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Does Helicobacter pylori infection affect gastric emptying in patients with functional dyspepsia?
A102
AGA ABSTRACTS
• EXTENSIVE DIVERSITY IN METABOLIC-ENZYME PROFILES IN HEIJCOBACTER PYI.,ORL M.F. Go. V. Kaput, D.Y. Graham, J.MMusser. Depts. of Medicine and Pathology, V.A. Medical Center and Baylor College of Medicine, Houston, TX.
Helicobacterpylori (Hp) is one of the most prevalent chronic infections worldwide and is strongly linked to peptic ulcer disease and gastric cancer. Major research efforts have focussed on genetic, seroepidemiologic, and host physiologic assays of this bacterium. Few studies have investigated its metabolism to identify physiologic factors that may be important for its survival in the unique ecological niche of the human stomach. Aim: To examine the expression of a panel of metabolic enzymes to assess those enzymes that may be important in Hp metabolism. Methods: Hp isolates were cultured from gastric biopsies from 73 individuals with duodenal ulcer disease, gastric ulcer disease, or histologic gastritis alone. Isolates were cultured in isosensitest broth supplemented with 10% horse serum at 37 C, 12% CO 2 for three days. At the time of harvest, all cultures demonstrated rod or spiral morphology on Gram stain and were positive for urease, catalase, and oxidase. After centrifugation the cells were lysed, and each isolate was examined for the expression of 17 housekeeping enzymes utilizing horizontal starch gel eleetrophoresis. Results: Although 17 metabolic enzymes normally found in many microbial organisms were assayed, only six were electropboretieally distinguishable. Sixty-three percent of strains had activity for all six enzymes, but at least one metabolic enzyme activity was absent in twentyeight (37%) of the strains. Moreover, in seventeen (60%) of these twentyeight strains, there was no glucose 6-phosphate dehydrogenase activity detected. Fifteen strains did not have detectable activity for glutamate dehydrogenase, isocitrate dehydrogenase, indophenol oxidase, nueleoside phosphorylase, or adenylate kinase. Conclusions: Compared to most human microbial organisms that have been examined, Hp exhibits a large degree ofgeactic heterogeneity in addition to extensive phenotypic diversity in the expression of many common metabolic enzymes. The apparent absence of important housekeeping enzymes suggests that Hp has a very unusual biology.
• MECHANISM OF Na+-DEPENDENT SECRETAGOGUE STIMULATED HCO 3" SECRETION BY BULLFROG DUODENAL MUCOSA. P.J. Goddard, D.I. Soybel+, S. Takahashi and W. Silen. Depts of Surgery, Beth Israel Hospital and Brigham and Woman's Hospital + , Harvard Medical School, Harvard Digestive Diseases Center, Boston, MA. In mammals and amphibians, secretagogue stimulated duodenal HCO3secretion depends on nutrient Na+. This Na+ requirement could be due to: I) Na+/H + exchange coupled to carbonic anhydrase catalyzed CO2 hydration; or 2) Na+(HCO3")n uptake. The first process would be inhibited by amiloride (Na+/H +) or acetazolamide (carbonic anhydrase); the second would be blocked by stilbene derivatives (DIDS). To evaluate these possibilities, duodenal mucosa from Rana catesbeiana was mounted in Ussing chambers and incubated with unbuffered 115 mM NaCI in the luminal (L) compartment. An amphibian Ringer's solution (24 mM HCO3" / 5% CO2). pH 7.4, was incubated in the nutrient (N) compartment. Luminal HCO 3- secretion was measured continuously using the pH-stat technique. After a 30-minute equilibration tissues were incubated with a Na+-free Ringer's solution (N), 1 mM amiloride .(N), 500 I.tM acetazolamide (L+N) or with 100 p.M D1DS (N). After a 90-minute incubation period either 1 p.M glueagon or 10 p.g/ml 16,16-dimethyl prostaglandin E2 (dmPGE2) was added to the nutrient solution. Rates of HCO3" secretion (Ixmol/hr-cm 2) are shown immediately before and 60minutes after the addition of a secretagogue. Data are expressed as the mean + SEM (n = 5 - 9 for each ~[roup, * p < 0.05 paired t-test). Glucagon droPGE2 Treatment Before After Before After Control 0.785:0.10 0.96:k0.09" 1.06+0.14 1.85:1:0.19" Na+ - Free 0.21=1:0.07 0.28+0.07 0.21-20.03 0.715:0.09" Amiloride 0.835:0.08 1.10:H).I5* 1.03+0.12 1.61+0.08" Acetazolamide 0.79+0.11 0.96+0.13" 0.735:0.10 1.835:0.22" DIDS 1.08+0.10 1.12+0.15 0.915:-0.13 1.145:0.13 Removal of Na+ from the nutrient solution significantly decreased spontaneous HCO3- secretion and attenuated or eliminated the response to both secretagogues. Treatment with DIDS but not with amiloride or acetazolamide abolished the increase in HCO3- secretion elicited by glncagon or by dmPGE 2. Conclusion: Both glucagon and prostaglandinstimulated duodenal HCO3- secretion depend on stilbene sensitive Na+dependent basolateral HCO3- uptake.
GASTROENTEROLOGY, Vol. 108, No. 4
• EFFECT OF OMEPRAZOLE ON THE DISTRIBUTION OF ANTIBIOTICS IN GASTRIC JUICE. A.F.(~oddard, MJ.Jessa, D.ABarrett, P.NShaw, J-P.IdstrOm, C.Wason, MWrangstadh, RCSpiller. Dept. of Medicine, University Hospital, Nottingham, NG7 2UH, UK. Omeprazole potentiates the anti-Helicobacter effect of amoxycillin (AMO) and clarithromycin (CLA). We tested the hypothesis that this is partly due to increased gastric drug delivery. MI~THODS: AMO 750 rag, CLA 500 rag, or Metronidazole (MET) 400 mg was given in randomised order as single doses either i.v. or p.o. to 24 healthy male subjects whilst taking placebo or omeprazole 40 mg b.d. in a cross-over design i.e. 8 subjects per antibiotic. Saliva and plasma samples were taken for 4 hours and 8 hours respectively. In the i.v. experiments gastric juice was aspirated continuously for 4 hours and 15 minute aliquots were quickly neutralised and frozen. Pyloric losses were measured using a phenol red marker. Antibiotic concentrations were measured in all samples by HPLC and Bioassay. The maximum concentration (Cv.,x) and area under concentration curve (AUC) were calculated for each antibiotic. RESULTS: Estimated means and 95% CI. Cv.~xin mg/L Gastric juice CK~x AMO CLA MET Placebo 0.18(0.07-0.48) 13.1 (8.2-21) 33(26-42) Omeprazole 0.55(0.21-1.5)* 10.6(6.7-17) 8.0(63-10)* Bioavallability % Placebo 80(60-100) 62(48-76) 91 (72-109) Omeprazole 84(64-100) 69(54-83) 102(84-121) +p=0.06,*p<0.0001 CONCLUSIONS: 1. AMO can be detected in gastric juice following i.v. dosing, and is found in higher concentrations during omeprazole treatment. 2. MET, but not CLA, secretion into gastric juice is reduced by omeprazole, probably because of differing pKa values. 3. Omeprazole treatment does not alter the absolute bioavailability of AMO, CLA, or MET.
DOES HELICOBACTER PYLORI INFECTION AFFECT GASTRIC EMPTYING IN PATIENTS WITH FUNCTIONAL DYSPEPSIA? KL Goh, M Paramsothy, M Azian, N Parasakthi, SC Peh, S Bux, KK Ong. Facul~ of Medicine, University of Malaya, Kuala Lumpur, Malaysia. The aim of the study was to determine if Helicobacter pylori (HP) infection affects gastric emptying in patients with functional dyspepsia (FD). Gastr']c emptying was measured using a 99 m technetium radiolabelled solid meal and gastric emptying time (GET) was measured as T 3/9 viz. time taken for half'the radiolabelled meal to be efdl~tied from the stomach. Two groups of patients with FD were recruited: HP + (n =20) and HP-(n = 19). A control group (n = 20) consisting of healthy asymptomatic HP- volunteers, liP status was determined in every patient by endoscopic biopsies taken and tested b~a rapid urease test, culture and histological examination and by a r*C urea breath test. G E T for HP+ patients was 56.4+24.8 min; HP- patients 67.8 + 31.8 rain and normal controls 58.8-+ 18.8 rain. No significant diffeTence was obtained between the groups (A.NOVA; p>0.25). Eighteen H P + patients received eradication therapy consisting of omeprazole 40rag om and amoxyciliin 500mg tds for 2 weeks. G E T was measured again, 4 weeks after completion of treatment. Posttreatment G E T for patients who had eradicated the infection (a= 13 ) was 74.0+44.5 rain and for patients who failed to eradicate the infection (n=5) 51.2+8.8 rain. No significant difference was obtained between pre- a~d post-treatment GETs (C.I.95%: -10.8 --> 31.1) and between GETs of patients who had eradicated or not eradicated HP (C.I. 95%: -66.1 --> 20.5). Gastric emptying was not different between patients with FD and normal controls. HP infection does not appear to affect gastric emptying in patients with FD.
AGA ABSTRACTS
• EXTENSIVE DIVERSITY IN METABOLIC-ENZYME PROFILES IN HEIJCOBACTER PYI.,ORL M.F. Go. V. Kaput, D.Y. Graham, J.MMusser. Depts. of Medicine and Pathology, V.A. Medical Center and Baylor College of Medicine, Houston, TX.
Helicobacterpylori (Hp) is one of the most prevalent chronic infections worldwide and is strongly linked to peptic ulcer disease and gastric cancer. Major research efforts have focussed on genetic, seroepidemiologic, and host physiologic assays of this bacterium. Few studies have investigated its metabolism to identify physiologic factors that may be important for its survival in the unique ecological niche of the human stomach. Aim: To examine the expression of a panel of metabolic enzymes to assess those enzymes that may be important in Hp metabolism. Methods: Hp isolates were cultured from gastric biopsies from 73 individuals with duodenal ulcer disease, gastric ulcer disease, or histologic gastritis alone. Isolates were cultured in isosensitest broth supplemented with 10% horse serum at 37 C, 12% CO 2 for three days. At the time of harvest, all cultures demonstrated rod or spiral morphology on Gram stain and were positive for urease, catalase, and oxidase. After centrifugation the cells were lysed, and each isolate was examined for the expression of 17 housekeeping enzymes utilizing horizontal starch gel eleetrophoresis. Results: Although 17 metabolic enzymes normally found in many microbial organisms were assayed, only six were electropboretieally distinguishable. Sixty-three percent of strains had activity for all six enzymes, but at least one metabolic enzyme activity was absent in twentyeight (37%) of the strains. Moreover, in seventeen (60%) of these twentyeight strains, there was no glucose 6-phosphate dehydrogenase activity detected. Fifteen strains did not have detectable activity for glutamate dehydrogenase, isocitrate dehydrogenase, indophenol oxidase, nueleoside phosphorylase, or adenylate kinase. Conclusions: Compared to most human microbial organisms that have been examined, Hp exhibits a large degree ofgeactic heterogeneity in addition to extensive phenotypic diversity in the expression of many common metabolic enzymes. The apparent absence of important housekeeping enzymes suggests that Hp has a very unusual biology.
• MECHANISM OF Na+-DEPENDENT SECRETAGOGUE STIMULATED HCO 3" SECRETION BY BULLFROG DUODENAL MUCOSA. P.J. Goddard, D.I. Soybel+, S. Takahashi and W. Silen. Depts of Surgery, Beth Israel Hospital and Brigham and Woman's Hospital + , Harvard Medical School, Harvard Digestive Diseases Center, Boston, MA. In mammals and amphibians, secretagogue stimulated duodenal HCO3secretion depends on nutrient Na+. This Na+ requirement could be due to: I) Na+/H + exchange coupled to carbonic anhydrase catalyzed CO2 hydration; or 2) Na+(HCO3")n uptake. The first process would be inhibited by amiloride (Na+/H +) or acetazolamide (carbonic anhydrase); the second would be blocked by stilbene derivatives (DIDS). To evaluate these possibilities, duodenal mucosa from Rana catesbeiana was mounted in Ussing chambers and incubated with unbuffered 115 mM NaCI in the luminal (L) compartment. An amphibian Ringer's solution (24 mM HCO3" / 5% CO2). pH 7.4, was incubated in the nutrient (N) compartment. Luminal HCO 3- secretion was measured continuously using the pH-stat technique. After a 30-minute equilibration tissues were incubated with a Na+-free Ringer's solution (N), 1 mM amiloride .(N), 500 I.tM acetazolamide (L+N) or with 100 p.M D1DS (N). After a 90-minute incubation period either 1 p.M glueagon or 10 p.g/ml 16,16-dimethyl prostaglandin E2 (dmPGE2) was added to the nutrient solution. Rates of HCO3" secretion (Ixmol/hr-cm 2) are shown immediately before and 60minutes after the addition of a secretagogue. Data are expressed as the mean + SEM (n = 5 - 9 for each ~[roup, * p < 0.05 paired t-test). Glucagon droPGE2 Treatment Before After Before After Control 0.785:0.10 0.96:k0.09" 1.06+0.14 1.85:1:0.19" Na+ - Free 0.21=1:0.07 0.28+0.07 0.21-20.03 0.715:0.09" Amiloride 0.835:0.08 1.10:H).I5* 1.03+0.12 1.61+0.08" Acetazolamide 0.79+0.11 0.96+0.13" 0.735:0.10 1.835:0.22" DIDS 1.08+0.10 1.12+0.15 0.915:-0.13 1.145:0.13 Removal of Na+ from the nutrient solution significantly decreased spontaneous HCO3- secretion and attenuated or eliminated the response to both secretagogues. Treatment with DIDS but not with amiloride or acetazolamide abolished the increase in HCO3- secretion elicited by glncagon or by dmPGE 2. Conclusion: Both glucagon and prostaglandinstimulated duodenal HCO3- secretion depend on stilbene sensitive Na+dependent basolateral HCO3- uptake.
GASTROENTEROLOGY, Vol. 108, No. 4
• EFFECT OF OMEPRAZOLE ON THE DISTRIBUTION OF ANTIBIOTICS IN GASTRIC JUICE. A.F.(~oddard, MJ.Jessa, D.ABarrett, P.NShaw, J-P.IdstrOm, C.Wason, MWrangstadh, RCSpiller. Dept. of Medicine, University Hospital, Nottingham, NG7 2UH, UK. Omeprazole potentiates the anti-Helicobacter effect of amoxycillin (AMO) and clarithromycin (CLA). We tested the hypothesis that this is partly due to increased gastric drug delivery. MI~THODS: AMO 750 rag, CLA 500 rag, or Metronidazole (MET) 400 mg was given in randomised order as single doses either i.v. or p.o. to 24 healthy male subjects whilst taking placebo or omeprazole 40 mg b.d. in a cross-over design i.e. 8 subjects per antibiotic. Saliva and plasma samples were taken for 4 hours and 8 hours respectively. In the i.v. experiments gastric juice was aspirated continuously for 4 hours and 15 minute aliquots were quickly neutralised and frozen. Pyloric losses were measured using a phenol red marker. Antibiotic concentrations were measured in all samples by HPLC and Bioassay. The maximum concentration (Cv.,x) and area under concentration curve (AUC) were calculated for each antibiotic. RESULTS: Estimated means and 95% CI. Cv.~xin mg/L Gastric juice CK~x AMO CLA MET Placebo 0.18(0.07-0.48) 13.1 (8.2-21) 33(26-42) Omeprazole 0.55(0.21-1.5)* 10.6(6.7-17) 8.0(63-10)* Bioavallability % Placebo 80(60-100) 62(48-76) 91 (72-109) Omeprazole 84(64-100) 69(54-83) 102(84-121) +p=0.06,*p<0.0001 CONCLUSIONS: 1. AMO can be detected in gastric juice following i.v. dosing, and is found in higher concentrations during omeprazole treatment. 2. MET, but not CLA, secretion into gastric juice is reduced by omeprazole, probably because of differing pKa values. 3. Omeprazole treatment does not alter the absolute bioavailability of AMO, CLA, or MET.
DOES HELICOBACTER PYLORI INFECTION AFFECT GASTRIC EMPTYING IN PATIENTS WITH FUNCTIONAL DYSPEPSIA? KL Goh, M Paramsothy, M Azian, N Parasakthi, SC Peh, S Bux, KK Ong. Facul~ of Medicine, University of Malaya, Kuala Lumpur, Malaysia. The aim of the study was to determine if Helicobacter pylori (HP) infection affects gastric emptying in patients with functional dyspepsia (FD). Gastr']c emptying was measured using a 99 m technetium radiolabelled solid meal and gastric emptying time (GET) was measured as T 3/9 viz. time taken for half'the radiolabelled meal to be efdl~tied from the stomach. Two groups of patients with FD were recruited: HP + (n =20) and HP-(n = 19). A control group (n = 20) consisting of healthy asymptomatic HP- volunteers, liP status was determined in every patient by endoscopic biopsies taken and tested b~a rapid urease test, culture and histological examination and by a r*C urea breath test. G E T for HP+ patients was 56.4+24.8 min; HP- patients 67.8 + 31.8 rain and normal controls 58.8-+ 18.8 rain. No significant diffeTence was obtained between the groups (A.NOVA; p>0.25). Eighteen H P + patients received eradication therapy consisting of omeprazole 40rag om and amoxyciliin 500mg tds for 2 weeks. G E T was measured again, 4 weeks after completion of treatment. Posttreatment G E T for patients who had eradicated the infection (a= 13 ) was 74.0+44.5 rain and for patients who failed to eradicate the infection (n=5) 51.2+8.8 rain. No significant difference was obtained between pre- a~d post-treatment GETs (C.I.95%: -10.8 --> 31.1) and between GETs of patients who had eradicated or not eradicated HP (C.I. 95%: -66.1 --> 20.5). Gastric emptying was not different between patients with FD and normal controls. HP infection does not appear to affect gastric emptying in patients with FD.