Ikuya Miki

Levofloxacin based triple therapy as a second-line treatment after failure of helicobacter pylori eradication with standard triple therapy.

BACKGROUND Successful eradication of Helicobacter pylori infection after failure of standard triple therapy is difficult. The efficacy and safety of levofloxacin based triple therapy as a first-line therapy has-been studied. AIMS The aim was to evaluate the efficacy and tolerability of levofloxacin based therapy after a failed standard triple therapy. PATIENTS We conducted a prospective, uncontrolled study of a consecutive series of 33 patients who failed eradication with 1 week of lansoprazole-amoxicillin-clarithromycin triple therapy. METHODS The subjects were retreated with 1 week of LA-LVFX triple therapy (lansoprazole, 30 mg twice daily; amoxicillin, 1000 mg twice daily: levofloxacin, 200 mg twice daily). Cure of infection was defined as negative results from culture, histology and a urea breath test 4 to 8 weeks after the second-line therapy. RESULTS The eradication rate was 69.7% (23/33) by both intention-to-treat and per-protocol analyses (95% confidence interval=61-79%). Seven (21.2%) patients experienced mild side-effects, such as soft stools and taste disturbance. No patient stopped the medication on account of adverse effects. CONCLUSIONS Levofloxacin based triple therapy is an effective second-line treatment after a failed standard triple therapy.

Primary Levofloxacin Resistance and gyrA/B Mutations Among Helicobacter pylori in Japan

Background:  Recent years have witnessed a decrease in the rate of Helicobacter pylori eradication due to antimicrobial resistance, clarithromycin or metronidazole resistance in particular. As one of the alternatives to the standard regimens, levofloxacin‐containing therapy has been considered a promising regimen. Nevertheless, there is a little information concerning the prevalence of levofloxacin resistance and this resistance mechanism.

Impact of clarithromycin resistance and CYP2C19 genetic polymorphism on treatment efficacy of Helicobacter pylori infection with lansoprazole- or rabeprazole-based triple therapy in Japan.

Objective Helicobacter pylori treatment failure is thought to be due mainly to polymorphic cytochrome P450 2C19 (CYP2C19) genetic polymorphism, associated with proton pump inhibitor metabolism, and antimicrobial susceptibility. This report has ascertained which was more important, CYP2C19 polymorphism or antimicrobial susceptibility, when using 1-week lansoprazole-based or rabeprazole-based triple therapy in Japan. Design An open, randomized, parallel group study. Setting One hundred and forty-five subjects with H. pylori-positive gastritis or peptic ulcers were randomly assigned to receive 30 mg lansoprazole twice daily (LAC group), 10 mg rabeprazole twice daily (RAC20 group), or 20 mg rabeprazole twice daily (RAC40 group), with 1000 mg amoxicillin twice daily and 400 mg clarithromycin twice daily for 1 week. Antimicrobial resistance testing was performed by E-test. More than 4 weeks after completion of treatment, H. pylori status was assessed by 13C-urea breath test, histology, and culture. Results Cure rates expressed as intention-to-treat and per-protocol analyses, respectively, were 79.6 and 83.0% with LAC, 85.4 and 89.1% with RAC20, and 83.3 and 88.9% with RAC40. In the case of clarithromycin-sensitive strains, the cure rates were more than 97%, regardless of CYP2C19 polymorphism. However, treatment succeeded in only one out of 16 clarithromycin-resistant strains. Conclusions The key to successful eradication of H. pylori, using lansoprazole or rabeprazole with clarithromycin and amoxicillin, is clarithromycin susceptibility, not CYP2C19 polymorphism.

MDR1 genotype-related duodenal absorption rate of digoxin in healthy Japanese subjects.

AbstractPurpose. Recent clinical studies suggest the importance of the MDR1 genotype at position 3435 (C3435T) in terms of pharmacokinetics, but there is still no consensus in reports on the relationship between the genotype and plasma/serum concentration-time profiles of drugs after conventional oral administration. This study was performed to elucidate the effects of C3435T on the rate of duodenal absorption of digoxin in healthy Japanese subjects. Methods. Digoxin solution was sprinkled directly over the surface of the duodenum using an endoscope, and its absorption rate was evaluated by serial monitoring of the serum concentration and by analysis of its initial 15-min increasing phase. Results. The duodenal absorption rates of digoxin were 911 ± 91 ng/min and 506 ± 76 ng/min for C/C and T/T, respectively (±SE, p = 0.007). Conclusions. The C3435T mutation of the MDR1 gene is associated with suppression of duodenal absorption of digoxin.

Favorable genetic polymorphisms predictive of clinical outcome of chemoradiotherapy for stage II/III esophageal squamous cell carcinoma in Japanese.

Objectives:This study was performed to find the genetic factors predictive of clinical outcome to a 5-fluorouracil (5-FU)/cisplatin (CDDP)-based chemoradiotherapy (CRT) in Japanese patients with locally advanced esophageal squamous cell carcinoma (ESCC). Materials and Methods:Thirty-one patients with stage I-IVa ESCC (I/II/III/IVa = 7/7/14/3) were enrolled in this study. One course of treatment consisted of protracted venous infusions (PVIs) of 5-FU (400 mg/m2/24 hours for days 1–5 and 8–12), CDDP (40 mg/m2/3 hours on days 1 and 8) and radiation (2 Gy/d on days 1–5, 8–12, and 15–19), and a 2nd course was successively repeated after a 2-week interval. A total of 8 measurements of the plasma concentration of 5-FU were made using high performance liquid chromatography. Genetic polymorphisms examined herein included those in the genes coding thymidylate synthase (TS), glutathione S-transferase P1 (GSTP1), multidrug resistant transporter MDR1/P-glycoprotein, and intercellular adhesion molecule-1, and in a circadian rhythm-relating gene, CLOCK. Results:The CR rate depended on stage (P = 0.001), but the analysis was not sufficiently powered to reach a level of statistical significance for the 2-year survival rate (P = 0.061). For stage II/III patients, to have 2 or 3 polymorphisms of 3R/3R of 5′-TSER, a 6 bp of 3′-TSUTR, and GSTP1-Ile105Val resulted in an extensively longer survival (P = 0.020), although no difference was found between 2 groups, with respect to the plasma concentrations of 5-FU and clinicopathologic characteristics. Conclusions:The prognostic index may allow predictions of the clinical outcome of a 5-FU/CDDP-based CRT in stage II/III ESCC patients.

Inhibitory Effects of Glycyrrhetinic Acid on DNA Polymerase and Inflammatory Activities

We investigated the inhibitory effect of three glycyrrhizin derivatives, such as Glycyrrhizin (compound 1), dipotassium glycyrrhizate (compound 2) and glycyrrhetinic acid (compound 3), on the activity of mammalian pols. Among these derivatives, compound 3 was the strongest inhibitor of mammalian pols α, β, κ, and λ, which belong to the B, A, Y, and X families of pols, respectively, whereas compounds 1 and 2 showed moderate inhibition. Among the these derivatives tested, compound 3 displayed strongest suppression of the production of tumor necrosis factor-α (TNF-α) induced by lipopolysaccharide (LPS) in a cell-culture system using mouse macrophages RAW264.7 and peritoneal macrophages derived from mice. Moreover, compound 3 was found to inhibit the action of nuclear factor-κB (NF-κB) in engineered human embryonic kidney (HEK) 293 cells. In addition, compound 3 caused greater reduction of 12-O-tetradecanoylphorbol-13-acetate-(TPA-) induced acute inflammation in mouse ear than compounds 1 and 2. In conclusion, this study has identified compound 3, which is the aglycone of compounds 1 and 2, as a promising anti-inflammatory candidate based on mammalian pol inhibition.

Validation of the pepsinogen test method for gastric cancer screening using a follow-up study

BackgroundSerum pepsinogen (PG) measurement has been used for gastric cancer screening since the 1990s. However, there are no reports comparing the screening validity of the PG test method with that of conventional X-ray examination directly in the same population, using a follow-up study.MethodsFrom April 2000 to March 2001, 12 120 residents of Osaka Prefecture, who underwent opportunistic screening at a medical checkup organization in Osaka city (hereafter, “the organization”), were enrolled. They received both a barium meal examination and PG test simultaneously. All the participants were followed up for a 1-year period after the screening. For the participants advised to undergo endoscopic examination, the results of those who were examined at the organization were tallied. The other participants were checked using the Osaka Cancer Registry (hereafter, “the registry”).ResultsOf the 12 120 participants, 493 (4.1%) were positive with the PG method and 728 (6.0%) were positive with the X-ray method. Fifty-four (0.4%) were positive for both methods. Thirteen gastric cancer cases were diagnosed by successive esophagogastroduodenoscopies at the organization. Six additional gastric cancer cases were identified by record linkage with the registry. The sensitivity, specificity, and positive predictive values of the PG method with a PGI cutoff level of ≤30 ng/ml and PGI/PGII ratio of ≤2.0 were 36.8%, 96.0%, and 1.4%, respectively. These values for the direct X-ray examination were 68.4%, 94.1%, and 1.8%, respectively.ConclusionThe PG test method alone with a PGI cutoff level of ≤30 ng/ml and PGI/PGII ≤ 2.0 is not appropriate for gastric cancer screening.

Neonatal Fc receptor for IgG (FcRn) expressed in the gastric epithelium regulates bacterial infection in mice

Neonatal Fc receptors for immunoglobulin (Ig)G (FcRn) assume a central role in regulating host IgG levels and IgG transport across polarized epithelial barriers. We have attempted to elucidate the contribution of FcRn in controlling Helicobacter infection in the stomach. C57BL/6J wild-type or FcRn−/− mice were infected with Helicobacter heilmannii, and gastric lesions, bacterial load and the levels of antigen-specific IgG in serum and gastric juice were analyzed. The elevated levels of anti-H. heimannii IgG in gastric juice were observed exclusively in wild-type mice but not in FcRn−/− mice. In contrast, an increase in lymphoid follicles and bacterial loads along with deeper gastric epithelium invasion were noted in FcRn−/− mice. C57BL/6J wild-type or FcRn−/− mice were also infected with Helicobacter pylori SS1, and the results of the bacterial load in stomachs of these mice and the anti-H. pylori IgG levels in serum and gastric juice were similar to those from H. heilmannii infection. Our data suggest that FcRn can be functionally expressed in the stomach, which is involved in transcytosis of IgG, and prevent colonization by H. heilmannii and the associated pathological consequences of infection.

Circadian variability of pharmacokinetics of 5-fluorouracil and CLOCK T3111C genetic polymorphism in patients with esophageal carcinoma.

The variations of plasma concentrations of 5-fluorouracil (5-FU) were investigated in 30 esophageal cancer patients treated with repetitive protracted venous infusion (PVI) of 5-FU-based chemoradiotherapy, and in an attempt to find a new possible candidate that explains their variations, CLOCK T3111C genetic polymorphism was examined. The patients have received 2 courses of chemoradiotherapy consisting of 2 cycles of 5-day PVI of 5-FU (400 mg/m2/d) with cisplatin and concurrent radiation. The plasma concentrations of 5-FU were determined at 5 PM on day 3 and 5 AM on day 4 after the beginning of each 5-FU infusion. The CLOCK T3111C genotype was determined by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) and by direct sequencing. Plasma concentrations were measured in 239 samples. In the first course, the plasma concentrations of 5-FU at 5 AM were significantly lower than those at 5 PM in the first cycle, whereas a similar tendency was observed in the second cycle, although not significantly (Wilcoxon signed-rank test). The plasma concentrations of 5-FU at 5 PM and 5 AM in the second cycle were both significantly higher than those in the first cycle, and their coefficient of variation in the former was also significantly smaller than that in the latter. These phenomena in the first course were also observed in the second one. These results revealed the elevation of plasma drug concentration and its reduced circadian variation during repetitive PVI of 5-FU. In 5-FU-based chemotherapy, its administration schedule should be made in consideration of these phenomena. The CLOCK T3111C genotype did not have a significant impact on the variation of the plasma concentrations of 5-FU in this study population. Further studies are needed to clarify the mechanism of these phenomena and to identify an easy-to-assess marker of circadian rhythms for use in individualizing delivery of 5-FU.

VEGF G-1154A is Predictive of Severe Acute Toxicities during Chemoradiotherapy for Esophageal Squamous Cell Carcinoma in Japanese Patients

This study was conducted to evaluate the association between systemic exposure to 5-fluorouracil (5-FU) and genetic polymorphisms of vascular endothelial growth factor (VEGF) with clinical outcomes to a 5-FU/cisplatin-based chemoradiotherapy in Japanese patients with esophageal squamous cell carcinoma (ESCC). Forty-nine patients with ESCC (I/II/III/IVa = 11/9/17/7, with 5 postoperative recurrences) were enrolled into this study. One course of treatment consisted of protracted venous infusions of 5-FU (400 mg/m2/24 hr for day 1-5 and 8-12) and cisplatin (40 mg/m2/3 hr on day 1 and 8), and radiation (2 Gy/day on day 1-5, 8-12, and 15-19); a second course was repeated after a 2 week interval. A total of eight measurements of the plasma concentration of 5-FU were made per patient to evaluate its systemic exposure as area under the concentration time curve for 480 hours (AUC480h), and VEGF genotypes of T-1498C, G-1154A, C-634G, C-7T, C936T, and G1612A were evaluated. The mean value of AUC480h in the patients with a complete response was 58.7 ± 16.8 mg*h/L, which was higher than that in the others, 49.0 ± 10.9 mg*h/L (P = 0.029), whereas no such association was found for severe acute toxicities. VEGF genotype was not associated with the clinical response, whereas VEGF G-1154A resulted in severe acute leukopenia (P = 0.042) and severe acute cheilitis (P = 0.025). In conclusion, VEGF G-1154A was a predictor of severe acute toxicities during 5-FU/cisplatin-based chemoradiotherapy in Japanese ESCC patients, whereas the AUC480h value of 5-FU was predictive of the clinical response.