Alba Rocco

Empirical levofloxacin-containing versus clarithromycin-containing sequential therapy for Helicobacter pylori eradication: a randomised trial

Background and aims Antimicrobial drug resistance is a major cause of the failure of Helicobacter pylori eradication and is largely responsible for the decline in eradication rate. Quadruple therapy has been suggested as a first-line regimen in areas with clarithromycin resistance rate >15%. This randomised trial aimed at evaluating the efficacy of a levofloxacin-containing sequential regimen in the eradication of H pylori-infected patients in a geographical area with >15% prevalence of clarithromycin resistance versus a clarithromycin-containing sequential therapy. Methods 375 patients who were infected with H pylori and naïve to treatment were randomly assigned to one of the following treatments: (1) 5 days omeprazole 20 mg twice daily + amoxicillin 1 g twice daily followed by 5 days omeprazole 20 mg twice daily + clarithromycin 500 mg twice daily + tinidazole 500 mg twice daily; or (2) omeprazole 20 mg twice daily + amoxicillin 1 g twice daily followed by omeprazole 20 mg twice daily + levofloxacin 250 mg twice daily + tinidazole 500 mg twice daily; or (3) omeprazole 20 mg twice daily + amoxicillin 1 g twice daily followed by omeprazole 20 mg twice daily + levofloxacin 500 mg twice daily + tinidazole 500 mg twice daily. Antimicrobial resistance was assessed by the E-test. Efficacy, adverse events and costs were determined for each group. Results Eradication rates in the intention-to-treat analyses were 80.8% (95% CI, 72.8% to 87.3%) with clarithromycin sequential therapy, 96.0% (95% CI, 90.9% to 98.7%) with levofloxacin-250 sequential therapy, and 96.8% (95% CI, 92.0% to 99.1%) with levofloxacin-500 sequential therapy. No differences in prevalence of antimicrobial resistance or incidence of adverse events were observed between groups. Levofloxacin-250 therapy was cost-saving compared with clarithromycin sequential therapy. Conclusion In an area with >15% prevalence of clarithromycin resistant H pylori strains, a levofloxacin-containing sequential therapy is more effective, equally safe and cost-saving compared to a clarithromycin-containing sequential therapy.

Expression of COX-2, mPGE-synthase1, MDR-1 (P-gp), and Bcl-xL: a molecular pathway of H pylori-related gastric carcinogenesis.

Helicobacter pylori up‐regulates cyclo‐oxygenase‐2 (COX‐2) expression, which in turn is involved in tumourigenesis. Recently, a causal link between COX‐2 and multidrug resistance 1 (MDR‐1) gene expression, implicated in cancer chemoresistance, has been demonstrated. Thus, the expression of COX‐2 and the downstream enzyme involved in PGE2 biosynthesis, microsomal PGE‐synthase1 (mPGES1), was correlated with P‐gp, the product of MDR‐1, and the anti‐apoptotic protein, Bcl‐xL, in gastric biopsies from patients with H pylori infection and in patients with gastric cancer. In a retrospective analysis of endoscopic and pathology files, 40 H pylori‐negative patients (Hp−), 50 H pylori‐positive patients who responded to eradication therapy (Hp+R), 84 H pylori‐positive patients who did not respond to eradication therapy (Hp+NR), and 30 patients with gastric cancer (18 intestinal and 12 diffuse types) were selected. COX‐2, mPGES1, P‐gp, and Bcl‐xL were detected by immunohistochemistry. COX‐2, mPGES1, P‐gp, and Bcl‐xL expression was undetectable in gastric mucosa from Hp− patients. By contrast, COX‐2 and mPGES1 expression was detected in 42% and 44% of Hp+R patients, respectively, and in up to 66% (range 63–66%) of Hp+NR patients (p < 0.05). The expression of COX‐2 and mPGES1 correlated significantly (p < 0.0001) with that of P‐gp and Bcl‐xL. High levels of COX‐2, mPGES1, P‐gp, and Bcl‐xL expression were found in intestinal‐type gastric cancer samples. In conclusion, H pylori‐dependent induction of COX‐2 and mPGES1 is associated with enhanced production of P‐gp and Bcl‐xL that may contribute to gastric tumourigenesis and resistance to therapy. Copyright

Failure of first-line eradication treatment significantly increases prevalence of antimicrobial-resistant Helicobacter pylori clinical isolates

Objectives: Helicobacter pylori infection is a major health problem worldwide, and effective eradication of the infection is mandatory. The efficacy of recommended eradication regimens is approximately 70%. To avoid treatment failure and the consequent development of secondary resistance(s), it is important to choose the most appropriate first-line treatment regimen. This choice should also be made based on the knowledge of the antimicrobial resistance peculiar to a given geographical area. We evaluated the prevalence of antimicrobial-resistant H pylori strains isolated from naive patients and from patients with previous unsuccessful treatments. Methods: This study examined 109 H pylori-infected subjects (Group 1) who had never received an eradication treatment and 104 H pylori-infected subjects (Group 2) who had failed one or more eradication treatments. Resistance to amoxicillin (AMO), tetracycline (TET), clarithromycin (CLA), metronidazole (MET) and levofloxacin (LEV) was determined using the epsilometer test. The significance of differences was evaluated by the χ2 test. Results: The prevalence of antimicrobial resistance was 0% versus 3.1% to AMO, 0% versus 2% to TET, 27% versus 41.3% to MET (p<0.05), 18% versus 45.8% to CLA (p<0.05) and 3% versus 14.6% to LEV (p<0.05) in Group 1 vs Group 2, respectively. In Group 2, there was an increased prevalence of H pylori strains resistant to multiple antimicrobials. Conclusions: This study confirms the high prevalence of H pylori strains resistant to CLA and MET, and indicates that unsuccessful treatments significantly increase resistance. Choosing eradication regimens other than standard triple therapy as a first-line therapy should be advisable in areas with high primary antimicrobial resistance prevalence.

Effects of long‐term PPI treatment on producing bowel symptoms and SIBO

Eur J Clin Invest 2011; 41 (4): 380–386

Expression of carbonic anhydrase 9 at the invasion front of gastric cancers

Background: Carbonic anhydrase IX (MN/Ca9) catalyses the reversible metabolism of carbon dioxide to carbonic acid and has also been linked to malignant transformation and hypoxia in various cancers. Aims: To assess the expression and biological role of Ca9 in gastric cancer. Methods: Using gastric cancer cell lines and tissues, we studied expression of Ca9 by western blot analysis, immunohistochemistry, and polymerase chain reaction. Biological changes after Ca9 transfection and after treatment with 5′-azadeoxycytidine were also analysed in cancer cell lines. Results: Non-cancerous tissues strongly expressed Ca9 with membranous localisation. In contrast, Ca9 expression was frequently lost in gastric cancers (p<0.001). However, gastric cancers that retained Ca9 expression in cancer cells exhibited a shorter postoperative survival (p = 0.028). In vitro analysis revealed that loss of Ca9 expression in gastric cancer cell lines was restored after treatment with 5′-azadeoxycytidine and was associated with increased invasion (p<0.01). Moreover, AGS cells transfected with Ca9 exhibited significantly increased cell proliferation (p<0.05). Conclusions: A subgroup of gastric cancers retain Ca9 expression in cancer cells at the invasion front. While loss of Ca9 expression is regulated in part by methylation, re-expression of Ca9 is associated with increased invasion, supporting the hypothesis that increased Ca9 expression may contribute to invasion and thus advanced disease and tumour progression in a subset of gastric cancers.

Efficacy of 5-Day Levofloxacin-Containing Concomitant Therapy in Eradication of Helicobacter pylori Infection

BACKGROUND & AIMS Helicobacter pylori have become resistant to antimicrobial agents, reducing eradication rates. A 10-day sequential regimen that contains levofloxacin was efficient, safe, and cost saving in eradicating H pylori infection in an area with high prevalence of clarithromycin resistance. We performed a noninferiority randomized trial to determine whether a 5-day levofloxacin-containing quadruple concomitant regimen was as safe and effective as the 10-day sequential regimen in eradicating H pylori in previously untreated patients. METHODS We randomly assigned patients with H pylori infection to groups that were given 5 days of concomitant therapy (esomeprazole 40 mg twice daily, amoxicillin 1 g twice daily, levofloxacin 500 mg twice daily, and tinidazole 500 mg twice daily; n = 90) or 10 days of sequential therapy (esomeprazole 40 mg twice daily, amoxicillin 1g twice daily for 5 days followed by esomeprazole 40 mg twice daily, levofloxacin 500 mg twice daily, and tinidazole 500 mg twice daily for 5 more days; n = 90). Antimicrobial resistance was assessed by the E-test. Efficacy, adverse events, and costs were determined. RESULTS Intention-to-treat analysis showed similar eradication rates for concomitant (92.2%; 95% confidence interval [CI], 84.0%-95.8%) and sequential therapies (93.3%; 95% CI, 86.9%-97.3%). Per-protocol eradication results were 96.5% (95% CI, 91%-99%) for concomitant therapy and 95.5% for sequential therapy (95% CI, 89.6%-98.5%). The differences between sequential and concomitant treatments were 1.1% in the intention-to-treat study (95% CI; -7.6% to 9.8%) and -1.0% in the per-protocol analysis (95% CI; -8.0% to 5.9%). The prevalence of antimicrobial resistance and incidence of adverse events were comparable between groups. Concomitant therapy cost

Protective effects of Lactobacillus paracasei F19 in a rat model of oxidative and metabolic hepatic injury

9 less than sequential therapy. CONCLUSIONS Five days of levofloxacin-containing quadruple concomitant therapy is as effective and safe, and less expensive, in eradicating H pylori infection than 10 days of levofloxacin-containing sequential therapy.

Increased mucosal nitric oxide production in ulcerative colitis is mediated in part by the enteroglial‐derived S100B protein

The liver is susceptible to such oxidative and metabolic stresses as ischemia-reperfusion (I/R) and fatty acid accumulation. Probiotics are viable microorganisms that restore the gut microbiota and exert a beneficial effect on the liver by inhibiting bacterial enzymes, stimulating immunity, and protecting intestinal permeability. We evaluated Lactobacillus paracasei F19 (LP-F19), for its potential protective effect, in an experimental model of I/R (30 min ischemia and 60 min reperfusion) in rats fed a standard diet or a steatogen [methionine/choline-deficient (MCD)] diet. Both groups consisted of 7 sham-operated rats, 10 rats that underwent I/R, and 10 that underwent I/R plus 8 wk of probiotic dietary supplementation. In rats fed a standard diet, I/R induced a decrease in sinusoid perfusion (P < 0.001), severe liver inflammation, and necrosis besides an increase of tissue levels of malondialdehyde (P < 0.001), tumor necrosis factor-alpha (P < 0.001), interleukin (IL)-1beta (P < 0.001), and IL-6 (P < 0.001) and of serum levels of transaminase (P < 0.001) and lipopolysaccharides (P < 0.001) vs. sham-operated rats. I/R also induced a decrease in Bacterioides, Bifidobacterium, and Lactobacillus spps (P < 0.01, P < 0.001, and P < 0.001, respectively) and an increase in Enterococcus and Enterobacteriaceae (P < 0.01 and P < 0.001, respectively) on intestinal mucosa. The severity of liver and gut microbiota alterations induced by I/R was even greater in rats with liver inflammation and steatosis, i.e., MCD-fed animals. LP-F19 supplementation significantly reduced the harmful effects of I/R on the liver and on gut microbiota in both groups of rats, although the effect was slightly less in MCD-fed animals. In conclusion, LP-F19 supplementation, by restoring gut microbiota, attenuated I/R-related liver injury, particularly in the absence of steatosis.

CD133 and CD44 Cell surface markers do not identify cancer stem cells in primary human gastric tumors

Abstract  In the central nervous system glial‐derived S100B protein has been associated with inflammation via nitric oxide (NO) production. As the role of enteroglial cells in inflammatory bowel disease has been poorly investigated in humans, we evaluated the association of S100B and NO production in ulcerative colitis (UC). S100B mRNA and protein expression, inducible NO synthase (iNOS) expression, and NO production were evaluated in rectal biopsies from 30 controls and 35 UC patients. To verify the correlation between S100B and NO production, biopsies were exposed to S100B, in the presence or absence of specific receptor for advanced glycation end‐products (RAGE) blocking antibody, to measure iNOS expression and nitrite production. S100B and iNOS expression were evaluated after incubation of biopsies with lipopolysaccharides (LPS) + interferon‐gamma (IFN‐γ) in the presence of anti‐RAGE or anti‐S100B antibodies or budesonide. S100B mRNA and protein expression, iNOS expression and NO production were significantly higher in the rectal mucosa of patients compared to that of controls. Exogenous S100B induced a significant increase in both iNOS expression and NO production in controls and UC patients; this increase was inhibited by specific anti‐RAGE blocking antibody. Incubation with LPS + IFN‐γ induced a significant increase in S100B mRNA and protein expression, together with increased iNOS expression and NO production. LPS + IFN‐γ‐induced S100B up‐regulation was not affected by budesonide, while iNOS expression and NO production were significantly inhibited by both specific anti‐RAGE and anti‐S100B blocking antibodies. Enteroglial‐derived S100B up‐regulation in UC participates in NO production, involving RAGE in a steroid insensitive pathway.

Gastroduodenal lesions and Helicobacter pylori infection in dyspeptic patients with and without chronic renal failure

Emerging evidence suggests that tumors contain and are driven by a cellular component that displays stem cell properties, the so‐called cancer stem cells (CSCs). CSCs have been identified in several solid human cancers; however, there are no data about CSCs in primary human gastric cancer (GC). By using CD133 and CD44 cell surface markers we investigated whether primary human GCs contain a cell subset expressing stem‐like properties and whether this subpopulation has tumor‐initiating properties in xenograft transplantation experiments. We examined tissues from 44 patients who underwent gastrectomy for primary GC. The tumorigenicity of the cells separated by flow cytometry using CD133 and CD44 surface markers was tested by subcutaneous or intraperitoneum injection in NOD/SCID and nude mice. GCs included in the study were intestinal in 34 cases and diffuse in 10 cases. All samples contained surface marker‐positive cells: CD133+ mean percentage 10.6% and CD133+/CD44+ mean percentage 27.7%, irrespective of cancer phenotype or grade of differentiation. Purified CD133+ and CD133+/CD44+ cells, obtained in sufficient number only in 12 intestinal type GC cases, failed to reproduce cancer in two mice models. However, the unseparated cells produced glandular‐like structures in 70% of the mice inoculated. In conclusion, although CD133+ and CD133+/CD44+ were detectable in human primary GCs, they neither expressed stem‐like properties nor exhibited tumor‐initiating properties in xenograft transplantation experiments. J. Cell. Physiol. 227: 2686–2693, 2012.