Shu-Peng Ho

We investigated the antimicrobial activity and membrane disruption modes of the antimicrobial peptide mastoparan-AF against hemolytic Escherichia coli O157:H7. Based on the physicochemical properties, mastoparan-AF may potentially adopt a 3–11 amphipathic helix-type structure, with five to seven nonpolar or hydrophobic amino acid residues forming the hydrophobic face. E. coli O157:H7 and two diarrheagenic E. coli veterinary clinical isolates, which are highly resistant to multiple antibiotics, are sensitive to mastoparan-AF, with minimum inhibitory and bactericidal concentrations (MIC and MBC) ranging from 16 to 32 μg mL⁻¹ for E. coli O157:H7 and four to eight μg mL⁻¹ for the latter two isolates. Mastoparan-AF treatment, which correlates proportionally with membrane permeabilization of the bacteria, may lead to abnormal dents, large perforations or full opening at apical ends (hollow tubes), vesicle budding, and membrane corrugation and invagination forming irregular pits or pores on E. coli O157:H7 surface. In addition, mRNAs of prepromastoparan-AF and prepromastoparan-B share a 5′-poly(A) leader sequence at the 5′-UTR known for the advantage in cap-independent translation. This is the first report about the 3–11 amphipathic helix structure of mastoparans to facilitate membrane interaction. Mastoparan-AF could potentially be employed to combat multiple antibiotic-resistant hemolytic E. coli O157:H7 and other pathogenic E. coli.

Shewanella haliotisis an emerging human pathogen. Many infectious cases were linked to shellfish ingestion or aquatic exposure. Therefore, it is important to study the phylogeny and distribution ofS. haliotisin shellfish aquaculture. We investigated the distribution ofS. haliotisin cultivated shellfish farming in Taiwan in whichS. haliotiswas found in the shellfish from all sampling sites.S. haliotiswas identified in cultivated shellfish by 16S rRNA gene sequencing, such as abalone (Haliotis diversicolor), clam (Meretrix lusoria), and oyster (Crassostrea gigas). This study highlighted the contamination ofS. haliotisin cultivated shellfish and importance of further study regarding the biodiversity and pathogenesis ofS. haliotis.

Proton pump inhibitors (PPIs) are widely applied for acid related disorders, and possess pleiotropic biological functions. The effect of PPIs on the gastric mucosa, neutrophil and Helicobacter pylori (H. pylori) infiltration and glandular atrophy has not been well investigated, particularly the duration of the effects of PPIs. To investigate the effects of PPIs on neutrophil infiltration, H. pylori infiltration and the gastric mucosa. A total of 76 adult patients with gastrointestinal symptoms who had undergone upper gastrointestinal endoscopy were enrolled in the study. Each patient's history was recorded, including smoking, alcohol consumption and the duration of PPI use prior to gastric biopsy. Endoscopic biopsies of gastric antral mucosa were performed and evaluated by histology. Neutrophil and H. pylori infiltration were graded by H & E staining in accordance with the updated Sydney system. Among the 76 patients, 44 patients had H. pylori infection and 19 patients had taken PPIs for varying durations prior to gastric biopsy. Neutrophil infiltration was significantly inhibited by PPIs (p = 0.005). The duration of PPI use was correlated with inhibition of neutrophil and H. pylori infiltration. A logistical regression analysis demonstrated that PPIs significantly inhibited neutrophil infiltration in the gastric mucosa and were associated with atrophy of the mucosa. PPIs attenuated neutrophil infiltration of gastric mucosa, and may be related to atrophy of the mucosa.

In humans, the presence of antiphospholipid antibodies (aPL) is frequently found in immune thrombocytopenia. The present study investigated whether aPL and any aPL subtypes are associated with canine thrombocytopenia, in particular, immune-mediated thrombocytopenia (immune thrombocytopenia) that usually manifests with severe thrombocytopenia. Sera were collected from 64 outpatient dogs with thrombocytopenia (Group I, platelet count 0 – 80 × 103/uL), and 38 of which having severe thrombocytopenia (platelet count < 30 × 103/uL) were further divided into subgroups based on the presence of positive antiplatelet antibodies (aPLT) (subgroup IA, immune thrombocytopenia, n =20) or the absence of aPLT (subgroup IB, severe thrombocytopenia negative for aPLT, n =18). In addition, sera of 30 outpatient dogs without thrombocytopenia (Group II), and 80 healthy dogs (Group III) were analyzed for comparison. Indirect ELISAs were performed to compare serum levels of aPL subtypes, including anticardiolipin antibodies (aCL), antiphosphatidylserine antibodies (aPS), antiphosphatidylcholine (aPC), and anti-β2 glycoprotein I antibodies (aβ2GPI), and antiphosphatidylinositol antibodies (aPI), among different groups or subgroups of dogs. Among outpatient dogs, aCL, being highly prevalent in outpatient dogs with thrombocytopenia (63/64, 98 %), is an important risk factor for thrombocytopenia (with a high relative risk of 8.3), immune thrombocytopenia (relative risk 5.3), or severe thrombocytopenia negative for aPLT (relative risk ∞, odds ratio 19). In addition, aPS is a risk factor for immune thrombocytopenia or severe thrombocytopenia negative for aPLT (moderate relative risks around 2), whereas aPC and aβ2GPI are risk factors for immune thrombocytopenia (relative risks around 2). Of all the aPL subtypes tested here, aCL is highly associated with canine thrombocytopenia, including immune thrombocytopenia, severe thrombocytopenia negative for aPLT, and less severe thrombocytopenia. Furthermore, aPS is moderately associated with both canine immune thrombocytopenia and severe thrombocytopenia negative for aPLT, whereas aβ2GPI, and aPC are moderately relevant to canine immune thrombocytopenia. In contrast, aPI is not significantly associated with canine immune thrombocytopenia.

Omeprazole (OMP), a proton pump inhibitor, is a highly effective drug for the management of acid-related disorders. Infections resulting from cytotoxin antigen A (CagA) positive Helicobacter pylori strains have been associated with higher grades of gastric mucosal inflammation. Nuclear factor (NF)-κB activation has been reported to participate in H. pylori-induced gastritis in humans. The complex interaction of OMP on the H. pylori and NF-κB related molecular mechanisms within the gastric mucosa remains unclear. In the present study, we investigated OMP, specifically its effects on NF-κB activation, and COX-2, IL-6, and IL-8 production in gastric cells (Kato-III cells) treated with CagA positive (CagA(+)) and negative (CagA(-)) H. pylori strains. Kato-III cells were stimulated with H. pylori water extracts (HPE) containing ATCC 43504 (CagA(+)) and ATCC 51932 (CagA(-)) strains. NF-κB activation, inhibitory IκB expression and phosphorylation, and cyclooxygenase (COX)-2, interleukin (IL)-6, and IL-8 expression were assessed in the absence and presence of OMP. Both CagA(+) and CagA(-) HPE induced NF-κB activation, whereas OMP suppressed NF-κB activation in the CagA(-) strain. HPE demonstrated a similar effect on IκB protein expression in the absence and presence of OMP. OMP alone decreased IκB phosphorylation without promoting NF-κB and IκB expression. Additionally, both CagA(+) and CagA(-) HPE induced COX-2 expression, but no significant effect on IL-6 and IL-8. However, OMP downregulated the transcription of COX-2, IL-6, and IL-8 in CagA(-) HPE treated cells. Using the Kato-III cells model, H. pylori induces NF-κB activation in a CagA-independent manner. Both CagA(+) HPE and CagA(-) HPE induced COX-2 gene expression, but not for IL-6 and IL-8 expression. However, OMP suppressed NF-κB activation via a downregulation of IκB phosphorylation in CagA(-) HPE treated condition. OMP also suppressed CagA(-)H. pylori induced-transcription of proinflammatory COX-2, IL-6, and IL-8. OMP may provide different effects on CagA(+) and CagA(-)H. pylori infection conditions.

Endoscopic argon plasma coagulation (APC) and hemoclip were used for the treatment of bleeding peptic ulcers. There are wide ranges of hemostatic doses (power and flow) of APC used in previous studies. The aim of our study was to assess the efficacy and safety of "intermediate dose" APC compared to hemoclips for hemostasis from bleeding peptic ulcer. The present study was designed as a retrospective study using historical controls. One hundred and ninety-four consecutive upper GI bleeding patients with bleeding visible vessel lesions were treated with either APC or hemoclips. There are 110 patients received APC treatment and 84 patients received hemoclip hemostasis. The main outcome measurements were one week rebleeding rate, one month rebleeding rate, surgery, morality, amount of blood transfusion and durations of hospital stay. There were no significant differences between the two groups in 1 week rebleeding rate (1.8% vs. 2.4%, p = 1.0), 1 month rebleeding rate (0% vs. 1.2%, p = 0.433), mortality, surgery and amount of blood transfusion (2.67 +/- 3.27 vs. 3.04 +/- 2.75 units, p = 0.322). However, the hospital stay was longer in hemoclip group (5.38 +/- 6.76 vs. 8.49 +/- 11.19 days p = 0.011). APC and hemoclip are with different hemostatic mechanisms, but the hemostatic outcomes were not significantly different between the two groups. APC is an effective, safe, and easily applicable endoscopic hemostatic modality as hemoclip for patients with non-variceal bleeding.

Infection of gastric epithelial cells by Helicobacter pylori stimulates the activation of nuclear factor-κB (NF-κB) and the upregulation of interleukin-8 (IL-8) expression. Activation of NF-κB can occur through classical (p50/p65) and alternative (p52/RelB) pathways. The role of the bacterial cag pathogenicity island (PAI) in these events is controversial. This study aimed to evaluate the hypothesis that the CagA protein is required for H. pylori-induced activation of NF-κB and upregulation of IL-8 expression, and for clarithromycin (CAM) to exert its molecular effects. Cultured KATO-III human gastric cancer cells were treated with extracts of H. pylori strains ATCC43504 (cag PAI⁺) and ATCC51932 (cag PAI⁻) for 24 h. NF-κB and phospho-IκB protein expression was then evaluated using western blotting. IL-8 mRNA expression was evaluated using the reverse transcription polymerase chain reaction. Following the separation of the proteins using two-dimensional gel electrophoresis, proteomes of the two bacterial extracts were compared using nanoflow liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) analysis. Although the protein profiles of the two extracts differed, both extracts induced IκBα phosphorylation, upregulation of IL-8 expression, and NF-κB activation through classical and alternative pathways. In cells treated with either of the bacterial extracts, CAM inhibited H. pylori-induced activation of NF-κB and upregulation of IL-8 expression. These results suggested that CagA is not required for H. pylori-induced activation of NF-κB and upregulation of IL-8 expression in gastric epithelial cells. H. pylori-induced NF-κB signaling can occur through classical and alternative activation pathways, and that CAM inhibits these two pathways.