explored for individual and bulk acids. We will discuss atmospheric implications of the gas/particle partitioning

  16. Laparoscopic gastric banding

    MedlinePlus

    ... gastric banding is not a "quick fix" for obesity. It will greatly change your lifestyle. You must ... panel on weight loss surgery: executive report update. Obesity . 2009;17:842-62. PMID: 19396063 www.ncbi. ...

  17. Gastric Sleeve Surgery

    MedlinePlus

    ... or "sleeve" out of the rest. The new, banana-shaped stomach is much smaller than the original ... of your stomach, leaving you with a smaller banana-shaped stomach called the gastric sleeve. Because it's ...

  18. Hereditary Diffuse Gastric Cancer

    MedlinePlus

    ... with the syndrome is recommended. What are the estimated cancer risks associated with HDGC? Not everyone who ... the lifetime risk for diffuse gastric cancer is estimated to be 70% to 80% for men and ...

  19. Gastric bypass surgery

    MedlinePlus

    ... your legs to help prevent blood clots from forming. You will receive shots of medicine to prevent ... diversion with duodenal switch Dumping syndrome References Buchwald H. Laparoscopic Roux-en-Y gastric bypass. In: Buchwald ...

  20. The effect of ionizing radiation on amino acids and bacterial spores in different geo- and cosmochemical environments

    NASA Astrophysics Data System (ADS)

    Kminek, Gerhard

    In this thesis I have investigated the impact of ionizing radiation from the environment on the stability of bacterial spores and amino acids. I measured the radiolysis constant of amino acids and the inactivation constant of bacterial spores. To put these results in the context of a natural setting, I have selected four different cases and calculated the radiation environment for meteorites, the Martian subsurface, terrestrial halite fluid inclusions, and fossil bones. Bacterial spores exhibit a remarkable resistance to adverse environments and are the best example for the long-term survival of life forms. On a molecular level, amino acids are of particular interest because of their importance in biochemistry and their stability in the environment. The significance of amino acids, however, goes back to a time before life existed. The exogenous delivery of amino acids by meteorites might have been essential to provide the required supply of organic molecules for the origin of life on the Earth. There is one common threat, however, to the preservation of amino acids and bacterial spores in all known terrestrial and extraterrestrial environments: ionizing radiation. Amino acids in meteorites are exposed to radiation from internal radioactivity and space radiation. I show that this radiation decomposes substantial amounts of amino acids over time, indicating a higher exogenous delivery of amino acids to the early Earth. The total radiodecomposition since the synthesis of amino acids is between 23 and 68%. Radiodecomposition induces a certain fractionation in favor of smaller amino acids. Fossil bones show a post-mortem uranium uptake. My results suggest a substantial radiodecomposition of amino acids on a 10 million year time scale. Age determination based on racemization of amino acids will be affected in fossil bones that are older than 1--30 million years. My results on the stability of bacterial spores in halite fluid inclusions and on Mars suggest that radiation

  1. Embrittlement of a Duplex Stainless Steel in Acidic Environment Under Applied Cathodic Potentials

    NASA Astrophysics Data System (ADS)

    Roychowdhury, S.; Kain, Vivekanand

    2008-10-01

    Hydrogen-induced degradation of mechanical properties of a duplex stainless steel in 0.1N H2SO4 solution has been studied under in situ cathodic charging conditions. Significant reductions in percentage of elongation, toughness, and time to failure were noticed due to the ingress of hydrogen into the material at various applied cathodic potentials in the range of -200 to -800 mV (SCE). Cleavage fractures were identified mainly in the ferritic phases. Crack growth was observed to be inhibited by the austenite phase. However, depending on the severity of the environment, both the ferrite and austenite phases could be embrittled. At less negative potentials, presence of surface film and low hydrogen fugacity seemed to control hydrogen ingress in the metal. Addition of thiosulfate to the acidic solution further degraded the mechanical properties of the steel at the applied cathodic potential.

  2. Resistance to acidic environments of caries-associated bacteria: Bifidobacterium dentium and Bifidobacterium longum.

    PubMed

    Nakajo, K; Takahashi, N; Beighton, D

    2010-01-01

    Oral Bifidobacteriaceae, Bifidobacterium dentium and Bifidobacterium longum, are known to be isolated together with mutans streptococci and lactobacilli from caries lesions, suggesting that these Bifidobacteriaceae are caries associated and acid resistant. This study aimed to investigate effects of acidification on B. dentium and B. longum, and to compare them with those on Streptococcus mutans, Streptococcus sanguinis and Lactobacillus paracasei. Effects of acidification, growth ability in a complex medium at a pH of 4.0-8.0, cell viability in 2-morpholinoethanesulfonic acid monohydrate (MES)-KOH buffer at pH 4.0, as well as stability of intracellular pH (pH(in)) at an extracellular pH of 3.5-8.0 estimated using a fluorescent dye, 5(6)-carboxyfluorescein diacetate N-succinimidyl ester in MES-KOH, 3-(N-morpholino)propanesulfonic acid-KOH or N,N-bis(2-hydroxyethyl)glycine-KOH buffer, were investigated. B. longum grew as well as Streptococcus strains over a wide pH range, whereas B. dentium grew best in the narrow pH range around neutral. The cell viability of B. dentium decreased significantly after 2 h of acidification at a pH of 4.0, but this was significantly less than that of the Streptococcus and Lactobacillus species, whereas B. longum maintained almost 100% viability. The pH(in) was close to the extracellular pH at pH of 5.5-7.5 in the Bifidobacterium and Streptococcus strains, while at a pH of <5.0, the pH(in) was higher than the extracellular pH in all the strains, but the pH(in) maintenance ability of Bifidobacterium strains was higher than that of the Streptococcus strains. The high survival rate and pH(in) maintenance ability of bifidobacteria comparable to that of S. mutans in the acidic environment may account for why bifidobacteria exist as stable species in acidic caries lesions together with mutans streptococci. PMID:20814202

  3. Gastric explosion induced by argon plasma coagulation and prevention strategies.

    PubMed

    Freiman, John Saul; Hampe, Toni

    2014-12-01

    We describe the occurrence of an iatrogenic explosion induced by argon plasma coagulation in a 70-year-old man undergoing gastroscopy. Combustible gases in the stomach may have been released by bacterial overgrowth as a result of partial gastric outlet obstruction (caused by a gastric tumor) and reduced acidity (from proton pump inhibitor therapy). We propose a stepwise process during upper endoscopy to prevent this devastating complication, comprising aspiration, preinsufflation with CO2, and then coagulation. PMID:25041867

  4. Effect of hyperprolactinaemia as induced by pituitary homografts under kidney capsule on gastric and duodenal ulcers in rats.

    PubMed

    Asad, M; Shewade, D G; Koumaravelou, K; Abraham, B K; Balasinor, N; Ramaswamy, S

    2001-11-01

    The effect of hyperprolactinaemia, induced by two or four pituitary homografts under the kidney capsule, on gastric and duodenal ulcers has been studied. The acute gastric ulcer models used were pylorus ligation, indometacin-induced and ethanol-induced gastric ulcers. Chronic gastric ulcers were induced using acetic acid and duodenal ulcers by mercaptamine hydrochloride. After pylorus ligation, there was an approximate 30-40% increase in gastric secretion, a significant increase in total acidity (P < 0.01) and in the ulcer index (P < 0.01) in rats bearing pituitary homografts under the kidney capsule when compared with the sham-operated control. Hyperprolactinaemia did not affect the formation of ethanol-induced gastric ulcers but showed a 40% reduction in the development of indometacin-induced gastric ulcers. It also produced a 20% increase in the ulcer index in acetic acid-induced chronic gastric ulcers and a 30% increase in ulcer area in mercaptamine-induced duodenal ulcers. Our results showed that hyperprolactinaemia induced gastric acid secretion and thereby aggravated gastric and duodenal ulcers in rats. Hyperprolactinaemia did not affect gastric cytoprotection. PMID:11732757

  5. Gastroprotective effect of minocycline in experimentally induced gastric ulcers in rats.

    PubMed

    Asmari, Abdulrahman Al; Omani, Saud Al; Otaibi, Malfi Al; Abdulaaly, Abdul-Aziz Al; Elfaki, Ibrahim; Yahya, Khalid Al; Arshaduddin, Mohammed

    2014-01-01

    Minocycline (MCN), a semi-synthetic tetracycline derivative possesses pleiotropic effects and provides protection against a number of disease models. However its effect on gastric ulcers has not been studied. The present investigation was undertaken, to study the gastro-protective potential of MCN in experimentally induced gastric ulcers in rats. MCN (10, 30, 100 mg/Kg) was tested for gastric secretion and antiulcer activity in different groups of Wistar rats. Gastric secretion and acidity studies were performed in pylorus ligated rats while indices of gastric ulcers were measured in ethanol (1 ml-100%) and indomethacin (30 mg/kg), induced gastric ulcers. Histological changes and the levels of gastric wall mucus, malondialdehyde (MDA), non-protein sulfhydryl (NP-SH), and myeloperoxidase (MPO), were used to assess ethanol induced gastric mucosal injuries. Exposure of rats to ulcerogens resulted in gastric mucosal injury and a significant increase in the indices of ulcer. MCN conferred a protective effect against ethanol, and indomethacin induced gastric mucosal injuries. Treatment with MCN, resulted in a significant decrease in the amount of gastric secretion, and total acidity and significantly (P<0.001), reduced the gastric lesions induced by ethanol and indomethacin. MCN also significantly attenuated the ethanol induced reduction in the levels of gastric wall mucus, and NP-SH (P<0.001). The histological changes and the increased MDA and MPO activity were also significantly (P<0.001) inhibited by MCN. Minocycline showed significant antiulcer and gastroprotective activity against experimentally induced gastric ulcers. The gastroprotective effects of minocycline may be due to its anti-secretory, antioxidant and anti inflammatory action. PMID:24753752

  6. Aripiprazole an atypical antipsychotic protects against ethanol induced gastric ulcers in rats

    PubMed Central

    Asmari, Abdulrahman Al; Arshaduddin, Mohammed; Elfaki, Ibrahim; Kadasah, Saeed; Robayan, Abdulrahman Al; Asmary, Saeed Al

    2014-01-01

    The present investigation was undertaken, to study the gastro-protective potential of aripiprazole (ARI) an atypical antipsychotic drug in ethanol induced gastric ulcers in rats. ARI (10, 30, 100 mg/kg) was tested for gastric secretion and antiulcer activity in different groups of male Sprague Dawley rats. Gastric secretion and acidity studies were performed in pylorus ligated rats while indices of gastric ulcers were measured in ethanol (1 ml-100%) induced gastric ulcers. Histological changes and the levels of gastric wall mucus, malondialdehyde (MDA), non-protein sulfhydryls (NP-SH), myeloperoxidase (MPO), and serotonin were used to assess ethanol induced gastric mucosal injuries. Exposure of rats to ethanol resulted in gastric mucosal injury and a high index of ulcer. Pretreatment with ARI significantly (P < 0.001), reduced the gastric lesions induced by ethanol and also resulted in a significant decrease in the gastric secretion, and total acidity in pylorus ligated rats. ARI also significantly attenuated the ethanol induced reduction in the levels of gastric wall mucus, and NP-SH (P < 0.001). The histological changes and the increased MDA and MPO activity were also significantly (P < 0.001) inhibited by ARI. Ethanol induced depletion in the levels of serotonin in the gastric tissue were also significantly restored by pretreatment with ARI (p < 0.001). ARI showed significant antiulcer and gastroprotective activity against ethanol induced gastric ulcers. The gastroprotective effects of ARI may be due to its anti-secretory, antioxidant and anti-inflammatory action and also due to the restoration of the depleted gastric serotonin levels. PMID:25232384

  7. Gastroprotective effect of minocycline in experimentally induced gastric ulcers in rats

    PubMed Central

    Asmari, Abdulrahman Al; Omani, Saud Al; Otaibi, Malfi Al; Abdulaaly, Abdul-Aziz Al; Elfaki, Ibrahim; Yahya, Khalid Al; Arshaduddin, Mohammed

    2014-01-01

    Minocycline (MCN), a semi-synthetic tetracycline derivative possesses pleiotropic effects and provides protection against a number of disease models. However its effect on gastric ulcers has not been studied. The present investigation was undertaken, to study the gastro-protective potential of MCN in experimentally induced gastric ulcers in rats. MCN (10, 30, 100 mg/Kg) was tested for gastric secretion and antiulcer activity in different groups of Wistar rats. Gastric secretion and acidity studies were performed in pylorus ligated rats while indices of gastric ulcers were measured in ethanol (1 ml-100%) and indomethacin (30 mg/kg), induced gastric ulcers. Histological changes and the levels of gastric wall mucus, malondialdehyde (MDA), non-protein sulfhydryl (NP-SH), and myeloperoxidase (MPO), were used to assess ethanol induced gastric mucosal injuries. Exposure of rats to ulcerogens resulted in gastric mucosal injury and a significant increase in the indices of ulcer. MCN conferred a protective effect against ethanol, and indomethacin induced gastric mucosal injuries. Treatment with MCN, resulted in a significant decrease in the amount of gastric secretion, and total acidity and significantly (P<0.001), reduced the gastric lesions induced by ethanol and indomethacin. MCN also significantly attenuated the ethanol induced reduction in the levels of gastric wall mucus, and NP-SH (P<0.001). The histological changes and the increased MDA and MPO activity were also significantly (P<0.001) inhibited by MCN. Minocycline showed significant antiulcer and gastroprotective activity against experimentally induced gastric ulcers. The gastroprotective effects of minocycline may be due to its anti-secretory, antioxidant and anti inflammatory action. PMID:24753752

  8. CT of Gastric Emergencies.

    PubMed

    Guniganti, Preethi; Bradenham, Courtney H; Raptis, Constantine; Menias, Christine O; Mellnick, Vincent M

    2015-01-01

    Abdominal pain, nausea, and vomiting are common presenting symptoms among adult patients seeking care in the emergency department, and, with the increased use of computed tomography (CT) to image patients with these complaints, radiologists will more frequently encounter a variety of emergent gastric pathologic conditions on CT studies. Familiarity with the CT appearance of emergent gastric conditions is important, as the clinical presentation is often nonspecific and the radiologist may be the first to recognize gastric disease as the cause of a patient's symptoms. Although endoscopy and barium fluoroscopy remain important tools for evaluating patients with suspected gastric disease in the outpatient setting, compared with CT these modalities enable less comprehensive evaluation of patients with nonspecific complaints and are less readily available in the acute setting. Endoscopy is also more invasive than CT and has greater potential risks. Although the mucosal detail of CT is relatively poor compared with barium fluoroscopy or endoscopy, CT can be used with the appropriate imaging protocols to identify inflammatory conditions of the stomach ranging from gastritis to peptic ulcer disease. In addition, CT can readily demonstrate the various complications of gastric disease, including perforation, obstruction, and hemorrhage, which may direct further clinical, endoscopic, or surgical management. We will review the normal anatomy of the stomach and discuss emergent gastric disease with a focus on the usual clinical presentation, typical imaging appearance, and differentiating features, as well as potential imaging pitfalls. PMID:26562229

  9. Coexistence of Lactic Acid Bacteria and Potential Spoilage Microbiota in a Dairy Processing Environment.

    PubMed

    Stellato, Giuseppina; De Filippis, Francesca; La Storia, Antonietta; Ercolini, Danilo

    2015-11-01

    Microbial contamination in food processing plants can play a fundamental role in food quality and safety. In this study, the microbiota in a dairy plant was studied by both 16S rRNA- and 26S rRNA-based culture-independent high-throughput amplicon sequencing. Environmental samples from surfaces and tools were studied along with the different types of cheese produced in the same plant. The microbiota of environmental swabs was very complex, including more than 200 operational taxonomic units with extremely variable relative abundances (0.01 to 99%) depending on the species and sample. A core microbiota shared by 70% of the samples indicated a coexistence of lactic acid bacteria with a remarkable level of Streptococcus thermophilus and possible spoilage-associated bacteria, including Pseudomonas, Acinetobacter, and Psychrobacter, with a relative abundance above 50%. The most abundant yeasts were Kluyveromyces marxianus, Yamadazyma triangularis, Trichosporon faecale, and Debaryomyces hansenii. Beta-diversity analyses showed a clear separation of environmental and cheese samples based on both yeast and bacterial community structure. In addition, predicted metagenomes also indicated differential distribution of metabolic pathways between the two categories of samples. Cooccurrence and coexclusion pattern analyses indicated that the occurrence of potential spoilers was excluded by lactic acid bacteria. In addition, their persistence in the environment can be helpful to counter the development of potential spoilers that may contaminate the cheeses, with possible negative effects on their microbiological quality. PMID:26341209

  10. Quantitative detection of syntrophic fatty acid-degrading bacterial communities in methanogenic environments.

    PubMed

    Mathai, Prince P; Zitomer, Daniel H; Maki, James S

    2015-06-01

    In methanogenic habitats, volatile fatty acids (VFA), such as propionate and butyrate, are major intermediates in organic matter degradation. VFA are further metabolized to H(2), acetate and CO(2) by syntrophic fatty acid-degrading bacteria (SFAB) in association with methanogenic archaea. Despite their indispensable role in VFA degradation, little is known about SFAB abundance and their environmental distribution. To facilitate ecological studies, we developed four novel genus-specific quantitative PCR (qPCR) assays, with primer sets targeting known SFAB: Syntrophobacter, Smithella, Pelotomaculum and Syntrophomonas. Primer set specificity was confirmed using in silico and experimental (target controls, clone libraries and melt-curve analysis) approaches. These qPCR assays were applied to quantify SFAB in a variety of mesophilic methanogenic habitats, including a laboratory propionate enrichment culture, pilot- and full-scale anaerobic reactors, cow rumen, horse faeces, an experimental rice paddy soil, a bog stream and swamp sediments. The highest SFAB 16S rRNA gene copy numbers were found in the propionate enrichment culture and anaerobic reactors, followed by the bog stream and swamp sediment samples. In addition, it was observed that SFAB and methanogen abundance varied with reactor configuration and substrate identity. To our knowledge, this research represents the first comprehensive study to quantify SFAB in methanogenic habitats using qPCR-based methods. These molecular tools will help investigators better understand syntrophic microbial communities in engineered and natural environments. PMID:25814038

  11. Fatty acid content and profile of the aerial microalga Coccomyxa sp. isolated from dry environments.

    PubMed

    Abe, Katsuya; Ishiwatari, Takehiro; Wakamatsu, Michihiro; Aburai, Nobuhiro

    2014-11-01

    Aerial algae are considered to be highly tolerant of and adaptable to severe conditions including radiation, desiccation, high temperatures, and nutrient deficiency, compared with those from aquatic habitats. There are considerable variations in the fatty acid (FA) composition of aerial microalgae from dry environments. A new species with a high lipid level was found on concrete surfaces and was identified as Coccomyxa sp. KGU-D001 (Trebouxiophyceae). This study characterized its FA content and profile in a bath culture. The alga showed a constant specific growth rate (0.26 day(-1)) ranging in light intensity from 20 to 80 μmol photons m(-2) s(-1). The algal cells started to form oil bodies in the early stationary phase of growth, and oil bodies occupied most of the cells during the late stationary phase when the cells accumulated 27 % total fatty acids (TFA). The process of lipid body formation accumulating large amounts of triacylglycerols (TAG) appeared to be very unusual in response to stress conditions persisting for a relatively long culture time (50 days). This study could indicate that aerial microalgae will be a candidate for biodiesel production when a new cultivation method is developed using extreme stresses such as nutritional deficiency and/or desiccation. PMID:25146196

  12. Regulation of acyltransferase activity in immature maize embryos by abscisic acid and the osmotic environment.

    PubMed Central

    Pacheco-Moisés, F; Valencia-Turcotte, L; Altuzar-Martínez, M; Rodríguez-Sotres, R

    1997-01-01

    Maize (Zes mays L.) embryos, isolated from the developing seed and incubated in dilute buffer, show reduced triacylglycerol (TAG) synthesis, and accumulation stops after 24 h. Synthesis and accumulation can be maintained at high levels if the incubation medium contains abscisic acid (ABA) and/or a high osmotic concentration. Radiolabeled free fatty acids accumulate at higher levels in embryos that contain less TAG, and acetyl coenzyme A carboxylase activity remains essentially unchanged under all of the conditions tested. In contrast, the activities of the acyltransferases required for TAG synthesis remain high only in embryos incubated with ABA and/or a high osmotic concentration. Dose-response curves showed that 4 microM of ABA or mannitol at -1.0 MPa elicits a full response; both values are within the range considered to be physiological. The TAG synthesis capacity and discylglycerol acyltransferase activity lost by pretreatment of the embryos can be restored by re-exposure to ABA or high osmoticum. Germination is not involved because isolated scutellum halves showed the same changes in enzyme activity found in the whole embryo but did not germinate. Our results provide direct evidence for the regulation of TAG-synthesizing activities in maize embryos by ABA and the osmotic potential of the environment. PMID:9232885

  13. Degradation of articular cartilage keratan sulphates using hydrazinolysis and nitrous acid. Environment of fucose residues.

    PubMed Central

    Brown, G M; Huckerby, T N; Morris, H G; Nieduszynski, I A

    1992-01-01

    Alkaline borohydride-reduced keratan sulphate (KS) chains from bovine articular cartilage (6-8-year-old animals) were fragmented by an anhydrous hydrazine/nitrous acid procedure, previously used on KS by Hopwood & Elliott to isolate the major disaccharides from the poly-N-acetyl-lactosamine repeat sequence [Hopwood & Elliott (1983) Carbohydr. Res. 117, 263-274]. The resulting oligosaccharides were reduced with NaB3H4 or NaBH4 and subjected to ion-exchange chromatography on a Nucleosil 5SB column. In addition to the major disaccharides, two fucose-containing oligosaccharides were examined by high-field 1H n.m.r. spectroscopy, and shown to have the following structures (where AnManOH is 2,5-anhydro-D-mannitol): [formula: see text] It is evident that the presence of fucose protects the N-acetylglucosamine residue from de-N-acetylation, and therefore fragments are produced which preserve the immediate environment of the fucose residue. It may be of biosynthetic significance that these two oligosaccharides contain an unsulphated galactose on the non-reducing side of the fucose residue. The hydrazine/nitrous acid/NaB3H4 method followed by h.p.l.c. provides a sensitive fingerprinting technique for the assay of KS composition and sub-populations. PMID:1520275

  14. Coexistence of Lactic Acid Bacteria and Potential Spoilage Microbiota in a Dairy Processing Environment

    PubMed Central

    Stellato, Giuseppina; De Filippis, Francesca; La Storia, Antonietta

    2015-01-01

    Microbial contamination in food processing plants can play a fundamental role in food quality and safety. In this study, the microbiota in a dairy plant was studied by both 16S rRNA- and 26S rRNA-based culture-independent high-throughput amplicon sequencing. Environmental samples from surfaces and tools were studied along with the different types of cheese produced in the same plant. The microbiota of environmental swabs was very complex, including more than 200 operational taxonomic units with extremely variable relative abundances (0.01 to 99%) depending on the species and sample. A core microbiota shared by 70% of the samples indicated a coexistence of lactic acid bacteria with a remarkable level of Streptococcus thermophilus and possible spoilage-associated bacteria, including Pseudomonas, Acinetobacter, and Psychrobacter, with a relative abundance above 50%. The most abundant yeasts were Kluyveromyces marxianus, Yamadazyma triangularis, Trichosporon faecale, and Debaryomyces hansenii. Beta-diversity analyses showed a clear separation of environmental and cheese samples based on both yeast and bacterial community structure. In addition, predicted metagenomes also indicated differential distribution of metabolic pathways between the two categories of samples. Cooccurrence and coexclusion pattern analyses indicated that the occurrence of potential spoilers was excluded by lactic acid bacteria. In addition, their persistence in the environment can be helpful to counter the development of potential spoilers that may contaminate the cheeses, with possible negative effects on their microbiological quality. PMID:26341209

  15. Relation between gastric emptying rate and rate of intraluminal lipolysis.

    PubMed

    Maes, B D; Ghoos, Y F; Geypens, B J; Hiele, M I; Rutgeerts, P J

    1996-01-01

    The variable gastric emptying rate of a test meal is one of the major problems in evaluating accurately gastrointestinal physiological functions beyond the stomach. The aim of this study was to evaluate the effect of the gastric emptying rate on the rate of intraluminal lipolysis. Thirty four subjects without pancreatic disease (21 with a normal gastric emptying and 13 with a known slow gastric emptying) and 14 subjects with pancreatic disease (four without and 10 with pancreatic insufficiency) were studied using a dual labelled breath test. The test meal consisted of one egg, 60 grams of white bread, 10 grams of margarine, and 150 ml of water (350 kcal). The egg yolk was labelled with 91 mg of 13C-octanoic acid, the margarine was labelled with 296 kBq of distearyl-2-14C-octanoyl-glycerol. Breath samples were taken every 15 minutes during six hours and analysed for 13CO2 and 14CO2 content. The gastric emptying rate of the meal was evaluated by the gastric emptying coefficient, the half emptying time, and the lag phase; the rate of intraluminal lipolysis was evaluated by the six hours cumulative 14CO2 excretion. Despite a clear distinction in the rate of intraluminal lipolysis, no difference could be detected in gastric emptying rate of the test meal between subjects without and with pancreatic disease. In subjects with pancreatic insufficiency, intraluminal hydrolysis was the rate limiting process in fat assimilation; in patients without pancreatic insufficiency, however, gastric emptying could be rate limiting. Therefore, patients with known slow gastric emptying, displayed a significantly decreased rate of intraluminal lipolysis compared with normal controls. This decrease could be corrected for accurately using a correction factor based on the gastric emptying coefficient. In conclusion, the combined 13C-octanoic acid and 14C-mixed triglyceride breath test permits the measurement of gastric emptying rate and intraluminal lipolysis simultaneously in a minimally

  16. Thermolysis of fluoropolymers as a potential source of halogenated organic acids in the environment.

    PubMed

    Ellis, D A; Mabury, S A; Martin, J W; Muir, D C

    2001-07-19

    Following the introduction of hydrochlorofluorocarbon (HCFCs) and hydrofluorocarbon (HFCs) gases as replacements for the ozone-destroying chlorofluorocarbons (CFCs), it has been discovered that HCFCs/HFCs can degrade in the atmosphere to produce trifluoroacetic acid, a compound with no known loss mechanisms in the environment, and higher concentrations in natural waters have been shown to be mildly phytotoxic. Present environmental levels of trifluooracetic acid are not accounted by HCFC/HFC degradation alone. Here we report that thermolysis of fluorinated polymers, such as the commercial polymers Teflon and Kel-F, can also produce trifluoroacetate and the similar compound chlorodifluoroacetate. This can occur either directly, or indirectly via products that are known to degrade to these haloacetates in the atmosphere. The environmental significance of these findings is confirmed by modelling, which indicates that the thermolysis of fluoropolymers in industrial and consumer high-temperature applications (ovens, non-stick cooking utensils and combustion engines) is likely to be a significant source of trifluoroacetate in urban rain water ( approximately 25 ng l-1, as estimated for Toronto). Thermolysis also leads to longer chain polyfluoro- and/or polychlorofluoro- (C3-C14) carboxylic acids which may be equally persistent. Some of these products have recently been linked with possible adverse health and environmental impacts and are being phased out of the US market. Furthermore, we detected CFCs and fluorocarbons-groups that can destroy ozone and act as greenhouse gases, respectively-among the other thermal degradation products, suggesting that continued use of fluoropolymers may also exacerbate stratospheric ozone-depletion and global warming. PMID:11460160

  17. Localized corrosion of high performance metal alloys in an acid/salt environment

    NASA Technical Reports Server (NTRS)

    Macdowell, L. G.; Ontiveros, C.

    1991-01-01

    Various vacuum jacketed cryogenic supply lines at the Space Shuttle launch site at Kennedy Space Center use convoluted flexible expansion joints. The atmosphere at the launch site has a very high salt content, and during a launch, fuel combustion products include hydrochloric acid. This extremely corrosive environment has caused pitting corrosion failure in the thin walled 304L stainless steel flex hoses. A search was done to find a more corrosion resistant replacement material. The study focussed on 19 metal alloys. Tests which were performed include electrochemical corrosion testing, accelerated corrosion testing in a salt fog chamber, and long term exposure at a beach corrosion testing site. Based on the results of these tests, several nickel based alloys were found to have very high resistance to this corrosive environment. Also, there was excellent agreement between the electrochemical tests and the actual beach exposure tests. This suggests that electrochemical testing may be useful for narrowing the field of potential candidate alloys before subjecting samples to long term beach exposure.

  18. Gastric Adenocarcinoma Presenting with Gastric Outlet Obstruction in a Child

    PubMed Central

    Al-Hussaini, Abdulrahman; AlGhamdi, Salem; Al-Kasim, Fawaz; Habib, Zakaria; Ourfali, Nouri

    2014-01-01

    Gastric carcinoma is extremely rare in children representing only 0.05% of all gastrointestinal malignancies. Here, we report the first pediatric case of gastric cancer presenting with gastric outlet obstruction. Upper endoscopy revealed a markedly thickened antral mucosa occluding the pylorus and a clean base ulcer 1.5 cm × 2 cm at the lesser curvature of the stomach. The narrowed antrum and pylorus underwent balloon dilation, and biopsy from the antrum showed evidence of Helicobacter pylori gastritis. The biopsy taken from the edge of the gastric ulcer demonstrated signet-ring-cell type infiltrate consistent with gastric adenocarcinoma. At laparotomy, there were metastases to the liver, head of pancreas, and mesenteric lymph nodes. Therefore, the gastric carcinoma was deemed unresectable. The patient died few months after initiation of chemotherapy due to advanced malignancy. In conclusion, this case report underscores the possibility of gastric adenocarcinoma occurring in children and presenting with gastric outlet obstruction. PMID:24707411

  19. Ghrelin Is an Essential Factor for Motilin-Induced Gastric Contraction in Suncus murinus.

    PubMed

    Kuroda, Kayuri; Hequing, Huang; Mondal, Anupom; Yoshimura, Makoto; Ito, Kazuma; Mikami, Takashi; Takemi, Shota; Jogahara, Takamichi; Sakata, Ichiro; Sakai, Takafumi

    2015-12-01

    Motilin was discovered in the 1970s as the most important hormone for stimulating strong gastric contractions; however, the mechanisms by which motilin causes gastric contraction are not clearly understood. Here, we determined the coordinated action of motilin and ghrelin on gastric motility during fasted and postprandial contractions by using house musk shrew (Suncus murinus; order: Insectivora, suncus named as the laboratory strain). Motilin-induced gastric contractions at phases I and II of the migrating motor complex were inhibited by pretreatment with (D-Lys(3))-GHRP-6 (6 mg/kg/h), a ghrelin receptor antagonist. Administration of the motilin receptor antagonist MA-2029 (0.1 mg/kg) and/or (D-Lys(3))-GHRP-6 (0.6 mg/kg) at the peak of phase III abolished the spontaneous gastric phase III contractions in vivo. Motilin did not stimulate gastric contractions in the postprandial state. However, in the presence of a low dose of ghrelin, motilin evoked phase III-like gastric contractions even in the postprandial state, and postprandial gastric emptying was accelerated. In addition, pretreatment with (D-Lys(3))-GHRP-6 blocked the motilin-induced gastric contraction in vitro and in vivo, and a γ-aminobutyric acid (GABA) antagonist reversed this block in gastric contraction. These results indicate that blockade of the GABAergic pathway by ghrelin is essential for motilin-induced gastric contraction. PMID:26441238

  20. Effects of Aloe vera and sucralfate on gastric microcirculatory changes, cytokine levels and gastric ulcer healing in rats

    PubMed Central

    Eamlamnam, Kallaya; Patumraj, Suthiluk; Visedopas, Naruemon; Thong-Ngam, Duangporn

    2006-01-01

    AIM: To compare the effects of Aloe vera and sucralfate on gastric microcirculatory changes, cytokine levels and gastric ulcer healing. METHODS: Male Spraque-Dawley rats (n= 48) were divided into four groups. Group1 served as control group, group 2 as gastric ulcer group without treatment, groups 3 and 4 as gastric ulcer treatment groups with sucralfate and Aloe vera. The rats from each group were divided into 2 subgroups for study of leukocyte adherence, TNF-α and IL-10 levels and gastric ulcer healing on days 1 and 8 after induction of gastric ulcer by 20 % acetic acid. RESULTS: On day 1 after induction of gastric ulcer, the leukocyte adherence in postcapillary venule was significantly (P< 0.05) increased in the ulcer groups when compared to the control group. The level of TNF-α was elevated and the level of IL-10 was reduced. In the ulcer groups treated with sucralfate and Aloe vera, leukocyte adherence was reduced in postcapillary venule. The level of IL-10 was elevated, but the level of TNF-α had no significant difference. On day 8, the leukocyte adherence in postcapillary venule and the level of TNF-α were still increased and the level of IL-10 was reduced in the ulcer group without treatment. The ulcer treated with sucralfate and Aloe vera had lower leukocyte adherence in postcapillary venule and TNF-α level. The level of IL-10 was still elevated compared to the ulcer group without treatment. Furthermore, histopathological examination of stomach on days 1 and 8 after induction of gastric ulcer showed that gastric tissue was damaged with inflammation. In the ulcer groups treated with sucralfate and Aloe vera on days 1 and 8, gastric inflammation was reduced, epithelial cell proliferation was enhanced and gastric glands became elongated. The ulcer sizes were also reduced compared to the ulcer group without treatment. CONCLUSION: Administration of 20 % acetic acid can induce gastric inflammation, increase leukocyte adherence in postcapillary venule

  1. Increased gastric PCO2 during exercise is indicative of gastric ischaemia: a tonometric study

    PubMed Central

    Kolkman, J; Groeneveld, A; van der Berg, F G; Rauwerda, J; Meuwissen, S

    1999-01-01

    Background—Diagnosis of gastric ischaemia is difficult and angiography is an invasive procedure. Angiographic findings may not correlate with clinical importance. 
Aims—To investigate whether tonometric measurement of intragastric PCO2 during exercise can be used to detect clinically important gastric ischaemia. 
Methods—Fourteen patients with unexplained abdominal pain or weight loss were studied. Splanchnic angiography served as the gold standard. Three patients were studied again after a revascularisation procedure. Gastric PCO2 was measured from a nasogastric tonometer, with 10 minute dwell times, and after acid suppression. Gastric and capillary PCO2 were measured before, during, and after submaximal exercise of 10 minutes duration. 
Results—Seven patients had normal angiograms; seven had more than 50% stenosis in the coeliac (n=7) or superior mesenteric artery (n=4). Normal subjects showed no changes in tonometry. In patients with stenoses, the median intragastric PCO2 (PiCO2) at rest was 5.2 kPa (range 4.8-11.2) and rose to 6.4 kPa (range 5.7-15.7) at peak exercise; the median intragastric blood PCO2 gradient increased from 0.0 kPa (range −0.8 to 5.9) to 1.7 kPa (range 0.9 to 10.3; p<0.01). Only two subjects had abnormal tonometry at rest; all had supernormal values at peak exercise. The PCO2 gradient correlated with clinical and gastroscopic severity; in patients reexamined after revascularisation (n=3), exercise tonometry returned to normal. 
Conclusion—Gastric tonometry during exercise is a promising non-invasive tool for diagnosing and grading gastrointestinal ischaemia and evaluating the results of revascularisation surgery for symptomatic gastric ischaemia. 

 Keywords: gastric ischaemia; tonometry; carbon dioxide; exercise test PMID:9895373

  2. Assessment of Epstein-Barr virus nucleic acids in gastric but not in breast cancer by next-generation sequencing of pooled Mexican samples.

    PubMed

    Fuentes-Pananá, Ezequiel M; Larios-Serrato, Violeta; Méndez-Tenorio, Alfonso; Morales-Sánchez, Abigail; Arias, Carlos F; Torres, Javier

    2016-03-01

    Gastric (GC) and breast (BrC) cancer are two of the most common and deadly tumours. Different lines of evidence suggest a possible causative role of viral infections for both GC and BrC. Wide genome sequencing (WGS) technologies allow searching for viral agents in tissues of patients with cancer. These technologies have already contributed to establish virus-cancer associations as well as to discovery new tumour viruses. The objective of this study was to document possible associations of viral infection with GC and BrC in Mexican patients. In order to gain idea about cost effective conditions of experimental sequencing, we first carried out an in silico simulation of WGS. The next-generation-platform IlluminaGallx was then used to sequence GC and BrC tumour samples. While we did not find viral sequences in tissues from BrC patients, multiple reads matching Epstein-Barr virus (EBV) sequences were found in GC tissues. An end-point polymerase chain reaction confirmed an enrichment of EBV sequences in one of the GC samples sequenced, validating the next-generation sequencing-bioinformatics pipeline. PMID:26910355

  3. Assessment of Epstein-Barr virus nucleic acids in gastric but not in breast cancer by next-generation sequencing of pooled Mexican samples

    PubMed Central

    Fuentes-Pananá, Ezequiel M; Larios-Serrato, Violeta; Méndez-Tenorio, Alfonso; Morales-Sánchez, Abigail; Arias, Carlos F; Torres, Javier

    2016-01-01

    Gastric (GC) and breast (BrC) cancer are two of the most common and deadly tumours. Different lines of evidence suggest a possible causative role of viral infections for both GC and BrC. Wide genome sequencing (WGS) technologies allow searching for viral agents in tissues of patients with cancer. These technologies have already contributed to establish virus-cancer associations as well as to discovery new tumour viruses. The objective of this study was to document possible associations of viral infection with GC and BrC in Mexican patients. In order to gain idea about cost effective conditions of experimental sequencing, we first carried out an in silico simulation of WGS. The next-generation-platform IlluminaGallx was then used to sequence GC and BrC tumour samples. While we did not find viral sequences in tissues from BrC patients, multiple reads matching Epstein-Barr virus (EBV) sequences were found in GC tissues. An end-point polymerase chain reaction confirmed an enrichment of EBV sequences in one of the GC samples sequenced, validating the next-generation sequencing-bioinformatics pipeline. PMID:26910355

  4. Microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility

    PubMed Central

    Osorio, Héctor; Martínez, Verónica; Nieto, Pamela A; Holmes, David S; Quatrini, Raquel

    2008-01-01

    Background Iron is an essential nutrient but can be toxic at high intracellular concentrations and organisms have evolved tightly regulated mechanisms for iron uptake and homeostasis. Information on iron management mechanisms is available for organisms living at circumneutral pH. However, very little is known about how acidophilic bacteria, especially those used for industrial copper bioleaching, cope with environmental iron loads that can be 1018 times the concentration found in pH neutral environments. This study was motivated by the need to fill this lacuna in knowledge. An understanding of how microorganisms thrive in acidic ecosystems with high iron loads requires a comprehensive investigation of the strategies to acquire iron and to coordinate this acquisition with utilization, storage and oxidation of iron through metal responsive regulation. In silico prediction of iron management genes and Fur regulation was carried out for three Acidithiobacilli: Acidithiobacillus ferrooxidans (iron and sulfur oxidizer) A. thiooxidans and A. caldus (sulfur oxidizers) that can live between pH 1 and pH 5 and for three strict iron oxidizers of the Leptospirillum genus that live at pH 1 or below. Results Acidithiobacilli have predicted FeoB-like Fe(II) and Nramp-like Fe(II)-Mn(II) transporters. They also have 14 different TonB dependent ferri-siderophore transporters of diverse siderophore affinity, although they do not produce classical siderophores. Instead they have predicted novel mechanisms for dicitrate synthesis and possibly also for phosphate-chelation mediated iron uptake. It is hypothesized that the unexpectedly large number and diversity of Fe(III)-uptake systems confers versatility to this group of acidophiles, especially in higher pH environments (pH 4–5) where soluble iron may not be abundant. In contrast, Leptospirilla have only a FtrI-Fet3P-like permease and three TonB dependent ferri-dicitrate siderophore systems. This paucity of iron uptake systems could

  5. Role of Butea Frondosa in Ameliorating Gastric Markers in Induced Gastric Lesions of Rats

    PubMed Central

    Banji, D.; Banji, Otilia J. F.; Singh, Meenu; Annamalai, A. R.

    2011-01-01

    The study evaluated the ability of the alcohol extract of Butea frondosa to protect the gastro-duodenal lining from injury inflicted by acetic acid and pyloric ligation in rats. The induced gastric lesions lead to the generation of alkaline phosphatase and pepsin, which serve as important markers of gastric damage. Alcohol extract of Butea frondosa was administered in doses of 10, 100, 300 and 500 mg/kg as a single schedule and for the time dependent studies in a dose of 100 mg/kg for 7, 14, 21 and 28 days, respectively. Our studies reveal a decline in the formation of alkaline phosphatase and pepsin with 300 and 500 mg/kg of the extract and following treatment for 21 and 28 days, respectively. Extract of Butea frondosa produces significant diminution in the formation of gastric markers implying possible gastro-protective action. PMID:22457555

  6. General Information about Gastric Cancer

    MedlinePlus

    ... Research Gastric Cancer Treatment (PDQ®)–Patient Version General Information About Gastric Cancer Go to Health Professional Version ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

  7. Mycogenic Mn(II) oxidation promotes remediation of acid mine drainage and other anthropogenically impacted environments

    NASA Astrophysics Data System (ADS)

    Santelli, C. M.; Chaput, D.; Hansel, C. M.; Burgos, W. D.

    2014-12-01

    Manganese is a pollutant in worldwide environments contaminated with metals and organics, such as acid mine drainage (AMD), freshwater ponds, and agricultural waste storage sites. Microorganisms contribute to the removal of dissolved Mn compounds in the environment by promoting Mn(II) oxidation reactions. The oxidation of Mn(II) results in the precipitation of sparingly soluble Mn(IV) oxide minerals, effectively removing the metal from the aqueous milieu (e.g., groundwater or wastewater streams). In recent years, our research has identified a diversity of Mn(II)-oxidizing fungi inhabiting these polluted environments, however their overall contribution to the remediation process in situ remains poorly understood. Here we present results of culture-based and Next Generation Sequencing (NGS) studies in AMD treatment systems actively remediating Mn and other metals where we profile the bacterial, fungal, algal and archaeal communities to determine the overall community diversity and to establish the relative abundance of known Mn(II) oxidizers. A variety of treatment systems with varying Mn-removal efficiencies were sampled to understand the relationship between remediation efficiency and microbial community composition and activity. Targeted-amplicon sequencing of DNA and RNA of the 16S rRNA genes (bacteria and archaea), 23S rRNA genes (algae) and ITS region (fungi) was performed using both 454 pyrosequencing and Illumina platforms. Results showed that only the fungal taxonomic profiles significantly differed between sites that removed the majority of influent Mn and those that did not. Specifically, Ascomycota (which include known Mn(II) oxidizers isolated from these treatment systems) dominated greater efficiency systems whereas less efficient systems were dominated by Basidiomycota. Furthermore, known Mn(II) oxidizers accounted for only a minor proportion of bacterial sequences but a far greater proportion of fungal sequences. These culture-independent studies lend

  8. Involvement of the G-protein-coupled receptor 4 in RANKL expression by osteoblasts in an acidic environment.

    PubMed

    Okito, Asuka; Nakahama, Ken-Ichi; Akiyama, Masako; Ono, Takashi; Morita, Ikuo

    2015-03-01

    Osteoclast activity is enhanced in acidic environments following systemic or local inflammation. However, the regulatory mechanism of receptor activator of NF-κB ligand (RANKL) expression in osteoblasts under acidic conditions is not fully understood. In the present paper, we detected the mRNA expression of the G-protein-coupled receptor (GPR) proton sensors GPR4 and GPR65 (T-cell death-associated gene 8, TDAG8), in osteoblasts. RANKL expression and the cyclic AMP (cAMP) level in osteoblasts were up-regulated under acidic culture conditions. Acidosis-induced up-regulation of RANKL was abolished by the protein kinase A inhibitor H89. To clarify the role of GPR4 in RANKL expression, GPR4 gain and loss of function experiments were performed. Gene knockdown and forced expression of GPR4 caused reduction and induction of RANKL expression, respectively. These results suggested that, at least in part, RANKL expression by osteoblasts in an acidic environment was mediated by cAMP/PKA signaling resulting from GPR4 activation. A comprehensive microarray analysis of gene expression of osteoblasts revealed that, under acidic conditions, the phenotype of osteoblasts was that of an osteoclast supporting cell rather than that of a mineralizing cell. These findings will contribute to a molecular understanding of bone disruption in an acidic environment. PMID:25668130

  9. Gastric Antral Vascular Ectasia in Systemic Sclerosis

    PubMed Central

    Johnson, Jill; Derk, Chris T.

    2011-01-01

    Gastric antral vascular ectasia is a not so well-understood, and more rare, gastrointestinal manifestation of Systemic Sclerosis which can lead to chronic anemia. A high suspicion and better understanding of this rare manifestation is needed for early detection and treatment. Therapeutic regiments include iron supplementation with acid suppressive therapy, while endoscopic intervention has been shown to be successful in most cases, with gastrectomy or antrectomy rarely needed. PMID:22121374

  10. GASTRIC MOTOR DISTURBANCES IN PATIENTS WITH IDIOPATHIC RAPID GASTRIC EMPTYING

    PubMed Central

    Bharucha, Adil E.; Manduca, Armando; Lake, David S.; Fidler, Jeff; Edwards, Phillip; Grimm, Roger C.; Zinsmeister, Alan R.; Riederer, Stephen J.

    2011-01-01

    Background and Aims The mechanisms of “idiopathic” rapid gastric emptying, which is associated with functional dyspepsia and functional diarrhea, are not understood. Our hypotheses were that increased gastric motility and reduced postprandial gastric accommodation contribute to rapid gastric emptying. Methods Fasting and postprandial (300kCal nutrient meal) gastric volumes were measured by magnetic resonance imaging (MRI) in 20 healthy people and 17 with functional dyspepsia; 7 had normal and 10 had rapid gastric emptying. In 17 healthy people and patients, contractility was analyzed by spectral analysis of a time-series of gastric cross-sectional areas. Logistic regression models analyzed whether contractile parameters, fasting volume, and postprandial volume change could discriminate between health and patients with normal or rapid gastric emptying. Results While upper gastrointestinal symptoms were comparable, patients with rapid emptying had a higher (p = 0.002) body mass index (BMI) than normal gastric emptying. MRI visualized propagating contractions at ~ 3 cpm in healthy people and patients. Compared to controls (0.16 ± 0.02, Mean ± SEM), the amplitude of gastric contractions in the entire stomach was higher (OR 4.1, 95% CI 1.2–14.0) in patients with rapid (0.24 ± 0.03) but not normal gastric emptying (0.10 ± 0.03). Similar differences were observed in the distal stomach. However, the propagation velocity, fasting gastric volume, and the postprandial volume change were not significantly different between patients and controls. Conclusions MRI provides a noninvasive and refined assessment of gastric volumes and contractility in humans. Increased gastric contractility may contribute to rapid gastric emptying in functional dyspepsia. PMID:21470342

  11. Geological record of an acidic environment driven by iron hydrochemistry: The Tinto River system

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Rodriguez, Nuria; Gómez, Felipe; Amils, Ricardo

    2003-07-01

    The existence of possible hematitic strata on the surface of Mars demands a search for terrestrial analogues formed in unusual environments. This will help us to recognize and interpret environmental and, perhaps, biological signatures preserved in Mars' hematites. Such an analogue would allow us to establish valid reference systems based on geomicrobial and biogeochemical signatures. Two different aspects place the Tinto River inside the boundaries of a natural extreme system: its high level of biological diversity and the presence of fluvial rocks formed in the same acidic conditions as in the modern system, which could predate the Tertiary. Study of both the modern system and the ancient system is necessary to understand the formation of biosignatures. A chemolithotrophic community that biooxidizes the Iberian Pyritic Belt, acidifying water (pH between 0.9 and 3.0) and favoring high concentrations of ferric iron in solution (up to 20 g.L-1), maintains this iron-driven system. In spite of these extreme conditions, high microbial diversity was found. Its acidic bacteria, archaea, and eukarya constitute a complex community supported by algal biomass in highly stable hydrochemical conditions, which are achieved through iron buffering. The pH is maintained at constant low levels even at very high water dilution. In these conditions, iron minerals as oxyhydroxides, hydroxides, and sulfates are formed. The modern and recent parageneses contrast with the ancient Tinto River terrace mineral associations, which show dehydrated and desulfated iron oxides. If this dehydration process is considered, these Tinto River ironstones may be a key for knowing some aquatic habitats, which may have hosted a part of the early Mars biosphere.

  12. A Combination of Amino Acids and Caffeine Enhances Sprint Running Capacity in a Hot, Hypoxic Environment.

    PubMed

    Eaton, Tom R; Potter, Aaron; Billaut, François; Panchuk, Derek; Pyne, David B; Gore, Christopher J; Chen, Ting-Ting; McQuade, Leon; Stepto, Nigel K

    2016-02-01

    Heat and hypoxia exacerbate central nervous system (CNS) fatigue. We therefore investigated whether essential amino acid (EAA) and caffeine ingestion attenuates CNS fatigue in a simulated team sport-specific running protocol in a hot, hypoxic environment. Subelite male team sport athletes (n = 8) performed a repeat sprint running protocol on a nonmotorized treadmill in an extreme environment on 4 separate occasions. Participants ingested one of four supplements: a double placebo, 3 mg.kg-1 body mass of caffeine + placebo, 2 x 7 g EAA (Musashi Create)+placebo, or caffeine + EAA before each exercise session using a randomized, double-blind crossover design. Electromyography (EMG) activity and quadriceps evoked responses to magnetic stimulation were assessed from the dominant leg at preexercise, halftime, and postexercise. Central activation ratio (CAR) was used to quantify completeness of quadriceps activation. Oxygenation of the prefrontal cortex was measured via near-infrared spectroscopy. Mean sprint work was higher (M = 174 J, 95% CI [23, 324], p < .05, d = 0.30; effect size, likely beneficial) in the caffeine + EAA condition versus EAAs alone. The decline in EMG activity was less (M = 13%, 95% CI [0, 26]; p < .01, d = 0.58, likely beneficial) in caffeine + EAA versus EAA alone. Similarly, the pre- to postexercise decrement in CAR was significantly less (M = -2.7%, 95% CI [0.4, 5.4]; p < .05, d = 0.50, likely beneficial) when caffeine + EAA were ingested compared with placebo. Cerebral oxygenation was lower (M = -5.6%, 95% CI [1.0, 10.1]; p < .01, d = 0.60, very likely beneficial) in the caffeine + EAA condition compared with LNAA alone. Co-ingestion of caffeine and EAA appears to maintain muscle activation and central drive, with a small improvement in running performance. PMID:26248498

  13. Naphthenic acids degradation and toxicity mitigation in tailings wastewater systems and aquatic environments: a review.

    PubMed

    Kannel, Prakash R; Gan, Thian Y

    2012-01-01

    Naphthenic acids, NAs (classical formula C(n)H(2n+z)O(2), where n is the carbon numbers, z represents zero or negative even integers), found in oil sands process waters (OSPWs), are toxic to aquatic environments depending upon several factors such as pH, salinity, molecular size and chemical structure of NAs. Among various available methods, biodegradation seems to be generally the most cost-effective method for decreasing concentrations of NAs (n ≤ 21) and reducing their associated toxicity in OSPW, however the mechanism by which the biodegradation of NAs occurs are poorly understood. Ozonation is superior over biodegradation in decreasing higher molecular weight alkyl branched NAs (preferentially, n ≥ 22, -6 ≥ z ≥ -12) as well as enabling accelerated biodegradation and reducing toxicity. Photolysis (UV at 254 nm) is effective in cleaving higher molecular weight NAs into smaller fragments that will be easier for microorganisms to degrade, whereas photocatalysis can metabolize selective NAs (0 ≥ z ≥ -6) efficiently and minimize their associated toxicity. Phytoremediation is applicable for metabolizing specific NAs (O(2), O(3), O(4), and O(5) species) and minimizing their associated toxicities. Petroleum coke (PC) adsorption is effective in reducing the more structurally complex NAs (preferentially 12 ≥ n ≥ 18 and z = -10, -12) and their toxicity in OSPWs, depending upon the PC content, pH and temperature. Several factors have influence on the degradation of NAs in OSPWs and aquatic environments, which include molecular mass and chemical structure of NAs, sediment structure, temperature, pH, dissolved oxygen, nutrients, and bacteria types. PMID:22217078

  14. Gastric microbiota and predicted gene functions are altered after subtotal gastrectomy in patients with gastric cancer.

    PubMed

    Tseng, Ching-Hung; Lin, Jaw-Town; Ho, Hsiu J; Lai, Zi-Lun; Wang, Chang-Bi; Tang, Sen-Lin; Wu, Chun-Ying

    2016-01-01

    Subtotal gastrectomy (i.e., partial removal of the stomach), a surgical treatment for early-stage distal gastric cancer, is usually accompanied by highly selective vagotomy and Billroth II reconstruction, leading to dramatic changes in the gastric environment. Based on accumulating evidence of a strong link between human gut microbiota and host health, a 2-year follow-up study was conducted to characterize the effects of subtotal gastrectomy. Gastric microbiota and predicted gene functions inferred from 16S rRNA gene sequencing were analyzed before and after surgery. The results demonstrated that gastric microbiota is significantly more diverse after surgery. Ralstonia and Helicobacter were the top two genera of discriminant abundance in the cancerous stomach before surgery, while Streptococcus and Prevotella were the two most abundant genera after tumor excision. Furthermore, N-nitrosation genes were prevalent before surgery, whereas bile salt hydrolase, NO and N2O reductase were prevalent afterward. To our knowledge, this is the first report to document changes in gastric microbiota before and after surgical treatment of stomach cancer. PMID:26860194

  15. Gastric microbiota and predicted gene functions are altered after subtotal gastrectomy in patients with gastric cancer

    PubMed Central

    Tseng, Ching-Hung; Lin, Jaw-Town; Ho, Hsiu J.; Lai, Zi-Lun; Wang, Chang-Bi; Tang, Sen-Lin; Wu, Chun-Ying

    2016-01-01

    Subtotal gastrectomy (i.e., partial removal of the stomach), a surgical treatment for early-stage distal gastric cancer, is usually accompanied by highly selective vagotomy and Billroth II reconstruction, leading to dramatic changes in the gastric environment. Based on accumulating evidence of a strong link between human gut microbiota and host health, a 2-year follow-up study was conducted to characterize the effects of subtotal gastrectomy. Gastric microbiota and predicted gene functions inferred from 16S rRNA gene sequencing were analyzed before and after surgery. The results demonstrated that gastric microbiota is significantly more diverse after surgery. Ralstonia and Helicobacter were the top two genera of discriminant abundance in the cancerous stomach before surgery, while Streptococcus and Prevotella were the two most abundant genera after tumor excision. Furthermore, N-nitrosation genes were prevalent before surgery, whereas bile salt hydrolase, NO and N2O reductase were prevalent afterward. To our knowledge, this is the first report to document changes in gastric microbiota before and after surgical treatment of stomach cancer. PMID:26860194

  16. Osteopetrorickets due to Snx10 Deficiency in Mice Results from Both Failed Osteoclast Activity and Loss of Gastric Acid-Dependent Calcium Absorption

    PubMed Central

    Ye, Liang; Morse, Leslie R.; Zhang, Li; Sasaki, Hajime; Mills, Jason C.; Odgren, Paul R.; Sibbel, Greg; Stanley, James R. L.; Wong, Gee; Zamarioli, Ariane; Battaglino, Ricardo A.

    2015-01-01

    Mutations in sorting nexin 10 (Snx10) have recently been found to account for roughly 4% of all human malignant osteopetrosis, some of them fatal. To study the disease pathogenesis, we investigated the expression of Snx10 and created mouse models in which Snx10 was knocked down globally or knocked out in osteoclasts. Endocytosis is severely defective in Snx10-deficent osteoclasts, as is extracellular acidification, ruffled border formation, and bone resorption. We also discovered that Snx10 is highly expressed in stomach epithelium, with mutations leading to high stomach pH and low calcium solubilization. Global Snx10-deficiency in mice results in a combined phenotype: osteopetrosis (due to osteoclast defect) and rickets (due to high stomach pH and low calcium availability, resulting in impaired bone mineralization). Osteopetrorickets, the paradoxical association of insufficient mineralization in the context of a positive total body calcium balance, is thought to occur due to the inability of the osteoclasts to maintain normal calcium–phosphorus homeostasis. However, osteoclast-specific Snx10 knockout had no effect on calcium balance, and therefore led to severe osteopetrosis without rickets. Moreover, supplementation with calcium gluconate rescued mice from the rachitic phenotype and dramatically extended life span in global Snx10-deficient mice, suggesting that this may be a life-saving component of the clinical approach to Snx10-dependent human osteopetrosis that has previously gone unrecognized. We conclude that tissue-specific effects of Snx10 mutation need to be considered in clinical approaches to this disease entity. Reliance solely on hematopoietic stem cell transplantation can leave hypocalcemia uncorrected with sometimes fatal consequences. These studies established an essential role for Snx10 in bone homeostasis and underscore the importance of gastric acidification in calcium uptake. PMID:25811986

  17. Models of Metabolic Community Structure in Martian Habitable Environments: Constraints from a Terrestrial Analog Acid-Sulfate Fumarole Environment, Cerro Negro Volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Rogers, K. L.; McCollom, T. M.; Hynek, B. M.

    2014-12-01

    Microbial habitability in extreme environments on Earth is described by microscale geochemical conditions that constrain metabolic niches in concert with long-term habitat stability that is governed by dynamic geologic processes. Using terrestrial analogs to identify habitable martian environments requires correlating microscale geochemical constraints with reconstructions of past martian environments that are based on global-scale observations. While past martian environments can be characterized by primary parameters (e.g. pH, redox, mineralogy, thermal history), microbial habitability on Earth is a complex function of both primary and derived parameters (e.g. metabolic reaction energetics, chemical & thermal gradients, flow dynamics). In recent years we have been investigating acid-sulfate fumaroles at the Mars analog site, Cerro Negro Volcano, Nicaragua, where habitability is constrained by steep thermal gradients, spatially- and temporally-variable vent dynamics, and limited water and nutrient availability. The most common niche identified thus far is found in fumaroles that host mixed photosynthetic and chemosynthetic endolithic microbial communities. One such endolith is dominated by acidic red algae (Cyanidiales), aerobic bacterial heterotrophs (Ktedonobacteria), and archaeal thermoacidophiles (Hyperthermus, Caldisphaera, and Thermofilum). An analysis of the metabolic structure suggests that primary production by the red algae supports the growth of heterotrophic thermoacidophiles. Diversification among the chemoheterotrophs with respect to temperature and oxygen tolerance suggests community adaptation to environmental gradients or variable venting dynamics. Furthermore, individual cells within the endolith are silica-encrusted, providing the possibility for biosignature formation and preservation. Putative hydrothermal environments on early Mars with similar conditions could have supported endolithic communities with comparable metabolic strategies. Even

  18. Effect of free dietary glutamate on gastric secretion in dogs.

    PubMed

    Zolotarev, Vasiliy; Khropycheva, Raisa; Uneyama, Hisayuki; Torii, Kunio

    2009-07-01

    The amino acid, L-glutamate, which is abundant in many foodstuffs, is a potent stimulator of gastric vagal afferents. The aim of the study was to evaluate a role of dietary glutamate in neuroendocrine control of gastric secretion of acid, pepsinogen, and fluid. In mongrel dogs with small gastric pouches surgically prepared according to Pavlov (vagally innervated) or Heidenhain (vagally decentralized), secretion in a pouch was induced by infusion into the main stomach of an amino acid-rich diet lacking glutamate (Elental) or the same diet supplemented with monosodium glutamate (MSG). Having no effect alone, MSG (100 mM) potentiated secretion induced by Elental both in Pavlov and Heidenhain models. In the Pavlov pouch, the effect of MSG was markedly reduced after i.v. injection of granisetron, an antagonist of 5-HT(3) receptors. In the Heidenhain model, MSG enhanced the stimulatory effect of pentagastrin (1 microg/kg, s.c.). In conclusion, dietary glutamate at doses not exceeding its common concentrations in foods substantially potentiates gastric phase secretion induced by stimulation of gastric mucosa with an amino acid-rich diet or by administration of pentagastrin. The effect of glutamate is partially mediated via serotonin secretion and stimulation of 5-HT(3) receptors. PMID:19686114

  19. Decreased gastric secretory functions in diabetic patients with autonomic neuropathy.

    PubMed

    Nakamura, T; Takebe, K; Imamura, K; Miyazawa, T; Ishii, M; Kudoh, K; Terada, A; Machida, K; Kikuchi, H; Kasai, F

    1994-06-01

    A total of 37 subjects consisted of 10 healthy subjects (Group III), 15 diabetic patients without autonomic neuropathy (Group II), and 12 diabetic patients with autonomic neuropathy including gastroparesis in 6 cases (Group I). All three groups were comparable in age. In order to clarify the gastric function in diabetic patients with autonomic neuropathy, secretion of serum gastrin, gastric secretory function, endoscopic Congo red test of fundic glands, and coefficiency of variance of electrocardiographic beat-to-beat intervals (C.V. R-R) were examined. In Group I, 5 patients had hypergastrinemia, but its elevation was inhibited when an acid solution was injected into the stomach. Gastric secretion and C.V. R-R were markedly lower in Group I, compared with Groups II and III. In Group I, the area of fundic glands (parietal cells) was reduced considerably. The C.V. R-R was significantly correlated with fasting serum gastrin concentration and with maximal acid output. From these results, in diabetic patients with autonomic neuropathy (vagal neuropathy), gastric acid secretion in response to tetragastrin stimulation was lowered with a reduction in area of fundic gland distribution. Hypergastrinemia may reflect a negative feedback mechanism responding to decreased acidity of gastric content in the antrum. PMID:7817384

  20. Pristine environments harbor a new group of oligotrophic 2,4-dichlorophenoxyacetic acid-degrading bacteria.

    PubMed Central

    Kamagata, Y; Fulthorpe, R R; Tamura, K; Takami, H; Forney, L J; Tiedje, J M

    1997-01-01

    2,4-Dichlorophenoxyacetic acid (2,4-D)-degrading bacteria were isolated from pristine environments which had no history of 2,4-D exposure. By using 2,4-D dye indicator medium or 14C-labeled 2,4-D medium, six strains were isolated from eight enrichment cultures capable of degrading 2,4-D. Phylogenetic analyses based on 16S ribosomal DNA (rDNA) sequencing and physiological properties revealed that one isolate from Hawaiian volcanic soil could be classified in the genus Variovorax (a member of the beta subdivision of the class Proteobacteria) and that the other five isolates from Hawaiian volcanic soils, Saskatchewan forest soil, and Chilean forest soil have 16S rDNAs with high degrees of similarity to those of the Bradyrhizobium group (a member of the alpha subdivision of the class Proteobacteria). All the isolates grow slowly on either nutrient media (0.1 x Bacto Peptone-tryptone-yeast extract-glucose [PTYG] or 0.1 x Luria broth [LB] medium) or 2,4-D medium, with mean generation times of 16 to 30 h, which are significantly slower than previously known 2,4-D degraders. Nutrient-rich media such as full-strength PTYG and LB medium did not allow their growth. PCR amplification using internal consensus sequences of tfdA (a gene encoding an enzyme for the first step of 2,4-D mineralization, found in pJP4 of Alcaligenes eutrophus JMP134 and some other 2,4-D-degrading bacteria) as primers and Southern hybridization with pJP4-tfdA as a probe revealed that the isolate belonging to the genus Variovorax carried the tfdA gene. This gene was transmissible to A. eutrophus JMP228 carrying a plasmid with a mutant tfdA gene. The other five isolates did not appear to carry tfdA, and 2,4-D-specific alpha-ketoglutarate-dependent dioxygenase activity could not be detected in cell lysates. These results indicate that 2,4-D-degrading bacteria in pristine environments are slow-growing bacteria and that most of their phylogenies and catabolic genes differ from those of 2,4-D degraders

  1. Organic amendments increase soil solution phosphate concentrations in an acid soil: A controlled environment study

    SciTech Connect

    Schefe, C.R.; Patti, A.F.; Clune, T.S.; Jackson, R.

    2008-04-15

    Soil acidification affects at least 4 million hectares of agricultural land in Victoria, Australia. Low soil pH can inhibit plant growth through increased soluble aluminum (Al) concentrations and decreased available phosphorus (P). The addition of organic amendments may increase P availability through competition for P binding sites, solubilization of poorly soluble P pools, and increased solution pH. The effect of two organic amendments (lignite and compost) on P solubility in an acid soil was determined through controlled environment (incubation) studies. Three days after the addition of lignite and compost, both treatments increased orthophosphate and total P measured in soil solution, with the compost treatments having the greatest positive effect. Increased incubation time (26 days) increased soil solution P concentrations in both untreated and amended soils, with the greatest effect seen in total P concentrations. The measured differences in solution P concentrations between the lignite- and compost-amended treatments were likely caused by differences in solution chemistry, predominantly solution pH and cation dynamics. Soil amendment with lignite or compost also increased microbial activity in the incubation systems, as measured by carbon dioxide respiration. Based on the results presented, it is proposed that the measured increase in soil solution P with amendment addition was likely caused by both chemical and biological processes, including biotic and abiotic P solubilization reactions, and the formation of soluble organic-metal complexes.

  2. A pharmaceutical product as corrosion inhibitor for carbon steel in acidic environments.

    PubMed

    Samide, Adriana

    2013-01-01

    A pharmaceutical product, Trimethoprim (TMP), IUPAC name: 5-(3,4,5-trimethoxybenzyl)pyrimidine-2,4-diamine was investigated, as inhibitor to prevent carbon steel corrosion in acidic environments. The study was performed using weight loss and electrochemical measurements, in temperatures ranging between 25-55°C. The surface morphology before and after corrosion of carbon steel in 1.0 M HCl solution in the presence and absence of TMP was evaluated using scanning electron microscopy (SEM). The inhibition efficiency (IE) increased with the increasing of the inhibitor concentration, reaching a maximum value of 92% at 25°C and 0.9 mM TMP, and decreased with increasing temperature. The inhibition of carbon steel corrosion by TMP can be attributed to the adsorption ability of inhibitor molecules onto the reactive sites of the metal surface. The adsorption is spontaneous and it is best described by the Langmuir isotherm. The apparent activation energy (E(a)) for the corrosion process in the absence and presence of TMP was evaluated from Arrhenius equation, to elucidate its inhibitive properties. PMID:23043337

  3. Immunotherapy in gastric cancer

    PubMed Central

    Matsueda, Satoko; Graham, David Y

    2014-01-01

    Gastric cancer is the second most common of cancer-related deaths worldwide. In the majority of cases gastric cancer is advanced at diagnosis and although medical and surgical treatments have improved, survival rates remain poor. Cancer immunotherapy has emerged as a powerful and promising clinical approach for treatment of cancer and has shown major success in breast cancer, prostate cancer and melanoma. Here, we provide an overview of concepts of modern cancer immunotherapy including the theory, current approaches, remaining hurdles to be overcome, and the future prospect of cancer immunotherapy in the treatment of gastric cancer. Adaptive cell therapies, cancer vaccines, gene therapies, monoclonal antibody therapies have all been used with some initial successes in gastric cancer. However, to date the results in gastric cancer have been disappointing as current approaches often do not stimulate immunity efficiently allowing tumors continue to grow despite the presence of a measurable immune response. Here, we discuss the identification of targets for immunotherapy and the role of biomarkers in prospectively identifying appropriate subjects or immunotherapy. We also discuss the molecular mechanisms by which tumor cells escape host immunosurveillance and produce an immunosuppressive tumor microenvironment. We show how advances have provided tools for overcoming the mechanisms of immunosuppression including the use of monoclonal antibodies to block negative regulators normally expressed on the surface of T cells which limit activation and proliferation of cytotoxic T cells. Immunotherapy has greatly improved and is becoming an important factor in such fields as medical care and welfare for human being. Progress has been rapid ensuring that the future of immunotherapy for gastric cancer is bright. PMID:24587645

  4. Gastric Mucormycosis with Hemolytic Uremic Syndrome.

    PubMed

    Raviraj, K Sunil; Miglani, P; Garg, A; Agarwal, P K

    2015-10-01

    Mucormycosis, is an emerging fungal infection in immunocompromised and diabetic individuals, usually affects rhino-orbito-cerebral, cutaneous and pulmonary regions. But mucormycosis in immunocompetent environment is rare and occurrence of gastric mucormycosis is unusual. We report a case of 19 year old female, with no pre-existing co-morbidities, presented with fever, dysentery, vomiting, and melena for 4 days. On evaluation she was found to have pancytopenia, acute kidney injury, hemolytic anemia, coagulopathy and hepatic derangement and treated with hemodialysis, plasmapheresis along with antibiotics and packed cell RBC transfusion. Upper gastrointestinal endoscopy revealed presence of extensive esophageal and gastric ulcer. In view of persistent bleeding despite endoscopic sclerotherapy, repetition of upper gastrointestinal endoscopy and CT abdomen with oral contrast was done, which revealed perforated gastric ulcer. Exploratory laparotomy and excision of ulcer was done. The biopsy of gastric ulcer had shown the presence of granulomatous necrotic areas positive for mucormycosis. Then she was managed with amphotericin-B, posoconazole with which she improved. PMID:27608699

  5. Prebiotic oligomerization of amino acids inside lipid vesicles of unsaturated and saturated fatty acids in hydrothermal environments

    NASA Astrophysics Data System (ADS)

    Imai, E.; Furuuchi, R.; Nemoto, A.; Hatori, K.; Honda, H.; Matsuno, K.

    We have already attempted an experimental model simulating seawater circulation in the vicinity of hydrothermal vents in the primitive ocean. We used a flow reactor that was constructed for simulating the pressure and temperature conditions of the hydrothermal vents. In the flow reactor, a high-temperature high-pressure fluid at 125˜ 250°C and at 20MPa was injected into a low temperature (0˜ 40°C ) chamber that was maintained at about the same high pressure as the fluid. We then experimentally examined a possibility of oligomerizing amino acids on or inside lipid vesicles. We compared three different kinds of lipid vesicles made of unsaturated fatty acids (oleic acid), saturated fatty acids (decanoic acid) and phospholipids (DPPC). Identification of the oligomeric products was made with the aid of an HPLC analysis. The oligomeric yields from glycine increased significantly in the presence of lipid vesicles compared to the case of their absence. On the other hand, there was found no significant difference in the yields of oligomers between in the presence of lipid vesicles dissolved by surfactant and in their absence. The possibility of lipid molecules serving as catalysts for oligomerization may be dismissed. The diameters of those lipid vesicles observed under a phase contrast microscope were about 10 micrometer or less. The total volume shared by oleic acid vesicles was about 5 % of the total volume of the suspension. Oligomerization of glycine inside oleic acid vesicles was enhanced more than 15 times compared to that proceeding in their outside. Enhancement of oligomerization of glycine in the presence of lipid vesicles was repeated as the reactants revisited the interface zone between the hot and cold regions. Even those lipid vesicles made of saturated fatty acid such as decanoic acid could have been functional in enhancing the oligomerization of monomers in their inside in the primitive ocean. References E. Imai, et al. (1999) Science 283, 831-833. H

  6. Evolution of a Genome-Encoded Bias in Amino Acid Biosynthetic Pathways Is a Potential Indicator of Amino Acid Dynamics in the Environment

    PubMed Central

    Fasani, Rick A.; Savageau, Michael A.

    2014-01-01

    Overcoming the stress of starvation is one of an organism’s most challenging phenotypic responses. Those organisms that frequently survive the challenge, by virtue of their fitness, will have evolved genomes that are shaped by their specific environments. Understanding this genotype–environment–phenotype relationship at a deep level will require quantitative predictive models of the complex molecular systems that link these aspects of an organism’s existence. Here, we treat one of the most fundamental molecular systems, protein synthesis, and the amino acid biosynthetic pathways involved in the stringent response to starvation. These systems face an inherent logical dilemma: Building an amino acid biosynthetic pathway to synthesize its product—the cognate amino acid of the pathway—may require that very amino acid when it is no longer available. To study this potential “catch-22,” we have created a generic model of amino acid biosynthesis in response to sudden starvation. Our mathematical analysis and computational results indicate that there are two distinctly different outcomes: Partial recovery to a new steady state, or full system failure. Moreover, the cell’s fate is dictated by the cognate bias, the number of cognate amino acids in the corresponding biosynthetic pathway relative to the average number of that amino acid in the proteome. We test these implications by analyzing the proteomes of over 1,800 sequenced microbes, which reveals statistically significant evidence of low cognate bias, a genetic trait that would avoid the biosynthetic quandary. Furthermore, these results suggest that the pattern of cognate bias, which is readily derived by genome sequencing, may provide evolutionary clues to an organism’s natural environment. PMID:25118252

  7. Androgen biosynthesis in the stomach: expression of cytochrome P450 17 alpha-hydroxylase/17,20-lyase messenger ribonucleic acid and protein, and metabolism of pregnenolone and progesterone by parietal cells of the rat gastric mucosa.

    PubMed

    Le Goascogne, C; Sananès, N; Eychenne, B; Gouézou, M; Baulieu, E E; Robel, P

    1995-04-01

    Dehydroepiandrosterone (DHEA) and its conjugates persist in the rat brain, for up to 1 month after ablation of both adrenals and gonads. Since DHEA synthesis in brain from pregnenolone (PREG) was excluded, we have considered other tissular sources including the digestive tract. In situ hybridization with specific oligonucleotide probes showed that the parietal cells of the gastric mucosa, contrary to other cell types, strongly expressed P450(17) alpha messenger RNA. Expression of the enzyme in the parietal cells was confirmed by immunocytochemistry with specific antibodies. An intense reaction was observed in the stomach of adult males and of cyclic or pregnant females. Access to food did not influence the intensity of immunostaining. It appeared at postnatal days 16-21, then the number of positive cells increased rapidly and leveled off at adult age. Parietal cells were released by pronase digestion of everted stomachs from adult male and female rats and were purified by density gradient centrifugation on Nycodenz. 5 x 10(4) to 1.6 x 10(6) cells were incubated with either 1 microM 14C-PREG or 14C-progesterone (14C-PROG) at 37 C under 95% O2-5% CO2, for 10-180 min. PREG was converted to 17-OH PREG and to androstenediol, whereas PROG was converted to 17-OH PROG and to testosterone. Only minute amounts of either DHEA or androstenedione, respectively, were detected at any incubation time, indicating their fast conversion to the corresponding 17 beta-hydroxysteroids. 3H-25-OH cholesterol was not metabolized to 3H-PREG, and 14C-PREG was not converted to 14C-PROG, in accordance with negative immunocytochemical results with antibodies to cytochrome P450scc and 3 beta-hydroxysteroid dehydrogenase delta 5-->4-isomerase (3 beta-HSD). In conclusion, the parietal cells, which are known as the source of gastric acid secretion, can synthesize testosterone from PROG and androstenediol from PREG. The physiological relevance of such conversions remains to be established. PMID

  8. Tyramine biosynthesis is transcriptionally induced at low pH and improves the fitness of Enterococcus faecalis in acidic environments.

    PubMed

    Perez, Marta; Calles-Enríquez, Marina; Nes, Ingolf; Martin, Maria Cruz; Fernandez, Maria; Ladero, Victor; Alvarez, Miguel A

    2015-04-01

    Enterococcus faecalis is a commensal bacterium of the human gut that requires the ability to pass through the stomach and therefore cope with low pH. E. faecalis has also been identified as one of the major tyramine producers in fermented food products, where they also encounter acidic environments. In the present work, we have constructed a non-tyramine-producing mutant to study the role of the tyramine biosynthetic pathway, which converts tyrosine to tyramine via amino acid decarboxylation. Wild-type strain showed higher survival in a system that mimics gastrointestinal stress, indicating that the tyramine biosynthetic pathway has a role in acid resistance. Transcriptional analyses of the E. faecalis V583 tyrosine decarboxylase cluster showed that an acidic pH, together with substrate availability, induces its expression and therefore the production of tyramine. The protective role of the tyramine pathway under acidic conditions appears to be exerted through the maintenance of the cytosolic pH. Tyramine production should be considered important in the adaptability of E. faecalis to acidic environments, such as fermented dairy foods, and to survive passage through the human gastrointestinal tract. PMID:25529314

  9. Helicobacter pylori eradication as a preventive tool against gastric cancer.

    PubMed

    Hamajima, Nobuyuki; Goto, Yasuyuki; Nishio, Kazuko; Tanaka, Daisuke; Kawai, Sayo; Sakakibara, Hisataka; Kondo, Takaaki

    2004-01-01

    Helicobacter pylori (H. pylori), which increases the risk of gastric diseases, including digestive ulcers and gastric cancer, is highly prevalent in Asian countries. There is no doubt that eradication of the bacterium is effective as a treatment of digestive ulcer, but eradication aiming to reduce the gastric cancer risk is still controversial. Observational studies in Japan demonstrated that the eradication decreased the gastric cancer risk among 132 stomach cancer patients undergoing endoscopical resection (65 treated with omeprazol and antibiotics and 67 untreated). In Columbia, 976 participants were randomized into eight groups in a three-treatment factorial design including H. pylori eradication, resulting in significant regression in the H. pylori eradication group. A recent randomized study in China also showed a significant reduction of gastric cancer risk among those without any gastric atrophy, intestinal metaplasia, and dysplasia. Efficacy of eradication may vary in extent among countries with different incidence rates of gastric cancer. Since the lifetime cumulative risk (0 to 84 years old) of gastric cancer in Japan is reported to be 12.7% for males and 4.8% for females (Inoue and Tominaga, 2003), the corresponding values for H. pylori infected Japanese can be estimated at 21.2% in males and 8.0% in females under the assumptions that the relative risk for infected relative to uninfected is 5 and the proportion of those infected is 0.5. Both the fact that not all individuals are infected among those exposed and the knowledge that only a small percentage of individuals infected with the bacterium develop gastric cancer, indicate the importance of gene-environment interactions. Studies on such interactions should provide useful information for anti-H. pylori preventive strategies. PMID:15373702

  10. Environment.

    ERIC Educational Resources Information Center

    White, Gilbert F.

    1980-01-01

    Presented are perspectives on the emergence of environmental problems. Six major trends in scientific thinking are identified including: holistic approaches to examining environments, life support systems, resource management, risk assessment, streamlined methods for monitoring environmental change, and emphasis on the global framework. (Author/SA)

  11. Involvement of the G-protein-coupled receptor 4 in RANKL expression by osteoblasts in an acidic environment

    SciTech Connect

    Okito, Asuka; Nakahama, Ken-ichi; Akiyama, Masako; Ono, Takashi; Morita, Ikuo

    2015-03-06

    Osteoclast activity is enhanced in acidic environments following systemic or local inflammation. However, the regulatory mechanism of receptor activator of NF-κB ligand (RANKL) expression in osteoblasts under acidic conditions is not fully understood. In the present paper, we detected the mRNA expression of the G-protein-coupled receptor (GPR) proton sensors GPR4 and GPR65 (T-cell death-associated gene 8, TDAG8), in osteoblasts. RANKL expression and the cyclic AMP (cAMP) level in osteoblasts were up-regulated under acidic culture conditions. Acidosis-induced up-regulation of RANKL was abolished by the protein kinase A inhibitor H89. To clarify the role of GPR4 in RANKL expression, GPR4 gain and loss of function experiments were performed. Gene knockdown and forced expression of GPR4 caused reduction and induction of RANKL expression, respectively. These results suggested that, at least in part, RANKL expression by osteoblasts in an acidic environment was mediated by cAMP/PKA signaling resulting from GPR4 activation. A comprehensive microarray analysis of gene expression of osteoblasts revealed that, under acidic conditions, the phenotype of osteoblasts was that of an osteoclast supporting cell rather than that of a mineralizing cell. These findings will contribute to a molecular understanding of bone disruption in an acidic environment. - Highlights: • RANKL expression was increased in osteoblasts under acidosis via cAMP/PKA pathway. • GRP4 knockdown resulted in decrease of RANKL expression. • GRP4 overexpression resulted in increase of RANKL expression. • Osteoblast mineralization was reduced under acidic condition.

  12. Efficacy and safety of herbal medicines in treating gastric ulcer: A review

    PubMed Central

    Bi, Wei-Ping; Man, Hui-Bin; Man, Mao-Qiang

    2014-01-01

    Gastric ulcer is a common disorder of the digestive system. Current therapeutic regimens largely rely on Western medicine. However, numerous studies have demonstrated that herbal medicines can effectively treat gastric ulcer in humans and various animal models via divergent mechanisms. This review updates the efficacy and safety of herbal medicines in treating gastric ulcer, and the mechanisms of their action in humans and animal models. Studies have demonstrated that the efficacy of herbal medicines is comparable or superior to that of drugs such as omeprazole or cimetidine in humans and animal models, and herbal medicines display fewer adverse effects. The mechanisms by which herbal medicines benefit gastric ulcer include stimulation of mucous cell proliferation, anti-oxidation, and inhibition of gastric acid secretion and H(+)/K(+)-ATPase activity. Some herbal medicines also exhibit antimicrobial properties. Utilization of herbal medicines could be a valuable alternative to treat gastric ulcer in humans effectively, with few adverse effects. PMID:25493014

  13. Effects of proton pump inhibitors on gastric emptying: a systematic review.

    PubMed

    Sanaka, Masaki; Yamamoto, Takatsugu; Kuyama, Yasushi

    2010-09-01

    The proton pump inhibitor (PPI) is widely used for the treatment of gastroesophageal reflux disease, peptic ulcer diseases, and functional dyspepsia. The pathogenesis of these acid-related and/or functional upper gastrointestinal disorders is potentially associated with abnormal gastric emptying. To date, variable effects of PPIs on gastric emptying have been reported. Therefore, it is relevant to gather and analyze published information on this topic. A systematic literature search has been performed, showing that the delaying effect of PPIs on gastric emptying of solid meals is consistent, whereas the effect of PPIs on the emptying of liquids is inconsistent. The underlying mechanisms whereby PPIs may affect gastric emptying have been discussed, most of which still remain hypothetic. Gastric emptying of solids involves a process of peptic hydrolysis. PPIs impair the hydrolytic digestion by inhibiting acid-dependent peptic activity, thereby delaying the solid emptying. Gastric emptying of liquids largely depends on volume and energy density of intragastric contents. PPIs variably modify the volume and the energy density by reducing gastric fluid secretion, thereby modifying the liquid emptying in an unpredictable manner. Hypergastrinemia has been considered to delay gastric emptying, but it seems of minor importance in the regulation of gastric emptying during PPI use. The delayed emptying of solids due to PPI therapy may have clinical implications in the management of gastroesophageal reflux disease, functional dyspepsia, as well as diabetes. PMID:20012198

  14. Aqueous suspension of anise “Pimpinella anisum” protects rats against chemically induced gastric ulcers

    PubMed Central

    Al Mofleh, Ibrahim A; Alhaider, Abdulqader A; Mossa, Jaber S; Al-Soohaibani, Mohammed O; Rafatullah, Syed

    2007-01-01

    AIM: To substantiate the claims of Unani and Arabian traditional medicine practitioners on the gastroprotective potential effect of a popular spice anise, “Pimpinella anisum L.” on experimentally-induced gastric ulceration and secretion in rats. METHODS: Acute gastric ulceration in rats was produced by various noxious chemicals including 80% ethanol, 0.2 mol/L NaOH, 25% NaCl and indomethacin. Anti-secretory studies were undertaken using pylorus-ligated Shay rat technique. Levels of gastric non-protein sulfhydryls (NP-SH) and wall mucus were estimated and gastric tissue was also examined histologically. Anise aqueous suspension was used in two doses (250 and 500 mg/kg body weight) in all experiments. RESULTS: Anise significantly inhibited gastric mu-cosal damage induced by necrotizing agents and indomethacin. The anti-ulcer effect was further confirmed histologically. In pylorus-ligated Shay rats, anise suspension significantly reduced the basal gastric acid secretion, acidity and completely inhibited the rumenal ulceration. On the other hand, the suspension significantly replenished ethanol-induced depleted levels of gastric mucosal NP-SH and gastric wall mucus concentration. CONCLUSION: Anise aqueous suspension possesses significant cytoprotective and anti-ulcer activities against experimentally-induced gastric lesions. The anti-ulcer effect of anise is possibly prostaglandin-mediated and/or through its anti-secretory and antioxidative properties. PMID:17373749

  15. Hydrogen Peroxide Cycling in Acidic Geothermal Environments and Potential Implications for Oxidative Stress

    NASA Astrophysics Data System (ADS)

    Mesle, M.; Beam, J.; Jay, Z.; Bodle, B.; Bogenschutz, E.; Inskeep, W.

    2014-12-01

    Hydrogen peroxide (H2O2) may be produced in natural waters via photochemical reactions between dissolved oxygen, organic carbon and light. Other reactive oxygen species (ROS) such as superoxide and hydroxyl radicals are potentially formed in environments with high concentrations of ferrous iron (Fe(II), ~10-100 μM) by reaction between H2O2 and Fe(II) (i.e., Fenton chemistry). Thermophilic archaea and bacteria inhabiting acidic iron-oxide mats have defense mechanisms against both extracellular and intracellular peroxide, such as peroxiredoxins (which can degrade H2O2) and against other ROS, such as superoxide dismutases. Biological cycling of H2O2 is not well understood in geothermal ecosystems, and geochemical measurements combined with molecular investigations will contribute to our understanding of microbial response to oxidative stress. We measured H2O2 and other dissolved compounds (Fe(II), Fe(III), H2S, O2), as well as photon flux, pH and temperature, over time in surface geothermal waters of several acidic springs in Norris Geyser Basin, Yellowstone National Park, WY (Beowulf Spring and One Hundred Spring Plain). Iron-oxide mats were sampled in Beowulf Spring for on-going analysis of metatranscriptomes and RT-qPCR assays of specific stress-response gene transcription (e.g., superoxide dismutases, peroxiredoxins, thioredoxins, and peroxidases). In situ analyses show that H2O2 concentrations are lowest in the source waters of sulfidic systems (ca. 1 μM), and increase by two-fold in oxygenated waters corresponding to Fe(III)-oxide mat formation (ca. 2 - 3 μM). Channel transects confirm increases in H2O2 as a function of oxygenation (distance). The temporal dynamics of H2O2, O2, Fe(II), and H2S in Beowulf geothermal waters were also measured during a diel cycle, and increases in H2O2 were observed during peak photon flux. These results suggest that photochemical reactions may contribute to changes in H2O2. We hypothesize that increases in H2O2 and O2

  16. Mineral-microorganism interactions in Acid Mine Drainage environments: preliminary results

    NASA Astrophysics Data System (ADS)

    Carbone, Cristina; Zotti, Mirca; Pozzolini, Marina; Giovine, Marco; Di Piazza, Simone; Mariotti, Mauro; Lucchetti, Gabriella

    2014-05-01

    Minerals play a key role in controlling the mobility and distribution of metals and metalloids of environmental concern in supergenic environments. These are involved in a variety of processes, spanning the alteration of primary minerals to the formation of secondary authigenic phases and can represent a source or a trap for Potentially Ecotoxic Elements (PTEs). Soil, sediments, and waters heavily polluted with PTEs through AMD processes are a reservoir of a unusual bacteria and fungi well adapted to these toxic environments. Classical studies of biotic weathering have mainly focused on water-mineral interaction and on the ability of microorganism to influence the soil solution chemical composition. In this work, we analyzed two different representative ochreous and greenish-blue AMD colloidal precipitates in order to i) characterize the biota population present in these colloidal minerals and ii) verify the bioaccumulation of PTEs into the fungi and the potential impact of bacteria in the geochemistry of the system. The samples are composed by nanocrystalline goethite which contains high amounts of Fe, Cu, Zn, Pb, and Ni and woodwardite that is characterized by Cu, Zn, Ni, Y, and Ce. These precipitates were examined in order to evaluate the presence of fungal strains and to extract bacteria DNA. The preliminary results of fungi characterization show an interesting and selected mycobiota able to survive under unfavourable environmental conditions. A significant number of fungal strains was isolated in pure culture. Most of them belong to the genus Mucor and Penicillium. It is worth noting the presence of Trametes versicolor, a macrofungal lignicolous species already known for heavy metal biosorption capability from aqueous solution (Gülay et al 2003). The same colloidal precipitates have been processed to extract bacteria DNA, using a specific procedure developed for DNA extraction from sediments. The results gave a good yield of nucleic acids and the positive PCR

  17. Melanoma with gastric metastases.

    PubMed

    Wong, Katherine; Serafi, Sam W; Bhatia, Abhijit S; Ibarra, Irene; Allen, Elizabeth A

    2016-01-01

    An 81-year-old woman with a history of malignant melanoma who presented with dyspnea and fatigue was found to have metastases to the stomach detected on endoscopy. Primary cutaneous malignant melanoma with gastric metastases is a rare occurrence, and it is often not detected until autopsy because of its non-specific manifestations. PMID:27609722

  18. Models of gastric emptying.

    PubMed Central

    Stubbs, D F

    1977-01-01

    Some empirical and theoretical models of the emptying behaviour of the stomach are presented. The laws of Laplace, Hooke, and Poisseuille are used to derive a new model of gastric emptying. Published data on humans are used to test the model and evaluate empirical constants. It is shown that for meals with an initial volume of larger than or equal to 300 ml, the reciprocal of the cube root of the volume of meal remaining is proportional to the time the meal is in the stomach.For meals of initial volume of less than 300 ml the equation has to be corrected for the fact that the 'resting volume' of gastric contents is about 28 ml. The more exact formula is given in the text. As this model invokes no neural or hormonal factors, it is suggested that the gastric emptying response to the volume of a meal does not depend on these factors. The gastric emptying response to the composition of the meal does depend on such factors and a recent model of this process is used to evaluate an empirical constant. PMID:856678

  19. Photosynthesis and photo-stability of nucleic acids in prebiotic extraterrestrial environments.

    PubMed

    Sandford, Scott A; Bera, Partha P; Lee, Timothy J; Materese, Christopher K; Nuevo, Michel

    2015-01-01

    Laboratory experiments have shown that the UV photo-irradiation of low-temperature ices of astrophysical interest leads to the formation of organic molecules, including molecules important for biology such as amino acids, quinones, and amphiphiles. When pyrimidine is introduced into these ices, the products of irradiation include the nucleobases uracil, cytosine, and thymine, the informational sub-units of DNA and RNA, as well as some of their isomers. The formation of these compounds, which has been studied both experimentally and theoretically, requires a succession of additions of OH, NH₂, and CH₃groups to pyrimidine. Results show that H₂O ice plays key roles in the formation of the nucleobases, as an oxidant, as a matrix in which reactions can take place, and as a catalyst that assists proton abstraction from intermediate compounds. As H₂O is also the most abundant icy component in most cold astrophysical environments, it probably plays the same roles in space in the formation of biologically relevant compounds. Results also show that although the formation of uracil and cytosine from pyrimidine in ices is fairly straightforward, the formation of thymine is not. This is mostly due to the fact that methylation is a limiting step for its formation, particularly in H₂O-rich ices, where methylation must compete with oxidation. The relative inefficiency of the abiotic formation of thymine to that of uracil and cytosine, together with the fact that thymine has not been detected in meteorites, are not inconsistent with the RNA world hypothesis. Indeed, a lack of abiotically produced thymine delivered to the early Earth may have forced the choice for an RNA world, in which only uracil and cytosine are needed, but not thymine. PMID:24500331

  20. Potential role of stabilized Criegee radicals in sulfuric acid production in a high biogenic VOC environment.

    PubMed

    Kim, Saewung; Guenther, Alex; Lefer, Barry; Flynn, James; Griffin, Robert; Rutter, Andrew P; Gong, Longwen; Cevik, Basak Karakurt

    2015-03-17

    We present field observations made in June 2011 downwind of Dallas-Fort Worth, TX, and evaluate the role of stabilized Criegee radicals (sCIs) in gaseous sulfuric acid (H2SO4) production. Zero-dimensional model calculations show that sCI from biogenic volatile organic compounds composed the majority of the sCIs. The main uncertainty associated with an evaluation of H2SO4 production from the sCI reaction channel is the lack of experimentally determined reaction rates for sCIs formed from isoprene ozonolysis with SO2 along with systematic discrepancies in experimentally derived reaction rates between other sCIs and SO2 and water vapor. In general, the maximum of H2SO4 production from the sCI channel is found in the late afternoon as ozone increases toward the late afternoon. The sCI channel, however, contributes minor H2SO4 production compared with the conventional OH channel in the mid-day. Finally, the production and the loss rates of H2SO4 are compared. The application of the recommended mass accommodation coefficient causes significant overestimation of H2SO4 loss rates compared with H2SO4 production rates. However, the application of a lower experimental value for the mass accommodation coefficient provides good agreement between the loss and production rates of H2SO4. The results suggest that the recommended coefficient for the H2O surface may not be suitable for this relatively dry environment. PMID:25700170

  1. Microscale Biosensor for Measurement of Volatile Fatty Acids in Anoxic Environments

    PubMed Central

    Meyer, Rikke Louise; Larsen, Lars Hauer; Revsbech, Niels Peter

    2002-01-01

    A microscale biosensor for acetate, propionate, isobutyrate, and lactate is described. The sensor is based on the bacterial respiration of low-molecular-weight, negatively charged species with a concomitant reduction of NO3− to N2O. A culture of denitrifying bacteria deficient in N2O reductase was immobilized in front of the tip of an electrochemical N2O microsensor. The bacteria were separated from the outside environment by an ion-permeable membrane and supplied with nutrients (except for electron donors) from a medium reservoir behind the N2O sensor. The signal of the sensor, which corresponded to the rate of N2O production, was proportional to the supply of the electron donor to the bacterial mass. The selectivity for volatile fatty acids compared to other organic compounds was increased by selectively enhancing the transport of negatively charged compounds into the sensor by electrophoretic migration (electrophoretic sensitivity control). The sensor was susceptible to interference from O2, N2O, NO2−, H2S, and NO3−. Interference from NO3− was low and could be quantified and accounted for. The detection limit was equivalent to about 1 μM acetate, and the 90% response time was 30 to 90 s. The response of the sensor was not affected by changes in pH between 5.5 and 9 and was also unaffected by changes in salinity in the range of 2 to 32‰. The functioning of the sensor over a temperature span of 7 to 30°C was investigated. The concentration range for a linear response was increased five times by increasing the temperature from 7 to 19.5°C. The life span of the biosensor varied between 1 and 3 weeks after manufacturing. PMID:11872469

  2. Investigation of nitrous acid concentration in an indoor environment using an in-situ monitoring system

    NASA Astrophysics Data System (ADS)

    Park, Seung Shik; Hong, Jin H.; Lee, Jai H.; Kim, Young J.; Cho, Sung Y.; Kim, Seung J.

    An in-situ measurement system for the determination of nitrous acid (HONO) was developed and used at an indoor residential environment. The system uses a diffusion scrubber to sample gaseous HONO and the peroxynitrite-induced luminol chemiluminescent method to quantify the amount of HONO. In this system, the detection limit of HONO, estimated as three times the noise level of the scrubbing solution blank, was 120 pptv for a 2-min integrated sample. Indoor HONO and NO x concentrations were determined for 7 days in the living room of an apartment with a gas range for cooking in the kitchen. Close examination of the relationships among HONO, NO, and NO 2 concentrations during both the background and combustion periods confirm that the observed HONO was formed not only by direct emission from gas combustion, but also from heterogeneous reactions of NO 2 with H 2O on indoor surfaces. The average ratio of HONO to NO 2 over the study period was 0.12 ± 0.05. The HONO/NO 2 concentration ratio was 0.04-0.08 during the combustion period, whereas it was 0.10-0.25 after combustion had stopped. This suggests that HONO was generated through different production processes, both during combustion and after the completion of combustion. The controlled combustion experiments indicate that the burning rate is an important factor to determine the peak HONO concentration. In darkness, HONO had a nearly constant removal rate for all of the combustion experiments, whereas the removal rates of NO and NO 2 depended on the burning rates of the gas range. Combustion experiments conducted at the fixed burning rate setting show also that ventilation decreased HONO concentration. This indicates that the airflow rate of the range hood fan is an important factor to control the concentration of indoor air pollutants.

  3. Effect of centrophenoxine on water-immersion restraint stress- and chemically-induced gastric ulcers in rats.

    PubMed

    Al Moutaery, Ahmed R

    2003-01-01

    Recent studies clearly suggest a role of central nervous system in regulation of gastrointestinal function and defense against ulcerogens. In the present study, attempt was made to investigate the effect of centrophenoxine (CPH), a nootropic drug on gastric acid secretion and experimentally induced gastric ulcer in rats. Acid secretion studies were undertaken using pylorus-ligated rats pretreated with CPH (10-100 mg/kg, i.p.). The effect of orally administered CPH on water-immersion restraint (WIR) stress, indomethacin and ethanol-induced gastric ulcers was also examined. The level of myeloperoxidase (MPO), non-protein sulfhydryls (NP-SH) and gastric wall mucus was measured in the glandular stomach of rats following ethanol-induced gastric lesions. There was a dose-dependent inhibition of gastric acid secretion in the CPH treated rats. Pretreatment with CPH significantly protected gastric mucosa against ethanol and indomethacin induced gastric lesion. Only low dose of CPH (30 mg/kg) was found to be effective against stress ulcers. A significant attenuation of ethanol-induced increase in gastric MPO activity, depletion of NP-SH and reduction of gastric wall mucus was also observed in CPH treated rats. These findings clearly suggest the involvement of endogenous pro-inflammatory mediators and oxidative stress in mediating the gastroprotective effect of CPH. PMID:15686106

  4. Amino acids in haemolymph, single fibres and whole muscle from the claw of freshwater crayfish acclimated to different osmotic environments.

    PubMed

    Dooley, P C; Long, B M; West, J M

    2000-10-01

    The concentrations of free amino acids were measured in whole claw muscle, single fibres and haemolymph of Australian freshwater crayfish, Cherax destructor, during the intermoult stage. The average total pool of amino acids in short-sarcomere fibres (179 mmol kg(-1)) was 60% greater than in long-sarcomere fibres, due to higher concentrations of alanine, cysteine, glutamate, leucine and proline. The two fibre types exhibited differences in the banding pattern of the isoforms of troponin using gel electrophoresis. The average pool of amino acids in haemolymph was 2.7 mmol kg(-1). Cherax has symmetrical claws and the total pool of amino acids from whole muscles (approx. 79 mmol kg(-1)) was similar in left and right claw muscles. In animals acclimated to osmotic environments between 0 and 220 mOsm, the osmotic pressure of the haemolymph increased from 356 to 496 mOsm, but no systematic changes were observed in the amino acid profiles of muscles or haemolymph. The major findings were that (a) concentrations of amino acids differed between the two major fibre types in claw muscle and (b) amino acids in the muscle fibres did not play a major part in intracellular osmoregulation in Cherax, suggesting this species is an anisosmotic regulator. PMID:11064283

  5. Gastritis and Gastric Ulcers in Working Dogs

    PubMed Central

    Davis, Michael S.; Williamson, Katherine K.

    2016-01-01

    Gastritis and gastric ulcers are an important cause of morbidity and mortality in canine athletes. Although the majority of scientific work on this condition has been performed in ultraendurance racing sled dogs, this condition has been identified in other canine athletes, including sled dogs competing in shorter events and dogs performing off-leash explosive detection duties. The cause of the syndrome is unknown, but current hypotheses propose a link between exercise-induced hyperthermia and loss of gastric mucosal barrier function as an early event in the pathogenesis. Treatment is focused on prevention of clinical disease using acid secretion inhibitors, such as omeprazole, which has excellent efficacy in controlled clinical studies. PMID:27092307

  6. Fresh-cut Lettuce in Modified Atmosphere Packages Stored at Improper Temperatures Support Enterohemorrhagic E. coli Isolates to Survive Gastric Acid Challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incidences of food-borne outbreaks involving enterohemorrhagic Escherichia coli strains with mutations in a key regulatory gene, rpoS, have been reported. Incentives, if any, for losing this regulatory function are not clear since the RpoS regulator is required for the expression of several environ...

  7. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... The test is done after you have not eaten for a while so fluid is all that remains in ... injected into your body. This is done to test the ability of the cells in the stomach ...

  8. Influence of thyroid states on stress gastric ulcer formation

    SciTech Connect

    Hernandez, D.E.; Walker, C.H.; Mason, G.A.

    1988-01-01

    This study was designed to test the hypothesis that thyroid states may affect the acute development of gastric lesions induced by cold-resistant stress. Normal (euthyroid), hyperthyroid and hypothyroid rats were used. Gastric lesion incidence and severity was significantly increased in hypothyroid rats, whereas in contrast hyperthyroid rats developed significantly less gastric lesions. As anticipated, plasma levels of thyroxin (T/sub 4/) were significantly elevated in hyperthyroid rats, and undetectable in hypothyroid rats. Acute pretreatment with i.p. cimetidine, but not T/sub 4/ 1 h prior to stress completely prevented gastric lesions formation in hypothyroid rats. Finally, binding of /sup 3/H-dihydroalprenolol to ..beta..-adrenergic receptors on brain membranes prepared from frontal cortex was reduced by 20% in hypothyroid rats after 3 h of stress. These and other data contained herein suggest that thyroid hormones contribute to modulate the responsiveness of the gastric mucosa to stress. The increase rate of ulcerogenesis observed in hypothyroid rats appears to be mediated by gastric acid secretion. The central mechanism for this response may involve decreased brain nonadrenergic receptor function.

  9. Inhibition of gastric secretion in guinea pig by relatively low dose ionizing radiation

    SciTech Connect

    Batzri, S.; Catravas, G.

    1988-11-01

    We evaluated the effect of a single dose of ionizing radiation on gastric secretion in awake guinea pigs equipped with a permanent gastric cannula. Changes in gastric secretion were measured using a dye dilution technique. Infusion of histamine increased acid and fluid output and there was a positive correlation (r = 0.93) between the two. Total body irradiation with 400 cGy, like cimetidine, suppressed acid and fluid secretion under basal conditions and during histamine stimulation by 50-90%. Recovery from the radiation damage was only partial after one week. Irradiation inhibited the rise in gastric juice volume during histamine stimulation and also reduced the normal gain in body weight of the guinea pig. These results demonstrate that ionizing radiations have an immediate and long lasting effects on the gastric mucosal function of the guinea pig.

  10. Drugs Approved for Stomach (Gastric) Cancer

    MedlinePlus

    ... Professionals Questions to Ask about Your Treatment Research Drugs Approved for Stomach (Gastric) Cancer This page lists ... stomach (gastric) cancer that are not listed here. Drugs Approved for Stomach (Gastric) Cancer Cyramza (Ramucirumab) Docetaxel ...

  11. Gastric metastasis from salivary duct carcinoma mimicking primary gastric cancer

    PubMed Central

    Yamashita, Kanefumi; Takeno, Shinsuke; Nimura, Satoshi; Sugiyama, Yoshikazu; Sueta, Takayuki; Maki, Kenji; Kayashima, Yoshiyuki; Shiwaku, Hironari; Kato, Daisuke; Hashimoto, Tatsuya; Sasaki, Takamitsu; Yamashita, Yuichi

    2016-01-01

    Introduction We present a very rare case of gastric metastasis mimicking primary gastric cancer in a patient who had undergone surgery for salivary duct carcinoma. Presentation of case A 67-year-old man had been diagnosed as having right parotid cancer and had undergone a right parotidectomy and lymph node dissection. The histological diagnosis was salivary duct carcinoma. One year after the surgery, a positron emission tomography–computed tomography scan using fluorodeoxyglucose (FDG) revealed an abnormal uptake of FDG in the left cervical, mediastinal, paraaortic, and cardiac lymph nodes; stomach; and pancreas. On gastroduodenoscopy, there was a huge, easily bleeding ulcer mimicking primary gastric cancer at the upper body of the stomach. Biopsy revealed poorly differentiated adenocarcinoma. Therefore, we were unable to differentiate between the primary gastric cancer and the metastatic tumor using gastroduodenoscopy and biopsy. Because of the uncontrollable bleeding from the gastric cancer, we performed an emergency palliative total gastrectomy. On histological examination, the gastric lesion was found to be metastatic carcinoma originating from the salivary duct carcinoma. Discussion In the presented case, we could not diagnose the gastric metastasis originating from the salivary duct carcinoma even by endoscopic biopsy. This is because the histological appearance of salivary duct carcinoma is similar to that of high-grade adenocarcinoma, thus, resembling primary gastric cancer. Conclusion When we perform endoscopic examination of patients with malignant neoplasias, a possibility of metastatic gastric cancer should be taken into consideration. PMID:27085106

  12. Clinical epidemiology of gastric cancer

    PubMed Central

    Ang, Tiing Leong; Fock, Kwong Ming

    2014-01-01

    Gastric cancer is the second leading cause of cancer-related mortality and the fourth most common cancer globally. There are, however, distinct differences in incidence rates in different geographic regions. While the incidence rate of gastric cancer has been falling, that of gastric cardia cancers is reportedly on the rise in some regions. Helicobacter pylori (H. pylori) infection is a major risk factor of non-cardia gastric cancer, and data has emerged concerning the role of H. pylori eradication for primary prevention of gastric cancer. Dietary, lifestyle and metabolic factors have also been implicated. Although addressing these other factors may contribute to health, the actual impact in terms of cancer prevention is unclear. Once irreversible histological changes have occurred, endoscopic surveillance would be necessary. A molecular classification system offers hope for molecularly tailored, personalised therapies for gastric cancer, which may improve the prognosis for patients. PMID:25630323

  13. COMPARISON OF AEROSOL ACIDITY IN URBAN AND SEMI-RURAL ENVIRONMENTS

    EPA Science Inventory

    During the summer of 1990, acid aerosol, acid gas. and ammonia measurements were conducted simultaneously at three locations in central and western Pennsylvania where population levels were large (metropolitan Pittsburgh> and small (semi-rural communities of Uniontown and State C...

  14. NMDA Receptors of Gastric-Projecting Neurons in the Dorsal Motor Nucleus of the Vagus Mediate the Regulation of Gastric Emptying by EA at Weishu (BL21).

    PubMed

    Zhang, Xin; Cheng, Bin; Jing, Xianghong; Qiao, Yongfa; Gao, Xinyan; Yu, Huijuan; Zhu, Bing; Qiao, Haifa

    2012-01-01

    A large number of studies have been conducted to explore the efficacy of electroacupuncture (EA) for the treatment of gastrointestinal motility. While several lines of evidence addressed the basic mechanism of EA on gastrointestinal motility regarding effects of limb and abdomen points, the mechanism for effects of the back points on gastric motility still remains unclear. Here we report that the NMDA receptor (NMDAR) antagonist kynurenic acid inhibited the gastric emptying increase induced by high-intensity EA at BL21 and agonist NMDA enhanced the effect of the same treatment. EA at BL21 enhanced NMDAR, but not AMPA receptor (AMPAR) component of miniature excitatory postsynaptic current (mEPSC) in gastric-projecting neurons of the dorsal motor nucleus of the vagus (DMV). In sum, our data demonstrate an important role of NMDAR-mediated synaptic transmission of gastric-projecting DMV neurons in mediating EA at BL21-induced enhancement of gastric emptying. PMID:22654955

  15. Effects of MCI-727, a new antiulcer agent, on various gastric and duodenal lesions in experimental animals.

    PubMed

    Yamazaki, S; Kawamura, M; Kitsukawa, M; Ando, K; Nitta, I; Tobe, A; Okabe, S

    1991-04-01

    Effects of a new antiulcer drug, MCI-727, on gastric and duodenal lesions, gastric secretion and gastric motility were studied in comparison with cimetidine and teprenone. MCI-727 dose-dependently (3-100 mg/kg, p.o. or i.d.) inhibited the development of acute gastric or duodenal lesions such as pyrolus ligation-, water-immersion stress-, indomethacin-, HCl-, HCl-ethanol-induced gastric lesions and cysteamine-induced duodenal lesions in rats and histamine-induced duodenal lesions in guinea pigs. These antiulcer effects exceeded those of cimetidine or teprenone. Repeated administration of MCI-727 (0.3-3 mg/kg/day, p.o., for 10 days) significantly promoted the spontaneous healing of acetic acid-induced chronic gastric ulcers. Concerning gastric acid secretion, MCI-727 selectively inhibited tetragastrin-stimulated acid secretion without effecting basal acid secretion and acid secretion by other stimuli. Cimetidine and teprenone inhibited acid secretion in several cases. MCI-727 and teprenone had inhibitory effects on gastric motility, although cimetidine had no effect. These results suggest that MCI-727 has a wide spectrum of antiulcer activity, and its mode of antiulcer action is different from that of cimetidine or teprenone. PMID:1886287

  16. Methods of chemical analysis for selected species in marble and limestone surfaces exposed to the acidic outdoor environment

    SciTech Connect

    Jensen, K.J.; Williams, F.L.; Huff, E.A.; Youngdahl, C.A.

    1986-03-01

    There is concern for marble and limestone exposed to the acidic outdoor environment because they are widely used as the exterior structures of buildings and monuments and because the calcium carbonate stones are especially sensitive to acid. Field tests of these building materials under carefully monitored environmental conditions are being conducted to measure damage rates and ultimately to quantify the individual effects of the important damage mechanisms. The development of further quantitative understanding will provide an improved basis for control strategies. The demonstration, verification, and application of a technique to measure selected surface anionic and cationic species are important contributions to this study. These methods of stone surface chemical analysis, developed for and applied in the National Acid Precipitation Assessment Program (NAPAP), are appropriate to monitor selected species of program interest and are sufficient to determine surface sulfate and nitrate reaction products.

  17. Expression of the ompATb operon accelerates ammonia secretion and adaptation of Mycobacterium tuberculosis to acidic environments.

    PubMed

    Song, Houhui; Huff, Jason; Janik, Katharine; Walter, Kerstin; Keller, Christine; Ehlers, Stefan; Bossmann, Stefan H; Niederweis, Michael

    2011-05-01

    Homeostasis of intracellular pH is a trait critical for survival of Mycobacterium tuberculosis in macrophages. However, mechanisms by which M. tuberculosis adapts to acidic environments are poorly understood. In this study, we analysed the physiological functions of OmpATb, a surface-accessible protein of M. tuberculosis. OmpATb did not complement the permeability defects of a Mycobacterium smegmatis porin mutant to glucose, serine and glycerol, in contrast to the porin MspA. Uptake rates of these solutes were unchanged in an ompATb operon mutant of M. tuberculosis indicating that OmpATb is not a general porin. Chemical analysis of low-pH culture filtrates showed that the proteins encoded by the ompATb operon are involved in generating a rapid ammonia burst, which neutralized medium pH and preceded exponential growth of M. tuberculosis. Addition of ammonia accelerated growth of the ompATb operon mutant demonstrating that ammonia secretion is indeed a mechanism by which M. tuberculosis neutralizes acidic environments. Infection experiments revealed that the ompATb operon was not required for full virulence in mice suggesting that M. tuberculosis has multiple mechanisms of resisting phagosomal acidification. Taken together, these results show that the ompATb operon is necessary for rapid ammonia secretion and adaptation of M. tuberculosis to acidic environments in vitro but not in mice. PMID:21410778

  18. Carbonate-based Janus micromotors moving in ultra-light acidic environment generated by HeLa cells in situ

    PubMed Central

    Guix, Maria; Meyer, Anne K.; Koch, Britta; Schmidt, Oliver G.

    2016-01-01

    Novel approaches to develop naturally-induced drug delivery in tumor environments in a deterministic and controlled manner have become of growing interest in recent years. Different polymeric-based microstructures and other biocompatible substances have been studied taking advantage of lactic acidosis phenomena in tumor cells, which decrease the tumor extracellular pH down to 6.8. Micromotors have recently demonstrated a high performance in living systems, revealing autonomous movement in the acidic environment of the stomach or moving inside living cells by using acoustic waves, opening the doors for implementation of such smart microengines into living entities. The need to develop biocompatible motors which are driven by natural fuel sources inherently created in biological systems has thus become of crucial importance. As a proof of principle, we here demonstrate calcium carbonate Janus particles moving in extremely light acidic environments (pH 6.5), whose motion is induced in conditioned acidic medium generated by HeLa cells in situ. Our system not only obviates the need for an external fuel, but also presents a selective activation of the micromotors which promotes their motion and consequent dissolution in presence of a quickly propagating cell source (i.e. tumor cells), therefore inspiring new micromotor configurations for potential drug delivery systems. PMID:26905939

  19. Gastric cancer review

    PubMed Central

    Carcas, Lauren Peirce

    2014-01-01

    Gastric cancer is an aggressive disease that continues to have a daunting impact on global health. Despite an overall decline in incidence over the last several decades, gastric cancer remains the fourth most common type of cancer and is the second leading cause of cancer-related death worldwide. This review aims to discuss the global distribution of the disease and the trend of decreasing incidence of disease, delineate the different pathologic subtypes and their immunohistochemical (IHC) staining patterns and molecular signatures and mutations, explore the role of the pathogen H. pylori in tumorgenesis, discuss the increasing incidence of the disease in the young, western populations and define the role of biologic agents in the treatment of the disease. PMID:25589897

  20. Analytical electron microscopy of a crack tip extracted from a stressed Alloy 800 sample exposed to an acid sulfate environment.

    PubMed

    Persaud, S Y; Carcea, A G; Huang, J; Korinek, A; Botton, G A; Newman, R C

    2014-06-01

    Alloy 800 (Fe-21Cr-33Ni) has been found susceptible to cracking in acid sulfate environments, but the mechanism is not well understood. Alloy 800 C-ring samples were exposed to an acid sulfate environment at 315°C and cracks were found with depths in excess of 300μm after 60h. Preparation of a TEM sample containing crack tips is challenging, but the ability to perform high-resolution microscopy at the crack tip would lend insight to the mechanism of acid sulfate stress corrosion cracking (AcSCC). The lift-out technique combined with a focused ion beam sample preparation was used to extract a crack tip along the cross-section of an acid sulfate crack in an Alloy 800 C-ring. TEM elemental analysis was done using EDS and EELS which identified a duplex oxide within the crack; an inner oxide consisting of a thin 3-4nm Cr-rich oxide and an outer oxide enriched in Fe and Cr. Preliminary conclusions and hypotheses resulted with respect to the mechanism of AcSCC in Alloy 800. PMID:24792448

  1. Helicobacter pylori in gastric carcinogenesis.

    PubMed

    Ahn, Hyo Jun; Lee, Dong Soo

    2015-12-15

    Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori (H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to the occurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cagA and vacA are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis. PMID:26690981

  2. Helicobacter pylori in gastric carcinogenesis

    PubMed Central

    Ahn, Hyo Jun; Lee, Dong Soo

    2015-01-01

    Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori (H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to the occurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cagA and vacA are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis. PMID:26690981

  3. Investigation of the influence of gastric acid on the surface roughness of ceramic materials of metal-ceramic restorations. An in vitro study.

    PubMed

    Matsou, Eirini; Vouroutzis, Nikolaos; Kontonasaki, Eleana; Paraskevopoulos, Konstantinos M; Koidis, Petros

    2011-01-01

    The rehabilitation of eroded teeth in patients suffering from bulimia nervosa generally includes ceramics. This study compared the roughness of three ceramics before and after exposure to simulated vomit solution (SVS) with a pH of 3.8. Surface roughness parameters Ra, RMS, and AH were calculated using atomic force microscopy before and after exposure to SVS (novel peristaltic pump for 24 hours at 37°C) and were analyzed statistically. Apart from the initial high AH values of the glass-ceramic, none of the parameters evaluated were statistically significantly different after acid exposure. Under the limitations of this in vitro study, the investigated ceramics seem suitable for use in bulimia nervosa patients. PMID:21209998

  4. Adsorption behavior of antimony(III) oxyanions on magnetite surface in aqueous organic acid environment

    NASA Astrophysics Data System (ADS)

    Mittal, Vinit K.; Bera, Santanu; Narasimhan, S. V.; Velmurugan, S.

    2013-02-01

    Antimony(III) adsorption is observed on magnetite (Fe3O4) surface under acidic and reducing condition through surface hydroxyl (SOH) groups bonding on Fe3O4 surface. Desorption of adsorbed Sb(III) is observed from Fe3O4 surface along with iron release in organic acid at 85 °C after 5 h of experiment. Tartaric acid (TA) shows minimum Sb(III) adsorption on Fe3O4 among the organic acid studied. The reason is TA having two sets of adjacent functional groups viz. Odbnd Csbnd OH and Csbnd OH which are responsible for the formation of five-membered bidendate chelate with Sb(III). Other oxyanions, cations or complexing agents along with TA influences the Sb(III) adsorption on Fe3O4. The surface of magnetite is modified by the addition of fatty acids viz. Lauric acid, benzoic acid to bind the Ssbnd OH groups present on the surface. This results in delaying the process of adsorption without changing the quantity of saturation adsorption of Sb(III) on Fe3O4 surface.

  5. The role of the obestatin/GPR39 system in human gastric adenocarcinomas

    PubMed Central

    Alén, Begoña O.; Leal-López, Saúl; Alén, María Otero; Viaño, Patricia; García-Castro, Victoria; Mosteiro, Carlos S.; Beiras, Andrés; Casanueva, Felipe F.; Gallego, Rosalía; García-Caballero, Tomás; Camiña, Jesús P.; Pazos, Yolanda

    2016-01-01

    Obestatin, a 23-amino acid peptide encoded by the ghrelin gene, and the GPR39 receptor were reported to be involved in the control of mitogenesis of gastric cancer cell lines; however, the relationship between the obestatin/GPR39 system and gastric cancer progression remains unknown. In the present study, we determined the expression levels of the obestatin/GPR39 system in human gastric adenocarcinomas and explored their potential functional roles. Twenty-eight patients with gastric adenocarcinomas were retrospectively studied, and clinical data were obtained. The role of obestatin/GPR39 in gastric cancer progression was studied in vitro using the human gastric adenocarcinoma AGS cell line. Obestatin exogenous administration in these GPR39-bearing cells deregulated the expression of several hallmarks of the epithelial-mesenchymal transition (EMT) and angiogenesis. Moreover, obestatin signaling promoted phenotypic changes via GPR39, increasingly impacting on the cell morphology, proliferation, migration and invasion of these cells. In healthy human stomachs, obestatin expression was observed in the neuroendocrine cells and GPR39 expression was localized mainly in the chief cells of the oxyntic glands. In human gastric adenocarcinomas, no obestatin expression was found; however, an aberrant pattern of GPR39 expression was discovered, correlating to the dedifferentiation of the tumor. Altogether, our data strongly suggest the involvement of the obestatin/GPR39 system in the pathogenesis and/or clinical outcome of human gastric adenocarcinomas and highlight the potential usefulness of GPR39 as a prognostic marker in gastric cancer. PMID:26716511

  6. The human gastric microbiota: Is it time to rethink the pathogenesis of stomach diseases?

    PubMed Central

    Compare, Debora

    2015-01-01

    Introduction Although long thought to be a sterile organ, due to its acid production, the human stomach holds a core microbiome. Aim To provide an update of findings related to gastric microbiota and its link with gastric diseases. Methods We conducted a systematic review of the literature. Results The development of culture-independent methods facilitated the identification of many bacteria. Five major phyla have been detected in the stomach: Firmicutes, Bacteroidites, Actinobacteria, Fusobacteria and Proteobacteria. At the genera level, the healthy human stomach is dominated by Prevotella, Streptococcus, Veillonella, Rothia and Haemophilus; however, the composition of the gastric microbiota is dynamic and affected by such factors as diet, drugs and diseases. The interaction between the pre-existing gastric microbiota and Helicobacter pylori infection might influence an individual’s risk of gastric disease, including gastric cancer. Conclusions The maintenance of bacterial homeostasis could be essential for the stomach’s health and highlights the chance for therapeutic interventions targeting the gastric microbiota, even if gastric pH, peristalsis and the mucus layer may prevent bacteria colonization; and the definition of gastric microbiota of the healthy stomach is still an ongoing challenging task. PMID:26137299

  7. Protective effect of hydrogen sulfide against cold restraint stress-induced gastric mucosal injury in rats.

    PubMed

    Aboubakr, Esam M; Taye, Ashraf; El-Moselhy, Mohamed A; Hassan, Magdy K

    2013-12-01

    Hydrogen sulfide (H2S) is an endogenous gaseous mediator plays a potential role in modulating gastric inflammatory responses. However, its putative protective role remains to be defined. The present study aimed to evaluate role of the exogenously released and endogenously synthesized H2S in cold restraint stress (CRS)-induced oxidative gastric damage in rats. Rats were restrained, and maintained at 4 °C for 3 h. The H2S donor, sodium hydrosulfide (NaHS) (60 μmol/kg) was injected intraperitoneally (i.p.) before CRS. Our results revealed that NaHS pretreatment significantly attenuated ulcer index, free and total acid output, and pepsin activity in gastric juice along with decreased gastric mucosal carbonyl content and reactive oxygen species production. This was accompanied by increased gastric juice pH and mucin concentration in addition to restoring the deficits in the gastric reduced glutathione, catalase as well as superoxide dismutase enzyme activities. NaHS pretreatment markedly reduced the serum level of tumor necrosis factor (TNF-α) and myeloperoxidase activity compared to CRS-non-treated. Moreover, NaHS preadministration significantly abrogated the inflammatory and the deleterious responses of gastric mucosa in CRS. The protective effects of H2S were confirmed by gastric histopathological examination. However, pretreatment with the H2S-synthesizing enzyme, cystathionine-gamma-lyase inhibitor, beta-cyano-L-alanine (50 mg/kg, i.p.) reversed the gastroprotection afforded by the endogenous H2S. Collectively, our results suggest that H2S can protect rat gastric mucosa against CRS-induced gastric ulceration possibly through mechanisms that involve anti-oxidant and anti-inflammatory actions alongside enhancement of gastric mucosal barrier and reduction in acid secretory parameters. PMID:23812778

  8. AN INVESTIGATION OF THE CHEMICAL STABILITY OF ARSENOSUGARS IN SIMULATED GASTRIC JUICE AND ACIDIC ENVIRONMENTS USING IC-ICP-MS AND IC-ESI-MS/MS

    EPA Science Inventory

    A more quantitative extraction of arsenic-containing compounds from seafood matrices is essential in developing better dietary exposure estimates. More quantitative extraction often implies a more chemically aggressive set of extraction conditions. However, these conditions may...

  9. Effects of genetics and environment on fatty acid stability in soybean seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although seed oil production and composition are genetically controlled, changes of oil level and oil composition across genotypes and environments such as drought and temperature were observed. The mechanisms of how genotypes interact with environment, affecting oil production and composition, are ...

  10. JB-9322, a new selective histamine H2-receptor antagonist with potent gastric mucosal protective properties.

    PubMed Central

    Palacios, B.; Montero, M. J.; Sevilla, M. A.; Román, L. S.

    1995-01-01

    1. JB-9322 is a selective histamine H2-receptor antagonist with gastric antisecretory activity and mucosal protective properties. 2. The affinity of JB-9322 for the guinea-pig atria histamine H2-receptor was approximately 2 times greater than that of ranitidine. 3. In vivo, the ID50 value for the inhibition of gastric acid secretion in pylorus-ligated rats was 5.28 mg kg-1 intraperitoneally. JB-9322 also dose-dependently inhibited gastric juice volume and pepsin secretion. In gastric lumen-perfused rats, intravenous injection of JB-9322 dose-dependently reduced histamine-, pentagastrin- and carbachol-stimulated gastric acid secretion. 4. JB-9322 showed antiulcer activity against aspirin and indomethacin-induced gastric lesions and was more potent than ranitidine. 5. JB-9322 effectively inhibited macroscopic gastric haemorrhagic lesions induced by ethanol. Intraperitoneal injection was effective in preventing the lesions as well as oral treatment. The oral ID50 value for these lesions was 1.33 mg kg-1. By contrast, ranitidine (50 mg kg-1) failed to reduce these lesions. In addition, the protective effect of JB-9322 was independent of prostaglandin synthesis. 6. These results indicate that JB-9322 is a new antiulcer drug that exerts a potent cytoprotective effect in addition to its gastric antisecretory activity. PMID:7647984

  11. Relationship of ECL cells and gastric neoplasia.

    PubMed Central

    Waldum, H. L.; Brenna, E.; Sandvik, A. K.

    1998-01-01

    The enterochromaffin-like (ECL) cell in the oxyntic mucosa has a key role in the regulation of gastric secretion since it synthesizes and releases the histamine regulating the acid secretion from the parietal cell. Gastrin is the main regulator of the ECL cell function and growth. Long-term hypergastrinemia induces ECL cell hyperplasia, and if continued, neoplasia. ECL cell carcinoids occur in man after long-term hypergastrinemia in conditions like pernicious anemia and gastrinoma. There is also accumulating evidence that a proportion of gastric carcinomas of the diffuse type is derived from the ECL cell. Furthermore, the ECL cell may, by producing substances with angiogenic effects (histamine and basic fibroblast growth factor), be particularly prone to develop malignant tumors. Although the general opinion is that gastrin itself has a direct effect on the oxyntic mucosal stem cell, it cannot be excluded that the general trophic effect of gastrin on the oxyntic mucosa is mediated by histamine or other substances from the ECL cell, and that the ECL cell, therefore, could play a role also in the tumorigenesis/carcinogenesis of gastric carcinomas of intestinal type. PMID:10461363

  12. Intrathoracic gastric perforation secondary to corrosive ingestion: a rare complication

    PubMed Central

    Varma Gunturi, Surya Ramachandra; Arora, Abhishek; Parmar, Abhijot

    2016-01-01

    This case report describes a rare and serious case of acid ingestion in a 50-year-old man who developed necrosis and perforation of gastric fundus and diaphragm with extension of air and fluid collection in the thorax. To the best of our knowledge, this complication has not been described so far in the literature. PMID:27190774

  13. Pathology and Genetics of Syndromic Gastric Polyps.

    PubMed

    Brosens, Lodewijk A A; Wood, Laura D; Offerhaus, G Johan; Arnold, Christina A; Lam-Himlin, Dora; Giardiello, Francis M; Montgomery, Elizabeth A

    2016-05-01

    Gastric polyps are found in 1% to 4% of patients undergoing gastroscopy. The vast majority are sporadic, but some gastric polyps indicate an underlying syndrome. Gastric polyps can manifest in each of the gastrointestinal polyposis syndromes, including the recently described gastric adenocarcinoma and proximal polyposis of the stomach syndrome. In addition, gastric polyps occur in Lynch syndrome and in a few rare conditions that are not primarily gastrointestinal. While some of these syndromes are clearly associated with an increased risk of gastric cancer, others are not. Interestingly, even in disorders with a well-established risk of gastric cancer, the neoplastic potential and the precursor status of these gastric polyps are not always clear. Although rare, recognition of syndromic gastric polyps is important for individual patient management. These conditions also serve as important models to study gastric homeostasis and gastric tumorigenesis. PMID:26721304

  14. Mouse gastric mucin: cloning and chromosomal localization.

    PubMed Central

    Shekels, L L; Lyftogt, C; Kieliszewski, M; Filie, J D; Kozak, C A; Ho, S B

    1995-01-01

    Mucins protect gastric epithelium by maintaining a favourable pH gradient and preventing autodigestion. The purpose of this study was to clone a mouse gastric mucin which would provide a foundation for analysis of mucin gene regulation. Mucin was purified from the glandular portion of gastric specimens and deglycosylated by HF solvolysis. Antibodies against native and deglycosylated mouse gastric mucin (MGM) were raised in chickens. Screening of a mouse stomach cDNA library with the anti-(deglycosylated MGM) antibody yielded partial clones containing a 48 bp tandem repeat and 768 bp of non-repetitive sequence. The 16-amino-acid tandem repeat has a consensus sequence of QTSSPNTGKTSTISTT with 25% serine and 38% threonine. The MGM tandem repeat sequence bears no similarity to previously identified mucins. The MGM non-repetitive region shares sequence similarity with human MUC5AC and, to a lesser extent, human MUC2 and rat intestinal mucin. Northern blot analysis reveals a polydisperse message beginning at 13.5 kb in mouse stomach with no expression in oesophagus, trachea, small intestine, large intestine, caecum, lung or kidney. Immunoreactivity of antibodies against deglycosylated MGM and against a synthetic MGM tandem repeat peptide was restricted to superficial mucous cells, antral glands and Brunner's glands in the pyloric-duodenal region. DNA analysis shows that MGM recognizes mouse and rat DNA but not hamster, rabbit or human DNA. The MGM gene maps to a site on mouse chromosome 7 homologous to the location of a human secretory mucin gene cluster on human chromosome 11p15. Due to sequence similarity and predominant expression in the stomach, the MGM gene may be considered a MUC5AC homologue and named Muc5ac. Images Figure 1 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:7487932

  15. Gastric secretion and its facilitation as related to gastric mucosal histamine

    PubMed Central

    Johansson, Irene; Lundell, L.; Rosengren, Elsa; Svensson, S. E.

    1972-01-01

    1. In conscious rats provided with Pavlov or Heidenhain pouches the acid and pepsin responses to vagal stimulation, or infusions of gastrin, histamine, methacholine, and to various combinations of these stimulants have been established. The concomitant mobilization and increased formation of gastric mucosal histamine have also been examined. 2. Histamine evoked graded acid responses in the Pavlov and Heidenhain pouches. The innervated pouch was more sensitive to histamine than the denervated. Stimulation of pepsin secretion was apparent only in the Heidenhain pouch. 3. The acid response to vagal stimulation evoked by 2-deoxy-D-glucose was facilitated by infusion of histamine, but not that of pepsin, the secretion of which was depressed. 4. Acid secretion in response to graded infusion of methacholine was enhanced by background infusions of histamine in subthreshold, sub-maximal and maximal dosages. 5. The acid response to vagal stimulation was enhanced by a background infusion of gastrin, but not that of pepsin, the secretion of which was depressed. 6. A background infusion of a large dose of histamine depressed the maximal acid response to gastrin in both types of pouches. 7. Administration of histamine restrained the accelerating effect of gastrin on histidine decarboxylase activity, probably by a feed-back coupling. 8. The increase in gastric mucosal histamine, as reflected in its urinary excretion, in response to gastrin infusion was enhanced by vagal stimulation. 9. The amounts of histamine that can be mobilized and newly formed in the gastric mucosa have been evaluated and found to be fully adequate for efficient stimulation of the parietal cell. PMID:4563731

  16. Biological and chemical characteristics of the coral gastric cavity

    NASA Astrophysics Data System (ADS)

    Agostini, S.; Suzuki, Y.; Higuchi, T.; Casareto, B. E.; Yoshinaga, K.; Nakano, Y.; Fujimura, H.

    2012-03-01

    All corals have a common structure: two tissue layers enclose a lumen, which forms the gastric cavity. Few studies have described the processes occurring inside the gastric cavity and its chemical and biological characteristics. Here, we show that the coral gastric cavity has distinct chemical characteristics with respect to dissolved O2, pH, alkalinity, and nutrients (vitamin B12, nitrate, nitrite, ammonium, and phosphate) and also harbors a distinct bacterial community. From these results, the gastric cavity can be described as a semi-closed sub-environment within the coral. Dissolved O2 shows very low constant concentrations in the deepest parts of the cavity, creating a compartmentalized, anoxic environment. The pH is lower in the cavity than in the surrounding water and, like alkalinity, shows day/night variations different from those of the surrounding water. Nutrient concentrations in the cavity are greater than the concentrations found in reef waters, especially for phosphate and vitamin B12. The source of these nutrients may be internal production by symbiotic bacteria and/or the remineralization of organic matter ingested or produced by the corals. The importance of the bacteria inhabiting the gastric cavity is supported by the finding of a high bacterial abundance and a specific bacterial community with affiliation to bacteria found in other corals and in the guts of other organisms. The findings presented here open a new area of research that may help us to understand the processes that maintain coral health.

  17. The Role of Sonic Hedgehog Reemergence During Gastric Cancer

    PubMed Central

    Martin, Jason; Donnelly, Jessica M.; Houghton, JeanMarie

    2016-01-01

    Sonic Hedgehog (Shh) signaling has been extensively studied for its role in developmental biology and cancer biology. The association between Shh and cancer development in general is well established but the functional role of Shh in the development and progression of gastric cancer specifically is largely unknown. Bone marrow-derived stem cells, specifically mesenchymal stem cells (MSCs) infiltrate and engraft into the gastric mucosa in response to the chronic inflammatory environment of Helicobacter infection. In this review, MSC infiltration and changes in the cytokine and cellular profiles of later-stage chronic environments will be tied into their interactions with the Shh pathway. We will discuss how these changes shape tumorigenesis and tumor progression in the gastric mucosa. The current review focuses on the Shh signaling pathway and its role in the development of gastric cancer, specifically in response to Helicobacter pylori infection. We follow with an in-depth discussion of the regulation of the Hedgehog pathway during acute and chronic gastric inflammation with a focus on signaling within the MSC compartment. PMID:20437100

  18. Ammonia activates pacC and patulin accumulation in an acidic environment during apple colonization by Penicillium expansum.

    PubMed

    Barad, Shiri; Espeso, Eduardo A; Sherman, Amir; Prusky, Dov

    2016-06-01

    Penicillium expansum, the causal agent of blue mould rot, causes severe post-harvest fruit maceration simultaneously with the secretion of d-gluconic acid (GLA) and the mycotoxin patulin in colonized tissue. The factor(s) inducing patulin biosynthesis during colonization of the host acidic environment is unclear. During the colonization of apple fruit in vivo and growth in culture, P. expansum secretes pH-modulating GLA and ammonia. Although patulin and its possible opportunistic precursor GLA accumulate together during fungal development, ammonia is detected on the colonized tissue's leading edge and after extended culture, close to patulin accumulation. Here, we demonstrate ammonia-induced transcript activation of the global pH modulator PacC and patulin accumulation in the presence of GLA by: (i) direct exogenous treatment of P. expansum growing on solid medium; (ii) direct exogenous treatment on colonized apple tissue; (iii) growth under self-ammonia production conditions with limited carbon; and (iv) analysis of the transcriptional response to ammonia of the patulin biosynthesis cluster. Ammonia induced patulin accumulation concurrently with the transcript activation of pacC and patulin biosynthesis cluster genes, indicating the regulatory effect of ammonia on pacC transcript expression under acidic conditions. Electrophoretic mobility shift assays using P. expansum PacC and antibodies to the different cleaved proteins showed that PacC is not protected against proteolytic signalling at pH 4.5 relative to pH 7.0, but NH4 addition did not further enhance its proteolytic cleavage. Ammonia enhanced the activation of palF transcript in the Pal pathway under acidic conditions. Ammonia accumulation in the host environment by the pathogen under acidic pH may be a regulatory cue for pacC activation, towards the accumulation of secondary metabolites, such as patulin. PMID:26420024

  19. Linoleic acid permeabilizes gastric epithelial cells by increasing connexin 43 levels in the cell membrane via a GPR40- and Akt-dependent mechanism.

    PubMed

    Puebla, Carlos; Cisterna, Bruno A; Salas, Daniela P; Delgado-López, Fernando; Lampe, Paul D; Sáez, Juan C

    2016-05-01

    Linoleic acid (LA) is known to activate G-protein coupled receptors and connexin hemichannels (Cx HCs) but possible interlinks between these two responses remain unexplored. Here, we evaluated the mechanism of action of LA on the membrane permeability mediated by Cx HCs in MKN28 cells. These cells were found to express connexins, GPR40, GPR120, and CD36 receptors. The Cx HC activity of these cells increased after 5 min of treatment with LA or GW9508, an agonist of GPR40/GPR120; or exposure to extracellular divalent cation-free solution (DCFS), known to increase the open probability of Cx HCs, yields an immediate increase in Cx HC activity of similar intensity and additive with LA-induced change. Treatment with a CD36 blocker or transfection with siRNA-GPR120 maintains the LA-induced Cx HC activity. However, cells transfected with siRNA-GPR40 did not show LA-induced Cx HC activity but activity was increased upon exposure to DCFS, confirming the presence of activatable Cx HCs in the cell membrane. Treatment with AKTi (Akt inhibitor) abrogated the LA-induced Cx HC activity. In HeLa cells transfected with Cx43 (HeLa-Cx43), LA induced phosphorylation of surface Cx43 at serine 373 (S373), site for Akt phosphorylation. HeLa-Cx43 but not HeLa-Cx43 cells with a S373A mutation showed a LA-induced Cx HC activity directly related to an increase in cell surface Cx43 levels. Thus, the increase in membrane permeability induced by LA is mediated by an intracellular signaling pathway activated by GPR40 that leads to an increase in membrane levels of Cx43 phosphorylated at serine 373 via Akt. PMID:26869446

  20. Gene transcription patterns of pH- and salt-stressed Listeria monocytogenes cells in simulated gastric and pancreatic conditions.

    PubMed

    Mataragas, Marios; Greppi, Anna; Rantsiou, Kalliopi; Cocolin, Luca

    2014-02-01

    A Listeria monocytogenes subgenomic array, targeting 54 genes involved in the adhesion, adaptation, intracellular life cycle, invasion, and regulation of the infection cycle was used to investigate the gene expression patterns of acid- and salt-stressed Listeria cells after exposure to conditions similar to those in gastric and pancreatic fluids. Three L. monocytogenes strains, one laboratory reference strain (EGDe) and two food isolates (wild strain 12 isolated from milk and wild strain 3 isolated from fermented sausage), were used during the studies. Differences in the expressed genes were observed between the gastric and pancreatic treatments and also between the serotypes. Increased transcripts were observed of the genes belonging to the adaptation and regulation group for serotype 4b (strain 12) and to the invasion and regulation group for serotype 1/2a (strain EGDe). Interestingly, no significantly differentially expressed genes were found for serotype 3c (strain 3) in most cases. The genes related to adaptation (serotype 1/2a) and to intracellular life cycle and invasion (serotype 4b) were down-regulated in order to cope with the hostile environment of the gastric and pancreatic fluids. These findings may provide experimental evidence for the dominance of serotypes 1/2a and 4b in clinical cases of listeriosis and for the sporadic occurrence of serotype 3c. PMID:24490919

  1. PRODUCTION OF EXTRACELLULAR NUCLEIC ACIDS BY GENETICALLY ALTERED BACTERIA IN AQUATIC-ENVIRONMENT MICROCOSMS

    EPA Science Inventory

    Factors which affect the production of extracellular DNA by genetically altered strains of Escherichia coli, Pseudomonas aeruginosa, pseudomonas cepacia, and Bradyrhizobium japonicum in aquatic environments were investigated. he presence or absence of the ambient microbial commun...

  2. [Helicobacter pylori and gastric ulcer].

    PubMed

    Maaroos, H I

    1994-01-01

    In connection with longitudinal ulcer studies and the demonstration of Helicobacter pylori as the main cause of chronic gastritis, new aspects of gastric ulcer recurrences and healing become evident. This extends the possibilities to prognosticate the course of gastric ulcer and to use more effective treatment. PMID:7937016

  3. The diurnal variation in urine acidification differs between normal individuals and uric acid stone formers

    PubMed Central

    Cameron, Mary Ann; Maalouf, Naim M.; Poindexter, John; Adams-Huet, Beverley; Sakhaee, Khashayar; Moe, Orson W.

    2012-01-01

    Many biologic functions follow circadian rhythms driven by internal and external cues that synchronize and coordinate organ physiology to diurnal changes in the environment and behavior. Urinary acid-base parameters follow diurnal patterns and it is thought these changes are due to periodic surges in gastric acid secretion. Abnormal urine pH is a risk factor for specific types of nephrolithiasis and uric acid stones are typical of excessively low urine pH. Here we placed 9 healthy volunteers and 10 uric acid stone formers on fixed metabolic diets to study the diurnal pattern of urinary acidification. All showed clear diurnal trends in urinary acidification but none of the patterns were affected by inhibitors of the gastric proton pump. Uric acid stone formers had similar patterns of change through the day but their urine pH was always lower compared to healthy volunteers. Uric acid stone formers excreted more acid (normalized to acid ingestion) with the excess excreted primarily as titratable acid rather than ammonium. Urine base excretion was also lower in uric acid stone formers (normalized to base ingestion) along with lower plasma bicarbonate concentrations during part of the day. Thus, increased net acid presentation to the kidney and the preferential use of buffers, other than ammonium, result in much higher concentrations of un-dissociated uric acid throughout the day and consequently an increased risk of uric acid stones. PMID:22297671

  4. A New Green Ionic Liquid-Based Corrosion Inhibitor for Steel in Acidic Environments.

    PubMed

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; Ezzat, Abdel Rahman O

    2015-01-01

    This work examines the use of new hydrophobic ionic liquid derivatives, namely octadecylammonium tosylate (ODA-TS) and oleylammonium tosylate (OA-TS) for corrosion protection of steel in 1 M hydrochloric acid solution. Their chemical structures were determined from NMR analyses. The surface activity characteristics of the prepared ODA-TS and OA-TS were evaluated from conductance, surface tension and contact angle measurements. The data indicate the presence of a double bond in the chemical structure of OA-TS modified its surface activity parameters. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) measurements, scanning electron microscope (SEM), Energy dispersive X-rays (EDX) analysis and contact angle measurements were utilized to investigate the corrosion protection performance of ODA-TS and OA-TS on steel in acidic solution. The OA-TS and ODA-TS compounds showed good protection performance in acidic chloride solution due to formation of an inhibitive film on the steel surface. PMID:26091073

  5. NEXAFS and XPS of p-Aminobenzoic Acid Polymorphs: The Influence of Local Environment

    NASA Astrophysics Data System (ADS)

    Stevens, J. S.; Gainar, A.; Jaye, C.; Fischer, D. A.; Schroeder, S. L. M.

    2016-05-01

    Nitrogen K-edge XPS and NEXAFS of the two polymorphic forms of para- aminobenzoic acid (PABA) are significantly different reflecting variation in hydrogen bonding. Alteration in hydrogen bonding at the amino group leads to a shift to high energy for both the XPS N 1s core level and the 3π* NEXAFS resonance with β-PABA. Participation of the amine group in the aromatic system causes the 1π* resonance to be sensitive to the nature of the intermolecular bonding at the para-carboxylic acid group, and a shift to low energy for α- PABA is observed due to hydrogen-bonded carboxylic acid dimer formation. FEFF calculations also successfully reproduce both the energy and intensity variations observed for the σ* shape resonance associated with the C-N bond, with the majority of the decrease in energy observed for b-PABA arising from the longer C-N bond.

  6. TESTING OF 304L STAINLESS STEEL IN NITRIC ACID ENVIRONMENTS WITH FLUORIDES AND CHLORIDES

    SciTech Connect

    Mickalonis, J.

    2010-10-04

    Impure radioactive material processed in nitric acid solutions resulted in the presence of chlorides in a dissolver fabricated from 304L stainless steel. An experimental program was conducted to study the effects of chloride in nitric acid/fluoride solutions on the corrosion of 304L stainless steel. The test variables included temperature (80, 95, and 110 C) and the concentrations of nitric acid (6, 12, and 14 M), fluoride (0.01, 0.1, and 0.2 M) and chloride (100, 350, 1000, and 2000 ppm). The impact of welding was also investigated. Results showed that the chloride concentration alone was not a dominant variable affecting the corrosion, but rather the interaction of chloride with fluoride significantly affected corrosion.

  7. Secondary sulfate minerals associated with acid drainage in the eastern US: Recycling of metals and acidity in surficial environments

    USGS Publications Warehouse

    Hammarstrom, J.M.; Seal, R.R., II; Meier, A.L.; Kornfeld, J.M.

    2005-01-01

    spells. Despite the relatively humid climate of the eastern United States, where precipitation typically exceeds evaporation, salts form intermittently in open areas, persist in protected areas when temperature and relative humidity are appropriate, and contribute to metal loadings and acidity in surface waters upon dissolution, thereby causing short-term perturbations in water quality.

  8. Variations of Weight Loss Following Gastric Bypass and Gastric Band

    PubMed Central

    Puzziferri, Nancy; Nakonezny, Paul A.; Livingston, Edward H.; Carmody, Thomas J.; Provost, David A.; Rush, A. John

    2016-01-01

    Objective To compare and describe the weight loss outcomes from gastric bypass and gastric band so as to define the variation of excess weight loss (EWL) among individual patients, the time to onset of effect, and the durability of weight loss in severely obese adults. Summary Background Data Gastric bypass and gastric band are the most common operations for obesity performed in the United States, but few reports have compared these 2 procedures. Methods Patients (N = 1733, aged 18–65 years) met National Institutes of Health criteria for obesity surgery and underwent either gastric bypass or gastric band between March 1997 and November 2006. The selection of bypass versus band was based on patient/surgeon discussion. The evaluable sample consisted of 1518 patients. The percentage of EWL was assessed over 2 years. Successful weight loss was defined a priori as ≥40% EWL in each of four 6-month postoperative measurement periods. The analyses included a mixed model and generalized estimating equation (GEE) model with repeated measures. Odds ratios and descriptive analyses were also provided. Results Gastric bypass was associated with less individual variation in weight loss than gastric band. Both procedures were associated with a significant EWL benefit (Treatment Group effect P < 0.0001), but they differed in terms of time to effect (Treatment Group × Period interaction effect P < 0.0001). The mean EWL for gastric bypass was greater at each measurement period (6, 12, 18, 24 months) compared with gastric band (P < 0.0001). Furthermore, at each of the postoperative measurement periods within each treatment group (bypass and band), the mean EWL was greater for those who had preoperative body mass index (BMI) ≤50 kg/m2 than for those who had preoperative BMI >50 kg/m2 (P < 0.0001). Gastric bypass was consistently associated with a greater likelihood of at least a 40% EWL in each of the 6-month postoperative measurement periods (GEE, P < 0.0001). The odds ratio

  9. Metal Interactions with Microbial Biofilms in Acidic and Neutral pH Environments

    PubMed Central

    Ferris, F. G.; Schultze, S.; Witten, T. C.; Fyfe, W. S.; Beveridge, T. J.

    1989-01-01

    Microbial biofilms were grown on strips of epoxy-impregnated filter paper submerged at four sites in water contaminated with metals from mine wastes. At two sample stations, the water was acidic (pH 3.1); the other sites were in a lake restored to a near neutral pH level by application of a crushed limestone slurry. During a 17-week study period, planktonic bacterial counts increased from 101 to 103 CFU/ml at all sites. Biofilm counts increased rapidly over the first 5 weeks and then leveled to 104 CFU/cm2 in the neutral pH system and 103 CFU/cm2 at the acidic sites. In each case, the biofilms bound Mn, Fe, Ni, and Cu in excess of the amounts adsorbed by control strips covered with nylon filters (pore size, 0.22 μm) to exclude microbial growth; Co bound under neutral conditions but not under acidic conditions. Conditional adsorption capacity constants, obtained graphically from the data, showed that biofilm metal uptake at a neutral pH level was enhanced by up to 12 orders of magnitude over acidic conditions. Similarly, adsorption strength values were usually higher at elevated pH levels. In thin sections of the biofilms, encapsulated bacterial cells were commonly found enmeshed together in microcolonies. The extracellular polymers often contained iron oxide precipitates which generated weak electron diffraction patterns with characteristic reflections for ferrihydrite (Fe2O3 · H2O) at d equaling 0.15 and 0.25 nm. At neutral pH levels, these deposits incorporated trace amounts of Si and exhibited a granular morphology, whereas acicular crystalloids containing S developed under acidic conditions. Images PMID:16347914

  10. Primary Gastric Chorioadenocarcinoma.

    PubMed

    Baraka, Bahaaeldin A; Al Kharusi, Suad S; Al Bahrani, Bassim J; Bhathagar, Gunmala

    2016-09-01

    Primary gastric chorioadenocarcinoma (PGC) is a rare and rapidly invasive tumor. Choriocarcinoma is usually known to be of endometrial origin and gestational; however, it has been reported in other extragenital organs, such as the gall bladder, prostate, lung, liver, and the gastrointestinal tract. Human chorionic gonadotropin related neoplasms of the stomach are seldom discussed in the literature. We report a case of PGC in a 56-year-old man treated with a standard non-gestational choriocarcinoma chemotherapy regimen, EMA/CO (etoposide, methotrexate, actinomycin D, cyclophosphamide, vincristine), with a complete response and good tolerability. PMID:27602194

  11. Primary Gastric Chorioadenocarcinoma

    PubMed Central

    Baraka, Bahaaeldin A.; Al Kharusi, Suad S.; Al Bahrani, Bassim J.; Bhathagar, Gunmala

    2016-01-01

    Primary gastric chorioadenocarcinoma (PGC) is a rare and rapidly invasive tumor. Choriocarcinoma is usually known to be of endometrial origin and gestational; however, it has been reported in other extragenital organs, such as the gall bladder, prostate, lung, liver, and the gastrointestinal tract. Human chorionic gonadotropin related neoplasms of the stomach are seldom discussed in the literature. We report a case of PGC in a 56-year-old man treated with a standard non-gestational choriocarcinoma chemotherapy regimen, EMA/CO (etoposide, methotrexate, actinomycin D, cyclophosphamide, vincristine), with a complete response and good tolerability. PMID:27602194

  12. The effect of gastric secretion on gastric physiology and emptying in the fasted and fed state assessed by magnetic resonance imaging.

    PubMed

    Goetze, O; Treier, R; Fox, M; Steingoetter, A; Fried, M; Boesiger, P; Schwizer, W

    2009-07-01

    Conventional measurement of gastric secretion is invasive and cannot assess the intra-gastric distribution of gastric contents or the effects of secretion on gastric function. This study assessed the effect of gastric secretion on gastric volume responses and emptying (GE) using a validated fast T(1) mapping magnetic resonance imaging (MRI) technique. Twelve healthy participants were studied in the fasted state and after 200 kcal Gadolinium-DOTA labelled glucose meal during intravenous infusion of pentagastrin or placebo in double-blind, randomized order. Total gastric volume (TGV) and gastric content volume (GCV) was assessed by MRI volume scans and secretion by fast T(1) mapping. Data was described by the kappa-coefficient (volume change after meal ingestion), by GE half time (T(50)) and maximal GE rate (GER(max)) derived all from a GE model. Pentagastrin increased GCV and TGV compared to placebo [kappa(GCV):1.6 +/- 0.1 vs 0.6 +/- 0.1; kappa(TGV): 1.6 +/- 0.1 vs 0.7 +/- 0.1; P < 0.001]. T(1) maps revealed a secretion layer above the meal, the volume of which was associated with kappa (R(2) = 83%, P < 0.001). TGV and GCV change were similar in both conditions (kappa; P = ns). T(50) was higher for pentagastrin than for placebo (84 +/- 7 vs 56 +/- 4min, P < 0.001); however, GER(max) was similar (5.9 +/- 0.6 vs 4.9 +/- 0.4 mL min(-1), P = ns). This study shows volume and distribution of gastric secretion can be quantified in-vivo by non-invasive MRI T(1) mapping. Increased GCV drove TGV accommodation without evidence of a direct effect of pentagastrin or excess acid on gastric function. Secretion increases GCV thus prolongs GE as assessed by T(50); however, GE rate is unchanged. PMID:19344341

  13. Gastric lipase: localization of the enzyme in the stomach

    SciTech Connect

    DeNigris, S.J.; Hamosh, M.; Hamosh, P.; Kasbekar, D.K.

    1986-03-05

    Isolated gastric glands prepared from human and rabbit stomach secrete lipase in response to secretagogues. They have investigated the localization of this enzyme in three species (rabbit, baboon, guinea pig). Gastric mucosa was sampled from the cardia (C), fundus-smooth (FS), fundus-ruggae (FR) and the antral area (A). Lipase activity was measured in mucosal homogenates using /sup 3/H-triolein as substrate and is expressed in units (U) = nmols free fatty acid released/min/mg wet weight. The localization of lipase is compared with that of pepsin (measured by hydrolysis of 2% hemoglobin at pH 1.8 and expressed in I.U.). Lipase is localized in a well defined area in the rabbit and is diffusely distributed in both guinea pig and baboon. The distribution of lipase and pepsin containing cells differs in all three species. The cellular origin of gastric lipase remains to be determined.

  14. Gastric erosions induced by analgesic drug mixtures in the rat.

    PubMed

    Seegers, A J; Jager, L P; Van Noordwijk, J

    1978-02-01

    Gastric erosions after oral administration of analgesics separately and in admixture have been examined in adult rats. After administration of acetylsalicylic acid (aspirin), phenacetin, paracetamol and caffeine as single drugs, gastric erosions were only observed with aspirin. The combination of aspirin with phenacetin did not change, that of aspirin with caffeine significantly increased, and aspirin with paracetamol significantly decreased the incidence of gastric lesions compared with aspirin alone. The results for aspirin with paracetamol did not differ from those for the vehicle. Addition of caffeine to the combination of aspirin and phenacetin caused a significant increase in erosions, but when given with aspirin and paracetamol no erosions occurred. The mechanisms underlying the effects of these drugs on aspirin-induced erosions are discussed. PMID:24109

  15. N-nitroso compounds, genotoxins and their precursors in gastric juice from humans with and without precancerous lesions of the stomach.

    PubMed

    Pignatelli, B; Malaveille, C; Chen, C; Hautefeuille, A; Thuillier, P; Muñoz, N; Moulinier, B; Berger, F; De Montclos, H; Ohshima, H

    1991-01-01

    We are investigating the interrelationships between levels of total N-nitroso compounds (NOC), genotoxic activity (both before and after nitrosation), degree of bacterial colonization in gastric juice and degree of severity or absence of precancerous lesions of the stomach. The mean level of constitutive total NOC in gastric juice was similar in the different groups of patients, but it was higher in acidic gastric juice (n = 30) than in gastric juice at pH greater than 4.5 (n = 12). Acid-catalysed nitrosation of gastric juice in vitro increased the concentration of total NOC by up to several thousand fold, to a maximum of 1330 mumol/l. Genotoxicity, expressed as SOS-inducing potency per 100 microliters of gastric juice was measurable in only 20% of gastric juice samples tested. After acid-catalysed nitrosation, however, all samples showed genotoxic activity, the mean SOS-inducing potency being four to seven times greater than the corresponding constitutive value. There was no association between the mean SOS-inducing potency of gastric juice and the severity of precancerous lesions. The mean SOS-inducing potency of neutral or basic gastric juice was slightly greater than that of acidic samples. In a kinetic study on N-nitrosation of gastric juice in vitro, a mixture of amino and amido substrates was nitrosated; both qualitative and quantitative individual differences in nitrosatable substrates in gastric juice were seen. Fractionation of acidic, neutral and basic nitrosated gastric juice samples revealed a preponderance of nonvolatile, unknown NOC with varying polarities. The results of our study suggest that only pH determines the nature and level of precursors of NOC and of nitrosation-dependent genotoxins in gastric juice. PMID:1855844

  16. The influence of acute or chronic nicotine treatment on ethanol-induced gastric mucosal damage in rats.

    PubMed

    Cho, C H; Chen, B W; Hui, W M; Lam, S K

    1990-01-01

    The influences of acute or chronic nicotine pretreatment on ethanol-induced changes on gastric secretion, mucosal blood flow (GMBF), and glandular mucosal damage were studied in anesthetized rats. Ethanol administration decreased gastric acid secretion and GMBF, which were accompanied by a marked increase in gastric mucosal damage. Acute nicotine incubation 2 or 4 mg dose-dependently elevated both the titratable acid in the luminal solution and the gastric secretory volume; it also prevented the depressive action on GMBF and gastric mucosal damage in ethanol-treated animals. Chronic nicotine treatment for 10 days reduced the inhibitory action of ethanol on gastric acid secretion; the higher dose (25 micrograms/ml drinking water) potentiated the decrease of GMBF and the ulcerogenic property of ethanol. However, chronic treatment with the lower dose (5 micrograms/ml drinking water) had the opposite effects; it also markedly increased the gastric secretory volume. It is concluded that acute nicotine pretreatment elevates, whereas chronic nicotine pretreatment differentially affects GMBF. These effects could account for their protective or preventive actions on ethanol ulceration. The increase in nonacid gastric secretory volume by nicotine could partially explain its antiulcer effect. Furthermore, the acid secretory state of the stomach appears unrelated to the ulcerogenic property of ethanol. PMID:2295286

  17. The influence of chronic or acute nicotine pretreatment on ethanol-induced gastric ulceration in the rat.

    PubMed

    Wong, S H; Ogle, C W; Cho, C H

    1986-07-01

    The effects in rats of chronic or acute nicotine pretreatment were studied on three gastric parameters: ethanol-induced ulceration, gastric wall mucus content and gastric acid secretion, under basal or histamine-stimulated conditions. Oral administration of ethanol (40%, 10 ml kg-1) depleted gastric wall mucus and produced ulceration in the gastric glandular mucosa. Ten-day nicotine pretreatment (15 or 25 micrograms ml-1 drinking water) worsened the adverse effects of ethanol on mucosal ulceration and mucus content, potentiated the gastric secretory action of histamine, but did not affect basal acid secretion. Single oral doses of nicotine (2 or 4 mg kg-1, given 1 h beforehand) prevented ulceration and mucus depletion in ethanol-treated animals; however, they did not influence either basal or histamine-stimulated gastric acid output. It is concluded that chronic nicotine administration aggravates ethanol ulceration, possibly by decreasing gastric wall mucus content and sensitizing the stomach to the acid secretory action of histamine. On the other hand, an acute oral dose of nicotine preserves the mucus content and prevents ethanol-induced ulcer formation. PMID:2427681

  18. Detection of trace amino acid biomarkers in ice from extreme environments with the Mars Organic Analyzer

    NASA Astrophysics Data System (ADS)

    Jayarajah, Christine; Jayarajah, Christine; Botta, Oliver; Aubrey, Andrew; Parker, Eric; Bada, Jeffrey; Mathies, Richard

    A portable microfabricated capillary electrophoresis (CE) system named the Mars Organic Analyzer (MOA) has been developed to analyze fluorescently-labeled biomarkers including amino acids, amines, nucleobases, and amino sugars with the goal of life detection on Mars (1,2). This system consists of a multilayer microfabricated glass wafer containing electrophoresis channels as well as microfluidic valves and pumps for sample manipulation, a confocal laser excitation and fluorescence detection system, and integrated CE power supplies. The MOA has been successfully field tested in the Panoche Valley, CA and in the Atacama Desert, Chile, detecting amino acids at the ppb levels (3). In addition, this technology has been shown to be effective in screening the formation of biogenic amines during fermentation (4). The MOA is a part of the Urey instrument package that has been selected for the 2013 European ExoMars mission by ESA. The identification of recent gully erosion sites, observations of ice on and beneath the surface of Mars, and the discovery of large reservoirs of sub-surface ice on Mars point to water-ice as an important target for astrobiological analyses (5). In addition, the ice moons Europa and Enceladus are of astrobiological interest due to the possibility that they may contain liquid water under their ice crusts. Consequently, we explore here the use of the MOA instrument for the analysis of amino acids in polar ice samples. Soil extracts as well as concentrated icecore samples tend to be highly saline and inhomogeneous. Furthermore, brine pockets in ice form potential refugia for extant extra-terrestrial life, rendering near surface ice a key target for the search for a record of past life on the planet (6). Therefore, we have determined the effect of salinity on sample injection parameters in ice-core samples retrieved from Greenland. The amino acids valine, alanine/serine, glycine, glutamic acid, and aspartic acid were found in the parts

  19. Evaluation of a Porcine Gastric Mucin and RNase A Assay for the Discrimination of Infectious and Non-infectious GI.1 and GII.4 Norovirus Following Thermal, Ethanol, or Levulinic Acid Plus Sodium Dodecyl Sulfate Treatments.

    PubMed

    Afolayan, Olamide T; Webb, Cathy C; Cannon, Jennifer L

    2016-03-01

    Human noroviruses (NoVs) are a major source of foodborne illnesses worldwide. Since human NoVs cannot be cultured in vitro, methods that discriminate infectious from non-infectious NoVs are needed. The purpose of this study was to evaluate binding of NoV genotypes GI.1 and GII.4 to histo-blood group antigens expressed in porcine gastric mucin (PGM) as a surrogate for detecting infectious virus following thermal (99 °C/5 min), 70% ethanol or 0.5% levulinic acid (LV) plus 0.01 or 0.1% sodium dodecyl sulfate (SDS) sanitizer treatments and to determine the limit of detection of GI.1 and GII.4 binding to PGM. Treated and control virus samples were applied to 96-well plates coated with 1 µg/ml PGM followed by RNase A (5 ng/µl) treatment for degradation of exposed RNA. Average log genome copies per ml (gc/ml) reductions and relative differences (RD) in quantification cycle (Cq) values after thermal treatment were 1.77/5.62 and 1.71/7.25 (RNase A) and 1.73/5.50 and 1.56/6.58 (no RNase A) for GI.1 and GII.4, respectively. Treatment of NoVs with 70% EtOH resulted in 0.05/0.16 (GI.1) and 3.54/10.19 (GII.4) log reductions in gc/ml and average RD in Cq value, respectively. LV (0.5%) combined with 0.1 % SDS provided a greater decrease of GI.1 and GII.4 NoVs with 8.97 and 8.13 average RD in Cq values obtained, respectively than 0.5% LV/0.01 % SDS. Virus recovery after PGM binding was variable with GII.4 > GI.1. PGM binding is a promising surrogate for identifying infectious and non-infectious NoVs after capsid destruction, however, results vary depending on virus strain and inactivation method. PMID:26514820

  20. Gastric metaplasia and duodenal ulcer disease in children infected by Helicobacter pylori.

    PubMed Central

    Gormally, S M; Kierce, B M; Daly, L E; Bourke, B; Carroll, R; Durnin, M T; Drumm, B

    1996-01-01

    BACKGROUND--Helicobacter pylori infection of the gastric mucosa is vital in the pathogenesis of duodenal ulcer disease. H pylori will only colonise gastric epithelium and its association with duodenal disease is therefore not easily explained. AIMS--To determine if gastric metaplasia in the duodenum increases the risk of duodenal ulcer disease in children infected with H pylori. PATIENTS--All children undergoing upper endoscopy over a 20 month period in a children's hospital in Ireland. METHODS--Two biopsy specimens were obtained from the antral mucosa and two from the first part of the duodenum. One antral biopsy specimen was used in a rapid urease test (Clo Test). Biopsy sections were stained with haematoxylin and eosin and also with cresyl violet for identification of H pylori. Periodic acid Schiff (PAS) stain was performed to identify areas of gastric metaplasia. RESULTS--Gastric and duodenal biopsy specimens were obtained from 148 patients (M:F 1:2:1). Twenty five children (17%) had H pylori positive gastritis. Thirty four children (23%) had gastric metaplasia in the duodenum. Nine per cent of children under the age of 8 years had gastric metaplasia compared with 38% in those 12 years of age or over (p < 0.005). Seven children had duodenal ulcer disease. Gastric metaplasia was present in six of seven (86%) children with duodenal ulcer disease compared with 28 of 141 (20%) without ulceration (p < 0.001). While both H pylori and gastric metaplasia were each significant risk factors for duodenal ulcer disease, the combined presence of both factors was associated with a pronounced increase in duodenal ulcer disease. Duodenal ulcer disease occurred in over 50% of children with both H pylori infection and gastric metaplasia. In contrast duodenal disease did not occur in children (0 of 100) when both were absent. CONCLUSION--The presence of gastric metaplasia in the duodenum is the major risk factor for duodenal ulcer disease in patients colonised by H pylori. PMID

  1. Geomicrobiology associated with formation of Fe-rich accretions in an extreme acidic environment

    NASA Astrophysics Data System (ADS)

    Rodrigues, L.; Valente, T. M.; Foing, B. H.; Davies, G. R.; Correia, A.; Alves, A.

    2012-09-01

    The abandoned mine of Valdarcas (north of Portugal) includes a small effluent channel associated with a permanent strong acid mine drainage (AMD) (average pH= 3.0), where Fe-rich tubular and spherical macro concretions have been formed and can be observed in situ. Results from biological analysis demonstrate a high phylogenetic diversity within Bacteria domain and Fungi kingdom, and less diversity for the Archaea domain.

  2. Proximal gastric vagotomy. Comparison between open and laparoscopic methods in the canine model.

    PubMed Central

    Kollmorgen, C F; Gunes, S; Donohue, J H; Thompson, G B; Sarr, M G

    1996-01-01

    OBJECTIVE. The authors compared open and laparoscopic proximal gastric vagotomies for efficacy of acid reduction and preservation of gastric emptying. SUMMARY BACKGROUND DATA. Laparoscopic methods have been used to perform vagotomy in patients with duodenal ulcer; however, no direct comparisons are available of laparoscopic and open surgical procedures regarding acid reduction and gastric emptying. METHODS. Thirty-one consecutive dogs were randomized to open proximal gastric vagotomy (OPGV; n = 11), laparoscopic anterior seromyotomy and posterior truncal vagotomy (ASPTV; n = 10), or laparoscopic proximal gastric vagotomy (LPGV; n = 10). Intraoperative endoscopic Congo red testing assured complete vagotomy. Basal acid output (BAO) and maximal acid output (MAO) during pentagastrin and insulin-induced hypoglycemia were measured with marker dilution techniques, and gastric emptying was assessed with radionuclide-labelled solid and liquid markers before and 5 weeks after operation. RESULTS. Operative time (mean +/- standard error of the mean) for OPGV was shorter compared with ASPTV and LPGV (86 +/- 7 minutes vs. 124 +/- 7 minutes and 115 +/- 7 minutes; p < 0.002). Postoperative BAO did not decrease in any group. Open proximal gastric vagotomy and LPGV, but not ASPTV, decreased MAO (p < 0.05); (after pentagastrin, OPGV from 26.4 +/- 1.7 mEq/hour to 11.3 +/- 0.1 mEq/hour, LPGV from 21.4 +/- 1.0 mEq/hour to 6.4 +/- 0.5 mEq/hour; after insulin-induced hypoglycemia, OPGV from 9.9 +/- 0.5 mEq/hour to 2.2 +/- 0.3 mEq/hour, LPGV from 7.9 +/- 0.5 mEq/hour to 1.9 +/- 0.4 mEq/hour). Gastric emptying of liquids and solids, as quantitated by the time for one half of the marker to empty (T 1/2) and the shape of the emptying curve, were similar before and after all three surgical procedures. CONCLUSIONS. Laparoscopic proximal gastric vagotomy was comparable to OPGV in decreasing stimulated gastric acid production without significantly altering gastric emptying. Anterior seromyotomy

  3. Protective Effect of Flos Lonicerae against Experimental Gastric Ulcers in Rats: Mechanisms of Antioxidant and Anti-Inflammatory Action

    PubMed Central

    Kang, Jung-Woo; Yun, Nari; Han, Hae-Jung; Kim, Jeom-Yong; Kim, Joo-Young; Lee, Sun-Mee

    2014-01-01

    Flos Lonicerae is one of the oldest and most commonly prescribed herbs in Eastern traditional medicine to treat various inflammatory diseases. In the present study, we investigated the effects of ethyl acetate fraction of Flos Lonicerae (GC-7101) on experimental gastric ulcer models and its mechanisms of action in gastric ulcer healing. The pharmacological activity of GC-7101 was investigated in rats on HCl/EtOH, indomethacin, water immersion restraint stress induced acute gastric ulcer, and acetic-acid-induced subchronic gastric ulcer. To determine its gastroprotective mechanisms, gastric wall mucus secretion, mucosal PGE2, mucosal NO content, nuclear translocation of NF-κB, mRNA expression of inflammatory cytokines, lipid peroxidation and glutathione content, and superoxide dismutase and catalase activities were measured. GC-7101 significantly attenuated development of acute gastric ulcer and accelerated the healing of acetic-acid-induced subchronic gastric ulcer. In HCl/EtOH-induced gastric ulcer, GC-7101 markedly enhanced gastric wall mucus content which was accompanied by increased mucosal PGE2 and NO production. Furthermore, treatment of GC-7101 exhibited anti-inflammatory and antioxidant activities as evidenced by decreased myeloperoxidase activity, NF-κB translocation, inflammatory cytokines mRNA expression, and lipid peroxidation and increased glutathione content and superoxide dismutase and catalase activities. These results demonstrated that GC-7101 possesses strong antiulcerogenic effect by modulating oxidative stress and proinflammatory mediators. PMID:25610477

  4. [Molecular Subtypes of Gastric Cancer].

    PubMed

    Hatogai, Ken; Doi, Toshihiko

    2016-03-01

    Gastric cancer has been classified based on the pathological characteristics including microscopic configuration and growth pattern. Although these classifications have been used in studies investigating prognosis and recurrence pattern, they are not considered for decisions regarding the therapeutic strategy. In the ToGA study, trastuzumab, an anti-HER2 monoclonal antibody, demonstrated clinical efficacy for gastric cancer with HER2 overexpression or HER2 gene amplification. Based on these findings of the ToGA study, the definition of HER2-positive gastric cancer was established. Thereafter, several molecular targeted agents, including agents targeting other receptor tyrosine kinases, have been investigated in gastric cancer. However, to date no biomarker, except HER2, has been established. Based on the recent technological development in the field of gene analysis, a comprehensive molecular evaluation of gastric cancer was performed as part of The Cancer Genome Atlas (TCGA) project, and a new molecular classification was proposed that divided gastric cancer into the following 4 subtypes: tumors positive for Epstein-Barr virus, microsatellite instability tumors, genomically stable tumors, and tumors with chromosomal instability. Each subtype has specific molecular alterations including gene mutation and amplification, DNA methylation, and protein overexpression. Additionally, some subtypes were suggested to be correlated with the clinicopathological characteristics or as targets of some molecular targeted agents that are currently under development. The new molecular classification is expected to be a roadmap for patient stratification and clinical trials on molecular targeted therapies in gastric cancer. PMID:27067842

  5. Other Helicobacters and gastric microbiota.

    PubMed

    De Witte, Chloë; Schulz, Christian; Smet, Annemieke; Malfertheiner, Peter; Haesebrouck, Freddy

    2016-09-01

    This article aimed to review the literature from 2015 dealing with gastric and enterohepatic non-Helicobacter pylori Helicobacter species (NHPH). A summary of the gastric microbiota interactions with H. pylori is also presented. An extensive number of studies were published during the last year and have led to a better understanding of the pathogenesis of infections with NHPH. These infections are increasingly reported in human patients, including infections with H. cinaedi, mainly characterized by severe bacteremia. Whole-genome sequencing appears to be the most reliable technique for identification of NHPH at species level. Presence of NHPH in laboratory animals may influence the outcome of experiments, making screening and eradication desirable. Vaccination based on UreB proteins or bacterial lysate with CCR4 antagonists as well as oral glutathione supplementation may be promising strategies to dampen the pathogenic effects associated with gastric NHPH infections. Several virulent factors such as outer membrane proteins, phospholipase C-gamma 2, Bak protein, and nickel-binding proteins are associated with colonization of the gastric mucosae and development of gastritis. The development of high-throughput sequencing has led to new insights in the gastric microbiota composition and its interaction with H. pylori. Alterations in the gastric microbiota caused by the pH-increasing effect of a H. pylori infection may increase the risk for gastric cancer. PMID:27531542

  6. Pattern-Recognition Receptors and Gastric Cancer

    PubMed Central

    Castaño-Rodríguez, Natalia; Kaakoush, Nadeem O.; Mitchell, Hazel M.

    2014-01-01

    Chronic inflammation has been associated with an increased risk of several human malignancies, a classic example being gastric adenocarcinoma (GC). Development of GC is known to result from infection of the gastric mucosa by Helicobacter pylori, which initially induces acute inflammation and, in a subset of patients, progresses over time to chronic inflammation, gastric atrophy, intestinal metaplasia, dysplasia, and finally intestinal-type GC. Germ-line encoded receptors known as pattern-recognition receptors (PRRs) are critical for generating mature pro-inflammatory cytokines that are crucial for both Th1 and Th2 responses. Given that H. pylori is initially targeted by PRRs, it is conceivable that dysfunction within genes of this arm of the immune system could modulate the host response against H. pylori infection, and subsequently influence the emergence of GC. Current evidence suggests that Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR5, and TLR9), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) (NOD1, NOD2, and NLRP3), a C-type lectin receptor (DC-SIGN), and retinoic acid-inducible gene (RIG)-I-like receptors (RIG-I and MDA-5), are involved in both the recognition of H. pylori and gastric carcinogenesis. In addition, polymorphisms in genes involved in the TLR (TLR1, TLR2, TLR4, TLR5, TLR9, and CD14) and NLR (NOD1, NOD2, NLRP3, NLRP12, NLRX1, CASP1, ASC, and CARD8) signaling pathways have been shown to modulate the risk of H. pylori infection, gastric precancerous lesions, and/or GC. Further, the modulation of PRRs has been suggested to suppress H. pylori-induced inflammation and enhance GC cell apoptosis, highlighting their potential relevance in GC therapeutics. In this review, we present current advances in our understanding of the role of the TLR and NLR signaling pathways in the pathogenesis of GC, address the involvement of other recently identified PRRs in GC, and discuss the potential implications of PRRs in GC immunotherapy

  7. Effects of the Ethyl Acetate Fraction of Alchornea triplinervia on Healing Gastric Ulcer in Rats

    PubMed Central

    Lima, Zeila P.; Bonamin, Flavia; Calvo, Tamara R.; Vilegas, Wagner; Santos, Lourdes C.; Rozza, Ariane L.; Pellizzon, Claudia H.; Rocha, Lucia R. M.; Hiruma-Lima, Clélia A.

    2011-01-01

    Alchornea triplinervia (Spreng.) Muell. Arg (Euphorbiaceae) is a medicinal plant commonly used by people living in the Cerrado region of Brazil to treat gastrointestinal ulcers. We previously described the gastroprotective action of methanolic extract (ME) of Alchornea triplinervia and the ethyl acetate fraction (EAF) in increasing of prostaglandin E2 (PGE2) gastric levels in the mucosa. In this work we evaluated the effect of EAF in promoting the healing process in rats with acetic acid-induced gastric ulcers. In addition, toxicity was investigated during treatment with EAF. After 14 days of treatment with EAF, the potent stimulator of gastric cell proliferation contributed to the acceleration of gastric ulcer healing. Upon immunohistochemical analysis, we observed a pronounced expression of COX-2, mainly in the submucosal layer. The 14-day EAF treatment also significantly increased the number of neutrophils in the gastric mucosa regeneration area. The EAF induced angiogenesis on gastric mucosa, observed as an increase of the number of blood vessels supplying the stomach in rats treated with EAF. Oral administration for 14 days of the ethyl acetate fraction from Alchornea triplinervia accelerated the healing of gastric ulcers in rats by promoting epithelial cell proliferation, increasing the number of neutrophils and stimulation of mucus production. This fraction, which contained mainly phenolic compounds, contributed to gastric mucosa healing. PMID:26791640

  8. Serum n-3 polyunsaturated fatty acids and psychological distress in early pregnancy: Adjunct Study of Japan Environment and Children's Study.

    PubMed

    Hamazaki, K; Harauma, A; Otaka, Y; Moriguchi, T; Inadera, H

    2016-01-01

    N-3 polyunsaturated fatty acids (PUFAs), especially long-chain types such as docosahexaenoic acid, are important nutrients in pregnancy, but the relationship between n-3 PUFA levels and perinatal and postnatal depression remains controversial. This study examined the possible relationship between serum n-3 PUFA levels and psychological distress among expectant mothers in early pregnancy. Data and specimen samples were obtained in a birth cohort study started at Toyama Regional Center in July 2012 as an adjunct study of the Japan Environment and Children's Study. Blood samples were collected at 9-14 weeks' gestation (75% of samples) or after 15 weeks (25%). Subjects with a Kessler Psychological Distress Scale score (K6) ⩾ 9 were assigned to the psychological distress group (n=283). The control group (n=283) was matched for age, educational level and family income. Fatty acid composition was determined from serum samples by gas chromatography. Associations between fatty acid levels and incident psychological distress were evaluated by logistic regression. After adjusting for possible confounders, eicosapentaenoic acid showed an inverse association with risk of psychological distress, with an odds ratio of 0.47 (95% confidence interval: 0.30, 0.73) for the highest tertile. This inverse association remained even after applying a higher cutoff score (K6 ⩾ 13) indicating severe psychological distress (74 pairs). We believe this is the first study to reveal the associations between serum n-3 PUFAs and risk of psychological distress in early pregnancy. Further research is required to verify the causality of these associations. PMID:26882037

  9. Biphasic dissolution method for quality control and assurance of drugs containing active substances in the form of weak acid salts.

    PubMed

    Franc, Aleš; Muselłk, Jan; Goněc, Roman; Vetchý, David

    2016-03-01

    Substances in the form of weak acid salts have been found to be problematic for dissolution testing. Their absorption can start only after they are turned into the form of an acid following the gastric passage although they were administered in the form of a salt. Due to poor solubility, they cannot be tested in acidic gastric environment for a biased dissolution profile. The biphasic dissolution method is promising for overcoming this obstacle. Tablets with warfarin clathrate sodium salt in two concentrations and two different particle size distributions were tested as a suitable model for finding the medium and process conditions of dissolution. The dissolution method based on the use of the upper organic layer (1-octanol) and the lower aqueous layer 0.1 mol L(-1) HCl) was found suitable and discriminatory for tablets containing active substances in the form of salts of weak acids. The method also reflects physical differences in the quality of used substances. PMID:26959550

  10. Exploring the physiologic role of human gastroesophageal reflux by analyzing time‐series data from 24‐h gastric and esophageal pH recordings

    PubMed Central

    Lu, Luo; Mu, John C.; Sloan, Sheldon; Miner, Philip B.; Gardner, Jerry D.

    2014-01-01

    Abstract Our previous finding of a fractal pattern for gastric pH and esophageal pH plus the statistical association of sequential pH values for up to 2 h led to our hypothesis that the fractal pattern encodes information regarding gastric acidity and that depending on the value of gastric acidity, the esophagus can signal the stomach to alter gastric acidity by influencing gastric secretion of acid or bicarbonate. Under our hypothesis values of gastric pH should provide information regarding values of esophageal pH and vice versa. We used vector autoregression, a theory‐free set of inter‐related linear regressions used to measure relationships that can change over time, to analyze data from 24‐h recordings of gastric pH and esophageal pH. We found that in pH records from normal subjects, as well as from subjects with gastroesophageal reflux disease alone and after treatment with a proton pump inhibitor, gastric pH values provided important information regarding subsequent values of esophageal pH and values of esophageal pH provided important information regarding subsequent values of gastric pH. The ability of gastric pH and esophageal pH to provide information regarding subsequent values of each other was reduced in subjects with gastroesophageal reflux disease compared to normal subjects. Our findings are consistent with the hypothesis that depending on the value of gastric acidity, the esophagus can signal the stomach to alter gastric acidity, and that this ability is impaired in subjects with gastroesophageal reflux disease. PMID:25347850

  11. Impact of a yogurt matrix and cell microencapsulation on the survival of Lactobacillus reuteri in three in vitro gastric digestion procedures.

    PubMed

    Champagne, C P; Raymond, Y; Guertin, N; Martoni, C J; Jones, M L; Mainville, I; Arcand, Y

    2015-01-01

    The goal of this study was to assess the interaction between microencapsulation and a yogurt food matrix on the survival of Lactobacillus reuteri NCIMB 30242 in four different in vitro systems that simulate a gastric environment. The four systems were: United States Pharmacopeia (USP) solutions, a static two-step (STS) procedure which included simulated food ingredients, a constantly dynamic digestion procedure (IViDiS), as well a multi-step dynamic digestion scheme (S'IViDiS). The pH profiles of the various procedures varied between systems with acidity levels being: USP > STS > IViDiS = S'IVIDiS. Addition of a food matrix increased the pH in all systems except for the USP methodology. Microencapsulation in alginate-based gels was effective in protecting the cells in model solutions when no food ingredients were present. The stability of the probiotic culture in the in vitro gastric environments was enhanced when (1) yoghurt or simulated food ingredient were present in the medium in sufficient quantity, (2) pH was higher. The procedure-comparison data of this study will be helpful in interpreting the literature with respect to viable counts of probiotics obtained from different static or dynamic in vitro gastric systems. PMID:26036146

  12. Gastric Emptying in the Elderly.

    PubMed

    Soenen, Stijn; Rayner, Chris K; Horowitz, Michael; Jones, Karen L

    2015-08-01

    Aging is characterized by a diminished homeostatic regulation of physiologic functions, including slowing of gastric emptying. Gastric and small intestinal motor and humoral mechanisms in humans are complex and highly variable: ingested food is stored, mixed with digestive enzymes, ground into small particles, and delivered as a liquefied form into the duodenum at a rate allowing efficient digestion and absorption. In healthy aging, motor function is well preserved whereas deficits in sensory function are more apparent. The effects of aging on gastric emptying are relevant to the absorption of oral medications and the regulation of appetite, postprandial glycemia, and blood pressure. PMID:26195094

  13. Fossilization potential of iron-bearing minerals in acidic environments of Rio Tinto, Spain: Implications for Mars exploration

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Knoll, Andrew H.

    2008-03-01

    Acidic waters of the Rio Tinto, southwestern Spain, evaporate seasonally, precipitating a variety of iron sulfide and oxide minerals. Schwertmannite and nanophase goethite form thin laminae on biological and detrital grain surfaces, replicating, among other things, the morphologies of insect cuticle, plant tissues, fungi, algae, and bacteria. Intergrain cements also incorporate bacterial cells and filaments. Other sulfate minerals precipitated in Rio Tinto environments are transient and contribute little to short-term preservation. Because the Rio Tinto has been cutting its current valley for several million years, terrace deposits provide a window on longer term fossil preservation. Early and later diagenesis are recorded in terrace deposits formed about one thousand and two million years ago, respectively. The sedimentary structures and mineralogies of these deposits suggest that they formed under physical and chemical conditions comparable to those of modern Rio Tinto sediments. The terrace deposits show quantitative loss of sulfate minerals, increasing crystallinity of goethite and, in the older terrace, replacement of goethite by hematite. Fossils formed originally by schwertmannite and nanophase goethite replication persist through diagenesis, preserving a long term record of local biological diversity. Fossil preservation by iron oxides in the acidic environment of Rio Tinto suggests that if life was present when sedimentary rocks formed at Meridiani Planum, Mars, precipitated minerals could record their presence.

  14. Insights from the metagenome of an acid salt lake: the role of biology in an extreme depositional environment.

    PubMed

    Johnson, Sarah Stewart; Chevrette, Marc Gerard; Ehlmann, Bethany L; Benison, Kathleen Counter

    2015-01-01

    The extremely acidic brine lakes of the Yilgarn Craton of Western Australia are home to some of the most biologically challenging waters on Earth. In this study, we employed metagenomic shotgun sequencing to generate a microbial profile of the depositional environment associated with the sulfur-rich sediments of one such lake. Of the 1.5 M high-quality reads generated, 0.25 M were mapped to protein features, which in turn provide new insights into the metabolic function of this community. In particular, 45 diverse genes associated with sulfur metabolism were identified, the majority of which were linked to either the conversion of sulfate to adenylylsulfate and the subsequent production of sulfide from sulfite or the oxidation of sulfide, elemental sulfur, and thiosulfate via the sulfur oxidation (Sox) system. This is the first metagenomic study of an acidic, hypersaline depositional environment, and we present evidence for a surprisingly high level of microbial diversity. Our findings also illuminate the possibility that we may be meaningfully underestimating the effects of biology on the chemistry of these sulfur-rich sediments, thereby influencing our understanding of past geobiological conditions that may have been present on Earth as well as early Mars. PMID:25923206

  15. Insights from the Metagenome of an Acid Salt Lake: The Role of Biology in an Extreme Depositional Environment

    PubMed Central

    Johnson, Sarah Stewart; Chevrette, Marc Gerard; Ehlmann, Bethany L.; Benison, Kathleen Counter

    2015-01-01

    The extremely acidic brine lakes of the Yilgarn Craton of Western Australia are home to some of the most biologically challenging waters on Earth. In this study, we employed metagenomic shotgun sequencing to generate a microbial profile of the depositional environment associated with the sulfur-rich sediments of one such lake. Of the 1.5 M high-quality reads generated, 0.25 M were mapped to protein features, which in turn provide new insights into the metabolic function of this community. In particular, 45 diverse genes associated with sulfur metabolism were identified, the majority of which were linked to either the conversion of sulfate to adenylylsulfate and the subsequent production of sulfide from sulfite or the oxidation of sulfide, elemental sulfur, and thiosulfate via the sulfur oxidation (Sox) system. This is the first metagenomic study of an acidic, hypersaline depositional environment, and we present evidence for a surprisingly high level of microbial diversity. Our findings also illuminate the possibility that we may be meaningfully underestimating the effects of biology on the chemistry of these sulfur-rich sediments, thereby influencing our understanding of past geobiological conditions that may have been present on Earth as well as early Mars. PMID:25923206

  16. Detection of Thiobacillus ferrooxidans in acid mine environments by indirect fluorescent antibody staining.

    PubMed

    Apel, W A; Dugan, P R; Filppi, J A; Rheins, M S

    1976-07-01

    An indirect fluorescent antibody (FA) staining technique was developed for the rapid detection of Thiobacillus ferrooxidans. The specificity of the FA stain for T. ferrooxidans was demonstrated with both laboratory and environmental samples. Coal refuse examined by scanning electron microscopy exhibited a rough, porous surface, which was characteristically covered by water-soluble crystals. Significant numbers of T. ferrooxidans were detected in the refuse pores. A positive correlation between numbers of T. ferrooxidans and acid production in coal refuse in the laboratory was demonstrated with the FA technique. PMID:61736

  17. Protective effect of palm vitamin E and α-tocopherol against gastric lesions induced by water immersion restraint stress in Sprague-Dawley rats

    PubMed Central

    Ibrahim, Ibrahim Abdel Aziz; Yusof, Kamisah; Ismail, Nafeeza Mohd; Fahami, Nur Azlina Mohd

    2008-01-01

    Objective: Stress can lead to various changes in the gastrointestinal tract of rats. The present study was designed to compare the effect of palm vitamin E (PVE) and α-tocopherol (α-TF) supplementations on the gastric parameters important in maintaining gastric mucosal integrity in rats exposed to water immersion restraint stress (WRS). These parameters include gastric acidity, plasma gastrin level, gastric prostaglandin E2 (PGE2), and gastric lesions. Materials and Methods: Sixty male Sprague-Dawley rats (200-250 g) were divided into three equal groups: a control group, which received a normal rat diet (RC), and two treatment groups, receiving oral supplementation of either PVE or α-TF at 60 mg/kg body weight for 28 days. Each group was further divided into two groups: the nonstress and stress groups. The stress groups were subjected to 3.5 h of WRS once at the end of the treatment period. Blood samples were then taken to measure the gastrin level, after which the rats were killed. Gastric juice was collected for measurement of gastric acidity and gastric tissue was taken for measurement of gastric mucosal lesions and PGE2. Results: Exposure to stress resulted in the production of gastric lesions. PVE and α-TF lowered the lesion indices as compared to the stress control group. Stress reduced gastric acidity but pretreatment with PVE and α-TF prevented this reduction. The gastrin levels in the stress group were lower as compared to that in the nonstress control. However, following treatment with PVE and α-TF, gastrin levels increased and approached the normal level. There was also a significant reduction in the gastric PGE2 content with stress exposure, but this reduction was blocked with treatment with both PVE and α-TF. Conclusion: In conclusion, WRS leads to a reduction in the gastric acidity, gastrin level, and gastric PGE2 level and there is increased formation of gastric lesions. Supplementation with either PVE or α-TF reduces the formation of gastric

  18. TolC is important for bacterial survival and oxidative stress response in Salmonella enterica serovar Choleraesuis in an acidic environment.

    PubMed

    Lee, Jen-Jie; Wu, Ying-Chen; Kuo, Chih-Jung; Hsuan, Shih-Ling; Chen, Ter-Hsin

    2016-09-25

    The outer membrane protein TolC, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in Enterobacteriaceae. Since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether TolC played a role in the acid tolerance of Salmonella enterica serovar Choleraesuis. Comparison of the acid tolerance of the tolC mutant and the parental wild-type strain showed that the absence of TolC limits the ability of Salmonella to sustain life under extreme acidic conditions. Additionally, the mutant exhibited morphological changes during growth in an acidic medium, leading to the conflicting results of cell viability measured by spectrophotometry and colony-forming unit counting. Reverse-transcriptional-PCR analysis indicated that acid-related molecules, apparatus, or enzymes and oxidation-induced factors were significantly affected by the acidic environment in the null-tolC mutant. The elongated cellular morphology was restored by adding antioxidants to the culture medium. Furthermore, we found that increased cellular antioxidative activity provides an overlapping protection against acid killing, demonstrating the complexity of the bacterial acid stress response. Our findings reinforce the multifunctional characteristics of TolC in acid tolerance or oxidative stress resistance and support the correlative protection mechanism between oxygen- and acid-mediated stress responses in Salmonella enterica serovar Choleraesuis. PMID:27599929

  19. Gastroprotective effect of a traditional Chinese herbal drug "Baishouwu" on experimental gastric lesions in rats.

    PubMed

    Shan, Lei; Liu, Run-Hui; Shen, Yun-Heng; Zhang, Wei-Dong; Zhang, Chuan; Wu, Da-Zheng; Min, Li; Su, Juan; Xu, Xi-Ke

    2006-10-11

    "Baishouwu" is an appellative name of dried root tubers from three Asclepiadaceae plants: Cynanchum auriculatum Royle ex Wight, Cynanchum bungei Decne and Cynoctonum wilfordii Maxim. In order to establish the pharmacological basis for the ethnomedicinal use of Baishouwu in gastric disorders, this study examined the effects of ethanol extracts and fractions from root tubers of Cynanchum auriculatum, Cynanchum bungei and Cynoctonum wilfordii on ethanol-, indomethacin-induced gastric lesions and histamine-induced gastric acid secretion in rats. Plant materials were collected from various areas of China. Oral administration of ethanol extract and chloroform fraction of Cynoctonum wilfordii collected from Changbai Cordillera at doses of 150 and 68 mg/kg, respectively, significantly inhibited the development of ethanol- and indomethacin-induced gastric lesions and also caused significant decrease of gastric acid secretion after histamine-induced gastric lesion. Oral administrations of ethanol extract and chloroform fraction of Cynanchum auriculatum collected from Binhai at the doses of 300 and 69 mg/kg, respectively, significantly inhibited ethanol- and indomethacin-induced gastric lesions. This study demonstrates the gastroprotective property of Baishouwu for the first time. PMID:16678989

  20. Protective effect of ketoconazole against experimentally induced gastric ulcers in rats.

    PubMed

    Al Moutaery, Ahmed R

    2003-01-01

    Recent studies suggest the critical role of inflammatory mediators in the genesis and healing of gastric ulcers. Ketoconazole a commonly used anti-fungal agent has a potent immunomodulatory action. The present investigation was undertaken to study the effect of ketoconazole on chemically and stress induced gastric ulcers in rats. Experimental gastric lesions in rats were induced by water immersion restraint stress, indomethacin and ethanol. Acid secretion studies were undertaken in pylorus ligated rats with and without ketoconazole. The level of myeloperoxidase (marker of neutrophil activity) non-protein sulfhydryl compounds and gastric wall mucus were measured after ethanol induced gastric lesions. Ketoconazole treatment resulted in significant protection against stress; indomethacin and ethanol induced gastric lesions in rats. Ketoconazole also dose dependently attenuated ethanol induced increase in myeloperoxidase activity and protected gastric mucosa against ethanol-induced depletion of non-protein sulfhydryl. These findings point towards the mediation of neutrophils and sulfhydryl compounds in ketoconazole induced cytoprotection. In conclusion, this study clearly shows anti-acid secretory, anti-ulcer and cytoprotective activity of ketoconazole. PMID:15686104

  1. Acid, protons and Helicobacter pylori.

    PubMed Central

    Sachs, G.; Meyer-Rosberg, K.; Scott, D. R.; Melchers, K.

    1996-01-01

    The anti-ulcer drugs that act as covalent inhibitors of the gastric acid pump are targeted to the gastric H+/K+ ATPase by virtue of accumulation in acid and conversion to the active sulfenamide. This results in extremely effective inhibition of acid secretion. Appropriate dosage is able to optimize acid control therapy for reflux and peptic ulcer disease as compared to H2 receptor antagonists. However, clinical data on recurrence show that Helicobacter pylori eradication should accompany treatment of the lesion. These drugs have been found to synergize with many antibiotics for eradication. The survival of aerobes depends on their ability to maintain a driving force for protons across their inner membrane, the sum of a pH and potential difference gradient, the protonmotive force (pmf). The transmembrane flux of protons across the F1F0 ATPase, driven by the pmf, is coupled to the synthesis of ATP. The internal pH of H. pylori was measured using the fluorescent dye probe, BCECF, and the membrane potential defined by the uptake of the carbocyanine dye, DiSC3 [5] at different pHs to mimic the gastric environment. The protonmotive force at pH 7.0 was composed of a delta pH of 1.4 (-84mV) and a delta potential difference of -131mV, to give a pmf of -215 mV. The effect of variations in external pH on survival of the bacteria in the absence of urea correlated with the effect of external pH on the ability of the bacteria to maintain a pmf. The effect of the addition of 5 mM urea on the pmf was measured at different medium pH values. Urea restored the pmf at pH 3.0 or 3.5, but abolished the pmf at pH 7.0 or higher, due the production of the alkalinizing cation, NH3. Hence H. pylori is an acid-tolerant neutrophile due to urease activity, but urease activity also limits its survival to an acidic environment. These data help explain the occupation of the stomach by the organism and its distribution between fundus and antrum. This distribution and its alteration by proton pump

  2. Human gastric cancer, Helicobacter pylori and bracken carcinogens: A connecting hypothesis.

    PubMed

    Oliveros-Bastidas, Alberto; Calcagno-Pissarelli, María Pía; Naya, Marlene; Ávila-Núñez, Jorge Luis; Alonso-Amelot, Miguel E

    2016-03-01

    Long term infection of Helicobacter pylori (Hp) virulent strains is a key factor in the genesis of human gastric cancer, and so are certain dietary proinflammatory and genotoxic compounds. Carcinogenic bracken fern (Pteridium spp.) is one of these. Toxins from this plant are consumed as bracken culinary preparations, through milk and meat of bracken-exposed livestock, and drain waters from bracken swards. Bracken toxin ptaquiloside (PtQ), a suspected human carcinogen, elicits complex responses in animals leading to death. PtQ and Hp might cooperate in gastric pathologies. This paper presents an hypothesis on PtQ-Hp association leading to the enhancement of carcinogenesis in the human gastric environment that might explain the high gastric cancer incidence and death rates among Hp-infected people living in bracken zones at two levels: (1) The macroscopic scale comprising the flow of PtQ in the human diet. (2) the microscopic scale encompassing (A) gastric luminal medium; (B) gastric mucus structure and mucin degradation elicited by Hp; (C) bacterial pH gradient modification of the gastric mucosa that favors PtQ survival and its penetration into epithelial tissue; (D) combined PtQ/Hp effects on gastric immune and inflammatory responses; (E) PtQ-Hp complementary activity at selected cell signaling cascades and genome disturbance. PMID:26632203

  3. Remodeling of the Vibrio cholerae membrane by incorporation of exogenous fatty acids from host and aquatic environments

    PubMed Central

    Giles, David K.; Hankins, Jessica V.; Guan, Ziqiang; Trent, M. Stephen

    2011-01-01

    Summary The Gram-negative bacteria Vibrio cholerae poses significant public health concerns by causing an acute intestinal infection afflicting millions of people each year. V. cholerae motility, as well as virulence factor expression and outer membrane protein production, have been shown to be affected by bile (Childers & Klose, 2007). The current study examines the effects of bile on V. cholerae phospholipids. Bile exposure caused significant alterations to the phospholipid profile of V. cholerae but not of other enteric pathogens. These changes consisted of a quantitative increase and migratory difference in cardiolipin, decreases in phosphatidylglycerol and phosphatidylethanolamine, and the dramatic appearance of an unknown phospholipid determined to be lyso-phosphatidylethanolamine. Major components of bile were not responsible for the observed changes, but long chain polyunsaturated fatty acids, which are minor components of bile, were shown to be incorporated into phospholipids of V. cholerae. Although the bile-induced phospholipid profile was independent of the V. cholerae virulence cascade, we identified another relevant environment in which V. cholerae assimilates unique fatty acids into its membrane phospholipids—marine sediment. Our results suggest that Vibrio species possess unique machinery conferring the ability to take up a wider range of exogenous fatty acids than other enteric bacteria. PMID:21255114

  4. Life in protein-rich environments: the relA-independent response of Streptococcus pyogenes to amino acid starvation.

    PubMed

    Steiner, K; Malke, H

    2000-12-01

    Considering that group A streptococci are multiple auxotrophs that may encounter shortage of amino acids during specific stages of the infectious process, we studied their adaptive response to amino acid deprivation. We found that, in addition to the (p)ppGpp-mediated stringent response characterized previously, Streptococcus pyogenes exhibits a relA-independent response comprising transcriptional modulation of a specific subset of genes involved in pathogenesis. Genes/operons transcriptionally upregulated during starvation of both wild type and relA mutants included the two-component signal transduction system covRS, the positive regulator (ropB) of the pyrogenic exotoxin B gene, speB, the oligopeptide (opp) and dipeptide (dpp) permease systems and the pepB gene putatively involved in the intracellular processing of oligopeptides. Upregulation of covRS was accompanied by downregulation of ska, one of the target genes of the negative CovR regulator, and the net effect of amino acid starvation also favoured repression of speB. A significant feature of upregulated opp expression was stimulated readthrough transcription of the operon-internal oppA terminator, leading to increased mRNA levels for synthesis of the translocator complex relative to the substrate-binding protein. Based on these and previous results, a stimulus-response network is proposed that counteracts the stringent response and may enable the pathogen to mount a dynamic response to the protein-rich environment provided by its human host. PMID:11123674

  5. pH-Sensitive Polymeric Micelle-based pH Probe for Detecting and Imaging Acidic Biological Environments

    PubMed Central

    Lee, Young Ju; Kang, Han Chang; Hu, Jun; Nichols, Joseph W.; Jeon, Yong Sun; Bae, You Han

    2012-01-01

    To overcome the limitations of monomeric pH probes for acidic tumor environments, this study designed a mixed micelle pH probe composed of polyethylene glycol (PEG)-b- poly(L-histidine) (PHis) and PEG-b-poly(L-lactic acid) (PLLA), which is well-known as an effective antitumor drug carrier. Unlike monomeric histidine and PHis derivatives, the mixed micelles can be structurally destabilized by changes in pH, leading to a better pH sensing system in nuclear magnetic resonance (NMR) techniques. The acidic pH-induced transformation of the mixed micelles allowed pH detection and pH mapping of 0.2–0.3 pH unit differences by pH-induced “on/off”-like sensing of NMR and magnetic resonance spectroscopy (MRS). The micellar pH probes sensed pH differences in non-biological phosphate buffer and biological buffers such as cell culture medium and rat whole blood. In addition, the pH-sensing ability of the mixed micelles was not compromised by loaded doxorubicin. In conclusion, PHis-based micelles could have potential as a tool to simultaneously treat and map the pH of solid tumors in vivo. PMID:22861824

  6. What gastric cancer proteomic studies show about gastric carcinogenesis?

    PubMed

    Leal, Mariana Ferreira; Wisnieski, Fernanda; de Oliveira Gigek, Carolina; do Santos, Leonardo Caires; Calcagno, Danielle Queiroz; Burbano, Rommel Rodriguez; Smith, Marilia Cardoso

    2016-08-01

    Gastric cancer is a complex, heterogeneous, and multistep disease. Over the past decades, several studies have aimed to determine the molecular factors that lead to gastric cancer development and progression. After completing the human genome sequencing, proteomic technologies have presented rapid progress. Differently from the relative static state of genome, the cell proteome is dynamic and changes in pathologic conditions. Proteomic approaches have been used to determine proteome profiles and identify differentially expressed proteins between groups of samples, such as neoplastic and nonneoplastic samples or between samples of different cancer subtypes or stages. Therefore, proteomic technologies are a useful tool toward improving the knowledge of gastric cancer molecular pathogenesis and the understanding of tumor heterogeneity. This review aimed to summarize the proteins or protein families that are frequently identified by using high-throughput screening methods and which thus may have a key role in gastric carcinogenesis. The increased knowledge of gastric carcinogenesis will clearly help in the development of new anticancer treatments. Although the studies are still in their infancy, the reviewed proteins may be useful for gastric cancer diagnosis, prognosis, and patient management. PMID:27126070

  7. Protective effect of coadministered superoxide dismutase and catalase against stress-induced gastric mucosal lesions.

    PubMed

    Ohta, Yoshiji; Nishida, Keiji

    2003-08-01

    1. There are conflicting reports as to the protective effect of coadministered native superoxide dismutase (SOD) and catalase against gastric mucosal lesions in rats with water immersion restraint (WIR) stress. It is unclear how coadministered native SOD and catalase protect against WIR stress-induced gastric mucosal lesions. Therefore, in the present study, we re-examined the protective effect of coadministered native SOD and catalase against gastric mucosal lesions in rats with WIR stress. 2. Gastric mucosal lesions were induced in Wistar rats by 3 h WIR. Rats were injected subcutaneously with a mixture of purified bovine erythrocyte SOD and bovine liver catalase 1 h before the onset of WIR. Ulcer index, serum SOD, catalase and xanthine oxidase (XO), uric acid and gastric mucosal SOD, catalase, XO, myeloperoxidase (MPO; an index of tissue neutrophil infiltration), non-protein sulfhydryl (NP-SH) and thiobarbituric acid-reactive substances (TBARS; an index of lipid peroxidation) were assayed in all rats used. 3. Rats with 3 h WIR showed gastric mucosal lesions. Pre-administration of SOD plus catalase to rats with WIR prevented lesion formation. In the serum of rats with WIR alone, XO activity and uric acid concentration increased, whereas SOD and catalase activities did not change. Pre-administration of SOD plus catalase to rats with WIR did not affect increased serum XO activity and uric acid concentration, but did increase serum SOD and catalase activities. In the gastric mucosa of rats with WIR alone, increases in MPO activity and TBARS concentration and a decrease in NP-SH concentration occurred, whereas XO, SOD and catalase activities did not change. Pre-administration of SOD plus catalase to rats with WIR attenuated the changes in gastric mucosal MPO activity and TBARS and NP-SH concentrations, but did not affect gastric mucosal XO, SOD and catalase activities. Pre-administration of SOD plus catalase (in an inactivated form) to rats with WIR had no effect on

  8. Expression of urease by Haemophilus influenzae during human respiratory tract infection and role in survival in an acid environment

    PubMed Central

    2011-01-01

    Background Nontypeable Haemophilus influenzae is a common cause of otitis media in children and lower respiratory tract infection in adults with chronic obstructive pulmonary disease (COPD). Prior studies have shown that H. influenzae expresses abundant urease during growth in the middle ear of the chinchilla and in pooled human sputum, suggesting that expression of urease is important for colonization and infection in the hostile environments of the middle ear and in the airways in adults. Virtually nothing else is known about the urease of H. influenzae, which was characterized in the present study. Results Analysis by reverse transcriptase PCR revealed that the ure gene cluster is expressed as a single transcript. Knockout mutants of a urease structural gene (ureC) and of the entire ure operon demonstrated no detectable urease activity indicating that this operon is the only one encoding an active urease. The ure operon is present in all strains tested, including clinical isolates from otitis media and COPD. Urease activity decreased as nitrogen availability increased. To test the hypothesis that urease is expressed during human infection, purified recombinant urease C was used in ELISA with pre acquisition and post infection serum from adults with COPD who experienced infections caused by H. influenzae. A total of 28% of patients developed new antibodies following infection indicating that H. influenzae expresses urease during airway infection. Bacterial viability assays performed at varying pH indicate that urease mediates survival of H. influenzae in an acid environment. Conclusions The H. influenzae genome contains a single urease operon that mediates urease expression and that is present in all clinical isolates tested. Nitrogen availability is a determinant of urease expression. H. influenzae expresses urease during human respiratory tract infection and urease is a target of the human antibody response. Expression of urease enhances viability in an acid

  9. Human gastric juice contains chitinase that can degrade chitin.

    PubMed

    Paoletti, Maurizio G; Norberto, Lorenzo; Damini, Roberta; Musumeci, Salvatore

    2007-01-01

    Chitin digestion by humans has generally been questioned or denied. Only recently chitinases have been found in several human tissues and their role has been associated with defense against parasite infections and to some allergic conditions. In this pilot study we tested the gastric juices of 25 Italian subjects on the artificial substrates 4-methylumbelliferyl-beta-D-N,N',diacetylchitobiose or/and fluorescein isothiocyanate (FITC) chitin to demonstrate the presence of a chitinase activity. Since this chitinase activity was demonstrated at acidic pH, it is currently referred to acidic mammalian chitinase (AMCase). AMCase activity was present in gastric juices of twenty of 25 Italian patients in a range of activity from 0.21 to 36.27 nmol/ml/h and from 8,881 to 1,254,782 fluorescence emission (CPS), according to the used methods. In the remaining five of 25 gastric juices, AMCase activity was almost absent in both assay methods. An allosamidine inhibition test and the measurement at different pH values confirmed that this activity was characteristic of AMCase. The absence of activity in 20% of the gastric juices may be a consequence of virtual absence of chitinous food in the Western diet. PMID:17587796

  10. ERRgamma regulates cardiac, gastric, and renal potassium homeostasis.

    PubMed

    Alaynick, William A; Way, James M; Wilson, Stephanie A; Benson, William G; Pei, Liming; Downes, Michael; Yu, Ruth; Jonker, Johan W; Holt, Jason A; Rajpal, Deepak K; Li, Hao; Stuart, Joan; McPherson, Ruth; Remlinger, Katja S; Chang, Ching-Yi; McDonnell, Donald P; Evans, Ronald M; Billin, Andrew N

    2010-02-01

    Energy production by oxidative metabolism in kidney, stomach, and heart, is primarily expended in establishing ion gradients to drive renal electrolyte homeostasis, gastric acid secretion, and cardiac muscle contraction, respectively. In addition to orchestrating transcriptional control of oxidative metabolism, the orphan nuclear receptor, estrogen-related receptor gamma (ERRgamma), coordinates expression of genes central to ion homeostasis in oxidative tissues. Renal, gastric, and cardiac tissues subjected to genomic analysis of expression in perinatal ERRgamma null mice revealed a characteristic dysregulation of genes involved in transport processes, exemplified by the voltage-gated potassium channel, Kcne2. Consistently, ERRgamma null animals die during the first 72 h of life with elevated serum potassium, reductions in key gastric acid production markers, and cardiac arrhythmia with prolonged QT intervals. In addition, we find altered expression of several genes associated with hypertension in ERRgamma null mice. These findings suggest a potential role for genetic polymorphisms at the ERRgamma locus and ERRgamma modulators in the etiology and treatment of renal, gastric, and cardiac dysfunction. PMID:19965931

  11. ERRγ Regulates Cardiac, Gastric, and Renal Potassium Homeostasis

    PubMed Central

    Alaynick, William A.; Way, James M.; Wilson, Stephanie A.; Benson, William G.; Pei, Liming; Downes, Michael; Yu, Ruth; Jonker, Johan W.; Holt, Jason A.; Rajpal, Deepak K.; Li, Hao; Stuart, Joan; McPherson, Ruth; Remlinger, Katja S.; Chang, Ching-Yi; McDonnell, Donald P.; Evans, Ronald M.; Billin, Andrew N.

    2010-01-01

    Energy production by oxidative metabolism in kidney, stomach, and heart, is primarily expended in establishing ion gradients to drive renal electrolyte homeostasis, gastric acid secretion, and cardiac muscle contraction, respectively. In addition to orchestrating transcriptional control of oxidative metabolism, the orphan nuclear receptor, estrogen-related receptor γ (ERRγ), coordinates expression of genes central to ion homeostasis in oxidative tissues. Renal, gastric, and cardiac tissues subjected to genomic analysis of expression in perinatal ERRγ null mice revealed a characteristic dysregulation of genes involved in transport processes, exemplified by the voltage-gated potassium channel, Kcne2. Consistently, ERRγ null animals die during the first 72 h of life with elevated serum potassium, reductions in key gastric acid production markers, and cardiac arrhythmia with prolonged QT intervals. In addition, we find altered expression of several genes associated with hypertension in ERRγ null mice. These findings suggest a potential role for genetic polymorphisms at the ERRγ locus and ERRγ modulators in the etiology and treatment of renal, gastric, and cardiac dysfunction. PMID:19965931

  12. Development of a Supported Emulsion Liquid Membrane System for Propionic Acid Separation in a Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Li, Jin; Hu, Shih-Yao B.; Wiencek, John M.

    2001-01-01

    Perstractive fermentation is a good way to increase the productivity of bioreactors. Using Propionibacteria as the model system, the feasibility of using supported emulsion liquid membrane (SELM) for perstractive fermentation is assessed in this study. Five industrial solvents were considered as the solvent for preparing the SELM. The more polar a solvent is, the higher the partition coefficient. However, toxicity of a solvent also increases with its polarity. CO-1055 (industrial decanol/octanol blend) has the highest partition coefficient toward propionic acid among the solvents that has no molecular toxicity toward Propionibacteria. A preliminary extraction study was conducted using tetradecane as solvent in a hydrophobic hollow fiber contactor. The result confirmed that SELM eliminates the equilibrium limitation of conventional liquid-liquid extraction, and allows the use of a non-toxic solvent with low partition coefficient.

  13. Evidence that Resorption of Bone by Rat Peritoneal Macrophages Occurs in an Acidic Environment

    NASA Technical Reports Server (NTRS)

    Blair, H. C.

    1985-01-01

    Skeletal loss in space, like any form of osteoporosis, reflects a relative imbalance of the activities of cells resorbing (degrading) or forming bone. Consequently, prevention of weightlessness induced bone loss may theoretically be accomplished by (1) stimulating bone formation or (2) inhibiting bone resorption. This approach, however, requires fundamental understanding of the mechanisms by which cells form or degrade bone, information not yet at hand. An issue central to bone resorption is the pH at which resorption takes place. The pH dependent spectral shift of a fluorescent dye (fluorescein isothiocyanate) conjugated to bone matrix was used to determine the pH at the resorptive cell bone matrix interface. Devitalized rat bone was used as the substrate, and rat peritoneal macrophages were used as the bone resorbing cells. The results suggest that bone resorption is the result of generation of an acidic microenvironment at the cell matrix junction.

  14. Ability of crassulacean acid metabolism plants to overcome interacting stresses in tropical environments

    PubMed Central

    Lüttge, Ulrich

    2010-01-01

    Background and aims Single stressors such as scarcity of water and extreme temperatures dominate the struggle for life in severely dry desert ecosystems or cold polar regions and at high elevations. In contrast, stress in the tropics typically arises from a dynamic network of interacting stressors, such as availability of water, CO2, light and nutrients, temperature and salinity. This requires more plastic spatio-temporal responsiveness and versatility in the acquisition and defence of ecological niches. Crassulacean acid metabolism The mode of photosynthesis of crassulacean acid metabolism (CAM) is described and its flexible expression endows plants with powerful strategies for both acclimation and adaptation. Thus, CAM plants are able to inhabit many diverse habitats in the tropics and are not, as commonly thought, successful predominantly in dry, high-insolation habitats. Tropical CAM habitats Typical tropical CAM habitats or ecosystems include exposed lava fields, rock outcrops of inselbergs, salinas, savannas, restingas, high-altitude páramos, dry forests and moist forests. Morphotypical and physiotypical plasticity of CAM Morphotypical and physiotypical plasticity of CAM phenotypes allow a wide ecophysiological amplitude of niche occupation in the tropics. Physiological and biochemical plasticity appear more responsive by having more readily reversible variations in performance than do morphological adaptations. This makes CAM plants particularly fit for the multi-factor stressor networks of tropical forests. Thus, while the physiognomy of semi-deserts outside the tropics is often determined by tall succulent CAM plants, tropical forests house many more CAM plants in terms of quantity (biomass) and quality (species diversity). PMID:22476063

  15. Importance of luminal and mucosal zinc in the mechanism of experimental gastric ulcer healing.

    PubMed

    Opoka, W; Adamek, D; Plonka, M; Reczynski, W; Bas, B; Drozdowicz, D; Jagielski, P; Sliwowski, Z; Adamski, P; Brzozowski, T

    2010-10-01

    Zinc has been reported to exert a gastroprotective action against various experimental gastric lesions suggesting that this trace element is involved in the integrity of the gastric mucosa. Compounds containing zinc, such as polaprezinc, were developed in Japan and used as an antiulcer drugs in the treatment of human peptic ulcer disease. However, the precise mechanism of Zn(2+) containing compounds and their effects on mucosal integrity, gastroprotection and ulcer healing remain unclear. We have determined the efficacy of zinc hydroaspartate, a compound containing Zn(2+), in the mechanism of gastric secretion and ulcer healing in rats with chronic gastric ulcers induced by acetic acid (initial ulcer area = 28 mm(2)). Rats with gastric ulcers were randomized into two groups: A) with gastric fistulas (GF) and B) without gastric fistulas and received a daily treatment with zinc hydroaspartate (32-130 mg/kg-d i.g.) for 3, 7 and 14 days. At the termination of each treatment, the area of gastric ulcers were examined by planimetry, the gastric blood flow (GBF) at ulcer margin was assessed by laser Doppler flowmetry and H(2)-gas clearance methods. The venous blood was withdrawn for a measurement of plasma gastrin levels by radioimmunoassay (RIA). The concentration of Zn(2+) in the gastric juice and mucosa at the ulcer margin were determined by differential pulse anodic stripping voltammetry (DPASV) and flame atomic absorption spectrometry (FAAS) methods and the gastric biopsy samples were taken for histopathological assessment of the quality of ulcer healing. The ulcers healed gradually, with the ulcer area in the vehicle control rats being diminished by 15%, 48% and 78% upon ulcer induction at 3, 7 and 14 days, respectively. Zinc hydroaspartate dose-dependently inhibited the area of gastric ulcer, the dose reducing this area by 50% (ID(50)) being about 60 mg/kg-d. The mucosal concentration of Zn(2+) significantly was unchanged from the baseline immediately after ulcer

  16. Adaptive Evolution of Eel Fluorescent Proteins from Fatty Acid Binding Proteins Produces Bright Fluorescence in the Marine Environment

    PubMed Central

    Gruber, David F.; Gaffney, Jean P.; Mehr, Shaadi; DeSalle, Rob; Sparks, John S.; Platisa, Jelena; Pieribone, Vincent A.

    2015-01-01

    We report the identification and characterization of two new members of a family of bilirubin-inducible fluorescent proteins (FPs) from marine chlopsid eels and demonstrate a key region of the sequence that serves as an evolutionary switch from non-fluorescent to fluorescent fatty acid-binding proteins (FABPs). Using transcriptomic analysis of two species of brightly fluorescent Kaupichthys eels (Kaupichthys hyoproroides and Kaupichthys n. sp.), two new FPs were identified, cloned and characterized (Chlopsid FP I and Chlopsid FP II). We then performed phylogenetic analysis on 210 FABPs, spanning 16 vertebrate orders, and including 163 vertebrate taxa. We show that the fluorescent FPs diverged as a protein family and are the sister group to brain FABPs. Our results indicate that the evolution of this family involved at least three gene duplication events. We show that fluorescent FABPs possess a unique, conserved tripeptide Gly-Pro-Pro sequence motif, which is not found in non-fluorescent fatty acid binding proteins. This motif arose from a duplication event of the FABP brain isoforms and was under strong purifying selection, leading to the classification of this new FP family. Residues adjacent to the motif are under strong positive selection, suggesting a further refinement of the eel protein’s fluorescent properties. We present a phylogenetic reconstruction of this emerging FP family and describe additional fluorescent FABP members from groups of distantly related eels. The elucidation of this class of fish FPs with diverse properties provides new templates for the development of protein-based fluorescent tools. The evolutionary adaptation from fatty acid-binding proteins to fluorescent fatty acid-binding proteins raises intrigue as to the functional role of bright green fluorescence in this cryptic genus of reclusive eels that inhabit a blue, nearly monochromatic, marine environment. PMID:26561348

  17. Gastric cancer pathogenesis.

    PubMed

    Berger, Hilmar; Marques, Miguel S; Zietlow, Rike; Meyer, Thomas F; Machado, Jose C; Figueiredo, Ceu

    2016-09-01

    Gastric cancer (GC) results from a multistep process that is influenced by Helicobacter pylori infection, genetic susceptibility of the host, as well as of other environmental factors. GC results from the accumulation of numerous genetic and epigenetic alterations in oncogenes and tumor suppressor genes, leading to dysregulation of multiple signaling pathways, which disrupt the cell cycle and the balance between cell proliferation and cell death. For this special issue, we have selected to review last year's advances related to three main topics: the cell of origin that initiates malignant growth in GC, the mechanisms of direct genotoxicity induced by H. pylori infection, and the role of aberrantly expressed long noncoding RNAs in GC transformation. The understanding of the molecular basis of GC development is of utmost importance for the identification of novel targets for GC prevention and treatment. PMID:27531537

  18. [Gastric duplication of 3 observations].

    PubMed

    Bugallo, M; Carauni, D; Serra, E; De los Reyes, C; Briend, S; Valdovinos, B; Lanari, A

    2000-01-01

    Gástric duplicación si an infrequent congenital malformation present in both, neonatal period and childhood, and exceptionally during adulthood. We present here there cases of gastric duplication from patients of different ages, in which it was not possible to make diagnosis before surgery. In all of them cystic form was the predominating one, without communication with gastric lumen (cavity). Diagnosis was performed after laparotomy and histopathological examination. PMID:11086515

  19. Effect of lapachol, a naphthaquinone isolated from Tectona grandis, on experimental peptic ulcer and gastric secretion.

    PubMed

    Goel, R K; Pathak, N K; Biswas, M; Pandey, V B; Sanyal, A K

    1987-02-01

    Lapachol, a naphthaquinone isolated from the roots of Tectona grandis given at a dose of 5 mg kg-1 p.o. twice daily for 3 days was found to have an anti-ulcerogenic effect on subsequently induced experimental gastric and duodenal ulcers in rats and guinea-pigs. Its action appears to be associated with an effect on the protein content of gastric juice, and it reversed aspirin-induced changes in peptic activity, protein and sialic acid. PMID:2882001

  20. Gastric mucous neck cell and intestinal goblet cell phenotypes in gastric adenocarcinoma.

    PubMed Central

    Hughes, N R; Bhathal, P S

    1997-01-01

    AIM: To investigate the phenotype of cells comprising diffuse and intestinal-type gastric cancers using monoclonal antibodies to two antigens. One antigen (designated D10) is characteristic of gastric mucous neck cells, cardiac glands, pyloric glands, and Brunner's glands. The second antigen (designated 17NM) is specific to the mucous vacuole of intestinal goblet cells. METHODS: Thirty two gastrectomy specimens with adenocarcinoma were studied. Serial paraffin sections were stained immunohistochemically for D10 and 17NM and histochemically for acid and neutral mucins. The cancers were classified histologically as of either diffuse or intestinal type according to Lauren. RESULTS: Of 15 diffuse-type gastric carcinomas, 11 showed the majority of cancer cells staining for D10 while four were typical signet ring cell cancers staining predominantly for 17NM; five tumours displayed both phenotypes with the two phenotypes segregated in different areas of the tumours. In contrast, of 16 intestinal-type cancers, six expressed 17NM, three D10, five neither antigen, and two expressed both antigens. One indeterminate-type cancer expressed both antigens. The staining of individual cells for D10 and 17NM was mutually exclusive in both diffuse and intestinal types. In contrast to the diffuse cancers, intestinal-type cancers typically expressed either antigen only in occasional small groups of cells and individual cells. CONCLUSIONS: In disease, the gastric stem cell can assume the capacity of the duodenal stem cell for divergent differentiation into either intestinal goblet cells (for example, as in intestinal metaplasia) or Brunner's gland cells (for example, as in pyloric gland/Brunner's gland metaplasia). With neoplastic transformation, this potential for divergent differentiation is maintained and gives rise to diffuse-type cancers that display either the D10 phenotype, the 17NM phenotype, or the clonal expression of both phenotypes. In the more cell cohesive (intestinal

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