bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alanine aminotransferase catalyses the breakdown of alanine after hypoxia in Arabidopsis thaliana
Authors: Miyashita Yo , Dolferus Rudy , Ismond Kathleen P. , Good Allen G. 
Published: February 2007

SummaryAlanine aminotransferase (AlaAT) catalyses the reversible transfer of an amino group from glutamate to pyruvate to form 2‐oxoglutarate and alanine. The regulation of AlaAT in several plant species has been studied in response to low‐oxygen stress, light and nitrogen application. In this study, induction of Arabidopsis AlaAT1 and AlaAT2 during hypoxia was observed at the transcriptional level, and an increase in enzyme activity was detected in hypoxically treated roots. In addition, the tissue‐specific expression of AlaAT1 and AlaAT2 was analysed using promoter:GUS fusions. The GUS staining patterns indicated that both AlaAT genes are expressed predominantly in vascular tissues. We manipulated AlaAT expression to determine the relative importance of this enzyme in low‐oxygen stress tolerance and nitrogen metabolism. This was done by analysing T‐DNA mutants and over‐expressing barley AlaAT in Arabidopsis. The AlaAT1 knockout mutant (alaat1‐1) showed a dramatic reduction in AlaAT activity, suggesting that AlaAT1 is the major AlaAT isozyme in Arabidopsis. Over‐expression of barley AlaAT significantly increased the AlaAT activity in the transgenic plants. These plants were analysed for metabolic changes over a period of hypoxic stress and during their subsequent recovery. The results showed that alaat1‐1 plants accumulate more alanine than wild‐type plants during the early phase of hypoxia, and the decline in accumulated alanine was delayed in the alaat1‐1 line during the post‐hypoxia recovery period. When alanine was supplied as the nitrogen source, alaat1‐1 plants utilized alanine less efficiently than wild‐type plants did. These results indicate that the primary role of AlaAT1 is to break down alanine when it is in excess. Therefore, AlaAT appears to be crucial for the rapid conversion of alanine to pyruvate during recovery from low‐oxygen stress.
Culture of Helicobacter pylori: Effect of Preimmersion of Biopsy Forceps in Formalin
Authors: Yousfi Mahmoud M. , Reddy Rita , Osato Michael S. , Graham David Y. 
Published: February 2007

ABSTRACT Background.Treatment of antibiotic‐resistant Helicobacter pylori should be based on bacterial sensitivity testing that requires the ability to isolate the bacterium from gastric mucosal biopsies. The aim of this study was to determine whether the yield for detecting H. pylori infection by culture is reduced by immersion of biopsy forceps in formalin prior to obtaining the specimen. Materials and Methods.Gastric antral mucosal biopsies (100 specimens) from 50 patients were obtained for culture of H. pylori. An antral biopsy was taken for culture, and with the same forceps a biopsy was taken for histological examination. The biopsy specimen was removed by shaking, whereas the forceps was immersed in 10% buffered formalin for the histological investigation. The forceps was then used without rinsing to obtain a second specimen for culture from an area adjacent to the first site. H. pylori status was determined by histological assessment with the Genta stain and a rapid urease test. Results.Fifty patients with H. pylori infection documented by histological inquiry and positive rapid urease testing entered the study; 29 had duodenal ulcers, 5 had gastric ulcers, 1 had mucosal associated lymphoid tissue (MALT) lymphoma, and 15 were without ulcer disease. The results of culture both before and after immersion in formalin were identical. One patient had both cultures negative; the sensitivity of culture for detection of H. pylori infection was 98% (95% confidence interval =93%‐100%). Conclusion. Preimmersion of biopsy forceps in formalin does not adversely affect the ability to culture H. pylori.
Comparison of One or Two Weeks of Lansoprazole, Amoxicillin, and Clarithromycin in the Treatment of Helicobacter pylori
Authors: Moayyedi Paul , Langworthy Harriet , Shanahan Kate , Tompkins David S. , Dixon Michael F. , Chalmers Douglas M. , Axon Anthony T. R. 
Published: February 2007

ABSTRACT BackgroundThe simplest, most effective, and least expensive Helicobacter pylori therapy remains to be determined. Two weeks of 30 mg lansoprazole bid, 1 gm amoxicillin bid, and 500 mg clarithromycin bid (LAC2) had been shown to be an effective therapy for H. pylori. The aim of this study was to assess whether 1 week of this regimen (LAC1) would have a similar efficacy. Materials and Methods.
H. pylori‐positive patients assessed histologically, by rapid urease test, microbiologically, and by a 13C‐urea breath test (13C‐UBT) were randomized to receive either LAC1 or LAC2 in a single‐center open study. Patients were interviewed 1 to 3 days after completion of therapy to evaluate adverse events and compliance. Efficacy was determined by 13C‐UBT at least 4 weeks after antibiotic therapy. Results.Seventy evaluable patients were randomized to receive LAC1 (n = 33) and LAC2 (n = 37). Of the 33 LAC1 patients, 30 (91%) were treated successfully (95% confidence interval (CI) = 76–98%), compared with 32 of 37 (86%) in the LAC2 group (95% CI = 71–96%). There was no difference in efficacy between the two groups (Fisher's exact test p= 1.0; 95% CI =–10.3%–19.2%). Patients taking LAC1 experienced significantly fewer severe adverse events than those taking LAC2 (Mann‐Whitney U test). One of 64 patients had primary resistance to clarithromycin, and treatment was unsuccessful in this case. Six of the 7 remaining treatment failures developed secondary resistance to clarithromycin. Conclusions.LAC1 is as effective as LAC2 and is associated with less toxicity. Posttreatment clarithromycin resistance is common in patients who do not experience success with therapy.
Helicobacter pylori Infection in Congestive Gastropathy
Authors: Bahnacy A. , Kupcsulik P. , Elés Zs , Jàray B. , Flautner L. 
Published: February 2007

ABSTRACT Background.This study determines the prevalence and significance of Helicobacter pylori infection in portal hypertensive patients. Materials and Methods.Patients numbered 118 and consisted of 90 patients with portal hypertension (66 men; 24 women; mean age, 49.1 ± 2.1 years) and 28 noncirrhotic patients with nonucler dyspepsia, (12 men; 16 women; mean age, 47.6 ± 2.8 years), who made up the control group. In all patients, diagnostic upper endoscopy was performed, and gastric biopsies were taken for histological examination and diagnosis of H. pylori. Results.Of the portal hypertensive patients, 42 (47%) had congestive gastropathy, 11 (26%) of whom were positive for H. pylori. and 48 (53%) did not have gastropathy, 12 (25%) of whom were positive for H. pylori. In the control group, 15 of 28 (54%) were positive for H. pylori. H. Pylori was found less frequently in congestive gastropathy patients than in the control group. We found also that the presence and severity of congestive gastropathy is independent of H. pylori status. Conclusions.We conclude that the role of H. pylori in the pathogenesis of congestive gastropathy is unlikely, and we suggest that there is no need for its routine eradication in cirrhotic patients.
Triple Therapy with Lansoprazole, Clarithromycin, and Amoxicillin for the Cure of Helicobacter pylori Infection: A Short Report
Authors: Riff Dennis S. , Kidd S. , Rose Pamela , Haber Marian , Weissfeld Alice , Siepman Nancy 
Published: February 2007

ABSTRACT BackgroundGiven the therapeutic potential of proton pump inhibitor‐based triple therapy for successful cure of Helicobacter pylori infection, we evaluated the efficacy and safety of lansoprazole with clarithromycin and amoxicillin in an open‐label, single‐center study. Materials and Methods.
H. pylori‐positive patients self‐administered lansoprazole, 30 mg; clarithromycin, 500 mg; and amoxicillin, 1 gm bid for 14 days. Patients were assessed pretreatment, at which time the presence of H. pylori was documented by rapid urease test, culture, or histology, following study drug administration (week 2) for a brief evaluation only, and at least 4 weeks posttreatment (week 6), which included endoscopy with collection of biopsy specimens for culture and histology testing. Results.Primary clarithromycin and metronidazole resistance were observed in 6% (2 of 30) and 43% (13 of 30) of study patients, respectively. One month after the end of therapy, H. pylori infection was cured in 23 of 25 patients (92%; 95% confidence interval, 74%‐99%). The triple‐therapy regimen was well‐tolerated; 17% of patients (5 of 30) reported mild to moderate adverse effects during the treatment period. Conclusion.A 2‐week, triple‐drug combination of lansoprazole, clarithromycin, and amoxicillin is highly effective for cure of H. pylori infection. Additionally, the triple‐drug combination was well‐tolerated by patients infected with H. pylori.
Seven‐Day Triple Therapy with Lansoprazole, Clarithromycin, and Metronidazole for the Cure of Helicobacter pylori Infection: A Short Report
Authors: Schwartz Howard , Krause R. , Siepman Nancy , Haber Marian , Weissfeld Alice , Kid S. , Rose Pamela , Sahba B. 
Published: February 2007

ABSTRACT BackgroundTo refine our understanding of anti‐Helicobacter pylori treatment regimens further, we evaluated the efficacy and safety of lansoprazole given in combination with clarithromycin and metronidazole for 7 days in an open‐label, multicenter study. Materials and Methods.
H. pylori‐positive patients self‐administered lansoprazole, 30 mg; clarithromycin, 500 mg; and metronidazole, 500 mg bid for 7 days. Patients were assessed at pretreatment, at which time the presence of H. pylori was documented by rapid urease test or histology and culture, following study drug administration (week 1) for a brief evaluation only, and at least 4 weeks posttreatment (week 5), including endoscopy with collection of biopsy specimens for culture and histology testing. Results.Of the 60 patients enrolled in the study, 59 had confirmed H. pylori infection, and 51 were included in an intent‐to‐treat analysis of efficacy. Primary metronidazole and clarithromycin resistance were observed in 84% and 8% of study patients, respectively. One month after the end of therapy, H. pylori infection was cured in 40 of 51 patients (78%); 95% confidence interval, 65%–89%). The triple‐therapy regimen was well‐tolerated, with only 2 patients (4%) requiring premature withdrawal from the study due to treatment‐related adverse events. Taste perversion (15.0%) and diarrhea (11.7%) were the most frequently reported adverse events possibly or probably related to study medication during the treatment period. Conclusion.Despite a high prevalence of metronidazole resistance, a 1‐week, triple‐drug combination of lansoprazole, clarithromycin, and metronidazole is effective treatment for and well‐tolerated by patients with H. pylori infection.
Comparative Evaluation of Selective and Nonselective Media for Primary Isolation of Helicobacter pylori from Gastric Biopsies
Authors: Martínez María José Fresnadillo , Rincón Manuel Rodríguez , De Castro Ana María Blázquez , Sánchez Enrique García , Sánchez José E. García , Martín Ignacio Trujillano , Sánchez Miguel Cordero , Alvarez Pedro Alvarez , Bouza José Paz , García‐Rodríguez José A. 
Published: February 2007

Background.In this study, we compared and evaluated the efficacy of five culture media for the primary isolation of Helicobacter pylori from gastric biopsies.Materials and Methods.A total of 1,174 biopsies (antrum and corpus) taken from 587 patients were plated in parallel on two selective media—Skirrow’s medium and brain‐heart infusion (BHI) agar supplemented with 10% sheep blood, polymyxin B, vancomycin, trimethoprim, and amphotericin B (HPA medium), and on three nonselective media—chocolate agar with Isovitalex, Columbia blood agar, and BHI‐10% sheep blood agar.Results.An isolation rate of 57.9% (680 of 1,174) was obtained with a combination of all media. HPA medium gave the highest isolation rate, 99.4% (676 of 680). Chocolate agar, Columbia blood agar, brain‐heart blood agar, and Skirrow’s medium showed very poor performance (23.5%, 28.5%, 65.9%, and 71% of all isolates, respectively). The number of cultures in HPA medium discarded due to contamination was only 2 (0.32%). There was no difference in the positive rate of culture in HPA medium between the antrum and the corpus of the stomach.Conclusions.The HPA medium is superior to Skirrow’s medium and nonselective media in promoting growth of H. pylori and, on the basis of these results, we recommended the use of HPA medium for primary isolation of H. pylori from gastric biopsies.
Invasive Helicobacter‐Like Organisms in Feline Gastric Mucosa
Authors: Serna Jorge Humberto , Genta Robert M. , Lichtenberger L.M. , Graham David Y. , El‐Zaatari Fouad A.K. 
Published: February 2007

Background. Helicobacter‐like organisms (HLOs) usually are present in the stomachs of cats. Although the histopathology of natural (H. felis or H. heilmannii) infections has been reported, their invasion into the lymphoid aggregates has not been described previously.Materials and Methods.Gastric tissues were obtained from 17 adult cats living in a natural urban environment. Biopsy sites were selected by the presence of urease on the mucosal surface stained by Genta stain and periodic acid–Schiff stain.Results.Spiral organisms morphologically similar to H. felis or to H. heilmannii were detected in all the cats, distributed predominantly over the oxyntic mucosa. Seven cats had prominent lymphoid follicles with germinal centers within the oxyntic mucosa, and in six of these seven cats, extracellular organisms were present within the lymphoid follicles. Scattered organisms also were found over sites of gastric metaplasia in the duodenum of six cats.Conclusions.This study extends previous observations by showing that HLO infection in cats is associated with large lymphoid follicles in the stomach. In additon, HLOs were demonstrated submucosally within gastric lymphoid follicles and on patches of gastric metaplasia in the duodenum.
Ranitidine Bismuth Citrate with Clarithromycin for the Eradication ofHelicobacter pyloriand for Ulcer Healing
Authors: Pounder Roy E. , Wyeth John W. , Duggan Annette E. , Bailey Robert J. , Louw Japie A. , Ohlin Bo 
Published: February 2007

Background.In a pilot study, ranitidine bismuth citrate (RBC; Pylorid, Tritec) in coprescription with clarithromycin achieved aHelicobacter pylorieradication rate (based on13C urea breath test alone) of 83%. The aim of the current study was to validate this finding by using three diagnostic tests and a larger group ofH. pylori–positive patients with active duodenal ulcer.Methods.In a blinded study, 95 patients were given either 4 weeks of treatment with RBC, 400 mg bid, alone (RBC400, n = 31) or RBC, 400 mg bid or 800 mg bid, in coprescription with clarithromycin, 250 mg qid for 14 days, followed by 14 days of RBC, 400 mg bid, alone (RBC400+CLAR and RBC800+CLAR, respectively; n = 32 for each). Rates of ulcer healing at week 4 and ofH. pylorieradication (assessed by antral and corpus urease tests and histology and by13C urea breath test) at week 8 were compared, together with the incidence of adverse events.Results.All three regimens were effective at duodenal ulcer healing and were tolerated well. The coprescription regimens gave significantly higher observedH. pylorieradication rates (82% and 74% for RBC400+ CLAR and RBC800+CLAR) compared with RBC400 (0%;p< .001).Conclusions.RBC in dual therapy with clarithromycin provides excellentH. pylorieradication therapy and is an effective duodenal ulcer healing drug.
Relationship Between the Eff icacy of Amoxicillin and Intragastric pH for the Treatment of Helicobacter pylori Infection
Authors: Kleveland Per M. , Waldum Helge L. , Brenna Eiliv , Aase Steinar , Mæland Johan A. 
Published: February 2007

Background.Proton pump inhibitors are reported to enhance the efficacy of antibiotics in the treatment of Helicobacter pylori infection. An elevated intragastric pH is considered to be an important factor for this increased antimicrobial efficacy. The aim of this study was to assess the effect of different doses of lansoprazole on 24‐hour intragastric pH and to correlate the effect of amoxicillin on the cure rate for H. pylori infection with the intragastric pH obtained during lansoprazole treatment.Patients and Methods.Thirty‐six duodenal ulcer patients who tested postively for H. pylori as assessed by a rapid urease test, culture, and histological evaluation were allocated randomly to dual treatment with amoxicillin, 3 gm/day, and lansoprazole in different doses ranging between 30 and 180 mg/day for 2 weeks. A 24‐hour intragastric pH measurement was taken in all patients on the fifth day of treatment. H. pylori status was determined by culture and histological workup 6 weeks after cessation of the amoxicillin‐lansoprazole medication.Results.The H. pylori infection was treated successfully in 19 of 32 patients who completed the dual therapy (per protocol, 59.4%). The median intragastric pH in patients who were treated successfully was 4.4 (95% confidence interval [CI] = 3.7– 4.7), as compared to 4.0 (95% CI = 3.5– 4.5) in patients who were not treated successfully ( p = .47, Wilcoxon’s rank sum test). The median percentage of time that the intragastric pH exceeded 4 was not different in the two groups ( p = .77). Administration of lansoprazole in doses exceeding 30 mg induced only a moderate additional increase in intragastric pH.Conclusions.Profound inhibition of gastric acid secretion seems not to be necessary to improve the effect of amoxicillin on the cure rate for H. pylori infection in patients with duodenal ulcers.
Helicobacter pylori Genotypes Inf luence Serum Pepsinogen C Levels
Authors: Plebani Mario , Basso Daniela , Navaglia Filippo , DiMario Francesco 
Published: February 2007

Background.Infection from Helicobacter pylori significantly influences pepsinogen A (PGA) and C (PGC) levels in serum. Increased PGA and PGC serum levels are observed in H. pylori positive patients, while a significant decrease is observed after eradication. Little is known about the relative role of H. pylori cytotoxic strains in this phenomenon. The aim of our study was to assess the influence of cagA genotype on circulating levels of PGA and PGC.Materials and Methods.We studied 81 consecutive H. pylori positive patients, 64 H. pylori negative patients and 18 healthy controls. H. pylori was evaluated histologically in two antral and two body biopsies (Giemsa and/or Warthin Starry staining). Extracted DNA was then submitted for PCR amplification of both the urease A and cagA genes. A serum obtained from each patient before endoscopy was used for specific radioimmunoassay measurement of PGA and PGC.Results.The urease A gene was found in all H. pylori positive patients, the cagA gene was detected in 55 H. pylori positive patients and in none of the H. pylori negative patients. PGA and PGC levels were significantly higher in H. pylori positive than in H. pylori negative patients. A significant association was found between cagA and raised serum PGC levels in patients with antral gastritis but not in patients with peptic ulcer. Serum PGA levels were not affected by cagA.Conclusions.Our results indicate that cagA positivity may influence the circulating PGC levels, probably because it causes a higher grade of mucosal inflammation.
No Additional Value of Bismuth Subcitrate to Combination Omeprazole/Amoxicillin Therapy in the Eradication of Helicobacter pylori
Authors: Tan A.C.I.T.L. , Den Hartog G. , Meijer J.W.R. , Thies J.E. , De Vries R.A. , Mulder C.J.J. 
Published: February 2007

Background.We investigated whether addition of bismuth subcitrate (BSC, 4 × 120 mg) to a two week therapy scheme of omeprazole (OME, 2 × 40 mg)/amoxicillin (AMO, 4 × 500 mg) increases Helicobacter pylori eradication.Materials and Methods.Patients with dyspepsia underwent upper endoscopy. H. pylori positive patients were randomized to treatment A (OME/AMO, 83 patients) or treatment B (OME/AMO/BSC, 84 patients).Results.In 65 patients of group A (78%) H. pylori was eradicated as determined from the histological assessment (Sydney classification) of antrum and corpus biopsies. In comparison, in 68 patients of group B (81%) H. pylori was eradicated (p = NS between groups). H. pylori eradication in both groups was associated similarly with a decrease of inflammation and activity whereas atrophy and intestinal metaplasia were not affected. A positive association was revealed between the decrease of H. pylori score and the decrease of both inflammation and activity scores for antrum as well as corpus biopsies.Conclusions.Addition of BSC to OME/AMO does not increase H. pylori eradication in patients with dyspepsia. Eradication of H. pylori is associated with disappearance of epithelial damage (inflammation and activity) in antral and corpus mucosa.
Co‐Existing Gastric Cancer and Duodenal Ulcer Disease: Role of Helicobactor pylori Infection
Authors: Kim Hak Yang , Kim Yong Bum , Park Choong Kee , Yoo Jae Young , Graham David Y. 
Published: February 2007

Background.The association of gastric cancer and chronic duodenal ulcer disease is considered rare. In fact duodenal ulcer disease is believed to somehow “protect” against the development of gastric cancer. Helicobacter pylori infection is an important factor in the development of gastric cancer. No detailed investigation on the prevalence of H.pylori in coexistence of gastric cancer and duodenal ulcer disease has been performed. We evaluated the frequency of H. pylori infection in the patients with co‐existence of gastric cancer and duodenal ulcer disease.Materials and Methods.During the period March 1994 to February 1995, we collected data from 3,652 patients in whom esophagogastroduodenoscopy was done. During this period, when the cancerous or ulcerative lesions in stomach or duodenum were found, rapid urease tests were performed.Results.Six patients had concurrent gastric carcinoma and duodenal ulcer disease. Three of the cases had early gastric carcinoma; 2 had active duodenal ulcers and one had a duodenal ulcer scar; all 3 had positive rapid urease tests. The patients with early gastric cancer were younger than the individuals with advanced gastric cancer.Conclusions.The co‐existence of both diseases may be higher than reported from Western countries or from Peru which may either reflect the high prevalence of circulation of H.pylori ulcer and cancer strains in Korea and the co‐infection with both types of organism in some individuals.