Adaptation of pancreatic cancer cells to nutrient deprivation is reversible and requires glutamine synthetase stabilization by mTORC1.

Pancreatic ductal adenocarcinoma (PDA) is a lethal, therapy-resistant cancer that thrives in a highly desmoplastic, nutrient-deprived microenvironment. Several studies investigated the effects of depriving PDA of either glucose or glutamine alone. However, the consequences on PDA growth and metabolism of limiting both preferred nutrients have remained largely unknown. Here, we report the selection for clonal human PDA cells that survive and adapt to limiting levels of both glucose and glutamine. We find that adapted clones exhibit increased growth in vitro and enhanced tumor-forming capacity in vivo. Mechanistically, adapted clones share common transcriptional and metabolic programs, including amino acid use for de novo glutamine and nucleotide synthesis. They also display enhanced mTORC1 activity that prevents the proteasomal degradation of glutamine synthetase (GS), the rate-limiting enzyme for glutamine synthesis. This phenotype is notably reversible, with PDA cells acquiring alterations in open chromatin upon adaptation. Silencing of GS suppresses the enhanced growth of adapted cells and mitigates tumor growth. These findings identify nongenetic adaptations to nutrient deprivation in PDA and highlight GS as a dependency that could be targeted therapeutically in pancreatic cancer patients.

Small-molecule RORγt antagonists inhibit T helper 17 cell transcriptional network by divergent mechanisms.

We identified three retinoid-related orphan receptor gamma t (RORγt)-specific inhibitors that suppress T helper 17 (Th17) cell responses, including Th17-cell-mediated autoimmune disease. We systemically characterized RORγt binding in the presence and absence of drugs with corresponding whole-genome transcriptome sequencing. RORγt acts as a direct activator of Th17 cell signature genes and a direct repressor of signature genes from other T cell lineages; its strongest transcriptional effects are on cis-regulatory sites containing the RORα binding motif. RORγt is central in a densely interconnected regulatory network that shapes the balance of T cell differentiation. Here, the three inhibitors modulated the RORγt-dependent transcriptional network to varying extents and through distinct mechanisms. Whereas one inhibitor displaced RORγt from its target loci, the other two inhibitors affected transcription predominantly without removing DNA binding. Our work illustrates the power of a system-scale analysis of transcriptional regulation to characterize potential therapeutic compounds that inhibit pathogenic Th17 cells and suppress autoimmunity.

Tailored susceptibility-guided therapy via gastric juice PCR for the first-line H. pylori eradication, a randomized controlled trial.

BACKGROUND/PURPOSE: Clarithromycin-based standard triple therapy is still commonly adopted by 81.4% of physicians in real-world practice but yields low eradication rates. Therefore, we conducted this study to compare the efficacy of gastric juice-guided therapy for first-line eradication with the standard triple therapy, in order to provide an alternative to real-world practice. METHODS: A total of 182 treatment-naïve Hp-infected patients were included and randomly allocated to either susceptibility-guided therapy (SGT) with gastric juice PCR or Clarithromycin-based standard triple therapy (STT) for 7 days. RESULTS: The intention-to-treat eradication rates were 89% (81/91) in SGT and 75.8% in STT (p < 0.031). The per-protocol eradication rates were 91.0% (81/89) in SGT and 79.3% (69/87) in STT (p < 0.034). Among the subgroups of different antibiotic resistance, patients with SGT demonstrated superior eradication rates (91.7% vs 45.5%, p < 0.027) in the subgroup of both clarithromycin resistance and levofloxacin resistance. CONCLUSION: This prospective randomized controlled trial demonstrated the reliable efficacy of susceptibility-guided therapy via gastric juice PCR for the first-line Hp eradication. In Asia-Pacific area, where standard triple therapy is still adopted by the majority of the physicians, it is a recommended alternative to overcome the increasing antibiotic resistance.

Ablation of insulin receptor substrates 1 and 2 suppresses Kras-driven lung tumorigenesis.

Non-small-cell lung cancer (NSCLC) is a leading cause of cancer death worldwide, with 25% of cases harboring oncogenic Kirsten rat sarcoma (KRAS). Although KRAS direct binding to and activation of PI3K is required for KRAS-driven lung tumorigenesis, the contribution of insulin receptor (IR) and insulin-like growth factor 1 receptor (IGF1R) in the context of mutant KRAS remains controversial. Here, we provide genetic evidence that lung-specific dual ablation of insulin receptor substrates 1/2 (Irs1/Irs2), which mediate insulin and IGF1 signaling, strongly suppresses tumor initiation and dramatically extends the survival of a mouse model of lung cancer with Kras activation and p53 loss. Mice with Irs1/Irs2 loss eventually succumb to tumor burden, with tumor cells displaying suppressed Akt activation and strikingly diminished intracellular levels of essential amino acids. Acute loss of IRS1/IRS2 or inhibition of IR/IGF1R in KRAS-mutant human NSCLC cells decreases the uptake and lowers the intracellular levels of amino acids, while enhancing basal autophagy and sensitivity to autophagy and proteasome inhibitors. These findings demonstrate that insulin/IGF1 signaling is required for KRAS-mutant lung cancer initiation, and identify decreased amino acid levels as a metabolic vulnerability in tumor cells with IR/IGF1R inhibition. Consequently, combinatorial targeting of IR/IGF1R with autophagy or proteasome inhibitors may represent an effective therapeutic strategy in KRAS-mutant NSCLC.

Coherence between Decomposed Components of Wrist and Finger PPG Signals by Imputing Missing Features and Resolving Ambiguous Features.

BACKGROUND: Feature extraction from photoplethysmography (PPG) signals is an essential step to analyze vascular and hemodynamic information. Different morphologies of PPG waveforms from different measurement sites appear. Various phenomena of missing or ambiguous features exist, which limit subsequent signal processing. METHODS: The reasons that cause missing or ambiguous features of finger and wrist PPG pulses are analyzed based on the concept of component waves from pulse decomposition. Then, a systematic approach for missing-feature imputation and ambiguous-feature resolution is proposed. RESULTS: From the experimental results, with the imputation and ambiguity resolution technique, features from 35,036 (98.7%) of 35,502 finger PPG cycles and 36307 (99.1%) of 36,652 wrist PPG cycles can be successfully identified. The extracted features became more stable and the standard deviations of their distributions were reduced. Furthermore, significant correlations up to 0.92 were shown between the finger and wrist PPG waveforms regarding the positions and widths of the third to fifth component waves. CONCLUSION: The proposed missing-feature imputation and ambiguous-feature resolution solve the problems encountered during PPG feature extraction and expand the feature availability for further processing. More intrinsic properties of finger and wrist PPG are revealed. The coherence between the finger and wrist PPG waveforms enhances the applicability of the wrist PPG.

Medication interventions for African-American adults: Practice-based evidence from two nurse-led clinics.

OBJECTIVE: This study was conducted to describe and examine the impact of medication intervention practices among African-American clients in two nurse-led community nursing centers (CNCs). METHODS: This study used a retrospective-descriptive design. Omaha System data from visits of 196 African-American adults living with chronic disease and having two or more CNC visits in which medication regimen was an identified problem and the main reason for the visit was analyzed. RESULTS: The sample had a mean age of 53.1 (6.67) and was primarily women (82%), uninsured, and with high school or less education. A total of 9,259 Medication regimen interventions were documented and implemented during 1,146 client CNC visits. A paired samples t test revealed statistically significant improvements in Knowledge (t = 2.434, p < .01). Behavior (t = 0.077, p = .94) and Status (t = 1.489, p = .14) remained unchanged, although the ratings trended toward improvement for each. CONCLUSION: This study provides evidence that the nursing center model of care does improve the knowledge of medications among African-American clients. The study also demonstrated the Omaha System's utility to evaluate the impact of nursing interventions in community settings.

Using the Omaha System to Evaluate the Integration of Behavioral Health Services into Nurse-Led Primary Health Care.

Integrating behavioral health services into nurse-led primary care at one location ensures that individuals receive a comprehensive array of preventive and restorative services, based on their varying needs. A formative program evaluation of a federally funded behavioral health integration (BHI) project in a small nurse-led clinic used the Omaha System taxonomy to explore the changes in the documented practice of providers due to the BHI implementation. The evaluation provided evidence of the benefits of a collaborative care model to urban low-income, underserved, adults who were predominantly African American/Blacks.

Gastric juice-based PCR assay: An alternative testing method to aid in the management of previously treated Helicobacter pylori infection.

BACKGROUND: Culture of Helicobacter pylori with previous eradication failure has been emphasized in clinical guidelines. The current unmet need to manage previously treated H pylori is one tool with diagnostic accuracy and ability for antibiotics susceptibility. Gastric juice PCR can provide diagnosis and antibiotics susceptibility; however, whether treatment failure affects its accuracy remains uninvestigated. Our study aimed to investigate diagnostic accuracy and antibiotics susceptibility of juice PCR in previously treated H pylori and to compare with the current standard of culture. METHODS: We categorized all 547 patients into treatment-naïve, post-1st treatment, post-2nd treatment, and post-3rd treatment. Helicobacter pylori infection was confirmed using gold standards. Sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic (ROC) curve and area under ROC curve (AUC) of juice PCR and culture were calculated. Intra-gastric H pylori density was evaluated. Lastly, the antibiotics susceptibility results of gastric juice and culture were compared. RESULTS: Our findings demonstrated AUC was higher in juice PCR than culture in all patients (96.7% vs 91.3%, P < 0.0001). The superiority of juice PCR was statistically significant in previously treated patients (P < 0.0001) but not in treatment-naïve patients (P = 0.13). Antral H pylori density was less marked in previously treated patients (P = 0.014). The comparisons of PCR-RFLP and E-test for Clarithromycin resistance showed reliable AUC = 89.8%. CONCLUSION: Compared with the current standard of culture, the gastric juice PCR contains the strengths of performing the antibiotics susceptibility and overcomes the shortcomings of low accuracy. Consequently, gastric juice PCR suits the unmet need to manage previously treated H pylori.

Accumulation of methylglyoxal and d-lactate in Pb-induced nephrotoxicity in rats.

Lead (Pb) is an environmental pollutant associated with several diseases, such as nephrotoxicity. Methylglyoxal (MG) is a reactive dicarbonyl compound formed during glycolysis and reported to increase in kidney damage. Metformin is used as an MG scavenger in the clinic. In this study, we investigated the mechanism of Pb-induced renal injury and the effect of metformin on Pb-induced nephrotoxicity. Eighteen Wistar rats were randomly divided into three groups: control, Pb, and Pb + metformin groups. Pb (250 ppm) was administered in drinking water, and 50 mg/kg of metformin was co-administered orally. After 28 days, the levels of MG and its metabolite d-lactate in urine, serum and renal tissues were examined. The elevation of renal MG (56.86 ± 17.47 vs 36.40 ± 5.69, p < 0.01) and urinary d-lactate (0.68 ± 0.28 vs 0.32 ± 0.13, p < 0.01) was observed in Pb-exposed rats compared with those in control rats. After co-treatment with metformin, these phenomena were attenuated. In the present study, it was demonstrated for the first time that urinary d-lactate might serve as the candidate marker for Pb-induced nephrotoxicity in the clinic, and metformin might be a new therapeutic candidate for Pb poisoning.

Roles of nucleic acid substrates and cofactors in the vhs protein activity of pseudorabies virus.

Pseudorabies virus (PrV) belongs to the α-herpesvirinae of which human simplex virus (HSV) is the prototype virus. One of the hallmarks of HSV infection is shutoff of protein synthesis that is mediated by various viral proteins including vhs (virion host shutoff), which is encoded by the UL41 gene. However, the function of PrV vhs is poorly understood. Due to the low sequence similarity (39.3%) between the HSV and PrV UL41 proteins, vhs might not share the same biochemistry characteristics. The purpose of this study was to characterize the nuclease activity of the PrV vhs protein with respect to substrate specificity, its requirements in terms of cofactors, and the protein regions, as well as key amino acids, which contribute to vhs activity. Our results indicated that, similar to HSV vhs, PrV vhs is able to degrade ssRNA and mRNA. However, PrV vhs also targeted rRNA for degradation, which is novel compared to the HSV-1 vhs. Activity assays indicated that Mg(2+) alone enhances RNA degradation mediated by PrV vhs, while K(+) and ATP are not sufficient to induce activity. Finally, we demonstrated that each of the four highly conserved functional boxes of PrV vhs contributes to RNA degradation and that, in particular, residues 152, 169, 171, 172, 173 343, 345, 352 and 356, which are conserved among α-herpesviruses, are key amino acids needed for PrV vhs ribonuclease activity.

TNFR2 activates MLCK-dependent tight junction dysregulation to cause apoptosis-mediated barrier loss and experimental colitis.

BACKGROUND & AIMS: Tight junction dysregulation and epithelial damage contribute to barrier loss in patients with inflammatory bowel disease. However, the mechanisms that regulate these processes and their relative contributions to disease pathogenesis are not completely understood. We investigated these processes using colitis models in mice. METHODS: We induced colitis by adoptive transfer of CD4(+)CD45RB(hi) cells or administration of dextran sulfate sodium to mice, including those deficient in tumor necrosis factor receptor (TNFR) 1, TNFR2, or the long isoform of myosin light chain kinase (MLCK). Intestinal tissues and isolated epithelial cells were analyzed by immunoblot, immunofluorescence, enzyme-linked immunosorbent assay, and real-time polymerase chain reaction assays. RESULTS: Induction of immune-mediated colitis by CD4(+)CD45RB(hi) adoptive transfer increased intestinal permeability, epithelial expression of claudin-2, the long isoform of MLCK, and TNFR2 (but not TNFR1) and phosphorylation of the myosin II light chain. Long MLCK upregulation, myosin II light chain phosphorylation, barrier loss, and weight loss were attenuated in TNFR2(-/-) , but not TNFR1(-/-) , recipients of wild-type CD4(+)CD45RB(hi) cells. Similarly, long MLCK(-/-) mice had limited increases in myosin II light chain phosphorylation, claudin-2 expression, and intestinal permeability and delayed onset of adoptive transfer-induced colitis. However, coincident with onset of epithelial apoptosis, long MLCK(-/-) mice ultimately developed colitis. This indicates that disease progresses via apoptosis in the absence of MLCK-dependent tight junction regulation. In support of this conclusion, long MLCK(-/-) mice were not protected from epithelial apoptosis-mediated, damage-dependent dextran sulfate sodium colitis. CONCLUSIONS: In immune-mediated inflammatory bowel disease models, TNFR2 signaling increases long MLCK expression, resulting in tight junction dysregulation, barrier loss, and induction of colitis. At advanced stages, colitis progresses by apoptosis and mucosal damage that result in tight junction- and MLCK-independent barrier loss. Therefore, barrier loss in immune-mediated colitis occurs via two temporally and morphologically distinct mechanisms. Differential targeting of these mechanisms can lead to improved inflammatory bowel disease therapies.

Providing and funding breast health services in urban nurse-managed health centers.

Nurse-managed health centers (NMHCs) are an innovative health care delivery model that serves as an important point of health care access for populations at risk for disparities in health outcomes. This article describes the process and outcomes of clinical breast health services in two NMHCs located in a large Midwestern city. Findings indicate that client's knowledge about breast health was increased after they received breast health services from NMHC nurses. Significant positive changes in behavior related to the early detection of breast cancer were found in the study. NMHCs, identified for expansion in the Patient Protection and Affordable Care Act, offer a unique health care services delivery model that promotes access to care and early identification of breast cancer in very low-income and uninsured women.

Proteome analysis of altered proteins in streptozotocin-induced diabetic rat kidney using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry method.

To find new molecular markers for early diagnosis of diabetic nephropathy, we applied fluorogenic derivatization-liquid chromatography-tandem mass spectrometry to identify the differentially expressed proteins in the kidney of control and streptozotocin-induced diabetic rats. The Sprague-Dawley rats were injected with the sodium citrate buffer or streptozotocin and then killed after 1, 4, 12 and 24 weeks. The results showed that seven proteins were significantly changed after 1 week of injection. Only one protein had significantly changed after 4 weeks of injection. However, after 12 weeks of injection, the number of altered proteins rose to 10. After 24 weeks of injection, 18 proteins had altered significantly. Five common proteins were significantly altered at week 12 and 24 after injection, respectively. Importantly, these proteins appeared prior to microalbuminuria and may serve as new biomarkers that are able to improve early detection of and new drug development for diabetic-related nephropathy.

SUMOylation attenuates c-Maf-dependent IL-4 expression.

The function of transcription factors can be critically regulated by SUMOylation. c-Maf, the cellular counterpart of v-maf oncogene, is a potent transactivator of the IL-4 gene in Th2 cells. We found in a yeast two-hybrid screen that c-Maf can interact with Ubc9 and PIAS1, two key enzymes of the SUMOylation pathway. In this study, we report that c-Maf co-localized with these two SUMO (small ubiquitin-like modifier) ligases in the nucleus and that c-Maf can be SUMOylated in vitro and also in primary Th2 cells. We also demonstrated that lysine-33 is the dominant, if not the only, SUMO acceptor site of c-Maf. SUMOylation of c-Maf attenuated its transcriptional activity. Reciprocally, a SUMOylation resistant c-Maf was more potent than WT-c-Maf in driving IL-4 production in c-Maf-deficient Th2 cells. Furthermore, we showed that ablation of the SUMO site did not alter the subcellular localization or the stability of c-Maf protein but instead enhanced its recruitment to the Il4-promoter. We conclude that SUMOylation at lysine-33 is a functionally critical post-translational modification event of c-Maf in Th cells.

Methylglyoxal Levels in Human Colorectal Precancer and Cancer: Analysis of Tumor and Peritumor Tissue.

Colorectal cancer (CRC) is one of the most common cancers worldwide and its incidence is increasing; therefore, an understanding of its oncogenic mechanisms is critical for improving its treatment and management. Methylglyoxal (MGO) has a highly reactive aldehyde group and has been suggested to play a role in oncogenesis. However, no standardized data are currently available on MGO levels in colorectal precancerous and cancerous lesions. We collected 40 matched colorectal tumor and peritumor tissues from patients with low-grade dysplasia (LGD), high-grade dysplasia (HGD), and invasive cancer (IC). MGO levels increased between LGD, HGD, and IC tumor tissues (215.25 ± 39.69, 267.45 ± 100.61, and 587.36 ± 123.19 µg/g protein, respectively; p = 0.014). The MGO levels in peritumor tissue increased and were significantly higher than MGO levels in tumor tissue (197.99 ± 49.40, 738.09 ± 247.87, 933.41 ± 164.83 µg/g protein, respectively; p = 0.002). Tumor tissue MGO levels did not correlate with age, sex, underlying disease, or smoking status. These results suggest that MGO levels fluctuate in progression of CRC and warrants further research into its underlying mechanisms and function in tumor biology.

Mesoporous Properties of Bioactive Glass Synthesized by Spray Pyrolysis with Various Polyethylene Glycol and Acid Additions.

Mesoporous bioactive glass (MBG) has a high specific surface area, promoting the reaction area, thereby improving the bioactivity; thus, MBG is currently gaining popularity in the biomaterial field. Spray pyrolysis (SP) is a one-pot process that has the advantages of shorter process time and better particle bioactivity, therefore, MBG was prepared by SP process with various polyethylene glycol (PEG, molecular weight ranged from 2000-12,000) and acid (HCl and CH3COOH) additions. In vitro bioactivity and mesoporous properties of the so-obtained MBG were investigated. The experimental results showed that all the MBG exhibited amorphous and mesoporous structure. Increasing the molecular weight of PEG can improve the mesoporous structure and bioactivity of MBG. Whereas optimized MBG was prepared with suitable concentration of PEG and CH3COOH. In the present work, MBG synthesized via spray pyrolysis by adding 5 g of PEG with a molecular weight of 12,000 and 50 mL of CH3COOH exhibited the best in vitro bioactivity and mesoporous structure.

Utilizing methylglyoxal and D-lactate in urine to evaluate saikosaponin C treatment in mice with accelerated nephrotoxic serum nephritis.

The relationship between methylglyoxal (MGO) and D-lactate during saikosaponin C (SSC) treatment of mice with accelerated nephrotoxic serum (NTS) nephritis was investigated. NTS nephritis was induced by administration of anti-basement membrane antibodies to C57BL/6 mice and three dosages of SSC were administered for 14 days. Proteinuria, blood urea nitrogen, serum creatinine, renal histology, urinary MGO and d-lactate changes were examined. Compared to the NTS control group, the middle dosage (10 mg/kg/day) of SSC significantly alleviated the development of nephritis based on urine protein measurements (34.40 ± 6.85 vs. 17.33 ± 4.79 mg/day, p<0.05). Pathological observation of the glomerular basement membrane (GBM) revealed monocyte infiltration, hypertrophy, and crescents were alleviated, and injury scoring also showed improved efficacy for the middle dose of SSC during nephritis (7.92 ± 1.37 vs. 3.50 ± 1.14, p<0.05). Moreover, the significant decreases in urinary levels of MGO (24.71 ± 3.46 vs. 16.72 ± 2.36 µg/mg, p<0.05) and D-lactate (0.31 ± 0.04 vs. 0.23 ± 0.02 µmol/mg, p<0.05) were consistent with the biochemical and pathological examinations. This study demonstrates that MGO and D-lactate may reflect the extent of damage and the efficacy of SSC in NTS nephritis; further studies are required to enable clinical application.

Methylglyoxal and D-lactate in cisplatin-induced acute kidney injury: Investigation of the potential mechanism via fluorogenic derivatization liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS) proteomic analysis.

Nephrotoxicity severely limits the chemotherapeutic efficacy of cisplatin (CDDP). Oxidative stress is associated with CDDP-induced acute kidney injury (AKI). Methylglyoxal (MG) forms advanced glycation end products that elevate oxidative stress. We aimed to explore the role of MG and its metabolite D-lactate and identify the proteins involved in CDDP-induced AKI. Six-week-old female BALB/c mice were intraperitoneally administered CDDP (5 mg/kg/day) for 3 or 5 days. Blood urea nitrogen (42.6 ± 7.4 vs. 18.3 ± 2.5; p < 0.05) and urinary N-acetyl-ß-D-glucosaminide (NAG; 4.89 ± 0.61 vs. 2.43 ± 0.31 U/L; p < 0.05) were significantly elevated in the CDDP 5-day group compared to control mice. Histological analysis confirmed AKI was successfully induced. Confocal microscopy revealed TNF-α was significantly increased in the CDDP 5-day group. Fluorogenic derivatized liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS) showed the kidney MG (36.25 ± 1.68 vs. 18.95 ± 2.24 mg/g protein, p < 0.05) and D-lactate (1.78 ± 0.29 vs. 1.12 ± 0.06 mol/g protein, p < 0.05) contents were significantly higher in the CDDP 5-day group than control group. FD-LC-MS/MS proteomics identified 33 and nine altered peaks in the CDDP 3-day group and CDDP 5-day group (vs. control group); of the 35 proteins identified using the MOSCOT database, 11 were antioxidant-related. Western blotting confirmed that superoxide dismutase 1 (SOD-1) and parkinson disease protein 7 (DJ-1) are upregulated and may participate with MG in CDDP-induced AKI. This study demonstrates TNF-α, MG, SOD-1 and DJ-1 play crucial roles in CDDP-induced AKI.

Inactivation of paracellular cation-selective claudin-2 channels attenuates immune-mediated experimental colitis in mice.

The tight junction protein claudin-2 is upregulated in disease. Although many studies have linked intestinal barrier loss to local and systemic disease, these have relied on macromolecular probes. In vitro analyses show, however, that these probes cannot be accommodated by size- and charge-selective claudin-2 channels. We sought to define the impact of claudin-2 channels on disease. Transgenic claudin-2 overexpression or IL-13-induced claudin-2 upregulation increased intestinal small cation permeability in vivo. IL-13 did not, however, affect permeability in claudin-2-knockout mice. Claudin-2 is therefore necessary and sufficient to effect size- and charge-selective permeability increases in vivo. In chronic disease, T cell transfer colitis severity was augmented or diminished in claudin-2-transgenic or -knockout mice, respectively. We translated the in vitro observation that casein kinase-2 (CK2) inhibition blocks claudin-2 channel function to prevent acute, IL-13-induced, claudin-2-mediated permeability increases in vivo. In chronic immune-mediated colitis, CK2 inhibition attenuated progression in claudin-2-sufficient, but not claudin-2-knockout, mice, i.e., the effect was claudin-2 dependent. Paracellular flux mediated by claudin-2 channels can therefore promote immune-mediated colitis progression. Although the mechanisms by which claudin-2 channels intensify disease remain to be defined, these data suggest that claudin-2 may be an accessible target in immune-mediated disorders, including inflammatory bowel disease.

Efficacy of levofloxacin-based rescue therapy for Helicobacter pylori infection after standard triple therapy: a randomized controlled trial.

OBJECTIVES: This prospective study was designed to determine the efficacy of a levofloxacin-based rescue therapy for Helicobacter pylori infection after failure of standard triple therapies. We also surveyed the predictors of this rescue therapy. PATIENTS AND METHODS: From June 2005 to March 2007, 1036 patients infected with H. pylori received standard triple regimens (proton pump inhibitor, clarithromycin and amoxicillin). H. pylori eradication was achieved in 855 (82.5%) subjects. One hundred and sixty-six eradication-failure patients were enrolled and randomly assigned to receive a 7 day eradication therapy with esomeprazole, bismuth subcitrate, tetracycline and metronidazole (EBTM) or esomeprazole, amoxicillin and levofloxacin (EAL). Follow-up endoscopy was done 16 weeks later to assess the treatment response. Patients' response, CYP2C19 genotypes and antibiotic resistances were also examined. RESULTS: Intention-to-treat analysis revealed that both groups showed similar eradication rates [EBTM 63.9%; 95% confidence interval (CI): 53.6-74.2 and EAL 69.9%; 95% CI: 60.1-79.7] (P = 0.89). Per-protocol results were EBTM = 84.1% (95% CI: 75.1-93.1) and EAL = 75.3% (95% CI: 65.8-84.8) (P = 0.82). Both regimens had similar compliance (P = 0.32), but the EBTM group had more adverse events (P = 0.27). Logistic regression analysis showed that poor compliance, CYP2C19 homozygous extensive metabolizer genotype and levofloxacin resistance were important predictors for eradication failure. CONCLUSIONS: The EAL regimen can achieve an efficacy similar to that of the standard EBTM therapy. It may be very useful in countries where bismuth salts are not available. Compliance, CYP2C19 genotype and resistances to antibiotics may influence the outcome of levofloxacin-based rescue therapy. It seems advisable to reserve levofloxacin for rescue treatment to avoid an increase in the resistance phenomenon.