Reprogramming Antagonizes the Oncogenicity of HOXA13-Long Noncoding RNA HOTTIP Axis in Gastric Cancer Cells.

Reprogramming of cancer cells into induced pluripotent stem cells (iPSCs) is a compelling idea for inhibiting oncogenesis, especially through modulation of homeobox proteins in this reprogramming process. We examined the role of various long noncoding RNAs (lncRNAs)-homeobox protein HOXA13 axis on the switching of the oncogenic function of bone morphogenetic protein 7 (BMP7), which is significantly lost in the gastric cancer cell derived iPS-like cells (iPSLCs). BMP7 promoter activation occurred through the corecruitment of HOXA13, mixed-lineage leukemia 1 lysine N-methyltransferase, WD repeat-containing protein 5, and lncRNA HoxA transcript at the distal tip (HOTTIP) to commit the epigenetic changes to the trimethylation of lysine 4 on histone H3 in cancer cells. By contrast, HOXA13 inhibited BMP7 expression in iPSLCs via the corecruitment of HOXA13, enhancer of zeste homolog 2, Jumonji and AT rich interactive domain 2, and lncRNA HoxA transcript antisense RNA (HOTAIR) to various cis-element of the BMP7 promoter. Knockdown experiments demonstrated that HOTTIP contributed positively, but HOTAIR regulated negatively to HOXA13-mediated BMP7 expression in cancer cells and iPSLCs, respectively. These findings indicate that the recruitment of HOXA13-HOTTIP and HOXA13-HOTAIR to different sites in the BMP7 promoter is crucial for the oncogenic fate of human gastric cells. Reprogramming with octamer-binding protein 4 and Jun dimerization protein 2 can inhibit tumorigenesis by switching off BMP7. Stem Cells 2017;35:2115-2128.

Levels of malondialdehyde in the gastric juice: Its association with Helicobacter pylori infection and stomach diseases.

BACKGROUND: Helicobacter pylori (H. pylori) infection causes elevation of lipid peroxidation product malondialdehyde (MDA) and this association may be due to the bacterium causing reactive oxygen species-mediated damage to DNA in the gastric epithelium. The aim of this study was to investigate the gastric juice MDA levels in relation to H. pylori infection and associated gastric diseases. METHODS: Gastric juice samples were obtained from 117 patients undergoing endoscopy, and gastric juice MDA levels were determined by high-performance liquid chromatography (HPLC) system. We compared the MDA levels between patients with and without H. pylori infection and assessed the differences of MDA levels between chronic gastritis, gastric intestinal metaplasia, and gastric cancer postsurgical resection. RESULTS: Malondialdehyde levels in gastric juice were significantly higher in chronic gastritis patients with H. pylori infection than in those without H. pylori infection (P < .0001). In patients without H. pylori infection, patients with gastric intestinal metaplasia and gastric cancer postsurgical resection had significantly higher gastric juice MDA level than patients with chronic gastritis. As a whole, patients with gastric intestinal metaplasia and gastric cancer postsurgical resection also had significantly higher MDA levels in gastric juice as compared to patients with chronic gastritis (P < .01). However, the difference of gastric juice MDA levels between gastric intestinal metaplasia and gastric cancer postsurgical resection was not significant. CONCLUSION: Malondialdehyde in gastric juice could be used as a potential diagnostic biomarker for H. pylori infection and associated gastric diseases. The gastric juice MDA levels increased proportionally with the severity of gastric diseases.

Exploring the expression bar code of SAA variants for gastric cancer detection.

We reported an integrated platform to explore serum protein variant pattern in cancer and its utility as a new class of biomarker panel for diagnosis. On the model study of serum amyloid A (SAA), we employed nanoprobe-based affinity mass spectrometry for enrichment, identification and quantitation of SAA variants from serum of 105 gastric cancer patients in comparison with 54 gastritis patients, 54 controls, and 120 patients from other cancer. The result revealed surprisingly heterogeneous and most comprehensive SAA bar code to date, which comprises 24 SAA variants including SAA1- and SAA2-encoded products, polymorphic isoforms, N-terminal-truncated forms, and three novel SAA oxidized isotypes, in which the variant-specific peptide sequence were also confirmed by LC-MS/MS. A diagnostic model was developed for dimension reduction and computational classification of the 24 SAA-variant bar code, providing good discrimination (AUC = 0.85 ± 3.2E-3) for differentiating gastric cancer group from gastritis and normal groups (sensitivity, 0.76; specificity, 0.81) and was validated with external validation cohort (sensitivity, 0.71; specificity, 0.74). Our platform not only shed light on the occurrence and modification extent of under-represented serum protein variants in cancer, but also suggested a new concept of diagnostic platform by serum protein variant profile.

Positive Feedback Loop of OCT4 and c-JUN Expedites Cancer Stemness in Liver Cancer.

The network of stemness genes and oncogenes in human patient-specific reprogrammed cancer stem cells (CSCs) remains elusive, especially in liver cancer. HepG2-derived induced pluripotent stem cell-like cells (HepG2-iPS-like cells) were generated by introducing Yamanaka factors and the knockdown vector shTP53. They exhibited features of stemness and a higher tumorigenesis after xenograft transplantation compared with HepG2 cells. The cancerous mass of severe combined immunodeficiency (SCID) mice derived from one colony was dissected and cultured to establish reprogrammed HepG2-derived CSC-like cells (designated rG2-DC-1C). A single colony exhibited 42% occurrence of tumors with higher proliferation capacities. rG2-DC-1C showed continuous expression of the OCT4 stemness gene and of representative tumor markers, potentiated chemoresistance characteristics, and invasion activities. The sphere-colony formation ability and the invasion activity of rG2-DC-1C were also higher than those of HepG2 cells. Moreover, the expression of the OCT4 gene and the c-JUN oncogene, but not of c-MYC, was significantly elevated in rG2-DC-1C, whereas no c-JUN expression was observed in HepG2 cells. The positive-feedback regulation via OCT4-mediated transactivation of the c-JUN promoter and the c-JUN-mediated transactivation of the OCT4 promoter were crucial for promoting cancer development and maintaining cancer stemness in rG2-DC-1C. Increased expression of OCT4 and c-JUN was detected in the early stage of human liver cancer. Therefore, the positive feedback regulation of OCT4 and c-JUN, resulting in the continuous expression of oncogenes such as c-JUN, seems to play a critical role in the determination of the cell fate decision from iPS cells to CSCs in liver cancer. Stem Cells 2016;34:2613-2624.

Suppression of IL-8-Src signalling axis by 17ß-estradiol inhibits human mesenchymal stem cells-mediated gastric cancer invasion.

Epidemiologic data show the incidence of gastric cancer in men is twofold higher than in women worldwide. Oestrogen is reported to have the capacity against gastric cancer development. Endogenous oestrogen reduces gastric cancer incidence in women. Cancer patients treated with oestrogens have a lower subsequent risk of gastric cancer. Accumulating studies report that bone marrow mesenchymal stem cells (BMMSCs) might contribute to the progression of gastric cancer through paracrine effect of soluble factors. Here, we further explore the effect of oestrogen on BMMSCs-mediated human gastric cancer invasive motility. We founded that HBMMSCs notably secrete interleukin-8 (IL-8) protein. Administration of IL-8 specific neutralizing antibody significantly inhibits HBMMSCs-mediated gastric cancer motility. Treatment of recombinant IL-8 soluble protein confirmed the role of IL-8 in mediating HBMMSCs-up-regulated cell motility. IL-8 up-regulates motility activity through Src signalling pathway in human gastric cancer. We further observed that 17ß -estradiol inhibit HBMMSCS-induced cell motility via suppressing activation of IL8-Src signalling in human gastric cancer cells. 17ß-estradiol inhibits IL8-up-regulated Src downstream target proteins including p-Cas, p-paxillin, p-ERK1/2, p-JNK1/2, MMP9, tPA and uPA. These results suggest that 17ß-estradiol significantly inhibits HBMMSCS-induced invasive motility through suppressing IL8-Src signalling axis in human gastric cancer cells.

Acid suppressive agents and risk of Mycobacterium tuberculosis: case-control study.

BACKGROUND: The acid-suppressive agents have been linked with an increased risk of infectious disease. The relationship between these drugs and Mycobacterium Tuberculosis (TB) was not been reported. METHODS: We conducted a case-control study using data from National Health Insurance research database of Taiwan. From 1996 till 2008, and 6541 cases were defined as TB infection/activation (ICD-9 coding plus prescription two of four first-line anti-TB regimen for at least one month). Control subjects who were matched to the TB cases by age and sex were selected with 10:1 ratio. Medical records including acid-suppressive agent prescription and comorbidity, and socioeconomic status were analyzed. RESULTS: TB infection/activation was more frequent to comorbidity with chronic diseases, alcohol abuse, malignancy, immune deficient/suppression status and acid-related disease (peptic ulcer, reflux esophagitis). Among the TB cases, there was higher exposure record to acid-suppressive agents within 3 months before TB index date (OR 2.43(2.06-2.88) and 1.90 (1.68-2.14) for proton pump inhibitor (PPI) and histamine 2 receptor antagonist (H2RA) respectively). After adjusting confounding factors, PPIs prescription 3 months before TB index date had an association of TB infection/activation (adjusted OR 1.63(1.61-1.63)). Similar result was found in H2RA user (adjusted OR 1.51(1.50-1.52)). The association of acid-suppressive agents in TB infection/activation was fade gradually when the drug prescription period extended. CONCLUSIONS: Recent prescription of acid-suppressive agent seems to associate the TB infection/activation. In the society where TB was prevalent, evaluation of pulmonary TB before prescription of PPI or H2RA is warranted.

17ß-estradiol inhibits mesenchymal stem cells-induced human AGS gastric cancer cell mobility via suppression of CCL5- Src/Cas/Paxillin signaling pathway.

Gender differences in terms of mortality among many solid organ malignancies have been proved by epidemiological data. Estrogen has been suspected to cast a protective effect against cancer because of the lower mortality of gastric cancer in females and the benefits of hormone replacement therapy (HRT) in gastric cancer. Hence, it suggests that 17ß-estradiol (E2) may affect the behavior of cancer cells. One of the key features of cancer-related mortality is metastasis. Accumulating evidences suggest that human bone marrow mesenchymal stem cells (HBMMSCs) and its secreted CCL-5 have a role in enhancing the metastatic potential of breast cancer cells. However, it is not clear whether E2 would affect HBMMSCs-induced mobility in gastric cancer cells. In this report, we show that CCL-5 secreted by HBMMSCs enhanced mobility in human AGS gastric cancer cells via activation of Src/Cas/Paxillin signaling pathway. Treatment with specific neutralizing antibody of CCL-5 significantly inhibited HBMMSCs-enhanced mobility in human AGS gastric cancer cells. We further observe that 17ß-estradiol suppressed HBMMSCs-enhanced mobility by down-regulating CCL5-Src/Cas/paxillin signaling pathway in AGS cells. Collectively, these results suggest that 17ß-estradiol treatment significantly inhibits HBMMSCS-induced mobility in human AGS gastric cancer cells.

Comparison of 10 day bismuth quadruple therapy with high-dose metronidazole or levofloxacin for second-line Helicobacter pylori therapy: a randomized controlled trial.

OBJECTIVES: This prospective study was designed to compare the efficacies of levofloxacin-containing and high-dose metronidazole-containing quadruple therapies after failure of standard triple therapies. METHODS: A total of 150 Helicobacter pylori-infected patients were enrolled in our study and randomly assigned to levofloxacin-containing quadruple therapy (EBTL group) (40 mg of esomeprazole twice daily, 300 mg of bismuth subcitrate four times daily, 500 mg of tetracycline four times daily and 500 mg of levofloxacin once daily for 10 days) (n = 76) or high-dose metronidazole-based quadruple therapy (EBTM group) (40 mg of esomeprazole twice daily, 300 mg of bismuth subcitrate four times daily, 500 mg of tetracycline four times daily and 500 mg of metronidazole four times daily for 10 days) (n = 74). Follow-up endoscopy or urea breath test was done 16 weeks later to assess the treatment response. Patients' responses, CYP2C19 genotypes and antibiotic resistances were also examined. All participants, caregivers and those assessing the outcomes were blinded to group assignment. RESULTS: Intention-to-treat analysis revealed that both groups showed similar eradication rates: EBTL, 78.9% (60/76) (95% CI 69.7%-88.1%) and EBTM, 79.7% (59/74) (95% CI 70.5%-88.7%) [risk ratio (RR) 0.97, 95% CI 0.44-2.14]. Per-protocol results were EBTL = 87.0% (60/69) (95% CI 79.4%-94.9%) and EBTM = 90.8% (59/65) (95% CI 83.8%-97.8%) (RR 0.68, 95% CI 0.23-2.0). We did not find significant differences in compliance (RR 0.5, 95% CI 0.54-2.3) and adverse events (RR 1.11, 95% CI 0.54-2.3) between the two groups. Logistic regression analysis showed that only compliance was an important predictor for eradication failure. CYP2C19 polymorphism did not influence the eradicating effect. CONCLUSIONS: The 10 day bismuth quadruple therapies with high-dose metronidazole or levofloxacin were effective even in areas with high resistance. These two therapies were equally safe and tolerated. Besides this, the metronidazole-containing therapy was cheaper. So it is persuasive that high-dose metronidazole-containing quadruple therapy could be a good choice for second-line H. pylori eradication in areas with high resistance.

Helicobacter pylori infection associated with high HbA1c and type 2 diabetes.

BACKGROUND: Although the association between chronic Helicobacter pylori infection and type 2 diabetes has been suggested, findings have been inconsistent. This study evaluated the association between chronic H. pylori infection and glucose regulation. MATERIALS AND METHODS: We evaluated H. pylori infection status of participants recruited from the gastroenterology clinic at our hospital. At baseline, we performed blood tests including fasting plasma glucose, insulin, glycated haemoglobin A1c (HbA1c) and other biochemical measurements. Insulin resistance and beta-cell function were assessed by homoeostasis model assessment (HOMA-IR and HOMA-B, respectively). RESULTS: A total of 2070 participants were recruited. Those who had H. pylori infections had higher serum HbA1c levels and lower HOMA-B than those who did not (5.78% vs. 5.69%, P = 0.01 and 53.85 + 38.43 vs. 60.64 + 43.40, P = 0.009, respectively). They also had a significantly higher prevalence of type 2 diabetes (8.97% vs. 5.57%, P= 0.02). Chronic H. pylori infection was significantly associated with high levels of HbA1c and type 2 diabetes in participants above 65 years old (P = 0.001) and decreased insulin secretion and sensitivity in those under 45 years (P = 0.05). CONCLUSIONS: Long-term H. pylori infection is significantly associated with high levels of HbA1c and decreased insulin secretion in this Chinese population. Proper screening for H. pylori infection combined with regular monitoring of blood glucose and HbA1c levels might be effective for the early detection of glucose dysregulation and prevention of type 2 diabetes.

Sequential and concomitant therapy with four drugs is equally effective for eradication of H pylori infection.

BACKGROUND & AIMS: Sequential therapy with a proton pump inhibitor (PPI) and amoxicillin followed by a PPI, clarithromycin, and an imidazole agent reportedly have a better rate of curing Helicobacter pylori infection than PPI, amoxicillin, and clarithromycin triple therapy. The concomitant administration of these 4 drugs (concomitant therapy) is also an effective treatment strategy. We compared the efficacies of sequential and concomitant therapy and analyzed the effects of antibiotic resistance in patients with H pylori infection. METHODS: In a randomized trial of 232 H pylori-infected patients from 3 hospitals in Kaohsiung, Taiwan, patients were given 10 days of sequential (n = 115) or concomitant (n = 117) therapy. H pylori status was confirmed by endoscopy or urea breath test. RESULTS: Intention-to-treat analysis demonstrated similar eradication rates for sequential (92.3%; 95% confidence interval [CI], 87.5%-97.1%) and concomitant therapy (93.0%; 95% CI, 88.3%-97.7%)(P = .83). Per-protocol eradication results were similar for sequential (93.1%; 95% CI, 90.7%-95.5%) and concomitant therapy (93.0%; 95% CI, 88.3%-97.7%) (P = .99). Univariate analysis showed that compliance and resistance to clarithromycin were independent determinants of eradication. Dual resistance did not influence the level of eradication in the concomitant group, but significantly affected that of the sequential therapy group. Clarithromycin resistance was less frequent than expected. CONCLUSIONS: Sequential or concomitant therapy with a PPI, amoxicillin, clarithromycin, and an imidazole agent are equally effective and safe for eradication of H pylori infection. Resistance to clarithromycin, compliance, and adverse events reduced the level of eradication. Concomitant therapy may be more suitable for patients with dual resistance to antibiotics.

Identification of gastric cancer stem cells using the cell surface marker CD44.

Cancer stem cells (CSCs) have been defined as a unique subpopulation in tumors that possess the ability to initiate tumor growth and sustain tumor self-renewal. Although the evidence has been provided to support the existence of CSCs in various solid tumors, the identity of gastric CSCs has not been reported. In this study, we have identified gastric cancer-initiating cells from a panel of human gastric cancer cell lines using cell surface marker CD44. Among six gastric cancer cell lines, three lines MKN-45, MKN-74, and NCI-N87 had a sizeable subpopulation of CD44(+) cells, and these cells showed spheroid colony formation in serum-free media in vitro as well as tumorigenic ability when injected into stomach and skin of severe combined immunodeficient (SCID) mice in vivo. The CD44(+) gastric cancer cells showed the stem cell properties of self-renewal and the ability to form differentiated progeny and gave rise to CD44(-) cells. CD44 knockdown by short hairpin RNA resulted in much reduced spheroid colony formation and smaller tumor production in SCID mice, and the CD44(-) populations had significantly reduced tumorigenic ability in vitro and in vivo. Other potential CSC markers, such as CD24, CD133, CD166, stage-specific embryonic antigen-1 (SSEA-1), and SSEA-4, or sorting for side population did not show any correlation with tumorigenicity in vitro or in vivo. The CD44(+) gastric cancer cells showed increased resistance for chemotherapy- or radiation-induced cell death. These results support the existence of gastric CSCs and may provide novel approaches to the diagnosis and treatment of gastric cancer.

Fibroblastic colony-forming unit bone marrow cells delay progression to gastric dysplasia in a helicobacter model of gastric tumorigenesis.

Bone marrow mesenchymal stem cells (MSCs) have been shown to have immune modulatory effects. Despite efforts to identify these cells in vivo, to date, MSCs have been defined mainly by their in vitro cell characteristics. Here, we show that Lin(-)CD44(hi)Sca1(-)cKit+CD34(-) cells make up approximately 0.5%-1% of murine whole bone marrow cells and yield nearly an equal amount of fibroblastic colony-forming units (CFU-F) as whole bone marrow. After transplantation into lethally irradiated recipients, Lin(-)CD44(hi)Sca1(-)cKit+CD34(-) cells engrafted in the bone marrow long-term and demonstrated characteristics of MSCs, including capacity to differentiate into osteoblasts and adipocytes. To examine whether Lin(-)CD44(hi)Sca1(-)cKit+CD34(-) cells have immune modulatory effects, in vitro coculture with activated CD4+ T-cells resulted in decreased Th17 cell differentiation by Lin(-)CD44(hi)Sca1(-)cKit+CD34(-) cells. Furthermore, serial infusions with Lin(-)CD44(hi)Sca1(-)cKit+CD34(-) cells reduced the progression to low-grade gastric dysplasia in mice infected with chronic Helicobacter felis (p = .038). This correlated with reduced gastric interleukin (IL)-17F, IL-22, and ROR-gammat gene expression in responding mice (p < .05). These data suggest that bone marrow derived Lin(-)CD44(hi)Sca1(-)cKit+CD34(-) cells have characteristics of MSCs and reduce progression of early gastric tumorigenesis induced by chronic H. felis infection. The prevention of dysplastic changes may occur through inhibition of Th17-dependent pathways.

Rabeprazole can overcome the impact of CYP2C19 polymorphism on quadruple therapy.

OBJECTIVES: The prospective study was designed to clarify the impact of CYP2C19 on quadruple therapies and survey the efficacies of rabeprazole-based quadruple therapy for Helicobacter pylori infection after failure of standard triple therapies. PATIENTS AND METHODS: From January 2007 to March 2009, 1055 H. pylori-infected patients received standard triple regimens (proton-pump inhibitor (PPI), clarithromycin, and amoxicillin). Helicobacter pylori eradication was achieved in 865 (81.9%) subjects. One hundred ninety eradication-failure patients were enrolled and randomly assigned to receive a 7-day eradication therapy. Ninety-six patients were treated with esomeprazole-based quadruple rescue therapies (EB), while 94 patients were treated with rabeprazole-based quadruple rescue therapies (RB). Follow-up endoscopy was done 16 weeks later to assess the treatment response. Patients' responses, CYP2C19 genotypes, and antibiotics resistances were also examined. RESULTS: Intention-to-treat analysis revealed that RB had better eradication rates than EB (EB: 72.9%; 95% CI: 64.9-80.9% and RB: 78.7%; 95% CI 72.5-84.9%) (p value = .543). Per-protocol results were EB = 75.3%; 95% CI: 70.3-80.3% and RB = 85.1%; 95% CI: 80.6-89.6% (p value = .0401). Both regimens had similar compliance (p value = 0.155) and adverse events (p value = 0.219). We also surveyed those patients without resistance of any antibiotics. RB still showed better outcome than EB. Our data showed that esomeprazole-based regimen and CYP2C19 Hom EM genotype were important predictors for eradication failure. CONCLUSIONS: In quadruple therapy, rabeprazole-based regimens had better efficacy than esomeprazole-based regimens. CYP2C19 polymorphism also played an important role in quadruple therapy. It seems advisable to change PPI to rabeprazole in second-line quadruple therapy.

Identification of a bone marrow-derived mesenchymal progenitor cell subset that can contribute to the gastric epithelium.

Recent studies with Helicobacter-infected mice have shown that bone marrow-derived cells can repopulate the gastric epithelium and progress to cancer. However, it has not been established which cellular subset can potentially contribute to the epithelium. The aim of this study was to investigate the ability of bone marrow-derived mesenchymal stem cells (MSCs) that express cytokeratin 19 (K19) to contribute to the gastric epithelium. MSCs cultures were established from whole bone marrow and expression of K19 was detected in a minority (1 of 13) of clones by real-time PCR and immunostaining. Transfection of a K19-green fluorescent protein (GFP) vector and isolation of GFP-expressing colonies generated high K19-expressing MSC clones (K19GFPMSC). Incubation of MSCs with gastric tissue extract markedly induced mRNA expression of gastric phenotypic markers and was observed to a greater extent in K19GFPMSCs compared with parental MSCs and mock transfectants. Both K19GFPMSCs and GFP-labeled control MSCs gave rise to gastric epithelial cells after injection into the murine stomach. In addition, after blastocyst injections, K19GFPMSCs gave rise to GFP-positive gastric epithelial cells in all 13 pups, whereas only 3 of 10 offspring showed GFP-positive gastric epithelial cells after injection of GFP-labeled control MSCs. Although K19 expression could not be detected in murine whole bone marrow, H. felis infection increased K19-expressing MSCs in the circulation. Taken together, our results show that bone marrow-derived MSCs can contribute to the gastric epithelium. The K19-positive MSC fraction that is induced by chronic H. felis infection appears to be the important subset in this process.

Comparison of 10-day levofloxacin bismuth-based quadruple therapy and levofloxacin-based triple therapy for Helicobacter pylori.

OBJECTIVE: This was a prospective study aiming to investigate whether levofloxacin plus bismuth-based quadruple therapy was more effective than levofloxacin-based triple therapy after failed first-line eradication therapies for Helicobacter pylori (H. pylori) infection. METHODS: Sixty-seven patients infected with H. pylori were randomly assigned to two groups; the levofloxacin plus bismuth-based quadruple therapy group (RBAL [n = 33]; rabeprazole 20 mg twice daily, bismuth subcitrate 120 mg four times daily, amoxicillin 1 g twice daily and levofloxacin 500 mg once daily, for 10 days) and the levofloxacin-based triple therapy group (RAL [n = 34]; rabeprazole 20 mg twice daily, amoxicillin 1 g twice daily and levofloxacin 500 mg once daily, for 10 days). Endoscopy was performed 4-8 weeks after H. pylori eradication to assess treatment response. We followed up patient response and compliance and checked their resistance to antibiotics. RESULTS: Intention-to-treat analysis revealed that both groups had similar eradication rates (RBAL vs RAL: 84.8% [95% confidence interval {CI} 72.6-97.1%] vs 67.6% [95% CI 51.9-83.4%], P = 0.0987). No significant differences in compliance or adverse events were found (P = 0.9829 and 0.0720). Epsilometer test showed that most eradication failure cases were levofloxacin-resistant. CONCLUSIONS: Adding bismuth subcitrate to levofloxacin-based triple therapy was not more effective than not doing so, but no further side effects were noted. Both eradication therapies were equally safe and patients had the same tolerance to both regimens. Resistance rate to levofloxacin may be important when choosing second-line therapy.

Diagnosis of Helicobacter pylori infection: Current options and developments.

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Detection of genotypic clarithromycin-resistant Helicobacter pylori by string tests.

AIM: To evaluate the utility of the string test to detect genotypic clarithromycin-resistant Helicobacter pylori (H. pylori) by polymerase chain reaction (PCR)-restriction fragment length polymorphism. METHODS: Patients undergoing endoscopic examinations were enrolled in the present study. String tests were done on the next day of endoscopy. Segments of 23S rRNA were amplified from DNA obtained from string tests. PCR-restriction fragment length polymorphism was accomplished by restriction enzymes BbsI and BsaI recognizing the mutation site A to G at 2143 or at 2142 of 23S rRNA domain V, respectively. RESULTS: One hundred and thirty-four patients with H. pylori infection underwent string tests. To compare phenotypic resistance, 43 isolates were successfully cultured in 79 patients in whom 23S rRNA was successfully amplified. Of five patients with clarithromycin-resistant H. pylori, 23S rRNA of H. pylori isolates from four patients could be digested by BsaI. In 38 susceptible isolates, 23S rRNA of H. pylori isolates from 36 patients could not be digested by either BsaI or BbsI. The sensitivity and specificity of the string test to detect genotypic clarithromycin resistance were 66.7% and 97.3%, respectively. Positive and negative predictive values were 80% and 94.7%, respectively. CONCLUSION: String test with molecular analysis is a less invasive method to detect genotypic resistance before treatment. Further large-scale investigations are necessary to confirm our results.

The effect of Helicobacter pylori eradication on the levels of essential trace elements.

OBJECTIVE: This study was designed to compare the effect of Helicobacter pylori (H. pylori) infection treatment on serum zinc, copper, and selenium levels. PATIENTS AND METHODS: We measured the serum zinc, copper, and selenium levels in H. pylori-positive and H. pylori-negative patients. We also evaluated the serum levels of these trace elements after H. pylori eradication. These serum copper, zinc, and selenium levels were determined by inductively coupled plasma mass spectrometry. RESULTS: Sixty-three H. pylori-positive patients and thirty H. pylori-negative patients were studied. Serum copper, zinc, and selenium levels had no significant difference between H. pylori-positive and H. pylori-negative groups. There were 49 patients with successful H. pylori eradication. The serum selenium levels were lower after successful H. pylori eradication, but not significantly (P = 0.06). There were 14 patients with failed H. pylori eradication. In this failed group, the serum selenium level after H. pylori eradication therapy was significantly lower than that before H. pylori eradication therapy (P < 0.05). The serum zinc and copper levels had no significant difference between before and after H. pylori eradication therapies. CONCLUSION: H pylori eradication regimen appears to influence the serum selenium concentration (IRB number: KMUH-IRB-20120327).

Terlipressin-induced hyponatremic encephalopathy in a noncirrhotic patient.

Terlipressin, an analogue of vasopressin, is frequently used for the management of esophageal varices bleeding and hepatorenal syndrome. Terlipressin therapy in portal hypertensive patients is frequently associated with hyponatremia, but is rarely accompanied with serious neurological manifestations. A 39-year-old female with pancreatic neuroendocrine tumor, liver metastasis, main portal vein thrombosis, and a history of esophageal varices presented to the emergency room because of hematemesis. Terlipressin was given with a loading dose of 2 mg followed by 1 mg every 6 hours. After a total of 6 mg terlipressin injection, she suffered from acute delirium. Pertinent examinations showed there was no gross brain lesion by computed tomography, whereas her serum sodium level dropped from baseline (136 mmol/L) to 116 mmol/L with a serum osmolality of 256 mOsm/kg. At that time, urine sodium and urine osmolality were 142 mmol/L and 488 mOsm/kg, respectively. Under the tentative diagnosis of terlipressin-induced hyponatremic encephalopathy, terlipressin was withheld and hypertonic saline infusion was given. Within 12 hours, her serum sodium level recovered to 130 mmol/L and she gradually regained her cognitive functions. Although symptomatic hyponatremic encephalopathy is a rare complication of terlipressin treatment, close monitoring of serum electrolyte level is warranted in patients receiving terlipressin.

Differentiation of virulence of Helicobacter pylori by matrix-assisted laser desorption/ionization mass spectrometry and multivariate analyses.

BACKGROUND: The ability to determine the virulence of a Helicobacter pylori strain would be helpful for predicting the development of gastrointestinal disease and suggesting medical treatment. METHODS: A protocol based on matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS) was established for the efficient detection of peptides and proteins in extracts of H. pylori cells. Two multivariate statistical methods-principal component analysis (PCA) and hierarchical clustering analysis-were used to analyze the resulting MALDI mass spectra of reference strains and clinical isolated/inoculated strains. RESULTS: Based on differences in their peptide and protein profiles, H. pylori strains having similar virulence genotypes were grouped together on the PCA score plot. Hierarchical cluster analysis revealed high conformity between the protein profiles and the respective virulence genotypes. The inoculated H. pylori strain, which was clustered in the same group with the high-virulence reference strains, also resulted in severe histopathological lesions in gerbils. CONCLUSIONS: MALDI-TOF MS combined with multivariate analyses shows the ability to rapidly differentiate H. pylori strains in terms of their virulence.